Laminated Glass with Thin-Film Stack for Symmetrical Color

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Solution Overview

Problem

Existing methods for producing colored glass articles are costly and limited in terms of color shades, with tinting times being too long for small series production and laminated glazing being expensive, while also suffering from parasitic colored reflections and asymmetrical appearances.

Innovation Solution

A laminated glass article is created by bonding a first glass sheet coated with a stack of thin layers, comprising a discontinuous metallic layer and a dielectric overlayer, to a second glass sheet using a colorless lamination interlayer, allowing for adjustable and reproducible transmission coloring and symmetrical appearance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a single coated glass sheet is used to achieve coloration, then color production is simple, but the appearance is asymmetrical and reflection tint is excessive

Engineering Contradiction:
Improvecolor production simplicityVSAvoidappearance symmetry
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The glass article is divided into multiple sheets (first and second glass sheets) with the thin-layer coating applied to only one sheet. This segmentation allows the colored transmission effect to be achieved while the second uncoated sheet compensates for reflection asymmetry, creating overall symmetrical appearance when viewed from either side.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thin-layer coating is applied locally to only one of the two glass sheets rather than both. This local quality approach allows the coated sheet to provide coloration while the uncoated second sheet provides optical balance, resolving the asymmetry issue without requiring complex coating of both surfaces.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If transition metal oxides are added during glass manufacture to tint glass, then coloration is achieved, but production time increases significantly for small series

Engineering Contradiction:
Improvecolor varietyVSAvoidproduction speed
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The coloring function is performed in advance by depositing thin layers during the lamination process rather than during glass manufacturing. This preliminary action on the interlayer allows color to be introduced at a later stage when production requirements are known, enabling small series production with multiple colors without requiring long transition times in glass furnaces.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The lamination interlayer serves as an intermediary medium that carries the coloring function. Instead of adding colorants directly to the glass melt (which requires long processing times), the thin layers are deposited on the interlayer, which then transmits the color effect when laminated between glass sheets, dramatically reducing production time.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If colored lamination interlayer is used to laminate colorless glass sheets, then coloration is achieved, but production cost increases significantly

Engineering Contradiction:
Improvecolor capabilityVSAvoidproduction cost
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Instead of using expensive pre-colored interlayers, the invention uses thin layers deposited on a standard clear interlayer. The thin layers (metallic and dielectric) are applied in a controlled manner during lamination, providing coloration at lower cost than factory-prepared colored interlayers, while maintaining the ability to produce various shades.

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

Solution Approach 2:

The solution combines clear glass sheets with a clear interlayer that has thin metallic and dielectric layers deposited on it. This composite structure creates the colored transmission effect through the optical interaction of the thin layers with light, avoiding the need for expensive uniformly colored interlayer materials while achieving versatile coloration.

Inventive Principle:
Principle #40Composite materials

4Manufacturing precision

If thin layers are deposited on the interlayer, then transmission color is homogeneous and adjustable, but the process complexity increases

Engineering Contradiction:
Improvecolor homogeneityVSAvoidcoating process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention controls color characteristics by precisely adjusting parameters of the thin layers, specifically the thickness of the metallic layer (5-50 nm) and dielectric overlayer (50-200 nm). By changing these dimensional parameters, different colors and shades can be achieved with homogeneous appearance, providing manufacturing precision through parameter control rather than material variation.

Inventive Principle:
Principle #35Parameter 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

This approach enables a wide range of color shades with reduced reflection tint, improving the glass article's appearance and production efficiency by using a stack of thin layers to achieve homogeneous and symmetrical color, independent of the viewing side.

Implementation Method 1

a single stack of thin layers, said stack comprising, successively from said face, a discontinuous silver-based or aluminum-based metal layer then, in contact with said discontinuous metal layer, a dielectric overlayer

Methodology Applied
Scientific EffectThin film interference: Interference

Implementation Method 2

reduced reflection tint, improving the glass article's appearance

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3935023B1Coloured laminated glass article
Publication Date: 2024.05.08 SAINT GOBAIN VITRAGE SA

AI summary

The subject matter of the invention is a coloured, transparent, laminated glass article comprising a first glass sheet adhesively bonded to a second glass sheet by means of a lamination interlayer, said first glass sheet being coated, on the surface thereof that is in contact with said lamination interlayer, with a single stack of thin layers, said stack comprising, successively from said surface, a silver-based or aluminium-based discontinuous metallic layer then, in contact with said discontinuous metallic layer, a dielectric overlayer.