Patent ID: 9470928
Filing Date: 2016-10-18
CPC Classification: C09K,G02F

Claim Text:
1. A method for preparing a homeotropic alignment liquid crystal film without an alignment layer, comprising a step of hydrophilically treating a cellulose derivative film having an acetate group by dipping into an aqueous NaOH solution to hydrolyze the acetate group to an alcohol group, and a step of directly coating a polymerizable and reactive liquid crystalline mixture solution consisting of a surfactant including a hydrophobic chain, reactive liquid crystal monomers, photoinitiators and solvents on the cellulose derivative film as a plastic substrate, so that the hydrophobic chain orients in a direction normal to the plastic substrate to cause the liquid crystal monomers to orient in a homeotropic direction, and drying and then UV irradiating the mixture solution to fix the homeotropic alignment liquid crystal film with a phase difference value in the vertical direction (Rth) of 99 to 113 nm and a thickness of 0.1 to 10 μm, wherein the surfactant is used in an amount of 0.4 to 2.0% by weight, based on the total mass of the solid included in the total solution, wherein the surfactant is selected from the group consisting of fluorocarbon-based and silicon-based surfactant, and wherein the reactive liquid crystal monomers comprise three compounds having the following Formulas 1 to 3 respectively, wherein the reactive liquid crystal monomers are prepared from solids dissolved in the solvents, the solids composed of 40% by weight of the compound of Formula 1, 27% by weight of the compound of Formula 2, 27% by weight of the compound of Formula 3, and 6.0% by weight of the photoinitiator.