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:
Jun. 29, 1999
Filed:
Jan. 16, 1997
Meng-Jiao Wang, Lexington, MA (US);
Trevor Alan Brown, Groton, MA (US);
Ralph E Dickinson, Dracut, MA (US);
Cabot Corporation, Boston, MA (US);
Abstract
In a multi-stage process for producing a substantially unvulcanized elastomer composition, a masterbatch is produced by thermomechanical working in a first or other early stage of the multi-stage process. The masterbatch comprises sulfur crosslinkable hydrocarbon elastomer in which is substantially dispersed, particulate fillers, for example carbon black or silicon-treated carbon black, modified carbon black and/or silica and sulfur crosslinking agent effective to crosslink the hydrocarbon elastomer and selected from sulfur donors and sulfur. The filler and sulfur crosslinking agent can be mixed together as a pre-blend prior to being added to the elastomer. The substantially unvulcanized elastomer is then produced in one or more later stages of the multi-stage process, involving further theromechanical working of the masterbatch. A curative additive comprising accelerator, and optionally additional sulfur crosslinking agent, is added and dispersed in the elastomer in the last stage of the multistage process. In accordance with another aspect, oil is added to the elastomer subsequent to addition and substantial dispersion of the filler and sulfur crosslinking agent. The substantially unvulcanized elastomer composition can be cured or vulcanized to form tire tread and other commercial products. Significant improvement in performance characteristics is achieved by preferred embodiments, including good abrasion resistance and low hysteresis measured, for example, as tan .delta..sub.max at 70.degree. C.