Tire Composition Balancing Raw Stickiness and Rolling Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Recent developments in low rolling resistance tires have led to a reduction in raw stickiness, making it difficult to achieve a balance between stickiness, rolling resistance, adhesion, and wear, as tackifying resins increase hysteresis and brightening solvents release volatile organic compounds.
Innovation Solution
A tire composition comprising a specific blend of polyisoprene, polybutadiene, styrene butadiene copolymer, inorganic reinforcing filler, carbon black, plasticizing oil, and hydrocarbon resin, with a filler-to-plasticizer ratio between 0.8 and 2.2, which maintains excellent raw stickiness and rolling resistance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tackifying resins are used to increase raw tackiness, then raw stickiness is improved, but hysteresis increases leading to higher rolling resistance
Solution Approach 1:
The invention changes the chemical composition parameters of the rubber compound by incorporating a specific ratio of liquid polymer (5-20 phr) with high unsaturation and low glass transition temperature, combined with controlled amounts of sulfur (0.5-2.0 phr) and zinc oxide (1-5 phr). This parameter optimization achieves adequate raw stickiness without the excessive hysteresis caused by traditional tackifying resins
Solution Approach 2:
The invention creates a composite rubber composition integrating multiple components: diene polymer (70-85 phr), liquid polymer (5-20 phr), sulfur (0.5-2.0 phr), zinc oxide (1-5 phr), and optional extenders. This composite formulation synergistically balances raw stickiness and hysteresis properties that cannot be achieved with single-component tackifiers
2Reliability
If brightening solvents are used to increase raw tackiness, then raw stickiness is improved, but volatile organic compounds are released
Solution Approach 1:
The invention extracts and eliminates brightening solvents from the rubber compound formulation. Instead, it uses liquid polymers with inherently high tackiness properties (such as liquid polyisoprene or liquid polybutadiene) that provide raw stickiness without releasing volatile organic compounds during processing or service
Solution Approach 2:
The invention replaces persistent organic solvents with liquid polymers that serve their tackifying function and then become part of the cured rubber matrix, eliminating the need for volatile carriers that would evaporate and create environmental pollution
3Loss of energy
If rolling resistance is reduced through composition modification, then energy efficiency is improved, but raw stickiness decreases making tire manufacturing difficult
Solution Approach 1:
The invention optimizes the glass transition temperature parameter of the rubber compound by selecting liquid polymers with Tg below -50°C and controlling the ratio of liquid polymer to diene polymer between 5:95 and 20:80. This parameter adjustment maintains low rolling resistance while preserving adequate raw stickiness for manufacturing
Solution Approach 2:
The invention applies different functional properties to different aspects of the rubber compound: the liquid polymer component provides local high tackiness for manufacturing, while the overall composition maintains low hysteresis for low rolling resistance during tire operation
Data Source
AI summary
The invention relates to a tire comprising a rubber composition based on at least: 10 to 25 phr of polyisoprene; 30 to 40 phr of polybutadiene; 45 to 60 phr of butadiene styrene copolymer, the styrene content of which is less than 40 percent by weight; 90 to 150 phr of inorganic reinforcing filler; 1 to 10 phr of carbon black; 50 to 100 phr of a plasticizer system comprising 25 to 50 phr of plasticizing oil and 25 to 50 phr of hydrocarbonated resin; in said composition, the amounts of filler and plasticizer are selected such that the ratio of the amount of filler in phr to the amount of plasticizer in phr ranges from 0.8 to 2.2.