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:
May. 19, 1992
Filed:
Apr. 19, 1990
Toshiya Mizuno, Tsuchiura, JP;
Yoshikichi Teramoto, Tsuchiura, JP;
Takeshi Saito, Tsuchiura, JP;
Juichi Wakabayashi, Ibaraki, JP;
Kureha Kagaku Kogyo, , JP;
Abstract
A poly(arylene sulfide) sheet excellent in planarity and smoothness is formed of a composition composed at least principally of a substantially linear, high molecular poly(arylene sulfide) having a melt viscosity of at least 1,000 poises. It has an elongation at break of at least 10% at 23.degree. C. and a Young's modulus of at least 5 kg/mm.sup.2 at 200.degree. C., and per area of 1 cm.times.2 cm on at least one of its surfaces, contains not more than 1 convex or concave whose angle of elevation or depression is at least 2.degree. and whose height or depth is at least 10 .mu.m. The sheet is produced by melting the composition, extruding the melt through a slit die, cooling and solidifying the extrudate into a sheet, preheating the sheet for 3-100 seconds in a temperature range of from a temperature 20.degree. C. lower than the glass transition temperature of the polymer to a temperature 25.degree. C. higher than the glass transition temperature, and then causing the thus-preheated sheet to pass between a heating roll heated at a temperature in a range of 120.degree.-200.degree. C. and a pinch roll under a pinch pressure of 0.05-10 kg/cm, whereby the sheet is continuously pressed under linear pressure, is subjected to a heat treatmtent for 3-100 seconds and is crystallized.