Ultraviolet radiation-curable silicone composition, cured product thereof, layered body, optical device, and optical display

A UV-curable silicone composition, comprising:

• (A) one or more chain-like organopolysiloxane selected from the following component (A1) and component (A2);
• (A1) linear organopolysiloxanes expressed by the following structural formula (I-1) having a methacryloyl group-containing organic group expressed by the following formula (II-1) or (II-2) in a molecule
• structural formula (I-1):
• where R1 independently represents a C1-C6 alkyl group, a C2-C20 alkenyl group, or a C6-C12 aryl group, RA independently represents a C1-C6 alkyl group, a C2-C20 alkenyl group, a C6-C12 aryl group, or a methacryloyl group-containing organic group expressed by formula (II-1) or formula (II-2):
• where m represents a positive number of 1 or more, Z1 represents —O(CH2)a—, where a represents a number in a range of 0 to 3, and Z2 represents a divalent organic group expressed by —(CH2)b—, where b represents a number in a range of 2 to 10, bonded to a silicon atom configuring a main chain of a polysiloxane represented by *
• where Z2 represents the same divalent organic group as above, RA′ represents a methacryloyl group-containing organic group expressed by formula (II-1) or formula (II-2) where the value of m+a+b in formula (II-1) is 6 or more or b in formula (II-2) is a number in a range of 6 to 10, which is bonded to a main chain of a polysiloxane via a linking group of a certain chain length or longer, n1 represents a positive number, and n2 represents 0 or a positive number;
• provided however if n2 is 0, at least one of RA represents a methacryloyl group-containing organic group expressed by formula (II-1) or formula (II-2), and
• (A2) branched organopolysiloxanes expressed by the following average unit formula (I-2) having a methacryloyl group-containing organic group expressed by formula (II-1) or (II-2) in a molecule and containing a branched siloxane unit average unit formula (I-2):
• (RAR12SiO1/2)x(R12SiO2/2)y1(RA′R1SiO2/2)y2(R1SiO3/2)z1(RA′SiO3/2)z2 (I-2)
• where R1, RA, and RA′ are the same groups as above, x, y1, y2, z1, and z2 all satisfy the following conditions of (x+y1+y2+z1+z2)=1, 0<x≤0.2, 0.3≤(y1+y2)<1, 0<(z1+z2)≤0.2, and (y2+z2)=0, and at least one RA represents a methacryloyl group-containing organic group expressed by formula (II-1) or formula (II-2);
• (B) a monofunctional or polyfunctional acrylate compound;
• and
• (C) a photopolymerization initiator;
• wherein the ratio [(a)/(b)] of (a) the number of mols of methacroyl groups derived from component (A) to (b) the number of mols of acryloyl groups derived from component (B) in the composition is in a range of 0.1 to 3.0.