Silver-Free Solar Control Coating for Automotive Glazing

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Solution Overview

Problem

Silver-based solar control coatings in automotive glazing face challenges such as sensitivity to process conditions, adhesion issues, short shelf life, delamination risks, and increased costs, which affect their performance and safety, particularly in large glazed areas like panoramic roofs.

Innovation Solution

A glazing system with a solar control coating comprising a first and second electrically conductive layer, separated by a first separation layer, which reduces total solar transmission and counteracts high interior reflectance through destructive optical interference, providing a silver-free, cost-effective, and mechanically robust solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If silver-based solar control coatings are used in automotive glazing, then solar radiation control is improved, but adhesion reliability and shelf life deteriorate

Engineering Contradiction:
Improvesolar radiation controlVSAvoidadhesion reliability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent removes silver from the solar control coating composition entirely, extracting the problematic element that causes adhesion issues and short shelf life. The coating uses alternative materials (such as nickel-chromium alloys or other non-silver metals) that maintain solar control functionality without the adhesion and stability problems associated with silver.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs composite coating structures combining multiple material layers (e.g., metal alloy layers, oxide layers, and intermediate layers) to achieve both solar control performance and adhesion reliability. These composite structures provide the necessary optical properties while ensuring proper adhesion to glass substrates and resistance to delamination.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If silver-based solar control coatings are used in automotive glazing, then solar radiation control is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvesolar radiation controlVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent eliminates silver from the coating formulation, which simplifies the manufacturing process by removing the need for specialized silver deposition techniques and quality control procedures. The alternative materials used can be deposited using more conventional and cost-effective processes.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent modifies the coating material composition parameters by substituting silver with alternative metals or alloys that have different deposition characteristics. This change in material parameters allows for simpler manufacturing processes, reduced quality control complexity, and lower overall production costs while maintaining the required solar control performance.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If silver-based solar control coatings are used in automotive glazing, then solar radiation control is improved, but delamination resistance deteriorates

Engineering Contradiction:
Improvesolar radiation controlVSAvoiddelamination resistance
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent removes silver from the coating system, eliminating the inherent delamination problems associated with silver-based coatings. The alternative materials selected do not exhibit the same delamination tendencies, thereby improving the long-term structural integrity of the glazing assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses multi-layer composite coating structures with carefully selected materials and intermediate layers that enhance adhesion and prevent delamination. These composite structures distribute stress more effectively and create stronger bonding interfaces with the glass substrate, significantly improving delamination resistance compared to single-layer silver coatings.

Inventive Principle:
Principle #40Composite materials

4Weight of moving object

If glazed area is increased to reduce vehicle weight, then fuel efficiency is improved, but solar load increases

Engineering Contradiction:
Improvevehicle weightVSAvoidsolar load
Core Design Contradiction:
Weight of moving objectVSLoss of energy

Solution Approach 1:

The patent applies thin-film solar control coatings on the interior surfaces of the glass layers. These thin films provide effective solar radiation control without adding significant weight, maintaining the weight reduction benefits of large glazed areas while mitigating the increased solar load through the coating's reflective and absorptive properties.

Inventive Principle:
Principle #30Flexible shells and thin films

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 achieves low total solar transmission and visible light transmission, enhancing thermal insulation and safety while reducing the risk of delamination and increasing the shelf life of the glazing, making it suitable for applications like roofs and side windows.

Implementation Method 1

reduces total solar transmission and counteracts high interior reflectance through destructive optical interference

Methodology Applied
Scientific EffectDestructive optical interference: Interference

Implementation Method 2

infrared (IR) reflective coatings that are designed to allow visible light to pass through while reflecting solar infrared radiation back into the environment

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

Thermal energy is transferred from the environment to the glass by means of convection and radiation

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 4

Thermal energy is transferred from the environment to the glass by means of convection and radiation

Methodology Applied
Scientific EffectRadiation: Radiation

Implementation Method 5

then through the glass by means of conduction

Methodology Applied
Scientific EffectConduction: Conduction (thermal)

Implementation Method 6

Low-E coatings drastically reduce the amount of thermal radiant heat energy emitted by a glass article

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP4484150A1Glazing with solar control capabilities
Publication Date: 2025.01.01 AGP WORLDWIDE OPERATIONS GMBH
  • EP4484150A1 patent drawingFigure 1~2
  • EP4484150A1 patent drawingFigure 3
  • EP4484150A1 patent drawingFigure 4

AI summary

The invention falls in the field of automotive glazing and relates to a glazing for a vehicle with a solar control coating. The invention also relates to a roof, backlite, rear quarter, sidelite or sidedoor comprising said glazing and to a vehicle comprising said glazing.