Patent ID: 6893680
Filing Date: 2005-05-17
Classification: C08G,C08K,C09D,C23C

Abstract:
1. A coating having improved adhesion to metal, comprising, (I) a first compound having an acid number of from 70 to 120 mg KOH/g, a hydroxyl number of from 200 to 400 mg KOH/g, a number average molecular weight of from 150 to 3000, and which is the reaction product of (a) at least one difunctional carboxylic acid, (b) at least one trifunctional polyol, (c) at least one chain stopper, and (d) phosphoric acid, (II) a second compound comprising one or more carboxy phosphate esters having the formula: wherein M is hydrogen, metal, or ammonium, x is a number from 0 to 3, R is an C 5 -C 40 aliphatic group having one or more —COOR 1 groups, wherein R 1 is H, metal, ammonium, C 1 -C 6 alkyl, or C 6 -C 10 aryl, and (III) a third compound comprising one or more solvents providing low surface tension and promoting surface wetting, wherein said coating applied to a sanded galvanized steel panel and flash dried for 5 minutes and then baked between 120 and 145° F. for 30 minutes, demonstrates a GM adhesion value of 5 or greater following 15 minute time lapse after removal from bake.