Inventors:
Edward J. Holzrichter - Riverside CA
Edward A. Lasher - Beverly Hills CA
Assignee:
Whittaker Corporation - Los Angeles CA
International Classification:
C08L 6126
C08G 1232
Abstract:
Water-soluble ester intermediates characterized by having 2 and 3 ester groups per molecule are made by condensing (a) a polyol having 2 to 3 hydroxyl groups per mol and a carbon/oxygen ratio between 5:3 and 7:3 with (b) a polycarboxylic acid having a carboxyl functionality of 2 to 3, using an equivalents ratio of polyol to polycarboxylic acid so that the ester intermediate has a hydroxyl functionality of about 3 and using a ratio of 1 mol of polyol per carboxyl group. The ester intermediates are combined in aqueous media with specific amounts of water-soluble aminoplast resin and the resulting combination is cured at elevated temperatures to produce cross-linked, water-insoluble coatings which are suitable as can and coil coatings. Small amounts of epoxy resin which is soluble in the ester intermediate may be used to provide coatings having improved adhesion, particularly under certain adverse conditions.