Lead-Free Low Melting Glass Sealing Material for Multilayered Glass Panels

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The challenge is to achieve high thermal insulation and reliable hermetic sealing in multilayered glass panels while maintaining mechanical strength, as conventional low melting glasses with lower sealing temperatures compromise mechanical strength and thermal expansion matching with glass substrates.

Innovation Solution

A sealing material comprising lead-free low melting glass particles with vanadium oxide and tellurium oxide, low thermal expansion filler particles, and glass beads, where the volume fraction of glass beads is between 10% to 35% and the low melting glass fraction is higher than the filler fraction, ensuring mechanical strength and thermal expansion matching with the glass substrates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional lead-based or bismuth-based low melting glass is used for sealing, then sealing temperature can be maintained at high levels (400°C or higher), but mechanical strength of the seal deteriorates and thermal expansion matching with glass substrates becomes difficult

Engineering Contradiction:
Improvesealing temperatureVSAvoidmechanical strength of seal
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The patent changes the chemical composition parameters of the sealing glass by incorporating specific ratios of V2O5 (5-65 wt%), TeO2 (15-50 wt%), and Ag2O (10-60 wt%), which fundamentally alters the melting characteristics and mechanical properties of the sealing material, enabling low-temperature sealing with maintained strength

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite sealing glass system combining multiple oxides (vanadium phosphate glass base with tellurium and silver oxide additives) that synergistically improve both low-temperature meltability and mechanical strength, resolving the trade-off between sealing temperature and seal integrity

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If resin is used for spacers to achieve low thermal conductivity and low sealing temperature, then thermal insulation improves, but hermetic sealing becomes difficult due to resin's lower thermal resistance

Engineering Contradiction:
Improvethermal insulationVSAvoidhermetic sealing
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent introduces a specialized low-melting glass sealing material as an intermediary between the resin spacer and the glass substrates, which can bond to both the resin and glass at low temperatures while providing the necessary hermetic seal, thus mediating between the conflicting requirements of low thermal conductivity and reliable sealing

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stress or pressure

If the number of spacers is increased to secure space inside the panel for high vacuum, then vacuum insulation improves, but thermal insulation deteriorates due to metal spacers' high thermal conductivity

Engineering Contradiction:
Improvevacuum degreeVSAvoidthermal insulation
Core Design Contradiction:
Stress or pressureVSLoss of energy

Solution Approach 1:

The patent changes the thermal conductivity parameter of the spacer material by switching from metal to resin-based materials with low thermal conductivity, which fundamentally alters the thermal performance while maintaining the structural function of spacing and vacuum sealing

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 configuration enhances the mechanical strength and reliability of the seal, allowing for lower sealing temperatures, improved thermal insulation, and reduced manufacturing costs, making the multilayered glass panels suitable for widespread application in building materials.

Implementation Method 1

The Ag2O-V2O5-TeO2-based lead-free low melting glass has a softening point in the temperature range of 268°C to 320°C, and softens and fluidizes at a much lower temperature than a conventional lead-based or bismuth-based low melting glass

Methodology Applied
Scientific EffectSoftening and fluidization of glass: Melting

Implementation Method 2

a volume fraction of the glass beads in the solid content is not less than 10% to not more than 35%; and a volume fraction of the lead-free low melting glass particles in the solid content is larger than a volume fraction of the low thermal expansion filler in the solid content

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3718982B1Encapsulating material and multilayered glass panel using same
Publication Date: 2023.07.26 RESONAC CORP
  • EP3718982B1 patent drawingFigure 1A~1B
  • EP3718982B1 patent drawingFigure 2
  • EP3718982B1 patent drawingFigure 3A~3B

AI summary

The present invention provides a highly reliable multilayered glass panel and an encapsulating material for achieving the highly reliable multilayered glass panel. The encapsulating material includes lead-free low melting glass particles containing vanadium oxide and tellurium oxide, low thermal expansion filler particles, and glass beads as a solid content. A volume fraction of the glass beads in the solid content is not less than 10% to not more than 35%, and a volume fraction of the lead-free low melting glass particles in the solid content is larger than a volume fraction of the low thermal expansion filler in the solid content.