JP7130789B2 - optical laminate - Google Patents

Description

The present invention relates to an optical laminate capable of double-sided transfer, a method for producing the optical laminate, an elliptically polarizing plate including the optical laminate, and a flexible display material.

A circularly polarizing plate including a polarizing film and a retardation film is widely used in a flat panel display (FPD) such as an organic EL display. As such a circularly polarizing plate, there is known an optical laminate in which a polarizing film or a retardation film is an optically anisotropic layer comprising a coating layer obtained by coating a polymerizable liquid crystal compound on a substrate and polymerizing it. (Patent Documents 1 to 3).

JP 2020-56834 A JP 2019-91088 A JP 2020-13164 A

The optical layered body as disclosed in the above patent document is produced by transferring an optically anisotropic layer formed on a base material to a transfer material, that is, by peeling off the base material and removing an adhesive layer or the like. It can be incorporated into a display device or the like by laminating it to a transfer material through an intermediate layer.
However, an optical layered body incorporated into a display device or the like by transferring the two outer layer surfaces appearing by peeling the base material from such an optical layered body may cause zipping or floating at the separation interface during transfer. It has been clarified by studies by the present inventors that these phenomena can lead to deterioration of the optical performance of the optical layered body after transfer.

An object of the present invention is to provide an optical layered body that suppresses occurrence of zipping and lifting at a peeling interface when transferred to a transfer medium, and that can be easily transferred to any transfer medium.

The inventors of the present invention have completed the present invention as a result of intensive studies to solve the above problems. That is, the present invention includes the following aspects.
[1] An optical laminate comprising a first substrate, an alignment film, a polarizing film, an adhesive layer, a retardation film and a second substrate in this order,
The polarizing film and the retardation film are each a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound,
The peeling force F1 when peeling the first substrate from the optical layered body and the peeling force F2 when peeling the second substrate from the optical layered body are expressed by the following formulas (1), (2) and (3). ):
0.02 (N/25mm)≤F1≤0.30 (N/25mm) (1)
0.02 (N/25mm)≤F2≤0.30 (N/25mm) (2)
0.02 (N/25mm)≦|F1−F2| (3)
An optical laminate that satisfies
[2] The optical layered body according to [1] above, which has a release force adjusting layer on at least one of the polarizing film-side surface of the first substrate and the retardation film-side surface of the second substrate.
[3] The optical laminate according to [2] above, wherein the peel force adjusting layer is a layer containing a silane compound or a hard coat layer.
[4] The optical layered body according to any one of [1] to [3], wherein the first substrate has a thickness of 20 μm or more and 100 μm or less.
[5] The optical layered body according to any one of [1] to [4], wherein the second substrate has a thickness of 20 μm or more and 100 μm or less.
[6] Any one of the above [1] to [5], wherein the first substrate is a resin film composed of at least one selected from cellulose resins, cyclic olefin resins and polyethylene terephthalate resins. optical laminate.
[7] Any one of [1] to [6] above, wherein the second substrate is a resin film composed of at least one selected from cellulose resins, cyclic olefin resins and polyethylene terephthalate resins. optical laminate.
[8] The optical laminate according to any one of [1] to [7] above, wherein the polarizing film is a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound and a dichroic dye.
[9] Retardation film represented by formula (4):
120 nm≦Re(550)≦170 nm (4)
[Wherein, Re (λ) represents the in-plane retardation value of the retardation film at a wavelength of λnm]
The optical laminate according to any one of [1] to [8], which satisfies
[10] The optical layered product according to [9], further comprising a liquid crystal cured film that is a positive C plate.
[11] The optical laminate according to any one of [1] to [10] above, wherein the total thickness of the polarizing film, adhesive layer and retardation film is 20 μm or less.
[12] A step of producing a long optical layered body roll obtained by winding the optical layered body according to any one of [1] to [11] into a roll, and
From the elongated optical layered body roll, the substrate having a smaller peeling force when peeled from the optical layered body out of the first base material and the second base material constituting the optical layered body is continuously peeled off. A method for producing a long optical film, comprising a first peeling step.
[13] A lamination step of laminating a third substrate via an adhesive layer to the surface on which the substrate peeled in the first peeling step was adjacent, and
The method for producing a long optical film according to [12] above, further comprising a second peeling step of peeling off the first substrate or the second substrate that has not been peeled off in the first peeling step.
[14] An elliptically polarizing plate comprising the optical laminate according to any one of [1] to [11].
[15] A flexible display material comprising the optical laminate according to any one of [1] to [11].

According to the present invention, it is possible to provide an optical layered body that can be easily transferred to an arbitrary transfer-receiving material by suppressing the occurrence of zipping and lifting at the separation interface when transferring to the transfer-receiving material.

1 is a schematic cross-sectional view showing an example of the layer structure of an optical layered body of the present invention; FIG. 1 is a schematic cross-sectional view showing an example of the layer structure of an optical layered body of the present invention; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail. It should be noted that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the gist of the present invention.

The optical layered body of the present invention comprises a first substrate, an alignment film, a polarizing film, an adhesive layer, a retardation film and a second substrate in this order. An example of the layer structure of the optical layered body of the present invention will be described below with reference to FIGS. 1 and 2, but the layered body of the present invention is not limited to these embodiments.

The optical laminate 11 shown in FIG. 1 comprises a first substrate 1, an alignment film 2, a polarizing film 3, an adhesive layer 4, a retardation film 5, an alignment film 6 and a second substrate 7, which are laminated in this order. It becomes In the optical layered body 11 shown in FIG. 1, the first base material 1 and the second base material 7 are each releasable, and the releasable first and second base materials are separated from the optical layered body 11. Then, the laminate structure 12 composed of the alignment film 2, the polarizing film 3, the adhesive layer 4, the retardation film 5, and the alignment film 6 is transferred to a transfer target such as a (flexible) OLED or a (flexible) touch panel. can do.

In a preferred embodiment of the present invention, the optical laminate of the present invention has a release force adjusting layer on at least one of the polarizing film-side surface of the first substrate and the retardation film-side surface of the second substrate. include. The optical layered body 12 shown in FIG. 2 has a release force adjusting layer 8 between the first substrate 1 and the alignment film 2, and a release force adjusting layer 9 between the second substrate 7 and the alignment film 6. have. In one embodiment of the present invention, only the release force adjusting layer is arranged between the first substrate and the alignment film, and in another embodiment, between the second substrate and the retardation film, Only the peel force adjusting layer and the alignment film are arranged.

The optical laminate of the present invention does not affect the effects of the present invention in addition to the first base material, alignment film, polarizing film, adhesive layer, retardation film, second base material and release force adjusting layer. As far as possible, it may be configured to include other layers. Other layers include, for example, an alignment film for forming a retardation film, a second retardation film, an adhesive layer other than the adhesive layer between the polarizing film and the retardation film, and a resin layer having UV absorbability. etc.

In the optical layered body of the present invention, the peeling force F1 when peeling the first substrate from the optical layered body and the peeling force F2 when peeling the second substrate from the optical layered body are expressed by the formula (1 ), (2) and (3):
0.02 (N/25mm)≤F1≤0.30 (N/25mm) (1)
0.02 (N/25mm)≤F2≤0.30 (N/25mm) (2)
0.02 (N/25mm)≦|F1−F2| (3)
meet.
The peeling force F1 and the peeling force F2 are peeling forces within the ranges specified by the above formula (1) or (2), and the peeling force F1 and the peeling force F2 are in the above formula (3) When the relationship is expressed, it is possible to suppress the occurrence of zipping and lifting at the separation interface when the two outer layer surfaces appearing by peeling the base material from the optical layered body are transferred and incorporated into a display device or the like. , an effect of suppressing deterioration of optical performance due to transfer can be expected.

In the present invention, the peel force F1 is preferably less than 0.30 N/25 mm, more preferably 0.25 N/25 mm or less, even more preferably 0.15 N/25 mm or less. When the upper limit of the peeling force F1 is within the above range, the first substrate can be easily peeled off from the optical layered body, and the peeling force is within an effective range in relation to the peeling force F2 in order to suppress the occurrence of zipping and floating. Easy to control F1. Also, the peel force F1 is preferably 0.04 N/25 mm or more, more preferably 0.06 N/25 mm or more, and still more preferably 0.08 N/25 mm or more. When the peeling force F1 is equal to or higher than the above lower limit, while ensuring easy peelability when peeling the first base material from the optical layered body, unintended first base material before transfer to incorporate the layered body into a display device or the like. Peeling can be suppressed.

In the present invention, the peel force F2 is preferably less than 0.30 N/25 mm, more preferably 0.25 N/25 mm or less, even more preferably 0.15 N/25 mm or less. When the upper limit of the peeling force F2 is within the above range, the second substrate can be easily peeled off from the optical layered body, and the peeling force is within an effective range in relation to the peeling force F1 to suppress the occurrence of zipping and floating. Easy to control F2. Also, the peel force F2 is preferably 0.04 N/25 mm or more, more preferably 0.06 N/25 mm or more, and still more preferably 0.08 N/25 mm or more. When the peeling force F2 is equal to or higher than the above lower limit, the second base material is unintentionally removed before the transfer to incorporate the laminate into a display device or the like while ensuring easy peelability when peeling the second base material from the optical laminate. Peeling can be suppressed.

When the peeling force F1 and the peeling force F2 satisfy the relationship represented by the formula (3), the adhesion force between the first substrate in the optical layered body and the adhesion force between the second substrate in the optical layered body A moderate strength relationship arises in Therefore, when the above relationship is satisfied, it is possible to suppress the occurrence of zipping at the time of transfer and floating at the separation interface, and easily separate the first base material and the second base material from the optical layered body in a desired order. As a result, the effect of suppressing the deterioration of the optical performance of the optical layered body due to the transfer can be expected. In particular, the absolute value of F1-F2 in the present invention is preferably 0.03 N/25 mm or more, more preferably 0.04 N/25 mm or more, from the viewpoint of being excellent in the effect of suppressing the occurrence of floating at the separation interface. In addition, from the viewpoint of enhancing the effect of suppressing the occurrence of zipping, the upper limit of the absolute value of F1-F2 is usually 0.3 N/25 mm or less, preferably 0.2 N/25 mm or less, more preferably 0.08 N/25 mm. It is below. The value of F1-F2 can be controlled by adjusting the release force F1 and the release force F2 respectively. In addition, the peeling force F1 and the peeling force F2 are usually designed so that the peeling force on the side of the substrate that is peeled first is smaller than the peeling force on the side of the substrate that is peeled later.

The peel forces F1 and F2 are the substrates of the optical layered body to be measured on the opposite side of the substrate for which the peel force is measured (for example, the second substrate when measuring F1, and the first substrate when measuring F2). Material) is peeled off from the optical laminate of the test piece, and the first substrate or second substrate for measuring the peel force is fixed by bonding it to a glass plate with an adhesive. It is a value measured as a peel force required for peeling. The peel force can be measured according to the 90° peel test method specified in JIS K 6854-1:1999. A detailed method for measuring the peeling forces F1 and F2 will be described in Examples below.

The peel force F1 and the peel force F2 are determined, for example, by the structure and thickness of the layers adjacent to the first substrate and the second substrate, the types and thicknesses of the first substrate and the second substrate, and the thickness of the first substrate. , surface treatment of the second substrate and/or layers adjacent to these substrates, and the like. For example, the surface of the first substrate and / or the second substrate as described later is subjected to a modification treatment, or the layer adjacent to the first substrate or the second substrate is used to control the peel force within a desired range. It is possible to control the peeling force of the first substrate or the second substrate from the optical layered body by providing a layer (hereinafter referred to as a "peeling force adjusting layer").

Hereinafter, each configuration of the optical layered body of the present invention will be described in detail.

[First base material and second base material]
The first base material and the second base material are layers detachably laminated on the optical layered body. The first base material and the second base material may be configured so that the peel forces F1 and F2 satisfy the above formulas (1), (2) and (3). A conventionally known resin film or the like in the field can be used. Examples of resins constituting the first substrate and the second substrate include polyolefins such as polyethylene, polypropylene and norbornene-based polymers; cyclic olefin-based resins; polyvinyl alcohol; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate and the like. polymethacrylates; polyacrylates; cellulosic resins such as triacetylcellulose, diacetylcellulose and cellulose acetate propionate; polycarbonates; polysulfones; polyethersulfones; plastics. Among them, at least one selected from cellulose resins, cyclic olefin resins, and polyethylene terephthalate resins is preferable from the viewpoint of smoothness and quality as a coating substrate. These may be used alone or in combination of two or more. Such a resin can be formed into a resin film by known means such as a solvent casting method and a melt extrusion method. In addition, in this specification, when simply describing as a "substrate", a 1st base material and a 2nd base material shall be included as this "substrate."

In order to impart desired releasability and adhesiveness to the film surface and to facilitate control of the peeling forces F1 and F2 within the desired range, corona treatment, plasma treatment, and flame treatment are applied depending on the configuration of adjacent layers, etc. A modification treatment may be applied to the base material surface by, for example. In the optical layered body of the present invention, when the surface modification treatment is applied to the first substrate and the second substrate, the treatment methods may be the same or different.

The thickness of the first base material and the second base material may be appropriately determined according to the structure of the first base material and the second base material, the structure of the layer adjacent to the base material, and the like. From the viewpoint of film surface quality, each layer is preferably 20 μm or more, more preferably 30 μm or more, still more preferably 40 μm or more, and preferably 120 μm or less, more preferably 100 μm or less, further preferably 80 μm or less. In the optical layered body of the present invention, the thickness of the first substrate and the thickness of the second substrate may be the same or different.
The thickness of the base material can be measured by a laser microscope, a film thickness meter, or the like, and the thickness of each layer or film, such as a polarizing film and a retardation film, constituting the optical laminate can be measured in the same way.

[Release force adjustment layer]
The optical laminate of the present invention preferably has a release force adjusting layer on at least one of the polarizing film-side surface of the first substrate and the retardation film-side surface of the second substrate. By providing the release force adjusting layer, it is easy to secure a desired release force over the entire length of even a long optical layered body, and the effect of suppressing zipping and lifting at the peel interface is likely to be improved. When the optical laminate of the present invention includes a release force adjusting layer, the release force adjusting layer is usually arranged adjacent to the polarizing film side surface of the first substrate or the retardation film side surface of the second substrate. be done.

In the present invention, the peel force adjusting layer is a layer formed on the polarizing film side surface of the first substrate and/or the retardation film side surface of the second substrate, and the optical laminate is separated from the first substrate. and/or a layer having a function of controlling the peeling force F2 when peeling the second substrate from the optical layered body. The peel force adjusting layer may be a single layer or a multilayer of two or more layers. When the peel force adjusting layer is composed of two or more layers made of different components, it may be easy to control the peel force F1 or the peel force F2 within a desired range. It may be advantageous in that a desired peeling force can be more stably secured over the entire length.
In addition, the peeling force F1 and/or the peeling force F2 in the optical layered body of the present invention can be controlled by subjecting the substrate surface to corona treatment, plasma treatment, or the like as described above. "Adjustment layer" is a layer formed independently on the polarizing film side surface of the first substrate or on the retardation film side surface of the second substrate, for example, the first substrate, the second substrate When the material and/or the surface of the layer adjacent to these substrates is surface-modified by corona treatment, plasma treatment, or the like, such a modified surface is not included in the "release force adjusting layer."

The release force adjusting layer is, for example, on the surface of the resin film serving as the substrate, a release force adjusting layer containing a component capable of adjusting the adhesion of the substrate to the surface adjacent to the substrate via the release force adjusting layer. It can be formed by applying a layer-forming composition. As the peel force adjusting layer, conventionally known materials in the relevant field can be used as long as the desired peel force can be secured. Examples of the composition for forming the release force adjusting layer that can form the release force adjusting layer in the present invention include, for example, a solution containing a silane compound; a solution containing silica powder; a curable resin composition; Compositions containing release materials such as alkyl-based materials and fatty acid amide-based materials are included. Among them, from the viewpoint of easily forming a layer capable of imparting a desired peeling force, the peeling force adjusting layer preferably contains at least one layer selected from a layer containing a silane compound and a hard coat layer. In this specification, the hard coat layer means a cured resin layer that has higher surface smoothness than the adjacent base material and that can be peeled off from the base material.

The layer containing a silane compound that can constitute the peel force adjusting layer is a layer formed containing a silane compound, as long as the desired peel force F1 and/or peel force F2 can be secured in the optical layered body. It can be formed from materials known in the art.
Silane compounds include, for example, silicon polymers such as polysilane, silicone resins such as silicone oil and silicone resin, silicone oligomers, organic and inorganic silane compounds such as silsessiloxane and alkoxysilane, more specifically silane cups. Examples include nonionic compounds containing Si element such as ring agents. These silane compounds may be used singly or in combination of two or more. Among them, silane coupling agents are preferred.

The silane coupling agent is a silane compound having at least one functional group selected from the group consisting of a vinyl group, an amino group, a ureido group, a mercapto group, a (meth)acryloyl group, an isocyanate group, an imidazole group and an epoxy group. and more preferably a Si element-containing compound having at least one functional group and at least one alkoxysilyl group or silanol group. Vinyl groups, amino groups, ureido groups, mercapto groups, (meth)acryloyl groups, isocyanate groups, imidazole groups, and epoxy groups have polarity. It is possible to control the adhesion with the layer laminated via the layer, and it becomes easy to control the peeling force F1 and/or the peeling force F2 within a desired range. From this point of view, the silane coupling agent is preferably a silane coupling agent having an alkoxysilyl group and the at least one functional group. In addition, the functional group may have an appropriate substituent or protective group in order to control the reactivity of the silane coupling agent.

Specific examples of the silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, 3-glycidoxypropyltri methoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-acryloyloxypropyltri methoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, and 3-glycidoxypropylethoxydimethylsilane.

Further, commercially available silane coupling agents include, for example, KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001, KBM-1003, KBE-1003, KBM-303, KBM-402, KBM-403 , KBE-402, KBE-403, KBM-1403, KBM-502, KBM-503, KBE-502, KBE-503, KBM-5103, KBM-602, KBM-603, KBM-903, KBE-903, KBE - Silane coupling agents from Shin-Etsu Chemical Co., Ltd. such as 9103, KBM-573, KBM-575, KBM-9659, KBE-585, KBM-802, KBM-803, KBE-846, and KBE-9007 is mentioned.

A layer containing a silane compound that functions as a peel force adjusting layer can be formed, for example, from a silane compound-containing solution obtained by mixing and dissolving a silane compound in an appropriate solvent.

The solvent used for the silane compound-containing solution can be appropriately selected according to the solubility of the silane compound used. Specific examples include water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, alcohol solvents such as propylene glycol monomethyl ether, ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone. , propylene glycol methyl ether acetate, ethyl lactate and other ester solvents, acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, methyl isobutyl ketone and other ketone solvents, pentane, hexane, heptane and other aliphatic hydrocarbon solvents, toluene , aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile, ether solvents such as tetrahydrofuran and dimethoxyethane, and chlorinated hydrocarbon solvents such as chloroform and chlorobenzene. These solvents can be used alone or in combination of two or more.

The content of the silane compound in the silane compound-containing solution is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, relative to the total mass of the silane compound-containing solution, from the viewpoint of easy control of the peeling force. , more preferably 0.25% by mass or more. The content of the silane compound is preferably 30% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less, relative to the total mass of the silane compound-containing solution.

The silane compound-containing solution may contain components other than the silane compound and the solvent as long as it can impart the desired peeling force to the first substrate and/or the second substrate, but in one embodiment of the present invention, The silane compound-containing solution consists essentially of the silane compound and the solvent.

The layer containing a silane compound that functions as a release force adjusting layer is formed by, for example, applying a silane compound-containing solution to the surface of the first substrate or second substrate on which the release force adjusting layer is to be formed, followed by drying and removing the solvent. It can be formed by

Examples of the method of applying the silane compound-containing solution to the surface on which the release force adjusting layer is to be formed include spin coating, extrusion, gravure coating, die coating, bar coating, applicator method, and the like. Well-known methods, such as printing methods, such as a flexography method, are mentioned.

Examples of the drying method for removing the solvent contained in the coating film obtained from the silane compound-containing solution include natural drying, ventilation drying, heat drying and reduced pressure drying. Conditions such as drying temperature and drying time can be appropriately determined according to the composition of the silane compound-containing solution, the material of the surface (substrate) on which the release force adjusting layer is to be formed, and the like.

The thickness of the layer containing a silane compound that functions as a peel force adjusting layer is usually 10 nm to 1000 nm, preferably 10 nm to 500 nm, more preferably 30 nm to 300 nm.

The hard coat layer constituting the release force adjusting layer in the optical layered body of the present invention is made of a material known in the art as long as the desired release force F1 and/or release force F2 can be secured in the optical layered body. Examples thereof include a layer formed from a resin composition containing a water-soluble polymer and a cured resin layer formed from a resin composition containing an active energy ray-curable or thermosetting resin component. Among them, a cured resin layer formed from a resin composition containing an active energy ray-curable resin component is preferable, and a cured resin layer formed from a resin composition containing an active energy ray-curable resin component and a cross-linking agent is more preferable. preferable.

In the present invention, the resin composition constituting the hard coat layer usually contains a resin component (polymer). Examples of resin components include resin components (polymers) such as (meth)acrylic polymers, urethane polymers, polyester polymers, silicone polymers, polyvinyl ether polymers, and polyvinyl alcohol polymers. These resin components may be used individually by 1 type, or may be used in combination of 2 or more type. Among them, (meth)acrylic polymers and urethane polymers are preferred, and urethane acrylate polymers are more preferred.

Examples of (meth)acrylic polymers include (meth)acrylic acid esters such as butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Examples include polymers or copolymers containing one or more monomers.

Examples of urethane-based polymers include polyurethanes such as ether-based polyurethanes, ester-based polyurethanes, and carbonate-based polyurethanes, urethane (meth)acrylates, and acrylic-urethane copolymers obtained by copolymerizing alkyl (meth)acrylates. . When the hard coat layer contains a urethane-based polymer, flexibility is likely to be increased, making it easier to obtain an optical laminate suitable as a flexible display material. polyurethanes such as ether-based polyurethanes, ester-based polyurethanes, and carbonate-based polyurethanes; acrylic-urethane copolymers obtained by copolymerizing urethane (meth)acrylates and alkyl (meth)acrylates;

The content of the resin component in the resin composition can be appropriately determined according to the type of resin component used, etc., but is preferably 50 parts by mass or more, more preferably 50 parts by mass or more, based on 100 parts by mass of the solid content of the resin composition. is 60 parts by mass or more, more preferably 70 parts by mass or more, and is preferably 100 parts by mass or less, more preferably 95 parts by mass or less, and still more preferably 90 parts by mass or less.

The resin composition forming the hard coat layer may contain a cross-linking agent. As the cross-linking agent, a cross-linking agent commonly used in the relevant field can be used, and can be appropriately selected according to the resin component constituting the hard coat layer, the structure of the layer adjacent to the hard coat layer, and the like. Examples of cross-linking agents include methylol compounds, polyfunctional thiol compounds, and polyfunctional (meth)acrylates. These may be used alone or in combination of two or more. Among them, at least one selected from the group consisting of a methylol compound, a polyfunctional thiol compound and a polyfunctional (meth)acrylate compound is preferable, and it is more preferable to contain a polyfunctional (meth)acrylate compound.

Specific examples of methylol compounds include 1,3,4,6-tetrakis(methoxymethyl)glycoluril, 1,3,4,6-tetrakis(butoxymethyl)glycoluril, 1,3,4,6- Tetrakis(hydroxymethyl)glycoluril, 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, 1,1,3,3-tetrakis(methoxymethyl)urea, 1 alkoxymethylated glycolurils such as ,3-bis(hydroxymethyl)-4,5-dihydroxy-2-imidazolinone, and 1,3-bis(methoxymethyl)-4,5-dimethoxy-2-imidazolinone; alkoxymethylated benzoguanamines such as methoxymethylbenzoguanamine and tetrabutoxymethylbenzoguanamine; and alkoxymethylated melamines such as hexamethoxymethylmelamine and hexabutoxymethylmelamine. A compound obtained by condensing a melamine compound, a urea compound, a glycoluril compound and a benzoguanamine compound in which a hydrogen atom of such an amino group is substituted with a methylol group or an alkoxymethyl group may also be used.

You may use a commercial item as a methylol compound. Commercial products of alkoxymethylated glycoluril include glycoluril compounds manufactured by Nippon Cytec Industries Co., Ltd. (trade names: Cymel 1170, Powderlink 1174), methylated urea resin (trade name: UFR65), and butylated urea resin (trade name: UFR65). UFR300, U-VAN10S60, U-VAN10R, U-VAN11HV), etc., Dainippon Ink and Chemicals Co., Ltd. urea / formaldehyde resin (high condensation type, trade name Beccamin J-300S, Beccamin P-955, Beccamin N ), and butylated urea resins (trade names: Beccamin P-138, Beccamin P-196-M, Beccamin G-1850). Commercial products of alkoxymethylated benzoguanamine include Nippon Cytec Industries Co., Ltd. (trade name Cymel 1123), Sanwa Chemical Co., Ltd. (trade names Nikalac BX-4000, Nikalac BX-37, Nikalac BL-60, Nikalac BX-55H), butylated benzoguanamine resins manufactured by Dainippon Ink and Chemicals Co., Ltd. (trade names Super Beccamin TD-126, Super Beccamin 15-594), and the like. Commercially available products of alkoxymethylated melamine include methoxymethyl type melamine compounds (trade names: Cymel 300, Cymel 301, Cymel 303, Cymel 350) manufactured by Nippon Cytec Industries Co., Ltd., and butoxymethyl type melamine compounds (trade name: Mycoat 506, Mycoat 508), methoxymethyl type melamine compounds manufactured by Sanwa Chemical Co., Ltd. (trade names: Nikalac MW-30, Nikalac MW-22, Nikalac MW-11, Nikalac MS-001, Nikalac MX-002, Nikalac MX -730, Nicalac MX-750, Nicalac MX-035), and butoxymethyl type melamine compounds (trade names: Nicalac MX-45, Nicalac MX-410, Nicalac MX-302), butyl manufactured by Dainippon Ink & Chemicals Co., Ltd. Modified melamine resin (Super Beckamin J-820-60, Super Beckamin L-109-65, Super Beckamin L-117-60, Super Beckamin L-127-60, Super Beckamin 13-548, Super Beckamin G-821-60, Super Beckamin L-110-60, Super Beckamin L-125-60, Super Beckamin L-166-60B), methylated melamine resin (trade name Super Beckamin L-105-60) etc. In addition, water-based melamine resins such as Watersol S-695 and S-683-IM (trade names) manufactured by Dainippon Ink and Chemicals, Inc., and Beccamin P-198 (trade name) may also be used. Furthermore, commercial products of the melamine compound include Cymel 303 (trade name, manufactured by Nippon Cytec Industries Co., Ltd.). ) made).

A polyfunctional thiol compound means a compound having two or more thiol groups in one molecule. Polyfunctional thiol compounds include, for example, hexanedithiol, decanedithiol, 1,4-dimethylmercaptobenzene, butanediol bisthiopropionate, butanediol bisthioglycolate, ethylene glycol bisthioglycolate, trimethylolpropane tristhio Glycolate, butanediol bisthiopropionate, trimethylolpropane tristhiopropionate, trimethylolpropane tristhioglycolate, pentaerythritol tetrakisthiopropionate, pentaerythritol tetrakisthioglycolate, trishydroxyethyl tristhiopropio pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryloxy)butane and the like.

A polyfunctional (meth)acrylate compound means a compound having two or more (meth)acryloyloxy groups in one molecule. In this specification, "(meth)acrylate" means "acrylate" or "methacrylate", and "(meth)acryloyl" similarly means "acryloyl" or "methacryloyl".
Specific examples of polyfunctional (meth)acrylates include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetradecaethylene glycol di (meth) acrylate, dipropylene glycol di (meth)acrylate, 1,3-butylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tetra(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6 -hexanediol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate and the like.

When a polyfunctional (meth)acrylate compound is used as a cross-linking agent, the number of (meth)acryloyl groups is preferably 4 or more, more preferably 6 or more, and preferably 10 or less, more preferably 8 or less. When the number of (meth)acryloyl groups in the polyfunctional (meth)acrylate compound is at least the above lower limit, the cross-linking density of the hard coat layer is increased, and not only does it function as a release force adjusting layer, but it also functions as a polarizing film and retardation film. It can also have a function as a protective layer for the film.

The polyfunctional (meth)acrylate compound can adjust the crosslink density of the hard coat layer by controlling the molecular weight between crosslink points and the number of crosslink points of the compound. More specifically, the smaller the molecular weight between cross-linking points, the higher the cross-linking density, and the higher the number of cross-linking points, the denser the cross-linking density. It can increase the heat resistance of the body.

In one embodiment of the present invention, the polyfunctional (meth)acrylate compound has a branched structure, from the viewpoint of controlling the cross-linking density and forming a hard coat layer that can function as a protective layer for a polarizing film or a retardation film. The number of atoms in the chain (sometimes referred to as a linking chain) connecting the branch point closest to the (meth)acryloyl group in the branched structure and the (meth)acryloyl group is preferably 3 or less, and 2 or less. is more preferable. When the number of atoms is equal to or less than the above upper limit, the crosslink density of the hard coat layer is increased, and an improvement in the heat resistance of the optical laminate can be expected. Here, when there are a plurality of the linked chains, it is sufficient that at least one linked chain satisfies the above range of the number of atoms, and from the viewpoint of improving heat resistance, all the linked chains should satisfy the above range of the number of atoms. is preferred.

The content of the cross-linking agent in the resin composition forming the hard coat layer can be appropriately determined according to the type of the cross-linking agent used, etc., but is preferably 50 mass parts per 100 mass parts of the solid content of the resin composition. parts or more, more preferably 60 parts by mass or more, still more preferably 70 parts by mass or more, and preferably 100 parts by mass or less, more preferably 95 parts by mass or less, and even more preferably 90 parts by mass or less. When the content of the cross-linking agent is within the above range, it is easy to control the peel force F1 and/or the peel force F2 within the desired range.

The resin composition forming the hard coat layer may contain a polymerization initiator from the viewpoint of improving curability. The polymerization initiator may be appropriately selected from known photopolymerization initiators and thermal polymerization initiators so as to initiate curing of the curable compound (resin) contained in the resin composition, but from the viewpoint of improving productivity. It is preferable to use a photopolymerization initiator from Examples of photopolymerization initiators include acetophenone, 3-methylacetophenone, benzyldimethylketal, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, 2-methyl-1-[4 Acetophenone initiators such as -(methylthio)phenyl]-2-morpholinopropan-1-one and 2-hydroxy-2-methyl-1-phenylpropan-1-one; benzophenone, 4-chlorobenzophenone and 4,4' -benzophenone initiators such as diaminobenzophenone; alkylphenone initiators such as 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone; benzoin propyl ether and benzoin ethyl benzoin ether-based initiators such as ethers; thioxanthone-based initiators such as 4-isopropylthioxanthone; acylphosphine oxide-based initiators such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; Camphorquinone, benzaldehyde, anthraquinone, and the like. These may be used alone or in combination of two or more.

The amount of the polymerization initiator in the resin composition forming the hard coat layer is preferably 1 part by mass or more, more preferably 2 parts by mass or more, relative to 100 parts by mass of the solid content of the resin composition. is 10 parts by mass or less, more preferably 8 parts by mass or less. When the content of the polymerization initiator is within the above range, sufficient curability can be obtained without affecting the optical performance of the optical layered body.

In addition, the resin composition forming the hard coat layer may optionally contain other additives other than the polymerization initiator, such as ultraviolet absorbers, antistatic agents, stabilizers, antioxidants, colorants, and surface conditioners. It may contain agents and the like. Other additives may be used alone or in combination of two or more. When other additives are included, the content thereof is preferably about 0.1 to 20% by mass based on the total mass of the solid content of the resin composition.

In order to improve coatability, the viscosity may be adjusted by adding a solvent to the resin composition forming the hard coat layer. Any solvent can be used as long as it can dissolve various components constituting the resin composition, and the same solvents as those exemplified as the solvent used for the silane compound-containing solution can be used.

The type and content of the solvent are appropriately selected according to the type and content of the components contained in the resin composition, the shape, the coating method, the thickness of the hard coat layer, and the like. It is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, still more preferably 7 parts by mass or more, and preferably 1000 parts by mass or less, more preferably 100 parts by mass, based on 100 parts by mass of the solid content of the composition. It is not more than 50 parts by mass, more preferably not more than 50 parts by mass.

A hard coat layer that functions as a release force adjusting layer is formed by, for example, coating a resin composition on the surface of a substrate or other release force adjusting layer on which a hard coat layer is to be formed, and curing the resin composition. can get. As a method of applying the resin composition, the same method as the method of applying the silane compound-containing solution onto the substrate or the like can be employed.

The method for curing the resin composition may be appropriately determined according to the composition of the resin composition. For example, when the resin composition is an active energy ray-curable composition, the hard coat layer can be obtained by curing the curable component contained in the composition by irradiating it with an active energy ray. Active energy rays include, for example, visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays and γ-rays. Among them, ultraviolet light is preferable because the progress of the reaction can be easily controlled and a photopolymerization device widely used in the field can be used.

Examples of the light source of the active energy ray include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excimer lasers, and wavelength ranges. LED light sources, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, etc., which emit light in the range of 380 to 440 nm can be used.

The UV irradiation intensity is usually 10 to 3,000 mW/cm ² . The ultraviolet irradiation intensity is preferably in the wavelength range effective for activation of the polymerization initiator. The light irradiation time is usually 0.1 second to 10 minutes, preferably 1 second to 5 minutes, more preferably 5 seconds to 3 minutes, still more preferably 10 seconds to 1 minute. When irradiated once or multiple times with such an irradiation intensity of ultraviolet rays, the cumulative amount of light is 10 to 3,000 mJ/cm ² , preferably 50 to 2,000 mJ/cm ² , more preferably 100 to 1,000 mJ/cm. ² .

The thickness of the hard coat layer that functions as a release force adjusting layer is usually 0.1 to 10 μm, preferably 0.2 μm or more, more preferably 0.3 μm or more, and preferably 5 μm or less, more preferably. is 3 μm or less.

The configuration of the release force adjusting layer may be appropriately determined according to the type of the first base material or the second base material, the relationship with the layer adjacent to these base materials via the release force adjusting layer, and the like. For example, by using a resin film made of polyethylene terephthalate as the resin film constituting the base material and forming a release force adjustment layer made of an acrylic silane coupling agent as the release force adjustment layer adjacent thereto, Adhesion can be improved as compared with the case where the peel force adjusting layer is not formed. For each of the first base material and the second base material, the type of the resin film constituting the base material and the type or presence or absence of the release force adjusting layer adjacent thereto are determined (via the release force adjusting layer) with the base material. By appropriately selecting and combining in relation to the structure / type of the layer to be laminated, it becomes easier to realize the peeling forces F1 and F2 that satisfy the above formulas (1) to (3), and when peeling the base material The effect of suppressing the occurrence of zipping and floating at the peeling interface can be improved.

In one embodiment of the present invention, at least one of the peel force adjusting layer disposed on the first substrate side or the second substrate side is preferably composed of a layer containing a silane compound or a hard coat layer. , It is more preferable that both the release force adjusting layers disposed on the first substrate side and the second substrate side are composed of a layer containing a silane compound or a hard coat layer, and the first substrate side or the second substrate side It is more preferable that at least one of the peel force adjusting layers arranged on the substrate side is composed of a layer containing a silane compound and a hard coat layer. Further, when the peel force adjusting layer includes a layer containing a silane compound and a hard coat layer, the configuration between the first substrate and the polarizing film, or between the second substrate and the retardation film, It is preferable that the layer containing the silane compound is arranged on the substrate side and the hard coat layer is arranged on the polarizing film or retardation film side, and it is more preferable that the layer containing the silane compound and the hard coat layer are adjacent to each other. When the peel force adjusting layer has the above structure, it has a high inhibitory effect on the occurrence of zipping at the time of transfer and floating at the peeling interface, and also has an excellent protective function for the polarizing film and the retardation film, and has high optical properties in the optical laminate. characteristics can be expected.

In the present invention, when the first substrate and the second substrate constitute the optical layered body with the release force adjusting layer interposed therebetween, the release force adjusting layer disposed on the first substrate side and the second substrate side It is preferable that the arranged peel force adjusting layers have different configurations.
The peel force adjusting layers having different configurations are different in composition of the peel force adjusting layer, thickness of the peel force adjusting layer, combination of each layer when the peel force adjusting layer consists of two or more layers, lamination order of each layer, etc. Say. In particular, when the first substrate and the second substrate are made of the same resin material, the release force adjustment layer arranged on the first substrate side and the release force adjustment layer arranged on the second substrate side are different from each other, a sufficient difference tends to occur between the peeling force F1 and the peeling force F2. The two substrates can be easily peeled off in the desired order. Further, if necessary, the surface of the release force adjusting layer on which the alignment film or the like is formed may be further subjected to surface treatment such as corona treatment.

The thickness of the peel force adjusting layer (the total thickness of all layers when consisting of multiple layers) can be appropriately determined according to the layer structure of the peel force adjusting layer, but is preferably 0.1 μm or more, more preferably 0.2 μm or more. , more preferably 0.3 μm or more, preferably 10 μm or less, more preferably 5 μm or less, and still more preferably 3 μm or less.

[Polarizing film]
In the present invention, the polarizing film is a film (layer) having a polarizing function and contains a dichroic dye, which is a dye having absorption anisotropy. From the viewpoint of making the optical layered body thinner and ensuring bending resistance suitable for flexible display materials, the polarizing film in the optical layered body of the present invention is a coating layer, and at least one liquid crystal compound is added. It is preferably a cured film formed from a polymerizable liquid crystal composition (hereinafter also referred to as “polarizing film-forming composition”) containing, preferably, a polymerizable liquid crystal compound and a dichroic dye.

The polymerizable liquid crystal compound (hereinafter also referred to as "polymerizable liquid crystal compound (A)") contained in the composition for forming the polarizing film (polarizer) of the present invention has at least one polymerizable group. is a compound. Here, the term "polymerizable group" refers to a group that can participate in a polymerization reaction due to an active radical generated from a polymerization initiator, an acid, or the like. Examples of the polymerizable group possessed by the polymerizable liquid crystal compound (A) include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, (meth)acryloyl group, oxiranyl group, and oxetanyl group. etc. Among them, a radically polymerizable group is preferred, a (meth)acryloyl group, a vinyl group, and a vinyloxy group are more preferred, and a (meth)acryloyl group is even more preferred. When the polymerizable liquid crystal compound forming the polarizing film has the same functional group (polymerizable group) as the compound forming the alignment film for forming the polarizing film described later, for example, a (meth)acryloyl group, The compatibility between the alignment film and the polarizing film is high, and excellent adhesion between the layers can be exhibited.

In the present invention, the polymerizable liquid crystal compound (A) is preferably a compound exhibiting smectic liquid crystallinity. By using a polymerizable liquid crystal compound exhibiting smectic liquid crystallinity, a polarizing film with a high degree of alignment order can be formed. From the viewpoint of realizing a higher degree of alignment order, the liquid crystal state exhibited by the polymerizable liquid crystal compound (A) is more preferably a high-order smectic phase (high-order smectic liquid crystal state). Here, the higher order smectic phase includes smectic B phase, smectic D phase, smectic E phase, smectic F phase, smectic G phase, smectic H phase, smectic I phase, smectic J phase, smectic K phase and smectic L phase. Among these, smectic B phase, smectic F phase and smectic I phase are more preferable. Thermotropic liquid crystals or lyotropic liquid crystals may be used as liquid crystals, but thermotropic liquid crystals are preferred because they allow precise film thickness control. Moreover, the polymerizable liquid crystal compound (A) may be a monomer, but may be an oligomer or polymer in which a polymerizable group is polymerized.

The polymerizable liquid crystal compound (A) is not particularly limited as long as it is a liquid crystal compound having at least one polymerizable group, and known polymerizable liquid crystal compounds can be used, but compounds exhibiting smectic liquid crystallinity are preferred. Examples of such a polymerizable liquid crystal compound include compounds represented by the following formula (A1) (hereinafter sometimes referred to as "polymerizable liquid crystal compound (A1)").
U ¹ -V ¹ -W ¹ -(X ¹ -Y ¹ ) _n -X ² -W ² -V ² -U ² (A1)
[In the formula (A1),
X ¹ and X ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group, wherein the divalent aromatic group or divalent alicyclic hydrocarbon A hydrogen atom contained in the group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group or a nitro group. A carbon atom constituting the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom. However, at least one of X ¹ and X ² is an optionally substituted 1,4-phenylene group or an optionally substituted cyclohexane-1,4-diyl group.
Y ¹ is a single bond or a divalent linking group.
n is 1 to 3, and when n is 2 or more, multiple X ^1s may be the same or different. X ² may be the same as or different from any or all of the plurality of X ¹ 's. Moreover, when n is 2 or more, the plurality of Y ¹ may be the same or different. From the viewpoint of liquid crystallinity, n is preferably 2 or more.
U1 represents ^a hydrogen atom or a polymerizable group.
^U2 represents a polymerizable group.
W ¹ and W ² are each independently a single bond or a divalent linking group.
V ¹ and V ² each independently represent an optionally substituted alkanediyl group having 1 to 20 carbon atoms, and —CH ₂ — constituting the alkanediyl group is —O—, -CO-, -S- or NH- may be substituted. ]

In the polymerizable liquid crystal compound (A1), X ¹ and X ² are each independently preferably a 1,4-phenylene group optionally having a substituent, or a 1,4-phenylene group optionally having a substituent, or cyclohexane-1,4-diyl group, and at least one of X ¹ and X ² is a 1,4-phenylene group optionally having a substituent, or a 1,4-phenylene group optionally having a substituent cyclohexane-1,4-diyl group, preferably trans-cyclohexane-1,4-diyl group. Optionally substituted 1,4-phenylene group or optionally substituted cyclohexane-1,4-diyl group may have a methyl group, ethyl and alkyl groups having 1 to 4 carbon atoms such as butyl group, cyano group and halogen atoms such as chlorine atom and fluorine atom. It is preferably unsubstituted.

Further, the polymerizable liquid crystal compound (A1) is represented by the formula (A1-1) in the formula (A1):
-(X ¹ -Y ¹ ) _n -X ² - (A1-1)
[In the formula, X ¹ , Y ¹ , X ² and n each have the same meaning as above. ]
[hereinafter, also referred to as partial structure (A1-1)] has an asymmetric structure, because it facilitates smectic liquid crystallinity.
Examples of the polymerizable liquid crystal compound (A1) in which the partial structure ⁽ A1-1) is ^an asymmetric structure include, for example, a polymerizable liquid crystal compound (A1 ). Also, a compound in which n is 2, two Y ^1s have the same structure, two X ^1s have the same structure, and one X ² has a different structure from these two X ^1s Polymerizable liquid crystal compound (A1), X ¹ bonded to W ¹ of two X ¹ has a different structure from the other X ¹ and X ² , and the other X ¹ and X ² have the same structure A polymerizable liquid crystal compound (A1) is also included. Furthermore, a compound in which n is 3, three Y ^1s have the same structure as each other, and any one of the three X ^1s and one X ² has a different structure from all the other three. liquid crystal compound (A1).

Y ¹ is -CH ₂ CH ₂ -, -CH ₂ O-, -CH ₂ CH ₂ O-, -COO-, -OCOO-, a single bond, -N=N-, -CR ^a =CR ^b -, -C≡C-, -CR ^a =N- or -CO-NR ^a - are preferred. R ^a and R ^b each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Y ¹ is more preferably —CH ₂ CH ₂ —, —COO—, or a single bond, and when there are multiple Y ^1s , Y ¹ bonded to X ² is —CH ₂ CH ₂ — or CH ₂ O— is more preferred. When X ¹ and X ² all have the same structure, it is preferred that there are two or more Y ¹ with different binding modes. When ^a plurality of Y1's with different bonding methods exist, the structure is asymmetrical, and smectic liquid crystallinity tends to occur.

^U2 is a polymerizable group. U ¹ is a hydrogen atom or a polymerizable group, preferably a polymerizable group. Both U ¹ and U ² are preferably polymerizable groups, and preferably both are radically polymerizable groups. Examples of the polymerizable group include the same groups as those exemplified above as the polymerizable group possessed by the polymerizable liquid crystal compound (A). The polymerizable group represented by U ¹ and the polymerizable group represented by U ² may be different from each other, but are preferably groups of the same type, and at least one of U ¹ and U ² is (meta) It is preferably an acryloyl group, and more preferably both are (meth)acryloyl groups. The polymerizable group may be in a polymerized state or in an unpolymerized state, preferably in an unpolymerized state.

The alkanediyl groups represented by V ¹ and V ² include methylene, ethylene, propane-1,3-diyl, butane-1,3-diyl, butane-1,4-diyl, pentane- 1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, decane-1,10-diyl group, tetradecane-1,14-diyl and icosane-1,20-diyl groups. V ¹ and V ² are preferably alkanediyl groups having 2 to 12 carbon atoms, more preferably alkanediyl groups having 6 to 12 carbon atoms.

Examples of the substituent optionally possessed by the alkanediyl group include a cyano group and a halogen atom. is more preferred.

W ¹ and W ² are each independently preferably a single bond, -O-, -S-, -COO- or -OCOO-, more preferably a single bond or -O-.

The polymerizable liquid crystal compound (A) is not particularly limited as long as it is a polymerizable liquid crystal compound having at least one polymerizable group, and known polymerizable liquid crystal compounds can be used. Preferably, as a structure that tends to exhibit smectic liquid crystallinity, it is preferable to have an asymmetric molecular structure in the molecular structure, specifically polymerizable having the following partial structures (Aa) to (Ai) A polymerizable liquid crystal compound that is a liquid crystal compound and exhibits smectic liquid crystallinity is more preferable. It is more preferable to have a partial structure of (Aa), (Ab) or (Ac) from the viewpoint of easily exhibiting high-order smectic liquid crystallinity. In (Aa) to (Ai) below, * represents a bond (single bond).

Specific examples of the polymerizable liquid crystal compound (A) include compounds represented by formulas (A-1) to (A-25). When the polymerizable liquid crystal compound (A) has a cyclohexane-1,4-diyl group, the cyclohexane-1,4-diyl group is preferably a trans form.

Among these, formula (A-2), formula (A-3), formula (A-4), formula (A-5), formula (A-6), formula (A-7), formula (A- 8), at least one selected from the group consisting of compounds represented by formula (A-13), formula (A-14), formula (A-15), formula (A-16) and formula (A-17) Seeds are preferred. As the polymerizable liquid crystal compound (A), one type may be used alone, or two or more types may be used in combination.

The polymerizable liquid crystal compound (A) is described, for example, in Lub et al., Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996), or a known method described in Japanese Patent No. 4,719,156.

In the present invention, the composition for forming a polarizing film may contain a polymerizable liquid crystal compound other than the polymerizable liquid crystal compound (A). The ratio of the polymerizable liquid crystal compound (A) to the total mass of all the polymerizable liquid crystal compounds contained in the composition is preferably 51% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass. % or more.

When the polarizing film-forming composition contains two or more polymerizable liquid crystal compounds (A), at least one of them may be the polymerizable liquid crystal compound (A1), and all of them may be polymerizable liquid crystal compounds (A1 ). By combining a plurality of polymerizable liquid crystal compounds, it may be possible to temporarily maintain liquid crystallinity even at temperatures below the liquid crystal-crystal phase transition temperature.

The content of the polymerizable liquid crystal compound in the polarizing film-forming composition is preferably 40 to 99.9% by mass, more preferably 60 to 99% by mass, based on the solid content of the polarizing film-forming composition. Yes, more preferably 70 to 99% by mass. When the content of the polymerizable liquid crystal compound is within the above range, the orientation of the polymerizable liquid crystal compound tends to be high.

In the present invention, the polarizing film forming composition for forming the polarizing film contains a dichroic dye. Here, the term "dichroic dye" means a dye having different absorbance in the long-axis direction and the short-axis direction of the molecule. The dichroic dye that can be used in the present invention is not particularly limited as long as it has the above properties, and may be a dye or a pigment. Also, two or more dyes or pigments may be used in combination, or a dye and a pigment may be used in combination. Moreover, the dichroic dye may have polymerizability or may have liquid crystallinity.

Dichroic dyes preferably have a maximum absorption wavelength (λ _MAX ) in the range of 300 to 700 nm. Examples of such dichroic dyes include acridine dyes, oxazine dyes, cyanine dyes, naphthalene dyes, azo dyes and anthraquinone dyes.

Examples of azo dyes include monoazo dyes, bisazo dyes, trisazo dyes, tetrakis azo dyes and stilbene azo dyes, and preferred are bisazo dyes and trisazo dyes. (I)”).
K ¹ (-N=N-K ² ) _p -N=N-K ³ (I)
[In formula (I), K ¹ and K ³ are, independently of each other, a phenyl group optionally having substituent(s), a naphthyl group optionally having substituent(s), It represents a phenyl benzoic acid ester group or a monovalent heterocyclic group which may have a substituent. K ² is a p-phenylene group optionally having substituents, a naphthalene-1,4-diyl group optionally having substituents, 4,4′- optionally having substituents represents a stilbenylene group or an optionally substituted divalent heterocyclic group; p represents an integer from 0 to 4; When p is an integer of 2 or more, a plurality of K2 may be the same or different. -N=N-bonds may be replaced with -C=C-, -COO-, -NHCO- and -N=CH-bonds within the range of absorption in the visible region. ]

Examples of monovalent heterocyclic groups include groups obtained by removing one hydrogen atom from heterocyclic compounds such as quinoline, thiazole, benzothiazole, thienothiazole, imidazole, benzimidazole, oxazole, and benzoxazole. The divalent heterocyclic group includes a group obtained by removing two hydrogen atoms from the above heterocyclic compound.

Phenyl group, naphthyl group, phenyl benzoic acid ester group and monovalent heterocyclic group for K ¹ and K ³ , and p-phenylene group, naphthalene-1,4-diyl group and 4,4'-stilbenylene group for K ² And the substituent optionally possessed by the divalent heterocyclic group include an alkyl group having 1 to 20 carbon atoms, an alkyl group having a polymerizable group and having 1 to 20 carbon atoms, an alkenyl group having 1 to 4 carbon atoms; a methoxy group; , ethoxy group, alkoxy group having 1 to 20 carbon atoms such as butoxy group; alkoxy group having 1 to 20 carbon atoms having a polymerizable group; fluorinated alkyl group having 1 to 4 carbon atoms such as trifluoromethyl group; cyano group a nitro group; a halogen atom; an amino group, a diethylamino group, a substituted or unsubstituted amino group such as a pyrrolidino group (a substituted amino group is an amino group having one or two alkyl groups having 1 to 6 carbon atoms, a polymerizable means an amino group having one or two alkyl groups of 1 to 6 carbon atoms having a An unsubstituted amino group is —NH _2. ) and the like. In addition, a (meth)acryloyl group, a (meth)acryloyloxy group, etc. are mentioned as said polymerizable group.

［式（Ｉ－１）～（Ｉ－８）中、
Ｂ ^１ ～Ｂ _３０ は、互いに独立して、水素原子、炭素数１～６のアルキル基、炭素数１～６のアルケニル基、炭素数１～４のアルコキシ基、シアノ基、ニトロ基、置換または無置換のアミノ基（置換アミノ基および無置換アミノ基の定義は前記のとおり）、塩素原子またはトリフルオロメチル基を表わす。
ｎ１～ｎ４は、互いに独立に０～３の整数を表わす。
ｎ１が２以上である場合、複数のＢ２は互いに同一でも異なっていてもよく、
ｎ２が２以上である場合、複数のＢ６は互いに同一でも異なっていてもよく、
ｎ３が２以上である場合、複数のＢ９は互いに同一でも異なっていてもよく、
ｎ４が２以上である場合、複数のＢ１４は互いに同一でも異なっていてもよい。］ Among compounds (I), compounds represented by any one of the following formulas (I-1) to (I-8) are preferred.

[In the formulas (I-1) to (I-8),
B ¹ to B ₃₀ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, a nitro group, substituted or represents an unsubstituted amino group (the definitions of substituted amino group and unsubstituted amino group are as described above), chlorine atom or trifluoromethyl group;
n1 to n4 each independently represents an integer of 0 to 3;
When n1 is 2 or more, a plurality of B2 may be the same or different,
When n2 is 2 or more, the plurality of B6 may be the same or different,
When n3 is 2 or more, multiple B9 may be the same or different,
When n4 is 2 or more, the plurality of B14 may be the same or different. ]

［式（Ｉ－９）中、
Ｒ ^１ ～Ｒ ^８ は、互いに独立して、水素原子、－Ｒ ^ｘ 、－ＮＨ _２ 、－ＮＨＲ ^ｘ 、－ＮＲ ^ｘ _２ 、－ＳＲ ^ｘ またはハロゲン原子を表わす。
Ｒ ^ｘ は、炭素数１～４のアルキル基または炭素数６～１２のアリール基を表わす。］ As the anthraquinone dye, a compound represented by formula (I-9) is preferable.

[In the formula (I-9),
R ¹ to R ⁸ independently represent a hydrogen atom, —R ^x , —NH ₂ , —NHR ^x , —NR ^x ₂ , —SR ^x or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

［式（Ｉ－８）中、
Ｒ ^９ ～Ｒ ^１５ は、互いに独立して、水素原子、－Ｒ _ｘ 、－ＮＨ _２ 、－ＮＨＲ ^ｘ 、－ＮＲ ^ｘ _２ 、－ＳＲ ^ｘ またはハロゲン原子を表わす。
Ｒ ^ｘ は、炭素数１～４のアルキル基または炭素数６～１２のアリール基を表わす。］ As the oxazone dye, a compound represented by formula (I-10) is preferable.

[In the formula (I-8),
R ⁹ to R ¹⁵ each independently represent a hydrogen atom, —R _x , —NH ₂ , —NHR ^x , —NR ^x ₂ , —SR ^x or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]

［式（Ｉ－１１）中、
Ｒ ^１６ ～Ｒ ^２３ は、互いに独立して、水素原子、－Ｒ ^ｘ 、－ＮＨ _２ 、－ＮＨＲ ^ｘ 、－ＮＲ ^ｘ _２ 、－ＳＲ ^ｘ またはハロゲン原子を表わす。
Ｒ ^ｘ は、炭素数１～４のアルキル基または炭素数６～１２のアリール基を表わす。］
式（Ｉ－９）、式（Ｉ－１０）および式（Ｉ－１１）において、Ｒ ^ｘ の炭素数１～６のアルキル基としては、メチル基、エチル基、プロピル基、ブチル基、ペンチル基およびヘキシル基等が挙げられ、炭素数６～１２のアリール基としては、フェニル基、トルイル基、キシリル基およびナフチル基等が挙げられる。 As the acridine dye, a compound represented by formula (I-11) is preferable.

[In the formula (I-11),
R ¹⁶ to R ²³ each independently represent a hydrogen atom, —R ^x , —NH ₂ , —NHR ^x , —NR ^x ₂ , —SR ^x or a halogen atom.
R ^x represents an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 12 carbon atoms. ]
In formula (I-9), formula (I-10) and formula (I-11), the alkyl group having 1 to 6 carbon atoms for R ^x includes a methyl group, an ethyl group, a propyl group, a butyl group and a pentyl group. and hexyl group, and the aryl group having 6 to 12 carbon atoms includes phenyl group, toluyl group, xylyl group, naphthyl group and the like.

［式（Ｉ－１２）中、
Ｄ ^１ およびＤ ^２ は、互いに独立に、式（Ｉ－１２ａ）～式（Ｉ－１２ｄ）のいずれかで表される基を表わす。

ｎ５は１～３の整数を表わす。］

［式（Ｉ－１３）中、
Ｄ ^３ およびＤ ^４ は、互いに独立に、式（Ｉ－１３ａ）～式（１－１３ｈ）のいずれかで表される基を表わす。

ｎ６は１～３の整数を表わす。］ As the cyanine dye, a compound represented by formula (I-12) and a compound represented by formula (I-13) are preferable.

[In the formula (I-12),
D ¹ and D ² each independently represent a group represented by any one of formulas (I-12a) to (I-12d).

n5 represents an integer of 1-3. ]

[In the formula (I-13),
D ³ and D ⁴ each independently represent a group represented by any one of formulas (I-13a) to (1-13h).

n6 represents an integer of 1-3. ]

Among these dichroic dyes, azo dyes have high linearity and are suitable for producing a polarizing film having excellent polarizing performance. Therefore, in one embodiment of the present invention, the dichroic dye contained in the polarizing film forming composition for forming the polarizing film is preferably an azo dye.

In the present invention, the weight average molecular weight of the dichroic dye is usually 300-2000, preferably 400-1000.

In one embodiment of the present invention, the dichroic dye contained in the polarizing film-forming composition for forming the polarizing film is preferably hydrophobic. When the dichroic dye is hydrophobic, the compatibility between the dichroic dye and the polymerizable liquid crystal compound is improved, the dichroic dye and the polymerizable liquid crystal compound form a uniform phase state, and the degree of orientational order is high. can be obtained. In the present invention, the hydrophobic dichroic dye means a dye having a solubility of 1 g or less in 100 g of water at 25°C.

The content of the dichroic dye in the composition for forming a polarizing film can be appropriately determined according to the type of the dichroic dye used, etc., but is preferably from 0.1 to 0.1 with respect to 100 parts by mass of the polymerizable liquid crystal compound. It is 50 parts by mass, more preferably 0.1 to 20 parts by mass, still more preferably 0.1 to 12 parts by mass. When the content of the dichroic dye is within the above range, the alignment of the polymerizable liquid crystal compound is less likely to be disturbed, and a polarizing film having a high degree of alignment order can be obtained.

In the present invention, the polarizing film forming composition for forming the polarizing film may contain a polymerization initiator. The polymerization initiator is a compound capable of initiating the polymerization reaction of the polymerizable liquid crystal compound, and is preferably a photopolymerization initiator because it can initiate the polymerization reaction under lower temperature conditions. Specifically, photopolymerization initiators capable of generating active radicals or acids by the action of light may be mentioned, and among these, photopolymerization initiators capable of generating radicals by the action of light are preferred. A polymerization initiator can be used individually or in combination of 2 or more types.

As the photopolymerization initiator, known photopolymerization initiators can be used. For example, photopolymerization initiators that generate active radicals include self-cleavage photopolymerization initiators and hydrogen abstraction photopolymerization initiators. There is
Self-cleavage photopolymerization initiators include self-cleavage benzoin compounds, acetophenone compounds, hydroxyacetophenone compounds, α-aminoacetophenone compounds, oxime ester compounds, acylphosphine oxide compounds, and azo compounds. Available. In addition, as a hydrogen abstraction type photopolymerization initiator, hydrogen abstraction type benzophenone compounds, benzoin ether compounds, benzyl ketal compounds, dibenzosuberone compounds, anthraquinone compounds, xanthone compounds, thioxanthone compounds, and halogenoacetophenone compounds. compounds, dialkoxyacetophenone-based compounds, halogenobisimidazole-based compounds, halogenotriazine-based compounds, triazine-based compounds, and the like can be used.

As photopolymerization initiators that generate acid, iodonium salts, sulfonium salts, and the like can be used.

Among these, a reaction at a low temperature is preferable from the viewpoint of preventing dissolution of the dye, and a self-cleavage photopolymerization initiator is preferable from the viewpoint of reaction efficiency at a low temperature. compounds and oxime ester compounds are preferred.

Specific examples of photopolymerization initiators include the following.
Benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether;
2-hydroxy-2-methyl-1-phenylpropan-1-one, 1,2-diphenyl-2,2-dimethoxyethan-1-one, 2-hydroxy-2-methyl-1-[4-(2- Hydroxyacetophenones such as hydroxyethoxy)phenyl]propan-1-one, oligomers of 1-hydroxycyclohexylphenyl ketone and 2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propan-1-one system compound;
α-Aminoacetophenones such as 2-methyl-2-morpholino-1-(4-methylthiophenyl)propan-1-one and 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one system compound;
1,2-octanedione, 1-[4-(phenylthio)-,2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3 -Oxime ester compounds such as yl]-, 1-(O-acetyloxime);
Acylphosphine oxide compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide;
benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyldiphenylsulfide, 3,3′,4,4′-tetra(tert-butylperoxycarbonyl)benzophenone and 2,4, Benzophenone compounds such as 6-trimethylbenzophenone;
Dialkoxyacetophenone compounds such as diethoxyacetophenone;
2,4-bis(trichloromethyl)-6-(4-methoxyphenyl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxynaphthyl)-1,3, 5-triazine, 2,4-bis(trichloromethyl)-6-(4-methoxystyryl)-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(5 -methylfuran-2-yl)ethenyl]-1,3,5-triazine, 2,4-bis(trichloromethyl)-6-[2-(furan-2-yl)ethenyl]-1,3,5- Triazines, 2,4-bis(trichloromethyl)-6-[2-(4-diethylamino-2-methylphenyl)ethenyl]-1,3,5-triazine and 2,4-bis(trichloromethyl)-6- triazine compounds such as [2-(3,4-dimethoxyphenyl)ethenyl]-1,3,5-triazine; The photopolymerization initiator may be appropriately selected, for example, from the above photopolymerization initiators in relation to the polymerizable liquid crystal compound contained in the composition for forming a polarizing film.

Moreover, you may use a commercially available photoinitiator. Commercially available polymerization initiators include Irgacure® 907, 184, 651, 819, 250 and 369, 379, 127, 754, OXE01, OXE02, OXE03 (manufactured by BASF); Omnirad BCIM, Esacure 1001M, Esacure KIP160 (from IDM Resins B.V.); Seikuol® BZ, Z, and BEE (from Seiko Chemical Co., Ltd.); kayacure® BP100, and UVI-6992 (from Dow · Chemical Co., Ltd.); Adeka Optomer SP-152, N-1717, N-1919, SP-170, Adeka Arkles NCI-831, Adeka Arkles NCI-930 (manufactured by ADEKA Co., Ltd.); TAZ-A, and TAZ-PP (manufactured by Nihon SiberHegner Co., Ltd.); and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.);

The content of the polymerization initiator in the polarizing film-forming composition for forming the polarizing film is preferably 1 to 10 parts by mass, more preferably 1 to 8 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound. parts, more preferably 2 to 8 parts by mass, particularly preferably 4 to 8 parts by mass. When the content of the polymerization initiator is within the above range, the polymerization reaction of the polymerizable liquid crystal compound can be carried out without greatly disturbing the orientation of the polymerizable liquid crystal compound.

In the present invention, the polymerization rate of the polymerizable liquid crystal compound is preferably 60% or more, more preferably 65% or more, and even more preferably 70% or more, from the viewpoint of line contamination and handling during production.

The polarizing film-forming composition may further contain a photosensitizer. By using a photosensitizer, the polymerization reaction of the polymerizable liquid crystal compound can be further accelerated. Examples of photosensitizers include xanthone compounds such as xanthone and thioxanthone (e.g., 2,4-diethylthioxanthone, 2-isopropylthioxanthone, etc.); phenothiazine and rubrene and the like. Photosensitizers can be used alone or in combination of two or more.

When the polarizing film-forming composition contains a photosensitizer, the content thereof may be appropriately determined according to the types and amounts of the polymerization initiator and the polymerizable liquid crystal compound, but 100 parts by mass of the polymerizable liquid crystal compound. is preferably from 0.1 to 30 parts by mass, more preferably from 0.5 to 10 parts by mass, and even more preferably from 0.5 to 8 parts by mass.

Moreover, the composition for forming a polarizing film may contain a leveling agent. The leveling agent has the function of adjusting the fluidity of the composition for forming a polarizing film and making the coating film obtained by applying the composition for forming a polarizing film more flat. agents. The leveling agent is preferably at least one selected from the group consisting of a leveling agent containing a polyacrylate compound as a main component and a leveling agent containing a fluorine atom-containing compound as a main component. A leveling agent can be used individually or in combination of 2 or more types.

Examples of leveling agents mainly composed of polyacrylate compounds include "BYK-350", "BYK-352", "BYK-353", "BYK-354", "BYK-355", and "BYK-358N". , “BYK-361N”, “BYK-380”, “BYK-381” and “BYK-392” (BYK Chemie).

Leveling agents mainly composed of fluorine atom-containing compounds include, for example, "Megafac (registered trademark) R-08", "R-30", "R-90", "F-410", "F-411", "F-443", "F-445", "F-470", "F-471", "F-477", "F-479", " F-482” and “F-483” (DIC Corporation); “Surflon (registered trademark) S-381”, “S-382”, “S-383”, “S-393”, "SC-101", "SC-105", "KH-40" and "SA-100" (AGC Seimi Chemical Co., Ltd.); "E1830", "E5844" (Daikin Fine Chemicals Laboratory Co., Ltd.) "Ftop EF301", "Ftop EF303", "Ftop EF351" and "Ftop EF352" (Mitsubishi Materials Electronic Chemicals Co., Ltd.).

When the polarizing film-forming composition contains a leveling agent, the content thereof is preferably 0.05 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, relative to 100 parts by mass of the polymerizable liquid crystal compound. . When the content of the leveling agent is within the above range, there is a tendency that the polymerizable liquid crystal compound is easily oriented, unevenness is less likely to occur, and a smoother polarizing film can be obtained.

The polarizing film-forming composition may contain additives other than the photosensitizer and the leveling agent. Other additives include, for example, antioxidants, release agents, stabilizers, colorants such as bluing agents, flame retardants, and lubricants. When the polarizing film-forming composition contains other additives, the content of the other additives is more than 0% and 20% by mass or less based on the solid content of the polarizing film-forming composition. is preferable, more preferably more than 0% and 10% by mass or less.

The polarizing film-forming composition can be produced by a conventionally known method for preparing a polarizing film-forming composition, and generally comprises a polymerizable liquid crystal compound and a dichroic dye, and, if necessary, a polymerization initiator and the above It can be prepared by mixing and stirring additives and the like. In addition, since compounds exhibiting smectic liquid crystallinity generally have high viscosity, a solvent is added to the composition for forming a polarizing film from the viewpoint of improving the coatability of the composition for forming a polarizing film and facilitating the formation of a polarizing film. Viscosity may be adjusted by

The solvent used in the polarizing film-forming composition can be appropriately selected according to the solubility of the polymerizable liquid crystal compound and the dichroic dye used. Specifically, the same solvents as those previously exemplified as the solvent that can be used for the silane compound-containing solution can be mentioned. As the solvent, only one type may be used alone, or two or more types may be used in combination. The content of the solvent is preferably 100 to 1,900 parts by mass, more preferably 150 to 900 parts by mass, and still more preferably 180 to 600 parts by mass, relative to 100 parts by mass of the solid content of the composition for forming a polarizing film. Department.

In the present invention, the polarizing film is preferably a polarizer with a high degree of orientational order. A polarizer with a high degree of orientational order provides a Bragg peak derived from a higher-order structure such as a hexatic phase or a crystal phase in X-ray diffraction measurement. A Bragg peak means a peak derived from a periodic plane structure of molecular orientation. Therefore, the polarizing film constituting the optical laminate of the present invention preferably exhibits a Bragg peak in X-ray diffraction measurement. That is, in the polarizing film constituting the optical laminate of the present invention, the polymerizable liquid crystal compound or its polymer is preferably oriented so that the polarizing film exhibits a Bragg peak in X-ray diffraction measurement. It is more preferable that the molecules of the polymerizable liquid crystal compound are oriented in the direction of absorbing the “horizontal alignment”. In the present invention, a polarizer having a plane period interval of molecular orientation of 3.0 to 6.0 Å is preferred. A high degree of orientational order exhibiting a Bragg peak can be realized by controlling the type of polymerizable liquid crystal compound to be used, the type and amount of dichroic dye, the type and amount of polymerization initiator, and the like.

In the present invention, the polarizing film is formed, for example, by forming a coating film of a composition for forming a polarizing film on an alignment film described later, removing the solvent from the coating film, and causing a phase transition of the polymerizable liquid crystal compound to a liquid phase. A method comprising raising the temperature to a temperature or higher and then lowering the temperature to cause a phase transition of the polymerizable liquid crystal compound to a liquid crystal phase (smectic phase), and polymerizing the polymerizable liquid crystal compound while maintaining the liquid crystal phase. Obtainable.

The method of applying the polarizing film-forming composition to the alignment film includes the same method as the method of applying the silane compound-containing solution onto the substrate.

Next, the solvent is removed by drying or the like under conditions in which the polymerizable liquid crystal compound contained in the coating film obtained from the composition for forming a polarizing film is not polymerized, thereby forming a dry coating film. Drying methods include natural drying, ventilation drying, heat drying, and reduced pressure drying.

Further, in order to cause the phase transition of the polymerizable liquid crystal compound to the liquid phase, the temperature is raised to a temperature equal to or higher than the temperature at which the polymerizable liquid crystal compound undergoes phase transition to the liquid phase, and then the temperature is lowered to convert the polymerizable liquid crystal compound to the liquid crystal phase (smectic phase). transfer. Such a phase transition may be carried out after removing the solvent in the coating film, or may be carried out simultaneously with the removal of the solvent.

By polymerizing the polymerizable liquid crystal compound while maintaining the liquid crystal state of the polymerizable liquid crystal compound, a polarizing film is formed as a cured product of the composition for forming a polarizing film. A photopolymerization method is preferable as the polymerization method. In photopolymerization, the light irradiated to the dry coating film includes the type of polymerizable liquid crystal compound contained in the dry coating film (especially the type of polymerizable group possessed by the polymerizable liquid crystal compound), the type of polymerization initiator and It is appropriately selected according to the amount thereof. Specific examples and irradiation conditions thereof are the same as those exemplified in the formation of the hard coat layer. It is preferable to select the types of the polymerizable liquid crystal compound and the polymerization initiator contained in the polarizing film-forming composition so that they can be photopolymerized by ultraviolet light. The polymerization temperature can also be controlled by light irradiation while cooling the dry coating film with an appropriate cooling means at the time of polymerization. A patterned polarizing film can also be obtained by masking or developing during photopolymerization.

By performing photopolymerization, the polymerizable liquid crystal compound is polymerized while maintaining the liquid crystal state of the liquid crystal phase, particularly the smectic phase, preferably the high-order smectic phase, to form a polarizing film. A polarizing film obtained by polymerizing a polymerizable liquid crystal compound while maintaining the liquid crystal state of the smectic phase is different from the conventional host-guest type polarizing film, that is, the liquid crystal state of the nematic phase, due to the action of the dichroic dye. There is an advantage that the polarizing performance is high as compared with other polarizing films. In addition, it has the advantage of being superior in strength compared to those coated with only dichroic dyes or lyotropic liquid crystals.

The thickness of the polarizing film can be appropriately selected according to the display device to which it is applied, and is preferably 0.1 to 5 μm, more preferably 0.3 to 4 μm, still more preferably 0.5 to 3 μm. When the film thickness of the polarizing film is at least the above lower limit, it is easy to prevent the necessary light absorption from becoming impossible, and when it is at most the above upper limit, orientation defects due to a decrease in the orientation ordering force of the orientation film occur. It is easy to suppress the occurrence of

In the present invention, the polarizing film is preferably laminated adjacent to the alignment film laminated on the first substrate with or without the peel force adjusting layer interposed therebetween. The alignment film has an alignment regulating force that aligns the polymerizable liquid crystal compound in a desired direction. By applying the polarizing film-forming composition onto the alignment film, it is easy to obtain a polarizing film that is aligned with high accuracy. . The alignment film preferably has solvent resistance so that it does not dissolve when the composition for forming a polarizing film is applied, etc., and also has heat resistance in heat treatment for removing the solvent and for aligning the polymerizable liquid crystal compound. In the present invention, the alignment film is preferably a photo-alignment film from the viewpoints of accuracy and quality of the alignment angle, water resistance and bending resistance of the optical layered body including the alignment film. The photo-alignment film is also advantageous in that the direction of the alignment regulating force can be arbitrarily controlled by selecting the polarization direction of the irradiated polarized light.

The photo-alignment film is usually a composition containing a polymer, oligomer or monomer having a photo-reactive group (hereinafter also referred to as "polymer having a photo-reactive group, etc.") and a solvent (hereinafter referred to as "photo-alignment film forming composition”) is applied to the substrate and irradiated with polarized light (preferably polarized UV). In the optical laminate of the present invention, if necessary, the composition for forming a photo-alignment film may be applied onto the first substrate laminated with the release force adjusting layer, and the release force adjusting layer may be applied onto the first substrate. is laminated, the composition for forming a photo-alignment film is applied onto the release force adjusting layer. The polymer or the like contained in the composition for forming a photo-alignment film has the same reactive group as the polymerizable group possessed by the polymerizable liquid crystal compound forming the polarizing film and the functional group possessed by the compound forming the peel force adjusting layer (e.g., ( When the meth) acryloyl group) is present, the adhesion between the release force adjusting layer, the photo-alignment film, and the polarizing film tends to be improved, and zipping occurs when the first substrate is released, and floating at the release interface occurs. It becomes easier to adjust the peeling force F1 to be effective for suppressing the occurrence of .

A photoreactive group refers to a group that exhibits liquid crystal alignment ability upon irradiation with light. Specific examples include groups involved in photoreactions that cause liquid crystal alignment ability, such as orientation induction of molecules caused by light irradiation, isomerization reactions, dimerization reactions, photocrosslinking reactions, photodecomposition reactions, and the like. Among them, a group involved in a dimerization reaction or a photocrosslinking reaction is preferable from the viewpoint of excellent orientation. As the photoreactive group, a group having an unsaturated bond, particularly a double bond is preferable, and a carbon-carbon double bond (C=C bond), a carbon-nitrogen double bond (C=N bond), a nitrogen-nitrogen double bond Groups having at least one selected from the group consisting of a heavy bond (N=N bond) and a carbon-oxygen double bond (C=O bond) are particularly preferred.

Photoreactive groups having a C=C bond include vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups and cinnamoyl groups. Photoreactive groups having a C═N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of the photoreactive group having an N=N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. A benzophenone group, a coumarin group, an anthraquinone group, a maleimide group, etc. are mentioned as a photoreactive group which has a C=O bond. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

Among them, a photoreactive group that participates in a photodimerization reaction is preferable, the amount of polarized light irradiation required for photoalignment is relatively small, and a photoalignment film having excellent thermal stability and stability over time can be easily obtained. Cinnamoyl and chalcone groups are preferred. As a polymer having a photoreactive group, a polymer having a cinnamoyl group having a cinnamic acid structure at the end of the polymer side chain is particularly preferable.

A photo-alignment inducing layer can be formed, for example, by applying the composition for forming a photo-alignment film onto the protective layer laminated on the first film. Examples of the solvent contained in the composition include the same solvents as those previously exemplified as the solvent that can be used in forming the polarizing film, and are appropriately selected depending on the solubility of the polymer having a photoreactive group. can do.

The content of the polymer or the like having a photoreactive group in the composition for forming a photo-alignment film can be appropriately adjusted depending on the type of the polymer or the like and the thickness of the desired photo-alignment film, but the mass of the composition for forming a photo-alignment film is preferably at least 0.2% by mass, more preferably in the range of 0.3 to 10% by mass. The composition for forming a photo-alignment film may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer, as long as the properties of the photo-alignment film are not significantly impaired.

As a method of applying the composition for forming a photo-alignment film onto the substrate or onto the release force adjusting layer, and a method of removing the solvent from the composition for forming a photo-alignment film that has been applied, a solution containing a silane compound is applied to the substrate. Methods similar to methods of coating on and methods of removing the solvent are included.

Irradiation with polarized light may be in the form of directly irradiating polarized UV to the coating film of the photo-alignment film-forming composition after removing the solvent, or in the form of irradiating polarized light from the substrate side and transmitting the polarized light. . Moreover, it is particularly preferable that the polarized light is substantially parallel light. The wavelength of polarized light to be irradiated is preferably in a wavelength range in which a photoreactive group such as a polymer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet rays) with a wavelength in the range of 250 to 400 nm is particularly preferred. Examples of the light source used for the polarized irradiation include a xenon lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, and an ultraviolet light laser such as KrF or ArF. preferable. Among these, high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are preferable because of their high emission intensity of ultraviolet rays having a wavelength of 313 nm. Polarized UV can be emitted by passing the light from the light source through a suitable polarizer. As such a polarizer, a polarizing filter, a polarizing prism such as Glan-Thompson or Glan-Taylor, or a wire grid type polarizer can be used.

A plurality of regions (patterns) having different liquid crystal orientation directions can be formed by masking during rubbing or polarized light irradiation.

The thickness of the photo-alignment film is preferably 10 to 5000 nm, more preferably 10 to 1000 nm, still more preferably 30 to 300 nm. When the thickness of the photo-alignment film is within the above range, it is possible to exhibit good adhesion at the interface with the polarizing film and exhibit alignment ordering power, so that the polarizing film can be formed with high alignment order.

[Phase contrast film]
The retardation film contained in the optical laminate of the present invention is a coating layer, preferably a cured film of a polymerizable liquid crystal composition containing at least one polymerizable liquid crystal compound. In an optical laminate having a circularly polarizing function in which the polarizing film and the retardation film are each made of a cured liquid crystal film, the liquid crystal layer structure of the polarizing film with an excellent degree of alignment order is lost due to zipping caused by transfer and floating at the peeling interface. It has been clarified by the studies of the present inventors that the layer may be destroyed and lead to a decrease in the circularly polarized light function in the laminated body after transfer. The optical laminate of the present invention has the effect of suppressing the occurrence of zipping and floating at the separation interface when the two outer layer surfaces appearing by peeling the first substrate and the second substrate are respectively transferred and incorporated into a display device. Therefore, even after being incorporated into a display device or the like by double-sided transfer, a high circular polarization function can be expected. The optical laminate of the present invention may contain one or two or more retardation films.

The circularly polarizing film transfer sheet of the present invention preferably contains a retardation film that satisfies formula (4).
120 nm≦Re(550)≦170 nm (4)
[In the formula, Re(λ) represents an in-plane retardation value of the retardation film at a wavelength of λnm. ]
When the in-plane retardation Re (550) of the retardation film is within the range of formula (4), the retardation film becomes a retardation film functioning as a quarter-wave plate, and an optical laminate including the retardation film When the body (circularly polarizing plate) is applied to an organic EL display device or the like, the effect of improving the front reflection hue (the effect of suppressing coloring) tends to increase. A more preferable range of the in-plane retardation value is 130 nm≦Re(550)≦150 nm.

Moreover, it is preferable that the retardation film satisfies the following formulas (5) and (6).
Re(450)/Re(550)≤1.00 (5)
1.00≦Re(650)/Re(550) (6)
[In the formula, Re(λ) represents an in-plane retardation value of the retardation film at a wavelength of λnm. ]
When the retardation film satisfies the formulas (5) and (6), the retardation film has an in-plane retardation value at a short wavelength smaller than an in-plane retardation value at a long wavelength, that is, a so-called reverse wavelength dispersion. show gender. An optical layered body (circularly polarizing plate) having such a retardation film tends to be excellent in front hue when incorporated in an organic EL display device or the like. Re(450)/Re(550) is preferably 0.70 or more, more preferably 0.78 or more, from the viewpoint of improving the reverse wavelength dispersion and further enhancing the effect of improving the reflection hue in the front direction. Also, it is preferably 0.92 or less, more preferably 0.90 or less, still more preferably 0.87 or less, particularly preferably 0.86 or less, and most preferably 0.85 or less. Also, Re(650)/Re(550) is preferably 1.01 or more, more preferably 1.02 or more.

The in-plane retardation value can be adjusted by the film thickness dA of the retardation film. Since the in-plane retardation value is determined by the above formula ReA (λ) = (nxA (λ) - nyA (λ)) x dA, the desired in-plane retardation value (ReA (λ): wavelength λ ( In order to obtain the in-plane retardation value of the retardation film in nm), the three-dimensional refractive index and the film thickness dA should be adjusted.

The optical layered body of the present invention preferably includes a retardation film comprising a "horizontally aligned liquid crystal cured film" obtained by curing the polymerizable liquid crystal compound in a state of being aligned in the horizontal direction with respect to the plane of the retardation film. When the optical laminate of the present invention contains one retardation film, the retardation film is usually a "horizontally aligned liquid crystal cured film".

The optical layered body of the present invention may further contain a liquid crystal cured film (retardation film) which is a positive C plate in addition to the retardation film having a quarter wavelength plate function. The cured liquid crystal film, which is a positive C plate, is a “cured vertically aligned liquid crystal film” in which the polymerizable liquid crystal compound is cured in a state of being aligned in the direction perpendicular to the plane of the retardation film. By including a combination of a retardation film having a quarter-wave plate function and a liquid crystal cured film that is a positive C plate, when the optical laminate is applied to an organic EL display device, etc., the front reflection hue is improved. An improvement in oblique reflection hue can also be expected.

When the optical laminate of the present invention includes a cured liquid crystal film that is a positive C plate, the cured liquid crystal film preferably satisfies formulas (7) to (9).
Rth(450)/Rth(550)≦1.00 (7)
1.00≦Rth(650)/Rth(550) (8)
−100 nm≦Rth(550)≦−40 nm (9)
[In the formula, Rth (λ) represents the retardation value in the thickness direction at the wavelength λ nm of the cured liquid crystal film, and is Rth = ((nx (λ) + ny (λ)) / 2-nz) × d (d is represents the thickness of the liquid crystal cured film, nx represents the principal refractive index at the wavelength λnm in the direction parallel to the plane of the liquid crystal cured film in the refractive index ellipsoid formed by the liquid crystal cured film, and ny represents the liquid crystal cured film formed In the refractive index ellipsoid, it is parallel to the plane of the liquid crystal cured film and represents the refractive index at the wavelength λnm in the direction orthogonal to the direction of the nx, and nz is the refraction formed by the liquid crystal cured film In the index ellipsoid, it represents the refractive index at a wavelength λnm in the direction perpendicular to the plane of the cured liquid crystal film). ]

When the liquid crystal cured film satisfies the formulas (7) and (8), the circularly polarizing film containing the retardation film can suppress the decrease in ellipticity on the short wavelength side and improve the oblique reflection hue. can be done. The Rth(450)/Rth(550) value of the cured liquid crystal film is preferably 0.70 or more, more preferably 0.78 or more, and preferably 0.92 or less, more preferably 0.90. Below, it is more preferably 0.87 or less, particularly preferably 0.86 or less, and most preferably 0.85 or less. Also, Rth(650)/Rth(550) is preferably 1.01 or more, more preferably 1.02 or more.

Further, when the liquid crystal cured film satisfies the formula (9), the oblique reflection hue can be improved when the optical laminate (circularly polarizing plate) containing the liquid crystal cured film is applied to an organic EL display device. The retardation value Rth (550) in the thickness direction of the cured liquid crystal film is more preferably −90 nm or more, more preferably −80 nm or more, and more preferably −50 nm or less.

In the present invention, the retardation film is composed of a cured film of a polymerizable liquid crystal composition containing at least one polymerizable liquid crystal compound (hereinafter also referred to as “composition for forming a retardation film”). The polymerizable liquid crystal compound can be appropriately selected from conventionally known polymerizable liquid crystal compounds in the field of retardation films according to desired optical properties.

A polymerizable liquid crystal compound is a liquid crystal compound having a polymerizable group. As the polymerizable liquid crystal compound, in general, a polymer (cured product) obtained by polymerizing the polymerizable liquid crystal compound alone in a state aligned in a specific direction is opposite to the polymerizable liquid crystal compound exhibiting positive wavelength dispersion. and a polymerizable liquid crystal compound exhibiting wavelength dispersion. In the present invention, either one type of polymerizable liquid crystal compound may be used alone, or both types of polymerizable liquid crystal compounds may be mixed and used. Further, when the optical layered body includes a retardation film having a function of a quarter-wave plate and a retardation film composed of a cured liquid crystal film which is a positive C plate, the polymerizable liquid crystal compounds constituting these are the same. may be different. From the viewpoint of easily improving the optical properties of the optical layered body, the retardation film in the optical layered body of the present invention is a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound exhibiting so-called reverse wavelength dispersion. is preferred.

The polymerizable group possessed by the polymerizable liquid crystal compound forming the retardation film in the present invention is preferably a photopolymerizable group. A photopolymerizable group is a polymerizable group, and refers to a group that can participate in a polymerization reaction by a reactive species generated from a photopolymerization initiator, such as an active radical or an acid. Examples of photopolymerizable groups include vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, (meth)acryloyl group, oxiranyl group and oxetanyl group. Among them, a (meth)acryloyl group, a vinyloxy group, an oxiranyl group and an oxetanyl group are preferred, and an acryloyl group is more preferred.

The liquid crystallinity exhibited by the polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal, but the thermotropic liquid crystal is preferable because it enables precise film thickness control. Further, the phase-ordered structure of the thermotropic liquid crystal may be nematic liquid crystal, smectic liquid crystal, or discotic liquid crystal. A polymerizable liquid crystal compound can be used individually or in combination of 2 or more types.

A polymerizable liquid crystal compound having a so-called T-shaped or H-shaped molecular structure tends to exhibit reverse wavelength dispersion when polymerized and cured, and a polymerizable liquid crystal compound having a T-shaped molecular structure exhibits stronger properties. It tends to exhibit reverse wavelength dispersion.

The polymerizable liquid crystal compound exhibiting reverse wavelength dispersion is preferably a compound having the following characteristics (A) to (D).
(A) A compound capable of forming a nematic phase or a smectic phase.
(B) The polymerizable liquid crystal compound has π electrons along the longitudinal direction (a).
(C) It has π electrons in a direction crossing the major axis direction (a) [intersecting direction (b)].
(D) A polymerizable liquid crystal compound defined by the following formula (i), where N (πa) is the sum of π electrons present in the major axis direction (a), and N (Aa) is the sum of the molecular weights present in the major axis direction. π electron density in the long axis direction (a) of
D(πa)=N(πa)/N(Aa) (i)
and a polymerizable liquid crystal compound defined by the following formula (ii), where N(πb) is the sum of π electrons present in the cross direction (b), and N(Ab) is the sum of the molecular weights present in the cross direction (b). π electron density in the cross direction (b) of
D(πb)=N(πb)/N(Ab) (ii)
is the formula (iii)
0≦[D(πa)/D(πb)]<1 (iii)
[that is, the π electron density in the cross direction (b) is higher than the π electron density in the major axis direction (a)]. As described above, a polymerizable liquid crystal compound having π electrons on the major axis and the direction crossing it generally tends to form a T-shaped structure.

In the features (A) to (D) above, the major axis direction (a) and the number of π electrons N are defined as follows.
- The long axis direction (a) is, for example, the long axis direction of a rod-like structure in the case of a compound having a rod-like structure.
- The number of π electrons N (πa) present in the major axis direction (a) does not include π electrons that disappear due to the polymerization reaction.
The number of π electrons N (πa) present along the major axis direction (a) is the total number of π electrons on the major axis and the π electrons conjugated therewith, for example, present along the major axis direction (a) It includes the number of π electrons present in a ring that satisfies Hückel's rule.
- The number of π electrons N (πb) existing in the cross direction (b) does not include π electrons that disappear due to the polymerization reaction.
A polymerizable liquid crystal compound satisfying the above has a mesogenic structure in the major axis direction. A liquid crystal phase (nematic phase, smectic phase) is expressed by this mesogenic structure.

A nematic phase or a smectic phase can be formed by heating a polymerizable liquid crystal compound satisfying the above (A) to (D) above the phase transition temperature. In the nematic phase or smectic phase formed by aligning the polymerizable liquid crystal compound, the major axis directions of the polymerizable liquid crystal compound are usually oriented parallel to each other, and the major axis directions are the nematic phase or the smectic phase. orientation direction. When such a polymerizable liquid crystal compound is made into a film and polymerized in a nematic phase or smectic phase, a polymer film composed of a polymer oriented in the major axis direction (a) can be formed. . This polymer film absorbs ultraviolet rays by π electrons in the long axis direction (a) and π electrons in the cross direction (b). Let λbmax be the absorption maximum wavelength of ultraviolet rays absorbed by π electrons in the cross direction (b). λbmax is typically between 300 nm and 400 nm. The density of π electrons satisfies the above formula (iii), and the π electron density in the cross direction (b) is higher than the π electron density in the major axis direction (a). is greater than the absorption of linearly polarized UV light (wavelength: λbmax) having a plane of vibration in the major axis direction (a). The ratio (absorbance in cross direction (b) of linearly polarized ultraviolet rays/absorbance in long axis direction (a)) is, for example, more than 1.0, preferably 1.2 or more, usually 30 or less, for example 10 or less. is.

Generally, the polymerizable liquid crystal compound having the above characteristics often exhibits reverse wavelength dispersion in the birefringence of the polymer when polymerized in a unidirectionally oriented state. Specifically, for example, a compound represented by the following formula (X) (hereinafter also referred to as “polymerizable liquid crystal compound (X)”) can be used.

In formula (X), Ar represents a divalent group having an optionally substituted aromatic group. Examples of the aromatic group here include groups exemplified by (Ar-1) to (Ar-23) described later. Ar may also have two or more aromatic groups. At least one or more of a nitrogen atom, an oxygen atom and a sulfur atom may be contained in the aromatic group. When the number of aromatic groups contained in Ar is two or more, the two or more aromatic groups may be bonded to each other with a single bond, -CO-O-, or a divalent linking group such as -O-. .

In formula (X), G ¹ and G ² each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group. Here, the hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group is a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, a carbon may be substituted with an alkoxy group, cyano group or nitro group having a number of 1 to 4, and the carbon atoms constituting the divalent aromatic group or divalent alicyclic hydrocarbon group are an oxygen atom or a sulfur atom; Alternatively, it may be substituted with a nitrogen atom.

In formula (X), L ¹ , L ² , B ¹ and B ² are each independently a single bond or a divalent linking group.

In formula (X), k and l each independently represent an integer of 0 to 3 and satisfy the relationship 1≦k+l. Here, when 2≦k+l, B ¹ and B ² and G ¹ and G ² may be the same or different from each other.

In formula (X), E ¹ and E ² each independently represent an alkanediyl group having 1 to 17 carbon atoms, more preferably an alkanediyl group having 4 to 12 carbon atoms. A hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and -CH ₂ - contained in the alkanediyl group is -O-, -S-, -C(=O)- may be substituted with

In formula (X), P ¹ and P ² independently represent a polymerizable group or a hydrogen atom, at least one of which is a polymerizable group.

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

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

B ¹ and B ² are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, —O—, —S—, —R ^a9 OR ^a10 —, —R ^a11 COOR ^a12 —, —R ^a13 OCOR ^a14 -, or -R ^a15 OC= ^{OOR a16} -. Here, R ^a9 to R ^a16 each independently represent a single bond or an alkylene group having 1 to 4 carbon atoms. B ¹ and B ² are each independently more preferably a single bond, -OR ^a10-1 -, -CH ₂ -, -CH ₂ CH ₂ -, ^{-COOR a12-1} -, or -OCOR ^a14-1 - be. Here, Ra ^10-1 , Ra ^12-1 and Ra ^14-1 each independently represent a single bond, —CH ₂ — or —CH ₂ CH ₂ —. B ¹ and B ² are each independently more preferably a single bond, -O-, -CH ₂ CH ₂ -, -COO-, -COOCH _{2 CH 2 -, -OCO- or -OCOCH 2 CH 2 -} be.

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

Polymerizable groups represented by P ¹ or P ² include epoxy group, vinyl group, vinyloxy group, 1-chlorovinyl group, isopropenyl group, 4-vinylphenyl group, (meth)acryloyl group, oxiranyl group, and oxetanyl group and the like. Among them, a (meth)acryloyl group, a vinyl group and a vinyloxy group are preferred, and a (meth)acryloyl group is more preferred.

Ar preferably has at least one selected from an optionally substituted aromatic hydrocarbon ring, an optionally substituted aromatic heterocycle, and an electron-withdrawing group. Examples of the aromatic hydrocarbon ring include benzene ring, naphthalene ring, anthracene ring and the like, with benzene ring and naphthalene ring being preferred. Examples of the aromatic heterocyclic ring include furan ring, benzofuran ring, pyrrole ring, indole ring, thiophene ring, benzothiophene ring, pyridine ring, pyrazine ring, pyrimidine ring, triazole ring, triazine ring, pyrroline ring, imidazole ring, and pyrazole ring. , thiazole ring, benzothiazole ring, thienothiazole ring, oxazole ring, benzoxazole ring, and phenanthroline ring. Among them, it preferably has a thiazole ring, a benzothiazole ring, or a benzofuran ring, and more preferably has a benzothiazole ring. Moreover, when a nitrogen atom is contained in Ar, the nitrogen atom preferably has a π electron.

In formula (X), the total number N _π of π electrons possessed by the group represented by Ar is usually 6 or more, preferably 8 or more, more preferably 10 or more, and still more preferably 14 or more, Especially preferably, it is 16 or more. Also, it is preferably 36 or less, more preferably 32 or less, even more preferably 26 or less, and particularly preferably 24 or less.

Examples of aromatic groups contained in Ar include the following groups.

In formulas (Ar-1) to (Ar-23), the * mark represents a connecting portion, and Z ⁰ , Z ¹ and Z ² each independently represent a hydrogen atom, a halogen atom, or an alkyl having 1 to 12 carbon atoms. a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, alkylthio group having 1 to 12 carbon atoms, N-alkylamino group having 1 to 12 carbon atoms, N,N-dialkylamino group having 2 to 12 carbon atoms, N-alkylsulfamoyl group having 1 to 12 carbon atoms or carbon represents an N,N-dialkylsulfamoyl group of numbers 2 to 12; Moreover, Z ⁰ , Z ¹ and Z ² may contain a polymerizable group.

In formulas (Ar-1) to (Ar-23), Q ¹ and Q ² are each independently -CR ^2' R ^3' -, -S-, -NH-, -NR ^2' -, - represents CO— or —O—, and R ^2′ and R ^3′ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

In formulas (Ar-1) to (Ar-23), J ¹ and J ² each independently represent a carbon atom or a nitrogen atom.

In formulas (Ar-1) to (Ar-23), Y ¹ , Y ² and Y ³ each independently represent an optionally substituted aromatic hydrocarbon group or aromatic heterocyclic group.

In formulas (Ar-1) to (Ar-23), W ¹ and W ² each independently represent a hydrogen atom, a cyano group, a methyl group or a halogen atom, and m represents an integer of 0-6.

Examples of the aromatic hydrocarbon group for Y ¹ , Y ² and Y ³ include aromatic hydrocarbon groups having 6 to 20 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group and biphenyl group. , is preferably a naphthyl group, more preferably a phenyl group. The aromatic heterocyclic group includes a C4-20 group containing at least one heteroatom such as a nitrogen atom, an oxygen atom, a sulfur atom such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group and a benzothiazolyl group. An aromatic heterocyclic group can be mentioned, and a furyl group, a thienyl group, a pyridinyl group, a thiazolyl group, and a benzothiazolyl group are preferable.

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

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

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

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

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

The compound represented by formula (X) can be produced, for example, according to the method described in JP-A-2010-31223.

As the polymerizable liquid crystal compound forming the retardation film in the present invention, in addition to the compound represented by the formula (X), or apart from this, for example, JP-A-2010-31223, JP-A-2010-270108 Polymerizable liquid crystal compounds such as those described in JP-A-2011-6360 and JP-A-2011-207765, so-called polymerizable liquid crystal compounds exhibiting positive wavelength dispersion may be used. Any of these polymerizable liquid crystal compounds can be used with horizontal alignment or with vertical alignment.

The content of the polymerizable liquid crystal compound in the retardation film-forming composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99.5 parts by mass, with respect to 100 parts by mass of the solid content of the retardation film-forming composition. 99 parts by mass, preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of orientation of the obtained retardation film. When the retardation film-forming composition contains two or more polymerizable liquid crystal compounds, the total amount of all the liquid crystal compounds contained in the retardation film-forming composition is preferably within the above content range. .

The retardation film-forming composition may contain a polymerization initiator for initiating the polymerization reaction of the polymerizable liquid crystal compound. The polymerization initiator can be appropriately selected from those conventionally used in the field, and may be a thermal polymerization initiator or a photopolymerization initiator. A photopolymerization initiator is preferable because it can initiate a polymerization reaction. Suitable photopolymerization initiators that can be used in the composition for forming a polarizing film are the same as those exemplified above.

Since the composition for forming a retardation film is usually applied to a substrate film or the like in a state of being dissolved in a solvent, it preferably contains a solvent. As the solvent, a solvent capable of dissolving the polymerizable liquid crystal compound is preferable, and a solvent inert to the polymerization reaction of the polymerizable liquid crystal compound is preferable. Examples of the solvent include the same solvents as those previously exemplified as usable in the polarizing film-forming composition.

In addition, the composition for forming a retardation film may contain, if necessary, the photosensitizer, the leveling agent, and the additives exemplified as additives contained in the composition for forming a polarizing film. Examples of the photosensitizer and leveling agent include those exemplified above as usable in the composition for forming a polarizing film.

The composition for forming a retardation film can be prepared, for example, by mixing and stirring a polymerizable liquid crystal compound and, if necessary, a polymerization initiator, a solvent, additives, and the like.

For the retardation film, for example, the retardation film-forming composition is coated on the second substrate, the alignment film or the release force adjusting layer, the coating is dried, and the retardation film-forming composition is It can be obtained by aligning the polymerizable liquid crystal compound inside and then polymerizing the polymerizable liquid crystal compound by light irradiation or the like while maintaining the aligned state. As the alignment film, the same ones as those exemplified above can be used in producing the polarizing film of the present invention. The method of applying the retardation film-forming composition and the method of curing the polymerizable liquid crystal compound by light irradiation are the same as those exemplified in the method of forming the polarizing film.

In the optical laminate of the present invention, the thickness of the retardation film can be appropriately selected according to the display device to which it is applied. , more preferably 0.5 to 5 μm, still more preferably 1 to 3 μm. When the optical layered body of the present invention includes a plurality of retardation films, the thickness of each retardation film may be the same or different, but preferably within the above range.

When the optical laminate of the present invention includes a retardation film having a quarter-wave plate function and a retardation film composed of a cured liquid crystal film that is a positive C plate, these retardation films are attached via an adhesive layer. Although it may be laminated, from the viewpoint of thinning the optical laminate and bending resistance suitable as a flexible display material, an alignment having a vertical alignment control force is placed on a retardation film having a quarter wavelength plate function. A retardation film composed of a cured liquid crystal film that is a positive C plate is laminated with or without a film, or a retardation film composed of a cured liquid crystal film that is a positive C plate is provided with a horizontal alignment regulating force. It is preferable that a retardation film having a quarter wavelength plate function is laminated with or without an alignment film having a .

[Adhesive layer]
In the present invention, the adhesive layer disposed between the polarizing film and the retardation film is a layer formed from an adhesive. The tacky-adhesive layer can be formed from a known tacky-adhesive agent as long as it can function as a layer for bonding the polarizing film and the retardation film. In one embodiment of the invention, the adhesive layer is formed from an adhesive composition.

Examples of adhesive compositions include adhesive compositions containing resins such as (meth)acrylic, rubber, urethane, ester, silicone, and polyvinyl ether as main components. Among them, a pressure-sensitive adhesive composition using a (meth)acrylic resin as a base polymer, which is excellent in transparency, weather resistance, heat resistance, etc., is preferable.

Examples of the (meth)acrylic resin (base polymer) used in the adhesive composition include butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, and 2-(meth)acrylate. Polymers or copolymers containing one or more of (meth)acrylic acid esters such as ethylhexyl as monomers are preferably used. Preferably, the base polymer is copolymerized with a polar monomer. Examples of polar monomers include (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, glycidyl ( Monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, etc., such as meth)acrylates, can be mentioned.

The pressure-sensitive adhesive composition may contain only the above base polymer, but may also contain a cross-linking agent. The cross-linking agent is a metal ion having a valence of 2 or more, which forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound, which forms an amide bond with a carboxyl group; Examples include epoxy compounds and polyols that form ester bonds with carboxyl groups; and polyisocyanate compounds that form amide bonds with carboxyl groups.

The pressure-sensitive adhesive composition may contain a solvent, if necessary, and examples of the solvent include the solvents exemplified as the solvents that can be used in the polarizing film-forming composition and the like.

The thickness of the adhesive layer is usually 1-40 μm, preferably 3-25 μm.

When the polarizing film and the retardation film are laminated, it is preferable to laminate such that the slow axis (optical axis) of the retardation film and the absorption axis of the polarizing film are substantially at 45°. By laminating so that the slow axis (optical axis) of the retardation film and the absorption axis of the polarizing film are substantially 45°, the function as a circularly polarizing plate can be obtained. Incidentally, substantially 45° is usually in the range of 45±5°.

[Optical laminate]
The optical laminate of the present invention comprises a first base material, an alignment film, a polarizing film, an adhesive layer, a retardation film and a second base material, and if necessary, a Accordingly, the peel force adjusting layer can be manufactured by forming and laminating layers in an appropriate order according to the manufacturing method described above for each layer.
For example, a laminate is produced by forming a release force adjusting layer on a first substrate and providing a polarizing film on the release force adjusting layer with an alignment film interposed therebetween. Separately from this, a laminate is prepared by forming a peel force adjusting layer on the second substrate and providing a retardation film on the peel force adjusting layer via an alignment film, and a laminate having a polarizing film. , By bonding the laminate having the retardation film with an adhesive, the first base material/peeling force adjusting layer/orientation film/polarizing film/adhesive layer/position as shown in FIG. An optical layered body composed of retardation film/orientation film/peeling force adjusting layer/second substrate is obtained.

In the optical laminate of the present invention, the total thickness of the polarizing film, adhesive layer and retardation film is preferably 20 μm or less, more preferably 15 μm or less.

The optical layered body of the present invention may be in the form of a long film or in the form of a sheet.

In the optical layered body of the present invention, both the peelable first base material and the peelable second base material constituting the optical layered body are peeled off, leaving only the layered structure having the function of a circularly polarizing plate on the transferred body. It is used by transferring to In the optical layered body of the present invention, the peeling force F1 and the peeling force F2 are controlled within a predetermined range, and the difference between these two peeling forces is set within a predetermined range. To enable easy peeling of a first base material and a second base material in a desired order while suppressing floating at a peeling interface. In particular, even when the optical layered body is elongated, it is easy to maintain a desired peeling force over the entire length of the layered body. Therefore, even if the first substrate and/or the second substrate are continuously peeled off by the Roll to Roll method using an apparatus commonly used in the field, special conditions are set. It is excellent in the effect of suppressing the occurrence of zipping at the time of peeling and floating at the peeling interface.

The optical layered body of the present invention can be prepared by using a general apparatus conventionally and widely used in the relevant field for manufacturing an optical film, an optical layered body, etc., using a first substrate or a second substrate in the desired order. It can be continuously and easily peeled off from the optical layered body, and it is difficult for the layered body to be transferred to zip or float at the peeling interface, so it is suitable for the production of a long optical film using the Roll to Roll method. is.

The present invention
a step of producing a long optical layered body roll obtained by winding the optical layered body of the present invention into a roll; and
From the elongated optical layered body roll, the substrate having a smaller peeling force when peeled from the optical layered body out of the first base material and the second base material constituting the optical layered body is continuously peeled off. It includes a method for manufacturing a long optical film, including a first peeling step.

The method for manufacturing the long optical laminate roll further comprises:
A lamination step of laminating a third substrate through an adhesive layer on the surface where the substrate peeled in the first peeling step was adjacent, and
A second peeling step of peeling off the first substrate or the second substrate that has not been peeled off in the first peeling step may be included.

Examples of the third base material used in the method include resin films, separator films, protective films, etc. that can be used as the first base material and/or the second base material. The separator film may have a pressure-sensitive adhesive layer on the side opposite to the side where the substrate was adjacent.

The optical layered body of the present invention is suitable as an elliptically polarizing plate because it does not easily cause zipping or floating at the peeled interface due to peeling of the first base material and the second base material, and has excellent optical performance in the layered body after transfer. be. Accordingly, the present invention also covers an elliptically polarizing plate containing the optical laminate of the present invention. The elliptically polarizing plate of the present invention can be used for various display devices.
A display device is a device having a display element, and includes a light-emitting element or a light-emitting device as a light source. Examples of display devices include liquid crystal displays, organic electroluminescence (EL) displays, inorganic electroluminescence (EL) displays, touch panel displays, electron emission displays (e.g. field emission displays (FED), surface field emission displays). (SED)), electronic paper (display device using electronic ink or electrophoretic element, plasma display device, projection display device (e.g. grating light valve (GLV) display device, display device having digital micromirror device (DMD) ) and piezoelectric ceramic displays, etc. Liquid crystal display devices include transmissive liquid crystal display devices, semi-transmissive liquid crystal display devices, reflective liquid crystal display devices, direct view liquid crystal display devices, projection liquid crystal display devices, and the like. These display devices may be display devices that display two-dimensional images or stereoscopic display devices that display three-dimensional images. (EL) display device and inorganic electroluminescence (EL) display device, and can also be suitably used for liquid crystal display device and touch panel display device. By providing the elliptically polarizing plate of the present invention, which is less likely to occur, good image display characteristics can be exhibited.

In addition, the optical layered body of the present invention can be transferred to another base material while suppressing the occurrence of zipping and floating at the separation interface even when thinning and bending resistance are required. Since the laminated body after transfer can be expected to have high circular polarization function and optical properties, it is also advantageous as an optical laminated body constituting a flexible display material. Accordingly, the present invention is also directed to flexible display materials comprising the optical stacks of the present invention. The flexible display materials of the present invention can be suitably incorporated into flexible image display devices.

The present invention will be described in more detail below with reference to examples and comparative examples. "%" and "parts" in Examples and Comparative Examples are "% by mass" and "parts by mass" unless otherwise specified.

・ウレタンアクリレートポリマー：５０部
ウレタンアクリレート（ダイセル・オルネクス（株）製、「エベクリル４８５８」）、官能基数は２、重量平均分子量Ｍｗは４５０、単位分子量あたりの官能基数は、４４．４×１０ ^－４ である。
・ラジカル重合開始剤：３部
２－［４－（メチルチオ）ベンゾイル］－２－（４－モルホリニル）プロパン（ＢＡＳＦ社製、「イルガキュア９０７」）
・溶剤：１０部
メチルエチルケトン 1. Preparation of laminate containing polarizing film (polarizing film laminate) (1) Preparation of laminate A1 (i) Preparation of resin composition for forming peel force adjusting layer (1) The following components were mixed and heated at 50°C. By stirring for 4 hours, a resin composition (1) for forming a release force adjusting layer was obtained.
- Polyfunctional acrylate compound having the following structure: 50 parts dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Ester A-DPH"), the branch point closest to the acryloyl group in the branched structure, and the acryloyl group The number of atoms in the chain connecting the is two.

Urethane acrylate polymer: 50 parts Urethane acrylate ("Ebecryl 4858" manufactured by Daicel Allnex Co., Ltd.), the number of functional groups is 2, the weight average molecular weight Mw is 450, the number of functional groups per unit molecular weight is 44.4 × 10 ^{- 4} .
- Radical polymerization initiator: 3 parts 2-[4-(methylthio)benzoyl]-2-(4-morpholinyl)propane (manufactured by BASF, "Irgacure 907")
・Solvent: 10 parts methyl ethyl ketone

（特開２０１３－０３３２４９号公報に記載のポリマー、数平均分子量：約２８２００、Ｍｗ／Ｍｎ：１．８２）
・溶剤：９８部
ｏ－キシレン (ii) Preparation of Composition for Forming Photo-Alignment Film A composition (1) for forming a photo-alignment film was obtained by mixing the following components and stirring the resulting mixture at 80° C. for 1 hour.
・Photo-orientable polymer: 2 parts

(Polymer described in JP-A-2013-033249, number average molecular weight: about 28200, Mw/Mn: 1.82)
・Solvent: 98 parts o-xylene

・重合性液晶化合物：Ａ２ １０部

・二色性色素：アゾ色素Ａ ２．５部

・二色性色素：アゾ色素Ｂ ２．５部

・二色性色素：アゾ色素Ｃ ２．５部

・光重合開始剤：６部
２－ジメチルアミノ－２－ベンジル－１－（４－モルホリノフェニル）ブタン－１－オン（イルガキュア３６９；チバ・スペシャルティ・ケミカルズ(株)製）
・レベリング剤：１．２部
ポリアクリレート化合物（ＢＹＫ－３６１Ｎ；ＢＹＫ－Ｃｈｅｍｉｅ社製）
・溶剤：４００部
ｏ－キシレン (iii) Preparation of Polarizing Film-Forming Composition (1) The following components were mixed and stirred at 80° C. for 1 hour to obtain a polarizing film-forming composition (1). As the dichroic dye, an azo dye described in Examples of JP-A-2013-101328 was used.
・Polymerizable liquid crystal compound: 90 parts of A1

・Polymerizable liquid crystal compound: 10 parts of A2

・ Dichroic dye: 2.5 parts of azo dye A

・ Dichroic dye: 2.5 parts of azo dye B

・ Dichroic dye: 2.5 parts of azo dye C

Photopolymerization initiator: 6 parts 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals Co., Ltd.)
- Leveling agent: 1.2 parts Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
・Solvent: 400 parts o-xylene

(iv) Preparation of base material with release force adjusting layer (1) Using a release-treated polyethylene terephthalate film (SP-PLR382050 manufactured by Lintec) as a base material, corona was applied to the release-treated surface of the base film. After the treatment, the release force adjusting layer-forming composition (1) was applied by a bar coating method (#2, 30 mm/s). The coating film of the obtained composition for forming a release force adjusting layer (1) was irradiated with ultraviolet rays at an exposure amount of 500 mJ/cm ² (365 nm standard) using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.). A substrate with a peel force adjusting layer (1) was obtained by irradiating. The thickness of the peel force adjusting layer (1) measured with a laser microscope (OLS3000 manufactured by Olympus Corporation) was 1.5 μm.

(v) Preparation of polarizing film Next, after subjecting the surface of the peel force adjusting layer (1) of the base material with the peel force adjusting layer (1) to corona treatment, the composition for forming a photo-alignment film (1) is applied. and dried at 120° C. to obtain a dry coating film. A photo-alignment film was formed by irradiating polarized UV onto this dried coating film to obtain a laminate having first substrate/peeling force adjusting layer (1)/photo-alignment film in this order. The polarized UV treatment was performed using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.) under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ. The thickness of the photo-alignment film measured with a laser microscope (OLS3000 manufactured by Olympus Corporation) was 100 nm.

On the surface of the photo-alignment film of the obtained laminate, the polarizing film-forming composition (1) is applied by a bar coating method, and dried by heating in a drying oven at 120° C. for 1 minute to form a polymerizable liquid crystal compound. After phase transition to a liquid phase, the polymerizable liquid crystal compound was cooled to room temperature to phase transition to a smectic liquid crystal state. Next, using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.), the coating formed from the composition for forming a polarizing film (1) was irradiated with ultraviolet rays at an exposure amount of 1000 mJ/cm ² (365 nm standard). By irradiating the film, the polymerizable liquid crystal compound contained in the dry coating film was polymerized while maintaining the smectic liquid crystal state of the polymerizable liquid crystal compound, and a polarizing film (polarizer) was formed from the dry coating film. . The thickness of the polarizing film measured with a laser microscope (OLS3000 manufactured by Olympus Corporation) was 2.3 μm.
In this manner, a laminate A1 having the first substrate/peeling force adjusting layer (1)/photo-alignment film/polarizing film in this order was obtained.

(2) Laminate A2
(i) Preparation of Polarizing Film-Forming Composition (2) A polarizing film-forming composition (2) was prepared in the same manner as in the preparation of the polarizing film-forming composition (1), except that the following solvents were used. Obtained.
・Solvent: 250 parts Cyclopentanone

（特開２０１３－０３３２４９号公報に記載のポリマー、数平均分子量：約２８２００、Ｍｗ／Ｍｎ：１．８２）
・溶剤：９５部
シクロペンタノン (ii) Preparation of Composition for Forming Photo-Alignment Film A composition (2) for forming a photo-alignment film was obtained by mixing the following components and stirring the resulting mixture at 80° C. for 1 hour.
・Photo-alignable polymer: 5 parts

(Polymer described in JP-A-2013-033249, number average molecular weight: about 28200, Mw/Mn: 1.82)
・Solvent: 95 parts Cyclopentanone

(iii) Fabrication of photo-alignment film Zeonor (registered trademark) film (manufactured by Nippon Zeon Co., Ltd.), which is a cycloolefin film, was used as a substrate. After corona treatment was applied to the first base film, the composition for forming a photo-alignment film (2) was applied by a bar coating method and dried by heating in an oven at 60° C. for 1 minute. The resulting dried coating film was subjected to polarized UV irradiation treatment to form a photo-alignment film on the surface of the first substrate, thereby obtaining a laminate having first substrate/photo-alignment film in this order. The polarized UV treatment was performed using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.) under the condition that the intensity measured at a wavelength of 365 nm was 100 mJ. The film thickness of the photo-alignment film measured with a laser microscope (OLS3000 manufactured by Olympus Corporation) was 100 nm.

(iv) Preparation of polarizing film On the surface of the photo-alignment film of the obtained laminate, the composition for forming a polarizing film (2) was applied by a bar coating method (#7 30 mm/s) and placed in an oven at 120°C. After drying by heating for 1 minute, the polymerizable liquid crystal compound was phase-transitioned to the liquid phase, and then cooled to room temperature to cause the phase-transition of the polymerizable liquid crystal compound to the smectic liquid crystal state. Then, using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.), ultraviolet irradiation is performed at an exposure amount of 1200 mJ/cm ² (365 nm standard) to remove the polymerizable liquid crystal compound contained in the dry coating film. A polarizing film (polarizer) was formed from the dried coating film by polymerizing the polymerizable liquid crystal compound while maintaining the smectic liquid crystal state. When the thickness of the formed polarizing film was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 1.8 μm.
Thus, a laminate A2 having the first base material/photo-alignment film/polarizing film in this order was obtained.

(3) Laminate A3
The same as laminate A1, except that the release force adjusting layer (1) was laminated on the untreated side of a polyethylene terephthalate film (SP-PLR382050 manufactured by Lintec Co., Ltd.) with one side subjected to release treatment as a base material. A laminate A3 having a first base material/peeling force adjusting layer (1)/photo-alignment film/polarizing film in this order was obtained by the method.

(4) Laminate A4
(i) Preparation of release force adjusting layer-forming composition (2) KBE-903 (manufactured by Shin-Etsu Silicone Co., Ltd.), which is a silane coupling agent, was dissolved in o-xylene to a concentration of 0.25% by weight, and the release force was An adjustment layer-forming composition (2) was prepared.

(ii) Preparation of polarizing film The composition for forming a release force adjusting layer (2) was applied to the untreated side of a polyethylene terephthalate film (SP-PLR382050 manufactured by Lintec) with one side subjected to release treatment. It was applied by a coating method and dried in an oven at 120° C. for 1 minute to form a peel force adjusting layer (2) (layer containing a silane compound) with a thickness of 40 nm. Subsequently, the composition for forming a release force adjusting layer (1) was applied by a bar coating method, and an exposure amount of 500 mJ/cm ² (365 nm) was applied using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.). The release force adjustment layer (1) is formed by irradiating the coating film of the resin composition for forming the release force adjustment layer (1) with ultraviolet rays of standard), and the first substrate / release force adjustment layer (2) / A laminate having the peel force adjusting layer (1)/ in this order was obtained. The thickness of the peel force adjusting layer (1) measured with a laser microscope (OLS3000 manufactured by Olympus Corporation) was 1.5 μm.
Subsequently, the first substrate/peeling force adjusting layer (2)/peeling force adjusting layer (1)/photo-aligning film/polarizing film are formed by the same procedure as the method for producing the photo-alignment film and the polarizing film in the laminate A1. A laminate A4 having these order was obtained.

(5) Laminate A5
(i) Preparation of release force adjusting layer-forming composition (3) KBM-5103 (manufactured by Shin-Etsu Silicone Co., Ltd.), which is a silane coupling agent, was dissolved in o-xylene to a concentration of 0.25% by weight. An adjustment layer-forming composition (3) was prepared.

(ii) Preparation of polarizing film The method for preparing the polarizing film laminate A4 was the same as the method for preparing the polarizing film laminate A4, except that the composition for forming a peel force adjusting layer (3) was used instead of the composition for forming a peel force adjusting layer (2). According to the procedure, a laminate A5 having first substrate/peeling force adjusting layer (3)/peeling force adjusting layer (1)/photo-alignment film/polarizing film in this order was obtained. The thickness of the peel force adjusting layer (3) was 40 nm.

(6) Laminate A6
Except for using a polyethylene terephthalate film (manufactured by Mitsubishi Plastics, Inc., Diafoil) with a thickness of 100 μm as the first substrate, the same procedure as in the method for producing the laminate A4 was performed as the first substrate / peel force adjustment layer (2 )/peeling force adjusting layer (1)/photo-alignment film/polarizing film in this order to obtain a laminate A6.

・重合性液晶化合物：Ｘ２ ２０部

・重合開始剤：６部
２－ジメチルアミノ－２－ベンジル－１－（４－モルホリノフェニル）ブタン－１－オン（イルガキュア（登録商標）３６９；チバ スペシャルティケミカルズ社製）
・レベリング剤：０．１部
ポリアクリレート化合物（ＢＹＫ－３６１Ｎ；ＢＹＫ－Ｃｈｅｍｉｅ社製
・溶剤：４００部
シクロペンタノン 2. Preparation of laminate containing retardation film (retardation film laminate) (1) Preparation of laminate B1 (i) Preparation of composition for forming retardation film (1) The following components were mixed to obtain The mixture was stirred at 80° C. for 1 hour to obtain a retardation film-forming composition (1).
Polymerizable liquid crystal compound X1 and polymerizable liquid crystal compound X2 were synthesized by the method described in JP-A-2010-31223.
・Polymerizable liquid crystal compound: X1 80 parts

・Polymerizable liquid crystal compound: 20 parts of X2

- Polymerization initiator: 6 parts 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure (registered trademark) 369; manufactured by Ciba Specialty Chemicals)
・ Leveling agent: 0.1 part Polyacrylate compound (BYK-361N; manufactured by BYK-Chemie ・ Solvent: 400 parts Cyclopentanone

(ii) Production of retardation film First substrate/peeling force in polarizing film laminate A1 except for using composition for forming photo-alignment film (2) instead of composition for forming photo-alignment film (1) A laminate having second base material/peeling force adjusting layer (1)/photo-alignment film in this order was obtained by the same procedure as the method for producing a laminate having adjustment layer (1)/photo-alignment film in this order.

On the surface of the photo-alignment film of the obtained laminate, the composition for forming a retardation film (1) is applied by a bar coating method, dried by heating in an oven at 120° C. for 1 minute, then cooled to room temperature and dried. A membrane was obtained. The obtained dried coating film was irradiated with ultraviolet rays at an exposure amount of 1000 mJ/cm ² (365 nm standard) using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.), and the polymerizable liquid crystal compound was used as the base material. A cured retardation film was formed in a state of being oriented horizontally with respect to the in-plane. When the thickness of the formed retardation film was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 2.0 μm.
In this manner, a laminate B1 having the second substrate/peeling force adjusting layer (1)/photo-alignment film/retardation film in this order was obtained.

(2) Preparation of laminate B2 A retardation film is applied to the surface of the photo-alignment film of the laminate obtained by the same procedure as the method for producing the laminate having the first substrate/photo-alignment film in this order in the laminate A2. The forming composition (1) was applied by a bar coating method, dried by heating in an oven at 120° C. for 1 minute, and then cooled to room temperature to obtain a dry coating film. The obtained dried coating film was irradiated with ultraviolet rays at an exposure amount of 1000 mJ/cm ² (365 nm standard) using a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Inc.), and the polymerizable liquid crystal compound was used as the base material. A cured retardation film was formed in a state of being oriented horizontally with respect to the in-plane. When the thickness of the formed retardation film was measured with a laser microscope (OLS3000 manufactured by Olympus Corporation), it was 2.0 μm.
Thus, a laminate B2 having the second base material/photo-alignment film/retardation film in this order was obtained.

(3) Production of laminate B3 In the same manner as laminate B1, except that the release force adjusting layer (1) was laminated on the untreated side of the polyethylene terephthalate film on which one side was subjected to release treatment. , second substrate/peeling force adjusting layer (1)/photo-alignment film/retardation film in this order.

(4) Production of Laminate B4 Laminate obtained in the same manner as the method for producing a laminate having the first base material/peeling force adjusting layer (2)/peeling force adjusting layer (1) in this order in the laminate A4 A photo-alignment film and a retardation film were produced on the surface of the peel force adjusting layer (1) of No. by the same procedure as the method for producing the photo-alignment film and the retardation film in the laminate B1.
In this manner, a laminate B4 having, in this order, the second substrate/peeling force adjusting layer (2)/peeling force adjusting layer (1)/photo-alignment film/retardation film was obtained.

(5) Production of laminate B5 In the same manner as the laminate B4, except that the release force adjustment layer-forming composition (3) was used instead of the release force adjustment layer-forming composition (2). , second substrate/peeling force adjusting layer (3)/peeling force adjusting layer (1)/photo-alignment film/retardation film in this order.

(6) Laminate B6
The second substrate/peeling force adjusting layer (2 )/peeling force adjusting layer (1)/photo-alignment film/retardation film in this order.

3. Preparation of Optical Laminate Laminates A1 to A6, which are polarizing film laminates, and Laminates B1 to B6, which are retardation film laminates, were laminated in the combinations shown in Table 1, and Examples 1 to 8 and Optical laminates of Comparative Examples 1 to 5 were produced. The polarizing film laminate and the retardation film laminate were bonded together by bonding the polarizing film side of the polarizing film laminate and the retardation film side of the retardation film laminate with an adhesive.
As an adhesive for bonding the polarizing film laminate and the retardation film laminate, a sheet-like adhesive ["NCF #L2" manufactured by Lintec Corporation] was used. The thickness of the adhesive layer was 5 μm.

4. Measurement Method of Peeling Force The peeling force F1 when peeling the first base material from the optical layered body and the peeling force F2 when peeling the second base material from the optical layered body were each measured by the following methods. . Table 1 shows the results.
Using a tensile tester, grip one end of the test piece (width 25 mm × length about 150 mm) in the length direction, under an atmosphere of temperature 23 ° C. and relative humidity 60%, crosshead speed (grip movement speed) 200 mm / min. JIS K 6854-1:1999 "Adhesive-Peeling adhesive strength test method-Part 1: 90 degree peeling" was performed and measured.

5. Evaluation of Peelability A test piece having a width of about 50 mm and a length of about 200 mm was cut from each of the optical laminates produced in Examples and Comparative Examples. Using a tensile tester (TJ-95 manufactured by Imada Seisakusho Co., Ltd.), the end of the substrate to be peeled is gripped, and the substrate is gripped at a temperature of 23 ° C. and a relative humidity of 60% at a grip movement speed of 5 m / min. Peeled off the material. The peelability was evaluated according to the following criteria.
<Peelability Evaluation Criteria>
A: The rate of occurrence of lifting and zipping at the peel interface was less than 5% of the test length.
B: Lifting and zipping occurred at the separation interface. The incidence was 5% or more and less than 50% of the test length.
C: Lifting and zipping occurred at the separation interface. The incidence was greater than 50% of the test length.

6. Appearance inspection For the optical laminates obtained in Examples and Comparative Examples, the first and second substrates were peeled off, and an aluminum plate was bonded to the surface from which the second substrate was peeled off via a pressure-sensitive adhesive. did. The presence or absence of unevenness was observed in the front vertical direction of the bonded optical layered body and from a position at an elevation angle of 50° from the front vertical direction.
<Appearance evaluation criteria>
A: No unevenness was visually recognized.
B: Unevenness was visually recognized at a position with an elevation angle of 50° from the front vertical direction.
C: Unevenness was visually recognized in the front vertical direction and at a position at an elevation angle of 50° from the front vertical direction.

1: First Substrate 2: Alignment Film 3: Polarizing Film 4: Adhesive Layer 5: Retardation Film 6: Alignment Film 7: Second Substrate 8, 9: Peel Force Adjustment Layer 11: Optical Laminate 12: Laminate structure

Claims (14)

An optical laminate comprising a first substrate, an alignment film, a polarizing film, an adhesive layer, a retardation film and a second substrate in this order,
The polarizing film and the retardation film are each a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound,
The polarizing film is a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound exhibiting a smectic liquid crystal phase,
The peeling force F1 when peeling the first substrate from the optical layered body and the peeling force F2 when peeling the second substrate from the optical layered body are expressed by the following formulas (1), (2) and (3). ):
0.02 (N/25mm)≤F1≤0.30 (N/25mm) (1)
0.02 (N/25mm)≤F2≤0.30 (N/25mm) (2)
0.03 (N/25mm)≦|F1−F2| (3)
The filling,
An optical laminate having a release force adjusting layer on at least one of the polarizing film-side surface of the first substrate and the retardation film-side surface of the second substrate. 2. The optical laminate according to claim 1, wherein the peel force adjusting layer is a layer containing a silane compound or a hard coat layer. 3. The optical laminate according to claim 1, wherein the thickness of the first base material is 20 [mu]m or more and 100 [mu]m or less. 4. The optical laminate according to any one of claims 1 to 3, wherein the second substrate has a thickness of 20 µm or more and 100 µm or less. 5. The optical laminate according to any one of claims 1 to 4, wherein the first base material is a resin film composed of at least one selected from cellulose resins, cyclic olefin resins and polyethylene terephthalate resins. 6. The optical laminate according to any one of claims 1 to 5, wherein the second base material is a resin film composed of at least one selected from cellulose resins, cyclic olefin resins and polyethylene terephthalate resins. 7. The optical laminate according to claim 1, wherein the polarizing film is a cured film of a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound and a dichroic dye. The retardation film has the formula (4):
120 nm≦Re(550)≦170 nm (4)
[Wherein, Re (λ) represents the in-plane retardation value of the retardation film at a wavelength of λnm]
The optical laminate according to any one of claims 1 to 7, which satisfies 9. The optical laminate according to claim 8, further comprising a liquid crystal cured film that is a positive C plate. 10. The optical layered body according to claim 1, wherein the total thickness of the polarizing film, adhesive layer and retardation film is 20 μm or less. A step of producing a long optical layered body roll obtained by winding the optical layered body according to any one of claims 1 to 10 into a roll, and
From the elongated optical layered body roll, the substrate having a smaller peeling force when peeled from the optical layered body out of the first base material and the second base material constituting the optical layered body is continuously peeled off. A method for producing a long optical film, comprising a first peeling step. A lamination step of laminating a third substrate through an adhesive layer on the surface where the substrate peeled in the first peeling step was adjacent, and
12. The method for producing a long optical film according to claim 11, further comprising a second peeling step of peeling off the first substrate or the second substrate that has not been peeled off in the first peeling step. An elliptically polarizing plate comprising the optical laminate according to any one of claims 1 to 10. A flexible display material comprising the optical laminate according to any one of claims 1-10.

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