Low-viscosity pressure-adherent silicone elastomer compositions

Claim 2

A pressure-adherent silicone elastomer composition comprising a homogeneous mixture of: (1) a silicone pressure sensitive adhesive composition employed in an amount from about 15 to about 90 parts by weight, said silicone pressure sensitive adhesive composition comprising a homogeneous mixture of (A) from about 35 to about 70 parts by weight of at least one benzene-soluble resinous copolymer containing silicon-bonded hydroxyl radicals and consisting essentially of triorganosiloxy units of the formula R₃SiO 1/2 and tetrafunctionalsiloxy units of the formula SiO 4/2 in a ratio of about 0.6 to 0.9 triorganosiloxy units for each tetra­functionalsiloxy unit present in the copolymer, and (B) from about 30 to about 65 parts by weight of at least one polydiorganosiloxane consisting essentially of ARSiO units terminated with endblocking TRASiO 1/2 units, each said polydiorganosiloxane having a viscosity of from about 100 centipoise to about 50,000 centipoise at 25°C. where each T is -OH or -OR′, where each R is a monovalent organic radical selected from the group consisting of hydrocarbon radicals of from 1 to 6 inclusive carbon atoms, each R′ is an alkyl radical of from 1 to 4 inclusive carbon atoms and each A radical is selected from the group consisting of R and halohydrocarbon radicals of from 1 to 6 inclusive carbon atoms, said silicone pressure sensitive adhesive composition having been reaction-condensed to a plasticity of not more than about 200 mils at 23°C. as measured after force is applied on a specimen weighing twice the specific gravity of the silicone pressure sensitive adhesive composition for 3 minutes +/- 5 seconds, (II) a crosslinkable silicone elastomer composition employed in an amount from about 10 to about 85 parts by weight, the total of silicone pressure sensitive adhesive composition (I) and cross­linkable silicone elastomer composition (II) being 100 parts by weight, and (III) a non-volatile, nonflammable, compatible viscosity reducing agent for reducing the viscosity of said pressure-adherent silicone elastomer composition employed in an amount from 0 to about 40 weight percent based on the total weight of the silicone pressure sensitive adhesive composition (I) and the crosslinkable silicone elastomer composition (II), said viscosity reducing agent being generally non-reactive with said silicone pressure sensitive adhesive composition (I) and said crosslinkable silicone elastomer composition (II).

Claim 3

A pressure-adherent silicone elastomer composition as claimed in claim 1 further comprising a bioactive agent.

Claim 4

A method of controlling the delivery of a bioactive agent to a substrate, comprising the step of contacting the substrate with a matrix formed from the composition of claim 2.

Claim 5

A method of forming a pressure-adherent silicone elastomer comprising the steps of: a) preparing the pressure-adherent silicone elastomer composition as claimed in claim 1, b) shaping the pressure-adherent silicone elastomer composition in the desired form for curing, and c) curing the pressure-adherent silicone elastomer composition for a sufficient time to form the pressure-adherent silicone elastomer.

Claim 6

A method of controlling the delivery of a bioactive agent to a substrate, comprising the steps of a) contacting the substrate with a membrane formed from the composition as claimed in claim 1, and b) contacting the membrane with a reservoir of the bioactive agent.

Claim 7

A device for delivering a drug to a patient transdermally comprising: a) a container, b) a drug contained within the container, and c) a pressure-adherent silicone elastomer on the container for maintaining contact between the container and the patient's skin comprising the cured material formed from the composition of claim 1.

Claim 8

A kit for making a pressure-adherent silicone elastomer comprising: a first package and a second package, wherein said first package contains a composition comprising a first portion of (I) a silicone pressure sensitive adhesive composition employed in an amount from about 15 to about 90 parts by weight, said silicone pressure sensitive adhesive composition comprising a homogeneous mixture of (A) from about 35 to about 70 parts by weight of at least one benzene-soluble resinous copolymer containing silicon-bonded hydroxyl radicals and consisting essentially of triorganosiloxy units of the formula R₃SiO 1/2 and tetrafunctionalsiloxy units of the formula SiO 4/2 in a ratio of about 0.6 to 0.9 triorganosiloxy units for each tetra­functionalsiloxy unit present in the copolymer, and (B) from about 30 to about 65 parts by weight of at least one polydiorganosiloxane consisting essentially of ARSiO units terminated with endblocking TRASiO 1/2 units, each said polydi­organosiloxane having a viscosity of from about 100 centipoise to about 50,000 centipoise at 25°C. where each T is -OH or -OR′, where each R is a monovalent organic radical selected from the group consisting of hydrocarbon radicals of from 1 to 6 inclusive carbon atoms, each R′ is an alkyl radical of from 1 to 4 inclusive carbon atoms, and each A radical is selected from the group consisting of R and halohydrocarbon radicals of from 1 to 6 inclusive carbon atoms, said silicone pressure sensitive adhesive composition having been reaction-condensed to a plasticity of not more than about 200 mils at 23°C. as measured after force was applied on a specimen weighing twice the specific gravity of the silicone pressure sensitive adhesive composition for 3 minutes +/- 5 seconds, and a catalyst and a first portion of a reactive polydiorganosiloxane, and said second package contains a composition comprising a second portion of said silicone pressure sensitive adhesive composition (I), a crosslinking agent, and a second portion of said reactive polydiorganosiloxane, wherein, after combining the contents of said first and second packages, said reactive polydi­organosiloxane, said catalyst, and said cross­linking agent together make a crosslinkable silicone elastomer composition (II), and, in said parts, said silicone pressure sensitive adhesive composition (I) is employed from about 15 to about 90 parts by weight and said crosslinkable silicone elastomer composition (II) is employed from about 10 to about 85 parts by weight, wherein the total of silicone pressure sensitive adhesive composition (I) and crosslinkable silicone elastomer composition (II) being 100 parts by weight, and wherein said portions may be the same or different and may each be from 0 to 100 percent of the total required amount.

Claim 9

A kit for making a pressure-adherent silicone elastomer comprising: a first package and a second package, wherein said first package contains a composition comprising a first portion of (I) a silicone pressure sensitive adhesive composition employed in an amount from about 15 to about 90 parts by weight, said silicone pressure sensitive adhesive composition comprising a homogeneous mixture of (A) from about 35 to about 70 parts by weight of at least one benzene-soluble resinous copolymer containing silicon-bonded hydroxyl radicals and consisting essentially of triorganosiloxy units of the formula R₃SiO 1/2 and tetrafunctionalsiloxy units of the formula SiO 4/2 in a ratio of about 0.6 to 0.9 triorganosiloxy units for each tetra­functionalsiloxy unit present in the copolymer, and (B) from about 30 to about 65 parts by weight of at least one polydiorganosiloxane consisting essentially of ARSiO units terminated with endblocking TRASiO 1/2 units, each said polydi­organosiloxane having a viscosity of from about 100 centipoise to about 50,000 centipoise at 25°C. where each T is -OH or -OR′, where each R is a monovalent organic radical selected from the group consisting of hydrocarbon radicals of from 1 to 6 inclusive carbon atoms, each R′ is an alkyl radical of from 1 to 4 inclusive carbon atoms, and each A radical is selected from the group consisting of R and halohydrocarbon radicals of from 1 to 6 inclusive carbon atoms, said silicone pressure sensitive adhesive composition having been reaction-condensed to a plasticity of not more than about 200 mils at 23°C. as measured after force was applied on a specimen weighing twice the specific gravity of the silicone pressure sensitive adhesive composition for 3 minutes +/- 5 seconds, and a catalyst and a first portion of a reactive polydiorganosiloxane, and said second package contains a composition comprising a second portion of said silicone pressure sensitive adhesive composition (I), a crosslinking agent, and a second portion of said reactive polydiorganosiloxane, wherein, after combining the contents of said first and second packages, said reactive polydi­organosiloxane, said catalyst, and said cross­linking agent together make a crosslinkable silicone elastomer composition (II), and, in said parts, said silicone pressure sensitive adhesive composition (I) is employed from about 15 to about 90 parts by weight and said crosslinkable silicone elastomer composition (II) is employed from about 10 to about 85 parts by weight, wherein the total of silicone pressure sensitive adhesive composition (I) and crosslinkable silicone elastomer composition (II) being 100 parts by weight, and wherein said portions may be the same or different and may each be from 0 to 100 percent of the total required amount.