One-part curable organosiloxane composition

In a curable organosiloxane composition consisting essentially of:

• (A) an organopolysiloxane containing at least 2 silicon-bonded alkenyl radicals in each molecule and represented by the average formula R.sub.a SiO.sub.(4-a)/2, where R represents a substituted or unsubstituted monovalent hydrocarbon radical and a represents an umber with a value of from 1.8 to 2.3, inclusive,
• (B) an organohydrogenpolysiloxane containing at least 2 silicon-bonded hydrogen atoms in each molecule, and
• (C) a particulate material exhibiting an average particle size of from 0.01 to 500 micrometers and consisting essentially of a hydrosilylation catalyst and a resin selected from the group consisting of silicone resins and polysilane resins, where said resins exhibit a softening point or glass transition temperature of from 40 to 200 degrees Centigrade and prevent contact between said catalyst and the other ingredients of said composition,
• the improvement comprising the presence in said composition of
• (D) an additive selected from the group consisting of the carboxylates, silanolates and beta-diketonates of metallic elements exclusive of those in groups IA and IIA of the Periodic Table, where the concentration of said additive is equivalent to from 0.0005 to 0.1 weight parts of the metallic element per 100 parts of said organopolysiloxane.