Patent ID: 6478860
Filing Date: 2002-11-12
Classification: C23C

Abstract:
A liquid composition for conditioning metal surfaces prior to phosphate conversion coating treatment thereof, said liquid composition containing an aqueous dispersion comprising the following components:(A) a stably dispersed, undissolved solid powder component that is constituted of phosphates that contain at least one divalent or trivalent metal, the solid powder thereof having a particle size of not more than 5 &mgr;m; and (B) an accelerant component selected from the group consisting of the following subgroups: (1) monosaccharides, polysaccharides and derivatives thereof; (2) orthophosphoric acid, condensed phosphoric acids, and organophosphonic acid compounds; (3) water-soluble polymers that are homopolymers or copolymers of vinyl acetate and derivatives of these homopolymers and copolymers; and (4) copolymers and polymers as afforded by the polymerization of, (a) at least one selection from: (i) monomers, exclusive of vinyl acetate, that conform to general chemical formula (1): â€ƒwhere R1=H or CH3 and R2=H, C1 to C5 alkyl, or C1 to C5 hydroxyalkyl; and (ii) other &agr;,&bgr;-unsaturated carboxylic acid monomers; and, optionally, (b) not more than 50% by weight of monomers that are not vinyl acetate and are not within the description of part (a) immediately above but are copolymerizable with said monomers that are within the description of said part (a).