WO2021177040A1

WO2021177040A1 - Optical laminate

Info

Publication number: WO2021177040A1
Application number: PCT/JP2021/006062
Authority: WO
Inventors: 大山姜; 載鎬沈
Original assignee: 住友化学株式会社
Priority date: 2020-03-05
Filing date: 2021-02-18
Publication date: 2021-09-10
Also published as: TW202134708A; JP2021140024A

Abstract

The purpose of the present invention is to provide an optical laminate in which cracks do not readily occur in a retardation layer even when the laminate is bent. The present invention provides an optical laminate which comprises a polarization layer, a first adhesive layer, and a back surface panel in this order, wherein the polarization layer has, from the side near the first adhesive layer, a retardation film and a linear polarizing plate, the retardation film has a retardation layer which contains a layer of a cured polymerizable liquid crystal compound, and the positions of the ends of the first adhesive layer in a direction perpendicular to the lamination direction are further outward than the positions of the ends of the retardation layer.

Description

Optical laminate

The present invention relates to an optical laminate.

Patent Document 1 describes a bendable circular polarizing plate including a polarizing element and a retardation film arranged on one side of the polarizing element. It is described that the retardation film contains a liquid crystal compound. Patent Document 1 describes that the flexibility of a circularly polarizing plate was evaluated by a cylindrical mandrel test Type 2 (a test in which a sample is wound around a metal cylinder).

Patent Document 2 describes an adhesive optical film having an optical film and an adhesive layer, and the adhesive layer having a portion inside the edge of the optical film. According to Patent Document 2, such an adhesive optical film is less likely to cause a phenomenon (glue chipping) in which the adhesive at the edge of the optical film falls off when the end of the film comes into contact with an object. It is stated that it is easy to prevent the adhesive from contaminating the surface of the optical film (glue stain).

WO2016 / 158300 Japanese Unexamined Patent Publication No. 2004-170907

It has been clarified that an optical laminate having a retardation layer composed of a cured layer of a polymerizable liquid crystal compound tends to crack in the retardation layer when repeatedly bent with a small bending radius. An object of the present invention is to provide an optical laminate in which cracks are less likely to occur in the retardation layer even when bent.

[1] A polarizing layer, a first adhesive layer, and a back plate are provided in this order.
The polarizing layer has a retardation film and a linear polarizing plate from the side close to the first pressure-sensitive adhesive layer, and the retardation film has a retardation layer including a layer in which a polymerizable liquid crystal compound is cured. ,
An optical laminate in which the position of the end portion of the first pressure-sensitive adhesive layer is outside the position of the end portion of the retardation layer in a direction orthogonal to the lamination direction.
[2] The distance between the position of the end portion of the first pressure-sensitive adhesive layer and the position of the end portion of the retardation layer in the direction orthogonal to the laminating direction is more than 0 μm and 50 μm or less [1]. ] Optical laminate.
[3] The optical laminate according to [1] or [2], wherein the thickness of the first pressure-sensitive adhesive layer is 10 μm or more.
[4] The optical laminate according to any one of [1] to [3], wherein the first pressure-sensitive adhesive layer is laminated in contact with the retardation layer.
[5] The back plate is a touch sensor layer, and is
The end face of the touch sensor layer is inclined to 80 ° or more and less than 90 ° with respect to the surface opposite to the surface on the first adhesive layer side, according to any one of [1] to [4]. Optical laminate.
[6] A second pressure-sensitive adhesive layer and a front plate are provided in this order on the side of the polarizing layer opposite to the first pressure-sensitive adhesive layer side.
The position of the end portion of the second pressure-sensitive adhesive layer in the direction orthogonal to the laminating direction is described in any one of [1] to [5], which is located inside the position of the end portion of the front plate. Optical laminate.
[7] A surface protective film is provided on the front plate on the side opposite to the polarizing layer side.
A third pressure-sensitive adhesive layer and a separate film are provided on the back plate on the side opposite to the polarizing layer side.
In the direction orthogonal to the laminating direction, the position of the end portion of the surface protective film is outside the position of the end portion of the first pressure-sensitive adhesive layer, and the position of the end portion of the separate film is the position of the first portion. The optical laminate according to [6], which is outside the position of the end portion of the pressure-sensitive adhesive layer.

According to the present invention, it is possible to provide an optical laminate in which cracks are less likely to occur in the retardation layer even when bent.

It is the schematic sectional drawing which shows an example of the optical laminated body of this invention. It is the schematic sectional drawing which shows an example of the optical laminated body of this invention. It is the schematic sectional drawing which shows an example of the optical laminated body of this invention. It is the schematic sectional drawing for demonstrating the position of the end portion of the pressure-sensitive adhesive layer. It is the schematic sectional drawing which shows an example of the manufacturing method of the optical laminated body of this invention.

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

<Optical laminate>
FIG. 1 is a schematic cross-sectional view showing an example of the optical laminate of the present invention. The optical laminate 100 shown in FIG. 1 includes a polarizing layer 2, a first adhesive layer 11, and a back plate 3 in this order. The polarizing layer 2 has a retardation layer 20 including a layer in which the polymerizable liquid crystal compound is cured and a linear polarizing plate 25 from the side close to the first pressure-sensitive adhesive layer 11, and both are bonded by the bonding layer 4. ing. The retardation layer 20 including a layer in which the polymerizable liquid crystal compound is cured constitutes a retardation film. The first pressure-sensitive adhesive layer 11 is laminated in contact with the retardation layer 20.

The optical laminate can be provided with a second pressure-sensitive adhesive layer and a front plate in this order on the side of the polarizing layer opposite to the first pressure-sensitive adhesive layer side. FIG. 2 is a schematic cross-sectional view showing an example of the optical laminate of the present invention. The optical laminate 200 shown in FIG. 2 includes a front plate 1, a second adhesive layer 12, a polarizing layer 2, a first adhesive layer 11, and a back plate 3 in this order. The polarizing layer 2 includes a first retardation layer 21 including a layer in which the polymerizable liquid crystal compound is cured and a second retardation layer 22 including a layer in which the polymerizable liquid crystal compound is cured from the side close to the first pressure-sensitive adhesive layer 11. It has a linear polarizing plate 25, and each layer is bonded by a bonding layer 4. The first retardation layer 21, the second retardation layer 22, and the bonding layer 4 for bonding both of them form a retardation film. In the optical laminate 200, the back plate 3 is a touch sensor layer, and includes a transparent conductive layer 31 and a resin film 32.

The optical laminate may be provided with a surface protective film on the side of the front plate opposite to the polarizing layer side, and may be provided with a third adhesive layer and a separate film on the side of the back plate opposite to the polarizing layer side. Can be done. FIG. 3 is a schematic cross-sectional view showing an example of the optical laminate of the present invention. The optical laminate 300 shown in FIG. 3 includes a surface protective film 40, a front plate 1, a second adhesive layer 12, a polarizing layer 2, a first adhesive layer 11, a back plate 3, a third adhesive layer 42, and a separate layer. The film 41 is provided in this order.

The optical laminate can include layers other than the layers shown in FIGS. 1 to 3. The optical laminate includes, for example, an impact-resistant film arranged between the front plate 1 and the polarizing layer 2, a resin film arranged on the side of the retardation film opposite to the linear polarizing plate 25 side, and the front plate 1 and polarized light. A colored layer arranged between the layer 2 and the layer 2 may be provided.

In the optical laminate of the present invention, the position of the end portion of the first pressure-sensitive adhesive layer is located outside the position of the end portion of the retardation layer in the direction orthogonal to the lamination direction. When the optical laminate is rectangular in plan view, the direction orthogonal to the stacking direction can preferably be a direction orthogonal to the stacking direction and orthogonal to any side of the optical laminate in plan view. As shown in FIG. 1, in a cross section orthogonal to the stacking direction, the first adhesive layer 11 is inside the line segment connecting the end of the lower surface of the retardation layer 20 and the end of the upper surface of the back plate 3. When not depressed, the position of the end of the first pressure-sensitive adhesive layer 11 means the outermost position 30 of the first pressure-sensitive adhesive layer 11. On the other hand, as shown in FIGS. 4A to 4D, in the cross section orthogonal to the stacking direction, the line segment connecting the lower end of the retardation layer 20 and the upper end of the back plate 3 is formed. When the first pressure-sensitive adhesive layer 11 has a portion recessed inward, the position of the end portion of the first pressure-sensitive adhesive layer 11 means the innermost position 30 of the first pressure-sensitive adhesive layer 11. Regarding the retardation layer, the outermost position of the retardation layer is defined as the position of the end portion of the retardation layer in the cross section orthogonal to the stacking direction.

When the retardation film has a plurality of retardation layers including a layer in which the polymerizable liquid crystal compound is cured, the position of the end portion of the retardation layer is arranged closest to the first pressure-sensitive adhesive layer in the lamination direction. It means the position of the end of the retardation layer. Specifically, the optical laminate 200 shown in FIG. 2 includes two retardation layers, a first retardation layer 21 and a second retardation layer 22. In this case, the position of the end portion of the retardation layer means the position of the end portion of the first retardation layer 21.

Since the position of the end portion of the first pressure-sensitive adhesive layer is outside the position of the end portion of the retardation layer in the direction orthogonal to the stacking direction, cracks occur in the retardation layer even if the first pressure-sensitive adhesive layer is bent. It becomes difficult. Since the first pressure-sensitive adhesive layer protrudes outward in the direction orthogonal to the stacking direction, the first pressure-sensitive adhesive layer is present directly below the retardation layer. It is presumed that the first pressure-sensitive adhesive layer functions as a support when the optical laminate is bent and can support the retardation layer, so that cracks are less likely to occur in the retardation layer. Therefore, it is preferable that the first pressure-sensitive adhesive layer is laminated in contact with the retardation layer.

As long as the first pressure-sensitive adhesive layer can support the retardation layer, the distance between the position of the end portion of the first pressure-sensitive adhesive layer and the position of the end portion of the retardation layer is not particularly limited. In one embodiment, the distance between the position of the end portion of the first pressure-sensitive adhesive layer and the position of the end portion of the retardation layer is preferably more than 0 μm and 50 μm or less in the direction orthogonal to the stacking direction. It is more preferably more than 0 μm and 30 μm or less, and may be 1 μm or more and 20 μm or less. Specifically, in the optical laminate 100 shown in FIG. 1, the distance between the position of the end portion of the first pressure-sensitive adhesive layer 11 and the position of the end portion of the retardation layer 20 corresponds to a distance of 50.

The shape of the end portion of the first pressure-sensitive adhesive layer is not particularly limited as long as the first pressure-sensitive adhesive layer can support the retardation layer. As shown in FIG. 1, in a cross section orthogonal to the stacking direction, the first adhesive layer 11 is outside the line segment connecting the end of the lower surface of the retardation layer 20 and the end of the upper surface of the back plate 3. It may be protruding.

In the direction orthogonal to the laminating direction, the position of the end portion of the second pressure-sensitive adhesive layer can be inside the position of the end portion of the front plate. The position of the end portion of the second pressure-sensitive adhesive layer can be determined in the same manner as the method of determining the position of the end portion of the first pressure-sensitive adhesive layer. That is, in the cross section orthogonal to the stacking direction, when the second adhesive layer is not depressed inward from the line segment connecting the lower end of the front plate and the upper end of the polarizing layer, the second adhesive is adhered. The position of the edge of the agent layer means the outermost position of the second pressure-sensitive adhesive layer. On the other hand, in a cross section orthogonal to the stacking direction, when the second adhesive layer has a portion recessed inward from the line segment connecting the end portion of the lower surface of the front plate and the end portion of the upper surface of the polarizing layer. The position of the end portion of the second pressure-sensitive adhesive layer means the innermost position of the second pressure-sensitive adhesive layer. Regarding the front plate, the outermost position of the front plate is defined as the position of the end portion of the front plate in the cross section orthogonal to the stacking direction.

In one embodiment, the distance between the position of the end portion of the second pressure-sensitive adhesive layer and the position of the end portion of the front plate in the direction orthogonal to the laminating direction may be 0 μm or more and 50 μm or less, and may be 0 μm. It may be super 30 μm or less, or 1 μm or more and 20 μm or less. Specifically, in the optical laminate 200 shown in FIG. 2, the distance between the position of the end portion of the second pressure-sensitive adhesive layer 12 and the position of the end portion of the front plate 1 corresponds to the distance 51.

In one embodiment, the end surface of the back plate is preferably inclined at 80 ° or more and less than 90 ° with respect to the surface of the back plate opposite to the surface on the first pressure-sensitive adhesive layer side, and is 85 ° or more and 90 °. More preferably, it is tilted below °. Although the reason is not clear, when the optical laminate has such an inclination angle, the flexibility is likely to be improved. The angle of inclination is the line segment passing through the end of the upper surface (the surface on the first adhesive layer side) of the back plate and the end of the lower surface (the surface opposite to the first adhesive layer side) of the back plate. It means the angle formed by the lower surface of the back plate. The angle of inclination corresponds to the angle 6 in FIG.

When the optical laminate is viewed from the lamination direction, that is, in the plan view of the optical laminate, the position of the end portion of the first pressure-sensitive adhesive layer of the optical laminate is higher than the position of the end portion of the retardation layer. It suffices to have a portion that is also on the outside in at least a part on the circumference thereof. In order to improve the flexibility, it is preferable that the portion where the position of the end portion of the first pressure-sensitive adhesive layer is outside the position of the end portion of the retardation layer is formed in the bent portion of the optical laminate. .. When the optical laminate is rectangular in a plan view, the portion where the position of the end portion of the first pressure-sensitive adhesive layer is outside the position of the end portion of the retardation layer is formed on the entire side including the bent portion. Is more preferable. The portion where the position of the end portion of the first pressure-sensitive adhesive layer is outside the position of the end portion of the retardation layer may be formed over the entire circumference of the optical laminate.

It is preferable that the optical laminate can be bent at least in the direction in which the polarizing layer 2 (front plate 1 in FIG. 2) is inside. Bending means that the polarizing layer 2 (or the front plate 1) can be bent inward without causing cracks. The optical laminate according to the present invention has excellent bending resistance.

The shape of the optical laminate in a plan view may be, for example, a rectangular shape, preferably a rectangular shape having a long side and a short side, and more preferably a rectangle. When the shape of the optical laminate in a plan view is rectangular, the length of the long side may be, for example, 10 mm to 1400 mm, preferably 50 mm to 600 mm. The length of the short side is, for example, 5 mm to 800 mm, preferably 30 mm to 500 mm, and more preferably 50 mm to 300 mm. Each layer constituting the optical laminate may have corners R-processed, end portions notched, or perforated.

The thickness of the optical laminate is not particularly limited because it varies depending on the function required for the optical laminate, the application of the laminate, etc., but is, for example, 20 μm to 1,000 μm, preferably 50 μm to 500 μm.

[Front plate]
The front plate 1 constitutes the outermost surface of the display device when viewed from the visual side. The material and thickness of the front plate 1 are not limited as long as it is a plate-like body capable of transmitting light, and the front plate 1 may be composed of only one layer or may be composed of two or more layers. Examples thereof include resin films and glass films. The front plate preferably has a resin film. The front plate 1 may be a laminate of a resin film and a glass film.

The thickness of the front plate 1 may be, for example, 30 to 200 μm, preferably 50 to 150 μm, and more preferably 50 to 100 μm.

When the front plate 1 has a resin film, the material thereof is, for example, an acrylic resin such as polymethyl (meth) acrylate and polyethyl (meth) acrylate; a polyolefin resin such as polyethylene, polypropylene, polymethylpentene and polystyrene; Cellular resins such as acetyl cellulose, acetyl cellulose butyrate, propionyl cellulose, butyryl cellulose and acetyl propionyl cellulose; polyvinyl chloride resins such as ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol and polyvinyl acetal. Pulmonate resins such as polysulfone and polyether sulfone; ketone resins such as polyether ketone and polyether ether ketone; polyetherimide; polycarbonate resin; polyester resin; polyimide resin; polyamideimide resin; and polyamide resin Examples include resin. These polymers can be used alone or in combination of two or more. Above all, from the viewpoint of improving strength and transparency, it is preferable to use a polycarbonate resin, a polyester resin, a polyimide resin, a polyamide-imide resin, or a polyamide resin.

The thickness of the resin film may be, for example, 10 to 100 μm, preferably 20 to 70 μm, and more preferably 30 to 60 μm.

The front plate 1 may be a film in which a hard coat layer is provided on at least one surface of the resin film to further improve the hardness. The hard coat layer may be formed on one surface of the resin film or may be formed on both surfaces. By providing the hard coat layer, it is possible to obtain a front plate having improved hardness and scratch resistance. The hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of the ultraviolet curable resin include acrylic resin, silicone resin, polyester resin, urethane resin, amide resin, epoxy resin and the like. The hard coat layer may contain additives to improve hardness. Additives are not limited, and examples thereof include inorganic fine particles, organic fine particles, and mixtures thereof.

When the front plate 1 has a glass film, tempered glass for a display is preferably used as the glass film. The thickness of the glass film may be, for example, 10 μm or more and 500 μm or less, and may be 20 μm or more and 100 μm or less. By using the glass film, the front plate 1 having excellent mechanical strength and surface hardness can be constructed.

When the optical laminate is used in the display device, the front plate 1 may have a function as a window film in the display device. The front plate 1 may further have a function as a touch sensor, a blue light cut function, a viewing angle adjusting function, and the like.

[Polarizing layer]
The polarizing layer has a retardation film and a linear polarizing plate from the side closer to the first pressure-sensitive adhesive layer. The polarizing layer may be a circular polarizing plate (including an elliptical polarizing plate). Since the circularly polarizing plate can absorb the external light reflected in the image display device, it is possible to impart a function as an antireflection film to the optical laminate.

[Linear polarizing plate]
The linear polarizing plate has a function of selectively transmitting linearly polarized light in a certain direction from unpolarized light rays such as natural light. The linearly polarizing plate contains a stretched film or stretched layer on which a dichroic dye is adsorbed, a cured product of a polymerizable liquid crystal compound, and a dichroic dye, and the dichroic dye is dispersed in the cured product of the polymerizable liquid crystal compound. , An oriented liquid crystal layer or the like can be provided as a polarizer. A linear polarizing plate using a liquid crystal layer as a polarizer is preferable because there is no limitation in the bending direction as compared with a stretched film or a stretched layer on which a dichroic dye is adsorbed.

(A polarizing film that is a stretched film or a stretched layer on which a dichroic dye is adsorbed)
The polarizer, which is a stretched film on which a dichroic dye is adsorbed, is usually obtained by uniaxially stretching the polyvinyl alcohol-based resin film and dyeing the polyvinyl alcohol-based resin film with a dichroic dye such as iodine. It can be produced through a step of adsorbing a dichroic dye, a step of treating a polyvinyl alcohol-based resin film on which a dichroic dye is adsorbed with an aqueous boric acid solution, and a step of washing with water after the treatment with the aqueous boric acid solution.

The thickness of the polarizer is usually 30 μm or less, preferably 18 μm or less, and more preferably 15 μm or less. Reducing the thickness of the polarizer is advantageous for thinning the optical laminate. The thickness of the polarizer is usually 1 μm or more, and may be, for example, 5 μm or more.

The polyvinyl alcohol-based resin is obtained by saponifying the polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith is used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acid compounds, olefin compounds, vinyl ether compounds, unsaturated sulfone compounds, and (meth) acrylamide compounds having an ammonium group. ..

The degree of saponification of the polyvinyl alcohol-based resin is usually about 85 mol% or more and 100 mol% or less, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and polyvinyl formal, polyvinyl acetal, and the like modified with aldehydes can also be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually 1000 or more and 10000 or less, preferably 1500 or more and 5000 or less.

The polarizer, which is a stretched layer on which a bicolor dye is adsorbed, is usually a step of applying a coating liquid containing the polyvinyl alcohol-based resin on a base film, a step of uniaxially stretching the obtained laminated film, and a uniaxial stretching. By dyeing the polyvinyl alcohol-based resin layer of the laminated film with a dichroic dye, the dichroic dye is adsorbed to form a polarizer, and the film on which the dichroic dye is adsorbed is coated with a boric acid aqueous solution. It can be produced through a step of treating and a step of washing with water after treatment with an aqueous boric acid solution. The base film used for forming the polarizer may be used as a protective layer for the polarizer. If necessary, the base film may be peeled off from the polarizer. The material and thickness of the base film may be the same as the material and thickness of the resin film described later.

The stretched film or the polarizing element which is the stretched layer on which the dichroic dye is adsorbed may be used as it is as a linear polarizing plate, or a resin film may be attached to one or both sides thereof and used as a linear polarizing plate. The thickness of the linearly polarizing plate is preferably 2 μm or more and 40 μm or less.

The resin film is, for example, a cyclopolyolefin resin film; a cellulose acetate resin film made of a resin such as triacetyl cellulose or diacetyl cellulose; a polyester resin film made of a resin such as polyethylene terephthalate, polyethylene naphthalate, or polybutylene terephthalate; a polycarbonate resin film. Examples of films known in the art such as resin films; (meth) acrylic resin films; polypropylene-based resin films can be mentioned. The polarizer and the protective layer can be laminated via a bonding layer described later.

The thickness of the resin film is, for example, 100 μm or less, preferably 80 μm or less, more preferably 60 μm or less, further preferably 40 μm or less, still more preferably 30 μm or less, and usually 10 μm or more. From the viewpoint of increasing the absorption rate of the laser, it is preferably 15 μm or more.

A hard coat layer may be formed on the resin film. The hard coat layer may be formed on one surface of the resin film or may be formed on both sides. By providing the hard coat layer, a thermoplastic resin film having improved hardness and scratch resistance can be obtained. The hard coat layer can be formed in the same manner as the hard coat layer formed on the resin film described above.

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

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

For the polarizing element, which is a liquid crystal layer, for example, a composition for forming a polarizing element containing a polymerizable liquid crystal compound and a dichroic dye is applied onto an alignment film formed on a base film, and the polymerizable liquid crystal compound is polymerized. It can be formed by curing. The base film used for forming the polarizer may be used as a protective layer for the polarizer. The material and thickness of the base film may be the same as the material and thickness of the resin film described above.

Examples of a composition for forming a polarizer containing a polymerizable liquid crystal compound and a dichroic dye, and a method for producing a polarizer using this composition include JP2013-37353A, JP2013-33249, and Japanese Patent Publication No. 2013-33249. Examples thereof include those described in Japanese Patent Publication No. 2017-83843. The composition for forming a polarizer further contains additives such as a solvent, a polymerization initiator, a cross-linking agent, a leveling agent, an antioxidant, a plasticizer, and a sensitizer, in addition to the polymerizable liquid crystal compound and the dichroic dye. You may be. Only one of these components may be used, or two or more of these components may be used in combination.

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

The thickness of the polarizing element, which is the liquid crystal layer, is usually 10 μm or less, preferably 0.5 μm or more and 8 μm or less, and more preferably 1 μm or more and 5 μm or less.

The polarizer, which is a liquid crystal layer, may be used as a linear polarizing plate without peeling and removing the base film, or may be used as a linear polarizing plate by peeling and removing the base film from the polarizer. The polarizing element, which is a liquid crystal layer, may be used as a linear polarizing plate by forming a protective layer on one side or both sides thereof. As the protective layer, the above-mentioned resin film can be used.

The polarizer, which is a liquid crystal layer, may have an overcoat layer on one side or both sides of the polarizer for the purpose of protecting the polarizer and the like. The overcoat layer can be formed, for example, by applying a material (composition) for forming the overcoat layer on the polarizer. Examples of the material constituting the overcoat layer include a photocurable resin and a water-soluble polymer. As a material constituting the overcoat layer, a (meth) acrylic resin, a polyvinyl alcohol-based resin, or the like can be used.

[Phase difference film]
The retardation film included in the polarizing layer may be composed of one retardation layer or may be a laminate of two or more retardation layers. The retardation film includes at least one retardation layer including a layer on which the polymerizable liquid crystal compound is cured. When the retardation film is a laminate of two retardation layers, it is preferable that each retardation layer is a retardation layer including a layer in which a polymerizable liquid crystal compound is cured. The retardation film is laminated on the side opposite to the front plate side of the polarizer. The retardation film may have an overcoat layer that protects the surface thereof, a base film that supports the retardation film, and the like.

The retardation film preferably includes a λ / 4 layer as the retardation layer, and may further include at least one of a λ / 2 layer and a positive C layer. The retardation layer may have an alignment film. When the retardation film has a retardation layer having a λ / 2 layer, the λ / 2 layer and the λ / 4 layer can be laminated in this order from the polarizer side. When the retardation film contains a retardation layer which is a positive C layer, the λ / 4 layer and the positive C layer may be laminated in order from the polarizer side, and the positive C layer and the λ / 4 layer may be laminated in order from the polarizer side. It may be laminated. In FIG. 2, the first retardation layer 21 can be a positive C layer, and the second retardation layer 22 can be a λ / 4 layer.

The thickness of the retardation layer is, for example, 0.1 μm or more and 10 μm or less, preferably 0.5 μm or more and 8 μm or less, and more preferably 1 μm or more and 6 μm or less. Since a thin retardation layer is prone to cracking due to bending, the present invention is particularly useful when the optical laminate includes a retardation layer having such a thickness.

The retardation layer may be formed from the resin film exemplified as the material of the protective layer, or may be formed from a layer in which the polymerizable liquid crystal compound is cured. The retardation layer may further include an alignment film. The retardation film may have a bonding layer for bonding the λ / 4 layer, the λ / 2 layer, and the positive C layer. The bonding layer can be formed from an adhesive layer or an adhesive layer, as will be described later.

When the polymerizable liquid crystal compound is cured to form a retardation layer, the retardation layer can be formed by applying a composition containing the polymerizable liquid crystal compound to a base film and curing it. An alignment film may be formed between the base film and the coating layer. The material and thickness of the base film may be the same as the material and thickness of the resin film. When a retardation layer is formed from a layer obtained by curing a polymerizable liquid crystal compound, the retardation layer may be incorporated into an optical laminate in the form of having an alignment film and a base film, and the retardation layer may be incorporated into an optical laminate. It is not necessary to have a base film. The retardation layer can be bonded to the linear polarizing plate via the bonding layer.

[Back plate]
As the back plate, a plate-like body capable of transmitting light, a component used in a normal display device, or the like can be used. The thickness of the back plate may be, for example, 5 μm or more and 2,000 μm or less, preferably 10 μm or more and 1,000 μm or less, and more preferably 15 μm or more and 500 μm or less.

The plate-like body used for the back plate may be composed of only one layer, may be composed of two or more layers, and may be formed from the material described in the front plate 1. Examples of the back plate include a resin film, a touch sensor layer, an organic EL display element, a liquid crystal display element, and the like.

[Touch sensor layer]
The touch sensor layer may have at least a transparent conductive layer and may further have a resin film. The touch sensor layer may include a transparent conductive layer 31 and a resin film 32 in this order from the front plate side. The touch sensor layer may also include the resin film 32 and the transparent conductive layer 31 in this order from the front plate side. The touch sensor layer does not have to have a resin film. The touch sensor layer may include a separation layer, a bonding layer, and a protective layer in addition to the transparent conductive layer 31 and the resin film 32.

The touch sensor layer is a sensor that can detect the position touched by the front plate 1, and the detection method is not limited as long as it has the transparent conductive layer 31 and the resin film 32. Examples of the touch sensor layer detection method include a resistive film method, a capacitance method, an optical sensor method, an ultrasonic method, an electromagnetic induction coupling method, and a surface acoustic wave method. Among them, the capacitance type touch sensor layer is preferably used in terms of low cost, fast reaction speed, and thin film formation.

The touch sensor layer preferably has a configuration including a resin film 32 and a transparent conductive layer 31 provided on the surface of the resin film 32 on the bonding layer side. In the configuration in which the transparent conductive layer 31 is provided on the surface of the resin film 32, the resin film 32 and the transparent conductive layer 31 may be in contact with each other (for example, by the first method described later). The manufactured touch sensor layer), the resin film 32 and the transparent conductive layer 31 may not be in contact with each other (for example, the touch sensor layer manufactured by the second method described later). The touch sensor layer may include a bonding layer, a separation layer, a protective layer, and the like, in addition to the resin film 32 and the transparent conductive layer 31. Examples of the bonding layer include an adhesive layer and an adhesive layer.

An example of the capacitance type touch sensor layer is composed of a resin film, a transparent conductive layer for position detection provided on the surface of the resin film, and a touch position detection circuit. In a display device provided with an optical laminate having a capacitance type touch sensor layer, when the surface of the front plate 1 is touched, the transparent conductive layer is grounded via the capacitance of the human body at the touched point. Will be done. The touch position detection circuit detects the grounding of the transparent conductive layer, and the touched position is detected.
By having a plurality of transparent conductive layers separated from each other, more detailed position detection becomes possible.

The transparent conductive layer may be a transparent conductive layer made of a metal oxide such as ITO, or may be a metal layer made of a metal such as aluminum, copper, silver, gold, or an alloy thereof.

The separation layer can be a layer formed on a substrate such as glass and for separating the transparent conductive layer formed on the separation layer from the substrate together with the separation layer. The separation layer is preferably an inorganic layer or an organic layer. Examples of the material forming the inorganic layer include silicon oxide. As the material for forming the organic material layer, for example, a (meth) acrylic resin composition, an epoxy resin composition, a polyimide resin composition, or the like can be used.

The touch sensor layer may include a protective layer that is in contact with the transparent conductive layer 31 and protects the conductive layer. The protective layer contains at least one of an organic insulating film and an inorganic insulating film, and these films can be formed by a spin coating method, a sputtering method, a vapor deposition method or the like.

The touch sensor layer can be manufactured, for example, as follows. In the first method, the resin film 32 is first laminated on the glass substrate via the bonding layer. A transparent conductive layer 31 patterned by photolithography is formed on the resin film 32. By applying heat, the glass substrate and the resin film 32 are separated to obtain a touch sensor layer composed of the transparent conductive layer 31 and the resin film 32.

In the second method, a separation layer is first formed on the glass substrate, and if necessary, a protective layer is formed on the separation layer. A transparent conductive layer 31 patterned by photolithography is formed on the separation layer (or protective layer). A peelable protective film is laminated on the transparent conductive layer 31, and the transparent conductive layer 31 to the separation layer are transferred to separate the glass substrate. By laminating the resin film 32 and the separating layer via the laminating layer and peeling off the peelable protective film, a touch having the transparent conductive layer 31, the separating layer, the laminating layer, and the resin film 32 in this order. A sensor layer is obtained.

Examples of the resin film 32 included in the touch sensor layer include resin films such as triacetyl cellulose, polyethylene terephthalate, polyethylene naphthalate, polyolefin, polycycloolefin, polycarbonate, polyether sulfone, polyarylate, polyimide, polyamide, and polystyrene.

The thickness of the resin film 32 of the touch sensor layer is preferably 50 μm or less, and more preferably 30 μm or less, from the viewpoint of easily forming an optical laminate having excellent bending resistance. The thickness of the resin film 32 included in the touch sensor layer is, for example, 10 μm or more.

[First adhesive layer, second adhesive layer, third adhesive layer]
The pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition containing a resin as a main component, such as (meth) acrylic-based, rubber-based, urethane-based, ester-based, silicone-based, and polyvinyl ether-based. Among them, a pressure-sensitive adhesive composition using a (meth) acrylic resin having excellent transparency, weather resistance, heat resistance and the like as a base polymer is preferable. The pressure-sensitive adhesive composition may be an active energy ray-curable type or a thermosetting type. The composition of the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the third pressure-sensitive adhesive layer may be the same as or different from each other. The thickness of the first pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer, and the third pressure-sensitive adhesive layer may be the same as or different from each other.

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

The pressure-sensitive adhesive composition can contain a cross-linking agent. The cross-linking agent is a divalent or higher metal ion that forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound that forms an amide bond with a carboxyl group; poly. Examples include epoxy compounds and polyols that form an ester bond with a carboxyl group; polyisocyanate compounds that form an amide bond with a carboxyl group. Of these, polyisocyanate compounds are preferable.

The pressure-sensitive adhesive composition includes fine particles for imparting light scattering, beads (resin beads, glass beads, etc.), glass fibers, resins other than the base polymer, pressure-sensitive adhesives, fillers (metal powders and other inorganic powders). Etc.), antioxidants, UV absorbers, dyes, pigments, colorants, antifoaming agents, corrosion inhibitors, photopolymerization initiators and other additives may be included.

It can be formed by applying an organic solvent diluent of the above pressure-sensitive adhesive composition on a substrate and drying it.

The storage elastic modulus of the pressure-sensitive adhesive layer at a temperature of 25 ° C. is preferably 0.005 to 1.0 MPa, more preferably 0.01 to 0.5 MPa, and preferably 0.01 to 0.2 MPa. Is even more preferable. The storage elastic modulus can be measured using a viscoelasticity measuring device (MCR-301, Antonio Par). A plurality of pressure-sensitive adhesive layers are laminated so as to have a thickness of 150 μm and bonded to a glass film. The measurement can be performed under the condition of a temperature rising rate of 5 ° C./min.

The thickness of the first pressure-sensitive adhesive layer is preferably 10 μm or more, and more preferably 20 μm or more, from the viewpoint of enhancing the function of supporting the retardation layer. The upper limit of the thickness of the first pressure-sensitive adhesive layer is not particularly limited, but may be 50 μm or less, or 40 μm or less.

The thickness of the second pressure-sensitive adhesive layer is preferably 10 μm or more, and more preferably 20 μm or more. The upper limit of the thickness of the first pressure-sensitive adhesive layer is not particularly limited, but may be 50 μm or less, or 40 μm or less.

The thickness of the third pressure-sensitive adhesive layer is preferably 10 μm or more, and more preferably 20 μm or more. The upper limit of the thickness of the first pressure-sensitive adhesive layer is not particularly limited, but may be 50 μm or less, or 40 μm or less.

The thickness of the pressure-sensitive adhesive layer refers to the thickness of the thickest part of the pressure-sensitive adhesive layer.

[Lated layer]
The laminating layer can be a layer composed of a pressure-sensitive adhesive or an adhesive. Each laminating layer may be made of the same material or different materials. When the retardation film has a plurality of retardation layers, the retardation layers may be bonded to each other with an adhesive layer or may be bonded with an adhesive layer. The linearly polarizing plate and the retardation film are preferably bonded with an adhesive layer. The bonding layer on which the transparent conductive layer 31 and the resin film 32 are laminated is preferably an adhesive layer.

As the pressure-sensitive adhesive layer constituting the bonding layer, the same pressure-sensitive adhesive layer as the above-mentioned first pressure-sensitive adhesive layer, second pressure-sensitive adhesive layer, or third pressure-sensitive adhesive layer can be used.

The adhesive can be formed by combining one or more of, for example, a water-based adhesive, an active energy ray-curable adhesive, and the like. Examples of the water-based adhesive include a polyvinyl alcohol-based resin aqueous solution, a water-based two-component urethane-based emulsion adhesive, and the like. The active energy ray-curable adhesive is an adhesive that cures by irradiating with active energy rays such as ultraviolet rays, and is, for example, an adhesive containing a polymerizable compound and a photopolymerizable initiator, and an adhesive containing a photoreactive resin. , Adhesives containing a binder resin and a photoreactive cross-linking agent, and the like. Examples of the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable acrylic monomer, and a photocurable urethane monomer, and oligomers derived from these monomers. Examples of the photopolymerization initiator include compounds containing substances that generate active species such as neutral radicals, anion radicals, and cationic radicals by irradiating them with active energy rays such as ultraviolet rays.

When the bonding layer is a pressure-sensitive adhesive layer, the thickness of the pressure-sensitive adhesive layer is preferably 1 μm or more and 30 μm or less, more preferably 2 μm or more and 20 μm, and 3 μm or more and 10 μm or less. When the bonding layer is an adhesive layer, the thickness of the adhesive layer is preferably 0.01 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 3 μm or less.

[Surface protection film]
The surface protective film is a film for protecting the surface of the polarizing layer or the front plate. Usually, when the surface protective film has an adhesive layer after the optical laminate with the surface protective film is attached to, for example, an image display element, the surface protective film is peeled off together with the adhesive layer. .. Therefore, the surface protective film can be detachably attached to the surface of the polarizing layer or the front plate.

The surface protective film can be composed of, for example, a resin film and an adhesive layer laminated on the resin film. The resin film is composed of, for example, a polyolefin resin such as a polyethylene resin, a polypropylene resin, and a cyclic polyolefin resin; a polyester resin such as polyethylene terephthalate and polyethylene naphthalate; a polycarbonate resin; and a (meth) acrylic resin. be able to. The base film may have a single-layer structure or a multi-layer structure. The pressure-sensitive adhesive layer can be composed of a (meth) acrylic pressure-sensitive adhesive, an epoxy-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, or the like. Further, the surface protective film may be a resin film having self-adhesiveness such as polypropylene resin and polyethylene resin. In this case, the surface protective film does not have an adhesive layer.

The thickness of the surface protective film can be, for example, 5 to 150 μm, preferably 10 to 100 μm, more preferably 20 to 75 μm, still more preferably 25 to 70 μm (for example, 60 μm or less, further 55 μm or less). Is. If the thickness of the surface protective film is less than 5 μm, the protection of the polarizing layer or the front plate may be insufficient, and it is disadvantageous in terms of handleability. If the thickness of the surface protective film exceeds 150 μm, it is disadvantageous in terms of thinning the optical laminate and reworkability of the surface protective film.

The position of the end portion of the surface protective film is preferably outside the position of the end portion of the first pressure-sensitive adhesive layer. With such a configuration, when the end portion of the first pressure-sensitive adhesive layer comes into contact with some object, a part of the first pressure-sensitive adhesive layer may fall off, or the first pressure-sensitive adhesive layer may touch the surface of the optical laminate. It can be prevented from becoming contaminated.

[Separate film]
The separate film is a film that is temporarily attached to protect the surface of the pressure-sensitive adhesive layer until it is attached to a display element (for example, a liquid crystal cell) or another optical member. The separate film is usually composed of a thermoplastic resin film having one surface subjected to a mold release treatment such as a silicone-based or fluorine-based mold release agent, and the mold release-treated surface is bonded to a third pressure-sensitive adhesive layer.

The thermoplastic resin constituting the separate film can be, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, or the like. The thickness of the separate film is, for example, 10 to 50 μm.

The position of the end portion of the separate film is preferably outside the position of the end portion of the first pressure-sensitive adhesive layer. With such a configuration, when the end portion of the first pressure-sensitive adhesive layer comes into contact with some object, a part of the first pressure-sensitive adhesive layer may fall off, or the first pressure-sensitive adhesive layer may touch the surface of the optical laminate. It can be prevented from becoming contaminated.

[Manufacturing method of optical laminate]
In the optical laminate of the present invention, a polarizing layer and a back plate are laminated via a first pressure-sensitive adhesive layer, and if necessary, a front plate, a second pressure-sensitive adhesive layer, a surface protective film, and a third pressure-sensitive adhesive are further laminated. It is manufactured by laminating layers and separate films and then cutting them into a predetermined shape. After cutting each member, the front plate, the second pressure-sensitive adhesive layer, the surface protective film, the third pressure-sensitive adhesive layer, and the separate film may be laminated. The end face may be polished after cutting, but it is not necessary to polish the adhesive layer because the adhesive layer is easily scraped by the polishing process. By cutting as follows, it is easy to obtain an optical laminate in which the position of the end portion of the adhesive layer and the inclination of the back plate are controlled.

As shown in FIG. 5, the laminated body 400 is fixed to the base 7 having a half-moon-shaped cross section along the shape of the base 7. Next, the laminated body 400 is cut into a predetermined shape by an appropriate cutting means 500 from above the table 7. When the laminate is cut using such a base 7, the position of the end portion of the first pressure-sensitive adhesive layer can be easily set to the outside of the position of the end portion of the retardation layer, and the position of the end portion of the second pressure-sensitive adhesive layer can be easily set. Is easier to set inside than the position of the edge of the front plate. By adjusting the cross-sectional shape of the base 7, the distance between the position of the end portion of the first pressure-sensitive adhesive layer and the position of the end portion of the retardation layer, the position of the end portion of the second pressure-sensitive adhesive layer, and the position of the end portion can be determined. It is also possible to adjust the distance between the position of the edge of the front plate.

When fixing the laminate 400 to the base 7, if the back plate side surface of the laminate is in contact with the surface of the base 7, the end surface of the back plate is the surface opposite to the surface on the first adhesive layer side. It is easy to incline it to 80 ° or more and less than 90 °. When the polarizing layer side surface (or front plate side surface) of the laminate is in contact with the surface of the base 7, the end portion of the back plate is 90 with respect to the surface opposite to the surface on the first adhesive layer side. Easy to incline above ° and below 130 °.

The cutting means is not particularly limited. Cutting means include lasers, blades and water jets. Blades include scissors, Thomson blades, Pinnacle blades.

As the laser, for example, a laser that emits a wavelength in the range of 200 nm to 11 μm is used. The laser may be a continuous wave (CW) laser or a pulsed laser. Examples of the laser include _{a gas laser such as a CO 2} laser, a solid-state laser such as a YAG laser, and a semiconductor laser. _{A CO 2} laser is preferable because it is easy to adapt to the absorption region of the laminate.

[Display device]
The optical laminate can be arranged, for example, on the display surface of the display panel to form a display device. When the optical laminate includes a surface protective film or a separate film, the optical laminate can be arranged on the display surface of the display panel after being peeled off to form a display device.
The optical laminate is particularly preferred for applications where it is applied to the display surface of a flexible display panel. The display device has an optical laminate arranged on the front surface (visual side) thereof and a display panel. The optical laminate and the display panel are laminated by a laminated layer. The bonding layer that laminates the optical laminate and the display panel can be an adhesive layer. The display panel may be configured to be foldable with the viewing side surface inside, or may be configured to be rotatable.
Specific examples of the display panel include a liquid crystal display element, an organic EL display element, an inorganic EL display element, a plasma display element, and a field emission type display element.

The display device can be used as a mobile device such as a smartphone or tablet, a television, a digital photo frame, an electronic signboard, a measuring instrument or an instrument, an office device, a medical device, a computer device, or the like.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. In this example, the unit "part" of the ratio of blending substances is based on weight unless otherwise specified.

[Position and distance of edges and tilt angle]
The position of the end of each layer, the distance between the positions of the ends, and the angle of inclination were determined from the SEM image of the cross section of the optical laminate.

[Bending test]
The bending test was performed at a temperature of 25 ° C. The optical laminate was installed in a bending tester (F1-2SV, manufactured by Forehu) in a flat state (not bent), and was bent so that the front plate side was on the inside. After that, it returned to the original flat state. When a series of operations was performed once, the number of times of bending was counted as one, and this bending operation was repeated. The bending speed was once per second.
The minimum bending radius at which cracks did not occur in the retardation layer even after repeating the bending operation 200,000 times was investigated. The results are shown as "bending radius" in Table 1.

[Front plate]
As the front plate, a polyimide (PI) film having a hard coat layer formed on one surface was used. The thickness of the polyimide film was 50 μm, and the thickness of the hard coat layer was 10 μm.

[Circular polarizing plate]
A photoalignment film was formed on the base film. A composition containing a dichroic dye and a polymerizable liquid crystal compound was applied onto a photoalignment film, oriented and cured to obtain a polarizer having a thickness of 2 μm. A 25 μm-thick triacetyl cellulose (TAC) film was attached onto the polarizer via an adhesive layer.
The base film was peeled off and an overcoat layer was formed on the exposed surface. The overcoat layer was formed by applying a resin composition containing polyvinyl alcohol and water and drying at a temperature of 80 ° C. for 3 minutes. The thickness of the overcoat layer was 1.0 μm.

A λ / 4 layer composed of a layer in which the polymerizable liquid crystal compound was cured and a positive C layer composed of a layer in which the polymerizable liquid crystal compound was cured were laminated via an ultraviolet curable adhesive to obtain a retardation film. The thickness of the λ / 4 layer was 2 μm, the thickness of the positive C layer was 3 μm, and the thickness of the ultraviolet curable adhesive layer was 1 μm.

A linearly polarizing plate and a retardation film were laminated via an acrylic pressure-sensitive adhesive layer to obtain a circularly polarizing plate. The thickness of the acrylic pressure-sensitive adhesive layer was 5 μm. The obtained circularly polarizing plate was a laminate having a TAC film, a polarizer, an overcoat layer, an adhesive layer, a λ / 4 layer, an adhesive layer, and a positive C layer in this order. The angle formed by the absorption axis of the polarizer and the slow axis of the λ / 4 layer was 45 °.

[Touch sensor layer]
A separation layer was formed on the glass substrate. A patterned transparent conductive layer was formed on the separation layer by photolithography. A peelable protective film was laminated on the transparent conductive layer, and the transparent conductive layer was transferred to the separation layer to separate the glass substrate. The total thickness of the separation layer and the transparent conductive layer was 7 μm.

[Example 1]
The front plate, the circularly polarizing plate, and the touch sensor layer were laminated with each other via an acrylic pressure-sensitive adhesive layer. The thickness of this acrylic pressure-sensitive adhesive layer was 25 μm. The front plate was laminated on the TAC film side of the circularly polarizing plate, and the touch sensor layer was laminated on the positive C layer side of the circularly polarizing plate. After laminating the touch sensor layer on the circularly polarizing plate, the peelable protective film laminated on the touch sensor layer was peeled off. In this way, a laminated body in which the front plate, the second pressure-sensitive adhesive layer, the circularly polarizing plate, the first pressure-sensitive adhesive layer, and the touch sensor layer were laminated in this order was produced.

The obtained laminate was fixed to a table 7 having a half-moon-shaped cross section as shown in FIG. When fixing the laminated body to the table 7, the surface of the laminated body on the touch sensor layer (back plate) side is in contact with the table 7. The laminated body was cut by irradiating the laminated body with the laser light emitted from the _{CO 2 laser from above the table 7.} The laser light was focused by the lens, and the focus was on the surface on the front plate side. The output of the laser light was 11 W, and the moving speed (cutting speed) of the laser light was 320 mm / s. The same operation was performed on the four sides to prepare a rectangular optical laminate.

[Example 2]
An optical laminate was produced in the same manner as in Example 1 except that the laminate was punched and cut with a blade instead of the CO _{2 laser.} As the blade, a single-edged blade having a blade angle of 30 ° was used.
The cutting speed was 0.1 m / s.

[Example 3]
An optical laminated body was produced in the same manner as in Example 1 except that the front plate side surface of the laminated body was in contact with the table 7 when the laminated body was fixed to the table 7. The laser light was focused by the lens, and the focus was on the surface on the touch sensor layer side.

[Example 4]
An optical laminated body was produced in the same manner as in Example 2 except that the front plate side surface of the laminated body was in contact with the table 7 when the laminated body was fixed to the table 7.

[Comparative Example 1]
The end face of the optical laminate obtained in Example 1 was polished with a rotating cutting blade. The amount to be cut by polishing is 0.5 mm, the rotation speed of the cutting blade is 4800 rpm, and the feed rate is 600 mm / min. And said.

[Comparative Example 2]
The end face of the optical laminate obtained in Example 3 was polished with a rotating cutting blade. The amount to be cut by polishing is 0.5 mm, the rotation speed of the cutting blade is 4800 rpm, and the feed rate is 600 mm / min. And said.

An optical laminate in which the position of the end portion of the first pressure-sensitive adhesive layer is outside the position of the end portion of the retardation layer in the direction orthogonal to the lamination direction has a small bending radius, and the phase difference even if repeatedly bent. It was difficult for the layer to crack.

1 ... front plate, 2 ... polarizing layer, 3 ... back plate, 4 ... bonding layer, 7 ... stand, 11 ... first adhesive layer, 12 ... second adhesive layer, 20 ... retardation layer, 21 ... th 1 retardation layer, 22 ... second retardation layer, 25 ... linear polarizing plate, 30 ... end position, 31 ... transparent conductive layer, 32 ... resin film, 40 ... surface protection film, 41 ... separate film, 42 ... Third adhesive layer, 100, 102 to 105 ... Optical laminate, 200 ... Optical laminate, 300 ... Optical laminate, 400 ... Laminate, 500 ... Cutting means

Claims

The polarizing layer, the first adhesive layer, and the back plate are provided in this order.
The polarizing layer has a retardation film and a linear polarizing plate from the side close to the first pressure-sensitive adhesive layer, and the retardation film has a retardation layer including a layer in which a polymerizable liquid crystal compound is cured. ,
An optical laminate in which the position of the end portion of the first pressure-sensitive adhesive layer is outside the position of the end portion of the retardation layer in a direction orthogonal to the lamination direction.
The optical according to claim 1, wherein the distance between the position of the end portion of the first pressure-sensitive adhesive layer and the position of the end portion of the retardation layer is more than 0 μm and 50 μm or less in the direction orthogonal to the stacking direction. Laminated body.
The optical laminate according to claim 1 or 2, wherein the thickness of the first pressure-sensitive adhesive layer is 10 μm or more.
The optical laminate according to any one of claims 1 to 3, wherein the first pressure-sensitive adhesive layer is laminated in contact with the retardation layer.
The back plate is a touch sensor layer and
The optics according to any one of claims 1 to 4, wherein the end surface of the touch sensor layer is inclined at 80 ° or more and less than 90 ° with respect to the surface opposite to the surface on the first pressure-sensitive adhesive layer side. Laminated body.
A second pressure-sensitive adhesive layer and a front plate are provided in this order on the side of the polarizing layer opposite to the first pressure-sensitive adhesive layer side.
The optical according to any one of claims 1 to 5, wherein the position of the end portion of the second pressure-sensitive adhesive layer is located inside the position of the end portion of the front surface plate in a direction orthogonal to the laminating direction. Laminated body.
A surface protective film is provided on the front plate on the side opposite to the polarizing layer side.
A third pressure-sensitive adhesive layer and a separate film are provided on the back plate on the side opposite to the polarizing layer side.
In the direction orthogonal to the laminating direction, the position of the end portion of the surface protective film is outside the position of the end portion of the first pressure-sensitive adhesive layer, and the position of the end portion of the separate film is the position of the first portion. The optical laminate according to claim 6, which is outside the position of the end portion of the pressure-sensitive adhesive layer.