摘要 |
Fibers melt-spun from a thermoplastic alternating copolymer composed of alkenes and carbon monoxide have a tenacity BT>900 mN/tex, melting point Tm>220° C., crystallinity Vc>33%, and birefringence DELTAn>0.0550. These fibers are prepared by melt-spinning the copolymer and then drawing the resulting fibers, the spinning process being conducted using a polymer melt free of crystallization nuclei at a temperature of at most 40 K above the melting temperature of the polymer Tm(in K) and the drawing of the fibers being conducted at a temperature in the range of Tmc-15 K to Tmc-90 K, with Tmc representing the constrained melting temperature, at a draw ratio in the range of 5 to 12 and a drawing tension corrected for temperature DTd.corr. in the range of 105 to 300 mN/tex. The fibers are pre-eminently suitable for use as reinforcing yarn in rubber articles such as car tires. |