Primer compositions
AssigneeShin-Etsu Chemical Co., Ltd.
InventorTakehide Okami
Life of this patent
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Abstract
The primer compositions consist essentially of a mercapto-containing organosilane or organopolysiloxane as one component and a titanic acid ester as the other. They are suitable for adhesively bonding a room-temperature-curing silicone rubber elastomer irrespective of its crosslinking mechanism to various substrates. The bond obtained by use of the primer composition is very strong and highly resistant to water or sea water even on prolonged immersion at high temperatures.
Claims10
A primer composition consisting essentially of ( 1) 2 to 98 parts by weight of a mercapto-containing organosilane or organopolysiloxane represented by the average unit formula ##EQU2## where R.sup.1 is an alkylene group having 1 to 4 carbon atoms, R.sup.2 is a substituted or unsubstituted monovalent hydrocarbon group, X is a hydroxy or hydrolyzable atom or group and a, b, and c have values as expressed by 0<a.ltoreq.1, 0.ltoreq.b.ltoreq.1 and 0<c.ltoreq.3, respectively, with the proviso that a+b+c has the value as expressed by 0<(a+b+c).ltoreq.4 and (2) 98 to 2 parts by weight of a titanic acid ester.
A method for adhesively bonding a room-temperature-curing silicone rubber elastomer to a substrate which comprises applying to the surface of the substrate a primer composition consisting essentially of (1) 2 to 98 parts by weight of a mercapto-containing organosilane or organopolysiloxane represented by the average unit formula ##EQU3## where R.sup.1 is an alkylene group having 1 to 4 carbon atoms, R.sup.2 is a substituted or unsubstituted monovalent hydrocarbon group, X is a hydroxy or hydrolyzable atom or group and a, b, and c have values as expressed by 0<a.ltoreq.1. 0.ltoreq.b.ltoreq.1 and 0<c.ltoreq.3, respectively, with the proviso that a=b=c has the value as expressed by 0<(a+b+c .ltoreq. 4 and (2) 98 to 2 parts by weight of a titanic acid ester, contacting the uncured elastomer with the thus primed surface, and subjecting the thus contacted elastomer to curing conditions.
Dependencies are inferred from the claim text.