Rubber Composition Silica Distribution Wet Traction
Solution Overview
Problem
Existing tire technologies face a challenge in simultaneously achieving excellent wet performance and low rolling resistance, as these characteristics are conflicting and difficult to achieve simultaneously due to the miscibility issues and filler distribution in rubber compositions.
Innovation Solution
A rubber composition comprising modified styrene-butadiene rubber with a functional group interacting with silica, combined with hydrogenated non-modified nitrile rubber, which allows for preferential distribution of silica within the diene rubber component, enhancing both wet and rolling resistance performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If NBR is added to improve abrasion resistance, then abrasion resistance is improved, but silica is incorporated into NBR phase causing deterioration of rolling resistance performance
Solution Approach 1:
The patent divides the rubber composition into distinct phases: modified SBR forms the continuous phase that interacts with silica, while hydrogenated NBR forms discrete dispersed phases. This segmentation prevents silica from being incorporated into the NBR phase, as silica preferentially interacts with the modified SBR continuous phase. The dispersed hydrogenated NBR domains provide abrasion resistance without compromising rolling resistance performance.
Solution Approach 2:
The modified styrene-butadiene rubber acts as an intermediary between silica and hydrogenated NBR. The functional groups on modified SBR mediate the interaction with silica, creating a separate silica-modified SBR complex that prevents direct silica-NBR interaction. This intermediary role of modified SBR ensures silica distribution is controlled and prevents silica incorporation into hydrogenated NBR phase.
2Reliability
If modified SBR with functional groups is used to improve wet performance, then wet performance is improved, but the complexity of rubber composition increases
Solution Approach 1:
The patent merges multiple functions into the modified SBR component: it serves as the continuous matrix phase, provides the functional groups for silica interaction, and enables preferential silica distribution. By combining these roles in a single modified SBR material, the patent avoids the need for separate additives or complex multi-component systems, thereby improving wet performance without proportionally increasing composition complexity.
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 effectively balances wet performance and rolling resistance by suppressing silica incorporation into the hydrogenated nitrile rubber phase, thereby improving traction on wet surfaces while maintaining low rolling resistance and abrasion resistance.
Implementation Method 1
modified styrene-butadiene rubber modified with a functional group having an interaction with a silanol group on a surface of silica
Implementation Method 2
suppressing silica incorporation into the hydrogenated nitrile rubber phase
Data Source
AI summary
A rubber composition comprises 100 parts by mass of a diene rubber component comprising at least one selected from the group consisting of styrene-butadiene rubber, polybutadiene rubber, natural rubber and polyisoprene rubber, the diene rubber component containing modified styrene-butadiene rubber modified with a functional group having an interaction with a silanol group on a surface of silica, from 20 to 120 parts by mass of silica, and from 3 to 30 parts by mass of hydrogenated non-modified nitrile rubber. A pneumatic tire has a rubber part comprising the rubber composition.