Laminated Glass Interlayer Film Recess Pattern for Deaeration and Ghosting

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Solution Overview

Problem

Laminated glass with interlayer films containing multiple resin layers experiences ghosting due to projections and recesses on the film's surface, which interfere with the interface during the production process, leading to light interference phenomena and deaeration issues.

Innovation Solution

The interlayer film features a large number of recesses and projections on at least one surface, with recesses having a groove shape and being regularly arranged in parallel, enhancing deaeration properties while preventing ghosting by optimizing the pattern and depth of these features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If projections and recesses are formed on the surface of the interlayer film to improve deaeration properties, then deaeration efficiency is improved, but ghosting occurs due to light interference at the resin layer interface

Engineering Contradiction:
Improvedeaeration efficiencyVSAvoidghosting
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The recesses are designed with specific local characteristics: groove shape with continuous bottom, regular parallel arrangement, controlled depth (10-40 μm), and specific interval (1000-1500 μm). These localized quality specifications ensure effective deaeration channels while controlling light interference to prevent ghosting.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention optimizes multiple parameters of the recesses simultaneously: depth (10-40 μm), interval (1000-1500 μm), shape (groove with continuous bottom), and arrangement (regular parallel). By carefully controlling these parameters, the design achieves both excellent deaeration properties and prevention of ghosting effects.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If recesses with groove shape and continuous bottom are regularly arranged in parallel to enhance deaeration, then deaeration properties are significantly improved, but the complexity of surface pattern design increases

Engineering Contradiction:
Improvedeaeration propertiesVSAvoidsurface pattern complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The surface is segmented into multiple identical recess units arranged in a regular parallel pattern. This segmentation approach simplifies the embossing tool design while achieving complex deaeration functionality across the entire interlayer film surface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of creating complex three-dimensional structures, the invention uses simple groove-shaped recesses with continuous bottoms. This inverted approach—using simpler geometric forms—achieves the desired deaeration effect without requiring complex surface patterns.

Inventive Principle:
Principle #13The other way round (Inversion)

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 design ensures excellent deaeration properties during the production of laminated glass and effectively suppresses ghosting, maintaining the glass's appearance and functionality.

Implementation Method 1

a laminate at least including an interlayer film for laminated glass interposed between two glass plates are passed through nip rolls for deaeration (squeeze deaeration) or put in a rubber bag and vacuum suctioned (vacuum deaeration) to be pressure-bonded while the air remaining between the glass plate and the interlayer film is removed

Methodology Applied
Scientific EffectDeaeration:

Implementation Method 2

ghosting is caused by projections and recesses formed on the surface of the interlayer film for laminated glass

Methodology Applied
Scientific EffectLight interference: Interference

Data Source

PatentEP3029002B1Laminated glass interlayer and laminated glass
Publication Date: 2020.02.26 SEKISUI CHEMICAL CO LTD
  • EP3029002B1 patent drawingFigure 1~3
  • EP3029002B1 patent drawing

AI summary

The present invention aims to provide an interlayer film for laminated glass including two or more resin layers laminated together which exhibits excellent deaeration properties in the production process of a laminated glass and prevents ghosting, and a laminated glass including the interlayer film for laminated glass. The present invention relates to an interlayer film for laminated glass including at least two resin layers laminated together, the interlayer film having a large number of recesses and a large number of projections on at least one surface, the recesses having a groove shape with a continuous bottom and being regularly arranged adjacently in parallel with one another, the surface with the large number of recesses and the large number of projections having a groove depth (Rzg) of the recesses determined in conformity with JIS B-0601(1994) of 10 to 40 µm, the recesses each having an interval from an adjacent recess of 1000 to 1500 µm.