Polyester coating composition for metal substrates comprising oxirane-functional acrylic resin

摘要

The present invention provides novel packaging articles, e.g., food and beverage cans. Preferred cans typically comprise a body portion and an end portion, wherein at least one of the body and end portions are aluminum and are coated on at least one major surface with a coating composition of the present invention. Suitable coating compositions of the present invention comprise: one or more polyester resins, wherein at least one of the polyester resins has a glass transition temperature (“Tg”) less than about 50° C., and wherein the polyester resin is formed by the reaction of one or more polyacid molecules and one or more polyol molecules; and a crosslinker. The present invention also provides a method of making such cans.

主权项

1. An article, comprising:
a metal beverage can having a body portion and an end portion, wherein the end portion is an aluminum beverage can end coated on an interior surface with a coating obtained from a coating composition comprising:
between about 60 and 95 weight percent of one or more polyester resins, based on solids content of the coating composition, wherein at least one polyester resin has a Tg of less than about 50° C.; andan oxirane-functional acrylic resin, wherein the acrylic resin is present in an amount up to about 20% by weight of the coating composition, based upon the total resin solids in the coating composition;wherein the coating composition is substantially free of mobile BPA and aromatic glycidyl ether compounds; and wherein the coating on the interior surface of the beverage can end passes less than 10 milliamps of current while being exposed for 4 seconds to an electrolyte solution containing 1% by weight of NaCl dissolved in deionized water.