CELLULOSE ACYLATE FILM AND METHOD FOR PRODUCING THE SAME

摘要

A cellulose acylate film that contains at least one kind of cellulose acylate that has a substitution degree of an acyl group that contains an aromatic group of from 0.1 to 2.0, or a substitution degree of an acyl group having from 2 to 4 carbon atoms of from 2.0 to 2.6, and has an in-plane retardation at a wavelength of 550 nm Re(550) of from 80 to 350 nm, and the number of bright spots caused from irregular retardation regions having a major axis diameter of from 0.01 to 0.05 mm of 500 or less per 1 cm2 causes less light leakage irrespective of Re of 80 nm or more, so as to enhance the display capability of IPS type and FFS type liquid crystal display devices.

主权项

1. A cellulose acylate film,
comprising at least one kind of cellulose acylate that has a substitution degree of an acyl group that contains an aromatic group of from 0.1 to 2.0, or a substitution degree of an aliphatic acyl group having from 2 to 4 carbon atoms of from 2.0 to 2.6, having an in-plane retardation at a wavelength of 550 nm Re(550) of from 80 to 350 nm, and wherein when two polarizing plates are disposed to form crossed nicols and the cellulose acylate film is inserted between the two polarizing plates to observe bright spots caused from irregular retardation regions having a major axis diameter of from 0.01 to 0.05 mm with a polarizing microscope, the number of the observed bright spots is 500 or less per 1 cm2.