GB865314A - Preparation of polyglycidyl aromatic polyamines and resinous compositions made therefrom - Google Patents

Abstract

Heat curable resinous compositions comprise a hardening agent and a polyglycidyl aromatic polyamine obtained by reacting 1 mol of an aromatic primary polyamine with at least 2 mols of an epihalohydrin for each primary amine group, in the substantial absence of alkali and at a temperature not in excess of 80 DEG C., reacting the resulting polyamine epihalohydrin with at least a storchiometric amount of alkali and recovering the resulting polyglycidyl polyamine. Suitable hardeners are polyhydric phenols, primary and secondary polyamines, polyamides, and polymercaptans. Suitable catalysts which may be present are alkalis, amines, and quaternary ammonium compounds. The hardener may be used in proportions from 0.7 to 1,3 of the stoichiometric proportions. The glycidyl derivatives may be mixed at temperatures from 25 DEG -100 DEG C. and the catalyst or hardener is added, either as such or in solution. The composition is poured into a mould and cured at temperatures from 25 DEG -200 DEG C. The polyglycidyl polyamines may be used in combination with epoxy ethers of polyhydric phenols having a 1,2-epoxy equivalency greater than one, e.g. the glycidyll ethers of bisphenols. Examples describe casting compositions using the tetraglycidyl derivative of 4, 41-diamino-diphenyl methane with (2) the diglycidyl ether of bisphenol A, methanolic KOH and bisphenol A; (3) diglycidyl aniline, methanolic KOH, and bisphenol A; (4) methanolic KOH and bisphenol A and (5) 4, 41-diamine diphenyl methane.ALSO:Polygycidyl aromatic polyamines having at least an 80% epoxy content are made by reacting 1 mol of an aromatic primary polyamine with at least 2 mols of an epihalohydrin for each primary amine group present in the polyamine, in the substantial absence of alkali and at a temperature not in excess of 80 DEG C., reacting the resulting polyamine epihalohydrin with at least a stoichiometric amount of alkali and recovering the resulting polyglycidyl polyamine. It is preferred to carry out the first step in the presence of water, using up to a 300% (molar) excess of epihalohydrin, the excess being distilled off under reduced pressure after completion of the first stage. It is advantageous to use 5 to 25% by weight excess of alkali in the second stage, usually as a 50% by weight aqueous solution. An organic solvent mixture, such as toluene-alcohol, may be present in the second step. Examples of suitable polyamines are m- and p-phenylene diamine, benzidene and 4, 41 diamine diphenyl methane. The polyglycyl polyamines may be used in the preparation of thermosetting casting compositions (see Group IV(a)).