Highly Saturated Nitrile Rubber Adhesive for Automotive Composites

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Solution Overview

Problem

Existing adhesive compositions for highly saturated nitrile rubber composites with fiber base materials lack sufficient stretchability and abrasion resistance, failing to meet the demands of high-performance engine compartments in automobiles.

Innovation Solution

A latex of highly saturated nitrile rubber with specific molecular weight and viscoelastic properties, combined with a resorcinol formaldehyde resin, is used to create an adhesive composition that forms a layer with improved stretchability and abrasion resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a carboxyl group-containing highly saturated nitrile rubber latex and resorcinol formaldehyde resin are used as adhesive composition, then the bonding strength of rubber and base fabric is improved, but the abrasion resistance is insufficient

Engineering Contradiction:
Improvebonding strengthVSAvoidabrasion resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the weight average molecular weight of solubles in chloroform to 100,000 or less, and adjusting the loss tangent tan δ(50° C.) to 0.3 to 0.6 and complex torque S* to 20 dNm or less. These parameter optimizations resolve the contradiction by achieving both sufficient bonding strength and improved abrasion resistance through molecular weight and viscoelastic property control.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite adhesive system combining highly saturated nitrile rubber latex with specific molecular weight characteristics and resorcinol formaldehyde resin. This composite material approach allows the rubber component to provide bonding strength while the resin component enhances abrasion resistance, thereby resolving the technical contradiction between these two properties.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the weight average molecular weight of solubles in chloroform is reduced to 100,000 or less, then the stretchability and abrasion resistance are improved, but the bonding strength may be compromised

Engineering Contradiction:
Improveabrasion resistanceVSAvoidbonding strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent resolves this contradiction through parameter changes by simultaneously optimizing multiple parameters: weight average molecular weight of solubles in chloroform (100,000 or less), loss tangent tan δ(50° C.) (0.3 to 0.6), and complex torque S* (20 dNm or less). This multi-parameter optimization ensures that bonding strength is maintained while achieving improved stretchability and abrasion resistance.

Inventive Principle:
Principle #35Parameter changes

3Strength

If solvent-based rubber glue is used for treating base fabric, then the bonding strength is improved, but environmental pollution occurs

Engineering Contradiction:
Improvebonding strengthVSAvoidenvironmental pollution
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful solvent-based system into a beneficial aqueous system by using highly saturated nitrile rubber latex with controlled molecular weight properties. This transformation eliminates organic solvent pollution while maintaining bonding strength through precise control of the rubber latex parameters, particularly weight average molecular weight of solubles in chloroform and viscoelastic properties.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent substitutes the solvent-based chemical system with an aqueous rubber latex system. By replacing organic solvents with water as the carrier and using controlled molecular weight rubber solubles, the invention eliminates environmental pollution while maintaining adhesive performance through parameter-optimized rubber properties.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 adhesive composition enhances the stretchability and abrasion resistance of fiber base material-highly saturated nitrile rubber composites, making them suitable for high-performance applications in automotive components.

Implementation Method 1

an adhesive composition which can form an adhesive layer excellent in stretchability and abrasion resistance

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentUS11365331B2Latex of the highly saturated nitrile rubber and adhesive composition
Publication Date: 2022.06.21 ZEON CORP

AI summary

A latex of a highly saturated nitrile rubber wherein the highly saturated nitrile rubber contains α,β-ethylenically unsaturated nitrile monomer units in a ratio of 10 to 60 wt %, has an iodine value of 120 or less, and has a weight average molecular weight of solubles in chloroform of 100,000 or less, and when removing volatiles contained in the latex and making a film of the highly saturated nitrile rubber, a loss tangent tan δ(50° C.) at 50° C. of the film is 0.3 to 0.6 and a complex torque S* at the time of 100% shear strain at 100° C. of the film is 20 dNm or less, and an adhesive composition containing the latex are provided.