WO2018123457A1

WO2018123457A1 - Optical laminate

Info

Publication number: WO2018123457A1
Application number: PCT/JP2017/043548
Authority: WO
Inventors: 正寛市原
Original assignee: 住友化学株式会社
Priority date: 2016-12-28
Filing date: 2017-12-05
Publication date: 2018-07-05
Also published as: TW201830106A; JP2018106125A

Abstract

[Problem] To provide an optical laminate that includes two reflective polarizer layers and suitably functions as a half-mirror capable of suppressing the occurrence of iridescent unevenness and providing high visibility even when being arranged on the visible side of a display device. [Solution] This optical laminate includes: a first reflective polarizer layer; a second reflective polarizer layer; and an interposition layer that is arranged between the first reflective polarizer layer and the second reflective polarizer layer, wherein the angle formed between the reflection axis of the first reflective polarizer layer and the reflection axis of the second reflective polarizer layer is 20°-70°, and the haze is 0.4%-20%.

Description

Optical laminate

The present invention relates to an optical laminate.

Generally, the image display device displays an image on the screen with the power turned on, and the screen becomes black or gray when the power is turned off. In recent years, there has been proposed a mirror display that uses a screen in a state where the power is turned off (black display) as a mirror. The mirror display is arranged on the viewing side of the image display element so that the screen with the power turned off can be used as a mirror and an image can be displayed on the screen when the power is turned on. A half mirror is provided.

It is known to use a reflective polarizer as a half mirror. However, when only one reflective polarizer is used, the reflection luminance rate in black display is limited to about 50%, and it is difficult to obtain a clear image as a mirror. Thus, it has been proposed to form a half mirror using a plurality of reflective polarizers (Patent Documents 1 and 2).

International Publication No. 2015/0198858 JP 2001-133769 A

In Patent Document 1, a half mirror plate is constituted by two reflective polarizing plates arranged so that their transmission axes intersect with each other, thereby preventing a reduction in screen luminance in the display mode and in the mirror mode. It is described that the reflectance of the light can be increased (paragraphs [0010] and [0011]). However, if the half mirror plate is configured by crossing the transmission axes of the two reflective polarizing plates and arranged on the viewing side of the image display device, the light reflected by each of the reflective polarizing plates interferes with the rainbow unevenness. It has been found that visibility decreases in both the mirror mode and the display mode.

Patent Document 2 describes using a member in which two reflective polarizing plates (reflective polarization separators) are stacked on the backlight side of a transflective liquid crystal display device. The same document describes that the two reflection-type polarizing plates are bonded in order to prevent the occurrence of interference fringes (synonymous with rainbow unevenness) (paragraph [0056]). However, the influence of rainbow unevenness due to light interference differs greatly between the backlight side and the viewing side. When an optical layered body in which two reflective polarizing plates are laminated on the backlight side is installed, the optical layered body is visually recognized through the display device, and rainbow unevenness tends to be difficult to be visually recognized. On the other hand, when an optical layered body in which two reflective polarizing plates are bonded together is arranged on the viewing side, the rainbow unevenness of the optical layered body is directly observed, so visibility in both the mirror mode and the display mode is achieved. Is significantly reduced.

An object of the present invention is an optical laminate including two reflective polarizer layers, which can suppress the occurrence of rainbow unevenness even when it is arranged on the viewing side of a display device, and has good visibility. An object of the present invention is to provide an optical laminate suitable as a half mirror that can be provided.

The present invention provides the following optical laminate.
[1] including a first reflective polarizer layer, a second reflective polarizer layer, and an intervening layer disposed between the first reflective polarizer layer and the second reflective polarizer layer,
The angle formed by the reflection axis of the first reflective polarizer layer and the reflection axis of the second reflective polarizer layer is 20 ° or more and 70 ° or less,
An optical laminate having a haze of 0.4% to 20%.

[2] The optical layered body according to [1], wherein the reflection luminance rate is 55% or more and 85% or less.
[3] The optical laminate according to [1] or [2], wherein the intervening layer has a haze of 0.8% to 20%.

[4] The optical laminate according to any one of [1] to [3], wherein the intervening layer includes two or more layers.

[5] The optical laminate according to [4], wherein the two or more layers have different hazes.

[6] The optical stack according to any one of [1] to [5], further including a base material layer disposed outside the first reflective polarizer layer or outside the second reflective polarizer layer. body.

[7] The optical laminate according to [6], wherein the base material layer includes an absorption polarizer layer.
[8] The optical system according to any one of [1] to [7], further including an adhesive layer laminated on at least one outer surface of the first reflective polarizer layer and the second reflective polarizer layer. Laminated body.

[9] The optical laminate according to any one of [1] to [8], which is disposed on the viewing side of the display element.

An optical laminate including two reflective polarizer layers, which can suppress the occurrence of rainbow unevenness even when arranged on the viewing side of a display device, and can provide good visibility As such, a suitable optical laminate can be provided.

It is a schematic sectional drawing which shows an example of the optical laminated body which concerns on this invention. It is a schematic sectional drawing which shows another example of the optical laminated body which concerns on this invention. It is a schematic sectional drawing which shows another example of the optical laminated body which concerns on this invention. It is a schematic sectional drawing which shows another example of the optical laminated body which concerns on this invention. It is sectional drawing which shows typically the optical system for measuring luminous reflectance _RSCI .

Hereinafter, the present invention will be described in detail with reference to embodiments.
In this specification, “A to B” (A and B are numerical values) represents “A or more and B or less” unless otherwise specified.

<Optical laminate>
FIG. 1 is a schematic cross-sectional view showing an example of an optical laminate according to the present invention. An optical laminate 100 shown in FIG. 1 is an optical member that can be suitably used as a half mirror element having two reflective polarizer layers, and includes a first reflective polarizer layer 10 and a second reflective polarizer. Layer 20; includes an intervening layer 30 disposed between the first reflective polarizer layer 10 and the second reflective polarizer layer 20. The first reflective polarizer layer 10 is laminated on one surface of the intervening layer 30 via the first pressure-sensitive adhesive layer 40. The second reflective polarizer layer 20 is laminated on the other surface of the intervening layer 30 via the second pressure-sensitive adhesive layer 50.

The angle formed by the reflection axis of the first reflective polarizer layer 10 and the reflection axis of the second reflective polarizer layer 20 (hereinafter also referred to as “relative angle of the reflection axis”) is 20 to 70 °, and is optical. The haze of the laminate 100 is 0.4 to 20%. The haze of the optical laminate 100 is preferably 0.4 to 10%, more preferably 0.4 to 8%, still more preferably 0.5 to 6%, and 0.5 to It may be 5%.

According to the optical layered body 100 having the above-described configuration, the occurrence of rainbow unevenness can be effectively suppressed even when the optical laminated body 100 is disposed on the viewing side of the display device, and good visibility can be provided. The visibility here refers to the visibility of the image when the display device is turned on and the screen is displayed in white (display mode), and the display device is used as a device for displaying an image on the screen. Is turned off, the screen is displayed in black (mirror mode), and the visibility when using the display device as a mirror is included. According to the optical laminated body 100 having the above-described configuration, the visibility is compatible at a high level. It is possible to make it.

(1) First Reflective Polarizer Layer and Second Reflective Polarizer Layer Each of the first reflective polarizer layer 10 and the second reflective polarizer layer 20 can be, for example, an anisotropic reflective polarizer. . An example of the anisotropic reflective polarizer is an anisotropic multiple thin film that transmits linearly polarized light in one vibration direction and reflects linearly polarized light in the other vibration direction. Specific examples thereof include “APF” manufactured by 3M, “DBEF” (see Japanese Patent Laid-Open No. 4-268505). Another example of the anisotropic reflective polarizer is a composite of a cholesteric liquid crystal layer and a λ / 4 plate, and a specific example thereof is “PCF” manufactured by Nitto Denko Corporation (Japanese Patent Laid-Open No. 11-231130). Etc.). Yet another example of an anisotropic reflective polarizer is a reflective grid polarizer, and a specific example thereof is a metal grid reflective polarizer (nanoscopically) that emits reflected polarized light even in the visible light region by finely processing a metal. A wire grid polarizer, see US Pat. No. 6,288,840), and a film obtained by adding metal fine particles into a polymer matrix and stretching (see JP-A-8-184701, etc.).

From the viewpoint of improving the visibility of the display device, the relative angle of the reflection axis is set to 20 to 70 °.
The relative angle of the reflection axis is preferably 25 to 65 °, more preferably 30 to 60 °, and still more preferably 35 to 55 °. When the two reflection axes intersect, two corners are formed. If the angle of one corner is α °, the angle of the other corner is (180−α) °. The relative angle of the reflection axis in this specification refers to the smaller of the two angles. That is, the minimum value that can be taken by the relative angle of the reflection axis is 0 °, and the maximum value that can be taken is 90 °.

The thicknesses of the first reflective polarizer layer 10 and the second reflective polarizer layer 20 are usually 10 to 100 μm, but preferably 10 to 50 μm from the viewpoint of reducing the thickness of the optical laminate 100 and the display device. More preferably, the thickness is 10 to 30 μm.

At least one of the first reflective polarizer layer 10 and the second reflective polarizer layer 20 may have a surface treatment layer (coating layer) or an optical layer other than the reflective polarizer layer on its outer surface. Good. The surface treatment layer is a layer formed by applying a coating liquid containing a curable resin or the like, and performing a drying treatment or a curing treatment as necessary. Examples of the surface treatment layer include a hard coat layer, an antiglare layer, a light diffusion layer, a retardation layer (a retardation layer having a retardation value of ¼ wavelength), an antireflection layer, an antistatic layer, an antifouling layer, and the like. Layer and the like. By providing a surface treatment layer (coating layer) or another optical layer, an additional function is imparted to the optical laminate 100, or the visibility of a display image when the optical laminate 100 is applied to a display device (clear) In addition, it is possible to improve the difficulty of viewing due to the reflection of outside light, the uniformity of the display image, the further improvement of rainbow unevenness, etc.).

The first reflective polarizer layer 10 and the second reflective polarizer layer 20 may have the same configuration, thickness, material, layer configuration, optical characteristics, surface treatment layer and other optical layers. It may differ in the presence or absence. Moreover, in order to give the optical laminate 100 haze in the predetermined range, at least one of the first reflective polarizer layer 10 and the second reflective polarizer layer 20 may have non-zero haze. Good. In this case, the haze of the first reflective polarizer layer 10 and / or the second reflective polarizer layer 20 is, for example, 0.1 to 5%. The first reflective polarizer layer 10 and the second reflective polarizer layer 20 may have the same haze value or may have different haze values.

The haze is the ratio of the diffuse transmittance Td to the total light transmittance Tt, and the following formula [A]: haze (%) = (Td / Tt) × 100 [A]
Is required. The total light transmittance Tt is the sum of the parallel light transmittance Tp and the diffused light transmittance Td that are transmitted coaxially with the incident light. Measured in accordance with JIS K 7136: 2000 “Plastics-Determination of Haze of Transparent Materials”.

(2) Intervening Layer The intervening layer 30 is a layer disposed between the first reflective polarizer layer 10 and the second reflective polarizer layer 20, and may have a single-layer structure or two layers. Alternatively, it may be a multilayer structure of three or more layers. In the case of a multilayer structure, two or more layers may have different hazes. The intervening layer 30 preferably has a non-zero haze. The haze of the intervening layer 30 is preferably 0.1 to 20%, more preferably 0.5 to 20%, still more preferably 0.8 to 10%, still more preferably 0.8 to It is 8%, particularly preferably 1 to 8%. Use of the intervening layer 30 having the haze in the range is suitable as one means for imparting the haze in the predetermined range to the optical laminate 100. When the haze of the intervening layer 30 exceeds 20%, the clearness of the black display tends to be reduced in black display (mirror mode), and the image tends to be whitish in white display (display mode) and the visibility tends to decrease. is there.

Examples of the method for imparting haze to the intervening layer 30 include the following methods.
a) A method of using a layer (haze imparting layer) in which particles that cause light scattering are dispersed inside the layer as the layer constituting the intervening layer 30.
b) A method of using a layer having surface irregularities (haze imparting layer) as a layer constituting the surface of the intervening layer 30.
c) A combination of a) and b) above.

The layer in which particles that cause light scattering are dispersed inside the layer and the layer having surface irregularities may be the same layer.

FIG. 2 is a schematic cross-sectional view showing another example of the optical laminate according to the present invention. In the optical laminate 200 shown in FIG. 2, the intervening layer 30 includes a base film 31 and a haze imparting layer 32 laminated on one surface thereof. That is, in the example of FIG. 2, the intervening layer 30 includes a haze-imparting layer 32 that mainly bears the expression of haze and a base film 31 that supports it. In the example of FIG. 2, the haze imparting layer 32 is provided only on one surface of the base film 31, but the intervening layer 30 includes two or more haze imparting layers, such as provided on both surfaces of the base film 31. You may have. You may have another layer (For example, an adhesive bond layer, a primer layer, a resin layer, etc.) between the base film 31 and the haze provision layer 32. FIG.

The base film 31 can be made of, for example, a thermoplastic resin, and is preferably made of a thermoplastic resin having excellent optical transparency. Specific examples of such thermoplastic resins include, for example, polyolefin resins such as chain polyolefin resins and cyclic polyolefin resins (norbornene resins, etc.); polyester resins; (meth) acrylic resins; cellulose triacetate, Cellulose ester resins such as cellulose diacetate; Polycarbonate resins; Polyvinyl alcohol resins; Polyvinyl acetate resins; Polyarylate resins; Polystyrene resins; Polyethersulfone resins; Polysulfone resins; Polyamide resins; System resins; and mixtures and copolymers thereof.

In this specification, “(meth) acryl” means at least one selected from acrylic and methacrylic. The same applies to “(meth) acryloyl”, “(meth) acrylate”, and the like.

As the chain polyolefin-based resin, polyethylene resin (polyethylene resin which is a homopolymer of ethylene or a copolymer mainly composed of ethylene), polypropylene resin (polypropylene resin which is a homopolymer of propylene, or propylene as a main component) And a copolymer composed of two or more chain olefins in addition to a chain olefin homopolymer such as

The cyclic polyolefin resin is a general term for resins that are polymerized using a cyclic olefin as a polymerization unit, and is described in, for example, JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Resin. Specific examples of cyclic polyolefin resins include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins and chain olefins such as ethylene and propylene (typically Are random copolymers), graft polymers obtained by modifying them with unsaturated carboxylic acids or their derivatives, and hydrides thereof. Among these, norbornene resins using norbornene monomers such as norbornene and polycyclic norbornene monomers as cyclic olefins are preferably used.

The polyester-based resin is a resin having an ester bond except for the following cellulose ester-based resin, and is generally made of a polycondensate of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. As the polyvalent carboxylic acid or a derivative thereof, a divalent dicarboxylic acid or a derivative thereof can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalenedicarboxylate. As the polyhydric alcohol, a divalent diol can be used, and examples thereof include ethylene glycol, propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol. A typical example of the polyester resin is polyethylene terephthalate which is a polycondensate of terephthalic acid and ethylene glycol.

The (meth) acrylic resin is a resin containing a compound having a (meth) acryloyl group as a main constituent monomer. Specific examples of the (meth) acrylic resin include, for example, poly (meth) acrylic acid esters such as polymethyl methacrylate; methyl methacrylate- (meth) acrylic acid copolymer; methyl methacrylate- (meth) acrylic acid Ester copolymer; methyl methacrylate-acrylate ester- (meth) acrylic acid copolymer; (meth) methyl acrylate-styrene copolymer (MS resin, etc.); methyl methacrylate and alicyclic hydrocarbon group And a copolymer with the compound (for example, methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.). Preferably, a polymer based on a poly (meth) acrylic acid C _1-6 alkyl ester such as poly (meth) acrylic acid methyl is used, and more preferably methyl methacrylate is used as a main component (50 to 100). % Methyl methacrylate-based resin is used.

The cellulose ester resin is an ester of cellulose and a fatty acid. Specific examples of the cellulose ester resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate. Further, these copolymers and those in which a part of the hydroxyl group is modified with other substituents are also included. Among these, cellulose triacetate (triacetyl cellulose) is particularly preferable.

Polycarbonate-based resin is an engineering plastic made of a polymer in which monomer units are bonded via a carbonate group.

The thickness of the base film 30 is usually 1 to 300 μm, and preferably 2 to 200 μm, more preferably 5 to 150 μm, and still more preferably 5 from the viewpoint of thinning the optical laminate 100 and the display device and film strength. ˜100 μm (for example, 80 μm or less).

The haze-imparting layer 32 can be a cured product layer formed by applying a curable resin composition containing a curable resin on the base film 31 and drying it as necessary. Examples of the curable resin include an active energy ray curable resin that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, an electron beam, and X-rays, and a thermosetting resin that is cured by heat. Among these, from the viewpoint of productivity, hardness of the cured product layer, and the like, the curable resin is preferably an active energy ray curable resin, and more preferably a photocurable resin such as an ultraviolet curable resin.
However, the photocurable resin may be a visible light curable resin that can be cured with visible light having a wavelength longer than that of ultraviolet rays. Moreover, it is preferable that curable resin is selected from what a hardened | cured material layer becomes high hardness (hard coat). When using a photocurable resin, the curable resin composition usually further includes a photopolymerization initiator.

Examples of the photocurable resin include urethane (meth) acrylate, polyol (meth) acrylate, and (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups. These (meth) acrylic compounds can be used alone or in combination of two or more as required.

The urethane (meth) acrylate is preferably prepared using (meth) acrylic acid and / or (meth) acrylic ester, polyol, and diisocyanate. For example, urethane (meth) acrylate is obtained by preparing hydroxy (meth) acrylate having at least one hydroxyl group from (meth) acrylic acid and / or (meth) acrylic acid ester and polyol, and reacting it with diisocyanate. be able to.
These (meth) acrylic acid and / or (meth) acrylic acid ester, polyol, and diisocyanate may be used alone or in combination of two or more.

Examples of the (meth) acrylic acid ester include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and butyl (meth) acrylate; cyclohexyl ( And cycloalkyl (meth) acrylates such as (meth) acrylate.

A polyol is a compound having at least two hydroxyl groups, such as ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, , 4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decane glycol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5- Pentanediol, hydroxypivalic acid neopentyl glycol ester, cyclohexanedimethylol, 1,4-cyclohexanediol, spiroglycol, tricyclodecanemethylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, propylene oxide De addition bisphenol A, trimethylolethane, trimethylolpropane dimethylol propane, glycerin, 3-methylpentane-1,3,5-triol, pentaerythritol, can be exemplified dipentaerythritol, tripentaerythritol, glucose ethers.

As the diisocyanate, for example, various aromatic, aliphatic or alicyclic diisocyanates can be used. Specific examples include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4,4-diphenyl diisocyanate. Xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-diphenylmethane diisocyanate, and hydrogenated products thereof.

Examples of the polyol (meth) acrylate include trimethylolpropane triacrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1 , 6-hexanediol (meth) acrylate and the like. These may be used alone or in combination.

Examples of the (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups include a (meth) acrylic polymer having a 2,3-dihydroxypropyl group, a 2-hydroxyethyl group, and a 2,3-dihydroxypropyl group. The (meth) acrylic polymer which has is mentioned.

By using a (meth) acrylic photocurable resin as exemplified above, the adhesion between the haze-imparting layer 32 and the base film 31 can be improved, and the mechanical strength is further improved. It is possible to obtain the haze imparting layer 32 that can more effectively prevent the surface from being scratched.

As the photopolymerization initiator, various types such as acetophenone, benzophenone, benzoin ether, amine, and phosphine oxide can be used. Examples of compounds classified as acetophenone photopolymerization initiators include 2,2-dimethoxy-2-phenylacetophenone (also known as benzyldimethyl ketal), 2,2-diethoxyacetophenone, 1- (4-isopropylphenyl) -2 -Hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-2-morpholino-1- (4-methylthiophenyl) propan-1-one. Examples of compounds classified as benzophenone-based photopolymerization initiators include benzophenone, 4-chlorobenzophenone, and 4,4'-dimethoxybenzophenone. Examples of compounds classified as benzoin ether photopolymerization initiators include benzoin methyl ether and benzoin propyl ether. Examples of compounds classified as amine photopolymerization initiators include N, N, N ′, N′-tetramethyl-4,4′-diaminobenzophenone (also known as Michler's ketone). Examples of the phosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyldiphenylphosphine oxide. In addition, xanthone compounds and thioxant compounds can also be used as photopolymerization initiators. Examples of typical commercially available photopolymerization initiators include “Irgacure 907”, “Irgacure 184”, and “Lucirin TPO” sold by BASF Germany.

The curable resin composition can contain a solvent as needed. As a solvent, arbitrary organic solvents which can melt | dissolve each component which comprises curable resin composition like ethyl acetate and butyl acetate can be used, for example. Two or more organic solvents can be mixed and used.

Further, the curable resin composition may contain a leveling agent, and for example, a fluorine-based or silicone-based leveling agent can be used. Examples of the silicone leveling agent include reactive silicone, polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polymethylalkylsiloxane. Among the silicone leveling agents, preferred are reactive silicone and siloxane leveling agents. By using reactive silicone, slipperiness is imparted to the surface of the haze imparting layer, and excellent scratch resistance can be maintained for a long period of time. In addition, when a siloxane leveling agent is used, film formability can be improved.

As described above, the haze imparting layer 32 may contain particles that cause light scattering.
Examples of the particles include inorganic particles such as silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate; crosslinked polyacrylic acid particles, methyl methacrylate / Examples thereof include organic particles such as styrene copolymer resin particles, crosslinked polystyrene particles, crosslinked polymethyl methacrylate particles, silicone resin particles, and polyimide particles.

As the above-mentioned particles, it is preferable to use particles having an average particle diameter of 0.1 to 10 μm and a refractive index difference with the curable resin after curing of 0.02 to 0.2. By using particles having an average particle diameter and a refractive index difference within these ranges, haze can be effectively expressed. The average particle diameter of the fine particles can be obtained by a dynamic light scattering method or the like. The average particle diameter in this case is a weight average particle diameter.

The haze imparting layer 32 having surface irregularities 1) forms a coating film by applying the curable resin composition containing the curable resin and the particles on the base film 31, and has irregularities based on the particles. Method of providing, 2) A mold (roll or the like) having a concavo-convex shape on its surface after coating a curable resin composition containing or not containing particles on the base film 31 to form a coating film ) To transfer the concavo-convex shape (also referred to as “embossing method”) or the like.

In the above method 1), a curable resin composition containing a curable resin and particles is applied onto the substrate film 31, and the coating film is cured by irradiation with light such as ultraviolet rays or heating, thereby providing a haze-imparting layer. 32 can be formed.

On the other hand, in the above method 2) (embossing method), a mold having a concavo-convex shape formed on the surface is used, and the shape of the mold is applied to the coating film (resin layer) formed on the base film 31. Transcript.
The coating film to which the uneven shape is transferred may or may not contain the particles. In the embossing method, a curable resin composition containing a photocurable resin is applied onto the base film 31, and the formed coating film is cured while being pressed against the concavo-convex surface of the mold. Is transferred to the coating film. More specifically, in the state where the curable resin composition is applied onto the base film 31 and the formed coating film is in close contact with the uneven surface of the mold, light such as ultraviolet rays is transmitted from the base film 31 side. Is applied to cure the coating film, and the substrate film 31 having the cured coating film (haze imparting layer 32) is peeled off from the mold to transfer the uneven shape of the mold to the haze imparting layer 32.

The thickness of the haze imparting layer 32 is, for example, 2 to 30 μm, and preferably 3 to 30 μm. When the thickness of the haze imparting layer 32 is less than 2 μm, sufficient hardness cannot be obtained and the surface tends to be easily damaged. When the thickness of the haze-giving layer 32 exceeds 30 μm, it tends to break or the intervening layer 30 curls due to curing shrinkage when forming the haze-giving layer 32 and the productivity tends to decrease. Also, the thickness in the above range is suitable for providing sufficient haze.

The intervening layer 30 preferably has a haze based on the haze imparting layer 32, but may have a haze based on the base film 31 together with the haze based on the haze imparted layer 32. The haze based on the base film 31 can be expressed, for example, by dispersing the above-described particles in the film.

As an example of the case where the intervening layer 30 has a single-layer structure, the intervening layer 30 can be composed of only the base film 31 in which the above-described particles are dispersed (it can be said that the intervening layer 30 is composed of only the haze imparting layer 32). . The thickness of the intervening layer 30 consisting only of the base film 31 in which the above-mentioned particles are dispersed is preferably 20 to 200 μm, more preferably 20 to 120 μm.

(3) First pressure-sensitive adhesive layer and second pressure-sensitive adhesive layer The first pressure-sensitive adhesive layer 40 and the second pressure-sensitive adhesive layer 50 are (meth) acrylic, rubber-based, urethane-based, ester-based, silicone-based, and polyvinyl ether, respectively. It can be comprised with the adhesive composition which has resin like a system as a main component. Especially, the adhesive composition which uses (meth) acrylic resin excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is suitable. The pressure-sensitive adhesive composition may be an active energy ray curable type or a thermosetting type.

Examples of the (meth) acrylic resin (base polymer) used in the pressure-sensitive adhesive composition include butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and (meth) acrylic acid 2- A polymer or copolymer having one or more (meth) acrylic acid esters such as ethylhexyl as a monomer is preferably used. The base polymer is preferably copolymerized with a polar monomer. Examples of polar monomers include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, glycidyl ( Mention may be made of monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group and the like, such as (meth) acrylate.

The pressure-sensitive adhesive composition may contain only the above base polymer, but usually further contains a crosslinking agent. As a crosslinking agent, a metal ion having a valence of 2 or more, which forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound, which forms an amide bond with a carboxyl group; Examples thereof include epoxy compounds and polyols that form ester bonds with carboxyl groups; polyisocyanate compounds that form amide bonds with carboxyl groups. Of these, polyisocyanate compounds are preferred.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by irradiation with active energy rays such as ultraviolet rays and electron beams, and has an adhesive property even before irradiation with active energy rays. It is a pressure-sensitive adhesive composition having such a property that it can be adhered to an adherend such as the like and can be cured by irradiation with active energy rays to adjust the adhesion. The active energy ray-curable pressure-sensitive adhesive composition is preferably ultraviolet curable. 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 crosslinking agent. Furthermore, if necessary, a photopolymerization initiator, a photosensitizer, and the like can be contained.

In order to impart the above-mentioned predetermined range of haze to the optical laminate 100, at least one of the first pressure-sensitive adhesive layer 40 and the second pressure-sensitive adhesive layer 50 may have a non-zero haze. In this case, the haze of the first pressure-sensitive adhesive layer 40 and / or the second pressure-sensitive adhesive layer 50 is, for example, 0.1 to 5%. The first pressure-sensitive adhesive layer 40 and the second pressure-sensitive adhesive layer 50 may have the same haze value or may have different haze values. For example, haze can be imparted to the pressure-sensitive adhesive layer by incorporating the above-described particles into the pressure-sensitive adhesive composition.

The first pressure-sensitive adhesive layer 40 and the second pressure-sensitive adhesive layer 50 may contain other additives. Examples of other additives include beads (resin beads, glass beads, etc.), glass fibers, resins other than the base polymer, tackifiers, fillers (metal powder and other inorganic powders, etc.), antioxidants, Examples include ultraviolet absorbers, dyes, pigments, colorants, antifoaming agents, corrosion inhibitors, and photopolymerization initiators.

The thicknesses of the first pressure-sensitive adhesive layer 40 and the second pressure-sensitive adhesive layer 50 can be 1 to 40 μm, respectively. However, the thickness of the optical laminate 100 and the display device can be reduced, and the dimensions can be maintained while maintaining good processability. From the viewpoint of suppressing the change, the thickness is preferably 3 to 25 μm (for example, 3 to 20 μm, more preferably 3 to 15 μm).

The first pressure-sensitive adhesive layer 40 and the second pressure-sensitive adhesive layer 50 may have the same configuration, or may differ in thickness, material, optical characteristics such as light diffusibility, and the like.

The first pressure-sensitive adhesive layer 40 and the second pressure-sensitive adhesive layer 50 can be formed by applying an organic solvent diluted solution of the pressure-sensitive adhesive composition on a substrate and drying it. The base material can be the first reflective polarizer layer 10, the second reflective polarizer layer 20, the intervening layer 30, a separate film (release film), or the like. When the active energy ray-curable pressure-sensitive adhesive composition is used, a pressure-sensitive adhesive layer having a desired degree of curing can be obtained by irradiating the formed pressure-sensitive adhesive layer with active energy rays.

As the separate film, a film in which a release treatment is applied to the surface on which the pressure-sensitive adhesive layer is laminated can be used. Examples of the mold release treatment are silicone treatment, long chain alkyl treatment, fluorine treatment and the like. The material of the film is, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, or a polyester resin such as polyethylene terephthalate.

(4) Modification of Optical Laminate Referring to FIG. 3, the optical laminate is a pressure-sensitive adhesive layer that is laminated on at least one outer surface of the first reflective polarizer layer 10 and the second reflective polarizer layer 20. The third pressure-sensitive adhesive layer 60 can be further included. The 3rd adhesive layer 60 can be used in order to bond an optical laminated body to another member. Examples of the other member include other optical films and any optical member included in the display device (image display device), for example, an optical member disposed on the outermost surface of the display device (image display device). it can. Regarding the specific configuration of the third pressure-sensitive adhesive layer 60, the description of the above (3) about the first pressure-sensitive adhesive layer 40 and the second pressure-sensitive adhesive layer 50 is cited.

In the optical laminate 300 shown in FIG. 3, the third pressure-sensitive adhesive layer 60 is laminated on the outer surface of the first reflective polarizer layer 10. However, the present invention is not limited to this, and the second reflective polarizer is used. It may be laminated on the outer surface of the layer 20, or may be laminated on both the outer surface of the first reflective polarizer layer 10 and the outer surface of the second reflective polarizer layer 20.

An optical laminate having a three-layer structure in which the first reflective polarizer layer 10 and the second reflective polarizer layer 20 are bonded via an adhesive layer can also be an optical laminate according to the present invention. In this case, the pressure-sensitive adhesive layer corresponds to an intervening layer (haze imparting layer). In this embodiment, the pressure-sensitive adhesive layer is preferably a light-diffusible pressure-sensitive adhesive layer containing the above-described particles in order to give the optical laminate a haze in the predetermined range. In this case, the haze of the optical layered body can be adjusted by adjusting the content of the particles.

¡An adhesive layer may be used instead of the adhesive layer. As the adhesive for forming the adhesive layer, the adhesive described in (5) described later can be similarly used. Similarly, in the case of using an adhesive layer, the adhesive layer is a light diffusing adhesive layer containing the above-described particles in order to give the optical laminate a haze in the predetermined range. Is preferred.

Referring to FIG. 4, the optical laminate may further include a base material layer 70 disposed on the outer side of the first reflective polarizer layer 10 or the outer side of the second reflective polarizer layer 20. The base material layer 70 is a member that supports the optical laminate. In the optical laminate 400 shown in FIG. 4, the base material layer 70 is laminated on the first reflective polarizer layer 10 side, but is not limited to this, and the second reflective polarizer layer 20 side is not limited thereto. It may be laminated.

The substrate layer 70 is not particularly limited, and examples thereof include a glass plate and a thermoplastic resin film. The base material layer 70 is typically a member disposed on the outermost surface of the display device, for example, an absorption-type polarizing plate disposed on the viewing side of the display device; a viewing side of the viewing-side absorption polarizing plate And a front plate disposed on the outermost surface of the display device; a touch panel element disposed on the outermost surface of the touch input type display device, and the like.

The absorption polarizing plate may include at least a polarizer in which a dichroic dye such as iodine or a dichroic organic dye is adsorbed and oriented on a stretched polyvinyl alcohol-based resin film. The absorption polarizing plate may be one in which a protective film made of a thermoplastic resin or the like is bonded to one side or both sides of a polarizer. The thickness of the polarizer is, for example, 2 to 30 μm, preferably 2 to 10 μm. The thickness of the protective film is, for example, 2 to 150 μm, preferably 5 to 100 μm. The protective film may be a retardation film.

(5) Manufacturing method of optical laminated body The optical laminated body 100 shown by FIG. 1 laminates | stacks the 1st reflection type polarizer layer 10 on the one surface of the interposition layer 30 via the 1st adhesive layer 40, and interposes. It can be produced by laminating the second reflective polarizer layer 20 on the other surface of the layer 30 via the second pressure-sensitive adhesive layer 50. Prior to the lamination of these layers, the bonding surface of the first reflective polarizer layer 10 with the first pressure-sensitive adhesive layer 40, the bonding surface of the intervening layer 30 with the first pressure-sensitive adhesive layer 40, and the intervening layer 30. At least one bonding surface selected from the group consisting of a bonding surface with the second pressure-sensitive adhesive layer 50 and a bonding surface with the second pressure-sensitive adhesive layer 50 in the second reflective polarizer layer 20, preferably 2. You may perform a surface activation process to the above bonding surface, More preferably, all the bonding surfaces. In addition to or instead of these bonding surfaces, the bonding surface with the first reflective polarizer layer 10 in the first pressure-sensitive adhesive layer 40 and the intervening layer 30 in the first pressure-sensitive adhesive layer 40. Selected from the group consisting of: a bonding surface with the second reflective polarizer layer 20 in the second pressure-sensitive adhesive layer 50; and a bonding surface with the intervening layer 30 in the second pressure-sensitive adhesive layer 50. The surface activation treatment may be performed on at least one bonding surface, preferably two or more bonding surfaces, more preferably all bonding surfaces. The surface activation treatment is advantageous for obtaining an optical layered body that is less susceptible to delamination and has excellent wet heat durability.

As the surface activation treatment, dry treatment such as corona treatment, plasma treatment, discharge treatment (glow discharge treatment, etc.), flame treatment, ozone treatment, UV ozone treatment, ionizing active ray treatment (ultraviolet treatment, electron beam treatment, etc.) And wet treatment such as ultrasonic treatment using a solvent such as water and acetone, alkali treatment, and anchor coat treatment. These processes may be performed alone or in combination of two or more. Among these, corona treatment and plasma treatment are preferable for continuously treating the film unwound from the film roll.

The first reflective polarizer layer 10 and the second reflective polarizer layer 20 may be bonded to the intervening layer 30 using an adhesive. In this case, an adhesive layer is disposed between the first reflective polarizer layer 10 and the intervening layer 30 and between the second reflective polarizer layer 20 and the intervening layer 30. The first reflective polarizer layer 10 and the second reflective polarizer layer 20 may be bonded to the intervening layer 30 through one adhesive layer and the other through an adhesive layer. .

The adhesive forming the adhesive layer includes an active energy ray-curable adhesive containing a curable compound that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays (preferably ultraviolet curing) Adhesive) and an aqueous adhesive in which an adhesive component such as a polyvinyl alcohol resin is dissolved or dispersed in water.

The curable compound can be a cationic polymerizable curable compound or a radical polymerizable curable compound. Examples of the cationic polymerizable curable compound include an epoxy compound (a compound having one or more epoxy groups in the molecule) and an oxetane compound (one or two or more oxetane rings in the molecule). Or a combination thereof. Examples of the radical polymerizable curable compound include (meth) acrylic compounds (compounds having one or more (meth) acryloyloxy groups in the molecule) and radical polymerizable double bonds. Other vinyl compounds or combinations thereof can be mentioned. A cationic polymerizable curable compound and a radical polymerizable curable compound may be used in combination. The active energy ray-curable adhesive usually further includes a cationic polymerization initiator and / or a radical polymerization initiator for initiating a curing reaction of the curable compound.

The optical layered body according to the modified example described in (4) above can also be manufactured in the same manner as described above.

(6) Characteristics of optical laminated body, etc. According to the optical laminated body according to the present invention, the occurrence of rainbow unevenness can be effectively suppressed even when the optical laminated body is arranged on the viewing side of the display device, and good visual recognition is achieved. Can give sex. As described above, the visibility here means that the display device is turned on and the screen is displayed in white (display mode), and the image is displayed when the display device is used as a device for displaying an image on the screen. Visibility and visibility when the power is turned off and the screen is displayed in black (mirror mode) and the display device is used as a mirror are included.

The visibility in the white display (display mode) mainly means the sharpness of the image (transmission image) projected on the screen. The visibility in the black display (mirror mode) mainly means the sharpness of the reflected image reflected on the screen and its hue.

In order to improve the visibility in black display (mirror mode), the surface of the optical laminate (the surface directed outward when applied to a display device) preferably has good reflection characteristics. The reflection characteristic can be evaluated as a reflection luminance rate. And the reflection luminance factor is that of the measured luminous reflectance R _SCI in the regular reflection inclusive manner. According to the optical layered body of the present invention, it is possible to achieve both high visibility in white display (display mode) and high reflection luminance rate (thus high visibility in black display (mirror mode)). It is.

Measurement method of the measured luminous reflectance R _SCI for a positive reflection light inclusive method will be described with reference to FIG. FIG. 5 is a cross-sectional view schematically showing an optical system for measuring the luminous reflectance _RSCI . The optical system shown in FIG. 5 is a diffuse illumination optical system. The diffuse illumination method is a method of illuminating a measurement sample uniformly from all directions using an integrating sphere. In FIG. 5, an integrating sphere 80 (white paint such as barium sulfate that diffuses and reflects light almost completely on the inner surface is used. Spheres coated on) are installed. The light emitted from the light source 81 is diffused inside the integrating sphere 80 and reflected by the surface of the measurement sample 82. Since the optical system shown in FIG. 5 is configured so that light in all directions including light in the specular reflection direction with respect to the light receiving unit is incident on the surface of the measurement sample, it is referred to as a specular reflection light entering mode (SCI) mode. .

On the other hand, a light trap (the light entering here is absorbed and does not return into the integrating sphere 80) is installed at the position of the integrating sphere 80 in the regular reflection direction with respect to the light receiving unit. The optical system configured so that light in the regular reflection direction does not strike the surface of the measurement sample with respect to the light receiving unit is called a regular reflection light removal mode (SCE mode).

The optical spectrum shown in FIG. 5 is used to obtain the reflection spectrum of the measurement sample, and the visual sensation calculated from this reflection spectrum according to the method defined in JIS Z8722: 2009 “Color Measurement Method—Reflection and Transmission Object Color” reflectance, a luminous reflectance R _SCI measured by specular light included schemes.

The reflection luminance rate of the optical laminate is preferably 55% or more, and may be 60% or more. The reflection luminance rate is preferably 85% or less, and may be 80% or less. Having a reflection luminance rate in the above range is advantageous in achieving both visibility in white display (display mode) and black display (mirror mode).

<Display device>
The optical layered body can be applied to a display device. The display device (image display device) preferably includes a display element (image display element) and the optical layered body disposed on the viewing side. According to the optical layered body of the present invention, it is possible to effectively suppress the occurrence of rainbow unevenness even when it is disposed on the viewing side of the display device, and it is possible to provide good visibility.

The display element is not particularly limited, and examples thereof include a liquid crystal cell in a liquid crystal display device, an organic EL element in an organic EL device, and a touch panel element in a touch input display device. Attachment of the optical laminate to the display device can be performed via an adhesive layer (for example, the third adhesive layer 60).

When the display device has an absorptive polarizing plate on the viewing side of the display element and the optical laminate is disposed on the viewing side, the first reflective polarizer layer 10 and the second reflective type included in the optical laminate. The angle formed by the reflection axis of the reflective polarizer layer disposed closer to the absorption polarizing plate in the polarizer layer 20 and the absorption axis of the absorption polarizing plate is preferably about 0 °. . “Abbreviated” means to allow a deviation within a range of ± 10 °, preferably ± 5 °.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

<Example 1>
(1) Preparation of UV-curable resin composition Contains pentaerythritol triacrylate and polyfunctional urethanized acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate), and the weight ratio of the former / the latter is 60/40 An ultraviolet curable resin composition 1 was prepared, which was dissolved in ethyl acetate so that the total concentration of both was 60% by weight, and a leveling agent was further blended. The pentaerythritol triacrylate and polyfunctional urethanized acrylate contained in the ultraviolet curable resin composition 1 are collectively referred to as a “curable component”. 1 part by weight of methyl methacrylate / styrene copolymer resin particles having an average particle diameter of 2.7 μm is added to 100 parts by weight of the curable component of the ultraviolet curable resin composition 1 and dispersed therein. The resin particles were diluted with ethyl acetate so that the total concentration of the resin particles was 30% by weight to obtain an ultraviolet curable resin composition 2. 1 part by weight of a photopolymerization initiator (trade name “Irgacure (registered trademark) 184” manufactured by Ciba) is added to 100 parts by weight of the curable acrylate to the ultraviolet curable resin composition 2 to obtain an ultraviolet curable resin. Composition 3 was obtained.

The refractive index of the cured product obtained by adding 1 part by weight of the photopolymerization initiator to 100 parts by weight of the curable acrylate to the ultraviolet curable resin composition 1 and curing it by irradiating with ultraviolet rays is 1. 53. The refractive index of the methyl methacrylate / styrene copolymer resin particles was 1.49. Therefore, the refractive index difference between them was 0.04.

(2) Production of a film having a laminated structure of a base film and a cured product layer On the surface of a triacetyl cellulose (TAC) film (trade name “TD60” manufactured by Fuji Film Co., Ltd., thickness 60 μm) as a base film The UV curable resin composition 3 prepared in the above (1) was applied so that the film thickness after drying was 5 μm, and held for 3 minutes in a dryer set at 60 ° C. Dried. After drying, the coating film of the UV curable resin composition 3 is cured by irradiating UV light from a high pressure mercury lamp with an intensity of 20 mW / cm ² to 200 mJ / cm ^{2 in} terms of h-ray equivalent from the film coating side of the film. Thus, a film having a laminated structure of a base film and a cured product layer (haze imparting layer) was obtained.

An optically transparent (meth) acrylic pressure-sensitive adhesive layer is bonded to the surface of the base film of a film having a laminated structure of the base film and the cured product layer, and the optical laminate is not formed via this pressure-sensitive adhesive layer. The sample was bonded to an alkali glass substrate (trade name “Eagle XG” manufactured by Corning) and used as a measurement sample. With respect to this measurement sample, light is incident from the glass substrate side, and a haze meter “HM-150” manufactured by Murakami Color Research Laboratory Co., Ltd. conforming to JIS K 7136: 2000 “How to determine haze of plastic-transparent material”. When the haze was measured using a mold, it was 1.0%.

(3) Production of optical layered body A 20 cm × 30 cm sheet is cut out from a reflective polarizer (trade name “APF-v3” manufactured by 3M, thickness 26 μm), and this is cut into a first reflective polarizer layer. did. In the first reflective polarizer layer, the angle formed between the short side and the reflection axis is 0 °. A sheet body having a size of 20 cm × 30 cm was cut out from the reflective polarizer and used as a second reflective polarizer layer. In the second reflective polarizer layer, the angle formed between the short side and the reflection axis is 50 °. A sheet of 20 cm × 30 cm size was cut out from the film having a laminated structure of the base film and the cured product layer obtained in (2) above, and this was used as an intervening layer.

The intervening layer was laminated on the first reflective polarizer layer via a (meth) acrylic pressure-sensitive adhesive layer (20 cm × 30 cm size) having a thickness of 20 μm. At this time, the intervening layer was laminated so that the base film of the intervening layer was in contact with the (meth) acrylic pressure-sensitive adhesive layer. Prior to lamination, corona treatment was applied to the bonding surface of the first reflective polarizer layer with the pressure-sensitive adhesive layer and the bonding surface of the intervening layer with the pressure-sensitive adhesive layer. Next, a second reflective polarizer layer is laminated on the intervening layer via a (meth) acrylic pressure-sensitive adhesive layer (20 cm × 30 cm size) having a thickness of 20 μm to obtain an optical laminate having a size of 20 cm × 30 cm. It was. Prior to lamination, corona treatment was applied to the bonding surface of the second reflective polarizer layer with the adhesive layer and the bonding surface of the intervening layer with the adhesive layer. The angle formed by the reflection axis of the first reflective polarizer layer and the reflection axis of the second reflective polarizer layer (relative angle of the reflection axis) is 50 °.

(4) Measurement of reflection luminance factor of optical laminated body An optically transparent (meth) acrylic pressure-sensitive adhesive layer is bonded to the outer surface of the first reflective polarizer layer of the optical laminated body, and this pressure-sensitive adhesive layer is interposed therebetween. The optical laminate was bonded to a black acrylic plate and used as a measurement sample. Using this spectrophotometer (“CM-2600d” manufactured by Konica Minolta Co., Ltd.), the measurement sample is measured in the SCI mode at a temperature of 23 ° C., so that the visual sensation measured in the specular reflection light-incorporated method. The reflection luminance rate was obtained as the reflectance R _SCI . The results are shown in Table 1.

(5) Measurement of haze of optical laminated body A (meth) acrylic pressure-sensitive adhesive layer is bonded to the outer surface of the first reflective polarizer layer of the optical laminated body, and the optical laminated body is alkali-free through this pressure-sensitive adhesive layer. This was bonded to a glass substrate (trade name “Eagle XG” manufactured by Corning) and used as a measurement sample. With respect to this measurement sample, light is incident from the glass substrate side, and a haze meter “HM-150” manufactured by Murakami Color Research Laboratory Co., Ltd. conforming to JIS K 7136: 2000 “Plastics—How to Obtain Haze of Transparent Materials” The haze was measured using a mold. The results are shown in Table 1.

(6) Evaluation of rainbow unevenness of optical laminated body An optically transparent (meth) acrylic pressure-sensitive adhesive layer is bonded to the outer surface of the first reflective polarizer layer of the optical laminated body, and the adhesive layer is interposed therebetween. The optical laminate was bonded to a black acrylic plate and used as a measurement sample. The light from the three-wavelength tube fluorescent lamp is incident on the surface of the second reflective polarizer layer of this measurement sample at an incident angle of 60 ° and 90 ° with respect to the surface, and the three-wavelength tube fluorescence reflected on the surface is reflected. It was visually observed whether or not rainbow unevenness occurred in the lamp image. The results are shown in Table 1. When no rainbow unevenness is observed at any incident angle, “AA”, when almost no rainbow unevenness is observed at any incident angle, “A”, rainbow unevenness is recognized at at least one incident angle. The case where it was answered was designated as “B”.

(7) Evaluation of visibility An optically transparent (meth) acrylic pressure-sensitive adhesive layer is bonded to the outer surface of the first reflective polarizer layer of the optical layered body, and the optical layered body is attached via this pressure-sensitive adhesive layer. IPS mode liquid crystal display (bonded on the screen of LG Electronics, product name “22MP57VQ-P”. At this time, the reflection axis of the first reflective polarizer layer and the viewing side polarization of the liquid crystal display Bonding was performed so that the absorption axis of the plate was parallel, the liquid crystal display device was turned on, the screen was displayed in white (display mode), characters were input, and this was displayed on the screen. The visibility of the characters (visibility of the transmission image) was visually evaluated, and the results are shown in the columns of “Evaluation of Visibility” and “Transmission Image” in Table 1. A case where the characters could be viewed very clearly was “AA” ”,“ A ”when the character was clearly visible, and the character was unclear The case was designated as “B”.

In addition, the power of the liquid crystal display device was turned off to display the screen in black, and the visibility of the reflected image in the mirror mode was visually evaluated. The results are shown in the columns “Evaluation of visibility” and “Reflected image” in Table 1. “AA” when the reflected image and its color are very clear, “A” when the reflected image and its color are clear, and “B” when the reflected image or its color is unclear. did.

<Examples 2 to 9, Comparative Examples 1 to 4>
An optical layered body was prepared in the same manner as in Example 1 except that the configuration of the intervening layer, the haze of the intervening layer, and the relative angle of the reflection axis were as shown in Table 1. 1) (4) to (7) were measured and evaluated. The results are shown in Table 1. The measurement result of the haze of the intervening layer is also shown in Table 1. The haze of the intervening layer was adjusted by changing the amount of methyl methacrylate / styrene copolymer resin particles added to the ultraviolet curable resin composition 1. The thickness of the cured product layer is the same as in Example 1. In Comparative Examples 1 to 3, the cured product layer of the intervening layer does not contain methyl methacrylate / styrene copolymer resin particles.

In Table 1, “AC film” means a (meth) acrylic resin film having a thickness of 100 μm. “COP film” means a cyclic polyolefin resin film having a thickness of 100 μm.

<Comparative Examples 5 to 9>
As an intervening layer, an optically transparent (meth) acrylic pressure-sensitive adhesive layer having a thickness of 20 μm (referred to as “transparent pressure-sensitive adhesive layer” in Table 1) and the relative angle of the reflection axis are shown in Table 1. An optical layered body was produced in the same manner as in Example 1 except that it was as described above, and the measurements and evaluations (4) to (7) in Example 1 were carried out in the same manner as in Example 1. The results are shown in Table 1.

<Comparative Examples 10 and 11>
An optical laminate was prepared in the same manner as in Example 1 except that a light-diffusing pressure-sensitive adhesive layer having a thickness of 20 μm was used as the intervening layer, and (4) to (7) in Example 1 as in Example 1. ) Was measured and evaluated. The results are shown in Table 1. The light diffusing pressure-sensitive adhesive layer is obtained by dispersing light diffusing particles in an optically transparent (meth) acrylic pressure-sensitive adhesive layer. The haze of the light diffusing pressure-sensitive adhesive layer was adjusted by changing the addition amount of the light diffusing particles.

10 First reflective polarizer layer, 20 Second reflective polarizer layer, 30 Intervening layer, 31 Base film, 32 Haze imparting layer, 40 First adhesive layer, 50 Second adhesive layer, 60 Third adhesive Agent layer, 70 base layer, 80 integrating sphere, 81 light source, 82 measurement sample, 100, 200, 300, 400 optical laminate.

Claims

A first reflective polarizer layer, a second reflective polarizer layer, and an intervening layer disposed between the first reflective polarizer layer and the second reflective polarizer layer,
The angle formed by the reflection axis of the first reflective polarizer layer and the reflection axis of the second reflective polarizer layer is 20 ° or more and 70 ° or less,
An optical laminate having a haze of 0.4% to 20%.
The optical laminate according to claim 1, wherein the reflection luminance ratio is 55% or more and 85% or less.
The optical laminated body according to claim 1 or 2, wherein the haze of the intervening layer is 0.8% or more and 20% or less.
4. The optical laminate according to claim 1, wherein the intervening layer includes two or more layers.
The optical laminate according to claim 4, wherein the two or more layers have different hazes.
The optical laminate according to any one of claims 1 to 5, further comprising a base material layer disposed outside the first reflective polarizer layer or outside the second reflective polarizer layer.
The optical layered body according to claim 6, wherein the base material layer includes an absorptive polarizer layer.
The optical laminate according to any one of claims 1 to 7, further comprising an adhesive layer laminated on at least one outer surface of the first reflective polarizer layer and the second reflective polarizer layer.
The optical laminated body according to any one of claims 1 to 8, which is disposed on the viewing side of the display element.