Tread Rubber Composition for Wet Grip, Wear, and Bleed Resistance
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Solution Overview
Problem
Tires face challenges in achieving a well-balanced performance in terms of abrasion resistance, wet grip performance, and bleed resistance.
Innovation Solution
A tire with a tread containing a rubber composition that includes a rubber component and a branched conjugated diene polymer, where the polymer is a copolymer with structural units of branched conjugated diene, butadiene, and styrene, and the tire satisfies specific relationships regarding the weight average molecular weight of the polymer and the groove area ratio of the tread.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional rubber compositions are used, then manufacturing is simple, but abrasion resistance, wet grip performance, and bleed resistance cannot be improved in a well-balanced manner
Solution Approach 1:
The patent uses a composite rubber composition containing multiple specific components: branched conjugated diene polymer (with controlled molecular weight and composition), polybutadiene rubber, styrene-butadiene rubber, silica, and carbon black. This composite approach allows simultaneous improvement of abrasion resistance, wet grip performance, and bleed resistance by combining materials with complementary properties.
Solution Approach 2:
The patent specifies precise parameter ranges for the branched conjugated diene polymer including weight average molecular weight (10,000-100,000), composition ratios (branched conjugated diene units: 20-80 mass%, butadiene units: 10-60 mass%, styrene units: 5-30 mass%), and viscosity (10-100 mm²/s at 100°C). These controlled parameter changes enable optimized performance balance without excessive complexity.
Data Source
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AI summary
Provided is a tire with excellent overall performance in terms of abrasion resistance, wet grip performance, and bleed resistance. The present invention relates to a tire which includes a tread including a rubber composition that contains a rubber component and a branched conjugated diene polymer, wherein the branched conjugated diene polymer is a copolymer at least containing a branched conjugated diene, butadiene, and styrene as structural units, and the tire satisfies the following relationships (1) and (2): Relationship (1): 0.25 < A ≤ 1.50; and Relationship (2): A × S ≤ 27.0, wherein A is defined by A = 42.9/√α + 0.14 wherein α represents the weight average molecular weight of the branched conjugated diene polymer; and S represents the groove area ratio (%) of the ground contact surface of the tread.