Cellulose ester film, its manufacturing method, optical retardation film, optical compensation sheet, elliptic polarizing plate, and image display

A polarizing plate comprising:

• a polarizing film;
• and
• an optical compensation sheet being provided on a side of the polarizing film,
• wherein the optical compensation sheet comprises a cellulose ester film containing a polymer prepared by polymerizing an ethylenically unsaturated monomer having a weight average molecular weight of from 500 to 10,000, an acrylic polymer, or an acrylic polymer having on the side chain an aromatic ring or a cyclohexyl ring, and
• wherein R0 of the cellulose ester film is from 30 nm to 150 nm, Rt of the cellulose ester film is from 30 nm to 500 nm, and the ratio Rt/R0is in the range of from 0.8 to 3.5, wherein R0 represents a retardation in the plane of the cellulose ester film and Rt represents a retardation in the thickness direction, R0 and Rt being measured at 23° C. and 55% RH employing light having a wavelength of 590 nm.

A liquid crystal display comprising:

• a liquid crystal cell;
• and
• a polarizing plate provided on at least one side of the liquid crystal cell,
• wherein the polarizing plate comprising:
• a polarizing film;
• and
• an optical compensation sheet being provided on a side of the polarizing film,
• wherein the optical compensation sheet comprises a cellulose ester film containing a polymer prepared by polymerizing an ethylenically unsaturated monomer having a weight average molecular weight of from 500 to 10,000, an acrylic polymer, or an acrylic polymer having on the side chain an aromatic ring or a cyclohexyl ring, and
• wherein R0 of the cellulose ester film is from 30 nm to 150 nm, Rt of the cellulose ester film is from 30 nm to 500 nm, and the ratio Rt/R0 is in the range of from 0.8 to 3.5, wherein R0 represents a retardation in the plane of the cellulose ester film and Rt represents a retardation in the thickness direction, R0 and Rt being measured at 23° C. and 55% RH employing light having a wavelength of 590 nm.