Abstract: A biaxially oriented laminated polyester film which has excellent dimensional stability to environmental changes such as temperature and humidity variations and excellent flatness and windability. A biaxially oriented laminated polyester film comprising a film layer B on one side of a film layer A and having a surface roughness (RaB) on the film layer B side which is 1.0 nm or more larger than the surface roughness (RaA) on the film layer A side, wherein at least one of the film layers comprises an aromatic polyester (I) composed of a glycol component and a dicarboxylic acid component containing 5 mol % or more and less than 80 mol % of a recurring unit represented by the following formula (A): wherein RA is an alkylene group having 1 to 10 carbon atoms.

Abstract: The polyester film roll, which is free from wrinkles and slacks generated with the passage of time and is having a good roll appearance, is provided without changing the characteristics of the film.

Abstract: A polyester resin having excellent dimensional stability against environmental changes and excellent dimensional stability in the processing step while having excellent moldability and a biaxially oriented polyester film comprising the same. The polyester resin comprises a recurring unit represented by the following formula (A) and a recurring unit represented by the following formula (B) as the main constituents: —O—C(O)—R1—C(O)—O—R2—O—??(A) —O—C(O)—R3—C(O)—O—R2—O—??(B) (R? is a phenylene group or naphthalenediyl group, R2 is an alkylene group having 2 to 4 carbon atoms or cyclohexylene group, and R3 is 6,6?-(alkylenedioxy)di-2-naphthoic acid), wherein the content of the recurring unit (B) is not less than 5 mol % and less than 50 mol %, and the ratio of adjacent recurring units (A) and (B) is less than 0.9 based on a value obtained by doubling the product of the content of the recurring unit (A) and the content of the recurring unit (B).

Abstract: A polyester resin having excellent dimensional stability against environmental changes and excellent dimensional stability in the processing step while having excellent moldability and a biaxially oriented polyester film comprising the same. The polyester resin comprises a recurring unit represented by the following formula (A) and a recurring unit represented by the following formula (B) as the main constituents: —O—C(O)—R1—C(O)—O—R2—O—??(A) —O—C(O)—R3—C(O)—O—R2—O—??(B) (R1 is a phenylene group or naphthalenediyl group, R2 is an alkylene group having 2 to 4 carbon atoms or cyclohexylene group, and R3 is 6,6?-(alkylenedioxy)di-2-naphthoic acid), wherein the content of the recurring unit (B) is not less than 5 mol % and less than 50 mol %, and the ratio of adjacent recurring units (A) and (B) is less than 0.9 based on a value obtained by doubling the product of the content of the recurring unit (A) and the content of the recurring unit (B).

Abstract: A biaxially oriented laminated polyester film which has dimensional stability against environmental changes such as temperature and humidity variations and rarely elongates when a load is applied thereto at a high temperature. The biaxially oriented laminated film comprises a film layer (A) made of an aromatic polyester (A) and a film layer (B) made of an aromatic polyester (B), wherein the content of a 6,6?-(alkylenedioxy)di-2-naphthoic acid component represented by the following formula (I) based on the total of all the acid components is less than 5 mol % in the aromatic polyester (A) and not less than 5 mol % and less than 80 mol % in the aromatic polyester (B); and the peak temperature of tan ? on a high temperature side is 135° C. or higher when viscoelasticity is measured in the machine direction. (in the formula (I), R is an alkylene group having 1 to 10 carbon atoms.

Abstract: It is an object of the present invention to provide a biaxially oriented laminated polyester film which has excellent dimensional stability to environmental changes such as temperature and humidity variations and excellent flatness and windability. The present invention is a biaxially oriented laminated polyester film comprising a film layer B on one side of a film layer A and having a surface roughness (RaB) on the film layer B side which is 1.0 nm or more larger than the surface roughness (RaA) on the film layer A side, wherein at least one of the film layers comprises an aromatic polyester (I) composed of a glycol component and a dicarboxylic acid component containing 5 mol % or more and less than 80 mol % of a recurring unit represented by the following formula (A): wherein RA is an alkylene group having 1 to 10 carbon atoms.

Abstract: An object of the invention is to provide a biaxially oriented polyester film for automobile driving motors, which has, in addition to high-temperature dimensional stability, high hydrolysis resistance required for an insulating film of an automobile driving motor, and also exhibits excellent delamination characteristics.

Abstract: A biaxially oriented film for reinforcing the electrolyte membrane of a polymer electrolyte fuel cell, wherein the film includes (i) a layer mainly composed of polyethylene naphthalene dicarboxylate and has (ii) a Young's modulus in at least one direction of not less than 9,000 MPa and (iii) a thickness of 15 to 150 ?m. The biaxially oriented film has a satisfactory reinforcing effect as a reinforcing member for a polymer electrolyte membrane at the operation temperature of a polymer electrolyte fuel cell though it is a thin film.

Abstract: An optical adhesive polyester film comprising (A) a polyester film layer containing an aromatic polyester and an ultraviolet absorber and (B) a coating formed on at least one surface of the polyester film (A). The coating (B) contains at least one polymer selected from the group consisting of a coating polyester having a glass transition point of 40 to 100° C. and an acryl polymer having a glass transition point of 20 to 80° C. in an amount of 50 to 95% by weight based on the coating. The optical adhesive polyester film is disposed on the front of a plasma display so as to block externally incoming ultraviolet light.

Abstract: The polyester film roll, which is free from wrinkles and slacks generated with the passage of time and is having a good roll appearance, is provided without changing the characteristics of the film.

Abstract: An optical adhesive polyester film comprising (A) a polyester film layer containing an aromatic polyester and an ultraviolet absorber and (B) a coating formed on at least one surface of the polyester film (A). The coating (B) contains at least one polymer selected from the group consisting of a coating polyester having a glass transition point of 40 to 100° C. and an acryl polymer having a glass transition point of 20 to 80° C. in an amount of 50 to 95% by weight based on the coating. The optical adhesive polyester film is disposed on the front of a plasma display so as to block externally incoming ultraviolet light.

Abstract: The polyester film roll, which is free from wrinkles and slacks generated with the passage of time and is having a good roll appearance, is provided without changing the characteristics of the film.

Abstract: A biaxially oriented laminate polyester film for magnetic recording medium, which is a laminate film comprising a base layer (A) formed of a polyester resin and a coating layer (B) which exists on one surface of the base layer (A) and contains a binder resin, added fine particles and a surfactant, wherein the base layer (A) is a biaxially oriented film which substantially contains no fine particles added or contains 0.001 to 0.1% by weight of added fine particles having an average particle diameter of 0.005 to 0.3 &mgr;m, the coating layer (B) has a surface having a central plane roughness (SRa) of 5 nm or less, the surface of the coating layer (B) has protrusions having a major diameter of 0.05 &mgr;m or more in a density of 80,000 pieces/mm2 or less and has extra-large protrusions having a major diameter of 10 &mgr;m or more in a density of 20 pieces/cm2 or less.

Abstract: A biaxially oriented polyester film for magnetic recording media which has (1) a Young's modulus in a machine direction of 5.0 GPa or less and a Young's modulus in a direction perpendicular to the machine direction of 8.0 GPa or more, (2) a surface roughness on one side of 0.3 to 1.5 nm when measured for a measurement area of 246.6×187.5 &mgr;m and 0.1 to 3.0 nm when measured for a measurement area of 2.5×1.9 mm and a surface roughness on the other side of 0.6 to 2.5 nm when measured for a measurement area of 246.6×187.5 &mgr;m and 0.1 to 5.0 nm when measured for a measurement area of 2.5×1.9 mm, and, (3) controlled heat shrinkage factors in the machine and transverse directions at 105° C. and 150° C.

Abstract: A laminate film has a coated film layer containing a binder resin and an organic filler. The laminate film satisfies the following expressions (1) and (2) when it is heated at 200° C. for 120 minutes: 0≦(Ra1−Ra2)/Ra1<0.4  (1) 0.1<Ra2<7  (2) wherein Ra1 is an average roughness of root mean square (nm) of an exposed surface of the coated film layer before the heat treatment, and Ra2 is an average roughness of root mean square (nm) of the exposed surface of the coated film layer after the heat treatment. The film has protrusions with two or more interference fringes on the surface at a density of 100 per 100 cm2 at the most. The present laminate film is useful as a base film for a magnetic recording medium.

Abstract: A laminate film has a coated film layer containing a binder resin and an organic filler. The laminate film satisfies the following expressions (1) and (2) when it is heated at 200° C.

Abstract: A composite polyester film comprising (1) a base film C of an aromatic polyester which does not contain or contains inert particles having an average particle diameter of 5 to 2,000 nm in an amount of 0.001 to 5.

Abstract: A composite polyester film comprising (1) a base film C of an aromatic polyester which does not contain or contains inert particles having an average particle diameter of 5 to 2,000 nm in an amount of 0.001 to 5.

Abstract: The present invention relates to a low electrostatic composite polyester film comprising a base film C, a coating layer A formed on one side of the base film C, and a coating layer B formed on the other side of the base film C, where (1) the coating layer A is formed of a water-soluble or water-dispersible resin coating inert particles and has a center line average roughness (Ra−A) of the surface of 0.1 to 2 nm; (2) the coating layer B includes 1 to 40 wt % of inert particles and a composition containing a water-soluble or water-dispersible resin, the resin-containing composition containing 5 to 85 wt % of a silicone-modified polyester resin or 1 to 30 wt % of silicone or wax based on the layer B; and (3) the base film C is formed of an aromatic polyester.

Abstract: A film roll in which the distance from the center line of the film roll to the edge of the film extending in a film winding direction is slightly changed in a film breadthwise direction.