DE2409052C3 - Thermoplastic molding compounds - Google Patents

Description

The present invention relates to thermoplastic molding compositions consisting of a polycarbonate and a Chlorostyrene copolymer rubber mixture is made up of excellent mechanical and thermal properties Have properties and good deformability.

Polycarbonates derived from bis (hydroxyaryl) alkanes are excellent thermoplastic resins mechanical, thermal and electrical properties, which as a result of these properties Material for technical devices can be used on a large scale, but because of the high melt viscosity other common thermoplastic resins in terms of moldability properties are inferior. In order to improve the deformability properties, it was proposed in US-PS 32 39 582, the polycarbonate; with a styrene and / or acrylic resin or a mixture thereof, the has better flow properties than the polycarbonate to mix.

In addition, GB-PS 9 91 442 describes a process for improving the thermal plasticity of polycarbonates by incorporating a graft polymer made from polybutadiene and a mixture of a vinyl cyanide (acrylonitrile) and a vinyl aromatic (> .s (styrene)) A polycarbonate can be made injection-moldable with such modifiers, but the impact resistance properties of the mixture leave a lot to be desired: they are lower than in the case of the unmodified polycarbonate (cf. Table I, page ₁

4). A similar modification applies to polycarbonates, wherein a graft polymer from (I) a C'opolymerisat of butadiene and styrene and (2) a mixture of alkyl acrylate and styrene is used as a modifier is described in U.S. Patent 3,1r> 2,695. The However, the product obtained suffers losses in mechanical properties, as can be seen from Table II, columns 3-4 results.

Surprisingly, it was found to be contrary to what the prior art was removable, it is possible to determine the hot water propertycii of polycarbonates without loss of mechanical strength / u, in particular an equivalent b / .w. even to achieve improved impact resistance.

The thermoplastic molding compositions according to the invention consist of

(A) a bis (hydroxyaryl) alkane derived polycarbonate and

(B) a chloromyrene copolymer rubber mixture, obtained by coagulating a mixture of

(Bl) a PfropfpolymerUallatex - the through Emulsion polymers from 20 to 70 weight share a vinyl monomer mixture, the / ur main from chlorostyrene as well as from it at least one vinyl cyanide and / or methacrylic acid ester of an alkanol with up to four carbon atoms consists, in the presence of 80 to 30 parts by weight of a conjugated diene monomer formed Kauischuk part had been made - with

(B2) a mixed polymer latex mainly consisting of having polymerizate units derived from chlorostyrene.

where in the component mixture (B) a total of 1 to 1: 5% by weight of a structure that is derived from a polymer derived from conjugated diene monomers, 43 to 94 weight percent of a chlorostyrene derived polymeric structure and 5 to 25 wt .-% of a polymer structure, which of vinyl cyanide and / or a Methacrylic acid ester of an aliphatic alcohol with a maximum of 6 carbon atoms is contained. The use of a chlorostyrene polymer has been found to be composed primarily of chlorostyrene units consists of polycarbonates with improved ductility and excellent mechanical Properties and, with a special component ratio, excellent transparency. However Such polycarbonates suffer a reduction in impact resistance, which is specific to polycarbonates is, whereby either only resin compositions with a limited component ratio can be used in practice or the resin compositions can only be used technically for limited purposes. According to the invention In contrast, polycarbonates with well-coordinated, excellent properties are used obtained when using the aforementioned chlorostyrene polymers by means of a chlorostyrene copolymer / rubber mixture replaced.

While the rubber-modified resin component according to US Pat. No. 3,239,582 by graft polymerization of a styrene or acrylic monomer a rubber component has been prepared by emulsion polymerization, chlorostyrene can be added to a

Chewable ingredients cannot be grafted on by Emulsiorispolymeri saiion. It has been found that chlorostyrene has an extraordinarily high reactivity if it is to be grafted onto a conjugated Diunkuuischuk by graft copolymerization, which is why ^c . the cycle of graft copolymerization is difficult to regulate and the graft reaction can easily get out of control. If a polycarbonal is modified with the chlorostyrene copolymer / rubber mixture obtained by this method, the desired improvement in impact strength is impossible to achieve, since only a resin composition is obtained which has unbalanced properties. However, when using the chlorosiyrene copolymer rubber mixture obtained in a certain manner according to the process, the aim of improving the properties of the polycarbonate is achieved.

The chlorostyrene copolymer / rubber mixture incorporated into the molding compositions according to the invention is produced in such a way that a mixture of a Pl'ropfpolymerisai-Laiex B1 with a copolymer latex B2, which mainly has polymer units derived from the chlorostyrene, is coagulated. The graft polymer latex B1 is produced by emulsion polymerization of 20> _s to 7 (1 Gi.v. not parts of a vinyl monomer mixture, this mainly of chlorostyrene and at least one compound selected from the group consisting of vinyl cyanide and methacrylic acid ester !! of an alkanol with up to / 11 ft C atoms consists, in the presence of 80 to 30 parts by weight of a polymer of conjugated dienes, such as butadiene or isoprene, as a rubber component. A chloroslyrole polymer, which is a suitable mixed material for polycarbonates, is therefore separately in forms, namely as a graft copolymer and mixed as a random or block copolymer after mixing the two copolymers in the form of their latiees and cases into the thermoplastic molding compositions of the invention.

Although the chlorosiyrene copolymer contains Kauischuk mixture, which is contained in the molding composition of the invention, a structure derived from a polymer comes from conjugated diene monomers, and a chlorostyrene polymer structure, but it is above In addition, to improve the dispersibility and the miscibility with the polycarbonate required that the resin also has a structure that differs from a vinyl cyanide and / or an alkyl methacrylic polymer as above. Examples of a vinyl cyanide are acrylonitrile, methacrylonitrile and the like. If Other vinyl monomers, such as a styrene derivative such as vinyl toluene or «-Methylstyrene, or may be required an alkylucrylite, such as methyl acrylate, can be added. It is necessary that in the chlorostyrene copolymer rubber mixture, the structure, which is from a Polymer derived from conjugated diene monomers, I to 15 wt .-% makes up, the structure, which differs from Derived from chlorostyrene polymer, makes up 43 to 94% by weight and the structure, which differs from the vinyl cyanide and / or alkyl methacrylate-Polymcrisat existing group of substances derived, makes up 5 to 25 percent by weight. The mixing ratio of the diene polymer to the vinyl monomer mixture is 30 to 70 parts by weight 80 to 20 parts by weight, and it is recommended that the latex contain the diene polymer rubber component contains in a relatively high proportion menee.

The amount of rubber that is introduced into the molding compound with the graft polymer latex (B1) is regulated when the latex is mixed. When the content of the rubber ingredient is greater than is necessary, the molar properties of the polycarbonate are less improved and the contribution the same to improve the impact resistance of the Molding compounds makes is less. It is therefore not recommended that the content of the rubber ingredient more than 15% by weight of the chlorostyrene copolymer rubber mixture amounts to.

The mixed polymer (H2) consists of one Random or block copolymer latex, which does not contain any graft type copolymers and by ordinary emulsion polymerization of a vinyl monomer mixture in which chlorostyrene is the main component and the rest from the other vinyl monomers mentioned above consists.

The mixing ratio between the Pf'ropfpolymcrisatlafex (BI) and the mixed polymerisallalex (B2) can be selected according to the desired composition of the polymer structures in the rubber-modified chlorostyrene polymer. For the separation of the chlorostylene copolymer rubber mixture desired as the end product from a mixture of the latex (BI) and the latex (B2), use can be made of a coagulation method such as is usually used in the production of ABS resins, whereby the latex mixture is treated with an acid or an inorganic salt containing multiple charges, which agents cause the latex to coagulate when heated.

The chlorostyrene copolymer rubber mixture obtained, which is used in the present invention, should have flow properties such that the amount which flows in the molten state through a standard nozzle 1 mm in diameter and 2 mm in length is determined at 260 ⁰ C and a load of 30 kg using a "melt flow-Kokaw Testgcrätcs, 1 to 500 (CMVS x 10-- ^1), preferably is 2 to 200 ⁽¹ x 10- CMVS).

The chlorostyrene copolymer rubber mixture is combined with the polycarbonate in any desired Ratio mixed in order to arrive at the thermoplastic molding compositions of the invention, the excellent, balanced, diverse properties depending on the mixing ratio of the individual components exhibit. For example, if the proportion of polycarbonate predominates, properties such as Deformability and the thickness safety of impact resistance are improved, whereas with a preponderance of the proportion of the chlorostyrene copolymer rubber mixture, the thermal properties and the Impact resistance of the molding compound can be improved. The composition lies between the two Quantity ranges, the properties such as deformability, thermal properties, mechanical Properties such as impact resistance, etc., are balanced and there will be accordingly made new thermoplastic molding compositions available which have technically advantageous properties show how they could not be obtained with the help of conventional methods. In particular, the disadvantages of polycarbonates in terms of deformability, thickness safety of the

IzodrKcrbschlag / ähigkcit, elasticity and the like, and likewise the disadvantages of the chlorostyrene copolymer-Kaiitschuk Mixture in terms of thermal properties, impact resistance and the like., Balanced. Usually can with the molding compositions according to the invention Polycarbonate portion contribute 90 to 20% by weight to the total amount of the molding compound.

The polycarbonates are used in the present invention, the dl / g has an intrinsic viscosity (Grenzviskosilül) of 0.4 to 1.2, preferably 0, ^r j to 1.0 dl / g, determined in Melhylenchiorid at 20 having X ', can be prepared by reacting a polycarbonate precursor, such as phosgene and a diaryl carbonal, with a bis (hydroxyaryl) alkane, and a typical example of such a polycarbonate is the poly (2,2-diphynylene propane carbonal) obtained from bisphenol Λ .

The expression "chlorostyrene" denotes a nuclear chlorinated product Derivative of styrene, usually the monochromatic derivative of slyrole. There is no restriction with respect to the substituted position in the nucleus.

Mixing the polycarbonate with the chlorostyrene copolymer-rubber mixture can be done by any commonly used device, e.g. H. mechanically using a Extruder, a Banbury mixer, a kneading roller and the like., Whereby the thermoplastic molding material dci Finding will arise.

If necessary, the molding compositions according to the invention may contain additives such as are normally used for Synthetic resins are used, for example, antioxidants, lubricants. Fillers, pigments, etc. be incorporated.

In addition, a self-extinguishing molding compound by adding a small amount of a flame retardant agent or by fresat / a part of the polycarbonate can be easily obtained by a halogenated polycarbonate.

The invention is illustrated by the following examples, all parts and percentages being expressed in parts by weight and percentages by weight, respectively, unless they are something else is expressly noted.

Example 1 and Comparison 1 a

117 parts of a polybutadiene latex (polybiitadiene fiber content 60%, average particle size 0.3 μm and gel content 85%) were diluted with 183 parts of water and treated with a mixture of 4.5 parts of acrylonitrile and 25.5 parts of chlorostyrene ( 65% o-isomer and 35% of p-isomer) was added. then 0.12 parts Kaliumpcrsulfat were added, and the mixture thus prepared a graft polymerization cmuglierten state at 60 ⁰ 7 hours, subjected to long C to obtain a latex of the graft polymer to win.

In addition, a mixture of 15 parts of acrylonitrile and 85 parts of chlorostyrene of the same composition was used as above and 0.17 parts of a modifier, tert-dodecyl mercaptan, dropwise uniformly added within 6 hours to an aqueous solution, which was obtained by dissolving 2.0 parts of sodium lauryl sulfate and 0.4 part of potassium persulfate had been prepared, the interpolymerization at one Interpolymerization temperature of 60 "C was carried out. After the addition of the mixture ended. the copolymerization was continued for 1 hour under the same conditions to win a latex of the copolymer.

The graft polymer resin was mixed with the mixed polymer resin prepared according to the above information in such a way that the solubility of the polybutadiene in the resin was 15 ^u / d. By the now following coagulation and separation of the lalcx mixture thus produced; an acrylonitrile / chloroslyrole copolymer / Kauischuk mixture was obtained which had a permissible coefficient of 85 χ 10 cm Vs at 260 ° C. under a load of 30 kg.

The mixture prepared was with the equivalent Amount of a polycarbonate mixed with an intrinsic viscosity of 0.55 in Mciliylenchlo rid at 20 "C, had and from 2,2-bis- (4-hydroxyphenyl) -prop; m, was prepared and was in a powdered state, and the mixture was in a roller at a cylinder temperature of 240 "C melt-kneaded and then extruded to the to win pellet-shaped molding compound of the invention. A lead piece was made from the pellets by injection molding produced at a cylinder temperature of 250 C. The properties of the test sample were determined. the The results obtained are shown in Table I.

In addition, a Verjilcichs purposes a Ver glcich.i resin composition in the same way as above produced, with the modification that the PoKhniadicu content in the latex blend was increased to 20%. and the results obtained with this comparison are also listed in Table I.

Table I.

(1)

(1!) (Ill) (IV) (V)

Example I.
See also la

7.5
10.0

6b 50

34

40

600
530

121
118

Annotation:

(I) I'olybuludiengchalt in the I'lodukl 1 laivniassc in per cent;
(II) llieHKenn / ahl at 260'C under a Heliisliing \ on 30 kg (χ 10 'cm Vs);

(III) Izod Keibschlag / ähigkeil. determined using of a sample uabc with a t). '' 5 mm curb (kg · im / cm);

(IV) Capacity (kg / cm ² ):

(V) Rockwell llaite (R scale)
45

As can be clearly seen from the above results, the comparative shark mass was with the higher rubber content in almost all properties. especially with regard to the deformability and the Hardness, inferior, and there were also bclriedijjcndc Results obtained when the Küulschukgehali in the rubber-modified resin was 15%.

Comparison 1 b

It became both the graft polymer latex and the Mischpolvnierisatlaicx. as in example 1 were produced, individually coagulated. The powder of the graft polymer obtained in this way was with

do the powder of the copolymer obtained in this way mixed, that the Polybuladicn-Solidgehall in the Mixture was 15%.

Using the procedure of Example 1 with the modification that the l'ol \ inet isatgc-

(, ■; mix instead of the Acrylniiril / Chlorsn rokopols merisai rubber mixture. as they are according to the I.atcx mixing methodc had been won. succeeded in application. a molding compound was produced. The l.igenschalien

an object made from the molding compound were the following:

Flow index (260 ° C under a load of 30 kg):

54 χ 10- ³ CMVS;

Notched Izod Impact Strength (using a Test rod with a 6.35 mm notch):

7 kg · cm / cm;
Tear strength:

570 kg / cm ² .

Example 2

Test pieces of the molding compositions were produced by the method of Example 1, the Mixing ratio between the polycarbonate and the acrylonitrile / chlorostyrene copolymer-rubber mixture was changed. The properties of the test pieces are summarized in Table II.

Table 11 (B) (M) (111) (IV) (Vl) 0 20th 10 680 130 20th 44 36 670 118 Mixing ratio (%) 40 60 37 630 111 (A) 70 72 18th 540 101 100 100 85 9 440 93 80 60 30th 0

Annotation:

(A) polycarbonal;

(B) kmiischiik-mocliii / iertcs acrylonil / chlorostyrene resin;

(II) lliell-Kennzuhl at 2bO'C under a load of 30 kg (χ ΙΟ ι cm Vs);

(III) Izocl-Keibschlag / .üliigkeii. determined using a test rod with a b.35mm notch (k): · cm / cm);

(IV) ReilircMigkeii (kg / cm ·);

(Vl) with / cvei'fornuingsicnipi'i'aiiir under a llelasuing of IH.b kg / cm- 'without annealing ("C).

At the same time, the properties of the comparison samples, which consist of each mass alone, are in the Table. The remarkable improvement in impact resistance proves that the miscibility is good was. In addition, the table clearly shows that the molding compositions of the invention have excellent, have balanced properties.

ß c i s ρ i c I 3

A mixture of 20 parts of acrylonitrile. 50 parts of chloroslyrole (65% o-isomcres and 35% p-isomcres), 30 parts of methylstyrene and 0.30 parts of tert-dodecylmcrcuptnn were added dropwise uniformly over a period of 6 hours to an aqueous solution, which was obtained by dissolving 2, 0 part of sodium luuryl sulfut and 0.4 part of kwliumpcrsulful in 200 parts of water had been prepared, the copolymerization of the system being carried out at a copolymerization temperature of 60 "C. After the addition of the mixture was complete, the copolymerization was a further 2 hours below the the same conditions as above continued in order to obtain a latex of the copolymer.

The mixed polymeric crystallite latex thus prepared became mn the graft polymer iMilltitex. as in Example I.

was used, mixed so that the polybutadiene content in the latex mixture was 7%. Thereafter was prepared in the same manner as in Example 1, a rubber-modified acrylonitrile / Chlorslyrol resin composition whose Flicßkennzahl 8 χ 10- ³ cm ³ / s, determined at 26O ¹¹ C under a load of 30 kg, was.

The copolymer-rubber mixture was then mixed well with the polycarbonal, which had an intrinsic viscosity of 0.7, determined in methylene chloride at 2O ⁰ C, in a mixing ratio of 1: 1 as in Example 1. The properties of a The object produced from this molding compound showed the following measured values:

Notched Izod Impact Strength (using a 6.35mm notch test stick):

25 kg · cm / cm;
Tear strength wedge:
680 kg / cm ² ;

Heat deformation temperature (load 18.6 kg / cm ² , without annealing):
HO ¹⁵ C.

Example 4

After diluting 83 parts of the polybutadiene latex from Example 1 with 197 parts of water, half the amount of the mixture of 7.5 parts of acrylonitrile, 42.5 parts of chlorostyrene (55% o-isomer, 2% m-isomer and 43% p- lsomcres) and 0.05 parts lert.-dodecyl mercaptan to the diluted solution was added and it was brought by the addition of 0.20 part of potassium persulfate at 60 ⁰ C, the graft poly mcrisations reaction for starting. One hour after the initiation of the reaction, the remaining half of the acrylonitrile / chlorostyrene mixture was added dropwise uniformly to the reaction system over 3 hours, and thereafter the reaction was continued for further 3 hours at the same temperature to complete the graft polymerization. An acrylonitrile / chlorostyrene mixed polymer latex was also prepared in the same manner as in Example I, with the modification that the isomeric composition of the chlorostyrene used differed somewhat from the composition given above.

The graft polymer latex and the mixed polymer latex prepared as above were combined with one another mixed so that the polybuidium content in the latex mixture was 10%, and then that

The product is coagulated by treating it with a coagulant under heating in order to obtain an acrylic / chlorostyrene copolymer-rubber mixture which has a flow index of 95 χ 10- ^J cniVs, determined at 260 "C under a load of 30 kg, exhibited.

5 <j This mixture was made with the polycarbonate as in Example 1 was mixed in a mixing ratio of 1: 1 in the powdered state, and then the Mixture kneaded through by means of an extruder at a cylinder size of 240 "C and pcllctisicrt

(, 0 the pellets of the resin mass produced in this way became a Molded articles by transfer molding at a cylinder temperature of 240 "C and the temperature was 40" C lower than when the Polyeurobontite. The properties of the product are in

ds Table III compiled together with the properties of a comparative sample prepared according to comparative test 4a below had been.

709 833/210

Comparative experiment 'ta

A resin was found that had the same composition as the acrylonitrile / chlorostyrene copolymer rubber mixture in Example 4 by an emulsion grafting method under the following conditions and a comparative resin composition was also prepared by the same procedure as in Example 4 manufactured with the modification that the resin prepared above as a rubber-inodified resin has been used. The properties of a molded article of the resin composition are also shown in Table III cited.

The copolymer-rubber mixture used in the comparative experiment was prepared as follows: After 16.6 parts of the polybutadiene latex from Example 1 had been diluted with 193 parts of water, 2.0 parts of sodium lauryl sulfate as an emulsifier and 0.36 part of potassium persulfate were added , and the mixture was heated ^{to 60 ° C.} To this, a mixture of 13.5 parts of acrylonitrile, 76.5 parts of chlorostyrene and 0.15 part of lert-dodecyl mercaptan was added dropwise uniformly over 5 hours to carry out the grafting reaction. After the addition of the mixture was completed, the reaction was further continued for 2 hours at the same temperature as above to complete the grafting reaction. The acrylonitrile / Chlorütyrolcopolymerisat-rubber blend was prepared by treating the latex thus prepared with a coagulant having a flow index of about 60 χ ¹ 10-- CMVS determined at 2 (i0 ° C under a load of 30 kg had recovered.

Table III (I) (II) (III) (IV) 5
5 82
85 32
14th 640
650 Example 4
Comparison 4a

Annotation:

(I) Polyhutiulieiigehiili in the product-1 iniv.mnss in percent;

(II)! '' LiuD-Kennznhl, determined at 2b () "C under a Hein stunt; from JO kg (x IO 'em ¹ As);

(IM) I / <> (I-Kui'bsehlii |; / Ithigkcii, determined using a l'robesuibes with a b.iVintn-Ketbe (kg · cm / un); (IV) Wedge strength (kg / i'in>),

From the above poor results it can be seen that the molding compound produced in Example 4 had a higher Izod notch additive value than the molding compound which had been produced in comparative experiment Ib, and that the acrylic / chlorostyrene copolymer rubber mixture according to the invention produced could produce beneficial results.

Example 5

NÜH dilution of 67 parts of a Polybutu · dicnlntcx of Example I with 203 parts of water was half the amount of a mixture ims 9.0 parts of acrylonitrile, 51 parts of chlorostyrene (65 ⁴ · Vo o isomer and 35% p-lsomcres), and 0, 06 parts lcrt.-Dodccylmcrcap given · lan to the diluted solution, and the mixture was crwürmt to 60 C ^u. Duntich was caused a graft polymerization reaction to start by adding 0.24 part of sulfate sulfate to the mixture. One hour after the initiation of the reaction, the remaining half of the aforementioned acrylonitrile / chlorostyrene mixture was added dropwise uniformly, and after the addition of the mixture was completed, the reaction was continued for another 3 hours at the same temperature to complete the graft polymerization bring to.
On the other hand, it became a mixture of 10 parts

ίο Acrylonitrile, 90 parts of chlorostyrene and 0.15 part of tert-dodecyl mercaptan added dropwise uniformly within 6 hours to an aqueous solution prepared by dissolving 2.0 parts of sodium alkylbenzenesulfonate and 0.4 part of potassium persulfate in 200 parts of water was, wherein the copolymerization was carried out ^{at a temperature of 6O 0 C.} The copolymerization was then continued for a further hour under the same conditions in order to obtain a latex of the copolymer.

The graft polymer latex and the mixed polymer latex were mixed with one another in such a way that the polybutadiene solids content in the latex mixture was 10%, and an acrylonitrile / chlorostyral copolymer rubber mixture with a flow index of 55 χ 10- was then formed by coagulating and separating the latex mixture. CMVs ^3, determined at 260 ⁰ C under a load of 30 kg was prepared.

A molding compound was then prepared in the same manner as in Example 1. The upcoming applied polycarbonate had a green Imolare viscosity of 0.6, determined in Metbylenchlorid at 2O ¹¹ C on. The properties of a molded article made from the molding compound were as follows:

I / O notch impact strength (determined using a test rod with a 6.35 nim notch):

30 kg · cm / cm;
Tear strength:

620 kg / cm ² ;

Wire deformation temperature (load IH, b kg / cm 'without annealing):
107 "C.

Example 6

In the same manner as in Example 1 came with animal except that Meihylmethacrylal imslelle before acrylonitrile used, was a molding composition comprising polycarbonate and a Methylmeth-

ju-uu ylal / ChlovstyiOlcapolymeristti-Kautsehuk-Mi research, which had a FlielJ-Kcnnzahl of 110 χ IO ^{J J} cm / s measured at 26O ⁰ C under a load of 30 kg was prepared. The properties of a molded article produced from the molding compound were di (

_5S following:

· Flow index (determined at 260 ⁰ C under elnei load of 30 kg);

80 χ 10- 'cmVs;

ho lüöd notched impact strength (determined using a test rod with a 6.35 mm notch):

28 kg · cm / cm; Tear strength:

580 kg / cm *:

O ₅ exhaustion temperature (load 18.6 kg / cm · ¹ without annealing): 103 "C.

Claims (2)

Patent claims: ! .Thermoplastic molding compounds, consisting of (A) one derived from bis (hydruxyaryl) alkane Polycarbonate and (B) a Chlorstyroicopolymerisai-Kaulschuk Mixture obtained by coagulating a mixture of (Bl) a Pfropipolymensatlalex - the through Emulsion polymerization from 20 to 70 percent by weight a Vinylmonomereu-Gemisehes, the / ur main from chlorostyrene as well as from at least one vinyl cyanide and / or methacrylic acid ester of an alkanol with up to / u b carbon atoms consists, in the presence of 80 to 30 parts by weight a rubber component formed from conjugated diene monomers had been - with (B2) a mixed polymer latex, which mainly has polymcrisal units derived from chloroslyrole. where in the component mixture (B) a total of I to 1. ¹ JGeW .- "/) of a structure which originates from a polymer of conjugated diene monomers. 4J to s) 4% by weight of a polymeric structure derived from chloroslyrole and 5 to 25% by weight of a polymer structure derived from vinyl cyanide and / or a methacrylic acid ester of an aliphatic alcohol with a maximum of b carbon atoms. 2. Thermoplastic molding compositions according to claim I, characterized in that part of the Polycarbonate (A) by a halogenated polycarbonate is replaced. and / or that they additionally contain a flame retardant agent. 35