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:
May. 17, 1983
Filed:
Jan. 22, 1982
William D Benzinger, Eastown Township, Chester County, PA (US);
Donald N Robinson, Collegeville, PA (US);
Pennwalt Corporation, Philadelphia, PA (US);
Abstract
Vinylidene fluoride polymer ultrafiltration membranes are prepared by casting a sheet of said polymer dissolved in a mixture of a specified solvent and a specified non-solvent, on a smooth substrate, evaporating a portion of the solvent from the sheet, immersing said sheet in a gelation liquid therefore, and optionally, stabilizing the gelled sheet by heat treatment thereof. A porous vinylidene fluoride polymer membrane having smooth, unwrinkled surfaces can be prepared in accordance with the above described process without restraining the membrane during the evaporation and gelation steps by utilizing triethyl phosphate as the solvent.