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:
Jun. 04, 1985
Filed:
Jan. 25, 1984
Kureha Kagaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Abstract
A composite fiber comprises at least a two layer structure of a sheath and a core, each layer comprising a vinylidene fluoride resin, the core portion having an inherent viscosity of 1.10 dl/g and the sheath portion having an apparent viscosity lower than that of the core portion, said composite fiber having a birefringence of at least 36.0.times.10.sup.-3. This composite fiber, which has excellent knot strength (as high as 91 kg/mm.sup.2), high tensile strength (as high as 103 kg/mm.sup.2), excellent luster, and high processability and productivity, is produced by preparing a composite comprising a core portion of a vinylidene fluoride resin having an inherent viscosity of at least 1.10 dl/g and at least one layer of a sheath portion covering over said core portion, which has an apparent viscosity lower than that of the vinylidene fluoride resin of the core, while at least one of the core portion and the sheath portion is in molten state, and then subjecting the composite to at least one-step stretching to a stretching degree of 5.0-fold or more at a temperature which is lower by 5.degree. C. or more but not lower by 30.degree. C. or more than the melting point of the resin of the core.