WO2009138388A1 - Use of organosilicon copolymers as impact-resistance modifiers - Google Patents

Abstract

The object of the invention is the use of organosilicon copolymers as impact-resistance modifiers, characterized in that the organosilicon copolymers comprise a) one or more polysiloxane units and b) one or more vinyl polymer units and that units a) and b) are linked together covalently such that they form a comb, block or ladder structure; and (meth) acrylic acid ester – silicon copolymers with comb, block or ladder structures obtained by way of radically initiated bulk or solution polymerization of a) one or more (meth) acrylic acid esters, b) one or more singly or multiply ethylenically unsaturated polyorganosiloxanes, and optionally c) one or more other ethylenically unsaturated monomers with the condition (proviso) that none of components a) through c) are selected from the group consisting of ethylenically unsaturated silanes substituted with alkoxy radicals, hydroxy-substituted (meth)acrylic acid esters, hydroxy-substituted (meth)acrylic acid amides, amino-substituted (meth)acrylic acid esters, unsaturated carboxylic acids, unsaturated carboxylic acid anhydrides and polyorganosiloxanes containing radicals with free hydroxy groups.

Description

 Use of organosilicone copolymers as impact modifiers

The invention relates to the use of organosilicone copolymers as toughening modifiers, to impact-modified polymer compositions and molding compositions obtainable as well as (meth) acrylic ester-silicone copolymers.

Molding compositions can be prepared from thermoplastic polymers by means of thermoplastic forming techniques such as injection molding, extrusion, compression or deep drawing. In order to improve the mechanical properties of molding compounds, such as their impact strength, impact modifiers are often used. Impact resistance is a measure of the resistance of a material to breakage when it is impacted, for example, by impact or impact. The impact resistance is measured as energy required to break per area and serves as a parameter for the strength of molding compounds. The impact strength of molding compounds is highly temperature-dependent. In particular, far below the glass transition temperature of their polymeric constituents molding compounds are brittle and break accordingly easy, which drastically limits their applications.

Examples of impact modifiers are rubbery additives such as graft copolymers having a core-shell structure containing an elastomeric siloxane or organopolymer core and a polymer shell grafted thereon. The cores are usually highly cross-linked and elastic and have particulate character. The elastomeric core is able to absorb and dissipate the energy introduced by impact stress. The grafted-on polymer shell ensures compatibilization and compatibility of the impact modifier with the individual constituents of the impact-modified polymer composition and thus counteracts phase separation.

No. 4,918,132 describes core-shell polymers for toughening polyester resins. The core-shell poly Merisates were obtained by graft copolymerization of organic vinyl monomers onto crosslinked cores, which are composites of organosilicon compounds and ethylenically unsaturated organic monomers. EP-A 537014 describes impact-modified polycarbonates containing particles with a polysiloxane / organopolymer core and an organic shell.

WO-A 02/36682 and WO-A 02/36683 teach molding compositions of polymethyl methacrylate (PMMA) with improved impact strength at low temperatures. As impact modifiers silicone elastomers are used, which carry a PMMA shell.

A disadvantage of the core-shell polymers is their complex and generally multistage synthesis. In addition, the

Production of the core-shell polymers generally in heterogeneous, aqueous phase, wherein usually a residual moisture remains in the polymerization. The residual moisture can lead to a hydrolytic degradation of the polymer chains when processing the impact modifiers with the thermoplastic polymers, such as polyesters, and thus cause a deterioration of the mechanical properties of molding compositions obtainable therefrom.

Another disadvantage of current impact modifiers based on siloxane polymers is the frequent occurrence of clouding of the thermoplastic polymers in the case of mixing corresponding core-shell polymers, which can be attributed to different refractive indices of the thermoplastic polymers and impact modifiers.

Moreover, there is a need for impact-modified polymer compositions which result in higher impact strength molding compounds than the aforementioned conventional impact-modified polymer compositions.

It was therefore an object to provide impact modifiers which do not have the abovementioned disadvantages and with which molding compounds with high impact resistance become accessible.

Surprisingly, this object has been achieved with organosilicone copolymers having a comb, block or conductor structure.

Organosilicone copolymers have hitherto been used, for example, as coating agents, water repellents or as additives for paints, cosmetics or building chemical products, such as, for example, the organosilicone copolymers based on vinyl esters described in WO-A 03/085035 or DE-A 102005034121 ethylenically unsaturated polyorganosiloxanes. EP-A-0352339 discloses curable coating compositions comprising crosslinkable organosilicone copolymers which are used in addition to

(Meth) acrylate and organosilicone units still contain crosslinkable silane units. EP-A 1375605 discloses organosilicone copolymers as flow control agents for coating compositions wherein the siloxane units of the organosilicone copolymers bear hydroxy-substituted radicals. EP-A 1193303 and DE-A 102006054158 describe crosslinkable coating compositions containing crosslinkable organosilicone copolymers with hydroxy, amino or carboxylic acid groups substituted monomer units.

The invention relates to the use of organosilicone copolymers as toughening modifiers, characterized in that the organosilicone copolymers comprise a) one or more polysiloxane units and b) one or more vinyl polymer units and the units a) and b) covalently with one another are linked to form a comb, block or ladder structure.

Polymers with a comb, block or conductor structure are known to the person skilled in the art. Polymers having a block structure are known to contain at least two different polymer units as repeating units which form a substantially linear chain in a random or defined sequence. In polymers with Comb or ladder structure, the said repeating units form the shape of a comb or a ladder. Thus, in polymers having a comb, block or ladder structure, the individual polymer units are essentially non-crosslinked and have no core-shell structure.

The organosilicone copolymers can be obtained by free-radically initiated substance or solution polymerization of one or more mono- or polyethylenically unsaturated polyorganosiloxanes and one or more ethylenically unsaturated monomers selected from the group comprising (meth) acrylic esters, vinyl esters, vinylaromatics, vinyl ethers , Vinyl halides and olefins.

The preparation of the organosilicone copolymers by means of bulk or solution polymerization is essential to obtain copolymers of comb, block or ladder structure.

Preferred mono- or polyethylenically unsaturated polyorganosiloxanes are those of the general formula (1)

⁽ SiO ₄₇₂ ^{) RR 1} SiO ₃₇₂ ⁾ _m ^(RI 2SiO _2/2 ⁾ p ⁽ R ¹ 3 ^sio l / 2 ⁾ q [O _1/2 SiR ³ ₂ -LX] _s [O _1/2 H] _t ( 1),

in which

L is a bivalent aromatic, heteroaromatic or aliphatic group, optionally mono- or polysubstituted with R 1,

RI, R ^, R ^ each independently represent a hydrogen atom or a monovalent optionally with -CN, -NCO, -NR ² ₂ , -

COOH, -COOR ² , -PO (OR ² ) _{2 /} -halogen, -acryl, -epoxy, -SH, -OH or -CONR ² ₂ substituted hydrocarbon radical with 1 to

20 C atoms or a hydrocarbonoxy radical having 1 to 20 C atoms, in which in each case one or more, non-adjacent methylene units represented by groups -O-, -CO-, -COO-, -OCO-, or -OCOO-, - S-, or -NR ² - and one or more, mutually non-adjacent methine units by Groups -N =, -N = N-, or -P = may be replaced, X is an ethylenically unsaturated radical,

R ^ is hydrogen or a monovalent optionally substituted hydrocarbon radical, s are integer values of at least 1, t 0 or integer values, and the sum of k + m + p + q is an integer value of at least 2.

Preferred radicals R ^, R ^, R3, R4 i _{s n} d, aromatic, or saturated or unsaturated, linear or branched aliphatic specific radicals having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 6 C atoms, where appropriate, a carbon atom may be replaced by an oxygen atom, and wherein the free valencies carry hydrogen atoms. Particularly preferred groups R ^, R ^, R3, R4 i _{s n} d is methyl, ethyl, phenyl and vinyl. The radical R 1 most preferably represents a methyl radical. The radical R 1 most preferably represents a hydrogen atom.

The group L is preferably a methylene, ethylene, propylene or phenylene group or a covalent bond.

The radical X is an ethylenically unsaturated radical having preferably 1 to 20 C atoms, more preferably 1 to 12

C-atoms. For example, the radical X is a vinyl radical, in particular -C 2 H 3, acrylic radical, in particular -OCOC 2 H 3, or a methacrylic radical, in particular -OCOC 2 H 2 CH 3. The

Residues X can be arranged terminally or in the chain of the polyorganopolysiloxanes of the formula (1). Preferably, the

Polyorganopolysiloxanes terminally substituted by 1 or 2 radicals X.

In preferred polyorganosiloxanes of the formula (1), the ethylenically unsaturated groups consisting of the group L and the radical X are bonded via an Si-C bond to a silicon atom of the polyorganosiloxane. s is preferably 1 or 2, more preferably 1.

t is preferably ≦ 10, more preferably 0.

The sum of the values of k, m, p, q, s and t is preferably a number from 3 to 20000, in particular 8 to 1000.

The polyorganosiloxanes of the formula (1) may be cyclic, branched, crosslinked or preferably linear; that is, the poly-organosiloxane of formula (1) is preferably substantially from R2Siθ2 / 2 ~ Ei ⁿ units, particularly preferably solely of

R2Siθ2 / 2 ^{~ au} built. Accordingly, the quotient of p and the sum of k, m, p and q is preferably 0.95 to 1.00.

Examples of polyorganosiloxanes of the formula (1) are α, ω-di-vinyl-polydimethylsiloxanes, α, ω-di- (3-acryloxypropyl) -poly-dimethylsiloxanes, α, ω-di- (3-methacryloxypropyl) polydimethylsiloxanes , α, ω-di- (acryloxymethyl) -polydimethylsiloxanes, α, ω-di- (methacryloxymethyl) -polydimethylsiloxanes, α-monovinyl-polydimethylsiloxanes, α-mono- (3-acryloxypropyl) -polydimethylsiloxanes, α-mono ( 3-methacryloxypropyl) -polydimethylsiloxanes, α-mono- (acryloxymethyl) -polydimethylsiloxanes, α-mono- (methacryloxy-methyl) -polydimethylsiloxanes. Preference is given to α, ω-divinylpoly-dimethylsiloxanes, α-mono- (methacryloxymethyl) -polydimethylsiloxanes or α, ω-di- (methacryloxymethyl) -polydimethylsiloxanes.

Also suitable, however, are polyorganosiloxanes of the formula (1) in which k and / or m are different from zero. Examples of these are polyorganosiloxanes of the formula (1) in which the ratio of the sum of k and m to the sum of k, m, p and q is 0.50 to 1.00, preferably 0.90 to 1.00.

The polyorganosiloxanes of the formula (1) are preferably used at 1 to 90% by weight, more preferably 20 to 75% by weight and most preferably 25 to 70% by weight, based on the total weight of the ethylenically unsaturated polyorganosiloxanes and ethylenically unsaturated monomers for the preparation of organosilicone copolymers. Preferred ethylenically unsaturated monomers from the group of acrylic esters or methacrylic esters are esters of unbranched or branched alcohols having 1 to 15 C atoms. Examples of preferred methacrylic esters or acrylic esters are methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate and Nor - bornyl acrylate. Particularly preferred are methyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, iso-butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, and norbornyl acrylate.

Preferred vinyl esters are vinyl esters of linear or branched monocarboxylic acids having 1 to 15 carbon atoms. Examples of preferred vinyl esters are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate, 1-methylvinyl acetate, vinyl pivalate and vinyl esters of α-branched monocarboxylic acids having 9 to 11 C atoms, for example VeoVa9® or VeoValO® ( Company Resolution). Particularly preferred are vinyl acetate and vinyl esters of α-branched monocarboxylic acids having 9 to 11 carbon atoms, for example VeoVa9® or VeoValO®. Most preferred is vinyl acetate.

Preferred vinyl aromatic compounds are styrene, alpha-methylstyrene, the isomeric vinyltoluenes and vinylxylenes, and divinylbenzenes. Particularly preferred is styrene. Preferred olefins are ethene, propene, 1-alkyl ethenes and polyunsaturated alkenes, such as 1,3-butadiene and isoprene. Particularly preferred are ethene and 1, 3-butadiene. A preferred vinyl ether is methyl vinyl ether. A preferred vinyl halide is vinyl chloride.

Preferred for the preparation of the organosilicone copolymers as ethylenically unsaturated monomers are also mixtures of at least two (meth) acrylic acid esters, such as, for example, n-butyl acrylate and methyl (meth) acrylate; n-butyl acrylate and 2-ethylhexyl acrylate and / or methyl (meth) acrylate; (Meth) acrylic acid and hydroxypropyl (meth) acrylate; or mixtures of styrene and one or more monomers selected from the group consisting of methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate and 2-ethylhexyl acrylate; or mixtures of 1,3-butadiene and styrene and / or methyl (meth) acrylate.

Preferably, from 10 to 99% by weight of ethylenically unsaturated monomers, more preferably from 50 to 80% by weight, based on the total weight of the ethylenically unsaturated polyorganosiloxanes and the ethylenically unsaturated monomers for the preparation of the organosilicone copolymers.

If desired, it is also possible to use from 0.1 to 20% by weight, preferably from 0.1 to 10% by weight, of ethylenically unsaturated auxiliary monomers, based on the total weight of the ethylenically unsaturated monomers, for preparing the organosilicone copolymers. When using one or more auxiliary monomers, preferably 0.5 to 2.5% by weight, based on the total weight of the ethylenically unsaturated monomers for preparing the organosilicone copolymers, are used per auxiliary monomer. Examples of auxiliary monomers are ethylenically unsaturated mono- and dicarboxylic acids, preferably acrylic acid, methacrylic acid, fumaric acid and maleic acid; ethylenically unsaturated carboxylic acid amides and nitriles, preferably acrylamide and acrylonitrile; Mono- and diesters of fumaric acid and maleic acid, such as diethyl and diisopropyl esters and maleic anhydride, ethylenically unsaturated sulfonic acids or salts thereof, preferably vinylsulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid. Further examples are post-crosslinking comonomers, for example acrylamidoglycolic acid (AGA), methyl acrylamidoglycolic acid methyl ester (MAGME), N-methylolacrylamide (NMA), N-methylolmethacrylamide, N-methylolallyl carbamate, alkyl ethers such as isobutoxy ether or esters of N-methylolacrylamide, N-methylolmethacrylamide and of N-methylolallyl carbamate. Also suitable are epoxide-functional ethylenically unsaturated comonomers such as glycidyl methacrylate and glycidyl acrylate. Also mentioned are ethylenically unsaturated monomers having hydroxyl or CO groups, for example methacrylic acid and acrylic acid hydroxyalkyl esters such as hydroxyethyl, hydroxypropyl or hydroxybutyl acrylate or methacrylates and compounds such as diacetoneacrylamide and acetoacetoxyethyl acrylate or methacrylate. Further mention may be made of copolymerizable ethylenically unsaturated silanes, for example vinylsilanes such as vinyltrimethoxysilane or vinyltriethoxysilane or (meth) acrylsilanes, for example GENIOSIL® GF-31 (methacrylate-trimethoxysilane), XL-33 (methacryloxymethyltrimethoxysilane), XL-32 (methacryloxymethyldimethylmethoxysilane), XL-34 (methacryloxymethylmethyldimethoxysilane) and XL-36 (methacryloxymethyltriethoxysilane) (each trade name from Wacker Chemie).

Another object of the invention are (meth) acrylic ester-silicone copolymers with comb, block or conductor structure obtainable by free-radically initiated substance or solution sungspolymerisation of a) one or more (meth) acrylic acid esters, b) a or more or more ethylenically unsaturated polyorganosiloxanes, and optionally c) one or more further ethylenically unsaturated monomers with the proviso proviso that none of the components a) to c) is selected from the group consisting of ethylenically substituted with alkoxy radicals unsaturated silanes, hydroxy-substituted (meth) acrylic esters, hydroxy-substituted (meth) acrylic acid amides, amino-substituted (meth) acrylic esters, unsaturated carboxylic acids, unsaturated carboxylic anhydrides and polyorganosiloxanes which carry radicals having free hydroxy groups.

For the preparation of the (meth) acrylic acid ester silicone copolymers, the same ethylenically unsaturated polyorganosiloxanes and (meth) acrylic acid esters are suitable, preferably and particularly preferred, which are correspondingly listed for the preparation of the organosilicone copolymers and which are the proviso of the (meth) acrylic esters Silicone copolymers meet.

The most preferred (meth) acrylic esters here are methyl (meth) acrylate, n-butyl methacrylate or 2-ethylhexyl acrylate. Further ethylenically unsaturated monomers for preparing the (meth) acrylic ester-silicone copolymers are the same vinyl esters, vinylaromatics, vinyl ethers, vinyl halides or olefins, preferably and particularly preferably, which are correspondingly listed for the preparation of the organosilicone copolymers , and the proviso meet the (meth) acrylic acid ester silicone copolymers.

Ethylenically unsaturated silanes substituted with alkoxy radicals are preferably silicon compounds having a silicon atom bearing at least one radical having an ethylenically unsaturated group and at least one alkoxy radical having from 1 to 20 carbon atoms.

For the preparation of the (meth) acrylic acid ester silicone copolymers, preference is given to using ethylenically unsaturated, alkoxy-substituted silanes and no monomers referred to above as auxiliary monomers. For the preparation of the (meth) acrylic acid ester silicone copolymers, particular preference is given to using no ethylenically unsaturated monomers which are suitable for crosslinking.

For the preparation of the (meth) acrylic ester-silicone copolymers, preferably 1 to 90% by weight, more preferably 30 to 80% by weight, most preferably 40 to 80% by weight and most preferably 45% are preferred used to 80 wt .-% ethylenically unsaturated polyorganosiloxanes, based on the total weight of components a), b) and c) for the preparation of the (meth) acrylic ester-silicone copolymers.

The molecular weight M w of the organosilicone copolymers or of the (meth) acrylic ester-silicone copolymers is preferably from 10,000 to 50,000 g / mol and more preferably from 15,000 to 40,000 g / mol, determined by gel permeation chromatography on polystyrene standards.

The selection of the components and their proportions by weight for the preparation of the organosilicone copolymers or the (meth) acrylic acid ester silicone copolymers is preferably carried out so that in general a glass transition temperature Tg of £ 100 ⁰ C, preferably between -50 ⁰ C and +80 ⁰ C results. The glass transition temperature Tg of the organosilicone copolymers can be determined in a known manner by means of differential scanning calorimetry (DSC). The Tg can also be approximated by the Fox equation. After Fox TG, Bull. Am. Physics Soc. 1, 3, page 123 (1956): l / Tg = xl / Tgl + x2 / Tg2 + ... + xn / Tgn, where xn represents the mass fraction (wt .-% / 100) of the monomer n, and Tg _{n is} the glass transition temperature in Kelvin of the homopolymer of the monomer n. Tg values for homopolymers are listed, for example, in Polymer Handbook 2nd Edition, J. Wiley & Sons, New York (1975).

The preparation of the organosilicone copolymers or of the (meth) acrylic acid ester silicone copolymers takes place by means of free-radical substance or solution polymerization processes of the ethylenically unsaturated components in the presence of radical initiators. In this case, the polymerization products can also be in the form of a dispersion during the polymerization. The solution polymerization is preferred.

Suitable organic solvents are, for example, alcohols having 1 to 6 carbon atoms, such as methanol, ethanol, n-propanol or i-propanol, ketones, such as acetone or methyl ethyl ketone, esters, such as methyl acetate, ethyl acetate, propyl acetate, butyl acetate or methoxypropyl acetate, or aromatic Hydrocarbons having 6 to 15 carbon atoms, such as xylene.

Also suitable are mixtures of several organic solvents, such as, for example, isopropanol / ethyl acetate or methoxypropyl acetate / isopropanol mixtures.

In general, no water is added as the solvent component for the polymerization. The content of water is preferably <10% by weight, more preferably <1% by weight and most preferably ≦ 0.01% by weight, based in each case on the total mass of the organic solvents used. The individual components for the preparation of the organosilicone copolymers are, under normal conditions according to DIN50014, soluble in the solvents or mixtures of several organic solvents, preferably at least 1% by weight, more preferably at least 10% by weight.

The polymerization is preferably carried out at temperatures from 0 ^° C. to 150 ^° C., preferably from 20 ^° C. to 130 ^° C., more preferably from 30 ^° C. to 120 ^° C. The polymerization can be carried out batchwise or continuously, with the introduction of all or individual constituents of the reaction mixture, with partial introduction and subsequent addition of individual components of the reaction mixture or after the metering process without presentation. All dosages are preferably carried out in proportion to the consumption of the respective component. Particular preference is given to a polymerization in which the silicone building blocks are initially charged and the other reactive constituents of the polymerization are metered in.

The initiation of the polymerization takes place by means of the usual initiators or redox initiator combinations. Examples of initiators are the sodium, potassium and ammonium salts of peroxodisulfuric acid, hydrogen peroxide, t-butyl peroxide, t-butyl hydroperoxide, potassium peroxodiphosphate, t-butyl peroxypivalate, cumene hydroperoxide, t-butyl peroxobenzoate, isopropylbenzene monohydroperoxide and azobisisobutyronitrile. The initiators mentioned are preferably used in amounts of from 0.01 to 4.0% by weight, based on the total weight of the monomers used for the preparation of the organosilicone copolymers. The redox initiator combinations used are the abovementioned initiators in conjunction with a reducing agent. Suitable reducing agents are sulfites and bisulfites of monovalent cations, for example sodium sulfite, the derivatives of sulfoxylic acid, such as zinc or alkali metal formaldehyde sulfoxylates, for example sodium hydroxymethanesulfinate and ascorbic acid. The amount of reducing agent is preferably 0.15 to 3 wt .-% of used monomers for the preparation of organosilicone copolymers.

In addition, small amounts of a metal compound which is soluble in the polymerization medium and whose metal component is redox-active under the polymerization conditions, for example based on iron or vanadium, can be introduced. Especially before ^¬ ferred initiators are t-butyl peroxopivalate, and benzoate t-Butylperoxo-, and the peroxide / reducing agent combinations ammonium persulfate / sodium and Kaliumpersul ^¬ fat / sodium. An overview of other suitable initiators in addition to the representatives just described can be found in the "Handbook of Free Radical Initiators", ET Denisov, TG Denisova, TS Pokidova, 2003, Wiley Verlag

The isolation of the organosilicone copolymers from the solvent after polymerization can be effected by removal of the solvent by distillation, by precipitation and filtration of the organosilicone copolymers by addition of a non-solvent, by decantation or by a combination of these methods. The organosilicone copolymers according to the invention are present in iso ^¬ lierter form generally in the form of a solid or a high viscosity oil. Preferably, the organosilicone copolymers are optically transparent.

Another object of the invention are impact-ed polymer compositions containing one or more organosilicone copolymers, one or more thermoplastic poly ^¬ mers and optionally one or more additives, characterized indicates overall that the organosilicone copolymers a) one or more polysiloxane units and b) one or more vinyl polymer units and the units a) and b) are covalently linked together to form a comb, block or ladder structure.

Suitable thermoplastic polymers are, for example, polyolefins, such as polyethylene, polypropylene, polystyrene, polyamides, polyvinyl halides, such as polyvinyl chloride, polyoxymethylene, polyalkylene polycarbonates, poly (meth) acrylic esters, such as polymethyl methacrylate, aromatic polyesters, such as polyalkylene terephthalates, aliphatic polyesters, such as polyhydroxybutyric acid, polycaprolactone or polylactic acid.

Other additives for the impact-modified polymer compositions may include, for example, fibrous reinforcing materials (glass fibers, carbon fibers, chemical fibers such as polyester or polyamide, natural fibers such as cotton or cellulose), mineral fillers such as chalk, clays, pigments, dyes, stabilizers, flame retardants and other other polymers be used.

In the toughened polymer compositions, the proportion of the organosilicone copolymers is preferably from 2 to 50% by weight, more preferably from 5 to 40% by weight, based on the total weight of the impact modified polymer composition.

In an alternative embodiment, the organosilicone copolymers may be attached to the thermoplastic polymers via covalent bonds. As a result, inter alia, a separation of the components of the impact-modified polymer compositions can be counteracted and thus the storage stability of the impact-modified polymer compositions can be increased. Such bonds occur, for example, when using organosilicone copolymers containing one or more units of auxiliary monomers, such as hydroxyethyl (meth) acrylate, hydroxypropyl methacrylate or (meth) acrylsilanes for toughening of thermoplastic polymers such as polyesters.

The production of the impact-modified polymer compositions is carried out by customary processes by processing one or more thermoplastic polymers, one or more organosilicone copolymers and optionally further additives, for example in roll kneaders or extruders. Here, the thermoplastic polymer, for example in the form of a Granules are mixed with the organosilicone copolymer and optionally further additives, melted and thereby mixed. Likewise, the thermoplastic polymer, the organosilicone copolymer and optionally other additives can be melted separately and then blended. Preferably, the mixing is carried out under high shear, whereby a particularly homogeneous mixture of the components can be achieved.

The mixing temperature and mixing time depend on the properties of the respective components of the impact-modified polymer compositions and are usually chosen so that a homogeneous distribution of the components is ensured and the thermal stress on the composition is kept as low as possible.

The impact-modified polymer compositions can then be further processed thermoplastically directly in the form of their melt. Alternatively, the mixture can be converted into a granulate which can be thermoplastically processed at a later time.

Another object of the invention are molding compositions obtainable by thermoplastic deformation of impact-modified polymer compositions.

For thermoplastic forming, the processes known to the person skilled in the art can be used, such as, for example, injection molding, extrusion, pressing or thermoforming.

In the impact modified polymer compositions of the invention, the thermoplastic polymer is typically present as a continuous phase in which the organosilicone copolymers are dispersed as discontinuous phases (domains). The domains preferably have a diameter of from 10 to 10,000 nm, more preferably from 10 to 100 nm, most preferably from 10 to 250 nm and most preferably from 10 to 40 nm. The size of the domains according to the invention has an effect advantageous for the production of transparent impact-modified polymer compositions or molding compositions. Alternatively, the organosilicone copolymers in the toughened polymer compositions can form the continuous phase. In this case, the thermoplastic polymer is in the form of domains as a discontinuous phase.

Repeated melting of the impact-modified polymer compositions typically does not result in segregation of the continuous and discontinuous phases.

The molding compositions containing organosilicone copolymers have high impact strengths, in particular also high low-temperature impact toughness, and high impact strengths. The use of the organosilicone copolymers does not lead to turbidity of the impact-modified polymer compositions or molding compositions. Impact-modified polymer compositions with little or no residual water content are accessible according to the invention, so that hydrolytic degradation can be ruled out during further processing. In addition, the organosilicone copolymers are fire retardant in the impact modified polymer compositions and the molding compositions. On the weathering and aging resistance and the temperature stability of molding compositions, the organosilicone copolymers also have an advantageous effect.

The following examples are given to illustrate the invention in detail and are in no way to be considered as limiting.

Examples

Synthesis of Organosilicone Copolymers

Examples Ia-If:

30 parts by weight of the respective polyorganosiloxane (Table 1) were dissolved in 390 parts by weight of methoxypropyl acetate and dissolved in a jacketed jacketed reactor with additional sieves. Cooling and an anchor agitator under nitrogen atmosphere to 120 ⁰ C heated. Then 0.5 parts by weight of tert-butyl peroxybenzoate dissolved in 10 parts by weight of methoxypropyl acetate were added within 4 hours. The dosage of the monomers (Table 1) was started simultaneously and took place for 2 hours. After initiator dosing another 0.2 parts by weight of radical initiator were metered intermittently. It was stirred for one hour at 120 ⁰ C.

Subsequently, the solvent was completely removed under reduced pressure. The respective organosilicone copolymer was obtained in the form of a transparent solid.

Table 1: Composition and structure of the organosilicone copolymers of Examples Ia to Ig:

a) BMA: n-Butylmethacrylat; MMA: Methylmethacrylat; MAS :Methacrylsaure; HPMA: Hydroxypropylmethacrylat . b) MA-PDMSl: α-Methacryloxymethylpolydimethylsiloxan mit Mn 3000 g/mol; MA- PDMS2 : α-Methacryloxymethylpolydimethylsiloxan mit Mn 1000 g/mol; X-PDMS- X: lineares α,ω-Dibrompropionyl-polydimethylsiloxan 1200 g/mol; MA-PDMS- MA: lineares α,ω-Bis- (Methacryloxymethyl) polydimethylsiloxan mit Mn 3000 g/mol .

a) BMA: n-butyl methacrylate; MMA: methyl methacrylate; MAS: methacrylic acid; HPMA: hydroxypropyl methacrylate. b) MA-PDMSl: α-methacryloxymethylpolydimethylsiloxane with Mn 3000 g / mol; MA-PDMS2: α-methacryloxymethylpolydimethylsiloxane with Mn 1000 g / mol; X-PDMS-X: linear α, ω-dibromopropionyl-polydimethylsiloxane 1200 g / mol; MA-PDMS-MA: linear α, ω-bis (methacryloxymethyl) polydimethylsiloxane with Mn 3000 g / mol.

Example Ig 20 parts by weight of the polyorganosiloxane (Table 1) and 80 parts by weight of the previously purified by distillation monomer (Table 1) were charged in 100 parts by weight of xylene. The Solution was freed three times by applying a vacuum and embroidering oxygen. Subsequently, Cu (I) Br and PMDETA (pentamethyl) was added and the reaction mixture for 6h at 100 ⁰ C. The mixture was then filtered from insoluble catalyst and the organosilicon copolymer was precipitated by addition of 500 parts by weight of methanol, isolated and dried.

Production of Impact-modified Polymer Compositions and Molding Compositions and Determination of Impact Strengths:

The thermoplastic polymer of polylactic acid (manufacturer. Na tureWorks, Type PLA4032D) was dissolved in a roll kneader (Rheomix OS 3000, Fa. Thermo-Fisher Scientific), where appropriate with the respective impact modifier (Table 2) mixed with at a temperature of 180 ⁰ C. 20 U / min processed for 20 min to an optionally impact-modified polymer composition.

From the impact-modified polymer compositions of Comparative Examples 2 to 4 and Examples 5 to 11 respectively, according to DIN EN ISO 19-IeC standard-compliant test specimens, i. Molding compositions prepared on the basis of which the notched impact strength according to DIN EN ISO 19-IeC was determined. The molding compositions thus obtained were transparent.

From the data in Table 2 impact toughness and fracture pattern shows that the molding compositions according to the invention (Table 2, Examples 4, 8 to 10) have similar or even far better properties than conventional impact modifier molding compositions (Table 2, Comparative Examples 2 and 3).

An essential advantage of the procedure according to the invention is that the impact modifiers according to the invention, ie the silicone organocopolymers, are obtained by simple copolymerization of the individual ethylenically unsaturated monomers and the polyorganosiloxanes, whereas the preparation of Core-shell copolymers is expensive.

In the case of the molding compositions of Examples 5 to 8, 10 and 11 (Table 2), toughening modifiers were used with the (meth) acrylic ester-silicone copolymers, which exclusively contain inexpensive methacrylic acid ester monomer units and are therefore of particular economic interest.

Table 2: Impact-modified polymer compositions and testing of corresponding molding materials:

a) Angabe in Gew.-% bezogen auf das Gewicht des thermoplastischen Polymers Polymilchsaure . b) bestimmt nach DIN EN ISO 19-leC. c) bestimmt mittels Transmissionselektronenmikroskopie d) Kern-Schale-Siliconacrylat der Firma Mitsubishi-Rayon e) Kern-Schale-Siliconacrylat der Firma Wacker Chemie

a) in wt .-% based on the weight of the thermoplastic polymer polylactic acid. b) determined according to DIN EN ISO 19-leC. c) determined by means of transmission electron microscopy d) core-shell silicone acrylate from Mitsubishi Rayon e) core-shell silicone acrylate from Wacker Chemie

Claims

Claims: 1. The use of organosilicone copolymers as impact modifiers, characterized in that the organosilicon copolymers a) one or more polysiloxane units and b) one or more vinyl polymer units and the units a) and b) covalently so that they form a comb, block or ladder structure. 2. Use of organosilicone copolymers according to claim 1, characterized in that the organosilicone copolymers are obtained by free-radically initiated substance or solution polymerization of one or more mono- or polyunsaturated ethylenically unsaturated polyorganosiloxanes and one or more ethylenically unsaturated monomers selected from the group comprising (Meth) acrylic esters, vinyl esters, vinyl aromatics, vinyl ethers, vinyl halides and olefins. 3. Use of organosilicone copolymers according to claim 2, characterized in that ethylenically unsaturated polyorganosiloxanes of the general formula (1) (SiO ₄₇₂ ) _k (R ¹ SiO ₃₇₂ ) _m (Ri ₂ SiO ₂ Z ₂ ) p (R ¹ SSiO ₁₇₂ ) _q [O _1/2 SiR ³ ₂ -L x] _s [O _l72 H] _t (1) be used, where L is a divalent aromatic, heteroaromatic or aliphatic, optionally containing one or multiple sub ^{¬-substituted} with R ^ group, R ^1, R ^, R ^ are each independently a hydrogen atom or a monovalent optionally substituted with -CN, -NCO, -NR ² ₂ , -COOH, -COOR ² , -PO (OR ² ) ₂ ^ -halogen, -acrylic, -epoxy, -SH, -OH or -CONR ² ₂ substituted hydrocarbon radical with 1 to 20 C atoms or a Kohlenwasserstoffoxyrest with 1 to 20 C-atoms, in which in each case one or more, non-adjacent methylene units by groups -0-, -CO-, -COO-, -OCO-, or -OCOO -, -S-, or -NR ² - and one or more, mutually non-adjacent methine units by groups -N =, -N = N-, or -P = may be replaced, X is an ethylenically unsaturated radical, R ^{2 is} hydrogen or a monovalent, optionally substituted hydrocarbon radical, s are integer values of at least 1, t 0 or integer values, and the sum of k + m + p + q is an integer value of at least 2. 4. Use of organosilicone copolymers according to claim 2 or 3, characterized in that as polyorganosiloxanes ne α, ω-divinyl-polydimethylsiloxanes, α, ω-di- (3-acryloxypropyl) polydimethylsiloxanes, α, ω-di- ( 3-methacryloxypropyl) -polydimethylsiloxanes, α, ω-di- (acryloxymethyl) -polydimethylsiloxanes, α, ω-di- (methacryloxymethyl) -polydimethylsiloxanes, α-monovinyl-polydimethylsiloxanes, α-mono- (3-acryloxypropyl) polydimethylsiloxanes, α-mono- (3-methacryloxypropyl) -polydimethylsiloxanes, α-mono- (acryloxymethyl) -polydimethylsiloxanes or α-mono- (Methacryloxymethyl) polydimethylsiloxanes are used. 5. Use of organosilicone copolymers according to claim 2 to 4, characterized in that the polyorganosiloxanes are used to 1 to 90 wt .-%, based on the total weight of the ethylenically unsaturated polyorganosiloxanes and the ethylenically unsaturated monomers for the preparation of organosilicone copolymers. 6. Use of organosilicone copolymers according to claim 2 to 5, characterized in that the free-radically initiated polymerization in an alcohol with 1 to 6-C atoms, ketone, ester or aromatic hydrocarbon having 6 to 15 carbon atoms is carried out. 7. (meth) acrylic ester-silicone copolymers with comb, block or conductor structure obtainable by free-radically initiated substance or solution polymerization of a) one or more (meth) acrylic esters, b) one or more mono- or polyunsaturated ethylenically unsaturated polyorganosiloxanes and optionally c) one or more further ethylenically unsaturated monomers with the proviso that none of components a) to c) is selected from the group comprising ethylenically unsaturated silanes substituted by alkoxy radicals, hydroxy-substituted (meth ) acrylic acid esters, hydroxy-substituted (meth) acrylic acid amides, amino-substituted (meth) acrylic acid esters, unsaturated carboxylic acids, unsaturated carboxylic anhydrides and polyorganosiloxanes which carry radicals having free hydroxy groups. 8. Impact-modified polymer compositions containing one or more organosilicone copolymers, one or meh ^¬ eral thermoplastic polymers and optionally one or more additives, characterized in that the organo sili con-Copo l Ymere a) one or more polysiloxane units and b) contain one or more vinyl polymer units and the units a) and b) are covalently linked together so that they form a comb, block or conductor structure. 9. impact-modified polymer compositions according to claim 8, characterized in that as thermoplasti ^¬ cal polymers polyolefins, polystyrene, polyamides, Polyvi- nylhalogenide, polyoxymethylene, polycarbonates, poly- Iy (meth) acrylic esters, aromatic polyesters, aliphatic polyesters, polycaprolactone or polylactic acid can be used. 10. Molding compositions obtainable by thermoplastic transformation of impact-modified polymer compositions according to claim 8 or 9.