Process technology for recovering brominated styrenic polymers from reaction mixtures in which they are formed and/or converting such mixtures into pellets or into granules or pastilles

196429/3

PROCESS TECHNOLOGY FOR RECOVERING BROMINATED STYRENIC

POLYMERS FROM REACTION MIXTURES IN WHICH THEY ARE

FORMED AND/OR CONVERTING SUCH MIXTURES INTO

PELLETS OR INTO GRANULES OR PASTILLES

BACKGROUND

[0001] U.S. Pat. Nos. 5,677,390, 5,686,538, 5,767,203, 5,852,131, 5,852,132, 5,916,978,6,113,381,6,207,765,6,232,393,6,232,408,6,235,831,6,235,844,6,326,439,6,521,714, andWO 2005/118245 describe very desirable process technology for producing brominatedstyrenic polymers such as brominated polystyrene having the best known properties of anypreviously-known brominated styrenic polymer. In this connection, the terms "brominatedstyrenic polymer” and "brominated polystyrene" as used in the specification and in the claimshereof refer to a brominated polymer produced by bromination of a pre-existing styrenicpolymer such as polystyrene or a copolymer of styrene and at least one other vinyl aromaticmonomer, as distinguished from an oligomer or polymer produced by oligomerization orpolymerization of one or more brominated styrenic monomers, the properties of the latteroligomers or polymers typically being considerably different from brominated polystyrene in anumber of respects. Also as used herein, including the claims, the term "anionic styrenicpolymer" or "anionic polystyrene", terms commonly used by persons skilled in the art, denotesthat the polymer referred to has been produced by use of an anionic polymerization initiator,such as a lithium alkyl. The terms "brominated styrenic polymer" and "brominatedpolystyrene" include and are generic to the terms "brominated anionic styrenic polymer" or"brominated anionic polystyrene". These generic terms also include, for example, brominatedstyrenic polymers produced by bromination of styrenic polymers or polystyrene made by freeradical polymerization. US Pat. No. 3,156,009 describes a devolatilizing extruder, EP 1 510 530 describes a method of separating a polymer from a solvent, US Pat. No.3,072,626 describes a polymer recovery process.

[0002] As indicated in the above patents, the common method for recovering tlie brominatedstyrenic polymer from the liquid phase of the bromination reaction mixture involvesdeactivating the catalyst with an aqueous quenching medium, separating the brominatedpolymer-containing organic phase from the aqueous phase, stripping the organic phase of itssolvent usually by feeding the organic phase into boiling water whereby the brominatedpolymer is precipitated, recovering the precipitated brominated polymer by a liquid-solids 1 196429/1 separation technique such as filtration or centrifugation, and drying the resultant finely-dividedbrominated styrenic polymer. It would be highly advantageous if a way could be found forrecovering the brominated styrenic polymer in a more efficient and less costly manner.[0003] When blending a brominated styrenic polymer with a substrate thermoplastic polymer 5 to be flame retarded, it is desirable that the brominated styrenic polymer be in the form ofpellets, granules, or pastilles. Unfortunately, a characteristic of brominated anionic 1a WO 2008/011477 PCT/US2007/073805 styrenic polymers such as brominated anionic polystyrene, and to a lesser extent, brominatedstyrenic polymer made by free-radical polymerization as well, is a propensity to formsubstantial amounts of small particles and powders when attempts are made to pelletize theproduct. It appears that the pellets, unless bound together by an extraneous binding agent orthe like, tend during formation, handling, and/or packaging to break apart and to revert tosmall particles and finely-divided powder, typically referred to as "fines”. Because of thischaracteristic, various conventional pelletizing or compacting procedures are unsuitable forproducing brominated anionic styrenic polymers essentially free of fines and that duringshipment and handling remain essentially free of fines. As can be readily appreciated, theexistence or formation of fines in a product of this type is not only detrimental to theappearance of the pelletized product but in addition is undesired by the consumer.

[0004] In order to effectively use brominated styrenic polymers, especially brominatedanionic styrenic polymers, as flame retardants in certain thermoplastic polymers, the use ofbinding agents or other extraneous materials to maintain the integrity of the flame retardantin pelletized form, is also deemed undesirable by some consumers. Thus, it is desirable tobe able to produce unadulterated pelletized brominated styrenic polymers, especiallybrominated anionic styrenic polymers, that do not form undesirable amounts of fines duringtheir preparation, packaging, shipment, and handling.

[0005] In the production of pelletized brominated styrenic polymers, especially brominatedanionic styrenic polymers, it is important to improve the efficiency of the operation and tominimize operating costs. Recovery and recycle of fines avoids waste of product andminimizes waste disposal considerations. However the greater the amount of fines produced,recovered and recycled, the lower the production rate of pellets per quantity of polymer beingsubjected to pelletization. It would be highly advantageous, therefore, if a way could befound of preparing brominated styrenic polymers, especially unadulterated brominatedanionic styrenic polymers, in pelletized form in a highly cost-efficient manner while avoidingformation of excessive amounts of fines, so that the production rate of high quality pellets isnot materially impaired. In the case of brominated anionic styrenic polymers, it would beespecially desirable if a way could be found of producing granules or pastilles of thepolymers. This would enable the achievement of a number of important advantages in theprocess, including the overall process, the handling and storage of the product, and in thetransportation of the product to, and the use of the product by, the end user,

SUMMARY OF THE INVENTION

[0006] Pursuant to one group of embodiments of this invention brominated styrenic polymers, and especially brominated anionic styrenic polymers, can be recovered much more readily and efficiently, and at lower cost, from solution in a solvent, and especially from 2 WO 2008/011477 FCT/US2007/073805 solution in the solvent in which they were formed, as compared to the common method for recovery referred to above.

[0007] Pursuant to another group of embodiments of this invention brominated styrenicpolymers, especially brominated anionic styrenic polymers, can now be produced andpackaged in unadulterated pelletized form essentially free of tines. As used herein, includingthe claims, the terms ’’pellets", "pelletized", "pelletizing", etc., refers to a quantity of particleswhich, if screened using conventional screening practices, are in the size range of that canpass through a screen of about 4 standard U.S. mesh size and which are retained on a screenof about 40 standard U.S. mesh size. The particles in such size range can be of any shape andthus may also be referred to as granules, and thus as used herein including the claims theterms "pellets" "pelletized", "pelletizing", etc. include respectively "granules", "granular","granulating", etc. Due to electrostatic charges, incomplete screening, or the like, some smallamount (e.g., less than about 5 wt% based on the total weight of the pellets in such size range)of finer-sized particles may remain in the product. By the term "unadulterated" as used hereinincluding the claims is meant that no extraneous ingredients such as binders (e.g., waxes orother polymeric or oligomeric substances), inorganic salts, or the like are added to thebrominated styrenic polymer prior to or during the preparation the pellets. Instead, thebrominated styrenic polymer contains only residual impurities that remain in the brominatedpolymer after its preparation.

[0008] Moreover, preferred embodiments of this invention make possible on an economicalbasis the benefits of avoiding formation of undesirable amounts of fines, since only relativelysmall amounts of fines are produced in the operation and the unadulterated pellets formedhave good hardness and crush strength. In fact, in preferred processes of this invention smallamounts of dry fines that may exist in the product being formed can be recovered andrecycled in the operation without much expense or difficulty.

[0009] Other particularly preferred embodiments of this invention enable the production ofbrominated anionic styrenic polymers in the form of granules or pastilles which haverelatively smooth surfaces and which thus are more readily handled, stored, shipped, and usedwithout formation of undesirable amounts of fines, [0010] In each of the embodiments of this invention a "polymer melt", "polymer flow","melt", or "flow" is formed from a brominated styrenic polymer, preferably a brominatedanionic styrenic polymer, in a devolatilization extruder, As used herein including the claims,the terms "polymer melt", "polymer flow", "melt", or "flow" refer to the fact that thebrominated styrenic polymer within the devolatilization extruder becomes a melted massand/or a sufficiently softened mass that will thenceforth proceed (i.e., flow) through theremainder of the devolatilization extruder (including any extension that may be added thereto)and a die disposed at the discharge end of the machine under the thrust provided within the 3 WO 2008/011477 PCT/US2007/073805 machine by the screw(s) thereof. It matters not whether, strictly speaking, a true melt of brominated styrenic polymer has been formed or whether the brominated styrenic polymer has merely been softened to such an extent that it will flow as just indicated.

[0011J Accordingly, among one group of embodiments of this invention there are providedprocesses for recovering brominated styrenic polymer, typically having a bromine content ofat least about 50 wt%, from solution in a vaporizable solvent, preferably a vaporizablehalogenated solvent. These processes comprise converting in a devolatilization extruder anadmixture of extrudable viscosity comprised of brominated styrenic polymer and avaporizable organic solvent into a brominated styrenic polymer melt or flow and a separatevapor phase comprised predominately of vaporizable solvent, recovering said melt or flowof brominated styrenic polymer while in the form of a melt or flow from the devolatilizationextruder, and allowing or causing said melt or flow to solidify, in preferred embodiments ofthis group, the process preferably further comprises subdividing the solidified melt into apowder, granular or pelletized form. Alternatively or in addition, the process furthercomprises recovering and allowing or causing the vapor phase to liquefy as vaporizablesolvent. Preferably, such liquefied solvent is recycled as vaporizable solvent used in formingadditional solution of brominated styrenic polymer. In particularly preferred embodimentsof this group of embodiments an admixture of brominated styrenic polymer and vaporizableorganic solvent of less than extrudable viscosity is converted into an admixture of extrudableviscosity which is subsequently processed in a devolatilization extruder as described earlierin this paragraph. This conversion from less than extrudable viscosity to extrudable viscosityis typically accomplished by removing, e.g., by distillation or flash distillation, a sufficientamount of vaporizable organic solvent, preferably a vaporizable halogenated organic solvent,from the admixture of less than extrudable viscosity to form an admixture of extrudableviscosity. In especially preferred embodiments of this group of embodiments, the admixtureof less than extrudable viscosity is formed by brominating styrenic polymer in vaporizableorganic solvent, preferably a halogenated organic solvent, and obtaining from the brominationprocess an admixture of less than extrudable viscosity comprised of brominated styrenicpolymer, typically having a bromine content of at least about 50 wt%, and vaporizablesolvent, preferably a halogenated organic solvent. Often such admixtures of less thanextrudable viscosity are solutions of brominated styrenic polymer having a bromine contentof at least 50 wt%, preferably at least about 60 wt%, and more preferably at least about 67wt%, in a vaporizable organic solvent, preferably a vaporizable halogenated organic solvent.In some embodiments of this group of embodiments, particular ways of conducting thebromination reaction and/or ensuing work up operations leading to the formation of anadmixture of less than extrudable viscosity are utilized as preliminary operations. In someof the embodiments of this group of embodiments, before processing an admixture of 4 WO 2008/011477 PCT/US2007/073805 brominated styrenic polymer and vaporizable organic solvent of extrudable viscosity in adevolatilzation extruder as described earlier in this paragraph this admixture is subjected toa coalescing filtration to remove entrained water and dissolved salts that may be present insuch admixture. Another preferred operation that may be performed in the variousembodiments of this group of embodiments is preheating of the admixture of extrudableviscosity if it is in the form of solids at a temperature below about 175 °C prior to being atextrudable viscosity for processing within the devolatilization extruder as described earlierin this paragraph. This preheating can be accomplished either in a preheater section alreadyassociated with the devolatilization extruder as manufactured or by use of a separate preheaterwhich discharges its suitably preheated contents into the inlet portion of the devolatilizationextruder. The preheating should raise the temperature of the admixture so that it can be fedin at least a softened movable state, a partially liquefied state, a liquefied state, or at anextrudable viscosity into the devolatilization extruder. In addition, temperature control withinthe extruder can be effected by screw design, screw speed, and/or barrel temperatureregulation. Also, the devolatilization extruder may be provided with cooling capabilities toavoid localized overheating.

[0012 J Among another group of embodiments of this invention there are provided processesfor preparing pelletized brominated styrenic polymer, typically having a bromine content ofat least about 50 wt%, from the extrudate from a devolatilization extruder functioning asdescribed in the immediately preceding paragraph. The various embodiments of this groupof embodiments utilize any of the embodiments described in the immediately precedingparagraph involving the processing of an admixture of extrudable viscosity in adevolatilization extruder, including each of the various embodiments described in theimmediately preceding paragraph that involve one or more operations conducted prior to suchprocessing in the devolatilization extruder. Thus instead of recovering a melt or flow ofbrominated styrenic polymer while in the form of a melt or flow from the devolatilizationextruder, and allowing or causing said melt or flow to solidify, in this group of embodimentsthe melt or flow from the devolatilization extruder is passed through a die to produce one, ormore than one, emerging strand of brominated styrenic polymer melt or flow, the strand(s)is/are allowed or caused to solidify, and the strand(s) is/are subdivided into solidified pelletsof brominated styrenic polymer. Preferred ways of processing such strand(s) form additionalembodiments of this group of embodiments of this invention.

[0013] Still another group of embodiments of this invention involve a process of producing granules or pastilles of unadulterated brominated anionic styrenic polymer, which process comprises: > converting in a devolatilization extruder, an admixture of brominated styrenic polymer and a vaporizable organic solvent into a melt or flow of brominated anionic 5 WO 2008/011477 PCT/US2007/073805 styrenic polymer and a separate vapor phase of said solvent; and> forming from said melt or flow a downwardly oriented plug flow from at least one orifice in a manifold or nozzle that is in proximity to a cooled traveling planarmember, said planar member being impervious to cooling liquid and having an upperand lower surface, whereby there is a gap between the lower portion of the orifice andsaid upper surface, so that at least a portion of a plug of molten unadulteratedbrominated anionic styrenic polymer either (i) bridges said gap and forms a separateindividual granule or pastille on the upper surface of said planar member, or (ii) freelydrops from the lower portion of the orifice and falls upon the upper surface of saidplanar member and forms an individual granule or pastille on the upper surface of saidplanar member, said traveling member being cooled by a mist or spray of coolingliquid contacting the lower surface of said planar member.

[0014] The above and other embodiments, features and/or advantages of this invention willbecome still further apparent from the ensuing description, accompanying drawings, andappended claims.

[0015] Except for the embodiments involving preparation of granules or pastilles frombrominated anionic styrenic polymer such as brominated anionic polystyrene, in all of theother embodiments of this invention such as those referred to above and those describedhereinafter, preferred brominated styrenic polymers are those formed by bromination ofstyrenic polymers formed by free radical polymerization ("free-radical styrenic polymers").Especially preferred are brominated styrenic polymers formed by bromination of styrenicpolymers prepared by anionic polymerization ("anionic styrenic polymers"). Of the free-radical styrenic polymers, rubber-free polystyrene formed by free radical polymerization ispreferred ("free-radical polystyrene"). Of the anionic styrenic polymers, rubber-freepolystyrene formed by anionic polymerization is preferred ("anionic polystyrene"). Whileother types of brominated styrenic polymers such as brominated styrenic polymer formed bybromination of styrenic polymer formed by cationic polymerization can be used they are notpreferred.

[0016] As used herein, including the claims, the term “extrudable viscosity” means that theadmixture has a viscosity in the range of about 5000 to about 5,000,000 centipoise at 100reciprocal seconds while at a temperature in the range of about 175 ° C to about 300 ° C. Suchadmixtures can be caused to flow (e.g. by means of a suitable pump) into and through adevolatilization extruder and be worked within the extruder to release vaporizable organicsolvent in the vapor state when the admixture is at least at one or more temperatures in and/orabove the foregoing range. By the term “admixture” is meant a mixture of specifiedcomponents, which mixture can be in the form of solids, or preferably in the form of at leastone liquid phase and which, whether in the form of one liquid phase or more than one liquid 6 WO 2008/011477 PCT/US2007/073805 phase, can have one or more solid phases suspended therein. Xt should be noted that the term"extrudable viscosity" refers to a viscosity that the admixture will achieve when it is beingprocessed within the devolatilization extruder. Prior to this processing the admixture ofextrudable viscosity need not be, and usually is not, at extrudable viscosity.

[0017] In all process embodiments of this invention the admixture of extrudable viscositypreferably is not exclusively in the form of solids, but rather is in the form of a viscousflowable mass having a liquid phase which can have solids suspended or dispersed therein.[0018] All references in this specification or in the ensuing claims to “pressure” inconnection with a devolatilization extruder or its use relate to the reduced pressures (vacuum)imposed upon the melt or flow, and do not relate to the force exerted upon the melt or flowby the screw(s) of the devolatilization extruder. To determine in any embodiment of thisinvention the amount of organic solvent in the polymer, it is desirable to use NMR analysis.The result should show that the melt or flow of brominated styrenic polymer that has exitedfrom the outlet portion of the devolatilization extruder contains an average of less than about10,000 ppm (wt/wt), and preferably less than about 5000 ppm (wt/wt), and still morepreferably less than about 1000 ppm (wt/wt) of the organic solvent in steady state operation. BRIEF DESCRIPTION OF THE DRAWINGS[0019] Fig 1 is a block diagram illustrating an overall process for the preparation andisolation of the pelletized unadulterated brominated styrenic polymers of this invention.[0020] Fig. 2 is a schematic top view of a mechanical system suitable for producingpursuant to the processes of this invention, pelletized unadulterated brominated styrenicpolymers and preferably, pelletized unadulterated brominated anionic styrenic polymers, ofthis invention.

[0021] Fig. 3 is a schematic side view of the system of Fig. 2.

[0022] Fig. 4 is a block diagram illustrating an overall process of this Invention for thepreparation of granules or pastilles of unadulterated brominated styrenic polymers.

FURTHER DETAILED DESCRIPTION OF THE INVENTION SOME EMBODIMENTS INVOLVING RECOVERING BROMINATED STYRENIC POLYMER[0023] A) A process for recovering brominated styrenic polymer from admixture in avaporizable organic solvent, which process comprises processing an admixture of at leastextrudable viscosity comprised of brominated styrenic polymer typically having a brominecontent of at least about 50 wt%, preferably at least about 60 wt%, and more preferably atleast about 67 wt%, and a vaporizable organic solvent, in a devolatilization extruder to forma melt or flow of such brominated styrenic polymer and a vapor phase comprised ofvaporizable organic solvent, recovering from the devolatilization extruder such melt or flow 7 WO 2008/011477 PCT/US2007/073805 of brominated styrenic polymer while in the form of a melt or flow, and allowing or causingsaid melt or flow to solidify. Preferably, the melt or flow of such brominated styrenicpolymer that has exited from the outlet portion of the devolatilization extruder contains anaverage of less than about 10,000 ppm (wt/wt), more preferably less than about 5000 ppm(wt/wt), and still more preferably less than about 1000 ppm (wt/wt) of the organic solvent insteady-state operation of the devolatilization extruder. Preferably, the vapor phase is alsorecovered.

[00241 B) A process for recovering brominated styrenic polymer from admixture in avaporizable organic solvent, which process comprises > continuously introducing into the inlet portion of an operating devolatilizationextruder, an admixture of extrudable viscosity, said admixture comprising brominatedstyrenic polymer typically having a bromine content of at least about 50 wt%,preferably at least about 60 wt%, and more preferably at least about 67 wt%, and avaporizable organic solvent, said extruder having an inlet portion and a polymer meltor polymer flow outlet portion and at least two sections that can be operated (a) attemperatures that differ from each other, and (b) under pressures that differ from eachother, one of the at least two sections being disposed upstream from the other of theat least two sections, the devolatilization extruder having vapor collecting apparatusadapted to collect volatiles formed in these at least two sections; and > operating said section disposed downstream at higher temperature and lower pressure conditions than the temperature and pressure conditions of said section disposedupstream, so that (a) a flow or melt of said polymer is formed within thedevolatilization extruder and released from the polymer melt or polymer flow outlet,and (b) volatiles composed predominately of the solvent released from the polymerin said at least two sections can be collected by said vapor collecting apparatus, themelt or flow of such brominated styrenic polymer that has exited from the outletportion of the devolatilization extruder containing an average of less than about10,000 ppm (wt/wt), preferably less than about 5000 ppm (wt/wt), and still morepreferably less than about 1000 ppm (wt/wt) of the organic solvent in steady-stateoperation of the devolatilization extruder.

[0025] C) A process for recovering brominated styrenic polymer from admixture witha vaporizable solvent, preferably a vaporizable halogenated solvent, which admixture is anadmixture of less than extrudable viscosity, such as a solution containing in the range of about15 to about 40 wt% of brominated anionic styrenic polymer (preferably brominated anionicpolystyrene) formed by brominating to a bromine content of about 50 wt%, preferably at leastabout 60 wt%, and more preferably at least about 67 wt%, and anionic styrenic polymer,preferably anionic polystyrene, having a GPC weight average molecular weight in the range 8 WO 2008/011477 PCT/US2007/073805 of about 2000 to about 200,000, preferably in the range of about 2000 to about 10,000, and more preferably in the range of about 3000 to about 7000, such process comprising: > concentrating or converting such admixture into an admixture of extrudable viscosityby distillation, preferably by flash distillation; and > utilizing such admixture of extrudable viscosity as the feed in the process as describedin embodiment A) or embodiment B) above.

[0026] In embodiments of this invention involving concentrating or converting a precursoradmixture, e.g,, a solution or suspension, of less than extrudable viscosity by utilizingdistillation or flash distillation to accomplish concentration or conversion to an admixture ofextrudable viscosity, several advantages are achieved. In addition to introducing into adevolatilization extruder a more concentrated admixture or solution for conversion into a meltor polymer flow and thus reducing the amount of solvent to be recovered by operation of thedevolatilization extruder, the initial solution of the brominated styrenic polymer is heated toeffect the distillation or flash distillation. Thus by promptly feeding the distilled or flashdistilled admixture of extrudable viscosity into the devolatilization extruder, such admixtureis in effect preheated, thus reducing the total heat energy required by the devolatilizationextruder to convert the admixture into a melt or polymer flow. Concentration also removeswater with the distilled solvent so that any organic solvent removed in the devolatilizationextruder is anhydrous and suitable for direct recycle to bromination without a separate dryingstep. In addition, the anhydrous feed to the devolatilization extruder is less corrosive becauseof the absence of water in such feed. In embodiments where concentrating the brominatedstyrenic polymer admixture is not required, the same advantages (except for the removal ofwater) can be achieved by preheating the admixture of extrudable viscosity prior to feedingit to the devolatilization extruder.

[0027] Also, unlike the recovery process of U.S. Pat. No. 5,043,421, which requires use inan extruder of at least one non-solvent such as an alkanol or ketone (specifically methanol, 2-propanol, or acetone), the recovery embodiments of this invention do not require use of anysuch non-solvent. In other words, the recovery processes of this invention preferably do notfeed into the devolatilization extruder any such non-solvent, and preferably the recoveredextrudate is devoid of detectable amounts of such alcoholic or ketonic non-solvents.

SOME EMBODIMENTS INVOLVING FORMING PELLETIZED BROMINATED STYRENICPOLYMER

[0028] 1) A process for producing pelletized brominated styrenic polymer from admixture in a vaporizable organic solvent, which process comprises processing an admixture of at least extrudable viscosity comprised of brominated styrenic polymer typically having a bromine content of at least about 50 wt%, preferably at least about 60 wt%, and more 9 WO 2008/011477 PCT/US2007/073805 preferably at least about 67 wt%, and a vaporizable organic solvent, in a devolatilization extruder to form a melt or flow of such brominated styrenic polymer and a vapor phase comprised of vaporizable organic solvent, recovering from the devolatilization extruder such melt or flow of brominated styrenic polymer while in the form of a melt or flow, and converting such melt or flow into solid pellets of brominated styrenic polymer.

[0029] 2) A process for producing pelletized brominated styrenic polymer from solutionin a vaporizable solvent, which process comprises converting in a devolatilization extruderan admixture of brominated styrenic polymer typically having a bromine content of at leastabout 50 wt%, preferably at least about 60 wt%, and more preferably at least about 67 wt%,and a vaporizable organic solvent into a brominated styrenic polymer melt or flow and aseparate vapor phase comprised predominately of vaporizable organic solvent, allowing orcausing said melt or flow of brominated styrenic polymer while in the form of a melt or flowto pass from the devolatilization extruder through a die thereby producing emerging strandsof brominated styrenic polymer melt or flow, allowing or causing said strands to solidify, andsubdividing the strands into solidified pellets of brominated styrenic polymer.

[0030] 3) A process for producing pelletized brominated styrenic polymers from a solution in a vaporizable solvent, which process comprises: > converting in a devolatilization extruder, an admixture of brominated styrenicpolymer, preferably an admixture of brominated anionic styrenic polymer, and avaporizable organic solvent into a melt or flow of brominated styrenic polymer,preferably a melt or flow of brominated anionic styrenic polymer, and a separatevapor phase of said solvent; > extruding the melt or polymer flow from the devolatilization extruder through a dieto produce traveling strand(s) of extruded polymer melt or polymer flow; > enabling and/or causing such traveling strand(s) to solidify and he broken, subdivided,or otherwise converted into pellets of the brominated styrenic polymer; and > subjecting the pellets to size classification to remove and recover from such product(a) oversized particles, if any, and (b) fines, if any, that may be present in suchproduct.

The first mentioned step of this embodiment, that of converting a solution of brominatedstyrenic polymer into a melt or polymer flow of brominated styrenic polymer in adevolatilization extruder, can be, and preferably is, conducted as in the above-describedproduct recovery embodiments. Also by preheating the solution or concentrating the solutionby use of flash distillation before feeding the more concentrated solution to thedevolatilization extruder, the above-described advantages of reducing the amount of solventto be removed by, and reducing the heat energy requirements of the devolatilization extruderto produce the polymer melt or polymer flow, can be achieved. 10 WO 2008/011477 PCT/US2007/073805 [0031] Apart from the advantages afforded by pre-concentrating and/or preheating thebrominated styrenic polymer solution, an advantage of tlie foregoing pelletizing embodimentof this invention is the fact that it is possible to use unadulterated brominated styrenicpolymers, such as unadulterated brominated anionic styrenic polymers, and thereby formpellets of unadulterated brominated styrenic polymers, such as unadulterated brominatedanionic styrenic polymers which have desirable properties such as improved hardness andreduced fines-producing tendencies during manufacture, handling, storage, and use.

[0032] 4) A process for the preparation of a brominated styrenic polymer in pelletized form, which process comprises: > brominating a styrenic polymer under superatmo spheric pressure in a vaporizableorganic solvent and in the presence of a Lewis acid bromination catalyst, and in aclosed reaction system in which substantially all of the hydrogen halide coproduct isretained in the reaction mixture; > quenching the catalyst to thereby form (i) an organic phase containing dissolvedbrominated styrenic polymer and (ii) an aqueous phase containing hydrogen halide; > separating phases (i) and (ii) from each other, and if phase (i) has a viscosity less thanextrudable viscosity, concentrating organic phase of (i) to form an admixture ofextrudable viscosity; > continuously introducing organic phase of (i) or admixture of extrudable viscosity intothe liquids inlet portion of an operating devolatilization extruder having a liquids inletportion and a polymer melt or polymer flow outlet portion and at least two sectionsthat can be operated (a) at temperatures that differ from each other, and (b) underpressures that differ from each other, one of the at least two sections being disposedupstream from the other of the at least two sections, the devolatilization extruderhaving vapor collecting apparatus adapted to collect volatiles formed in these at leasttwo sections; and > operating said section disposed downstream at higher temperature and lower pressureconditions than the temperature and pressure conditions of said section disposedupstream, so that (a) a flowable polymer melt or polymer flow of said polymer isformed within the devolatilization extruder and can leave from the at least onepolymer melt or polymer flow outlet, and (b) volatiles composed predominately of thesolvent released from the polymer in said at least two sections are collected by saidvapor collecting apparatus; > having said polymer melt or polymer flow leaving the devolatilization extruder passthrough a die to produce one or more traveling continuous strands of extrudedpolymer melt or polymer flow; > enabling and/or causing such continuous traveling strand(s) to solidify and be broken,subdivided, or otherwise converted into pellets of the brominated styrenic polymer. 11 WO 2008/011477 PCT/US2007/073805

SOME FURTHER EMBODIMENTS OF THIS INVENTION FOR PRODUCING

PELLETIZED PRODUCTS

[0033] Still other embodiments of this invention relate to: > new pelletized unadulterated brominated styrenic polymers and preferably, newunadulterated pelletized brominated anionic styrenic polymers, having superiorhardness and/or crush strength properties; > novel continuous processes for the production of highly pure melts or flows ofbrominated anionic styrenic polymer (especially brominated anionic polystyrene)using as raw materials (1) anionic styrenic polymer (especially anionic polystyrene), (2) brominating agent (especially bromine), (3) Lewis acid catalyst (especiallyaluminumhalide catalyst in which the halogen atoms are bromine and or chlorine, and (4) vaporizable organic solvent (especially vaporizable halogenated solvent); > novel continuous processes for the production of highly pure pellets of brominatedanionic styrenic polymer (especially brominated anionic polystyrene), using as rawmaterials (1) anionic styrenic polymer (especially anionic polystyrene), (2)brominating agent (especially bromine), (3) Lewis acid catalyst (especially aluminumhalide catalyst in which the halogen atoms are bromine and or chlorine, and (4)vaporizable organic solvent (especially vaporizable halogenated solvent); > new pelletized brominated anionic styrenic polymers (especially, new unadulteratedpelletized brominated anionic styrenic polymers), having reduced levels of ionicbromine (/. e., bromide) content, as well as superior hardness and/or crush strengthproperties.

[0034] In the various embodiments of this invention the extrudate from the devolatilizationextruder typically has an average of less than about 10,000 ppm (wt/wt), and preferably lessthan about 5000 ppm (wt/wt), and still more preferably less than about 1000 ppm (wt/wt) ppmof the organic solvent in steady-state operation and thus has desirable hardness and strengthproperties with attendant reduced fmes-forming tendencies.

SOME EMBODIMENTS INVOLVING FORMING GRANULES OR PASTILLES OFBROMINATED STYRENIC POLYMER

[0035] These embodiments comprise a process of producing granules or pastilles ofunadulterated brominated anionic styrenic polymer, which process comprises: > converting in a devolatilization extruder, an admixture of brominated styrenicpolymer and a vaporizable organic solvent into a melt or flow of brominated anionicstyrenic polymer and a separate vapor phase of said solvent; and > forming from said melt or flow a downwardly oriented plug flow from at least oneorifice in a manifold or nozzle that is in proximity to a cooled traveling planar 12 WO 2008/011477 PCT/US2007/073805 member, said planar member being impervious to cooling liquid and having an upperand lower surface, whereby there is a gap between the lower portion of the orifice andsaid upper surface, so that at least a portion of a plug of molten unadulteratedbrominated anionic styrenic polymer either (i) bridges said gap and forms a separateindividual granule or pastille on the upper surface of said planar member, or (ii) freelydrops from the lower portion of the orifice and falls upon the upper surface of saidplanar member and forms an individual granule or pastille on the upper surface of saidplanar member, said traveling member being cooled by a mist or spray of coolingliquid contacting the lower surface of said planar member.

[0036] In this process, the traveling planarmember is preferably an endless belt imperviousto cooling liquid such as an endless steel belt. In the operation at least a portion of the plugof molten unadulterated brominated anionic styrenic polymer bridges said gap and forms aseparate individual granule or pastille on the upper surface of said planar member, or at leasta portion of such plug of molten unadulterated brominated anionic styrenic polymer freelydrops from the lower portion of the orifice and falls upon the upper surface of the planarmember and forms an individual granule or pastille on the upper surface of the planarmember. It is also possible to operate such that (a) at least a portion of said plug of moltenunadulterated brominated anionic styrenic polymer bridges said gap and forms a separateindividual granule or pastille on the upper surface of said planar member; or wherein (b) atleast a portion of said plug of molten unadulterated brominated anionic styrenic polymerfreely drops from the lower portion of the orifice and falls upon the upper surface of saidplanar member and forms an individual granule or pastille on the upper surface of said planarmember; (a) and (b) occurring in an alternating or random manner.

[0037] Although other cooling liquids can be employed, said mist or spray of cooling liquidis preferably a mist or spray of cooling water. The mist or spray is preferably applied to thelower surface of said planar member below the region in which the separate individualgranule or pastille is formed on the upper surface of said planar member.

[0038] Another embodiment of this invention is an overall process for producingbrominated anionic styrenic polymer in the form of granules or pastilles of unadulteratedbrominated anionic styrenic polymer. Such process comprises: > brominating an anionic styrenic polymer under superatmospheric pressure in avaporizable solvent and in the presence of a Lewis acid bromination catalyst, and ina closed reaction system in which substantially all of the hydrogen halide coproductis retained in the reaction mixture; > quenching the catalyst to thereby form (i) an organic phase containing dissolvedbrominated styrenic polymer and (ii) an aqueous phase containing hydrogen halide; > separating phases (i) and (ii) from each other, and if phase (i) has a viscosity less than 13 WO 2008/011477 PCT/US2007/073805 extrudable viscosity, concentrating organic phase of (i) to form an admixture of extrudable viscosity; > continuously introducing organic phase of (i) or admixture of extrudable viscosity intothe liquids inlet portion of an operating devolatilization extruder having a liquids inletportion and a polymer melt or polymer flow outlet portion and at least two sectionsthat can be operated (a) at temperatures that differ from each other, and (b) underpressures that differ from each other, one of the at least two sections being disposedupstream from the other of the at least two sections, the devolatilization extruderhaving vapor collecting apparatus adapted to collect volatiles formed in these at leasttwo sections; > operating said section disposed downstream at higher temperature and lower pressureconditions than the temperature and pressure conditions of said section disposedupstream, so that (a) a flowable polymer melt or polymer flow of said polymer isformed within the devolatilization extruder and released from the at least one polymermelt or polymer flow outlet, and (b) volatiles composed predominately of the solventreleased from the polymer in said at least two sections are collected by said vaporcollecting apparatus; > forming from said flowable polymer melt or polymer flow of said polymer adownwardly oriented plug flow from at least one orifice in a manifold or nozzle thatis in proximity to a cooled traveling planar member, said planar member beingimpervious to cooling liquid and having an upper and lower surface, whereby thereis a gap between the lower portion of the orifice and said upper surface, so that at leasta portion of a plug of molten unadulterated brominated anionic styrenic polymer either (i) bridges said gap and forms a separate individual granule or pastille on the uppersurface of said planar member, or (ii) freely drops from the lower portion of the orificeand falls upon the upper surface of said planar member and forms an individualgranule or pastille on the upper surface of said planar member, said traveling memberbeing cooled by a mist or spray of cooling liquid contacting the lower surface of saidplanar member.

[0039] In this embodiment, the traveling planar member is preferably an endless beltimpervious to cooling liquid, and more preferably is an endless steel belt. In addition, themist or spray of cooling liquid is preferably a mist or spray of cooling water. The mist orspray is preferably applied to the lower surface of said planar member below the region inwhich the separate individual granule or pastille is formed on the upper surface of said planarmember. 14 WO 2008/011477 PCT/US2007/073805

BROMINATED STYRENIC POLYMER

[0040] Styrenic polymers which are brominated to form the brominated styrenic polymers recovered and/or pelletized pursuant to this invention are one or more homopolymers and/or copolymers of one or more vinyl aromatic monomers. Preferred vinyl aromatic monomers have the formula: H2C=CR-Ar wherein R is a hydrogen atom or an alkyl group having from 1 to 4 carbon atoms and Ar isan aromatic group (including alkyl-ring substituted aromatic groups) of from 6 to 10 carbonatoms. Examples of such monomers are styrene, alpha -methylstyrene, orth o-methylstyrene,meta-methylstyrene, para -methylstyrene, /?«/O~ethylstyrene, isoprop eny Ito luene,vinylnaphthalene, isopropenylnaphthalene, vinylbiphenyl, vinylanthracene, thedimethylstyrenes, and tert-butylstyrene. Polystyrene is the preferred reactant. When thebrominated styrenic polymer is made by bromination of a copolymer of two or more vinylaromatic monomers, it is preferred that styrene be one of the monomers and that styrenecomprise at least 50 weight percent and preferably at least about 80 weight percent of thecopolymerizable vinyl aromatic monomers. The terms "vinylaromatic” and "styrenic” inconnection with monomer(s) or polymer(s) are used interchangeably herein.

[0041] The aromatic pendant constituents of the styrenic polymer to be brominated can bealkyl substituted or substituted by bromine or chlorine atoms, but preferably will not be sosubstituted. Typically, anionic styrenic polymers used to produce the brominated anionicstyrenic polymers used in the practice of this invention will have a GPC weight averagemolecular weight (Mw) in the range of about 2000 to about 200,000, preferably in the rangeof about 3000 to about 10,000, and more preferably in the range of about 3000 to about 7000.The polydispersity of such anionic styrenic polymers will typically be in the range of between1 and about 4, and more preferably in the range of between 1 and about 2. Typically, styrenicpolymers produced by free radical polymerization that are used to produce the brominatedstyrenic polymers using a process of this invention will have a GPC weight average molecularweight (Mw) in the range of about 30,000 to about 500,000, preferably in the range of about50,000 to about 300,000, and more preferably in the range of about 150,000 to about 250,000.The polydispersity of such styrenic polymers produced by free radical polymerization willtypically be in the range of between 1 and about 10. All of the foregoing Mw andpolydispersity values are based on gel permeation chromatography (GPC) techniques whichare hereinafter described.

[0042] The polymers which are converted into unadulterated pelletized form pursuant to this invention are a single brominated styrenic polymer or a blend of two or more brominated styrenic polymers, preferably a single brominated anionic styrenic polymer or a blend of two or more brominated anionic styrenic polymers. The foregoing blends can be of brominated 15 196429/2 homopolymers only, brominated copolymers only, or at least one brominated homopolymer and atleast one brominated copolymer of styrenic monomer(s). Desirably, the bromine content of allsuch polymers is at least about 50 percent by weight, although styrenic polymers with lowerbromine contents can readily be produced by this invention. Preferably polymers of these typeshave a bromine content of at least about 60 wt%, more preferably of at least about 64 wt%, stillmore preferably at least about 67 wt%, and even more preferably at least about 68 wt%. Usuallythe maximum bromine content is about 71 wt% with polymers having a maximum of about 70 wt%bromine being more preferred. As between homopolymers and copolymers, brominatedpolystyrene polymers made by free radical polymerization are preferred and brominated anionicpolystyrene polymers are more preferred.

[0043] Methods for the production of styrenic polymers by free radical polymerization processesare well known in the art and reported in the literature. See for example Encyclopedia of PolymerScience and Engineering, volume 16, John Wiley and Sons, 1989, pages 46-62. For convenience,the term "free-radically produced styrenic polymer" or "free-radically produced polystyrene",whether in the singular or plural, is used in the claims to denote that the styrenic polymer orpolystyrene being referred to was produced previously before bromination by use of, or by anotherparty's use of, a free radical polymerization process. Methods for the preparation of anionicstyrenic polymers such as anionic polystyrene are also known in the art and reported in theliterature. See for example, U.S. Pat. Nos. 3,812,088; 4,200,713; 4,442,273; 4,883,846; 5,391,655;5,717,040; and 5,902,865. An especially preferred method is described in commonly-owned U.S.Pat. No. 6,657,028, issued December 2, 2003.

[0044] Bromination processes which can be used for producing a brominated anionic styrenicpolymer are disclosed in U.S. Pat. Nos. 5,677,390; 5,686,538; 5,767,203; 5,852,131; 5,852,132;5,916,978; 6,133,381; 6,207,765; 6,232,393; 6,232,408; 6,235,831; 6,235,844; 6,326,439; and6,521,714.

[0045] In all embodiments of this invention the preferred brominated styrenic polymers formedand/or used are brominated anionic styrenic polymers, and of the brominated anionic styrenicpolymers, brominated anionic polystyrene is especially preferred.

[0046] Typical properties of a desirable commercially-available brominated polystyrene for use inpreparing the pellets of this invention, where the polystyrene used was produced by free radicalpolymerization, include the following:

Appearance/form - off-white powder or granules formed by powder compactionBromine Content - 68,5 wt%

Tg(EC)-182 16 WO 2008/011477 PCT/US2007/073805

Specific gravity (@ 23 °C) - 2.15 TGA (TA instruments model 2950, 10°C/min. under N2): 1% weight loss, °C - 3465% weight loss, °C - 37510% weight loss, °C - 38350% weight loss, °C- 39990% weight loss, °C - 435

Such brominated polystyrene is presently available from Albemarle Corporation under thedesignation SAYTEX HP-701 OP flame retardant. A powder-compacted granular form ofsuch brominated polystyrene is presently available from Albemarle Corporation under thedesignation SAYTEX® HP-7010G flame retardant. (0047J Typical properties of a preferred brominated anionic polystyrene for use in preparingthe pellets of this invention include the following:

Appearance/form - white powder or pellet formed by melt extrusion of powderBromine Content - 67 to 71 wt%

Melt flow index (220°C. 2.16 kg) - 4 to 35 g/10 minTg(°C)-170

Specific gravity (@ 23C) - 2.2 TGA (TA instruments model 2950, 10 ° C/min. under N2): 1% weight loss, °C - 3615% weight loss, °C - 38610% weight loss, °C - 39450% weight loss, °C-41790% weight loss, °C-435

Methods for preparing brominated polystyrene having the above properties are described inU.S. Pat. No. 6,521,714. Brominated anionic polystyrene is presently available in the formof granules from Albemarle Corporation under the designation SAYTEX HP 3 010G flame retardant. Such granules are formed by melt extrusion of powder and are not prepared by the (£) process of this invention. SAYTEX HP 3010P flame retardant is the powder form of brominated anionic polystyrene produced by Albemarle Corporation. 17 WO 2008/011477 PCT/US2007/073805

SOLVENTS

[0048] The solvents present in the solutions of brominated styrenic polymers used in thevarious embodiments of this invention can be any liquid solvent that is capable of beingvaporized at a temperature below that at which the brominated styrenic polymer dissolvedtherein would begin to undergo thermal degradation, and that does not adversely react withthe brominated styrenic polymer dissolved therein. Typically the solvent is composed of oneor more halogenated solvents that have boiling temperatures below about 150°C atatmospheric pressures. Typical halogenated solvents are those in which each halogen atomis a bromine atom or a chlorine atom or in which the solvent contains at least one bromineatom and at least one chlorine atom. Less preferred are solvents containing one or morehalogen atoms other than bromine atoms and/or chlorine atoms. A feature of this inventionis that the solvent can be the solvent in which the brominated styrenic polymer was formedby bromination of a styrenic polymer in the presence of a Lewis acid catalyst. Illustrativeexamples of such processes are set forth in the patents cited at the outset of this specification.However if desired, a solvent exchange procedure can be used to replace the initial solventwith a different vaporizable solvent at any suitable stage prior to feeding into adevolatilization extruder. The term "vaporizable" simply means that the solvent should boilat a temperature below that at which the particular brominated styrenic polymer dissolvedtherein would begin to undergo an unacceptable amount of thermal degradation. Thistemperature will of course vary from case to case depending upon such factors as the type ofbrominated styrenic polymer present in the solvent, the length of time the solution is at athreshold decomposition temperature, and the quality control specifications imposed upon thefinal brominated styrenic polymer product. Non-limiting examples of suitable organicsolvents include dichloromethane, dibromomethane, bromochloromethane,bromotrichloromethane, chloroform, carbon tetrachloride, 1,2-dibromoethane, 1,1-dibromoethane, l-bromo-2-chloroethane, 1,2-dichloroethane, 1,2-dibromopropane, 1-bromo- 3-chloropropane, 1-bromobutane, 2-bromobutane, 2-bromo-2-methylpropane, 1-bromopentane, l-bromo-2-methylbutane, 1-bromohexane, 1-bromoheptane,bromocyclohexane, and liquid isomers, homologs, or analogs thereof. Liquid mixtures of twoor more such compounds can be used. Bromochloromethane is a particularly preferredsolvent. If a solvent exchange procedure is used, such halogenated solvent can be replacedfor example by a vaporizable liquid aromatic hydrocarbon solvent.

DRYING AND CONCENTRATING INITIAL SOLVENT SOLUTION

[0049] In the embodiments of this invention involving processes for recovery of brominated styrenic polymers as a melt or flow for subsequent use and in the embodiments of this invention involving processes forpelletizing brominated styrenic polymers where the solution 18 WO 2008/011477 PCT/XJS2007/073805 contains some water, it is desirable to "dry" the solution by freeing it of most, if notessentially all, of the water. For example, when a reaction mixture is formed from Lewisacid-catalyzed bromination of a styrenic polymer in a suitable organic solvent such ashalogenated hydrocarbon or halocarbon solvent, the catalyst is typically deactivated byquenching the reaction mixture with an aqueous quenching solution such as water by itself.After a phase cut to separate the organic phase of brominated styrenic polymer in organicsolvent from the aqueous phase, some water typically remains in such organic phase. Toremove such water the "wet" organic phase (/. e., organic phase which contains along with thebrominated styrenic polymer, some residual amount of water, e.g., ca. 1500 ppm of water),is preferably passed through a coalescer to effect separation of at least a large portion of thefree water, e.g., to a level of ca. 300 ppm or less of water). If the resultant "dried" solutionof brominated styrenic polymer in the organic solvent contains less than about 40 wt% ofbrominated styrenic polymer, such solution is preferably subjected to distillation, morepreferably a flash distillation, to remove organic solvent as a collectable vapor phase alongwith any water retained by the polymer solution. In this way a more concentrated essentiallyanhydrous organic solution containing at least about 50 wt% of brominated styrenic polymeris formed. Such more highly concentrated solution is ideally suited for use as the feed to thedevolatilization extruder.

[0050] The technology for coalescing filtration, including coalescing filtration for separatingwater from organic liquid systems, is well known and reported in the literature, and systemsfor separating water from organic liquid systems are available from various commercialsuppliers. Suitable filter media for effecting such separations include fiberglass, ceramics,and sand. The use of a bed of sand is a preferred medium for use in embodiments of thepresent invention in which coalescing filtration is to be employed.

RECOVERY OF BROMINATED STYRENIC POLYMERS FROM SOLVENT

[0051] In the various processes of this invention for recovering brominated styrenicpolymers from a solution in an organic solvent, some of which processes have been describedabove, the product as initially recovered from the devolatilization extruder is in the form ofa melt or is in at least a soft flowable form. The melt can be cooled or allowed to cool andthen can be converted (e.g., by molding) into various shapes or configurations for storage andshipment or it can be pulverized into particulate form or fine powder form. In order toconvert the polymer melt or polymer flow directly into pelletized form, use of the processembodiment of this invention devoted to preparing pelletized brominated styrenic polymersis especially preferred. However, if desired, the pelletizing process described in commonly-owned published PCT patent application WO 2005/118245 can be used from dry powderedbrominated styrenic polymer as pellets made by that process are of good quality. However,based on available test results, pellets made pursuant to this invention are even better than 19 WO 2008/011477 PCT/US2007/073805 those produced according to WO 2005/118245, especially in hardness and/or high crush strength.

[0052] Recovery of brominated styrenic polymers from solution by an embodiment of thisinvention involves selection and operation of a devolatilization extruder in a suitable mannersuch as described herein so that the solvent is vaporized in and can be, and preferably is,collected from the extruder. Preferably the recovered solvent is reused by recycling to aprocess in which styrenic polymer is brominated using a Lewis acid catalyst. In an especiallypreferred embodiment of this invention a process is provided comprising conducting thebromination of a styrenic polymer in a liquid phase reaction mixture under superatmosphericpressure in a closed reaction system so that gaseous hydrogen halide (HX, where X is abromine or chlorine atom) coproduct is not released from said closed reaction systemseparately and apart from such reaction mixture until the reaction has been terminated byquenching the reaction mixture in an aqueous quenching medium which destroys the catalystand dissolves the HX forming hydrobromic acid or if BrCl is used as the brominating agent,hydrochloric acid. The organic phase containing the brominated styrenic polymer and theaqueous phase containing the HX are separated from each other by a phase separationprocedure such as settling and draining off the lower phase or siphoning off the upper phase.Preferably additional aqueous washes are carried out to more completely remove residual HXand any inorganic salts that may be present. If desired, the organic phase may be subjectedto coalescing filtration to achieve essentially complete separation of the aqueous phase fromthe organic phase. After concentrating the organic phase containing the brominated styrenicpolymer, the more concentrated organic phase is then introduced into a devolatilizationextruder wherein the solvent is vaporized and recovered, and a melt or polymer flow of theessentially solvent free brominated styrenic polymer is released from the extruder. In caseswhere HX in the aqueous phase is HBr, it is preferred to thereafter recover the bromine valuesfrom the aqueous phase by (i) steam stripping the aqueous phase to remove residual organicsolvent from the aqueous phase and thereby provide a hydrobromic acid product suitable foruse or sale; (ii) converting the HBr in the aqueous phase to elemental bromine; or (iii) reactingthe HBr with an aqueous metallic base to produce a solution of a metal bromide salt suitablefor use or sale.

[0053] Thus in accordance with another embodiment of this invention there is provided aprocess for the preparation of a brominated styrenic polymer, typically having a brominecontent of at least about 50 wt%, and preferably at least about 60 wt%, and still morepreferably at least about 67 wt% in the form of a melt or polymer flow, which processcomprises: > brominating a styrenic polymer under superatmospheric pressure in a vaporizable solvent and in the presence of a Lewis acid bromination catalyst, and in a closed 20 WO 2008/011477 PCT/US2007/073805 reaction system in which substantially all of the hydrogen halide coproduct is retained in the reaction mixture; > quenching the catalyst to thereby form (i) an organic phase containing dissolvedbrominated styrenic polymer, and (ii) an aqueous phase containing hydrogen halide; > separating phases (i) and (ii) from each other, using coalescing filtration, if desired,to attain essentially complete separation of phases, and if phase (i) has a viscosity lessthan extrudable viscosity, concentrating organic phase of (i) to form and admixtureof extrudable viscosity, such concentration preferably being accomplished by use ofdistillation or flash distillation; > continuously introducing organic phase of (i) or admixture of extrudable viscosity intothe liquids inlet portion of an operating devolatilization extruder having a liquids inletportion and a polymer melt or polymer flow outlet portion and at least two sectionsthat can be operated (a) at temperatures that differ from each other, and (b) underpressures that differ from each other, one of the at least two sections being disposedupstream from the other of the at least two sections, the devolatilization extruderhaving vapor collecting apparatus adapted to collect volatiles formed in these at leasttwo sections; and > operating said section disposed downstream at higher temperature and lower pressureconditions than the temperature and pressure conditions of said section disposedupstream, so that (a) a flowable polymer melt or polymer flow of said polymer isformed within the devolatilization extruder and released from the at least one polymermelt or polymer flow outlet, and (b) volatiles composed predominately of the solventreleased from the polymer in said at least two sections can be, and preferably are,collected by said vapor collecting apparatus, the polymer melt or polymer flow ofsuch brominated styrenic polymer leaving from the outlet portion of thedevolatilization extruder containing an average of less than about 10,000 ppm (wt/wt),and preferably less than about 5000 ppm (wt/wt), and still more preferably less thanabout 1000 ppm (wt/wt) of the organic solvent during steady-state operation.

The quenching in the above embodiment can be conducted in the reactor in which a batch ofthe brominated styrenic polymer has just been prepared or more preferably in a separatevessel. When the bromination is conducted on a continuous basis, the bromination reactionproduct is continuously transmitted while under pressure into a separate vessel or zone andinto contact in such vessel or zone with an aqueous quenching medium, preferably water.During the quenching the catalyst residues tend to collect in the aqueous phase and essentiallyall of the hydrogen halide is taken up in the water. After conducting the phase separationbetween (i) and (ii) in the above embodiment and before effecting the introduction into theliquids inlet portion of the devolatilization extruder, it is preferable to subject the organic 21 WO 2008/011477 PCT/US2007/O73805 phase of (i) to coalescing filtration in order to remove entrained water containing dissolved salt(s) from the organic phase containing the brominated styrenic polymer.

PRODUCTION OF PELLETS

[0054] Among the various embodiments of this invention is a process for producingpelletized brominated styrenic polymers from an admixture of brominated styrenic polymerand a vaporizable solvent, which process comprises: > optionally forming an admixture of extrudable viscosity comprising brominatedstyrenic polymer and a vaporizable organic solvent, preferably a vaporizablehalogenated organic solvent, from a less concentrated admixture thereof having abrominated styrenic polymer content of 40 wt% or less, the vaporizable organicsolvent preferably being a halogenated solvent in which the brominated styrenicpolymer was formed by bromination of a styrenic polymer in the presence of a Lewisacid catalyst; > continuously introducing an admixture of extrudable viscosity comprising brominatedstyrenic polymer and a vaporizable organic solvent, into the liquids inlet portion ofan operating devolatilization extruder having a liquids inlet portion and a polymermelt or polymer flow outlet portion and at least two sections that can be operated (a)at temperatures that differ from each other, and (b) under pressures that differ fromeach other, one of the at least two sections being disposed upstream from the other ofthe at least two sections, the devolatilization extruder having vapor collectingapparatus adapted to collect volatiles formed in these at least two sections; > operating said section that is disposed downstream at higher temperature and lowerpressure conditions than the temperature and pressure conditions of said section thatis disposed upstream, so that (a) a flowable melt or flow of said polymer is formedwithin the devolatilization extruder and forcibly released from the polymer melt orpolymer flow outlet, and (h) volatiles composed predominately of the solvent releasedfrom the polymer in said at least two sections can be, and preferably are, collected bysaid vapor collecting apparatus, the polymer melt or polymer flow of such brominatedstyrenic polymer that exits from the outlet portion of the devolatilization extrudercontaining an average of less than about 10,000 ppm (wt/wt), and preferably less thanabout 5000 ppm (wt/wt), and still more preferably less than about 1000 ppm (wt/wt)of the organic solvent in steady-state operation; > having the polymer melt or polymer flow from the devolatilization extruder passthrough a die to produce traveling strand(s) of extruded polymer melt or polymerflow; > enabling and/or causing such traveling strand(s) to solidify (e.g., by enabling and/or 22 WO 2Θ08/Θ11477 PCT/US2007/073805 causing a sufficient reduction in the temperature of the traveling strand(s)) and bebroken, subdivided, or otherwise converted into pellets of the brominated styrenicpolymer (e.g., by providing a vacuum system under the conveyor belt or web to drawair downwardly over and around the strands on the web, and by applying jets of waterdownwardly onto the strands traveling on the conveyor belt or web of sufficient forceto cause at least some breakage of the strands, the porosity of the belt or web allowingthe water to pass downwardly through the web hut of fine enough porosity to retainthe broken, subdivided, or pelletized polymer strands on the belt or web and enablingand/or causing broken, subdivided, or pelletized polymer strands to fall from the beltor web into a size classifier whereby the impact from the fall may cause someadditional breakage of strand pieces to occur); > subjecting the pellets to size classification (e.g., by use of appropriate screeningtechniques) to remove and recover from such product (a) oversized particles, if any,and (b) fines, if any, that may be present in such product.

In the above process it is preferred to collect oversized particles and fines that may result fromthe size classification and recycle them for example into the liquids inlet portion of thedevolatilization extruder, to any other suitable inlet in an upstream portion of such extruder,or to the polymer melt or polymer flow passing into the die so that the particles and finesbecome part of the polymer melt or polymer flow. When using the above optional first step,it is preferable to subj ect the less concentrated solution to flash distillation to thereby form thedesired more concentrated solution, and also to recycle halogenated solvent collected by thevapor collecting apparatus of the devolatilization extruder as at least part of the solvent usedin ensuing bromination of styrenic polymer.

[0055] Still another embodiment of this invention is a process for producing pelletizedbrominated styrenic polymers, which process comprises: > feeding a solution containing at least about 50 wt% of brominated styrenic polymerdissolved a vaporizable solvent into a devolatilization extruder that is adapted andoperated to separate vaporizable solvent from said polymer and form as extrudate apolymer melt or polymer flow of said polymer; > having the extrudate pass through a die to thereby form one or more traveling strandsof molten unadulterated brominated styrenic polymer, preferably unadulteratedanionic styrenic polymer; and > pelletizing such strands by enabling and/or causing such traveling strand(s) to solidify(e.g., by enabling and/or causing a sufficient reduction in the temperature of thetraveling strand(s)) and be broken, subdivided, or otherwise converted into pellets ofthe brominated styrenic polymer (e.g., by providing a vacuum system under theconveyor belt or web to draw air downwardly over and around the strands on the web, 23 WO 2008/011477 PCT/US2007/073805 and by applying jets of water downwardly onto the strands traveling on the conveyorbelt or web of sufficient force to cause at least some breakage of the strands, theporosity of the belt or web allowing the water to pass downwardly through the webbut of fine enough porosity to retain the broken, subdivided, or pelletized polymerstrands on the belt or web and enabling and/or causing broken, subdivided, orpelletized polymer strands to fall from the belt or web into a size classifier wherebythe impact from the fall may cause some additional breakage of strand pieces tooccur); and > subjecting the pellets to size classification (e.g., by use of appropriate screeningtechniques) to remove and recover from such product (a) oversized particles, if any,and (b) fines, if any, that may be present in such product.

[0056] Yet another embodiment of this invention is a process for the preparation of apelletized brominated styrenic polymer typically having a bromine content of at least about50 wt%, and preferably at least about 60 wt%, and still more preferably at least about 67 wt%in the form of a polymer melt or polymer flow, which process comprises: > brominating a styrenic polymer under superatmospheric pressure in a vaporizablesolvent and in the presence of a Lewis acid bromination catalyst, and in a closedreaction system in which substantially all of the hydrogen halide coproduct is retainedin the reaction mixture; > quenching the catalyst to thereby form (i) an organic phase containing dissolvedbrominated styrenic polymer having a bromine content as aforesaid and (ii) anaqueous phase containing hydrogen halide; > separating such phases from each other, and preferably subjecting the organic phasecontaining dissolved brominated styrenic polymer to a coalescing filtration; > concentrating the organic phase containing dissolved brominated styrenic polymer toa viscosity suitable for use in a devolatilization extruder; > continuously introducing organic phase containing dissolved brominated styrenicpolymer into the liquids inlet portion of an operating devolatilization extruder havinga liquids inlet portion and a polymer melt or polymer flow outlet portion and at leasttwo sections that can be operated (a) at temperatures that differ from each other, and (b) under pressures that differ from each other, one of the at least two sections beingdisposed upstream from the other of the at least two sections, the devolatilizationextruder having vapor collecting apparatus adapted to collect volatiles formed in theseat least two sections; > operating said section disposed downstream at higher temperature and lower pressureconditions than the temperature and pressure conditions of said section disposedupstream, so that (a) a flowable polymer melt or polymer flow of said polymer is 24 WO 2008/011477 PCT/US2O07/073805 formed within the devolatilization extruder and released from the polymer melt or polymer flow outlet, and (b) volatiles composed predominately of the solvent released from the polymer in said at least two sections can be, and preferably are, collected by said vapor collecting apparatus, the polymer melt or polymer flow of such brominated 5 styrenic polymer that has exited from the outlet portion of the devolatilization extruder containing an average of less than about 10,000 ppm (wt/wt), and preferably less thanabout 5000 ppm (wt/wt), and still more preferably less than about 1000 ppm (wt/wt)of the organic solvent in steady-state operation; > having the polymer melt or polymer flow from the devolatilization extruder pass 10 through a die to produce traveling strand(s) of extruded polymer melt or flow; > enabling and/or causing such traveling strand(s) to solidify (e.g., by enabling and/orcausing a sufficient reduction in the temperature of the traveling strand(s)) and bebroken, subdivided, or otherwise converted into pellets of the brominated styrenicpolymer (e.g., by providing a vacuum system under the conveyor belt or web to draw 15 air downwardly over and around the strands on the web, and by applying jets of water downwardly onto the strands traveling on the conveyor belt or web of sufficient forceto cause at least some breakage of the strands, the porosity of the belt or web allowingthe water to pass downwardly through the web but of fine enough porosity to retainthe broken, subdivided, or pelletized polymer strands on the belt or web and enabling 20 and/or causing broken, subdivided, or pelletized polymer strands to fall from the belt or web into a size classifier whereby the impact from the fall may cause someadditional breakage of strand pieces to occur); and > subjecting the pellets to size classification (e.g., by use of appropriate screeningtechniques) to remove and recover from such product (a) oversized particles, if any, 25 and (b) fines, if any, that may be present in such product.

DEVOLA T1LIZA TION EXTRUDER

[0057] In conducting the various processes of this invention, commercially availabledevolatilization extruders can be successfully adapted for use in practicing such processes.The extruder can be of single screw configuration, co-rotating twin screw configuration, or 30 counter-rotating twin screw configuration. Twin screw non-intermeshing counter-rotating devolatilization extruders are preferred. The machine should be equipped with a liquids inletportion at the feed portion of the extruder and a polymer melt or flow outlet portion at thedischarge portion of the extruder. It should also have along the length of the screw(s) at leasttwo housing sections, and preferably four or more housing sections, that can be independently 35 operated (a) at temperatures (preferably adjustable temperatures) that differ from each other and(b) pressures (preferably adjustable pressures) that differ from each other. At least some of the midstream or downstream sections must be able, and preferably all of the sections 25 WO 2008/011477 PCT/US2007/073805 should be able, to provide internal temperatures high enough to form a polymer melt or polymer flow of the brominated styrenic polymer(s) to be used in the machine. Typically varying temperatures of up to about 350 ° C will suffice. The heat generated by friction within the machine should of course be taken into consideration in setting the temperatures of thesegments or zones in which the polymer melt or polymer flow is being processed by themachine. Also at least some of the midstream or downstream sections, and preferably all ofthe sections, should be adapted to independently operate at reduced pressures in the range ofabout 1 to about 500 mm of Hg. The devolatilization extruder should be used in conjunctionwith vapor collecting apparatus adapted to collect all volatiles formed in each ofthe sections.The pitch of the forward-flighted screw elements should be adapted to provide a continuousflow of the contents of the extruder to maximize production rate. If necessary, or desirable,because ofthe characteristics of the particular brominated styrenic polymer to be processed,the screw elements may also contain reverse-flighted elements for more intensive mixingand/or cylindrical elements to create a seal. The manufacturers of such machines can adaptthe type and/or pitch of the screws to achieve satisfactory rates of flow and mixing once theyare provided with samples of the particular brominated styrenic polymer to be processed ina suitable devolatilization extruder. Continuous operation of the devolatilization extruder isthe especially preferred mode of operation, although it is possible to practice at least some ofthe processes of this invention, e.g., processes for recovery of brominated styrenic polymersfrom solutions, as batch operations.

[0058] Use may be made of devolatilization extruder machines provided by commercialmanufacturers of such equipment.

[0059] For anyone unfamiliar with extruders including devolatilization extruders, theirdesign and their operation, reference may be made to Chris Rauwendaal, Polymer Extrusion,4th Edition, Hanser Gardner Publications, Inc., Cincinnati, Ohio for further details known andavailable to those of ordinary skill in that art. See also U.S. Pat. Nos. 3,082,816 and4,110,843.

ILLUSTRATIVE PREFERRED PROCESS EMBODIMENT

[0060] A devolatilization extruder is operated at a suitable temperature and pressure profileto cause the brominated anionic styrenic polymer to be substantially freed of solvent in theinitial upstream section(s) and to become at least highly softened if not molten in themidstream and/or downstream section(s). The temperature profile used will thus varysomewhat depending on the makeup of the brominated anionic styrenic polymer beingprocessed.

[0061] The extrudate from the machine is passed through a die plate and the resultant continuous strands are allowed to drop onto a moving porous conveyor belt. 26 WO 2008/011477 PCT/US2007/073805 [0062] The contents of the belt and any former contents of the conveyor belt that may beemerging from the end of the conveyor belt are caused to drop into a classifier whichseparates the pellets and the fines from each other. Such droppage onto the classifier may alsocause some breakage to occur. The classifier can include, for example, an essentiallyhorizontally disposed mesh which is caused to vibrate back and forth longitudinally. Aparticularly suitable machine of this type is a Vibratory Classifier such as is available fromThe Witte Company, Inc, [0063] In a typical operation, the conveyor belt used is about 14 feet in length and isoperated at a speed in the range of about 100 to about 200 ft/min. The forced air and thewater used in the misting of the strands are typically at ambient room temperatures, but canbe heated if desired so as to reduce heat shock. The distance of the drop from the end of theconveyor belt to the screen of the classifier is typically in the range of about 18 to about 36inches.

[0064] In any of the properly conducted pelletizing processes of this invention using as thefeed to the devolatilization extruder a 50 wt% solution in bromochloromethane of brominatedanionic polystyrene, which brominated anionic polystyrene has a bromine content of at least50 wt% (preferably at least 60 wt%, and more preferably at least 67 wt%), it should bepossible to produce a product in which no more than about 5 wt%, preferably no more thanabout 3 wt%, and more preferably no more than about 1 wt% are fines or dusts that passthrough a standard U.S. No. 40 sieve. Thus, the pelletizing processes of this invention arehighly efficient; only small amounts of such fines are collected and preferably recycled in theoverall pelletizing operation.

[0065] Turning now to the Drawings, Fig. 1 depicts in block diagram format many of thesteps included in preferred process operations of this invention from which some or all of thedepicted steps may be used, depending upon the particular embodiment being utilized. Thesequence shown in Fig. 1 is typical, but suitable changes or additions can he made in thesequence such as insertion of separation steps, washing steps, or other like processing steps,not shown in Fig. 1. Thus, as long as devolatilization as at IX is conducted, an embodimentof this invention can start at any stage at or above IX, and stages above and/or below IX canbe inserted or omitted from the sequence depicted as long as a result pursuant to this inventionis achieved. As seen from Fig. 1, some embodiments of this invention start with I,bromination of styrenic polymer to form brominated styrenic polymer. Optionally hydrogenhalide (HBr or HCl) co-product may be removed from the reaction mixture. Alternatively thehydrogen halide co-product is kept in the reaction mixture to serve as a co-solvent. When thedesired extent of bromination has been achieved, the aromatic bromination reaction isterminated as at II, by addition of a suitable quantity of water to deactivate the catalyst. Whenthe hydrogen halide co-product has been kept with the reaction mixture, this catalyst 27 WO 2008/011477 PCT/US20O7/073805 deactivation is accomplished in a closed system operating under pressure to retain thehydrogen halide co-product with the reaction mixture when such technique is being usedinstead of venting and collecting this co-product earlier in the operation. In either case thereaction mixture with all or only a portion of the co-product HX is quenched, with water orwater containing other components such sodium sulfite as at HI. The hydrogen halide canbe recovered as hydrobromic acid or hydrochloric acid. Use of the sequence of II and III ispreferred. However, it is possible to eliminate II and conduct quenching as at III by pumpingthe reaction mixture into water or aqueous sodium sulfite. The aqueous and organic phasesare separated as at IV. The organic phase containing the brominated styrenic polymer canthen be washed with aqueous base such as aqueous sodium hydroxide solution as at V, toremove residual HBr and/or HCI.

[00661 In some preferred embodiments, it is desirable to subject the organic phase whichtypically consists essentially of a solution of up to about 40 wt% of brominated styrenicpolymer in organic solvent plus some residual water and salts, to coalescing filtration as atVI, to remove entrained water and dissolved salts from the organic phase. In someembodiments of this invention the processing of such organic phase is continued. In otherembodiments an organic phase typically consisting essentially of a solution of up to about 40wt% of brominated styrenic polymer in organic solvent and which may or may not have beensubjected to coalescing filtration, is used as a starting material for devolatilizing extrusion.In any such case, such an organic phase is concentrated as at VII, to form an admixture ofextrudable viscosity typically by distillation or flash distillation to remove a suitable portionof the organic solvent from the organic phase mixture. Preferably, solvent removed from themixture is recovered for reuse. In embodiments where an initial organic phase mixture is ofa brominated styrenic polymer of sufficiently high molecular weight as to yield a mixturewhich already is of extrudable viscosity, such concentration step of VII may be eliminated.Before processing the admixture of extrudable viscosity to effect devolatilization in adevolatilization extruder, it is desirable to preheat the admixture as at VIII. Such preheatingcan be conducted in a devolatilization extruder if equipped with preheating section, or in aseparate preheater vessel or zone if the devolatilization extruder is not equipped with apreheating section. Such preheating typically facilitates operation of the devolatilizationextruder, and is thus preferably utilized in the process.

[0067] In some embodiments of this invention the processing of such admixture ofextrudable viscosity is continued after conducting V, VI, or VII, whereas in otherembodiments such an admixture is used as a stating material. In any such case, an admixtureof extrudable viscosity, preferably after at least formed via concentration as at VII, isprocessed in a devolatilization extruder as at IX, to form a melt or flow of brominated styrenicpolymer and a separate vapor phase of organic solvent which preferably is recovered and 28 WO 2008/011477 PCT/US2007/073805 condensed for reuse as a solvent. Then the melt or flow is subjected to product recovery asat X~A or subjected to pelletizing as at X-B, or a portion of the melt is subjected to productrecovery as at X-A and another portion (typically all the rest of the melt or flow) is subj ectedto pelletizing as at X-B. Product recovery as at X-A can be as simple as collecting orrecovering melt or flow of brominated styrenic polymer from a devolatilization extruder.Figs. 2 and 3 illustrate a preferred way of carrying out the pelletizing operation.

[0068] Referring now to a preferred system involving pellet formation as schematicallydepicted in Figs, 2 (top view) and 3 (side view) wherein like numerals depict like parts, anadmixture of extrudable viscosity comprising brominated styrenic polymer, preferablybrominated anionic styrenic polymer, typically containing at least 50 wt% of bromine and asolvent, preferably a halogenated solvent, is fed from line 10 into inlet 12 of devolatilizationextruder 11 equipped with a preheater section (not shown). If the devolatilization extruder11 is not so equipped, the admixture is preferably fed to a separate preheater or preheater zone(not shown). In either such case the admixture is preferably preheated to a temperature in therange of about 165 to about 185 °C, and then processed in the devolatilization extruder so thatthe admixture is devolatilized, e.g., substantially freed of halogenated solvent and othervolatile substances that may be present, by application of sufficient heat and reduced pressure.Depending on the design of devolatilization extruder 11, most of the volatiles may bedischarged through a vent located to the rear of inlet 12. In any event, further downstreamin devolatilization extruder 11, the contents of the extruder achieve a flowable semi-solid stateas a polymer melt and/or a polymer flow of the brominated styrenic polymer and the melt orflow is discharged through die 18 whereby strands, typically continuous strands, of thepolymer are extruded from the die onto moving conveyor belt 20. In the system depicted, belt20 is upwardly inclined such that the remote end of the upper portion of the belt is typicallyabout 18 to about 36 inches above vibratory classifier 30. Spray system denoted generallyas 33 forms and dispenses a mist or spray of water onto the hot polymer strands on the upperportion of belt 20 which is traveling in the direction shown by arrow 35. The cooled strandsare then carried by belt 20 under air knives 37,37 which cut or break at least a portion of thestrands into pellets. At the underside of belt 20 in proximity to the location of air knives37,37 are vacuum inlets 39,39 of a conventional vacuum manifold system (not shown) whichdraws off residual water and fines from the underside of belt 20. The resultant pellets aredischarged at the upper outer end of belt 20 and fall under the influence of gravity onto theoperative upper surface of classifier 30 which can be a vibratory classifier. The impact of thefall can result in formation of addition pellets through breakage of larger pieces falling frombelt 20. Thus the pellets in the system depicted in Figs. 2 and 3 are mainly formed in theregion extending from the air knives 37,37 to and including classifier 30. Fines are separatedby and collected within classifier 30 which continuously transfers the pellets remaining after 29 WO 2008/011477 PCT/US20O7/073805 the separation onto transfer device 40 such as a segmented conveyor or bucket elevatordisposed to receive and convey the pellets forwardly and upwardly to an elevation suitablefor feeding the pellets to a suitable heavy duty packaging container 50, such as a Supersackor Gaylord container. If any fines are formed in such packaging step due to pellet breakage,it can be minimized or eliminated by reduction in the height of the fall from the transferdevice to the packaging container.

[0069] Fig, 4 of the drawings illustrates a preferred sequence of steps utilizing an overallprocess of this invention in which granules or pastilles of unadulterated brominated styrenicpolymers are produced. The above description relative to Fig. 1 as regards forming pelletsapplies equally well to Fig. 4, except for the last step. In Fig. 4, the last step involves forminggranules or pastilles using appropriate procedures and apparatus.

[0070] The combination of devolatilization followed by forming granules or pastilles usingapparatus such as is available in the open market provides a number of important technicaland economic advantages. In the first place, use of this combination of operations eliminatesthe need for a very large scale (e.g., 16,000 gallon) precipitation vessel in which thebrominated anionic styrenic polymer is precipitated from the reaction mass in hot water. Alsoeliminated are other associated items such as a centrifuge for recovering the solids from theliquid phase and a large scale dryer for drying the product. Elimination of such large scaleequipment also enables the overall process to be operated in a smaller space. In addition,operating costs including heat energy requirements are significantly reduced, substantialportions of the solvent used in the process (i.e., that coming from the devolatilizationextruder) can be recycled without drying, and the overall process has the additional capabilityof purging volatile impurities or coproducts from the heavy ends formed in the process. Forexample, during continuous or repetitive batch operations, a small portion of the solvent,preferably bromochloromethane, becomes converted into dibromomethane and it is highlyadvantageous to purge this material at least periodically from the solvent being recycled inthe process.

[0071] Illustrative of commercially-available apparatus that can be adapted for use informing the granules or pastilles is the system available from Kaiser Steel Belt SystemsGmbH designated as Pastillation System Rollomat®. Equipment of this type and its operationis not only described in promotional material available from Kaiser Steel Belt Systems GmbH,but also in U.S. Pat. Nos, 5,198,233 and 5,278,132.

ANALYTICAL PROCEDURES

[0072] If deemed necessary or desirable, any reliable analytical procedure such as reported in the literature can be employed in determining such analysis or properties. In any doubtful or disputed case, the following procedures are recommended: 30 WO 2008/011477 PCT/US2007/073805 [0073] 1) Bromine Content - Since brominated styrenic polymers have good, or at leastsatisfactory, solubility in solvents such as tetrahydrofuran (THF), the determination of thetotal bromine content for a brominated styrenic polymer is easily accomplished by usingconventional X-Ray Fluorescence techniques. The sample analyzed is a dilute sample, say0.1± 0.05 g brominated polystyrene in 60 mL THF. Tbe XRF spectrometer can be a PhillipsPW1480 Spectrometer. A standardized solution of bromobenzene in THF is used as thecalibration standard.

[0074] 2) Crush Strength - The Crush Strength Test utilizes a Sintech 1/S compressionapparatus (MTS Systems Corporation, Edenprairie, Minnesota) equipped with Testworkssoftware, which software is installed in the 1/S compression apparatus as supplied by MTSSystems Corporation. The 1/S compression apparatus includes a horizontal load cellinterfaced with a computer, a digital micrometer also interfaced with the computer, and avertical screw-driven piston that is disposed above the load cell and adapted to apply adownward force perpendicular to the load cell. The procedure for measuring crush strengthinvolves measuring the length of the pellet with the micrometer to provide a digitized inputto the computer. Next the pellet is placed on its end on the load cell with the piston in contactwith the upper edge of the pellet. Then the apparatus is activated whereby the pistoncommences applying a progressively increasing downward force to the pellet. At the sametime, the load cell continuously measures the downward force being applied to the pellet, andthe input of such measurements is transmitted to the computer. When the force being appliedreaches the point where the amount of force suddenly decreases to 10% of the immediatelypreceding force, the pellet has reached the breaking point, and the application of the force isimmediately terminated by the software program. From the inputs to the computer, twovalues are provided, namely the pounds of force at the breaking point of the pellet, and thepounds of force per inch of length of the pellet at the breaking point. Thus the greater theforce applied, the greater the crush strength. In the test 13 pellets are selected at random andused in the test. The only qualification is that the selected pellets should have flat endportions so as to rest flatly on, and stand vertically in, the load cell and with the flat upper endfitting flatly against the lower surface of the piston.

[0075] 3) Molecular Weight and Polydispersity - Molecular weight values of styrenic

polymers are obtained by GPC using a Waters model 510 HPLC pump and, as detectors, aWaters Refractive Index Detector, Model 410 and a Precision Detector Light ScatteringDetector, Model PD20OO, or equivalent equipment. The columns are Waters, μStyragel,50θΑ, 10,O00Aand 100,000 A. The autosampler is a Shimadzu, Model Sil 9A. Apolystyrenestandard (Mw = 185,000) is routinely used to verify the accuracy of the light scattering data.The solvent used is tetrahydrofuran, HPLC grade. The test procedure used entails dissolving0.015-0.020 g of sample in 10 mL of THF. An aliquot of this solution is filtered and 50 pL 31 WO 2008/011477 PCT/US2007/073805 is injected on the columns. The separation is analyzed using software provided by Precision

Detectors for the PD 2000 Light Scattering Detector. The instrument provides results in terms of weight average molecular weight and also in terms of number average molecular weight.

Thus, to obtain a value for polydispersity, the value for weight average molecular weight is divided by the value for number average molecular weight.

[0076] 4) To determine the amount of organic solvent retained in a brominated styrenicpolymer sample, proton NMR spectra are acquired using a Broker DPX 400 MHZ instrumentfor solutions of about 20 wt% brominated styrenic polymer in 5/2 volume ratio carbondisulfide/dichloromethane-d2 (one 30 degree pulse experiment, 8 scans and 15 second pulsedelay). The integrals of the brominated styrenic polymer are obtained along with theintegral(s) for the organic solvent component. Using the appropriate molecular weight valueswith such integrai(s), the amount of the organic solvent in the polymer is calculated.

CONTINUOUS PROCESSES

[0077] While the processes of this invention can be conducted as batch processes whereina given quantity of feed materials are processed and then the operation is shut down, it ispreferred to conduct the processes of this invention on a continuous basis where onlyperiodically is the operation shut down e.g., for equipment repair or maintenance. Preferredcontinuous processes of this invention produce either highly pure melts or flows ofbrominated free radical styrenic polymer or highly pure pellets of brominated free radicalstyrenic polymer. Especially preferred continuous processes of this invention produce eitherhighly pure melts or flows of brominated anionic styrenic polymer or highly pure pellets ofbrominated anionic styrenic polymer. Common to these continuous processes are some or allof the operations described in block diagram form in Fig. 1.

PELLETS OF THE INVENTION

[0078] Pursuant to this invention, pelletized brominated styrenic polymers are producedhaving little, if any, fine particles or dusts.

[0079] Novel pellets of this invention are composed of unadulterated brominated anionicstyrenic polymer, preferably unadulterated brominated anionic polystyrene, having thefollowing characteristics: A) a bromine content of at least about 50 wt%, preferably at least about 60 wt%, morepreferably at least about 64 wt%, and still more preferably in the range of about 67 toabout 71 wt%; B) an average crush strength in the Crush Strength Test of at least about 28 pounds persquare inch, and preferably of at least about 32 pounds per square inch; C) a particle size range in which at least about 70 wt%, and preferably at least about 75wt%, of the pellets are retained on a standard US No. 40 sieve and no more than about 32 WO 2008/011477 PCT/US20O7/073805 30 wt% and preferably no more than about 25 wt%, are retained on a standard US No. 5 sieve.

More preferably at least about 80 wi%, still more preferably at least about 85 wt%, and evenmore preferably at least about 90 wt%. of the pellets are retained on a standard U.S. No. 40sieve and, respectively, more preferably no more than about 20 wt%, still more preferably nomore than about 15 wt%, and even more preferably no more than about 10 wt%, are retainedon a standard U.S. No. 5 sieve.

GRANULES OR PASTILLES PRODUCIBLE BY USE OF THIS INVENTION

[0080] To simulate a process of this invention, pastilles were produced and subjected totests to determine their crush strength. Using a Rollormat pastillation system, (Kaiser SteelBelt Systems) brominated anionic polystyrene having a bromine content of approximately68% and a melt flow index at 220°C and 2.16 kilogram load of 4 to 35 grams per 10 minuteswas subjected to pastillation. Substantially uniform pastilles were formed and solidified onthe water-cooled traveling steel belt. A sample of these pastilles was collected fordetermination of physical properties. In particular, tests were conducted to measure both theheight of 13 randomly selected pastilles produced in the process just described and the crushstrength of the selected pastilles. The apparatus used in these tests was a Sintech 1/Sinstrument. The procedure used involved the following: 1) randomly selecting 13 pastilles from the sample undergoing the test and measuring theheight of each pastille from its flat base to the peak of its dome; 2) placing a pastille on the stationary unpadded steel plate of the instrument such that theflat surface of the pastille rests on the steel plate with the peak of the dome of thepastille directly below the moveable crosshead of the instrument upon which a 50pound load cell is attached. Attached to the load cell is a cylindrical shaft which is flaton its lower end that will come in direct contact with the peak of the dome of thepastille; 3) lowering the crosshead to within 0.002 inch of the peak of the dome; 4) lowering the crosshead by the motorized screw drive of the instrument at the rate of0.2 inch per minute until the pastille is crushed at which point the maximum load isrecorded, and the crush strength in pounds per inch is calculated.

The above procedure is repeated individually with each of the 13 randomly selected pastillesfrom the sample of pastilles undergoing the test. The crush strength is determined in each ofthe respective 13 cases by dividing the maximum load (in pounds) by the height (in thefraction of an inch) of the respective pastille subjected to the test.

[0081] Table 1 summarizes the results of the 13 individual tests, the average values achieved, the standard deviations of the values achieved, and the minimum and maximum values achieved in the test. In Table 1, the granules or pastilles are referred to simply as 33 WO 2008/011477 PCT/US2OO7/O73805 pastilles for economy of space. The abbreviations used and their full meaning are as follows: in. stands for inch; lbs stands for pounds force; Avg. stands for average; Std. Dev. stands for standard deviation; Min. stands for minimum; and Max. stands for maximum. TABLE 1

Pastille No. Pastille Height, inches Peak Load Applied,pounds Energy to Crush,lbs/in. 1 0,207 12.97 62.66 2 0,213 7.56 35.49 3 0.219 14.52 66.30 4 0.208 10.23 49.18 5 0.213 9.26 43.47 6 0,199 8.00 40.20 7 0.224 7.34 32.77 8 0.207 14.67 70.87 9 0.200 10,08 50.40 10 0.214 10.23 47.80 11 0.204 10.00 49.02 12 0.219 7.85 35.84 13 0,220 7.19 32.68 Average 0.211 9.99 47.44 Std. Dev. 0.008 2.60 12.68 Min. 0.199 7.19 32.7 Max. 0.224 14.67 70.9 USE OF THE PELLETS OR THE GRANULES OR PASTILLES AS FLAME RETARDANTS[0082] The pellets of this invention and the granules/pastilles produced pursuant to thisinvention can be used as flame retardants in a wide variety of thermoplastic polymers.Among such polymers are thermoplastic polyesters, such as polyethylene terephthalate,polybutylene terephthalate, polytrimethylene terephthalate, poly cyclohexylene terephthalate,etc.; thermoplastic polyamides, such as nylon 6, nylon 6,6, nylon 6,12, etc.; polycarbonates;polyphenylene oxides, such as poly(2,6-dimethylphenylene oxide); polysulphones;polystyrene or other styrenic homopolymers; copolymers of two or more styrenic monomers 34 WO 2008/011477 PCT/US2007/073805 such as copolymers of styrene, vinyltoluene, ethylstyrene, tert-butylstyrene, a-methylstyrene,vinylnaphthalene, etc/ rubber-modified vinylaromatic homopolymers or copolymers (c.g.,high imp act polystyrene); acrylate or methacrylate polymers such as ethylene-methylacrylate,ethylene-ethylacrylate, ethylene-hutylacrylate, poly(methylmethacrylate), etc./ ethylene-vinylacetate copolymers; acrylonitrile-based copolymers and terpolymers such asacrylonitrile-butadiene-styrene (ABS) and styrene-acrylonitrile (SAN), etc/ polyolefins, suchas polyethylene, polypropylene, poly-(l-butene), and copolymers of ethylene with one ormore higher vinyl olefins such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene; and blends, alloys, or composites of different polymers such as for example a blendof poly(2,6-dimethylphenylene oxide) and polystyrene, a blend of polycarbonate andpolystyrene, and similar blends. Additional polymers that can he flame retarded by usetherewith of pelletized flame retardant additives of this invention include rubbery blockcopolymers such as styrene-ethylene-ethylene-styrene, styrene-ethylene-propylene-styrene,styrene-ethylene-butylene-styrene, etc/ polyurethanes; epoxy resins; phenolic resins;elastomers such as natural rubber, butyl rubber, GRS, GRN, EPDM, etc; polysiloxanes; andthe like. Further, the polymer may be, where appropriate, cross-linked by chemical means orby radiation. A large number of flame retardant-free polymers suitable for use in the practiceof this invention can be obtained from a number of commercial sources.

[0083] A preferred group of substrate polymers that can be effectively flame retarded by useof the pellets of this invention are polyesters. Thermoplastic polyesters, often referred to aspolyalkylene terephthalates, are reaction products of aromatic dicarboxylic acid or reactivederivatives thereof, such as methyl esters or anhydrides, and aliphatic, cycloaliphatic, oraraliphatic diols, and mixtures of such reaction products. Examples of such thermoplasticpolyesters include polyethylene terephthalate, polypropylene terephthalate, polybutyleneterephthalate, polycyclohexylene dimethylene terephthalate, and related copolyesters andblends, including blends of one or more thermoplastic polyesters with one or more otherthermoplastic polymers such as polycarbonates, and especially aromatic polycarbonates.[0084] Preferred thermoplastic polyesters contain at least 80% by weight and preferably atleast 90% by weight, based on the dicarboxylic acid component, of terephthalic acid and atleast 80% by weight and preferably at least 90% by weight, based on the diol component, ofethylene glycol and/or 1,4-hutanediol units.

[0085] in addition to terephthalic acid units, the preferred thermoplastic polyesters maycontain up to 20 mole % and preferably up to 10 mole % of units of other aromatic orcycloaliphatic Cs.]4 dicarboxylic acids or aliphatic dicarboxylic acids, such as, forexample, units of phthalic acid, isophthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-diphenyl dicarboxylic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, orcyclohexane diacetic acid. 35 WO 2008/011477 PCT/US2007/073805 [0086] In addition to ethylene glycol and 1,4-butanediol units, the preferred thermoplasticpolyesters may contain up to 20 mole % and preferably up to 10 mole % of other aliphatic C3 .i2 diols or cycloaliphatic C6„i2 diols, such as, for example, units of 1,3-propanediol, 2-ethylpropane-1,3-diol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexane-dimethanol, 3-ethylpentane-2,4-diol, 2-methylpentane-2,4-diol, 2,2,3-trimethylpentane-l,3-diol, 2-ethylhexane-l,3-diol, 2,2-diethylpropane-l,3-diol, 2,5-hexanediol,2,2-his(4-hydroxy-cyclohexyl)prop ane, 2,4-dihydroxy-1,1,3,3 -tetramethylcyclobutane, 2,2-bis[4-(2-hydroxy-ethoxy)phenyl]prop ane, or 2,2-bis- [4-hydroxypropoxy)phenyl]propane.

[0087] Polyalkylene terephthalates may be branched by incorporation of relatively smallquantities of trihydric or tetrahydric alcohols or tribasic or tetrabasic carboxylic acids. In thisconnection see, for example, U.S. Pat. No. 3,692,744. Examples of preferred branchingagents are trimesic acid, trimellitic acid, trimethylol ethane and propane and pentaerythritol.[0088] Particularly preferred thermoplastic polyesters are those produced solely fromterephthalic acid or a reactive derivative thereof such as a dialkyl ester, and ethylene glycoland/or 1,4-butane diol, and mixtures of these polyalkylene terephthalates. Preferredpolyalkylene terephthalate mixtures contain 1 to 50% by weight of polyethylene terephthalateand 99 to 50 wt% of polybutylene terephthalate. Particularly preferred mixtures contain 1 to30 wt% of polyethylene terephthalate and 99 to 70% by weight of polybutylene terephthalate.[0089] The polyalkylene terephthalates preferably used generally have an intrinsic viscosityof 0.4 to 1.5 dl/g, preferably 0.5 to 1.3 dl/g and more preferably 0.55 to 1.2 dl/g, as measuredin phenol/o-dichlorobenzene (1:1 parts by weight) at 25 ° C using an Ubbelohde viscosimeter.Polyethylene terephthalate and polybutylene terephthalate of these intrinsic viscosity ranges,and mixtures thereof, are most preferred. As is well known, polyethylene terephthalateengineering resin producers compound their products from either virgin PET (typically 0.55-0.70 IV) or reclaimed PET from industrial scrap, polyester film scrap, bottles and, rarelypolyester fiber scrap.

[0090] Additional thermoplastic polyesters which may be utilized in the practice of thisinvention include, for example, polyetheresters, polyester-polycarbonate blends or alloys,polyester-AB S blends or alloys, polyester-MBS blends or alloys, and impact-modifiedthermoplastic polyesters.

[0091] Polyalkylene terephthalates may he produced by known methods. See, for example,Encyclopedia of Polymer Science and Technology, Vol. 11, pages 62-128, John Wiley &Sons, Inc., copyright 1969; and Kirk-Othmer, Encyclopedia of Chemical Technology, 4th Ed.,Vol. 19, pages 609-653, John Wiley & Sons, Inc., copyright 1996.

[0092] Another group of preferred thermoplastic polymers which can be effectively flame retarded by use of the pellets of this invention are polyamides, which are sometimes referred to as nylon polymers. Such polyamide substrate polymer can be any amorphous and/or partly 36 WO 2008/011477 PCT/US2007/073805 crystalline, predominately aliphatic/cycloaliphatic or partially aromatic thermoplasticpolyamide. Typically such materials are produced by polycondensation and/orpolymerization processes from diamines which are predominately or entirely aliphatic orcycloaliphatic in structure, or which are partially or entirely aromatic in structure, andcarboxylic acids or lactams which are predominantly or entirely aliphatic or cycloaliphaticin structure, or which are partially or entirely aromatic in structure. Typical amines used informing polyamides include such diamines as hexamethylenediamine, tetramethylenediamine, 2,2,4- and 2,4,4-trimethyl-hexamethylenediamine, diaminodicyclohexylmethane (isomers),diamino di cyclo hexylpropane (isomers) and isophoronediamine (isomers), andxylylenediamine. Also used as source materials are aminocarboxylic acids such as ε-aminocaproic acid, or ω-ami no carboxy lie acids such as ra-aminolauric acid and ra-aminoundecanoic acid. Typically, the carboxylic acid used are aliphatic or mixed aliphatic-aromatic dicarboxylic acids having less than 50% by weight aromatic constituents such asadipic acid, 2,2,4- and 2,4,4-trimethyladipic acid, azelaic acid, sebacic acid,decanedicarboxylic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid,hexahydroterephthalic acid, isophthalic acid and terephthalic acid.

[0093] Copolyamides from the majority of the known monomers can also be used.

[0094] Illustrative polyamides which may be used in the practice of this invention are suchpolyamides as nylon 6, nylon 6,6, nylon 6,9, nylon 6,10, nylon 6,12, nylon 11, nylon 12,nylon 12,12, nylon 6/6,6 copolymer, and high temperature nylons such as nylon 4,6, andpartially aromatic nylons (e.g., Ixef polyarylamide PA MXD6 from Solvay, Zytel HTN fromDuPont, and Amodel polyarylamide from Solvay), Other polyamides which may be usedinclude Arlen modified polyamide 6T from Mitsui Chemicals, Inc., Genestar PA9T polyamideresin from Kuraray Company, Stanyl polyamide 46 from DSM, Vydyne polyamide 6/66copolymers from Monsanto, polyamide 612 (Vestamid D from Creanova), and similarpolyamides. Of the various nylon polymers, nylon 6 and nylon 6,6 are the preferred substratepolymers.

[0095] This invention is also applicable to thermoplastic blends or alloys of one or morepolyamides such as, for example, polyamide-polyolefin blends or alloys, polyamide-ionomerblends or alloys, polyamide-ABS blends or alloys, polyamide-EPDM blends or alloys,polyamide-polyphenylene oxide blends or alloys, or impact-modified polyamides.

[0096] Methods for producing polyamide polymers are known and described in theliterature. See, for example, Encyclopedia of Polymer Science and Technology, Vol. 10,pages 460-482, John Wiley & Sons, Inc., copyright 1969; and Kirk-Othmer, Encyclopedia ofChemical Technology, 4th Ed., Vol. 19, pages 559-584, John Wiley & Sons, Inc., copyright1996. 37 WO 2008/011477 PCT/US2007/073805 [0097] The following example illustrates the practice and advantages of one embodiment this invention. This example is not intended to place limitations upon the generic scope of this invention.

EXAMPLE

[0098] The devolatilization extruder used in this operation was a Werner & Pfleiderer ZSK-30 30mm co-rotating twinscrew extruder. The machine had a nine-barrel configuration withan L/D ratio of 27/1. A vent was located on barrel 4, and a vent for application of a 30-inchvacuum on barrel 8 was provided. A vacuum knockdown trap was provided to condensevolatiles exiting from the vent in barrel 4. The machine was operated with the followingtemperature profile: Feed throat with cooling water ON, Zone 1 at 140 °C, Zone 2 at 180 ° C,

Zone 3 at 220 °C, Zone 4 at 240°C. The die at the outlet was held at 230°C. The screwdesign provided a gentle kneading block section in barrels 5 and 6. Operating conditions were125 rpm and 30% torque, with a melt temperature of 243 °C and a feed rate of an 83%solution of brominated anionic polystyrene (formed from SAYTEX HP 3010, AlbemarleCorporation) in bromochloromethane (BCM) of 8kg/hr. Two strands were extruded onto a 5-foot long takeoff belt conveyor, and gravity fed to a open drum at the end of the belt.Samples were taken from the open drum. Because of a limited material quantity ofbrominated anionic polystyrene available for this operation, the machine was operated forabout 8-10 minutes. The material ran smoothly during the operation. About 20-30 mL ofBCM solvent was condensed in the vacuum knockdown trap. Dry ice and isopropyl alcoholwere used to cool the vacuum trap, and this was adequate to condense the BCM even at the30-inch Hg vacuum used. The devolatilized pellets of unadulterated brominated anionicpolystyrene produced had a nice appearance and had sufficient hardness to be placed intoseveral storage containers, two of which were transported without noticeable pellet breakage.[0099] The overall system utilized in the Example is schematically depicted tn Figs. 2 and3. In such system, the following equipment was used: a) The devolatilization extruder system 11 equipped and fitted, all as describedin the Example. b) Die 18 was a 2-hole die with holes of 4 mm diameter. c) Conveyor belt 20 was a Scheer-Bay conveyor having a length of 14 feet (ca. 4.3 meters), a width of 15 inches (ca. 38.1 cm), and 3-inch (ca. 7.6-centimeter) diameterrollers. The mesh belt was upwardly inclined at an angle of about 12 °. d) Classifier 30 was a Witte model no 200 Classifier.

The vertical distance between the drop from the end of belt 20 to the top of classifier 30 was about 24 inches (ca. 61 cm), and the vertical distance between the end of transfer device 40 38 WO 2008/011477 PCT/US2007/073805 and the bottom of container 50 when empty was about 60 inches (ca. 152 cm). The conveyortraveled at a rate of 150 to 175 fi/min (ca. 45.7 to ca. 53.3 meters/minute. The water mist wasfed at a rate of about one gallon per minute (ca. 3.79 liters/minute). The air knives wereoperated at a pressure of 10-25 psig and were disposed at about 5 inches (ca. 12.7 cm) abovethe surface of the conveyor belt. The vacuum applied beneath the conveyor belt was at about2200 cubic feet per minute (ca. 62.3 cubic meters per minute) and the vacuum was applieddirectly to the proximate surface of the conveyor belt by two vacuum applicators disposedtransverse to the belt with the mouth of each applicator having an area of 45 square inches (ca. 114.3 square centimeters).

[0100] To illustrate the improved strength prop erties achievable in pellets of this invention,there are shown in Table 2 crush strength data of pellets produced by devolatilizationextrusion of a 60 wt% solution made from brominated anionic polystyrene powderSAYTEX HP 3010, Albemarle Corporation) dissolved in bromochloromethane solvent(Pellets of This Invention) and of pellets produced not by devolatilization extrusion of thesolution, but instead by extrusion of brominated anionic polystyrene powder (SAYTEX HP3010, Albemarle Corporation) as described in commonly-owned published PCT patentapplication WO 2005/118245 (Pellets Not of This Invention), pellets which are of goodquality. TABLE 2

Pellets of This Invention Pellets Not of This Invention Sample Length, inch Peak Load,lbs. Energy toCrush, lbs/in. Sample Length, inch Peak Load, lbs. Energy toCrush, lbs/in. 1 0.190 4.44 23.37 1 0.143 5.06 35.38 2 0.257 6.40 24.90 2 0.206 5.44 26.41 3 0.182 7.79 42.80 3 0.194 2.63 13.56 4 0.304 8,68 28.55 4 0.185 5.93 32.05 5 0.323 8.28 25.63 5 0.229 14.37 62.75 6 0.323 5.51 17.06 6 0.210 5.84 27.81 7 0.280 9.74 34.79 7 0.178 6.73 37.81 8 0.153 10.02 65.49 8 0.191 4.32 22.62 9 0.258 9.80 37.98 9 0.273 4.91 17.99 10 0.254 8.58 33.78 10 0.295 4.45 15,08 11 0.285 9.54 33.47 11 0.354 4.34 12.26 12 0.386 10.75 27.85 12 0.329 3.47 10.55 13 0,473 12.25 25.90 13 0.415 5.34 12.87 Average 0.282 8.60 32.43 Average 0.246 5.60 25.16 Std. Deviation 0.086 2.16 12.04 Std....... deviation 0.081 2.84 14.60 39 196429/2 [00101] Components referred to by chemical name or formula anywhere in the specification orclaims hereof, whether referred to in the singular or plural, are identified as they exist prior tocoming into contact with another substance referred to by chemical name or chemical type (e.g.,another component, a solvent, or etc.). It matters not what preliminary chemical changes, 5 transformations and/or reactions, if any, take place in the resulting mixture or solution as suchchanges, transformations, and/or reactions are the natural result of bringing the specifiedcomponents together under the conditions called for pursuant to this disclosure. Thus thecomponents are identified as ingredients to be brought together in connection with performing adesired operation or in forming a desired composition. Also, even though the claims hereinafter 10 may refer to substances, components and/or ingredients in the present tense ("comprises", "is",etc.), the reference is to the substance, component or ingredient as it existed at the time just beforeit was first contacted, blended or mixed with one or more other substances, components and/oringredients in accordance with the present disclosure. The fact that a substance, component oringredient may have lost its original identity through a chemical reaction or transformation during 15 the course of contacting, blending or mixing operations, if conducted in accordance with thisdisclosure and with ordinary skill of a chemist, is thus of no practical concern.

[00102] Except as may be expressly otherwise indicated, the article "a" or "an" if and as usedherein is not intended to limit, and should not be construed as limiting, a claim to a single elementto which the article refers. Rather, the article "a" or "an" if and as used herein is intended to cover 20 one or more such elements, unless the text expressly indicates otherwise. 40