Photocurable liquid silicone composition and cured product thereof

A photocurable liquid silicone composition comprising:

• (A) a straight chain organopolysiloxane with a viscosity at 23° C. of 50 to 100,000 mPa·s, containing at least two alkenyl groups with 2 to 12 carbon atoms in a molecule, and not containing a mercaptoalkyl group;
• (B) an organopolysiloxane with a viscosity at 23° C. of 10 to 10,000 mPa·s and having at least two mercaptoalkyl groups in a molecule, in an amount such that the amount of mercaptoalkyl groups in this component is 0.2 to 3 moles with regard to 1 mole of alkenyl groups in component (A);
• (C) a branched chain organopolysiloxane containing siloxane units represented by the formula:
• R3SiO3/2 and/or siloxane units represented by the formula:
• SiO4/2 where R3 represents an alkyl group with 1 to 12 carbon atoms, an aryl group with 6 to 20 carbon atoms, an aralkyl group with 7 to 20 carbon atoms, a hydroxyl group, or an alkoxy group with 1 to 6 carbon atoms,
• wherein the molar ratio of siloxane units represented by the formula:
• R3SiO3/2 and the siloxane units represented by the formula:
• SiO4/2 of all of the siloxane units in component (C) is at least 0.5 and no greater than 0.65, and alkenyl groups and mercaptoalkyl groups are not included;
• (D) a photo radical initiator containing a phosphorus atom;
• and
• (E) a hindered phenol compound;
• wherein the amount of component (C) is 25 to 80 parts by mass, the amount of component (D) is 0.01 to 1.0 parts by mass, and the amount of component (E) is 0.01 to 1.0 parts by mass, with regard to 100 parts by mass of a total of component (A) through component (E).