Dow Corning Corporation

Sarah Louise O'Hare

Iain A Mackinnon

Geraldine Durand

Peter Cheshire Hupfield

Richard G Taylor

Robert A Ekeland

Stephen E Cray

Francois De Buyl

Leon Neal Cook

Marc Thibaut

David A Rich

Jean De La Cro Habimana

David Eglin

Helen L Gough

Sue Strange

Ian Mackinnon

David Rich

Stephen Edward Cray

Robert Alan Ekeland

A polyorganosiloxane polyoxyalkylene block copolymer having one or more polyorganosiloxane blocks and one or more polyoxyalkylene blocks linked to each other via divalent radicals which comprises at least two silicon-bonded alkoxy groups, preferably of the form PS (A PO)(A PS), wherein PO is a polyoxyalkylene block, PS represents a polyorganosiloxane block, A is a divalent radical, m and n have independently a value of at least 1, comprising at least one alkoxy-substituted siloxane unit of the formula (R')(OR)&#x2014;SiO, wherein R represents an alkyl group having 1 to 4 carbon atoms and each R&#x2032; represents an alkyl group having 1 to 6 carbon atoms, a phenyl group, or an alkoxy group of the formula &#x2014;OR and q has a value of 0, 1 or 2, provided at least two silicon-bonded groups OR are present in the block copolymer. Also provided is a curable composition of the above which may comprise a condensation catalyst and a hydrophilic polymer network made from curing the composition in the presence of moisture, which exhibit interesting reversible hydrophilic properties.

Polymer and polymer compositions

The invention relates to a water-insoluble hydrophilic polymer network comprising polyorganosiloxane polyoxyalkylene block copolymer moieties characterized that they are linked to each other through an organosilicon cross-linking moiety, provided that the cross-linking moiety forming the links between polyorganosiloxane polyoxyalkylene block copolymer moieties result from an addition reaction between cross-linking sites present on the polyorganosiloxane polyoxyalkylene block copolymer moieties prior to formation of the hydrophilic polymer network, selected from silicon-bonded hydrogen atoms and aliphatically unsaturated groups, and reactive groups present on the cross-linking moiety prior to formation of the hydrophilic polymer network. Also disclosed is a process for making the polymer network, and a curable composition able to be reacted into such polymer network.

Polymer compositions

A process for stabilising the viscosity of an amino-functional siloxane polymer comprises adding a dialkoxydialkylsilane to the amino-functional siloxane polymer or to the reagents from which the amino-functional siloxane polymer is produced.

Process of stabilising siloxane polymers

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.

Silicone release coating compositions

Phosphonitrile halides are prepared employing the use of disilazanes. The resultant products may be further reacted with cyclosiloxanes to form siloxane containing phosphonitrile halides.

Method for making a catalyst composition

Growing community of inventors

Dinas Powys, United Kingdom

Sarah Louise O'Hare