Abstract: An object of the invention is to provide a laminated film which hardly gives transmission loss based on reflection or scattering, is excellent in heat resistance and humidity resistance, and has an arbitrarily-controlled refractive index distribution. Accordingly, the invention is a laminated film comprising 5 or more laminated resin layers; the thickness of each of the resin layers being from 1 to 100 nm; and the film having a layer structure wherein the thicknesses of resin layers having the same composition A, out of the resin layers, increase or decrease from the side of a surface of the laminated film toward the side of the other surface opposite thereto.

Abstract: An objective of the present invention is to provide a film that has a high rigidity and is superior in dimension stability under high temperatures and transparency after heating processes, as well as in moldability within a wide temperature range, which has not been achieved by conventional techniques, and this objective has been achieved by a laminated film that includes 50 or more layers each of which is made of a thermoplastic resin and has a thickness of less than 30 nm or a biaxial oriented polyester film that has a density in a range from 1 to 1.4 g/cm3, a heat shrinkage of ?2 to 2% in the longitudinal direction at 180° C. and a breaking elongation in a range of 100 to 1000% in at least one direction.

Abstract: In order to provide a film having excellent heat resistance, thermal dimensional stability, and mechanical properties, in particular, a film capable of satisfying required properties, e.g., higher strength in accordance with the reduction in thickness of a base film, improved thermal dimensional stability and mechanical properties in a use environment, and higher heat resistance and improved thermal dimensional stability in accordance with the needs for miniaturization and more functionality in electrical and electronic areas, a thermoplastic resin is allowed to contain transition metal oxide particles, and is formed into a biaxially oriented thermoplastic resin film, wherein the melting point of the film is allowed to become higher than the melting point of the thermoplastic resin to be used.

Abstract: An object of the invention is to provide a laminated film which hardly gives transmission loss based on reflection or scattering, is excellent in heat resistance and humidity resistance, and has an arbitrarily-controlled refractive index distribution. Accordingly, the invention is a laminated film comprising 5 or more laminated resin layers; the thickness of each of the resin layers being from 1 to 100 nm; and the film having a layer structure wherein the thicknesses of resin layers having the same composition A, out of the resin layers, increase or decrease from the side of a surface of the laminated film toward the side of the other surface opposite thereto.

Abstract: The object of the present invention is to provide a method for producing a polyester film excellent in rigidity, toughness, dimensional stability, electric properties, etc. and less in thickness fluctuation and surface defects, hence very suitable as a film for various industrial materials such as magnetic recording media, capacitors, heat transfer ribbons and thermal mimeographic stencil paper. The first method of the present invention is a method for producing a polyester film, in which a film made of a resin mainly composed of a polyester is simultaneously biaxially stretched by a simultaneously biaxially stretching tenter oven, comprising the step of effecting small-ratio stretching at an area stretching ratio of 1.0005 to 3.

Abstract: An objective of the present invention is to provide a film that has a high rigidity and is superior in dimension stability under high temperatures and transparency after heating processes, as well as in moldability within a wide temperature range, which has not been achieved by conventional techniques, and this objective has been achieved by a laminated film that includes 50 or more layers each of which is made of a thermoplastic resin and has a thickness of less than 30 nm or a biaxial oriented polyester film that has a density in a range from 1 to 1.4 g/cm3, a heat shrinkage of ?2 to 2% in the longitudinal direction at 180° C. and a breaking elongation in a range of 100 to 1000% in at least one direction.

Abstract: The present invention provides a polyester film particularly useful as a base film for a magnetic recording medium such as cassette-type magnetic tape of a digital recording mode and a production process thereof. The polyester film is produced by irradiating UV light onto a surface of a film in a non-stretched stage or a stage prior to the completion of stretching to form fine protrusions on the surface. The fine protrusions on the film surface are specified by the ratio of 10-point average roughness Rz to center line average roughness Ra (Rz/Ra) on the surface (less than 20), the difference in concentration of carboxyl groups between the surface layer part and the inside of the film, and the number of fine protrusions.

Abstract: An object of the present invention is to provide a high-quality biaxially oriented film exhibiting an excellent electromagnetic conversion property, traveling durability, magnetic head traveling performance, etc. as a magnetic recording medium. The object of the present invention is achieved by a biaxially oriented film including a polymer alloy composed of polyester (polymer 1) and a thermoplastic resin (polymer 2) other than the polyester as essential components, wherein micro protrusions having a height of 2 to 50 nm are formed at a density of 1,000,000 to 90,000,000/mm2 on at least one surface.

Abstract: An object of the present invention is to provide a biaxially oriented high quality polyester film excellent in thermal dimensional stability and clarity and also excellent in productivity, and also to provide a production process thereof. Another object is to provide a biaxially oriented polyester film greatly improved in the practical properties respected in various applications of the polyester film, such as the recording track shift in magnetic recording tape application, curling in magnetic recording card application, dimensional change during process in printing plate application, printing shift in ribbon application, thermostability in capacitor application, and perforation sensitivity and low temperature curling in heat-sensitive mimeograph stencil application.

Abstract: A polyester film for use in a capacitor having high heat resistance, which consists of a biaxially oriented film containing a polyester (A) as a main component and a polyimide (B) and has a glass transition temperature of 105° C. to 145° C. and an elongation at break in the machine direction of 70% to 150%, offers a high glass transition temperature and excellent insulation volume resistance and insulation breakdown voltage at high ambient temperatures. This film can produce a metallized film for use in a capacitor having high heat resistance and also a film capacitor having high heat resistance.

Abstract: In order to provide a film having excellent heat resistance, thermal dimensional stability, and mechanical properties, in particular, a film capable of satisfying required properties, e.g., higher strength in accordance with the reduction in thickness of a base film, improved thermal dimensional stability and mechanical properties in a use environment, and higher heat resistance and improved thermal dimensional stability in accordance with the needs for miniaturization and more functionality in electrical and electronic areas, a thermoplastic resin is allowed to contain transition metal oxide particles, and is formed into a biaxially oriented thermoplastic resin film, wherein the melting point of the film is allowed to become higher than the melting point of the thermoplastic resin to be used.

Abstract: The object of this invention is to provide a biaxially oriented polyester film suitable as a base film for high density magnetic recording media, small in track deviation and excellent in traveling durability and preservability, and to provide a production method thereof. The object of this invention can be achieved by a biaxially oriented polyester film, characterized in that the dimensional change rate (A) in the transverse direction of the film is in a range of −0.3 to 0% when the film is allowed to stand at 49° C. and 90% RH for 72 hours, while being loaded with 32 MPa in the machine direction.

Abstract: The present invention provides a polyester film, which is composed of a polyester resin and a polyimide resin, having superior oligomer-restraining property and dimensional stability. This polyester film also has improved surface conditions, that is, has a reduced number of projections on the surface, and hence, the polyester film shows superior electromagnetic conversion characteristics when used for magnetic recording media. In particular, this polyester film is effectively used for high-density magnetic recording media. This film is composed of a polyester resin and a thermoplastic resin other than a polyester resin, and has a number H1 of coarse projections 0.28 &mgr;m or more in height of 0 to 100/100 cm2 on at least one surface of the polyester film and a number H2 of coarse projections 0.56 &mgr;m or more in height of 0 to 10/100 cm2 on the same surface.

Abstract: The object of the present invention is to provide a method for producing a polyester film excellent in rigidity, toughness, dimensional stability, electric properties, etc. and less in thickness fluctuation and surface defects, hence very suitable as a film for various industrial materials such as magnetic recording media, capacitors, heat transfer ribbons and thermal mimeographic stencil paper. The first method of the present invention is a method for producing a polyester film, in which a film made of a resin mainly composed of a polyester is simultaneously biaxially stretched by a simultaneously biaxially stretching tenter oven, comprising the step of effecting small-ratio stretching at an area stretching ratio of 1.0005 to 3.

Abstract: A biaxially oriented polyester film that is 7.0 GPa or more in either the Young's modulus in the machine direction (YmMD) or in the transverse direction (YmTD), and in the range of 55° or more and 85° or less in the circumferential half-width of the diffraction line from the crystal plane in the direction of the polyester's backbone chain that is determined through crystal orientation analysis by wide angle X-ray diffractometry performed while rotating the polyester film around its normal. The film is high in rigidity in all directions within the film plane, high in tear resistance, high in dimensional stability, and resistant to deformation under load, and have very great industrial advantages as material for high-density magnetic recording media, with wide applicability as material for electrostatic capacitor, heat transfer ribbon, and base paper for thermosensitive stencil printing.

Abstract: The object of the present invention is to provide a method for producing a polyester film excellent in rigidity, toughness, dimensional stability, electric properties, etc. and less in thickness fluctuation and surface defects, hence very suitable as a film for various industrial materials such as magnetic recording media, capacitors, heat transfer ribbons and thermal mimeographic stencil paper. The first method of the present invention is a method for producing a polyester film, in which a film made of a resin mainly composed of a polyester is simultaneously biaxially stretched by a simultaneously biaxially stretching tenter oven, comprising the step of effecting small-ratio stretching at an area stretching ratio of 1.0005 to 3.

Abstract: An object of the present invention is to provide a biaxially oriented high quality polyester film excellent in thermal dimensional stability and clarity and also excellent in productivity, and also to provide a production process thereof. Another object is to provide a biaxially oriented polyester film greatly improved in the practical properties respected in various applications of the polyester film, such as the recording track shift in magnetic recording tape application, curling in magnetic recording card application, dimensional change during process in printing plate application, printing shift in ribbon application, thermostability in capacitor application, and perforation sensitivity and low temperature curling in heat-sensitive mimeograph stencil application.

Abstract: The present invention provides a polyester film, which is composed of a polyester resin and a polyimide resin, having superior oligomer-restraining property and dimensional stability. This polyester film also has improved surface conditions, that is, has a reduced number of projections on the surface, and hence, the polyester film shows superior electromagnetic conversion characteristics when used for magnetic recording media. In particular, this polyester film is effectively used for high-density magnetic recording media. This film is composed of a polyester resin and a thermoplastic resin other than a polyester resin, and has a number H1 of coarse projections 0.28 &mgr;m or more in height of 0 to 100/100 cm2 on at least one surface of the polyester film and a number H2 of coarse projections 0.56 &mgr;m or more in height of 0 to 10/100 cm2 on the same surface.

Abstract: The objects of the present invention can be achieved by a biaxially oriented polyester film, comprising a polyester (A) mainly composed of ethylene terephthalate and a polyether imide (B), having a single glass transition temperature, and having a refractive index of 1.60 to 1.80 at least in either the machine direction or the transverse direction.

Abstract: Disclosed is a biaxially oriented polyester film that is 7.0 GPa or more in either the Young's modulus in the machine direction (YmMD) or in the transverse direction (YmTD), and in the range of 55° to 85° in the circumferential half-width of the diffraction line from the crystal plane in the direction of the polyester's backbone chain that is determined through crystal orientation analysis by wide angle X-ray diffractometry performed while rotating the polyester film around its normal. The film is high in rigidity in all directions within the film plane, high in tear resistance, high in dimensional stability, and resistant to deformation under load, and have very great industrial advantages as material for high-density magnetic recording media, with wide applicability as material for electrostatic capacitor, heat transfer ribbon, and base paper for thermosensitive stencil printing.