JP2020149036A - Circularly polarizing plate, and circularly polarizing plate with glass plate - Google Patents

Abstract

To provide a circularly polarizing plate which exhibits good optical characteristics even after going through a wet heat test, and to provide a circularly polarizing plate with a glass plate.SOLUTION: A circularly polarizing plate is provided, comprising a linearly polarizing layer, an adhesive layer, and a λ/4 retardation layer laminated in the described order, where the linearly polarizing layer contains a cured product of a polymerizable liquid crystal compound and a dichroic pigment, and the λ/4 retardation layer contains a cured product of a polymerizable liquid crystal compound. The adhesive layer exhibits a moisture permeability of 100 g/(m2/24hr) or less at a temperature of 40°C and humidity of 90%RH.SELECTED DRAWING: Figure 1

Description

The present invention relates to a circularly polarizing plate and a circularly polarizing plate with a glass plate.

The linear polarizing layer, the circular polarizing plate, and the like are attached to an image display element such as a liquid crystal cell or an organic EL element, and incorporated into a display device such as a liquid crystal display device or an organic EL display device. The linearly polarizing layer incorporated in such a display device includes a polyvinyl alcohol-based resin film in which a dichroic dye such as iodine is adsorbed and oriented, and a cured product of a polymerizable liquid crystal compound in which the dichroic dye is oriented. Things are known. Further, as the retardation layer included in the circularly polarizing plate, a resin film having a retardation or a layer formed by using a polymerizable liquid crystal compound is known.

In recent years, display devices have also been used as display devices for outdoor and in-vehicle use, and durability in more harsh environments is required. Therefore, the linear polarizing layer and the circular polarizing plate incorporated in the display device are also required to have durability in a harsher environment. For example, Patent Document 1 describes a laminated body having improved durability in a high temperature environment by providing moisture barrier layers on both sides of a linear polarizing plate having a low water content.

Korean Publication No. 10-2018-003114

An object of the present invention is to provide a circularly polarizing plate having good optical characteristics even after a moist heat test and a circularly polarizing plate with a glass plate.

The present invention provides the following circularly polarizing plate and circularly polarizing plate with a glass plate.
[1] A circular polarizing plate having a linear polarizing layer, a bonded layer, and a λ / 4 retardation layer in this order.
The linearly polarizing layer contains a cured product of a polymerizable liquid crystal compound and a dichroic dye.
The λ / 4 retardation layer contains a cured product of a polymerizable liquid crystal compound, and contains a cured product.
The temperature 40 ° C. lamination layer, the moisture permeability and humidity 90% RH is 100g ^/ (m 2 · 24hr) or less, the circularly polarizing plate.
[2] The circular polarizing plate according to [1], wherein the λ / 4 retardation layer has anti-wavelength dispersibility.
[3] The circularly polarizing plate according to [1] or [2], wherein the bonding layer is formed from a pressure-sensitive adhesive composition.
[4] The circularly polarizing plate according to [3], wherein the pressure-sensitive adhesive composition contains a rubber-based polymer.
[5] The circular polarizing plate according to any one of [1] to [4], further having an overcoat layer on one side or both sides of the linearly polarizing layer.
[6] The circular polarizing plate according to any one of [1] to [5], further having a base material layer on the side of the linearly polarizing layer opposite to the bonded layer side.
[7] The circular polarizing plate according to [6], further having a hard coat layer on the side of the base material layer opposite to the linearly polarized light layer side.
[8] The circular polarizing plate according to any one of [1] to [7], which is for in-vehicle use.
[9] A circularly polarizing plate with a glass plate having glass plates on both sides of the circularly polarizing plate according to any one of [1] to [8].

The circularly polarizing plate of the present invention can have good optical characteristics even after a moist heat test. Specifically, in the circularly polarizing plate of the present invention, the phase difference value of the circularly polarizing plate is unlikely to change even after the moist heat test, and the reflectance is unlikely to change when the circularly polarizing plate is placed on the reflector.

It is the schematic sectional drawing which shows an example of the circular polarizing plate of this invention schematically. It is the schematic cross-sectional view which shows typically another example of the circular polarizing plate of this invention. It is the schematic cross-sectional view which shows typically another example of the circular polarizing plate of this invention. It is the schematic cross-sectional view which shows typically another example of the circular polarizing plate of this invention. It is the schematic sectional drawing which shows an example of the circularly polarizing plate with a glass plate of this invention schematically.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In all the drawings below, the scales are adjusted appropriately to make each component easier to understand, and the scale of each component shown in the drawings does not necessarily match the scale of the actual component.

<Circular polarizing plate>
FIG. 1 is a schematic cross-sectional view schematically showing an example of the circularly polarizing plate 11 of the present embodiment. As shown in FIG. 1, the circular polarizing plate 11 has a linear polarizing layer 33, a bonding layer 36, and a λ / 4 retardation layer 38 in this order. The bonding layer 36 is a pressure-sensitive adhesive layer formed by using the pressure-sensitive adhesive composition or an adhesive layer formed by using the pressure-sensitive adhesive composition. In the circular polarizing plate 11 shown in FIG. 1, the bonding layer 36 is provided on the linearly polarized light layer 33 and the λ / 4 retardation layer 38, and the linearly polarized light layer 33 and the λ / 4 retardation layer are bonded together. The case is shown as an example.

The linearly polarizing layer 33 contains a cured product of the polymerizable liquid crystal compound and a dichroic dye, and the dichroic dye is dispersed and oriented in the cured product of the polymerizable liquid crystal compound. The λ / 4 retardation layer 38 contains a cured product of a polymerizable liquid crystal compound. Temperature 40 ° C. of the bonding layer 36, the moisture permeability and humidity 90% RH is 100g ^/ (m 2 · 24hr) or less. The moisture permeability can be measured by the method described in Examples.

In the present specification, the laminated layer having the above-mentioned moisture permeability refers to a layer existing between the linearly polarized light layer and the λ / 4 retardation layer, and is between the linearly polarized light layer and the λ / 4 retardation layer. When there are a plurality of bonded layers arranged apart from each other, it means the bonded layer existing on the side closest to the λ / 4 retardation layer. When the moisture permeability of the bonded layer existing on the side closest to the λ / 4 retardation layer is within the above range, good optical characteristics can be easily maintained even after the moist heat test. Further, the moisture permeability of the bonded layer means the moisture permeability of the entire multilayer structure in the case of a multilayer structure having two or more layers in which the bonded layers are in direct contact with each other.

The circularly polarizing plate 11 of the present embodiment can prevent the optical characteristics of the circularly polarizing plate 11 from deteriorating even when the moist heat test is performed with the glass plates bonded to both sides thereof. The above moist heat test assumes a moist heat environment where in-vehicle display devices are often exposed. Further, in the moist heat test, the glass plates arranged on both sides of the circularly polarizing plate 11 are an image display element and a touch panel that are attached to the circularly polarizing plate 11 when the circularly polarizing plate 11 is used for an in-vehicle display device or the like. , A translucent member with relatively low moisture permeability used in a front plate or the like is assumed.

In the circularly polarizing plate 11 of the present embodiment, the reason why the deterioration of the optical characteristics after the moist heat test is suppressed is presumed as follows. As described above, when the glass plates are arranged on both sides of the circularly polarizing plate 11, it is considered that the moisture is hard to be discharged to the outside of the circularly polarizing plate 11, and the water is likely to be trapped in the circularly polarizing plate 11. Be done. Therefore, in the circularly polarizing plate 11 provided with glass plates on both sides, it is presumed that the movement of moisture and the like inside the circularly polarizing plate 11 is likely to occur, and the optical characteristics are likely to be deteriorated due to this influence. Therefore, in the circularly polarizing plate 11 of the present embodiment, a bonding layer 36 having a low moisture permeability is used as the bonding layer 36 for bonding the λ / 4 retardation layer 38 to another layer. As a result, the bonding layer 36 functions as a barrier layer for moisture and the like, and the moisture between the λ / 4 retardation layer 38 and another layer such as the linearly polarized light layer 33 laminated via the bonding layer 36. Since the movement can be suppressed, it is considered that the deterioration of the optical characteristics after the moist heat test is suppressed.

Further, since the linearly polarizing layer 33 contained in the circularly polarizing plate 11 contains a cured product of a polymerizable liquid crystal compound and a dichroic dye, it is compared with the linearly polarizing layer formed by stretching a polyvinyl alcohol-based resin film. Since the amount of shrinkage in the moist heat test is small, the dimensional change is small. From this point as well, it is considered that it is easy to suppress the deterioration of the optical characteristics after the moist heat test.

The circularly polarizing plate 11 of the present embodiment can be used in a display device such as an organic EL display device. Since the circularly polarizing plate 11 has good moist heat durability as described above, it can be suitably used for an in-vehicle display device that is easily exposed to a high temperature and high humidity environment for a relatively long time. Examples of vehicle-mounted display devices include car navigation systems, instrument panels, door mirrors, rear-view mirrors, and the like.

(Modification example of circular polarizing plate)
The circularly polarizing plate of the present embodiment may have the structure shown in FIGS. 2 to 4. 2 to 4 are schematic cross-sectional views schematically showing another example of the circularly polarizing plate of the present embodiment.

The circularly polarizing plate 12 shown in FIG. 2 has a base material layer 32 on the side opposite to the bonded layer 36 side of the linearly polarizing layer 33 of the circularly polarizing plate 11 shown in FIG. Therefore, as shown in FIG. 2, the circular polarizing plate 12 has a base material layer 32, a linearly polarized light layer 33, a bonded layer 36, and a λ / 4 retardation layer 38 in this order. An orientation layer may be provided between the base material layer 32 and the linearly polarizing layer 33. The base material layer 32 may be the one used for forming the linearly polarized light layer 33, as will be described later.

The circularly polarizing plate 13 shown in FIG. 3 has an overcoat layer 34 between the linearly polarized light layer 33 and the bonded layer 36 of the circularly polarizing plate 12 shown in FIG. Therefore, the circularly polarizing plate 13 has a base material layer 32, a linear polarizing layer 33, an overcoat layer 34, a bonding layer 36, and a λ / 4 retardation layer 38 in this order. Although the circular polarizing plate 13 shown in FIG. 3 has been described by taking the case of having the base material layer 32 as an example, it may not have the base material layer 32.

The circularly polarizing plate 14 shown in FIG. 4 has a hard coat layer 31 on the side opposite to the linearly polarized light layer 33 side of the base material layer 32 of the circularly polarizing plate 13 shown in FIG. Therefore, the circularly polarizing plate 14 has a hard coat layer 31, a base material layer 32, a linear polarizing layer 33, an overcoat layer 34, a bonding layer 36, and a λ / 4 retardation layer 38 in this order. Although the circular polarizing plate 14 shown in FIG. 4 is described by taking the case where the overcoat layer 34 is provided as an example, the circular polarizing plate 14 may not have the overcoat layer 34.

The circularly polarizing plates shown in FIGS. 1 to 4 have an orientation layer on the side opposite to the bonding layer 36 side of the λ / 4 retardation layer 38 or on the bonding layer 36 side of the λ / 4 retardation layer 38. The alignment layer may be provided on the bonding layer 36 side of the linearly polarizing layer 33. Further, the circular polarizing plate that does not have the base material layer 32 may have an orientation layer on the side opposite to the bonding layer 36 side of the linearly polarizing layer 33.

The circular polarizing plate shown in FIGS. 1 to 4 may have a λ / 2 retardation layer or a positive C layer between the linearly polarizing layer 33 and the bonded layer 36. In this case, the λ / 2 retardation layer and the positive C layer are preferably bonded to the linearly polarized light layer 33 via another bonding layer different from the bonding layer 36. The other bonding layer can be a pressure-sensitive adhesive layer formed by using the pressure-sensitive adhesive composition or an adhesive layer formed by using the pressure-sensitive adhesive composition. The other bonding layer may not have the moisture permeability within the above range of the bonding layer 36, but it is preferable to have it. Further, the circularly polarizing plate shown in FIGS. 1 to 4 may have a positive C layer on the opposite side of the λ / 4 retardation layer 38 from the bonding layer 36 side via another bonding layer. .. That is, when the circularly polarizing plates shown in FIGS. 1 to 4 have a positive C layer, the positive C layer may be provided between the linearly polarized light layer 33 and the bonded layer 36, and the λ / 4 retardation layer 38 may be provided. It may be provided on the side opposite to the side of the bonding layer 36 of. When the circularly polarizing plate has a positive C layer, the λ / 4 retardation layer 38 preferably has an inverse wavelength dispersibility. The λ / 2 retardation layer and the positive C layer may contain a cured product of a polymerizable liquid crystal compound, or may be a resin film.

When the circular polarizing plate includes the λ / 4 retardation layer 38 and the positive C layer, the angle formed by the absorption axis of the linearly polarizing layer 33 and the slow axis of the λ / 4 retardation layer is 45 ° ± 10 °. It can be 45 ° ± 5 °.
When the circular polarizing plate includes the λ / 2 retardation layer and the λ / 4 retardation layer 38 in order from the side closer to the linear polarization layer 33, the absorption axis of the linear polarization layer 33 and the slow phase of the λ / 2 retardation layer The angle formed by the axis can be 15 ° ± 10 ° and can be 15 ° ± 5 °. At this time, the angle formed by the absorption axis of the linearly polarized light layer 33 and the slow axis of the λ / 4 retardation layer 38 can be 75 ° ± 10 °, and can be 75 ° ± 5 °.

<Circular polarizing plate with glass plate>
FIG. 5 is a schematic cross-sectional view schematically showing an example of the circularly polarizing plate 21 with a glass plate of the present embodiment. The circularly polarizing plate 21 with a glass plate has glass plates 41 on both sides of the circularly polarizing plate 13 shown in FIG. In the circularly polarizing plate 21 with a glass plate shown in FIG. 5, a case where glass plates 41 are provided on both sides of the circularly polarizing plate 13 is shown as an example, but the circularly polarizing plate 13 has a glass plate 41 on one side. There may be. In this case, the other surface of the circularly polarizing plate 13 may be exposed, or a resin plate or the like may be attached. The glass plate 41 can be bonded to the circular polarizing plate via the glass plate bonding layer 42. The bonding layer 42 for a glass plate is a pressure-sensitive adhesive layer formed by using the pressure-sensitive adhesive composition or an adhesive layer formed by using the pressure-sensitive adhesive composition.

The glass plate 41 provided on the visible side of the circularly polarizing plate 12 may be included in the front plate arranged on the foremost surface of the display device or the touch panel. The glass plate 41 provided on the image display element side of the circularly polarizing plate may be included in the touch panel or the image display element.

As described above, the circularly polarizing plate with a glass plate 21 has a circularly polarizing plate having good heat and humidity durability, and therefore is suitably used for an in-vehicle display device that is easily exposed to a high temperature and high humidity environment for a relatively long time. Can be done.

Hereinafter, each layer of the circularly polarizing plate and the circularly polarizing plate with a glass plate will be described.
(Lated layer)
The bonding layer 36 is a layer for bonding the λ / 4 retardation layer 38 to another layer, and may be provided directly on the λ / 4 retardation layer 38, or the λ / 4 retardation layer 38. It may be provided on a layer (alignment layer, base material layer used for forming a λ / 4 retardation layer, etc.) existing on 38 without interposing another bonding layer. The bonding layer 36 is a pressure-sensitive adhesive layer formed by using the pressure-sensitive adhesive composition or an adhesive layer formed by using the pressure-sensitive adhesive composition.

Bonding layer 36, as described above, the temperature 40 ° C., the moisture permeability and humidity 90% RH is 100g ^/ (m 2 · 24hr) or less. The moisture permeability of the bonding layer ^{36, 80g / (m 2 · 24hr} ) may be ^{less, 60g / (m 2 · 24hr} ) may be ^{less, 50g / (m 2 · 24hr} ) or less may even may be at ^40g / (m 2 · 24hr) or less, it may be ^5g / (m 2 · 24hr) or more.

The moisture permeability of the bonding layer 36 can be adjusted, for example, by adjusting the composition, thickness, etc. of the pressure-sensitive adhesive composition and the adhesive composition constituting the bonding layer 36.

When the bonding layer 36 is a pressure-sensitive adhesive layer, the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer is not particularly limited as long as it can satisfy the above-mentioned moisture permeability. Examples of the pressure-sensitive adhesive composition include rubber-based polymers, (meth) acrylic-based polymers, urethane-based polymers, polyester-based polymers, silicone-based polymers, polyvinyl ether-based polymers, polyvinyl alcohol-based polymers, polyolefin-based polymers, and vinyl alkyl ether-based. Any polymer containing a polymer, a polyvinylpyrrolidone-based polymer, a poly (meth) acrylamide-based polymer, a cellulose-based polymer, or the like as a main component may be used. In the present specification, the main component means a component containing 50% by mass or more of the total solid content of the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition may be an active energy ray-curable type or a thermosetting type. As the pressure-sensitive adhesive composition, a rubber-based polymer is preferable. The above-mentioned "(meth) acrylic" means "at least one of acrylic and methacrylic". The same applies to the notation such as "(meth) acrylate".

As rubber-based polymers, natural rubber; polyisobutylene rubber (PIB), isoprene rubber (IR), isobutylene-isoprene rubber (IIR), normal butylene-isobutylene copolymer rubber, butadiene rubber (BR), chloroprene rubber (CR) , Acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), styrene-isoprene rubber (SIR), styrene-isoprene-styrene block copolymer rubber (SIBS), styrene-ethylene-butylene-styrene block copolymer Rubber (SEBS), styrene-ethylene-propylene-styrene block copolymer rubber (SEPS), styrene-butadiene-styrene block copolymer rubber (SBS), styrene-ethylene-propylene block copolymer rubber (SEP), etc. Synthetic rubber and the like can be mentioned. As the rubber-based polymer, polyisobutylene rubber (PIB), isobutylene-isoprene rubber (IIR), normal butylene-isobutylene copolymer rubber are preferable, and polyisobutylene rubber (PIB) is more preferable.

As a (meth) acrylic polymer, one kind of (meth) acrylic acid ester such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Alternatively, a polymer or copolymer containing two or more kinds of monomers is preferably used. The base polymer is preferably copolymerized with a polar monomer. Examples of the polar monomer include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl (). Examples thereof include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group and the like, such as meta) acrylate.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by being irradiated with active energy rays such as ultraviolet rays and electron beams, and has adhesiveness even before irradiation with active energy rays. It is a pressure-sensitive adhesive composition having the property of being able to adhere to an adherend such as, etc., and being cured by irradiation with active energy rays to adjust the adhesion force. The active energy ray-curable pressure-sensitive adhesive composition is preferably an ultraviolet-curable type. The active energy ray-curable pressure-sensitive adhesive composition further contains an active energy ray-polymerizable compound in addition to the base polymer and the cross-linking agent. Further, if necessary, a photopolymerization initiator, a photosensitizer, or the like may be contained.

Adhesive compositions are polymers in addition to polymers; tackifiers, softeners, fillers (metal powders and other inorganic powders, etc.), antioxidants, UV absorbers, dyes, pigments, colorants, antifoaming agents. , Corrosion inhibitors, photopolymerization initiators and other additives can be included. When the active energy ray-curable pressure-sensitive adhesive composition is used, the formed pressure-sensitive adhesive layer can be irradiated with active energy rays to obtain a cured product having a desired degree of curing.

The pressure-sensitive adhesive layer can be formed by applying an organic solvent-diluted solution of the pressure-sensitive adhesive composition on a substrate and drying it.

When the bonding layer 36 is an adhesive layer, the adhesive composition used to form the adhesive layer is not particularly limited as long as it can satisfy the above-mentioned moisture permeability. Examples of the adhesive composition include water-based adhesives, active energy ray-curable adhesives, natural rubber adhesives, α-olefin adhesives, urethane resin adhesives, ethylene-vinyl acetate resin emulsion adhesives, and ethylene-. Vinyl acetate resin hot melt adhesive, epoxy resin adhesive, vinyl chloride resin solvent adhesive, chloroprene rubber adhesive, cyanoacrylate adhesive, silicone adhesive, styrene-butadiene rubber solvent adhesive, nitrile Rubber adhesives, nitrocellulose adhesives, reactive hot melt adhesives, phenol resin adhesives, modified silicone adhesives, polyester hot melt adhesives, polyamide resin hot melt adhesives, polyimide adhesives, polyurethane Resin Hotlt Adhesive, Polyolefin Resin Hot Melt Adhesive, Polyvinyl Acetate Resin Solvent Adhesive, Polystyrene Resin Solvent Adhesive, Polypoly Alcohol Adhesive, Polypolypyrrolidone Resin Adhesive, Polyvinyl Butyral Adhesive, Polybenzimidazole Examples thereof include adhesives, polymethacrylate resin solvent-based adhesives, melamine resin-based adhesives, urea resin-based adhesives, and resorcinol-based adhesives. Such an adhesive can be used alone or in combination of two or more.

Examples of the water-based adhesive include a polyvinyl alcohol-based resin aqueous solution, a water-based two-component urethane-based emulsion adhesive, and the like. The active energy ray-curable adhesive is an adhesive that cures by irradiating with active energy rays such as ultraviolet rays, and includes, for example, a polymerizable compound and a photopolymerizable initiator, a photoreactive resin, and the like. Examples thereof include those containing a binder resin and a photoreactive cross-linking agent. Examples of the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable (meth) acrylic monomer, and a photocurable urethane monomer, and oligomers derived from these monomers. .. Examples of the photopolymerization initiator include substances that generate active species such as neutral radicals, anionic radicals, and cationic radicals by irradiating them with active energy rays such as ultraviolet rays.

The thickness of the laminating layer is not particularly limited, but when the laminating layer is an adhesive layer, it is preferably 5 μm or more, 15 μm or more, 20 μm or more, 25 μm or more. It may be usually 200 μm or less, 100 μm or less, or 50 μm or less. When the bonding layer is an adhesive layer, the thickness of the bonding layer is preferably 0.01 μm or more, may be 0.05 μm or more, may be 0.5 μm or more, and may be 5 μm. It is preferably 3 μm or less, and may be 2 μm or less.

(Linear polarizing layer)
The linearly polarized light layer 33 has a function of selectively transmitting linearly polarized light in a certain direction from unpolarized light rays such as natural light. As described above, the linearly polarizing layer 33 contains a cured product of the polymerizable liquid crystal compound and a dichroic dye, and the dichroic dye is dispersed and oriented in the cured product of the polymerizable liquid crystal compound. Compared with the linearly polarized light layer in which a dichroic dye such as iodine is adsorbed and oriented on a polyvinyl alcohol-based resin, the linearly polarized light layer 33 has a small dimensional change because the shrinkage amount in the moist heat test is small. Therefore, it can be suitably used for a circularly polarizing plate used in an environment where wet and heat durability is required.

The polymerizable liquid crystal compound is a compound having a polymerizable reactive group and exhibiting liquid crystallinity. The polymerizable reactive group is a group involved in the polymerization reaction, and is preferably a photopolymerizable reactive group. The photopolymerizable reactive group refers to a group that can participate in the polymerization reaction by an active radical, an acid, or the like generated from the photopolymerization initiator. Examples of the photopolymerizable functional group include a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxylanyl group, an oxetanyl group and the like. Of these, an acryloyloxy group, a methacryloyloxy group, a vinyloxy group, an oxylanyl group and an oxetanyl group are preferable, and an acryloyloxy group is more preferable. The type of the polymerizable liquid crystal compound is not particularly limited, and a rod-shaped liquid crystal compound, a disk-shaped liquid crystal compound, and a mixture thereof can be used. The liquid crystal property of the polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal, and the phase-ordered structure may be a nematic liquid crystal or a smectic liquid crystal.

The dichroic dye refers to a dye having a property in which the absorbance in the major axis direction and the absorbance in the minor axis direction of the molecule are different.

As the dichromatistic dye, those having an absorption maximum wavelength (λMAX) in the range of 300 to 700 nm are preferable. Examples of such a dichroic dye include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye, and an anthraquinone dye, and among them, the azo dye is preferable. Examples of the azo dye include a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye, a stilbene azo dye, and the like, and a bisazo dye and a trisazo dye are preferable. The dichroic dye may be used alone or in combination of two or more, but it is preferable to combine three or more. In particular, it is more preferable to combine three or more kinds of azo compounds. A part of the dichroic dye may have a reactive group or may have a liquid crystallinity.

The linear polarizing layer 33 is cured by applying a polarizing layer forming composition containing a polymerizable liquid crystal compound and a dichroic dye onto, for example, an orientation layer formed on the base material layer 32, and polymerizing the polymerizable liquid crystal compound. It can be formed by letting it. Alternatively, the linear polarizing layer 33 may be formed by applying a polarizing layer forming composition on the base material layer 32 to form a coating film and stretching the coating film together with the base material layer 32. The base material layer 32 used for forming the linearly polarized light layer 33 may be included in the circular polarizing plate as shown in FIGS. 2 to 4.

Examples of a composition for forming a polarizing layer containing a polymerizable liquid crystal compound and a dichroic dye, and a method for producing a linear polarizing layer using this composition are JP-A-2013-373353 and JP-A-2013-33249. Examples thereof include those described in JP-A-2017-83843. The composition for forming a polarizing layer further contains additives such as a solvent, a polymerization initiator, a cross-linking agent, a leveling agent, an antioxidant, a plasticizer, and a sensitizer, in addition to the polymerizable liquid crystal compound and the dichroic dye. You may be. As for each of these components, only one kind may be used, or two or more kinds may be used in combination.

The polymerization initiator that may be contained in the polarizing layer forming composition is a compound that can initiate the polymerization reaction of the polymerizable liquid crystal compound, and is photopolymerizable in that the polymerization reaction can be initiated under lower temperature conditions. Initiators are preferred. Specific examples thereof include photopolymerization initiators capable of generating active radicals or acids by the action of light, and among them, photopolymerization initiators that generate radicals by the action of light are preferable. The content of the polymerization initiator is preferably 1 part by mass to 10 parts by mass, and more preferably 3 parts by mass to 8 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable liquid crystal compound. Within this range, the reaction of the polymerizable group proceeds sufficiently, and the orientation state of the liquid crystal compound is likely to be stabilized.

The thickness of the linearly polarizing layer is not particularly limited, but is preferably 20 μm or less, more preferably 10 μm or less, and further preferably 5 μm or less.

(Base material layer)
The base material layer 32 that the circularly polarizing plate may have can function as a protective layer for the linearly polarized light layer 33. The base material layer 32 may be coated with a polarizing layer forming composition when the linear polarizing layer 33 is formed.

The base material layer 32 is preferably a film made of a resin material. As the resin material, for example, a resin material having excellent transparency, mechanical strength, thermal stability, stretchability and the like is used. Specifically, polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene polymers; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (meth) acrylic acid, poly (meth) methyl acrylate and the like. (Meta) acrylic acid resin; cellulose ester resin such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; vinyl alcohol resin such as polyvinyl alcohol and polyvinyl acetate; polycarbonate resin; polystyrene resin; poly Arilate-based resin; polysulfone-based resin; polyethersulfone-based resin; polyamide-based resin; polyimide-based resin; polyetherketone-based resin; polyphenylene sulfide-based resin; polyphenylene oxide-based resin, and mixtures and copolymers thereof. Can be done. Among these resins, it is preferable to use any one of cyclic polyolefin-based resin, polyester-based resin, cellulose ester-based resin and (meth) acrylic acid-based resin, or a mixture thereof.

The base material layer 32 may be a single layer obtained by mixing one type or two or more types of resin materials, or may have a multilayer structure of two or more layers. When having a multi-layer structure, the resins forming each layer may be the same or different from each other. When the base material layer 32 is a film formed of a resin material, any additive may be added to the base material layer 32. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an antioxidant, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent.

The thickness of the base material layer 32 is not particularly limited, but is generally preferably 5 μm or more, preferably 10 μm or more, 15 μm or more, or 15 μm or more from the viewpoint of workability such as strength and handleability. , Usually 300 μm or less, 200 μm or less, or 100 μm or less.

(Λ / 4 phase difference layer)
The λ / 4 retardation layer 38 has a function of imparting a substantially λ / 4 phase difference to the incident light, and the incident light is usually light in the visible light region. As described above, the λ / 4 retardation layer 38 contains a cured product of the polymerizable liquid crystal compound. As the polymerizable liquid crystal compound, for example, those described above can be used. The polymerizable liquid crystal compound forming the polarizing layer and the polymerizable liquid crystal compound forming the λ / 4 retardation layer may be the same or different.

The λ / 4 retardation layer 38 is formed by, for example, applying a composition for forming a retardation layer containing a polymerizable liquid crystal compound on a substrate layer for a retardation layer, and polymerizing and curing the polymerizable liquid crystal compound. can do. The base material layer for the retardation layer used for forming the λ / 4 retardation layer 38 may be included in the circular polarizing plate. As the base material layer for the retardation layer, for example, the one described in the above-mentioned base material layer can be used.

The thickness of the λ / 4 retardation layer 38 is not particularly limited, but is preferably 0.1 μm or more, may be 0.5 μm or more, may be 1 μm or more, and is usually 50 μm or less, and is 30 μm. It may be 20 μm or less, and is preferably 10 μm or less from the viewpoint of thinning.

(Overcoat layer)
The overcoat layer 34 (FIGS. 3 to 5) that the circularly polarizing plate may have protects the linearly polarized light layer 33, suppresses the migration of the dichroic dye in the linearly polarized light layer 33, and is a barrier against oxygen and moisture. It can be provided for the purpose of imparting sex. The overcoat layer 34 may be provided on both sides of the linearly polarizing layer 33, or may be provided on one side. When the base material layer 32 is provided on the side opposite to the bonding layer 36 of the linearly polarized light layer 33, the overcoat layer 34 can be provided directly on the bonded layer 36 side of the linearly polarized light layer 33, for example, the linearly polarized light layer 33. It can be formed by applying a material (composition) for forming the overcoat layer 34 on the top.

The overcoat layer 34 preferably has excellent solvent resistance, transparency, mechanical strength, thermal stability, shielding property, isotropic property, and the like. The overcoat layer 34 provided on one surface of the linearly polarizing layer 33 may be one layer or two or more layers. When the overcoat layer 34 is two or more layers, the materials constituting each layer may be the same or different from each other. Further, when the overcoat layers 34 are provided on both surfaces of the linearly polarizing layer 33, each overcoat layer 34 may be formed of the same material or may be formed of different materials. Examples of the material constituting the overcoat layer 34 include a photocurable resin and a water-soluble polymer.

Examples of the photocurable resin include (meth) acrylic resin, urethane resin, (meth) acrylic urethane resin, epoxy resin, silicone resin and the like. Examples of the water-soluble polymer include poly (meth) acrylamide-based polymers; polyvinyl alcohol, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, (meth) acrylic acid or its anhydride-vinyl alcohol co-weight. Examples thereof include vinyl alcohol-based polymers such as coalescence; carboxyvinyl-based polymers; polyvinylpyrrolidone; starches; sodium alginate; polyethylene oxide-based polymers.

The thickness of the overcoat layer 34 is not particularly limited, but is preferably 20 μm or less, more preferably 15 μm or less, further preferably 10 μm or less, 5 μm or less, and 0. It is 0.05 μm or more, and may be 0.5 μm or more.

(Hard coat layer)
The hard coat layer 31 (FIG. 4) that the circularly polarizing plate may have is provided for the purpose of improving the hardness and scratch resistance of the base material layer 32. The hard coat layer 31 may be provided on both sides of the base material layer 32, but is preferably provided on the side of the base material layer 32 opposite to the linearly polarized light layer 33 side. The hard coat layer 31 can be formed, for example, by applying a material (composition) for forming the hard coat layer 31 on the base material layer 32.

The hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of the ultraviolet curable resin include (meth) acrylic resins such as monofunctional (meth) acrylic resins, polyfunctional (meth) acrylic resins, and polyfunctional (meth) acrylic resins having a dendrimer structure; silicone-based resins. Resins; polyester resins; urethane resins; amide resins; epoxy resins and the like can be mentioned. The hard coat layer may contain additives to improve strength. Additives are not limited, and examples thereof include inorganic fine particles, organic fine particles, and mixtures thereof.

(Orientation layer)
The alignment layer has an orientation-regulating force that orients the polymerizable liquid crystal compound in a desired direction. As described above, the circular polarizing plate may have an orientation layer on the side opposite to the bonding layer 36 side of the linearly polarizing layer 33, and is different from the bonding layer 36 side of the λ / 4 retardation layer 38. An orientation layer may be provided on the opposite side or on the bonding layer 36 side of the λ / 4 retardation layer 38. In the circular polarizing plate having the alignment layer for the linear polarizing layer 33 and the alignment layer for the λ / 4 retardation layer, the layer structure thereof is, for example, the following [a] to [d]:
[A] Alignment layer, linear polarizing layer, bonded layer, λ / 4 retardation layer, alignment layer [b] Linear polarizing layer, alignment layer, bonding layer, λ / 4 retardation layer, alignment layer [c] Orientation Layer, linear polarizing layer, bonding layer, alignment layer, λ / 4 retardation layer [d] It can be any of linear polarization layer, alignment layer, bonding layer, alignment layer, and λ / 4 retardation layer.

Examples of the oriented layer include an oriented polymer layer formed of an oriented polymer, a photo-oriented polymer layer formed of a photo-aligned polymer, and a grub-oriented layer having an uneven pattern or a plurality of grubs (grooves) on the layer surface. Can be done. The thickness of the alignment layer is usually 10 to 500 nm, preferably 10 to 200 nm.

The oriented polymer layer can be formed by applying a composition in which an oriented polymer is dissolved in a solvent to a base material layer or a base material layer for a phase layer to remove the solvent, and if necessary, rubbing treatment. it can. In this case, the orientation regulating force can be arbitrarily adjusted in the orientation polymer layer formed of the orientation polymer depending on the surface condition of the orientation polymer and the rubbing conditions.

The photo-oriented polymer layer can be formed by applying a composition containing a polymer or monomer having a photoreactive group and a solvent to a base material layer or a base material layer for a phase layer and irradiating with polarized light. In this case, the orientation-regulating force can be arbitrarily adjusted in the photo-orientation polymer layer depending on the polarization irradiation conditions for the photo-orientation polymer.

The grub alignment layer is active on a plate-shaped master having grooves on the surface, for example, a method of forming a concavo-convex pattern by exposing and developing through an exposure mask having a pattern-shaped slit on the surface of a photosensitive polyimide film. A method of forming an uncured layer of an energy ray-curable resin, transferring this layer to a base material layer or a base material layer for a phase layer and curing it, and an active energy ray curing method on a base material layer or a base material layer for a phase layer. It can be formed by forming an uncured layer of the sex resin, forming irregularities by pressing a roll-shaped master having irregularities against this layer, and curing the layers.

(Lated layer for glass plate)
The bonding layer 42 for a glass plate is a layer for bonding a circularly polarizing plate and a glass plate 41. The bonding layer 42 for a glass plate is a pressure-sensitive adhesive layer formed by using the pressure-sensitive adhesive composition or an adhesive layer formed by using the pressure-sensitive adhesive composition. As the material contained in the pressure-sensitive adhesive composition or the adhesive composition, known materials can be used, and examples thereof include those exemplified in the pressure-sensitive adhesive composition and the adhesive composition used for the bonding layer. Can be done.

The thickness of the laminated layer for the glass plate is also not particularly limited, but can be, for example, 10 μm or more and 200 μm or less.

(Glass plate)
As the glass plate 41, a known one can be used. The glass plate 41 may be used, for example, for a front plate, a touch panel, or an image display element arranged on the foremost surface of a display device.

The thickness of the glass plate 41 is not particularly limited, but can be, for example, 30 μm or more and 2 mm or less.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples. Unless otherwise specified, the blending amounts represented by "%" and "parts" in Examples and Comparative Examples are mass% and parts by mass.

The evaluation method is as follows.
[Measurement of moisture permeability]
The moisture permeability of the pressure-sensitive adhesive layer used in the examples was measured by the following procedure. A triacetyl cellulose (TAC) film (KC2UA, manufactured by Konica Minolta Co., Ltd., thickness 25 μm) was attached to the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive sheet prepared in the section of preparation of the pressure-sensitive adhesive sheet below. Then, the release film was peeled off to obtain a measurement sample. Using the obtained measurement sample, the moisture permeability (water vapor permeability) was measured at a measurement temperature of 40 ° C., a measurement humidity of 90% RH, and a measurement time of 24 hours by a moisture permeability test method according to JIS Z 0208 (cup method). Was measured. The measurement was carried out using a constant temperature and humidity chamber. The results are shown in Table 1. Since the moisture permeability of the TAC film is sufficiently larger than the moisture permeability of the pressure-sensitive adhesive layer, the moisture permeability measured using the measurement sample can be regarded as the moisture permeability of the pressure-sensitive adhesive layer.

As for the pressure-sensitive adhesive layer used in the comparative example, the pressure-sensitive adhesive layer was bonded to the above-mentioned TAC film, and the moisture permeability was measured by the same procedure as described above. The results are shown in Table 1.

[Moist heat test]
The reflectance and retardation (R0) were measured using the circularly polarizing plate with a glass plate provided with glass plates on both sides of the circularly polarizing plate obtained in Examples and Comparative Examples, and the appearance was evaluated. Next, a circularly polarizing plate with a glass plate was stored in a moist heat environment at a temperature of 85 ° C. and a humidity of 85% RH for 150 hours, and then the reflectance and retardation were measured to evaluate the appearance. The change in reflectance before and after the moist heat test (Δreflectance [%]) and the change in retardation before and after the moist heat test (ΔR0) were calculated, and the change in appearance before and after the moist heat test was evaluated. In addition, the reflected hue observed from an oblique direction was evaluated for the circularly polarizing plate with a glass plate after the moist heat test. The reflectance, retardation, and reflection hue observed from an oblique direction were measured by the following procedure. The changes in appearance and the reflected hue observed from an oblique direction were evaluated as follows.

(1) Measurement of reflectance Glass obtained in Examples and Comparative Examples on a reflecting plate (aluminum plate, reflectance 97%) so that the linearly polarized light layer side is the visible side with respect to the λ / 4 retardation layer. A circularly polarizing plate with a plate was placed, and the reflectance [%] was measured under the conditions of SCI mode and D65 standard light using a spectrocolorimeter (CM-2600d, manufactured by Konica Minolta). The change in reflectance (Δreflectance [%]) before and after the moist heat test is calculated by the following formula:
ΔReflectance [%] = (Reflectance after moist heat test [%])-(Reflectance before moist heat test [%])
It was calculated based on.

(2) Measurement of retardation (R0) With respect to the circularly polarizing plate with a glass plate obtained in Examples and Comparative Examples, a phase difference meter based on the parallel Nicol rotation method (KOBRA (registered trademark) -WPR, Oji Measuring Instruments Co., Ltd. ) Was used to measure the in-plane retardation at a wavelength of 550 nm at a temperature of 23 ° C. The change in retardation (ΔR0 [nm]) before and after the moist heat test is calculated by the following formula:
ΔR0 [nm] = (Ratedation after wet heat test [nm])-(Ratedation before wet heat test [nm])
It was calculated based on.

(3) Appearance evaluation Glass plates obtained in Examples and Comparative Examples on a reflective plate (aluminum plate, reflectance 97%) so that the linearly polarized light layer side is the visible side with respect to the λ / 4 retardation layer. A circularly polarizing plate with a polarizing plate was placed, and the presence or absence of reddening when visually recognized from the linearly polarizing layer side was evaluated. The case where the red change was not visually recognized was evaluated as A, and the case where the red change was visually recognized was evaluated as B.

(4) Evaluation of Reflected Hua Observed from Oblique Direction Examples and comparisons so that the linearly polarized light layer side is the visible side with respect to the λ / 4 retardation layer on the reflective plate (aluminum plate, reflectance 97%). The circularly polarizing plate with a glass plate obtained in the example was placed. For this circularly polarizing plate with a glass plate, the color coordinates La ^* b ^* were measured from the direction in which the inclination angle at all azimuth angles was 50 ° using a display measurement system (DMS-803, Instrument Systems). From the color coordinates where a ^* is the maximum and the color coordinates where a ^* is the minimum, ΔE was calculated based on the following equation. In the equation, the color coordinates where a ^* is the maximum are (a ^{* 1} , b ^{* 1} ), and the color coordinates where a ^* is the minimum are (a ^{* 2} , b ^{* 2} ).
ΔE = (│a ^{* 1} −a ^{* 2} │ ² + │b ^{* 1} −b ^{* 2} │ ² ) ^0.5
The case where ΔE was 10 or less was evaluated as A, the case where ΔE was more than 10 and 21 or less was evaluated as B, and the case where ΔE was more than 21 was evaluated as C.

The materials used for the circularly polarizing plate with a glass plate obtained in each Example and Comparative Example were prepared by the following procedure.

[Preparation of adhesive sheet]
Adhesive sheets (x) and (y) having an adhesive layer as a laminating layer were prepared.
(1) Adhesive sheet (x)
100 parts of polyisobutylene (PIB) (OPPANOL B80, manufactured by BASF, Mw: about 750,000) as a rubber-based polymer, tricyclodecanedimethanol diacrylate (NK ester A-DCP, manufactured by Shin-Nakamura Chemical Industry Co., Ltd.), Bifunctional acrylate, molecular weight 304) 10 parts, benzophenone as a polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd.) 0.5 parts, completely hydrogenated terpenephenol as a pressure-sensitive adhesive (manufactured by Yasuhara Chemical Co., Ltd.) 5 parts Was mixed. Toluene was added to this mixture so that the total solid content concentration was 15% to obtain a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition obtained above is applied to the release-treated surface of the release film (release-treated polyethylene terephthalate film, thickness 38 μm) so that the thickness after drying is 25 μm using an applicator. The film was dried at a temperature of 80 ° C. for 3 minutes and irradiated with UV-A so that the amount of light was 1000 mJ to obtain a pressure-sensitive adhesive sheet (x) provided with a pressure-sensitive adhesive layer (X).

(2) Adhesive sheet (y)
Instead of tricyclodecanedimethanol diacrylate, trimethylolpropane triacrylate (NK ester A-TMPT, trifunctional acrylate manufactured by Shin Nakamura Chemical Industry Co., Ltd., molecular weight 296) is used, and the amount of completely hydrogenated terpene phenol is blended. A pressure-sensitive adhesive composition was obtained in the same manner as in the preparation of the pressure-sensitive adhesive sheet (x), except that 10 parts were used. An adhesive sheet (y) having an adhesive layer (Y) was obtained in the same manner as the adhesive sheet (x) except that the adhesive composition obtained here was used.

[Preparation of composition for forming alignment layer]
A solution prepared by dissolving a polymer having a photoreactive group represented by the following structural formula in cyclopentanone at a concentration of 5% was prepared as the alignment layer forming composition (1).

・化合物（１−２）

[Preparation of composition for forming a polarizing layer]
Compound (1-1) and compound (1-2) represented by the following structures were used as the polymerizable liquid crystal compound. Compound (1-1) and compound (1-2) are described in Lub et al. Recl. Trav. Chim. It was synthesized by the method described in Pays-Bas, 115, 321-328 (1996).
-Compound (1-1)

-Compound (1-2)

・化合物（２−１ｂ）

・化合物（２−３ａ）

Compound (2-1a), compound (2-1b), and compound (2-3a) represented by the following structures were used as dichroic dyes.
-Compound (2-1a)

-Compound (2-1b)

-Compound (2-3a)

The composition for forming a polarizer contains 75 parts of compound (1-1), 25 parts of compound (1-2), and the above formulas (2-1a), (2-1b), and (2-3a) as a bicolor dye. ), 2.5 parts each of the azo dye, 6 parts of 2-dimethylamino-2-benzyl-1- (4-morpholinophenyl) butane-1-one (Irgacure 369, manufactured by BASF) as a polymerization initiator, and 1.2 parts of a polyacrylate compound (BYK-361N, manufactured by BYK) as a leveling agent was mixed with 400 parts of toluene as a solvent, and the obtained mixture was prepared by stirring at 80 ° C. for 1 hour.

[Preparation of λ / 4 retardation layer]
(Preparation of composition for forming a retardation layer)
The composition for forming a retardation layer for forming a λ / 4 retardation layer was prepared by mixing each of the following components and stirring the obtained mixture at 80 ° C. for 1 hour.

・下記の構造式で表される化合物：２０部

・重合開始剤（Ｉｒｇａｃｕｒｅ３６９、ＢＡＳＦ社製）：６部
・レベリング剤（ＢＹＫ−３６１Ｎ、ポリアクリレート化合物、ＢＹＫ社製）：０．１部・溶剤（シクロペンタノン）：４００部 -Compound represented by the following structural formula: 80 parts

-Compound represented by the following structural formula: 20 parts

-Polymerization initiator (Irgacure 369, manufactured by BASF): 6 parts-Leveling agent (BYK-361N, polyacrylate compound, manufactured by BYK): 0.1 parts-Solvent (cyclopentanone): 400 parts

(Preparation of λ / 4 retardation layer)
The composition for forming an orientation layer (1) prepared above is applied onto a polyethylene terephthalate (PET) film (thickness 100 μm) as a base material by a bar coating method, and dried by heating in a drying oven at a temperature of 80 ° C. for 1 minute. did. The obtained coating film was subjected to polarized UV irradiation treatment to form an orientation layer. The polarized UV treatment was carried out using a UV irradiation device (SPOT CURE SP-7, manufactured by Ushio, Inc.) under the condition that the integrated light amount measured at a wavelength of 365 nm was 100 mJ / cm ² . Further, the polarization direction of the polarized UV was set to 45 ° with respect to the absorption axis of the polarizer.

The composition for forming a retardation layer prepared above was applied onto the alignment layer formed above by a bar coating method, heated and dried in a drying oven at a temperature of 120 ° C. for 1 minute, and then cooled to room temperature. The obtained coating film is irradiated with ultraviolet rays using the above UV irradiation device so that the integrated light amount is 1000 mJ / cm ² (365 nm standard) to form a λ / 4 retardation layer having a thickness of 2.0 μm. , A λ / 4 retardation layer with a PET film was obtained. The λ / 4 retardation layer showed anti-wavelength dispersibility.

[Preparation for positive C layer]
(Preparation of composition for forming alignment layer)
2-Butoxyethanol was added to Sunever SE-610 (manufactured by Nissan Chemical Industries, Ltd.) to prepare a composition (2) for forming an orientation layer.

(Preparation of composition for forming a retardation layer)
The composition for forming a retardation layer for forming a positive C layer was prepared by mixing each of the following components, stirring the obtained mixture at 80 ° C. for 1 hour, and cooling to room temperature.
-LC242 (BASF, polymerizable liquid crystal compound): 20.3 parts-Polymerization initiator (Irgacure907, manufactured by BASF): 0.5 parts-Leveling agent (BYK-361N, polyacrylate compound, manufactured by BYK): 0 . 1 part ・ Solvent (propylene glycol 1-monomethyl ether 2-acetate): 400 parts

(Preparation of positive C layer)
A cycloolefin polymer film (ZF-14 manufactured by Zeon Corporation, thickness 23 μm) that had not been stretched was prepared as a base material. The surface of this film was corona-treated once using a corona processing apparatus under the conditions of an output of 0.3 kW and a processing speed of 3 m / min. The composition for forming an orientation layer (2) was applied to the surface treated with corona using a bar coater. The coating film was dried at 90 ° C. for 1 minute to form a vertically oriented layer. The film thickness of the obtained vertically oriented layer was 34 nm.

A composition for forming a retardation layer was applied onto the vertically oriented layer using a bar coater. The coating film was dried at 90 ° C. for 1 minute. A high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio, Inc.) was irradiated with ultraviolet rays to polymerize a polymerizable liquid crystal compound. The ultraviolet rays were irradiated in a nitrogen atmosphere so that the integrated light amount at a wavelength of 365 nm was 1000 mJ / cm ² . The film thickness of the obtained retardation layer was 450 nm. Moreover, when the retardation value of the obtained retardation layer was measured at a wavelength of 550 nm, it was Re (550) = 1 nm and Rth (550) = −70 nm. That is, the relationship of the three-dimensional refractive index of the obtained retardation layer was nx≈ny <nz, and it had optical characteristics as a positive C layer.

[Preparation of λ / 2 retardation layer]
(Preparation of composition for forming a retardation layer)
The composition for forming a retardation layer for forming a λ / 2 retardation layer was prepared by mixing each of the following components, stirring the obtained mixture at 80 ° C. for 1 hour, and cooling to room temperature. ..
-LC242 (BASF, polymerizable liquid crystal compound): 20.3 parts-Polymerization initiator (Irgacure907, manufactured by BASF): 0.5 parts-Leveling agent (BYK-361N, polyacrylate compound, manufactured by BYK): 0 . 1 part ・ Solvent (propylene glycol 1-monomethyl ether 2-acetate): 400 parts

(Preparation of λ / 2 retardation layer)
A cycloolefin polymer film (ZF-14 manufactured by Zeon Corporation, thickness 23 μm) that had not been stretched was prepared as a base material. The surface of this film was corona-treated once under the conditions of an output of 0.3 kW and a processing speed of 3 m / min using a corona processing apparatus (AGF-B10, manufactured by Kasuga Electric Works Ltd.). The composition for forming an orientation layer (2) was applied to the surface treated with corona using a bar coater. The coating film is dried at 80 ° C. for 1 minute, and the coating film is irradiated with polarized UV so that the integrated light intensity is 100 mJ / cm ² using a polarized UV irradiation device (SPOT CURE SP-7; manufactured by Ushio, Inc.). did. The film thickness of the obtained alignment layer was 100 nm.

The composition for forming a retardation layer was applied onto the alignment layer using a bar coater. At this time, the thickness of the coating film was adjusted by changing the thickness of the wire bar, and the phase difference value was controlled. The coating film was dried at 120 ° C. for 1 minute, and then irradiated with ultraviolet rays using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio, Inc.) to polymerize the polymerizable liquid crystal compound. The ultraviolet rays were irradiated in a nitrogen atmosphere so that the integrated light amount at a wavelength of 365 nm was 1000 mJ / cm ² . The film thickness of the obtained retardation layer was 2 μm, and when the retardation value was measured at a wavelength of 550 nm, it was Re (550) = 270 nm and Rth (550) = 138 nm. The obtained retardation layer was a λ / 2 retardation layer.

[Preparation of composition for forming overcoat layer]
The composition for forming the overcoat layer for forming the overcoat layer is 100 parts of water, 3 parts of polyvinyl alcohol resin powder (KL-318, manufactured by Kuraray Co., Ltd., average degree of polymerization 18000), and polyamide epoxy as a cross-linking agent. Prepared by mixing 1.5 parts of a resin (SR650 (30), manufactured by Sumika Chemtex Co., Ltd.).

[Preparation of adhesive layer 2]
While stirring 70 parts of butyl acrylate, 20 parts of methyl acrylate, 2.0 parts of acrylic acid, and 0.2 part of radical polymerization initiator (2,2'-azobisisobutyronitrile) in a nitrogen atmosphere. Acrylic resin was obtained by reacting at 55 ° C. 100 parts of the obtained acrylic resin, 1.0 part of a cross-linking agent (“Coronate L” manufactured by Tosoh Corporation), and 0.5 part of a silane coupling agent (“X-12-981” manufactured by Shin-Etsu Chemical Co., Ltd.) are mixed. did. Ethyl acetate was added so that the total solid content concentration was 10% to obtain a pressure-sensitive adhesive composition.

The obtained pressure-sensitive adhesive composition was applied to the release-treated surface of the release-treated polyethylene terephthalate film (thickness 38 μm) using an applicator so that the thickness after drying was 5 μm. The coating layer was dried at 100 ° C. for 1 minute to obtain an adhesive layer 2. Another release-treated polyethylene terephthalate film (thickness 38 μm) was laminated on the pressure-sensitive adhesive layer 2. It was cured for 7 days under the conditions of a temperature of 23 ° C. and a relative humidity of 50% RH.

[Example 1]
A triacetyl cellol (TAC) film (KC2UA, manufactured by Konica Minolta Co., Ltd., thickness 25 μm) as a base material layer was subjected to corona treatment. The conditions for corona treatment were an output of 0.3 kW and a processing speed of 3 m / min. Then, the composition for forming an orientation layer prepared above was applied to the corona-treated surface of the TAC film by a bar coating method, and dried by heating in a drying oven at a temperature of 80 ° C. for 1 minute. The light emitted from the UV irradiation device was passed through a wire grid (UIS-27132 ##, manufactured by Ushio, Inc.) through the obtained film, and the integrated light amount measured at a wavelength of 365 nm was 100 mJ / cm ² . It was done under such conditions. The thickness of the alignment layer was 100 nm.

The composition for forming a polarizing layer prepared above was applied onto the formed alignment layer by a bar coating method, heated and dried in a drying oven at a temperature of 120 ° C. for 1 minute, and then cooled to room temperature. The obtained film was irradiated with ultraviolet rays so that the integrated light intensity was 1200 mJ / cm ² (365 nm standard) using the above UV irradiation device to form a linearly polarizing layer having a thickness of 1.8 μm.

The composition for forming an overcoat layer prepared above was applied onto the formed linearly polarized light layer by a bar coating method so that the thickness after drying was 1.0 μm, and dried at a temperature of 80 ° C. for 3 minutes. In this way, a polarizing plate having a TAC film, an alignment layer, a linearly polarizing layer, and an overcoat layer in this order was obtained.

The pressure-sensitive adhesive layer (X) of the pressure-sensitive adhesive sheet (x) prepared above was attached to the overcoat layer side of the obtained polarizing plate, and the release film was peeled off. The λ / 4 retardation layer side of the λ / 4 retardation layer with the PET film prepared above is bonded onto the adhesive layer (X) exposed by peeling the release film, and the PET film is peeled off. A circularly polarizing plate was obtained. The circular polarizing plate had a TAC film, an alignment layer, a linear polarizing layer, an overcoat layer, an adhesive layer (X), and a λ / 4 retardation layer in this order.

Adhesive layers 1 (P-3132, manufactured by Lintec Corporation, thickness 25 μm) are provided on both sides of the circularly polarizing plate obtained above, and glass plates (Eagle XG, manufactured by Corning Inc.) are placed on the pressure-sensitive adhesive layer 1, respectively. By bonding, a circularly polarizing plate with a glass plate was obtained. When the circularly polarizing plate and the pressure-sensitive adhesive layer 1 were bonded together, the surface thereof was subjected to corona treatment. A wet heat test was performed on the obtained circularly polarizing plate with a glass plate. The results are shown in Table 1.

[Example 2]
Instead of the triacetyl cellol (TAC) film as the base material layer, a TAC film with a hard coat layer (25 KCHC, manufactured by Konica Minolta Co., Ltd., thickness 32 μm), which is a laminate of the hard coat layer and the base material layer, is used. A circular polarizing plate and a circular polarizing plate with a glass plate were obtained in the same manner as in Example 1 except that an alignment layer and a linearly polarizing layer were formed on the TAC film side of the TAC film with a hard coat layer. A wet heat test was performed on the obtained circularly polarizing plate with a glass plate. The results are shown in Table 1.

[Example 3]
A circularly polarizing plate and a glass plate in the same manner as in Example 1 except that the pressure-sensitive adhesive sheet (y) having the pressure-sensitive adhesive layer (Y) was used instead of the pressure-sensitive adhesive sheet (x) having the pressure-sensitive adhesive layer (X). A circularly polarizing plate was obtained. A wet heat test was performed on the obtained circularly polarizing plate with a glass plate. The results are shown in Table 1.

[Example 4]
Instead of the triacetyl cellol (TAC) film as the base material layer, a TAC film with a hard coat layer (25 KCHC, manufactured by Konica Minolta Co., Ltd., thickness 32 μm), which is a laminate of the hard coat layer and the base material layer, is used. A circular polarizing plate and a circular polarizing plate with a glass plate were obtained in the same manner as in Example 3 except that an alignment layer and a linearly polarizing layer were formed on the TAC film side of the TAC film with a hard coat layer. A wet heat test was performed on the obtained circularly polarizing plate with a glass plate. The results are shown in Table 1.

[Comparative Example 1]
A circular polarizing plate and a circular polarizing plate with a glass plate were used in the same manner as in Example 1 except that an acrylic pressure-sensitive adhesive layer (Z) (manufactured by Lintec Corporation) was used instead of the pressure-sensitive adhesive layer (X). Obtained. A wet heat test was performed on the obtained circularly polarizing plate with a glass plate. The results are shown in Table 1.

[Example 5]
The circularly polarizing plate obtained in Example 3 was prepared. The surface of the circularly polarizing plate on the λ / 4 retardation layer side was subjected to corona treatment, and the pressure-sensitive adhesive layer 2 (acrylic pressure-sensitive adhesive layer, thickness 5 μm) prepared above was laminated. The positive C layer was laminated on the pressure-sensitive adhesive layer 2 and the base material was peeled off to transfer the positive C layer. In this way, a circularly polarizing plate having a TAC film, an alignment layer, a linearly polarized light layer, an overcoat layer, an adhesive layer (Y), and a λ / 4 retardation layer, an adhesive layer 2, and a positive C layer in this order. Made.

A circularly polarizing plate with a glass plate was obtained in the same manner as in Example 1. A wet heat test was performed on the obtained circularly polarizing plate with a glass plate. The results are shown in Table 1.

[Example 6]
In the same manner as in Example 1, a polarizing plate having a TAC film, an alignment layer, a linearly polarized light layer, and an overcoat layer in this order was obtained. The pressure-sensitive adhesive layer 2 prepared above was attached to the overcoat layer side of the obtained polarizing plate, and the release film was peeled off. The λ / 2 retardation layer prepared above was laminated on the pressure-sensitive adhesive layer 2 exposed by peeling the release film, and the base material was peeled off. The angle formed by the absorption axis of the polarizer and the slow axis of the λ / 2 retardation layer was 15 °. The λ / 4 retardation layer was bonded to the exposed λ / 2 retardation layer by peeling the base material via the pressure-sensitive adhesive layer (Y) of the pressure-sensitive adhesive sheet (y), and the PET film was peeled off. The angle formed by the absorption axis of the polarizer and the slow axis of the λ / 4 retardation layer was 75 °. In this way, a circle having a TAC film, an alignment layer, a linearly polarized light layer, an overcoat layer, an adhesive layer 2, a λ / 2 retardation layer, an adhesive layer (Y), and a λ / 4 retardation layer in this order. A polarizing plate was obtained.

A circularly polarizing plate with a glass plate was obtained in the same manner as in Example 1. A wet heat test was performed on the obtained circularly polarizing plate with a glass plate. The results are shown in Table 1.

The circularly polarizing plate obtained in the examples had better optical characteristics even after the moist heat test as compared with the circularly polarizing plate obtained in the comparative example. In particular, in the circularly polarizing plate obtained in the examples, the phase difference value of the circularly polarizing plate does not easily change even after the moist heat test, and the reflectance does not easily change when the circularly polarizing plate is placed on the reflector, resulting in reddening. Has a good appearance that is hard to see.

11-14 circularly polarizing plate, 21 circularly polarizing plate with glass plate, 31 hard coat layer, 32 base material layer, 33 linearly polarized light layer, 34 overcoat layer, 36 bonded layer, 38 λ / 4 retardation layer, 41 glass Plate, 42 Laminated layer for glass plate.

Claims (9)

A circular polarizing plate having a linearly polarized light layer, a bonded layer, and a λ / 4 retardation layer in this order.
The linearly polarizing layer contains a cured product of a polymerizable liquid crystal compound and a dichroic dye.
The λ / 4 retardation layer contains a cured product of a polymerizable liquid crystal compound, and contains a cured product.
The temperature 40 ° C. lamination layer, the moisture permeability and humidity 90% RH is 100g ^/ (m 2 · 24hr) or less, the circularly polarizing plate. The circular polarizing plate according to claim 1, wherein the λ / 4 retardation layer has anti-wavelength dispersibility. The circularly polarizing plate according to claim 1 or 2, wherein the bonding layer is formed from a pressure-sensitive adhesive composition. The circularly polarizing plate according to claim 3, wherein the pressure-sensitive adhesive composition contains a rubber-based polymer. The circular polarizing plate according to any one of claims 1 to 4, further comprising an overcoat layer on one side or both sides of the linearly polarizing layer. The circular polarizing plate according to any one of claims 1 to 5, further comprising a base material layer on the side of the linearly polarizing layer opposite to the bonded layer side. The circular polarizing plate according to claim 6, further comprising a hard coat layer on the side of the base material layer opposite to the linearly polarized light layer side. The circular polarizing plate according to any one of claims 1 to 7, which is for in-vehicle use. A circularly polarizing plate with a glass plate having glass plates on both sides of the circularly polarizing plate according to any one of claims 1 to 8.

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