Metal-Resin Laminate with Rubber Interlayer for Thermal Stress Relief

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Solution Overview

Problem

Conventional laminated products with metal and resin bodies experience stress due to thermal shrinkage, limiting the joining strength and durability, particularly in applications like airless tires.

Innovation Solution

Incorporating a vulcanized rubber layer between the resin body and the adhesion layer to absorb thermal stress, enhancing the joining strength by using a halogenated rubber with a specific complex elastic modulus and thickness, and employing a chlorinated rubber-based adhesion layer for improved adhesiveness and heat resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a metal body and a resin body are joined together with an adhesion layer therebetween, then the laminated product can be formed for various applications including airless tires, but the joining strength is limited due to stress from thermal shrinkage differences

Engineering Contradiction:
Improvejoining strengthVSAvoiddurability
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

A rubber layer is introduced as an intermediary between the resin body and the adhesion layer. This rubber layer serves as a stress-absorbing buffer that accommodates the thermal expansion differences between the metal and resin bodies, thereby protecting the adhesion layer from excessive stress and improving both joining strength and durability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention creates a composite structure by combining multiple materials (metal body, resin body, adhesion layer, and rubber layer) with different properties. The rubber layer, positioned between the resin body and adhesion layer, provides complementary characteristics that enhance the overall performance of the laminated product, particularly in terms of stress resistance and joining strength.

Inventive Principle:
Principle #40Composite materials

2Strength

If the metal body and resin body experience thermal shrinkage, then the laminated product can be formed, but stress is applied to the adhesion layer which limits further improvement of joining strength

Engineering Contradiction:
Improvejoining strengthVSAvoidthermal stress
Core Design Contradiction:
StrengthVSStress or pressure

Solution Approach 1:

The rubber layer is positioned beforehand between the resin body and the adhesion layer to provide cushioning against thermal stress. This pre-positioned buffer absorbs the stress generated during thermal shrinkage before it reaches the adhesion layer, preventing stress concentration and enabling improved joining strength.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The invention changes the physical parameters of the interface between metal and resin by introducing a rubber layer with different elastic properties. This parameter change allows the system to accommodate thermal expansion differences more effectively, reducing thermal stress on the adhesion layer while maintaining strong joining.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If a conventional adhesion layer is used between metal and resin bodies, then the basic joining function is achieved, but the durability in high-temperature environments is insufficient

Engineering Contradiction:
ImprovedurabilityVSAvoidheat resistance
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The rubber layer acts as a thermal intermediary that protects the adhesion layer from direct exposure to extreme temperature variations. This mediator absorbs thermal stress and provides a buffer zone, enabling the laminated product to maintain durability in high-temperature environments while preserving the joining function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

By creating a composite structure that includes a rubber layer with superior thermal flexibility and stress resistance, the invention enhances the overall heat resistance and durability of the laminated product. The combination of materials with complementary thermal properties allows the assembly to withstand high-temperature conditions better than conventional single-layer adhesion systems.

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

The solution significantly improves the joining strength and durability of the laminated product, particularly in high-temperature environments, by effectively absorbing thermal stress and maintaining adhesiveness, thus enhancing the performance of airless tires.

Implementation Method 1

In general, a metal body and a resin body have different coefficients of thermal expansion. Thus, if the metal body and the resin body experience thermal shrinkage or the like, a stress is applied to an adhesion layer therebetween

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the laminated product further includes a rubber layer made from a vulcanized rubber and located between the resin body and the adhesion layer

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4397481A1Laminated product and manufacturing method therefor
Publication Date: 2024.07.10 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4397481A1 patent drawingFigure 1
  • EP4397481A1 patent drawingFigure 2(a)~2(c)
  • EP4397481A1 patent drawingFigure 3(a)~3(b)

AI summary

Provided is a laminated product in which the joining strength between a metal body and a resin body can be improved. A laminated product 1 includes a metal body 2, a resin body 3, and an adhesion layer 4, the metal body 2 and the resin body 3 being joined together with the adhesion layer 4 therebetween. The laminated product 1 further includes a rubber layer 5 made from a vulcanized rubber and located between the resin body 3 and the adhesion layer 4.