Ultra-Efficient Sulfur Curing System for Tire Tread
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Tire designers face a compromise between tire wear and wet braking performance, as improving one characteristic often results in a decline in the other, particularly due to the trade-off between polybutadiene content in the tread's rubber composition.
Innovation Solution
A tire tread composition featuring a cross-linkable elastomer with high unsaturated diene elastomer and inorganic reinforcing filler, combined with a plasticizing system and an ultra-efficient sulfur curing system, which maintains good material cohesion and improves traction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If polybutadiene content in the tread's rubber composition is increased to improve tire wear, then tire wear is improved, but wet braking performance deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the sulfur to accelerator weight ratio to between 0.02 and 0.2, which is a significant deviation from conventional ratios. This parameter adjustment enables the rubber composition to achieve both improved wear resistance and maintained wet braking performance by controlling the cross-linking density and network structure of the vulcanized rubber
Solution Approach 2:
The patent uses composite materials by combining highly unsaturated diene elastomer with specific inorganic reinforcing fillers (such as silica or carbon black) in optimized proportions. This composite approach allows the tread to simultaneously achieve enhanced wear resistance through filler reinforcement and good wet braking performance through the elastomer's inherent properties
2Reliability
If polybutadiene content is decreased to improve wet braking performance, then wet braking performance is improved, but tire wear deteriorates
Solution Approach 1:
The patent changes the sulfur to accelerator ratio parameter to a low range (0.02-0.2) and adjusts the inorganic filler content to between 95-160 phr, creating a vulcanization system that achieves optimal balance between wet braking performance and wear resistance without relying on high polybutadiene content
Solution Approach 2:
The patent employs composite materials consisting of diene elastomer blended with inorganic reinforcing fillers in specific proportions, where the filler provides wear resistance while the elastomer matrix maintains wet braking performance, eliminating the need to sacrifice one property for the other
3Force
If inorganic reinforcing filler content is increased to improve traction, then traction is improved, but material cohesion deteriorates
Solution Approach 1:
The patent applies parameter changes by optimizing the sulfur to accelerator ratio to between 0.02 and 0.2, which controls the cross-linking density and ensures that even with high inorganic filler content (95-160 phr), the rubber matrix maintains sufficient material cohesion and prevents chunking
Solution Approach 2:
The patent uses an intermediary ultra-efficient vulcanization system that acts as a mediator between the inorganic reinforcing fillers and the rubber matrix. This vulcanization system, with its optimized sulfur to accelerator ratio, creates effective bonding between filler particles and rubber, ensuring both high traction from filler reinforcement and good material cohesion from proper cross-linking
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 solution provides improved traction while maintaining material cohesion, reducing chunking and extending the tire's operational life, making it suitable for all-weather and summer tires.
Implementation Method 1
The rubber composition is cured with an ultra-efficient sulfur curing system having a sulfur to accelerator weight ratio adjusted between 0.02 and 0.2 to provide the rubber composition with an MA300/G* ratio of greater than 1.7
Implementation Method 2
The composition may further include between 60 phr and 130 phr of a plasticizing system comprising a plasticizing resin having a Tg of at least 25 °C and a plasticizing liquid. The rubber composition has a glass transition temperature of between -35 °C and 0 °C
Data Source
AI summary
Tire treads having improved traction properties while surprisingly still maintaining good material cohesion properties, the tire treads comprising a rubber composition based upon a highly unsaturated diene elastomer and between 95 phr and 160 phr of an inorganic reinforcing filler. The composition may further include between 60 phr and 130 phr of a plasticizing system made up of a plasticizing resin having a Tg of at least 25 °C and a plasticizing liquid. The rubber composition is cured with an ultra-efficient sulfur curing system having a sulfur to accelerator weight ratio adjusted between 0.02 and 0.2 to provide the rubber composition with an MA300/G* ratio of greater than 1.7, wherein the elongation modulus MA300 at 300 % is measured at 23 °C and the shear modulus G* is measured at 60 °C.