DE19816148A1 - Polymerizable methacrylate-polysiloxane composition for use in dentistry etc. - Google Patents

Abstract

A polymerizable composition comprises (A) a polymerizable methacrylate; and (B) single molecule, crosslinked organopolysiloxane particles of average diameter, the particles being at least 5 wt.% soluble in toluene, THF or water and being such that at least 80% are of diameter differing by no more than 30% from the average diameter.- DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for (a) polymers contained in the above composition

Description

The invention relates to polymerizable compositions, which polymerizable (meth) acrylate and Include organopolysiloxane particles and that after polymerization of these masses of polymers obtained.

Compositions containing acrylate are made with organopolysiloxanes added to the physical properties of the polymers change.

For example, DE-A-39 13 252 pasty curable Methacrylate compositions described that agglomerated Contain organopolysiloxane particles as a filler. The Viscosity of the methacrylate masses increases especially at high ones Fill levels strongly and deteriorate their processability. If these methacrylate masses as dental masses, such as Filling materials are used, high degrees of filling are very desirable as this will cause shrinkage when the masses harden can be severely restricted.

Impact modifiers containing silicone are described in Acrylic materials used because these are in contrast to pure organic materials have better resistance to oxidation and cause low glass transition temperature.

Methacrylate-modified silicone rubber particles are used in an acrylate composition of EP-A-398 577 as an improver of the Impact strength. High degree of filling of silicone rubber particles also lead to agglomerates, which have the effect of Impact improvers limit and the viscosity of the Increase mass.

The agglomerates of organopolysiloxane particles also lead to cloudiness in the (meth) acrylate compositions.

The object was to contain organopolysiloxane particles to provide (meth) acrylate-containing compositions, in which the organopolysiloxane particles homogeneously distributed and not agglomerated.

The invention relates to polymerizable compositions which

• A) polymerizable (meth) acrylate and
• B) Organopolysiloxane particles made up of a single molecule exist, are networked, have an average diameter of 5 to 200 nm, which in a solvent that is selected from toluene, tetrahydrofuran and water 20 ° C are at least 5 wt .-% soluble and in which at least 80% of the particles have a diameter that deviate at most 30% from the mean diameter.

The organopolysiloxane particles (B) are polymerizable Acrylate distributed homogeneously, behaves like dissolved particles and therefore have almost no agglomerates.

The mechanical and optical properties of the Compositions can therefore be specifically adjusted.

When using organopolysiloxane particles (B), the one have an average diameter of at most 100 nm, can Contrary to the use of agglomerate-forming particles optically clear to transparent polymerizable compositions getting produced.

Compositions with high fill levels show little increase Viscosities compared to pure polymerizable acrylate (A) and are therefore easy to process. Such Compositions exhibit low volume shrinkage Polymerization.  

The polymers modified with organopolysiloxane particles also have lower water absorption, which is special when using the cured polymers as optical Storage materials such as B. compact discs, of importance is.

The organopolysiloxane particles (B) also lead to Compositions with a significantly improved breaking and Impact resistance of the resulting polymers.

The polymerizable (meth) acrylates (A) are monomers or Monomer mixtures or from polymerizable Polimerisable (meth) acrylate-containing monomers Oligomeric or polymerizable polymers, e.g. B. Macromonomers. The notation (meth) acrylate includes here and below generally all C = C-unsaturated compounds with neighboring conjugated carboxyl group and in particular all acrylates and Methacrylates.

Examples of preferred monomers are (meth) acrylic acid and the C ₁ -C ₂₄ -alkyl esters of (meth) acrylic acid, such as methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclohexylmethyl (meth) acrylate, tricyclodecyl (meth) acrylate; Tetraethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, butanediol di (meth) acrylate, hexanediol di (meth) acrylate, decanediol di (meth) acrylate, d meth) acrylate, 2- (hydroxyethyl) - (meth) acrylate, 3- (hydroxypropyl) (meth) acrylate, bisphenol-A-di (meth) acrylate, trimethylolpropane tri (meth) acrylate, siloxane-containing (meth) acrylates, such as bis ( meth) acryloxy-alkylene-disiloxanes and oligosiloxanes with a C ₁ -C ₁₈ alkylene radical, as well as the products of the reactions of isocyanates with methacrylates containing OH groups. Examples of the last-mentioned products are the products obtained by reacting 1 mol of hexamethylene diisocyanate with 2 mol of 2-hydroxyethylene methacrylate and 1 mol of tri (6-isocyanatohexyl) biuret with 3 mol of 2-hydroxyethyl methacrylate. Methyl (meth) acrylate and (meth) acrylic acid are particularly preferred.

For dental materials are special Triethylene glycol dimethacrylate, ethylene glycol di (meth) acrylate, 2,2-bis-4- (3-methacryloxy-2-hydroxypropoxy) phenylpropane (Bis-GMA), bis (omega-methacryloxyalkyl) disiloxane and those by Reaction of 1 mole of 2,2,4-trimethylhexamethylene diisocyanate with 2 Mol products obtained 2-hydroxyethyl methacrylate preferred.

The use of polyfunctional (meth) acrylates leads to Formation of cross-linked materials that continue through distinguish improved properties.

Oligomeric (meth) acrylates are made from 2 to 5 (meth) acrylate-A units, polymer (meth) acrylates are made at least 6 (meth) acrylate units, preferably of built up at most 30 (meth) acrylate units.

Mono- or polyfunctional (meth) acrylates are preferred used.

The polymerizable material can also contain other polymers, such as pearl polymers of methyl methacrylate or of mixtures from methyl methacrylate with other (meth) acrylates.

The amount of polymerizable (meth) acrylates is preferably at least 10% by weight, in particular at least 20 % By weight of the total amount of the polymerizable composition and preferably at most 90% by weight, in particular at most 60 % By weight of the total amount of the polymerizable composition.

Organopolysiloxane particles (B) are those from EP-A-744 432 known organopolysiloxane particles used.

The organopolysiloxane particles (B) typically have average molecular weights of at least 10 ⁵ , in particular 5 × 10 ⁵ to at most 10 ¹⁰ , in particular 10 ⁹ . The average diameters of the organopolysiloxane particles (B) are preferably at least 10 and at most 150 nm. At least 80% of the particles preferably have a diameter which deviates from the average diameter by at most 20%, in particular at most 10%.

The organopolysiloxane particles (B) are preferably spherical microgels.

The organopolysiloxane particles (B) are intramolecularly cross-linked, but have no intermolecular networking between the Organopolysiloxane particles (B). That is why they are Organopolysiloxane particles (B) readily soluble in solvents.

The solvent in which the organopolysiloxane particles (B) to solve at least 5 wt .-% depends on the structure of the Organopolysiloxane particles (B) and in particular from themselves the surface of the organopolysiloxane particles (B) Groups from. For all organopolysiloxane particles (B) there is one suitable solvent.

The solubility of the organopolysiloxane particles (B) will determined for example at 20 ° C. Particularly suitable as Solvent for organopolysiloxane particles (B) with Hydrocarbon residue is toluene, for Organopolysiloxane particles (B) with amino residues With tetrahydrofuran and for organopolysiloxane particles (B) Sulfonate residues is water. For example Organopolysiloxane particles (B) with hydrocarbon residues in Toluene almost unlimited and in liquid polydimethylsiloxane with a viscosity of 35 mPa.s at 25 ° C up to 15% by weight soluble. The organopolysiloxane particles (B) are preferably in a solvent selected from toluene, Tetrahydrofuran and water, at least 10% by weight, in particular at least 15% by weight soluble.

The organopolysiloxane particles (B) are preferably composed of
0.5 to 80.0% by weight of units of the general formula

[R ₃ SiO _1/2 ] (1),

0 to 99.0% by weight of units of the general formula

[R ₂ SiO _2/2 ] (2),

0 to 99.5% by weight of units of the general formula

[RSiO _3/2 ] (3),

0 to 80.0% by weight of units of the general formula

[SiO _4/2 ] (4) and

0 to 20.0% by weight of units of the general formula

[R _a Si (O _{(3-a) / 2} ) -R ¹ -X- (R ¹ -Si (O _{(3-a) / 2} )) _b R _a ] (5),

in which
R is a hydrogen atom or the same or different monovalent SiC-bonded, optionally substituted C ₁ to C ₁₈ hydrocarbon radicals,
R ^{1 are} identical or different divalent SiC-bonded, optionally substituted C ₁ - to C ₁₈ -hydrocarbon radicals, which are formed by double-bonded radicals from the group -O-, -COO-, -OOC-, -CONR ² - , -NR ² CO- and -CO- can be interrupted,
R ^{1 is} a hydrogen atom or a radical R,
X is a radical from the group -N = N-, -OO-, -SS- and -C (C ₆ H ₅ ) ₂ -C (C ₆ H ₅ ) ₂ -,
a the values 0, 1 or 2 and,
b is the value 0 or 1,
with the proviso that the sum of the units of the general formulas (3) and (4) is at least 0.5% by weight.

Examples of unsubstituted radicals R are alkyl radicals, such as the Methyl, ethyl radical; Cycloalkyl radicals, such as cyclohexyl radical; Aryl radicals, such as the phenyl, biphenylyl, naphthyl, anthryl and Phenanthryl residue; Alkaryl residues, such as o-, m-, p-tolyl residues, Xylyl residues and ethylphenyl residues; Aralkyl radicals, such as the Benzyl radical, the alpha and the β-phenylethyl radical.

Examples of substituted hydrocarbon radicals as radical R are halogenated hydrocarbon radicals, mercaptoalkyl radicals; Ureidoalkyl residues; Epoxy alkyl residues; (Meth) acryloxyalkyl radicals, Cyanoalkyl residues; Aminoalkyl residues; Aminoaryl residues; quaternaries Ammonium residues; Hydroxyalkyl residues; Phosphonic acid residues; Phosphonate residues and sulfonate residues.

The radical R is preferably unsubstituted and substituted C ₁ -C ₁₈ -alkyl radicals, hydrogen and the phenyl radical, in particular the methyl, ethyl, propyl, octyl, hexyl, dodecyl, octadecyl, Phenyl, vinyl, allyl, methacryloxypropyl, 3-chloropropyl, 3-mercaptopropyl, 3-hydroxypropyl, 3- (2,3-dihydroxypropoxy) propyl, 3-aminopropyl and den (2-aminoethyl) -3-aminopropyl residue, hydrogen and quaternary ammonium residues.

Examples of divalent hydrocarbon radicals R ¹ are saturated alkylene radicals, such as the methylene and ethylene radical, and also propylene, butylene, pentylene, hexylene, cyclohexylene and octadecylene radicals, or unsaturated alkylene or arylene radicals, such as the hexenylene radical and phenylene radicals, and in particular radicals of the formula (6)

- (CH ₂ ) ₃ N (R ³ ) -C (O) - (CH ₂ ) ₂ -C (CN) (CH ₃ ) - (6),

in the
R ^{3 represents} a hydrogen atom, a methyl or cyclohexyl radical and (7)

- (CH ₂ ) ₃ -OC (O) - (CH ₂ ) ₂ -C (O) - (7).

Preferred radicals X are -N = N- and -O-O-.

Particularly preferred units of the general formula (5) fall under the general formula (8)

[(CH ₃ ) _a Si (O ( _{3-a) / 2} ) - (CH ₂ ) ₃ -N (R ³ ) -C (O) - (CH ₂ ) ₂ -C (CN) (CH ₃ ) - N =] ₂

in which a and R ^{3 have} the meanings given above.

The organopolysiloxane particles (B) preferably contain
1 to 80.0% by weight of units of the general formula (1),
0 to 98.0% by weight of units of the general formula (2),
0 to 99.0% by weight of units of the general formula (3),
0 to 50.0% by weight of units of the general formula (4) and
0 to 10.0% by weight of units of the general formula (5)
with the proviso that the sum of the units of the general formulas (3) and (4) is at least 1% by weight.

In particular, the organopolysiloxane particles (B) contain
5 to 50.0% by weight of units of the general formula (1),
0 to 94.0% by weight of units of the general formula (2),
1 to 95.0% by weight of units of the general formula (3),
0% by weight of units of the general formula (4) and
0 to 5.0% by weight of units of the general formula (5).

Preferably on the surfaces of the Organopolysiloxane particles (B) at least 1 wt .-%, in particular at least 5% by weight of residues R which are selected from (Meth) acryloxyalkyl radicals, such as methacryloxypropyl radical and Methacryloxypropyl ester; Epoxy alkyl residues such as glycidyl residue;  Mercaptoalkyl, aminoalkyl, ureidoalkyl and alkenyl radicals, like vinyl scraps.

The organopolysiloxane particles (B) are preferably produced in a process in which, in a first step, by metering in silanes of the general formula (9)

R _c Si (OR ⁴ ) _4-c (9),

and optionally organosilicon compounds of the general formula (10)

R _d (R ⁴ O) _e SiO _{4-de / 2} (10),

and optionally organosilicon compounds from units of the general formula (11)

R _a Si ((OR ⁴ ) _3-a ) -R ¹ -X- (R ¹ -Si (OR ⁴ ) _3-a )) _b R _a (11),

in which
R ^{4 is} the meaning of R,
c the values 0, 1, 2 or 3,
d and e each independently have the values 0, 1, 2, 3 or 4 and
R, X, a and b have the meanings given above,
a colloidal suspension of organopolysiloxane particles is made into a moving mixture of emulsifier and water and
in a second step the colloidal suspension with organosilicon compound of the general formula (12)

(R ⁵ ₃ Si) _f Y ¹ (12),

is displaced, whereby
Y ¹ for the meanings f = 1 is a hydrogen atom, -OR ⁶ , ONR ⁶ ₂ or -OOCR ⁶ and
for the meanings f = 2 means -O- or -S-,
R ⁵ and R ^{6 have} the meanings of R and
f have the values 1 or 2,
with the proviso that the organosilicon compounds of the general formula (12) are water-soluble or hydrolyze in water to form a water-soluble compound.

The interparticular condensation of the organopolysiloxane particles is prevented by following the first step remaining, condensable groups with exclusively containing monofunctional triorganosilyl groups organosilicon compounds are saturated.

In the hydrolysis or Condensation reaction of the organosilicon compounds of the general formula (12) no by-products such as hydrochloric acid or Ammonia is formed, which is the ionic strength of the aqueous colloidal Systems significantly enlarge. Are particularly preferred as organosilicon compounds of the general formula (12) Trimethylmethoxysilane, trimethylethoxysilane, Hexamethyldisiloxane, vinyldimethylmethoxysilane, Vinyldimethylethoxysilane, 1,1,3,3-tetramethyldisiloxane and Mixtures of these are used.

The isolation of the organopolysiloxane particles from the colloidal suspensions after completion of the second Reaction step can be carried out according to known methods, for example by coagulation of the latices by adding salt or by adding polar solvents.

Organopolysiloxane particles, which in total contain more than about 15% by weight of units of the general formulas (3) and (4), are preferably isolated after the second step in a third reaction step in an aprotic solvent with organosilicon compound of the general formula (13) and / or (14)

(R ⁵ ₃ Si) _f Y ² (13),

offset, whereby
Y ² for the meanings f = 1 hydrogen, halogen atoms, -OR ⁶ , -NR ⁶ ₂ , -ONR ⁶ ₂ or -OOCR ⁶ and for the meanings f = 2 -O-, -N (R ⁶ ) - or - S-,
Y ^{3 is} the radicals -O-, -N (R ⁶ ) - or -S-,
g values from 1 to 30, in particular 2, 3 or 4, and f, R ⁵ and R ^{6 have} the above meanings.

In the third step, organosilicon is preferred Compounds of the general formula (13) are used.

Organic silicon compounds are particularly preferred of the general formula (13) in this third reaction step Trimethylchlorosilane, dimethylchlorosilane, Vinyldimethylchlorosilane, hexamethyldisilazane, 1,3-divinyl 1,1,3,3-tetramethyldisilazane, or mixtures of disilazanes or chlorosilanes used.

The amounts of compounds of the general formulas used (9) to (14) are chosen so that the desired ones Organopolysiloxane particles can be obtained. The used Amounts of compounds of the general formulas (9) to (11) are installed almost quantitatively in the first reaction step and control the degree of crosslinking of the organopolysiloxane particles in aqueous suspension. The in the second and possibly in third reaction step used compounds of  general formulas (12) and (13) and (14) are each in Excess used and therefore not completely in the Organopolysiloxane particles incorporated. Preferably 0.2 to 10, in particular 0.5 to 3 parts by weight of compounds of general formulas (12) in the second reaction step, or the Sum of the compounds of the general formulas (12), (13) and (14) in the second and third reaction steps, per part by weight on compounds of the general formulas (9) to (11) used.

If a third reaction step is carried out, the ratio of those used in the second reaction step Amount of compounds of the general formulas (12) to that in third reaction step used amount of compounds of the general formulas (13) and (14) preferably 1:10 to 2: 1, especially 1: 5 to 1: 1.

The radical R ⁶ is preferably unsubstituted C1 to C6 alkyl radicals and the phenyl radical, methyl, ethyl and propyl radicals being particularly preferred.

Particularly suitable emulsifiers are alkyl sulfates, e.g. B. with a chain length of 8-18 carbon atoms, aryl and alkyl ether sulfates with 8-18 carbon atoms in the hydrophobic radical and 1-40 ethylene oxide (EO) or propylene oxide (PO) units;
Sulfonates, e.g. B. alkyl sulfonates with 8-18 C atoms, alkylarylsulfonates with 8-18 C atoms, esters and half esters of sulfosuccinic acid with monohydric alcohols or alkylphenols with 4-15 C atoms; optionally these alcohols or alkylphenols can also be ethoxylated with 1-40 EO units;
Alkali and ammonium salts of carboxylic acids with 8-20 C atoms in the alkyl, aryl, alkaryl or aralkyl radical;
Phosphoric acid partial esters and their alkali and ammonium salts, e.g. B. alkyl and alkaryl phosphates with 8-20 C atoms in the organic radical, alkyl ether or alkaryl ether phosphates with 8-20 C atoms in the alkyl or alkaryl radical and 1-40 EO units;
Alkyl polyglycol ether with 2-40 EO units and alkyl residues of 4-20 C atoms;
Alkylaryl polyglycol ethers with 2-40 EO units and 8-20 C atoms in the alkyl and aryl radicals;
Ethylene oxide / propylene oxide (EO / PO) block copolymers with 8-40 EO or PO units;
Fatty acid polyglycol esters with 6-24 C atoms and 2-40 EO units;
Alkyl polyglycosides, natural products and their derivatives, such as lecithin, lanolin, saponins, cellulose; Cellulose alkyl ethers and carboxyalkyl celluloses, the alkyl groups of which each have up to 4 carbon atoms;
linear organo (poly) siloxanes containing polar groups with alkoxy groups with up to 24 C atoms and / or up to 40 EO and / or PO groups;
Salts of primary, secondary and tertiary fatty amines with 8-24 C atoms with acetic acid, sulfuric acid, hydrochloric acid and phosphoric acids;
Quaternary ammonium salts such as halides, sulfates, phosphates, acetates or hydroxides, the alkyl groups of which have, independently of one another, 1-24 C atoms; optionally the alkyl or alkaryl or aralkyl groups of the quaternary ammonium compounds can also be partially ethoxylated (1-40 EO units);
Alkylpyridinium, alkylimidazolinium and alkyloxazolinium salts, the alkyl chain of which has up to 18 carbon atoms, in the form of their halides, sulfates, phosphates or acetates.

Aliphatic substituted benzenesulfonic acids and their salts and optionally partially ethoxylated quaternary Ammonium halides and hydroxides. Are particularly preferred Dodecylbenzenesulfonic acid and benzyldimethyl - {- [2- (p-1,1,3,3- tetramethylbutylphenoxy) ethoxy] ethyl} ammonium chloride (Benzethonium chloride).

The amount of emulsifier to be used is from 0.5-50% by weight, preferably from 1.0-30% by weight, in each case based on the total amount of organosilicon starting compounds used in the first and second reaction step. The organosilicon starting compounds of the general formulas (9) to (11) are preferably metered in during the first reaction step. Preferably, all starting components of the general formulas (9) to (11) are mixed in the desired ratio before metering during the first reaction step; In order to obtain a homogeneous mixture, an additional 0.1-30% by weight, based on the sum of the starting components of the general formulas (9) to (11), alkanol of the formula R ⁷ OH, in which R ^{7 is} an alkyl radical, is optionally added 1 to 5 carbon atoms is added as a solubilizer, with the alkanols methanol and ethanol being particularly preferred.

In the third step, the above-described ethers, hydrocarbons, ketones and organopolysiloxanes, in particular tetrahydrofuran, cyclohexane, methylcyclohexane or toluene, are preferably used as the aprotic organic solvent. The reaction both in the first (emulsion polycondensation / polymerization) and in the second reaction step is preferably carried out at 5-95 ° C., in particular at 10-85 ° C. and particularly preferably at 10-40 ° C. The pH is in each case from 1-12, preferably from 1-4 or from 7-11, depending on the acid / base stability of the radicals R, R ⁴ , R ⁵ and R ^{6 of} the starting compounds (9) to (13 ).

In the preparation of the colloidal suspensions during the first reaction step is for the stability of the Emulsion advantageous after the end of the dosing organosilicon starting compounds of the general Stir formulas (9) to (11) for 1 to 24 hours. The Alkanol released in the hydrolysis can be distilled, possibly under reduced pressure, but this is not the case is preferred. The fixed salary after the first step Colloidal suspension produced should be preferred amount to a maximum of 25% by weight, otherwise a high increase in the Viscosity complicates further implementation. When implementing the colloidal suspension with organosilicon compound of the general formula (12) in the second reaction step also to achieve the most complete possible reaction advantageous after the addition of compounds of general formula (12) for a further 1-48 hours.

The implementation with organosilicon compound general formulas (13) and (14) in the third reaction step is preferably at 5-95 ° C, especially at 10-85 ° C and particularly preferably carried out at 10-40 ° C. For It is to achieve the most complete possible reaction again advantageous after the addition of the compound of general formula (13) and (14) still 1-24 hours stir.

For the structural characterization of the Organopolysiloxane particles (B) are particularly suitable static and dynamic light scattering.

A proportion of organopolysiloxane particles (B) is preferred the total amount of polymerizable compositions of at least 0.1% by weight, in particular at least 0.4% by weight, particularly preferably at least 2% by weight and at most 95% by weight, in particular at most 90% by weight, particularly preferred at most 85% by weight.  

Mixtures of Organopolysiloxane particles, which are two or more have different sizes to make the viscosity as low and that Keep fill level as high as possible. The ratio of Radii of two different sizes Organopolysiloxane particle fractions in the total mixture, between which no other faction with a intermediate size more can be between 1: 2 and 1:40, preferably between 1: 2.5 and 1:10 and particularly preferably between 1: 3.5 and 1: 6. Particular preference is given to only a size or mixtures with two parts Organopolysiloxane particles with different radii used.

In addition to the organopolysiloxane particles (B) can in the polymerizable composition also with a polysiloxane (Meth) acrylic groups (C) as impact modifiers be used.

This is preferably an oligomeric Poly (dimethylsiloxane) or polyether-polysiloxane block copolymer with a number average molecular weight of 1000 to 10000 g / mol, in particular 1000 to 4000 g / mol. Preferably that Poly (siloxane) 2 to 8 terminally and / or laterally bound Meth (acrylic groups).

These polysiloxanes with (meth) acrylic groups (C) can, for. B. by Hydrosilylation of allyl methacrylate with oligomeric or polymeric polysiloxanes with terminal or pendant Si-H bonds are made. For example, you are commercially from Tego Chemie Service, Germany, under the name of sliding additives TEGO® Rad 2500 or 2600 available.

It was found that the polysiloxanes with (meth) acrylic groups (C) excellent in liquid (meth) acrylate monomers and Have monomer mixtures redispersed and that their use  to a significantly improved impact strength in the cured polymerizable compositions.

A proportion of polysiloxanes is preferred (Meth) acrylic groups (C) on the total amount of polymerizable Compositions of at least 0.1% by weight, in particular at least 1% by weight, and at most 20% by weight, in particular at most 10% by weight.

The polymerizable compositions can also contain fillers (D), which can optionally contain polymerizable (meth) acrylate groups for connection to the polymer network or have been treated for this purpose with (meth) acrylate-containing alkoxysilanes or contain no attachable groups. Examples of fillers (D) which are particularly suitable are glass ceramic powders treated with or without alkoxysilanes, aluminum oxides, mixed oxides such as SiO ₂ / ZrO ₂ mixed oxides, or radiopaque fillers such as ytterbium fluoride. Glass powder, precipitated or pyrogenic silica, barium silicate glass, lithium or aluminum silicate glass powder is particularly preferred.

Fillers (D) are preferably used in a total amount of preferably at most 95% by weight, in particular at most 90% by weight and particularly preferably at most 80% by weight in the polymerizable compositions used.

The polymerizable compositions can, for example in the presence of polymerization initiators (E) by light, are polymerized hot or cold, preferably one polymer network forms.

Light-curing initiators (E) are benzophenone and its Derivatives and benzoin and its derivatives. More preferred Photoinitiators (E) are alpha-diketones, such as 9,10-phenanthrenequinone, diacetyl, furil, anisil, 4,4'-dichlorobenzil and 4,4'-dialkoxybenzil. Camphorquinone is particularly preferred used. In addition, the group of Acylphosphine oxides are good for initiating photopolymerization.  

The photoinitiators are used to accelerate the initiation (E) preferably together with a reducing agent, especially preferably with an amine, in particular an aromatic amine used. Examples of this are combinations of Camphorquinone and benzoyl peroxide with N, N-dimethyl-para-toluidine or N, N-cyanoethylmethylaniline.

In hot polymerization, azo compounds such as 2,2'-azoisobutyronitrile (AIBN), benzpinacol and 2,2'-Dialkylbenzpinakole be used or peroxides, such as Dibenzoyl peroxide, dilauryl peroxide, tert-butyl peroctoate or tert-butyl perbenzoate.

For cold curing, initiators (E) can be used in redox systems use, such as benzoyl or lauroyl peroxide together with amines such as N, N-dimethyl-p-toluidine, N, N-bis- (2- hydroxyethyl) -p-toluidine or other structurally related amines. Substituted ones are also particularly suitable Barbituric acids such as 1-benzyl-5-phenyl-, 5-n-butyl- or 1-cyclohexyl-5-ethylbarbituric acid.

The amount of initiators (E) is preferably in the range of 0.05 to 1.5% by weight, particularly preferably in the range from 0.2 to 0.8 wt .-% based on the amount of in the polymerizable Compositions of average monomers present.

The polymerization of the compositions can take place both in Substance as well as take place in an emulsion polymerization.

The polymerizable compositions can also Bead polymers of (meth) acrylates contain the Volume shrinkage as low as possible during the polymerization hold.

For setting certain properties, the polymerizable compositions and other additives such as Contain pigments and polymerization stabilizers.  

The by polymerizing the polymerizable Polymers available are compositions as well Subject of the invention.

The polymerizable compositions are suitable, for example, for all fields of use where acrylate-containing compositions (without particles) are used. These are in particular

• a) the production of (meth) acrylate-based molding compositions and Casting compounds of all kinds, such as. B. transparent masses Production of household items, in Automotive sector and in the technical, industrial area as Glass replacement for processing reasons (form of hardened mass or for reasons of lower density in the Compared to glass) z. B. for greenhouses, light housings, transparent device housing, household items, rulers, Telephone dials, lenses, optical fibers, decorative Objects, car taillights, glasses and contact lenses. So z. B. in addition to the shrinkage reduction also more important polymer properties, such as hardness and calculation index, by the particles according to the invention in the acrylic ones Compositions are modified.
• b) filled systems, e.g. B. in the dental field, such as tooth fillings, artificial teeth, bridges, inlays, crowns, temporary restorations, Prostheses and denture plates and in the household and sanitary sector (e.g. sink, kitchen sink, countertops, handles, Covers)
• c) Applications in thin layers, e.g. B. in the form of (Meth) acrylate-containing coating systems on substrates, such as Metal, glass, wood, plastic, paper, mineral Substrates such as concrete, clay, ceramics, stone, etc., both as Basecoat, as well as a topcoat system, e.g. B. as scratch-resistant Top layer.  
• d) Applications for coating fabrics and grids etc. from textile fabrics, mineral fabrics or Glass fiber fabrics, metal grids, e.g. B. for textile construction.
• e) the use for laminating textile, mineral or glass fiber fabrics.

When using the polymerizable composition in the Dental areas are particularly the smaller volume loss in the polymerization along with low viscosity and better Processability advantageous, what a dental mass in Composite area combined with high breaking and Impact resistance and possibly high transparency is particularly advantageous.

Claims (9)

1. Polymerizable compositions which

• A) polymerizable (meth) acrylate and
• B) Organopolysiloxane particles, which consist of a single molecule, are crosslinked, have an average diameter of 5 to 200 nm and are soluble in a solvent which is selected from toluene, tetrahydrofuran and water at 20 ° C. to at least 5% by weight are and in which at least 80% of the particles have a diameter which deviates at most 30% from the mean diameter.

2. Polymerizable compositions according to claim 1, which the polymerizable (meth) acrylate (A) monomers or monomer mixtures or from polymerizable Oligomers constructed from (meth) acrylate-containing monomers or Are polymers. 3. Polymerizable compositions according to claim 1 or 2, in which the amount of polymerizable (meth) acrylates at least 10% by weight and at most 90% by weight of the total the polymerizable composition. 4. Polymerizable compositions according to claims 1 to 3, in which the organopolysiloxane particles (B) are composed of 0.5 to 80.0% by weight of units of the general formula
[R ₃ SiO _1/2 ] (1),
0 to 99.0% by weight of units of the general formula
[R ₂ SiO _2/2 ] (2),
0 to 99.5% by weight of units of the general formula
[RSiO _3/2 ] (3),
0 to 80.0% by weight of units of the general formula
[SiO _4/2 ] (4) and
0 to 20.0% by weight of units of the general formula
[R _a Si (O _{(3-a) / 2} ) -R ¹ -X- (R ¹ -Si (O _{(3-a) / 2} )) _b R _a ] (5),
in which
R is a hydrogen atom or the same or different monovalent SiC-bonded, optionally substituted C ₁ to C ₁₈ hydrocarbon radicals,
R ^{1 are} identical or different divalent SiC-bonded, optionally substituted C ₁ - to C ₁₈ -hydrocarbon residues which are formed by double-bonded residues from the group -O-, -COO-, -OOC-, -CONR ² - , -NR ² CO- and -CO- can be interrupted,
R ^{2 is} a hydrogen atom or a radical R,
X is a radical from the group -N = N-, -OO-, -SS- and -C (C ₆ H ₅ ) ₂ -C (C ₆ H ₅ ) ₂ -,
a the values 0, 1 or 2 and,
b is the value 0 or 1,
with the proviso that the sum of the units of the general formulas (3) and (4) is at least 0.5% by weight. 5. Polymerizable compositions according to claim 1 to 4, in the proportion of organopolysiloxane particles (B) in the Total amount of polymerizable compositions is at least 0.1% by weight and at most 50% by weight.   6. Polymerizable compositions according to claim 1 to 5, in which an additional maximum of 80% by weight of fillers (D) are present. 7. Polymerizable compositions according to claim 1 to 6, in which polymerization initiators (E) are present. 8. Polymers obtainable by polymerizing the polymerizable compositions according to one of the Claims 1 to 7. 9. Use of the polymerizable compositions after Claims 1 to 7 and the polymers according to claim 8 in Dental field.