High solids can coating composition containing epoxy, acrylic and aminoplast resins

A high solids exterior can coating composition consisting essentially of:

• A. a vehicle blend consisting essentially of:
• 1. from 5 to 22% by weight of acrylic polymer having a weight average molecular weight determined by gel permeation chrometography using a polystyrene standard, of from at least 50,000 to 90,000,
• 2. from 25 to 50% by weight of polyester having the structure:
• ##STR1## or the isomer through the secondary hydroxyl group or mixtures thereof, wherein X= ##STR2## and wherein n=0-10 and at least 70% by weight is n=3 or less provided that only a maximum of 25% by weight of n=0;
• and wherein the polyester has a number average molecular weight not exceeding 1,000, determined by gel permeation chromatography using a polypropylene glycol standard;
• 3. from 5 to 15% by weight of castor oil which has not been dehydrated;
• 4. from 20 to 50% of an aminoplast resin;
• 5. pigments comprising TiO.sub.2 and talc in proportions of from 10 to 90% by weight of each, the ratio of pigments to vehicle solids being in the range of 0.8:1 to 1.4:1 by weight;
• and
• 6. from 0.2 to 2.0% by weight of a catalyst which is a blocked sulfonic acid catalyst wherein the sulfonic acid is selected from the group consisting of methane sulfonic acid, paratoluene sulfonic acid alkyl benzene sulfonic acid wherein the alkyl group contains 2-12 carbon atoms, and 2-methacryloxyethyl sulfonic acid, its homopolymers and copolymers;
• and
• B. aliphatic and aromatic hydrocarbon solvents;
• said coating composition having a solids contents of at least 70% by weight.