Optical film and display device

Abstract

An optical film provided with a sheet-like transparent substrate, and a colored layer and a functional layer formed on the transparent substrate, in which the colored layer is formed from a cured product containing a dye (A), an energy ray-curable compound (B), a photopolymerization initiator (C), and a radical scavenger (D). The pigment (A) contains at least one of a first pigment, a second pigment, and a third pigment. When the infrared absorption spectrum peak intensity at 780-825 cm <-1 > of the colored layer is A and the infrared absorption spectrum peak intensity at 780-825 cm <-1 > of the pentaerythritol tetraacrylate is B, A / B is 0.01-0.25 inclusive. The ultraviolet shielding rate of at least one of the transparent substrate and the functional layer is 85% or more as measured in accordance with JIS L1925.

Description

Technical Field

[0001] The present invention relates to an optical film and a display device using the optical film.

[0002] This application claims priority based on Japanese Patent Application No. 2022-115440 filed in Japan on July 20, 2022, and Japanese Patent Application No. 2022-115441 filed in Japan on July 20, 2022, the contents of which are cited herein. Background Art

[0003] 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 at the surface of the display device, causing a reduction in display quality. In particular, electrodes and other multiple metal wirings of self-luminous display devices such as organic light-emitting display devices strongly reflect external light, which easily reduces display quality.

[0004] In order to reduce the reflectivity of a display device and suppress reflection of external light, a circular polarizing plate may be disposed on the display surface side of the display device.

[0005] On the other hand, high color purity is generally required for display devices. Color purity indicates the breadth of colors that a display device can display, and is also called the color reproduction range. Therefore, high color purity means a wide color reproduction range and good color reproducibility. As a means of improving color reproducibility, for example, it is known to use a color filter to perform color separation on the white light source of a display device, and to use a color filter to correct a monochromatic light source to narrow the half-peak width. However, color filters that improve color purity generally have a low transmittance and are prone to reducing brightness efficiency.

[0006] In view of the above circumstances, a method of improving color purity without using a color filter has been proposed.

[0007] Patent Document 1 discloses a display filter having a color correction layer on a film having an antireflection layer and an electromagnetic wave blocking layer. Since the display filter has a color correction layer on an antireflection film, a photolithography process is not required during manufacture, and the brightness efficiency is unlikely to decrease.

[0008] Patent Document 2 discloses a color material suitable for a color correction layer and proposes an optical filter including a first color material having a specific structure and a second color material having a maximum absorption in a wavelength range of 420 to 480 nm.

[0009] Although self-luminous display devices such as organic light-emitting display devices sometimes strongly reflect external light and the display quality is easily reduced, they are excellent in miniaturization and have high-quality characteristics such as low power consumption, high brightness, and high response speed, and are therefore expected to be the next generation of display devices.

[0010] In order to solve the problem of reduced display quality due to external light reflection, there is also a configuration in which a polarizing plate and a phase retardation plate are arranged on the display surface side to suppress external light reflection.

[0011] However, in the method using a polarizing plate and a phase delay plate, when the light emitted from the display device is released to the outside through the polarizing plate and the phase delay plate, a considerable portion of it is also lost at the same time, which is likely to lead to a reduction in the life of the element.

[0012] Patent document 3 proposes an organic light-emitting display device, which includes a display substrate including an organic light-emitting element and a sealing substrate disposed apart from the display substrate, and a filler that selectively absorbs external light in each wavelength band to adjust the transmittance is buried in the space between the display substrate and the sealing substrate. According to the invention of patent document 3, while suppressing the reflection of external light to improve visibility, the light of the wavelength band that particularly reduces the color purity in the light emitted from the display device is selectively absorbed, thereby also achieving an improvement in color purity.

[0013] Regarding the improvement of color purity, Patent Document 4 discloses a structure containing a pigment having a maximum absorption wavelength in at least each of the wavelength regions of 480 to 510 nm and 580 to 610 nm.

[0014] Prior art literature

[0015] Patent Literature

[0016] Patent Document 1: Japanese Patent Application Publication No. 2007-226239

[0017] Patent Document 2: Japanese Patent No. 6142398

[0018] Patent Document 3: Japanese Patent No. 5673713

[0019] Patent Document 4: Japanese Patent Application Publication No. 2019-56865

[0020] Patent Document 5: International Publication No. 2021 / 066082 Summary of the invention

[0021] Technical problem to be solved by the invention

[0022] When a color correction layer is formed on a film having an anti-reflection layer, it is usually manufactured by a roll-to-roll method. In this case, a certain degree of surface hardness is required to prevent scratches during the manufacturing process. Therefore, generally speaking, a cured product containing an energy ray curing compound such as a UV curing material is used as an adhesive material.

[0023] On the other hand, the functional pigments contained in the colorant used in the color correction layer are mostly those with low light resistance. The results of the present inventors' research have found that when the color correction layer of the cured product containing the energy ray curing type compound is used as the adhesive material, the light resistance of the functional pigment is particularly easy to reduce. Therefore, the display filter with this color correction layer has a significantly reduced function of the functional pigment as it is used, and it is possible that the color correction function cannot be fully exerted.

[0024] Furthermore, many wavelength selective absorption dyes have low light resistance and heat resistance, and the function of the dye may decrease over time, and the color purity improvement effect may not be fully exerted.

[0025] Regarding this problem, Patent Document 5 discloses a structure in which a predetermined compound is added as an anti-fading agent and a gas barrier layer is provided. However, the provision of the gas barrier layer leads to a thicker film, an increase in cost, and there is a possibility that the pigment may deteriorate from defective portions of the gas barrier layer. Furthermore, the inventors have confirmed the following phenomenon in their research: when only the anti-fading agent is added without providing a gas barrier layer, although light resistance is improved, heat resistance is reduced.

[0026] Based on the above facts, an object of the present invention is to provide an optical film and a display device that can withstand long-term use.

[0027] Another object of the present invention is to provide an optical film and a display device that have excellent color correction function, can withstand long-term use, and can be manufactured with good productivity by a roll-to-roll method.

[0028] Another object of the present invention is to provide an optical film and a display device that do not require a gas barrier layer and can maintain high display quality even when used for a long time.

[0029] Means for solving technical problems

[0030] The present invention has the following aspects.

[0031] [1] An optical film comprising:

[0032] A sheet-like transparent substrate;

[0033] a colored layer formed on the first surface side of the transparent substrate; and

[0034] A functional layer formed on the second surface of the transparent substrate opposite to the first surface or on the colored layer, wherein:

[0035] The coloring layer is formed of a cured product containing a pigment (A), an energy ray curable compound (B), a photopolymerization initiator (C), and a radical scavenger (D).

[0036] The pigment (A) contains at least one of a first colorant, a second colorant, and a third colorant.

[0037] The maximum absorption wavelength of the first colorant is within the range of 470 to 530 nm, and the half-peak width of the absorption spectrum is 15 to 45 nm.

[0038] The maximum absorption wavelength of the second colorant is within the range of 560 to 620 nm, and the half-peak width of the absorption spectrum is 15 to 55 nm.

[0039] The wavelength at which the third colorant has the lowest transmittance within the wavelength range of 380 to 780 nm is within the range of 650 to 780 nm.

[0040] The ultraviolet shielding rate of at least one of the transparent substrate and the functional layer is 85% or more when measured in accordance with JIS L1925,

[0041] The optical film satisfies at least one of the following (1) or (2),

[0042] (1) The 780-825 cm -1 The infrared absorption spectrum peak intensity of A and pentaerythritol tetraacrylate is 780-825 cm -1 When the peak intensity of the infrared absorption spectrum of is set to B, A / B is greater than or equal to 0.01 and less than or equal to 0.25,

[0043] (2) When using an illumination of 60W / cm 2 In a light resistance test conducted by irradiating the color layer from the color layer side for 120 hours under the conditions of a xenon lamp (300 to 400 nm) with an internal temperature of 45°C and a humidity of 50% RH, the following formula 1B is satisfied:

[0044] A2×(B2 / C)-D≤0.018(1B)

[0045] [In the above formula (1B), A2 is the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer after the above light resistance test is irradiated with infrared light, with the wavelength connected to 3800 cm -1 and 2400cm -1 The absorbance line at 3450cm is used as the baseline. -1 The infrared absorption spectrum peak intensity of the color layer surface before the light resistance test is obtained by splitting the reflected light when the infrared light is irradiated on the surface of the color layer. -1 and 1815cm -1 The absorbance line at 1650cm is used as the baseline. -1 and 1815cm -1C is the maximum absorption peak intensity of the infrared absorption spectrum within the range of 1650cm; C is the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer after the light resistance test is irradiated with infrared light, with the peak connecting 1650cm -1 and 1815cm -1 The absorbance line at 1650cm is used as the baseline. -1 and 1815cm -1 D is the maximum absorption peak intensity of the infrared absorption spectrum within the range of 3800cm; D is the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer before the light resistance test is irradiated with infrared light, with the wavelength connecting 3800cm -1 and 2400cm -1 The absorbance line at 3450cm is used as the baseline. -1 The peak intensity of infrared absorption spectrum.]

[0046] [2] The optical film according to [1], wherein the energy ray curable compound (B) contains 20% by weight or more of a compound having only two (meth)acryloyl groups.

[0047] [3] The optical film according to [1] or [2], wherein the radical scavenger (D) is a polymer containing a structural unit represented by the following formula (i).

[0048] [Chemical structure 1]

[0049]

[0050] [In formula (i), R 12 represents a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a cyano group, a hydroxyl group, an alkyl group having 10 or less carbon atoms, an alkoxycarbonyl group having 10 or less carbon atoms, an alkylsulfonylaminocarbonyl group having 10 or less carbon atoms, an arylsulfonylaminocarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an acylaminosulfonyl group having 10 or less carbon atoms, an alkoxy group having 10 or less carbon atoms, an alkylthio group having 10 or less carbon atoms, an aryloxy group having 10 or less carbon atoms, a nitro group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an acyloxy group having 10 or less carbon atoms, an acyl group having 10 or less carbon atoms, a carbamoyl group, an aminosulfonyl group, an aryl group having 10 or less carbon atoms, a substituted amino group, a substituted ureido group, a substituted phosphono group, or a heterocyclic group, and R 13 represents a hydrogen atom or an alkyl group having 30 or less carbon atoms, and X represents a single bond, an ester group, an aliphatic alkyl chain having 30 or less carbon atoms, an aromatic chain, a polyethylene glycol chain, or a connecting group formed by combining them, and all of them may contain a spirodioxane ring.]

[0051] [4] The optical film according to any one of [1] to [3], wherein the functional layer functions as at least one of an antireflection layer and an antiglare layer.

[0052] [5] The optical film according to any one of [1] to [4], comprising an antistatic layer or an antifouling layer as the functional layer.

[0053] [6] An optical film according to any one of [1] to [5], wherein the pigment (A) comprises one or more compounds having any structure selected from a porphyrin structure, a cyanine structure, a phthalocyanine structure, an azo structure, a cyanine structure, a squarylium structure, a coumarin structure, a polyene structure, a quinone structure, a tetrazaporphyrin structure, a pyrromethene structure and an indigo structure, and their metal complexes.

[0054] [7] The optical film according to any one of [1] to [6], which satisfies the above-mentioned (1), and the colored layer contains at least one of a singlet oxygen quencher and a peroxide decomposer.

[0055] [8] The optical film according to [7], which satisfies the above (1), wherein the singlet oxygen quencher is any one of dialkyl dithiophosphates, dialkyl dithiocarbamates, benzenedithiol, and transition metal complexes thereof.

[0056] [9] An optical film according to any one of [1] to [6], which satisfies the above-mentioned (2), and the above-mentioned color layer contains any one of dialkyl dithiophosphate, dialkyl dithiocarbamate, benzenedithiol and their transition metal complexes, and a compound represented by the following formula (ii).

[0057] [Chemical structure 2]

[0058]

[0059] [In the above formula (ii), R 1 Each independently represents an alkyl group, an alkenyl group, an aryl group, a heterocyclic group or R 9 CO - , R 10 SO2 - or R 11 NHCO - The group shown, R 9 , R 10 and R 11 Each independently represents an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. 2 and R 3 Each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group or an alkenyloxy group, and R 4 ~R 8Each independently represents a hydrogen atom, an alkyl group, an alkenyl group or an aryl group.]

[0060]

[10] The optical film according to any one of [1] to [6] and [9], which satisfies the above-mentioned (2), and the pencil hardness of the surface of the above-mentioned colored layer under a load of 500 g is H or more.

[0061]

[11] A display device comprising the optical film according to any one of [1] to

[10] .

[0062] As one aspect, the present invention has the following aspects.

[0063] [A1] An optical film comprising:

[0064] A sheet-like transparent substrate;

[0065] a colored layer formed on the first surface side of the transparent substrate; and

[0066] The functional layer is formed on the second surface opposite to the first surface of the transparent substrate or on the colored layer.

[0067] The colored layer is formed of a cured product containing a dye (A), an energy ray curable compound (B), a photopolymerization initiator (C), and a radical scavenger (D).

[0068] The pigment (A) contains at least one of a first pigment, a second pigment, and a third pigment. The maximum absorption wavelength of the first pigment is within the range of 470 to 530 nm, and the half-peak width of the absorption spectrum is 15 to 45 nm. The maximum absorption wavelength of the second pigment is within the range of 560 to 620 nm, and the half-peak width of the absorption spectrum is 15 to 55 nm. The wavelength at which the third pigment has the lowest transmittance within the wavelength range of 380 to 780 nm is within the range of 650 to 780 nm.

[0069] The coloring layer is 780~825cm -1 The infrared absorption spectrum peak intensity of A and pentaerythritol tetraacrylate is 780-825 cm -1 When the peak intensity of the infrared absorption spectrum of is defined as B, A / B is greater than or equal to 0.01 and less than or equal to 0.25.

[0070] The ultraviolet shielding rate of at least one of the transparent substrate and the functional layer is 85% or more when measured in accordance with JIS L1925.

[0071] [A2] The optical film according to [A1], wherein the energy ray curable compound (B) contains 20% by weight or more of a compound having only two (meth)acryloyl groups.

[0072] [A3] The optical film according to [A1] or [A2], wherein the radical scavenger (D) is a polymer containing a structural unit represented by the following formula (i).

[0073] [Chemical structure 3]

[0074]

[0075] [In formula (i), R 12 represents a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a cyano group, a hydroxyl group, an alkyl group having 10 or less carbon atoms, an alkoxycarbonyl group having 10 or less carbon atoms, an alkylsulfonylaminocarbonyl group having 10 or less carbon atoms, an arylsulfonylaminocarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an acylaminosulfonyl group having 10 or less carbon atoms, an alkoxy group having 10 or less carbon atoms, an alkylthio group having 10 or less carbon atoms, an aryloxy group having 10 or less carbon atoms, a nitro group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an acyloxy group having 10 or less carbon atoms, an acyl group having 10 or less carbon atoms, a carbamoyl group, an aminosulfonyl group, an aryl group having 10 or less carbon atoms, a substituted amino group, a substituted ureido group, a substituted phosphono group, or a heterocyclic group, and R 13 represents a hydrogen atom or an alkyl group having 30 or less carbon atoms, and X represents a single bond, an ester group, an aliphatic alkyl chain having 30 or less carbon atoms, an aromatic chain, a polyethylene glycol chain, or a connecting group formed by combining them, and all of them may contain a spirodioxane ring.]

[0076] [A4] The optical film according to any one of [A1] to [A3], wherein the functional layer functions as at least one of an antireflection layer and an antiglare layer.

[0077] [A5] The optical film according to any one of [A1] to [A4], comprising an antistatic layer or an antifouling layer as the functional layer.

[0078] [A6] The optical film according to any one of [A1] to [A5], wherein the colored layer contains at least one of a singlet oxygen quencher and a peroxide decomposer.

[0079] [A7] The optical film according to [A6], wherein the singlet oxygen quencher is any one of dialkyl dithiophosphates, dialkyl dithiocarbamates, benzenedithiol, and transition metal complexes thereof.

[0080] [A8] An optical film according to any one of [A1] to [A7], wherein the above-mentioned pigment (A) contains one or more compounds having any structure selected from porphyrin structure, merocyanine structure, phthalocyanine structure, azo structure, cyanine structure, squarylium structure, coumarin structure, polyene structure, quinone structure, tetrazoporphyrin structure, pyrromethene structure and indigo structure, and their metal complexes.

[0081] [A9] A display device comprising the optical film according to any one of [A1] to [A8].

[0082] As another aspect, the present invention has the following aspects.

[0083] [B1] An optical film comprising:

[0084] A sheet-like transparent substrate;

[0085] a colored layer formed on the first surface side of the transparent substrate; and

[0086] The functional layer is formed on the second surface opposite to the first surface of the transparent substrate or on the colored layer.

[0087] The colored layer is formed of a cured product containing a dye (A), an energy ray curable compound (B), a photopolymerization initiator (C), and a radical scavenger (D).

[0088] The pigment (A) contains at least one of a first pigment, a second pigment, and a third pigment. The maximum absorption wavelength of the first pigment is within the range of 470 to 530 nm, and the half-peak width of the absorption spectrum is 15 to 45 nm. The maximum absorption wavelength of the second pigment is within the range of 560 to 620 nm, and the half-peak width of the absorption spectrum is 15 to 55 nm. The wavelength at which the third pigment has the lowest transmittance within the wavelength range of 380 to 780 nm is within the range of 650 to 780 nm.

[0089] The ultraviolet shielding rate of at least one of the transparent substrate and the functional layer measured in accordance with JIS L1925 is 85% or more.

[0090] The optical film is used at an illumination of 60W / cm 2 In a light resistance test in which a xenon lamp with a wavelength of 300 to 400 nm was used and the color layer was irradiated from the color layer side for 120 hours under the conditions of a temperature of 45° C. and a humidity of 50% RH in a test chamber, the following formula 1B was satisfied.

[0091] A2×(B2 / C)-D≤0.018(1B)

[0092] In the above formula (1B), A2 is the wavelength connected to 3800 cm in the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer after the above light resistance test is irradiated with infrared light. -1 and 2400cm -1 The absorbance line at 3450cm is used as the baseline. -1 B2 is the infrared absorption spectrum peak intensity of the color layer surface before the light resistance test, which is obtained by splitting the reflected light when the color layer surface is irradiated with infrared light, and the peak intensity of the infrared absorption spectrum is connected to 1650cm -1 and 1815cm -1 The absorbance line at 1650cm is used as the baseline. -1 and 1815cm -1 C is the maximum absorption peak intensity of the infrared absorption spectrum in the range of 1650cm. C is the peak intensity of the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer after the light resistance test is irradiated with infrared light, with the peak intensity connected to 1650cm -1 and 1815cm -1 The absorbance line at 1650cm is used as the baseline. -1 and 1815cm -1 D is the maximum absorption peak intensity of the infrared absorption spectrum within the range of 3800cm. D is the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer before the light resistance test is irradiated with infrared light, with the peak connecting 3800cm -1 and 2400cm -1 The absorbance line at 3450cm is used as the baseline. -1 The peak intensity of infrared absorption spectrum.

[0093] [B2] The optical film according to [B1], wherein the energy ray curable compound (B) contains 20% by weight or more of a compound having only two (meth)acryloyl groups.

[0094] [B3] The optical film according to [B1] or [B2], wherein the radical scavenger (D) is a polymer containing a structural unit represented by the following formula (i).

[0095] [Chemical structure 4]

[0096]

[0097] [In formula (i), R 12represents a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a cyano group, a hydroxyl group, an alkyl group having 10 or less carbon atoms, an alkoxycarbonyl group having 10 or less carbon atoms, an alkylsulfonylaminocarbonyl group having 10 or less carbon atoms, an arylsulfonylaminocarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an acylaminosulfonyl group having 10 or less carbon atoms, an alkoxy group having 10 or less carbon atoms, an alkylthio group having 10 or less carbon atoms, an aryloxy group having 10 or less carbon atoms, a nitro group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an acyloxy group having 10 or less carbon atoms, an acyl group having 10 or less carbon atoms, a carbamoyl group, an aminosulfonyl group, an aryl group having 10 or less carbon atoms, a substituted amino group, a substituted ureido group, a substituted phosphono group, or a heterocyclic group, and R 13 represents a hydrogen atom or an alkyl group having 30 or less carbon atoms, and X represents a single bond, an ester group, an aliphatic alkyl chain having 30 or less carbon atoms, an aromatic chain, a polyethylene glycol chain, or a connecting group formed by combining them, and all of them may contain a spirodioxane ring.]

[0098] [B4] The optical film according to any one of [B1] to [B3], wherein the colored layer contains any one of dialkyl dithiophosphates, dialkyl dithiocarbamates, benzenedithiol and transition metal complexes thereof, and a compound represented by the following formula (ii).

[0099] [Chemical structure 5]

[0100]

[0101] [In the above formula (ii), R 1 Each independently represents an alkyl group, an alkenyl group, an aryl group, a heterocyclic group or R 9 CO - , R 10 SO2 - or R 11 NHCO - The group shown, R 9 , R 10 and R 11 Each independently represents an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. 2 and R 3 Each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group or an alkenyloxy group, and R 4 ~R 8 Each independently represents a hydrogen atom, an alkyl group, an alkenyl group or an aryl group.]

[0102] [B5] An optical film according to any one of [B1] to [B4], wherein the pigment (A) comprises one or more compounds having any structure selected from a porphyrin structure, a cyanine structure, a phthalocyanine structure, an azo structure, a cyanine structure, a squarylium structure, a coumarin structure, a polyene structure, a quinone structure, a tetrazaporphyrin structure, a pyrromethene structure and an indigo structure, and their metal complexes.

[0103] [B6] The optical film according to any one of [B1] to [B5], wherein the pencil hardness of the surface of the colored layer under a load of 500 g is H or higher.

[0104] [B7] The optical film according to any one of [B1] to [B6], wherein the functional layer functions as at least one of an antireflection layer and an antiglare layer.

[0105] [B8] The optical film according to any one of [B1] to [B7], comprising an antistatic layer or an antifouling layer as the functional layer.

[0106] [B9] A display device comprising the optical film according to any one of [B1] to [B8].

[0107] Effects of the Invention

[0108] According to the present invention, an optical film that can withstand long-term use can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0109] Figure 1 This is a cross-sectional view of an optical film according to one embodiment of the present invention.

[0110] Figure 2 This is a cross-sectional view of an optical film according to another embodiment of the present invention.

[0111] Figure 3 This is a cross-sectional view of an optical film according to another embodiment of the present invention.

[0112] Figure 4 This is a cross-sectional view of an optical film according to another embodiment of the present invention.

[0113] Figure 5 This is a cross-sectional view of an optical film according to another embodiment of the present invention.

[0114] Figure 6 This is a cross-sectional view of an optical film according to another embodiment of the present invention.

[0115] Figure 7 This is a graph showing the spectrum of white display output after passing through an organic EL light source and a color filter in the example.

[0116] Figure 8Graphs showing the spectra of red, green, and blue output after passing through an organic EL light source and a color filter in the example. DETAILED DESCRIPTION

[0117] The following describes the embodiments of the present invention with reference to the accompanying drawings. In all the drawings, even when the embodiments are different, the same or corresponding components are given the same reference numerals, and the common description is omitted.

[0118] <First Embodiment>

[0119] [Optical film]

[0120] The following is based on Figure 1 The optical film according to the first embodiment of the present invention will be described in detail.

[0121] like Figure 1 As shown, the optical film 1 has a coloring layer 10, a transparent substrate 20, and a functional layer 30. The functional layer 30 has a low refractive index layer 31 and a hard coating layer 32. That is, the optical film 1 has a transparent substrate 20 located on one side of the coloring layer 10, and is a laminated body in which the coloring layer 10, the transparent substrate 20, the hard coating layer 32, and the low refractive index layer 31 are laminated in this order.

[0122] The thickness of the optical film 1 is, for example, preferably 10 to 140 μm, more preferably 15 to 120 μm, and still more preferably 20 to 100 μm. When the thickness of the optical film 1 is greater than the lower limit, the strength of the optical film 1 can be further improved. When the thickness of the optical film 1 is less than the upper limit, not only can the optical film 1 be made lighter, but it is also advantageous for thinning the display device.

[0123] Each layer constituting the optical film 1 will be described below.

[0124] Coloring Layers

[0125] 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).

[0126] The thickness of the coloring layer 10 is preferably 0.5 to 10 μm, for example. When the thickness of the coloring layer 10 is greater than the lower limit, the coloring layer 10 can contain a pigment without causing abnormality in the appearance of the coloring layer 10, and the light absorption of the pigment can improve the reflection characteristics or color reproducibility. When the thickness of the coloring layer 10 is less than the upper limit, it is advantageous for thinning the display device.

[0127] The thickness of the colored layer 10 can be calculated by observing a cross section in the thickness direction of the optical film 1 using a microscope or the like.

[0128] <Pigment (A)>

[0129] The dye (A) contains at least one of the first coloring material, the second coloring material, and the third coloring material shown below.

[0130] The maximum absorption wavelength of the first colorant is within the range of 470 to 530 nm, and the half-peak width of the absorption spectrum is 15 to 45 nm. When the maximum absorption wavelength is less than the above lower limit, the brightness efficiency of blue light emission is easily reduced, and when it exceeds the above upper limit, the brightness efficiency of green light emission is easily reduced. When the half-peak width of the absorption spectrum is less than the above lower limit, the effect of suppressing the reflection characteristics of external light is small, and when it exceeds the above upper limit, although the reflection characteristics of external light are easy to improve, the brightness efficiency is easy to reduce.

[0131] The maximum absorption wavelength of the second colorant is within the range of 560 to 620 nm, and the half-peak width of the absorption spectrum is 15 to 55 nm. When the maximum absorption wavelength is less than the above lower limit, the brightness efficiency of green luminescence is easily reduced, and when it exceeds the above upper limit, the brightness efficiency of red luminescence is easily reduced. When the half-peak width of the absorption spectrum is less than the above lower limit, the effect of suppressing the reflection characteristics of external light is small, and when it exceeds the above upper limit, although the reflection characteristics of external light are easy to improve, the brightness efficiency is easy to reduce.

[0132] The wavelength at which the third colorant has the lowest transmittance in the wavelength range of 380 to 780 nm is within the range of 650 to 780 nm. When the wavelength at which the third colorant has the lowest transmittance in the wavelength range of 380 to 780 nm is less than the above lower limit, the brightness efficiency of red light emission is easily reduced, and when it exceeds the above upper limit, the effect of suppressing the reflective characteristics of external light is reduced.

[0133] Pigment (A) preferably contains a compound or its metal complex with any structure in porphyrin structure, merocyanine structure, phthalocyanine structure, azo structure, cyanine structure, squaryl cyanine structure, coumarin structure, polyene structure, quinone structure, porphyrin tetraza structure, pyrrole methylene structure and indigo structure. Particularly use the metal complex with porphyrin structure or pyrrole methylene structure, phthalocyanine structure or the compound with squaryl cyanine structure because of excellent reliability, therefore more preferably. Pigment (A) can contain a kind of in these compounds or its metal complex separately, can also contain more than two kinds. These compounds or its metal complex can be included in the first colorant, can also be included in the second colorant, can also be included in the 3rd colorant, can also be included in more than two kinds of these colorants.

[0134] <Energy ray curable compound (B)>

[0135] The energy-ray-curable compound (B) is a resin that is cured by polymerization by irradiation with active energy rays such as ultraviolet rays and electron beams. For example, monofunctional, difunctional or trifunctional or higher (meth)acrylate monomers, urethane (meth)acrylates, etc. can be used. Here, "(meth)acrylate" refers to both or either "acrylate" and "methacrylate".

[0136] Examples of the monofunctional (meth)acrylate compound that may be contained in the energy-ray curable compound (B) include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, glycidyl (meth)acrylate, acryloylmorpholine, N-vinyl pyrrolidone, tetrahydrofurfuryl acrylate, cyclohexyl (meth)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, 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, cyclopentyl (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, (meth) acrylate 2-hydroxy-3-phenoxypropyl ester, hydrogenated phthalic acid 2-(meth)acryloyloxy The term "(meth)acryloyl" refers to a dimethylaminoethyl (meth)acrylate, trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropropyl (meth)acrylate, adamantane derivative mono (meth)acrylate such as adamantane acrylate having a monovalent mono (meth)acrylate derived from 2-adamantane and adamantanediol, etc. Here, "(meth)acryloyl" refers to both or either "acryloyl" or "methacryloyl".

[0137] Examples of the difunctional (meth)acrylate compound that may be contained in the energy-ray-curable compound (B) include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol 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, and di(meth)acrylates such as hydroxypivalate neopentyl glycol di(meth)acrylate.

[0138] Examples of trifunctional or higher-functional (meth)acrylate compounds that may be included in the energy-ray-curable compound (B) include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, tris(2-hydroxyethyl isocyanurate) tri(meth)acrylate, glycerol tri(meth)acrylate and the like tri(meth)acrylates, pentaerythritol tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, di(trimethylolpropane) tri(meth)acrylate and the like tri(meth)acrylates, The present invention also includes a (meth)acrylate compound having a functional group, a polyfunctional (meth)acrylate compound having three or more functions, such as pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, di(trimethylolpropane) penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and di(trimethylolpropane) hexa(meth)acrylate, or a polyfunctional (meth)acrylate compound in which a part of these (meth)acrylates is substituted with an alkyl group or ε-caprolactone.

[0139] In addition, as a resin that can be included in the energy-ray-curable compound (B), urethane (meth) acrylate can also be used. As urethane (meth) acrylate, for example, a product obtained by reacting an isocyanate monomer or a prepolymer with a polyester polyol, and a product obtained by reacting a (meth) acrylate monomer having a hydroxyl group with the above product.

[0140] Examples of the urethane (meth)acrylate include pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate hexamethylene diisocyanate urethane prepolymer, pentaerythritol triacrylate toluene diisocyanate urethane prepolymer, dipentaerythritol pentaacrylate toluene diisocyanate urethane prepolymer, pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer, and dipentaerythritol pentaacrylate isophorone diisocyanate urethane prepolymer.

[0141] The monofunctional, difunctional, trifunctional or higher-functional (meth)acrylate monomers, urethane (meth)acrylates, etc. that may be included in the above-mentioned other energy-ray-curable compounds (B) may be used alone or in combination of two or more. In addition, they may be partially polymerized oligomers.

[0142] The content of the energy-ray curable compound (B) is preferably 20 to 80% by mass, more preferably 30 to 70% by mass relative to the total mass of the coloring layer forming composition. When the content of the energy-ray curable compound (B) is above the above lower limit, the fading inhibition effect can be further improved. When the content of the energy-ray curable compound (B) is below the above upper limit, the handling property of the coloring layer forming composition can be further improved.

[0143] <Photopolymerization Initiator (C)>

[0144] The photopolymerization initiator (C) generates radicals when ultraviolet rays are irradiated, for example, when ultraviolet rays are used as active energy rays.

[0145] Examples of the photopolymerization initiator (C) include benzoins (benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and other benzoin alkyl ethers), phenyl ketones [e.g. acetophenones (e.g. acetophenone, 2-hydroxy-2-methyl-1-phenylpropane-1-one, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, etc.), alkyl phenyl ketones such as 2-hydroxy-2-methylpropiophenone; cycloalkyl phenyl ketones such as 1-hydroxycyclohexyl phenyl ketone, etc.], 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-tert-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, and phosphine oxides (for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc.). These photopolymerization initiators may be used alone or in combination of two or more.

[0146] The content of the photopolymerization initiator (C) is preferably 0.01 to 20% by mass, more preferably 0.01 to 5% by mass, relative to the solid content of the coloring layer forming composition. When the content of the photopolymerization initiator (C) is less than the above lower limit, the curing property is insufficient. When the content of the photopolymerization initiator (C) exceeds the above upper limit, unreacted photopolymerization initiator (C) remains, and reliability such as heat resistance deteriorates.

[0147] <Free Radical Scavenger (D)>

[0148] As the free radical scavenger (D), a resin having an amine structure can be cited. Here, "amine structure" refers to a structure in which the hydrogen atom of ammonia is replaced by a hydrocarbon group or an aromatic atomic group. As the amine structure, primary amines, secondary amines and tertiary amines can be cited, and quaternary ammonium cations can also be cited.

[0149] The free radical scavenger (D) plays a role in scavenging free radicals when the pigment (A) is oxidatively degraded, thereby inhibiting auto-oxidation and inhibiting pigment degradation (fading). As a resin having an amine structure that can be used as a free radical scavenger (D), a resin having a hindered amine structure with a molecular weight of 2000 or more can be cited. When the molecular weight of the resin having a hindered amine structure is 2000 or more, a high fading inhibition effect can be obtained. It is believed that the reason is that there are many molecules retained in the coloring layer 10, and a sufficient fading inhibition effect can be obtained.

[0150] The molecular weight of the resin having a hindered amine structure is, for example, approximately 200,000, but the upper limit is not particularly limited.

[0151] The "molecular weight" in this specification means the "mass average molecular weight" measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0152] The radical scavenger (D) in the present embodiment is an amine structure-containing polymer having a radical scavenging ability, and includes a structural unit represented by the following formula (i).

[0153] [Chemical structure 6]

[0154]

[0155] In the above formula (i), R 12 represents a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a cyano group, a hydroxyl group, an alkyl group having 10 or less carbon atoms, an alkoxycarbonyl group having 10 or less carbon atoms, an alkylsulfonylaminocarbonyl group having 10 or less carbon atoms, an arylsulfonylaminocarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an acylaminosulfonyl group having 10 or less carbon atoms, an alkoxy group having 10 or less carbon atoms, an alkylthio group having 10 or less carbon atoms, an aryloxy group having 10 or less carbon atoms, a nitro group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an acyloxy group having 10 or less carbon atoms, an acyl group having 10 or less carbon atoms, a carbamoyl group, an aminosulfonyl group, an aryl group having 10 or less carbon atoms, a substituted amino group, a substituted ureido group, a substituted phosphono group, or a heterocyclic group, and R 13 represents a hydrogen atom or an alkyl group having 30 or less carbon atoms, and X represents a single bond, an ester group, an aliphatic alkyl chain having 30 or less carbon atoms, an aromatic chain, a polyethylene glycol chain, or a linking group formed by combining them, and all of them may contain a spirodioxane ring.

[0156] As R 12 , preferably a hydrogen atom, a hydroxyl group, or an alkyl group having a carbon number of 10 or less. The alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.

[0157] As R 13 , preferably a hydrogen atom or an alkyl group having a carbon number of 10 or less. The alkyl group preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms.

[0158] X is preferably a single bond or an aliphatic alkyl chain having no greater than 30 carbon atoms. The aliphatic alkyl chain preferably has no greater than 10 carbon atoms, preferably 1 to 6 carbon atoms, and more preferably 2 to 4 carbon atoms.

[0159] In this embodiment, the radical scavenger (D) may also be a copolymer of the structural unit represented by the above formula (i) and a copolymer component having any of the following repeating units as the main component (the one with the highest mass % among the components). By using a copolymer, the compatibility with other components can be controlled.

[0160] Examples of the repeating unit include a (meth)acrylate repeating unit, an olefin repeating unit, a halogen atom-containing repeating unit, a styrene repeating unit, a vinyl acetate repeating unit, and a vinyl alcohol repeating unit.

[0161] Examples of the (meth)acrylate repeating unit include a repeating unit derived from a (meth)acrylate monomer having a linear or branched alkyl group in a side chain and a repeating unit derived from a (meth)acrylate monomer having a hydroxyl group in a side chain.

[0162] Examples of the repeating unit derived from a (meth)acrylate monomer having a linear or branched alkyl group in the side chain include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-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, decyl (meth)acrylate, 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, octadecyl (meth)acrylate and the like. These may be used alone or in combination of two or more. Among the above, a (meth)acrylate-based repeating unit having a linear or branched alkyl group having 1 to 4 carbon atoms in a side chain may be preferably used.

[0163] Examples of the repeating unit derived from a (meth)acrylic acid monomer having a hydroxyl group in the side chain include monomer-derived components such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and hydroxyphenyl (meth)acrylate. These may be used alone or in combination of two or more.

[0164] Examples of the olefin-based repeating unit include components derived from olefin-based monomers such as ethylene, propylene, isoprene, and butadiene, and these may be used alone or in combination of two or more.

[0165] Examples of the halogen atom-containing repeating unit include monomer-derived components such as vinyl chloride and vinylidene chloride, which may be used alone or in combination of two or more.

[0166] Examples of the styrene-based repeating unit include styrene-based monomer-derived components such as styrene, α-methylstyrene, and vinyltoluene, and these may be used alone or in combination of two or more.

[0167] Examples of the vinyl acetate-based repeating unit include esters of saturated carboxylic acids such as vinyl acetate and vinyl propionate and vinyl alcohol. These may be used alone or in combination of two or more.

[0168] Examples of the vinyl alcohol-based repeating unit include vinyl alcohol, which may have a 1,2-glycol bond in a side chain.

[0169] The copolymer may have any structure of a random copolymer, an alternating copolymer, a block copolymer, and a graft copolymer. If the structure of the copolymer is a random copolymer, the manufacturing process and the preparation with other components become easy. Therefore, a random copolymer is more preferred than other copolymers.

[0170] The polymerization method for obtaining the copolymer can use free radical polymerization. Free radical polymerization is preferred in terms of easy industrial production. Free radical polymerization can be solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization. Free radical polymerization preferably uses solution polymerization. By using solution polymerization, it is easy to control the molecular weight in the copolymer.

[0171] In the radical polymerization, the monomers may be polymerized by adding a polymerization initiator after diluting the monomers with a polymerization solvent.

[0172] The polymerization solvent may be, for example, an ester solvent, an alcohol ether solvent, a ketone solvent, an aromatic solvent, an amide solvent, and an alcohol solvent. Ester solvents may be, for example, methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, tert-butyl acetate, methyl lactate, and ethyl lactate. Alcohol ether solvents may be, for example, 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-3-methyl-1-butanol. Ketone solvents may be, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Aromatic solvents may be, for example, benzene, toluene, and xylene. Amide solvents may be, for example, formamide and dimethylformamide. Examples of the alcohol solvent include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, diacetone alcohol, and 2-methyl-2-butanol. The polymerization solvents may be used alone or in combination of two or more.

[0173] The free radical polymerization initiator may be, for example, a peroxide and an azo compound. The peroxide may be, for example, benzoyl peroxide, tert-butyl peroxyacetate, tert-butyl peroxybenzoate, and di-tert-butyl peroxide. The azo compound may be, for example, azobisisobutyronitrile, azobisamidinopropane salt, azobiscyanovaleric acid (salt), and 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], and the like.

[0174] The amount of the radical polymerization initiator used is preferably 0.0001 mass part or more and 20 mass parts or less, more preferably 0.001 mass part or more and 15 mass parts or less, and further preferably 0.005 mass part or more and 10 mass parts or less when the total amount of monomers is set to 100 mass parts. The radical polymerization initiator can be added to the monomer and the polymerization solvent before the start of polymerization, or can be added dropwise to the polymerization reaction system. From the aspect of being able to suppress the heat generated by polymerization, the radical polymerization initiator is preferably added dropwise to the monomer and the polymerization solvent in the polymerization reaction system.

[0175] The reaction temperature of the radical polymerization is appropriately selected according to the types of the radical polymerization initiator and the 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.

[0176] 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) is preferably 1 to 95 mol%, more preferably 10 to 90 mol%, relative to the total molar amount of the monomers constituting the energy-ray curable compound (B). 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 pigment (A) are improved, and fading is easily suppressed.

[0177] The colored layer 10 may further contain a solvent (E) or an additive (F), and the details thereof will be described below.

[0178] <Solvent (E)>

[0179] The solvent (E) is essential for forming the colored layer. Although most of it disappears from the colored layer by volatilization or the like during drying after coating, a part of it remains in the colored layer, and therefore its composition is described below.

[0180] As the solvent (E), ethers, ketones, esters, and cellosolves can be mentioned. As ethers, for example, dibutyl ether, dimethoxymethane, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole or phenethyl ether can be mentioned. As ketones, for example, acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone or ethylcyclohexanone can be mentioned. As esters, for example, ethyl formate, propyl formate, n-pentyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, n-pentyl acetate or γ-butyrolactone can be mentioned. Examples of the cellosolves include methyl cellosolve, cellosolve (ethyl cellosolve), butyl cellosolve, and cellosolve acetate, etc. The solvent (E) may be used alone or in combination of two or more.

[0181] The content of the solvent (E) is preferably 20 to 80% by mass, more preferably 30 to 70% by mass, relative to the total mass of the coloring layer forming composition containing the above (A) to (D). When the content of the solvent (E) is above the above lower limit, the handleability of the coloring layer forming composition can be further improved. When the content of the solvent (E) is below the above upper limit, the time for forming the coloring layer can be shortened.

[0182] <Additives (F)>

[0183] Specific examples of the additive (F) include singlet oxygen quenchers, peroxide decomposers, leveling agents, defoamers, antioxidants, ultraviolet absorbers, light stabilizers, photosensitizers, and conductive materials.

[0184] Examples of the singlet oxygen quencher include dialkyl dithiophosphates, dialkyl dithiocarbamates, benzenedithiol, and transition metal complexes thereof.

[0185] When the colored layer contains a singlet oxygen quencher, the light resistance and heat resistance of the dye (A) can be improved.

[0186] The inventors have conducted various studies on a structure that can ensure a surface hardness that can withstand roll-to-roll manufacturing while not reducing the light resistance of the functional colorant. As a result, they found that by making the color layer 780 to 825 cm -1 Specifically, when the peak intensity of the infrared absorption spectrum of the colored layer 10 is within a predetermined range and a radical scavenger is contained, the color layer 10 is -1 The infrared absorption spectrum peak intensity of A and pentaerythritol tetraacrylate is set at 780-825 cm -1 When the infrared absorption spectrum peak intensity is set as B, by making A / B not less than 0.01 and not more than 0.25, both the surface hardness and the light resistance can be improved. The details will be shown later using the examples. When the above A / B is less than 0.01, the hardness of the cured color layer is not sufficient, and when it exceeds 0.25, the possibility of insufficient light resistance increases.

[0187] The detailed mechanism by which the colored layer 10 of this embodiment exerts the above-mentioned effect is not completely clear, but it is known that -1 The peak intensity of the infrared absorption spectrum becomes an indicator of the degree of double bonds. In the coloring layer 10 of the present embodiment, it is considered that hardness is imparted by ensuring a certain amount of double bonds in the structure of the coloring layer, while suppressing the amount of double bonds from becoming excessive, thereby suppressing the generation of free radicals that deteriorate the functional colorant when light irradiates the double bonds, and at the same time, the reduction in light resistance is suppressed by capturing the free radicals generated further using a free radical scavenger.

[0188] It is effective to adjust the A / B value as described above by using a compound having only two (meth)acryloyl groups as a material used in the energy-ray curable compound (B). The inventors have found in their research that the preferred range of A / B described above can be easily achieved when the energy-ray curable compound (B) contains 20% by weight or more of a compound having only two (meth)acryloyl groups.

[0189] 《Transparent substrate》

[0190] The transparent substrate 20 is a sheet-like member that is located on one surface of the colored layer 10 and forms the optical film 1 .

[0191] As the material of the transparent substrate 20, a resin film with light transmittance can be used. As the forming material of the transparent substrate 20, a transparent resin or inorganic glass can be used. As the transparent resin, for example, polyolefin, polyester, polyacrylate, polyamide, polyimide, polyarylate, polycarbonate, triacetyl cellulose, polyvinyl alcohol, polyvinyl chloride, cycloolefin copolymer, norbornene-containing resin, polyether sulfone, and polysulfone can be cited. As polyolefin, for example, polyethylene and polypropylene can be cited. As polyester, for example, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate can be cited. As polyacrylate, for example, polymethyl methacrylate can be cited. As polyamide, for example, nylon 6, nylon 66, etc. can be cited. Among them, it is preferred to use a film formed by polyethylene terephthalate (PET), a film formed by triacetyl cellulose (TAC), a film formed by polymethyl methacrylate (PMMA), and a film formed by polyester other than PET.

[0192] The thickness of the transparent substrate 20 is not particularly limited, but is preferably, for example, 10 to 100 μm.

[0193] The transmittance of the transparent base material 20 is preferably, for example, 90% or more.

[0194] It is also possible to impart ultraviolet absorption capability to the transparent substrate 20. By adding an ultraviolet absorber to the resin serving as the raw material of the transparent substrate 20, it is possible to impart ultraviolet absorption capability to the transparent substrate 20.

[0195] Examples of the ultraviolet absorber include salicylate ultraviolet absorbers, benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers, benzotriazine ultraviolet absorbers, and cyanoacrylate ultraviolet absorbers.

[0196] These ultraviolet absorbers may be used alone or in combination of two or more.

[0197] When ultraviolet absorption capability is imparted to the transparent substrate 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 calculated by the following formula.

[0198] Ultraviolet shielding rate (%) = 100 - average transmittance of ultraviolet rays with a wavelength of 290 to 400 nm (%)

[0199] When the ultraviolet shielding rate is less than 85%, the fading-inhibiting effect due to the light resistance of the dye (A) is reduced.

[0200] Functional Layer

[0201] The functional layer 30 is located on one surface or the other surface of the colored layer 10. The optical film can exhibit various functions by including the functional layer 30.

[0202] Examples of the function of the functional layer 30 include an antireflection function, an antiglare function, an antistatic function, an antifouling function, a reinforcing function, and an ultraviolet absorption function (ultraviolet absorption capability).

[0203] The functional layer 30 may be a single layer or a plurality of layers. The functional layer 30 may have one function or two or more functions.

[0204] When the optical film 1 has an anti-reflection function, the functional layer 30 functions as an anti-reflection layer. As the anti-reflection layer, a low refractive index layer 31 having a refractive index lower than that of the hard coating layer 32, the anti-glare layer 34, and the transparent substrate 20 described later can be cited. The low refractive index layer 31 can be formed by using a material having a refractive index lower than that of the hard coating layer 32, the anti-glare layer 34, and the transparent substrate 20 in the functional layer.

[0205] In order to adjust the refractive index of the low refractive index layer 31, lithium fluoride (LiF), magnesium fluoride (MgF2), sodium aluminum hexafluoride (cryolite, cryolite, 3NaF·AlF3, Na3AlF6), and aluminum fluoride (AlF3) and other particles, or silica particles, etc. can also be added. As silica particles, porous silica particles or hollow silica particles with voids inside the particles are used, which is effective for lowering the refractive index of the low refractive index layer 31. In addition, the photopolymerization initiator (C), solvent (E), and additive (F) described in the colored layer 10 can be appropriately added to the composition for forming the low refractive index layer 31 (composition for forming the low refractive index layer).

[0206] The refractive index of the low refractive index layer 31 is preferably 1.20 to 1.55.

[0207] The thickness of the low refractive index layer 31 is not particularly limited, but is preferably, for example, 40 nm to 1 μm.

[0208] 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 is a layer having fine concavo-convex surfaces, which scatters external light to suppress reflection 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 anti-reflection layer.

[0209] The anti-glare layer 34 includes one or more selected from organic particles and inorganic particles as required. Organic particles are materials that form fine concavo-convex on the surface and impart the function of scattering external light. As organic particles, for example, resin particles formed by light-transmitting resin materials such as acrylic resin, polystyrene resin, styrene-(methyl)acrylate copolymer, polyethylene resin, epoxy resin, silicone resin, polyvinylidene fluoride, and polyfluorinated vinyl resin can be cited. In order to adjust the dispersibility of the refractive index or the resin particles, two or more resin particles with different materials (refractive index) can also be used in a mixed manner.

[0210] Inorganic particles are materials for adjusting the sedimentation or aggregation of organic particles. As inorganic particles, for example, silica particles, metal oxide particles, and various mineral particles can be used. As silica particles, for example, colloidal silica or silica particles surface-modified with reactive functional groups such as (meth) acryloyl groups can be used. As metal oxide particles, for example, aluminum oxide, zinc oxide, tin oxide, antimony oxide, indium oxide, titanium dioxide, and zirconium dioxide can be used. As mineral particles, for example, mica, synthetic mica, vermiculite, montmorillonite, iron montmorillonite, bentonite, beidellite, soapstone, hectorite, stevenstone, nontronite, magadiite, illite, nadzinite, layered titanic acid, smectite, and synthetic smectite can be used. Mineral particles can be either natural or synthetic (including substitutions and derivatives), or a mixture of the two can be used. Among mineral particles, layered organic clay is more preferred. Layered organic clay refers to organic onium ions introduced between the layers of swelling clay. There is no restriction on the organic onium ions as long as they can be organically formed by utilizing the cation exchange property of swelling clay. When layered organic clay minerals are used as mineral particles, the above-mentioned synthetic montmorillonite can be preferably used. Synthetic montmorillonite has the function of increasing the viscosity of the coating liquid used for forming the anti-glare layer, inhibiting the sedimentation of resin particles and inorganic particles, and adjusting the concavo-convex shape of the surface of the anti-glare layer 34 (functional layer 30).

[0211] When the optical film 1 has an antistatic function, the functional layer 30 functions as an antistatic layer. Examples of the antistatic layer include a layer containing metal oxide particles such as antimony-doped tin oxide (ATO) and tin-doped indium oxide (ITO), a polymer conductive composition, and an antistatic agent such as a quaternary ammonium salt.

[0212] The antistatic layer may be provided on the outermost surface of the functional layer 30 or between the functional layer 30 and the transparent substrate 20. Alternatively, the antistatic layer may be formed by adding an antistatic agent to any layer constituting the functional layer 30. When the antistatic layer is provided, the surface resistance of the optical film is preferably 1.0×10 6 ~1.0×1012 (Ω / cm).

[0213] When the optical film 1 has an antifouling function, the functional layer 30 functions as an antifouling layer. The antifouling layer improves the antifouling property by imparting both or either hydrophobicity and oleophobicity. Examples of the antifouling layer include layers containing antifouling agents such as silicon oxides, fluorinated silane compounds, fluoroalkyl silazanes, fluoroalkyl silanes, fluorinated silicon compounds, and perfluoropolyether-containing silane coupling agents.

[0214] The antifouling layer may be provided on the outermost surface of the functional layer 30 , and the antifouling layer may be formed by mixing an antifouling agent into the outermost layer of the functional layer 30 .

[0215] When the optical film 1 has a strengthening function, the functional layer 30 functions as a strengthening layer. The strengthening layer is a layer that improves the strength of the optical film. As the strengthening layer, for example, a hard coating layer 32 can be cited. As the hard coating layer 32, for example, a layer formed by a hard coating agent containing a monofunctional, difunctional, or trifunctional or higher (meth) acrylate, or a urethane (meth) acrylate can be cited.

[0216] When the optical film 1 has ultraviolet absorption capability, the functional layer 30 functions as an ultraviolet absorption layer. Examples of the ultraviolet absorption layer include a layer containing a triazine-based ultraviolet absorber such as 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-hexyloxyphenol and a benzotriazole-based ultraviolet absorber such as 2-(2H-benzotriazol-2-yl)-4-methylphenol.

[0217] The content of the ultraviolet absorber is preferably 0.1 to 5% by mass relative to the total mass of the material forming the ultraviolet absorbing layer. When the content of the ultraviolet absorber is greater than the above lower limit, sufficient ultraviolet absorbing ability can be imparted to the functional layer 30. When the content of the ultraviolet absorber is less than the above upper limit, insufficient hardness due to a decrease in the curing component can be avoided.

[0218] In the optical film 1, the ultraviolet shielding rate of one or both of the transparent substrate 20 and the functional layer 30 is 85% or more, preferably 90% or more, more preferably 95% or more, and may be 100%. When the ultraviolet shielding rate is equal to or higher than the above lower limit, the light resistance and heat resistance can be further improved.

[0219] The ultraviolet shielding rate can be measured according to the method described in JIS L1925.

[0220] The ultraviolet shielding rate can be adjusted by imparting ultraviolet absorbing capability to one or both of the transparent substrate 20 and the functional layer 30 .

[0221] The thickness of the functional layer 30 is, for example, preferably 0.04 to 25 μm, more preferably 0.1 to 20 μm, and further preferably 0.2 to 15 μm. When the thickness of the functional layer 30 is greater than or equal to the lower limit, it is easy to impart various functions to the optical film 1. When the thickness of the functional layer 30 is less than or equal to the upper limit, it is advantageous for reducing the thickness of the display device.

[0222] [Method for producing optical film]

[0223] The optical film 1 of the present embodiment can be produced by a conventionally known method.

[0224] For example, the colored layer 10 is obtained by applying a colored layer-forming composition containing (A) to (D) (and further containing (E) or (F)) on one surface of the transparent substrate 20 and curing the colored layer-forming composition by irradiating it with active energy rays.

[0225] The light source used for irradiating active energy rays to cure the coloring layer forming composition to form the coloring layer 10 can be used without particular limitation as long as it is a light source that generates active energy rays. As active energy rays, light energy rays such as radiation (gamma rays, X-rays, etc.), ultraviolet rays, visible rays, and electron beams (EB) can be used, and usually ultraviolet rays and electron beams are mostly used. For example, as a lamp that radiates ultraviolet rays, 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, and an electrodeless discharge tube can be used. As irradiation conditions, the ultraviolet irradiation amount is usually 100 to 1000 mJ / cm 2 .

[0226] Next, a hard coating agent is applied to the other surface of the transparent substrate 20 , and the hard coating agent is cured by irradiating the hard coating agent with active energy rays in the same manner as the colored layer 10 , thereby obtaining the hard coating layer 32 .

[0227] 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 substrate 20 is obtained.

[0228] The method for forming the low refractive index layer 31 is not particularly limited, and may include a method of applying a low refractive index layer-forming composition on the hard coating layer 32 and curing it by irradiating it with active energy rays, a vacuum evaporation method, a sputtering method, an ion plating method, an ion beam method, and a plasma vapor deposition method.

[0229] [Other embodiments]

[0230] The optical film can also be Figure 2 The optical film 3 shown in the figure has a transparent substrate 20 on one surface of a colored layer 10, and is a laminate of the colored layer 10, the transparent substrate 20, and the anti-glare layer 34 in this order. In the optical film 3, the anti-glare layer 34 constitutes the functional layer 30.

[0231] Since the optical film 3 of the present embodiment includes the anti-glare layer 34 , it is excellent in suppressing reflection.

[0232] The optical film can also be Figure 3 The optical film 4 shown has a transparent substrate 20 on one side of the coloring layer 10, and is a laminate of the coloring layer 10, the transparent substrate 20, the anti-glare layer 34 and the low refractive index layer 31 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.

[0233] The optical film 4 of the present embodiment has the low refractive index layer 31 and the anti-glare layer 34 and therefore is more excellent in suppressing reflection.

[0234] The optical film can also be Figure 4 The optical film 5 shown has a transparent substrate 20 located on one surface of a colored layer 10 and a functional layer 30 located on the other surface of the colored layer 10, and is a transparent substrate 20, a colored layer 10, a hard coating layer 32, and a low refractive index layer 31 stacked in this order. In the optical film 5, the hard coating layer 32 and the low refractive index layer 31 constitute the functional layer 30.

[0235] The optical film 5 of the present embodiment has a colored layer 10 and a functional layer 30 having an ultraviolet absorption function and an antireflection function on one surface of a transparent substrate 20. The ultraviolet absorption function may be imparted to any of the layers constituting the functional layer.

[0236] The optical film can also be Figure 5 The optical film 7 shown has a transparent substrate 20 on one side of a coloring layer 10 and an antiglare layer 34 on the other side of the coloring layer 10. The transparent substrate 20, the coloring layer 10 and the antiglare layer 34 are sequentially stacked. In the optical film 7, the antiglare layer 34 constitutes the functional layer 30.

[0237] Since the optical film 7 of the present embodiment includes the anti-glare layer 34 , it is excellent in suppressing reflection.

[0238] In the optical film 7 , it is preferable that the anti-glare layer 34 be provided with an ultraviolet absorbing function.

[0239] The optical film can also be Figure 6 The optical film 8 shown has a transparent substrate 20 located on one surface of a colored layer 10 and a functional layer 30 located on the other surface of the colored layer 10, and is a transparent substrate 20, a colored layer 10, an anti-glare layer 34 and a low refractive index layer 31 stacked in sequence. In the optical film 8, the anti-glare layer 34 and the low refractive index layer 31 constitute the functional layer 30.

[0240] Since the optical film 8 of the present embodiment includes the low refractive index layer 31 and the anti-glare layer 34 , it is more excellent in suppressing reflection.

[0241] In the optical film 8 , it is preferred that an ultraviolet absorbing function be imparted to any of the layers constituting the functional layer 30 .

[0242] [Display device]

[0243] The display device of the present invention has the optical film of this embodiment. As a specific example of the display device, for example, a television, a display, a mobile phone, a portable game console, a portable information terminal, a personal computer, an electronic book, a video camera, a digital camera, a head-mounted display, a navigation system, an audio playback device (car audio, digital audio player, etc.), a copier, a fax machine, a printer, a printer compound machine, a vending machine, an automatic teller machine (ATM), a personal authentication device, an optical communication device, an IC card, etc., can be listed. Among them, it is preferably used in a display device having self-luminous elements such as LED, organic EL, inorganic phosphor, and quantum dots that are easily affected by external light reflection due to metal electrodes and wiring.

[0244] According to the optical film of each embodiment described above, the cured colored layer 10 has sufficient hardness and can be manufactured with good productivity by roll-to-roll method. In addition, the light resistance and heat resistance of the colorant contained in the colored layer can be improved, and reflection suppression and brightness efficiency can be taken into account. Therefore, the display device having the optical film of this embodiment can improve the display quality and prolong the life of the light-emitting element.

[0245] <Second Embodiment>

[0246] Next, a second embodiment of the present invention will be described. The basic structure is the same as that of the first embodiment. Therefore, the same structure is assigned the same reference numerals, and the description thereof is omitted, and only the differences are described.

[0247] Coloring Layers

[0248] The coloring layer 10 is a cured product of a coloring layer forming composition, and contains a pigment (A), an active energy ray curable resin (B), a photopolymerization initiator (C), and a radical scavenger (D). Since the pigment (A), the active energy ray curable resin (B), and the photopolymerization initiator (C) are the same as those in the first embodiment, description thereof is omitted.

[0249] The radical scavenger (D) of the present embodiment is not limited to the polymer described in the radical scavenger (D) of the first embodiment, and a hindered amine-based light stabilizer or the like may also be used.

[0250] As in the first embodiment, a solvent (E) or an additive (F) may be contained in the coloring layer 10. Since the solvent (E) is the same as in the first embodiment, the description thereof is omitted. In the second embodiment, since the additive (F) is different from that in the first embodiment, the details thereof are described below.

[0251] <Additives (F)>

[0252] Examples of the additive (F) include a compound having at least a structure represented by the following formula (ii) (hereinafter referred to as "compound A") and a sulfur-based antioxidant.

[0253] [Chemical structure 7]

[0254]

[0255] In formula (ii), R 1 are independently alkyl, alkenyl, aryl, heterocyclic, R 9 CO-、R 10 SO2-, and R 11 Any of the groups shown in NHCO- 9 , R 10 , R 11 are each independently any one of an alkyl group, an alkenyl group, an aryl group, and a heterocyclic group). 2 and R 3 Each is independently any one of a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group, and an alkenyloxy group. 4 ~R 8 Each is independently any one of a hydrogen atom, an alkyl group, an alkenyl group, and an aryl group.

[0256] Examples of the sulfur-based antioxidant include dialkyl dithiophosphates, dialkyl dithiocarbamates, benzenedithiol, and transition metal complexes thereof.

[0257] The coloring layer contains the compound A and the sulfur-based antioxidant, whereby the light resistance and heat resistance of the pigment (A) can be improved.

[0258] The additive (F) may further contain a leveling agent, a defoaming agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a photosensitizer, a conductive material, and the like as other additives.

[0259] The colored layer 10 contains the colored layer forming composition of this embodiment, and can improve light resistance and heat resistance without the need for a gas barrier layer, taking into account both reflection suppression and brightness efficiency, thereby improving display quality, extending the life of the light-emitting element, and improving color reproducibility.

[0260] Furthermore, the additive (F) of the second embodiment may be the same as the additive (F) described in the first embodiment.

[0261] Since the optical film of each embodiment described above contains the radical scavenger (D) in the colored layer, it is possible to improve light resistance and heat resistance without providing a gas barrier layer, and to achieve both reflection suppression and brightness efficiency.

[0262] As a result, even when subjected to a severe light resistance test, the optical properties can be maintained. 2 In a light resistance test in which a xenon lamp with a wavelength of 300 to 400 nm was used and the color layer was irradiated from the color layer side for 120 hours under the conditions of a temperature of 45° C. and a humidity of 50% RH in a test chamber, the following formula 1B was satisfied.

[0263] A2×(B2 / C)-D≤0.018(1B)

[0264] In the above formula (1B), A2 is the wavelength connected to 3800 cm in the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer after the above light resistance test is irradiated with infrared light. -1 and 2400cm -1 The absorbance line at 3450cm is used as the baseline. -1 The peak intensity of infrared absorption spectrum.

[0265] B2 is the infrared absorption spectrum obtained by splitting the reflected light when the surface of the colored layer before the light resistance test is irradiated with infrared light, with the wavelength connected to 1650cm -1 and 1815cm -1 The absorbance line at 1650cm is used as the baseline. -1 and 1815cm -1 The maximum absorption peak intensity of the infrared absorption spectrum within the range.

[0266] C is the infrared absorption spectrum obtained by splitting the reflected light when the surface of the colored layer after the light resistance test is irradiated with infrared light, with the wavelength connected to 1650cm -1 and 1815cm -1 The absorbance line at 1650cm is used as the baseline. -1 and 1815cm -1 The maximum absorption peak intensity of the infrared absorption spectrum within the range.

[0267] D is the infrared absorption spectrum obtained by splitting the reflected light when the surface of the colored layer before the light resistance test is irradiated with infrared light, with the wavelength connecting 3800 cm -1 and 2400cm -1 The absorbance line at 3450cm is used as the baseline. -1 The peak intensity of infrared absorption spectrum.

[0268] In addition, the inventors have found that when the energy-ray curable compound (B) contains 20% by weight or more of a compound having only two (meth)acryloyl groups, the amount of double bonds in the structure of the coloring layer is suppressed from becoming excessive, and the generation of free radicals that degrade the functional colorant when the double bonds are irradiated with light can be suppressed, which is more preferable. In this configuration, since a certain amount of double bonds can be ensured in the structure of the coloring layer, sufficient hardness can be given to the coloring layer, and the pencil hardness of the surface of the coloring layer under a load of 500g can also reach H or above.

[0269] A display device including the optical film of this embodiment having the above-described characteristics can improve display quality and extend the life of a light-emitting element.

[0270] Although the embodiments of the present invention have been described in detail above with reference to the drawings, specific configurations are not limited to the embodiments and modifications and combinations of configurations that do not depart from the gist of the present invention are also included.

[0271] For example, each of the above optical films has one colored layer, but the number of colored layers may be 2 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.

[0272] In the optical film of each embodiment, ultraviolet absorption capability may be imparted to the transparent substrate 20 or to the functional layer 30 such as the hard coat layer 32. It is important to impart ultraviolet absorption capability to a layer closer to the screen viewed by the user than the colored layer 10 when mounted in a display device.

[0273] Example

[0274] The present invention is described in more detail below using examples. The technical scope of the present invention is based only on the specific contents of these examples and is not limited in any way.

[0275] [Examples 1 to 13, Comparative Examples 1 to 9]

[0276] In the following examples and comparative examples, optical films 1 to 22 having the layer structures shown in Table 1 were prepared. The optical film properties and the display device properties of the organic EL panel were evaluated by simulation for the prepared optical films 1 to 22. "-" in the table means that the layer is not present.

[0277]

[0278] 《Production of optical films》

[0279] The method of forming each layer will be described below.

[0280] [Formation of Colored Layer]

[0281] As the material used for the coloring layer, the following materials are used.

[0282] In addition, the maximum absorption wavelength, the full width at half maximum, and the minimum transmittance wavelength within a specified wavelength range of the colorant are characteristic values in the cured coating film.

[0283] <(Azo pigment)>

[0284] · First colorant

[0285] Dye-1: Pyrromethene cobalt complex dye (maximum absorption wavelength: 493 nm, full width at half maximum: 26 nm)

[0286] <Production example of Dye-1>

[0287] Ethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate (2.5 g) was sealed in a reaction vessel, dissolved in methanol (50 mL), and then 47% hydrobromic acid (45 g) was added, followed by reflux for 1 hour. The precipitated solid was filtered to obtain 3,3’,5,5’-tetramethyl-4,4’-diethoxycarbonyl-2,2’-dipyrromethene hydrobromide (2.6 g).

[0288] 3,3’,5,5’-tetramethyl-4,4’-di-ethoxycarbonyl-2,2’-dipyrromethene hydrobromide (0.6 g) was sealed in a reaction vessel, methanol (5 mL), triethylamine (0.17 g), and cobalt(II) acetate tetrahydrate (0.18 g) were added, and reflux was carried out for 2 hours. The precipitated solid was filtered to obtain Dye-1 (0.42 g).

[0289] Dye-2: Pyrromethene cobalt complex dye (maximum absorption wavelength: 496 nm, full width at half maximum: 23 nm)

[0290] <Production example of Dye-2>

[0291] Dye-2 was synthesized in the same procedure as in the above <Production example of Dye-1>, except that ethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate was changed to methyl 4-butyl-2-ethyl-5-formyl-1H-pyrrole-3-carboxylate.

[0292] · Second colorant

[0293] Dye-3: Tetraazaporphyrin copper complex dye (manufactured by Yamada Chemical Industry Co., Ltd., FDG-007, maximum absorption wavelength: 595 nm, full width at half maximum: 22 nm)

[0294] · Third colorant

[0295] Dye-4: Copper phthalocyanine complex dye (manufactured by Yamada Chemical Industry Co., Ltd., FDN-002, minimum transmittance wavelength in the range of 400 to 780 nm is 780 nm)

[0296] Other pigments

[0297] Dye-5: Dye FDG-003 (manufactured by Yamada Chemical Industry Co., Ltd., FDG-003, maximum absorption wavelength: 545 nm, half-peak width: 79 nm)

[0298] In addition, Dye-5 is a comparative object used only in the comparative example and does not belong to the second color material in the present application.

[0299] <Energy ray curable compound (B)>

[0300] ·DCPA: tricyclodecane dimethanol diacrylate

[0301] ·DCPM: tricyclodecane dimethanol dimethacrylate

[0302] ·DOGA: dioxane glycol diacrylate

[0303] NP-A: Neopentyl glycol diacrylate

[0304] BP-4EAL: EO adduct of bisphenol A diacrylate

[0305] PE3A: Pentaerythritol triacrylate

[0306] PE4A: Pentaerythritol tetraacrylate

[0307] DPHA: Dipentaerythritol hexaacrylate

[0308] 510H: Dipentaerythritol hexaacrylate hexamethylene diisocyanate urethane prepolymer (manufactured by Kyoei Chemical Co., Ltd., UA-510H)

[0309] PMMA: Methyl methacrylate polymer (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0310] In addition, PMMA is not an active energy ray-curable resin, but is used only as a comparative object in the comparative examples, and therefore is also described in this column.

[0311] In addition, "Functionality" in Table 2 indicates the number of functional groups of the (meth)acryloyl group.

[0312] <Photopolymerization Initiator (C)>

[0313] Omnirad TPO: acylphosphine oxide-based photopolymerization initiator (manufactured by IGM Resins BV)

[0314] <Free Radical Scavenger (D)>

[0315] LA-63P: Hindered amine light stabilizer ADK STAB LA-63P (manufactured by ADEKA Corporation)

[0316] Resin 1: A polymer comprising a structural unit represented by the above formula (i)

[0317] <Production Example of Resin 1>

[0318] 2.4 g of 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate (FA-711MM manufactured by Showa Denko Materials Co., Ltd.), 5.6 g of methyl methacrylate (manufactured by Kanto Chemical Co., Ltd.), 31 g of cyclohexanone (manufactured by Kanto Chemical Co., Ltd.), and 0.11 g of 2,2'-azobis(isobutyronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were placed in a reaction container, and heated and stirred at 70°C for 8 hours under a nitrogen atmosphere. Thereafter, heated and stirred at 100°C for 1 hour to obtain a polymer solution. The polymer solution was injected into 400 mL of methanol (manufactured by Kanto Chemical Co., Ltd.) to generate a precipitate, which was filtered and dried to obtain a resin 1 copolymerized with 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate:methyl methacrylate=15:85 [mol%].

[0319] By performing additional heating and stirring at 100° C. for 1 hour, 2,2′-azobis(isobutyronitrile) as an initiator can be completely decomposed, and deterioration of the optical film due to the residual initiator can be suppressed.

[0320] In addition, by injecting the polymer solution into methanol, unreacted monomers, polymerization solvents, decomposition products of the initiator, and the like can be removed, and deterioration of the optical film can be suppressed.

[0321] <Solvent (E)>

[0322] MEK: Methyl Ethyl Ketone

[0323] Methyl acetate

[0324] <Additives (F)>

[0325] Compound A: T1477 having the structure shown in the following formula (ii). 1 For C3H7, R 2 ~R 8 For H.

[0326] Singlet oxygen quencher: bis(dibutyldithiocarbamate)nickel(II) (D1781 manufactured by Tokyo Chemical Industry Co., Ltd.)

[0327] [Chemical structure 8]

[0328]

[0329] (Transparent substrate)

[0330] The following were used as the transparent substrate.

[0331] TAC: triacetyl cellulose film (manufactured by Fujifilm Corporation, TG60UL, substrate thickness: 60 μm, ultraviolet shielding rate: 92.9%).

[0332] (Formation of Colored Layer)

[0333] The coloring layer forming composition shown in Table 2 was applied to the transparent substrate shown in Table 1 and dried in an oven at 80° C. for 60 seconds. Then, an ultraviolet irradiation device was used to irradiate the substrate at a dose of 150 mJ / cm 2 The coating was cured by ultraviolet irradiation (Fusion UV Systems Japan Co., Ltd., light source H bulb) to form a colored layer with a thickness of 5.0 μm after curing. In addition, the added amount is a mass ratio (mass %). "-" in the table means that the component is not contained.

[0334]

[0335] [Formation of functional layer: hard coat layer]

[0336] (Materials used in the hard coat layer forming composition)

[0337] As materials used in the hard coat layer-forming composition used for forming the hard coat layer, the following materials were used.

[0338] Active energy ray curable resin

[0339] UA-306H: Pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer (manufactured by Kyoeisha Chemical Co., Ltd., UA-306H)

[0340] DPHA

[0341] PE3A: Pentaerythritol triacrylate (LIGHT ACRYLATE PE-3A manufactured by Kyoeisha Chemical Co., Ltd.)

[0342] Photopolymerization initiator

[0343] Omnirad TPO

[0344] ·Additives (ultraviolet (UV) absorbers)

[0345] Tinuvin 479: Hydroxyphenyltriazine-based ultraviolet absorber, Tinuvin (registered trademark) 479 (manufactured by BASF Japan Co., Ltd.)

[0346] LA-36: Benzotriazole-based ultraviolet absorber, ADK STAB (registered trademark) LA-36 (manufactured by ADEKA Corporation)

[0347] Solvent

[0348] MEK: Methyl Ethyl Ketone

[0349] Methyl acetate

[0350] Using these substances, two kinds of coating solutions for hard coating layers shown in Table 3 were prepared.

[0351] [Table 3]

[0352]

[0353] (Formation of hard coat layer)

[0354] The hard coat coating solution was applied onto the transparent substrate or the colored layer shown in Table 1 and dried in an oven at 80°C for 60 seconds. Then, an ultraviolet irradiation device was used to irradiate the substrate at a dose of 150 mJ / cm 2 The coating was cured by ultraviolet irradiation (Fusion UV Systems Japan Co., Ltd., light source H bulb) to form a hard coating layer so that the thickness after curing was 5.0 μm. Hard coating layer 1 had no ultraviolet absorbing ability, and hard coating layer 2 had ultraviolet absorbing ability.

[0355] [Formation of functional layer: anti-glare layer]

[0356] (Materials used in the composition for forming an anti-glare layer)

[0357] As materials used in the anti-glare layer-forming composition used for forming the anti-glare layer, the following materials were used.

[0358] Active energy ray curable resin

[0359] PE3A

[0360] Photopolymerization initiator

[0361] Omnirad TPO

[0362] Resin particles

[0363] Styrene-methyl methacrylate copolymer particles (refractive index 1.515, average particle size 2.0 μm)

[0364] Inorganic particles

[0365] Synthetic montmorillonite

[0366] Alumina nanoparticles (average particle size 40nm)

[0367] ·Additives (ultraviolet (UV) absorbers)

[0368] Tinuvin479

[0369] LA-36

[0370] Solvent

[0371] Toluene

[0372] Isopropyl alcohol

[0373] Using these materials, antiglare layer coating solutions 1 and 2 having the following compositions were prepared.

[0374] Anti-glare coating liquid 1

[0375]

[0376] Anti-glare coating liquid 2

[0377]

[0378] (Formation of Anti-glare Layer)

[0379] One of the antiglare layer coating solutions was applied onto the transparent substrate shown in Table 1 and dried in an oven at 80° C. for 60 seconds. Then, an ultraviolet irradiation device was used to irradiate the substrate at a dose of 150 mJ / cm 2 The coating was cured by ultraviolet irradiation (manufactured by Fusion UV Systems Japan Co., Ltd., light source H bulb) to form an antiglare layer 1 or 2 so that the thickness after curing was 5.0 μm. The antiglare layer 1 did not have ultraviolet absorption capability, while the antiglare layer 2 had ultraviolet absorption capability.

[0380] [Formation of functional layer: low refractive index layer]

[0381] (Composition for forming low refractive index layer)

[0382] As the low refractive index layer-forming composition used for forming the low refractive index layer, the following was used.

[0383] Refractive index modifier

[0384] 8.5 parts by mass of porous silica fine particles (average particle size 75 nm, solid content 20%) in methyl isobutyl ketone dispersion

[0385] Antifouling agent

[0386] OPTOOL (registered trademark) AR-110 (manufactured by Daikin Industries, Ltd., solid content: 15%, solvent: methyl isobutyl ketone) 5.6 parts by mass

[0387] Active energy ray curable resin

[0388] PE-3A 0.4 parts by mass

[0389] Photopolymerization initiator

[0390] Omnirad TPO 0.07 parts by mass

[0391] Leveling agent

[0392] RS-77 (manufactured by DIC Corporation) 1.7 parts by mass

[0393] Solvent

[0394] Methyl isobutyl ketone 83.73 parts by mass

[0395] (Formation of Low Refractive Index Layer)

[0396] The above-mentioned low refractive index layer-forming composition was applied on the hard coat layer or the antiglare layer shown in Table 1, and dried in an oven at 80° C. for 60 seconds. Then, an ultraviolet irradiation device was used to irradiate the layer at a dose of 150 mJ / cm 2 The coating film was cured by ultraviolet irradiation (manufactured by Fusion UV Systems Japan Co., Ltd., light source H bulb) to form a low refractive index layer having a film thickness of 100 nm after curing.

[0397] In addition, the order of stacking the layers on the optical film is as shown in Table 1. For example, in the optical film 1 of Example 1, a coloring layer 1, a substrate (TAC), a hard coating layer 1, and a low refractive index layer are stacked in sequence. That is, in Example 1, the transparent substrate is arranged at an upper layer than the coloring layer. In the optical film 21 of Example 12, a substrate (TAC), a coloring layer 10, a hard coating layer 2, and a low refractive index layer are stacked in sequence. That is, in Example 12, the coloring layer is arranged at an upper layer than the substrate.

[0398] [Evaluation of film properties]

[0399] <Infrared absorption spectrum measurement>

[0400] The infrared absorption spectrum of the coloring layer of each example was measured by the ATR method using FT-IR6300 manufactured by JASCO Corporation. The infrared absorption spectrum of PE4A was also measured by the same method. The infrared absorption spectrum of 780 cm to 825 cm was calculated from each spectrum. -1The maximum peak height of the absorbance within the range was calculated. In addition, the spectrum of each sample was measured 10 times, the maximum peak height was calculated respectively, and the average value was taken as the peak intensity value of the sample. The peak intensity of the colored layer was set as A, and the peak intensity of PE4A was set as B, and A / B was calculated.

[0401] <Ultraviolet shielding rate on the colored layer>

[0402] When the transparent substrate is arranged at an upper layer than the colored layer, the transmittance of the substrate is measured using an automatic spectrophotometer (U-4100, manufactured by Hitachi, Ltd.). In addition, when the colored layer is arranged at an upper layer than the substrate, the layer above the colored layer is peeled off using a transparent pressure-sensitive tape according to the JIS-K5600-5-6:1999 adhesion test standard, and the transmittance of the layer above the colored layer is measured using an automatic spectrophotometer (U-4100) with the tape as a reference. The average transmittance [%] in the ultraviolet region (290nm to 400nm) is calculated using these transmittances, and the value obtained by subtracting the average transmittance [%] in the ultraviolet region (290nm to 400nm) from 100% is calculated as the ultraviolet shielding rate [%].

[0403] <Pencil hardness test>

[0404] According to JIS-K5400-1990, a pencil hardness test was performed on the surface of each colored layer using a Clemens scratch hardness tester (HA-301 manufactured by Tester Industry Co., Ltd.) with a 500 g load (UNI manufactured by Mitsubishi Pencil Co., Ltd., pencil hardness H). The change in appearance due to scratches was visually evaluated, and the case where no scratches were observed was evaluated as "○ (pass)", and the case where scratches were observed was evaluated as "× (failure)".

[0405] <Light resistance test>

[0406] The obtained optical film was tested for light resistance using a xenon lamp weathering tester (manufactured by Suga Test Instruments Co., Ltd., X75) at a xenon lamp illumination of 60 W / cm 2 The test was conducted for 120 hours under the conditions of (300-400nm), 45°C in the test machine, and 50%RH. The transmittance was measured before and after the test using an automatic spectrophotometer (U-4100). The transmittance difference ΔT before and after the test at the wavelength λ showing the minimum transmittance in the maximum absorption wavelength range of the first to third colorants was calculated. The evaluation was divided into the following three levels, and those other than × were evaluated as qualified.

[0407] ◎(good): ΔT less than 3%

[0408] ○ (fair): ΔT is 3% or more and less than 4.5%

[0409] × (bad): ΔT is 4.5% or more

[0410] [Display device characteristics evaluation]

[0411] <White Display Transmission Characteristics>

[0412] The transmittance of the obtained optical film was measured using an automatic spectrophotometer (U-4100), and the efficiency of light passing through the optical film during white display was calculated using the transmittance, which was evaluated as the white display transmission characteristics. Figure 7 The efficiency of the spectrum in the case of white display output after passing through the white organic EL light source and the color filter is set to 100. The closer to 100, the higher the white display transmittance and the better the luminance efficiency.

[0413] <Reflection Characteristics of Display Device>

[0414] 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 the surface reflectance R2(λ), a matte black dye was applied to the surface of the transparent substrate where no coloring layer and functional layer were formed to perform anti-reflection treatment, and the spectral reflectance at an incident angle of 5° was measured as the surface reflectance R2(λ). E (λ) is 100% in the wavelength range of 380nm to 780nm, and the interface reflection and surface reflection in each layer are not considered. The relative reflection value when the display device reflection value for the D65 light source in the state without the optical film is calculated according to the following formulas (1) to (4) is taken as 100, and the surface reflectivity R(λ) of the outermost layer on the observer side is evaluated as the display device reflection characteristic. The lower the value of the display device reflection characteristic, the less external light reflection can be achieved, and the better the reflection characteristic. In addition, in formulas (1) to (4), R1(λ) represents the internal reflection component, Y represents one of the three stimulus values ​​of the white point of the D65 light source, and P D65 (λ) represents the spectrum of the D65 light source, and the upper line y(λ) represents the CIE1931 color matching function.

[0415] [Mathematical formula 1]

[0416]

[0417] [Mathematical formula 2]

[0418] R(λ)[%]=R1(λ)+R2(λ)…(2)

[0419] [Mathematical formula 3]

[0420]

[0421] [Formula 4]

[0422]

[0423] <Color Reproducibility>

[0424] The transmittance of the obtained optical film was measured using an automatic spectrophotometer (U-4100). Figure 7 The spectrum shown is the output after passing through a white EL light source and a color filter. Figure 8 Red display, green display, and blue display spectrum. Figure 7 and Figure 8 The vertical axis of the curve represents the luminous intensity [au] (arbitrary unit). Figure 8 The NTSC (National Television Standards Committee) ratio is calculated from the CIE1931 chromaticity values ​​calculated from the red, green, and blue display spectra, and the NTSC ratio is used as an indicator of color reproducibility. The higher the NTSC ratio, the better the color reproducibility.

[0425] The results are shown in Table 4. The results of the display device characteristic evaluation were performed only on some examples, and the ratios of the white display transmission characteristics and the display device reflection characteristics are shown together with the ratios based on Comparative Example 8 having no coloring layer (100%).

[0426]

[0427] In Examples 1 to 13 and Comparative Examples 1 to 9, the optical films of Examples all had A / B of 0.01 or more and 0.25 or less, exhibited good light resistance, and had sufficient hardness.

[0428] 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. Comparative Example 8 without a colored layer or Comparative Example 9 without any of the first to third colorants had insufficient color reproducibility.

[0429] The present invention is described in more detail below using other embodiments. The technical scope of the present invention is based only on the specific contents of these embodiments and is not limited thereto.

[0430] [Examples 2-1 to 2-10, Comparative Examples 2-1 to 2-8]

[0431] In the following examples and comparative examples, optical films 2-1 to 2-18 having the layer structures shown in Tables 5 and 6 were prepared. The optical film properties and the display device properties of the organic EL panel evaluated by simulation are shown for the prepared optical films 2-1 to 2-18. "-" in the table means that the layer is not present.

[0432] [Table 5]

[0433]

[0434]

[0435] "Fabrication of Optical Film"

[0436] The formation method of each layer will be described below.

[0437] [Formation of Coloring Layer]

[0438] (Materials Used in the Composition for Forming Coloring Layer)

[0439] The composition of the coloring layer in the examples is shown in Table 7, and the composition of the coloring layer in the comparative examples is shown in Table 8. The following materials are used as the materials.

[0440] In addition, the maximum absorption wavelength, full width at half maximum, and minimum transmittance wavelength within a specified wavelength range of the pigment are characteristic values of the cured coating film.

[0441] [Pigment (A)]

[0442] · First Pigment

[0443] Dye-1: Pyrromethene Cobalt Complex Dye (maximum absorption wavelength: 493 nm, full width at half maximum: 26 nm)

[0444] [Manufacturing Example of Dye-1]

[0445] Ethyl 5-formyl-2,4-dimethyl-1H-pyrrole-3-carboxylate (2.5 g) was sealed in a reaction vessel, dissolved in methanol (50 mL), and then 47% hydrobromic acid (45 g) was added, followed by refluxing for 1 hour. The precipitated solid was filtered to obtain 3,3',5,5'-tetramethyl-4,4'-di-ethoxycarbonyl-2,2'-dipyrromethene hydrobromide (2.6 g).

[0446] 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), triethylamine (0.17 g), and cobalt(II) acetate tetrahydrate (0.18 g) were added, followed by refluxing for 2 hours. The precipitated solid was filtered to obtain Dye-1 (0.42 g).

[0447] · Second Pigment

[0448] Dye-3: Tetraazaporphyrin Copper Complex Dye (manufactured by Yamada Chemical Industry Co., Ltd., FDG-007, maximum absorption wavelength: 595 nm, full width at half maximum: 22 nm)

[0449] Dye-3B: Dye FDG-003 (manufactured by Yamada Chemical Industry Co., Ltd., FDG-003, maximum absorption wavelength: 545 nm, half-peak width: 79 nm)

[0450] In addition, Dye-3B is a comparative object used only in the comparative example and does not belong to the second color material of the present application.

[0451] ·Third color material

[0452] Dye-4: Copper phthalocyanine complex dye (manufactured by Yamada Chemical Industry Co., Ltd., FDN-002, minimum transmittance wavelength in the range of 400 to 780 nm is 780 nm)

[0453] <Active Energy Ray-Curable Resin (B)>

[0454] ·DCPA: tricyclodecane dimethanol diacrylate

[0455] ·DCPM: tricyclodecane dimethanol dimethacrylate

[0456] 510H: Dipentaerythritol hexaacrylate hexamethylene diisocyanate urethane prepolymer (manufactured by Kyoeisha Chemical Co., Ltd., UA-510H)

[0457] PE4A: Pentaerythritol tetraacrylate

[0458] DPHA: Dipentaerythritol hexaacrylate

[0459] PMMA: Methyl methacrylate polymer (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0460] In addition, PMMA is not an active energy ray-curable resin, but is used in the comparative examples only as a comparison object, and therefore is also described in this column.

[0461] In addition, the "number of functional groups" in Tables 7 and 8 indicates the number of functional groups of the (meth)acryloyl group.

[0462] <Photopolymerization Initiator (C)>

[0463] Omnirad TPO: acylphosphine oxide-based photopolymerization initiator (manufactured by IGM Resins BV)

[0464] <Free Radical Scavenger (D)>

[0465] LA-63P: Hindered amine light stabilizer ADK STAB LA-63P (manufactured by ADEKA Corporation)

[0466] Resin 1: A polymer comprising a structural unit represented by the above formula (i)

[0467] <Production Example of Resin 1>

[0468] 2.4 g of 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate (FA-711MM manufactured by Showa Denko Materials Co., Ltd.), 5.6 g of methyl methacrylate (manufactured by Kanto Chemical Co., Ltd.), 31 g of cyclohexanone (manufactured by Kanto Chemical Co., Ltd.), and 0.11 g of 2,2'-azobis(isobutyronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were placed in a reaction container, and heated and stirred at 70°C for 8 hours under a nitrogen atmosphere. Thereafter, heated and stirred at 100°C for 1 hour to obtain a polymer solution. The polymer solution was injected into 400 mL of methanol (manufactured by Kanto Chemical Co., Ltd.) to generate a precipitate, which was filtered and dried to obtain a resin 1 copolymerized with 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate:methyl methacrylate=15:85 [mol%].

[0469] By performing additional heating and stirring at 100° C. for 1 hour, 2,2′-azobis(isobutyronitrile) as an initiator can be completely decomposed, and deterioration of the optical film due to the residual initiator can be suppressed.

[0470] In addition, by injecting the polymer solution into methanol, unreacted monomers, polymerization solvent, decomposition products of the initiator, and the like can be removed, and deterioration of the optical film can be suppressed.

[0471] <Solvent (E)>

[0472] MEK: Methyl Ethyl Ketone

[0473] Methyl acetate

[0474] <Additives (F)>

[0475] Compound A: T1477 having the structure shown in the above formula (ii). 1 For C3H7, R 2 ~R 8 For H.

[0476] · D1781: Singlet oxygen quencher (bis(dibutyldithiocarbamate)nickel(II), manufactured by Tokyo Chemical Industry Co., Ltd.)

[0477]

[0478]

[0479] (Transparent substrate)

[0480] As the transparent substrate, the following were used.

[0481] TAC: triacetyl cellulose film (manufactured by Fujifilm Corporation, TG60UL, substrate thickness: 60 μm, ultraviolet shielding rate: 92.9%).

[0482] PMMA: polymethyl methacrylate film (manufactured by Sumitomo Chemical Co., Ltd., W002N80, substrate thickness 80 μm, ultraviolet shielding rate 13.9%)

[0483] (Formation of Colored Layer)

[0484] The coloring layer forming composition shown in Table 7 and Table 8 was applied to the transparent substrate shown in Table 5 and Table 6, and dried in an oven at 80°C for 60 seconds. Then, an ultraviolet irradiation device was used to irradiate the transparent substrate at a dose of 150 mJ / cm 2 (Fusion Systems Japan Co., Ltd., light source H bulb) was irradiated with ultraviolet light to cure the coating film, and a coloring layer was formed so that the film thickness after curing was 5.0 μm. In addition, the addition amount is a mass ratio (mass %). "-" in the table means that the component is not contained.

[0485] [Formation of functional layer: hard coat layer]

[0486] (Materials used in the hard coat layer forming composition)

[0487] As materials used in the hard coat layer-forming composition used for forming the hard coat layer, the following materials were used.

[0488] Active energy ray curable resin

[0489] UA-306H: Pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer (manufactured by Kyoeisha Chemical Co., Ltd., UA-306H)

[0490] DPHA

[0491] PE-3A: Pentaerythritol triacrylate (LIGHT ACRYLATE PE-3A manufactured by Kyoeisha Chemical Co., Ltd.)

[0492] Photopolymerization initiator

[0493] Omnirad TPO: acylphosphine oxide-based photopolymerization initiator (manufactured by IGM Resins BV)

[0494] ·Additives (ultraviolet (UV) absorbers)

[0495] Tinuvin 479: Hydroxyphenyltriazine-based ultraviolet absorber, Tinuvin (registered trademark) 479 (manufactured by BASF Japan Co., Ltd.).

[0496] LA-36: Benzotriazole-based ultraviolet absorber, ADK STAB (registered trademark) LA-36 (manufactured by ADEKA Corporation).

[0497] Solvent

[0498] MEK: Methyl Ethyl Ketone

[0499] Methyl acetate

[0500] Using these substances, two kinds of coating solutions for hard coating layers shown in Table 9 were prepared.

[0501] [Table 9]

[0502]

[0503] (Formation of hard coat layer)

[0504] The corresponding hard coating solution was applied on the transparent substrate or the colored layer shown in Table 5 or Table 6, and dried in an oven at 80°C for 60 seconds. Then, an ultraviolet irradiation device was used to irradiate the substrate at a dose of 150 mJ / cm 2 The coating was cured by ultraviolet irradiation (Fusion UV Systems Japan Co., Ltd., light source H bulb) to form a hard coating layer so that the thickness after curing was 5.0 μm. Hard coating layer 1 had no ultraviolet absorbing ability, and hard coating layer 2 had ultraviolet absorbing ability.

[0505] [Formation of functional layer: anti-glare layer B]

[0506] (Anti-glare layer forming composition)

[0507] As the anti-glare layer-forming composition used for forming the anti-glare layer B, the following was used.

[0508] Active energy ray curable resin

[0509] PE3A 43.7 parts by mass

[0510] Photopolymerization initiator

[0511] Omnirad TPO (manufactured by IGM Resins BV) 4.55 parts by mass

[0512] Resin particles

[0513] Styrene-methyl methacrylate copolymer particles (refractive index: 1.515, average particle size: 2.0 μm) 0.5 parts by mass

[0514] Inorganic particles

[0515] 0.25 mass parts of synthetic montmorillonite

[0516] Alumina nanoparticles (average particle size 40 nm) 1.0 mass part

[0517] Solvent

[0518] Toluene 15 parts by mass

[0519] Isopropyl alcohol 35 parts by mass

[0520] (Formation of Anti-glare Layer)

[0521] The anti-glare layer-forming composition was applied onto the transparent substrate shown in Table 5 and dried in an oven at 80° C. for 60 seconds. Then, an ultraviolet irradiation device was used to irradiate the substrate at a dose of 150 mJ / cm 2 The coating film was cured by ultraviolet irradiation (manufactured by Fusion UV Systems Japan Co., Ltd., light source H bulb), and an antiglare layer B was formed so that the film thickness after curing was 5.0 μm.

[0522] [Formation of functional layer: low refractive index layer]

[0523] (Composition for forming low refractive index layer)

[0524] As the low refractive index layer-forming composition used for forming the low refractive index layer, the following was used.

[0525] Refractive index modifier

[0526] 8.5 parts by mass of porous silica fine particles (average particle size 75 nm, solid content 20%) in methyl isobutyl ketone dispersion

[0527] Antifouling agent

[0528] OPTOOL (registered trademark) AR-110 (manufactured by Daikin Industries, Ltd., solid content: 15%, solvent: methyl isobutyl ketone) 5.6 parts by mass

[0529] Active energy ray curable resin

[0530] PE-3A 0.4 parts by mass

[0531] Photopolymerization initiator

[0532] Omnirad TPO (manufactured by IGM Resins BV) 0.07 parts by mass

[0533] Leveling agent

[0534] RS-77 (manufactured by DIC Corporation) 1.7 parts by mass

[0535] Solvent

[0536] Methyl isobutyl ketone 83.73 parts by mass

[0537] (Formation of Low Refractive Index Layer)

[0538] The above-mentioned low refractive index layer-forming composition was applied on the hard coat layer or the antiglare layer shown in Table 5 or Table 6, and dried in an oven at 80°C for 60 seconds. Then, an ultraviolet irradiation device was used to irradiate the layer at a dose of 200 mJ / cm 2 The coating film was cured by ultraviolet irradiation (manufactured by Fusion UV Systems Japan Co., Ltd., light source H bulb) to form a low refractive index layer having a thickness of 100 nm after curing.

[0539] In addition, the order of stacking the layers on the optical film is as shown in Tables 5 and 6. For example, in the optical film 2-1 of Example 2-1, a colored layer 2-1, a substrate (TAC), a hard coating layer 1, and a low refractive index layer are stacked in sequence. That is, in Example 2-1, the transparent substrate is arranged at a higher layer than the colored layer. In the optical film 2-10 of Example 2-10, a substrate (PMMA), a colored layer 2-7, a hard coating layer 2, and a low refractive index layer are stacked in sequence. That is, in Example 2-10, the colored layer is arranged at a higher layer than the substrate.

[0540] The following evaluations were performed on the optical films of the respective examples.

[0541] [Evaluation of film properties]

[0542] <Ultraviolet shielding rate on the colored layer>

[0543] When the transparent substrate is arranged at an upper layer than the colored layer, the transmittance of the substrate is measured using an automatic spectrophotometer (U-4100, manufactured by Hitachi, Ltd.). In addition, when the colored layer is arranged at an upper layer than the substrate, the layer above the colored layer is peeled off using a transparent pressure-sensitive tape according to the JIS-K5600-5-6:1999 adhesion test standard, and the transmittance of the layer above the colored layer is measured using an automatic spectrophotometer (U-4100) with the tape as a reference. The average transmittance [%] in the ultraviolet region (290nm to 400nm) is calculated using these transmittances, and the value obtained by subtracting the average transmittance [%] in the ultraviolet region (290nm to 400nm) from 100% is calculated as the ultraviolet shielding rate [%].

[0544] <Light resistance test>

[0545] The obtained optical film was tested for light resistance using a xenon lamp weathering tester (manufactured by Suga Test Instruments Co., Ltd., X75) at a xenon lamp illumination of 60 W / cm 2The test was conducted for 120 hours under the conditions of (300 to 400 nm), 45°C in the test machine, and 50% RH. The transmittance was measured before and after the test using an automatic spectrophotometer (U-4100), and the transmittance difference ΔTλ1 before and after the test at the wavelength λ1 showing the minimum transmittance before the test in the wavelength range of 470 nm to 530 nm and the transmittance difference ΔTλ2 before and after the test at the wavelength λ2 showing the minimum transmittance before the test in the wavelength range of 560 nm to 620 nm were calculated. In addition, the wavelength λ1 can also be said to be the wavelength showing the minimum transmittance by the first colorant with the maximum absorption wavelength in the range of 470 to 530 nm, and the wavelength λ2 can also be said to be the wavelength showing the minimum transmittance by the second colorant with the maximum absorption wavelength in the range of 560 to 620 nm. The closer the transmittance difference is to zero, the better it is, preferably |ΔTλN|≤15 (N=1 to 3), and more preferably |ΔTλN|≤10 (N=1 to 3).

[0546] The evaluation is divided into the following three levels, and those other than × are considered pass.

[0547] ◎(Excellent): |ΔTλN|≤10

[0548] 0(Good): 10<|ΔTλN|≤15

[0549] ×(Bad): 15<|ΔTλN|

[0550] <Heat resistance test>

[0551] As a heat resistance test of the obtained optical film, the test was conducted at 90°C for 500 hours, and the transmittance was measured before and after the test using an automatic spectrophotometer (manufactured by Hitachi, Ltd., U-4100), and the transmittance difference ΔTλ1 before and after the test at the wavelength λ1 showing the minimum transmittance before the test in the wavelength range of 470nm to 530nm, and the transmittance difference ΔTλ2 before and after the test at the wavelength λ2 showing the minimum transmittance before the test in the wavelength range of 560nm to 620nm were calculated. The closer the transmittance difference is to zero, the better, preferably |ΔTλN|≤15 (N=1 to 3), and more preferably |ΔTλN|≤10 (N=1 to 3).

[0552] The evaluation is divided into the following three levels, and those other than × are considered pass.

[0553] ◎(Excellent): |ΔTλN|≤10

[0554] 0(Good): 10<|ΔTλN|≤15

[0555] ×(Bad): 15<|ΔTλN|

[0556] <Infrared absorption spectrum>

[0557] The 4000 cm-1 wavelength before and after the light resistance test was measured by the ATR method using FT-IR6300 manufactured by JASCO Corporation. -1 ~400cm -1 The value of the above formula (1B) is then calculated based on the measurement results.

[0558] <Pencil hardness test>

[0559] According to JIS-K5400-1990, a pencil hardness test was performed on the surface of each colored layer using a Clemens scratch hardness tester (HA-301 manufactured by Tester Industry Co., Ltd.) with a 500 g load (UNI manufactured by Mitsubishi Pencil Co., Ltd., pencil hardness H). The change in appearance due to scratches was visually evaluated, and the case where no scratches were observed was evaluated as "○ (pass)", and the case where scratches were observed was evaluated as "× (failure)".

[0560] [Display device characteristics evaluation]

[0561] <White Display Transmission Characteristics>

[0562] The transmittance of the obtained optical film was measured using an automatic spectrophotometer (U-4100, manufactured by Hitachi, Ltd.), and the efficiency of light passing through the optical film during white display was calculated using the transmittance, which was evaluated as white display transmission characteristics. Figure 7 The efficiency of the spectrum in the case of white display output after passing through the white organic EL light source and the color filter is set to 100. The closer to 100, the higher the white display transmittance and the better the luminance efficiency.

[0563] <Reflection Characteristics of Display Device>

[0564] 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 the surface reflectance R2(λ), a matte black dye was applied to the surface of the transparent substrate where no coloring layer and functional layer were formed to perform anti-reflection treatment, and the spectral reflectance at an incident angle of 5° was measured as the surface reflectance R2(λ). E(λ) is 100% in the wavelength range of 380nm to 780nm, and the interface reflection and surface reflection in each layer are not considered. The relative reflection value is calculated according to the following formulas (1) to (4) when the display device reflection value of the D65 light source (CIE (International Illumination Commission) standard light source D65) in the state without an optical film is taken as 100, and the surface reflectivity R(λ) of the outermost layer on the observer side is evaluated as the reflection characteristic of the display device. The lower the value of the reflection characteristic of the display device, the less external light reflection can be, and the better the reflection characteristic. In addition, in formulas (1) to (4), R1(λ) represents the internal reflection component, Y represents one of the three stimulus values ​​of the white point of the D65 light source, and P D65 (λ) represents the spectrum of the D65 light source, and the upper line y(λ) represents the CIE1931 color matching function.

[0565] [Formula 5]

[0566]

[0567] [Mathematical formula 6]

[0568] R(λ)[%]=R1(λ)+R2(λ)…(2)

[0569] [Formula 7]

[0570]

[0571] [Mathematical formula 8]

[0572]

[0573] <Color Reproducibility>

[0574] The transmittance of the obtained optical film was measured using an automatic spectrophotometer (U-4100). Figure 7 The spectrum shown is the output after passing through a white EL light source and a color filter. Figure 8 Red display, green display, and blue display spectrum. Figure 7 and Figure 8 The vertical axis of the curve represents the luminous intensity [au] (arbitrary unit). Figure 8 The NTSC (National Television Standards Committee) ratio is calculated from the CIE1931 chromaticity values ​​calculated from the red, green, and blue display spectra, and the NTSC ratio is used as an indicator of color reproducibility. The higher the NTSC ratio, the better the color reproducibility.

[0575] The results are shown in Tables 10 to 12. The results of the display device characteristic evaluation shown in Table 12 were performed only on some examples, and the ratios of the white display transmission characteristics and the display device reflection characteristics are also shown with reference to Comparative Example 2-8 having no coloring layer (100%).

[0576] [Table 10]

[0577]

[0578]

[0579]

[0580] In Examples 2-1 to 2-10 and Comparative Examples 2-1 to 2-8, the optical films of Examples all satisfied the above formula (1B) and showed good light resistance and heat resistance. In addition, the coloring layer contained an energy-ray curable compound, thereby having sufficient hardness.

[0581] The results of Examples 2-10 show that when the coloring layer and the functional layer are provided on the same side of the substrate, if the functional layer formed on the coloring layer has sufficient ultraviolet shielding ability, the light resistance and heat resistance of the optical film can be well maintained.

[0582] On the other hand, although the comparative examples that did not satisfy the above formula (1B) had almost no problem in terms of hardness, they could not achieve both light resistance and heat resistance.

[0583] Although one embodiment and examples of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and includes changes and combinations of the configurations that do not depart from the gist of the present invention.

[0584] Explanation of symbols

[0585] 1, 3, 4, 5, 7, 8 Optical film

[0586] 10 Coloring Layer

[0587] 20 Transparent substrate

[0588] 30 functional layers

[0589] 31 Low refractive index layer

[0590] 32 Hard coating

[0591] 34 Anti-glare layer

Claims

1. An optical film comprising: A sheet-like transparent substrate; a colored layer formed on the first surface side of the transparent substrate; and The functional layer is formed on the second surface of the transparent substrate opposite to the first surface or on the colored layer, wherein: The coloring layer is formed of a cured product containing a pigment (A), an energy ray curable compound (B), a photopolymerization initiator (C), and a radical scavenger (D). The pigment (A) contains at least one of a first colorant, a second colorant, and a third colorant, The maximum absorption wavelength of the first colorant is within the range of 470 to 530 nm, and the half-peak width of the absorption spectrum is 15 to 45 nm. The maximum absorption wavelength of the second colorant is within the range of 560 to 620 nm, and the half-peak width of the absorption spectrum is 15 to 55 nm. The wavelength at which the third colorant has the lowest transmittance within the wavelength range of 380 to 780 nm is within the range of 650 to 780 nm. The ultraviolet shielding rate of at least one of the transparent substrate and the functional layer is 85% or more in a measurement based on JIS L1925, The optical film satisfies at least one of the following (1) or (2): (1) 780 to 825 cm of the colored layer -1 The infrared absorption spectrum peak intensity of A and pentaerythritol tetraacrylate is 780-825 cm -1 When the peak intensity of the infrared absorption spectrum of is set to B, A / B is greater than or equal to 0.01 and less than or equal to 0.25, (2) When using an illumination of 60W / cm 2 In a light resistance test in which a xenon lamp with a wavelength of 300 to 400 nm is used to irradiate the colored layer from the colored layer side for 120 hours under the conditions of a temperature of 45° C. and a humidity of 50% RH in a testing machine, the following formula 1B is satisfied: A2×(B2 / C)-D≤0.018(1B) In the formula (1B), A2 is the wavelength connected to 3800 cm in the infrared absorption spectrum obtained by spectroscopically analyzing reflected light when the surface of the colored layer after the light resistance test is irradiated with infrared light. -1 and 2400cm -1 The absorbance line at 3450cm is used as the baseline. -1 The infrared absorption spectrum peak intensity of the color layer surface before the light resistance test is obtained by splitting the reflected light when the infrared light is irradiated on the surface of the color layer. -1 and 1815cm -1 The absorbance line at 1650cm is used as the baseline. -1 and 1815cm -1 C is the maximum absorption peak intensity of the infrared absorption spectrum within the range of 1650cm; C is the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer after the light resistance test is irradiated with infrared light, with the peak connecting 1650cm -1 and 1815cm -1 The absorbance line at 1650cm is used as the baseline. -1 and 1815cm -1 D is the maximum absorption peak intensity of the infrared absorption spectrum within the range of 3800cm; D is the infrared absorption spectrum obtained by spectroscopically analyzing the reflected light when the surface of the colored layer before the light resistance test is irradiated with infrared light, with the wavelength connecting 3800cm -1 and 2400cm -1 The absorbance line at 3450cm is used as the baseline. -1 The peak intensity of infrared absorption spectrum.

2. The optical film according to claim 1, wherein: The energy-ray-curable compound (B) contains 20% by weight or more of a compound having only two (meth)acryloyl groups.

3. The optical film according to claim 1, wherein The free radical scavenger (D) is a polymer comprising a structural unit represented by the following formula (i), In formula (i), R 12 represents a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a cyano group, a hydroxyl group, an alkyl group having 10 or less carbon atoms, an alkoxycarbonyl group having 10 or less carbon atoms, an alkylsulfonylaminocarbonyl group having 10 or less carbon atoms, an arylsulfonylaminocarbonyl group, an alkylsulfonyl group, an arylsulfonyl group, an acylaminosulfonyl group having 10 or less carbon atoms, an alkoxy group having 10 or less carbon atoms, an alkylthio group having 10 or less carbon atoms, an aryloxy group having 10 or less carbon atoms, a nitro group, an alkoxycarbonyloxy group, an aryloxycarbonyloxy group, an acyloxy group having 10 or less carbon atoms, an acyl group having 10 or less carbon atoms, a carbamoyl group, an aminosulfonyl group, an aryl group having 10 or less carbon atoms, a substituted amino group, a substituted ureido group, a substituted phosphono group, or a heterocyclic group, and R 13 represents a hydrogen atom or an alkyl group having 30 or less carbon atoms, and X represents a single bond, an ester group, an aliphatic alkyl chain having 30 or less carbon atoms, an aromatic chain, a polyethylene glycol chain, or a linking group formed by combining them, and all of them may contain a spirodioxane ring.

4. The optical film according to claim 1, wherein The functional layer functions as at least one of an antireflection layer and an antiglare layer.

5. The optical film according to claim 1, wherein As the functional layer, there is an antistatic layer or an antifouling layer.

6. The optical film according to claim 1, wherein: The pigment (A) includes one or more compounds having any structure selected from the group consisting 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 tetraazaporphyrin structure, a pyrromethene structure and an indigo structure, and metal complexes thereof. 7 . The optical film according to claim 1 , wherein the colored layer satisfies the condition (1), and comprises at least one of a singlet oxygen quencher and a peroxide decomposer. 8 . The optical film according to claim 7 , wherein the singlet oxygen quencher satisfies the condition (1), and the singlet oxygen quencher is any one of dialkyl dithiophosphates, dialkyl dithiocarbamates, benzenedithiol, and transition metal complexes thereof.

9. The optical film according to claim 1, wherein the coloring layer satisfies the condition (2), wherein the coloring layer contains any one of dialkyl dithiophosphate, dialkyl dithiocarbamate, benzenedithiol and transition metal complexes thereof, and a compound represented by the following formula (ii): In the formula (ii), R 1 Each independently represents an alkyl group, an alkenyl group, an aryl group, a heterocyclic group or R 9 CO - , R 10 SO2 - or R 11 NHCO - The group shown, R 9 , R 10 and R 11 Each independently represents an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and R 2 and R 3 Each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an alkoxy group or an alkenyloxy group, and R 4 ~R 8 Each independently represents a hydrogen atom, an alkyl group, an alkenyl group or an aryl group. 10 . The optical film according to claim 1 , wherein the condition (2) is satisfied, and the pencil hardness of the surface of the colored layer under a load of 500 g is H or higher. 11 . A display device comprising the optical film according to claim 1 .

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