Abstract: The present invention is a process for the preparation of organofunctional-terminated polydiorganosiloxane polymers and organofunctional polydiorganosiloxane copolymers. The process comprises reacting a chlorine-terminated polydiorganosiloxane polymer with: (1) an organofunctional chlorosilane end-blocker to form an organofunctional terminated polydiorganosiloxane polymer and (2) a mixture of organochlorosilane end-blocker and organofunctional dichlorosilane to form an organofunctional polydiorganosiloxane copolymer. The process is conducted in the presence of an aqueous solution of hydrogen chloride, where the water is present in stoichiometric excess in relation to the hydrolyzable silicon-bonded chlorine.The present process is particularly useful for producing 5-hexenyl-terminated polydimethylsiloxane polymers and for producing siloxane copolymers comprising randomly distributed poly-5-hexenylmethylsiloxy and polydimethylsiloxy blocks.

Abstract: The described process uses aqueous hydrogen chloride as a catalyst to effect the condensation of chloride and hydroxy end-substituted polyorganosiloxanes, in the presence of triorganosilyl endblocker to control chain length. The inventors have discovered that within a range of about 10 to 30 percent aqueous solution of hydrogen chloride, it is possible to produce polyorganosiloxanes with low levels of chloride and hydroxy substitution. Furthermore, it has been found that within this hydrogen chloride range, temperature and hydrogen chloride concentration can be controlled to produce polyorganosiloxane polymers with a reproducible and predictable level of hydroxy substitution.

Abstract: The described process uses a Lewis base as a catalyst to effect the condensation of hydroxy end-substituted polyorganosiloxanes, in the presence of triorganosilyl endblocker to control polymer chain length. The inventors have discovered that within a base catalyst concentration range where the cation concentration is about 1.times.10.sup.-3 to 2.times.10.sup.-1 mole percent in relation to the silicon atoms present, the partial pressure of water can be controlled at a constant value to produce polyorganosiloxane polymers with a reproducible and predictable level of hydroxy substitution.

Abstract: A new organohydrogenpolysiloxane compound and a new fluorosilicone polymer each have unique properties which allow for the preparation of faster curing coating compositions having longer bath life than those disclosed in the art. In a preferred embodiment the new polymers are mixed together to provide, along with a metal-containing hydrosilylation catalyst and a catalyst inhibitor to provide improved coating compositions which are useful for preparing a release linear to protect silicone pressure sensitive adhesives.

Abstract: A new organohydrogenpolysiloxane compound and a new fluorosilicone polymer each have unique properties which allow for the preparation of faster curing coating compositions having longer bath life than those disclosed in the art. In a preferred embodiment the new polymers are mixed together to provide, along with a metal-containing hydrosilylation catalyst and a catalyst inhibitor to provide improved coating compositions which are useful for preparing a release liner to protect silicone pressure sensitive adhesives.

Abstract: A process for preparing a product cyclopolydiorganosiloxane, (R.sub.2 SiO).sub.c. The process comprises (A) vaporizing a feed cyclopolydiorganosiloxane material, (R.sub.2 SiO).sub.x ; (B) passing the vapors from (A) through a heated bed of a solid catalyst, the catalyst comprising an alkali metal compound; (C) controlling pressure and temperature in the heated catalyst bed to favor formation of (R.sub.2 SiO).sub.c in an equilibrating mixture with other cyclopolydiorganosiloxanes; and (D) recovering an amount of the product cyclopolydiorganosiloxane, (R.sub.2 SiO).sub.c, which is substantially increased from the amount present in the feed cyclopolydiorganosiloxane material.