| 摘要 |
PURPOSE: To obtain a high strength and biodegradable polylactoneamide multifilament capable of being biodegraded, improved in strength and toughness, excellent in heat resistance and capable of being supplied to practical uses as a general industrial material. CONSTITUTION: This biodegradable multifilament comprises a polylactoneamide copolymer comprising 5-80wt.% of polyamide units and 20-95wt.% of polylactone units and have a melting point (Tm) of >=90 deg.C and a linear tensile strength of >=4.0d/g. The birefringence of the multifilaments is preferably >=35×10<-3> . The biodegradable multifilaments are produced by a method comprising melt- spinning the polylactoneamide copolymer (relative viscosity of >=0.5), cooling the melt-spun multifilaments in a <=60 deg.C inert gas, subjecting the cooled multifilaments to the first stage drawing treatment in a drawing ratio of 60-85% based on the whole drawing ratio and subsequently subjecting the first drawn multifilaments to the wholly drawing treatment so as to give the multifilaments having a birefringence of >=35×10<-3> after drawn.
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