Hydrogenated Diene Rubber Composition for Balanced Tire Properties
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rubber compositions for pneumatic tires face challenges in achieving a balanced improvement in fuel economy, rubber tensile strength, abrasion resistance, tear properties, heat resistance, and ozone resistance, with hydrogenated diene polymers exhibiting slower cure rates and poor tear properties when used alone or in combination with general-purpose rubbers.
Innovation Solution
A rubber composition comprising a hydrogenated copolymer with a degree of hydrogenation of 75 mol% or more, combined with a second polymer having a specific double bond-containing diene content and weight average molecular weight, to form a phase structure that enhances tear properties while maintaining improved fuel economy, tensile strength, abrasion resistance, and heat resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If hydrogenated diene polymers are used to improve fuel economy, then fuel efficiency increases, but abrasion resistance and rubber tensile strength deteriorate
Solution Approach 1:
The invention uses a composite rubber composition combining hydrogenated diene polymer (70-95 parts) with conventional diene polymer (5-30 parts) and styrene-butadiene rubber (5-20 parts). This composite approach allows the hydrogenated polymer to provide fuel economy benefits while the conventional polymers maintain tensile strength and abrasion resistance, resolving the trade-off between fuel efficiency and mechanical properties.
2Reliability
If antioxidants and wax are increased to improve heat resistance and ozone resistance, then tire life increases, but tire appearance deteriorates due to surface migration
Solution Approach 1:
The invention extracts the primary protective function from antioxidants and wax by using hydrogenated diene polymer as the main protective agent. The hydrogenated polymer provides heat resistance and ozone resistance through its saturated chemical structure without the migration issue, allowing antioxidants and wax to be used in minimal amounts solely for maintaining appearance, thus resolving the contradiction between protection and appearance.
3Strength
If hydrogenated copolymers are combined with general-purpose rubbers to improve tear properties, then tear strength increases, but the hydrogenated copolymer's cure rate advantage is lost due to preferential curing of general-purpose rubbers
Solution Approach 1:
The invention changes the chemical composition parameters by using predominantly hydrogenated diene polymer (70-95 parts) with specific saturation levels, rather than small amounts of hydrogenated copolymer in conventional rubber. This parameter change ensures uniform cure rate across the composition while maintaining improved tear properties, as the hydrogenated polymer's saturation level controls curing behavior without the preferential curing issue.
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 proposed rubber composition achieves a balanced improvement in fuel economy, rubber tensile strength, abrasion resistance, tear properties, heat resistance, and ozone resistance, with the second polymer's similar cure rate preventing deterioration of the hydrogenated copolymer's effects, resulting in a more durable and efficient tire material.
Implementation Method 1
a first polymer which is a hydrogenated copolymer containing a structural unit derived from an aromatic vinyl compound and a structural unit derived from a conjugated diene compound and has a degree of hydrogenation of the conjugated diene portion of 75 mol% or more
Data Source
AI summary
Provided is a pneumatic tire that shows a balanced improvement in fuel economy, rubber tensile strength, abrasion resistance, tear properties, heat resistance, and ozone resistance. The present invention relates to a pneumatic tire formed from a rubber composition, the rubber composition containing a first polymer and a second polymer, the first polymer being a hydrogenated copolymer that contains a structural unit derived from an aromatic vinyl compound and a structural unit derived from a conjugated diene compound and has a degree of hydrogenation of the conjugated diene portion of 75 mol% or more, the second polymer having a double bond-containing diene content of 20% by mass or less and a weight average molecular weight of 200,000 to 2,000,000.