COATING COMPOSITION OF A HYDROXYL-FUNCTIONAL BLOCK COPOLYMER POLYESTER

摘要

A liquid coating composition particularly adapted for coating cans. The composition comprises a curable, hydroxyl functional block copolymer which is the reaction product of a 1,2-epoxy resin and a carboxyl functional polyester resin, and a hydroxyl-reactive crosslinking agent providing desirably at least 2.0 equivalents of hydroxyl reactive functional groups per hydroxyl equivalent of the block copolymer. The block copolymer desirably has a number average molecular weight in the range of 7000 to 30,000. Also disclosed is a method for formulating a coating composition utilizing craze resistance testing over an aging period to enable the choice of the quantity of curing agent to be used in the coating composition.