Cellulose acetate film for use in liquid crystal displays

Abstract

A liquid crystal device having a plurality of pixel electrodes for transmitting light, a first panel having an activation portion for selectively activating the plurality of pixel electrodes, an orientation layer formed on the activation portion, a light shielding pattern formed on the orientation layer, a second panel having a second orientation layer, a liquid crystal formed between the first and second panels, a polarizing plate or a color filter and a protective film on at least one of the aforementioned surfaces wherein the protective layer includes a cellulose ester selected from the group consisting of cellulose acetate, cellulose formate, cellulose propionate, cellulose butyrate, ethyl cellulose, methyl cellulose and benzyl cellulose having an inherent viscosity of from about 1.0 to less than 2.0 dl / g.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to a liquid crystal display and particularly to a polymeric protective layer on the liquid crystal display. More particularly, the present invention relates to a protective layer formed from a cellulose ester having an inherent viscosity.(IV) of about 1.0 dl / g to less than about 2.0 dl / g.2. Background of the InventionCellulose ester films and more particularly, a cellulose acetate film is used in various photographic or optical elements because it is tough and has flame retardant properties. Generally, cellulose acetate film has wide acceptance as a photographic support material. For example, U.S. Pat. Nos. 3,705,148 and 3,718,728 describe methods for improving the resistance to distortion and shrinkage of a cellulose acetate film when exposed to very high temperatures.Recently, cellulose acetate film has been used in the manufacture of liquid crystal displays or LCDs due to the film having an optical ...

AI Technical Summary

Benefits of technology

The present invention provides an improved LCD having a protective layer comprising a cellulose ester wherein the cellulose ester has a IV of from about 1.0 dl/g to less than about 2.0 dl

Problems solved by technology

The intrinsic viscosity and degree of polymerization requirement has a significant effect on the cost and quality of the cellulose acetate film.

The higher degree of polymerization also requires lower catalyst levels that may lead to lower quality as shown by more insoluble material.

However, the mechanical strength requirements for cellulose acetate used in a liquid crystal display are less than that for photographic film.