Siloxane block copolymers
The invention provides organopolysiloxanes obtained by A) addition reaction of organopolysiloxanes containing SiH groups with vinylsiloxanes in the presence of platinum catalysts or rhodium catalysts, with the proviso that the organopolysiloxanes are present in a molar excess of at least 6 times, relative to the vinylsiloxane, and further reaction of the reaction product in at least one of the following stages: B) transition metal-catalyzed partial or complete addition reaction of the SiH groups with alkenyl and/or alkynyl compounds, C) with the use of a catalyst, partial or complete reaction of the RSiH groups, remaining after above reaction(s), with at least one alcohol from the group of linear or branched, saturated, mono- or polyunsaturated, aromatic, aliphatic-aromatic, optionally halogen atom-containing monoalcohols, polyether monoalcohols, polyester monoalcohols, and amino alcohols.
1 . An organopolysiloxane produced by the process comprising:
A) addition reaction of organopolysiloxanes of the general formula I
in which
R 1 denotes identical or different aliphatic or aromatic hydrocarbon radicals having 1 to 20 carbon atoms,
R 2 denotes R 1 or H, with the proviso that at least three radicals R 2 are H,
a is 5 to 500,
b is 1 to 50,
c is 0 to 5,
with vinylsiloxanes of the general formula II,
where
d is 10 to 1000,
in the presence of platinum catalysts or rhodium catalysts,
with the proviso that the organopolysiloxanes of the general formula I are present in a molar excess of at least 6 times, relative to the vinylsiloxane of the general formula II,
and further reaction of the reaction product in at least one of the following stages:
B) transition metal-catalyzed partial or complete addition reaction of the SiH groups with alkenyl and/or alkynyl compounds,
C) with the use of a catalyst, partial or complete reaction of the RSiH groups, remaining after above reaction(s), with at least one alcohol from the group of linear or branched, saturated, mono- or polyunsaturated, aromatic, aliphatic-aromatic, optionally halogen atom-containing monoalcohols, polyether monoalcohols, polyester monoalcohols, and amino alcohols.
2 . The organopolysiloxane as claimed in claim 1 , wherein R 1 is a methyl group.
3 . The organopolysiloxane as claimed in claim 1 , wherein boron-containing Lewis acids are used as catalyst for the addition reaction of the alcohol with the resultant SiH-containing siloxane.
4 . The organopolysiloxane as claimed in claim 3 , wherein perfluorotriphenylborane (C 5 F 4 ) 3 B is used as boron-containing Lewis acid.
5 . The organopolysiloxane as claimed in claim 3 , wherein a synergistic compound is used for the addition reaction of the alcohol, as well as boron-containing Lewis acids.
6 . The organopolysiloxane as claimed in claim 5 , wherein said synergistic compound is a salt or complex with cations selected from the group of the salts of elements of transition groups 4, 6, 7, and 8 and also of main group 4.
7 . The organopolysiloxane as claimed in claim 1 , wherein a catalytic mixture composed of at least one carboxylic acid and at least one salt of a carboxylic acid is used additionally as catalyst for the addition reaction of the alcohol with the resultant SiH-containing siloxane.
8 . The organopolysiloxane as claimed in claim 1 , wherein the viscosity is<10 000 mPas.
9 . A process of defoaming a non-aqueous solution with comprises adding the organosiloxane of claim 1 into the non-aqueous solution.
10 . A product selected from the group consisting of a finishing textile; an abhesive release coating; a UV-curing coating; an additive for UV-curing coating; an additive for plastics, paints, printing ink; and a polyurethane foam stabilizers wherein said product further comprises the organopolysiloxane of claim 1.