TWI865676B - Optical laminate and image display device - Google Patents

Abstract

This invention provides a novel optical laminate in which color loss at end portion of polarizer under high temperature and high humidity is suppressed.

An optical laminate according to this invention has a polarizer, a light-selective absorption pressure-sensitive adhesive layer, and an intermediate layer laminated between and in contact withthe polarizer and the light-selective absorption pressure-sensitive adhesive layer, wherein the intermediate layer only has a single layer or a plurality of layers selected from the group consisting of liquid crystal cured layer, oriented layer and bonding layer. The polarizer is adsorbed and oriented with iodine, and the content of boron in the polarizer is 5.0% by mass or less, and an adhesive composition forming the light-selective absorption pressure-sensitive adhesive layer includes a light-selective absorption polymer.

Description

Optical multilayer body and image display device

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

Polarizing plates formed by laminating protective films on one or both sides of polarizers are widely used in image display devices such as liquid crystal display devices and organic electroluminescent (organic EL) display devices, including mobile devices/televisions. In particular, in recent years, they have been widely used as optical components in various mobile devices such as mobile phones, smart phones, or tablet terminals.

Polarizing plates are often used by attaching them to image display elements (liquid crystal units and organic EL display elements, etc.) via an adhesive layer (pressure sensitive adhesive layer, also called pressure sensitive adhesive) (for example, Japanese Patent Publication No. 2010-229321 (Patent Document 1)). Therefore, polarizing plates are sometimes circulated in the market in the form of polarizing plates with adhesive layers pre-set on one side.

In addition, mobile devices are often used in harsh environments with high temperature and high humidity, and polarizers are required to be highly durable. Japanese Patent Publication No. 2013-105036 (Patent Document 2) states that by increasing the boric acid content in the polarizer to generate a large amount of boric acid crosslinks, the _I3 complex is highly oriented and exists with high stability, thereby suppressing the occurrence of blue light leakage and obtaining a polarizer with excellent low-temperature and high-humidity durability.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2010-229321

[Patent Document 2] Japanese Patent Publication No. 2013-105036

In polarizing plates, there is a problem that the ends of the polarizer are prone to discoloration in a high temperature and high humidity environment. This problem is particularly prominent in a structure where only a single surface of the polarizer is laminated with a protective film. Although it is known that there is a method to suppress the discoloration of the polarizer by increasing the boron content in the polarizer, if this method is used, there is a problem that it is easy to shrink due to heating.

The purpose of the present invention is to provide a novel optical laminate that suppresses discoloration (also known as fading) at the end of the polarizer under high temperature and high humidity.

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

[1] An optical laminate having a polarizer, a light selectively absorbing adhesive layer, and an intermediate layer laminated between the polarizer and the light selectively absorbing adhesive layer and in contact with the polarizer and the light selectively absorbing adhesive layer, wherein:

The aforementioned intermediate layer only has one or more layers selected from the group consisting of a liquid crystal curing layer, an orientation layer (also called an alignment layer), and a bonding layer.

The aforementioned polarizer has iodine adsorbed and oriented, and the boron content is less than 5.0 mass %.

The adhesive (pressure sensitive adhesive, also called pressure sensitive adhesive) composition forming the aforementioned light selective absorption adhesive layer includes a light selective absorption polymer.

[2] The optical multilayer body as described in [1] further has a protective film, which is laminated on the side of the polarizer opposite to the side of the intermediate layer.

[3] An optical laminate as described in [1] or [2], wherein the aforementioned light selectively absorbing polymer is a resin containing a structural unit having a structure shown by the following chemical formula (1) and having a glass transition temperature of less than 40°C:

>N-C=C-C=C< (1)

[However, not all of the 1 N atom and 4 C atoms constituting the chemical formula (1) constitute part or all of the aromatic heterocyclic ring].

[4] An optical laminate as described in [3], wherein the content of the structural unit having the structure shown by the above chemical formula (1) in the above light selective absorption polymer is 0.01 mass parts or more and 50 mass parts or less relative to 100 mass parts of all structural units.

[5] An optical multilayer as described in any one of claims [1] to [4], wherein the weight average molecular weight of the aforementioned light selective absorption polymer is greater than 300,000.

[6] An optical laminate as described in any one of [1] to [5], wherein the adhesive composition does not contain a light selective absorber, or the content of the light selective absorber is less than 0.5 parts by mass relative to 100 parts by mass of the total resin component.

[7] An optical multilayer as described in any one of [1] to [6], wherein the intermediate layer has a λ/4 phase difference layer belonging to the liquid crystal curing layer.

[8] An optical layered body as described in any one of [1] to [7], which is an anti-reflection polarizing plate.

[9] An image display device comprises an image display panel and the optical multilayer body described in [8] disposed on the front surface of the image display panel.

[10] The image display device as described in [9], which is an organic EL display device.

According to the present invention, an optical laminate that suppresses discoloration at the end of a polarizer in a high temperature and high humidity environment, and an image display device containing the optical laminate can be provided.

10: Polarizer

11: Protective film

20: Photoselective absorbent adhesive layer

30: First liquid crystal hardening layer

31: Second liquid crystal hardening layer

32: Second adhesive layer

33: Next is the agent layer

50: End of optical layer

51: Decolorized area

52: Non-decolorized area

100: Optical multilayers

101: Optical multilayers

102: Optical laminates

300: Middle layer

FIG1 is a schematic cross-sectional view showing an example of the optical multilayer body of the present invention.

FIG2 is a schematic cross-sectional view showing an example of the optical multilayer body of the present invention.

FIG3 is a schematic cross-sectional view showing an example of the optical multilayer body of the present invention.

Figure 4 is a diagram showing an example of an image observed with an optical microscope.

Figure 5 shows an example of converting an observed image into 256 grayscale data.

The following is an explanation of the implementation of the present invention with reference to the drawings, but the present invention is not limited to the following implementation. In all the following drawings, in order to make each component easy to understand, the scale is appropriately adjusted. The scale of each component shown in the drawings may not be consistent with the scale of the actual component.

<Optical layered structure>

The optical multilayer of the present invention has a polarizer, a light selective absorption adhesive layer, and an intermediate layer laminated between the polarizer and the light selective absorption adhesive layer and in contact with the polarizer and the light selective absorption adhesive layer. An example of the layer structure of the optical multilayer of the present invention is shown in Figures 1, 2, and 3.

FIG1 is a schematic cross-sectional view of an example of the optical multilayer of the present invention. The optical multilayer 100 shown in FIG1 sequentially has a protective film 11, a polarizer 10, an intermediate layer 300, and a light selective absorption adhesive layer 20 (hereinafter referred to as the "first adhesive layer"). The intermediate layer 300 has only one layer or a plurality of layers selected from the group consisting of a liquid crystal curing layer, an orientation layer, and a bonding layer.

FIG2 is a schematic cross-sectional view of an example of the optical multilayer of the present invention. The optical multilayer 101 shown in FIG2 has a protective film 11, a polarizer 10, an intermediate layer 300, and a light selective absorption adhesive layer 20 in sequence. The intermediate layer 300 has a second adhesive layer 32, a first liquid crystal curing layer 30, an adhesive layer 33, and a second liquid crystal curing layer 31 in sequence from the polarizer 10 side.

FIG3 is a schematic cross-sectional view of an example of the optical laminate of the present invention. The optical laminate 102 shown in FIG3 has a protective film 11, a polarizer 10, an intermediate layer 300, and a light selective absorption adhesive layer 20 in sequence. The intermediate layer 300 is composed of a second adhesive layer 32.

The thickness of the optical laminates 100, 101, and 102 varies depending on the functions and uses of the optical laminates, and is not particularly limited. For example, it may be between 5 μm and 200 μm, between 10 μm and 150 μm, or between 120 μm and 120 μm.

The light selectively absorbing adhesive layer includes a light selectively absorbing polymer. The optical laminate of the present invention has light selectively absorbing properties at least in the light selectively absorbing adhesive layer, thereby making the optical laminate as a whole also have light selectively absorbing properties. Light selectively absorbing properties refer to the property of easily absorbing light of a specific wavelength, and have at least one absorption maximum in the ultraviolet wavelength region to the visible light region. For example, when the light selectively absorbing adhesive layer has ultraviolet absorption ability, the optical laminate disposed on the image display element has the function of protecting the image display element from ultraviolet light.

The optical laminate of the present invention may also include a layer having light selective absorption performance in addition to the light selective absorption adhesive layer. Examples of other layers include the protective film 11 and the intermediate layer 300. In the present invention, the light selective absorption adhesive layer has light selective absorption performance and is a structure that helps to demonstrate the light selective absorption performance of the optical laminate as a whole, thereby improving the degree of freedom in designing the light selective absorption performance of other layers. For example, in order to improve the light selective absorption performance, the protective film 11 must be designed to be thicker, but because the degree of freedom in designing the light selective absorption performance is high, the protective film 11 can be easily thinned. For example, from the viewpoint of suppressing discoloration of the end of the polarizer under high temperature and high humidity, the intermediate layer 300 is preferably configured to contain substantially no light selective absorber, and even if it contains a light selective absorber, its content is preferably 0.5 g/m ² or less. When the intermediate layer 300 has a second adhesive layer, the second adhesive layer is also preferably configured to contain substantially no light selective absorber, and even if it contains a light selective absorber, its content is preferably 0.5 g/m ² or less.

The light selectively absorbing polymer in the light selectively absorbing adhesive layer has light selective absorbing properties and is a structure that helps the light selectively absorbing adhesive layer to exhibit its light selective absorbing properties. By doing so, the light selectively absorbing adhesive layer can be set to a structure that does not contain a light selective absorber, or a structure that reduces the content of the light selective absorber, thereby suppressing the discoloration of the end of the polarizer under high temperature and high humidity.

The inventors of this case have the following view: There is a correlation between the content of the light selective absorber contained in the adhesive layer and the degree of discoloration at the end of the polarizer under high temperature and high humidity. According to this view, it is generally believed that when a light selective absorber with a lower molecular weight is used, the light selective absorber in the adhesive layer will easily migrate to the side of the polarizer under high temperature and high humidity, and this migration is one of the important reasons for the discoloration. The inventors of this case conducted further active research and found that: when the adhesive layer is given light-selective absorption performance instead of adding a light-selective absorber, the light-selective absorption performance is given to the adhesive layer by making the adhesive layer contain a light-selective absorption polymer, the discoloration at the end of the polarizer under high temperature and high humidity can be suppressed, thus completing the present invention. It is believed that this is because the molecular weight of the light-selective absorption polymer is larger, so the migration to the polarizer is suppressed, and the discoloration at the end of the polarizer is suppressed.

[Polarizer]

The polarizer has the property of absorbing linear polarization with a vibration plane parallel to its absorption axis and allowing linear polarization with a vibration plane orthogonal to the absorption axis (parallel to the transmission axis) to pass through. The polarizer 10 of the optical layered body of the present invention is iodine adsorbed and oriented, and the boron content is less than 5.0 mass %.

By having a boron content of 5.0 mass % or less, preferably 4.5 mass % or less, shrinkage due to heating can be suppressed. The boron content is preferably 0.5 mass % or more, and more preferably 1 mass % or more. In the polarizer 10, the less the boron content, the less likely it is to produce discoloration at the end of the polarizer under high temperature and high humidity. It is believed that since the boron in the polarizer 10 increases the crosslinking degree of the polarizer 10, it helps to stably store iodine in the polarizer 10. Therefore, if the boron content is less, it becomes more difficult to stably store iodine, and it becomes easy to produce discoloration. In the present invention, as far as the polarizer 10 is concerned, even if the boron content is 5.0 mass % or less, discoloration under high temperature and high humidity can be suppressed.

The polarizer 10 can be exemplified by: a stretched film or stretched layer adsorbed with a dichroic pigment having absorption anisotropy, a hardened material containing a polymerizable liquid crystal compound and a liquid crystal hardened layer containing a dichroic pigment, etc. A dichroic pigment refers to a pigment having different properties in the absorbance in the long axis direction and the absorbance in the short axis direction of the molecule. As the pigment, iodine is suitable.

Polarizers are stretched films that adsorb anisotropically absorbing pigments, and are usually manufactured through the following steps: uniaxially stretching a polyvinyl alcohol resin film; dyeing the polyvinyl alcohol resin film with a dichroic pigment such as iodine to adsorb the dichroic pigment; treating the polyvinyl alcohol resin film adsorbing the dichroic pigment with a boric acid aqueous solution; and washing the film with water after the boric acid aqueous solution treatment.

The thickness of the polarizer is usually less than 30μm, preferably less than 15μm, more preferably less than 13μm, still more preferably less than 10μm, and particularly preferably less than 8μm. The thickness of the polarizer is usually more than 2μm, preferably more than 3μm, for example, more than 5μm.

Polyvinyl alcohol resins are obtained by saponifying polyvinyl acetate resins. As polyvinyl acetate resins, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers that can copolymerize with vinyl acetate can be used. Other monomers that can copolymerize with vinyl acetate include, for example, unsaturated carboxylic acid compounds, olefin compounds, vinyl ether compounds, unsaturated sulfonate compounds, and (meth)acrylamide compounds having an ammonium group.

The saponification degree of polyvinyl alcohol resin is usually between 85 mol% and 100 mol%, preferably between 98 mol% and above. Polyvinyl alcohol resin can be modified, and aldehyde-modified polyvinyl formaldehyde, polyvinyl acetal, etc. can also be used. The degree of polymerization of polyvinyl alcohol resin is usually between 1000 and 10000, preferably between 1500 and 5000.

The polarizer is a stretched layer adsorbed with a dye having anisotropic absorption, and can be generally manufactured by the following steps: a step of applying a coating liquid containing the above-mentioned polyvinyl alcohol resin on 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 laminated film with a dichroic dye such as iodine to adsorb the dichroic dye to make a polarizer; a step of treating the film adsorbed with the dichroic dye with an aqueous boric acid solution; and a step of washing with water after the treatment with the aqueous boric acid solution. The base film used to form the polarizer can also be used as a protective film 11. If necessary, the substrate film can be peeled off from the polarizer. The material and thickness of the substrate film can be the same as the material and thickness of the protective film 11 described later.

[Protective film]

The protective film 11 may be a coating layer or film made of an optically transparent thermoplastic resin, such as: cellulose acetate resins including cyclic polyolefin resins; cellulose triacetate, cellulose diacetate and other resins; polyester resins including polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate and other resins; polycarbonate resins; (meth) acrylic resins; polypropylene resins, including one or a mixture of two or more of these. The protective film 11 may contain the light selective absorber described below. In addition, the light selective absorber contained in the protective film 11 is not easily migrated to the polarizer because it is stored in the protective film 11.

A hard coating layer can be formed on the protective film 11. The hard coating layer can be formed on one side of the protective film 11 or on both sides. By providing the hard coating layer, the hardness and scratch resistance of the protective film 11 can be improved. The hard coating layer can be, for example, a hardening layer of acrylic resin, silicone resin, polyester resin, amine resin, amide resin, epoxy resin, etc. In order to improve the strength, the hard coating layer can also contain additives. The additives are not limited, and inorganic microparticles, organic microparticles, or a mixture thereof can be listed. The hard coating layer is, for example, a hardening layer of a UV-curing resin. UV-curable resins include acrylic resins, silicone resins, polyester resins, amine resins, amide resins, epoxy resins, etc.

The thickness of the protective film 11 is usually between 1 μm and 100 μm. From the perspective of strength and operability, it is preferably between 5 μm and 80 μm, more preferably between 8 μm and 60 μm, and even more preferably between 12 μm and 45 μm.

The resin film of the protective film 11 is, for example, bonded to the polarizer 10 via an adhesive layer. The adhesive forming the adhesive layer can be exemplified by: water-based adhesive, active energy ray-curable adhesive, or thermosetting adhesive, preferably water-based adhesive or active energy ray-curable adhesive. The two opposing surfaces bonded via the adhesive layer may be subjected to corona treatment, plasma treatment, flame treatment, etc. in advance, and may also have a primer layer, etc.

[Photoselective absorptive adhesive layer]

The light selectively absorbing adhesive layer 20 can be formed by dissolving or dispersing an adhesive composition containing a light selectively absorbing polymer in an organic solvent to make a dilute solution, applying the dilute solution on a substrate, and drying it. As a substrate, a plastic film is suitable, and specifically, a release film that has been subjected to a release treatment can be cited. The release film can be listed as follows: one side of a film composed of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarylate, etc., has been subjected to a polysilicone treatment or plasma treatment.

The thickness of the light selective absorption adhesive layer is, for example, 0.1 μm to 150 μm. When laminated with an image display panel, the thickness of the light selective absorption adhesive layer is usually 8 μm to 60 μm. From the perspective of thinning, it is preferably 30 μm or less, more preferably 25 μm or less, and particularly preferably 20 μm or less. When laminated with other optical films, such as a λ/4 phase difference layer, the thickness of the light selective absorption adhesive layer is usually 2 μm to 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, for example, 10 μm or more, but from the perspective of thinning, it is preferably 10 μm or less, and particularly preferably 7 μm or less.

The light selective absorption adhesive layer 20 preferably has an absorbance of 0.1 or more and 1.6 or less at a wavelength of 410 nm. This is because, by making the light selective absorption adhesive layer 20 have such an absorbance, the optical laminate as a whole will show the desired light selective absorption performance, and it is easy to form the optical laminate as a whole in a thin shape.

The absorbance of the photoselective absorbing adhesive layer at a wavelength of 390nm is usually below 5.0 and can be below 4.5.

The absorbance of the photoselective absorbing adhesive layer at a wavelength of 400nm is usually below 5.0 and can be below 4.5.

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

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

The absorbance of the light selective absorbing adhesive layer at a wavelength of 440nm is usually less than 0.10, preferably less than 0.05 and greater than 0.00. By making the absorbance at each wavelength within the above range, light in the ultraviolet region can be fully absorbed, while allowing light in the visible region to pass directly.

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

A(405)≧0.5 (3)

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

A(405)/A(440)≧5 (4)

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

The larger the value of A(405), the higher the absorption at a wavelength of 405nm. When the value of A(405) is less than 0.5, the absorption at a wavelength of 405nm is low, and components that are easily degraded by light near 400nm (such as display devices such as organic EL elements and liquid crystal phase difference films, etc.) will easily degrade. The value of A(405) is preferably 0.6 or more, more preferably 0.8 or more, and particularly preferably 1.0 or more. Although there is no special upper limit, it is usually 10 or less.

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

[Adhesive composition]

(Photoselective absorbing polymer)

The adhesive composition contains a photoselective absorbing polymer. The photoselective absorbing polymer is a polymer having photoselective absorbing properties. The photoselective absorbing polymer preferably absorbs light of a wavelength in the range of 360nm to 420nm. The photoselective absorbing polymer contains a photoselective absorbing structural unit having a portion having photoselective absorbing properties. The photoselective absorbing structural unit preferably has a portion having photoselective absorbing properties in the side chain. Examples of the portion having photoselective absorbing properties include a benzophenone group, a benzotriazole group, and the structure shown in the following chemical formula (1).

The light selective absorption polymer is preferably a resin (A) containing a structural unit having a structure shown in the following chemical formula (1) (hereinafter referred to as "Merocyanine structure") as a light selective absorption structural unit and having a glass transition temperature of 40°C or less.

>N-C=C-C=C< (1)

[However, not all of the 1 N atom and 4 C atoms constituting the chemical formula (1) constitute part or all of the aromatic heterocyclic ring].

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

The glass transition temperature (Tg) of the resin (A) is 40°C or less, preferably 20°C or less, more preferably 10°C or less, and even more preferably 0°C or less. In addition, the glass transition temperature of the resin (A) is usually -80°C or more, preferably -60°C or more, more preferably -50°C or more, even more preferably -45°C or more, and particularly preferably -30°C or more. If the glass transition temperature of the resin (A) is 40°C or less, it is beneficial to improve the adhesion of the light selective absorption adhesive layer formed by the adhesive composition containing the resin (A) to the adherend. In addition, if the glass transition temperature of the resin (A) is above -80°C, it is beneficial to improve the durability of the light selective absorption adhesive layer formed by the adhesive composition containing the resin (A) (appearance defects during high temperature tests: coagulation damage, etc.). In addition, the glass transition temperature can be measured by a differential scanning calorimeter (DSC).

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

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

ε(405)≧5 (1-a)

[In formula (1-a), ε(405) represents the gram absorptivity of a compound having a polymerizable group and a merocyanidin structure at a wavelength of 405 nm. The unit of gram absorptivity is L/(g‧cm). ]

ε(405)/ε(440)≧20 (2-a)

[In formula (2-a), ε(405) represents the gram absorption coefficient of the compound having a polymerizable group and a merocyanidin structure at a wavelength of 405nm, and ε(440) represents the gram absorption coefficient of the compound having a polymerizable group and a merocyanidin structure at a wavelength of 440nm. ]

For compounds with a polymerizable group and a merocyanidin structure, the value of ε(405) is preferably 5L/(g‧cm) or more, more preferably 10L/(g‧cm) or more, more preferably 20L/(g‧cm) or more, and more preferably 30L/(g‧cm) or more, and is usually 500L/(g‧cm) or less. Compounds with a larger value of ε(405) are more likely to absorb light at a wavelength of 405nm, and are more likely to exhibit the function of inhibiting degradation from ultraviolet rays or short-wavelength visible light.

The value of ε(405)/ε(440) of the compound having a polymerizable group and a merocyanidin structure is preferably 20 or more, more preferably 40 or more, even more preferably 70 or more, and particularly preferably 80 or more. A resin containing a compound having a large value of ε(405)/ε(440) will not hinder the color expression of a display device, and can suppress the light degradation of a display device such as a phase difference film and an organic EL element that absorb light near 405nm.

The structural unit having a partial anthocyanidin structure in the side chain can be exemplified by the structural unit derived from the compound represented by formula (I).

[In formula (I), R ¹ , R ² , R ³ , R ⁴ and R ⁵ independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 15 carbon atoms which may have a substituent, a heterocyclic group or an ethylenically unsaturated group. The -CH ₂ - contained in the aliphatic hydrocarbon group or the aromatic hydrocarbon group may be substituted by -NR ^1A -, -SO ₂ -, -CO-, -O- or S-.

^R6 and ^R7 independently represent 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.

^R1 and ^R2 may be linked to each other to form a ring structure, ^R2 and ^R3 may be linked to each other to form a ring structure, ^R2 and ^R4 may be linked to each other to form a ring structure, ^R3 and ^R6 may be linked to each other to form a ring structure, ^R5 and ^R7 may be linked to each other to form a ring structure, and ^R6 and ^R7 may be linked to each other to form a ring structure.

However, any one of ^R1 to ^R7 is an ethylenically unsaturated group]

The aliphatic alkyl group having 1 to 25 carbon atoms represented by ^R1 to ^R5 preferably includes methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-octyl, iso-octyl, n-nonyl, iso-nonyl, n-decyl, iso-decyl, n-dodecyl, iso-dodecyl, undecyl, lauryl, myristyl, cetyl, stearyl, etc.; cycloalkyl groups having 3 to 25 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.; cycloalkylalkyl groups having 4 to 25 carbon atoms such as cyclohexylmethyl, etc., and alkyl groups having 4 to 25 carbon atoms are preferred.

The substituents that the aliphatic hydrocarbon group having 1 to 25 carbon atoms represented by ^R1 to ^R5 may have include a hydroxyl group, a cyano group, a halogen atom, a hydroxyl group, an amino group, a nitro group, and the like.

Halogen atoms include fluorine, chlorine, bromine and iodine.

The aromatic hydrocarbon group having 6 to 15 carbon atoms represented by ^R1 to ^R5 includes aryl groups having 6 to 15 carbon atoms such as phenyl, naphthyl, anthracenyl, biphenyl, etc.; and aralkyl groups having 7 to 15 carbon atoms such as benzyl, phenylethyl, naphthylmethyl, phenyl, etc.

The substituents that the aromatic hydrocarbon group having 6 to 15 carbon atoms represented by ^R1 to ^R5 may have include: hydroxyl group, cyano group, halogen atom, alkyl group, amino group, nitro group, alkoxy group, alkylthio group, alkoxycarbonyl group, acyl group, acyloxy group, -C( ^NR2A ) ^R2B , -CONR3AR3B, _-SO2R4A ( ^{R2A , R2B} , ^R3A and ^{R3B each} independently represent a hydrogen atom or an alkyl group having 1 to ⁶ carbon atoms, and ^R4A is an alkyl group having 1 to 6 carbon atoms), etc.

Halogen atoms include: fluorine atom, chlorine atom, bromine atom, and iodine atom.

Alkoxy groups include: methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, undecyloxy, dodecyloxy and other alkoxy groups with 1 to 12 carbon atoms.

Examples of alkylthio groups include methylthio, ethylthio, propylthio, butylthio and other alkylthio groups with 1 to 12 carbon atoms.

Examples of acyl groups include acetyl, propionyl, butyryl and other acyl groups with 2 to 13 carbon atoms.

Examples of acyloxy groups include methylcarbonyloxy, ethylcarbonyloxy, n-propylcarbonyloxy, isopropylcarbonyloxy, n-butylcarbonyloxy, sec-butylcarbonyloxy, tert-butylcarbonyloxy, pentylcarbonyloxy, hexylcarbonyloxy, octylcarbonyloxy, and 2-ethylhexylcarbonyloxy, etc., acyloxy groups having 2 to 13 carbon atoms.

Alkoxycarbonyl groups include methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, butoxycarbonyl, pentyloxycarbonyl, hexyloxycarbonyl, octyloxycarbonyl, 2-ethylhexyloxycarbonyl, nonyloxycarbonyl, decyloxycarbonyl, undecyloxycarbonyl, dodecyloxycarbonyl and other alkoxycarbonyl groups with 2 to 13 carbon atoms.

Examples of -CONR ^3A R ^3B include aminocarbonyl, methylaminocarbonyl, dimethylaminocarbonyl, ethylaminocarbonyl, methylmethylaminocarbonyl and the like.

Examples of -C(NR ^2A )R ^2B include methylimino, dimethylimino, methylethylimino and the like.

Examples of -SO ₂ R ^4A include methylsulfonyl, ethylsulfonyl, and the like.

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ^1A and R ^1B include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, t-butyl and the like.

唑啉環基、噻唑啉環基、哌啶環基、嗎啉環基、哌

環基、吲哚環基、異吲哚環基、喹啉環基、噻吩環基、吡咯環基、噻唑啉環基以及呋喃環基等碳數4至20之脂肪族雜環基或碳數3至20之芳香族雜環基等。 Examples of the heterocyclic group represented by ^R1 to ^R5 include pyrrolidinyl ring group, pyrrolinyl ring group, imidazolidinyl ring group, imidazolinyl ring group,

Oxazoline ring group, thiazoline ring group, piperidine ring group, oxoline ring group, piperidine ring group

aliphatic heterocyclic groups having 4 to 20 carbon atoms or aromatic heterocyclic groups having 3 to 20 carbon atoms, such as cycloalkyl, indolecycloalkyl, isoindolecycloalkyl, quinolylcycloalkyl, thienylcycloalkyl, pyrrolecycloalkyl, thiazolinecycloalkyl and furanylcycloalkyl.

The alkyl group having 1 to 25 carbon atoms represented by ^R6 and ^R7 may include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, sec-butyl, n-pentyl, iso-pentyl, n-hexyl, iso-hexyl, n-octyl, iso-octyl, n-nonyl, iso-nonyl, n-decyl, iso-decyl, n-dodecyl, iso-dodecyl, undecyl, lauryl, myristyl, cetyl, stearyl and the like, which are straight chain or branched chain alkyl groups having 1 to 25 carbon atoms.

Examples of the electron withdrawing group represented by R ⁶ and R ⁷ include a cyano group, a nitro group, a halogen atom, an alkyl group substituted with a halogen atom, and a group represented by formula (I-1).

^* -X ¹ -R ¹¹¹ (I-1)

[In the formula, R ¹¹¹ represents a hydrogen atom or an alkyl group having 1 to 25 carbon atoms, and at least one of the methylene groups contained in the alkyl group may be substituted by an oxygen atom.

^X1 represents -CO-* ¹ , -COO-* ¹ , -CS-* ¹ , -CSS-* ¹ , ^-CSNR112- * ¹ , ^-CONR113- * ¹ , ^-CNR114- * ¹ or _SO2- * ¹ .

R ¹¹² , R ¹¹³ and R ¹¹⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or a phenyl group.

* ¹ indicates the bonding point with R ¹¹¹ .

* indicates where it is bonded to a carbon atom. ]

Halogen atoms include: fluorine atom, chlorine atom, bromine atom, and iodine atom.

Examples of alkyl groups substituted by halogen atoms include trifluoromethyl, perfluoroethyl, perfluoropropyl, perfluoroisopropyl, perfluorobutyl, perfluorosec-butyl, perfluorotert-butyl, perfluoropentyl, and perfluorohexyl. The number of carbon atoms in alkyl groups substituted by halogen atoms is usually 1 to 25.

Examples of the alkyl group having 1 to 25 carbon atoms represented by R ¹¹¹ include methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, sec-butyl, n-pentyl, iso-pentyl, n-hexyl, iso-hexyl, n-octyl, iso-octyl, n-nonyl, iso-nonyl, n-decyl, iso-decyl, n-dodecyl, iso-dodecyl, undecyl, lauryl, myristyl, cetyl, and stearyl. Straight or branched chain alkyl groups having 1 to 25 carbon atoms: cycloalkyl groups having 3 to 25 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; cycloalkylalkyl groups having 4 to 25 carbon atoms such as cyclopropylmethyl and cyclohexylmethyl; aryl groups having 6 to 25 carbon atoms such as phenyl, naphthyl, anthracenyl, and biphenyl; aralkyl groups having 7 to 25 carbon atoms such as benzyl, phenylethyl, naphthylmethyl, and phenyl.

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ¹¹² , R ¹¹³ and R ¹¹⁴ include the same examples as the alkyl group having 1 to 6 carbon atoms represented by R ^1A .

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

X ¹ is preferably -CO-* ¹ and COO-* ¹ .

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

唑啉環、噻唑啉環、哌啶環、嗎啉環、哌

環、吲哚環、異吲哚環等。R¹以及R²互相鍵結而形成之環可具有取代基，該取代基可列舉：甲基、乙基、丙基、丁基、異丁基等碳數1至12之烷基；甲氧基、乙氧基、丙氧基、丁氧基等碳數1至12之烷氧基等。 The ring structure formed by R ¹ and R ² bonding to each other is a nitrogen-containing ring structure containing a nitrogen atom bonding to R ¹ and R ² , and examples thereof include nitrogen-containing heterocyclic rings having 4 to 10 members. The ring structure formed by R ¹ and R ² bonding to each other may be a monocyclic ring or a polycyclic ring. Specifically, examples thereof include: a pyrrolidine ring, a pyrroline ring, an imidazoline ring, an imidazoline ring,

Azoline ring, thiazoline ring, piperidine ring, oxoline ring, piperidine ring

The ring formed by ^R1 and ^R2 bonding to each other may have a substituent, and the substituent may 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, butoxy, etc.

唑啉環、噻唑啉環、哌啶環、嗎啉環、哌

環、吲哚環、異吲哚環以及下述式(I-3)所表示之環結構。 The ring structure formed by ^R2 and ^R3 being bonded to each other is a nitrogen-containing ring structure containing a nitrogen atom bonded to ^R2 , and examples thereof include nitrogen-containing heterocyclic rings having 4 to 10 members. The ring structure formed by ^R2 and ^R3 being bonded to each other may be a monocyclic ring or a polycyclic ring. Specifically, examples thereof include: a pyrrolidine ring, a pyrroline ring, an imidazoline ring, an imidazoline ring,

Azoline ring, thiazoline ring, piperidine ring, oxoline ring, piperidine ring

ring, indole ring, isoindole ring and a ring structure represented by the following formula (I-3).

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

Ring ^W1 represents a ring having a nitrogen atom and X as constituent elements.]

Ring ^W1 is preferably a 5-membered or 6-membered ring having a nitrogen atom and X as constituent elements.

Specifically, the ring structure represented by formula (I-3) includes the following rings.

The ring structure formed by ^R2 and ^R3 being bonded to each other may have a substituent, and the substituent may be exemplified by: alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, butyl, isobutyl, etc.; and alkoxy groups having 1 to 12 carbon atoms, such as methoxy, ethoxy, propoxy, butoxy, etc.

The ring structure formed by R ² and R ³ bonding to each other is preferably a ring structure represented by the following formula (I-4).

[In formula (I-4), R ¹¹ represents the same meaning as above. m2 represents an integer from 1 to 7.

R ^11a , R ^11b , R ^11c and R ^11d each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

* indicates where it is bonded to a carbon atom. ]

m2 is preferably 2 or 3, and 2 is more preferred.

The ring structure formed by ^R2 and ^R4 bonding to each other can be a 4- to 10-membered nitrogen-containing ring structure, preferably a 5- to 9-membered nitrogen-containing ring structure. The ring structure formed by ^R2 and ^R4 bonding to each other can be a monocyclic ring or a polycyclic ring. These rings may have a substituent. Such ring structures can be exemplified by: pyrrole ring, indole ring, pyrimidine ring, and the rings described below.

The ring structure formed by ^R2 and ^R4 being bonded to each other may 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, butoxy, etc.; groups represented by ^{-NR22AR22B ,} such as amino, methylamino, dimethylamino ( ^R22A and ^R22B each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms); alkylthio groups having 1 to 12 carbon atoms, such as methylthio, ethylthio, propylthio, butylthio, pentylthio, etc.; heterocyclic groups having 4 to 9 carbon atoms, such as pyrrolidinyl, piperidinyl, oxolinyl, etc., and the like.

The ring structure formed by R ³ and R ⁶ being linked to each other is a ring structure of the skeleton of the ring formed by R ³ -C=CC=CR ^6. For example, phenyl and the like can be cited.

The ring structure formed by ^R5 and ^R7 being bonded to each other may include the following ring structures. The ring structure formed by ^R5 and ^R7 being bonded to each other may have a substituent, and the substituent may 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, butoxy, etc.

The ring structure formed by ^R6 and ^R7 being linked to each other can be exemplified by the ring structures described below. The ring structure formed by ^R6 and ^R7 being linked to each other can have a substituent ( _R1 to _R16 in the following formula), and the substituent can be exemplified by: 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, butoxy, etc.; and the ethylenically unsaturated groups described below.

[In the formula, * indicates the place where it is bonded to the carbon atom. ]

Examples of the ethylenically unsaturated group represented by ^R1 to ^R7 include vinyl, α-methylvinyl, acryl, methacryl, allyl, styryl and the group represented by formula (I-2).

*-R ¹¹⁵ -X ² (I-2)

[In formula (I-2), ^X2 represents a vinyl group, an acryl group or a methacryl group.

R ¹¹⁵ represents a divalent aliphatic hydrocarbon group having 1 to 18 carbon atoms, wherein -CH ₂ - contained in the aliphatic hydrocarbon group may be replaced by -O-, -CO-, -CS- or NR ¹¹⁶ -.

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

* indicates the place where it is bonded to a carbon atom or a nitrogen atom. ]

The divalent aliphatic alkyl group having 1 to 18 carbon atoms represented by R ¹¹⁵ includes alkanediyl groups having 1 to 18 carbon atoms such as methylene, ethylidene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl and 2-methylbutane-1,4-diyl; preferably, cycloalkanediyl groups having 3 to 18 carbon atoms such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl and cyclohexanediyl, and divalent aliphatic alkyl groups having 1 to 12 carbon atoms.

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ¹¹⁶ include the same examples as those of the alkyl group having 1 to 6 carbon atoms represented by R ^1A .

The ethylenically unsaturated groups represented by ^R1 to ^R7 are preferably independently vinyl, acryl, methacryl, and a group represented by formula (I-2).

Preferably, either R ⁶ or R ⁷ is an electron withdrawing group.

Preferably, either ^R6 or ^R7 is an ethylenically unsaturated group.

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

[In formula (II), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ independently represent a hydrogen atom, an aliphatic alkyl group having 1 to 25 carbon atoms which may have a substituent, an aromatic alkyl group having 6 to 15 carbon atoms or a heterocyclic group which may have a substituent, and the -CH ₂ - contained in the aliphatic alkyl group or the aromatic alkyl group may be substituted by NR ^11A -, -SO ₂ -, -CO-, -O- or S-.

R ¹⁶ and R ¹⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, an electron withdrawing group or an ethylenically unsaturated group.

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

R ¹² and R ¹³ may be linked to each other to form a ring structure, and R ¹² and R ¹⁴ may be linked to each other to form a ring structure.

However, either R ¹⁶ or R ¹⁷ is an ethylenically unsaturated group.]

Examples of the aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent and represented by ^R11 to ^R15 include the same examples as the aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent and represented by ^R1 .

The aromatic hydrocarbon group having 6 to 15 carbon atoms which may have a substituent and represented by ^R11 to ^R15 may be the same as the aromatic hydrocarbon group having 6 to 15 carbon atoms which may have a substituent and represented by ^R1 .

Examples of the heterocyclic ring represented by ^R11 to ^R15 include the same heterocyclic rings as those represented by ^R1 .

Examples of the alkyl group having 1 to 25 carbon atoms represented by ^R16 and ^R17 include the same examples as the alkyl group having 1 to 25 carbon atoms represented by ^R6 .

Examples of the electron withdrawing group represented by R ¹⁶ and R ¹⁷ include the same examples as the electron withdrawing group represented by R ⁶ .

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ^11A and R ^11B include the same examples as the alkyl group having 1 to 6 carbon atoms represented by R ^1A .

The ring structure that ^R12 and ^R13 may be linked to each other to form may be the same as the ring structure that ^R2 and ^R3 may be linked to each other to form. The ring structure that ^R12 and ^R13 may be linked to each other to form is preferably a monocyclic structure.

The ring structure that R ¹² and R ¹⁴ may be linked to form may be the same as the ring structure that R ² and R ⁴ may be linked to form. The ring structure that R ¹² and R ¹⁴ may be linked to form is preferably a monocyclic structure. The ring structure that R ¹² and R ¹⁴ may be linked to form is preferably an aromatic ring, and more preferably a pyrimidine ring structure.

R ¹¹ , R ¹³ and R ¹⁵ are each independently preferably an aliphatic alkyl group having 1 to 25 carbon atoms which may have a substituent, more preferably an alkyl group having 1 to 25 carbon atoms which may have a substituent, and even more preferably an alkyl group having 1 to 12 carbon atoms which may have a substituent.

In particular, R ¹¹ is preferably an aliphatic alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, and even more preferably a methyl group.

R ¹² and R ¹⁴ are each independently an aliphatic alkyl group having 1 to 25 carbon atoms which may have a substituent, but preferably R ¹² and R ¹⁴ are linked to each other to form a ring structure.

^R12 and ^R13 are preferably linked 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 formula (I-4), the ring structure represented by formula (I-4-1) or the ring structure represented by formula (I-4-2) is particularly preferred, and the ring structure represented by formula (I-4-1) is particularly preferred.

Preferably, either R ¹⁶ or R ¹⁷ is an ethylenically unsaturated group, and the other is an electron-withdrawing group.

The electron withdrawing group represented by R ¹⁶ and R ¹⁷ is preferably independently cyano, nitro, fluoro, trifluoromethyl, and a group represented by formula (I-1), and is particularly preferably cyano.

The ethylenically unsaturated groups represented by ^R16 and ^R17 are preferably independently vinyl, acryl, methacryl, and a group represented by formula (I- ₂ ). More preferably, they are *-CO-O-(CH2) ^nX2 [ ^X2 represents vinyl, acryl or methacryl, and n is an integer from 1 to 10 (preferably an integer from 2 to 6)].

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

[In formula (II-A-1), formula (II-A-2) and formula (II-B-1), R ¹¹ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ have the same meanings as described above.

R ^11e , R ^11f , R ^11g , R ^11h , R ^11k , R ^11m , and R ¹¹ⁿ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.

R ^11q and R ^11p each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a group represented by -NR ^22A R ^22B (R ^22A and R ^22B each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), or a heterocyclic ring.]

For example, a compound represented by 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 formula (L).

[In the formula, ^R222 represents a divalent linking group, and ^X2 represents a polymerizable group.]

The reaction of the compound represented by formula (I') and the compound represented by formula (L) can be carried out under any conditions generally used for Knoevenagel condensation. For example, it is preferably carried out in the presence of an alkali or a carboxylic anhydride. Examples of the alkali include triethylamine, N,N-diisopropylethylamine, pyridine, piperidine, pyrrolidine, proline, N,N-dimethylaminopyridine, imidazole, sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, potassium tert-butoxide, sodium tert-butoxide, and sodium hydroxide. Examples of the carboxylic anhydride include acetic anhydride, succinic anhydride, phthalic anhydride, maleic anhydride, and benzoic anhydride. The amount of the base used is preferably 0.1 to 10 moles per mole of the compound represented by formula (I'). The amount of acetic anhydride used is preferably 0.2 to 5 moles per mole of the compound represented by formula (I').

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

The reaction of the compound represented by formula (I') and the compound represented by formula (L) can be carried out by mixing the compound represented by formula (I') and the compound represented by formula (L).

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

The compound represented by formula (I') can be synthesized, for example, according to the method described in Japanese Patent Publication No. 2014-194508.

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

The preferred amount of cyanoacetate used is 0.5 to 3 moles relative to 1 mole of hydroxyalkyl acrylate.

The reaction of cyanoacetate with hydroxyalkyl acrylate can be carried out using any esterification catalyst used in a general esterification reaction, but is preferably carried out in the presence of a base and a carbodiimide condensation agent. Examples of the base include triethylamine, diisopropylethylamine, pyridine, piperidine, pyrrolidine, proline, N,N-dimethylaminopyridine, imidazole, sodium hydroxide, potassium hydroxide, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, potassium tert-butoxide, sodium tert-butoxide, sodium hydroxide, and the like. Examples of carbodiimide condensation agents include: N,N-dicyclohexylcarbodiimide, N,N-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, etc. The amount of base used is preferably 0.5 to 5 mol relative to 1 mol of cyanoacetate.

The reaction between cyanoacetate and hydroxyalkyl acrylate is preferably carried out in an organic solvent. Examples of organic solvents include acetonitrile, isopropanol, toluene, chloroform, dichloromethane, etc.

The reaction of cyanoacetate and hydroxyalkyl acrylate can be carried out by mixing cyanoacetate and hydroxyalkyl acrylate.

The reaction temperature of cyanoacetate and hydroxyalkyl acrylate is preferably between -40 and 130°C, and the reaction time is usually between 1 and 24 hours.

Compounds having a polymerizable group and anthocyanin structure include the following compounds.

The resin (A) may be a homopolymer of a structural unit having a part-anthocyanidin structure in the side chain, or a copolymer of a structural unit having a part-anthocyanidin structure in the side chain and other structural units. The resin (A) is preferably a copolymer.

In addition to the structural unit having an anthocyanin structure in the side chain, the structural unit that the resin (A) may contain may include, for example, the structural unit described in the following group A.

Group A: structural units derived from (meth)acrylate, structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, structural units represented by formula (a), structural units represented by formula (b), and structural units represented by formula (c)

[In the formula, R ^a1 represents a divalent alkyl group.

R ^b1 and R ^b2 each independently represent a hydrogen atom or a hydrocarbon group.

R ^c1 and R ^c2 each independently represent a divalent hydrocarbon group.]

Examples of (meth)acrylates include: linear alkyl (meth)acrylates 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; and linear alkyl (meth)acrylates such as isopropyl (meth)acrylate, isobutyl (meth)acrylate, tertiary butyl (meth)acrylate, isopentyl (meth)acrylate, isohexyl (meth)acrylate, and isopropyl (meth)acrylate. Branched alkyl esters of (meth)acrylic acid such as 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isostearyl (meth)acrylate, isopentyl (meth)acrylate, etc.; alkyl esters of (meth)acrylic acid containing aliphatic ring skeletons such as cyclohexyl (meth)acrylate, isoborneol (meth)acrylate, adamantyl (meth)acrylate, dicyclopentyl (meth)acrylate, cyclododecyl (meth)acrylate, methylcyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, α-ethoxycyclohexyl (meth)acrylate, etc.; esters of (meth)acrylic acid containing aromatic ring skeletons such as phenyl (meth)acrylate, etc.

The structural unit derived from (meth)acrylate can also be listed as follows: alkyl (meth)acrylate containing a substituent group in which a substituent group is introduced into the alkyl group in the alkyl (meth)acrylate. The substituent group of the alkyl (meth)acrylate containing a substituent group is a group that replaces the hydrogen atom of the alkyl group, and specific examples thereof include: phenyl, alkoxy, and phenoxy. Specific examples of the alkyl (meth)acrylate containing a substituent group include: 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-(2-phenoxyethoxy)ethyl (meth)acrylate, diethylene glycol phenoxy (meth)acrylate, poly(ethylene glycol) (meth)acrylate phenoxy, etc.

These (meth)acrylates can be used individually or in combination.

The resin (A) of the present invention preferably contains structural units of (meth)acrylic acid alkyl ester (a1) whose homopolymer has a glass transition temperature Tg of less than 0°C, and structural units of (meth)acrylic acid alkyl ester (a2) whose homopolymer has a Tg of 0°C or more. This is advantageous for improving the high temperature durability of the adhesive layer. The Tg of the homopolymer of (meth)acrylic acid alkyl ester can be, for example, the value of POLYMER HANDBOOK (Wiley-Interscience) and other literature.

Specific examples of the (meth)acrylic acid alkyl ester (a1) include: ethyl acrylate, n-propyl acrylate and isopropyl acrylate, n-butyl acrylate and isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate and isohexyl acrylate, n-heptyl acrylate, n-octyl acrylate and isooctyl acrylate, 2-ethylhexyl acrylate, n-nonyl acrylate and isononyl acrylate, n-decyl acrylate and isodecyl acrylate, n-dodecyl acrylate and other (meth)acrylic acid alkyl esters having an alkyl group with an alkyl group carbon number of about 2 to 12.

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, etc. are preferred from the viewpoint of tracking performance and reworkability when laminating optical films.

(Meth) alkyl ester (a2) is an alkyl (meth) acrylate other than (meth) alkyl ester (a1). Specific examples of (meth) alkyl ester (a2) include: methyl acrylate, cyclohexyl acrylate, isoborneol acrylate, stearyl acrylate, t-butyl acrylate, etc.

Alkyl (meth)acrylate (a2) may be used alone or in combination of two or more. From the perspective of high temperature durability, alkyl (meth)acrylate (a2) preferably contains methyl acrylate, cyclohexyl acrylate, isoborneol acrylate, etc., and more preferably contains methyl acrylate.

In addition, the structural unit derived from (meth)acrylate can include a structural unit derived from (meth)acrylate having a polar functional group.

Examples of (meth)acrylate monomers having polar functional groups 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, 4-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, 4- Hydroxyl hexyl ester, 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-hydroxydecyl (meth)acrylate, 7-hydroxyheptyl (meth)acrylate, 7-hydroxyoctyl (meth)acrylate, 7-hydroxynonyl (meth)acrylate, Ester, 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, 10-hydroxydecyl (meth)acrylate, 10-hydroxyundecyl (meth)acrylate, 10-hydroxydodecyl (meth)acrylate, 10-hydroxytridecyl acrylate, 10-hydroxytetradecyl (meth)acrylate, 11 -Hydroxy undecyl (meth)acrylate, 11-hydroxy dodecyl (meth)acrylate, 11-hydroxy tridecyl (meth)acrylate, 11-hydroxy tetradecyl (meth)acrylate, 11-hydroxy pentadecyl (meth)acrylate, 12-hydroxy dodecyl (meth)acrylate, 12-hydroxy tridecyl (meth)acrylate, 12-hydroxy tetradecyl (meth)acrylate, 13-hydroxy pentadecyl (meth)acrylate, 13-hydroxy tetradecyl (meth)acrylate, 13-hydroxy pentadecyl (meth)acrylate, 14-hydroxy tetradecyl (meth)acrylate, 14-hydroxy pentadecyl (meth)acrylate, 15-hydroxy pentadecyl (meth)acrylate, 15-hydroxy heptadecyl (meth)acrylate and other alkyl (meth)acrylates having a hydroxy group, etc.

Styrene monomers include styrene; alkyl styrenes such as methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, and octyl styrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; nitrostyrene; acetylstyrene; methoxystyrene; and divinylbenzene.

Vinyl monomers include: fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; halogenated vinyls such as vinyl chloride and vinyl bromide; halogenated vinyls such as vinylidene chloride; nitrogen-containing heteroaromatic vinyls such as vinyl pyridine, vinyl pyrrolidone, and vinyl carbazole; conjugated dienes such as butadiene, isoprene, and chloroprene; and unsaturated nitriles such as acrylonitrile and methacrylonitrile.

The compound derived from the structural unit represented by formula (a) can be synthesized, for example, by the reaction of a diisocyanate compound and a polyol.

The compound derived from the structural unit represented by formula (b) can be synthesized, for example, by the reaction of halogenated silane or silane having a hydroxyl group.

The compound derived from the structural unit represented by formula (c) can be synthesized, for example, by the reaction of polycarboxylic acid and polyol.

The structural unit selected from the structural units described in Group A is preferably a structural unit derived from (meth)acrylate. The structural unit derived from (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 other structural units (sometimes referred to as structural units (aa)). Specifically, they include: structural units derived from (meth)acrylamide monomers, structural units derived from monomers having carboxyl groups, structural units derived from monomers having heterocyclic groups, structural units derived from monomers having substituted or unsubstituted amino groups, etc.

(Meth)acrylamide monomers include: N-hydroxymethyl (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,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, Acrylamide, N-isopropyl (meth) acrylamide, N-(3-dimethylaminopropyl) (meth) acrylamide, N-(1,1-dimethyl-3-hydroxybutyl) (meth) acrylamide, N-[2-(2-hydroxy-1-imidazolidinyl)ethyl] (meth) acrylamide, 2-acrylamino-2-methyl-1-propanesulfonic acid, N-(methoxymethyl) acrylamide, N-(ethoxymethyl) (meth) acrylamide, N-(propoxy Methyl) (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 methyl)acrylamide, N-(2-propoxyethyl)(methyl)acrylamide, N-[2-(1-methylethoxy)ethyl](methyl)acrylamide, N-[2-(1-methylpropoxy)ethyl](methyl)acrylamide, N-[2-(2-methylpropoxy)ethyl](methyl)acrylamide, N-(2-butoxyethyl)(methyl)acrylamide, N-[2-(1,1-dimethylethoxy)ethyl](methyl)acrylamide, etc. Among them, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide and N-(2-methylpropoxymethyl)acrylamide are preferred.

Monomers with carboxyl groups include: (meth)acrylic acid, (meth)acrylic acid carboxylalkyl esters [such as (meth)acrylic acid carboxylethyl ester, (meth)acrylic acid carboxylpentyl ester], maleic acid, maleic anhydride, fumaric acid, crotonic acid, etc. Acrylic acid is preferred.

Monomers with heterocyclic groups include: acrylamide, vinyl caprolactam, N-vinyl-2-pyrrolidone, vinyl pyridine, tetrahydrofuran (meth)acrylate, tetrahydrofuran caprolactone-modified acrylate, 3,4-epoxyhexylmethyl (meth)acrylate, glycidyl (meth)acrylate, 2,5-dihydrofuran, etc.

Examples of monomers having substituted or unsubstituted amino groups include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, etc.

As the structural unit having the merocyanidin structure and the structural unit other than the structural unit selected from group A, a monomer having a carboxyl group is preferred.

Relative to 100 parts by weight of all structural units contained in the resin (A), the content of the structural unit having a partial anthocyanidin structure in the side chain is preferably 0.01 to 50 parts by weight, more preferably 0.1 to 20 parts by weight, and even more preferably 0.5 to 10 parts by weight.

Relative to 100 parts by weight of all structural units of 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 weight or more, and more preferably 60 to 99.99 parts by weight.

When the resin (A) contains the structural unit (aa), the structural unit (aa) is preferably 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, even more 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 all the 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, even more 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 all structural units of the resin (A).

From the perspective of preventing the separation film that can be deposited on the outside of the adhesive layer from increasing its peeling force, it is preferred that the monomer having an amine group is substantially not contained. Here, the term "substantially not contained" means that the monomer is less than 0.1 parts by mass in 100 parts by mass of all structural units constituting the resin (A).

In terms of the reactivity of the resin (A) and the crosslinking agent (B) described below, 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 both 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. The alkyl (meth)acrylate having a hydroxyl group is preferably 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, and 6-hydroxyhexyl acrylate. In particular, good durability can be obtained by using 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, and 5-hydroxypentyl acrylate. The monomer having a carboxyl group is preferably acrylic acid.

The weight average molecular weight (Mw) of the resin (A) is preferably 300,000 to 2.5 million, more preferably 500,000 to 2.5 million. If the weight average molecular weight is 300,000 or more, the durability of the adhesive layer in a high temperature environment will be improved, and it is easy to suppress the floating and peeling between the adherend and the light selective absorbing adhesive layer, and the coagulation and destruction of the light selective absorbing adhesive layer. If the weight average molecular weight is 2.5 million or less, it is advantageous from the perspective of coating when processing the adhesive composition into a sheet (coating on a substrate). From the perspective of both the durability of the photosensitive absorbent adhesive layer and the coating properties of the adhesive composition, the weight average molecular weight is preferably 600,000 to 1.8 million, more preferably 700,000 to 1.7 million, and particularly preferably 1 million to 1.6 million. In addition, the molecular weight distribution (Mw/Mn), which is 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 osmosis and is a value converted to standard polystyrene.

When the resin (A) is dissolved in ethyl acetate to form a solution with a concentration of 20 mass %, the viscosity at 25°C is preferably 20 Pa‧s or less, and more preferably 0.1 to 15 Pa‧s. If the viscosity is within this range, it is advantageous from the perspective of coating properties when the adhesive composition is coated on the substrate. In addition, the viscosity can be measured by a Brookfield viscometer.

The resin (A) of the present invention can be produced by known methods such as solution polymerization, block polymerization, suspension polymerization, emulsion polymerization, etc., and solution polymerization is particularly preferred. The solution polymerization method can be listed as follows: mixing monomers and organic solvents, adding thermal polymerization initiators in a nitrogen environment, stirring for about 3 to 15 hours at a temperature of 40 to 90°C, preferably about 50 to 80°C. In order to control the reaction, monomers or thermal polymerization initiators can be added continuously or intermittently during the polymerization. The monomer or thermal initiator can be in a state of being added to the organic solvent.

The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator. Examples of the photopolymerization initiator include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone. Thermal polymerization initiators include: 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-hydroxymethylpropionitrile) and other azo compounds; lauryl peroxide, tert-butyl hydrogen peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydrogen peroxide (cumene hydrogen peroxide), and 2,2'-azobis(2-methylpropionate). hydroperoxide), diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxytrimethylacetate, 3,5,5-trimethylhexyl peroxide, etc.; inorganic peroxides such as potassium persulfate, ammonium persulfate, hydrogen peroxide, etc. In addition, redox initiators that combine peroxides and reducing agents can also be used.

The ratio of the polymerization initiator to the total amount of 100 parts by mass of the monomers constituting the resin (A) is about 0.001 to 5 parts by mass. The polymerization of the resin (A) can be carried out by a polymerization method using active energy rays (such as ultraviolet rays, etc.).

Organic solvents 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, etc.

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

ε(405)≧0.02 (1)

[In formula (1), ε(405) represents the gram absorption coefficient of the resin at a wavelength of 405nm. The unit of gram absorption coefficient is L/(g‧cm). ]

ε(405)/ε(440)≧5 (2)

[In formula (2), ε(405) represents the gram absorption coefficient of the resin at a wavelength of 405nm, and ε(440) represents the gram absorption coefficient of the resin at a wavelength of 440nm. ]

In addition, the gram absorbance coefficient of the resin (A) can be measured by the method described in the embodiment.

The larger the ε(405) value of the resin (A), the easier it is to absorb light with a wavelength of 405nm. The ε(405) value is preferably 0.02L/(g‧cm) or more, more preferably 0.1L/(g‧cm) or more, and even more preferably 0.2L/(g‧cm) or more. It is usually 10L/(g‧cm) or less.

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

The greater the value of ε(405)/ε(440) of the resin (A), the more selectively it can absorb light with a wavelength near 400nm. The value of ε(405)/ε(440) is preferably 5 or more, more preferably 50 or more, even more preferably 75 or more, and particularly preferably 100 or more.

If 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, it will not hinder the color expression of the display device, and can absorb light near 405nm and suppress light degradation of the phase difference film or organic EL element.

(Other ingredients contained in the adhesive composition)

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

In the adhesive composition, the content of the resin (A) is usually 60% to 99.99% by mass, preferably 70% to 99.9% by mass, and more preferably 80% to 99.7% by mass, based on 100% by mass of the solid content.

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

The crosslinking agent (B) may include isocyanate crosslinking agents, epoxy crosslinking agents, aziridine crosslinking agents, metal chelate crosslinking agents, etc. In particular, from the perspective of the pot life of the adhesive composition, the durability of the adhesive layer, and the crosslinking speed, isocyanate crosslinking agents are preferred.

The isocyanate compound is preferably a compound having at least two isocyanate groups (-NCO) in the molecule, and examples thereof include: aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate, etc.), alicyclic isocyanate compounds (e.g., isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate), aromatic isocyanate compounds (e.g., tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.), and the like. In addition, the crosslinking agent (B) may be an adduct of a polyol compound derived from the aforementioned isocyanate compound [e.g., an adduct derived from glycerol, trihydroxymethylpropane, etc.]; and an isocyanate compound derivative of an amine prepolymer type obtained by addition reaction with trimerized isocyanate, a burette type compound, a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, etc. The crosslinking agent (B) may be used alone or in combination of two or more. Representative examples of such compounds include: adducts from aromatic isocyanate compounds (e.g., tolyl diisocyanate, xylyl diisocyanate), aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate), or such polyol compounds (e.g., glycerol, trihydroxymethyl propane), or trimerized isocyanates. If the crosslinking agent (B) is an aromatic isocyanate compound and/or such polyol compound, or an adduct from trimerized isocyanates, it is beneficial to form the most appropriate crosslinking density (or crosslinking structure), thereby improving the durability of the adhesive layer. In particular, if it is an adduct derived from a phenylene diisocyanate compound and/or such a polyol compound, the durability can be improved even when the adhesive layer is applied to a polarizing plate.

Relative to 100 parts by weight of the resin (A), 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.

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

Silane compounds (D) include, for example, vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tris(2-methoxyethoxy)silane, 3-glycidyloxypropyl trimethoxysilane, 3-glycidyloxypropyl triethoxysilane, 3-glycidyloxypropyl methyl dimethoxysilane, 3-glycidyloxypropyl ethoxy dimethyl silane, 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, 3-chloropropyl methyl dimethoxysilane, 3-chloropropyl trimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane, 3-butyl propyl trimethoxysilane, etc.

The silane compound (D) may be a polysiloxane oligomer. Specific examples of polysiloxane oligomers are as follows if indicated by the combination form of monomers.

3-Benzylpropyltrimethoxysilane-tetramethoxysilane oligomer, 3-Benzylpropyltrimethoxysilane-tetraethoxysilane oligomer, 3-Benzylpropyltriethoxysilane-tetramethoxysilane oligomer, 3-Benzylpropyltriethoxysilane-tetraethoxysilane oligomer and other oligomers containing benzoylpropyl; Benzylmethyltrimethoxysilane-tetramethoxysilane oligomer, Benzylmethyltrimethoxysilane-tetraethoxy Silane oligomer, Benzylmethyltriethoxysilane-tetramethoxysilane oligomer oligomers containing methyl groups such as triethoxysilane-tetraethoxysilane oligomers, trimethoxysilane-tetramethoxysilane copolymers, trimethoxysilane-tetraethoxysilane copolymers, triethoxysilane-tetramethoxysilane copolymers, triethoxysilane-tetraethoxysilane copolymers, trimethoxysilane-tetraethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropylmethyldimethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropyltrimethoxysilane-tetramethoxysilane copolymers, triethoxysilane-3-glycidyloxypropyltriethoxysilane-tetraethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropylmethyldimethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropyltrimethoxysilane-tetraethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropyltrimethoxysilane-tetraethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropyltrimethoxysilane-tetraethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropyltrimethoxysilane-tetraethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropylmethyldimethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropyltrimethoxysilane-tetramethoxysilane copolymers, trimethoxysilane-3-glycidyloxypropyltrimethoxysilane-tetraeth ... 3-Glycidyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-Glycidyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-Glycidyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer, etc.; 3-Methacryloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-Methacryloxypropyltrimethoxysilane -tetraethoxysilane oligomer, 3-methacryloxypropyl triethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropyl triethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropyl methyl dimethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropyl methyl dimethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropyl methyl diethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropyl 3-acryloxypropyl trimethoxysilane-tetramethoxysilane oligomer, 3-acryloxypropyl trimethoxysilane-tetraethoxysilane oligomer, 3-acryloxypropyl triethoxysilane-tetramethoxysilane oligomer, 3-acryloxypropyl triethoxysilane-tetramethoxysilane oligomer, 3-acryloxypropyl methyl dimethoxysilane -Tetramethoxysilane oligomer, 3-acryloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3-acryloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer, etc. oligomers containing acryloxypropyl groups; vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetraethoxysilane oligomer, etc. Oligomers containing vinyl groups such as methoxysilane oligomers, vinyl triethoxysilane-tetraethoxysilane oligomers, vinyl methyl dimethoxysilane-tetramethoxysilane oligomers, vinyl methyl dimethoxysilane-tetraethoxysilane oligomers, vinyl methyl diethoxysilane-tetramethoxysilane oligomers, and vinyl methyl diethoxysilane-tetraethoxysilane oligomers; 3-aminopropyl trimethoxysilane-tetramethoxysilane copolymers, 3-aminopropyl trimethoxysilane-tetraethoxysilane copolymers; Oxysilane copolymers, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymers, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymers, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymers, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymers, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymers, 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymers, and other copolymers containing amino groups.

The silane compound (D) may be a silane compound represented by the following formula (d1).

(In the formula, A represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic alkyl group having 3 to 20 carbon atoms, the _-CH2- constituting the alkanediyl group and the alicyclic alkyl group may be replaced by -O- or -CO-, ^R41 represents an alkyl group having 1 to 5 carbon atoms, and ^R42 , ^R43 , ^R44 , R45 and ^R46 independently represent 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 methylene, 1,2-ethanediyl, 1,3-propanediyl, 1,4-butanediyl, 1,5-pentanediyl, 1,6-hexanediyl, 1,7-heptanediyl, 1,8-octanediyl, 1,9-nonanediyl, 1,10-decanediyl, 1,12-dodecanediyl, 1,14-tetradecanediyl, 1,16-hexadecanediyl, 1,18-octadecanediyl, and 1,20-eicosanediyl. Examples of the divalent alicyclic alkyl group having 3 to 20 carbon atoms include 1,3-cyclopentanediyl and 1,4-cyclohexanediyl. Examples of the groups in which _-CH2 constituting the alkanediyl group and the _alicyclic hydrocarbon group is replaced by -O- or -CO- include -CH2CH2 _- O- _{CH2CH2- ,} -CH2CH2-O _{- CH2CH2} - _O -CH2CH2-, -CH2CH2-O _{- CH2CH2} -O _- CH2CH2- _, -CH2CH2- _{O - CH2CH2} -O-CH2CH2-, -CH2CH2-CO- _O - _{CH2CH2- , -CH2CH2} - _{O -} CH2CH2-CO-O-CH2CH2- _, -CH2CH2 _{- O - CH2CH2 - CO} - _{O - CH2CH2- , -CH2CH2CH2CH2 - O- CH2CH2- , and CH2CH2CH2CH2CH2 - O - CH2CH2CH2-} .

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

Examples of the silane compound represented by 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)butane, Bis(tri(C1-5)alkoxy)silyl)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, 1,8-bis(tripropoxysilyl)octane, etc. 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 Bis(di-C1-5 alkoxy-C1-5 alkylsilyl)C1-10 alkanes such as 1,8-bis(dimethoxymethylsilyl)octane and 1,8-bis(dimethoxyethylsilyl)octane; 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 them, bis(tri-C1-3 alkoxysilyl) C1-10 alkanes 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 preferred, and 1,6-bis(trimethoxysilyl)hexane and 1,8-bis(trimethoxysilyl)octane are particularly preferred.

Relative to 100 parts by mass of the resin (A), 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 even more preferably 0.1 to 1 part by mass.

The adhesive composition may further contain an antistatic agent.

Antistatic agents include surfactants, silicone compounds, conductive polymers, ionic compounds, etc., and ionic compounds are preferred. Ionic compounds include commonly used ones. Cationic components constituting ionic compounds include organic cations, inorganic cations, etc. Organic cations include, for example, pyridinium cations, pyrrolidinium cations, piperidinium cations, imidazolium cations, ammonium cations, cobalt cations, phosphonium cations, etc. Examples of inorganic cations include alkali metal cations such as lithium cations, potassium cations, sodium cations, and cesium cations; and alkaline earth metal cations such as magnesium cations and calcium cations. In particular, from the perspective of compatibility with (meth)acrylic resins, pyridinium cations, imidazolium cations, pyrrolidinium cations, lithium cations, and potassium cations are preferred. The anionic component constituting the ionic compound may be any of an inorganic anion and an organic anion, but in terms of antistatic performance, an anionic component containing fluorine atoms is preferred. Examples of anionic components containing fluorine atoms include hexafluorosulfonate 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-], etc. These ionic compounds may be used alone or in combination of two or more. In particular, bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N-], bis(fluorosulfonyl)imide anion [(FSO ₂ ) ₂ N-], and tetrakis(pentafluorophenyl)borate anion [(C ₆ F ₅ ) ₄ B-] are preferred.

In terms of the time-dependent stability of the antistatic properties of the light selective absorption adhesive layer formed by the adhesive composition, an ionic compound that is solid at room temperature is preferred.

Relative to 100 parts by mass of the resin (A), 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.

The adhesive composition contains a resin (A) which is a light selective absorbing polymer, and in addition thereto, may or may not contain 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 contains a compound having at least one absorption maximum at a wavelength of 360nm to 420nm, and more preferably contains a compound having an absorption maximum at 380nm to 410nm. When containing a light selective absorber, the content of the light selective absorber is preferably 0.5 parts by mass or less relative to 100 parts by mass of the total resin component. The content of the light selective absorber is related to the degree of discoloration at the end of the polarizer under high temperature and high humidity. Therefore, from the perspective of inhibiting discoloration, the content of the light selective absorber is preferably less than 0.5 parts by mass.

系光選擇吸收劑等有機系光選擇吸收劑。更具體而言，可列舉例如：5-氯-2-(3,5-二-第二丁基-2-羥基苯基)-2H-苯并三唑、(2-2H-苯并三唑-2-基)-6-(直鏈以及側鏈十二烷基)-4-甲基酚、2-羥基-4-苯甲基氧基二苯甲酮、2,4-苯甲基氧基二苯甲酮等。該等之有機系光選擇吸收劑可為1種或併用2種以上。 The light selective absorber is not particularly limited, and examples thereof include: oxybenzophenone-based light selective absorbers, benzotriazole-based light selective absorbers, salicylate-based light selective absorbers, benzophenone-based light selective absorbers, cyanoacrylate-based light selective absorbers, tris(2-hydroxy-2-nitropropene)-based light selective absorbers, and benzotriazole-based light selective absorbers.

Organic photoselective absorbers such as benzotriazole and benzotriazole. More specifically, examples thereof include 5-chloro-2-(3,5-di-sec-butyl-2-hydroxyphenyl)-2H-benzotriazole, (2-2H-benzotriazole-2-yl)-6-(linear and side chain dodecyl)-4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, and 2,4-benzyloxybenzophenone. Such organic photoselective absorbers may be used alone or in combination of two or more.

系光選擇吸收劑之CHEMIPRO KASEI股份有限公司製的「Kemisorb 102」，ADEKA股份有限公司製的「ADEKA stub LA46」、「ADEKA stub LAF70」，BASF japan公司製的「Tinuvin 109」、「Tinuvin 171」、「Tinuvin 234」、「Tinuvin 326」、「Tinuvin 327」、「Tinuvin 328」、「Tinuvin 928」、「Tinuvin 400」、「Tinuvin 460」、「Tinuvin 405」、「Tinuvin 477」等。苯并三唑系光選擇吸收劑可列舉ADEKA股份有限公司製的「ADEKA stub LA31」以及「ADEKA stub LA36」，住化Chemtex股份有限公司製的「Sumisorb 200」、「Sumisorb 250」、「Sumisorb 300」、「Sumisorb 340」以及「Sumisorb 350」，CHEMIPRO KASEI股份有限公司製的「Kemisorb 74」、「Kemisorb 79」以及「Kemisorb 279」，BASF公司製的「TINUVIN 99-2」、「TINUVIN 900」以及「TINUVIN928」等。 The light selective absorber can be a commercially available product, for example:

The photoselective absorbers include "Kemisorb 102" manufactured by CHEMIPRO KASEI Co., Ltd., "ADEKA stub LA46" and "ADEKA stub LAF70" manufactured by ADEKA Co., Ltd., and "Tinuvin 109", "Tinuvin 171", "Tinuvin 234", "Tinuvin 326", "Tinuvin 327", "Tinuvin 328", "Tinuvin 928", "Tinuvin 400", "Tinuvin 460", "Tinuvin 405", and "Tinuvin 477" manufactured by BASF Japan. Examples of benzotriazole-based light selective absorbers include "ADEKA stub LA31" and "ADEKA stub LA36" manufactured by ADEKA Co., Ltd., "Sumisorb 200", "Sumisorb 250", "Sumisorb 300", "Sumisorb 340" and "Sumisorb 350" manufactured by Sumika Chemtex Co., Ltd., "Kemisorb 74", "Kemisorb 79" and "Kemisorb 279" manufactured by CHEMIPRO KASEI Co., Ltd., and "TINUVIN 99-2", "TINUVIN 900" and "TINUVIN928" manufactured by BASF.

The light selective absorber may be an inorganic light selective absorber. Examples of inorganic light selective absorbers include titanium oxide, zinc oxide, indium oxide, tin oxide, talc, kaolin, calcium carbonate, titanium oxide composite oxides, zinc oxide composite oxides, ITO (tin doped indium oxide), ATO (antimony doped tin oxide), etc. Examples of titanium oxide composite oxides include titanium oxide doped with silicon dioxide and aluminum oxide, etc. Such inorganic light selective absorbers may be used alone or in combination of two or more. Organic light selective absorbers and inorganic light selective absorbers may also be used in combination.

The adhesive composition may contain one or more solvents, crosslinking catalysts, adhesives, plasticizers, softeners, pigments, rustproofing agents, inorganic fillers, light scattering microparticles and other additives.

[Middle layer]

The optical laminate of the present invention contains an intermediate layer 300. The intermediate layer 300 has only one layer or a plurality of layers selected from the group consisting of a liquid crystal curing layer, an orientation layer, and a bonding layer. The thickness of the intermediate layer 300 is not particularly limited, but is, for example, 1 μm to 200 μm, preferably 5 μm to 200 μm.

From the viewpoint of suppressing discoloration in the polarizer 10, the intermediate layer 300 preferably does not contain a light selective absorber. If it contains a light selective absorber, the content of the light selective absorber per unit area is preferably 0.5 g/ ^m2 or less.

[Liquid crystal hardening layer]

The optical multilayer of the present invention may contain a liquid crystal curing layer as an intermediate layer. The liquid crystal curing layer may be one layer or two layers or more. The optical multilayer 101 shown in FIG. 2 may contain a first liquid crystal curing layer 30 and a second liquid crystal curing layer 31.

The liquid crystal curing layer is a layer of a cured polymerizable liquid crystal compound, such as a phase difference layer.

The phase difference layer of the cured polymerizable liquid crystal compound can be listed in the first to fifth forms.

First form: The rod-shaped liquid crystal compound is a phase difference layer oriented in the horizontal direction relative to the supporting substrate

Second form: The rod-shaped liquid crystal compound is a phase difference layer oriented in the vertical direction relative to the supporting substrate

The third form: The rod-shaped liquid crystal compound is a phase difference layer that changes its orientation direction in a spiral shape within the plane

The fourth form: the phase difference layer of the discotic liquid crystal compound is tilted and oriented

Fifth form: The disc-shaped liquid crystal compound is a biaxial phase difference layer oriented in the vertical direction relative to the supporting substrate

For example, as an optical film used in an organic electroluminescent display, it is suitable to use the first form, the second form, and the fifth form. Or, a phase difference layer of these forms can be stacked.

The phase difference layer preferably has reverse wavelength dispersion. Reverse wavelength dispersion refers to the optical property that the phase difference value in the plane of the liquid crystal orientation at a short wavelength is smaller than the phase difference value in the plane of the liquid crystal orientation at a long wavelength. It is preferred that the phase difference layer satisfies the following equations (7) and (8). In addition, Re(λ) represents the in-plane phase difference value for light of wavelength λ nm.

Re(450)/Re(550)≦1 (7)

1≦Re(630)/Re(550) (8)

In the optical multilayer of the present invention, when the phase difference layer is in the first form and has reverse wavelength dispersion, the coloring during black display of the display device will be reduced, so it is better. In the above formula (7), if 0.82≦Re(450)/Re(550)≦0.93, it is better. If 120≦Re(550)≦150, it is even better.

The polymerizable liquid crystal compounds used for forming the phase difference layer include compounds having a polymerizable group among the compounds described in "3.8.6 Network (Completely Crosslinked Type)" and "6.5.1 Liquid Crystal Material b. Polymerizable Nematic Liquid Crystal Material" of Liquid Crystal Handbook (Edited by Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd. on October 30, 2001), and compounds described in Japanese Patent Application Laid-Open No. 2010-31223. The polymerizable liquid crystal compounds described in Japanese Patent Publication No. 2010-270108, Japanese Patent Publication No. 2011-6360, Japanese Patent Publication No. 2011-207765, Japanese Patent Publication No. 2011-162678, Japanese Patent Publication No. 2016-81035, International Publication No. 2017/043438, and Japanese Table No. 2011-207765, etc.

The method of manufacturing a phase difference layer from a layer composed of polymerized liquid crystal compounds in an oriented state can be exemplified by the method described in Japanese Patent Publication No. 2010-31223.

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

The phase difference layer can be a λ/4 phase difference layer that gives a phase difference of 1/4 wavelength to the transmitted light, a λ/2 phase difference layer that gives a phase difference of 1/2 wavelength to the transmitted light, a positive A plate, and a positive C plate. In the case where the optical multilayer 101 shown in FIG. 2 contains a first liquid crystal curing layer 30 and a second liquid crystal curing layer 31, as a combination of the first liquid crystal curing layer 30 and the second liquid crystal curing layer 31, a combination of a λ/2 phase difference layer and a λ/4 phase difference layer, a combination of a λ/4 phase difference layer and a positive C layer, etc. can be listed.

The optical multilayer of the present invention can be configured as a circular polarizing plate having a λ/4 phase difference layer. The circular polarizing plate can be used as an anti-reflection polarizing plate.

[Orientation layer]

The alignment layer has an alignment regulating force that makes the liquid crystal compound contained in the liquid crystal curing layer formed on the alignment layer orient the liquid crystal in the desired direction. The alignment layer can be listed as: an alignment polymer layer formed by an alignment polymer, a photoalignment polymer layer formed by a photoalignment polymer, and a groove alignment layer having a concave-convex pattern or a plurality of grooves (grooves) on the layer surface. The thickness of the alignment layer is usually 0.01 to 10μm, preferably 0.01 to 5μm.

The oriented polymer layer can be formed by dissolving the oriented polymer in a solvent to obtain a composition, applying the composition to a base layer, removing the solvent, and performing a rubbing treatment as needed. In this case, the oriented regulation force in the oriented polymer layer formed with the oriented polymer can be arbitrarily adjusted by the surface state of the oriented polymer and the rubbing conditions.

The photo-aligned polymer layer can be formed by applying a composition containing a polymer or monomer having a photoreactive group and a solvent to a base layer and irradiating the layer with polarized light. In this case, the directional regulation force in the photo-aligned polymer layer can be arbitrarily adjusted by adjusting the polarized light irradiation conditions for the photo-aligned polymer.

The groove orientation layer can be formed, for example, by the following methods: a method of forming a concave-convex pattern by exposing and developing the surface of a photosensitive polyimide film through an exposure mask having a narrow slit in the shape of a pattern; a method of forming an uncured layer of an active energy ray-curable resin on a plate-shaped original plate having grooves on the surface, transferring the layer to a base layer and curing it; a method of forming an uncured layer of an active energy ray-curable resin on a base layer, and pressing a roller-shaped original plate having concave-convex patterns against the layer, thereby forming concave-convex patterns and curing them, etc.

The substrate layer is preferably a film formed of a resin material. The resin material may be a resin material having excellent transparency, mechanical strength, thermal stability, elongation, etc. Specifically, there are: 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 acid resins such as (meth)acrylic acid and polymethyl (meth)acrylate; cellulose triacetate, cellulose diacetate and cellulose acetate acrylate. ester resins such as cellulose ester resins; vinyl alcohol resins such as polyvinyl alcohol and polyvinyl acetate; polycarbonate resins; polystyrene resins; polyarylate resins; polysulfide resins; polyethersulfide resins; polyamide resins; polyimide resins; polyetherketone resins; polyphenylene sulfide resins; polyphenylene ether resins, and mixtures and copolymers thereof. Among these resins, it is preferred to use any one of cyclic polyolefin resins, polyester resins, cellulose ester resins and (meth)acrylic resins or a mixture thereof. In addition, the above-mentioned "(meth)acrylic acid" refers to "at least one of acrylic acid and methacrylic acid".

The base layer may be a single layer in which one or more of the above-mentioned resins are mixed, or may be a multi-layer structure having two or more layers. In the case of a multi-layer structure, the resins constituting each layer may be the same or different.

Any additives may be added to the resin material that becomes the resin film. Examples of additives include: light selective absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents.

The thickness of the substrate layer is not particularly limited, but generally speaking, from the perspective of strength and operability, it is preferably 5 to 200 μm, more preferably 10 to 200 μm, and even more preferably 10 to 150 μm.

In order to improve the adhesion between the substrate layer and the orientation layer, at least the surface of the substrate layer on the side where the orientation layer is formed can be subjected to corona treatment, plasma treatment, flame treatment, etc., and a primer layer can also be formed. The substrate layer can also be peeled off from the layer structure including the substrate layer/orientation layer/liquid crystal curing layer, and the orientation layer/liquid crystal curing layer can be used as the constituent element of the intermediate layer of the present invention; the substrate layer/orientation layer can also be peeled off, and the liquid crystal curing layer can be used as the constituent element of the intermediate layer of the present invention.

[Lamination layer]

The middle layer 300 may contain a bonding layer for bonding two layers. The bonding layer may include a bonding agent layer, an adhesive layer (hereinafter also referred to as a "second adhesive layer"), etc. The optical laminate 101 shown in FIG. 2 contains a bonding agent layer 33 and a second adhesive layer 32; the bonding agent layer 33 is interposed between the first liquid crystal curing layer 30 and the second liquid crystal curing layer 31, and bonds the first liquid crystal curing layer 30 and the second liquid crystal curing layer 31; the second adhesive layer 32 is laminated on the surface of the first liquid crystal curing layer 30 on the opposite side to the bonding agent layer 33.

The adhesive layer can use a water-based adhesive, an active energy ray-curable adhesive, or a thermosetting adhesive. The thickness of the adhesive layer is, for example, greater than 10nm and less than 20μm, preferably greater than 100nm and less than 10μm, and more preferably greater than 500nm and less than 5μm.

The second adhesive layer may be composed of the same adhesive composition as the adhesive composition forming the above-mentioned light selective absorption adhesive layer, or may be composed of an adhesive composition having as a main component a resin such as (meth) acrylic acid, rubber, amine, ester, silicone, or polyvinyl ether (hereinafter, also referred to as "the second adhesive composition"). The second adhesive composition is preferably an adhesive composition using as a base polymer a (meth) acrylic resin having excellent transparency, weather resistance, heat resistance, etc. The second adhesive composition may be an active energy ray curing type or a heat curing type. The thickness of the second adhesive layer is usually between 0.1μm and 150μm, for example, between 8μm and 60μm. From the perspective of thinness, 30μm or less is preferred, and 20μm or less is more preferred.

From the perspective of suppressing discoloration of the polarizer 10, the second adhesive layer preferably does not contain a light selective absorber. When a light selective absorber is contained, the light selective absorber is preferably less than 0.5 parts by mass relative to 100 parts by mass of the total resin component per unit area.

<Method for manufacturing optical multilayer body>

The optical laminates 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. In addition, the method may include a step of peeling off a layer that is not a constituent layer. When bonding the layers to each other via a bonding layer, in order to improve adhesion, it is preferred to perform a surface activation treatment such as a corona treatment on one or both sides of the bonding surface.

<Optical layered structure>

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

The optical multilayer of the present invention can be a rectangle such as a rectangle or a square, or can be a shape with a notch cut in a part of the side constituting the rectangle, or a semicircular shape, or a shape with a through hole in the surface, etc., that is, a so-called irregular shape.

The absorption axis of the polarizer constituting the optical stack may be parallel to the edge, or orthogonal to the edge, or may cross the edge at an inclined angle (e.g., 45°) if the shape of the optical stack has a straight edge.

When the optical multilayer has a phase difference layer, and the phase difference layer has a slow axis in the plane, the slow axis and the absorption axis of the polarizer constituting the optical multilayer can cross at 45°, 15°, or 75°.

<Image display device>

The optical laminates 100, 101, and 102 can be arranged on the front surface (viewing side) of the image display panel and used as a constituent element of the image display device. The optical laminate, which is a circular polarizer, can also be used as an anti-reflection polarizer in the image display device to impart an anti-reflection function. The image display device is not particularly limited, and examples thereof include organic electroluminescent (organic EL) display devices, inorganic electroluminescent (inorganic EL) display devices, liquid crystal display devices, electroluminescent display devices, and other image display devices.

[Implementation example]

The following examples are given to illustrate the present invention in detail, but the present invention is not limited to these examples. "%" and "parts" in the examples and comparative examples are "mass %" and "mass parts" unless otherwise specified.

[Production of single-sided protected polarizing plate]

(Production of polarizing film)

A polyvinyl alcohol film with a thickness of 20 μm, a degree of polymerization of 2400, and a saponification degree of more than 99% was uniaxially stretched on a hot roller to a stretching ratio of 4.1 times, kept in a tight state, 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°C for 60 seconds.

Then, the polarizer was immersed in a boric acid aqueous solution 1 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 64°C for 110 seconds. Then, the polarizer was immersed in a boric acid aqueous 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°C for 30 seconds. After that, it was washed with pure water at 10°C and dried to obtain a polarizer. The thickness of the obtained polarizer was 8μm and the boron content was 4.3% by weight.

(Preparation of water-based adhesives)

Dissolve 3 parts by weight of carboxyl-modified polyvinyl alcohol (Kuraray Co., Ltd., trade name "KL-318") in 100 parts by weight of water, and add 1.5 parts by weight of polyamide epoxy additive (Taoka Chemical Co., Ltd., trade name "Sumirez resin (registered trademark) 650 (30), a 30% by weight aqueous solution of solid content concentration) which is a water-soluble epoxy resin to the aqueous solution to prepare a water-based adhesive.

(Protective film A and peeling film B)

As the protective film A, a film having a 3 μm thick hard coating layer formed on a 25 μm thick stretched film made of a norbornene-based resin (manufactured by Nippon Paper Industries, Ltd., trade name "COP25ST-HC") was used.

A cellulose triacetate film (manufactured by Fuji Film Co., Ltd., "TD80UL") was used as the peeling film B. The thickness of the peeling film was 80 μm, and the moisture permeability was 502 g/m ² ‧24 hr.

(Production of single-sided protected polarizing plate)

The produced polarizer is continuously transported, and the protective film A is continuously unwound from the reel of the protective film A, and the peeling film B is continuously rolled up from the reel of the peeling film B. A water-based adhesive is injected between the polarizer and the protective film A treated with corona, and pure water is injected between the polarizer and the peeling film B. Through the laminating roller, a laminated film consisting of protective film A/water-based adhesive/polarizer/pure water/peeling film B is obtained. The laminated film is transported and heated in a drying oven at 80°C for 300 seconds to dry the water-based adhesive and evaporate the pure water between the polarizer and the release film B to obtain a single-sided protective polarizing plate with a release film. The release film B is peeled off from the single-sided protective polarizing plate with a release film to obtain a single-sided protective polarizing plate.

[Production of phase difference multilayer]

(Preparation of "orientation layer/first liquid crystal curing layer")

A layer with a λ/4 phase difference (first liquid crystal cured layer) prepared to be formed on the substrate film and formed by curing the oriented layer and the nematic liquid crystal compound. In addition, the total thickness of the "oriented layer/first liquid crystal cured layer" is 2μm.

(Production of "orientation layer/second liquid crystal curing layer")

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

A 20 μm thick long strip of cyclic olefin resin (COP) film (manufactured by ZEON Co., Ltd., Japan) was prepared as a substrate film, and a coating liquid for forming an oriented layer was applied on one side of the substrate film using a bar coater.

The coated layer was heat treated at 80°C for 60 seconds and then irradiated with ultraviolet rays (UVB) of 220 mJ/cm ² to polymerize and cure the alignment layer forming composition, thereby forming an alignment layer with a thickness of 2.3 μm on the base film.

20.0 parts by mass of a photopolymerizable nematic liquid crystal compound (RMM28B manufactured by Merck) as a composition for forming a phase difference layer and 1.0 parts by mass of Irgacure 907 (Irg-907 manufactured by BASF) as a photopolymerization initiator were dissolved in 80.0 parts by mass of a solvent, propylene glycol monomethyl ether acetate, to prepare a coating liquid for forming a phase difference layer.

A coating liquid for forming a phase difference layer is applied on the previously obtained alignment layer, and the coating layer is heat treated at a temperature of 80°C for 60 seconds. Thereafter, ultraviolet rays (UVB) of 220mJ/ ^cm2 are irradiated to polymerize and cure the phase difference layer forming composition, thereby forming a phase difference layer (second liquid crystal cured layer) with a thickness of 0.7μm on the alignment layer. In this way, a "alignment layer/second liquid crystal cured layer" with a thickness of 3μm consisting of an alignment layer and a phase difference layer is obtained on the substrate film.

(Production of phase difference multilayer)

The "orientation layer/first liquid crystal curing layer" laminated on the substrate film and the "orientation layer/second liquid crystal curing layer" laminated on the substrate film are laminated by using a UV curable adhesive (thickness 1μm) so that the respective liquid crystal curing layer surfaces (surfaces on the opposite side to the substrate film) become the laminating surfaces. Then, UV rays are irradiated to cure the UV curable adhesive, and a phase difference laminate including two liquid crystal curing layers, the first liquid crystal curing layer and the second liquid crystal curing layer, is produced.

[Preparation of photoselective absorptive adhesive layer]

<Adhesive layer (1)>

(Synthesis of photoselective absorbing monomers)

A 300mL four-necked flask equipped with a Dimroth condenser and a thermometer was set to a nitrogen atmosphere, and 10 parts of 2-hydroxyethyl acrylate, 8.1 parts of cyanoacetate, 1.1 parts of N,N-dimethyl-4-aminopyridine, 0.95 parts of dibutylhydroxytoluene, and 50 parts of toluene were added, and stirred with a magnetic stirrer. After cooling with an ice bath, after confirming that the internal temperature reached 10°C, 12 parts of N,N-diisopropylcarbodiimide were added dropwise over 1 hour, and after the addition was completed, the internal temperature was kept at 0 to 10°C for another 2 hours. Afterwards, the insoluble components were removed by reduced pressure filtration to obtain 70 parts of the filtrate containing the compound represented by UVA-M-02.

A 300mL four-necked flask equipped with a Dai cooling tube and a thermometer was set to a nitrogen atmosphere, and 20 parts of the compound represented by UVA-M-01 synthesized with reference to Japanese Patent Publication No. 2014-194508, 7.1 parts of acetic anhydride, 70 parts of the filtrate containing UVA-M-02, and 40 parts of acetonitrile were added, and stirred with a magnetic stirrer. At an internal temperature of 25°C, 9 parts of N,N-diisopropylethylamine were added dropwise to the obtained mixture over a period of 1 hour. The obtained mixture was kept at an internal temperature of 25°C for 2 hours. 200g of ice water was added to the obtained mixture and stirred, and the precipitated crude product was removed by reduced pressure filtration. The obtained crude product was recrystallized with isopropanol to obtain 10 parts of the compound represented by UVA-01. The obtained compound represented by UVA-01 was identified by LC-MS and ¹ H-NMR.

(Preparation of light selective absorption polymer (A-1))

In a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer, 96 parts by mass of butyl acrylate ("BA" in Table 1), 3 parts by mass of 2-hydroxyethyl acrylate ("HEA" in Table 1), and 1 part by mass of a light selective absorption monomer represented by UVA-01 (total solid content 100 parts by mass), and 135 parts by mass of ethyl acetate as a solvent were mixed, and the air in the device was replaced with nitrogen to make the air oxygen-free, and the internal temperature was raised to 60°C.

To the obtained mixture, 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 obtained mixture was stored at 60°C for 1 hour, and then ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts/hr while the internal temperature was maintained at 50 to 70°C. The addition of ethyl acetate was stopped when the concentration of the acrylic resin reached 35%, and the internal temperature was further maintained at 50 to 70°C from the start of the addition of ethyl acetate until 12 hours had passed. Ethyl acetate was added to the obtained mixture of the light selective absorbing polymer (A-1) so as to adjust the concentration of the resin component to 20%, thereby preparing an ethyl acetate solution of the light selective absorbing polymer (A-1). The polystyrene-equivalent weight average molecular weight Mw of the light selective absorption polymer (A-1) obtained by GPC was 500,000, and Mw/Mn was 7.5. The glass transition temperature obtained by DSC was -48.4°C.

(Adhesive composition and adhesive layer preparation)

(a) Preparation of adhesive composition

In an ethyl acetate solution (resin concentration: 20%) of a light selectively absorbing polymer (A-1), 0.5 parts of a crosslinking agent (Coronate L, solid content 75%: manufactured by Tosoh) and 0.5 parts of a silane compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with 100 parts of the solid content of the solution, and 2-butanone was further added to a solid content concentration of 14% to obtain an adhesive composition (1). The amount of the crosslinking agent (Coronate L) is the mass fraction of the active ingredient.

(b) Preparation of adhesive layer

The adhesive composition prepared in (a) was applied to the release-treated surface of a polyethylene terephthalate film (SP-PLR382050 manufactured by Lintec Corporation, hereinafter referred to as "spacer film") using an applicator so that the thickness of the adhesive layer after drying would be 17 μm, and dried at 100°C for 1 minute to prepare an adhesive layer. The obtained adhesive layer was set as adhesive layer (1).

<Adhesive layer (2)>

(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 added to a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer. The air in the apparatus was replaced with nitrogen to make the air oxygen-free, and the internal temperature was raised to 60° C. Then, the entire amount of a solution of 0.4 parts of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts of ethyl acetate was added. The obtained mixture was stored at 60°C for 1 hour, and then the internal temperature was maintained at 50 to 70°C, while ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts/hr. The addition of ethyl acetate was stopped when the concentration of the acrylic resin reached 35%, and the mixture was kept at this temperature for 12 hours from the start of the addition of ethyl acetate. Finally, ethyl acetate was added to adjust the concentration of the acrylic resin component to 20%, and an ethyl acetate solution of the acrylic resin was prepared. The polystyrene-converted weight average molecular weight Mw of the obtained acrylic resin obtained by GPC was 600,000, and Mw/Mn was 7.0. The obtained acrylic resin was referred to as acrylic resin (A-2). The glass transition temperature obtained by DSC was -52.9°C.

(Adhesive composition and adhesive layer preparation)

(a) Preparation of adhesive composition

In an ethyl acetate solution of an acrylic resin (A-2) (resin concentration: 20%), 0.5 parts of a crosslinking agent (Coronate L, solid content 75%: manufactured by Tosoh), 0.5 parts of a silane compound (manufactured by Shin-Etsu Chemical: KBM-403), and 2.5 parts of a compound represented by the following formula (aa2) as a light selective absorbing compound (2) in Synthesis Example 2 described in paragraph [0142] of Japanese Patent Publication No. 2019-007001 (light selective absorbing agent) were mixed with respect to 100 parts of the solid content of the solution, and 2-butanone was further added in such a manner that the solid content concentration became 14%, thereby obtaining an adhesive composition (2). In addition, the amount of the crosslinking agent (Coronate L) is the mass fraction of the active ingredient.

(b) Preparation of adhesive layer

The adhesive layer (2) is prepared from the adhesive composition in the same manner as the adhesive layer (1).

[Preparation of the second adhesive layer]

In the ethyl acetate solution of the acrylic resin (A-2) (resin concentration: 20%), 0.5 parts of a crosslinking agent (Coronate L, solid content 75%: manufactured by Tosoh) and 0.5 parts of a silane compound (manufactured by Shin-Etsu Chemical: KBM-403) were mixed, and 2-butanone was further added in such a way that the solid content concentration became 14% to obtain an adhesive composition. In addition, the amount of the crosslinking agent (Coronate L) prepared above is the mass fraction of the active ingredient.

On the release-treated surface of the spacer film used in the preparation of the light-selective absorbing adhesive layer, the adhesive composition is applied using a coater in such a way that the thickness of the adhesive layer after drying becomes 5μm, and dried at 100℃ for 1 minute to prepare the second adhesive layer.

[Fabrication of optical multilayers]

(Implementation Example 1, Comparative Example 1)

The second adhesive layer is laminated on the polarizer side of the manufactured single-sided protected polarizing plate, and the spacer film is peeled off. The surface of the second adhesive layer from which the spacer film has been peeled off and the surface of the manufactured phase difference layer body exposed after the substrate film on the first liquid crystal curing layer side is peeled off are laminated. Thereafter, the substrate film on the second liquid crystal curing layer side is peeled off, and the adhesive layer listed in Table 1 is bonded to the surface of the orientation layer on the second liquid crystal curing layer side as a light selective absorption adhesive layer, thereby obtaining an optical laminate having a layer structure of "protective film A/water-based adhesive/polarizer/second adhesive layer/orientation layer/first liquid crystal curing layer/second liquid crystal curing layer/orientation layer/light selective absorption adhesive layer/spacer film". In the optical laminate, the middle layer has a layer structure of "second adhesive layer/orientation layer/first liquid crystal curing layer/ultraviolet curing adhesive layer/second liquid crystal curing layer/orientation layer", and the total thickness is 11μm. The optical laminate of Example 1 and Comparative Example 1 is set to have the structure shown in Figure 2.

As described above, the adhesive layer was applied using a coater so that the thickness was 5 μm, and dried at 100°C for 1 minute to prepare the second adhesive layer. The total thickness of the "alignment layer/first liquid crystal curing layer" was 2 μm. The total thickness of the "alignment layer/second liquid crystal curing layer" was 3 μm.

The thickness of UV curable adhesive is 1μm.

(Implementation Example 2, Comparative Example 2)

The second adhesive layer is bonded to the polarizer side of the manufactured single-sided protective polarizing plate, and the spacer film is peeled off. The adhesive layer listed in Table 1 is bonded to the surface of the second adhesive layer from which the spacer film has been peeled off as a light selective absorption adhesive layer, and an optical laminate having a layer structure of "protective film A/water-based adhesive/polarizer/second adhesive layer/light selective absorption adhesive layer/spacer film" is obtained. In the optical laminate, the middle layer is composed of the "second adhesive layer" and its thickness is 5μm. The optical laminate of Example 2 and Comparative Example 2 is configured to have a structure as shown in Figure 3.

As described above, the adhesive layer was applied using a coater so that the thickness of the adhesive layer became 5 μm, and dried at 100°C for 1 minute to prepare the second adhesive layer.

[Absorbance measurement of adhesive layer]

Adhesive layers (1) and (2) were bonded to glass, and after the spacer film was peeled off, a cycloolefin polymer (COP) film (ZF-14 manufactured by ZEON Co., Ltd., Japan) was bonded to the adhesive layer to produce a laminate for adhesive layer evaluation. The laminate for adhesive layer evaluation was mounted on a spectrophotometer UV-2450 (manufactured by Shimadzu Corporation) and the absorbance was measured in a wavelength range of 300 to 800 nm with a double beam method and a step of 1 nm. The absorbance of the prepared adhesive layer at a wavelength of 410 nm is shown in Table 1. In addition, the absorbance of the glass and the absorbance of the COP film at a wavelength of 410 nm were both 0.

[Determination of weight average molecular weight (Mw)]

The weight average molecular weight (Mw) of the photoselective absorbing polymer (A-1) and the acrylic resin (A-2) was determined as the number average molecular weight (Mn) converted to polystyrene by using tetrahydrofuran as the mobile phase by the following size separation chromatography (SEC). The (meth)acrylic polymer to be measured was dissolved in tetrahydrofuran at a concentration of about 0.05 mass %, and 10 μL was injected into SEC. The mobile phase flowed at a flow rate of 1.0 mL/min. The column used was PLgel MIXED-B (manufactured by Polymer Laboratories). The detector used was a UV-VIS detector (trade name: Agilent GPC).

[Determination of Boron Content]

Dissolve 0.2g of polarizer in 200g of 1.9wt% mannitol aqueous solution. Titrate the obtained aqueous solution with 1mol/L NaOH aqueous solution, compare the amount of NaOH solution required for neutralization and the calibration curve, and calculate the boron content of the polarizer.

[Wet and heat resistance test and observation of discoloration]

The optical laminate obtained in Examples 1 and 2 and Comparative Examples 1 and 2 was peeled off from the spacer film, bonded to an alkali-free glass plate, and placed in an environment of 65°C and 90%RH for 500 hours. After that, a polarizing plate with a crossed nicols relationship was bonded to the alkali-free glass surface opposite to the optical laminate under test, and observed with an optical microscope, and the observed image was preserved. The optical microscope used was "VHX-500" manufactured by KEYENCE Co., Ltd. FIG4 shows an example of an image observed with an optical microscope. In Figure 3, if we observe along the straight line indicated by the arrow from the end 50 of the optical laminate toward the inner side (the straight line extending from the end 50 in the vertical direction), we can see that there is a decolorized area 51 and an area where decolorization does not occur (non-decolorized area) 52.

[Measurement of decolorization using image processing]

The image observed under a microscope was converted into 256 gray levels (0 to 255) using the image analysis software "ImageJ (free software)". The method of converting into 256 gray levels (0 to 255) is to use the method of taking the average of the RGB values. Figure 5 shows an example of the converted data. The middle point (middle of the decolorized color gradient) between the decolorized area 51 and the non-decolorized area 52 in the gradation distribution in the vertical direction relative to the end 50 of the optical stack (arrow in Figure 4) is taken as the decolorized end of the optical stack (Figure 5), and the distance (μm) from the end 50 of the optical stack to the decolorized end is measured as the decolorization distance. The decolorization distance of the optical multilayer is shown in Table 1. The smaller the decolorization distance, the narrower the decolorization range and the better the moisture and heat resistance.

The decolorization distances of optical laminates with the same layer structure are compared (Example 1 and Comparative Example 1, Example 2 and Comparative Example 2), and the difference and improvement rate of the decolorization distance [(absolute value of the difference/decolorization distances of Comparative Examples 1 and 2) × 100] are shown in Table 1.

[Table 1]

10: Polarizer

11: Protective film

20: Photoselective absorbent adhesive layer

100: Optical multilayers

300: Middle layer

Claims (10)

An optical laminate having a polarizer, a light selective absorption adhesive layer, and an intermediate layer laminated between the polarizer and the light selective absorption adhesive layer and in contact with the polarizer and the light selective absorption adhesive layer; wherein the intermediate layer is a laminate of one or more layers selected from the group consisting of a liquid crystal curing layer, an orientation layer, and a bonding layer, and the liquid crystal curing layer; the polarizer is iodine-adsorbed and oriented, and the boron content is 5.0 mass % or less; and the adhesive composition forming the light selective absorption adhesive layer includes a light selective absorption polymer. The optical laminate as described in claim 1 further has a protective film, which is laminated on the side of the polarizer opposite to the intermediate layer. An optical laminate as described in claim 1 or 2, wherein the aforementioned light selectively absorbing polymer is a resin containing a structural unit having a structure shown by the following chemical formula (1) and having a glass transition temperature of 40°C or less, >N-C=C-C=C< (1) However, not all of the 1 N atom and 4 C atoms constituting the chemical formula (1) constitute part or all of an aromatic heterocyclic ring. The optical laminate as described in claim 3, wherein the content of the structural unit having the structure shown by the above chemical formula (1) in the above light selective absorption polymer is 0.01 mass parts or more and 50 mass parts or less relative to 100 mass parts of all structural units. The optical multilayer as described in claim 1 or 2, wherein the weight average molecular weight of the aforementioned light selective absorption polymer is greater than 300,000. An optical laminate as described in claim 1 or 2, wherein the adhesive composition does not contain a light selective absorber, or the content of the light selective absorber is more than 0 parts by mass and less than 0.5 parts by mass relative to 100 parts by mass of the total resin component. An optical multilayer as described in claim 1 or 2, wherein the intermediate layer has a λ/4 phase difference layer belonging to the liquid crystal curing layer. The optical layered body as described in claim 1 or 2 is a polarizing plate for anti-reflection. An image display device includes an image display panel and the optical multilayer body described in claim 8 disposed on the front surface of the image display panel. The image display device as described in claim 9 is an organic EL display device.