Abstract: An aqueous epoxy resin system suitable for coatings comprises (a) water, (b) at least one epoxy resin and (c) a curing agent prepared by (i) reacting at least one polyamine having at least 3 active amine hydrogen atoms per molecule and at least one epoxy resin in an epoxy equivalent to to polyamine mole ratio of from 0.9:1 to 1:10 to obtain an amine-terminated intermediate; (ii) reacting the amine-terminated intermediate with from 0.5 to 25 weight percent, based on the amine-terminated intermediate, of an acid-terminated polyalkylene glycol to yield an amine-terminated curing agent. The amine-terminated intermediate can be capped with a monoepoxide in an amine hydrogen to epoxy groups ratio of from about 1.5:1 to 30:1 prior to reaction with the acid-terminated polyalkylene glycol, or the amine-terminated curing agent following step (ii) can be capped with a monoepoxide in an amine hydrogen atoms to epoxy groups ratio of from about 2:1 to 30:1.
Type:
Grant
Filed:
November 19, 1999
Date of Patent:
October 24, 2000
Assignee:
Shell Oil Company
Inventors:
Charles J. Stark, deceased, Gayle Edward Back, Jimmy D. Elmore, Kalyan Ghosh, Pen-Chung Wang, Kailash Dangayach