The rubber constituent null which improves resistance katsuto Characteristic and resistance chitsupingu Characteristic

摘要

PURPOSE:To obtain the titled composition suitable for tire tread use, by incorporating a base rubber with specified amount of petroleum resin of specific structure prepared from copolymerization of cyclopentadiene and/or dicyclopentadiene in specific proportion. CONSTITUTION:The objective composition can be obtained by incorporating 100pts. by wt. of at least one sort of rubber selected from natural rubber and diene-based synthetic rubbers (e.g., styrene butadiene rubber) with (A) 1-30(pref. 3-15)pts. by wt. of a petroleum resin prepared by copolymerization between A1: =30wt% of cyclopentadiene and/or dicyclopentadiene and A2: =70wt% of C5- and/or C9- fraction, by-product(s) from naphtha cracking other than the component A1 with a ratio of the double bond in the norbornene ring (ND) to that in the cyclopentene ring (CD):ND/CD falling between 0.2 and 0.9 (pref. between 0.3 and 0.7).