Addition-curable silicon adhesive compositions and bis(trialkoxysilyl)alpha-amino ester adhesion promoters

Claim 1

An addition-curable composition consisting essentially of, by weight: (A) 100 parts of a vinyl-containing polydiorganosiloxane composition comprising: (1) about 50-100 parts of an essentially cyclic-free vinyl-terminated polydiorganosiloxane having the general formula, R.sub.2 ViSiO(R.sub.2 SiO).sub.m (RViSiO).sub.n SiR.sub.2 Vi, where Vi is a vinyl radical; R is selected from the class consisting of alkyl radicals having 1 to 8 carbon atoms, phenyl radicals, fluoroalkyl radicals having 3 to 10 carbon atoms and mixtures thereof and the value of m+n is sufficient to provide a viscosity of 100-100,000 centipoise at 25° C. and a vinyl content of about 0.02-2.0& by weight; and (2) about 0-50 parts of a solid, benzene-soluble vinyl-containing resin copolymer comprising (R 1 ) 3 SiO 1/2 units and SiO 4/2 units, where R 1 is a vinyl radical or a monovalent hydrocarbon radical free of aliphatic unsaturation and containing no more than six carbon atoms, the ratio of (R 1 ) 3 SiO 1/2 units to SiO 4/2 units being about 0.5-1.5:1; said copolymer having a vinyl content of about 1.5-3.5% by weight; (B) about 1-20 parts of a hydrogen-containing polysiloxane having an average unit formula, (R.sup.2).sub.a H.sub.b SiO.sub.(4-a-b)/2, where R 2 is a monovalent hydrocarbon radical or halogenated monovalent hydrocarbon radical having about 1-10 carbon atoms and free of aliphatic unsaturation, a has a value of about 0-3, b has a value of about 0-3 and a+b has a value of 0-3; (C) a catalytic amount of a hydrosilylation catalyst, (D) 0.6-2.0 parts, per 100 parts of said addition-curable composition, of a bis(trialkyloxysilyl)alpha-amino ester having the formula (R.sup.3 O).sub.3 SiR.sup.4 OC(O)CH.sub.2 N(H)R.sup.5 Si(OR.sup.3).sub.3, where R 3 is selected from the same or different C 1-4 alkyl radicals and R 4 and R 5 are selected from the same or different C 2-8 alkylene radicals; (E) about 0-200 parts of an extending filler and (F) about 0-50 parts of a reinforcing filler, and in the absence of (A)(2), an amount thereof effective for reinforcement.