Diamond Shamrock Corporation

William H Cawley

Edward A Rowe

Edward A Rowe, Jr

A chromium-containing treating composition, which is especially useful for rinsing phosphatized metal surfaces, contains hexavalent chromium-containing compound, methylene chloride and a substance that can be acetamide, N,N-dimethylformamide, acetone oxime and mixtures thereof. The composition is a homogeneous solution that is particularly useful where aqueous systems may create potential water pollution problems.

Chromium containing coating

Metal substrates, and particularly ferrous metal substrates, are now protected by having on their surface composite coatings wherein the base coating comprises a water-insoluble phosphatized coating from an organic phosphatizing composition. Over the phosphatized base coating there is then deposited a topcoating that is typically a paint topcoating. However, a rinse coating, such as a chromic acid solution, may be used on the base coating prior to a paint coating. A highly desirable adherent, corrosion-resistant and water-insoluble composite coating thereby protects the substrate metal.

Phosphatized and painted metal articles

A liquid phosphatizing composition, containing organic solvent such as 1,1,1-trichlorethane or trichlorofluoromethane, can provide phosphate coatings on metal articles. In addition to the organic solvent, the composition contains a phosphatizing proportion of phosphoric acid and a solubilizing liquid capable of solubilizing phosphoric acid in the organic solvent. The composition contains a minor amount of water, yet it is an amount exceeding the proportion of phosphoric acid, and the composition is non-flammable. Phosphatized coatings of desirable water insolubility are obtained.

Non-flammable solvent phosphatizing compositions yielding non water

Topcoat adhesion is now increased for coatings applied over a solvent phosphatized metallic surface. The phosphatized surface is obtained from a composition that can contain methylene chloride, as well as water in minor amount, and yet maintain a continuous and homogeneous liquid phase. By adding significant amounts of stabilizer to the phosphatizing composition, generally by way of an adjuvant composition, the resulting phosphatized coatings will provide for enhanced topcoat adhesion.

Adjuvant composition for solvent phosphatizing solution

A liquid composition, containing methylene chloride, can provide phosphate coatings on metal articles. In addition to the methylene chloride, the composition contains a phosphatizing proportion of phosphoric acid and a solubilizing solvent capable of solubilizing phosphoric acid in methylene chloride. Most critically, the composition contains water in an amount exceeding the proportion of phosphoric acid, yet, the water-containing liquid composition maintains liquid phase homogeneity. Phosphatized coatings of desirable water insolubility are thereby obtained.

Methylene chloride phosphatizing

A liquid composition, containing methylene chloride, can provide phosphate coatings on metal articles. In addition to the methylene chloride, the composition contains a phosphatizing proportion of phosphoric acid and a solubilizing solvent capable of solubilizing phosphoric acid in methylene chloride. Most critically, the composition contains water in an amount exceeding the proportion of phosphoric acid, yet, the water-containing liquid composition maintains liquid phase homogeneity. Phosphatized coatings of desirable water insolubility and unique characteristics are thereby obtained.

Methylene chloride phosphatized coating

Topcoat adhesion is now increased for coatings applied over a solvent phosphatized metallic surface. The phosphatized surface is obtained from a composition that can contain methylene chloride, as well as water in minor amount, and yet maintain a continuous and homogeneous liquid phase. Resulting phosphatized metallic surfaces are often topcoated. By adjusting the constituency of the phosphatizing composition, such as by augmenting the water content, topcoat adhesion can be markedly enhanced.

Increasing topcoat adhesion for solvent phosphatized surfaces

A liquid phosphatizing composition, containing organic solvent such as 1,1,1-trichlorethane or trichlorofluoromethane, can provide phosphate coatings on metal articles. In addition to the organic solvent, the composition contains a phosphatizing proportion of phosphoric acid and a solubilizing liquid capable of solubilizing phosphoric acid in the organic solvent. Most critically, the composition contains water in an amount exceeding the proportion of phosphoric acid, yet, the water-containing liquid composition maintains liquid phase homogeneity. Phosphatized coatings of desirable water insolubility are obtained.

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Painesville, OH, United States of America

William H Cawley