Epichlorohydrin Rubber Laminate Bonding via Maleimide Mediator

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Solution Overview

Problem

Existing rubber-thermoplastic resin laminates face challenges in achieving sufficient adhesive strength between dissimilar polymer materials, particularly between epichlorohydrin-based rubber and thermoplastic resin, which are essential for fuel-resistant applications but often require high amounts of adhesive activators, leading to processing difficulties and reduced practical use.

Innovation Solution

A vulcanized rubber laminate is created by bonding an unvulcanized epichlorohydrin-based rubber composition layer containing a maleimide compound, a vulcanizing agent, and an acid acceptor with a thermoplastic resin layer, using specific compounds and processes to enhance adhesiveness without compromising the rubber's elastic modulus.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thermoplastic resin layer having excellent fuel barrier properties and an epichlorohydrin-based rubber layer are bonded together, then fuel permeation resistance is improved, but adhesiveness between the dissimilar materials is insufficient

Engineering Contradiction:
Improvefuel permeation resistanceVSAvoidadhesiveness between layers
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

A maleimide compound is introduced as an intermediary substance between the thermoplastic resin layer and the epichlorohydrin-based rubber layer. This maleimide compound acts as a chemical mediator that enhances interfacial bonding by reacting with both the thermoplastic resin and the rubber, creating strong chemical bonds at the interface and significantly improving adhesiveness while maintaining fuel barrier properties.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The chemical composition parameters of the rubber layer are modified by incorporating specific compounds: a maleimide compound (0.1-10 parts by weight per 100 parts rubber), an acid acceptor (0.1-10 parts by weight), and a vulcanizing agent (0.1-5 parts by weight). These parameter changes enable chemical bonding with the thermoplastic resin while preserving the rubber's elastic properties and the laminate's fuel resistance.

Inventive Principle:
Principle #35Parameter changes

2Strength

If a large amount of adhesive activator is mixed to firmly bond the thermoplastic resin and epichlorohydrin-based rubber, then adhesiveness is improved, but processing becomes difficult

Engineering Contradiction:
Improveadhesiveness between layersVSAvoidprocessability
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The dosage of the maleimide compound is precisely controlled within a specific range (0.1-10 parts by weight per 100 parts rubber). This optimized parameter range achieves sufficient adhesiveness through efficient chemical bonding while preventing excessive viscosity increase and maintaining good processability during mixing and molding operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The rubber composition is formulated as a composite system containing multiple components in specific proportions: epichlorohydrin-based rubber, maleimide compound, acid acceptor, and vulcanizing agent. This composite formulation creates synergistic effects where each component contributes to both bonding strength and processability, avoiding the need for excessive adhesive activators.

Inventive Principle:
Principle #40Composite materials

3Strength

If the epichlorohydrin-based rubber composition contains a maleimide compound, a vulcanizing agent and an acid acceptor, then adhesiveness to thermoplastic resin is significantly improved, but composition complexity increases

Engineering Contradiction:
Improveadhesiveness between layersVSAvoidcomposition complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The maleimide compound serves multiple functions simultaneously: it acts as an adhesive promoter by reacting with the thermoplastic resin, serves as a crosslinking agent for the rubber matrix, and functions as a bonding bridge between the resin and rubber layers. This multi-functionality reduces the need for separate additives and simplifies the overall composition despite the enhanced bonding performance.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The adhesive promoter, crosslinking agent, and bonding bridge functions are merged into a single maleimide compound system. By combining these multiple roles into one compound, the composition complexity is minimized while achieving superior interlayer bonding between the thermoplastic resin and epichlorohydrin-based rubber layers.

Inventive Principle:
Principle #5Merging (Combining)

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 resulting laminate exhibits excellent adhesiveness and firm bonding between the rubber and resin layers, making it suitable for applications requiring gasoline permeation resistance, aging resistance, and weatherability, such as fuel hoses and filler hoses.

Implementation Method 1

an unvulcanized epichlorohydrin-based rubber composition layer containing a maleimide compound, a vulcanizing agent and an acid acceptor, and a thermoplastic resin layer are heated and bonded

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

a vulcanized rubber laminate in which an unvulcanized epichlorohydrin-based rubber composition layer containing a maleimide compound, a vulcanizing agent and an acid acceptor, and a thermoplastic resin layer are heated and bonded

Methodology Applied
Scientific EffectVulcanization: Chemical Bonding

Data Source

PatentUS8920894B2Rubber-resin laminate
Publication Date: 2014.12.30 OSAKA SODA CO LTD

AI summary

Disclosed is a vulcanized rubber laminate, wherein a thermoplastic resin layer and an unvulcanized epichlorohydrin rubber composition layer containing a specific maleimide compound, vulcanizing agent, and acid acceptor are heated and bonded. Specifically disclosed is a laminate configured by heating and bonding an unvulcanized epichlorohydrin rubber composition layer (A) and a thermoplastic resin (B), wherein the unvulcanized epichlorohydrin rubber composition contains: an epichlorohydrin rubber (a), a compound containing one or more maleimide group within the molecule (b), a vulcanizing agent (c), and an acid acceptor (d).