Acrylic Adhesive Sheet for Plasma Display Panels
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Pressure-sensitive adhesive sheets used in plasma display panels face challenges with stability at high temperatures, adhesion to glass, and reworkability due to low glass transition temperature and high initial peeling strength, which are not adequately addressed by existing solutions that often require complex processes or increase manufacturing costs.
Innovation Solution
A pressure-sensitive adhesive sheet is developed with a corona-treated base film and a pressure-sensitive adhesive layer containing an acrylic copolymer and a multifunctional isocyanate compound, which enhances adhesion to the base film and glass while maintaining high temperature stability and improving reworkability by incorporating a siloxane compound to manage peeling strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a carboxyl group-containing monomer is used to increase Tg and adhesive strength, then high temperature stability and adhesive strength to glass are improved, but close adhesion to base film deteriorates and paste marks occur during reworking
Solution Approach 1:
The patent changes the chemical composition parameters by using a copolymer comprising both carboxyl group-containing monomer (for high Tg) and hydroxy group-containing monomer (for good adhesion). This parameter adjustment allows simultaneous achievement of high temperature stability and close adhesion without paste marks.
Solution Approach 2:
The patent employs a composite adhesive material system combining multiple functional monomers: carboxyl group-containing monomer provides thermal stability, hydroxy group-containing monomer provides adhesion, and isocyanate group-containing monomer provides crosslinking. This composite approach resolves the contradiction between thermal stability and adhesion.
2Strength
If a carboxyl group-containing monomer is used to increase adhesive strength, then adhesive strength to glass is improved, but reworkability is degraded due to high build-up of peeling strength
Solution Approach 1:
The patent adjusts the compositional parameters by incorporating hydroxy group-containing monomer which moderates the peeling strength buildup. This parameter change allows the adhesive to maintain strong bonding to glass while preventing excessive peeling strength accumulation that would harm reworkability.
Solution Approach 2:
The patent uses a composite monomer system where hydroxy group-containing monomer acts as a balancing component that prevents excessive crosslinking density. This composite material approach enables strong initial adhesion while maintaining acceptable reworkability by controlling the rate of peeling strength buildup.
3Ease of operation
If isocyanate group-containing acrylic copolymer is used to improve adhesion, then close adhesion to base film is improved, but the process becomes cumbersome requiring mixing of two separate components
Solution Approach 1:
The patent merges multiple functional monomers (carboxyl group-containing, hydroxy group-containing, and isocyanate group-containing monomers) into a single acrylic copolymer component. This consolidation eliminates the need to mix separate components, simplifying the application process while maintaining excellent close adhesion to the base film.
Solution Approach 2:
The single acrylic copolymer component performs multiple functions simultaneously: carboxyl groups provide thermal stability, hydroxy groups provide adhesion to base film, and isocyanate groups provide crosslinking. This multi-functional design eliminates process complexity while achieving superior adhesion performance.
4Strength
If isocyanate group reacts with glass to increase adhesive strength, then adhesive strength to glass is improved, but excessive increase causes reworkability degradation
Solution Approach 1:
The patent changes the chemical reaction parameters by controlling the amount and reactivity of isocyanate groups in the copolymer. This parameter adjustment ensures sufficient reaction with glass for strong adhesion while preventing excessive reaction that would cause harmful buildup of peeling strength and degrade reworkability.
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 excellent adhesion to both the base film and glass, maintains stability at high temperatures, and enhances reworkability, effectively addressing the limitations of existing technologies by using corona treatment and specific chemical compounds in the adhesive layer.
Implementation Method 1
a base film having a corona-treated layer on one side or both sides thereof
Implementation Method 2
the pressure-sensitive adhesive layer includes an acrylic copolymer and a multifunctional isocyanate compound
Implementation Method 3
incorporating a siloxane compound to manage peeling strength
Data Source
AI summary
The present invention relates to an adhesive sheet, a manufacturing method thereof, an optical filter and a plasma display panel. The present invention provides an adhesive sheet having an excellent base adhesion property through a hydroxyl group applied to a base film and an isocyanate-based compound contained in an adhesive layer through a corona processing. Accordingly, the present invention provides an adhesive sheet having an excellent base adhesion property and improved high temperature stability by using a carboxyl group-containing acryl-based copolymer having a high glass transition temperature. Further, the adhesive sheet of the present invention contains a siloxane-based compound if needed, thus preventing an initial peeling force from being increased. Accordingly, the present invention provides an adhesive sheet with an excellent base adhesion property, high temperature stability, adhesive property and reworkability to glass, and provides a manufacturing method thereof, an optical filter containing the same and a plasma display panel.