CN110799865A - Optical film - Google Patents

Abstract

The invention provides an optical film, wherein a compound which is contained in a light selective absorption layer and selectively absorbs visible light with a short wavelength of about 400nm is not transferred to a layer except the light selective absorption layer, thereby inhibiting the deterioration of a phase difference film and providing good display characteristics. An optical film comprising at least 1 light selective absorbing layer formed of an active energy ray-curable composition, and satisfying the following formula (1): a (405) is not less than 0.5 (1). [ in the formula (1), A (405) represents the absorbance at a wavelength of 405nm ].

Description

Optical film

Technical Field

The present invention relates to optical films comprising at least 1 light selective absorbing layer.

Background

Display devices (FPD: flat panel display) such as organic EL display devices and liquid crystal display devices use various members such as display elements such as organic EL elements and liquid crystal cells, and optical films such as polarizing plates. Since organic EL compounds, liquid crystal compounds, and the like used in these members are organic substances, deterioration by Ultraviolet (UV) rays is likely to be a problem. In order to solve such a problem, for example, patent document 1 describes a polarizing plate in which an ultraviolet absorber having excellent ultraviolet absorbability in a wavelength region of 370nm or less is added to a protective film of the polarizing plate.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2006-308936

Disclosure of Invention

Problems to be solved by the invention

In recent years, development of a liquid crystal retardation film obtained by aligning a polymerizable liquid crystal compound and photocuring the aligned liquid crystal compound has been advanced in the progress of thinning of a display device. It has been clarified that: these liquid crystal retardation films and organic EL light emitting devices tend to be deteriorated not only by ultraviolet light but also by visible light having a short wavelength. However, the polarizing plate described in patent document 1 has excellent ultraviolet absorption ability in a wavelength region of 370nm or less, but may have low absorption performance for visible light having a short wavelength of 400nm or less, and thus deterioration of the liquid crystal retardation film or the organic EL light emitting element cannot be sufficiently suppressed.

Therefore, it has been investigated whether or not deterioration of a liquid crystal retardation film or an organic EL light-emitting element can be suppressed by disposing a pressure-sensitive adhesive layer having an absorption property of short-wavelength visible light of about 400 nm. The results of the study show that: when the compound having the absorption property of short-wavelength visible light of around 400nm is contained in the pressure-sensitive adhesive layer, the compound having the absorption property of short-wavelength visible light of around 400nm contained in the pressure-sensitive adhesive layer tends to migrate to another layer, and thus deterioration of the retardation film or the polarizing plate tends to occur.

Means for solving the problems

The present invention includes the inventions described below.

[1] An optical film comprising at least 1 light selective absorbing layer formed of an active energy ray-curable composition for providing an optical film, and satisfying the following formula (1).

A(405)≥0.5 (1)

[ in the formula (1), A (405) represents the absorbance at a wavelength of 405 nm. ]

[2] The optical film according to [1], which further satisfies the following formula (2).

A(440)≤0.1 (2)

[ in the formula (2), A (440) represents the absorbance at a wavelength of 440 nm. ]

[3] The optical film according to [1] or [2], which satisfies the following formula (3).

A(405)/A(440)≥5 (3)

In the formula (3), A (405) represents the absorbance at a wavelength of 405nm, and A (440) represents the absorbance at a wavelength of 440 nm. ]

[4] The optical film according to any one of [1] to [3], wherein the storage modulus E of the light selective absorption layer at 23 ℃ is 100MPa or more.

[5] The layer according to any one of [1] to [4], wherein the light selective absorption layer is a layer formed of an active energy ray-curable composition containing a photocurable component (A), a light selective absorption compound (B) and a photopolymerization initiator (C).

[6] The optical film according to [5], wherein the content of the light selective absorbing compound (B) is 0.01 to 20 parts by mass per 100 parts by mass of the photocurable component (A).

[7] The optical film according to [5] or [6], wherein the light selective absorbing compound (B) is a compound satisfying the following formula (4).

ε(405)≥20 (4)

[ in formula (4),. epsilon. (405) represents the gram absorption coefficient of the compound at a wavelength of 405 nm. The unit of the gram absorption coefficient is L/(g.cm). Angle (c)

[8] The optical film according to [7], wherein the light selective absorbing compound (B) is a compound satisfying formula (5).

ε(405)/ε(440)≥20 (5)

[ in the formula (5),. epsilon. (405) represents the gram absorption coefficient of the compound at a wavelength of 405nm, and. epsilon. (440) represents the gram absorption coefficient at a wavelength of 440 nm. ]

[9] The optical film according to any one of [6] to [8], wherein the photocurable component (A) contains at least 1 selected from a (meth) acryloyloxy group-containing compound and an epoxy compound.

[10] An optical film with an adhesive layer, comprising the optical film according to any one of [1] to [9] and an adhesive layer on at least one surface of the optical film.

[11] A display device having the optical film with an adhesive layer of [10 ].

ADVANTAGEOUS EFFECTS OF INVENTION

The compound selectively absorbing visible light having a short wavelength of about 400nm contained in the light selective absorption layer of the optical film of the present invention does not migrate to a layer other than the light selective absorption layer, and can suppress deterioration of the retardation film and provide excellent display characteristics.

Drawings

Fig. 1 is a schematic cross-sectional view showing an example of the optical film according to the present invention.

Fig. 2 is a schematic cross-sectional view showing an example of the layer structure of the optical laminate according to the present invention.

Fig. 3 is a schematic cross-sectional view showing an example of the layer structure of the optical laminate according to the present invention.

Fig. 4 is a schematic cross-sectional view showing an example of the layer structure of the optical laminate according to the present invention.

Fig. 5 is a schematic cross-sectional view showing an example of the layer structure of the optical laminate according to the present invention.

Fig. 6 is a schematic cross-sectional view showing an example of the layer structure of the optical laminate according to the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described herein, and various modifications can be made within the scope not impairing the gist of the present invention.

The optical film of the present invention comprises at least 1 light selective absorbing layer formed of an active energy ray-curable resin composition, and satisfies the following formula (1).

A(405)≥0.5 (1)

[ A (405) represents the absorbance of the optical film at a wavelength of 405 nm. ]

A (405) with a larger value indicates a larger absorption at a wavelength of 405 nm. If the value of a (405) is less than 1, absorption at a wavelength of 405nm is low, and the effect of suppressing deterioration of a display device such as a retardation film or an organic EL element under short-wavelength visible light is small. From the viewpoint of suppressing weather deterioration, the value of a (405) is preferably 0.6 or more, more preferably 0.8 or more, and particularly preferably 1.0 or more.

The optical film of the present invention preferably further satisfies the following formula (2).

A(440)≤0.1 (2)

[ in the formula (2), A (440) represents the absorbance at a wavelength of 440 nm. ]

A smaller value of A (440) indicates a lower absorption at a wavelength of 440 nm. If the value of a (440) exceeds 0.1, good color expression of the display device tends to be impaired. In addition, since light emission of the display device tends to be impaired, luminance of the display device may also be reduced. From the viewpoint of suppressing the inhibition of light emission of the display device, the value of a (440) is preferably 0.05 or less, more preferably 0.04 or less, and particularly preferably 0.03 or less.

The optical film of the present invention preferably further satisfies formula (3).

The optical film according to claim 1 or 2, which satisfies the following formula (3).

A(405)/A(440)≥5 (3)

In the formula (3), A (405) represents the absorbance at a wavelength of 405nm, and A (440) represents the absorbance at a wavelength of 440 nm. ]

The value of A (405)/A (440) represents the magnitude of absorption at a wavelength of 405nm relative to the magnitude of absorption at a wavelength of 440 nm. The larger the value of A (405)/A (440), the more specific the absorption in the wavelength region around 405 nm. The value of A (405)/A (440) is preferably 10 or more, more preferably 30 or more, and particularly preferably 60 or more.

< optical layered body of the present invention >

Fig. 1 is a schematic cross-sectional view of an example of the layer structure of the optical laminate of the present invention.

The optical film 10 of the present invention shown in fig. 1 has a light selective absorption layer 1 formed on at least one surface of a resin film 2 (for example, a resin film (a) described later). The light selective absorbing layer 1 may be a single layer or a plurality of layers. Further, an adhesive layer or an adhesive layer may be provided between the resin film 2 and the light selective absorbing layer 1. The adhesive layer in this case may be any adhesive layer formed of a known adhesive (water-based adhesive or active energy ray-curable adhesive), and the adhesive layer may be any adhesive layer formed of a known adhesive.

The optical laminate 10A shown in fig. 2 is an optical laminate including the optical film 10 of the present invention and a polarizing plate film. The light selective absorption layer 1 shown in fig. 2 also functions as an adhesive layer.

The optical laminate 10B shown in fig. 3 is an optical laminate including a resin film 2, a light selective absorption layer 1, a polarizing film 3, an adhesive layer 4, and a protective film 5. The adhesive layer 4 may be formed of a known adhesive, or the light selective absorbing layer 2 of the present application may be used as the adhesive layer. The protective film 5 may be a film having a phase difference (phase difference film).

The optical laminate 10C shown in fig. 4 and the optical laminate 10D shown in fig. 5 are optical laminates including a resin film 2, a light selective absorbing layer 1, a polarizing film 3, an adhesive layer 4, a protective film 5, an adhesive layer 6, an optical film 40, an adhesive layer 30, and a light emitting element 110. The adhesive layer 4 may be formed of a known adhesive, or the light selective absorbing layer 2 of the present application may be used as the adhesive layer.

The optical laminate 10E shown in fig. 6 is an optical laminate including the light selective absorption layer 1, the resin film 2, the adhesive layer 4, the polarizing film 3, the adhesive layer 4, and the resin film 2. In fig. 6, the light selective absorption layer 1 also functions as a surface treatment layer.

That is, the light selective absorbing layer 1 of the present invention also functions as an adhesive layer and also functions as a surface-treated layer.

The thickness of the light selective absorption layer 1 of the present invention is usually 0.1 to 30 μm.

The thickness of the light selective absorption layer 1 used as the surface treatment layer is preferably 5 to 15 μm. If it is less than 5 μm, the hardness may be insufficient. If the thickness exceeds 15 μm, residual solvent may remain or the adhesion of the coating film may be reduced.

The thickness when the light selective absorption layer 1 is used as an adhesive layer is usually 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less.

The storage modulus (E') of the light selective absorbing layer at 23 ℃ is preferably 100MPa or more, more preferably 500MPa or more, further preferably 1000MPa or more, and preferably 100000MPa or less. The storage modulus of the light selective absorbing layer at 80 ℃ is preferably 600MPa or more, more preferably 1000MPa or more, further preferably 1500MPa or more, and preferably 10000MPa or less.

In the case where the light selective absorbing layer 1 functions as a surface treatment film, the hardness of the light selective absorbing layer is preferably H or more, more preferably 3H or more, and still more preferably 4H or more in a pencil hardness test (load 4.9N) according to JIS K5600-5-4 (1999).

< light selective absorption layer >

The optical film of the present invention comprises at least 1 light selective absorbing layer formed of an active energy ray-curable composition. By including the light selective absorption layer, the optical film of the present invention satisfies formula (1). The light selective absorbing layer preferably satisfies the above formula (1), more preferably satisfies the above formulae (1) and (2), and still more preferably satisfies the above formulae (1), (2), and (3).

A light selective absorbing layer is formed on at least one surface of a resin film (hereinafter, sometimes referred to as resin film (a)).

The active energy ray-curable composition is a composition which is cured by irradiation with an active energy ray. The active energy ray includes ultraviolet rays, electron rays, X-rays, visible light, and the like, and preferably ultraviolet rays. The ultraviolet light source is preferably a light source having an emission distribution at a wavelength of 400nm or less, and examples thereof include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, and a metal halide lamp.

The active energy ray-curable composition contains a photocurable component (A), a light selective absorbing compound (B), and a photopolymerization initiator (C).

Examples of the photocurable component (a) include a compound or oligomer (radical polymerizable compound) which is cured by a radical polymerization reaction under irradiation of an active energy ray, and/or a compound (cation polymerizable compound) which is cured by a cation polymerization reaction under irradiation of an active energy ray.

< radically polymerizable Compound >

Examples of the radical polymerizable compound include radical polymerizable (meth) acrylic compounds. In the present specification, "(meth) acrylic compound" means a compound having 1 or more (meth) acryloyl groups in the molecule. "(meth) acryloyl" means at least one selected from acryloyl and methacryloyl. The same applies to "(meth) acryloyloxy", "(meth) acrylic", "meth) acrylate", and the like. The active energy ray-curable adhesive composition may contain 1 or 2 or more kinds of radical-polymerizable (meth) acrylic compounds.

Examples of the (meth) acrylic compound include (meth) acryloyl group-containing compounds such as (meth) acrylate monomers having at least 1 (meth) acryloyloxy group in the molecule, (meth) acrylamide monomers, and (meth) acrylic oligomers having at least 2 (meth) acryloyl groups in the molecule. The (meth) acrylic oligomer is preferably a (meth) acrylate oligomer having at least 2 (meth) acryloyloxy groups in the molecule. The (meth) acrylic compound may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the (meth) acrylate monomer include a monofunctional (meth) acrylate monomer having 1 (meth) acryloyloxy group in the molecule, a 2-functional (meth) acrylate monomer having 2 (meth) acryloyloxy groups in the molecule, and a polyfunctional (meth) acrylate monomer having 3 or more (meth) acryloyloxy groups in the molecule.

As the monofunctional (meth) acrylate monomer, an alkyl (meth) acrylate is cited. In the alkyl (meth) acrylate, if the alkyl group has 3 or more carbon atoms, the alkyl group may be linear, branched, or cyclic. Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Further, as the monofunctional (meth) acrylate monomer, there can be also mentioned: aralkyl (meth) acrylates such as benzyl (meth) acrylate; (meth) acrylic acid esters of terpene alcohols such as isobornyl (meth) acrylate; (meth) acrylates having a tetrahydrofurfuryl structure such as tetrahydrofurfuryl (meth) acrylate; (meth) acrylates having a cycloalkyl group at the alkyl moiety, such as cyclohexyl (meth) acrylate, cyclohexylmethyl methacrylate, dicyclopentyl acrylate, dicyclopentenyl (meth) acrylate, and 1, 4-cyclohexanedimethanol monoacrylate; aminoalkyl (meth) acrylates such as N, N-dimethylaminoethyl (meth) acrylate; and (meth) acrylates having an ether bond at the alkyl moiety, such as 2-phenoxyethyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, ethylcarbitol (meth) acrylate, and phenoxypolyethylene glycol (meth) acrylate.

Further, as the functional (meth) acrylate monomer, monofunctional (meth) acrylates having a hydroxyl group at the alkyl portion; a monofunctional (meth) acrylate having a carboxyl group at an alkyl site. Examples of the monofunctional (meth) acrylate having a hydroxyl group at an alkyl portion include 2-hydroxyethyl (meth) acrylate, 2-or 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, trimethylolpropane mono (meth) acrylate, and pentaerythritol mono (meth) acrylate. Examples of the monofunctional (meth) acrylate having a carboxyl group at an alkyl moiety include 2-carboxyethyl (meth) acrylate, ω -carboxypolycaprolactone (N ═ 2) mono (meth) acrylate, 1- [2- (meth) acryloyloxyethyl ] phthalic acid, 1- [2- (meth) acryloyloxyethyl ] hexahydrophthalic acid, 1- [2- (meth) acryloyloxyethyl ] succinic acid, 4- [2- (meth) acryloyloxyethyl ] trimellitic acid, and N- (meth) acryloyloxy-N ', N' -dicarboxymethylp-phenylenediamine.

The (meth) acrylamide monomer is preferably a (meth) acrylamide having a substituent at the N-position. Typical examples of the substituent at the N-position are alkyl groups, which may form a ring together with the nitrogen atom of (meth) acrylamide, and the ring may have an oxygen atom as a ring-forming atom in addition to a carbon atom and the nitrogen atom of (meth) acrylamide. Further, a substituent such as an alkyl group or an oxo group (═ O) may be bonded to a carbon atom constituting the ring.

Examples of the N-substituted (meth) acrylamide include: n-alkyl (meth) acrylamides such as N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-N-butyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, and N-hexyl (meth) acrylamide; n, N-dialkyl (meth) acrylamides such as N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) acrylamide, and the like. The N-substituent may be an alkyl group having a hydroxyl group, and examples thereof include N-hydroxymethyl (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- (2-hydroxypropyl) (meth) acrylamide and the like. Further, specific examples of the N-substituted (meth) acrylamide forming a 5-or 6-membered ring include N-acryloylpyrrolidine, 3-acryloyl-2-oxazolidinone, 4-acryloylmorpholine, N-acryloylpiperidine, and N-methacryloylpiperidine.

As the 2-functional (meth) acrylate monomer, there may be mentioned:

alkylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate, 1, 3-butylene glycol di (meth) acrylate, 1, 4-butylene glycol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 1, 9-nonanediol di (meth) acrylate, and neopentyl glycol di (meth) acrylate;

polyoxyalkylene glycol di (meth) acrylates such as diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and polytetramethylene glycol di (meth) acrylate;

di (meth) acrylates of halogen-substituted alkylene glycols such as tetrafluoroethylene di (meth) acrylate;

di (meth) acrylates of aliphatic polyhydric alcohols such as trimethylolpropane di (meth) acrylate, ditrimethylolpropane di (meth) acrylate, pentaerythritol di (meth) acrylate and the like;

hydrogenated dicyclopentadiene or tricyclodecanedialkanol di (meth) acrylates such as hydrogenated dicyclopentadienyl di (meth) acrylate and tricyclodecanedimethanol di (meth) acrylate;

1, 3-dioxane-2, 5-diylbis (meth) acrylate [ alternative name: dioxane diol or dioxane dialkanol di (meth) acrylate such as dioxane diol di (meth) acrylate;

di (meth) acrylates of alkylene oxide adducts of bisphenol a or bisphenol F such as bisphenol a ethylene oxide adduct diacrylate and bisphenol F ethylene oxide adduct diacrylate;

epoxy di (meth) acrylates of bisphenol a or bisphenol F such as acrylic acid adducts of bisphenol a diglycidyl ether and acrylic acid adducts of bisphenol F diglycidyl ether; silicone di (meth) acrylate;

di (meth) acrylate of neopentyl glycol hydroxypivalate;

2, 2-bis [4- (meth) acryloyloxyethoxyethoxyphenyl ] propane; 2, 2-bis [4- (meth) acryloyloxyethoxyethoxyethoxycyclohexyl ] propane;

di (meth) acrylate of 2- (2-hydroxy-1, 1-dimethylethyl) -5-ethyl-5-hydroxymethyl-1, 3-dioxane ];

tris (hydroxyethyl) isocyanurate di (meth) acrylate; and so on.

Examples of the 3-or more-functional polyfunctional (meth) acrylate monomer include 3-or more-functional poly (meth) acrylates of aliphatic polyhydric alcohols such as glycerol tri (meth) acrylate, alkoxylated glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, and dipentaerythritol hexa (meth) acrylate; poly (meth) acrylates of 3 or more functional halogen-substituted polyols; tri (meth) acrylates of alkylene oxide adducts of glycerol; tri (meth) acrylate of an alkylene oxide adduct of trimethylolpropane; 1, 1, 1-tris [ (meth) acryloyloxyethoxyethoxy ] propane; tris (hydroxyethyl) isocyanurate tri (meth) acrylate, and the like.

Examples of the (meth) acrylic oligomer include urethane (meth) acrylic oligomers, polyester (meth) acrylic oligomers, and epoxy (meth) acrylic oligomers.

The urethane (meth) acrylic oligomer refers to a compound having a urethane bond (-NHCOO-) and at least 2 (meth) acryloyl groups in a molecule. Specifically, the urethane-forming reaction product may be a urethane-forming reaction product of a hydroxyl group-containing (meth) acrylic monomer having at least 1 (meth) acryloyl group and at least 1 hydroxyl group in the molecule and a polyisocyanate, a urethane-forming reaction product of a terminal isocyanate group-containing urethane compound obtained by reacting a polyol and a polyisocyanate, and a (meth) acrylic monomer having at least 1 (meth) acryloyl group and at least 1 hydroxyl group in the molecule.

The hydroxyl group-containing (meth) acrylic monomer used in the above-mentioned urethanization reaction may be, for example, a hydroxyl group-containing (meth) acrylate monomer, and specific examples thereof include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycerol di (meth) acrylate, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate. Specific examples of the hydroxyl group-containing (meth) acrylate monomer other than the hydroxyl group-containing (meth) acrylate monomer include N-hydroxyalkyl (meth) acrylamide monomers such as N-hydroxyethyl (meth) acrylamide and N-hydroxymethyl (meth) acrylamide.

As the polyisocyanate to be subjected to the urethanization reaction with the hydroxyl group-containing (meth) acrylic monomer, there may be mentioned: diisocyanates or triisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, toluene diisocyanate, xylylene diisocyanate, diisocyanates obtained by hydrogenating aromatic isocyanates among these diisocyanates (e.g., hydrogenated toluene diisocyanate, hydrogenated xylylene diisocyanate, etc.), triphenylmethane triisocyanate, dibenzylbenzene triisocyanate, and polyisocyanates obtained by polymerizing the above diisocyanates.

As the polyol used in the application of the isocyanate group-containing urethane compound obtained by the reaction with the polyisocyanate, a polyester polyol, a polyether polyol or the like can be used in addition to the aromatic, aliphatic or alicyclic polyol. Examples of the aliphatic and alicyclic polyols include 1, 4-butanediol, 1, 6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, bis (trimethylolpropane), pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutyric acid, glycerol, hydrogenated bisphenol a, and the like.

The polyester polyol is obtained by dehydration condensation reaction of the above polyol with a polycarboxylic acid or an anhydride thereof. Examples of the polycarboxylic acid or the anhydride thereof include succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride), trimellitic acid (anhydride), pyromellitic acid (anhydride), phthalic acid (anhydride), isophthalic acid, terephthalic acid, hexahydrophthalic acid (anhydride), and the like, when the "anhydride" which may be an acid anhydride is used.

The polyether polyol may be a polyoxyalkylene-modified polyol obtained by reacting the above polyol or dihydroxybenzene with an alkylene oxide, in addition to the polyalkylene glycol.

The polyester (meth) acrylate oligomer means an oligomer having an ester bond and at least 2 (meth) acryloyloxy groups in the molecule.

The polyester (meth) acrylate oligomer can be obtained by, for example, subjecting (meth) acrylic acid, a polycarboxylic acid or an anhydride thereof, and a polyol to a dehydration condensation reaction.

Examples of the polycarboxylic acid or anhydride thereof include succinic anhydride, adipic acid, maleic anhydride, itaconic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, phthalic acid, succinic acid, maleic acid, itaconic acid, trimellitic acid, pyromellitic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, and terephthalic acid.

Examples of the polyhydric alcohol include 1, 4-butanediol, 1, 6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, bis (trimethylolpropane), pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutyric acid, glycerol, hydrogenated bisphenol a, and the like.

The epoxy (meth) acrylic oligomer can be obtained by addition reaction of a polyglycidyl ether with (meth) acrylic acid. The epoxy (meth) acrylic oligomer has at least 2 (meth) acryloyloxy groups in the molecule.

Examples of the polyglycidyl ether include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, and bisphenol a diglycidyl ether.

In the case of using the light selective absorbing layer as the surface treatment layer, the total content of the 2-functional (meth) acrylate monomer and the polyfunctional (meth) acrylate monomer is 50 parts by mass or more, preferably 60 parts by mass or more, and more preferably 80 parts by mass or more, relative to 100 parts by mass of the photocurable component (a), in order to increase the hardness of the light selective absorbing layer.

When a light selective absorbing layer is used as the adhesive layer, the content of the monofunctional (meth) acrylate monomer is 50 parts by mass or more, preferably 60 parts by mass or more, and more preferably 60 parts by mass or more per 100 parts by mass of the photocurable component (a) from the viewpoint of adhesion.

[ cationically polymerizable Compound ]

The cationically polymerizable compound is a compound or oligomer which is cured by a cationic polymerization reaction by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays or by heating. Examples of the cationically polymerizable compound include an epoxy compound, an oxetane compound, and a vinyl compound. The cationically polymerizable compound is preferably an epoxy compound. The epoxy compound is a compound having 1 or more (preferably 2 or more) epoxy groups in the molecule. The epoxy compound may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

Examples of the epoxy compound include alicyclic epoxy compounds, aromatic epoxy compounds, hydrogenated epoxy compounds, and aliphatic epoxy compounds. Among them, from the viewpoint of weather resistance, curing speed and adhesiveness, the epoxy compound is preferably an alicyclic epoxy compound or an aliphatic epoxy compound, and more preferably an alicyclic epoxy compound.

The alicyclic epoxy compound is a compound having 1 or more epoxy groups bonded to an alicyclic ring in a molecule. The "epoxy group bonded to an alicyclic ring" refers to a bridged oxygen atom-O-in the structure represented by the following formula (I). In the formula (I), m is an integer of 2-5.

[ solution 1]

(CH) of the above formula (I)₂)_mThe compound in which a group in a form from which 1 or more hydrogen atoms are removed is bonded to another chemical structure may be an alicyclic epoxy compound. (CH)₂)_m1 or more hydrogen atoms in (b) may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group.

Among them, a cured product of an alicyclic epoxy compound having an epoxycyclopentane structure (a structure in which m is 3 in the formula (I)) or an epoxycyclohexane structure (a structure in which m is 4 in the formula (I)) has a high glass transition temperature and is advantageous in terms of adhesion.

A: 3, 4-epoxycyclohexanecarboxylic acid 3, 4-epoxycyclohexylmethyl ester,

B: 3, 4-epoxy-6-methylcyclohexanecarboxylic acid 3, 4-epoxy-6-methylcyclohexylmethyl ester,

C: ethylene bis (3, 4-epoxycyclohexanecarboxylate),

D: bis (3, 4-epoxycyclohexylmethyl) adipate,

E: bis (3, 4-epoxy-6-methylcyclohexylmethyl) adipate,

F: diethylene glycol bis (3, 4-epoxycyclohexylmethyl ether),

G: ethylene glycol bis (3, 4-epoxycyclohexylmethyl ether),

H: 2, 3, 14, 15-diepoxy-7, 11, 18, 21-tetraoxatrispiro [5.2.2.5.2.2] heneicosane,

I: 3- (3, 4-epoxycyclohexyl) -8, 9-epoxy-1, 5-dioxaspiro [5.5] undecane,

J: 4-vinylcyclohexene dioxide,

K: a limonene dioxide,

L: bis (2, 3-epoxycyclopentyl) ether,

M: dicyclopentadiene dioxide.

[ solution 2]

[ solution 3]

The aromatic epoxy compound is a compound having an aromatic ring and an epoxy group in the molecule. Examples of the aromatic epoxy compound include: bisphenol-type epoxy compounds such as diglycidyl ether of bisphenol a, diglycidyl ether of bisphenol F, diglycidyl ether of bisphenol S, and oligomers thereof; phenol novolac type epoxy resins such as phenol novolac epoxy resin, cresol novolac epoxy resin, hydroxybenzaldehyde phenol novolac epoxy resin, and the like; polyfunctional epoxy compounds such as glycidyl ether of 2, 2 ', 4, 4' -tetrahydroxydiphenylmethane and glycidyl ether of 2, 2 ', 4, 4' -tetrahydroxybenzophenone; and polyfunctional epoxy resins such as epoxidized polyvinylphenols.

The hydrogenated epoxy compound is a glycidyl ether of a polyol having an alicyclic ring, and may be a compound obtained by glycidyl etherification of a nuclear hydrogenated polyhydroxy compound obtained by selectively hydrogenating an aromatic ring of an aromatic polyol in the presence of a catalyst under pressure. Specific examples of the aromatic polyol include, for example: bisphenol compounds such as bisphenol a, bisphenol F, and bisphenol S; phenol novolac resins such as phenol novolac resin, cresol novolac resin, hydroxybenzaldehyde phenol novolac resin, and the like; and polyfunctional compounds such as tetrahydroxydiphenylmethane, tetrahydroxybenzophenone, and polyvinyl phenol. Glycidyl ether can be produced by reacting epichlorohydrin with an alicyclic polyol obtained by hydrogenating an aromatic ring of an aromatic polyol. Among the hydrogenated epoxy compounds, preferred compounds include diglycidyl ethers of hydrogenated bisphenol a.

The aliphatic epoxy compound is a compound having at least 1 oxirane ring (3-membered cyclic ether) bonded to an aliphatic carbon atom in the molecule. Including for example: monofunctional epoxy compounds such as butyl glycidyl ether and 2-ethylhexyl glycidyl ether; 2-functional epoxy compounds such as 1, 4-butanediol diglycidyl ether, 1, 6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether; epoxy compounds having 3 or more functions such as trimethylolpropane triglycidyl ether and pentaerythritol tetraglycidyl ether; 4-vinylcyclohexene dioxide, limonene dioxide, and the like have 1 epoxy group directly bonded to an alicyclic ring and an oxirane ring bonded to an aliphatic carbon atom, and the like. Among these, from the viewpoint of adhesiveness, a 2-functional epoxy compound having 2 oxirane rings bonded to aliphatic carbon atoms in the molecule (also referred to as an aliphatic diepoxy compound) is preferable. The suitable aliphatic diepoxy compound can be represented by, for example, the following formula (II).

[ solution 4]

Y in the formula (II) is alkylene having 2-9 carbon atoms, alkylene having 4-9 carbon atoms in total and having ether bond in between, or C6-18 valent hydrocarbon group having alicyclic structure.

Examples of the aliphatic diepoxy compound represented by the above formula (II) include diglycidyl ethers of alkanediols, diglycidyl ethers of oligoalkylene glycols having a repetition number of about 4, diglycidyl ethers of alicyclic glycols, and the like.

The oxetane compound is a compound containing 1 or more oxetane rings (oxetanyl groups) in the molecule. Examples of the oxetane compound include 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyloxetane, 1, 4-bis { (3-ethyloxetan-3-yl) methoxy } methyl ] benzene, 3-ethyl-3 { (3-ethyloxetan-3-yl) methoxy } methyl ] oxetane, 3-ethyl-3- (phenoxymethyl) oxetane, and 3- (cyclohexyloxy) methyl-3-ethyloxetane. The oxetane compound may be used as a main component of the cationically polymerizable compound, or may be used in combination with an epoxy compound. The curing rate and adhesion may be improved by using an oxetane compound in combination.

The vinyl compound may be an aliphatic or alicyclic vinyl ether compound. Examples of the vinyl compound include: vinyl ethers of alkyl or alkenyl alcohols having 5 to 20 carbon atoms such as n-amyl vinyl ether, isoamyl vinyl ether, n-hexyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl vinyl ether, n-dodecyl vinyl ether, stearyl vinyl ether, oleyl vinyl ether and the like; hydroxyl-containing vinyl ethers such as 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether and 4-hydroxybutyl vinyl ether; vinyl ethers of monohydric alcohols having an aliphatic ring or an aromatic ring, such as cyclohexyl vinyl ether, 2-methylcyclohexyl vinyl ether, cyclohexyl methyl vinyl ether, and benzyl vinyl ether; monovinyl ethers to polyvinyl ethers of polyhydric alcohols such as glycerol monovinyl ether, 1, 4-butanediol divinyl ether, 1, 6-hexanediol divinyl ether, neopentyl glycol divinyl ether, pentaerythritol tetravinyl ether, trimethylolpropane divinyl ether, trimethylolpropane trivinyl ether, 1, 4-dihydroxycyclohexane monovinyl ether, 1, 4-dihydroxycyclohexane divinyl ether, 1, 4-dihydroxymethylcyclohexane monovinyl ether, 1, 4-dihydroxymethylcyclohexane divinyl ether, and the like; monovinyl ethers to divinyl ethers of polyalkylene glycols such as diethylene glycol divinyl ether, triethylene glycol divinyl ether, and diethylene glycol monobutyl monovinyl ether; glycidyl vinyl ether, ethylene glycol vinyl ether methacrylate, and the like.

The vinyl compound may be used as a main component of the cationically polymerizable compound, or may be used in combination with an epoxy compound, or an epoxy compound and an oxetane compound. The use of a vinyl compound may increase the curing rate and reduce the viscosity of the adhesive.

The photocurable component (a) may be a combination of a radical polymerizable compound and a cation polymerizable compound.

The content of the photocurable component (a) is usually 50 to 99.5% by mass, preferably 70 to 97% by mass, based on 100% by mass of the active energy ray-curable composition.

< light selective absorption Compound (B) >

The light selective absorbing compound (B) is preferably a compound that selectively absorbs light having a wavelength of 405nm and satisfies the formula (5), and more preferably a compound that also satisfies the formula (6).

ε(405)≥20 (5)

[ in formula (5),. epsilon. (. 405) represents the gram absorption coefficient of the compound at a wavelength of 405 nm. The unit of the gram absorption coefficient is L/(g.cm). Angle (c)

ε(405)/ε(440)≥20 (6)

[ in formula (6),. epsilon. (405) represents the gram absorption coefficient of the compound at a wavelength of 405nm, and. epsilon. (440) represents the gram absorption coefficient at a wavelength of 440 nm. ]

The gram absorbance coefficient was measured by the method described in examples.

The larger the value of ε (405), the more easily the compound absorbs light having a wavelength of 405nm, and the more easily the compound exhibits a function of suppressing deterioration due to ultraviolet light or short-wavelength visible light. If the value of ∈ (405) is less than 20L/(g · cm), the content of the light selective absorbing compound (B) in the light absorption selective layer increases in order to exhibit a function of suppressing deterioration of the retardation film or the organic EL light emitting element due to ultraviolet light or short-wavelength visible light. When the content of the light selective absorbing compound (B) is increased, the light selective absorbing compound (B) may bleed out or be unevenly dispersed, and the light absorbing function may be insufficient. The value of ε (405) is preferably 20L/(g cm) or more, more preferably 30L/(g cm) or more, still more preferably 40L/(g cm) or more, and usually 500L/(g cm) or less.

As the value of ε (405)/ε (440) increases, light near 405nm is absorbed without inhibiting the color expression of a display device, and thus the light degradation of a display device such as a retardation film or an organic EL element can be suppressed. The value of c (405)/ε (440) is preferably 20 or more, more preferably 40 or more, still more preferably 70 or more, and still more preferably 80 or more.

The light selective absorbing compound (B) is preferably a compound having a merocyanine structure in the molecule. The compound having a merocyanine structure is a compound having a partial structure represented by- (N-C) -in the molecule, and examples thereof include merocyanine compounds, cyanine compounds, indole compounds, and benzotriazole compounds.

The light selective absorbing compound (B) is preferably a compound represented by formula (I) (hereinafter, may be referred to as compound (I)).

[ in the formula, R¹And R⁵Each independently represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms which may have a substituent, an aralkyl group having 7 to 15 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms, a heterocyclic group, or-CH contained in the alkyl group or the aralkyl group₂-may be replaced by-NR^1A-、-CO-、-SO₂-, -O-or-S-.

R^1ARepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

R²、R³And R⁴Each independently represents a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, -CH contained in the alkyl group₂-may be replaced by-NR^1B-、-CO-、-NO₂-, -O-or-S-.

R^1BRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

R⁶And R⁷Each of which independently represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms or an electron-withdrawing group, or R⁶And R⁷May be joined to form a ring structure.

R¹And R²Can be connected to each other to form a ring structure, R²And R³Can be connected to each other to form a ring structure, R²And R⁴Can be connected to each other to form a ring structure, R³And R⁶May be joined to form a ring structure.]

As R¹And R⁵Examples of the alkyl group having 1 to 25 carbon atoms include methyl, ethyl, n-propyl, isopropyl, 2-cyanopropyl, n-butyl, tert-butyl, sec-butyl, n-pentyl, n-hexyl, 1-methylbutyl, 3-methylbutyl, n-octyl, n-decyl, and 2-hexyloctyl.

As R¹And R⁵Examples of the substituent that the alkyl group having 1 to 25 carbon atoms may have include groups described in the following group a.

Group A: examples thereof include nitro, hydroxy, carboxyl, sulfo, cyano, amino, halogen, alkoxy having 1 to 6 carbon atoms, alkylsilyl having 1 to 12 carbon atoms, alkylcarbonyl having 2 to 8 carbon atoms, and R^a1-(O-R^a2)_t1-R^a3(R^a1And R^a2Each independently represents an alkanediyl group having 1 to 6 carbon atoms, R^a3Represents an alkyl group having 1 to 6 carbon atoms, and s1 represents an integer of 1 to 3. ) The groups shown, and the like.

Examples of the alkylsilyl group having 1 to 12 carbon atoms include: monoalkylsilyl groups such as methylsilyl group, ethylsilyl group, and propylsilyl group; dialkylsilyl groups such as dimethylsilyl group, diethylsilyl group and methylethylsilyl group; trialkylsilyl groups such as trimethylsilyl, triethylsilyl and tripropylsilyl groups.

Examples of the alkylcarbonyl group having 2 to 8 carbon atoms include a methylcarbonyl group, an ethylcarbonyl group and the like.

Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

As R¹And R⁵Examples of the aralkyl group having 7 to 15 carbon atoms include benzyl group and phenylethyl group. as-CH contained in aralkyl groups₂-is replaced by-SO₂Examples of the group derived from-or-COO-include 2-phenylacetic acid ethyl ester group and the like.

As R¹And R⁵Examples of the substituent which the aralkyl group having 7 to 15 carbon atoms may have include those described in the above group A.

As R¹And R⁵Examples of the aryl group having 6 to 15 carbon atoms include a phenyl group, a naphthyl group, and an anthryl group.

As R¹And R⁵Examples of the substituent which the aryl group having 6 to 15 carbon atoms may have include those described in the above group A.

As R¹And R⁵Examples of the heterocyclic group having 6 to 15 carbon atoms include aromatic heterocyclic groups having 3 to 9 carbon atoms such as a pyridyl group, a pyrrolidinyl group, a quinolyl group, a thienyl group, an imidazolyl group, an oxazolyl group, a pyrrolyl group, a thiazolyl group and a furyl group.

As R^1AAnd R^1BExamples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, and an n-hexyl group.

As R²、R³And R⁴Examples of the alkyl group having 1 to 6 carbon atoms include the group represented by R^1BThe alkyl groups having 1 to 6 carbon atoms are the same.

As R²、R³And R⁴Examples of the substituent that the alkyl group having 1 to 6 carbon atoms may have include those described in the above group A.

As R²、R³And R⁴The aromatic hydrocarbon group shown includes: aryl groups having 6 to 15 carbon atoms such as phenyl, naphthyl and anthracenyl; aralkyl groups having 7 to 15 carbon atoms such as benzyl group and phenylethyl group.

As R²、R³And R⁴The aromatic hydrocarbon group may have a substituent, and examples thereof include those described in the above group a.

As R²、R³And R⁴Examples of the aromatic heterocyclic group include aromatic heterocyclic groups having 3 to 9 carbon atoms such as pyridyl, pyrrolidinyl, quinolyl, thienyl, imidazolyl, oxazolyl, pyrrolyl, thiazolyl and furyl groups.

As R²、R³And R⁴Examples of the substituent that the aromatic heterocyclic ring may have include those described in the above group A.

As R⁶And R⁷Examples of the alkyl group having 1 to 25 carbon atoms include the group represented by R¹And R⁵The alkyl groups having 1 to 25 carbon atoms are the same.

As R⁶And R⁷Examples of the substituent that the alkyl group having 1 to 25 carbon atoms may have include those described in the above group A.

As R⁶And R⁷Examples of the electron-withdrawing group include a cyano group, a nitro group, a halogen atom, an alkyl group substituted with a halogen atom, and a group represented by the formula (I-1).

*-X¹-R¹¹(I-1)

[ in the formula, R¹¹Represents a hydrogen atom or an alkyl group having 1 to 25 carbon atoms, and at least 1 methylene group contained in the alkyl group may be replaced with an oxygen atom.

X¹represents-CO-, -COO-, -OCO-, -NR¹²CO-or CONR¹³-。

R¹²And R¹³Are respectively provided withIndependently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group.]

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alkyl group substituted with a halogen atom include a perfluoroalkyl group such as a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. The number of carbon atoms of the alkyl group substituted with a halogen atom is usually 1 to 25.

As R¹¹Examples of the alkyl group having 1 to 25 carbon atoms include the group represented by R¹And R⁵Alkyl groups shown are the same groups.

As R¹²And R¹³Examples of the alkyl group having 1 to 6 carbon atoms include the group represented by R^1AThe alkyl groups having 1 to 6 carbon atoms are the same.

R⁶And R⁷Can be connected to each other to form a ring structure consisting of R⁶And R⁷Examples of the ring structure to be formed include a meldrum's acid structure, a barbituric acid structure, and a dimedone structure.

As R²And R³The ring structures formed by bonding to each other are those including R²Examples of the nitrogen-containing ring structure of the bonded nitrogen atom include a 4 to 14-membered nitrogen-containing heterocyclic ring. R²And R³The ring structure formed by the mutual connection may be a single ring or multiple rings. Specific examples thereof include a pyrrolidine ring, a pyrroline ring, an imidazolidine ring, an imidazoline ring, an oxazoline ring, a thiazoline ring, a piperidine ring, a morpholine ring, a piperazine ring, an indole ring, and an isoindole ring.

As R¹And R²The ring structures formed by bonding to each other are those including R¹And R²Examples of the nitrogen-containing ring structure of the bonded nitrogen atom include a nitrogen-containing heterocycle having 4 to 14 rings (preferably 4 to 8 rings). R¹And R²The ring structure formed by the mutual connection may be a single ring or multiple rings. Specifically, R is²And R³Ring structure phase formed by mutual connectionThe same ring structure.

As R²And R⁴Examples of the ring structure formed by bonding to each other include a nitrogen-containing ring structure having 4 to 14 rings, preferably a nitrogen-containing ring structure having 5 to 9 rings. R²And R⁴The ring structures formed by bonding to each other may be monocyclic or polycyclic. These rings may have a substituent, and examples of such a ring structure include the above-mentioned R²And R³The ring structures formed by connecting the ring structures to each other are exemplified by the same ring structures.

As R³And R⁶The ring structures formed by the mutual connection are R³-C＝C-C＝C-R⁶Forming the ring structure of the ring backbone. Examples thereof include phenyl group.

As R²And R³The compound represented by the formula (I) which is linked to each other to form a ring structure includes a compound represented by the formula (I-A) wherein R is²And R⁴The compound represented by the formula (I) which is linked to each other to form a ring structure includes compounds represented by the formula (I-B).

[ formula (I-A) or formula (I-B) wherein R¹、R³、R⁴、R⁵、R⁶And R⁷Each means the same as described above.

Ring W¹And a ring W²Each independently represents a nitrogen-containing ring.]

Ring W¹And a ring W²Represents a nitrogen-containing ring containing a nitrogen atom as a ring constituent unit. Ring W¹And a ring W²Each of which may be independently monocyclic or polycyclic, and may contain a hetero atom other than nitrogen as a constituent unit of the ring. Ring W¹And a ring W²Rings each independently having 5 to 9 members are preferred.

The compound represented by the formula (I-A) is preferably a compound represented by the formula (I-A-1).

[ in the formula (I-A), R¹、R⁴、R⁵、R⁶And R⁷Each means the same as described above.

A¹represents-CH₂-, -O-, -S-or-NR^1D-。

R¹⁴And R¹⁵Each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

R^1DRepresents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.]

The compound represented by the formula (I-B) is preferably a compound represented by the formula (I-B-1) or a compound represented by the formula (I-B-2).

[ in the formula (I-B-1), R¹、R⁶And R⁷Each means the same as described above.

R¹⁶Each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group.]

[ in the formula (I-B-2), R³、R⁵、R⁶And R⁷Each means the same as described above.

R³⁰Represents a hydrogen atom, a cyano group, a nitro group, a halogen atom, a mercapto group, an amino group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an acyl group having 2 to 13 carbon atoms, an acyloxy group having 2 to 13 carbon atoms, or an alkoxycarbonyl group having 2 to 13 carbon atoms.

R³¹Represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a mercapto group, an alkylthio group having 1 to 12 carbon atoms, an amino group which may have a substituent or a heterocyclic group.]

As R³⁰Shown inExamples of the halogen atom of (2) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

As R³⁰R is shown³⁰Examples of the acyl group having 2 to 13 carbon atoms include acetyl, propionyl, and butyryl.

As R³⁰Examples of the acyloxy group having 2 to 13 carbon atoms include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, and a butylcarbonyloxy group.

As R³⁰Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group and the like.

As R³⁰The aromatic hydrocarbon group having 6 to 18 carbon atoms includes: aryl groups having 6 to 18 carbon atoms such as phenyl, naphthyl and biphenyl; aralkyl groups having 7 to 18 carbon atoms such as benzyl group and phenylethyl group.

As R³⁰Examples of the alkyl group having 1 to 12 carbon atoms include the group represented by R¹⁴The alkyl groups having 1 to 12 carbon atoms are the same.

As R³⁰Examples of the alkyl group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group.

R³⁰Preferably an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an amino group or a mercapto group.

As R³¹Examples of the alkyl group having 1 to 12 carbon atoms include the group represented by R¹⁴The alkyl groups having 1 to 12 carbon atoms are the same.

As R³¹The alkoxy group having 1 to 12 carbon atoms is exemplified by R³⁰The alkoxy groups having 1 to 12 carbon atoms are the same.

As R³¹Examples of the alkylthio group having 1 to 12 carbon atoms include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, and a hexylthio group.

As R³¹Examples of the amino group which may have a substituent include: an amino group; n-methylamino, N-ethylamino, etc. having 1 carbon atom number up to 18 alkyl-substituted amino; and amino groups substituted with an alkyl group having 2 carbon atoms of 1 to 8, such as an N, N-dimethylamino group, an N, N-diethylamino group, and an N, N-methylethylamino group.

As R³¹Examples of the heterocyclic group include nitrogen-containing heterocyclic groups having 4 to 9 carbon atoms such as a pyrrolidinyl group, a piperidinyl group, and a morpholinyl group.

As R³And R⁶Are connected to each other to form a ring structure, and R²And R⁴The compound represented by the formula (I) which forms a ring structure by bonding to each other includes compounds represented by the formula (I-C).

[ in the formula (I-C), R¹、R⁶And R⁷The same meanings as described above are indicated.

R²¹、R²²Each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a hydroxyl group.

X²And X³Each independently represents-CH₂-or-N (R)²⁵)＝。

R²⁵Represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, or an aromatic hydrocarbon group which may have a substituent.]

As R²⁵Examples of the alkyl group having 1 to 25 carbon atoms include the group represented by R¹The alkyl groups having 1 to 25 carbon atoms are the same.

As R²⁵The aromatic hydrocarbon group shown includes: aryl groups such as phenyl and naphthyl: aralkyl groups such as benzyl and phenylethyl: biphenyl, and the like, preferably an aromatic hydrocarbon group having 6 to 20 carbon atoms. As R²⁵Examples of the substituent which may be contained in the aromatic hydrocarbon group include a hydroxyl group.

R³And R⁶Each independently is preferably an electron-withdrawing group.

As R¹And R²Are connected to each other to form a ring structure, and R³And R⁶Formation of a ring structure by bonding to each otherExamples of the compound include compounds represented by the formula (I-D).

[ formula (I-D) wherein R⁴、R⁵、R⁷The same meanings as described above are indicated.

R²⁵、R²⁶、R²⁷And R²⁸Each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, a hydroxyl group, or an aralkyl group.]

As R²⁵、R²⁶、R²⁷And R²⁸Examples of the alkyl group having 1 to 12 carbon atoms include the group represented by R^1AAnd R^1BThe alkyl groups having 1 to 12 carbon atoms are the same. As R²⁵、R²⁶、R²⁷And R²⁸Examples of the substituent that the alkyl group having 1 to 12 carbon atoms may have include a hydroxyl group.

As R²⁵、R²⁶、R²⁷And R²⁸Examples of the aralkyl group include aralkyl groups having 7 to 15 carbon atoms such as a benzyl group and a phenylethyl group.

As R⁶And R⁷Examples of the compound (I) which is linked to each other to form a ring structure include compounds represented by the formula (I-E).

[ in the formula (I-C), R¹、R³、R⁴、R⁵Each means the same as described above.

Ring W³Represents a cyclic compound.]

Ring W³The ring having a 5-to 9-membered ring may contain a heteroatom such as a nitrogen atom, an oxygen atom or a sulfur atom as a constituent unit of the ring.

The compound represented by the formula (I-E) is preferably a compound represented by the formula (IE-1).

[ formula (I-E-1) wherein R¹、R²、R³And R⁵Each means the same as described above.

R¹⁷、R¹⁸、R¹⁹、R^qEach independently represents a hydrogen atom or an optionally substituted alkyl, aralkyl or aryl group having 1 to 12 carbon atoms, -CH contained in the alkyl or aralkyl group₂The-radical being replaceable by-NR^2D-、-C(＝O)-、-C(＝S)-、-O-、-S-，R¹⁷And R¹⁸Can be connected to each other to form a ring structure, R¹⁸And R¹⁹Can be connected to each other to form a ring structure, R¹⁹And Rq may be connected to each other to form a ring structure. R^2DRepresents a hydrogen atom or an optionally substituted alkyl, aralkyl or aryl group having 1 to 12 carbon atoms, -CH contained in the alkyl or aralkyl group₂The-group may be substituted with-C (═ O) -, -C (═ S) -, -O-, -S-.

m, p and q independently represent an integer of 1 to 3. ]

The compound represented by the formula (I) includes the following compounds.

The content of the light selective absorbing compound (B) is usually 0.01 to 20 parts by mass, preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, and still more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the photocurable component (a).

< photopolymerization initiator (C) >

[ radical polymerizable initiator ]

When the photocurable component (a) is a radical polymerization compound, the photopolymerization initiator (C) contains a photoradical polymerization initiator. In addition, a thermal radical polymerization initiator may be contained. The photo radical polymerization initiator is a polymerization initiator which initiates a polymerization reaction of a radical curable compound by irradiation with active energy rays such as visible rays, ultraviolet rays, X-rays, or electron rays. The active energy ray-curable adhesive composition may contain 1 or 2 or more kinds of radical polymerization initiators.

As the photo radical polymerization initiator and the thermal radical polymerization initiator, conventionally known polymerization initiators can be used. Examples of the photo radical polymerization initiator include acetophenone-based initiators such as acetophenone, 3-methylacetophenone, benzildimethylketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl-2-morpholinopropan-1-one, and 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzophenone-based initiators such as benzophenone, 4-chlorobenzophenone and 4, 4' -diaminobenzophenone; benzoin ether-based initiators such as benzoin propyl ether, benzoin methyl ether, and benzoin ethyl ether; thioxanthone initiators such as 4-isopropylthioxanthone; xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone, etc.

The content of the radical polymerization initiator is usually 0.5 to 20 parts by mass, preferably 1 to 6 parts by mass, per 100 parts by mass of the radical polymerizable compound. By containing 0.5 parts by weight or more of a radical polymerization initiator, the radical polymerizable compound can be sufficiently cured.

(cationic polymerization initiator)

When the photocurable component (a) is a cationically polymerizable compound, the photopolymerization initiator (C) is a photocationic polymerization initiator. The photo cation polymerization initiator is a polymerization initiator which generates a cation species or a lewis acid by irradiation of active energy rays such as visible rays, ultraviolet rays, X-rays, or electron rays, and initiates a polymerization reaction of a cation curable compound. The photo cation polymerization initiator functions as a catalyst under light, and therefore, even when mixed with a photo cation curable compound, is excellent in storage stability and handling properties. Examples of the compound that generates a cationic species or a lewis acid by irradiation with an active energy ray include: onium salts such as aromatic iodonium salts and aromatic sulfonium salts; an aromatic diazonium salt; iron-arene complexes, and the like.

The aromatic iodonium salt is a compound having a diaryliodonium cation, and typically, a diphenyliodonium cation is mentioned as the cation. The aromatic sulfonium salt is a compound having a triarylsulfonium cation, and typical examples of the cation include a triphenylsulfonium cation and a 4, 4' -bis (diphenylsulfonium) diphenylsulfide cation. The aromatic diazonium salt is a compound having a diazonium cation, and typically, the diazonium cation is a benzenediazonium cation. In addition, the iron-arene complex is typically a cyclopentadienyl iron (II) arene cation complex salt.

The cation shown above and the anion (anion) form a pair to constitute a photo cation polymerization initiator. Examples of the anion constituting the photo cation polymerization initiator include a specific phosphorus anion [ (Rf)_nPF_6-n]^-Hexafluorophosphate radical anion PF₆ ^-Hexafluoroantimonate anion SbF₆ ^-Pentafluoro-hydroxyl antimonate anion SbF₅(OH)^-Hexafluoroarsenate anion AsF₆ ^-Tetrafluoroborate anion BF₄ ^-Tetrakis (pentafluorophenyl) borate anion B (C)₆F₅)₄ ^-And the like. Among them, a specific phosphorus anion [ (Rf) is preferred from the viewpoint of curability of the cationically polymerizable compound and safety of the obtained photo-selective absorption layer_nPF_6-n]^-Hexafluorophosphate radical anion PF₆ ^-。

The photo cation polymerization initiator may be used alone in 1 kind, or may be used in combination in 2 or more kinds. Among them, the aromatic sulfonium salt is preferably used because it has ultraviolet absorption characteristics even in a wavelength region of about 300nm and can provide a cured product having excellent curability and good mechanical strength and adhesive strength.

The content of the photo cation polymerization initiator is usually 0.5 to 10 parts by mass, and preferably 6 parts by mass or less, per 100 parts by mass of the cation polymerizable compound. By adding 0.5 parts by mass or more of the photo cation polymerization initiator, the cation polymerizable compound can be sufficiently cured.

(optional Components)

The active energy ray-curable composition may contain additives as needed. Examples of the additives include an ion scavenger, a chain transfer agent, a polymerization accelerator, a sensitizer, a sensitizing aid, a light stabilizer, a thickener, a filler, a flow control agent, a plasticizer, a defoaming agent, a leveling agent, a silane coupling agent, light-transmitting fine particles, a solvent such as an organic solvent, a thermal polymerization initiator, a blocking agent, an antifouling agent, a surfactant, a crosslinking agent, a curing agent, a viscosity control agent, an antistatic agent, an antifouling agent, a slip agent, a refractive index control agent, and a dispersing agent.

When the active energy ray-curable composition is used for forming a surface treatment layer such as a hard coat layer, it preferably contains an organic solvent. As the organic solvent, there may be mentioned: aliphatic hydrocarbons such as hexane, cyclohexane, and octane; aromatic hydrocarbons such as toluene and xylene; alcohols such as methanol, ethanol, 1-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, benzyl alcohol, PGME, ethylene glycol, cyclohexanol, etc.; ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, heptanone, diisobutyl ketone, and diethyl ketone; esters such as ethyl acetate, butyl acetate, isobutyl acetate, etc.; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; esterified glycol ethers such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; cellosolves such as 2-methoxyethanol, 2-ethoxyethanol, and 2-butoxyethanol; carbitols such as 2- (2-methoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethanol, and 2- (2-butoxyethoxy) ethanol; aliphatic hydrocarbons such as hexane and cyclohexane; halogenated hydrocarbons such as dichloromethane, chloroform, carbon tetrachloride and the like; aromatic hydrocarbons such as benzene, toluene, and xylene; amides such as dimethylformamide, dimethylacetamide and n-methylpyrrolidone; ethers such as diethyl ether, dioxane, and tetrahydrofuran; ether alcohols such as 1-methoxy-2-propanol; water, and the like. The organic solvent may be selected and used in consideration of viscosity and the like. By including an organic solvent in the active energy ray-curable composition, the coatability of the resin film is improved.

These organic solvents may be used alone or in combination of two or more if necessary. When the active energy ray-curable composition contains an organic solvent, the organic solvent needs to be evaporated after coating. Therefore, it is desirable that the organic solvent has a boiling point in the range of 60 ℃ to 160 ℃. Further, it is preferable that the saturated vapor pressure at 20 ℃ is in the range of 0.1kPa to 20 kPa.

Examples of the leveling agent include known leveling agents such as a fluorine-based leveling agent, a silicone-based leveling agent, and an acrylic leveling agent. The content of the leveling agent is preferably 0.1 to 1 part by mass per 100 parts by mass of the photocurable component (a). If the amount is less than 0.1 part by mass, particularly in the case where the light selective absorbing layer is a surface-treated layer, the surface planarity is deteriorated, haze or unevenness is liable to occur, and there is a risk that the anti-blocking property cannot be sufficiently exhibited. On the other hand, if it exceeds 1 part by mass, the dispersibility or pot life of the active energy ray-curable composition tends to be poor.

The active energy ray-curable composition may have an adhesive function depending on the kind of the photocurable component (a) and the like, and may be used as an adhesive. When the active energy ray-curable composition is used as the adhesive, the viscosity is preferably low. Specifically, the viscosity at 25 ℃ is preferably 1000 mPas or less, more preferably 500 mPas or less, further preferably 300 mPas or less, and usually 250 mPas or more. The curable adhesive composition according to the present invention may be a solventless type, and may contain an organic solvent in order to adjust the viscosity suitable for the application method used.

< resin film (a) >

The resin film (a) may be a film having an optical function, such as a polarizing film, a retardation film, or a window film. The film having an optical function means a film capable of transmitting, reflecting, and absorbing light.

The window film is a front panel of a flexible display device such as a flexible display, and is generally disposed on the outermost surface of the display device. The window film may be, for example, a resin film made of a polyimide resin. The window film may be a film of a mixture of an organic material and an inorganic material, such as a resin film containing polyimide and silica. The window film may have a hard coat layer provided on the surface thereof for imparting functions of surface hardness, stain resistance, and fingerprint resistance. Examples of the window film include those described in Japanese patent application laid-open No. 2017-94488.

[ retardation film ]

The retardation film is an optical film exhibiting optical anisotropy, and examples thereof include a stretched film obtained by stretching a polymer film made of polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride/polymethyl methacrylate, acetyl cellulose, an ethylene-vinyl acetate copolymer saponified product, polyvinyl chloride, or the like by about 1.01 to 6 times. Among these, a polymer film obtained by uniaxially or biaxially stretching a polycarbonate film or a cycloolefin resin film is preferable. The retardation film may be one obtained by curing a polymerizable liquid crystal compound. In the present specification, the retardation film includes a zero retardation film, and also includes films such as a uniaxial retardation film, a low photoelastic modulus retardation film, and a wide viewing angle retardation film.

Examples of the film exhibiting optical anisotropy by application and alignment of a liquid crystal compound and the film exhibiting optical anisotropy by application of an inorganic layered compound include a film called a temperature compensation type retardation film, "NH film (trade name; film after oblique orientation of rod-like liquid crystal)" sold by JX liquid crystal film co, "WV film (trade name; film after oblique orientation of disk-like liquid crystal)" sold by fuji film co, and "VACfilm (trade name; film of complete biaxial orientation type)" and "new VAC film (trade name; film of biaxial orientation type)" sold by sumitomo chemical co.

The zero retardation film means: front retardation R_eAnd retardation R in the thickness direction_thAll of which are-15 to 15nm and optically isotropic. The zero retardation film may be a resin film made of a cellulose-based resin, a polyolefin-based resin (e.g., a chain polyolefin-based resin or a polycycloolefin-based resin), or a polyethylene terephthalate-based resin, and the cellulose-based resin or the polyolefin-based resin is preferable in that the retardation value can be easily controlled and the film can be easily obtained. The zero retardation film may also be used as a protective film. Examples of the Zero retardation film include "Z-TAC" (trade name) sold by fuji film corporation, "Zero TAC (registered trademark)" sold by Konica MinoltaOpto corporation, and "ZF-14" (trade name) sold by japan ZEON corporation.

In the optical film of the present invention, the retardation film is preferably a retardation film obtained by curing a polymerizable liquid crystal compound.

Examples of the film exhibiting optical anisotropy by coating and aligning a liquid crystalline compound include:

the first mode is as follows: a retardation film in which the rod-like liquid crystal compound is oriented in the horizontal direction with respect to the supporting substrate,

The second mode is as follows: a retardation film in which the rod-like liquid crystal compound is oriented in a direction perpendicular to the supporting substrate,

A third mode: a retardation film in which the orientation direction of the rod-like liquid crystal compound changes in a spiral shape in a plane,

A fourth formula: a retardation film in which a discotic liquid crystal compound is obliquely oriented,

The fifth mode is: a biaxial retardation film comprising a discotic liquid crystal compound oriented in a direction perpendicular to a support base.

For example, the first, second, and fifth embodiments are suitable for use as an optical film used in an organic electroluminescent display. Or they may be used in a stacked manner.

When the retardation film is a layer formed of a polymer in an aligned state of a polymerizable liquid crystal compound (hereinafter, sometimes referred to as "optically anisotropic layer"), the retardation film preferably has reverse wavelength dispersibility. The reverse wavelength dispersibility is an optical property that a retardation value in a liquid crystal alignment plane at a short wavelength is smaller than that at a long wavelength, and it is preferable that the retardation film satisfies the following formulas (7) and (8). In the following, Re (λ) represents an in-plane phase difference value with respect to light having a wavelength λ nm.

Re(450)/Re(550)≤1 (7)

1≤Re(630)/Re(550) (8)

In the optical film of the present invention, when the retardation film is of the first mode and has reverse wavelength dispersibility, coloration at the time of black display in a display device is reduced, and therefore, it is preferable that in the above formula (7), 0.82. ltoreq. Re (450)/Re (550). ltoreq. Re (550) is more preferable. Further preferably 120. ltoreq. Re (550). ltoreq.150.

Examples of polymerizable liquid crystal compounds when the retardation film is a film having an optically anisotropic layer include compounds having a polymerizable group among compounds described in "3.8.6 network (completely crosslinked type)" and "6.5.1 liquid crystal material b. polymerizable nematic liquid crystal material" in the liquid crystal display (edited by the Committee for liquid Crystal display, Takayaku, issued 12 years, 10 months and 30 days), and polymerizable liquid crystal compounds described in Japanese patent application laid-open No. 2010-31223, Japanese patent application laid-open No. 2010-270108, Japanese patent application laid-open No. 2011-6360, Japanese patent application laid-open No. 2011-207765, Japanese patent application laid-open No. 2011-162678, Japanese patent application laid-open No. 2016-open 81035, International publication No. 2017/043438, and Japanese patent application laid-open No. 2011-207765.

Examples of a method for producing a retardation film from a polymer in an aligned state of a polymerizable liquid crystal compound include the method described in jp 2010-31223 a.

In the case of the second embodiment, the front phase difference Re (550) may be adjusted to a range of 0 to 10nm, preferably 0 to 5nm, and the phase difference R in the thickness direction_thIt is only necessary to adjust the particle diameter to a range of-10 to-300 nm, preferably a range of-20 to-200 nm. Thickness-direction phase difference value R indicating thickness-direction refractive index anisotropy_thPhase difference value R measurable by tilting 50 degrees with fast axis in plane as tilting axis₅₀Phase difference value R in sum plane₀And (6) calculating. I.e. from the in-plane phase difference value R₀And a phase difference value R measured by tilting the fast axis by 50 degrees as the tilt axis₅₀Thickness d of retardation film, and average refractive index n of retardation film₀N is obtained from the following equations (10) to (12)_x、n_yAnd n_zBy substituting these into the formula (9), the phase difference value R in the thickness direction can be calculated_th。

R_th＝[(n_x+n_y)/2-n_z]×d (9)

R₀＝(n_x-n_y)×d (10)

R₅₀＝(n_x-n_y′)×d/cos(φ) (11)

(n_x+n_y+n_z)/3＝n₀(12)

In this case, the amount of the solvent to be used,

φ＝sin^-1〔sin(40°)/n₀〕

n_y′＝n_y×n_z/〔n_y ²×sin²(φ)+n_z ²×cos²(φ)〕^1/2

the phase difference film may be a multilayer film having two or more layers. Examples thereof include a multilayer film in which a protective film is laminated on one or both surfaces of a retardation film, and a multilayer film in which two or more retardation films are laminated with an adhesive or a bonding agent interposed therebetween.

When the optical film 40 is a multilayer film in which two or more retardation films are laminated, the optical laminate including the optical film of the present invention may be configured as follows: as shown in fig. 4, the optical film 40 includes a 1/4 wavelength retardation layer 50 that imparts a retardation of 1/4 wavelengths to transmitted light and a 1/2 wavelength retardation layer 70 that imparts a retardation of 1/2 wavelengths to transmitted light, which are laminated with an adhesive or a pressure-sensitive adhesive 60 interposed therebetween. Further, there can be enumerated: as shown in fig. 5, the optical film includes an optical film 40 in which an 1/4 wavelength retardation layer 50a and a positive C layer 80 are laminated with an adhesive layer or a pressure-sensitive adhesive layer interposed therebetween.

The 1/4 wavelength retardation layer 50 that imparts a retardation of 1/4 wavelengths and the 1/2 wavelength retardation layer 70 that imparts a retardation of 1/2 wavelengths to transmitted light in fig. 4 may be the optical film of the first embodiment or the optical film of the fifth embodiment. In the case of the configuration of fig. 4, at least one of the embodiments is more preferably the fifth embodiment.

In the case of the configuration of fig. 5, the 1/4-wavelength retardation layer 50a is preferably the optical film of the first embodiment, and more preferably satisfies the expressions (7) and (8).

[ polarizing film ]

The polarizing film is a film having a function of selectively transmitting linearly polarized light in a certain direction from natural light. Examples thereof include: an iodine-based polarizing film obtained by adsorbing and orienting iodine as a dichroic dye to a polyvinyl alcohol-based resin film, a dye-based polarizing film obtained by adsorbing and orienting a dichroic dye as a dichroic dye to a polyvinyl alcohol-based resin film, and a coating-type polarizing film obtained by coating a dichroic dye in a lyotropic liquid crystal state, orienting and immobilizing the same. These polarizing films selectively transmit linearly polarized light in one direction and absorb linearly polarized light in the other direction from natural light, and are therefore called absorption-type polarizing films. The polarizing film is not limited to the absorption-type polarizing film, and may be a reflection-type polarizing film that selectively transmits linearly polarized light in one direction and reflects linearly polarized light in the other direction from natural light, or a scattering-type polarizing film that scatters linearly polarized light in the other direction. Among these, a polyvinyl alcohol-based polarizing film made of a polyvinyl alcohol-based resin is more preferable, a polyvinyl alcohol-based polarizing film in which a dichroic dye such as iodine or a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film is further preferable, and a polyvinyl alcohol-based polarizing film in which iodine is adsorbed and oriented on a polyvinyl alcohol-based resin film is particularly preferable.

As the polyvinyl alcohol resin constituting the polyvinyl alcohol polarizing film, a polyvinyl alcohol resin obtained by saponifying a polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include polyvinyl acetate which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth) acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal, polyvinyl acetal, or the like modified with aldehydes may be used. The polyvinyl alcohol resin has an average polymerization degree of usually about 1000 to 10000, preferably about 1500 to 5000. The average polymerization degree of the polyvinyl alcohol resin can be determined in accordance with JIS K6726.

The film made of the polyvinyl alcohol resin is used as a raw material film of a polarizing film. The method for forming the film of the polyvinyl alcohol resin is not particularly limited, and a known method can be used. The thickness of the polyvinyl alcohol-based raw material film is, for example, 150 μm or less, preferably 100 μm or less (for example, 50 μm or less).

The polarizing film can be produced by a method including a step of uniaxially stretching a polyvinyl alcohol resin film; a step of dyeing a polyvinyl alcohol resin film with a dichroic dye to adsorb the dichroic dye; a step of treating (crosslinking) the polyvinyl alcohol resin film having the dichroic dye adsorbed thereon with an aqueous boric acid solution; and a step of washing the substrate with water after the treatment with the aqueous boric acid solution.

The uniaxial stretching of the polyvinyl alcohol resin film may be performed before, simultaneously with, or after the dyeing of the dichroic dye. In the case where the uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before boric acid treatment or in boric acid treatment. In addition, uniaxial stretching may be performed in a plurality of stages thereof.

In the case of uniaxial stretching, the uniaxial stretching may be performed between rolls having different peripheral speeds, or the uniaxial stretching may be performed using a hot roll. The uniaxial stretching may be dry stretching in which stretching is performed in the air, or wet stretching in which stretching is performed in a state where the polyvinyl alcohol resin film is swollen with a solvent or water. The draw ratio is usually about 3 to 8 times.

As a method for dyeing a polyvinyl alcohol resin film with a dichroic dye, for example, a method of immersing the film in an aqueous solution containing a dichroic dye can be employed. As the dichroic dye, iodine or a dichroic organic dye is used. The polyvinyl alcohol resin film is preferably subjected to a treatment of immersing in water before the dyeing treatment.

As the dyeing treatment with iodine, a method of immersing a polyvinyl alcohol resin film in an aqueous solution containing iodine and potassium iodide is generally employed. The iodine content in the aqueous solution may be about 0.01 to 1 part by weight relative to 100 parts by weight of water. The content of potassium iodide may be about 0.5 to 20 parts by weight relative to 100 parts by weight of water. The temperature of the aqueous solution may be about 20 to 40 ℃. On the other hand, as the dyeing treatment using the dichroic organic dye, a method of immersing a polyvinyl alcohol resin film in an aqueous solution containing the dichroic organic dye is generally employed. The aqueous solution containing the dichroic organic dye may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The content of the dichroic organic dye in the aqueous solution may be 1 × 10 with respect to 100 parts by weight of water^-4About 10 parts by weight. The temperature of the aqueous solution can be about 20-80 ℃.

As the boric acid treatment after dyeing with the dichroic dye, a method of immersing the dyed polyvinyl alcohol resin film in an aqueous solution containing boric acid is generally employed. In the case of using iodine as the dichroic dye, the aqueous solution containing boric acid preferably contains potassium iodide. The amount of boric acid in the aqueous solution containing boric acid may be about 2 to 15 parts by weight relative to 100 parts by weight of water. The amount of potassium iodide in the aqueous solution may be about 0.1 to 20 parts by weight per 100 parts by weight of water. The temperature of the aqueous solution may be 50 ℃ or higher, for example, 50 to 85 ℃.

The polyvinyl alcohol resin film after the boric acid treatment is usually subjected to a water washing treatment. The water washing treatment can be performed by, for example, immersing the polyvinyl alcohol resin film subjected to the boric acid treatment in water. The temperature of water in the water washing treatment is usually about 5 to 40 ℃. After washing with water, drying treatment is performed to obtain the polarizing film 30. The drying treatment may be performed using a hot air dryer or a far infrared heater. A thermoplastic resin film as a protective film or the like is bonded to one side or both sides of the polarizing film using a curable adhesive composition or the like, whereby a polarizing plate can be obtained.

Further, as another example of the method for producing a polarizing film, there can be mentioned, for example, the methods described in japanese patent application laid-open nos. 2000-338329 and 2012-159778.

The thickness of the polarizing film may be 40 μm or less, preferably 30 μm or less (for example, 20 μm or less, further 15 μm or less, further 10 μm or less). The polarizing film 30 of the film can be produced more easily by the methods described in Japanese patent laid-open Nos. 2000-338329 and 2012-159778, and the thickness of the polarizing film 30 can be made to be, for example, 20 μm or less, further 15 μm or less, and still further 10 μm or less. The thickness of the polarizing film 30 is usually 2 μm or more. Reducing the thickness of the polarizing film is advantageous for thinning the polarizing plate and thus the image display device.

A preferable structure of the polarizing plate is one in which a protective film is laminated on at least one surface of a polarizing film with an adhesive layer interposed therebetween. In the case where a protective film is laminated on only one surface of the polarizing film, it is more preferably laminated on the visible side (the side opposite to the panel). The protective film laminated on the visible side is preferably a protective film formed of a triacetylcellulose-based resin or a cycloolefin-based resin. The protective film may be an unstretched film or may be stretched in any direction to have a retardation. A surface treatment layer such as a hard coat layer, an antiglare layer, or the like may be provided on the surface of the protective film laminated on the visible side. The surface treatment layer may be a light selective absorbing layer in the present invention.

In the case where the protective films are laminated on both sides of the polarizing film, the protective film on the panel side (the side opposite to the visible side) is preferably a protective film or a retardation film formed of a triacetyl cellulose-based resin, a cycloolefin-based resin, or an acrylic resin. The retardation film may be a zero retardation film described later.

Other layers or films may be further laminated between the polarizing plate and the panel. When used as a circularly polarizing plate for an organic EL display, it is preferable to laminate a retardation layer having an 1/4-wavelength retardation layer and a 1/2-wavelength retardation layer, and a 1/4-wavelength layer having reverse wavelength dispersibility described later. The retardation layer is preferably a liquid crystal retardation film from the viewpoint of making the film thinner.

< method for producing light selective absorption layer >

The optical film of the present invention can be produced by applying an active energy ray-curable composition onto the resin film (a) to form a coating film, drying the coating film as needed, and then curing the coating film. The active energy ray-curable composition may have an adhesive function depending on its components.

Examples of the method of forming a coating film by applying the active energy ray-curable composition include various known methods such as a spin coating method, a dipping method, a spray coating method, a die coating method, a bar coating method, a roll coater method, a meniscus coater method, a flexo printing method, a screen printing method, and a droplet coater method.

The drying method is not particularly limited, but generally, it is preferably carried out at a drying temperature of 30 to 80 ℃ for a drying time of 3 to 120 seconds. If the drying temperature is less than 30 ℃, the production of the surface-treated film may take a long time, and the production cost may increase. On the other hand, if the drying temperature exceeds 80 ℃, there is a problem that the production cost of the surface-treated film increases, and there is a risk that an initiator, a solvent, or the like adheres to the inside of the drying furnace or the like to deteriorate the appearance. If the drying time is less than 3 seconds, the adhesion between the base film and the surface-treated layer may be poor or interference fringes may occur. On the other hand, if the drying time exceeds 120 seconds, the drying of the coating film may take a long time, which may increase the production cost.

The irradiation intensity of the active energy ray is determined according to the curable composition, and it is preferable that the irradiation intensity in a wavelength region effective for activation of the photopolymerization initiator is 0.1 to 1000mW/cm². If the light irradiation intensity is too low, the reaction time becomes too long, while if the light irradiation intensity is too high, yellowing of the cured layer, deterioration of the polarizing film, and surface defects of the protective film may occur due to heat radiated from the lamp and heat generation during polymerization of the curable composition. The time for irradiating the curable composition with light is also controlled depending on the curable composition, and the cumulative light amount represented by the product of the intensity of light irradiation and the time of light irradiation is preferably 10 to 5000mJ/cm²The mode of (2). If the cumulative light amount is too small, the generation of active species from the photopolymerization initiator may become insufficient, and the curing of the cured layer obtained may be insufficient.

(display device)

The optical film of the present invention can be laminated on a display element such as an organic EL element or a liquid crystal cell and used for a display device (FPD: flat panel display) such as an organic EL display device or a liquid crystal display device.

Examples

The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples,% and parts indicating contents or amounts are by weight unless otherwise specified.

< Synthesis of light Selective absorbing Compound >

Synthesis example 1 Synthesis of light-selective absorbing Compound (1)

A200 mL-four-necked flask equipped with a serpentine condenser and a thermometer was placed in a nitrogen atmosphere, and 10g of the compound represented by the formula (aa) synthesized by reference to the patent document (Japanese unexamined patent publication No. 2014-194508), 3.6g of acetic anhydride (manufactured by Wako pure chemical industries, Ltd.), 6.9g of 2-ethylhexyl cyanoacetate (manufactured by Tokyo Kasei Co., Ltd.), and 60g of acetonitrile (manufactured by Wako pure chemical industries, Ltd.) were charged and stirred with a magnetic stirrer. 4.5g of DIPEA (manufactured by Tokyo chemical industry Co., Ltd.) was added dropwise from the addition funnel at an internal temperature of 25 ℃ over 1 hour, and after completion of the addition, the mixture was further kept at an internal temperature of 25 ℃ for 2 hours. After completion of the reaction, acetonitrile was removed by a reduced pressure evaporator, and the product was subjected to column chromatography (silica gel) for purification, and the solvent was removed from the effluent containing the photoselective absorbent compound represented by the formula (aa1) by a reduced pressure evaporator to obtain yellow crystals. By drying the crystals at 60 ℃ under reduced pressure, 4.6g of the light selective absorbing compound (1) represented by the formula (aa1) was obtained as a yellow powder. The yield thereof was found to be 50%.

To carry out¹The formation of the photoselective absorption compound 1 was confirmed by H-NMR analysis, which showed the following peaks.

¹H-NMR(CDCl3)δ：0.87-0.94(m、6H)、1.32-1.67(m、8H)、1.59-1.66(m、2H)、2.09(quin、2H)、3.00(m、5H)、3.64(t、2H)、4.10(dd、2H)、5.52(d、2H)、7.87(d、2H)

< measurement of the extinction coefficient ε >

In order to measure the gram absorption coefficient of the obtained light selective absorbing compound (1), the light selective absorbing compound (1) was dissolved in 2-butanone. The resulting solution (concentration: 0.006 g.L)^-1) Adding into 1cm quartz cuvette, placing the quartz cuvette in a spectrophotometer UV-2450 (Shimadzu corporation), and measuring absorbance at 1nm step distance and 300-800 nm wavelength by double-beam method. From the obtained absorbance values, the concentrations of the light-absorbing compounds in the solutions, and the optical path lengths of the quartz cuvettes, the gram absorption coefficients at the respective wavelengths were calculated using the following formulas.

ε(λ)＝A(λ)/CL

[ in the formula, [ epsilon ] (lambda) ] represents the gram absorption coefficient L/(g.cm) of the compound at a wavelength of lambda nm, A (lambda) represents the absorbance at a wavelength of lambda nm, C represents the concentration g/L, and L represents the optical path length cm of the quartz cuvette. Angle (c)

As a result of measuring the absorption maximum wavelength (λ max) of the photo-selective absorbent compound (1), λ max was 389nm (in 2-butanone), the value of ∈ (405) was 47L/(g · cm), the value of ∈ (440) was 0.1L/(g · cm) or less, and the value of ∈ (405)/∈ (440) was 80 or more.

Synthesis example 2 Synthesis of light-selective absorbing Compound (2)

In a 200 mL-four-necked flask equipped with a serpentine condenser and a thermometer, 10g of the compound represented by the formula (aa) synthesized by reference to Japanese patent application laid-open No. 2014-194508, 3.6g of acetic anhydride (available from Wako pure chemical industries, Ltd.), 10g of 2-butyloctyl cyanoacetate (available from Tokyo Kasei Co., Ltd.), and 60g of acetonitrile (available from Wako pure chemical industries, Ltd.) were charged under a nitrogen atmosphere, and stirred with a magnetic stirrer. To the resulting mixture was added dropwise DIPEA (manufactured by Tokyo chemical industry Co., Ltd.) 4.5g at an internal temperature of 25 ℃ over 1 hour, and the mixture was further kept at an internal temperature of 25 ℃ for 2 hours. Thereafter, acetonitrile was removed by a reduced pressure evaporator, and subjected to purification by column chromatography (silica gel), and the effluent containing the compound represented by the formula (aa2) was subjected to solvent removal by a reduced pressure evaporator to obtain yellow crystals. The crystals were dried under reduced pressure at 60 ℃ to obtain 4.6g of the compound represented by the formula (aa2) (light selective absorbing compound (2)) as a yellow powder. The yield thereof was found to be 56%.

When the gram absorbance coefficient was determined by the same method as described above, the value of ε (405) and ε (420) of the compound represented by formula (aa2) were 45L/(g cm) and 2.1L/(g cm).

< preparation of active energy ray-curable resin composition >

Preparation example 1 preparation of active energy ray-curable resin composition A1

The active energy ray-curable resin composition a1 was prepared by mixing the components in the following proportions.

Preparation example 2 preparation of active energy ray-curable resin composition A2

The active energy ray-curable resin composition a1 was prepared by mixing the components in the following proportions.

Preparation example 3 preparation of active energy ray-curable resin composition B

The active energy ray-curable resin composition B was prepared by mixing the respective components in the following proportions.

Example 1 production of optical film A1

2 resin films (trade name "ZEONOR", manufactured by japan ZEON corporation) of a cyclic polyolefin resin having a thickness of 23 μm were prepared; hereinafter, the resin film is sometimes referred to as COP resin film. And (c) a temperature sensor. The surface of the COP resin film was subjected to corona discharge treatment, and an active energy ray-curable resin composition a1 was applied to the corona discharge-treated surface using a bar coater so that the cured film thickness became about 5.0 μm. Another 1 COP resin film was also subjected to a corona discharge treatment on the surface thereof, the corona discharge treated surface was brought into contact with the surface coated with the active energy ray-curable resin composition A, and an ultraviolet irradiation apparatus with a conveyor belt was used (lamp "H valve" manufactured by Fusion UV Systems Co., Ltd.) so as to obtain an illuminance of 250mW/cm²The cumulative light amount was 250mJ/cm²(UVB) methodThe optical film A1 was obtained by irradiating ultraviolet rays. The optical film a1 had a layer composition of a cured layer of COP resin film/active energy ray-curable resin composition a 1/COP resin film.

Example 2 production of optical film A2

An optical film a2 was produced in the same manner as in example 1, except that the active energy ray-curable resin composition was replaced with the active energy ray-curable resin composition a2 obtained in production example 2. The optical film a2 had a layer composition of a cured layer of COP resin film/active energy ray-curable resin composition a 2/COP resin film.

Production example 1 production of polarizing film

A polyvinyl alcohol film having an average polymerization degree of about 2400 and a saponification degree of 99.9 mol% and a thickness of 30 μm (trade name "Kuraray vinyl VF-PE # 3000" manufactured by Kuraray corporation) was immersed in pure water at 37 ℃ and then immersed in an aqueous solution containing iodine and potassium iodide (iodine/potassium iodide/water (weight ratio): 0.04/1.5/100) at 30 ℃. Thereafter, the substrate was immersed in an aqueous solution containing potassium iodide and boric acid (potassium iodide/boric acid/water (weight ratio): 12/3.6/100) at 56.5 ℃. The film was washed with pure water at 10 ℃ and then dried at 85 ℃ to obtain a polarizing plate having a thickness of about 12 μm in which iodine was adsorbed and oriented to polyvinyl alcohol. The stretching was mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching magnification was 5.3 times.

Example 3 production of polarizing plate A1

A resin film (trade name "ZEONOR", manufactured by japan ZEON corporation) made of a cyclic polyolefin resin having a thickness of 23 μm; hereinafter, the resin film may be referred to as COP resin film. Corona discharge treatment was performed on the surface, and active energy ray-curable resin composition A1 was applied to the corona discharge treated surface using a bar coater so that the film thickness after curing was about 5.0. mu.m. The polarizing film produced in production example 1 was laminated on the coated surface to obtain a polarizing film (1) with a protective film.

Then, a retardation film (trade name "KC 4 CW", manufactured by Konica Minolta) having a thickness of 40 μm and made of a triacetylcellulose resin was applied; hereinafter sometimes referred to as TAC film. Surface of the steel bar was subjected to corona discharge treatment using a bar coaterThe corona discharge-treated surface was coated with active energy ray-curable resin composition A1 so that the cured film thickness was about 5.0. mu.m. The coated surface was bonded to the polarizing film side of the polarizing film (1) with a protective film to obtain a laminate. An ultraviolet irradiation apparatus with a conveyor belt (lamp "H Valve" manufactured by Fusion UV Systems) was used, and the illuminance was 250mW/cm from the protective film side of the laminate²The cumulative light amount was 250mJ/cm²The curable adhesive composition was cured by irradiation with ultraviolet light in the form of (UVB) to produce a polarizing plate. This was set as polarizing plate a 1. The polarizing plate a1 had a structure of a cured layer of COP resin film/active energy ray-curable resin composition a 1/a cured layer of polarizing film/active energy ray-curable resin composition a 1/a TAC film.

Example 4 production of polarizing plate A2

A polarizing plate a2 was produced in the same manner as in example 3, except that the active energy ray-curable resin composition was replaced with the active energy ray-curable resin composition a 2. The polarizing plate a2 had a structure of a cured layer of COP resin film/active energy ray-curable resin composition a 2/a cured layer of polarizing film/active energy ray-curable resin composition a 2/a TAC film.

Comparative example 1 production of polarizing plate B

A polarizing plate B was produced in the same manner as the polarizing plate a except that the active energy ray-curable resin composition was changed to the active energy ray-curable resin composition B. The polarizing plate B has a composition of COP resin film/cured layer of active energy ray-curable resin composition B/polarizing film/cured layer of active energy ray-curable resin composition B/TAC film.

(Synthesis example 3 Synthesis of (meth) acrylic resin

A solution obtained by mixing 81.8 parts of ethyl acetate as a solvent, 70.4 parts of butyl acrylate as a monomer, 20.0 parts of methyl acrylate, 8.0 parts of 2-phenoxyethyl acrylate, 1.0 part of 2-hydroxyethyl acrylate, and 0.6 part of acrylic acid was charged into a reaction vessel equipped with a condenser tube, a nitrogen inlet tube, a thermometer, and a stirrer. The air in the reaction vessel was replaced with nitrogen, and the internal temperature was adjusted to 60 ℃. Then, a solution prepared by dissolving 0.12 part of azobisisobutyronitrile in 10 parts of ethyl acetate was added. After the reaction mixture was kept at this temperature for 1 hour, ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts/Hr so that the polymer concentration became approximately 35% while keeping the internal temperature at 54 to 56 ℃. After the internal temperature was maintained at 54 to 56 ℃ for 12 hours from the start of the addition of ethyl acetate, ethyl acetate was added to adjust the polymer concentration to 20% to obtain an ethyl acetate solution of a (meth) acrylic resin. The (meth) acrylic resin had a weight average molecular weight Mw of 139 ten thousand and a ratio Mw/Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 5.32.

The weight average molecular weight and the number average molecular weight were measured by placing a total of 5 of 4 "TSK gel XL (manufactured by tokyo corporation)" and 1 "Shodex GPC KF-802 (manufactured by showa electric corporation)" as columns in series on a GPC device, eluting with tetrahydrofuran under conditions of a sample concentration of 5mg/mL, a sample introduction amount of 100 μ L, a temperature of 40 ℃, a flow rate of 1 mL/min, and calculating in terms of standard polystyrene.

(Synthesis example 4 Synthesis of (meth) acrylic resin adhesive composition A

To an ethyl acetate solution (resin concentration: 20%) of the (meth) acrylic resin obtained in Synthesis example 3, 0.4 parts of a crosslinking agent (Coronate L, 75% solids, manufactured by Tosoh corporation) and 0.4 parts of a silane compound (KBM-403, manufactured by shin-Etsu chemical Co., Ltd.) were mixed with respect to 100 parts of the solid content of the solution, and ethyl acetate was added so that the solid content concentration was 14% to obtain a pressure-sensitive adhesive composition. The amount of the crosslinking agent is the weight part of the active ingredient.

The details of the crosslinking agent and the silane compound used in synthesis example 4 are as follows.

A crosslinking agent: an ethyl acetate solution (solid content concentration: 75%) of a trimethylolpropane adduct of tolylene diisocyanate, and a product name "Coronate L" obtained from tokyo co.

Silane compound: 3-glycidoxypropyltrimethoxysilane, trade name "KBM 403" available from shin-Etsu chemical Co.

< preparation of adhesive layer A >

The pressure-sensitive adhesive composition A was applied to a release-treated surface of a release film (trade name "PLR-382190" obtained from LINTEC corporation) comprising a polyethylene terephthalate film, which had been subjected to release treatment, using an applicator so that the thickness after drying was 20 μm, and dried at 100 ℃ for 1 minute to prepare a pressure-sensitive adhesive layer A.

Synthesis example 5 Synthesis of (meth) acrylic resin adhesive composition B1

To an ethyl acetate solution (resin concentration: 20%) of the (meth) acrylic resin obtained in synthesis example 3, 0.4 parts of a crosslinking agent (Coronate L, 75% of a solid content, manufactured by tokyo co., ltd.), 0.4 parts of a silane compound (KBM-403, manufactured by shin-Etsu chemical Co., Ltd.) and 2 parts of the light selective absorbing compound (1) obtained in synthesis example 1 were mixed with respect to 100 parts of the solid content of the solution, and ethyl acetate was added so that the solid content concentration became 14%, to obtain an adhesive composition B1. The amount of the crosslinking agent is the weight part of the active ingredient.

(Synthesis example 6 Synthesis of (meth) acrylic resin adhesive composition B2

An adhesive composition B2 was obtained in the same manner as in synthesis example 5, except that 1 part of the light selective absorbing compound (2) was used in place of 2 parts of the light selective absorbing compound (1).

< preparation of adhesive layer B1 >

Adhesive composition B1 was applied to a release-treated surface of a release-treated separation film (trade name "PLR-382190" obtained from linec corporation) comprising a polyethylene terephthalate film using a coater so that the dried thickness was 20 μm, and dried at 100 ℃ for 1 minute to prepare adhesive layer B1.

Adhesive layer B2 was prepared in the same manner except that adhesive composition B1 was replaced with adhesive composition B2.

< preparation of polarizing plate with adhesive layer >

Example 5 production of polarizing plate with adhesive layer A1

The surface of the triacetyl cellulose resin film of the polarizing plate a1 was subjected to corona treatment, the adhesive layer a thus produced was laminated by a laminator, and then cured at 23 ℃ and 65% relative humidity for 7 days to obtain a polarizing plate a1 with an adhesive layer.

Example 6 production of polarizing plate with adhesive layer A2

A polarizing plate a2 with an adhesive layer was obtained in the same manner as in example 5, except that the polarizing plate a1 was replaced with the polarizing plate a 2.

Comparative example 2 production of polarizing plate with adhesive layer B1

The surface of the triacetyl cellulose resin film of the polarizing plate B was subjected to corona treatment, the adhesive layer B1 produced above was bonded by a laminator, and then cured at 23 ℃ and 65% relative humidity for 7 days to obtain a polarizing plate B1 with an adhesive layer.

Comparative example 3 production of polarizing plate with adhesive layer B2

Polarizing plate B2 with an adhesive layer was obtained in the same manner as in comparative example 2, except that the adhesive layer B1 was replaced with an adhesive layer B2.

< measurement of Absorbance of optical film >

The optical film a1 was cut into a size of 30mm × 30mm, which was made into a sample. The absorbance of the sample was measured in the wavelength range of 300 to 800nm using a spectrophotometer (UV-2450, manufactured by Shimadzu corporation). The results are shown in table 1.

The samples after measurement were stored in an oven at a temperature of 95 ℃ for 48 hours, and a heat resistance evaluation test was performed. The absorbance of the sample after storage was measured, and the absorbance retention was determined based on the absorbance retention of the optical film a1 by the following formula. The results are shown in table 1. The higher the absorbance retention ratio, the more excellent the heat resistance is exhibited without deterioration of the light selective absorption function. The absorbance of the COP resin film monomer was substantially 0.

Absorbance retention rate (a (405) after durability test/a (405) before durability test) x 100

The absorbance was measured in the same manner as described above except that the optical film a1 was replaced with the optical film a 2. The results are shown in table 1.

[ Table 1]

< measurement of Absorbance of polarizing plate with adhesive >

Polarizing plate a1 with an adhesive layer was cut into a size of 30mm × 30mm, and the adhesive layer was laminated with alkali-free glass (trade name "EAGLE XG" manufactured by corning corporation) to prepare a sample. The absorbance of the sample was measured in the wavelength range of 300 to 800nm using a spectrophotometer (UV-2450, manufactured by Shimadzu corporation). A (405) is 0.6, A (440) is 0.05, and A (405)/A (440) is 12.7.

The samples after measurement were stored in an oven at a temperature of 95 ℃ for 48 hours, and a heat resistance evaluation test was performed. The absorbance of the sample after storage was measured, and the absorbance retention of the polarizing plate a1 with a pressure-sensitive adhesive layer was determined in the same manner as described above. The result was 94%.

The absorbance at a wavelength of 405nm and at a wavelength of 440nm of each of the TAC film monomer, the COP resin film monomer, and the alkali-free glass is substantially 0.

The absorbance was measured by the same method as described above except that the polarizing plate a1 with an adhesive layer was replaced with the polarizing plate a2 with an adhesive layer. As a result, A (405) was 0.5, A (440) was 0.05, A (405)/A (440) was 9.5, and the absorbance retention ratio was 98%.

< evaluation of transferability of light selective absorption Compound >

The transferability of the light selective absorbing compound transferred to the film was evaluated by the following method.

Device name: fourier transform Infrared Spectrophotometer Cary 660 FTIR (manufactured by Agilent Technologies)

The method comprises the following steps: ATR method (Crystal: diamond) using MCT (cadmium Mercury telluride) as detector

From the implementation ofTriacetyl cellulose was peeled off from the polarizing plate a1 produced in example 3, and FTIR measurement was performed on the peeled triacetyl cellulose surface by the ATR method. 1550 to 1560cm from the light selective absorbing compound (1) was observed^-1Peak of (2).

Then, the polarizing plate A1 was stored in an oven at a temperature of 95 ℃ for 48 hours, and FTIR measurement was carried out in the same manner, and 1550 to 1560cm from the light selective absorbing compound (1) was not observed on the triacetyl cellulose side^-1Increase in peak of (a).

Since no increase in the peak derived from the light selective absorbing compound (1) was observed in the surface layer of the triacetyl cellulose surface after heating, it was judged that the light selective absorbing compound (1) did not migrate. The results are shown in table 2.

The adhesive layer was physically removed from the polarizing plate B1 produced in comparative example 2, and the triacetyl cellulose surface after removal was confirmed by the above method, and it was confirmed that 1550 to 1560cm was obtained from the light selective absorbing compound (1)^-1Peak of (2).

Then, after the polarizing plate B1 was stored in an oven at a temperature of 95 ℃ for 48 hours, FTIR measurement was performed in the same manner, and 1550 to 1560cm from the light selective absorbing compound (1) was confirmed on the triacetyl cellulose surface^-1Increase in peak of (a).

Since an increase in the peak derived from the light selective absorbing compound (1) was observed in the triacetyl cellulose surface layer after heating, it was judged that the light selective absorbing compound (1) was shifted. The results are shown in table 2.

The transferability of the light selective absorbing compound in the polarizing plate a1 produced in example 3 and the polarizing plate B2 produced in comparative example 3 was evaluated in the same manner as described above. The results are shown in table 2.

[ Table 2]

The optical film of the present invention has a high function of selectively absorbing light having a wavelength of around 400nm (405nm), and can suppress deterioration of a retardation film or the like without causing a compound that selectively absorbs light having a wavelength of around 400nm (405nm) to migrate into another layer.

Industrial applicability

The optical film of the present invention has excellent display characteristics and can suppress deterioration of the optical film due to short-wavelength visible light.

Description of the reference numerals

10 optical film

10A, 10B, 10C optical laminate

1 light selective absorption layer

2 resin film (a)

3 polarizing film

4. 7, 60 adhesive layer

5 protective film

6 polarizing film

30 adhesive layer

40 optical film

50. 50a 1/4 wavelength phase difference layer

701/2 wavelength phase difference layer

80 positive C layer

110 light emitting element

Claims (11)

1. An optical film comprising at least 1 light selective absorbing layer formed of an active energy ray-curable composition and satisfying the following formula (1),

A(405)≥0.5 (1)

in the formula (1), A (405) represents the absorbance at a wavelength of 405 nm.

2. The optical film according to claim 1, further satisfying the following formula (2),

A(440)≤0.1 (2)

in the formula (2), A (440) represents the absorbance at a wavelength of 440 nm.

3. The optical film according to claim 1 or 2, which satisfies the following formula (3),

A(405)/A(440)≥5 (3)

in the formula (3), A (405) represents the absorbance at a wavelength of 405nm, and A (440) represents the absorbance at a wavelength of 440 nm.

4. The optical film according to any one of claims 1 to 3, wherein the storage modulus E of the light selective absorption layer at 23 ℃ is 100MPa or more.

5. The optical film according to any one of claims 1 to 4, wherein the light selective absorption layer is a layer formed from an active energy ray-curable composition containing a photocurable component (A), a light selective absorption compound (B) and a photopolymerization initiator (C).

6. The optical film according to claim 5, wherein the content of the light selective absorbing compound (B) is 0.01 to 20 parts by mass with respect to 100 parts by mass of the photocurable component (A).

7. The optical film according to claim 5 or 6, wherein the light selective absorbing compound (B) is a compound satisfying the following formula (4),

ε(405)≥20 (4)

in the formula (4), (405) represents a gram absorption coefficient of the compound at a wavelength of 405nm, and the unit of the gram absorption coefficient is L/(g · cm).

8. The optical film according to claim 7, wherein the light selective absorbing compound (B) is a compound satisfying formula (5),

ε(405)/ε(440)≥20 (5)

in the formula (5), (405) represents the gram absorption coefficient of the compound at a wavelength of 405nm, and ε (440) represents the gram absorption coefficient at a wavelength of 440 nm.

9. The optical film according to any one of claims 6 to 8, wherein the photocurable component (A) comprises at least 1 selected from a (meth) acryloyloxy group-containing compound and an epoxy compound.

10. An optical film with an adhesive layer, comprising the optical film according to claims 1 to 9 and an adhesive layer on at least one side of the optical film.

11. A display device having the optical film with an adhesive layer according to claim 10.

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