Silica-Rubber Tire Cord Coating for Hygrothermal Durability

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Solution Overview

Problem

The durability of tires is not adequately improved by existing technologies, particularly in terms of longevity and resistance to hygrothermal aging, despite the use of elongated steel elements with ternary alloy coatings.

Innovation Solution

A tire design featuring a steel cord with a ternary plated layer of copper, zinc, and cobalt, combined with a topping rubber composition that includes silica and a specific ratio of zinc content, enhancing adhesion and fuel efficiency, and incorporating a thermosetting resin and cobalt compound to improve durability and resistance to hygrothermal aging.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a steel cord is provided with a ternary plated layer consisting of copper, zinc, and cobalt, and the topping rubber contains silica with a specific Y/X ratio (0.50 or more), then the durability and resistance to hygrothermal aging of the tire are improved, but the manufacturing complexity and cost increase due to precise compositional control requirements

Engineering Contradiction:
Improvedurability and resistance to hygrothermal agingVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the chemical composition parameters of the plated layer (copper, zinc, cobalt ratios) and the rubber composition (silica content Y relative to zinc content X, with Y/X ≥ 0.50). By optimizing these parameters, the invention achieves improved durability and hygrothermal aging resistance while providing clear guidance for manufacturing control.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses a composite structure consisting of a steel cord with a ternary plated layer (copper-zinc-cobalt) combined with a silica-containing rubber composition. This composite material system synergistically improves adhesion, durability, and resistance to hygrothermal aging, resolving the contradiction between performance improvement and manufacturing complexity.

Inventive Principle:
Principle #40Composite materials

2Strength

If the topping rubber composition includes silica with high content (Y/X ≥ 0.50), then adhesion and fuel efficiency are enhanced, but the manufacturing precision requirements increase to maintain the specific ratio

Engineering Contradiction:
ImproveadhesionVSAvoidcompositional ratio control
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The invention specifies a quantitative relationship between silica content (Y) and zinc content (X) in the form of a ratio Y/X ≥ 0.50. This parameter specification enables manufacturers to control adhesion properties by maintaining a clear numerical threshold, balancing performance enhancement with manufacturability.

Inventive Principle:
Principle #35Parameter changes

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 tire exhibits improved durability and resistance to hygrothermal aging, with enhanced adhesion and fuel efficiency due to the specific ternary plating and rubber composition, leading to a longer tire lifespan and better performance under severe conditions.

Implementation Method 1

the steel cord is provided with a ternary plated layer consisting of copper, zinc, and cobalt

Methodology Applied
Scientific EffectElectroplating: Electroplating

Implementation Method 2

improve durability and resistance to hygrothermal aging

Methodology Applied
Scientific EffectCorrosion resistance: Crevice Corrosion

Implementation Method 3

the topping rubber is composed of a rubber composition comprising a rubber component and silica... enhanced adhesion

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 4

incorporating a thermosetting resin and cobalt compound to improve durability

Methodology Applied
Scientific EffectVulcanization: Chemical Bonding

Data Source

PatentEP4282914A1tire
Publication Date: 2023.11.29 SUMITOMO RUBBER INDUSTRIES LTD
  • EP4282914A1 patent drawingFigure 1
  • EP4282914A1 patent drawingFigure 2
  • EP4282914A1 patent drawingFigure 3

AI summary

A tire comprising a steel cord and a topping rubber covering the steel cord, wherein the steel cord is provided with a ternary plated layer consisting of copper, zinc, and cobalt, wherein the topping rubber is composed of a rubber composition comprising a rubber component and silica, and wherein, when a content of zinc in the ternary plated layer is defined as X (% by mass) and a content of silica based on 100 parts by mass of the rubber component is defined as Y (part by mass), Y/X is 0.50 or more.