JP2021105713A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated body provided with a polarizing film and a retardation layer, having good adhesiveness between the polarizing film and the retardation layer, and having excellent durability.
SOLUTION: A polarizing film 11, a first cured product layer 12, and a first retardation layer 13 are laminated in this order, and the first cured product layer is a first active energy ray. The first active energy ray-curable composition contains a cured product of the curable composition, and contains (A) a cationically polymerizable compound and (B) a photocationic polymerization initiator, and the (B) photocationic polymerization initiator described above. Contains 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the cationically polymerizable compound (A), and the cationically polymerizable compound (A) contains 45 parts by mass of the oxetane compound based on the total mass of the cationically polymerizable compound (A). Laminated body containing% or more.
[Selection diagram] Fig. 1

Description

The present invention relates to a laminated body and further to an image display device including the laminated body.

In an image display device, a method is adopted in which an optical laminate having antireflection performance is arranged on the visual side of an image display panel to suppress a decrease in visibility due to reflection of external light.

As an optical laminate having antireflection performance, a laminate composed of a polarizing film and a retardation layer is known. Patent Document 1 proposes a laminate in which a polarizing film and a retardation layer are bonded by an adhesive layer made of an active energy ray-curable adhesive composition.

International Publication No. 2017/183333

In the laminate proposed in Patent Document 1, the adhesion between the polarizing film and the retardation layer is not sufficient, and the durability is also unsatisfactory.

An object of the present invention is to provide a laminate provided with a polarizing film and a retardation layer, having good adhesion between the polarizing film and the retardation layer, and having excellent durability.

（式中、Ｒ^１及びＲ^２は互いに独立に炭素数１〜６のアルキル基又は炭素数２〜１２のアルコキシアルキル基を表し、Ｒ^３は水素原子又は炭素数１〜６のアルキル基を表す）
で示されるアントラセン系化合物を含む、［１］に記載の積層体。
［３］ 前記オキセタン化合物は、３−エチル−３−ヒドロキシメチルオキセタン、キシリレンビスオキセタン、３−エチル−３−（フェノキシメチル）オキセタン、３−エチルー３{[(３−エチルオキセタン−３−イル)メトキシ]メチル}オキセタン、３−エチル−３−（２−エチルヘキシルオキシメチル）オキセタン、３−エチル−３−（シクロヘキシルオキシメチル）オキセタンからなる群から選択される少なくとも１種である、［１］又は［２］に記載の積層体。
［４］ 前記カチオン重合性化合物（Ａ）は、カチオン重合性化合物（Ａ）全質量を基準に脂環式エポキシ化合物を１０質量％以上５０質量％以下含む、［１］〜［３］のいずれかに記載の積層体。
［５］ 前記光カチオン重合開始剤（Ｂ）は、芳香族スルホニウム塩及び芳香族ヨードニウム塩からなる群から選択される少なくとも１種のイオン性化合物である、［１］〜［４］のいずれかに記載の積層体。
［６］ 前記第１活性エネルギー線硬化性組成物は、２５℃における粘度が２００ｍＰａ・ｓ以下である、［１］〜［５］のいずれかに記載の積層体。
［７］ 前記第１活性エネルギー線硬化性組成物は、下記式（１）を満たす［１］〜［６］のいずれかに記載の積層体。
（Ｊ_Ａ／Ｊ_Ｂ）×１００≧６０（％） （１）
［Ｊ_Ａは、波長３８０ｎｍにおける光線透過率が０％以上１０％以下であり、かつ波長４００ｎｍにおける光線透過率が３０％以上である基材を介して、第１活性エネルギー線硬化性組成物に波長３６５ｎｍにピークを有する紫外線を照射した際に示差走査熱量計により測定される熱量（単位：ｍＪ/ｇ）を表し、
Ｊ_Ｂは、基材を介さずに第１活性エネルギー線硬化性組成物に波長３６５ｎｍにピークを有する紫外線を照射した際に示差走査熱量計により測定される熱量（ｍＪ／ｇ）を表す。］
［８］ 前記第１硬化物層の８０℃における貯蔵弾性率は３００ＭＰａ以上である、［１］〜［７］のいずれかに記載の積層体。
［９］ 前記第１硬化物層の厚みは、０．５μｍ以上１０μｍ以下である、［１］〜［８］のいずれかに記載の積層体。
［１０］ 前記第１位相差層は、波長３８０ｎｍにおける光線透過率が０％以上５０％以下であり、かつ、波長４００ｎｍにおける光線透過率が３０％以上である、［１］〜［９］のいずれかに記載の積層体。
［１１］ 前記第１位相差層は、波長３８０ｎｍにおける光線透過率が０％以上１０％以下であり、かつ、波長４００ｎｍにおける光線透過率が３０％以上である、［１］〜［１０］のいずれかに記載の積層体。
［１２］ 前記第１位相差層の第１硬化物層とは反対側に、第２硬化物層と、第２位相差層とがこの順に積層され、
前記第２硬化物層は、第２活性エネルギー線硬化性組成物の硬化物を含み、前記第１位相差層及び前記第２位相差層の少なくとも一方は、波長３８０ｎｍにおける光線透過率が０％以上１０％以下であり、かつ、波長４００ｎｍにおける光線透過率が３０％以上である、［１］〜［１１］のいずれかに記載の積層体。
［１３］ 前記第１位相差層は１／２波長位相差層であり、前記第２位相差層は１／４波長位相差層である、［１２］に記載の積層体。
［１４］ 前記第１位相差層は１／２波長位相差層又は１／４波長位相差層であり、前記第２位相差層はポジティブＣプレートである、［１２］に記載の積層体。
［１５］ 前記第１位相差層及び前記第２位相差層の少なくとも一方は、位相差発現性の液晶層を含む、［１２］〜［１４］のいずれかに記載の積層体。
［１６］ 前記第１位相差層及び前記第２位相差層の少なくとも一方は、厚みが０．５μｍ以上５０μｍ以下である、［１２］〜［１５］のいずれかに記載の積層体。
［１７］ ［１］〜［１６］のいずれかに記載の積層体を含む円偏光板。
［１８］ 画像表示パネルと、前記画像表示パネルの視認側に配置された［１］〜［１７］のいずれかに記載の積層体とを含む、画像表示装置。
［１９］ 前記積層体は、前記偏光フィルムが視認側に位置する向きで配置されている、［１８］に記載の画像表示装置。
［２０］ ［１８］又は［１９］に記載の画像表示装置を含む有機エレクトロルミネッセンス表示装置。 The present invention provides the following [1] to [20].
[1] A laminate in which a polarizing film, a first cured product layer, and a first retardation layer are laminated in this order, the thickness of the first retardation layer is 10 μm or less, and the first curing The material layer contains a cured product of the first active energy ray-curable composition, and the first active energy ray-curable composition is
It contains (A) a cationically polymerizable compound and (B) a photocationic polymerization initiator.
The photocationic polymerization initiator (B) contains 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the cationically polymerizable compound (A).
The cationically polymerizable compound (A) is a laminate containing 45% by mass or more of an oxetane compound based on the total mass of the cationically polymerizable compound (A).
[2] The first active energy ray-curable composition is
(C) A photosensitizer exhibiting maximum absorption in light having a wavelength longer than 400 nm is contained in an amount of 0.1 part by mass or more and 3.0 part by mass or less with respect to 100 parts by mass of the cationically polymerizable compound (A).
The photosensitizer (C) has the following general formula (I):

(In the formula, R ¹ and R ² represent an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 12 carbon atoms independently of each other, and R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. )
The laminate according to [1], which contains an anthracene-based compound represented by.
[3] The oxetane compound is 3-ethyl-3-hydroxymethyloxetane, xylylenebis oxetane, 3-ethyl-3- (phenoxymethyl) oxetane, 3-ethyl-3 {[(3-ethyloxetane-3-yl). ) Methyl} oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, 3-ethyl-3- (cyclohexyloxymethyl) oxetane, at least one selected from the group, [1] Or the laminate according to [2].
[4] Any of [1] to [3], wherein the cationically polymerizable compound (A) contains 10% by mass or more and 50% by mass or less of an alicyclic epoxy compound based on the total mass of the cationically polymerizable compound (A). The laminate described in Crab.
[5] The photocationic polymerization initiator (B) is any one of [1] to [4], which is at least one ionic compound selected from the group consisting of aromatic sulfonium salts and aromatic iodonium salts. The laminate described in.
[6] The laminate according to any one of [1] to [5], wherein the first active energy ray-curable composition has a viscosity at 25 ° C. of 200 mPa · s or less.
[7] The first active energy ray-curable composition is a laminate according to any one of [1] to [6], which satisfies the following formula (1).
_{(J A / J B) ×} 100 ≧ 60 (%) (1)
_{[J A} is the light transmittance at a wavelength of 380nm is 10% or less than 0%, and light transmittance at a wavelength of 400nm is through the substrate is 30% or more, the first active energy ray-curable composition It represents the amount of heat (unit: mJ / g) measured by a differential scanning calorimeter when irradiated with ultraviolet rays having a peak at a wavelength of 365 nm.
J _B represents the amount of heat (mJ / g) measured by a differential scanning calorimeter when the first active energy ray-curable composition is irradiated with ultraviolet rays having a peak at a wavelength of 365 nm without using a substrate. ]
[8] The laminate according to any one of [1] to [7], wherein the first cured product layer has a storage elastic modulus of 300 MPa or more at 80 ° C.
[9] The laminate according to any one of [1] to [8], wherein the thickness of the first cured product layer is 0.5 μm or more and 10 μm or less.
[10] The first retardation layer has a light transmittance of 0% or more and 50% or less at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm, according to [1] to [9]. The laminate according to any one.
[11] Of [1] to [10], the first retardation layer has a light transmittance of 0% or more and 10% or less at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm. The laminate according to any one.
[12] The second cured product layer and the second cured product layer are laminated in this order on the side of the first retardation layer opposite to the first cured product layer.
The second cured product layer contains a cured product of the second active energy ray-curable composition, and at least one of the first retardation layer and the second retardation layer has a light transmittance of 0% at a wavelength of 380 nm. The laminate according to any one of [1] to [11], which is 10% or less and has a light transmittance of 30% or more at a wavelength of 400 nm.
[13] The laminate according to [12], wherein the first retardation layer is a 1/2 wavelength retardation layer, and the second retardation layer is a 1/4 wavelength retardation layer.
[14] The laminate according to [12], wherein the first retardation layer is a 1/2 wavelength retardation layer or a 1/4 wavelength retardation layer, and the second retardation layer is a positive C plate.
[15] The laminate according to any one of [12] to [14], wherein at least one of the first retardation layer and the second retardation layer includes a liquid crystal layer exhibiting retardation.
[16] The laminate according to any one of [12] to [15], wherein at least one of the first retardation layer and the second retardation layer has a thickness of 0.5 μm or more and 50 μm or less.
[17] A circularly polarizing plate containing the laminate according to any one of [1] to [16].
[18] An image display device including the image display panel and the laminate according to any one of [1] to [17] arranged on the visual side of the image display panel.
[19] The image display device according to [18], wherein the laminated body is arranged so that the polarizing film is located on the viewing side.
[20] An organic electroluminescence display device including the image display device according to [18] or [19].

According to the present invention, it is possible to provide a laminate provided with a polarizing film and a retardation layer, having good adhesion between the polarizing film and the retardation layer, and having excellent durability.

It is the schematic sectional drawing which shows typically the laminated body of this invention. It is the schematic sectional drawing which shows typically the retardation layer. It is the schematic sectional drawing which shows typically the laminated body of this invention. It is the schematic cross-sectional view which shows typically an example of each manufacturing process in the manufacturing 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 scale is appropriately adjusted to make it easier to understand each component, and the scale of each component shown in the drawings does not necessarily match the scale of the actual component.

<Laminated body>
The laminate of the present invention will be described with reference to FIG. In the laminated body 100 shown in FIG. 1, the polarizing film 11, the first cured product layer 12, and the first retardation layer 13 are laminated in this order.
The thickness of the laminate 100 may be, for example, 3 μm or more and 100 μm, preferably 3 μm or more and 60 μm or less.

The laminated body 100 may have a long shape or a single leaf shape. When the laminated body 100 has a single-wafer shape, the shape of the laminated body 100 in a plan view can be substantially rectangular. The plan view means that the laminated body 100 is viewed from the thickness direction. A substantially rectangular shape is a shape in which at least one of the four corners (corners) is cut off so as to have an obtuse angle, a shape having a rounded shape, or a part of an end face in a plan view. Has a recess (notch) that is recessed in the in-plane direction, or has a perforated part that is hollowed out into a shape such as a circle, an ellipse, a polygon, or a combination thereof in a plan view. It means that you can do it.

The size of the laminated body 100 is not particularly limited. When the laminate 100 is single-wafer-shaped and substantially rectangular, the length of the long side is preferably 6 cm or more and 35 cm or less, more preferably 10 cm or more and 30 cm or less, and the length of the short side. Is preferably 5 cm or more and 30 cm or less, and more preferably 6 cm or more and 25 cm or less.

(Polarizing film)
The polarizing film 11 is an absorption type polarizing element having a property of absorbing linearly polarized light having a vibration plane parallel to its absorption axis and transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis (parallel to the transmission axis). Can be. As the polarizing film 11, a polarizer in which a dichroic dye is adsorbed and oriented on a uniaxially stretched polyvinyl alcohol-based resin film can be preferably used. The polarizing film 11 is, for example, a step of uniaxially stretching a polyvinyl alcohol-based resin film; a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol-based resin film with a dichroic dye; polyvinyl having the dichroic dye adsorbed. It can be produced by a method including a step of treating the alcohol-based resin film with a cross-linking solution such as an aqueous boric acid solution; and a step of washing with water after the treatment with the cross-linking solution.

As the polyvinyl alcohol-based resin, a saponified polyvinyl acetate-based resin can be used. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and a copolymer of vinyl acetate and another monomer copolymerizable with the vinyl acetate. 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.

As used herein, the term "(meth) acrylic" means at least one selected from acrylic and methacryl. The same applies to "(meth) acryloyl", "(meth) acrylate" and the like.

The saponification degree of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, 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 be used. The average degree of polymerization of the polyvinyl alcohol-based resin is usually 1000 to 10000, preferably 1500 to 5000. The average degree of polymerization of the polyvinyl alcohol-based resin can be determined in accordance with JIS K 6726.

A film formed of such a polyvinyl alcohol-based resin is used as a raw film for a polarizer. The method for forming a film of the polyvinyl alcohol-based resin is not particularly limited, and a known method is adopted. The thickness of the polyvinyl alcohol-based raw film is not particularly limited, but in order to reduce the thickness of the polarizer to 15 μm or less, it is preferable to use one having a thickness of 5 μm or more and 35 μm or less. More preferably, it is 20 μm or less.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before dyeing the 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 or during the cross-linking treatment. Moreover, uniaxial stretching may be performed in these a plurality of steps.

In uniaxial stretching, rolls having different peripheral speeds may be uniaxially stretched, or thermal rolls may be used to uniaxially stretch the rolls. The uniaxial stretching may be a dry stretching in which the film is stretched in the atmosphere, or a wet stretching in which the polyvinyl alcohol-based resin film is swollen with a solvent or water. The draw ratio is usually 3 to 8 times.

As a method of dyeing a polyvinyl alcohol-based resin film with a dichroic dye, for example, a method of immersing the film in an aqueous solution containing a dichroic dye is adopted. As the dichroic dye, iodine or a dichroic organic dye is used. The polyvinyl alcohol-based resin film is preferably immersed in water before the dyeing treatment.

As the cross-linking treatment after dyeing with a dichroic dye, a method of immersing the dyed polyvinyl alcohol-based resin film in a boric acid-containing aqueous solution is usually adopted. When iodine is used as the dichroic pigment, the boric acid-containing aqueous solution preferably contains potassium iodide.

The thickness of the polarizing film 11 is usually 30 μm or less, preferably 28 μm or less, more preferably 20 μm or less, still more preferably 15 μm or less, and particularly preferably 10 μm or less. The thickness of the polarizing film 11 is usually 2 μm or more, preferably 3 μm or more.

As the polarizing film 11, for example, as described in Japanese Patent Application Laid-Open No. 2016-170368, a film in which a dichroic dye is oriented in a cured film in which a liquid crystal compound is polymerized may be used. As the dichroic dye, a dye having absorption within a wavelength range of 380 nm or more and 800 nm or less can be used, and it is preferable to use an organic dye. Examples of the dichroic dye include an azo compound. The liquid crystal compound is a liquid crystal compound that can be polymerized while being oriented, and can have a polymerizable group in the molecule. Further, as described in WO2011 / 024891, a polarizer may be formed from a dichroic dye having a liquid crystallinity.

(First cured product layer)
The first cured product layer 12 is arranged between the polarizing film 11 and the first retardation layer 13 in order to bond the polarizing film 11 and the first retardation layer 13. The first cured product layer 12 contains a cured product of the first active energy ray-curable composition. When the first cured product layer 12 contains the cured product of the first active energy ray-curable composition, good durability and adhesion tend to be easily obtained. In the present invention, the durability and adhesion are evaluated according to the method described in the column of Examples described later.

The thickness of the first cured product layer 12 may be, for example, 10 μm or less, preferably 8 μm or less, more preferably 7 m or less, still more preferably 6 μm or less, and particularly preferably 4 μm or less. The thickness of the first cured product layer 12 may be, for example, 0.5 μm or more, preferably 1 μm or more, and more preferably 2 μm or more.

(First active energy ray-curable composition)
The first active energy ray-curable composition is a cationically polymerizable composition that is cured by irradiating it with active energy rays. The first active energy ray-curable composition contains 100 parts by mass of the cationically polymerizable compound (A) and the photocationic polymerization initiator (B) by 1 part by mass or more and 10 parts by mass with respect to 100 parts by mass of the cationically polymerizable compound (A). Contains less than a part. The first active energy ray-curable composition further comprises 0.1 parts by mass of a photosensitizer (C) exhibiting maximum absorption in light having a wavelength longer than 400 nm with respect to 100 parts by mass of the cationically polymerizable compound (A). It is preferable to contain more than 3.0 parts by mass.

(Cation-polymerizable compound (A))
The cationically polymerizable compound (A) is a component that can be cured by causing cationic polymerization by irradiation with active energy rays. Adhesive strength is developed by polymerization curing of the cationically polymerizable compound (A). The cationically polymerizable compound (A) contains 45% by mass or more of the oxetane compound (A1) based on the total mass of the cationically polymerizable compound (A). When the oxetane compound (A1) is contained in the first active energy ray-curable composition in an amount of 45% by mass or more, the viscosity of the active energy ray-curable composition is lowered, so that coating with a thin film can be easily performed, and The elastic modulus of the cured product is improved, and it tends to be easy to obtain good durability.

(Oxetane compound (A1))
In the present specification, the oxetane compound (A1) is a compound having an oxetanyl group, and may be an aliphatic compound, an alicyclic compound or an aromatic compound. The oxetane compound (A1) referred to in the present specification is a compound having no epoxy group.
The oxetane compound (A1) may be a monofunctional oxetane compound having only one oxetane group, or a polyfunctional oxetane compound having two or more oxetane group groups. The oxetane compound (A1) is preferably a polyfunctional oxetane compound, and is preferably a bifunctional oxetane compound having two oxetaneyl groups.

Specific examples of the oxetane compound (A1) include 3,7-bis (3-oxetanyl) -5-oxa-nonane and 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, 1, 2-Bis [(3-ethyl-3-oxetanylmethoxy) methyl] ethane, 1,3-bis [(3-ethyl-3-oxetanylmethoxy) methyl] propane, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ) Ether, triethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, tetraethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether ,, 4-bis (3-ethyl-3-oxetanylmethoxy) butane , 1,6-bis (3-ethyl-3-oxetanylmethoxy) hexane, 3-ethyl-3- (phenoxy) methyloxetane, 3-ethyl-3- (cyclohexyloxymethyl) oxetane, 3-ethyl-3-( 2-Ethylhexyloxymethyl) oxetane, 3-ethyl-3-hydroxymethyloxetane, 3-ethyl-3- (chloromethyl) oxetane, 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl} Includes oxetane, xylylene bis oxetane, etc. As the oxetane compound (A1), one kind of oxetane compound may be used alone, or a plurality of different kinds may be used in combination. Of these, 3-ethyl-3-hydroxymethyloxetane, xylylenebis oxetane, 3-ethyl-3- (phenoxymethyl) oxetane, 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl } At least one selected from the group consisting of oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, and 3-ethyl-3- (cyclohexyloxymethyl) oxetane.

Commercially available products can be used as the oxetane compound (A1). For example, the "Aron Oxetane (registered trademark)" series sold by Toa Synthetic Co., Ltd. and Ube Industries, Ltd., respectively, are sold under their trade names. "ETERNACOLL (registered trademark)" series and the like.

The content of the oxetane compound (A1) in the cationically polymerizable compound (A) is 45% by mass or more, preferably 50% by mass or more, more preferably 50% by mass or more, based on the total mass of the cationically polymerizable compound (A). It is 55% by mass or more, more preferably 60% by mass or more. The content of the oxetane compound (A1) in the cationically polymerizable compound (A) may be, for example, 90% by mass or less, preferably 80% by mass or less, and more preferably 75% by mass or less. When the content of the oxetane compound (A1) is 90% by mass or less, the adhesion tends to be less likely to decrease.
When the oxetane compound (A1) contains a polyfunctional oxetane compound and a monofunctional oxetane compound, the polyfunctional oxetane compound may be contained in an amount of 50% by mass or more based on the total mass of the oxetane compound (A1). It is more preferable to contain 60% by mass or more, and even more preferably 70% by mass or more.

(Other cationically polymerizable compounds)
The cationically polymerizable compound (A) can further contain at least one selected from the group consisting of an alicyclic epoxy compound (A2), an aliphatic epoxy compound (A3), and an aromatic epoxy compound (A4).

When the cationically polymerizable compound (A) contains the alicyclic epoxy compound (A2), the content of the alicyclic epoxy compound (A2) is, for example, 10 parts by mass with respect to 100 parts by mass of the cationically polymerizable compound (A). It may be 50 parts by mass or less, preferably 10 parts by mass or more and 40 parts by mass or less, more preferably 10 parts by mass or more and 35 parts by mass or less, and further preferably 10 parts by mass or more and 30 parts by mass or less. When the content of the alicyclic epoxy compound (A2) is 10 parts by mass or more, the curing rate of the cationically polymerizable compound tends to be less likely to decrease. Further, when the content of the alicyclic epoxy compound (A2) is 50 parts by mass or less, the increase in the viscosity of the cationically polymerizable compound is suppressed, and the thin film coating tends to be facilitated.
When the cationically polymerizable compound (A) contains the aliphatic epoxy compound (A3), the content of the aliphatic epoxy compound (A3) is, for example, 1 part by mass or more and 50 parts by mass with respect to 100 parts by mass of the cationically polymerizable compound (A). It may be 5 parts by mass or less, preferably 2.5 parts by mass or more and 40 parts by mass or less, and more preferably 5 parts by mass or more and 30 parts by mass or less from the viewpoint of adhesion.
When the cationically polymerizable compound (A) contains the aromatic epoxy compound (A4), the content of the aromatic epoxy compound (A4) is, for example, 10 parts by mass or more and 50 parts by mass with respect to 100 parts by mass of the cationically polymerizable compound (A). It may be 10 parts by mass or less, preferably 15 parts by mass or more and 40 parts by mass or less, and more preferably 20 parts by mass or more and 30 parts by mass or less. When the content of the aromatic epoxy compound (A4) is 50 parts by mass or less, the adhesion tends to be less likely to decrease.
The curing rate of the cationically polymerizable compound (A) is improved by using the oxetane compound (A1) and the alicyclic epoxy compound (A2) in combination. The ratio is oxetane compound (A1): alicyclic epoxy compound (A2) = 4: 1 to 1: 1, more preferably 3: 1 to 1: 1, and more preferably 2: 1 to 1: 1. .. Within the above range, curing proceeds efficiently, and the obtained cured product can have a dense crosslinked structure.

The first active energy ray-curable composition preferably does not contain a solvent. Hereinafter, each component will be described in detail.

(Alicyclic epoxy compound (A2))
The alicyclic epoxy compound (A2) is a compound having one or more alicyclic epoxy groups.
The alicyclic epoxy compound (A2) may further have an epoxy group other than the alicyclic epoxy group as long as it is a compound having one or more alicyclic epoxy groups. In the present specification, the alicyclic epoxy group means an epoxy group bonded to the alicyclic ring, and means a bridging oxygen atom −O− in the structure represented by the following formula (a).

In the above formula (a), m is an integer of 2 to 5. _{The compound in which the group in the form of removing one or more hydrogen atoms in (CH 2} ) _m in the above formula (a) is bonded to another chemical structure can be an alicyclic epoxy compound (A2). .. One or more hydrogen atoms in (CH ₂ ) _m may be appropriately substituted with a linear alkyl group such as a methyl group or an ethyl group. The curing rate of the first active energy ray-curable composition can be adjusted by the alicyclic epoxy compound (A2).

Specific examples of the alicyclic epoxy compound (A2) include 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 1,2-epoxy-4-vinylcyclohexane, and 1,2-epoxy-1-methyl-. 4- (1-Methylepoxyethyl) cyclohexane, 3,4-epoxycyclohexylmethyl methacrylate, 4- (1,2-epoxyethyl) -1,2- of 2,2-bis (hydroxymethyl) -1-butanol Epoxycyclohexane adduct, ethylene bis (3,4-epoxycyclohexanecarboxylate), oxydiethylene bis (3,4-epoxycyclohexanecarboxylate), 1,4-cyclohexanedimethylbis (3,4-epoxycyclohexanecarboxylate), And 3- (3,4-epoxycyclohexylmethoxycarbonyl) propyl 3,4-epoxycyclohexanecarboxylate and the like.

Among the alicyclic epoxy compounds (A2), 3,4-epoxycyclohexylmethyl and 3,4-epoxycyclohexanecarboxylate are preferably used because they have appropriate curability and can be obtained at a relatively low price. As the alicyclic epoxy compound (A2), one kind of alicyclic epoxy compound may be used alone, or a plurality of different kinds may be used in combination.

Commercially available products can be used as the alicyclic epoxy compound (A2). For example, the "Ceroxide (registered trademark)" series, EHPE3150, and "Cyclomer (Cyclomer)" sold by Daicel Co., Ltd. under their respective trade names. "Registered trademark)", "Cyracure UVR" series sold by Dow Chemical Co., Ltd., etc. can be mentioned.

In the present invention, the aliphatic epoxy compound (A3) is a monofunctional aliphatic epoxy (A3-1) which is a compound having one epoxy group, and a polyfunctional aliphatic epoxy (A3-) having two or more epoxy groups. 2) is included. Polyfunctional aliphatic epoxies are preferable from the viewpoint of maintaining the cohesive force of the cured product and improving the adhesion.

The monofunctional aliphatic epoxy (A3-1) can adjust the viscosity of the first active energy ray-curable composition.
Examples of the monofunctional aliphatic epoxy (A3-1) include glycidyl ethers of aliphatic alcohols and glycidyl esters of alkylcarboxylic acids, and specific examples thereof include allyl glycidyl ether, butyl glycidyl ether, and sec-butylphenyl glycidyl. It contains ether, 2-ethylhexyl glycidyl ether, alkyl glycidyl ether mixed with 12 and 13 carbon atoms, glycidyl ether of alcohol, monoglycidyl ether of aliphatic higher alcohol, glycidyl ester of higher fatty acid and the like. As the monofunctional aliphatic epoxy (A3-1), one type of monofunctional epoxy compound may be used alone, or a plurality of different types may be used in combination.

The polyfunctional aliphatic epoxy (A3-2) is a compound having two or more epoxy groups and no aromatic ring. However, the polyfunctional aliphatic epoxy (A3-2) referred to in the present specification excludes compounds having an alicyclic epoxy group contained in the alicyclic epoxy compound (A2). The adhesiveness of the adhesive cured layer can be adjusted by using the polyfunctional aliphatic epoxy (A3-2).

As the polyfunctional aliphatic epoxy (A3-2), an aliphatic diepoxy compound represented by the following formula (b) is more preferable. By containing the aliphatic diepoxy compound represented by the following formula (b) as the polyfunctional aliphatic epoxy compound (A3), an active energy ray-curable adhesive having a low viscosity and easy to apply can be obtained.

Wherein (b), Z is an alkylene group having 1 to 9 carbon atoms, the number 3 or 4 of the alkylidene group having a carbon, a divalent alicyclic hydrocarbon group, or the formula ^{_{-C m H 2m -Z 1 -C n}} H It is a divalent group represented by _{2n −.} Further, the formula ^{_{-C m H 2m -Z 1 -C n}} H 2n - ^in, -Z 1 - is, -O -, - CO-O -, - O-CO -, - SO 2 -, - SO- Alternatively, it is CO-, and m and n each independently represent an integer of 1 or more, and the sum of m and n is 9 or less.

The divalent alicyclic hydrocarbon group may be, for example, a divalent alicyclic hydrocarbon group having 4 to 8 carbon atoms, and for example, a divalent group represented by the following formula (b-1) may be used. Can be mentioned.

Specific examples of the compound represented by the formula (b) include diglycidyl ether of alkanediol, diglycidyl ether of oligoalkylene glycol up to about 4 repetitions, diglycidyl ether of alicyclic diol and the like.

Examples of the diol (glycol) capable of forming the compound represented by the formula (b) include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, and 2-butyl-. 2-Ethyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl -1,5-pentanediol, 2-methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5- Alcandiols such as heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol and 1,9-nonanediol; oligoalkylene glycols such as diethylene glycol, triethylene glycol, tetraethylene glycol and dipropylene glycol Examples thereof include alicyclic diols such as cyclohexanediol and cyclohexanedimethanol.

From the viewpoint of obtaining a first active energy ray-curable composition having low viscosity and easy to apply, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether Is preferable. As the aliphatic epoxy compound (A3), one kind of aliphatic epoxy compound may be used alone, or a plurality of different kinds may be used in combination.

Commercially available products can be used as the aliphatic epoxy compound (A3), for example, "EP-4088S", "ED-523T" (all manufactured by ADEKA Corporation), "EX-111L", "EX-212L". (The above are all manufactured by Nagase ChemteX Corporation) and the like.

Aromatic epoxy compound (A4)
The aromatic epoxy compound (A4) includes a monofunctional aromatic epoxy (A4-1) which is a compound having one epoxy group, and a polyfunctional aromatic epoxy (A4-2) having two or more epoxy groups. However, the aromatic epoxy compound (A4) referred to in the present specification excludes compounds having an alicyclic epoxy group in the molecule contained in the alicyclic epoxy compound (A2).

Examples of the monofunctional aromatic epoxy (A4-1) include monohydric phenols such as phenol, cresol and butylphenol, bisphenol derivatives such as bisphenol A and bisphenol F, or monoglycidyl esterified products of their alkylene oxide adducts; epoxy novolac resins. A monoglycidyl esterified product of an aromatic compound having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, and catechol; an aromatic compound having two or more alcoholic hydroxyl groups such as benzenedimethanol, benzenediethanol, and benzenedibutanol. Monoglycidyl esterified product; Monoglycidyl ester of a polybasic acid aromatic compound having two or more carboxyl groups such as phthalic acid, terephthalic acid, and trimellitic acid; And so on.

Commercially available products can be used as the monofunctional aromatic epoxy (A4-1), for example, "EX-142", "EX-146", EX-147 "," EX-121 "(all of which are Nagasechem). (Manufactured by Tex Co., Ltd.) and the like.

Specific examples of the polyfunctional aromatic epoxy (A4-2) are naphthalene or a polyglycidyl ether compound of a naphthalene derivative (also referred to as a “naphthalene type epoxy compound”); a polyglycidyl ether of a bisphenol derivative such as bisphenol A or bisphenol F. Derivatives (also referred to as "bisphenol A type epoxy compounds" and "bisphenol F type epoxy compounds"); epoxy novolac resins; polyglycidyl ether compounds of aromatic compounds having two or more phenolic hydroxyl groups such as resorcinol, hydroquinone, and catechol. A polyglycidyl ether compound of an aromatic compound having two or more alcoholic hydroxyl groups such as benzenedimethanol, benzenediethanol, and benzenedibutanol; many having two or more carboxyl groups such as phthalic acid, terephthalic acid, and trimellitic acid. Polyglycidyl ester of basic acid aromatic compound; glycidyl ester of benzoic acid, toluic acid, polyglycidyl ester of naphthoic acid, etc .; styrene oxides such as styrene oxide, alkylated styrene oxide, epoxidized vinylnaphthalene, or diepoxy of divinylbenzene Examples include compounds. As the polyfunctional aromatic epoxy compound (A5), one kind of compound may be used alone, or a plurality of different kinds may be used in combination.

Commercially available products can be used as the polyfunctional aromatic epoxy (A4-2), for example, "Denacol EX-201", "Denacol EX-711" and "Denacol EX-721" (all of which are Nagase ChemteX). (Manufactured by Osaka Gas Chemical Corporation); "Ogsol EG-280" and "Ogsol CG-400" (both manufactured by Osaka Gas Chemical Corporation); "EXA-80CRP" and "HP4032D" (both manufactured by DIC Co., Ltd.) ); "JER828" and "jER828EL" (all manufactured by Mitsubishi Chemical Corporation); "Adeka Resin EP-4100", "Adeka Resin EP-4100G", "Adeka Resin EP-4100E", "Adeka Resin EP-4100L" , "Adeka Resin EP-4100TX", "Adeka Resin EP-4000", "Adeka Resin EP-4005", "Adeka Resin EP-4901", "Adeka Resin EP-491E" (all manufactured by ADEKA Corporation), etc. Be done.

The above-mentioned curable component [oxetane compound (A1), alicyclic epoxy compound (A2), aliphatic epoxy compound (A3), aromatic epoxy compound (A4)] does not contain the first active energy ray-curable composition. In order to use it as a solvent, it is preferable to use one that has not been diluted with an organic solvent or the like.

The above-mentioned curable component is usually liquid at room temperature, has appropriate fluidity even in the absence of a solvent, and is selected to give appropriate adhesive strength, and a suitable photocationic polymerization initiator is blended. In the first active energy ray-curable composition, the drying equipment for evaporating the solvent in the step of adhering the linear polarizing plate and the retardation layer laminate can be omitted in the production equipment of the optical laminate. In addition, the curing rate can be accelerated and the production rate can be improved by irradiating an appropriate active energy dose.

(Other curable ingredients)
The cationically polymerizable compound (A) contained in the first active energy ray-curable composition is not limited to the above-mentioned curable component, and is a cationically polymerizable cure other than the above-mentioned cationically polymerizable curable component. It may contain a sex component and a radically polymerizable curable component. Examples of the radically polymerizable curable component include acrylic compounds.

However, since radical polymerization tends to have a large curing shrinkage, it is preferable that the first active energy ray-curable composition contains only a cationically polymerizable curable component as the cationically polymerizable compound (A).

(Photocationic polymerization initiator (B))
By containing the photocationic polymerization initiator (B), the first active energy ray-curable composition cures the cationically polymerizable compound (A) by cationic polymerization by irradiation with active energy rays to form an adhesive layer. can do.

By containing 1 part by mass or more of the photocationic polymerization initiator (B), the curable component can be sufficiently cured, and an adhesive cured layer having sufficient adhesive strength and hardness can be obtained. On the other hand, if the amount is large, the amount of ionic substances in the cured product increases, which increases the hygroscopicity of the cured product and may reduce the durability performance of the laminate. Therefore, the photocationic polymerization initiator (B) ) Is 10 parts by mass or less with respect to 100 parts by mass of the total amount of the cationically polymerizable compound (A). The content of the photocationic polymerization initiator (B) in the first active energy ray-curable composition is preferably 1.5 parts by mass or more and 8 parts by mass with respect to 100 parts by mass of the total amount of the cationically polymerizable compound (A). Parts or less, more preferably 2 parts by mass or more and 6 parts by mass or less.

The photocationic polymerization initiator (B) generates a cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and causes a polymerization reaction of the cationically polymerizable compound (A). It is something to start. Since the photocationic polymerization initiator (B) acts catalytically with light, it is excellent in storage stability and workability even when mixed with the cationically polymerizable compound (A). As a compound that can be used as a photocationic polymerization initiator (B) and produces a cationic species or Lewis acid by irradiation with active energy rays, for example, an aromatic diazonium salt; an onium salt such as an aromatic iodonium salt or an aromatic sulfonium salt. ; Iron-allene complex and the like can be mentioned. The photocationic polymerization initiator (B) is preferably at least one ionic compound selected from the group consisting of aromatic sulfonium salts and aromatic iodonium salts.

Examples of the aromatic diazonium salt include benzenediazonium hexafluoroantimonate, benzenediazonium hexafluorophosphate, and benzenediazonium hexafluoroborate.

Examples of the aromatic iodonium salt include diphenyliodonium tetrakis (pentafluorophenyl) borate, diphenyliodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, and di (4-nonylphenyl) iodonium hexafluorophosphate.

Examples of the aromatic sulfonium salt include triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, and 4,4'-bis [diphenylsulfonio] diphenylsulfide bishexa. Fluorophosphate, 4,4'-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenylsulfide bishexafluoroantimonate, 4,4'-bis [di (β-hydroxyethoxy) phenylsulfonio] diphenylsulfide bis Hexafluorophosphate, 7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone Hexafluoroantimonate, 7- [di (p-toluyl) sulfonio] -2-isopropylthioxanthone tetrakis (pentafluorophenyl) borate, 4 -Phenylcarbonyl-4'-diphenylsulfonio-diphenylsulfide hexafluorophosphate, 4- (p-tert-butylphenylcarbonyl) -4'-diphenylsulfonio-diphenylsulfide hexafluoroantimonate, 4- (p-tert- Butylphenylcarbonyl) -4'-di (p-toluyl) sulfonio-diphenylsulfide tetrakis (pentafluorophenyl) borate.

Examples of the iron-arene complex include xylene-cyclopentadienyl iron (II) hexafluoroantimonate, cumene-cyclopentadienyl iron (II) hexafluorophosphate, and xylene-cyclopentadienyl iron (II) tris ( Trifluoromethylsulfonyl) metanide.

As the photocationic polymerization initiator (B), only one type may be used alone, or two or more types may be used in combination. Among the above, the aromatic sulfonium salt is particularly preferable because it has an ultraviolet absorbing property even in a wavelength region near 300 nm, and thus an adhesive cured layer having excellent curability and good mechanical strength and adhesive strength can be obtained. Used.

When a radically polymerizable curable component is contained as the curable component, it is preferable to include a radical polymerization initiator as the polymerization initiator in addition to the photocationic polymerization initiator (B).

(Photosensitizer (C))
By incorporating a photosensitizer (C) (hereinafter, also referred to as a photosensitizer (C) for short) that exhibits maximum absorption in light having a wavelength longer than 400 nm in the first active energy ray-curable composition. The curability of the adhesive can be improved as compared with the case where the adhesive is not contained. Further, in the adhesion between the linear polarizing plate and the retardation layer laminate described later, even when the ultraviolet transmittance of the retardation layer or the adhesive layer between the retardation layers is low, it is activated by irradiating ultraviolet rays from the retardation layer side. It is possible to cure the energy ray-curable adhesive composition. Further, in general, the linear polarizing plate arranged on the visual viewing side often contains an ultraviolet absorber, and conventionally, when ultraviolet rays are irradiated from the linear polarizing plate side, the active energy ray-curable adhesive composition is sufficiently cured. I couldn't. However, by using a specific amount of the photosensitizer (C) as in the present invention, it is possible to irradiate the active energy ray from the linear polarizing plate side to cure the active energy ray-curable adhesive composition. ..

（式中、Ｒ^１及びＲ^２は互いに独立に炭素数１〜６のアルキル基又は炭素数２〜１２のアルコキシアルキル基を表し、Ｒ^３は水素原子又は炭素数１〜６のアルキル基を表す）
で示されるアントラセン系化合物を含む。上記の光カチオン重合開始剤（Ｂ）は、３００ｎｍ付近又はそれより短い波長域に極大吸収を示し、その付近の波長の光に感応してカチオン種又はルイス酸を発生し、カチオン重合性の硬化性成分のカチオン重合を開始させるが、一般式（Ｉ）で示されるアントラセン系化合物は、４００ｎｍより長い波長域に極大吸収を示すものであるため、それよりも長い波長の光にも感応することができるようになる。 The photosensitizer (C) has the following general formula (I):

(In the formula, R ¹ and R ² represent an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 12 carbon atoms independently of each other, and R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. )
Includes anthracene compounds represented by. The photocationic polymerization initiator (B) exhibits maximum absorption in a wavelength region near 300 nm or shorter, generates cation species or Lewis acid in response to light having a wavelength in the vicinity, and is cationically polymerizable. Although the cationic polymerization of the sex component is started, the anthracene-based compound represented by the general formula (I) exhibits maximum absorption in a wavelength region longer than 400 nm, and therefore is sensitive to light having a wavelength longer than that. Will be able to.

Specific examples of anthracene compounds include, for example.
9,10-dimethoxyanthracene,
9,10-diethoxyanthracene,
9,10-Dipropoxyanthracene,
9,10-Diisopropoxyanthracene,
9,10-Dibutoxyanthracene,
9,10-Dipentyloxyanthracene,
9,10-dihexyloxyanthracene,
9,10-bis (2-methoxyethoxy) anthracene,
9,10-bis (2-ethoxyethoxy) anthracene,
9,10-Bis (2-butoxyethoxy) anthracene,
9,10-Bis (3-butoxypropoxy) anthracene,
2-Methyl or 2-ethyl-9,10-dimethoxyanthracene,
2-Methyl or 2-Ethyl-9,10-diethoxyanthracene,
2-Methyl or 2-Ethyl-9,10-dipropoxyanthracene,
2-Methyl or 2-ethyl-9,10-diisopropoxyanthracene,
2-Methyl or 2-Ethyl-9,10-dibutoxyanthracene,
2-Methyl or 2-Ethyl-9,10-dipentyloxyanthracene,
2-Methyl or 2-ethyl-9,10-dihexyloxyanthracene can be mentioned.

The content of the photosensitizer (C) in the first active energy ray-curable composition is preferably 0.1 part by mass or more and 5.0 parts by mass with respect to 100 parts by mass of the total amount of the cationically polymerizable compound (A). It is 5 parts by mass or less, more preferably 0.5 parts by mass or more and 3.0 parts by mass or less.
(Photosensitizer (D))
The first active energy ray-curable composition may contain a photosensitizer (D). The photosensitizer (D) is preferably a naphthalene-based photosensitizer.

Specific examples of naphthalene-based photosensitizers include, for example.
4-Methoxy-1-naphthol,
4-ethoxy-1-naphthol,
4-propoxy-1-naphthol,
4-Butoxy-1-naphthol, 4-hexyloxy-1-naphthol,
1,4-dimethoxynaphthalene,
1-ethoxy-4-methoxynaphthalene,
1,4-Diethoxynaphthalene,
1,4-Dipropoxinaphthalene,
Examples thereof include 1,4-dibutoxynaphthalene.

By including the naphthalene-based photosensitizer in the first active energy ray-curable composition, the curing rate of the adhesive can be improved as compared with the case where it is not contained. Such an effect can be exhibited by setting the content of the naphthalene-based photosensitizer to 0.1 parts by mass or more with respect to 100 parts by mass of the total amount of the cationically polymerizable compound (A). On the other hand, if the content of the naphthalene-based photosensitizer increases, problems such as precipitation during low-temperature storage occur. Therefore, the content thereof is based on 100 parts by mass of the total amount of the cationically polymerizable compound (A). It is preferably 5 parts by mass or less. The content of the naphthalene-based photosensitizer is preferably 3 parts by mass or less with respect to 100 parts by mass of the total amount of the cationically polymerizable compound (A).

(Additive component (E))
The first active energy ray-curable composition may contain an additive component (E) as another component which is an optional component as long as the effects of the present invention are not impaired. The additive component (E) includes an ion trap agent, an antioxidant, a light stabilizer, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow conditioner, a plasticizer, a defoaming agent, and a leveling agent. Examples include dyes and organic solvents.

When the additive component (E) is contained, the content thereof is preferably 10 parts by mass or less with respect to 100 parts by mass of the total amount of the cationically polymerizable compound (A).

The above-mentioned photocationic polymerization initiator (B), photosensitizer (C), photosensitizer (D), and additive component (E) were used when preparing the first active energy ray-curable composition. It may be added without a solvent, or it may be diluted with a solvent and then added directly. The above-mentioned numerical range of the content is a numerical range based on the solid content.

(viscosity)
The viscosity of the first active energy ray-curable composition may be any one having a viscosity that can be applied by various methods, but the viscosity at a temperature of 25 ° C. may be, for example, 200 mPa · s or less, which is preferable. Is 10 mPa · s or more and 180 mPa · s or less. If the viscosity is too small, it tends to be difficult to form a layer with a desired thickness. On the other hand, if the viscosity is too high, it tends to be difficult to flow, and it tends to be difficult to obtain a uniform and uniform coating film. The viscosity referred to here is a value measured at 10 rpm after adjusting the temperature of the adhesive to 25 ° C. using an E-type viscometer.

(Curing method)
The first active energy ray-curable composition can be used in an electron beam-curable type or an ultraviolet-curable type. As used herein, an active energy ray is defined as an energy ray capable of decomposing a compound that generates an active species to generate an active species. Examples of such active energy rays include visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays and electron beams.

In the electron beam curing type, any appropriate conditions can be adopted as the electron beam irradiation conditions as long as the first active energy ray curable composition can be cured. For example, in electron beam irradiation, the acceleration voltage is preferably 5 kV or more and 300 kV or less, and more preferably 10 kV or more and 250 kV or less. If the acceleration voltage is less than 5 kV, the electron beam may not reach the adhesive and curing may be insufficient. If the acceleration voltage exceeds 300 kV, the penetrating force through the sample is too strong and the electron beam bounces off, and a transparent protective film or There is a risk of damaging the polarizer. The irradiation dose is 5 kGy or more and 100 kGy or less, more preferably 10 kGy or more and 75 kGy or less. When the irradiation dose is less than 5 kGy, the adhesive is insufficiently cured, and when it exceeds 100 kGy, the optical layer is damaged, mechanical strength is lowered and yellowing occurs, and desired optical characteristics cannot be obtained.

The electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under the condition that a small amount of oxygen is introduced. By appropriately introducing oxygen, it is possible to prevent damage to other optical layers by intentionally causing oxygen inhibition in the optical layer to which the electron beam first hits, and to efficiently irradiate only the adhesive with the electron beam. Can be done.

In the ultraviolet curable type, the light irradiation intensity of the first active energy ray-curable composition is determined for each composition of the adhesive and is not particularly limited, but is 10 mW / cm ² or more and 1,000 mW / cm ² or less. Is preferable. If the light irradiation intensity of the resin composition is ^{less than 10 mW / cm 2} , the reaction time becomes too long, and if it ^{exceeds 1,000 mW / cm 2} , the heat radiated from the light source and the heat generated during the polymerization of the composition cause. , May cause yellowing of the constituent materials of the adhesive. The irradiation intensity is preferably an intensity in a wavelength region effective for activating the photocationic polymerization initiator (B), the photosensitizer (C), and the sensitizer aid (D), and more preferably the wavelength. It is the intensity in the wavelength region of 400 nm or less, and more preferably the intensity in the wavelength region of 280 nm or more and 320 nm or less. Such once with light intensity or by irradiation a plurality of times, the integrated light quantity is preferably 10 mJ / cm ² or more, more preferably set to be 100 mJ / cm ² or more 1,000 mJ / cm ² or less .. If the integrated light intensity to the adhesive is ^{less than 10 mJ / cm 2} , the active species derived from the polymerization initiator are not sufficiently generated, and the adhesive is not sufficiently cured. On the other hand, if the integrated light intensity ^{exceeds 1,000 mJ / cm 2} , the irradiation time becomes long, which is disadvantageous for improving productivity. At this time, depending on the type of the first retardation layer 13 and the second retardation layer 30 and the combination of adhesive types, in which wavelength region (UVA (320 nm or more and 390 nm or less), UVB (280 nm or more and 320 nm or less), etc.). It depends on whether the integrated light intensity is required.

The light source used for polymerizing and curing the first active energy ray-curable composition by irradiation with the active energy beam in the present invention is not particularly limited, and for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, and an ultra-high-pressure mercury lamp. Examples thereof include xenon lamps, halogen lamps, carbon arc lamps, tungsten lamps, gallium lamps, excima lasers, LED light sources that emit light in a wavelength range of 380 nm or more and 440 nm or less, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps. From the viewpoint of energy stability and simplicity of the apparatus, an ultraviolet light source having an emission distribution having a wavelength of 400 nm or less is preferable.

The first active energy ray-curable composition preferably satisfies the following formula (1) from the viewpoint of durability and adhesion.
_{(J A / J B) ×} 100 ≧ 60 (%) (1)
Wherein, _{J A} is the light transmittance at a wavelength of 380nm is 10% or less than 0%, and light transmittance at a wavelength of 400nm is through the substrate is 30% or more, the first active energy ray-curable It represents the amount of heat (unit: mJ / g) measured by a differential scanning calorimeter when the composition is irradiated with ultraviolet rays having a peak at a wavelength of 365 nm.
J _B represents the amount of heat (unit: mJ / g) measured by a differential scanning calorimeter when the first active energy ray-curable composition is irradiated with ultraviolet rays having a peak at a wavelength of 365 nm without using a substrate. .. ]
Heat J _A and J _B can be measured according to the method of measuring in the Examples section below.

By using the first active energy ray-curable composition satisfying the formula (1), good water resistance and adhesion tend to be easily obtained. Further, it becomes possible to cure the active energy ray-curable composition by irradiating the active energy ray from the retardation layer having low ultraviolet ray transmittance or the polarizing film 11 side, which has been difficult in the past.

The left side of the formula (1) is 70% or more, more preferably 80% or more. The left side of the formula (1) is usually 100% or less, for example, less than 100% and 90% or less.

The storage elastic modulus of the first cured product layer 12 at 80 ° C. may be, for example, 300 MPa or more, preferably 500 MPa or more, more preferably 900 MPa or more, and further preferably 900 MPa or more from the viewpoint of resistance to crack generation during processing. It is 1000 MPa or more. The storage elastic modulus at 80 ° C. can be measured according to the measuring method described in the column of Examples described later.

(First retardation layer)
The first retardation layer 13 is not particularly limited as long as it is a retardation layer including at least one retardation expression layer that gives a predetermined retardation to light, and is, for example, a 1/2 wavelength layer, a 1/4 wavelength layer, and a positive. It may be an optical compensation layer such as a C plate. The retardation layer may be a positive dispersion retardation layer or a reverse wavelength dispersion retardation layer. The first retardation layer 13 may be composed of only the retardation expression layer as long as it contains at least one retardation expression layer, or may include another layer together with the retardation expression layer. There may be. Examples of other layers include a base material layer, an alignment film layer, a protective layer and the like. The other layers do not affect the value of the phase difference.

Examples of the retardation expression layer include a layer containing a polymer of a polymerizable liquid crystal compound (hereinafter, also referred to as a liquid crystal layer) or a stretched film. The first retardation layer 13 preferably includes a liquid crystal layer capable of exhibiting retardation. When the first retardation layer 13 includes a liquid crystal layer, it is preferable that the surface of the first retardation layer 13 opposite to the first cured product layer 12 side is a liquid crystal layer capable of exhibiting retardation. When the retardation expression layer is a liquid crystal layer, it is generally easier to make a thin film than when the retardation expression layer is a stretched film.

The first retardation layer 13 has a light transmittance of 0% or more and 50% or less (preferably 0% or more and 10% or less) at a wavelength of 380 nm, and a light transmittance of 30% or more at a wavelength of 400 nm. can. The light transmittance can be measured according to the measurement method described in the column of Examples described later. The first retardation layer 13 may have a light transmittance of 0% or more and 5% or less at a wavelength of 380 nm and a light transmittance of 10% or more at a wavelength of 400 nm.

When the first retardation layer 13 is composed of only the retardation expression layer, the thickness is preferably 0.5 μm or more and 10 μm or less, and preferably 0.5 μm or more and 5 μm or less.
When the first retardation layer 13 includes a layer other than the retardation expression layer (base material layer, alignment film layer, protective layer, etc.), the total thickness is 0.5 μm or more and 10 μm or less, and 0.5 μm or more. It is more preferably 5 μm or less.

The 1/2 wavelength layer gives a phase difference of π (= λ / 2) to the electric field vibration direction (polarization plane) of the incident light, and has a function of changing the direction of linearly polarized light (polarization direction). .. Further, when circularly polarized light is incident, the direction of rotation of circularly polarized light can be reversed.

The 1/2 wavelength layer is a layer in which Re (λ), which is an in-plane retardation value at a specific wavelength λ nm, satisfies Re (λ) = λ / 2. Re (λ) = λ / 2 may be achieved at any wavelength in the visible light region, but it is particularly preferable that it is achieved at a wavelength of 550 nm. The in-plane retardation value of Re (550) at a wavelength of 550 nm preferably satisfies 210 nm ≦ Re (550) ≦ 300 nm. Further, it is more preferable to satisfy 220 nm ≦ Re (550) ≦ 290 nm.

The 1/4 wavelength layer gives a phase difference of π / 2 (= λ / 4) to the electric field vibration direction (polarization plane) of the incident light, and linearly polarized light of a specific wavelength is changed to circularly polarized light (or circularly polarized light). It has the function of converting polarized light (to linearly polarized light).

The 1/4 wavelength layer is a layer in which Re (λ), which is an in-plane retardation value at a specific wavelength λ nm, satisfies Re (λ) = λ / 4, and is achieved at any wavelength in the visible light region. However, it is preferable that the wavelength is 550 nm. It is preferable that Re (550), which is an in-plane retardation value at a wavelength of 550 nm, satisfies 100 nm ≦ Re (550) ≦ 160 nm. Further, it is more preferable to satisfy 110 nm ≦ Re (550) ≦ 150 nm.

Examples of the optical compensation layer include a positive A plate and a positive C plate. The positive A plate has Nx> Ny when the refractive index in the slow axis direction in the plane is Nx, the refractive index in the phase advance axis direction in the plane is Ny, and the refractive index in the thickness direction is Nz. Satisfy the relationship. The positive A plate preferably satisfies the relationship of Nx> Ny ≧ Nz. The positive A plate can also function as a quarter wavelength layer. The positive C plate satisfies the relationship of Nz> Nx ≧ Ny.

The inverse wavelength dispersibility is an optical characteristic in which the in-plane retardation value at a short wavelength is smaller than the in-plane retardation value at a long wavelength, and the following formula (b):
Re (450) ≤ Re (550) ≤ Re (650) (b)
To meet. Re (λ) represents an in-plane retardation value for light having a wavelength of λ nm.

The optical characteristics of the first retardation layer 13 can be adjusted by the orientation state of the liquid crystal compound constituting the retardation expression layer or the stretching method of the stretched film constituting the retardation expression layer.

(1) Phase difference expression layer formed from a liquid crystal layer A case where the phase difference expression layer is a liquid crystal layer will be described. FIG. 2 is a schematic cross-sectional view schematically showing an example of a retardation layer including a retardation expression layer which is a liquid crystal layer and another layer. As shown in FIG. 2, the retardation layer 30 is formed by laminating a base material layer 31, an alignment layer 32, and a retardation expression layer 33, which is a liquid crystal layer, in this order. The retardation layer is not limited to the retardation layer 30 shown in FIG. 2 as long as it includes the retardation expression layer 33 of the liquid crystal layer, and the base material layer 31 is peeled off from the retardation layer 30 to form an orientation layer. It may be composed of only the retardation layer 33 and the retardation layer 33, or may be composed of only the retardation layer 33 of the liquid crystal layer by peeling the base material layer 31 and the alignment layer 32 from the retardation layer 30. good. From the viewpoint of thinning, the retardation layer preferably has a structure in which the base material layer 31 is peeled off, and more preferably a structure consisting of only the retardation expression layer 33 of the liquid crystal layer. The base material layer 31 has a function as a support layer that supports the alignment layer 32 formed on the base material layer 31 and the retardation expression layer 33 of the liquid crystal layer. The base material layer 31 is preferably a film made of a resin material.

As the resin material, for example, a resin material having excellent transparency, mechanical strength, thermal stability, stretchability and the like is used. Specifically, polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene polymers; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (meth) acrylic acid, poly (meth) methyl acrylate and the like. (Meta) acrylic acid resin; cellulose ester resin such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; vinyl alcohol resin such as polyvinyl alcohol and polyvinyl acetate; polycarbonate resin; polystyrene resin; poly Arilate-based resin; polysulfone-based resin; polyether sulfone-based resin; polyamide-based resin; polyimide-based resin; polyether ketone-based resin; polyphenylene sulfide-based resin; polyphenylene oxide-based resin, and mixtures and copolymers thereof. Can be done. Among these resins, it is preferable to use any one of cyclic polyolefin-based resin, polyester-based resin, cellulose ester-based resin and (meth) acrylic acid-based resin, or a mixture thereof. The above-mentioned "(meth) acrylic acid" means "at least one of acrylic acid and methacrylic acid".

The base material layer 31 may be a single layer obtained by mixing one type or two or more of the above resins, or may have a multilayer structure of two or more layers. When having a multi-layer structure, the resins forming each layer may be the same or different.

Any additive may be added to the resin material forming the resin film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an antioxidant, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent.

The thickness of the base material layer 31 is not particularly limited, but it is preferable not to include the base material layer 31 in order to make the total thickness of the first retardation layer 13 10 μm or less.

In order to improve the adhesion between the base material layer 31 and the alignment layer 32, at least the surface of the base material layer 31 on the side where the alignment layer 32 is formed may be subjected to corona treatment, plasma treatment, flame treatment, or the like. A primer layer or the like may be formed. When the base material layer 31, or the base material layer 31 and the alignment layer 32 are peeled off to form a retardation layer, the peeling can be facilitated by adjusting the adhesion at the peeling interface.

The alignment layer 32 has an orientation regulating force that aligns the liquid crystal compound contained in the phase difference expressing layer 33 of the liquid crystal layer formed on the alignment layer 32 in a desired direction. Examples of the oriented layer 32 include an oriented polymer layer formed of an oriented polymer, a photo-aligned polymer layer formed of a photo-aligned polymer, and a grub-aligned layer having an uneven pattern and a plurality of grubs (grooves) on the layer surface. Can be done. The thickness of the alignment layer 32 is usually 0.01 μm or more and 10 μm or less, and preferably 0.01 μm or more and 5 μm or less.

The oriented polymer layer can be formed by applying a composition in which the oriented polymer is dissolved in a solvent to the base material layer 31 to remove the solvent, and if necessary, rubbing treatment. In this case, the orientation regulating force can be arbitrarily adjusted in the orientation polymer layer formed of the orientation polymer depending on the surface condition of the orientation polymer and the rubbing conditions.

The photo-aligned polymer layer can be formed by applying a composition containing a polymer or monomer having a photoreactive group and a solvent to the base material layer 31 and irradiating it with polarized light. In this case, in the photo-alignment polymer layer, the orientation-regulating force can be arbitrarily adjusted depending on the polarization irradiation conditions of the photo-alignment polymer.

The grub alignment layer is active on a plate-shaped master having grooves on the surface, for example, a method of forming a concavo-convex pattern by exposure, development, etc. through an exposure mask having a pattern-shaped slit on the surface of a photosensitive polyimide film. A method of forming an uncured layer of an energy ray-curable resin and transferring this layer to a base material layer 31 for curing, forming an uncured layer of an active energy ray-curable resin on the base material layer 31 and this It can be formed by a method of forming irregularities by pressing a roll-shaped master having irregularities against the layer and hardening the layers.

The phase difference expression layer 33, which is a liquid crystal layer, is not particularly limited as long as it gives a predetermined phase difference to light, and is, for example, a phase difference expression layer for a 1/2 wavelength layer and a position for a 1/4 wavelength layer. Examples thereof include a phase difference expression layer, a phase difference expression layer for an optical compensation layer such as a positive C plate, and a phase difference expression layer for an inverse wavelength dispersibility 1/4 wavelength layer.

The phase difference expression layer 33, which is a liquid crystal layer, can be formed by using a known liquid crystal compound. The type of the liquid crystal compound is not particularly limited, and a rod-shaped liquid crystal compound, a disk-shaped liquid crystal compound, and a mixture thereof can be used. Further, the liquid crystal compound may be a polymer liquid crystal compound, a polymerizable liquid crystal compound, or a mixture thereof. Examples of the liquid crystal compound include JP-A-11-513019, JP-A-2005-289980, JP-A-2007-108732, JP-A-2010-2404038, JP-A-2010-31223, and JP-A. The liquid crystal compounds described in JP-A-2010-270108, JP-A-2011-6360, JP-A-2011-207765, JP-A-2016-81035, WO2017 / 043438 and JP-A-2011-207765. Can be mentioned.

For example, when a polymerizable liquid crystal compound is used, a composition containing the polymerizable liquid crystal compound is applied onto the alignment layer 32 to form a coating film, and the coating film is cured to cure the retardation layer 33. Can be formed. The thickness of the retardation expression layer 33 is preferably 0.5 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less.
In addition to the liquid crystal compound, the composition containing the polymerizable liquid crystal compound may contain a polymerization initiator, a polymerizable monomer, a surfactant, a solvent, an adhesion improver, a plasticizer, an orienting agent and the like. Examples of the method for applying the composition containing the polymerizable liquid crystal compound include known methods such as a die coating method. Examples of the curing method of the composition containing the polymerizable liquid crystal compound include known methods such as irradiation with active energy rays (for example, ultraviolet rays).

(2) A phase difference layer provided with a stretched film as a retardation expression layer A case where the retardation expression layer is a stretched film will be described. The stretched film is usually obtained by stretching the base material. As a method of stretching the base material, for example, a roll (winding body) in which the base material is wound on a roll is prepared, and the base material is continuously unwound and unwound from the winding body. The base material is transferred to the heating furnace. The set temperature of the heating furnace is in the range of the base material near the glass transition temperature (° C) to [glass transition temperature +100] (° C), preferably near the glass transition temperature (° C) to [glass transition temperature +50] (° C). The range of. In the heating furnace, when the base material is stretched in the traveling direction or in the direction orthogonal to the traveling direction, the transport direction and tension are adjusted and the base material is inclined at an arbitrary angle to perform uniaxial or biaxial thermal stretching treatment. conduct. The stretching ratio is usually 1.1 to 6 times, preferably 1.1 to 3.5 times.

Further, the method of stretching in the oblique direction is not particularly limited as long as the orientation axis can be continuously tilted at a desired angle, and a known stretching method can be adopted. Examples of such a stretching method include the methods described in JP-A-50-83482 and JP-A-2-113920. When imparting retardation to a film by stretching, the thickness after stretching is determined by the thickness before stretching and the stretching ratio.

The base material is usually a transparent base material. The transparent base material means a base material having transparency capable of transmitting light, particularly visible light, and the transparency means a characteristic that the transmittance for light rays having a wavelength of 380 nm or more and 780 nm or less is 80% or more. To say. Specific examples of the transparent base material include a translucent resin base material. Resins constituting the translucent resin base material include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene-based polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid ester; polyacrylic acid ester; triacetylcellulose, Cellulose esters such as diacetyl cellulose and cellulose acetate propionate; polyethylene naphthalate; polycarbonate; polysulfone; polyethersulfone; polyether ketone; polyphenylene sulfide and polyphenylene oxide. From the viewpoint of availability and transparency, polyethylene terephthalate, polymethacrylic acid ester, cellulose ester, cyclic olefin resin or polycarbonate is preferable.

Cellulose esters are those in which some or all of the hydroxyl groups contained in cellulose are esterified and can be easily obtained from the market. Cellulose ester substrates are also readily available on the market. Examples of commercially available cellulose ester base materials include "Fujitac (registered trademark) film" (Fujifilm Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (Konica Minolta Opto Co., Ltd.). ..

Polymethacrylic acid esters and polyacrylic acid esters (hereinafter, polymethacrylic acid esters and polyacrylic acid esters may be collectively referred to as (meth) acrylic resins) are easily available on the market.

Examples of the (meth) acrylic resin include homopolymers of methacrylic acid alkyl esters or acrylic acid alkyl esters, and copolymers of methacrylic acid alkyl esters and acrylic acid alkyl esters. Specific examples of the methacrylic acid alkyl ester include methyl methacrylate, ethyl methacrylate and propyl methacrylate, and specific examples of the acrylic acid alkyl ester include methyl acrylate, ethyl acrylate and propyl acrylate. As the (meth) acrylic resin, a commercially available general-purpose (meth) acrylic resin can be used. As the (meth) acrylic resin, what is called an impact resistant (meth) acrylic resin may be used.

It is also preferable to include rubber particles in the (meth) acrylic resin in order to further improve the mechanical strength. The rubber particles are preferably acrylic particles. Here, the acrylic rubber particles have rubber elasticity obtained by polymerizing an acrylic monomer containing an acrylic acid alkyl ester as a main component, such as butyl acrylate or 2-ethylhexyl acrylate, in the presence of a polyfunctional monomer. It is a particle. The acrylic rubber particles may be formed by forming such particles having rubber elasticity in a single layer, or may be a multilayer structure having at least one rubber elastic layer. Examples of the multi-layered acrylic rubber particles include those having the above-mentioned particles having rubber elasticity as nuclei and covering them with a hard methacrylic acid alkyl ester polymer, and hard methacrylic acid alkyl ester polymers. The core is made of an acrylic polymer having rubber elasticity as described above, and the hard core is covered with a rubber elastic acrylic polymer, and the periphery thereof is a hard alkyl methacrylic acid ester. Examples thereof include those covered with a system polymer. The rubber particles formed by the elastic layer usually have an average diameter in the range of 50 nm or more and 400 nm or less.

The content of rubber particles in the (meth) acrylic resin is usually 5 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the (meth) acrylic resin. Since the (meth) acrylic resin and the acrylic rubber particles are commercially available in a mixed state, the commercially available products can be used. Examples of commercially available (meth) acrylic resins containing acrylic rubber particles include "HT55X" and "Technoloy S001" sold by Sumitomo Chemical Co., Ltd. "Technoloy S001" is sold in the form of a film.

Cyclic olefin resins are readily available on the market. Commercially available cyclic olefin resins include "Topas" (registered trademark) [Ticona (Germany)], "Arton" (registered trademark) [JSR Co., Ltd.], "ZEONOR" (registered trademark) [Japan. Zeon Co., Ltd.], "ZEONEX" (registered trademark) [Zeon Corporation] and "Apel" (registered trademark) [Mitsui Chemicals Co., Ltd.]. Such a cyclic olefin resin can be used as a base material by forming a film by a known means such as a solvent casting method or a melt extrusion method. A commercially available cyclic olefin resin base material can also be used. Commercially available cyclic olefin resin base materials include "Sushina" (registered trademark) [Sekisui Chemical Co., Ltd.], "SCA40" (registered trademark) [Sekisui Chemical Co., Ltd.], and "Zeonor Film" (registered trademark). ) [Optes Co., Ltd.] and "Arton Film" (registered trademark) [JSR Co., Ltd.].

When the cyclic olefin resin is a copolymer of a cyclic olefin and an aromatic compound having a chain olefin or a vinyl group, the content ratio of the structural unit derived from the cyclic olefin is the total structural unit of the copolymer. On the other hand, it is usually in the range of 50 mol% or less, preferably 15 mol% or more and 50 mol% or less. Examples of the chain olefin include ethylene and propylene, and examples of the aromatic compound having a vinyl group include styrene, α-methylstyrene and alkyl-substituted styrene. When the cyclic olefin resin is a ternary copolymer of a cyclic olefin, a chain olefin, and an aromatic compound having a vinyl group, the content ratio of the structural unit derived from the chain olefin is the content of the copolymer. The content ratio of the structural unit derived from the aromatic compound having a vinyl group, which is usually 5 mol% or more and 80 mol% or less with respect to the total structural unit, is usually 5 mol with respect to the total structural unit of the copolymer. % Or more and 80 mol% or less. Such a ternary copolymer has an advantage that the amount of expensive cyclic olefin used can be relatively reduced in the production thereof.

(Other layers)
The laminate 100 may further have other layers in addition to the polarizing film 11, the first cured product layer 12, and the first retardation layer 13. The other layers will be described with reference to FIG. As shown in FIG. 3, in the laminated body 100, the second cured product layer 14 and the second cured product layer 15 are laminated in this order on the side of the first retardation layer 13 opposite to the first cured product layer 12. It may have been done. Further, in the laminated body 100, the thermoplastic resin film 16 may be laminated on the side of the polarizer 11 opposite to the first cured product layer 12 via the adhesive layer 17. Further, the laminated body 100 may have the pressure-sensitive adhesive layer 18 on the side of the second retardation layer 15.

(Second cured product layer)
The second cured product layer 14 is arranged between the first retardation layer 13 and the second retardation layer 15, and adheres the first retardation layer 13 and the second retardation layer 15. The second cured product layer 14 contains a cured product of the second active energy ray-curable composition.

The second active energy ray-curable composition may be a composition that is cured by irradiating it with active energy rays, and may be, for example, a cationically polymerizable adhesive composition or a radically polymerizable adhesive composition. You may. The second active energy ray-curable composition may not contain either a photosensitizer or a photosensitizer. As examples and preferred ranges of the cationically polymerizable adhesive composition, for example, examples and preferred ranges in the description of the first active energy ray-curable composition are applied.

The thickness of the second cured product layer 14 may be, for example, 20 μm or less, preferably 10 μm or less, more preferably 6 μm or less, and further preferably 5 μm or less. The thickness of the second cured product layer 14 may be, for example, 0.5 μm or more, preferably 1 μm or more.

(Second retardation layer)
The second retardation layer 15 is not particularly limited as long as it is a retardation layer including at least one retardation expression layer that gives a predetermined retardation to light. As the example and preferable range of the second retardation layer 15, the example and preferable range of the first retardation layer 13 are applied. Hereinafter, a laminate in which the second retardation layer 15 and the first retardation layer 13 are adhered to each other via the second cured product layer 14 is also referred to as a retardation layer laminate.

The second retardation layer 15 preferably includes a liquid crystal layer capable of exhibiting retardation. When the second retardation layer includes a liquid crystal layer, it is preferable that the surface of the second retardation layer 15 on the side of the second cured product layer 14 is a liquid crystal layer capable of exhibiting retardation. When the laminate includes the first retardation layer and the second retardation layer, at least one of the first retardation layer and the second retardation layer preferably includes a liquid crystal layer exhibiting retardation.

The second retardation layer 15 can have a light transmittance of 0% or more and 90% or less at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm. The second retardation layer 15 may have a light transmittance of 0% or more and 80% or less at a wavelength of 380 nm and a light transmittance of 50% or more at a wavelength of 400 nm.
When the laminate includes the first retardation layer and the second retardation layer, at least one of the first retardation layer and the second retardation layer preferably has a light transmittance of 0% or more and 10% or less at a wavelength of 380 nm. And the light transmittance at a wavelength of 400 nm is 30% or more.

The thickness of the second retardation layer 15 is preferably 0.5 μm or more and 50 μm or less, and more preferably 0.5 μm or more and 5 μm or less.

As a combination of the first retardation layer 13 and the second retardation layer 15, for example,
i) Combination of 1/2 wavelength layer and 1/4 wavelength layer,
ii) Combination of 1/2 wavelength layer and optical compensation layer,
iii) Combination of 1/4 wavelength layer and optical compensation layer,
And so on.

In the case of i), it is preferable that the first retardation layer 13 is a 1/2 wavelength layer and the second retardation layer 15 is a 1/4 wavelength layer.

In the case of ii), it is preferable that the first retardation layer 13 is a 1/2 wavelength layer, the second retardation layer 15 is an optical compensation layer, and the first retardation layer 13 is a 1/2 wavelength layer. , It is more preferable that the second retardation layer 15 is a positive C plate.

In the case of iii), it is preferable that the first retardation layer 13 is a 1/4 wavelength layer, the second retardation layer 15 is an optical compensation layer, and the first retardation layer 13 is a 1/4 wavelength layer. , It is more preferable that the second retardation layer 15 is a positive C plate.

(Thermoplastic resin film)
The thermoplastic resin film 16 can be arranged on the visible side of the laminate. The thermoplastic resin film 16 can have the function of a protective film for protecting the polarizing film 11. A laminate in which the polarizing film 11 and the thermoplastic resin film 16 are laminated via the adhesive layer 17 is also referred to as a linear polarizing plate. Although not shown, the thermoplastic resin film may be arranged on both sides of the polarizer. The thermoplastic resin film is preferably arranged on one side of the polarizer, and is preferably arranged only on the visible side of the laminate from the viewpoint of thinning.

The material of the thermoplastic resin film 16 is not particularly limited, but for example, a cyclic polyolefin resin film, a cellulose acetate resin film made of a resin such as triacetyl cellulose or diacetyl cellulose, polyethylene terephthalate, or polyethylene na. Examples of films known in the art include polyester resin films made of resins such as phthalate and polybutylene terephthalate, polycarbonate resin films, (meth) acrylic resin films, and polypropylene resin films. From the viewpoint of thinning, the thickness of the thermoplastic resin film 16 is usually 300 μm or less, preferably 200 μm or less, more preferably 50 μm or less, and usually 5 μm or more, 10 μm or more. Is preferable. Further, the thermoplastic resin film 16 may or may not have a phase difference.

The thermoplastic resin film 16 contains rubber particles, lubricants, fluorescent whitening agents, dispersants, heat stabilizers, light stabilizers, ultraviolet absorbers, infrared absorbers, antistatic agents, antioxidants, etc., as required. The additive may be contained alone or in combination of two or more.

(Adhesive layer)
The adhesive layer 17 can be arranged to bond the thermoplastic resin film 16 and the polarizing film 11. The adhesive layer 17 preferably contains a cured product of the water-based adhesive composition. As the water-based adhesive composition, for example, a polyvinyl alcohol-based resin or a urethane resin is used as a main component, and a cross-linking agent or a curable compound such as an isocyanate-based compound or an epoxy compound is blended in order to improve adhesion. Can be a thing.

When a polyvinyl alcohol-based resin is used as the main component of the aqueous adhesive composition, in addition to partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, etc. And modified polyvinyl alcohol-based resins such as amino group-modified polyvinyl alcohol may be used. The water-based adhesive composition preferably contains an acetoacetyl group-modified polyvinyl alcohol. Such an aqueous solution of a polyvinyl alcohol-based resin is used as a water-based adhesive, and the concentration of the polyvinyl alcohol-based resin in the water-based adhesive is usually 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of water. It is preferably 1 part by mass or more and 5 parts by mass or less.

A curable compound such as a polyhydric aldehyde, a water-soluble epoxy resin, a melamine compound, a zirconia compound, and a zinc compound is added to an aqueous adhesive composition composed of an aqueous solution of a polyvinyl alcohol resin in order to improve adhesion. Can be blended. To give an example of a water-soluble epoxy resin, a water-soluble epoxy resin obtained by reacting a polyamide polyamine obtained by reacting a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid with epichlorohydrin. There is a sex polyamide epoxy resin. As commercially available products of such polyamide epoxy resin, "Sumirace Resin 650" and "Sumiraizu Resin 675" sold by Sumika Chemtex Co., Ltd., "WS-525" sold by Japan PMC Co., Ltd., etc. There is. When the water-soluble epoxy resin is blended, the amount added is usually 1 part by mass or more and 100 parts by mass or less, preferably 1 part by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the polyvinyl alcohol-based resin.

When a urethane resin is used as the main component of the water-based adhesive composition, it is effective to use a polyester ionomer-type urethane resin as the main component of the water-based adhesive composition. The polyester-based ionomer type urethane resin referred to here is a urethane resin having a polyester skeleton, in which a small amount of an ionic component (hydrophilic component) is introduced. Since such an ionomer type urethane resin is directly emulsified in water to form an emulsion without using an emulsifier, it can be used as an aqueous adhesive. When a polyester ionomer type urethane resin is used, it is effective to add a water-soluble epoxy compound as a cross-linking agent. Using a polyester ionomer type urethane resin as an adhesive for a polarizing plate is described in, for example, Japanese Patent Application Laid-Open No. 2005-70140 and Japanese Patent Application Laid-Open No. 2005-208456.

The water-based adhesive composition can contain an ultraviolet absorber, a filler, a flow conditioner, a defoaming agent, a leveling agent, a dye, an organic solvent and the like.

The water-based adhesive composition is usually used in the form of each component dissolved in water. The components contained in the water-based adhesive composition that are insoluble in water may be dispersed in the system. A transparent pressure-sensitive adhesive may be formed by applying the water-based adhesive composition to one side of the polarizer and drying it.

The water-based adhesive composition is applied to one or both sides of a polarizer or a thermoplastic resin film, and then bonded to each other. Then, the water is evaporated by heating and the thermal cross-linking reaction is allowed to proceed to sufficiently bond the two. can do.

The thickness of the adhesive layer 17 may be, for example, 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less. The thickness of the adhesive layer 17 may be, for example, 0.1 μm or more.

(Adhesive layer)
The laminated body 100 may have the pressure-sensitive adhesive layer 18 on the side of the second retardation layer 15. The pressure-sensitive adhesive layer 18 can be composed of a pressure-sensitive adhesive composition containing a resin as a main component, such as (meth) acrylic-based, rubber-based, urethane-based, ester-based, silicone-based, and polyvinyl ether-based. Among them, a pressure-sensitive adhesive composition using a (meth) acrylic resin having excellent transparency, weather resistance, heat resistance and the like as a base polymer is preferable. The pressure-sensitive adhesive composition may be an active energy ray-curable type or a thermosetting type. The thickness of the pressure-sensitive adhesive layer 18 is usually 3 μm or more and 30 μm or less, preferably 3 μm or more and 25 μm or less.

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 containing 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) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl (). Examples thereof include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group and the like, such as meta) acrylate.

The pressure-sensitive adhesive composition 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.

(Manufacturing method of laminated body)
An example of the method for producing the laminate of the present invention will be described with reference to FIG. As shown in FIG. 4A, a linear polarizing plate 10 in which a polarizing film 11 and a thermoplastic resin film 16 are laminated via an adhesive layer 17 is produced. As shown in FIG. 4B, the first retardation layer 13 including the first retardation expression layer 21, the first alignment layer 22, and the first base material layer 23, the second retardation expression layer 26, and the second orientation. A second retardation layer 15 including a layer 25 and a second base material layer 24 is prepared, and as shown in FIG. 4C, the first retardation layer 13 and the second retardation layer 15 are second cured. The layers are laminated via the material layer 14, and the first base material layer 23, the first alignment layer 22, the first retardation expression layer 21, the second cured product layer 14, the second retardation expression layer 26, and the second alignment layer 25 are laminated. , The retardation layer laminated body 50 in which the second base material layer 24 is laminated in this order is produced. As shown in FIG. 4D, the polarizing film 11 side of the linear polarizing plate 10 and the first retardation layer 13 side of the retardation layer laminate 50 are laminated via the first cured product layer 12, and the laminate is formed. Get 70.

As a method of adhering the polarizing film 11 and the thermoplastic resin film 16, a water-based adhesive composition is applied to either or both of the laminating surfaces of the polarizing film 11 and the thermoplastic resin film 16, and the film is further coated. Examples thereof include a method of laminating one of the bonded surfaces and curing the water-based adhesive composition constituting the adhesive layer 17.

As a method of adhering the first retardation layer 13 and the second retardation layer 15, it is active on either or both of the bonding surface of the first retardation layer 13 and the bonding surface of the second retardation layer 15. Examples thereof include a method in which an energy ray-curable composition is applied, the other bonded surface is laminated thereto, and the active energy ray-curable adhesive constituting the second cured product layer 14 is cured. The active energy ray for curing the second cured product layer 14 can be irradiated from either or both sides of the first retardation layer 13 and the second retardation layer 15.

As a method of adhering the linear polarizing plate 10 and the retardation layer laminate 50, the active energy ray-curable property is applied to either or both of the bonding surface of the linear polarizing plate 10 and the retardation layer laminate 50. A method of applying the composition, laminating the other bonded surface on the composition, and curing the active energy ray-curable adhesive constituting the first cured product layer 12 can be mentioned. From the viewpoint of adhesion, the active energy ray-curable adhesive composition is preferably applied only to the bonded surface of the retardation layer laminate 50. The active energy rays for curing the first cured product layer 12 can be irradiated from either one or both sides of the linear polarizing plate 10 and the retardation layer laminate 50.

Corona treatment, plasma treatment, or the like may be performed on either or both of the bonded surfaces, or a primer layer may be formed. For coating the water-based adhesive composition and the active energy ray-curable composition, various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used.

The laminated body of the present invention may be a laminated body as shown in FIG. 4 (D), or is a laminated body in which at least one of the first base material layer 23 and the second base material layer 24 is peeled off. You may. Further, it may be a laminate in which the first base material layer 23 and the first alignment layer 22 are peeled off from the laminate shown in FIG. 4 (D), or a second base layer from the laminate shown in FIG. 4 (D). It may be a laminated body in which the material layer 24 and the second alignment layer 25 are peeled off.

(Use)
The laminate 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. The image display device includes a liquid crystal display device, an organic electroluminescence (EL) display device, an inorganic electroluminescence (EL) display device, a touch panel display device, an electron emission display device (for example, an electric field emission display device (FED), a surface electric field emission display). Device (SED)), electronic paper (display device using electronic ink or electrophoresis element, plasma display device, projection type display device (for example, grating light valve (GLV) display device, display with digital micromirror device (DMD)) Devices) and piezoelectric ceramic displays, etc. Examples of the liquid crystal display device include any of a transmissive liquid crystal display device, a transflective liquid crystal display device, a reflective liquid crystal display device, a direct-view type liquid crystal display device, and a projection type liquid crystal display device. These image display devices may be an image display device for displaying a two-dimensional image or a three-dimensional image display device for displaying a three-dimensional image. In particular, a polarizing plate which is a circular polarizing plate. The composite can be effectively used in an organic electroluminescence (EL) display device which may include an image display panel having a bent portion.

The laminated body can have a function as a circularly polarizing plate and an antireflection film. The laminate can be arranged on the viewing side of the image display layer panel in a direction in which the polarizing film is located on the viewing side. The laminate is suitable as a circularly polarizing plate or an antireflection film used in an in-vehicle image display device.

Hereinafter, the present invention will be described in more detail with reference to Examples. Unless otherwise specified, "%" and "part" in the example are mass% and parts by mass.

(Viscosity measurement)
The active energy ray-curable composition was adjusted to 25 ° C. using an E-type viscometer [“TVE-25” manufactured by Toki Sangyo Co., Ltd.], and then measured at 10 rpm.

(Measurement of heat)
An active energy ray-curable adhesive composition is placed on a differential scanning calorimeter, and the active energy ray-curable adhesive composition is irradiated with ultraviolet rays having a peak at a wavelength of 365 nm, and the calorific value J _B (unit: mJ / g). Was measured. A peak at a wavelength of 365 nm is formed in the active energy ray-curable adhesive composition through a substrate having a light transmittance of 0% or more and 10% or less at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm. the UV radiation having irradiated, heat _{J a} (unit: mJ / g) was measured.

(Measurement of light transmittance)
The λ / 4 retardation layer and the positive C plate were cut to a size of 30 mm × 30 mm, and the transmittance was measured in the wavelength range of 200 to 510 nm. An ultraviolet-visible spectrophotometer "UV-2450" manufactured by Shimadzu Corporation was used for the measurement.

(Measurement of storage elastic modulus at 80 ° C)
The prepared active energy ray-curable composition was applied to one side of a polyethylene terephthalate film [trade name "Toyobo Ester Film E7002", manufactured by Toyobo Co., Ltd.] on a coating machine [Barcoater, manufactured by Daiichi Rika Co., Ltd.]. Was applied so that the film thickness after curing was about 10 μm. Next, the adhesive was cured by irradiating with ultraviolet rays so that the ^{integrated light amount was 1,000 mJ / cm 2} by a "D bulb" manufactured by Fusion UV Systems. This was cut into a size of 5 mm × 30 mm, and the polyethylene terephthalate film was peeled off to obtain a cured film of an adhesive. The cured film thus obtained was gripped with a dynamic viscoelasticity measuring device "DVA-220" manufactured by IT Measurement Control Co., Ltd. at an interval of 2 cm between grippers so that the long side thereof was in the pulling direction. The tensile and contraction frequencies were set to 1 Hz, the temperature rise rate was set to 3 ° C./min, and the storage elastic modulus at a temperature of 80 ° C. was determined.

(Adhesion measurement)
An acrylic adhesive (thickness 25 μm) is attached to the positive C plate side of the laminate produced in Examples and Comparative Examples, cut into a size of 200 mm in length × 25 mm in width, and the adhesive layer surface is made of soda glass. It was affixed to the substrate.
Next, insert a cutter blade between the polarizer and the λ / 4 retardation layer, peel off 30 mm from the end in the length direction, and peel off the peeled part with a universal tensile tester ["AG-1" manufactured by Shimadzu Corporation. I grabbed it with the grip of "]. The test piece in this state was subjected to JIS K 6854-2: 1999 "Adhesive-Peeling Adhesive Strength Test Method-Part 2: 180 ° Peeling" in an atmosphere at a temperature of 23 ° C. and a relative humidity of 55%. A 180-degree peeling test was performed at a gripping movement speed of 300 mm / min, and an average peeling force over a length of 170 mm excluding 30 mm of the gripped portion was obtained and evaluated based on the following criteria. The results are shown in Table 1.
〇: 180 ° peeling force is 0.5N or more ×: 180 ° peeling force is less than 0.5N

(Durability evaluation)
The laminates produced in Examples and Comparative Examples were cut into a size of 30 mm × 30 mm, and subjected to a moist heat test in which they were left in a moist heat environment with a temperature of 80 ° C. and a relative humidity of 90% for 24 hours. The phase difference value was measured to obtain the absolute value of the difference, and the evaluation was performed according to the following criteria.
Polarization criteria:
⊚: 1.0 or less 〇: 1.0 or more and 3.0 or less ×: 3.0 or more Criteria for in-plane retardation value:
◎: 0.5 or less 〇: 0.5 or more 1.0 or less ×: 1.0 or more For measuring the degree of polarization, an optional accessory is attached to the ultraviolet visible spectrophotometer "UV-2450" manufactured by Shimadzu Corporation. Using a set of a certain "film holder with a polarizer", the transmission spectrum in the transmission axis direction and the absorption axis direction of the polarizing plate in the wavelength range of 380 nm to 780 nm is obtained, and the software attached to the spectrophotometer The degree of polarization was calculated by "UV-Probe".
Measurement of in-plane retardation value, a phase difference measuring apparatus manufactured by Oji Scientific Instruments Co., Ltd. using "KOBRA-WR", was determined plane retardation value _{R e} at a wavelength of 550 nm.
The in-plane retardation value Re is calculated by the following formula:
_Re = (n _{x −} n _y ) × d
(The refractive index in the in-plane slow phase axis direction (the direction in which the refractive index is maximized in _{the in-plane) is n x} , and the refractive index in the in-plane advance phase axis direction (the direction orthogonal to the in-plane slow phase axis direction) is n _y. , The thickness of the laminate is d).

(Preparation of first active energy ray-curable composition)
Each component shown in Table 1 was mixed at the blending ratio (unit: parts by mass) shown in Table 1 and then defoamed to prepare a first active energy ray-curable composition (adhesives 1 to 13). .. The cationic polymerization initiator (B-1) was blended as a 50% propylene carbonate solution, and Table 1 shows the solid content thereof. Table 2 shows the viscosity measurement results and the calorific value measurement results.

(Cation-polymerizable compound (A))
A-1: 3-Ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane (trade name: OXT-221, manufactured by Toa Synthetic Co., Ltd., viscosity 0.012 Pa · s (temperature 25) ℃), refractive index 1.45 (wavelength 589 nm))
A-2: 3', 4'-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Co., Ltd., viscosity 0.25 Pa · s (temperature 25 ° C), refractive index 1.50 (Wavelength 589 nm))
A-3: 1,2-Epoxy-4- (2-oxylanyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol (trade name: EHPE3150, manufactured by Daicel Co., Ltd., viscosity 30 Pa · s Refractive index 1.54 (wavelength 589 nm) exceeding (temperature 25 ° C))
A-4: Neopentyl glycol diglycidyl ether (trade name: EX-211L, manufactured by Nagase ChemteX Corporation, viscosity 0.02 Pa · s (temperature 25 ° C), refractive index 1.45 (wavelength 589 nm))
A-5: 2-ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Corporation, viscosity 0.004 Pa · s (temperature 25 ° C.), refractive index 1.43 (wavelength 589 nm))
A-6: Bisphenol A type epoxy resin (trade name: jER828, manufactured by Mitsubishi Chemical Corporation, viscosity 13 Pa · s (temperature 25 ° C), refractive index 1.57 (wavelength 589 nm))
A-7: Xylylene bisoxetane (trade name: OXT-121, manufactured by Toagosei, viscosity 0.15 Pa · s (temperature 25 ° C), refractive index 1.51 (wavelength 589 nm))

(Photocationic polymerization initiator (B))
B-1: CPI-100P (manufactured by Sun Appro Co., Ltd., 50% by mass solution)

(Photosensitizer (C))
C-1: 9,10-dibutoxyanthracene

(Photosensitizer (D))
D-1: 1,4-diethoxynaphthalene

(Second active energy ray-curable composition)
3', 4'-Epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name: CEL2021P, manufactured by Daicel Co., Ltd.) 70 parts by mass, neopentyl glycol diglycidyl ether (trade name: EX-211L, Nagase ChemteX) 20 parts by mass (manufactured by Nagase ChemteX Corporation), 10 parts by mass of 2-ethylhexyl glycidyl ether (trade name: EX-121, manufactured by Nagase ChemteX Corporation), cationic polymerization initiator (trade name: CPI-100P, Sun Appro Co., Ltd.) The product was mixed with 2.25 parts by mass and 2 parts by mass of 1,4-diethoxynaphthalene in terms of solid content, and then defoamed to prepare a second active energy ray-curable composition.

(Acrylic adhesive sheet A)
(1) Preparation of Materials The following acrylic base polymer (H-1), isocyanate-based cross-linking agent (H-2), and silane coupling agent (H-3) were prepared.
(H-1) Copolymer of butyl acrylate, methyl acrylate, acrylic acid and hydroxyethyl acrylate (H-2) Ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid content concentration 75%) ("Coronate L" (Product name), manufactured by Tosoh Corporation)
(H-3) 3-glycidoxypropyltrimethoxysilane, liquid ("KBM-403" (trade name), manufactured by Shin-Etsu Chemical Co., Ltd.)

(2) Preparation of Adhesive 1 100 parts by mass of the acrylic base polymer (H-1), 0.2 parts by mass of the isocyanate-based cross-linking agent (H-2), and 0 of the silane coupling agent (H-3). Adhesive 1 was prepared by mixing with 2 parts by mass, stirring well, and diluting with ethyl acetate.

(3) Preparation of Acrylic Adhesive Sheet A The pressure-sensitive adhesive 1 prepared above was applied onto a release paper and heat-treated at 90 ° C. for 1 minute to obtain an acrylic pressure-sensitive adhesive sheet A. The obtained adhesive layer was peeled off from the release paper and the thickness was measured and found to be 5 μm. The thickness of the adhesive layer was measured by a contact film thickness meter [trade name "DIGIMICRO MH-15M" manufactured by Nikon Corporation].

(Acrylic adhesive sheet B)
The pressure-sensitive adhesive 1 used for producing the acrylic pressure-sensitive adhesive sheet A is applied onto a release paper so that the thickness of the pressure-sensitive adhesive layer is 25 μm, and heat-treated at 90 ° C. for 1 minute to obtain an acrylic pressure-sensitive adhesive sheet B. rice field.

(Manufacturing of linear polarizing plate)
A polyvinyl alcohol film having a thickness of 20 μm, a degree of polymerization of 2,400, and a saponification degree of 99.9% or more was uniaxially stretched on a roll heated to 125 ° C. at a draw ratio of 4.5 times, and maintained in a tense state, 28. After immersing in water at ° C. for 30 seconds, it was immersed in a dyeing bath at 28 ° C. containing 0.05 parts by mass of iodine and 5 parts by mass of potassium iodide per 100 parts by mass of water for 30 seconds. Then, it was immersed in a boric acid aqueous solution 1 at 64 ° C. containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water for 110 seconds. Then, it was immersed in a boric acid aqueous solution 2 at 67 ° C. containing 5.5 parts by mass of boric acid and 15 parts by mass of potassium iodide per 100 parts by mass of water for 30 seconds. Then, it was washed with pure water at 10 ° C. and dried at 80 ° C. to obtain a polarizing film. The thickness of the obtained polarizing film was 7 μm.

Further, a cycloolefin film (COP film) with a hard coat layer having a thickness of 25 μm is attached to one side of the obtained polarizing film via an aqueous adhesive (thickness 0.1 μm) on the surface opposite to the hard coat layer. They were combined and dried at 90 ° C. to obtain a linear polarizing plate 1 having a laminated structure of COP film / water-based adhesive (adhesive layer) / polarizer. The above-mentioned water-based adhesive consists of 100 parts of water, 3 parts of acetacetyl group-modified polyvinyl alcohol (Z-200, manufactured by Nippon Synthetic), and a water-soluble polyamide epoxy resin (Smiley's resin 650, manufactured by Sumika Chemtex, solid). It was prepared by adding 1.5 parts (an aqueous solution having a concentration of 30%).

(Manufacturing of λ / 4 retardation layer)
A transparent resin by applying a coating liquid containing a rod-shaped and polymerizable nematic liquid crystal monomer to a transparent resin base material for λ / 4 alignment on which an alignment film is laminated and solidifying while maintaining refractive index anisotropy. A retardation-expressing layer having a thickness of 1 μm was obtained on the substrate. The obtained λ / 4 retardation layer had a light transmittance of 0% at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm.

(Manufacturing of positive C plate)
A composition for forming a vertical alignment film was applied to one side of the base film so as to have a thickness of 3 μm, and ^{an ultraviolet ray of 200 mJ / cm 2} was irradiated to prepare a vertical alignment film. A composition for forming a positive C plate was applied onto the vertically oriented layer, dried, and then the coating film was irradiated with ultraviolet rays (UV) to polymerize a polymerizable liquid crystal compound to obtain a positive C plate. The obtained positive C plate had a light transmittance of 80% at a wavelength of 380 nm and a light transmittance of 90% or more at a wavelength of 400 nm.

(Manufacturing of retardation layer laminate)
Corona treatment was applied to the λ / 4 retardation layer and the liquid crystal layer side of the positive C plate. Using the second active energy ray-curable composition, the liquid crystal layers were bonded to each other with a laminator so that the thickness of the cured product layer was 2 μm, and a laminate was obtained.
From the positive C plate side of the obtained laminate, ultraviolet rays were irradiated with an integrated light amount of 400 mJ / cm ² (UV-A) using an ultraviolet irradiation device [manufactured by Fusion UV Systems Co., Ltd.], and the second active energy ray was cured. The sex composition is cured to form a second cured product layer, which is "λ / 4 retardation layer" (first retardation layer) / adhesive layer (second cured product layer) / "positive C plate" (second position). A retardation layer laminate having a laminated structure of (phase difference layer) was obtained.

<Example 1>
The alignment film on the λ / 4 retardation layer side and the transparent resin base material of the obtained retardation layer laminate were peeled off, and the surface of the linearly polarizing plate opposite to the thermoplastic resin film and the λ / 4 retardation layer The liquid crystal layer of No. 1 was bonded to each other using the adhesive 1. The thickness of the first cured product layer made of the adhesive 1 was 2 μm, and the angle formed by the transmission axis of the polarizer and the slow axis of the λ / 4 retardation layer was 45 °.
Next, the alignment film on the positive C plate side and the transparent resin base material are peeled off, and the COP film (thermoplastic resin film) / water-based adhesive (adhesive layer) / polarizer / first cured product layer (cured adhesive 1). Material layer) / "λ / 4 retardation layer" (first retardation layer) / second cured product layer (cured product layer of second active energy ray-curable composition) / "positive C plate" (second place) A laminated body of Example 1 having a laminated structure of (differential layer) was obtained. Table 3 shows the evaluation results of storage elastic modulus, adhesion and durability at 80 ° C.

<Examples 2 to 10 and Comparative Examples 1 to 3>
Laminates of Examples 2 to 11 and Comparative Examples 1 to 3 were prepared in the same manner as in Example 1 except that the adhesives 2 to 10 and the adhesives 11 to 13 were used instead of the adhesive 1. did. The results are shown in Table 3.

<Comparative example 4>
An acrylic pressure-sensitive adhesive sheet A having a pressure-sensitive adhesive layer thickness of 5 μm was bonded to the surface of the linear polarizing plate on the side opposite to the thermoplastic resin film to form the acrylic pressure-sensitive adhesive layer A. The alignment film on the λ / 4 retardation layer side of the retardation layer laminate and the transparent resin base material were peeled off. The liquid crystal layer of the λ / 4 retardation layer of the retardation layer laminate and the acrylic pressure-sensitive adhesive layer A of the linear polarizing plate were bonded together. The angle formed by the transmission axis of the polarizer and the slow axis of the λ / 4 retardation layer was 45 °.
Next, the alignment film on the positive C plate side and the transparent resin base material are peeled off, and the COP film (thermoplastic resin film) / water-based adhesive (adhesive layer) / polarizer / acrylic pressure-sensitive adhesive layer A / "λ / 4 position" Comparison having a laminated structure of "phase difference layer" (first retardation layer) / second cured product layer (cured product layer of second active energy ray-curable composition) / "positive C plate" (second retardation layer) The laminate of Example 1 was obtained. The water resistance of the obtained laminate was evaluated.
The results are shown in Table 3.

<Comparative example 5>
In Comparative Example 4, instead of forming the acrylic pressure-sensitive adhesive layer A having a thickness of 5 μm using the acrylic pressure-sensitive adhesive sheet A, the acrylic pressure-sensitive adhesive layer B having a thickness of 25 μm was formed using the acrylic pressure-sensitive adhesive sheet B. Obtained a laminate of Comparative Example 5 in the same manner as in Comparative Example 4. The results are shown in Table 3.

10 Linear polarizing plate, 11 Polarizing film, 12 1st cured product layer, 13 1st retardation layer, 14 2nd cured product layer, 15 2nd retardation layer, 16 Thermoplastic resin film, 17 Adhesive layer, 18 Adhesive Agent layer, 20 first retardation layer, 21 substrate layer, 22 alignment layer, 23 retardation expression layer, 24 substrate layer, 25 alignment layer, 26 phase difference expression layer, 30 retardation layer, 31 substrate layer, 32 Aligned layer, 33 Phase difference developing layer, 50 Phase difference layer laminated body, 70 laminated body, 100 laminated body

Claims (20)

The polarizing film, the first cured product layer, and the first retardation layer are laminated in this order, the thickness of the first retardation layer is 10 μm or less, and the first cured product layer is The first active energy ray-curable composition comprises a cured product of the first active energy ray-curable composition.
It contains (A) a cationically polymerizable compound and (B) a photocationic polymerization initiator.
The photocationic polymerization initiator (B) contains 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the cationically polymerizable compound (A).
The cationically polymerizable compound (A) is a laminate containing 45% by mass or more of an oxetane compound based on the total mass of the cationically polymerizable compound (A). The first active energy ray-curable composition is
(C) A photosensitizer exhibiting maximum absorption in light having a wavelength longer than 400 nm is contained in an amount of 0.1 part by mass or more and 3.0 part by mass or less with respect to 100 parts by mass of the cationically polymerizable compound (A).
The photosensitizer (C) has the following general formula (I):

(In the formula, R ¹ and R ² represent an alkyl group having 1 to 6 carbon atoms or an alkoxyalkyl group having 2 to 12 carbon atoms independently of each other, and R ³ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. )
The laminate according to claim 1, which comprises an anthracene-based compound represented by. The oxetane compound is 3-ethyl-3-hydroxymethyloxetane, xylylenebis oxetane, 3-ethyl-3- (phenoxymethyl) oxetane, 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy]. According to claim 1 or 2, at least one selected from the group consisting of methyl} oxetane, 3-ethyl-3- (2-ethylhexyloxymethyl) oxetane, and 3-ethyl-3- (cyclohexyloxymethyl) oxetane. The laminate described. The invention according to any one of claims 1 to 3, wherein the cationically polymerizable compound (A) contains 10% by mass or more and 50% by mass or less of an alicyclic epoxy compound based on the total mass of the cationically polymerizable compound (A). Laminated body. The photocationic polymerization initiator (B) is any one of claims 1 to 4, wherein the photocationic polymerization initiator (B) is at least one ionic compound selected from the group consisting of an aromatic sulfonium salt and an aromatic iodonium salt. Laminated body. The laminate according to any one of claims 1 to 5, wherein the first active energy ray-curable composition has a viscosity at 25 ° C. of 200 mPa · s or less. The laminate according to any one of claims 1 to 6, wherein the first active energy ray-curable composition satisfies the following formula (1).
_{(J A / J B) ×} 100 ≧ 60 (%) (1)
_{[J A} is the light transmittance at a wavelength of 380nm is 10% or less than 0%, and light transmittance at a wavelength of 400nm is through the substrate is 30% or more, the first active energy ray-curable composition It represents the amount of heat (unit: mJ / g) measured by a differential scanning calorimeter when irradiated with ultraviolet rays having a peak at a wavelength of 365 nm.
J _B represents the amount of heat (mJ / g) measured by a differential scanning calorimeter when the first active energy ray-curable composition is irradiated with ultraviolet rays having a peak at a wavelength of 365 nm without using a substrate. ] The laminate according to any one of claims 1 to 7, wherein the first cured product layer has a storage elastic modulus of 300 MPa or more at 80 ° C. The laminate according to any one of claims 1 to 8, wherein the thickness of the first cured product layer is 0.5 μm or more and 10 μm or less. The first retardation layer has a light transmittance of 0% or more and 50% or less at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm, according to any one of claims 1 to 9. The laminate described. The first retardation layer has a light transmittance of 0% or more and 10% or less at a wavelength of 380 nm and a light transmittance of 30% or more at a wavelength of 400 nm, according to any one of claims 1 to 10. The laminate described. The second cured product layer and the second cured product layer are laminated in this order on the side of the first retardation layer opposite to the first cured product layer.
The second cured product layer contains a cured product of the second active energy ray-curable composition, and at least one of the first retardation layer and the second retardation layer has a light transmittance of 0% at a wavelength of 380 nm. The laminate according to any one of claims 1 to 11, which is 10% or less and has a light transmittance of 30% or more at a wavelength of 400 nm. The laminate according to claim 12, wherein the first retardation layer is a 1/2 wavelength retardation layer, and the second retardation layer is a 1/4 wavelength retardation layer. The laminate according to claim 12, wherein the first retardation layer is a 1/2 wavelength retardation layer or a 1/4 wavelength retardation layer, and the second retardation layer is a positive C plate. The laminate according to any one of claims 12 to 14, wherein at least one of the first retardation layer and the second retardation layer includes a liquid crystal layer exhibiting retardation. The laminate according to any one of claims 12 to 15, wherein at least one of the first retardation layer and the second retardation layer has a thickness of 0.5 μm or more and 50 μm or less. A circularly polarizing plate containing the laminate according to any one of claims 1 to 16. An image display device including an image display panel and a laminate according to any one of claims 1 to 17, which is arranged on the visual side of the image display panel. The image display device according to claim 18, wherein the laminated body is arranged so that the polarizing film is located on the viewing side. An organic electroluminescence display device including the image display device according to claim 18 or 19.

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