Method of preparing in situ reinforced silicone elastomer
AssigneeDow Corning Corporation
InventorsDebora F. Bergstrom, Gary T. Burns, Patricia A. Giwa-Agbomeirele
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Abstract
A method for preparing in situ reinforced silicone elastomers and the compositions prepared by the method. The method comprises forming a mixture comprising a diorganosiloxane polymer having reactive end-terminal functionality, a stoichiometric excess of a reactive siloxane selected from a group consisting of triorganosilyl endblocked reactive siloxanes and reactive cyclosiloxanes, and a tin salt catalyst and contacting the mixture with water to effect curing. The resulting silicone elastomers are in situ reinforced to provide high strength.
Claims18
A method for preparing an in situ reinforced silicone elastomer, the method comprising:
- (A) forming a mixture comprising a diorganosiloxane polymer described by formula
- Q.sub.3-a R.sub.a Si(OSiR.sub.2).sub.x OSiR.sub.a Q.sub.3-a,
- a stoichiometric excess of a reactive siloxane selected from a group consisting of triorganosilyl endblocked reactive siloxanes described by formula
- R.sub.3 Si(OSiQR).sub.z OSiR.sub.3
- and reactive cyclosiloxanes described by formula
- (OSiQR).sub.y,
- and a tin salt catalyst and
- (B) contacting the mixture with water to effect curing of the mixture to form an in situ reinforced silicone elastomer;
- where each R is independently selected from a group consisting of alkyls comprising one to six carbon atoms, alkenyls comprising two to six carbon atoms, and aryls;
- each Q is independently selected from a group consisting of hydroxy, acyloxys, oximos described by formula --ON.dbd.CR.sup.1.sub.2 where each R.sup.1 is an independently selected alkyl comprising one to 12 carbon atoms, alkoxys comprising one to six carbon atoms, and substituted alkoxy comprising one to six carbon atoms;
- a=0 to 2, x=0 to 1000;
- z=3 to 500, and y=3 to 10.
Dependencies are inferred from the claim text.