AQUEOUS DISPERSIONS AND COATINGS
The present invention provides aqueous dispersions that, for example, include the reaction product of an oxirane-functional vinyl addition polymer having an oxirane functionality between 0.5 and 5; an acid-functional polymer having an acid number 30 to 500; and a tertiary amine. Also described are coating compositions containing the dispersion and methods of forming the dispersion.
1 - 40 . (canceled)
41 . A method, comprising:
providing a coating composition comprising an aqueous dispersion including:
a reaction product of an oxirane-functional vinyl addition polymer, an acid-functional polymer, and a tertiary amine, and
a crosslinker; and
applying the aqueous dispersion to a metal substrate of a food or beverage can; and
hardening the aqueous dispersion to form a cured film.
42 . The method of claim 41 , wherein the crosslinker comprises a phenoplast resin.
43 . The method of claim 42 , wherein the phenoplast resin comprises the condensation product of an aldehyde with a phenol.
44 . The method of claim 43 , wherein the aldehyde comprises formaldehyde.
45 . The method of claim 43 , wherein the aldehyde comprises acetaldehyde.
46 . The method of claim 43 , wherein the phenol comprises phenol, cresol, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, or cyclopentylphenol.
47 . The method of claim 42 , wherein the phenoplast resin comprises a condensation product of (i) formaldehyde or acetaldehyde and (ii) phenol, cresol, p-phenylphenol, p-tert-butylphenol, p-tert-amylphenol, or cyclopentylphenol.
48 . The method of claim 42 , wherein the coating composition includes at least 5% by weight of the phenoplast resin, based on the total weight of resin solids in the coating composition.
49 . The method of claim 41 , wherein the acid-functional polymer is an acid-functional vinyl addition polymer.
50 . The method of claim 49 , wherein the acid-functional vinyl addition polymer comprises, by weight, 5 to 20 parts styrene, 30 to 70 parts alkyl (meth)acrylate, and 30 to 70 parts acid-functional monomer.
51 . The method of claim 41 , wherein the oxirane-functional vinyl addition polymer has a number average molecular weight of 2,500 to 20,000, and wherein the acid-functional polymer has a number average molecular weight of from 2,000 to 15,000.
52 . The method of claim 41 , wherein the coating composition is substantially free of BPA.
53 . The method of claim 41 , wherein the coating composition is substantially free of BPA and aromatic glycidyl ether compounds.
54 . The method of claim 41 , wherein the oxirane-functional vinyl addition polymer has an oxirane functionality of 0.5 to 5, and wherein the acid-functional polymer has an acid number of 30 to 500.
55 . The method of claim 41 , wherein the weight ratio of the oxirane-functional vinyl addition polymer to acid-functional polymer is between 90:10 and 50:50.
56 . The method of claim 41 , wherein the cured film includes a crosslinked polymer having a crosslink segment of the general formula:
—Y—C(R 2 )—C(R)(OH)—C(R 2 )—O—(O)C—X r —,
wherein: Y is a divalent organic group; X is a divalent organic group; R is H, or a C1 to C6 organic group; and r is 0 or 1.
57 . The method of claim 41 , wherein the food or beverage can comprises a two-piece drawn and ironed can.
58 . A method, comprising:
providing a coating composition comprising an aqueous dispersion including:
a reaction product of an oxirane-functional vinyl addition polymer, an acid-functional polymer, and a tertiary amine, and
a phenoplast resin;
spray applying the coating composition on an inside surface of a metal food or beverage can; and
hardening the aqueous dispersion to form a cured film.
59 . The method of claim 58 , wherein the acid-functional polymer is an acid-functional vinyl addition polymer.
60 . A method, comprising:
providing a coating composition that is substantially free of BPA and aromatic glycidyl ether compounds, the coating composition comprising an aqueous dispersion including:
a reaction product of an oxirane-functional vinyl addition polymer, an acid-functional vinyl addition polymer, and a tertiary amine, and
a phenoplast resin;
spray applying the coating composition on an inside surface of a metal food or beverage can; and
hardening the aqueous dispersion to form a cured film.