Toyobo Co., Ltd.

Shotaro Nishio

Kiwamu Kawai

Akira Shimizu

Mei Matsumura

Katsuya Ito

Kokichi Tokuo

Yohei Yamaguchi

Jun Inagaki

Shinji Sawasaki

Kenji Yoshino

In order to provide a foldable display that is suitable for mass production and that has no risk of image distortion at its folding portion after the display is repeatedly folded, the invention provides a polyester film for foldable displays in which no cracks occurs in the folding portion. In particular, the invention provides a polyester film for a foldable display, the film having a thickness of 10-125 μm and a high-temperature hold angle in a bending direction of 70° or more, wherein the high-temperature hold angle refers to an angle of a crease formed after fixing the film at a heating temperature of 85° C. for 18 hours in such a manner that a strain of 1.7% is applied to both surfaces of a bent portion of the film, and the bending direction refers to a direction that is orthogonal to a folding portion.

Polyester film and use thereof

[Problem] To provide a cavity-containing polyester film which exhibits excellent concealability, degree of whiteness and printability, and which is still free from the occurrence of a wrinkle, distortion and the like in cases where, for example, the cavity-containing polyester film is used for a roll label, and a label is delivered therefrom or wound around a product. [Solution] A cavity-containing polyester film which comprises a layer A that internally contains a cavity, and layers B that are arranged on both surfaces of the layer A, wherein: the layer A is formed of a composition A that contains a polyester resin A and a polypropylene resin; the layers B are formed of a composition B that contains inorganic particles and a polyester resin B; and the amount of self-weight deflection of the film is from 60 mm to 100 mm at least in one direction.

Cavity-containing polyester film

Provided is a hard coating film for foldable displays that does not form creases or cracks in the folding portion, and that is also excellent in reducing iridescent colors (interference mottling) caused by fine cracks in an easy-to-adhere resin layer or other layers. The hard coating film for foldable displays contains a polyester film having a thickness of 10 to 80 μm, an easy-to-adhere resin layer, and a hard coating layer, the easy-to-adhere resin layer and the hard coating layer being stacked in this order on at least one surface of the polyester film, wherein the easy-to-adhere resin layer is a cured product of a composition containing at least one compound selected from the group consisting of titanium compounds and zirconium compounds and a polyester resin, and the polyester film having the easy-to-adhere resin layer stacked thereon but not yet having the hard coating layer stacked thereon satisfies characteristics within specific ranges.

Hard coat film for foldable display and use thereof

Provided is a transparent conductive polyester film for a foldable display which is free of occurrence of a fold mark or a tear at a folding portion thereof to be used in a foldable display excellent in mass productivity, and free of a risk of causing distortion in an image displayed at a folding portion thereof, and a mobile device. The transparent conductive polyester film for a foldable display includes: a polyester film; and a transparent conductive layer laminated on at least one surface of the polyester film, wherein the polyester film satisfies the following conditions: (1) a refractive index in a bending direction is from 1.590 to 1.620; (2) a refractive index in a folding portion direction is from 1.670 to 1.700; (3) a refractive index in a thickness direction is 1.520 or less; and (4) a density is 1.380 g/cmor more, wherein the bending direction refers to a direction orthogonal to a folding portion of the polyester film at a time when the polyester film is folded.

Transparent conductive polyester film and use of same

Problem: An object of the present invention is to provide a polyester film for a foldable display, the film having a hold angle in a bending direction of 155° or more and a maximum heat shrinkage at 150° C. of 1.5% or less (wherein the hold angle refers to an angle of a crease after fixing the film at room temperature for 72 hours in such a manner that a strain of 1.7% is applied to both surfaces of a bent portion of the film, and the bending direction refers to a direction that is orthogonal to a folding portion of a foldable display produced using the film.

Provided is a hard coating film for foldable displays that does not form creases or cracks in the folding portion, and that is also excellent in reducing iridescent colors (interference mottling) caused by fine cracks in an easy-to-adhere resin layer or other layers. The hard coating film for a foldable display contains a polyester film having a thickness of 10 to 80 μm, an easy-to-adhere resin layer, and a hard coating layer, the easy-to-adhere resin layer and the hard coating layer being stacked in this order on at least one surface of the polyester film, wherein the easy-to-adhere resin layer is a cured product of a composition containing a binder resin and at least one type of particles selected from the group consisting of titanium oxide particles, zirconium oxide particles, and silica particles, the at least one type of particles have a mean particle size of 5 to 150 nm, and the polyester film having the easy-to-adhere resin layer stacked thereon but not yet having the hard coating layer stacked thereon satisfies specific conditions.

Hard coating film for foldable display, and application of said film

Provided is a foldable display excellent in mass productivity, and free of a risk of causing distortion in an image displayed at a folding portion thereof after being repeatedly folded. The foldable display includes at least: a surface protective film; a polarizer; and a retardation layer, wherein the surface protective film is a polyester film satisfying the following conditions and having a thickness of from 10 μm to 80 μm: (1) a refractive index in a bending direction is from 1.590 to 1.620; (2) a refractive index in a folding portion direction is from 1.670 to 1.700; (3) a refractive index in a thickness direction is 1.520 or less; and (4) a density is 1.380 g/cmor more, wherein the bending direction refers to a direction orthogonal to a folding portion of the polyester film at a time when the polyester film is folded.

Foldable display

Provided is a polyester film for foldable displays that is unlikely to have cracks in the folding portion with the aim of providing a foldable display that is excellent in mass production applicability, and that does not have image distortion that may appear in the folding portion after the display is repeatedly folded. The polyester film has a thickness of 10 to 80 μm, a refractive index in the bending direction of 1.590 to 1.620, a refractive index in the direction of a folding portion of 1.670 to 1.700, a refractive index in the thickness direction of 1.520 or less, and a density of 1.380 g/cmor more, wherein the bending direction refers to a direction orthogonal to the folding portion of the polyester film to be folded.

Provided is a laminated film for a foldable display, the laminated film being free of occurrence of a fold mark or a crack at a folding portion thereof, in order to provide, for example, a foldable display excellent in mass productivity, and free of a risk of causing distortion in an image displayed at a folding portion thereof after being repeatedly folded. The laminated film for a foldable display includes: a polyester film having a thickness of from 10 μm to 100 μm; and an adhesive layer formed on at least one surface of the polyester film, wherein the polyester film satisfies the following conditions: (1) a refractive index in a bending direction is from 1.590 to 1.620; (2) a refractive index in a folding portion direction is from 1.670 to 1.700; (3) a refractive index in a thickness direction is 1.520 or less; and (4) a density is 1.380 g/cmor more, wherein the bending direction refers to a direction orthogonal to a folding portion of the polyester film at a time when the polyester film is folded.

Multilayer film and use of same

Provided is a foldable display that is excellent in mass production applicability and unlikely to have image distortion at the folding portion of the display after repeated folding, as well as a mobile device equipped therewith. The foldable display contains a surface protection film and a polarizer. The surface protection film is composed of a polyester film, and the angle made by the slow axis of the polyester film with the absorption axis of the polarizer is 10 to 80°. The polyester film has a refractive index in the bending direction of 1.590 to 1.620, a refractive index in the direction of a folding portion of 1.670 to 1.700, a refractive index in the thickness direction of 1.520 or less, and a density of 1.380 g/cmor more, wherein the bending direction refers to a direction orthogonal to the folding portion of the polyester film to be folded.

Foldable display and portable terminal device

Provided is a polyester film for a touchscreen module substrate of a foldable display which is free of occurrence of a crack at a folding portion thereof, in order to provide a foldable display excellent in mass productivity, and free of a risk of causing distortion in an image displayed at a folding portion thereof after being repeatedly folded. The polyester film for a touchscreen module substrate of a foldable display satisfies the following conditions: (1) a refractive index in a bending direction is from 1.590 to 1.620; (2) a refractive index in a folding portion direction is from 1.670 to 1.700; (3) a refractive index in a thickness direction is 1.520 or less; and (4) a density is 1.380 g/cm or more, wherein the bending direction refers to a direction orthogonal to a folding portion of the polyester film at a time when the polyester film is folded.

Polyester film and application therefor

Provided are a polyester film, a laminated film, and the like for protecting an organic EL module of a foldable display each of which is free of occurrence of a crack at a folding portion thereof, in order to provide a foldable display excellent in mass productivity, and free of a risk of causing distortion in an image displayed at a folding portion thereof after being repeatedly folded. The polyester film for protecting an organic EL module of a foldable display satisfies the following conditions: (1) a refractive index in a bending direction is from 1.590 to 1.620; (2) a refractive index in a folding portion direction is from 1.670 to 1.700; (3) a refractive index in a thickness direction is 1.520 or less; and (4) a density is 1.380 g/cmor more, wherein the bending direction refers to a direction orthogonal to a folding portion of the polyester film at a time when the polyester film is folded.

Polyester film, laminated film, and use thereof

Provided are a foldable display that is excellent in mass production applicability, and that does not have image distortion that can appear in the folding portion after the display is repeatedly folded; and a mobile device equipped with such a foldable display. Provided are a polyester film for surface protection films and a hard coating film for surface protection films for the foldable display and mobile device. The polyester film is for foldable display surface protection films, wherein the polyester film is cut in sheet form, the polyester film has a thickness of 10 to 75 μm, the polyester film has an intrinsic viscosity of 0.55 to 0.65 dl/g, and the amount of rise of a cut plane on at least one side of one or more cut end portions is 35 μm or less. The hard coating film, the foldable display, and the mobile device use the polyester film for foldable display surface protection films.

Polyester film for surface protection film of foldable display and use thereof

The object of the present invention is to provide a white polyester film for a solar cell that is excellent in transfer-mark concealment properties (properties that transferred irregularities are hard to be seen) while having high whiteness, and exhibiting good light resistance and hydrolysis resistance, a sealing sheet for a back surface of a solar cell and a solar cell module using the same. The white polyester film for a solar cell of the present invention has whiteness of 50 or more, an average reflectance of 50 to 95% in a range of wavelength of 400 to 800 nm, an acid value of 1 to 50 eq/ton, and a thickness of 30 to 380 &#x3bc;m, and the film has a multilayer structure in which a polyester resin layer containing inorganic fine particles in an amount of 10 to 38% by mass is disposed as at least one outermost layer, and a half-value width of protrusion distribution on a surface of the polyester resin layer is 200 to 1000 nm, the protrusion distribution being obtained by plotting the number density of protrusions with respect to protrusion height.

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Tsuruga, Japan

Shotaro Nishio