Molding process using room temperature curing silicone coatings to provide multiple release of articles

Claim 1

In a method for molding articles comprising placing a molding composition in a mold, converting the molding composition to a solid molded article and thereafter separating the solid molded article from the mold, the improvement comprising applying a silicone mold release composition to at least one shape-determining surface of the mold, and thereafter curing the silicone mold release composition before the molding composition is placed in contact therewith, wherein the silicone mold release composition is stable if stored in containers that exclude moisture, cures when exposed to moisture, and is obtained by mixing components consisting essentially of (I) a polydimethylsiloxane represented by the general formula Y[(CH.sub.3).sub.2 SiO].sub.k H in which Y is a methyl or hydroxyl radical with the stipulation that at least 80 percent of Y are hydroxyl radicals and k has an average value greater than 20; (II) an alkoxysilane represented by the general formula (RO).sub.n SiR'.sub.4-n wherein R is a methyl, ethyl, propyl or methoxyethyl radical, R' is a monovalent hydrocarbon radical or halogenated hydrocarbon radical having 1 to 4 carbon atoms, and n has a value of 3 or 4; (III) a metal alkoxide selected from the group consisting of tetraalkyltitanates, tetraalkylgermanates, tetraalkylzirconates and vanadium trialkoxide oxides; and (IV) a non-reactive, volatile organic solvent which is substantially water free, the components being mixed in amounts of 25 to 98 parts by weight of (I), 1.5 to 65 parts by weight of (II), and 0.3 to 18 parts by weight of (III) for every 100 parts by weight of (I) plus (II) plus (III).