Curable composition
View Patent ↗The object of the present invention is to significantly improve weather resistance over a long period of time of the cured product of the invention, while maintaining physical properties, such as tensile properties and rubber-like elasticity, at levels required of sealing compositions for use in general buildings. The curable composition of the invention is a curable composition which comprises a vinyl polymer having a reactive silicon containing group (a), such as a (meth) acrylic polymer having a reactive silicon containing group, a polyoxyalkylene polymer having a reactive silicon containing group (b), such as a polyoxypropylene having a reactive silicon containing group, and a plasticizer having an acrylic component (c), such as an acrylic polymer, and is reacted and crosslinked in the presence of moisture to provide a rubbery cured product.
1. A curable composition
which comprises a vinyl polymer having a reactive silicon containing group (a), a polyoxyalkylene polymer having a reactive silicon containing group (b), and a plasticizer having an acrylic component (c), wherein the plasticizer is at least one of a (meth) acrylic polymer with a molecular weight distribution of not more than 1.8 as prepared by the living radical polymerization technique, and an acrylic polymer produced by subjecting acrylate monomers to continuous bulk polymerization.
2. The curable composition according to claim 1 ,
wherein the vinyl polymer having a reactive silicon containing group (a) is a (meth)acrylic polymer.
3. The curable composition according to claim 1 ,
wherein the polyoxyalkylene polymer (b) is at least one member selected from the group consisting of poly(ethylene oxide), poly(propylene oxide), polypropylene oxide-ethylene oxide copolymer, and poly(butylene oxide).
4. The curable composition according to claim 1 ,
wherein the main chain skeleton of the polyoxyalkylene polymer (b) is a polymer synthesized by using a double metal cyanide complex catalyst.
5. The curable composition according to claim 1 ,
wherein the number average molecular weight of the polyoxyalkylene polymer (b) is 500 to 50,000.
6. The curable composition according to claim 5 ,
wherein the number average molecular weight of the polyoxyalkylene polymer (b) is 1,000 to 30,000.
7. The curable composition according to claim 1 ,
wherein the number average molecular weight of the polyoxyalkylene polymer (b) is not less than 12,000.
8. The curable composition according to claim 7 ,
wherein the number average molecular weight of polyoxyalkylene polymer (b) is not less than 15,000.
9. The curable composition according to claim 8 ,
wherein the number average molecular weight of polyoxyalkylene polymer (b) is not less than 16,000.
10. The curable composition according to claim 3 ,
wherein the polyoxyalkylene polymer (b) is a polyoxypropylene polymer.
11. The curable composition according to claim 10 ,
wherein the main chain skeleton of the polyoxyalkylene polymer (b) is a substantially straight-chain polymer.
12. The curable composition according to claim 1 ,
wherein the reactive silicon containing group of the polyoxyalkylene polymer (b) is a group comprising one silicon atom and two hydrolyzable groups attached thereto.
13. The curable composition according to claim 12 ,
wherein the reactive silicon containing group of the polyoxyalkylene polymer (b) is dimethoxymethylsilyl group.
14. The curable composition according to claim 1 ,
wherein the number average molecular weight of the vinyl polymer having a reactive silicon containing group (a) is 5,000 to 30,000.
15. The curable composition according to claim 1 ,
wherein the weight ratio of the vinyl polymer having a reactive silicon containing group (a) to the polyoxyalkylene polymer having a reactive silicon containing group (b) is 25/75 to 45/55.
16. The curable composition according to claim 1 ,
wherein the number average molecular weight of the plasticizer having an acrylic component (c) is 500 to 15,000.
17. The curable composition according to claim 16 ,
wherein the number average molecular weight of the plasticizer having an acrylic component (c) is 1,000 to 8,000.
18. The curable composition according to claim 1 ,
wherein the amount of use of the plasticizer having an acrylic component (c) is 5 to 150 weight parts relative to a combined total of 100 weight parts of the vinyl polymer having a reactive silicon containing group (a) and polyoxyalkylene polymer having a reactive silicon containing group (b).
19. The curable composition according to claim 18 ,
wherein the amount of use of the plasticizer having an acrylic component (c) is 10 to 120 weight parts relative to a combined total of 100 weight parts of the vinyl polymer having a reactive silicon containing group (a) and polyoxyalkylene polymer having a reactive silicon containing group (b).
20. The curable composition according to claim 19 ,
wherein the amount of use of the plasticizer having an acrylic component (c) is 20 to 100 weight parts relative to a combined total of 100 weight parts of the vinyl polymer having a reactive silicon containing group (a) and polyoxyalkylene polymer having a reactive silicon containing group (b).
21. The curable composition according to claim 1 ,
which further comprises another plasticizer in addition to the plasticizer having an acrylic component (c).
22. The curable composition according to claim 21 ,
wherein the weight ratio of the plasticizer having an acrylic component (c) to said other plasticizer is not less than 70/30.
23. The curable composition according to claims 1 , which is for use as a siding board joint sealant.
24. The curable composition according to claim 23 ,
wherein the siding board is a ceramic siding board.
25. The curable composition according to claims 1 ,
which further comprises a scaly or particulate substance not smaller than 0.1 mm in diameter.
26. The curable composition according to claim 1 , which further comprises a balloon.
27. The curable composition according to claim 26 ,
wherein the diameter of the balloon is not less than 0.1 mm.