| 摘要 |
<p>A gel composition that is of comparatively low viscosity, exhibits favorable flowability, and generates a gel cured product that is capable of withstanding large displacements. The invention provides a silicone gel composition comprising:
(A) an organopolysiloxane represented by an average composition formula (1) shown below:
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ R a R 1 b SiO (4-a-b)/2 €ƒ€ƒ€ƒ€ƒ€ƒ(1)
(wherein, R represents an alkenyl group, R 1 represents a monovalent hydrocarbon group that contains no aliphatic unsaturated bonds, and a, b and a+b are numbers that satisfy specific numerical ranges), and containing at least one alkenyl group bonded to a silicon atom within each molecule,
(B) a component composed of:
(B-1) an organohydrogenpolysiloxane represented by an average composition formula (2) shown below:
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ (HR 2 2 SiO 1/2 ) c (R 3 2 SiO) d (R 4 SiO 3/2 ) e €ƒ€ƒ€ƒ€ƒ€ƒ(2)
(wherein, R 2 , R 3 and R 4 represent monovalent hydrocarbon groups that contain no aliphatic unsaturated bonds, and c, d and e are numbers that satisfy specific numerical ranges, provided that c+d+e = 1), containing at least three hydrogen atoms bonded to silicon atoms within each molecule, and containing at least two (R 4 SiO 3/2 ) units within each molecule, and
(B-2) an organohydrogenpolysiloxane represented by an average composition formula (3) shown below:
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ R 5 f H g SiO (4-f-g)/2 €ƒ€ƒ€ƒ€ƒ€ƒ(3)
(wherein, R 5 represents a monovalent hydrocarbon group that contains no aliphatic unsaturated bonds, and f, g and f+g are numbers that satisfy specific numerical ranges), containing either one or two hydrogen atoms bonded to silicon atoms within each molecule, and containing either one or two hydrogen atoms bonded to silicon atoms at molecular chain terminals,
in which the number ± of hydrogen atoms bonded to silicon atoms derived from component (B-1) and the number ² of hydrogen atoms bonded to silicon atoms derived from component (B-2) satisfy a formula (4) shown below:
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ 0 ‰¤ ²/(±+²) ‰¤ 0.75€ƒ€ƒ€ƒ€ƒ€ƒ(4)
and the combined total of hydrogen atoms bonded to silicon atoms within component (B) per alkenyl group bonded to a silicon atom within component (A) is within a range from 0.1 to 5, and
(C) an effective quantity of a platinum-based catalyst, as well as a cured product having a penetration value prescribed in JIS K-2207 of 10 to 200, obtained by curing the silicone gel composition.</p> |
