Three-Elastomer Tire Tread Composition for Rolling Resistance and Wet Grip
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tire technologies face challenges in balancing good rolling resistance and wet traction while maintaining acceptable wear characteristics, as improvements in one property often come at the expense of another.
Innovation Solution
A pneumatic tire using a vulcanizable rubber composition comprising a blend of styrene-butadiene rubber, polybutadiene, and natural or synthetic polyisoprene, along with silica, carbon black, rubber processing oil, and hydrocarbon resin, which are carefully formulated to achieve optimal viscoelastic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If rubbers with low hysteresis are used to reduce rolling resistance, then rolling resistance is improved, but wet skid resistance deteriorates
Solution Approach 1:
The tread rubber is divided into three distinct elastomer components (styrene-butadiene rubber, polybutadiene, and natural rubber or synthetic polyisoprene), each contributing different viscoelastic properties. This segmentation allows the composition to achieve both low rolling resistance and high wet skid resistance by combining materials with complementary characteristics rather than relying on a single rubber type.
Solution Approach 2:
The invention uses a composite rubber composition combining three different elastomers with specific glass transition temperature ranges. This composite approach creates a material that exhibits both low hysteresis (for reduced rolling resistance) and appropriate adhesion characteristics (for wet skid resistance), resolving the contradiction between these two opposing requirements.
2Loss of energy
If mixtures of synthetic and natural rubber are used to balance viscoelastic properties, then rolling resistance is improved, but wet traction deteriorates
Solution Approach 1:
The invention specifies precise glass transition temperature ranges for each elastomer component (Tg(A)−Tg(B)≥25° C. and Tg(B)−Tg(C)≥25° C.) to optimize the viscoelastic properties. By carefully controlling these thermal parameters and the proportions of each rubber type, the composition achieves both low rolling resistance and high wet traction, overcoming the trade-off present in conventional mixtures.
3Ease of manufacture
If conventional rubber compositions are used, then manufacturing is simple, but it is difficult to improve wear characteristics without sacrificing wet skid resistance and traction
Solution Approach 1:
The invention employs a three-elastomer composite composition that can be manufactured using conventional rubber processing techniques. The specific formulation (25-35 phr styrene-butadiene rubber, 45-75 phr polybutadiene, and 5-15 phr natural rubber or synthetic polyisoprene) provides improved wear characteristics while maintaining good wet skid resistance and traction, achieving performance improvements without requiring complex manufacturing changes.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The tire composition achieves improved wet and dry traction while maintaining equivalent wear performance compared to control tires, effectively balancing rolling resistance and traction.
Implementation Method 1
These properties depend, to a great extent, on the dynamic viscoelastic properties of the rubbers utilized in making the tire
Implementation Method 2
rubbers having a low hysteresis have traditionally been utilized in making tire tread rubber compounds
Implementation Method 3
the styrene-butadiene rubber is a functionalized solution polymerized styrene-butadiene elastomer having a glass transition temperature Tg(A) ranging from −30 to −10° C.
Data Source
AI summary
A pneumatic tire comprising a vulcanizable rubber composition which comprises: 1) 100 parts by weight of elastomer consisting of 25 to 35 phr of a styrene-butadiene rubber, 45 to 75 phr of a polybutadiene, and 5 to 15 phr of a natural rubber or synthetic polyisoprene, wherein the styrene-butadiene rubber is a functionalized and has a Tg(A) ranging from −30 to −10° C.; the natural rubber or synthetic polyisoprene has a Tg(B) ranging from −60 to −70° C.; and the polybutadiene is a cis 1,4 polybutadiene having a Tg(C) ranging from −110 to −90° C., wherein Tg(A)−Tg(B)≥25° C., and Tg(B)−Tg(C)≥25° C.; 2) 70 to 100 phr of silica; 3) 1 to 20 phr of carbon black; 4) 1 to 15 phr of rubber processing oil; and 5) 5 to 50 phr of at least one hydrocarbon resin having a Tg≥20° C. and a rosin derived resin.