GB909313A - Improvements in or relating to the production of polyamine/epoxide reaction products - Google Patents

Abstract

Reaction products are prepared from poly-(aminomethyl)-benzenes containing at least three amino-hydrogen atoms and glycidyl compounds, in such proportions that at least 4 such hydrogen atoms are available per epoxy group. The reaction products are used as secondary curing agents for polyepoxides. The glycidyl compounds specified are glycidyl esters of carboxylic acids, polyglycidyl polyethers and glycidyl ethers. When a polyglycidyl compound is used the poly-(aminomethyl)-benzene should have at least four amino-hydrogen atoms. Any remaining nitrogen valencies are satisfied by alkyl and preferably methyl groups. The glycidyl compound is added to an excess of the polyamine (there are preferably 4-25 amino hydrogen atoms available per epoxy group) and they are reacted at temperatures between 20 DEG and 150 DEG C. Optional additives include accelerators, e.g. phenol, and triphenyl phosphite; fluxing agents, e.g. urea-formaldehyde resins, and solvents, e.g. butanol and toluene. The reaction products are used to cure polyepoxides such as polyglycidyl polyethers. Optional additives include fillers, e.g. glass fibres and coal tar; pigments, e.g. titanium dioxide, and solvents, e.g. dioctyl phthalate. In a typical example, meta-xylylene diamine, a glycidyl polyether of bisphenol A, butyl glycidyl ether, triphenyl phosphite, a urea-formaldehyde resin, butanol and toluene are reacted by heating at 60 DEG C. for one hour with stirring. The reaction product is mixed with a glycidyl polyether of bisphenol A containing butyl glycidyl ether to give a lacquer which is cured at room temperature. In comparative examples the reaction product used in the lacquer is replaced meta-phenylene diamine, a cyclo-aliphatic polyamine, the reaction products of these amines with epoxides and metaxylylene diamine.ALSO:Reaction products are prepared from poly-(aminomethyl)-benzenes containing at least three amino-hydrogen atoms and glycidyl compounds, in such proportions that at least 4 such hydrogen atoms are available per epoxy group. The glycidyl compounds specified are polyglycidyl polyethers, e.g. diphenylol propane diglycidyl ether and glycerol polyglycidyl ethers; butyl glycidyl ether; phenyl glycidyl ether and glycidyl esters of carboxylic acids. Meta-xylylene diamine is specified as a poly-(aminomethyl)-benzene. The products are used as curing agents for epoxy resins.