CN115812168A

CN115812168A - Optical film, panel unit, and display device

Info

Publication number: CN115812168A
Application number: CN202180048375.3A
Authority: CN
Inventors: 岛田光星; 梅田博纪
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 2020-07-07
Filing date: 2021-06-07
Publication date: 2023-03-17
Also published as: JP2023106441A; JPWO2022009581A1; TW202212936A; KR20230019204A; WO2022009581A1; JP7276613B2; TWI780774B

Abstract

The invention provides a method for achieving both an effect of suppressing a decrease in image quality and sufficient brightness from a joint between panel units in a display device having a display surface constituted by a plurality of panel units. The present invention relates to a film for use in a display device having a display surface formed of a plurality of panel units, the film including a light-transmitting layer containing particles and a colorant and having a total light transmittance of 10% to 30%.

Description

Optical film, panel unit, and display device

Technical Field

The present invention relates to an optical film for a display device having a display surface constituted by a plurality of panel units, a panel unit for the display device, and the display device.

Background

As a next-generation display device that replaces various liquid crystal display devices, a self-light-emitting display device represented by a Micro LED display device described in japanese patent application laid-open No. 2018-14481 (corresponding to U.S. patent application publication No. 2018/0019233, U.S. patent application publication No. 2018/0331085, or U.S. patent application publication No. 2018/0331086) has been developed.

In such a self-luminous display, in order to avoid adverse effects of light reflected on a substrate or the like on which light-emitting elements as light sources are mounted on the display quality of a displayed image, it has been studied to laminate a light-shielding layer that absorbs visible light on the display surface side of a light-emitting module including the light-emitting elements.

Jp 2019-204905 a discloses a self-luminous display including a light-emitting module in which a plurality of light-emitting elements are mounted on a wiring board, a black sealing material sheet containing an olefin resin as a base resin and having a visible light transmittance of 5% to 70%, and a transparent optical layer (light-transmitting layer). In the self-luminous display, a black sealing material sheet is laminated on the light emitting module so as to cover the surfaces of the light emitting element and the wiring substrate, and a transparent optical layer is laminated on the black sealing material sheet. Further, this document discloses that such a black sealing material sheet exhibits excellent characteristics as a light shielding layer, and the layer configuration of the self-luminous display body can be simplified as compared with the conventional self-luminous display body, as a result of which the productivity of the self-luminous display body can be improved.

Disclosure of Invention

According to the black sealing material sheet of japanese patent application laid-open No. 2019-204905, when used in a display device having a display surface constituted by a plurality of panel units, it is possible to suppress a decrease in image quality resulting from a joint between the panel units. However, in a display device using the black sealing material sheet of japanese patent laid-open No. 2019-204905, there is a problem that luminance is greatly reduced.

Therefore, an object of the present invention is to provide a display device having a display surface constituted by a plurality of panel units, wherein a reduction in image quality resulting from seams between the panel units can be suppressed and sufficient luminance can be obtained at the same time.

The above problems of the present invention can be solved by the following means.

An optical film comprising a light-transmitting layer containing particles and a colorant and having a total light transmittance of 10% to 30%,

a display device having a display surface constituted by a plurality of panel units.

Drawings

Fig. 1 (a) to (C) are schematic views each showing a cross-sectional structure of an optical film used in one embodiment of the present invention. The numeral 1 denotes a light-transmitting layer a described later, 2 denotes a laminated film, 3 denotes a light-transmitting layer B described later, 3' denotes a layer or film which is a base (foundation) of the light-transmitting layer B, and 4 denotes a hard coat layer.

Fig. 2 is a schematic view showing an example of an apparatus for manufacturing an optical film according to an embodiment of the present invention. 100 denotes a laminate (laminated film), 110 denotes a support (e.g., a substrate layer such as a light-transmissive layer B), 200 denotes a manufacturing apparatus, 201 denotes a roller body of the support (e.g., a substrate layer such as a light-transmissive layer B), 210 denotes a supply portion, 220 denotes an application portion, 221 denotes a support roller, 222 denotes an application head, 223 denotes a decompression chamber, 230 denotes a drying portion, 231 denotes a drying chamber, 232 denotes an inlet port for drying gas, 233 denotes an outlet port, 240 denotes a cooling portion, 241 denotes a cooling chamber, 242 denotes a cooling air inlet, 243 denotes a cooling air outlet, 250 denotes a winding portion, 251 denotes a roller body of the laminate (laminated film), and a, B, c, and d denote conveying rollers.

Fig. 3 is a schematic diagram showing a cross-sectional structure of a panel unit according to an embodiment of the present invention. 1 denotes a light-transmitting layer a described later, 2 denotes a laminated film, 3 denotes a light-transmitting layer B described later, 3' denotes a layer or a film which is a base (base) of the light-transmitting layer B, 4 denotes a hard coat layer, 10 denotes a panel unit, 11 denotes an LED module, and 12 denotes an adhesive layer.

Fig. 4 is a schematic view showing a planar structure of a display device of a standalone module type according to an embodiment of the present invention. A panel unit is denoted by 10, and a display device of a separate module type is denoted by 20.

Detailed Description

In the present specification, "X to Y" indicating a range means "X to Y. Unless otherwise specified, the operation and physical properties were measured under conditions of room temperature (20 to 25 ℃)/relative humidity 40 to 50% RH.

In addition, in the present specification, the term (co) polymer refers to a generic term including copolymers and homopolymers.

In the present specification, "(meth) acrylate" refers to a generic name of acrylate and methacrylate. Compounds containing (meth) groups such as (meth) acrylic acid are also a general term for compounds having "methyl" in the name and compounds not having "methyl" in the same manner.

Hereinafter, embodiments of the present invention will be described with reference to the drawings as necessary. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. In addition, the dimensional ratio in the drawings is exaggerated for convenience of explanation, and may be different from the actual ratio.

< light-transmitting layer A >

One embodiment of the present invention relates to an optical film including a light-transmitting layer containing particles and a colorant and having a total light transmittance of 10% to 30%, the optical film being used for a display device having a display surface constituted by a plurality of panel units. According to one aspect of the present invention, there is provided a mechanism capable of achieving both an effect of suppressing a decrease in image quality and sufficient luminance from a joint between panel units in a display device having a display surface constituted by a plurality of panel units.

In the present specification, a layer containing particles and a colorant and having a total light transmittance of 10% to 30% is also referred to as a light-transmitting layer a.

The present inventors speculate that the mechanism of the problem that can be solved by the present invention is as follows.

In a display device having a display surface constituted by a plurality of panel units, if external light enters the device, the external light is reflected by a substrate or the like on which a light emitting element serving as a light source is mounted, and reflected light is generated. In the joint between the panel units, for example, the reflected light is reflected or refracted by the side surface of the adjacent panel unit, and is emitted to the display surface side, and local scattering of light is observed. Such local light scattering causes degradation of image quality at the joints between the panel units.

Since the black sealing material sheet of jp 2019-204905 has a function of absorbing visible light, it absorbs reflected light reflected by a substrate or the like on which a light-emitting element as a light source is mounted, thereby reducing reflected light toward the display surface side, and also reducing emitted scattered light. This suppresses degradation in image quality resulting from seams between the panel units. However, the black sealing material sheet of jp 2019-204905 a absorbs most of the light emitted from the light emitting element serving as a light source, and therefore, in a panel unit or a display device provided with such a sheet, the luminance is greatly reduced.

On the other hand, in the present invention, the light-transmitting layer a contains a colorant, and has a total light transmittance of 10% to 30%. Since the light-transmitting layer a has a function of absorbing visible light in an appropriate range, reflected light reflected by a substrate or the like on which a light-emitting element serving as a light source is mounted is absorbed to reduce reflected light toward the display surface side, and emitted scattered light is also reduced. The absorption amount of the emitted light emitted from the light emitting element as the light source is also equal to or less than a certain value. Therefore, sufficient luminance can be obtained in a panel unit or a display device including the optical film of the present invention. In the present invention, the light-transmitting layer a includes particles. Since the particles scatter the entire reflected light reflected by the substrate or the like on which the light-emitting element as the light source is mounted, even when light is scattered at the joint between the panel units, the light scattering becomes less noticeable than when light is locally scattered only at the part. Further, since the light emitted from the light emitting element as a light source is also scattered to some extent, even when the light is scattered at the joint between the panel units, the scattering of the light is less noticeable.

It should be noted that the above mechanism is a pure assumption, and whether it is correct or not does not affect the technical scope of the present invention.

(base Material)

The light-transmitting layer a according to one embodiment of the present invention preferably contains a base material. The matrix material imparts self-supporting properties to the film and plays a role of holding particles in the film.

The content of the base material is not particularly limited, but is preferably more than 50% by mass, more preferably more than 80% by mass, and still more preferably more than 90% by mass, based on the total mass of the light-transmitting layer a, from the viewpoint of light transmittance. The content of the base material is preferably less than 100% by mass based on the total mass of the light-transmissive layer a from the viewpoint of light absorption and light scattering.

The substrate is not particularly limited, and may be an inorganic material or an organic material, and is preferably an organic material.

The light-transmitting layer a is preferably a light-transmitting resin layer such as a resin film. The light-transmitting resin layer means a light-transmitting layer containing a resin as a base material, and the resin film means a film containing a resin as a base material. The resin as the matrix material is not particularly limited, and examples thereof include acrylic resins (e.g., methyl methacrylate-methyl acrylate copolymer resin, etc.), polycarbonate resins, polyolefin resins (e.g., polyethylene resin, polypropylene resin, etc.), cycloolefin resins (COP), polyimide resins, cellulose resins (e.g., cellulose triacetate, cellulose diacetate, cellulose acetate propionate, etc.), polyester resins (e.g., polyethylene terephthalate (PET), polypropylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), etc.), and the like. Among them, the cycloolefin resin is preferable from the viewpoint of the haze value and the optical uniformity, and the cycloolefin resin having a polar group is more preferable from the viewpoint of the dispersibility of the inorganic particles and the colorant (particularly, the pigment). Examples of the polar group include a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, a cyano group, a group in which these groups are bonded via a connecting group such as a methylene group, and a hydrocarbon group in which a polar 2-valent organic group such as a carbonyl group, an ether group, a silyl ether group, a thioether group, or an imine group is bonded as a connecting group. Among these groups, cycloolefin resins having a carboxyl group are preferable. In the case where the polar group is a group capable of forming a salt, the polar group may form a salt.

The cycloolefin resin is not particularly limited, and is preferably a (co) polymer of a cycloolefin monomer represented by the following general formula (a).

Each R in the general formula (A) independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, or a polar group. In the general formula (A), a and b each independently represent an integer of 0 or more.

Further, as the cycloolefin resin, a (co) polymer of a cycloolefin monomer represented by the following general formula (A-1) or the following general formula (A-2) is more preferable.

First, a cycloolefin monomer represented by the general formula (A-1) will be explained.

General formula (A-1)

R of the formula (A-1) ¹ ～R ⁴ Each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, or a polar group. Wherein, except for R ¹ ～R ⁴ All being hydrogen atoms, R being absent ¹ And R ² And are simultaneously hydrogen atoms or R ³ And R ⁴ And at the same time, a hydrogen atom.

The halogen atom is not particularly limited, and is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. The hydrocarbon group having 1 to 30 carbon atoms is not particularly limited, but is preferably an alkyl group having 1 to 30 carbon atoms. The polar group is not particularly limited, and is preferably a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, or a cyano group, and a hydrocarbon group in which a polar 2-valent organic group such as a carbonyl group, an ether group, a silyl ether group, a thioether group, or an imine group is bonded as a connecting group, and a group in which these groups are bonded via a connecting group such as a methylene group. Of these groups, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, or an allyloxycarbonyl group is more preferable. From the viewpoint of ensuring solubility in solution film formation, an alkoxycarbonyl group or an allyloxycarbonyl group is more preferable.

From the viewpoint of ensuring solubility in solution film formation of cycloolefin resin, R is ¹ ～R ⁴ At least one of them is preferably a polar group.

P in the general formula (A-1) represents an integer of 0 to 2. From the viewpoint of improving the heat resistance of the film, p is preferably 1 to 2. When p is 1 to 2, the volume of the obtained resin becomes large and the glass transition temperature is likely to be high.

Next, the cycloolefin monomer represented by the general formula (A-2) will be described.

General formula (A-2)

R of the formula (A-2) ⁵ Represents an alkylsilyl group having a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms or an alkyl group having 1 to 5 carbon atoms. Wherein R is ⁵ Preferably a hydrocarbon group having 1 to 3 carbon atoms.

R of the formula (A-2) ⁶ Represents a polar group or a halogen atom. The polar group is not particularly limited, and is preferably a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group or a cyano group. The halogen atom is not particularly limited, but is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. In these groups, R ⁶ Preferably a polar group, more preferably a carboxyl group, a hydroxyl group, an alkoxycarbonyl group or an allyloxycarbonyl group. From the viewpoint of ensuring solubility in solution film formation, an alkoxycarbonyl group or an allyloxycarbonyl group is more preferable.

The use of the cycloolefin monomer represented by the general formula (A-2) reduces the molecular symmetry, and facilitates the diffusion movement of the resin when the solvent is volatilized.

In the general formula (A-2), p represents an integer of 0 to 2.

Specific examples of the structures of the general formulae (A-1) and (A-2) are shown below.

Examples of the copolymerizable monomer copolymerizable with the cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) include a copolymerizable monomer copolymerizable with the cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) by ring-opening copolymerization and a copolymerizable monomer copolymerizable with the cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) by addition copolymerization.

Examples of the copolymerizable monomer that can be ring-opening copolymerized with the cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) include other cycloolefin monomers such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, dicyclopentadiene and the like.

Examples of the copolymerizable monomer capable of addition copolymerization with the cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) include compounds having an unsaturated double bond, vinyl cyclic hydrocarbon compounds, and (meth) acrylic acid esters. Examples of the compound having an unsaturated double bond include olefin compounds having 2 to 12 (preferably 2 to 8) carbon atoms, and examples thereof include ethylene, propylene and butene. Examples of the vinyl cyclic hydrocarbon compound include vinyl cyclopentene monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene. Examples of the (meth) acrylic acid ester include alkyl (meth) acrylates having 1 to 20 carbon atoms such as methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, and the like.

The content of the structural unit derived from the cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) is preferably 50 to 100 mol%, more preferably 60 to 100 mol%, and still more preferably 70 to 100 mol% based on the total of the structural units constituting the cycloolefin resin.

The cycloolefin resin is preferably a polymer obtained by homopolymerizing or copolymerizing a cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2), and examples thereof include the following polymers. Among these polymers, (1) to (3) and (5) are preferable, and (3) and (5) are more preferable.

(1) A ring-opened polymer of a cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2);

(2) A ring-opened copolymer of a cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) and a copolymerizable monomer;

(3) A reinforced (co) polymer of the ring-opened (co) polymer of the above (1) or (2);

(4) A (co) polymer obtained by cyclizing the ring-opened (co) polymer of the above-mentioned (1) or (2) by a Friedel-crafts reaction and then hydrogenating it;

(5) A copolymer of a cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) and a compound having an unsaturated double bond;

(6) Addition type (co) polymers of cycloolefin monomers represented by the general formula (A-1) or the general formula (A-2) and hydrogenated (co) polymers thereof;

(7) An alternating copolymer of a cycloolefin monomer represented by the general formula (A-1) or the general formula (A-2) and a methacrylate or an acrylate.

The cycloolefin resin includes, for example, a resin having at least one of a structural unit represented by the following general formula (B-1) and a structural unit represented by the following general formula (B-2). Among these polymers, a polymer containing a structural unit represented by the general formula (B-2) or a copolymer of a structural unit represented by the general formula (B-1) and a structural unit represented by the general formula (B-2) is preferable from the viewpoint that the obtained cycloolefin resin has a high glass transition temperature and a film having a high transmittance is easily obtained.

General formula (B-1)

In the general formula (B-1), X is a group represented by-CH = CH-or a group represented by-CH ₂ CH ₂ The group shown. R ¹ ～R ⁴ And p is independently from R of the formula (A-1) ¹ ～R ⁴ And p are the same.

General formula (B-2)

In the general formula (B-2), X is a group represented by-CH = CH-or is represented by-CH% ₂ CH ₂ -a group represented by (a). R of the formula (B-2) ⁵ 、R ⁶ And p is independently from R of the formula (A-2) ⁵ 、R ⁶ And p are the same.

Intrinsic viscosity [ eta ] of cycloolefin resin _inh The length is not particularly limited, but is preferably 0.2 to 5cm ³ A concentration of 0.3 to 3cm ³ Per g, more preferably 0.4 to 1.5cm ³ (ii) in terms of/g. Intrinsic viscosity [ eta ] of cycloolefin resin _inh Can be prepared by JIS K7367-1: 2002.

The number average molecular weight (Mn) of the cycloolefin resin is not particularly limited, and is preferably 8000 to 100000, more preferably 10000 to 80000, and further preferably 12000 to 50000. The weight average molecular weight (Mw) of the cycloolefin resin is not particularly limited, but is preferably 20000 to 300000, more preferably 30000 to 250000, and still more preferably 40000 to 200000. The number average molecular weight (Mn) and the weight average molecular weight (Mw) can be measured in terms of polystyrene by Gel Permeation Chromatography (GPC).

If the intrinsic viscosity [ eta ] _inh When the number average molecular weight and the weight average molecular weight are within the above ranges, the cycloolefin resin is more excellent in heat resistance, water resistance, chemical resistance, mechanical properties, and moldability into a film.

The glass transition temperature (Tg) of the cycloolefin resin is not particularly limited, but is preferably 110 ℃ or higher, more preferably 110 to 350 ℃, further preferably 120 to 250 ℃, and particularly preferably 120 to 220 ℃. If the Tg is 110 ℃ or higher, deformation is less likely to occur by secondary processing such as use under high temperature conditions, coating, printing, and the like. On the other hand, if Tg is 350 ℃ or lower, molding is easier, and the resin is less likely to be deteriorated by heat during molding. The Tg of the cycloolefin resin can be measured by JIS K7121-1987.

The cycloolefin resin may be a commercially available product or a synthesized product. Examples of commercially available products are not particularly limited, and examples thereof include ARTON (registered trademark, the same shall apply hereinafter) G (for example, ARTON G7810), ARTON F, ARTON R, ARTON RX, and the like, manufactured by JSR corporation.

The cycloolefin resin may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Further, 1 kind of the base material may be used alone, or 2 or more kinds may be used simultaneously.

(particles)

The light-transmitting layer a according to one embodiment of the present invention contains particles. The particles are dispersed in the light-transmitting layer a, and thereby function to scatter light transmitted through the optical film. Therefore, in a display device having a display surface constituted by a plurality of panel units, when the light-transmitting layer a does not contain particles, the deterioration of image quality due to the joints between the panel units is not sufficiently suppressed.

In the present specification, the particles do not contain a colorant described later.

The particles are not particularly limited, and examples thereof include organic particles, inorganic particles, and organic-inorganic composite particles.

The organic particles are not particularly limited, and examples thereof include polymethyl methacrylate beads, acrylic-styrene copolymer beads, melamine beads, polycarbonate beads, styrene beads, crosslinked polystyrene beads, polyvinyl chloride beads, benzoguanamine-melamine formaldehyde beads, and the like.

The inorganic particles are not particularly limited, and examples thereof include inorganic oxide particles composed of at least one oxide selected from zirconium, titanium, aluminum, indium, zinc, tin, antimony, cerium, niobium, tungsten, silicon, and the like. Specific examples thereof include ZrO ₂ 、ZrSiO ₄ 、TiO ₂ 、BaTiO ₃ 、SrTiO ₃ 、Al ₂ O ₃ Zeolite, in ₂ O ₃ 、ITO(Indium Tin Oxide)、ZnO、SnO ₂ 、Sb ₂ O ₃ 、CeO ₂ 、Nb ₂ O ₅ 、WO ₃ Silicon dioxide (SiO) ₂ ) And the like.

Of these particles, inorganic particles are preferable, inorganic oxide particles are more preferable, silicon-containing oxide is further preferable, and Silica (SiO) is particularly preferable ₂ )。

In addition, the particles may have a multilayer structure typified by a core-shell structure.

These particles may be used with or without surface treatment.

In the case of surface treatment, specific materials for surface treatment include various inorganic oxides such as silica and zirconia, metal hydroxides such as aluminum hydroxide, organic acids such as organosiloxane and stearic acid. These surface-treated materials may be used alone in 1 kind or in combination of plural kinds. Among them, from the viewpoint of stability of the dispersion, the material for surface treatment is preferably at least one of different types of inorganic oxides and metal hydroxides, and more preferably a metal hydroxide.

The average secondary particle diameter of the particles is not particularly limited, but is preferably 50nm or more, more preferably 100nm or more, and further preferably 150nm or more. Within such a range, the effect of suppressing the deterioration of the image quality due to the joint between the panel units is further improved. The average secondary particle diameter of the particles is preferably 1000nm or less, more preferably 500nm or less, and still more preferably 300nm or less. Within such a range, the effect of suppressing the deterioration of the image quality, which is unclear as a whole, is further improved.

The average secondary particle size of the particles can be determined by directly measuring the size of the secondary particles from an electron micrograph of the layer. Specifically, the particle image was measured by a Transmission Electron Micrograph (TEM) (H-7650, hitachi-tech, ltd.) to obtain an average value of the equivalent circle diameters of 100 randomly selected secondary particles, and the average value was defined as the average secondary particle diameter.

The particles may be commercially available or synthesized. The commercially available product is not particularly limited, and examples thereof include R972V manufactured by AEROSIL K.K.Japan.

The particles may be used alone in 1 kind, or 2 or more kinds may be used simultaneously.

The content of the particles in the light-transmitting layer a is not particularly limited, and is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, further preferably 0.1 parts by mass or more, and particularly preferably 0.3 parts by mass or more, relative to 100 parts by mass of the base material. Within this range, the effect of suppressing the deterioration of the image quality due to the joint between the panel units is further improved. The content of the particles in the light-transmitting layer a is not particularly limited, but is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 1 part by mass or less, relative to 100 parts by mass of the base material. Within such a range, the effect of suppressing the deterioration of the image quality, which is unclear as a whole, is further improved.

(coloring agent)

The light-transmitting layer a according to one embodiment of the present invention contains a colorant. The colorant plays a role of controlling the total light transmittance of the optical film by coloring the light-transmitting layer a. Therefore, in a display device having a display surface constituted by a plurality of panel units, in the case where the light-transmitting layer a does not contain a colorant, the suppression of the degradation of the image quality derived from the joint between the panel units is insufficient.

The colorant is not particularly limited, and examples thereof include dyes and pigments.

The pigment is not particularly limited, and examples thereof include organic pigments, inorganic pigments, minerals and the like of the following numbers described in the color index.

The black pigment is not particularly limited, and examples thereof include carbon black, magnetic materials, iron-titanium composite oxide black, and the like. Among them, the carbon black is not particularly limited, and examples thereof include channel black, furnace black, acetylene black, thermal black, lamp black, and the like. The magnetic material is not particularly limited, and examples thereof include ferrite and magnetite.

The Red or magenta pigment is not particularly limited, and examples thereof include c.i. pigment Red 3, 5, 19, 22, 31, 38, 43, and 48: 1. 48: 2. 48: 3. 48: 4. 48: 5. 49: 1. 53: 1. 57: 1. 57: 2. 58: 4. 63: 1. 81, 81: 1. 81: 2. 81: 3. 81: 4. 88, 104, 108, 112, 122, 123, 144, 146, 149, 166, 168, 169, 170, 177, 178, 179, 184, 185, 208, 216, 226, 257, pigment Violet 3, 19, 23, 29, 30, 37, 50, 88, pigment Orange 13, 16, 20, 36, ruby (chromium containing corundum), garnet, spin (spinel), etc.

The cyan or cyan pigment is not particularly limited, and examples thereof include c.i. pigment Blue1, 15, and 15: 1. 15: 2. 15: 3. 15: 4. 15: 6. 16, 17-1, 22, 27, 28, 29, 36, 60, blue sapphire (iron, titanium containing corundum), and the like.

The Green pigment is not particularly limited, and examples thereof include c.i. pigment Green 7, 26, 36, and 50.

The Yellow pigment is not particularly limited, and examples thereof include c.i.

pigment Yellow

1, 3, 12, 13, 14, 17, 34, 35, 37, 55, 74, 81, 83, 93, 94, 95, 97, 108, 109, 110, 137, 138, 139, 153, 154, 155, 157, 166, 167, 168, 180, 185, 193, and Yellow sapphire (nickel-containing corundum).

The dye is not particularly limited, and conventionally known dyes, for example, dyes described in paragraphs "0057" to "0060" of international publication No. 2015/111351, and the like can be mentioned.

When the base material is a resin, the colorant is preferably a pigment from the viewpoint of having good dispersion stability with respect to the resin, excellent weather resistance, and the like. That is, the light-transmitting layer a according to one embodiment of the present invention preferably further contains a pigment and a resin in addition to the particles described above. Among the pigments, from the viewpoint of further suppressing the change in color of the image and more preferably exhibiting the effects of the present invention, a black pigment is more preferable, and carbon black is even more preferable.

When the colorant is a pigment, the average secondary particle size of the pigment is not particularly limited, but is preferably 0.1 μm or more, and more preferably 0.2 μm or more. Within such a range, the slidability becomes better and the film is less likely to be coagulated, and the nonuniformity of the total light transmittance of the film is further reduced. The average secondary particle size of the pigment is not particularly limited, but is preferably less than 3 μm, and more preferably less than 2.6. Mu.m. When the amount is within this range, scattering unevenness in the film is less likely to occur, the unevenness in the total light transmittance of the film is further reduced, and the haze value is also reduced.

The average secondary particle diameter of the pigment can be determined by directly measuring the size of the secondary particles from an electron micrograph of the layer. Specifically, the particle image was measured by Transmission Electron Micrograph (TEM) (H-7650, hitachi-tech, ltd.) to obtain the average value of the equivalent circle diameters of 100 randomly selected secondary particles, and this value was defined as the average secondary particle diameter.

The colorant may be a commercially available product or a synthetic product. The commercially available product is not particularly limited, and examples thereof include Mitsubishi chemical corporation # 950.

The coloring agent may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The content of the colorant in the light-transmitting layer a is not particularly limited, but is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and still more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the base material. Within such a range, the effect of suppressing the deterioration of the image quality due to the joint between the panel units is further improved. The content of the colorant in the light-transmitting layer a is not particularly limited, but is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 1 part by mass or less, and particularly preferably 0.6 part by mass or less, based on 100 parts by mass of the base material. If the luminance is in such a range, the luminance is further improved.

(other Components)

The light-transmitting layer a according to one embodiment of the present invention may further contain other components than the components described above, as long as the effects of the present invention are not impaired. The other components are not particularly limited, and examples thereof include components used in the field of known optical films and functional layers for known optical applications. Specifically, examples include a retardation adjusting agent, a wavelength dispersion adjusting agent, a plasticizer, an ultraviolet absorber, an antioxidant, a hydrogen-hydrogen bond solvent, an ionic surfactant, and the like, and are not limited to these solvents.

(Total light transmittance)

The light-transmitting layer a according to one embodiment of the present invention has a total light transmittance of 10% to 30%. If the total light transmittance is less than 10%, the luminance becomes insufficient in a display device having a display surface constituted by a plurality of panel units. In addition, if the total light transmittance exceeds 30%, the reduction in image quality resulting from the joints between the panel units in a display device having a display surface constituted by a plurality of panel units is not sufficiently suppressed. From the viewpoint of improving both the effect of suppressing the deterioration of image quality and the brightness derived from the joint between the panel units, the total light transmittance of the light-transmitting layer a is preferably 15% to 25%.

The total light transmittance was measured by using a haze meter (NDH 4000, manufactured by Nippon Denshoku industries Co., ltd.) according to JIS K7361-1: 1997 (test method of total light transmittance of plastic transparent material) was measured.

(surface modification treatment of light-transmitting layer A)

The light-transmitting layer a may be subjected to a surface modification treatment. The method of the surface modification treatment is not particularly limited, and examples thereof include corona discharge treatment, flame treatment, oxidation treatment, and plasma treatment.

(film thickness)

The thickness of the light-transmitting layer A is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, and particularly preferably 8 μm or more. Within such a range, the effect of suppressing the deterioration of the image quality due to the joint between the panel units is further improved in the display device having the display surface constituted by the plurality of panel units. The thickness of the light-transmitting layer A is preferably less than 50 μm, more preferably less than 20 μm, still more preferably 15 μm or less, and particularly preferably 10 μm or less. If the luminance is within such a range, the luminance of the display device having a display surface formed of a plurality of panel units is further improved.

< optical film comprising light-transmitting layer A and substrate layer >

In one embodiment of the present invention, the light-transmitting layer a may be used as a single layer film composed of only the layer, or may constitute a part of the optical film.

The optical film according to one embodiment of the present invention preferably further includes a base material layer as another layer. The base material layer can contribute to protection of the light-transmitting layer a, imparting mechanical properties to the optical film, improving handling suitability of the optical film, and the like. In addition, the base material layer may be a release film that is released at the time of use. As described later, the substrate layer may have a functional layer on one side or both sides.

The base layer is not particularly limited, and is preferably a light-transmitting layer B. The light-transmitting layer B is not particularly limited as long as it can transmit at least a part of incident light. When the total light transmittance of the light-transmitting layer B is within such a range, the luminance of a display device having a display surface formed of a plurality of panel units is further improved when an optical film including the light-transmitting layer a and the light-transmitting layer B as another light-transmitting layer is used. The total light transmittance of the light-transmitting layer B is not particularly limited, but is more preferably 95% or less, still more preferably 93% or less, and particularly preferably 91% or less. When the amount is within this range, the relationship between the haze values of the light-transmitting layer A and the light-transmitting layer B, which will be described later, can be more easily satisfied.

The total light transmittance was measured by using a haze meter (NDH 4000, manufactured by Nippon Denshoku industries Co., ltd.) according to JIS K7361-1: 1997 (test method for total light transmittance of plastic-transparent Material) was measured.

In the optical film according to one embodiment of the present invention, the base layer is preferably ase:Sub>A light-transmitting layer B as another light-transmitting layer, the light-transmitting layer B is disposed on the light-transmitting layer ase:Sub>A, and the light-transmitting layer ase:Sub>A and the light-transmitting layer B satisfy ase:Sub>A relationship of Hz (ase:Sub>A-B) < Hz (B-ase:Sub>A) (%) when light is incident from the side of the light-transmitting layer ase:Sub>A and Hz (B-ase:Sub>A) (%) when light is incident from the side of the light-transmitting layer B, when the haze of ase:Sub>A laminate of one light-transmitting layer ase:Sub>A and one light-transmitting layer B is measured. By satisfying this relationship, the reduction in image quality resulting from the joint between the panel units in a display device having a display surface formed of a plurality of panel units is further suppressed. The reason for this is presumed to be that the light transmitted through the optical film is further scattered by disposing the optical film such that the light-transmitting layer a faces the light-emitting module side and the light-transmitting layer B faces the display surface side (i.e., the viewing side of the display device), but the correctness thereof does not affect the technical scope of the present invention.

The haze value was measured using a haze meter (NDH 4000 manufactured by nippon electrochromism co., ltd.) based on JIS K7136: 2000 the assay was performed.

In the present specification, "the light-transmitting layer B is disposed on the light-transmitting layer a" means not only a configuration in which the light-transmitting layer B is disposed on the surface of the light-transmitting layer a so as to be in contact with the light-transmitting layer a, but also a configuration in which the light-transmitting layer B is disposed on the light-transmitting layer a between the light-transmitting layer a and the light-transmitting layer B via another member. In these configurations, the light-transmitting layer B is preferably disposed on the surface of the light-transmitting layer a so as to be in contact with the light-transmitting layer a.

In one embodiment of the present invention, the number of the base material layer may be 1, 2 or more, and preferably 1. In the case where the optical film has only one base material layer or 2 or more, the light-transmitting layer a preferably constitutes one outermost surface of the optical film.

(base material of base Material layer)

The substrate layer (when the substrate layer has a functional layer described later, a layer or a film which is a base of the substrate layer) preferably contains a base material. In the present specification, when a base layer represented by a light-transmitting layer B or the like described later has a functional layer described later, a layer or a film on which the functional layer is formed is referred to as a "base" or a "foundation".

The content of the matrix material is not particularly limited, and from the viewpoint of light transmittance, the total mass of the base material layer (when the base material layer has a functional layer described later, the base material layer is preferably more than 50% by mass, more preferably more than 80% by mass, and still more preferably more than 90% by mass, based on the total mass of a layer or a film which is a base material of the base material layer). The content of the matrix material is preferably less than 100% by mass with respect to the total mass of the base material layer (in the case where the base material layer has a functional layer described later, a layer or a film which is a base of the base material layer, or the like) from the viewpoint of light absorption and light scattering.

The base material of the base layer (when the base layer has a functional layer described later, a layer or a film which becomes a base of the base layer) is not particularly limited, and the same materials as those listed as the base material of the light-transmitting layer a are exemplified. Among these layers, organic materials are preferable.

The substrate layer (in the case where the substrate layer has a functional layer described later, a layer or a film which becomes a base (i.e., a foundation) of the substrate layer) is preferably a resin layer (e.g., a light-transmitting resin layer) such as a resin film. The resin film means a film containing a resin as a base material. The resin used as the base material may be the same resin as that used as the base material of the light-transmitting layer a. Among these resins, polyester resins are preferable, and polyethylene terephthalate is more preferable, from the viewpoint of haze value.

The base material may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(other Components of the substrate layer)

The substrate layer (a layer or a film which becomes a base of the substrate layer in the case where the substrate layer has a functional layer described later) may further contain other components than the above-described base material as long as the effects of the present invention are not impaired. The other components are not particularly limited, and examples thereof include the particles and the colorant described in the above-mentioned light-transmitting layer a. Examples of the components include those used in the field of known optical films and those used in the field of known functional layers for optical applications. Specific examples include, but are not limited to, particles, colorants, retardation regulators, wavelength dispersion regulators, plasticizers, ultraviolet absorbers, antioxidants, hydrogen bonding solvents, ionic surfactants, and the like.

(surface modification treatment of substrate layer)

The substrate layer may be subjected to a surface modification treatment. The method of the surface modification treatment is not particularly limited, and examples thereof include corona discharge treatment, flame treatment, oxidation treatment, and plasma treatment.

(functional layer of substrate layer)

The base material layer may have a functional layer on one side or both sides of a layer or a film to be a base material. More specifically, the base layer may have a functional layer on the side of the light-transmitting layer a (i.e., between the light-transmitting layer a and a layer or film which is a base material of the base layer) or on the side opposite to the light-transmitting layer a.

In the present specification, when the substrate layer has a functional layer, the substrate layer is regarded as including the functional layer. Thus, for example, when the light-transmitting layer B has a functional layer, the layer B is regarded as the light-transmitting layer B including the functional layer.

The functional layer of the base layer is not particularly limited, and examples thereof include functional layers used for optical applications. Specific examples thereof include, but are not limited to, a release layer, an easy-adhesion layer, an antistatic layer, a hard coat layer, an antireflection layer, an antiglare layer, an interlayer layer, a buffer layer, and an easy-slip layer. Among these layers, an easy-adhesion layer or a hard coat layer is preferable, and an easy-adhesion layer is more preferable.

The easy-adhesion layer is not particularly limited, and a known easy-adhesion layer can be suitably used.

In the optical film according to one embodiment of the present invention, the easy-adhesion layer is preferably provided only on one surface or both surfaces of a layer or a film which is a base (base) of the light-transmitting layer B. In these embodiments, it is more preferable that at least an easy-adhesion layer is provided on the surface of the light-transmitting layer a side of a layer or film which is a base (base) of the light-transmitting layer B.

The hard coat layer is not particularly limited, and examples thereof include a cured layer containing a resin containing an alicyclic hydrocarbon and fine particles coated with a polymeric silane coupling agent. In the case where the hard coat layer is provided, a buffer layer is preferably further provided between the hard coat layer and the film. The buffer layer is not particularly limited, and examples thereof include a layer containing a resin different from the resin contained in the hard coat layer and fine particles coated with a polymeric silane coupling agent.

In the optical film according to one embodiment of the present invention, the hard coat layer is preferably provided only on one surface side or both surface sides of a layer or a film which is a base material (base) of the light-transmitting layer B. Of these films, at least the hard coat layer is more preferably provided on the surface side opposite to the light-transmitting layer a, such as a layer or a film that is a base material (base) of the light-transmitting layer B. Further, it is more preferable to provide a hard coat layer only on the surface side of the layer or film, which is the base material (base) of the light-transmissive layer B, on the side opposite to the light-transmissive layer a.

The base material layer may have only 1 functional layer on one side or both sides, or may have 2 or more layers stacked.

The film thickness of the functional layer of the base layer is not particularly limited, but is preferably less than 10 μm, more preferably less than 8 μm, still more preferably less than 5 μm, and particularly preferably less than 3 μm (the lower limit exceeds 0 μm).

(film thickness of substrate layer)

The thickness of the base layer is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, further preferably 30 μm or more, and particularly preferably 50 μm or more. When the amount is within such a range, the protective effect of the light-transmitting layer a, the effect of imparting mechanical properties to the optical film, the handling suitability of the optical film, and the like are further improved. In addition, in the case where the base layer is the light-transmitting layer B, in the display device having the display surface constituted by the plurality of panel units, the deterioration of the image quality derived from the joint between the respective panel units is further suppressed. The thickness of the base material layer is preferably 500 μm or less, more preferably 200 μm or less, still more preferably 100 μm or less, and particularly preferably 80 μm or less. If the thickness is within this range, the luminance of a display device having a display surface formed of a plurality of panel units is further improved when the base layer is a light-transmitting layer.

In one embodiment of the present invention, the film thickness of the light-transmitting layer a is preferably smaller than the film thickness of the base material layer.

(examples of the substrate layer)

As the substrate layer, commercially available products can be used. The commercially available product is not particularly limited, and when the base layer is the light-transmitting layer B, examples thereof include Zeonor (registered trademark) ZF16 manufactured by Zeon corporation, japan, and COSMO SHINE (registered trademark) a4300 manufactured by toyobo co.

< other functional layers >

The optical film according to one embodiment of the present invention may further include a light-transmitting layer a and a functional layer other than the base material layer, that is, another functional layer other than the functional layer of the base material layer. For example, in the optical film according to one embodiment of the present invention, the light-transmissive layer a may further have another functional layer on one side or both sides thereof as necessary. The details of the other functional layer are also the same as those of the functional layer of the base layer described above.

In the optical film according to one embodiment of the present invention, when the light-transmitting layer a has another functional layer on one side or both sides thereof, the total light transmittance of the laminate of the light-transmitting layer a and the other functional layer provided on one side or both sides of the light-transmitting layer a is preferably 10% to 30%, and more preferably 15% to 25%. The total light transmittance was measured by using a haze meter (NDH 4000, manufactured by Nippon Denshoku industries Co., ltd.) based on JIS K7361-1: 1997 (test method of total light transmittance of plastic-transparent Material) was measured.

In the optical film according to one embodiment of the present invention, when the haze of ase:Sub>A laminate of one light-transmissive layer ase:Sub>A, one light-transmissive layer B, and other functional layers provided on one side or both sides of the light-transmissive layer ase:Sub>A is measured in the case where the light-transmissive layer ase:Sub>A has the other functional layer on one side or both sides thereof, it is preferable that the relationship between the value Hz (ase:Sub>A-B) < Hz (B-ase:Sub>A) is satisfied between the value Hz (ase:Sub>A-B) (%) when light is incident from the light-transmissive layer ase:Sub>A side and the value Hz (B-ase:Sub>A) (%) when light is incident from the light-transmissive layer B side. The haze value was measured using a haze meter (NDH 4000, manufactured by nippon electrochromism co., ltd.) based on JIS K7136: 2000 the assay was carried out.

< example of Membrane formation >

Fig. 1 (a) to (C) show examples of the structure of the film used in one embodiment of the present invention. Fig. 1 (a) shows a single-layer film composed only of the light-transmitting layer A1. Fig. 1 (B) shows a laminated film 2 in which a light-transmissive layer A1 and a light-transmissive layer B3 are laminated. In fig. 1 (B), the light-transmitting layer A1 constitutes one outermost surface, the light-transmitting layer B3 constitutes the other outermost surface, and the light-transmitting layer B3 is disposed on the surface of the light-transmitting layer A1 so as to be in contact with the light-transmitting layer A1. For example, the light-transmitting layer B preferably has an easy-adhesion layer (not shown), and the light-transmitting layer B3 having the easy-adhesion layer (not shown) is preferably disposed on the surface of the light-transmitting layer A1 so as to be in contact with the light-transmitting layer A1. Fig. 1 (C) shows a laminated film 2 in which a light-transmitting layer A1 and a light-transmitting layer B3 are laminated, and further, the light-transmitting layer B3 constitutes a thin film of a hard coat layer 4 having a surface opposite to the side of the light-transmitting layer A1. In fig. 1C, one of the outermost surface examples constitutes a light-transmitting layer A1, and a light-transmitting layer B3 is disposed on the surface of the light-transmitting layer A1 so as to be in contact with the light-transmitting layer A1. For example, it is also preferable that the light-transmitting layer B has an easy-adhesion layer (not shown), and the light-transmitting layer B3 having an easy-adhesion layer (not shown) is disposed on the surface of the light-transmitting layer A1 so as to be in contact with the light-transmitting layer A1. Further, for example, it is also preferable to form the hard coat layer 4 on an easy adhesion layer (not shown) of the light transmitting layer B3 having the easy adhesion layer (not shown). In fig. 1 (C), 3' represents a layer or film which serves as a base (base) of the light-transmitting layer B3.

< method for producing film >

The method for producing the optical film according to one embodiment of the present invention is not particularly limited, and a known method for producing a film may be used. Examples thereof include a coating method, a solution casting method, a melt casting method, and a vapor phase film formation method. Among these films, a method comprising the following steps is preferred: the method comprises 1) a coating liquid preparation step for obtaining a coating liquid for forming the light-transmitting layer A, 2) a coating film formation step for applying the obtained coating liquid for forming the light-transmitting layer A to the surface of the support, and 3) a drying step for removing the solvent from the coating film of the applied coating liquid for forming the light-transmitting layer A to form the light-transmitting layer A.

Here, when the support is a base material layer (for example, the light-transmitting layer B), a laminated film including the light-transmitting layer a and the base material layer can be produced by this production method.

1) Coating liquid preparation step

In this step, a coating liquid for forming the light-transmitting layer a, which contains the particles described in the light-transmitting layer a, the colorant described in the light-transmitting layer a, and the solvent, is prepared. The coating liquid for forming the light-transmitting layer a may further contain a base material (e.g., a resin) or other components as necessary.

The coating liquid for forming the light-transmitting layer a is preferably prepared by preparing a particle dispersion liquid and a colorant dispersion liquid or a colorant solution, and mixing these dispersion liquid or solution, a solvent, and if necessary, a base material with other components if necessary. The preparation of the particle dispersion and the colorant dispersion or colorant solution are not particularly limited, and the following layers exemplified as the solvent of the coating liquid for forming the light-transmissive layer a are preferably used. In addition, it is preferable to perform filtration in the preparation of the particle dispersion liquid and the preparation of the colorant dispersion liquid or the colorant solution. For filtration, a known filtration device can be suitably used.

The solvent used in the coating liquid for forming the light-transmitting layer a is not particularly limited, and examples thereof include chlorine-based solvents such as chloroform and methylene chloride, alcohols such as methanol, ethanol, propanol, n-butanol, 2-butanol, t-butanol and cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone and acetone, esters such as ethyl acetate, methyl acetate, ethyl lactate, isopropyl acetate, amyl acetate and ethyl butyrate, glycol ethers (propylene glycol mono (C1 to C4) alkyl ethers (specifically, propylene Glycol Monomethyl Ether (PGME), propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-isopropyl ether and propylene glycol monobutyl ether), propylene glycol mono (C1 to C4) alkyl ether esters (propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate)), hydrocarbons such as toluene, benzene, cyclohexane and n-hexane. Among these, chlorine-based solvents, alcohols, and ketones are preferably contained, and chlorine-based solvents are more preferably contained, from the viewpoint of easy dissolution of the base material, low boiling point, and easy improvement of the drying rate and productivity.

In addition, from the viewpoint of easy formation of the light-transmitting layer a having high planarity, it is preferable to include a chlorine-based solvent, an alcohol, and a ketone. The chlorine-based solvent is preferably dichloromethane. The alcohol is preferably methanol or ethanol, and more preferably ethanol. The ketone is preferably methyl ethyl ketone or acetone, and more preferably methyl ethyl ketone. That is, it is particularly preferable to contain at least one of dichloromethane, ethanol, and methyl ethyl ketone.

When the solvent includes a chlorine-based solvent and another solvent, the content ratio of the chlorine-based solvent is not particularly limited, but from the viewpoint of achieving both drying speed and planarity, the ratio of chlorine-based solvent/other solvent = less than 100/more than 0 to 60/40 (mass ratio), more preferably 99.9/0.1 to 90/10 (mass ratio), and still more preferably 99.5/0.5 to 99/1 (mass ratio). If the proportion of the chlorine-containing solvent is appropriately large, the drying property and productivity are easily improved.

The concentration of the base material in the coating liquid for forming the light-transmitting layer a is preferably 1 to 20% by mass from the viewpoint of easily adjusting the viscosity to an appropriate range. From the viewpoint of reducing the amount of shrinkage of the coating film during drying, the concentration of the base material in the coating liquid for forming the light-transmissive layer a is more preferably more than 5% by mass and 20% by mass or less, and still more preferably more than 5% by mass and 15% by mass or less.

In the preparation of the coating liquid for forming the light-transmitting layer a, the preparation of the particle dispersion, and the preparation of various dispersions or solutions such as the colorant dispersion or the colorant solution, the mixing conditions are not particularly limited. The mixing temperature may be at room temperature, and the mixing may be performed while heating to improve the solubility. The mixing time is not particularly limited, but when the matrix is mixed, it is preferable to set the time to completely dissolve the matrix. In addition, a known mixing device can be suitably used for mixing.

The viscosity of the coating liquid for forming the light-transmitting layer a is not particularly limited, and is preferably 5 to 5000mPa · s. When the viscosity of the coating liquid for forming the light-transmitting layer A is 5 mPas or more, a layer having an appropriate thickness can be more easily formed. Further, if the viscosity of the coating liquid for forming the light-transmitting layer a is 5000mPa · s or less, the occurrence of thickness unevenness due to an increase in the viscosity of the solution can be further suppressed. From the same viewpoint, the viscosity of the coating liquid for forming the light-transmitting layer a is more preferably 100 to 1000mPa · s. The viscosity can be measured at 25 ℃ by means of an E-type viscometer.

2) Coating film forming step

In this step, the obtained coating liquid for forming the light-transmissive layer a is applied to the surface of the support. Specifically, the obtained coating liquid for forming the light-transmitting layer a was applied to the surface of the support.

The method of applying the coating liquid for forming the light-transmitting layer a is not particularly limited, and a known coating method can be used. Examples thereof include a back coating method, a gravure coating method, a spin coating method, a wire bar coating method, and a roll coating method. Among these coating methods, the back coating method is preferable in terms of forming a thin and uniform coating film.

In the case of producing a laminated film, as described above, the base material layer is preferably used as the support. The details of the base material layer are as described above. In the case of using a base material layer as the support, the base material layer has a functional layer (for example, an easy-adhesion layer) and the coating liquid for forming the light-transmissive layer a is preferably applied to the surface on which the functional layer is formed.

3) Drying step

In this step, the solvent is removed from the coating film of the coating liquid for forming the light-transmissive layer a applied to the support to form the light-transmissive layer a. Specifically, the coating film of the coating liquid for forming the light-transmissive layer a provided on the support is dried.

The method of applying the coating liquid for forming the light-transmitting layer a is not particularly limited, and a known drying method can be used. Examples thereof include a method using air blowing or heating. Among these coating methods, a method using air blowing is preferred from the viewpoint of easy suppression of curling and the like.

The drying rate of the coating film is not particularly limited, but is preferably 0.0015 to 0.05kg/hr · m ² More preferably 0.002 to 0.05kg/hr · m ² . The drying rate is expressed as the mass of the solvent evaporated per unit time and per unit area. The drying rate can generally be adjusted by means of the drying temperature. The drying temperature is not particularly limited, but it is preferably (Tb-50) to (Tb + 50) ° C, and for example, preferably 50 to 200 ℃.

For example, after this step, the light-transmissive layer a is peeled from the support, whereby a single-layer film composed only of the light-transmissive layer a can be obtained.

In addition, for example, in the case of using a base material layer as the support, the formation of the base material layer after this step results in the formation of a laminated film including the light-transmissive layer a and the base material layer. In this case, the light-transmitting layer a can be used as a laminate film without being peeled from the base material layer. In particular, when the base layer is the light-transmitting layer B composed of only the above-described base layer or film, or when the light-transmitting layer B has a functional layer (for example, an easy-adhesion layer), the light-transmitting layer a may be used as an optical film without being peeled off.

4) Winding step

The optical film of one embodiment of the present invention may be a tape. Therefore, the method for producing an optical film may further include 4) a winding step of winding the optical film in a strip shape into a roll-like object.

In this step, the obtained band-shaped light-transmitting layer a, a laminate of the light-transmitting layer a and a base material layer, or if necessary, a structure in which other functional layers are formed, is wound in a roll shape in a direction orthogonal to the width direction thereof, and is formed into a roll shape.

The length of the optical film in a tape form is not particularly limited, and is preferably, for example, about 100 to 10000 m. The width of the optical film in a band shape is preferably 1m or more, and more preferably 1.3 to 4m.

< apparatus for producing film >

The optical film according to one embodiment of the present invention is not particularly limited, and may be manufactured by, for example, a manufacturing apparatus shown in fig. 2.

Fig. 2 is a schematic view of a manufacturing apparatus 200 for manufacturing an optical film according to an embodiment of the present invention. The manufacturing apparatus 200 includes a supply unit 210, a coating unit 220, a drying unit 230, a cooling unit 240, and a winding unit 250.a to d represent transport rollers for transporting the support body 110.

The supply unit 210 includes a feeding device (not shown) for feeding out the roll 201 of the band-shaped support body 110 wound around the winding core.

The coating section 220 is a coating device, and includes a support roller 221 for holding the support 110, a coating head 222 for coating the support 110 held by the support roller 221 with a coating liquid for forming the transparent layer a, and a decompression chamber 223 provided on the upstream side of the coating head 222.

The flow rate of the coating liquid for forming the transparent layer a discharged from the coating head 222 can be adjusted by a pump not shown. The flow rate of the coating liquid for forming the transparent layer a discharged from the coating head 222 is set to an amount that enables a coating layer having a predetermined film thickness to be stably formed when coating is continuously performed under the conditions of the coating head 222 adjusted in advance.

The decompression chamber 223 is a mechanism for stabilizing a liquid bead (accumulation of the coating liquid) formed between the coating liquid for forming the transparent layer a from the coating head 222 and the support 110 at the time of coating, and the degree of decompression can be adjusted. The decompression chamber 223 is connected to a decompression blower (not shown) to decompress the inside. The decompression chamber 223 is in a state where no air leaks, and the gap with the backup roller is also adjusted to be narrow, so that a stable bead of the coating liquid can be formed.

The drying unit 230 is a drying device that dries a coating film applied to the surface of the support body 110, and includes a drying chamber 231, an inlet 232 for a drying gas, and an outlet 233. The temperature and the air volume of the drying air are appropriately determined depending on the type of the coating film and the type of the support 110. The amount of the residual solvent in the dried coating film can be adjusted by setting conditions such as the temperature, the air volume, and the drying time of the drying air in the drying section 230. The residual solvent content of the dried coating film can be measured by comparing the unit mass of the dried coating film with the mass of the coating film after the coating film is sufficiently dried.

The cooling section 240 cools the support 110 having the coating film (light-transmitting layer a (not shown)) dried by the drying section 230, and adjusts the temperature to an appropriate temperature. Cooling unit 240 has cooling chamber 241, cooling air inlet 242, and cooling air outlet 243. The temperature and the volume of the cooling air can be appropriately determined depending on the type of the coating film and the type of the support 110. Even if the cooling unit 240 is not provided, the cooling unit 240 may be omitted when the cooling temperature is appropriate.

The winding section 250 is a winding device (not shown) for winding the support 110 (laminate 100) on which the light-transmissive layer a (not shown) is formed to obtain the roll 251.

In the case of producing a laminated film, as described above, a base layer is preferably used as the support 110 (for example, the light-transmitting layer B). In this case, the laminate 100 of the light-transmissive layer a and the support becomes a laminated film.

< use >)

An optical film according to one embodiment of the present invention is used for a display device having a display surface constituted by a plurality of panel units. The optical film according to one embodiment of the present invention is not particularly limited, and can be preferably applied to, for example, a panel unit and a unit listed in the following detailed description of a display device.

(Panel unit and display device)

The panel unit to which the above optical film is applied and the display device including the panel unit are not particularly limited, and a self-luminous type panel unit and a display device having a display surface constituted by the same are preferable.

In one embodiment of the present invention, the optical film is more preferably used for a display device having a display surface constituted by a panel unit having a light-emitting module. That is, another embodiment of the present invention is also referred to as a panel unit, and is used for a display device having a display surface formed of a plurality of panel units, which includes a light-emitting module and the above-described optical film disposed on the display surface side (i.e., the visual recognition side in the display device) of the light-emitting module.

In one embodiment of the present invention, when the optical film includes the light-transmissive layer a and the base layer (preferably, the light-transmissive layer B), the base layer (preferably, the light-transmissive layer B) is disposed on the display surface side of the light-transmissive layer a, and the optical film is more preferably used for a display device having a display surface constituted by a panel unit having a light-emitting module. That is, another embodiment of the present invention is also referred to as a panel unit, and is used for a display device having a display surface constituted by a plurality of panel units each including a light-emitting module and the above-described optical film disposed on the display surface side of the light-emitting module, and the above-described base layer (preferably, the light-transmissive layer B) disposed on the display surface side of the light-transmissive layer a. In this case, the light-transmitting layer a preferably constitutes one outermost surface example of the optical film, and the light-emitting module and the surface of the optical film on the light-transmitting layer a side are preferably arranged to face each other.

In one embodiment of the present invention, the panel unit is not particularly limited, and for example, a panel unit having a known light emitting module may be used. Among these units, a light-emitting module is preferable in which a large number of minute light-emitting elements are mounted in a matrix on a wiring board, and each light-emitting element is selectively caused to emit light by a light-emission control mechanism connected thereto, whereby visual information can be directly displayed on a display screen by blinking of each light-emitting element. Further, the light-emitting element included in the light-emitting module is more preferably an LED element. That is, the light emitting module is more preferably an LED module in which the light emitting element is an LED element.

When the panel unit includes the light emitting module and the optical film, the light emitting module and the optical film are preferably bonded together with an adhesive. When the laminate film is preferably laminated, the base layer (preferably, the light-transmitting layer B) is disposed on the display surface side of the light-transmitting layer a. Further, the light-emitting module and the outermost surface of the laminate film closer to the light-transmitting layer a than the base layer (preferably, the light-transmitting layer B) are preferably bonded together with an adhesive. In this case, the light-transmitting layer a preferably constitutes one outermost surface example of the optical film, and the surface of the optical film on the light-transmitting layer a side and the light-emitting module are preferably bonded so as to face each other. The adhesive is not particularly limited, and known adhesives can be used, and examples thereof include pressure-sensitive adhesives, thermosetting adhesives, and photocurable adhesives. Among these adhesives, pressure-sensitive adhesives are preferable. The pressure-sensitive adhesive is not particularly limited, and examples thereof include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, silicone pressure-sensitive adhesives, urethane pressure-sensitive adhesives, and polyacrylic amide pressure-sensitive adhesives. In these cases, the panel unit has the light emitting module, the above optical film, and an adhesive layer disposed therebetween.

In addition, when the panel unit includes the light emitting module and the optical film, the light emitting module, the optical film, and other members used as necessary may be integrated and bonded by hot press working. In the case of laminating a laminated film, the substrate layer (preferably, the light-transmitting layer B) is disposed on the display surface side of the light-transmitting layer a, and the light-emitting module is preferably laminated on the outermost surface of the laminated film on the light-transmitting layer a side of the substrate layer (preferably, the light-transmitting layer B). In this case, the light-transmitting layer a constitutes one outermost surface example of the optical film, and the surface of the optical film on the light-transmitting layer a side and the light-emitting module are preferably bonded so as to face each other. In the case of bonding by integration by hot stamping, the above adhesive may be applied between arbitrary members.

Hereinafter, an example of a configuration of an LED module, which is one of light emitting modules, will be described, but the LED module that can be used in the present invention is not limited to this configuration.

The LED module is configured by mounting one or more LED elements on a wiring substrate having a wiring portion formed on a support substrate. Here, the LED module is preferably configured by mounting a plurality of LED elements.

The wiring board is a circuit board in which a wiring portion formed of a metal such as copper or another conductive member is formed on a surface of a support substrate so as to be electrically conductive to the LED element. The material of the support substrate is not particularly limited, and examples thereof include conventionally known materials used as substrates of electronic circuits, for example, glass epoxy resins and the like.

In the LED module, the LED element is mounted on the wiring portion in an electrically conductive manner via the adhesive layer.

The LED elements are independently controlled to emit light by a light emission control mechanism such as an IC chip substrate separately bonded thereto.

The size of the LED module is not particularly limited, but generally, from the viewpoint of cost effectiveness, the length of the diagonal line is preferably about 10 inches to 200 inches, and more preferably about 50 inches to 200 inches.

The LED element mounted on the wiring board is not particularly limited, and is preferably a light-emitting element that emits light at a PN junction formed by bonding a P-type semiconductor and an N-type semiconductor. The structure of such a light-emitting element is not particularly limited, and examples thereof include a structure in which a P-type electrode and an N-type electrode are provided on the upper surface and the lower surface of the element, and a structure in which both a P-type electrode and an N-type electrode are provided on one surface of the element. In particular, a very small-sized LED element such as the LED element disclosed as "chip-like electronic component" in japanese patent application laid-open No. 2006-339551 is preferably used. The LED element disclosed in this document has a size of approximately 25 μm × 15 μm × 2.5 μm in width × depth × height.

The LED element preferably includes an LED light emitting chip and a cover covering the chip. The material of the resin cover is not particularly limited, and examples thereof include organic insulating materials such as epoxy resin, silicone resin, and polyimide resin. Among these elements, an epoxy resin is preferable from the viewpoint of protecting the LED light emitting chip from physical impact, suppressing total reflection of light into the semiconductor due to a difference in refractive index between the semiconductor constituting the LED light emitting chip and air, and improving the light emission efficiency of the LED element.

The LED element is more preferably a "micro-sized LED element". In the present specification, the term "micro-sized LED element" specifically means an LED element having a width (W) and a depth (D) of 300 μm or less and a height (H) of 200 μm or less, with respect to the size of the entire light-emitting element including an LED light-emitting chip and a resin cover covering the chip. Further, the "micro-sized LED element" is more preferably 50 μm or less in width and depth and 10 μm or less in height. The interval between the LED elements is preferably 0.03mm to 100mm, more preferably 0.05mm to 5mm. Further, the light emitting module (LED module) in which the light emitting elements are LED elements has a width and a depth of 50 μm or less, and the LED elements having a minute size of 10 μm or less in height are particularly preferably arranged in a matrix of several thousands × several thousands or more at a pitch of several μm to several tens of μm. In the present specification, a display device having a display surface including a panel unit including the above-described LED modules in which "Micro-sized LED elements" are arranged in a matrix at an arrangement interval of 0.03mm to 100mm is referred to as a "Micro-LED display device".

Fig. 3 is a schematic diagram showing a cross-sectional structure of a panel unit according to an embodiment of the present invention. The upper side of fig. 3 is the display surface side (i.e., the visual recognition side of the display device). The panel unit 10 has an LED module 11 and a laminated film 2 having a hard coat layer 4. The laminate film 2 is disposed on the display surface side of the light-emitting module 11, and the light-transmissive layer B3 is disposed on the display surface side of the light-transmissive layer A1. At this time, the LED module 11 and the surface of the laminate film 2 on the side of the light-transmitting layer A1 are bonded via the adhesive layer 12. In fig. 3, 3' represents a layer or film which serves as a base (base) of the light-transmitting layer B3.

The display device represents visual information such as characters, images, and moving pictures. The display device to which the above optical film is applied is not particularly limited, and known devices can be used, and examples thereof include non-light-emitting devices such as liquid crystal display devices, and self-light-emitting devices such as LED display devices and organic EL display devices. Among these devices, a self-light emitting device is preferable, and an LED display device is more preferable, and the above-mentioned Micro-LED display device is preferable.

Each panel unit having the light emitting module is preferably used for a display device having a display surface constituted by a plurality of panel units. That is, another aspect of the present invention relates to a display device having a display surface constituted by a plurality of types of panel units including the above optical film.

In this specification, a display device having a display surface formed of a plurality of panel units is referred to as an independent module type display device. In the independent module type display device, a plurality of panel units may be laid in a curved surface shape, or may be laid in a tile shape (matrix shape, planar shape). Among them, it is preferably laid in a tile shape. In addition, the display surfaces of the plurality of panel units may constitute independent visual information, and the display surfaces may constitute one piece of visual information as a whole. Of these, it is preferable that each display surface constitutes one visual information as a whole.

Fig. 4 is a schematic view showing a planar structure of a display device of a standalone module type according to an embodiment of the present invention. The display surface of the independent module type display device 20 has a display surface in which a plurality of panel units 10 are laid in a tile shape (planar shape). In addition, the display device having a display surface constituted by a plurality of panel units is preferably capable of being decomposed into display devices having a display surface constituted by one or a plurality of panel units included therein.

As the light emitting module and the display device, for example, a known module and device described in japanese patent application laid-open No. 2019-204905 and the like can be used.

Examples

The effects of the present invention will be described with reference to the following examples and comparative examples. However, the scope of the technique of the present invention is not limited to the following examples.

< production of film >

[ film 1 (laminated film) ]

(preparation of particle Dispersion)

10 parts by mass of silica particles (R972V, manufactured by AEROSIL corporation, japan) and 90 parts by mass of ethanol were stirred and mixed for 30 minutes by a dissolver, and then dispersed by using Manton Gorlin as a high-pressure disperser to prepare a dispersion liquid. To the obtained dispersion, 65 parts by mass of methylene chloride was added with stirring, and the mixture was stirred and mixed by a dissolver for 30 minutes to dilute the mixture. The resulting solution was filtered through a polypropylene wound cartridge filter TCW-PPS-1N manufactured by ADVANTECH Toyo K.K., to obtain a particle dispersion.

(preparation of pigment Dispersion)

10 parts by mass of Carbon Black (CB) (model #950 manufactured by Mitsubishi chemical corporation) and 90 parts by mass of Methyl Ethyl Ketone (MEK) were stirred and mixed by a dissolver for 30 minutes, and then dispersed by an ultrasonic disperser for 30 minutes to prepare a dispersion liquid. The obtained dispersion was filtered through a polypropylene wound-roll filter TCW-PPS-1N manufactured by ADVANTECH Toyo K.K., to obtain a pigment dispersion.

(preparation of coating liquid for Forming light-transmitting layer A)

First, dichloromethane was added to a pressurized dissolution tank. Next, a cycloolefin resin (COP, weight average molecular weight 14 ten thousand, cycloolefin resin having a polar group (carboxyl group) manufactured by JSR corporation ARTON (registered trademark) G7810) was charged while stirring. Next, the particle dispersion and the pigment dispersion prepared above were put in, heated to 60 ℃, and stirred for 30 minutes to completely dissolve the cycloolefin resin, thereby obtaining a coating liquid for forming the light-transmitting layer a.

Composition of coating liquid for Forming light-transmitting layer A

(production of a multilayer film comprising a light-transmitting layer A and a light-transmitting layer B)

As the light-transmitting layer B, zeonor (registered trademark) ZF16 (thickness 100 μm manufactured by Zeon corporation, japan) was prepared. On the light-transmitting layer B, the coating liquid for forming the light-transmitting layer a obtained above was applied by a back coating method using a die. Then, the drying speed was set to 0.002kg/hr · m ² The hot air blown from the side of the light-transmitting layer B and the hot air blown from the side of the coating film of the coating liquid for forming the light-transmitting layer A were dried at a temperature of 130 ℃ to form the light-transmitting layer A having a thickness of 10 μm, thereby obtaining a film 1 as a laminated film. The average secondary particle size of the silica particles in the light-transmitting layer a was 200nm, and the average secondary particle size of the pigment was 300nm.

[ film 2 (laminated film) ]

In the production of the film 1, a film 2 was obtained as a laminated film in the same manner as above except that the light-transmitting layer B was changed to a polyethylene terephthalate film (PET film) (COSMOSHINE (registered trademark) a4300, manufactured by toyobo co., ltd., thickness 50 μm).

[ film 3 (laminated film) ]

A film 3 as a laminated film was obtained in the same manner as in the production of the film 1 except that the amount of carbon black added to the light-transmitting layer a was changed so that the amount of the pigment dispersion was 0.55 parts by mass with respect to 100 parts by mass of the cycloolefin resin.

[ film 4 (laminated film) ]

In the production of the film 1, a film 4 as a laminated film was obtained in the same manner except that the amount of carbon black added to the light-transmitting layer a was changed to 0.55 parts by mass of the pigment dispersion liquid with respect to 100 parts by mass of the cycloolefin resin, and the light-transmitting layer B was changed to a polyethylene terephthalate film (PET film) (COSMOSHINE (registered trademark) a4300, thickness 50 μm, manufactured by toyobo co.

[ film 5 (laminated film) ]

In the production of the film 1, a film 5 was obtained as a laminated film in the same manner except that the amount of carbon black added to the light-transmitting layer a was changed to 0.50 parts by mass of the pigment dispersion liquid with respect to 100 parts by mass of the cycloolefin resin, and the light-transmitting layer B was changed to a polyethylene terephthalate film (PET film) (COSMOSHINE (registered trademark) a4300, thickness 50 μm, manufactured by toyobo co).

[ film 6 (laminated film) ]

A film 6 as a laminated film was obtained in the same manner as in the production of the film 1 except that the amount of carbon black added to the light-transmitting layer a was changed so as to be 0.50 parts by mass relative to 100 parts by mass of the cycloolefin resin.

[ film 7 (Single-layer film) ]

A laminated film including the light-transmitting layer a and the light-transmitting layer B was obtained in the same manner as in the production of the film 1, except that the amount of carbon black added to the light-transmitting layer a was changed to 0.55 parts by mass relative to 100 parts by mass of the cycloolefin resin. Next, the light-transmitting layer B was peeled from the obtained laminated film to obtain only the light-transmitting layer a, thereby obtaining a film 7 as a single-layer film.

[ film 8 (laminated film) ]

In the production of the film 1, a film 8 was obtained as a laminated film in the same manner as above except that the particle dispersion was not added at the time of producing the light-transmitting layer a, the amount of carbon black added to the light-transmitting layer a was changed to 0.55 parts by mass of the pigment dispersion with respect to 100 parts by mass of the cycloolefin resin, and the light-transmitting layer B was changed to a polyethylene terephthalate film (PET film) (COSMOSHINE (registered trademark) a4300, thickness 50 μm, manufactured by toyobo co).

[ film 9 (Single-layer film) ]

A laminated film including the light-transmitting layer a and the light-transmitting layer B was obtained in the same manner as in the production of the film 1 except that the amount of the pigment dispersion was changed so that the amount of the carbon black added to the light-transmitting layer a was 0.55 parts by mass relative to 100 parts by mass of the cycloolefin resin without adding the particle dispersion at the time of producing the light-transmitting layer a. Next, the light-transmitting layer B was peeled from the obtained laminated film to form only the light-transmitting layer a, thereby obtaining a film 9 as a single-layer film.

[ film 10 (laminated film) ]

A film 10 as a laminated film was obtained in the same manner as in the production of the film 1 except that the amount of carbon black added to the light-transmitting layer a was changed to 0.65 parts by mass relative to 100 parts by mass of the cycloolefin resin.

[ film 11 (laminated film) ]

A film 11 as a laminated film was obtained in the same manner as in the production of the film 1 except that the pigment dispersion was not added at the time of producing the light-transmitting layer a.

In the films 2 to 11, the thickness of the light-transmitting layer a was 10 μm in all cases. In the films 2 to 11, the average secondary particle size of the silica particles in the light-transmitting layer a was all 200nm except for the films 8 and 9 containing no silica particles. In the films 2 to 11, the average secondary particle size of the pigment was 300nm in all cases except for the film 11 containing no pigment.

The characteristics of each film are shown in table 1 below.

< evaluation of film >

[ Total light transmittance of the light-transmitting layer A and the light-transmitting layer B ]

With respect to the films 1 to 6, 8, 10 and 11 as laminated films, the light-transmitting layer B was peeled off and the films 7 and 9 as single-layer films were evaluated for total light transmittance (%) in the state of only the light-transmitting layer a (i.e., in the state of only the light-transmitting layer a). These results are shown in table 1 below.

Further, zeonor (registered trademark) ZF16 manufactured by Zeon corporation, japan and COSMOSHINE (registered trademark) a4300 manufactured by toyobo co., ltd. was used as the light-transmitting layer B, and the total light transmittance was measured by the same method, and then was 91.90% and 90.41%, respectively.

The total light transmittance was measured by using a haze meter (NDH 4000, manufactured by japan electro-color industries, ltd.) based on JIS K7361-1: 1997 (test method of total light transmittance of plastic-transparent Material) was measured.

[ haze of laminated film ]

For the films 1 to 6, 8, 10, and 11 as the laminated films, the haze value Hz (ase:Sub>A-B) (%) measured from the side of the light-transmissive layer ase:Sub>A and the haze value Hz (B-ase:Sub>A) (%) measured from the side of the light-transmissive layer B were evaluated. The haze value was measured using a haze meter (NDH 4000, manufactured by nippon electrochromism co., ltd.) based on JIS K7136: 2000 the assay was carried out. The larger value of Hz (A-B) (%) and Hz (B-A) (%) is shown in Table 1 below.

< evaluation of display device >

[ manufacture of Panel Unit and display device ]

An adhesive layer made of a pressure-sensitive adhesive is bonded to the surface of an LED element including a resin cover of an LED module including LED elements having an outer shape of 40cm in the vertical direction and 40cm in the horizontal direction and having a pitch of 2mm in the vertical and horizontal directions. Next, the obtained film was bonded to the surface of the LED element of the LED module via the adhesive layer, thereby obtaining a panel unit. Here, in the case where the film is a laminated film, the laminated film is bonded so that the light-transmitting layer a side of the laminated film and the surface of the LED element are arranged to face each other. Then, the obtained panel units were connected in parallel in the lateral direction by 2 pieces to obtain an independent module type display device.

[ Brightness and seamless Property of display device ]

The luminance (cd/m) of the independent module type display device obtained as described above was measured using ProMetric Color 1600 manufactured by CYBERNET SYSTEMS K.K ² ) The average luminance value and the luminance uniformity of the panel cells were evaluated. Here, the higher the seamless property between panels of the luminance uniformity, the smaller the value. Thus, the luminance uniformity may be an index of an effect of suppressing a decrease in image quality from a joint between panel units in a display device having a display surface constituted by a plurality of panel units. The luminance average value and the luminance uniformity can be calculated using the following expressions, respectively. In the following formula, the average uniformity is represented as Lu, and the average luminance is represented as La.

The luminance average value of the independent module type display manufactured in the same manner as described above was 3000cd/m, except that the panel unit to which the film obtained above was not attached was used ² 。

[ number 1]

Luminance average value La = (L1 + L2)/2

Luminance uniformity Lu = (| L1-L2 |/La) × 100

L1: for an average value of 2 panel units of an average value of luminance of 3 points between the center and a point at a position of 10cm up and down from the center within each panel unit,

l2: average value of brightness of 3 points of the center between the adjacent 2 panel units and the point at the position of 10cm up and down from the center.

Note that, as for the luminance, the evaluations a to C were judged to show good results. These results are shown in table 1 below.

(evaluation criterion of luminance)

A: average luminance value of 1000 (cd/m) ² ) In the above-mentioned manner,

b: luminance average value of 500 (cd/m) ² ) More than or less than 1000 (cd/m) ² )，

C: luminance average value of 200 (cd/m) ² ) Above and below 500 (cd/m) ² )，

D: luminance average value less than 200 (cd/m) ² )。

Further, for the seamless property, the evaluations a to C were judged to show good results. These results are shown in table 1 below.

(evaluation criteria for seamless Property)

A: the uniformity of the luminance is 6 or less,

b: the luminance uniformity is over 6 and below 12,

c: the luminance uniformity is over 12 and below 18,

d: the brightness uniformity exceeded 18.

From table 1 above, it was confirmed that the display devices using the films 1 to 7 of the present invention are excellent in both the seamless property and the luminance. On the other hand, it was confirmed that the films 8 and 9 of the light-transmitting layer a of the comparative example, which did not have particles, had poor seamless properties. In addition, it was confirmed that the display devices using the

films

10 and 11 having the total light transmittance of the light-transmitting layer a outside the range of the present invention were insufficient in one of the seamless property and the luminance.

Further, it was confirmed from the comparison of

films

1, 3 and 6 and the comparison of

films

2, 4 and 5 that the total light transmittance was in the range of 15 to 25%, the balance between the seamless property and the luminance was more favorable.

Further, it was confirmed from the comparison of the

films

3, 4 and 7 that the seamless property was further improved by the laminated film satisfying the relationship of Hz (A-B) < Hz (B-A). Further, from the comparison of the

films

1 and 2 and the comparison of the films 6 and 5, it was confirmed that the laminated film satisfies the relationship of Hz (A-B) < Hz (B-A), and the seamless property is further improved.

This application is based on japanese patent application No. 2020-117339, filed on 7/2020, the disclosure of which is hereby incorporated by reference in its entirety.

Description of the symbols

1: light-transmitting layer A

2: laminated film

3: light-transmitting layer B

3': layer or film to become the matrix (base) of the light-transmitting layer B

4: hard coating

10: panel unit

11: LED module

12: adhesive layer

20: independent module type display device

100: laminate (laminate film)

110: support (e.g., substrate layer such as light-transmitting layer B)

200: manufacturing apparatus

201: roll of support (e.g., substrate layer such as light-transmitting layer B)

210: supply part

220: coating section

221: support roller

222: coating head

223: decompression chamber

230: drying section

231: drying chamber

232: introducing port for drying gas

233: discharge outlet

240: cooling part

241: cooling chamber

242: cooling air inlet

243: cooling air outlet

250: winding part

251: roll of laminate (laminated film)

a. b, c, d: conveying roller

Claims

1. An optical film comprising a light-transmitting layer containing particles and a colorant and having a total light transmittance of 10% to 30%,

the display device is used for a display device with a display surface composed of a plurality of panel units.

2. The optical film according to claim 1, wherein the light-transmitting layer is a resin film.

3. The optical film according to claim 1 or 2, wherein the light-transmitting layer has a total light transmittance of 15% to 25%.

4. The optical film according to any one of claims 1 to 3, wherein the particles are inorganic oxide particles.

5. The optical film according to any one of claims 1 to 4, wherein the colorant is a pigment.

6. The optical film according to any one of claims 1 to 5, wherein the light-transmitting layer is a light-transmitting layer A, and the optical film further comprises a base material layer.

7. The optical film according to claim 6, wherein the base material layer is a resin film.

8. The optical film according to claim 6 or 7, wherein the base material layer is a light-transmitting layer B,

the light-transmitting layer B is disposed on the light-transmitting layer A,

when the haze of ase:Sub>A laminate of one light-transmitting layer A and one light-transmitting layer B is measured, the relationship between Hz (A-B) < Hz (B-A) is satisfied between the value Hz (A-B) (%) when light is incident from the side of the light-transmitting layer A and the value Hz (B-A) (%) when light is incident from the side of the light-transmitting layer B.

9. A panel unit comprising a light-emitting module and the optical film according to any one of claims 1 to 5, wherein the optical film is disposed on the display surface side of the light-emitting module,

10. A panel unit comprising a light-emitting module and the optical film according to any one of claims 6 to 8, wherein the optical film is disposed on the display surface side of the light-emitting module,

the base material layer is disposed on the display surface side of the light-transmitting layer A,

11. The panel unit according to claim 9 or 10, wherein the light emitting module comprises an LED element.

12. The panel unit according to claim 11, wherein the LED element has an LED light emitting chip and a resin cover covering the LED light emitting chip,

the LED element has a width W and a depth D of 300 [ mu ] m or less, a height H of 200 [ mu ] m or less,

the arrangement interval of each LED element is 0.03 mm-100 mm.

13. A display device having a display surface constituted by a plurality of panel units according to any one of claims 9 to 12.