Tire Vulcanization Bladder Primer Layer Adhesion

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Solution Overview

Problem

The existing tire vulcanization bladders with a coating layer face issues with peeling off, leading to reduced productivity due to inadequate adhesion between the bladder body and the coating layer, especially when using butyl rubber and silicone components.

Innovation Solution

A tire vulcanization bladder with a multilayer structure comprising a butyl rubber bladder body, a primer layer formed from a silane compound with an alkoxy and amino group, and a coating layer made from a silicone release agent, which enhances adhesion and prevents peeling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a coating layer containing silicone is applied directly on a butyl rubber bladder body, then the release function is achieved, but the adhesion between layers is insufficient causing peeling off

Engineering Contradiction:
Improverelease functionVSAvoidadhesion between coating layer and bladder body
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent introduces a primer layer as an intermediary between the butyl rubber bladder body and the silicone coating layer. This primer layer contains silane coupling agents that chemically bond to both the rubber substrate and the silicone coating, creating a strong adhesive bridge that prevents peeling while maintaining the release function of the outer coating layer.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite multilayer structure combining butyl rubber, silane-based primer, and silicone coating layer. Each layer is specifically designed to interact with adjacent layers through chemical bonding, forming a composite material system where the synergistic effects of different materials achieve both strong adhesion and effective release functionality.

Inventive Principle:
Principle #40Composite materials

2Productivity

If the coating layer peels off after repeated vulcanization, then the bladder becomes unusable requiring exchange, but this reduces productivity

Engineering Contradiction:
Improvebladder reusabilityVSAvoidbladder service life
Core Design Contradiction:
ProductivityVSDuration of action of stationary object

Solution Approach 1:

The primer layer acts as a durable intermediary that anchors the coating layer to the bladder body through chemical bonding. This strong adhesion prevents coating delamination during repeated thermal cycling and mechanical stress of multiple vulcanization cycles, extending the bladder's service life and maintaining high productivity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies the primer layer in advance before applying the coating layer, allowing the primer to fully cure and form a stable bonding interface. This preliminary action ensures that when the coating layer is subsequently applied and cured, it adheres strongly to the pre-prepared primer layer, preventing future peeling during repeated use.

Inventive Principle:
Principle #10Preliminary action

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 interposed primer layer improves the adhesiveness between the coating layer and the bladder body, effectively preventing separation and enhancing the peeling resistance, thus improving productivity by extending the bladder's usability.

Implementation Method 1

the silane compound having an alkoxy group and an amino group is interposed between the coating layer and the bladder body... the alkoxy group reacts with the silicone component contained in the coating layer and exhibits excellent adhesiveness, and the amino group reacts with the butyl rubber constituting the bladder body and exhibits excellent adhesiveness

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

the alkoxy group reacts with the silicone component contained in the coating layer and exhibits excellent adhesiveness

Methodology Applied
Scientific EffectSilane coupling: Chemical Bonding

Implementation Method 3

the amino group reacts with the butyl rubber constituting the bladder body and exhibits excellent adhesiveness

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Data Source

PatentEP4000850B1Tire vulcanization bladder
Publication Date: 2024.09.11 THE YOKOHAMA RUBBER CO LTD
  • EP4000850B1 patent drawingFigure 1
  • EP4000850B1 patent drawingFigure 2
  • EP4000850B1 patent drawing

AI summary

To provide a tire vulcanization bladder that includes a coating layer formed from a release agent and that makes it possible to improve productivity by suppressing peeling off of the coating layer. A primer layer (21b) is provided on an outer surface of a bladder body (21a), a coating layer (21c) is provided on an outer side of the primer layer (21b), the bladder body (21a) is formed from a rubber composition containing 50 mass% or more of a butyl rubber in a rubber component, the coating layer (21c) is formed from a release agent containing a silicone component, and the primer layer (21b) is formed from a silane compound having an alkoxy group and an amino group.