Polyvinyl Acetal Interlayer Adhesion to Glass

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Solution Overview

Problem

Polyvinyl butyral (PVB) interlayers in multiple layer panels face adhesion issues, particularly in hot and humid environments, leading to edge delamination and reduced mechanical, optical, and acoustic performance.

Innovation Solution

A poly(vinyl acetal) resin interlayer with a peel adhesion retention of at least 25% after exposure to 95% relative humidity at 50°C for 1 week, treated with a coating material containing a silanol-containing adhesion stabilizing agent or its precursor, enhancing adhesion to glass and other inorganic surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PVB is used in hot and humid environments, then the panel can provide basic adhesion and functionality, but moisture ingress leads to edge delamination and reduced performance

Engineering Contradiction:
Improveadhesion retentionVSAvoidmoisture ingress
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A silane-based adhesion promoter is applied as an intermediary layer between the PVB interlayer and the glass substrate. This promoter forms a chemical bridge that resists moisture ingress and prevents delamination, maintaining adhesion retention of at least 25% after exposure to 95% relative humidity at 50°C for one week.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the surface chemistry parameters of the PVB interlayer by treating it with silane compounds. This changes the surface energy and chemical composition, creating a more moisture-resistant interface that maintains adhesion under hot and humid conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the interlayer is treated with adhesion promoter, then adhesion to inorganic surfaces is enhanced, but additional processing steps and cost are incurred

Engineering Contradiction:
Improvesurface adhesionVSAvoidprocessing steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The adhesion promoter is applied in advance to the PVB interlayer surface before lamination. This preliminary treatment ensures that the adhesion-enhancing properties are already in place before the interlayer is bonded to the glass substrates, simplifying the overall manufacturing process.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The silane-based adhesion promoter is designed to self-adhere to the PVB surface and self-crosslink upon exposure to moisture or heat, reducing the need for additional processing steps such as curing cycles or specialized application equipment.

Inventive Principle:
Principle #25Self-service

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 poly(vinyl acetal) resin interlayers exhibit improved adhesion retention and reduced peel adhesion loss, maintaining strong bonding to substrates even under high moisture and temperature conditions, suitable for various applications including automotive and architectural uses.

Implementation Method 1

treated with a coating material containing a silanol-containing adhesion stabilizing agent or its precursor, enhancing adhesion to glass and other inorganic surfaces

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Data Source

PatentEP3230367B1Poly(vinyl acetal) sheets exhibiting enhanced adhesion to inorganic surfaces and corresponding method
Publication Date: 2021.06.16 SOLUTIA INC
  • EP3230367B1 patent drawingFigure 1
  • EP3230367B1 patent drawingFigure 2~3
  • EP3230367B1 patent drawingFigure 4

AI summary

Resin layers and interlayers exhibiting enhanced adhesion to inorganic surfaces, such as glass, are provided. In some cases, the layers and interlayers may comprise at least one adhesion stabilizing agent for improving adhesion to various surfaces, even in the presence of moisture. Such layers and interlayers may be useful, for example, in multiple layer panels, such as, for example, safety glass used in automotive and architectural applications.