Silicone-containing graft copolymers based on styrene oxide-based silicone polyethers
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.
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
where
R f may be an R 1 radical, and
R 1 is an alkyl radical having from 1 to 16 carbon atoms or an aryl radical,
or
R f is an R 2 or R 3 radical, with the proviso that at least one R f radical is the R 2 radical, where
R 2 is a polyether radical of the formula VI
(F) q [O(C 2 H 4-d R′ d O) m (C x H 2x O) r Z] w (VI)
where
d is from 1 to 3,
m is ≧1,
q is 0 or 1,
x is from 2 to 10,
r is ≧0,
w is from 1 to 4,
F is a hydrocarbon radical which may also be branched,
R′ is a monovalent hydrocarbon radical which is aromatic or optionally also a substituted aromatic,
Z is a hydrogen atom or a monovalent organic radical such as alkyl or alkyl ester or aryl ester,
and
R 3 is a polyether radical of the formula VI
(F) q [O(C 2 H 4-d R′ d O) m (C x H 2x O) r Z] w (VI)
where
d is from 1 to 3,
m is ≧0,
q is 0 or 1,
x is from 2 to 10,
r is >1,
w is from 1 to 4,
F is a hydrocarbon radical which may also be branched,
R′ is a hydrogen radical, a monovalent hydrocarbon radical having from 1 to 18 carbon atoms,
Z is a hydrogen atom or a monovalent organic radical,
and where, in formula V,
b is from 0 to 8, and
a is from 1 to 100 when b is from 6 to 8, or
a is from 1 to 200 when b is from 3 to 6, or
a is from 1 to 300 when b is from 0 to 3.
3 . The copolymer according to claim 2 , wherein all R 1 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
R 8 O—C(O)CR 7 ═CHR 6 (I)
where
R 7 and R 6 are each independently selected from the group consisting of: —H, C 1 -C 8 linear or branched-chain alkyl chains, methoxy, ethoxy, 2-hydroxyethoxy, 2-methoxyethoxy and 2-ethoxyethyl,
R 8 is C 1 -C 40 linear, C 3 -C 40 branched-chain, aromatic or C 3 -C 40 carbocyclic alcohols, polyfunctional alcohols having from 2 to about 10 hydroxyl groups, alcohol ethers, or polyethylene glycols.
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 C 1 -C 40 linear, C 3 -C 40 branched-chain or C 3 -C 40 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 .