HK1042505A - Abs-moulding compounds with an improved combination of properties - Google Patents

Description

ABS moulding compositions with improved combination of properties

ABS molding compositions have been used in large amounts as thermoplastic resins for many years for the production of various moldings. The range of properties of these resins can be varied within wide limits.

ABS polymers which are characterized by a combination of good toughness (especially at low temperatures), hardness (i.e.the E-modulus), processability and surface gloss are of particular importance.

When utilizing the emulsion polymerization process, these types of products are generally prepared by using different graft rubber components in combination in a thermoplastic resin matrix.

Thus, for example, DE-OS2420357 and DE-OS2420358 describe thermoplastic molding compositions of the ABS type having high toughness, high surface gloss and easy processability, which are prepared from a combination of coarse-particled graft rubbers and fine-particled graft rubbers, where the weight ratio of styrene to acrylonitrile in the graft rubbers and in the matrix resins has to be taken to a specific value.

EP-A470229, EP-A473400 and WO91/13118 disclose a process for producing impact-resistant, high-gloss thermoplastic resins by combining a graft rubber having a low rubber content and a small particle diameter with a graft rubber having a high rubber content and a large particle diameter.

DE-OS4113326 discloses thermoplastic molding compositions having two different graft products, where the maximum gel content of each graft rubber is 30 wt.%.

For all the molding compositions described here, at least two graft rubber polymers prepared separately must be present in order to give the desired properties. This means that the conditions for the grafting reaction, the graft polymerization and the working up must be optimized separately for each grafted rubber. Furthermore, there is generally a need for at least one graft rubber component which must have a low gel content, i.e.a relatively high proportion of graft rubber polymer which is costly to produce must be used. However, in many cases, the necessary degree of reliability cannot be produced when the desired combinations of properties are adjusted.

Attempts have also been made to synthesize graft rubbers for the production of improved ABS products using mixtures of two rubber latices as the graft base.

Thus, EP-A288298 describes a process for the preparation of products using finely divided and coarsely divided rubber latices as graft base, wherein, however, only graft rubbers with a low gel content of about 40% are described. Since the thermoplastic resin thus prepared has poor thermoplastic flow properties, it cannot exhibit satisfactory processability; in addition, resin components having a high acrylonitrile content must be used, thus often resulting in discoloration of the ABS product.

EP-A745624 describes the preparation of ABS moulding compositions from a mixture of two rubber latices having a given particle size distribution range, which moulding compositions do not darken in colour when producing moulded parts having a ribbed structure. However, these products lead to unsatisfactory low-temperature toughness, in particular a poor correlation between toughness and thermoplastic processability (flow properties).

This object has therefore led to the provision of thermoplastic molding compositions of the ABS type which can be prepared using only a single graft rubber polymer, in which the abovementioned combination of high toughness, high hardness or E-modulus, high surface gloss and, in particular, good thermoplastic processability can be reliably adjusted. Furthermore, the graft rubber polymer used should have a gel content of more than 50 wt.%, preferably more than 55 wt.%.

Accordingly, the present invention provides an ABS molding composition comprising:

I) graft rubber polymers obtainable by emulsion polymerization of styrene and acrylonitrile in a weight ratio of from 90: 10 to 50: 50 in the presence of a mixture of butadiene polymer latex (A), butadiene polymer latex (B) and butadiene polymer latex (C), where styrene and/or acrylonitrile can be replaced in whole or in part by alpha-methylstyrene, methyl methacrylate or N-phenylmaleimide; average particle diameter d of the butadiene polymer latex (A)₅₀230nm, preferably from 150 to 220nm, particularly preferably from 170 to 215nm, very particularly preferably from 175 to 200nm, a gel content of from 40 to 95% by weight, preferably from 50 to 90% by weight, particularly preferably from 60 to 85% by weight, of the butadiene polymer latex (B)Average particle diameter d₅₀250 to 330nm, preferably 260 to 320nm, particularly preferably 270 to 310nm, a gel content of 35 to 75 wt.%, preferably 40 to 70 wt.%, particularly preferably 45 to 60 wt.%, and the average particle diameter d of the butadiene polymer latex (C)₅₀≧ 350nm, preferably 370 to 450nm, particularly preferably 375 to 430nm, very particularly preferably 380 to 425nm, a gel content of 60 to 90 wt.%, preferably 65 to 85 wt.%, particularly preferably 70 to 80 wt.%, each butadiene polymer latex containing 0 to 50 wt.% of a further copolymerized vinyl monomer and the weight ratio of the graft monomer used to the butadiene polymer used being 10: 90 to 60: 40, preferably 20: 80 to 50: 50, particularly preferably 25: 75 to 45: 55, and

II) at least one rubber-free copolymer of styrene and acrylonitrile in a weight ratio of 90: 10 to 50: 50, it being possible for the styrene and/or acrylonitrile to be replaced in whole or in part by alpha-methylstyrene, methyl methacrylate or N-phenylmaleimide.

In the preparation of the graft rubber polymers (I), it is preferred to use the butadiene polymer latices (a), (B) and (C) in proportions such that (a) is from 10 to 40 wt.%, preferably from 20 to 37.5 wt.%, particularly preferably from 22.5 to 35 wt.%, (B) is from 10 to 70 wt.%, preferably from 20 to 65 wt.%, particularly preferably from 30 to 60 wt.% and (C) is from 5 to 50 wt.%, preferably from 7.5 to 45 wt.%, particularly preferably from 10 to 40 wt.% (each based on the then-current solids content of the latex).

In the preparation of the graft rubber polymers (I), a further preferred group is the use of butadiene polymer latices (a), (B) and (C) in proportions such that (a) is from 10 to 40 wt.%, preferably from 20 to 37.5 wt.%, particularly preferably from 22.5 to 35 wt.%, (B) is from 30 to 70 wt.%, preferably from 35 to 65 wt.%, particularly preferably from 40 to 60 wt.%, and (C) is from 5 to 45 wt.%, preferably from 7.5 to 40 wt.%, particularly preferably from 10 to 35 wt.% (each based on the then-current solids content of the latex).

In particular, the butadiene polymer latices (A), (B) and (C) are used in such amounts that the equations B.ltoreq.A + C, B > A and B > C apply to the amount of rubber.

In general, the molding compositions according to the invention may contain from 1 to 60 parts by weight, preferably from 5 to 50 parts by weight, of (I) and from 40 to 99 parts by weight, preferably from 50 to 95 parts by weight, of (II).

The molding compositions according to the invention may furthermore comprise other rubber-free thermoplastic resins which are not synthesized from vinyl monomers, these thermoplastic resins being used in amounts of up to 500 parts by weight, preferably up to 400 parts by weight, particularly preferably up to 300 parts by weight, in each case referred to 100 parts by weight of I + II.

The butadiene polymer latices (A), (B) and (C) may be prepared by emulsion polymerization of butadiene. Such polymerization processes are known, for example, from Houben-Weyl, Methoden der Organischen Chemie, Makromolekulare Stoffe, part1, p.674(1961), Thieme Verlag Stuttgart. Up to 50 wt.%, preferably up to 30 wt.% (relative to the total amount of monomers used to prepare the butadiene polymer) of one or more monomers copolymerizable with butadiene may be utilized as comonomers.

Isoprene, chloroprene, acrylonitrile, styrene, alpha-methylstyrene, C₁-C₄-alkylstyrene, C₁-C₈Alkyl acrylates C₁-C₈Alkyl methacrylates, alkylene glycol diacrylates, alkylene glycol dimethacrylates and divinyl benzene are examples of such monomers; butadiene alone is preferably used. In the preparation of (A), (B) and (C) it is also possible, according to known methods, to prepare the finely divided butadiene polymer and then to agglomerate it in a known manner to the desired particle diameter.

A description is given of the relevant art (cf. EP-B0029613; EP-B0007810; DD-patent 144415; DE-AS 1233131; DE-AS 1258076; DE-OS 2101650; U.S. Pat. No. 5,310,9391).

Similarly, it is also possible to use the so-called seed polymerization technique, in which a finely divided butadiene polymer is first prepared and then further polymerized by reaction with butadiene-containing monomers to produce larger particles.

In principle, it is also possible to prepare the butadiene polymer latices (A), (B) and (C) by emulsifying a finely divided butadiene polymer in an aqueous medium (see Japanese patent application 55125102).

Average particle diameter d of the butadiene polymer latex (A)₅₀≦ 230nm, preferably from 150 to 220nm, particularly preferably from 170 to 215nm, very particularly preferably from 175 to 200nm, and a gel content of from 40 to 95 wt.%, preferably from 50 to 90 wt.%, particularly preferably from 60 to 85 wt.%.

Average particle diameter d of the butadiene polymer latex (B)₅₀From 250 to 330nm, preferably from 260 to 320nm, particularly preferably from 270 to 310nm, and a gel content of from 35 to 75 wt.%, preferably from 40 to 70 wt.%, particularly preferably from 45 to 60 wt.%.

Average particle diameter d of the butadiene polymer latex (C)₅₀≧ 350nm, preferably 370 to 450nm, particularly preferably 375 to 430nm, very particularly preferably 380 to 425nm, and a gel content of 60 to 90 wt.%, preferably 65 to 85 wt.%, particularly preferably 70 to 80 wt.%.

The average particle diameter d can be determined by ultracentrifuge measurement₅₀(see W.Scholtan, H.Lange: Kolloid Z.u Z.Polymer 250, p.782-796 (1972)). The specified values for the gel content are determined by the wire cage method in toluene (cf. Houben-Weyl, Methoden der Organischen Chemie; Makromolekulare Stoffe, part1, p.307(1961), Thieme Verlag Stuttgart).

In principle, the gel content of the butadiene polymer latices (A), (B) and (C) can be adjusted by known methods by using suitable reaction conditions (for example, polymerization at high reaction temperature and/or high conversion and optionally addition of crosslinking substances to give high gel content or, for example, low reaction temperature and/or termination of the polymerization before too much crosslinking has occurred and optionally addition of molecular weight regulators such as n-dodecyl mercaptan or tert-dodecyl mercaptan to give low gel content). Conventional anionic emulsifiers such as alkyl sulfates, alkyl sulfonic acids can be usedSalts, aralkyl sulphonates, soaps of saturated or unsaturated fatty acids and alkaline disproportionated or hydrogenated abietic or tall oil as emulsifiers; preference is given to using emulsifiers having carboxyl groups (e.g.C)₁₀-C₁₈Salts of fatty acids and disproportionated abietic acid).

The graft polymerization in the preparation of the graft polymer I) can be carried out by continuously adding the monomer mixture to a mixture of the butadiene polymer latices (A), (B) and (C) and carrying out the polymerization.

In this process, it is preferred to maintain a specific monomer/rubber ratio and to add the monomers to the rubber latex in a known manner.

In the presence of preferably from 50 to 85 parts by weight, particularly preferably from 60 to 80 parts by weight, each based on solids, of a mixture of butadiene polymer latices (a), (B) and (C), preferably from 15 to 50 parts by weight, particularly preferably from 20 to 40 parts by weight, of a mixture of styrene and acrylonitrile which may optionally contain up to 50 wt.% (relative to the total amount of monomers used in the graft polymerization process) of one or more comonomers is polymerized to produce the component I described in the present invention.

The monomers used in the graft polymerization are preferably mixtures of styrene and acrylonitrile in a weight ratio of 90: 10 to 50: 50, particularly preferably in a weight ratio of 65: 35 to 75: 25, it being possible for the styrene and/or acrylonitrile to be replaced in whole or in part by copolymerizable monomers, preferably alpha-methylstyrene, methyl methacrylate or N-phenylmaleimide.

Furthermore, molecular weight regulators can be used during the graft polymerization, preferably in amounts of from 0.05 to 2 wt.%, particularly preferably in amounts of from 0.1 to 1 wt.% (in each case relative to the total amount of monomers used during the graft polymerization).

For example, alkyl mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, dimeric alpha-methylstyrene and terpinolene are suitable molecular weight regulators.

Suitable initiators are inorganic and organic peroxides, e.g. H₂O₂Di-tert-butyl peroxide, cumene hydroperoxide, dicyclohexyl percarbonate, tert-butyl hydroperoxide, p-menthane hydroperoxide, azo initiators such as azobisisobutyronitrile, inorganic per salts such as ammonium, sodium or potassium persulfate, potassium perphosphate, sodium perborate and redox systems. Redox systems generally comprise an organic oxidizing agent and a reducing agent, where heavy metal ions may also be present in the reaction medium (cf. Houben-Weyl, Methoden der Organischen Chemie, vol.14/1, p. 263-297).

The polymerization temperature is from 25 to 160 ℃ and preferably from 40 to 90 ℃. Suitable emulsifiers are those already mentioned above.

For the production of component I) according to the invention, the graft polymerization can preferably be carried out as follows: by adding from 55 to 90 wt.%, preferably from 60 to 80 wt.%, particularly preferably from 65 to 75 wt.% of the monomers used for the graft polymerization of the total amount of monomers during the first half of the total monomer addition time; the remaining monomer was added during the other half of the total monomer addition time.

The rubber-free copolymers II) used are preferably copolymers of styrene and acrylonitrile in a weight ratio of 90: 10 to 50: 50, where styrene and/or acrylonitrile can be replaced in whole or in part by alpha-methylstyrene, methyl methacrylate or N-phenylmaleimide.

Particularly preferred are copolymers II) which contain copolymerized acrylonitrile units in a proportion of < 30 wt.%.

These copolymers preferably have an average molecular weight M_w20000 to 200000 and an intrinsic viscosity [. eta. ]]From 20 to 110ml/g (measured in dimethylformamide at 25 ℃).

Details of the preparation of these resins are described, for example, in DE-AS2420358 and DE-AS 2724360. The preparation of vinyl resins by bulk or solution polymerization has proven particularly advantageous. The copolymers can be added individually or in any mixture.

In addition to the use of vinyl monomers for the preparation of thermoplastic resins in the molding compositions according to the invention, it is also possible to use polycondensates, such as aromatic polycarbonates, aromatic polyester carbonates, polyesters or polyamides, as rubber-free copolymers.

Suitable thermoplastic polycarbonates and polyester carbonates are known (see, for example, DE-AS1495626, DE-OS2232877, DE-OS2703376, DE-OS2714544, DE-OS3000610, DE-OS3832396, DE-OS3077934) and can be prepared, for example, by phase-interfacial polycondensation of diphenols of the formulae (I) and (II) with carbonic acid halides, preferably phosgene, and/or aromatic dicarboxylic acid dihalides, preferably benzenedicarboxylic acid dihalides, or by homogeneous polycondensation with phosgene (the so-called pyridine process), where the molecular weight can be adjusted in a known manner using suitable amounts of known chain terminators,wherein A is a single bond, C₁-C₅Alkylene radical, C₂-C₅- (1, 1-) alkylene, C₅-C₆- (1, 1-) cycloalkylene, -O-, -S-, -SO-, -SO-₂-or-CO-, R⁵And R⁶Each independently represents a hydrogen atom, a methyl group or a halogen atom, in particular a hydrogen atom, a methyl group, chlorine or bromine, R¹And R²Each independently represents a hydrogen atom, a halogen atom, preferably chlorine or bromine, C₁-C₈Alkyl, preferably methyl or ethyl, C₅-C₆Cycloalkyl, preferably cyclohexyl, C₆-C₁₀Aryl, preferably phenyl, or C₇-C₁₂Aralkyl, preferably phenyl-C₁-C₄Alkyl, particularly preferably benzyl, m is an integer from 4 to 7, preferably 4 or 5, n is0 or 1, R³And R⁴Each X is independently selected and independently represents a hydrogen atom or C₁-C₆-alkyl and X represents a carbon atom.

Suitable diphenols of the formulae (I) and (II) are, for example, hydroquinone, resorcinol, 4 '-dihydroxydiphenyl, 2-bis (4-hydroxyphenyl) propane, 2, 4' -bis (4-hydroxyphenyl) -2-methylbutane, 2-bis (4-hydroxy-3, 5-dimethylphenyl) propane, 2-bis (4-hydroxy-3, 5-dichlorophenyl) propane, 2-bis (4-hydroxy-3, 5-dibromophenyl) propane, 1-bis (4-hydroxyphenyl) cyclohexane, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane, 1-bis (4-hydroxyphenyl) -3, 3-dimethylcyclohexane, 1-bis (4-hydroxyphenyl) -3, 3, 5, 5-tetramethylcyclohexane or 1, 1-bis (4-hydroxyphenyl) -2, 4, 4-trimethylcyclopentane.

The diphenols of the formula (I) are preferably 2, 2-bis (4-hydroxyphenyl) propane and 1, 1-bis (4-hydroxyphenyl) cyclohexane, and the phenol of the formula (II) is preferably 1, 1-bis (4-hydroxyphenyl) -3, 3, 5-trimethylcyclohexane.

Mixtures of diphenols may also be used.

Suitable chain terminators are, for example, phenol, p-tert-butylphenol, long-chain alkylphenols such as 4- (1, 3-tetramethylbutyl) phenol as described in DE-OS2842005, monoalkylphenols, dialkylphenols having a total of from 8 to 20 carbon atoms in the alkyl substituents as described in DE-OS3506472, such as p-nonylphenol, 2, 5-di-tert-butylphenol, p-tert-octylphenol, p-dodecylphenol, 2- (3, 5-dimethylheptyl) phenol and 4- (3, 5-dimethylheptyl) phenol. The amount of chain terminators required is generally 0.5 to 10 mol-%, relative to the sum of the diphenols (I) and (II).

Suitable polycarbonates or polyester carbonates may be linear or branched; the branched products are preferably obtained by admixing from 0.05 to 2.0 mol-%, relative to the total amount of diphenols used, of trifunctional or more than trifunctional compounds, such as compounds having three or more than three phenolic hydroxyl groups.

Suitable polycarbonates or polyester carbonates may be aromatic compounds containing bonded halogens, preferably bromine and/or chlorine; they are preferably halogen-free.

Their average molecular weights (M) determined by ultracentrifugation or scattered light measurement_wWeight average) of 10000 to 200000, preferably 20000 to 80000.

Suitable thermoplastic polyesters are preferably polyalkylene terephthalates, i.e.reaction products and mixtures of reaction products of aromatic dicarboxylic acids or reactive derivatives thereof, such as dimethyl esters or anhydrides, and aliphatic, cycloaliphatic or araliphatic diols.

Preferred polyalkylene terephthalates may be prepared from terephthalic acids (or reactive derivatives thereof) and aliphatic or cycloaliphatic diols having from 2 to 10 carbon atoms by known methods (Kunststoff, vol.VIII, p.695 etseq., Carl Hanser Verlag, Munich 1973).

Preferred polyalkylene terephthalates have 80 to 100 mol-%, preferably 90 to 100 mol-%, of dicarboxylic acid groups as terephthalic acid groups and 80 to 100 mol-%, preferably 90 to 100 mol-%, of diol groups as ethylene glycol and/or butanediol-1, 4 groups.

In addition to ethylene glycol or 1, 4-butanediol groups, the preferred polyalkylene terephthalates may contain 0 to 20 mol-% of groups of other aliphatic diols having 3 to 12 carbon atoms or cycloaliphatic diols having 6 to 12 carbon atoms, such as, for example, the groups of the following alcohols: 1, 3-propanediol, 2-ethyl-1, 3-propanediol, neopentyl glycol, 1, 5-pentanediol, 1, 6-hexanediol, cyclohexane-1, 4-dimethanol, 3-methyl-1, 3-pentanediol, 3-methyl-1, 6-pentanediol, 2-ethyl-1, 3-hexanediol, 2-diethyl-1, 3-propanediol, 2, 5-hexanediol, 1, 4-di (. beta. -hydroxyethoxy) benzene, 2-di (4-hydroxycyclohexyl) propane, 2, 4-dihydroxy-1, 1, 3, 3-tetramethylcyclobutane, 2-di (3-. beta. -hydroxyethoxyphenyl) propane and 2, 2-bis (4-hydroxypropoxyphenyl) propane (DE-OS2407647, 2407776, 2715932).

The polyalkylene terephthalates may be branched by incorporating small amounts of trihydric or tetrahydric alcohols or tribasic or tetrabasic carboxylic acids, such as those described in DE-OS1900270 and U.S. Pat. No. 3,692,744. Preferred branching agents are, for example, trimesic acid, trimellitic acid, trimethylolethane, trimethylolpropane and pentaerythritol. It is advisable to use not more than 1 mol-% of the branching agent relative to the acid component.

Polyalkylene terephthalates which have been prepared solely from terephthalic acid and reactive derivatives thereof (e.g.dialkyl esters) and ethylene glycol and/or butanediol-1, 4 and mixtures thereof are particularly preferred.

Copolyesters prepared from at least two of the above alcohol components are also preferred polyalkylene terephthalates; poly (ethylene glycol/1, 4-butanediol) terephthalate is a particularly preferred copolyester.

The polyalkylene terephthalates which are preferably suitable have an intrinsic viscosity of generally 0.4 to 1.5dl/g, preferably 0.5 to 1.3dl/g, particularly preferably 0.6 to 1.2dl/g, measured in phenol/o-dichlorobenzene (1: 1 parts by weight) at 25 ℃.

Suitable polyamides are the well-known homopolyamides, copolyamides and mixtures thereof. They may be partly crystalline and/or amorphous polyamides.

Suitable partially crystalline polyamides are polyamide-6, 6 and mixtures and suitable copolymers of these components. Suitable partially crystalline polyamides are furthermore those in which the acid component consists wholly or partly of terephthalic acid and/or isophthalic acid and/or suberic acid and/or sebacic acid and/or azelaic acid and/or adipic acid and/or cyclohexanedicarboxylic acid and the diamine component consists wholly or partly of m-and/or p-xylylenediamine and/or hexamethylenediamine and/or 2, 2, 4-trimethylhexamethylenediamine and/or 2, 4, 4-trimethylhexamethylenediamine and/or isophoronediamine, and their compositions are known in principle.

Mention may furthermore be made, in whole or in part, of polyamides prepared from lactams having from 7 to 12 carbon atoms in the ring, optionally using one or more of the starting components mentioned above.

Particularly preferred partially crystalline polyamides are polyamide-6, 6 and mixtures thereof. As the amorphous polyamide, a known product can be used. They are obtained by polycondensation of diamines such as ethylenediamine, hexamethylenediamine, decamethylenediamine, 2, 4-and/or 2, 4, 4-trimethylhexamethylenediamine, m-and/or p-xylylenediamine, bis (4-aminocyclohexyl) methane, bis (4-aminocyclohexyl) propane, 3-dimethyl-4, 4' -diamino-dicyclohexylmethane, 3-aminomethyl-3, 5, 5-trimethylcyclohexylamine, 2, 5-and/or 2, 6-bis (aminomethyl) norbornane and/or 1, 4-diaminomethylcyclohexane with dicarboxylic acids; dicarboxylic acids are, for example, oxalic acid, adipic acid, azelaic acid, decanedicarboxylic acid, heptadecanedicarboxylic acid, 2, 4-and/or 2, 4, 4-trimethyladipic acid, isophthalic acid and terephthalic acid.

Copolymers obtained by polycondensation of a plurality of monomers are also suitable, and in addition, copolymers prepared by adding aminocarboxylic acids such as epsilon-aminocaproic acid, omega-aminoundecanoic acid or omega-aminododecanoic acid or lactams thereof are also suitable.

Particularly suitable amorphous polyamides are those prepared from isophthalic acid, hexamethylene diamine and other diamines such as 4, 4' -diaminodicyclohexylmethane, isophoronediamine, 2, 4-and/or 2, 4, 4-trimethylhexamethylene diamine, 2, 5-and/or 2, 6-bis (aminomethyl) norbornane; or from isophthalic acid, 4' -diaminodicyclohexylmethane and epsilon-caprolactam; or from isophthalic acid, 3-dimethyl-4, 4' -diamino-dicyclohexylmethane and laurolactam; or from terephthalic acid and isomer mixtures of 2, 2, 4-and/or 2, 4, 4-trimethylhexamethylenediamine.

Instead of pure 4, 4' -diaminodicyclohexylmethane, a mixture of the positional isomers of diaminodicyclohexylmethane can also be used, said mixture of positional isomers consisting of: 70 to 99% mol-% of the 4, 4 ' -diamino isomer 1 to 30% mol-% of the 2, 4 ' -diamino isomer 0 to 2% mol-% of the 2, 2 ' -diamino isomer and optionally corresponding higher condensed diamines, which are obtained by hydrogenation of technical grade diaminodiphenylmethane. Up to 30% of the isophthalic acid may be replaced by terephthalic acid.

The relative viscosity of the polyamide is preferably from 2.0 to 5.0, particularly preferably from 2.5 to 4.0 (measured on a1 wt.% solution in m-cresol at 25 ℃).

Preferred molding compositions of the invention contain from 1 to 60 parts by weight, preferably from 5 to 50 parts by weight, of graft polymer component I) and from 40 to 99 parts by weight, preferably from 50 to 95 parts by weight, of rubber-free copolymer II).

If other rubber-free thermoplastic resins not derived from vinyl monomers are used, the amount is up to 500 parts by weight, preferably up to 400 parts by weight, particularly preferably up to 300 parts by weight (in each case referred to 100 parts by weight of I) + II)).

The molding compositions according to the invention are prepared by mixing components I) and II) in the customary mixing apparatus, preferably a multi-roll mill, a mixing extruder or an internal mixer.

The present invention therefore also provides a process for preparing the molding compositions of the invention, in which components I) and II) are mixed and then compounded and extruded at elevated temperatures, generally from 150 to 300 ℃.

During the preparation, processing, further processing and final shaping, the desired and suitable additives, such as antioxidants, UV stabilizers, peroxide decomposers, antistatics, lubricants, mold-release agents, flame retardants, fillers or reinforcing agents (glass fibers, carbon fibers, etc.) and colorants, can be added to the molding compositions according to the invention.

The final shaping can be carried out in commercially available processing equipment, including for example injection molding, sheet extrusion processing, optionally followed by thermoforming, cold forming, extrusion of pipes and profiles, and calendering processing.

In the examples below, parts are always by weight and percentages are always wt.%, unless otherwise indicated.

EXAMPLES component ABS graft Polymer 1 (according to the invention)

Prepared by radical polymerization of 15 parts by weight (based on solids) of a polymer having d₅₀An anionically emulsified polybutadiene latex with a value of 183nm and a gel content of 79 wt.%, 30 parts by weight (calculated as solids) of a polymer having d prepared by free-radical polymerization₅₀With a value of 305nm and a gel content of 55 wt.%An anionically emulsified polybutadiene latex and 15 parts by weight (based on solid matter) of a polymer having d prepared by free radical polymerization₅₀The anionically emulsified polybutadiene latex with a value of 423nm and a gel content of 78 wt.% was adjusted to a solids content of about 20 wt.% with water, and the mixture was heated to 63 ℃ and 0.5 parts by weight of potassium peroxodisulfate (dissolved in water) was added to the mixture. 40 parts by weight of a mixture of 73 wt.% styrene and 27 wt.% acrylonitrile and 0.12 parts by weight of tert-dodecyl mercaptan are then added regularly to the mixture over a period of 4 hours, in parallel with which 1 part by weight (calculated as solid) of the sodium salt of the abietic acid mixture (Dresinate731, Abieta Chemie GmbH, Gersthofen, Germany, dissolved in alkaline water) is added over a period of 4 hours. After a post-reaction time of 4 hours, after addition of about 1.0 part by weight of phenolic antioxidant, the graft latex is coagulated with a magnesium sulfate/acetic acid mixture and, after washing with water, the powder obtained is dried under vacuum at 70 ℃. ABS graft Polymer 2 (according to the invention)

17.5 parts by weight (calculated as solids) of a polymer having d prepared by free radical polymerization₅₀An anionically emulsified polybutadiene latex with a value of 183nm and a gel content of 79 wt.%, 35 parts by weight (calculated as solids) of a polymer having d prepared by free-radical polymerization₅₀An anionically emulsified polybutadiene latex with a value of 305nm and a gel content of 55 wt.% and 17.5 parts by weight (calculated as solids) of an emulsion prepared by free-radical polymerization having a d₅₀An anionically emulsified polybutadiene latex with a value of 423nm and a gel content of 78 wt.% was adjusted with water to a solids content of about 20 wt.%, and the mixture was heated to 63 ℃ and 0.4 parts by weight of potassium peroxodisulfate (dissolved in water) was added to the mixture. Then 30 parts by weight of a mixture of 73 wt.% styrene and 27 wt.% acrylonitrile and 0.1 part of tert-dodecyl mercaptan are added regularly to the mixture over a period of 4 hours. The subsequent preparation was carried out as described for the preparation of ABS graft polymer 1.ABS graft Polymer 3 (according to the invention)

17.5 parts by weight (calculated as solids) of a polymer having d prepared by free radical polymerization₅₀A value of 182nm and a gel content of 71wt.% of an anionically emulsified styrene/butadiene copolymer 10: 90, 30 parts by weight (based on solid matter) of a polymer having d prepared by free-radical polymerization₅₀An anionic emulsified polybutadiene latex with a value of 288nm and a gel content of 51 wt.% and 12.5 parts by weight (calculated as solids) of a polymer having d prepared by free-radical polymerization₅₀The anionically emulsified polybutadiene latex with a value of 410nm and a gel content of 75 wt.% was adjusted to a solids content of about 20 wt.% with water, and the mixture was heated to 63 ℃ and 0.5 parts by weight of potassium peroxodisulfate (dissolved in water) was added to the mixture. Then 40 parts by weight of a mixture of 73 wt.% styrene and 27 wt.% acrylonitrile are added regularly with 0.12 part of tert-dodecyl mercaptan over a period of 4 hours. The subsequent preparation was carried out as described for the preparation of ABS graft polymer 1.ABS graft Polymer 4 (comparison Material, not according to the invention)

The process described under "ABS graft Polymer 1" is repeated, 60 parts by weight (calculated as solids) of the polymer having d₅₀A polybutadiene latex having a value of 423nm and a gel content of 78 wt.% replaces the polybutadiene latex mixture. ABS graft Polymer 5 (comparison Material, not according to the invention)

The process described under "ABS graft Polymer 1" is repeated, 60 parts by weight (calculated as solids) of the polymer having d₅₀Polybutadiene latex having a value of 131nm and a gel content of 88 wt.% replaces the polybutadiene latex blend. Resin component 1

Obtaining M by free radical solution polymerization_wAbout 85,000, M_w/ M_n1.ltoreq.2 of a random styrene/acrylonitrile copolymer (styrene to acrylonitrile weight ratio 72: 28). Resin component 2

Obtaining M by free radical solution polymerization_wAbout 115,000, M_w/ M_n1.ltoreq.2 of a random styrene/acrylonitrile copolymer (styrene to acrylonitrile weight ratio 72: 28). Molding composition

The above-mentioned polymer components in the weight ratios shown in Table 1, 2 parts by weight of ethylenediamine distearamide and 0.1 part by weight of a silicone oil were kneaded in an internal mixer, granulated, and processed into sample rods and flat sheets (to estimate the surface area).

The following data were determined:

notched impact Strength at Room temperature according to IS0180/1A (a)_k ^RT) And notched impact strength at-40 ℃ (a)_k ^-40℃) (unit: kJ/m²)，

Ball indentation hardness (H) according to DIN53456_e) (unit: n/mm²)，

Thermoplastic flow Properties (MVI) (unit: cm) to DIN53735U³/10min), and

surface gloss (reflectometry value) at a reflection angle of 20 ° in accordance with DIN 67530.

As can be seen from the examples (see Table 2 for experimental data), the molding compositions according to the invention are distinguished by an excellent combination of very high toughness (at room temperature and low temperature), very high ball indentation hardness, easy processing and very good gloss. The variability of ABS performance is particularly high when a single graft polymer is utilized (see, e.g., increasing rubber content from 15 wt.% to 22 wt.% approximately doubles toughness when the same resin matrix is maintained).

Table 1: composition of moulding phase composition

Examples	ABS graft Polymer 1 (parts by weight)	ABS connectorDendrimer 2 (parts by weight)	ABS graft Polymer 3 (parts by weight)	ABS graft Polymer 4 (parts by weight)	ABS graft Polymer 5 (parts by weight)	Resin component 1 (parts by weight)	Resin component 2 (parts by weight)
								1	25	-	-	-	-	75	-
2	30	-	-	-	-	70	-
								3	36.7	-	-	-	-	63.3	-
4	-	21.43	-	-	-	78.57	-
								5	-	25.72	-	-	-	74.28	-
6	-	31.43	-	-	-	68.57	-
								7	-	-	30	-	-	70	-
8	36.7	-	-	-	-	-	63.3
								9	-	31.43	-	-	-	-	68.57
10	-	-	36.7	-	-	-	63.3
								11 (comparison)	-	-	-	12.5	12.5	75	-
12 (comparison)	-	-	-	15	15	70	-
								13 (comparison)	-	-	-	18.35	18.35	63.3	-
14 (comparison)	-	-	-	36.7	-	-	63.3

Table 2: experimental data on Molding compositions

Examples	Room temperature ak (kJ/m)2)	-40℃ak(kJ/m2)	Hc(N/mm2)	MVI(cm3/10min)	Degree of gloss
						1	18.3	9.0	118	40.6	94
2	24.4	12.1	108	32.4	93
						3	32.5	23.4	95	27.2	91
4	17.3	9.2	116	40.7	95
						5	24.2	12.2	105	34.4	94
6	29.7	23.0	93	28.6	93
						7	24.5	11.9	109	35.3	93
8	36.5	24.7	90	8.7	92
						9	36.2	26.1	89	8.4	92
10	36.6	23.5	91	8.9	91
						11 (comparison)	17.2	8.8	113	36.5	94
12 (comparison)	22.8	9.1	102	31.1	92
						13 (comparison)	27.3	14.6	91	23.4	91
14 (comparison)	33.1	19.7	85	8.2	92

Claims (8)

1. An ABS molding composition comprising:

   I) a graft rubber polymer which has an average particle diameter d₅₀Butadiene polymer latex (A) with a gel content of 40 to 95 wt.% and a mean particle diameter d of 230nm or less₅₀A butadiene polymer latex (B) of 250 to 330nm and a gel content of 35 to 75 wt.% and an average particle diameter d₅₀Obtained by emulsion polymerization of styrene and acrylonitrile in a weight ratio of 90: 10 to 50: 50 in the presence of a mixture of butadiene polymer latex (C) having a gel content of 60 to 90 wt.% and a particle size of 350nm or more, wherein styrene and/or acrylonitrileCan be replaced in whole or in part by alpha-methylstyrene, methyl methacrylate or N-phenylmaleimide, wherein the butadiene polymer latices each contain from 0 to 50% by weight of further copolymerized vinyl monomers, and wherein the weight ratio of the graft monomers used to the butadiene polymer used is from 10: 90 to 60: 40, and

   II) at least one rubber-free copolymer of styrene and acrylonitrile in a weight ratio of 90: 10 to 50: 50, where styrene and/or acrylonitrile can be replaced in whole or in part by alpha-methylstyrene, methyl methacrylate or N-phenylmaleimide.
2. An ABS molding composition comprising:

   I) a graft rubber polymer which can be obtained from a butadiene polymer latex (A) having an average particle diameter of 150 to 220nm and a gel content of 50 to 90 wt.%, an average particle diameter d₅₀From a mixture of a butadiene polymer latex (B) having a particle size of from 260 to 320nm and a gel content of from 40 to 70 wt.% and a butadiene polymer latex (C) having a particle size of from 370 to 450nm and a gel content of from 65 to 85 wt.%, wherein the styrene and/or the acrylonitrile can be replaced in whole or in part by alpha-methylstyrene, methyl methacrylate or N-phenylmaleimide, and from 90: 10 to 50: 50 by weight of styrene and acrylonitrile, wherein the butadiene polymer latices each contain from 0 to 50 wt.% of further copolymerized vinyl monomers, and wherein the weight ratio of the graft monomers used to the butadiene polymer used is from 20: 80 to 50: 50, and

   II) at least one rubber-free copolymer of styrene and acrylonitrile in a weight ratio of 90: 10 to 50: 50, where styrene and/or acrylonitrile can be replaced in whole or in part by alpha-methylstyrene, methyl methacrylate or N-phenylmaleimide.
3. 3. The ABS molding composition according to claim 1, wherein the butadiene polymer latices (A), (B) and (C) are used in amounts of (A) from 10 to 40 wt.%, (B) from 10 to 70 wt.% and (C) from 5 to 50 wt.% (in each case referred to the then-current solids content of the latices).
4. 4. ABS moulding composition according to any of claims 1 to 3, wherein the butadiene polymer contains, in addition to butadiene, up to 50 wt.% (relative to the total amount of monomers used in the preparation of the butadiene polymer) of comonomers selected from the group consisting of: isoprene, chloroprene, acrylonitrile, styrene, alpha-methylstyrene, C₁-C₄-alkylstyrene, C₁-C₈Alkyl acrylates C₁-C₈Alkyl methacrylates, alkylene glycol diacrylates, alkylene glycol dimethacrylates, divinyl benzene and mixtures thereof.
5. 5. The thermoplastic molding composition of any of claims 1-4, also comprising at least one resin selected from the group consisting of aromatic polycarbonates, aromatic polyester carbonates, polyesters, polyamides, and mixtures thereof.
6. 6. Process for the preparation of a molding composition as claimed in any of claims 1 to 5, wherein component I) is mixed with component II) and then compounded and extruded at elevated temperature.
7. 7. Use of the thermoplastic molding compositions as claimed in any of claims 1 to 6 for the production of molded articles.
8. 8. A molded article obtainable from the molding composition as claimed in any of claims 1 to 6.