WO2022137922A1

WO2022137922A1 - Production method for laminate equipped with surface protection film, and laminate

Info

Publication number: WO2022137922A1
Application number: PCT/JP2021/042519
Authority: WO
Inventors: 智之山口
Original assignee: 住友化学株式会社
Priority date: 2020-12-25
Filing date: 2021-11-19
Publication date: 2022-06-30
Also published as: JP2022102603A; TW202231476A

Abstract

[Problem] To provide: a production method for a laminate equipped with a surface protection film in which a surface protection film, a polarizer protection layer, a first adhesive layer, a polarizer, a second adhesive layer, and a cured liquid crystal layer are provided in this order and whereby it is possible to reduce curling; and a laminate for use in the production method. [Solution] Provided is a production method for a laminate equipped with a surface protection film including: a bonding step in which a surface protection film is peelably bonded to the polarizer protection layer side of a laminate provided with a polarizer protection layer, a first adhesive layer, a polarizer, a second adhesive layer, and a cured liquid crystal layer in this order and a laminate having the surface protection film bonded thereto is obtained; and a pressing step in which the laminate having the surface protection film bonded thereto is oriented in one direction, inserted between a pair of pressing rollers, made to pass between the pressing rollers, and thereby pressed. The pencil hardness of the surface polarizer protection layer on the opposite side from the polarizer is either 3B or softer than 3B. Also provided is a laminate used in the production method. [Selected drawing] None

Description

Manufacturing method of laminate with surface protection film and laminate

The present invention relates to a method for manufacturing a laminate with a surface protective film and a laminate that can be used thereof.

As an optical member used in a display device such as a liquid crystal display device or an organic EL display device, a polarizing plate in which a protective film is laminated on a polarizing element made of polyvinyl alcohol-based resin via an adhesive, or on a polarizing element and a base material. An optical film or the like in which a retardation film on which a retardation layer containing a cured product of a polymerizable liquid crystal compound is formed is laminated is known (Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2004-245925 Japanese Patent Application Laid-Open No. 2015-191142

The above-mentioned polarizing plate and optical film often have curl at the end, and even when a surface protection film is further attached to the curled polarizing plate or optical film, the curl remains.

INDUSTRIAL APPLICABILITY The present invention is a method for manufacturing a laminate with a surface protective film, which comprises a surface protective film, a polarizing element protective layer, a first adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal curable layer in this order. It is an object of the present invention to provide a method for producing a laminate with a surface protective film capable of reducing curl, and a laminate used in the method for producing the laminate.

The present invention provides the following method for manufacturing a laminate with a surface protective film and the laminate.
[1] A method for manufacturing a laminate with a surface protective film, which comprises a surface protective film and a laminate.
The laminate includes a polarizing element protective layer, a first adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal curing layer in this order.
A bonding step in which the surface protective film is detachably bonded to the polarizing element protective layer side of the laminated body to obtain a laminated body to which the surface protective film is bonded, and a lamination in which the surface protective film is bonded. Includes a pressing step in which the body is oriented in one direction, inserted between a pair of pressing rolls, and pressed by passing between the pressing rolls.
A method for producing a laminate with a surface protective film, wherein the pencil hardness of the surface of the polarizing element protective layer on the side opposite to the polarizing element is 3B or softer than 3B.
[2] The method for producing a laminate with a surface protective film according to [1], wherein the surface hardness of the pair of pressing rolls is 60 ° or more and 90 ° or less.
[3] The laminate with a surface protective film according to [1] or [2], wherein the pressure applied to the laminate to which the surface protective film is attached in the pressing step is 0.5 MPa or more and 1.0 MPa or less. Manufacturing method.
[4] With the surface protective film according to any one of [1] to [3], the tension of the laminate to which the surface protective film is attached is 0 N / m or more and 30 N / m or less in the pressing step. Method for manufacturing a laminate.
[5] A polarizing element protective layer, a first adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal curing layer are provided in this order.
The polarizing element protective layer has a hard coat layer on the side opposite to the polarizing element.
A laminate having a pencil hardness on the surface of the hardcourt layer of 3B or softer than 3B.
[6] The laminate according to [5], wherein the thickness of the laminate is 70 μm or less.
[7] The laminate according to [5] or [6], wherein any layer on the hard coat layer side of the polarizing element is ultraviolet absorbent.
[8] The laminate according to any one of [5] to [7], wherein any of the layers on the hardcourt layer side of the polarizing element has an absorbance of 0.5 or more at a wavelength of 410 nm.
[9] The laminate according to any one of [5] to [8], wherein the polarizing element contains a dichroic dye and a polyvinyl alcohol-based resin film.
[10] The liquid crystal curing layer includes a first liquid crystal curing retardation layer, a third adhesive layer, and a second liquid crystal curing retardation layer in this order from the second adhesive layer side [5] to The laminate according to any one of [9].
[11] A laminate with a surface protective film, which comprises the laminate according to any one of [5] to [10] and a surface protective film laminated on the hard coat layer side of the polarizing element protective layer.
[12] A circular polarizing plate comprising the laminate according to any one of [5] to [10].
[13] A laminate for a flexible image display device, which includes the laminate according to any one of [5] to [10] and a front plate or a touch sensor.

According to the present invention, a laminate with a surface protective film including a surface protective film, a polarizing element protective layer, a first adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal curing layer in this order. As a manufacturing method, it is possible to provide a method for manufacturing a laminated body with a surface protective film capable of reducing curl, and a laminated body used in the manufacturing method.

It is a side view schematically showing an example of the manufacturing method of the laminated body of this invention. It is a schematic sectional drawing which shows an example of the layer structure of a laminated body. It is a schematic sectional drawing which shows another example of the layer structure of a laminated body. It is a schematic sectional drawing which shows still another example of the layer structure of a laminated body. It is a schematic sectional drawing which shows another example of the layer structure of a laminated body. It is a schematic cross-sectional view which shows still another example of the layer structure of a laminated body. It is a schematic sectional drawing which shows an example of the layer structure of the laminated body for a flexible image display apparatus. It is a schematic diagram schematically showing the curl evaluation method of a laminated body.

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 scales are appropriately adjusted and shown in order to make each component easier to understand, and the scale of each component shown in the drawings does not necessarily match the scale of the actual component.

<Manufacturing method of laminated body>
The method for manufacturing a laminated body with a surface protective film according to one aspect of the present invention is a method for manufacturing a laminated body with a surface protective film including the surface protective film and the laminated body, and the laminated body includes a polarizing element protective layer and a first. A surface protective film is formed by providing a 1-adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal curing layer in this order, and a surface protective film is releasably bonded to the polarizing element protective layer side of the laminate. Pressing by inserting the laminated body with the bonded laminate in one direction between the pair of pressing rolls and passing between the pressing rolls in the bonding process to obtain the bonded laminate. Including the process. The pencil hardness of the surface of the polarizing element protective layer opposite to the polarizing element is 3B or softer than 3B.

The manufacturing method of the laminate with the surface protective film will be described below with reference to the drawings. In the method of manufacturing the laminate 14 with the surface protective film shown in FIG. 1, the surface protective film 11 is detachably attached to the polarizing element protective layer (not shown) side of the laminate 10, and the surface protective film is attached. By the bonding step of obtaining the laminated body, and by inserting the laminated body to which the surface protective film is bonded in one direction between the pair of

pressing rolls

12 and 13, and passing the laminated body between the

pressing rolls

12 and 13. Includes a pressing step of pressing.

[Laminate]
The laminate 10 includes a polarizing element protective layer, a first adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal curing layer in this order. The polarizing element protective layer preferably has a hard coat layer on the surface opposite to the polarizing element. The laminate 10, the stator protective layer, the first adhesive layer, the polarizing element, the second adhesive layer, the liquid crystal curing layer, and the hard coat layer will be described later in the laminate according to another aspect of the present invention. Is applied.

The laminated body 10 may have a long shape or a single leaf shape. The single-wafer-shaped laminate can be obtained by cutting from the long laminate. When the laminated body 10 has a single-wafer shape, the plan view shape of the laminated body 10 may be, for example, a square shape, preferably a square shape having a long side and a short side, and more preferably a rectangular shape. When the plan view shape of the laminated body 10 is rectangular, the length of the long side may be, for example, 10 mm or more and 1400 mm or less, preferably 50 mm or more and 600 mm or less. The length of the short side is, for example, 5 mm or more and 800 mm or less, preferably 30 mm or more and 500 mm or less, and more preferably 50 mm or more and 300 mm or less.

The thickness of the laminated body 10 is not particularly limited because it varies depending on the function required for the laminated body 10, the application of the laminated body 10, and the like, but may be, for example, 70 μm or less, preferably 60 μm or less, and more preferably 50 μm or less. be. The laminate 10 is usually 10 μm or more, and may be, for example, 20 μm or more.

The laminated body 10 can be used as an image display device. The image display device may be any such as a liquid crystal display device and an organic EL display device. The laminated body 10 may be arranged on the front side (visual recognition side) of the image display device, or may be arranged on the back side. When the laminate 10 is arranged on the front side of the image display device, it can be arranged so that the surface protective film 11 side is the outermost surface.

The laminated body 10 may be, for example, a laminated body having antireflection performance. Examples of the laminated body having antireflection performance include a circular polarizing plate. In the image display device, by providing a laminated body having antireflection performance on the front side of the image display device, it is possible to suppress a decrease in visibility due to reflection of external light.

[Pencil hardness]
In the laminate 10, the pencil hardness of the surface of the polarizing element protective layer on the opposite side of the polarizing element is 3B or softer than 3B. Pencil hardness can be measured according to the method described in the Examples section below.

Since the polarizing element protective layer has the above-mentioned pencil hardness, it is possible to reduce the curl of the laminate with the surface protective film after the pressing step. In a linear polarizing plate in which a protective film is laminated on a polarizing element via an adhesive, curling often occurs in the final product due to shrinkage of the polarizing element, tension balance at the time of bonding, and the like. Further, the cured product of the polymerizable liquid crystal compound in the retardation layer is generally obtained by ultraviolet curing in many cases, and after the base material is peeled off, it becomes a final product due to the shrinkage stress caused by the ultraviolet curing of the polymerizable liquid crystal compound. It may greatly affect the later curl. According to the present inventor, in a laminate with a surface protective film, which comprises a surface protective film, a polarizing element protective layer, a first adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal cured layer in this order. Manufactured by applying the bonding step and pressing step described later within the above range to the pencil hardness of the surface of the polarizing element protection layer on the side opposite to the polarizing element, that is, the surface on the side where the surface protective film of the polarizing element protection layer is bonded. By doing so, it was found that the laminate with the surface protective film can be manufactured while reducing the curl.

The curl generated in the laminated body 10 may be a normal curl or a reverse curl. In the present specification, the normal curl is a state in which the polarizing element protective layer side of the laminated body 10 is concave, and the reverse curl is a state in which the liquid crystal cured layer side of the laminated body 10 is concave. According to the manufacturing method of the present invention, it is possible to manufacture a laminated body with a surface protective film in which curl is reduced regardless of whether the curl is normal or reverse curl.
Further, the curl generated in the laminated body 10 is a curl generated so that the end portion of the laminate 10 in the direction parallel to the absorption axis direction is lifted (hereinafter, also referred to as a curl in the direction parallel to the absorption axis direction). It may be a curl (hereinafter, also referred to as a curl in a direction parallel to the transmission axis direction) generated so that the end portion of the laminate 10 in the direction parallel to the transmission axis direction is lifted. There may be. According to the manufacturing method of the present invention, it is possible to manufacture a laminated body with a surface protective film in which curl is reduced regardless of whether the curl is generated in the absorption axis direction or the transmission axis direction. Can be done.

[Surface protection film]
The surface protective film 11 is, for example, a surface protective film 11 composed of a base film and an adhesive layer laminated on the base film, such that the surface of the laminated body, particularly the laminated body, comes into contact with other objects. It is a film to protect it from being scratched. The surface protective film 11 can be peeled off by being bonded to the laminated body via the adhesive layer, and the surface protective film 11 has, for example, after the laminated body is bonded to an image display element or another optical member. The entire adhesive layer is peeled off and removed. The resin constituting the base film is, for example, a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate or polyethylene naphthalate, a polycarbonate resin, or a (meth) acrylic resin. It can be a thermoplastic resin such as. Of these, polyester-based resins are preferable. The pressure-sensitive adhesive layer can be composed of an 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, it may be composed of a resin layer having self-adhesiveness such as polypropylene-based resin and polyethylene-based resin.

In addition, in this specification, "(meth) acrylic resin" represents at least one selected from the group consisting of acrylic resin and methacrylic resin. The same applies to other terms with "(meta)".

The thickness of the surface protective film 11 is not particularly limited, but is preferably in the range of, for example, 20 μm or more and 200 μm or less. When the thickness of the base material is 20 μm or more, the strength tends to be easily imparted to the laminated body 10.

[Lasting process]
In the bonding step, the surface protective film 11 can be detachably bonded to the polarizing element protective layer side of the laminated body 10 to obtain a laminated body to which the surface protective film is bonded. As shown in FIG. 1, the laminated body 10 can be bonded by superimposing the laminated body 10 on the surface protective film 11 arranged on the glass plate 15 installed on the support base 16. By driving the pressing roll 12 that comes into contact with the laminated body 10, the laminated body 10 to which the surface protective film 11 is attached can be continuously conveyed while being pressed.

The tension of the laminated body 10 before the surface protective film 11 is bonded (hereinafter, also referred to as the tension before bonding the laminated body 10) may be, for example, 50 N / m or more and 110 N / m or less, preferably 60 N / m. It is 100 N / m or less. The pre-bonding tension of the laminated body 10 refers to the tension in the direction parallel to the direction in which the laminated body 10 is passed through the

pressing rolls

12 and 13.

The tension of the surface protective film 11 before bonding to the laminate 10 (hereinafter, also referred to as the tension before bonding of the surface protective film 11) may be, for example, 0 N / m or more and 20 N / m or less, preferably 0 N / m. It is m or more and 10 N / m or less. The pre-bonding tension of the surface protective film 11 refers to the tension in the direction parallel to the direction in which the surface protective film 11 is passed between the

pressing rolls

12 and 13.

When the laminated body 10 is curled in a direction parallel to the absorption axis direction described later, the direction indicated by the arrow in FIG. 1 (in the width direction of the

pressing rolls

12 and 13 when the surface protective film 11 is viewed from the thickness direction). The polarizing element and the surface protective film 11 can be bonded so that the direction perpendicular to the direction is the absorption axis direction of the polarizing element. Further, when the laminated body 10 is curled in a direction parallel to the transmission axis direction, the surface protective film 11 may be attached so that the direction indicated by the arrow in FIG. 1 is the transmission axis direction of the polarizing element. can.

In order to improve the adhesion, one or both of the bonded surfaces can be subjected to a surface activation treatment such as a corona treatment.

[Pressing process]
In the pressing step, the laminated body 10 to which the surface protective film 11 is attached is oriented in one direction, inserted between the pair of

pressing rolls

12 and 13, and pressed by passing between the

pressing rolls

12 and 13. The laminate 10 to which the surface protective film 11 is attached is inserted between the

pressing rolls

12 and 13 so that the absorption axis direction or the transmission axis direction of the polarizing element is perpendicular to the width direction of the

pressing rolls

12 and 13. The absorber is preferably inserted between the

pressing rolls

12 and 13 so that the direction of the absorption axis is perpendicular to the width direction of the

pressing rolls

12 and 13.

The surface hardness of the

pressing rolls

12 and 13 may be, for example, 60 ° or more and 90 ° or less, preferably 65 ° or more and 80 ° or less. The hardness of the

pressing rolls

12 and 13 can be measured by the method described in the column of Examples described later.

The materials forming the

pressing rolls

12 and 13 may be different from each other or the same, and examples thereof include rubber, metal, alloy, elastic metal, and a combination thereof. The material of the surface of the

pressing rolls

12 and 13 in contact with the surface protective film and the laminate may be different from the material of the inside of the surface thereof, and the materials of the surfaces of the

pressing rolls

12 and 13 are the same even if they are different from each other. It may be.

The rubber may be, for example, NBR (nitrile rubber), titan, urethane and silicon, EPDM (ethylene-propylene-diene rubber), etc., preferably NBR, titan and urethane, and more preferably NBR.

Examples of the metal include iron and aluminum. Examples of the alloy include stainless steel such as SUS304 (stainless steel containing 18% Cr and 8% Ni). When the material of the pressing roll is a metal and / or an alloy, it is preferable to perform surface treatment such as chrome plating, nickel plating, DLC (diamond-like carbon) for the purpose of improving corrosion resistance and scratch resistance. The surface treatment may be a single layer or a plurality of layers may be laminated.

The elastic metal means a structure in which the surface of an elastic body such as rubber or oil is covered with a metal layer having a thickness of 0.2 mm or more and 2 mm or less. Nickel, stainless steel, or the like can be used as the outermost metal layer of the elastic metal. It is preferable that the outermost metal layer of the elastic metal is also subjected to surface treatment such as chrome plating, nickel plating, DLC (diamond-like carbon) for the purpose of improving corrosion resistance and scratch resistance.

The diameters of the

pressing rolls

12 and 13 may be, for example, 50 mm or more and 90 mm or less, preferably 55 mm or more and 85 mm or less, and more preferably 60 mm or more and 80 mm or less.

The pressure (nip pressure) applied to the laminate 1 to which the surface protective film 11 is bonded by the pressing rolls 12 and 13 is, for example, 0.4 MPa or more and 1.2 MPa or less, preferably 0.6 MPa or more and 1.0 MPa or less. Is.

The tension of the laminate 10 to which the surface protective film 11 is bonded (hereinafter, also referred to as post-bonding tension) may be, for example, 0 N / m or more and 20 N / m or less, preferably 0 N / m or more and 10 N / m or less. Is. The post-bonding tension refers to the tension in the direction parallel to the direction in which the laminated body 10 to which the surface protective film 11 is bonded is passed between the pressing rolls.

[Laminate with surface protection film]
The laminated body 14 with a surface protective film can be used for an image display device. When the laminate 14 with a surface protective film is used in an image display device, the surface protective film 11 can be peeled off and removed.

When the laminate 14 with the surface protective film is attached to the front side of the image display device with the surface protective film 11 side as the outside, it becomes easy to reduce the occurrence of bonding errors and bubbles when the laminate 14 is attached to the image display device. From the viewpoint, it is preferable that no curl is generated or that positive curl is generated, and when curl is generated, the amount of curl is preferably small. Further, when the laminate 14 with the surface protective film is used on the back side of the image display device with the cured liquid crystal layer side as the outside, it is easy to reduce the generation of bonding errors and bubbles when bonding to the image display device. Therefore, it is preferable that no curl is generated or reverse curl is generated, and when curl is generated, the amount of curl is preferably small.

<Laminated body>
FIG. 2 is a schematic cross-sectional view showing an example of the layer structure of the laminated body according to another aspect of the present invention. The laminate 1 shown in FIG. 2 includes a polarizing element protective layer 101, a first adhesive layer 102, a polarizing element 103, a second adhesive layer 104, and a liquid crystal curing layer 105 in this order. The protective layer 101 has a hard coat layer 100 on the opposite side of the polarizing element 103. A polarizing plate protective layer 101 and a polarizing element 103 bonded to each other via the first adhesive layer 102 are also referred to as a linear polarizing plate.

The laminated body 1 may have a long shape or a single leaf shape. The single-wafer-shaped laminate can be obtained by cutting from the long laminate. When the laminated body 1 has a single-wafer shape, the plan view shape of the laminated body 1 may be, for example, a square shape, preferably a square shape having a long side and a short side, and more preferably a rectangular shape. When the plan view shape of the laminated body 1 is rectangular, the length of the long side may be, for example, 10 mm or more and 1400 mm or less, preferably 50 mm or more and 600 mm or less. The length of the short side is, for example, 5 mm or more and 800 mm or less, preferably 30 mm or more and 500 mm or less, and more preferably 50 mm or more and 300 mm or less.

The thickness of the laminated body 1 is not particularly limited because it varies depending on the function required for the laminated body 1, the application of the laminated body 1, and the like, but may be, for example, 70 μm or less, preferably 60 μm or less, and more preferably 50 μm or less. be. The laminate 1 is usually 10 μm or more, and may be, for example, 20 μm or more.

The laminated body 1 may be curled, may be a normal curl, or may be a reverse curl. Further, when the curl generated in the laminated body 1 is a rectangular polarizing plate, two of the four sides are in the absorption axis direction, and the remaining two sides are in the direction orthogonal to the absorption axis. It may be a curl (hereinafter, also referred to as a curl in a direction parallel to the absorption axis direction) generated so that the end portion of the polarizing element 103 of the laminate 1 in the direction parallel to the absorption axis direction is lifted, or the layered body. The curl (hereinafter, also referred to as a curl in the direction parallel to the transmission axis direction) may be generated so that the end portion of the polarizing element 103 of 1 in the direction parallel to the transmission axis direction is lifted.

The laminated body 1 can be used as an image display device. The image display device may be any such as a liquid crystal display device and an organic EL display device. The laminated body 1 may be arranged on the front side (visual recognition side) of the image display device, or may be arranged on the back side. When the laminate 1 is arranged on the front surface side of the image display device, it can be arranged so that the hard coat layer 100 side is the outermost surface.

The laminated body 1 may be, for example, a laminated body having antireflection performance. Examples of the laminated body having antireflection performance include a circular polarizing plate. In the image display device, by providing a laminated body having antireflection performance on the front side of the image display device, it is possible to suppress a decrease in visibility due to reflection of external light.

In the laminate 1, any layer on the hard coat layer 100 side may be ultraviolet-absorbing, and for example, at least one of the hard coat layer 100, the polarizing element protection layer 101, and the first adhesive layer 102 is ultraviolet-absorbing. May be.

In the laminate 1, any layer on the hard coat layer 100 side may have an absorbance of 0.5 or more at a wavelength of 410 nm, for example, among the hard coat layer 100, the polarizing element protection layer 101, and the first adhesive layer 102. At least one layer may have an absorbance of 0.5 or more at a wavelength of 410 nm.

[Hard coat layer]
The hard coat layer 100 is formed on the side opposite to the polarizing element 103 of the polarizing element protection layer 101. The hard coat layer can have a function of improving the hardness and scratch property of the polarizing element protective layer 101. The hardcoat layer can also have functions such as UV absorption, antiglare, antireflection, light diffusivity, antistatic, antifouling, and conductivity.

The pencil hardness of the surface of the hard coat layer 100 is 3B or softer than 3B. Since the polarizing element protective layer has the above-mentioned pencil hardness, curl tends to be easily reduced when the laminate is formed with a surface protective film. The pencil hardness can be measured according to the measuring method described in the column of Examples described later.

The hard coat layer 100 can be a layer containing a cured product of a composition for forming a hard coat layer containing an active energy ray-curable resin. Examples of the active energy ray-curable resin include acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, epoxy resins and the like.

The cured product of the composition for forming a hard coat layer can be obtained, for example, by applying the composition for forming a hard coat layer on the polarizing element protective layer 101, which is a thermoplastic resin film, and curing the composition. Further, a thermoplastic resin film provided with a commercially available hard coat layer can also be used. The composition for forming a hard coat layer may be, for example, a thermosetting composition, a cationic curable composition, a radical curable composition, or the like. The composition for forming a hard coat layer can contain, for example, a polymerizable monomer, a polymerization initiator, an additive, a solvent and the like. Additives include, for example, plasticizers, UV absorbers, infrared absorbers, colorants such as pigments and dyes, fluorescent whitening agents, dispersants, heat stabilizers, light stabilizers, antistatic agents, antioxidants, etc. Examples thereof include lubricants, surfactants, inorganic fine particles, organic fine particles, or mixtures thereof.

The thickness of the hard coat layer 100 may be, for example, 0.1 μm or more and 10 μm or less, preferably 1 μm or more and 5 μm or less.

[Polar protector protection layer]
The polarizing element protective layer 101 is a layer for protecting the surface of the polarizing element 103, particularly the polarizing element 103, and is arranged on one side or both sides of the polarizing element 103 via only the first adhesive layer 102 or directly. Can be The stator protective layer 101 is firmly laminated with the polarizing element 103 via the first adhesive layer 102. Normally, the polarizing element protection layer 101 and the polarizing element 102 are integrated via the first adhesive layer 102 so as not to be separated from each other. When the laminate 1 has the stator protective layer 101 on one side, the polarizing element protective layer 101 can be arranged so that the hard coat layer 100 is on the opposite side of the polarizing element. The stator protective layer 101 can be formed from, for example, a thermoplastic resin film. The stator protective layer 101 can be attached to the polarizing element 103 via the first adhesive layer 102.

The thermoplastic resin film may be, for example, a translucent, preferably optically transparent thermoplastic resin film, and examples thereof include a chain polyolefin resin (polyethylene resin, polypropylene resin, poly). Methylpentene resin, etc.), Cyclic polyolefin resin (Norbornen resin, etc.) and other polyolefin resins; Triacetyl cellulose and other cellulose resins; Polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate and other polyester resins; Polycarbonate resin Resins; ethylene-vinyl acetate resin; polystyrene resin; polyamide resin; polyetherimide resin; (meth) acrylic resin such as polymethyl (meth) acrylate resin; polyimide resin; polyether sulfone resin; polysulfone system Resins; polyvinyl chloride-based resins; polyvinylidene chloride-based resins; polyvinyl alcohol-based resins; polyvinyl acetal-based resins; polyether ketone-based resins; polyether ether ketone-based resins; polyether sulfone-based resins; polyamideimide-based resins, etc. Be done. The thermoplastic resin can be used alone or in combination of two or more. Among them, a triacetyl cellulose-based resin film, a cyclic polyolefin-based resin film, and a (meth) acrylic-based resin film are preferable from the viewpoint of strength and translucency.

The thickness of the thermoplastic resin film may be, for example, 30 μm or less, preferably 25 μm or less from the viewpoint of thinning, and usually 1 μm or more, preferably 5 μm or more, and further preferably 15 μm or more. .. The thermoplastic resin film may or may not have a phase difference.

[First adhesive layer]
The first adhesive layer 102 has a function of bonding the polarizing element protection layer 101 and the polarizing element 103. The adhesive used for the first adhesive layer 102 includes an active energy ray-curable adhesive such as an ultraviolet curable adhesive, an aqueous solution of a polyvinyl alcohol-based resin, an aqueous solution containing a cross-linking agent, and a urethane-based emulsion adhesive. Examples thereof include water-based adhesives such as agents. The ultraviolet curable adhesive may be a mixture of a radically polymerizable (meth) acrylic compound and a photoradical polymerization initiator, a mixture of a cationically polymerizable epoxy compound and a photocationic polymerization initiator, and the like. Further, a cationically polymerizable epoxy compound and a radically polymerizable (meth) acrylic compound may be used in combination, and a photocationic polymerization initiator and a photoradical polymerization initiator may be used in combination as an initiator. The thickness of the first adhesive layer 102 may be, for example, 0.1 μm or more and 5 μm or less.

When using an active energy ray-curable adhesive, the adhesive is cured by irradiating it with active energy rays after bonding. The light source of the active energy ray is not particularly limited, but an active energy ray (ultraviolet ray) having a emission distribution at a wavelength of 400 nm or less is preferable, and specifically, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a chemical lamp, Black light lamps, microwave-excited mercury lamps, metal halide lamps and the like are preferably used.

In order to improve the adhesiveness between the polarizing element protective layer 101 and the polarizing element 103, prior to the bonding of the polarizing element protective layer 101 and the polarizing element 103, the bonded surfaces are subjected to corona treatment, flame treatment, and plasma treatment. , UV irradiation treatment, primer coating treatment, keratinization treatment and other surface treatments may be performed.

[Polarizer]
The splitter 103 is a polarizing element having a property of absorbing linearly polarized light having a vibration plane parallel to the absorption axis and transmitting linear polarization having a vibration plane orthogonal to the absorption axis (parallel to the transmission axis). Can be done. The splitter 103 may further have one or both of the substrate and the alignment film described below.

Examples of the polarizing element 103 include a stretched film or a stretched layer on which a dichroic dye is adsorbed, or a film on which a dichroic dye is applied and cured. Specifically, iodine or a dichroic organic dye is used as the dichroic dye. For dichroic organic dyes, C.I. I. A dichroic direct dye composed of a disazo compound such as DIRECT RED 39 and a dichroic direct dye composed of a compound such as trisazo and tetrakisazo are included.

[A splitter that is a stretched film or stretched layer on which a dichroic dye is adsorbed]
A polarizing element, which is a stretched film having a dichroic dye adsorbed (hereinafter, may be abbreviated as “stretched film”), will be described. The stretched film on which the bicolor dye is adsorbed is usually a step of uniaxially stretching the polyvinyl alcohol-based resin film, and a step of dyeing the polyvinyl alcohol-based resin film with the bicolor dye to adsorb the bicolor dye. , And the polyvinyl alcohol-based resin film on which the bicolor dye is adsorbed can be produced through a step of treating with a boric acid aqueous solution and a step of washing with water after the treatment with the boric acid aqueous solution. The thickness of the polarizing element, which is a stretched film on which the dichroic dye is adsorbed, may be, for example, 2 μm or more and 40 μm or less.

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 acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth) acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol-based resin is usually 85 mol% or more and 100 mol% or less, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal 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.

A film made of such a polyvinyl alcohol-based resin is used as a raw film for a stretched film. The method for forming the film of the polyvinyl alcohol-based resin is not particularly limited, and the film can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film may be, for example, 10 μm or more and 150 μm or less.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before dyeing with a dichroic dye, at the same time as dyeing, or after dyeing. If the uniaxial stretching is performed after staining, the uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. It is also possible to perform uniaxial stretching at these multiple stages. In uniaxial stretching, rolls having different peripheral speeds may be uniaxially stretched, or thermal rolls may be used to uniaxially stretch the rolls. Further, the uniaxial stretching may be a dry stretching in which stretching is performed in the atmosphere, or a wet stretching in which the polyvinyl alcohol-based resin film is swollen using a solvent. The draw ratio is usually about 3 times or more and 8 times or less.

Dyeing of a polyvinyl alcohol-based resin film with a dichroic dye is performed, for example, by immersing the polyvinyl alcohol-based resin film in an aqueous solution containing the dichroic dye. Specifically, iodine or a dichroic organic dye is used as the dichroic dye. For dichroic organic dyes, C.I. I. A dichroic direct dye composed of a disazo compound such as DIRECT RED 39 and a dichroic direct dye composed of a compound such as trisazo and tetrakisazo are included. The polyvinyl alcohol-based resin film is preferably immersed in water before the dyeing treatment.

When iodine is used as a dichroic dye, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide and dyeing is usually adopted. The iodine content in this aqueous solution is usually 0.01 parts by mass or more and 1 part by mass or less per 100 parts by mass of water. The content of potassium iodide is usually 0.5 parts by mass or more and 20 parts by mass or less per 100 parts by mass of water. The temperature of the aqueous solution used for dyeing is usually 20 ° C. or higher and 40 ° C. or lower. The immersion time (staining time) in this aqueous solution is usually 20 seconds or more and 1,800 seconds or less.

On the other hand, when a dichroic organic dye is used as the dichroic dye, a method of immersing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye and dyeing is usually adopted. The content of the bicolor organic dye in this aqueous solution is usually 1 × 10 ^-4 parts by mass or more and 10 parts by mass or less, preferably 1 × 10 ^-3 parts by mass or more and 1 part by mass or less per 100 parts by mass of water. Yes, more preferably 1 × 10 ^-3 parts by mass or more and 1 × 10 ^-2 parts by mass or less. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing aid. The temperature of the dichroic dye aqueous solution used for dyeing is usually 20 ° C. or higher and 80 ° C. or lower. The immersion time (staining time) in this aqueous solution is usually 10 seconds or more and 1,800 seconds or less.

The boric acid treatment after dyeing with a dichroic dye can usually be performed by immersing the dyed polyvinyl alcohol-based resin film in a boric acid aqueous solution. The content of boric acid in this aqueous boric acid solution is usually 2 parts by mass or more and 15 parts by mass or less, preferably 5 parts by mass or more and 12 parts by mass or less, per 100 parts by mass of water. When iodine is used as the dichroic dye, this aqueous boric acid preferably contains potassium iodide, and the content of potassium iodide in that case is usually 0.1 mass by mass per 100 parts by mass of water. It is 5 parts by mass or more and 15 parts by mass or less, preferably 5 parts by mass or more and 12 parts by mass or less. The immersion time in the boric acid aqueous solution is usually 60 seconds or more and 1,200 seconds or less, preferably 150 seconds or more and 600 seconds or less, and more preferably 200 seconds or more and 400 seconds or less. The temperature of boric acid treatment is usually 50 ° C. or higher.
It is preferably 50 ° C. or higher and 85 ° C. or lower, and more preferably 60 ° C. or higher and 80 ° C. or lower.

The polyvinyl alcohol-based resin film after boric acid treatment is usually washed with water. The water washing treatment can be performed, for example, by immersing the boric acid-treated polyvinyl alcohol-based resin film in water. The temperature of water in the washing treatment is usually 5 ° C. or higher and 40 ° C. or lower. The immersion time is usually 1 second or more and 120 seconds or less.

After washing with water, a drying treatment is performed to obtain a stretched film on which a dichroic dye is adsorbed. The drying process can be performed using, for example, a hot air dryer or a far-infrared heater. The temperature of the drying treatment is usually 30 ° C. or higher and 100 ° C. or lower, preferably 50 ° C. or higher and 80 ° C. or lower. The drying treatment time is usually 60 seconds or more and 600 seconds or less, preferably 120 seconds or more and 600 seconds or less. By the drying treatment, the moisture content of the stretched film on which the dichroic dye is adsorbed is reduced to a practical level. The water content is usually 5% by mass or more and 20% by mass or less, preferably 8% by mass or more and 15% by mass or less. When the moisture content is less than 5% by mass, the flexibility of the stretched film on which the dichroic dye is adsorbed is lost, and the stretched film on which the dichroic dye is adsorbed is damaged or broken after drying. Sometimes. Further, if the water content exceeds 20% by mass, the thermal stability of the stretched film on which the dichroic dye is adsorbed may deteriorate.

Next, a polarizing element, which is a stretched layer on which a dichroic dye is adsorbed (hereinafter, may be abbreviated as “stretched layer”) will be described. The stretched layer on which the bicolor dye is adsorbed is usually a step of applying a coating liquid containing the above polyvinyl alcohol resin on a substrate to obtain a laminated film, a step of uniaxially stretching the obtained laminated film, and uniaxial stretching. The step of dyeing the polyvinyl alcohol-based resin layer of the laminated film with a bicolor dye and adsorbing it, the step of treating the film on which the bicolor dye is adsorbed with a boric acid aqueous solution, and washing with water after the treatment with a boric acid aqueous solution. It can be manufactured through a process.
As an example of the base material, the thermoplastic resin film exemplified in the description of the stator protective layer 101 is applied. The base material may be peeled off and removed from the stretched layer, or the base material may be used as the stator protective layer 101. The thickness of the base material may be, for example, 5 μm or more and 200 μm or less. When the base material is incorporated into the laminate 1, the thickness of the base material is preferably 30 μm or less.

[Polarizer, which is a film coated with a dichroic dye and cured]
As the film obtained by applying and curing the dichroic dye, for example, a composition containing a dichroic dye having a liquid crystal property or a composition containing a dichroic dye and a liquid crystal compound is applied to a substrate and cured. Examples include films containing objects.

As an example of the base material, the thermoplastic resin film exemplified in the description of the polarizing element protective layer 101 described later is applied. The base material may be peeled off and removed from the film coated with the dichroic dye and cured, or the base material may be used as the polarizing element protective layer 101. The thickness of the base material may be, for example, 5 μm or more and 200 μm or less. When the base material is incorporated into the laminate 1, the thickness of the base material is preferably 30 μm or less. The substrate may have a hardcourt layer, an antireflection layer or an antistatic layer on at least one surface. The hardcoat layer, antireflection layer and antistatic layer are formed only on the surface of the base material on the side where the cured product is not formed, or only on the surface of the base material on the side where the cured product is formed. You may.

It is preferable that the film coated with the dichroic dye and cured is thin, but if it is too thin, the strength is lowered and the processability tends to be inferior. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

Specific examples of the film coated with the dichroic dye and cured include those described in JP2013-37353A, JP2013-333249, and the like.

[Alignment film]
The alignment film can be arranged between the base material and the composition containing the dichroic dye having liquid crystallinity, or the layer of the cured product of the composition containing the dichroic dye and the liquid crystal compound. The alignment film has an orientation regulating force that aligns the liquid crystal layer formed on the liquid crystal layer in a desired direction. Examples of the alignment film include an orientation polymer layer formed of an orientation polymer, a photo-alignment polymer layer formed of a photo-alignment polymer, and a grub alignment film having an uneven pattern or a plurality of grubs (grooves) on the surface of the layer. Can be done. The thickness of the alignment film may be, for example, 10 nm or more and 500 nm or less, and preferably 10 nm or more and 200 nm or less.

The oriented polymer layer can be formed by applying a composition in which an oriented polymer is dissolved in a solvent to a base material to remove the solvent, and if necessary, rubbing treatment. In this case, in the oriented polymer layer formed of the oriented polymer, the orientation restricting force can be arbitrarily adjusted depending on the surface condition of the oriented polymer and the rubbing conditions.

The photo-oriented polymer layer can be formed by applying a composition containing a polymer or monomer having a photoreactive group and a solvent to a substrate and irradiating it with polarized light. In this case, the orientation restricting force can be arbitrarily adjusted in the photo-alignment polymer layer depending on the polarization irradiation conditions for the photo-alignment polymer.

The grub alignment film is, for example, a method of forming an uneven pattern by exposure and development through an exposure mask having a pattern-shaped slit on the surface of a photosensitive polyimide film, and is active on a plate-shaped master having a groove on the surface. A method of forming an uncured layer of an energy ray-curable resin and transferring this layer to a substrate for curing. An uncured layer of an active energy ray-curable resin is formed on the substrate, and the layer has irregularities. It can be formed by a method of forming irregularities and hardening by pressing a roll-shaped master having the above.

[Second adhesive layer]
The second adhesive layer 104 has a function of bonding the polarizing element 103 and the liquid crystal curing layer 105. The second adhesive layer 104 can be a pressure-sensitive adhesive layer usually formed of a pressure-sensitive pressure-sensitive adhesive (hereinafter, also referred to as a pressure-sensitive adhesive).

The thickness of the second adhesive layer 104 may be, for example, in the range of 1 μm or more and 50 μm or less, preferably 2 μm or more and 45 μm or less, more preferably 3 μm or more and 30 μm or less, and further preferably 5 μm or more and 20 μm or less.

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, rubber, urethane, ester, silicone, and polyvinyl ether. Among them, a pressure-sensitive adhesive composition using a (meth) acrylic resin as a base polymer is preferable from the viewpoint of transparency, weather resistance, heat resistance and storage elastic modulus. The pressure-sensitive adhesive composition may be an active energy ray-curable type or a thermosetting type.

Examples of the (meth) acrylic resin (base polymer) used in the pressure-sensitive adhesive composition include butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2- (meth) acrylate. A polymer or copolymer having one or more (meth) acrylic acid esters such as ethylhexyl as a monomer is preferably used. It is preferable that the base polymer is copolymerized with a polar monomer. Examples of the polar monomer include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylic acid, hydroxyethyl (meth) acrylic acid, (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 meth) acrylate.

The pressure-sensitive adhesive composition may contain only the above-mentioned base polymer, but usually further contains 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. Epoxy compounds and polyols that form an ester bond with a carboxyl group; polyisocyanate compounds that form an amide bond with a carboxyl group are exemplified. Of these, polyisocyanate compounds are preferable.

To form the pressure-sensitive adhesive layer, for example, the pressure-sensitive adhesive composition is dissolved or dispersed in an organic solvent such as toluene or ethyl acetate to prepare a pressure-sensitive adhesive liquid, which is directly applied to the target surface of the laminate to prepare the pressure-sensitive adhesive. By a method of forming a layer, a method of forming an adhesive layer in the form of a sheet on a separate film that has been subjected to a mold release treatment, and transferring it to a target surface of a polarizing element 103 or a liquid crystal curing layer 105, or the like. It can be carried out.

The separate film can be a film made of a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate, or the like. Of these, a stretched film of polyethylene terephthalate is preferable.

The pressure-sensitive adhesive layer contains optional components such as glass fibers, glass beads, resin beads, fillers composed of metal powder and other inorganic powders, pigments, colorants, antioxidants, ultraviolet absorbers, antistatic agents and the like. Can be done.

Examples of the antistatic agent include ionic compounds, conductive fine particles, conductive polymers and the like, and ionic compounds are preferably used.
The cation component constituting the ionic compound may be an inorganic cation or an organic cation.
Examples of the organic cation include pyridinium cation, imidazolium cation, ammonium cation, sulfonium cation, phosphonium cation, piperidinium cation, pyrrolidinium cation and the like, and examples of the inorganic cation include lithium ion and potassium ion.
On the other hand, the anion component constituting the ionic compound may be an inorganic anion or an organic anion, but an anion component containing a fluorine atom is preferable because it provides an ionic compound having excellent antistatic performance. As anion components containing a fluorine atom, hexafluorophosphate anion [(PF _6- ⁾ ], bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N- ^] anion, bis (fluorosulfonyl) imide anion [ (FSO ₂ ) ₂ N- ^] Anions and the like can be mentioned.

In order to improve the adhesiveness between the polarizing element 103 and the liquid crystal cured layer 105, prior to the bonding of the polarizing element 103 and the liquid crystal cured layer 105, the bonded surfaces are subjected to corona treatment, flame treatment, plasma treatment, and ultraviolet rays. Surface treatment such as irradiation treatment, primer coating treatment, and saponification treatment may be performed.

[LCD cured layer]
The liquid crystal curing layer 105 is laminated on the opposite side of the polarizing element 103 from the polarizing element protective layer 101 via the second adhesive layer 104. The liquid crystal cured layer 105 can be a liquid crystal cured retardation layer having the function of a retardation layer. Examples of the liquid crystal curable retardation layer include a positive A layer such as a λ / 4 layer and a λ / 2 layer, and a liquid crystal curable layer having a function such as a positive C layer. The liquid crystal curing layer 105 may further include an alignment layer and a base material described later.

The liquid crystal cured layer 105 is a layer of a cured product cured by polymerizing a polymerizable liquid crystal compound. The liquid crystal cured layer 105 may be one in which the polymerizable liquid crystal compounds are polymerized with each other in a liquid crystal oriented state. The polymerizable liquid crystal compound may be oriented in-plane or vertically. When the polymerizable liquid crystal compound is oriented in the plane, the liquid crystal cured layer 105 becomes a positive A layer showing an in-plane phase difference. When the polymerizable liquid crystal compound is vertically oriented, it becomes a positive C layer showing a phase difference in the thickness direction.
The polymerizable liquid crystal compound is a compound having a polymerizable group and can be in a liquid crystal state. The polymerizable liquid crystal compound is cured by the reaction between the polymerizable groups of the polymerizable liquid crystal compound and the polymerization of the polymerizable liquid crystal compound.

The type of the polymerizable liquid crystal compound is not particularly limited, but can be classified into a rod-shaped type (rod-shaped liquid crystal compound) and a disk-shaped type (disk-shaped liquid crystal compound, discotic liquid crystal compound) according to its shape. Further, there are a small molecule type and a high molecular type, respectively. The polymer generally means a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). Any polymerizable liquid crystal compound can be used in the present invention. Further, two or more kinds of rod-shaped liquid crystal compounds, two or more kinds of disk-shaped liquid crystal compounds, or a mixture of a rod-shaped liquid crystal compound and a disk-shaped liquid crystal compound may be used. As the rod-shaped liquid crystal compound, for example, the compound described in claim 1 of JP-A No. 11-513019 can be preferably used. As the disk-shaped liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 or paragraphs [0013]-[0108] of JP-A-2010-244033 are preferable. Can be used.

Two or more kinds of polymerizable liquid crystal compounds may be used in combination. In that case, at least one type has two or more polymerizable groups in the molecule. That is, the layer obtained by curing the polymerizable liquid crystal compound is preferably a layer formed by fixing a liquid crystal compound having a polymerizable group by polymerization. In this case, it is no longer necessary to exhibit liquid crystallinity after forming a layer.

The polymerizable liquid crystal compound has a polymerizable group capable of carrying out a polymerization reaction. As the polymerizable group, for example, a functional group capable of an addition polymerization reaction such as a polymerizable ethylenically unsaturated group or a ring-polymerizable group is preferable. More specifically, examples of the polymerizable group include (meth) acryloyl group, vinyl group, styryl group, allyl group and the like. Among them, the (meth) acryloyl group is preferable. The (meth) acryloyl group is a concept that includes both a meta-acryloyl group and an acryloyl group.

The liquid crystal property of the polymerizable liquid crystal compound may be a thermotropic liquid crystal or a lyotropic liquid crystal, and if the thermotropic liquid crystal is classified by order, it may be a nematic liquid crystal or a smectic liquid crystal.

The liquid crystal cured layer 105 can be formed by applying a composition containing a polymerizable liquid crystal compound (hereinafter, also referred to as a composition for forming a liquid crystal cured layer) onto, for example, an alignment layer and irradiating it with active energy rays. can. The composition for forming a liquid crystal cured layer may contain components other than the above-mentioned polymerizable liquid crystal compound. For example, it is preferable that the composition for forming a liquid crystal cured layer contains a polymerization initiator. As the polymerization initiator used, for example, a thermal polymerization initiator or a photopolymerization initiator is selected depending on the type of the polymerization reaction. For example, examples of the photopolymerization initiator include α-carbonyl compounds, acyloin ethers, α-hydrocarbon-substituted aromatic acyloin compounds, polynuclear quinone compounds, and combinations of triarylimidazole dimers and p-aminophenyl ketones. The amount of the polymerization initiator used is preferably 0.01% by mass or more and 20% by mass or less, and 0.5% by mass or more and 5% by mass or less, based on the total solid content in the coating liquid. Is more preferable. The cured product is a state in which the formed layer alone can exist independently without being deformed or flowed.

Further, the composition for forming a liquid crystal cured layer may contain a polymerizable monomer from the viewpoint of the uniformity of the coating film and the strength of the film. Examples of the polymerizable monomer include radically polymerizable or cationically polymerizable compounds. Among them, a polyfunctional radically polymerizable monomer is preferable.

The polymerizable monomer is preferably one that can be copolymerized with the above-mentioned polymerizable liquid crystal compound. The amount of the polymerizable monomer used is preferably 1% by mass or more and 50% by mass or less, and more preferably 2% by mass or more and 30% by mass or less, based on the total mass of the polymerizable liquid crystal compound.

Further, the composition for forming a liquid crystal cured layer may contain a surfactant from the viewpoint of the uniformity of the coating film and the strength of the film. Examples of the surfactant include conventionally known compounds. Among them, fluorine-based compounds are particularly preferable.

Further, the composition for forming a liquid crystal cured layer may contain a solvent, and an organic solvent is preferably used. Examples of the organic solvent include amide (eg, N, N-dimethylformamide), sulfoxide (eg, dimethyl sulfoxide), heterocyclic compound (eg, pyridine), hydrocarbon (eg, benzene, hexane), alkyl halide (eg, eg). , Chloroform, dichloromethane), esters (eg, methyl acetate, ethyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Among them, alkyl halides and ketones are preferable. Further, two or more kinds of organic solvents may be used in combination.

In addition, the composition for forming a liquid crystal cured layer includes vertical alignment promoters such as a polarizing element interface side vertical alignment agent and an air interface side vertical alignment agent, as well as a polarizing element interface side horizontal alignment agent and an air interface side horizontal alignment agent. Various alignment agents such as the horizontal alignment accelerator may be contained. Further, the composition for forming a liquid crystal cured layer may contain an adhesion improver, a plasticizer, a polymer and the like in addition to the above components.

The active energy ray includes ultraviolet rays, visible light, electron beams, and X-rays, and is preferably ultraviolet rays. Examples of the light source of the active energy ray include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excima laser, and a wavelength range. Examples thereof include LED light sources that emit light of 380 to 440 nm, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, and the like.

The irradiation intensity of ultraviolet rays is usually 100 mW / cm ² or more and 3,000 mW / cm ² or less in the case of ultraviolet B waves (wavelength range 280 nm or more and 310 nm or less). The ultraviolet irradiation intensity is preferably an intensity in a wavelength region effective for activating the cationic polymerization initiator or the radical polymerization initiator. The time for irradiating with ultraviolet rays is usually 0.1 seconds or more and 10 minutes or less, preferably 0.1 seconds or more and 5 minutes or less, more preferably 0.1 seconds or more and 3 minutes or less, and further preferably 0. . 1 second or more and 1 minute or less.

The ultraviolet rays can be irradiated once or in a plurality of times. Although it depends on the polymerization initiator used, the integrated light amount at a wavelength of 365 nm is preferably 700 mJ / cm ² or more, more preferably 1,100 mJ / cm ² or more, and 1,300 mJ / cm ² or more. It is more preferable to do so. The integrated light amount is advantageous for increasing the polymerization rate of the polymerizable liquid crystal compound constituting the liquid crystal cured layer 105 and improving the heat resistance. The integrated light amount at a wavelength of 365 nm is preferably 2,000 mJ / cm ² or less, and more preferably 1,800 mJ / cm ² or less. The integrated light intensity may lead to coloring of the liquid crystal cured layer 105.

The thickness of the liquid crystal curing layer 105 is preferably 0.5 μm or more. The thickness of the liquid crystal curing layer 105 is preferably 10 μm or less, and more preferably 5 μm or less. The above-mentioned upper limit value and lower limit value can be arbitrarily combined. When the thickness of the liquid crystal curing layer 105 is at least the above lower limit value, sufficient durability can be obtained. When the thickness of the liquid crystal curing layer 105 is not more than the upper limit value, it can contribute to the thinning of the laminated body 1. As the thickness of the liquid crystal curing layer 105, a desired in-plane retardation value of a layer giving a phase difference of λ / 4, a layer giving a phase difference of λ / 2, or a positive C layer, and a phase difference value in the thickness direction are obtained. Can be adjusted to be.

The liquid crystal curing layer 105 may be a stack of a plurality of liquid crystal curing retardation layers having different different retardation characteristics. When the liquid crystal curing layer 105 includes a plurality of liquid crystal curing retardation layers, the liquid crystal curing retardation layer may be two layers or three or more layers. Each liquid crystal curing retardation layer may be laminated using an adhesive layer, or a composition containing a polymerizable liquid crystal compound is applied to the surface of the already formed liquid crystal curing retardation layer and cured. May be good.
When the liquid crystal curing retardation layer is composed of a first liquid crystal curing retardation layer, a third adhesive layer, and a second liquid crystal curing retardation layer in order from the second adhesive layer 104 side, the first liquid crystal curing retardation layer is formed. Either one of the retardation layer and the second liquid crystal curing retardation layer may be a λ / 4 layer, preferably the first liquid crystal curing retardation layer is a λ / 4 layer and the second liquid crystal curing retardation layer is λ / 4. Two layers or a positive C layer.
When the liquid crystal curing retardation layer is composed of a first liquid crystal curing retardation layer, a third adhesive layer, and a second liquid crystal curing retardation layer in order from the second adhesive layer 104 side, the first liquid crystal curing retardation layer is formed. Either one of the retardation layer and the second liquid crystal curing retardation layer may be a λ / 2 layer, preferably the first liquid crystal curing retardation layer is a λ / 2 layer and the second liquid crystal curing retardation layer is λ / 2. There are 4 layers.
When the liquid crystal curing retardation layer is composed of a first liquid crystal curing retardation layer, a third adhesive layer, and a second liquid crystal curing retardation layer in order from the second adhesive layer 104 side, the first liquid crystal curing retardation layer is formed. Either one of the retardation layer and the second liquid crystal curing retardation layer may be a positive C layer, preferably the first liquid crystal curing retardation layer is a λ / 4 layer or a positive C layer, and the second liquid crystal curing retardation layer. Is a positive C layer or a λ / 4 layer.

The liquid crystal cured layer 105 may include an adhesive layer, a base material, and / or an alignment layer for orienting the polymerizable liquid crystal compound when forming the liquid crystal cured layer 105. When the liquid crystal cured layer 105 has a substrate, the substrate is usually removed when the liquid crystal cured layer 105 is attached to the linear polarizing plate.

Examples of the adhesive include an active energy ray-curable adhesive such as an ultraviolet curable adhesive, an aqueous solution of a polyvinyl alcohol-based resin or an aqueous solution containing a cross-linking agent, and a water-based adhesive such as a urethane-based emulsion adhesive. be able to. When the liquid crystal curing layer 105 includes two or more adhesive layers, the adhesives may be of the same type or different types. The thickness of the adhesive layer may be, for example, 0.1 μm or more and 15 μm or less.

When the liquid crystal cured layer 105 is a stack of a plurality of liquid crystal cured retardation layers, the thickness of the liquid crystal cured layer 105 may be, for example, 0.1 μm or more and 50 μm or less, preferably 1 μm or more and 30 μm or less, more preferably. Is 0.5 μm or more and 15 μm or less.

[Base material]
The layer containing the cured product of the polymerizable liquid crystal compound can be formed, for example, on the alignment layer provided on the substrate. The base material has a function of supporting the alignment layer and may be a long base material. This base material functions as a releasable support and can support a liquid crystal curing layer or an alignment layer for transfer. Further, it is preferable that the surface has an adhesive force that can be peeled off. Examples of the base material include a translucent, preferably optically transparent thermoplastic resin film. Examples of the thermoplastic resin film include those exemplified in the above description of the stator protective layer.

The base material may be subjected to various blocking prevention treatments. Examples of the blocking prevention treatment include an easy-adhesion treatment, a treatment of kneading a filler and the like, an embossing treatment (knurling treatment) and the like. By applying such a blocking prevention treatment to the base material, it is possible to effectively prevent the base materials from sticking to each other when the base material is wound, so-called blocking, and the productivity tends to be improved easily. be.

[Orientation layer]
The layer containing the cured product of the polymerizable liquid crystal compound is formed on the substrate via the alignment layer. That is, the base material and the alignment layer are laminated in this order, and the layer containing the cured product of the polymerizable liquid crystal compound is laminated on the alignment layer.

The alignment layer is not limited to the vertical alignment layer, and may be an alignment layer that horizontally aligns the molecular axis of the polymerizable liquid crystal compound, or may be an alignment layer that tiltly aligns the molecular axis of the polymerizable liquid crystal compound. .. The alignment layer has solvent resistance that does not dissolve due to coating of a composition containing a polymerizable liquid crystal compound, which will be described later, and heat resistance in heat treatment for removing the solvent and aligning the liquid crystal compound. preferable. Examples of the alignment layer include an alignment layer containing an orientation polymer, a photoalignment film, and a grub alignment layer in which an uneven pattern or a plurality of grooves are formed and oriented on the surface. The thickness of the oriented layer is usually in the range of 10 nm or more and 10,000 nm or less.

Further, the alignment layer has a function of supporting the liquid crystal curing layer 105 and may function as a releasable support. A liquid crystal curing layer for transfer can be supported, and the surface thereof may have an adhesive strength to the extent that it can be peeled off.

As the resin used for the alignment layer, a resin obtained by polymerizing a polymerizable compound is used. The polymerizable compound is a compound having a polymerizable group, and is usually a non-liquid crystalline non-liquid crystal compound that does not become a liquid crystal state. The polymerizable groups of the polymerizable compound react with each other to polymerize the polymerizable compound, thereby forming a resin. Such a resin is used as an alignment layer for orienting the polymerizable liquid crystal compound at the stage of forming the liquid crystal cured layer 105, and if it is not contained in the liquid crystal cured layer 105, it can be used as a material for a known oriented layer. The resin to be used is not particularly limited, and a cured product obtained by curing a conventionally known monofunctional or polyfunctional (meth) acrylate-based monomer under a polymerization initiator can be used. Specifically, examples of the (meth) acrylate-based monomer include 2-ethylhexyl acrylate, cyclohexyl acrylate, diethylene glycol mono2-ethylhexyl ether acrylate, diethylene glycol monophenyl ether acrylate, tetraethylene glycol monophenyl ether acrylate, and trimethyl propanetriacrylate. , Lauryl acrylate, lauryl methacrylate, isobornyl acrylate, isobornyl methacrylate, 2-phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, 2-hydroxypropyl acrylate, benzyl acrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl methacrylate, benzyl methacrylate. , Cyclohexyl methacrylate, methacrylic acid, urethane acrylate and the like can be exemplified. The resin may be one of these or a mixture of two or more.
The oriented layer can be peeled off together with the substrate before and after the step of forming the liquid crystal cured layer 105 and then laminating it with a linear polarizing plate or the like.

Further, the alignment layer can be included in the liquid crystal curing layer 105 for the purpose of improving the peelability from the substrate and imparting film strength to the liquid crystal curing layer 105. When the liquid crystal cured layer 105 contains an alignment layer, it is preferable to use a cured product obtained by curing a monofunctional or bifunctional (meth) acrylate-based monomer, an imide-based monomer, or a vinyl ether-based monomer as the resin used for the alignment layer.
Examples of the monofunctional (meth) acrylate-based monomer include alkyl (meth) acrylates having 4 to 16 carbon atoms, βcarboxyalkyl (meth) acrylates having 2 to 14 carbon atoms, and alkylated phenyl (meth) having 2 to 14 carbon atoms. Examples thereof include acrylates, methoxypolyethylene glycol (meth) acrylates, phenoxypolyethylene glycol (meth) acrylates and isobonyl (meth) acrylates.
Bifunctional (meth) acrylate-based monomers include 1,3-butanediol di (meth) acrylate; 1,3-butanediol (meth) acrylate; 1,6-hexanediol di (meth) acrylate; ethylene glycol di. (Meta) acrylate; Diethylene glycol di (meth) acrylate; Neopentyl glycol di (meth) acrylate; Triethylene glycol di (meth) acrylate; Tetraethylene glycol di (meth) acrylate; Polyethylene glycol diacrylate; Bisphenol A bis (acrylate) Loyloxyethyl) ether; ethoxylated bisphenol A di (meth) acrylate; propoxylated neopentyl glycol di (meth) acrylate; ethoxylated neopentyl glycol di (meth) acrylate, 3-methylpentanediol di (meth) acrylate, etc. Can be mentioned.
Examples of the imide-based resin obtained by curing the imide-based monomer include polyamide and polyimide. The imide-based resin may be one of these or a mixture of two or more.
Further, the resin forming the alignment layer may contain a monomer other than the monofunctional or bifunctional (meth) acrylate-based monomer, the imide-based monomer and the vinyl ether-based monomer, but the monofunctional or bifunctional (meth) The content ratio of the acrylate-based monomer, the imide-based monomer, and the vinyl ether-based monomer may be 50% by mass or more, preferably 55% by mass or more, and more preferably 60% by mass or more in the total monomer. ..

When the alignment layer is included in the liquid crystal cured layer 105, the thickness of the alignment layer is usually in the range of 10 nm or more and 10,000 nm or less, and when the orientation of the liquid crystal cured layer 105 is in-plane orientation with respect to the film surface, the alignment layer The thickness is preferably 10 nm or more and 1000 nm or less, and when the orientation of the liquid crystal cured layer 105 is perpendicular to the film surface, it is preferably 100 nm or more and 10,000 nm or less. When the thickness of the oriented layer is within the above range, the peelability of the base material can be improved and appropriate film strength can be imparted.

[Laminate with surface protection film]
The laminated body with a surface protective film includes the laminated body 1 and the surface protective film laminated on the hard coat layer 100 side of the polarizing element protective layer 101.

The surface protective film is peeled off together with the pressure-sensitive adhesive layer that the polarizing plate is attached to, for example, an image display element or another optical member.

The surface protective film is composed of, for example, a base film and an adhesive layer laminated on the base film. As for the pressure-sensitive adhesive layer, the above description of the bonded layer is applied. The resin constituting the base film is, 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 a thermoplastic resin such as a polycarbonate resin. be able to. A polyester resin such as polyethylene terephthalate is preferable.

The thickness of the surface protective film is not particularly limited, but is preferably in the range of, for example, 20 μm or more and 200 μm or less. When the thickness of the base material is 20 μm or more, the strength tends to be easily imparted to the laminated body 1.

[Laminate with adhesive layer]
In the laminated body 1, the pressure-sensitive adhesive layer may be arranged on the outermost surface on the liquid crystal curing layer 105 side. The pressure-sensitive adhesive layer can be a layer for attaching a touch sensor panel, an image display element, or the like to the laminated body 1. The pressure-sensitive adhesive layer is usually composed of a pressure-sensitive adhesive. As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer, a conventionally known pressure-sensitive adhesive can be used without particular limitation, and a pressure-sensitive adhesive having a base polymer such as an acrylic polymer, a urethane-based polymer, a silicone-based polymer, or a polyvinyl ether-based polymer can be used. Can be used. Further, it may be an active energy ray-curable pressure-sensitive adhesive, a thermosetting pressure-sensitive adhesive, or the like. The pressure-sensitive adhesive layer can have a separate film.

[Layer structure of laminated body]
FIG. 3 is a schematic cross-sectional view showing another example of the layer structure of the laminated body. The laminate 2 shown in FIG. 3 has a hard coat layer 100, a polarizing element protective layer 101, a first adhesive layer 102, a polarizing element 103, a second adhesive layer 104, and a first liquid crystal curing phase difference. A layer 111, a third adhesive layer 112, and a second liquid crystal curing retardation layer 113 are provided.

FIG. 4 is a schematic cross-sectional view showing still another example of the layer structure of the laminated body. The laminate 3 shown in FIG. 4 includes a surface protective film 114, a hard coat layer 100, a polarizing element protective layer 101, a first adhesive layer 102, a polarizing element 103, and a second adhesive layer 104. A first liquid crystal curing retardation layer 111, a third adhesive layer 112, and a second liquid crystal curing retardation layer 113 are provided.

FIG. 5 is a schematic cross-sectional view showing another example of the layer structure of the laminated body. The laminate 4 shown in FIG. 5 includes a hard coat layer 100, a polarizing element protective layer 101, a first adhesive layer 102, a polarizing element 103, a second adhesive layer 104, and a first liquid crystal curing phase difference. A layer 111, a third adhesive layer 112, a second liquid crystal curing retardation layer 113, an adhesive layer 115, and a separate film 116 are provided.

FIG. 6 is a schematic cross-sectional view showing still another example of the layer structure of the laminated body. The laminate 5 shown in FIG. 6 includes a surface protective film 114, a hard coat layer 100, a polarizing element protective layer 101, a first adhesive layer 102, a polarizing element 103, and a fourth adhesive layer 106. The polarizing element protective layer 107, the second adhesive layer 104, the first liquid crystal curing retardation layer 111, the third adhesive layer 112, the second liquid crystal curing retardation layer 113, the pressure-sensitive adhesive layer 115, and the separate A film 116 is provided.

[Manufacturing method of laminated body]
In the laminated body 1, for example, a polarizing element protective layer 101 provided with a hard coat layer 100 and a polarizing element 103 are bonded together via a first adhesive layer 102 to form a linear polarizing plate, and the linear polarizing plate and a liquid crystal display are formed. It can be manufactured by laminating the cured layer 105 with the second adhesive layer 104. In the case of bonding, it is preferable to apply a surface activation treatment such as corona treatment to one or both of the bonded surfaces in order to improve the adhesion.

The adhesive layer used for the second adhesive layer 104 can be prepared as an adhesive sheet. For the pressure-sensitive adhesive sheet, a pressure-sensitive adhesive solution is prepared by dissolving or dispersing the pressure-sensitive adhesive composition in an organic solvent such as toluene or ethyl acetate, and a layer made of the pressure-sensitive adhesive is formed on a release film which has been subjected to a mold release treatment. It can be produced by forming it into a sheet shape and laminating another release film on the pressure-sensitive adhesive layer. Each layer can be bonded by a method in which an adhesive sheet from which one release film has been peeled off is attached to one layer, then the other release film is peeled off, and the other layer is attached.

As a method of applying the adhesive liquid on the release film, a usual coating technique using a die coater, a comma coater, a reverse roll coater, a gravure coater, a rod coater, a wire bar coater, a doctor blade coater, an air doctor coater, etc. Should be adopted.

The release film is preferably composed of a plastic film and a release layer. Examples of the plastic film include polyester films such as polyethylene terephthalate film, polybutylene terephthalate film, and polyethylene naphthalate film, and polyolefin films such as polypropylene film. Further, the release layer can be formed from, for example, a composition for forming a release layer. The main component (resin) constituting the release layer forming composition is not particularly limited, and examples thereof include a silicone resin, an alkyd resin, an acrylic resin, and a long-chain alkyl resin.

<Image display device>
The laminate of the present invention can be used in an image display device. The image display device is a device having an image display panel, and includes a light emitting element or a light emitting device as a light emitting source. Examples of the image display device include a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, and the like. The laminate can be arranged on the visual side of the image display panel. The laminated body can be laminated on the image display device via the bonding layer.

<Laminate for flexible image display device>
The laminated body 1 can be a laminated body for a flexible image display device including a front plate described later on the visual recognition side of the laminated body 1 and a touch panel described later on the front plate side or the opposite side of the laminated body 1. The flexible image display device is composed of a laminate for a flexible image display device and an organic EL display panel, and the laminate for the flexible image display device is arranged on the visual side with respect to the organic EL display panel and is configured to be bendable. There is. The laminated body for the flexible image display device may include the laminated body 1 and one or both of the front plate and the touch panel, and the stacking order thereof is arbitrary, but the front plate (window) is viewed from the visual side. , The laminated body 1, the touch panel, or the front plate, the touch panel, and the laminated body 1 are preferably laminated in this order. When the laminated body 1 is present on the visual recognition side of the touch panel, the pattern of the touch panel is difficult to be visually recognized and the visibility of the displayed image is improved, which is preferable. Each member can be laminated using an adhesive, an adhesive, or the like. Further, it can be provided with a light-shielding pattern formed on at least one surface of any layer of the front plate, the laminated body 1, and the touch panel.

[Front plate]
A front plate may be arranged on the visible side of the laminated body 1. The front plate can be laminated on the laminated body 1 via the adhesive layer. Examples of the adhesive layer include the above-mentioned adhesive layer and adhesive layer.

Examples of the front plate include those having a hard coat layer on at least one surface of glass or a resin film. As the glass, for example, highly transparent glass or tempered glass can be used. Particularly when a thin transparent surface material is used, chemically strengthened glass is preferable. The thickness of the glass can be, for example, 20 μm or more and 5 mm or less.

The front plate including the hard coat layer on at least one surface of the resin film can have flexible characteristics instead of being rigid like existing glass. The thickness of the hard coat layer is not particularly limited, and may be, for example, 5 μm or more and 100 μm or less.

The resin film includes a cycloolefin derivative having a unit of a monomer containing a cycloolefin such as norbornene or a polycyclic norbornene-based monomer, and cellulose (diacetylcellulose, triacetylcellulose, acetylcellulosebutyrate, isobutylester cellulose). , Propionyl cellulose, butyryl cellulose, acetylpropionyl cellulose) ethylene-vinyl acetate copolymer, polycycloolefin, polyester, polystyrene, polyamide, polyetherimide, polyacrylic, polyimide, polyamideimide, polyethersulfone, polysulfone, polyethylene, Polypropylene, Polymethylpentene, Polyvinyl Chloride, Polyvinylidene Chloride, Polyvinyl Alcohol, Polyvinylacetal, Polyetherketone, Polyetheretherketone, Polyethersulne, Polymethylmethacrylate, Polyethyleneterephthalate, Polybutyleneterephthalate, Polyethylenenaphthalate, Polycarbonate , Polyurethane, epoxy and other polymers may be used. As the resin film, an unstretched uniaxial or biaxially stretched film can be used. Each of these polymers can be used alone or in combination of two or more. As the resin film, a polyamideimide film or a polyimide film having excellent transparency and heat resistance, a uniaxial or biaxially stretched polyester film, a cycloolefin derivative film having excellent transparency and heat resistance and being able to cope with an increase in the size of the film. , Polymethylmethacrylate films and triacetylcellulose and isobutylester cellulose films that are transparent and optically non-anisotropic are preferred. The thickness of the resin film may be 5 μm or more and 200 μm or less, preferably 20 μm or more and 100 μm or less.

[Shading pattern]
The light-shielding pattern (bezel) can be formed on the display element side of the front plate. The shading pattern can hide each wiring of the display device so that it cannot be seen by the user. The color and / or material of the light-shielding pattern is not particularly limited, and can be formed of a resin substance having various colors such as black, white, and gold. In one embodiment, the thickness of the light-shielding pattern may be 2 μm or more and 50 μm or less, preferably 4 μm or more and 30 μm or less, and more preferably 6 μm or more and 15 μm or less. Further, in order to suppress the mixing of air bubbles due to the step between the light-shielding pattern and the display unit and the visibility of the boundary portion, the light-shielding pattern can be given a shape.

[Touch panel]
The touch panel is used as an input means. As the touch sensor of the touch panel, various types such as a resistance film method, a surface acoustic wave method, an infrared ray method, an electromagnetic induction method, and a capacitance method have been proposed, and any method may be used. Of these, the capacitance method is preferable. It is divided into an active region of the capacitive touch sensor and an inactive region located in the outer portion of the active region. The active area is an area corresponding to the area where the screen is displayed on the display panel (display unit), the area where the user's touch is sensed, and the inactive area is the area where the screen is not displayed on the display device (non-active area). This is the area corresponding to the display unit). The touch panel has a substrate having flexible characteristics; a sensing pattern formed in an active region of the substrate; and a sensing pattern formed in an inactive region of the substrate to connect to an external drive circuit via the sensing pattern and a pad portion. Each sensing line of can be included. As the substrate having flexible characteristics, the same material as the transparent substrate of the front plate can be used.

The layer structure of the laminated body for the flexible image display device will be described with reference to FIG. 7. The laminated body 6 for a flexible image display device shown in FIG. 7 adheres to the laminated body 120, the front plate 121 on the visible side of the laminated body 120 via the adhesive layer 122, and the laminated body 120 on the side opposite to the visible side. A touch panel 123 is provided via the agent layer 115. The laminate 120 includes a hard coat layer 100, a polarizing element protective layer 101, a first adhesive layer 102, a polarizing element 103, a second adhesive layer 104, a first liquid crystal curing retardation layer 111, and a first layer. 3 The adhesive layer 112, the second liquid crystal curing retardation layer 113, and the pressure-sensitive adhesive layer 115 are provided.

Hereinafter, the present invention will be described in more detail by way of examples. Unless otherwise specified, "%" and "part" in the example are mass% and parts by mass.

[Measurement of pencil hardness]
JIS K 5600-5-4: 1999 "General paint test method-Part 5: Mechanical properties of coating film-Section 4: Scratch hardness (pencil method)" According to the pencil hardness test, the hard coat layer was applied. The hard coat layer side of the polarizing element protective layer having the metallizer was placed on a glass plate and measured. The pencil hardness 5B is softer than the pencil hardness 3B, and the pencil hardness 2B is harder than the pencil hardness 3B.

[Hardness of pressing roll]
The hardness [°] was measured at a temperature of 23 ° C. and a relative humidity of 50% using a type A durometer hardness tester (rubber hardness tester “Type-A” manufactured by Asuka Co., Ltd.) specified in JIS K 6253.

[Layer thickness]
The liquid crystal cured layer was measured using a contact type film thickness measuring device (“MS-5C” manufactured by Nikon Corporation).

[Example 1]
(Preparation of raw material laminate)
A linear splitter (thickness 8 μm) having iodine adsorbed and oriented on a polyvinyl alcohol-based resin film was prepared. A cyclic olefin resin (COP) film (thickness 25 μm) having a hard coat (HC) layer having a pencil hardness of 5B formed on one surface of the linear polarizing element via a first adhesive layer which is a water-based adhesive. ) (Hereinafter, sometimes referred to as "HC (A) -COP film"), the COP film side (the side opposite to the HC layer side) was bonded. A triacetyl cellulose (TAC) film (thickness 20 μm) as a substituent protective layer was bonded to the other surface of the linear polarizing element via a water-based adhesive. As a result, a linear polarizing plate was obtained. The linear polarizing plate was obtained by laminating an HC (A) -COP film (HC layer, COP film), a linear polarizing element, and a TAC film in this order. The HC (A) -COP film had a transmission property of 410 nm absorbance of 0.9.

Next, a λ / 4 plate (thickness 2 μm) which is a liquid crystal curing layer containing a cured product of a polymerizable liquid crystal compound, a third adhesive layer (thickness 2 μm) made of a cured product of an ultraviolet curable adhesive, and a polymerizable liquid crystal. A retardation layer in which positive C plates (thickness 3 μm), which are liquid crystal cured layers containing a cured product of the compound, were laminated in this order was prepared. The TAC film of the linear polarizing plate and the λ / 4 plate of the retardation layer were bonded by a second adhesive layer (thickness 15 μm) which was an adhesive layer. Subsequently, a pressure-sensitive adhesive layer with a release film was prepared by forming a pressure-sensitive adhesive layer (thickness 25 μm) formed on a release film (thickness 38 μm) using an acrylic pressure-sensitive adhesive. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer with a release film is bonded to the positive C plate side of the retardation layer bonded to the linear polarizing plate, and a rectangle having a long side length of 100 mm and a short side length of 100 mm is bonded. The raw material laminate was obtained by cutting into. The raw material laminate includes a linear polarizing plate (HC (A) -COP film, a first adhesive layer, a linear polarizing element, and a TAC film), a second adhesive layer which is an adhesive layer, and a retardation layer (λ / 4). A plate, a third adhesive layer, a positive C plate), and an adhesive layer with a release film (adhesive layer, release film) were laminated in this order. The thickness of the laminated portion of the raw material laminate from the linear polarizing plate (HC (A) -COP film, linear splitter, TAC film) to the pressure-sensitive adhesive layer with a release film (adhesive layer, release film) was 138 μm. rice field.

(Measurement of curl amount of raw material laminate)
A method of measuring the curl amount of the raw material laminate will be described with reference to FIG. The raw material laminate was left in an oven set to a furnace temperature of 80 ° C., and the curl amount was adjusted to be about the same in Examples and Comparative Examples. Reference surface 8 (horizontal table) with the raw material laminate 7 facing up on the concave side.
I put it on. In this state, the heights from the reference plane 8 were measured for each of the four angles a, b, c, and d of the raw material laminate 7, and the curl amount [mm] was obtained as the average of the four heights. The state in which the HC (A) -COP film side of the raw material laminate 7 is concave has a positive curl, and the state in which the HC (A) -COP film side of the raw material laminate 7 is convex. Is in a state of having a reverse curl. In Table 1, when the value of the curl amount is a positive value, it indicates that it is a positive curl, and when it is a negative value, it indicates that it is a reverse curl. The curl was generated at the end parallel to the absorption axis direction (in the direction of arrow A in FIG. 8) of the linear polarizing element. The results are shown in Table 1.

(Preparation of laminate with surface protection film)
An acrylic pressure-sensitive adhesive layer (thickness 15 μm) was formed on a polyester-based resin film (thickness 38 μm) on the HC surface on the HC (A) -COP film side of the raw material laminate after the curl amount was measured as described above. The acrylic pressure-sensitive adhesive layer side of the surface protective film (thickness 53 μm) was bonded, inserted between the pair of pressing rolls, and passed through the pressing rolls. As a result, a laminate with a surface protective film was obtained. As the pair of pressing rolls, one made of NBR (nitrile rubber) [hardness 70 °, roll diameter 70 mm] was used. Further, the pressure (nip pressure) applied to the laminate to which the surface protective film was attached by the pressing roll was 0.8 MPa. At this time, the pre-bonding tension of the raw material laminate in the absorption axis direction was 80 N / m, and the pre-bonding tension of the surface protective film was 0 N / m to 10 N / m. The tension after bonding was adjusted from 0 N / m to 10 N / m.

(Measurement of curl amount of laminate with surface protection film)
The curl amount of the obtained laminate with the surface protective film was measured according to the following method. The laminate with the surface protective film was placed on a reference surface (horizontal table) with the concave side facing up. Similar to the measurement of the curl amount of the raw material laminate, the height from the reference plane is measured for each of the four corners of the laminate with the surface protective film, and the curl amount [mm] is obtained as the average of the four heights. rice field. The state where the surface protective film side of the laminate with the surface protective film is concave has a positive curl, and the state where the surface protective film side of the laminate with the surface protective film is convex is a reverse curl. It is in a state of having. In Table 1, when the value of the curl amount is a positive value, it indicates that it is a positive curl, and when it is a negative value, it indicates that it is a reverse curl. The results are shown in Table 1. The curl occurred at the end parallel to the absorption axis of the linear transducer.

[Example 2]
(Preparation of raw material laminate)
A linear splitter (thickness 8 μm) in which iodine was adsorbed and oriented on a polyvinyl alcohol-based resin film was prepared. A cyclic olefin resin (COP) film (thickness 25 μm) having a hard coat (HC) layer having a pencil hardness of 5B formed on one surface of the linear polarizing element via a first adhesive layer which is a water-based adhesive. ) (Hereinafter, sometimes referred to as "HC (A) -COP film"), the COP film side (the side opposite to the HC layer side) was bonded. As a result, a linear polarizing plate was obtained. In this linear polarizing plate, an HC (A) -COP film (HC layer, COP film) and a linear polarizing layer were laminated in this order. The HC (A) -COP film had a transmission property of 410 nm absorbance of 0.9.

Next, a λ / 4 plate (thickness 2 μm) which is a liquid crystal curing layer containing a cured product of a polymerizable liquid crystal compound, a third adhesive layer (thickness 2 μm) made of a cured product of an ultraviolet curable adhesive, and polymerizable. A retardation layer in which a positive C plate (thickness 3 μm), which is a cured product layer of a liquid crystal compound, was laminated in this order was prepared. The linear polarizing element of the linear polarizing plate and the λ / 4 plate of the retardation layer were bonded by a second adhesive layer (thickness 5 μm) which was an adhesive layer. Subsequently, a pressure-sensitive adhesive layer with a release film was prepared by forming a pressure-sensitive adhesive layer (thickness 15 μm) formed on a release film (thickness 38 μm) using an acrylic pressure-sensitive adhesive. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer with a release film is bonded to the positive C plate side of the retardation layer bonded to the linear polarizing plate, and a rectangle having a long side length of 100 mm and a short side length of 100 mm is bonded. The raw material laminate was obtained by cutting into. The raw material laminate includes a linear polarizing plate (HC (A) -COP film, a first adhesive layer and a linear polarizing element), a second adhesive layer which is an adhesive layer, and a retardation layer (λ / 4 plate, a third plate). The adhesive layer (adhesive layer, positive C plate), and the pressure-sensitive adhesive layer with a release film (adhesive layer, release film) were laminated in this order. The thickness of the laminated portion of the raw material laminate from the linear polarizing plate (HC (A) -COP film, linear splitter, TAC film) to the pressure-sensitive adhesive layer with a release film (adhesive layer, release film) is 98 μm. rice field. With respect to the obtained raw material laminate, the curl amount of the raw material laminate was measured in the same manner as in Example 1, and then an optical laminate with a surface protective film was prepared and the curl amount was measured. The results are shown in Table 1.

[Comparative Example 1]
(Preparation of raw material laminate)
A linear splitter (thickness 8 μm) having iodine adsorbed and oriented on a polyvinyl alcohol-based resin film was prepared. A cyclic olefin resin (COP) film (thickness 25 μm) in which a hard coat (HC) layer having a pencil hardness of 2B is formed on one surface of the linear polarizing element via a first adhesive layer which is a water-based adhesive. ) (Hereinafter, sometimes referred to as "HC (B) -COP film"), the COP film side (the side opposite to the HC layer side) was bonded. A triacetyl cellulose (TAC) film (thickness 20 μm) as a substituent protective layer was bonded to the other surface of the linear polarizing element via a water-based adhesive. As a result, a linear polarizing plate was obtained. The linear polarizing plate was obtained by laminating an HC (B) -COP film (HC layer, COP film), a first adhesive layer, a linear polarizing element, and a TAC film in this order. The HC (B) -COP film had a transmission property of 410 nm absorbance of 0.1.

Next, a λ / 4 plate (thickness 2 μm) which is a cured product layer of the polymerizable liquid crystal compound, a third adhesive layer (thickness 2 μm) made of a cured product of an ultraviolet curable adhesive, and curing of the polymerizable liquid crystal compound. A retardation layer in which positive C plates (thickness 3 μm), which are physical layers, were laminated in this order was prepared. The TAC film of the polarizing plate with the surface protection film and the λ / 4 plate of the retardation layer were bonded by a second adhesive layer (thickness 15 μm) which was an adhesive layer. Subsequently, a pressure-sensitive adhesive layer with a release film was prepared by forming a pressure-sensitive adhesive layer (thickness 25 μm) formed on a release film (thickness 38 μm) using an acrylic pressure-sensitive adhesive. The pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer with a release film is bonded to the positive C plate side of the retardation layer bonded to the linear polarizing plate, and a rectangle having a long side length of 100 mm and a short side length of 100 mm is bonded. The raw material laminate was obtained by cutting into. The raw material laminate includes a linear polarizing plate (HC (B) -COP film, a first adhesive layer, a linear polarizing element, and a TAC film), a second adhesive layer which is an adhesive layer, and a retardation layer (λ / 4). A plate, a third adhesive layer, a positive C plate), and an adhesive layer with a release film (adhesive layer, release film) were laminated in this order. The thickness of the laminated portion from the linear polarizing plate (HC (B) -COP film, linear polarizing layer, TAC film) to the pressure-sensitive adhesive layer with a release film (adhesive layer, release film) in the raw material laminate is 138 μm. rice field. With respect to the obtained raw material laminate, the curl amount of the raw material laminate was measured in the same manner as in Example 1, and then an optical laminate with a surface protective film was prepared and the curl amount was measured. The results are shown in Table 1.

1,2,3,4,5,10,120 laminated body, 6 flexible image display device laminated body, 7 raw material laminated body, 8 reference plane, 11 surface protective film, 12,13 pressing roll, 14 with surface protective film Laminate, 15 glass plate, 16 support, 100 hard coat layer, 101, 107 polarizing element protective layer, 102 first adhesive layer, 103 polarizing element, 104
2nd Adhesive Layer, 105 LCD Curing Layer, 106 4th Adhesive Layer, 112 3rd Adhesive Layer, 111 1st LCD Curing Layer, 113 2nd LCD Curing Layer, 114 Surface Protective Film, 115
Adhesive layer, 116 separate film, 121 front plate, 122 adhesive layer, 123
Touch panel

Claims

A method for manufacturing a laminate with a surface protective film, which comprises a surface protective film and a laminate.
The laminate includes a polarizing element protective layer, a first adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal curing layer in this order.
A bonding step in which the surface protective film is detachably bonded to the polarizing element protective layer side of the laminated body to obtain a laminated body to which the surface protective film is bonded, and a lamination in which the surface protective film is bonded. Includes a pressing step in which the body is oriented in one direction, inserted between a pair of pressing rolls, and pressed by passing between the pressing rolls.
A method for producing a laminate with a surface protective film, wherein the pencil hardness of the surface of the polarizing element protective layer on the side opposite to the polarizing element is 3B or softer than 3B.
The method for manufacturing a laminate with a surface protective film according to claim 1, wherein the surface hardness of the pair of pressing rolls is 60 ° or more and 90 ° or less.
The method for manufacturing a laminate with a surface protective film according to claim 1 or 2, wherein in the pressing step, the pressure applied to the laminate to which the surface protective film is bonded is 0.5 MPa or more and 1.0 MPa or less.
The laminate with a surface protective film according to any one of claims 1 to 3, wherein in the pressing step, the tension of the laminate to which the surface protective film is attached is 0 N / m or more and 30 N / m or less. Production method.
A polarizing element protective layer, a first adhesive layer, a polarizing element, a second adhesive layer, and a liquid crystal curing layer are provided in this order.
The polarizing element protective layer has a hard coat layer on the side opposite to the polarizing element.
A laminate having a pencil hardness on the surface of the hardcourt layer of 3B or softer than 3B.
The laminate according to claim 5, wherein the thickness of the laminate is 70 μm or less.
The laminate according to claim 5 or 6, wherein any layer on the hard coat layer side of the polarizing element is ultraviolet absorbent.
The laminate according to any one of claims 5 to 7, wherein any layer on the hard coat layer side of the polarizing element has an absorbance of 0.5 or more at a wavelength of 410 nm.
The laminate according to any one of claims 5 to 8, wherein the polarizing element contains a dichroic dye and a polyvinyl alcohol-based resin film.
Any of claims 5 to 9, wherein the liquid crystal curing layer includes a first liquid crystal curing retardation layer, a third adhesive layer, and a second liquid crystal curing retardation layer in order from the second adhesive layer side. The laminated body according to one item.
A laminate with a surface protective film, which comprises the laminate according to any one of claims 5 to 10 and a surface protective film laminated on the hard coat layer side of the polarizing element protective layer.
A circular polarizing plate including the laminate according to any one of claims 5 to 10.
A laminate for a flexible image display device, which includes the laminate according to any one of claims 5 to 10 and a front plate or a touch sensor.