METHODS AND COMPOSITIONS FOR COATING SUBSTRATES

摘要

A method for applying a multilayer coating comprising a basecoat and a clearcoat is disclosed. The basecoat is a curable aqueous composition comprising (1) polymeric particles prepared from ethylenically unsaturated compounds including a multi-ethylenically unsaturated monomer and a keto or aldo-functional monomer, and (2) a polyhydrazide. A hydrophobic polyester is present in the aqueous composition to improve its humidity resistance.

主权项

1. A method of applying a multilayer coating to a substrate comprising:
(a) applying a color-imparting, pigment-containing basecoat composition to a substrate to form a curable color-imparting basecoat layer, and (b) applying a curable unpigmented coating composition to the basecoat layer to form a clear or transparent coating layer over the basecoat layer, wherein the basecoat layer is formed by depositing a polyhydrazide-containing curable aqueous composition comprising:
(i) a continuous phase comprising water, and(ii) a dispersed phase comprising:
(A) polymeric particles prepared from the polymerization of a mixture of ethylenically unsaturated monomer compounds, including ethylenically unsaturated monomers comprising:
(1) a multi-ethylenically unsaturated monomer and(2) an aldo or keto group-containing ethylenically unsaturated monomer; and(B) a hydrophobic polyester prepared from polymerizing the following mixture of monomers:
(I) a polyacid component comprising a dimer fatty acid and a tricarboxylic acid; and(II) a polyol component comprising a did and a diol with carboxylic acid groups.