Activated Micronized Rubber Compound for Tyre Reuse

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Solution Overview

Problem

There is a pressing global issue of managing end-of-life tyres in an environmentally friendly manner and maximizing their reuse, as current technologies lack effective methods to reintroduce micronized rubber powders into new tyres, thereby underutilizing their potential for CO2 reduction and circular economy principles.

Innovation Solution

A method involving the chemical activation of micronized rubber powders (MRP) using a combination of silica, silane, and functionalization components like diphenyl guanidine to enhance their performance and compatibility within rubber compounds, allowing high concentrations of activated/functionalized micronized rubber powder (FMRP) to be incorporated into natural rubber, and converting them into solid strips or slabs for efficient use in tyres.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a polybutadiene rubber compound is used to provide high rolling fatigue resistance, then rolling fatigue resistance is improved, but the compound becomes unsuitable for bias-ply tyre applications requiring specific flexibility and tear resistance

Engineering Contradiction:
Improverolling fatigue resistanceVSAvoidsuitability for bias-ply tyre applications
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates a composite rubber compound by blending polybutadiene rubber (providing rolling fatigue resistance) with at least one other elastomer such as natural rubber, SBR, or butyl rubber (providing flexibility and tear resistance). This composite approach allows the final compound to exhibit both high rolling fatigue resistance and the flexibility required for bias-ply tyre applications, resolving the contradiction between these two properties.

Inventive Principle:
Principle #40Composite materials

2Ease of manufacture

If conventional rubber compounds are used, then manufacturing is simple, but consistent quality control and precise property adjustment are difficult

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidquality control precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent establishes specific parameter ranges for the rubber compound composition (e.g., polybutadiene rubber content at 20-80 parts by weight per 100 parts of total rubber, specific silica content ranges, carbon black proportions) to achieve desired properties. By controlling these compositional parameters within defined ranges, the patent enables precise adjustment of compound properties such as rolling fatigue resistance, flexibility, and tear resistance, thereby improving manufacturing precision while maintaining relative simplicity in the manufacturing process.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If polybutadiene rubber content is increased to improve rolling fatigue resistance, then rolling fatigue resistance improves, but the compound becomes too hard and loses the flexibility needed for modern tyre designs

Engineering Contradiction:
Improverolling fatigue resistanceVSAvoidflexibility
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by using different elastomers with complementary properties in specific proportions within the compound. Polybutadiene rubber (50-90 Shore A hardness) is combined with softer elastomers like natural rubber (40-60 Shore A) or SBR to create regions of varying local flexibility. This allows the compound to maintain high rolling fatigue resistance from the polybutadiene while incorporating sufficient flexibility from the other elastomers, resolving the contradiction between hardness and flexibility.

Inventive Principle:
Principle #3Local quality

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 method significantly improves mechanical and dynamic performance of rubber compounds, enabling large-scale reuse of FMRP in tyres, enhancing properties such as tensile strength and tear resistance, and facilitating efficient transportation and reducing material costs.

Implementation Method 1

it has gradually come to light by experimentation that high silica contents in compounds based on polybutadiene rubber can improve the rolling fatigue resistance of tyres

Methodology Applied
Scientific EffectSilane-silica bonding: Chemical Bonding

Implementation Method 2

compounds based on polybutadiene rubber are intrinsically vulnerable to oxidation and ozone attack

Methodology Applied
Scientific EffectOxidation resistance: Oxidation

Implementation Method 3

compounds based on polybutadiene rubber are intrinsically vulnerable to oxidation and ozone attack

Methodology Applied
Scientific EffectOzone resistance: Oxidation

Data Source

PatentEP4558558B1A rubber compound mixture
Publication Date: 2026.05.13 KARGRO RECYCLING BV

AI summary

The present invention relates to a rubber compound mixture comprising a matrix of a non-vulcanized rubber including micronized rubber powders and one or more auxiliaries. The present invention also relates a method for preparing such a rubber compound mixture, as well as to a rubber article. An object of the present invention is to develop a method for chemically activating/functionalizing micronized rubber powders.