Optical compensation films having positive birefringence for liquid crystal display

一种液晶显示器、正双折射的技术，应用在光学、光学元件、液晶材料等方向，能够解决昂贵等问题

Active Publication Date: 2010-06-30
AKRON POLYMER SYST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0010] Currently commercially available positive C-plate materials require expensive secondary synthesis processes such as photopolymerization to lock liquid crystal molecules into homeotropic alignment

Method used

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  • Optical compensation films having positive birefringence for liquid crystal display
  • Optical compensation films having positive birefringence for liquid crystal display
  • Optical compensation films having positive birefringence for liquid crystal display

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Effect test

Embodiment Embodiment 1

[0160] v f The value can be determined by many factors including, but not limited to, the evaporation rate of the solvent, ambient temperature, the solubility of the polymer in the solvent, and the polymer chemical structure, which affects relaxation. The rate of evaporation is preferably slow enough to ensure spherical collapse, but fast enough to ensure that the rate of relaxation is slower at more dilute concentrations. The rate of evaporation can be adjusted by adjusting the ambient temperature and pressure as known in the art. The rate of relaxation depends on the chemical structure of the polymer and the film casting temperature. Polymers with rigid segments can freeze readily at ambient temperature. Example Example 1: Birefringence measurement

[0161] A polymer sample is first dissolved in a suitable solvent, and the solution is cast onto a piece of clean glass measuring 1 by 1.5 inches. The thickness of the polymer film is controlled within the range of 15-20 μm...

Embodiment 2

[0162] 2-Vinylnaphthalene (2.00 g) was charged to a Schlenk tube. The tube was stoppered, evacuated by evacuation, and filled with argon. The tube was evacuated and then refilled with argon four more times. While under a positive pressure of argon, the tube was immersed in an oil bath maintained at 70°C for 24 hours. After cooling to room temperature, the solid plug material was dissolved in tetrahydrofuran (THF). This solution was added dropwise to 500 mL of rapidly stirring methanol to precipitate the polymer. Precipitated polymer was collected by filtration and dried by forcing air through the material over a filter plate. The polymer was then dissolved in fresh THF and reprecipitated by dropwise addition to rapidly stirring methanol. After collection by filtration and drying, the polymer formed was found to have a MW of 127000 g / mol and a Tg of 139°C. Films cast from cyclopentanone (Cp) showed a positive birefringence of 0.0040 at 633 nm. Example 3: Preparation of p...

Embodiment 3

[0163] 2-Vinylnaphthalene (2.01 g), azobisisobutyronitrile (AIBN, 1.5 mg) and benzene (0.98 g) were charged into a 50 mL round bottom flask containing a Teflon-coated magnetic stir bar. The stirred reaction mixture was degassed by bubbling dry argon through the stirred reaction mixture for 15 minutes. The vessel contents were then kept under a positive pressure of argon and immersed in an oil bath maintained at 60°C for 19 hours. After cooling the reaction mixture to room temperature, the vessel contents were diluted with 25 mL of benzene. The resulting solution was slowly poured into 500 mL of rapidly stirring methanol to precipitate the formed polymer. The precipitated polymer was collected by filtration and dried by forcing air through the material over a filter plate. The polymer was then dissolved in THF and added dropwise to rapidly stirring methanol for reprecipitation. After collection by filtration and drying, the polymer formed was found to have a MW of 251000 g / m...

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Abstract

A method for controlling positive birefringence in an optical compensation film (positive C- plate) having high positive birefringence throughout the wavelength range 400 nm < Lambda < 800 nm is provided. The method includes selecting polymers with optically anisotropic subunits (OASUs) that exhibit the buttressing effect, wherein the OASUs may be disks, mesogens or aromatic rings substituted with birefringence enhancing substituents. The method further includes processing the polymer by solution casting to yield a polymer film with high birefringence without the need for stretching, photopolymerization, or other processes. These optical compensation films may be used in LCDs, particularly IPS-LCDs.

Description

technical field [0001] The present invention relates to optically compensatory films having a positive birefringence greater than 0.002 in the wavelength range of 400nm<λ<800nm ​​for use in optical devices such as liquid crystal displays ("LCD") devices, optical switches and waveguides where desired Controlled light management. More specifically, the optical compensation film is used in an in-plane transferring LCD ("IPS-LCD"). Background technique [0002] LCDs are used as display screens in many common applications, including digital clocks, microwave ovens, laptop computers, calculators and other electronic devices. LCDs offer advantages over fluorescent display technologies such as cathode ray tubes (CRTs) because they are lighter, thinner, and require less voltage and power to operate. [0003] LCD screens have good picture quality and contrast when viewed directly, ie, at an angle perpendicular or normal to the plane of the screen. However, as the viewing angl...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G02F1/13363G02B5/30C08J5/18
CPCG02B5/3083C09K19/3842C09K19/348G02F1/133634C09K2019/0429G02B5/3016C08J5/18Y10T428/31855C09K2323/03C09K2323/00G02B5/30G02F1/13363
Inventor X·J·郑F·W·哈里斯T·C·格尔姆罗思J·A·景D·张T·扩B·M·金
Owner AKRON POLYMER SYST
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