Variable Wedge Interlayer Film for Laminated Glass Degassing

Solution Overview

Problem

Conventional wedge-shaped interlayer films for laminated glass often experience poor degassing, leading to air bubbles between the glass plates, which results in a poor appearance and increased likelihood of double images in head-up displays, particularly around the upper or lower sides of the HUD area.

Innovation Solution

An interlayer film with a thermoplastic resin, featuring a wedge-like shape with varying thickness and surface roughness, specifically designed to reduce air bubble formation by increasing the ten-point average roughness to 20 μm or more in certain regions, thereby improving degassing and reducing double images.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional wedge-shaped interlayer film is used, then double images in HUD area can be suppressed, but air bubbles are likely to remain between glass plates due to poor degassing

Engineering Contradiction:

Improvedouble image suppressionVSAvoidair bubble formation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The interlayer film employs different wedge angles in different regions: a first wedge angle in a first region and a second wedge angle different from the first in a second region. This local variation in wedge angle allows optimization of both degassing performance and double image suppression in different areas of the laminated glass

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The interlayer film is divided into multiple regions with different wedge angles, segmenting the uniform wedge structure into functionally distinct zones that address different requirements (degassing vs. double image suppression) in different areas

Inventive Principle:

Principle #1Segmentation

2Reliability

If a constant wedge angle is used in HUD area, then double images can be suppressed, but air bubbles are likely to remain due to poor degassing

Engineering Contradiction:

Improvedouble image suppressionVSAvoiddegassing quality

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The interlayer film employs different wedge angles in different regions: a first wedge angle in a first region and a second wedge angle different from the first in a second region. This local variation in wedge angle allows optimization of both degassing performance and double image suppression in different areas of the laminated glass

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The wedge angle of the interlayer film is made variable rather than constant, allowing the structure to adapt to different functional requirements in different regions, thereby improving both degassing and double image suppression

Inventive Principle:

Principle #15Dynamics

3Ease of manufacture

If the interlayer film has uniform thickness, then manufacturing is simpler, but air bubbles are likely to form and appearance deteriorates

Engineering Contradiction:

Improveinterlayer film productionVSAvoidair bubble formation

Core Design Contradiction:

Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The interlayer film employs different wedge angles in different regions: a first wedge angle in a first region and a second wedge angle different from the first in a second region. This local variation in wedge angle allows optimization of both degassing performance and double image suppression in different areas of the laminated glass

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11648754B2Interlayer for laminated glass, and laminated glass

Publication Date: 2023.05.16 SEKISUI CHEMICAL CO LTD

AI summary

An interlayer film for laminated glass is disclosed which contains a thermoplastic resin and has a portion where the amount of increase in the thickness is increased in a direction from one end to the other end in the region where the thickness is increased, or has a portion where the amount of increase in the thickness is decreased in a direction from one end to the other end in the region where the thickness is increased, and the ten-point average roughness Rz of the surface at a center position of the portion where the amount of increase in the thickness is increased, or the portion where the amount of increase in the thickness is decreased is 20 μm or more.