Photocurable silicone composition and cured product thereof
A photocurable silicone composition is disclosed. A cured product of the composition is also disclosed. The photocurable silicone composition comprises: (A) an organopolysiloxane having at least one aryl group with 6 to 12 carbons and at least one alkenyl group with 2 to 12 carbons in a molecule; (B) an organic compound having at least two ether bonds and at least one aliphatic carbon-carbon double bond in a molecule; (C) a thiol group-containing organic compound comprising; (C 1 ) an organic compound having two thiol groups in a molecule, and (C 2 ) an organic compound having at least three thiol groups in a molecule; and (D) a photoradical initiator. The composition generally suppresses crack and delamination of a cured product laminated between two substrates after thermal aging.
1. A photocurable silicone composition comprising:
(A) 100 parts by mass of an organopolysiloxane having at least one aryl group with 6 to 12 carbons and at least one alkenyl group with 2 to 12 carbons in a molecule;
(B) from 1 to 50 part(s) by mass of an organic compound having at least two ether bonds and at least one aliphatic carbon-carbon double bond in a molecule;
(C) from 4 to 40 parts by mass of a thiol group-containing organic compound comprising;
(C 1 ) an organic compound having two thiol groups in a molecule, and
(C 2 ) an organic compound having at least three thiol groups in a molecule; and
(D) from 0.05 to 2 parts by mass of a photoradical initiator;
wherein a molar ratio of component (C 1 ) to component (C 2 ) in component (C) is in a range of from 0.45 to 2.8.
2. The photocurable silicone composition according to claim 1 , wherein component (A) is an organopolysiloxane represented by the average composition formula:
R 1 a R 2 b SiO (4-a-b)/2
wherein, R 1 is an alkenyl group having from 2 to 12 carbons, R 2 is an alkyl group having from 1 to 12 carbons, an aryl group having from 6 to 12 carbons, or an aralkyl group having from 7 to 12 carbons; provided that, at least 30 mol % of R 2 are the aryl groups or the aralkyl groups; and “a” and “b” are positive numbers satisfying: 1≤a+b≤2.5 and 0.001≤a/(a+b)≤0.2.
3. The photocurable silicone composition according to claim 1 , wherein component (B) is an organic compound having at least two ether bonds and at least one acryloyl group or methacryloyl group in a molecule.
4. The photocurable silicone composition according to claim 1 , wherein component (C) is present in an amount of from 4 to 9.7 parts by mass.
5. The photocurable silicone composition according to claim 1 , wherein component (D) is a photoradical initiator having a phosphorus atom.
6. The photocurable silicone composition according to claim 1 , further comprising:
(E) a hindered phenol compound, in an amount of from 0.001 to 1 part(s) by mass per 100 parts by mass of component (A).
7. The photocurable silicone composition according to claim 1 , further comprising:
(F) a radical scavenger other than component (E), in an amount of from 0.0001 to 1 part(s) by mass per 100 parts by mass of component (A).
8. The photocurable silicone composition according to claim 1 , further comprising:
(G) an adhesion-imparting agent, in an amount of 10 parts by mass or less per 100 parts by mass of component (A).
9. A cured product obtained by irradiating the photocurable silicone composition according to claim 1 with light.
10. The photocurable silicone composition according to claim 6 , further comprising:
(F) a radical scavenger other than component (E), in an amount of from 0.0001 to 1 part(s) by mass per 100 parts by mass of component (A).
11. The photocurable silicone composition according to claim 10 , further comprising:
(G) an adhesion-imparting agent, in an amount of 10 parts by mass or less per 100 parts by mass of component (A).
12. The photocurable silicone composition according to claim 6 , further comprising:
(G) an adhesion-imparting agent, in an amount of 10 parts by mass or less per 100 parts by mass of component (A).
13. The photocurable silicone composition according to claim 1 , wherein a molar ratio of thiol groups in component (C) per 1 mole of aliphatic saturated carbon-carbon double bonds in components (A) and (B) ranges from 0.7 to 0.9.