Silver-Based Coated Substrate for Shiny Silver Appearance and Low Solar Factor

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Solution Overview

Problem

Current glazing materials fail to achieve a shiny silver appearance while maintaining low solar factor, sufficient light transmission, and high selectivity, which are essential for effective solar control and aesthetic appeal.

Innovation Solution

A transparent substrate coated with a stack of thin layers comprising three functional silver-based metal layers and four dielectric coatings, where the thickness of the layers is optimized, with the first dielectric coating placed between the substrate and the relatively thick first functional layer, to achieve a shiny silver appearance and high exterior reflection without compromising solar control performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If substrates are coated with chemically deposited (CVD) stacks or sputter-deposited stacks comprising non-silver-based functional layers (e.g., niobium-based) to achieve a shiny silver appearance in external reflection, then aesthetic appearance is improved, but solar control performance deteriorates (high solar factor, insufficient light transmission, low selectivity)

Engineering Contradiction:
Improveaesthetic appearance (shiny silver reflection)VSAvoidsolar factor
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The invention changes the material composition parameter by using silver-based functional layers instead of conventional CVD or non-silver sputter layers, and optimizes the thickness parameters of each layer to achieve both shiny silver appearance and low solar factor. The specific thickness ranges (e.g., first functional layer: 5-15 nm, second functional layer: 10-20 nm, third functional layer: 15-25 nm) are carefully controlled to balance optical and thermal performance.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite multi-layer structure combining silver-based functional layers with dielectric coatings, where each layer contributes specific properties. The silver layers provide high reflectivity and shiny appearance, while the dielectric coatings enhance solar control and selectivity, achieving synergistic performance that neither material could achieve alone.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If stacks comprising three silver-based functional metal layers and four dielectric coatings are used to minimize solar factor and increase exterior reflection, then solar control performance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvesolar factorVSAvoidstack structure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention applies local quality by assigning specific functions to specific layers within the stack. Each silver-based functional layer has optimized thickness and positioning to perform specific optical functions (reflection, transmission, absorption), while dielectric coatings are strategically placed to enhance particular properties. This localized optimization allows complex performance requirements to be met through modular layer design.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention segments the coating system into distinct functional layers (three silver-based metal layers and four dielectric coatings), where each segment performs a specific function. This segmentation allows independent optimization of each layer's properties and thickness, making the manufacturing process more controllable despite the overall complexity of the multi-layer structure.

Inventive Principle:
Principle #1Segmentation

3Object-affected harmful factors

If conventional stacks are used to achieve low solar factor, then solar protection is improved, but external reflection levels are too low and colors are non-neutral

Engineering Contradiction:
Improvesolar factorVSAvoidexternal reflection
Core Design Contradiction:
Object-affected harmful factorsVSIllumination intensity

Solution Approach 1:

The invention changes the material parameter from conventional non-silver layers to silver-based layers, which inherently provide higher reflectivity and neutraler colors. The thickness parameters of the silver layers are optimized to enhance external reflection while maintaining low solar factor, achieving both solar protection and aesthetic appearance simultaneously.

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

The solution provides a material with a light transmittance of less than 60% and exterior-side light reflection of greater than or equal to 20%, achieving a balance between optical, thermal performance, and aesthetic appearance, while maintaining excellent solar protection.

Implementation Method 1

substrates coated with a stack of thin layers comprising three metallic functional layers, each arranged between two dielectric coatings... to reduce the amount of solar energy entering buildings by having a low solar factor

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

to have low emissivity to reduce heat loss by long-wave infrared radiation

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

These stacks are generally obtained by a succession of deposits carried out by cathodic sputtering, possibly assisted by a magnetic field

Methodology Applied
Scientific EffectSputtering: Sputtering

Data Source

PatentEP3319917B1Substrate provided with a stack having thermal properties
Publication Date: 2024.11.13 SAINT GOBAIN VITRAGE SA
  • EP3319917B1 patent drawingFigure 1

AI summary

The invention relates to a material comprising a transparent substrate coated with a stack of thin layers which, starting at the substrate, successively comprises three functional, silver-based metallic layers and four dielectric coatings referred to as M1, M2, M3 and M4 moving outwards from the substrate, said layers and coatings being disposed alternately, characterized in that - the thickness of the first functional layer is less than the thickness of the second functional layer and less than the thickness of the third functional layer and, - the dielectric coatings M1 and M2 each have an optical depth Eo1 and Eo2 that satisfies the relation Eo2 < 1.1 Eo1.