TW202237402A - Optical laminate - Google Patents

Abstract

An object of the present invention is to provide an optical laminate, wherein in the optical laminate provided with a polarizing element having a surface without a protective film, a decrease in the durability of the polarizing element is suppressed, and the adhesion between the polarizing element and other members is high. As a solution, the optical laminate of the present invention has a polarizing element containing a polyvinyl alcohol-based resin and a retardation body containing a cured product of a polymerizable liquid crystal compound; the optical laminate has a first adhesive layer provided in contact with the polarizing element, and a second adhesive layer provided in contact with the retardation body between the polarizing element and the retardation body.

Description

Optical laminate

The present invention relates to an optical layered body, and also to an image display device having the optical layered body.

Conventionally, in image display devices, a method of arranging an optical layered body having anti-reflection properties on the viewing side of an image display panel is used to prevent degradation of visibility due to reflection of external light.

A circular polarizing plate composed of a polarizer and a phase difference body is known as an optical laminate having antireflection performance.

In the circular polarizer, the external light toward the image display panel is converted into linear polarized light by the polarizer, and then converted into circular polarized light by the phase difference layer. Although the external light converted into circularly polarized light can be reflected on the surface of the image display panel, the rotation direction of the polarized surface will be reversed during the reflection, and it can be blocked by the polarizer after being converted into linearly polarized light by the phase difference body. . As a result, emission to the outside can be significantly suppressed.

When an image display device is used in a harsh environment, there is a problem that the optical characteristics of the polarizer are easily degraded. As described in JP 2013-105036 A, a polarizer with excellent durability can be obtained by increasing the content of boric acid in the polarizer.

[Prior Art Literature]

[Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2013-105036

In the optical laminate, the durability of the polarizer can be improved by adhering protective films on both sides of the polarizer. The configuration of providing a protective film on only one side of the polarizer is advantageous for thinning, but it has a problem of low durability when compared with the configuration of adhering protective films on both sides of the polarizer. In addition, the present inventors have found that a configuration in which a protective film is provided on only one side of a polarizer has a problem of low adhesion between other members such as retarders laminated on the surface of the protective film without a polarizer.

The object of the present invention is to provide an optical layered body having a polarizer without a protective film on the surface, which can suppress the durability of the polarizer from decreasing and has high adhesion between the polarizer and other members. .

The present invention provides an optical layered body, an image display device, and a method for producing an optical layered body shown below.

[1] An optical laminate comprising a polarizer comprising a polyvinyl alcohol-based resin and a retarder comprising a cured product of a polymerizable liquid crystal compound, wherein,

Between the polarizer and the retarder, there are a first adhesive layer provided in contact with the polarizer and a second adhesive layer provided in contact with the retarder.

[2] The optical laminate according to [1], wherein the first adhesive layer has a tensile modulus of 2,000 MPa or more at a temperature of 25°C,

The tensile elastic modulus of the second adhesive layer at a temperature of 25° C. is 1,900 MPa or less.

[3] The optical laminate according to [1] or [2], wherein

The first adhesive layer is a hardened layer of a cationic polymerizable adhesive,

The second adhesive layer is a hardened layer of a radically polymerizable adhesive.

[4] The optical laminate according to any one of [1] to [3], wherein the phase difference body includes a λ/4 layer.

[5] The optical laminate according to any one of [1] to [4], which is a polarizing plate for antireflection.

[6] An image display device comprising an image display panel and the optical laminate according to [5] disposed on the front surface of the image display panel.

[7] The image display device according to [5], wherein the image display panel is an organic EL display panel.

[8] A method for manufacturing an optical layered body, which is the method for manufacturing an optical layered body according to any one of [1] to [5], comprising:

a step of applying a first adhesive on the surface of the polarizer, and curing the first adhesive to form a first adhesive layer, and

A step of forming the first adhesive layer and the retardation bulk layer formed on the surface of the polarizer via a second adhesive, and curing the second adhesive to form the second adhesive layer.

According to the present invention, it is possible to provide an optical laminate including a polarizer without a protective film on the surface, which can suppress the deterioration of the durability of the polarizer and improve the adhesion between the polarizer and other members.

100: Optical laminate

130: linear polarizer

131: protective layer

132: Polarizer

140:Phase difference body

141: The first retardation layer

142: The second retardation layer

143: interlayer adhesive layer

150: 1st adhesive layer

160: The second adhesive layer

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

Hereinafter, although the embodiments of the present invention will be described with reference to the drawings, the present invention is not limited to the scope of the following embodiments. In order to facilitate the understanding of each constituent element, all the following drawings are presented with appropriate scale adjustments. The scale ratio of each constituent element shown in the figure may not be consistent with the actual constituent element scale.

<Optical laminate>

The optical layered body of the present invention has a polarizer containing a polyvinyl alcohol-based resin and a phase difference body containing a cured product of a liquid crystal compound, and has a first polarizer disposed in contact with the polarizer between the polarizer and the phase difference body. The adhesive layer is a second adhesive layer provided in contact with the phase difference body. In the optical layered body of the present invention, since the first adhesive layer and the second adhesive layer exist, the decrease in the durability of the polarizer can be suppressed, and the adhesion between the polarizer and other members can be improved.

One embodiment of the optical layered body of the present invention will be described with reference to FIG. 1 . The optical laminate 100 shown in FIG. 1 has a linear polarizer 130 , a first adhesive layer 150 , a second adhesive layer 160 , and a phase difference body 140 in this order.

The linear polarizer 130 includes a protective layer 131 and a polarizer 132 in this order from the front side. The retardation body 140 includes a first retardation layer and a second retardation layer 142 from the side of the linear polarizing plate 130 . The first retardation layer 141 and the second retardation layer 142 can be bonded together with an interlayer adhesive layer.

The optical layered body may be, for example, a square in a plan view, preferably a square having a long side and a short side, and more preferably a rectangle. The layers constituting the optical laminate can be rounded corners, edges processed with notches or perforated.

The optical layered body can be used for an image display device etc., for example. The image display device is not particularly limited, and examples thereof include organic electroluminescence (organic EL) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, and electroluminescent display devices.

[Linear polarizer]

The linear polarizer 130 can be attached to a protective layer 131 of the polarizer 132 . The linear polarizer 130 has a property of allowing linearly polarized light having a vibration plane perpendicular to the absorption axis to pass therethrough when non-polarized light is incident. The linear polarizing plate 130 contains a polyvinyl alcohol (hereinafter, abbreviated as “PVA”) resin as a polarizer 132 .

The thickness of the linear polarizer 130 is, for example, not less than 2 μm and not more than 100 μm, preferably not less than 5 μm and not more than 60 μm.

[Polarizer]

As the polarizer, a polarizer obtained by dyeing a polyvinyl alcohol-based resin film with iodine and stretching it uniaxially can be used.

Polyvinyl alcohol-based resins can be produced by saponifying polyvinyl acetate-based resins. The polyvinyl acetate-based resin may be a copolymer of vinyl acetate and other monomers that can be copolymerized with vinyl acetate in addition to a homopolymer of vinyl acetate. Other monomers that can be copolymerized with vinyl acetate include, for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, acrylamides having an ammonium group, and the like.

The degree of saponification of polyvinyl alcohol-based resins is usually about 85 to 100 mole percent, preferably above 98 mole percent. The polyvinyl alcohol resin can be modified, 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 about 1,000 to 10,000, preferably about 1,500 to 5,000. The average degree of polymerization of the polyvinyl alcohol-based resin can be obtained in accordance with JIS K 6726 (1994). When the average degree of polymerization is less than 1,000, it will be difficult to obtain favorable polarizing performance, and when it exceeds 10,000, the processability of the film will be poor.

A method for producing a linear polarizing plate containing another polyvinyl alcohol-based resin film includes first preparing a base film, coating a solution of a resin such as a polyvinyl alcohol-based resin on the base film, and drying to remove the solvent. , and the step of forming a resin layer on the base film. In addition, a primer layer may be formed in advance on the surface of the resin layer on which the base film can be formed. As the base film, a resin film such as PET or a resin film that can be used on a protective layer described later can be used. As a material of the primer layer, a resin cross-linked with a hydrophilic resin used in a linear polarizing plate may be mentioned.

Next, adjust the amount of solvent such as moisture in the resin layer as needed, and then uniaxially stretch the base film and the resin layer, and then dye the resin layer with a dichroic dye such as iodine to make the dichroic dye adsorb and align on the resin. layer. Next, if necessary, the resin layer on which the aligned dichroic dye is adsorbed is treated with a boric acid aqueous solution, and a washing step of washing away the boric acid aqueous solution is performed. As a result, a polarizer containing a polyvinyl alcohol-based resin and a resin layer in which a dichroic dye is adsorbed and aligned in a polyvinyl alcohol-based resin film can be produced. Each step can employ a known method.

The uniaxial stretching of the base film and the resin layer may be performed before dyeing, may be performed during dyeing, or may be performed during boric acid treatment after dyeing, and uniaxial stretching may be performed separately in these multiple stages. The base film and the resin layer may be uniaxially stretched in the MD direction (film transport direction). In this case, the uniaxial stretching may be performed between rolls having different numbers of turns, or may be uniaxially stretched using a heated roll. In addition, the base film and the resin layer can also be oriented in the TD direction (The direction perpendicular to the film transport direction) is uniaxially stretched. In this case, a so-called tenter method can be used. In addition, the stretching of the base film and the resin layer may be dry stretching in which the resin layer is stretched in the air, or wet stretching in which the resin layer is stretched in a solvent. The elongation ratio is more than 4 times to express the performance of the polarizer layer, preferably more than 5 times, especially preferably more than 5.5 times. The upper limit of the elongation ratio is not particularly limited, but it is preferably 8 times or less from the viewpoint of preventing breakage.

The polarizer produced by the above method can also be used as a linear polarizer with the base film peeled off or with the base film. According to the above method, since the base film can be peeled off, the linear polarizing plate can be further reduced in thickness.

The thickness of the polarizer including the polyvinyl alcohol-based resin film is, for example, 2 μm or more and 40 μm or less. The thickness of the polarizer may be 5 μm or more, 20 μm or less, 15 μm or less, or 10 μm or less.

[The protective layer]

The protective layer 131 has the function of protecting the surface of the polarizer 132 . In the optical layered body, the linear polarizing plate 130 is arranged so that the protective layer 131 is on the front side of the polarizing plate 132 . The linear polarizer 130 may not have the protective layer 131 .

The protective layer 131 can be an organic layer or an inorganic layer. The protection layer 131 can be a base film used in the process of the polarizer layer 132 . The organic layer can be formed using a composition for forming a protective layer, such as a (meth)acrylic resin composition, an epoxy resin composition, a polyimide resin composition, and the like. The composition for forming a protective layer may be an active energy ray curing type or a thermosetting type. The inorganic layer can be formed of, for example, silicon dioxide. In the case where the protective layer 131 is an organic layer, the protective layer can be called a hard coat layer.

When the protective layer 131 is an organic layer, for example, an active energy ray-curable protective layer-forming composition is coated on a base film, and the protective layer is formed by irradiating active energy to harden it. The base film can apply the description of the above-mentioned base film. The base film is usually peelable and removable. The method of applying the composition for forming a protective layer includes, for example, a spin coating method and the like. When the protective layer 131 is an inorganic layer, the protective layer can be formed by, for example, a sputtering method, a vapor deposition method, or the like. When the protective layer 131 is an organic layer or an inorganic layer, the thickness of the protective layer 131 can be, for example, not less than 0.1 μm and not more than 10 μm, preferably not less than 0.5 μm and not more than 5 μm.

For the protective layer 131 , for example, a resin film excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, and extensibility can be used. The resin film may be a thermoplastic resin film. Specific examples of such resins include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether resins; polyethylene resins; polycarbonate resins; Ester resin; polyamide resin such as nylon or aromatic polyamide; polyimide resin; polyolefin resin such as polyethylene, polypropylene, ethylene-propylene copolymer; ring system and cyclic polyamide with norbornene structure Olefin resins (also called norbornene-based resins); (meth)acrylic resins; polyarylate resins; polystyrene resins; For example, when the double-layer layer of the polarizer layer has a protective layer, the two protective layers can be of the same type or different types. The thickness of the resin film can be, for example, not less than 3 μm and not more than 50 μm, preferably not less than 5 μm and not more than 30 μm.

[1st adhesive layer, 2nd adhesive layer]

The first adhesive layer 150 is provided in contact with the surface of the polarizer 132 opposite to the protective layer 131 side. The first adhesive layer 150 is formed by curing the first adhesive. The tensile modulus of the first adhesive layer 150 at a temperature of 25° C. is preferably 2,000 MPa or higher, more preferably 2,100 MPa or higher, and more preferably 2,200 MPa or higher. The tensile elastic modulus of the first adhesive layer 150 at a temperature of 25° C. is, for example, 4,000 MPa or less. Down. Since the tensile modulus of the first adhesive layer 150 is within the above-mentioned range, dichroic dyes such as iodine adsorbed and aligned in the polarizer 132 can be prevented from flowing out from the polarizer 132, and the durability of the polarizer 132 can be improved. , can improve the durability of the optical properties of the optical laminate.

The second adhesive layer 160 is provided in contact with the surface of the phase difference body 140 on the side opposite to the linear polarizer 130 . The second adhesive layer 160 is formed by curing the second adhesive. The tensile modulus of the second adhesive layer 160 at a temperature of 25° C. is preferably not more than 1,900 MPa, more preferably not more than 1,800 MPa, and more preferably not more than 1,700 MPa. The tensile elastic modulus of the second adhesive layer 160 at a temperature of 25° C. is, for example, 100 MPa or more. Since the tensile modulus of the second adhesive layer 160 is within the above range, in the optical layered body 100, the adhesiveness between the polarizer 132 and the phase difference body 140 can be improved. In the case where the surface of the polarizer 132 of the phase difference body 140 that is opposite to the polarizer 132 contains a cured product of a polymerizable liquid crystal compound, although there is a problem that the adhesion between the polarizer 132 and the phase difference body 140 is significantly low, but According to the present invention, even when the surface of the phase difference body 140 on the opposite side to the polarizer 132 contains the cured product of the polymerizable liquid crystal compound, the adhesiveness can be improved.

The method of measuring the tensile modulus of the first adhesive layer 150 and the second adhesive layer 160 is in accordance with the method described in the examples described later. The optical layered body 100 may further include another adhesive layer between the second adhesive layer 150 and the second adhesive layer 160 .

As the first adhesive forming the first adhesive layer 150 and the second adhesive forming the second adhesive layer 160, it is preferable to use a curable adhesive containing a curable (polymerizable) compound. The curable adhesive is preferably an active energy ray-curable adhesive that can be cured by heating or irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays. Examples of the curable adhesive include radically polymerizable adhesives containing a radically polymerizable compound and cationically polymerizable adhesives containing a cationically polymerizable compound.

From the viewpoint of easy formation of the first adhesive layer 150 having the above-mentioned tensile modulus, the first adhesive is preferably a cationic polymerizable adhesive, and may contain both a cationic polymerizable compound and a radical polymerizable compound. . From the viewpoint of easy formation of the second adhesive layer 160 having the above tensile modulus, the second adhesive is preferably a radically polymerizable adhesive, and may contain both a radically polymerizable compound and a cationic polymerizable compound. By. When the surface of the phase difference body 140 that can form the second adhesive layer 160 contains a cured product of a radically polymerizable compound, since the second adhesive is a radically polymerizable adhesive, the phase difference body 140 and the polarizer can be The closeness between 132 is further improved. The tensile modulus of the first adhesive layer 150 and the second adhesive layer 160 can be adjusted according to the type of adhesive, the degree of hardening of the adhesive, and the like. In the first adhesive layer 150, the degree of hardening of the first adhesive is preferably 98% or higher, more preferably 99% or higher. In the second adhesive layer 160, the curing degree of the second adhesive is preferably 90% or more, more preferably 92% or more.

The thickness of the first adhesive layer 150 and the second adhesive layer 160 is preferably 20 μm or less, more preferably 15 μm or less, more preferably 10 μm or less, may be 5 μm or less, and may be 0.05 μm or more. It can be 0.5 μm or more. When using an active energy ray-curing adhesive, the viscosity should be one that can be applied by various methods, but the viscosity at a temperature of 25°C is preferably in the range of 10 to 1,000 mPa‧sec, and 20 to 1,000 mPa‧sec. The range of 500mPa‧sec is better. 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 becomes difficult to flow, and it tends to be difficult to obtain a uniform coating film without unevenness. The viscosity referred to here is a value measured at 10 rpm after adjusting the temperature of the adhesive to 25° C. with an E-type viscometer.

(Cationically polymerizable adhesive)

The cationically polymerizable adhesive contained in the cationically polymerizable adhesive can be a compound that is cationically polymerized and hardened by irradiation or heating of active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, or Examples of oligomers include epoxy compounds, propylene oxide compounds, vinyl compounds, and the like. Among them, preferred cationically polymerizable compounds are epoxy compounds. The epoxy compound refers to a compound having one or more epoxy groups in the molecule, preferably having two or more epoxy groups. An epoxy compound may be used individually by 1 type, and may use 2 or more types together. Examples of epoxy compounds include alicyclic epoxy compounds, aromatic epoxy compounds, hydrogenated epoxy compounds, and aliphatic epoxy compounds. Among them, the epoxy compound preferably contains an alicyclic epoxy compound or an aliphatic epoxy compound, and more preferably contains an alicyclic epoxy compound, from the viewpoints of weather resistance, curing speed, and adhesiveness.

The alicyclic epoxy compound is a compound having one or more epoxy groups bonded to an alicyclic ring in the molecule. The "epoxy group bonded to the alicyclic ring" refers to the bridging oxygen atom -O- in the structure represented by the following formula (I). In the following formula (I), m is an integer of 2-5.

An alicyclic epoxy compound can be formed by combining a group obtained by removing one or more hydrogen atoms in (CH ₂ ) _m in the above formula (I) with another chemical structure. One or more hydrogen atoms in (CH ₂ ) _m may be appropriately substituted with linear alkyl groups such as methyl or ethyl.

Among them, the alicyclic epoxy compound having an epoxy cyclopentane structure [m=3 in the above formula (I)] or an epoxy cyclohexane structure [m=4 in the above formula (I)], The cured product has a high glass transition temperature and is also advantageous in terms of adhesion between the polarizing film and the protective film. Specific examples of the alicyclic epoxy compound are disclosed below. Here, the compound names are first listed, and then individual corresponding chemical formulas are created, and the same symbols are assigned to the compound names and the corresponding chemical formulas.

A: 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate,

B: 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate,

C: Ethylene bis(3,4-epoxy cyclohexane carboxylate),

D: Bis(3,4-epoxycyclohexylmethyl) adipate,

E: Bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate,

F: Diethylene glycol bis(3,4-epoxycyclohexyl methyl ether),

G: Ethylene glycol bis(3,4-epoxycyclohexyl methyl ether),

H: 2,3,14,15-diepoxy-7,11,18,21-tetraoxatrispiro[5.2.2.5.2.2]eicosane,

I: 3-(3,4-epoxycyclohexyl)-8,9-epoxy-1,5-dioxaspiro[5.5]undecane,

J: 4-vinylcyclohexene dioxide,

K: limonene dioxide,

L: Bis(2,3-epoxycyclopentyl) ether,

M: dicyclopentadiene dioxide.

The aromatic epoxy compound is a compound having an aromatic ring and an epoxy group in the molecule. Its specific examples include bisphenol type epoxy compounds such as diglycidyl ether of bisphenol A, diglycidyl ether of bisphenol F, and diglycidyl ether of bisphenol S or their oligomers; phenol novolak epoxy resin, formaldehyde Novolac epoxy resins such as phenolic novolac epoxy resins, hydroxybenzoic phenolic novolac epoxy resins; glycidyl ethers of 2,2',4,4'-tetrahydroxydiphenylmethane, 2,2',4,4 Polyfunctional epoxy compounds such as glycidyl ether of '-tetrahydroxybenzophenone; polyfunctional epoxy resins such as epoxidized polyvinyl phenol.

Hydrogenated epoxy compounds are glycidyl ethers of polyhydric alcohols with alicyclic rings, which can have nuclear hydrogenated polyhydric alcohols obtained by selective hydrogenation of aromatic rings in the presence of catalysts and under pressure. Glycidyl etherification of hydroxyl compounds. Specific examples of aromatic polyols include bisphenol compounds such as bisphenol A, bisphenol F, and bisphenol S; Multifunctional compounds such as hydroxydiphenylmethane, tetrahydroxybenzophenone, and polyvinylphenol. Obtained by hydrogenation of aromatic rings of aromatic polyols The alicyclic polyol reacts with epichlorohydrin to make glycidyl ether. Preferable ones among hydrogenated epoxy compounds include diglycidyl ether of hydrogenated bisphenol A.

The aliphatic epoxy compound is a compound having at least one oxirane ring (three-membered cyclic ether) bonded to an aliphatic carbon atom in the molecule. For example, monofunctional epoxy compounds such as butyl glycidyl ether and 2-ethylhexyl glycidyl ether; 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl Bifunctional epoxy compounds such as diol diglycidyl ether; trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether and other trifunctional epoxy compounds; 4-vinylcyclohexene dioxide Epoxy compounds having an epoxy group directly bonded to an alicyclic ring and an oxirane ring bonded to an aliphatic carbon atom, such as limonene dioxide, etc. Among them, from the point of view of adhesion between the polarizing film and the protective film, it is a bifunctional epoxy compound (also called aliphatic bicyclic ring) having two oxirane rings bonded to aliphatic carbon atoms in the molecule. Oxygen compounds) are preferred. Such a suitable aliphatic diepoxy compound can be represented by following formula (II), for example.

Y in the above formula (II) is an alkylene group with 2 to 9 carbons, an alkylene group with 4 to 9 total carbons having ether bonds, or a divalent hydrocarbon group with 6 to 18 carbons having an alicyclic structure .

The aliphatic diepoxy compound represented by the above-mentioned formula (II) specifically has diglycidyl ether of alkanediol, diglycidyl ether of oligomeric alkanediol with a repeating number of about 4, or alicyclic diol. diglycidyl ether.

Specific examples of the diol (ethylene glycol) that can form the aliphatic diepoxy compound represented by the above formula (II) are disclosed below. Alkanediols include ethylene glycol, propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 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-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol Wait.

The oligoalkylene glycol includes diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and the like. The alicyclic diol includes cyclohexanediol, cyclohexanedimethanol, and the like.

The propylene oxide compound, one of the cationic polymerizable compounds, is a compound containing one or more propylene oxide rings (propylene oxide group) in the molecule, and its specific example includes 3-ethyl-3-hydroxymethyl propylene oxide (also known as propylene oxide alcohol), 2-ethylhexyl propylene oxide, 1,4-bis[{(3-ethyl oxide propylene-3-yl)methoxy}methyl]benzene (also known as di Toluene dipropylene oxide), 3-ethyl-3[{(3-ethyloxypropylene-3-yl)methoxy}methyl]epoxypropylene, 3-ethyl-3-(phenoxy Methyl) propylene oxide, 3-(cyclohexyloxy)methyl-3-ethyl propylene oxide. A propylene oxide compound may be used as a main component of a cation polymerizable compound, or may be used together with an epoxy compound. By using propylene oxide compound at the same time, the curing speed and adhesion can be improved.

Vinyl compounds that can serve as cationic polymerizable compounds include aliphatic or alicyclic vinyl ether compounds, and specific examples thereof include, for example, n-pentyl vinyl ether, isopentyl vinyl ether, and n-hexyl vinyl ether. , n-octyl vinyl ether, 2-ethylhexyl vinyl ether, n-dodecyl vinyl ether, stearyl vinyl ether, oleyl vinyl ether and other alkyl or alkenyl groups with 5 to 20 carbon atoms Alcohol vinyl ether; 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether and other vinyl ethers containing hydroxyl groups; cyclohexyl vinyl ether, 2-methyl Vinyl ethers of monoalcohols with aliphatic or aromatic rings such as cyclohexyl vinyl ether, cyclohexyl methyl vinyl ether, and benzyl vinyl ether; glycerol monovinyl ether, 1,4-butanedi Alcohol monovinyl ether, 1,4-butanediol divinyl ether, 1,6-hexanediol divinyl ether, neopentyl glycol divinyl ether, pentaerythritol divinyl ether, isopentyl Tetraol Tetravinyl Ether, Trimethylolpropane Diethylene Alkenyl ether, trimethylolpropane trivinyl ether, 1,4-dihydroxycyclohexane monovinyl ether, 1,4-dihydroxycyclohexane divinyl ether, 1,4-dihydroxymethyl Mono-to-polyvinyl ethers of polyols such as cyclohexane monovinyl ether and 1,4-dihydroxymethylcyclohexane divinyl ether; diethylene glycol divinyl ether, triethylene glycol divinyl ether , Diethylene glycol monobutyl monovinyl ether and other polyalkylene glycol mono-divinyl ethers; glycidyl vinyl ether, ethylene glycol vinyl ether methacrylate and other vinyl ethers. The vinyl compound can be used as the main component of the cationically polymerizable compound, and an epoxy compound, or an epoxy compound and a propylene oxide compound can be used together. When vinyl compounds are used together, the curing speed can be increased and the viscosity of the adhesive can be reduced.

The cationically polymerizable adhesive may contain other curable compounds other than the above. Specific examples of other curable compounds include lactone compounds, cyclic acetal compounds, cyclic thioether compounds, and spirocyclic orthoester compounds, other cationic polymerizable compounds other than the above.

When the first adhesive is a cationic polymerizable adhesive, from the viewpoint of suppressing the outflow of dichroic dyes such as iodine from the polarizer 132, when the total amount of the curable compound contained in the first adhesive is 100% by mass , the content of cationic polymerizable compounds (the content of all cationic polymerizable compounds contained in the first adhesive agent, when two or more cationic polymerizable compounds are included, the total content of these) is 80% by weight The above is preferable, more preferably 90% by weight or more, and more preferably 100% by weight.

The first adhesive may be active energy ray curable or thermosetting, preferably active energy ray curable. When imparting active energy ray curability to the first adhesive, it is preferable to mix a photocationic polymerization initiator in the adhesive. Photocationic polymerization initiators are those that can generate cationic species or Lewis acids by irradiation of active energy rays such as visible light, ultraviolet rays, X-rays, or electron beams, and initiate the polymerization of cationic hardening compounds. Since the photocationic polymerization initiator is based on light It acts as a catalyst, so it has excellent storage stability and workability even if it is mixed in a photocation-curable compound. Examples of compounds that generate cationic species or Lewis acids by irradiation with active energy rays include onium salts of aromatic iodonium salts or aromatic sulfonium salts, aromatic oxadiazolium salts, and iron-arene complexes. Wait.

The aromatic iodonium salt is a compound having a diaryliodonium cation, and a representative example of the cation includes a diphenyliodonium cation. Aromatic sulfonium salts are compounds having triarylsulfonium salt cations. Representative examples of such cations include triphenylsulfonium cations and 4,4'-bis(diphenylsulfonium)diphenylsulfonium cations. cations etc. The aromatic oxadiazolium salt is a compound having a oxadiazolium cation, and a representative example of the cation includes a benzodiazolium cation. In addition, a typical example of the iron-arene complex is cyclopentadienyl iron (II) arene cation complex.

The cationic system shown above and an anion make a pair (anion) and constitute a photocationic polymerization initiator. Examples of the anion constituting the photocationic polymerization initiator include special phosphorus anion [(Rf) _n PF _6-n ] ^- , hexafluorophosphate anion PF ₆ ^- , hexafluoroantimonate anion SbF ₆ ^- , pentafluoroanion Fluorohydroxyantimonate anion SbF ₅ OH ^- , hexafluoroarsenate anion AsF ₆ ^- , tetrafluoroborate anion BF ₄ ^- , tetrakis(pentafluorophenyl) borate anion B(C ₆ F ₅ ) ₄ ^- etc. . Among them, the special phosphorus-based anion [(Rf) _n PF _6-n ] ^- is preferable from the viewpoint of the curability of the cationic polymerizable compound and the safety of the obtained adhesive layer.

A photocationic polymerization initiator may use only 1 type individually, and may use 2 or more types together. Among them, aromatic sulfonium salts can be preferably used because they have ultraviolet absorption characteristics even in the wavelength region around 300 nm, and can provide cured products having excellent curability, good mechanical strength, and good adhesive strength.

The compounding quantity of a photocationic polymerization initiator is usually 0.5-10 weight part with respect to 100 weight part of cationic polymerizable compounds, Preferably it is 6 weight part or less. Due to the preparation of 0.5 parts by weight or more of photocationic polymerization initiator, the cationic polymerizable compound can be fully hardened, and the obtained optical laminate can be The body imparts high mechanical strength and bonding strength. On the other hand, if the amount is too large, the ionic substances in the cured product will increase, which may increase the hygroscopicity of the cured product and reduce the durability of the polarizer. Examples of photocurable resins include (meth)acrylic resins, urethane resins, (meth)acrylate urethane resins, epoxy resins, silicone resins, and the like. Examples of water-soluble polymers include poly(meth)acrylamide polymers; polyvinyl alcohol, ethylene-vinyl alcohol copolymers, ethylene-vinyl acetate copolymers, (meth)acrylic acid or anhydrides thereof - Vinyl alcohol-based polymers such as vinyl alcohol copolymers; carboxyvinyl-based polymers; polyvinylpyrrolidone; starches; sodium alginate; polyethylene oxide-based polymers, etc.

(radical polymerizable adhesive)

The radically polymerizable compound contained in the radically polymerizable adhesive is a compound or oligomer that can undergo radical polymerization hardening by irradiation or heating of active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, Specifically, compounds having an ethylenically unsaturated bond are exemplified. Compounds having an ethylenically unsaturated bond include (meth)acrylic compounds having one or more (meth)acryl groups in the molecule, such as styrene, styrenesulfonic acid, vinyl acetate, Vinyl propionate, vinyl compounds of N-vinyl-2-pyrrolidone, and the like. Among them, preferable radical polymerizable compounds are (meth)acrylic compounds.

Examples of (meth)acrylic compounds include (meth)acrylate monomers having at least one (meth)acryloxy group in the molecule, (meth)acrylamide monomers, and two or more types containing functional groups. A (meth)acryl oligomer having at least 2 (meth)acryl groups in the molecule obtained by reacting a compound containing a (meth)acryl group. The (meth)acrylic oligomer is preferably a (meth)acrylate oligomer having at least 2 (meth)acryloxy groups in the molecule. A (meth)acrylic compound may be used individually by 1 type, and may use 2 or more types together.

Examples of (meth)acrylate monomers include monofunctional (meth)acrylate monomers having one (meth)acryloxy group in the molecule, and 2-functional (meth)acrylate monomers having two (meth)acryloxy groups in the molecule. Functional (meth)acrylate monomer, polyfunctional (meth)acrylate monomer having 3 or more (meth)acryloxy groups in the molecule.

Examples of monofunctional (meth)acrylate monomers are alkyl (meth)acrylates. In the alkyl (meth)acrylate, the alkyl group should just be a linear or branched chain having 3 or more carbon atoms. When specific examples of alkyl (meth)acrylates are given, methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylate base) isobutyl acrylate, tertiary butyl (meth)acrylate (meth), 2-ethylhexyl acrylate, etc. In addition, aralkyl (meth)acrylates such as benzyl (meth)acrylate; (meth)acrylates of terpene alcohols such as isobornyl (meth)acrylate; (meth)acrylates such as tetrahydrofuran (meth)acrylate (Meth)acrylates with tetrahydrofuryl structure; such as cyclohexyl (meth)acrylate, cyclohexyl methacrylate, dicyclopentyl acrylate, dicyclopentenyl (meth)acrylate, 1,4-cyclohexanedimethanol monoacrylate (meth)acrylic ester with cycloalkyl in the alkyl part; such as (meth)acrylic acid N,N-dimethylaminoethyl (methyl) Aminoalkyl acrylates; such as 2-phenoxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxy poly Ethylene glycol (meth)acrylate (meth)acrylate having an ether bond in the alkyl portion can also be used as a monofunctional (meth)acrylate monomer.

Moreover, the monofunctional (meth)acrylate which has a hydroxyl group in an alkyl part, or the monofunctional (meth)acrylate which has a carboxyl group in an alkyl part can also be used. Specific examples of monofunctional (meth)acrylates with hydroxyl groups on the alkyl sites include 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, (meth)acrylic acid 4-Hydroxybutyl ester, 2-Hydroxy-3-phenoxypropyl (meth)acrylate, Trimethylolpropane mono(meth)acrylate, Pentaerythritol mono(meth)acrylate. A single carboxyl group on the alkyl site Specific examples of functional (meth)acrylates include 2-carboxyethyl (meth)acrylate, ω-carboxy-polylactone (n≒2) mono(meth)acrylate, 1-[(methyl) Acryloxyethyl]phthalic acid, 1-[2-(meth)acryloxyethyl]hexahydrophthalic acid, 1-[2-(meth)acryloxyethyl ]succinic acid, 4-[2-(meth)acryloxyethyl]trimellitic acid, N-(meth)acryloxy-N',N'-dicarboxymethyl-p-extene phenylenediamine.

The (meth)acrylamide monomer system is preferably (meth)acrylamide with a substituent at the N-position. The representative example of the substituent at the N-position is an alkyl group, but it can also be combined with (methyl) The nitrogen atoms of the acrylamide simultaneously form a ring, and this ring may have oxygen atoms as ring members in addition to the carbon atoms and the nitrogen atoms of the (meth)acrylamide. In addition, a substituent such as an alkyl group or a pendant oxygen (=O) may be bonded to the carbon atoms constituting the ring.

Specific examples of N-substituted (meth)acrylamide include N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide Amines, N-n-butyl(meth)acrylamide, N-tert-butyl(meth)acrylamide, N-alkyl(meth)acrylamide of N-ethyl(meth)acrylamide Amides; N,N-dialkyl(meth)acrylamides such as N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide. In addition, the N-substituent can be an alkyl group having a hydroxyl group, examples of which include N-hydroxymethyl (meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N-( 2-hydroxypropyl) (meth)acrylamide, etc. In addition, specific examples of N-substituted (meth)acrylamides forming the above-mentioned 5-membered ring or 6-membered ring include N-acrylylpyrrolidine, 3-acrylyl-2-oxazolidinone ), 4-acrylmorpholine, N-acrylpiperidine, N-methacrylpiperidine, etc.

Bifunctional (meth)acrylate monomers include alkanediol di(meth)acrylate, polyoxyalkylene diol di(meth)acrylate, halogen-substituted alkanediol di(meth)acrylate, Di(meth)acrylates of aliphatic polyhydric alcohols, di(meth)acrylates of hydrogenated dicyclopentadiene or tricyclodecanedodecanol, di(meth)acrylates of dioxanediol or dioxanediakanol Meth)acrylate, di(meth)acrylate of bisphenol A or bisphenol F alkylene oxide addendum, bisphenol A or bisphenol F epoxy di(meth)acrylate, etc.

When citing more specific examples of bifunctional (meth)acrylates, there are ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol Alcohol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, Neopentyl glycol di(meth)acrylate , trimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, diethylene glycol di(meth)acrylate ester, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate Meth)acrylates, polytetramethylene glycol di(meth)acrylates, silicone di(meth)acrylates, di(meth)acrylates of neopentyl glycol hydroxypivalate, 2, 2-bis[4-(meth)acryloxyethoxyethoxyphenyl]propane, 2,2-bis[4-(meth)acryloxyethoxyethoxyethoxycyclohexyl] Propane, hydrogenated dicyclopentadiene di(meth)acrylate, tricyclodecane dimethyl di(meth)acrylate, 1,3-dioxane-2,5-diyl di(meth)acrylate Acrylate [aka: dioxanediol di(meth)acrylate], acetal compound of hydroxypivalaldehyde and trimethylolpropane [chemical name: 2-(2-hydroxy-1,1-di Methylethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane] di(meth)acrylate, ginseng(hydroxyethyl)isocyanurate di(methyl ) acrylate, etc.

Representatives of multifunctional (meth)acrylate monomers with more than three functions include glycerin tri(meth)acrylate, alkoxylated glycerin tri(meth)acrylate, trimethylolpropane tri(methyl) Acrylates, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate trifunctional or higher aliphatic Poly(meth)acrylates of polyols, other (meth)acrylates of halogen-substituted polyols with more than three functions, tri(meth)acrylates of glycerol alkylene oxide addenda, trihydroxy First Tri(meth)acrylate, 1,1,1-paraffin[(meth)acryloxyethoxyethoxy]propane, tri(hydroxyethyl)iso Cyanurate tri(meth)acrylate, etc.

On the other hand, among (meth)acrylic oligomers, there are urethane (meth)acrylic oligomers, polyester (meth)acrylic oligomers, epoxy (meth)acrylic oligomers, etc. .

Ester (meth)acrylic acid oligomer is a compound with amine ester bond (-NHCOO-) and at least 2 (meth)acrylic acid groups in the molecule. Specifically, there is a reaction product of (meth)acrylic acid monomer containing hydroxyl group and polyisocyanate having at least one (meth)acryl group and at least one hydroxyl group in the molecule respectively, or polyol and poly Amide compounds containing isocyanate groups at the end obtained by isocyanate reaction, and amide reaction products of (meth)acrylic monomers having at least one (meth)acryl group and at least one hydroxyl group in the molecule, etc. .

The (meth)acrylic monomers containing hydroxyl used in the above-mentioned amine esterification reaction can be series such as (meth)acrylic monomers containing hydroxyl, and its specific examples include 2-hydroxyethyl (meth)acrylate, (meth) ) 2-hydroxypropyl acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glyceryl di(meth)acrylate, di(methyl) Trimethylolpropane Acrylate, Pentaerythritol Tri(meth)acrylate, Dipentamylthritol Penta(meth)acrylate. Specific examples other than hydroxyl-containing (meth)acrylic monomers include N-hydroxyalkyl (meth)acrylamide such as N-hydroxyethyl (meth)acrylamide, N-trimethylol (meth)acrylamide, etc. base) acrylamide monomer.

The polyisocyanates that can be used for the amine reaction with hydroxyl-containing (meth)acrylic monomers include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, Toluene diisocyanate, xylene diisocyanate, and diisocyanates obtained by hydrogenating aromatic isocyanates among these diisocyanates (for example, hydrogenated toluene diisocyanate, Hydrogenated xylene diisocyanate, etc.), di- or tri-isocyanates such as triphenylmethane triisocyanate, benzhydrylbenzene triisocyanate, and polyisocyanates obtained by multiplying the above-mentioned diisocyanates.

In addition, by reacting with polyisocyanate to form polyols for urethane compounds containing isocyanate groups at the end, in addition to aromatic, aliphatic or alicyclic polyols, polyester polyols and polyether polyols can also be used. Wait. Aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, and trimethylol Diethyl ethane, trimethylolpropane, ditrimethylolpropane, pentaerythritol, diisopentylthritol, ditrimethylol heptane, ditrimethylolpropionic acid, ditrimethylolbutane acid, glycerin, hydrogenated bisphenol A, etc.

Polyester polyols can be obtained by the dehydration condensation reaction of the above-mentioned polyols and polybasic carboxylic acids or their anhydrides. When "(anhydrous)" is added to the acid anhydride, examples of polybasic carboxylic acids or their anhydrides include (anhydrous) succinic acid, adipic acid, (anhydrous) maleic acid, (anhydrous) itaconic acid acid, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid, hexahydro (anhydrous) phthalic acid, etc.

In addition to polyalkylene glycols, polyester polyols include polyoxyalkylene-modified polyols obtained by reacting the above-mentioned polyols or dihydroxybenzenes with alkylene oxides.

The polyester (meth)acrylic oligomer refers to a compound having at least two (meth)acryl groups (typically (meth)acryloxy groups) in the molecule. Specifically, it can be obtained by dehydration condensation reaction using (meth)acrylic acid, polybasic carboxylic acid or its anhydride, and polyhydric alcohol. When "(anhydrous)" is added to the acid anhydride, examples of polybasic carboxylic acids or their anhydrides used in dehydration condensation reactions include (anhydrous) succinic acid, adipic acid, (anhydrous) maleic acid , (anhydrous) itaconic acid, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, hexahydro (anhydrous) phthalic acid, (anhydrous) phthalic acid, isophthalic acid, terephthalic acid formic acid etc. In addition, examples of polyhydric alcohols used in the dehydration condensation reaction include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, Glycol, Triethylene Glycol, Propylene Glycol, Neopentyl Glycol, Trimethylolethane, Trimethylolpropane, Ditrimethylolpropane, Pentaerythritol, Dipentyl Glycol, Ditrimethylolpropane Heptane, Ditrimethylolpropionic acid, Ditrimethylolbutyric acid, Glycerin, Hydrogenated Bisphenol A, etc.

The epoxy (meth)acrylic oligomer, which has at least two (meth)acryloxy groups in the molecule, can be obtained by, for example, additional reaction of polyglycidyl ether and (meth)acrylic acid. Examples of the polyglycidyl ether used in the additional reaction include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and bisphenol A diglycidyl ether. Glyceryl ether etc.

The polymerizable compound in the 2nd adhesive agent may consist only of a radically polymerizable compound, and may also contain the above-mentioned cationically polymerizable compound.

The second adhesive may be active energy ray curable or thermosetting, but active energy ray curable is preferable. When imparting active energy ray curability to the second adhesive, it is preferable to mix a photoradical polymerization initiator in the adhesive. The photoradical polymerization initiator is one that initiates a polymerization reaction of a radical hardening compound by irradiation of active energy rays such as visible rays, ultraviolet rays, X-rays, or electron beams. The photoradical polymerization initiator may be used alone or in combination of two or more.

Specific examples of photoradical polymerization initiators include acetophenone, 3-methylacetophenone, benzyl dimethyl ketal, 1-(4-isopropylphenyl)-2-hydroxy-2- Methylpropan-1-one, 2-methyl-1-[4-(methylthio)phenyl-2-morpholinopropan-1-one, 2-hydroxy-2-methyl-1-phenyl Acetophenone-based initiators such as propane-1-one; benzophenone-based initiators such as benzophenone, 4-chlorobenzophenone, and 4,4'-diaminobenzophenone; benzoin Benzoin ether-based initiators such as propyl ether and benzoin ethyl ether; thioxanthone-based initiators such as 4-isopropylthioxanthone; others include anthrone (or flavone), fluorenone, camphorquinone, benzaldehyde, anthracene quinones.

The compounded amount of the photoradical polymerization initiator is usually 0.5 to 20 parts by weight, preferably 1 to 6 parts by weight, relative to 100 parts by weight of the radically polymerizable compound. The radical polymerizable compound can be fully hardened by mix|blending 0.5 weight part or more of photoradical polymerization initiators.

(additive)

The first adhesive and/or the second adhesive may contain other additives as needed. Specific examples of additives include ion scavengers, antioxidants, chain transfer agents, polymerization accelerators (polyols, etc.), sensitizers, sensitization aids, light stabilizers, adhesives, thermoplastic resins, fillers, flow agents, etc. Regulator, plasticizer, defoamer, leveling agent, silane coupling agent, pigment, antistatic agent, ultraviolet absorber, thermal polymerization initiator. Moreover, a thermopolymerization initiator can be used instead of a photopolymerization initiator when preparing a thermosetting adhesive agent. Examples of ion scavengers include powdered bismuth-based, antimony-based, magnesium-based, aluminum-based, calcium-based, titanium-based, and mixtures of these inorganic compounds, and antioxidants include hindered phenolic antioxidants.

(Method of forming adhesive layer)

The first adhesive layer 150 may be directly formed on the surface of the polarizer 132 opposite to the side of the protective layer 131 . The first adhesive layer 150 can be formed by, for example, coating the first adhesive on the surface of the polarizer 132 or the surface of the base film to be peeled off in a subsequent step, or by dropping the first adhesive between the polarizer 132 and the base film. Adhesive, after laminating the polarizer 132 (or linear polarizer 130) and the base film through the layer before hardening of the first adhesive, for example, using an adhesive roller or the like to press from top to bottom to bond, then irradiating active energy rays It is cured (in the case of an active energy ray-curable adhesive) or heated and cured (in the case of a thermosetting adhesive). The active energy ray may be irradiated from the polarizing plate 130 side, or may be irradiated from the base film side.

The second adhesive layer 160 can be applied by applying the second adhesive on the surface of the first adhesive layer exposed by peeling off the base film used in the step of forming the first adhesive layer 150 , or on the surface of the phase difference body 140 . , or drop the second adhesive between the first adhesive layer 150 and the phase difference body 140, through the second The layer before curing of the adhesive layer laminates the linear polarizing plate 130 and the phase difference body 140, and after bonding them by pressing them from top to bottom with an adhesive roller, etc., they are cured by irradiating active energy rays (in the case of an active energy ray-curable adhesive) ), or heated to harden (in the case of thermosetting adhesives). Active energy rays may be irradiated from the side of the linear polarizer 130 or from the side of the phase difference body 140 .

Various coating methods such as a doctor blade, a wire bar, a die coater, a comma coater, and a gravure coater can be used for coating the adhesive agent. In addition, it is also possible to use the method of spreading the adhesive between the bonded layers.

As the irradiation conditions of active energy rays, any suitable conditions may be adopted as long as they are conditions capable of curing the above-mentioned active energy ray-curable adhesive. For example, the acceleration voltage for electron beam irradiation is preferably 5 kV to 300 kV, more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5kV, there may be a risk that the electron beam cannot reach the adhesive and the hardening is insufficient. If the acceleration voltage exceeds 300kV, the penetration force through the sample is too strong and the electron beam rebounds, and Risk of possible damage to film or polarizer. The radiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. If the irradiation dose is less than 5kGy, the adhesive will not harden enough. If it exceeds 100kGy, the retardation layer may be damaged, resulting in a decrease in mechanical strength or yellowing, and the desired optical properties cannot be obtained.

Electron beam irradiation is usually carried out in an inert gas, and it can also be carried out in the atmosphere or under the condition of introducing a small amount of oxygen if necessary.

In the ultraviolet curing type, the light irradiation intensity of the active energy ray curing adhesive is determined according to the composition of each adhesive, and is not particularly limited, but preferably 10 to 1,000 mJ/cm ² . If the intensity of light irradiated to the adhesive is less than 10mJ/ ^cm2 , the reaction time will be too long. If it exceeds 1,000mJ/ ^cm2 , it may be caused by the radiant heat from the light source and the polymerization of the adhesive. The exothermic heat will cause yellowing of the constituent materials of the adhesive. In addition, the irradiation intensity is preferably the intensity in the wavelength range of 400 nm or less, more preferably the intensity in the wavelength range of 280 to 320 nm. It is preferable to set the accumulated light amount to 10 mJ/cm ² or more, more preferably 100 to 1,000 mJ/cm ² by irradiating once or several times with such light irradiation intensity. If the cumulative light intensity on the above-mentioned adhesive agent is less than 10mJ/cm ² , the active species generated from the polymerization initiator will be insufficient, and the adhesive agent will not be sufficiently hardened. On the other hand, if the accumulated light amount exceeds 1,000 mJ/cm ² , the irradiation time will be very long, which is not conducive to improving the productivity. At this time, in which wavelength region (UVA (320 to 390nm) or UVB (280 to 320nm), etc.), the required integrated light quantity varies depending on the combination of the type of film or adhesive used.

In the present invention, the light source used for polymerization and hardening of the adhesive by irradiation of active energy rays is not particularly limited, and examples include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, xenon lamps, and halogen lamps. , carbon arc lamps, 鵭 lamps, gallium lamps, excimer lasers, LED light sources emitting light in the wavelength range of 380 to 440nm, chemical lamps, black light lamps, microwave excited mercury lamps, metal halide lamps. From the viewpoint of energy stability and simplicity of the device, an ultraviolet light source with a luminescence distribution below 420 nm in wavelength is preferable.

Even in the case of using an active energy ray-curable adhesive, heat treatment may be performed while irradiating active energy rays or after irradiating active energy rays. Before forming the coating layer of the adhesive, an easy-adhesive treatment such as saponification treatment, corona discharge treatment, plasma treatment, flame treatment, primer treatment, and anchor coating treatment may be applied to one or both sides of the adhesive surface.

[phase difference body]

The optical layered body 100 can function as a circular polarizer by including the linear polarizer 130 and the phase difference body 140 . Hereinafter, the configuration including the linear polarizer 130 and the phase difference body 140 is also referred to as a circular polarizer.

The phase difference body 140 preferably includes a first phase difference layer 141 and a second phase difference layer 142 . The first retardation layer 141 and the second retardation layer 142 are preferably bonded by an interlayer adhesive layer 143 described later. The first retardation layer 141 and the second retardation layer 142 may have an overcoat layer that protects their surfaces and a base film that supports the first retardation layer 141 . The first retardation layer 141 and the second retardation layer 142 include, for example, a retardation layer (λ/4 layer) that imparts a retardation of λ/4, a retardation layer (λ/4 layer) that imparts a retardation of λ/2 /2 layer) and positive C layer, etc.

The phase difference body 140 preferably contains a λ/4 layer, more preferably at least any one of a λ/4 layer and a λ/2 layer or a positive C layer.

In the phase difference body 140 , the first phase difference layer 141 and the second phase difference layer 142 are laminated in this order from the polarizer 132 side. When the retardation body 140 includes a λ/2 layer, the first retardation layer 141 is a λ/2 layer, and the second retardation layer 142 is a λ/4 layer. When the retardation body 140 contains a positive C layer, the first retardation layer 141 is a positive C layer, and the second retardation layer 142 is a λ/4 layer, or the first retardation layer 141 is a λ/4 layer, and the second The retardation layer 142 is a positive C layer. The thickness of the phase difference body 140 is, for example, 0.1 μm to 50 μm, preferably 0.5 μm to 30 μm, more preferably 1 μm to 10 μm.

The phase difference body 140 is preferably a cured product containing a polymerizable liquid crystal compound. In the case of such a configuration, it may be difficult to obtain adhesion with the polarizer 132 , but according to the present invention, high adhesion can be obtained. The first retardation layer 141 of the retardation body 140 is preferably a cured product containing a polymerizable liquid crystal compound. In the case of such a configuration, it may be difficult to obtain adhesion with the polarizer 132 , but according to the present invention, high adhesion can be obtained. The surface of the first retardation layer 141 facing the polarizer 132 may contain a polymerizable liquid crystal compound, or may contain a cured product of a radically polymerizable liquid crystal compound as a polymerizable liquid crystal compound. In the case of such a configuration, it may be difficult to obtain close contact with the polarizer 122 However, according to the present invention, high adhesion can be obtained. The surface of the first retardation layer 141 facing the polarizer 132 may be the surface of a layer showing a retardation, or may be an alignment film.

The second retardation layer 142 may be formed of the resin film exemplified as the material of the above-mentioned resin film, or may be formed of a layer cured by a polymerizable liquid crystal compound. The first retardation layer 141 and the second retardation layer 142 may further include an alignment film and a base film. The first retardation layer 141 having an alignment film and the second retardation layer 142 having an alignment film can be regarded as a single unit member.

In the case where the first retardation layer 141 and the second retardation layer 142 are formed from a layer formed by hardening a polymerizable liquid crystal compound, it is possible to apply a composition containing a polymerizable liquid crystal compound on the base film and harden it. And formed. The alignment film can be formed from a composition containing a polymerizable liquid crystal compound. The material and thickness of the base film may be the same as those of the aforementioned resin film. When the first retardation layer 141 and the second retardation layer 142 are formed of layers cured by a polymerizable liquid crystal compound, they can be incorporated into a laminate in the form of an alignment film and a base film.

The alignment film has an alignment control force to align the liquid crystal compound contained in the liquid crystal layer exhibiting phase difference formed on the alignment film in a desired direction. Examples of the alignment film include an alignment polymer film formed of an alignment polymer, a photo-alignment polymer film formed of a photo-alignment polymer, and a groove alignment film having a concave-convex pattern or multiple grooves on the film surface. The thickness of the alignment film is usually 0.01 to 10 μm, preferably 0.01 to 5 μm.

An alignment polymer film can be formed by coating a composition in which an alignment polymer has been dissolved in a solvent on a substrate film, removing the solvent, and performing leveling treatment if necessary. At this time, in the alignment polymer layer formed of the alignment polymer, the alignment control force can be adjusted arbitrarily according to the surface state or leveling condition of the alignment polymer.

A photoalignment polymer film can be formed by coating a composition containing a polymer or monomer with a photoreactive group and a solvent on a substrate film and irradiating polarized light. At this time, in the photo-alignment polymer film, the alignment control force can be adjusted arbitrarily according to the polarized light irradiation conditions etc. with respect to the photo-alignment polymer.

The groove alignment film can be formed by the following methods, for example: on the surface of the photosensitive polyimide film, the method of forming a concave-convex pattern by exposing and developing through an exposure mask with patterned slits; A method of forming an uncured film of active energy ray-curable resin on a plate-shaped master having grooves, transferring the film to a base film and curing it, and forming an uncured film of active energy ray-curable resin on a base film The hardened layer is formed by pressing a roll-shaped original disc with unevenness on the layer to form unevenness and harden it.

The liquid crystal layer expressing a retardation is one that imparts a retardation set by light, for example, a retardation expressing layer in a λ/2 layer, and a retardation expressing layer in a λ/4 layer.

A liquid crystal layer exhibiting phase difference can be formed using a known liquid crystal compound. The type of liquid crystal compound is not particularly limited, and rod-shaped liquid crystal compounds, discotic liquid crystal compounds, and mixtures thereof can be used. In addition, the liquid crystal compound may be a polymer liquid crystal compound, a polymerizable liquid crystal compound, or a mixture thereof. Examples of liquid crystal compounds include JP 11-513019, JP 2005-289980, JP 2007-108732, JP 2010-244038, JP 2010-31223 Gazette, JP 2010-270108, JP 2011-6360, JP 2011-207765, JP 2016-81035, International Publication 2017/043438 and JP 2011 - Liquid crystal compounds described in Publication No. 207765.

For example, when a polymerizable liquid crystal compound is used, a coating film is formed by coating a composition containing a polymerizable liquid crystal compound on an alignment film, and the film is cured to form a liquid crystal layer exhibiting phase difference. The thickness of the retardation layer is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 5 μm.

A composition containing a polymerizable liquid crystal compound may contain a polymerization initiator, a polymerizable monomer, a surfactant, a solvent, an adhesion improving agent, a plasticizer, an alignment agent, and the like in addition to the liquid crystal compound. The coating method of the composition containing a polymerizable liquid crystal compound includes known methods such as a die coating method. As a method for curing a composition containing a polymerizable liquid crystal compound, known methods such as irradiating active energy rays (for example, ultraviolet rays) can be mentioned.

The polarizing plate equipped with the polarizer 132 and the phase difference body 140 has an anti-reflection function as if the absorption axis of the polarizer 132 and the retardation axis of the phase difference body 140 form a set angle, that is, it functions as a circular polarizer. When the phase difference body 140 includes a λ/4 layer, the angle formed by the absorption axis of the polarizer 132 and the slow axis of the λ/4 layer may be 45°±10°. The first retardation layer 141 and the second retardation layer 142 may have positive wavelength dispersion or reverse wavelength dispersion. The λ/4 layer system preferably has reverse wavelength dispersion.

[Interlayer Adhesive Layer]

The interlayer adhesive layer 143 is disposed between the first retardation layer 141 and the second retardation layer 142 , and has the function of bonding the first retardation layer 141 and the second retardation layer 142 . The interlayer adhesive layer 143 may be composed of an adhesive or an adhesive. The interlayer adhesive layer 143 is preferably an adhesive layer.

The thickness of the interlayer adhesive layer 143 is not particularly limited. When an adhesive layer is used as the interlayer adhesive layer 143, it is preferably at least 1 μm, or at least 5 μm, usually less than 50 μm, or less than 25 μm. When an adhesive layer is used as the interlayer adhesive layer 143, the thickness of the interlayer adhesive layer 143 is preferably 0.1 μm or more, may be 0.5 μm or more, and is preferably 10 μm or less, or may be 5 μm or less.

The adhesive is, for example, one or a combination of two or more of water-based adhesives, active energy ray-curable adhesives, and the like. Water-based adhesives include, for example, polyvinyl alcohol-based resin aqueous solutions, water Sexual two-component urethane emulsion adhesive, etc. Active energy ray-curable adhesives are adhesives that are cured by irradiation with active energy rays. Examples include adhesives containing polymerizable compounds and photopolymerizable initiators, adhesives containing photoreactive resins, and adhesives containing adhesive resins. And photoreactive cross-linking agent adhesive, etc. Examples of the polymerizable compound include photopolymerizable monomers such as photocurable epoxy monomers, photocurable acrylic monomers, and photocurable urethane monomers, and oligomers derived from these monomers. Examples of the photopolymerization initiator include compounds containing substances that generate active species called neutral radicals, anion radicals, and cationic radicals by irradiation with active energy rays such as ultraviolet rays.

The adhesive can be composed of an adhesive composition that uses (meth)acrylic, rubber, urethane, ester, silicone, and polyvinyl ether resins as the base polymer. Among them, an adhesive composition in which a base polymer is made of a (meth)acrylic resin excellent in transparency, weather resistance, heat resistance, etc. is suitable. The adhesive composition may be an active energy ray curing type or a thermosetting type.

The (meth)acrylic resin (base polymer) used in the adhesive composition can be suitably used: for example, butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate A polymer or copolymer of one or more monomers of ester and 2-ethylhexyl (meth)acrylate. The base polymer is preferably a copolymerizable polar monomer. Examples of polar monomers include (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide N,N-dimethylamino ( A monomer having a carboxyl group, a hydroxyl group, an amido group, an amino group, an epoxy group, etc., such as ethyl meth)acrylate and glycidyl (meth)acrylate.

The adhesive composition may contain both a base polymer and a crosslinking agent. Examples of the crosslinking agent include metal ions with a valence of more than 2, which form a metal carboxylate salt with a carboxyl group, and form an amide bond with a carboxyl group; polyepoxides or polyols, which form an ester with a carboxyl group Bonds; polyisocyanate compounds, and form amide bonds with carboxyl groups. Among them, polyisocyanate compounds are preferred.

The active energy ray-curable adhesive composition refers to a property that can be cured by irradiation of active energy rays such as ultraviolet rays or electron beams, and can be adhered to an adherend such as a film with adhesiveness even before the irradiation of active energy rays Adhesive, an adhesive composition that can be hardened by irradiation with active energy rays to adjust the adhesiveness. The composition of the active energy ray curable adhesive is preferably an ultraviolet curable adhesive. The active energy ray-curable adhesive composition may further contain an active energy ray polymerizable compound in addition to the base polymer and the crosslinking agent. Moreover, a photopolymerization initiator, a photosensitizer, etc. may be contained as needed.

The adhesive composition may contain light diffusing agents, resins other than the base polymer, adhesives, fillers (metal powder or other inorganic powders, etc.), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, and defoamers , anti-corrosion agent, photopolymerization initiator and other additives.

<Manufacturing method of optical layered body>

The method for producing the optical layered body is not particularly limited. One type has the following steps: coating the first adhesive on the surface of the polarizer, hardening the first adhesive to form a first adhesive layer, and making the layer formed on the polarizer through the second adhesive. The step of forming the first adhesive layer and the retardation bulk layer on the surface, and hardening the second adhesive to form the second adhesive layer.

<Image display device>

An image display device includes an image display panel and the above-mentioned optical layered body. In an image display device, the optical layered body may be arranged, for example, on the front surface of an image display panel. The image display panel is not particularly limited, and examples thereof include liquid crystal display panels, organic electroluminescence (organic EL) display panels, inorganic electroluminescence (inorganic EL) display panels, plasma display panels, and electric field emission display panels. Wait. An image display device can be constituted by disposing an optical laminate functioning as a circular polarizing plate on the viewing side of an organic EL display device.

The image display device of the present invention can be used as mobile devices such as smartphones and tablet computers, televisions, digital photo frames, electronic signboards (kanbans), measuring instruments or measuring instruments, office equipment, medical equipment, computer equipment, and the like. The image display device of the present invention is excellent in durability even when used in a harsh environment.

[Example]

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited to the scope of these examples. In the following examples, the following are used as a radical polymerizable compound, a photoradical polymerization initiator, a cation polymerizable compound, a photocationic polymerization initiator, and an additive constituting an adhesive.

(radical polymerizable compound)

[1] Radical polymerizable compound 1: 1,4-cyclohexanedimethanol monoacrylate (trade name "CHDMMA" available from Nippon Chemical Co., Ltd.)

[2] Radical polymerizable compound 2: 4-hydroxybutyl acrylate (purchased from Nippon Chemical Co., Ltd. under the trade name "4HBA")

[3] Radical polymerizable compound 3: 2-functional amine ester acrylate (trade name "UV-3700B" from Mitsubishi Chemical Co., Ltd.)

(photoradical polymerization initiator)

[4] Photoradical polymerization initiator 1: 1-hydroxycyclohexyl phenyl ketone (trade name "Omnirad 184" from BASF Corporation)

[5] Photoradical polymerization initiator 2: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (trade name "TPO" from BASF Corporation)

(Cationically polymerizable compound)

[6] Cationic polymerizable compound 1: 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate (trade name "CEL2021P" available from Daicel Co., Ltd.)

[7] Cationic polymerizable compound 2: 1,2-epoxy-4-(2-oxiranyl)cyclohexane addition of 2,2-bis(hydroxymethyl)-1-butanol (obtained Product name "EHPE3150" from Daicel Co., Ltd.)

[8] Cationic polymerizable compound 3: 3-ethyl-3-{[(3-ethyloxiran-3-yl)methoxy]methyl}oxirane (from Toagosei Co., Ltd. ) product name "OXT-221")

(Photocationic polymerization initiator)

[9] Photocationic polymerization initiator 1: Triarylsulfonium salt (trade name "CPI-100P" from Sun Appro Co., Ltd., 50% by weight propylene carbonate solution)

(additive)

[10] Photosensitizer 1: 1,4-diethoxynaphthalene (trade name "Anthracure-ET2201" available from Kawasaki Chemical Industry Co., Ltd.)

[11] Photosensitizer 2: 9,10-dibutoxyanthracene (trade name "Anthracure-UVS-1331" available from Kawasaki Chemical Industry Co., Ltd.)

<Manufacturing Example 1: Preparation of Radical Polymerizable Adhesive>

Measure the following radical polymerizable compounds and photoradical polymerization initiators in the following proportions into a 20mL spiral tube, mix, defoam, and prepare hardened liquid free radicals by ultraviolet irradiation polymeric adhesive. Hereinafter, this adhesive agent is also called "adhesive agent R".

<Manufacturing Example 2: Preparation of Cationic Polymer Adhesive>

Measure the following cationic polymerizable compounds, photocationic polymerization initiators, and additives into a 20mL spiral tube in the following proportions, mix, defoam, and prepare a hardened liquid cationic by ultraviolet irradiation polymeric adhesive. Hereinafter, this adhesive agent is also called "adhesive agent C1".

<Manufacturing Example 3: Preparation of Cationic Polymer Adhesive>

Measure the following cationic polymerizable compounds, photocationic polymerization initiators, and additives into a 20mL spiral tube in the following proportions, mix, defoam, and prepare a hardened liquid cationic by ultraviolet irradiation polymeric adhesive. Hereinafter, this adhesive agent is also referred to as "adhesive agent C2".

光增敏劑2 2質量份。

Photosensitizer 2 2 parts by mass.

<Preparation of Adhesive Layer>

Commercially available Adhesive Layer 1 with Separation Membrane (layer made of acrylic adhesive, thickness 15 μm) and Adhesive Layer 2 with separation membrane (layer made of acrylic adhesive, thickness 5 μm) were prepared. .

<Example 1: Production of an optical laminate>

The multi-layered film was laminated and bonded to a polyvinyl alcohol (PVA) resin film (polarizer, thickness 8 μm) obtained by dyeing iodine and stretched to produce a linear polarizing plate. Adhere the cyclic olefin polymer (COP) film (thickness 24 μm) with the hard coat (HC) and the polarizer water paste, and dry it to obtain the polarizer (polarizer) with the protective layer. The hard coat (HC) ) is a hard coat protected by a protective film made of polyethylene terephthalate (PET). Corona treatment is performed on the surface where the polarizer is exposed, and a biaxially stretched COP film (thickness 52 μm) is bonded to the surface through an ultraviolet curable adhesive (adhesive C1), and UVA is output at 200mJ/cm ² , from The side of the biaxially stretched COP film is irradiated with ultraviolet (UV) light. After aging at room temperature for one night, the biaxially stretched COP film was peeled off. In this way, a linear polarizing plate is obtained in which the surface of the polarizing plate is provided with the first adhesive layer of the hardened layer of the adhesive C1. In addition, a retardation body (integrated body laminated with a reverse dispersion λ/4 retardation layer/positive C layer/protective film (PET)) was prepared, and the linear polarizer and the retardation body were bonded together using an adhesive R. Specifically, corona treatment is performed on the exposed surface of the first adhesive layer and the exposed surface of the reverse dispersive λ/4 retardation layer, and the two are laminated through an ultraviolet curable adhesive (adhesive R), and UV light was irradiated from the phase difference body side with a UVA intensity of 200 mJ/cm ² to bond the linear polarizing plate and the phase difference body. Thus, an optical laminate is obtained, which is the second adhesive layer through the hardened layer of the adhesive R between the reverse dispersion λ/4 retardation layer and the first adhesive layer (hardened layer of the adhesive C1) bring the two into contact. Then, the protective film (PET) of the phase difference body in the optical laminate was peeled off, and after corona treatment was performed on the exposed surface of the positive C layer, the adhesive layer 1 with the separation film was adhered. The optical layered body of Example 1 was obtained by the above operation. In the optical laminate system of Example 1, the hardened layer of the adhesive C1 (the first adhesive layer) and the hardened layer of the adhesive R (the second adhesive layer) are interposed between the polarizer and the reverse dispersion λ/4 retardation layer. ) to form.

<Comparative example 1: Production of optical laminate>

The optical laminate of Comparative Example 1 was produced in the same manner as in Example 1, except that the formation of the first adhesive layer was not carried out, and that Adhesive C2 was used instead of Adhesive R for bonding between the linear polarizing plate and the retarder. body. The formation of the hardened layer of the adhesive C2, specifically, corona treatment is carried out on the exposed surface of the polarizer and the reverse dispersion λ/4 retardation layer, and the two are laminated through the adhesive C2, and then 200mJ/ The UVA intensity of cm ² is irradiated with UV light from the phase difference body side to bond the linear polarizer and the phase difference body. The optical laminate system of Comparative Example 1 is formed between the polarizer and the reverse dispersion λ/4 retardation layer via a hardened layer of adhesive C2.

<Comparative example 2: Production of optical laminate>

Except that the formation of the first adhesive layer was not carried out, and the adhesive layer 2 was used instead of the adhesive agent R for bonding between the linear polarizing plate and the phase difference body, the same method as that of Example 1 was used to produce a film of Comparative Example 2. Optical laminates. By bonding the adhesive layer 2, specifically, corona treatment is performed on the exposed surface of the polarizer and the reverse dispersion λ/4 retardation layer, and the two are laminated through the adhesive layer 2. The optical laminate system of Comparative Example 2 is formed between the polarizer and the reverse dispersion λ/4 retardation layer via an adhesive layer 2 .

<Measurement of tensile modulus>

Adhesive C1, Adhesive C2, and Adhesive R were respectively used to coat the adhesive on a biaxially stretched COP film (thickness 52 μm), and irradiated with UV light at a UVA intensity of 200 mJ/ ^cm2 to form an average film thickness after curing of 0.3μm adhesive layer. Using an autoclave (manufactured by Shimadzu Corporation, product name: AG-IS) at a temperature of 25°C, each adhesive layer and the adhesive layer 2 with a film thickness of 5 μm were uniaxially stretched at a rate of 1 mm/min. The tensile modulus of elasticity was calculated from the value of the stress-strain curve obtained. Table 1 shows the tensile modulus of each layer at a temperature of 25°C.

[Table 1]

<Durability test (high temperature and high humidity conditions, high temperature conditions)>

Each optical layered body of Example 1, Comparative Example 1, and Comparative Example 2 was cut into a size of 30 mm × 30 mm, and the separation film attached to the adhesive layer 1 was peeled off, and bonded to an alkali-free glass made by Corning (Corning) (trade name: Eagle XG, 40 mm x 40 mm, thickness 0.7 mm), a sample that was autoclaved at a temperature of 50° C. was prepared. Each test sample was placed in an autoclave set under high-temperature and high-humidity conditions (temperature 80° C., relative humidity 90% RH) for 24 hours. Use a spectrophotometer (V-7100 manufactured by JASCO) to measure the degree of polarization (Py1) at a wavelength of 550 nm before putting into the autoclave and the degree of polarization (Py2) at a wavelength of 550 nm after being placed in the autoclave for 24 hours, according to the following The formula calculates the △Py of the change.

△Py=Py2-Py1

In addition, the reflection hue (a1*, b1*) before putting the test sample into the autoclave and measuring the reflection hue (a1*, b1*) before putting it into the autoclave and using a portable spectrophotometer (manufactured by Konica Minolta, product name: CM-2600d) on a metal reflector plate were measured. The reflection hue (a2*, b2*) after standing for 24 hours. Δc* of the amount of change was calculated according to the following formula.

△c*=√{(a2*-a1*) ² +(b2*-b1*) ² }

Place each sample in an autoclave set under high temperature conditions (temperature 105°C, relative humidity 0%RH) for 30 minutes, and calculate △c* in the same way as the above high temperature and high humidity conditions.

Table 2 shows the calculated values of ΔPy and Δc*.

<Adhesion test>

Each optical layered body of Example 1, Comparative Example 1, and Comparative Example 2 was cut into a size of 30 mm × 30 mm, and the separation film attached to the adhesive layer 1 was peeled off, and bonded to an alkali-free glass made by Corning (Corning) (trade name: Eagle XG, 40 mm x 40 mm, thickness 0.7 mm), a sample that was autoclaved at a temperature of 50° C. was prepared. After peeling off the HC-attached COP film on the outermost surface of each sample, cut a cross with a dicing knife at 1 mm intervals in the range of 10 mm x 10 mm to make 10 x 10 (100) squares. Stick Nichiban Cellophane Tape (registered trademark) on all the squares so that it is fully adhered, and then peel off at one go at an angle of 45 degrees obliquely upward. This operation measures the number of squares remaining on the glass side. Table 2 shows the number of residual squares.

[Table 2]

100: Optical laminate

130: linear polarizer

131: protective layer

132: Polarizer

140:Phase difference body

141: The first retardation layer

142: The second retardation layer

143: interlayer adhesive layer

150: 1st adhesive layer

160: The second adhesive layer

Claims (8)

An optical laminate comprising a polarizer containing a polyvinyl alcohol-based resin and a phase difference body containing a cured product of a polymerizable liquid crystal compound, wherein, Between the polarizer and the retarder, there are a first adhesive layer provided in contact with the polarizer and a second adhesive layer provided in contact with the retarder. The optical laminated body according to claim 1, wherein, The tensile elastic modulus of the first adhesive layer at a temperature of 25°C is 2,000 MPa or more, The tensile elastic modulus of the second adhesive layer at a temperature of 25° C. is 1,900 MPa or less. The optical laminate according to claim 1 or 2, wherein, The first adhesive layer is a hardened layer of a cationic polymerizable adhesive, The second adhesive layer is a hardened layer of a radically polymerizable adhesive. The optical laminate according to any one of claims 1 to 3, wherein the phase difference body includes a λ/4 layer. The optical laminate according to any one of Claims 1 to 4 is a polarizing plate for antireflection. An image display device comprising an image display panel and the optical laminate according to claim 5 arranged in front of the image display panel. The image display device according to claim 6, wherein, The aforementioned image display panel is an organic EL display panel. A method for manufacturing an optical laminate is the method for manufacturing an optical laminate described in any one of Claims 1 to 5, which has a step of applying a first adhesive on the surface of the polarizer, and curing the first adhesive to form a first adhesive layer, and A step of forming the first adhesive layer and the retardation bulk layer formed on the surface of the polarizer through a second adhesive, and curing the second adhesive to form the second adhesive layer.

Images