GB955748A - Improvements relating to polyepoxide resins - Google Patents

Abstract

A curable composition comprises a polyepoxide having more than one epoxy group per molecule and 2-50%, based on the weight of the polyepoxide, of an aminodiboron curing agent having one of the following formulae:- <FORM:0955748/C3/1> <FORM:0955748/C3/2> <FORM:0955748/C3/3> where R is H, an unsubstituted saturated aliphatic hydrocarbon radical of 1-12C, an unsubstituted saturated cycloaliphatic hydrocarbon radical of 5-12C, an unsubstituted aromatic hydrocarbon radical, a substituted aromatic hydrocarbon radical having 1 or more aliphatic hydrocarbon substituents of 1-6C, or a substituted aromatic hydrocarbon radical having 1 or more alkoxyl substituents of 1-6C, and R1 and R11, which may be the same or different, are unsubstituted saturated aliphatic hydrocarbon radicals of 1-12C, unsubstituted saturated cycloaliphatic hydrocarbon radicals of 5-12C, unsubstituted aromatic hydrocarbon radicals, substituted aromatic hydrocarbon radicals having 1 or more aliphatic hydrocarbon substituents of 1-6C, or substituted aromatic hydrocarbon radicals having 1 or more alkoxyl substituents of 1-6C, and R111 represents an unsubstituted alkylene radical of 2-3C, a substituted alkylene radical of 2-3C in length having 1 or more aliphatic or aromatic hydrocarbon substituents, an unsubstituted o-phenylene radical or a substituted o-phenylene radical having 1 or more aliphatic hydrocarbon substituents. Long lists of suitable compounds are given of which the following are used in the examples:-a glycidyl polyether derived from epichlorhydrin and bisphenol A, the ester of 2-methyl-4, 5-epoxy-1-hydroxymethyl cyclohexane and 2-methyl-4, 5-epoxy cyclohexane-1-carboxylic acid, an epoxidized polybutadiene, and an epoxidized soya bean oil; tetra-(dimethylamino)diboron, tetra-(anilino) diboron, tetra(n-hexylamino) diboron, sym-bis-(dimethylamino)-diethyldiboron, sym-bis-(diethylamino) diphenyl diboron, sym-bis-(p-toluidino) diisopropyldiboron, sym-bis-(cyclohexylamino) bis-p-ethoxy-phenyl diboron, sym-bis-(cyclohexylamino) bis-(p-ethoxyphenyl) diboron, 2-(1, 3, 2-diazaboximyl)-1, 3, 2-diazaborinane, 2-(1, 3, 2-benzodiazaborolo)-1, 3, 2-benzodiazaborole, and 2-(1, 3-dimethyl-1, 3, 2-diazaborolo)-1, 3-dimethyl-1, 3, 2-diazaborole. Optional additives specified are glass, mineral, and metal fibres, asbestos, mica, iron oxide, bentonite, silica, TiO2 and Cd yellow. Using a mixture of an epoxidized cycloolefinic compound and 15-30% by weight of tetra (anilino) diboron produces on curing with heat a foamed product Ex. 5 illustrates this using the ester of 2-methyl-4, 5-epoxy-1-hydroxymethyl cyclohexane and 2-methyl-4, 5-epoxy cyclohexan-1-carboxylic acid with 20% of tetra (aniline) diboron and curing at 100 DEG C.