Laminated Glass Interlayer Film Near-Infrared Absorption

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Solution Overview

Problem

Conventional interlayer films for laminated glass containing ITO or ATO particles fail to adequately absorb near-infrared rays, limiting the enhancement of heat insulation properties, and struggle to achieve both low Total Solar Transmittance (Tts) and high visible transmittance simultaneously, which is necessary for compliance with energy efficiency standards like the Cool Cars Standards.

Innovation Solution

An interlayer film comprising a polyvinyl acetal resin, plasticizer, heat insulating particles, and compounds such as phthalocyanine or naphthalocyanine, with specific weight ratios and amounts, to enhance heat insulation and visible transmittance, allowing for the production of laminated glass that meets stringent energy efficiency requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If ITO particles or ATO particles are added to the interlayer film, then heat insulation property is improved, but near-infrared ray absorption is insufficient

Engineering Contradiction:
Improveheat insulation propertyVSAvoidnear-infrared ray absorption
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent combines ITO or ATO particles with organic infrared absorbing compounds (phthalocyanine, naphthalocyanine, or anthracyanine) to create a composite interlayer film. This composite approach allows the inorganic particles to provide basic heat insulation while the organic compounds specifically enhance near-infrared absorption, thereby resolving the insufficiency of near-infrared ray absorption when using only ITO or ATO particles.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent specifies precise compositional parameters: the organic compound content is 0.01-5 parts by weight per 100 parts by weight of thermoplastic resin, and the ITO or ATO particle content is 0.1-10 parts by weight per 100 parts by weight of thermoplastic resin. By controlling these parameters within specific ranges, the patent optimizes both heat insulation property and near-infrared absorption, achieving compliance with Cool Cars Standards.

Inventive Principle:
Principle #35Parameter changes

2Loss of energy

If heat reflecting PET is used to reflect infrared rays, then heat insulation is improved, but communication waves are also reflected

Engineering Contradiction:
Improveheat insulationVSAvoidcommunication wave transmission
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent uses organic infrared absorbing compounds that specifically target the infrared region of the electromagnetic spectrum. These compounds have absorption characteristics localized to infrared wavelengths, allowing them to absorb heat rays while transmitting communication waves (radio frequencies) and visible light, thereby achieving selective spectral control.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent employs organic compounds (phthalocyanine, naphthalocyanine, anthracyanine) that can be incorporated into the interlayer film at low concentrations (0.01-5 parts by weight per 100 parts resin). These organic additives provide effective infrared absorption without the need for expensive metallic coatings or complex multi-layer structures, offering a cost-effective solution.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Loss of energy

If Total Solar Transmittance is reduced to meet Cool Cars Standards, then heat insulation is improved, but visible transmittance may be compromised

Engineering Contradiction:
ImproveTotal Solar Transmittance reductionVSAvoidvisible transmittance
Core Design Contradiction:
Loss of energyVSIllumination intensity

Solution Approach 1:

The patent uses organic infrared absorbing compounds at very low concentrations (0.01-5 parts by weight per 100 parts thermoplastic resin). This low dosage is sufficient to absorb infrared radiation while having minimal impact on visible light transmission, allowing the interlayer film to reduce Tts to meet Cool Cars Standards while maintaining high visible transmittance for adequate illumination.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The organic compounds (phthalocyanine, naphthalocyanine, anthracyanine) have specific absorption characteristics in the infrared region while remaining relatively transparent in the visible region. This selective optical property allows the patent to modify the solar transmission profile by absorbing infrared energy without significantly altering visible light transmission, thus maintaining good illumination properties.

Inventive Principle:
Principle #32Color changes

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 interlayer film effectively reduces Total Solar Transmittance while maintaining high visible transmittance, enabling compliance with energy efficiency standards and providing improved heat insulation performance.

Implementation Method 1

at least one compound selected from the group consisting of a phthalocyanine compound, a naphtalocyanine compound, and an anthracyanine compound

Methodology Applied
Scientific EffectInfrared absorption: Absorption (EM radiation)

Implementation Method 2

infrared rays having a wavelength of 780 nm or more... infrared rays have a large thermal effect and are released as heat once absorbed in a substance

Methodology Applied
Scientific EffectVibrational energy transition:

Implementation Method 3

heat insulating particles

Methodology Applied
Scientific EffectThermal radiation absorption: Absorption (EM radiation)

Implementation Method 4

heat insulating particles

Methodology Applied
Scientific EffectThermal scattering: Scattering

Implementation Method 5

a polyvinyl acetal resin; a plasticizer

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP2692708B1Intermediate film for laminated glass, and laminated glass
Publication Date: 2015.03.04 SEKISUI CHEMICAL CO LTD
  • EP2692708B1 patent drawingFigure 1
  • EP2692708B1 patent drawing

AI summary

The present invention provides an interlayer film for laminated glass which provides a laminated glass with excellent heat insulation property and high visible transmittance. An interlayer film 2 for laminated glass of the present invention comprises: a thermoplastic resin; a plasticizer; heat insulating particles; and at least one compound selected from the group consisting of a phthalocyanine compound, a naphtalocyanine compound, and an anthracyanine compound. When an amount A represents the amount of the heat insulating particles to 100 parts by weight of the thermoplastic resin and an amount B represents the amount of the compound to 100 parts by weight of the thermoplastic resin, the amount A is 0.1 to 3 parts by weight and a ratio of the amount A to the amount B (the amount A/ the amount B) is 3 to 2000.