Polymer film, and optically-compensatory film, polarizer and liquid-crystal display device comprising the same

摘要

A polymer film that has an in-plane retardation Re(λ) and a thickness-direction retardation Rth(λ) satisfying formula (i) and (ii), and that further has a surface energy of at least one surface is from 50 mN/m to 80 mN/m:
0≦Re(630)≦10, and |Rth(630)|≦25; and  (i)|Re(400)−Re(700)|≦10, and |Rth(400)−Rth(700)|≦35.  (ii)in the formulae, Re(λ) and Rth(λ) are measurement values at the wavelength of λ nm, and an optically-compensatory film, an optical material such as a polarizer and a liquid-crystal display device using the polymer film.

主权项

1. An IPS liquid-crystal display device comprising a polymer film that has an in-plane retardation Re(λ) and a thickness-direction retardation Rth(λ) (where λ indicates a wavelength (nm)) satisfying formulae (i) and (ii), and that further has a surface energy of at least one surface is from 50 mN/m to 80 mN/m:
0≦Re(630)≦1.7 nm, and |Rth(630)|≦15.0; and  (i) |Re(400)−Re(700)|≦2 nm, and |Rth(400)−Rth(700)|≦20 nm,  (ii) wherein a polymer material to form the film comprises a cellulose acylate, wherein the polymer film comprises at least one compound capable of lowering an optical anisotropy, an amount of the at least one compound capable of lowering an optical anisotropy being from 0.01 to 20% by mass of the cellulose acylate, and wherein a liquid-crystal material in a liquid-crystal cell is aligned in parallel in black display, liquid-crystal molecules are aligned in parallel to a surface of a substrate when no voltage is applied to the device for black display, and a transmission axis of an upper polarizer is parallel to a major axis direction of the liquid-crystal molecules in the liquid-crystal cell.