Compositions with compatibilized silica, nitrile rubber, styrene butadiene rubber, elastomeric compounds, and/or recycled materials

TITLE: COMPOSITIONS WITH COMPATIBILIZED SILICA, NITRILE RUBBER, STYRENE BUTADIENE RUBBER, ELASTOMERIC COMPOUNDS, AND/OR

RECYCLED MATERIALS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority and benefit of: US Provisional Patent

Application Serial No. 61/292,910 filed on January 07, 2010 and US Patent Application Serial No. 12/984,267 filed on January 04, 2011, both entitled "PROCESS FOR MAKING COMPATIBILIZED SILICA AND NITRILE POLYMER COMPOSITIONS"; US Provisional Patent Application Serial No. 61/292,917 filed on January 07, 2010 and US Patent Application Serial No. 12/984,280 filed on January 04, 2011, both entitled "COMPATIBILIZED SILICA IN NITRILE RUBBER AND BLENDS OF NITRILE RUBBER AND STYRENE BUTADIENE RUBBER COMPOSITIONS"; and US Provisional Patent Application Serial No. 61/292,923 filed on January 07, 2010 and US Patent Application Serial No. 12/984,295 filed on January 04, 2011, both entitled "ELASTOMERIC COMPOUNDS CONTAFNING RECYCLED MATERIALS AND SILICA". These references are hereby incorporated in their entirety.

FIELD [0002] The present embodiments generally relate to a compatibilized silica and nitrile polymer blend in latex form, an acrylonitrile styrene butadiene terpolymer latex blend with compatibilized silica, a blend of acrylonitrile butadiene polymer and styrene butadiene polymer latex blend with compatibilized silica, polymeric compositions that are resistant to chemical and biological invasion or hazards, and a recycled elastomeric composition including rubber crumb, compatibilized silica, and carbon black.

BACKGROUND

A need exists to provide a simple and less expensive technique for the uniform incorporation of silica and other reinforcing agents, such as carbon blacks, into polymers at the latex stage that does not require the use of complex processing aids and does not cause premature coagulation of the latex, in which the silica can be substantially uniformly dispersed and compatible with the polymer matrix during processing.

[0004] A need exists for a wet process for treating precipitated or fumed silica with a coupling agent, whereby the silica becomes compatible with a polymer phase of a polymer latex.

[0005] A need exists to provide a polymeric composition that has uniform filler dispersion, is easy to make, contains UV stabilizers, has a high density, is lightweight, and can resist chemical warfare compositions for use in resisting biological warfare to protect users.

[0006] A need exists for a recycled elastomeric compound that saves energy during production, lowers production cost, reduces transportation costs by not using raw hydrocarbons that typically come from offshore deep sea wells and are expensive, and has "green" characteristics, such as a rubber that is recaptured and recycled, reducing the amount of rubber in landfills.

[0007] The present embodiments meet these needs.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The detailed description will be better understood in conjunction with the accompanying drawings as follows:

[0009] Figure 1 is a diagram of an embodiment of a process.

[00010] Figure 2 is a diagram of an embodiment of a process for forming a blend of acrylonitrile and styrene butadiene terpolymer latex with compatibilized silica.

[00011] Figure 3 is a diagram of an embodiment of a process for forming a blend of acrylonitrile butadiene polymer and styrene butadiene polymer latex blend with compatibilized silica.

[00012] Figure 4 is a diagram of an embodiment of a process for forming a compatibilized silica in a latex blend of acrylonitrile butadiene polymer and styrene butadiene polymer. [00013] Figure 5 is a diagram of an embodiment of a process for forming a compatibilized silica and nitrile polymer blend in latex form.

[00014] The present embodiments are detailed below with reference to the listed Figures.

DETAILED DESCRIPTION OF THE EMBODIMENTS [00015] Before explaining the present processes, compositions, and articles in detail, it is to be understood that the processes, compositions, and articles are not limited to the particular embodiments and that the processes, compositions, and articles can be practiced or carried out in various ways.

[00016] One or more embodiments relate to an elastomeric polymeric composition with crumb rubber and silica formed using a continuous flow, a zero to low pressure, ambient to slightly above ambient temperature, emulsion polymerization with an activator, a free radical initiator, water, and a terminating agent, and to articles made form the elastomeric polymeric composition.

[00017] The elastomeric polymeric composition with crumb rubber and silica can have from 18 percent to 93 percent by weight, based on the total weight of the composition, of a synthetic elastomeric polymer.

[00018] The synthetic elastomeric polymer can contain from 60 percent to 82 percent by weight of liquid 1,3 -butadiene monomer based on the total weight of the elastomeric polymeric composition.

[00019] The elastomeric polymeric composition with crumb rubber and silica can have from 18 percent to 40 percent by weight of a styrene monomer based on the total ght of the elastomeric polymeric composition.

The elastomeric polymeric composition with crumb rubber and silica can have from 5 percent to 80 percent by weight of a compatibilized silica based on the total weight of the elastomeric polymeric composition. The compatibilized silica can have at least 1 percent by weight of an organosilicon coupling agent bound to about 20 percent by weight of a surface of the compatibilized silica.

The elastomeric polymeric composition with crumb rubber and silica can have from 1 percent to 50 percent by weight, based on the total weight of the composition, of a recycled crumb rubber.

The elastomeric polymeric composition with crumb rubber and silica can have from 1 percent to 40 percent by weight, based on the total weight of the composition, of a carbon black, or from 1 percent to 10 percent by weight of a carbon black based on the total weight of the composition.

The elastomeric polymeric composition with crumb rubber and silica can have particles of reclaimed rubber therein. In one or more embodiments, at least 50 percent by volume of the crumb rubber particles can be smaller than a #10 mesh U.S. series sieve, or at least 50 percent by volume of the crumb rubber particles can be smaller than a #200 mesh U.S. series sieve. The elastomeric polymeric composition with crumb rubber and silica can include crumb rubber that can be 100 percent sourced from recycled tires. Particles of reclaimed rubber can be passed through the sieves before the crumb rubber is incorporated into the elastomeric polymeric composition or a rubber composition.

During the emulsion polymerization to make the elastomeric polymeric composition, the synthetic elastomeric polymer can be in the form of a latex or a dry particulate.

The elastomeric polymeric composition with crumb rubber and can include from 0.1 percent to 50 percent by weight of a filler based on the total weight of the composition. The filler used in the processes, compositions, and articles described herein can be ground pecan shells, cellulosic materials, silage, diatomaceous earth, ground peanut shells, talc, ground coal, ground bagasse, ash, perlite, clay, calcium carbonate, biomass, or combinations thereof.

The elastomeric polymeric composition with crumb rubber and silica can include from 1 percent to 40 percent by weight of an extender oil based on the total weight of the composition.

The extender oil used in the processes, compositions, and articles described herein can be a synthetic oil, an aromatic oil, a naphthenic oil, a hydrocarbon, a polycyclic aromatic hydrocarbon oil, or combinations thereof.

The elastomeric polymeric composition with crumb rubber and silica can include up to 25 percent by weight of a thermoplastic polymer, a thermoplastic elastomer, a thermoplastic vulcanizate, or any combination thereof based on the total weight of the composition.

The elastomeric polymeric composition with crumb rubber and silica can be a composition of cross linked polymers. The elastomeric polymeric composition with crumb rubber and silica can be used to make various types of articles.

The articles that can be made from the processes and compositions described herein can include: floor mats, tires, belts, rollers, footwear, wire and cable jacketing, roof edging, tubular hoses, marine impact bumpers, industrial belts, non-automotive tires, mining belts, bearings, conduits, gasket printer's rollers, o- rings, shoes, garden hoses, pipe, side bumpers used for the docking of boats, non- latex gloves, gas masks, pneumatic tires used on bikes, cars, or airplanes, or the like. [00032] One or more embodiments relate to a recycled elastomeric composition and to articles made from the recycled elastomeric composition.

[00033] The natural rubber used in the processes, compositions, and articles described herein can be any polyisoprene, such as a rubber. The synthetic elastomeric polymer used in the processes, compositions, and articles described herein can be a styrene butadiene rubber.

[00034] The synthetic elastomeric polymer can include from 60 percent to 82 percent by weight of liquid 1,3-butadiene, from 18 percent to 40 percent by weight of a styrene, from 5 percent to 80 percent by weight of a compatibilized silica having at least 1 percent by weight of a coupling agent bound to a surface of the compatibilized silica, from 1 percent to 50 percent by weight of a crumb rubber, and from 1 percent to 40 percent by weight of a carbon black. [00035] The synthetic elastomeric polymer can be prepared by polymerizing and/or copolymerizing conjugated diene monomers, such as butadiene, isoprene, chloroprene, pentadiene, and dimethylbutadiene. The synthetic elastomeric polymer can contain vinyl monomers and combinations of conjugated dienes with vinyl monomers. [00036] A pinane hydroperoxide can be used in the emulsion polymerization.

Suitable vinyl monomers usable in the processes, compositions, and articles described herein can include: styrenes, alpha-methylstyrenes, alkyl substituted styrenes, vinyl toluene, divinylbenzene, acrylonitrile, vinylchloride, methacrylonitrile, isobutylene, maleic anhydride, acrylic esters and acids, methylacrylic esters, vinyl ethers, and vinyl pyridines.

The synthetic elastomeric polymer can include styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), acrylonitrile-butadiene-styrene polymer (ABS), polybutadienes, polyvinylchloride (PVC), polystyrene, polyvinylacetate, butadiene-vinyl pyridine polymers, polyisoprenes, polychloroprene, neoprene, styrene-acrylonitrile copolymer (SAN), or blends of acrylonitrile-butadiene rubber with polyvinylchloride.

[00039] The resulting recycled elastomeric polymer can be made from blends, which can include up to 25 percent by weight of a thermoplastic polymer, thermoplastic elastomer, thermoplastic vulcanizates, or combinations thereof. The thermoplastic polymer can be a thermoplastic polyolefm blend. The thermoplastic elastomer can be styrene butadiene block copolymer. The thermoplastic vulcanizate can be cross-linked ethylene propylene diene material in a polypropylene matrix.

The silica can constitute from 5 percent to 80 percent by weight of the overall composition of the recycled elastomeric polymer.

[00041] The emulsion polymerization blending can be performed by using a banbury mixer mixing at a rate ranging from 800 pounds to 1200 pounds for a time period ranging from 90 seconds to 30 minutes.

[00042] In addition to blending the silica with the polymers already recited herein, the compatibilized silica can be blended with polyolefms, polyalpha.-olefms, polyesters, polyamides, polycarbonates, polyphenylene oxides, polyepoxides, polyacrylates, and copolymers of acrylates and vinyl monomers. [00043] The polyolefms can be homopolymers, copolymers, crosslinked copolymers, and other comonomer combinations prepared from straight chain, branched, or cyclic alpha-monoolefms, vinylidene olefins, and nonconjugated di- and triolefins, including 1,4-pentadienes, 1,4-hexadienes, 1,5-hexadienes, dicyclopentadienes, 1,5-cyclooctadienes, octatrienes, norbornadienes, alkylidene norbornenes, vinyl norbornenes, and the like.

[00044] Examples of such polymers include polyethylenes, polypropylenes, ethylene- propylene copolymers, ethylene-alpha-olefin-nonconjugated diene terpolymers (EPDMs), chlorinated polyethylenes, polybutylene, polybutenes, polynorbornenes, and poly alpha-olefm resins. [00045] In one or more embodiments, to make the compatibilized silica usable in the processes, compositions, and articles described herein, a silica can be treated with a coupling agent in an aqueous solution, forming a slurry for blending with the other components. The silica can be made of a number of commercially available amorphous silica, such as precipitated or fumed silica, that have finely divided particle sizes and high surface areas. The size of the silica particles can be varied within relatively wide ranges, such as from 7 nm to 60 nm, depending on the end use of the silica- filled or silica-reinforced polymer.

The finely divided silica can thus be formed into an aqueous slurry and treated with a coupling agent that can chemically bond to the silica surface. Coupling agents known in the art can be used for coupling hydrophilic filler materials, such as glass fibers or silica, to hydrophobic materials, such as natural and synthetic elastomeric polymers useful as rubbers or thermoplastic materials. At least 20 percent bonding can be accomplished with the coupling agent.

Organosilicon compounds, well known for bonding silica to natural and synthetic elastomeric polymers, can be used as the coupling agent. The organosilicon can be derived from an organic silane.

In embodiments, one to three organic groups can be attached directly to the silicon atom that is compatible with the natural or synthetic elastomeric polymer to which the silica is to be added.

The coupling agent can be chemically bond to the natural rubber, the synthetic elastomeric polymer, or combinations thereof during curing of the natural rubber or synthetic elastomeric polymer.

The coupling agent can have the capacity of chemically reacting with the surface of the silica to bond the coupling agent thereto. The coupling agent can be or can include bis(trialkoxysilylalkyl)polysulfide. The bis(trialkoxysilylalkyl)polysulfide can have from two to eight sulfur atoms in which the alkyl groups can be CI -CI 8 alkyl groups, and the alkoxy groups can be C1-C8 alkoxy groups.

The amount of the coupling agent employed can be varied within relatively wide limits depending on the amount of silica to be blended with the natural or synthetic elastomeric polymer, and depending on the molecular weight of the coupling agent. A range from 1 part to 25 parts of coupling agent per 100 parts by weight of silica can be used, such as from 1 part to 15 parts by weight of coupling agent per 100 parts by weight of silica. The amount of coupling agent used can be defined in terms of the actual weight percent of organosilicon residing on the silica surface. Much of the weight of the coupling agent can be lost during reaction with the silica surface and condensation with itself.

[00053] To achieve greater than 90 percent by weight silica incorporation into the emulsion polymerized polymer, the weight percent of organosilicon on the surface of the silica can range from 0.50 to 10.0. As such, a minimum of 0.5 to 5 grams of organosilicon from the silane can be bound to 100 grams of silica charged to the slurry.

[00054] For enhanced compatibility in dry mix, or for additional chemical reaction with the natural or synthetic elastomeric polymers, greater than 1 percent by weight of organosilicon residue per weight of silica can be bound on the surface of the silica. For example, 10 percent to 20 percent by weight organosilicon can be bound on the surface of the silica.

[00055] The synthetic elastomeric polymer can have or include from about 55 percent by weight to about 92 percent by weight of a butadiene, such as liquid 1,3-butadiene (CH2=CHCH=CH2). The synthetic elastomeric polymer can include from about 8 to about 45 percent by weight of a styrene. In embodiments, the synthetic elastomeric polymer can be in the form of a latex or a dry particulate.

[00056] "Latex", as the term is herein used, refers to a stable dispersion or emulsion of polymer micro-particles in a medium. Illustrative mediums can include water or other fluid. The latexes can be natural or synthetic.

[00057] In one embodiment, the elastomeric composition can include from about 5 percent by weight to about 80 percent by weight of compatibilized silica.

[00058] In embodiments, the compatibilized silica can have at least 1 percent by weight of a coupling agent bounded to the surface of the compatibilized silica. In embodiments, the amount of coupling agent can range from about 1 percent by weight to about 50 percent by weight of coupling agent.

The recycled elastomeric composition can include from about 1 percent by weight to about 50 percent by weight of a crumb rubber.

"Crumb rubber" as the term is herein used, refers to material derived by reducing scrap tire or other rubber into uniform granules with the inherently reinforcing materials, such as steel and fiber removed along with any other type of inert contaminants such as dust, glass, or rocks. The crumb rubber can include particles of reclaimed rubber. Reclaimed rubber can be recycled rubber, which can be derived from synthetic and/or natural rubbers or plastics. In embodiments, the crumb rubber can be made of 100 percent recycled tires. At least a portion of the particles of reclaimed rubber can be passed through mesh U.S. series sieves as described herein before the crumb rubber is incorporated into the rubber composition. For example, from 10 percent to 50 percent of the particles of reclaimed rubber can be passed through a #200 mesh or other mesh sieve.

Embodiments of the elastomeric composition can include from about 1 percent to about 40 percent by weight of a carbon black. The carbon black can be a material consisting essentially of elemental carbon in the form of near-spherical colloidal particles and coalesced particle aggregates of colloidal size, obtained by partial combustion of thermal decomposition of hydrocarbons. Two different types of carbon black can be used.

The elastomeric composition can include fillers, such as those described herein. Embodiments of the elastomeric composition can include from about 0.1 percent by weight to about 50 percent by weight of the filler.

The compositions, articles, and processes described herein can include "other materials", such as ultraviolet (UV) stabilizers, extender oils, antioxidants, or antioxidants. The composition can include "other materials" in amounts from about 0.1 percent to 3 percent by weight based on the total weight of the composition.

[00064] The ultraviolet (UV) stabilizer can be a hindered amine, a benzotriazole, a triazine, or combinations thereof. The antioxidant can be a phenolic antioxidant, a phosphite, a bis-phenol, an amine antioxidant, or combinations thereof. For example, the elastomeric composition can include from about 0.01 percent by weight to about 40 percent by weight of the extender oil. The extender oil can act as a plasticizer and allow for an enhanced processing.

[00065] Embodiments can include an article prepared from the rubber composition, such as articles described herein. [00066] One or more embodiments can include a polymer composition that can have from about 6 percent to 90 percent by weight of a compatibilized silica, at least 1 percent by weight of a coupling agent, at least 10 percent by weight of a styrene butadiene polymer, and at least 10 percent by weight of an acrylonitrile butadiene polymer, and to articles made therefrom. [00067] The polymer composition, also referred to herein as polymer blend, can be strong for use in tires, ballistic clothing, and shielding for personnel, while remaining flexible, durable, and able to withstand temperatures of as low as -35 degrees Celsius without deforming. The polymer blend can have an ability to accept fillers without coming apart. [00068] In embodiments, the polymer composition can include a minimum amount of at least ten percent by weight of an emulsion polymerized acrylonitrile butadiene polymer with the remainder consisting of the compatibilized silica. The butadiene can be liquid 1,3 -butadiene.

[00069] The compatibilized silica can have an organosilicon coupling agent bound to its surface, with from about 2 percent to about 10 percent by weight of organosilicon per weight of silica, thereby forming the compatibilized silica.

In embodiments, the polymer composition can be a blend of polymers. The polymers can be: polyolefm, polyalphaolefm, polyesters, polyamide, polycarbonates, polyphenylene oxide, polyacrylate, polyurethane, terpolymer of ethylene propylene and a non-conjugated diene, fluroelastomer, chloro- elastomers, polyisoprene, polybutadiene, polyisobutyldiene, polychloroprene, polyvinyl chloride, styrene butadiene rubber, acrylonitrile butadiene rubber, polyepoxide, ethylene interpolymers, block copolymers of styrene butadiene, cross-linked polymers of the above list, homo polymers and block copolymers of styrene isoprene, copolymers of acrylates, vinyl monomers, or combinations thereof. [00071] The polymer composition with the compatibilized silica in blends of acrylonitrile butadiene polymer can also include polyvinyl chloride polymer. From about 20 percent to about 50 percent by weight of the polyvinyl chloride polymer can be used with at least 10 percent by weight of the acrylonitrile butadiene polymer. The polymer composition can include a minimum amount of at least 10 percent by weight of 15:50 acrylonitrile to butadiene polymer, with the remainder consisting of the compatibilized silica.

[00072] One or more embodiments relate to articles formed from or made of the polymer composition described herein. The article can be any article described herein, or the like. The formed article can be chemical resistant to biological and chemically warfare components, for use as gas masks, boots for soldiers, protective clothing to resist arc flashing, and clothing that protects against biological organisms that eat flesh.

[00073] The organosilicon can be present as an average tetrameric structure having a

T.sup.3/T.sup.2 ratio of 0.75 or greater as measured by .sup.29 Si CPMAS NMR. The terms "T.sup.2" and "T.sup.3" refer to bi(T2)- and tri(T3)-fold Si-O-linked silicons. "Si CPMAS NMR" refers to silicon cross polarization magic angle spinning nuclear magnetic resonance, with sup.29 referring to the atomic weight of the isotope of silicon being analyzed.

[00074] The coupling agent can be bound to a surface of the silica in amounts from about 1 percent to about 25 percent by weight of organosilicon based on the weight of the silica.

The compatibilized silica can have a T.sup.3/T.sup.2 ratio of 0.9 or greater as measured by .sup.29 Si CPMAS NMR. [00076] The compatibilized silica and nitrile polymer blend in latex form can have a nitrile polymer with a Mooney viscosity, (ML 1+4 at 100 C), from 10 to 100, and an acrylonitrile composition ranging from 10 percent to 50 percent by weight.

[00077] The process of making the polymer composition can be carried out while the polymers are in latex form. Emulsion polymerized latex, as the term is herein used, refers to the reaction mixture prior to the coagulation stage in an emulsion polymerization process.

[00078] In one or more embodiments, fillers can be added to the polymer composition, such as carbon black. The polymer composition can include from about 1 percent to about 50 percent by weight of a carbon black, which can be a mixture of two different carbon blacks. As such, silica-carbon black compositions can be attainable with uniform high loads of total filler and quantitative incorporation of the fillers.

[00079] The polymer composition can include other polymers made in latex form including conjugated diene-based polymers, polymers based on vinyl monomers, and combinations of conjugated dienes with vinyl monomers. Suitable vinyl monomers can include those vinyl monomers described herein for use with the processes, compositions, and articles described herein.

[00080] The polymer composition can include natural rubber, styrene -butadiene rubber

(SBR), acrylonitrile-butadiene rubber (NBR), acrylonitrile-butadiene-styrene polymer (ABS), polybutadienes, polyvinylchloride (PVC), polystyrene, polyvinylacetate, butadiene-vinyl pyridine polymers, polyisoprenes, polychloroprene, neoprene, styrene-acrylonitrile copolymer (SAN), blends of acrylonitrile-butadiene rubber with polyvinylchloride, and the like. The polymer composition can have at least one copolymer, a homopolymer, a cross-linked polymer, a partially cross-linked polymer, or combinations thereof.

The polymer composition can be made by treating a silica with a coupling agent in aqueous suspension to form a compatibilized silica slurry. The compatibilized silica slurry can have an aqueous portion and a compatibilized silica.

The compatibilized silica can have an organosilicon bound to its surface at 2 percent to 25 percent by weight of an organosilicon per weight of silica. The compatibilized silica can have an average particle size between 1 nanometer (nm) and 15 microns. Silica that is not agglomerated can have an average particle size ranging between 1 nanometer and 15 microns. The silica can be a fumed silica, such as a pyrogenic silica, an amorphous silica, such as diatomaceous earth, faujasite, or combinations thereof.

Finely divided silica can be formed into an aqueous slurry and treated with a solution of a coupling agent, which can chemically bind to the silica surface. A variety of compounds known in the prior art can be used as the coupling agent for coupling hydrophilic filler materials, such as glass fibers, silica, and the like, to hydrophobic materials, such as natural and synthetic polymers useful as rubbers or thermoplastic materials. Organosilicon compounds are well known for bonding silica to natural and synthetic polymers.

One or more embodiments relate to a process for forming a polymer blend with a compatibilized silica, and to articles and compositions formed from the process.

In a first embodiment, the process can include treating a silica to form a compatibilized silica slurry, and then creating a silica styrene butadiene polymer latex with silica acrylonitrile butadiene polymer.

In the first embodiment, a compatibilized silica and nitrile polymer blend in latex form can be created. The formed compatibilized silica and nitrile polymer blend can have a Mooney viscosity (ML 1+4 at 100 C) from 10 to 100, and an acrylonitrile composition from 10 percent to 50 percent by weight. The first embodiment can include a process that can be carried out while the polymers are in a latex form.

The process can be configured for application to natural rubber latexes and polymerized latexes.

The process can use emulsion polymerization, that is, the polymers can be polymerized into a latex in a reaction mixture prior to a coagulation stage. The terms "latex" or "latex form", as used herein, refer to an aqueous colloid/emulsion of rubber particles.

The various embodiments described herein can all be performed with polymer latexes, to which other components can be added, such as fillers, antioxidants, UV stabilizers, and carbon black. These processes can form silica-carbon black compositions with uniform high loads of total filler and quantitative incorporation of the fillers.

The processes can be applied to other polymers made in latex form including conjugated diene polymers, polymers based on vinyl monomers, and combinations of conjugated dienes with vinyl monomers. Suitable vinyl monomers usable herein can include any vinyl monomer described herein and the like.

For example, the polymers can be natural rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), acrylonitrile-butadiene-styrene polymer (ABS), polybutadienes, polyvinylchloride (PVC), polystyrene, polyvinylacetate, butadiene-vinyl pyridine polymers, polyisoprenes, polychloroprene, neoprene, styrene-acrylonitrile copolymer (SAN), blends of acrylonitrile-butadiene rubber with polyvinylchloride, and the like.

To form the compatibilized silica and nitrile polymer blend in latex, surfactants can be used, such as soaps. An initiator can be used, such as pinane hydroperoxide. An activator can be used, such as ferrous sulfate. The soap can be obtained from MeadWestvaco, and can be supplemented with a caustic, such as sodium hydroxide. The soap can be added directly to feed stocks of monomers of styrene, butadiene, and acrylonitrile. The butadiene can be liquid 1 ,3- butadiene.

[00094] Emulsion polymerization for all the processes disclosed herein can occur at temperatures ranging from 1 degree Celsius to 30 degrees C Celsius. The conversion for the emulsion polymerizations disclosed herein can range from 59 percent to 80 percent.

[00095] The term "natural polymer", as used herein, refers to polymers made from rubber obtained from botanical sources and the like. The term "synthetic polymer", as used herein, refers to fossil fuel derived polymers that have rubber properties or elastomeric properties, and the like. Mixtures of natural and synthetic polymers can be used.

[00096] The polymer latexes can be emulsions with a solids content ranging from 5 percent to 75 percent by weight. [00097] The process for forming a polymer blend with a compatibilized silica can include treating a silica with a coupling agent in aqueous suspension to form a compatibilized silica slurry.

[00098] The aqueous suspension can include water, soaps, emulsifiers, surfactants, or thickeners, including but not limited to viscosity modifiers, such as starch or carboxyl methyl cellulose.

[00099] The silica can be treated with a coupling agent, such as an organosilicon bound to a surface of the silica, with the organosilicon covering from one percent to twenty five percent by weight per weight of the silica.

[000100] Figure 1 shows the first embodiment of the process. [000101] Step 100 can include forming a compatibilized silica and nitrile polymer blend in latex form by treating a silica with a coupling agent in an aqueous suspension to form a compatibilized silica slurry. [000102] The coupling agent can be an organosilicon that can chemically react with a surface of silica to form a bond thereto.

[000103] Step 102 can include blending at least a portion of the compatibilized silica slurry with a styrene butadiene polymer latex, forming a silica styrene butadiene polymer latex.

[000104] Step 104 can include blending at least a portion of the compatibilized silica slurry with an acrylonitrile butadiene polymer latex, forming a silica acrylonitrile butadiene polymer latex.

[000105] Step 106 can include blending the silica styrene butadiene polymer latex with the silica acrylonitrile butadiene polymer latex, forming a compatibilized silica and nitrile polymer blend in latex form.

[000106] The organosilicon compound can have from one to three readily hydro lyzable groups attached directly to a silicon atom, and at least one organic group attached directly to the silicon atom. The organic group attached directly to the silicon atom can have at least one functional group. The functional group can be a functional group capable of undergoing a chemical reaction with the polymer during curing of the polymer.

[000107] The functional group can be chosen based on the particular polymer and the particular fabrication of the elastomeric compound. For example, if an embodiment includes a styrene -butadiene rubber with silica, which can be cured via cross-linking reactions involving sulfur compounds, an organosilicon compound with at least one organic group that can have mercapto, polysulfide, thiocyanato (— SCN), a halogen and/or amino functionality, can be used as the coupling agent. Correspondingly, at least one organic group of the organosilicon compound can have ethylenic unsaturation or an epoxy group, such that the silica filled polymer can undergo a peroxy type of curing reaction.

[000108] Representative of the hydro lyzable groups commonly employed in such coupling agents include: halogens, hydrogen, hydroxyl, lower alkoxy groups, such as methoxy, ethoxy, propoxy, and like groups.

[000109] For example, in embodiments in which the polymer composition is made with a styrene -butadiene rubber, which can be cured via cross-linking reactions involving sulfur compounds, the coupling agent can be an organosilicon compound with at least one organic group being a mercapto, a polysulfide, a thiocyanato (— SCN), or a halogen and/or amino functionality. Correspondingly, at least one organic group of the organosilicon compound can have ethylenic unsaturation or an epoxy group, such that the silica filled polymer can undergo a peroxy type of curing reaction.

[000110] The process can use monomers that are homopolymers, fully cross-linked copolymers, partially cross-linked polymer, copolymers, or combinations thereof.

[000111] The formed styrene butadiene polymer latex, the silica styrene butadiene polymer latex, and/or the acrylonitrile butadiene polymer latex can additionally comprises a polyisoprene.

[000112] The process can use a silica with an average particle size ranging from 0.1 microns to 20 microns.

[000113] The process can use as the silica a fumed silica, an amorphous silica, or combinations thereof.

[000114] Step 108 can include adding a carbon black slurry to at least one of the monomers in latex form.

[000115] The process can use as the coupling agent a component that has the general x— (C¾)_y— f Si— z₂

structure: ¾ . "X" can be a functional group selected from the group consisting of: an amino group, a polyamino alkyl group, a mercapto group, a polysulfide, an epoxy group, a vinyl group, an acryloxy group, and a methacryloxy group, "y" can be an integer equal to or greater than 0. "Z.sub.l", "Z.sub.2", and "Z.sub.3" can each be independently selected from the group consisting of: hydrogen, C.sub.l-C.sub.18 alkyl, aryl, cycloalkyl, aryl alkoxy, and halo-substituted alkyl. At least one of "Z.sub. l", "Z.sub.2", and "Z.sub.3" can be alkoxy, hydrogen, halogen, or hydroxyl. Other embodiments of processes, compositions, and articles described herein can include or can use the coupling x— (C¾)_y— f Si— z₂

agent with the general structure: ^Zi

[000116] The coupling agent can be or include bis(trialkoxysilylalkyl)polysulfide, or those from the group consisting of: trialkylsilanes, dialkylsilanes, trialkylalkoxysilanes, trialkylhalosilanes, dialky alkoxy silanes, dialkyldialkoxysilanes, dialkylalkoxyhalosilanes, trialkylsilanols, alkyltrialkoxysilanes, alky ldialkoxy silanes, alkyldialkoxyhalosilanes, and monoalkylsilanes with the alkyl group being a C.sub. l to C.sub.18 linear, cyclic, or branched hydrocarbon, or combinations thereof. In one or more embodiments, one or two alkyl groups can be replaced with a phenyl or benzyl group, or one to two alkyl groups can be replaced with a phenyl, benzyl, or alkoxy substituted alkyl group.

[000117] The coupling agent can be a bis(trialkoxysilylalkyl)polysulfide containing two to eight sulfur atoms, in which alkyl groups can be C.sub. l-C.sub.18 alkyl groups, and alkoxy groups can be C.sub. l-C.sub.8 alkoxy groups.

[000118] The silica can be nano-sized silica, such as polyhedral oligomeric silsesquioxane

(POSS).

[000119] The coupling agent can be a silane or another organosilicon compound. An organosilicon compound is one that contains carbon— silicon bonds.

[000120] Step 110 can include coagulating the compatibilized silica and nitrile polymer blend after it is in latex form. [000121] Step 112 can include drying the coagulated compatibilized silica and nitrile polymer blend to remove some water. [000122] The compatibilized silica slurry can contain from 1 percent to 40 percent by weight silica.

[000123] The process can include using an amount of coupling agent that ranges from 1 part to 25 parts by weight of coupling agent per 100 parts by weight of silica.

[000124] The process described in Figure 1 can include using an amount of the compatibilized silica slurry that is within the range of 5 percent to 80 percent by weight based on the weight of the solids in either the silica styrene butadiene polymer latex or the silica acrylonitrile butadiene polymer latex.

[000125] Step 114 can include adding an extender oil, an antioxidant, or combinations thereof to at least one of the polymer latexes.

[000126] One or more embodiments relate compositions and articles made from the process of Figure 1.

[000127] Figure 2 depicts a process for forming a blend of an acrylonitrile styrene butadiene terpolymer latex blend with compatibilized silica. The process depicted in Figure 2 can create an acrylonitrile butadiene polymer latex and styrene butadiene polymer latex.

[000128] Step 200 can include blending a styrene butadiene polymer latex with an acrylonitrile butadiene polymer latex, forming an acrylonitrile butadiene polymer and styrene butadiene polymer latex blend.

[000129] Step 202 can include treating a silica with a coupling agent in aqueous suspension to form a compatibilized silica slurry. The coupling agent can chemically react with a surface of the silica to bond the coupling agent thereto.

[000130] Step 204 can include blending the compatibilized silica slurry with the acrylonitrile butadiene polymer and styrene butadiene polymer latex blend, forming the acrylonitrile styrene butadiene terpolymer latex blend with compatibilized silica in latex form. [000131] Step 206 can include blending from 2 percent to 80 percent by weight of the styrene butadiene polymer latex with 1 percent to 30 percent by weight of the acrylonitrile butadiene polymer latex, and with 1 percent to 30 percent by weight of the compatibilized silica slurry. The amount of the compatibilized silica slurry can be within the range of about 5 percent to 80 percent by weight based on the weight of the solids in the latexes.

[000132] The process depicted in Figure 2 can use the same polymers as the process depicted in Figure 1 , and can include adding a carbon black slurry to at least one of the latexes.

[000133] The coupling agent usable in the process depicted in Figure 2 can be an organosilicon compound. The coupling agent can be a bis(trialkoxysilylalkyl)polysulfide containing two to eight sulfur atoms in which the alkyl groups are C.sub. l-C.sub.18 alkyl groups, and the alkoxy groups are C.sub. l-C.sub.8 alkoxy groups. The organosilicon compound can have from one to three readily hydrolyzable groups attached directly to the silicon and at least one organic group attached directly to the silicon atom. The organic group attached directly to the silicon atom can have at least one functional group. The functional group can be a functional group capable of undergoing a chemical reaction with the polymer during curing of the polymer.

X (CH₂)_y— f Si Z₂

[000134] The coupling agent can have as the general structure: ¾ , as described herein. The amount of coupling agent used in the process can range from about 1 part to about 25 parts by weight of coupling agent per 100 parts by weight of silica.

[000135] The process depicted in Figure 2 can include using an amount of the compatibilized silica slurry within the range of about 5 percent to 80 percent by weight based on the weight of the solids in either the silica styrene butadiene polymer latex or the silica acrylonitrile butadiene polymer latex. [000136] Step 208 can include adding a filler. The filler can be selected from the group consisting of: diatomaceous earth, ground pecan shells, cellulosic materials, ground peanut shells, talc, ground coal, bagasse, ash, perlite, silage, clay, calcium carbonate, biomass, or combinations thereof.

[000137] Step 210 can include adding an antioxidant to the monomers of the emulsion polymerization process. The antioxidant can be a phenolic antioxidant, a phosphite, a bis phenol, an amine antioxidant, or combinations thereof.

[000138] One or more embodiments relate compositions and articles made from the process of Figure 2.

[000139] Figure 3 depicts a third embodiment of the process that forms a blend of acrylonitrile butadiene polymer and styrene butadiene polymer latex blend with compatibilized silica prepared by an emulsion polymerization process.

[000140] Step 300 can include treating a silica with a coupling agent in aqueous suspension to form a compatibilized silica slurry. Step 300 can be performed in the same manners as described with respect to Figures 1 and 2, or any other manner described herein.

[000141] Step 302 can include blending at least a portion of the compatibilized silica slurry with a styrene butadiene polymer latex, forming a silica styrene butadiene polymer latex.

[000142] Step 304 can include blending silica styrene butadiene polymer latex with an acrylonitrile butadiene polymer latex, forming a blend of acrylonitrile butadiene polymer and styrene butadiene polymer latex with compatibilized silica.

[000143] One or more embodiments relate compositions and articles made from the process of Figure 3.

[000144] Figure 4 depicts a fourth embodiment of the process to form a compatibilized silica in a latex blend of acrylonitrile butadiene polymer and styrene butadiene polymer. [000145] Step 400 can include treating a silica with a coupling agent in aqueous suspension to form a compatibilized silica slurry. Step 400 can be performed with any coupling agent described herein, such as those described in Figures 1-3.

[000146] Step 402 can include blending at least a portion of the compatibilized silica slurry with an acrylonitrile butadiene polymer latex, forming a silica acrylonitrile butadiene polymer latex.

[000147] Step 404 can include blending a styrene butadiene polymer latex with the silica acrylonitrile butadiene polymer latex, forming the compatibilized silica in a latex blend of acrylonitrile butadiene polymer and styrene butadiene polymer.

[000148] One or more embodiments relate compositions and articles made from the process of Figure 4.

[000149] Figure 5 depicts a fifth embodiment of the process for forming a compatibilized silica and nitrile polymer blend in latex form. [000150] Step 500 can include treating a silica with a coupling agent in an aqueous suspension to form a compatibilized silica slurry. Step 500 can be performed with any coupling agent described herein, such as those described in Figures 1-4.

[000151] Step 502 can include blending at least a portion of the compatibilized silica slurry with a styrene butadiene polymer latex, forming a silica styrene butadiene polymer latex.

[000152] Step 504 can include blending an acrylonitrile butadiene polymer latex into the silica styrene butadiene polymer latex, forming a compatibilized silica and nitrile polymer blend in latex form.

[000153] In one or more embodiments, the compatibilized silica slurry can contain from one percent to thirty percent by weight silica. For example, the compatibilized silica slurry can contain from about 10 percent to about 15 percent by weight of silica, and up to twenty percent by weight of the coupling agent. [000154] The coupling agent can be a silane or another organosilicon compound. An organosilicon compound is a compound that contains carbon— silicon bonds.

[000155] Silica that is not agglomerated can have an average particle size ranging from about 0.1 nanometer to 200 nanometers. In one or more embodiments, a nano- sized silica can be used as the silica, such as polyhedral oligomeric silsesquioxane (POSS). The silica can be a fumed silica, such as a pyrogenic silica, an amorphous silica, such as diatomaceous earth, faujasite, or combinations thereof. The silica can be finely divided silica formed into an aqueous slurry and treated with a solution of the coupling agent. [000156] The coupling agent can be chemically bond to at least 30 percent by weight of the silica surface. The coupling agent can have the capacity to chemically react with the surface of the silica to bond the coupling agent thereto. The coupling agent can bond to the surface of the silica by covalent bonding. The coupling agent can be a variety of compounds known in the prior art for use in coupling hydrophilic filler materials, such as glass fibers, silica, and the like, to hydrophobic materials, such as natural and synthetic polymers useful as rubbers or thermoplastic materials. The amount of coupling agent can range from about one to about twenty five parts by weight of coupling agent per one hundred parts by weight of silica. [000157] In embodiments, the process can be applied to a styrene -butadiene rubber to provide a silica composition that can be cured via cross-linking reactions involving sulfur compounds. As such, the coupling agent can be an organosilicon compound with at least one organic group having a mercapto, polysulfide, thiocyanato (— SCN), or a halogen and/or amino functionality. At least one organic group of the organosilicon compound can have ethylene unsaturation or an epoxy group, such that the silica filled polymer can undergo a peroxy type of curing reaction.

[000158] In one or more embodiments, one or two alkyl groups can be replaced with a phenyl or benzyl group, or one to two alkyl groups can be replaced with a phenyl, benzyl, or alkoxy substituted alkyl group.

[000159] The polymers can be recovered once coagulation has occurred, and once the polymer has been contacted with the compatibilized silica slurry.

[000160] During the process, temperature and reaction times can be varied within wide limits during the blending. In embodiments, temperatures can range from ambient temperature to up to about one hundred twenty five degrees Celsius.

[000161] The blending of the latexes can be performed by using a common tank and then blending with a pump impeller, at a rate ranging from 10 rpm to 80 rpm and for a time period ranging from 5 minutes to 1.5 hours.

[000162] During the process, an amount of time used for effecting the reaction between the hydrolyzed coupling agent and the silica can be varied within relatively wide limits, which can range from four hours to about forty eight hours depending on the temperature employed.

[000163] During the process, the amount of the silica added to the latex or latexes can be varied within wide ranges depending, in part, on the coupling agent employed, the nature of the polymer latex, the use of other fillers, such as carbon black, and the end use to which the polymer is subjected. For example, the amount of the silica added to the latex or latexes can range from about 1 percent by weight to about 70 percent by weight. [000164] The silica can include chip silica, which is untreated, as well as pretreated silica.

[000165] In embodiments, the compatibilized silica slurry can range from about five percent to about sixty percent based on the weight of solids in the polymer latex.

[000166] The styrene butadiene polymer latexes can be emulsions that can flow at ambient temperatures, allowing the styrene butadiene polymer latex to be pourable. [000167] A portion of the compatibilized silica slurry and the styrene butadiene polymer latex can be blended by pumping each to a common tank and agitating the mixture at a rate sufficient to keep the emulsion in suspension at operating temperatures. For example, the mixture can be agitated using a pump impeller at a rate ranging from 5 rpm to 80 rpm for 5 minutes to 1.5 hours.

[000168] The silica styrene butadiene polymer latex can include a ratio of about 50:50 of the compatibilized silica slurry to the styrene butadiene polymer latex.

[000169] The portion of the compatibilized silica slurry and the acrylonitrile butadiene polymer latex can be blended by pumping each to a common tank and agitating the mixture at a rate sufficient to keep the emulsion in suspension at operating temperatures. For example, the mixture can be agitated using a pump impeller at a rate ranging from 5 rpm to 80 rpm for 5 minutes to 1.5 hours.

[000170] The formed silica acrylonitrile butadiene polymer latex can include a ratio of about 50:50 of the compatibilized silica slurry to the formed silica acrylonitrile butadiene polymer latex.

[000171] In embodiments, the silica styrene butadiene polymer latex with the silica acrylonitrile butadiene polymer latex can be blended by flowing the latexes into a common tank and agitating the mixture. For example, the polymer latexes can be agitated using a impeller of a pump at a rate of 5 rpm to 80 rpm, and for a time period ranging from 5 minutes to 1.5 hours.

[000172] One or more embodiments of the process can include adding a carbon black slurry to at least one of the polymer latexes. The carbon black slurry can be or include furnace carbon black which can include high structure carbon black, low structure carbon black, or acetylene carbon black.

[000173] The carbon black slurry can be added by flowing the carbon black into one or more of the common tanks described above. [000174] For example, from about 5 percent to about 40 percent by weight of the solids in the carbon black slurry can be added to one or more of the common tanks. The carbon black slurry can be added to the latex in ranges of 1 percent to 80 percent by weight.

[000175] From about 0.1 percent to about 60 percent by weight of an extender oil can be added to at least one of the polymer latexes. The extender oil can be naphthenic oil, a hydrocarbon based oil, synthetic oil, aromatic oil, low polycyclic aromatic hydrocarbon oil (PAH), or combinations thereof.

[000176] An antioxidant can be added to the latex in amounts ranging from about 2 percent to about 0.05 percent by weight. The antioxidant can be added to at least one of the polymer latexes or to combinations thereof. The antioxidant can be a phenolic antioxidant, a phosphite, a bis phenol, an amine antioxidant, or combinations thereof.

[000177] Fillers can be added to any one or more of the blend described herein. For example, from about 0.1 percent to about 50 percent by weight of filler can be added to one or more of the blends described herein.

[000178] The polymer can be recovered once it has been coagulated and once the polymer has been contacted with the compatibilized silica slurry.

[000179] The aqueous suspension can include water, soaps, emulsifiers, surfactants, and thickeners including viscosity modifiers, such as starch or carboxy methyl cellulose.

[000180] An activator, a free radical initiator, and a terminating agent can all be used in the emulsion polymerization process in amounts from 0.1 percent to 5 percent by weight in combination. The activator can be a peroxide.

[000181] In embodiments, a curing package for cross-linking the formed polymers can be used with the emulsion polymerization process, such as a zinc oxide, another organic peroxide, or an acrylate.

[000182] In one or more embodiments, the compatibilized silica slurry can contain from 1 percent to 30 percent by weight silica. For example, the compatibilized silica slurry can contain about 10 percent to about 15 percent by weight of silica, and up to 20 percent by weight of the coupling agent.

[000183] Temperature and reaction times can be varied within wide limits during the blending. In embodiments, temperatures can range from ambient up to about 125 degrees Celsius. The blending can be performed using impeller agitation. The amount of time used for effecting the reaction between the hydrolyzed coupling agent and the silica can be varied within relatively wide limits ranging from 4 hours to 48 hours, depending on the temperature employed.

[000184] The amount of the silica added to the latex can be varied within wide ranges, depending in part on the coupling agent employed, the nature of the polymer, the use of other fillers, such as carbon black, and the end use to which that polymer is subjected. For example, the amount of the silica added to the latex or latexes can range from about 25 percent to about 80 percent by weight.

[000185] In embodiments, the compatibilized silica slurry can be within the range of about

5 percent to about 60 percent based on the weight of the solids in the polymer latex.

[000186] The process can also include blending at least a portion of the compatibilized silica slurry with a styrene butadiene polymer latex, forming a silica styrene butadiene polymer latex that can be a flowing and pourable emulsion at ambient temperatures.

[000187] The portion of the compatibilized silica slurry with the styrene butadiene polymer latex can be blended by pumping each to a common tank and agitating the mixture at a rate sufficient to keep the emulsion in suspension at operating temperatures. For example, the mixture can be agitated using impeller agitation.

[000188] The silica styrene butadiene polymer latex can include a ratio of about 25:75 of the compatibilized silica slurry to the styrene butadiene polymer latex.

[000189] In one or more embodiments, at least a portion of the compatibilized silica slurry can be blended into an acrylonitrile butadiene polymer latex, forming a silica acrylonitrile butadiene polymer latex.

[000190] The portion of the compatibilized silica slurry with the acrylonitrile butadiene polymer latex can be blended by pumping each to a common tank and agitating the mixture at a rate sufficient to keep the emulsion in suspension at operating temperatures.

[000191] The formed silica acrylonitrile butadiene polymer latex can include a ratio of about 25:75 of the compatibilized silica slurry to the formed silica acrylonitrile butadiene polymer latex.

[000192] At least one of the polymers can be or include a copolymer, a homopolymer, a cross-linked polymer, partially cross-linked polymer, or combinations thereof. At least one of the polymers can be natural or synthetic polymers.

[000193] Acrylonitrile butadiene polymer latex can be mixed with a polyisoprene, such as a natural rubber, a synthetic rubber, a rubber latex blend, rubber crumbs, or combinations thereof. [000194] A portion of the silica styrene butadiene polymer latex can be blended with the silica acrylonitrile butadiene polymer latex, forming the compatibilized silica and nitrile polymer blend.

[000195] The silica styrene butadiene polymer latex with the silica acrylonitrile butadiene polymer latex can be blended by flowing the latexes into a common tank and agitating. The polymer latexes can be blended to have a ratio of acrylonitrile to styrene from 3:1 to 8: 1, a ratio of styrene to butadiene from 0.06: 1 to 0.14: 1, a ratio of butadiene to styrene from 7: 1 to 14: 1, a ratio of acrylonitrile to butadiene of 0.4: 1 to 0.75 : 1 , and a ratio of butadiene to acrylonitrile from 1.3 : 1 to 2.5 : 1.

[000196] One or more embodiments of the process can include adding a carbon black slurry to at least one of the latexes. The carbon black slurry can be or include furnace carbon black, which can include high structure carbon black, low structure carbon black, and acetylene carbon black. [000197] The carbon black slurry can be added by flowing the carbon black into the common tank, as described above. For example, from about 1 percent to about 50 percent by weight of the carbon black slurry can be added to one or more of the common tanks.

[000198] The polymer composition can include an extender oil, an antioxidant, or any combination thereof, which can be added to at least one of the latexes. For example, from about 4 percent to about 60 percent by weight of the extender oil can be added to at least one of the polymer latexes, from about 0.1 percent to about 3 percent by weight of the antioxidant can be added to at least one of the polymer latexes, or combinations thereof.

[000199] The polymer composition can include fillers, which can be added to any one or more of these blends. For example, from 0.1 percent to 50 percent by weight of filler can be added to one or more of these blends.

[000200] One or more embodiments can include a compatibilized silica in a latex blend of acrylonitrile butadiene polymer and styrene butadiene polymer.

[000201] At least a portion of the styrene butadiene polymer latex can be blended with the acrylonitrile butadiene polymer latex, forming an acrylonitrile and styrene butadiene polymer latex blend that can be a flowing and pourable emulsion at ambient temperatures. [000202] The coupling agent can have the capacity to chemically react with at least 20 percent by weight of the surface of the silica to covalently bond the coupling agent thereto forming the compatibilized silica.

[000203] The acrylonitrile and styrene butadiene polymer latex blend can be blended with the compatibilized silica slurry, forming the compatibilized silica in the acrylonitrile and styrene butadiene polymer latex blend.

[000204] In one or more embodiments, from about 2 percent to about 80 percent by weight of the styrene polymer latex can be blended with from about 1 percent to about 30 percent by weight of the acrylonitrile butadiene polymer latex, and with from about 1 percent to about 30 percent by weight of the compatibilized silica slurry. The amount of the compatibilized silica slurry can range from about 5 percent to 80 percent based on the weight of the solids in the latexes.

[000205] Examples describing embodiments of one or more portions of the process are described below, which can be used to make one or more embodiments of compositions and articles described herein.

[000206] EXAMPLE 1 : Preparation of an SBR-Silica-Carbon Black

[000207] A. Preparation of Compatibilized Silica Slurry [000208] An aqueous solution of silane can be prepared by charging to a vessel: 55.1 g of

Silquest.RTM. A-189 (OSi Specialties), 27 g of isopropanol, 1.1 g of glacial acetic acid, and 27 g of water, which can form an initially cloudy mixture.

[000209] The initially cloudy mixture can be agitated at high speed, such as 50 rpm, and at room temperature, such as 72 Fahrenheit, until the mixture is clear. In one or more embodiments, the initially cloudy mixture can be agitated at high speed, such as at 50 rpm, and at an elevated temperature ranging from 60 degrees Celsius to 66 degrees Celsius, until the mixture is clear.

[000210] The high speed agitation can be performed for from about ten to about twenty minutes, after which, an additional 28 g of water can be added, which can cause the mixture to become cloudy.

[000211] Agitation can be continued for from about fifteen to about twenty minutes until the mixture is clear again and a solution is formed.

[000212] To a separate vessel equipped with a stirrer: 16 lbs of water and 4.05 lbs of fine- particle, dry silica, HiSil.RTM. 233 can be charged and agitated for about fifteen minutes to wet and disperse the silica, forming an aqueous solution of silane.

[000213] The aqueous solution of silane can then be added, with continued agitation, with twenty five percent sodium hydroxide, which can be heated to 76 degrees Celsius. As such, the pH can be increased to 7.5-8.0. The temperature can be maintained at 76 degrees Celsius for about 4 hours, and then allowed to cool to about 60 degrees Celsius. At this point the compatibilized silica slurry can be added to the latex stage of a continuous emulsion process, or can be fed batch- wise to a concentrated polymer latex.

[000214] B. Blend of compatibilized silica slurry with styrene butadiene rubber latex

[000215] Compatibilized silica slurry can be prepared as described in Part A of Example 1 above.

[000216] The compatibilized silica slurry can be charged to an agitated vessel containing a mixture of 35 lbs of SBR latex containing 7 or 8 lbs 1502-type rubber and 6 PPD as an antioxidant emulsion containing Santoflex.RTM. 134 made by Sinorgchem, and the mixture can be held at 66 degrees Celsius or 60 degrees Celsius.

[000217] Hot carbon black slurry can be charged to the initial mixture. For example, about

20 lbs of the hot carbon black slurry containing about 10 percent by weight of N234-type carbon black and about 3 lbs of hot oil emulsion containing 62.8 percent by weight SundexRTM 8125. This mixture can be agitated for 30 minutes at 66 degrees Celsius at ambient pressure, or at 60 degrees Celsius at ambient pressure.

[000218] The above latex blend can be blended slowly, such as at a rate of 50 rpm, added to a larger agitating vessel containing from about 45 pounds to about 50 pounds of water and sufficient sulfuric acid to give produce a pH of 4. In one or more embodiments, the above latex blend can be instantaneously mixed in the vessel using steam containing from about 45 pounds to about 50 pounds of water and sufficient sulfuric acid to produce a pH of 4.

[000219] The rates of addition of the latex blend and the sulfuric acid can be varied to maintain the pH of the resulting coagulation serum in the range of 4-5 pH over the 38 minute time period that the latex blend is added. [000220] An additional thirty eight minutes of mix time and an additional portion of the acid can be used as needed to allow the product particle size to grow, such as to a size of a crumb of 1 millimeter to 30 millimeters, and to clear the serum of free latex, as is commonly done by those familiar with the art. [000221] The wet composition particle or crumb size achieved by this coagulation can be similar to that obtained from coagulations without silica.

[000222] Visual inspection and chemical analysis of the dried composition can verify that essentially all solid and liquid components added to the latex mixture are absorbed and uniformly distributed. Silica absorption can be about 96 percent to about 99 percent of charge as estimated by ash analysis.

[000223] EXAMPLE 2: Preparation of an styrene butadiene rubber-silica-carbon black composition

[000224] A. Preparation of Compatibilized Silica Slurry

[000225] An aqueous solution of silane can be prepared by charging to a vessel: 100 g of

Silquest.RTM. A-189, 50 g of isopropanol, 2 g of glacial acetic acid, and 47 g of water, forming a cloudy mixture. The initially cloudy mixture can be agitated at high speed and room temperature until clear, such as for about 12 minutes to about 22 minutes, after which an additional 50 g of water can be added that can cause the mixture to become cloudy. Agitation can be continued for about 12 minutes to about 22 minutes until the solution is clear.

[000226] To a separate vessel equipped with a stirrer: 15 lbs of water and 5 lbs of fine- particle dry silica HiSil RTM 233 can be charged and agitated for about 20 minutes, such that the silica becomes wet and dispersed. The aqueous solution of silane can then added with continued agitation to 25 percent sodium hydroxide, with the pH being increased to 7.5-8.0. The blend can be heated to 64 degrees

Celsius to 77 degrees Celsius. The temperature can be maintained at 64 degrees Celsius to 77 degrees Celsius for about 3.5 hours, and then allowed to cool to 60 degrees Celsius. At this point the compatibilized silica slurry can be added to the latex stage of a continuous emulsion process or can be fed batch-wise to a concentrated polymer latex.

[000227] B. Blend of compatibilized silica slurry with styrene butadiene rubber (SBR) latex [000228] The compatibilized silica slurry, prepared as described in Part A of Example 2 above, can be charged to an agitating vessel containing a latex mixture as described in Example 1. The final composition mixture can be agitated for 35 minutes at 60 degrees Celsius.

[000229] The above latex blend can be coagulated, as described in Example 1. The wet composition particle or crumb size achieved by this coagulation can be similar to or slightly larger than that obtained from coagulations without silica, such as a size of 1 millimeter to 30 millimeters. Visual inspection and chemical analysis of the dried composition can verify that essentially all solid and liquid components added to the latex mixture are absorbed and uniformly distributed. Silica absorption can be about 96 percent to about 99 percent of charge as estimated by ash analysis.

[000230] EXAMPLE 3 : Preparation of an SBR-Silica Composition

[000231] Compatibilized Silica Slurry, prepared as described in Part A of Example 2 above, can be charged to an agitated vessel containing a latex mixture prepared from 40 lbs of SBR latex containing 20 percent by weight of the 1502 SBR and 2 percent by weight Santoflex 134, which can be held at 60 degrees Celsius.

[000232] To this mixture, 3 lbs of hot oil emulsion containing 60 percent by weight of

Sundex 8125 can be charged. The mixture can then be agitated for an additional 38 minutes while maintaining a temperature of 60 degrees Celsius, after which the hot latex can be slowly charged to another vessel for coagulation, which can form a dewatered or dry crumb.

[000233] The dewatered crumb can be similar in particle size to that of SBR without silica, such as 1 millimeter to 30 millimeters, as it masses together. Visual inspection and chemical analysis of the dry crumb can show that essentially all of the oil and silica added to the latex are absorbed and uniformly distributed. Silica absorption can be 96 percent to 99 percent of the charge as estimated by ash analysis. [000234] EXAMPLE 4: Preparation of an Nitrile Butadiene Rubber (NBR)-Silica

Composition

[000235] A. Preparation of Compatibilized Silica Slurry

[000236] An aqueous solution of silane can be prepared by charging to a vessel: 20 g of

Silquest.RTM. A- 189, 15 g of isopropanol, 0.7 g of glacial acetic acid, and 10 g of water, forming an initially cloudy mixture. The initially cloudy mixture can be agitated at high speed and room temperature until clear, such as for about 10 minutes to 20 minutes, after which an additional 15 g of water can be added, which can cause the mixture to become cloudy. Agitation can be continued for about 12 minutes to about 25 minutes until the solution is clear. [000237] To a separate vessel equipped with a stirrer: 7 lbs of water and 2 lbs of fine- particle dry silica, HiSil.RTM. 233, can be charged and agitated for about 20 minutes, such that the silica becomes wet and dispersed. The aqueous solution of silane can then added with continued agitation with 25 percent sodium hydroxide, such that the pH is increased to 7.5-8.0. The blend can be heated to 70 degrees Celsius, and maintained there for about 3.5 hours, after which it can be allowed to cool to 60 degree Celsius. At this point the compatibilized silica slurry can be added to the latex stage of a continuous emulsion process or fed batch-wise to a concentrated polymer latex.

[000238] B. Blend Compatibilized Silica Slurry with NBR Latex [000239] Compatibilized silica slurry, prepared accorded to Part A of Example 4, can be charged to an agitated vessel containing a mixture of: 30 lbs of acrylonitrile butadiene polymer (NBR) latex containing 22 percent by weight Nysyn.RTM. 40-5 rubber and 200 grams of antioxidant emulsion containing 16 percent by weight Agerite Geltrol (tm) (Vanderbilt Chemical), which can be held at 60 degrees Celsius. To this initial mixture, 15 lbs of hot carbon black slurry containing 7 percent by weight N234-type carbon black can be charged. The final mixture can be agitated for 35 minutes at 60 degrees Celsius. [000240] The above latex blend can be slowly added to a larger vessel containing 30 lbs of water and sufficient sulfuric acid to give a pH of 4. The coagulation can be completed as described in previous examples. The wet composition crumb size achieved by this coagulation can be similar to that obtained from NBR coagulations without silica, such as 1 millimeter to 30 millimeters. Visual inspection and chemical analysis of the dried composition can show that essentially all solid and liquid components added to the latex mixture are absorbed and uniformly distributed. Silica absorption can be 96 percent to 99 percent by weight of charge as estimated by ash analysis.

[000241] Articles made from this material can include pneumatic tires. Articles formed form the polymer blends disclosed herein can be made by injection molding, extruding, press molding, cutting, milling, rotomolding, or combinations thereof.

[000242] The processes described herein can include coagulating the polymer at temperatures between 57 degrees Celsius and 74 degrees Celsius.

[000243] The processes described herein can include filtering the coagulated polymer to remove excess water, such as by using a screen, cellulose membrane filter,

French oil mill, or by squeezing out water from the polymer.

[000244] The processes described herein can include drying the separated polymer using heat, such as by using heat in a dryer oven, trays with heat in a dryer oven, or a fluidized bed. [000245] The processes described herein can be continuous emulsion polymerization or batch processes.

[000246] EXAMPLE 5: Latex from the emulsion polymerization process can be treated with shortstop to kill or stop the polymerization reaction, and can be further processed to remove unreacted monomers. Residual unreacted monomers can be removed via steam stripping. Finished latex can be routed to latex storage tanks. The finished latex from the storage tanks can be pumped into feed tanks and blended if necessary to achieve the product target molecular weight. The molecular weight can be determined indirectly by measuring Mooney viscosity.

[000247] Latex can be continuously pumped from the nitrile latex feed tank and/or the nitrile and styrene butadiene latex feed tank, and can be mixed with antioxidant and/or extender oil at the head tank where all of the components can be mixed together. The mixture can be pumped into a carbex tank or the like and mixed with compatibilized silica slurry, carbon black slurry, or combinations thereof.

[000248] The carbex tank can overflow into a first coagulation tank. If neat or pure extender oil is used, as opposed to oil emulsion, the mixture can be routed through a series of in-line static mixers to facilitate thorough mixing and dispersion.

[000249] The mixture can flow into a heated and stirred coagulation tank where dilute sulfuric acid coagulant can be added. Aluminum sulfate and calcium chloride can be used as coagulants when running nitrile (NBR) rubber. Acid can be fed based on pH control of the coagulation tank, whereas both alum and calcium chloride can be fed based on flow control. All three coagulants can serve to break the latex emulsion and cause rubber crumb to form. Control of crumb size can be the determining factor for coagulant addition and can take precedent over recipe values.

[000250] Tank contents can be thoroughly agitated to produce a vortex in the center of the tank. Process conditions, along with the addition of coagulant chemicals described herein, can coagulate the mixture to form a rubber crumb and water slurry, or crumb slurry.

[000251] When coagulated under the conditions described herein, the latex, oil, compatibilized silica slurry, carbon black slurry, antioxidant, and combinations thereof can be evenly dispersed. The crumb slurry can overflow from the first to a second coagulation tank to provide additional residence time for coagulation.

[000252] A soap conversion tank can provide for more residence time to complete the coagulation step. Complete coagulation can be achieved before material exits the soap conversion tank to avoid fouling of downstream equipment.

[000253] A small amount of coagulation aid can be used during coagulation to facilitate clearing serum and completing coagulation.

[000254] Centrifugal dewatering units, or spin dryers, can be used to mechanically reduce the moisture content of pigmented rubber crumb to approximately 35 percent to 40 percent by weight, allowing for a more energy-efficient dryer operation.

[000255] Rubber crumb slurry leaving a wash water tank can enter the spin dryer and be thrown against a cylindrical screen. Water can passes through the cylindrical screen and can be removed by gravity at the bottom of the spin dryer. The rubber crumb can move in an upward spiral path and be discharged through an outlet at the top thereof onto a classifier.

[000256] The classifier can be a vibrating conveyor equipped with grid bars. Grid spacing of the grid bars can be used to regulate crumb size. Smaller crumbs can fall through the grid bar spaces while over-sized crumbs can remains on top of the grid bars and be ejected via a side exit chute. [000257] Acceptable crumb can be discharged from the classifier into a wet feed rotolock valve that feeds a wet feed crumb blower. The wet feed rotolock valve can prevent blow back from the wet-feed crumb blower.

[000258] Rubber crumb can be fluidized in the spin dryer by means of air directed upwards from the bottom of the spin dryer. The upward motion of the air can partially support and suspend the rubber crumb to form a boiling mass.

[000259] Dried crumb can be discharged through openings at the end of the last dryer compartment to a crumb hopper. Discharge crumb hoppers can feed the dry crumb blowers. The dry crumb blowers can convey the dry crumb to baler scale cyclones. The rubber crumb can be gravity feed to scales above each baler, where the rubber crumb can be compressed into bale form.

[000260] The rubber crumb can be diverted to a bagging operation where it can be coated with a partitioning agent and packaged as a free flowing crumb.

[000261] EXAMPLE 6: Formation of the elastomeric composition can include first introducing 47 percent by weight of a synthetic elastomeric polymer into a finishing process area. The synthetic elastomeric polymer can include 70 percent by weight of butadiene and 30 percent by weight of styrene. [000262] Next, 10 percent by weight of compatibilized silica can be added. The compatibilized silica can include 90 percent by weight silica and with 10 percent by weight of a coupling agent.

[000263] In addition, 25 percent by weight of a crumb rubber can be added to the finishing process area. [000264] Furthermore, 8 percent by weight of a carbon black and 10 percent by weight of an extender oil can be added to the finishing process area.

[000265] The finishing process area can be kept at a temperature of 60 degrees Celsius and at an ambient pressure. The components of the composition can be allowed to react within the finishing process area for a time period of 38 minutes. [000266] A soap, water, an activator, a free radical initiator, and a terminating agent can be used in the emulsion polymerization process to form long chain polymerization.

[000267] EXAMPLE 7: A crumb rubber slurry with from 2 percent to 15 percent solids can be prepared and held in an agitating heated holding tank. The crumb rubber slurry within the agitating heated holding tank can be introduced into a coagulation step of the manufacturing process.

[000268] Latex from the emulsion polymerization process can be treated with shortstop to kill or stop the polymerization reaction, and can then be further processed to remove unreacted monomers. Residual unreacted monomers can be removed via steam stripping, and the finished latex can be routed to latex storage tanks.

[000269] The finished latex can be pumped from the latex storage tanks into feed tanks.

The finished latex can be blended in the feed tanks if necessary to achieve the product target molecular weight. The molecular weight can be determined indirectly by measuring Mooney viscosity of the finished latex.

[000270] Latex can be continuously pumped from the nitrile latex feed tank, nitrile and styrene butadiene latex feed tank, and/or styrene butadiene latex feed tank, and can be mixed with antioxidant and/or extender oil at a head tank where all components can mix together, forming a mixture that can be pumped into a carbex tank or the like.

[000271] The crumb rubber slurry can also be pumped into the carbex tank or the like at the prescribed rate based on the recipe. A compatibilized silica slurry, carbon black slurry, or combinations thereof can be added to the carbex tank or the like.

[000272] The carbex tank can overflow into a first coagulation tank. If neat or pure extender oil is used, as opposed to oil emulsion, the mixture can be routed through a series of in-line static mixers to facilitate thorough mixing and dispersion. [000273] The mixture can flow into a heated and stirred coagulation tank where dilute sulfuric acid coagulant can be added. Aluminum sulfate and calcium chloride can be used as coagulants when running nitrile rubber (NBR). Acid can be fed based on pH control of the coagulation tank, whereas both alum and calcium chloride can be fed based on flow control. All three coagulants can serve to break the latex emulsion and cause newly coagulated rubber crumb to form.

Control of newly coagulated crumb size can be the determining factor for coagulant addition and can take precedent over recipe values.

[000274] Tank contents can be thoroughly agitated to produce a vortex in the center of the tank. Process conditions, along with the addition of coagulant chemicals described herein can coagulate the mixture to form a fresh rubber crumb and water slurry.

[000275] When coagulated under the conditions described in Example 2, the latex, oil, compatibilized silica slurry, carbon black slurry, antioxidant, recycled crumb, and combinations thereof can be evenly dispersed. The combined recycled crumb and the slurry can overflow from the first to a second coagulation tank to provide additional residence time for coagulation.

[000276] A soap conversion tank can provide more residence time to complete the coagulation step. The complete coagulation can be achieved before material exits the soap conversion tank to avoid fouling of downstream equipment. A small amount of coagulation aid can be used during coagulation to facilitate clearing the serum and completing coagulation.

[000277] Centrifugal dewatering units, or spin dryers, can be used to mechanically reduce the moisture content of pigmented rubber crumb to approximately 35 percent to

40 percent by weight, allowing for a more energy-efficient dryer operation. Rubber crumb slurry leaving the wash water tank can enter a spin dryer and can be thrown against a cylindrical screen. Water can pass through the screen and be removed by gravity at the bottom of the spin dryer. The rubber crumb can move in an upward spiral path and can be discharged through an outlet at the top thereof and onto a classifier.

[000278] The classifier can be a vibrating conveyor equipped with grid bars. Grid spacing can be used to regulate crumb size. Smaller crumbs can fall through the grid bar spaces, while over-sized crumbs can remain on top of the grid bar and can be ejected via a side exit chute.

[000279] Acceptable crumb can be discharged from the classifier into a wet feed rotolock valve, which can feed a wet feed crumb blower. The wet feed rotolock valve can prevent blow back from the wet-feed crumb blower. [000280] Rubber crumb can be fluidized in the spin dryer by means of air directed upwards from the bottom of the spin dryer. The upward motion of the air can partially support and suspend the rubber crumb to form a boiling mass. Dried crumb can be discharged through openings at the end of the last dryer compartment to a crumb hopper.

[000281] Discharge crumb hoppers can feed the dry crumb blowers. The dry crumb blowers can convey the dry crumb to baler scale cyclones. The rubber crumb can be gravity feed to scales above each baler, where the rubber crumb can be compressed into bale form. The rubber crumb can be diverted to a bagging operation where it can be coated with a partitioning agent and packaged as a free flowing crumb.

[000282] While these embodiments have been described with emphasis on the embodiments, it should be understood that within the scope of the appended claims, the embodiments might be practiced other than as specifically described herein.