Phenol-Modified Rubber Composition for Run Flat Tire Sidewalls
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Solution Overview
Problem
Current tire technologies face challenges in achieving improved run flat durability, side cut resistance, and steering stability while maintaining ride comfort and normal running performance.
Innovation Solution
A rubber composition is developed by mixing specific amounts of filler, phenol resin, methylene donor, thiuram-based vulcanization accelerating agent, and sulfenamide-based vulcanization accelerating agent with a modified conjugated diene-based polymer, combined with a carcass ply reinforcing cord having an intermediate elongation of 4.2% or less and toughness of 45 cN·%/dtex or more.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a side reinforcing layer using a rubber composition containing high carbon black content (55 parts by mass or more based on 100 parts by mass of rubber component) is used to enhance run flat durability, then run flat durability is improved, but rolling resistance increases and ride comfort deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the rubber compound by introducing a specific phenolic resin system (0.5-2.0 parts by mass based on 100 parts by mass of rubber component) that reacts with amino groups on the rubber polymer chains. This chemical modification alters the crosslinking structure and reduces hysteresis loss, thereby decreasing rolling resistance while preserving the reinforcing effect of carbon black for run flat durability.
Solution Approach 2:
The patent creates a composite rubber material system combining rubber component, carbon black, and phenolic resin with amino groups. The phenolic resin acts as a coupling agent that forms a composite network structure between rubber chains and carbon black particles, optimizing the balance between reinforcement (for run flat durability) and energy dissipation (affecting rolling resistance).
2Strength
If the side wall rigidity is increased to improve side cut resistance and steering stability, then side cut resistance and steering stability are improved, but ride comfort deteriorates
Solution Approach 1:
The patent modifies the rubber compound's viscoelastic parameters through phenolic resin addition, which changes the loss tangent (tan δ) characteristics. This allows the side wall to maintain higher rigidity at high frequencies (improving side cut resistance) while preserving flexibility at low frequencies (maintaining ride comfort).
Solution Approach 2:
The phenolic resin-modified rubber composition exhibits dynamic mechanical properties that adapt to different loading conditions. The material shows frequency-dependent stiffness, providing rigidity when needed for structural support but flexibility for comfort, effectively making the side wall properties dynamic rather than static.
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 enhances run flat durability, side cut resistance, and steering stability while maintaining ride comfort and reducing heat generation, thereby improving the overall performance of tires.
Implementation Method 1
a phenol resin (C), 0.07 to 0.2 parts by mass of a methylene donor (D)... 0.9 to 2.4 parts by mass of a phenol resin (C), 0.07 to 0.2 parts by mass of a methylene donor (D)
Implementation Method 2
a phenol resin (C), 0.07 to 0.2 parts by mass of a methylene donor (D)... allowing the intermediate elongation and the toughness of a reinforcing cord of a carcass ply to satisfy a specific relation
Implementation Method 3
1.5 to 2.1 parts by mass of a thiuram based vulcanization accelerating agent (E), and 3.2 to 4.5 parts by mass of a sulfenamide based vulcanization accelerating agent (F)
Implementation Method 4
a thiuram based vulcanization accelerating agent (E), and 3.2 to 4.5 parts by mass of a sulfenamide based vulcanization accelerating agent (F)
Implementation Method 5
60 to 100 parts by mass of a filler (B)... mixing specific amounts of a filler (B), a phenol resin (C)
Implementation Method 6
a rubber component comprising 20 to 80% by mass of a modified conjugated diene based polymer (A)
Data Source
AI summary
The present invention provides: a rubber composition prepared by mixing 60 to 100 parts by mass of a filler (B), 0.9 to 2.4 parts by mass of a phenol resin (C), 0.07 to 0.2 parts by mass of a methylene donor (D), 1.5 to 2.1 parts by mass of a thiuram based vulcanization accelerating agent (E), and 3.2 to 4.5 parts by mass of a sulfenamide based vulcanization accelerating agent (F), based on 100 parts by mass of the rubber component comprising 20 to 80% by mass of a modified conjugated diene based polymer (A), allowing the ride comfort in normal running to be satisfied in parallel with improvement in the run flat durability (durability in run flat running); and a tire comprising at least one member selected from the group consisting of a side reinforcing rubber layer and a bead filler using the rubber composition.