PURPOSE: To obtain a dynamic membrane having a high solute excluding performance and an excellent stability of the membrane due to reflux treatment of an aq. soln. of acid by combining alumina sol with colloidal silica.
CONSTITUTION: Ceramics and sintered matallic powder, etc. can be cited as a porous support. The alumina sol, consisting of particles having 50×5W400× 40μm particle size and a feathery form and using an organic and an inorganic acid such as acetic and hydrochoric acid as a stabilizer, is used. The colloidal silica, consisting of granular particles having 5W50mμ, preferably 10W20mμ, particle size, is used. The concn. of the aq. mixed soln. is regulated to 0.3W1.0g/ lsolid component of silica, and the amt. to about 20W50l per 1m2 surface area of the porous support to manufacture the dynamic membrane.
TATE MASAO
NAKAJIMA KAZUYA
MITSUBISHI KASEI TEKUNO ENGINE