Rubber Composition with Controlled Crumb Extracts for Tire Tread

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Solution Overview

Problem

Tire manufacturers face challenges in reducing the cost of rubber compositions without compromising the performance of tires, particularly in achieving excellent fluidity and tear resistance properties.

Innovation Solution

A rubber composition based on an elastomer, reinforcing filler, and crosslinking system, incorporating rubber crumbs with specific characteristics such as an acetone extract of 8-50% by weight, a chloroform extract ratio less than 1.5, mass average molecular mass less than 10,000 g/mol, and a plasticizer level greater than 8% by mass, which are used in the tire's tread.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If rubber powder is used in tire compounds to reduce costs, then manufacturing cost decreases, but fluidity and tear resistance properties deteriorate

Engineering Contradiction:
Improvemanufacturing costVSAvoidtear resistance
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies parameter changes by precisely controlling the plasticizer content (8-50% by mass) and molecular weight (Mw < 10,000 g/mol) of the rubber powder components. This optimization of material parameters enables the use of rubber powder while maintaining or improving fluidity and tear resistance, thus resolving the contradiction between cost reduction and performance maintenance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite rubber composition by combining rubber powder with specific plasticizers and other compounding ingredients. This composite approach allows the synergistic interaction between components to overcome the inherent deficiencies of rubber powder alone, achieving both cost effectiveness and superior mechanical properties

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If rubber powder with high plasticizer content is used to improve fluidity, then processing becomes easier, but material cost increases

Engineering Contradiction:
ImprovefluidityVSAvoidmaterial cost
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The patent optimizes the plasticizer content within a specific range (8-50% by mass) and controls the molecular weight (Mw < 10,000 g/mol) to achieve the desired fluidity. This parameter optimization ensures adequate processing ease while avoiding excessive plasticizer addition that would increase material costs

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies local quality by using different plasticizer types (oil-based vs. resin-based) with distinct properties for different performance requirements. Oil-based plasticizers contribute to fluidity while resin-based plasticizers enhance structural integrity, allowing cost-effective formulation with targeted functionality

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3558710B1Rubber composition comprising a specific crumb rubber
Publication Date: 2023.03.29 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

AI summary

The invention relates to a rubber composition comprising at least one elastomer, a reinforcing filler, and a crosslinking system and a crumb rubber, said crumb rubber containing: an acetone extract of between 8 and 50 wt.-%; a chloroform extract such that the ratio of chloroform extract to acetone extract, expressed by weight percent, is less than 1.5, the chloroform extract having a weight-average molecular weight (Mw) of less than 10000 g/mol; and a plasticiser content of greater than 8 wt.-% in the composition of the crumb.