Self-Adherent Composite Reinforcement for Tyre Cover

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Solution Overview

Problem

Existing adhesive systems for metal reinforcements in pneumatic tires, such as RFL adhesives, contain formaldehyde, which is undesirable due to regulatory concerns, and require metal salts that increase costs and sensitivity to oxidation and aging, necessitating the development of alternative adhesive systems or reinforcements.

Innovation Solution

A composite reinforcement featuring a thermoplastic polymer layer with a positive glass transition temperature and an unsaturated thermoplastic styrenic elastomer with a negative glass transition temperature, allowing for direct adhesion to diene rubber matrices without the need for additional adhesives or metal salts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If RFL adhesives are used to bond metal reinforcements to rubber, then adhesion is achieved, but formaldehyde content increases and metal salts are required which increase cost and oxidation sensitivity

Engineering Contradiction:

ImproveadhesionVSAvoidformaldehyde content

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and eliminates formaldehyde and metal salts from the adhesive system by using a thermoplastic polymer coating on the reinforcement that provides adhesion through physical bonding and chemical groups inherent in the polymer structure, rather than through formaldehyde-based RFL adhesives

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention changes the chemical composition parameters of the adhesive system by replacing formaldehyde and metal salt-based adhesives with a thermoplastic polymer coating containing specific functional groups (carboxyl, hydroxyl, amino) that provide adhesion without harmful substances

Inventive Principle:

Principle #35Parameter changes

2Reliability

If RFL adhesives with metal salts are used, then adhesion is maintained, but cost and sensitivity to oxidation and aging increase

Engineering Contradiction:

ImproveadhesionVSAvoidcost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The invention extracts metal salts from the adhesive system and replaces them with a thermoplastic polymer coating that provides adhesion through its own chemical groups, eliminating the need for costly metal salt additives

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention uses a thermoplastic polymer coating that is inherently part of the reinforcement structure, eliminating the need for separate expensive adhesive applications with metal salts, thereby reducing overall manufacturing cost

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If thermoplastic polymer coating is applied to reinforcement, then direct adhesion to rubber is enabled, but the polymer must withstand processing temperatures and provide sufficient bond strength

Engineering Contradiction:

ImproveadhesionVSAvoidglass transition temperature

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The invention selects thermoplastic polymers with specific glass transition temperatures above ambient operating conditions but below tire curing temperatures, allowing the coating to remain rigid during use but become sufficiently soft during processing to bond with rubber

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention uses composite thermoplastic polymer coatings that combine multiple polymer components or addtives to achieve the desired balance between thermal stability for processing and adhesion performance at operating temperatures

Inventive Principle:

Principle #40Composite materials

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

This solution enables efficient, RFL-free adhesion of the composite reinforcement to diene rubber matrices, eliminating the need for metal salts and formaldehyde, thereby reducing costs and improving durability while meeting regulatory requirements.

Implementation Method 1

an unsaturated thermoplastic styrenic elastomer whose temperature of glass transition of the elastomeric block is negative... efficient adhesion of the composite reinforcement to a matrix or composition of diene elastomer

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2618976B1Tyre cover comprising a self-adherent composite reinforcement

Publication Date: 2014.05.14 MICHELIN & CO (CIE GEN DES ESTAB MICHELIN)

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AI summary

The invention relates to a tyre cover comprising a self-adherent composite reinforcement (R-2) which adheres to a diene rubber matrix by curing, comprising: one or more reinforcing filaments (20), for example a carbon steel cord; covering said filament, each filament individually or several filaments collectively, a layer of a thermoplastic polymer composition comprising, on the one hand, a thermoplastic polymer having a positive glass transition temperature and, on the other hand, an unsaturated styrene thermoplastic elastomer having a negative glass transition temperature.