Phase Difference Film Block Copolymer Refractive Index Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing phase difference films with refractive indices satisfying nx > nz > ny are costly and have low productivity, and those using multiple layers are complex and expensive.
Innovation Solution
A phase difference film comprising a resin with a block copolymer structure, specifically a triblock copolymer and a diblock copolymer, where the block copolymer has a negative intrinsic birefringence value, allowing for a single-layer film with controlled refractive indices and phase separation structure, enabling efficient production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a normal resin film is processed with normal methods such as stretching, then the film can be produced easily, but it cannot achieve the refractive index relationship nx > nz > ny required for phase difference films
Solution Approach 1:
The patent changes the fundamental parameter of the resin material by using a block copolymer with specific compositional ratios (polymerization unit A: 30-70 wt%, polymerization unit B: 30-70 wt%). This material parameter change enables the film to achieve nx > nz > ny refractive index relationship through phase separation, eliminating the need for complex contraction processing while maintaining ease of manufacture.
Solution Approach 2:
The patent employs a composite material approach by creating a block copolymer consisting of two different polymerization units (A and B) with distinct refractive index properties. The phase separation between these two units creates the desired anisotropic refractive index distribution, achieving the technical goal through material composition rather than mechanical processing.
2Manufacturing precision
If multiple resin films are combined to achieve desired optical characteristics, then the optical performance can be improved, but the product structure becomes complicated and production cost increases
Solution Approach 1:
The patent merges the functions of multiple resin films into a single film by incorporating both polymerization unit A and polymerization unit B within one block copolymer structure. The phase separation between these units naturally creates the multi-layer optical effect without requiring actual physical layering, thus achieving complex optical characteristics in a simple single-layer structure.
Solution Approach 2:
The patent applies local quality by creating regions with different refractive indices through phase separation of polymerization units A and B within the single film. This local differentiation of material properties achieves the optical functionality of multiple layers while maintaining a unified single-layer structure, reducing overall device complexity.
3Manufacturing precision
If film contraction processing is applied to achieve the refractive index relationship, then the desired optical characteristics can be obtained, but production cost increases and productivity decreases
Solution Approach 1:
The block copolymer film performs self-service by automatically achieving the desired refractive index relationship (nx > nz > ny) through its inherent phase separation mechanism during normal processing. The material self-organizes into the required optical structure without requiring additional contraction treatment steps, thereby eliminating process complexity and improving productivity.
Solution Approach 2:
The patent replaces the mechanical contraction processing system with a material-based solution. Instead of using mechanical forces to achieve the refractive index relationship, the invention uses the chemical and physical properties of the block copolymer's phase separation to naturally create the desired optical characteristics, simplifying the production process.
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 a phase difference film with desired optical characteristics at a low cost and high productivity, suitable for applications like viewing angle compensation in liquid crystal display devices, with improved processability and heat resistance.
Implementation Method 1
a resin C having a negative intrinsic birefringence value, wherein the resin C contains a block copolymer having a block (A) including as a main component a polymerization unit A having a negative intrinsic birefringence value
Implementation Method 2
in the orientation layer, the resin C exhibits a phase separation structure, and a distance between phases in the phase separation structure is 200 nm or less
Data Source
AI summary
A phase difference film including an orientation layer formed of a resin C having a negative intrinsic birefringence value, wherein the resin C contains a block copolymer having a block (A) including as a main component a polymerization unit A having a negative intrinsic birefringence value and a block (B) including as a main component a polymerization unit B, and a weight fraction of the block (A) therein being 50% by weight or more and 90% by weight or less, and the phase difference film has an NZ factor of greater than 0 and smaller than 1; and the production method thereof. Preferably, in the orientation layer, the resin C exhibits a phase separation structure, and a distance between phases in the phase separation structure is 200 nm or less.