Silicone gel composition, cured product thereof, and use therefor

A silicone gel composition, comprising:

• (A) 100 mass parts of an organopolysiloxane having a viscosity at 25° C. of 10 to 10,000 mPa·s, and having an alkenyl group bonded to at least two silicon atoms on average in a molecule;
• (B-1) a branched organohydrogenpolysiloxane having a viscosity at 25° C. of 2 to 1,000 mPa·s, having three or more silicon atom-bonded hydrogen atoms in a molecule, and containing at least 20 mol % or more of siloxane units expressed by SiO4/2, present in an amount at which hydrogen atoms bonded to a silicon atom is 0.1 to 0.8 per alkenyl group bonded to a silicon atom in the entire composition;
• (B-2) a chain organohydrogenpolysiloxane having a viscosity at 25° C. of 2 to 1,000 mPa·s, and having two silicon-bonded hydrogen atoms in one molecule, present in an amount at which hydrogen atoms bonded to a silicon atom is 0 to 0.9 per alkenyl group bonded to a silicon atom in the entire composition;
• (C) a platinum-based addition reaction catalyst, present in an amount at which the amount of platinum-based metal is 0.01 to 1,000 ppm with respect to the entire composition;
• and
• (D) 0.2 to 10.0 mass parts of a reaction product of (d1) alkali metal silanolate and (d2) one or more types of ceric salts selected from cerium chloride and carboxylates of cerium;
• wherein the amount is such that the total number of hydrogen atoms bonded to a silicon atom of component (B-1) and component (B-2) is 0.7 to 1.2 per alkenyl group bonded to a silicon atom in the entire composition;
• wherein component (A) is one or a mixture of the following:
• (A-1) a branched organopolysiloxane having an alkenyl group bonded to at least two silicon atoms in a molecule;
• and
• (A-2) a linear organopolysiloxane having a viscosity at 25° C. of 1.0 to 10,000 mPa·s, and having an alkenyl group bonded to at least two silicon atoms in a molecule;
• and
• wherein component (B-2) is a linear organohydrogenpolysiloxane having silicon-bonded hydrogen atoms only at both molecular chain terminals, and having a viscosity at 25° C. within a range of 2 to 200 mPa·s;
• and
• wherein component (A) comprises component (A-1), and of all siloxane units configuring the branched organopolysiloxane molecule of component (A-1), 80.0 to 99.8 mol % are R2SiO2/2 units, 0.1 to 10.0 mol % are RSiO3/2 units, and 0.1 to 10.0 mol % are R3SiO1/2 units, where all cases of R represent a monovalent hydrocarbon group bonded to a silicon atom;
• and
• wherein the (B-1) branched organohydrogenpolysiloxane is an MHQ resin.