Alkenyl group containing siloxane copolymers, their preparation and their use

Claim 2

Crosslinkable compositions according to Claim 1, characterized in that (D) inhibitors are contained.

Claim 3

Crosslinkable compositions according to Claim 1 or 2, characterized in that (A) siloxane copolymers containing alkenyl groups used are those which comprise (a) siloxane units of the formula R 2 SiO     (I') (b) on average more than one siloxane unit, per molecule, of the formula AR 2 SiO 1/2 (II') and (c) on average at least one unit, per molecule, chosen from the group comprising units of the formulae O 1/2 R 2 Si-A 1 -SiR 2 O 1/2 (III') and in which R are identical or different, optionally halogenated hydrocarbon radicals having 1 to 18 carbon atoms per radical, A denotes a radical of the formula -CH 2 CHR 3 -R 2 (CHR 3 =CH 2 ) x-1 in which R 2 denotes a divalent, trivalent or tetravalent hydrocarbon radical having 1 to 25 carbon atoms per radical, R 3 denotes a hydrogen atom or an alkyl radical having 1 to 6 carbon atoms per radical and x denotes 2, 3 or 4, A 1 denotes a radical of the formula in which R 2 , R 3 and x have the meaning given above for these symbols and A 2 denotes a radical of the formula in which R 2 , R 3 and x have the meaning given above for these symbols, with the proviso that R2 [sic] is not a divalent hydrocarbon radical, with the proviso that the siloxane copolymers containing alkenyl groups have a viscosity of at most 500,000 mPa.s at 25°C and on average at least two alkenyl groups, per molecule, of the formula -CR 3 =CH 2 in which R 3 has the meaning given above for this symbol.

Claim 4

Crosslinkable compositions according to Claim 1, 2 or 3, characterized in that (A) siloxane copolymers containing alkenyl groups used are those in which the radical R 3 is a hydrogen atom.

Claim 5

Use of the compositions according to one of Claims 1 to 4 for the production of non-stick coatings.

Claim 6

Siloxane copolymers containing alkenyl groups, comprising (a) siloxane units of the formula R a Si(OR 1 ) b O ​ 4-(a+b) 2 in which R denotes identical or different, optionally halogenated hydrocarbon radicals having 1 to 18 carbon atoms per radical, R 1 denotes identical or different alkyl radicals having 1 to 4 carbon atoms per radical, which can be substituted by an ether oxygen atom, a is 0, 1, 2 or 3, b is 0, 1, 2 or 3 and the sum of a+b is not greater than 3, (b) at least one siloxane unit, per molecule, of the formula AR c SiO ​ 4-(c+1) 2 in which R has the meaning given above for this symbol, c is 0, 1 or 2 and A denotes a radical of the formula -CH 2 CHR 3 -R 2 (CR 3 =CH 2 ) x-1 in which R 2 denotes a divalent, trivalent or tetravalent hydrocarbon radical having 1 to 25 carbon atoms per radical, R 3 denotes a hydrogen atom or an alkyl radical having 1 to 6 carbon atoms per radical and x denotes 2, 3 or 4, and (c) on average at least one unit, per molecule, chosen from the group comprising units of the formulae O ​ 4-(c+1) 2 R c Si-A 1 -SiR c O ​ 4-(c+1) 2 and in which R and c have the meaning given above for these symbols, A1 [sic] denotes a radical of the formula in which R 2 , R 3 and x have the meaning given above for these symbols, A 2 denotes a radical of the formula in which R 2 , R 3 and x have the meaning given above for these symbols, with the proviso that R2 [sic] is not a divalent hydrocarbon radical, and A 3 is a radical of the formula in which R 2 and R 3 have the meaning given above for these symbols, with the proviso that R 2 is not a divalent or trivalent hydrocarbon radical, with the proviso that the siloxane copolymers containing alkenyl groups have a viscosity of at most 500,000 mPa.s at 25°C and on average at least two alkenyl groups, per molecule, of the formula -CR 3 =CH 2 in which R 3 has the meaning given above for this symbol, and with the proviso that linear organopolysiloxanes comprising the following recurring units -[CH 2 ] a' -[R' 2 SiO] b' -R' 2 Si- in which R' is a saturated aliphatic or aromatic group and each R' can be identical or different, a' denotes 5 to 100 and b' denotes 1 to 1000 and the organopolysiloxanes are terminated at the -[CH 2 ] a' end by -CH=CH 2 or hydrogen and at the -R' 2 Si end by -[CH 2 ] a' -CH=CH 2 or hydrogen, at least one -CH=CH 2 group being present, are excluded.

Claim 7

Process for the preparation of the siloxane copolymers containing alkenyl groups according to Claim 6, characterized in that an organic compound (1) containing at least two aliphatic double bonds, of the general formula R 2 (CR 3 =CH 2 ) x in which R 2 denotes a divalent, trivalent or tetravalent hydrocarbon radical having 1 to 25 carbon atoms per radical, R 3 denotes a hydrogen atom or an alkyl radical having 1 to 6 carbon atoms per radical and x denotes 2, 3 or 4, is reacted with an organopolysiloxane (2) having on average more than one Si-bonded hydrogen atom per molecule, in the presence of a catalyst (3) which promotes the addition of Si-bonded hydrogen onto an aliphatic double bond, the ratio employed between the aliphatic double bond in the organic compound (1) and the Si-bonded hydrogen in the organopolysiloxane (2) being 1.5 : 1 to 20 : 1, with the proviso that the reaction of a diene of the formula CH 2 =CH-(CH 2 ) a' -CH=CH 2 with an organopolysiloxane of the formula HR' 2 SiO-[R' 2 SiO] b' -SiR' 2 H in which R', a' and b' have the meaning given in Claim 6, in the presence of the catalyst (3) is excluded.

Claim 8

Process according to Claim 7, characterized in that 1,2,4-trivinylcyclohexane is used as the organic compound (1).

Claim 9

Process according to Claim 7 or 8, characterized in that the organopolysiloxane (2) used is an organopolysiloxane of the general formula H d R 3-d SiO(SiR 2 O) o (SiRHO) p SiR 3-d H d (VII) in which R denotes identical or different, optionally halogenated hydrocarbon radicals having 1 to 18 carbon atoms per radical, d denotes 0 or 1, o denotes 0 or an integer from 1 to 1000 and p denotes an integer from 1 to 6.

Claim 10

Process according to Claim 7, 8 or 9, characterized in that the siloxane copolymer containing alkenyl groups thus obtained is equilibrated with an organopolysiloxane (4) chosen from the group comprising linear organopolysiloxanes containing terminal triorganosiloxy groups, linear organopolysiloxanes containing terminal hydroxyl groups, cyclic organopolysiloxanes and copolymers of diorganosiloxane and monoorganosiloxane units.