| 摘要 |
PROBLEM TO BE SOLVED: To obtain a cord suitable as a reinforcing material by twisting multifilaments of a core-sheath type conjugate fiber composed of a core zone and a sheath zone having specific relative viscosity difference together. SOLUTION: A polyester polymer is melt-spun at 1,600 to 6,000 m/min and cooled and as necessary stretched in a continuous process to provide the objective industrial polyester multifilaments having 0.003-0.100 relative viscosity difference between a core zone and sheath zone, at least 70 dtex linear density, 15 filaments, >=500, preferably 700-1,000 mN/tex strength at 160 deg.C, 375-600 mN/ tex 5% LASE ratio, >=0.5% and <3.7 dry heat shrinkage, 1,700 to 2,200 average relative viscosity of spun yarn filament and 50-20% breaking elongation. The multifilaments are twisted together to form dtex 1100(Z393)×2(S393) type cord and subjected to two step immersion treatment for improvement of tackiness to provide the objective cord. |
