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:
Jan. 04, 1977
Filed:
Nov. 26, 1974
Luigi Patron, Venice, IT;
Pier Luigi Mazzuco, Favar Veneto (Venice), IT;
Favato Veneto, Mestre, IT;
Enzo Trevisan, Mestre (Venice), IT;
Ennio Niero, Mirano (Venice), IT;
Montefibre S.p.A., Milan, IT;
Abstract
An improved process for the wet-spinning of acrylic polymers is disclosed, wherein a spinning solution of an acrylic polymer in an organic solvent, such as dimethylacetamide or dimethylformamide, is extruded through a spinneret into a coagulating bath consisting essentially of water and an organic solvent in a ratio between 30:70 and 60:40 by weight, and wherein the filaments thus obtained are washed, stretched and heat treated, and wherein the coagulating bath contains from 0.03% to 3% by weight of acid corresponding to said organic solvent and has a pH value greater than 5, and preferably between 6.5 and 8. The spinning solvent is preferably dimethylacetamide containing free acetic acid to an extent of less than 0.1% by weight, the acetic acid if necessary being added to the coagulating bath to bring its concentration up to values between 0.03% and 3% by weight. The pH value greater than 5 is obtained by the addition to the coagulating bath of ammonium hydroxide, an alkali metal hydroxide, or dimethylamine.