| 摘要 |
1,163,120. Electro-painting. SCM CORP. Nov.23, 1966 [Dec.2, 1965], No.52525/66. Heading C7B. In a process for painting metal, e.g. steel or galvanized iron or steel, a paint composition containing acidic resin is electro-deposited from an aqueous dispersion containing substantially no metal treating oxyanion solute such that the metal is at least partially coated with a curable resinous film, and the coated metal is thereafter subjected to direct current anodic electrolysis using as electrolyte an aqueous dispersion containing at least one oxyanion of phosphorous, boron, arsenic, silicon, an amphoteric metal, or the oxalate anion or mixtures thereof, and which may also contain dispersed therein anodically-depositable organic coating material, e.g. the coating material deposited on the metal during the first deposition step. Oxyanions which may be used include phosphate, chromate, dichromate, borate, molybdate, tungstate, vanadate, fluosilicate, titanate, manganate, columbate, zirconate, hafnate, silicate, zincate, plumbate, cadmate, aluminate, arsenate, antimonate, bismuthate, stanuate, arseno-molybdate, phospho-vanadate, phosphomolybdate and phospho-tungstate. The paint composition of the first step may include pigment or mineral filler material, and the resin used may be a poly carboxylic resin at least partially neutralized with a basic amine compound or ammonia, e.g. a resin derived from maleic anhydride, acrylic acid or methacrylic acid. The resultant composite film may be air cured or may be cured by ionizing radiation or by treatment with a material which will cross-link with or otherwise set the resin deposit, e.g. a polyepoxy compound, a polymerizable ethylenically unsaturated material such as divinyl benzene, an alum solution or a metal salt solution reactive with carboxylic acid groups. Prior to treatment the metal may be cleaned using an organic solvent, e.g. trichloroethylen, eaustic soda or electrolytically using a caustic electrolyte.
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