DE4223983A1 - Co:polycarbonate blend for (optical) moulding, coating, etc. - Google Patents

Abstract

Compatible, transparent, thermoplastic polymer blend (I) consists of a copolycarbonate (II) and a methacrylate copolymer (III). (II) comprises 95-5% bisphenol A units (IIA) and 5-95% bisphenol units of formula (IIB). In the formula, R1 is H or 1-6C alkyl; R2 is 1-6C alkyl, (substd.) 5-16C cycloalkyl, phenyl, benzyl and/or 2-phenylethyl; or R1+R2 is (substd.) 4-16C cycloalkylidene; and either: (a) (III) has mol. wt. of at least 3 x 10 power(4) and consists of 99-1% methyl methacrylate (MMA) units, 1-9% (meth)acrylate ester units with carbocyclic gps. of formula CH2=C(R3)-CO-O-X (IVA) and 0-40% other alpha,beta-unsatd. monomer units (IVB); R3 is H or Me; X is Y or Q-Y; Y is opt. substd. 5-12C cycloalkyl or opt. (hydroxy)alkyl-substd. 6-12C aryl; Q is 1-6C alkylene or 2-6C oxaalkylene; or (b) (III) is replaced by an at least 2-phase impact modifying agent (V), consisting of 20-90 pts. opt. crosslinked through phase with Tg less than 10 deg.C, 80-10 pts. (III), at least partly covalently combined with this, and opt. another 0-50 pts. (III), in which case (I) contains 5-95% (II) and 95-5% (V).

Description

Field of the Invention

The invention relates to compatible polymer mixtures which are characterized by high transparency, from Co- Polycarbonates A) and methacrylate copolymers B) and their applications.

State of the art

Polymer blends that are an aromatic polycarbonate included are known.

According to DE-OS 23 29 585 are by mixing the thermoplastic polystyrene and aromatic Polycarbonate containing 2,2-bis- (3,5-dimethyl-4- hydroxyphenyl) propane units, compatible and Obtain transparent molding compounds. In contrast to that Mixtures of 2,2-bis (4-hydroxyphenyl) propane Polycarbonate (bisphenol-A polycarbonate) and polystyrene incompatible.

JP 72 16 063 describes mixtures of Polymethyl methacrylate, a crystal clear, transparent Plastic and bisphenol-A polycarbonate, one too transparent plastic, as mixtures with pearl-like Shine, a clear indication that none here homogeneous, transparent polymer mixtures are present.  

An improved polycarbonate molding composition is according to DE-A 22 64 268 (= FR-A 2 167 650) received if the Polycarbonate is a methacrylate copolymer consisting of 90 to 75% by weight methyl methacrylate and 10 to 25% by weight an alkyl (meth) acrylate of the formula

wherein
X represents hydrogen or methyl and R represents an organic radical having 4 to 12 carbon atoms, is added. The addition of 0.01 to about 50% by weight of copolymer continuously reduces the melt viscosity of the polycarbonate without impairing the transparency with increasing addition of the copolymer. These copolymers are therefore polymeric plasticizers whose average molecular weights M _w , as can be determined, for example, with the aid of gel permeation chromatography or the scattered light method (see, for example, HF Mark et al. Encyclopedia of Polymer Science and Technology, Vol. 10, Pages 1 to 19, J. Wiley, 1987), in order to achieve the compatibility described, based on our own experiments with corresponding copolymers, must be M _w 15,000 Daltons. For the production of polymer alloys, which also have technically interesting properties in the area of high polymethacrylate fractions, the above-mentioned copolymers are, however, because of the known decrease in mechanical properties in the molecular weight range M _w <5 × 10 ⁴ daltons, in particular M _w <3 × 10 ⁴ daltons completely unsuitable (see, for example, Kunststoff-Handbuch, Vol. IX, pages 112 ff, Vieweg / Esser). Thermoplastic molding compositions as polymer mixtures consisting of polycarbonate, a copolymer of methyl methacrylate, styrene and N-phenylmaleimide and a rubber grafted with methyl methacrylate are not compatible according to EP-A 1 73 146.

Likewise, those known from EP-A 1 44 231 are known Polymer blends consisting of a polycarbonate and a copolymer of methyl methacrylate and N- Phenylmaleimide and / or one with methyl methacrylate and N-phenyl maleimide grafted EPDM rubber, not full compatible and therefore not transparent.

EP 2 62 502 (= US 4,749,745) describes thermoplastic Processable methyl methacrylate copolymers with Methacrylamides as comonomers with amide nitrogen are substituted by a cyclic radical and none have pronounced UV absorption capacity. This Copolymers form with polycarbonates, especially with Bisphenol A polycarbonates, transparent, thermoplastic processable polymer blends.

In EP-A 2 83 975 (= US 4 950 716) transparent, thermoplastically processable polymer mixtures Bisphenol A polycarbonate and methacrylate copolymers, made up of methyl methacrylate and N- Cyclohexylmaleimide units described. To build the Methyl methacrylate copolymers can still optionally further monomers in amounts of 0 to 40 wt .-% based on the monomers are also used. The above can advantageously Polymer blends due to their low optical Birefringence and low water absorption for optical Components are used.

EP-A 2 97 285 (= US 4 906 696) relates to transparent, thermoplastically processable polymer mixtures Bisphenol A polycarbonates and methacrylate Copolymers consisting of 95 to 5 wt .-% methyl methacrylate  and 5 to 95% by weight of acrylic and / or Methacrylic acid esters with carbocyclic groups in the Ester residue are prepared and the other α, β- unsaturated monomers as polymer building blocks in amounts of 0 can contain up to 40 wt .-%.

EP-A 3 21 878 (= US 4 906 699) and EP-A 3 26 938 (= US 4,997,883) describe impact modifiers for Bisphenol A polycarbonate, which are copolymers, consisting of an elastomer component and a Methyl methacrylate copolymer portion that is covalent are interconnected, the methyl methacrylate Copolymer itself is one that is bisphenol- A polycarbonate is compatible.

Task and solution

Mixtures of polymers are usually incompatible. Despite a growing number of Counterexamples found in recent years the experiences of the expert are still today determined by the following sentence: "Miscibility is the exception, immiscibility is the rule "(see: Kirk- Othmer, Encyclopedia of Chemical Technology, 3rd. Ed., Vol. 18, page 460, J. Wiley, 1982).

Lately there has been interest in tolerable Polymer blends reinforced, which usually have the advantage the thermoplastic processability with that of Combine recyclability and transparency. Connected to the above Benefits are usually reproducibly adjustable, generally quite satisfactory mechanical properties.  

Bisphenol A polycarbonate are replaced by partial ones the bisphenol A group, for example by Cyclohexylidene or cyclododecylidene bisphenol, so-called co-polycarbonates A) derivable, which clearly higher heat resistance than bisphenol-A- Have polycarbonate. Contradicting this, however a relatively high inconsistency to Weather influences (as with bisphenol A Polycarbonate), a bisphenol A polycarbonate significant drop in toughness and a high Melt viscosity, the high processing temperatures and thus a thermo-oxidative load on component A) conditionally.

When looking for compatible polymer alloys PM consisting of copolycarbonates A) and methacrylate Copolymers B) [and this does not only apply to mixtures from A) and B)], the person skilled in the art generally cannot Analogies to bisphenol A polycarbonate (or general: other mixture components). For example, the slightest changes in the Copolymer compositions with compatible Mixtures of two copolymers for intolerance lead [cf. see for example J. Pfennig, H. Keskkula, J. Barlow and D. Paul, Makromolecules 18, pages 1937 ff (1985); H.W. Kammer et al. Acta Polymerica 40 (2), Pages 75 ff (1989)].

It has now been found that, surprisingly, certain mixtures of copolycarbonates A) and methacrylate copolymers B) form compatible transparent polymer alloys PM. These polymer alloys are made up of copolycarbonate A) containing:
a1) 95 to 5 wt .-% bisphenol A units and
a2) 5 to 95% by weight of bisphenol units of the formula I:

wherein R ₁ for hydrogen or an optionally branched alkyl radical with 1 to 6 carbon atoms and R ₂ for an optionally branched alkyl radical with 1 to 6 carbon atoms, for an optionally substituted cycloalkyl radical with 5 to 16 carbon atoms, for phenyl, benzyl and / or 2-phenylethyl , and R ₁ and R ₂ together can represent an optionally substituted cycloalkylidene radical having 4 to 16 carbon atoms
and the methacrylate copolymer B) consisting of:
b1) 99 to 1% by weight of methyl methacrylate units and optionally further α, β-unsaturated monomer units different from b2) in amounts of 0 to 40% by weight and
b2) 1 to 99% by weight of acrylic and / or methacrylic ester units of the formula II with carbocyclic groups in the ester radical:

in which R _{3 is} hydrogen or methyl and X is Y or QY, Y being an optionally substituted cycloalkyl radical having 5 to 12 carbon atoms or an optionally alkyl- or oxyalkyl-substituted aryl radical having 6 to 12 carbon atoms, and Q being an alkylene group having 1 up to 6 carbon atoms, which can also be branched, or can represent an oxyalkylene group with 2 to 6 carbon atoms,
and that the methacrylate copolymer B) has a molecular weight M _w of at least 3 × 10 ⁴ daltons.

The proportions of the monomer groups a1) and a2) on the one hand and b1) and b2) on the other hand complement each other 100% by weight.

Another advantageous embodiment of the invention Mixtures PL of the copolycarbonate A) and one two-phase impact modifier C), consisting from an elastomer phase with a glass transition temperature Tg <10 degrees C and one with this at least partially linked hard phase from copolymer B), the one have surprisingly high toughness.

The co-polycarbonates A)

The copolycarbonates A) consist of bisphenol A units and bisphenol units according to claim 1, such as for example 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1- Bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-  hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis- (4- hydroxyphenyl) cyclooctane, 1,1-bis (4-hydroxyphenyl) cyclo dodecane, 2,2-bis (4-hydroxyphenyl-1-phenylethane, 1,1-bis (4-hydroxyphenyl) -1-phenylmethane, 3,3-bis (4-hydroxy phenyl) -2,4-dimethylpentane or 4,4-bis- (4-hydroxyphenyl) heptane, 1,1-bis (4-hydroxyphenyl) cyclododecane and 1,1- Bis (3,5-dimethyl-4-hydroxyphenyl) cyclododecane (cf. also Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd. Ed. Vol. 18, pages 479 to 494, Vol. 6, pages 106 to 116, J. Wiley, 1982). O.g. Bisphenols possess as Homo-polycarbonates, i.e. H. after reaction with phosgene, in some cases significantly higher glass transition temperatures than Tg Bisphenol-A polycarbonate and therefore also higher Heat resistance. Accordingly, the Glass transition temperatures Tg of copolycarbonates A) containing bisphenol A units and the above Bisphenols, with increasing share of the above Bisphenols. For example the homopolycarbonate with 1,1-bis- (4- hydroxyphenyl), 3,3,5-trimethylcyclohexane units Tg = 239 degrees C on, compared to bisphenol A polycarbonate with a Tg = 148 degrees C. Commercially available copolycarbonates (e.g. APEC-HT®- Types, Bayer), consisting of the aforementioned units, have glass transition temperatures of up to about 190 Grade C.

The average molecular weights M _{w of} the copolycarbonates (for determining M _w so) are in the range from 2 × 10 ⁴ to 6 × 10 ⁴ daltons and the Vicat softening temperatures, measured in accordance with DIN 53 460, correspond approximately to the glass transition temperatures.

The polymethacrylate copolymers B)

The preparation of the copolymers B) is known Process for the polymerization of α, β-unsaturated Compounds, especially through radical ones Polymerization, for example in bulk, in solution or carried out as suspension polymerization: As For this purpose, polymerization initiators can contain azo compounds, such as azodiisobutyronitrile, peroxides, such as dibenzoyl peroxide or dilauroyl peroxide, or redox systems, or the Starting radicals can be generated by chemical radiation (cf. see for example H. Rauch-Puntigam, Th. Völker "Acrylic and methacrylic compounds", Springer-Verlag, Heidelberg, 1967; Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 1, pages 386 ff, J. Wiley & Sons, 1978).

The copolymers B) according to the invention preferably contain 5 to 95% by weight of methyl methacrylate units, particularly preferably 20 to 90% by weight, very particularly preferably 50 to 80% by weight, and correspondingly very particularly preferably 20 to 50% by weight. % of the acrylate and / or methacrylate units of the above formula I copolymerized with the methyl methacrylate. The copolymer B) can contain further α, β- in quantities of 0 to 40% by weight, in particular in quantities of 1 to 25% by weight. contain unsaturated monomer units, such as styrene, α-methylstyrene, acrylic acid, methacrylic acid and / or C2- to C10-alkyl esters of acrylic or methacrylic acid, where the alkyl groups can optionally be branched. The compatibility of polymers depends on their molecular weight, and the tolerance of polymers generally decreases with increasing molecular weight. The copolymers B) according to the invention have average molecular weights M _w , as can be determined, for example, with the aid of light scattering or gel permeation chromatography (see above), from more than 3 × 10 ⁴ to about 3 × 10 ⁵ daltons, preferably 5 × 10 ⁴ to 1.5 × 10 ⁵ Dalton on. This corresponds to reduced viscosities η _spec / C, measured in accordance with DIN 51 562 in chloroform as solvent, from about 18 to 110 cm ³ g ^-1 , preferably 30 to 75 cm ³ g ^-1 . The molecular weights are adjusted by polymerization in the presence of molecular weight regulators, such as, in particular, the mercaptans known for this purpose (see, for example, Houben-Weyl, Methods of Organic Chemistry, Volume XIV / 1, page 66, 1961; Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 1, page 296, John Wiley & Sons, 1978).

Monomers of the formula I which can be used, for example are: cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, Cyclooctyl (meth) acrylate, 3,3,5-trimethylcyclohexyl (meth) acrylate, 2-cyclohexylethyl (meth) acrylate, 3- Cyclohexylpropyl (meth) acrylate, 4-t-butylcyclohexyl (meth) acrylate, phenyl (meth) acrylate and its alkyl, alkoxy and alkylamine-substituted derivatives with 1 to 6 Carbon atoms in the alkyl radical, such as in particular the p- Methoxyphenyl (meth) acrylate, the N, N-dialkylamino substituted phenyl (meth) acrylates or Alkyl (oxy) phenyl (meth) acrylates, such as 2-phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, 1-phenylethyl (meth) acrylate, 2-phenylethyl (meth) acrylate, 3-phenylpropyl (meth) acrylate, 2-naphthyl (meth) acrylate.

The copolymers B) according to the invention can be thermoplastic to crystal-clear, colorless moldings process, the Vicat softening temperatures according to DIN 53 460 from about 100 to 130 degrees C.  

The impact modifiers C)

The impact modifiers C) for the copolycarbonates A) are polymers consisting of at least two phases, a tough phase c1) and one at least partially covalently linked to c1) Hard phase c2).

By definition, the tough phase c1) is a polymer with a glass transition temperature Tg <10 degrees C, preferably <-10 degrees C (for the determination of Tg see, for example, A.Turi, "Thermal Characterization of Polymeric Materials", pages 169 ff. Academic Press, New York, 1981). The polymers c1) are preferably selected from the group consisting of polyolefins, polydienes, polysiloxanes and polyacrylates. The polyolefins are preferably homopolymers or copolymers of ethylene, propylene and isobutylene (cf. Ullmanns Encyklopadie der Technischen Chemie, 4th edition, vol. 19, pages 167 to 226, Verlag Chemie, 1980). In general, the average molecular weight M _{w of} the polyolefins is in the range between 10⁴ and 10⁶ daltons. Of particular interest are ethylene-propylene-diene polymers (EPDM: see Ullmann loc.cit., Vol. 12, pages 619 to 621; Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd. Ed., Vol. 8, pages 492-500, J. Wiley, 1979). Dicyclopentadiene, ethylidene norbornene or trans-hexadiene-1,4 is preferably used as the diene component. The molecular weights M _{w of} the large-scale EPDM polymers are generally in the range between 5 × 10 ⁴ and 5 × 10 ⁵ Daltons. The dynamic freezing temperatures are specified as -45 to -30 degrees C (sequence types), the terpolymers being completely amorphous for ethylene contents of up to 60% by weight. In addition to EPDM polymers, EPTM polymers (ethylene-propylene-triene) can also be used.

In particular, the rubber types known in the art, such as polybutadiene, poly-2-chlorobutadiene or polyisoprene, are used as polydienes (cf. Ullmann, loc.cit., 4th edition vol. 12, pages 595 to 635). The molecular weight M _w is usually between 10 ⁴ and 10 ⁶ daltons.

Polysiloxanes (MQ, MPQ, MPVQ according to ISO 1629, 1st edition 1976) may also be mentioned as tough phase c1). The customary silicone rubbers usually have a polydimethylsiloxane chain modified by special substituents (cf. Ullmann, loc.cit., Vol. 13, pages 628 to 663). The types that crosslink at room temperature are terminally functional-functional polysiloxanes with molecular weights M _w between 10 ⁴ and 10 ⁶ daltons. The hot-vulcanizing types, mostly based on polydimethylsiloxane (MQ), can be crosslinked with rapidly disintegrating diacyl peroxides at elevated temperatures, for example at 150 degrees Celsius. For c1), preference is given to using polyacrylates whose monomer units ensure a glass transition temperature Tg of the resulting homopolymer or copolymer of <10 degrees C, preferably <-10 degrees C. The glass transition temperature of the homopolymers or copolymers is known or can be predetermined in a known manner (see, for example, J. Brandrup, EH Immergut, Polymer Handbook, III, pages 144 to 148, J. Wiley, 1975). The polyacrylates are preferably prepared by polymerization in aqueous emulsion, in some cases also in suspension. In the case of polyacrylates as tough phase c1), production by emulsion polymerization is particularly preferred, since materials with a defined particle structure can be produced particularly easily in this way. Latex particles with an outer shell c2), consisting of the copolymer B) according to claim 1, which contain a rubber made of cross-linked polyacrylate c1) on the inside are particularly preferred. Latex particles with an at least three-stage structure are very particularly preferred, ie those particles which still have a hard polymer core in polyacrylate c1). Overall, these polyacrylate particles, which make up the impact modifier C), should have a diameter of 0.1 to 3 μm, preferably 0.15 to 1 μm (with embedded hard core). In principle, the structure of such latex particles and the isolation of the polymer solid is described in DE-A 33 00 256 (= US 4,513,118).

The emulsion polymerization is expediently carried out in the neutral or slightly acidic pH range, the use of long-chain alkyl sulfates or alkyl sulfonates being favorable. The known azo compounds and organic or inorganic peroxides such as persulfate / bisulfite are suitably used as initiators. The initiator content is generally in the range between 10 ^-3 and 1% by weight, based on the monomers. Acrylic monomers which may be mentioned are in particular ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and alkoxy acrylates (cf. US 3,488,321). As a rule, these acrylate elastomers c1) also contain crosslinking monomers, such as, for example, allyl methacrylate or ethylene glycol dimethacrylate, in proportions of 0.1 to 5% by weight. Ethyl acrylate and butyl acrylate are the main constituents.

The hard phase c2) according to copolymers B) Claim 1 is at least with the tough phase c1) partially covalent, d. H. to more than 5 wt .-% based on c2), linked. To make the link effective, are preferably known crosslinking in the tough phase c1) Monomers with at least two radically activatable C = C double bonds in the molecule, such as di- or tri (meth) acrylates. Particularly preferred are so-called graft crosslinkers, such as allyl (meth) acrylate or triallyl cyanurate. They come preferably in quantities from 0.1 to 5% by weight based on c1) for use. The production of the impact modifier C) can based on known methods as follows become. In general, polymer c1) is added, for example selected from the group polyolefins, Polydienes or polysiloxanes, before, preferably in the form a solution in a suitable for further processing Solvents, for example in one for the radical polymerization of the monomers c2) or B) suitable solvents (see H. Rauch-Puntigam, Th. Völker, Acryl- und Methacrylverbindungen, Springer, 1967; J. Brandrup, E.H. Immergut, Polymer Handbook, loc.cit.). Here u. a. the tendency of the solvent to Consider transmission reactions. Be mentioned for example esters such as butyl acetate or ethyl acetate, Hydrocarbons such as toluene or ketones such as acetone. Man generally uses solutions with a content of 10 up to 60 wt .-% of the polymer c1) from which the  Monomers according to c2) and polymerization aids for example, can be added by dropping. The Polymerization is usually carried out at elevated temperature for example in the range between 80 to 140 degrees C. carried out. The usual initiators can be used as initiators how peroxides or azo compounds are used (cf. see H. Rauch-Puntigam, Th. Völker, Acryl- and Methacrylic compounds, loc.cit.). With lower boiling Solvents are e.g. B. dibenzoyl peroxide applicable, while with higher boiling solvents z. B. tert. Butyl compounds such as tert-butyl peroctoate are useful Can find application. But as a solvent also the monomers themselves building up the polymer c2) to serve.

Advantageously, you win that Impact modifier C) by precipitation from the Solution, for example with methanol as a precipitant, or by degassing on the extruder. Especially in the case of Latex dispersions can be obtained by C) Precipitation, spray drying, freeze coagulation or through Squeezing can be obtained on the extruder.

Characterization and preparation of the invention Polymer blends PM and PL

The characterization of the invention Polymer mixtures PM are made as compatible mixtures according to the recognized criteria (see Kirk-Othmer, loc.cit., vol. 18, pages 457 to 460; Brandrup, Immergut, Polymer Handbook, 2nd. Ed., III page 211, Wiley Interscience, 1975).  

With the compatible polymer mixtures (= polymer alloys) PM, a refractive index and a single glass transition temperature are observed, which is between those of the two polymer components A) and B). As a further indication of the compatibility of polymer mixtures, the occurrence of the LCST (Lower Critical Solution Temperature) is used, the existence of which is based on the process that when the transparent mixture, which had been clear until then, separates into different phases and becomes optically cloudy. This method provides clear evidence that the original polymer mixture consisted of a single homogeneous phase in thermodynamic equilibrium (see, e.g., BDR Paul, Polymer Blend & Mixtures, pages 1 to 3, Martinus Nÿhoff Publishers, Dosdrecht, Boston 1985). To this end, the cloud point T _Tr (cloud temperature) is determined experimentally, for example on a Kofler heating bench (cf. Chem. Ing.-Technik, pages 289, 1950).

The mixtures PM and PL can be different Mixing processes can be produced, such as through intensive mechanical mixing of the components in the melt or in the extruder. The polymer blends PM can also be made from a common solvent so-called "solution cast polyblends" can be produced (see Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd. Ed., Vol. 18, pages 443 to 478, J. Wiley, 1982): In another procedure, the Production of the polymer mixtures PM co-polycarbonate A) in the monomer mixture of the other copolymer B) are resolved, with B) in the presence of A) Polymerization is made. The mix type are no limits.  

First you create mechanical mixtures of the Mixture components, advantageously of solids such as granules or bead polymers is assumed using slow running Aggregates such as B. drum, wheel, double chamber or Ploughshare mixers. The slow-running mixing units cause mechanical mixing without the Phase boundaries are removed (see Ullmanns Encyclopedia of Technical Chemistry, 4th ed., Vol. 2, Pages 282 to 311, Verlag Chemie). The thermoplastic Preparation is then carried out by homogeneous mixing in the melt using heatable Mixing units at the appropriate temperatures, such as B. in kneaders at 150 to 300 degrees C or preferably in extruders, such as single or Multi-screw extruders or, if necessary, in extruders with oscillating screw and shear pins (e.g. in the Bussco Kneader).

Advantageous effects of the invention

The polymer alloys PM according to the invention 1 can already because of their tolerance Claim interest in technology. The polymer blends PM are usually crystal clear and transparent. The minor Flowability of the copolycarbonates A) is achieved by Alloy even small amounts of copolymer B) significantly increased while the low Heat resistance of the copolymers B) by Alloying of A) is increased.

Another interesting application is through the increase in the notched impact strength of the copolycarbonate

• A) by admixing the impact modifier C), that preferably consists of an elastomer phase c1) and one hard phase c2) compatible with A), opened [c2) corresponds in composition to copolymer B)].

The following examples serve to explain the Invention.

The following properties were determined:

• 1. LCST by measuring the cloud point T _Tr on the Kofler heating bench (see above)
• 2. VICAT softening temperature VET in degree C according to DIN 53 460
• 3. Reduced viscosity η _spec / C in chloroform according to DIN 51 562
• 4. Average molecular weight M _w by gel permeation chromatography (see above)
• 5. Glass transition temperature Tg by differential thermal analysis (DSC, see above)
• 6. Impact strength (SZ) and notched impact strength (KSZ) according to DIN 53 453 or ISO / R 179

EXAMPLES example 1 Exemplary preparation of the copolymers B

0.2 part by weight, based on the total of the monomers, of dilauroyl peroxide as the polymerization initiator and 0.55 part by weight of dodecyl mercaptan as the molecular weight regulator are added to the monomer mixture composed of methyl methacrylate, monomers of the formula I in claim 1 and possibly further monomers. This solution is polymerized in a film tube in a film tube for 18 hours at 50 degrees C and 22 hours at 60 degrees C and annealed in the drying cabinet for 3 hours at 110 degrees C. The average molecular weight M _{w of} the polymers thus prepared is between 6 × 10 ⁴ and 1.5 × 10 ⁵ daltons, the specific intrinsic viscosity η _spec / c in the range between 40 to 75 cm ³ g ^-1 .

Example 2 Production and characterization of the polymer mixtures PM from copolycarbonate A) and copolymer B)

The copolymers B) prepared according to Example 1 are coated with the copolycarbonate APEC® HT 9351 (Bayer), a copolycarbonate composed of 65 mol% bisphenol A and 35 mol% 3,3,5-trimethylcyclohexylidene -Bisphenol units, mixed in a drum mixer in the specified mixing ratios and extruded as a tape on a single-screw extruder. Visual tests, measurements of the glass transition temperature Tg, measurements of the VICAT softening temperature, and the turbidity temperature T _{Tr are} determined on strip samples:

Example 3 Production of the impact modifier C) for co- Polycarbonate A) with core-shell structure

In a Witt'schen pot with heater, stirrer and one Volume of 6 liters are 1170 g of water (dist.), 0.1 g Acetic acid (conc.), 0.005 g iron (II) sulfate and 25 g one Monomer emulsion ME1, consisting of 1775 g dist. Water, 4 g of C15 paraffin sulfonate, 1656 g of butyl acrylate and 33.8 g Allyl methacrylate, submitted and at 50 degrees C with 18 g tert-butyl hydroperoxide and 2.5 g sodium hydroxymethyl sulfinate started the polymerization. After reaching the Temperature maxima are reached within 2.5 hours a further 3450 g of the monomer emulsion ME1 are added and polymerized (core polymer).

After the reaction has subsided, the one obtained Dispersion kept at 50 degrees C. At this temperature a monomer emulsion ME2 is formed for 2 hours from 960 g dist. Water, 2 g C15 paraffin sulfonate, 455 g Methyl methacrylate, 455 g phenyl methacrylate and 4.6 g Dodecyl mercaptan, metered in and in the presence of 0.9 g Polymerized tert-butyl peroxide. After the end of the inflow it turns 30 reheated at 50 degrees C.

The impact modifier C) is by Freeze coagulation of the resulting polymer dispersion isolated as a powdery material.  

Example 4 Production and characterization of the polymer mixture PL from copolycarbonate A) and impact modifier C)

20 wt .-% (corresponding to 13 wt .-% butyl acrylate content) of Modifier C) described in Example 3 with 80 wt .-% co-polycarbonate A) APEC® HT 9351 (Bayer) mixed according to Example 2 and then granulated and injection molded. The result is a shiny, opaque Polymer mixture with significantly improved Notched impact strength and very good heat resistance: Property profile of the mixture according to Example 4

Claims (4)

1. Compatible, transparent and thermoplastic polymer mixtures PM, consisting of a copolycarbonate A) and a methacrylate copolymer B),
characterized,
that the copolycarbonate A) is composed of:
a1) 95 to 5 wt .-% bisphenol A units and
a2) 5 to 95% by weight of bisphenol units of the formula I. wherein R ₁ for hydrogen or an optionally branched alkyl radical with 1 to 6 carbon atoms and R ₂ for an optionally branched alkyl radical with 1 to 6 carbon atoms, for an optionally substituted cycloalkyl radical with 5 to 16 carbon atoms, for phenyl, benzyl and / or 2-phenylethyl, and R ₁ and R ₂ together can represent an optionally substituted cycloalkylidene radical having 4 to 16 carbon atoms and
that the methacrylate copolymer B) is composed of:
b1) 99 to 1% by weight of methyl methacrylate units and, if appropriate, further, α, β-unsaturated monomer units different from b2) in amounts of 0 to 40% by weight and
b2) 1 to 99% by weight of acrylic and / or methacrylic ester units of the formula II with carbocyclic groups in the ester radical: wherein R _{3 is} hydrogen or methyl and X is Y or QY, where Y is an optionally substituted cycloalkyl radical having 5 to 12 carbon atoms or an optionally alkyl or oxyalkyl-substituted aryl radical having 6 to 12 carbon atoms, and Q is an alkylene group 1 to 6 carbon atoms, which can also be branched, or can represent an oxyalkylene group with 2 to 6 carbon atoms,
and that the copolymer 3) has a molecular weight M _w of at least 3 × 10 ⁴ daltons, and that the proportions of the monomer groups a1) and a2) on the one hand and b1) and b2) on the other hand each add up to 100% by weight. 2. PL polymer mixtures, characterized in that they are composed of:
5 to 95 wt .-% co-polycarbonate A) according to claim 1, 95 to 5 wt .-% of an at least two-phase impact modifier C), consisting of:
c1) 20 to 90 parts by weight of at least one possibly crosslinked tough phase with a glass transition temperature Tg <10 degrees C and
c2) 80 to 10 parts by weight of at least one copolymer which is at least partially covalently linked to c1) and is compatible with the copolycarbonate A), the composition of which corresponds to the methacrylate copolymer B) according to claim 1 and
c3) optionally a further 0 to 50 parts by weight of methacrylate copolymer B) according to claim 1. 3. Use of the polymer mixtures PM and PL according to the Claims 1 and 2 for the production of moldings, Coatings and fiber reinforced laminates. 4. Use of polymer mixtures according to claim 1, for the production of for optical purposes usable moldings.