Silicone release coating compositions
AssigneeDow Corning Corporation
InventorsKyuha Chung, Robert Alan Ekeland, Randall Gene Schmidt
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Abstract
The present invention relates to a curable silicone release coating composition comprising (A) an organopolysiloxane having at least two alkenyl groups per molecule, (B) an organohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule, (C) a siloxane resin having silicon-bonded hydrogen groups, (D) a platinum group metal-containing catalyst, and optionally (E) an inhibitor. The compositions of this invention are useful as release coatings for pressure sensitive adhesives.
Claims27
A curable silicone release coating composition comprising:
- (A) an organopolysiloxane having at least two alkenyl groups per molecule;
- (B) a linear organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule;
- (C) a siloxane resin having the formula (R.sub.3 SiO.sub.1/2).sub.a (HR.sub.2 SiO.sub.1/2).sub.b (SiO.sub.4/2).sub.c wherein R is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, a has a value of 1 to 25, b has a value of 2 to 10, c has a value of 1 to 50, and having a molar ratio of M units to Q units of from 0.6/1 to 4/1 wherein M denotes the monovalent (R.sub.3 SiO.sub.1/2).sub.2 units and the monovalent (HR.sub.2 SiO.sub.1/2).sub.b units and Q denotes the tetravalent (SiO.sub.4/2).sub.c units;
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- (D) a platinum group metal-containing catalyst.
A curable silicone release coating composition obtained by a method comprising
- (I) mixing:
- (A) an organopolysiloxane having at least two alkenyl groups per molecule;
- (B) a linear organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule;
- (C) a siloxane resin having the formula (R.sub.3 SiO.sub.1/2).sub.a (HR.sub.2 SiO.sub.1/2).sub.b (SiO.sub.4/2).sub.c wherein R is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, a has a value of 1 to 25, b has a value of 2 to 10, c has a value of 1 to 50, and having a molar ratio of M units to Q units of from 0.6/1 to 4/1 wherein M denotes the monovalent (R.sub.3 SiO.sub.1/2).sub.a units and the monovalent (HR.sub.2 SiO.sub.1/2).sub.b units and Q denotes the tetravalent (SiO.sub.4/2).sub.c units;
- and
- (D) a platinum group metal-containing catalyst.
A coated substrate obtained by a method comprising
- (I) applying a curable silicone composition on the surface of a substrate wherein the curable silicone composition is obtained by mixing:
- (A) an organopolysiloxane having at least two alkenyl groups per molecule;
- (B) a linear organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule;
- (C) a siloxane resin having the formula (R.sub.3 SiO.sub.1/2).sub.a (HR.sub.2 SiO.sub.1/2).sub.b (SiO.sub.4/2).sub.c wherein R is a monovalent hydrocarbon group having from 1 to 10 carbon atoms, a has a value of 1 to 25, b has a value of 2 to 10, c has a value of 1 to 50, and having a molar ratio of M units to Q units of from 0.6/1 to 4/1 wherein M denotes the monovalent (R.sub.3 SiO.sub.1/2).sub.a units and the monovalent (HR.sub.2 SiO.sub.1/2).sub.b units and Q denotes the tetravalent (SiO.sub.4/2).sub.c units;
- and
- (D) a platinum group metal-containing catalyst.
Dependencies are inferred from the claim text.