CURABLE COMPOSITION
The present invention has its object to provide a curable composition which comprises an amidine compound as a non-organotin catalyst and shows good elongation, flexibility, surface curability, depth curability and adhesiveness; the above object can be achieved by a non-organotin curable composition which comprises: (A) an organic polymer containing a silyl group capable of crosslinking under siloxane bond formation, the silyl group being a group represented by the general formula (1): —SiR 1 X 2 ; (B) an amidine compound (B-1) as a silanol condensation catalyst; and (C) a carboxylic acid, wherein the ratio between the number of moles (b) of all nitrogen atoms in the (B-1) component of the composition and the number of moles (c) of all carboxyl groups in the (C) component of the composition, namely the ratio (b)/(c), is higher than 2.
1 . A non-organotin curable composition
which comprises:
(A) an organic polymer containing a silyl group capable of crosslinking under siloxane bond formation, said silyl group being a group represented by the general formula (1):
—SiR 1 X 2 (1)
(wherein R 1 represents a group selected from among alkyl groups containing 1 to 20 carbon atoms, aryl groups containing 6 to 20 carbon atoms, aralkyl groups containing 7 to 20 carbon atoms and triorganosiloxy groups represented by (R′) 3 SiO— in which R′ is a hydrocarbon group containing 1 to 20 carbon atoms, the three R′ groups may be the same or different, and X represents a hydroxyl group or a hydrolyzable group and the two X groups may be the same or different);
(B) an amidine compound (B-1) as a silanol condensation catalyst; and
(C) a carboxylic acid,
wherein the ratio between the number of moles (b) of all nitrogen atoms in the (B-1) component of the composition and the number of moles (c) of all carboxyl groups in the (C) component of the composition, namely the ratio (b)/(c), is higher than 2.
2 . The curable composition according to claim 1 ,
wherein a main chain skeleton of the (A) component organic polymer contains at least one atom selected from among a hydrogen atom, a carbon atom, a nitrogen atom, an oxygen atom and a sulfur atom.
3 . The curable composition according to claim 1 ,
wherein the (A) component organic polymer comprises at least one species selected from the group consisting of polyoxyalkylene polymers, saturated hydrocarbon polymers and (meth)acrylate ester polymers.
4 . The curable composition according to claim 3 ,
wherein the polyoxyalkylene polymer is a polyoxypropylene polymer.
5 . The curable composition according to claim 1 ,
which contains the (B-1) component in an amount of 0.001 to 20 parts by weight per 100 parts by weight of the component (A).
6 . A sealant
which comprises the curable composition according to claim 1 .
7 . An adhesive
which comprises the curable composition according to claim 1 .