To obtain an antifogging agent with high storage stability, exhibiting high antifogging effect from just after being applied, and improved in antifogging sustainability by making the agent include water, a water-soluble cellulose and a specific colloidal silica and by bringing the alkali component concentration of the agent to a specified level.
This antifogging agent is obtained by including (A) 98.0-99.8 wt.% of water, (B) 0.01-0.40 wt.% of a water-soluble cellulose, and (C) 0.16-1.99 wt.% of colloidal silica with an average particle size of 3-50 (pref. 5-30) nm and by bringing the alkali component concentration of the agent to ≤50 ppm, pref. ≤10 ppm, more pref. ≤8 ppm; where the viscosity of the component B (at 25°C, in the form of a 5% aqueous solution) is pref. 1,000-100,000 cPs, and the component B is e.g. methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, carboxymethylcellulose, hydroxyethylmethyl cellulose.
NAKADA YUTAKA
ICHIBA SHIGERU
