CN114846376A

CN114846376A - Optical laminate and image display device

Info

Publication number: CN114846376A
Application number: CN202080089258.7A
Authority: CN
Inventors: 神野亨; 浅津悠司; 白石贵志
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2019-12-23
Filing date: 2020-11-30
Publication date: 2022-08-02
Also published as: WO2021131507A1; TW202132108A; JP2021099478A; KR20220116288A

Abstract

The invention provides a novel optical laminate in which discoloration of the edge of a polarizing plate under high temperature and high humidity conditions is suppressed. An optical stack comprising: the adhesive composition for forming the light selective absorbing adhesive layer includes a polarizing plate, a light selective absorbing adhesive layer, and an intermediate layer laminated between the polarizing plate and the light selective absorbing adhesive layer in contact therewith, the intermediate layer having only one or more layers selected from a liquid crystal cured layer, an alignment layer, and a bonding layer, the polarizing plate having iodine adsorbed thereto and aligned thereto and having a boron content of 5.0 mass% or less, and the adhesive composition for forming the light selective absorbing adhesive layer includes a light selective absorbing polymer.

Description

Optical laminate and image display device

Technical Field

The present invention relates to an optical laminate and an image display device.

Background

Polarizing plates obtained by laminating a protective film on one or both surfaces of a polarizer are widely used as optical members of image display devices such as mobile devices, liquid crystal display devices typified by televisions, and organic electroluminescence (organic EL) display devices, and in particular, various mobile devices such as mobile phones, smart phones, and tablet terminals in recent years.

Polarizing plates are often used by being bonded to an image display element (a liquid crystal cell, an organic EL display element, or the like) via an adhesive layer (for example, japanese patent application laid-open No. 2010-229321 (patent document 1)). Therefore, polarizing plates are sometimes marketed as adhesive layer-attached polarizing plates having an adhesive layer provided on one surface thereof in advance.

In addition, mobile devices are often used in severe environments of high temperature and high humidity, and high durability is required as a polarizing plate. Japanese patent laid-open publication No. 2013-105036 (patent document 2) describes that increasing the boric acid content in a polarizing plate causes a large amount of boric acid crosslinking, thereby producing I ₃ The complex exists in high orientation and high stability, the occurrence of blue leakage is suppressed, and a polarizing plate having excellent low-temperature high-humidity durability can be obtained.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2010-229321

Patent document 2: japanese patent laid-open publication No. 2013-105036

Disclosure of Invention

Problems to be solved by the invention

In the polarizing plate, there was a problem that discoloration (japanese: color removal け) easily occurred at the end portion of the polarizer in an environment of high temperature and high humidity. This problem is significant in a structure in which a protective film is laminated and bonded to only one surface of a polarizing plate. Although a method of increasing the boron content in the polarizing plate to suppress discoloration of the polarizing plate is known, this method has a problem that it is easily shrunk by heating.

The purpose of the present invention is to provide a novel optical laminate in which discoloration at the ends of a polarizing plate is suppressed under high temperature and high humidity conditions.

Means for solving the problems

The present invention provides an optical laminate exemplified below and an image display device using the optical laminate.

[1] An optical stack comprising: a polarizing plate, a light selective absorbing adhesive layer, and an intermediate layer laminated between the polarizing plate and the light selective absorbing adhesive layer in contact therewith,

the intermediate layer has only one or more layers selected from a cured liquid crystal layer, an alignment layer, and a laminating layer,

the polarizing plate is adsorbed with iodine, oriented with the content of boron being 5.0 mass% or less,

the adhesive composition forming the above-mentioned light selective absorbing adhesive layer contains a light selective absorbing polymer.

[2] The optical laminate according to [1], further comprising a protective film laminated on a side of the polarizing plate opposite to the intermediate layer side.

[3] The optical laminate according to [1] or [2],

the light selective absorbing polymer is a resin which contains a structural unit having a structure represented by the following chemical formula (1) and has a glass transition temperature of 40 ℃ or lower,

＞N-C＝C-C＝C＜ (1)

wherein not all of the N atom and the four C atoms constituting the formula (1) constitute a part or all of the aromatic heterocyclic ring.

[4] The optical laminate according to [3],

in the light selective absorbing polymer, the content of the structural unit having the structure represented by the above chemical formula (1) is 0.01 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the total structural units.

[5] The optical laminate according to any one of claims 1 to 4,

the weight average molecular weight of the light selective absorbing polymer is 30 ten thousand or more.

[6] The optical laminate according to any one of [1] to [5],

the adhesive composition does not contain a light selective absorber, or the content of the light selective absorber is 0.5 parts by mass or less with respect to 100 parts by mass of the total resin components in the adhesive composition.

[7] The optical laminate according to any one of [1] to [6],

the intermediate layer has a lambda/4 phase difference layer as the liquid crystal cured layer.

[8] The optical laminate according to any one of [1] to [7], which is a polarizing plate for antireflection.

[9] An image display device, comprising: and (3) the optical laminate according to [8] disposed on the front surface of the image display panel.

[10] The image display device according to [9], which is an organic EL display device.

Effects of the invention

According to the present invention, an optical laminate in which discoloration at the ends of a polarizing plate is suppressed under a high-temperature and high-humidity environment, and an image display device including the optical laminate can be provided.

Drawings

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

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

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

Fig. 4 is a diagram showing an example of an observation image by an optical microscope.

Fig. 5 is a diagram showing an example of data obtained by converting an observation image into a black-and-white 256 level.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In all the drawings below, the scale of each component is appropriately adjusted to facilitate understanding of the component, and the scale of each component shown in the drawings does not necessarily coincide with the scale of the actual component.

< optical laminate >

The optical laminate of the present invention includes a polarizing plate, a light selective absorbing adhesive layer, and an intermediate layer laminated between the polarizing plate and the light selective absorbing adhesive layer in contact therewith. Fig. 1,2, and 3 show examples of the layer structure of the optical laminate of the present invention.

Fig. 1 is a schematic cross-sectional view of an example of the optical laminate of the present invention. The optical laminate 100 shown in fig. 1 includes, in order: a protective film 11, a polarizing plate 10, an intermediate layer 300, and a light selective absorbing adhesive layer (hereinafter, also referred to as "first adhesive layer") 20. The intermediate layer 300 has only one or more layers selected from a liquid crystal cured layer, an alignment layer, and a lamination layer.

Fig. 2 is a schematic cross-sectional view of an example of the optical laminate of the present invention. The optical laminate 101 shown in fig. 2 includes, in order: a protective film 11, a polarizing plate 10, an intermediate layer 300, and a light selective absorbing adhesive layer 20. The intermediate layer 300 includes a second pressure-sensitive adhesive layer 32, a first liquid crystal cured layer 30, an adhesive layer 33, and a second liquid crystal cured layer 31 in this order from the polarizer 10 side.

Fig. 3 is a schematic cross-sectional view of an example of the optical laminate of the present invention. The optical laminate 102 shown in fig. 3 includes, in order: a protective film 11, a polarizing plate 10, an intermediate layer 300, and a light selective absorbing adhesive layer 20. The intermediate layer 300 is formed of the second adhesive layer 32.

The thickness of the optical

layered bodies

100, 101, and 102 is not particularly limited, and is, for example, 5 μm or more and 200 μm or less, 10 μm or more and 150 μm or less, and 120 μm or less, since it varies depending on the functions required for the optical layered bodies, the applications of the optical layered bodies, and the like.

The light selective absorbing adhesive layer includes a light selective absorbing polymer. The optical laminate of the present invention has at least a light selective absorption property in the light selective absorption adhesive layer, and thus has a light selective absorption property as a whole of the optical laminate. The light selective absorption property refers to a property of easily absorbing light of a specific wavelength, and has at least one absorption maximum value from an ultraviolet wavelength region to a visible light region. For example, when the light selective absorbing pressure-sensitive adhesive layer has ultraviolet absorbing ability, the optical laminate disposed on the image display element has a function of protecting the image display element from ultraviolet rays.

The optical laminate of the present invention may have a structure including a layer having a light selective absorption property in addition to the light selective absorption adhesive layer. Examples of the other layers include the protective film 11 and the intermediate layer 300. In the present invention, the light selective absorbing adhesive layer has a light selective absorbing property, and contributes to the integrity of the optical laminateSince the structure of the body exhibits the light selective absorption performance, the degree of freedom in designing the light selective absorption performance in the other layer can be increased. For example, although the protective film 11 may need to be designed to have a larger thickness in order to improve the light selective absorption performance, the protective film 11 can be easily made thinner because of a high degree of freedom in designing the light selective absorption performance. For example, from the viewpoint of suppressing discoloration of the edge portion of the polarizing plate under high temperature and high humidity, the intermediate layer 300 preferably has a structure substantially not containing a light selective absorber, and when containing a light selective absorber, the content thereof is preferably 0.5g/m ² The following. When the intermediate layer 300 has a second pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer is also preferably configured to contain substantially no light-selective absorber, and when the intermediate layer contains a light-selective absorber, the content is preferably 0.5g/m ² The following.

The light selective absorbing adhesive layer has a structure in which the light selective absorbing polymer has a light selective absorbing property and contributes to the expression of the light selective absorbing property of the light selective absorbing adhesive layer, so that the light selective absorbing adhesive layer can be configured not to contain a light selective absorbing agent or configured to have a reduced content of the light selective absorbing agent, and discoloration of the edge portion of the polarizing plate under high temperature and high humidity can be suppressed.

The present inventors have obtained a finding that there is a correlation between the content of the light selective absorber contained in the pressure-sensitive adhesive layer and the degree of discoloration of the edge portion of the polarizing plate under high temperature and high humidity conditions. Based on this insight, it can be considered that: in the case where a light selective absorber having a relatively low molecular weight is used, the light selective absorber in the adhesive layer is likely to move to the polarizer side under high temperature and high humidity, and this movement is one of the main causes of occurrence of discoloration. The present inventors have further made extensive studies and found that discoloration of the edge portion of a polarizing plate under high temperature and high humidity can be suppressed by a method of using a polymer containing a light selective absorbing agent, rather than a method of imparting a light selective absorbing property to an adhesive layer by adding a light selective absorbing agent, and have completed the present invention. Since the molecular weight of the light selective absorbing polymer is relatively large, migration to the polarizing plate is suppressed, and discoloration at the end of the polarizing plate is suppressed.

[ polarizing plate ]

The polarizing plate had the following properties: linearly polarized light having a vibration plane parallel to the absorption axis thereof is absorbed, and linearly polarized light having a vibration plane orthogonal to the absorption axis (parallel to the transmission axis) is transmitted. The polarizing plate 10 in the optical laminate of the present invention adsorbs iodine, orients iodine, and has a boron content of 5.0 mass% or less.

With a boron content of 5.0 mass% or less, preferably 4.5 mass% or less, shrinkage due to heating can be suppressed. The content of boron is preferably 0.5 mass% or more, and more preferably 1 mass% or more. In the polarizing plate 10, the less the content of boron, the more likely discoloration of the end portion of the polarizing plate under high temperature and high humidity occurs. Since boron in the polarizing plate 10 increases the degree of crosslinking of the polarizing plate 10 and contributes to stable iodine retention in the polarizing plate 10, it is considered that if the content of boron is reduced, iodine cannot be stably retained and discoloration occurs. In the present invention, the polarizing plate 10 can suppress discoloration under high temperature and high humidity even if the boron content is 5.0 mass% or less.

Examples of the polarizing plate 10 include: a stretched film or a stretched layer having absorbed thereon a dichroic dye having absorption anisotropy, a cured product of a polymerizable liquid crystal compound, a liquid crystal cured layer of a dichroic dye, and the like. The dichroic dye is a dye having a property that the absorbance of molecules in the major axis direction is different from the absorbance of molecules in the minor axis direction, and iodine is preferably used as the dye.

A polarizing plate as a stretched film having a dye having absorption anisotropy adsorbed thereon can be usually produced through the following steps: a step of uniaxially stretching a polyvinyl alcohol resin film; a step of dyeing a polyvinyl alcohol resin film with a dichroic dye such as iodine to adsorb the dichroic dye; treating 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 thickness of the polarizing plate is usually 30 μm or less, preferably 15 μm or less, more preferably 13 μm or less, still more preferably 10 μm or less, and particularly preferably 8 μm or less. The thickness of the polarizing plate is usually 2 μm or more, preferably 3 μm or more, and for example, may be 5 μm or more.

The polyvinyl alcohol resin is obtained by saponifying a polyvinyl acetate resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable with vinyl acetate may be used. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acid compounds, olefin compounds, vinyl ether compounds, unsaturated sulfone compounds, and (meth) acrylamide compounds having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually about 85 mol% or more and 100 mol% or less, and preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, or polyvinyl formal, polyvinyl acetal, or the like modified with aldehydes may be used. The polymerization degree of the polyvinyl alcohol resin is usually 1000 or more and 10000 or less, and preferably 1500 or more and 5000 or less.

A polarizing plate having a stretched layer having a dye having absorption anisotropy adsorbed thereon can be generally produced through the following steps: a step of applying a coating liquid containing the polyvinyl alcohol resin onto a base film; a step of uniaxially stretching the obtained laminated film; a step of dyeing the polyvinyl alcohol resin layer of the uniaxially stretched laminate film with a dichroic dye such as iodine to adsorb the dichroic dye to form a polarizing plate; treating the 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. A substrate film for forming a polarizing plate may also be used as the protective film 11. The substrate film may be peeled off from the polarizing plate as necessary. The material and thickness of the base film may be the same as those of the protective film 11 described later.

[ protective film ]

The protective film 11 may be formed as a coating or film made of: optically transparent thermoplastic resins such as cyclic polyolefin resins; cellulose acetate resins containing resins such as cellulose triacetate and cellulose diacetate; polyester resins including resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; a polycarbonate-based resin; (meth) acrylic resins; polypropylene-based resins, and mixtures of one or more of these resins. The protective film 11 may contain a light selective absorber described later. The light selective absorber contained in the protective film 11 is held in the protective film 11, and thus is less likely to move to the polarizing plate.

A hard coat layer may be formed on the protective film 11. The hard coat layer may be formed on one surface of the protective film 11 or on both surfaces. By providing the hard coat layer, the protective film 11 having improved hardness and scratch resistance can be produced. The hard coat layer may be a cured layer of, for example, acrylic resin, silicone resin, polyester resin, polyurethane resin, amide resin, epoxy resin, or the like. The hard coating may contain additives for the purpose of improving strength. The additive is not limited, and examples thereof include inorganic fine particles, organic fine particles, and a mixture thereof. The hard coat layer is a cured layer of, for example, an ultraviolet curable resin. Examples of the ultraviolet curable resin include acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins.

The thickness of the protective film 11 is usually 1 μm or more and 100 μm or less, and from the viewpoint of strength and handling properties, it is preferably 5 μm or more and 80 μm or less, more preferably 8 μm or more and 60 μm or less, and still more preferably 12 μm or more and 45 μm or less.

The resin film as the protective film 11 is bonded to the polarizing plate 10 via, for example, an adhesive layer. Examples of the adhesive for forming the adhesive layer include an aqueous adhesive, an active energy ray-curable adhesive, and a thermosetting adhesive, and the aqueous adhesive and the active energy ray-curable adhesive are preferably used. The opposing surfaces bonded via the adhesive layer may be subjected to corona treatment, plasma treatment, flame treatment, or the like in advance, and may have a primer layer or the like.

[ light-selective absorbing adhesive layer ]

The light selective absorbing adhesive layer 20 can be formed by dissolving or dispersing the binder composition containing the light selective absorbing polymer in an organic solvent, applying the obtained diluted solution to a substrate, and drying. The substrate is preferably a plastic film, and specifically, a release film subjected to a release treatment is exemplified. Examples of the release film include those obtained by subjecting one surface of a film made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyarylate to a mold release treatment such as a silicone treatment.

The thickness of the light selective absorbing adhesive layer is, for example, 0.1 μm or more and 150 μm or less. When the pressure-sensitive adhesive layer is laminated on an image display panel, the thickness of the light-selective absorbing pressure-sensitive adhesive layer is usually 8 μm or more and 60 μm or less, and is preferably 30 μm or less, more preferably 25 μm or less, and particularly preferably 20 μm or less from the viewpoint of reduction in thickness. When the pressure-sensitive adhesive layer is laminated with another optical film, for example, a λ/4 retardation layer, the thickness of the light-selective absorbing pressure-sensitive adhesive layer is usually 2 μm or more and 30 μm or less, preferably 25 μm or less, more preferably 20 μm or less, particularly preferably 18 μm or less, preferably 3 μm or more, and for example, may be 10 μm or more, and from the viewpoint of further thinning, preferably 10 μm or less, and particularly preferably 7 μm or less.

The absorbance of the light selective absorbing adhesive layer 20 at a wavelength of 410nm is preferably 0.1 to 1.6. This is because the light selective absorbing pressure-sensitive adhesive layer 20 having such absorbance exhibits a desired light selective absorbing performance as the entire optical laminate, and the entire optical laminate can be easily made thin.

The absorbance of the light selective absorbing pressure-sensitive adhesive layer at a wavelength of 390nm is usually 5.0 or less, and may be 4.5 or less.

The absorbance of the light selective absorbing pressure-sensitive adhesive layer at a wavelength of 400nm is usually 5.0 or less, and may be 4.5 or less.

The absorbance of the light selective absorbing adhesive layer at a wavelength of 420nm is usually 1.00 or less, preferably 0.60 or less, more preferably 0.40 or less, and 0.00 or more.

The absorbance of the light selective absorbing adhesive layer at a wavelength of 430nm is usually less than 0.20, preferably 0.18 or less, more preferably 0.10 or less, particularly preferably 0.05 or less, and 0.00 or more.

The absorbance of the light selective absorbing adhesive layer at a wavelength of 440nm is usually less than 0.10, preferably 0.05 or less, and 0.00 or more. By setting the absorbance at each wavelength within the above range, light in the ultraviolet region can be sufficiently absorbed, and light in the visible light region can be directly transmitted.

The light selective absorbing adhesive layer is preferably an adhesive layer satisfying the following formula (3), and more preferably an adhesive layer also satisfying the formula (4).

A(405)≥0.5 (3)

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

A(405)/A(440)≥5 (4)

[ in the formula (4), A (405) represents the absorbance at a wavelength of 405nm, and A (440) represents the absorbance at a wavelength of 440 nm. ]

A larger value of A (405) indicates a higher absorption at a wavelength of 405 nm. If the value of A (405) is less than 0.5, the absorption at a wavelength of 405nm is low, and deterioration of members (for example, a display device such as an organic EL element, a liquid crystal retardation film, and the like) which are easily deteriorated by light in the vicinity of 400nm is likely to occur. 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 upper limit is not particularly limited, but is usually 10 or less.

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 440nm, and a larger value indicates specific absorption in a wavelength region near 405 nm. The value of a (405)/a (440) is preferably 10 or more, more preferably 30 or more, further preferably 75 or more, and particularly preferably 100 or more.

[ adhesive composition ]

(light-selective absorbing Polymer)

The adhesive composition comprises a light selective absorbing polymer. The light selective absorbing polymer is a polymer having light selective absorbing properties. The light selective absorbing polymer preferably absorbs light having a wavelength in the range of 360nm to 420 nm. The light selective absorbing polymer includes a light selective absorbing structural unit having a site having a light selective absorbing property. The light selective absorbing structural unit preferably has a site having light selective absorbing properties in a side chain. Examples of the site having a light selective absorption property include a benzophenone group, a benzotriazole group, a structure represented by the following chemical formula (1), and the like.

The light selective absorbing polymer is preferably a resin (a) which contains, as a light selective absorbing structural unit, a structural unit having a structure represented by the following chemical formula (1) (hereinafter, referred to as "merocyanine structure") and has a glass transition temperature of 40 ℃ or lower,

＞N-C＝C-C＝C＜ (1)

[ in the formula, one N atom and four C atoms constituting the chemical formula (1) are not all members constituting a part or all of the aromatic heterocyclic ring. ].

The resin (a) may have a merocyanine structure in the main chain or may have such a structure in the side chain. The resin (a) more preferably contains a structural unit having a merocyanine structure in a side chain.

The glass transition temperature (Tg) of the resin (A) is 40 ℃ or lower, preferably 20 ℃ or lower, more preferably 10 ℃ or lower, and still more preferably 0 ℃ or lower. The glass transition temperature of the resin (A) is usually-80 ℃ or higher, preferably-60 ℃ or higher, more preferably-50 ℃ or higher, still more preferably-45 ℃ or higher, and particularly preferably-30 ℃ or higher. When the glass transition temperature of the resin (a) is 40 ℃ or lower, it is advantageous to improve the adhesion of the light selective absorbing adhesive layer formed from the adhesive composition containing the resin (a) to an adherend. In addition, if the glass transition temperature of the resin (A) is-80 ℃ or higher, it is advantageous to improve the durability (poor appearance at the time of high temperature test: cohesive failure, etc.) of the light selective absorbing adhesive layer formed of the adhesive composition containing the resin (A). The glass transition temperature can be measured by a Differential Scanning Calorimeter (DSC).

The structural unit having a merocyanine structure in a side chain is not particularly limited, and is preferably a structural unit derived from a compound having a polymerizable group and a merocyanine structure.

The compound having a polymerizable group and a merocyanine structure preferably satisfies the following formula (1-a), and more preferably also satisfies formula (2-a).

ε(405)≥5 (1-a)

[ in the formula (1-a), [ epsilon ] (405) represents the molar absorption coefficient of a compound having a polymerizable group and a merocyanine structure at a wavelength of 405 nm. The molar absorptivity was expressed in L/(g.cm). ]

ε(405)/ε(440)≥20 (2-a)

[ in the formula (2-a), [ epsilon ] (405) represents the molar absorption coefficient of the compound having a polymerizable group and a merocyanine structure at a wavelength of 405nm, and [ epsilon ] (440) represents the molar absorption coefficient of the compound having a polymerizable group and a merocyanine structure at a wavelength of 440 nm. ]

The value of ∈ (405) of the compound having a polymerizable group and a merocyanine structure is preferably 5L/(g · cm) or more, more preferably 10L/(g · cm) or more, still more preferably 20L/(g · cm) or more, still more preferably 30L/(g · cm) or more, and usually 500L/(g · cm) or less. The larger the value of epsilon (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 visible light having a short wavelength.

The value of ∈ (405)/∈ (440) of the compound having a polymerizable group and a merocyanine structure is preferably 20 or more, more preferably 40 or more, still more preferably 70 or more, and particularly preferably 80 or more. A resin containing a compound having a large value of ∈ (405)/∈ (440) can absorb light near 405nm without inhibiting color development of a display device, and can suppress light degradation of a display device such as a retardation film or an organic EL element.

Examples of the structural unit having a merocyanine structure in a side chain include structural units derived from a compound represented by formula (I).

[ chemical formula 1]

[ in the formula (I), R ¹ 、R ² 、R ³ 、R ⁴ And R ⁵ Each independently represents a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 25 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 15 carbon atoms, a heterocyclic group or an ethylenically unsaturated group, -CH contained in the aliphatic hydrocarbon group or the aromatic hydrocarbon group ₂ Optionally substituted by-NR ^1A -、-SO ₂ -, -CO-, -O-or S-substitution.

R ⁶ And R ⁷ Each independently represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, an electron-withdrawing group or an ethylenically unsaturated group.

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

R ¹ And R ² Optionally linked to each other to form a ring structure, R ² And R ³ Optionally linked to each other to form a ring structure, R ² And R ⁴ Optionally linked to each other to form a ring structure, R ³ And R ⁶ Optionally linked to each other to form a ring structure, R ⁵ And R ⁷ Optionally linked to each other to form a ring structure, R ⁶ And R ⁷ Optionally joined to each other to form a ring structure.

Wherein R is ¹ ～R ⁷ Is an ethylenically unsaturated group]

As R ¹ ～R ⁵ The aliphatic hydrocarbon group having 1 to 25 carbon atoms includes: a straight-chain or branched alkyl group having 1 to 25 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a tert-butyl group, a sec-butyl group, a n-pentyl group, an isopentyl group, a n-hexyl group, an isohexyl group, a n-octyl group, an isooctyl group, a n-nonyl group, an isononyl group, a n-decyl group, an isodecyl group, a n-dodecyl group, an isododecyl group, an undecyl group, a lauryl group, a myristyl group, a cetyl group, a stearyl group, etc.; cycloalkyl groups having 3 to 25 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and the like; cyclohexylmethylA C4-25 cycloalkylalkyl group such as a cycloalkyl group, preferably a C4-25 alkyl group.

As R ¹ ～R ⁵ The optional substituent of the aliphatic hydrocarbon group having 1 to 25 carbon atoms includes a hydroxyl group, a cyano group, a halogen atom, a mercapto group, an amino group, a nitro group, and the like.

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

As R ¹ ～R ⁵ The aromatic hydrocarbon group having 6 to 15 carbon atoms includes aryl groups having 6 to 15 carbon atoms such as phenyl, naphthyl, anthryl and biphenyl groups; and aralkyl groups having 7 to 15 carbon atoms such as benzyl, phenethyl, naphthylmethyl, and phenyl.

As R ¹ ～R ⁵ The optional substituent of the aromatic hydrocarbon group having 6 to 15 carbon atoms includes a hydroxyl group, a cyano group, a halogen atom, a mercapto group, an amino group, a nitro group, an alkoxy group, an alkylthio group, an alkoxycarbonyl group, an acyl group, an acyloxy group and a-C (NR) ^2A )R ^2B 、-CONR ^3A R ^3B 、-SO ₂ R ^4A (R ^2A 、R ^2B 、R ^3A And R ^3B Each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R ^4A Represents an alkyl group having 1 to 6 carbon atoms. ) And the like.

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

Examples of the alkoxy group include alkoxy groups having 1 to 12 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, and a dodecyloxy group.

The alkylthio group includes alkylthio groups having 1 to 12 carbon atoms such as a methylthio group, an ethylthio group, a propylthio group, and a butylthio group.

Examples of the acyl group include acyl groups having 2 to 13 carbon atoms such as an acetyl group, a propionyl group, and a butyryl group.

Examples of the acyloxy group include acyloxy groups having 2 to 13 carbon atoms such as a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group and a 2-ethylhexylcarbonyloxy group.

Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 13 carbon atoms such as a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, a butoxycarbonyl group, a pentoxycarbonyl group, a hexyloxycarbonyl group, an octyloxycarbonyl group, a 2-ethylhexyloxycarbonyl group, a nonyloxycarbonyl group, a decyloxycarbonyl group, an undecyloxycarbonyl group, a dodecyloxycarbonyl group and the like.

as-CONR ^3A R ^3B Examples thereof include aminocarbonyl group, methylaminocarbonyl group, dimethylaminocarbonyl group, ethylaminocarbonyl group, and methylaminocarbonyl group.

as-C (NR) ^2A )R ^2B Examples thereof include methylimino, dimethylimino and methylethylimino.

as-SO ₂ R ^4A Examples thereof include methylsulfonyl group and ethylsulfonyl group.

As R ^1A And R ^1B Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, sec-butyl and the like.

As R ¹ ～R ⁵ Examples of the heterocyclic group include an aliphatic heterocyclic group having 4 to 20 carbon atoms such as a pyrrolidine ring group, a pyrroline ring group, an imidazolidine ring group, an imidazoline ring group, an oxazoline ring group, a thiazoline ring group, a piperidine ring group, a morpholine ring group, a piperazine ring group, an indole ring group, an isoindoline ring group, a quinoline ring group, a thiophene ring group, a pyrrole ring group, a thiazoline ring group, and a furan ring group, and an aromatic heterocyclic group having 3 to 20 carbon atoms.

As R ⁶ And R ⁷ Examples of the alkyl group having 1 to 25 carbon atoms include a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a tert-butyl group, a sec-butyl group, a n-pentyl group, an isopentyl group, a n-hexyl group, an isohexyl group, a n-octyl group, an isooctyl group, a n-nonyl group, an isononyl group, a n-decyl group, an isodecyl group, a n-dodecyl group, an isododecyl group, an undecyl group, a lauryl group, a myristyl group, a cetyl group, and a stearyl groupLinear or branched alkyl groups having a sub-number of 1 to 25.

As R ⁶ And R ⁷ Examples 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).

[ chemical formula 2]

*-X ¹ -R ¹¹¹ (I-1)

[ in the formula, R ¹¹¹ Represents a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms, and at least one of methylene groups contained in the alkyl group is optionally replaced by an oxygen atom.

X ¹ represents-CO- ¹ 、-COO-* ¹ 、-CS-* ¹ 、-CSS-* ¹ 、-CSNR ¹¹² -* ¹ 、-CONR ¹¹³ -* ¹ 、-CNR ¹¹⁴ -* ¹ Or SO ₂ -* ¹ 。

R ¹¹² 、R ¹¹³ And R ¹¹⁴ Each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.

* ¹ Is represented by the formula ¹¹¹ The connecting bond of (1).

Denotes a bond to a carbon 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 R ¹¹¹ Examples of the hydrocarbon group having 1 to 25 carbon atoms include: a straight-chain or branched alkyl group having 1 to 25 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, a tert-butyl group, a sec-butyl group, a n-pentyl group, an isopentyl group, a n-hexyl group, an isohexyl group, a n-octyl group, an isooctyl group, a n-nonyl group, an isononyl group, a n-decyl group, an isodecyl group, a n-dodecyl group, an isododecyl group, an undecyl group, a lauryl group, a myristyl group, a cetyl group, a stearyl group, and the like: cyclopropyl radicalCycloalkyl groups having 3 to 25 carbon atoms such as a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group; a C4-25 cycloalkylalkyl group such as a cyclopropylmethyl group or a cyclohexylmethyl group; aryl groups having 6 to 25 carbon atoms such as phenyl, naphthyl, anthryl and biphenyl groups; aralkyl groups having 7 to 25 carbon atoms such as benzyl, phenethyl, naphthylmethyl and phenyl.

As R ¹¹² 、R ¹¹³ And R ¹¹⁴ Examples of the alkyl group having 1 to 6 carbon atoms include the group represented by the formula ^1A The same alkyl groups having 1 to 6 carbon atoms.

R ¹¹¹ Preferably an alkyl group having 4 to 25 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms.

X ¹ preferably-CO- ¹ And COO- ¹ 。

R ⁶ And R ⁷ The electron-withdrawing groups represented by the formula (I) are each independently preferably a cyano group or a group represented by the formula (I-1).

As R ¹ And R ² Examples of the ring structures formed by bonding to each other include: comprising R ¹ And R ² A nitrogen-containing ring structure of the bonded nitrogen atom, for example, a 4-to 10-membered nitrogen-containing heterocycle. R ¹ And R ² The 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. R ¹ And R ² The ring formed by bonding to each other may optionally have a substituent, and examples of the substituent include: alkyl groups having 1 to 12 carbon atoms such as methyl, ethyl, propyl, butyl, isobutyl, etc.; and C1-12 alkoxy groups such as methoxy, ethoxy, propoxy and butoxy groups.

As R ² And R ³ Examples of the ring structures formed by bonding to each other include: comprising R ² A nitrogen-containing ring structure of the bonded nitrogen atom, for example, a 4-to 10-membered nitrogen-containing heterocycle. R ² And R ³ The ring structure formed by the mutual connection may be a single ring or multiple rings. Specific examples thereof include pyrrolidine ring, pyrroline ring, and pyridine ring,Imidazolidine ring, imidazoline ring, oxazoline ring, thiazoline ring, piperidine ring, morpholine ring, piperazine ring, indole ring, isoindole ring, and a ring structure represented by the following formula (I-3).

[ chemical formula 3]

[ in the formula (I-3), X represents a nitrogen atom, an oxygen atom or a sulfur atom.

Ring W ¹ Represents a ring having a nitrogen atom and X as constituent elements.]

Ring W ¹ A5-or 6-membered ring having a nitrogen atom and X as components is preferred.

Specific examples of the ring structure represented by the formula (I-3) include the following rings.

[ chemical formula 4]

R ² And R ³ The ring structures formed by bonding to each other may optionally have a substituent, and examples of the substituent include: alkyl groups having 1 to 12 carbon atoms such as methyl, ethyl, propyl, butyl, isobutyl, etc.; and C1-12 alkoxy groups such as methoxy, ethoxy, propoxy and butoxy groups.

R ² And R ³ The ring structures bonded to each other are preferably ring structures represented by the following formula (I-4).

[ chemical formula 5]

[ in the formula (I-4), R ¹¹ The same meanings as described above are indicated. m2 represents an integer of 1 to 7.

R ^11a 、R ^11b 、R ^11c And R ^11d Each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

Denotes a bond to a carbon atom. ]

m2 is preferably 2 or 3, more preferably 2.

As R ² And R ⁴ Examples of the ring structure formed by bonding to each other include a nitrogen-containing ring structure having 4 to 10 members, preferably 5 to 9 members. R is ² And R ⁴ The ring structures formed by bonding to each other may be monocyclic or polycyclic. These rings optionally have a substituent. Examples of such a ring structure include an azole ring, an indole ring, a pyrimidine ring, and the following rings.

[ chemical formula 6]

R ² And R ⁴ The ring structures formed by bonding to each other may optionally have a substituent, and examples of the substituent include: alkyl groups having 1 to 12 carbon atoms such as methyl, ethyl, propyl, butyl, isobutyl, etc.; alkoxy groups having 1 to 12 carbon atoms such as methoxy, ethoxy, propoxy and butoxy; amino, methylamino, dimethylamino and the like-NR ^22A R ^22B A group of (R) ^22A And R ^22B Each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms); alkylthio groups having 1 to 12 carbon atoms such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, and the like; and a C4-9 heterocyclic group such as a pyrrolidinyl group, a piperidinyl group, or a morpholinyl group.

As R ³ And R ⁶ Examples of the ring structure formed by the mutual connection include R ³ -C＝C-C＝C-R ⁶ A ring structure forming the backbone of the ring. Examples thereof include phenyl groups.

As R ⁵ And R ⁷ The ring structures formed by the mutual connection include the following ring structures. R is ⁵ And R ⁷ The ring structure formed by bonding to each other optionally has a substituent, and examples of the substituent include an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, a propyl group, a butyl group, and an isobutyl group; methoxy, ethoxy and propylAlkoxy group having 1 to 12 carbon atoms such as oxy group and butoxy group.

[ chemical formula 7]

As R ⁶ And R ⁷ The ring structures formed by the mutual connection include the following ring structures. R is ⁶ And R ⁷ The ring structures formed by bonding to each other may have a substituent (R in the following formula) ₁ ～R ₁₆ ) Examples of the substituent include: alkyl groups having 1 to 12 carbon atoms such as methyl, ethyl, propyl, butyl, isobutyl, etc.; alkoxy groups having 1 to 12 carbon atoms such as methoxy, ethoxy, propoxy and butoxy; an ethylenically unsaturated group described later, and the like.

[ chemical formula 8]

[ in the formula, a represents a bond to a carbon atom. ]

As R ¹ ～R ⁷ Examples of the ethylenically unsaturated group include a vinyl group, an α -methylvinyl group, an acryloyl group, a methacryloyl group, an allyl group, a styryl group and a group represented by the formula (I-2).

[ chemical formula 9]

*-R ¹¹⁵ -X ² (I-2)

[ in the formula (I-2), X ² Represents a vinyl group, an acryloyl group or a methacryloyl group.

R ¹¹⁵ Represents a divalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, the aliphatic hydrocarbon group containing-CH ₂ Optionally substituted by-O-, -CO-, -CS-or NR ¹¹⁶ -a permutation.

R ¹¹⁶ Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

Denotes a bond to a carbon atom or a nitrogen atom. ]

As R ¹¹⁵ Of the representationExamples of the divalent aliphatic hydrocarbon group having 1 to 18 carbon atoms include: alkane diyl groups having 1 to 18 carbon atoms such as a methylene group, an ethylene group, a propane-1, 3-diyl group, a propane-1, 2-diyl group, a butane-1, 4-diyl group, a pentane-1, 5-diyl group, a hexane-1, 6-diyl group, a butane-1, 3-diyl group, a 2-methylpropane-1, 2-diyl group, a pentane-1, 4-diyl group and a 2-methylbutane-1, 4-diyl group; a cycloalkanediyl group having 3 to 18 carbon atoms such as a cyclopropanediyl group, a cyclobutanediyl group, a cyclopentanediyl group, and a cyclohexanediyl group, and a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms is preferable.

As R ¹¹⁶ Examples of the alkyl group having 1 to 6 carbon atoms include the group represented by the formula ^1A The same alkyl groups having 1 to 6 carbon atoms.

R ¹ ～R ⁷ The ethylenically unsaturated groups represented by (A) are each independently preferably a vinyl group, an acryloyl group, a methacryloyl group, and a group represented by the formula (I-2).

R ⁶ And R ⁷ Any of these is preferably an electron withdrawing group.

R ⁶ And R ⁷ Any of these are preferably ethylenically unsaturated groups.

The structural unit derived from the compound represented by the formula (I) is preferably a structural unit derived from the compound represented by the formula (II).

[ chemical formula 10]

[ in the formula (II), R ¹¹ 、R ¹² 、R ¹³ 、R ¹⁴ And R ¹⁵ Each independently represents a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 25 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 15 carbon atoms or a heterocyclic group, or-CH contained in the aliphatic hydrocarbon group or the aromatic hydrocarbon group ₂ Optionally substituted by-NR ^11A -、-SO ₂ -, -CO-, -O-or S-substitution.

R ¹⁶ And R ¹⁷ Each independently represents a hydrogen atom or a carbon atom1 to 25 alkyl groups, electron-withdrawing groups or ethylenically unsaturated groups.

R ^11A Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

R ¹² And R ¹³ Optionally linked to each other to form a ring structure, R ¹² And R ¹⁴ Optionally joined to each other to form a ring structure.

Wherein R is ¹⁶ Or R ¹⁷ Any of which is an ethylenically unsaturated group.]

As R ¹¹ ～R ¹⁵ The C1-25 aliphatic hydrocarbon group optionally having a substituent(s) is represented by ¹ The aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent(s) is the same.

As R ¹¹ ～R ¹⁵ The aromatic hydrocarbon group having 6 to 15 carbon atoms which is optionally substituted is represented by ¹ The aromatic hydrocarbon group having 6 to 15 carbon atoms which is optionally substituted.

As R ¹¹ ～R ¹⁵ Examples of the heterocyclic ring include ¹ The heterocyclic rings shown are the same heterocyclic rings.

As R ¹⁶ And R ¹⁷ The alkyl group having 1 to 25 carbon atoms is represented by ⁶ The alkyl groups having 1 to 25 carbon atoms are the same.

As R ¹⁶ And R ¹⁷ The electron-withdrawing group represented by (A) is represented by ⁶ The electron-withdrawing groups are the same as the electron-withdrawing groups shown.

As R ^11A And R ^11B Examples of the alkyl group having 1 to 6 carbon atoms include the group represented by the formula ^1A The same alkyl groups having 1 to 6 carbon atoms.

As R ¹² And R ¹³ Examples of the ring structure which can be formed by connecting R and R ² And R ³ The ring structures are connected to each other to form the same ring structure. R ¹² And R ¹³ The ring structure that can be formed by connecting the rings is preferably a single ring structure.

As R ¹² And R ¹⁴ Examples of the ring structure which can be formed by connecting R and R ² And R ⁴ The ring structures are connected to each other to form the same ring structure. R ¹² And R ¹⁴ The ring structure that can be formed by connecting the rings is preferably a single ring structure. R is ¹² And R ¹⁴ The ring structure that can be formed by connecting them is preferably an aromatic ring, and more preferably a pyrimidine ring structure.

R ¹¹ 、R ¹³ And R ¹⁵ Independently of each other, the aliphatic hydrocarbon group having 1 to 25 carbon atoms is preferably an optionally substituted aliphatic hydrocarbon group, more preferably an optionally substituted alkyl group having 1 to 25 carbon atoms, and still more preferably an optionally substituted alkyl group having 1 to 12 carbon atoms.

Especially as R ¹¹ The aliphatic hydrocarbon group has 1 to 10 carbon atoms, preferably an alkyl group has 1 to 10 carbon atoms, and more preferably a methyl group.

Preferably, R is ¹² And R ¹⁴ Each independently is an optionally substituted aliphatic hydrocarbon group having 1 to 25 carbon atoms, R ¹² And R ¹⁴ Are connected to form a ring structure.

R ¹² And R ¹³ The ring structures are preferably connected to each other to form a ring structure, and more preferably a ring structure represented by the above formula (I-4). Among the ring structures represented by the formula (I-4), the ring structure represented by the formula (I-4-1) or the ring structure represented by the formula (I-4-2) is preferable, and the ring structure represented by the formula (I-4-1) is particularly preferable.

[ chemical formula 11]

Preferably R ¹⁶ And R ¹⁷ Either of which is an ethylenically unsaturated group and the other is an electron withdrawing group.

R ¹⁶ And R ¹⁷ The electron-withdrawing groups represented by the formula (I) are each independently preferably a cyano group, a nitro group, a fluoro group, a trifluoromethyl group, or a group represented by the formula (I-1). Cyano is particularly preferred.

R ¹⁶ And R ¹⁷ The ethylenically unsaturated groups represented by (A) are each independently preferably a vinyl group, an acryloyl group, a methacryloyl group, and a group represented by the formula (I-2). Further preferred is-CO-O- (CH) ₂ )n-X ² 、(X ² Represents a vinyl group, an acryloyl group or a methacryloyl group, and n represents an integer of 1 to 10 (preferably n is an integer of 2 to 6). ).

As R ¹² And R ¹³ The compound represented by the formula (II) which is linked to each other to form a ring structure is preferably a compound represented by the formula (II-A-1) or a compound represented by the formula (II-A-2). As R ¹² And R ¹⁴ The compound represented by the formula (II) which is linked to each other to form a ring structure is preferably a compound represented by the formula (II-B-1).

[ chemical formula 12]

[ formula (II-A-1), formula (II-A-2) and formula (II-B-1) wherein R ¹¹ 、R ¹⁴ 、R ¹⁵ 、R ¹⁶ And R ¹⁷ Each represents the same meaning as described above.

R ^11e 、R ^11f 、R ^11g 、R ^11h 、R ^11k 、R ^11m 、R ¹¹ⁿ Each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

R ^11q And R ^11p Each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, -NR ^22A R ^22B A group of (R) ^22A And R ^22B Each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms) or a heterocycle.]

For example, the compound represented by the formula (II) in which the electron-withdrawing group is a cyano group can be obtained by reacting a compound represented by the following formula (I') with a compound represented by the formula (L).

[ chemical formula 13]

[ in the formula, R ²²² Represents a divalent linking group, X ² Represents a polymerizable group.]

The reaction of the compound represented by the formula (I') with the compound represented by the formula (L) can be carried out under any conditions used in the usual knoevenagel (Japanese: クネフェナーゲル) condensation. For example, it is preferably carried out in the presence of a base or a carboxylic acid anhydride. Examples of the base include: triethylamine, N-diisopropylethylamine, pyridine, piperidine, pyrrolidine, proline, N-dimethylaminopyridine, imidazole, sodium hydroxide, potassium carbonate, sodium bicarbonate, potassium tert-butoxide, sodium hydride and the like. Examples of the carboxylic anhydride include acetic anhydride, succinic anhydride, phthalic anhydride, maleic anhydride, and benzoic anhydride. The amount of the base to be used is preferably 0.1 to 10 moles based on 1 mole of the compound represented by the formula (I'). The amount of acetic anhydride used is preferably 0.2 to 5 moles per 1 mole of the compound represented by formula (I').

The reaction of the compound represented by the formula (I') with the compound represented by the formula (L) is preferably carried out in an organic solvent. Examples of the organic solvent include toluene, acetonitrile, dichloromethane, and chloroform.

The reaction of the compound represented by the formula (I ') with the compound represented by the formula (L) is carried out by mixing the compound represented by the formula (I') with the compound represented by the formula (L).

The reaction temperature of the compound represented by the formula (I') and the compound represented by the formula (L) is preferably-40 to 130 ℃ and the reaction time is preferably 1 to 24 hours.

The compound represented by the formula (I') can be synthesized, for example, by the method described in Japanese patent laid-open No. 2014-194508.

The compound represented by the formula (L) can be obtained, for example, by reacting cyanoacetic acid with a hydroxyalkyl acrylate.

The amount of cyanoacetic acid used is preferably 0.5 to 3 moles per 1 mole of hydroxyalkyl acrylate.

The reaction of cyanoacetic acid with hydroxyalkyl acrylate may be carried out using any esterification catalyst used in the usual esterification reaction, but is preferably carried out in the presence of a base and a carbodiimide condensing agent. Examples of the base include triethylamine, diisopropylethylamine, pyridine, piperidine, pyrrolidine, proline, N-dimethylaminopyridine, imidazole, sodium hydroxide, potassium carbonate, sodium hydrogen carbonate, potassium tert-butoxide, sodium hydride and the like. Examples of the carbodiimide condensing agent include N, N-dicyclohexylcarbodiimide, N-diisopropylcarbodiimide, and 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride. The amount of the base to be used is preferably 0.5 to 5 mol based on 1mol of cyanoacetic acid.

The reaction of cyanoacetic acid with hydroxyalkyl acrylate is preferably carried out in an organic solvent. Examples of the organic solvent include acetonitrile, isopropanol, toluene, chloroform, and dichloromethane.

The reaction of the cyanoacetic acid with the hydroxyalkyl acrylate is carried out by mixing the cyanoacetic acid with the hydroxyalkyl acrylate.

The reaction temperature of the cyanoacetic acid and the hydroxyalkyl acrylate is preferably-40 to 130 ℃, and the reaction time is usually 1 to 24 hours.

Examples of the compound having a polymerizable group and a merocyanine structure include the compounds described below.

[ chemical formula 14]

[ chemical formula 15]

[ chemical formula 16]

[ chemical formula 17]

[ chemical formula 18]

[ chemical formula 19]

[ chemical formula 20]

The resin (a) may be a homopolymer having a structural unit having a merocyanine structure in a side chain, or may be a copolymer including a structural unit having a merocyanine structure in a side chain and another structural unit. The resin (a) is preferably a copolymer.

Examples of the structural unit that the resin (a) may contain in addition to the structural unit having a merocyanine structure in the side chain include structural units described in the following group a.

Group A: a structural unit derived from a (meth) acrylate, a structural unit derived from a styrenic monomer, a structural unit derived from a vinyl monomer, a structural unit represented by the formula (a), a structural unit represented by the formula (b), and a structural unit represented by the formula (c)

[ chemical formula 21]

[ in the formula, R ^a1 Represents a divalent hydrocarbon group.

R ^b1 And R ^b2 Each independently represents a hydrogen atom or a hydrocarbon group.

R ^c1 And R ^c2 Each independently represents a divalent hydrocarbon group.]

Examples of the (meth) acrylate include: linear alkyl esters of (meth) acrylic acid such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate, lauryl (meth) acrylate, and stearyl (meth) acrylate; branched alkyl esters of (meth) acrylic acid such as isopropyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, isoamyl (meth) acrylate, isohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isostearyl (meth) acrylate, and isoamyl (meth) acrylate; alkyl esters containing an alicyclic skeleton of (meth) acrylic acid such as cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cyclododecyl (meth) acrylate, methylcyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, and cyclohexyl α -ethoxyacrylate; aromatic ring skeleton-containing esters of (meth) acrylic acid such as phenyl (meth) acrylate; and so on.

Examples of the structural unit derived from a (meth) acrylate include a substituent-containing alkyl (meth) acrylate in which a substituent is introduced into an alkyl group in the alkyl (meth) acrylate. The substituent of the alkyl (meth) acrylate having a substituent is a group in which a hydrogen atom of an alkyl group is substituted, and specific examples thereof include a phenyl group, an alkoxy group, and a phenoxy group. Specific examples of the alkyl (meth) acrylate containing a substituent include 2-methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2- (2-phenoxyethoxy) ethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, and phenoxypoly (ethylene glycol) meth (acrylate).

These (meth) acrylates may be used alone or in combination of two or more.

The resin (a) of the present invention preferably contains: a constituent unit derived from an alkyl (meth) acrylate (a1) having a homopolymer glass transition temperature Tg of less than 0 ℃ and a constituent unit derived from an alkyl (meth) acrylate (a2) having a homopolymer Tg of 0 ℃ or higher. This is advantageous in improving the high-temperature durability of the adhesive layer. The Tg of the homopolymer of the alkyl (meth) acrylate can be obtained, for example, from literature values of POLYMER HANDBOOK (Wiley-Interscience) and the like.

Specific examples of the alkyl (meth) acrylate (a1) include: alkyl (meth) acrylates having an alkyl group of about 2 to 12 carbon atoms such as ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate, isohexyl acrylate, n-heptyl acrylate, n-octyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate, isononyl acrylate, n-decyl acrylate, isodecyl acrylate, and n-dodecyl acrylate.

The alkyl (meth) acrylate (a1) may be used alone or in combination of two or more. Among them, n-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate and the like are preferable from the viewpoint of followability and reworkability when laminated on an optical film.

The alkyl (meth) acrylate (a2) is an alkyl (meth) acrylate other than the alkyl (meth) acrylate (a 1). Specific examples of the alkyl (meth) acrylate (a2) include methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, stearyl acrylate, t-butyl acrylate, and the like.

The alkyl (meth) acrylate (a2) may be used alone or in combination of two or more. Among them, the alkyl (meth) acrylate (a2) preferably contains methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, and the like, and more preferably contains methyl acrylate, from the viewpoint of high-temperature durability.

Further, as the structural unit derived from a (meth) acrylate, a structural unit derived from a (meth) acrylate having a polar functional group can be also cited.

Examples of the (meth) acrylate monomer having a polar functional group include: 1-hydroxymethyl (meth) acrylate, 1-hydroxyethyl (meth) acrylate, 1-hydroxyheptyl (meth) acrylate, 1-hydroxybutyl (meth) acrylate, 1-hydroxypentyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypentyl (meth) acrylate, 2-hydroxyhexyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 3-hydroxypentyl (meth) acrylate, 3-hydroxyhexyl (meth) acrylate, 3-hydroxyheptyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 4-hydroxypentyl (meth) acrylate, hydroxy-n-yl (meth) acrylate, hydroxy-propyl (meth) acrylate, hydroxy-yl (meth) acrylate, hydroxy-pentyl (meth) acrylate, hydroxy-yl (meth) acrylate, hydroxy-butyl (meth) acrylate, hydroxy-1-hydroxy-pentyl (meth) acrylate, hydroxy-butyl (meth) acrylate, hydroxy-butyl (meth) acrylate, hydroxy-butyl acrylate, 4-hydroxyhexyl (meth) acrylate, 4-hydroxyheptyl (meth) acrylate, 4-hydroxyoctyl (meth) acrylate, 2-chloro-2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 5-hydroxyhexyl (meth) acrylate, 5-hydroxyheptyl (meth) acrylate, 5-hydroxyoctyl (meth) acrylate, 5-hydroxynonyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 6-hydroxyheptyl (meth) acrylate, 6-hydroxyoctyl (meth) acrylate, 6-hydroxynonyl (meth) acrylate, 6-hydroxyheptyl (meth) acrylate, and the like, 6-hydroxydecyl (meth) acrylate, 7-hydroxyheptyl (meth) acrylate, 7-hydroxyoctyl (meth) acrylate, 7-hydroxynonyl (meth) acrylate, 7-hydroxydecyl (meth) acrylate, 7-hydroxyundecyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 8-hydroxynonyl (meth) acrylate, 8-hydroxydecyl (meth) acrylate, 8-hydroxyundecyl (meth) acrylate, 8-hydroxydodecyl (meth) acrylate, 9-hydroxynonyl (meth) acrylate, 9-hydroxydecyl (meth) acrylate, 9-hydroxyundecyl (meth) acrylate, 9-hydroxydodecyl (meth) acrylate, 9-hydroxytridecyl (meth) acrylate, hydroxy-substituted (9-substituted (meth) acrylate, hydroxy-substituted (meth) acrylate, or their salts, or their corresponding with (meth) acrylate, or their corresponding with (meth) acrylate, or their corresponding with (meth) acrylate, or their corresponding (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 10-hydroxyundecyl (meth) acrylate, 10-hydroxydodecyl (meth) acrylate, 10-hydroxytridecyl acrylate, 10-hydroxytetradecyl (meth) acrylate, 11-hydroxyundecyl (meth) acrylate, 11-hydroxydodecyl (meth) acrylate, 11-hydroxytridecyl (meth) acrylate, 11-hydroxytetradecyl (meth) acrylate, 11-hydroxypentadecyl (meth) acrylate, 12-hydroxydodecyl (meth) acrylate, 12-hydroxytridecyl (meth) acrylate, 12-hydroxytetradecyl (meth) acrylate, 13-hydroxypentadecyl (meth) acrylate, and the like, And alkyl (meth) acrylates having a hydroxyl group such as 13-hydroxytetradecyl (meth) acrylate, 13-hydroxypentadecyl (meth) acrylate, 14-hydroxytetradecyl (meth) acrylate, 14-hydroxypentadecyl (meth) acrylate, 15-hydroxypentadecyl (meth) acrylate, and 15-hydroxyheptadecyl (meth) acrylate.

Examples of the styrene monomer include: styrene; alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene and the like; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene, etc.; nitrostyrene; acetyl styrene; a methoxystyrene; and divinylbenzene.

Examples of the vinyl monomer include: vinyl esters of fatty acids such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; halogenated vinyl compounds such as vinyl chloride and vinyl bromide; vinylidene halides such as vinylidene chloride; nitrogen-containing heteroaromatic vinyl compounds such as vinylpyridine, vinylpyrrolidone and vinylcarbazole; conjugated dienes such as butadiene, isoprene and chloroprene; and unsaturated nitriles such as acrylonitrile and methacrylonitrile.

The compound having a structural unit represented by the formula (a) introduced therein can be synthesized, for example, by reacting a diisocyanate compound with a polyol.

The compound having a structural unit represented by the formula (b) introduced therein can be synthesized, for example, by reacting a halosilane or a silane having a hydroxyl group.

The compound having a structural unit represented by the introduction formula (c) can be synthesized, for example, by a reaction of a polycarboxylic acid with a polyhydric alcohol.

The structural unit selected from the structural units described in group a is preferably a structural unit derived from a (meth) acrylate. The structural unit derived from a (meth) acrylate is preferably an alkyl (meth) acrylate and an alkyl (meth) acrylate having a hydroxyl group.

The resin (a) of the present invention may further contain another structural unit (sometimes referred to as structural unit (aa)). Specifically, a structural unit derived from a (meth) acrylamide monomer, a structural unit derived from a monomer having a carboxyl group, a structural unit derived from a monomer having a heterocyclic group, a structural unit derived from a monomer having a substituted or unsubstituted amino group, and the like can be given.

Examples of the (meth) acrylamide monomer include: n-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N- (4-hydroxybutyl) (meth) acrylamide, N- (5-hydroxypentyl) (meth) acrylamide, N- (6-hydroxyhexyl) (meth) acrylamide, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N- (3-dimethylaminopropyl) (meth) acrylamide, N- (1, 1-dimethyl-3-oxobutyl) (meth) acrylamide, N- [2- (2-oxo-1-imidazolidinyl) ethyl ] (meth) acrylamide, N-hydroxyhexyl (meth) acrylamide, N-methyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N- (5-dimethylaminopropyl) (meth) acrylamide, N- (1, 1-dimethyl-3-oxobutyl) (meth) acrylamide, N- [2- (2-oxo-1-imidazolidinyl) ethyl ] (meth) acrylamide, N-hydroxyhexyl (meth) acrylamide, N-2-hydroxy-methyl) acrylamide, N-2-hydroxyethyl (meth) acrylamide, N-hydroxy-methyl) acrylamide, N- (4-methyl) acrylamide, N-methyl-acrylamide, N-2-hydroxy-methyl-acrylamide, N-ethyl (meth) acrylamide, N, or N, 2-acrylamido-2-methyl-1-propanesulfonic acid, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) (meth) acrylamide, N- (propoxymethyl) (meth) acrylamide, N- (1-methylethoxymethyl) (meth) acrylamide, N- (1-methylpropoxymethyl) (meth) acrylamide, N- (2-methylpropoxymethyl) (meth) acrylamide, N- (butoxymethyl) (meth) acrylamide, N- (1, 1-dimethylethoxymethyl) (meth) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N- (2-ethoxyethyl) (meth) acrylamide, N- (2-ethoxymethyl) acrylamide, N- (1-methylethoxymethyl) acrylamide, N- (2-ethoxymethyl) acrylamide, N- (2-propoxymethyl) acrylamide, N- (2-methylethoxymethyl) acrylamide, N- (1-propoxymethyl) acrylamide, N, n- (2-propoxyethyl) (meth) acrylamide, N- [2- (1-methylethoxy) ethyl ] (meth) acrylamide, N- [2- (1-methylpropoxy) ethyl ] (meth) acrylamide, N- [2- (2-methylpropoxy) ethyl ] (meth) acrylamide, N- (2-butoxyethyl) (meth) acrylamide, N- [2- (1, 1-dimethylethoxy) ethyl ] (meth) acrylamide and the like. Among them, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, and N- (2-methylpropoxymethyl) acrylamide are preferable.

Examples of the monomer having a carboxyl group include (meth) acrylic acid, carboxyalkyl (meth) acrylates (e.g., carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate), maleic acid, maleic anhydride, fumaric acid, crotonic acid, and the like, and acrylic acid is preferable.

Examples of the monomer having a heterocyclic group include acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3, 4-epoxycyclohexylmethyl (meth) acrylate, glycidyl (meth) acrylate, and 2, 5-dihydrofuran.

Examples of the monomer having a substituted or unsubstituted amino group include aminoethyl (meth) acrylate, N-dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, and the like.

The structural unit (aa) other than the structural unit having a merocyanine structure and the structural unit selected from group a is preferably a monomer having a carboxyl group.

The content of the structural unit having a merocyanine structure in a side chain is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and still more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of all the structural units contained in the resin (a).

The content of at least one structural unit selected from the structural units described in group a is preferably 50 parts by mass or more, and more preferably 60 to 99.99 parts by mass, relative to 100 parts by mass of all the structural units of the resin (a).

When the resin (a) contains the structural unit (aa), it is preferably 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, further preferably 0.5 parts by mass or more and 10 parts by mass or less, and particularly preferably 1 part by mass or more and 7 parts by mass or less, based on 100 parts by mass of the total structural units of the resin (a).

When the resin (a) contains a structural unit derived from an alkyl (meth) acrylate having a hydroxyl group, the content of the structural unit is preferably 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, further preferably 0.5 parts by mass or more and 10 parts by mass or less, and particularly preferably 1 part by mass or more and 7 parts by mass or less, relative to 100 parts by mass of the total structural units of the resin (a).

From the viewpoint of preventing an excessive peeling force of a release film that can be laminated on the outer surface of the pressure-sensitive adhesive layer, it is preferable that the release film substantially does not contain a monomer having an amino group. The term "substantially not included" means that the amount is 0.1 parts by mass or less per 100 parts by mass of all the constituent units constituting the resin (a).

From the viewpoint of reactivity between the resin (a) and the crosslinking agent (B) described later, the resin (a) preferably contains a structural unit derived from an alkyl (meth) acrylate having a hydroxyl group or a structural unit derived from a monomer having a carboxyl group, and more preferably contains any of a structural unit derived from an alkyl (meth) acrylate having a hydroxyl group and a structural unit derived from a monomer having a carboxyl group. As the alkyl (meth) acrylate having a hydroxyl group, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, and 6-hydroxyhexyl acrylate are preferable. In particular, good durability can be obtained by using 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate and 5-hydroxypentyl acrylate. As the monomer having a carboxyl group, acrylic acid is preferably used.

The weight average molecular weight (Mw) of the resin (a) is preferably 30 to 250 ten thousand, and more preferably 50 to 250 ten thousand. If the weight average molecular weight is 30 ten thousand or more, the durability of the pressure-sensitive adhesive layer in a high-temperature environment is improved, and problems such as peeling of the adherend from the light-selective absorbing pressure-sensitive adhesive layer, cohesive failure of the light-selective absorbing pressure-sensitive adhesive layer, and the like are easily suppressed. If the weight average molecular weight is 250 ten thousand or less, it is advantageous from the viewpoint of coatability when the adhesive composition is processed into, for example, a sheet form (applied to a substrate). From the viewpoint of satisfying both the durability of the light selective absorbing adhesive layer and the coatability of the adhesive composition, the weight average molecular weight is preferably 60 to 180 ten thousand, more preferably 70 to 170 ten thousand, and particularly preferably 100 to 160 ten thousand. The molecular weight distribution (Mw/Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually 2 to 10, preferably 3 to 8. The weight average molecular weight can be analyzed by gel permeation chromatography and is a value in terms of standard polystyrene.

When the resin (A) is dissolved in ethyl acetate to form a 20 mass% solution, the viscosity at 25 ℃ is preferably 20 pas or less, and more preferably 0.1 to 15 pas. The viscosity in this range is advantageous from the viewpoint of coatability when the adhesive composition is applied to a substrate. The viscosity can be measured by a brookfield viscometer.

The resin (a) of the present invention can be produced by a known method such as solution polymerization, bulk polymerization, suspension polymerization, or emulsion polymerization, and the solution polymerization is particularly preferred. Examples of the solution polymerization method include: mixing a monomer and an organic solvent, adding a thermal polymerization initiator under a nitrogen atmosphere, and stirring at 40 to 90 ℃, preferably 50 to 80 ℃ for about 3 to 15 hours. In order to control the reaction, a monomer or a thermal polymerization initiator may be continuously or intermittently added during the polymerization. The monomer and the thermal initiator may be added to an organic solvent.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, or the like can be used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone and the like. Examples of the thermal polymerization initiator include: azo compounds such as 2,2 ' -azobisisobutyronitrile, 2 ' -azobis (2-methylbutyronitrile), 1 ' -azobis (cyclohexane-1-carbonitrile), 2 ' -azobis (2, 4-dimethylvaleronitrile), 2 ' -azobis (2, 4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2 ' -azobis (2-methylpropionate), and 2,2 ' -azobis (2-hydroxymethylpropionitrile); organic peroxides such as lauryl peroxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, and (3,5, 5-trimethylhexanoyl) peroxide; and inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. In addition, a redox initiator using a combination of a peroxide and a reducing agent, or the like can be used.

The proportion of the polymerization initiator is about 0.001 to 5 parts by mass relative to 100 parts by mass of the total amount of the monomers constituting the resin (A). Polymerization methods based on active energy rays (e.g., ultraviolet rays) can be used for polymerization of the resin (a).

Examples of the organic solvent include: aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propanol and isopropanol; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

The resin (a) is preferably a resin satisfying the following formula (1), and more preferably a resin further satisfying the following formula (2).

ε(405)≥0.02 (1)

[ in the formula (1),. epsilon. (. 405) represents the molar absorption coefficient of the resin at a wavelength of 405 nm. The molar absorptivity was expressed in L/(g.cm). ]

ε(405)/ε(440)≥5 (2)

[ in the formula (2),. epsilon. (405) represents the molar absorption coefficient of the resin at a wavelength of 405nm, and. epsilon. (440) represents the molar absorption coefficient of the resin at a wavelength of 440 nm. ]

The molar absorbance coefficient of the resin (a) can be measured by the method described in examples.

The larger the value of ε (405) of resin (A), the more easily it absorbs light having a wavelength of 405nm, and the value of ε (405) is preferably 0.02L/(g cm) or more, more preferably 0.1L/(g cm) or more, still more preferably 0.2L/(g cm) or more, and usually 10L/(g cm) or less.

When the adhesive composition containing the resin (A) is applied to a display device (FPD: flat panel display) such as an organic electroluminescent display (organic EL display) or a liquid crystal display, if ε (405) of the resin (A) is 0.02L/(g cm) or more, the absorption performance of visible light in the vicinity of 400nm is good, and therefore, the deterioration of a retardation film or an organic EL light-emitting element used in a display device such as an organic EL display or a liquid crystal display due to visible light can be suppressed.

The larger the value of ε (405)/ε (440) of the resin (A), the more selectively light having a wavelength of about 400nm can be absorbed. The value of ε (405)/ε (440) is preferably 5 or more, more preferably 50 or more, still more preferably 75 or more, and particularly preferably 100 or more.

When the ε (405)/ε (440) of the resin (A) is 5 or more, when the adhesive composition containing the resin (A) is applied to a display device (FPD: flat panel display) such as an organic EL display device or a liquid crystal display device, light near 405nm is absorbed without inhibiting the color development of the display device, and the light degradation of a retardation film, an organic EL element, or the like can be suppressed.

(other Components contained in the adhesive composition)

The adhesive composition may further contain other resins than the crosslinking agent (B), the silane compound (D), the antistatic agent, the light selective absorber, the resin (a), and the like.

The content of the resin (a) is usually 60 to 99.99 mass%, preferably 70 to 99.9 mass%, and more preferably 80 to 99.7 mass% in 100 mass% of the solid content of the binder composition.

The adhesive composition may contain a crosslinking agent (B).

The crosslinking agent (B) includes an isocyanate crosslinking agent, an epoxy crosslinking agent, an aziridine crosslinking agent, a metal chelate crosslinking agent, and the like, and particularly, from the viewpoints of pot life of the adhesive composition, durability of the adhesive layer, crosslinking speed, and the like, an isocyanate crosslinking agent is preferable.

The isocyanate compound is preferably a compound having at least two isocyanate groups (-NCO) in a molecule, and examples thereof include: aliphatic isocyanate-based compounds (e.g., hexamethylene diisocyanate), alicyclic isocyanate-based compounds (e.g., isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), aromatic isocyanate-based compounds (e.g., toluene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.), and the like. The crosslinking agent (B) may be an adduct (adduct) of the isocyanate compound with a polyol compound [ for example, an adduct obtained by using glycerin, trimethylolpropane, or the like ], an isocyanurate compound, a biuret compound, a urethane prepolymer type isocyanate compound obtained by addition reaction with a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, or the like. The crosslinking agent (B) may be used alone or in combination of two or more. Among these, typical examples include: aromatic isocyanate compounds (e.g., toluene diisocyanate, xylylene diisocyanate), aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate), adducts thereof based on polyol compounds (e.g., glycerin, trimethylolpropane), or isocyanurates. This is probably because if the crosslinking agent (B) is an aromatic isocyanate-based compound and/or an adduct thereof based on a polyol compound or an isocyanurate compound, it is advantageous to form an optimum crosslinking density (or a crosslinked structure) and the durability of the adhesive layer can be improved. In particular, if the adhesive layer is a toluene diisocyanate-based compound and/or an adduct thereof based on a polyol compound, the durability can be improved even when the adhesive layer is applied to a polarizing plate or the like, for example.

The content of the crosslinking agent (B) is usually 0.01 to 15 parts by weight, preferably 0.05 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the resin (A).

The adhesive composition may further contain a silane compound (D).

Examples of the silane compound (D) include: vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylethoxydimethylsilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like.

The silane compound (D) may be a silicone oligomer. Specific examples of the silicone oligomer are as follows if they are expressed as a combination of monomers.

Mercaptopropyl-containing oligomers such as 3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, and 3-mercaptopropyltriethoxysilane-tetraethoxysilane oligomer; mercapto methyl group-containing oligomers such as mercapto methyltrimethoxysilane-tetramethoxysilane oligomer, mercapto methyltrimethoxysilane-tetraethoxysilane oligomer, mercapto methyltriethoxysilane-tetramethoxysilane oligomer, and mercapto methyltriethoxysilane-tetraethoxysilane oligomer; 3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetraethoxysilane copolymer, copolymers containing 3-glycidyloxypropyl group such as 3-glycidyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-glycidyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-glycidyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-glycidyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; 3-methacryloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropyltriethoxysilane-tetraethoxysilane oligomer, methacryloxypropyl-containing oligomers such as 3-methacryloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, and 3-methacryloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer; 3-acryloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-acryloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-acryloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloxypropyltriethoxysilane-tetraethoxysilane oligomer, acryloxypropyl-containing oligomers such as 3-acryloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-acryloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, and 3-acryloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer; vinyl group-containing oligomers such as vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinyltriethoxysilane-tetraethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, and vinylmethyldiethoxysilane-tetraethoxysilane oligomer; amino group-containing copolymers such as 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer.

The silane compound (D) may be a silane compound represented by the following formula (D1).

[ chemical formula 22]

(wherein A represents a C1-20 alkanediyl group or a C3-20 divalent alicyclic hydrocarbon group, -CH constituting the alkanediyl group and the alicyclic hydrocarbon group ₂ Optionally substituted by-O-or-CO-, R ⁴¹ Represents an alkyl group having 1 to 5 carbon atoms, R ⁴² 、R ⁴³ 、R ⁴⁴ 、R ⁴⁵ And R ⁴⁶ Each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. )

Examples of the alkanediyl group having 1 to 20 carbon atoms represented by A include a methylene group, a1, 2-ethanediyl group, a1, 3-propanediyl group, a1, 4-butanediyl group, a1, 5-pentanediyl group, a1, 6-hexanediyl group, a1, 7-heptanediyl group, a1, 8-octanediyl group, a1, 9-nonanediyl group, a1, 10-decanediyl group, a1, 12-dodecanediyl group, a1, 14-tetradecanediyl group, a1, 16-hexadecanediyl group, a1, 18-octadecanediyl group and a1, 20-eicosanediyl group. Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include a1, 3-cyclopentanediyl group and a1, 4-cyclohexanediyl group. as-CH constituting the alkanediyl and the alicyclic hydrocarbon group ₂ Examples of-groups substituted by-O-or-CO-include-CH ₂ CH ₂ -O-CH ₂ CH ₂ -、-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -、-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -、-CH ₂ CH ₂ -CO-O-CH ₂ CH ₂ -、-CH ₂ CH ₂ -O-CH ₂ CH ₂ -CO-O-CH ₂ CH ₂ -、-CH ₂ CH ₂ CH ₂ CH ₂ -O-CH ₂ CH ₂ -and CH ₂ CH ₂ CH ₂ CH ₂ -O-CH ₂ CH ₂ CH ₂ CH ₂ 。

As R ⁴¹ ～R ⁴⁵ Examples of the alkyl group having 1 to 5 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl and pentyl, and R is ⁴² ～R ⁴⁵ Examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a tert-butoxy group and a pentyloxy group.

Examples of the silane compound represented by the formula (d1) include: (trimethoxysilyl) methane, 1, 2-bis (trimethoxysilyl) ethane, 1, 2-bis (triethoxysilyl) ethane, 1, 3-bis (trimethoxysilyl) propane, 1, 3-bis (triethoxysilyl) propane, 1, 4-bis (trimethoxysilyl) butane, 1, 4-bis (triethoxysilyl) butane, 1, 5-bis (trimethoxysilyl) pentane, 1, 5-bis (triethoxysilyl) pentane, 1, 6-bis (trimethoxysilyl) hexane, 1, 6-bis (triethoxysilyl) hexane, 1, 6-bis (tripropoxysilyl) hexane, 1, 8-bis (trimethoxysilyl) octane, 1, 8-bis (triethoxysilyl) octane, Bis (tri-C1-5 alkoxysilyl) C1-10 alkanes such as 1, 8-bis (tripropoxysilyl) octane; bis (di-C1-5 alkoxy C1-5 alkylsilyl) C1-10 alkanes such as bis (dimethoxymethylsilyl) methane, 1, 2-bis (dimethoxymethylsilyl) ethane, 1, 2-bis (dimethoxyethylsilyl) ethane, 1, 4-bis (dimethoxymethylsilyl) butane, 1, 4-bis (dimethoxyethylsilyl) butane, 1, 6-bis (dimethoxymethylsilyl) hexane, 1, 6-bis (dimethoxyethylsilyl) hexane, 1, 8-bis (dimethoxymethylsilyl) octane and 1, 8-bis (dimethoxyethylsilyl) octane; and bis (mono-C1-5 alkoxy-di-C1-5 alkylsilyl) C1-10 alkanes such as 1, 6-bis (methoxydimethylsilyl) hexane and 1, 8-bis (methoxydimethylsilyl) octane. Among these, bis (tri C1-3 alkoxysilyl) C1-10 paraffins such as 1, 2-bis (trimethoxysilyl) ethane, 1, 3-bis (trimethoxysilyl) propane, 1, 4-bis (trimethoxysilyl) butane, 1, 5-bis (trimethoxysilyl) pentane, 1, 6-bis (trimethoxysilyl) hexane, and 1, 8-bis (trimethoxysilyl) octane are preferable, and 1, 6-bis (trimethoxysilyl) hexane and 1, 8-bis (trimethoxysilyl) octane are particularly preferable.

The content of the silane compound (D) is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, and still more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the resin (A).

The adhesive composition may further contain an antistatic agent.

Examples of the antistatic agent include a surfactant, a silicone compound, a conductive polymer, an ionic compound, and the like, and an ionic compound is preferable. The ionic compound may be a conventional compound. Examples of the cation component constituting the ionic compound include an organic cation and an inorganic cation. Examples of the organic cation include a pyridinium cation, a pyrrolidinium cation, a piperidinium cation, an imidazolium cation, an ammonium cation, a sulfonium cation, and a phosphonium cation. Examples of the inorganic cation include alkali metal cations such as lithium cation, potassium cation, sodium cation, and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation. In particular, from the viewpoint of compatibility with the (meth) acrylic resin, a pyridinium cation, an imidazolium cation, a pyrrolidinium cation, a lithium cation, and a potassium cation are preferable. The anionic component constituting the ionic compound may be any of inorganic anions and organic anions, and is preferably an anionic component containing a fluorine atom from the viewpoint of antistatic performance. Examples of the anion component containing a fluorine atom include hexafluorophosphate anion (PF) ₆ ^- ) Bis (trifluoromethanesulfonyl) imide anion [ (CF) ₃ SO ₂ ) ₂ N ^- ]Bis (fluorosulfonyl) imide anion [ (FSO) ₂ ) ₂ N ^- ]Tetrakis (pentafluorophenyl) borate anion [ (C) ₆ F ₅ ) ₄ B ^- ]And the like. These ionic compounds may be used alone or in combination of two or more. Particular preference is given to the bis (trifluoromethanesulfonyl) imide anion [ (CF) ₃ SO ₂ ) ₂ N ^- ]Bis (fluorosulfonyl) imide anion [ (FSO) ₂ ) ₂ N ^- ]Tetrakis (pentafluorophenyl) borate anion [ (C) ₆ F ₅ ) ₄ B ^- ]。

From the viewpoint of the stability with time of the antistatic performance of the light selective absorbing pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, an ionic compound which is solid at room temperature is preferable.

The content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 1 to 7 parts by mass, based on 100 parts by mass of the resin (a).

The adhesive composition contains a resin (a) as a light selective absorbing polymer, and may contain no light selective absorber or a light selective absorber. The adhesive composition preferably does not contain a light selective absorber. The light selective absorber selectively absorbs light of a specific wavelength, and preferably includes a compound having at least one absorption maximum at a wavelength of 360nm to 420nm, and more preferably includes a compound having an absorption maximum at 380nm to 410 nm. When the light selective absorber is contained, the content of the light selective absorber is preferably 0.5 parts by mass or less with respect to 100 parts by mass of the entire resin component. The content of the light selective absorber is preferably 0.5 parts by mass or less from the viewpoint of suppressing discoloration because there is a correlation between the content of the light selective absorber and the degree of discoloration at the end of the polarizing plate under high temperature and high humidity.

The light selective absorber is not particularly limited, and examples thereof include: organic light selective absorbers such as oxybenzone-based light selective absorbers, benzotriazole-based light selective absorbers, salicylate-based light selective absorbers, benzophenone-based light selective absorbers, cyanoacrylate-based light selective absorbers, triazine-based light selective absorbers, and the like. More specifically, examples thereof include: 5-chloro-2- (3, 5-di-sec-butyl-2-hydroxyphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxy benzophenone, 2, 4-benzyloxy benzophenone, and the like. These organic light selective absorbers may be used singly or in combination of two or more.

Examples of the light selective absorber include "Kemisorb 102" manufactured by Chemipro Kasei corporation, "Adecastab LA 46" manufactured by ADEKA corporation, "Adecastab LAF 70" manufactured by BASF Japan corporation, "Tinuvin 109", "Tinuvin 171", "Tinuvin 234", "Tinuvin 326", "Tinuvin 327", "Tinuvin 328", "Tinuvin 928", "Tinuvin 400", "Tinuvin 460", "Tinuvin 405", and Tinuvin 477 ". Examples of the benzotriazole-based light selective absorber include: "Adecasta LA 31" and "Adecasta LA 36" manufactured by ADEKA, Sumisorb 200 "," Sumisorb 250 "," Sumisorb 300 "," Sumisorb 340 "and" Sumisorb 350 "manufactured by Sumika Chemtex corporation," Kemisorb 74 "," Kemisorb 79 "and" Kemisorb 279 "manufactured by Chemipro Kasei corporation," TINUVIN99-2 "," TINUVIN 900 "and" TINUVIN 928 "manufactured by BASF corporation, and the like.

The light selective absorber may be an inorganic light selective absorber. Examples of the inorganic light selective absorber include titanium oxide, zinc oxide, indium oxide, tin oxide, talc, kaolin, calcium carbonate, titanium oxide-based composite oxide, zinc oxide-based composite oxide, ITO (tin-doped indium oxide), ATO (antimony-doped tin oxide), and the like. Examples of the titanium oxide-based composite oxide include zinc oxide doped with silica or alumina. These inorganic light selective absorbers may be used singly or in combination of two or more. The organic light selective absorber and the inorganic light selective absorber may be used in combination.

The pressure-sensitive adhesive composition may further contain one or more additives selected from the group consisting of solvents, crosslinking catalysts, tackifiers, plasticizers, softeners, pigments, rust inhibitors, inorganic fillers, light-scattering fine particles, and the like.

[ intermediate layer ]

The optical stack of the present invention comprises an interlayer 300. The intermediate layer 300 has only one or more layers selected from a liquid crystal cured layer, an alignment layer, and a lamination layer. The thickness of the intermediate layer 300 is not limited, but is, for example, 1 μm to 200 μm, preferably 5 μm to 200 μm.

From the viewpoint of suppressing occurrence of discoloration in the polarizing plate 10, the intermediate layer 300 preferably contains no light selective absorber, and in the case of containing a light selective absorber, the content per unit area of the light selective absorber is preferably 0.5g/m ² The following.

[ liquid Crystal cured layer ]

The optical laminate of the present invention may include a liquid crystal cured layer as an intermediate layer. The liquid crystal cured layer may be one layer or two or more layers. The optical laminate 101 shown in fig. 2 includes the first liquid crystal cured layer 30 and the second liquid crystal cured layer 31.

The liquid crystal cured layer is a layer of a cured product of a polymerizable liquid crystal compound, and is, for example, a retardation layer.

The retardation layer is a cured product of a polymerizable liquid crystal compound, and the retardation layer is exemplified by the first to fifth embodiments.

The first mode is as follows: phase difference layer in which rod-like liquid crystal compound is oriented in horizontal direction with respect to supporting substrate

A second form: retardation layer in which rod-like liquid crystalline compound is aligned in vertical direction with respect to supporting substrate

In the third state: phase difference layer in which rod-like liquid crystal compound changes orientation direction in a spiral manner in plane

The fourth mode: phase difference layer for tilt alignment of discotic liquid crystal compounds

The fifth mode: biaxial phase difference layer having discotic liquid crystal compound aligned in perpendicular direction to support substrate

For example, the first, second, and fifth embodiments are preferably used as an optical film for an organic electroluminescent display. Alternatively, these retardation layers can be used in a stacked manner.

The retardation layer 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 the retardation layer preferably satisfies the following formulas (7) and (8). 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 laminate of the present invention, when the retardation layer is in the first form and has reverse wavelength dispersibility, it is preferable that the retardation layer in the above formula (7) is more preferably 0.82. ltoreq. Re (450)/Re (550). ltoreq.0.93 because coloring in black display in a display device is reduced. Further preferably 120. ltoreq. Re (550). ltoreq.150.

Examples of the polymerizable liquid crystal compound used for forming the retardation 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 release (edited by the committee for liquid crystal release, issued by pillared corporation at 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. 2016-81035, international application laid-open No. 2017/043438, and japanese patent application laid-open No. 2011-207765.

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

The thickness of the retardation layer, which is a liquid crystal cured layer obtained by curing the polymerizable liquid crystal compound, is, for example, 0.1 to 10 μm, preferably 0.5 to 8 μm, and more preferably 1 to 6 μm.

The retardation layer may be a λ/4 retardation layer that gives a retardation of 1/4 wavelengths to transmitted light, a λ/2 retardation layer that gives a retardation of 1/2 wavelengths to transmitted light, a positive (japanese: ポジティブ) a plate, or a positive C plate. In the case where the first liquid crystal cured layer 30 and the second liquid crystal cured layer 31 are included as in the optical laminate 101 shown in fig. 2, examples of the combination of the first liquid crystal cured layer 30 and the second liquid crystal cured layer 31 include a combination of a λ/2 retardation layer and a λ/4 retardation layer, a combination of a λ/4 retardation layer and a positive C layer, and the like.

The optical laminate of the present invention may be configured as a circularly polarizing plate having a λ/4 retardation layer. The circularly polarizing plate can be used as a polarizing plate for antireflection.

[ alignment layer ]

The alignment layer has an alignment regulating force for aligning the liquid crystal compound contained in the liquid crystal cured layer formed on the alignment layer in a desired direction. Examples of the alignment layer include: an alignment polymer layer formed of an alignment polymer, a photo-alignment polymer layer formed of a photo-alignment polymer, and a trench alignment layer having a concave-convex pattern and a plurality of trenches (grooves) on the surface of the layer. The thickness of the alignment layer is usually 0.01 to 10 μm, preferably 0.01 to 5 μm.

The alignment polymer layer can be formed by applying a composition obtained by dissolving an alignment polymer in a solvent to a base material layer, removing the solvent, and optionally, polishing the composition. In this case, in the alignment polymer layer formed of the alignment polymer, the alignment regulating force can be arbitrarily adjusted depending on the surface state of the alignment polymer and the polishing conditions.

The photo-alignment polymer layer may be formed by applying a composition including a polymer or monomer having a photoreactive group and a solvent to a substrate layer and irradiating polarized light. In this case, the orientation regulating force in the photo-oriented polymer layer can be arbitrarily adjusted according to the polarized light irradiation condition or the like for the photo-oriented polymer.

The trench alignment layer can be formed, for example, by the following method: a method of forming a concave-convex pattern by performing exposure, development, and the like through an exposure mask having a slit with a pattern shape on a surface of a photosensitive polyimide film; a method of forming an uncured layer of an active energy ray-curable resin on a plate-like master having grooves on the surface thereof, transferring the layer to a base material layer, and curing the layer; and a method of forming an uncured layer of an active energy ray-curable resin on a base material layer, pressing a roll master having irregularities against the layer, etc., to form irregularities, and curing the irregularities.

The base layer is preferably a film formed of a resin material. As the resin material, for example, a resin material excellent in transparency, mechanical strength, thermal stability, stretchability, and the like can be used. Specific examples thereof include polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene polymers; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (meth) acrylic resins such as (meth) acrylic acid and polymethyl (meth) acrylate; cellulose ester resins such as cellulose triacetate, cellulose diacetate, and cellulose acetate propionate; vinyl alcohol resins such as polyvinyl alcohol and polyvinyl acetate; a polycarbonate-based resin; a polystyrene-based resin; a polyarylate-based resin; a polysulfone-based resin; a polyether sulfone-based resin; a polyamide resin; a polyimide resin; a polyether ketone resin; polyphenylene sulfide-based resin; polyphenylene ether resins, and mixtures and copolymers thereof. Among these resins, any of cyclic polyolefin resins, polyester resins, cellulose ester resins, and (meth) acrylic resins, or a mixture thereof is preferably used. The "(meth) acrylic acid" means "at least one of acrylic acid and methacrylic acid".

The base layer may be a single layer of one of the resins described above or a single layer obtained by mixing two or more of the resins described above, or may have a multilayer structure of two or more layers. In the case of having a multilayer structure, the resins forming the respective layers may be the same or different.

Any additive may be added to the resin material forming the resin film. Examples of the additives include a light selective absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an anti-coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent.

The thickness of the base material layer is not particularly limited, but is generally preferably 5 to 200 μm, more preferably 10 to 200 μm, and still more preferably 10 to 150 μm in view of workability such as strength and handling property.

In order to improve the adhesion between the base material layer and the alignment layer, at least the surface of the base material layer on the side where the alignment layer is to be formed may be subjected to corona treatment, plasma treatment, flame treatment, or the like, or an undercoat layer or the like may be formed. The substrate layer may be peeled off from the layer structure formed of the substrate layer/alignment layer/liquid crystal cured layer, and the alignment layer/liquid crystal cured layer may be used as a component of the intermediate layer of the present invention, or the substrate layer/alignment layer may be peeled off, and the liquid crystal cured layer may be used as a component of the intermediate layer of the present invention.

[ adhesive layer ]

The intermediate layer 300 may comprise a conformable layer for joining two layers. Examples of the adhesive layer include an adhesive layer and an adhesive layer (hereinafter, also referred to as "second adhesive layer"). The optical laminate 101 shown in fig. 2 includes: an adhesive layer 33 interposed between and joining the first liquid crystal cured layer 30 and the second liquid crystal cured layer 31, and a second adhesive layer 32 laminated on the surface of the first liquid crystal cured layer 30 opposite to the adhesive layer 33.

For the adhesive layer, an aqueous adhesive, an active energy ray-curable adhesive, a thermosetting adhesive, or the like can be used. The thickness of the adhesive layer is, for example, 10nm to 20 μm, preferably 100nm to 10 μm, and more preferably 500nm to 5 μm.

The second pressure-sensitive adhesive layer may be composed of a pressure-sensitive adhesive composition similar to the pressure-sensitive adhesive composition for forming the light-selective absorbing pressure-sensitive adhesive layer described above, or may be composed of a pressure-sensitive adhesive composition containing a resin such as a (meth) acrylic, rubber, urethane, ester, silicone, or polyvinyl ether resin as a main component (hereinafter, also referred to as "second pressure-sensitive adhesive composition"). The second adhesive composition is preferably an adhesive composition containing a (meth) acrylic resin having excellent transparency, weather resistance, heat resistance, and the like as a base polymer. The second adhesive composition may be an active energy ray-curable type or a thermosetting type. The thickness of the second pressure-sensitive adhesive layer is usually 0.1 μm or more and 150 μm or less, for example, 8 μm or more and 60 μm or less, and is preferably 30 μm or less, and more preferably 20 μm or less, from the viewpoint of thinning.

From the viewpoint of suppressing the occurrence of discoloration in the polarizing plate 10, the second adhesive layer preferably does not contain a light selective absorber, and in the case of containing a light selective absorber, the light selective absorber is preferably 0.5 parts by mass or less with respect to 100 parts by mass of the entire resin component per unit area.

< method for producing optical laminate >

The optical

layered bodies

100, 101, and 102 can be manufactured by a method including a step of bonding the constituent layers to each other via a bonding layer. Further, a step of peeling off a layer which does not constitute a layer may be included. In the case where the layers are bonded to each other via the bonding layer, in order to improve the adhesion, it is preferable to subject one or both surfaces of the bonding surface to a surface activation treatment such as corona treatment.

< optical laminate >

The optical laminate of the present invention is planar and has an area of, for example, 30mm × 30mm to 180mm × 90 mm.

The optical laminate of the present invention may have a rectangular shape such as a rectangle or a square, or may have a so-called irregular shape such as a shape in which a part of a side constituting the rectangle is cut out to have a cutout, a semicircular shape, or a shape having a through hole in a plane.

When the outer shape of the optical laminate has a straight side, the absorption axis of the polarizing plate constituting the optical laminate may be parallel to the side, may be orthogonal to the side, or may intersect obliquely at an angle of, for example, 45 °.

When the optical laminate has a retardation layer having a slow axis in the plane, the slow axis may intersect with the absorption axis of the polarizing plate constituting the optical laminate at 45 °, 15 °, or 75 °.

< image display device >

The optical

layered bodies

100, 101, and 102 are disposed on the front surface (visible side) of the image display panel, and can be used as components of the image display device. An optical laminate as a circularly polarizing plate can also be used as an antireflection polarizing plate to which an antireflection function is imparted in an image display device. The image display device is not particularly limited, and examples thereof include an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, and an electroluminescence display device.

Examples

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "parts" in examples and comparative examples are "% by mass" and "parts by mass".

[ production of Single-sided protective polarizing plate ]

(preparation of polarizing plate)

A polyvinyl alcohol film having a thickness of 20 μm, a polymerization degree of 2400, and a saponification degree of 99% or more was uniaxially stretched to a stretch ratio of 4.1 times on a heat roll, and immersed in a dyeing bath containing 0.05 parts by weight of iodine and 5 parts by weight of potassium iodide per 100 parts by weight of water at 28 ℃ for 60 seconds while maintaining the stretched state.

Next, the aqueous solution 1 of boric acid containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water was immersed at 64 ℃ for 110 seconds. Next, the resulting mixture was immersed in an aqueous boric acid solution 2 containing 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water at 67 ℃ for 30 seconds. Then, the resultant was washed with pure water at 10 ℃ and dried to obtain a polarizing plate. The obtained polarizing plate had a thickness of 8 μm and a boron content of 4.3 wt%.

(preparation of aqueous adhesive)

An aqueous adhesive was prepared by dissolving 3 parts by weight of a carboxyl-modified polyvinyl alcohol (trade name "KL-318" available from korea corporation) in 100 parts by weight of water, and adding 1.5 parts by weight of a polyamide epoxy additive (trade name "Sumirez Resin (registered trade name) 650(30), aqueous solution having a solid content concentration of 30% by weight, available from tianggang chemical industries, inc.) as a water-soluble epoxy Resin to the aqueous solution.

(protective film A and Release film B)

As the protective film A, a film (product name "COP 25 ST-HC" from Japan paper-making Co., Ltd.) was used in which a hard coat layer having a thickness of 3 μm was formed on a stretched film made of norbornene resin having a thickness of 25 μm.

As the release film B, a cellulose triacetate film (manufactured by Fuji film Co., Ltd. "TD 80 UL") was used. The thickness of the release film was 80 μm, and the moisture permeability was 502g/m ² ·24hr。

(preparation of Single-sided protective polarizing plate)

The produced polarizing plate was continuously transported while continuously unwinding the protective film a from a roll of the protective film a and the release film B from a roll of the release film B. A water-based adhesive was injected between the polarizing plate and the protective film a subjected to corona treatment, and pure water was injected between the polarizing plate and the release film B, and the laminate film composed of the protective film a/water-based adhesive/polarizing plate/pure water/release film B was obtained by passing through a bonding roll. The laminated film was conveyed and subjected to a heating treatment at 80 ℃ for 300 seconds in a drying oven, thereby drying the aqueous adhesive and volatilizing and removing pure water interposed between the polarizer and the release film B to obtain a single-sided protective polarizing plate with a release film. The release film B was peeled from the single-sided protective polarizing plate with the release film, to obtain a single-sided protective polarizing plate.

[ production of phase-difference laminate ]

("preparation of alignment layer/first cured liquid Crystal layer")

A lambda/4 phase difference layer (first cured liquid crystal layer) which is a layer obtained by curing a nematic liquid crystal compound and an alignment layer formed on a substrate film is prepared. The total thickness of the "alignment layer/first liquid crystal cured layer" was 2 μm.

(preparation of alignment layer/second liquid Crystal cured layer)

Polyethylene glycol di (meth) acrylate (A-600, manufactured by Ninghamu chemical industries Co., Ltd.) 10.0 parts by mass, trimethylolpropane triacrylate (A-TMPT, manufactured by Ninghamu chemical industries Co., Ltd.) 10.0 parts by mass, 1, 6-hexanediol di (meth) acrylate (A-HD-N, manufactured by Ninghamu chemical industries Co., Ltd.) 10.0 parts by mass, and Irgacure 907 (Irg-907, manufactured by BASF) 1.50 parts by mass, which is a photopolymerization initiator, were dissolved in methyl ethyl ketone 70.0 parts by mass as a solvent to prepare a coating liquid for forming an alignment layer.

As a base material film, a long cycloolefin resin (COP) film (manufactured by japan regen corporation) having a thickness of 20 μm was prepared, and an alignment layer forming coating liquid was applied to one surface of the base material film by a wire bar coater.

The coated layer was subjected to a heat treatment at 80 ℃ for 60 seconds and then heated at 220mJ/cm ² The composition for forming an alignment layer was polymerized and cured by irradiation with ultraviolet rays (UVB), thereby forming an alignment layer having a thickness of 2.3 μm on the base film.

20.0 parts by mass of a photopolymerizable nematic liquid crystal compound (RMM 28B, Merck) as a composition for forming a retardation layer and 1.0 part by mass of Irgacure 907 (Irg-907, BASF) as a photopolymerization initiator were dissolved in 80.0 parts by mass of propylene glycol monomethyl ether acetate as a solvent to prepare a coating liquid for forming a retardation layer.

The retardation layer-forming coating liquid was applied to the alignment layer obtained above, and the applied layer was subjected to a heat treatment at a temperature of 80 ℃ for 60 seconds. Then, at 220mJ/cm ² The composition for forming the retardation layer was polymerized and cured by irradiation with ultraviolet rays (UVB), thereby forming a retardation layer (second liquid crystal cured layer) having a thickness of 0.7 μm on the alignment layer. In this way, an "alignment layer/second liquid crystal cured layer" having a total thickness of 3 μm was obtained on the substrate film.

(production of retardation laminate)

The "alignment layer/first liquid crystal cured layer" laminated on the base film and the "alignment layer/second liquid crystal cured layer" laminated on the base film were laminated with an ultraviolet curable adhesive (thickness of 1 μm) so that the respective liquid crystal cured layer surfaces (surfaces on the opposite sides of the base film) became laminating surfaces. Next, the ultraviolet-curable adhesive was cured by irradiation with ultraviolet rays, and a phase difference laminate including two liquid crystal cured layers, i.e., a first liquid crystal cured layer and a second liquid crystal cured layer, was produced.

[ production of light-selective absorbing adhesive layer ]

< adhesive layer (1) >

(Synthesis of light-selective absorptive monomer)

A300 mL-four-necked flask equipped with a Dimrot condenser and a thermometer was placed under nitrogen, 10 parts of 2-hydroxyethyl acrylate, 8.1 parts of cyanoacetic acid, 1.1 parts of N, N-dimethyl-4-aminopyridine, 0.95 parts of dibutylhydroxytoluene, and 50 parts of toluene were added, and the mixture was stirred with a magnetic stirrer. After cooling in an ice bath and confirming that the internal temperature reached 10 ℃,12 parts of N, N-diisopropylcarbodiimide were added dropwise over 1 hour, and after completion of the dropwise addition, the mixture was further kept at an internal temperature of 0 to 10 ℃ for 2 hours. Then, insoluble matter was removed by filtration under reduced pressure to obtain 70 parts of a filtrate containing a compound represented by UVA-M-02.

[ chemical formula 23]

A300 mL-four-necked flask equipped with a Dimerosal condenser and a thermometer was placed in a nitrogen atmosphere, and 20 parts of a compound represented by UVA-M-01 synthesized in Japanese patent application laid-open No. 2014-194508, 7.1 parts of acetic anhydride, 70 parts of a filtrate containing UVA-M-02, and 40 parts of acetonitrile were charged and stirred with a magnetic stirrer. To the resulting mixture was added dropwise 9 parts of N, N-diisopropylethylamine at an internal temperature of 25 ℃ over 1 hour. The resulting mixture was kept at an internal temperature of 25 ℃ for 2 hours. To the resulting mixture was added 200g of ice water and stirred, and the precipitated crude product was removed by filtration under reduced pressure. The obtained crude product was recrystallized from isopropyl alcohol to obtain 10 parts of compound represented by UVA-01. By LC-MS and ¹ the compound represented by UVA-01 thus obtained was identified by H-NMR.

[ chemical formula 24]

(preparation of light-selective absorbing Polymer (A-1))

96 parts by mass of butyl acrylate (shown as "BA" in Table 1), 3 parts by mass of 2-hydroxyethyl acrylate (shown as "HEA" in Table 1), 1 part by mass of a photoselective absorptive monomer represented by UVA-01 (total of 100 parts by mass of solid matter), and 135 parts by mass of ethyl acetate as a solvent were mixed in a reaction vessel equipped with a condenser tube, a nitrogen inlet tube, a thermometer, and a stirrer, and the internal temperature was increased to 60 ℃ while oxygen was not contained in the reaction vessel by replacing the air in the apparatus with nitrogen. To the obtained mixture was added a solution obtained by dissolving 0.4 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate in the total amount. The resulting mixture was held at 60 ℃ for 1 hour, ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts/hr while keeping the internal temperature at 50 to 70 ℃, the addition of ethyl acetate was stopped when the concentration of the acrylic resin became 35%, and the internal temperature was maintained at 50 to 70 ℃ from the start of the addition of ethyl acetate to the elapse of 12 hours. To the obtained mixture of the light selective absorbing polymer (A-1), ethyl acetate was added to adjust the concentration of the resin component to 20% to prepare an ethyl acetate solution of the light selective absorbing polymer (A-1). The weight average molecular weight Mw of the light selective absorbing polymer (A-1) in terms of polystyrene based on GPC was 50 ten thousand, and Mw/Mn was 7.5. The glass transition temperature based on DSC was-48.4 ℃.

(preparation of adhesive composition and adhesive layer)

(a) Preparation of adhesive composition

To an ethyl acetate solution (resin concentration: 20%) of the photo-selective absorbent polymer (A-1), 0.5 parts of a crosslinking agent (CORONATE L, 75% of solid content: manufactured by Tosoh) and 0.5 parts of a silane compound (KBM-403, manufactured by shin-Etsu chemical industries, Ltd.) were mixed with respect to 100 parts of the solid content of the solution, and 2-butanone was further added so that the solid content concentration became 14%, to obtain an adhesive composition (1). The amount of the crosslinking agent (CORONATE L) is the mass part based on the active ingredient.

(b) Production of adhesive layer

The pressure-sensitive adhesive composition prepared in (a) above was applied to a release-treated surface of a polyethylene terephthalate film (SP-PLR 382050 manufactured by LINTEC, Inc., hereinafter simply referred to as "spacer") subjected to release treatment using an applicator so that the thickness of the pressure-sensitive adhesive layer after drying became 17 μm, and dried at 100 ℃ for 1 minute to prepare a pressure-sensitive adhesive layer. The obtained adhesive layer was used as an adhesive layer (1).

< adhesive layer (2) >, and

(preparation of acrylic resin (A-2))

A mixed solution of 61.9 parts of butyl acrylate, 1.9 parts of 2-hydroxyethyl acrylate, and 135 parts of ethyl acetate as a solvent was charged into a reaction vessel equipped with a condenser tube, a nitrogen inlet tube, a thermometer, and a stirrer, and the internal temperature was increased to 60 ℃ while oxygen was not contained in the atmosphere in the nitrogen substitution apparatus. Then, the entire amount of a solution prepared by dissolving 0.4 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. The resulting mixture was maintained at 60 ℃ for 1 hour, and ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts/hr while maintaining the internal temperature of 50 to 70 ℃, and the addition of ethyl acetate was stopped when the concentration of the acrylic resin reached 35%, and the temperature was maintained from the start of the addition of ethyl acetate to the elapse of 12 hours. . Finally, ethyl acetate was added to adjust the concentration of the acrylic resin to 20%, to prepare an ethyl acetate solution of the acrylic resin. The weight average molecular weight Mw of the obtained acrylic resin was 60 ten thousand in terms of polystyrene based on GPC, and Mw/Mn was 7.0. This was used as the acrylic resin (A-2). The glass transition temperature based on DSC was-52.9 ℃.

(preparation of adhesive composition and adhesive layer)

(a) Preparation of adhesive composition

An ethyl acetate solution (resin concentration: 20%) of an acrylic resin (A-2) was mixed with 0.5 parts of a crosslinking agent (CORONATE L, 75% of a solid content, manufactured by Tosoh), 0.5 parts of a silane compound (KBM-403, manufactured by shin-Etsu chemical industries, Ltd.), and 2.5 parts of a compound (photo-selective absorber) represented by the following formula (aa2) described as a photo-selective absorbing compound (2) in Synthesis example 2 described in paragraph [0142] of Japanese patent application laid-open No. 2019-007001, and 2-butanone was added so that the solid content concentration became 14%, to obtain an adhesive composition (2). The amount of the crosslinking agent (CORONATE L) is the mass part based on the active ingredient.

[ chemical formula 25]

(b) Production of adhesive layer

The adhesive layer (2) was prepared from the adhesive composition by the same method as the adhesive layer (1).

[ production of second adhesive layer ]

An ethyl acetate solution (resin concentration: 20%) of the acrylic resin (A-2) was mixed with 0.5 part of a crosslinking agent (CORONATE L, solid content 75%: manufactured by Tosoh) and 0.5 part of a silane compound (manufactured by shin-Etsu chemical industry: KBM-403), and 2-butanone was added so that the solid content concentration became 14%, to obtain an adhesive composition. The amount of the crosslinking agent (CORONATE L) is the mass part based on the active ingredient.

The adhesive composition was applied to the release-treated surface of the spacer for producing a light selective absorbing adhesive layer using an applicator so that the thickness of the dried adhesive layer became 5 μm, and the resultant was dried at 100 ℃ for 1 minute to produce a second adhesive layer.

[ production of optical laminate ]

(example 1, comparative example 1)

The second pressure-sensitive adhesive layer was bonded to the polarizer side of the produced single-sided protective polarizing plate, and the spacer was peeled off. The surface of the second pressure-sensitive adhesive layer from which the spacer was peeled was bonded to the surface exposed by peeling the substrate film on the first liquid crystal cured layer side from the produced retardation laminated body. Then, the base film on the second liquid crystal cured layer side was peeled off, and the pressure-sensitive adhesive layer described in table 1 was laminated as a light-selective absorbing pressure-sensitive adhesive layer on the surface of the alignment layer on the second liquid crystal cured layer side, to obtain an optical laminate composed of a layer of "protective film a/water-based adhesive/polarizing plate/second pressure-sensitive adhesive layer/alignment layer/first liquid crystal cured layer/second liquid crystal cured layer/alignment layer/light-selective absorbing pressure-sensitive adhesive layer/spacer". In this optical laminate, the intermediate layer had a layer composition of "second pressure-sensitive adhesive layer/alignment layer/first liquid crystal cured layer/ultraviolet-curable pressure-sensitive adhesive layer/second liquid crystal cured layer/alignment layer" and had a total thickness of 11 μm. The optical layered bodies of example 1 and comparative example 1 were configured as shown in fig. 2.

In the above operation, the second pressure-sensitive adhesive layer was prepared by applying the pressure-sensitive adhesive layer so that the thickness thereof became 5 μm using an applicator and drying the applied layer at 100 ℃ for 1 minute. The total thickness of the "alignment layer/first liquid crystal cured layer" was 2 μm. The total thickness of the "alignment layer/second liquid crystal cured layer" was 3 μm.

The thickness of the ultraviolet-curable adhesive was 1 μm.

(example 2, comparative example 2)

The second pressure-sensitive adhesive layer was bonded to the polarizer side of the produced single-sided protective polarizing plate, and the spacer was peeled off. The pressure-sensitive adhesive layer described in table 1 was bonded as a light-selective absorbing pressure-sensitive adhesive layer to the separator-peeled surface of the second pressure-sensitive adhesive layer, to obtain an optical laminate composed of a layer of "protective film a/water-based adhesive/polarizing plate/second pressure-sensitive adhesive layer/light-selective absorbing pressure-sensitive adhesive layer/separator". In this optical laminate, the intermediate layer was composed of the "second adhesive layer" and had a thickness of 5 μm. The optical layered bodies of example 2 and comparative example 2 were configured as shown in fig. 3.

In the above operation, the second pressure-sensitive adhesive layer was prepared by applying the pressure-sensitive adhesive layer so that the thickness thereof became 5 μm using an applicator and drying the applied layer at 100 ℃ for 1 minute.

[ measurement of Absorbance of adhesive layer ]

The pressure-sensitive adhesive layers (1) and (2) were bonded to glass, and after the spacers were peeled off, a cycloolefin polymer (COP) film (ZF-14, manufactured by giraffe corporation) was bonded to the pressure-sensitive adhesive layers to prepare a laminate for pressure-sensitive adhesive layer evaluation. The laminate for evaluation of pressure-sensitive adhesive layer was set in a spectrophotometer UV-2450 (Shimadzu corporation), and the absorbance was measured by the two-beam method at a wavelength range of 300 to 800nm in 1nm steps. The absorbance at a wavelength of 410nm of the pressure-sensitive adhesive layer thus prepared is shown in Table 1. The absorbance of the glass at a wavelength of 410nm and the absorbance of the COP film were both 0.

[ measurement of weight average molecular weight (Mw) ]

The weight average molecular weights (Mw) of the photo-selective absorbing polymer (A-1) and the acrylic resin (A-2) were determined by the following Size Exclusion Chromatography (SEC) using tetrahydrofuran as a mobile phase as a number average molecular weight (Mn) in terms of polystyrene. The (meth) acrylic polymer to be measured was dissolved in tetrahydrofuran at a concentration of about 0.05 mass%, and 10. mu.L was injected in SEC. The mobile phase was passed at a flow rate of 1.0 mL/min. As the column, PLGel MIXED-B (product of Polymer Laboratories) was used. The detector used was a UV-VIS detector (trade name: Agilent GPC).

[ measurement of boron content ]

0.2g of a polarizing plate was dissolved in 200g of a 1.9 wt% mannitol aqueous solution. The resulting aqueous solution was titrated with a 1mol/L NaOH aqueous solution, and the boron content of the polarizing plate was calculated by comparing the amount of NaOH solution required for neutralization with a calibration curve.

[ Damp and Heat resistance test and Observation of discoloration ]

The spacers of the optical laminates obtained in examples 1 and 2 and comparative examples 1 and 2 were peeled off and bonded to an alkali-free glass plate, and then left for 500 hours in an atmosphere of 65 ℃ and 90% RH. Next, a polarizing plate in a crossed nicol relationship was attached to the surface of the alkali-free glass opposite to the optical laminate, which was tested, and observed by an optical microscope, and an observation image was stored. The optical microscope used was "VHX-500" manufactured by Keyence. Fig. 4 shows an example of an observation image by an optical microscope. In fig. 4, when viewed from the end 50 of the optical laminate inward along a straight line indicated by an arrow (a straight line extending from the end 50 in a vertical direction), it is understood that a discolored region 51 and a region (non-discolored region) 52 in which no discoloration occurs exist.

[ measurement of the amount of discoloration based on image processing ]

The observation image with the microscope was converted into a black-and-white 256 scale (0 to 255) using image analysis software "ImageJ (free software)". The method of conversion to black-and-white 256 levels (0 to 255) uses an average method of RGB values. Fig. 5 shows an example of the converted data. The intermediate point (the middle of the decoloring shade) between the decoloring area 51 and the non-decoloring area 52 in the gradation curve in the vertical direction (arrow in fig. 4) with respect to the end 50 of the optical laminate was defined as the decoloring end of the optical laminate (fig. 5), and the distance (μm) from the end 50 of the optical laminate to the decoloring end was measured as the decoloring distance. The decoloring distance of the optical laminate is shown in table 1. The smaller the decoloring distance, the narrower the decoloring range, and the more excellent the moist heat resistance.

The decoloring distances of the optical laminates having the same layer structure (example 1 and comparative example 1, and example 2 and comparative example 2) were compared, and the difference and the improvement ratio of the decoloring distance ((absolute value of difference/decoloring distance of comparative examples 1 and 2) × 100) are shown in table 1.

[ Table 1]

Description of the reference numerals

10 polarizer, 11 protective film, 20 light selective absorbing adhesive layer, 30 first liquid crystal cured layer, 31 second liquid crystal cured layer, 32 second adhesive layer, 33 adhesive layer, 50 end of optical laminate, 51 decolored region, 52 non-decolored region, 100, 101, 102 optical laminate, 300 intermediate layer.

Claims

1. An optical stack comprising: a polarizing plate, a light selective absorbing adhesive layer, and an intermediate layer laminated in contact with the polarizing plate and the light selective absorbing adhesive layer,

the intermediate layer has only one or more layers selected from a liquid crystal cured layer, an alignment layer, and a lamination layer,

the polarizing plate is adsorbed with iodine, oriented with the iodine, and has a boron content of 5.0 mass% or less,

the adhesive composition forming the light selective absorbing adhesive layer includes a light selective absorbing polymer.

2. The optical laminate according to claim 1, further comprising a protective film laminated on a side of the polarizing plate opposite to the intermediate layer side.

3. The optical stack of claim 1 or 2,

＞N-C＝C-C＝C＜(1)

in formula (1), not all of the N atom and four C atoms constituting formula (1) constitute a part or all of the aromatic heterocyclic ring.

4. The optical stack of claim 3,

in the light selective absorbing polymer, the content of the structural unit having the structure represented by the chemical formula (1) is 0.01 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the total structural units.

5. The optical stack according to any one of claims 1 to 4,

6. The optical stack according to any one of claims 1 to 5,

7. The optical stack according to any one of claims 1 to 6,

8. The optical laminate according to any one of claims 1 to 7, which is a polarizing plate for antireflection.

9. An image display device comprising an image display panel, and the optical laminate according to claim 8 disposed on a front surface of the image display panel.

10. The image display device according to claim 9, which is an organic EL display device.