Acrylic Adhesive Resin Layer Preventing Air Bubbles
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Solution Overview
Problem
Adhesive resin compositions used in pressure-sensitive adhesive tapes and films often suffer from air bubble formation when thermally deformed after adhering to substrates, which reduces adhesion strength and can affect optical properties, especially in transparent or translucent applications.
Innovation Solution
A monolayered adhesive resin layer comprising an acrylic-based polymer, an acrylic-based monomer with reactivity, and a thermopolymerization initiator, specifically containing hydroxy-containing (meth)acrylates, which provides pressure-sensitive adhesiveness and prevents air bubble generation during thermal deformation by incorporating a peroxide initiator and optimizing the monomer-to-polymer ratio, along with thermal curing between dies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a pressure sensitive adhesive agent is used to laminate substrates, then adhesion strength is improved, but air bubbles are generated when thermally deformed, reducing adhesion strength and optical properties
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive resin by incorporating specific components: a polymer with carboxyl groups (5-50 wt%), a monomer with hydroxyl groups (40-80 wt%), and a crosslinking agent (0.1-10 wt%). This composition modification enables the adhesive to maintain strength while preventing air bubble formation during thermal deformation.
Solution Approach 2:
The patent creates a composite adhesive system combining multiple functional components: carboxyl-containing polymer, hydroxyl-containing monomer, and crosslinking agent. This composite structure provides both strong adhesion and resistance to air bubble formation during thermal processing, resolving the contradiction between adhesion strength and bubble prevention.
2Adaptability or versatility
If the adhesive resin layer is thermally deformed after adhering to substrate, then followability to substrate deformation is improved, but air bubbles are generated reducing optical properties
Solution Approach 1:
The patent modifies the thermal and rheological parameters of the adhesive by using a monomer with hydroxyl groups that has low viscosity and high reactivity. This allows the adhesive to flow and follow substrate deformation at elevated temperatures while the crosslinking mechanism prevents air bubble entrapment, maintaining optical clarity.
Solution Approach 2:
The patent applies the adhesive in a uncured state with optimal viscosity to ensure complete wetting and followability to substrate contours before thermal deformation. The subsequent crosslinking process then locks this bubble-free configuration, preserving optical properties while achieving the desired deformed shape.
3Strength
If crosslinking density is increased to improve adhesion strength, then adhesion strength is improved, but the adhesive becomes less flexible and more prone to air bubble formation
Solution Approach 1:
The patent optimizes the crosslinking density by controlling the amount of crosslinking agent (0.1-10 wt%) and the ratio of polymer to monomer. This creates a balanced network structure that provides sufficient adhesion strength while maintaining the flexibility needed to prevent air bubble formation during thermal deformation.
Solution Approach 2:
The patent uses a composite system where the crosslinking agent creates a three-dimensional network within the polymer-monomer matrix. This composite structure provides both the strength from crosslinking and the flexibility from the remaining uncrosslinked segments, preventing air bubble formation while maintaining adhesion.
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 effectively prevents air bubble formation and maintains adhesion strength even after thermal deformation, ensuring high followability and optical clarity in laminated substrates by using a thermally cured adhesive resin layer with enhanced substrate adhesion and deformation capabilities.
Implementation Method 1
a thermopolymerization initiator, wherein said (B) acrylic-based monomer is at least one of (meth)acrylate containing a hydroxy group
Implementation Method 2
(A) a cross-linked acrylic-based polymer
Implementation Method 3
said adhesive resin layer has pressure sensitive adhesiveness on both surfaces at an ambient temperature
Implementation Method 4
an acrylic-based monomer as a flowable resin component having reactivity, and (C) a thermopolymerization initiator, wherein said (B) acrylic-based monomer is at least one of (meth)acrylate containing a hydroxy group
Implementation Method 5
in differential scanning calorimetry (DSC) at a temperature raising rate of 10°C/min, heat generation is observed at 80°C or higher, and at least one peak is confirmed between 120°C and 210°C
Implementation Method 6
in differential scanning calorimetry (DSC) at a temperature raising rate of 10°C/min
Data Source
Figure 1~3
Figure 4
AI summary
The present invention provides an adhesive resin layer and an adhesive resin film which can prevent generation of air bubbles even when they are thermally deformed after adhering to a substrate, and have good followability to deformation of a substrate of a laminate in which a substrate, an adhesive resin layer, and a substrate are laminated in an order. More particularly, the present invention is a monolayered adhesive resin layer 11 comprising an acrylic-based adhesive resin composition, wherein the adhesive resin composition contains at least (A) an acrylic-based polymer, (B) an acrylic-based monomer or an acrylic-based oligomer, and (C) a thermopolymerization initiator, the adhesive resin layer 11 has pressure sensitive adhesiveness on both surfaces 11a, 11b at an ambient temperature, and in differential scanning calorimetry (DSC) at a temperature raising rate of 10°C/min, heat generation is observed at 80°C or higher, and at least one peak is confirmed between 120°C and 210°C.