Wavelength selective absorption filter, liquid crystal display device, and organic electroluminescent display device

Abstract

The present invention provides a wavelength selective absorption filter, a liquid crystal display device including the same, and an organic electroluminescent display device, the wavelength selective absorption filter having a substrate film and a wavelength selective absorption filter layer disposed in contact with the substrate film, the wavelength selective absorption filter layer contains: a carboxyl group-containing resin; and 0.1 part by mass or more of a dye having a main absorption wavelength band at a wavelength of 460-520 nm relative to 100 parts by mass of the resin.

Description

Technical Field

[0001] The present invention relates to a wavelength selective absorption filter, a liquid crystal display device, and an organic electroluminescent display device. Background Art

[0002] In recent years, organic electroluminescent (OLED) display devices and liquid crystal display devices have been used as image display devices.

[0003] As an image display device with low power consumption and space saving, the use of liquid crystal display devices has been expanding year by year. In a liquid crystal display device, the liquid crystal panel itself for displaying an image is a non-light emitting element that does not emit light, and thus a backlight unit is provided on the back of the liquid crystal panel to supply light to the liquid crystal panel.

[0004] An OLED display device is a device that displays an image using the self-luminescence of OLED (Organic Light Emitting Diodes) elements. Therefore, compared with various display devices such as liquid crystal display devices and plasma display devices, it has the advantages of being able to achieve a high contrast ratio, high color reproducibility, wide viewing angle, high-speed response, and thin and light weight. In addition to these advantages, from the aspect of flexibility, it has been actively researched and developed as a next-generation display device.

[0005] In the development of image display devices, a technique of assembling a wavelength selective absorption filter as a structure is known.

[0006] For example, in a liquid crystal display device, when a white light emitting diode (LED) is used as a light source for a backlight unit, a wavelength selective absorption filter is tried to be provided to block light of unnecessary wavelengths emitted from the white LED. Also, in an OLED display device, a wavelength selective absorption filter is tried to be provided from the viewpoint of suppressing external light reflection.

[0007] In recent years, attempts have also been made to provide a wavelength selective absorption filter in a display device using self-luminescence such as an OLED element, a micro LED (Light Emitting Diodes) element, or a mini LED element in order to suppress a decrease in contrast in bright places and improve color reproducibility.

[0008] In particular, regarding improving color reproducibility, as a method with a wide color reproduction area, there are an OLED with a three-color coating method of R (red), G (green), and B (blue), and a liquid crystal display device using a micro LED, a mini LED, or a quantum dot (QD) light source, a QD-OLED, etc. In order to further improve these color reproducibilities, attempts have been made to assemble a wavelength selective absorption filter.

[0009] As a wavelength-selective absorption filter, for example, Patent Document 1 discloses a color correction filter for a white organic electroluminescent light source, which includes: a resin; and 0.1 part by mass or more of a pigment having a maximum absorption wavelength in the range of 560 to 620 nm or 460 to 520 nm with respect to 100 parts by mass of the resin, and the water content is 0.5% by mass or less. According to the color correction filter for a white organic electroluminescent light source described in Patent Document 1, it is described that the color reproducibility of an organic EL display device using a white organic EL light source can be further improved, and the light resistance is also excellent.

[0010] Prior Art Documents

[0011] Patent Documents

[0012] Patent Document 1: International Publication No. 2019 / 189463 Summary of the Invention

[0013] Technical Problem to be Solved by the Invention

[0014] However, in the color correction filter (wavelength-selective absorption filter) for a white organic electroluminescent light source described in Patent Document 1 above, the adhesion between the substrate film (support) used for coating and forming the wavelength-selective absorption filter layer (color correction filter layer for a white organic EL light source) is low. Therefore, when assembling into various display devices, a process of transferring from the substrate film used in the above coating and forming process to other substrate films is required.

[0015] An object of the present invention is to provide a wavelength-selective absorption filter in which the substrate film and the wavelength-selective absorption filter layer in the wavelength-selective absorption filter exhibit excellent adhesion, and for example, can be assembled into a display device together with the substrate film for use.

[0016] Furthermore, an object of the present invention is to provide a liquid crystal display device and an organic electroluminescent display device including the above wavelength-selective absorption filter.

[0017] Means for Solving the Technical Problem

[0018] As a result of intensive studies by the present inventors in view of the above problems, it has been found that by using a polymer containing a carboxyl group as the resin constituting the wavelength-selective absorption filter layer, that is, by including a resin containing a carboxyl group in the wavelength-selective absorption filter layer, excellent adhesion between the wavelength-selective absorption filter layer and the substrate film can be obtained.

[0019] That is, the above problems are solved by the following means.

[0020] <1>

[0021] A wavelength-selective absorption filter having a substrate film and a wavelength-selective absorption filter layer disposed in contact with the substrate film. In the wavelength-selective absorption filter,

[0022] the wavelength-selective absorption filter layer includes: a resin containing a carboxyl group; and a pigment having a main absorption wavelength band at a wavelength of 460 to 520 nm in an amount of 0.1 part by mass or more based on 100 parts by mass of the resin.

[0023] <2>

[0024] The wavelength-selective absorption filter according to <1>, wherein

[0025] the pigment is a squaric acid-based pigment represented by the following general formula (1).

[0026] [Chemical formula 1]

[0027]

[0028] In the general formula (1), A and B each independently represent an aryl group which may have a substituent, a heterocyclic group which may have a substituent, or -CH=G. G represents a heterocyclic group which may have a substituent.

[0029] <3>

[0030] The wavelength-selective absorption filter according to <1> or <2>, wherein

[0031] the peeling force between the wavelength-selective absorption filter and the substrate film is 1 N / 25 mm or more.

[0032] <4>

[0033] A liquid crystal display device including the wavelength-selective absorption filter according to any one of <1> to <3>.

[0034] <5>

[0035] An organic electroluminescent display device including the wavelength-selective absorption filter according to any one of <1> to <3>.

[0036] In the present invention, the numerical range represented by "~" means a range including the numerical values described before and after it as the lower limit value and the upper limit value.

[0037] In the present invention, when there are a plurality of substituents, linking groups, structural units, etc. (hereinafter referred to as substituents, etc.) represented by specific symbols or formulas, or when a plurality of substituents, etc. are defined simultaneously, unless otherwise specified, each substituent, etc. may be the same as or different from one another. This also applies to the definition of the number of substituents, etc. Further, when a plurality of substituents, etc. are close to each other (especially when adjacent), unless otherwise specified, they may be linked to each other to form a ring. Moreover, rings, such as aliphatic rings, aromatic rings, and heterocyclic rings, may be further fused to form a fused ring.

[0038] In the present invention, unless otherwise specified, the components constituting the wavelength-selective absorption filter layer (a resin containing a carboxyl group, a pigment having a main absorption wavelength band at 460 to 520 nm, and other components that may be appropriately contained, etc.) may each be contained singly in the wavelength-selective absorption filter layer, or two or more of them may be contained.

[0039] In the present invention, the polymer may be either a chain polymerization polymer or a polycondensation polymer, and may also be either a homopolymer or a copolymer. Further, in the case of a copolymer, it may be any one of a random polymer, a block polymer, etc.

[0040] In the present invention, unless otherwise specified, regarding a double bond, when both E-type and Z-type exist in the molecule, it may be either one of them, or a mixture thereof.

[0041] In the present invention, the composition includes, in addition to a mixture with a constant component concentration (wherein each component is uniformly dispersed), a mixture in which the component concentration varies within a range that does not impair the target function.

[0042] In the present invention, “(meth)acrylate” means either or both of acrylate and methacrylate, “(meth)acrylic acid” means either or both of acrylic acid and methacrylic acid, and “(meth)acryloyl” means either or both of acryloyl and methacryloyl.

[0043] Advantages of the Invention

[0044] In the wavelength-selective absorption filter of the present invention, the substrate film and the wavelength-selective absorption filter layer in the wavelength-selective absorption filter exhibit excellent adhesion. Therefore, the wavelength-selective absorption filter of the present invention can be used, for example, by being assembled together with the substrate film into a display device.

[0045] Further, since the liquid crystal display device and the organic electroluminescent display device of the present invention directly include the wavelength-selective absorption filter of the present invention, during their manufacture, there is no need to transfer the wavelength-selective absorption filter layer to another substrate film, etc. and then assemble it into the display device, and the manufacturing (assembly) efficiency is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 FIG. Figure 1 is a schematic diagram showing an embodiment of a liquid crystal display device having a wavelength selective absorption filter of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0047] [Wavelength Selective Absorption Filter]

[0048] The wavelength selective absorption filter of the present invention (hereinafter, also simply referred to as "the filter of the present invention") has a substrate film and a wavelength selective absorption filter layer disposed in contact with the substrate film. In the wavelength selective absorption filter, the wavelength selective absorption filter layer contains: a resin containing a carboxyl group; and a pigment having a main absorption wavelength band at a wavelength of 460 to 520 nm contained in a specific ratio with respect to the resin.

[0049] The filter of the present invention can be used, for example, as a film for effectively blocking light of an unnecessary wavelength (light in a wavelength band other than RGB described later) from a backlight light source of a liquid crystal display device, and can be used as a film for effectively blocking light of an unnecessary wavelength (light in a wavelength band other than RGB described later) from a light source in an organic EL display device.

[0050] [Wavelength Selective Absorption Filter Layer]

[0051] <Pigment>

[0052] The pigment contained in the wavelength selective absorption filter layer is a pigment having a main absorption wavelength band at a wavelength of 460 to 520 nm (hereinafter, referred to as pigment A).

[0053] Details will be described later, but the wavelength selective absorption filter layer can further contain a pigment other than the pigment A.

[0054] Regarding the pigment A, as long as it has a main absorption wavelength band at a wavelength of 460 to 520 nm, there is no particular limitation, and various pigments can be used. The pigment A mostly exhibits fluorescence.

[0055] In the present invention, having a main absorption wavelength band at wavelengths XX to YY nm means that in the visible light absorption spectrum (wavelength region 380 to 750 nm), the wavelength showing the absorption maximum wavelength exists in the wavelength region XX to YY nm. Therefore, if the wavelength is within the above wavelength region, the entire absorption band including the wavelength may be within the above wavelength region or may extend outside the above wavelength region. And in the case where there are multiple absorption maximum wavelengths, as long as the absorption maximum wavelength showing the maximum absorbance exists within the wavelength region XX to YY nm, the absorption maximum wavelengths other than the absorption maximum wavelength showing the maximum absorbance (the absorption maximum wavelength showing a non-highest absorbance) may exist outside the wavelength region XX to YY nm.

[0056] As specific examples of the pigment A, for example, pyrrole methine (PM)-type, rhodamine (RH)-type, boron dipyrromethene (BODIPY)-type, squaraine (SQ)-type and other pigments can be cited.

[0057] For example, commercially available products such as FDB-007 (trade name, merocyanine pigment, manufactured by YAMADA CHEMICAL CO., LTD.) can also be preferably used as the pigment A.

[0058] In addition, pigments other than the pigment A can be appropriately contained within the range not impairing the effects of the present invention.

[0059] Among these, as the pigment A, squaraine pigments are preferred, and squaraine pigments represented by the following general formula (1) are more preferred.

[0060] In the present invention, in the pigments represented by the following general formulas, the cations exist in a delocalized manner and there are multiple tautomeric structures. Therefore, in the present invention, when at least one tautomeric structure of certain pigments is applicable to each general formula, the pigment is assumed to be a pigment represented by each general formula. Therefore, a pigment represented by a specific general formula can also be referred to as a pigment capable of representing at least one of its tautomeric structures by the specific general formula. In the present invention, regarding the pigments represented by the general formula, any tautomeric structure can be adopted as long as at least one of its tautomeric structures is applicable to the general formula.

[0061] [Chemical formula 2]

[0062]

[0063] In the general formula (1), A and B each independently represent an aryl group which may have a substituent, a heterocyclic group which may have a substituent, or -CH = G. G represents a heterocyclic group which may have a substituent.

[0064] In addition, the pigment represented by the above general formula (1) is the same as the squaric acid-based pigment represented by the general formula (1) described in paragraphs

[0016] to

[0024] of International Publication No. 2019 / 189463, and the preferred ranges are also the same. Therefore, regarding the definitions and preferred ranges of the respective substituents in the general formula (1), unless otherwise specified, the descriptions regarding the respective substituents of the pigment represented by the general formula (1) described in paragraphs

[0016] to

[0024] of International Publication No. 2019 / 189463 can be directly applied respectively.

[0065] This is also the same for the pigments represented by any one of the following general formulas (2) to (5). That is, the pigments represented by any one of the following general formulas (2) to (5) are the same as the squaric acid-based pigments represented by any one of the general formulas (2) to (5) described in paragraphs

[0025] to

[0045] of International Publication No. 2019 / 189463, and the preferred ranges are also the same. Therefore, regarding the definitions and preferred ranges of the respective substituents in the general formulas (2) to (5), unless otherwise specified, the descriptions regarding the respective substituents of the pigments represented by any one of the general formulas (2) to (5) described in paragraphs

[0025] to

[0045] of International Publication No. 2019 / 189463 can be directly applied respectively.

[0066] As a preferred embodiment of the pigment represented by the above general formula (1), a pigment represented by the following general formula (2) can be cited.

[0067] [Chemical formula 3]

[0068]

[0069] In the general formula (2), A 1 is the same as A in the general formula (1). Among them, a heterocyclic group of a 5-membered ring containing nitrogen is preferred.

[0070] The pigment represented by the above general formula (2) is preferably a pigment represented by any one of the following general formulas (3), (4), and (5).

[0071] [Chemical formula 4]

[0072]

[0073] In the general formula (3), R 1 and R 2 each independently represent a hydrogen atom or a substituent, and have the same meaning and the same preferred range as R 1 and R 2 in the above general formula (2).

[0074] In the general formula (3), B1 ~B 4 each independently represents a carbon atom or a nitrogen atom, which has the same meaning and preferred range as B in the above general formula (2). 1 ~B 4 each independently represents a carbon atom or a nitrogen atom, which has the same meaning and preferred range as B in the above general formula (2).

[0075] [Chemical formula 5]

[0076]

[0077] In general formula (4), R 1 and R 2 each independently represents a hydrogen atom or a substituent, which has the same meaning and preferred range as R in the above general formula (2). 1 and R 2 each independently represents a hydrogen atom or a substituent, which has the same meaning and preferred range as R in the above general formula (2).

[0078] In general formula (4), B 1 ~B 4 each independently represents a carbon atom or a nitrogen atom, which has the same meaning and preferred range as B in the above general formula (2). 1 ~B 4 each independently represents a carbon atom or a nitrogen atom, which has the same meaning and preferred range as B in the above general formula (2).

[0079] [Chemical formula 6]

[0080]

[0081] In general formula (5), R 1 and R 2 each independently represents a hydrogen atom or a substituent, which has the same meaning and preferred range as R in the above general formula (2). 1 and R 2 each independently represents a hydrogen atom or a substituent, which has the same meaning and preferred range as R in the above general formula (2).

[0082] In general formula (5), B 1 ~B 4 each independently represents a carbon atom or a nitrogen atom, which has the same meaning and preferred range as B in the above general formula (2). 1 ~B 4 each independently represents a carbon atom or a nitrogen atom, which has the same meaning and preferred range as B in the above general formula (2).

[0083] In the present invention, when a squarylium pigment is used as Pigment A, any squarylium pigment represented by any one of General Formulas (1) to (5) can be used without particular limitation. As examples thereof, for example, the compounds described in JP-A-2006-160618, WO 2004 / 005981, WO 2004 / 007447, Dyes and Pigment, 2001, 49, p. 161-179, WO 2008 / 090757, WO 2005 / 121098, and JP-A-2008-275726 can be cited.

[0084] As specific examples of the pigment represented by any one of General Formulas (1) to (5), the descriptions of the specific examples of the pigment represented by any one of General Formulas (1) to (5) described in paragraphs

[0047] to

[0055] of WO 2019 / 189463 can be directly applied.

[0085] As a preferred embodiment of the pigment represented by General Formula (1) above, a pigment represented by the following General Formula (6) can be cited.

[0086] [Chemical Formula 7]

[0087]

[0088] In General Formula (6), R 3 and R 4 each independently represent a hydrogen atom or a substituent, and have the same meaning and the same preferred range as R 3 and R 4 in General Formula (3) above.

[0089] In General Formula (6), A 2 is the same as A in General Formula (1). Among them, a nitrogen-containing 5-membered heterocyclic group is preferred.

[0090] The pigment represented by General Formula (6) above is preferably a pigment represented by any one of the following General Formulas (7), (8), and (9).

[0091] [Chemical Formula 8]

[0092]

[0093] In General Formula (7), R 3 and R 4 each independently represent a hydrogen atom or a substituent, and have the same meaning and the same preferred range as R 3 and R 4 in General Formula (3) above. Two Rs 3 and two Rs4 They may be the same or different respectively.

[0094] [Chemical Formula 9]

[0095]

[0096] In the general formula (8), R 3 and R 4 each independently represent a hydrogen atom or a substituent, which have the same meaning as R 3 and R 4 in the above general formula (3), and also have the same preferred ranges.

[0097] In the general formula (8), R 5 and R 6 each independently represent a hydrogen atom or a substituent, which have the same meaning as R 5 and R 6 in the above general formula (4), and also have the same preferred ranges.

[0098] [Chemical Formula 10]

[0099]

[0100] In the general formula (9), R 3 and R 4 each independently represent a hydrogen atom or a substituent, which have the same meaning as R 3 and R 4 in the above general formula (3), and also have the same preferred ranges.

[0101] In the general formula (9), R 7 and R 8 each independently represent a hydrogen atom or a substituent, which have the same meaning as R 7 and R 8 in the above general formula (5), and also have the same preferred ranges.

[0102] In the present invention, when using squarylium dyes as Dye B, as the squarylium dyes, any squarylium dyes represented by any one of the general formulas (6) to (9) can be used without particular limitation. As examples thereof, for example, the compounds described in Japanese Patent Application Laid-Open No. 2002-097383 and Japanese Patent Application Laid-Open No. 2015-068945 can be cited.

[0103] Moreover, as specific examples of the dyes represented by any one of the general formulas (6) to (9), the descriptions of the specific examples of the dyes represented by any one of the general formulas (6) to (9) described in paragraphs

[0067] to

[0070] of International Publication No. 2019 / 189463 can be directly applied.

[0104] Based on 100 parts by mass of the resin constituting the wavelength-selective absorption filter layer, the total content of the pigments having a main absorption wavelength band at wavelengths of 460 to 520 nm in the wavelength-selective absorption filter layer is 0.10 part by mass or more, preferably 0.15 part by mass or more, more preferably 0.20 part by mass or more, further preferably 0.25 part by mass or more, and particularly preferably 0.30 part by mass or more.

[0105] Moreover, based on 100 parts by mass of the resin constituting the wavelength-selective absorption filter layer, the total content of the pigments having a main absorption wavelength band at wavelengths of 460 to 520 nm in the wavelength-selective absorption filter layer is generally 1 part by mass or less, preferably 0.60 part by mass or less, and more preferably 0.45 part by mass or less.

[0106] That is, based on 100 parts by mass of the resin constituting the wavelength-selective absorption filter layer, the total content of the pigments having a main absorption wavelength band at wavelengths of 460 to 520 nm in the wavelength-selective absorption filter layer is preferably 0.10 to 1 part by mass, more preferably 0.15 to 1 part by mass, further preferably 0.20 to 0.60 part by mass, particularly preferably 0.25 to 0.60 part by mass, and preferably 0.30 to 0.45 part by mass.

[0107] As the pigments for use in the present invention, in addition to the above-described Pigment A, one or more fluorescent pigments (pigments of the second mode) whose main absorption wavelength band is in a wavelength band other than RGB and whose main emission wavelength band is in a wavelength band corresponding to the wavelength band of RGB can also be used simultaneously.

[0108] In the present invention, as the wavelength bands other than RGB, for example, wavelength bands of 430 nm or less (for example, 380 nm to 430 nm), 480 nm to 510 nm, or 560 nm to 620 nm (preferably 610 nm or less) can be cited. And, as the wavelength bands of RGB, for example, wavelength bands of 430 nm to 480 nm, 510 nm to 580 nm (preferably less than 560 nm), or 610 nm or more (for example, 610 nm to 650 nm, preferably more than 620 nm and 650 nm or less) can be cited.

[0109] In the present invention, the main absorption wavelength band being in a wavelength band other than RGB means that in the visible light absorption spectrum (wavelength region 380 to 750 nm), the wavelength showing the highest absorbance (maximum absorbance) among the absorption maximum wavelengths exists in any one of the wavelength bands other than RGB. And the main emission wavelength band being in a wavelength band corresponding to the wavelength bands of RGB means that in the visible light emission spectrum (wavelength region 380 to 750 nm), the wavelength showing the highest luminance (maximum luminance) among the maximum emission wavelengths exists in any one of the wavelength bands of RGB.

[0110] As the pigment of the second aspect described above, as long as it has the above characteristics, there is no particular limitation. However, for example, anthracene-based, anthraquinone-based, arylmethine-based, azo-based, azomethine-based, biman-based, coumarin-based, 1,5-diazabicyclo[3.3.0]octadiene-based, diketo-pyrrole-based, naphthalenol-imine-based, naphthalimide-based, perylene-based, phenolphthalein-based, pyrrole methine-based, pyran-based, pyrene-based, porphycene-based, porphyrin-based, quinacridone-based, rhodamine-based, rubrene-based, and stilbene-based fluorescent pigments can be cited.

[0111] Preferably, a combination of two or more fluorescent pigments selected from perylene-based, azo-based, pyrrole methine-based, pyran-based, and coumarin-based fluorescent pigments is selected, and more preferably, a combination of two or more fluorescent pigments selected from perylene-based, pyrrole methine-based, pyran-based, and coumarin-based fluorescent pigments is selected.

[0112] <Resin>

[0113] The above wavelength-selective absorption filter layer contains a resin containing a carboxyl group.

[0114] That is, the above wavelength-selective absorption filter layer contains a resin composed of a polymer containing a carboxyl group (hereinafter, also referred to as "polymer containing a carboxyl group.") as a matrix resin.

[0115] (Polymer containing a carboxyl group)

[0116] The polymer containing a carboxyl group may also have acid groups other than the carboxyl group. Examples of the acid groups other than the carboxyl group include phenolic hydroxyl groups, phosphoric acid groups, and sulfonic acid groups.

[0117] When the polymer containing a carboxyl group is a copolymer, the structure of the polymer may be a random polymer or an ordered polymer such as a block polymer.

[0118] <<Structural unit having a carboxyl group>>

[0119] The polymer containing a carboxyl group preferably has a structural unit having a carboxyl group.

[0120] Examples of the structural unit having a carboxyl group include structural units derived from (meth)acrylic acid, crotonic acid, itaconic acid, maleic acid, or fumaric acid. Among them, a structural unit derived from (meth)acrylic acid is preferred.

[0121] When the total of all the structural units of the polymer containing a carboxyl group is set to 100 mol%, the content of the structural unit having a carboxyl group in the polymer containing a carboxyl group is preferably 1 to 100 mol%, more preferably 3 to 65 mol%, still more preferably 5 to 45 mol%, and particularly preferably 10 to 45 mol%.

[0122] The structural unit having a carboxyl group may be used alone or two or more thereof may be used simultaneously.

[0123] <<Structural unit having an aromatic ring>>

[0124] In addition to the above structural units, the polymer containing a carboxyl group preferably has a structural unit having an aromatic ring (preferably an aromatic hydrocarbon ring). Examples thereof include structural units derived from (meth)acrylate having an aromatic ring (specifically, benzyl (meth)acrylate, phenethyl (meth)acrylate, or phenoxyethyl (meth)acrylate, etc.) and styrene.

[0125] When the total of all the structural units of the polymer containing a carboxyl group is set to 100 mol%, the content of the structural unit having an aromatic ring in the polymer containing a carboxyl group is preferably 0 to 97 mol%, more preferably 0 to 95 mol%, still more preferably 0 to 90 mol%.

[0126] The structural unit having an aromatic ring may be used alone or two or more thereof may be used simultaneously.

[0127] <<Structural unit having an alicyclic structure>>

[0128] In addition to the above structural units, the polymer containing a carboxyl group preferably has a structural unit having an alicyclic structure.

[0129] As an alicyclic structure, for example, tricyclo[5.2.1.0 2,6 decane ring structure (also referred to as tetrahydrodicyclopentadiene. The monovalent group is dicyclopentyl), tricyclo[5.2.1.0 2,6 dec-3-ene ring structure (also referred to as 5,6-dihydrodicyclopentadiene. The monovalent group is dicyclopentenyl), isobornylane ring structure (the monovalent group is isobornyl), adamantane ring structure (the monovalent group is adamantyl), and cyclohexane ring structure (the monovalent group is cyclohexyl).

[0130] As a structural unit having an alicyclic structure, for example, a structural unit derived from an (meth)acrylate having an alicyclic structure can be cited. Specifically, structural units derived from dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, cyclohexyl (meth)acrylate, etc. can be cited.

[0131] When the total of all structural units of the carboxyl group-containing polymer is set to 100 mol%, the content of the structural unit having an alicyclic structure in the carboxyl group-containing polymer is preferably 0 to 97 mol%, more preferably 0 to 95 mol%, and further preferably 0 to 90 mol%.

[0132] The structural unit having an alicyclic structure can be used alone or two or more thereof can be used simultaneously.

[0133] <<Other structural units>>

[0134] In addition to the above structural units, the carboxyl group-containing polymer can have other structural units.

[0135] As the above other structural units, for example, a structural unit derived from methyl (meth)acrylate can be cited.

[0136] When the total of all structural units of the carboxyl group-containing polymer is set to 100 mol%, the content of other structural units in the carboxyl group-containing polymer is preferably 0 to 70 mol%, more preferably 0 to 50 mol%, and further preferably 0 to 20 mol%.

[0137] Other structural units can be used alone or two or more thereof can be used simultaneously.

[0138] Among them, the carboxyl group-containing polymer preferably has at least one of the above structural units having an aromatic ring and the structural unit having an alicyclic structure in addition to the above structural units having a carboxyl group. From the viewpoint of further improving the adhesion between the wavelength-selective absorption filter layer and the substrate film, it is more preferable to have at least the above structural unit having an alicyclic structure in addition to the above structural units having a carboxyl group.

[0139] <Other components>

[0140] In addition to the above-mentioned pigment and matrix resin, the wavelength-selective absorption filter layer may further contain a polarization degree improver, a fading inhibitor, a matting agent, a leveling agent, etc.

[0141] (Polarization degree improver)

[0142] The wavelength-selective absorption filter layer preferably contains a polarization degree improver. By quenching the fluorescence emitted by the pigment using the polarization degree improver, it is possible to improve the polarization degree of the polarizing plate that the organic EL display device has for preventing the entry of external light and the like.

[0143] The polarization degree improver for use in the present invention is preferably a donor-type quencher or an acceptor-type quencher.

[0144] The donor-type quencher for use in the present invention inactivates the excited-state pigment to the ground state by supplying electrons to the lower-energy SOMO among the two SOMOs of the excited-state pigment and then receiving electrons from the higher-energy SOMO of the pigment.

[0145] The acceptor-type quencher for use in the present invention inactivates the excited-state pigment to the ground state by receiving electrons from the higher-energy SOMO among the two SOMOs of the excited-state pigment and then supplying electrons to the lower-energy SOMO of the pigment.

[0146] As the donor-type quencher and acceptor-type quencher for use in the present invention, the descriptions related to the donor-type quencher and acceptor-type quencher and the descriptions of their specific examples described in paragraphs

[0104] to

[0220] of International Publication No. 2019 / 189463 can be directly applied.

[0147] The content of the polarization degree improver in the wavelength-selective absorption filter layer is preferably 0 to 6% by mass, more preferably 0.1 to 5% by mass, and further preferably 0.3 to 4.5% by mass. By controlling the addition amount of the polarization degree improver below the above upper limit value, side effects such as discoloration of the wavelength-selective absorption filter layer will not occur, and the polarization degree can be improved.

[0148] (Polarization degree improver-incorporated pigment)

[0149] The polarization degree improver for use in the present invention is also preferably covalently linked to the pigment via a linking group as needed to form a polarization degree improver-incorporated pigment. The pigment in this form is also included in the squaric acid-based pigment of the general formula (1) defined in the present invention.

[0150] The energy levels of the pigment part and the polarization degree improver part of the polarization degree improver - incorporated pigment of the present invention can be calculated by the same method as the calculation method of the energy levels of the aforementioned pigment and polarization degree improver. In addition, in the measurement of the potential, two oxidation potentials are detected from the polarization degree improver - incorporated pigment used in the present invention. However, the value close to the oxidation potential in the pigment without the incorporated polarization degree improver is set as the oxidation potential of the pigment part, and the value far from the oxidation potential is set as the oxidation potential of the polarization degree improver part.

[0151] As a specific example of the polarization degree improver - incorporated pigment used in the present invention, the descriptions related to the polarization degree improver - incorporated pigment and the descriptions of their specific examples recorded in paragraphs

[0223] to

[0234] of International Publication No. 2019 / 189463 can be directly applied.

[0152] When using the polarization degree improver - incorporated pigment, the content of the polarization degree improver - incorporated pigment in the above - mentioned wavelength - selective absorption filter layer is set to the content of the pigment having a main absorption wavelength band at a wavelength of 460 to 520 nm in the above - mentioned wavelength - selective absorption filter layer. With respect to 100 parts by mass of the resin constituting the above - mentioned wavelength - selective absorption filter layer, the content of this polarization degree improver - incorporated pigment may be 0.1 part by mass or more.

[0153] (Anti - fading agent)

[0154] The above - mentioned wavelength - selective absorption filter layer preferably contains an anti - fading agent. As the anti - fading agent used in the present invention, antioxidants described in paragraphs

[0143] to

[0165] of International Publication No. 2015 / 005398, radical scavengers described in paragraphs

[0166] to

[0199] of International Publication No. 2015 / 005398, and deterioration inhibitors described in paragraphs

[0205] to

[0206] of International Publication No. 2015 / 005398 can be used.

[0155] Moreover, as the anti - fading agent used in the present invention, compounds represented by general formula (IV) and compounds represented by general formula [III] described in paragraphs

[0237] to

[0251] of International Publication No. 2019 / 189463 can be used.

[0156] The content of the anti - fading agent in the above - mentioned wavelength - selective absorption filter layer is preferably 0 to 5% by mass, more preferably 0 to 3% by mass, and further preferably 0 to 2% by mass. By controlling the addition amount of the anti - fading agent below the above upper limit value, side effects such as discoloration of the above - mentioned wavelength - selective absorption filter layer will not occur, and the fastness of the pigment can be improved.

[0157] (Leveling agent)

[0158] In the above-described wavelength-selective absorption filter layer, a leveling agent (surfactant) can be appropriately mixed. As the leveling agent, conventionally known compounds can be cited, but fluorosurfactants are particularly preferred. Specifically, for example, the compounds described in paragraphs

[0028] to

[0056] of the specification of Japanese Patent Application Laid-Open No. 2001-330725 can be cited, and copolymers including a structural unit having a fluorosubstituted alkyl group and a structural unit derived from an alkyl (meth)acrylate described in paragraph

[0054] of the specification of Japanese Patent Application Laid-Open No. 2001-330725 are also preferably cited.

[0159] The content of the leveling agent in the above-described wavelength-selective absorption filter layer can be appropriately adjusted according to the purpose.

[0160] In addition to the above-described respective components, the above-described wavelength-selective absorption filter layer may further contain a low molecular weight plasticizer, an oligomer plasticizer, a delay regulator, an ultraviolet absorber, a deterioration inhibitor, a peeling promoter, an infrared absorber, an antioxidant, a filler, a compatibilizer, and the like.

[0161] [Substrate film]

[0162] Regarding the substrate film in the filter of the present invention, it will be described in the following description related to the method for manufacturing a wavelength-selective absorption filter.

[0163] <Method for manufacturing a wavelength-selective absorption filter>

[0164] The above-described wavelength-selective absorption filter layer can be produced by a method of forming a coating on a substrate film according to a conventional method (coating method), and stretching can also be appropriately combined. Thereby, the filter of the present invention configured to be in contact with the wavelength-selective absorption filter layer on the substrate film can be produced.

[0165] (Coating method)

[0166] In the coating method, a solution of a material for forming a wavelength-selective absorption filter layer (hereinafter, also referred to as "filter material") is coated on a substrate film to form a coating. For the surface of the coating opposite to the surface in contact with the substrate film, other components can be laminated via an adhesive layer in a subsequent process. In addition, stretching can be appropriately performed together with the substrate film in a state where a polymer solution or a coating is laminated on the substrate film.

[0167] From the viewpoints of being able to dissolve or disperse the filter material; easily becoming a uniform planar shape in the coating process and the drying process; being able to ensure liquid storage stability; having an appropriate saturation vapor pressure, etc., the solvent used in the solution of the filter material can be appropriately selected.

[0168] -Addition of pigment-

[0169] Regarding the timing of adding the above pigments to the filter material, there is no particular limitation as long as it is added at the time of film formation. For example, it can be added at the time of synthesis of the base resin, or it can be mixed with the filter material when preparing the coating solution of the filter material.

[0170] -Base film-

[0171] The film thickness of the base film for forming the above wavelength-selective absorption filter layer by a coating method or the like is preferably 5 to 100 μm, more preferably 10 to 75 μm, and still more preferably 15 to 55 μm. If the film thickness is above the above preferred lower limit value (for example, 5 μm or more), it is easy to ensure sufficient mechanical strength and it is not easy to cause failures such as curling, wrinkling, and buckling, so it is preferred. Also, if the film thickness is below the above preferred upper limit value (for example, 100 μm or less), in the case of storing the multi-layer film including the above wavelength-selective absorption filter layer and the base film in the form of a long strip roll, it is easy to adjust the surface pressure applied to the multi-layer film within an appropriate range and it is difficult to cause adhesion failures, so it is preferred.

[0172] The surface energy of the base film is not particularly limited, but by adjusting the correlation between the surface energy of the filter material and the coating solution and the surface energy of the surface of the base film on the side where the wavelength-selective absorption filter layer is formed, the adhesion (adhesive force) between the wavelength-selective absorption filter layer and the base film can be adjusted. If the surface energy difference is reduced, the adhesive force tends to increase, and if the surface energy difference is increased, the adhesive force tends to decrease, and the surface energy difference can be appropriately set. In the present invention, it is preferred to reduce the surface energy difference.

[0173] The surface energy of the base film can be calculated by Owens' method based on the contact angle values of water and diiodomethane. Regarding the measurement of the contact angle, for example, DM901 (manufactured by Kyowa Interface Science Co., Ltd., contact angle measuring instrument) can be used.

[0174] The surface energy of the surface of the base film on the side where the wavelength-selective absorption filter layer is formed is preferably 41.0 to 48.0 mN / m, more preferably 42.0 to 48.0 mN / m. If the surface energy is 41.0 mN / m or more, the thickness uniformity of the wavelength-selective absorption filter layer can be improved, so it is preferred. If it is 48.0 mN / m or less, it is preferred from the viewpoint of the adhesion between the wavelength-selective absorption filter layer and the base film.

[0175] Moreover, the surface unevenness of the base material film is not particularly limited, but it can be adjusted according to the correlation between the surface energy, hardness, and surface unevenness of the surface of the wavelength-selective absorption filter layer and the surface energy and hardness of the surface of the base material film on the side opposite to the side where the wavelength-selective absorption filter layer is formed. For example, it can be adjusted to prevent adhesion failure when storing the wavelength-selective absorption filter (multilayer thin film) of the present invention in the form of a long roll. If the surface unevenness is increased, the adhesion failure tends to be suppressed. If the surface unevenness is decreased, the surface unevenness of the wavelength-selective absorption filter decreases, and the haze of the wavelength-selective absorption filter decreases, which can be appropriately set.

[0176] As such a base material film, a thin film made of a commonly used material or a commonly used thin film can be appropriately used. Specific materials constituting the base material film include polyester-based polymers such as polyethylene terephthalate, olefin-based polymers, cycloolefin-based polymers, (meth)acrylic-based polymers, cellulose-based polymers, polyamide-based polymers, etc. Moreover, in order to adjust the surface properties of the base material film, surface treatment can be appropriately performed. For example, to increase the surface energy, corona treatment, room-temperature plasma treatment, saponification treatment, etc. can be performed. To reduce the surface energy, silicone treatment, fluorine treatment, olefin treatment, etc. can be performed.

[0177] -Peeling force between the wavelength-selective absorption filter layer and the base material film-

[0178] In the case where the above wavelength-selective absorption filter layer is formed by a coating method, the peeling force between the wavelength-selective absorption filter layer and the base material film can be controlled by adjusting the filter material (the material forming the wavelength-selective absorption filter layer), the material of the base material film, the internal strain of the wavelength-selective absorption filter layer, etc.

[0179] In the present invention, according to JIS (Japanese Industrial Standards) Z-0237 (2022), through the test of peeling the base material film along the 90° direction (90-degree peeling test), the peeling force measured under the conditions of a measurement temperature of 25°C, a relative humidity of 60%, a load cell of 50 N, and a peeling speed of 300 mm / minute is preferably 1 N / 25 mm or more, more preferably 5 N / 25 mm or more, further preferably 8 N / 25 mm or more, and particularly preferably no peeling under the above peeling conditions. If it is 1 N / 25 mm or more, when directly assembling the filter of the present invention into an organic EL display device or a liquid crystal display device for use, poor adhesion during the manufacturing process and / or use of the display device can be prevented.

[0180] In addition, the detailed content of the peeling test is described in the examples described later.

[0181] Moreover, the non-peeling under the above peeling conditions means that there is no peeling between the wavelength-selective absorption filter layer and the base film, partial peeling of the adhesive used when bonding the wavelength-selective absorption filter layer to the glass substrate for the peeling test, or breakage of the wavelength-selective absorption filter itself.

[0182] <Film thickness of the wavelength-selective absorption filter layer>

[0183] The film thickness of the above wavelength-selective absorption filter layer is preferably 1 to 18 μm, more preferably 1 to 12 μm, and even more preferably 1 to 8 μm. By adding a pigment to the wavelength-selective absorption filter layer with such a film thickness at a specified concentration, fluorescence emitted by the pigment can be further suppressed. Also, the effects of the quencher and / or anti-fading agent are more easily manifested.

[0184] In the present invention, a film thickness of 1 to 18 μm means that the thickness of the filter is within the range of 1 to 18 μm regardless of the measurement position. The same applies to film thicknesses of 1 to 12 μm and 1 to 8 μm. The film thickness can be measured using a micrometer manufactured by ANRITSU CORPORATION or the like.

[0185] <Absorbance of the wavelength-selective absorption filter layer>

[0186] In the above wavelength-selective absorption filter layer, the absorbance at a wavelength of 500 nm is preferably 0.05 or more and 4.0 or less. More preferably, it is 0.01 or more and 3.0 or less, and even more preferably, it is 0.1 or more and 2.0 or less.

[0187] By assembling the filter of the present invention with the absorbance of the wavelength-selective absorption filter layer adjusted within the above range into an organic EL display device or a liquid crystal display device, better color reproducibility display performance can be obtained.

[0188] The absorbance of the above wavelength-selective absorption filter layer can be adjusted according to the type and addition amount of the pigment.

[0189] <Water content of the wavelength-selective absorption filter layer>

[0190] Regarding the water content of the above wavelength-selective absorption filter layer, from the viewpoint of durability, regardless of the film thickness, it is preferably 0.5 mass% or less, and more preferably 0.3 mass% or less. In the present invention, the "water content" is a value measured under the conditions of 25°C and a relative humidity of 80%.

[0191] In this specification, the water content of the above-described wavelength-selective absorption filter layer can be measured using a sample with an increased film thickness as needed. After the sample is conditioned for 24 hours or more, it can be measured by the Karl Fischer method using a moisture meter, a sample drying device "CA-03" and "VA-05" (both manufactured by Mitsubishi Chemical Corporation), and the water content (g) is divided by the sample mass (g, including the water content) to calculate.

[0192] <Treatment of Wavelength-Selective Absorption Filter>

[0193] Preferably, a hydrophilic treatment is performed on the wavelength-selective absorption filter obtained in the above manner by a glow discharge treatment, a corona discharge treatment, an alkali saponification treatment, etc. according to a conventional method, and a corona discharge treatment is most preferably used. It is also preferable to apply the methods disclosed in Japanese Patent Laid-Open No. 6-094915 or Japanese Patent Laid-Open No. 6-118232, etc.

[0194] In addition, as needed, a heat treatment process, a superheated steam contact process, an organic solvent contact process, etc. can be performed on the obtained wavelength-selective absorption filter. And surface treatment can be appropriately performed.

[0195] [Liquid Crystal Display Device]

[0196] The liquid crystal display device of the present invention includes the wavelength-selective absorption filter of the present invention.

[0197] In the liquid crystal display device of the present invention, as described later, the wavelength-selective absorption filter of the present invention can be used as at least one of a polarizer protective film and an adhesive layer, and can also be included in a backlight unit used in the liquid crystal display device.

[0198] The liquid crystal display device preferably includes a wavelength-selective absorption filter, a polarizer including a polarizer and a polarizer protective film, an adhesive layer, and a liquid crystal cell. Preferably, the polarizer is attached to the liquid crystal cell via the adhesive layer. In this liquid crystal display device, the wavelength-selective absorption filter can also serve as a polarizer protective film or an adhesive layer. That is, the liquid crystal display device is divided into the following cases: including a polarizer including a polarizer and a wavelength-selective absorption filter (polarizer protective film), an adhesive layer, and a liquid crystal cell; and including a polarizer including a polarizer and a polarizer protective film, a wavelength-selective absorption filter (adhesive layer), and a liquid crystal cell.

[0199] Figure 1 is a schematic diagram showing an example of the liquid crystal display device of the present invention. In Figure 1In this case, the liquid crystal display device 10 includes a liquid crystal cell having a liquid crystal layer 5 and upper and lower liquid crystal cells disposed above and below the liquid crystal layer, an upper electrode substrate 3 and a lower electrode substrate 6 of the liquid crystal cell, and upper and lower polarizers 1 and 8 disposed on both sides of the liquid crystal cell. A color filter layer may be laminated on the upper electrode substrate 3 or the lower electrode substrate 6. A backlight is disposed on the back surface of the liquid crystal display device 10. As the light source of the backlight, the light source described in the foregoing backlight unit can be used.

[0200] The upper polarizer 1 and the lower polarizer 8 each have a structure laminated in such a manner that a polarizer is sandwiched between two polarizer protective films. It is preferable that at least one polarizer of the liquid crystal display device 10 is a polarizer including the wavelength selective absorption filter of the present invention.

[0201] Further, in the liquid crystal display device 10, the liquid crystal cell and the polarizer (upper polarizer 1 and / or lower polarizer 8) may be bonded via an adhesive layer (not shown). In this case, the wavelength selective absorption filter of the present invention can also serve as the aforementioned adhesive layer.

[0202] The liquid crystal display device 10 includes a direct-view image type, an image projection type, or a light modulation type. An active matrix liquid crystal display device using a three-terminal or two-terminal semiconductor element such as TFT or MIM (Metal-Insulator-Metal) is effective in the present invention. Of course, a passive matrix liquid crystal display device typified by an STN (Super Twisted Nematic) mode called time-division driving is also effective.

[0203] When the wavelength selective absorption filter of the present invention is included in the backlight unit, the polarizer of the liquid crystal display device may be a general polarizer (a polarizer not including the wavelength selective absorption filter of the present invention) or a polarizer including the light absorption filter of the present invention. Further, the adhesive layer may be a general adhesive layer (not the wavelength selective absorption filter of the present invention) or an adhesive layer based on the wavelength selective absorption filter of the present invention.

[0204] The liquid crystal display device of the IPS (In Plane Switching) mode described in paragraphs

[0128] to

[0136] of Japanese Patent Application Laid-Open No. 2010-102296 is preferably used as the liquid crystal display device of the present invention except that the wavelength selective absorption filter of the present invention is used. That is, as the liquid crystal display device of the present invention, except for including the wavelength selective absorption filter of the present invention as described above, the description of the liquid crystal display device of the IPS mode described in Japanese Patent Application Laid-Open No. 2010-102296 can be preferably applied.

[0205] <Polarizer>

[0206] The polarizer used in the present invention includes a polarizer and at least one polarizer protective film.

[0207] The polarizer used in the present invention preferably has a polarizer and polarizer protective films on both sides of the polarizer, and more preferably includes the wavelength-selective absorption filter of the present invention as a polarizer protective film on at least one side. A general polarizer protective film can be provided on the side of the polarizer opposite to the side having the wavelength-selective absorption filter (the polarizer protective film of the present invention).

[0208] The film thickness of the polarizer protective film is generally preferably 5 to 120 μm, more preferably 10 to 100 μm. Since it is not easy to cause display unevenness after high temperature and high humidity over time when the thin film is assembled into a liquid crystal display device, it is preferred. On the other hand, if it is too thin, it is difficult to stably convey during the manufacture of the thin film and the production of the polarizer. When the wavelength-selective absorption filter of the present invention also serves as a polarizer protective film, the thickness of the wavelength-selective absorption filter preferably satisfies the above range.

[0209] - Performance of the polarizer -

[0210] The degree of polarization of the polarizer used in the present invention is preferably 99.950% or more, more preferably 99.970% or more, and most preferably 99.990% or more.

[0211] In the present invention, for the degree of polarization of the polarizer, an automatic polarizing film measuring device: VAP-7070 (trade name, manufactured by JASCO Corporation) is used, and it is calculated by the following formula based on the orthogonal transmittance and parallel transmittance measured at a wavelength of 380 to 700 nm.

[0212] Degree of polarization (%) = [(parallel transmittance - orthogonal transmittance) / (orthogonal transmittance + parallel transmittance)] 1 / 2 ×100

[0213] The degree of polarization can be measured in the following manner. Two samples (5 cm × 5 cm) with a polarizer attached to glass via an adhesive are prepared. Regarding the orthogonal transmittance and parallel transmittance, the glass side of the sample is set facing the light source and measured. The two samples are measured, and their averages are used as the orthogonal transmittance and parallel transmittance respectively. When studying the influence of the polarizer protective film on the degree of polarization, the polarizer protective film to be evaluated is usually arranged and attached to the glass side.

[0214] Regarding other preferred optical properties, etc. of the polarizer used in the present invention, they are described in paragraphs

[0238] to

[0255] of Japanese Patent Laid-Open No. 2007-086748, and it is preferred to satisfy these properties.

[0215] -Shape, Structure-

[0216] Regarding the shape of the polarizer used in the present invention, it includes not only a polarizer in the form of a thin film sheet cut into a size that can be directly assembled into a liquid crystal display device, but also a polarizer produced by continuous production and made into a long strip shape and rolled into a roll (for example, a roll length of 2500 m or more or 3900 m or more). For use in a large-screen liquid crystal display device, the width of the polarizer is preferably set to 1470 mm or more.

[0217] The polarizer used in the present invention is composed of a polarizer and at least one polarizer protective film, but it is also preferably further formed by laminating a release film on the surface of one side of the polarizer.

[0218] The release film is used for the purpose of protecting the polarizer when the polarizer is shipped from the factory, during product inspection, etc. The release film is used for the purpose of covering the adhesive layer adhered to the liquid crystal panel, and is used for adhering the polarizer to the surface side of the liquid crystal panel.

[0219] (Polarizer)

[0220] The polarizer used in the present invention will be described.

[0221] As the polarizer that can be used in the polarizer of the present invention, it is preferably composed of polyvinyl alcohol (PVA) and dichroic molecules, but it can also be used as described in Japanese Patent Laid-Open No. 11-248937, a polyvinylene-based polarizer obtained by dehydrating and dechlorinating PVA and polyvinyl chloride to form a polyene structure and orienting it.

[0222] -Film Thickness of Polarizer-

[0223] The film thickness of the thin film before stretching of the polarizer is not particularly limited, but from the viewpoints of maintaining the stability of the thin film and the uniformity of stretching, it is preferably 1 μm to 1 mm, and particularly preferably 5 to 200 μm. And, as described in Japanese Patent Laid-Open No. 2002-236212, a thin PVA film such that the stress generated when stretched 4 to 6 times in water is 10 N or less can be used.

[0224] -Manufacturing Method of Polarizer-

[0225] The manufacturing method of the polarizer is not particularly limited. However, for example, it is preferably formed by thinning the above-mentioned PVA and then introducing dichroic molecules. The manufacturing of the PVA film can be carried out with reference to the methods described in

[0213] to

[0237] of Japanese Patent Application Laid-Open No. 2007-086748, Japanese Patent No. 3342516, Japanese Patent Application Laid-Open No. 09-328593, Japanese Patent Application Laid-Open No. 2001-302817, Japanese Patent Application Laid-Open No. 2002-144401, etc.

[0226] (Laminating method of polarizer and polarizer protective film)

[0227] The polarizer for the present invention is manufactured by bonding (laminating) at least one polarizer protective film (preferably the wavelength selective absorption filter of the present invention) to at least one surface of the above-mentioned polarizer.

[0228] It is preferably manufactured by the following method: subject the polarizer protective film to alkali treatment, and bond it to both surfaces of the polarizer made by impregnating and stretching a polyvinyl alcohol film in an iodine solution using a fully saponified polyvinyl alcohol aqueous solution.

[0229] As the adhesive for bonding the treated surface of the above-mentioned polarizer protective film to the polarizer, for example, polyvinyl alcohol-based adhesives such as polyvinyl alcohol and polyvinyl butyral, and vinyl-based latexes such as butyl acrylate can be cited.

[0230] In the polarizer for the present invention, the polarizer protective film and the above-mentioned polarizer are preferably laminated in such a way that the transmission axis of the polarizer is substantially parallel, orthogonal or at 45° to the slow axis of the above-mentioned polarizer protective film.

[0231] Regarding the measurement of the slow axis, it can be measured by various known methods. For example, it can be carried out using a birefringence meter (manufactured by KOBRADH, Oji Scientific Instruments Co., Ltd.).

[0232] Here, substantially parallel means that the direction of the main refractive index nx of the polarizer protective film intersects with the direction of the transmission axis of the polarizer at an angle with a deviation of within ±5°, preferably within ±1°, and more preferably within ±0.5°. If the intersection angle is within 1°, the polarization degree performance under crossed polarizers of the polarizer is not easily reduced, and light leakage is not likely to occur, so it is preferred.

[0233] The same applies to substantially orthogonal or 45° cases. That the direction of the principal refractive index nx is orthogonal or at 45° to the direction of the transmission axis means that the angle at which the direction of the principal refractive index nx intersects the direction of the transmission axis is within the range of ±5° of the strict angles related to orthogonality and 45°, and the error from the strict angle is preferably within the range of ±1°, more preferably within the range of ±0.5°.

[0234] (Functionalization of polarizing plate)

[0235] The polarizing plate used in the present invention can also preferably be used as a functionalized polarizing plate laminated with an optical film having functional layers such as an antireflection film, a brightness enhancement film, a hard coat, a forward scattering layer, an antiglare (anti-reflection) layer, an antifouling layer, and an antistatic layer for improving the visual recognition of a display. Regarding the antireflection film, the brightness enhancement film, other functional optical films, the hard coat, the forward scattering layer, and the antiglare layer for functionalization, there are descriptions in paragraphs

[0257] to

[0276] of Japanese Patent Application Laid-Open No. 2007-086748, and a functionalized polarizing plate can be produced based on these descriptions.

[0236] The polarizing plate of the present invention only needs to include the wavelength-selective absorption filter of the present invention, and preferably includes the wavelength-selective absorption filter of the present invention as a polarizing plate protective film on at least one surface of the polarizer, and more preferably includes the wavelength-selective absorption filter of the present invention as a polarizing plate protective film with the substrate film facing the polarizer side.

[0237] As the polarizing plate of the present invention, except for including the wavelength-selective absorption filter of the present invention, the descriptions related to the polarizing plate used in the above-mentioned present invention can be applied.

[0238] <Adhesive layer>

[0239] In the liquid crystal display device of the present invention, it is preferable that the polarizing plate is attached to the liquid crystal cell via an adhesive layer. The wavelength-selective absorption filter of the present invention can also serve as the above-mentioned adhesive layer, and more preferably, the wavelength-selective absorption layer in the wavelength-selective absorption filter of the present invention serves as the above-mentioned adhesive layer, and is included with the substrate film facing the polarizing plate side. When the wavelength-selective absorption filter of the present invention does not also serve as an adhesive layer, a general adhesive layer can be used as the adhesive layer.

[0240] As the adhesive layer, as long as it can attach the polarizing plate to the liquid crystal cell, there is no particular limitation, but for example, acrylic, urethane, polyisobutene, etc. are preferred.

[0241] When the wavelength-selective absorption filter of the present invention also serves as an adhesive layer, the adhesive layer contains the above-mentioned pigment and the above-mentioned resin, and further contains a crosslinking agent, a coupling agent, etc. to impart adhesiveness.

[0242] When the wavelength selective absorption filter of the present invention also serves as the adhesive layer, the adhesive layer preferably contains 90 to 99.94% by mass of the above resin, more preferably 95 to 99.7% by mass. The content of the pigment is as described above.

[0243] The thickness of the adhesive layer is not particularly limited, but for example, it is preferably 1 to 50 μm, more preferably 3 to 30 μm.

[0244] <Liquid crystal cell>

[0245] The liquid crystal cell is not particularly limited, and a general liquid crystal cell can be used.

[0246] [OLED display device]

[0247] The organic electroluminescence display device of the present invention (referred to as an organic EL (electroluminescence) display device or an OLED (Organic Light Emitting Diode) display device, and also simply referred to as an OLED display device in the present invention.) includes the wavelength selective absorption filter of the present invention.

[0248] As the OLED display device of the present invention, as long as it includes the wavelength selective absorption filter of the present invention, as other structures, the structures of commonly used OLED display devices can be used without particular limitation. As an example of the structure of the OLED display device of the present invention, there is no particular limitation, but for example, a display device including glass, a layer containing a TFT (thin film transistor), an OLED display element, a barrier film, a color filter, glass, an adhesive layer, the wavelength selective absorption filter of the present invention, and a surface film in this order from the opposite side with respect to external light can be cited.

[0249] The above OLED display element has a structure in which an anode electrode, a light emitting layer, and a cathode electrode are laminated in this order. Between the anode electrode and the cathode electrode, in addition to the light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer, etc. are also included. In addition, for example, the description in Japanese Patent Application Laid-Open No. 2014-132522 can also be referred to.

[0250] And, as the above color filter, in addition to a normal color filter, a color filter in which quantum dots are laminated can also be used.

[0251] A resin film can also be used instead of the above glass.

[0252] In the present invention, the wavelength selective absorption filter of the present invention can be directly included, and thus the following structure can be adopted: the glass and the adhesive material layer provided on the outer light side of the above-described color filter are omitted, and from the opposite side with respect to the outer light, a glass, a layer including a TFT (thin film transistor), an OLED display element, a barrier film, a color filter, the wavelength selective absorption filter (substrate film, wavelength selective absorption filter layer) of the present invention, and a surface film are included in this order. Also, the following structure can be adopted: the above surface film is omitted, and from the opposite side with respect to the outer light, a glass, a layer including a TFT (thin film transistor), an OLED display element, a barrier film, a color filter, a glass, an adhesive layer, and the wavelength selective absorption filter (wavelength selective absorption filter layer, substrate film) of the present invention are included in this order.

[0253] <Adhesive layer>

[0254] In the OLED display device of the present invention, the surface on the outer light side of the wavelength selective absorption filter of the present invention can be adhered to a light functional film having an antireflection layer or the like via an adhesive layer. And, the surface of the wavelength selective absorption filter of the present invention on the side opposite to the outer light is preferably adhered to a glass (substrate) via an adhesive layer.

[0255] As the above adhesive layer, the descriptions related to the adhesive layer and the formation method in an OLED display device described in

[0239] to

[0290] of International Publication No. 2021 / 132674 can be directly applied.

[0256] In addition, from the viewpoint of the light resistance of the wavelength selective absorption filter, the adhesive composition described in International Publication No. 2021 / 132674 preferably contains an ultraviolet absorber.

[0257] <Substrate>

[0258] In the OLED display device of the present invention, the wavelength selective absorption filter of the present invention can also be adhered to a light functional film via an adhesive layer on the surface on the outer light side. And, the wavelength selective absorption filter of the present invention is preferably adhered to a glass (substrate) via an adhesive layer on the surface on the side opposite to the outer light.

[0259] The method for forming the above adhesive layer is not particularly limited. For example, the following methods can be used: a method of coating an adhesive composition on the wavelength selective absorption filter of the present invention using a general device such as a bar coater and drying and curing it; and a method of first coating the adhesive composition on the surface of a peelable substrate, drying it, and then transferring the adhesive layer to the wavelength selective absorption filter of the present invention using the peelable substrate and aging and curing it.

[0260] As the peelable substrate, there is no particular limitation, and any peelable substrate can be used. For example, the substrate film in the manufacturing method of the wavelength selective absorption filter of the present invention described above can be cited.

[0261] In addition, regarding the conditions for coating, drying, curing, and solidifying, they can also be appropriately adjusted according to conventional methods.

[0262] Examples

[0263] Hereinafter, examples will be given to further specifically illustrate the present invention. Regarding the materials, amounts used, ratios, treatment contents, treatment sequences, etc. shown in the following examples, they can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention is not limited to the examples shown below.

[0264] [Manufacture of Wavelength Selective Absorption Filter]

[0265] The materials for the wavelength selective absorption filter are shown below.

[0266] <Matrix Resin>

[0267] (Resin 1):

[0268] A random copolymer of cyclohexyl methacrylate and methacrylic acid, the content of the methacrylic acid structural unit in all the structural units of the polymer is 29 mol%, and the weight average molecular weight is 26,300.

[0269] (Resin 2):

[0270] Commercially available polystyrene resin (manufactured by PS Japan Corporation, product name: SGP - 10, glass transition temperature (Tg) 100 °C).

[0271] (Resin 3):

[0272] Commercially available styrene - acrylic acid copolymer (manufactured by TOAGOSEI CO., LTD., product name: ARU FON UC - 3920, the content of the acrylic acid structural unit in all the structural units of the polymer is 40 mol%)

[0273] <Dye>

[0274] A dye compound A (Dye A) having the following structure was used.

[0275] [Chemical Formula 11]

[0276]

[0277] <Leveling Agent 1>

[0278] Use a polymeric surfactant composed of the following components as a leveling agent 1. In the following structural formula, the ratio of each component is a molar ratio, and t-Bu refers to tert-butyl.

[0279] [Chemical formula 12]

[0280]

[0281] <Base film>

[0282] (Base film 1)

[0283] Use a commercially available polyethylene terephthalate film XD-510P (product name, film thickness 50 μm, manufactured by TO RAY INDUSTRIES, INC.) as base film 1.

[0284] <Fabrication of wavelength-selective absorption filter No. 101>

[0285] (Preparation of resin solution)

[0286] Mix each component according to the following composition to prepare a wavelength-selective absorption filter layer forming liquid (composition) Ba-1.

[0287]

[0288]

[0289] Next, filter the obtained wavelength-selective absorption filter layer forming liquid Ba-1 using a filter paper with an absolute filtration accuracy of 10 μm (#63, manufactured by TOYO ROSHI KAISHA, Ltd.), and further filter it through a metal sintered filter with an absolute filtration accuracy of 2.5 μm (FH025, manufactured by NIHON PALL LTD.).

[0290] (Fabrication of wavelength-selective absorption filter)

[0291] Using a bar coater, coat the above-mentioned filtered wavelength-selective absorption filter layer forming liquid Ba-1 on base film 1 so that the dried film thickness becomes 1.5 μm, and dry it at 100 °C to form a wavelength-selective absorption filter layer, thereby fabricating the wavelength-selective absorption filter No. 101 of the present invention.

[0292] <Fabrication of wavelength-selective absorption filter No. 102 and c201>

[0293] The matrix resin type was changed as shown in the following table. Other than that, in the same manner as the production of the wavelength selective absorption filter No. 101, the wavelength selective absorption filter No. 102 of the present invention and the wavelength selective absorption filter No. c201 of the comparative example were obtained.

[0294] [Evaluation of Wavelength Selective Absorption Filter]

[0295] The absorption maximum wavelength of the wavelength selective absorption filters of the present invention and the comparative example was measured by the following method, and the adhesion was evaluated by measuring the peel strength. The results are summarized in the following table.

[0296] -Measurement of the Absorption Maximum Wavelength of the Wavelength Selective Absorption Filter-

[0297] Using a UV3150 spectrophotometer (trade name) manufactured by SHIMADZU CORPORATION, the absorbance of the wavelength selective absorption filter in the wavelength range of 400 nm to 800 nm was measured at every 1 nm. The absorbance difference between the absorbance of the wavelength selective absorption filter at each wavelength and the absorbance of the wavelength selective absorption filter without pigment (wavelength selective absorption filter with the same matrix resin) was calculated, and the maximum value of this absorbance difference was set as the absorption maximum value, and the wavelength indicating this absorption maximum value was set as the absorption maximum wavelength (λ max ).

[0298] (Adhesion)

[0299] According to JIS (Japanese Industrial Standards) Z-0237 (2022), a 90-degree peel test was conducted in the following manner.

[0300] Specifically, the wavelength selective absorption filter was cut into a size of 25 mm in width and 150 mm in length, and the wavelength selective absorption filter layer side of the wavelength selective absorption filter was adhered to a glass substrate via an adhesive sheet (manufactured by Soken Chemical & Engineering Co., Ltd., trade name: STT-125CK). At the interface between the substrate film and the wavelength selective absorption filter layer, an opportunity for peeling was applied (by cutting with a cutter). Using a Tensilon universal material testing machine RTF-1210 (manufactured by A&D Company, Limited), the substrate film was fixed to one chuck, and the glass substrate was held by the other chuck. Under the conditions of a measurement temperature of 25 °C, a relative humidity of 60%, a load cell of 50 N, and a peel speed of 300 mm / min, the peel strength between the wavelength selective absorption filter layer and the substrate film when peeling the substrate film in the 90° direction, that is, the average value of the peel strength from the position of peeling 20 mm to the position of peeling 50 mm (average peel strength) was measured. Based on this peel strength, the adhesion was evaluated according to the following evaluation criteria.

[0301] -Evaluation Criteria-

[0302] ○: Peeling was performed with a peeling force of 5 N / 25 mm or more, or peeling was not possible under the above peeling conditions (no peeling between the wavelength-selective absorption filter layer and the substrate film, partial peeling of the adhesive used for bonding the wavelength-selective absorption filter layer to the glass substrate, or breakage of the wavelength-selective absorption filter itself).

[0303] △: Peeling was performed with a peeling force of 1 N / 25 mm or more and less than 5 N / 25 mm.

[0304] ×: Peeling was performed with a peeling force of less than 1 N / 25 mm.

[0305] [Table 1]

[0306]

[0307] (Remarks of the Table)

[0308] λ max : Represents the absorption maximum wavelength, with the unit of nm.

[0309] Mixing amount: Represents the mixing amount of the pigment relative to 100 parts by mass of the base resin, with the unit of parts by mass.

[0310] Thickness: The unit is μm.

[0311] In addition, the evaluation "〇" of the adhesion of the wavelength-selective absorption filter No. 101 indicates that peeling is not possible under the above peeling conditions.

[0312] As shown in Table 1, in the wavelength-selective absorption filter No. 101 using the resin 1 containing a carboxyl group, no peeling occurred. In the wavelength-selective absorption filter No. 102 using the resin 3 containing a carboxyl group, peeling occurred with a peeling force of 1 N / 25 mm or more and less than 5 N / 25 mm. In contrast, in the wavelength-selective absorption filter No. c201 using the resin 2 not containing a carboxyl group, peeling was performed with a weak peeling force of less than 1 N / 25 mm. It can be seen that by using a resin composed of a polymer containing a carboxyl group as the base resin, the adhesion between the wavelength-selective absorption filter layer and the substrate film (support) can be improved.

[0313] The present invention has been described together with its embodiments. However, unless otherwise specified, we do not intend to limit our invention to any details of the description, and it should be broadly interpreted without departing from the spirit and scope of the invention shown in the appended claims.

[0314] This application claims priority based on Japanese Patent Application No. 2022-185624 filed in Japan on November 21, 2022. By reference to them, their contents are incorporated herein by reference as part of the description of this specification.

Claims

1. A wavelength-selective absorption filter having a substrate film and a wavelength-selective absorption filter layer disposed in contact with the substrate film. The wavelength-selective absorption filter layer includes: a resin containing a carboxyl group; and a pigment having a main absorption wavelength band at a wavelength of 460 to 520 nm in an amount of 0.1 part by mass or more based on 100 parts by mass of the resin.

2. The wavelength-selective absorption filter according to claim 1, wherein The pigment is a squaric acid-based pigment represented by the following general formula (1). In the general formula (1), A and B each independently represent an aryl group which may have a substituent, a heterocyclic group which may have a substituent, or -CH=G, and G represents a heterocyclic group which may have a substituent.

3. The wavelength-selective absorption filter according to claim 1, wherein The peeling force between the wavelength-selective absorption filter layer and the base material film is 1 N / 25 mm or more.

4. A liquid crystal display device including the wavelength-selective absorption filter according to any one of claims 1 to 3.

5. An organic electroluminescent display device including the wavelength-selective absorption filter according to any one of claims 1 to 3.

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