Silicone-containing graft copolymers based on styrene oxide-based silicone polyethers

Abstract

The invention relates to silicone-containing graft copolymers and to processes for their preparation. In particular, the invention relates to silicone-containing graft copolymers which are obtained by the controlled grafting of olefinic monomers onto a partly styrene oxide-based silicone polyether.

Description

Claims

1. A copolymer prepared by grafting ethylenically unsaturated compounds A onto silicone polyethers B which consist of a silicone moiety and a polyether moiety which bears at least one styrene oxide unit as a chain constituent in the presence of an agent which produces free radicals.

2. The copolymer as claimed in claim 1, wherein the silicone polyethers B used as the graft base are described by formula V

3. The copolymer according to claim 2, wherein all R1 radicals are methyl radicals.

4. The copolymer as claimed in claim 1, wherein the ethylenically unsaturated compounds A are ethylenically unsaturated monomers.

5. The copolymer as claimed in claim 1, wherein the ethylenically unsaturated compounds A are a mixture of a plurality of ethylenically unsaturated monomers A.

6. The copolymer as claimed in claim 1, wherein the ethylenically unsaturated compounds A are polymeric olefins having at least one radical of unsaturation.

7. The copolymer as claimed in claim 1, wherein the ethylenically unsaturated compounds A are selected from a mixture of a plurality of ethylenically unsaturated monomers A and polymeric olefins having at least one radical of unsaturation.

8. The copolymer as claimed in claim 1, wherein between 2 and 500% by weight of the ethylenically unsaturated compounds A are polymerized in the presence of the silicone polyether.

9. The polymer as claimed in claim 1, wherein the ethylenically unsaturated monomers A are selected to an extent of from 2 to 100% by weight from the group of the derivatives of acrylic acid and methacrylic acid, vinyl ethers, vinyl alcohols, vinyl esters, styrene, derivatives of styrene, and mixtures of these monomers.

10. The polymer as claimed in claim 9, wherein the derivatives of acrylic acid and methacrylic acid are described by general formula I R8O—C(O)CR7═CHR6  (I)

11. The polymer as claimed in claim 1, wherein the ethylenically unsaturated monomers A are selected to an extent of from 2 to 100% by weight and are selected from the group of styrene, methylstyrene, tert-butylstyrene and other styrene derivatives, and from mixtures of these monomers.

12. The polymer as claimed in claim 1, wherein the ethylenically unsaturated monomers A are selected to an extent of from 2 to 100% by weight and are selected from the group of the vinyl and allyl esters of C1-C40 linear, C3-C40 branched-chain or C3-C40 carbocyclic carboxylic acids, vinyl or allyl halides, and from mixtures of these monomers.

13. A method of forming a copolymer comprising grafting ethylenically unsaturated compounds A onto silicone polyethers B which consist of a silicone moiety and a polyether moiety which bears at least one styrene oxide unit as a chain constituent in the presence of an agent which produces free radicals.

14. A method for defoaming or deaerating a nonaqueous system based on mineral oils or synthetic oils comprising adding a copolymer according to claim to said nonaqueous system.

15. The method as claimed in claim 13 wherein said copolymer is added in an amount below 150 ppm based on the oil components.

16. The method according to claim 15 wherein said copolymer is added in an amount between 10 and 100 ppm.

17. A nonaqueous system comprising at least one of a mineral oil and a synthetic oil and below 150 ppm of a copolymer according to claim 1.