Patent ID: 7048994
Filing Date: 2006-05-23
Classification: B32B,G11B,Y10S,Y10T

Abstract:
1. A laminated polyester film comprising a polyester layer A and a polyester layer B laminated to one side of the polyester layer A, wherein the polyester layer B contains a cyclic trimer in an amount of not more than 0.8 percent by weight based on the weight of the polyester layer B, has a terminal carboxyl group concentration of not more than 35 eq/10 6 g in the polyester for forming the polyester layer B, and contains inactive particles B having an average particle diameter of 50 to 1000 nm in an amount of 0.001 to 1 percent by weight based on the weight of the polyester layer B and; wherein the polyester layer A does not contain inactive particles or contains inactive particles A having a smaller average particle diameter than the average particle diameter of the inactive particles B; wherein the surface roughness (WRaA) of the surface of the polyester layer A not in contact with the polyester layer B ranges from 0.1 to 4 nm; wherein the intrinsic viscosity of the polyester for forming the polyester layer B is not less than 0.55 dl/g, and not more than 1.0 dl/g; wherein the ten point-average roughness (WRzB) of the surface of the polyester layer B not in contact with the polyester layer A ranges from 30 to 300 nm; wherein the polyester layer A contains diethylene glycol in an amount of 0.1 to 2.5% by weight based on the weight of the polyester layer A; and wherein the crystallization parameter (ΔTcm) of the polyester for forming the polyester layer A ranges from 70 to 180° C.