Water-based coating composition capable of forming nitrogen oxide decomposing coating film

TLDR: In this article, the problem of obtaining a coating material which can form a coating film which is not deteriorated by the oxidation action of the constituent powder and is excellent in oxidation resistance, weathering resistance, chemical resistance, long-term use resistance, staining resistance and the property of decomposing nitrogen oxides by dispersing at least one photocatalytically active powder selected among titanium dioxide and zinc oxide powders in a water-soluble silicate coating binder is addressed.

Abstract: PROBLEM TO BE SOLVED: To obtain a coating material which can form a coating film which is not deteriorated by the oxidation action of the constituent powder and is excellent in oxidation resistance, weathering resistance, chemical resistance, long-term use resistance, staining resistance and the property of decomposing nitrogen oxides by dispersing at least one photocatalytically active powder selected among titanium dioxide and zinc oxide powders in a water-soluble silicate coating binder. SOLUTION: The water-soluble silicate coating binder mainly consists of a water-soluble silicate (a) and a curing agent (b). Components (a) is exemplified by a modified water-soluble silicate obtained by reacting an alkali metal silicate (1) and an oxide and/or a hydroxide (2) of a metal selected among aluminum, a group IIA metal and a transition metal with a water-soluble silicate material (A) represented by the formula: M 2 O.xSiO 2 .yH 2 O (wherein M is a group IA alkali metal, N(CH 2 OH) 4 or the like; and x and y are each a positive number). The curing agent (b) is exemplified by a product among phosphoric acid, a condensed phosphate, a water-soluble silicate material (B) of the formula: M 2 O.xSiO 2 .y'H 2 O (wherein y' is a positive number or 0) with a condensed phosphate. COPYRIGHT: (C)1998,JPO