Abstract: A coating composition for coating a metal plate, and containing (i) 100 parts by weight of a polyester-melamine resin composed of (a) a polyester resin having a glass transition temperature of 5.degree. to 40.degree. C. and a number average molecular weight of 15,000 to 30,000 and (b) a melamine resin at a weight ratio (a)/(b) of 75/25 to 55/45 and (ii) 1 to 2 parts by weight of an amine-blocked derivative of a long-chain alkylbenzenesulfonic acid.

Abstract: A one-can heat-curable resin composition which comprises: (1) a polyester polyol having at least three functional groups; (2) an adduct of an epoxy resin with at least one member selected from the group consisting of an alkanol amine and a monovalent phenol; and (3) a blocked organic polyisocyanate or a blocked prepolymer having terminal NCO groups obtained by reaction of an organic polyisocyanate with an active hydrogen-containing compound, when used in the production of precoated metal, gives good coated plates, which can be advantageously used in manufacturing household electric appliances and so on.

Abstract: Paint coated metal sheets are provided by applying a paint film on a metal sheet wherein the paint film has a surface layer having a thickness of one-5000 angstroms. The paint film contains fluorine atoms and/or perfluoralkyl groups such as methyl fluoride, ethyl fluoride, the fluorine atoms and/or perfluoralkyl groups being introduced in the paint film by a plasma treatment.

Abstract: A one-can thermosetting resin composition comprising (A) a blocked product of hexamethylene diisocyanate or bis(isocyanatomethyl)cyclohexane, or a blocked product of an adduct of hexamethylene diisocyanate or bis(isocyanatomethyl)cyclohexane and (B) a polyester polyol having at least three functional groups, gives tough coating films in yellowing and thermal degradation, and also exhibits increased hardness as well as high flexibility, stain resistance and chemical resistance. Especially, when the resin composition is used for preparing precoated metals, it gives good steel plates, thus being advantageously utilized for, among others, light electric appliances.

Abstract: A one-can thermosetting resin composition comprising (1) a polyester polyol obtained by allowing an aliphatic dicarboxylic acid to react with an aliphatic glycol and polyol having at least three functional groups and (2) a blocked product of .alpha.,.alpha.,.alpha.'.alpha.'-tetramethyl-xylylene diisocyanate or 4,4'-methylene bis (cyclohexyl isocyanate), or a blocked product of an NCO-terminated prepolymer obtained by allowing .alpha.,.alpha.,.alpha.'.alpha.'-tetramethylxylylene diisocyanate and/or 4,4'-methylene bis(cyclohexylisocyanate) to react with an active hydrogen compound, gives tough coating films in yellowing and thermal degradation, and also exhibits increased hardness as well as high flexibility, stain resistance and chemical resistance. Especially, when the resin composition is used for preparing precoated metals, it gives good steel plates, thus being advantageously utilized for, among others, light electric appliances.

Abstract: A one-can heat-curable resin composition which comprises: (1) a polyester polyol having at least three functional groups; (2) an adduct of an epoxy resin having at least one secondary hydroxyl group with a lactone compound or an alkylene oxide; and (3) a blocked organic polyisocyanate or a product of blocking of a prepolymer having terminal NCO groups obtained by reacting an organic polyisocyanate and an active hydrogen-containing compound, gives a tough and durable coat film showing no yellowing or thermal degradation due to heating at all.Furthermore, said film has a high hardness and is excellent in processability and staining resistance, particularly in mustard staining resistance. In particular, the composition, when used in the production of precoated metal, gives good coated steel sheets, which can be advantageously used in manufacturing household electric appliances and so on.

Abstract: The paint composition for under coating of the present invention comprises 60 to 90% by weight of an epoxy polyol resin optionally together with a hardener therefor and 10 to 40% by weight of silica particles. Said epoxy polyol resin is obtained by reacting an optionally substituted glycidyl-etherified product of an alkylene oxide adduct of a dihydric phenol with a phosphorus acid having at least one P--OH bond, an ester or a salt thereof to thereby give a precondensate, reacting said precondensate with a dihydric phenol to give an epoxy resin of a high molecular weight, and further reacting said epoxy resin with a compound having an amino group capable of reacting with an epoxy group. Said silica particles comprise a primary particle having an average particle size of 1 to 10 m.mu., a surface area of 270 m.sup.2 /g or above and a concentration of silanol groups on the particle surface of 0.25 mM/100 m.sup.2 or above.

Abstract: A weldable steel plate plated with zinc, a zinc base alloy or zinc composite and coated on the plating with a coating material comprising a mixture of at least one type of ferrous alloy powder with an oxygen concentration of 1.0% by weight or less and zinc dust, is provided, and the weldable coated steel plate also has good workability, coherence, weldability and corrosion resistance.

Abstract: A weldable paint-coated steel sheet having improved corrosion resistance, weldability and workability, comprising a zinc alloy coated steel substrate and a paint coating applied thereon, said paint coating containing zinc alloy powder and at least one of the groups consisting of zinc powder and hard electric conductive powder.

Abstract: A precoated steel sheet and a process for production thereof is provided which comprises coating a resin composition comprising mainly an acryloxyloxy- or methacryloyloxy-terminated polyester on the surface of a steel sheet, said acryloyloxy- or methacryloyloxy-terminated polyester being prepared by reacting a hydroxy-terminated polyester comprising (a) a dicarboxylic acid unit containing about 10 to about 80 mol % of a terephthalic acid unit and (b) dihydric alcohol unit containing about 30 mol % or more of a dihydric alcohol unit containing 3 or more carbon atoms, and having a number average molecular weight of about 400 to about 5,000, with acrylic acid or methacrylic acid, and curing the thus-coated resin composition by irradiating the sheet with an electron beam.

Abstract: A coating composition for a metal substrate having excellent adhesion, corrosion resistance and welding property which comprises (A) an epoxy resin, (B) an organic phosphorus compound, (C) zinc powder, of which a portion being replaceable by (E) a solid electroconductive material, and (D) a magnesium compound dispersed in a liquid medium, the weight proportion of the components (A) and (B) being from 45:55 to 95:5, the content of the component (C) corresponding to from 30 to 95% by weight based on the total weight of the non-volatile components in the composition and the content of the component (D) being from 0.1 to 5% by weight based on the total weight of the non-volatile components in the composition.

Abstract: Electroplating in an acidic zinc-nickel alloy plating bath containing vanadium ions as a third component provides a plating having a surprisingly high level of corrosion resistance equal to about 10 times that of pure zinc.

Abstract: A weldable coated steel sheet comprising a steel sheet substrate and a paint coating layer thereon, said paint comprising at least one of the group consisting essentially of titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, niobium carbide, tantalum carbide, and chromium carbide in the powder form.

Abstract: A method for electroplating a metal strip to be plated includes continuously running the metal strip through the interior of a plating vessel of a cylindrical form having a rectangular cross section, the upper and lower walls of such vessel being constructed of an insoluble anode material which is to function as an anode, and compulsively circulating a plating solution in a direction counter to the running direction of the metal strip within the plating vessel and an apparatus for carrying out the same, whereby a high speed plating is performed and the replacement of the anodes can be minimized.

Abstract: An aqueous solution for treatment of metal surfaces which has a pH value greater than 7, and comprises no free inorganic acid and 0.1 to 10% by weight, estimated as Cr, of a chromium compound in which 5 to 40% of the initial quantity of Cr(VI) is reduced by a reaction with a trifunctional phenol.