US 8,273,842 B2 · Process for production of cyclic polyorganosiloxane, curing agent, curable composition, and cured product of the curable composition

Abstract

An object of the invention is to provide a curing agent and a curable composition capable of forming a cured product, which is applicable for optical material and which has excellent heat and light transparency and crack resistance, and a cured product obtained by curing the same. Moreover, an object of the invention is to provide a method for producing with use of the components of the curing agent a cyclic polyorganosiloxane having a specific structure, in a selective manner and in high yield. In order to attain the objects, a curable composition including, as essential components, (A) an organic compound including at least two carbon-carbon double bonds that are reactive with a SiH group, (B) a compound having at least two SiH groups per molecule, and (C) a hydrosilylation catalyst, uses a modified polyorganosiloxane compound having at least two SiH groups per molecule as the compound having at least two SiH groups, which modified polyorganosiloxane compound is a reaction product of a specific cyclic polyorganosiloxane.

Claims28

Dependent claims

A method for producing a cyclic polyorganosiloxane comprising:

decomposing a polyorganosiloxane by heating the polyorganosiloxane in the presence of a catalyst, the polyorganosiloxane having a main chain skeleton represented by the following general formula (I):
wherein R1 to R3 are identical or different monovalent substituted or unsubstituted hydrocarbon groups;
and m and n satisfy:
0.3≦n/(m+n)<0.9.

1 more element

A curable composition comprising:

(A) an organic compound having at least two carbon-carbon double bonds per molecule, the carbon-carbon double bond being reactive with a SiH group;
(B) a modified polyorganosiloxane compound;
and
(C) a hydrosilylation catalyst, wherein:
the (B) modified polyorganosiloxane compound having at least two SiH groups per molecule and being a hydrosilylation reaction product of the following compounds (α) and (β):
(α) an organic compound having two to six carbon-carbon double bonds per molecule, the carbon-carbon double bonds being reactive with an SiH group, and
(β) a cyclic polyorganosiloxane comprising the following general formula (IV):
wherein R1 to R3 are identical or different monovalent substituted or unsubstituted hydrocarbon groups;
p is an integer of 1 to 8, q is an integer of 2 to 6, p and q being integers that satisfy:
3≦p+q≦10;
the cyclic polyorganosiloxane produced by a method comprising:
decomposing a polyorganosiloxane by heating the polyorganosiloxane in the presence of a catalyst, the polyorganosiloxane having a main chain skeleton represented by the following general formula (I):
wherein R1 to R3 are identical or different monovalent substituted or unsubstituted hydrocarbon groups;
m and n satisfy:
0.3≦n/(m+n)<0.9.

12 more elements

Dependencies are inferred from the claim text.

Process for production of cyclic polyorganosiloxane, curing agent, curable composition, and cured product of the curable composition

Life of this patent

Process for production of cyclic polyorganosiloxane, curing agent, curable composition, and cured product of the curable composition

Life of this patent

Abstract

Claims28