abstract |
A fast curing, addition-curable silicone composition curable to form an adhesive having good physical properties and improved lap shear adhesive properties, comprising (A) a vinyl-containing polydiorganosiloxane composition, (B) a hydrogen-terminated polysiloxane in an amount sufficient to provide an adhesion-promoting molar ratio of silicon-bonded hydrogen atoms in (B) to olefinically unsaturated radicals in (A); (C) a catalytic amount of a platinum-containing hydrosilation catalyst; (D) an effective amount of an adhesion promoter selected from the group consisting of (i) bis[3-(trimethoxysilyl)alkyl]fumarates; (ii) bis[3-(trimethoxysilyl)alkyl]maleates; (iii) allyl-[3-(trimethoxysilyl)alkyl]maleates; (iv) allyl-[3-(trimethoxysilyl)alkyl]fumarates; and (v) N-[3-(trimethoxysilyl)alkyl]maleimides, wherein R 2 , R 3 , and R 4 are each alkyl radicals of 1 to about 8 carbon atoms; and (E) from about 0 to about 200 parts of an extending filler; and (F) from about 0 to about 50 parts of a reinforcing filler; providing that (F) must be present if (A)(ii) is absent. |