MXPA96006474A - Composite of molding termoplast - Google Patents

Abstract

The present invention relates to: Thermoplastic molding compound comprising as essential components. A) from 10 to 100% by weight of copolymers of the monomers of the general formulas I and I: wherein R1 is H or alkyl of 1 to 22 carbon atoms, R2 is H or alkyl of 1 to 22 carbon atoms, R3 is H alkyl from 1 to 4 carbon atoms, a is 0, 1, 2, 3, 4 or 5, and b is 0, 1, 2, 3, 4, or 5, B) from 0, to 3000 ppm, based on the weight of the component A), of the compounds of the general formula I, C) from 0, to 500 ppm, based on the weight of the component A), of the compounds of the general formula II, D) from 0, up to 90%, by weight , based on the total weight of the molding compound, of polymers other than A), and E) from 0 to 50% by weight, based on the total weight of the molding compound, of additives and processing aids

Description

"COMPOSED OF THERMOPLASTIC MOLDING" DESCRIPTION The present invention relates to thermoplastic molding compounds comprising as essential components: A) from 10 percent to 100 percent by weight of copolymers of the monomers of the general formulas I and II wherein R] _ is H or alkyl of 1 to 22 carbon atoms, R 2 is H or alkyl of 1 to 22 carbon atoms, R 3 is H or alkyl of 1 to 4 carbon atoms, A is 0, 1, 2 , 3, 4 or 5, and B is 0, 1, 2, 3, 4 or 5, B) from 0 to 3,000 parts per million, based on the weight of component A, of the compounds of general formula I, C ) from 0 to 500 parts per million, based on the weight of component A, of the compounds of general formula II, D) from 0 to 90 weight percent, based on the total weight of the molding compound, of polymers which not be A), and E) from 0 to 50 weight percent, based on the weight of the molding compound, of additives and processing aids.

Molded thermoplastics are hard and rigid at room temperature. At higher temperatures, however, the utility of thermoplastics is limited by the glass transition temperature or by the melting temperature in the case of partially crystalline thermoplastics. This also applies to atactic polystyrene, whose glass transition temperature is 101 ° C and which does not crystallize due to the irregular orientation of the phenyl rings. It has recently been possible, by means of metallocene catalysis, to produce a syndiotactic polystyrene whose crystalline regions have a melting temperature of 275 ° C (e.g., Patents Nos. EP-A-210 615, EP-A-535 582, EP-A-312 976 and EP-A-318 833) Syndiotactic polystyrene, however, has several disadvantages. For example, the processing scale for the production of molded parts is relatively small since the product has to be heated to a temperature of or above the melting temperature on the one hand, but which will decompose at more than 310 ° C, other part. The consequence is that the product easily depolymerizes back into the styrene monomer during processing. In addition, the product is critalized in different ways that have a significant effect on the functional characteristics of the molded part. Finally, only the crystalline regions have a high melting temperature; the amorphous regions will still have a vitreous state transition temperature of 101 ° C as above. The polymerization of 1,1-diphenylethylene with styrene is known and described in Bulletin Chem. Soc.

Jap. 40 (1967), 2569 and in J. Polymer Sci., Part B, 8 (1970), 499. However, the method described in these publications has the disadvantage that the polymerization proceeds extremely slowly and the conversion is incomplete if higher softening temperatures are to be obtained. The diphenylethylene monomer remaining in the copolymer lowers its vitreous state transition temperature and, therefore, renders it unusable for commercial purposes. It is an object of the present invention to provide thermoplastic molding compounds which are free of the disadvantages described above, which have a glass transition temperature of at least 130 ° C and which have a residual monomer content of < 4000 parts per million. We have found that this object is achieved by thermoplastic molding compounds according to claim 1. Preferred molding compounds of this invention are disclosed in the subclaims. Component A of the thermoplastic molding compounds of this invention comprises from 10 percent to 100 percent, preferably from 40 percent to 100 percent and especially from 60 percent to 100 percent by weight, based on the proportion of the polymer components, of a copolymer having units deriving from monomers I and II.

The monomers of the general formula I are 1,1-diphenylethylene and its derivatives, wherein the aromatic rings are substituted by alkyl having up to 22 carbon atoms. Preferred alkyl substituents are alkyl groups having from 1 to 4 carbon atoms, such as methyl, ethyl, isopropyl, n-propyl, n-butyl, isobutyl and tertiary butyl to name a few. However, the unsubstituted 1, 1-diphenylethylene itself is particularly preferred. The monomers of the general formula II are styrene and its derivatives, wherein there is a substitution by alkyl having from 1 to 4 carbon atoms in the alpha position or in the aromatic ring. Preferred alkyl groups are those mentioned above as preferred for the monomers of the formula I; the unsubstituted styrene itself is particularly preferred. The molar ratio of the units derived from monomer 1 to the units derived from monomer II, is generally within the range of 1: 1 to 1:25, preferably within the range of 1: 1.05 to 1:15, particularly preferably within the scale of 1: 1.1 to 1:10. Since the monomers of the formula I are generally not homopolymerized, products having molar ratios of more than 1: 1 can not be readily obtained. The novel process for producing component A) of the molding compounds of this invention comprises providing the monomers of formula I as an initial charge and dosing in the monomers of formula II during adhesion according to a gradient method in such a manner that as the reaction proceeds, the amount of monomer II added per unit time is essentially reduced according to the amount of monomer I still present. In this way, in order to carry out the reaction, the monomer ratio remains approximately constant throughout the polymerization. In order to control the addition gradient, it is advantageously possible to use the change in the refractive index which is a function of the monomer ratio. A further possibility is to determine the ratio of the monomer as a function of the conversion in a number of preliminary experiments in order to obtain an appropriate calibration curve. The mentioned monomers are advantageously reacted in an inert solvent. The term "inert" in this context means that the solvent does not react with the organometallic initiator usually used to initiate the reaction. Therefore, both aliphatic and aromatic hydrocarbons are generally appropriate. Examples of suitable solvents include cyclohexane, methylcyclohexane, benzene, toluene, ethylbenzene, and xylene. Finally, it is also possible to use hydrocarbons in which the copolymer formed in the course of the reaction is not soluble. In this case, a polymerization by precipitation or by means of a dispersant, a dispersion polymerization can be carried out instead of the solution polymerization. Examples of suitable reaction media, such as process variants, include butane, pentane, n-hexane, isopentane, heptane, octane and isooctane. The polymerization is usually initiated by means of organometallic compounds; that is, the polymerization is an anionic polymerization. Preference is given to alkali metal compounds, especially lithium. Examples of initiators are methyl lithium, ethyl lithium, propyl lithium, n-butyl lithium, secondary butyl lithium and tertiary butyl lithium. The organometallic compound is usually added with a solution in a chemically inert hydrocarbon. The rate of addition depends on the molecular weight desired for the polymer, but generally falls within the range of 0.002 percent to 5 mole percent, based on the monomers.

Small amounts of the polar aprotic solvents can be added to have higher polymerization rates. Examples of suitable solvents are diethyl ether, diisopropyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether and, especially, tetrahydrofuran. The polar cosolvent is usually added to the apolar solvent in a small amount of about 0.5 percent to 5 percent by volume in this process variable. Specific preference is given to THF in an amount of 0.1 to 0.3 percent by volume. Pure THF has a detrimental influence on the reaction parameters so that the polymer comprises high residual levels of monomers of formula I. The polymerization temperature can be within the range of 0 ° C to 130 ° C. Preference is given to temperatures of 50 ° C to 90 ° C. In general, the polymerization is carried out under isothermal conditions, that is, with a constant polymerization temperature. However, the temperature can also be allowed to rise within the range of 0 ° C to 130 ° C, preferably 30 ° C to 120 ° C. It is particularly advantageous to carry out the initial part of the polymerization under isothermal conditions in order to allow the temperature to rise adiabatically until the end of the polymerization, ie, low monomer concentrations, so that the times of the polymerization can be kept short. polymerization. Reaction times generally fall within the range of 0.1 to 24, preferably from 0.5 to 12, particularly preferably from 1 to 10 hours. Component B) of the thermoplastic molding compounds of this invention comprises from 0 to 3000, preferably from 0 to 2000, particularly preferably from 100 to 1000, parts per million of monomers of the formula I. Preferably, the monomers have the same formula as the monomers incorporated in the copolymer during the course of the polymerization. Component C) of the thermoplastic molding compounds of this invention comprise from 0 to 500, preferably from 0 to 200, in particular from 20 to 100 parts per million of the monomers of the formula II. These monomers preferably have the same chemical formula as the monomers used to prepare component A). The amounts of components B) and C) are based on the weight of component A in the thermoplastic molding compounds. Component D) of the thermoplastic molding compounds of this invention comprise from 0 to 90 percent, preferably up to 60 percent, especially up to 30 percent by weight based on the total weight of the molding compound, of additional components that are not copolymer A). In principle, no specific restriction applies to the structure of these additional polymeric components; however, preference is given to polymers having at least some degree of compatibility with component A), since the mechanical properties are generally not otherwise satisfactory. The preferred polymers are styrene polymers, such as crystalline high impact polystyrene or the polyphenylene ether addition polymers with or without a mixture of styrene polymers. In addition, the thermoplastic molding compounds of this invention can further include as component E) up to 50 weight percent based on the total weight of the thermoplastic molding compound of additional additives and processing aids. These additives are known to those skilled in the art and are described in the literature so that there is no need to mention details in the present. Examples are fibrous or particulate fillers or fillers, stabilizers against heat and ultraviolet light, mold release agents and lubricants. In a similar manner, of course, the pigmentation of the molding compounds of this invention is possible. A further embodiment of the present invention takes the form of block copolymers with blocks A and B of the following general structures: (AB) n, ABA, BAB, X [(AB) n] m, X [(BA) n] m, X (ABA) m or X (BAB) m, wherein A is a block of a monomer copolymer of the general formulas I and II, B is a block of monomers of the general formula II, X is the radical of a m-functional coupling agent, n is an integer from 1 to 5 and m is an integer from 2 to 20. The coupling agent X reacts with the ends of the living anionic chain after polymerization to form the structures described above. Examples of suitable coupling agents can be found in U.S. Patent Nos. 3,985,830, 3,280,084, 3637,554 and 4,091,053. The merely illustrative examples are the epoxidized glycerides, such as epoxidized linseed oil or soy bean oil; Divinylbenzene is also appropriate. If the living anionic end is located in block B then the coupling preferably is carried out with the compounds containing epoxy and / or ester groups, however, if block A forms the active end, it is preferred to use divinylbenzene for The coupling. Block transitions can be sharp or tapered. A tapered transition refers to a piece of the molecular chain wherein the monomers of block A form a random distribution with the monomers of block B. The desired molecular weight for the control blocks through the ratio of the initiator to the monomer. The block copolymers disclosed with the polymer block derived from the monomer of the mixture of the general formula II with crystalline polystyrene or high impact strength to form polymer blends having a high softening temperature and good mechanical properties. In addition, the block copolymers of this invention can be used as is. They are particularly suitable for food contact applications since their residual monomer content is extremely low, advantageously less than 3,000 parts per million, especially less than 2,000 parts per million for the monomers of the formula I and less than 500 parts per million preferably less than 200 parts per million for the monomers of formula II.

Examples Purification of 1,1-diphenylethylene (DPE) Crude DPE (from Aldrich or from the reaction of phenyl agnesium bromide with acetophenone, acetylation with acetic anhydride and thermal removal of acetic acid) is distilled through a column having at least 50 theoretical plates (spinning band column) a Sulzer packed column for larger quantities) to a purity of 99.8 percent. The slightly yellow distillate is usually filtered through a 20 cm Alox column (Woelm alumina for chromatography, anhydride), titrated with secondary butyl lithium of 1.5N concentration to a deep red color and distilled through of a simple still head under reduced pressure (1 mbar). The resulting product is completely colorless and can be used directly in the anionic polymerization.

Polymerization The solutions with living anions, in general, were handled under ultrapure nitrogen. The solvents were dried through anhydrous alumina.

In the examples which will be given below, S represents styrene, DPE represents 1,1-ethylethylene and the percentages are by weight, unless otherwise stated.

Example 1 Preparation of the random S / DPE copolymer with a molar ratio of S-DPE of 2: 1; simultaneous addition of S, DPE and cyclohexane. A 2 liter glass reactor equipped with a jacket for cooling and heating and a horseshoe agitator was made inert for several hours with a reflux solution of DPE / secondary butyl lithium in cyclohexane. After the removal of the cleaning solution, 100 milliliters of cyclohexane, 100 milliliters of a mixture of 264.24 milliliters (270.38 grams, 1.5 moles) and DPE and 344.37 milliliters (312.45 grams, 3.0) were introduced as the initial charge at 25 ° C. moles) of styrene and also 9.71 milliliters of a 0.5 M secondary butyl lithium solution in cyclohexane. The mixture immediately became red. The reactor content was thermostatted at 70 ° C by means of the heating jacket, the heating greatly darkened the color of the solution. The remaining 508.6 milliliters of the S-DPE mixture were dosed through 40 minutes by an injection pump at a constant rate. At the same time, 500 milliliters of cyclohexane were introduced throughout the same period. Seven minutes after completion of the addition, an additional 249 milliliters of cyclohexane (50 percent polymer concentration) was added. The viscosity increased distinctly during the polymerization. After an additional 15-minute post-reaction time, the content was titrated with ethanol to a colorless endpoint, the polymer was precipitated in ethanol by the dropwise addition of a polymer solution, filtered and washed repeatedly with ethanol in boiling, and the resulting white powder was dried at a temperature of 180 ° C under reduced pressure (1 mbar) for 2 hours. Yield: 580 grams (99.5 percent); volatile materials: 0.3 percent; styrene content (FTIR): 54.5 percent (theoretical 53.6 percent); DPE content (FTIR): 45.1 percent (46.4 percent (theoretical), monomeric DPE level (component B) 2,180 parts per million, styrene level (component C) 384 parts per million, Tg (DSC): 155 ° C, vitreous state transition temperature scale: 9 ° C, molar masses (GPC, polystyrene calibration, gram / mol), Mn 105,000, molecular weight 126,000, M (maximum) 119,000.

Example 2 Preparation of a random S / DPE copolymer with a molar ratio of S-DPE of 2: 1; initial charge of DPE and S-addition cyclohexane. The reactor prepared as in Example 1 was charged at 25 ° C with 749 milliliters of cyclohexane, 264.24 milliliters (270.38 grams, 1.5 moles) of DPE and 9.71 milliliters of a solution of butyl. - secondary liter of 0.5 M and thermostated at 70 ° C. The first 300 milliliters of styrene dosed through 5 minutes, the next 20 milliliters through 10 minutes and the remaining 24.37 milliliters of styrene through 15 minutes. After a 15 minute post-reaction time, the batch was treated as described in Example 1. Yield: 582 grams (99.8 percent); Volatile: 0.1 percent; Styrene content (FTIR): 54.1 percent (theoretical 53.6 percent); DPE content (FTIR): 45.5 percent (theoretical 46.4 percent); DPE monomer (component B): 350 parts per million, styrene monomer (component C): 25 parts per million; Tg (DSC): 156 ° C; vitreous state transition stage scale: 12 ° C: molar masses (GPC, polystyrene calibration, gram / mol): Mn 107,000, Mw 128,000, M (maximum) 120,000.

Example 3 Preparation of a random S / DPE copolymer with a molar ratio of S-DPE of 1.1: 1; initial charge of DPE and addition of S and cyclohexane. The reactor prepared as in Example 1 was charged at 25 ° C with 264.24 milliliters (270.38 grams, 1.5 moles) of DPE and 7.37 milliliters of a secondary butyl-lithium solution of 0.5 M and thermostatted at 70 ° C. 189.4 milliliters (171.85 grams, 1.65 moles) of styrene were premixed with 810.6 milliliters of cyclohexane. The mixture was dosed through 180 minutes by means of an injection pump reducing the rate of addition according to the gradient method. The amounts added were: from 0 to 30 minutes 507.94 milliliters; from 30 to 60 minutes 253.97 milliliters; from 60 to 90 minutes 126.98 milliliters; 90 to 120 minutes 63.49 milliliters; from 120 to 150 minutes 31.75 milliliters; 150 to 180 minutes 15.87 milliliters. After a 15 minute post-reaction time, the batch was treated as described in Example 1. Yield: 441 grams (99.7 percent); Volatile: 0.1 percent; Styrene content (FTIR): 39.2 percent (38.9 percent theoretical) DPE content (FTIR): 60.9 percent (61.1 percent theoretical); DPE monomer (component B): 560 parts per million: styrene monomer (component C): 12 parts per million; Tg (DSC): 173 ° C, vitreous state transition stage scale: 13 ° C; molar masses (GPC, polystyrene calibration, gram / mol): Mn 104,000, Mw 124,000, M (maximum) 116,000.

Example 4 Preparation of a diblock copolymer of S / DPE-S with a molar ratio of S-DPE for the S / DPE block of 1.1: 1. The reactor prepared as in Example 1 was charged at 25 ° C with 264.24 milliliters (270.38 grams, 1.5 moles) of DPE and 14.74 milliliters of a secondary butyl-lithium solution of 0.5M and thermostatted at 70 ° C. 189.4 milliliters (171.85 grams, 1.65 moles) of styrene were premixed with 810.6 milliliters of cyclohexane. The mixture was dosed through 90 minutes by means of an injection pump reducing the rate of addition in the form of a gradient as described in Example 3. After a 15-minute post-reaction time, 442.2 grams were dosed. of styrene and 400 milliliters of cyclohexane over 15 minutes and the batch was treated as described in Example 1 after an additional 15 minutes. Yield: 884 grams (99.9 percent); Volatile: 0.05 percent; Styrene content (FTIR): 69.4 percent (theoretical 69.4 percent); DPE content (FTIR): 30.5 percent (30.6 percent theoretical); DPEE monomer (component B): 72 parts per million; styrene monomer: 7 parts per million; Tg (DSC, two stages of transition of vitreous state equally high): 171 ° C; vitreous state transition scale width: 15 ° C; 105 ° C; vitreous state transition stage width: 16 ° C.

Molar masses (GPC, polystyrene calibration, gram / mol): Mn 115,000, Mw 123,000 M (maximum) 119,000.

Example 5 Preparation of S / DPE-S-S / DPE ethylbloqueue copolymer with a molar ratio of S-DPE for S / DPE blocks of 1.1: 1 and coupling with ethyl formate. The reactor prepared as in Example 1 was charged at 25 ° C with 264.24 milliliters (270.38 grams, 1.5 moles) of DPE and 29.48 milliliters of a secondary butyl lithium solution of 0.5 M and thermostatted at 70 ° C. 189.4 milliliters (171.85 grams, 1.65 moles) of styrene were premixed with 810.6 milliliters of cyclohexane. The mixture was dosed through 60 minutes by means of an injection pump reducing the rate of addition in the form of a gradient as described in Example 3. After a 10 minute post-reaction time, 442.2 were dosed. grams of styrene and 400 milliliters of cyclohexane through 15 minutes. After an additional 15 minutes, 546 milligrams of ethyl formate in 2 milliliters of cyclohexane were added per drop to the point of complete decolorization. The polymer was treated as described in Example 1. Yield: 884 grams (99.9 percent); Volatile: 0.05 percent; Styrene content (FTIR): 69.4 percent (theoretical 69.4 percent); DPE content (FTIR): 30.5 percent (30.6 percent theoretical); DPE monomer (component B): 381 parts per million; styrene monomer (component C): 5 parts per million; Tg (DSC, two stages of vitreous state transition equally high): 169 ° C; vitreous state transition stage width: 17 ° C, 106 ° C; vitreous state transition stage width: 18 ° C. Molar masses (GPC, polystyrene calibration, gram / mol): maximum principal M (maximum) 121,000, 72 percent area; secondary maximum M (maximum) 60,000, area at 28 percent.

Example 6 Preparation of random S / DPE copolymer with a molar ratio of S-DPE of 1.1: 1; initial charge of DPE and addition of S and tetrahydrofuran (THF). The reactor prepared as in Example 1, was charged at 25 ° C with 264.24 milliliters (270.38 grams, 1.5 moles) of DPE and 7.37 milliliters of a secondary butyl lithium solution of 0.5 M was thermostated at 70 ° C. 189.4 milliliters (171.85 grams, 1.65 moles) of styrene were premixed with 810.6 milliliters of THF. The mixture was dosed through 180 minutes by means of an injection pump reducing the rate of addition in the form of a gradient as described in Example 3. After a 15 minute post-reaction time, the batch was treated as described in Example 1. Yield: 403 grams (91.2 percent); Volatile: 3.7 percent; Styrene content (FTIR): 42.6 percent (theoretical 38.9 percent); DPE content (FTIR): 57.3 percent (61.1 percent theoretical); Tg (DSC): 159 ° C; vitreous state transition stage scale: 17 ° C; molar masses (GPC, polystyrene calibration, gram / mol): Mn 87,000, Mw 111,000, M (maximum) 108,000.

Example 7 Preparation of random S / l, 1-di (3,4-dimethylphenyl) ethylene copolymer having a molar ratio of S-di (3,4-dimethylphenyl) ethylene of 1.1: 1; initial charge of di (3,4-dimethylphenyl) ethylene and addition of S and cyclohexane. The reactor prepared as in Example 1 was charged at 25 ° C with 355.5 grams (1.5 moles) of freshly molten l, l-di (3,4-dimethylphenyl) ethylene and 8.79 milliliters of a secondary butyl-lithium solution of 0.5. M and thermostatted at 70 ° C. 189.4 milliliters were premixed (171.85 grams, 1.65 moles) of styrene with 810.6 milliliters of cyclohexane. The mixture was dosed through 180 minutes by means of an injection pump reducing the rate of addition in the form of an ingredient as described in Example 3. After a 15 minute post-reaction time the batch was treated as described in Example 1. Yield: 525 grams (99.5 percent); Volatile: 0.2 percent; Styrene content (FTIR): 32. 7 percent (32.6 percent theoretical); monomer DPE (component B): 65 parts per million; styrene monomer (component C): 9 parts per million; Tg (DSC): 175 ° C; Stage width of vitreous state traverse: 14 ° C; molar masses (GPC, polystyrene calibration, gram / mol): Mn 36,000, Mw 90,000 M (maximum) 89,000.

Claims (10)

R E I V I N D I C A C I O N S

1. Thermoplastic molding compounds comprising as essential components: A) from 10 percent to 100 percent copolymers of the monomers of the general formulas I and II wherein R 1 is H or alkyl of 1 to 22 carbon atoms; R2 is H or alkyl of 1 to 22 carbon atoms, R3 is H or alkyl of 1 to 4 carbon atoms, a is 0, 1, 2, 3, 4 or 5, and b is 0, 1, 2, 3, 4 or 5, B) from 0 to 3,000 parts per million based on the weight of component A, of compounds of general formula I, C) from 0 to 500 parts per million, based on the weight of component A, of compounds of general formula II, D) from 0 percent to 90 percent by weight based on the total weight of the molding compound, of polymers other than A), and E) from 0 percent to 50 percent by weight, based on in the total weight of the molding compound, of additives and of processing aids. The thermoplastic molding compounds according to claim 1, comprising from 0 to 1,000 parts per million of component B), based on the total weight of component A). The thermoplastic molding compounds according to any of claims 1 and 2, comprising from 0 to 100 parts per million of component B), based on the total weight of component A). The thermoplastic molding compounds according to any of claims 1 to 3, comprising a polymer of 1,1-diphenylethylene and styrene as the component A. 5. A process for producing thermoplastic molding compounds in accordance with any of claims 1 to 4, by anionic polymerization, comprising providing the monomers of the formula I as the initial charge and dosing the monomers of the formula II during the reaction according to a gradient method, such that, as the reaction proceeds, the amount of monomer II that is added per unit time is essentially reduced according to the amount of monomer I still present. 6. A process according to claim 5, wherein the refractive index of the reaction mixture is continuously determined during the reaction and the monomer II is added according to a gradient method with a function of the change in the rate of refraction. 7. The block copolymers with blocks A and B of the following general structure: (A - B) n A - B - AB - A - BX [(A - B) n] m, X [(B - A) n] m, X [(A-B-A) n] m, or X [(B-A-B) n] m wherein A is a block of monomer copolymers of the general formulas I and II, B is a block of monomers of the general formula II, X is the radial of a m-functional coupling agent, n is an integer from 1 to 5, and m is an integer from 2 to 20. 8. The use of block copolymers of according to claim 7, for producing polymer blends with styrene polymers. 9. The thermoplastic molding compounds comprising as essential components a block copolymer according to claim 7, from 0 to 3,000 parts per million of monomers of the general formula I and from 0 to 500 parts per million of monomers of the formula General II. The use of thermoplastic molding compounds according to any of claims 1 to 4 or 9, to produce fibers, films and shaped articles. SUMMARY OF THE INVENTION Thermoplastic molding compound comprising as essential components A) from 10 to 100% by weight of copolymers of the monomers of the general formulas I and II wherein R 1 is H or alkyl of 1 to 22 carbon atoms, R 2 is H or alkyl of 1 to 22 carbon atoms, R 3 is H or alkyl of 1 to 4 carbon atoms, a is 0, 1, 2, 3, 4 or 5, and b is 0, 1, 2, 3, 4 or 5, B) from 0 to 300 ppm, based on the weight of component A), of the compounds of general formula I, C) from 0 up to 500 ppm, based on the weight of component A), of the compounds of general formula II, D) from 0 to 90% by weight, based on the total weight of the molding compound, of polymers other than A), and E) from 0 to 50% by weight, based on the total weight of the molding compound, of additives and processing aids. "WSL