Tire Rubber Composition Using Cyclic Resin for Low-Tg Compatibility
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Solution Overview
Problem
Current tire compositions face challenges in achieving a balance between wear resistance, grip, and low rolling resistance due to poor compatibility between low glass transition temperature elastomers and hydrocarbon-based plasticizing resins, which affects their performance across various temperature conditions.
Innovation Solution
A rubber composition is developed using a specific hydrocarbon resin based on cyclic monomers from petroleum refinery streams or C4, C5, or C6 cyclic olefins, with specific aromatic proton content, glass transition temperature, and molecular weight, which improves compatibility and performance by enhancing the balance between wear resistance, grip, and rolling resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If low Tg elastomers are used to improve abrasion performance, then wear resistance is improved, but compatibility with hydrocarbon-based plasticizing resins deteriorates
Solution Approach 1:
The patent applies parameter changes by carefully selecting and controlling the glass transition temperature (Tg) of the elastomer within a specific range of -100°C to -50°C, and by selecting hydrocarbon resins with specific properties (aromatic content 20-40%, Tg of 0-100°C). This parameter optimization resolves the contradiction by finding the optimal balance point where the elastomer maintains low enough Tg for wear resistance while being compatible with hydrocarbon resins for proper plasticizing effect.
2Ease of manufacture
If hydrocarbon-based plasticizing resins are added to improve processability, then ease of manufacture is improved, but compatibility with low Tg elastomers deteriorates
Solution Approach 1:
The patent resolves this contradiction by changing the parameters of the hydrocarbon resin: selecting resins with aromatic content between 20-40% and glass transition temperature between 0-100°C. These specific parameter ranges ensure compatibility with low Tg elastomers while maintaining good processability and plasticizing effects during tire manufacturing.
3Strength
If tire composition is optimized for high grip, then grip performance is improved, but rolling resistance increases
Solution Approach 1:
The patent applies parameter changes by optimizing the elastomer's Tg within -100°C to -50°C range and the hydrocarbon resin's Tg within 0-100°C range, along with controlling aromatic content. This creates a balanced composition that provides adequate grip through proper polymer flexibility while minimizing energy loss through optimized material compatibility and reduced hysteresis.
Data Source
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AI summary
Described herein are tires comprising a rubber composition based on at least an elastomer matrix comprising from 50 to 100 phr of one or more copolymers of butadiene and of vinylaromatic monomer, having a content of vinylaromatic units of between 0 and 5% by weight and a Tg within a range extending from -110°C to -70°C; and a hydrocarbon resin, wherein said hydrocarbon resin is based on a cyclic monomer selected from the group consisting of a distillation cut from a petroleum refinery stream, and/or C4, C5 or C6 cyclic olefins and mixtures thereof, and wherein the hydrocarbon resin has a content of aromatic protons (H Ar, expressed in mol%), a glass transition temperature (Tg, is expressed in °C), and a number average molecular weight (Mn, expressed in g/mol that are represented by (1) H Ar > 6 mol%, (2) Tg ≥ 95 - 2.2 * (H Ar), and (3) Tg ≥ -53 + (0.265 * Mn).