TW202321742A - Optical laminate and image display device - Google Patents

Abstract

This inventnion provides an optical laminate and an image display device including the optical laminate , wherein the optical laminate can be used as a circularly polarizing plate, and when the optical laminate is applied in an image display device, it is difficult to visually recognize a slight leakage of internally reflected light due to a slight in-plane fluctuation of hue of the reflected light in the circularly polarizing plate while a sufficiently low reflectance is maintained.

This invention provides an optical laminate and an image display device including the optical laminate , wherein the optical laminate includes an optical functional layer (A), a linear polarizer, and a retardation layer having reverse wavelength dispersion in this order, and in the optical functional layer (A), the ratio of the reflectance R (450) at a wavelength of 450 nm to the reflectance R (550) at a wavelength of 550 nm: R (450)/R (550) is 1.07 or more and 1.55 or less, and the reflectance R(550) is less than 6.0%

Description

Optical laminate and image display device

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

In an image display device represented by an organic electroluminescent display device, in order to suppress a decrease in visibility due to reflection of external light, it is known to improve antireflection performance by using a circular polarizing plate or the like [for example, JP-A 2020 -134934 gazette (Patent Document 1)]. The circular polarizer is an optical laminate including a linear polarizer and a retardation layer.

[Prior Art Literature]

[Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2020-134934

Circular polarizers are generally arranged on the viewing side of image display elements such as organic electroluminescent display elements. By arranging the circular polarizing plate in this way, external light incident on the image display element is reflected by internal electrodes and the like included in the element, and internally reflected light emitted to the outside can be suppressed. In particular, it is known that Ruoyuan When the polarizing plate is composed of a λ/4 layer having reverse wavelength dispersion, internally reflected light is suppressed in a wide visible range, so it is easy to realize black display (the reflection hue of the circular polarizing plate is made neutral).

However, the more neutral the reflection hue of the circular polarizing plate is, the more a little leakage of internally reflected light (hereinafter also referred to as “slight light leakage”) due to a slight deflection of the reflection hue in the plane of the circular polarizing plate is caused. Problems that are easily seen as uneven.

The object of the present invention is to provide an optical laminate that can be used as a circular polarizing plate. When the optical laminate is applied to an image display device, sufficiently small reflectance is ensured, and the above-mentioned slight light leakage is difficult to be recognized. Another object of the present invention is to provide an image display device including the optical layered body.

The present invention provides the following optical layered body and image display device.

[1] An optical laminate comprising an optical functional layer (A), a linear polarizer, and a retardation layer having reverse wavelength dispersion in sequence, wherein,

The ratio of the reflectance R(450) of the aforementioned optical functional layer (A) at a length of 450nm to the reflectance R(550) at a wavelength of 550nm: R(450)/R(550) is not less than 1.07 and not more than 1.55,

The aforementioned reflectance R (550) was less than 6.0%.

[2] The optical laminate according to [1], wherein the optical function layer (A) includes a high refractive index layer having a refractive index of 1.6 or higher at a wavelength of 550 nm.

[3] The optical laminate according to [2], wherein the optical function layer (A) includes a base film and the high refractive index layer laminated thereon.

[4] The optical laminate according to any one of [1] to [3], wherein the ratio of the reflectance R(450) to the reflectance R(550) is: R(450)/R(550 ) is not less than 1.07 and not more than 1.35.

[5] The optical laminate according to any one of [1] to [4], wherein the retardation layer includes one or more liquid crystal cured layers.

[6] The optical laminate according to any one of [1] to [5], wherein the optical function layer (A) further includes a front plate.

[7] The optical laminate according to any one of [1] to [6], further comprising a pressure-sensitive adhesive (PSA) disposed on the opposite side of the retardation layer to the linear polarizer. , also known as pressure-sensitive adhesive) layer.

[8] The optical laminate according to [7], further comprising a separation film arranged on the side of the pressure-sensitive adhesive layer opposite to the retardation layer.

[9] The optical laminate according to any one of [1] to [8], further comprising a protective film on the surface of the optical function layer (A) opposite to the linear polarizer.

[10] An image display device comprising the optical laminate described in any one of [1] to [9].

The present invention provides an optical layered body that can be used as a circular polarizing plate, and an image display device containing the optical layered body. When the optical layered body is applied to an image display device, sufficiently small reflectance is ensured, and the above-mentioned A little light leakage is hard to see.

1: Optical functional layer (A)

1a: High refractive index layer

1b: Substrate film

2: Linear polarizer

3: phase difference layer

3a: The first retardation layer

3b: The second retardation layer

3c: The fifth bonding layer

10: The first bonding layer

11: Thermoplastic resin film

12: Protective film

20: The second bonding layer

30: The third bonding layer

40: The 4th bonding layer

50: Adhesive layer

60: Separation membrane

70: protective film

80: 6th bonding layer

90: front panel

100: Image display components

Fig. 1 is a schematic sectional view showing an example of an optical layered body according to the present invention.

Fig. 2 is a schematic sectional view showing another example of the optical layered body according to the present invention.

Fig. 3 is a schematic sectional view showing another example of the optical layered body according to the present invention.

Fig. 4 is a schematic sectional view showing another example of the optical layered body according to the present invention.

Fig. 5 is a schematic sectional view showing another example of the optical layered body according to the present invention.

Fig. 6 is a schematic cross-sectional view showing an example of an image display device according to the present invention.

Hereinafter, embodiments of the present invention will be described while referring to the drawings, but the present invention is not limited to the following embodiments. All the drawings below are shown to help the understanding of the present invention, and the size or shape of each constituent element shown in the drawing is not necessarily consistent with the size or shape of the actual constituent elements.

<Optical laminate>

According to the present invention, the optical layered body (hereinafter referred to simply as "optical layered body") can be used as a circular polarizer, and sequentially includes an optical function layer (A), a linear polarizer, and a retardation layer with reverse wavelength dispersion layer. The term "circular polarizing plate" includes elliptic circular polarizing plates.

Fig. 1 is a schematic sectional view showing an example of an optical laminate according to the present invention. The optical multilayer system shown in FIG. 1 includes an optical function layer (A) 1 , a linear polarizer 2 and a retardation layer 3 having reverse wavelength dispersion. The optical function layer (A) 1 and the linear polarizer 2 can be laminated via the first bonding layer 10 . The linear polarizer 2 and the retardation layer 3 can be laminated via the second bonding layer 20 . When this optical layered body is applied to an image display device (organic EL display device, etc.), it is to make the optical function layer (A) 1 side of the optical layered body be the viewing side, that is, to make the retardation layer 3 side In the form of an image display element (organic electroluminescent display element, etc.) side, it is arranged on the viewing side of the image display element.

The constituent elements contained or may be contained in the optical layered body will be described in detail below.

(1) Optical functional layer (A)

The optical function layer (A) is a layer disposed on the viewing side of the linear polarizer 2 and has the following reflective properties.

[a] The ratio of the reflectance R(450) at a wavelength of 450nm to the reflectance R(550) at a wavelength of 550nm is (reflectance R(450)/reflectance R(550). The reflectance ratio") is not less than 1.07 and not more than 1.55.

[b] The reflectance R (550) is less than 6.0%.

The optical functional layer (A) generally has a laminated structure. When the reflectance of the first bonding layer 10 is a meaningful value, the layered structure constituted by the optical function layer (A) 1 and the first bonding layer 10, that is, the layer disposed on the viewing side of the linear polarizer 2 The laminated structure of all the layers conforms to "optical function layer (A)". On the other hand, when the reflectance of the first bonding layer 10 is not a meaningful value, that is, when the reflection properties of the optical function layer (A) 1 and the reflection properties of the above-mentioned laminated structure are substantially equal, the The optical function layer (A) 1 is regarded as an optical function layer (A).

By disposing the optical functional layer (A) 1 having the above-mentioned reflective properties on the viewing side of the linear polarizer 2, the reflected light reflected on the viewing side surface of the optical laminate can be changed into a blue color, so The above-mentioned slight light leakage can be made difficult to recognize. The optical layered body according to the present invention is equipped with a retardation layer having reverse wavelength dispersion, and therefore the internal reflection is greatly suppressed, so the reflection on the viewing side surface of the optical layered body is controlled by the setting of the optical function layer (A) 1 The method of the present invention of reflected light is effective in making a little light leakage difficult to recognize. On the other hand, even if the optical function layer (A) 1 is arranged on the viewing side of the linear polarizer 2 , the transmitted light (white display) from the image display element can be suppressed from changing to a bluish color.

By adjusting the retardation properties of the retardation layer with the circular polarizer, the reflection hue of the circular polarizer may also have a blue color. For example, it can be changed to a bluish color by increasing the wavelength dispersion α. However, in this case, there arises another problem that the change of the reflection hue from an inclination becomes large. According to the method of disposing the optical function layer (A) 1 having the above-mentioned reflective properties on the viewing side of the linear polarizer 2 , such problems will not occur, and a little light leakage can be made difficult to recognize.

In addition, the wavelength dispersion α refers to the ratio of the in-plane retardation value Re(450) in a wavelength of 450 nm to the in-plane retardation value Re(550) in a wavelength of 550 nm.

Wavelength dispersion α = in-plane retardation value Re(450)/in-plane retardation value Re(550)

Also, according to the optical layered body of the present invention, since the reflection hue of the optical layered body can be changed to a moderately bluish color, it is possible to give a sense of luxury to the display of an image display device. The degree of blue in the reflection hue can be controlled by adjusting the reflectance R(450), reflectance R(550) and/or their reflectance ratio within the above range.

From the viewpoint of making a little light leakage difficult to see and/or the viewpoint of making the reflectance Y of the optical laminate moderately small, the reflectance is preferably from 1.07 to 1.45, more preferably from 1.07 to 1.35, and still more Preferably it is not less than 1.10 and not more than 1.35, and even more preferably is not less than 1.12 and not more than 1.35. When the reflectance ratio exceeds 1.55, the blue of the reflection hue of the optical layered body tends to become too strong. If the reflectance ratio is less than 1.07, the effect of making a little light leakage hard to recognize cannot be acquired.

The reflectance R(550) is preferably 5.8% or less, more preferably 5.6% or less, still more preferably 5.4% or less from the viewpoint of appropriately reducing the reflectance Y of the optical layered body. When the reflectance R (550) is 6.0% or more, the reflectance Y of the optical layered body becomes too large, and the visibility of the image display device tends to decrease. The reflectivity R(550) can be 0.0%, generally greater than 0.0%, such as 0.1% or more, preferably 1.0% or more, more preferably 4.0% or more, and more preferably 4.2% or more.

From the viewpoint of making a little light leakage difficult to see and/or moderately reducing the reflectance Y of the optical laminate, the reflectance R (450) is preferably 4.0% or more and 10.0% or less, more preferably 4.5 % to 9.0%, and more preferably 5.0% to 8.0%.

From the viewpoint of the visibility of the image display device, the reflectance Y of the optical laminate is preferably less than 6.0%, more preferably 5.9% or less, further preferably 5.8% or less, even more preferably 5.7% or less . The reflectance Y is generally 4.0% or more.

The reflectance R(450) and reflectance R(550) of the optical function layer (A), and the reflectance Y of the optical layered body can be measured by the method described in the item of [Example] mentioned later.

The optical functional layer (A) 1 may include, for example, a high-refractive index layer, a pigment-containing layer (for example, a yellow pigment-containing layer), an alternating multilayer of high-refractive-index layers and low-refractive-index layers, a liquid crystal layer, a fluorescent layer, and the like. etc. combinations etc. The high-refractive index layer realizes the above-mentioned reflective properties by utilizing interfacial reflection. The pigment-containing layer is, for example, a layer that contains a pigment that absorbs yellow light and enhances the blue color of reflected light. The alternating multilayer of high refractive index layer and low refractive index layer utilizes interfacial reflection in the interface of high refractive index layer and low refractive index layer to achieve the above reflective properties. The liquid crystal layer realizes the above-mentioned reflective properties by utilizing, for example, the reflection of circularly polarized light caused by cholesteric liquid crystals. Among them, from the viewpoint of the ease of operation and ease of production of the optical functional layer (A) having the above-mentioned reflective properties, the viewpoint of the ease of operation of adjusting the reflection hue of the optical laminate, and the transmission from the image display element It is preferable that the optical function layer (A) 1 contains a high-refractive-index layer from the viewpoint that a non-colored one is preferable for light transmission.

A conventionally known structure can be used for a high-refractive-index layer, Preferably, the layer which made the refractive index imparting agent dispersed in the binder resin is mentioned. Examples of the refractive index imparting agent include particles made of metal oxides such as zirconia, titanium oxide, tin oxide, zinc oxide, indium tin oxide, indium oxide, aluminum oxide, silicon oxide, yttrium oxide, and antimony oxide. The average particle size of the particles is, for example, not less than 0.01 nm and not more than 100 nm, preferably not less than 0.1 nm and not more than 50 nm.

From the viewpoint of the refractive index of the high refractive index layer and the ease of film formation of the layer, the content of the refractive index imparting agent in the high refractive index layer is preferably 10% by mass or more in 100% by mass of the high refractive index layer 90 mass % or less, more preferably 20 mass % or more and 80 mass % or less, more preferably 30 mass % or more and 70 mass % or less, even more preferably 40 mass % or more and 60 mass % or less. The refractive index of the high refractive index layer can be adjusted by the content of the refractive index imparting agent in the high refractive index layer. The higher the content of the refractive index imparting agent in the high refractive index layer is, the higher the refractive index of the high refractive index layer can be.

The binder resin may be a thermoplastic resin or a cured product of a curable resin. The high-refractive-index layer may have a hard film property. In this case, the high-refractive-index layer may be formed of a cured product of a hard coat-forming composition containing an active energy ray-curable resin such as an ultraviolet-curable resin and a refractive index-imparting agent. Active energy ray-curable resins include, for example, (meth)acrylic resins, silicone-based resins, polyester-based resins, urethane-based resins, amide-based resins, epoxy-based resins, etc., preferably UV-curable resins . The ultraviolet curable resin constituting the binder resin is preferably a (meth)acrylic resin, more preferably a (meth) Acrylic resin.

In addition, "(meth)acryl" in this specification means either acryl or methacryl. "(meth)" in (meth)acrylate etc. has the same meaning.

From the viewpoint of the refractive index of the high refractive index layer and from the viewpoint of making a little light leakage difficult to see, the thickness (optical film thickness) of the high refractive index layer is preferably from 10 nm to 1000 nm, more preferably from 10 nm to 500 nm , and more preferably 20nm to 300nm, even more preferably 40nm to 250nm, particularly preferably 100nm to 200nm.

The high refractive index layer has a refractive index at a wavelength of 550 nm of preferably 1.6 or higher, more preferably 1.62 or higher, from the viewpoint of making a small amount of light leakage difficult to recognize. From the viewpoint of making the reflection hue of the optical layered body moderately blue, the refractive index is preferably 1.75 or less, more preferably 1.70 or less.

The optical function layer (A) 1 is generally directly laminated on the surface of the linear polarizing plate 2 . For example, the composition for forming a high refractive index layer can be coated on the surface of the linear polarizer 2 and dried and/or cured as necessary to directly laminate the high refractive index layer on the surface of the linear polarizer 2 .

The optical functional layer (A) may include a base film and a high refractive index layer laminated thereon. In this case, the optical function layer (A) 1 may be laminated on the linear polarizer 2 via the first bonding layer 10 , for example, so that the base film side thereof faces the linear polarizer 2 . The composition for forming a high refractive index layer can be applied on the base film, and dried and/or cured as necessary to form an optical functional layer (A) including the base film and the high refractive index layer. Alternatively, a linear polarizing plate can be produced by laminating the above-mentioned base film on the viewing side of the linear polarizer 2 as a protective film of the linear polarizer 2, furthermore, an optical function layer other than the base film can also be formed by bonding (A) The layers of 1 and the linear polarizing plate were used to produce an optical laminate. In this case, the optical function layer (A) 1 has the layer which comprises the optical function layer (A) 1 other than a base film, and a base film.

The thermoplastic resin film mentioned later can be used for a base film. From the viewpoint of thinning, the thickness of the substrate film is usually 100 μm or less, preferably 80 μm or less, more preferably 60 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. μm or less, and generally 5 μm or more, preferably 10 μm or more.

Among them, the base film is preferably a cyclic polyolefin resin film, a cellulose ester resin film, a polyester resin film or a (meth)acrylic resin film.

The optical function layer (A) 1 may contain a thermoplastic resin film other than the said base film. For example, by laminating the thermoplastic resin film on the viewing side of the linear polarizer 2 as a protective film of the linear polarizer 2, a linear polarizing plate can be produced. Furthermore, an optical function layer other than the thermoplastic resin film can also be formed by bonding. (A) The layer of 1 and a linear polarizing plate were used to produce an optical laminate. In this case, the optical function layer (A) 1 may have There are layers and thermoplastic resin films constituting the optical function layer (A) 1 other than the thermoplastic resin film. Details about the thermoplastic resin film will be described later.

When the optical function layer (A) includes a high-refractive-index layer and a substrate film, the difference in refractive index at a wavelength of 550 nm is preferably from 0.05 to 0.30, more preferably from the viewpoint of making a little light leakage difficult to see. Preferably, it is not less than 0.08 and not more than 0.26, and more preferably not less than 0.10 and not more than 0.24.

When the optical functional layer (A) includes a high refractive index layer and a base film, a resin layer may be interposed between the high refractive index layer and the base film, and the resin layer may also be placed between the high refractive index layer and the base material opposite side of the membrane. An example of the resin layer is a hard coat layer. Moreover, the resin layer which may be interposed between a high-refractive-index layer and a base film may be a primer layer. About the hard-coat layer, the description mentioned later is used.

When the optical function layer (A) includes a base film and a resin layer, by laminating the base film and the resin layer on the viewing side of the linear polarizer 2 as a protective film and a hard coat layer of the linear polarizer 2 Furthermore, in producing a linear polarizing plate, an optical laminate can be produced by bonding layers constituting the optical function layer (A) 1 other than the base film and the resin layer and the linear polarizing plate together. In this case, the optical function layer (A) 1 has the layer which comprises the optical function layer (A) 1 other than this base film and this resin layer, a base film, and a resin layer.

When the above-mentioned resin layer is included, the difference in refractive index between the resin layer and the high-refractive index layer at a wavelength of 550 nm is preferably from 0.05 to 0.30, more preferably from 0.08, from the viewpoint of making a small amount of light leakage difficult to see. More than 0.26, more preferably 0.10 to 0.24.

The optical functional layer (A) 1 may include one or more high-refractive-index layers, pigment-containing layers (such as yellow pigment-containing layers), alternating layers of high-refractive-index layers and low-refractive-index layers, liquid crystal layers, fluorescent A light-emitting layer, or a layer other than the combination of these that can adjust the reflective properties (reflectivity Y, reflective hue) of the optical laminate. As such a layer, the resin layer mentioned above is mentioned, for example. The resin layer can be arranged between the high refractive index layer and the base film, or on the opposite side of the base film in the high refractive index layer. The resin layer can be an adhesive layer.

Other examples of the layer that can adjust the reflective properties of the optical laminate include: the front and rear layers described later that are arranged on the side of the high refractive index layer opposite to the base film via an adhesive layer (sixth bonding layer 80 described later). Panel 90. Another example of the layer capable of adjusting the reflective properties of the optical laminate includes thermoplastic resin films other than the above-mentioned base film.

The optical functional layer (A) 1 is preferably one with high electrical insulation, for example, a layer with a resistance value exceeding 1.0×10 ⁷ Ω/□ is preferred. Also, in order to improve electrical insulation, an optical functional layer without a network structure such as a metal mesh layer, that is, an optical functional layer that is uniform across the entire surface is preferable.

(2) Linear Polarizer

The linear polarizer 2 has a function of selectively transmitting linearly polarized light in a certain direction from non-polarized light such as natural light. Examples of the linear polarizer include a stretched film or a stretched layer on which a dichroic dye is adsorbed, a cured product of a polymerizable liquid crystal compound and a liquid crystal cured layer made of a dichroic dye, and the like. The optical function layer (A) 1 and the linear polarizer 2 can be laminated via the first bonding layer 10 .

A linear polarizer having a stretched film with a dichroic dye adsorbed generally can be obtained by uniaxially stretching a polyvinyl alcohol-based resin film, dyeing the polyvinyl alcohol-based resin film with a dichroic dye such as iodine, and making the dichroic It is produced by the step of absorbing the dichroic dye, the step of treating the polyvinyl alcohol-based resin film adsorbed with the dichroic dye with the boric acid aqueous solution, and the step of washing with the boric acid aqueous solution.

The thickness of the stretched film adsorbed with the dichroic pigment is generally less than 30 μm , preferably less than 18 μm , more preferably less than 15 μm . The thickness is generally 1 μm or more, for example, 5 μm or more.

The polyvinyl alcohol-based resin can be obtained by saponifying polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, other than polyvinyl acetate which is a homopolymer of vinyl acetate, for example, a copolymer of vinyl acetate and other monomers copolymerizable therewith can be used. Copolymerizable with vinyl acetate Other monomers include, for example, unsaturated carboxylic acid-based compounds, olefin-based compounds, vinyl ether-based compounds, unsaturated sulfone-based compounds, and (meth)acrylamide-based compounds having ammonium groups.

The degree of saponification of the polyvinyl alcohol-based resin is generally not less than 85 mol % and not more than 100 mol %, preferably not less than 98 mol %. The polyvinyl alcohol-based resin may be modified, and polyvinyl formaldehyde, polyvinyl acetal, etc. modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol-based resin is generally not less than 1,000 and not more than 10,000, preferably not less than 1,500 and not more than 5,000.

A linear polarizer having a stretched layer adsorbed with a dichroic pigment can generally be manufactured through the following steps: a step of coating a coating liquid containing the above-mentioned polyvinyl alcohol-based resin on the substrate layer; uniaxially stretching the obtained laminated film The step of dyeing the polyvinyl alcohol-based resin layer of the uniaxially stretched laminated film with a dichroic dye to adsorb the dichroic dye; treating the film adsorbed with the dichroic dye with an aqueous solution of boric acid step; and the step of washing with boric acid aqueous solution after treatment. The substrate layer can be used as a protective film of the linear polarizer, and can also be peeled off from the linear polarizer. The material and thickness of the base material layer may be the same as those of the thermoplastic resin film described later.

The optical laminate may include a protective film laminated on one or both sides of the stretched film on which the dichroic dye is adsorbed or the linear polarizer of the stretched layer. As the protective film, a thermoplastic resin film described later can be used. The linear polarizer and the protective film can be laminated through the bonding layer described later.

As mentioned above, the thermoplastic resin film (protective film) laminated|stacked on the viewing side of a linear polarizer can be included in an optical function layer (A). The thermoplastic resin film and the linear polarizer can be bonded via the first bonding layer.

Examples of the thermoplastic resin constituting the thermoplastic resin film include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether resins; polyethylene Resin; polycarbonate resin; polyamide resin such as nylon or aromatic polyamide; polyimide resin; polyethylene, polypropylene, ethylene. Polyolefin resins such as propylene copolymers; ring systems and rings having a norbornene structure Polyolefin resin (also known as norcamphene resin); (meth)acrylic resin; polyarylate resin; polystyrene resin; polyvinyl alcohol resin, etc. Among them, the thermoplastic resin film is preferably a cyclic polyolefin-based resin film, a cellulose ester-based resin film, a polyester-based resin film, or a (meth)acrylic resin film.

From the viewpoint of thinning, the thickness of the thermoplastic resin film is generally 100 μm or less, preferably 80 μm or less, more preferably 60 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less. μm or less, and usually 5 μm or more, preferably 10 μm or more.

A hard coat layer can be formed on a thermoplastic resin film. The hard coat layer may be formed on one side or both sides of the thermoplastic resin film. By providing a hard coat layer, it can be used as a thermoplastic resin film with improved hardness and scratch resistance.

The hard coat layer is, for example, a cured layer of an active energy ray curable resin, preferably an ultraviolet curable resin. Examples of ultraviolet curable resins include (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. In order to improve the strength, the hard coat layer may contain additives. The additive is not particularly limited, and examples thereof include inorganic fine particles, organic fine particles, or mixtures thereof.

The polymerizable liquid crystal compound used to form the linear polarizer belonging to the liquid crystal cured layer has a polymerizable reactive group and is a compound exhibiting liquid crystallinity. The polymerizable reactive group is a group that participates in a polymerization reaction, preferably a photopolymerizable reactive group. The photopolymerizable reactive group refers to a group that can participate in a polymerization reaction due to an active radical or an acid generated from a photopolymerization initiator. Examples of photopolymerizable reactive groups include vinyl, methacryloxy, 1-chlorovinyl, isopropenyl, 4-vinylphenyl, acryloxy, methacryloxy, oxirane Alkyl (oxiranyl group), oxetanyl group (oxetanyl group), etc. Among them, acryloxy, methacryloxy, methacryloxy, oxiranyl and oxetanyl are preferred, and acryloxy is more preferred. The type of polymerizable liquid crystal compound is not particularly limited, and rod-like liquid crystal compounds can be used. compounds, discotic liquid crystal compounds, and mixtures thereof. The liquid crystal property of the polymerizable liquid crystal compound may be thermotropic liquid crystal or lyotropic liquid crystal, and if the thermotropic liquid crystal is classified by degree of order, it may be nematic liquid crystal or smectic liquid crystal.

色素、花藍色素、萘色素、偶氮染料、及蒽醌色素等，其中，偶氮染料為較佳。偶氮染料可列舉單偶氮染料、雙偶氮染料、三偶氮染料、四偶氮染料、及二苯乙烯偶氮染料等，較佳為雙偶氮染料，及三偶氮染料。二色性色素可單獨，亦可組合2種以上，組合3種以上為較佳。尤其，組合3種以上之偶氮化合物為較佳。二色性色素之一部分可具有反應性基，或可具有液晶性。 In the cured liquid crystal layer, the dichroic pigment is dispersed and aligned in the cured product of the polymerizable liquid crystal compound. The dichroic dye used in the linear polarizer belonging to the liquid crystal cured layer preferably has a maximum absorption wavelength in the range of 300 nm to 700 nm. Such dichroic dyes can be, for example, acridine dyes,

Pigments, cyanines, naphthalene pigments, azo dyes, and anthraquinone dyes, among which azo dyes are preferred. Azo dyes include monoazo dyes, disazo dyes, trisazo dyes, tetrasazo dyes, and stilbene azo dyes, and are preferably disazo dyes and trisazo dyes. Dichroic dyes may be used alone or in combination of two or more, preferably three or more. Especially, it is preferable to combine 3 or more types of azo compounds. Part of the dichroic dye may have a reactive group, or may have liquid crystallinity.

The linear polarizer belonging to the liquid crystal cured layer can be coated with a composition for forming a linear polarizer containing a polymerizable liquid crystal compound and a dichroic dye on an alignment film formed on the substrate layer, and polymerizing the polymerizable liquid crystal compound. formed by hardening. The composition for forming a linear polarizer may be applied on the base layer to form a coating film, and the coating film may be stretched simultaneously with the base layer to form a linear polarizer. The base material layer used for forming a linear polarizer can be used as a protective film of a linear polarizer. The material and thickness of the base material layer may be the same as those of the aforementioned thermoplastic resin film.

A composition for forming a linear polarizer containing a polymerizable liquid crystal compound and a dichroic dye, and a method for producing a linear polarizer using the composition are exemplified in JP-A-2013-37353 and JP-A-2013-33249 Those described in the gazette, Japanese Patent Application Laid-Open No. 2017-83843, etc. In addition to the polymerizable liquid crystal compound and the dichroic dye, the composition for forming a linear polarizer may further contain a solvent Agents, polymerization initiators, crosslinking agents, leveling agents, antioxidants, plasticizers, sensitizers and other additives. These components may be used individually by 1 type, and may use it in combination of 2 or more types.

The polymerization initiator that may contain the composition for forming a linear polarizer is a compound that can initiate the polymerization reaction of a polymerizable liquid crystal compound. From the viewpoint that the polymerization reaction can be started at a lower temperature, a photopolymerizable initiator is preferable. . Specifically, photopolymerization initiators capable of generating active radicals or acids by the action of light are exemplified, and among them, photopolymerization initiators that generate radicals by the action of light are preferred. The content of the polymerization initiator is preferably from 1 to 10 parts by mass, more preferably from 3 to 8 parts by mass, relative to 100 parts by mass of the total amount of the polymerizable liquid crystal compound. Within this range, the reaction of the polymerizable group will sufficiently proceed, and the alignment state of the liquid crystal compound will be easily stabilized.

The thickness of the linear polarizer belonging to the liquid crystal hardening layer is generally not more than 10 μm , preferably not less than 0.5 μm and not more than 8 μm , more preferably not less than 1 μm and not more than 5 μm .

The optical layered body may include the aforementioned substrate layer on which the linear polarizer belonging to the cured liquid crystal layer is formed. The substrate layer may be the above-mentioned thermoplastic resin film contained in the optical function layer (A) or a protective film of a linear polarizer. Alternatively, the substrate layer may be peeled off from the linear polarizer. The optical layered body may have the above-mentioned alignment film, or may not have the above-mentioned alignment film.

For the purpose of protecting the linear polarizer, etc., the linear polarizer belonging to the liquid crystal cured layer may have an overcoat layer on one side or both sides. The overcoat layer can be formed, for example, by coating a composition for forming the overcoat layer on a linear polarizer. The material constituting the overcoat layer includes, for example, photocurable resins, water-soluble polymers, and the like. Specifically, (meth)acrylic resins, polyvinyl alcohol-based resins, and the like can be used.

The linear polarizer’s sensitivity correction polarization degree Py is generally above 95%, preferably above 97%, more preferably above 98%, even more preferably above 98.7%, even more preferably above 99.0%, especially preferably 99.4% or more, or 99.9% or more. The sensitivity correction polarization degree Py of the linear polarizer can also be 99.999% or less.

The degree of polarization Py can be corrected by using a spectrophotometer with an integrating sphere ("V7100" manufactured by JASCO Co., Ltd.) Calculated by correcting the sensitivity.

It is beneficial to improve the anti-reflection function of the optical laminate by increasing the sensitivity correction polarization degree Py of the linear polarizer. If the sensitivity correction polarization degree Py is less than 95%, the antireflection function may not be exhibited.

The sensitivity correction monomer transmittance Ty of the linear polarizer is generally above 41%, preferably above 41.1%, more preferably above 41.2%, may be above 42%, or above 42.5%. The sensitivity correction monomer transmittance Ty of the linear polarizer is generally below 50%, may also be below 48%, may also be below 46%, may also be below 44%, may also be below 43%. When the transmittance Ty of the single-body of the light sensitivity correction is too high, the light sensitivity correction polarization degree Py becomes too low, and the antireflection function of the optical layered body becomes insufficient.

The sensitivity correction single transmittance Ty can be obtained by using a spectrophotometer with an integrating sphere ("V7100" manufactured by JASCO Co., Ltd.) by comparing the 2-degree field of view (C light source) of "JIS Z 8701 The transmittance is calculated by correcting the sensitivity.

The linear polarizer is preferably in the range of -5 to 5 for the orthogonal hue a*, more preferably in the range of -3 to 3. Also, the orthogonal hue b* is preferably in the range of -10 to 10, more preferably in the range of -5 to 5, and more preferably in the range of -3 to 3. By using a spectrophotometer with an integrating sphere ("V7100" manufactured by JASCO Co., Ltd.), and using color functions such as C light source for the obtained transmittance, calculate L*a*b*(CIE) in the colorimetric system The chromaticities a* and b* of the linear polarizer can be obtained from the hue of the linear polarizer monomer (single hue), the hue of the linear polarizer arranged in parallel (parallel hue), and the hue of the linear polarizer arranged orthogonally (orthogonal hue). ).

(3) Phase difference layer

The optical layer system includes a retardation layer 3 having a first retardation layer 3a. The linear polarizer 2 and the first retardation layer 3 a can be laminated with the second bonding layer 20 interposed therebetween. When the protective film is laminated on the side opposite to the viewing side of the linear polarizer 2 , the protective film and the first retardation layer 3 a can be laminated via the second bonding layer 20 .

The retardation layer 3 may have only the first retardation layer 3a, or may have a laminated structure composed of two or more retardation layers. That is, the retardation layer 3 may include one or more retardation layers other than the first retardation layer 3a. The retardation layer 3 may have an overcoat layer protecting its surface, a base material layer supporting the retardation layer 3, and the like.

The first retardation layer 3a is, for example, a λ/4 layer. When the retardation layer 3 includes two retardation layers, the combination of the retardation layers of this layer can be enumerated in sequence from the side of the linear polarizer 2: the combination of the λ/4 layer and the positive C layer, the combination of the λ/2 layer and the The combination of λ/4 layer, the combination of positive C layer and λ/4 layer. A bonding layer (fifth bonding layer) to be described later can be used for lamination of retardation layers.

The in-plane retardation value Re(550) of the λ/4 layer at a wavelength of 550nm is generally in the range of 90nm to 220nm, preferably 100nm to 200nm. The in-plane retardation value Re(550) of the λ/2 layer at a wavelength of 550nm is preferably in the range of 100nm to 300nm, more preferably 150nm to 300nm, and more preferably 200nm to 300nm. In addition, the retardation value Rth(550) in the thickness direction of the positive C layer at a wavelength of 550nm is generally in the range of -170nm to -10nm, preferably -150nm to -20nm.

The retardation layer 3 has inverse wavelength dispersion, and the wavelength dispersion α is preferably not less than 0.80 and not more than 0.88. Thereby, the above-mentioned internal reflection can be suppressed effectively.

The wavelength dispersion α refers to the ratio of the in-plane retardation value Re(450) at a wavelength of 450 nm to the in-plane retardation value Re(550) at a wavelength of 550 nm.

Wavelength dispersion α = in-plane retardation value Re(450)/in-plane retardation value Re(550)

The first retardation layer 3 a and other retardation layers may be retardation films formed by stretching the above-mentioned thermoplastic resin film, or may be liquid crystal cured layers. The cured liquid crystal layer is a cured product layer in which a polymerizable liquid crystal compound is polymerized and cured in an aligned state. The retardation layer 3 may include one or more liquid crystal cured layers, or may include two or more layers.

The polymerizable liquid crystal compound may be, for example, a rod-shaped polymerizable liquid crystal compound or a discotic polymerizable liquid crystal compound, either of which may be used, or a mixture containing both of them may be used. When the rod-shaped polymerizable liquid crystal compound is aligned horizontally or vertically with respect to the substrate layer, the optical axis of the polymerizable liquid crystal compound is aligned with the long axis direction of the polymerizable liquid crystal compound. When the discotic polymerizable liquid crystal compound is aligned, the optical axis of the polymerizable liquid crystal compound exists in a direction perpendicular to the disc surface of the polymerizable liquid crystal compound.

In order for the cured liquid crystal layer formed by polymerizing the polymerizable liquid crystal compound to exhibit an in-plane retardation, the polymerizable liquid crystal compound may be aligned in an appropriate direction. When the polymerizable liquid crystal compound is rod-shaped, an in-plane phase difference is exhibited by aligning the optical axis of the polymerizable liquid crystal compound horizontally with respect to the plane of the substrate layer. In this case, the direction of the optical axis and the direction of the slow axis unanimous. In the case where the polymerizable liquid crystal compound is discoid, an in-plane retardation is exhibited by aligning the optical axis of the polymerizable liquid crystal compound horizontally with respect to the plane of the substrate layer, and in this case, the optical axis is perpendicular to the slow axis . The alignment state of the polymerizable liquid crystal compound can be adjusted through the combination of the alignment layer and the polymerizable liquid crystal compound.

The polymerizable liquid crystal compound is a compound having at least one polymerizable reactive group and liquid crystallinity. When using two or more types of polymerizable liquid crystal compounds in combination, it is preferable that at least one type has two or more polymerizable reactive groups in the molecule. The polymerizable reactive group is a group participating in a polymerization reaction, preferably a photopolymerizable reactive group. The photopolymerizable reactive group is caused by active radicals or acids generated from the photopolymerization initiator. Form the base that can participate in the polymerization reaction. Examples of photopolymerizable reactive groups are the same as those described above. The liquid crystal of the polymerizable liquid crystal compound can be thermotropic liquid crystal or lyotropic liquid crystal. If the thermotropic liquid crystal is classified according to the degree of order, it can be nematic liquid crystal or smectic liquid crystal.

The optical layered body may include an alignment layer adjacent to the retardation layer. The alignment layer has an alignment regulating force for aligning the polymerizable liquid crystal compound in a desired direction. The alignment layer can be a vertical alignment layer that aligns the molecular axis of the polymerizable liquid crystal compound vertically with respect to the substrate layer, or a horizontal alignment layer that aligns the molecular axis of the polymerizable liquid crystal compound horizontally with respect to the substrate layer, or it can be An oblique alignment layer that obliquely aligns the molecular axes of the polymerizable liquid crystal compound with respect to the substrate layer.

The thickness of the liquid crystal cured layer may be more than 0.1 μm , may be more than 0.5 μm , may be more than 1 μm , may be more than 2 μm , and is preferably less than 10 μm , and may also be 8 μm. μm or less, may be 5 μm or less.

The cured liquid crystal layer can be formed by applying a composition for forming a liquid crystal layer containing a polymerizable liquid crystal compound on the substrate layer, drying it, and polymerizing the polymerizable liquid crystal compound. The composition for forming a liquid crystal layer can also be applied on the alignment layer formed on the base material layer. The material and thickness of the substrate layer may be the same as those of the aforementioned thermoplastic resin film. The substrate layer can be included in the optical laminate along with the retardation layer as the liquid crystal hardening layer, or the substrate layer can be peeled off, and only the liquid crystal hardening layer, or the liquid crystal hardening layer and the alignment layer can be included in the optical laminate.

(4) Adhesive layer

Fig. 2 is a schematic cross-sectional view of another example of the optical laminate according to the present invention. The optical laminate system shown in FIG. 2 includes an optical functional layer (A) 1, a first bonding layer 10, a linear polarizer 2, a second bonding layer 20, a retardation layer 3 having reverse wavelength dispersion, and an adhesive layer 50. The adhesive layer 50 can be laminated on the optical layered body The surface opposite to the viewing side (optical function layer (A) 1 side) can be used for lamination of an optical layered body to image display elements such as organic electroluminescent display elements.

In the optical laminate shown in FIG. 2 , the optical function layer (A) 1 includes a high refractive index layer 1a, a base film 1b, a third bonding layer 30, and a thermoplastic resin film 11 in this order from the viewing side. The protective film 12 is laminated on the side opposite to the viewing side of the linear polarizer 2 via the fourth bonding layer 40 . The third bonding layer 30 and the thermoplastic resin film 11 can be omitted. The fourth bonding layer 40 and the protective film 12 may also be omitted.

In the optical layered body shown in FIG. 2 , the retardation layer 3 includes a first retardation layer 3 a and a second retardation layer 3 b. The 1st retardation layer 3a and the 2nd retardation layer 3b are bonded by the 5th bonding layer 3c. However, the fifth bonding layer 3c and the second retardation layer 3b may be omitted.

The thickness of the adhesive layer 50 may be, for example, 250 μm or less, preferably 100 μm or less, more preferably 50 μm or less, and more preferably 40 μm or less from the viewpoint of thinning. From the viewpoint of durability, the lower limit of the thickness of the adhesive layer may be, for example, 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more.

The adhesive layer 50 may be composed of an adhesive composition mainly composed of (meth)acrylic resin, rubber resin, urethane resin, ester resin, silicone resin, and polyvinyl ether resin. Among them, a (meth)acrylic resin excellent in transparency, weather resistance, heat resistance, etc. is suitable as the adhesive composition of the matrix polymer. The adhesive composition may be an active energy ray curing type or a thermosetting type.

The (meth)acrylic resin (matrix polymer) used in the adhesive composition is suitable to use butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, (meth) ) Polymers or copolymers in which one or more (meth)acrylates such as 2-ethylhexyl acrylate are monomers. Among the matrix polymers, those in which polar monomers are copolymerized are preferred. Examples of polar monomers include (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, (meth)acrylic acid N,N-di A monomer having a carboxyl group, a hydroxyl group, an amido group, an amino group, an epoxy group, etc., such as methylaminoethyl ester and glycidyl (meth)acrylate.

The adhesive composition may only contain the above-mentioned matrix polymer, but generally further contains a crosslinking agent. Cross-linking agent can enumerate: the metal ion of more than 2 valences, the metal ion that forms carboxylate metal salt with carboxyl group; The polyamine that forms amide bond with carboxyl group; The polyamine that forms ester bond with carboxyl group Epoxy compounds or polyalcohols; polyisocyanate compounds that form amide bonds with carboxyl groups. Among them, polyisocyanate compounds are preferred.

系化合物、鎳錯鹽系化合物等。 The adhesive layer 50 may contain a light selective absorber. The photoselective absorber has a maximum absorption wavelength in, for example, a wavelength band of 390 to 430 nm, which is a short wavelength band of visible light. Here, "visible light" in this embodiment means the light of the wavelength contained in the range of 390nm - 830nm. Such light selective absorbers include salicylate-based compounds, benzophenone-based compounds, benzotriazole-based compounds, cyanoacrylate-based compounds,

series compounds, nickel zirconium salt series compounds, etc.

In addition, a compound having a maximum absorption wavelength in the wavelength range of 390 to 430 nm can be synthesized by a known method and used as a photoselective absorber. As such a dye, for example, known compounds described in JP-A-2017-120430 as light selective absorption compounds can be used.

The adhesive layer 50 may be an adhesive layer satisfying the following formula (1).

A(410)≧0.1 (1)

[In the formula (1), A(410) represents the absorbance at a wavelength of 410 nm. ]

A larger value of A(410) indicates higher light absorption at a wavelength of 410 nm. If the value of A(410) is less than 0.1, the light absorption at the wavelength of 410nm is low, and the deterioration of the phase difference layer of the organic electroluminescent display element and the liquid crystal hardened layer tends to occur by light around 400nm. The value of A(410) is preferably at least 0.3, more preferably at least 0.8, and most preferably at least 1.0. There is no particular upper limit, and it is generally 10 or less.

When the above-mentioned adhesive layer 50 contains a light-selective absorbing agent and has light-selective absorbing properties, since the reflection hue is close to black display (the reflection hue of the circular polarizing plate becomes neutral), a little light leakage becomes easy to be recognized. Therefore, it is also advantageous that the optical layered body of the present invention, which has an optical function layer (A), can make a small amount of light leakage difficult to see, includes a layer having light selective absorption performance. In addition, not only the adhesive layer but also light absorbing properties can be provided in the resin layer, hard coat layer, bonding layer, and the like. The light selective absorber mentioned above may include a resin layer, a hard coat layer, an adhesive layer, and the like.

The active energy ray-curable adhesive composition has the property of being hardened by the irradiation of active energy rays such as ultraviolet rays or electron beams. The property of adjusting the adhesive force can be adjusted by hardening by irradiation of active energy rays. The composition of the active energy ray-curable adhesive is preferably an ultraviolet-curable adhesive. The active energy ray-curable adhesive composition system further contains an active energy ray polymerizable compound in addition to a matrix polymer and a crosslinking agent. A photopolymerization initiator, a photosensitizer, etc. may also be contained as needed.

(5) Separation membrane

As shown in FIG. 3 , the optical layered body may include a separation film 60 for protecting the outer surface of the adhesive layer 50 (the surface on the opposite side to the second retardation layer 3b). The optical layered body shown in FIG. 3 has the same layer configuration as the optical layered body shown in FIG. 2 except for the separation film 60 . The separation film 60 is generally composed of a thermoplastic resin film that has been subjected to release treatment with a silicone-based, fluorine-based, or other release agent on one side, and the release-treated surface is bonded to the adhesive layer 50 .

The thermoplastic resin constituting the separation membrane 60 includes, for example, polyethylene-based resins such as polyethylene, polypropylene-based resins such as polypropylene, and polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate. The thickness of the separation membrane 60 is, for example, not less than 10 μm and not more than 50 μm .

(6) Protective film

As shown in FIG. 4 , the optical layered body may include a pellicle film 70 laminated on the surface of the optical function layer (A) 1 side. The optical layered body shown in FIG. 4 has the same layer configuration as that of the optical layered body shown in FIG. 3 except for the pellicle 70 . The protective film 70 is composed of, for example, a base film and an adhesive layer laminated thereon. Regarding the adhesive layer, the above-mentioned description is cited. The resin constituting the base film may be, for example, a polyethylene-based resin such as polyethylene, a polypropylene-based resin such as polypropylene, or a polyester-based resin such as polyethylene terephthalate or polyethylene naphthalate. , polycarbonate resin and other thermoplastic resins. Polyester-based resins such as polyethylene terephthalate are preferable.

(7) Front panel

As shown in FIG. 5 , the optical function layer (A) 1 may further include a front panel 90 . The front panel 90 is generally disposed on the outermost surface on the viewing side of the optical laminate. The front panel 90 can be laminated, for example, on the surface of the high refractive index layer 1 a on the viewing side via the sixth bonding layer 80 . In this case, the optical function layer (A) 1 includes the sixth bonding layer 80 and the front panel 90 . The optical layered body shown in FIG. 5 has the same layer configuration as that of the optical layered body shown in FIG. 3 except for the sixth bonding layer 80 and the front plate 90 .

As long as the front panel 90 is a light-permeable plate, the material and thickness are not limited. The front panel 90 may consist of only one layer, or may consist of two or more layers. The front panel 90 may be a plate-shaped body made of resin (such as a resin plate, a resin sheet, or a resin film), a plate-shaped body made of glass (such as a glass plate, a glass film, etc.), a plate-shaped body made of resin, or a glass-made body. Laminates of plate-like bodies. The front panel may constitute the outermost surface of the display device.

The thickness of the front panel 90 is, for example, 1000 μm or less, preferably 800 μm or less. The thickness is generally more than 10 μm , preferably more than 20 μm .

The resin constituting the plate-shaped body made of resin may, for example, be triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, acryl cellulose, butyryl cellulose, acetyl propyl cellulose, or acetyl cellulose. Acyl cellulose, polyester, polystyrene, polyamide, polyetherimide, poly(meth)acrylic acid, polyimide, polyether, polystyrene, polyethylene, polypropylene, polymethyl Pentene, polyvinyl chloride, polyvinylidene chloride, Polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether ketone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polynaphthalene Thermoplastic resins such as ethylene glycol formate, polycarbonate, and polyamideimide. These thermoplastic resins can be used individually or in mixture of 2 or more types. From the standpoint of strength and transparency, the resin-made plate-like body is preferably a thermoplastic resin film formed of polyimide, polyamide, polyamide-imide, or the like.

From the viewpoint of hardness, the front panel 90 may be a thermoplastic resin film provided with a hard coat layer. The hard coat layer may be formed on one side or both sides of the thermoplastic resin film. By providing a hard coating, the hardness and scratch resistance can be improved. For the hard coat layer, the above-mentioned description of the hard coat layer that can be formed on the thermoplastic resin film is cited.

When the front panel 90 is a glass plate, the glass plate is preferably tempered glass for displays. The thickness of the glass plate may be, for example, not less than 10 μm and not more than 1000 μm , or may be not less than 10 μm and not more than 800 μm . By using a glass plate, the front panel which has excellent mechanical strength and surface hardness can be comprised.

The front panel 90 is preferably highly rigid, for example, the Young's modulus is 70 GPa or more, or 80 GPa or more. The Young's modulus of the front panel 90 is generally 100 GPa or less. Young's modulus can be measured as follows. A measurement sample of the front panel 90 having a long side of 110 mm×short side of 10 mm was cut out using a super cutter. Next, the upper and lower grippers of a tensile testing machine (manufactured by Shimadzu Corporation, Autograph AG-Xplus testing machine) were clamped at both ends of the longitudinal direction of the above-mentioned measurement sample at a distance of 5 cm between the grippers, In an environment with a temperature of 23°C and a relative humidity of 55%, stretch the sample for measurement in the longer direction at a pulling speed of 4 mm/min. From the gradient of the straight line between 20 and 40 MPa in the stress-strain curve obtained, it can be obtained Calculate the Young's modulus at a temperature of 23°C and a relative humidity of 55%.

When the optical function layer (A) 1 includes the front panel 90 laminated on the viewing side surface of the high refractive index layer 1a through the sixth bonding layer 80, the sixth bonding layer is required from the viewpoint of making a little light leakage difficult to recognize. Composite The refractive index of 80 at a wavelength of 550 nm is preferably 1.45 to 1.51, more preferably 1.46 to 1.50, and the refractive index of the front panel 90 at a wavelength of 550 nm is preferably 1.49 to 1.52, more preferably 1.50 to 1.52 . The sixth bonding layer 80 is preferably an adhesive layer.

When the optical laminate is applied to an image display device, the front panel 90 not only has the function of protecting the front (screen) of the image display device (function as a window film), but also has the function of a touch sensor, blue light Cut-off function, viewing angle adjustment function, etc.

(8) Bonding layer

The optical laminate may include an adhesive layer for bonding two layers (or films). Examples of the bonding layer include the first bonding layer 10 bonding the optical function layer (A) 1 and the linear polarizer 2 , the second bonding layer bonding the linear polarizing film 2 (or protective film 12 ) and the retardation layer 3 20. The third bonding layer 30 for bonding the base film 1b and the thermoplastic resin film 11, the fourth bonding layer 40 for bonding the linear polarizer 2 and the protective film 12, bonding the first retardation layer 3a and the second The fifth bonding layer 3c of the retardation layer 3b, the sixth bonding layer 80 for bonding the front panel 90, and the like.

The bonding layer is an adhesive layer made of an adhesive composition or an adhesive layer made of an adhesive composition. Regarding the adhesive composition and the adhesive layer, the description in (4) above is cited.

Examples of the adhesive composition include water-based adhesives, active energy ray-curable adhesives, and the like. Examples of the water-based adhesive include polyvinyl alcohol-based resin aqueous solutions, water-based two-component urethane-based emulsified adhesives, and the like. Active energy ray-curable adhesives are adhesives that are cured by irradiating active energy rays such as ultraviolet rays, and examples include adhesives containing polymerizable compounds and photopolymerizable initiators, adhesives containing photoreactive resins, adhesives containing And photoreactive cross-linking agent adhesive, etc. The aforementioned polymerizable compounds include photopolymerizable monomers such as photocurable epoxy monomers, photocurable (meth)acrylic monomers, photocurable urethane monomers, and oligomers derived from these monomers. body etc. The above-mentioned photopolymerization initiator can include irradiation Compounds of substances that generate active species such as neutral free radicals, anion free radicals, and cationic free radicals by active energy rays such as ultraviolet rays.

The thickness of the adhesive layer formed by the adhesive composition can be, for example, 0.1 μm or more, preferably 0.5 μm or more, 1 μm or more, or 2 μm or more, and can also be 100 μm or less, 50 μm m or less, 25 μm or less, 15 μm or less or 5 μm or less.

Surface activation treatments such as corona treatment, plasma treatment, and flame treatment can be performed on the two facing surfaces bonded via the bonding layer.

<Image display device>

An image display device according to the present invention includes the optical layered body and an image display element (organic electroluminescent display element, etc.) according to the present invention. The optical laminate is disposed on the viewing side of the image display element. The adhesive layer 50 can be used to bond the optical laminate to the image display element.

Fig. 6 is a schematic cross-sectional view showing an example of an image display device according to the present invention. In FIG. 6 , the optical layered body shown in FIG. 5 is used as an example of the optical layered body. The optical laminate system is attached to the image display element 100 by using the adhesive layer 50 . On the surface (the outermost surface on the viewing side) of the optical layered body opposite to the adhesive layer 50 , the front plate 90 is laminated via the sixth bonding layer 80 .

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

Image display devices can be used as mobile devices such as smartphones and tablets, TVs, digital photo frames, electronic signage, measuring instruments and counters, office equipment, medical equipment, computer equipment, etc.

[Example]

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to these examples.

[determination]

(1) Reflectivity of optical functional layer

The reflectance R(450) and reflectance R(550) of the optical function layer were measured using "Cm2600d" by KONICA MINOLTA. During the measurement, a black acrylic plate ("Kanase Lite 1410" manufactured by Kanase Co., Ltd.) was bonded to the surface of the optical function layer on the opposite side to the surface that makes light incident through the adhesive layer.

(2) Refractive index and optical film thickness

The refractive index of the film and layer at a wavelength of 550 nm was measured as follows. The reflectance in the visible light region was measured using a spectrophotometer "MPC-2200" manufactured by Shimadzu Corporation. At the time of measurement, a black acrylic plate ("Kanase Lite 1410" manufactured by Kanase Co., Ltd.) was bonded to the back side of the measurement surface through an adhesive layer. Regarding the obtained reflectance spectrum, the spectral characteristics calculated from the calculation formula of the thin film interference spectrum, in particular, combined the reflectance at a wavelength of 550 nm and carried out spectral fitting to calculate the refractive index and optical film thickness at a wavelength of 550 nm. However, regarding the laminate B-1, the refractive index and optical film thickness of the high refractive index layer at a wavelength of 550 nm were measured by the following method.

(3) Phase difference properties of the phase difference layer

The retardation property of the retardation layer was measured using "KOBRA-WPR" of Oji Scientific Instruments Co., Ltd.

Hereinafter, in the present examples and comparative examples, the optical functional layers in the optical laminates obtained from laminates A-1 to A-5, B-1, and B-2 are referred to as optical functional layers A-1' to A, respectively. -5', B-1' and B-2'.

<Manufacturing Example 1: Fabrication of Optical Functional Layer>

(1) Preparation of composition for high refractive index layer formation

The composition systems for forming a high refractive index layer in each of the following examples were prepared in the following steps.

A photopolymerization initiator ("Irgacure 184" manufactured by BASF Corporation) and a dilution solvent (methyl ethyl ketone/propylene glycol monomethyl ether acetate mass ratio=5/1) were mixed and stirred. Here, an ultraviolet curable resin ("KAYARAD-DPHA" manufactured by Nippon Kayaku Co., Ltd.) was added and stirred. Furthermore, a zirconia particle dispersion ("ZRMIBK15WT%-P03" manufactured by CIK NanoTek Corporation, solid content 15% by mass, average primary particle diameter 7.8nm) was added and stirred to prepare a composition for forming a high refractive index layer.

(2) Fabrication of laminates A-1 to A-5

On a triacetyl cellulose film with a thickness of 40 μm (refractive index at a wavelength of 550 nm: 1.49. Hereinafter also referred to as “TAC film”) as a base film, the composition for forming a high refractive index layer was coated using a bar coater , dried, and irradiated with ultraviolet rays to prepare a laminate A-1 composed of a base film and a high refractive index layer having an optical film thickness shown in Table 1. Similarly, on the TAC film, each composition for forming a high refractive index layer was coated, dried, and irradiated with ultraviolet rays to produce laminates A-2 to A-5. Table 1 shows the refractive index and optical film thickness of the high refractive index layer at a wavelength of 550 nm.

(3) Fabrication of optical functional layers A-1' to A-5'

On the surface of the laminate A-1 opposite to the high refractive index layer (that is, the surface on the substrate film side), a hard coat is bonded via an adhesive layer (refractive index of 1.47 at a wavelength of 550nm). Layered cyclic polyolefin-based resin film (HC-COP) [in-plane retardation value Re at a wavelength of 590 nm: 100 nm, thickness of HC layer: 3 μm ]. Furthermore, an adhesive layer (refractive index 1.47 in wavelength 550nm, haze 0.2%) was laminated|stacked on the high refractive index layer of laminated body A-1. Attach an alkali-free glass plate (refractive index 1.51 at a wavelength of 550nm) to the adhesive layer to obtain an optical glass plate/adhesive layer/high refractive index layer/substrate film/adhesive layer/HC-COP Functional layer A-1'.

An optical function layer A-2' was obtained in the same manner as above except that the laminate A-2 was used.

An optical function layer A-3' was obtained in the same manner as above except that the laminate A-3 was used.

An optical functional layer A-4' was obtained in the same manner as above except that the laminate A-4 was used.

An optical function layer A-5' was obtained in the same manner as above except that the laminate A-5 was used.

(4) Fabrication of optical functional layers A-2” to A-5”

A hard coat ( HC) layer cyclic polyolefin-based resin film (HC-COP), to obtain an optical function layer A-2" composed of high refractive index layer/substrate film/adhesive layer/HC-COP.

An optical function layer A-3" was obtained in the same manner as above except that the laminate A-3 was used.

An optical function layer A-4" was obtained in the same manner as above except that the laminate A-4 was used.

An optical function layer A-5" was obtained in the same manner as above except that the laminate A-5 was used.

(5) Production of optical functional layer B-1"

As laminate B, "Technolloy C000" (polycarbonate resin film, overall thickness: 75 μm ) manufactured by SUMIKA ACRYL Co., Ltd. (a single-layer film, but conveniently referred to as laminate B-1) was used. -1. Table 1 shows the refractive index and optical film thickness of the laminate B-1 at a wavelength of 550 nm. The optical film thickness was measured using a contact thickness gauge. The refractive index is measured according to JIS K7142.

A cyclic polyolefin-based resin film (HC-COP) with a hard coat was bonded to one side of the laminate B-1 via an adhesive layer (refractive index of 1.47 at a wavelength of 550 nm), to obtain a laminate B -1/adhesive layer/optical functional layer B-1" composed of HC-COP.

(6) Production of optical functional layer B-2"

On a TAC film (refractive index of 1.49 at a wavelength of 550nm) with a thickness of 40 μm as a base film, a composition for forming a high refractive index layer was coated using a bar coater, dried and irradiated with ultraviolet rays to produce a base film and a laminate B-2 composed of a high refractive index layer having an optical film thickness shown in Table 1. Table 1 shows the refractive index and optical film thickness of the high refractive index layer at a wavelength of 550 nm.

A cyclic polyolefin-based resin film (HC-COP) with a hard coat layer was bonded to one side of the laminate B-2 via an adhesive layer (refractive index of 1.47 at a wavelength of 550 nm) to obtain a laminate B. -2/adhesive layer/optical functional layer B-2" made of HC-COP.

[Table 1]

The reflectance R(450), reflectance R(550) and reflectance R(630) of each optical functional layer, and the reflectance ratio (reflectance R(450)/reflectance R(550)) are shown in Table 2 .

[Table 2]

<Manufacturing Example 2: Fabrication of Linear Polarizing Plate>

(1) Production of linear polarizer

A polyvinyl alcohol-based resin film with a thickness of 20 μm (average degree of polymerization about 2400, degree of saponification over 99.9 mol%) is longitudinally uniaxially stretched about 5 times by dry stretching. After immersing in pure water at ℃ for 1 minute, immerse in an aqueous solution at a temperature of 28 ℃ with a mass ratio of iodine/potassium iodide/water of 0.05/5/100 for 60 seconds. Thereafter, the mass ratio of potassium iodide/boric acid/water was immersed in an aqueous solution at a temperature of 72° C. for 300 seconds. Then, after washing with pure water at a temperature of 26° C. for 20 seconds, drying was performed at a temperature of 65° C. to obtain a linear polarizer having iodine adsorbed and oriented on the polyvinyl alcohol-based resin film and having a thickness of 8 μm . The sensitivity-corrected monomer transmittance Ty of the obtained linear polarizer was 42.5%, the sensitivity-corrected polarization degree Py was 99.99%, the orthogonal hue a* was 0.1, and the orthogonal hue b* was -0.3.

(2) Preparation of water-based adhesive

A polyvinyl alcohol aqueous solution was prepared by dissolving 3 parts by mass of carboxy-modified polyvinyl alcohol ["KL-318" manufactured by Kuraray Co., Ltd.] with respect to 100 parts by mass of water. A water-soluble polyamide epoxy resin ("Sumirez Resin 650 (30)" manufactured by Taoka Chemical Industry Co., Ltd., solid content concentration: 30% by mass) was mixed in a ratio of 1.5 parts by mass with respect to 100 parts by mass of water. , to obtain a water-based adhesive.

(3) Production of linear polarizer

On one side of the linear polarizer obtained above, apply the above obtained water-based adhesive, laminate a cyclic polyolefin resin film (HC-COP) with a hard coat (HC) layer, and coat the above-mentioned The obtained water-based adhesive was laminated with a TAC film, and dried at a temperature of 80° C. for 5 minutes to obtain a linear polarizing plate with protective films on both sides of the linear polarizing plate. The layer structure of the linear polarizer is HC-COP/water-based adhesive layer/linear polarizer/water-based adhesive layer/TAC film. On the HC layer of the linear polarizing plate, a protective film with an adhesive layer on the base film is laminated to obtain a linear polarizing plate with protective film (hereinafter also referred to as “linear polarizing plate with PF”).

In addition, in this linear polarizing plate, the reflectance of the water-based adhesive layer was not measured as a meaningful value.

<Manufacturing Example 3: Fabrication of Retardation Laminate>

(1) Production of the first retardation layer

An alignment layer is formed on a first substrate layer made of a transparent resin, and a composition for forming a first retardation layer containing a rod-shaped nematic polymerizable liquid crystal compound is applied to produce a first substrate layer with a first substrate layer. 1 phase difference layer. The first retardation layer is a λ/4 layer. The thickness of the first retardation layer was 2 μm . The wavelength dispersion α of the first retardation layer [in-plane retardation value Re(450)/in-plane retardation value Re(550)] was 0.85, and Re(550) was 142nm (the average value of 12 places in the plane).

Moreover, about the 1st retardation layer, 140 mm x 70 mm was cut out, and the measurement of the in-plane retardation value of the 1st retardation layer at 12 places in the plane was implemented. Measure and calculate the distance of the in-plane phase difference Re(550) After the degree of dispersion, the maximum is 143nm and the minimum is 141nm. The difference between the maximum and minimum is 2nm. The details of the fabrication of the first retardation layer are shown below.

[Preparation of Alignment Layer Forming Composition (X)]

The photo-alignment material (weight average molecular weight: 50,000, m:n=50:50) with the following structure was manufactured according to the method described in Japanese Patent Laid-Open No. 2021-196514. Composition (X) for forming an alignment layer was prepared by mixing 2 parts by mass of a photoalignment material and 98 parts by mass of cyclopentanone (solvent) as components, and stirring the obtained mixture at 80° C. for 1 hour.

Photoalignment material:

[Manufacture of nematic polymerizable liquid crystal compounds]

A polymerizable liquid crystal compound (A1) and a polymerizable liquid crystal compound (A2) having structures shown below were prepared respectively. The polymerizable liquid crystal compound (A1) was prepared in the same manner as the method described in JP 2019-003177. The polymerizable liquid crystal compound (A2) was prepared in the same manner as the method described in JP-A-2009-173893.

Polymeric liquid crystal compound (A1):

Polymeric liquid crystal compound (A2):

A solution was obtained by dissolving 1 mg of the polymerizable liquid crystal compound (A1) in 10 mL of chloroform. The obtained solution was put into a measurement sample in a measurement cell with an optical path length of 1 cm, and the measurement sample was set in an ultraviolet-visible spectrophotometer (manufactured by Shimadzu Corporation "UV-2450") to measure the absorption spectrum. After reading the wavelength of maximum absorption from the obtained absorption spectrum, the maximum absorption wavelength λmax in the wavelength range of 300 to 400 nm was 356 nm.

[Modulation of the first retardation layer-forming composition (Y)]

The polymerizable liquid crystal compound (A1) and the polymerizable liquid crystal compound (A2) were mixed at a mass ratio of 93:7 to obtain a mixture. 0.1 parts by mass of a leveling agent "BYK-361N" (manufactured by BM Chemie Co., Ltd.) and 3 parts by mass of "IrgacureOXE-03" (manufactured by BASF JAPAN Co., Ltd.) as a photopolymerization initiator were added to 100 parts by mass of the obtained mixture . Furthermore, N-methyl-2-pyrrolidone (NMP) was added so that the solid content concentration might become 13 mass %. By stirring this mixture at a temperature of 80°C for 1 hour, a first composition (Y) for retardation layer formation was prepared.

[Production of the first retardation layer]

On a biaxially stretched polyethylene terephthalate (PET) film (manufactured by Diafoil Mitsubishi Plastics Co., Ltd.) as the first base material layer, the composition (X) for forming an alignment layer was coated with a bar coater. make the resulting coating film After drying at 120° C. for 2 minutes, it was cooled to room temperature to form a dry film. Thereafter, 100 mJ of polarized ultraviolet light (based on 313 nm) was irradiated with a UV irradiation device (SPOT CURE SP-9; manufactured by USHIO INC.) to obtain an alignment layer. The film thickness of the alignment layer measured using an ellipsometer M-220 manufactured by JASCO Corporation was 100 nm.

On the obtained alignment layer, the said 1st composition (Y) for retardation layer formation was apply|coated with the bar coater, and the coating film was formed. This coating film was heated and dried at 120° C. for 2 minutes, and then cooled to room temperature to obtain a dry coating film. Next, using a high-pressure mercury lamp ("UniQureVB-15201BY-A" manufactured by USHIO INC.), by irradiating the above-mentioned dry film with ultraviolet light with an exposure amount of 500mJ/cm ² (based on 365nm) in a nitrogen atmosphere, the polymerizable liquid crystal compound Form the hardened first retardation layer in the state of alignment in the horizontal direction in the plane of the substrate, and obtain a first substrate layer/alignment layer/first retardation layer (horizontally aligned liquid crystal cured film) with a first The first retardation layer of the base layer. The film thickness of the first retardation layer measured using a laser microscope LEXT OLS4100 manufactured by Olympus Co., Ltd. was 2.0 μm .

(2) Fabrication of the second retardation layer

The second phase difference layer with the second base material layer was produced by the following method.

[Preparation of the second retardation layer-forming composition (Y2)]

Mix 100 parts by mass of a polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan Co., Ltd.), 0.1 parts by mass of a leveling agent "BYK-361N" (manufactured by BYK-Chemie Co., Ltd.), and a photopolymerization initiator "Omnirad907" (manufactured by IGM Resin B.V. ) 2.5 parts by mass. Furthermore, 400 mass parts of propylene glycol monomethyl ether acetate (PGME) was added, and the obtained mixture was stirred at 80 degreeC for 1 hour, and the 2nd composition (Y2) for retardation layer formation was prepared.

Polymeric liquid crystal compound LC242:

[Preparation of Alignment Layer Forming Composition (X2)]

2-Butoxyethanol was added to Sunever-SE-610 (manufactured by Nissan Chemical Industries, Ltd.), which is a commercially available alignment polymer, so that the solid content was 1% by mass, to obtain an alignment layer forming composition (X2).

[Production of the second retardation layer]

As the second substrate layer, cycloolefin polymer (COP) (manufactured by Zeon Corporation, ZF14) was used, one side thereof was subjected to corona treatment using a corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.), and The surface was coated with an alignment layer forming composition (X2) using a bar coater, and dried at 90° C. for 1 minute. When the film thickness of the obtained alignment layer was measured with a laser microscope, it was 30 nm. Next, the second retardation layer-forming composition (Y2) was coated on the alignment layer using a bar coater, dried at 90° C. for 1 minute, and then, using a high-pressure mercury lamp (Ushio Inc. “UniQureVB-15201BY-A”), The second retardation layer with the second base layer was obtained by irradiating the dry film with ultraviolet light with an exposure amount of 1000 mJ/cm ² (based on 365 nm) in a nitrogen atmosphere. The film thickness of the second retardation layer was 450 nm when the film thickness was measured with a laser microscope. The in-plane retardation value was measured using KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd. As a result, Re(550)=1nm and Rth(550)=-75nm. Therefore, the second retardation layer with the second base layer has optical properties represented by nx≒ny<nz. In addition, since the retardation value of the COP at a wavelength of 550 nm is slightly 0, the optical properties are not affected.

(3) Preparation of UV curable adhesive

Mix the cation-curable components shown below to prepare a UV-curable adhesive.

3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Corporation): 70 parts by mass

Neopentyl glycol diglycidyl ether (trade name: EX-211, manufactured by Nagase ChemteX Corporation): 20 parts by mass

2-Ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Corporation): 10 parts by mass

Cationic polymerization initiator (trade name: CPI-100, 50% solution, manufactured by San-Apro Co., Ltd.): 4.5 parts by mass (substantial solid content: 2.25 parts by mass)

1,4-Ethoxynaphthalene: 2.0 parts by mass

(4) Fabrication of retardation laminated body

Corona treatment was performed on the retardation layer side of the first retardation layer with the first substrate layer and the retardation layer side of the second retardation layer with the second substrate layer. On one of the corona-treated surfaces, the prepared ultraviolet curable adhesive was applied, and the first retardation layer with the first base layer and the second retardation layer with the second base layer were bonded together. The ultraviolet curable adhesive is cured by irradiating ultraviolet rays from the second base layer side to form an adhesive layer. The thickness of the cured ultraviolet curable adhesive layer was 1.5 μm .

<Example 1>

(1) Production of optical laminates

An adhesive layer (A(410)=1.10, thickness 15 μm ) containing a light selective absorber was attached to the surface of the TAC film side of the linear polarizing plate obtained in Production Example 2. Next, the first substrate layer of the retardation laminate obtained in Production Example 3 was peeled off, and the above-mentioned linear polarizing plate was laminated on the exposed alignment layer so that the adhesive layer containing the light selective absorber came into contact.

Next, laminate A-1 with the TAC film side in contact with it via an adhesive layer (storage modulus: 25,500 Pa, refractive index at a wavelength of 550 nm: 1.47, haze: 0.2%, no light selective absorber) on the HC layer of the linear polarizer. Furthermore, an adhesive layer (storage modulus: 25,500Pa, refractive index at a wavelength of 550nm of 1.47, haze of 0.2%, and no light selective absorber) was laminated on the high refractive index layer of laminate A-1. . An alkali-free glass plate (refractive index 1.51 at a wavelength of 550 nm) was bonded to the adhesive layer to obtain an optical laminate including the optical functional layer A-1'.

(2) Measurement and evaluation of reflective properties

The reflectance Y and reflection hues a* and b* of the optical layered body obtained in the above (1) were measured using "Cm2600d" manufactured by Konica Minolta Corporation. The results are shown in Table 4. During the measurement, an adhesive layer (storage modulus: 25,500 Pa, at wavelength The refractive index at 550nm is 1.47, the haze is 0.2%, and does not contain a light selective absorber) to a glass plate (thickness 0.7mm, "EAGLE XG" manufactured by Corning Incorporated). The above-obtained optical laminate with a glass plate was placed on a reflective plate (reflectance: 96% or more, diffuse reflectance: 9% or less) with the optical function layer as the top, and the structure was reflective plate/air/ The measurement was performed in the state of the layer constitution of the glass plate/optical laminate. The reflectance Y of the optical layered body was evaluated in accordance with the following references. The results are shown in Table 4.

A: The reflectance Y is less than 6.0%.

B: The reflectance Y is 6.0% or more.

(3) Measurement and evaluation of light leakage

The second substrate layer was peeled and removed from the obtained optical layered body in (1) above, and an aluminum foil ("My Foil thick type 50" of aluminum foil manufactured by UACJ Corporation, thickness 20 μm ) was placed on the exposed surface with the non-glossy side laminated as a reflector. Under fluorescent light, visually observe the state of the above-mentioned slight light leakage at a distance of 30 cm upward from the viewing side (the side opposite to the aluminum foil) of the optical laminate, and evaluate according to the following criteria. The results are shown in Table 4.

A: Light leakage will not be recognized visually.

B: Light leakage will be recognized visually.

<Example 2, 3, 5, 6>

Except for using laminates A-2, A-3, A-4, and A-5 instead of laminate A-1, in the same manner as in Example 1, each of the optical function layers A-2' and A-3' was produced. , A-4', A-5' optical laminates, measure and evaluate reflection properties and light leakage. The results are shown in Table 4.

<Example 4>

An adhesive layer (A(410)=1.10, thickness 15 μm ) containing a light selective absorber was attached to the surface of the TAC film side of the linear polarizing plate obtained in Production Example 2. Next, in Production Example 3, the first base material layer of the obtained retardation laminate was peeled off, and the above-mentioned linear polarizing plate was laminated on the exposed alignment layer so that the adhesive layer containing the light selective absorber came into contact.

Next, on the HC layer of the linear polarizing plate, the laminate A- 3 was laminated in contact with the TAC film side to obtain an optical laminate including the optical functional layer A-3".

<Example 7, 8>

Except for using laminates A-4 and A-2 instead of laminates A-3, optical laminates each containing optical functional layers A-4", A-2" were produced in the same manner as in Example 4, and the reflection was measured and evaluated. nature and light leakage. The results are shown in Table 4.

<Comparative example 1>

An adhesive layer (A(410)=1.10, thickness 15 μm ) containing a light selective absorber was attached to the surface of the TAC film side of the linear polarizing plate obtained in Production Example 2. Next, the first substrate layer of the retardation laminate obtained in Production Example 3 was peeled off, and the above-mentioned linear polarizing plate was laminated on the exposed alignment layer so that the adhesive layer containing the light selective absorber was in contact with each other to produce an optical film. For the laminate, reflection properties and light leakage were measured and evaluated in the same manner as in Example 1. The results are shown in Table 4.

<Comparative example 2>

The linear polarizing plate of the optical laminate of Comparative Example 1 is interposed with an adhesive layer (storage modulus: 25,500Pa, refractive index at a wavelength of 550nm is 1.47, haze is 0.2%, does not contain light selective absorber) laminated alkali-free A glass plate (refractive index of 1.51 at a wavelength of 550 nm) was used to produce an optical layered body, and the reflection properties and light leakage were measured and evaluated in the same manner as in Example 1. The results are shown in Table 4.

Regarding the following partial laminate structures contained in the optical laminates of Comparative Example 1 and Comparative Example 2, the reflectance R (450), the reflectance R (550) and the reflectance R (630), and the reflectance ratio (reflectance Rate R (450) / reflectance R (550)), as shown in Table 3.

Comparative Example 1: HC-COP

Comparative example 2: glass plate/adhesive layer/HC-COP

[table 3]

<Comparative Examples 3 to 5>

Except for using the laminates B-1, B-2, and A-5 instead of the laminate A-3, each of the optical function layers B-1", B-2", and A-5" was produced in the same manner as in Example 4. The optical layered body was measured and evaluated for reflective properties and light leakage. The results are shown in Table 4.

[Table 4]

1: Optical functional layer (A)

2: Linear polarizer

3: phase difference layer

10: The first bonding layer

20: The second bonding layer

Claims (10)

An optical laminate comprising an optical functional layer (A), a linear polarizer, and a retardation layer with reverse wavelength dispersion in sequence, wherein, The ratio of the reflectance R(450) of the aforementioned optical functional layer (A) at a wavelength of 450nm to the reflectance R(550) at a wavelength of 550nm: R(450)/R(550) is not less than 1.07 and not more than 1.55, The aforementioned reflectance R (550) was less than 6.0%. The optical laminate according to claim 1, wherein the optical function layer (A) includes a high refractive index layer having a refractive index of 1.6 or higher at a wavelength of 550 nm. The optical laminate according to claim 2, wherein the optical function layer (A) includes a base film and the high refractive index layer laminated thereon. The optical laminate according to claim 1, wherein the ratio of the reflectance R(450) to the reflectance R(550): R(450)/R(550) is 1.07 to 1.35. The optical laminate according to claim 1, wherein the retardation layer includes one or more liquid crystal cured layers. The optical laminate according to claim 1, wherein the optical function layer (A) further includes a front plate. The optical laminate according to claim 1 further includes an adhesive layer disposed on the opposite side of the retardation layer to the linear polarizer. The optical laminate according to claim 7 further includes a separation film disposed on the side of the pressure-sensitive adhesive layer opposite to the retardation layer. The optical laminate according to claim 1 further has a protective film on the surface of the optical function layer (A) opposite to the linear polarizer. An image display device comprising the optical laminate described in any one of Claims 1 to 9.

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