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:
Jul. 18, 1989
Filed:
Apr. 22, 1987
Shoji Miyoshi, Osaka, JP;
Ryuichi Nomura, Ashiya, JP;
Toyo Rubber Industry Co., Ltd., Osaka, JP;
Abstract
A process for producing a pneumatic tire having high uniformity with a carcass ply formed of polyester cord, including the steps of: (a) spinning polyester at a tension at the solidifying point of melt polyester between 1.5.times.10.sup.7 and 7.5.times.10.sup.7 dyne/cm.sup.2 ; (b) drawing the polyester into a filament at a draw ration of 2.0 to 3.0; (c) twisting a polyester filament at a twist coefficient of from 800 to 2,500; and then (d) heat treating the filament so that the dimension unstabilizing factor is 8.5 or less. The polyester filament is made of polyester having an ethylene terephthalate component of at least 85 mol % and a high degree of polymerization such that the intrinsic viscosity is at least 0.8, and the ratio of the birefringence of the surface portion to that of the central portion in the polyester filament is from 1.03/1 to 1.15/1; the twist coefficient is represented by T.times..sqroot.D (wherein T is the average value of the numbers of turn of the single twist and final twist per 10 cam of cord, and D is the denier of the cord); and the dimension unstabilizing factor is defined as the sum of the elongation (%) at a load of 2.3 g/d and the thermal shrinkage (%) when heated at 105.degree. V. in dry air for 30 minutes.