Adhesion of silicone elastomer to polyurethane
AssigneeDow Corning Corporation
InventorHarold V. Lefler, III
Life of this patent
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Abstract
When a silicone elastomeric coating is applied over a polyurethane foam to protect it, an adhesion problem arises. It has been found that a coating of from 0.05 to 0.2 grams per square foot of surface of a silane of the formula ZSi (OR).sub.3, where Z is an amine functional radical and R is a monovalent hydrocarbon radical having from 1 to 6 carbon atoms, applied to the polyurethane foam under the silicone elastomeric coating greatly improves the adhesion between them. The silicone elastomeric coating is a particular type of tin catalyzed silicone coating comprising a particular organosilicon resin, a hydroxy-ended silicone polymer, and filler.
Claims5
A method of improving the adhesion of a silicone elastomeric coating to a polyurethane substrate consisting essentially of applying to the polyurethane surface from 0.05 to 0.2 grams per square foot of surface of a silane of the formula ZSi(OR).sub.3 where Z is an amine functional radical and R is a monovalent hydrocarbon radical having from 1 to 6 carbon atoms, then applying a coating of a silicone elastomeric composition comprising the product obtained by mixing:
- (A) from 1.0 to 400 parts by weight of the reaction product of
- (i) an organosilicon resin consisting essentially of R".sub.3 SiO.sub.1 /.sub.2 units and SiO.sub.4/2 units, wherein R" represents a monovalent hydrocarbon radical, and the ratio of R".sub.3 SiO.sub.1/2 units to SiO.sub.4/2 units is from 0.6/1 to 0.9/1, and
- (ii) a polyorganohydrogensiloxane;
- (B) 100 parts by weight of a polydiorganosiloxane having the general formula HO(R'.sub.2 SiO).sub.x H, wherein R' represents a monovalent hydrocarbon radical and x has a value of from 10 to 1000;
- (C) from 1 to 150 parts by weight of a filler;
- and
- (D) from 0.10 to 13.3 parts by weight of an organotin catalyst.
Dependencies are inferred from the claim text.