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. 02, 1999
Filed:
Nov. 05, 1996
Ryuji Izumoto, Tokyo, JP;
Teruo Miura, Tokyo, JP;
Koshiro Monji, Tokyo, JP;
Shinichi Iwasaki, Tokyo, JP;
Kentaro Fujino, Tokyo, JP;
Masayuki Ohashi, Tokyo, JP;
Bridgestone Corporation, Tokyo, JP;
Abstract
A fiber composite material in which short fibers, such as polyester short fibers, are added to a matrix, such as a cross-linked rubber matrix, is provided, wherein a heat shrinkage ratio of the short fibers is 8% or less at fiber composite material molding temperatures of 140 to 200.degree. C. Also provided is a pneumatic tire in whose tire tread the fiber composite material is used. Such pneumatic tires include pneumatic tires provided with a foamed rubber layer in a tire tread. The foamed rubber layer has an average cell diameter of 10 to 120 .mu.m and an expansion ratio of 3 to 50%. A solid phase rubber portion of the foamed rubber layer includes 5 to 55 parts by weight of carbon black, 55 to 5 parts by weight of silica, and 1 to 15 parts by weight of short fibers to 100 parts by weight of a diene-base rubber component including 70 to 20 parts by weight of natural rubber and 30 to 80 parts by weight of polybutadiene rubber. A surface of the tire tread has a hardness of 52 or less at 0.degree. C. The short fibers have a length which is from 0.5 to 3 mm and which is shorter than a minimum gap between sipes of a tire surface, a diameter of 30 to 100 .mu.m, an aspect ratio of 5 to 100, and a heat shrinkage ratio of 8% or less at 140 to 200.degree. C. On-ice performance of the pneumatic tire of the present invention is excellent.