Carbon Fiber Cord Coating for Fatigue-Resistant Rubber Reinforcement

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Solution Overview

Problem

Carbon fibers used as reinforcing fibers in rubber products face challenges with low bending fatigue resistance and adhesion to the matrix rubber, necessitating a solution that enhances both properties.

Innovation Solution

A carbon fiber cord with a bundle of carbon filaments coated by a phenolic resin-based first layer and a rubber-containing second layer, where the mass ratio of the first coating layer to the total mass is between 0.5% to 10%, improving abrasion resistance and adhesion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If carbon fibers are used as reinforcing fibers, then high strength and high elastic modulus are achieved, but bending fatigue resistance is insufficient

Engineering Contradiction:
ImprovestrengthVSAvoidbending fatigue resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent applies composite materials by combining carbon fibers with a specific coating system consisting of a phenolic resin base coat and a rubber-containing top coat. This composite structure allows the carbon fiber to provide high strength while the coating layers provide bending fatigue resistance, resolving the contradiction between strength and reliability.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical and physical parameters of the fiber surface by applying specific coating materials. The phenolic resin base coat and rubber-containing top coat modify the surface properties of carbon fibers, improving their bending fatigue resistance while maintaining their inherent strength characteristics.

Inventive Principle:
Principle #35Parameter changes

2Strength

If carbon fibers are used as reinforcing fibers, then high strength is achieved, but adhesion to matrix rubber is insufficient

Engineering Contradiction:
ImprovestrengthVSAvoidadhesion to matrix rubber
Core Design Contradiction:
StrengthVSUse of energy by moving object

Solution Approach 1:

The patent uses composite materials by creating a multi-layer coating system on carbon fibers. The phenolic resin base coat provides a strong bond to the carbon fiber, while the rubber-containing top coat ensures good adhesion to the matrix rubber, thus maintaining strength while improving adhesion.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent introduces an intermediary coating system between the carbon fiber and the matrix rubber. This intermediate layer acts as a mediator that improves the bond between the carbon fiber and the rubber matrix, resolving the adhesion problem while preserving the strength benefits of carbon fibers.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by moving object

If glass fibers are used as reinforcing fibers, then adhesion to matrix rubber is adequate, but high strength and high elastic modulus requirements cannot be met

Engineering Contradiction:
Improveadhesion to matrix rubberVSAvoidstrength
Core Design Contradiction:
Use of energy by moving objectVSStrength

Solution Approach 1:

The patent applies composite materials by combining carbon fibers (for high strength) with a coating system that includes rubber components (for good adhesion). This composite approach allows the reinforcement to achieve both high strength and adequate adhesion, overcoming the limitations of glass fibers.

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 carbon fiber cord achieves high bending fatigue resistance and increased adhesion to the matrix rubber, making it suitable for high-performance applications like timing belts for vehicle engines.

Implementation Method 1

a first coating layer formed on the bundle of carbon filaments. The first coating layer contains a phenolic resin and does not contain a rubber component

Methodology Applied
Scientific EffectPhenolic resin coating: Coatings

Implementation Method 2

a second coating layer formed over the first coating layer. The second coating layer contains a rubber component and is formed using a treatment agent containing the rubber component

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2952625B1Carbon fiber cord for reinforcing rubber product and rubber product using same
Publication Date: 2019.03.27 NIPPON SHEET GLASS CO LTD
  • EP2952625B1 patent drawingFigure 1

AI summary

The present invention provides a carbon fiber cord having both high bending fatigue resistance and high adhesiveness. The disclosed carbon fiber cord is a carbon fiber cord for reinforcing a rubber product. This carbon fiber cord includes a carbon fiber, a first coating layer formed on the carbon fiber, and a second coating layer formed over the first coating layer. The first coating layer contains a phenolic resin and does not contain a rubber component. The second coating layer contains a rubber component. The mass ratio of the first coating layer to the total mass of the carbon fiber and the first coating layer is in a range of 0.5% to 10%.