Metallocene catalyzed propylene-alpha-olefin random copolymer melt spun fiber

摘要

A fiber product drawn from an isotactic propylene copolymer of a C<Sub>2</Sub>, C<Sub>4</Sub>, C<Sub>5</Sub>, C<Sub>6</Sub>, C<Sub>7</Sub> or C<Sub>8</Sub> ά,ά-olefin monomer produced in the presence of a metallocene catalyst characterized by a bridged chiral and stereorigid cyclopentadienyl or substituted cyclopentadienyl ligand structure of a transitional metal selected from group 4b, 5b, or 6b metals of the Periodic Table of Elements, the copolymer having a MFR less than 35, suitably about 30 or less. The copolymer is heated to a molten state and extruded to form a fiber preform. The preform is subjected to spinning at a spinning speed of at least 300 meters per minutes and subsequent drawing at a speed of up to about 1500 meters per minute to provide a draw ratio of at least 1.5 up to 5:1 to produce a continuous fiber having high tenacity of about 3.5 grams per denier and greater and good hand.