Elastomer Laminate Adhesion via Ethylene-Diene Copolymer

The patent introduces an intermediate layer with a specific copolymer composition (ethylene and 1,3-diene in ratios of 70:30 to 90:10) that acts as a mediator between the tread layer and sidewall layer. This intermediate composition provides chemical compatibility with both adjacent layers, enabling effective adhesion while maintaining the distinct functional properties of each layer. The intermediate layer serves as a bridge that reconciles the compositional differences between tread and sidewall materials.

The patent modifies the compositional parameters of the intermediate layer by controlling the ethylene-to-1,3-diene ratio and the molecular weight of the copolymer. By adjusting these parameters, the intermediate layer achieves optimal adhesion properties while maintaining compatibility with both the tread and sidewall layers. The specific parameter range (70:30 to 90:10 ethylene-to-1,3-diene ratio) is critical for achieving the desired balance between adhesion and functional performance.

The patent optimizes the ethylene content parameter within a specific range (70:30 to 90:10 ethylene-to-1,3-diene ratio) rather than using maximum ethylene content. This controlled parameter change ensures sufficient adhesion while maintaining the flexibility and elongation properties necessary for tire performance. The 1,3-diene component provides the required elasticity and flexibility that would be lost with higher ethylene content.

The intermediate layer uses a composite copolymer structure combining ethylene and 1,3-diene units. This composite material approach allows the layer to exhibit both adhesive properties (from the ethylene component) and flexibility (from the 1,3-diene component). The synergistic combination of the two monomers in specific ratios creates a material that balances adhesion and flexibility requirements.