The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 29, 1977
Filed:
Jan. 05, 1976
Teijin Limited, Osaka, JA;
Abstract
Naphthalate polyester filaments, yarns or fibers consisting essentially of a naphthalate polyester which has an intrinsic viscosity of 0.3 to 3.5 and a softening point of at least 200.degree. C, and in which at least 85 mol% of the total recurring units consist of units of the formula ##STR1## wherein n is 4 or 6, and having at least one diffraction peak at a Bragg scattering angle 2.theta. = 16.3.degree. -- 16.7.degree. and/or 2.theta. = 25.3.degree. - 25.8.degree. in their X-ray diffraction. These filaments, yarns or fibers are useful especially as an electrically insulating material, an elastomeric reinforcing material, a fluid filter material, a paper-making canvas and a fastener component material. Of these, filaments, yarns or fibers of poly(tetramethylene 2,6-naphthalate) are prepared by melt-spinning the polymer thereby to form undrawn filaments having a birefringence of at lest 0.01 and a density of not more than 1.300, drawing the undrawn filaments in at least one step at a temperature of at least 60.degree. C. at a total draw ratio of at least 1.8, and then heat-treating the drawn filaments at a temperature higher than the temperature employed in the drawing step and within a range of 100.degree. to 240.degree. C. at constant length, under a restricted shrinkage of not more than 15%, or under a stretch of not more than 15%.