Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises: trivalent chromium and oxalic acid in a molar ratio ranging from 0.5/1 to 1.5/1, wherein the trivalent chromium is present in the form of water-soluble complex with oxalic acid; and cobalt ions, which do not form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation; wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises: trivalent chromium and oxalic acid in a molar ratio ranging from 0.5/1 to 1.5/1, wherein the trivalent chromium is present in the form of water-soluble complex with oxalic acid; and cobalt ions, which do not form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation; wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises: trivalent chromium and oxalic acid in a molar ratio ranging from 0.5/1 to 1.5/1, wherein the trivalent chromium is present in the form of a water-soluble complex with oxalic acid; and cobalt ions, which do not form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation; wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises: trivalent chromium and oxalic acid in a molar ratio ranging from 0.5/1 to 1.5/1, wherein the trivalent chromium is present in the form of a water-soluble complex with oxalic acid; and cobalt ions, which do not form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation; wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises: trivalent chromium and oxalic acid in a molar ratio ranging from 0.5/1 to 1.5/1, wherein the trivalent chromium is present in the form of a water-soluble complex with oxalic acid; and cobalt ions, which do not form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation; wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises a silicon compound; trivalent chromium and oxalic acid in a molar ratio ranging from 0.5 to 1.5, wherein the trivalent chromium is present in the form of a water-soluble complex with oxalic acid; and cobalt ions, which form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation, wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating. This solution can provide a corrosion resistant trivalent chromate conversion film excellent in the corrosion resistance after heating.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises: trivalent chromium and oxalic acid in a molar ratio ranging from 0.5/1 to 1.5/1, wherein the trivalent chromium is present in the form of a water-soluble complex with oxalic acid; and cobalt ions, which do not form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation; wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating.

Abstract: A processing solution for forming a hexavalent chromium free, corrosion resistant trivalent chromate conversion film on zinc or zinc alloy plating layers comprises a silicon compound; trivalent chromium and oxalic acid in a molar ratio ranging from 0.5 to 1.5, wherein the trivalent chromium is present in the form of a water-soluble complex with oxalic acid; and cobalt ions, which form a hardly soluble metal salt with oxalic acid and are stably present in the processing solution without causing any precipitation, wherein the solution reacts with zinc when bringing it into contact with the zinc or zinc alloy plating to form a hexavalent chromium free, corrosion resistant, trivalent chromate conversion film containing zinc, chromium, cobalt, oxalic acid and silicon on the plating. This solution can provide a corrosion resistant trivalent chromate conversion film excellent in the corrosion resistance after heating.

Abstract: The invention relates to an acid tin-silver alloy plating bath which comprises tin ions, silver ions, one compound selected from the group consisting of aromatic thiol compounds and aromatic sulfide compounds, substantially non-cyanide and a balance of water, the pH of the bath being not higher than 2. According to this acid bath, tin and silver can be kept dissolved in the bath in a stable state for a long period of time even at a high temperature and a predetermined plating capacity is kept for a long period of time even though the bath is free from cyanide.

Abstract: A deterring solvent essentially consists of (A) a brominated hydrocarbon of the formula: C.sub.n H.sub.2n+1 Br wherein n represents a number of 3 or above and/or a brominated hydrocarbon of the formula: C.sub.m H.sub.2m-1 Br wherein m represents a number of 2 or above. A deterging solvent composition comprises the above-described solvent (A) and a stabilizer selected from the group consisting of nitroalkanes, ethers, epoxides and amines. These solvent and solvent composition have an excellent deterging effect and usable as a substitute for the flon and chlorine solvents. Furthermore, the deterging solvent composition has a high stability.

Abstract: A zinc-iron-phosphorus alloy-plating bath having a pH of not less than 13 and containing iron, phosphorus and zinc sources in amounts required for electro-depositing a zinc-iron-phosphorus alloy film having an iron content ranging from 0.1 to 30% by weight, a phosphorus content ranging from 0.001 to 1.5% by weight and the balance of zinc, and an auxiliary agent for depositing phosphorus. The use of the alkaline plating bath permits the formation of a zinc-iron-phosphorus alloy film, through plating, excellent in lustre of deposit, throwing power and corrosion resistance and the reduction in corrosion of the plating equipment and also permits the formation of a film, through plating, having excellent adhesion as an undercoat for painting.

Abstract: A zinc-cobalt alloy-plating alkaline bath comprises a zinc compound, a cobalt compound, an alkali hydroxide and a reaction product of an alkyleneamine with an alkylene oxide and having a pH of not less than 13 and a method for forming a zinc-cobalt alloy plating film comprises the step of forming, on a substrate, a zinc-cobalt alloy plating film having a cobalt content ranging from 0.05 to 20% by weight and a zinc content ranging from 80 to 99.95 % by weight, while using the foregoing alkaline plating bath. The Zn-Co alloy-plating bath permits the achievement of a desired rate of Co-eutectoid even when a small amount of a chelating agent is incorporated into the bath and therefore, the bath is excellent in the disposability of waste water.

Abstract: A deterging solvent essentially consists of (A) a brominated hydrocarbon of the formula: C.sub.n H.sub.2n+1 Br wherein n represents a number of 3 or above and/or a brominated hydrocarbon of the formula: C.sub.m H.sub.2m-1 Br wherein m represents a number of 2 or above. A deterging solvent composition comprises the above-described solvent (A) and a stabilizer selected from the group consisting of nitroalkanes, ethers, epoxides and amines. These solvent and solvent composition have an excellent deterging effect and usable as a substitute for the flon and chlorine solvents. Furthermore, the deterging solvent composition has a high stability.

Abstract: The invention provides an electroplating bath for forming a zinc-nickel alloy coating consisting essentially of water, about 1 to 70 grams/liter of zinc, about 0.6 to 118 grams per liter of nickel, at least one compound from the group consisting of (i) aliphatic amines in an amount not more than 16 grams/liter, (ii) polymers of aliphatic amines in an amount not more than about 20 grams per liter and (iii) a compound selected from the group consisting of hydroxyaliphatic carboxylic acids and salts thereof in an amount from 0 to 2 mols/liter, said bath having a pH of more than 11. The invention also provides an electroplating method for forming a chromate coating on a zinc-nickel alloy coating electrolytically deposited from the electroplating bath defined in the preceding sentence on electrically conductive metalics matrix material, and forming a chromate coating on the zinc-nickel alloy coating by means of a chromate treatment.