KR20230018313A - Optical laminate - Google Patents

Abstract

The purpose of the present invention is to provide an optical laminate capable of satisfying the prevention of an orange peel, tolerance to a local load, and prevention of a warp in a high-temperature and high-humidity environment, in a well-balanced manner. The optical laminate includes: a polarizer; a first optical functional body bonded to a visible side of the polarizer through a first adhesive layer; a reinforcement layer bonded to a visible side of the first optical functional body through a second adhesive layer; and a second optical functional body bonded to a visible side of the reinforcement layer through a third adhesive layer. The first adhesive layer, the second adhesive layer, and the third adhesive layer are each 17 μm thick or less. The total sum of the thickness of the first optical functional body, the thickness of the reinforcement layer, and the thickness of the second optical functional body is 200 μm or less.

Description

Optical laminate {OPTICAL LAMINATE}

The present invention relates to an optical laminate.

In recent years, image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices (eg, organic EL display devices and inorganic EL display devices) are rapidly spreading. An optical laminate comprising a polarizing plate and an optical functional layer (for example, an anti-reflective layer and an antireflection layer) is typically used in an image display device. As such an optical laminate, for example, a polarizing plate with an antireflection layer and an antireflective layer is known (for example, Patent Document 1). In a polarizing plate with an anti-reflective layer and an anti-reflective layer, an anti-reflective laminate containing an anti-reflective layer is bonded to the visible side of the polarizing plate through an adhesive layer, and the anti-reflective laminate containing the anti-reflective layer is attached to the visible side of the anti-reflective laminate. are connected through However, in the case of a polarizing plate with an antireflection layer and an antireflective layer, minute concavities and convexities called orange peel are generated on the surface on the viewer side, and the display performance of the image display device may be adversely affected.

In addition, a local load may be applied to an optical laminate used in an image display device. Depending on the configuration of the optical layered body, the polarizing plate may be damaged by such a local load, resulting in light leakage or bright spots (so-called white dots) in the image display device. In addition, there is a problem that warpage easily occurs in an optical layered body provided with a plurality of optical function layers in a high-humidity environment.

Japanese Unexamined Patent Publication No. 2018-155998

The present invention has been made to solve the above conventional problems, and its main object is to provide an optical laminate capable of satisfying well-balanced suppression of orange peel, resistance to local load, and suppression of warpage in a high-humidity environment. is in doing

An optical laminate according to an embodiment of the present invention includes a polarizing plate, a first optical functional body bonded to the visual side of the polarizing plate via a first adhesive layer, and a second adhesive layer to the visible side of the first optical functional body. a reinforcing layer bonded through and through and a second optical functional body bonded through a third pressure-sensitive adhesive layer on a visual side of the reinforcing layer, wherein each thickness of the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the third pressure-sensitive adhesive layer is provided. is 17 μm or less, and the total sum of the thickness of the first optical function body, the thickness of the reinforcing layer, and the thickness of the second optical function body is 200 μm or less.

In one embodiment, the first optical functional body is an anti-bleaching laminate, and the anti-bleaching laminate is disposed on an anti-bleaching layer contacting the first pressure-sensitive adhesive layer and on a viewing side of the anti-bleaching layer, 2 includes a first substrate in contact with the pressure-sensitive adhesive layer.

In one embodiment, the second optical functional body is an antireflection laminate, and the antireflection laminate includes a second substrate in contact with the third adhesive layer, and a hard disk disposed on the visual side of the second substrate. It includes a coating layer and an antireflection layer disposed on the viewing side of the hard coat layer.

In one embodiment, the antireflection layer is located on the outermost surface of the optical laminate, and the antireflection layer has a water vapor transmission rate of 0.1 g/mm ² or less.

In one embodiment, the polarizing plate includes a polarizer and a protective layer disposed on a viewing side of the polarizer and in contact with the first pressure-sensitive adhesive layer.

In one embodiment, the thickness of the said polarizer is 10 micrometers or less.

In one embodiment, the optical layered body further includes a first retardation layer and a second retardation layer disposed in order from the polarizing plate side on the opposite side of the viewing side of the polarizing plate, and the first retardation layer is nx>ny > nz, and the second retardation layer exhibits refractive index characteristics of nz > nx > ny.

According to an embodiment of the present invention, the thickness of each pressure-sensitive adhesive layer is set to the above upper limit or less, a reinforcing layer is formed between the first optical functional body and the second optical functional body, and furthermore, the first optical functional body, the reinforcing layer and the second optical functional body are formed. By making the total thickness of the optical functional body less than or equal to the above upper limit, an optical laminate that satisfies suppression of orange peel, resistance to local load, and suppression of warpage in a high-humidity environment with a good balance can be realized.

1 is a schematic cross-sectional view of an optical stack according to one embodiment of the present invention.

Hereinafter, representative embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

(Definition of Terms and Symbols)

Definitions of terms and symbols in this specification are as follows.

(1) Refractive index (nx, ny, nz)

"nx" is the refractive index in the direction in which the in-plane refractive index is maximized (ie, the slow axis direction), "ny" is the refractive index in the direction orthogonal to the slow axis within the plane (ie, the fast axis direction), and "nz" is is the refractive index in the thickness direction.

(2) In-plane phase difference (Re)

"Re(λ)" is an in-plane retardation of a film measured with light having a wavelength of λ nm at 23°C. For example, "Re(450)" is an in-plane retardation of a film measured with light having a wavelength of 450 nm at 23°C. Re (λ) is obtained by the formula: Re = (nx-ny) × d when the thickness of the film is set to d (nm).

(3) Phase difference in thickness direction (Rth)

“Rth(λ)” is the phase difference in the thickness direction of the film measured with light having a wavelength of λ nm at 23°C. For example, "Rth (450)" is a phase difference in the thickness direction of the film measured with light having a wavelength of 450 nm at 23°C. Rth(λ) is obtained by the formula: Rth=(nx-nz)×d when the thickness of the film is set to d (nm).

(4) Nz coefficient

The Nz coefficient is obtained by Nz=Rth/Re.

(5) Angle

When referred to as an angle in this specification, unless otherwise specified, the angle includes angles in both clockwise and counterclockwise directions.

A. Overall configuration of the optical stack

1 is a schematic cross-sectional view of an optical stack according to one embodiment of the present invention. The optical layered body 1 of the illustrated example includes a polarizing plate 2, a first optical functional body 3 bonded to the viewing side of the polarizing plate 2 via a first adhesive layer 61, and a first optical functional body ( 3) The reinforcing layer 5 bonded to the visual side of the reinforcing layer 5 through the second adhesive layer 62, and the second optical functional body 4 bonded to the visual side of the reinforcing layer 5 through the third adhesive layer 63 to provide That is, the second optical functional body 4, the third adhesive layer 63, the reinforcing layer 5, the second adhesive layer 62, the first optical functional body 3, and the first adhesive layer (61) and the polarizing plate (2) are laminated in this order from the viewing side of the optical laminate (1).

The thickness of each of the first pressure sensitive adhesive layer 61, the second pressure sensitive adhesive layer 62, and the third pressure sensitive adhesive layer 63 is 17 μm or less, preferably 15 μm or less, and typically 5 μm or more. The first pressure sensitive adhesive layer 61, the second pressure sensitive adhesive layer 62, and the third pressure sensitive adhesive layer 63 may have the same thickness or may have different thicknesses. In one embodiment of the present invention, the first pressure-sensitive adhesive layer 61, the second pressure-sensitive adhesive layer 62, and the third pressure-sensitive adhesive layer 63 have the same thickness as each other.

The total sum of the thickness of the first optical functional element 3, the thickness of the reinforcing layer 5, and the thickness of the second optical functional element 4 is 200 µm or less, preferably 180 µm or less, more preferably 170 µm or less. It is ㎛ or less, and is typically 140 ㎛ or more.

The orange peel that occurs on the surface of the optical layered body on the visual side may be caused by unevenness of the pressure-sensitive adhesive layer. On the other hand, in the configuration as described above, since the thickness of each pressure-sensitive adhesive layer is equal to or less than the above upper limit, it is possible to suppress that the unevenness of the pressure-sensitive adhesive layer affects the surface of the optical layered body on the visual side of the optical layered body. The occurrence of orange peel on the surface can be suppressed. However, if the thickness of each pressure-sensitive adhesive layer is less than the above upper limit, there is a possibility that the resistance of the optical laminate to a local load may decrease. In this respect, with the above configuration, since the reinforcing layer is formed between the first optical functional body and the second optical functional body, cracks do not occur even when a load of a predetermined value or more is locally applied to the optical laminated body, As a result, an image display device in which light leakage and bright spots (white dots) are suppressed can be realized. In addition, since the total sum of the thickness of the first optical functional element, the thickness of the reinforcing layer, and the thickness of the second optical functional element is equal to or less than the above upper limit, even if the reinforcing layer is formed between the first optical functional element and the second optical function element, it is not possible to operate under a high humidity environment. The curvature of the optical layered body in the case can be suppressed. Therefore, it is possible to realize an optical laminate that satisfies suppression of orange peel, resistance to local load, and suppression of curvature in a high-humidity environment with a good balance.

In one embodiment of the present invention, the optical layered body 1 includes a first retardation layer 7 and a second retardation layer ( 8) is further provided. The first retardation layer 7 preferably exhibits a refractive index characteristic of nx>ny>nz. The second retardation layer 8 preferably exhibits a refractive index characteristic of nz>nx>ny. According to this configuration, it is possible to impart a desired optical compensation function to the optical layered body 1 .

Moreover, in one Embodiment of this invention, the optical laminated body 1 is further equipped with the panel side adhesive layer 9. The panel-side adhesive layer 9 is disposed on the opposite side of the first retardation layer 7 to the second retardation layer 8 . When the optical layered body 1 is equipped with the panel side adhesive layer 9, the optical layered body 1 can be attached to the image display cell by the panel side adhesive layer 9.

Further, in one embodiment of the present invention, the thickness of the optical layered body 1 is typically 330 μm or less, preferably 310 μm or less, more preferably 300 μm or less, and typically 250 μm or more. , preferably 270 μm or more.

According to this structure, since the thickness of the optical laminated body 1 is below the said upper limit, the warp of the optical laminated body in a high-humidity environment can be suppressed stably. Moreover, since the thickness of the optical laminate 1 is equal to or greater than the lower limit, generation of cracks can be stably suppressed even when a load of a predetermined value or more is locally applied to the optical laminate.

Hereinafter, the components of the optical laminate will be described.

B. Polarizer

In one embodiment of the present invention, the polarizing plate 2 includes a polarizer 21 and a protective layer 22 disposed on the viewing side of the polarizer 21 . The protective layer 22 is typically bonded to the visual side of the polarizer 21 through an arbitrary appropriate adhesive layer (adhesive layer, adhesive layer: not shown). That is, the polarizing plate 2 may consist of the polarizer 21, the adhesive layer, and the protective layer 22. The protective layer 22 is located between the polarizer 21 and the first pressure sensitive adhesive layer 61 and is in contact with the first pressure sensitive adhesive layer 61 . The protective layer 22 is pressure-sensitively bonded to the first pressure-sensitive adhesive layer 61 . In addition, the polarizing plate 2 may further include a second protective layer on the side opposite to the viewing side of the polarizer 21 .

B-1. polarizer

As the polarizer 21, any suitable polarizer can be employed. For example, the resin film forming the polarizing plate 2 may be a single-layer resin film or a laminate of two or more layers.

As a specific example of the polarizer comprised from the resin film of a single layer, the thing to which the dyeing process by iodine and the extending|stretching process (typically uniaxial stretching) were given to the PVA system resin film is mentioned. Dyeing with iodine is performed, for example, by immersing a PVA-based film in an aqueous solution of iodine. The draw ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after dyeing treatment, or may be performed while dyeing. Moreover, you may dye after extending|stretching. Swelling treatment, crosslinking treatment, washing treatment, drying treatment and the like are given to the PVA-based resin film as necessary. For example, by immersing the PVA-based resin film in water and washing it with water before dyeing, not only can dirt and antiblocking agents on the surface of the PVA-based film be cleaned, but also the PVA-based resin film can be swollen to prevent uneven coloring and the like. .

As a specific example of a polarizer obtained using a laminate, a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer applied and formed on the resin substrate A polarizer obtained using a sieve is exemplified. A polarizer obtained by using a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate, for example, by applying a PVA-based resin solution to the resin substrate and drying it to form a PVA-based resin layer on the resin substrate Obtaining a laminated body of a resin substrate and a PVA-based resin layer; It may be produced by stretching and dyeing the laminate to use a PVA-based resin layer as a polarizer. In one embodiment of the present invention, preferably, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically involves immersing the layered product in an aqueous solution of boric acid and then extending it. In addition, if necessary, the stretching may further include air stretching the laminate at a high temperature (eg, 95° C. or higher) prior to stretching in a boric acid aqueous solution. In addition, in one embodiment of the present invention, preferably, the laminate is subjected to a drying shrinkage treatment in which it shrinks by 2% or more in the width direction by heating while conveying in the longitudinal direction. Typically, the manufacturing method of the present embodiment includes subjecting the laminate to an air assisted stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment in this order. By introducing auxiliary stretching, even when applying PVA on a thermoplastic resin, it becomes possible to improve the crystallinity of PVA and achieve high optical properties. In addition, by simultaneously increasing the orientation of PVA in advance, it is possible to prevent problems such as deterioration in orientation or dissolution of PVA when immersed in water in a subsequent dyeing step or drawing step, and to achieve high optical properties. . Further, in the case where the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to the case where the PVA-based resin layer does not contain a halide. Thereby, the optical characteristics of the polarizer obtained through the processing process performed by immersing a layered product in liquid, such as a dyeing process and an underwater extension process, can be improved. In addition, optical properties can be improved by shrinking the laminate in the width direction by drying shrinkage treatment. The obtained laminate of the resin substrate/polarizer may be used as it is (that is, the resin substrate may be used as a protective layer for the polarizer), and the resin substrate is peeled from the laminate of the resin substrate/polarizer, and the peeling surface is optionally used according to the purpose. An appropriate protective layer of may be laminated and used. The details of the manufacturing method of such a polarizer are described in Unexamined-Japanese-Patent No. 2012-73580 and Japanese Patent No. 6470455, for example. These publications are incorporated herein by reference in their entirety.

The polarizer 21 is preferably composed of a laminate of two or more layers, more preferably a laminate of a resin substrate and a PVA-based resin layer applied to the resin substrate.

The thickness of the polarizer 21 is preferably 15 μm or less, more preferably 12 μm or less, even more preferably 10 μm or less, particularly preferably 8 μm or less, typically 1 μm or more, preferably 3 μm or less. more than μm. If the thickness of the polarizer is within this range, the occurrence of warping of the optical laminate in a high-humidity environment can be more stably suppressed.

The polarizer 21 preferably exhibits absorption dichroism at any one of the wavelengths of 380 nm to 780 nm. The single transmittance of the polarizer 21 is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer 21 is preferably 97.0% or more, more preferably 99.0% or more, still more preferably 99.9% or more.

B-2. protective layer

The protective layer 22 is formed of any suitable film that can be used as a protective layer of the polarizer 21 . Specific examples of the main component of the film include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, and transparent resins such as polysulfone, polystyrene, polynorbornene, polyolefin, (meth)acrylic, and acetate resins. Further, thermosetting resins such as (meth)acrylic, urethane-based, (meth)acrylurethane-based, epoxy-based, and silicone-based resins or ultraviolet curable resins may be used. In addition, "(meth)acrylic resin" refers to acrylic resin and/or methacrylic resin. In addition to this, glassy type polymers, such as a siloxane type polymer, are also mentioned, for example. Moreover, the polymer film of Unexamined-Japanese-Patent No. 2001-343529 (WO01/37007) can also be used. As the material for this film, a resin composition containing, for example, a thermoplastic resin having a substituted or unsubstituted imide group in its side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in its side chain can be used. For example, , a resin composition comprising an alternating copolymer composed of isobutene and N-methylmaleimide, and an acrylonitrile/styrene copolymer. The polymer film may be, for example, an extrusion molding of the resin composition.

In one embodiment of the present invention, the protective layer 22 contains a (meth)acrylic resin. As the (meth)acrylic resin, a (meth)acrylic resin having a glutarimide structure is used, for example. A (meth)acrylic resin having a glutarimide structure is, for example, Japanese Patent Laid-Open No. 2006-309033, Japanese Patent Laid-Open No. 2006-317560, Japanese Patent Laid-Open No. 2006-328329, Japanese Patent Laid-Open 2006-328334 No., Japanese Unexamined Patent Publication No. 2006-337491, Japanese Unexamined Patent Publication No. 2006-337492, Japanese Unexamined Patent Publication No. 2006-337493, Japanese Unexamined Patent Publication No. 2006-337569, Japanese Unexamined Patent Publication No. 2007-009182, Japanese Patent It describes in Unexamined-Japanese-Patent No. 2009-161744 and Unexamined-Japanese-Patent No. 2010-284840. These descriptions are incorporated herein by reference.

The thickness of the protective layer 22 is typically 300 μm or less, preferably 100 μm or less, more preferably 5 μm to 80 μm, still more preferably 10 μm to 60 μm. In addition, when surface treatment is performed, the thickness of the protective layer 22 is the thickness including the thickness of the surface treatment layer.

C. First optical functional body

The first optical functional body 3 can impart a desired optical function to the optical layered body 1 . As the first optical functional body 3, for example, an anti-reflective laminate and a sunglasses countermeasure laminate are exemplified.

The thickness of the first optical functional element 3 is typically 20 μm to 60 μm, preferably 30 μm to 50 μm.

In one embodiment of this invention, the 1st optical function body 3 is the anti-see-through laminated body 3a. The anti-bleaching laminate 3a includes an anti-bleaching layer 32 and a first substrate 31 disposed on the viewing side of the anti-bleaching layer 32 . The see-through prevention layer 32 is supported by the first substrate 31 . The anti-see through layer 32 is disposed on the viewing side with respect to the protective layer 22 and is bonded to the protective layer 22 via the first pressure sensitive adhesive layer 61 . The see-through prevention layer 32 is in contact with the first pressure sensitive adhesive layer 61 and is pressure-sensitively bonded to the first pressure sensitive adhesive layer 61 . The first substrate 31 is located on the opposite side of the first pressure-sensitive adhesive layer 61 to the anti-see through layer 32 . The first substrate 31 is in contact with the second pressure-sensitive adhesive layer 62 and is pressure-sensitively bonded to the second pressure-sensitive adhesive layer 62 .

C-1. see-through prevention layer

The anti-bleaching layer 32 is formed to prevent the reflection of a user's face of the image display device, a keyboard of the image display device, and external light (eg, fluorescent light). In one embodiment of the present invention, the anti-reflective layer 32 is an orientation-hardened layer of a liquid crystal compound. In this specification, the "alignment fixed layer" refers to a layer in which a liquid crystal compound is aligned in a predetermined direction within the layer and the alignment state is fixed. In addition, the "alignment hardened layer" is a concept including an alignment hardened layer obtained by curing a liquid crystal monomer. The liquid crystal compound may be a rod-shaped liquid crystal compound, a discotic (disk-shaped) liquid crystal compound, or a combination thereof.

In one embodiment of the present invention, the anti-reflective layer 32 includes a discotic liquid crystal compound. More specifically, the anti-reflective layer 32 is a layer in which a discotic liquid crystal compound is fixed in a state in which it is aligned in a predetermined direction. In discotic liquid crystal compounds, generally, a cyclic parent nucleus such as benzene, 1,3,5-triazine, calixarene, etc. is arranged at the center of the molecule, and a straight-chain alkyl group, alkoxy group, substituted benzoyloxy group, etc. are attached to the side chain. It refers to a liquid crystal compound having a disk-shaped molecular structure substituted radially. As a representative example of a discotic liquid crystal, a research report by C. Destrade team, Mol. Cryst. Liq. Cryst. Benzene derivatives, triphenylene derivatives, thruxene derivatives, and phthalocyanine derivatives described in Volume 71, page 111 (1981), B. Kohne's research report, Angew. Chem. Cyclohexane derivatives described in Vol. 96, page 70 (1984) and the research report of J. M. Lehn's team, J. Chem. Soc. Chem. Commun., page 1794 (1985), J. Zhang's research report, J. Am. Chem. Soc. The azacrown type and phenylacetylene type macrocycles described in Volume 116, page 2655 (1994) are exemplified. As another specific example of the discotic liquid crystal compound, for example, Japanese Unexamined Patent Publication No. 2006-133652, Japanese Unexamined Patent Publication No. 2007-108732, Japanese Unexamined Patent Publication No. 2010-244038, Japanese Unexamined Patent Publication No. 2014-214177 The compounds described can be mentioned. Descriptions of the above documents and publications are incorporated herein by reference. The anti-reflective layer containing the discotic liquid crystal compound may be a so-called negative A plate that typically has a refractive index characteristic of nx=nz>ny.

In another embodiment, the anti-reflective layer 32 contains a rod-shaped liquid crystal compound. More specifically, in the anti-reflective layer, the rod-like liquid crystal compounds are aligned in a predetermined direction (typically, the slow axis direction) and are aligned (homogeneous orientation). Examples of the rod-shaped liquid crystal compound include a liquid crystal compound (nematic liquid crystal) in which the liquid crystal phase is a nematic phase. As such a liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. The mechanism for developing the liquid crystalline properties of the liquid crystal compound may be either lyotropic or thermotropic. The liquid crystal polymer and the liquid crystal monomer may be used alone or in combination. As the liquid crystal monomer, any suitable liquid crystal monomer can be employed. For example, polymerizable hydrogen compounds described in Japanese Patent Publication No. 2002-533742 (WO00/37585), EP358208 (US5211877), EP66137 (US4388453), WO93/22397, EP0261712, DE19504224, DE4408171, GB2280445, etc. can be used. there is. Specific examples of such a polymerizable mesogenic compound include LC242 (trade name) from BASF, E7 (trade name) from Merck, and LC-Sillicon-CC3767 (trade name) from Wacker-Chem. As the liquid crystal monomer, for example, a nematic liquid crystal monomer is preferable. The specific example of a liquid crystal compound is described in Unexamined-Japanese-Patent No. 2006-163343, for example. The description of the above publication is incorporated herein by reference. The anti-reflective layer containing a rod-shaped liquid crystal compound may be a so-called positive A plate having a refractive index characteristic of typically nx > ny = nz.

The anti-see through layer 32 can typically function as a λ/2 plate. When the anti-bleaching layer 32 functions as a λ/2 plate, by controlling the orientation angle (or direction of the slow axis) thereof, the anti-bleaching layer 32 can be prevented satisfactorily. The in-plane retardation Re (550) of the anti-reflective layer 32 is 220 nm to 320 nm, more preferably 240 nm to 300 nm, still more preferably 250 nm to 280 nm.

The angle between the slow axis of the anti-reflective layer 32 and the absorption axis of the polarizer 21 is preferably 35° to 55°, more preferably 40° to 50°, still more preferably about 45°. By arranging the anti-bleaching layer 32 functioning as a λ/2 plate at such an axial angle, it is possible to satisfactorily prevent see-through.

The thickness of the see-through prevention layer 32 is preferably 1 μm to 5 μm, more preferably 1 μm to 3 μm.

When an alignment film is used for alignment of the liquid crystal compound, the anti-reflective layered body 3a further includes an alignment film between the anti-reflective layer 32 and the first substrate 31 . That is, the anti-bleaching laminate 3a may consist of the anti-bleaching layer 32, the alignment film, and the first substrate 31. An alignment film generally contains a polymer material as a main component. Representative examples of polymer materials include polyvinyl alcohol, polyimide, and derivatives thereof. In one embodiment of the present invention, modified or unmodified polyvinyl alcohol is preferred. As the alignment film, for example, WO01/88574A1 and modified polyvinyl alcohol described in Japanese Patent No. 3907735 can be used. Orientation treatment is typically applied to the alignment film. Representative examples of alignment treatment include rubbing treatment and photo-alignment treatment. Since the rubbing process is well known in the industry, a detailed description is omitted. As the alignment film (photo-alignment film) subjected to the optical alignment process, for example, those described in WO2005/096041, trade name LPP-JP265CP manufactured by Rolic Technologies, etc. can be used. The thickness of the alignment film is, for example, 0.01 µm to 10 µm, preferably 0.01 µm to 1 µm, and more preferably 0.01 µm to 0.5 µm.

The see-through prevention layer 32 can be formed, for example, in the following procedure. First, a coating solution for forming an alignment layer is applied on the first substrate 31 and dried to form a coating layer. A rubbing treatment is performed on the coated film in a predetermined direction, and an alignment film is formed on the first substrate 31 . The predetermined direction may correspond to a direction of a slow axis of the resulting anti-see through layer 32 . Next, a coating liquid for forming an anti-reflective layer (for example, a solution containing a liquid crystal compound and, if necessary, a crosslinkable monomer) is applied on the formed alignment layer and heated. While removing the solvent of the coating liquid by heating, orientation of the liquid crystal compound is promoted. Heating may be performed in one step or may be performed in multiple steps by changing the temperature. Next, the alignment of the liquid crystal compound is fixed by crosslinking (or polymerizing) the crosslinkable (or polymerizable) monomer by irradiation with ultraviolet light. In this way, the anti-see through layer 32 is formed on the first substrate 31 (substantially, on the alignment film). In addition, a method for orienting a discotic liquid crystal compound is described in, for example, Japanese Unexamined Patent Publication No. 2014-214177, and a method for orienting a rod-shaped liquid crystal compound is described in, for example, Japanese Unexamined Patent Publication No. 2006-163343 there is. Descriptions of these publications are incorporated herein by reference. In addition, the alignment layer may be omitted depending on the desired alignment state and the type of liquid crystal compound.

C-2. 1st entry

The first substrate 31 is used to form the see-through prevention layer 32 .

As the first substrate 31, any suitable resin film is used. Examples of the material for forming the resin film include polyester resins such as polyethylene terephthalate (PET), cycloolefin resins such as norbornene resins, cycloolefins (eg norbornene) and α-olefins (eg Examples thereof include cellulose-based resins such as resins obtained by addition polymerization of ethylene (COC) and triacetyl cellulose (TAC). In one embodiment of the present invention, the first substrate 31 includes a TAC-based resin.

The thickness of the first substrate 31 can be appropriately set according to the purpose. The thickness of the first substrate 31 is typically 20 μm to 200 μm, preferably 25 μm to 100 μm, and more preferably 30 μm to 50 μm.

D. Reinforcing layer

The reinforcing layer 5 imparts excellent resistance to local loads to the optical stack 1 . In one embodiment of the present invention, the reinforcing layer 5 is bonded to the first substrate 31 via the second pressure-sensitive adhesive layer 62 . The reinforcing layer 5 is disposed between the second pressure sensitive adhesive layer 62 and the third pressure sensitive adhesive layer 63 . The reinforcing layer 5 is in contact with the second pressure sensitive adhesive layer 62 and the third pressure sensitive adhesive layer 63 and is pressure-sensitively bonded to the second pressure sensitive adhesive layer 62 and the third pressure sensitive adhesive layer 63 .

The reinforcing layer 5 is formed of any suitable film. As a specific example of the material used as the main component of the reinforcing layer 5, for example, the same material used as the main component of the protective layer 22 described in section B-2 above (transparent resin described above, thermosetting resin described above) or an ultraviolet curable resin, the above glassy polymer, and the above resin composition). In one embodiment of the present invention, the reinforcing layer 5 contains a (meth)acrylic resin, preferably a (meth)acrylic resin having a glutarimide structure. That is, each of the protective layer 22 and the reinforcing layer 5 includes a (meth)acrylic resin. By using (meth)acrylic resin as the protective layer 22 and the reinforcing layer 5, light leakage can be stably suppressed when a load of a predetermined value or more is locally applied to the optical laminate 1. .

In addition, similarly to the protective layer 22, the reinforcing layer 5 may be subjected to the above-described surface treatment and/or the above-described treatment to improve visibility as necessary.

The thickness of the reinforcing layer 5 is typically 20 μm to 70 μm, preferably 30 μm to 50 μm. When the thickness of the reinforcing layer 5 is within this range, excellent resistance to local load can be imparted to the optical laminate 1, and warpage of the optical laminate 1 in a high-humidity environment can be sufficiently suppressed. there is.

E. Second optical functional body

The second optical functional body 4 can impart an optical function different from that of the first optical functional body 3 to the optical layered body 1 . As the 2nd optical function body 4, an antireflection laminated body, a sunglasses protection laminated body, etc. are mentioned, for example.

The thickness of the second optical functional element 4 is typically 40 µm to 120 µm, and preferably 70 µm to 100 µm or less.

In one embodiment of the present invention, the second optical function body 4 is an antireflection laminate 4a. The antireflection laminate 4a includes a second substrate 41, a hard coat layer 42 disposed on the visual side of the second substrate 41, and an antireflection layer disposed on the visual side of the hard coat layer 42. (43). That is, the antireflection laminate 4a may consist of the second substrate 41, the hard coat layer 42, and the antireflection layer 43. The second base material 41 is disposed on the viewing side with respect to the reinforcing layer 5 and is bonded to the reinforcing layer 5 via the third adhesive layer 63 . The second substrate 41 is in contact with the third pressure-sensitive adhesive layer 63 and is pressure-sensitively bonded to the third pressure-sensitive adhesive layer 63 . In one embodiment of the present invention, the hard coat layer 42 is formed directly on the surface of the second substrate 41 on the visual side. In this specification, “directly” means that no adhesive layer or pressure-sensitive adhesive layer is intervened. In addition, the antireflection layer 43 is directly formed on the surface of the hard coat layer 42 on the viewing side.

E-1. 2nd entry

The second substrate 41 is used to form the hard coat layer 42 and the antireflection layer 43 . As the second substrate 41, any suitable resin film is used. As the material for forming the second base material 41, for example, the same material as for the material for forming the first base material 31 described in section C-2 above (the above-described polyester-based resin, the above-mentioned cycloolefin-based resin, resins obtained by addition polymerization of cycloolefins and α-olefins described above, and cellulose-based resins described above). In one embodiment of the present invention, the second substrate 41 includes a TAC-based resin.

The thickness of the second substrate 41 may be appropriately set according to the purpose. The thickness of the second substrate 41 is typically 20 μm to 200 μm, preferably 50 μm to 150 μm, and more preferably 70 μm to 90 μm.

E-2. hard coat layer

The hard coat layer 42 can impart excellent pencil hardness to the optical laminate 1 . In addition, the reflectance of the optical laminate 1 can be further reduced by appropriately adjusting the difference in refractive index between the hard coat layer 42 and the antireflection layer 43 .

The hard coat layer 42 preferably has sufficient surface hardness, excellent mechanical strength, and excellent light transmittance. The hard coat layer 42 may be formed of any suitable resin as long as it has these desired properties. Specific examples of the resin include thermosetting resins, thermoplastic resins, ultraviolet curable resins, electron beam curable resins, and two-component mixed resins. Among the resins forming the hard coat layer 42, an ultraviolet curable resin is preferable. If the resin is an ultraviolet curable resin, the hard coat layer 42 can be formed with simple operation and high efficiency.

Specific examples of the UV curable resin include polyester, acrylic, urethane, amide, silicone, and epoxy UV curable resins. UV-curable resins include UV-curable monomers, oligomers, and polymers. As a preferable ultraviolet-curable resin, the resin composition containing the acrylic monomer component or oligomer component which has preferably 2 or more, more preferably 3-6 functional groups of ultraviolet polymerization is mentioned. Typically, a photopolymerization initiator is blended with the ultraviolet curable resin.

The hard coat layer 42 may be formed by any suitable method. For example, the hard coat layer 42 may be formed by coating a resin composition for forming a hard coat layer on the second substrate 41, drying it, and curing the dried coating film by irradiating ultraviolet rays.

The thickness of the hard coat layer 42 is, for example, 0.5 μm to 20 μm, preferably 1 μm to 15 μm.

Details about the hard coat layer and the close contact structure between the hard coat layer and the antireflection layer are described in, for example, Japanese Unexamined Patent Publication No. 2016-224443. The description of the above publication is incorporated herein by reference.

E-3. antireflection layer

The antireflection layer 43 is formed to prevent reflection of external light (eg, fluorescent light) or the like. As the structure of the antireflection layer 43, any appropriate structure can be adopted. Representative structures of the antireflection layer 43 include (1) a single layer of a low refractive index layer having an optical film thickness of 120 nm to 140 nm and a refractive index of about 1.35 to 1.55; (2) a laminate comprising a medium refractive index layer, a high refractive index layer, and a low refractive index layer in order from the second substrate 41; (3) an alternating multi-layer laminate of a high refractive index layer and a low refractive index layer; can be heard

Examples of the material capable of forming the low refractive index layer include silicon oxide (SiO ₂ ) and magnesium fluoride (MgF ₂ ). The refractive index of the low refractive index layer is typically about 1.35 to 1.55. Examples of the material capable of forming the high refractive index layer include titanium oxide (TiO ₂ ), niobium oxide (Nb ₂ O ₃ or Nb ₂ O ₅ ), tin-doped indium oxide (ITO), and antimony-doped tin oxide (ATO). ), and ZrO ₂ -TiO ₂ . The refractive index of the high refractive index layer is typically about 1.60 to 2.20. Examples of the material capable of forming the medium refractive index layer include titanium oxide (TiO ₂ ), a mixture of a material capable of forming a low refractive index layer and a material capable of forming a high refractive index layer (eg, titanium oxide). and a mixture of silicon peroxide). The refractive index of the medium refractive index layer is typically about 1.50 to 1.85. The thickness of the low refractive index layer, the medium refractive index layer and the high refractive index layer can be set so as to realize an appropriate optical film thickness according to the layer structure of the antireflection layer, desired antireflection performance, and the like.

The antireflection layer 43 is typically formed by a dry process. Specific examples of the dry process include a physical vapor deposition (PVD) method and a chemical vapor deposition (CVD) method. Examples of the PVD method include a vacuum deposition method, a reactive vapor deposition method, an ion beam assist method, a sputtering method, and an ion plating method. As the CVD method, a plasma CVD method is exemplified. The dry process for forming the antireflection layer 43 is preferably a sputtering method.

The thickness of the antireflection layer 43 is, for example, about 20 nm to 300 nm.

In the antireflection layer 43, the difference between the maximum reflectance and the minimum reflectance in the wavelength range of 400 nm to 700 nm is preferably 2.0% or less, more preferably 1.9% or less, still more preferably 1.8% or less. When the difference between the maximum reflectance and the minimum reflectance is within this range, staining of the reflected light can be well prevented.

In one embodiment of the present invention, the antireflection layer 43 is located on the outermost surface of the optical laminate 1 on the viewing side. The water vapor transmission rate of the antireflection layer 43 is typically 1.0 g/mm ² or less, preferably 0.1 g/mm ² or less, and is typically 0.01 g/mm ² or more. In addition, the moisture permeability can be measured as the amount of water vapor (g) passing through a sample having an area of 1 m ² in an atmosphere at a temperature of 40° C. and a humidity of 92% RH in 24 hours in accordance with the moisture permeability test (cup method) of JIS Z0208. When the moisture permeability of the antireflection layer 43 located on the outermost surface is equal to or less than the above upper limit, the warpage of the optical laminate 1 in a high humidity environment can be more stably suppressed.

In addition, the antireflection layer 43 does not have to be located on the outermost surface of the optical laminate 1 . In the antireflection laminate 4a, an outermost layer may be formed on the viewing side of the antireflection layer 43, if necessary. That is, the antireflection laminate 4a may consist of the second substrate 41, the hard coat layer 42, the antireflection layer 43, and the outermost surface layer. The range of the moisture permeability of the outermost surface layer is the same as the range of the moisture vapor permeability of the antireflection layer 43 described above. As an outermost surface layer, an antifouling layer is mentioned, for example. The antifouling layer contains, for example, a fluorine group-containing silane-based compound (for example, an alkoxysilane compound having a perfluoropolyether group) or a fluorine group-containing organic compound. The antifouling layer preferably exhibits water repellency with a water contact angle of 110 degrees or more.

F. The first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the third pressure-sensitive adhesive layer

Each of the first pressure-sensitive adhesive layer 61, the second pressure-sensitive adhesive layer 62, and the third pressure-sensitive adhesive layer 63 is formed of a pressure-sensitive adhesive (pressure-sensitive adhesive). More specifically, the first pressure-sensitive adhesive layer 61 is formed by coating a pressure-sensitive adhesive on the protective layer 22 of the polarizing plate 2 to the thickness described above. The second pressure-sensitive adhesive layer 62 is formed by coating the pressure-sensitive adhesive on the first substrate 31 of the first optical functional body 3 so as to have the thickness described above. The third adhesive layer 63 is formed by applying an adhesive to the reinforcing layer 5 to the thickness described above. The first pressure sensitive adhesive layer 61, the second pressure sensitive adhesive layer 62, and the third pressure sensitive adhesive layer 63 may be formed of the same pressure sensitive adhesive or may be formed of mutually different pressure sensitive adhesives. In one embodiment of the present invention, the first pressure-sensitive adhesive layer 61, the second pressure-sensitive adhesive layer 62, and the third pressure-sensitive adhesive layer 63 are formed of the same pressure-sensitive adhesive. When the first pressure sensitive adhesive layer 61, the second pressure sensitive adhesive layer 62, and the third pressure sensitive adhesive layer 63 are formed of the same pressure sensitive adhesive, the manufacturing cost of the optical laminate 1 can be reduced.

The pressure-sensitive adhesive typically contains a (meth)acrylic polymer, a urethane polymer, a silicone polymer or a rubber polymer as a base polymer. When a (meth)acrylic polymer is used as the base polymer, the pressure-sensitive adhesive layer is formed of, for example, a pressure-sensitive adhesive containing a (meth)acrylic polymer.

F-1. (meth)acrylic polymer

The (meth)acrylic polymer contains a polymer of a monomer component (raw monomer) containing an alkyl (meth)acrylate as a main component. In other words, the (meth)acrylic polymer contains a structural unit derived from an alkyl (meth)acrylate. Alkyl (meth) acrylate is preferably 50% by weight or more in the total monomer components serving as the raw material of the (meth) acrylic polymer, and can be arbitrarily set as the remainder of the monomers other than the alkyl (meth) acrylate. In addition, (meth)acrylate refers to an acrylate and/or a methacrylate.

Examples of the alkyl (meth)acrylate constituting the main skeleton of the (meth)acrylic polymer include linear or branched alkyl groups having 1 to 18 carbon atoms. Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, amyl, hexyl, cyclohexyl, heptyl, 2-ethylhexyl, isooctyl, nonyl, A decyl group, isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, etc. are mentioned. Alkyl (meth)acrylates may be used alone or in combination. It is preferable that the average carbon number of an alkyl group is 3-10.

The (meth)acrylic polymer may contain, in addition to the structural units derived from alkyl (meth)acrylates, structural units derived from copolymerizable monomers capable of being polymerized with alkyl (meth)acrylates. That is, the monomer component used as the raw material of the (meth)acrylic polymer may further contain a copolymerization monomer in addition to the alkyl (meth)acrylate.

As the copolymerization monomer, for example, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amino group-containing monomer, an amide group-containing monomer, a cyclization polymerizable monomer, an epoxy group-containing monomer, a sulfonic acid group-containing monomer, a phosphoric acid group-containing monomer, a polyfunctional acrylate, (meth)acrylic acid esters having an alicyclic hydrocarbon group, (meth)acrylic acid esters having an aromatic hydrocarbon group, vinyl esters, aromatic vinyl compounds, dienes, vinyl ethers, and vinyl chloride. Copolymerization monomers can be used alone or in combination.

Among these copolymerization monomers, preferably, a reactive group-containing monomer containing a reactive group capable of reacting with a crosslinking agent described later is used, and a carboxyl group-containing monomer and a hydroxyl group-containing monomer are more preferable. The reactive group-containing monomer serves as a reaction site with the crosslinking agent when the pressure-sensitive adhesive contains a crosslinking agent described later. Carboxyl group-containing monomers and hydroxyl group-containing monomers are highly reactive with intermolecular cross-linking agents, and therefore are preferably used for improving the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer. In addition, a carboxyl group-containing monomer is preferable in terms of achieving both durability and reworkability, and a hydroxyl group-containing monomer is preferable in terms of improving reworkability. The copolymerization monomer may be used alone or in combination in the raw material monomer of the (meth)acrylic polymer.

A carboxyl group-containing monomer is a compound which contains a carboxyl group in its structure and also contains polymerizable unsaturated double bonds, such as a (meth)acryloyl group and a vinyl group. Examples of the carboxyl group-containing monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Among these, acrylic acid is preferable. The (meth)acrylic polymer may preferably include a structural unit derived from a carboxyl group-containing monomer, more preferably a structural unit derived from (meth)acrylic acid. When the (meth)acrylic polymer contains a structural unit derived from a carboxyl group-containing monomer, the adhesive properties of the pressure-sensitive adhesive layer can be improved.

When using a carboxyl group-containing monomer as a raw material monomer, the content of the carboxyl group-containing monomer is usually 0.01% by weight or more and 10% by weight or less in all monomer components serving as raw materials for the (meth)acrylic polymer.

A hydroxyl group-containing monomer is a compound which contains a hydroxyl group in its structure and also contains a polymerizable unsaturated double bond, such as a (meth)acryloyl group and a vinyl group. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl ( hydroxyalkyl (meth)acrylates such as meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate; (4-hydroxymethylcyclohexyl)-methyl acrylate etc. are mentioned. Among these, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferable, and 4-hydroxybutyl (meth)acrylate is more preferable. The (meth)acrylic polymer is preferably a structural unit derived from a hydroxyl group-containing monomer, more preferably a structural unit derived from 2-hydroxyethyl (meth)acrylate and/or 4-hydroxybutyl (meth)acrylate can include When the (meth)acrylic polymer contains a structural unit derived from a hydroxyl group-containing monomer, the durability of the pressure-sensitive adhesive layer can be improved.

When a hydroxyl group-containing monomer is used as the raw material monomer, the content of the hydroxyl group-containing monomer is usually 0.01% by weight or more and 10% by weight or less in all monomer components serving as raw materials for the (meth)acrylic polymer.

The weight average molecular weight (Mw) of the (meth)acrylic polymer is, for example, 200,000 to 3,000,000, preferably 1,000,000 to 2,500,000, more preferably 1,200,000 to 2,500,000. When the weight average molecular weight (Mw) is within this range, a pressure-sensitive adhesive layer having excellent durability (particularly, heat resistance) can be obtained. When the weight average molecular weight (Mw) exceeds 3,000,000, a rise in viscosity and/or gelation during polymer polymerization may occur.

F-2. cross-linking agent

The pressure sensitive adhesive may contain a crosslinking agent. As the crosslinking agent, an organic type crosslinking agent, a polyfunctional metal chelate or the like can be used. As an organic type crosslinking agent, an isocyanate type crosslinking agent, a peroxide type crosslinking agent, an epoxy type crosslinking agent, and an imine type crosslinking agent are mentioned, for example. A polyfunctional metal chelate is one in which a multivalent metal is bonded covalently or coordinately to an organic compound. When the pressure sensitive adhesive is a radiation curable type, a multifunctional monomer can be used as a crosslinking agent. Crosslinking agents may be used alone or in combination. The crosslinking agent preferably includes an isocyanate-based crosslinking agent and a peroxide-based crosslinking agent.

When blending the crosslinking agent into the pressure-sensitive adhesive, the blending amount of the crosslinking agent is usually 0.01 to 15 parts by weight based on 100 parts by weight of the (meth)acrylic polymer (base polymer). When blending the isocyanate-based crosslinking agent into the pressure-sensitive adhesive, the blending amount of the isocyanate-based crosslinking agent is usually 0.01 part by weight to 15 parts by weight, preferably 1.0 part by weight to 10 parts by weight, more preferably 100 parts by weight of the (meth)acrylic polymer. It is 2.5 parts by weight to 5 parts by weight. When blending the peroxide-based crosslinking agent into the pressure-sensitive adhesive, the blending amount of the peroxide-based crosslinking agent is usually 0.01 to 2 parts by weight, preferably 0.1 to 0.5 parts by weight, based on 100 parts by weight of the (meth)acrylic polymer. When the blending ratio of the crosslinking agent (isocyanate crosslinking agent and peroxide crosslinking agent) is within the above range, the elastic modulus of the pressure-sensitive adhesive layer described later can be smoothly adjusted to a desired range when a reactive group-containing monomer is included in the raw material monomer component of the (meth)acrylic polymer. can

F-3. Silane coupling agent containing a reactive functional group

The pressure sensitive adhesive may contain a silane coupling agent containing a reactive functional group. The reactive functional group-containing silane coupling agent is typically a functional group other than an acid anhydride group. Examples of functional groups other than the acid anhydride group include an epoxy group, a mercapto group, an amino group, an isocyanate group, an isocyanurate group, a vinyl group, a styryl group, an acetacetyl group, a ureido group, a thiourea group, and a (meth)acrylic group. groups, heterocyclic groups, and combinations thereof. The silane coupling agent containing a reactive functional group can be used alone or in combination.

When blending the silane coupling agent containing a reactive functional group into the pressure-sensitive adhesive, the blending amount of the silane coupling agent containing a reactive functional group is usually 0.001 part by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer.

F-4. additive

The pressure-sensitive adhesive may contain a (meth)acrylic oligomer and/or an ionic compound. Moreover, the adhesive may contain additives. Specific examples of additives include powders such as colorants and pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, softeners, antioxidants, antiaging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powder, particulate, and thin materials of Further, within a controllable range, a redox system to which a reducing agent is added may be employed. Moreover, the adhesive may contain the polyether compound which has a reactive group (for example, reactive silyl group). The type, number, combination, content, etc. of additives may be appropriately set according to the purpose. The content of the additive is preferably 5 parts by weight or less, more preferably 3 parts by weight or less, still more preferably 1 part by weight or less, based on 100 parts by weight of the (meth)acrylic polymer.

F-5. Characteristics of adhesive

The storage elastic modulus of the pressure-sensitive adhesive at 23°C and 55% RH is typically 0.05 GPa or more, preferably 0.11 GPa or more, and is typically 0.2 GPa or less, preferably 0.15 GPa or less. In addition, the storage modulus can be measured based on JIS K 7244 using a dynamic viscoelasticity measuring device "ARES" manufactured by Rheometrics. If the modulus of elasticity of the pressure-sensitive adhesive is within this range, the resistance of the optical layered body 1 to local load can be further improved.

G. The first retardation layer

The first retardation layer 7 may be composed of a retardation film having any appropriate optical and/or mechanical properties depending on the purpose. The first retardation layer 7 is located on the side opposite to the viewing side of the polarizing plate 2 . The first retardation layer 7 is typically bonded to the viewing side and the opposite side of the polarizer 21 through an arbitrary appropriate adhesive layer. The first retardation layer 7 may serve as a protective layer on the opposite side of the viewing side of the polarizer 21 .

The thickness of the first retardation layer 7 is preferably 10 μm to 60 μm, more preferably 30 μm to 50 μm.

The in-plane retardation Re (550) of the first retardation layer 7 is preferably 80 nm to 150 nm, more preferably 90 nm to 140 nm, still more preferably 100 nm to 130 nm.

As described above, the first retardation layer 7 preferably has a refractive index characteristic of nx>ny>nz. The Nz coefficient of the first retardation layer 7 is preferably 1.1 to 3.0, more preferably 1.3 to 2.7.

The first retardation layer 7 may be preferably arranged so that its slow axis is substantially parallel to the absorption axis of the polarizer 21 . In this specification, the expressions "substantially parallel" and "approximately parallel" include the case where the angle formed by the two directions is 0°±7°, preferably 0°±5°, and more preferably 0°. It is °±3°. The expressions "substantially orthogonal" and "approximately orthogonal" include the case where the angle formed by the two directions is 90°±7°, preferably 90°±5°, and more preferably 90°±3°. am. In addition, when simply referring to "orthogonal" or "parallel" in this specification, a substantially orthogonal or substantially parallel state may be included.

The absolute value of the photoelastic coefficient of the first retardation layer 7 is preferably 2×10 ^-11 m ² /N or less, more preferably 2.0×10 ^-13 m ² /N to 1.5×10 ^-11 m ² / N, more preferably 1.0×10 ^-12 m ² /N to 1.2×10 ^-11 m ² /N. When the absolute value of the photoelastic coefficient is within this range, phase difference change is unlikely to occur when shrinkage stress occurs during heating. Therefore, by forming the first retardation layer 7 using a resin having such an absolute value of the photoelastic coefficient, heat unevenness can be satisfactorily prevented when the optical laminate 1 is applied to an image display device.

The first retardation layer 7 may exhibit reverse dispersion wavelength characteristics in which the retardation value increases with the wavelength of the measurement light, or may exhibit positive wavelength dispersion characteristics in which the retardation value decreases with the wavelength of the measurement light. A flat wavelength dispersion characteristic that hardly changes even with the wavelength may be exhibited. The first retardation layer 7 preferably exhibits flat wavelength dispersion characteristics. Specifically, Re(450)/Re(550) of the first retardation layer 7 is preferably 0.99 to 1.03, and Re(650)/Re(550) is preferably 0.98 to 1.02. By arranging the λ/2 plate (first retardation layer) and the λ/4 plate (second retardation layer) having flat wavelength dispersion characteristics at a predetermined axis angle, it is possible to obtain characteristics close to ideal reverse wavelength dispersion characteristics, , as a result, very good antireflection properties can be realized.

The first retardation layer 7 may be made of any suitable resin film that can satisfy the above characteristics. Representative examples of such resins include cyclic olefin-based resins, polycarbonate-based resins, cellulose-based resins, polyester-based resins, polyvinyl alcohol-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polystyrene-based resins, Acrylic resins are exemplified. Among them, cyclic olefin resins can be suitably used. The first retardation layer 7 is obtained, for example, by stretching a film formed of the above resin. Details of the stretching method of the cyclic olefin resin and the resin film (method of forming the retardation film) are described in, for example, Japanese Unexamined Patent Publication No. 2015-210459 and Japanese Unexamined Patent Publication No. 2016-105166. The description of this publication is incorporated herein by reference.

H. Second retardation layer

The second retardation layer 8 may be composed of a retardation film having any appropriate optical and/or mechanical properties depending on the purpose. The second retardation layer 8 is located on the side opposite to the viewing side of the first retardation layer 7 . The second retardation layer 8 is typically bonded to the viewing side and the opposite side of the first retardation layer 7 via any appropriate adhesive layer.

The thickness of the second retardation layer 8 is preferably 10 μm to 50 μm, most preferably 20 μm to 40 μm.

The in-plane retardation Re (550) of the second retardation layer 8 is preferably 10 nm to 60 nm, more preferably 20 nm to 50 nm, still more preferably 30 nm to 40 nm.

As described above, the second retardation layer 8 preferably has a refractive index characteristic of nz>nx>ny. The Nz coefficient of the second retardation layer 8 is preferably -10 to -0.1, more preferably -5 to -1.

The second retardation layer 8 may be preferably disposed so that its slow axis is substantially orthogonal to the absorption axis of the polarizer 21 .

The second retardation layer 8 may be made of any suitable resin film that can satisfy the above characteristics. Such a resin may typically be a polymer having negative intrinsic birefringence. A polymer having negative intrinsic birefringence means that the refractive index in the orientation direction becomes relatively small when the polymer is oriented by stretching or the like. Examples of polymers having negative intrinsic birefringence include those in which chemical bonds or functional groups with high polarization anisotropy, such as aromatics and carbonyl groups, are introduced into the side chains of the polymers. Specific examples thereof include modified polyolefin-based resins (for example, modified polyethylene-based resins), acrylic resins, styrene-based resins, maleimide-based resins, and fumaric acid ester-based resins. The second retardation layer 8 can be obtained, for example, by appropriately stretching a film formed of the above resin.

Further, in one embodiment of the present invention, the optical layered body 1 includes the first phase difference layer 7 and the second phase difference layer 8, but the optical layered body includes the first phase difference layer and/or the second phase difference layer 8. It is not necessary to provide a retardation layer.

I. Panel side adhesive layer

The panel-side adhesive layer 9 is located on the side opposite to the viewing side of the second retardation layer 8 . The panel-side pressure-sensitive adhesive layer 9 is typically formed by coating any appropriate pressure-sensitive adhesive onto the second retardation layer 8 . The thickness of the panel side adhesive layer 9 is preferably 1 μm to 60 μm, more preferably 5 μm to 30 μm. Moreover, in one embodiment of this invention, although the optical laminated body 1 is provided with the panel side adhesive layer 9, the optical laminated body does not need to be provided with the panel side adhesive layer.

J. Image display device

The optical layered body described in the above section A to I can be applied to an image display device. Accordingly, one embodiment of the present invention also includes an image display device using such an optical laminate. Representative examples of the image display device include a liquid crystal display device and an organic EL display device. An image display device according to an embodiment of the present invention typically includes the optical laminate described in the above items A to I on the viewing side. An image display device includes an image display panel. The image display panel includes image display cells. Also, an image display device is sometimes referred to as an optical display device, an image display panel is sometimes referred to as an optical display panel, and an image display cell is sometimes referred to as an optical display cell.

(Example)

Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited by these examples. In addition, the measuring method of each characteristic is as follows.

(1) Orange Peel

The optical laminates obtained in Examples and Comparative Examples were cut out to a size of 200 mm x 300 mm and used as test samples. In the test sample, the absorption axis direction (MD direction) of the polarizer was parallel to the width direction (direction orthogonal to the length direction) of the test sample. Next, the test sample was bonded to a black acrylic board with a panel-side pressure-sensitive adhesive layer. Light was incident on the surface of the visual side of the test sample bonded to the acrylic plate using a fluorescent lamp so that the reflection angle was 45° to 70°, and the external appearance (visible side surface) of the test sample was visually observed. The results were evaluated according to the following criteria.

A: Inconspicuous unevenness

B: Noticeable unevenness

C: remarkably conspicuous unevenness

(2) turn test

Optical laminates obtained in Examples and Comparative Examples were cut out to a size of 5 cm x 5 cm to be used as test samples. Next, the test sample was bonded to a glass plate having a thickness of 1.2 mm by means of the panel-side pressure-sensitive adhesive layer. The test sample bonded to the glass plate was placed on the stage of an indenter CMS tester (manufactured by Instron, product name: 5581) equipped with a turning jig. The radius of curvature R of the tip of the turning jig was 500 µm. Under a room temperature (23° C.±3° C.) environment, the test sample on the stage was stabbed with a turning jig with a load of 9 kg. Light leakage when the optical laminate and the standard polarizing plate after the penetration test were arranged so that the polarizer of the optical laminate and the polarizer of the standard polarizing plate were in a crossed Nicols state was visually observed and evaluated according to the following criteria.

A: Light leakage was not confirmed.

B: Light leakage is confirmed to such an extent that it can affect practical use.

C: Light leakage is so remarkable that it is practically unacceptable.

(3) Warpage in a high humidity environment

The optical laminates obtained in Examples and Comparative Examples were cut out to a size of 200 mm × 300 mm and used as visual side samples. In the viewer-side sample, the absorption axis direction (MD direction) of the polarizer was parallel to the width direction (direction orthogonal to the longitudinal direction) of the viewer-side sample. Next, the visual side sample was bonded to the surface of the glass plate with the panel side pressure-sensitive adhesive layer. The glass plate had a size of 210 mm x 310 mm, and the thickness of the glass plate was 550 µm. In addition, the laminate obtained in the production example was cut out to a size of 200 mm x 300 mm and used as a light source side sample. In the light source side sample, the absorption axis direction (MD direction) of the polarizer was parallel to the longitudinal direction of the light source side sample. Next, the light source side sample was bonded to the back surface of the glass plate with an adhesive layer. Thus, a test sample in which the visual side sample, the glass plate, and the light source side sample were laminated was obtained.

Next, the test sample was subjected to autoclave treatment under normal conditions (50°C, 5atm) for 15 minutes, then left still for 48 hours at 23°C and 55% RH, and then left at 65°C and 90% RH for 48 hours. . Then, the shape of the test sample was visually observed and evaluated according to the following criteria.

A: It is a concave shape when shape observation is made with the backlight side polarizing plate (light source side sample) facing down.

B: It is a convex shape when the shape is observed with the backlight-side polarizing plate (light source-side sample) facing downward.

In addition, when the test sample after the high humidity test has a convex shape, the upper visual side sample (optical laminate of Examples and Comparative Examples) is more expanded than the lower light source side sample (laminate of Production Example), and the visual side sample is warped. interpreted as occurring.

On the other hand, when the test sample after the high humidity test has a concave shape, in a high humidity environment, the lower light source side sample (laminated body of Production Example) is more expanded than the upper viewing side sample (optical laminated body of Examples and Comparative Examples). It is interpreted that the curvature of the side sample is suppressed.

[Production Example 1]

[1. A polarizing plate was obtained in the same manner as in "Manufacture of a polarizing plate (polarizer laminate)". Furthermore, an acrylic adhesive (adhesive PSA2 described later) was coated on the surface on the opposite side to the protective layer in the polarizer to form an adhesive layer. The thickness of the pressure-sensitive adhesive layer was 20 μm.

Further, a reflective polarizer film (product name: APF-T35, thickness: 38 μm) manufactured by 3M Co. was bonded to the surface opposite to the polarizer in the protective layer (acrylic resin film) through an acrylic adhesive (adhesive PSA3 described later). . Accordingly, an adhesive layer was formed between the acrylic resin film and the reflective polarizer film. The thickness of the pressure-sensitive adhesive layer was 12 μm.

In accordance with the above, a laminate having a configuration of pressure-sensitive adhesive layer/polarizing plate/pressure-sensitive adhesive layer/reflective polarizer film was obtained.

<Preparation of adhesive PSA2>

99 parts of butyl acrylate, 1.0 part of 4-hydroxybutyl acrylate, and 0.3 part of 2,2'-azobisisobutyronitrile were added together with ethyl acetate to a reaction vessel equipped with a cooling pipe, a nitrogen inlet pipe, a thermometer and a stirring device. After reacting at 60°C for 4 hours under a nitrogen gas stream, ethyl acetate was added to the reaction solution to obtain a solution containing acrylic polymer A2 with a weight average molecular weight of 1,650,000 (solid content concentration: 30% by weight).

Based on 100 parts of the solid content of the obtained acrylic polymer A2 solution, 0.3 part of dibenzoyl peroxide (Nippon Yushi Co., Ltd.: Nyper BMT) and 0.1 part of trimethylolpropanexylene diisocyanate (Mitsui Takeda Chemical Co., Ltd.: Takenate D110N) and 0.2 part of a silane coupling agent (manufactured by Soken Chemical Co., Ltd.: A-100, a silane coupling agent containing an acetacetyl group), to obtain an acrylic pressure-sensitive adhesive PSA2.

<Preparation of adhesive PSA3>

100 parts of butyl acrylate, 5 parts of acrylic acid, 0.1 part of 2-hydroxyethyl acrylate, and 2,2'-azobisisobuty as a polymerization initiator in a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser 0.1 part of ronitrile was introduced together with 100 g of ethyl acetate, nitrogen gas was introduced with gentle stirring, and after nitrogen substitution, the liquid temperature in the flask was maintained at around 55° C., polymerization was carried out for 8 hours, and an acrylic polymer having a weight average molecular weight of 2.2 million A solution containing A3 was obtained.

0.60 part of an isocyanate crosslinking agent (Coronate L, manufactured by Tosoh Co., Ltd.) and 0.20 part of a silane coupling agent (KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) were blended with respect to 100 parts of the solid content of the obtained acrylic polymer A3 solution to obtain an acrylic pressure-sensitive adhesive composition. An acrylic pressure-sensitive adhesive PSA3, which is a solution (solid content: 11% by weight), was obtained.

[Examples 1 to 3]

1. Production of polarizing plate (polarizer laminate)

As the thermoplastic resin substrate, an amorphous isophthalic copolymer polyethylene terephthalate film (thickness: 100 μm) having a long shape and a Tg of about 75° C. was used, and corona treatment was performed on one side of the resin substrate.

Potassium iodide 13 in 100 parts by weight of a PVA-based resin obtained by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetacetyl-modified PVA (manufactured by Nippon Kosei Chemical Industry Co., Ltd., trade name "Gosepima") at a ratio of 9:1 What was added by weight was dissolved in water to prepare a PVA aqueous solution (coating liquid).

A PVA-based resin layer having a thickness of 13 μm was formed by applying the PVA aqueous solution to the corona-treated surface of the resin substrate and drying at 60° C. to prepare a laminate.

The obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) in an oven at 130°C (air assisted stretching treatment).

Next, the laminate was immersed in an insolubilization bath (boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insolubilization treatment).

Then, the dye bath (iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with respect to 100 parts by weight of water) at a solution temperature of 30 ° C. is concentrated so that the single transmittance (Ts) of the polarizer finally obtained becomes a desired value. It was immersed for 60 seconds while adjusting (dyeing treatment).

Then, it was immersed in a crosslinking bath (a boric acid solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) at a solution temperature of 40°C for 30 seconds (crosslinking treatment).

Thereafter, the laminate is immersed in an aqueous solution of boric acid at a liquid temperature of 70 ° C. (boric acid concentration: 4% by weight, potassium iodide concentration: 5% by weight), so that the total draw ratio is 5.5 times in the machine direction (longitudinal direction) between rolls with different circumferential speeds. Uniaxial stretching was performed (underwater stretching treatment).

Thereafter, the laminate was immersed in a washing bath (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with respect to 100 parts by weight of water) at a liquid temperature of 20°C (washing treatment).

Thereafter, while drying in an oven maintained at about 90°C, it was brought into contact with a heating roll made of SUS whose surface temperature was maintained at about 75°C (dry shrinkage treatment).

In this way, a polarizer having a thickness of about 5 µm was formed on the resin substrate.

An acrylic resin film (thickness: 40 μm) having a glutarimide structure as a protective layer was bonded to the surface of the obtained polarizer (surface opposite to the resin substrate) through an ultraviolet curable adhesive. Specifically, the curable adhesive was coated to a total thickness of about 2.0 μm, and bonded using a roll machine. Thereafter, UV rays were irradiated from the side of the acrylic resin film to cure the adhesive. Then, the resin substrate was peeled off to obtain a polarizing plate having a structure of acrylic resin film (protective layer)/polarizer.

2. Anti-see through laminate

As the anti-see-through laminate, a TAC film (product name: HL214, thickness: 42 μm) with a retardation layer manufactured by Fujifilm Co., Ltd. was used.

3. Fabrication of antireflection laminate

As the antireflection laminate, an AR film (AR + HC thickness: 4 µm, base material thickness: 80 µm) manufactured by Dexerials Co., Ltd. was used.

4. Preparation of adhesive

4-1. Preparation of pressure-sensitive adhesive PSA1 used for the first to third pressure-sensitive adhesive layers and the panel-side pressure-sensitive adhesive layer

A monomer mixture containing 94.9 parts of butyl acrylate, 0.1 part of 4-hydroxybutyl acrylate, and 5.0 parts of acrylic acid was charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet pipe, and a condenser. Further, 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was added together with 100 parts of ethyl acetate with respect to 100 parts of this monomer mixture, nitrogen gas was introduced with gentle stirring, and after nitrogen substitution, the inside of the flask The polymerization reaction was performed for 8 hours while maintaining the liquid temperature at around 55°C, and a solution of acrylic polymer A1 having a weight average molecular weight (Mw) of 2,200,000 and Mw/Mn = 3.0 was prepared.

Trimethylolpropane/tolylene diisocyanate adduct (manufactured by Tosoh Corporation, trade name "Coronate L") 3 parts, peroxide crosslinking agent (benzoyl peroxide) 0.2 part, epoxy group-containing silane coupling agent ( 0.075 part of Shin-Etsu Chemical Co., Ltd., trade name "KBM-403") and 0.5 part of a polyether compound having a reactive silyl group (manufactured by Kaneka, trade name "Silyl SAT10") were blended to obtain an adhesive PSA1. The storage modulus of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer was measured according to JIS K 7244 using a dynamic viscoelasticity measuring device "ARES" manufactured by Rheometrics. The storage modulus of PSA1 at 23°C and 55% RH was 0.11 GPa.

5. Fabrication of the optical stack

On the protective layer of the polarizing plate, the anti-see through laminate was bonded via the pressure-sensitive adhesive PSA1. Specifically, the pressure-sensitive adhesive PSA1 was applied to the surface of the protective layer on the visual side to form a first pressure-sensitive adhesive layer having a thickness shown in Table 1, and then the anti-bleaching layer of the anti-bleaching laminate was brought into contact with the first pressure-sensitive adhesive layer, The anti-see through laminate was bonded to the polarizing plate through the first pressure-sensitive adhesive layer. At this time, the slow axis of the anti-reflective layer (orientation-fixed layer of liquid crystal compound) was adjusted to form an angle of 45° with respect to the absorption axis of the polarizer.

Next, an acrylic resin film (thickness: 40 μm) having a glutarimide structure as a reinforcing layer was bonded on the first base material of the anti-see through laminate via the pressure-sensitive adhesive PSA1. Specifically, PSA1 was coated on the surface of the first base material on the visual side to form a second pressure sensitive adhesive layer having a thickness shown in Table 1, and the reinforcing layer was brought into contact with the second pressure sensitive adhesive layer to bond to the anti-see through laminate.

Next, the antireflection laminate was bonded on the reinforcing layer via the pressure-sensitive adhesive PSA1. Specifically, the adhesive PSA1 was applied to the visual side surface of the reinforcing layer to form a third adhesive layer having a thickness shown in Table 1, then the second substrate of the antireflection laminate was brought into contact with the second adhesive layer, The antireflection laminate was bonded to the reinforcing layer via the third pressure sensitive adhesive layer.

Further, a cyclic olefin-based film (refractive index characteristic: nx>ny>nz, in-plane retardation: 116 nm) as a first retardation layer was bonded to the surface opposite to the protective layer in the polarizer through an ultraviolet curable adhesive. At this time, the slow axis of the first retardation layer was adjusted to form an angle of 0° with respect to the absorption axis of the polarizer. After that, a modified polyethylene film (refractive index characteristic: nz>nx> ny, in-plane retardation: 35 nm) was bonded as a second retardation layer to the surface opposite to the polarizer in the first retardation layer through an ultraviolet curable adhesive. At this time, the slow axis of the second retardation layer was adjusted to form an angle of 90° with respect to the absorption axis of the polarizer.

Next, PSA1 was applied to the surface opposite to the first phase difference layer in the second phase difference layer to form a panel side pressure sensitive adhesive layer having a thickness shown in Table 1.

According to the above, the configuration of the antireflection laminate / third adhesive layer / reinforcing layer / second adhesive layer / anti-see through laminate / first adhesive layer / polarizing plate / first retardation layer / second retardation layer / panel-side adhesive layer An optical laminate having Table 1 shows the thickness of each layer included in the optical laminate, the total thickness of the optical laminate, and the total thickness of the anti-see through laminate, the reinforcing layer, and the antireflection laminate. Further, the optical layered body was subjected to the orange peel, puncture test (light leakage), and evaluation of warpage in a high-humidity environment. The results are shown in Table 2 together with the total thickness of the anti-see through laminate, the reinforcing layer, and the antireflection laminate, and the thickness of each pressure-sensitive adhesive layer.

[Comparative Example 1]

1st adhesive layer / polarizing plate / 1st retardation layer in the same manner as in Example 2 except that only the first adhesive layer was formed on the visual side rather than the polarizing plate, and the thickness of the panel-side adhesive layer was changed to the value shown in Table 1. An optical laminate having a configuration of /second retardation layer/panel-side pressure-sensitive adhesive layer was obtained.

[Comparative Example 2]

In the same manner as in Comparative Example 1, except that only the first pressure sensitive adhesive layer and the anti-bleaching laminate were formed on the visual side rather than the polarizing plate, the anti-bleaching laminate/first pressure sensitive adhesive layer/polarizing plate/first retardation layer/second retardation layer/panel side An optical laminate having a configuration of an adhesive layer was obtained.

[Comparative Example 3]

Anti-reflective laminate / agent An optical laminate having a configuration of two pressure-sensitive adhesive layers / anti-see through laminate / first pressure-sensitive adhesive layer / polarizing plate / first retardation layer / second phase difference layer / panel-side pressure-sensitive adhesive layer was obtained.

[Comparative Example 4]

Antireflection laminate/second adhesive layer/transparent An optical laminate having a structure of anti-laminated body/first pressure sensitive adhesive layer/polarizing plate/first retardation layer/second retardation layer/panel side pressure sensitive adhesive layer was obtained.

[Comparative Example 5]

reflective Prevention laminate / 4th pressure sensitive adhesive layer / 2nd reinforcing layer / 3rd pressure sensitive adhesive layer / reinforcement layer / 2nd pressure sensitive adhesive layer / anti-see through laminate / 1st pressure sensitive adhesive layer / polarizing plate / 1st retardation layer / 2nd retardation layer / panel side adhesive An optical laminate having a layered structure was obtained. In addition, the second reinforcing layer was an acrylic resin film (thickness: 40 µm) having a glutarimide structure. In addition, the 4th adhesive layer was formed by coating the adhesive PSA1 to the visual side surface of the 2nd reinforcing layer so that it might become the thickness shown in Table 1.

[Comparative Example 6]

Antireflection laminate/third adhesive layer/reinforcement layer/second in the same manner as in Example 2 except that the thickness of the reinforcing layer was changed to 80 μm and the thickness of the panel-side adhesive layer was changed to the values shown in Table 1. An optical laminate having a configuration of: pressure-sensitive adhesive layer / anti-see through laminate / first pressure-sensitive adhesive layer / polarizing plate / first retardation layer / second phase difference layer / panel-side pressure-sensitive adhesive layer was obtained.

[Comparative Example 7]

The anti-bleach laminate was changed from a TAC film with a retardation layer manufactured by Fujifilm Co., Ltd. (product name: HL214, thickness: 42 µm) to a polycarbonate-based anti-bleach film (thickness: 82 µm) manufactured by Nitto Denko Co., Ltd. And, except that the thickness of the panel-side adhesive layer was changed to the value shown in Table 1, in the same manner as in Example 2, antireflection laminate / third adhesive layer / reinforcing layer / second adhesive layer / anti-see through laminate / agent An optical laminate having a configuration of one pressure sensitive adhesive layer/polarizing plate/first retardation layer/second retardation layer/panel side pressure sensitive adhesive layer was obtained.

[evaluation]

As is clear from Table 2, the thickness of each pressure-sensitive adhesive layer is set to 17 μm or less, a reinforcing layer is formed between the anti-see through laminate and the anti-reflection laminate, and the total of the anti-see through laminate, the reinforcing layer, and the anti-reflection laminate is formed. By setting the thickness to 200 μm or less, it can be seen that an optical laminate that satisfies suppression of orange peel, resistance to local load, and suppression of curvature in a high-humidity environment can be obtained with a good balance.

The optical layered body of the present invention can be suitably used for an image display device (typically, a liquid crystal display device or an organic EL display device).

1 optical stack
2 polarizer
21 polarizer
22 protective layer
3 anti-see through laminate
31 first registration
32 anti-see-through layer
4 antireflection laminate
41 second article
42 hard coat layer
43 antireflection layer
5 reinforcement layer
61 first adhesive layer
62 second adhesive layer
63 third adhesive layer
7 1st retardation layer
8 2nd retardation layer

Claims (7)

a polarizer;
A first optical functional body bonded to the visual side of the polarizing plate through a first pressure-sensitive adhesive layer;
A reinforcing layer bonded to the visual side of the first optical functional body through a second pressure-sensitive adhesive layer;
A second optical functional body bonded through a third pressure-sensitive adhesive layer is provided on the visual side of the reinforcing layer,
The thickness of each of the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the third pressure-sensitive adhesive layer is 17 μm or less,
The optical laminate of claim 1 , wherein a total sum of a thickness of the first optical functional element, a thickness of the reinforcing layer, and a thickness of the second optical functional element is 200 µm or less. According to claim 1,
The first optical functional element is an anti-see through laminate,
The anti-see through laminate
An anti-see through layer in contact with the first pressure-sensitive adhesive layer;
An optical laminate comprising a first substrate disposed on a visual side of the anti-see through layer and in contact with the second pressure-sensitive adhesive layer. According to claim 1 or 2,
The second optical functional body is an antireflection laminate,
The anti-reflection laminate
A second substrate in contact with the third pressure-sensitive adhesive layer;
A hard coat layer disposed on the visual side of the second substrate;
An optical laminate comprising an antireflection layer disposed on a viewing side of the hard coat layer. According to claim 3,
The antireflection layer is located on the outermost surface of the optical laminate,
The moisture permeability of the antireflection layer is 0.1 g / mm ² or less of the optical laminate. According to claim 1 or 2,
The polarizer
with a polarizer,
An optical laminate comprising a protective layer disposed on a viewing side of the polarizer and in contact with the first pressure-sensitive adhesive layer. According to claim 5,
The optical laminate having a thickness of the polarizer is 10 μm or less. According to claim 1 or 2,
Further comprising a first retardation layer and a second retardation layer disposed in order from the polarizing plate side on the opposite side of the viewing side of the polarizing plate,
The first retardation layer exhibits refractive index characteristics of nx>ny>nz,
The optical laminate wherein the second retardation layer exhibits a refractive index characteristic of nz>nx>ny.

Images