WO2000073377A1

WO2000073377A1 - Polycarbonate moulding materials with good demoulding properties and moulded bodies and semi-finished products produced with said materials, with good sliding properties

Info

Publication number: WO2000073377A1
Application number: PCT/EP2000/004677
Authority: WO
Inventors: Klaus Horn; Ralf Hufen; Wolfgang Ebert; Klaus Berg
Original assignee: Bayer Aktiengesellschaft
Priority date: 1999-06-01
Filing date: 2000-05-23
Publication date: 2000-12-07
Also published as: AU5215600A; JP2003501506A; EP1189982A1; AR024160A1; IL146256A0; CA2374445A1; CN1353737A; BR0011096A; MXPA01012389A; KR20020005766A

Abstract

The invention relates to polycarbonate moulding materials with good demoulding properties and to moulded bodies and semi-finished products produced with said polycarbonate moulding materials, with good sliding properties.

Description

Polycarbonate molding compounds with good demolding and molded articles and semi-finished products made from them with good sliding properties.

The present invention relates to readily demoldable polycarbonate molding compositions with fatty acid esters based on 1,2-dihydroxypropane and C 1 to C ₄ o-carboxylic acids as mold release agents, optionally in addition to other additives customary in polycarbonate.

Patents and publications on the release properties of additives in

Thermoplastics in general and in particular describing polycarbonate are known. The most common substances used as mold release agents are the esters from long-chain aliphatic acids and alcohols. Examples include the use of esters from fatty acid alcohols or polyols such as e.g. Pentaerythritol with fatty acids, as described in DE 33 12 158, EP 100 918, EP 103 107, EP 561 629,

EP 352 458, EP 436 117 or if Guerbet alcohols were used US 5 001 180, DE 33 12 157, US 5 744 626 and when using montanic acids as acid component US 4 097 435.

It is disadvantageous that the fatty acid esters only show a significant release effect from amounts of more than 0.5% by weight. However, these concentrations often lead to turbidity and or to the formation of mold deposits.

Other mold release agents such as long-chain ketones tend to form chromophores due to self-condensation and are difficult to access (EP

100 918).

Siloxanes which are also used (US Pat. No. 4,536,590, US Pat. No. 4,390,651, US Pat. No. 3,751,519) have sufficient temperature resistance, but are very poorly compatible with polycarbonate and, in the concentrations required for effectiveness, lead to undesirable cloudiness which compromises the applicability of severely restrict mainly in transparent settings of common material such as polycarbonate.

The e.g. α-olefin polymers described in EP-A-561 630 and EP-A-230 015, optionally with remaining double bonds (DE-A-32 44 499), are not color-stable. In the case of hydrogenated systems, as with the long-chain alkanes (US 4,415,696), there is a compatibility problem with polycarbonate that leads to cloudy and thus non-transparent molded parts. In addition, the waxy or liquid-waxy consistency of these products is a hindrance.

The distortion-free demoulding of polycarbonate molded parts, while maintaining the very high-quality surface, depending on the often very different molded part design, poses an everlasting challenge due to the demands for shorter cycle times and higher processing temperatures. Many problems can often only be overcome with a customized demolding formulation. There is therefore a constant need for new potential mold release agents.

Two forces act during the demolding process, static friction and sliding friction. The mold release must be designed in such a way that both forces are minimized without the formation of disruptive mold deposits.

The task was therefore to find mold release agents that equally minimize both mold release forces in order to enable all mold geometries to be removed from the mold without the formation of mold deposits.

Furthermore, the task was to find mold release agents which do not tend to transesterification with the polycarbonate and which do not lead to clouding or discoloration in the effective concentrations. Another object is to reduce problems caused by the adhesion of molded polycarbonate moldings, as occurs, for example, when cups are pulled apart after storage.

Another object is to reduce problems caused by the adhesion of molded polycarbonate moldings to metals, such as occurs when sliding on inclined metallic planes.

Another task is to control the tying force, which e.g. is important for toys. However, care must be taken to ensure that the components are precisely matched, since insufficient tying force is also undesirable in some applications.

The objects were achieved by using fatty acid esters based on 1, 2-dihydroxypropane and C] to C ₄ o-carboxylic acids as mold release agents, which have sufficient solubility and stability in polycarbonate.

The present invention relates to polycarbonate molding compositions with a content of 0.005 to 5.0% by weight, preferably 0.05 to 3.0% by weight, very particularly preferably 0.15 to 2.0% by weight, of fatty acid esters Basis of 1, 2-dihydroxy propane and C _\ to C ₄₀ acids and esters of 1,2-dihydroxypropane with mixtures of different Ci to C ₄ o-carboxylic acids where the alcohol can also be partially esterified and mixtures of partially esterified and fully esterified products and optionally using other additives customary in polycarbonate, such as, for example, thermal stabilizers, UV stabilizers, other mold release agents,

Flame retardants, anti-dripping agents, fillers, glass fibers and blend partners such as ABS, ASA, SAN, EPDM or polyesters based on terephthalic acid and diols, which are characterized in that the molding compositions on a demoulding force measuring tool (friction coefficient measuring tool) for the static and sliding friction coefficients of friction preferably <0.80, particularly preferably <0.60 and very particularly preferably <0.40, the Reference value of a mold release agent-free polycarbonate of the same viscosity measured on the friction coefficient tool has a value between 0.85 and 1.50.

The molding compositions according to the invention can be contaminated with impurities which contain the individual constituents of the molding composition from their synthesis, processing, processing and storage, as well as contaminations which originate during the production or processing of the molding compositions according to the invention. However, the goal is to work with as clean products as possible.

It is preferred if the molding compositions, if they contain free OH groups, contain less than 10 ppm ions, particularly preferably less than 5 ppm. This is especially true for ions of the elements Na, K, Mg, Ca, Sn, Ti, Fe, Ni, Cr.

It is preferred if the fatty acid esters to be used according to the invention, if they are partially esterified and contain free OH groups, contain less than 10 ppm ions, particularly preferably less than 5 ppm. This is especially true for ions of the elements Na, K, Mg, Ca, Sn, Ti, Fe, Ni, Cr.

The adhesion of molded parts made of polycarbonate is preferably reduced by the content of 1.5% by weight to 2.5% by weight of mold release agent.

The fatty acid esters according to the invention are commercially available.

Thermoplastic, aromatic polycarbonates in the sense of the present invention are both homopolycarbonates and copolycarbonates; the polycarbonates can be linear or branched in a known manner.

Some, up to 80 mol%, preferably from 20 mol% to 50 mol%, of the carbonate groups in the polycarbonates suitable according to the invention can be replaced by aromatic dicarboxylic acid ester groups. Such polycarbonates, the Both acidic residues of carbonic acid and acidic residues of aromatic dicarboxylic acids, incorporated into the molecular chain, are, to be precise, aromatic polyester carbonates. For the sake of simplicity, they should be summed up in the present application under the generic term of thermoplastic, aromatic polycarbonates.

The polycarbonates to be used according to the invention are produced in a known manner from diphenols, carbonic acid derivatives, optionally chain terminators and optionally branching agents, with some of the carbonic acid derivatives being produced by aromatic dicarboxylic acids or to produce the polyester carbonates

Derivatives of dicarboxylic acids are replaced, depending on the stipulations of the carbonate structural units to be replaced in the aromatic polycarbonates, by aromatic dicarboxylic acid ester structural units.

Details of the manufacture of polycarbonates have been recorded in hundreds of patents for approximately 40 years. As an example, just look at

Schnell, Chemistry and Physics of Polycarbonates, Polymer Reviews, Volume 9, Interscience Publishers, New York, London, Sydney 1964;

• D.C. Prevorsek, B.T. Debona and Y. Kesten, Corporate Research Center, Allied Chemical Corporation, Morristown, New Jersey 07960: "Synthesis of Poly (ester

Carbonate) copolymers "in Journal of Polymer Science, Polymer Chemistry Edition, Vol. 19, 75-90 (1980)";

• D. Freitag, U. Grigo, P.R. Müller, N. Nouvertne ', BAYER AG, "Polycarbonates" in Encyclopedia of Polymer Science and Engineering, Volume 11, Second Edition, 1988, pages 648-718 and finally

• Dres. U. Grigo, K. Kircher and P. R-Müller "Polycarbonate" in Becker / Braun, plastic manual, volume 3/1, polycarbonates, polyacetals, polyester, cellulose esters, Carl Hanser Verlag Munich, Vienna 1992, pages 117-299. The thermoplastic polycarbonates, including the thermoplastic, aromatic polyester carbonates, have average molecular weights M _w (determined by measuring the relative viscosity at 25 ° C. in CH ₂ C1 ₂ and a concentration of 0.5 g per 100 ml of CH ₂ C1 ₂ ) from 12,000 to 120,000, preferably from 15,000 to 80,000 and in particular from 22,000 to 60,000.

Diphenols suitable for the preparation of the polycarbonates to be used according to the invention are, for example, hydroquinone, resorcinol, dihydroxydiphenyl, bis (hydroxyphenyl) alkanes, bis (hydroxyphenyl) cycloalkanes, bis (hydroxyphenyl) sulfides, bis (hydroxyphenyl) ethers , Bis (hydroxyphenyl) ketones, bis (hydroxyphenyl) sulfones, bis (hydroxyphenyl) sulfoxides, (α, α'-bis (hydroxyphenyl) diisopropylbenzenes, and also their ring-alkylated and ring-halogenated compounds.

Preferred diphenols are 4,4'-dihydroxydiphenyl, 2,2-bis (4-hydroxyphenyl) -l-phenyl-propane, l, l-bis- (4-hydroxyphenyl) -phenyl-ethane, 2,2-bis- (4-hydroxyphenyl) propane, 2,4-bis (4-hydroxyphenyl) -2-methylbutane, 1,1-bis (4-hydroxyphenyl) -m / p diisopropylbenzene, 2,2-bis- (3-methyl-4-hydroxyphenyl) propane, bis (3,5-dimethyl-4-hydroxyphenyl) methane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, bis- (3,5-dimethyl-4-hydroxyphenyl) sulfone, 2,4-bis (3,5-dimethyl-4-hydroxyphenyl) -2-methylbutane, 1,1-bis- (3,5-dimethyl-4 -hydroxyphenyl) -m / p-diisopropyl-benzene, 2,2- and l, l-bis- (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane.

Particularly preferred diphenols are 4,4'-dihydroxydiphenyl, l, l-bis (4-hydroxyphenyl) phenylethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (3rd , 5-dimethyl-4-hydroxyphenyl) propane, l, l-bis (4-hydroxyphenyl) cyclohexane and l, l-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane.

These and other suitable diphenols are e.g. in U.S. Patent 3,028,635, U.S. Patent

2,999,835, US Pat. No. 3,148,172, US Pat. No. 2,991,273, US Pat. No. 3,271,367, US Pat. No. 4,982,014 and US Pat. No. 2,999,846, in the German patent applications DE- A-1 570 703,

DE-A-2 063 050, DE-A-2 036 052, DE-A-2 21 1 956 and DE-A-3 832 396, the - 1 -

French patent FR-A-1 561 518, described in the monograph "H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York 1964" and in Japanese Patent Publications 62039/1986, 62040/1986 and 105550/1986.

In the case of homopolycarbonates, only one diphenol is used, in the case of copolycarbonates, several diphenols are used, although the bisphenols used, like all the other chemicals and auxiliaries added to the synthesis, can of course be contaminated with the impurities from their own synthesis, although it is desirable to work with raw materials that are as clean as possible.

Suitable chain terminators are both monophenols and monocarboxylic acids. Suitable monophenols are phenol, alkylphenols such as cresols, p-tert-butylphenol, pn-octylphenol, p-iso-octylphenol, pn-nonylphenol and p-iso-nonylphenol, halophenols such as p-chlorophenol, 2,4-dichlorophenol, p-bromophenol and 2,4,6-tribromophenol, or mixtures thereof.

Suitable monocarboxylic acids are benzoic acid, alkylbenzoic acids and halogenated benzoic acids.

Preferred chain terminators are the phenols of the formula (I)

R ⁶ -Ph-OH (I)

wherein R ^{6 is} H or a branched or unbranched Ci -C ₈ alkyl radical.

The amount of chain terminator to be used is 0.5 mol% to 10 mol%, based on moles of diphenols used in each case. The chain terminators can be added before, during or after the phosgenation. Suitable branching agents are the trifunctional or trifunctional compounds known in polycarbonate chemistry, in particular those having three or more than three phenolic OH groups.

Suitable branching agents are, for example, phloroglucin, 4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptene 2,4,6-dimethyl-2,4,6-tri- (4-hydroxyphenyl) -heptane , 1, 3,5-tri- (4-hydroxyphenyl) -benzene, 1,1,1-tri- (4-hydroxyphenyl) -ethane, tri- (4-hydroxyphenyl) -phenylmethane, 2,2-bis - [4,4-bis (4-hydroxyphenyl) cyclohexyl] propane, 2,4-bis (4-hydroxyphenyl isopropyl) phenol, 2,6-bis (2-hydroxy-5'-methyl) -benzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane, hexa- (4- (4-hydroxyphenyl-isopropyl) phenyl) orthoterephthalic acid ester, tetra- (4- hydroxyphenyl) methane, tetra- (4- (4-hydroxyphenylisopropyl) phenoxy) methane and 1,4-bis (4 ', 4 "-dihydroxy-triphenyl) methyl) benzene and 2 , 4-dihydroxybenzoic acid, trimesic acid, cyanuric chloride and 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole.

The amount of branching agents which may be used is 0.05 mol% to 2.5 mol%, based in turn on moles of diphenols used in each case.

The branching agents can either be introduced with the diphenols and the chain terminators in the aqueous alkaline phase, or added dissolved in an organic solvent before the phosgenation.

The measures for producing the polycarbonates are familiar to the person skilled in the art.

Aromatic dicarboxylic acids suitable for the production of the polyester carbonates are, for example, phthalic acid, terephthalic acid, isophthalic acid, tert-butylisophthalic acid, 3,3'-diphenyldicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4-benzophenone dicarboxylic acid, 3,4'- Benzophenone dicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 4,4'-diphenyl sulfone dicarboxylic acid, 2,2-bis (4-carboxyphenyl) propane, trimethyl-3-phenyl indane-4,5'-dicarboxylic acid. Of the aromatic dicarboxylic acids, terephthalic acid and or isophthalic acid are particularly preferably used.

Derivatives of the dicarboxylic acids are the dicarboxylic acid dihalides and the dicarboxylic acid dialkyl esters, in particular the dicarboxylic acid dichlorides and the dicarboxylic acid dimethyl esters.

The carbonate groups are replaced by the aromatic dicarboxylic acid ester groups essentially stoichiometrically and also quantitatively, so that the molar

The ratio of the reactants is also found in the finished polyester carbonate. The aromatic dicarboxylic acid ester groups can be incorporated either statistically or in blocks.

Preferred methods of production of the polycarbonates to be used according to the invention, including the polyester carbonates, are the known interfacial process and the known melt transesterification process.

In the first case, phosgene is preferably used as the carbonic acid derivative, in the latter case preferably diphenyl carbonate. Catalysts, solvents, work-up, reaction conditions etc. for the production of polycarbonate are sufficiently described and known in both cases.

The molding compositions according to the invention are prepared by adding the alkanes according to the invention into the melt during synthesis or, in the case of the phase interface process, a work-up or concentration step, but also in solution, by simultaneously dissolving the polycarbonates in a polycarbonate solvent or successively mixed with the alkanes according to the invention and optionally further additives and the polycarbonate solvent is then evaporated. The present invention thus also relates to a process for the preparation of the polycarbonate molding compositions according to the invention, which is characterized in that polycarbonates are mixed with the esters according to the invention either simultaneously or successively, either in bulk or in solution, and then the mixtures either at temperatures between 260 ° C and 450 ° C ° C, preferably

260 ° C to 420 ° C and very particularly preferably 260 ° to 360 ° C melt-compounded or melt-extruded at temperatures between 250 ° C and 320 ° C, or the polycarbonate solutions are evaporated and the mixture obtained is granulated.

The polycarbonate molding compositions according to the invention can still be the usual

Additives, such as glass fibers, fillers, pigments, UV stabilizers, thermal stabilizers, antioxidants, flame retardants, impact modifiers and optionally other mold release agents, are present in the amounts customary for thermoplastic polycarbonates.

Suitable glass fibers are all commercially available glass fiber types and types, i.e. cut glass types long glass fibers (chopped strands) and short glass (milled fibers), provided that they are compatible with polycarbonate by suitable sizes.

The glass fibers used to manufacture the molding compounds are made from E-glass. According to DEN 1259, e-glass is an aluminum-boron-silicate glass with an alkali oxide content of less than 1% by weight. Glass fibers with a diameter of 8 to 20 μm and a length of 3 to 6 mm (chopped strands) are usually used. Short glass (milled fibers) can also be used, as can suitable glass balls.

Flame retardants such as find use in polycarbonate and can also be used in the molding compositions according to the invention are alkali metal salts of organic and inorganic acids, in particular sulfonic acids such as, for example

Sodium or potassium perfluorobutane sulfonate, potassium hexafluoroaluminate, sodium hexafluoroaluminate, potassium diphenylsulfone sulfonate, sodium 2-formylbenzenesulfonate, sodium (N-benzenesulfonyl) benzenesulfonamide, often in combination with other flame retardants, such as halogenated organic compounds such as, for example, tertrabromoligocarbonate, cryolite and teflon. Mixtures of the additives mentioned are also suitable.

These customary additives can be added in a known manner together with the components according to the invention or afterwards to the flame retardant polycarbonates.

The polycarbonate molding compositions according to the invention can be processed to moldings on the customary processing machines by known methods under the processing parameters customary for polycarbonate.

Injection molding is preferred.

The invention therefore also relates to parts made from the molding compositions according to the invention, such as molded parts and semi-finished products.

The molded parts are used, for example, in the electrical, electronics, lighting, computer, construction, vehicle and or aircraft sectors and in the packaging, food or toy industries

The molding compositions are suitable for injection molding and extrusion articles, such as, for example, films, cups, plates, twin-wall sheets, lights, housings for electrical appliances, computers or motor vehicle equipment such as panes, dashboard parts, lenses, coverings and the like or toy articles.

The demolding properties of the polycarbonate molding compositions according to the invention and the comparative examples of the prior art were measured on a demolding force measuring tool (friction coefficient measuring tool). The friction coefficients for static and sliding friction are determined, which represent a measure of the demolding forces for adhesion and sliding of the mold out of the injection molding tool.

A plate-shaped molded part with a melt temperature of 300 ° C and a mold temperature of 90 ° C is injected.

After cooling for 20 seconds, the molded part is rotated through an angle of 90 ° in the closed mold. A process data acquisition system measures the breakaway torque of the plate and the pressing force of the tool stamp on the plate. The coefficients are determined from the measurement parameters.

Examples

The amounts in the examples, expressed in% by weight, relate to the weight of the total mixture.

Examples 1 to 4 and Comparative Examples 1 to 4

An aromatic polycarbonate made from 2,2-bis (4-hydroxyphenyl) propane (melt index 10, measured according to DIN 53 735) with phenol as a chain terminator was melted at 300 ° C. in a twin-screw extruder (ZSK 32/2) with vacuum degassing . The amount of the ester according to the invention mentioned in the examples was then metered directly into the polycarbonate melt. The polymer strand was cooled in a water bath and then granulated. The granules were dried in a vacuum drying cabinet at 120 ° C. for 8 hours and sprayed on an injection molding machine with a melt temperature of 300 ° C. and a mold temperature of 90 ° C. to test specimens with the dimensions 60 mm × 40 mm × 4 mm thick .

Optical characteristics such as transmission and haze were measured on these sample plates.

The coefficients of friction were measured using a specially made measuring tool. In all tests in an Arburg Allrounder 320-210-850-D injection molding machine, the same plate-shaped molded part was always injected at a melt temperature of 300 ° C at a mold temperature of 90 ° C. After cooling for 20 seconds, the molded part is rotated through an angle of 90 ° in the closed mold. A process data acquisition system measures the breakaway torque of the plate and the pressing force of the tool stamp on the plate. The coefficients are determined from the measurement parameters.

The coefficient of static and sliding friction is used as a measure of the release effect. Smaller values are therefore advantageous compared to high values. Examples 1 and 2 and comparative examples 1 to 3 are listed in Table 1. A mold-free polycarbonate and a product containing PETS = pentaerythritol tetrastearate were given as a comparison.

The molding compositions according to the invention are distinguished by significantly smaller coefficients of friction and are already more effective in smaller quantities than the standard demoulder PETS used.

The molding compositions according to the invention were subjected to a sliding test molded part on molded part.

Beakers were injection molded for the test.

Two cups were put into each other without strength and pulled apart after an hour. The cups, produced from the molding compositions according to the invention (Examples 1 and 2), could be pulled apart without adhesion. Adhesive effects occurred in the cups from the molding compositions of Comparative Examples 1, 2 and 3.

Table 1

Comparison 1 Comparison 2 Comparison 3 Example Example 2

1

Polycarbonate 100.00 99.80 99.50 99.20 99.5

PETS 0 0.20 0.50

Grinsted PGMS SPV 0.20 0.50

Stiction coefficient. 1.06 0.52 0.34 0.29 0.27

Coefficient of sliding friction 0.85 0.59 0.38 0.38 0.32

Slide cup on _ _ + ++ +++

= great grip, poor gliding, + lower grip, moderate gliding, ++ = almost no grip, good gliding, +++ = no grip, very good gliding

The molding compositions according to the invention also show low haze and better transmission (examples 3 and 4) at higher mold release contents than comparative example 4 (see table 2).

Table 2

Comparison 3 Example 3 Example 4

Polycarbonate 99.00 99.00 98.00

PETS 1.00

Grinsted PGMS 1.00 2.00

SPV

Turbidity 1.8% 0.9% 1.0%

Transmission 84.3% 86.1% 86.2%

Claims

claims

1. polycarbonate molding compositions, characterized in that an ester of 1, 2-dihydroxypropane and C 1 to C ₄₀ carboxylic acids, preferably esters of 1, 2-dihydroxypropane with C ₁₀ to C ₄₀ carboxylic acids and very particularly preferably esters of 1, 2-dihydroxypropane with o to C ₂₅ -carboxylic acids and esters of 1,2-dihydroxypropane with mixtures of different carboxylic acids, the alcohol can also be partially esterified and mixtures of partially and fully esterified products in amounts of 0.005 to 5.0% by weight, preferably 0.01 to 3.0 wt .-%, very particularly preferably 0.02 to 2.0 wt .-% is contained.

2. Polycarbonate molding compositions according to claim 1, characterized in that the molding compositions on a demoulding force measuring tool (friction coefficient measuring tool) for the static and sliding friction coefficients of friction of preferably <0.80, particularly preferably <0.60 and very particularly preferably <0, 40, the reference value of a mold release agent-free polycarbonate of the same viscosity measured on the friction coefficient tool giving a value between 0.85 and 1.50.

3. Polycarbonate molding compositions according to claim 1, characterized in that the adhesion of molded parts from the molding compositions to metals is reduced, so that the sliding of the molded parts on inclined metallic levels is facilitated.

4. Polycarbonate molding compositions according to claim 1, characterized in that the adhesion and the sliding of manufactured molded parts on one another is reduced, so that, for example, intermeshed molded parts, such as cups, can be easily separated from one another.

5. Polycarbonate molding compositions according to claim 1, characterized in that the tying force of finished parts can be adjusted in a targeted manner so that the molded parts can be separated with defined forces.

6. Polycarbonate molding compositions according to at least one of the preceding claims, characterized in that other additives such as e.g. Thermal stabilizers, UV stabilizers, additional mold release agents, flame retardants, anti-dripping agents, fillers, pigments, glass fibers and blend partners such as ABS, ASA, SAN, EPDM or polyesters based on terephthalic acid and diols are included.

7. Polycarbonate molding compositions according to at least one of the preceding claims, characterized in that the mold release agent is present in amounts of 1.5% by weight to 2.5% by weight.

8. Polycarbonate molding compositions according to at least one of the preceding claims, characterized in that up to 80 mol%, preferably from 20 mol% to 50 mol% of the carbonate groups in the polycarbonates suitable according to the invention can be replaced by aromatic dicarboxylic acid ester groups .

9. A process for the preparation of polycarbonate molding compositions according to at least one of the preceding claims, characterized in that polycarbonates are mixed with esters either simultaneously or successively, either in bulk or in solution, and then the mixtures either

Temperatures between 260 ° C and 450 ° C, preferably 260 ° C and 420 ° C and very particularly preferably at 260 ° C to 360 ° C melt compounded or melt extruded at temperatures between 250 ° C and 320 ° C, or evaporating the polycarbonate solutions and that obtained mixture granulated.

10. The method according to claim 6, characterized in that further additives, such as glass fibers, fillers, pigments, UV, thermal stabilizers, antioxidants, flame retardants, impact modifiers and optionally other mold release agents together with the components according to the invention or thereafter the polycarbonate molding compositions be added.

11. Molded parts and semi-finished products containing one of the molding compositions of claims 1 to 8, preferably for applications in the electrical, electronics, lighting, computer, toy, packaging, construction, vehicle and / or aircraft sector.

12. Injection molding and extrusion articles containing one of the molding compositions of claims 1 to 8, preferably foils, plates, twin-wall sheets, lights, housings for electrical appliances, computers or motor vehicle equipment such as panes, dashboard parts, lenses, coverings and the like.