JP2024018330A - optical laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical laminate which comprises a liquid crystal polarizer formed using a polymerizable liquid crystal compound and a liquid crystal retardation layer, and offers superior wet heat durability.

SOLUTION: An optical laminate is provided, comprising a protective layer, liquid crystal polarizer, first bonding layer, first liquid crystal retardation layer, second bonding layer, second liquid crystal retardation layer, and third bonding layer arranged in the described order. The liquid crystal polarizer includes a cured product layer of a first liquid crystal composition containing a dichroic dye and a polymerizable liquid crystal compound. The first bonding layer is a cured product layer of an active energy-curable composition. Each of the first and second liquid crystal retardation layers includes a cured product layer of a second liquid crystal composition containing a polymerizable liquid crystal compound. The second and third bonding layers have glass transition temperatures of 25°C or less.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to an optical laminate.

As an organic EL display device, a flexible display device whose display screen can be folded or rolled is known. In order to suppress reflection of external light, an organic EL display device uses a circularly polarizing plate in which a polarizing element and a retardation element are laminated. Circularly polarizing plates applied to flexible display devices are required to reduce deterioration of optical properties at bent portions and to make cracks less likely to occur due to bending (for example, Patent Document 1, etc.).

International Publication No. 2016/158300

When the circularly polarizing plate is made thinner, the thickness of the organic EL display device can be reduced, and the bendability of the organic EL display device can be easily improved. Therefore, it is possible to make the circularly polarizing plate thinner by using a liquid crystal polarizer and a liquid crystal retardation layer formed using a liquid crystal compound instead of a resin film as the polarizing element and retardation element constituting the circularly polarizing plate. be. However, when a circularly polarizing plate including a liquid crystal polarizer and a liquid crystal retardation layer is exposed to a humid heat environment, island-like unevenness (shading) may be visually recognized on the circularly polarizing plate.

An object of the present invention is to realize excellent wet heat durability in an optical laminate including a liquid crystal polarizer and a liquid crystal retardation layer formed using a polymerizable liquid crystal compound.

The present invention provides the following optical laminate.
[1] An optical laminate including a protective layer, a liquid crystal polarizer, a first bonding layer, a first liquid crystal retardation layer, a second bonding layer, a second liquid crystal retardation layer, and a third bonding layer in this order. There it is,
The liquid crystal polarizer includes a cured layer of a first liquid crystal composition containing a dichroic dye and a polymerizable liquid crystal compound,
The first liquid crystal retardation layer and the second liquid crystal retardation layer both include a cured layer of a second liquid crystal composition containing a polymerizable liquid crystal compound,
The first bonding layer is a cured product layer of an active energy ray-curable composition,
The optical laminate, wherein the second bonding layer and the third bonding layer both have a glass transition temperature of 25° C. or lower.
[2] The optical laminate according to [1], wherein the first bonding layer is a cured layer of a radically polymerizable adhesive composition.
[3] The thickness of the protective layer, the liquid crystal polarizer, the first liquid crystal retardation layer, and the second liquid crystal retardation layer is all less than 20.0 μm, according to [1] or [2]. optical laminate.
[4] The distance from the surface of the protective layer opposite to the liquid crystal polarizer side to the surface of the third bonding layer opposite to the second liquid crystal retardation layer side is defined as D1 [μm]. and when,
The optical laminate according to any one of [1] to [3], wherein the total thickness D2 [μm] of the second bonding layer and the third bonding layer is 40% or more and 70% or less of D1.
[5] The optical laminate according to any one of [1] to [4], further comprising an overcoat layer (second protective layer) that covers the surface of the liquid crystal polarizer on the first bonding layer side.

According to the present invention, it is possible to provide an optical laminate that includes a liquid crystal polarizer and a liquid crystal retardation layer formed using a polymerizable liquid crystal compound and has excellent wet heat durability.

FIG. 1 is a cross-sectional view schematically showing an example of an optical laminate according to an embodiment of the present invention. It is a schematic diagram explaining the method of the flexibility test of an example. FIG. 2 is a schematic perspective view schematically showing an end face processing device used in an example.

Hereinafter, preferred embodiments of the optical laminate will be described with reference to the drawings.
(optical laminate)
FIG. 1 is a cross-sectional view schematically showing an example of an optical laminate according to an embodiment of the present invention. As shown in FIG. 1, the optical laminate 1 includes a protective layer 11, a liquid crystal polarizer 15, a first bonding layer 31, a first liquid crystal retardation layer 21, a second bonding layer 32, a second liquid crystal retardation layer 22 and a third bonding layer 33 in this order. The optical laminate 1 may further include an overcoat layer (second protective layer) 18 that covers the surface of the liquid crystal polarizer 15 on the first bonding layer 31 side. In the optical laminate 1, when the overcoat layer 18 is not included, the protective layer 11 and the liquid crystal polarizer 15 constitute the polarizing plate 10, and when the overcoat layer 18 is included, the protective layer 11, the liquid crystal polarizer 15, and the overcoat layer 18 constitute the polarizing plate 10. The coating layer 18 can constitute the polarizing plate 10. The polarizing plate has a function of absorbing polarized light components parallel to the absorption axis and transmitting polarized light components perpendicular to the absorption axis. A separator 38 that can be peeled off from the third bonding layer 33 may be attached to the side of the third bonding layer 33 of the optical laminate 1 opposite to the second liquid crystal retardation layer 22 side. The optical laminate 1 and the separator 38 constitute an optical laminate with a separator.

In the optical laminate 1, the first bonding layer 31 is in direct contact with the polarizing plate 10 and the first liquid crystal retardation layer 21, and the second bonding layer 32 is in direct contact with the first liquid crystal retardation layer 21 and the second liquid crystal retardation layer. It is preferable that the third bonding layer 33 is in direct contact with the second liquid crystal retardation layer 22 . The first bonding layer 31 may be in direct contact with the liquid crystal polarizer 15 that constitutes the polarizing plate 10, or may be in direct contact with the overcoat layer 18 that constitutes the polarizing plate 10. In the polarizing plate 10, it is preferable that the protective layer 11 and the liquid crystal polarizer 15 are in direct contact with each other, and it is preferable that the liquid crystal polarizer 15 and the overcoat layer 18 are in direct contact with each other.

The protective layer 11 can constitute the outermost surface on the viewing side of the optical laminate 1, and can cover and protect the surface of the liquid crystal polarizer 15. The surface of the protective layer 11 opposite to the liquid crystal polarizer 15 side is usually covered with a removable surface protection film (protective film) for the surface of the protective layer 11 that is exposed to the atmosphere. or covered with an adhesive layer with a thickness of 50 μm or more for bonding the front panel. In other words, the protective layer 11 is a layer existing in the range from the surface of the liquid crystal polarizer 15 on the protective layer 11 side to the above-mentioned surface of the protective layer 11 .

The protective layer 11 may have a single layer structure or a multilayer structure. Preferably, the protective layer 11 includes a resin layer. The protective layer 11 may include, for example, a part or all of a first base layer (described later) to which a first liquid crystal composition (described later) for forming the liquid crystal polarizer 15 is applied. Details of the protective layer 11 will be described later.

The liquid crystal polarizer 15 includes a cured layer of a first liquid crystal composition containing a dichroic dye and a polymerizable liquid crystal compound. Since the liquid crystal polarizer 15 is a cured layer of the first liquid crystal composition, the thickness of the liquid crystal polarizer 15 can be made smaller than that of a polarizer in which a dichroic dye is adsorbed and aligned on a polyvinyl alcohol resin film. Therefore, the optical laminate 1 can be made thinner. The liquid crystal polarizer 15 may have a single layer structure consisting only of the above-mentioned cured material layer, and in addition to the above-mentioned cured material layer, a polymerizable liquid crystal compound (described later) contained in the first liquid crystal composition may be used. It may have a multilayer structure including a first alignment film for alignment. Details of the liquid crystal polarizer 15 will be described later.

The first liquid crystal retardation layer 21 and the second liquid crystal retardation layer 22 both include a cured layer of a second liquid crystal composition containing a polymerizable liquid crystal compound. Since the first liquid crystal retardation layer 21 and the second liquid crystal retardation layer 22 are cured layers of the second liquid crystal composition, the first liquid crystal retardation layer 21 Also, since the thickness of the second liquid crystal retardation layer 22 can be reduced, the optical laminate 1 can be made thinner. The first liquid crystal retardation layer 21 and the second liquid crystal retardation layer 22 may have a single layer structure consisting only of the above-mentioned cured material layer, and in addition to the above-mentioned cured material layer, a polymerizable liquid crystal compound may be used. It may have a multilayer structure including a second alignment film for alignment. The first liquid crystal retardation layer 21 and the second liquid crystal retardation layer 22 may include cured layers formed from the same second liquid crystal composition, or may include cured layers formed from different second liquid crystal compositions. It may contain layers.

The first bonding layer 31 is a cured product layer of an active energy ray-curable composition. In the optical laminate 1, the liquid crystal polarizer 15 is a cured layer of the first liquid crystal composition, and the first liquid crystal retardation layer 21 and the second liquid crystal retardation layer 22 are cured layers of the second liquid crystal composition. . Therefore, the thicknesses of the liquid crystal polarizer 15, the first liquid crystal retardation layer 21, and the second liquid crystal retardation layer 22 can be reduced, and the optical laminate 1 can be made thinner.

Since the first bonding layer 31 is a cured layer of an active energy ray-curable composition, when the optical laminate 1 is exposed to a moist heat environment, the transmittance of transmitted light parallel to the transmission axis direction is reduced. Since it is possible to suppress the decrease in the optical density, it is possible to suppress visible island-like unevenness (shading) in the optical laminate 1. The reason for this is thought to be as follows. The cured product layer of the active energy ray-curable composition has a higher crosslinking density than the bonding layer (hereinafter also referred to as "adhesive layer") having a glass transition temperature of 25° C. or lower. Therefore, in the cured product layer of the active energy ray-curable composition, compared to the adhesive layer, the dichroic dye contained in the liquid crystal polarizer 15 is present on the first liquid crystal retardation layer 21 side of the liquid crystal polarizer 15. It is easy to prevent the dichroic dye from diffusing into the layers, and it is possible to prevent the orientation of the dichroic dye from being disordered within the optical laminate 1. As described above, in the optical laminate 1 in which the first bonding layer 31 is a cured layer of an active energy ray-curable composition, the decrease in transmittance can be suppressed when exposed to a moist heat environment. Thereby, it is possible to suppress visible island-like unevenness (shading) in the optical laminate 1 and provide an optical laminate 1 with excellent wet heat durability.

By using a cured product layer of an active energy ray-curable composition as the first bonding layer 31, scratches when the optical laminate 1 is subjected to external force can be reduced compared to the case where an adhesive layer is used. You can also make it less likely to remain. In particular, when the thickness of the protective layer 11 of the optical laminate 1 is small (for example, 15 μm or less), the first bonding layer 31 is composed of an active energy ray-curable composition to make the optical laminate 1 less likely to be scratched. Preferably, the layer is a cured product layer.

The active energy ray-curable composition for forming the first bonding layer 31 is preferably a radically polymerizable adhesive composition. That is, the first bonding layer 31 is preferably a cured product layer of a radically polymerizable adhesive composition. The radically polymerizable adhesive composition forms a crosslinked structure through a curing reaction and increases its hardness quickly, and can form a cured material layer having sufficient hardness immediately after irradiation with active energy rays. On the other hand, since the curing reaction of cationic polymerizable adhesive compositions proceeds gradually, uncured components remain immediately after irradiation with active energy rays, and compared to the cured layer of radically polymerizable adhesive compositions, It tends to be difficult to obtain a cured material layer having sufficient hardness immediately after irradiation with active energy rays. Therefore, compared to the cured layer of a cationic polymerizable adhesive composition, the cured layer of the radically polymerizable adhesive composition is less likely to deform due to external force immediately after curing, and the optical laminate 1 It is thought that it is possible to prevent foreign matter from leaving traces on the surface.

Since the optical laminate 1 is usually manufactured as a long body, the layers bonded together by the first bonding layer 31 are also long bodies. When such a long body is conveyed using a bonding roll and a conveyance roll, traces of foreign matter biting may occur in the resulting optical laminate 1 due to contact with these rolls. As described above, when the first bonding layer 31 is a cured layer of a radically polymerizable adhesive composition, sufficient hardness can be obtained even immediately after curing, so that it does not deform under external forces. Therefore, it is possible to suppress the occurrence of foreign matter biting marks on the optical laminate 1.

On the other hand, when the first bonding layer 31 is a cured product layer of a cationic adhesive composition, it is likely to come into contact with the bonding roll or the conveyance roll in a state where the curing reaction has not sufficiently progressed. Therefore, compared to the case where the first bonding layer 31 is a cured layer of a radically polymerizable adhesive composition, foreign matter bite marks are more likely to occur in the optical laminate 1. Details of the first bonding layer 31 will be described later.

It is preferable that the second bonding layer 32 and the third bonding layer 33 are bonding layers having a glass transition temperature (hereinafter also referred to as "Tg") of 25° C. or lower. A bonding layer having a Tg of 25° C. or lower can be referred to as a so-called adhesive layer formed using an adhesive composition (pressure-sensitive adhesive). The third bonding layer 33 can be a bonding layer for bonding the optical laminate 1 to a display element of a display device. When the Tg of the third bonding layer 33 is 25° C. or less, even if the separator 38 is bonded to the side of the third bonding layer 33 of the optical laminate 1 opposite to the second liquid crystal retardation layer 22 side. good.

As shown in FIG. 1, the distance from the surface of the protective layer 11 opposite to the liquid crystal polarizer 15 side to the surface of the third bonding layer 33 opposite to the second liquid crystal retardation layer 22 side is D1. [μm], the total thickness Dt of the first lamination layer 31, second lamination layer 32, and third lamination layer 33 (adhesive layer) whose Tg is 25° C. or less (adhesive layer) is preferably 40% or more and 70% or less of the distance D1, more preferably 40% or more and 67% or less, may be 45% or more and 65% or less, and 50% or more and 65% or less. You can. In the optical laminate 1, the layer (adhesive layer) whose Tg is 25° C. or less among the first bonding layer 31, the second bonding layer 32, and the third bonding layer 33 is the second bonding layer 32. and a third bonding layer 33. Therefore, the total thickness Dt is equal to the total thickness D2 [μm] of the thickness of the second bonding layer 32 and the thickness of the third bonding layer 33. In this case, the total thickness D2 is preferably 40% or more and 70% or less of the distance D1, more preferably 40% or more and 67% or less, may be 45% or more and 65% or less, and may be 50% or more. It may be 65% or less.

The optical laminate 1 can be easily bent due to the above-mentioned thinning, and therefore can be suitably used in a flexible display device in which the display screen can be bent or rolled. When applying the optical laminate 1 to a flexible display device and bending it, if the total thickness D2 is smaller than the above range, the third bonding layer 33 will easily tear due to expansion and contraction of the third bonding layer 33 due to bending. Become. On the other hand, if the total thickness D2 of the second bonding layer 32 and the third bonding layer 33 is larger than the above range, in the polishing process of the optical laminate 1, the first liquid crystal retardation layer 21 and/or the second liquid crystal Cracks are likely to occur in the retardation layer 22. When a processing impact is applied to the optical laminate 1, the second bonding layer 32 and the third bonding layer 33, each having a Tg of 25° C. or lower, tend to be more easily deformed as their total thickness increases. When the second bonding layer 32 and the third bonding layer 33 are significantly deformed, the first liquid crystal retardation layer 21 and/or the second liquid crystal retardation layer 22 are deformed accordingly. It is considered that cracks are likely to occur in the retardation layer 21 and/or the second liquid crystal retardation layer 22. Details of the second bonding layer 32 and the third bonding layer 33 will be described later.

In the optical laminate 1, the thicknesses of the protective layer 11, the liquid crystal polarizer 15, the first liquid crystal retardation layer 21, and the second liquid crystal retardation layer 22 are preferably less than 20.0 μm. The thickness of the protective layer 11, the liquid crystal polarizer 15, the first liquid crystal retardation layer 21, and the second liquid crystal retardation layer 22 may all be less than 20.0 μm, and each independently preferably has a thickness of 15.0 μm. or less, more preferably 10.0 μm or less, further preferably 5.0 μm or less, even more preferably less than 5.0 μm, particularly preferably 4.5 μm or less, and most preferably 4.0 μm or less. It is 0 μm or less, 3.5 μm or less, or 3.0 μm or less. The thickness of the protective layer 11, the liquid crystal polarizer 15, the first liquid crystal retardation layer 21, and the second liquid crystal retardation layer 22 is usually 0.01 μm or more, and even 0.1 μm or more, each independently. good. When the thickness of each of the layers described above is within the above range, it becomes easier to suppress occurrence of unevenness in the reflected hue of the bent portion when the optical laminate 1 is repeatedly bent.

The thickness of the protective layer 11 may be within the above range, but is preferably 0.1 μm or more and less than 20.0 μm, more preferably 0.1 μm or more and 10.0 μm or less, and even more preferably 0.1 μm. It is 5.0 μm or more, more preferably 0.1 μm or more and 4.5 μm or less, and most preferably 0.1 μm or more and 4.0 μm or less.

The thickness of the liquid crystal polarizer 15 may be within the above range, but is preferably 0.1 μm or more and 10.0 μm or less, more preferably 0.3 μm or more and 5.0 μm or less, and even more preferably 0.1 μm or more and 5.0 μm or less. It is 5 μm or more and 3.0 μm or less.

The thickness of the first liquid crystal retardation layer 21 and the second liquid crystal retardation layer 22 may be within the above range, but independently, for example, preferably 0.1 μm or more and 10.0 μm or less, and more preferably Preferably it is 0.3 μm or more and 5.0 μm or less, and more preferably 0.3 μm or more and 3.0 μm or less.

The optical laminate 1 can be a circularly polarizing plate, and in this case, the optical laminate 1 can be used as an antireflection film.

(Method for manufacturing optical laminate)
The optical laminate 1 includes a protective layer 11, a liquid crystal polarizer 15, a first bonding layer 31, a first liquid crystal retardation layer 21, a second bonding layer 32, a second liquid crystal retardation layer 22, and a third bonding layer. The layers 33 can be manufactured by laminating them. The order of stacking each layer is not particularly limited. For example, [i] a laminate in which a first liquid crystal retardation layer 21 and a second liquid crystal retardation layer 22 are laminated via a second bonding layer 32 on a laminate in which a protective layer 11 and a liquid crystal polarizer 15 are laminated. After the body (retardation material) is laminated via the first lamination layer 31, the third lamination layer 33 may be laminated, and [ii] a lamination in which the protective layer 11 and the liquid crystal polarizer 15 are laminated. After laminating the first liquid crystal retardation layer 21 on the body via the first lamination layer 31, the second liquid crystal retardation layer 22 is laminated through the second lamination layer 32, and then the third lamination layer 33 may be stacked.

(display device)
The optical laminate 1 can be applied to a display device. The display device includes an optical laminate 1 and a display element, and the optical laminate 1 is arranged on the viewing side of the display element. The optical laminate 1 can be bonded to a display element using the third bonding layer 33.

The display device is not particularly limited, and examples include display devices such as an organic electroluminescent (organic EL) display device, an inorganic electroluminescent (inorganic EL) display device, a liquid crystal display device, and an electroluminescent display device. When the optical laminate 1 is a circularly polarizing plate, it can be suitably used as an antireflection film for an organic EL display device. The optical laminate 1 can be suitably used in a flexible display device whose display screen can be folded or rolled.

The display device can be used as a mobile device such as a smartphone or a tablet, a television, a digital photo frame, an electronic signboard, a measuring device or instruments, office equipment, medical equipment, computer equipment, etc.

The details of each member constituting the optical laminate and the members used to manufacture each layer will be described below.
(Polarizer)
A polarizing plate is a film containing a liquid crystal polarizer, and is a film that exhibits the optical function of a liquid crystal polarizer. The polarizing plate may be a liquid crystal polarizer alone, or may be a laminate in which this and a protective layer are directly laminated, and the polarizing plate may include a protective layer, a liquid crystal polarizer, and an overcoat layer (second protective layer). It may be a laminate in which these are directly laminated.

The polarization performance of a 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 calculated by calculating the single transmittance and degree of polarization at each wavelength using the following formulas (Formula 1) and (Formula 2), and further using the 2-degree field of view (C light source) of JIS Z 8701. By performing the visibility 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 chromaticities 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, the hue of the polarizing plate itself can be determined. (single hue), a hue in which polarizing plates are arranged in parallel (parallel hue), and a hue in which polarizing plates are arranged orthogonally (orthogonal hue) are 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 (Formula 1)
Degree of polarization [%] = [(T1-T2)/(T1+T2)]×100 (Formula 2)

The visibility correction polarization degree Py of the polarizing plate is usually 80% or more, preferably 90% or more, more preferably 95% or more, even more preferably 98% or more, particularly preferably 99% or more, and 99.9 % or more, it can be suitably used for liquid crystal display devices. Increasing the visibility correction polarization degree Py of the polarizing plate is advantageous in improving the antireflection function of the optical laminate. When the visibility correction polarization degree Py is less than 80%, when the optical laminate is used as an antireflection film, it may be difficult to exhibit a sufficient antireflection function.

As the visibility correction single transmittance Ty of the polarizing plate increases, the clarity during white display increases, but as can be seen from the relationship between (Formula 1) and (Formula 2) above, if the single transmittance becomes too large, There is a problem that the degree of polarization becomes small. Therefore, the visibility correction single transmittance Ty is preferably 30% or more and 60% or less, more preferably 35% or more and 55% or less, still more preferably 40% or more and 50% or less, and still more preferably 40% or more and 55% or less. % or more and 45% or less. If the visibility correction single transmittance Ty is too large, the visibility correction polarization degree Py becomes too small, and when the optical laminate is used as an antireflection film, it may be difficult to exhibit a sufficient antireflection function.

The polarizing plate may be obtained by [i] directly forming a liquid crystal polarizer on the first base layer and using the first base layer as a protective layer, as described below, and [ii] using the first base layer. A material layer having a resin film and a surface treatment layer formed thereon is used, and after forming a liquid crystal polarizer on the surface treatment layer, the resin film included in the first base layer is peeled off and removed. , it may be obtained by using the surface treatment layer as a protective layer. Alternatively, [iii] the first base layer used in forming the liquid crystal polarizer may be peeled off and a protective layer may be laminated on the liquid crystal polarizer. When the polarizing plate has an overcoat layer, the overcoat layer may be formed on the liquid crystal polarizer on the first base layer.

(liquid crystal polarizer)
A liquid crystal polarizer is a film that has an absorption axis in a plane and a transmission axis perpendicular to the absorption axis, absorbs polarized light components parallel to the absorption axis, and transmits polarized light components parallel to the transmission axis. The liquid crystal polarizer is a film consisting of a single layer (cured material layer) made of a polymer of a polymerizable liquid crystal compound containing a dichroic dye, or a two-layer structure consisting of this layer and an alignment film. In a liquid crystal polarizer, dichroic dyes are oriented in one direction within the plane. The liquid crystal polarizer is produced by uniaxially aligning the dichroic dye and the polymerizable liquid crystal compound from a first liquid crystal composition containing the polymerizable liquid crystal compound and the dichroic dye. It can be formed as a layer including a layer (cured material layer) made of a polymer. That is, the liquid crystal polarizer can exhibit a polarizing function by anisotropically absorbing light by the dichroic dye included in the polymer of the polymerizable liquid crystal compound.

The liquid crystal polarizer including the cured product layer of the first liquid crystal composition has the following advantages: the hue can be controlled arbitrarily, the thickness can be made significantly thinner, and there is almost no stretching relaxation due to heat and the liquid crystal polarizer has non-shrinkage properties. For example, it can be suitably used for flexible display devices.

The liquid crystal polarizer has a ratio of absorbance A1 (λ) in the alignment direction to light absorbance A2 (λ) in the vertical direction within the alignment plane (dichroic ratio; A1 (λ)/A2 (λ)) for light with a wavelength λ [nm]. ) is preferably 7 or more, more preferably 20 or more, still more preferably 40 or more. The larger this value is, the better the absorption selectivity of the liquid crystal polarizer can be said to be. Although it depends on the type of dichroic dye, in the case of a cured layer cured in a nematic liquid crystal phase, the above ratio is about 5 to 10.

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

In the liquid crystal polarizer, a first liquid crystal composition is coated on a first base layer on which a first alignment film is formed, if necessary, and the dichroic dye contained in the first liquid crystal composition is aligned. can be formed by The liquid crystal polarizer can include a first alignment film in addition to the cured material layer. The first base layer may be used as a protective layer as it is, a resin film included in the first base layer may be used as a protective layer, or the resin film may be peeled off and the first base layer You may use the surface treatment layer contained in this as a protective layer. The first alignment film may be peeled off and removed together with the resin film. The resin film and the first alignment film may be peeled off and removed after the liquid crystal polarizer is laminated with the first liquid crystal retardation layer and the second liquid crystal retardation layer.

(First liquid crystal composition)
The first liquid crystal composition is a composition for forming a liquid crystal polarizer, and in addition to a dichroic dye and a polymerizable liquid crystal compound, it further contains a solvent, a leveling agent, a polymerization initiator, a sensitizer, a polymerization inhibitor, and a crosslinking agent. It may also contain additives such as adhesives, adhesives, and reactive additives. From the viewpoint of processability, the first liquid crystal composition preferably contains a solvent and a leveling agent.

A polymerizable liquid crystal compound is a compound that has at least one polymerizable group in its molecule and has liquid crystallinity. 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 and acryloyloxy group are 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 may be a polymer obtained by polymerizing a dimer or more.

When the polymerizable liquid crystal compound contained in the first liquid crystal composition 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. You can. From the viewpoint of obtaining a liquid crystal polarizer (cured material layer) with a large dichroic ratio, the liquid crystal state exhibited by the polymerizable liquid crystal compound is preferably a smectic phase, and if it is a high-order smectic phase, from the viewpoint of high performance. More preferred. 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, a smectic F phase, or a smectic I phase. When the liquid crystal phase formed by the polymerizable liquid crystal compound is one of these higher-order smectic phases, a liquid crystal polarizer (cured material layer) with high polarization performance can be manufactured. In addition, a liquid crystal polarizer (cured material layer) having 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 a periodic structure of molecular orientation, and a layer having a periodic interval of 3 to 6 Å can be obtained. The cured product layer included in the liquid crystal polarizer preferably contains a polymer of the polymerizable liquid crystal compound oriented in a smectic phase from the viewpoint of obtaining higher polarization characteristics.

As the polymerizable liquid crystal compound contained in the first liquid crystal composition, one type may be used alone, or two or more types may be used in combination. The content of the polymerizable liquid crystal compound in the first liquid crystal composition is preferably 40% by mass or more and 99.9% by mass or less, more preferably 60% by mass or more and 99% by mass or less, based on the solid content of the first liquid crystal composition. It is not more than 70% by mass and not more than 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 first liquid crystal composition.

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 the 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 azo dyes include compounds represented by formula (Da).
T ¹ -A ¹ (-N=NA ² ) _p -N=NA ³ -T ² (Da)
[In formula (Da),
A ¹ , A ² and A ³ are each independently a 1,4-phenylene group which may have a substituent, a naphthalene-1,4-diyl group which may have a substituent, Represents a benzoic acid phenyl ester group which may have a substituent, a 4,4'-stilbenylene group which may have a substituent, or a divalent heterocyclic group which may have a substituent. ,
T ¹ and T ² represent an electron-withdrawing group or an electron-emitting group, and are located at substantially 180° with respect to the azo bond plane.
p represents an integer from 0 to 4, and 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 as long as it exhibits absorption in the visible light region. ]

From the viewpoint of obtaining good light absorption characteristics, the content of the dichroic dye (or the total amount when it contains multiple types) contained in the first liquid crystal composition is usually determined based on 100 parts by mass of the polymerizable liquid crystal compound. The amount is 1 to 60 parts by weight, preferably 1 to 40 parts by weight, and 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.

The first liquid crystal composition may contain a solvent. Generally, a polymerizable liquid crystal compound has a high viscosity, so by dissolving the first liquid crystal composition in a solvent, coating becomes easier, and as a result, it is often easier to form a cured product layer of a liquid crystal polarizer. 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 alcohol 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. , 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 first liquid crystal composition. In other words, the solid content in the first liquid crystal composition is preferably 2 to 50% by mass, more preferably 5 to 30% by mass.

The first liquid crystal composition may contain a leveling agent. The 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. Examples of the leveling agent include organically modified silicone oil-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. Among these, polyacrylate leveling agents and perfluoroalkyl leveling agents are preferred.

When the first liquid crystal composition contains a leveling agent, it is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, based on 100 parts by weight of the polymerizable liquid crystal compound.

The first liquid crystal composition 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, etc. 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 first liquid crystal composition can be adjusted as appropriate depending on the type and amount of the polymerizable liquid crystal compound, but is usually 0.1 parts by mass per 100 parts by mass of the polymerizable liquid crystal compound. ~30 parts by weight, preferably 0.5 to 10 parts by weight, 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.

The first liquid crystal composition may contain a sensitizer. As the sensitizer, a photosensitizer is preferred. When the first liquid crystal composition contains a sensitizer, the polymerization reaction of the polymerizable liquid crystal compound contained in the first liquid crystal composition can be further promoted. The amount of the sensitizer used is preferably 0.1 to 30 parts by weight based on 100 parts by weight of the polymerizable liquid crystal compound.

From the viewpoint of stably advancing the polymerization reaction, the first liquid crystal composition 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. When the first liquid crystal composition 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.

(protective layer)
The protective layer has a function of protecting the surface of the liquid crystal polarizer. The liquid crystal polarizer and the protective layer are directly laminated to each other. Here, "directly laminated" refers to an aspect in which the protective layer is laminated to the liquid crystal polarizer due to its self-adhesive property, and if necessary, a protective layer coated on the protective layer on which the first alignment film is formed. This includes an embodiment in which a protective layer is laminated on the liquid crystal polarizer by curing the first liquid crystal composition for forming the cured product layer of the liquid crystal polarizer. The protective layer may be subjected to surface activation treatment (for example, corona treatment, etc.) in order to improve adhesion with the liquid crystal polarizer, and a thin layer such as a primer layer (also referred to as an easy-to-adhesion layer) is formed. may have been done.

The protective layer may be a first base layer for forming a liquid crystal polarizer, or may include a part of the first base layer. The protective layer may have a single layer structure or a multilayer structure. Preferably, the protective layer includes a resin layer. The resin layer may be a resin film and/or a surface treatment layer.

As the resin film, for example, a film having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, stretchability, etc. can be used. The resin film may be a thermoplastic resin film. Specific examples of resins constituting such a resin film include cellulose resins such as triacetylcellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resins; polysulfone resins; polycarbonate resins; Polyamide resins such as nylon and aromatic polyamides; Polyimide resins; Chain polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; Cyclic polyolefin resins having a cyclo or norbornene structure (also known as norbornene resins) (meth)acrylic resins such as polymethyl methacrylate; polyarylate resins; polystyrene resins; polyvinyl alcohol resins, and mixtures thereof. Resin films made of such materials are easily available on the market. The resin may be a thermosetting resin such as a (meth)acrylic type, a urethane type, a (meth)acrylic urethane type, an epoxy type, a silicone type, or an ultraviolet curing type resin. In this specification, "(meth)acrylic" refers to at least one of acrylic and methacryl. The same applies to the notation of (meth)acryloyl and the like.

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. 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 (typical examples include are random copolymers), graft polymers obtained by modifying these with unsaturated carboxylic acids or derivatives thereof, and hydrogenated products 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. Examples 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, cyclohexanedimethanol, and the like.

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. Copolymers having multiple types of polymerized units constituting these cellulose ester resins and those in which a portion of the hydroxyl groups are modified with other substituents are also included. 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.).

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.

A protective layer can be produced by stretching the resin film (thermoplastic resin film) described above. 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).

Since the protective layer is disposed on the viewing side of the liquid crystal polarizer, it includes a resin film and a surface treatment layer provided on the surface of the resin film in order to impart desired surface optical properties or other characteristics. It's okay to stay. Alternatively, the protective layer may not include a resin film but may include a surface treatment layer as a resin layer. When the protective layer does not include a resin film but includes a surface treatment layer, for example, the protective layer as the surface treatment layer can be laminated on the liquid crystal polarizer as follows. First, a mold release treatment is performed to form a mold release layer by coating a mold release agent etc. on the surface of the resin film on which the surface treatment layer is to be formed, and the surface on which the surface treatment layer is formed on the mold release layer. Prepare processing film. Next, this surface-treated film is applied to a liquid crystal polarizer, a laminate of a liquid crystal polarizer and a first liquid crystal retardation layer, or a laminate of a liquid crystal polarizer, a first liquid crystal retardation layer, and a second liquid crystal retardation layer. After laminating on the body, the resin film is peeled off. Thereby, it is possible to obtain an optical laminate that does not include a resin film but includes a surface treated layer as a protective layer.

Examples of the surface treatment layer include a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, an antifouling layer, an antisticking layer, and the like. The surface treatment layer may be formed by coating the surface of the resin film or a release layer formed on the resin film, and when the protective layer includes a resin film, it may be formed by modifying the surface of the resin film. may have been done.

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 resin film.

The hard coat layer has a function of increasing the surface hardness of the protective layer, and is provided for the purpose of preventing scratches on the surface. By forming a hard coat layer on the resin film, the hardness and scratch resistance of the protective layer can be improved. The hard coat 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)". It is preferable that the optical film exhibits a value of H or harder (measured by placing an optical film having a hard coat layer on a glass plate).

The hard coat 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 hard coat layer can also contain additives such as antioxidants, ultraviolet absorbers, light stabilizers, antistatic agents, leveling agents, and antifoaming agents.

(overcoat layer)
The polarizing plate may have an overcoat layer (second protective layer) that covers the surface of the liquid crystal polarizer on the first liquid crystal retardation layer side. The overcoat layer can be formed by applying a material (composition) constituting the overcoat layer, such as a photocurable resin or a water-soluble polymer, to the surface of the liquid crystal polarizer, and drying or curing the material. Examples of photocurable resins include (meth)acrylic resins, urethane resins, (meth)acrylic urethane resins, epoxy resins, and silicone resins. Examples of water-soluble polymers include poly(meth)acrylamide-based polymers; polyvinyl alcohol, and ethylene-vinyl alcohol copolymers, ethylene-vinyl acetate copolymers, and (meth)acrylic acid or its anhydride-vinyl alcohol copolymers. Examples include vinyl alcohol polymers such as polymers, carboxyvinyl polymers, polyvinylpyrrolidone, starches, sodium alginate, and polyethylene oxide polymers.

The thickness of the overcoat layer is usually 0.1 μm or more and 10.0 μm or less, preferably 5.0 μm or less, and more preferably 3.0 μm or less. If the thickness of the overcoat layer is 10 μm or more, the unevenness of reflection hue at the bent part will be more noticeable in the flexibility test, and if it is less than 0.1 μm, the function of preventing dye diffusion in a high-temperature environment is likely to be impaired. Become.

(First liquid crystal retardation layer and second liquid crystal retardation layer)
The first liquid crystal retardation layer and the second liquid crystal retardation layer are films that exhibit a retardation in the plane or in the thickness direction, and are layers (cured material layers) made of a polymer of a polymerizable liquid crystal compound, or The film has a two-layer structure consisting of this layer and an alignment film. The first liquid crystal retardation layer and the second liquid crystal retardation layer include a cured layer of a second liquid crystal composition containing a polymerizable liquid crystal compound. The first liquid crystal retardation layer and/or the second liquid crystal retardation layer may each include a second alignment film. The second liquid crystal composition for forming the first liquid crystal retardation layer 21 and the second liquid crystal composition for forming the second liquid crystal retardation layer 22 may be the same or different from each other. You can leave it there.

The first liquid crystal retardation layer and the second liquid crystal retardation layer are usually formed by coating a second liquid crystal composition on a second alignment film formed on a second base layer, and applying the second liquid crystal composition to the second alignment film formed on the second base layer. It is formed by polymerizing the included polymerizable liquid crystal compound. The first liquid crystal retardation layer and the second liquid crystal retardation layer usually include a layer in which a polymerizable liquid crystal compound is cured in an oriented state. It is necessary to be a cured product layer in which the polymerizable groups of the polymerizable liquid crystal compound are polymerized while being oriented in the horizontal direction with respect to the surface of the base material layer. At this time, when the polymerizable liquid crystal compound is a rod-shaped liquid crystal compound, the liquid crystal retardation layer can be made into a positive A plate, and when the polymerizable liquid crystal compound is a disc-shaped liquid crystal compound, the liquid crystal retardation layer can be made into a negative plate. It can be an A plate.

In order to achieve a high level of anti-reflection function of the optical laminate, the combination of the first liquid crystal retardation layer and the second liquid crystal retardation layer must have a λ/4 plate function (i.e., π/2 order) in the entire visible light range. phase difference function). Moreover, it is preferable that the first liquid crystal retardation layer or the second liquid crystal retardation layer included in the optical laminate is a reverse wavelength dispersion λ/4 layer. It is also preferable to combine two or more types of liquid crystal retardation layers with different orientations as the first liquid crystal retardation layer and the second liquid crystal retardation layer. As a combination of two or more types of liquid crystal retardation layers, for example, a liquid crystal retardation layer (hereinafter also referred to as "λ/2 layer") having a positive wavelength dispersion λ/2 plate function (i.e. π retardation function) ) and a liquid crystal retardation layer (hereinafter also referred to as "λ/4 layer") having a positive wavelength dispersion λ/4 plate function (that is, a π/2 retardation function). Alternatively, from the viewpoint of compensating the antireflection function in an oblique direction, one of the first liquid crystal retardation layer and the second liquid crystal retardation layer is a layer having anisotropy in the thickness direction (positive C plate). The other layer may be a reverse wavelength dispersion λ/4 layer. Moreover, the first liquid crystal retardation layer and the second liquid crystal retardation layer may each form a tilted alignment state or a cholesteric alignment state.

When the combination of the first liquid crystal retardation layer and the second liquid crystal retardation layer is adjusted to have a λ/4 plate function in the entire visible light range, the first liquid crystal retardation layer and the second liquid crystal retardation layer In the retardation body including the retardation layer, it is preferable that Re(λ), which is an in-plane retardation for light with a wavelength λ [nm], satisfies the optical property shown in the following formula (1), and the following formula (2 ) and (3) are preferably satisfied. A retardation film is a laminated film in which a plurality of retardation plates are laminated, and is a laminated film that exhibits a retardation in the plane or in the thickness direction based on the plurality of laminated retardation plates. The retardation plate is a film that includes a first liquid crystal retardation layer or a second liquid crystal retardation layer, and is a film that exhibits an optical function as the first liquid crystal retardation layer or the second liquid crystal retardation layer.
100nm<Re(550)<160nm (1)
Re(450)/Re(550)≦1.0 (2)
1.00≦Re(650)/Re(550) (3)
[In formulas (1) to (3),
Re (450) represents the in-plane retardation value of the retardation material for light with a wavelength of 450 nm,
Re (550) represents the in-plane retardation value of the retardation material for light with a wavelength of 550 nm,
Re(650) represents the in-plane retardation value of the retardation material for light with a wavelength of 650 nm. ]

When "Re(450)/Re(550)" in the above formula (2) exceeds 1.0, light leakage on the short wavelength side of the optical laminate including the retardation material becomes large. "Re(450)/Re(550)" is preferably 0.7 or more and 1.0 or less, more preferably 0.80 or more and 0.95 or less, and even more preferably 0.80 or more and 0.95 or less. It is 92 or less, particularly preferably 0.82 or more and 0.88 or less. The value of "Re(450)/Re(550)" is determined by the mixing ratio of the polymerizable liquid crystal compound in the second liquid crystal composition, the stacking angle of the first liquid crystal retardation layer and the second liquid crystal retardation layer, and these factors. It can be arbitrarily adjusted by adjusting the phase difference value of .

The in-plane retardation values of the first liquid crystal retardation layer and the second liquid crystal retardation layer can be adjusted by adjusting the thicknesses of both liquid crystal retardation layers. Since the in-plane retardation value is determined by the following formula (4), in order to obtain the desired in-plane retardation value (Re(λ)), it is sufficient to adjust Δn(λ) and the film thickness d. . The thickness of the first liquid crystal retardation layer and the second liquid crystal retardation layer is preferably 0.5 μm or more and 5 μm or less, and more preferably 1 μm or more and 3 μm or less. The thicknesses of the first liquid crystal retardation layer and the second liquid crystal retardation layer can be measured using an interference thickness meter, a laser microscope, or a stylus thickness meter, respectively. Note that Δn(λ) depends on the molecular structure of the polymerizable liquid crystal compound described below.
Re(λ)=d×Δn(λ) (4)
[In formula (4),
Re (λ) represents the in-plane retardation value of the liquid crystal retardation layer at the wavelength λ [nm],
d represents the thickness of the liquid crystal retardation layer,
Δn(λ) represents the birefringence at wavelength λ [nm]. ]

When using a combination of a positive wavelength dispersion λ/2 layer and a positive wavelength dispersion λ/4 layer as a retardation material adjusted to have a λ/4 plate function in the entire visible light range, the following formula is used. (1), a layer having optical properties represented by formulas (6), and formula (7), and a layer having optical properties represented by formulas (5) to (7) below, using a specific slow phase They can be combined in axial relation.
100nm<Re(550)<160nm (1)
200nm<Re(550)<320nm (5)
Re(450)/Re(550)≧1.00 (6)
1.00≧Re(650)/Re(550) (7)
[In formulas (1) and (5) to (7),
Re (450) represents the in-plane retardation value of the retardation material for light with a wavelength of 450 nm,
Re (550) represents the in-plane retardation value of the retardation material for light with a wavelength of 550 nm,
Re(650) represents the in-plane retardation value of the retardation material for light with a wavelength of 650 nm. ]

Examples of the method of combining the λ/2 layer and the λ/4 layer include well-known methods described in JP-A No. 2015-163935, WO 2013/137464, and the like. From the viewpoint of viewing angle compensation, preferably a λ/2 layer formed from a second liquid crystal composition containing a disk-shaped polymerizable liquid crystal compound and a λ/2 layer formed from a second liquid crystal composition containing a rod-shaped polymerizable liquid crystal compound. /4 layers are preferably used.

The positive C plate is not particularly limited as long as it has anisotropy in the thickness direction, but if it does not have tilt orientation or cholesteric orientation, it has optical characteristics expressed by the following formula (8).
nx≒ny<nz (8)
[In formula (8),
nx represents the principal refractive index at wavelength λ [nm] in the plane of the positive C plate.
ny represents the refractive index of the positive C plate at wavelength λ [nm] in the same plane as nx and in the direction perpendicular to nx.
nz(λ) represents the refractive index at wavelength λ [nm] in the thickness direction of the positive C plate.
When nx≈ny, nx can be the refractive index in any direction within the plane of the positive C plate. ]

The positive C plate has a retardation value Rth (550) in the thickness direction at a wavelength of 550 nm, which is usually in the range of -170 nm or more and -10 nm or less, preferably in the range of -150 nm or more and -20 nm or less, and more preferably -100 nm. The range is -40 nm or more. If the retardation value in the thickness direction is within this range, the antireflection properties from oblique directions can be further improved.

The positive C plate is preferably formed from a second liquid crystal composition containing a rod-shaped polymerizable liquid crystal compound.

As the first liquid crystal retardation layer and the second liquid crystal retardation layer, in addition to the above-mentioned configurations, tilt alignment or cholesteric alignment may be used without any particular restriction as long as the structure achieves the antireflection function. I can do it. Examples of the configuration include well-known configurations described in WO2021/060378, WO2021/132616, WO2021/132624, and the like.

(Second liquid crystal composition)
The second liquid crystal composition is a composition for forming the first liquid crystal retardation layer and a composition for forming the second liquid crystal retardation layer. The second liquid crystal composition contains a polymerizable liquid crystal compound, and further contains additives such as a solvent, a leveling agent, a polymerization initiator, a sensitizer, a polymerization inhibitor, a crosslinking agent, an adhesive, and a reactive additive. It's okay to stay. From the viewpoint of processability, the second liquid crystal composition preferably contains a solvent and a leveling agent. Examples of the additive include those explained in the first liquid crystal composition, and the content of the additive in the second liquid crystal composition may also be within the range explained in the first liquid crystal composition. can.

The polymerizable liquid crystal compound contained in the second liquid crystal composition means a liquid crystal compound having at least one polymerizable group, particularly a photopolymerizable group, in the molecule, and examples of the polymerizable liquid crystal compound include, for example, a retardation film. Polymerizable liquid crystal compounds conventionally known in the art can be used. The liquid crystal may be a thermotropic liquid crystal or a lyotropic liquid crystal, but a thermotropic liquid crystal is preferable because it allows precise control of the film thickness. The phase ordered structure in thermotropic liquid crystals may be nematic liquid crystals or smectic liquid crystals. It may be a rod-shaped liquid crystal or a disc-shaped liquid crystal. The polymerizable liquid crystal compounds can be used alone or in combination of two or more.

［式（Ｉ）中、
Ａｒは置換基を有していてもよい二価の芳香族基を表す。該二価の芳香族基中には窒素原子、酸素原子、硫黄原子のうち少なくとも１つ以上が含まれることが好ましい。二価の基Ａｒに含まれる芳香族基が２つ以上である場合、２つ以上の芳香族基は互いに単結合、－ＣＯ－Ｏ－、－Ｏ－等の二価の結合基で結合していてもよい。
Ｇ^１及びＧ^２はそれぞれ独立に、二価の芳香族基又は二価の脂環式炭化水素基を表す。ここで、該二価の芳香族基又は二価の脂環式炭化水素基に含まれる水素原子は、ハロゲン原子、炭素数１～４のアルキル基、炭素数１～４のフルオロアルキル基、炭素数１～４のアルコキシ基、シアノ基又はニトロ基に置換されていてもよく、該二価の芳香族基又は二価の脂環式炭化水素基を構成する炭素原子が、酸素原子、硫黄原子又は窒素原子に置換されていてもよい。
Ｌ^１、Ｌ^２、Ｂ^１及びＢ^２はそれぞれ独立に、単結合又は二価の連結基である。
ｋ、ｌは、それぞれ独立に０～３の整数を表し、１≦ｋ＋ｌの関係を満たす。ここで、２≦ｋ＋ｌである場合、Ｂ^１及びＢ^２、Ｇ^１及びＧ^２は、それぞれ互いに同一であってもよく、異なっていてもよい。
Ｅ^１及びＥ^２はそれぞれ独立に、炭素数１～１７のアルカンジイル基を表し、ここで、アルカンジイル基に含まれる水素原子は、ハロゲン原子で置換されていてもよく、該アルカンジイル基に含まれる－ＣＨ_２－は、－Ｏ－、－Ｓ－、－ＣＯＯ－で置換されていてもよく、－Ｏ－、－Ｓ－、－ＣＯＯ－を複数有する場合は互いに隣接しない。
Ｐ^１及びＰ^２は互いに独立に、重合性基又は水素原子を表し、少なくとも１つは重合性基である。］ The polymerizable liquid crystal compound used to obtain the λ/4 layer with reverse wavelength dispersion is a T-shaped or A liquid crystal having an H-type mesogenic structure is preferable, and a T-shaped liquid crystal is more preferable from the viewpoint of obtaining stronger dispersion. Specifically, the structure of the T-shaped liquid crystal is, for example, one represented by the following formula (I). Examples include compounds that are

[In formula (I),
Ar represents a divalent aromatic group which may have a substituent. Preferably, the divalent aromatic group contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom. When the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups are bonded to each other through a single bond or a divalent bonding group such as -CO-O- or -O-. You can leave it there.
G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, or a fluoroalkyl group having 1 to 4 carbon atoms. It may be substituted with 1 to 4 alkoxy groups, cyano groups, or nitro groups, and the carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group are oxygen atoms, sulfur atoms. Alternatively, it may be substituted with a nitrogen atom.
L ¹ , L ² , B ¹ and B ² are each independently a single bond or a divalent linking group.
k and l each independently represent an integer from 0 to 3, and satisfy the relationship 1≦k+l. Here, when 2≦k+l, B ¹ and B ² and G ¹ and G ² may be the same or different from each other.
E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, where the hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and the alkanediyl group The -CH ₂ - contained therein may be substituted with -O-, -S-, or -COO-, and when a plurality of -O-, -S-, or -COO- are present, they are not adjacent to each other.
P ¹ and P ² each independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group. ]

G ¹ and G ² are each independently preferably a 1,4-phenylenediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms. , a 1,4-cyclohexanediyl group optionally substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, and more preferably a 1,4-cyclohexanediyl group substituted with a methyl group. ,4-phenylenediyl group, unsubstituted 1,4-phenylenediyl group, or unsubstituted 1,4-trans-cyclohexanediyl group, particularly preferably unsubstituted 1,4-phenylenediyl group or unsubstituted It is a substituted 1,4-trans-cyclohexanediyl group.
Furthermore, at least one of the plurality of G ¹ and G ² is preferably a divalent alicyclic hydrocarbon group, and at least one of G ¹ and G ² bonded to L ¹ or L ² More preferably, one is a divalent alicyclic hydrocarbon group.

L ¹ and L ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a1 OR ^a2 -, -R ^a3 COOR ^a4 -, -R ^a5 OCOR ^a6 -, R ^a7 OC=OOR ^a8 -, -N=N-, -CR ^c =CR ^d -, or C≡C-. Here, R ^a1 to R ^a8 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms, and R ^c and R ^d represent an alkyl group having 1 to 4 carbon atoms or a hydrogen atom. L ¹ and L ² are each independently more preferably a single bond, -O ^Ra2-1 -, -CH ₂ -, -CH ₂ CH ₂ -, -COOR ^a4-1 -, or OCOR ^a6-1 - . Here, R ^a2-1 , R ^a4-1 , and R ^a6-1 each independently represent a single bond, -CH ₂ -, or -CH ₂ CH ₂ -. L ¹ and L ² are each independently more preferably a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, or OCO-.

B ¹ and B ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R ^a9 OR ^a10 -, -R ^a11 COOR ^a12 -, -R ^a13 OCOR ^a14 -, or R ^a15 OC=OOR ^a16 -. Here, R ^a9 to R ^a16 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms. B ¹ and B ² are each independently more preferably a single bond, -OR ^a10-1 -, -CH ₂ -, -CH ₂ CH ₂ -, -COOR ^a12-1 -, or OCOR ^a14-1 - . Here, R ^a10-1 , R ^a12-1 , and R ^a14-1 each independently represent a single bond, -CH ₂ -, or -CH ₂ CH ₂ -. B ¹ and B ² are each independently, more preferably, a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH ₂ CH ₂ -, -OCO-, or OCOCH ₂ CH ₂ - .

From the viewpoint of expressing reverse wavelength dispersion, k and l are preferably in the range of 2≦k+l≦6, preferably k+l=4, and more preferably k=2 and l=2. It is preferable that k=2 and l=2 because a symmetrical structure is obtained.

E ¹ and E ² are each independently preferably an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms.

Examples of the polymerizable group represented by P ¹ or P ² include epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, acryloyloxy group, methacryloyloxy group, and oxiranyl group. , and oxetanyl group. Among these, acryloyloxy group, methacryloyloxy group, vinyloxy group, oxiranyl group and oxetanyl group are preferable, and acryloyloxy group is more preferable.

It is preferable that Ar has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocycle which may have a substituent, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include a benzene ring, a naphthalene ring, an anthracene ring, and the like, with benzene rings and naphthalene rings being preferred. The aromatic heterocycles include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, and a pyrazole ring. , thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, and phenanthroline ring. Among these, it is preferable to have a thiazole ring, benzothiazole ring, or benzofuran ring, and more preferably to have a benzothiazole group. Further, when Ar includes a nitrogen atom, it is preferable that the nitrogen atom has π electrons.

In formula (I), the total number Nπ of π electrons contained in the divalent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, still more preferably 14 or more, and particularly preferably is 16 or more. Further, it is preferably 30 or less, more preferably 26 or less, and still more preferably 24 or less.

［式（Ａｒ－１）～式（Ａｒ－２３）中、
＊印は連結部を表し、
Ｚ^０、Ｚ^１及びＺ^２は、それぞれ独立に、水素原子、ハロゲン原子、炭素数１～１２のアルキル基、シアノ基、ニトロ基、炭素数１～１２のアルキルスルフィニル基、炭素数１～１２のアルキルスルホニル基、カルボキシル基、炭素数１～１２のフルオロアルキル基、炭素数１～６のアルコキシ基、炭素数１～１２のアルキルチオ基、炭素数１～１２のＮ－アルキルアミノ基、炭素数２～１２のＮ，Ｎ－ジアルキルアミノ基、炭素数１～１２のＮ－アルキルスルファモイル基又は炭素数２～１２のＮ，Ｎ－ジアルキルスルファモイル基を表す。
Ｑ^１及びＱ^２は、それぞれ独立に、－ＣＲ^２’Ｒ^３’－、－Ｓ－、－ＮＨ－、－ＮＲ^２’－、－ＣＯ－又はＯ－を表し、Ｒ^２’及びＲ^３’は、それぞれ独立に、水素原子又は炭素数１～４のアルキル基を表す。
Ｊ^１、及びＪ^２は、それぞれ独立に、炭素原子、又は窒素原子を表す。
Ｙ^１、Ｙ^２及びＹ^３は、それぞれ独立に、置換されていてもよい芳香族炭化水素基又は芳香族複素環基を表す。
Ｗ^１及びＷ^２は、それぞれ独立に、水素原子、シアノ基、メチル基又はハロゲン原子を表す。
ｍは０～６の整数を表す。］ Preferred examples of the aromatic group represented by Ar include the following groups.

[Formula (Ar-1) to formula (Ar-23),
*mark indicates a connecting part,
Z ⁰ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, or a C 1 to 12 alkyl group. Alkylsulfonyl group, carboxyl group, fluoroalkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkylthio group having 1 to 12 carbon atoms, N-alkylamino group having 1 to 12 carbon atoms, carbon number It represents an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylsulfamoyl group having 1 to 12 carbon atoms, or an N,N-dialkylsulfamoyl group having 2 to 12 carbon atoms.
Q ¹ and Q ² each independently represent -CR ^2' R ^3' -, -S-, -NH-, -NR ^2' -, -CO- or O-, and R ² ' and R ^3' each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
J ¹ and J ² each independently represent a carbon atom or a nitrogen atom.
Y ¹ , Y ² and Y ³ each independently represent an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group.
W ¹ and W ² each independently represent a hydrogen atom, a cyano group, a methyl group, or a halogen atom.
m represents an integer from 0 to 6. ]

Examples of the aromatic hydrocarbon group for Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group, and biphenyl group. , naphthyl group is preferred, and phenyl group is more preferred. Examples of the aromatic heterocyclic group include a group having 4 to 20 carbon atoms and containing at least one hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom, such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group. Examples include aromatic heterocyclic groups, and furyl, thienyl, pyridinyl, thiazolyl, and benzothiazolyl groups are preferred.

Y ¹ , Y ² and Y ³ may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or a polycyclic aromatic heterocyclic group. The polycyclic aromatic hydrocarbon group refers to a fused polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly. The polycyclic aromatic heterocyclic group refers to a fused polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.

Z ⁰ , Z ¹ and Z ² are each independently preferably a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms; ⁰ is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group, and Z ¹ and Z ² are more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.

Q ¹ and Q ² are preferably -NH-, -S-, -NR ^2' -, -O-, and R ^2' is preferably a hydrogen atom. Among them, -S-, -O-, and -NH- are particularly preferred.

Among the compounds represented by formulas (Ar-1) to (Ar-23), compounds represented by formulas (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.

In the compounds represented by formulas (Ar-16) to (Ar-23), Y ¹ may form an aromatic heterocyclic group together with the nitrogen atom to which it is bonded and Z ⁰ . Examples of the aromatic heterocyclic group include those mentioned above as the aromatic heterocycle that Ar may have, such as a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, and an indole ring. ring, quinoline ring, isoquinoline ring, purine ring, pyrrolidine ring, etc. This aromatic heterocyclic group may have a substituent. Moreover, Y ¹ may be the aforementioned optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group, together with the nitrogen atom to which it is bonded and Z ⁰ . Examples include a benzofuran ring, a benzothiazole ring, a benzoxazole ring, and the like.

Among polymerizable liquid crystal compounds, compounds having a maximum absorption wavelength of 300 to 400 nm are preferred. This is advantageous in terms of long-term stability of the second liquid crystal composition, and improves the orientation and uniformity of the film thickness of the cured product layer of the second liquid crystal composition contained in the first liquid crystal retardation layer and the second liquid crystal retardation layer. You can improve. Note that the maximum absorption wavelength of the polymerizable liquid crystal compound can be measured in a solvent using an ultraviolet-visible spectrophotometer. The solvent is a solvent that can dissolve the polymerizable liquid crystal compound, and includes, for example, chloroform.

［式（Ｗ）中、Ｒ^４０は、下記式（Ｗ－１）～（Ｗ－５）を表す。］

［式（Ｗ－１）～（Ｗ－５）中、
Ｘ^４０及びＺ^４０は、それぞれ独立して、炭素数１～１２のアルカンジイル基を表し、該アルカンジイル基に含まれる水素原子は、炭素数１～５のアルコキシ基で置換されていてもよく、該アルコキシ基に含まれる水素原子は、ハロゲン原子で置換されていてもよい。また、該アルカンジイル基を構成する－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置き換わっていてもよい。
ｍ２は、整数を表す。］ Examples of the discotic polymerizable liquid crystal compound include a compound containing a group represented by formula (W) (hereinafter also referred to as "polymerizable liquid crystal compound (W)").

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

[In formulas (W-1) to (W-5),
X ⁴⁰ and Z ⁴⁰ each independently 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 atom contained in the alkoxy group may be substituted with a halogen atom. Furthermore, -CH ₂ - constituting the alkanediyl group may be replaced with -O- or -CO-.
m2 represents an integer. ]

Examples of the rod-shaped polymerizable liquid crystal compound include compounds represented by formula (II), formula (III), formula (IV), formula (V), formula (VI), or formula (VII).
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (II)
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (III)
P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (IV)
P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (V)
P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (VI)
P11-B11-E11-B12-A11-B13-A12-F11 (VII)
[In formulas (II) to (VII),
A11 to A14 each independently represent a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or It may be substituted with a nitro group, and the hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.
B11 and B17 are each independently -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR ¹⁶ -, -NR ¹⁶ -CO- , -CO-, -CS-, or a single bond. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
B12 to B16 each independently represent -C≡C-, -CH=CH-, -CH ₂ -CH ₂ -, -O-, -S-, -C(=O)-, -C(=O ) -O-, -OC(=O)-, -OC(=O)-O-, -CH=N-, -N=CH-, -N=N-, -C(=O ) -NR ¹⁶ -, -NR ¹⁶ -C(=O)-, -OCH ₂ -, -OCF ₂ -, -CH ₂ O-, -CF ₂ O-, -CH=CH-C(=O)- Represents O-, -OC(=O)-CH=CH- or a single bond.
E11 and E12 each independently 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; A hydrogen atom contained in the group may be substituted with a halogen atom. Furthermore, -CH ₂ - constituting the alkanediyl group may be replaced with -O- or -CO-.
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.
P11 and P12 each independently represent a polymerizable group. ]

The content of the polymerizable liquid crystal compound in the second 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 solid content of the second liquid crystal composition. be. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of orientation of the obtained cured product layer (cured liquid crystal film). Note that in this specification, the solid content of the second liquid crystal composition means all the components of the second liquid crystal composition excluding volatile components such as organic solvents.

(First base layer, second base layer)
Examples of the first base layer to which the first liquid crystal composition is applied and the second base layer to which the second liquid crystal composition is applied include glass substrates and film substrates, with film substrates being preferred. A long roll-shaped film is more preferable since the liquid crystal polarizer, the first liquid crystal retardation layer, and the second liquid crystal retardation layer can be manufactured continuously. The first liquid crystal composition and the second liquid crystal composition may be applied onto alignment films formed on the first base layer and the second base layer, respectively.

Examples of the resin constituting the film base material include olefin resins such as polyethylene and polypropylene; cyclic olefin resins having a cyclo or norbornene structure; polyvinyl alcohol; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; ) Acrylic resins; cellulose ester resins such as triacetylcellulose, diacetylcellulose and cellulose acetate propionate; polyimide resins; polycarbonates; polysulfones; polyethersulfones; polyetherketones; polyphenylene sulfides; polyphenylene oxides and the like.

A commercially available cellulose ester resin base material may be used as the film base material. Examples of such cellulose ester resin base materials include "FujiTac Film" (manufactured by Fuji Photo Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (all manufactured by Konica Minolta Opto Co., Ltd.), etc. .

A commercially available cyclic olefin resin may be used as the cyclic olefin resin constituting the film base material. Examples of such cyclic olefin resins include "Topas" (registered trademark) (manufactured by Ticona (Germany)), "Aton" (registered trademark) (manufactured by JSR Corporation), and "ZEONOR" (registered trademark). , "ZEONEX" (registered trademark) (manufactured by Nippon Zeon Co., Ltd.), and "APEL" (registered trademark) (manufactured by Mitsui Chemicals, Inc.).

When using the entire first base layer or a part thereof as a protective layer, the first base layer preferably has the material and layer structure described above for the protective layer. When using a part of the first base material layer as a protective layer, for example, a release layer is formed on the surface of the film base material, and after forming a liquid crystal polarizer on the film base material, the film base material can be peeled off and removed. Just do it.

The thinner the first base layer and the second base layer are, the more preferable they are in terms of mass that allows practical handling, but if they are too thin, the strength tends to decrease and the workability tends to be poor. From this point of view, the thickness of the first base layer and the second base layer is usually 5 μm to 300 μm, preferably 10 μm to 200 μm, and more preferably 10 to 50 μm, each independently. The first base layer is peeled off to transfer the liquid crystal polarizer (cured layer of the first liquid crystal composition), and the second base layer is peeled off to transfer the first liquid crystal retardation layer and the second liquid crystal retardation layer. By transferring, the optical laminate can be made thinner.

(First alignment film, second alignment film)
The first alignment film and the second alignment film have alignment regulating power to align the liquid crystal of the polymerizable liquid crystal compound in a desired direction.

The first alignment film and the second alignment film facilitate 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 first alignment film, the second alignment film, and the polymerizable liquid crystal compound, and the combination thereof can be arbitrarily selected. . For example, if the first alignment film and/or the second alignment film are materials that exhibit horizontal alignment as an alignment regulating force, the polymerizable liquid crystal compound can form horizontal alignment or hybrid alignment, and can exhibit vertical alignment. If it is a material, the polymerizable liquid crystal compound can form vertical alignment or oblique alignment. Expressions such as "horizontal" and "vertical" refer to the direction of the long axis of the oriented polymerizable liquid crystal compound, with reference to the planes of the liquid crystal polarizer, the first liquid crystal retardation layer, and the second liquid crystal retardation 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 liquid crystal polarizer, the first liquid crystal retardation layer, or the second liquid crystal retardation layer. Vertical here means 90°±20° with respect to the plane of the liquid crystal polarizer, the first liquid crystal retardation layer, or the second liquid crystal retardation 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.

When the first alignment film and the second alignment film are formed between the film base material or the glass base material and the cured product layer of the first liquid crystal composition or the second liquid crystal composition, the first alignment film or the second alignment film Preferably, it is insoluble in the solvent contained in the second liquid crystal composition and has heat resistance during heat treatment for removing the solvent and aligning the polymerizable liquid crystal compound. Examples of the first alignment film and the second alignment film include, independently, an alignment film made of an alignment polymer, a photo alignment film, a groove alignment film, a stretched film stretched in the orientation direction, etc. When applied to a long roll film, a photo-alignment film is preferred because the orientation direction can be easily controlled.

The thickness of the first alignment film and the second alignment film are each independently generally 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 alignment polymers used in the rubbing alignment film include polyamides and gelatins having an amide bond in the molecule, polyimide having an imide bond 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 applying an oriented polymer composition to the base material using a rotating rubbing roll wrapped around a rubbing cloth and annealing it to form an oriented polymer composition on the surface of the film base material or glass base material. An example of this method is to bring a polymer film into contact with the polymer.

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 A group having 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) is more preferable.

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 directly from the film surface, or the polarized light may be irradiated from the film or glass substrate side and the polarized light may be transmitted. 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 photoreactive group of a polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) having a wavelength in the range of 250 to 400 nm is particularly preferred.

(First lamination layer, adhesive layer)
The first bonding layer is a cured product layer of an active energy ray-curable composition, and is a bonding layer called a so-called adhesive layer. The adhesive layer can be formed using an adhesive composition.

Examples of the adhesive composition include water-based adhesive compositions, active energy ray-curable 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.

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

A cationic 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 such as diglycidyl ether (compounds having an aromatic ring and an epoxy group in the molecule); aliphatic epoxy compounds such as 2-ethylhexyl glycidyl ether and 1,4-butanediol diglycidyl ether (aliphatic 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 cationically polymerizable 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 -Iron-arene complexes such as cyclopentadienyl iron (II) hexafluoroantimonate and the like. 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 JP-A No. 2016-126345 and JP-A No. 2021-113969.

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.
The radically polymerizable adhesive composition preferably 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 fluidity regulator, a plasticizer, an antifoaming agent, It may contain additives such as antistatic agents, leveling agents, and solvents.

An adhesive composition is applied to the bonding surface of at least one of the first bonding layer or the two layers bonded by the adhesive layer, and After laminating the above two layers and pressing them from above and below using a laminating roll, etc., the coating layer is dried, the coating layer is cured by irradiating active energy rays, or it is cured by heating. This can be done by letting
Before forming the coating layer of the adhesive composition, at least one of the bonding surfaces of the two layers is subjected to adhesion-facilitating treatment such as saponification treatment, corona treatment, plasma treatment, primer treatment, anchor coating treatment, etc. You can.
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 with 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} more. .
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 cured product layer (adhesive layer) formed from the active energy ray-curable adhesive composition may be, for example, 10 μm or less, preferably 5 μm or less, and more preferably 3 μm or less. , 0.1 μm or more, preferably 0.5 μm or more, and more preferably 1 μm or more.

(Second lamination layer, third lamination layer)
The second bonding layer and the third bonding layer are bonding layers having a glass transition temperature Tg of 25° C. or lower. A bonding layer having a Tg of 25° C. or lower can be formed using, for example, an adhesive composition. The Tg of the bonding layer can be measured using a differential scanning calorimeter (DSC).

As the adhesive composition, conventionally known adhesive compositions with excellent optical transparency can be used without particular limitation, such as (meth)acrylic resins, urethane resins, silicone resins, polyvinyl ether resins, etc. An adhesive composition having a base polymer such as a resin can be used. Moreover, an active energy ray-curable adhesive composition, a thermosetting adhesive composition, etc. may be used. Among these, a pressure-sensitive adhesive composition using an acrylic resin as a base polymer, which has excellent 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.

［式（ＶＩＩＩ）中、
Ｒ^１０は、水素原子又はメチル基を表し、
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、分岐状又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。］ 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 (VIII) (hereinafter also referred to as "structural unit (VIII)"). 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 formula (VIII),
R ¹⁰ represents a hydrogen atom or a methyl group,
R ²⁰ represents an alkyl group having 1 to 20 carbon atoms, the alkyl group may have a linear, branched or cyclic structure, and the hydrogen atom of the alkyl group has 1 to 20 carbon atoms. It may be substituted with ~10 alkoxy groups. ]

Examples of the (meth)acrylic ester represented by formula (VIII) include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, 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 (VIII). 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 amino group substituted with an alkyl group having 1 to 6 carbon atoms or an unsubstituted amino group; 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. It is not more than 0.5 parts by mass and not more than 10 parts by mass, still more preferably not less than 1 part by mass and not more than 5 parts by mass.

Monomers having aromatic groups 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.

The content of structural units derived from monomers having an aromatic group in the (meth)acrylic acid ester polymer is preferably 4 parts by mass based on 100 parts by mass of all structural units of the (meth)acrylic acid ester polymer. It is at least 4 parts by mass and at most 15 parts by mass, more preferably at least 4 parts by mass and at most 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. etc.

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

The weight average molecular weight (hereinafter also simply referred to as "Mw") of the (meth)acrylic resin is preferably 500,000 to 2,500,000. When the weight average molecular weight is 500,000 or more, the durability of the adhesive layer under high temperature and high humidity environments 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 an optical laminate including an adhesive layer formed of the above resin. The above 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. Examples of such (meth)acrylic acid ester polymers include those whose main component is the structural unit (VIII) derived from the aforementioned (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.

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 and the like, isocyanate compounds are preferred. The proportion of the crosslinking agent is, for example, 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.

The adhesive composition may further contain a silane compound. The content of the silane compound in the adhesive composition is usually 0.01 to 10 parts by mass based on 100 parts by mass of (meth)acrylic resin.

The adhesive composition may further contain an antistatic agent. Known antistatic agents may be used, and ionic antistatic agents are preferred. 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 preferably 0.01 to 20 parts by weight, more preferably 1 to 7 parts by weight, based on 100 parts by weight of the (meth)acrylic resin.

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.

The adhesive layer has a storage modulus at a temperature of 25° C., preferably from 1.0×10 ⁴ Pa to 1.0×10 ⁶ Pa, more preferably from 1.0×10 ⁴ Pa to 1.0×10 ⁵ Pa. Storage modulus can be obtained by dynamic viscoelasticity measurements.

The adhesive layer has a creep amount ΔCr at a temperature of 70° C., for example, 65 μm or less, 50 μm or less, 45 μm or less, 40 μm or less, 35 μm or less, 30 μm or less, 25 μm or less, 20 μm or less, or even 15 μm or less. . The lower limit of the creep amount ΔCr is, for example, 0.5 μm. If the creep amount is within this range, it is possible to suppress adhesive chipping, adhesive staining, and poor cutting when cutting the optical laminate, as in the case of the storage modulus. The creep value can be measured, for example, by the following procedure: A load of 500 gf is applied to the adhesive layer attached to a stainless steel test plate at a joint surface of 20 mm long x 20 mm wide, with the test plate fixed. is added vertically downward. The creep amount (slip amount) of the adhesive layer with respect to the test plate is measured at each time point 100 seconds and 3600 seconds after the start of applying the load, and is set as Cr ₁₀₀ and Cr ₃₆₀₀ , respectively. From the measured Cr ₁₀₀ and Cr ₃₆₀₀ , the creep amount ΔCr can be determined by the formula ΔCr=Cr ₃₆₀₀ −Cr ₁₀₀ .

(separator)
The separator is releasably provided to the third bonding layer for bonding the optical laminate to the display element, and covers and protects the surface of the third bonding layer. When peeling the separator from the third bonding layer of the optical laminate with a separator, the separator can be peeled off while maintaining the shape of the third bonding layer. As the separator, one having a base film and a release treatment layer is preferable. Examples of the base film include films made of resin, and examples of the resin include film base materials used for the first base layer and the second base layer. The release treatment layer may be any known release treatment layer, such as a layer formed by coating a base film with a release agent such as a fluorine compound or a silicone compound.

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

[Measurement of thickness]
Unless otherwise specified, a laser microscope (LEXT, manufactured by Olympus Corporation) or a digital micrometer "MH-15M" manufactured by Nikon Corporation was used to measure the thickness of each layer.

[Production of polarizing plate (1) with base material layer]
(Preparation of first liquid crystal composition)
A first liquid crystal composition was obtained by mixing the following components and stirring at a temperature of 80° C. for 1 hour. Polymerizable liquid crystal compounds (X1) and (X2) have the structures shown below. Dichroic dyes (DP1) to (DP3) are azo dyes described in Examples of JP-A-2013-101328, and have the structures shown below.
Polymerizable liquid crystal compound (X1): 75 parts Polymerizable liquid crystal compound (X2): 25 parts Dichroic dye (DP1): 2.5 parts Dichroic dye (DP2): 2.5 parts Dichroic dye (DP3) ): 2.5 parts Polymerization initiator [2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure (registered trademark) 369; manufactured by BASF Japan): 6 parts Leveling agent [Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)]: 1.2 parts Solvent [o-xylene]: 250 parts

・重合性液晶化合物（Ｘ２）：

・Polymerizable liquid crystal compound (X1):

・Polymerizable liquid crystal compound (X2):

・二色性色素（ＤＰ２）：

・二色性色素（ＤＰ３）：

・Dichroic dye (DP1):

・Dichroic dye (DP2):

・Dichroic dye (DP3):

・溶剤［ｏ－キシレン］：９８部 (Preparation of composition (1) for forming photo-alignment film)
The following components described in JP-A-2013-033249 were mixed, and the resulting mixture was stirred at 80° C. for 1 hour to obtain a composition for forming a photo-alignment film (1).
・Photoalignable polymer with the structure shown below: 2 parts

・Solvent [o-xylene]: 98 parts

(Preparation of water-soluble polymer aqueous solution)
A water-soluble polymer consisting of the following structural units was obtained according to the following synthesis scheme.

In 400 g of dimethyl sulfoxide, 20 g of polyvinyl alcohol with a molecular weight of 1000 (manufactured by Wako Pure Chemical Industries, Ltd.), 0.55 mg of N,N-dimethyl-4-aminopyridine as a nucleophile, and 4.6 g of triethylamine were dissolved and stirred. At the same time, the temperature was raised to 60°C. Thereafter, a solution of 10.5 g of methacrylic anhydride dissolved in 50 g of dimethyl sulfoxide was added dropwise over 1 hour, and the mixture was heated and stirred at 60° C. for 14 hours to cause a reaction. After cooling the obtained reaction solution to room temperature, 481 g of methanol was added to the reaction solution and stirred to mix completely, so that the ratio (mass) of the reaction solution and methanol was adjusted to 1:1. . By gradually adding 1500 mL of acetone to this solution, the water-soluble polymer was crystallized by a crystallization method. The resulting solution containing white crystals was filtered, thoroughly washed with acetone, and then vacuum dried to obtain 20.2 g of a water-soluble polymer. The obtained water-soluble polymer was dissolved in water to prepare a 3% by mass water-soluble polymer aqueous solution.

・ウレタンアクリレート樹脂［ＥＢＥＣＲＹＬ４８５８（ダイセル・オルネクス株式会社製）］：３０部
・重合開始剤［Ｏｍｎｉｒａｄ９０７（ＩＧＭ Ｒｅｓｉｎｓ Ｂ．Ｖ社製）］：３部
・溶媒［メチルエチルケトン］：１０部 (Preparation of composition for forming HC layer)
The following components were mixed and stirred at a temperature of 50° C. for 4 hours to obtain a composition for forming a hard coat (HC) layer.
・Acrylate monomer with the structure shown below: 70 parts

・Urethane acrylate resin [EBECRYL4858 (manufactured by Daicel Allnex Corporation)]: 30 parts ・Polymerization initiator [Omnirad 907 (manufactured by IGM Resins B.V.)]: 3 parts ・Solvent [methyl ethyl ketone]: 10 parts

(Preparation of polarizing plate (1) with base material layer)
The above was applied to the release-treated side of a roll-shaped release polyethylene terephthalate (PET) film (“FF-50” manufactured by Unitika Co., Ltd., one-sided release-treated PET film (thickness of supporting base material: 50 μm)) with a film width of 800 mm. The HC layer forming composition obtained in step 1 was continuously applied using a slot die coater, and dried at a temperature of 100° C. for 2 minutes to form an HC layer (protective layer) with a thickness of 2.00 μm. As a result, a film was obtained in which the HC layer was laminated on the release-treated side of the single-sided release-treated PET film, and this was used as the first base layer (1).

After subjecting the HC layer of the first base layer (1) to plasma treatment, the photo-alignment film forming composition (1) prepared above was applied using a slot die coater to form a single-sided release-treated PET film. A coating layer was formed in a width range of 600 mm at the center of the sample. Subsequently, the solvent was removed by transporting for 2 minutes in a ventilation drying oven set at a temperature of 100° C., and the coating layer on the HC layer was dried. Thereafter, the dried coating layer is irradiated with polarized UV light directed at 90° to the length direction of the single-sided release-treated PET film at an intensity of 20 mJ/cm ² (313 nm standard). A photo-alignment film (1) was formed on the HC layer by applying an alignment regulating force. The thickness of the photo-alignment film (1) was about 50 nm.

The first liquid crystal composition prepared above is applied onto the photo-alignment film (1) formed on the first base layer (1) using a slot die coater, and A coating layer was formed over a width of 600 mm. Subsequently, the solvent was removed by transporting for 2 minutes in a ventilation drying oven set at a temperature of 110° C., and the coating layer on the first base layer (1) was dried. Thereafter, the cured product layer of the first liquid crystal composition is cured by irradiating ultraviolet light at 1000 mJ/cm ² (365 nm standard) using a high-pressure mercury lamp to cure the polymerizable liquid crystal compound contained in the dried coating layer. A liquid crystal polarizer (1) with a base material layer was obtained in which a photo-alignment film (1) and a cured material layer (together with a liquid crystal polarizer) were formed in this order on the first base layer (1). . The liquid crystal polarizer (1) with a base material layer had an absorption axis in a direction of 90° with respect to the length direction. The thickness of the cured material layer was 3 μm.

Next, the liquid crystal polarizer side of the liquid crystal polarizer (1) with a base material layer was subjected to plasma treatment, and then the water-soluble polymer aqueous solution prepared above was continuously applied using a slot die coater at a temperature of 100°C. was dried for 2 minutes to form an overcoat layer (second protective layer) with a thickness of 2 μm. As a result, a long base comprising the first base layer (1) (one-sided release treated PET film/HC layer)/liquid crystal polarizer (photo alignment film (1)/cured material layer)/overcoat layer is formed in this order. A polarizing plate (1) with a material layer was obtained.

The obtained polarizing plate with a base material layer (1) was cut into a square with a size of 40 mm x 40 mm. The overcoat layer side was coated with an alkali-free glass plate (manufactured by Corning Corporation, product name "Eagle-XG") using an acrylic adhesive with a thickness of 25 μm (manufactured by Lintec Corporation, product name "P-3132"). After lamination, the single-sided release-treated PET film was peeled off to obtain a test piece.

The single transmittance (T1) in the transmission axis direction and the single transmittance (T2) in the absorption axis direction of the obtained test specimen were measured by setting a folder with a polarizer in a spectrophotometer (UV-3150, manufactured by Shimadzu Corporation). Using the device, measurements were made in the wavelength range of 380 to 680 nm in 2 nm steps by the double beam method. Using the following formulas (Formula 1) and (Formula 2), calculate the single transmittance and degree of polarization at each wavelength, and then perform visibility correction using the 2-degree visual field (C light source) of JIS Z 8701. Single transmittance (Ty) and visibility correction polarization degree (Py) were calculated.
Single transmittance [%] = (T1+T2)/2 (Formula 1)
Degree of polarization [%] = [(T1-T2)/(T1+T2)]×100 (Formula 2)

As a result, the test specimen had a visibility-corrected single transmittance (Ty) of 42% and a visibility-corrected polarization degree (Py) of 97%, which were confirmed to be useful values as a polarizing plate. Furthermore, after heating the test specimen at a temperature of 100°C for 120 hours, the visibility-corrected single transmittance (Ty) and visibility-corrected polarization degree (Py) were calculated using the above procedure. The visibility-corrected single transmittance (Ty) was 42%, the visibility-corrected polarization degree (Py) was 97%, and no deterioration in optical performance was observed.

[Production of polarizing plate (2) with base material layer]
The polarizing plate with a base material layer (2) was prepared using the procedure for producing the polarizing plate with a base material layer (1), except that the thickness of the HC layer (protective layer) formed on the single-sided release-treated PET film was changed to 3.95 μm. ) was created.

[Production of polarizing plate (3) with base material layer]
The polarizing plate with a base material layer (3) was prepared in the same manner as the polarizing plate with a base material layer (1), except that the thickness of the HC layer (protective layer) formed on the single-sided release-treated PET film was changed to 4.95 μm. ) was created.

[Preparation of first liquid crystal retardation layer (1)]
(Preparation of alignment film forming composition (1))
Water was added to commercially available polyvinyl alcohol (Polyvinyl Alcohol 1000 completely saponified type, manufactured by Wako Pure Chemical Industries, Ltd.) and heated at a temperature of 100° C. for 1 hour to obtain a composition for forming an alignment film (1).

(Preparation of second liquid crystal composition (1))
Mix the polymerizable liquid crystal compound (X3) and polymerizable liquid crystal compound (X4) shown below, add the leveling agent, photopolymerization initiator, and ionic compound shown below, and further add the solvent shown below. A mixture was obtained. A second liquid crystal composition (1) was prepared by stirring this mixture at a temperature of 80° C. for 1 hour. Polymerizable liquid crystal compounds (X3) and (X4) were prepared according to the method described in JP-A-2010-244038, and have the structures shown below. The ionic compound has the structure shown below.
Polymerizable liquid crystal compound (X3): 80 parts Polymerizable liquid crystal compound (X4): 20 parts Leveling agent [Megafac F-556 (manufactured by DIC)]: 0.1 part Photopolymerization initiator [Omnirad 907 (IGM Resin B. V. Co.)]: 2.5 parts Ionic compound: 0.1 part Solvent [cyclopentanone]: 650 parts

・重合性液晶化合物（Ｘ４）：

・Polymerizable liquid crystal compound (X3):

・Polymerizable liquid crystal compound (X4):

・Ionic compounds:

(Preparation of first liquid crystal retardation layer (1) with base material layer)
A cycloolefin polymer (COP) film (manufactured by Nippon Zeon Co., Ltd., ZF14) cut into a rectangle was subjected to corona treatment using a corona treatment device (AGF-B10; manufactured by Kasuga Denki Co., Ltd.), and then a composition for forming an alignment film was prepared. Material (1) was applied and dried by heating to form an alignment film with a thickness of 100 nm. The surface of the obtained alignment film was rubbed at an angle of 75° from the longitudinal direction of the COP film, and the second liquid crystal composition (1) was applied thereon using a bar coater. After drying the obtained coating film at a temperature of 120°C for 2 minutes, it was exposed to light at a temperature of 80°C under a nitrogen atmosphere using a high-pressure mercury lamp (Unicure VB-15201BY-A manufactured by Ushio Inc.). A cured product of a polymerizable liquid crystal compound that is cured by irradiating the dry film with ultraviolet light of 1000 mJ/cm ² (365 nm standard) so that the optical axis of the polymerizable liquid crystal compound is oriented horizontally to the COP film surface. A layer (1-1) was formed. As a result, the first liquid crystal retardation layer (1) with a base material layer consisting of the second base material layer (COP film)/first liquid crystal retardation layer (1) (alignment film/cured material layer (1-1)) I got it.

The thickness of the obtained cured product layer (1-1) was measured using a laser microscope and was found to be 2 μm. The in-plane retardation value of the first liquid crystal retardation layer (1) 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. Note that since the retardation value of the COP film at a wavelength of 550 nm is approximately 0, the COP film does not affect the optical properties of the first liquid crystal retardation layer (1). The orientation angle was −15° with respect to the longitudinal direction of the COP film.

[Preparation of second liquid crystal retardation layer (1)]
(Preparation of second liquid crystal composition (2))
A second liquid crystal composition ( 2) was prepared. The polymerizable liquid crystal compound (X5) has the structure shown below.
Polymerizable liquid crystal compound (X5) [Paliocolor LC242 (manufactured by BASF Japan)]: 100 parts Leveling agent [BYK-361N (manufactured by BYK-Chemie)]: 0.1 part Photopolymerization initiator [Omnirad907 (IGM Resin B. V. Co.)]: 2.5 parts Solvent [propylene glycol 1-monomethyl ether 2-acetate (PGME)]: 400 parts

・Polymerizable liquid crystal compound (X5):

(Preparation of second liquid crystal retardation layer (1) with base material layer)
The composition for forming an alignment film (1) was applied to a triacetyl cellulose (TAC) film (KC4UY, manufactured by Konica Minolta, Inc.) cut into a rectangle, and after heating and drying, an alignment film with a thickness of 100 nm was formed. The surface of the obtained alignment film was subjected to a rubbing treatment at an angle of 15° from the longitudinal direction of the TAC film, and the second liquid crystal composition (2) was applied thereon using a bar coater. The obtained coating film was dried at a temperature of 100° C. for 1 minute, and then cooled to room temperature to obtain a dry film. Next, the dried film was 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 (Unicure VB-15201BY-A manufactured by Ushio Inc.). A cured layer (2-1) of a polymerizable liquid crystal compound was formed by curing the polymerizable liquid crystal compound in a state in which the optical axis of the compound was oriented horizontally to the TAC film surface. As a result, a second base layer with a base material layer consisting of a second base material layer (TAC film)/second liquid crystal retardation layer (1) (alignment film/cured material layer (2-1) (horizontal alignment liquid crystal cured film)) is formed. A liquid crystal retardation layer (1) was obtained.

The thickness of the obtained cured product layer (2-1) was measured using a laser microscope and was found to be 1 μm. The in-plane retardation value of the second liquid crystal retardation layer (1) 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)=140 nm. Note that since the retardation value of the TAC film at a wavelength of 550 nm is approximately 0, the TAC film does not affect the optical properties of the second liquid crystal retardation layer (1). The orientation angle was 75° with respect to the longitudinal direction of the TAC film.

[Preparation of first liquid crystal retardation layer (2)]
(Preparation of photo-alignment film forming composition (2))
A composition for forming a photoalignment film (2) was obtained by mixing 2 parts of a photoalignment material having the structure shown below and 98 parts of cyclopentanone (solvent) and stirring at a temperature of 80°C for 1 hour. . A photoalignable material having the following structure (weight average molecular weight: 50000, m:n=50:50) was synthesized according to the method described in JP-A-2021-196514.
Photoalignable material:

(Preparation of second liquid crystal composition (3))
The following polymerizable liquid crystal compound (X6), polymerizable liquid crystal compound (X7), leveling agent, and photopolymerization initiator were mixed, and N-methyl-2-pyrrolidone ( A second liquid crystal composition (3) was prepared by mixing NMP) and stirring at a temperature of 80° C. for 1 hour. The polymerizable liquid crystal compound (X6) and the polymerizable liquid crystal compound (X7) have the structures shown below. The polymerizable liquid crystal compound (X6) was prepared in the same manner as the method described in JP-A-2019-003177. Polymerizable liquid crystal compound (X7) was prepared in the same manner as described in JP-A-2009-173893.
Polymerizable liquid crystal compound (X6): 90 parts Polymerizable liquid crystal compound (X7): 10 parts Leveling agent [BYK-361N (manufactured by BM Chemie)]: 0.1 part Photopolymerization initiator [Irgacure OXE-03 (BASF Japan)] Co., Ltd.)]: 3 copies

・重合性液晶化合物（Ｘ７）：

・Polymerizable liquid crystal compound (X6):

・Polymerizable liquid crystal compound (X7):

A solution was obtained by dissolving 1 mg of polymerizable liquid crystal compound (X6) in 10 mL of chloroform. The obtained solution was placed in a measurement cell with an optical path length of 1 cm, and the measurement sample was set in an ultraviolet-visible spectrophotometer ("UV-2450" manufactured by Shimadzu Corporation) to measure the absorption spectrum. When the wavelength at which the maximum absorption occurs was read from the obtained absorption spectrum, the maximum absorption wavelength λmax in the wavelength range of 300 to 400 nm was 356 nm.

(Preparation of first liquid crystal retardation layer (2) with base material layer)
The photo-alignment film forming composition (2) was applied to a biaxially oriented polyethylene terephthalate (PET) film (Diafoil, manufactured by Mitsubishi Plastics Co., Ltd.) using a bar coater. The obtained coating layer was dried at a temperature of 120° C. for 2 minutes, and then cooled to room temperature to dry the coating layer. Thereafter, the dried coating layer was irradiated with 100 mJ of polarized ultraviolet light (313 nm standard) using a UV irradiation device (SPOT CURE SP-9; manufactured by Ushio Inc.) to form a photo-alignment film (2). I got it. The thickness of the photo-alignment film (2) measured using an ellipsometer M-220 manufactured by JASCO Corporation was 100 nm.

The second liquid crystal composition (3) prepared above was applied onto the photo-alignment film (2) on the PET film using a bar coater to form a coating layer. The coating layer was dried by heating at a temperature of 120° C. for 2 minutes, and then cooled to room temperature. After drying, the coated layer was exposed to ultraviolet light at an exposure amount of 500 mJ/cm ² (365 nm standard) in a nitrogen atmosphere using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.). A cured layer (1-2) of the second liquid crystal composition (3) was formed by irradiating the second liquid crystal composition (3) with the polymerizable liquid crystal compound oriented horizontally in the plane of the PET film. The thickness of the cured material layer (1-2) was 2 μm as measured using a laser microscope LEXT OLS4100 manufactured by Olympus Corporation. As a result, the first liquid crystal retardation layer with a base material layer consisting of the second base material layer (PET film)/first liquid crystal retardation layer (2) (photoalignment film (2)/cured material layer (1-2)) Layer (2) was obtained.

Corona treatment is performed on the first liquid crystal retardation layer (2) side of the first liquid crystal retardation layer (2) with a base material layer, and the first liquid crystal retardation layer with a base material layer is attached via a 25 μm pressure-sensitive adhesive manufactured by Lintec. Layer (2) was bonded to glass, and the PET film was peeled off and removed to obtain a test piece. The in-plane phase difference value of this test piece was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. The in-plane retardation values for light with wavelengths of 450 nm, 550 nm, and 650 nm are as follows: It was calculated using Cauchy's dispersion formula obtained from the measurement results. As a result, the in-plane retardation values are Re (450) = 122 nm, Re (550) = 140 nm, and Re (650) = 144 nm, and the relationship between the in-plane retardation values at each wavelength is as follows. Ta.
Re(450)/Re(550)=0.87
Re(650)/Re(550)=1.03
[In the formula, Re (450) is the in-plane retardation value for light with a wavelength of 450 nm, Re (550) is the in-plane retardation value for light with a wavelength of 550 nm, and Re (650) is the in-plane retardation value for light with a wavelength of 650 nm. Represents the phase difference value. ]

[Preparation of second liquid crystal retardation layer (2)]
(Preparation of composition for forming vertical alignment film)
2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, dipentaerythritol triacrylate, and bis(2-vinyloxyethyl) ether were mixed in a ratio of 1:1:4:5, and LUCIRIN was added as a polymerization initiator. A composition for forming a vertical alignment film was prepared by adding TPO at a rate of 4%.

(Preparation of second liquid crystal composition (4))
The second liquid crystal composition (4) was prepared from a photopolymerizable nematic liquid crystal compound (RMM28B, manufactured by Merck & Co., Ltd.) and a solvent such that the solid content was 1 to 1.5 g. The solvent used was a mixed solvent in which methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CHN) were mixed at a mass ratio (MEK: MIBK: CHN) of 35:30:35.

(Preparation of second liquid crystal retardation layer (2) with base material layer)
Opposite the release-treated side of a roll-shaped release polyethylene terephthalate (PET) film with a film width of 800 mm (“FF-50” manufactured by Unitika Co., Ltd., one-sided release-treated PET film (thickness of supporting base material: 50 μm)) After subjecting the surface to corona treatment, the composition for forming a vertical alignment film prepared above was applied using a slot die coater so that the thickness after curing would be 3 μm. The coating film was irradiated with ultraviolet rays of 200 mJ/cm ² to form a vertical alignment film on the single-sided release-treated PET film.

The second liquid crystal composition (4) prepared above was applied onto the vertical alignment film on the single-sided release-treated PET film using a slot die coater so that the thickness after curing was 1 μm. After drying the coating layer at a drying temperature of 75° C. and a drying time of 120 seconds, it was irradiated with ultraviolet rays (UV) to polymerize the polymerizable liquid crystal compound to form a cured layer (2-2). As a result, a second liquid crystal layer with a base layer consisting of a second base layer (one-sided release treated PET film)/second liquid crystal retardation layer (2) (vertical alignment film/cured material layer (2-2)) is formed. A retardation layer (2) was obtained. The second liquid crystal retardation layer (2) was a positive C plate.

[Preparation of active energy ray-curable composition (1) (cationic polymerizable adhesive composition)]
After mixing the components shown below, the mixture was defoamed to prepare an active energy ray-curable composition (1). Note that the photocationic polymerization initiator is blended as a 50% propylene carbonate solution, and the parts are shown in terms of solid content.
- Cationic polymerizable compound (1) [3-ethyl-3{[(3-ethyloxetan-3-yl)methoxy]methyl}oxetane (trade name: OXT-221, manufactured by Toagosei Co., Ltd.)]: 60. 0 parts Cationically polymerizable compound (2) [3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate (product name: CEL2021P, manufactured by Daicel Corporation)]: 32.5 parts Cationically polymerizable Compound (3) [1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol (trade name: EHPE3150, manufactured by Daicel Corporation)]: 7 .5 parts Photocationic polymerization initiator [CPI-100P (manufactured by San-Apro Co., Ltd., 50% by mass solution)]: 2.3 parts Photosensitizer [9,10-dibutoxyanthracene]: 1.0 part・Photosensitizing aid [1,4-diethoxynaphthalene]: 1.0 part

[Preparation of active energy ray curable composition (2) (radical polymerizable adhesive composition)]
The components shown below were mixed to prepare an active energy ray curable composition (2).
・N,N-dimethylacrylamide [manufactured by KJ Chemicals Co., Ltd.]: 65 parts ・Dicyclopentanyl acrylate [Hitachi Chemical Co., Ltd.]: 15 parts ・Ultraviolet curable urethane acrylate resin [product name: UV-3700B, Manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd., viscosity: 30,000 to 60,000 mPa・s/60°C, molecular weight (Mw): 38,000, number of oligomer functional groups: 2, glass transition temperature Tg: -6°C]: 20 1 part/Photoradical polymerization initiator [Omnirad 819 (2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one), BASF Japan Ltd.]: 3 parts

[Preparation of adhesive layer (1)]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 95.0 parts of n-butyl acrylate, 4.0 parts of acrylic acid, and 1.0 part of 2-hydroxyethyl acrylate were added. , 200 parts of ethyl acetate, and 0.08 part of 2,2'-azobisisobutyronitrile were charged, and the air in the reaction vessel was replaced with nitrogen gas. The reaction solution was heated to 60°C while stirring under a nitrogen atmosphere, reacted for 6 hours, and then cooled to room temperature.

When the weight average molecular weight of a part of the obtained solution was measured, it was confirmed that a (meth)acrylic acid ester polymer of 1.8 million was produced. The weight average molecular weight (Mw) of the (meth)acrylic resin is the weight average molecular weight in terms of polystyrene measured using gel permeation chromatography (GPC) under the following conditions.
〔Measurement condition〕
・GPC measurement device: Tosoh Corporation, HLC-8020
・GPC column (passed in the following order): TSK guard column HXL-H manufactured by Tosoh Corporation
TSK gel GMHXL (x2)
TSK gel G2000HXL
・Measurement solvent: Tetrahydrofuran ・Measurement temperature: 40℃

100 parts of the (meth)acrylic acid ester polymer obtained in the above process (in terms of solid content; the same applies hereinafter) and trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, product name: "Coronate") as an isocyanate crosslinking agent. (registered trademark) L"), 0.30 parts of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM403") as a silane coupling agent, and ultraviolet curing 7.5 parts of ethoxylated isocyanuric acid triacrylate (manufactured by Shin Nakamura Chemical Co., Ltd., product name "A-9300") as a chemical compound, and 2-methyl-1-(4-methylthiophenyl)-2 as a photopolymerization initiator. - 0.5 part of morpholinopropan-1-one (manufactured by BASF: Irgacure (registered trademark) 907), stirred thoroughly, and diluted with ethyl acetate to prepare adhesive composition (1). A coating solution was obtained.

An applicator is applied to the release-treated surface (release layer surface) of the separator (SP-PLR382190 manufactured by Lintec Corporation) to a thickness of 5 μm after drying (measured with a digital micrometer "MH-15M" manufactured by Nikon Corporation). After applying the coating solution of adhesive composition (1), it was dried at a temperature of 100°C for 1 minute, and another layer was applied on the side of the dried coating layer opposite to the side to which the separator was attached. One separator (manufactured by Lintec Corporation: SP-PLR381031) was laminated. This coating layer is irradiated with ultraviolet rays (irradiation intensity 500 mW/cm ² , cumulative light amount 500 mJ/cm ² ) through the release sheet using an ultraviolet irradiation device with a belt conveyor (manufactured by Fusion UV Systems, the lamp uses a D bulb). Then, an adhesive layer (1) was formed to obtain an adhesive layer (1) with separators on both sides.

When the water vapor permeability of the adhesive layer (1) was measured using a water vapor permeability measuring device (Lyssy-L80-5000 manufactured by Lyssy) under conditions of a temperature of 40°C and a relative humidity of 90%, it was found to be 7600 g. /( ^m2・24h).

When the storage elastic modulus G' of the adhesive layer (1) was measured, it was found to be 125,000 Pa at a temperature of 25°C. The storage modulus G' was measured by laminating a plurality of adhesive layers (1) to a thickness of 0.2 mm (measured with a digital micrometer "MH-15M" manufactured by Nikon Corporation), and then a layer with a diameter of 8 mm. A cylindrical body punched out was used as a measurement sample, and the measurement sample was subjected to the following conditions using a torsional shear method using a viscoelasticity measuring device (manufactured by Physica, MCR300) in accordance with JIS K7244-6. It was measured with
〔Measurement condition〕
Normal force FN: 1N
Distortion γ: 1%
Frequency: 1Hz
Temperature: 25℃

The glass transition temperature of the adhesive layer (1) was measured using the following procedure and was found to be 25° C. or lower. First, 5 mg of the adhesive layer (1) was collected, placed in an aluminum press-lid type container, and pressed and sealed to prepare a measurement sample. The container containing the sample for measurement was set in a differential scanning calorimeter (DSC) [EXSTAR-6000 DSC6220 sold by SII Nanotechnology Co., Ltd.], and heated to 20°C while purging with nitrogen gas. Lower the temperature from -60°C to -60°C, hold for 1 minute after reaching -60°C, then raise the temperature from -60°C to 150°C at a rate of 10°C/min, and once it reaches 150°C, immediately raise the temperature to 20°C. The temperature has dropped. Then, from the DSC curve when the temperature is raised from -60°C to 150°C, the midpoint glass transition temperature specified in JIS K 7121-1987 "Method for measuring the transition temperature of plastics" is determined, and this is determined from the DSC curve when the temperature is raised from -60°C to 150°C. It was taken as the glass transition temperature of layer (1).

[Preparation of adhesive layers (2) to (4)]
In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen introduction tube, 97.0 parts of n-butyl acrylate, 1.0 part of acrylic acid, and 0.5 part of 2-hydroxyethyl acrylate were added. , 200 parts of ethyl acetate, and 0.08 part of 2,2'-azobisisobutyronitrile were charged, and the air in the reaction vessel was replaced with nitrogen gas. The reaction solution was heated to 60°C while stirring under a nitrogen atmosphere, reacted for 6 hours, and then cooled to room temperature. When the weight average molecular weight of a part of the obtained solution was measured according to the above-described procedure, it was confirmed that a (meth)acrylic acid ester polymer of 1.8 million was produced.

100 parts of the (meth)acrylic acid ester polymer obtained in the above process (solid content equivalent; the same applies hereinafter) and trimethylolpropane-modified tolylene diisocyanate (manufactured by Tosoh Corporation, product name: "Coronate") as an isocyanate crosslinking agent. (registered trademark) L") and 0.30 part of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM403") as a silane coupling agent. A coating solution of adhesive composition (2) was obtained by sufficiently stirring and diluting with ethyl acetate.

The release-treated surface (release layer surface) of the separator (manufactured by Lintec Corporation: SP-PLR382190) is coated with an applicator to a dry thickness of 15 μm (adhesive layer (2)) and 25 μm (adhesive layer (3)), respectively. , and 35 μm (adhesive layer (4)) (the thickness was measured with a digital micrometer “MH-15M” manufactured by Nikon Corporation), and a coating solution of the adhesive composition (2) was applied. After that, it was dried at a temperature of 100°C for 1 minute, and another separator (SP-PLR381031, manufactured by Lintec Corporation) was attached to the side of the dried coating layer opposite to the side to which the separator was attached. Then, adhesive layers (2) to (4) with double-sided separators were obtained.

When the storage modulus G' of the adhesive layers (2) to (4) was measured according to the above-described procedure, they were all 25,500 Pa at a temperature of 25°C. Furthermore, when the glass transition temperatures of the adhesive layers (2) to (4) were measured using the above-described procedure, they were all 25° C. or lower.

[Example 1]
(Production of retardation laminate (1) with base material layer)
The first liquid crystal retardation layer side (1) of the first liquid crystal retardation layer with a base material layer (1) obtained above and the second liquid crystal retardation layer of the second liquid crystal retardation layer with a base material layer (1) Corona treatment was applied to each side (1). The corona-treated surfaces are pasted together through the adhesive layer (1) obtained by peeling off the separator of the adhesive layer (1) with a double-sided separator, and the retardation laminate (1) with a base material layer (position A retarder (1)) was obtained. The retardation laminate (1) with a base material layer consists of a second base layer (COP film)/first liquid crystal retardation layer (1) (alignment film/cured material layer (1-1))/second lamination. It has a layer structure of layer (adhesive layer (1))/second liquid crystal retardation layer (1) (cured material layer (2-1)/alignment film)/second base layer (TAC film).

(Production of optical laminate (1) with separator)
Corona treatment was applied to the overcoat layer side of the polarizing plate (1) with a base material layer cut out from the long polarizing plate (1) with a base material layer obtained above so that the longitudinal direction of the elongated sheet becomes the long side. I did it. Next, the second base layer (COP film) on the first liquid crystal retardation layer (1) side of the base layer-attached retardation laminate (c1) obtained above was peeled off, and the peeled surface was subjected to corona treatment. . Along with the peeling of the second base layer, the alignment film also peeled off. The corona-treated surfaces were laminated together with the active energy ray-curable composition (1) prepared above interposed therebetween so that their long sides overlapped with each other. Next, ultraviolet rays are irradiated from the polarizing plate with base material layer (1) side so that the cumulative amount of UVA light is about 350 mJ/cm ² (measured value with UV Power Puck II, manufactured by Fusion UV), and active energy rays are applied. The curable composition (1) was cured to form a first bonding layer, which is a cured product layer. The thickness of the first bonding layer was 2 μm.

After that, one separator is peeled off from the adhesive layer (2) with double-sided separators on the surface exposed by peeling off the second base layer (TAC film) of the second liquid crystal retardation layer (1) with a base layer. The exposed adhesive layer (2) was bonded together, and the single-sided release-treated PET film on the base layer-attached polarizing plate (1) side was peeled off to obtain a separator-attached optical laminate (1). Along with the peeling of the second base layer, the alignment film also peeled off. The optical laminate with a separator (1) consists of a protective layer (HC layer)/liquid crystal polarizer (photo alignment film (1)/cured material layer)/overcoat layer/first lamination layer (active energy ray curable composition). (cured material layer (1)) / first liquid crystal retardation layer (1) (cured material layer (1-1)) / second lamination layer (adhesive layer (1)) / second liquid crystal retardation layer ( 1) It has a layer structure of (cured material layer (2-1))/third bonding layer (adhesive layer (2))/separator.

[Example 2]
A polarizing plate with a base layer (1) and a retardation laminate with a base layer (1) are laminated via an active energy ray curable composition (2) to form an active energy ray curable composition (2). A separator was prepared in the same manner as in Example 1, except that ultraviolet rays were irradiated so that the cumulative amount of UVB light was approximately 250 mJ/cm ² (measured by UV Power Puck II, manufactured by Fusion UV). An attached optical laminate (2) was obtained.

[Example 3]
(Production of retardation laminate (3) with base material layer)
The first liquid crystal retardation layer side (2) of the first liquid crystal retardation layer with a base material layer (2) obtained above and the second liquid crystal retardation layer of the second liquid crystal retardation layer with a base material layer (2) Corona treatment was applied to each side (2). On this corona-treated surface, the adhesive layer (1) obtained by peeling off the separator of the double-sided separator-equipped adhesive layer (1) is laminated, and the retardation laminate (3) with a base material layer (retardation layer ( 3)) was obtained. The retardation laminate (3) with a base material layer includes a second base layer (PET film)/first liquid crystal retardation layer (2) (photo alignment film (2)/cured material layer (1-2))/ 2nd lamination layer (adhesive layer (1)) / 2nd liquid crystal retardation layer (2) (cured material layer (2-2) / vertical alignment film) / 2nd base layer (single-side release treated PET film ) has a layered structure.

(Production of optical laminate (3) with separator)
Corona treatment was performed on the overcoat layer side of the base layer-attached polarizing plate (1) obtained above. Next, the second base layer (PET film) on the first liquid crystal retardation layer (2) side of the base layer-attached retardation laminate (3) obtained above was peeled off, and the peeled surface was subjected to corona treatment. . In peeling off the second base layer, the PET film was peeled off, and the photo-alignment film (2) remained on the cured material layer (1-2) without being peeled off. The above corona-treated surfaces were bonded together via the active energy ray-curable composition (2) prepared above. Next, ultraviolet rays are irradiated from the polarizing plate with base material layer (1) side so that the cumulative amount of UVA light is about 250 mJ/cm ² (measured value with a measuring device: UV Power Puck II manufactured by Fusion UV), and active energy rays are applied. The curable composition (2) was cured to form a first bonding layer, which is a cured product layer. The thickness of the first bonding layer was 2 μm.

Thereafter, the second base layer (one-sided release treated PET film) of the second liquid crystal retardation layer (2) with a base layer is peeled off, and one side is applied from the adhesive layer (2) with a double-sided separator to the exposed surface. The separator was peeled off and the exposed adhesive layer (2) was laminated, and the single-sided release-treated PET film on the polarizing plate with base layer (1) side was peeled off to obtain an optical laminate with a separator (3). Ta. Due to the peeling of the second base layer, the single-sided release-treated PET film was peeled off, and the vertical alignment film remained on the cured material layer (2-2) without being oriented. The optical laminate with separator (3) consists of a protective layer (HC layer)/liquid crystal polarizer (photo alignment film (1)/cured material layer)/overcoat layer/first lamination layer (active energy ray curable composition). (cured material layer (2)) / first liquid crystal retardation layer (2) (photo alignment film (2) / cured material layer (1-2)) / second bonding layer (adhesive layer (1)) / It has a layer structure of second liquid crystal retardation layer (2) (cured material layer (2-2)/vertical alignment film)/third bonding layer (adhesive layer (2))/separator.

[Examples 4 to 6]
Optical laminates (4) to (6) with separators were obtained in the same manner as in Example 3, except that those shown in Tables 2 and 3 were used as the polarizing plate with the base material layer and the third bonding layer.

[Example 7]
An optical laminate with a separator (7) was obtained in the same manner as in Example 2 except that the third bonding layer shown in Table 3 was used.

[Comparative example 1]
(Preparation of adhesive composition)
After mixing the components shown below, the mixture was defoamed to prepare a cationic polymerizable adhesive composition. The cationic polymerization initiator was blended as a 50% by mass propylene carbonate solution, and its solid content was shown.
・1,6-hexanediol diglycidyl ether (EX-212L, manufactured by Nagase ChemteX Corporation): 25 parts ・4-hydroxybutyl vinyl ether: 10 parts ・Bisphenol F type epoxy resin (EXA-830CRP, manufactured by DIC Corporation) (manufactured by San-Apro Co., Ltd.): 65 parts Cationic polymerization initiator (CPI-100P, manufactured by San-Apro Co., Ltd., 50% by mass solution): 3 parts

(Preparation of retardation laminate (c1) with base material layer)
The first liquid crystal retardation layer with a base material layer (2) obtained above and the second liquid crystal retardation layer with a base material layer (2) are placed on the first liquid crystal retardation layer side (2) side and the second liquid crystal retardation layer side, respectively. They were laminated with the active energy ray-curable composition (1) prepared above interposed therebetween, with the retardation layer (2) side serving as the lamination surface. Next, the active energy ray-curable composition (1) is cured by irradiating ultraviolet rays from the side of the second liquid crystal retardation layer with the base material layer (2) to form a second bonding layer with a thickness of 2 μm, A retardation laminate (c1) with a base material layer (retardation body (c1)) was obtained. The retardation laminate with a base material layer (c1) is composed of a second base layer (PET film)/first liquid crystal retardation layer (2) (photo alignment film (2)/cured material layer (1-2))/ Second bonding layer (cured layer of active energy ray curable composition (1))/Second liquid crystal retardation layer (2) (cured layer (2-2)/vertical alignment film)/Second base material It has a layered structure (one-sided release-treated PET film).

(Preparation of optical laminate with separator (c1))
Corona treatment was performed on the overcoat layer side of the base layer-attached polarizing plate (1) obtained above. Next, the second base layer (PET film) on the first liquid crystal retardation layer (2) side of the base layer-attached retardation laminate (c1) obtained above was peeled off, and the peeled surface was subjected to corona treatment. . In peeling off the second base layer, the PET film was peeled off, and the photo-alignment film (2) remained on the cured material layer (1-2) without being peeled off. The above-mentioned corona-treated surfaces were bonded together via the adhesive layer (1) obtained by peeling off the separator of the double-sided separator-equipped adhesive layer (1) to obtain a laminate structure (c1).

A cycloolefin polymer (COP) film (manufactured by Nippon Zeon Co., Ltd., ZF14) with a thickness of 13.00 μm and one-sided mold release treatment on the polarizing plate (1) side with a base material layer of the laminated structure (c1) obtained above. The PET film was peeled off and the exposed surface was subjected to corona treatment. The corona-treated surfaces were bonded together via the adhesive composition prepared above, and an exposure amount of 500 mJ/cm ² (365 nm standard) was applied using an ultraviolet irradiation device (SPOT CURE SP-7, manufactured by Ushio Inc.). ) was irradiated with ultraviolet rays to form an adhesive layer with a thickness of 2.00 μm. Ultraviolet light was irradiated from the COP film side. Thereafter, on the surface of the second liquid crystal retardation layer with a base layer (2) that was exposed by peeling off the second base layer, apply the adhesive that was exposed by peeling off one separator from the adhesive layer (2) with double-sided separators. The agent layer (2) was laminated to obtain an optical laminate with a separator (c1). Due to the peeling of the second base layer, the single-sided release-treated PET film was peeled off, and the vertical alignment film remained on the cured material layer (2-2) without being oriented. The optical laminate with separator (c1) consists of a protective layer (COP film/adhesive layer/HC layer)/liquid crystal polarizer (photo alignment film (1)/cured material layer)/overcoat layer/first laminating layer ( Adhesive layer (1))/first liquid crystal retardation layer (2) (photoalignment film (2)/cured material layer (1-2))/second bonding layer (active energy ray curable composition (1) ) / second liquid crystal retardation layer (2) (cured material layer (2-2) / vertical alignment film) / third laminating layer (adhesive layer (2)) / separator layer structure have

[Comparative example 2]
Instead of the COP film, a triacetyl cellulose (TAC) film (KC2CT, manufactured by Konica Minolta, Inc.) with a thickness of 20.00 μm was used, and the single-sided release-treated PET film was peeled from this TAC film and the laminated structure (c1). An optical laminate with a separator (c2) was obtained by following the procedure for producing an optical laminate with a separator (c2) in Comparative Example 1, except that the exposed surface was laminated with the TAC film side and UV rays were irradiated from the TAC film side. .

[Comparative example 3]
The overcoat layer side of the elongated polarizing plate (1) with a base material layer cut out from the elongated polarizing plate (1) with a base material layer obtained above so that the longitudinal direction of the elongated sheet becomes the long side. Corona treatment was carried out. Next, the second base layer (COP film) on the first liquid crystal retardation layer (1) side of the base layer-attached retardation laminate (1) obtained by the procedure of Example 1 was peeled off, and corona was applied to the peeled surface. processed. Along with the peeling of the second base layer, the alignment film also peeled off. The above-mentioned corona-treated surfaces were pasted together with the long sides overlapping each other through the adhesive layer (1) obtained by peeling off the separator of the double-sided separator-equipped adhesive layer (1).

After that, one separator is peeled off from the adhesive layer (3) with double-sided separators on the surface exposed by peeling off the second base layer (TAC film) of the second liquid crystal retardation layer (1) with a base layer. The exposed adhesive layer (3) was bonded together, and the single-sided release-treated PET film on the base layer-attached polarizing plate (1) side was peeled off to obtain a separator-attached optical laminate (c3). Along with the peeling of the second base layer, the alignment film also peeled off. The optical laminate with separator (c3) consists of a protective layer (HC layer)/liquid crystal polarizer (photo alignment film (1)/cured material layer)/overcoat layer/first bonding layer (adhesive layer (1)) /First liquid crystal retardation layer (1) (cured material layer (1-1))/Second laminating layer (adhesive layer (1))/Second liquid crystal retardation layer (1) (cured material layer (2) -1))/third bonding layer (adhesive layer (3))/separator.

[Comparative example 4]
Corona treatment was performed on the overcoat layer side of the base layer-attached polarizing plate (1) obtained above. Next, the second base layer (PET film) on the first liquid crystal retardation layer (2) side of the base layer-attached retardation laminate (3) obtained by the procedure of Example 3 was peeled off, and corona was applied to the peeled surface. processed. In peeling off the second base layer, the PET film was peeled off, and the photo-alignment film (2) remained on the cured material layer (1-2) without being peeled off. The above corona-treated surfaces were bonded together via the adhesive layer (1) obtained by peeling off the separator of the double-sided separator-equipped adhesive layer (1).

Thereafter, the second base layer (single-side release treated PET film) of the second liquid crystal retardation layer (2) with a base layer is peeled off, and one side is applied from the adhesive layer (3) with a double-sided separator to the exposed surface. The separator is peeled off and the exposed adhesive layer (3) is laminated, and the single-sided release-treated PET film on the polarizing plate with base layer (1) side is peeled off to obtain an optical laminate with a separator (c4). Ta. Due to the peeling of the second base layer, the single-sided release-treated PET film was peeled off, and the vertical alignment film remained on the cured material layer (2-2) without being oriented. The optical laminate with separator (c4) consists of a protective layer (HC layer)/liquid crystal polarizer (photo alignment film (1)/cured material layer)/overcoat layer/first bonding layer (adhesive layer (1)) /First liquid crystal retardation layer (2) (photo alignment film (2)/cured material layer (1-2))/Second laminating layer (adhesive layer (1))/Second liquid crystal retardation layer (2) ) (cured material layer (2-2)/vertical alignment film)/third bonding layer (adhesive layer (3))/separator layer structure.

[Comparative example 5]
The first liquid crystal retardation layer with a base material layer (2) obtained above and the second liquid crystal retardation layer with a base material layer (2) are placed on the first liquid crystal retardation layer side (2) side and the second liquid crystal retardation layer side, respectively. They were laminated with the active energy ray-curable composition (2) interposed therebetween, with the retardation layer (2) side serving as the lamination surface. Next, UV rays are irradiated from the side of the second liquid crystal retardation layer with a base material layer (2) to cure the active energy ray-curable composition (2) to form a second bonding layer with a thickness of 2 μm, A retardation laminate (c5) with a base material layer was obtained.

Same as Comparative Example 4 except that the retardation laminate with a base material layer (c5) was used instead of the retardation laminate with a base material layer (3), and the material shown in Table 5 was used as the third bonding layer. Then, an optical laminate with a separator (c5) was obtained.

[Comparative example 6]
Comparative example except that the laminate structure (c1) produced by the procedure of Comparative example 1 was used instead of the retardation laminate with base material layer (3), and the material shown in Table 5 was used as the third bonding layer. An optical laminate with a separator (c6) was obtained in the same manner as in 4.

[Calculation of adhesive layer thickness ratio (Dt/D1)]
The distance from the surface of the protective layer opposite to the liquid crystal polarizer side to the surface of the third laminating layer opposite to the second liquid crystal retardation layer side is defined as D1 (Figure 1), and the first laminating layer The thickness ratio [%] (=Dt/D1 x 100) was calculated as the total thickness Dt of the layers (adhesive layer) whose Tg is 25 ° C. or less among the second bonding layer and the third bonding layer. . The cured product layer of the active energy ray-curable composition (1) and the cured product layer of the active energy ray-curable composition (2) were both measured using the above-described procedure, and both were found to have a temperature of over 25°C. In the example, the total thickness Dt is the total thickness D2 of the thickness of the second bonding layer and the thickness of the third bonding layer. The results are shown in Tables 2 to 5.

[Moist heat test]
The optical laminate with a separator obtained above was cut into a size of 30 mm x 30 mm, and the third lamination layer exposed by peeling off the separator was covered with alkali-free glass (manufactured by Corning, EAGLE XG (registered trademark), thickness 0). .7 mm) was laminated to prepare a test sample. The test sample was placed in a spectrophotometer (manufactured by JASCO Corporation, V7100) with the protective layer side facing the incident surface, and the visibility correction transmittance of transmitted light parallel to the transmission axis direction of the liquid crystal polarizer was measured. , this was defined as the initial visibility correction transmittance Ty _p 0.

Subsequently, the test sample was placed in an oven set at a temperature of 65° C. and a relative humidity of 90%, and a moist heat test was performed in which it was left standing for 500 hours, and the test sample was taken out from the oven. After that, the test sample was allowed to stand in an environment with a temperature of 25°C and a relative humidity of 55% for 6 hours, and the transmitted light parallel to the transmission axis direction of the liquid crystal polarizer was applied to the test sample in the same manner as described above. The visibility-corrected transmittance of the sample was measured, and this was defined as the visibility-corrected transmittance Ty _p 1 after the wet heat test. The difference ΔTy _p (=Ty _p 1 - Ty _p 0) between the luminous efficiency corrected transmittance Ty _p 1 after the moist heat test and the initial luminous efficiency corrected transmittance Ty _p 0 was calculated and evaluated based on the following criteria.
A: The difference ΔTy _p was 0% or more and less than 1%.
B: The difference ΔTy _p was 1% or more and less than 3%.
C: The difference ΔTy _p was 3% or more.

[Scratch test]
Using the optical laminate with a separator obtained above, one hour after forming the second bonding layer, and forming the first bonding layer between the polarizing plate and the first liquid crystal retardation layer. Thirty minutes later, a test sample was prepared using the procedure described in the impact resistance test above. A load of 5 N was applied to the surface of the optical laminate side (surface of the protective layer side) of the test sample using a scratch type hardness tester (manufactured by Eriksen AG, Germany, model 318, ball diameter 0.75 mm), and this load was applied. while moving on the surface at a speed of 1 cm/s. Then, under the illuminance and reflection conditions of the fluorescent lamp shown in Table 1, the protective layer side of the optical laminate of the test sample was observed from the front and diagonally, and depending on the presence or absence of visible scratches, the following Evaluation was performed according to the criteria shown in Table 1. The results are shown in Tables 2-5. Note that the following evaluations A to D are all within an acceptable range for practical use.

[Flexibility test (1): Evaluation of reflective hue]
From the optical laminate with a separator obtained above, a small rectangular test piece with a long side of 110 mm and a short side of 10 mm was cut out using a super cutter so that the absorption axis of the liquid crystal polarizer was parallel to the long side. .

As shown in FIG. 2(a), a bending tester having two independently movable jigs 501 and 502 is installed so that the protective layer side of the test piece 500 is on the inside and the bending axis is parallel to the short side. With the test piece 500 bent, the long side ends of the test piece 500 are fixed to jigs 501 and 502 with adhesive tape, respectively, and the jigs are fixed so that the interval L between the jigs 501 and 502 is 70 mm. The positions of 501 and 502 were adjusted. Thereafter, as shown in FIG. 2(b), the jig 501 is moved in the direction of arrow A so that the interval L is 4.0 mm (bending radius 2R) to further bend the test piece 500, and then The series of operations of moving the tool 501 in the direction of arrow B and returning the interval L to 70 mm is counted as one time, and the above operation is repeated 100,000 times in an environment of a temperature of 25° C. and a relative humidity of 55%. Repeated times. The moving speed of the jig 501 was 1.32 m/sec, and the time required to repeat the above operation of changing the interval L 100,000 times was 27.8 hours. After repeating the above operation 100,000 times, the test piece 500 is taken out from the bending tester, the bending of the test piece 500 is released, the separator is peeled off to expose the third bonding layer, and the exposed surface is covered with an aluminum vapor-deposited film. The aluminum vapor-deposited film side of a coated PET film (manufactured by Toray Film Processing Co., Ltd., trade name "#50 DMS (X42)") was bonded together to form a bonded body. The presence or absence of unevenness in the reflected hue in the portion along the bending axis was checked when the bonded body was viewed from the front from the protective layer side, and evaluated based on the following criteria. The results are shown in Tables 2-5.
A: No unevenness in reflected hue was visually recognized.
B: Unevenness in reflected hue was not noticeable but was visible.
C: The unevenness of the reflected hue is noticeable.

[Flexibility test (2): Evaluation of peeling of third lamination layer]
From the optical laminate with a separator obtained above, a small rectangular piece with a long side of 110 mm and a short side of 10 mm was cut out using a super cutter so that the absorption axis of the liquid crystal polarizer was parallel to the long side. The separator is peeled off from this small piece to expose the third bonding layer, and the aluminum vapor-deposited film surface of the PET film with aluminum vapor-deposited film (manufactured by Toray Film Kako Co., Ltd., trade name "#50 DMS (X42)") is attached to the exposed surface. The sides were pasted together to form a test piece.

Except for using this test piece, the operation of varying the distance L was repeated 100,000 times under the conditions described in Flexibility Test (1) using the bending tester used in Flexibility Test (1). After repeating the above operation 100,000 times, release the bending of the test piece taken out from the bending tester, check the presence or absence of peeling of the third bonding layer from the front view from the protective layer side of the test piece, and follow the criteria below. It was evaluated by When peeling occurs in the third laminating layer, the peeling occurs from the edge of the test piece, so the size of the peeling is from the edge of the test piece where peeling occurred to the end of the peeled test piece. This is the shortest distance to the opposite side. The results are shown in Tables 2 to 5.
A: Peeling of the third bonding layer was not observed.
B: Peeling of the third bonding layer with a size of less than 100 μm was observed.
C: Peeling of the third bonding layer with a size of 100 μm or more was confirmed.

[Workability test]
A surface protection film was pasted on the surface of the protective layer side of the optical laminate with a separator obtained above, and this was cut into a rectangle so that the absorption axis of the liquid crystal polarizer was +45° with respect to the long side. , which was used as a sample for processing. The surface protection film is a film that is releasably attached to the protective layer and can be peeled off while maintaining the shape of the optical laminate with a separator.

In the workability test, polishing was performed using an end face processing device, and the presence or absence of cracks in the first liquid crystal retardation layer and the second liquid crystal retardation layer that occurred on the polished end face was observed. The end face processing device will be explained based on FIG. 3. FIG. 3 is a schematic perspective view schematically showing the end face processing device. In the end face processing apparatus, the laminate W of the sample for processing can be polished using an apparatus equipped with a support section 50 and two rotary tools 60. The support part 50 is for pressing the laminate W from above and below and fixing it so that the laminate W itself does not move during the polishing process and the stacked samples for processing do not shift. The rotary tool 60 is for polishing the end face of the laminate W, and can rotate around the rotation axis R. The support section 50 includes a flat substrate (a means for moving the laminate W) 51; a gate-shaped frame 52 disposed on the substrate 51; and a rotary table rotatable about a central axis disposed on the substrate 51. 53; It may be provided with a cylinder 54 which is provided in a position facing the rotary table 53 in the frame 52 and is movable up and down. The laminate W is sandwiched and fixed between the rotary table 53 and the cylinder 54 via a jig 55. Two rotary tools 60 are provided on both sides of the substrate 51 facing each other. The rotary tool 60 is movable in a direction along the rotation axis R according to the size of the laminate W, and the substrate 51 is movable so as to pass between the two rotary tools 60. In the polishing process, the laminate W is fixed to the support part 50, the position of the rotary tool 60 in the direction of the rotation axis is adjusted appropriately, and the rotary tool 60 is rotated about the rotation axis R of the laminate W while laminating The substrate 51 is moved so that the object W passes between the rotating tools 60 facing each other. As a result, while moving the rotary tool 60 relative to the laminate W in a direction parallel to the end surface of the laminate W and perpendicular to the lamination direction, the polishing blade of the rotary tool 60 is moved to the laminate. A polishing process can be performed in which the exposed end faces of the W are brought into contact with each other and these end faces are polished.

Using the end face processing apparatus shown in FIG. 3, the processing sample was polished into a rectangle of 120 mm x 50 mm (in plan view) under the polishing conditions shown below.
Number of laminated samples for processing when performing polishing: 100 Clamp pressure to press the laminate W to be polished from both sides: 0.1 MPa
Relative movement speed between laminate W and rotary tool 60: 3500 mm/min
Rotation speed of rotary tool 60: 5400 rpm
Feed pitch (value obtained by dividing the relative movement speed by the rotation speed of the rotary tool 60 and the number of times the polishing blade contacts the end surface when the rotary tool 60 rotates once): 0.32 mm
Polishing blade entry direction: The direction in which the polishing blade enters from the separator side toward the surface protection film side of the sample for processing.

Peel off the separator from the processing sample after polishing and attach the aluminum vapor-deposited film surface of the PET film with aluminum vapor-deposited film (manufactured by Toray Film Processing Co., Ltd., product name "#50 DMS (X42)") to the exposed third bonding layer. The sides were bonded together to form a bonded body. The bonded body was evaluated from the protective layer side using an optical microscope VHX-1000 (manufactured by Keyence Corporation) according to the following criteria. The size of the crack was defined as the diameter of a perfect circle inscribing the crack in a plan view of the protective layer. The results are shown in Tables 2-5.
A: No cracks were observed.
B: Cracks with a size of less than 200 μm were observed.
C: Cracks with a size of 200 μm or more were observed.

Reference Signs List 1 optical laminate, 10 polarizing plate, 11 protective layer, 15 liquid crystal polarizer, 18 overcoat layer (second protective layer), 21 first liquid crystal retardation layer, 22 second liquid crystal retardation layer, 31 first lamination layer, 32 second bonding layer, 33 third bonding layer, 38 separator, 50 support portion, 51 substrate, 52 frame, 53 rotary table, 54 cylinder, 55 jig, 60 rotary tool, 500 test piece, 501,502 Jig, B polishing blade, R rotating shaft, W laminate.

Claims (5)

An optical laminate comprising a protective layer, a liquid crystal polarizer, a first bonding layer, a first liquid crystal retardation layer, a second bonding layer, a second liquid crystal retardation layer, and a third bonding layer in this order,
The liquid crystal polarizer includes a cured layer of a first liquid crystal composition containing a dichroic dye and a polymerizable liquid crystal compound,
The first liquid crystal retardation layer and the second liquid crystal retardation layer both include a cured layer of a second liquid crystal composition containing a polymerizable liquid crystal compound,
The first bonding layer is a cured product layer of an active energy ray-curable composition,
The optical laminate, wherein the second bonding layer and the third bonding layer both have a glass transition temperature of 25° C. or lower. The optical laminate according to claim 1, wherein the first bonding layer is a cured product layer of a radically polymerizable adhesive composition. The optical laminate according to claim 1 or 2, wherein each of the protective layer, the liquid crystal polarizer, the first liquid crystal retardation layer, and the second liquid crystal retardation layer has a thickness of less than 20.0 μm. When the distance from the surface of the protective layer opposite to the liquid crystal polarizer side to the surface of the third bonding layer opposite to the second liquid crystal retardation layer side is D1 [μm],
The optical laminate according to claim 1 or 2, wherein a total thickness D2 [μm] of the second bonding layer and the third bonding layer is 40% or more and 70% or less of D1. The optical laminate according to claim 1 or 2, further comprising an overcoat layer that covers the surface of the liquid crystal polarizer on the first bonding layer side.

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