JP2024013386A - Optical film and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film which has good color correction function and endures a long period of use, and furthermore which can be manufactured with good productivity by a roll-to-roll method.

SOLUTION: An optical film 1 is provided, comprising a sheet-like transparent substrate 20, a pigmented layer 10 formed on the transparent substrate, and a function layer 30. In the optical film 1, the pigmented layer is comprised of a die (A), an energy ray curable compound (B), a photoinitiator (C), and a radical scavenger (D). The die (A) contains at least one of a first color material, a second color material, and a third color material. When A represents the infrared absorption spectrum peak intensity at 780-825 cm^-1 of the pigmented layer, and B represents the infrared absorption spectrum peak intensity at 780-825 cm^-1 of a pentaerythritol tetraacrylate, the ratio A/B is 0.01 to 0.25 inclusive. The ultraviolet shield factor of at least one of the transparent substrate and the function layer is 85% or more when measured in conformity with JIS L1925 standard.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to an optical film. A display device using this optical film will also be mentioned.

Display devices are often used in environments where external light is incident, whether indoors or outdoors. External light incident on the display device is reflected by the surface of the display device, causing a reduction in display quality. Among these, in self-luminous display devices such as organic light emitting display devices, electrodes and many other metal wirings strongly reflect external light, and display quality tends to deteriorate.
In order to reduce the reflectance of a display device and suppress reflection of external light, a circularly polarizing plate is sometimes placed on the display surface side of the display device.

On the other hand, display devices are generally required to have high color purity. Color purity indicates the range of colors that can be displayed by a display device, and is also called color reproduction range. Therefore, high color purity means a wide color reproduction range and good color reproducibility. As means for improving color reproducibility, for example, a method of separating colors using a color filter for a white light source of a display device, and a method of correcting a monochromatic light source with a color filter to narrow the half width are known. However, color filters with improved color purity generally have low transmittance and tend to reduce luminance efficiency.

In view of the above, methods have been proposed for improving color purity without using color filters.
Patent Document 1 discloses a display filter in which a color correction layer is provided on a film having an antireflection layer and an electromagnetic wave blocking layer. Since this display filter has a structure in which a color correction layer is provided on an antireflection film, a photolithography process is not required for manufacturing, and luminance efficiency is less likely to decrease.
Patent Document 2 discloses a coloring material suitable for a color correction layer, which includes a first coloring material having a specific structure and a second coloring material having an absorption maximum in a wavelength range of 420 to 480 nm. Optical filters have been proposed that include.

Japanese Patent Application Publication No. 2007-226239 Patent No. 6142398

When forming a color correction layer on a film having an antireflection layer or the like, it is generally manufactured by a roll-to-roll method. In this case, a certain degree of surface hardness is required to prevent damage during the manufacturing process. Therefore, a cured product containing an energy ray-curable compound, such as a UV-curable material, is generally used as the binder material.

On the other hand, many of the functional dyes contained in the coloring materials used in the color correction layer cannot be said to have high light resistance. As a result of studies conducted by the present inventors, it was found that in the case of a color correction layer using a cured product containing an energy ray curable compound as a binder material, the light resistance of the functional dye is particularly likely to deteriorate. Therefore, in a display filter having such a color correction layer, the function of the functional dye deteriorates significantly with use, and there is a possibility that the color correction function cannot be fully exhibited.

In view of the above-mentioned circumstances, an object of the present invention is to provide an optical film that has a good color correction function, can withstand long-term use, and can be manufactured with high productivity by a roll-to-roll method.

A first aspect of the present invention includes a sheet-like transparent base material, a colored layer formed on the first surface side of the transparent base material, and a second surface on the opposite side to the first surface of the transparent base material. Alternatively, it is an optical film including a functional layer formed on a colored layer.
The colored layer consists of a cured product containing a dye (A), an energy ray curable compound (B), a photopolymerization initiator (C), and a radical scavenger (D).
The dye (A) contains at least one of a first coloring material, a second coloring material, and a third coloring material. The first coloring material has an absorption maximum wavelength in the range of 470 to 530 nm, and a half width of the absorption spectrum of 15 to 45 nm. The second coloring material has an absorption maximum wavelength within the range of 560 to 620 nm, and a half width of the absorption spectrum of 15 to 55 nm. The third coloring material has the lowest transmittance within the wavelength range of 380 to 780 nm within the range of 650 to 780 nm.
When the infrared absorption spectrum peak intensity at 780 to 825 cm ^-1 of the colored layer is A, and the infrared absorption spectrum peak intensity at 780 to 825 cm ^-1 of pentaerythritol tetraacrylate is B, A/B is 0.01 or more and 0.25. It is as follows.
The ultraviolet shielding rate of at least one of the transparent base material and the functional layer is 85% or more when measured according to JIS L1925.

A second aspect of the present invention is a display device including the optical film according to the first aspect.

According to the present invention, it is possible to provide an optical film that has a good color correction function, can be used for a long period of time, and can be manufactured with high productivity using a roll-to-roll method.

FIG. 1 is a cross-sectional view of an optical film according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of an optical film according to another embodiment of the present invention. FIG. 3 is a cross-sectional view of an optical film according to another embodiment of the present invention. FIG. 3 is a cross-sectional view of an optical film according to another embodiment of the present invention. FIG. 3 is a cross-sectional view of an optical film according to another embodiment of the present invention. FIG. 3 is a cross-sectional view of an optical film according to another embodiment of the present invention. It is a graph showing the spectrum of white display output through an organic EL light source and a color filter in an example. It is a graph of each spectrum at the time of red display, the time of green display, and the time of blue display output through an organic EL light source and a color filter in an example.

Embodiments of the present invention will be described below with reference to the accompanying drawings. In all the drawings, even if the embodiments are different, the same or corresponding members are denoted by the same reference numerals, and common explanations will be omitted.

[Optical film]
EMBODIMENT OF THE INVENTION Hereinafter, the optical film based on one Embodiment of this invention is demonstrated in detail based on FIG.

As shown in FIG. 1, the optical film 1 includes a colored layer 10, a transparent base material 20, and a functional layer 30. The functional layer 30 includes a low refractive index layer 31 and a hard coat layer 32. That is, the optical film 1 has a transparent base material 20 located on one side of the colored layer 10, and the colored layer 10, the transparent base material 20, the hard coat layer 32, and the low refractive index layer 31 are laminated in this order. It is a laminate made of

The thickness of the optical film 1 is, for example, preferably 10 to 140 μm, more preferably 15 to 120 μm, and even more preferably 20 to 100 μm. When the thickness of the optical film 1 is at least the above lower limit, the strength of the optical film 1 can be further increased. When the thickness of the optical film 1 is less than or equal to the above upper limit value, it is advantageous not only to make the optical film 1 more lightweight but also to make the display device thinner.
Each layer constituting the optical film 1 will be explained below.

≪Colored layer≫
The colored layer 10 is a cured product of a colored layer-forming composition containing a dye (A), an energy ray-curable compound (B), a photopolymerization initiator (C), and a radical scavenger (D). be.

The thickness of the colored layer 10 is preferably, for example, 0.5 to 10 μm. When the thickness of the colored layer 10 is equal to or greater than the above lower limit, the colored layer 10 can contain a pigment without causing any abnormality in appearance, and the light absorption properties of the pigment can improve reflection characteristics and color reproducibility. . When the thickness of the colored layer 10 is less than or equal to the above upper limit value, it is advantageous for making the display device thinner.
The thickness of the colored layer 10 is determined by observing the cross section of the optical film 1 in the thickness direction using a microscope or the like.

<Dye (A)>
The dye (A) contains at least one of the first coloring material, second coloring material, and third coloring material shown below.
The absorption maximum wavelength of the first coloring material is within the range of 470 to 530 nm, and the half width of the absorption spectrum is 15 to 45 nm. When the maximum absorption wavelength is less than the above lower limit value, it tends to reduce the luminance efficiency of blue light emission, and when it exceeds the above upper limit value, it tends to reduce the luminance efficiency of green light emission. If the half-width of the absorption spectrum is less than the above lower limit value, the effect of suppressing the reflection characteristics against external light will be small, and if it exceeds the above upper limit value, the reflection characteristics against external light will tend to improve, but the luminance efficiency will tend to decrease. .

The absorption maximum wavelength of the second coloring material is within the range of 560 to 620 nm, and the half width of the absorption spectrum is 15 to 55 nm. When the absorption maximum wavelength is less than the above lower limit value, it tends to reduce the luminance efficiency of green light emission, and when it exceeds the above upper limit value, it tends to reduce the luminance efficiency of red light emission. If the half-width of the absorption spectrum is less than the above lower limit value, the effect of suppressing the reflection characteristics against external light will be small, and if it exceeds the above upper limit value, the reflection characteristics against external light will tend to improve, but the luminance efficiency will tend to decrease. .

The third coloring material has the lowest transmittance within the wavelength range of 380 to 780 nm within the range of 650 to 780 nm. If the wavelength with the lowest transmittance in the wavelength range of 380 to 780 nm of the third coloring material is less than the above lower limit value, the luminance efficiency of red light emission will be likely to decrease, and if it exceeds the above upper limit value, it will be difficult to reflect external light. The suppressing effect on characteristics becomes smaller.

The dye (A) is a compound having any of the following: a porphyrin structure, a merocyanine structure, a phthalocyanine structure, an azo structure, a cyanine structure, a squarylium structure, a coumarin structure, a polyene structure, a quinone structure, a tetradiporphyrin structure, a pyrromethene structure, or an indigo structure; or a metal complex thereof. In particular, it is more preferable to use a metal complex having a porphyrin structure, a pyrromethene structure, or a phthalocyanine structure, or a compound having a squarylium structure because of their excellent reliability. The dye (A) may contain one kind of these compounds or metal complexes thereof, or may contain two or more kinds thereof. These compounds or metal complexes thereof may be contained in the first coloring material, in the second coloring material, in the third coloring material, or in the third coloring material. It may be included in two or more types of coloring materials.

<Energy ray curable compound (B)>
The energy ray curable compound (B) is a resin that is polymerized and cured by irradiation with active energy rays such as ultraviolet rays and electron beams. For example, monofunctional, bifunctional, trifunctional or more functional (meth)acrylate monomers, urethane (meth)acrylate, etc. can be used. Here, "(meth)acrylate" means both or one of "acrylate" and "methacrylate".

Examples of monofunctional (meth)acrylate compounds that can be included in the energy beam curable compound (B) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (meth)acrylate. ) acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, glycidyl (meth)acrylate, acryloylmorpholine, N-vinylpyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth)acrylate Acrylate, 2-ethylhexyl (meth)acrylate, isobornyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate Acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phosphoric acid (meth)acrylate, ethylene oxide modified phosphoric acid (meth)acrylate, phenoxy (meth)acrylate , ethylene oxide modified phenoxy (meth)acrylate, propylene oxide modified phenoxy (meth)acrylate, nonylphenol (meth)acrylate, ethylene oxide modified nonylphenol (meth)acrylate, propylene oxide modified nonylphenol (meth)acrylate, methoxydiethylene glycol (meth)acrylate, Methoxypolyethylene glycol (meth)acrylate, methoxypropylene glycol (meth)acrylate, 2-(meth)acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-(meth)acryloyl Oxyethyl hydrogen phthalate, 2-(meth)acryloyloxypropyl hydrogen phthalate, 2-(meth)acryloyloxypropyl hexahydrohydrogen phthalate, 2-(meth)acryloyloxypropyl tetrahydrohydrogen phthalate, dimethylaminoethyl (meth)acrylate, tri Monovalent mono(meth)acrylate derived from fluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropropyl (meth)acrylate, 2-adamantane, adamantanediol. Examples include adamantane derivative mono(meth)acrylates such as adamantyl acrylate. Here, "(meth)acryloyl" shall mean either or both of "acryloyl" and "methacryloyl."

Examples of bifunctional (meth)acrylate compounds that can be included in the energy ray-curable compound (B) include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, and hexane. Diol di(meth)acrylate, nonanediol di(meth)acrylate, ethoxylated hexanediol di(meth)acrylate, propoxylated hexanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, Tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethoxylated neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, hydroxypivalic acid neo Examples include di(meth)acrylates such as pentyl glycol di(meth)acrylate.

Examples of trifunctional or higher functional (meth)acrylate compounds that can be included in the energy beam curable compound (B) include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, and propoxylated trimethylacrylate. Tri(meth)acrylates such as methylolpropane tri(meth)acrylate, tris-2-hydroxyethyl isocyanurate tri(meth)acrylate, glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate Trifunctional (meth)acrylate compounds such as acrylate, ditrimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, etc. Trifunctional or higher functional polyfunctional (meth)acrylate compounds such as erythritol penta(meth)acrylate, ditrimethylolpropane penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, ditrimethylolpropane hexa(meth)acrylate, and these ( Examples include polyfunctional (meth)acrylate compounds in which a portion of meth)acrylate is substituted with an alkyl group or ε-caprolactone.

In addition, urethane (meth)acrylate can also be used as a resin that can be included in the energy ray curable compound (B). Examples of urethane (meth)acrylate include those obtained by reacting a (meth)acrylate monomer having a hydroxyl group with a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer. .

Examples of urethane (meth)acrylates include pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate toluene diisocyanate Examples include urethane prepolymer, pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate isophorone diisocyanate urethane prepolymer.

The other monofunctional, bifunctional, trifunctional or higher functional (meth)acrylate monomers, urethane (meth)acrylates, etc. that can be included in the energy ray curable compound (B) mentioned above may be used alone, Two or more types may be used in combination. Alternatively, it may be a partially polymerized oligomer.

The content of the energy ray-curable compound (B) is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, based on the total mass of the composition for forming a colored layer. When the content of the energy ray-curable compound (B) is at least the above lower limit, the effect of inhibiting discoloration can be further enhanced. When the content of the energy ray curable compound (B) is below the above upper limit, the handleability of the colored layer forming composition can be further improved.

<Photopolymerization initiator (C)>
For example, when ultraviolet rays are used as active energy rays, the photopolymerization initiator (C) generates radicals when irradiated with ultraviolet rays.
Examples of the photopolymerization initiator (C) include benzoins (benzoin, benzoin alkyl ethers such as benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether), phenyl ketones [e.g., acetophenones (e.g., acetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, etc.), 2- Alkylphenyl ketones such as hydroxy-2-methylpropiophenone; cycloalkylphenyl ketones such as 1-hydroxycyclohexylphenyl ketone], aminoacetophenones {2-methyl-1-[4-(methylthio)phenyl]- 2-morpholinoaminopropanone-1, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1, etc.}, anthraquinones (anthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2- t-butylanthraquinone, 1-chloroanthraquinone, etc.), thioxanthones (2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, etc.), ketals (acetophenone dimethyl ketal, benzyl dimethyl ketal, etc.), benzophenones (benzophenone, etc.), xanthones, phosphine oxides (eg, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc.), and the like. These photopolymerization initiators may be used alone or in combination of two or more.

The content of the photopolymerization initiator (C) is preferably 0.01 to 20% by mass, more preferably 0.01 to 5% by mass, based on the solid content of the composition for forming a colored layer. If the content of the photopolymerization initiator (C) is less than the above lower limit, curability will be insufficient. When the content of the photopolymerization initiator (C) exceeds the above upper limit value, unreacted photopolymerization initiator (C) remains and reliability such as heat resistance deteriorates.

<Radical scavenger (D)>
Examples of the radical scavenger (D) include resins having an amine structure. Here, the "amine structure" refers to a structure in which the hydrogen atom of ammonia is replaced with a hydrocarbon group or an aromatic atomic group. Examples of the amine structure include primary amines, secondary amines, and tertiary amines, and may also be quaternary ammonium cations.

The radical scavenger (D) has the function of capturing radicals when the dye (A) undergoes oxidative deterioration, suppressing autooxidation, and suppressing dye deterioration (fading). Examples of the resin having an amine structure that can be used as the radical scavenger (D) include resins having a hindered amine structure having a molecular weight of 2000 or more. When the molecular weight of the resin having a hindered amine structure is 2000 or more, a high fading suppressing effect can be obtained. This is considered to be because many molecules remain in the colored layer 10, and a sufficient effect of suppressing fading can be obtained.
The molecular weight of the resin having a hindered amine structure is, for example, about 200,000, but the upper limit is not particularly limited.
As used herein, "molecular weight" means "mass average molecular weight" measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

The radical scavenger (D) in this embodiment is an amine structure-containing polymer having radical scavenging ability, and includes a structural unit represented by the following formula (i).

In the above formula (i), R ¹² is a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a cyano group, a hydroxy group, an alkyl group having 10 or less carbon atoms, an alkoxycarbonyl group having 10 or less carbon atoms, or 10 or less carbon atoms. Alkylsulfonylaminocarbonyl group, arylsulfonylaminocarbonyl group, alkylsulfonyl group, arylsulfonyl group, acylaminosulfonyl group with 10 or less carbon atoms, alkoxy group with 10 or less carbon atoms, alkylthio group with 10 or less carbon atoms, 10 carbon atoms The following aryloxy groups, nitro groups, alkoxycarbonyloxy groups, aryloxycarbonyloxy groups, acyloxy groups with 10 or less carbon atoms, acyl groups with 10 or less carbon atoms, carbamoyl groups, sulfamoyl groups, aryl groups with 10 or less carbon atoms, Represents a substituted amino group, a substituted ureido group, a substituted phosphono group, or a heterocyclic group, ^R13 represents a hydrogen atom or an alkyl group having 30 or less carbon atoms, and X represents a single bond, an ester group, or a It represents an aliphatic alkyl chain, an aromatic chain, a polyethylene glycol chain, or a linking group consisting of a combination thereof, and any of them may contain a spirodioxane ring.

R ¹² is preferably a hydrogen atom, a hydroxy group, or an alkyl group having 10 or less carbon atoms. The number of carbon atoms in the alkyl group is preferably 1 to 6, more preferably 1 to 3.
R ¹³ is preferably a hydrogen atom or an alkyl group having 10 or less carbon atoms. The number of carbon atoms in the alkyl group is preferably 1 to 6, more preferably 1 to 3.
As X, a single bond or an aliphatic alkyl chain having 30 or less carbon atoms is preferable. The number of carbon atoms in the aliphatic alkyl chain is preferably 10 or less, preferably 1 to 6, and more preferably 2 to 4.

In this embodiment, the radical scavenger (D) is mainly composed of a copolymer of a structural unit represented by the above formula (i) and a copolymer component having any of the repeating units described below. Among them, the one with the highest mass %) may be used. By being a copolymer, compatibility with other components can be controlled.

Examples of repeating units include (meth)acrylate repeating units, olefin repeating units, halogen atom-containing repeating units, styrene repeating units, vinyl acetate repeating units, vinyl alcohol repeating units, and the like.

Examples of (meth)acrylate repeating units include repeating units derived from (meth)acrylate monomers having a linear or branched alkyl group in their side chains, and repeating units derived from (meth)acrylate monomers having a hydroxyl group in their side chains. etc.

Examples of repeating units derived from (meth)acrylate monomers having a linear or branched alkyl group in their side chains include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and ) Isopropyl acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate , heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, (meth)acrylic acid Decyl, Isodecyl (meth)acrylate, Undecyl (meth)acrylate, Dodecyl (meth)acrylate, Tridecyl (meth)acrylate, Tetradecyl (meth)acrylate, Myristyl (meth)acrylate, Pentadecyl (meth)acrylate , hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate. These may be used alone or in combination of two or more. Among the above, (meth)acrylate repeating units having a linear or branched alkyl group having 1 to 4 carbon atoms in the side chain can be preferably used.

Examples of repeating units derived from (meth)acrylic monomers having a hydroxyl group in the side chain include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxy (meth)acrylate. Examples include components derived from monomers such as butyl, 6-hydroxyhexyl (meth)acrylate, and hydroxyphenyl (meth)acrylate. These may be used alone or in combination of two or more.

Examples of the olefinic repeating unit include components derived from olefinic monomers such as ethylene, propylene, isoprene, and butadiene. These may be used alone or in combination of two or more.

Examples of the halogen atom-containing repeating unit include components derived from monomers such as vinyl chloride and vinylidene chloride. These may be used alone or in combination of two or more.

Examples of the styrene repeating unit include components derived from styrene monomers such as styrene, α-methylstyrene, and vinyltoluene. These may be used alone or in combination of two or more.
Examples of vinyl acetate-based repeating units include esters of vinyl alcohol and saturated carboxylic acids such as vinyl acetate and vinyl propionate. These may be used alone or in combination of two or more.
Examples of vinyl alcohol repeating units include vinyl alcohol, which may have a 1,2-glycol bond in its side chain.

The copolymer may have the structure of a random copolymer, an alternating copolymer, a block copolymer, or a graft copolymer. If the structure of the copolymer is a random copolymer, the manufacturing process and preparation with other components are easy. Therefore, random copolymers are preferred over other copolymers.

Radical polymerization can be used as a polymerization method to obtain the copolymer. Radical polymerization is preferred because industrial production is easy. Radical polymerization may be a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, or the like. It is preferable to use a solution polymerization method for radical polymerization. By using the solution polymerization method, it is easy to control the molecular weight of the copolymer.

In radical polymerization, the monomers mentioned above may be diluted with a polymerization solvent and then a polymerization initiator may be added to polymerize the monomers.
The polymerization solvent may be, for example, an ester solvent, an alcohol ether solvent, a ketone solvent, an aromatic solvent, an amide solvent, or an alcohol solvent. The ester solvent may be, for example, methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate, methyl lactate, and ethyl lactate. Examples of alcohol ether solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether, 3-methoxy-1-butanol, and 3-methoxy- It may be 3-methyl-1-butanol or the like. The ketone solvent may be, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Aromatic solvents may include, for example, benzene, toluene, and xylene. The amide solvent may be, for example, formamide and dimethylformamide. The alcoholic solvent may be, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, s-butanol, t-butanol, diacetone alcohol, and 2-methyl-2-butanol. . In addition, in the polymerization solvent mentioned above, one type may be used individually, and two or more types may be mixed and used.

Radical polymerization initiators may be, for example, peroxides and azo compounds. The peroxide may be, for example, benzoyl peroxide, t-butyl peroxyacetate, t-butyl peroxybenzoate, di-t-butyl peroxide, and the like. Azo compounds include, for example, azobisisobutyronitrile, azobisamidinopropane salt, azobiscyanovaleric acid (salt), and 2,2'-azobis[2-methyl-N-(2-hydroxyethyl) propionamide] and the like.

The amount of the radical polymerization initiator used is preferably 0.0001 parts by mass or more and 20 parts by mass or less, and 0.001 parts by mass or more and 15 parts by mass or less, when the total monomer is set to 100 parts by mass. More preferably, the amount is 0.005 parts by mass or more and 10 parts by mass or less. The radical polymerization initiator may be added to the monomer and the polymerization solvent before starting the polymerization, or may be added dropwise into the polymerization reaction system. It is preferable to drop the radical polymerization initiator into the polymerization reaction system with respect to the monomer and the polymerization solvent, since heat generation due to polymerization can be suppressed.

The reaction temperature for radical polymerization is appropriately selected depending on the type of radical polymerization initiator and polymerization solvent. The reaction temperature is preferably 60° C. or higher and 110° C. or lower from the viewpoint of ease of production and reaction controllability.

When the radical scavenger (D) is a polymer containing a structural unit represented by formula (i), the content of the structural unit represented by formula (i) constitutes the energy ray-curable compound (B). It is preferably 1 to 95 mol%, more preferably 10 to 90 mol%, based on the total molar amount of monomers. When the content of the structural unit represented by formula (i) is within the above numerical range, the light resistance and heat resistance of the dye (A) are improved and fading is easily suppressed.

The colored layer 10 may contain a solvent (E) and an additive (F). These details will be explained below.
<Solvent (E)>
The solvent (E) is necessary when forming the colored layer, and most of it disappears from the colored layer by volatilization or the like during drying after coating, but some of it remains in the colored layer, so its components will be described.
Examples of the solvent (E) include ethers, ketones, esters, cellosolves, and the like. Examples of the ethers include dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole, and phenetol. Can be mentioned. Examples of ketones include acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, and ethylcyclohexanone. Examples of the esters include ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, n-pentyl acetate, and γ-butyrolactone. Examples of cellosolves include methyl cellosolve, cellosolve (ethyl cellosolve), butyl cellosolve, and cellosolve acetate. One type of solvent (E) may be used alone, or two or more types may be used in combination.

The content of the solvent (E) is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, based on the total mass of the composition for forming a colored layer containing the above (A) to (D). When the content of the solvent (E) is at least the above lower limit, the handleability of the composition for forming a colored layer can be further improved. When the content of the solvent (E) is at most the above upper limit, the time for forming the colored layer can be shortened.

<Additive (F)>
Specific examples of additives (F) include singlet oxygen quenchers, peroxide decomposers, leveling agents, antifoaming agents, antioxidants, ultraviolet absorbers, light stabilizers, photosensitizers, conductive materials, etc. Can be mentioned.

Examples of singlet oxygen quenchers include dialkyldithiophosphates, dialkyldithiocarbanates, benzenedithiols, and transition metal complexes thereof.
When the colored layer contains a singlet oxygen quencher, the light resistance and heat resistance of the dye (A) can be improved.

The inventors investigated various configurations that would not reduce the light resistance of the functional coloring material while ensuring surface hardness that could withstand roll-to-roll manufacturing ^. We have found that this can be achieved by adjusting the infrared absorption spectrum peak intensity in a predetermined range and further containing a radical scavenger. Specifically, when the infrared absorption spectrum peak intensity at 780 to 825 cm ^-1 of the colored layer 10 is A, and the infrared absorption spectrum peak intensity at 780 to 825 cm ^-1 of pentaerythritol tetraacrylate is B, A/B is 0. By setting it to .01 or more and 0.25 or less, both surface hardness and light resistance can be made good. Details will be shown later using examples, but if the above A/B is less than 0.01, the hardness of the colored layer after curing will not be sufficient, and if it exceeds 0.25, there is a high possibility that the light resistance will not be sufficient. Ta.

Although the detailed mechanism by which the colored layer 10 according to this embodiment achieves the above effects is not completely clear, the infrared absorption spectrum peak intensity at 780 to 825 cm ⁻¹ is an indicator of the degree of double bonding. It has been known. In the colored layer 10 according to the present embodiment, a certain amount of double bonds is ensured in the structure of the colored layer to impart hardness, while suppressing the amount of double bonds from becoming excessive. While suppressing the generation of radicals that degrade functional coloring materials that are generated when light hits heavy bonds, the reduction in light resistance is also suppressed by capturing the generated radicals with a radical scavenger. it is conceivable that.

In order to adjust the value of A/B, it is effective to use a compound having only two (meth)acryloyl groups as the material used for the energy ray-curable compound (B). According to the inventors' studies, if the energy ray-curable compound (B) contains 20% by weight or more of a compound having only two (meth)acryloyl groups, the above preferred range of A/B can be easily achieved. has been found.

≪Transparent base material≫
The transparent base material 20 is a sheet-like member located on one surface of the colored layer 10 and forming the optical film 1.
As the material of the transparent base material 20, a resin film having translucency can be used. As the material for forming the transparent base material 20, transparent resin or inorganic glass can be used. Examples of the transparent resin include polyolefin, polyester, polyacrylate, polyamide, polyimide, polyarylate, polycarbonate, triacetyl cellulose, polyvinyl alcohol, polyvinyl chloride, cycloolefin copolymer, norbornene-containing resin, polyether sulfone, polysulfone, etc. Can be mentioned. Examples of the polyolefin include polyethylene and polypropylene. Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and the like. Examples of polyacrylate include polymethyl methacrylate. Examples of the polyamide include nylon 6 and nylon 66. Among these, a film made of polyethylene terephthalate (PET), a film made of triacetyl cellulose (TAC), a film made of polymethyl methacrylate (PMMA), and a film made of polyester other than PET can be suitably used.
The thickness of the transparent base material 20 is not particularly limited, but is preferably, for example, 10 to 100 μm.
The transmittance of the transparent base material 20 is preferably 90% or more, for example.

The transparent base material 20 may be provided with ultraviolet absorbing ability. By adding a UV absorber to the resin that is the raw material for the transparent base material 20, the transparent base material 20 can be given UV absorbing ability.

Examples of the ultraviolet absorber include salicylic acid ester ultraviolet absorbers, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzotriazine ultraviolet absorbers, cyanoacrylate ultraviolet absorbers, and the like.
These ultraviolet absorbers may be used alone or in combination of two or more.

When imparting ultraviolet absorption ability to the transparent base material 20, the ultraviolet shielding rate is preferably 85% or more. Here, the ultraviolet shielding rate is a value measured in accordance with JIS L1925, and is calculated by the following formula.
Ultraviolet shielding rate (%) = 100 - Average transmittance of ultraviolet light with a wavelength of 290 to 400 nm (%)
When the ultraviolet shielding rate is less than 85%, the fading suppressing effect on the light resistance of the dye (A) becomes low.

≪Functional layer≫
The functional layer 30 is located on one or the other surface of the colored layer 10. By having the functional layer 30, the optical film can exhibit various functions.
Functions of the functional layer 30 include antireflection function, antiglare function, antistatic function, antifouling function, reinforcement function, ultraviolet absorption function (ultraviolet absorption ability), and the like.
The functional layer 30 may be a single layer or may be a plurality of layers. The functional layer 30 may have one type of function, or may have two or more types of functions.

When the optical film 1 has an antireflection function, the functional layer 30 functions as an antireflection layer. Examples of the antireflection layer include a hard coat layer 32, an antiglare layer 34, and a low refractive index layer 31 having a lower refractive index than the transparent base material 20, which will be described later. The low refractive index layer 31 can be formed by using a material having a lower refractive index than the materials of the hard coat layer 32, the anti-glare layer 34, and the transparent base material 20 for the functional layer.
To adjust the refractive index of the low refractive index layer 31, lithium fluoride (LiF), magnesium fluoride (MgF ₂ ), sodium hexafluoroaluminum (cryolite, cryolite, 3NaF・AlF ₃ , Na ₃ AlF ₆ ), Fine particles such as aluminum fluoride (AlF ₃ ), fine silica particles, etc. may be blended. As the silica particles, it is effective to use particles having voids inside the particles, such as porous silica particles or hollow silica particles, to lower the refractive index of the low refractive index layer 31. In addition, the composition for forming the low refractive index layer 31 (composition for forming a low refractive index layer) contains the photopolymerization initiator (C), solvent (D), and additive (E) described in the colored layer 10. They may be blended as appropriate.
The refractive index of the low refractive index layer 31 is preferably 1.20 to 1.55.
The thickness of the low refractive index layer 31 is not particularly limited, but is preferably 40 nm to 1 μm, for example.

When the optical film 1 has an anti-glare function, the functional layer 30 functions as an anti-glare layer 34. The anti-glare layer 34 has fine irregularities on its surface, and is a layer that uses the irregularities to scatter external light, suppress reflections, and improve display quality. When combined with the low refractive index layer 31, the low refractive index layer 31 and the anti-glare layer 34 constitute an antireflection layer.
The anti-glare layer 34 contains at least one kind selected from organic fine particles and inorganic fine particles as necessary. Organic fine particles are materials that form fine irregularities on the surface and provide the function of scattering external light. Examples of organic fine particles include translucent resin materials such as acrylic resin, polystyrene resin, styrene-(meth)acrylate copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, and polyethylene fluoride resin. Examples include resin particles consisting of: In order to adjust the refractive index and the dispersibility of the resin particles, two or more types of resin particles having different materials (refractive indexes) may be mixed and used.
Inorganic fine particles are materials that adjust sedimentation and aggregation of organic fine particles. As the inorganic fine particles, for example, silica fine particles, metal oxide fine particles, various mineral fine particles, etc. can be used. As the silica fine particles, for example, colloidal silica, silica fine particles surface-modified with a reactive functional group such as a (meth)acryloyl group, etc. can be used. As the metal oxide fine particles, for example, alumina (aluminum oxide), zinc oxide, tin oxide, antimony oxide, indium oxide, titania (titanium dioxide), zirconia (zirconium dioxide), etc. can be used. Examples of mineral fine particles include mica, synthetic mica, vermiculite, montmorillonite, iron-montmorillonite, bentonite, beidellite, saponite, hectorite, stevensite, nontronite, magadiite, islarite, kanemite, layered titanate, smectite, and synthetic. Smectite etc. can be used. The mineral fine particles may be either natural products or synthetic products (including substituted products and derivatives), and a mixture of both may be used. Among the mineral fine particles, layered organic clay is more preferable. Layered organic clay refers to a swellable clay in which organic onium ions are introduced between the layers. The organic onium ion is not limited as long as it can be organicized using the cation exchange properties of the swelling clay. When using a layered organic clay mineral as the mineral fine particles, the above-mentioned synthetic smectite can be suitably used. Synthetic smectite has the function of increasing the viscosity of the coating liquid for forming the anti-glare layer, suppressing the sedimentation of resin particles and inorganic fine particles, and adjusting the uneven shape of the surface of the anti-glare layer 34 (functional layer 30). have

When the optical film 1 has an antistatic function, the functional layer 30 functions as an antistatic layer. Examples of antistatic layers include metal oxide fine particles such as antimony-doped tin oxide (ATO) and tin-doped indium oxide (ITO), polymeric conductive compositions, and quaternary ammonium salts. A layer containing an agent can be mentioned.
The antistatic layer may be provided on the outermost surface of the functional layer 30 or may be provided between the functional layer 30 and the transparent base material 20. Alternatively, an antistatic layer may be formed by adding an antistatic agent to any layer constituting the functional layer 30 described above. When an antistatic layer is provided, the surface resistance value of the optical film is preferably 1.0×10 ⁶ to 1.0×10 ¹² (Ω/cm).

When the optical film 1 has an antifouling function, the functional layer 30 functions as an antifouling layer. The antifouling layer improves antifouling properties by imparting water repellency and/or oil repellency. Examples of the antifouling layer include layers containing antifouling agents such as silicon oxide, fluorine-containing silane compounds, fluoroalkylsilazane, fluoroalkylsilanes, fluorine-containing silicon compounds, and perfluoropolyether group-containing silane coupling agents. It will be done.
The antifouling layer may be provided on the outermost surface of the functional layer 30, or the antifouling layer may be formed by adding an antifouling agent to the outermost layer of the functional layer 30 described above. .

When the optical film 1 has a reinforcing function, the functional layer 30 functions as a reinforcing layer. The reinforcing layer is a layer that increases the strength of the optical film. An example of the reinforcing layer is the hard coat layer 32. Examples of the hard coat layer 32 include a layer formed with a hard coat agent containing monofunctional, bifunctional, trifunctional or more functional (meth)acrylate, or urethane (meth)acrylate.

When the optical film 1 has ultraviolet absorption ability, the functional layer 30 functions as an ultraviolet absorption layer. As the ultraviolet absorbing layer, for example, triazine-based materials such as 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-hexyloxyphenol, 2-(2H-benzotriazole-2- Examples include a layer containing a benzotriazole-based ultraviolet absorber such as yl)-4-methylphenol.
The content of the ultraviolet absorber is preferably 0.1 to 5% by weight based on the total weight of the materials forming the ultraviolet absorbing layer. When the content of the ultraviolet absorber is at least the above lower limit, sufficient ultraviolet absorbing ability can be imparted to the functional layer 30. When the content of the ultraviolet absorber is at most the above upper limit, it is possible to avoid insufficient hardness due to a decrease in the curing component.

In the optical film 1, one or both of the transparent base material 20 and the functional layer 30 have an ultraviolet shielding rate of 85% or more, preferably 90% or more, more preferably 95% or more, and may be 100%. When the ultraviolet shielding rate is at least the above lower limit, light resistance and heat resistance can be further improved.
The ultraviolet shielding rate can be measured according to the method described in JIS L1925.
The ultraviolet shielding rate can be adjusted by imparting ultraviolet absorption ability to one or both of the transparent base material 20 and the functional layer 30.

The thickness of the functional layer 30 is, for example, preferably 0.04 to 25 μm, more preferably 0.1 to 20 μm, and even more preferably 0.2 to 15 μm. When the thickness of the functional layer 30 is equal to or greater than the above lower limit, various functions can be easily imparted to the optical film 1. When the thickness of the functional layer 30 is less than or equal to the above upper limit value, it is advantageous for making the display device thinner.

[Optical film manufacturing method]
The optical film 1 of this embodiment can be manufactured by a conventionally known method.
For example, a composition for forming a colored layer containing the above (A) to (D) (which may also contain (E) and (F)) is applied to one surface of the transparent base material 20, and active energy rays are irradiated. The colored layer 10 is obtained by curing the colored layer forming composition.
The light source for curing the colored layer forming composition by irradiating active energy rays to form the colored layer 10 can be any light source that generates active energy rays. As the active energy ray, optical energy rays such as radiation (gamma rays, X-rays, etc.), ultraviolet rays, visible light, and electron beams (EB) can be used, and usually ultraviolet rays and electron beams are used. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, an electrodeless discharge tube, etc. can be used as a lamp that emits ultraviolet rays. As for the irradiation conditions, the amount of ultraviolet irradiation is usually 100 to 1000 mJ/cm ² .

Next, a hard coat agent is applied to the other surface of the transparent base material 20, and similarly to the colored layer 10, the hard coat agent is cured by irradiation with active energy rays, thereby obtaining the hard coat layer 32.

By forming the low refractive index layer 31 on the hard coat layer 32, the optical film 1 in which the functional layer 30 is located on the other surface of the transparent base material 20 is obtained.
There are no limitations on the method of forming the low refractive index layer 31, and examples include a method of applying a composition for forming a low refractive index layer to the hard coat layer 32 and curing it by irradiating active energy rays, a vacuum evaporation method, a sputtering method, and an ion spray method. A method such as a heating method, an ion beam method, or a plasma vapor phase epitaxy method can be used.

[Other embodiments]
As shown in FIG. 2, the optical film has a transparent base material 20 located on one side of the colored layer 10, and the colored layer 10, the transparent base material 20, and the anti-glare layer 34 are laminated in this order. It may be the optical film 3. In the optical film 3, the antiglare layer 34 constitutes the functional layer 30.
Since the optical film 3 of this embodiment has the anti-glare layer 34, it is excellent in suppressing reflection.

As shown in FIG. 3, the optical film has a transparent base material 20 located on one side of the colored layer 10, and the colored layer 10, the transparent base material 20, the anti-glare layer 34, and the low refractive index layer 31, The optical film 4 may be laminated in this order. In the optical film 4, the anti-glare layer 34 and the low refractive index layer 31 constitute the functional layer 30.
Since the optical film 4 of this embodiment has the low refractive index layer 31 and the anti-glare layer 34, it is excellent in suppressing reflection.

As shown in FIG. 4, the optical film has a transparent base material 20 located on one surface of the colored layer 10 and a functional layer 30 located on the other surface of the colored layer 10. The optical film 5 may have the colored layer 10, the hard coat layer 32, and the low refractive index layer 31 laminated in this order. In the optical film 5 , the hard coat layer 32 and the low refractive index layer 31 constitute the functional layer 30 .
The optical film 5 of this embodiment has a colored layer 10 and a functional layer 30 having an ultraviolet absorbing function and an antireflection function on one side of a transparent base material 20. The ultraviolet absorption function may be imparted to any of the layers constituting the functional layer.

As shown in FIG. 5, the optical film has a transparent base material 20 located on one surface of the colored layer 10 and an anti-glare layer 34 located on the other surface of the colored layer 10. , the colored layer 10, and the anti-glare layer 34 may be laminated in this order in the optical film 7. In the optical film 7 , the antiglare layer 34 constitutes the functional layer 30 .
Since the optical film 7 of this embodiment has the anti-glare layer 34, it is excellent in suppressing reflection.
In the optical film 7, it is preferable that the anti-glare layer 34 has an ultraviolet absorbing function.

As shown in FIG. 6, the optical film has a transparent base material 20 located on one surface of the colored layer 10 and a functional layer 30 located on the other surface of the colored layer 10. The optical film 8 may have the colored layer 10, the anti-glare layer 34, and the low refractive index layer 31 laminated in this order. In the optical film 8, the anti-glare layer 34 and the low refractive index layer 31 constitute the functional layer 30.
Since the optical film 8 of this embodiment has the low refractive index layer 31 and the anti-glare layer 34, it is excellent in suppressing reflection.
In the optical film 8, it is preferable that one of the layers constituting the functional layer 30 has an ultraviolet absorption function.

[Display device]
The display device of the present invention includes the optical film of the present invention. Specific examples of display devices include televisions, monitors, mobile phones, portable game devices, personal digital assistants, personal computers, electronic books, video cameras, digital still cameras, head-mounted displays, navigation systems, and sound playback devices ( (car audio, digital audio player, etc.), copying machines, facsimile machines, printers, multifunction printers, vending machines, automatic teller machines (ATMs), personal authentication devices, optical communication devices, IC cards, etc. Among these, it is suitably used for display devices equipped with self-luminous elements such as LEDs, organic ELs, inorganic phosphors, and quantum dots, which are susceptible to reflection of external light due to metal electrodes and wiring.

According to the optical films according to the embodiments described above, the colored layer 10 after curing has sufficient hardness and can be manufactured with high productivity by a roll-to-roll method. Moreover, the light resistance and heat resistance of the coloring material contained in the colored layer can be improved, and both reflection suppression and brightness efficiency can be achieved. Therefore, the display device including the optical film of this embodiment can improve the display quality and extend the life of the light emitting elements.

Although each embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and changes and combinations of the configuration can be made without departing from the gist of the present invention. included.

For example, each of the optical films described above has one colored layer, but the number of colored layers may be two or more. In this case, each colored layer may contain the same coloring material among the first to third coloring materials, or may contain different coloring materials.
In the optical film according to each embodiment, the ultraviolet absorbing ability may be imparted to the transparent base material 20 or to the functional layer 30 such as the hard coat layer 32. What is important is that when attached to a display device, a layer closer to the screen viewed by the user than the colored layer 10 is given ultraviolet absorbing ability.

The present invention will be explained in more detail below using examples. The technical scope of the present invention is not limited in any way based solely on the specific contents of these Examples.

[Examples 1 to 7, Comparative Examples 1 to 7]
In the following Examples and Comparative Examples, optical films 1 to 22 having the layer configurations shown in Table 1 were produced. For the produced optical films 1 to 22, the optical film characteristics and the display device characteristics in an organic EL panel were evaluated by simulation. In the table, "-" indicates that the layer is not included.

≪Preparation of optical film≫
The method for forming each layer will be explained below.

[Formation of colored layer]
The following materials were used for the colored layer.
Note that the absorption maximum wavelength, half-width, and minimum transmittance wavelength in a specified wavelength range of the coloring material are characteristic values of the cured coating film.

<Dye (A)>
・First coloring material Dye-1: Pyrromethene cobalt complex dye (maximum absorption wavelength 493 nm, half width 26 nm)
<Production example of Dye-1>
Ethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate (2.5 g) was sealed in a reaction vessel and dissolved in methanol (50 mL), followed by 47% hydrobromic acid (45 g). was added and refluxed for 1 hour. By filtering the precipitated solid, 3,3',5,5'-tetramethyl-4,4'-di-ethoxycarbonyl-2,2'-dipyrromethene hydrobromide (2.6 g) was obtained. Obtained.
3,3',5,5'-tetramethyl-4,4'-di-ethoxycarbonyl-2,2'-dipyrromethene hydrobromide (0.6 g) was sealed in a reaction vessel, and methanol (5 mL) was added. , triethylamine (0.17 g), and cobalt acetate tetrahydrate (0.18 g) were added, and the mixture was refluxed for 2 hours. Dye-1 (0.42 g) was obtained by filtering the precipitated solid.
Dye-2: Pyrromethene cobalt complex dye (maximum absorption wavelength 496 nm, half width 23 nm)
<Production example of Dye-2>
In the above <Production example of Dye-1>, ethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate was replaced with 4-butyl-2-ethyl-5-formyl-1H-pyrrole-3-carboxylate. Dye-2 was synthesized using the same procedure except that methyl acid was used.
・Second coloring material Dye-3: Tetraazaporphyrin copper complex dye (manufactured by Yamada Chemical Co., Ltd., FDG-007, maximum absorption wavelength 595 nm, half-value width 22 nm)
・Third coloring material Dye-4: Phthalocyanine copper complex dye (manufactured by Yamada Chemical Co., Ltd., FDN-002, minimum transmittance wavelength in the range of 400 to 780 nm: 780 nm)
・Other coloring materials Dye-5: Dye FDG-003 (manufactured by Yamada Chemical Co., Ltd., FDG-003, maximum absorption wavelength 545 nm, half-value width 79 nm)
Note that Dye-5 is a comparison target used only in comparative examples and does not correspond to the second coloring material in the present application.

<Energy ray curable compound (B)>
・DCPA: Tricyclodecane dimethanol diacrylate ・DCPM: Tricyclodecane dimethanol dimethacrylate ・DOGA: Dioxane glycol diacrylate ・NP-A: Neopentyl glycol diacrylate ・BP-4EAL: EO adduct diacrylate of bisphenol A・PE3A: Pentaerythritol triacrylate ・PE4A: Pentaerythritol tetraacrylate ・DPHA: Dipentaerythritol hexaacrylate ・510H: Dipentaerythritol hexaacrylate hexamethylene diisocyanate urethane prepolymer (manufactured by Kyoeisha Chemical Co., Ltd., UA-510H)
・PMMA: Methyl methacrylate polymer (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.)
Although PMMA is not an active energy ray-curable resin, it is also included in this column because it is used only in comparative examples for comparison.

<Photopolymerization initiator (C)>
・Omnirad TPO: Acyl phosphine oxide photopolymerization initiator (manufactured by IGM Resins B.V.)

<Radical scavenger (D)>
・LA-63P: Hindered amine light stabilizer Adekastab LA-63P (manufactured by Adeka Co., Ltd.)
・Resin 1: Polymer containing the structural unit represented by the above formula (i) <Production example of resin 1>
2.4 g of 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (manufactured by Showa Denko Materials Co., Ltd., FA-711MM), 5.6 g of methyl methacrylate (manufactured by Kanto Chemical Co., Ltd.), 31 g of cyclohexanone (manufactured by Kanto Kagaku Co., Ltd.) and 0.11 g of 2,2'-azobis(isobutyronitrile) (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) were placed in a reaction vessel and heated at 70°C under a nitrogen gas atmosphere. The mixture was heated and stirred for 8 hours. Thereafter, a polymer solution was obtained by heating and stirring at 100° C. for 1 hour. By pouring this polymer solution into 400 mL of methanol (manufactured by Kanto Kagaku Co., Ltd.), the resulting precipitate was filtered and dried. Resin 1 copolymerized with methyl = 15:85 [mol%] was obtained.

By additionally heating and stirring at 100°C for 1 hour, the initiator 2,2'-azobis(isobutyronitrile) can be completely decomposed, suppressing the deterioration of the optical film due to the remaining initiator. be able to.
Furthermore, by pouring the polymer solution into methanol, unreacted monomers, polymerization solvents, decomposed products of the initiator, etc. can be removed, and deterioration of the optical film can be suppressed.

<Solvent (E)>
・MEK: Methyl ethyl ketone.
・Methyl acetate

<Additive (F)>
- Compound A: T1477 having a structure represented by the following formula (ii). Note that R ¹ in the structural formula is C ₃ H ₇ , and R ² to R ⁸ are H.
・Singlet oxygen quencher: Bis(dibutyldithiocarbamic acid) nickel(II) (manufactured by Tokyo Chemical Industry Co., Ltd. D1781)

(transparent base material)
As the transparent base material, the following was used.
- TAC: triacetyl cellulose film (manufactured by Fuji Film Corporation, TG60UL, base material thickness 60 μm, ultraviolet shielding rate 92.9%).

(Formation of colored layer)
A colored layer forming composition having the composition shown in Table 2 was applied onto the transparent substrate shown in Table 1, and dried in an oven at 80° C. for 60 seconds. After that, the coating film was cured by irradiating ultraviolet rays with an irradiation dose of 150 mJ/cm ² (manufactured by Fusion UV Systems Japan Co., Ltd., light source H bulb) using an ultraviolet irradiation device, and the film thickness after curing was 5.0 μm. A colored layer was formed so that Note that the amount added is a mass ratio (mass%). In the table, "-" indicates that the component is not contained.

[Formation of functional layer: hard coat layer]
(Materials used for composition for forming hard coat layer)
The following materials were used for the hard coat layer forming composition used to form the hard coat layer.
・Active energy ray curable resin UA-306H: Pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer (manufactured by Kyoeisha Chemical Co., Ltd., UA-306H)
D.P.H.A.
PE3A: Pentaerythritol triacrylate (light acrylate PE-3A manufactured by Kyoeisha Chemical Co., Ltd.)
・Photopolymerization initiator Omnirad TPO
・Additives (ultraviolet (UV) absorbers)
Tinuvin479: Hydroxyphenyltriazine ultraviolet absorber, Tinuvin (registered trademark) 479 (manufactured by BASF Japan Ltd.)
LA-36: Benzotriazole ultraviolet absorber, Adekastab (registered trademark) LA-36 (manufactured by Adeka Co., Ltd.)
- Solvent MEK: Methyl ethyl ketone Methyl acetate Using these, two types of hard coat layer coating liquids shown in Table 3 were prepared.

(Formation of hard coat layer)
The above-mentioned hard coat layer coating liquid was applied onto the transparent substrate or colored layer shown in Table 1, and dried in an oven at 80° C. for 60 seconds. After that, the coating film was cured by irradiating ultraviolet rays with an irradiation dose of 150 mJ/cm ² (manufactured by Fusion UV Systems Japan Co., Ltd., light source H bulb) using an ultraviolet irradiation device, and the film thickness after curing was 5.0 μm. A hard coat layer was formed so that Hard coat layer 1 does not have ultraviolet absorption ability, and hard coat layer 2 has ultraviolet absorption ability.

[Formation of functional layer: anti-glare layer]
(Materials used for anti-glare layer forming composition)
The following materials were used for the anti-glare layer forming composition used to form the anti-glare layer.
・Active energy ray curable resin PE3A
・Photopolymerization initiator Omnirad TPO
・Resin particles Styrene-methyl methacrylate copolymer particles (refractive index 1.515, average particle size 2.0 μm)
・Inorganic fine particles Synthetic smectite Alumina nanoparticles (average particle size 40 nm)
・Additives (ultraviolet (UV) absorbers)
Tinuvin479
LA-36
- Solvent Toluene Isopropyl alcohol Using these, anti-glare layer coating liquids 1 and 2 having the following compositions were prepared.
・Coating liquid 1 for anti-glare layer
- PE3A 43.7 parts by weight - Omnirad TPO 4.55 parts by weight - Styrene-methyl methacrylate copolymer particles 0.5 parts by weight - Synthetic smectite 0.25 parts by weight - Alumina nanoparticles 1.0 parts by weight - Toluene/ Isopropyl alcohol = 30/70 50 parts by mass / Anti-glare layer coating liquid 2
- PE3A 40.5 parts by weight - Omnirad TPO 4.55 parts by weight - Styrene-methyl methacrylate copolymer particles 0.5 parts by weight - Synthetic smectite 0.25 parts by weight - Alumina nanoparticles 1.0 parts by weight - Tinuvin479/ LA-36 = 40/60 3.2 parts by mass Toluene/isopropyl alcohol = 30/70 50 parts by mass (formation of anti-glare layer)
One of the above anti-glare layer coating liquids was applied onto the transparent substrate shown in Table 1, and dried in an oven at 80°C for 60 seconds. After that, the coating film was cured by irradiating ultraviolet rays with an irradiation dose of 150 mJ/cm ² (manufactured by Fusion UV Systems Japan Co., Ltd., light source H bulb) using an ultraviolet irradiation device, and the film thickness after curing was 5.0 μm. Antiglare layer 1 or 2 was formed so as to have the following properties. The anti-glare layer 1 does not have an ability to absorb ultraviolet rays, and the anti-glare layer 2 has an ability to absorb ultraviolet rays.

[Formation of functional layer: low refractive index layer]
(Composition for forming low refractive index layer)
The following composition was used for forming the low refractive index layer.
・Refractive index adjuster Porous silica fine particles (average particle size 75 nm, solid content 20%) Methyl isobutyl ketone dispersion 8.5 parts by mass ・Antifouling agent Optool (registered trademark) AR-110 (manufactured by Daikin Industries, Ltd.) , solid content 15%, solvent: methyl isobutyl ketone) 5.6 parts by mass Active energy ray curable resin PE-3A 0.4 parts by mass Photopolymerization initiator Omnirad TPO 0.07 parts by mass Leveling agent RS-77 (Manufactured by DIC Corporation) 1.7 parts by mass/Solvent Methyl isobutyl ketone 83.73 parts by mass

(Formation of low refractive index layer)
The above composition for forming a low refractive index layer was applied onto the hard coat layer or antiglare layer shown in Table 1, and dried in an oven at 80° C. for 60 seconds. After that, the coating film is cured by irradiating ultraviolet rays with an irradiation dose of 200 mJ/cm ² (manufactured by Fusion UV Systems Japan Co., Ltd., light source H bulb) using an ultraviolet irradiation device, and the film thickness after curing is 100 nm. A low refractive index layer was formed.

[Film characteristic evaluation]
<Infrared absorption spectrum measurement>
The infrared absorption spectra of the colored layers of each example were measured by the ATR method using FT-IR6300 manufactured by JASCO Corporation. In addition, the infrared absorption spectrum of PE4A was measured in the same manner. The maximum peak height of absorbance within the range of 780 cm to 825 cm ⁻¹ was determined from each spectrum. The spectrum of each sample was measured 10 times, the maximum peak height was determined for each, and the average value was taken as the peak intensity value of that sample. A/B was calculated by setting the peak intensity of the colored layer as A and the peak intensity of PE4A as B.

<Ultraviolet shielding rate on colored layer>
When a transparent base material was used as a layer above the colored layer, the transmittance of the base material was measured using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4100). If the colored layer is above the base material, peel off the layer above the colored layer using a transparent pressure-sensitive adhesive tape compliant with JIS-K5600-5-6:1999 adhesion test, and use an automatic spectrophotometer (U -4100), and the transmittance of the upper layer of the colored layer was measured using the adhesive tape as a reference. Using these transmittances, calculate the average transmittance [%] in the ultraviolet region (290 nm to 400 nm), and calculate the UV shielding rate [%] from 100% to the average transmittance [%] in the ultraviolet region (290 nm to 400 nm). Calculated as the value subtracted by

<Pencil hardness test>
The pencil hardness test is conducted in accordance with JIS-K5400-1990 using a pencil (UNI manufactured by Mitsubishi Pencil Co., Ltd., Pencil Hardness H) with a load of 500 g applied using a Clemens scratch hardness tester (manufactured by Tester Sangyo Co., Ltd., HA). -301) on the surface of the colored layer in each example. Changes in appearance due to scratches were visually evaluated, and cases in which no scratches were observed were graded as "○ (pass)" and cases in which scratches were observed were graded as "x (fail)".

<Light resistance test>
As a light resistance test of the obtained optical film, a xenon weather meter tester (manufactured by Suga Test Instruments Co., Ltd., X75) was used, and the xenon lamp illuminance was 60W/m ² (300nm to 400nm), the temperature inside the tester was 45°C, and the humidity was 50°C. The test was conducted under %RH conditions for 120 hours, and the transmittance was measured using an automatic spectrophotometer (U-4100) before and after the test. The transmittance difference ΔT before and after the test at the wavelength λ showing the minimum transmittance within the maximum absorption wavelength range of the first to third coloring materials was calculated. The evaluation was made in the following three stages, and anything other than × was considered a pass.
◎ (good): ΔT is less than 3% ○ (fair): ΔT is 3% or more and less than 4.5% × (bad): ΔT is 4.5% or more

[Display device characteristics evaluation]
<White display transmission characteristics>
The transmittance of the obtained optical film was measured using an automatic spectrophotometer (U-4100), and the efficiency of light transmitted through the optical film during white display was calculated using this transmittance. It was evaluated as a characteristic. As a reference, the efficiency of the spectrum at the time of white display output through the white organic EL light source and color filter having the spectrum shown in FIG. 7 was set as 100. The closer it is to 100, the higher the white display transmittance and the better the luminance efficiency.
<Display device reflection characteristics>
The transmittance T (λ) and surface reflectance R2 (λ) of the obtained optical film were measured using an automatic spectrophotometer (U-4100). For the measurement of surface reflectance R2 (λ), a matte black dye is applied to the surface of the transparent substrate on which the colored layer and functional layer are not formed to prevent reflection, and the spectral reflectance at an incident angle of 5° is measured. was measured and defined as the surface reflectance R2(λ). The electrode reflectance R _E (λ) is assumed to be 100% from wavelength 380 nm to 780 nm, interface reflection and surface reflection in each layer are not considered, and the D65 light source (CIE (Commission Internationale de l'Eclairage) standard) without an optical film is used. The relative reflection value when the display device reflection value for light source D65) is set to 100 is calculated based on the following formulas (1) to (4), and the surface reflectance R (λ) of the outermost layer on the observer side is calculated as the display device reflection value. It was evaluated as a characteristic. The lower the value of the display device reflection characteristics, the more the reflection of external light can be reduced and the better the reflection characteristics are. In equations (1) to (4), R1 (λ) is the internal reflection component, Y is one of the tristimulus values at the white point of the D65 light source, and P _D65 (λ) is the spectrum of the D65 light source. , and the overline y(λ) represents the CIE1931 color matching function, respectively.

＜色再現性＞
得られた光学フィルムの透過率を、自動分光光度計（Ｕ－４１００）を用いて測定し、図７に示すスペクトルの、白色ＥＬ光源とカラーフィルタを通して出力される図８の赤色表示、緑色表示、青色表示スペクトルを測定した。図７および図８のグラフの縦軸は、発光強度［ａ．ｕ．］（任意単位：ａｒｂｉｔｒａｒｙ ｕｎｉｔ）を表す。測定した透過率と図８の赤色表示、緑色表示、青色表示スペクトルとを用いて算出されるＣＩＥ１９３１色度値からＮＴＳＣ（全米テレビジョン放送方式標準化委員会）比を算出し、ＮＴＳＣ比を色再現性の指標として評価した。ＮＴＳＣ比が高いほど色再現性に優れる。

<Color reproducibility>
The transmittance of the obtained optical film was measured using an automatic spectrophotometer (U-4100), and the spectrum shown in Fig. 7 was outputted through a white EL light source and a color filter, and the red display and green display in Fig. 8 were measured. , the blue display spectrum was measured. The vertical axis of the graphs in FIGS. 7 and 8 indicates the emission intensity [a. u. ] (arbitrary unit). The NTSC (National Television Broadcast Standards Committee) ratio is calculated from the CIE1931 chromaticity value calculated using the measured transmittance and the red display, green display, and blue display spectra in Figure 8, and the NTSC ratio is used for color reproduction. It was evaluated as an index of gender. The higher the NTSC ratio, the better the color reproducibility.

The results are shown in Table 4. The results of the display device characteristic evaluation were conducted only for some examples, and the ratios of the white display transmission characteristics and display device reflection characteristics are also shown based on Comparative Example 8, which does not include a colored layer (100%). ing.

The optical films according to Examples all have A/B of 0.01 or more and 0.25 or less, exhibit good light resistance, and have sufficient hardness.
Comparative Examples 1 to 6 with A/B greater than 0.25 had insufficient light resistance, and Comparative Example 7 with A/B less than 0.01 had insufficient hardness. Furthermore, in Comparative Example 8, which did not have a colored layer, and Comparative Example 9, which did not contain any of the first to third coloring materials, the color reproducibility was insufficient.

Although one embodiment and an example of the present invention have been described in detail above, the present invention is not limited to a specific embodiment, and includes modifications and combinations of configurations within a range that does not depart from the gist of the present invention.

1, 3, 4, 5, 7, 8 Optical film 10 Colored layer 20 Transparent base material 30 Functional layer 31 Low refractive index layer 32 Hard coat layer 34 Anti-glare layer

Claims (9)

A sheet-like transparent base material,
a colored layer formed on the first surface side of the transparent base material;
In the transparent base material, a functional layer formed on a second surface opposite to the first surface or on the colored layer;
Equipped with
The colored layer is made of a cured product containing a dye (A), an energy ray curable compound (B), a photopolymerization initiator (C), and a radical scavenger (D),
The dye (A) contains at least one of a first coloring material, a second coloring material, and a third coloring material,
The first coloring material has an absorption maximum wavelength in the range of 470 to 530 nm, and a half width of the absorption spectrum of 15 to 45 nm,
The second coloring material has an absorption maximum wavelength in the range of 560 to 620 nm, and a half width of the absorption spectrum of 15 to 55 nm,
The third coloring material has a wavelength having the lowest transmittance within a wavelength range of 380 to 780 nm, and is within a range of 650 to 780 nm;
When the infrared absorption spectrum peak intensity at 780 to 825 cm ^-1 of the colored layer is A, and the infrared absorption spectrum peak intensity at 780 to 825 cm ^-1 of pentaerythritol tetraacrylate is B, A/B is 0.01 or more. 25 or less,
The ultraviolet shielding rate of at least one of the transparent base material and the functional layer is 85% or more when measured according to JIS L1925.
optical film. The energy ray curable compound (B) contains 20% by weight or more of a compound having only two (meth)acryloyl groups,
The optical film according to claim 1. The radical scavenger (D) is a polymer containing a structural unit represented by the following formula (i),
The optical film according to claim 1.

[In formula (i), R ¹² is a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a cyano group, a hydroxy group, an alkyl group having 10 or less carbon atoms, an alkoxycarbonyl group having 10 or less carbon atoms, or a 10 or less carbon atoms Alkylsulfonylaminocarbonyl group, arylsulfonylaminocarbonyl group, alkylsulfonyl group, arylsulfonyl group, acylaminosulfonyl group with 10 or less carbon atoms, alkoxy group with 10 or less carbon atoms, alkylthio group with 10 or less carbon atoms, 10 carbon atoms The following aryloxy groups, nitro groups, alkoxycarbonyloxy groups, aryloxycarbonyloxy groups, acyloxy groups with 10 or less carbon atoms, acyl groups with 10 or less carbon atoms, carbamoyl groups, sulfamoyl groups, aryl groups with 10 or less carbon atoms, Represents a substituted amino group, a substituted ureido group, a substituted phosphono group, or a heterocyclic group, ^R13 represents a hydrogen atom or an alkyl group having 30 or less carbon atoms, and X represents a single bond, an ester group, or a It represents an aliphatic alkyl chain, an aromatic chain, a polyethylene glycol chain, or a linking group consisting of a combination thereof, and any of them can contain a spirodioxane ring. ] The functional layer functions as at least one of an antireflection layer and an antiglare layer.
The optical film according to claim 1. The functional layer includes an antistatic layer or an antifouling layer.
The optical film according to claim 1. The colored layer has at least one of a singlet oxygen quencher and a peroxide decomposer,
The optical film according to claim 1. The singlet oxygen quencher is any of dialkyldithiophosphates, dialkyldithiocarbanates, benzenedithiols, and transition metal complexes thereof,
The optical film according to claim 6. A compound in which the dye (A) has any one of a porphyrin structure, a merocyanine structure, a phthalocyanine structure, an azo structure, a cyanine structure, a squarylium structure, a coumarin structure, a polyene structure, a quinone structure, a tetradiporphyrin structure, a pyrromethene structure, and an indigo structure. and one or more compounds selected from the group consisting of metal complexes thereof.
The optical film according to claim 1. comprising the optical film according to claim 1;
Display device.

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