| 摘要 |
PROBLEM TO BE SOLVED: To provide a filter for a duct which catches particulate matter, and its manufacturing method, and provide a biodegradable filter for a duct. SOLUTION: The filter for the duct is made by impregnating a cloth made of natural fibers with a noncombustible liquid. An aqueous film-forming inorganic compound is used as the noncombutible liquid. The compound is made by causing a thick solution reaction of metallic aluminum or metallic silicon with an alkali metal in water or an aqueous solution of a mineral acid compound such as borax, boric acid, sodium fluoride or hydrofluoric acid dissociating boric acid or hydorfluoric acid by hydration, further reacting them with the mineral acid compound and controlling reaction heat within the range of≥50°C and≤100°C. The alkali metal is causatic potash, causatic soda or causatic lithium. The product film having a specific gravity of 1.1 or more is produced by using the compound. COPYRIGHT: (C)2006,JPO&NCIPI
|
