Abstract: A laminated film for a reflecting plate is provided that comprises a layer A and a layer B, the layer A comprising a polyester that comprises substantially no antimony element and preferably comprises 1 to 25 wt % of inert particles having an average particle diameter of 0.3 to 3.0 ?m and the layer B being in contact with the layer A and comprising a polyester which preferably comprises 31 to 80 wt % of inert particles having an average particle diameter of 0.3 to 3.0 ?m. This laminated film has a practically satisfactory capability of reflecting visible light, can be produced stably even if inert particles are added in high concentration, hardly has streak-like defects, and can be suitably used as a substrate for a reflecting plate for a liquid crystal display or an internally illuminating electrical billboard.

Abstract: A laminated film for a reflecting plate is provided that comprises a layer A and a layer B, the layer A comprising a polyester that comprises substantially no antimony element and preferably comprises 1 to 25 wt % of inert particles having an average particle diameter of 0.3 to 3.0 ?m and the layer B being in contact with the layer A and comprising a polyester which preferably comprises 31 to 80 wt % of inert particles having an average particle diameter of 0.3 to 3.0 ?m. This laminated film has a practically satisfactory capability of reflecting visible light, can be produced stably even if inert particles are added in high concentration, hardly has streak-like defects, and can be suitably used as a substrate for a reflecting plate for a liquid crystal display or an internally illuminating electrical billboard.

Abstract: A white laminated film which has practically sufficient reflectivity at a visible range, can be formed stably, is free from deterioration (yellowing) by ultraviolet radiation, rarely deforms by heat and can be advantageously used as a reflector substrate for liquid crystal displays and internal illumination type electrically spectacular signs, is provided. The laminated film includes a first layer of a composition which includes 31 to 60 wt % of inert particles having an average particle diameter of 0.3 to 3.0 ?m and 40 to 69 wt % of a polyester consisting of 1 to 100 mol % of naphthalenedicarboxylic acid and 0 to 99 mol % of terephthalic acid as a dicarboxylic acid component and ethylene glycol as a diol component, and a layer B of a composition which includes 0 to 30 wt % of inert particles having an average particle diameter of 0.3 to 3.

Abstract: There is provided a white polyester film which retains practically satisfactory reflectivity with respect to the visible light range, can undergo stable film production even when inorganic fine particles are added in high concentration and is stable against a dimensional change caused by heat generated from a light source. The polyester film is a polyester film which comprises a composition comprising a copolyester and 30 to 50 wt % of inorganic fine particles based on the composition, shows a thermal shrinkage at 85° C. in longitudinal and transverse directions of not higher than 0.7% and a thermal shrinkage at 150° C. in the longitudinal and transverse directions of not higher than 5.0%, and shows an average reflectance at a wavelength of 400 to 700 nm of not lower than 90%.

Abstract: There is provided a white polyester film which retains practically satisfactory reflectivity with respect to the visible light range, can undergo stable film production even when inorganic fine particles are added in high concentration and is stable against a dimensional change caused by heat generated from a light source. The polyester film is a polyester film which comprises a composition comprising a copolyester and 30 to 50 wt % of inorganic fine particles based on the composition, shows a thermal shrinkage at 85° C. in longitudinal and transverse directions of not higher than 0.7% and a thermal shrinkage at 150° C. in the longitudinal and transverse directions of not higher than 5.0%, and shows an average reflectance at a wavelength of 400 to 700 nm of not lower than 90%.

Abstract: A polyester film which is excellent in uniform light diffusibility, heat-resistant dimensional stability and luminance and suitable as a substrate of a light-diffusing plate of a liquid crystal display device. The film comprises a polyester containing polyethylene-2,6-naphthalene dicarboxylate as a main component and has a heat shrinkage in two directions perpendicular to each other in the surface of the film of not higher than 0.3% when heat-treated at 105° C. for 30 minutes, a dimensional change rate in two directions perpendicular to each other in the surface of the film under a stress of 0.37 MPa within a temperature range of 30 to 150° C. of not higher than 1.0%, a density of not lower than 1.350 g/cm3, a total light transmittance of not lower than 87%, a haze value of lower than 1.5% and a thickness of 50 to 150 ?m.

Abstract: A film which is a biaxially oriented film comprising polyethylene-2,6-naphthalenedicaboxylate as a principal component, having a thermal strain ratio RMD (150) in the machine direction of the film at a temperature of 150° C. is ?1.5%?RMD (150)?0.0% when the thermal strain ratio RMD (T) in the machine direction of the film at a temperature T° C. based on the length LMD (t) in the machine direction (MD) of the film at a temperature t° C. is defined by RMD(T)={[LMD(T)?LMD(35)]/LMD(35)}×100(%), excellent in insulation characteristics without lowering processing characteristics, especially the characteristics during hot-pressing and suitable as a dielectric for capacitors.

Abstract: A biaxially oriented polyester film which has excellent productivity while ensuring a transferred image having excellent shape reproducibility and gradation and is particularly suitable for use as a base film for a heat-sensitive transfer ribbon. This film is formed by simultaneous biaxial orientation and contains 0.1 to 2 wt % of inert inorganic particles having an average particle diameter of 0.5 to 5 &mgr;m. This biaxially oriented polyester film has a value of 0.028 or less obtained by dividing the heat shrinkage factor (HS) (%) in a longitudinal direction at 200° C. by the F-5 value (N/mm2) (F5) in the longitudinal direction measured at normal temperature (about 23° C.) of the film.

Abstract: A biaxially oriented polyester film which has excellent productivity while ensuring a transferred image having excellent shape reproducibility and gradation and is particularly suitable for use as a base film for a heat-sensitive transfer ribbon. This film is formed by simultaneous biaxial orientation and contains 0.1 to 2 wt % of inert inorganic particles having an average particle diameter of 0.5 to 5 &mgr;m. This biaxially oriented polyester film has a value of 0.028 or less obtained by dividing the heat shrinkage factor (HS) (%) in a longitudinal direction at 200° C. by the F-5 value (N/mm2) (F5) in the longitudinal direction measured at normal temperature (about 23° C.) of the film.

Abstract: A film which is a biaxially oriented film comprising polyethylene-2,6-naphthalenedicaboxylate as a principal component, having a thermal strain; ratio RMD (150) in the machine direction of the film at a temperature of 150° C. is −1.5%≦RMD (150)≦0.0% when the thermal strain ratio RMD (T) in the machine direction of the film at a temperature T° C. based on the length LMD (t) in the machine direction (MD) of the film at a temperature t ° C.

Abstract: A polyester film which is excellent in uniform light diffusibility, heat-resistant dimensional stability and luminance and suitable as a substrate of a light-diffusing plate of a liquid crystal display device. The film comprises a polyester containing polyethylene-2,6-naphthalene dicarboxylate as a main component and has a heat shrinkage in two directions perpendicular to each other in the surface of the film of not higher than 0.3% when heat-treated at 105° C. for 30 minutes, a dimensional change rate in two directions perpendicular to each other in the surface of the film under a stress of 0.37 MPa within a temperature range of 30 to 150° C. of not higher than 1.0%, a density of not lower than 1.350 g/cm3, a total light transmittance of not lower than 87%, a haze value of lower than 1.5% and a thickness of 50 to 150 &mgr;m.

Abstract: A composite film for a film condenser, which comprises a biaxially oriented film made of polyethylene-2,6-naphthalenedicarboxylate as a main polymer component and an electrically conductive metal thin layer formed on the surface of the biaxially oriented film, wherein the number of flyspecks having an average diameter of 60 &mgr;m or greater in the surface of said biaxially oriented film is 20/m2 or less and the number of portions failing to satisfy a dielectric breakdown voltage of 200 V/&mgr;m (electrical insulation defects) in said composite film is 20/m2 or less, and a biaxially oriented film therefor. According to the present invention, there is provided a high-quality composite film for a film condenser, which has excellent physical properties and electric characteristics. Further, there is provided a very thin biaxially oriented film excellent in processability and surface properties and usable for the composite film.