BATH FOR ELECTROPHORETIC LACQUERING CAPABLE OF CATHODIC DEPOSITION CONTAINING ADDITIVE FOR ENHANCING SURFACE APPEARANCE AND USE OF THE ADDITIVE IN COATING PROCESS

摘要

PURPOSE: To prevent the formation of craters on a paint film by adding, into an aqueous bath for cathodic electrophoretic lacquering, a small amount of an additive obtained by admixing a specific (meth)acrylic copolymer, a specific polyester and a specific polyalkyl vinyl ether. ;CONSTITUTION: An aqueous bath for electrophoretic lacquering contains a binding agent capable of cathodic deposition and an additive below which enhances the surface appearance. The additive comprises 0.1-3 wt.% of one or several (meth)acrylic copolymers having an amine number of 15-150 and an OH number of 15-450, 0.1-2 wt.% of one or several polyesters containing β-hydroxyalkyl ester group and having an acid number of 0-3 and a wt. average mol.wt. of 1,000-10,000, and/or 0.1-5 wt.% of one or several homopolymers or copolymers, having a wt. average mol.wt. of 500-10,000, of one or several alkyl vinyl ethers having 1-5 carbon atoms in the alkyl residue, wherein wt.% being based on the solids content of the binding agent.;COPYRIGHT: (C)1993,JPO