Curable composition and cured article excellent in transparency
View Patent ↗An object of the invention is to yield a highly transparent cured article wherein bubbles are less generated when a catalyst and others are added to a curable composition that contains an organic polymer having a silicon-containing group which can be crosslinked by the formation of a siloxane bond and then the resultant mixture is stirred. Another object thereof is to provide a cured article which is small in surface stickiness, slightly gets dirty over a long term, and has a practical adhesiveness. These objects are attained by a curable composition which comprises (A) an organic polymer having a silicon-containing group that can be crosslinked by the formation of a siloxane bond, (B) a bivalent tin carboxylate and (C) an amine compound having no reactive silicon group, and which turns transparent when cured; or a transparent cured article obtained by curing the composition.
1. A moisture curable composition comprising:
(A) an organic polymer having reactive silicon group(s), wherein the organic polymer is a mixture composed of a polyoxypropylene polymer having a reactive silicon group, and a (meth)acrylic acid ester polymer having a reactive silicon group;
(B) a bivalent tin carboxylate wherein the carbon atom adjacent to the carbonyl group is quaternary;
(C) an amine compound having no reactive silicon group, and
(D) silica,
wherein the component (A) has a group represented by the formula (1)
—NR 1 —C(═O)— (1)
wherein R 1 represents hydrogen atom or substituted or unsubstituted organic group.
2. The curable composition according to claim 1 , wherein the component (B) is tin versatate.
3. The curable composition according to claim 1 , wherein the component (C) is a diamine compound having no reactive silicon group.
4. The curable composition according to claim 1 , wherein the component (D) is hydrophobic silica.
5. The curable composition according to claim 1 , wherein the component (D) is fumed silica and/or fine powdery silica.
6. A transparent cured article obtained by curing a moisture curable composition comprising:
(A). an organic polymer having reactive silicon group(s), wherein the organic polymer is a mixture composed of a polyoxypropylene polymer having a reactive silicon group, and a (meth)acrylic acid ester polymer having a reactive silicon group;
(B). a bivalent tin carboxylate wherein the carbon atom adjacent to the carbonyl group is quaternary;
(C). an amine compound having no reactive silicon group; and
(D). silica.
7. The transparent cured article according to claim 6 , wherein the transmittance of all light rays is 70% or more when the article is a sample having a thickness of 5 mm.
8. The transparent cured article according to claim 6 , wherein curing time is 7 days or less under the condition of 23° C. and 50% relative humidity.
9. A moisture curable composition for transparent cured article comprising:
(A). an organic polymer having reactive silicon group(s), wherein the organic polymer is a mixture composed of a polyoxypropylene polymer having a reactive silicon group, and a (meth)acrylic acid ester polymer having a reactive silicon group;
(B). a bivalent tin carboxylate wherein the carbon atom adjacent to the carbonyl group is quaternary;
(C). an amine compound having no reactive silicon group; and
(D). silica.