Silicone resin molding compositions

Claim 1

A silicone resin molding composition comprising essentially (a) an ester-modified organopolysiloxane resin which is produced by modifying an organopolysiloxane resin containing substituted or unsubstituted silicon-bonded organic monovalent hydrocarbon groups, the ratio of the organic groups to silicon atoms being from 1:1 to 1.6:1, and hydroxy groups bonded to silicon atoms in an amount larger than 0.25% by weight, with at least one ester having molecular weight exceeding 300 and produced by the condensation reaction of an aliphatic alcohol and an organocarboxylic acid, said ester-modified organopolysiloxane resin being produced by heating the mixture of 100 parts by weight of said organopolysiloxane resin and from 3 to 30 parts by weight of said ester at an elevated temperature, (b) an inorganic filler selected from the group consisting of glass powder, asbestos, wollastonite, diatomaceous earth, euartz powder, clay, fumed silica, precipitated silica, zirconium silicate, magnesium silicate, lithium silicate, and aluminum silicate, and (c) a curing catalyst wherein said curing catalyst is selected from the group consisting of inorganic and organic salt of lead, cobalt and manganese and mixtures thereof with polyols, organic carboxylic acids, ammonium carboxylates or carboxylic acid anhydrides.