JP7677342B2 - Light-reducing film, its manufacturing method, and laminate - Google Patents

Description

The present invention relates to a dimming film, a manufacturing method thereof, and a laminate.

Desired functions have been imparted to resin compositions by combining resins with functional materials (Patent Document 1).
Furthermore, a technique is known in which a film formed from a resin is colored and used for a polarizing plate (Patent Document 2).

International Publication No. 2016/163409 (Corresponding Foreign Publication: U.S. Patent Application Publication No. 2018/086029) JP 2004-151264 A

In order to reduce reflection of external light in an image display device, an anti-reflection film including a linear polarizer and a retardation plate is sometimes used. A linear polarizer is usually manufactured through a plurality of steps, and the manufacturing cost is high.
In addition, since an antireflection film containing a linear polarizer usually has a light transmittance of 50% or less, an image display device using such an antireflection film is usually used with a high brightness setting, resulting in high power consumption. Therefore, an optical film that does not contain a linear polarizer and has a reflection reducing function is required.
Furthermore, in order to reduce the effect on the image clarity of an image display device, it is preferable that the haze of the antireflection film is small.

Therefore, there is a demand for a new film that has the function of reducing the reflection of external light in image display devices and has low haze, as well as a method for manufacturing the same.

Means for Solving the Problems The present inventors conducted intensive research to solve the above problems, and as a result, discovered that the above problems could be solved by a film having a predetermined thickness containing a resin and an oil-soluble dye, and thus completed the present invention.
That is, the present invention provides the following.

[1] A composition comprising a resin and an oil-soluble dye,
The thickness is 1 μm or more and less than 100 μm,
A light-reducing film having a b ^* value in the CIE 1976 (L ^* , a ^* , b ^* ) color space of less than 0.
[2] The light-reducing film according to [1], wherein the ratio of the oil-soluble dye to the resin is 0.01% by weight or more and less than 2% by weight.
[3] The light-reducing film according to [1] or [2], wherein the resin contains an alicyclic structure-containing polymer.
[4] The light-reducing film according to [3], wherein the alicyclic structure-containing polymer is a cyclic olefin polymer or a hydrogenated product thereof.
[5] The light-reducing film according to any one of [1] to [4], having a linear transmittance of light with a wavelength of 550 nm of 25% or more and 85% or less.
[6] The light-reducing film according to any one of [1] to [5], wherein the linear transmittance of light having a wavelength of 480 nm is greater than the linear transmittance of light having a wavelength of 610 nm.
[7] A laminate comprising the light-reducing film according to any one of [1] to [6] and a thermoplastic resin layer having light-transmitting properties, wherein the light-reducing film is disposed directly on the surface of the thermoplastic resin layer.
[8] A method for producing the light-reducing film according to any one of [1] to [6],
preparing a coating liquid containing the resin, the oil-soluble dye, and a solvent;
The method includes a step of applying the coating liquid onto a surface of a base layer to form a coating film, and a step of removing the solvent from the coating film to obtain the light-reducing film.
How light-reducing film is manufactured.

According to the present invention, it is possible to provide a new light-reduction film having a function of reducing reflection of external light in an image display device and low haze; and a method for manufacturing the light-reduction film.

FIG. 1 is a cross-sectional view that illustrates a laminate according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view that illustrates a laminate according to a second embodiment of the present invention.

The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be modified and implemented as desired without departing from the scope of the claims of the present invention and their equivalents.

In the following description, the retardation in the in-plane direction of a layer, Re, is a value expressed as Re = (nx - ny) x d, unless otherwise specified. Here, nx represents the refractive index in the direction perpendicular to the thickness direction of the layer (in-plane direction) that gives the maximum refractive index. ny represents the refractive index in the in-plane direction of the layer that is perpendicular to the direction of nx. d represents the thickness of the layer. The measurement wavelength is 590 nm, unless otherwise specified.

[1. Light-reducing film]
A light-reducing film according to one embodiment of the present invention contains a resin and an oil-soluble dye, has a thickness of 1 μm or more and less than 100 μm, and has a b ^* value of less than 0 in the CIE 1976 (L ^* , a ^* , b ^* ) color space.
The light-reducing film usually contains a resin composition containing a resin and an oil-soluble dye, and is formed from the resin composition.

The light-reducing film may have a single-layer structure or a multi-layer structure. When the light-reducing film has a multi-layer structure, each of the layers constituting the light-reducing film usually contains a resin composition containing a resin and an oil-soluble dye, and is formed from the resin composition.
The light reducing film preferably has a single layer structure.

The dimming film may be in a form combined with other elements, for example, laminated with a substrate layer such as a resin film or a glass plate, or laminated with a layer such as a release film or a protective film.

[1.1. Resin]
The light reducing film contains a resin. The resin usually contains a polymer and, if necessary, any optional component.
Examples of resins that can be contained in the light reducing film include thermosetting resins and thermoplastic resins, with thermoplastic resins being preferred because the b ^* value is easily adjusted.
Examples of polymers that can be included in the thermoplastic resin include polymers containing an alicyclic structure, such as norbornene-based polymers; polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyarylene sulfides such as polyphenylene sulfide; polyvinyl alcohol; polycarbonate; polyarylate; cellulose ester polymers, polyethersulfone; polysulfone; polyarylsulfone; polyvinyl chloride; and rod-shaped liquid crystal polymers.

The polymer may be used alone or in any combination of two or more types in any ratio. The polymer may be a homopolymer or a copolymer. Among these, polymers containing an alicyclic structure are preferred because they have excellent mechanical properties, heat resistance, transparency, low moisture absorption, dimensional stability, and light weight. Hereinafter, polymers containing an alicyclic structure may be referred to as "alicyclic structure-containing polymers" as appropriate.

A polymer containing an alicyclic structure has a structural unit that contains an alicyclic structure. A polymer containing an alicyclic structure may have an alicyclic structure in the main chain or in the side chain.

Examples of alicyclic structures include saturated alicyclic hydrocarbon (cycloalkane) structures, unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structures, etc. Among these, from the viewpoints of mechanical strength and heat resistance, cycloalkane structures and cycloalkene structures are preferred, and cycloalkane structures are particularly preferred.

The number of carbon atoms constituting the alicyclic structure is preferably 4 or more, more preferably 5 or more, and preferably 30 or less, more preferably 20 or less, and particularly preferably 15 or less per alicyclic structure. When the number of carbon atoms constituting the alicyclic structure is within the above range, the mechanical strength, heat resistance, and moldability of the light-reducing film are highly balanced, which is preferable.

Examples of the polymer having an alicyclic structure include cyclic olefin polymers and hydrogenated products thereof; cyclic conjugated diene polymers and hydrogenated products thereof; and vinyl alicyclic hydrocarbon polymers and hydrogenated products thereof.
When the resin contains an alicyclic structure-containing polymer, the alicyclic structure-containing polymer in the resin may be one type, or may be a combination of two or more types in any ratio.For example, the resin may contain only one type selected from the group consisting of cyclic olefin polymers and their hydrogenated products, or may contain two or more types selected from the group consisting of cyclic olefin polymers and their hydrogenated products, or may contain an alicyclic structure-containing polymer other than the cyclic olefin polymer and its hydrogenated product (for example, the copolymer A described below).

(Cyclic olefin polymer and hydrogenated product thereof)
The cyclic olefin polymer is a polymer containing a structural unit having a structure obtained by polymerizing a cyclic olefin monomer. Examples of the cyclic olefin polymer include a monocyclic cyclic olefin polymer and a polycyclic cyclic olefin polymer.

In one embodiment, from the viewpoint of improving the transparency and moldability of the resin, the alicyclic structure-containing polymer that may be contained in the resin is preferably a cyclic olefin polymer or a hydrogenated product thereof, more preferably a polycyclic cyclic olefin polymer or a hydrogenated product thereof, and even more preferably a norbornene polymer or a hydrogenated product thereof.

In one embodiment, the proportion of the cyclic olefin polymer and its hydrogenated product in the resin is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, even more preferably 80% by weight or more, even more preferably 90% by weight or more, even more preferably 95% by weight or more, and is usually 100% by weight or less, and may be 100% by weight.

Examples of norbornene-based polymers and their hydrogenated products include ring-opening polymers of monomers having a norbornene structure, or ring-opening copolymers of monomers having a norbornene structure and other monomers; addition polymers of monomers having a norbornene structure, or addition copolymers of monomers having a norbornene structure and other monomers; and hydrogenated products thereof. Among these, ring-opening (co)polymer hydrogenated products of monomers having a norbornene structure are particularly suitable from the viewpoints of transparency, moldability, heat resistance, low moisture absorption, dimensional stability, light weight, etc. Here, "(co)polymer" refers to polymers and copolymers.

Examples of monomers having a norbornene structure include bicyclo[2.2.1]hept-2-ene (common name: norbornene), tricyclo[4.3.0.1 ^2,5 ]deca-3,7-diene (common name: dicyclopentadiene), 7,8-benzotricyclo[4.3.0.1 ^2,5 ]deca-3-ene (common name: methanotetrahydrofluorene), tetracyclo[4.4.0.1 ^2,5 .1 ^7,10 ]dodeca-3-ene (common name: tetracyclododecene), and derivatives of these compounds (for example, those having a substituent on the ring). Here, examples of the substituent include an alkyl group, an alkylene group, a polar group, and the like. In addition, these substituents may be the same or different, and a plurality of them may be bonded to the ring. In addition, the monomer having a norbornene structure may be used alone or in combination of two or more kinds at any ratio.

Examples of polar groups include heteroatoms and atomic groups having heteroatoms. Examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, and halogen atoms. Specific examples of polar groups include carboxyl groups, carbonyloxycarbonyl groups, epoxy groups, hydroxyl groups, oxy groups, ester groups, silanol groups, silyl groups, amino groups, nitrile groups, and sulfonic acid groups.

Examples of other monomers capable of ring-opening copolymerization with a monomer having a norbornene structure include monocyclic olefins and derivatives thereof, such as cyclohexene, cycloheptene, and cyclooctene; cyclic conjugated dienes and derivatives thereof, such as cyclohexadiene and cycloheptadiene; and the like. The other monomers capable of ring-opening copolymerization with a monomer having a norbornene structure may be used alone or in combination of two or more in any ratio.

Ring-opening polymers of monomers having a norbornene structure, as well as ring-opening copolymers of monomers having a norbornene structure and other monomers copolymerizable with monomers having a norbornene structure, may be produced, for example, by polymerizing or copolymerizing the monomers in the presence of a known ring-opening polymerization catalyst.

Examples of other monomers that can be addition-copolymerized with a monomer having a norbornene structure include α-olefins having 2 to 20 carbon atoms, such as ethylene, propylene, and 1-butene, and derivatives thereof; cycloolefins, such as cyclobutene, cyclopentene, and cyclohexene, and derivatives thereof; and non-conjugated dienes, such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, and 5-methyl-1,4-hexadiene. Among these, α-olefins are preferred, and ethylene is more preferred. In addition, the other monomers that can be addition-copolymerized with a monomer having a norbornene structure may be used alone or in combination of two or more types in any ratio.

Addition polymers of monomers having a norbornene structure, as well as addition copolymers of monomers having a norbornene structure and other monomers copolymerizable with monomers having a norbornene structure, may be produced, for example, by polymerizing or copolymerizing the monomers in the presence of a known addition polymerization catalyst.

Specific examples of norbornene-based polymers and their hydrogenated products include "ZEONOR" manufactured by Zeon Corporation; "ARTON" manufactured by JSR Corporation; and "TOPAS" manufactured by TOPAS ADVANCED POLYMERS.

Examples of monocyclic olefin polymers and their hydrogenated products include addition polymers of monocyclic olefin monomers such as cyclohexene, cycloheptene, and cyclooctene, and their hydrogenated products.

(Cyclic conjugated diene polymer and hydrogenated product thereof)
Examples of the cyclic conjugated diene polymer and its hydrogenated product include polymers obtained by cyclization reaction of addition polymers of conjugated diene monomers such as 1,3-butadiene, isoprene, and chloroprene; 1,2- or 1,4-addition polymers of cyclic conjugated diene monomers such as cyclopentadiene and cyclohexadiene; and hydrogenated products thereof.

(Vinyl alicyclic hydrocarbon polymers and their hydrogenated products)
Examples of the vinyl alicyclic hydrocarbon polymer include polymers of vinyl alicyclic hydrocarbon monomers such as vinylcyclohexene and vinylcyclohexane, and hydrogenated products thereof; hydrogenated products obtained by hydrogenating an aromatic ring moiety contained in a polymer obtained by polymerizing vinyl aromatic hydrocarbon monomers such as styrene and α-methylstyrene; hydrogenated products of aromatic rings of copolymers such as copolymers of vinyl alicyclic hydrocarbon monomers and other monomers, or copolymers such as random copolymers or block copolymers of vinyl aromatic hydrocarbon monomers and other monomers copolymerizable with these vinyl aromatic hydrocarbon monomers; etc. Examples of the block copolymers include diblock copolymers, triblock copolymers, or multiblock copolymers having more than one, as well as gradient block copolymers.

In one embodiment, the alicyclic structure-containing polymer that may be contained in the resin is one or more selected from the group consisting of hydrogenated aromatic vinyl compound-conjugated diene block copolymers (hereinafter also referred to as copolymer A) and hydrogenated aromatic vinyl compound-conjugated diene block copolymers modified with silicon atom-containing polar groups.

The hydrogenated aromatic vinyl compound-conjugated diene block copolymer is a hydrogenated product of an aromatic vinyl compound-conjugated diene block copolymer. The aromatic vinyl compound-conjugated diene block copolymer is a copolymer containing a block containing an aromatic vinyl compound unit and a block containing a conjugated diene unit.
The hydrogenated aromatic vinyl compound-conjugated diene block copolymer has a structure obtained by hydrogenating a part or all of the carbon-carbon unsaturated bonds in the main chain and side chain of the aromatic vinyl compound-conjugated diene block copolymer, the carbon-carbon unsaturated bonds in the aromatic ring, or both of them. However, in the present application, the hydrogenated product is not limited by its production method.

An aromatic vinyl compound unit is a structural unit having a structure obtained by polymerizing an aromatic vinyl compound, and a conjugated diene unit is a structural unit having a structure obtained by polymerizing a conjugated diene.

As aromatic vinyl compounds, styrene and its derivatives; vinylnaphthalene and its derivatives are preferred, with styrene being particularly preferred due to its ease of industrial availability. As conjugated dienes, chain conjugated dienes (straight-chain conjugated dienes, branched-chain conjugated dienes) are preferred, and specific examples thereof include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2,3-dimethyl-1,3-butadiene, and 1,3-pentadiene. Of these, 1,3-butadiene and isoprene are particularly preferred due to their ease of industrial availability.

The aromatic vinyl compound-conjugated diene block copolymer is preferably selected from styrene-butadiene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, styrene-isoprene-styrene block copolymers, and mixtures thereof. More specific examples of these include those described in prior art documents such as JP-A-2-133406, JP-A-2-305814, JP-A-3-72512, JP-A-3-74409, and WO 2015/099079.

The hydrogenation rate of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 90% or more, more preferably 97% or more, particularly preferably 99% or more, and is usually 100% or less. The higher the hydrogenation rate, the better the heat resistance and light resistance of the light reducing film. Here, the hydrogenation rate of the hydrogenated product can be determined by measurement using ^1H -NMR.

The hydrogenation rate of the carbon-carbon unsaturated bonds in the main chain and side chain of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 95% or more, more preferably 99% or more, and is usually 100% or less. By increasing the hydrogenation rate of the carbon-carbon unsaturated bonds in the main chain and side chain of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer, the light resistance and oxidation resistance of the light reduction film can be further improved.

The hydrogenation rate of the carbon-carbon unsaturated bonds in the aromatic rings of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferably 90% or more, more preferably 93% or more, particularly preferably 95% or more, and is usually 100% or less. By increasing the hydrogenation rate of the carbon-carbon unsaturated bonds in the aromatic rings, the glass transition temperature of the hydrogenated product increases, and the heat resistance of the light-reduction film can be effectively improved. Furthermore, the photoelastic coefficient of the light-reduction film can be lowered, reducing the occurrence of retardation.

As the hydrogenated aromatic vinyl compound-conjugated diene block copolymer, one having a structure in which both the unsaturated bonds derived from the conjugated diene and the aromatic rings are hydrogenated is preferred.

Particularly preferred block forms of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer are a triblock copolymer in which a block [A] of a hydrogenated aromatic vinyl polymer is bonded to both ends of a block [B] of a hydrogenated conjugated diene polymer; or a pentablock copolymer in which a polymer block [B] is bonded to both ends of a polymer block [A], and a polymer block [A] is bonded to the other ends of each of the polymer blocks [B]. In particular, a triblock copolymer of [A]-[B]-[A] is particularly preferred from the viewpoint of ease of production.

When the mass fraction of all aromatic vinyl compound monomer units in the entire block copolymer is wA, and the mass fraction of all conjugated diene monomer units in the block copolymer in the entire block copolymer is wB, the ratio of wA to wB (wA/wB) is preferably 20/80 or more, more preferably 30/70 or more, and preferably 60/40 or less, more preferably 55/45 or less. By making the ratio wA/wB equal to or greater than the lower limit of the range, the heat resistance of the light-reducing film can be improved. Also, by making it equal to or less than the upper limit, the flexibility of the light-reducing film can be increased.

The modified product of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer (copolymer A) with a silicon atom-containing polar group has a structure obtained by graft polymerization of the hydrogenated aromatic vinyl compound-conjugated diene block copolymer and a compound having a silicon atom-containing polar group as a monomer, however, the modified product is not limited by its production method.
The silicon atom-containing polar group is preferably an alkoxysilyl group.

Examples of compounds having a silicon atom-containing polar group that can be used as a monomer for graft polymerization include ethylenically unsaturated silane compounds having an alkoxysilyl group, such as vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, dimethoxymethylvinylsilane, diethoxymethylvinylsilane, p-styryltrimethoxysilane, p-styryltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-acryloxypropyltriethoxysilane, and 2-norbornene-5-yltrimethoxysilane.

By reacting copolymer A with a compound having a silicon atom-containing polar group, a silicon atom-containing polar group can be introduced into copolymer A, and a modified product having a silicon atom-containing polar group can be obtained. When an alkoxysilyl group is introduced as a silicon atom-containing polar group, the amount of alkoxysilyl group introduced is preferably 0.1 parts by weight or more, more preferably 0.2 parts by weight or more, and even more preferably 0.3 parts by weight or more, and preferably 10 parts by weight or less, more preferably 5 parts by weight or less, and even more preferably 3 parts by weight or less, per 100 parts by weight of copolymer A. When the amount of alkoxysilyl group introduced is within the above range, it is possible to prevent the degree of crosslinking between alkoxysilyl groups decomposed by moisture or the like from becoming excessively high, so that high adhesion can be maintained. Examples of substances having alkoxysilyl groups used for introducing alkoxysilyl groups and modification methods include those described in prior art documents such as International Publication No. WO 2015/099079.

The amount of polar group introduced can be measured by ¹ H-NMR spectroscopy. When the amount of polar group introduced is small, the number of integrations can be increased.

Introducing an alkoxysilyl group as a polar group into copolymer A is called silane modification. In the silane modification, the alkoxysilyl group may be bonded directly to copolymer A, or may be bonded via a divalent organic group such as an alkylene group. Hereinafter, the polymer obtained by silane modification of copolymer A is also referred to as a "silane modified product."

As the modified product of copolymer A with a silicon atom-containing polar group, a silane-modified product of a hydrogenated aromatic vinyl compound-conjugated diene block copolymer is preferred, and one or more silane-modified products selected from a silane-modified product of a hydrogenated styrene-butadiene block copolymer, a silane-modified product of a hydrogenated styrene-butadiene-styrene block copolymer, a silane-modified product of a hydrogenated styrene-isoprene block copolymer, and a silane-modified product of a hydrogenated styrene-isoprene-styrene block copolymer are preferred.

In one embodiment, the alicyclic structure-containing polymer that may be contained in the resin is preferably a modified product of copolymer A with a silicon atom-containing polar group; more preferably a modified product of copolymer A with an alkoxysilyl group; and even more preferably one or more silane-modified products selected from a silane-modified product of a hydrogenated styrene-butadiene-styrene block copolymer, a silane-modified product of a hydrogenated styrene-isoprene block copolymer, and a silane-modified product of a hydrogenated styrene-isoprene-styrene block copolymer.

In one embodiment, the proportion of modified copolymer A with a silicon atom-containing polar group in the resin is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, even more preferably 80% by weight or more, even more preferably 90% by weight or more, even more preferably 95% by weight or more, and is usually 100% by weight or less, and may be 100% by weight.

The weight average molecular weight (Mw) of the alicyclic structure-containing polymer is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, and preferably 200,000 or less, more preferably 100,000 or less, even more preferably 80,000 or less. An alicyclic structure-containing polymer having such a weight average molecular weight has an excellent balance of mechanical strength, moldability, and heat resistance.

The molecular weight distribution (Mw/Mn) of the alicyclic structure-containing polymer is preferably 1 or more, preferably 4 or less, and more preferably 3.5 or less. When the molecular weight distribution is equal to or more than the lower limit of the above range, the productivity of the alicyclic structure-containing polymer can be increased and the manufacturing cost can be reduced. When the molecular weight distribution is equal to or less than the upper limit, the amount of low molecular weight components is reduced, and the stability of the layer containing the alicyclic structure-containing polymer can be increased.

The weight average molecular weight Mw and number average molecular weight Mn of the alicyclic structure-containing polymer can be measured in polyisoprene equivalent values by gel permeation chromatography (hereinafter abbreviated as "GPC") using cyclohexane as a solvent. If the resin does not dissolve in cyclohexane, they can be measured in polystyrene equivalent values by GPC using toluene or tetrahydrofuran as a solvent.

The glass transition temperature of the alicyclic structure-containing polymer is preferably 50°C or higher, more preferably 70°C or higher, and preferably 200°C or lower, more preferably 180°C or lower.

When the resin contains a polymer containing an alicyclic structure, the proportion of the polymer containing an alicyclic structure in the resin is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, even more preferably 80% by weight or more, even more preferably 90% by weight or more, even more preferably 95% by weight or more, and is usually 100% by weight or less, and may be 100% by weight.

Examples of optional components other than the polymer that the resin may contain include antioxidants, plasticizers, ultraviolet absorbers, and lubricants. The optional components may be used alone or in combination of two or more in any ratio.
The total proportion of any components other than the polymer in the resin is preferably 5% by weight or less, more preferably 3% by weight or less, and even more preferably 1% by weight or less, and is usually 0% by weight or more, and may be 0% by weight.

[1.2. Oil-soluble dye]
The light-reducing film contains an oil-soluble dye, which means a dye classified as "Solvent Dye" in the Color Index (a database created by the British Society of Dyestuffs and Textile Chemists and the American Association of Textile Chemists and Dyeers).

Specific examples of yellow oil-soluble dyes include Oil Yellow 105 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Oil Yellow 107 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Oil Yellow 129 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Yellow 29), Oil Yellow 3G (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Yellow 16), Oil Yellow GGS (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Yellow 56), Varifast Yellow 1101 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Yellow Yellow 1105 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Yellow 4120 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Yellow 82), Oleosol Brilliant Yellow 5G (trade name, manufactured by Taoka Chemical Industry Co., Ltd., C.I. Solvent Yellow 150), Oleosol Fast Yellow 2G (trade name, manufactured by Taoka Chemical Industry Co., Ltd., C.I. Solvent Yellow 21), Oleosol Fast Yellow GCN (trade name, manufactured by Taoka Chemical Industry Co., Ltd., C.I. Solvent Yellow 151), Eisenzot Yellow 1 (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., C.I. Solvent Yellow 22), Solvent Yellow 56), Eisenzot Yellow 3 (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I. Solvent Yellow 16), Eisenzot Yellow 6 (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I. Solvent Yellow 33), Eisenspiron Yellow GRLH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Eisenspiron Yellow 3RH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Orasol Yellow 2GLN (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Yellow 88), Orasol Yellow 2RLN (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Yellow Solvent Yellow 25 (manufactured by Ciba-Geigy Corporation), Orasol Yellow 3R (trade name, manufactured by Ciba-Geigy Corporation, C.I. Solvent Yellow 25), Oraset Yellow GHS (trade name, manufactured by Ciba-Geigy Corporation, C.I. Solvent Yellow 163), Filamid Yellow R (trade name, manufactured by Ciba-Geigy Corporation, C.I. Solvent Yellow 21), Oil Yellow 185 (trade name, manufactured by Chuo Synthetic Chemical Industry Co., Ltd., a product similar to C.I. Solvent Red 18), Alcohol Yellow Y-10 (trade name, manufactured by Chuo Synthetic Chemical Industry Co., Ltd.), and Dia Resin Yellow L3G (trade name, manufactured by Mitsubishi Kasei Corporation, C.I. Solvent Yellow 93).

Specific examples of red oil-soluble dyes include Oil Red 5B (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Red 27), Oil Red RR (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Red 24), Varifast Red 1306 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Red 109), Varifast Red 1355 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Red 2303 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Red 3304 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Red 8), Varifast Red 3306 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Red 3320 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Red 132), and Oil Pink 312 (trade name, Orient Chemical Industry Co., Ltd.). Orient Chemical Industry Co., Ltd.), Varifast Pink 2310N (trade name, Orient Chemical Industry Co., Ltd., C.I. Solvent Red 218), Oleosol Fast Red BL (trade name, Taoka Chemical Industry Co., Ltd., C.I. Solvent Red 132), Oleosol Fast Red RL (trade name, Taoka Chemical Industry Co., Ltd., C.I. Solvent Red 122), Oleosol Fast Red GL (trade name, Taoka Chemical Industry Co., Ltd., C.I. Solvent Red 132), Oleosol Red 2G (trade name, Taoka Chemical Industry Co., Ltd.), Oleosol Fast Pink FB (trade name, Taoka Chemical Industry Co., Ltd., C.I. Solvent Red 218), Eisenzoth Red 1 (trade name, Hodogaya Chemical Industry Co., Ltd., C.I. Solvent Red 24), Eisenzoth Red 2 (trade name, Hodogaya Chemical Industry Co., Ltd., C.I. Solvent Red 27), Aizenzot Red 3 (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I. Solvent Red 18), Aizen Spiron Red BEH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Spiron Fiery Red BH (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I. Solvent Red 81), Aizen Spiron Red GEH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Spiron Red C-GH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Zot Pink 1 (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I. Solvent Red 49), Orasol Red 3GL (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Red 130), Orasol Red 2BL (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Red 132), Orasol Red G (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Red 125 ...3GL (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Red 132), Orasol Red G (trade name, manufactured by Ciba-Geigy Co. Examples of the pigments include Lasol Red B (trade name, manufactured by Ciba-Geigy, C.I. Solvent Red 7), Filamid Red GR (trade name, manufactured by Ciba-Geigy, C.I. Solvent Red 225), Firestar Red GA (trade name, manufactured by Ciba-Geigy, C.I. Solvent Red 135), Firestar Red RBA (trade name, manufactured by Ciba-Geigy, C.I. Solvent Red 230), Orasol Pink 5 BLG (trade name, manufactured by Ciba-Geigy, C.I. Solvent Red 127), Oil Pink 330 (trade name, manufactured by Chuo Synthetic Chemical Industry Co., Ltd., C.I. Solvent Red 49), Alcohol Pink P-30 (trade name, manufactured by Chuo Synthetic Chemical Industry Co., Ltd.), Dia Resin Red K (trade name, manufactured by Mitsubishi Kasei Corporation, C.I. Solvent Red 155), and Dia Resin Red H5B (trade name, manufactured by Mitsubishi Kasei Corporation, C.I. Solvent Red 52).

Specific examples of blue oil-soluble dyes include Oil Blue 613 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Oil Blue 2N (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Blue 35), Oil Blue BOS (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Blue 1603 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Blue 1605 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Blue 38), Varifast Blue 1607 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), and Varifast Blue 2606 (trade name, manufactured by Orient Chemical Industry Co., Ltd.). Solvent Blue 70 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Blue 2610 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Oleosol Fast Blue ELN (trade name, manufactured by Taoka Chemical Industry Co., Ltd., C.I. Solvent Blue 70), Oleosol Fast Blue GL (trade name, manufactured by Taoka Chemical Industry Co., Ltd., C.I. Solvent Blue 70), Oleosol Blue G (trade name, manufactured by Taoka Chemical Industry Co., Ltd.), Eisenzoth Blue 1 (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd., C.I. Solvent Blue 25), Eisenzoth Blue 2 (trade name, manufactured by Hodogaya Chemical Industry Co., Ltd.) Solvent Blue 14, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Spiron Blue GNH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Spiron Blue 2BNH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Spiron Blue BPNH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Aizen Spiron Blue E2BH (trade name, manufactured by Hodogaya Chemical Co., Ltd., C.I. Solvent Blue 73), Orasol Blue GN (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Blue 67), Orasol Blue 2GLN (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Blue 48), Orasol Blue GN (trade name, manufactured by Ciba-Geigy Co., Ltd., C.I. Solvent Blue 67), Orasol Blue 2GLN ... Examples of such pigments include Russet Blue 2R (trade name, manufactured by Ciba-Geigy, C.I. Solvent Blue 68), Oil Blue BO (trade name, manufactured by Chuo Synthetic Chemical Industry Co., Ltd., C.I. Solvent Blue 25), Filamid Blue R (trade name, manufactured by Ciba-Geigy, C.I. Solvent Blue 132), Firestar Blue GN (trade name, manufactured by Ciba-Geigy, C.I. Solvent Blue 67), Kayaset Blue K-FL (trade name, manufactured by Nippon Kayaku Co., Ltd.), Alcohol Blue B-10 (trade name, manufactured by Chuo Synthetic Chemical Industry Co., Ltd.), and Dia Resin Blue H3G (trade name, manufactured by Mitsubishi Kasei Corporation).

Specific examples of black oil-soluble dyes include Oil Black HBB (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 3), Oil Black 860 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 3), Oil Black BS (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 7), Oil Black BY (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Black 1802 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Black 1807 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Varifast Black 3804 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 34), Varifast Black 3810 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 29), Varifast Black 3820 (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 27), Varifast Black 3830 (trade name, manufactured by Orient Chemical Industry Co., Ltd.), Spirit Black SB (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 5), Spirit Black SSBB (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 5), Spirit Black AB (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 5), Nigrosine Base (trade name, manufactured by Orient Chemical Industry Co., Ltd., C.I. Solvent Black 7), Oleosol Fast Black RL (trade name, manufactured by Taoka Chemical Industry Co., Ltd., C.I. Solvent Black 27), Oleosol Black AR (trade name, manufactured by Taoka Chemical Industry Co., Ltd.), Eisenzot Black 6 (trade name, Examples of the solvent include C.I. Solvent Black 3, manufactured by Hodogaya Chemical Co., Ltd.), Eisen Zot Black 8 (trade name, C.I. Solvent Black 7, manufactured by Hodogaya Chemical Co., Ltd.), Eisen Spiron Black MH (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Eisen Spiron Black GMH Special (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Eisen Spiron Black RLH Special (trade name, manufactured by Hodogaya Chemical Co., Ltd.), Orasol Black CN (trade name, C.I. Solvent Black 28, manufactured by Ciba-Geigy Co., Ltd.), Orasol Black RLI (trade name, C.I. Solvent Black 29, manufactured by Ciba-Geigy Co., Ltd.), and Oil Black FS Special A (trade name, C.I. Solvent Black 7, manufactured by Chuo Synthetic Chemical Co., Ltd.).

The oil-soluble dyes may be used alone or in any combination of two or more in any ratio. In addition, oil-soluble dyes that dissolve in cyclohexane at room temperature (preferably 20±5°C) at 0.02% by weight or more are preferred. By using such oil-soluble dyes, it becomes easy to combine them with various thermoplastic resins (e.g., resins containing alicyclic structure-containing polymers).

The ratio of oil-soluble dye to resin is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, from the viewpoint of effectively imparting dimming properties to the dimming film, and is preferably less than 2% by weight, more preferably 1.5% by weight or less, from the viewpoint of effectively reducing the haze of the dimming film.
Here, the ratio of the oil-soluble dye is a value when the weight of the resin contained in the light-reducing film is taken as 100% by weight.

[1.3. Thickness of light-reducing film]
The thickness of the light-reduction film is usually 1 μm or more, preferably 1.5 μm or more, and more preferably 2 μm or more, from the viewpoint of imparting light-reduction properties to the light-reduction film, and is usually less than 100 μm, preferably 50 μm or less, and more preferably 20 μm or less, from the viewpoint of reducing the haze of the light-reduction film.

The thickness of the light-reducing film can be adjusted by a conventional method according to the manufacturing method of the light-reducing film. For example, when the light-reducing film is manufactured by a coating method using an applicator, the thickness can be adjusted by adjusting the viscosity of the coating liquid by adjusting the amount of solvent, or by adjusting the gap of the applicator that applies the coating liquid.

The thickness of the light-reducing film can be measured by a micro-shape measuring device, a spectroscopic film thickness measuring device, etc. For example, if the light-reducing film is formed on a base layer such as a release film, the thickness can be measured by peeling a portion of the light-reducing film from the base layer and measuring the step shape between the surface of the base layer and the surface of the light-reducing film with a micro-shape measuring device.

[1.4. b ^* value of light reducing film]
The light-reduction film has a b ^* value in the CIE 1976 (L ^* , a ^* , b ^* ) color space that is usually less than 0, preferably -1 or less, and more preferably -2 or less. This balances the linear transmittance of light in the blue region of the light-reduction film with the light-reduction properties of the light-reduction film. Therefore, the light-reduction film can be suitably used as an anti-reflection film for an image display device (e.g., an organic electroluminescence image display device) that has a reflective element and in which the emission intensity in the blue region is smaller than the emission intensity in other regions.
The b* value of the light reducing film is preferably −40 or more, more preferably −25 or more.

The b ^* value of the light reducing film can be measured by a colorimeter.

The b ^* value of the light-reducing film can be adjusted by adjusting the color and concentration of the oil-soluble dye contained in the light-reducing film.

[1.5. Linear light transmittance of light reducing film]
The light reducing film preferably has a linear transmittance T ₅₅₀ of light with a wavelength of 550 nm of usually 25% or more, preferably 27.5% or more, more preferably 30% or more, and usually 85% or less, preferably 80% or less, more preferably 75% or less.
By having the linear transmittance of light having a wavelength of 550 nm within the above range, the light-reducing properties of the light-reducing film can be made more appropriate. As a result, when the light-reducing film is used as an anti-reflection film of an image display device, the image display device can achieve both image clarity and reflection reduction performance.

The light reducing film preferably has a linear transmittance _T480 of light having a wavelength of 480 nm greater than a linear transmittance _T610 of light having a wavelength of 610 nm. This allows the light reducing film to be suitably used as an anti-reflection film for an image display device (e.g., an organic electroluminescence image display device) that has a reflective element and in which the emission intensity in the blue region is smaller than the emission intensity in other regions.

The difference (T ₄₈₀ -T ₆₁₀ ) between the linear transmittance T ₄₈₀ of light having a wavelength of 480 nm and the linear transmittance T ₆₁₀ of light having a wavelength of 610 nm is preferably 2% or more, more preferably 3% or more, even more preferably 5% or more, and is preferably 30% or less, more preferably 25% or less, even more preferably 21% or less or 20% or less.

The in-line transmittance of light can be measured using a spectrophotometer.

[1.6. Characteristics of light-reducing film]
The light reducing film has a low haze value. The haze value of the light reducing film is preferably 1% or less, more preferably 0.5% or less, further preferably 0.3% or less, and is usually 0% or more.
The haze value of the light reducing film can be measured by a haze meter.

[1.7. Uses of light-reducing film]
As described above, the light-reducing film has a low haze value and a light-reducing function, and therefore can be suitably used as an anti-reflection film that reduces reflected light in an image display device without significantly impairing the clarity of the image.

[2. Laminate]
A laminate according to one embodiment of the present invention includes the light-reducing film and a light-transmitting thermoplastic resin layer. The light-reducing film is disposed directly on the surface of the thermoplastic resin layer. The laminate has the above-mentioned structure, and thus curling of the laminate can be reduced.

Examples and preferred examples of the light-reduction film contained in the laminate are the same as the examples and preferred examples of the light-reduction film described above.

The thermoplastic resin layer is a layer containing a thermoplastic resin and formed from a thermoplastic resin. The thermoplastic resin usually contains a thermoplastic polymer and, if necessary, any optional components. Examples of polymers that can be contained in the thermoplastic resin include the same examples as those that can be contained in the light reducing film. Among these examples, alicyclic structure-containing polymers are preferred because they are excellent in mechanical properties, heat resistance, transparency, low moisture absorption, dimensional stability, and light weight.
Among the alicyclic structure-containing polymers, cyclic olefin polymers and hydrogenated products thereof are preferred, and norbornene polymers and hydrogenated products thereof are more preferred.

The proportion of polymer in the thermoplastic resin is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, even more preferably 80% by weight or more, even more preferably 90% by weight or more, even more preferably 95% by weight or more, and is usually 100% by weight or less, and may be 100% by weight.

Optional components that may be contained in the thermoplastic resin include an antioxidant, a plasticizer, an ultraviolet absorber, and a lubricant. The optional components may be used alone or in combination of two or more in any ratio.
The total proportion of any components other than the polymer in the resin is preferably 5% by weight or less, more preferably 3% by weight or less, and even more preferably 1% by weight or less, and is usually 0% by weight or more, and may be 0% by weight.

The thermoplastic resin layer has light-transmitting properties. Here, "having light-transmitting properties" means that the linear light transmittance is 85% or more in the wavelength range of 480 nm or more and 610 nm or less. The linear light transmittance of the thermoplastic resin layer in that wavelength range is usually 100% or less. The thermoplastic resin layer having light-transmitting properties can impart optical properties such as light-reduction properties of a light-reduction film to the laminate.

The thickness of the thermoplastic resin layer is preferably 20 μm or more, more preferably 30 μm or more, and even more preferably 50 μm or more, from the viewpoint of further reducing curling of the laminate, and is preferably 250 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less, from the viewpoint of making the laminate thinner.

(Embodiment 1)
1 is a cross-sectional view showing a laminate according to a first embodiment of the present invention. The laminate 100 includes a light-reducing film 110 and a thermoplastic resin layer 120. The light-reducing film is disposed directly on one surface 120U of the thermoplastic resin layer 120.

(Embodiment 2)
In another embodiment, the laminate may include a first light reducing film, a second light reducing film, and a thermoplastic layer.
2 is a cross-sectional view showing a laminate according to a second embodiment of the present invention. The laminate 200 includes a first light-reducing film 210, a thermoplastic resin layer 220, and a second light-reducing film 230 in this order. The first light-reducing film 210 is disposed directly on one surface 220U of the thermoplastic resin layer 220. The second light-reducing film 230 is disposed directly on the other surface 220D of the thermoplastic resin layer 220.
In the laminate of this embodiment, light-reducing films are disposed directly on both sides of the thermoplastic resin layer, which can effectively reduce curling of the laminate.

The first light-reducing film and the second light-reducing film may differ in the content ratio of the oil-soluble dye, thickness, b ^* value, etc. From the viewpoint of simplifying the manufacturing process and effectively reducing curling of the laminate, the first light-reducing film and the second light-reducing film are preferably the same type of film.

(Optical Properties of Laminate)
The retardation Re of the laminate in the in-plane direction can have any value.
In one embodiment, the retardation Re of the laminate in the in-plane direction may be 20 nm to 200 nm, or 200 nm to 350 nm, so that the light reducing film can also function as a phase difference film such as a λ/4 plate or a λ/2 plate.
In one embodiment, the in-plane retardation Re of the laminate may be from 0 nm to 20 nm.

[3. Manufacturing method of light-reducing film]
The light-reducing film can be produced by any method. It is preferable to produce the light-reducing film by a coating method, since this method allows a thin film to be produced relatively stably.

The light-reducing film can be produced, for example, by a method including the following steps (1) to (3).
Step (1) preparing a coating liquid containing the resin, the oil-soluble dye, and a solvent; Step (2) applying the coating liquid onto a surface of a substrate layer to form a coating film; and Step (3) removing the solvent from the coating film to obtain the light-reducing film.
Step (1), step (2), and step (3) are usually carried out in this order.

[3.1. Process (1)]
In step (1), a coating liquid is prepared. The coating liquid contains a resin, an oil-soluble dye, and a solvent.
As the solvent, from the viewpoint of reducing the haze of the light-reducing film and distributing the oil-soluble dye uniformly in the light-reducing film, a solvent capable of dissolving the components contained in the light-reducing film, such as the resin and the oil-soluble dye, is preferred.

Examples of solvents include aliphatic or alicyclic hydrocarbon solvents (e.g., pentane, hexane, cyclopentane, cyclohexane, decahydronaphthalene), aromatic hydrocarbon solvents (e.g., toluene, xylene, trimethylbenzene, ethylbenzene, tetrahydronaphthalene), halogenated hydrocarbon solvents (e.g., dichloromethane, chloroform, dichloroethane, chlorobenzene), ether solvents (e.g., 1,4-dioxane, tetrahydrofuran), and ketone solvents (e.g., dimethyl ketone, cyclopentanone).

The amount of solvent in the coating liquid may be any amount depending on the desired viscosity of the coating liquid, the thickness of the coating film to be formed, etc. The amount of solvent in the coating liquid is not particularly limited, but is preferably 1 part by weight or more, more preferably 1.5 parts by weight or more, and even more preferably 3 parts by weight or more, and is preferably 20 parts by weight or less, more preferably 10 parts by weight or less, per 1 part by weight of resin.

The ratio of oil-soluble dye to resin in the coating liquid may be the same as the ratio of oil-soluble dye to resin in the light-reducing film.

The coating liquid may be prepared by any method. For example, an oil-soluble dye may be dissolved in a solvent to prepare a dye solution, and a resin may be added to the dye solution. In preparing the coating liquid, the dye solution may be filtered through a filter.

In the coating liquid, the oil-soluble dye may be in a state of being dissolved in a solvent. Here, the state in which the oil-soluble dye is dissolved does not mean a state in which the oil-soluble dye is emulsified, nor a state in which the oil-soluble dye is dispersed in a dispersion medium as solid particles, but a state in which the oil-soluble dye and the solvent form a homogeneous system.

[3.2. Process (2)]
In step (2), the coating liquid is applied onto the surface of the substrate layer to form a coating film.
Any layer can be used as the substrate layer. For example, a glass plate or a release film that has been subjected to a release treatment (e.g., a release polyethylene terephthalate (PET) film) may be used as the substrate layer, or a thermoplastic resin layer contained in the laminate may be used.
The base layer is preferably the thermoplastic resin layer, more preferably a layer made of a resin containing an alicyclic structure-containing polymer, still more preferably a layer made of a resin containing a cyclic olefin polymer or a hydrogenated product thereof, and particularly preferably a layer made of a norbornene polymer or a hydrogenated product thereof.
Examples and preferred examples of the alicyclic structure-containing polymer, cyclic olefin polymer and its hydrogenated product, and norbornene polymer and its hydrogenated product that can be contained in the resin that forms the base layer include the same examples as the polymer that can be contained in the light-reducing film.

Coating can be performed by any method. Examples of coating methods include curtain coating, extrusion coating, roll coating, spin coating, dip coating, bar coating, spray coating, slide coating, print coating, gravure coating, die coating, gap coating, and dipping.

The thickness of the coating film may be set appropriately depending on the resin concentration in the coating liquid, the desired thickness of the light-reducing film, etc.

[3.3. Process (3)]
In step (3), the solvent is removed from the coating film to obtain the light-reducing film.
The solvent may be removed by any method, including, for example, natural drying, heat drying, drying under reduced pressure, and heat drying under reduced pressure.
As long as the effect of the present invention is not hindered, the solvent does not have to be completely removed from the coating film. Therefore, the light-reducing film obtained by this manufacturing method may contain a solvent as long as the effect of the present invention is not hindered. Preferably, the amount of the solvent in the light-reducing film is 1% by weight or less, usually 0% by weight or more, and may be 0% by weight.

3.4. Optional steps
The method for producing the light-reducing film may include any other steps in addition to the steps (1) to (3).

Examples of optional steps include a step of peeling the light-reducing film obtained in step (3) from the base layer; a step of transferring the light-reducing film obtained in step (3) to a transfer target; and a step of winding up the light-reducing film.

[4. Manufacturing method of laminate]
The laminate can be produced by any method. For example, in the method for producing a light-reducing film including the steps (1) to (3), a thermoplastic resin layer can be used as the base layer to produce the laminate. In addition, by performing steps (2) and (3) multiple times, a coating film can be formed on both sides of the base layer (thermoplastic resin layer), and a laminate including a first light-reducing film and a second light-reducing film can be obtained.
Furthermore, the method for producing the laminate may include any step other than steps (1) to (3), such as a step of stretching the laminate obtained by steps (1) to (3).

The present invention will be described in detail below with reference to examples. However, the present invention is not limited to the examples shown below, and may be modified as desired without departing from the scope of the claims of the present invention and the scope of equivalents thereto.

In the following explanation, the percentages and parts are by weight unless otherwise specified. Furthermore, the operations described below were carried out at room temperature and pressure unless otherwise specified.

[Evaluation method]
(In-line transmittance of light-reducing film)
Using a spectrophotometer ("V-570" manufactured by JASCO Corporation), the linear light transmittance of the light reducing film was measured in the wavelength range of 400 nm to 700 nm.

(Haze value)
The haze value of the light-reducing film was measured using a haze meter ("NDH4000" manufactured by Nippon Denshoku Industries Co., Ltd.) in accordance with JIS K7136.

(Thickness of light reducing film)
A part (about 5 mm square) of the light-reducing film on the release PET film was peeled off from the release PET film, and the step shape between the release PET film surface and the light-reducing film surface was measured with a micro shape measuring device ("Surfcorder ET-4000A" manufactured by Kosaka Laboratory) to measure the thickness of the light-reducing film. When the light-reducing film was formed on a base layer, the total thickness of the light-reducing film and the base layer was measured with a micrometer ("MDC-25MJ" manufactured by Mitutoyo Corporation), and the thickness of the light-reducing film was calculated by subtracting the thickness of the base layer.

(b ^* value in CIE 1976 (L ^* , a ^* , b ^* ) color space)
The measurement was performed using a colorimeter ("SC-T" manufactured by Suga Test Instruments Co., Ltd.).

[Production Example 1]
(P1-1. Production of hydrogenated block copolymer (hydrogenated aromatic vinyl compound-conjugated diene block copolymer))
A hydrogenated block copolymer was produced by the following procedure using styrene as the aromatic vinyl compound and isoprene as the linear conjugated diene compound. The hydrogenated block copolymer produced has a triblock structure in which polymer block [A] is bonded to both ends of polymer block [B].

256 parts of dehydrated cyclohexane, 25.0 parts of dehydrated styrene, and 0.615 parts of n-dibutyl ether were placed in a reactor equipped with a stirrer and the inside of the reactor was thoroughly replaced with nitrogen. 1.35 parts of n-butyllithium (15% solution in cyclohexane) was added with stirring at 60°C to initiate polymerization, and the reaction was continued for 60 minutes at 60°C with stirring. The polymerization conversion rate at this point was 99.5% (the polymerization conversion rate was measured by gas chromatography; the same applies below).

Next, 50.0 parts of dehydrated isoprene was added, and stirring was continued at the same temperature for 30 minutes. At this time, the polymerization conversion rate was 99%.
Thereafter, 25.0 parts of dehydrated styrene was further added and stirred at the same temperature for 60 minutes. At this time, the polymerization conversion rate was nearly 100%.
Next, 0.5 parts of isopropyl alcohol was added to the reaction solution to terminate the reaction, thereby obtaining a solution (i) containing a block copolymer.
The weight average molecular weight (Mw) of the block copolymer in the obtained solution (i) was 44,900, and the molecular weight distribution (Mw/Mn) was 1.03 (measured in terms of polystyrene by gel permeation chromatography using tetrahydrofuran as a solvent; the same applies below).

Next, solution (i) was transferred to a pressure-resistant reactor equipped with a stirrer, and 4.0 parts of a silica-alumina supported nickel catalyst (E22U, nickel loading 60%; manufactured by JGC Chemical Industries, Ltd.) as a hydrogenation catalyst and 350 parts of dehydrated cyclohexane were added and mixed to solution (i). The inside of the reactor was replaced with hydrogen gas, and hydrogen was further supplied while stirring the solution, and the hydrogenation reaction was carried out at a temperature of 170°C and a pressure of 4.5 MPa for 6 hours to hydrogenate the block copolymer, thereby obtaining a solution (iii) containing a hydrogenated block copolymer (ii). The weight average molecular weight (Mw) of the hydrogenated product (ii) in solution (iii) was 45,100, and the molecular weight distribution (Mw/Mn) was 1.04.

After completion of the hydrogenation reaction, solution (iii) was filtered to remove the hydrogenation catalyst. Then, 1.0 part of a xylene solution containing 0.1 part of a phosphorus-based antioxidant, 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetrakis-t-butyldibenzo[d,f][1.3.2]dioxaphosphepine (Sumitomo Chemical Co., Ltd., Sumilizer (registered trademark) GP; hereinafter referred to as "antioxidant A"), was added to the filtered solution (iii) and dissolved to obtain solution (iv).

Next, the solution (iv) was filtered through a Zeta Plus (registered trademark) filter 30H (manufactured by Cuno, pore size 0.5 μm to 1 μm) and then successively filtered through another metal fiber filter (pore size 0.4 μm, manufactured by Nichidai Corporation) to remove minute solids. From the filtered solution (iv), the solvent cyclohexane, xylene, and other volatile components were removed at a temperature of 260° C. and a pressure of 0.001 MPa or less using a cylindrical concentrating dryer (product name "CONTRO", manufactured by Hitachi, Ltd.). Then, the solids were extruded in a molten state into strands from a die directly connected to the concentrating dryer, cooled, and cut with a pelletizer to obtain 85 parts of pellets (v) containing a hydrogenated block copolymer and antioxidant A. The weight average molecular weight (Mw) of the hydrogenated block copolymer (hydrogenated block copolymer) in the obtained pellets (v) was 45,000, and the molecular weight distribution (Mw/Mn) was 1.08. The hydrogenation rate measured by ¹ H-NMR was 99.9%.
A film-like test piece was prepared from the pellets (v), and the glass transition temperature Tg was evaluated by the tan δ peak using a dynamic viscoelasticity measuring device, and was found to be 130°C.

(P2-1. Production of silane-modified hydrogenated block copolymer)
To 100 parts of the pellets (v) obtained in (P1-1), 2.0 parts of vinyltrimethoxysilane and 0.2 parts of di-t-butyl peroxide were added to obtain a mixture. This mixture was kneaded using a twin-screw extruder at a barrel temperature of 210°C and a residence time of 80 to 90 seconds. The kneaded mixture was extruded and cut with a pelletizer to obtain pellets (vi) of a silane-modified hydrogenated block copolymer. A film-shaped test piece was prepared from this pellet (vi), and the glass transition temperature Tg was evaluated by the tan δ peak of a dynamic viscoelasticity measuring device, which was 124°C.

[Example 1]
100 parts of cyclohexane was mixed with 0.2 parts of an oil-soluble dye (Oil Black 860, Orient Chemical Industry Co., Ltd.), ultrasonic waves were applied for 10 minutes to dissolve the oil-soluble dye in cyclohexane, and then the mixture was filtered through a 5 μm filter to obtain a dye solution. 20 parts of a resin containing a cyclic olefin-based ring-opening polymer hydrogenated product (Zeon Corporation's "ZEONOR 1430") was added to 80 parts of the obtained dye solution and dissolved to obtain a black coating liquid containing a resin and an oil-soluble dye.

This coating liquid was applied to one side of a release PET film (HY-S10, manufactured by Higashiyama Film Co., Ltd.) using an applicator to form a coating film.

The coating film was dried in an oven at 100° C. for 10 minutes to remove the solvent, and a light-reducing film was obtained. The thickness of the obtained light-reducing film was measured by the above-mentioned method and was found to be 6 μm.
The light-reducing film was peeled off from the release PET film and the optical properties were measured. The b ^* value was -7.2, and the linear transmittance was 480 nm: 75%, 550 nm: 61%, and 610 nm: 63%. The haze was 0.1%. The light-reducing film had sufficient performance to not impair image clarity when incorporated into a display.

[Example 2]
The thickness of the coating film was changed by adjusting the applicator gap so that the thickness of the light-reducing film was 10 μm. Except for the above, the light-reducing film was obtained in the same manner as in Example 1, and the thickness and optical properties were measured in the same manner as in Example 1. The b ^* value of the light-reducing film was -10, and the linear transmittance was 480 nm: 70%, 550 nm: 51%, and 610 nm: 53%. The haze was 0.1%. The light-reducing film had a performance that did not impair image clarity when incorporated into a display.

The coating liquid was applied with an applicator onto one side of a resin film (Zeon Corporation's "ZF14 film", thickness 100 μm, made of a resin containing a hydrogenated cyclic olefin polymer and having light-transmitting properties) serving as a base layer and a thermoplastic resin layer to obtain a coating film.
The coating film was dried in an oven at 100° C. for 10 minutes to remove the solvent, and a laminate including a light-reducing film and a ZF14 film was obtained. The laminate had a configuration in which the light-reducing film was directly disposed on one side of the ZF14 film as a thermoplastic resin layer having light transparency.
The thickness of the light reducing film in the laminate was measured by the above-mentioned method and was found to be 10 μm. The haze of the obtained laminate was 0.1%, and the laminate was hardly curled.

[Example 3]
0.1 parts of an oil-soluble dye (Oil Black 860, Orient Chemical Industry Co., Ltd.) was mixed with 33 parts of toluene, and ultrasonic waves were applied for 10 minutes to dissolve the oil-soluble dye in toluene to obtain a dye solution. 10 parts of pellets (vi) of the silane-modified hydrogenated block copolymer as a resin produced in Production Example 1 were added to the obtained dye solution and dissolved, thereby obtaining a black coating liquid containing a resin and an oil-soluble dye.

This coating liquid was applied to one side of a release PET film (HY-S10, manufactured by Higashiyama Film Co., Ltd.) using an applicator to form a coating film.

The coating film was dried in an oven at 100° C. for 10 minutes to remove the solvent, and a light-reducing film was obtained. The thickness of the obtained light-reducing film was measured by the above-mentioned method and found to be 10 μm.
The light-reducing film was peeled off from the release PET film and the optical properties were measured. The b ^* value was -10, and the linear transmittance was 480 nm: 66%, 550 nm: 50%, and 610 nm: 50%. The haze was 0.1%. The light-reducing film had sufficient performance to not impair image clarity when incorporated into a display.

The coating liquid was applied with an applicator onto one side of a resin film (Zeon Corporation's "ZF14 film", 50 μm thick, made of a resin containing a hydrogenated cyclic olefin polymer and having light-transmitting properties) serving as a base layer and a thermoplastic resin layer to obtain a coating film.
The coating film was dried in an oven at 100° C. for 10 minutes to remove the solvent, and a laminate including a light-reducing film and a ZF14 film was obtained. The laminate had a configuration in which the light-reducing film was directly disposed on one side of the ZF14 film as a thermoplastic resin layer having light transparency.
The thickness of the light reducing film in the laminate was measured by the above-mentioned method and was found to be 10 μm. The haze of the obtained laminate was 0.1%, and the laminate was hardly curled.

[Example 4]
The thickness of the coating film was changed by adjusting the applicator gap so that the thickness of the light-reducing film was 15 μm. Except for the above, the light-reducing film was obtained in the same manner as in Example 1, and the thickness and optical properties were measured in the same manner as in Example 1. The b ^* value of the light-reducing film was -20, and the linear transmittance was 480 nm: 57%, 550 nm: 32%, and 610 nm: 36%. The haze was 0.1%. The light-reducing film had performance that did not impair image clarity when incorporated into a display.

The coating liquid was applied with an applicator onto one side of a resin film (Zeon Corporation's "ZF14 film", thickness 150 μm, made of a resin containing a hydrogenated cyclic olefin polymer and having light-transmitting properties) serving as a base layer and a thermoplastic resin layer to obtain a coating film.
The coating film was dried in an oven at 100° C. for 10 minutes to remove the solvent, and a laminate including a light-reducing film and a ZF14 film was obtained. The laminate had a configuration in which the light-reducing film was directly disposed on one side of the ZF14 film as a thermoplastic resin layer having light transparency.
The thickness of the light reducing film in the laminate was measured by the above-mentioned method and was found to be 10 μm. The haze of the obtained laminate was 0.1%, and the laminate was hardly curled.

[Example 5]
As the oil-soluble dye, Oil Black 803 (Orient Chemical Industry Co., Ltd.) was used instead of Oil Black 860. In addition, the thickness of the coating film was changed by adjusting the applicator gap so that the thickness of the light-reducing film was 10 μm.
A light-reduction film was obtained in the same manner as in Example 1 except for the above, and the thickness and optical properties were measured in the same manner as in Example 1. The b ^* value of the light-reduction film was -2.8, and the linear transmittance was 480 nm: 69%, 550 nm: 64%, and 610 nm: 63%. The haze was 0.1%. The light-reduction film had a performance that did not impair image clarity when incorporated into a display.

[Example 6]
As the oil-soluble dye, Oil Black HBB (Orient Chemical Industry Co., Ltd.) was used instead of Oil Black 860. In addition, the thickness of the coating film was changed by adjusting the applicator gap so that the thickness of the light-reducing film was 10 μm.
A light-reduction film was obtained in the same manner as in Example 1 except for the above, and the thickness and optical properties were measured in the same manner as in Example 1. The b ^* value of the light-reduction film was -9.8, and the linear transmittance was 480 nm: 75%, 550 nm: 61%, and 610 nm: 63%. The haze was 0.1%. The light-reduction film had a performance that did not impair image clarity when incorporated into a display.

[Comparative Example 1]
A titanium oxide dispersion was prepared by adding 0.5 parts of a dispersant "SOLSEPERSE 21000" (Nippon Lubrizol) and 95 parts of cyclohexane to 4.5 parts of titanium oxide "13M-T" (particle diameter 67 nm, manufactured by Mitsubishi Materials Corporation) and dispersing the mixture with a paint shaker.
Next, 70 parts of cyclohexane was added to 30 parts of the silane-modified hydrogenated block copolymer pellets (vi) as the resin produced in Production Example 1 to prepare a resin solution, to which 8.4 parts of a titanium oxide dispersion was added to obtain a coating liquid containing 1.3% titanium oxide particles relative to the resin.

The coating liquid containing this titanium oxide particle was applied to one side of a release PET film (HY-S10, manufactured by Higashiyama Film Co., Ltd.) using an applicator to form a coating film.

The coating film was dried in an oven at 100° C. for 10 minutes to remove the solvent, and a light-reducing film was obtained. The thickness of the obtained light-reducing film was measured by the above-mentioned method and found to be 11 μm.
The light-reducing film was peeled off from the release PET film and the optical properties were measured. The b ^* value was -4, and the linear transmittance was 480 nm: 73%, 550 nm: 71%, and 610 nm: 69%. The haze was 8%. The light-reducing film had properties that impaired image clarity when incorporated into a display.

The results are shown in the table below.
In the table below, the abbreviations have the following meanings.
"1430": "ZEONOR 1430" manufactured by Zeon Corporation
"Si-modified product": silane-modified product of the hydrogenated block copolymer produced in Production Example 1. The column for colorant concentration in the table shows the ratio (%) of the colorant (oil-soluble dye or titanium oxide particles) to the resin in the coating liquid.

From the above results, the following can be seen:
The light-reducing film of Comparative Example 1, which does not contain an oil-soluble dye, has a significantly higher haze than the light-reducing films of Examples 1 to 6.
On the other hand, the light-reducing films according to the examples had a small haze and had a performance that did not impair image clarity when incorporated into a display.

100 Laminate 110 Light-reducing film 120 Thermoplastic resin layer 120U surface 200 Laminate 210 First light-reducing film 220 Thermoplastic resin layer 220U surface 220D surface 230 Second light-reducing film

Claims (7)

Contains a resin and an oil-soluble dye,
The thickness is 1 μm or more and less than 100 μm,
A light-reducing film having a b ^* value in the CIE 1976 (L ^* , a ^* , b ^* ) color space of less than 0 , and a linear transmittance of light with a wavelength of 550 nm of 25% or more and 75% or less . The light-reducing film according to claim 1, wherein the ratio of the oil-soluble dye to the resin is 0.01% by weight or more and less than 2% by weight. The light-reducing film according to claim 1 or 2, wherein the resin contains a polymer containing an alicyclic structure. The light-reducing film according to claim 3, wherein the alicyclic structure-containing polymer is a cyclic olefin polymer or a hydrogenated product thereof. The light-reducing film according to any one of claims 1 to 4 , wherein the linear transmittance of light having a wavelength of 480 nm is greater than the linear transmittance of light having a wavelength of 610 nm. A laminate comprising the light-reducing film according to any one of claims 1 to 5 and a thermoplastic resin layer having light-transmitting properties, the light-reducing film being disposed directly on a surface of the thermoplastic resin layer. A method for producing the light-reducing film according to any one of claims 1 to 5 ,
preparing a coating liquid containing the resin, the oil-soluble dye, and a solvent;
The method includes a step of applying the coating liquid onto a surface of a base layer to form a coating film, and a step of removing the solvent from the coating film to obtain the light-reducing film.
How light-reducing film is manufactured.

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