Curable composition
View Patent ↗The invention provides a curable composition which comprises a polyoxyalkylene polymer having a reactive silicon group and a (meth)acrylate copolymer and exhibits excellent weather resistance for a prolonged period. This composition comprises 100 parts by weight of a polyoxyalkylene polymer (A) having at least one silicon-containing functional group capable of causing crosslinking through the formation of a siloxane linkage and 20 to 1000 parts by weight of a (meth)acrylate copolymer (B) having a hindered amine structure.
1. A curable composition comprising: 100 parts by weight of a polyoxyalkylene polymer (A) having at least one functional group containing silicon, the functional group being crosslinked by forming a siloxane bond; and at least 25 to 1,000 parts by weight of a (meth)acrylic ester copolymer (B) having a hindered amine structure, wherein the (meth)acrylic ester copolymer (B) is formed from a monomer mixture comprising (meth)acrylic ester and a copolymerizable hindered amine compound.
2. A curable composition according to claim 1 , wherein the (meth)acrylic ester copolymer (B) is prepared by copolymerizing a reactive hindered amine compound expressed by Formula (I):
(Where R 1 represents a hydrogen atom or an alkyl group having a carbon number in the range of 1 to 18, R 2 represents a hydrogen atom or a cyano group, R 3 represents a hydrogen atom or an alkyl group having a carbon number of 1 or 2, R 4 represents a hydrogen atom or an alkyl group having a carbon number of 1 or 2, and X represents an oxygen atom or an amino group).
3. A curable composition according to claim 1 , wherein at least one of (methyl)acrylic ester monomer units constituting the (meth)acrylic ester copolymer (B) has an alkyl group having a carbon number of 8 or more.
4. A curable composition according to claim 1 , wherein the (meth)acrylic ester copolymer (B) is prepared by copolymerizing a vinyl monomer containing a reactive silicon group.
5. A curable composition according to claim 1 , wherein the functional group containing silicon of the polyoxyalkylene polymer (A) is a reactive alkoxysilyl group.
6. A curable composition according to claim 1 , wherein the (meth)acrylic ester copolymer (B) contains 0.5 to 10 parts by weight of a monomer unit containing the hindered amine structure relative to 100 parts by weight of the polyoxyalkylene polymer (A).
7. A curable composition according to claim 1 , wherein the (meth)acrylic ester copolymer (B) has a structure formed by copolymerizing only the (meth)acrylic ester, a compound having a polymerizable unsaturated bond and a reactive silicon group, and a the copolymerizable hindered amine compound.