Curable composition and methods for improving recovery properties and creep properties

Abstract

Disclosed are a curable composition characterized by using a curable composition including an organic polymer (A1) having one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds in which the one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds are silicon-containing functional groups each having three or more hydrolyzable groups on one or more silicon atoms thereof; and a method for controlling the recovery properties, durability and creep resistance of the cured article. Herewith, the present invention provides a curable composition capable of giving a cured article excellent in recovery properties, durability and creep resistance, and a method for controlling the recovery properties, durability and creep resistance of the cured article.

1 . A curable composition comprising:
 an organic polymer (A1) having one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds in which the one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds are silicon-containing functional groups each having three or more hydrolyzable groups on one or more silicon atoms thereof, and a main chain skeleton of the organic polymer (A1) is a polyoxyalkylene polymer; and   at least one silanol condensation catalyst selected from the group consisting of a tin carboxylate (C), an organotin catalyst (D), and a non-tin catalyst (E),   wherein the curable composition further comprises any one of the following features (1) to (7):   (1) the curable composition further comprises a microballoon (F);   (2) the proportion of the organic polymer (A1) in the total amount of the curable composition is 5 to 28 wt %;   (3) the curable composition further comprises an epoxy resin (I);   (4) the organic polymer (A1) is an organic polymer (A2) having one or more silicon-containing functional groups capable of crosslinking by forming siloxane bonds in which the one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds are represented by the general formula (2):
   —Si(OR 1 ) 3   (2)
 
   where three R 1 s each are independently a monovalent organic group having 2 to 20 carbon atoms, and   the curable composition further comprises an aminosilane coupling agent (G) having a group represented by the general formula (3):
   —SiR 2   a (OR 3 ) 3-a   (3)
 
   where aR 2 s each are independently a monovalent organic group having 1 to 20 carbon atoms, (3−a)R 3 s each are independently a monovalent organic group having 2 to 20 carbon atoms, and a represents 0, 1 or 2;   (5) the organic polymer (A1) is an organic polymer (A2) having one or more silicon-containing functional groups capable of crosslinking by forming siloxane bonds in which the one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds are represented by the general formula (2):
   —Si(OR 1 ) 3   (2)
 
   where three R 1 s each are independently a monovalent organic group having 2 to 20 carbon atoms, and   the curable composition further comprises an aminosilane coupling agent (H) having a group represented by the general formula (4):
   —SiR 4   b (OCH 3 ) c (OR 5 ) 3-b-c   (4)
 
   where bR 4 s each are independently a monovalent organic group having 1 to 20 carbon atoms, (3−b−c)R 5 s each are independently a monovalent organic group having 2 to 20 carbon atoms, b represents 0, 1 or 2, and c represents 1, 2 or 3; the relation, 3−b−c≧0, is to be satisfied, and   the curable composition is obtained by pre-aging;   (6) the organic polymer (A1) is a polyoxyalkylene polymer (A3) having one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds in which the one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds are represented by the general formula (2):
   —Si(OR 1 ) 3   (2)
 
   where three R 1 s each are independently a monovalent organic group having 2 to 20 carbon atoms, and   the curable composition further comprises a (meth)acrylate copolymer (A6) having one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds in which the one or more silicon-containing functional groups capable of cross-linking by forming siloxane bonds are represented by the general formula (2):
   —Si(OR 1 ) 3   (2)
 
   where three R 1 s each are independently a monovalent organic group having 2 to 20 carbon atoms, or   (7) the organic polymer (A1) is an organic polymer (A7) which has on average 1.7 to 5 silicon-containing functional groups capable of cross-linking by forming siloxane bonds per molecule.   
     
     
         2 . The curable composition according to  claim 1 ,
 wherein the silicon-containing functional groups capable of cross-linking by forming siloxane bonds each are a trimethoxysilyl group and/or a triethoxysilyl group.   
     
     
         3 . The curable composition according to  claim 1 ,
 wherein silicon-containing functional groups capable of crosslinking by forming siloxane bonds each are a group represented by the general formula (2):
   —Si(OR 1 ) 3   (2)
 
   where three R 1 s each are independently a monovalent organic group having 2 to 20 carbon atoms.   
     
     
         4 . The curable composition according to  claim 3 ,
 wherein the silicon-containing functional groups capable of cross-linking by forming siloxane bonds each are a triethoxysilyl group.   
     
     
         5 . The curable composition according to  claim 1 ,
 wherein the organic polymer (A1) is an organic polymer obtained by an addition reaction between an organic polymer having one or more unsaturated groups introduced into the terminals thereof and a hydrosilane compound represented by the general formula (1):
   H—SiX 3   (1)
 
   where X represents a hydroxy group or a hydrolyzable group, and three X's may be the same or different.   
     
     
         6 . The curable composition according  claim 3 ,
 wherein the organic polymer (A1) is an organic polymer obtained by an addition reaction between an organic polymer having one or more unsaturated groups introduced into the terminals thereof and a hydrosilane compound represented by the general formula (5):
   H—Si(OR 1 ) 3   (5)
 
   where three R 1 s each are independently a monovalent organic group having 2 to 20 carbon atoms.   
     
     
         7 . The curable composition according  claim 1 ,
 wherein the organic polymer (A1) is an organic polymer which substantially does not contain an amide segment (—NH—CO—) in the main chain skeleton thereof.   
     
     
         8 . The curable composition according  claim 1 ,
 wherein the silanol condensation catalyst is a tin carboxylate (C), and   the curable composition further comprises an amine compound.   
     
     
         9 . The curable composition according  claim 8 , which further comprises an organotin catalyst (D). 
     
     
         10 . The curable composition according  claim 1 ,
 wherein the organotin catalyst (D) is at least one selected from the group consisting of dialkyltin carboxylates, dialkyltin oxides, reaction products between tetravalent tin and low molecular-weight, hydrolyzable silicon group-containing silicon compounds, and compounds represented by the formula Q g Sn(OZ) 4-g  or [Q 2 Sn(OZ)] 2 O, where Q represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, Z represents a monovalent hydrocarbon group having 1 to 20 carbon atoms or an organic group having therein one or more functional groups capable of forming coordination bonds with Sn, and g is any one of 0, 1, 2, and 3.   
     
     
         11 . The curable composition according  claim 1 ,
 wherein the tin carboxylates (C) is a tin carboxylate (C1) in which the α-carbon atom of the carboxyl group is a quaternary carbon atom.   
     
     
         12 . The curable composition according  claim 1 , wherein non-tin catalyst (E) is a carboxylic acid. 
     
     
         13 . The curable composition according  claim 12 , which further comprises an amine. 
     
     
         14 . The curable composition according  claim 12 ,
 wherein the carboxylic acid is a carboxylic acid in which the acarbon atom of the carboxyl group is a quaternary carbon atom.   
     
     
         15 . The curable composition according  claim 1 ,
 wherein the microballoon (F) is hollow bodies constituted from an inorganic material.   
     
     
         16 . The curable composition according  claim 1 ,
 wherein the group represented by the general formula (3) is a triethoxysilyl group.