Solventless silicone controlled release compositions

Claim 2

A controlled release additive comprising a copolymer of R 3 SiO ½ units and SiO 4/2 units, where R represents the same or different monovalent hydrocarbon radical of no more than 2 carbon atoms, dispersed in an unsaturated non-volatile organic reactive diluent.

Claim 3

The controlled release additive of Claim 1, wherein said copolymer is an uncondensed silicone MQ resin and said reactive diluent is selected from the group consisting of dibutyl maleate, decylvinylether, dodecylvinylether, camphene, C (16-18) alpha-olefin and meta-bis-isopropenylbenzene:

Claim 4

The controlled release additive of Claim 1, wherein said copolymer is a vinyl silicone MQ resin and said reactive diluent is a C (16-18) alpha-olefin mixture.

Claim 5

The controlled release additive of Claim 1 which also contains a small amount of a vinyl-containing polysiloxane gum.

Claim 6

A solventless silicone controlled release composition comprising: (1) a diorganopolysiloxane base polymer having up to 20% by weight of SiH groups or silanol-functional groups and a viscosity of from about 50 to about 100,000 centipoise at 25°C; (2) a copolymer of R 3 SiO ½ and SiO 4/2 units, where R is the same or different monovalent hydrocarbon radical of no more than 2 carbon atoms dispersed in an unsaturated organic reactive diluent; (3) a polymethylhydrogen siloxane fluid crosslinking agent having up to about 100 parts by weight SiH groups and a viscosity of about 25 to 1,000 centipoise at 25°C; (4) an effective amount of a precious metal catalyst for promoting an addition cured hydrosilation reaction between said copolymer, said additive and said crosslinking agent; and (5) an amount of dialkyl carboxylic ester containing carbon-to-carbon unsaturation effective to exhibit said hydrosilation reaction at temperatures below the heat cure temperature of said silicone controlled release composition.

Claim 7

A solventless silicone controlled release composition comprising: (1) a diorganopolysiloxane base polymer having up to 20% by weight of SiH groups or silanol-functional groups and a viscosity of from about 50 to about 100,000 centipoise at 25°C; (2) a copolymer of R 3 SiO ½ and SiO 4/2 units, where R is the same or different monovalent hydrocarbon radical of no more than 2 carbon atoms dispersed in an unsaturated organic reactive diluent; (3) a polymethylhydrogen siloxane fluid crosslinking agent having up to about 100 parts by weight SiH groups and a viscosity of about 25 to 1,000 centipoise at 25°C; (4) an effective amount of a precious metal catalyst for promoting an addition cured hydrosilation reaction between said copolymer, said additive and said crosslinking agent; and (5) an amount of dialkyl carboxylic ester containing carbon-to-carbon unsaturation effective to exhibit said hydrosilation reaction at temperatures below the heat cure temperature of said silicone controlled release composition.

Claim 8

The composition of Claim 5, wherein said base polymer is a vinyl-chainstopped polydimethylmethylvinylsiloxane copolymer.

Claim 9

The composition of Claim 5, wherein said copolymer component (2) is an uncondensed silicone MQ resin and said reactive diluent is selected from the group consisting of dibutyl maleate, decylvinylether, dodecylvinylether, camphene, C (16-18) alpha-olefin and meta-bis-isopropenylbenzene.

Claim 10

The composition of Claim 5, wherein said copolymer component (2) is a vinyl silicone MQ resin dispersed in C (16-18) alpha-olefin.

Claim 11

The composition of Claim 5 which also contains a small amount of a vinyl-containing polysiloxane gum.

Claim 12

The composition of Claim 5, wherein the base polymer is silanol-functional and was prepared by a KOH-catalyzed equilibration of octamethylcyclotetrasiloxane and water, neutralized by the addition of a small amount of tris(2-chloroethyl) p hosphite.

Claim 13

A silanol-functional diorganopolysiloxane composition free of latent condensation catalyst having up to about 20% by weight SiOH groups and a viscosity of from about 50 to about 100,000 centipoise at 25°C prepared by a base-catalyzed equilibration of cyclic polysiloxane monomers and water, said base being neutralized by the addition of tris(2-chloroethyl)phosphite.

Claim 14

A silanol-functional diorganopolysiloxane composition free of latent condensation catalyst having up to about 20% by weight SiOH groups and a viscosity of from about 50 to about 100,000 centipoise at 25°C prepared by a base-catalyzed equilibration of cyclic polysiloxane monomers and water, said base being neutralized by the addition of tris(2-chloroethyl)phosphite.

Claim 15

A silanol-functional diorganopolysiloxane composition as defined in Claim 11, wherein said base is KOH and said cyclic polysiloxane monomers are primarily octamethylcyclotetrasiloxane.

Claim 16

A process for preparing a silanol-functional diorganopolysiloxane free of latent condensation catalyst and having up to about 20% by weight SiOH functional groups and a viscosity of from about 50 to about 100,000 centipoise at 25°C comprising (a) equilibrating cyclic polysiloxane monomers and water in the presence of a base and (b) neutralizing the base with tris(2-chloroethyl)phosphite.

Claim 17

A process for preparing a silanol-functional diorganopolysiloxane free of latent condensation catalyst and having up to about 20% by weight SiOH functional groups and a viscosity of from about 50 to about 100,000 centipoise at 25°C comprising (a) equilibrating cyclic polysiloxane monomers and water in the presence of a base and (b) neutralizing the base with tris(2-chloroethyl)phosphite.

Claim 18

The process of Claim 13, wherein said cyclic polysiloxane monomers are primarily octamethylcyclotetrasiloxane and said base is KOH.