Epoxy hardener systems based on aminomethylene-ethyleneureas
AssigneeARDES Enterprises, Inc.
InventorRichard Schile
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Abstract
An epoxy-hardener system is provided having relatively long latency periods combined with relatively short cure times at low cure temperatures. The hardeners of the present invention are ureidoamines and their derivatives, which are chelates of ureido compounds and amines. The ureidoamines are prepared by reacting an amine with the ureido compound and aqueous formaldehyde without a catalyst. Complexes of ureidoamine hardeners with various blocking agents are prepared in the melt. The hardener is prevented from curing the epoxy by the reaction between the hardener and the blocking agent. The blocked hardener is then blended with the epoxy, usually by warming the mixture briefly at about 50-60 degrees C.
Claims25
A composition comprising:
- an epoxy resin;
- and
- a reaction product that contains at least one ureidoamine or a derivative thereof as a hardener and a blocking agent for blocking said ureidoamine or derivative.
A blocked hardener composition for mixing with an epoxy to cure the epoxy, the blocked hardener composition comprising:
- a ureidoamine or a derivative thereof;
- and
- a hydroxy acid selected from the group consisting of 2,2-bis(hydroxymethyl)butyricacid and 2,2-bis(hydroxymethyl)propionicacid and glycolic acid, or methylenebis(ethyleneurea), or a combination of at least one of said hydroxy acids and methylenebis(ethyleneurea);
- wherein the blocked hardener is soluble in epoxy resin.
Dependencies are inferred from the claim text.