Surface treatment chemical for forming a hydrophilic coating
AssigneeNippon Paint Co., Ltd.
InventorKatsuyoshi Yamasoe
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Abstract
An aqueous surface treatment composition for forming a hydrophilic coating comprising: (a) alkali metal silicate, (b) aminoalcohol, and (c) a water-soluble resin selected from the group consisting of a water-soluble nylon, a natural polysaccharide and a water-soluble, natural protein, and/or a water-soluble silane coupling agent. This aqueous surface treatment composition is used to form a hydrophilic coating on an aluminum surface having a corrosion-resistant coating layer. The hydrophilic coating prepared from this compositon has good hydrophilic nature and corrosion resistance with substantially no unacceptable odor.
Claims7
A method of treating an aluminum surface comprising the steps of:
- (A) forming a phosphoric chromate or chromium chromate coating on said aluminum surface, and
- (B) treating it with an aqueous surface treatment composition comprising
- (i) alkali metal silicate,
- (ii) at least about 0.5% aminoalcohol, and
- (a) a water-soluble resin selected from the group consisting of nylon, a natural polysaccharide and a natural protein;
- (b) a water-soluble silane coupling agent;
- or mixtures of said silane with anyone of the aforesaid resins;
- (c) wherein said alkali metal silicate has a SiO.sub.2 /M.sub.2 O molar ratio of 0.5-3 and the concentration of SiO.sub.2 is 0.1-1.0 weight %.
Dependencies are inferred from the claim text.