Silica-Reinforced Tire Tread Rubber for Wet Grip and Cold Flexibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing tire tread rubber compositions struggle to balance good wet traction with low temperature performance, particularly in winter conditions, due to challenges in reducing cured stiffness and maintaining processing conditions.
Innovation Solution
A rubber composition combining high and low glass transition temperature styrene-butadiene elastomers with silica reinforcement, using vegetable triglyceride oil extension and reduced silica coupling agent levels, along with optimized silanization times and temperatures, to enhance cold weather performance and processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high molecular weight diene-based elastomers with high glass transition temperatures are used to improve wet traction, then wet traction performance is improved, but cold weather performance deteriorates due to increased cured stiffness
Solution Approach 1:
The patent changes the glass transition temperature parameter of the elastomer by using a combination of high Tg S-SBR and low Tg E-SBR in specific ratios, allowing optimization of both wet traction and cold weather performance through parameter adjustment rather than material substitution
Solution Approach 2:
The patent creates a composite elastomer system by combining solution polymerized styrene-butadiene rubber (S-SBR) and emulsion polymerized styrene-butadiene rubber (E-SBR) in specific weight ratios, where each component contributes different properties that together resolve the contradiction between wet traction and cold weather performance
2Ease of manufacture
If petroleum-based rubber processing oil is added to reduce uncured viscosity for better processing conditions, then processing ease is improved, but cured stiffness cannot be sufficiently reduced for low temperature performance
Solution Approach 1:
The patent changes the chemical composition parameter of the processing oil from petroleum-based to vegetable triglyceride-based, which fundamentally alters the interaction with the rubber matrix and enables simultaneous improvement of processing conditions and reduction of cured stiffness at low temperatures
Solution Approach 2:
The patent replaces expensive petroleum-based processing oils with more economical vegetable triglyceride oils, achieving better performance outcomes while reducing cost, though the vegetable oils require careful control of their transient effects during processing
3Temperature
If vegetable triglyceride oil is used to extend high Tg S-SBR to improve cold weather performance, then cold weather performance is improved, but wet traction may be compromised
Solution Approach 1:
The patent precisely controls the weight ratio parameter of S-SBR to E-SBR and the amount of vegetable triglyceride oil added, optimizing the balance between cold weather performance improvement and maintenance of wet traction capability
Solution Approach 2:
The patent applies vegetable triglyceride oil extension specifically to the high Tg S-SBR component rather than uniformly to the entire rubber composition, allowing localized modification of the elastomer properties to improve cold weather performance while preserving wet traction through the unextended low Tg E-SBR component
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 composition achieves improved hysteresis and Payne effect, resulting in enhanced wet traction and cold weather performance while maintaining processing efficiency.
Implementation Method 1
the relatively high Tg S-SBR is preferably extended with triglyceride based vegetable oil to promote cold weather (winter) tire performance
Implementation Method 2
optimized silanization times and temperatures
Implementation Method 3
curing the productive rubber composition comprising sulfur and accelerator
Data Source
AI summary
A rubber composition is disclosed comprising: (1) 10 phr to 70 phr of a solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) which is within the range of from -85°C to -20°C, and a bound styrene content which is within the range of from 10 to 40 percent; (2) 0 phr to 50 phr of emulsion polymerized styrene-butadiene rubber having a glass transition temperature (Tg) which is within the range of from -65°C to -45°C and having a bound styrene content which is within the range of 15 to 30 percent; (3) 20 phr to 60 phr of a 1,4-polybutadiene rubber having a cis 1,4-isometric content of at least 95 percent and having a glass transition temperature (Tg) which is within the range of from -90 °C to -110°C; (4) 50 phr to 250 phr of silica, preferably precipitated silica or amorphous synthetic precipitated silica; and (5) from 2 phr to 10 phr a carbon black. The silica is treated with 3 phf to 6 phf of a silica coupling agent. Also, a tire comprising such a rubber composition is disclosed and a method of manufacturing.