Thermoplastic moulding masses based on graft copolymers and block polymers

THERMOPLASTIC MOLDING MATERIALS BASED ON PROPFCOPOLYMERS AND BLOCK POLYME REN

0002description

0003The present invention relates

0004A) 5 to 98% by weight, based on the total weight of the molding compositions, of a rubber-like graft copolymer composed of

0005au) an at least partially crosslinked acrylic ester polymer formed from

0006am) 50 to 99.9% by weight, based on an), of at least one alkyl acrylate having 1 to 10 C atoms in the alkyl radical,

0007n₂) 0.1 to 5 wt .-%, based on an), a polyfunctional, crosslinking monomer and

0008on₃) 0 to 49.9% by weight, based on an), of another monomer which can be copolymerized with m) and selected from the group of vinyl alkyl ethers having 1 to 8 carbon atoms in the alkyl radical, butadiene, isoprene, styrene, acrylonitrile, methacrylonitrile ^•and / or methyl methacrylate

0009and or

0010ai;) a diene polymer composed of

0011aι ι) 60 to 100 wt .-%, based on aχ₂) one

0012Dien and

0013aι₂₂) 0 to 40 wt .-%, based on aι₂) further copolymerizable monomers from the group of vinyl alkyl ethers with 1 to 8 carbon atoms in the alkyl group, alkyl acrylates with 1 to 10 carbon atoms in the alkyl group, isoprene, styrene, acrylonitrile, methacrylonitrile and / or methyl methacrylate, a) 10 to 50% by weight .-%, based on A), one on the

0014Grafted base, grafted on

0015a ι) 50 to 95 wt .-%, based on a χ), of a vinyl aromatic monomer,

0016a ₂) 5-50 wt .-% polar, copolymerizable

0017Comonomers from the group acrylonitrile, methacrylonitrile, esters of (meth) acrylic acid with 1 to 4 carbon atoms in the alkyl radical, maleic anhydride and their imides, (meth) acrylamide and / or vinyl alkyl ether with 1 to 8 carbon atoms in the alkyl radical ,

0018B) 1 to 90% by weight, based on the total weight of the molding composition, of a copolymer

0019b :) 50 to 99% by weight of a vinyl aromatic monomer

0020and

0021b₂) 1 to 50 wt .-% monomers as for a₂₂) described

0022C) 1 to 70% by weight of a rubber-elastic block copolymer composed of at least one polymerized unit of a block CA which forms a hard phase and contains vinyl aromatic monomers

0023and / or a block C comprising a diene monomer and forming a first rubber-elastic (soft) phase_B

0024and at least one polymerized units of both a vinylaromatic monomer and a diene having elastomeric, a (optionally second or further) soft phase-forming block CB /_A.

0025where the glass temperature T_G of block C above 25 ° C and that of block C_B/ A is below 25 ° C and the phase-volume ratio of block CA to block CB / A is chosen such that the proportion of the hard phase in the entire block copolymer is 1-40% by volume and the proportion by weight of the diene is less than 50% by weight,

0026D) 0-300% by weight, based on the weight of components A) to C), of an aromatic polycarbonate, E) 0 to 20% by weight, based on the total weight of the molding compositions, customary additives and processing aids.

0027Mixtures of thermoplastic polymers based on vinyl aromatic polymers and graft rubbers are known as so-called

0028ABS or ASA polymers are known to the person skilled in the art and are commercially available. Blends of such ASA or ABS polymers with other thermoplastics, in particular polycarbonates, are also known.

0029As a result of the introduction of ever faster processing machines, such products in particular require high flowability during processing in injection molding and unbreakable demolding. When shaping by deep drawing, a high elongation at break is particularly important.

0030Various additives are generally used to optimize these properties, but they often improve only one parameter and adversely affect another desired property. Additives to improve the flowability and the deep-drawing properties often lead to losses in the mechanical properties, while additives to improve the demoldability often impair the flowability.

0031The object of the present invention was therefore to provide thermoplastic molding compositions based on ABS or ASA polymers which have a balanced range of properties.

0032This object is achieved by the thermoplastic molding compositions according to claim 1.

0033Preferred embodiments of the invention can be found in the subclaims.

0034As component A, the molding compositions according to the invention contain 5 to 98, preferably 10 to 90 and in particular 20 to 80% by weight, based on the total weight of the molding compositions, of a rubber-like graft copolymer.

0035This graft copolymer is composed of a graft base ai) with a glass transition temperature Tg of below -10 ° C. and a graft layer a) with a glass transition temperature Tg of more than 50 ° C., the proportion of the graft base aι) + a) 30 to 90 , preferably 35-85 and in particular 40 to 80% by weight and the graft correspondingly corresponds to 10 to 70, preferably 15 to 65 and in particular 20 to 60% by weight. The structure of the graft polymer A) is explained in more detail below.

0036The graft base i) is made up of

0037an) an at least partially crosslinked acrylic ester polymer

0038a) 50 to 99.9% by weight, based on an), of at least one alkyl acrylate having 1 to 10 carbon atoms in the alkyl radical

0039on₂) 0.1 to 5% by weight, based on an), of a polyfunctional, crosslinking monomer and

0040am) 0 to 49.9% by weight, based on n), of a further monomer which is copolymerizable with a) from the group of vinyl alkyl ethers having 1 to 8 carbon atoms in the alkyl radical, butadiene, isoprene, styrene, acrylonitrile, methacrylonitrile and / or methyl methacrylate

0041or

0042aι) a butadiene polymer, built up from

0043a₁₂ι) 50 to 100 wt .-%, based on aχ₂) one or more dienes, and

0044aι ₂) 0 to 50 wt .-%, based on aχ₂) further copolymerizable monomers from the group of vinyl alkyl ethers with 1 to 8 C atoms in the alkyl group, alkyl acrylates with 1 to 10 C atoms in αer alkyl group, isoprene, styrene, acrylonitrile, methacrylonitrile and / or methyl methacrylate

0045Accordingly, molding compositions can be used according to the invention which in component A either contain only one polymer) or aι₂) or a mixture of two polymers) and a_i ) included as a graft base.

0046If mixtures of polymers an) and aχ) are used, the mixing ratio is not critical, but is in the general range from 4: 1 to 1: 4, in particular from 1: 2 to 2: 1. The acrylic ester polymers) are composed of

0047am) 50 to 99.9 wt .-%, preferably 55-98 wt .-%, and esp^¬ special 60-90 wt .-% of an alkyl acrylate with 1 to 10 carbon atoms in the alkyl radical. Preferred acrylates are those with 2 to 10 carbon atoms in the alkyl radical, in particular ethyl acrylate, tert.-, iso- and n-butyl acrylate and 2-ethylhexyl acrylate, of which the latter two are particularly preferred.

0048As crosslinking monomers₂) which are used in amounts of 0.1-5, preferably 0.25 to 4 and in particular 0.5 to 3% by weight, based on an), are examples of polyfunctional monomers with at least 2 olefinic, non-conjugated double bonds, of which divinylbenzene, dialkyl fumarate, diallyl phthalate, triallyl cyanurate, trialkyl isocyanurate, tricyclodecenyl acrylate and dihydrodicyclopentadienyl acrylate are mentioned by name. Tricyclodecenyl acrylate and dihydrodicyclopentadienyl acrylate are particularly preferred.

0049Up to 49.9, preferably 5 to 44.9 and in particular 10 to 39.9% by weight and a) copolymerizable monomers from the group of the vinyl alkyl ethers having 1-8 C atoms in the Alkyl radical (for example vinyl methyl ether, vinyl propyl ether, vinyl ethyl ether), butadiene, isoprene, styrene, acrylonitrile, methacrylonitrile and / or methacrylonitrile in the preparation of an) can be used.

0050By using such comonomers, the property profile of the polymers can be controlled, for example with regard to the degree of crosslinking, which can be desirable in some cases.

0051Processes for the preparation of polymers an) are known to the person skilled in the art and are described in the literature. Corresponding products are also commercially available.

0052In some cases, production by emulsion polymerization has proven to be particularly advantageous.

0053When the graft copolymer is produced by the method described in DE-PS 12 60 135, the graft base A is first prepared; if the graft base is to be an acrylate rubber, the acrylic acid ester (s), the polyfunctional monomer a) and optionally the monomer) is polymerized in an aqueous emulsion at 20 to 100 ° C., preferably between 50 and 80 ° C. The usual emulsifiers such as the alkali salts of alkyl aryl sulfonic acids, alkyl sulfates, fatty alcohol sulfonates, salts of higher fatty acids with 10 to 30 carbon atoms or resin soaps can be used. The sodium or potassium salts of alkyl sulfonates or of fatty acids having 10 to 18 carbon atoms are preferably used. It is favorable to use the emulsifiers in an amount of 0.5 to 5% by weight, in particular 1 to 2% by weight, based on the total weight of the monomers used for the preparation of the graft base. In general, a water / monomer ratio of 2: 1 to 0.7: 1 is used. The usual persulfates, such as, for example, potassium peroxodisulfate, are used in particular as polymerization initiators; however, redox systems are also suitable. The amount of initiators (e.g. 0.1 to 1% by weight, based on the total weight of the monomers) depends in a known manner on the desired molecular weight.

0054The usual buffer substances, by means of which pH values ​​of preferably 6 to 9, for example sodium bicarbonate and sodium pyrophosphate, and up to 3% by weight of a molecular weight regulator, such as mercaptan, terpinol or dimeric α-methylstyrene, can be used as polymerization auxiliaries .

0055The precise polymerization conditions, in particular the type, dosage and amount of the emulsifier, are determined within the ranges given above such that the latex of the crosslinked acrylic ester polymer obtained has a d 50 value in the range from about 30 to 1000 nm, preferably in the range from 50 to 800 nm. The d₅Q value of the particle size is, as usual, defined as the weight average of the particle size, as determined using an analytical ole centrifuge according to the method of W. Scholtan and H. Lange, Kolloid-Z. and Z.-Polymer 250 (1972)

0056Pages 782 to 796. The ultracentrifuge measurement provides the integral mass distribution of the particle diameter of a sample. From this it can be seen what percentage by weight of the particles have a diameter equal to or below a certain size. The mean particle diameter, which is also referred to as the dso value of the integral mass distribution, is defined as the value at which 50 percent by weight of the particles have a smaller diameter and 50 percent by weight of the particles have a larger diameter than the dso value.

0057The latex preferably has a narrow particle size distribution, ie the quotient dgc - dio Q = dso

0058is preferably less than 0.5, in particular less than 0.35.

0059Instead of the polymers at), the graft copolymers A) can also diene polymers aχ₂) as a graft base. In the polymers a Polymer₂) are butadiene copolymers which, in addition to 60 to 100, preferably 70 to 99% by weight, of one or more dienes, preferably butadiene or isoprene, also contain up to 40, preferably 2 to 30% by weight of further copolymerizable monomers can. Both the alkyl acrylates described above under am) and the monomers a) are suitable as such; for detailed explanations, reference is made to the description there.

0060If the graft core is to be a diene rubber, the procedure is advantageously as follows: the elastomer, the graft base ai) is produced by am) and aχ ₂) in aqueous emulsion in a conventional manner at temperatures from 20 to 100 ° C, preferably from 50 to 80 ° C, polymerized. The customary emulsifiers, such as alkali salts of alkyl or alkylarylsulfonic acids, alkyl sulfates, fatty alcohol sulfonates, salts of higher fatty acids with 10 to 30 carbon atoms or resin soaps can be used. The sodium or potassium salts of alkyl sulfonates or fatty acids having 10 to 18 carbon atoms are preferably used. It is expedient to use the emulsifiers in amounts of 0.5 to 5% by weight, in particular 0.5 to 2% by weight, based on the monomers used in the preparation of the graft base ai). In general, the water and monomer ratio is from 2: 1 to 0.7: 1. The usual persulfates, such as potassium persulfate, are used in particular as polymerization initiators, but redox systems can also be used. The initiators are generally used in amounts of 0.1 to 1% by weight, based on the monomers used in the preparation of the graft base ai). The usual buffer substances, by means of which pH values ​​of preferably 6 to 9 are set, for example, can be used as further polymerization auxiliaries Serve sodium bicarbonate and sodium pyrophosphate; Furthermore, 0.1 to 3% by weight of a molecular weight regulator, such as mercaptans, terpinols or dimeric α-methylstyrene, can generally be used in the polymerization. β

0061The exact polymerization conditions, in particular the type, dosage and amount of the emulsifier, are chosen in detail within the above-mentioned ranges so that the latex of the diene polymer obtained aι₂) has a dso value (see above) in the range from about 100 to 750 nm, preferably in the range from 100 to 600 nm. Alternatively, an emulsion polymer with average particle sizes in the range of 60-150 nm can also be agglomerated, as described, for example, in DE-B 2427960.

0062On the graft base on) and / or aι) is a graft cover a₂) grafted on by copolymerization of

0063a ι) 50 to 95, preferably 60 to 90 and in particular 65 to 80 wt .-% of a vinyl aromatic monomer, preferably styrene or substituted styrenes of the general formula I.

0064<img file="WO9620249A1_D0001.tif" /> where R is an alkyl radical with 1 to 8 carbon atoms, a hydrogen atom or halogen and R¹ Represent alkyl radicals with 1 to 8 carbon atoms or a halogen atom and n has the value 0, 1, 2 or 3, preferably styrene, α-methylstyrene, p-methylstyrene and tert-butylstyrene, and

0065a₂₂5 to 50, preferably 10 to 40 and in particular 20 to 35% by weight of polar copolymerizable monomers selected from the group consisting of acrylonitrile, methacrylonitrile,

0066Esters of meth (acrylic acid) with 1 to

00674th Carbon atoms in the alkyl radical, maleic anhydride and their imides,

0068(Meth) acrylamide and / or vinyl alkyl ether with 1-8 C atoms in the alkyl radical or mixtures thereof

0069is obtained.

0070The graft shell a) can be produced in one or more, for example two or three, process steps, the gross composition remains unaffected.

0071The graft shell is preferably produced in emulsion, as described, for example, in DE-PS 1 260 135, DE-OS 32 27 555, DE-OS 31 49 357, DE-OS 31 49 358 and DE-OS 34 14 118 is written. Depending on the conditions selected, a certain proportion of free copolymers of styrene and acrylonitrile are formed in the graft copolymerization.

0072It is advantageous to carry out the graft copolymerization on the polymer used as the graft base ai) again in an aqueous emulsion. It can be carried out in the same system as the polymerization of the graft base, it being possible for further emulsifier and initiator to be added. These need not be identical to the emulsifiers or initiators used to prepare the graft base ai). For example, it may be expedient to use a persulfate as the initiator for the preparation of the graft base ai), but to use a redox initiator system for the polymerization of the graft shell a). For the rest, what has been said in the manufacture of the graft base ai) applies to the choice of emulsifier, initiator and polymerization aids. The monomer mixture to be grafted on can be added to the reaction mixture all at once, batchwise in several stages or preferably continuously during the polymerization. The graft copolymerization is advantageously controlled so that a degree of grafting of 10 to 60% by weight, preferably 15 to 45% by weight, results.

0073The graft copolymer (ai + a₂) generally has an average particle size of preferably 50 to 1000 nm, in particular 100 to 700 nm (dso weight average). The conditions in the production of the elastomer ai) and in the grafting are therefore preferably chosen so that particle sizes result in this range. Measures for this are known and are described, for example, in DE-PS 1 260 135 and DE-OS 28 26 925 as well as in Journal of Applied Polymer Science, Vol. 9 (1965), pp. 2929 to 2938. The particle enlargement of the latex of the elastomer can be accomplished, for example, by means of agglomeration.

0074In some cases, mixtures of several acrylic ester polymers with different particle sizes have also proven successful. Corresponding products are described in DE-OS 28 26 925 and US Pat. No. 5,196,480, to which reference is made here for further details.

0075Accordingly, preferred mixtures of acrylic ester polymers used are those in which a first polymer has a particle size dso in the range from 50 to 150 nm and a second polymer has a particle size from 200 to 700 nm, as described in the previously mentioned US Pat. No. 5,196,480 to be discribed. According to a further preferred use, mixtures of polymers are used (as described in DE-AS 11 64 080, DE-PS 19 11 882 and DE-OS 31 49 358) and polymers aι₂ used, the polymers aχ) generally having an average particle size in the range from 50 to 1000, preferably from 100 to 700 nm.

0076Some preferred graft polymers are listed below:

0077a₂/ l: 60% by weight of graft base a₂ι) from a₂n) 98% by weight of n-butyl acrylate and a₂ι₂) 2% by weight dihydrodicyclopentadienyl acrylate and 40% by weight graft a₂2) from a ₂ι) 75 wt .-% styrene and a₂₂₂) 25% by weight acrylonitrile

0078a₂/ 2: Graft base as in a₂/ l with 5 wt .-% of a graft from a₂₂ι) 12.5% ​​by weight of styrene (1st graft stage) and 40% by weight of a second graft stage from a₂2i) 75% by weight of styrene and a ₂₂) 25% by weight acrylonitrile

0079a₃/ 2: Graft base as in a₂/ l with 13% by weight of a first

0080Grafting stage made of styrene and 27% by weight of a second grafting stage made of styrene and acrylonitrile in a weight ratio of 3: 1.

0081The molding compositions according to the invention contain 1 to 90, preferably 5 to 85% by weight, particularly preferably, as component B)

008210th up to 80% by weight, based on the total weight of the molding composition, of a copolymer

0083bi) 50 to 99, preferably 55 to 90 and in particular 65 to 85% by weight of vinyl aromatic monomers, preferably styrene and / or substituted styrenes of the general formula I.

0084^•and

0085b;) 1 to 50, preferably 10 to 45 and in particular 15 to 35 wt .-% of the for a₂₂) described monomers.

0086Products of this type can be produced, for example, by the process described in DE-AS 10 01 001 and DE-AS 10 03 436. Such copolymers are also commercially available. The weight average molecular weight determined by light scattering is preferably in the range from 40,000 to 500,000, in particular from 100,000 to 250,000, which corresponds to viscosity numbers in the range from 40 to 200, preferably from 40 to 160 ml / g (measured in 0.5% by weight). % solution in dimethylformamide at 25 ° C).

0087The polymer B) can also be a mixture of different copolymers of styrene or α-methylstyrene and acrylonitrile, which differ, for example, in the acrylonitrile content or in the average molecular weight.

0088The proportion of component C) in the molding compositions, based on the sum of components A), B), C) and, if appropriate, D), is 1 to 70, preferably 2 to 50 and particularly preferably 3 to 40% by weight. Component C) is a rubber-elastic block copolymer

0089at least one block C_A- The polymerized units of a vinyl aromatic monomer and forms a so-called "hard phase", and / or

0090- a block C_B, which has polymerized diene monomers and forms a (first) rubber-elastic (soft) phase, and

0091at least one block CB / A- which has polymerized units of a vinyl aromatic monomer and a diene and forms a so-called "soft phase",

0092where the glass temperature T_G of block C_A above 25 ° C and that of block CB / A below 25 ° C and the phase volume ratio of block C_A to block C_B/_A is selected such that the proportion of the hard phase in the total block copolymer is 1-40% by weight and the proportion by weight of the diene is less than 50% by weight.

0093Detailed information on the structure and manufacture of component C) can be found below, and also in DE-OS 44 20 952, to which reference is expressly made here.

0094The soft phase (block CB / A) is obtained by random copolymerization of vinyl aromatic monomers and dienes in the presence of a polar cosolvent.

0095A block copolymer C) can be represented, for example, by one of the general formulas 1 to 11:

0096(1) (C_A-C_{B / A})_n;

0097(2) (C_A-C_BA)_n-C_A, preferably C_A-C_B/ AC_A;

0098(3⁾ Cß /_A- (C_A-CB /_A) Π? (4) X - [(C_A-C_B/ A) n) ro₊i;

0099(5) X - [(C_B/ C_A-A)_{n) m +}ι, preferably X - [- C_B/ AC_A] ;

0100(6) X -. (C_A-C_B/_A) nA] m₊i;

0101(7) X - [(C_B/_A-C_A)_n-C_B/_A] n.₊ ι; (8) Y - [(C_A-C_{B / A})_{n) πι +}ι;

0102(9) Y - [(C_B/ AC_A) n) -.ι preferably Y- [-C_BA-C_A] ₂;

0103(10) Y - [(C_A-C_BA)_n-_{A] πι +}ι;

0104(11) Y- [ ⁽C._BA-C_A⁾_n-B / A] m₊i; where C_A for the vinyl aromatic block and C_{B / A} stands for the soft phase, that is the block constructed statistically from diene and vinyl aromatic units,^*'X is the remainder of a non-functional initiator, Y is the remainder of an m-functional coupling agent and m and n are natural numbers from 1 to 10.

0105A block copolymer whose soft phase is divided into blocks is particularly preferred

0106⁽12⁾ (CB / A) ι-⁽C._B/ A> 2; ⁽13⁾ (CB / A) I- (C_B/ A) 2- (C_B/ A) 1; ⁽14⁾ (CB / A) 1- (CB / A) 2- (CB / A) 3; their vinylaromatic / diene ratio in the individual blocks C_B/ A is different or within a block within the limits (C_{B / A}) χ —► (C_{B / A})₃ changes continuously, the glass transition temperature T_G each sub-block is below 25 ° C.

0107A block copolymer that contains several blocks C_{B / A} and / or C_A with different molecular weights per molecule is also preferred, for example in combination (3) with (13) or

0108(14) .

0109Likewise, in place of a block C composed exclusively of vinyl aromatic units_A a block C_B occur, since all that matters is that a rubber-elastic block copolymer is formed. Such copolymers can have, for example, the structure (15) to (18)

0110⁽15⁾ C._B- (C_B/ A) ⁽16⁾ (CB / A) -C₃- (CB / A)

0111⁽17⁾ (C._B/ A) I-CB- (C_B/ A) 2

0112⁽18⁾ C._B- (CB / A) 1- (CB / A) 2.

0113Preferred vinyl aromatic compound for the purposes of the invention is styrene and also α-methylstyrene and vinyltoluene and

0114Mixtures of these compounds. Preferred dienes are butadiene and isoprene, also piperylene, 1-phenylbutadiene and mixtures of these compounds.

0115A particularly preferred combination of monomers is butadiene and styrene. All of the weight and volume information below relates to this combination.

0116The C_{B / A}-Block is made up of about 75-30% by weight styrene and 25-70% by weight butadiene. A soft block particularly preferably has a butadiene content between 35 and 70% and a styrene content between 65 and 30%.

0117The weight fraction of the diene in the entire block copolymer is 15-50% by weight in the case of the styrene / butadiene monomer combination, and that of the vinylaromatic component accordingly

011885 - 50% by weight. Butadiene-styrene block copolymers with a monomer composition of 25-50% by weight of diene and 75-50% by weight of vinyl aromatic compound are particularly preferred.

0119The block copolymers are prepared by anionic polymerization in a non-polar solvent with the addition of an aprotic, polar cosolvent. Aliphatic hydrocarbons such as cyclohexane or methylcyclohexane are preferably used as solvents. In particular ethers, for example tetrahydrofuran and aliphatic polyethers such as diethylene glycol dimethyl ether, and tertiary amines, for example tributylamine and pyridine, are preferred as cosolvents. The polar cosolvent is added to the non-polar solvent in a small amount, for example from 0.5 to 5% by volume. Tetrahydrofuran is particularly preferred in an amount of 0.1-0.3% by volume. Experience has shown that an amount of about 0.2% by volume is sufficient in most cases.

0120The anionic polymerization is carried out using organometallic, in particular organolithium compounds such as methyl lithium, ethyl lithium, propyllithium, n-butyllithium, sec. Butyllithium and tert. Butyllithium initiated. The organometallic compound is added as a solution in a chemically indifferent (inert) hydrocarbon in an amount of usually 0.002 to 5 mol%, based on the monomers.

0121The polymerization temperature can be between 0 and 130 ° C. The temperature range between 30 and 100 ° C. is preferred.

0122According to the invention, the volume fraction of the soft phase composed of diene and vinyl aromatic sequences in component C) is 60-99, preferably 70-95 and particularly preferably 80-90% by volume. The blocks A formed from the vinyl aromatic monomers form the hard phase, the volume fraction of which corresponds to 1-40, preferably 5-30 and particularly preferably 10-20% by volume.

01235 The soft phase of component C) usually has a glass transition temperature between -50 and + 25 ° C, preferably -50 to + 5 ° C.

0124The molecular weight of block C_A is generally 1000 to 10 200,000, preferably 3,000 to 80,000 [g / mol]. Within a molecule, C_A-Blocks have different molecular weights.

0125The molecular weight of block C_{B / A} is usually 2,000 to 250,000, preferably 5,000 to 150,000 [g / mol]. Block C too_{B / A} 15 can like block C_A assume different molecular weight values ​​within one molecule.

0126The coupling center X is formed by the reaction of the living anionic chain ends with an at least bifunctional copper

012720th planning agent. Examples of such compounds can be found in U.S. Patents 3,985,830, 3,280,084, 3,637,554 and 4,091,053. For example, epoxidized glycerides such as epoxidized linseed oil or soybean oil are preferably used; divinylbenzene is also suitable. Especially for dimerization, dichlorodial

012825th kylsilane, dialdehydes such as terephthalaldehyde and esters such as ethyl formate or benzoate are suitable.

0129The statistical block C_{B / A} can even back in block CBI_/A: -C_{B2 / A}2-C_B3_{/ A3} be divided. The statistical block preferably consists of 2 to 15 statistical subblocks, particularly preferably 3 to 10 subblocks.

0130The polymerization is carried out in several stages and, in the case of monofunctional initiation, for example with the production of the hard

013135 blocks C_A began. Some of the monomers are placed in the reactor and the polymerization is started by adding the initiator. In order to achieve a defined chain structure, it is recommended, but not essential, to run the process up to a high conversion (over 99%) before the second monomer addition

013240 he follows.

0133The sequence of the monomer addition depends on the selected block structure. In the case of monofunctional initiation, for example, the vinylaromatic compound is either initially introduced or 45 is added directly. Then diene and vinylaromatic should be added at the same time as possible. The statistical structure and the composition of block C are determined by the quantitative ratio of diene to vinylaromatic compound, the concentration and chemical structure of the Lewis base and the temperature_{B / A} certainly. According to the invention, the diene takes up a proportion by weight of 25% to 70% relative to the total mass, including vinyl aromatic compound. Then block C_A be polymerized by adding the vinyl aromatic. Instead, required polymer blocks can also be connected to one another by the coupling reaction. In the case of bifunctional initiation, the C_{ß / A}Block built, followed by the C_A-Block.

0134Further processing takes place according to the usual procedures. It is advisable to work in a stirred kettle and terminate the polymerization with an alcohol such as isopropanol, before further working up in the usual way with CO₂/ To make water slightly acidic, add the polymer with an oxidation inhibitor and a radical scavenger (commercially available products such as trisnonylphenyl phosphite (TNPP) or α-tocopherol (vitamin E) or products available under the trade name Irganox 1076 or Irganox 3052) stabilize, remove, extrude and granulate the solvent by the usual methods.

0135As component D), the thermoplastic molding compositions according to the invention can contain 0 to 300% by weight, based on the sum of A), B) and C), preferably 0 to 200% by weight, of at least one polycarbonate.

0136Suitable polycarbonates are, for example, those based on diphenols of the general formula II

0137<img file="WO9620249A1_D0002.tif" />

0138wherein A is a single bond, a Ci to C₃-Alkylene-, one

0139C.₂- to C₃Alkylidene, a C₃- to Ce-cycloalkylidene group, and -S- or -S0₂- means.

0140Preferred diphenols of the formula II are, for example, 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) propane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1, 1-bis (4-hydroxyphenyl) cyclohexane. 2,2-bis (4-hydroxyphenyl) propane and 1,1-bis (4-hydroxyphenyl) cyclohexane are particularly preferred. Both homopolycarbonates and copolycarbonates are suitable as component D); in addition to the bisphenol A homopolymer, the copolycarbonates of bisphenol A are preferred.

0141The suitable polycarbonates can be branched in a known manner, preferably by incorporating 0.05 to 2.0 mol%, based on the sum of the diphenols used, of at least trifunctional compounds, for example those having three or more than three phenolic OH groups.

0142Furthermore, the polycarbonates suitable as component D) on the aromatic units can be substituted one to three times with halogen atoms, preferably with chlorine and / or bromine. However, halogen-free compounds are particularly preferred.

0143Polycarbonates whose relative viscosities η have proven to be particularly suitable_reι from 1.10 to 1.50, in particular from 1.25 to 1.40. This corresponds to average molecular weights M._w (Weight average) from 10,000 to 200,000, preferably from 20,000 to 80,000.

0144The diphenols of the general formula II are known per se or can be prepared by known processes.

0145The polycarbonates can be produced, for example, by reacting the diphenols with phosgene by the phase interface method or with phosgene by the method in a homogeneous phase (the so-called pyridine method), the molecular weight to be adjusted in each case in a known manner by a corresponding amount of known chain terminators is achieved. (With regard to polydiorganosiloxane-containing polycarbonates, see, for example, DE-OS 33 34 782.)

0146Suitable chain terminators are, for example, phenol, p-tert-butylphenol but also long-chain alkylphenols such as 4- (1,3-tetramethyl-butyD-phenol, according to DE-OS 28 42 005 or monoalkylphenols or dialkylphenols with a total of 8 to 20 C atoms in the alkyl substituents according to DE-A 35 06 472, such as, for example, p-nonylphenyl, 3,5-di-tert-butylphenol, p-tert-octylphenol, p-dodecylphencl, 2- (3,5-dimethyl-heptyl) phenol and 4- (3,5-dimethylheptyl) phenol.

0147Other suitable polycarbonates are those based on hydroquinone or resorcinol. In addition to components A), B), C) and D), the thermoplastic molding compositions can also contain additives such as lubricants and mold release agents, pigments, dyes, flame retardants, antioxidants, light stabilizers, fibrous and powdery fillers and reinforcing agents and Antistatic agents contained in the usual amounts for these agents. Particularly in the case of the production of films from the molding compositions according to the invention, plasticizers are used with, for example copolymers with an average molecular weight of 2000 to 8000 made of 30 to 70% by weight of ethylene oxide and 70 to 30% by weight of 1,2-propylene oxide in amounts of 0.5 to 10 wt .-%, based on the sum of components A), B), C) and optionally D).

0148The molding compositions according to the invention can be produced by mixing processes known per se, for example under

0149Melting in an extruder, Banbury mixer, kneader, roller mill or calender. However, the components can also be mixed "cold" without melting and the powdery or granular mixture is only melted and homogenized during processing.

0150Moldings of all kinds, in particular foils and flat structures, can be produced from the molding compositions. The films can be produced by extrusion, rolling, calendering and other processes known to the person skilled in the art. The molding compositions according to the invention are formed by heating and / or friction alone or with the use of plasticizing or other additives to form a processable film or a sheet (plate).

0151Compared to comparable molding compositions, the thermoplastic molding compositions according to the invention have better flowability with simultaneously improved mold release properties, deep-drawing strength and not deteriorated ink adhesion and are largely free of evaporating and exuding components.

0152They are suitable for the production of foils, moldings (in particular plates) which can be further processed excellently by thermoforming and deep-drawing, as well as for the production of injection molded parts, in particular for fast processing with short cycle times. Examples

0153The following components were produced (all percentages are% by weight)

0154A: Production of components A:

0155AI: Production of a component AI:

0156Particulate graft polymer made from cross-linked poly-n-butyl acrylate (core) and styrene / acrylonitrile copolymer (shell)

0157A mixture of 98 g of n-butyl acrylate and 2 g of dihydrodicyclopentadienyl acrylate and, separately, a solution of 1 g were added to a mixture of 3 g of a polybutyl acrylate seed latex, 100 g of water and 0.2 g of potassium persulfate in the course of 4 hours at 60 ° C. Na-Ci₂-Ci₈-Paraffin sulfonate added to 50 g of water. The polymerization was then continued for 3 hours. The average particle diameter dso of the resulting latex was 430 nm with a narrow distribution of the particle size (Q = 0.1).

0158150 g of this latex were mixed with 60 g of water, 0.03 g of potassium per sulfate and 0.05 g of lauroyl peroxide, after which 20 g of styrene were added to the latex particles in the course of 3 hours at 65 ° C. and then in the course of a further 4 hours Mixture of 15 g of styrene and 5 g of acrylonitrile were grafted on. The polymer was then precipitated with a calcium chloride solution at 95 ° C., separated off, washed with water and dried in a warm air stream. The degree of grafting of the polymer was 35% and the particles had an average diameter dso of 510 nm.

0159The graft polymer was composed as follows (rounded values):

016060 % By weight of a graft core made of polybutyl acrylate, crosslinked, 20% by weight of an inner grafting stage made of styrene polymer and 20% by weight of an outer grafting stage made of styrene / acrylonitrile copolymer in the weight ratio S / AN 3: 1.

0161The seed polymer initially used was prepared by the process of EP-B 6503 (column 12, line 55, to column 13, line 22) by polymerizing n-butyl acrylate and tricyclodecenyl acrylate in aqueous emulsion and had a solids content of 40% . The average particle size mentioned in the description of component A) is the weight average of the particle sizes.

0162The mean diameter corresponds to the dso value, according to which 50% by weight of all particles have a smaller diameter and 50% by weight have a larger diameter than the diameter which corresponds to the dso value. To characterize the breadth of the particle size distribution, in addition to the dso value, the dχo and the d₉o-value specified. 10% by weight of all particles are smaller and 90% by weight larger than the dio diameter. Analogously, 90% by weight of all particles have a smaller and 10% by weight larger diameter than that which corresponds to the dgo value. The quotient Q = (dgo-dio) / dso is a measure of the width of the particle size distribution. The smaller Q, the narrower the distribution.

0163A2: Production of component A-II:

0164a) Preparation of a graft base A-II-1:

0165The preparation of the respective graft base based on acrylic ester (on, and on₂) was carried out according to the following general rule:

0166160 g of a mixture of 98% butyl acrylate and 2% dihydro-dicyclopentadienyl acrylate (DCPA) were in 1500 g of water with the addition of 5 g of the sodium salt of a Cι₂bis bis cis-paraffinsulfonic acid, 3 g potassium peroxodisulfate, 3 g sodium hydrogen carbonate and 1.5 g sodium pyrophosphate heated to 60 ° C. with stirring. 10 minutes after the polymerization reaction had started, a further 840 g of the mixture given in the table were added within 3 hours. After the monomer addition was complete, the emulsion was kept at 60 ° C. for one hour.

0167b) Preparation of a particulate graft polymer A-II:

01682100 g of the emulsion prepared according to regulation a) were mixed with 1150 g of water and 2.7 g of potassium peroxodisulfate and heated to 65 ° C. with stirring. After the reaction temperature had been reached, 560 g of styrene / acrylonitrile in a ratio of 75:25 were obtained in the course of 3 hours. After the addition had ended, the emulsion was kept at 65 ° C. for a further 2 hours. The graft polymer was removed using calcium chloride solution at 95^C.C precipitated from the emulsion, washed with water and dried in a warm air stream. A3: Production of component A-III:

0169a) The preparation of the respective graft base based on butadiene (aι₂ι, aι₂₂) was carried out according to the following rule:

0170A polybutadiene latex is prepared at 65 ° C. by polymerizing 600 g of butadiene in the presence of 6 g of tert-dodecyl mercaptan, 7 g of C 1 -C 7 -alkyl sulfonate as emulsifier, 2 g of potassium peroxodisulfate and 2 g of sodium pyrophosphate in 800 ml of water. The turnover is 98%. A latex is obtained, the average particle size of which is 100 nm. The latex obtained is added by adding '^' 25 g of an emulsion of a copolymer of 96 parts of ethyl acrylate and 4 parts of methacrylic acid amide with a solids content of 10% by weight are agglomerated, a polybutadiene latex having an average particle size of 350 nm being formed.

0171b) Preparation of a particulate graft polymer A-III:

0172After adding 400 g of water, 4 g of Na-Cι-alkyl sulfonate and 2 g of potassium peroxodisulfate to the graft base prepared according to regulation 3b, 400 g of a mixture of styrene and acrylonitrile (70:30) are added within 4 hours. The polymerization is carried out while stirring the batch at 75 ° C. The conversion based on styrene-acrylonitrile is practically quantitative. The graft rubber dispersion obtained is precipitated using magnesium sulfate solution and the separated graft copolymer is washed with distilled water and dried.

0173B: Production of component B:

0174Component B was produced by the process of continuous solution polymerization, as described in the plastics manual, ed. R. Vieweg and G. Daumiller, Vol. V "Polystyrene", Carl-Hanser-Verlag, Munich 1969. Pages 122 to 124.

0175Bl: component Bl:

0176Copolymer of styrene and acrylonitrile with 35% by weight, acrylonitrile (AN) and a viscosity number of 60 ml / g, measured as a 0.5% solution in diethylformamide according to DIN 53726 B2: component B2:

0177Copolymer of α-methylstyrene and acrylonitrile with 30 wt .-%, acrylonitrile and a viscosity number of 58 ml / g, measured as a 0.5% solution in dimethylformamide according to DIN 53726

0178B3: component B3:

0179Copolymer of styrene and acrylonitrile with 35% by weight, acrylonitrile (AN) and a viscosity number of 80 ml / g, measured as a 0.5% solution in dimethylformamide according to DIN 53726

0180C: Production of component C:

0181A simultaneous heatable and coolable 50 1 stainless steel autoclave with stirrer was prepared by flushing with nitrogen and boiling with a solution of see-butyllithium and 1, 1-diphenylethylene in cyclohexane and drying. 22.8 l of cyclohexane were introduced, after which 42 ml of sec-butyllithium and 65.8 ml of tetrahydrofuran were added. The individual stages of the polymerization are summarized in Table 1.

0182In each stage, the duration of the monomer feed was short compared to the duration of the polymerization. The specified start and end temperatures were set by heating or cooling the reactor jacket.

0183After the end of the reaction (consumption of the monomers), the polymerization was terminated by titrating to colorlessness with ethanol, and the mixture was acidified with a slight excess of acid.

0184The solution was worked up on a degassing extruder, which was provided with three degassing domes and forward and backward degassing, at 200 ° C. The granules obtained in this way were used to produce the molding composition.

0185Table 1

0186<img file="WO9620249A1_D0003.tif" /><img file="WO9620249A1_D0004.tif" />

0187The polymer obtained had the following average molar masses (in g / mol), as determined by gel permeation chromatography (calibration against polystyrene): number average M_n 119 000, viscosity agent M_v 158,000, weight average M_w 176 000.

0188The glass transition temperatures T_G were determined by DSC and were -16 ° C for the soft phase and + 75 ° C for the hard phase. The width of the glass step, a measure of the homogeneity of the phase, was 9 ° C for the soft phase and 12 ° C for the hard phase.

0189The melt volume index MVI was determined at 200 ° C. and a load of 5 kg according to DIN 53 735 and was 8.5 ml / 10 min.

0190The molding compositions according to the invention and the comparative compositions were produced on a ZSK-30 extruder from Werner and Pfleiderer at 250 ° C. with 200 rpm and 10 kg / h throughput. The product was cooled in a water bath, granulated and sprayed into tensile bars on an injection molding machine (Arburg Allrounder). The elongation at break was tested in accordance with DIN 53504

0191The flowability (MVI) was measured in accordance with DIN 53735 under the conditions given in the table.

0192The results are shown in the following table.

0193<img file="WO9620249A1_D0005.tif" />

0194Table example

0195<img file="WO9620249A1_D0006.tif" />

01961) Examples IV and 4V are comparative examples

0197The results show that the molding compositions according to the invention are distinguished by a balanced spectrum of properties.

0198<img file="WO9620249A1_D0007.tif" />