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:
Dec. 06, 1977
Filed:
Oct. 10, 1975
Robert Alden Lofquist, Richmond, VA (US);
John Christopher Haylock, Midlothian, VA (US);
Allied Chemical Corporation, Morris Township, NJ (US);
Abstract
It has been suggested that a high strength polycaproamide fiber having excess number of carboxyl end groups over amino end groups can be produced by melt spinning a polymer prepared by polymerizing e-caprolactam and reacting the polymer with a dibasic carboxylic acid containing at least six carbon atoms. However, with incorporation of this dicarboxylic acid reactant in continuous operation, serious problems have been encountered in melt-spinning of the polymer due to the frequent occurrence of 'nubs' or enlarged places in the extruded polyamide filament. It has now been found that the occurrence of said nubs in the fiber can be greatly reduced by utilizing certain cyclic tetracarboxylic acid dianhydrides and reacting the dianhydride at the end of the polymerization. Moreover, dyeing properties of the fiber may be more readily controlled.