WO2011045122A1

WO2011045122A1 - Polymer particles

Info

Publication number: WO2011045122A1
Application number: PCT/EP2010/063138
Authority: WO
Inventors: Sabine Schwarz-Barac; Michael Schnabel; Thorsten Goldacker; Klaus Schultes
Original assignee: Evonik Röhm Gmbh
Priority date: 2009-10-13
Filing date: 2010-09-08
Publication date: 2011-04-21
Also published as: DE102009045632A1; TW201129586A

Abstract

The invention relates to polymer particles, comprising cross-linked polymer particles that are enveloped by a matrix polymer, wherein i.) the cross-linked polymer particles can be obtained by way of radical polymerization of a monomer mixture, the cross-linked polymer particles comprising, in relation to the total weight, a. 90.00 wt.-% to 99.99 wt.-% of at least one monoethylenically unsaturated monomer, and b. 0.01 wt.-% to 10.00 wt.-% of at least one polyunsaturated monomer, ii) the matrix polymer can be obtained by way of radical polymerization of at least one monoethylenically unsaturated monomer, iii.) the cross-linked polymer particles are insoluble in the matrix polymer, wherein I.) the mean particle size of the cross-linked polymer particle ranges from 0.9 µm to 6.0 µm, II.) the mean particle size of the enveloped polymer particles ranges from 50 µm to 300 µm, III.) the difference of the refractive index of the cross-linked polymer particles and the refractive index of the matrix polymer, which are each measured at 20°C, is at least 0.01.

Description

polymer particles

The present invention relates to polymer particles which are preferably used for the matting of molding compositions, in particular of polyalkyl (meth) acrylate-containing molding compositions, and give them a light-scattering effect.

For lighting and lighting applications, outlets and cosmetic sales stands, there is a constant demand for new and innovative products that are as visually appealing as possible and at the same time can be produced as cheaply as possible. In particular, a plastic product with high transparency, matt is desirable

Appearance and structured

Surface texture.

The preparation of such materials in a conventional manner, for. B. by adding inorganic filling and

Additives, such as barium sulfate, calcium carbonate,

Titanium dioxide, silicon dioxide, etc., is only partially suitable for this purpose. The inorganic fillers can usually only be dispersed uniformly uniformly within a polymer matrix. In addition, these sit down

As a result, inorganic fillers often degrade during polymerization due to their high density, and consequently do not give uniform results and often adversely affect the physical properties of the material produced. Furthermore, they greatly reduce the

Translucency of the polymer and other physical properties of the plastic to unacceptable levels.

It is also known that organic matting agents such. As polystyrene, instead of the above

inorganic agents can be used and give better opacity at high light transmission values. The disadvantage, however, is the poor weatherability and, as a consequence, an increase in the yellowness index and its high level of yellowing

Price.

Furthermore, the incorporation of such matting agents in the molding compound to be matted is problematic. It requires special equipment to break up cracks, dosing problems and possibly dust explosions, especially finely divided

To avoid particles that are comparatively small

Have ignition energies.

In addition, better properties of the resulting molding compositions, in particular improved mechanical

Properties, desirable.

The patent US 4,876,311 suggests the use of an opaque synthetic resin composition containing 1-30% by weight of crosslinked beads. The beads should be made of a polymer

(i) 9, 9 - 59.9 wt .-% of at least one free radical

polymerizable monomer containing an aromatic group or a non-aromatic monomer containing a halogen,

(ii) 90-40% by weight of vinylic monomers containing these

are copolymerizable but different from them,

(iii) 0.1-20% by weight of at least one crosslinking agent

Monomers and

(iv) 0-10% by weight of a highly polar monomer.

Furthermore, the refractive index of the polymer should be greater than that of the polymer matrix and the mean particle size of the beads should be in the range of 20 μm-50 μm.

The resin composition is extruded into the desired moldings. However, these beads are comparatively small,

shear sensitive and thermolabile. They are therefore difficult to process. In production you always have

To fight contaminations. Furthermore, there is the risk of electrostatic charging and the formation of possibly

respirable dusts. A waiver of the finely divided scattered beads for matted products would be advantageous.

The patent EP 1 022 115 describes extruded articles which have a matt and textured surface. In order to achieve this effect, light-scattering pearls with a refractive index offset to the matrix of> 0.02

used. The weight average particle size of the beads should be in the range of

25 ym - 55 ym lie and the particles should be one

Particle size distribution in the range of 10 ym - have 110 ym. The special surface effect comes supposedly only through the use of pearls with exactly this

Particle size distribution concluded.

DE 2146628 A teaches the use of crosslinked

Polymer particles which are encased by a matrix polymer which is to be homogenized during compounding in the thermoplastic to be matted, while the

crosslinked polymer particles should then act as matting agents.

As a matrix polymer are thermoplastic homo- and

Mixed polymers having molecular weights in the range of about 20,000 to 200,000 g / mol used. Polyacrylic resins, such as copolymers of methyl methacrylate, are used in these

Called context among others. The crosslinked polymer particles are made of an ethylenically unsaturated monomer, such as. As styrene, constructed. They are used with 0.01 wt .-% to 3.0 wt .-% of a multiple

unsaturated monomers, such as. B. a Diacrylester of glycol, crosslinked as a primary crosslinker. Furthermore, the polymer particles preferably become a secondary crosslinking or latent crosslinking by means of reactive groups

subjected.

The preparation of the crosslinked polymer particles takes place by means of endopolymerization, by dissolving the matrix polymer in a monomer and subsequently the monomer

polymerized, wherein the newly formed polymer and the matrix polymer segregate during the polymerization due to their incompatibility. In this way one becomes

Obtained polymer product which comprises the matrix polymer as a quasi-continuous phase in which the newly formed crosslinked end-polymerisate is dispersed.

The endopolymerization can be different

Procedure done. Substance, suspension and emulsion polymerization are explicitly mentioned, with the

Bulk polymerization is particularly preferred.

After the final polymerization, the resulting product is optionally granulated, mixed with further matrix polymer and processed together.

The size of the enclosed endopolymers should be in the range of 0.5 .mu.m to 30 .mu.m. These values were determined by light microscopy.

Statements on the thermostability of the molding compositions and / or the resulting moldings are not apparent from the document. Example 1 describes the matting of a polymethacrylate co-ethyl acrylate (85/15). The matrix polymer used is a polymer of the same composition. The crosslinked polymer particles are obtained by endopolymerization in bulk, wherein the monomer mixture styrene (96.65 wt .-% based on all monomers), glycidyl methacrylate (1.96 wt .-% based on all monomers), methacrylic acid (1.29 wt. % based on all monomers) and butylene diacrylate (0.10% by weight based on all monomers). After the polymerization, the product is granulated and added together with the

matting thermoplastics coextruded. The size of the granulated polymer particles is given as less than 7.938 mm.

The properties of further finely divided polymer mixtures are described in Example 7. The soluble polymer comprises from 87% to 90% by weight of methyl methacrylate units and from 10% to 13% by weight of ethyl acrylate units. The crosslinked particles comprise styrene units and optionally 87% by weight of butyl acrylate units. You have one

Size range from 5 ym to 80 ym and an average size ranging from 5 ym to 40 ym. The concentration of cross-linked particles is between 50 and 80%.

Polymer particles comprising a crosslinked end copolymer in a matrix polymer are also described in DE 2439542 A

described. They serve to modify the surface of thermoplastic polymers, in particular to reduce surface gloss and matting.

Statements on the thermostability of the molding compositions and / or the resulting moldings, however, are also this

Reference not to be taken. In Example 1, a final polymerization is shown in substance. The matrix polymer used is a polymethacrylate-co-ethyl acrylate (91/9). The monomer mixture for the final copolymer comprises styrene (61.83% by weight, based on all monomers), n-butyl methacrylate (32.84% by weight, based on all monomers), ethyl acrylate (3.88% by weight, based on all monomers) Monomers) and allyl methacrylate (1.45% by weight based on all monomers). After the polymerization, the product becomes

granulated. The size of the granulated

Polymer particles specified with less than 8 mm. The

Endopolymer particles should have a size in the range from 1 μm to 35 μm and a mean size of 1.5 μm, determined by means of electron microscopy.

The use of the product of Example 1 as an additive for polyvinyl chloride is described in Example 2.

Example 6 describes a suspension end-polymerization. The matrix polymer used is a polymethacrylate-co-ethyl acrylate (90/10). The monomer mixture for the final copolymer comprises styrene (59.74% by weight, based on all monomers), n-butyl methacrylate (33.41% by weight, based on all monomers), ethyl acrylate (3.84% by weight, based on all monomers) Monomers) and allyl methacrylate (3.01 wt.% Based on all monomers). The size of the resulting polymer particles is reported as 1080 ym to 2160 ym. The endopolymer particles should have a size in the range from 1 .mu.m to 33 .mu.m and a mean size of 6 .mu.m, determined by means of

Electron microscopy.

However, a detailed description of the electron microscopy is not apparent from the document. Furthermore, endopolymers are meanwhile also commercially available. So z. B. Acematt OP 278 (product of Evonik Degussa GmbH) a two-phase polymer by

Endopolymerization can be produced. The matrix is made up of approx. 150 ym pearls that are made from

Polymethyl methacrylate (PMMA) exist. In these beads fine beads of a crosslinked copolymer of styrene and n-butyl acrylate are embedded. The diameter of the fine

Pearls is according to the product data sheet about 7 ym.

A disadvantage of the solutions discussed above, however, is the relatively large amount of scattering beads or

Endopolymers needed to achieve the desired scattering effect. It will be more efficient

Matting agents, in particular for polymethyl methacrylate-based molding compositions, desired.

For example, Acematt OP 278 is not suitable for the matting of polymethylmethacrylate, in particular Plexiglas 7N, since there is no increase in the intensity half-value angle. Acematt is according to the product data sheet

especially for the matting of PVC films.

Furthermore, an improvement in the properties of the resulting molding compositions and moldings, in particular in terms of their mechanical properties and their thermal stability is desirable.

In view of this prior art, it was an object of the present invention to provide better opportunities for

Production of molding compounds with dull and structured surface show that have as much as possible an improved property profile. Thus, in particular a matting agent was sought, which is the molding material frosted as effectively as possible, in addition as light-scattering as possible and in particular leads to the most effective increase of the intensity half-value angle. At the same time, the highest possible homogeneity of the material properties should be achieved. Inhomogeneities and optical defects, such. B. specks, should after

Possibility to be avoided. In addition, were

the best possible mechanical properties desired.

In particular, the roughness of the moldings should after

Possibility to be improved. Furthermore, a solution was sought, which can be realized on a comparably simple way on a large scale and inexpensively.

These as well as other tasks that are not specified in concrete terms, but which arise in a concise manner from the contexts discussed at the beginning, are explained by

Polymer particles with all the features of the present patent claim 1 solved. The dependent claims referred to claim 1 describe particularly expedient

Modifications of the polymer particles. Furthermore, particularly advantageous fields of application of the invention

Protected polymer particles.

By providing polymer particles comprising crosslinked polymer particles derived from a

Matrix polymer are coated, wherein

i.) the crosslinked polymer particles by free radical

Polymerization of a monomer mixture are available, which, based on their total weight,

a. 90.00 wt .-% to 99.99 wt .-% of at least one monoethylenically unsaturated monomer and

b. From 0.01% by weight to 10.00% by weight of at least one polyunsaturated monomer, ii. ) the matrix polymer is obtainable by radical polymerization of at least one monoethylenically unsaturated monomer,

iii. ) the crosslinked polymer particles are insoluble in the matrix polymer,

iv. ) the average particle size of the crosslinked

Polymer particles in the range of 0.9 ym to 6.0 ym, v. ) the mean particle size of the coated

Polymer particles in the range of 50 ym to 300 ym, vi. ) the difference of the refractive index of the crosslinked

Polymer particles and the refractive index of the

Matrix polymer, measured at 20 ° C., is at least 0.01,

succeeds in not easily foreseeable way to show a possibility for the production of molding compounds with dull and structured surface, which have a very good property profile. This is how it is

Matting agent provided which matts the molding compound extremely effective and also extremely

light scattering acts, in particular a very high

Luminous efficacy shows and leads to a very effective increase of the intensity half-value angle. The loss due to re-radiation is significantly lower than with conventional matting agents and the scattering effect is significantly higher.

Accordingly, the amount of litter additives can be reduced, which in turn reduces costs and conserves resources.

At the same time a very high homogeneity of the

Material properties achieved. Inhomogeneities and optical defects, such. B. specks are not observed. In addition, the moldings according to the invention have very good mechanical properties, very good roughness and significantly improved weather resistance. The preparation of the molding according to the invention with matt and structured surface finish can be produced in a comparably simple manner on an industrial scale and inexpensively by shaping a composition,

containing at least one polymer to be matted and one or more polymer particles according to the invention.

Another advantage of the polymer particles according to the invention lies in the processability. Due to their size, they can be processed much more easily than conventional matting agents, since the finely divided scattering particles are only released when compounded.

Dosing problems do not occur and there is no danger of a dust explosion.

The polymer particles of the invention comprise

Polymer particles coated by a matrix polymer. They are preferably present as end-polymer particles.

The polymer particles are within the scope of the present invention

Networked invention.

In this context, "crosslinked" means that the particles are only in small amounts in a strong organic

Solvent, such as tetrahydrofuran (THF), can be solved. Here, "small amount" means that the

polymer-soluble fraction is at most 7% by weight, based on the total weight of those used in the measuring method

Particle. The polymer-soluble portion becomes as follows

certainly :

The polymer particles are dissolved in THF and heated at 21,000 rpm for 3 hours. centrifuged. 15 ml of the supernatant are withdrawn and refilled with approx. 15 ml of THF. This is repeated 3 times. The withdrawn supernatant is filtered through a 0.45 μιη membrane filter, then reduced to 60 mL and again centrifuged for 3 hours. After centrifugation, the supernatant is evaporated and analyzed by NMR and GC-MS.

The matrix polymer, on the contrary, is preferably not crosslinked. In this context, "non-crosslinked" means that the matrix polymer can essentially be dissolved in a strong organic solvent, such as tetrahydrofuran (THF), where "substantially" means that the polymer-soluble fraction is more than 7% by weight, based on the total weight of the particles used in the measurement method. The polymer-soluble portion becomes as before

describe definitely.

The crosslinked polymer particles are free-radical

Polymerization of a monomer mixture, which, based on their total weight,

a. 90.00% by weight to 99.99% by weight, preferably 95.00% by weight to 99.95% by weight, preferably 97.00% by weight to 99.90% by weight, in particular 98.00 wt .-% to 99.50 wt .-%, of at least one monoethylenically unsaturated monomer and

b. From 0.01% by weight to 10.00% by weight, preferably from 0.05% by weight to 5.00% by weight, preferably from 0.10% by weight to 3.00% by weight, in particular from 0.5% to 2.00% by weight, of at least one polyunsaturated monomer.

The monoethylenically unsaturated monomers are in principle not subject to further restrictions and include u. a. (Meth) acrylates, fumarates and maleates derived from saturated alcohols, such as

Methyl (meth) acrylate, ethyl (meth) acrylate,

n-propyl (meth) acrylate, iso-propyl (meth) acrylate,

n-butyl (meth) acrylate, tert-butyl (meth) acrylate,

Pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate,

2-tert. Butylheptyl (meth) acrylate, octyl (meth) acrylate, 3-iso-propylheptyl (meth) acrylate, nonyl (meth) acrylate,

Decyl (meth) acrylate, undecyl (meth) acrylate,

5-methylundecyl (meth) acrylate, dodecyl (meth) acrylate,

2-methyldodecyl (meth) acrylate, tridecyl (meth) acrylate,

5-methyltridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate,

2-methylhexadecyl (meth) acrylate, heptadecyl (meth) acrylate, 5-isopropylheptadecyl (meth) acrylate,

4-tert. Butyl octadecyl (meth) acrylate,

5-ethyloctadecyl (meth) acrylate,

3-iso-propyloctadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate,

Cetyleicosyl (meth) acrylate, Stearyleicosyl (meth) acrylate, docosyl (meth) acrylate and / or Eicosyltetratriacontyl- (meth) acrylate;

Cycloalkyl (meth) acrylates, such as cyclopentyl (meth) acrylate, 2,4,5-tri-t-butyl-3-vinylcyclohexyl (meth) acrylate,

2,3,4,5-tetra-t-butylcyclohexyl (meth) acrylate;

Cycloalkyl (meth) acrylates, such as

3-vinylcyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate; as well as the corresponding fumarates and maleates;

Vinyl halides, such as vinyl chloride,

Vinyl fluoride, vinylidene chloride and vinylidene fluoride;

Vinyl esters, such as vinyl acetate;

Styrene, substituted styrenes having an alkyl substituent in the side chain, such as. B. α-methylstyrene and

a-ethylstyrene, substituted styrenes with a

Alkyl substituents on the ring, such as vinyl toluene and p-methylstyrene, halogenated styrenes, such as Monochlorostyrenes, dichlorostyrenes, tribromostyrenes and

Tetrabromostyrenes;

Heterocyclic vinyl compounds, such as 2-vinylpyridine, 3-vinylpyridine, 2-methyl-5-vinylpyridine, 3-ethyl-4-vinylpyridine, 2, 3-dimethyl-5-vinylpyridine, vinylpyrimidine, vinylpiperidine, 9-vinylcarbazole, 3-vinylcarbazole,

4-vinylcarbazole, 1-vinylimidazole, 2-methyl-1-vinylimidazole, N-vinylpyrrolidone, 2-vinylpyrrolidone, 3-vinylpyrrolidine, N-vinylcaprolactam, N-vinylbutyrolactam, vinyloxolane,

Vinylfuran, vinyloxazoles and hydrogenated vinyloxazoles;

Vinyl and isoprenyl ethers;

Maleic acid and maleic acid derivatives such as maleic anhydride, methylmaleic anhydride, maleimide, methylmaleimide;

Fumaric acid and fumaric acid derivatives;

Acrylic acid and methacrylic acid;

Aryl (meth) acrylates, such as benzyl methacrylate or

Phenylmethacrylate, wherein the aryl radicals in each case

unsubstituted or substituted up to four times;

Methacrylates of halogenated alcohols, such as 2,3-dibromopropyl methacrylate,

4-bromophenyl methacrylate, 1, 3-dichloro-2-propyl methacrylate, 2-bromoethyl methacrylate, 2-iodoethyl methacrylate,

Chloromethyl methacrylate;

Hydroxyalkyl (meth) acrylates, such as 3-hydroxypropyl methacrylate,

3, 4-dihydroxybutyl methacrylate, 2-hydroxyethyl methacrylate,

2-hydroxypropyl methacrylate, 2, 5-dimethyl-1,6-hexanediol (meth) acrylate,

1, 10-decanediol (meth) acrylate;

carbonyl-containing methacrylates, such as 2-carboxyethylmethacrylate, carboxymethylmethacrylate, oxazolidinylethylmethacrylate, N- (Methacryloyloxy) formamide, acetonyl methacrylate, N-methacryloylmorpholine, N-methacryloyl-2-pyrrolidinone, N- (2-methacryloyloxyethyl) -2-pyrrolidinone, N- (3-methacryloyloxypropyl) -2-pyrrolidinone, N- (2-methacryloyloxypentadecyl) 2-pyrrolidinone, N- (3-methacryloyloxyheptadecyl) -2-pyrrolidinone;

Methacrylates of ether alcohols, such as

Tetrahydrofurfurylmethacrylate,

Methoxyethoxyethyl methacrylate, 1-butoxypropyl methacrylate, cyclohexyloxymethyl methacrylate,

Methoxymethoxyethyl methacrylate, benzyloxymethyl methacrylate, furfuryl methacrylate, 2-butoxyethyl methacrylate, 2-ethoxyethoxymethyl methacrylate, 2-ethoxyethyl methacrylate, 1-ethoxybutyl methacrylate, methoxymethyl methacrylate, 1-ethoxyethyl methacrylate,

Ethoxymethyl methacrylate and ethoxylated (meth) acrylates which preferably have 1 to 20, in particular 2 to 8, ethoxy groups;

Aminoalkyl (meth) acrylates and aminoalkyl (meth) acrylatamides, such as N- (3-dimethylaminopropyl) methacrylamide,

Dimethylaminopropyl methacrylate, 3-diethylaminopentyl methacrylate, 3-dibutylaminohexadecyl (meth) acrylate;

Nitriles of (meth) acrylic acid and other nitrogen-containing methacrylates, such as N- (methacryloyloxyethyl) diisobutylketimine, N- (methacryloyloxyethyl) dihexadecylketimine,

Methacryloylamidoacetonitrile, 2-

Methacryloyloxyethylmethylcyanamide, cyanomethylmethacrylate; heterocyclic (meth) acrylates, such as

2- (1-imidazolyl) ethyl (meth) acrylate,

2- (4-morpholinyl) ethyl (meth) acrylate and

1- (2-methacryloyloxyethyl) -2-pyrrolidone; Oxiranyl methacrylates, such as 2, 3-epoxybutyl methacrylate, 3,4-epoxybutyl methacrylate, 10, 11-epoxyundecyl methacrylate, 2,3-epoxycyclohexyl methacrylate, 10, 11-epoxyhexadecyl methacrylate;

These monomers can be used singly or as a mixture.

Particularly suitable monoethylenically unsaturated monomers are alkyl acrylates, preferably having 4 to 8

Carbon atoms in the alkyl radical, in particular butyl acrylate, vinyl esters, in particular vinyl acetate, vinyl propionate

and / or vinyl stearate, as well as styrene compounds,

in particular styrene and ring-substituted styrenes. Very particularly preferred systems contain, based on the total weight of the monoethylenically unsaturated

Compounds, at least 50.0 wt .-%, suitably at least 75.0 wt .-%, particularly preferably at least 90.0 wt .-%, in particular at least 95.0 wt .-%, styrene and at most 50.0 wt. %, advantageously not more than 25.0% by weight, more preferably not more than 10.0% by weight,

in particular at most 5.0 wt .-% ci to Cio-alkyl acrylate, in particular C ₄ - to Cs-alkyl acrylate.

Also subject to the polyunsaturated monomers

basically no further restrictions and include u. a. (Meth) acrylates derived from unsaturated alcohols, such as 2-propynyl (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, oleyl (meth) acrylate;

Glycol dimethacrylates such as 1,2-ethanediol di (meth) acrylate, 1,3-propanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate;

Dienes such as divinylbenzene, divinylpyridine, divinyltoluenes, divinylnaphthalenes, 1,3-divinylxylene, divinylethylbenzene, divinylsulfone, polyvinyl or polyallyl ethers of glycol, of glycerol, of pentaerythritol, of mono- or dithio derivatives of glycols and of resorcinol, divinyl ketone,

Divinyl sulfide, allyl acrylate, diallyl maleate, diallyl fumarate, diallyl succinate, diallyl carbonate, diallyl malonate,

Diallyl oxalate, diallyl adipate, diallyl sebacate,

Divinyl sebacate, diallyl tartrate, diallyl silicate,

Triallyltricarballylat, allyl methacrylate, triallyl citrate, triallyl phosphate, N, '-Methylendiacrylamid, Ν, Ν'-ethylenediacrylamide, 1, 2-di (-methylen-sulfonamido) ethylene, trivinylbenzene, trivinylnaphthalene, divinyl ether of

aforesaid glycols, diallyl phthalate,

Triallyl cyanurate and polyvinylanthracenes.

Preference is given to using polyunsaturated (meth) acrylates of the formula (I)

wherein R is hydrogen or methyl, preferably methyl, and R ^{1 is} a linear or branched alkyl radical having 2 to 20 carbon atoms, preferably 2 to 10

Carbon atoms, in particular with 2 to 4

Carbon atoms, means. Very particular preference is given to using ethylene glycol dimethacrylate.

In a particularly preferred embodiment of the present invention, at least two different polyunsaturated compounds are used, more preferably at least one polyunsaturated one

(Meth) acrylate compound, preferably unsaturated

(Meth) acrylates of the formula (I), in particular

Ethylene glycol dimethacrylate and at least one

Non (meth) acrylate compound, in particular divinylbenzene used. The proportion of each polyunsaturated

Compound is preferably at least 10.0% by weight, preferably at least 25.0% by weight, particularly preferably at least 30.0% by weight, advantageously at least 35.0% by weight, advantageously at least 40.0% by weight, very particularly preferably at least 45.0% by weight. -%, In particular 50.0 wt .-%, each based on the total weight of all multiply

unsaturated monomers.

Very particularly suitable crosslinked polymer particles for the purposes of the present invention are obtainable by free-radical polymerization of a monomer mixture which, based on its total weight,

a. 50.00% by weight to 99.99% by weight of styrene,

b. 0.00 wt .-% to 49.99 wt .-% of at least one Ci-Cio alkyl (meth) acrylate and

c. 0.01 wt .-% - 10 wt .-%, preferably 0.01 wt .-% to 3.00 wt .-% of at least one polyunsaturated compound, preferably at least one polyunsaturated

(Meth) acrylate.

The matrix polymer is also free radical

Polymerization of at least one monoethylenic

unsaturated monomers, in particular at least one monoethylenically unsaturated (meth) acrylate, obtainable. Basically, in this case, the same monoethylenically unsaturated monomers as for the crosslinked

Polymer particles are used.

Note, however, the limitations that arise due to the present invention and significantly limit the number of possible monoethylenically unsaturated compounds.

First, the crosslinked polymer particles in the

Matrix polymer be insoluble or incompatible. "Insoluble" in this context means that the polymers in the present concentration ratio are immiscible. The Gibbs mixing energy (AG _m i _X ) ^m is for the

Mixing process positive, since the weak negative

Entropieterm -T (AS _m i _X ) ^m can not compensate for the positive enthalpy term (AH _m i _X ) ^m . It is preferred in this

Related to the behavior at 25 ° C turned off. For more details on this phenomenon is on the standard literature, in particular on Hans-Georg Elias

"Macromolecules", Volume 1, 5th edition, 1990, Chapter 17, especially page 680-681, and, floor plan of

Macromolecular Chemistry ', Bruno Vollmert, E. Vollmert

Verlag, Karlsruhe, 1988, Volume IV, especially page 222-224.

Furthermore, the difference of the refractive index of the

crosslinked polymer particles minus the refractive index of the matrix polymer in the amount of at least 0.01, preferably at least 0.02, more preferably at least 0.04, in particular at least 0.08.

The values for the refractive index are determined according to ISO 489 at λ = 589.3 nm. Incidentally, the data refer to 20 ° C. This also applies to everyone else

Measured variables, to which reference is made, unless another reference temperature is explicitly specified.

The refractive index of most polymers is known from the literature and tabulated in common reference works, so that this value can be estimated in advance. Further information on this parameter can be found in the specialist literature, in particular J. Brandrup. E. H. Immergut "Polymer Handbook", 3rd Edition, 1989, Chapter VI "Refractive Indices of

Polymers ", are removed. In principle, all known thermoplastically processable polymers are suitable as the matrix polymer. These include, but are not limited to, polyalkyl (meth) acrylates such as polymethyl methacrylate (PMMA), polyacrylonitriles, polystyrenes, polyethers, polyesters, polycarbonates, polyvinyl chlorides.

Here, polyalkyl (meth) acrylates are preferred. These

Polymers can be used individually or as a mixture. Furthermore, these polymers may also be in the form of copolymers.

In the context of the present invention, homo- and

Copolymers of Ci-Ci8 ^_ alkyl (meth) acrylates, expediently of Ci-Cio-alkyl (meth) acrylates, in particular C1-C4-alkyl (meth) acrylate polymers, which may optionally still contain different monomer units, particularly preferably.

The notation (meth) acrylate here means both

Methacrylate, such as. As methyl methacrylate, ethyl methacrylate, etc., as well as acrylate, such as. For example, methyl acrylate,

Ethyl acrylate, etc., as well as mixtures of both monomers.

The use of copolymers which contain 70.0% by weight to 99.0% by weight, in particular 70.0% by weight to 90.0% by weight, of C 1 -C 10 -alkyl (meth) acrylates, has proven very special. Preferred C 1 -C 10 -alkyl methacrylates include

Methyl methacrylate (MMA), ethyl methacrylate,

Propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert. Butyl methacrylate,

Pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, octyl methacrylate, isooctyl methacrylate and

Ethylhexylmethacrylat, nonyl methacrylate, decyl methacrylate and Cycloalkylmethacrylate, such as

Cyclohexyl methacrylate, isobornyl methacrylate or

Ethylcyclohexyl methacrylate. Preferred C 1 -C 10 -alkyl acrylates include methyl acrylate, ethyl acrylate, propyl acrylate, Isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, isooctyl acrylate, nonyl acrylate, decyl acrylate and ethylhexyl acrylate, and cycloalkyl acrylates such as

for example, cyclohexyl acrylate, isobornyl acrylate or ethylcyclohexyl acrylate.

Very particularly preferred copolymers comprise 80.0% to 99.0% by weight of MMA units and 1.0% to 20.0% by weight, preferably 1.0% to 5% , 0 wt .-%, Ci-Cio-alkyl acrylate units, especially methyl acrylate and / or ethyl acrylate units. The use of available from Evonik Röhm GmbH polymethylmethacrylate

PLEXIGLAS ^® 7N has proven particularly successful in this context.

The matrix polymer preferably has a weight average molecular weight in the range from 10,000 to 1,000,000 g / mol, preferably in the range from 15,000 to 500,000 g / mol,

in particular in the range of 20,000 to 200,000 g / mol. It is preferably determined by means of gel permeation chromatography (GPC).

The matrix polymer can be known per se

Be prepared polymerization, wherein

radical polymerization process, in particular

Substance, solution, suspension and

Emulsion polymerization are particularly preferred. Particularly suitable for this purpose initiators include in particular azo compounds, such as 2,2'-azobis (isobutyronitrile) or 2, 2 'azobis (2, 4 dimethylvaleronitrile), redox systems, such as the combination of tertiary amines with peroxides or

Sodium disulfite and persulfates of potassium, sodium or ammonium or preferably peroxides (see, for example, H. Rauch-Puntigam, Th. Völker, "Acrylic and

Methacrylic Compounds ", Springer, Heidelberg, 1967 or Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. 1, pp. 386ff, J. Wiley, New York, 1978)

suitable peroxide polymerization initiators

Dilauroyl peroxide, tert. Butyl peroctoate, tert-butyl perisononanoate, dicyclohexyl peroxydicarbonate,

Dibenzoyl peroxide or 2, 2-bis (tert-butylperoxy) butane. It is also possible to carry out the polymerization with a mixture of different polymerization initiators having a different half-life, for example dilauroyl peroxide and 2,2-bis- (tert-butylperoxy) -butane, in order to control the free radical flow in the course of the polymerization and at different temperatures

Keep polymerization temperatures constant. The

amounts of polymerization initiator used are generally from 0.01 wt .-% to 2.0 wt .-% based on the monomer mixture.

The polymerization can be carried out both continuously and batchwise. After polymerization, the polymer is over conventional insulation and

Separation steps, such. As filtration, coagulation and

Spray drying, recovered and usually in

used particulate form.

The adjustment of the chain lengths of the polymer or

Copolymerizats can be carried out by polymerization of the monomer or monomer mixture in the presence of molecular weight regulators, in particular from those known

Mercaptans such as n-butyl mercaptan, n-dodecyl mercaptan, 2-mercaptoethanol or 2-ethylhexyl thioglycolate, pentaerythritol tetrathioglycolate;

wherein the molecular weight regulators generally in amounts of 0.05 wt .-% to 5.0 wt .-%, based on the monomer or monomer mixture, preferably in amounts of 0.1 wt .-% to 2.0 % By weight and more preferably in amounts of from 0.2% by weight to 1.0% by weight, based on the monomer or monomer mixture (cf., for example, H. Rauch-Puntigam, Th. Völker, " Acrylic and Methacrylic Compounds ", Springer, Heidelberg, 1967; Houben-Weyl, Methods of Organic Chemistry, Vol. XIV / 1, page 66, Georg Thieme, Heidelberg, 1961 or Kirk-Othmer, Encyclopedia of Chemical Technology, Vol. Pages 296ff, J. Wiley, New York, 1978). Preference is given to using n-dodecylmercaptan as molecular weight regulator. Furthermore, the use of

Pentaerythritol tetrathioglycolate particularly favorable. It may also be a combination of two or more regulators, in particular mixtures of n-dodecylmercaptan and

Pentaerythritol tetrathioglycolate, used in an advantageous manner.

The matrix polymer preferably has one

Light transmittance T _D 65 according to DIN 5033/7 in the range of 40% to 93%, preferably greater than 75%, in particular greater than 85%.

The crosslinked polymer particles are in the

Polymer particles according to the invention preferably spherical. "Spherical" in this context means that the ratio of the diameter of the crosslinked polymer particles in the direction of the shortest extension divided by the

Diameter of the crosslinked polymer particles in the direction of the longest extent greater than 80%, preferably greater than 90%, more preferably greater than 95%, in particular greater than 99%.

The mean particle size of the crosslinked polymer particles is in the range from 0.9 μm to 6.0 μm, preferably in the range from 1.5 μm to 5.0 μm, expediently in the range from 2.0 μm to 4.0 μm, in particular in Range from 2.2 ym to 3.0 ym. The mean particle size of the coated polymer particles is in the range from 50 μm to 300 μm, preferably in the range from 100 μm to 250 μm, expediently in the range from 125 μm to 225 μm, in particular in the range from 150 μm to 200 μm.

The stated average particle sizes are preferably based on the corresponding weight average.

All polymer particles preferably have a particle size in the range from 25 μm to 400 μm, preferably in the range from 30 μm to 350 μm, expediently in the range from 35 μm to 325 μm, in particular in the range from 39 μm to 320 μm.

All crosslinked polymer particles preferably have a particle size in the range from 0.5 .mu.m to 8.0 .mu.m, preferably in the range from 0.6 .mu.m to 7.5 .mu.m, expediently in the range from 0.7 .mu.m to 7.0 .mu.m, in particular Range from 0.75 ym to 6.5 ym.

The determination of the particle sizes of the coated polymer particles of the invention and the crosslinked

Polymer particles can be done in a known per se, such as. B. by light scattering methods or by microscopy suitably colored samples. For the determination of

Particle size of the coated invention

However, polymer particles have scattering studies on the preferably in a solvent such. As water, dispersed polymer samples particularly proven, in particular measurements by means of Mastersizer. The particle size of the

crosslinked polymer particles is preferably by means of

Electron microscopy determined. If the crosslinked polymer particles and / or the endopolymer particles have no spherical shape, the corresponding values are based on the maximum

Diameter of each particle determined.

The content of the matrix polymer based on the total weight of the coated polymer particles of the present invention is desirably 1.0 wt% to 50.0 wt%, preferably 5.0 wt% to 30.0 wt%, desirably 10.0 wt .-% to 25.0 wt .-%, in particular 15.0 wt .-% to 20.0 wt .-%.

The content of the crosslinked polymer particles, based on the total weight of the coated invention

Polymer particles is suitably 50.0% by weight to 99.0% by weight, preferably 70.0% by weight to 95.0% by weight,

Suitably 75.0 wt .-% to 90.0 wt .-%, in particular 80.0 wt .-% to 85.0 wt .-%.

In the context of a particularly preferred variant of

present invention, the matrix polymer is partially connected to the crosslinked polymer particles. This can

be achieved for example by appropriate grafting reactions. Particularly preferred are 0.001 wt .-% to 10.0 wt .-% of the matrix polymer with the crosslinked

Covalently bonded polymer particles.

The coated polymer particles according to the invention can be prepared in a manner known per se. The preferred method comprises a final polymerization technique wherein the monomers which ultimately form the crosslinked polymer particles are in the presence of a soluble preformed polymer

Matrix polymer dissolved in the above monomers and selected so that phase separation occurs early in the polymerization process,

be polymerized. When the phase separation takes place, the soluble preformed matrix polymer becomes the

continuous phase and the polymerized monomers form the crosslinked polymer particles as a discontinuous phase which are dispersed as discrete spherical particles in the soluble preformed polymer phase. The

crosslinked polymer particles are in the so-called

"soluble" matrix polymer is preferably insoluble and the latter becomes a carrier polymer in this technique, i. the original preformed matrix polymer used in the

Monomer system is dissolved, remains intact and after the polymerization of the monomer system, which merges into the crosslinked polymer particles, the continuous phase, which contains dispersed therein the crosslinked polymer particles.

Preferably, the endopolymerization takes place as

Suspension polymerization process (bead polymerizations). In this process, the monomer / matrix polymer solution is treated as a disperse phase by the action of mechanical forces (stirring) in a non-solvent (continuous

Phase) and polymerized in this form. The polymer formed is predominantly soluble in the monomer. Under the influence of the interfacial tension the monomer forms spherical drops, which are successively polymerized, whereby in the individual drops the

Matrix polymer and the monomers increasingly segregate and, as a result, the matrix polymer to the crosslinked

Polymer particles sets, this quasi encased.

In order to obtain the droplet shape during the polymerization and to prevent the collapse of droplets, it is expedient to add to the polymerization batch so-called "dispersants" or distributors (protective colloids),

Preferably, substances that have ended up

Separate polymerization completely from the peribular polymer. The "distributor" causes the monomer droplets once formed are stabilized to the extent that a combination of drops practically

stays undone.

As a continuous phase is usually used water. As monomers suitable for the polymerization, therefore, primarily poorly soluble to water-insoluble, free-radically polymerizable monomers come into question. (See Houben-Weyl, 4th edition, Vol. XIV / 1 "Macromolecular substances", p. 406-433, G. Thieme-Verlag 1961.)

The distributors used are preferably (water-insoluble) salts of inorganic acids, such as barium sulfate or barium carbonate, or high molecular weight natural products or synthetic polymers. The group of high molecular weight distributors includes water-soluble colloids, such as polyvinyl alcohol, partially saponified polyvinyl acetate, methyl cellulose, starch,

Gelatin, pectin, the alkali metal salts of polyacrylic acid or the alkali metal salts of styrene or vinyl acetate maleic anhydride copolymers and the like. a. (See Houben-Weyl, loc.cit p. 411-430.) The ratio of aqueous to

Monomeric phase is preferably 2: 1 to 4: 1.

In bead polymerization it is known to use initiators which are, to a first approximation, soluble in the monomer but insoluble in water. In most cases, the amount of starter used is from 0.1% by weight to 1.0% by weight, preferably by 0.5% by weight, based on the monomers. As starters are preferably the usual monomer-soluble organic peroxides or corresponding azo compounds used, such as. B. dibenzoyl peroxide, lauroyl peroxide,

Azoisobutyronitrile. Free radical generator with higher

Decay temperatures can additionally be used if towards the end of the reaction as complete as possible Polymerization the temperature is increased. The bead size can be adjusted in the stressed frame.

Further, the lubricants commonly used, such as fatty alcohols, stearic acid esters, palmitic acid esters or natural waxes may be added, preferably before polymerization.

The practice of the polymerization may be such that the water, the monomers, the matrix polymer, the initiator, optionally the dispersant and

optionally, the lubricant is placed together and then heated, for example to about 90 ° C. Optionally, the excess heat of polymerization, especially from 95 ° C, dissipated by external cooling. Temperatures above 115 ° C should be avoided if possible. The duration of the polymerization is usually in the range of 1 to 5 hours. The viscosity of the polymerization batch

(Measured with a Brookfield viscometer at the

Polymerization temperature) is generally in the range between 800 mPas and 8,000 mPas.

The partially reactive lubricants are preferably added only from about 20% conversion. The addition of regulators can also take place during the polymerization.

After the end of the reaction, the beads are generally separated by filtration or centrifugation. adherent

Additives can be suitably, e.g. B. be removed by washing with dilute acid and water. The beads are often heated, preferably with

Air circulation, dried, z. B. in cupboards.

For the purposes of the present invention, a procedure has proven particularly useful in which one i. the matrix polymer in the monomer mixture for the

dissolve crosslinked polymer particles,

ii. the monomer-polymer solution over a particular

Driven period into an aqueous template containing the distributor, and

iii. the suspension using at least one

Initiator polymerized, which is soluble in the monomer mixture.

The weight ratio of matrix polymer to monomer mixture is preferably in the range from 1: 1.28 to 1: 5.6. Furthermore, the weight ratio of water to solution is preferably in the range from 1: 2 to 1: 4, preferably in

Range of 1: 2.2 to 1: 3, in particular in the range of 1: 2.4 to 1: 2.65, selected. The distributor used is conveniently a polyvinyl alcohol, particularly preferably a partially hydrolyzed polyvinyl acetate, preferably having a degree of hydrolysis greater than 50 mol%.

The polymer particles of the invention are characterized by a high thermal stability. They preferably have a temperature resistance of at least 200 ° C, in particular of at least 250 ° C, without thereby causing a

Restriction is to take place. Here, the term "temperature resistance" means that the particles are essentially not subject to any thermal degradation

Temperature stability can be determined by thermogravimetric

Determination determined. The determination method is familiar to the person skilled in the art. When the method is used, a mass loss of not more than 2.0% by weight of the plastic sample to be measured occurs up to the indicated temperature under protective gas.

Another advantage of the polymer particles according to the invention is that to achieve the inventive Advantages of a subsequent secondary networking not

is required. Secondary crosslinking in this context means a subsequent crosslinking via groups which do not react during the initial polymerization, but which can later be brought to reaction by suitable measures, in particular by increasing the temperature.

The use of a secondary crosslinker is known in the art, for. B. in DE 2146628 described as necessary to the deformation of the particles during shearing z. B. to counteract in the injection molding.

In the context of the present invention, however, such a secondary crosslinking is not required since the polymer particles according to the invention are already advantageous

Characterize property spectrum. On the contrary, the

polymer particles according to the invention preferably have less than 1.0% by weight, based on their total weight,

more preferably less than 0.5 wt .-%, most preferably less than 0.1 wt .-%, in particular no, polar groups, which can be subsequently crosslinked, in particular by increasing the temperature. These include in particular hydroxy groups, primary or secondary

Amino groups, amide groups, isocyanate groups, alkyl groups having a cyanide group on a primary or secondary carbon atom, carboxyl groups and epoxide groups.

Possible fields of application of the invention

Polymer particles include, in particular, the matting of thermoplastic polymers. Corresponding molding compositions can be obtained by introducing the invention

Polymer particles in a thermoplastic polymer, eg. B.

by mixing the components, wherein the Components are preferably distributed homogeneously in the molding composition.

The polymer particles according to the invention are in principle suitable for all known thermoplastic

processable polymers. These include, among others

Polyalkyl (meth) acrylates, such as

Polymethyl methacrylate (PMMA), polyacrylonitriles, polystyrenes, polyethers, polyesters, polycarbonates, polyvinyl chlorides.

Here, polyalkyl (meth) acrylates are preferred. These

In the context of the present invention, homo- and

Methyl methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate,

Isobutyl methacrylate, tert. Butyl methacrylate,

Cyclohexyl methacrylate, isobornyl methacrylate or

Ethylcyclohexyl methacrylate. Preferred C 1 -C 10 -alkyl acrylates include methyl acrylate, ethyl acrylate, propyl acrylate,

Isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert. Butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, isooctyl acrylate, nonyl acrylate, decyl acrylate and ethylhexyl acrylate, and cycloalkyl acrylates such as

PLEXIGLAS ^® 7N has proven particularly successful in this context.

The weight-average molecular weight of the polymer to be matted is preferably in the range of 10,000 to

1,000,000 g / mol, preferably in the range of 15,000 to 500,000 g / mol, in particular in the range of 20,000 to 200,000 g / mol. It is preferably determined by means of gel permeation chromatography (GPC).

The thermoplastic polymer may contain other additives well known to those skilled in the art. To be favoured

impact modifiers, external lubricants, antioxidants, flame retardants, UV stabilizers,

Flow aids, metal additives for shielding

electromagnetic radiation, antistatic agents,

Mold release agents, dyes, pigments, adhesion promoters, weathering agents, plasticizers, fillers and the like. Furthermore, the addition of inorganic nanoparticles is particularly advantageous. The preparation of impact modifiers is preferably carried out by

Emulsion polymerization process. In this way, a stable latex having an arithmetic weight average particle size in the range of 0.05 ym to 5 ym is obtained, which is usually spray dried or

coagulated / dry-washed to the polymer

isolate.

Especially for the purposes of the present invention

suitable emulsifiers are known in the art and include in particular conventional soaps, alkylbenzenesulfonates, such as

sodium dodecyl,

Alkylphenoxy polyethylenesulfonates, sodium lauryl sulfates, long chain amine salts, long chain carboxylic and sulfonic acid salts, etc. Particularly preferred emulsifiers include hydrocarbon groups having 8 to 22 carbon atoms attached to highly polar solubilizing groups such as alkali metal and ammonium carboxylate groups.

Sulfate half ester groups, sulfonate groups,

Phosphate partial ester groups etc ..

The incorporation of the impact-modifying substances can be carried out by subsequent mixing. However, it has proven particularly effective, the impact-modifying

Substances already before or during the production of the

add thermoplastic polymer such. B. by

Dispersing the impact modifiers in a monomer mixture used to prepare the impact modifier

thermoplastic polymer is used, or in a monomer / polymer syrup mixture, which together the

desired thermoplastic polymer results. Similarly, the impact modifiers in a

Casting mixture in the form of an emulsion, suspension or

Dispersion in water or in an organic carrier are given. The water or organic carrier can then be removed before or after casting into the final polymer form. The impact modifiers may also be compounded with the polymer by extrusion molding. For further details regarding the

Addition of impact modifiers

thermoplastic polymers, reference is made to U.S. Patent 3,793,402.

A particularly preferred toughened

thermoplastic polymer is polymethylmethacrylate, which is commercially available from Evonik Röhm GmbH under the

Trade names Plexiglas ^® zk6BR is available.

The thermoplastic polymer preferably has one

The difference of the refractive index of the networked

Polymer particles minus the refractive index of the

amount of thermoplastic polymer is preferably at least 0.01, advantageously at least 0.02,

particularly preferably at least 0.04, in particular at least 0.08.

The content of the thermoplastic polymer, based on the total weight of the molding composition, is favorably 20.0 wt .-% to 99.9 wt .-%, preferably 50.0 wt .-% to 99.8 wt .-%, particularly preferably 75.0 wt .-% to 99.5 wt .-%, most preferably 80.0 wt .-% to 95.8 wt .-%, more preferably 90.0 wt .-% to 99.5 wt. % and most preferably 95.0% to 99.0% by weight. The content of the polymer particles according to the invention, based on the total weight of the molding composition, is advantageously 0.1% by weight to 80% by weight, preferably 0.1% by weight to 50.0% by weight, particularly preferably 0, 2 wt .-% to 50 wt .-%, most preferably 0.5 wt .-% to 25 wt .-%, especially preferably 0.2 wt .-% to 20.0 wt .-%, very specifically

preferably from 0.5% to 10.0% by weight, and most preferably from 1.0% to 5.0% by weight.

The molding composition of the invention may be as conventional

Thermoplastics for various end products

further processed, in particular transformed.

Preferred forming processes include profile extrusion, sheet and film extrusion, injection molding and

Molding. That from the plates, foils or

Profile extrusion resulting product has a

textured surface and a matte appearance without special patterned rollers, rollers, polishing or

To require grinding devices. The product, which is obtained by injection molding, has a matte

Appearance .

The term "textured surface" as used here

is used, describes a surface with the following roughness:

The average roughness Ra is preferably at least 0.05 μm, preferably at least 0.15 μm, particularly preferably at least 0.25 μm, in particular at least 0.30 μm.

o The average roughness Rz is preferably

at least 0.30 ym, preferably at least 0.50 ym,

particularly preferably at least 1.50 μm, in particular at least 2.50 μm.

The roughness Rt is preferably at least 0.50 μm, preferably at least 1.00 μm, particularly preferably

at least 3.00 ym, especially at least 5.00 ym. The surface roughness is determined according to DIN EN ISO 4287 and DIN EN ISO 4288.

One of the advantages of the present invention is that the total white light transmission (Total White Light

Transmission (TWLT)) is much greater than similar commercial products provided with inorganic fillers such as barium sulfate or color concentrate to achieve a matte appearance. The TWLT value is measured according to ASTM: E1331 and E1164, preferably using a Hunterlab Colorimeter D25 model.

The advantage of the polymer particles according to the invention lies in the high forward scattering of the moldings according to the

Incorporation of the particles into the molding compositions. As a result, in comparison with conventional opacifiers, z. B. BaS0 ₄ or Ti0 ₂ , achieved significantly higher light output, since the loss of

Backward scattering is low. This preferred

Forward scattering can be determined by measuring the transmission in combination with the energy half-angle of moldings containing the particles.

The matted appearance can be determined by means of an opacity or opacity measurement (turbidity measurement). The higher the opacity value, the better the opacity or unrecognizability. To one

To achieve a matt appearance, the opacity should be at least 10%. The loading of the polymer particles and the difference in refractive indices affects the opacity of the sample, which is determined by the opacity number

is expressed. The determination of the opacity values is preferably carried out according to the standards ASTM D2805-80, ASTM D589-65, TAPPI T-425 and TAPPI T-519. The molding composition according to the invention and the moldings obtainable therefrom preferably have a light transmittance T _D65 according to DIN 5033/7 in the range of 40.0% to 93.0%, preferably of at least 50.0%, particularly preferably

at least 55.0%, suitably at least 70.0%, in particular in the range from 80.0% to less than 90.0%.

Moldings obtainable from the molding compositions according to the invention preferably have an intensity half-value angle (IHW), measured in accordance with DIN 5036 with a LMT goniometer measuring station GO-T-1500 from the company LMT, in the range from 1 ° to 55 °, preferably greater than 2.0 ° , in particular greater than 4.0 °, on. IHW values in the range of greater than 10 ° and less than 50 ° are particularly expedient. Especially useful are values in the range of greater than 15 ° and less than 45 °, even more preferred are values for the IHW in the range of greater than 20 ° and less than 40 °.

The tensile strength (ISO 527) of the molding compound

Moldings available are preferably at least 20 MPa, preferably at least 40 MPa, more preferably at least 50 MPa, in particular at least 60 MPa.

The modulus of elasticity of moldings available according to ISO 527 is when impact resistant

Polymer matrices favorably greater than 1600 MPa, preferably greater than 1700 MPa.

The Charpy impact strength of the molding compound

Moldings according to ISO 179 available when using impact-resistant polymer matrices is preferably at least 30 kJ / m ² , preferably at least 40 kJ / m ² , in particular at least 50 kJ / m ² . The elongation at break of available from the molding composition

Shaped articles according to ISO 527 are advantageously greater than 3%, preferably greater than 4%.

The breaking elongation of available from the molding composition

Shaped bodies according to ISO 527 is preferably at least 2%, preferably at least 15%, in particular at least 30%.

The Vicat softening temperature VET (ISO 306-B50) of the molding composition according to the invention and the moldings obtainable therefrom is not impact-resistant when used

Polymer matrices preferably at least 95 ° C, preferably at least 97 ° C, more preferably at least 103 ° C, especially greater than 104 ° C.

The melt index MVR (ISO 1133, 230 ° C / 3.8 kg) of

molding composition of the invention and the shaped body obtainable therefrom is the use of impact-resistant polymer matrices preferably at least 1.0 cm ^3/10 min, preferably at least 1.3 cm ^3/10 min, more preferably at least 3.0 cm ^3/10 min, in particular at least 4 , 5 cm ^3/10 min.

The moldings obtainable according to the invention can

especially for lighting, signs or symbols,

Sales outlets and cosmetic vendors, containers, home and office decorations, furniture applications, shower doors and office doors can be used.

The invention is further explained by the following examples and comparative examples, without this being intended to limit the scope of the invention.

The specified measured variables were determined as follows.

Optical properties For further investigation, a standard polymethyl methacrylate molding composition (PLEXIGLAS® 7N, available from Röhm GmbH) was modified with the respective amount of end copolymer. From these molding materials test specimens were produced by injection molding with the dimensions 60 mm x 45 mm x 3 mm, where the

Transmission (T) according to DIN 5036 and the yellowness index (G) according to DIN 6167 with a measuring device Lambda 19 from Perkin Eimer. Furthermore, the scattering power was determined by measuring the intensity half-value angle (IHW) in accordance with DIN 5036 using a LMT goniometer measuring system GO-T-1500 from LMT.

Determination of particle size

The values given for the particle size relate in each case to the volume average particle size distribution. This particle size distribution can be determined, for example, by a Mastersizer 2000 from Malvern Instruments Ltd. The exact measuring method for determining the particle size is included in the user manual. The standard ISO 13320-1 applies, the calculation is based on the Fraunhof model and Mie theory. The parameters used are the refractive index n _D of 1.489 (polymethymethacrylate) and the absorption coefficient of 0. This method is particular to the purposes of the present invention

prefers .

Furthermore, particle sizes were partially analyzed by microscope:

Microscope type Olympus BH-2, magnification IC2, camera type Olympus Camedia C-4000 with microscope attachment: C3040-ADL and U-PMTVC.

In addition, particle size can be measured by measuring and

Counting the particles on appropriate Scanning electron micrographs are determined. Here the measuring device JEOL JSM 840A was used.

REM: JEOL-JSM 840A

Electron generation: Laß6 cathode

Acceleration Voltage: 5 kV

Image Capture Software: SEM Control (POINT Company) - Ver. 5.6.5.0

Evaluation with software: ICW32 (company Börder) - Ver.

2.0.0.96

Thermostability:

Thermogravimetry measurements were taken on a

Analyzer named AutoTGA 2950 V5.4A

(Software "Universal V3.9 TA instrument") at a heating rate of 505K / min from room temperature to 500 ° C.

A. matting agent

In an IL Schmizoreaktor Plexiglas 7N was dissolved in styrene at 50 ° C within 2h. The mixture was allowed to stand at room temperature overnight. Subsequently, the crosslinker glycol dimethacrylate and the initiators dilauryl peroxide and dibenzoyl peroxide (75% strength) were added at 250 rpm. Meanwhile, in a second Schmizoreaktor the water with the distributor (Mowiol 40-88, 5%, 35.4g, 16.2% ba monomers) and the excipients butyl phosphate (0.27g) and sodium sulfate (1.47 g) weighed and the mixture dissolved. While stirring (blade stirrer), the aqueous phase (at 250 rev / min) was heated to about 50 ° C (bath temperature

55 ° C). After reaching the temperature was the

Monomer / polymer solution within 35 minutes of

aqueous phase is added dropwise. The reaction mixture was stirred at 50 ° C. for 60 minutes (bath temperature 55 ° C.) and then the bath temperature was adjusted to 85 ° C. It was stirred for 4.5 h at this temperature. Subsequently, the

Reactor content cooled to about 45 ° C and over a 250 ym Filtered sieve. The peribular polymers were transferred to a filter chute and washed with 5 L of distilled water. The drying took place over 20 h at 50 ° C in

Convection oven. The dried product was sieved through a 2 mm sieve.

There were different approaches under variation of the

Ratio of Plexiglas 7N to monomers carried out (see Table la). The order of magnitude of the

Polymer particle was visually estimated and partially the volume average particle size distribution (Malvern

Mastersizer). Furthermore, the

Magnitude of the by suspension in acetone

liberated by means of a microscope (see Table lb).

Examples Bl to B4

Monomers: styrene / glycol dimethacrylate [wt. Parts] / [wt. - Parts]: 99/1

Phase ratio: water / monomers = 3/1

Dilauryl peroxide / dibenzoyl peroxide [g] / [g]: 2.84 / 1.89

Water quantity [g]: 668.7

Stirring speed [rpm]: 250

Example B5

The polymerization was carried out analogously to Example B2 with the

following deviations carried out:

Dropwise addition of the monomer-polymer solution at 81 ° C

internal temperature

Initiator: dilauryl peroxide / tert. Butylper-2-ethylhexanoate [g] / [g]: 3.17 / 1.09

Visual magnitude [mm]: 0.3-2

Behavior in acetone: Crosslinked particles Example B6

The polymerization was carried out analogously to Example Bl, except that instead of 1 wt .-% glycol dimethacrylate per 1 wt .-% divinylbenzene and 1 wt .-% glycol dimethacrylate was used.

Example B7:

The procedure was carried out analogously to Example Bl, but there were 2% by weight Glykoldimethacrylat used.

Round styrene domains are provided in a 7N matrix by endopolymerization.

Table la: Overview of the completed endopolymerizations

GA: glycol dimethacrylate; DVB: divinylbenzene

Table lb

By means of REM the following average values were calculated on

selected polymer particles B7 or on the molding material C2 (containing B7, see Table 5):

Table 1c: Evaluation of the orders of magnitude of the endopolymer carrier beads, of the finely divided end-polymers in the carrier beads and of the scattering agent in the molding compound C2 on the injection-molded die; Determining the sizes by means of SEM on exemplary beads or areas of the injection-molded sheet.

B7 B7 Injection molding made of C2

Size Endopolymer size Finely sized size Dispersant Carrier beads Final polymer in the molding compound [ym] [ym] Carrier beads

(Recording on

Fracture edge) [ym]

202 2, 98 4.04

316 6, 30 3.40

189 3, 81 2.40

101 3.78 4, 35

73 0.87 2.00

57 1.10 4.00

208 1,29

306 1.06

211 2,15

40

235

72

269

Average 175 average 2.6 average 3.4 min. 40, max.316 min. 0.87, max. 6.30 min. 2.00, max.

4, 35 Comparative request

For comparison, approaches by diffusing styrene into the granules and the use of an aqueous, alkaline solution of a

Polymethacrylsäure copolymers listed as distributors (see Tables 2 and 3). a) Comparative Examples Diffusion of styrene into the

Polymer and subsequent polymerization (Table 2) In an IL Schmizoreaktor 400 mL of dist. Water submitted to 100 g Plexiglas 7N granules. The mixture was heated to 55 ° C internal temperature and a

Monomer solution containing 29.7 g of styrene, 0.30 g

Allyl methacrylate, 0.59g dilauroyl peroxide and 0.02g tert-butylper-2-ethylhexanoate at a stirring rate of 250U / min in 5 portions a about 6g within 5 hours. After complete addition of the monomer solution, the batch was stirred with the baked granules for a further 2 h at 55.degree. Subsequently, the reaction mixture was allowed to stand at room temperature overnight. After 17 hours, the batch was heated to 94 ° C outside temperature and stirred for 6 hours at this temperature. It was then cooled to room temperature and removed the baked granules present.

Crosslinker: allyl methacrylate (instead of glycol dimethacrylate), initiator: dilauryl peroxide and tert-butyl per-2-ethylhexanoate 0.59 g / 0.02 g

Stirring speed: 250 rpm Table 2

based on an aqueous, alkaline solution of a polymethacrylic acid copolymer and 1.24 g

Added sodium chloride. b) Comparative Examples Suspension polymerizations of monomer-polymer solutions using an aqueous, alkaline solution of a

Polymethacrylic acid copolymers as a distributor

Crosslinker: allyl methacrylate (instead of glycol dimethacrylate),

Initiator: dilauryl peroxide,

Distribution system: aqueous, alkaline solution of a polymethacrylic acid copolymer / sodium chloride 5.7 g / 0, 63 g Table 3

: Dropping the monomer-polymer solution into the aqueous phase

It has been found that using an aqueous, alkaline solution of a

Polymethacrylic acid copolymers as distributors are obtained only crosslinked beads (see Table 3) which swell in acetone but do not disintegrate. In contrast, suspension polymerization using a polyvinyl alcohol (Mowiol 40-88) as a distributor resulted

uncrosslinked beads (see Table 1). thermal stability

The thermostability of the polymers were determined by means of

thermogravimetric analysis (TGA). The

Results are summarized in Table 4. The following abbreviation is used:

T _c : temperature of the mass point at the midpoint

(Intersection of the TG curve with the parallels to the abscissa axis through the midpoint between A

(Starting point - intersection of the extrapolation line for the initial mass with the tangent to the TG curve in the maximum gradient) and B (end point - intersection of the extrapolation line for the

Final mass after reaction with the tangent to the TG curve in the maximum gradient); see DIN EN ISO

11358, 1997, section 9.3)

Thermogravimetry (TGA) registers the

Mass changes of a sample, which is subjected to a mostly linear heating (DIN EN ISO 11358,

Thermogravimetry of (TG) of polymers)). The course of the mass change is usually represented as a relative indication (in%) compared to the initial sample mass. Often the derivation of the TGA curve obtained in this way after the time because of better clarity appropriate. It expresses the rate of mass change in% / min. Table 4: Thermostability of the polymers

* Conditioning 16h 80 ° C

** Conditioning for 16 h at 80 ° C. TGA measurements were made from room temperature to 505 ° C with a heating rate of 5K / min under a nitrogen atmosphere.

*** mixed lot

This gives the statement that the invention

Endopolymerisat having beads a better

Thermostability as Acematt OP 278 and Example 1 (copolymer). Furthermore, it is clear that the temperature of the maximum degradation rate of the inventive examples of SBX-8 corresponds relatively.

B. molding compounds

The beads of Examples B2 and B4 were combined and compounded in two different concentrations with Plexiglas 7N (Al and A2). The beads of Examples B6 and B7 were also in two different

Concentrations are compounded with Plexiglas 7N (molding compositions Bl and B2, Cl and C2, Dl and D2). 1) The compounding was done on a 30 Stork extruder at a

Temperature T of 220 ° C, the production of 65x40x3mm

Tile on the Arburg 221 with closed cylinder. The results of the tests on 3 mm specimens contain the following Table 5. Table 5

* = Sample inhomogeneous with respect to IHW

The data for the end-polymer, additive quantity and content of litter are based on theoretical values. The assumption was made that complete polymerization took place and the total amount of catalyst used

Monomer and crosslinker polymerized and none

Residual monomer contents are present. The additives B2 and B4 were each prepared with only 1 wt .-% crosslinker. The additives B6, B7 and B8 with 2 wt .-% crosslinker or a combination of crosslinkers.

Advantageously, a larger amount of crosslinker to

use to stabilize the Endopolymerisat areas accordingly and better network.

Otherwise, inhomogeneities occur with respect to IHW, as in the case of the molding compositions A1 and A2, prepared with additives B2 and B4, which may be due to a decomposition of the incompletely crosslinked particles.

For comparison, compounds with Acematt OP 278 (sales product from Evonik Degussa, two-phase polymer) were listed in PLEXIGLAS 7N. The results of the tests on 3mm specimens are shown in Table 6 below

Roughness determination was carried out in accordance with DIN EN ISO 4287 and DIN EN ISO 4288.

Table 6

Compoundings on 30 Stork extruder T = 220 ° C, production of 65x40x3mm plates on the Arburg 221 with closed cylinder

Theroret. Content of scattering agent 1.0 or 0.50 wt .-%

As can be seen from the IHW values, Acematt OP 278 is not a suitable additive for light-scattering a Plexiglas molding compound. Additionally were on

extruded ribbon of the molding materials AI and A2 a higher average roughness Ra, a higher gem. Roughness Rz and a higher roughness Rt determined.

A comparison of the optical properties of molding compositions containing the particles according to the invention, Techpolymer SBX- 8 and Techpolymer SBX-4 (sales products of Sekisui, Japan, crosslinked polystyrenes, average particle size 8ym and 4ym, respectively) are reported in Table 7. The basic molding compound used was Plexiglas 7N. The compounding was carried out on a 30 Stork extruder at a temperature of T = 220 ° C. Subsequently, 3.05 mm thick extrusion plates were produced at a temperature of 210 ° C.

Table 7:

At low amounts of gritter reach the

molding compositions according to the invention higher transmissions Furthermore, with the same spreading agent content with SBX-4, the highest scattering effect is defined over the

Intensity half-value angle, observed. The

Scattering agent according to the invention achieves the same

Scattering content only slightly lower IHW.

Advantageously, compared to SBX-8 significantly less inventive scattering agent to use to

to get certain scattering effect. Compared to SBX-4, there are no advantages with regard to the scattering effect. However, it should be emphasized that the handling of the particles according to the invention in operation is much easier and safer.

weatherability

To investigate the weathering behavior of the

0.1% by weight or 0.25% by weight of an inventive end-product according to the invention

Endopolymerisats from Example B6 and for comparison of the Techpolymere SBX-4 and SBX-8 in Plexiglas 7N compounds compounded and exposed to Xenotest weathering for 2000h.

The compounding was carried out on a 30 Stork extruder at a temperature of T = 220 ° C. Subsequently were

Extruded plates of thickness 3.05 mm at a temperature of 210 ° C made. The weathering behavior was assessed by yellowness and transmission changes as well as visual assessment after 500h, 1000h and 2000h Xenotest. The device name is Xenotest 1200 (45 W / m ² ).

The results are summarized in Table 8. Additive content of relative

Scattering difference in 7N [wt. Yellow value after

%] 2000 h

weathering

compared

to t = 0

B6 0.1 0, 61

B6 0.25 2.77

SBX-4 0,1 2,31

SBX-4 0.25 3, 85

SBX-8 0.1 2.4

SBX-8 0.25 4.23

Table 8 shows that the relative increase in yellowness of the particles according to the invention is significantly lower for the same weight in each case than for the Sekisui SBX particles. Molding compositions comprising the inventive

Endopolymers thus have a significantly better weathering behavior.

Claims

Claims:

A polymer particle comprising crosslinked polymer particles encased in a matrix polymer, wherein i. ) the crosslinked polymer particles by radical

a. From 90.00% to 99.99% by weight of at least one monoethylenically unsaturated monomer and b. From 0.01% to 10.00% by weight of at least one polyunsaturated monomer, ii. ) the matrix polymer by radical

Polymerization of at least one monoethylenically unsaturated monomer is available,

iii. ) the crosslinked polymer particles are insoluble in the matrix polymer,

characterized in that

I.) the average particle size of the crosslinked

Polymer particles in the range of 0.9 ym to 6.0 ym,

II.) The mean particle size of the coated

Polymer particles in the range of 50 ym to 300 ym,

III. ) the difference of the refractive index of the crosslinked polymer particles and the refractive index of the

Matrix polymer, each measured at 20 ° C, at least 0.01.

2. Polymer particles according to claim 1, characterized in that all encased polymer particles have an average particle size in the range of 25 ym to 400 ym and / or that all crosslinked polymer particles have a having average particle size in the range of 0.5 ym to 8.0 ym.

3. Polymer particles according to at least one of the preceding claims, characterized in that the crosslinked polymer particles are obtainable by free-radical polymerization of a monomer mixture, based on their total weight,

a. 50.00% by weight to 99.99% by weight of styrene,

b. 0.00 wt .-% to 49.99 wt .-% of at least one C i -Cio alkyl (meth) acrylate and

c. 0.01 wt .-% to 10.00 wt .-% of at least one polyunsaturated (meth) acrylate and / or that the crosslinked polymer particles are obtainable by free-radical polymerization of a monomer mixture comprising at least two different polyunsaturated monomers.

4. Polymer particles according to at least one of the preceding claims, characterized in that the

Matrix polymer by radical polymerization

at least one monoethylenically unsaturated

(Meth) acrylate is available.

5. Polymer particles according to at least one of the preceding claims, characterized in that 0.001 wt .-% to 10.0 wt .-% of the matrix polymer with the crosslinked

Polymer particles are covalently bonded.

6. A process for the preparation of polymer particles according to at least one of the preceding claims, characterized in that one

i. dissolving the matrix polymer in a monomer mixture for the crosslinked polymer particles,

ii. dripping the monomer-polymer solution over a period of time in an aqueous template containing the distributor, and

iii. the suspension is polymerized using at least one initiator which is soluble in the monomer mixture.

7. The method according to claim 6, characterized in that the weight ratio of matrix polymer to

Monomer mixture in the range of 1: 1.28 to 1: 5.6 selects and / or that one chooses the weight ratio of water to solution in the range of 1: 2 to 1: 4.

8. The method according to claim 6 or 7, characterized

characterized in that in step ii. Polyvinyl alcohol added as a distributor.

9. molding composition containing, based on their total weight, i. 20.0 wt .-% to 99.9 wt .-% to be matted

Polymer and

ii. 0.1% by weight to 80.0% by weight of polymer particles according to at least one of claims 1 to 7.

10. Molding composition according to claim 9, characterized in that it contains inorganic nanoparticles.

11. Matted molded article obtainable by molding a molding composition containing at least one polymer to be matted and one or more polymer particles according to any one of claims 1 to 5.

12. Shaped body according to claim 11, obtainable by

Extrusion of the molding material.

13. Shaped body according to claim 11 or 12, characterized

marked that he

i. a transparency, measured according to DIN 5036, in

Range from 40.00% to 93.00%,

ii. an intensity half-value angle measured in accordance with DIN 5036, in the range of 1.0 ° to 55.0 °.

14. Shaped body according to at least one of claims 11 to 13 with an average roughness Rz to DIN 4768 of at least 0.3 ym.

15. Use of a shaped article according to any one of claims 11 to 14 as a component for lighting, signs and symbols, points of sale,

Cosmetic sales stands, containers, or home

Office decorations, furniture applications, shower doors and office doors.