ELASTIC POLYURETHANE YARN AND METHOD OF MANUFACTURING THE SAME

• Main Authors: KAWATA, TERUYOSHI, TOKUTOMI, SHIGERU, NAKAI, YASUSHI, YOSHIMOTO, KIYOSHI, YAMAKAWA, YUKIO
• Format: Patent
• Language: English; French; German
• Published: 31.03.1999
• Edition: 6
• Subjects: APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBONFILAMENTS; CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS,THREADS, FIBRES, BRISTLES OR RIBBONS; CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, ORYARNS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; MECHANICAL FINISHING OF YARNS OR ROPES; NATURAL OR ARTIFICIAL THREADS OR FIBRES; SPINNING; TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TEXTILES; WARPING OR BEAMING; YARNS; YARNS OR THREADS

The present invention relates to melt-spun polyurethane elastic fiber having a degree of luster of 70 or less, the degree of luster being defined as (I/Io)x100 where the amount of light reflecting off the surface of the fiber is I and the amount of light reflecting off a standard white plate is Io. On the surface of preferable polyurethane elastic fiber, 10 or more mountain-like protrusions of 0.2 to 5.0 mu m in height are present every 10 mu m fiber in the axial direction. Also, the present invention relates to a process for producing polyurethane elastic fiber, comprising melt-spinning butylene terephthalate-based crystalline polyester (A) and thermoplastic polyurethane (B) wherein before spinning, the compound (A) is melt-mixed with thermoplastic polyurethane (B-1) having isocyanate groups in an amount of 150 to 500 mu mol/g. Further, the present invention relates to covered fiber comprising the polyurethane elastic fiber as a core. Even if stockings, tights, sox etc. are produced using the covered fiber of the present invention, the luster phenomenon as the drawback of particularly melted spun urethane does not occur, so it is possible to obtain products with excellent appearance.