Photo-aligning Polyimide Resin for 3D Retardation Films

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Solution Overview

Problem

Conventional photo-alignment techniques for forming patterned retardation materials in 3D displays face challenges with low adhesion to resin films, reduced alignment sensitivity, and high exposure requirements for UV light, which limits the efficiency and reliability of the retardation material production.

Innovation Solution

A cured-film formation composition comprising a compound with a photo-aligning group, a hydrophilic polymer, and a cross-linking agent, which enhances adhesion and photoreaction efficiency, allowing for sensitive alignment of polymerizable liquid crystals on resin films, even with reduced UV exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional photo-alignment techniques are used to form patterned retardation materials, then the alignment of liquid crystals can be achieved, but the adhesion to resin films is poor and high UV exposure is required

Engineering Contradiction:

Improveadhesion to resin filmsVSAvoidUV exposure amount

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent uses a composite material system consisting of a polyimide resin containing photo-aligning groups (cinnamoyl or chalcone groups) integrated into the polymer chain. This composite structure combines the adhesive properties of polyimide with the photo-alignment functionality of the photodimerizable groups, enabling effective liquid crystal alignment on resin films with reduced UV exposure requirements

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent modifies the chemical structure of the polyimide resin by incorporating photo-aligning groups with specific photoreactive moieties. This parameter change in the material composition enables the resin to achieve both good adhesion to resin films and high photoreaction efficiency, reducing the UV exposure amount needed for effective alignment

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If acrylic resins with photodimerized moieties are used for orientation material formation, then photo-alignment can be achieved, but the alignment sensitivity is insufficient

Engineering Contradiction:

Improvealignment sensitivityVSAvoidphoto-alignment efficiency

Core Design Contradiction:

Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent changes the chemical parameters of the resin by using polyimide resin with specific photo-aligning groups instead of conventional acrylic resins. This parameter change results in higher alignment sensitivity while maintaining ease of manufacture through standard photo-alignment processes

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces local photo-aligning groups (cinnamoyl or chalcone groups) at specific positions within the polyimide resin structure. These localized photoreactive moieties provide high alignment sensitivity without requiring changes to the overall manufacturing process

Inventive Principle:

Principle #3Local quality

3Productivity

If conventional orientation materials are used, then liquid crystal alignment can be formed, but the photoreaction efficiency is low requiring large exposure amounts

Engineering Contradiction:

Improveproduction efficiencyVSAvoidUV light exposure amount

Core Design Contradiction:

ProductivityVSUse of energy by stationary object

Solution Approach 1:

The patent modifies the photoreactive properties of the orientation material by incorporating polyimide resin with photo-aligning groups that have higher photoreaction efficiency. This parameter change reduces the UV exposure amount required while maintaining production efficiency

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional photo-aligning mechanisms with a polyimide-based system that utilizes photodimerization of cinnamoyl or chalcone groups. This substitution provides higher photoreaction efficiency and reduces the energy input required for the alignment process

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 composition provides a highly sensitive and reliable orientation material with improved solvent resistance and photoreaction efficiency, enabling efficient formation of patterned retardation materials on resin films, enhancing the production process for 3D displays.

Implementation Method 1

a compound having a photo-aligning group and one substituent selected from a hydroxy group, a carboxy group, and an amino group

Methodology Applied

Scientific EffectPhotodimerization reaction: Photopolymerisation

Implementation Method 2

a cross-linking agent that reacts with the compound (A) and the polymer (B) and reacts at a temperature lower than a sublimation temperature of the compound (A)

Methodology Applied

Scientific EffectCross-linking reaction: Chemical Bonding

Data Source

PatentUS9823400B2Cured film formation composition, orientation material, and retardation material

Publication Date: 2017.11.21 NISSAN CHEM CORP

AI summary

There is provided a cured-film formation composition that forms a cured film having excellent photoreaction efficiency and solvent resistance, and high adhesion, an orientation material for photo-alignment, and a retardation material formed with the orientation material.