# US 5,708,054 A · Two-part curable liquid silicone composition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,708,054 A - Document ID: US5708054A - Status: Granted - Kind: A - Application number: 08/738,486 - Filed: 1996-10-28 - Granted: 1998-01-13 - Earliest claimed: 1995-11-08 - Assignees: Dow Corning Toray Silicone Co., Ltd. - Inventors: Katsutoshi Mine; Takae Takeuchi; Kimio Yamakawa - Web page: https://patentgrep.com/patent/US5708054A ## CPC - C08L 83/04: Polysiloxanes - C08G 77/12: containing silicon bound to hydrogen - C08G 77/18: to alkoxy or aryloxy groups - C08G 77/20: containing silicon bound to unsaturated aliphatic groups - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS ## Abstract A two-part composition comprising a liquid composition (I) composed of the components (A), (C), and (E) described below and a liquid composition (II) composed of the components (A) (B), (C), and (D) described below, which yield upon mixing a curable liquid silicone composition comprising (A) an alkenyl-substituted poyorganopolysiloxane; (B) a hydrogen-substituted organopolysiloxane in an amount that provides 0.3 to 10 moles silicon-bonded hydrogen from component (B) per 1 mole alkenyl in component (A); (C) an inorganic filler that has a specific surface of 50 to 500 m.sup.2 /g; (D) an alkoxy-substituted organopolysiloxane; and (E) platinum catalyst in a quantity sufficient to cure the instant composition; wherein the curable silicone composition that results when liquid composition (I) and liquid composition (II) are mixed, is thixotropic and has a viscosity, immediately upon the mixing that is greater than the viscosity of liquid composition (II). ## Claims ### Claim 1 A two-part curable liquid silicone composition comprising a first liquid composition (I) comprising components (A), (C), and (E) described below and a second liquid composition (II) comprising components (A) (B), (C), and (D) described below, which yields upon mixing a curable liquid silicone composition consisting essentially of (A) 100 parts by weight of an alkenyl-substituted polyorganopolysiloxane having a viscosity at 25.degree. C. of 10 to 1,000,000 centipoise and containing at least 2 alkenyl groups in each molecule; (B) a hydrogen-substituted organopolysiloxane having a viscosity at 25.degree. C. of 1 to 10,000 centipoise and containing at least 2 silicon-bonded hydrogen atoms in each molecule, in an amount that provides 0.3 to 10 moles silicon-bonded hydrogen from component (B) per 1 mole alkenyl in component (A); (C) 2 to 50 parts by weight of an inorganic filler that has a specific surface of 50 to 500 m.sup.2 /g; (D) 0.1 to 20 parts by weight of an alkoxy-substituted organopolysiloxane having a viscosity at 25.degree. C. of 1 to 2,000 centipoise and containing at least 2 silicon-bonded alkoxy groups in each molecule; and (E) platinum catalyst in a quantity sufficient to cure the curable liquid silicone composition; wherein the curable silicone composition that results when the first liquid composition (I) and the second liquid composition (II) are mixed, is thiotropic and has a viscosity, immediately upon mixing that is greater than the viscosity of the first liquid composition (I) and is greater than the viscosity of the second liquid composition (II). ### Claim 2 (depends on 1) The two-part composition of claim 1 wherein the alkenyl groups of component (A) are vinyl. ### Claim 3 (depends on 1) The two-part composition of claim 1 wherein the viscosity of the curable silicone composition that results when the first liquid composition (I) and the second liquid composition (II) are mixed is 1.3 to 30 times greater than the viscosity of the greater of the viscosities of the first liquid composition (I) or the second liquid composition (ii). ### Claim 4 (depends on 1) The two-part composition of claim 1 wherein component (A) has a substantially straight-chain structure. ### Claim 5 (depends on 1) The two-part composition of claim 1 wherein component (B) has a substantially straight-chain structure. ### Claim 6 (depends on 1) The two-part composition of claim 1 wherein the viscosity of the curable silicone composition that results when the first liquid composition (I) and the second liquid composition (II) are mixed is 1.5 to 20 times greater than the viscosity of the greater of the viscosities of the first liquid composition (I) or the second liquid composition (ii). ### Claim 7 (depends on 1) The two-part composition of claim 1 wherein component (C) is silica. ### Claim 8 (depends on 7) The two-part composition of claim 7 wherein component (C) is fumed silica. ### Claim 9 (depends on 1) The two-part composition of claim 1 wherein the component (C) has been treated with a surface treatment agent. ### Claim 10 (depends on 9) The two-part composition of claim 9 wherein the surface treatment agent is an organoalkoxysilane, an organochlorosilane, a silazane or an organosiloxane oligomer. ### Claim 11 (depends on 1) The two-part composition of claim 1 wherein the silicon-bonded alkoxy groups of component (D) are methoxy. ### Claim 12 A two-part curable liquid silicone composition comprising a first liquid composition (I) comprising components (A), (C), and (E) described below and a second liquid composition (II) comprising components (A) (B), (C), and (D) described below, which yields upon mixing a curable liquid silicone composition comprising (A) 100 parts by weight of an alkenyl-substituted polyorganopolysiloxane having a viscosity at 25.degree. C. of 10 to 1,000,000 centipoise and containing at least 2 alkenyl groups in each molecule; (B) a hydrogen-substituted organopolysiloxane having a viscosity at 25.degree. C. of 1 to 10,000 centipoise and containing at least 2 silicon-bonded hydrogen atoms in each molecule, in an amount that provides 0.3 to 10 moles silicon-bonded hydrogen from component (B) per 1 mole alkenyl in component (A); (C) 2 to 50 parts by weight of an inorganic filler that has a specific surface area of 50 to 500 m.sup.2 /g; (D) 0.1 to 20 parts by weight of an alkoxy-substituted organopolysiloxane having a viscosity at 25.degree. C. of 1 to 2,000 centipoise and containing at least 2 silicon-bonded alkoxy groups in each molecule; and (E) platinum catalyst in a quantity sufficient to cure the curable liquid silicone composition; wherein the curable silicone composition that results when the first liquid composition (I) and the second liquid composition (II) are mixed, is thixotropic and has a viscosity, immediately upon mixing that is greater than the viscosity of the first liquid composition (I) and is greater than the viscosity of the second liquid composition (II); and wherein component (D) is a compound having the formula ##STR12## a compound having the formula ##STR13## a compound having the formula ##STR14## a compound having the formula ##STR15## or a compound having the formula ##STR16## wherein m and n are integers with a value of at least 1.