The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 21, 1981
Filed:
Mar. 31, 1980
Daicel Chemical Industries, Ltd., Osaka, JP;
Abstract
A semipermeable membrane suitable for the use in an artificial kidney of the filtration type is produced by preparing a solution of cellulose acetate in a solvent mixture consisting essentially of a solvent for cellulose acetate and a swelling agent and spreading said solvent on a substrate, the solvent being a mixture of dimethylformamide and acetone, the swelling agent being a mixture of cyclohexanone and water, the ratio by weight of the amount of dimethylformamide and that of acetone to that of the swelling agent being within the area defined by four points consisting of A (60, 20, 20), B (35, 45, 20), C (25, 35, 40) and D (50, 10, 40) in the triangular coordinates represented by FIG. 1; the ratio of cyclohexanone to water being in a range of from 0.8 to 1.3.