Abstract: An object of the present invention is to more conveniently provide a copolyester for a polyester film which exhibits excellent dimensional stability and in particular excellent dimensional stability against environmental changes in, for example, temperature and humidity, and has a small film elongation percentage at 110° C. A copolyester of the present invention comprises: (A) an aromatic dicarboxylic acid component; (B) an alkylene glycol component; and (C1) a dimer acid component and/or (C2) a dimer diol component, wherein the copolyester contains, with reference to a molar number of a total dicarboxylic acid component, 0.5 to 3.5 mol % of the dimer acid component (C1) and/or 0.3 to 5.0 mol % of the dimer diol component (C2).

Abstract: A multi-layer, layered film includes a multi-layer, alternately layered body containing birefringent first layers including a first resin and isotropic second layers including a second resin, in which the multi-layer, layered film has a layer thickness profile with which light at a wavelength of from 380 to 780 nm can be reflected due to optical interference between each of the first layers and each of the second layers, in which a layer thickness profile for an optical thickness of the first layers has a first monotonically increasing region which meets specific requirements, and in which a layer thickness profile for an optical thickness of the second layers has a second monotonically increasing region which meets specific requirements.

Abstract: The invention provides a multilayer laminated film containing a multilayer laminated structure of alternately laminated first and second layers, and a thick film layer in contact therewith. The multilayer laminated structure has a layer thickness profile in terms of the physical thickness of repeating first and second layers. The layer thickness profile has a monotonously increasing thickness region and a thin layer region, which has at least three repeating units, a L2/L1 ratio of 0.85 or less, and a A2/L1 ratio of 0.70 or less, where L1 is the maximum repeating unit thickness in the monotonously increasing thickness region, L2 is the maximum repeating unit thickness in the thin layer region, and A2 is the average repeating unit thickness in the thin layer region. The thin layer region is on the thicker side of the monotonously increasing thickness region and in contact with the thick film layer.

Abstract: The invention provides a multilayer laminated film with alternately laminated birefringent and isotropic layers. The birefringent layers have a first monotonically increasing region of optical thickness and contain monotonically increasing region 1A of maximum optical thickness of 100 nm or less, and monotonically increasing region 1B of minimum optical thickness of more than 100 nm, and ratio 1B/1A of slope 1B of monotonically increasing region 1B to slope 1A of monotonically increasing region 1A is more than 0 and less than 0.8. The isotropic layers have a second monotonically increasing region of optical thickness and contain monotonically increasing region 2A of maximum optical thickness of 200 nm or less and monotonically increasing region 2B of minimum optical thickness of more than 200 nm, and ratio 2B/2A of slope 2B of monotonically increasing region 2B to slope 2A of monotonically increasing region 2A is more than 1.5 and 10 or less.

Abstract: A laminate having an easy-to-adhere layer on at least one face of a resin substrate film, and having a heat seal layer on a face, of at least one of the easy-to-adhere layer(s), which is on a side opposite the resin substrate film, wherein the resin substrate film has a glass transition temperature of not less than 90° C.; the easy-to-adhere layer is formed from easy-to-adhere agent containing 100 parts by weight of acrylic polymer resin and 3-40 parts by weight of crosslinking agent; the acrylic polymer resin has methylol groups in an amount of 7-20 mol % of all monomer units that make up this polymer; the crosslinking agent is at least one crosslinking agent selected from oxazoline-type crosslinking agents and glycidylamine-type crosslinking agents; and the heat seal layer is a polyolefin-type heat seal layer with a thickness of less than 300 ?m.

Abstract: To provide a resin film, of which dimensional stability required of an ultra-high density recording medium can be controlled easily by drive tension, and which has processability at high temperature in a processing step of the resin film into a magnetic recording medium. A resin film having a Young's modulus in the film longitudinal direction of 1 GPa or more and a film thickness of 1 ?m or more, wherein the product of the Young's modulus in the longitudinal direction and the thickness is 5 GPa·?m or more and 20 GPa·?m or less and wherein a dimensional change in the film longitudinal direction is ?2% or more and +2% or less when the film is heated at a rate of 5° C./min under a load of 2 kg/mm2 applied in the longitudinal direction and the temperature has reached 110° C., the resin film satisfying at least either of the following (1) or (2): (1) the Young's modulus in the film longitudinal direction is 6 GPa or less and the film thickness is 4.

Abstract: A laminated film has a multilayer structure with outermost layers 1 and 2 composed mainly of a resin, wherein the multilayer structure has first and second layers alternately laminated in the thickness direction so that the total number of the first and second layers is 30 or more, the first layer is a birefringent layer composed mainly of a resin and is 10-1,000 nm thick, the second layer is an isotropic layer composed mainly of a resin and is 10-1,000 nm thick, the thicknesses of the first and second layers increase along the thickness direction from the outermost layer 2 side to the outermost layer 1 side, the total thickness of the outermost layers is 10% or more of the total thickness of the multilayer structure, and the thickness of the outermost layer 1 is larger than the thickness of the outermost layer 2.

Abstract: An object of the present invention is to more conveniently provide a copolyester for a polyester film which exhibits excellent dimensional stability and in particular excellent dimensional stability against environmental changes in, for example, temperature and humidity, and has a small film elongation percentage at 110° C. A copolyester of the present invention comprises: (A) an aromatic dicarboxylic acid component; (B) an alkylene glycol component; and (C1) a dimer acid component and/or (C2) a dimer diol component, wherein the copolyester contains, with reference to a molar number of a total dicarboxylic acid component, 0.5 to 3.5 mol % of the dimer acid component (C1) and/or 0.3 to 5.0 mol % of the dimer diol component (C2).

Abstract: The invention provides a multilayer laminated film in which a birefringent layer comprising a first resin and an isotropic layer comprising a second resin are alternately laminated. The multilayer laminated film reflects light at a wavelength of 380-780 nm. A series of the birefringent layers has an optical thickness monotonically increasing region in which the 0.8×mth layer has an optical thickness of 140-180 nm, wherein the first and mth layers are the thinnest and thickest layers with optical thicknesses of 100 nm or more and 190 nm or less, respectively. A series of the isotropic layers has an optical thickness monotonically increasing region in which the 0.8×nth layer has an optical thickness of 150-280 nm, wherein the first and nth layers are the thinnest and thickest layers with optical thicknesses of 120 nm or more and 350 nm or less, respectively.

Abstract: A laminate having an easy-to-adhere layer on at least one face of a resin substrate film, and having a heat seal layer on a face, of at least one of the easy-to-adhere layer(s), which is on a side opposite the resin substrate film, wherein the resin substrate film has a glass transition temperature of not less than 90° C.; the easy-to-adhere layer is formed from easy-to-adhere agent containing 100 parts by weight of acrylic polymer resin and 3-40 parts by weight of crosslinking agent; the acrylic polymer resin has methylol groups in an amount of 7-20 mol % of all monomer units that make up this polymer; the crosslinking agent is at least one crosslinking agent selected from oxazoline-type crosslinking agents and glycidylamine-type crosslinking agents; and the heat seal layer is a polyolefin-type heat seal layer with a thickness of less than 300 ?m.

Abstract: The invention provides a multilayer laminated film containing a multilayer laminated structure of alternately laminated first and second layers, and a thick film layer in contact therewith. The multilayer laminated structure has a layer thickness profile in terms of the physical thickness of repeating first and second layers. The layer thickness profile has a monotonously increasing thickness region and a thin layer region, which has at least three repeating units, a L2/L1 ratio of 0.85 or less, and a A2/L1 ratio of 0.70 or less, where L1 is the maximum repeating unit thickness in the monotonously increasing thickness region, L2 is the maximum repeating unit thickness in the thin layer region, and A2 is the average repeating unit thickness in the thin layer region. The thin layer region is on the thicker side of the monotonously increasing thickness region and in contact with the thick film layer.

Abstract: A multi-layer, layered film includes a multi-layer, alternately layered body containing birefringent first layers including a first resin and isotropic second layers including a second resin, in which the multi-layer, layered film has a layer thickness profile with which light at a wavelength of from 380 to 780 nm can be reflected due to optical interference between each of the first layers and each of the second layers, in which a layer thickness profile for an optical thickness of the first layers has a first monotonically increasing region which meets specific requirements, and in which a layer thickness profile for an optical thickness of the second layers has a second monotonically increasing region which meets specific requirements.

Abstract: A laminated film has a multilayer structure with outermost layers 1 and 2 composed mainly of a resin, wherein the multilayer structure has first and second layers alternately laminated in the thickness direction so that the total number of the first and second layers is 30 or more, the first layer is a birefringent layer composed mainly of a resin and is 10-1,000 nm thick, the second layer is an isotropic layer composed mainly of a resin and is 10-1,000 nm thick, the thicknesses of the first and second layers increase along the thickness direction from the outermost layer 2 side to the outermost layer 1 side, the total thickness of the outermost layers is 10% or more of the total thickness of the multilayer structure, and the thickness of the outermost layer 1 is larger than the thickness of the outermost layer 2.

Abstract: A colored biaxially stretched polyester film for metal plate attachment and forming processing, includes three layers: opposite surface layers (layers A) that contain substantially no coloring pigment and are made of a copolyester having an intrinsic viscosity of 0.65 to 0.80 and a melting point (TmA) of 230 to 260° C.; and a core layer (layer B) that has a coloring pigment content of more than 10 wt % and 50 wt % or less and is made of a copolyester having an intrinsic viscosity of 0.55 to 0.70 and a melting point (TmB) of 230 to 260° C. The film has a surface roughness within a range of 10 to 40 nm, and (TmB?TmA) is 4° C. or less.

Abstract: To provide a resin film, of which dimensional stability required of an ultra-high density recording medium can be controlled easily by drive tension, and which has processability at high temperature in a processing step of the resin film into a magnetic recording medium. A resin film having a Young's modulus in the film longitudinal direction of 1 GPa or more and a film thickness of 1 ?m or more, wherein the product of the Young's modulus in the longitudinal direction and the thickness is 5 GPa·?m or more and 20 GPa·?m or less and wherein a dimensional change in the film longitudinal direction is ?2% or more and +2% or less when the film is heated at a rate of 5° C./min under a load of 2 kg/mm2 applied in the longitudinal direction and the temperature has reached 110° C., the resin film satisfying at least either of the following (1) or (2): (1) the Young's modulus in the film longitudinal direction is 6 GPa or less and the film thickness is 4.

Abstract: A colored biaxially stretched polyester film for metal plate attachment and forming processing, includes three layers: opposite surface layers (layers A) that contain substantially no coloring pigment and are made of a copolyester having an intrinsic viscosity of 0.65 to 0.80 and a melting point (TmA) of 230 to 260° C.; and a core layer (layer B) that has a coloring pigment content of more than 10 wt % and 50 wt % or less and is made of a copolyester having an intrinsic viscosity of 0.55 to 0.70 and a melting point (TmB) of 230 to 260° C. The film has a surface roughness within a range of 10 to 40 nm, and (TmB?TmA) is 4° C. or less.

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 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 polyester film roll is rolled on a core, wherein the difference R (m) between the maximum value and the minimum value of the diameters of the roll is not more than 2W×10?3 and not more than L×10?7, when the diameters of said roll are measured in the width direction of the roll, (therein, W is the width (m) of the film roll, and L is the length (m) of the rolled film). Alternatively, among the lengths of lines which are obtained by measuring the diameters of said roll in the width direction of the roll, drawing a straight line between both the ends of the curved line of the obtained roll diameters, the maximum distance on the convex portion between the curved and straight lines is not more than 500 ?m, and the maximum distance on the concave portion of the same is not more than 300 ?m.

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.