JP7355955B1 - optical laminate - Google Patents

Abstract

[Problem] To configure an image display device in which even when a displayed image is viewed through polarized sunglasses, the image can be viewed regardless of the display angle, and the difference in color tone depending on the display angle is reduced. To provide an optical laminate that can. [Solution] The first retardation plate has a first retardation plate, a polarizer, a second retardation plate, and an adhesive layer in this order, the first retardation plate satisfies the relationship of the following formula (1), and the second retardation plate The retardation plate is an optical laminate that includes two or more retardation layers containing a cured liquid crystal obtained by polymerizing a polymerizable liquid crystal compound, and satisfies the following formulas (2) and (3). 1.0≦Re1(450)/Re1(550) (1) 70nm≦Re2(450)≦130nm (2) Re2(450)/Re2(550)≦1.0 (3) [Selection diagram] Figure 1

Description

The present invention relates to an optical laminate.

Conventionally, in image display devices, a method has been adopted in which a circularly polarizing plate is disposed on the viewing side of an image display panel to suppress a decrease in visibility due to reflection of external light.

A circularly polarizing plate is an optical laminate in which a polarizer and a retardation plate are laminated. In a circularly polarizing plate, external light directed toward an image display panel is converted into linearly polarized light by a polarizer, and then converted into circularly polarized light by a subsequent retardation plate. External light, which is circularly polarized light, is reflected on the surface of the image display panel, but upon this reflection, the direction of rotation of the plane of polarization is reversed, and after being converted to linearly polarized light by the retardation plate, it is blocked by the subsequent polarizer. Ru. As a result, emission of extraneous light to the outside is suppressed. As a configuration of a circularly polarizing plate, a configuration having a retardation plate containing a cured product of a liquid crystal compound is known (for example, Patent Document 1).

JP2016-27431A

Portable image display devices such as smartphones are typically configured so that they can be used at different display angles, such as vertically and horizontally. When a portable image display device is used outdoors, the displayed image may be viewed through polarized sunglasses. When viewing a displayed image through polarized sunglasses, the image may not be visible or the color of the image may vary depending on the viewing angle.

According to the present invention, reflected light is suppressed, and even when a displayed image is viewed through polarized sunglasses, it can be viewed regardless of the viewing angle, and differences in color tone depending on the viewing angle are reduced. An object of the present invention is to provide an optical laminate that can constitute an image display device.

The present invention provides the following optical laminate.
[1] Having a first retardation plate, a polarizer, a second retardation plate, and an adhesive layer in this order,
The first retardation plate is
It is arranged so that the angle θ1 of its slow axis with respect to the absorption axis of the polarizer is 40° to 50° or -40° to -50°, and has an in-plane retardation value for light with a wavelength of λ nm. When Re1(λ), the following formula (1) is satisfied,
The second retardation plate is
Containing two or more retardation layers containing a cured liquid crystal obtained by polymerizing a polymerizable liquid crystal compound,
At least two of the two or more retardation layers have slow axes that intersect with each other in the plane,
An optical laminate that satisfies the relationships of formulas (2) and (3) below, where Re2 (λ) is the in-plane retardation value for light with a wavelength of λ nm.
1.0≦Re1(450)/Re1(550) (1)
70nm≦Re2(450)≦130nm (2)
Re2(450)/Re2(550)≦1.0 (3)
[2] The optical laminate according to [1], wherein the first retardation plate is a stretched thermoplastic resin film and has a thickness of 10 μm to 100 μm.
[3] The optical laminate according to claim 1 or 2, wherein in the first retardation plate, the Re1(λ) satisfies the following formulas (4) and (5).
100nm≦Re1(450)≦130nm (4)
100nm≦Re1(550)≦130nm (5)
[4] Further comprising a protective film disposed between the polarizer and the second retardation plate,
The optical laminate according to [1] or [2], wherein the protective film has an in-plane retardation value of 0 nm to 20 nm for light with a wavelength of 550 nm.
[5] The optical laminate according to [1] or [2], wherein the slow axes of at least two of the retardation layers constituting the second retardation plate intersect in a plane.
[6] Among the two or more retardation layers constituting the second retardation plate, the first layer, which is the layer closest to the polarizer, has a slow axis with respect to the absorption axis of the polarizer. The optical laminate according to [1] or [2], wherein the angle θ2 is 10° to 20° or -10° to -20°.
[7] Among the two or more retardation layers constituting the second retardation plate, the first layer, which is the layer closest to the polarizer, has a slow axis with respect to the absorption axis of the polarizer. The optical laminate according to [1] or [2], wherein the sign of the angle θ2 is opposite to the sign of the angle θ1.
[8] Further comprising a layer having predetermined ultraviolet absorption characteristics on the surface of the first retardation plate opposite to the polarizer,
The predetermined ultraviolet absorption characteristic is a characteristic that satisfies the relationships of the following formulas (6), (7), and (8), where the transmittance of light with a wavelength of λ nm is Tr (λ), [1] or [ 2]. The optical laminate according to item 2.
Tr(450)≧85% (6)
30%≦Tr(420)≦75% (7)
0%≦Tr(400)≦10% (8)

According to the present invention, reflected light is suppressed, and even when a displayed image is viewed through polarized sunglasses, it can be viewed regardless of the viewing angle, and differences in color tone depending on the viewing angle are reduced. It is possible to provide an optical laminate that can constitute an image display device.

FIG. 1 is a schematic cross-sectional view schematically showing an example of an optical laminate according to the present embodiment.

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following embodiments. In the following drawings, each component is shown adjusted to an appropriate scale to make it easier to understand, and the scale of each component shown in the drawings does not necessarily match the actual scale of the component.

[Optical laminate]
The optical laminate of the present invention includes a first retardation plate, a polarizer, a second retardation plate, and an adhesive layer in this order.
The first retardation plate is arranged such that an angle θ1 of its slow axis with respect to the absorption axis of the polarizer is 40° to 50° or -40° to -50°, and the first retardation plate is arranged so that the angle θ1 between the slow axis and the absorption axis of the polarizer is 40° to 50° or -40° to -50°, and When the in-plane retardation value of is Re1(λ), the following equation (1) is satisfied.
1.0≦Re1(450)/Re1(550) (1)
By arranging the optical laminate having the first retardation plate satisfying the above formula (1) in front of the image display device, even when the displayed image is viewed through polarized sunglasses, it does not depend on the display angle. In addition, the difference in color depending on the display angle is reduced, and visibility can be improved.

The second retardation plate includes two or more retardation layers containing a cured liquid crystal obtained by polymerizing a polymerizable liquid crystal compound, and at least two of the two or more retardation films have their slow axes in plane with each other. If Re2(λ) is the in-plane retardation value of light that intersects within and has a wavelength of λnm, then the following equations (2) and (3) are satisfied.
70nm≦Re2(450)≦130nm (2)
Re2(450)/Re2(550)≦1.0 (3)
The two or more retardation layers constituting the second retardation plate are expressed by formula (1-2)
1.0≦Re2(450)/Re2(550) (1-2)
It is preferable that the following relationship is satisfied.
The second retardation plate satisfies the relationships of formulas (2) and (3) above, and all of the two or more retardation layers constituting the second retardation plate satisfy the relationship of formula (1-2). By arranging an optical laminate that satisfies the above conditions in front of an image display device, reflected light can be suppressed and coloring of the reflected light can be suppressed.

FIG. 1 is a schematic cross-sectional view schematically showing an example of an optical laminate according to this embodiment. As shown in FIG. 1, the optical laminate 1 includes, from the front side, a surface treatment layer 11, a first protective film 12, a first bonding layer 13, a polarizer 14, a second bonding layer 15, and a second protective film. 16, a third bonding layer 17, a second retardation plate 18, and an adhesive layer 19, which are laminated in this order in the thickness direction.

In this specification, a component including a polarizer is also referred to as a linear polarizing plate. The linear polarizing plate may consist only of a polarizer, or may include components other than the polarizer. In the optical laminate 1, the layer constituent parts consisting of the surface treatment layer 11, the first protective film 12, the first bonding layer 13, the polarizer 14, the second bonding layer 15, and the second protective film 16 are combined into a linear polarizing plate 10. It is called.

In the optical laminate 1, the first protective film 12 corresponds to a first retardation plate. The first retardation plate may be a component included in the linearly polarizing plate, or may be a component provided separately from the linearly polarizing plate. Each layer shown in FIG. 1 may have a single layer structure or a plurality of layers. The optical laminate 1 may have a structure having layers other than those shown in FIG. 1, or may have a structure not having some of the layers shown in FIG. Good too.

[Linear polarizing plate]
A linear polarizing plate is a film having a light absorption anisotropic function, and generally includes a polarizer in which dichroic dye is uniaxially aligned. In order to uniaxially align dichroic dyes, a film (hereinafter also referred to as a "polarizer") obtained by impregnating iodine or an organic dichroic dye into a polymer such as PVA and uniaxially stretching the film (hereinafter also referred to as a "polarizer") or a polymerizable liquid crystal A polymerizable compound containing a dichroic dye formed by orienting a dichroic dye and a polymerizable liquid crystal compound from a composition containing a compound and a dichroic dye (hereinafter also referred to as a "composition for forming a polarizing film") It can be produced from an optically anisotropic layer (hereinafter also referred to as a "polarizing film") made of a polymer of a liquid crystal compound. That is, the dichroic dye included in the stretched polymer or the polymerizable liquid crystal compound exhibits a polarizing function by anisotropically absorbing light.

The polarization performance of a linear polarizing plate can be measured using a spectrophotometer. For example, the transmittance (T1) in the transmission axis direction (orientation perpendicular direction) and the transmittance (T2) in the absorption axis direction (orientation direction) in the wavelength range of 380 nm to 780 nm, which is visible light, can be measured using a spectrophotometer using a prism polarizer. It can be measured using the double beam method using a device equipped with Polarization performance in the visible light range is determined by calculating the single transmittance and degree of polarization at each wavelength using the following formulas (11) and (12), and further calculating the visibility using the 2-degree field of view (C light source) of JIS Z 8701. By performing the correction, it is possible to calculate using the visibility correction single transmittance (Ty) and the visibility correction polarization degree (Py). In addition, by calculating the chromaticity a ^* and b ^* in the L ^* a ^* b ^* (CIE) color system using the color matching function of the C light source from the transmittance measured in the same way, we can calculate the chromaticity of the linear polarizing plate alone. A hue (single hue), a hue with linearly polarizing plates arranged in parallel (parallel hue), and a hue with linearly polarizing plates arranged orthogonally (orthogonal hue) can be obtained. The closer the values of a ^* and b ^* are to 0, the more neutral the hue can be determined.
Single transmittance (%) = (T1+T2)/2 (11)
Degree of polarization (%) = (T1-T2)/(T1+T2)×100 (12)

The visibility correction polarization degree Py of the linear polarizing plate is usually 80% or more, preferably 90% or more, more preferably 95% or more, still more preferably 98% or more, particularly preferably 99% or more, and 99. If it is 9% or more, it can be suitably used for liquid crystal displays. Increasing the visibility correction polarization degree Py of the linear polarizing plate is advantageous in improving the antireflection function of the optical laminate. If the visibility correction polarization degree Py is less than 80%, the antireflection function may not be achieved when used as an antireflection film.

As the visibility correction single transmittance Ty of a linear polarizing plate increases, the clarity during white display increases, but as can be seen from the relationship between equations (11) and (12), if the single transmittance is made too high, the polarization There is a problem with the degree of deterioration. Therefore, it is preferably 30% or more and 60% or less, more preferably 35% or more and 55% or less, even more preferably 40% or more and 50% or less, and still more preferably 40% or more and 45% or less. If the visibility correction single transmittance Ty is too high, the visibility correction polarization degree Py will be too low, and the antireflection function may be insufficient when used as an antireflection film.

<Polarizer formed from film>
A polarizer, which is a film made by uniaxially stretching a polymer such as PVA impregnated with iodine or an organic dichroic dye, is usually produced through a process of uniaxially stretching a polyvinyl alcohol resin film. A process of dyeing with a dichroic dye to adsorb the dichroic dye, a process of treating a polyvinyl alcohol resin film with the dichroic dye adsorbed with an aqueous boric acid solution, and a process with an aqueous boric acid solution. It can be manufactured through a subsequent step of washing with water.

The thickness of the polarizer is usually 30 μm or less, preferably 18 μm or less, more preferably 15 μm or less, and still more preferably 10 μm or less. The thickness is usually 1 μm or more, and may be, for example, 5 μm or more.

Uniaxial stretching of the polyvinyl alcohol film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during the boric acid treatment. Of course, uniaxial stretching can also be performed in multiple stages as shown here. Uniaxial stretching methods include stretching uniaxially in the film transport direction between rolls with different circumferential speeds, stretching uniaxially in the film transport direction using hot rolls, and stretching in the width direction using a tenter. can be adopted. Further, the uniaxial stretching may be carried out by dry stretching in the atmosphere, or by wet stretching in which the polyvinyl alcohol film is stretched in a swollen state using a solvent such as water. The stretching ratio is usually about 3 to 8 times. Alternatively, after applying an aqueous solution containing polyvinyl alcohol onto a thermoplastic resin film, a drying treatment may be performed, and the film may be stretched together with the thermoplastic resin film by the above method.

Staining of a polyvinyl alcohol film with a dichroic dye can be carried out, for example, by immersing the polyvinyl alcohol film in an aqueous solution containing the dichroic dye. Specifically, iodine and dichroic organic dyes are used as the dichroic dye.

<Polarizer formed from coating film>
A polarizer, which is an optically anisotropic layer made of a polymer of a polymerizable liquid crystal compound containing a dichroic dye, has the advantage of being able to arbitrarily control the hue, being able to be made significantly thinner, and being able to resist stretching relaxation due to heat. Since it has no shrinkage properties, it can be suitably used for flexible display applications, for example.

A polarizer is formed by applying a polarizer-forming composition onto an alignment film formed on a base material as necessary, and aligning the dichroic dye contained in the polarizer-forming composition. be done. The polarizer is a film having a thickness of 0.1 μm or more and 5 μm or less, more preferably 0.3 μm or more and 4 μm or less, and even more preferably 0.5 μm or more and 3 μm or less. If the film thickness becomes thinner than this range, the necessary light absorption may not be obtained, and if the film thickness becomes thicker than this range, the alignment control force of the alignment film decreases, which tends to cause alignment defects. It is in. Furthermore, the polarizer-forming composition may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, and the like.

An optically anisotropic layer in which a dichroic dye and a polymerizable liquid crystal compound are aligned horizontally to the substrate surface has an absorbance A1 (λ) in the alignment direction and an absorbance A2 (λ) in the vertical direction within the alignment plane for light with a wavelength of λ nm. The ratio (dichroic ratio) is preferably 7 or more, more preferably 20 or more, and still more preferably 40 or more. The higher this value is, the better the absorption selectivity of the polarizing plate is. Although it depends on the type of dichroic dye, it is about 5 to 10 in the case of a liquid crystal cured film cured in a nematic liquid crystal phase state.

By mixing two or more types of dichroic dyes with different absorption wavelengths, polarizers with various hues can be produced, and polarizers having absorption in the entire visible light range can be produced. A polarizer having such absorption characteristics can be used in a variety of applications.

(Polymerizable liquid crystal compound)
A polymerizable liquid crystal compound is a compound that has a polymerizable group and has liquid crystal properties (hereinafter also referred to as a polymerizable liquid crystal). A polymerizable group means a group that participates in a polymerization reaction, and is preferably a photopolymerizable group. Here, the photopolymerizable group refers to a group that can participate in a polymerization reaction by active radicals, acids, etc. generated from a photopolymerization initiator, which will be described later. Examples of the polymerizable group include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, oxiranyl group, oxetanyl group, and the like. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferred, and methacryloyloxy group or acryloyloxy group is more preferred. The liquid crystal may be either thermotropic liquid crystal or lyotropic liquid crystal, but thermotropic liquid crystal is preferable when mixed with a dichroic dye described below. The polymerizable liquid crystal compound may be a monomer or a polymer obtained by polymerizing dimers or more.

When the polymerizable liquid crystal compound is a thermotropic liquid crystal, it may be a thermotropic liquid crystal compound exhibiting a nematic liquid crystal phase or a thermotropic liquid crystal compound exhibiting a smectic liquid crystal phase. The liquid crystal state of the polymerizable liquid crystal compound is preferably a smectic phase from the viewpoint of being able to exhibit high dichroism, and more preferably a higher-order smectic phase from the viewpoint of improving performance. Among them, higher-order smectic liquid crystal compounds forming smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase or smectic L phase are used. More preferred are higher-order smectic liquid crystal compounds that form a smectic B phase, smectic F phase, or smectic I phase. When the liquid crystal phase formed by the polymerizable liquid crystal is one of these higher-order smectic phases, a polarizer with higher polarization performance can be manufactured. In addition, a polarizer with such high polarization performance can obtain a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement. The Bragg peak is a peak derived from the periodic structure of molecular orientation, and a film having a periodic interval of 3 to 6 Å can be obtained. In the polarizer of the present invention, it is preferable that the polymerizable liquid crystal contains a polymer of a polymerizable liquid crystal oriented in a smectic phase state from the viewpoint of obtaining higher polarization characteristics.

As the polymerizable liquid crystal compound, one type may be used alone, or two or more types may be used in combination. The polymerizable liquid crystal composition containing other compounds described below may contain other polymerizable liquid crystal compounds other than the polymerizable liquid crystal compound as long as the effects of the present invention are not impaired. From the viewpoint of obtaining, the proportion of the polymerizable liquid crystal compound to the total mass of all polymerizable liquid crystal compounds contained in the polymerizable liquid crystal composition is preferably 51% by mass or more, more preferably 70% by mass or more, and Preferably it is 80% by mass or more.

The content of the polymerizable liquid crystal compound in the composition for forming a polarizer of the present invention is preferably 40 to 99.9% by mass, more preferably 60 to 99% by mass based on the solid content of the polymerizable liquid crystal composition. %, more preferably 70 to 99% by mass. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high. Note that in this specification, the solid content refers to the total amount of components excluding the solvent from the polymerizable liquid crystal composition.

(dichroic dye)
A dichroic dye refers to a dye that has a property that the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. The dichroic dye preferably has a property of absorbing visible light, and more preferably has a maximum absorption wavelength (λMAX) in the range of 380 to 680 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes, and anthraquinone dyes, among which azo dyes are preferred. Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakisazo dyes, and stilbene azo dyes, with bisazo dyes and trisazo dyes being preferred. Dichroic dyes may be used alone or in combination, but in order to obtain absorption in the entire visible light range, it is preferable to combine two or more types of dichroic dyes, and it is preferable to combine three or more types of dichroic dyes. is more preferable.

Examples of the azo dye include a compound represented by formula (XVI) (hereinafter sometimes referred to as "compound (XVI)").
T ¹ -A ¹ (-N=NA ² ) _p -N=NA ³ -T ² (XVI)
[In formula (XVI), A ¹ , A ² and A ³ are each independently a 1,4-phenylene group which may have a substituent, a naphthalene-1 which may have a substituent, 4-diyl group, benzoic acid phenyl ester group which may have a substituent, 4,4'-stilbenylene group which may have a substituent, or divalent group which may have a substituent. It represents a heterocyclic group, and T ¹ and T ² are electron-withdrawing groups or electron-emitting groups, and are located at substantially 180° with respect to the azo bond plane. p represents an integer from 0 to 4. When p is 2 or more, each A ² may be the same or different from each other. The -N=N- bond may be replaced by a -C=C-, -COO-, -NHCO-, or -N=CH- bond within a range that exhibits absorption in the visible region. ]

The content of the dichroic dye (the total amount if multiple types are included) is usually 1 to 60 parts by mass based on 100 parts by mass of the polymerizable liquid crystal compound, from the viewpoint of obtaining good light absorption characteristics. The amount is preferably 1 to 40 parts by weight, more preferably 1 to 20 parts by weight. If the content of the dichroic dye is less than this range, light absorption will be insufficient and sufficient polarization performance will not be obtained, and if it is more than this range, the alignment of liquid crystal molecules may be inhibited.

<Method for manufacturing polarizer formed from film>
Polarizers are usually produced through a process of uniaxially stretching a PVA film, a process of dyeing the PVA film with a dichroic dye to adsorb the dichroic dye, and a process of honing the PVA film to which the dichroic dye has been adsorbed. It is manufactured through a process of crosslinking by treatment with an aqueous acid solution, and a process of washing with water after crosslinking with an aqueous boric acid solution (hereinafter also referred to as boric acid treatment).

The uniaxial stretching of the PVA-based film can be performed before, simultaneously with, or after dyeing with a dichroic dye. When uniaxial stretching is performed after dyeing, this uniaxial stretching may be performed before or during the boric acid treatment. Of course, uniaxial stretching can also be performed in multiple stages as shown here. Uniaxial stretching methods include stretching uniaxially in the film transport direction between rolls with different circumferential speeds, stretching uniaxially in the film transport direction using hot rolls, and stretching in the width direction using a tenter. can be adopted. Further, the uniaxial stretching may be carried out by dry stretching in the atmosphere, or by wet stretching in which the PVA film is stretched in a swollen state using a solvent such as water. The stretching ratio is usually about 3 to 8 times.

Dyeing a PVA film with a dichroic dye can be carried out, for example, by immersing the PVA film in an aqueous solution containing the dichroic dye. Specifically, iodine and dichroic organic dyes are used as the dichroic dye. In addition, it is preferable that the PVA film is immersed in water and swelled before the dyeing process.

When using iodine as a dichroic dye, a method of dyeing the PVA film by immersing it in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water, and the content of potassium iodide is usually about 0.5 to 20 parts by mass per 100 parts by mass of water. It is. The temperature of the aqueous solution used for dyeing is usually about 20 to 40°C. The immersion time (staining time) in this aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when using a dichroic organic dye as the dichroic dye, a method of dyeing the PVA film by immersing it in an aqueous solution containing a water-soluble dichroic organic dye is usually employed. The content of the dichroic organic dye in this aqueous solution is usually about 0.0001 to 10 parts by weight, preferably 0.001 to 1 part by weight, per 100 parts by weight of water. This aqueous dye solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic organic dye aqueous solution used for dyeing is usually about 20 to 80°C. The immersion time (staining time) in this aqueous solution is usually about 10 to 1,800 seconds.

The boric acid treatment after dyeing with a dichroic dye can be performed by immersing the dyed PVA film in an aqueous solution containing boric acid. The content of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. When using iodine as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The content of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by weight, preferably 5 to 12 parts by weight, per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50°C or higher, preferably 50 to 85°C, more preferably 60 to 80°C.

After the boric acid treatment, the PVA film is usually washed with water. The water washing treatment can be performed, for example, by immersing a boric acid-treated PVA film in water. The temperature of water in the washing process is usually about 5 to 40°C. The immersion time is usually about 1 to 120 seconds.

After washing with water, a drying process is performed to obtain a polarizer. The drying process can be performed using a hot air dryer or a far-infrared heater. The temperature of the drying treatment is usually about 30 to 100°C, preferably 50 to 80°C. The drying time is usually about 60 to 600 seconds, preferably 120 to 600 seconds. The drying process reduces the moisture content in the polarizer to a practical level. The moisture content is usually about 5 to 20% by mass, preferably 8 to 15% by mass, based on the total mass of the polarizer. When the moisture content is 5% by mass or more, the polarizer has sufficient flexibility, so it can be prevented from being damaged or broken after drying. Further, when the moisture content is 20% by mass or less, the polarizer has sufficient thermal stability.

In the manner described above, a polarizer in which a dichroic dye is adsorbed and oriented on a PVA film can be manufactured.

Moreover, the polarizer obtained above may further have a protective film bonded to one or both surfaces thereof via the adhesive.

<Protective film>
The protective film has the function of protecting the surface of the polarizer. The polarizer and the protective film may be directly laminated to each other. Here, "directly laminated" includes an aspect in which the protective film is laminated on the polarizer due to its self-adhesive property, and an aspect in which the protective film is laminated via an adhesive or a pressure-sensitive adhesive. The protective film may be subjected to surface treatment (for example, corona treatment, etc.) in order to improve its adhesion to the polarizer, and a thin layer such as a primer layer (also referred to as an easy-to-adhesion layer) may be formed. Good too.

As the protective film, for example, a resin film having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, stretchability, etc. can also be used. The resin film may be a thermoplastic resin film. Specific examples of such resins include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether sulfone resins; polysulfone resins; polycarbonate resins; nylon and aromatic polyamides. polyamide resins such as; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin resins with cyclo and norbornene structures (also referred to as norbornene resins); polymethyl methacrylate, etc. Examples include (meth)acrylic resins; polyarylate resins; polystyrene resins; polyvinyl alcohol resins, and mixtures thereof. Protective films made of such materials are easily available on the market. Further, thermosetting resins or ultraviolet curable resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone resins may also be mentioned.

Chain polyolefin resins include polyethylene resins (polyethylene resins that are homopolymers of ethylene and copolymers mainly composed of ethylene), polypropylene resins (polypropylene resins that are homopolymers of propylene, and copolymers mainly composed of propylene). In addition to homopolymers of chain olefins such as (copolymers), copolymers consisting of two or more types of chain olefins can be mentioned.

Cyclic polyolefin resin is a general term for resins that are polymerized using cyclic olefins as polymerization units, and is described, for example, in JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, etc. Examples include resins that are Specific examples of cyclic polyolefin resins include ring-opening (co)polymers of cyclic olefins, addition polymers of cyclic olefins, and copolymers of cyclic olefins with chain olefins such as ethylene and propylene (typically is a random copolymer), a graft polymer obtained by modifying these with an unsaturated carboxylic acid or a derivative thereof, and a hydrogenated product thereof. Among these, a norbornene resin using a norbornene monomer such as norbornene or a polycyclic norbornene monomer as the cyclic olefin is preferably used.

A polyester resin is a resin having an ester bond in its main chain, and is generally a polycondensate of a polyhydric carboxylic acid or its derivative and a polyhydric alcohol. As the polyvalent carboxylic acid or its derivative, divalent dicarboxylic acid or its derivative can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, dimethyl naphthalene dicarboxylate, and the like. As the polyhydric alcohol, divalent diols can be used, such as ethylene glycol, propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol. A typical example of polyester resin is polyethylene terephthalate, which is a polycondensate of terephthalic acid and ethylene glycol.

Cellulose ester resin is an ester of cellulose and fatty acid. Specific examples of cellulose ester resins include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Also included are copolymers having multiple types of polymerized units constituting these cellulose ester resins, and those in which some of the hydroxyl groups are modified with other substituents. Among these, cellulose triacetate (triacetylcellulose) is particularly preferred.

A (meth)acrylic resin is a resin whose main constituent monomer is a compound having a (meth)acryloyl group. Specific examples of (meth)acrylic resins include poly(meth)acrylic esters such as polymethyl methacrylate; methyl methacrylate-(meth)acrylic acid copolymers; methyl methacrylate-(meth)acrylic acid Ester copolymer; Methyl methacrylate-acrylic ester-(meth)acrylic acid copolymer; Methyl (meth)acrylate-styrene copolymer (MS resin, etc.); Methyl methacrylate and alicyclic hydrocarbon group (eg, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-norbornyl (meth)acrylate copolymer, etc.). Preferably, a polymer containing poly(meth)acrylic acid C1-6 alkyl ester as a main component such as poly(meth)acrylic acid methyl ester is used, and more preferably, a polymer containing methyl methacrylate as a main component (50 to 100% by weight) is used. %, preferably 70 to 100% by weight).

Polycarbonate resins are made of polymers in which monomer units are bonded via carbonate groups. The polycarbonate resin may be a resin called a modified polycarbonate in which the polymer skeleton is modified, a copolymerized polycarbonate, or the like. Details of the polycarbonate resin are described in, for example, Japanese Patent Application Laid-Open No. 2012-31370. The description of this patent document is incorporated herein by reference.

The thickness of the protective film is preferably 0.1 μm to 60 μm, more preferably 0.5 μm to 40 μm, even more preferably 1 μm to 30 μm.

The protective film can be used by arranging it so that it is closer to the viewer than the polarizer. Therefore, the protective film may be subjected to surface treatments such as hard coat treatment, antireflection treatment, antisticking treatment, and antiglare treatment, as necessary. Additionally/or, if necessary, the protective film may be treated to improve visibility when viewed through polarized sunglasses (typically, imparting an (elliptical) polarization function, ultra-high retardation, etc.). may be applied. By performing such processing, excellent visibility can be achieved even when the display screen is viewed through polarized lenses such as polarized sunglasses. Therefore, the polarizing plate with a retardation plate can be suitably applied to an image display device that can be used outdoors. In the optical laminate 1, the first protective film 11 disposed closer to the viewing side than the polarizer 14 is a first retardation plate provided with a retardation. The first retardation plate will be explained in detail later.

A protective film can be produced by stretching a film containing the above thermoplastic resin. Examples of the stretching treatment include uniaxial stretching and biaxial stretching. Examples of the stretching direction include the machine flow direction (MD) of the unstretched film, a direction perpendicular thereto (TD), and a direction oblique to the machine flow direction (MD). The biaxial stretching may be simultaneous biaxial stretching in which the film is stretched in two stretching directions simultaneously, or sequential biaxial stretching in which the film is stretched in a predetermined direction and then in another direction. Stretching treatment can be carried out, for example, by using two or more pairs of nip rolls with a high circumferential speed on the exit side to stretch the film in the longitudinal direction (machine flow direction: MD), or by gripping both ends of the unstretched film with chucks and mechanical flow. This can be done by spreading it in the direction (TD) orthogonal to the direction (TD). At this time, it is possible to control the retardation value and wavelength dispersion by adjusting the thickness of the film or adjusting the stretching ratio. Further, the wavelength dispersion value can be controlled by adding a wavelength dispersion adjusting agent to the resin.

The protective film may contain any suitable additives depending on the purpose. Examples of additives include antioxidants such as hindered phenol, phosphorus, and sulfur; stabilizers such as light stabilizers, ultraviolet absorbers, weather stabilizers, and heat stabilizers; and stabilizers such as glass fibers and carbon fibers. Reinforcing materials; near-infrared absorbers; flame retardants such as tris(dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; antistatic agents such as anionic, cationic, and nonionic surfactants; inorganic pigments, organic pigments, Coloring agents such as dyes; organic fillers and inorganic fillers; resin modifiers; plasticizers; lubricants; retardation reducing agents and the like. The type, combination, content, etc. of the additives contained can be appropriately set depending on the purpose and desired characteristics.

Additionally, a surface treatment layer can be provided on the outer surface of the protective film to impart desired surface optical properties or other characteristics. Specific examples of the surface treatment layer include a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, and an antifouling layer. The method for forming the surface treatment layer is not particularly limited, and any known method can be used. The surface treatment layer may be formed on one side or both sides of the protective film.

In the optical laminate 1, the first protective film 12 and the second protective film 16 correspond to the above-mentioned protective films. In the optical laminate 1, the first protective film 11 is a protective film disposed on the viewing side of the polarizer 14, and the surface treatment layer 11 is formed on the viewing side surface thereof. The second protective film 16 is arranged between the polarizer 14 and the second retardation plate 18. The second protective film 16 preferably has an in-plane retardation value of 0 nm to 20 nm for light with a wavelength of 550 nm, and preferably has an in-plane retardation value of 0 nm to 10 nm, from the viewpoint of suppressing coloration of reflected light from an image display device observed from an oblique direction. It is more preferably 0 nm to 5 nm, and ideally 0 nm.

<Surface treatment layer>
The surface treatment layer has a function of increasing the surface hardness of the protective film, and is provided for the purpose of preventing scratches on the surface. The surface treatment layer was tested by the pencil hardness test (pencil hardness) specified in JIS K 5600-5-4: 1999 "General test methods for paints - Part 5: Mechanical properties of coating films - Section 4: Scratch hardness (pencil method)". The pencil hardness measured by placing an optical film having a surface treatment layer on a glass plate is preferably H or a value harder than that.

The material forming the surface treatment layer is generally cured by heat or light. Examples include organic hard coat materials such as organic silicone, melamine, epoxy, (meth)acrylic, and urethane (meth)acrylate, and inorganic hard coat materials such as silicon dioxide. Among these, urethane (meth)acrylate-based or polyfunctional (meth)acrylate-based hard coat materials are preferably used because they have good adhesion to the protective film and are excellent in productivity.

The surface treatment layer contains various fillers, if desired, for the purpose of adjusting the refractive index, improving the flexural modulus, stabilizing the volume shrinkage rate, and further improving heat resistance, antistatic properties, anti-glare properties, etc. can do. The surface treatment layer can also contain additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, leveling agents, and antifoaming agents.

The surface treatment layer may contain additives to further improve the strength. The additive is not limited, and may include inorganic fine particles, organic fine particles, or a mixture thereof. In addition, the thickness of the surface treatment layer may be 1 μm to 20 μm, or even 2 μm to 10 μm, since it is better to be thick in order to have hardness, but if it is too thick, it will break easily when cutting. good. The thickness of the surface treatment layer is preferably 3 μm to 7 μm.

The anti-glare layer is a layer having fine irregularities on its surface, and is preferably formed using the above-mentioned hard coat material.

The anti-glare layer having fine irregularities on the surface can be produced by 1) forming a coating film containing fine particles on a stretched film and providing irregularities based on the fine particles, and 2) coating with or without fine particles. After forming a film on a stretched film, it can be formed by a method (also called an embossing method) in which the film is pressed against a mold (such as a roll) whose surface is provided with an uneven shape to transfer the uneven shape.

For those who observe the protective film, the antireflection layer is a layer for weakening the reflection of external light on the surface of the protective film, and usually has a reflectance of visible light of 1.5% or less. An antireflection layer having such a reflectance is typically formed by laminating a high refractive index layer having a high refractive index and a low refractive index layer having a low refractive index, or as described in JP-A No. 2021-6929. By using the methods and materials described. By adjusting the refractive index and the thickness of each layer, the reflected light from each layer can be made to weaken each other, and an excellent antireflection function can be achieved.

The antireflection layer consisting of a high refractive index layer and a low refractive index layer is manufactured using a coating type composition that can form each of the high refractive index layer and the low refractive index layer, as detailed later. This is preferable because the operation is extremely simple. Here, an example of a coating type composition that can form each of a high refractive index layer and a low refractive index layer will be given. Such a coating type composition is in liquid form and contains an appropriate curable resin and, if necessary, additives. The coating type composition (coating liquid for forming a high refractive index layer) that can form a high refractive index layer includes, for example, a curable resin such as urethane acrylate, acetophenone type, benzophenone type, benzyl dimethyl ketal type, α-hydroxyalkyl It is made by dissolving a photopolymerization initiator (photopolymerization initiator) such as a phenone type, α-aminoalkylphenone type, or thioxanthone type in a solvent such as methyl ethyl ketone or methyl isobutyl ketone. In order to improve the applicability, a leveling agent, preferably a fluorine-based leveling agent, may be included. In addition, as a coating type composition capable of forming a low refractive index layer (coating liquid for forming a low refractive index layer), a binder such as polyethylene glycol diacrylate or pentaerythrium (tri/tetra) acrylate is used as a curable resin. An initiator for photopolymerization (photopolymerization initiator) such as acetophenone, benzophenone, benzyl dimethyl ketal, α-hydroxyalkylphenone, α-aminoalkylphenone, or thioxanthone is added to the resin, and 1-methoxy- It is made by dispersing silica particles in a solution dissolved in a solvent such as 2-propyl acetate or methyl isobutyl. In order to improve the coating properties, a fluorine leveling agent may be included. Note that the coating type compositions that can form each of the high refractive index layer and the low refractive index layer listed here are just examples, and depending on the characteristics of the antireflection layer to be formed, the composition for forming the high refractive index layer may be It is preferable to optimize each of the coating liquid and the coating liquid for forming a low refractive index layer.

The antireflection layer can include, for example, a low refractive index layer. Moreover, the multilayer structure may further include a high refractive index layer and/or a medium refractive index layer between the protective film and the low refractive index layer.

The low refractive index layer is formed by applying a coating liquid containing a cured product of the above-mentioned curable resin, a translucent resin such as a metal alkoxide polymer, and inorganic particles, and then curing the coating layer as necessary. It can be formed by a method. Examples of inorganic particles include LiF (refractive index 1.4), MgF (refractive index 1.4), 3NaF.AlF (refractive index 1.4), AlF (refractive index 1.4), Na ₃ AlF ₆ ( Examples include low refractive particles with a refractive index of 1.33) and hollow silica particles.

The antistatic layer is provided for the purpose of imparting conductivity to the surface of the protective film and suppressing the effects of static electricity. For forming the antistatic layer, for example, a method of applying a resin composition containing a conductive substance (antistatic agent) onto the protective film can be adopted. For example, an antistatic hard coat layer can be formed by allowing an antistatic agent to coexist in the hard coat material used for forming the above-mentioned hard coat layer.

The antifouling layer is provided to impart water repellency, oil repellency, sweat resistance, antifouling properties, and the like. A suitable material for forming the antifouling layer is a fluorine-containing organic compound. Examples of the fluorine-containing organic compound include fluorocarbon, perfluorosilane, and polymer compounds thereof. As a method for forming the antifouling layer, a physical vapor deposition method, typified by vapor deposition or sputtering, a chemical vapor deposition method, a wet coating method, etc. can be used depending on the material to be formed. The average thickness of the antifouling layer is usually about 1 to 50 nm, preferably 3 to 35 nm.

[First retardation plate]
The first retardation plate only needs to include a layer that exhibits a retardation, and the layer that exhibits a retardation may be a retardation film formed by stretching or the like from a thermoplastic resin film, or may be a retardation film formed by stretching or the like from a thermoplastic resin film. It may also be a layer (hereinafter also referred to as a "retardation film") that is made of a polymer in an oriented state of a liquid crystal compound and exhibits optical anisotropy. A film obtained by stretching a thermoplastic resin film is preferable from the viewpoint of scratch resistance, a cycloolefin polymer film and a triacetyl cellulose film are more preferable from the viewpoint of optical use, and a cycloolefin polymer film is more preferable from the viewpoint of versatility. preferable. When the first retardation plate is a stretched thermoplastic resin film, the thickness is preferably 10 μm to 100 μm, more preferably 15 μm to 80 μm from the viewpoint of layer thickness design of the optical laminate, More preferably, the thickness is 20 μm to 50 μm.
When the first retardation plate is a retardation film, the optical laminate may have a configuration in which the first protective film, which is a component of the linearly polarizing plate, also serves as the first retardation plate, and the linearly polarizing plate and the first protective film also serve as the first retardation plate. Alternatively, a configuration may be provided in which a first retardation plate is separately provided. When the first retardation plate has a retardation film, a polymerizable liquid crystal compound with positive dispersion is selected for the retardation film so as to exhibit the characteristic of positive dispersion (so as to satisfy formula (1)). Other than that, it can be obtained according to the method for forming the retardation layer of the second retardation plate, which will be described later.

The first retardation plate is arranged such that the angle θ1 of its slow axis with respect to the absorption axis of the polarizer is 40° to 50° or -40° to -50°, preferably about 45° or The angle is approximately -45°. If Re1(λ) is the in-plane retardation value of the first retardation plate for light having a wavelength of λnm, then the following formula (1) is satisfied, and preferably the following formula (1a) is also satisfied.
1.0≦Re1(450)/Re1(550) (1)
1.0≦Re1(550)/Re1(650) (1a)
(In the formula, Re1 (450) is the in-plane retardation value of the first retardation plate for light with a wavelength of 450 nm, Re1 (550) is the in-plane retardation value for light with a wavelength of 550 nm, and Re1 (650) is the wavelength (Represents the in-plane retardation value of the first retardation plate for 650 nm light.)

In the first retardation plate, Re1(λ) preferably satisfies the following formulas (4) and (5).
100nm≦Re1(450)≦130nm (4)
100nm≦Re1(550)≦130nm (5)

If the first retardation plate satisfies the above formulas (1) and (4), even if the displayed image is viewed through polarized sunglasses, the display image can be viewed regardless of the display angle. It is possible to provide an optical laminate that can constitute an image display device with reduced color difference. Although the retardation value is often designed based on light with a wavelength of 550 nm, it is considered important for solving the problem that the retardation value for light with a wavelength of 450 nm is within a predetermined range.
If "Re1 (450)/Re1 (550)" of the first retardation plate is less than 1.0, the difference in color tone depending on the display angle becomes large. Preferably, it is 1.00 or more and 1.3 or less, more preferably 1.02 or more and 1.2 or less, and still more preferably 1.03 or more and 1.1 or less. The value of "Re1 (450)/Re1 (550)" can be determined by adjusting the material of the retardation film, or by adjusting the mixing ratio of the polymerizable liquid crystal compound, the lamination angle of multiple optically anisotropic layers, and the retardation value. It is possible to adjust it arbitrarily by adjusting it.

When the layer expressing a retardation contained in the first retardation plate is a retardation film, the thickness thereof is preferably 0.5 to 5 μm, more preferably 0.8 to 4 μm, and still more preferably 1 to 3 μm. It is.

[Second retardation plate]
The second retardation plate includes a cured liquid crystal obtained by polymerizing a polymerizable liquid crystal compound, and includes two or more retardation layers that are retardation films exhibiting optical anisotropy. For example, when the second retardation plate includes two retardation layers, the second retardation plate is arranged such that the slow axes of these two retardation layers intersect with each other in the plane. When the second retardation plate includes three or more retardation layers, the slow axes of two of the three or more retardation layers are arranged to intersect with each other in a plane. It is preferable. The slow axes of all three or more retardation layers are arranged in different directions in the plane, that is, the retardation of any two of all the three or more retardation layers. It is also preferable that the slow axes of the layers intersect.
The second retardation plate satisfies the following equations (2) and (3), where Re2 (λ) is the in-plane retardation value of light with a wavelength of λ nm.
70nm≦Re2(450)≦130nm (2)
Re2(450)/Re2(550)≦1.0 (3)

In order to achieve a high degree of antireflection function, which is the objective of the present invention, the second retardation plate only needs to have a λ/4 layer function (i.e., a π/2 retardation function) in the entire visible light range. . Specifically, it may be a reverse wavelength dispersion λ/4 layer, and preferably a combination of a positive wavelength dispersion λ/2 layer and a positive wavelength dispersion λ/4 layer. Furthermore, from the viewpoint of compensating for the antireflection function in the oblique direction, it is preferable to further include a layer having anisotropy in the thickness direction (positive C plate). Furthermore, each optically anisotropic layer may have a tilt orientation or may form a cholesteric orientation state.

For example, the second retardation plate may have a configuration in which all of the retardation layers containing the cured liquid crystal are positive A plates, and the slow axes of the retardation layers intersect with each other within the plane. Furthermore, from the viewpoint of suppressing coloration of reflected light from an image display device observed from an oblique direction, the λ/2 layer is preferably a negative A plate.

<Retardation film>
A composition containing a polymerizable liquid crystal compound (hereinafter also referred to as "composition for forming a retardation film") is coated on a transparent substrate, and an optically anisotropic layer consisting of an oriented polymer of the polymerizable liquid crystal compound is formed. It is preferable to do so because it allows thinning and arbitrary design of wavelength dispersion characteristics. Moreover, the composition for forming a retardation film may further contain a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, and the like.

A retardation film is usually produced by applying a composition for forming a retardation film onto an alignment film formed on a base material and polymerizing a polymerizable liquid crystal compound contained in the composition for forming a retardation film. It is formed. A retardation film is usually a film that is cured with a polymerizable liquid crystal compound oriented.In order to generate a retardation within the viewing plane, the polymerizable liquid crystal compound must be oriented horizontally to the substrate surface. It is necessary that the film be a cured film in which the polymerizable groups are polymerized under the conditions. At this time, if the polymerizable liquid crystal compound is a rod-shaped liquid crystal, a positive A plate may be used, and if the polymerizable liquid crystal compound is a disk-shaped liquid crystal, a negative A plate may be used.

The thickness of the retardation film is usually 10 μm or less, preferably 5 μm or less, and more preferably 0.3 μm or more and 3 μm or less. Preferably, it is a coating layer formed by polymerizing one or more polymerizable liquid crystals.

[Configuration combining a positive wavelength dispersion λ/2 layer and a positive wavelength dispersion λ/4 layer]
As a second retardation plate, a configuration in which a positive wavelength dispersion λ/2 layer and a positive wavelength dispersion λ/4 layer are combined is known as one method for achieving antireflection performance. For example, the positive wavelength dispersion λ/2 layer is a negative A plate, and the positive wavelength dispersion λ/4 layer is a positive A plate. The slow axis of the positive wavelength dispersion λ/2 layer and the slow axis of the positive wavelength dispersion λ/4 layer may be arranged so as to intersect in the plane at an intersection angle of, for example, 50° to 70°. preferable. The crossing angle here means a narrow crossing angle among the crossing angles of two slow axes.

With respect to the absorption axis of the polarizer, the slow axis of the positive dispersion λ/2 layer is, for example, 10° to 20°, preferably 12° to 18°, more preferably about 15°, The slow axis of the positive dispersion λ/4 layer is, for example, 70° or more and 80° or less, more preferably 72° or more and 78° or less, and even more preferably about 75°.
In another embodiment, the slow axis of the positive dispersion λ/2 layer is, for example, -10° to -20°, preferably -12° to -18° with respect to the absorption axis of the polarizer, More preferably, it is about -15°, and the slow axis of the positive dispersion λ/4 layer is, for example, -70° to -80°, more preferably -72° to -78°, and even more preferably about -75°.
In yet another embodiment, the slow axis of the positive dispersion λ/2 layer is between 70° and 80° with respect to the absorption axis of the polarizer, preferably between 72° and 78°, more preferably about 75°, and the slow axis of the positive dispersion λ/4 layer is, for example, 10° to 20°, more preferably 12° to 18°, still more preferably about 15°.
In yet another embodiment, the slow axis of the positive dispersion λ/2 layer is -70° to -80°, preferably -72° to -78° with respect to the absorption axis of the polarizer, More preferably, it is about -75°, and the slow axis of the positive dispersion λ/4 layer is, for example, -10° to -20°, more preferably -12° to -18°, and even more preferably about -15°.

When the in-plane retardation value at wavelength λ is Re(λ), a layer having optical properties expressed by formulas (21), (23) and formula (24), and formulas (22) and (23) and a layer having optical properties expressed by formula (24) in a specific slow axis relationship.
100nm<Re(550)<150nm (21)
150nm<Re(550)<320nm (22)
Re(450)/Re(550)≧1.00 (23)
1.00≧Re(650)/Re(550) (24)

In formula (21), the preferred range of Re (550) is 100 nm to 150 nm, more preferably 105 nm to 145 nm, and even more preferably 110 nm to 140 nm. Further, in formula (22), the preferred range of Re (550) is 150 nm to 320 nm, more preferably 170 nm to 310 nm, and even more preferably 210 nm to 300 nm.

Examples of methods for combining the above configurations include well-known methods such as Japanese Patent Application Publication No. 2015-163935 and WO2013/137464. From the viewpoint of viewing angle compensation, it is preferable to use a λ/2 layer made of a disc-shaped polymerizable liquid crystal compound and a λ/4 layer made of a rod-shaped polymerizable liquid crystal compound.

［式（Ｗ）中、Ｒ^４０は、下記式（Ｗ－１）～（Ｗ－５）を表わす。 Examples of the disk-shaped polymerizable liquid crystal compound include a compound containing a group represented by formula (W) (hereinafter sometimes referred to as a polymerizable liquid crystal compound (C)).

[In formula (W), R ⁴⁰ represents the following formulas (W-1) to (W-5).

X ⁴⁰ and Z ⁴⁰ represent an alkanediyl group having 1 to 12 carbon atoms, and the hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms; The hydrogen atoms included may be substituted with halogen atoms. Furthermore, -CH ₂ - constituting the alkanediyl group may be replaced with -O- or -CO-.

Examples of the rod-shaped polymerizable liquid crystal include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V), or formula (VI).
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (I)
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (II)
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (III)
P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (IV)
P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (V)
P11-B11-E11-B12-A11-B13-A12-F11 (VI)
(In the formula, A12 to A14 are each independently synonymous with A11, B14 to B16 are each independently synonymous with B12, B17 is synonymous with B11, and E12 is synonymous with E11. F11 is a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (-SO ₃ H) represents a carboxyl group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and -CH ₂ - constituting the alkyl group and alkoxy group may be replaced with -O-. good.)

[Other configurations]
In addition to the configuration combining the positive wavelength dispersion λ/2 layer and the positive wavelength dispersion λ/4 layer, there are no particular restrictions on configurations with tilt orientation or cholesteric orientation as long as they achieve an antireflection function. , for example, well-known configurations such as WO2021/060378, WO2021/132616, and WO2021/132624.

The content of the polymerizable liquid crystal compound in the polymerizable liquid crystal composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, based on 100 parts by mass of the solid content of the polymerizable liquid crystal composition. The amount is preferably 85 to 98 parts by weight, and even more preferably 90 to 95 parts by weight. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of orientation of the resulting cured liquid crystal film. Note that in this specification, the solid content of the polymerizable liquid crystal composition means all components of the polymerizable liquid crystal composition excluding volatile components such as organic solvents.

The in-plane retardation value of the second retardation film can be adjusted by adjusting the thickness of the retardation film. Since the in-plane retardation value is determined by the following formula (8), in order to obtain the desired in-plane retardation value (Re2(λ)), it is sufficient to adjust Δn(λ) and the film thickness d. . The thickness of the retardation film is preferably 0.5 μm to 5 μm, more preferably 1 μm to 3 μm. The thickness of the retardation film can be measured using an interference film thickness meter, a laser microscope, or a stylus-type film thickness meter. Note that Δn(λ) depends on the molecular structure of the polymerizable liquid crystal compound described later.
Re2(λ)=d×Δn(λ)…(8)
(In the formula, Re2(λ) represents the in-plane retardation value at the wavelength λnm, d represents the film thickness, and Δn(λ) represents the birefringence at the wavelength λnm.)

<Base material>
Examples of the substrate include glass substrates and film substrates, with film substrates being preferred, and long roll-shaped films being more preferred since they can be produced continuously. Examples of resins constituting the film base material include polyolefins such as polyethylene, polypropylene, and norbornene polymers; cyclic olefin resins; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic esters; polyacrylic esters; triacetyl cellulose, diacetyl cellulose and cellulose esters such as cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyether sulfone; polyether ketone; and plastics such as polyphenylene sulfide and polyphenylene oxide. Among them, a film base material selected from triacetylcellulose, cyclic olefin resin, polymethacrylic acid ester, and polyethylene terephthalate is more preferable from the viewpoint of transparency when used in optical film applications.

Examples of commercially available cellulose ester base materials include "FujiTac Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY", and "KC4UY" (all manufactured by Konica Minolta Opto Co., Ltd.).
Commercially available cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona (Germany)), "Aton" (registered trademark) (manufactured by JSR Corporation), "ZEONOR" (registered trademark), Examples include "ZEONEX" (registered trademark) (manufactured by Nippon Zeon Co., Ltd.) and "APEL" (registered trademark) (manufactured by Mitsui Chemicals, Inc.). Such a cyclic olefin resin can be formed into a film by a known method such as a solvent casting method or a melt extrusion method to form a base material. A commercially available cyclic olefin resin base material can also be used. Commercially available cyclic olefin resin base materials include "S-Sina" (registered trademark), "SCA40" (registered trademark) (manufactured by Sekisui Chemical Co., Ltd.), and "Zeonor Film" (registered trademark) (manufactured by Optes Co., Ltd.). ) and "Arton Film" (registered trademark) (manufactured by JSR Corporation).

As for the thickness of the base material, it is preferable that the base material has a mass that can be handled practically, but if it is too thin, the strength tends to decrease and the workability tends to be poor. The thickness of the base material is usually 5 μm to 300 μm, preferably 10 μm to 200 μm, more preferably 10 to 50 μm. Furthermore, by peeling off the base material and transferring the polymer of the polymerizable liquid crystal compound containing the dichroic dye, it is possible to apply only the optically anisotropic layer of the present invention, resulting in further thinning effects. is obtained.

<Orientation film>
In this specification, the alignment film has an alignment regulating force that causes the polymerizable liquid crystal compound to align the liquid crystal in a desired direction.

The alignment film facilitates liquid crystal alignment of the polymerizable liquid crystal compound. The state of liquid crystal alignment, such as horizontal alignment, vertical alignment, hybrid alignment, and tilted alignment, changes depending on the properties of the alignment film and the polymerizable liquid crystal compound, and the combination thereof can be arbitrarily selected. For example, if the alignment film is a material that exhibits horizontal alignment as an alignment regulating force, the polymerizable liquid crystal compound can form horizontal alignment or hybrid alignment; if the alignment film is a material that exhibits vertical alignment, the polymerizable liquid crystal compound can form a vertical or tilted orientation. Expressions such as horizontal and vertical refer to the direction of the long axis of the oriented polymerizable liquid crystal compound with respect to the plane of the optically anisotropic layer. For example, vertical alignment means that the long axis of the polymerizable liquid crystal compound is aligned in a direction perpendicular to the plane of the optically anisotropic layer. Vertical here means 90°±20° with respect to the plane of the optically anisotropic layer.

If the alignment film is made of an oriented polymer, the alignment regulating force can be adjusted arbitrarily by changing the surface condition and rubbing conditions, and if it is made of a photo-alignable polymer, it can be adjusted by changing the polarized light irradiation conditions. It is possible to arbitrarily adjust it by etc. Moreover, liquid crystal alignment can also be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal compound.

The alignment film formed between the base material and the optically anisotropic layer is insoluble in the solvent used when forming the optically anisotropic layer on the alignment film, and is not soluble in solvent removal or liquid crystal. It is preferable that the material has heat resistance in the heat treatment for orientation. Examples of the alignment film include an alignment film made of an oriented polymer, a photo-alignment film, a groove alignment film, a stretched film stretched in the orientation direction, etc. When applied to a long roll-shaped film, A photo-alignment film is preferred because the orientation direction can be easily controlled.

The thickness of the alignment film is usually in the range of 10 nm to 5000 nm, preferably in the range of 10 nm to 1000 nm, and more preferably in the range of 30 to 300 nm.

The oriented polymers used in the rubbed alignment film include polyamides and gelatins having amide bonds in the molecule, polyimides having imide bonds in the molecule, polyamic acid which is a hydrolyzate thereof, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, Examples include polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic esters. Among them, polyvinyl alcohol is preferred. These oriented polymers may be used alone or in combination of two or more.

The rubbing method involves coating a substrate with an oriented polymer composition on a rotating rubbing roll wrapped with a rubbing cloth and annealing it to form an oriented polymer film on the surface of the substrate. An example is a method of contacting.

The photo-alignment film is made of a polymer, oligomer or monomer having a photo-reactive group. The photo-alignment film can obtain alignment regulating power by irradiating it with polarized light. A photo-alignment film is more preferable in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

The photoreactive group refers to a group that produces liquid crystal alignment ability when irradiated with light. Specifically, it is one that induces the orientation of molecules by irradiation with light, or that causes a photoreaction that is the origin of the liquid crystal alignment ability, such as an isomerization reaction, a dimerization reaction, a photocrosslinking reaction, or a photodecomposition reaction. be. Among the photoreactive groups, those that cause a dimerization reaction or a photocrosslinking reaction are preferred in terms of excellent orientation. The photoreactive group capable of causing the above reaction is preferably one having an unsaturated bond, especially a double bond, such as a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C More preferably, the group has at least one selected from the group consisting of a nitrogen-nitrogen double bond (N=N bond), and a carbon-oxygen double bond (C=O bond).

Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. A chalcone group and a cinnamoyl group are preferred from the viewpoint of easy control of reactivity and expression of alignment regulating force during photoalignment. Examples of the photoreactive group having a C=N bond include groups having structures such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N=N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and those having an azoxybenzene as a basic structure. Examples of the photoreactive group having a C═O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have substituents such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.

The polarized light may be irradiated by directly irradiating the polarized light from the film surface, or by irradiating the polarized light from the base material side and transmitting the polarized light. Moreover, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength range in which a polymer having a photoreactive group or a photoreactive group of a monomer can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in the range of 250 to 400 nm is particularly preferred. Examples of light sources used for polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF, with high-pressure mercury lamps, ultra-high pressure mercury lamps, and metal halide lamps being more preferable. These lamps are preferable because they emit a high intensity of ultraviolet light with a wavelength of 313 nm. Polarized light can be irradiated by passing the light from the light source through a suitable polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan-Thompson or Glan-Taylor, or a wire grid type polarizer can be used.

<Composition for forming optically anisotropic layer>
The composition for forming a polarizing film or the composition for forming a retardation film (hereinafter also referred to as the composition for forming an optically anisotropic layer) further contains a solvent, a leveling agent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, It may contain reactive additives such as crosslinking agents and adhesives, and preferably contains solvents and leveling agents from the viewpoint of processability.

<Solvent>
The composition for forming an optically anisotropic layer may contain a solvent. Generally, polymerizable liquid crystal compounds have a high viscosity, so it may be easier to apply the optically anisotropic layer forming composition by dissolving it in a solvent, and as a result, it may be easier to form the optically anisotropic layer. many. The solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound, and is also preferably a solvent that is inert to the polymerization reaction of the polymerizable liquid crystal compound.

Examples of solvents include alcoholic solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, and γ-butyrolactone. or ester solvents such as propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; toluene and aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile; ether solvents such as tetrahydrofuran and dimethoxyethane; chlorine-containing solvents such as chloroform and chlorobenzene; dimethylacetamide, dimethylformamide, N-methyl-2-pyrrolidone, Examples include amide solvents such as 1,3-dimethyl-2-imidazolidinone. These solvents may be used alone or in combination of two or more.

The content of the solvent is preferably 50 to 98% by mass based on the total amount of the composition for forming an optically anisotropic layer. In other words, the solid content in the composition for forming an optically anisotropic layer is preferably 2 to 50% by mass, more preferably 5 to 30% by mass. When the solid content is 50% by mass or less, the viscosity of the composition for forming an optically anisotropic layer becomes low. There is a tendency for unevenness to occur less easily in the anisotropic layer. Further, the solid content can be determined in consideration of the thickness of the optically anisotropic layer to be manufactured.

<Leveling agent>
The composition for forming an optically anisotropic layer may contain a leveling agent. A leveling agent is an additive that has the function of adjusting the fluidity of the composition and making the film obtained by applying the composition more flat, and examples include organically modified silicone oil, polyacrylate, and perfluorinated silicone oil. Examples include alkyl leveling agents. Among these, polyacrylate leveling agents and perfluoroalkyl leveling agents are preferred.

When the composition for forming an optically anisotropic layer contains a leveling agent, it is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound. Department. When the content of the leveling agent is within the above range, it is easy to horizontally align the polymerizable liquid crystal compound, and the resulting optically anisotropic layer tends to be smoother. When the content of the leveling agent in the polymerizable liquid crystal compound exceeds the above range, the resulting optically anisotropic layer tends to be uneven. In addition, the composition for forming an optically anisotropic layer may contain two or more types of leveling agents.

<Polymerization initiator>
The composition for forming an optically anisotropic layer may contain a polymerization initiator. The polymerization initiator is a compound that can initiate a polymerization reaction of a polymerizable liquid crystal compound or the like. As the polymerization initiator, a photopolymerization initiator that generates active radicals by the action of light is preferred from the viewpoint of not depending on the phase state of the thermotropic liquid crystal.

As the photopolymerization initiator, any known photopolymerization initiator can be used as long as it is a compound that can initiate the polymerization reaction of the polymerizable liquid crystal compound. Specifically, photopolymerization initiators that can generate active radicals or acids by the action of light can be mentioned, and among them, photopolymerization initiators that can generate radicals by the action of light are preferred. The photopolymerization initiators can be used alone or in combination of two or more.

As the photopolymerization initiator, a known photopolymerization initiator can be used. For example, as a photopolymerization initiator that generates active radicals, self-cleavable benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-Aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, azo compounds, etc. can be used, and hydrogen abstraction type benzophenone compounds, alkylphenone compounds, benzoin ether compounds, benzyl ketal compounds, dibenzo Suberone-based compounds, anthraquinone-based compounds, xanthone-based compounds, thioxanthone-based compounds, halogenoacetophenone-based compounds, dialkoxyacetophenone-based compounds, halogenobisimidazole-based compounds, halogenotriazine-based compounds, triazine-based compounds, etc. can be used. As the photopolymerization initiator that generates acid, iodonium salts, sulfonium salts, and the like can be used. From the viewpoint of excellent reaction efficiency at low temperatures, self-cleavable photopolymerization initiators are preferred, and acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, and oxime ester compounds are particularly preferred.

The content of the polymerization initiator in the composition for forming an optically anisotropic layer can be adjusted as appropriate depending on the type and amount of the polymerizable liquid crystal compound, but based on 100 parts by mass of the polymerizable liquid crystal compound, The amount is usually 0.1 to 30 parts by weight, preferably 0.5 to 10 parts by weight, and more preferably 0.5 to 8 parts by weight. When the content of the polymerization initiator is within the above range, polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal compound.

<Sensitizer>
The composition for forming an optically anisotropic layer may contain a sensitizer. As the sensitizer, a photosensitizer is preferred. Examples of the sensitizer include xanthone compounds such as xanthone and thioxanthone (for example, 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); anthracene such as anthracene and anthracene containing an alkoxy group (for example, dibutoxyanthracene, etc.); Compounds include phenothiazine and rubrene.

When the composition for forming an optically anisotropic layer contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the composition for forming an optically anisotropic layer can be further promoted. The amount of the sensitizer used is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 10 parts by weight, and 0.5 to 8 parts by weight based on 100 parts by weight of the polymerizable liquid crystal compound. Part is more preferable.

[Polymerization inhibitor]
From the viewpoint of stably advancing the polymerization reaction, the composition for forming an optically anisotropic layer may contain a polymerization inhibitor. The degree of progress of the polymerization reaction of the polymerizable liquid crystal compound can be controlled by the polymerization inhibitor.

Examples of the polymerization inhibitor include radicals such as hydroquinone, alkoxy group-containing hydroquinone, alkoxy group-containing catechol (such as butylcatechol), pyrogallol, and 2,2,6,6-tetramethyl-1-piperidinyloxy radical. Scavengers; thiophenols; β-naphthylamines, β-naphthols, and the like.

When the composition for forming an optically anisotropic layer contains a polymerization inhibitor, the content of the polymerization inhibitor is preferably 0.1 to 30 parts by mass, based on 100 parts by mass of the polymerizable liquid crystal compound. More preferably 0.5 to 10 parts by weight, still more preferably 0.5 to 8 parts by weight. When the content of the polymerization inhibitor is within the above range, polymerization can be carried out without disturbing the orientation of the polymerizable liquid crystal compound.

<Composition for forming an optically anisotropic layer; Reactive additive>
The composition for forming an optically anisotropic layer may contain a reactive additive. The reactive additive preferably has a carbon-carbon unsaturated bond or an active hydrogen-reactive group in its molecule. The term "active hydrogen-reactive group" as used herein refers to a group that is reactive with groups having active hydrogen, such as carboxyl group (-COOH), hydroxyl group (-OH), and amino group (-NH ₂ ). Representative examples thereof include a glycidyl group, an oxazoline group, a carbodiimide group, an aziridine group, an imide group, an isocyanate group, a thioisocyanate group, and a maleic anhydride group. The number of carbon-carbon unsaturated bonds and active hydrogen-reactive groups that the reactive additive has is usually 1 to 20 each, preferably 1 to 10 each.

The carbon-carbon unsaturated bond possessed by the reactive additive may be a carbon-carbon double bond, a carbon-carbon triple bond, or a combination thereof, and is preferably a carbon-carbon double bond. Among these, the reactive additive preferably contains a carbon-carbon unsaturated bond as a vinyl group and/or (meth)acrylic group. Furthermore, a reactive additive whose active hydrogen-reactive group is at least one selected from the group consisting of an epoxy group, a glycidyl group, and an isocyanate group is preferable, and a reactive additive having an acrylic group and an isocyanate group is more preferable. .

Since the light emitted from the OLED has polarization, when observing the emitted light from the OLED that passes through the second retardation plate, the polarizer, and the first retardation plate through sunglasses, the second retardation plate relative to the absorption axis of the polarizer What is the sign of the angle θ2 of the slow axis of the first layer of the retardation plate (the retardation layer closest to the polarizer) and the sign of the angle θ1 of the slow axis of the first retardation plate with respect to the absorption axis of the polarizer? , are preferably different from each other from the viewpoint of reducing the coloration of light observed through sunglasses. With this arrangement, the absorption axis of the first retardation plate and the absorption axis of the retardation layer (first layer) closest to the polarizer among the retardation layers constituting the second retardation plate are aligned. are arranged inverted about the absorption axis of the polarizer, so the phase difference is canceled and the coloring of the observed light is small.

The smaller the absolute value of the angle of the slow axis of the first layer of the second retardation plate (the retardation layer closest to the polarizer) with respect to the absorption axis of the polarizer, that is, the absorption axis and the slow axis are The closer parallelism is preferable from the viewpoint of reducing the reflectance when viewed from an oblique direction. Therefore, the angle of the slow axis of the first layer of the second retardation plate (the retardation layer closest to the polarizer) with respect to the absorption axis of the polarizer is between 10° and 20°, or between -10° and - Preferably, the angle is 20°. When the second retardation plate has a configuration that combines the positive wavelength dispersion λ/2 layer and the positive wavelength dispersion λ/4 layer illustrated above, the first layer is the positive wavelength dispersion λ/2 layer. Alternatively, it may be a positive wavelength dispersion λ/4 layer.

[First bonding layer, second bonding layer, third bonding layer, adhesive layer]
The first bonding layer 13, the second bonding layer 15, and the third bonding layer 17 in the optical laminate 1 are layers responsible for bonding two layers in the optical laminate 1, and the adhesive layer , or an adhesive layer can be used.

<Adhesive layer>
The adhesive layer is one form of the first bonding layer 13 , the second bonding layer 15 , the third bonding layer 17 , and the adhesive layer 19 . In addition to these layers, the adhesive layer can also be used as a bonding layer for two layers. As the adhesive composition forming the adhesive layer, conventionally known adhesive compositions having excellent optical transparency can be used without particular limitation, such as acrylic resins, urethane resins, silicone resins, An adhesive composition having a base polymer such as a polyvinyl ether resin can be used. Further, active energy ray-curable adhesive compositions, thermosetting adhesive compositions, etc. may be used. Among these, a pressure-sensitive adhesive composition using an acrylic resin as a base polymer, which is excellent in transparency, adhesive strength, removability, weather resistance, heat resistance, etc., is suitable.
The adhesive composition may further contain a crosslinking agent, a silane compound, an antistatic agent, and the like.

[(meth)acrylic resin]
The (meth)acrylic resin contained in the adhesive composition has a structural unit derived from a (meth)acrylic acid alkyl ester represented by the following formula (X) (hereinafter also referred to as "structural unit (X)"). A polymer (hereinafter also referred to as a "(meth)acrylic acid ester polymer") as a main component (for example, containing 50 parts by mass or more per 100 parts by mass of structural units of a (meth)acrylic resin). It is preferable.
In addition, in this specification, (meth)acrylic resin means that either an acrylic resin or a methacrylic resin may be sufficient, and "(meth)", such as (meth)acrylate, has the same meaning.

［式中、Ｒ^１０は、水素原子またはメチル基を表し、Ｒ^２０は、炭素数１～２０のアルキル基を表し、前記アルキル基は直鎖状、分岐状または環状のいずれの構造を有していてもよく、前記アルキル基の水素原子は、炭素数１～１０のアルコキシ基で置き換わっていてもよい。］

[In the formula, R ¹⁰ represents a hydrogen atom or a methyl group, R ²⁰ represents an alkyl group having 1 to 20 carbon atoms, and the alkyl group has a linear, branched, or cyclic structure. The hydrogen atom of the alkyl group may be replaced with an alkoxy group having 1 to 10 carbon atoms. ]

Examples of the (meth)acrylic ester represented by formula (X) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, and n-butyl. (meth)acrylate, i-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, i-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, i-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n- and i-nonyl (meth)acrylate, n-decyl (meth)acrylate, i-decyl (meth)acrylate, Examples include n-dodecyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, and t-butyl (meth)acrylate. Specific examples of the alkyl acrylate containing an alkoxy group include 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, and the like. Among these, n-butyl (meth)acrylate or 2-ethylhexyl (meth)acrylate is preferably included, and n-butyl (meth)acrylate is particularly preferably included.

The (meth)acrylic acid ester polymer may contain a structural unit derived from a monomer other than the structural unit (X). The number of structural units derived from other monomers may be one, or two or more. Other monomers that the (meth)acrylic acid ester polymer may contain include monomers having polar functional groups, monomers having aromatic groups, and acrylamide monomers.

Examples of the monomer having a polar functional group include (meth)acrylate having a polar functional group. Examples of the polar functional group include a hydroxy group; a carboxy group; a substituted or unsubstituted amino group substituted with an alkyl group having 1 to 6 carbon atoms; and a heterocyclic group such as an epoxy group.

The content of structural units derived from monomers having polar functional groups in the (meth)acrylic ester polymer is preferably 10 parts by mass based on 100 parts by mass of all structural units of the (meth)acrylic ester polymer. The amount is preferably 0.5 parts by weight or more and 10 parts by weight or less, still more preferably 0.5 parts by weight or more and 5 parts by weight or less, particularly preferably 1 part by weight or more and 5 parts by weight or less.

Monomers having an aromatic group include one (meth)acryloyl group and one or more aromatic rings (e.g., benzene ring, naphthalene ring, etc.) in the molecule, and include phenyl groups, phenoxyethyl groups, Alternatively, a (meth)acrylic acid ester having a benzyl group can be mentioned. By including these structural units, it is possible to suppress the white spot phenomenon that occurs in a polarizing plate in a high temperature and high humidity environment.

The content of structural units derived from monomers having an aromatic group in the (meth)acrylic ester polymer is preferably 20 parts by mass based on 100 parts by mass of all structural units of the (meth)acrylic ester polymer. It is not more than 4 parts by mass, more preferably not less than 4 parts by mass and not more than 20 parts by mass, and even more preferably not less than 4 parts by mass and not more than 15 parts by mass.

Examples of acrylamide monomers include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, and N-(2-methylpropoxymethyl)acrylamide. Examples include. By including these structural units, bleed-out of additives such as antistatic agents, which will be described later, can be suppressed.

Furthermore, structural units derived from other monomers other than structural unit (X) include structural units derived from styrene monomers, structural units derived from vinyl monomers, and ) A structural unit derived from a monomer having an acryloyl group, etc. may be included.

The weight average molecular weight (hereinafter also simply referred to as "Mw") of the (meth)acrylic resin (X) is preferably 500,000 to 2,500,000. When the weight average molecular weight is 500,000 or more, the durability of the first adhesive layer in a high temperature and high humidity environment can be improved. When the weight average molecular weight is 2,500,000 or less, the operability when applying a coating liquid containing the adhesive composition will be good. The molecular weight distribution (Mw/Mn) expressed as the ratio of weight average molecular weight (Mw) to number average molecular weight (hereinafter also simply referred to as "Mn") is usually 2 to 10. In this specification, "weight average molecular weight" and "number average molecular weight" are polystyrene equivalent values measured by gel permeation chromatography (GPC).

When the (meth)acrylic resin is dissolved in ethyl acetate to form a solution with a concentration of 20% by mass, the viscosity at 25°C is preferably 20 Pa・s or less, and 0.1 to 15 Pa・s. is more preferable. When the viscosity of the (meth)acrylic resin at 25° C. is within the above range, it contributes to improved durability and reworkability of the polarizing plate including the adhesive layer formed from the resin. The viscosity can be measured using a Brookfield viscometer.

The glass transition temperature (Tg) of the (meth)acrylic resin is, for example, -60 to 20°C, preferably -50 to 15°C, more preferably -45 to 10°C, and even more preferably -40 to 0°C. Note that the glass transition temperature can be measured using a differential scanning calorimeter (DSC).

The (meth)acrylic resin may contain two or more types of (meth)acrylic acid ester polymers. Such (meth)acrylic acid ester polymers include, for example, those whose main component is the structural unit (X) derived from the above-mentioned (meth)acrylic acid ester, and whose weight average molecular weight is from 50,000 to 300,000. Examples include (meth)acrylic acid ester polymers with relatively low molecular weights such as those in the range of .

(Meth)acrylic resins can be generally produced by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. In the production of (meth)acrylic resins, polymerization is usually carried out in the presence of a polymerization initiator. The amount of the polymerization initiator used is usually 0.001 to 5 parts by weight based on the total of 100 parts by weight of all monomers constituting the (meth)acrylic resin. (Meth)acrylic resins can also be produced by polymerization using active energy rays such as ultraviolet rays.

<Crosslinking agent>
It is preferable that the adhesive composition contains a crosslinking agent. Examples of the crosslinking agent include conventional crosslinking agents (for example, isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.), which particularly affect the pot life of the adhesive composition, the crosslinking rate, and the polarizing plate. From the viewpoint of durability, isocyanate compounds are preferred.

An isocyanate compound is a compound having at least two isocyanato groups (-NCO) in the molecule. Specific examples include tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and the like. Also included are adducts obtained by reacting these isocyanate compounds with polyols such as glycerol and trimethylolprone, and dimers and trimers of these isocyanate compounds. Two or more types of isocyanate compounds may be combined.

The proportion of the crosslinking agent is, for example, 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, and more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the (meth)acrylic resin. be.

<Silane compound>
The adhesive composition may further contain a silane compound.
Examples of silane compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyl Methyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyl Examples include trimethoxysilane and 3-mercaptopropyltrimethoxysilane.
Moreover, the silane compound can include an oligomer derived from the above-mentioned silane compound.

The content of the silane compound in the adhesive composition is usually 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, based on 100 parts by weight of the (meth)acrylic resin. When the content of the silane compound is 0.01 parts by mass or more, the adhesion between the adhesive layer and the adherend tends to improve, and when the content is 10 parts by mass or less, the adhesiveness from the adhesive layer tends to improve. Bleeding out of the silane compound tends to be suppressed.

<Antistatic agent>
The adhesive composition may further contain an antistatic agent. Known antistatic agents may be used, and ionic antistatic agents are preferred. The cation component constituting the ionic antistatic agent includes organic cations and inorganic cations. Examples of organic cations include pyridinium cations, imidazolium cations, ammonium cations, sulfonium cations, and phosphonium cations. 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. The anion component constituting the ionic antistatic agent may be either an inorganic anion or an organic anion, but an anion component containing a fluorine atom is preferable because it has excellent antistatic performance. Examples of anion components containing a fluorine atom include hexafluorophosphate anion (PF ₆ ⁻ ), bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N ⁻ ], and bis(fluorosulfonyl)imide anion [(FSO ₂ ) ₂ N ⁻ ] anion and the like.
Ionic antistatic agents that are solid at room temperature are preferred because the antistatic performance of the pressure-sensitive adhesive composition has excellent stability over time.
The content of the antistatic agent is, for example, 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, and more preferably 1 to 7 parts by weight, based on 100 parts by weight of the (meth)acrylic resin. .

The adhesive composition can contain one or more additives such as a UV absorber, a solvent, a crosslinking catalyst, a tackifying resin (tackifier), and a plasticizer. It is also useful to add an ultraviolet curable compound to the adhesive composition, form an adhesive layer, and then cure it by irradiating it with ultraviolet rays to form a harder adhesive layer.

The adhesive layer can be formed by, for example, dissolving or dispersing the adhesive composition in a solvent to obtain a solvent-containing adhesive composition, and then applying this to the surface of the layer on which the adhesive layer is to be provided and drying it. It can be formed by

The thickness of the adhesive layer is usually 0.1 to 30 μm, preferably 3 to 30 μm, and more preferably 5 to 25 μm.

[Adhesive layer]
The adhesive layer is one form of the first bonding layer 13, the second bonding layer 15, and the third bonding layer 17. In addition to these layers, the adhesive layer can also be used as a bonding layer for two layers. Examples of the adhesive composition include water-based adhesive compositions, curable adhesive compositions that are cured by heating or irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. Examples of water-based adhesive compositions include those in which a polyvinyl alcohol-based resin or urethane resin is dissolved in water as the main component, and those in which a polyvinyl alcohol-based resin or urethane resin is dispersed in water as the main component. The water-based adhesive composition may further contain a curable component such as a polyhydric aldehyde, a melamine compound, a zirconia compound, a zinc compound, a glyoxal compound, a water-soluble epoxy resin, and a crosslinking agent. Examples of the water-based adhesive composition include the adhesive composition described in JP-A No. 2010-191389, the adhesive composition described in JP-A No. 2011-107686, and the adhesive composition described in JP-A No. 2020-172088. Examples include compositions described in JP-A No. 2005-208456.

The curable adhesive composition is preferably an active energy ray-curable adhesive composition that contains a curable (polymerizable) compound as a main component and is cured by irradiation with active energy rays. Active energy ray-curable adhesive compositions include cationically polymerizable adhesive compositions containing a cationic polymerizable compound as a curable compound, radically polymerizable adhesive compositions containing a radically polymerizable compound as a curable compound, and curable adhesive compositions. Examples of the compound include a hybrid adhesive composition containing both a cationically polymerizable compound and a radically polymerizable compound.

A cationically polymerizable compound is a compound or oligomer that undergoes a cationic polymerization reaction and is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays or by heating, and specifically includes epoxy compounds and oxetane compounds. , vinyl compounds, etc.
Epoxy compounds include alicyclic epoxy compounds (compounds having one or more epoxy groups bonded to an alicyclic ring in the molecule) such as 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate; bisphenol A Aromatic epoxy compounds (compounds having an aromatic ring and an epoxy group in the molecule) such as diglycidyl ether; aliphatic epoxy compounds (compounds having an aromatic ring and an epoxy group in the molecule) such as 2-ethylhexyl glycidyl ether and 1,4-butanediol diglycidyl ether; Examples include compounds having at least one oxirane ring bonded to a carbon atom in the molecule.
Examples of oxetane compounds include compounds having one or more oxetane rings in the molecule, such as 3-ethyl-3-{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane.
The cationic polymerization type adhesive composition preferably contains a cationic polymerization initiator. The cationic polymerization initiator may be a thermal cationic polymerization initiator or a photocationic polymerization initiator. Examples of cationic polymerization initiators include aromatic diazonium salts such as benzenediazonium hexafluoroantimonate; aromatic iodonium salts such as diphenyliodonium tetrakis(pentafluorophenyl)borate; aromatic sulfonium salts such as triphenylsulfonium hexafluorophosphate; xylene -Cyclopentadienyl iron (II) Iron-arene complexes such as hexafluoroantimonate and the like can be mentioned. The content of the cationic polymerization initiator is usually 0.1 to 10 parts by weight per 100 parts by weight of the cationically polymerizable compound. Two or more types of cationic polymerization initiators may be included.
Examples of the cationically polymerizable adhesive composition include cationically polymerizable compositions described in JP2016-126345A, WO2019/10315A, and JP2021-113969A.

A radically polymerizable compound is a compound or oligomer that undergoes a radical polymerization reaction and is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, or X-rays, or by heating. Examples include compounds having the following. Examples of the compound having an ethylenically unsaturated bond include (meth)acrylic compounds having one or more (meth)acryloyl groups in the molecule, vinyl compounds having one or more vinyl groups in the molecule, and the like.
(Meth)acrylic compounds are obtained by reacting two or more types of (meth)acrylate monomers having at least one (meth)acryloyloxy group in the molecule, (meth)acrylamide monomers, and functional group-containing compounds. Examples include (meth)acryloyl group-containing compounds such as (meth)acrylic oligomers having at least two (meth)acryloyl groups in the molecule.
It is preferable that the radical polymerization type adhesive composition contains a radical polymerization initiator. The radical polymerization initiator may be a thermal radical polymerization initiator or a photoradical polymerization initiator. Examples of radical polymerization initiators include acetophenone initiators such as acetophenone and 3-methylacetophenone; benzophenone initiators such as benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; benzoin propyl ether, benzoin ethyl ether, etc. Examples include benzoin ether initiators; thioxanthone initiators such as 4-isopropylthioxanthone; xanthone, fluorenone, and the like. The content of the radical polymerization initiator is usually 0.1 to 10 parts by mass based on 100 parts by mass of the radically polymerizable compound. Two or more types of radical polymerization initiators may be included.
Examples of the radically polymerizable adhesive composition include radically polymerizable compositions described in JP-A No. 2016-126345, JP-A No. 2016-153474, and International Publication No. 2017/183335.

The active energy ray-curable adhesive composition may contain an ion trapping agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, an antifoaming agent, It may contain additives such as antistatic agents, leveling agents, and solvents.

In laminating two layers using an adhesive layer, an adhesive composition is applied to at least one lamination surface selected from the lamination surfaces of each of the two layers, and the two layers are bonded together through the coated layer of the adhesive composition. After lamination by pressing from above and below using a laminating roll or the like, the adhesive layer may be dried, cured by irradiation with active energy rays, or cured by heating.
Before forming the coating layer of the adhesive layer, at least one of the bonding surfaces of the two layers is subjected to easy treatment such as saponification treatment, corona treatment, plasma treatment, primer treatment, anchor coating treatment, etc. Adhesion treatment may also be applied.
Various coating methods such as a die coater, comma coater, gravure coater, wire bar coater, doctor blade coater, etc. can be used to form the coating layer of the adhesive composition.

The light irradiation intensity when irradiating active energy rays is determined depending on the composition of the active energy ray-curable adhesive composition and is not particularly limited, but is 10 mW/cm ² or more and 1,000 mW/cm ² or less. It is preferable that Note that the irradiation intensity is preferably an intensity in a wavelength range effective for activating a photocationic polymerization initiator or a photoradical polymerization initiator. It is preferable to irradiate at such a light irradiation intensity once or multiple times to make the cumulative light amount 10 mJ/cm ² or more, more preferably 100 mJ/cm ² or more and 1,000 mJ/cm ^{2 or} less. .
The light source used to polymerize and cure the active energy ray-curable adhesive composition is not particularly limited, but includes, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, and a chemical lamp. , black light lamps, microwave-excited mercury lamps, and metal halide lamps.

The thickness of the adhesive layer formed from the water-based adhesive composition may be, for example, 5 μm or less, preferably 1 μm or less, more preferably 0.5 μm or less, and 0.01 μm or more. The thickness is preferably 0.05 μm or more.
The thickness of the adhesive layer formed from the active energy ray-curable adhesive composition may be, for example, 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less, and 0.1 μm or more. It is preferable that it is 0.5 μm or more, and more preferably 1 μm or more.

[Other layers that the optical laminate may have]
Preferably, the optical laminate includes a layer having predetermined ultraviolet absorption properties. The predetermined ultraviolet absorption characteristic is a characteristic that satisfies the relationships of the following formulas (5), (6), and (7), where Tr (λ) is the transmittance of light with a wavelength of λ nm.
Tr(450)≧85% (5)
30%≦Tr(420)≦75% (6)
0%≦Tr(400)≦10% (7)
By providing a layer having predetermined ultraviolet absorption characteristics, coloring of transmitted light can be suppressed.

The layer having predetermined ultraviolet absorption characteristics may be provided at any position in the optical laminate. For example, the above-mentioned surface treatment layer provided on the viewing side surface of the first protective film has the above formula (5). , (6), and (7).

One form of a layer having predetermined ultraviolet absorption characteristics suitable for satisfying the above formulas (5), (6), and (7) will be described.

で表される化合物（ＸI）を紫外線吸収剤として含む。 According to one embodiment, the layer with predetermined UV absorption properties comprises a UV absorber. For example, the following formula (XI):

It contains a compound (XI) represented by as an ultraviolet absorber.

In the above formula (XI), A represents a methylene group, a secondary amino group, an oxygen atom or a sulfur atom. A preferably represents a methylene group, a secondary amino group, or an oxygen atom from the viewpoint of exhibiting high photoselective absorption.

In the above formula (XI), R ¹ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. R ¹ represents an alkyl group preferably having 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and even more preferably 1 to 3 carbon atoms, from the viewpoint of exhibiting high photoselective absorption. Here, when the alkyl group has at least one methylene group, at least one of the methylene groups may be substituted with an oxygen atom or a sulfur atom. Examples of such alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, n-hexyl group, n-octyl group, n-decyl group, methoxy group, and ethoxy group. group, and isopropoxy group.

In the above formula (XI), R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. R ² and R ³ are each independently preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, from the viewpoint of exhibiting high photoselective absorption. represents a group, more preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, particularly preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

In the above formula (XI), R ⁴ is an alkyl group having 3 to 50 carbon atoms, or an alkyl group having 3 to 50 carbon atoms having at least one methylene group, and at least one of the methylene groups is attached to an oxygen atom. Represents a substituted alkyl group.

The alkyl group having 3 to 50 carbon atoms in R ⁴ preferably has 8 to 45 carbon atoms (for example, 10 to 45), more preferably 12-40, even more preferably 13-35, particularly preferably 14-30. Note that a substituent may be bonded to the carbon atom on the alkyl group.

The alkyl group having 3 to 50 carbon atoms and having at least one methylene group in R ⁴ preferably has a carbon number of It represents an alkyl group of 3 to 40, more preferably 4 to 35, particularly preferably 5 to 30. Here, in the alkyl group having 3 to 50 carbon atoms and having at least one methylene group, at least one of the methylene groups is substituted with an oxygen atom, such as ethoxy group, propoxy group, 2-methoxyethoxymethyl Examples include groups. Also included are polyethylene glycol groups such as diethylene glycol group and triethylene glycol group, and polypropylene glycols such as dipropylene glycol group and tripropylene glycol group.

Furthermore, a substituent may be bonded to the carbon atom on the alkyl group of ^R4 . Examples of substituents include halogen atoms, alkyl groups having 1 to 6 carbon atoms, cyano groups, nitro groups, alkylsulfinyl groups having 1 to 6 carbon atoms, alkylsulfonyl groups having 1 to 6 carbon atoms, carboxyl groups, and 1 to 6 carbon atoms. -6 fluoroalkyl group, C1-6 alkoxy group, C1-6 alkylthio group, C1-6 N-alkylamino group, C2-12 N,N-dialkylamino group , an N-alkylsulfamoyl group having 1 to 6 carbon atoms, an N,N-dialkylsulfamoyl group having 2 to 12 carbon atoms, and the like.

When R ⁴ is an alkyl group having 3 to 50 carbon atoms, from the viewpoint of affinity with hydrophobic substances and solubility in hydrophobic solvents, R ⁴ is an alkyl group having a branched structure having 3 to 12 carbon atoms. More preferably, it is an alkyl group having a branched structure having 6 to 10 carbon atoms.

Here, the alkyl group having a branched structure refers to an alkyl group in which at least one carbon atom is a tertiary carbon or a quaternary carbon. Specific examples of alkyl groups having a branched structure having 3 to 12 carbon atoms include alkyl groups having the following structure.

＊は連結部を表す。

* represents a connecting part.

In the above formula (XI), X ¹ represents an electron-withdrawing group. From the viewpoint of improving photoselective absorption, X ¹ is -NO ₂ , -CN, -COR ⁸ , -COOR ⁹ , -OR ¹⁰ , halogen atom (-F, -Cl, -Br, -I), -CSR ¹¹ , -CSOR ¹² , or -CSNR ¹³ are preferable, a nitro group, a cyano group, or -COOR ⁹ is more preferable, and a cyano group or -COOR ⁹ is even more preferable. Here, R ⁸ , R ⁹ , R ¹⁰ , R ¹¹ , R ¹² and R ¹³ each independently represent a hydrogen atom, a C 1-6 alkyl group, for example a C 2-5 alkyl group, or a phenyl group. represent.

In the above formula (XI), Y ¹ is -CO-, -COO-, -OCO-, -O-, -S-, -NR ⁵ -, -NR ⁶ CO-, -CONR ⁷ -, or -CS- and from the viewpoint of improving photoselective absorption, preferably represents -CO-, -COO-, -OCO-, or -O-, more preferably -CO-, -COO-, or -OCO- represent. Here, R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, for example an alkyl group having 2 to 5 carbon atoms, or a phenyl group.

で表されることが、種々の溶媒への溶解性及び／又は種々の化合物との親和性に優れる観点から好ましい。 In a preferred embodiment of the present invention, the compound (XI) represented by the above formula (XI) is the following formula (XI-I):

The following is preferable from the viewpoint of excellent solubility in various solvents and/or excellent affinity with various compounds.

In the above formula (XI-I), R ^4-1 represents an alkyl group having 1 to 6 carbon atoms, preferably an alkyl group having 2 to 5 carbon atoms, and more preferably an alkyl group having 3 to 4 carbon atoms.
n is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 6, for example 1 to 6, from the viewpoint of excellent solubility in various solvents and/or affinity with various compounds. Represents an integer of 4, especially an integer of 1 to 3. In addition, when n is within the above range, the light absorption per 1 part by mass will improve, and even if the compound (XI) contained in the member constituting the optical laminate is small, it will not have the blue light cutting function. In addition, for example, when the compound (XI) is contained in an adhesive, its adhesive function is hardly inhibited, and when the compound (XI) is contained in a protective film, the optical function as a protective film is not inhibited. Hard to inhibit.
A, R ¹ , R ² and R ³ are the same as in the above formula (XI).

で表されることがより好ましい。上記式（ＸI－I）で表される化合物が上記式（ＸI－II）で表される化合物であると、種々の溶媒への溶解性及び／又は種々の化合物との親和性に優れるため、該化合物を溶媒に均一に溶解させることが容易となり、また同時に、種々の化合物との親和性にも優れ、両親媒性を示すため、光学積層体を構成する部材に該化合物を含ませた場合にブリードアウトを生じにくく、安定して光吸収機能を発揮させることができる。 In a more preferred embodiment of the present invention, the compound represented by the above formula (XI-I) is the compound represented by the following formula (XI-II):

It is more preferable to express it as follows. When the compound represented by the above formula (XI-I) is a compound represented by the above formula (XI-II), it has excellent solubility in various solvents and/or affinity with various compounds, This compound can be easily dissolved uniformly in a solvent, and at the same time has excellent affinity with various compounds and exhibits amphiphilic properties. It is difficult to cause bleed-out and can stably exhibit its light absorption function.

In formula (XI-II), R ^4-1 and n are the same as in formula (XI-I).

[Image display device]
The image display device includes an optical laminate and an image display element (such as an organic EL display element). The optical laminate is placed on the viewing side of the image display element. Using the adhesive layer 19, the optical laminate 1 can be bonded to an image display element.

The image display device is not particularly limited, and examples thereof include image display devices such as an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, and an electroluminescent display device.

Image display devices can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signboards, measuring instruments or instruments, office equipment, medical equipment, computer equipment, and the like.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The amounts expressed in "%" and "parts" in Examples and Comparative Examples are mass % and parts by mass, unless otherwise specified.

[Preparation of optical laminate]
Optical laminates of Examples and Comparative Examples having the configurations shown in FIG. 1 were produced. In the configuration shown in FIG. 1, the first protective film with a surface treatment layer (a laminate of the surface treatment layer 11 and the first protective film 12) and the second retardation plate 18 are selected for each example and each comparative example. The other components, that is, the first bonding layer 13, the polarizer 14, the second bonding layer 15, the second protective film 16, the third bonding layer 17, and the adhesive layer 19 are all The same one was adopted in the Examples and Comparative Examples.

[Measurement of phase difference value]
The retardation values of the first protective film and the second retardation plate were measured using a retardation measuring device (KOBRA-WPR manufactured by Oji Scientific Instruments Co., Ltd.).

[Measurement of transmittance]
The transmittance of the surface-treated layer of the first protective film with a surface-treated layer was determined by cutting the first protective film with a surface-treated layer into a size of 30 mm x 30 mm, and using an ultraviolet-visible spectrophotometer "UV-" manufactured by Shimadzu Corporation. The transmittance [%] was measured in the wavelength range of 200 to 800 nm using "2450".

[1] First Protective Film The following first protective films 1a to 5a were prepared as the first protective film.
(1) First protective film 1a
A cycloolefin film (manufactured by Nippon Zeon Co., Ltd., trade name "ZF-14", glass transition temperature 140°C) was prepared. The prepared film was uniaxially stretched at 140° C., and the stretching ratio was adjusted to obtain the following retardation value to obtain a first protective film 1a. The obtained stretched film had retardation values of Re1 (450) = 105 nm and Re1 (550) = 100 nm, and had a slow axis in the stretching direction.

(2) First protective film 2a
The stretching conditions used to obtain the stretched film of the first protective film 1a were changed and adjusted to the following retardation value to obtain the first protective film 2a. The obtained stretched film had retardation values of Re1 (450) = 127 nm and Re1 (550) = 121 nm, and had a slow axis in the stretching direction.

(3) First protective film 3a
The stretching conditions used to obtain the stretched film of the first protective film 1a were changed and adjusted to the following retardation value to obtain the first protective film 4a. The obtained stretched film had retardation values of Re1 (450) = 147 nm and Re1 (550) = 140 nm, and had a slow axis in the stretching direction.

(4) First protective film 4a
A cycloolefin film (manufactured by Nippon Zeon Co., Ltd., trade name "ZF-14") was prepared. After applying the polymerizable liquid crystal compound described in JP-A-2015-163935 on the prepared cycloolefin film at a ratio adjusted to have the retardation value shown below, the polymerizable liquid crystal compound is polymerized to obtain a position. A retardation film was formed to obtain a first protective film 5a. The obtained first protective film 5a had retardation values of Re1 (450) = 119 nm and Re1 (550) = 140 nm.

(5) First protective film 5a
A cycloolefin film (manufactured by Nippon Zeon Co., Ltd., trade name "ZF-14") was prepared. This film was used as the first protective film. The first protective film had retardation values of Re1(450)=0 nm and Re1(550)=0 nm.

[2] First protective film with surface treatment layer On the first protective film obtained above, a surface treatment layer was formed using the following surface treatment layer composition to obtain a first protective film with surface treatment layer. Ta. The combinations and evaluation results are shown in Table 3. The first protective film with a surface treatment layer was cut so that the slow axis was at 45° or −45° with respect to the longitudinal direction of the rectangle and used in an optical laminate.

(Surface treatment layer composition A)
As surface treatment layer composition A, 20 parts of EBECRYL4858 (manufactured by Daicel Allnex Corporation), 0.21 parts of Irgacure-184 (manufactured by BASF Japan Ltd.), and 26 parts of cyclopentanone (manufactured by Kanto Chemical Co., Ltd.). , and 24 parts of N-methyl-2-pyrrolidone (manufactured by Kanto Kagaku Co., Ltd.) were mixed and stirred at room temperature for 2 hours to obtain a homogeneous solution, which was used.

(Formation of surface treatment layer)
On the first protective film, the above-mentioned surface treatment layer composition A was applied using a wire bar so that the film thickness after curing was 5 μm to form a coating film. The solvent is evaporated by passing dry air at 70°C for 30 seconds at a flow rate of 0.5 m/s over the formed coating film, and ultraviolet rays are emitted to a cumulative light intensity of 200 mJ/cm in a nitrogen atmosphere (oxygen concentration 200 ppm or less). A surface treatment layer was formed by irradiating and curing the layer at a rate of ² . The surface treatment layer had a transmittance Tr(450) of 100% for light at a wavelength of 450 nm, a transmittance Tr(420) for light at a wavelength of 420 nm of 100%, and a transmittance Tr(400) for a wavelength of 400 nm of 100%. .

(Surface treatment layer composition B)
As surface treatment layer composition B, 20 parts of EBECRYL4858 (manufactured by Daicel Allnex Corporation), 0.80 part of UVA-01 synthesized in Synthesis Example 1, and 0.21 part of Irgacure-184 (manufactured by BASF Japan Ltd.) were used. 1, 26 parts of cyclopentanone (manufactured by Kanto Kagaku Co., Ltd.), and 24 parts of N-methyl-2-pyrrolidone (manufactured by Kanto Kagaku Co., Ltd.) and stirred at room temperature for 2 hours to form a homogeneous solution. I obtained this and used it.

(Synthesis example 1)

A 200 mL four-neck flask equipped with a Dimroth condenser and a thermometer was set in a nitrogen atmosphere, and 10 g of compound UVA-M-02 powder synthesized with reference to patent document (JP 2014-194508), acetic anhydride (Wako Pure Chemical Industries, Ltd.) 3.7 g (manufactured by Kogyo Co., Ltd.), 5.8 g of 2-ethoxyethyl cyanoacetate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 60 g of acetonitrile (manufactured by Wako Pure Chemical Industries, Ltd.) were charged and stirred with a magnetic stirrer. did. At an internal temperature of 25°C, 4.7 g of N,N-diisopropylethylamine (hereinafter abbreviated as DIPEA, manufactured by Tokyo Kasei Kogyo Co., Ltd.) was added dropwise from a dropping funnel over an hour, and after the addition was completed, at an internal temperature of 25°C. The mixture was kept warm for an additional 2 hours. After the reaction was completed, acetonitrile was removed using a reduced pressure evaporator, toluene was added to the resulting oil, and the resulting insoluble components were removed by filtration. The filtrate was concentrated again using a reduced pressure evaporator, the concentrated solution was purified by column chromatography (silica gel), and the desired product was obtained by recrystallization from toluene. By drying the crystals under reduced pressure at 60° C., 5.2 g of compound UVA-01 was obtained as a yellow powder. The yield was 65%. In addition, when the absorption maximum wavelength (λmax) was measured using a spectrophotometer UV-3150 (manufactured by Shimadzu Corporation), λmax = 389 nm (in 2-butanone), and ε (400) was 125 L/(g・cm), ε(420)/ε(400) was 0.0153.
When ¹ H-NMR analysis was performed, the following peaks were observed, which confirmed that compound UVA-01 was produced.
¹ H-NMR (CDCl ₃ ) δ: 1.21 (t, 3H), 2.10 (quIn. 2H), 2.98-3.04 (m, 5H), 3.54-3.72 (m , 6H), 4.31 (t, 2H), 5.53 (d, 2H), 7.93 (d, 2H)

(Formation of surface treatment layer)
On the first protective film, the above-mentioned surface treatment layer composition B was applied using a wire bar so that the film thickness after curing was 5 μm to form a coating film. The solvent is evaporated by passing dry air at 70°C for 30 seconds at a flow rate of 0.5 m/s over the formed coating film, and ultraviolet rays are emitted to a cumulative light intensity of 200 mJ/cm in a nitrogen atmosphere (oxygen concentration 200 ppm or less). A surface treatment layer was formed by irradiating and curing the layer at a rate of ² . The surface treatment layer had a transmittance Tr(450) of 90% for light with a wavelength of 450 nm, a transmittance Tr(420) of 50% for light with a wavelength of 420 nm, and a transmittance Tr(400) of 0% for a wavelength of 400 nm. .

(Surface treatment layer composition C)
As composition C for surface treatment layer, 20 parts of EBECRYL4858 (manufactured by Daicel Allnex Corporation), 0.80 part of UVA-02 represented by the following chemical formula (1-1-2), and Irgacure-184 (manufactured by BASF Japan) were used. (manufactured by Kanto Kagaku Co., Ltd.), 26 parts of cyclopentanone (manufactured by Kanto Kagaku Co., Ltd.), and 24 parts of N-methyl-2-pyrrolidone (manufactured by Kanto Kagaku Co., Ltd.) were mixed, and the mixture was heated at room temperature for 2 hours. A homogeneous solution was obtained by stirring and used.

(UVA-02)

(Formation of surface treatment layer)
On the first protective film, the above-mentioned surface treatment layer composition C was applied using a wire bar so that the film thickness after curing was 5 μm to form a coating film. The solvent is evaporated by passing dry air at 70°C for 30 seconds at a flow rate of 0.5 m/s over the formed coating film, and ultraviolet rays are emitted to a cumulative light intensity of 200 mJ/cm in a nitrogen atmosphere (oxygen concentration 200 ppm or less). A surface treatment layer was formed by irradiating and curing the layer at a rate of ² . The surface treatment layer had a transmittance Tr(450) of 49% for light with a wavelength of 450 nm, a transmittance Tr(420) of 18% for light with a wavelength of 420 nm, and a transmittance Tr(400) of 6% for a wavelength of 400 nm. .

[3] Second retardation plate (second retardation plate 1b)
<Preparation of first layer 1b>
[Preparation of photoalignable polymer composition (1)]
A photoalignable material with the following structure (weight average molecular weight: 50000, m:n=50:50) was produced according to the method described in JP-A-2021-196514. The photoalignable polymer composition (1) is prepared by mixing 2 parts of the photoalignable material and 98 parts of propylene glycol monomethyl ether (PGME, solvent) as components, and stirring the resulting mixture at 80°C for 1 hour. Prepared.
Photoalignable material:

重合性液晶化合物（Ａ２）：

[Manufacture of polymerizable liquid crystal compound]
A polymerizable liquid crystal compound (A1) and a polymerizable liquid crystal compound (A2) having the structures shown below were respectively prepared. The polymerizable liquid crystal compound (A1) and the polymerizable liquid crystal compound (A2) were prepared in the same manner as described in JP-A-2010-244038.
Polymerizable liquid crystal compound (A1):

Polymerizable liquid crystal compound (A2):

[Preparation of retardation film forming composition (Y1)]
A polymerizable liquid crystal compound (A1) and a polymerizable liquid crystal compound (A2) were mixed at a mass ratio of 80:20 to obtain a mixture. To 100 parts of the obtained mixture, 0.1 part of the leveling agent "Megafac F-556" (manufactured by DIC) and 2.5 parts of the photopolymerization initiator "Omnirad 907" (manufactured by IGM Resin B.V.) 1 part and 0.1 part of ionic compound (B) were added. Further, propylene glycol monomethyl ether acetate (PEGMEA) was added, and the mixture was stirred at a temperature of 80° C. for 1 hour to prepare a composition for forming a retardation film (Y1). The ionic compound (B) has a structure represented by the following formula.

イオン性化合物（Ｂ）

Ionic compound (B)

The photoalignable polymer composition (1) was applied to a triacetyl cellulose film (TAC) (KC4UY, manufactured by Konica Minolta, Inc.) cut into a rectangle. The obtained coating film was dried at 120° C. for 2 minutes, and then cooled to room temperature to form a dry film. Further, using a UV irradiation device, 100 mJ of polarized ultraviolet light (313 nm standard) was continuously irradiated at −15° with respect to the longitudinal direction of the TAC to form a 100 nm photo-alignment film. The composition for forming a retardation film (Y1) was applied thereon using a bar coater. The obtained coating film was dried at 100° C. for 1 minute, and then cooled to room temperature to obtain a dry film. Next, the dry film is continuously irradiated with ultraviolet light at an exposure dose of 1000 mJ/cm ² (365 nm standard) in a nitrogen atmosphere using a high-pressure mercury lamp, so that the polymerizable liquid crystal compound is spread within the plane of the substrate. It was cured in a horizontally oriented state. In this way, the first layer 1b consisting of TAC/alignment film/(λ/2 layer) was obtained. The thickness of the obtained λ/2 layer was measured using a laser microscope and was found to be 1.8 μm. The in-plane phase difference value was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. As a result, the in-plane retardation value at a wavelength of 550 nm was Re(550)=270 nm, and the in-plane retardation value at a wavelength of 450 nm was Re(450)=291 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. The orientation angle was −15° with respect to the longitudinal direction of the TAC.

<Preparation of second layer 1b>
Water was added to commercially available polyvinyl alcohol (Polyvinyl Alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.). The mixed solution was heated at 100° C. for 1 hour to obtain an oriented polymer composition.
The following table shows the polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan), the leveling agent "BYK-361N" (manufactured by BYK-Chemie), and the photopolymerization initiator "Omnirad 907" (manufactured by IGM Resin B.V.). The mixture was mixed in such a manner that the amount of the mixture was 2. Additionally, propylene glycol 1-monomethyl ether 2-acetate (PGME) was added. A composition for forming a retardation plate (Y2) was prepared by stirring this mixture at a temperature of 80° C. for 1 hour.

重合性液晶化合物ＬＣ２４２：

矩形に切り出したトリアセチルセルロースフィルム（ＴＡＣ）（コニカミノルタ株式会社製、ＫＣ４ＵＹ）に配向性ポリマー組成物を塗布した。塗膜を加熱乾燥し、厚さ１００ｎｍの配向性ポリマーの膜を形成した。得られた配向性ポリマーの膜の表面に前記ＴＡＣの長手方向から７５°となる角度でラビング処理を施し、配向膜を形成した。配向膜の上に、位相差板形成用組成物（Ｙ２）を、バーコーターにより塗布した。得られた塗膜を１００℃で１分間乾燥した後、室温まで冷却して乾燥被膜を得た。次いで、高圧水銀ランプ（ウシオ電機株式会社製「ユニキュアＶＢ－１５２０１ＢＹ－Ａ」）を用いて、窒素雰囲気下にて露光量１０００ｍＪ／ｃｍ^２（３６５ｎｍ基準）の紫外光を前記乾燥被膜に照射し、重合性液晶化合物を基材面内に対して水平方向に配向した状態で硬化させた。このようにして、ＴＡＣ／配向膜／（λ／４層）からなる第２層１ｂを得た。得られたλ／４層の膜厚をレーザー顕微鏡で測定したところ１．０μｍであった。面内位相差値は、王子計測機器株式会社製のＫＯＢＲＡ－ＷＲを用いて測定した。その結果、波長５５０ｎｍにおける面内位相差値はＲｅ（５５０）＝１４２ｎｍであり、波長４５０ｎｍにおける面内位相差値はＲｅ（４５０）＝１５３．４ｎｍであった。なお、ＴＡＣの波長５５０ｎｍにおける位相差値は略０であるため、当該光学特性には影響しない。配向角は前記ＴＡＣの長手方向に対して７５°であった。

Polymerizable liquid crystal compound LC242:

The oriented polymer composition was applied to a triacetyl cellulose film (TAC) (KC4UY, manufactured by Konica Minolta, Inc.) cut into a rectangular shape. The coating film was dried by heating to form an oriented polymer film with a thickness of 100 nm. The surface of the obtained oriented polymer film was rubbed at an angle of 75° from the longitudinal direction of the TAC to form an oriented film. The composition for forming a retardation plate (Y2) was applied onto the alignment film using a bar coater. The resulting coating film was dried at 100° C. for 1 minute, and then cooled to room temperature to obtain a dry film. Next, using a high-pressure mercury lamp (Unicure VB-15201BY-A manufactured by Ushio Inc.), the dried film was irradiated with ultraviolet light at an exposure dose of 1000 mJ/cm ² (365 nm standard) in a nitrogen atmosphere, The polymerizable liquid crystal compound was cured while being oriented in the horizontal direction with respect to the plane of the base material. In this way, a second layer 1b consisting of TAC/alignment film/(λ/4 layer) was obtained. The thickness of the obtained λ/4 layer was measured using a laser microscope and was found to be 1.0 μm. The in-plane phase difference value was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. As a result, the in-plane retardation value at a wavelength of 550 nm was Re (550) = 142 nm, and the in-plane retardation value at a wavelength of 450 nm was Re (450) = 153.4 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. The orientation angle was 75° with respect to the longitudinal direction of the TAC.

After corona treatment is applied to the retardation film side of the base material/alignment film/(λ/2 layer) which is the first layer 1b and the base material/alignment film/(λ/4 layer) which is the second layer 1b. , the respective substrates are laminated via an adhesive layer (acrylic adhesive layer) so that their longitudinal directions are in the same direction, and the following structure is formed: base material/alignment film/(λ/2 layers)/adhesive layer/( A λ/4 layer)/alignment film/substrate was obtained. Regarding the second retardation plate 1b, the apparent in-plane retardation value Re2 (550) at a wavelength of 550 nm was 139 nm, and the apparent in-plane retardation value Re2 (450) at a wavelength of 450 nm was 106 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. When viewed from the λ/2 layer side, the orientation angle was 15° for the λ/2 layer and 75° for the λ/4 layer with respect to the longitudinal direction of the TAC.

(Second retardation plate 2b)
<Preparation of first layer 2b>
The first layer 3b was produced under the same conditions as the first layer 1b except that the orientation direction of the photo-alignment film of the first layer 1b was set at 15° with respect to the longitudinal direction of the TAC. The thickness of the obtained λ/2 layer was measured using a laser microscope and was found to be 1.8 μm. The in-plane phase difference value was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. As a result, the in-plane retardation value at a wavelength of 550 nm was Re(550)=270 nm, and the in-plane retardation value at a wavelength of 450 nm was Re(450)=291 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. The orientation angle was 15° with respect to the longitudinal direction of the TAC.

<Preparation of second layer 2b>
The second layer 2b was produced under the same conditions as the second layer 1b except that the angle of the rubbing treatment of the second layer 1b was set to -75° with respect to the longitudinal direction of the TAC. The in-plane retardation value at a wavelength of 550 nm was Re (550) = 142 nm, and the in-plane retardation value at a wavelength of 450 nm was Re (450) = 153.4 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. The orientation angle was −75° with respect to the longitudinal direction of the TAC.

After corona treatment is applied to the retardation film side of the base material/alignment film/(λ/2 layer) which is the first layer 2b and the base material/alignment film/(λ/4 layer) which is the second layer 2b. , the respective substrates are laminated via an adhesive layer (acrylic adhesive layer) so that their longitudinal directions are in the same direction, and the following structure is formed: base material/alignment film/(λ/2 layers)/adhesive layer/( A λ/4 layer)/alignment film/substrate was obtained. Regarding the second retardation plate 2b, the apparent in-plane retardation value Re2 (550) at a wavelength of 550 nm was 139 nm, and the apparent in-plane retardation value Re2 (450) at a wavelength of 450 nm was 106 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. When viewed from the λ/2 layer side, the orientation angle was −15° for the λ/2 layer and −75° for the λ/4 layer with respect to the longitudinal direction of the TAC.

(Second retardation plate 3b)
<Preparation of first layer 3b>
The first layer 3b was produced under the same conditions as the first layer 1b, except that the orientation direction of the photo-alignment film of the first layer 1b was -75° with respect to the longitudinal direction of the TAC. The thickness of the obtained λ/2 layer was measured using a laser microscope and was found to be 1.8 μm. The in-plane phase difference value was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. As a result, the in-plane retardation value at a wavelength of 550 nm was Re(550)=270 nm, and the in-plane retardation value at a wavelength of 450 nm was Re(450)=291 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. The orientation angle was −75° with respect to the longitudinal direction of the TAC.

<Preparation of second layer 3b>
The second layer 3b was produced under the same conditions as the second layer 1b except that the angle of the rubbing treatment of the second layer 1b was 15° with respect to the longitudinal direction of the TAC. The in-plane retardation value at a wavelength of 550 nm was Re (550) = 142 nm, and the in-plane retardation value at a wavelength of 450 nm was Re (450) = 153.4 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. The orientation angle was 15° with respect to the longitudinal direction of the TAC.

After corona treatment is applied to the retardation film side of the base material/alignment film/(λ/2 layer) which is the first layer 3b and the base material/alignment film/(λ/4 layer) which is the second layer 3b. , the respective substrates are laminated via an adhesive layer (acrylic adhesive layer) so that their longitudinal directions are in the same direction, and the following structure is formed: base material/alignment film/(λ/2 layers)/adhesive layer/( A λ/4 layer)/alignment film/substrate was obtained. Regarding the second retardation plate 3b, the apparent in-plane retardation value Re2 (550) at a wavelength of 550 nm was 139 nm, and the apparent in-plane retardation value Re2 (450) at a wavelength of 450 nm was 106 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. When viewed from the λ/2 layer side, the orientation angle was 75° for the λ/2 layer and 15° for the λ/4 layer with respect to the longitudinal direction of the TAC.

(Second retardation plate 4b)
<Preparation of first layer 4b>
The first layer 4b was produced under the same conditions as the first layer 1b, except that the orientation direction of the photo-alignment film of the first layer 1b was 75° with respect to the longitudinal direction of the TAC. The thickness of the obtained λ/2 layer was measured using a laser microscope and was found to be 1.8 μm. The in-plane phase difference value was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. As a result, the in-plane retardation value at a wavelength of 550 nm was Re(550)=270 nm, and the in-plane retardation value at a wavelength of 450 nm was Re(450)=291 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. The orientation angle was 75° with respect to the longitudinal direction of the TAC.

<Preparation of second layer 4b>
The second layer 4b was produced under the same conditions as the second layer 1b except that the angle of the rubbing treatment of the second layer 1b was −15° with respect to the longitudinal direction of the TAC. The in-plane retardation value at a wavelength of 550 nm was Re (550) = 142 nm, and the in-plane retardation value at a wavelength of 450 nm was Re (450) = 153.4 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. The orientation angle was −15° with respect to the longitudinal direction of the TAC.

After corona treatment is applied to the retardation film side of the base material/alignment film/(λ/2 layer) which is the first layer 4b and the base material/alignment film/(λ/4 layer) which is the second layer 4b. , the respective substrates are laminated via an adhesive layer (acrylic adhesive layer) so that their longitudinal directions are in the same direction, and the following structure is formed: base material/alignment film/(λ/2 layers)/adhesive layer/( A λ/4 layer)/alignment film/substrate was obtained. Regarding the second retardation plate 4b, the apparent in-plane retardation value Re2 (550) at a wavelength of 550 nm was 139 nm, and the apparent in-plane retardation value Re2 (450) at a wavelength of 450 nm was 106 nm. Note that since the retardation value of TAC at a wavelength of 550 nm is approximately 0, it does not affect the optical characteristics. When viewed from the λ/2 layer side, the orientation angle was -75° for the λ/2 layer and -15° for the λ/4 layer with respect to the longitudinal direction of the TAC.

[4] Adhesive layer As the third bonding layer 17 and the adhesive layer 19, an acrylic adhesive layer with a thickness of 25 μm, both sides of which are bonded to a release film (storage modulus at 23° C.: 1.3 MPa) was used.

[5] Polarizer A polyvinyl alcohol film with a thickness of 20 μm, a degree of polymerization of 2400, and a degree of saponification of 99% or more is uniaxially stretched on a hot roll at a stretching ratio of 4.5 times, and while maintaining the tension state, 100 parts by mass of water is added. It was immersed for 60 seconds in a 28°C dyeing bath containing 0.05 parts by mass of iodine and 5 parts by mass of potassium iodide.

Next, it was immersed for 110 seconds in a 64° C. boric acid aqueous solution 1 containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water. Next, it was immersed for 30 seconds in a 67° C. boric acid aqueous solution 2 containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water. Thereafter, it was washed with pure water at 10°C and dried to obtain a polarizer. The thickness of the polarizer was 8 μm, and the boron content was 4.3% by mass.

[6] Preparation of optical laminates (Examples 1 to 12, Comparative Examples 1 to 3) A second protective film (triacetyl cellulose, thickness 20 μm), and a first protective film with a surface treatment layer (for Comparative Example 1, the first protective film without a surface treatment layer) using a water-based adhesive (first lamination layer 13) on the other surface, Lamination was carried out using a roll lamination machine. After lamination, drying treatment was performed at 80° C. for 3 minutes. A linear polarizing plate 10 in which protective films were laminated on both sides of a polarizer 14 was obtained. The linear polarizing plate 10 has a surface treatment layer 11, a first protective film 12, a first laminating layer 13, a polarizer 14, a second laminating layer 15, and a second protective film 16 laminated in this order. Ta. Table 3 shows the angle θ1 between the slow axis of the first protective film and the absorption axis of the polarizer in this laminate. In each example, the surface treatment layer composition used to form the surface treatment layer, the first protective film used for the first retardation plate, and the second retardation plate are shown in Table 3.

After cutting out the linearly polarizing plate 10 into a rectangle so that the longitudinal direction is the absorption axis of PVA, a pressure-sensitive adhesive layer (third laminating layer 17) is placed on the surface of the second protective film 16 of the linearly polarizing plate 10. , the base material is peeled off from the first layer side of the second retardation plate 18, the second retardation plate 18 is bonded so that the first layer side is located on the linear polarizing plate 10 side, and then the second retardation plate 18 is attached. The base material was peeled off from the second layer side of the plate 18, and the adhesive layer 19 was bonded to the peeled surface to obtain the optical laminate 1. In the optical laminate 1, the second retardation plates 18 are second retardation plates 1b to 4b as shown in Table 3. Table 3 shows the angle θ2 between the slow axis of the first layer and the absorption axis of the polarizer of the linear polarizing plate 10 in the optical laminate 1.

[7] Evaluation Each optical laminate 1 was bonded to an organic EL display element via the adhesive layer 19 to produce an organic EL display device.

(1) Transmitted light observation The appearance of the white display was observed through polarized sunglasses by setting the organic EL display device to display white and changing the display angle. During observation, we also observed whether there was a difference in the color tone or visibility of images viewed in portrait mode and landscape mode. The above observation results were evaluated based on the following criteria. Table 3 shows the results. Table 3 shows the color observed in portrait display and the color observed in landscape display as (color observed in portrait display/color observed in landscape display).

A: There was no difference in the appearance of the white display no matter what viewing angle it was observed at.
B: There was a slight difference in the appearance of white display depending on the display angle.
C: I felt that there was a difference in the appearance of white display depending on the display angle.
D: There was a difference in appearance of white display depending on the display angle, and there were display angles where the display became black.

(2) Observation of reflected light The organic EL display device was set to black display, and the display angle was changed to observe the appearance of the black display through polarized sunglasses. Furthermore, during the observation, the color tone of the visually recognized image was also observed. The above observation results were evaluated based on the following criteria. Table 3 shows the results. In Table 3, when a color other than black was observed, that color is also shown.
A: There was no difference in appearance of black display at any viewing angle.
B: There was a slight difference in the appearance of black display depending on the display angle.
C: I noticed a difference in the appearance of black display depending on the display angle.

(3) Oblique observation of transmitted light The organic EL display device was set to display white, and the coloration of the white display from an oblique direction (elevation angle of 60°, azimuth angle range of 0 to 360°) was observed through polarized sunglasses. The observation results were evaluated based on the following criteria, and the results are shown in Table 3.
A: No color change was felt in the white display.
B: Slight discoloration was felt in the white display.
C: Coloring was felt in the white display.

(4) Oblique Observation of Reflected Light The organic EL display device was set to black display, and the coloring of the black display from an oblique direction (elevation angle 60°, azimuth angle range 0 to 360°) was observed through polarized sunglasses. The observation results were evaluated based on the following criteria, and the results are shown in Table 3.
A: I did not notice any difference in the coloring of the black display.
B: Slight discoloration was felt in the black display.
C: Coloring was felt in the black display.

1 Optical laminate, 11 Surface treatment layer, 12 First protective film, 13 First bonding layer, 14 Polarizer, 15 Second bonding layer, 16 Second protective film, 17 Third bonding layer, 18 Second Retardation plate, 19 adhesive layer.

Claims (8)

having a first retardation plate, a polarizer, a second retardation plate, and an adhesive layer in this order,
The first retardation plate is
It is arranged so that the angle θ1 of its slow axis with respect to the absorption axis of the polarizer is 40° to 50° or -40° to -50°, and has an in-plane retardation value for light with a wavelength of λ nm. When Re1(λ), the following formula (1) is satisfied,
The second retardation plate is
Containing two or more retardation layers containing a cured liquid crystal obtained by polymerizing a polymerizable liquid crystal compound,
At least two of the two or more retardation layers have slow axes that intersect with each other in the plane,
An optical laminate that satisfies the relationships of formulas (2) and (3) below, where Re2 (λ) is the in-plane retardation value for light with a wavelength of λ nm.
1.0≦Re1(450)/Re1(550) (1)
70nm≦Re2(450)≦130nm (2)
Re2(450)/Re2(550)≦1.0 (3) The optical laminate according to claim 1, wherein the first retardation plate is a stretched thermoplastic resin film and has a thickness of 10 μm to 100 μm. The optical laminate according to claim 1 or 2, wherein in the first retardation plate, the Re1(λ) satisfies the following formulas (4) and (5).
100nm≦Re1(450)≦130nm (4)
100nm≦Re1(550)≦130nm (5) further comprising a protective film disposed between the polarizer and the second retardation plate,
The optical laminate according to claim 1, wherein the protective film has an in-plane retardation value of 0 nm to 20 nm for light with a wavelength of 550 nm. The optical laminate according to claim 1 or 2, wherein slow axes of at least two of the retardation layers constituting the second retardation plate intersect in a plane. Among the two or more retardation layers constituting the second retardation plate, the first layer, which is the layer closest to the polarizer, has an angle θ2 of its slow axis with respect to the absorption axis of the polarizer. The optical laminate according to claim 1 or 2, wherein the angle is 10° to 20° or -10° to -20°. Among the two or more retardation layers constituting the second retardation plate, the first layer, which is the layer closest to the polarizer, has an angle θ2 between its slow axis and the absorption axis of the polarizer. The optical laminate according to claim 1 or 2, wherein the sign of the angle θ1 is opposite to the sign of the angle θ1. further comprising a layer having predetermined ultraviolet absorption characteristics on the surface of the first retardation plate opposite to the polarizer;
2. The predetermined ultraviolet absorption characteristic is a characteristic that satisfies the following equations (6), (7), and (8), where Tr (λ) is the transmittance of light with a wavelength of λ nm. The optical laminate described in.
Tr(450)≧85% (6)
30%≦Tr(420)≦75% (7)
0%≦Tr(400)≦10% (8)

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