Patent ID: 7001557
Filing Date: 2006-02-21
Classification: C08J,C08L,G11B,Y10S,Y10T

Abstract:
1. A process for producing a biaxially oriented polyester film, comprising the steps of: preparing a raw material blend of a polyester (A) mainly composed of ethylene terephthalate and a polyether imide (B) of 70/30–10/90 as (A/8) ratio by weight; melt-extruding polyester (A) with said raw material blend to mold a resin sheet with a single glass transition temperature; and stretching the resin sheet at a ratio of 3.0 to 10 times in the machine direction and at a ratio of 3.0 to 10 times in the transverse direction, wherein the biaxially oriented polyester film has a refractive index of 1.60 to 1.80 at least in either the machine direction or the transverse direction.