Resin-Metal Composite Adhesion via Buffer Treatment

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Solution Overview

Problem

The existing resin-metal composite materials, particularly those using acid-modified polyolefin and steel cords, fail to achieve sufficient adhesive strength between the resin and metal materials, limiting the durability of resin tires reinforced with metal components.

Innovation Solution

A resin-metal composite material is developed by surface-treating the metal material with a buffer solution of pH 5 to 7.2, followed by treatment with an aqueous heterocyclic compound solution, using a thermoplastic resin with polar groups, such as maleic acid-modified polyolefin, to enhance adhesion, ensuring a copper-to-zinc ratio of 55 to 95% on the metal surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If acid-modified polyolefin and steel cord are used as resin material and reinforcing metal material, then the composite material can be manufactured with ease, but the adhesive strength between resin and metal is insufficient

Engineering Contradiction:
Improveease of manufactureVSAvoidadhesive strength
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The metal material surface is subjected to preliminary treatment with a buffer solution before being combined with the resin material. This preliminary action modifies the surface properties of the metal, creating conditions that enhance adhesion without complicating the overall manufacturing process. The buffer solution treatment prepares the metal surface to better bond with the acid-modified polyolefin resin.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the pH parameter of the treatment solution to specifically use a buffer solution within pH 5-7, which optimizes the surface treatment conditions. This parameter change in the treatment environment enables the metal surface to achieve optimal adhesion properties when combined with the resin material, resolving the contradiction between ease of manufacture and adhesive strength.

Inventive Principle:
Principle #35Parameter changes

2Strength

If conventional thermosetting adhesives are used to bond resin and metal materials, then high adhesive strength is achieved, but the manufacturing complexity and cost increase

Engineering Contradiction:
Improveadhesive strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The invention extracts and removes the need for separate adhesive materials and their associated complex application processes. By incorporating adhesion-promoting functionality directly into the buffer solution treatment step, the system eliminates the need for additional adhesive layers and complex bonding equipment, thereby reducing manufacturing complexity while maintaining high adhesive strength.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The buffer solution acts as an intermediary substance that facilitates bonding between the metal material and resin material without requiring separate adhesive materials. This intermediary treatment creates surface conditions that enable direct, strong bonding, simplifying the manufacturing process while achieving adhesive strength comparable to or exceeding conventional thermosetting adhesives.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If steel cord is coated with elastomer-containing thermoplastic elastomer composition, then corrosion resistance and bending resistance are improved, but adhesion between resin and metal remains insufficient

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidadhesion between resin and metal
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention applies local quality modification by treating only the surface layer of the metal material with the buffer solution, while maintaining the bulk properties and protective coatings (such as elastomer layers) intact. This localized surface treatment enhances adhesion without compromising the corrosion resistance and bending resistance provided by the elastomer coating, thereby resolving the contradiction between reliability and adhesion strength.

Inventive Principle:
Principle #3Local quality

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 approach significantly improves the adhesion between the resin and metal materials, resulting in a resin-metal composite with enhanced durability and adhesive strength comparable to or exceeding conventional thermosetting adhesives, leading to a more durable tire.

Implementation Method 1

the surface of the metal material is treated with a buffer solution having a pH of from 5 to 7.2, and an abundance ratio of copper to a total amount of copper and zinc (Cu/(Cu + Zn) × 100) in the surface of the metal material is from 55 to 95% by mass

Methodology Applied
Scientific EffectBuffer solution treatment:

Implementation Method 2

a resin material including, as a main component, a thermoplastic resin having a polar group... significantly improves the adhesion between the resin and metal materials

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3130693B1Resin-metal composite material and tire using same
Publication Date: 2018.07.25 BRIDGESTONE CORP
  • EP3130693B1 patent drawingFigure 1A~1B

AI summary

Provided is a resin-metal composite material that ensures high adhesion between a resin material and a metal material. Additionally provided is a tire that achieves high durability by using the resin-metal composite material. The resin-metal composite material includes a metal material and a resin material that coats at least a part of the surface of the metal material. The resin material includes, as a main component, a thermoplastic resin having a polar group. The surface of the metal material is treated with a buffer solution having a pH of from 5 to 7.2, and an abundance ratio of copper to a total amount of copper and zinc (Cu/(Cu + Zn) × 100) in the surface of the metal material is from 55 to 95% by mass. The tire includes a circular tire frame formed of a resin material and a reinforcing layer composed of a reinforcing member wound around an outer circumference of the tire frame, in which the reinforcing member includes the resin-metal composite material.