Functionalized Thermoplastic Polymer Rubber Composition for Tire Tread Stiffness Gradient
Solution Overview
Problem
Tire treads face a challenge in balancing high wear resistance, low rolling resistance, and excellent grip on various surfaces while maintaining good handling, as increased stiffness for better handling often compromises grip properties.
Innovation Solution
Incorporating functionalized thermoplastic polymers with specific functional groups into rubber compositions reinforced with inorganic fillers creates a stiffness gradient, improving the compromise between handling and grip by adjusting modulus at low strain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the amount of reinforcing filler is increased to improve handling stiffness, then the stiffness of the tread is improved, but the grip properties are adversely affected
Solution Approach 1:
The patent applies local quality by creating a stiffness gradient within the tread structure, where the surface portion has lower stiffness to maintain grip properties while the inner portion maintains higher stiffness for handling. This is achieved by using a multi-layer construction where at least one layer contains a specific amount of reinforcing filler (20-80 phr) and another layer contains a different amount (5-50 phr), allowing different regions of the tread to have optimized properties for their specific functions.
2Ease of operation
If the stiffness of the tread surface is increased to improve handling, then the handling performance is improved, but the grip on wet ground is prohibitively affected
Solution Approach 1:
The patent implements local quality by differentiating the stiffness characteristics between the tread surface layer and the inner tread layers. The surface layer is designed with optimized filler content to provide adequate grip on wet ground, while inner layers provide the necessary stiffness for handling. This layered approach allows the tread to exhibit context-dependent mechanical properties.
Solution Approach 2:
The patent uses composite materials by combining rubber compounds with different reinforcing filler contents in a multi-layer structure. Each layer acts as a composite material with tailored properties, where the overall tread performance emerges from the combination of layers with different stiffness characteristics, achieving both grip and handling requirements.
Data Source
AI summary
The present invention relates to a diene rubber composition reinforced with an inorganic filler comprising a thermoplastic polymer bearing, at at least one end, a silanol or silyl ether functional group. The presence of the functional thermoplastic polymer makes it possible to improve the compromise of performances, which are the handling and the grip, of a tire having a tread that is based on such a composition.