Henkel Corporation

Robert M Moon

Shailesh Shah

Brian G Jewell

Jason L Chou

Provided are epoxy curing agents comprising the reaction product of reactants consisting essentially of a mono-alkylene polyamine having less than about 12 carbon atoms, an alicyclic diamine in an amount of greater than about 10% of the amine equivalents of said amine component, an aromatic mono-glycidyl ether having less than about 18 carbon atoms, and a diglycidyl ether of an aromatic diol having an average degree of oligomerization of less than about 3.5, wherein the ratio of primary amine equivalents of said alkylene polyamine to the total epoxide equivalents of said aromatic glycidyl ether and said diglycidyl ether of an aromatic diol is are greater than one, and the ratio of epoxide equivalents of said aromatic mono-glycidyl ether to epoxide equivalents of said diglycidyl ether of an aromatic diol is greater than one. The reaction product is preferably employed as a curing agent for an aqueous epoxy resin in a two component coating system wherein said curing agent, essentially free of acids, is mixed with an aqueous epoxy resin emulsion and then the resulting mixture is applied as a continuous coating to a rigid substrate, e.g. as an industrial maintenance coating.

Curing agents for aqueous epoxy resins

Provided are epoxy curing agents comprising the reaction product of reactants consisting essentially of an alkylene polyamine having less than about 12 carbon atoms, an aromatic mono-glycidyl ether having less than about 18 carbon atoms, and a diglycidyl ether of an aromatic diol having an average degree of oligomerization of less than about 3.5, wherein the ratio of primary amine equivalents of said alkylene polyamine to the total epoxide equivalents of said aromatic glycidyl ether and said diglycidyl ether of an aromatic diol is not essentially less than one, and the ratio of epoxide equivalents of said aromatic mono-glycidyl ether to epoxide equivalents of said diglycidyl ether of an aromatic diol is greater than one. The reaction product is preferably employed as a curing agent for an aqueous epoxy resin in a two component coating system wherein said curing agent, essentially free of acids, is mixed with an aqueous epoxy resin emulsion and then the resulting mixture is applied as a continuous coating to a rigid substrate, e.g. as an industrial maintenance coating.

A method of curing an epoxy resin comprising mixing an epoxy resin with a curing agent is provided. The curing agent is selected from the group consisting of (i) a mixture consisting essentially of 1,2-diaminocyclohexane and an aliphatic polyamine (preferably at a molar ratio of 1,2-diaminocyclohexane to aliphatic polyamine of from about 1:1 to about 16:1, preferably about 2.5:1 to about 6:1 and more preferably about 3:1 to about 5:1) and (ii) the reaction product of reactants consisting essentially of an amine component consisting essentially of 1,2-diaminocyclohexane and an aliphatic polyamine and an epoxide component. The epoxide component has an epoxy functionality greater than one and is preferably a diglycidyl ether of an aromatic diol having an average degree of oligomerization of less than about 3.5., preferably less than about 1.5, and preferably derived from an alkyl bis-phenol, e.g. bisphenol A. The ratio of primary amine equivalents of said amine component to the total epoxide equivalents of said epoxide component are greater than one, i.e. the molar equivalents of primary amine groups of said amine component are in excess of the molar equivalents of epoxide groups, e.g. a ratio of from about 1.5:1 to 50:1, preferably from about 3:1 to about 20:1, more preferably from about 6:1 to about 15:1.

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Maple Glenn, PA, United States of America

Robert M Moon