| 摘要 |
A liquid silicone rubber composition comprising an alkenyl group-containing liquid organopolysiloxane, a reinforcing silica filler, an organohydrogenpolysiloxane, a platinum group catalyst, a liquid organopolysiloxane that is free of crosslinking groups and is compatible with the alkenyl group-containing liquid organopolysiloxane, and a liquid organopolysiloxane that is free of crosslinking groups and is incompatible with the alkenyl group-containing liquid organopolysiloxane, wherein the cured material therefrom has a JIS type A durometer hardness of 15 to 26 and a tensile stress at 100% elongation of 0.25 to 0.60 MPa. Also, a through hole-containing sealing member comprising this cured material. |
| 主权项 |
1. A curable liquid silicone rubber composition for forming a through hole-containing sealing member, the composition comprising:
(A) 100 weight parts of a liquid organopolysiloxane that is represented by the average unit formula: RaSiO(4-a)/2 wherein R is an unsubstituted monovalent hydrocarbyl group or a halogenated monovalent hydrocarbyl group and a is 1.95 to 2.05, that contains at least two silicon-bonded alkenyl groups in each molecule, and that has a viscosity at 25° C. of 100 to 100,000 mPa·s; (B) 10 to 100 weight parts of a reinforcing silica filler; (C) an organohydrogenpolysiloxane that has at least two hydrosilyl groups in each molecule, in an amount that provides (1.0:1) to (3.0:1) for the ratio between the number of moles of hydrosilyl groups in this component and the number of moles of alkenyl groups in component (A); (D) a platinum group catalyst, in a catalytic amount; (E) a liquid organopolysiloxane that does not contain an aliphatically unsaturated group, hydrosilyl group, and silanol group, that has a viscosity at 25° C. of 10 to 500,000 mPa·s, and that is compatible with component (A), in an amount that is 15 to 31 weight % of the total of components (A) to (F); and (F) a liquid organopolysiloxane that does not contain an aliphatically unsaturated group, hydrosilyl group, and silanol group, that has a viscosity at 25° C. of 10 to 500,000 mPa·s, and that is incompatible with component (A), in an amount that is 1.0 to 10 weight % of the total of components (A) to (F), wherein the cured material therefrom has a hardness, measured using a type A durometer according to JIS K 6253, “Hardness Test Method for Vulcanized Rubbers”, of 15 to 26 and has a tensile stress at 100% elongation, measured according to JIS K 6251, “Vulcanized Rubbers and Thermoplastic Rubbers—Determination of Tensile Properties”, of 0.25 to 0.60 MPa. |
