| 摘要 |
A curable composition comprises a polyepoxide and 5-50% of its weight, of a borate curing agent in which boron is bonded to at least one phenoxy group which is substituted by tertiary alkyl radicals in the 2 and 6 positions, and may be further substituted. Suitable borates are listed and may be represented by one of the following formulae <FORM:0988375/C3/1> in which R is a tertiary alkyl radical; R1 is alkyl, alkenyl or alkynyl, and R11 is alkylene. The compositions may include conventional additives, e.g. fillers, thixotropic agent, colouring materials. Examples describe the curing of various combinations of (1) epoxy resins:-a condensate of epichlorhydrin and bisphenol A; an eppxidized polybutadiene; an epoxidized soyabean oil; and the ester of 2-methyl-4, 5-epoxy-1-hydroxymethyl cyclohexane and 2 - methyl - 4,5 - epoxy - cyclohexan - 1 - carboxylic acid, and (2) curing agents:-2,6-di-t-butyl-4-methylphenyl di-n-propyl borate; 2,6-di-t-butylphenyl diallyl borate; di-(2,4,6,-tri-t-amyl phenyl)-n-decyl borate; di-(2,6-di-t-octyl phenyl) methyl borate; 4,41-methylene-bis-(2, 6-di-t-butyl phenyl) di-n-butyl borate; 2,6-di-t-amyl phenyl-1,6-hexylene glycol borate; 2,6-di-t-octyl phynyl-1,4-butylene glycol borate; 2,6-di-t-butyl phenoxy dihydroxyborane; 2,6-di-t-decylphenoxy dihydroxyborane. |
