Double-Sided Polarizer Asymmetric Adhesive Thickness Single Irradiation

Solution Overview

Problem

Double-sided polarizers with adhesive layers on both sides require complex manufacturing processes due to the need for separate light irradiation of each layer, leading to uneven curing and reduced adhesive force on non-irradiated surfaces, which affects durability and optical properties.

Innovation Solution

A double-sided polarizer design featuring active energy line-curable adhesive layers on both surfaces, with the first adhesive layer being 0.1 μm to 3 μm thick, allowing simultaneous curing by a single irradiation process, and using a cationic adhesive composition including epoxy and oxetane compounds for enhanced adhesive properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate light irradiation is performed for each adhesive layer, then complete curing of both layers is achieved, but the manufacturing process becomes complex and time-consuming

Engineering Contradiction:

Improveadhesive forceVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines two separate light irradiation operations into a single irradiation process by designing the adhesive layers with different thicknesses. The first adhesive layer is made thinner (0.1-3 μm) than the second adhesive layer, allowing both layers to be cured simultaneously when light is irradiated from one side, thus merging two process steps into one while ensuring complete curing of both layers

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent applies local quality by creating asymmetric thickness distribution in the adhesive layers. The first adhesive layer has a specific thin thickness (0.1-3 μm) optimized for light penetration and curing, while the second adhesive layer has a different thickness, allowing each layer to have optimal properties for its specific position and function in the overall structure

Inventive Principle:

Principle #3Local quality

2Reliability

If adhesive layer thickness is increased to ensure complete curing, then curing is achieved, but curling occurs in TD and MD directions

Engineering Contradiction:

Improvecuring completenessVSAvoidcurling deformation

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The patent applies local quality by creating asymmetric thickness distribution in the adhesive layers. The first adhesive layer has a specific thin thickness (0.1-3 μm) optimized for light penetration and curing, while the second adhesive layer has a different thickness, allowing each layer to have optimal properties for its specific position and function in the overall structure

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the thickness parameter of the adhesive layers to resolve the contradiction. By setting the first adhesive layer thickness to 0.1-3 μm and the second adhesive layer to a different thickness, the patent achieves complete curing of both layers through single-sided irradiation while preventing curling deformation that would occur with uniformly thick adhesive layers

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If uniform adhesive layer thickness is used on both sides, then manufacturing is simplified, but adhesive force becomes uneven after single-sided irradiation

Engineering Contradiction:

Improveadhesive layer applicationVSAvoidadhesive force uniformity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by creating asymmetric thickness distribution in the adhesive layers. The first adhesive layer has a specific thin thickness (0.1-3 μm) optimized for light penetration and curing, while the second adhesive layer has a different thickness, allowing each layer to have optimal properties for its specific position and function in the overall structure

Inventive Principle:

Principle #3Local quality

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 simplifies the manufacturing process, achieves superior adhesive force, durability, and optical properties, even in harsh environments, while maintaining water resistance and heat resistance.

Implementation Method 1

the first adhesive layer and the second adhesive layer are formed of an active energy line-curable adhesive

Methodology Applied

Scientific EffectPhoto-polymerization: Photopolymerisation

Data Source

PatentUS8968862B2Polarizer having protection films in two sides and optical device comprising the same

Publication Date: 2015.03.03 SHANJIN OPTOELECTRONICS (NANJING) CO

AI summary

A double-sided polarizer includes a polarizing film, a first adhesive layer formed on one surface of the polarizing film, a second adhesive layer formed on the other surface of the polarizing film, a first transparent film formed on the first adhesive layer, and a second transparent film formed on the second adhesive layer, wherein the first adhesive layer and the second adhesive layer are formed of an active energy line-curable adhesive and the first adhesive layer is 0.1 μm to 3 μm thick, and there is also provided an optical device including the double-sided polarizer.