Patent ID: 8053479
Filing Date: 2011-11-08
Classification: C01B,C09K

Abstract:
1. A silica sol produced by an alkoxide method, wherein said silica sol comprises at least a dispersing agent and silica, wherein said dispersing agent concentration is 10-3000 ppm with respect to the silica, wherein said dispersing agent consists of one or more compounds selected from the group consisting of, (a) inorganic acid selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, phosphorous acid, hypophosphorous acid, alkylphosphate ester, boric acid, pyrophosphoric acid, fluoroboric acid, tetrafluoroborate acid, hexafluorophosphate acid, benzenesulfonic acid and naphthalenesulfonic acid, (b) inorganic acid salt selected from the group consisting of ammonium sulfate, ammonium hydrochloride, ammonium nitrate, monoammonium phosphate, ammonium dihydrogenphosphate and ammonium borate octahydrate, (c) organic acid selected from the group consisting of citric acid, oxalic acid, malic acid, maleic acid, tartaric acid, glutaric acid, adipic acid, pimelic acid, succinic acid, malonic acid, fumaric acid, phthalic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid and lactic acid, and (d) organic acid salt selected from the group consisting of ammonium benzoate, triammonium citrate, ammonium dihydrogen citrate, ammonium oxalate monohydrate, ammonium formate, ammonium salicylate, ammonium adipate, ammonium acetate and tetramethylammonium citrate, wherein said silica sol has a silica concentration of 20 weight % or higher, and said silica sol has a metal impurity concentration of 1 ppm or lower.