Abstract: A tire sidewall rubber member according to an embodiment is made of a rubber composition containing: a diene rubber; a reinforcing filler containing 75 mass % or more of carbon black; a processing aid; a compound represented by formula (I) (wherein R1 and R2 represent a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, and M+ is Na+, K+ or Li+). The processing aid to be used is at least one selected from the group consisting of a fatty acid metal salt, a fatty acid amide and a fatty acid ester, and having a difference (Tm3?Tm1) between a start point (Tm1) and an end point (Tm3) of an endothermic peak measured by a differential scanning calorimeter of 50° C. or more. Thus, tear resistance is improved while maintaining low heat generation properties and hardness.

Abstract: A method for producing a tire sidewall rubber member according to an embodiment comprises: a first kneading step of preparing a first kneaded product by kneading a diene rubber, carbon black, a compound represented by formula (I) (wherein R1 and R2 represent a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, and M+ is Na+, K+ or Li+), and zinc oxide; and a second kneading step of adding wax and/or stearic acid to the first kneaded product, followed by kneading. Thus, low heat generation properties are improved while suppressing the deterioration of tear resistance.

Abstract: A method for producing a tire sidewall rubber member according to an embodiment comprises: a first kneading step of preparing a first kneaded product by kneading a diene rubber, carbon black, a compound represented by formula (I) (wherein R1 and R2 represent a hydrogen atom, an alkyl group, an alkenyl group or an alkynyl group, and M+ is Na+, K+ or Li+), and zinc oxide; and a second kneading step of adding wax and/or stearic acid to the first kneaded product, followed by kneading. Thus, low heat generation properties are improved while suppressing the deterioration of tear resistance.