Patent ID: 7723426

Claim:
A process for the preparation of a one-pack, hydrolysable vinyl silane modified (meth)acrylic latex interpolymer composition that is shelf-stable for at least one year at room temperature after natural aging comprising the steps: a) preparing a mixture of water, surfactant and buffer which ranging in concentration of 0.4 to 0.7 weight percent of the aqueous phase to provide an initial pH in the range above 8 and heating to the reaction temperature; b) preparing a mixture of 1 to 5 mole percent vinylalkoxysilane and (meth)acrylic monomer wherein the vinylalkoxysilane is selected from the group consisting of vinyltriethoxysilane and vinylmethyldiethoxysilane; c) adding the polymerization initiator to the mixture of step (a); d) adding a portion of the mixture of step (b) and additional polymerization initiator to the mixture of step (c) and allowing the polymerization reaction to run at the reaction temperature; e) adding continuously the remainder of the mixture of step (b), and additional initiator the mixture of step (d) and maintaining the pH of the aqueous phase in the range above 6.5 by adding additional buffer; f) allowing the polymerization reaction to run for the mixture of step (e) and simultaneously, hydrolyzing the silane in the mixture of step (e) to release from greater than 19 percent to no more than 60 percent alcohol; g) incorporating the hydrolyzed silane of step (f) into the polymer; h) adding additional polymerization initiator to complete the polymerization reaction; and i) adjusting the pH of the hydrolysable vinyl silane modified (meth)acrylic latex interpolymer composition of step (h) in the range above 6.5 by adding a buffer, wherein the mixture of step (h) has, after aging for at least one year at room temperature and then applying to a metal panel and curing for 7 days at room temperature in the absence of an added catalyst, at least 75 methyl ethyl ketone double rubs according to ASTM D 4752-87.