Abstract: A release coating composition is prepared comprising a polyorganosiloxane (A) having alkenyl groups, a crosslinking agent (B) having organohydrogensiloxane groups, a catalyst for the hydrosilylation reaction between (A) and (B), and an anchorage additive for enhancing the adhesion of the composition to a polymer film substrate. The anchorage additive is the reaction product of a fluid polyorganosiloxane (C) containing at least one alkenyl group and at least one silanol group with a hydrolysable silane (D) containing at least one epoxide group. The curable silicone release coating composition can be applied to a substrate known as a ‘liner’ retaining a label, which liner can for example be paper or a polymer film, and cured.

Abstract: A release coating composition is prepared comprising a polyorganosiloxane (A) having alkenyl groups, a crosslinking agent (B) having organohydrogensiloxane groups, a catalyst for the hydrosilylation reaction between (A) and (B), and an anchorage additive for enhancing the adhesion of the composition to a polymer film substrate. The anchorage additive is the reaction product of a fluid polyorganosiloxane (C) containing at least one alkenyl group and at least one silanol group with a hydrolysable silane (D) containing at least one epoxide group. The curable silicone release coating composition can be applied to a substrate known as a ‘liner’ retaining a label, which liner can for example be paper or a polymer film, and cured.

Abstract: Novel branched siloxanes, silicone release coating compositions containing the branched siloxanes, and silicone release modifier compositions containing the branched siloxanes comprise compositions having the formula: wherein Ra is an alkyl group having 1-6 carbon atoms, an alkenyl group having 2-6 carbon atoms, or an alkynyl group having 2-6 carbon atoms; Rb is an alkyl group having 1-6 carbon atoms, an alkenyl group having 2-6 carbon atoms, an aryl group, an alkoxy group, an acrylate group, or a methacrylate group; n is 1-200; and provided that at least 3.2-3.9 of the Ra groups in the branched siloxane are alkenyl or alkynyl groups.

Abstract: A release coating composition according to the present invention comprises an alkenyl functional polysiloxane (1), a silicon hydride functional polysiloxane (11) and a catalyst (111) comprising a platinum group metal. The alkenyl functional polysiloxane (1) is an alkenylterminated polysiloxane prepared by siloxane polycondensation and/or equilibration using a phosphazene base catalyst followed by neutralisation with an acidic neutralising agent. The level of catalyst (III) in the composition can be as low as 2-40 parts per million platinum group metal by weight.

Abstract: In a process for release coating of a polymer film with a composition comprising a siloxane (A) having alkenyl groups, a crosslinking agent (B) having organohydrogensiloxane groups and a catalyst for the hydrosilylation reaction between (A) and (B), comprising applying the composition to the polymer film and heating the coated film to cure the release coating, the release coating composition additionally contains a polydiorganosiloxane (C) of viscosity 10200000 mPa·s at 25° C. consisting essentially of diorganosiloxane units of the formula —(SiR2—O)— in which each R group, which may be the same or different, is an alkyl group having 1 to 4 carbon atoms, to improve anchorage of the release coating on the polymer film.

Abstract: A branched siloxane contains at least three aliphatically unsaturated hydrocarbon groups, is terminated by units of the formula RaRb2SiO1/2 and otherwise consists of: i) one or more units of the formula (SiO4/2); and ii) from 15 to 995 units of the formula Rb2SiO2/2 which units (i) and (ii) may be inter-linked in any appropriate combination. The invention includes a method of making the branched siloxane and release coating and release modifier compositions containing the branched siloxane.

Abstract: This invention relates to a macromonomer and a method for its preparation. The macromonomer has silicon-bonded hydrogen atoms at one molecular chain terminal, and aliphatically unsaturated silicon-bonded organic groups at the other molecular chain terminal. This invention further related to a method of forming a hyperbranched polymer by polymerizing the macromonomer with a group VIII metal catalyst. The hyperbranched polymers can be used as surfactants, gelling agents, drug delivery systems, and polymeric absorbents.