Rubber Composition Modulus Ratio for Low Loss and Crack Resistance

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Solution Overview

Problem

Current rubber compositions struggle to achieve a balance between low rolling resistance and high crack growth resistance, as reducing carbon black content to improve low loss property tends to deteriorate crack resistance.

Innovation Solution

A rubber composition with a specific ratio of 200% modulus to 50% modulus value (≤5.0) is achieved by incorporating carbon black with a DBP absorption of 50-100 cm^3/100g, phenol resin, and a methylene donor, along with silica, to enhance both low loss property and crack growth resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the amount of carbon black blended with the belt coating rubber is reduced to improve low loss property, then rolling resistance is reduced, but crack growth resistance is deteriorated

Engineering Contradiction:
Improvelow loss propertyVSAvoidcrack growth resistance
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the DBP absorption value of carbon black to 50-100 cm³/100g and the ratio of 200% modulus to 50% modulus to 5.0 or less. This optimization allows the rubber composition to achieve both low loss property and high crack growth resistance by adjusting the physical parameters of the carbon black and the overall composition rather than simply increasing or decreasing carbon black content

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses composite materials by combining carbon black with specific properties (DBP absorption 50-100 cm³/100g) with phenol resin and methylene donor in a rubber composition. This composite approach creates a synergistic effect where the combination of materials achieves both low rolling resistance and high crack growth resistance, overcoming the limitations of using carbon black alone

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP3640293B1Rubber composition, belt-coating rubber, and tire
Publication Date: 2022.03.30 BRIDGESTONE CORP

AI summary

An object of the present disclosure is to provide a rubber composition which can attain both low loss property and crack growth resistance on a high level. In order to achieve the object, the rubber composition of the present disclosure contains: a rubber component; carbon black having a DBP absorption of 50 to 100 cm3/100 g; a phenol resin; and a methylene donor, wherein a ratio of a 200% modulus value (M200) to a 50% modulus value (M50) is 5.0 or less (M200/M50 ≤ 5.0).