Polyvinylidene fluoride filaments
AssigneeKureha Kagaku Kogyo Kabushiki Kaisha
InventorsHiroyuki Endo, Hirosi Ohhira, Tohru Sasaki
Life of this patent
Estimating the term…
Abstract
An improved polyvinylidene fluoride resin-made filament. It consists substantially of a blend of 99-wt. % of a first polyvinylidene fluoride resin component having an inherent viscosity higher than 1.30 dl/g on the one hand, and 1-60 wt. % of a second polyvinylidene fluoride component having an inherent viscosity lower than 1.20 dl/g on the other. The blend has a critical shearing stress lower than 2.8.times.10 dyne/cm.sup.2 and is subjected to melt-spinning and successively to a primary and a secondary stretching in a temperature region of 70.degree.-180.degree. C. The overall stretch factor is selected to be 4-10.
Claims7
Polyvinylidene fluoride filament comprising a blend at 99-40 wt. % of a first polyvinylidene fluoride component having an inherent viscosity higher than 1.30 dl/g and 1-60 wt.% of a second polyvnylidene fluoride component having an inherent viscosity lower than 1.20 dl/g, said blend having a critical shearing stress lower than 2.8.times.10.sup.4 dyne/cm.sup.2 and subjected to melt-spinning and successively to a primary and a secondary stretching at 70.degree.-180.degree. C., the overall stretch factor being selected to 4-10.
A process for making polyvinylidene fluoride filaments comprising the steps of blending a 40-99 wt. % of a first polymer selected from the group consisting of polyvinylidene fluoride homopolymers, and copolymers of polyvinylidene fluoride, wherein such copolymer has as its major component vinylidene fluoride, said first polymer having an inherent viscosity higher than 1.30 dl/g, and 1-60 wt. % of a second polymer selected from the group consisting essentially of polyvinylidene fluoride homopolymers, and copolymers of polyvinylidene fluoride, wherein such copolymer has as its major component vinylidene fluoride, 40-99 wt. %, said second polymer having an inherent viscosity lower than 1.20 dl/g, said blend having a critical shearing stress less than 2.8.times.10.sup.4 dyne/cm.sup.2 ;
- melt-spinning said blend;
- and successively subjecting said melt-spun blend to primary and secondary stretching at temperatures between about 70.degree.-180.degree. C., the overall stretch factor being selected to be between about 4-10.
Dependencies are inferred from the claim text.