Room temperature stable, heat activated organopolysiloxane compositions

Claim 1

A composition obtained by a method comprising the mixing of components comprising (a) an alkenyl group-containing organopolysiloxane component comprising at least one siloxane unit having the formula R a 1 R b 2 SiO.sub.(4-a-b)/2 wherein R 1 denotes a silicon-bonded alkenyl group having from 2 to 4 carbon atoms, inclusive, R 2 denotes a silicon-bonded substituted or unsubstituted monovalent hydrocarbon group, a has a value of from 1 to 3, b has a value of from 0 to 2 and a+b has a value of from 1 to 3, all values inclusive, any remaining siloxane units in the alkenyl group-containing organopolysiloxane having the formula R x 2 SiO.sub.(4-x)/2 wherein R 2 is as denoted above and x has a value of from 0 to 3, inclusive; (b) an organohydrogenpolysiloxane component comprising at least one siloxane unit having the formula H c R d 3 SiO.sub.(4-c-d)/2 wherein R 3 denotes a silicon-bonded substituted or unsubstituted monovalent hydrocarbon group, c has a value of from 1 to 3, d has a value of from 0 to 2 and c+d has a value of from 1 to 3, all values inclusive, any remaining siloxane units in the organohydrogenpolysiloxane having the formula R y 3 SiO.sub.(4-y)/2 wherein R 3 is as denoted above and y has a value of from 0 to 3, inclusive; (c) a cure catalyzing amount of a hydrosilylation curing catalyst component for the composition; and (d) a cure inhibiting amount of an unsaturated hydrocarbon component having the formula HC.tbd.C--CR 4 ═CR 5 R 6 wherein each R 4 , R 5 and R 6 denotes, independently, a hydrogen atom, a monovalent hydrocarbon group or a divalent hydrocarbon group with the requirements that the total number of carbon atoms in the R 4 , R 5 and R 6 groups has a value of from 2 to 6 and when R 4 and R 5 or R 5 and R 6 are divalent they are bonded together by their second valence.