Tire Inner Liner Surface Treatment for Post-Cure Adhesion

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Solution Overview

Problem

The polysiloxane-containing release treatments applied to the inner liner of tires to prevent sticking during the curing process remain on the surface after curing, inhibiting the adhesion of other materials, such as adhesives and sealants.

Innovation Solution

Treating the lower surface of the cured inner liner to convert polysiloxane moieties to silanol moieties, either by irradiation or oxidation, increasing the hydrophilicity and adherability of the surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If polysiloxane-containing release treatment is applied to the inner liner surface, then sticking prevention during curing is improved, but adhesion of adhesives and sealants after curing deteriorates

Engineering Contradiction:
Improvesticking prevention during curingVSAvoidadhesion of adhesives and sealants
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention changes the chemical state of the polysiloxane surface by converting it from a hydrophobic, adhesive-resistant state to a hydrophilic, adhesive-receptive state through oxidation or plasma treatment. This parameter change allows the same surface to first prevent sticking during curing, then accept adhesives after curing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention applies a preliminary release treatment with polysiloxane before curing to prevent sticking, then performs a secondary treatment (oxidation or plasma) after curing to prepare the surface for adhesive application. This two-stage preliminary action sequence resolves the contradiction between sticking prevention and subsequent adhesion.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If polysiloxane release agent remains on the inner liner surface after curing, then sticking prevention is maintained, but surface hydrophilicity and adherability deteriorate

Engineering Contradiction:
Improvesticking preventionVSAvoidsurface adherability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention changes the surface energy and chemical composition parameters of the polysiloxane layer through oxidation or plasma treatment, transforming it from a low-energy, hydrophobic surface to a high-energy, hydrophilic surface that readily accepts adhesives while maintaining the underlying sticking prevention function.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses oxidation or plasma treatment as an intermediary process that modifies the polysiloxane surface properties. This intermediary treatment creates a transition state where the surface becomes receptive to adhesives without removing the polysiloxane release agent that provides sticking prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 treated surface allows for improved adhesion of adhesives and other materials, enhancing the integration of components within the tire, such as noise barriers and sealant layers, without the limitations of the original release treatments.

Implementation Method 1

treating the lower surface of the cured inner liner to convert at least a portion of the polysiloxane moieties to silanol moieties

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

treating the lower surface of the cured inner liner to increase its hydrophilicity by oxidizing at least a portion of the polysiloxane moieties

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentUS12030350B2Methods for treating inner liner surface, inner liners resulting therefrom and tires containing such inner liners
Publication Date: 2024.07.09 BRIDGESTONE AMERICAS TIRE OPERATIONS LLC

AI summary

Methods for treating the surface of a cured inner liner are disclosed. By use of these methods a treated, cured inner liner is produced which has a lower surface with increased adherability to other materials (e.g., adhesives). Treated, cured inner liners resulting from such methods as well as tires containing the treated inner liners.