KR20210130171A - laminate - Google Patents

Abstract

An object of this invention is to provide the laminated body excellent in adhesive force by suppressing generation|occurrence|production of a bubble even when it bends repeatedly with the front plate side turned outward. The present invention includes a front plate, a first pressure-sensitive adhesive layer formed using the first pressure-sensitive adhesive composition, a polarizer layer, a second pressure-sensitive adhesive layer formed using the second pressure-sensitive adhesive composition, and a rear panel in this order, When the shear modulus at a temperature of 25° C. of the first pressure-sensitive adhesive layer is G1 [Pa], and the shear modulus at a temperature of 25° C. of the second pressure-sensitive adhesive layer is G2 [Pa], the following relational expression (1): G1≥G2　 ( 1) is satisfied, and the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer have a gel fraction of 45% or more and 85% or less.

Description

laminate

The present invention relates to a laminate.

Japanese Patent Application Laid-Open No. 2018-28573 (Patent Document 1) describes a laminate for a flexible image display device having a plurality of pressure-sensitive adhesive layers.

Japanese Patent Laid-Open No. 2018-28573

With respect to the display device including the laminated body which has a front plate and several adhesive layers, when the front plate side was turned outward and it bent repeatedly, there existed a case where the bubble generate|occur|produced in the adhesive layer in a laminated body. Moreover, the adhesive force of an adhesive layer was weak, and floatation and peeling may arise between an adhesive layer and a to-be-adhered member.

It is an object of the present invention to provide a laminate having excellent adhesion and suppressing the generation of air bubbles even when repeatedly bent with the front plate side facing outward.

MEANS TO SOLVE THE PROBLEM This invention provides the following laminated bodies, an adhesive composition, and an adhesive sheet.

[1] 　 A front plate, a first pressure-sensitive adhesive layer formed using the first pressure-sensitive adhesive composition, a polarizer layer, a second pressure-sensitive adhesive layer formed using the second pressure-sensitive adhesive composition, and a back plate in this order,

When the shear modulus at a temperature of 25° C. of the first pressure-sensitive adhesive layer is G1 [Pa], and the shear modulus at a temperature of 25° C. of the second pressure-sensitive adhesive layer is G2 [Pa], the following relational formula (1):

G1≥G2　　(1)

to satisfy,

The said 1st adhesive layer and the said 2nd adhesive layer are a laminated body whose gel fraction is 45% or more and 85% or less.

[2] 　 The first pressure-sensitive adhesive composition and the second pressure-sensitive adhesive composition both contain a (meth)acrylic polymer,

The laminate according to [1], wherein the (meth)acrylic polymer contains less than 5% by mass based on the total mass of the structural unit derived from the monomer having a reactive functional group.

[3] 　 The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer both contain a (meth)acrylic polymer,

The laminate according to [1] or [2], wherein the (meth)acrylic polymer has a weight average molecular weight (Mw) of 200,000 or more and 1.5 million or less.

[4] The laminate according to any one of [1] to [3], wherein the back plate is a touch sensor panel.

[5] A display device comprising the laminate according to any one of [1] to [4].

[6] 　 The display device according to [6], wherein the front plate side is bent to the outside.

ADVANTAGE OF THE INVENTION According to this invention, generation|occurrence|production of a bubble is suppressed and it can provide the laminated body excellent in adhesive force even when it bends repeatedly with the front plate side turned outward.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows an example of the laminated body which concerns on this invention.
2 is a schematic cross-sectional view showing an example of a laminate according to the present invention.
3 is a schematic diagram illustrating a method of a flexibility test.
It is sectional drawing which shows typically the manufacturing method of the laminated body of this invention.

Hereinafter, a laminate (hereinafter, simply referred to as a “laminate”) according to an aspect of the present invention will be described with reference to the drawings.

<Laminate>

1 shows a schematic cross-sectional view of a laminate according to an aspect of the present invention. The laminate 100 includes a front plate 101 , a first adhesive layer 102 , a polarizer layer 103 , a second adhesive layer 104 , and a back plate 105 in this order. . The first pressure-sensitive adhesive layer 102 is formed of a first pressure-sensitive adhesive composition, and the second pressure-sensitive adhesive layer 104 is formed of a second pressure-sensitive adhesive composition. Hereinafter, the 1st adhesive layer 102 and the 2nd adhesive layer 104 may be collectively called an adhesive layer.

The thickness of the laminate 100 is not particularly limited because it varies depending on the functions required for the laminate and the use of the laminate, but for example, 50 µm or more and 4,000 µm or less, preferably 100 µm or more and 2000 µm or less. , more preferably 150 µm or more and 1000 µm or less.

The planar view shape of the laminate 100 may be, for example, a rectangular shape, preferably a rectangular shape having a long side and a short side, and more preferably a rectangular shape. When the shape of the surface direction of the laminated body 100 is a rectangle, the length of the long side may be 10 mm or more and 1400 mm or less, for example, Preferably they are 50 mm or more and 600 mm or less. The length of the short side is, for example, 5 mm or more and 800 mm or less, preferably 30 mm or more and 500 mm or less, and more preferably 50 mm or more and 300 mm or less. As for each layer which comprises a laminated body, the corner part may be R-processed, the edge part may be notched, or the punching process may be carried out.

The laminate 100 can be used, for example, in a display device or the like. The display device is not particularly limited, and examples thereof include an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, and an electroluminescence display device. The display device may have a touch panel function.

[Physical properties of the adhesive layer]

In the laminate 100, the shear modulus of the first pressure-sensitive adhesive layer 102 at a temperature of 25° C. is G1 [Pa], and the shear modulus of the second pressure-sensitive adhesive layer 104 at a temperature of 25° C. is G2 [Pa]. , the following relation (1):

G1≥G2　　　(1)

, and more preferably the following relation (1'):

G1>G2　　　(1')

satisfy the As for whether the relation (1) or (1') is satisfied,

i) a method of judging based on each value of G1 and G2;

ii) There is a method of judging based on other combinations that are large and small, such as the combination of G1 and G2.

For other combinations of ii), for example, when the first pressure-sensitive adhesive layer 102 and the second pressure-sensitive adhesive layer 104 have the same thickness, the first standard pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer formed of the first pressure-sensitive adhesive composition It can be determined by comparing the second reference pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition. As long as the first reference pressure-sensitive adhesive layer and the second reference pressure-sensitive adhesive layer have the same thickness, the shear modulus G ₀ 1 [Pa] at a temperature of 25° C. of the first reference pressure-sensitive adhesive layer and the second reference pressure-sensitive adhesive layer at a temperature of 25° C. The shear modulus G ₀ 2 [Pa] of is, the following relation (1a):

G ₀ 1≥G ₀ 2 (1a)

If , it can be considered that the relation (1) is satisfied, and the following relation (1'a):

G ₀ 1>G ₀ 2 (1'a)

If , it can be considered that the relation (1') is satisfied. _{The shear modulus G 0} 1 and G ₀ 2 of the first reference pressure-sensitive adhesive layer having a thickness of 150 μm and the second reference pressure-sensitive adhesive layer at a temperature of 25° C. are measured according to the measurement method described in the column of Examples to be described later.

The first adhesive layer 102 and the second adhesive layer 104 have a gel fraction of 45% or more and 85% or less, and preferably 50% or more and 80% or less. The gel fraction of the 1st adhesive layer 102 and the 2nd adhesive layer 104 is measured according to the measuring method described in the column of the Example mentioned later.

The laminate 100 can be bent with the front plate 101 side facing outward. With respect to a display device including a laminate, when the front plate side is turned outward and bent repeatedly, bubbles may be generated in the pressure-sensitive adhesive layer. Generation|occurrence|production of such a bubble is especially remarkable in the 2nd adhesive layer 104 in the adhesive layer far from the front plate side, ie, the laminated body 100 . As a result of research by the present inventors, the shear modulus of the first pressure-sensitive adhesive layer 102 and the second pressure-sensitive adhesive layer 104 satisfies the relational formula (1), and when the respective gel fractions are 45% or more and 85% or less, the entire surface Even if it made the board 101 side outward and it bent repeatedly, it discovered that the bubble which generate|occur|produced in the adhesive layer in the laminated body 100 could be suppressed. More specifically, even if it bends repeatedly 20,000 times so that the radius of curvature of the inner surface of the laminate 100 is 3 mm, bubbles generated in the pressure-sensitive adhesive layer in the laminate 100 can be suppressed (hereinafter referred to as “excellent “room temperature flexibility”). ') was found. Normal temperature flexibility can be evaluated according to the evaluation method described in the column of the Example mentioned later. The laminate 100 may be bent with the front plate side inside. The display device to which the laminate 100 is applied can be used as a flexible display that can be bent or wound. In this specification, the bending|flexion includes the form of bending in which a curved surface is formed in a bending part, and the bending radius of the bending inner surface is not specifically limited. Further, the bending includes refraction in which the refraction angle of the inner surface is greater than 0 degrees and less than 180 degrees, and folding in which the bending radius of the inner surface is close to zero or the refraction angle of the inner surface is 0 degrees.

The shear modulus of the first reference adhesive layer having a thickness of 150 μm at a temperature of 25° C. is G ₀ 1 [Pa], and the shear modulus at a temperature of 25° C. of the second reference pressure-sensitive adhesive layer having a thickness of 150 μm is G ₀ 2 [Pa]. Preferably, the following relations (2) and (3):

1.0×10 ⁴ ≤G ₀ 1≤5.0×10 ⁵ (2)

1.0×10 ⁴ ≤G ₀ 2≤5.0×10 ⁵ (3)

, and more preferably the following relations (2a) and (3a):

2.0×10 ⁴ ≤G ₀ 1≤2.0×10 ⁵ (2a)

2.0×10 ⁴ ≤G ₀ 2≤2.0×10 ⁵ (3a)

, and more preferably the following relations (2b) and (3b):

3.0×10 ⁴ ≤G ₀ 1≤1.0×10 ⁵ (2b)

2.0×10 ⁴ ≤G ₀ 2≤7.0×10 ⁴ (3b)

satisfy the

The first pressure-sensitive adhesive composition and the second pressure-sensitive adhesive composition so that the shear modulus of the first pressure-sensitive adhesive layer 102 and the second pressure-sensitive adhesive layer 104 satisfies the relational formula (1), and each gel fraction is 45% or more and 85% or less. As a method of preparing, for example, the pressure-sensitive adhesive layer is composed of the pressure-sensitive adhesive composition A to be described later, or the type of monomer constituting the (meth)acrylic polymer A to be described later is changed, or the molecular weight of the (meth)acrylic polymer A is adjusted, or , the method of containing the compound which has an acetoacetoxyethyl group, etc. are mentioned.

[Adhesive composition]

The 1st adhesive layer 102 and the 2nd adhesive layer 104 are formed from the adhesive composition (henceforth adhesive composition A) containing a (meth)acrylic-type polymer in one aspect. The adhesive composition A may be an active energy ray hardening type or a thermosetting type. In addition, in this specification, "(meth)acrylic-type polymer" shows at least 1 sort(s) chosen from the group which consists of an acryl-type polymer and a methacryl-type polymer. The same applies to other terms appended with "(meta)". About a 1st adhesive composition and a 2nd adhesive composition, when all contain a (meth)acrylic-type polymer, the (meth)acrylic-type polymer may be the same or different. Hereinafter, the (meth)acrylic-type polymer contained in the adhesive composition A is also called (meth)acrylic-type polymer A.

The (meth)acrylic polymer A preferably has a weight average molecular weight (Mw) of 200,000 or more and 1.5 million or less, from the viewpoint of easily satisfying the relational expression (2) or the relational expression (3) with respect to the pressure-sensitive adhesive layer obtained, and 300,000 It is more preferable that it is more than 1.2 million.

As for the (meth)acrylic polymer A, the structural unit derived from the monomer which has a reactive functional group, Preferably, it is less than 5 mass % based on the total mass of a polymer. As the reactive functional group, for example, a hydroxyl group, a carboxy group, an amino group, an amide group, and an epoxy group. Thereby, the flexibility of the pressure-sensitive adhesive layer is improved and the generation of bubbles in the pressure-sensitive adhesive layer tends to be easily suppressed. The (meth)acrylic polymer A has a structural unit derived from a monomer having a reactive functional group, from the viewpoint of suppressing bubbles during bending, more preferably 0.01% by mass or less based on the total mass of the polymer, more preferably reactive It does not have a structural unit derived from the monomer which has a functional group, More preferably, it does not have a hydroxyl group, a carboxy group, an amino group, an amide group, and an epoxy group.

(1) Active energy ray-curable pressure-sensitive adhesive composition

When the pressure-sensitive adhesive composition A is an active energy ray-curable pressure-sensitive adhesive composition, the (meth)acrylic polymer A contained in the pressure-sensitive adhesive composition A is a (meth)acrylic monomer having a linear or branched alkyl group having 1 to 24 carbon atoms. It may contain constituent units derived from it. As a (meth)acrylic-type monomer which has a linear or branched C1-C24 alkyl group, (meth)acrylic acid alkylester etc. may be sufficient, for example, As the example, (meth)acrylate butyl, (meth)acrylic acid Methyl, (meth)ethyl acrylate, (meth)acrylic acid hexyl, (meth)acrylic acid octyl, (meth)acrylic acid lauryl, (meth)acrylic acid isooctyl, (meth)acrylic acid isodecyl, (meth)acrylic acid 2-ethylhexyl, (meth)acrylic acid isobornyl, etc. are mentioned. The (meth)acrylic-type polymer A may be a polymer or copolymer which uses 1 type(s) or 2 or more types of the said (meth)acrylic-acid alkylester as a monomer. Content of the (meth)acrylic-type polymer A in the adhesive composition A may be 50 mass % or more and 100 mass % or less with respect to 100 mass parts of solid content of the adhesive composition A, for example, Preferably it is 80 mass % or more and 99.5 mass % or less. , More preferably, they are 90 mass % or more and 99 mass % or less.

The weight average molecular weights (Mw) of the (meth)acrylic polymer A may be, for example, 200,000 or more and 800,000 or less, and preferably 300,000 or more and 700,000 or less from the viewpoint of suppression of bubbles at the time of bending. A weight average molecular weight (Mw) can be measured according to the measuring method demonstrated in the column of the Example mentioned later.

The adhesive composition A may contain the (meth)acrylic-type polymer A 1 type, or 2 or more types. In addition, the adhesive composition A may contain only the (meth)acrylic-type polymer A as the structural component, and may contain a crosslinking agent further. Examples of the crosslinking agent include those that form a metal carboxylate salt between a carboxyl group and a divalent or higher metal ion; A polyamine compound that forms an amide bond with a carboxy group; A polyepoxy compound or polyol that forms an ester bond with a carboxy group; As a polyisocyanate compound, what forms an amide bond between a carboxy group, etc. are mentioned. Especially, a polyisocyanate compound is preferable. When the adhesive composition A contains a crosslinking agent, content of a crosslinking agent may be 5 mass parts or less with respect to 100 mass parts of (meth)acrylic-type polymer A, Preferably, 1 mass part or less, More preferably, 0.5 It is a mass part or less, More preferably, it is 0.1 mass part or less, It is most preferable that the adhesive composition A does not contain a crosslinking agent.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by irradiation with active energy rays such as ultraviolet rays or electron beams, has adhesiveness even before irradiation with active energy rays, and can adhere to an adherend such as a film, and is irradiated with active energy rays It is a pressure-sensitive adhesive composition having a property that can be cured by curing, such as adhesion.

It is preferable that an active energy ray hardening-type adhesive composition is an ultraviolet curable type.

When the pressure-sensitive adhesive composition A is an active energy ray-curable pressure-sensitive adhesive composition, the pressure-sensitive adhesive composition A may further contain an active energy ray polymerizable compound, a photoinitiator, a photosensitizer, and the like.

As an active energy ray-polymerizable compound, For example, (meth)acrylate monomer which has at least 1 piece(s) acryloyloxy group in a molecule|numerator; (meth)acrylic compounds such as (meth)acryloyloxy group-containing compounds such as (meth)acrylate oligomers which can be obtained by reacting two or more functional group-containing compounds and have at least two (meth)acryloyloxy groups in the molecule compounds can be mentioned. The adhesive composition A can contain 0.1 mass part or more and 10 mass parts or less of an active energy ray polymeric compound with respect to 100 mass parts of solid content of the adhesive composition A.

As a photoinitiator, diphenyl (2,4,6- trimethylbenzoyl) phosphine oxide, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone etc. are mentioned, for example. When the pressure-sensitive adhesive composition A includes a photopolymerization initiator, it may include one type or two or more types. When the adhesive composition A contains a photoinitiator, 0.01 mass part or more and 1.0 mass part or less may be sufficient as the total content with respect to 100 mass parts of solid content of the adhesive composition A, for example.

It is preferable that the adhesive composition A contains the compound which has an acetoacetoxyethyl group.

It is preferable that at least one of a 1st adhesive composition and a 2nd adhesive composition is adhesive composition A containing the compound which has an acetoacetoxyethyl group. With the pressure-sensitive adhesive composition A containing a compound having an acetoacetoxyethyl group, the first reference pressure-sensitive adhesive layer and the second reference pressure-sensitive adhesive layer satisfying the above-described relational formulas (2) and (3) can be easily formed. Moreover, with the adhesive composition A containing the compound which has an acetoacetoxyethyl group, the adhesive layer whose gel fractions are 45 % or more and 85 % or less can be formed easily. The pressure-sensitive adhesive composition A contains the compound having an acetoacetoxyethyl group in 100 parts by mass of the solid content of the pressure-sensitive adhesive composition A, for example, 0.01 parts by mass or more and 20 parts by mass or less, preferably 0.1 parts by mass or more and 10 parts by mass or less, more preferably It may contain 0.1 parts by mass or more and 8 parts by mass or less.

Although the compound which has an acetoacetoxyethyl group is not specifically limited, The compound shown by a following formula is illustrated.

In the formula, R ₁ is hydrogen or a methyl group.

The pressure-sensitive adhesive composition A includes fine particles for imparting light scattering properties, beads (resin beads, glass beads, etc.), glass fibers, resins other than the base polymer, tackifiers, fillers (metal powders and other inorganic powders, etc.), antioxidants, It may contain additives such as ultraviolet absorbers, dyes, pigments, colorants, defoamers, and corrosion inhibitors. It is preferable that the adhesive composition A does not contain an organic solvent from a viewpoint of preventing the durability fall by a residual solvent.

When the pressure-sensitive adhesive layer is formed of the pressure-sensitive adhesive composition A, the pressure-sensitive adhesive layer can be formed by applying the pressure-sensitive adhesive composition A on a substrate. When an active energy ray hardening-type adhesive composition is used, it can be set as the hardened|cured material which has a desired degree of hardening by irradiating an active energy ray to the formed adhesive layer.

(2) thermosetting pressure-sensitive adhesive composition

When the pressure-sensitive adhesive composition A is a thermosetting pressure-sensitive adhesive composition, the (meth)acrylic polymer A is a monomer unit constituting the polymer, and (meth)acrylic acid alkylester having 2 to 20 carbon atoms in the alkyl group, and a reactive functional group in the molecule It is preferable to contain a monomer (reactive functional group containing monomer).

The (meth)acrylic-type polymer A can express preferable adhesiveness by containing the C2-C20 (meth)acrylic-acid alkylester of an alkyl group as a monomer unit which comprises the said polymer. As the (meth)acrylic acid alkylester having 2 to 20 carbon atoms in the alkyl group, the homopolymer having a glass transition temperature (Tg) of -40°C or less (hereinafter referred to as “low Tg alkyl acrylate” may be used). desirable. By containing such a low Tg alkyl acrylate as a structural monomer unit, the softness|flexibility of an adhesive layer improves and it exists in the tendency which becomes easy to suppress the bubble generation at the time of bending|flexion.

Examples of the low-Tg alkyl acrylate include n-butyl acrylate (Tg-55° C.), n-octyl acrylate (Tg-65° C.), isooctyl acrylate (Tg-58° C.), and 2-ethylhexyl acrylate (Tg). -70°C), isononyl acrylate (Tg-58°C), isodecyl acrylate (Tg-60°C), isodecyl methacrylate (Tg-41°C), n-lauryl methacrylate (Tg-65°C) ), tridecyl acrylate (Tg-55° C.), tridecyl methacrylate (-40° C.), and the like. Among them, from the viewpoint of easily satisfying the relational expression (2) or the relational expression (3) with respect to the obtained pressure-sensitive adhesive layer, as the low Tg alkyl acrylate, it is more preferable that the Tg of the homopolymer is -45° C. or less, and -50 It is especially preferable that it is below °C. Specifically, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferable. These may be used independently and may be used in combination of 2 or more type.

(meth)acrylic polymer A, as a monomer unit constituting the polymer, preferably contains 85% by mass or more of low Tg alkyl acrylate as a lower limit, more preferably 90% by mass or more, and 95% by mass or more It is more preferable to contain more.

It will become easy to satisfy relational expression (2) or relational expression (3) with respect to the adhesive layer obtained as it is such a range.

In addition, as for the (meth)acrylic polymer A, it is preferable to contain 99.9 mass % or less as an upper limit of the said low Tg alkyl acrylate as a monomer unit which comprises the said polymer, It is more preferable to contain 99.5 mass % or less, 99 It is more preferable to contain not more than mass %. By containing the said low Tg alkyl acrylate 99.9 mass % or less, another monomer component (particularly a reactive functional group containing monomer) can be introduce|transduced in the (meth)acrylic-type polymer A in a suitable quantity.

The (meth)acrylic polymer A has a glass transition temperature (Tg) as a homopolymer of 0° C. in order to easily set the glass transition temperature (Tg) of the main polymer of the pressure-sensitive adhesive according to the present embodiment to the above-mentioned range. It is preferable to make content of the monomer (Hereinafter, it may call a "hard monomer") in excess of this as small as possible. Specifically, (meth)acrylic polymer A is a monomer unit constituting the polymer, and the content of the hard monomer as an upper limit is preferably 15% by mass or less, more preferably 10% by mass or less, It is more preferable to set it as 5 mass % or less. In addition, the reactive functional group containing monomer mentioned later is also contained in this hard monomer.

Examples of the hard monomer include methyl acrylate (Tg10°C), methyl methacrylate (Tg105°C), ethyl methacrylate (Tg65°C), n-butyl methacrylate (Tg20°C), isobutyl methacrylate (Tg48°C), t-butyl methacrylate (Tg107°C), acrylic acid n-stearyl (Tg30°C), methacrylic acid n-stearyl (Tg38°C), cyclohexyl acrylate (Tg15°C), cyclomethacrylate Hexyl (Tg66°C), phenoxyethyl acrylate (Tg5°C), phenoxyethyl methacrylate (Tg54°C), benzyl methacrylate (Tg54°C), isobornyl acrylate (Tg94°C), isobornyl methacrylate (Tg180℃), acryloylmorpholine (Tg145℃), adamantyl acrylate (Tg115℃), adamantyl methacrylate (Tg141℃), acrylic acid (Tg103℃), dimethyl acrylamide (Tg89℃), acrylamide Acrylic monomers, such as (Tg165 degreeC), vinyl acetate (Tg32 degreeC), styrene (Tg80 degreeC), etc. are mentioned.

(meth)acrylic polymer A, by containing a reactive functional group-containing monomer as a monomer unit constituting the polymer, through a reactive functional group derived from the reactive functional group-containing monomer, reacts with a thermal crosslinking agent to be described later, and thereby a crosslinked structure ( A three-dimensional network structure) is formed, and an adhesive having a desired cohesive force can be obtained.

The (meth)acrylic polymer A is a monomer unit constituting the polymer, and as a reactive functional group-containing monomer, a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer having a carboxy group in the molecule (carboxy group-containing monomer), molecule A monomer (amino group-containing monomer) etc. which have an amino group in it are mentioned preferably. Among these, since there are many things whose glass transition temperature (Tg) is 0 degrees C or less, a hydroxyl-containing monomer is especially preferable.

As the hydroxyl group-containing monomer, for example, (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 3-hydroxypropyl, (meth)acrylic acid 2-hydroxybutyl, ( (meth)acrylic acid hydroxyalkyl esters, such as meth)acrylic-acid 3-hydroxybutyl and (meth)acrylic-acid 4-hydroxybutyl, etc. are mentioned. Among them, 2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate, from the viewpoint of the glass transition temperature (Tg), the reactivity of the hydroxyl group with the thermal crosslinking agent in the obtained (meth)acrylic polymer A, and copolymerizability with other monomers. It is preferably at least one of hydroxypropyl, 3-hydroxypropyl acrylate, and 4-hydroxybutyl acrylate. These may be used independently and may be used in combination of 2 or more type.

Examples of the carboxyl group-containing monomer include ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid. These may be used independently and may be used in combination of 2 or more type.

Examples of the amino group-containing monomer include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate. These may be used independently and may be used in combination of 2 or more type.

It is preferable that the (meth)acrylic polymer A contains 0.1 mass % or more as a lower limit of a reactive functional group containing monomer as a monomer unit which comprises the said polymer, It is especially preferable to contain 0.5 mass % or more, Furthermore, it is 1 mass % It is preferable to contain more than that. Moreover, it is preferable to contain 10 mass % or less as an upper limit, It is preferable to contain especially 8 mass % or less, Furthermore, it is preferable to contain less than 5 mass %. When the (meth)acrylic polymer A contains a reactive functional group-containing monomer, particularly a hydroxyl group-containing monomer, in the above amount as a monomer unit, it is easy to satisfy the relational expression (2) or the relational expression (3) with respect to the pressure-sensitive adhesive layer obtained.

The (meth)acrylic polymer A does not need to contain a carboxyl group-containing monomer, particularly acrylic acid which is also a hard monomer, as a monomer unit constituting the polymer. Since a carboxyl group is an acid component, by not containing a carboxyl group-containing monomer, a problem arises in the affixing object of an adhesive by an acid, For example, transparent conductive films, such as tin-doped indium oxide (ITO), Even when a metal film, a metal mesh, etc. exist, such problems (corrosion, resistance value change, etc.) caused by acid can be suppressed.

The (meth)acrylic polymer A may contain another monomer as a monomer unit which comprises the said polymer as needed. As another monomer, even in order not to interfere with the action of a reactive functional group containing monomer, the monomer which does not contain the functional group which has reactivity is preferable. As such other monomers, for example, (meth)acrylic acid alkoxyalkyl esters such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate, the glass transition temperature (Tg) as a homopolymer is more than -40°C; A monomer (hereinafter, sometimes referred to as "medium Tg alkyl acrylate") etc. which is 0 degreeC or less is mentioned. As the heavy Tg alkyl acrylate, for example, ethyl acrylate (Tg-20°C), isobutyl acrylate (Tg-26°C), 2-ethylhexyl methacrylate (Tg-10°C), n-lauryl acrylate ( Tg-23 degreeC), isostearyl acrylate (Tg-18 degreeC), etc. are mentioned. These may be used independently and may be used in combination of 2 or more type.

A random copolymer may be sufficient as the polymerization aspect of the (meth)acrylic-type polymer A, and a block copolymer may be sufficient as it.

The lower limit of the weight average molecular weight of the (meth)acrylic polymer A is preferably 200,000 or more, particularly preferably 300,000 or more, and further preferably 400,000 or more. Problems, such as leaching of an adhesive, that the lower limit of the weight average molecular weight of (meth)acrylic-type polymer A is more than the said is suppressed. In addition, the weight average molecular weight in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.

Moreover, it is preferable that it is 1.5 million or less, and, as for the upper limit of the weight average molecular weight of the (meth)acrylic-type polymer A, it is especially preferable that it is 1.35 million or less, Furthermore, it is preferable that it is 1.2 million or less. The upper limit of the weight average molecular weight of a (meth)acrylic acid ester polymer (A) becomes it easy to satisfy relational expression (2) or relational expression (3) with respect to the adhesive layer obtained as it is below the said.

In addition, in the adhesive composition A, the (meth)acrylic-type polymer A may be used individually by 1 type, and may be used in combination of 2 or more type.

When the pressure-sensitive adhesive composition A containing the thermal crosslinking agent is heated, the thermal crosslinking agent crosslinks the (meth)acrylic polymer A to form a three-dimensional network structure. Thereby, while the cohesive force of the adhesive obtained improves, it becomes easy to satisfy relational expression (2) or relational expression (3) with respect to the adhesive layer obtained.

The thermal crosslinking agent may be one that reacts with the reactive group of the (meth)acrylic polymer A, for example, an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an amine-based crosslinking agent, a melamine-based crosslinking agent, an aziridine-based crosslinking agent, a hydrazine-based crosslinking agent, and an aldehyde-based crosslinking agent. A crosslinking agent, an oxazoline type crosslinking agent, a metal alkoxide type crosslinking agent, a metal chelate type crosslinking agent, a metal salt type crosslinking agent, an ammonium salt type crosslinking agent, etc. are mentioned. Among the above, when the reactive group which the (meth)acrylic polymer A has is a hydroxyl group, it is preferable to use the isocyanate type crosslinking agent excellent in reactivity with a hydroxyl group. In addition, a thermal crosslinking agent can be used individually by 1 type or in combination of 2 or more type.

An isocyanate type crosslinking agent contains a polyisocyanate compound at least.

As a polyisocyanate compound, For example, aromatic polyisocyanate, such as tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, aliphatic polyisocyanate, such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethanedi Alicyclic polyisocyanates, such as isocyanate, and their biuret form, isocyanurate form, furthermore, a reaction product with a low-molecular active hydrogen-containing compound such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. A duct body etc. are mentioned. Among them, trimethylolpropane-modified aromatic polyisocyanates, particularly trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate, are preferable from the viewpoint of reactivity with hydroxyl groups.

Examples of the epoxy-based crosslinking agent include 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylylenediamine, Ethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidyl aniline, diglycidylamine, etc. are mentioned.

It is preferable that content of the thermal crosslinking agent in the adhesive composition A is 0.01 mass % or more with respect to 100 mass % of (meth)acrylic-type polymer A, It is more preferable that it is 0.05 mass % or more, It is more preferable that it is 0.1 mass % or more. Moreover, it is preferable that the said content is 1 mass % or less, It is more preferable that it is 0.8 mass % or less, It is more preferable that it is 0.5 mass % or less. When content of a thermal crosslinking agent exists in an above-mentioned range, it becomes easy to satisfy relational expression (2) or relational expression (3) with respect to the adhesive layer obtained.

It is preferable that the adhesive composition A contains an above-described silane coupling agent. The adhesive layer obtained by this improves adhesiveness with each member in the flexible laminated body used as a to-be-adhered body, and becomes the thing excellent in durability with respect to a bending|flexion.

As a silane coupling agent, it is an organosilicon compound which has at least one alkoxysilyl group in a molecule|numerator, Compatibility with the (meth)acrylic-type polymer A is good, and what has light transmittance is preferable.

Examples of the silane coupling agent include: polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethoxysilane; 3-glycidoxypropyltrimethoxysilane; Silicon compounds having an epoxy structure such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyl Melcapto group-containing silicon compounds such as dimethoxymethylsilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3- An amino group-containing silicon compound such as aminopropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, or at least one of these and methyltriethoxysilane, ethyltriethoxysilane, methyl Condensates with alkyl group containing silicon compounds, such as trimethoxysilane and ethyl trimethoxysilane, etc. are mentioned. These may be used individually by 1 type, and may be used in combination of 2 or more type.

It is preferable that content of the silane coupling agent in the adhesive composition A is 0.01 mass % or more with respect to 100 mass % of (meth)acrylic-type polymer A, It is more preferable that it is 0.05 mass % or more, It is more preferable that it is 0.1 mass % or more . Moreover, it is preferable that the said content is 1 mass % or less, It is more preferable that it is 0.5 mass % or less, It is more preferable that it is 0.3 mass % or less. When content of a silane coupling agent exists in said range, the adhesive layer obtained becomes a more preferable adhesiveness with each member in the flexible laminated body used as a to-be-adhered body.

The various additives mentioned above can be added to adhesive composition A as needed. In addition, a polymerization solvent and a dilution solvent shall not be contained in the additive which comprises the adhesive composition A.

The (meth)acrylic polymer A can be manufactured by superposing|polymerizing the mixture of the monomer which comprises a polymer by a normal radical polymerization method. The polymerization of the (meth)acrylic polymer A is preferably performed according to a solution polymerization method using a polymerization initiator as desired. As a polymerization solvent, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone etc. are mentioned, for example, You may use 2 or more types together.

As a polymerization initiator, an azo compound, an organic peroxide, etc. are mentioned, You may use 2 or more types together. As the azo compound, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane 1-carbononi) Tril), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'- Azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-hydroxymethylpropionitrile), 2,2'- azobis[2-(2-imidazolin-2-yl)propane] etc. are mentioned.

Examples of the organic peroxide include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, and di(2-ethoxyethyl)peroxydicarbonate. , t-butylperoxyneodecanoate, t-butylperoxypivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionylperoxide, diacetyl peroxide, and the like.

On the other hand, in the said polymerization process, the weight average molecular weight of the polymer obtained can be adjusted by mix|blending chain transfer agents, such as 2-mercaptoethanol.

When the (meth)acrylic polymer A is obtained, a thermal crosslinking agent, a silane coupling agent, and optionally an additive and a diluent solvent are added to the solution of the (meth)acrylic polymer A, and the adhesive composition A ( application solution) is obtained.

On the other hand, in any of the above components, when using a solid one, or when precipitation occurs when mixed with other components in an undiluted state, the component is dissolved or diluted in a diluting solvent in advance alone, and then , and may be mixed with other components.

Examples of the diluent solvent include aliphatic hydrocarbons such as hexane, heptane and cyclohexane, aromatic hydrocarbons such as toluene and xylene, halogenated hydrocarbons such as methylene chloride and ethylene chloride, methanol, ethanol, propanol, butanol, 1-methyl Alcohols such as toxy-2-propanol, ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone and cyclohexanone, esters such as ethyl acetate and butyl acetate, cellosolve solvents such as ethyl cellosolve, etc. this is used

The concentration and viscosity of the coating solution prepared in this way may be within a range that can be coated, and is not particularly limited, and may be appropriately selected depending on the situation. For example, it dilutes so that the density|concentration of the adhesive composition A may be 10-60 mass %. On the other hand, when obtaining a coating solution, addition of a diluent solvent etc. is not a necessary condition, and if it is a viscosity etc. which can be coated with the adhesive composition A, it is not necessary to add a dilution solvent. In this case, the adhesive composition A turns into a coating solution which uses the polymerization solvent of the (meth)acrylic-type polymer A as a dilution solvent as it is.

The adhesive preferable as an adhesive which concerns on this embodiment bridge|crosslinks the adhesive composition A, and is formed. The pressure-sensitive adhesive composition A can be crosslinked by heat treatment. In addition, this heat processing can also serve as a drying process at the time of volatilizing a dilution solvent etc. from the coating film of the adhesive composition A apply|coated to the desired object.

It is preferable that it is 50-150 degreeC, and, as for the heating temperature of heat processing, it is more preferable that it is 70-120 degreeC. Moreover, it is preferable that they are 10 second - 10 minutes, and, as for heating time, it is more preferable that they are 50 seconds - 2 minutes.

After the heat treatment, if necessary, a curing period of about 1 to 2 weeks may be provided at normal temperature (eg, 23°C, 50%RH). When this curing period is required, an adhesive is formed after completion|finish of heat processing, when a curing period is unnecessary after a curing period elapses.

By the above-described heat treatment (and curing), the (meth)acrylic polymer A is sufficiently crosslinked via a crosslinking agent to form a crosslinked structure, and an adhesive is obtained. Such an adhesive becomes easy to satisfy relational expression (2) or relational expression (3) with respect to the adhesive layer obtained.

The pressure-sensitive adhesive sheet according to the present invention includes a pressure-sensitive adhesive layer formed of the above-described pressure-sensitive adhesive composition A according to the present invention. An adhesive layer can be formed by apply|coating adhesive composition A on a base material. When a thermosetting adhesive composition is used as adhesive composition A, it can be set as the hardened|cured material which has a desired degree of hardening by heat-processing (and curing) to the formed adhesive layer. In addition, about the conditions of heat processing and curing, it is as above-mentioned.

The release film to which the release process was given may be sufficient as a base material. An adhesive sheet can be produced by forming the layer which consists of an adhesive on a release film in sheet form, and bonding another peeling film on the adhesive layer.

As a method of applying the coating liquid of the pressure-sensitive adhesive composition A, for example, a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method, a gravure coating method, etc. can be used.

The adhesive composition A can be manufactured by a well-known method by collectively mixing each component using a mixer etc., for example.

[Front panel]

The front plate 101 is not limited in material and thickness as long as it is a plate-like body capable of transmitting light, and may be composed of only one layer or may be composed of two or more layers. As the example, a resin plate-shaped object (for example, a resin plate, a resin sheet, a resin film, etc.), a glass-made plate-shaped object (for example, a glass plate, a glass film, etc.), and the touch sensor panel mentioned later are mentioned. The front plate may constitute the outermost surface of the display device.

The thickness of the front plate 101 may be, for example, 10 µm or more and 500 µm or less, preferably 30 µm or more and 200 µm or less, and more preferably 50 µm or more and 100 µm or less. In this invention, the thickness of each layer can be measured according to the thickness measuring method demonstrated in the Example mentioned later.

When the front plate 101 is a plate-shaped body made of resin, the plate-shaped body made of resin is not limited as long as it can transmit light. Examples of the resin constituting the resin-made plate-like body such as a resin film include triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, Polystyrene, polyamide, polyetherimide, poly(meth)acrylic, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal , polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, a film formed of a polymer such as polyamideimide. . These polymer|macromolecules can be used individually or in mixture of 2 or more types. From the viewpoint of improving strength and transparency, it is preferably a resin film formed of a polymer such as polyimide, polyamide, or polyamideimide.

The front plate 101 is a film in which the hard-coat layer is preferably provided in at least one surface of a base film from a viewpoint of raising hardness. As a base film, the film which consists of the said resin can be used. The hard-coat layer may be formed in one surface of a base film, and may be formed in both surfaces. By providing a hard-coat layer, it can be set as the resin film which improved hardness and scratch property. The hard coat layer is, for example, a cured layer of ultraviolet curable resin. Examples of the ultraviolet curable resin include acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. The hard-coat layer may contain the additive in order to improve hardness. The additive is not limited, and inorganic fine particles, organic fine particles, or a mixture thereof may be mentioned.

When the front plate 101 is a glass plate, the tempered glass for a display is used preferably as a glass plate. The thickness of a glass plate may be 10 micrometers or more and 1,000 micrometers or less, for example. By using a glass plate, the front plate 101 which has excellent mechanical strength and surface hardness can be comprised.

When the laminate 100 is used in a display device, the front plate 101 not only has a function (function as a window film) to protect the front surface (screen) of the display device, but also functions as a touch sensor, blue light cut What has a function, a viewing angle adjustment function, etc. may be sufficient.

[First Adhesive Layer]

The first pressure-sensitive adhesive layer 102 is a layer that is interposed between the front plate 101 and the polarizer layer 103 and bonds them together. A layer may be formed. The first pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer disposed at a position closest to the front plate among the pressure-sensitive adhesive layers constituting the laminate. An adhesive is also called a pressure-sensitive adhesive. As used herein, the term "adhesive" refers to an adhesive other than an adhesive (pressure-sensitive adhesive), and is clearly distinguished from an adhesive. Although the 1st adhesive layer 102 may consist of one layer or may consist of two or more layers, Preferably it is one layer.

The first pressure-sensitive adhesive layer 20 may be formed using a pressure-sensitive adhesive composition directly or by using a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed using the pressure-sensitive adhesive composition. The pressure-sensitive adhesive composition can be formed from the pressure-sensitive adhesive composition A as described above.

It is preferable that the thickness of the 1st adhesive layer 102 is 3 micrometers or more and 100 micrometers or less, for example, It is more preferable that they are 5 micrometers or more and 50 micrometers or less, 20 micrometers or more may be sufficient.

[Polarizer layer]

As the polarizer layer 103, the stretched film or stretched layer to which the dichroic dye was made to adsorb|suck, the layer etc. which apply|coat and harden the composition containing a dichroic dye and a polymeric compound are mentioned. As a dichroic dye, iodine and a dichroic organic dye are specifically used. In the dichroic organic dye, C.I. The dichroic direct dye which consists of disazo compounds, such as DIRECT RED 39, and the dichroic direct dye which consists of compounds, such as trisazo and tetrakis azo, is contained.

As a polarizer layer formed by coating and curing a composition containing a dichroic dye and a polymerizable compound, a composition containing a dichroic dye having liquid crystallinity or a composition containing a dichroic dye and a polymerizable liquid crystal is coated and cured. The polarizer layer containing hardened|cured material of polymerizable liquid crystal compounds, such as a layer, is mentioned.

The polarizer layer formed by apply|coating and hardening the composition containing a dichroic dye and a polymeric compound is preferable since there is no restriction|limiting in a bending direction compared with the stretched film or stretched layer to which the dichroic dye was adsorbed.

[Stretched film or stretched layer, a polarizer layer]

The polarizer layer, which is a stretched film to which a dichroic dye is adsorbed, is usually a step of uniaxially stretching a polyvinyl alcohol-based resin film, dyeing a polyvinyl alcohol-based resin film with a dichroic dye, a step of adsorbing the dichroic dye, It can manufacture through the process of treating the polyvinyl alcohol-type resin film to which the dichroic dye has adsorbed with the aqueous boric acid solution, and the process of washing with water after the process with the aqueous boric acid solution.

The thickness of the polarizer layer 103 is 2 micrometers or more and 40 micrometers or less, for example. The thickness of the polarizer layer 103 may be 5 µm or more, 20 µm or less, 15 µm or less, and further 10 µm or less.

Polyvinyl alcohol-type resin can be obtained by saponifying polyvinyl acetate-type resin. As polyvinyl acetate-type resin, the copolymer of vinyl acetate and other monomer copolymerizable to it other than polyvinyl acetate which is a homopolymer of vinyl acetate is used. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having an ammonium group.

The saponification degree of polyvinyl alcohol-type resin is about 85 mol% or more and 100 mol% or less normally, Preferably it is 98 mol% or more. The polyvinyl alcohol-type resin may be modified|denatured, for example, polyvinyl formal and polyvinyl acetal modified|denatured with aldehydes can also be used. The polymerization degree of polyvinyl alcohol-type resin is 1,000 or more and 10,000 or less normally, Preferably they are 1,500 or more and 5,000 or less.

The polarizer layer, which is a stretched layer to which the dichroic dye is adsorbed, is usually a process of applying a coating liquid containing the polyvinyl alcohol-based resin on a base film, a process of uniaxially stretching the obtained laminated film, a uniaxially stretched laminated film By dyeing the polyvinyl alcohol-based resin layer with a dichroic dye, the dichroic dye is adsorbed to form a polarizer layer; It can be manufactured through the following process.

You may peel and remove a base film from a polarizer layer as needed. The material and thickness of a base film may be the same as that of the thermoplastic resin film mentioned later and thickness.

The polarizer layer which is a stretched film or a stretched layer may be knitted into the laminated body in the form by which the thermoplastic resin film is pasted together on the single side|surface or both surfaces. This thermoplastic resin film can function as a protective film for the polarizer layer 103 or retardation film. A thermoplastic resin film, For example, Polyolefin resins, such as chain|strand polyolefin resin (polypropylene resin etc.) and cyclic polyolefin resin (norbornene type resin etc.); Cellulose resins, such as a triacetyl cellulose; polyester-based resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; polycarbonate-based resin; (meth)acrylic resin; Or it may be a film made of a mixture thereof or the like.

The thickness of the thermoplastic resin film is usually 300 µm or less, preferably 200 µm or less, more preferably 100 µm or less, still more preferably 80 µm or less, and still more preferably 60 µm or less from the viewpoint of reducing the thickness of the thermoplastic resin film. It is micrometer or less, and is 5 micrometers or more normally, Preferably it is 20 micrometers or more.

The thermoplastic resin film may or may not have retardation.

A thermoplastic resin film can be bonded to the polarizer layer 103 using an adhesive bond layer, for example.

[A polarizer layer formed by applying and curing a composition containing a dichroic dye and a polymerizable compound]

As a polarizer layer formed by coating and curing a composition containing a dichroic dye and a polymerizable compound, a composition containing a polymerizable dichroic dye having liquid crystallinity or a composition containing a dichroic dye and a polymerizable liquid crystal is applied to a base film The polarizer layer containing hardened|cured material of polymeric liquid crystal compounds, such as a layer obtained by apply|coating and hardening, is mentioned.

You may peel and remove a base film from a polarizer layer as needed. The material and thickness of the base film may be the same as the material and thickness of the above-described thermoplastic resin film. The polarizer layer may be provided with an orientation film. The alignment film may be peeled off.

The polarizer layer formed by apply|coating and hardening the composition containing a dichroic dye and a polymeric compound may be knitted together in the optical laminated body in the form by which the thermoplastic resin film is bonded by the single side|surface or both surfaces. As a thermoplastic resin film, the thing similar to the thermoplastic resin film which can be used for a polarizer layer which is a stretched film or a stretched layer can be used. A thermoplastic resin film can be bonded to a polarizer layer using an adhesive bond layer, for example.

As for the polarizer layer formed by apply|coating and hardening the composition containing a dichroic dye and a polymeric compound, the overcoat (OC) layer may be formed as a protective layer on the single side|surface or both surfaces. A photocurable resin, a water-soluble polymer, etc. are mentioned. As a photocurable resin, (meth)acrylic-type resin, a urethane-type resin, (meth)acrylic-urethane-type resin, an epoxy resin, silicone resin etc. are mentioned, for example. As a water-soluble polymer, For example, a poly(meth)acrylamide type polymer; polyvinyl alcohol and vinyl alcohol-based polymers such as ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, (meth)acrylic acid or its anhydride-vinyl alcohol copolymer; carboxyvinyl-based polymers; polyvinylpyrrolidone; starch; sodium alginate; Polyethylene oxide-type polymer etc. are mentioned. The thickness of the OC layer is preferably 20 µm or less, more preferably 15 µm or less, still more preferably 10 µm or less, and may be 5 µm or less, and may be 0.05 µm or more and 0.5 µm or more.

The thickness of the polarizer layer formed by apply|coating and hardening the composition containing a dichroic dye and a polymeric compound is 10 micrometers or less normally, Preferably they are 0.5 micrometer or more and 8 micrometers or less, More preferably, they are 1 micrometer or more and 5 micrometers or less. am.

[Second adhesive layer]

The second adhesive layer 104 is an adhesive layer disposed between the polarizer layer 103 and the back plate 105 . The second pressure-sensitive adhesive layer may be a pressure-sensitive adhesive layer disposed at a position closest to the back plate among the pressure-sensitive adhesive layers constituting the laminate. The number of the 2nd adhesive layers 104 may be one, or although what consists of two or more layers may be sufficient, Preferably it is one layer.

The composition and compounding components of the pressure-sensitive adhesive composition constituting the second pressure-sensitive adhesive layer 104, the type of the pressure-sensitive adhesive composition (whether active energy ray curing type or thermosetting type, etc.), additives that can be formulated in the pressure-sensitive adhesive composition, the second pressure sensitive adhesive layer About a manufacturing method and the thickness of a 2nd adhesive layer, it is as having shown in description of the 1st adhesive layer 102 mentioned above.

The second pressure-sensitive adhesive layer 104 may be the same as or different from the first pressure-sensitive adhesive layer 102 in the composition, compounding component, thickness, and the like of the pressure-sensitive adhesive composition.

[Backboard]

As the back plate 105, a plate-like body capable of transmitting light, a component used in a normal display device, or the like can be used.

The thickness of the rear plate 105 may be, for example, 5 µm or more and 2,000 µm or less, preferably 10 µm or more and 1,000 µm or less, and more preferably 15 µm or more and 500 µm or less.

As a plate-shaped object used for the back plate 105, it may be comprised with only one layer, it may be comprised with two or more layers, and what was illustrated about the plate-shaped object described in the front plate 101 can be used.

As a component used for the normal display apparatus used for the back plate 105, a separator, a touch sensor panel, organic electroluminescent display element etc. are mentioned, for example. In the order of lamination of the components in the display device, for example, front plate/circularly polarizing plate/separator, front plate/circularly polarizing plate/organic EL display element, front plate/circularly polarizing plate/touch sensor panel/organic EL display element, front surface Plate/touch sensor panel/circularly polarizing plate/organic EL display element etc. are mentioned.

(touch sensor panel)

As the touch sensor panel, as long as it is a sensor capable of detecting the touched position, the detection method is not limited, and a touch sensor panel such as a resistive film method, a capacitive coupling method, an optical sensor method, an ultrasonic method, an electromagnetic inductive coupling method, or a surface acoustic wave method This is exemplified. Since it is low cost, the touch sensor panel of a resistive film type and a capacitive coupling type is used suitably.

An example of a resistive touch sensor panel includes a pair of substrates disposed opposite to each other, an insulating spacer sandwiched between the pair of substrates, a transparent conductive film provided as a resistive film on the entire inner surface of each substrate, and a touch position It is constituted by a detection circuit. In an image display device provided with a resistive touch sensor panel, when the surface of the front plate is touched, the opposing resistive film is short-circuited, and a current flows through the resistive film. The touch position detection circuit detects a change in voltage at this time, and the touched position is detected.

An example of the touch sensor panel of the capacitive coupling method is comprised by the board|substrate, the transparent electrode for position detection provided on the front surface of the board|substrate, and a touch position detection circuit. In an image display device provided with a capacitive coupling type touch sensor panel, when the surface of the front plate is touched, the transparent electrode is grounded through the human body's capacitance at the touched point. The touch position detection circuit detects the grounding of the transparent electrode, and the touched position is detected.

The thickness of the touch sensor panel may be, for example, 5 µm or more and 2,000 µm or less, or 5 µm or more and 100 µm or less.

[phase difference layer]

The laminate 100 may further include one or two or more retardation layers. The retardation layer is usually disposed between the polarizer layer 103 and the rear plate 105 . The retardation layer is the first adhesive layer 102, the second adhesive layer 104, or another layer (the other retardation layer included) can be stacked on

[bonding layer]

A bonding layer is a layer arrange|positioned between the 1st adhesive layer 102 and the 2nd adhesive layer 104, and is a layer comprised from an adhesive or an adhesive agent. The pressure-sensitive adhesive constituting the bonding layer may be the same as that exemplified for the pressure-sensitive adhesive composition constituting the first pressure-sensitive adhesive layer 102 or the second pressure-sensitive adhesive layer, and other pressure-sensitive adhesives such as (meth)acrylic pressure-sensitive adhesives and styrene pressure-sensitive adhesives , a silicone pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a polyester pressure-sensitive adhesive, an epoxy-based copolymer pressure-sensitive adhesive, or the like.

As an adhesive agent which comprises a bonding layer, it can form combining 1 or 2 or more types among a water-system adhesive agent, an active energy ray hardening-type adhesive agent, an adhesive, etc., for example. Examples of the water-based adhesive include a polyvinyl alcohol-based resin aqueous solution, a water-based two-part type urethane-based emulsion adhesive, and the like. The active energy ray-curable adhesive is an adhesive that is cured by irradiating active energy rays such as ultraviolet rays, for example, a polymerizable compound and a photopolymerizable initiator, a photoreactive resin, a binder resin, and a photoreactive crosslinking agent and those containing As said polymerizable compound, photopolymerizable monomers, such as a photocurable epoxy type monomer, a photocurable acrylic type monomer, and a photocurable urethane type monomer, the oligomer derived from these monomers, etc. are mentioned. As said photoinitiator, the thing containing the substance which irradiates active energy rays, such as an ultraviolet-ray, to generate|occur|produce active species, such as a neutral radical, an anion radical, and a cationic radical, is mentioned.

The thickness of the bonding layer may be, for example, 1 µm or more, preferably 1 µm or more and 25 µm or less, more preferably 2 µm or more and 15 µm or less, and still more preferably 2.5 µm or more and 5 µm or less.

The laminated body 200 shown in FIG. 2 is equipped with the front plate 101, the 1st adhesive layer 102, the polarizer layer 103, the pasting layer 108, and the back plate 105, The 1st retardation layer (106), the bonding layer 109, the 2nd retardation layer 107, and the 2nd adhesive layer 104 are further provided.

Examples of the retardation layer include a positive A plate such as a λ/4 plate and a λ/2 plate, a positive C plate, and the like.

The retardation layer may be, for example, a retardation film that can be formed from the above-mentioned thermoplastic resin film, or may be a layer formed by curing a polymerizable liquid crystal compound, that is, a layer containing a cured product of the polymerizable liquid crystal compound, but preferably is the latter.

The thickness of the retardation film may be the same as the thickness of the above-mentioned thermoplastic resin film. The thickness of the retardation layer formed by curing the polymerizable liquid crystal compound is, for example, 0.1 µm or more and 10 µm or less, preferably 0.5 µm or more and 8 µm or less, and more preferably 1 µm or more and 6 µm or less.

The retardation layer formed by hardening|curing a polymeric liquid crystal compound can be formed by apply|coating and hardening a composition containing a polymeric liquid crystal compound to a base film. An orientation layer may be formed between a base film and an application layer. The material and thickness of the base film may be the same as the material and thickness of the above-described thermoplastic resin film.

The retardation layer formed by hardening|curing a polymeric liquid crystal compound may be knitted together by the laminated body 100 in the form which has an orientation layer and/or a base film. The back plate 105 may be a base film to which the composition is applied.

As described above, the bonding layer 108 may use an adhesive or an adhesive. The above-mentioned adhesive composition A may be sufficient as this adhesive.

As the adhesive, a water-based adhesive or an active energy ray-curable adhesive can be used. Examples of the water-based adhesive include an adhesive composed of a polyvinyl alcohol-based resin aqueous solution, and a water-based two-part type urethane-based emulsion adhesive.

The active energy ray-curable adhesive refers to an adhesive that is cured by irradiating active energy rays such as ultraviolet rays, for example, a polymerizable compound and a photopolymerization initiator, a photoreactive resin, a binder resin, and a photoreactivity The thing containing a crosslinking agent, etc. are mentioned.

Examples of the polymerizable compound include photopolymerizable monomers such as photocurable epoxy monomers, photocurable (meth)acrylic monomers, and photocurable urethane monomers, and oligomers derived from photopolymerizable monomers.

As a photoinitiator, the thing containing the substance which generate|occur|produces active species, such as a neutral radical, an anion radical, and a cationic radical, by irradiation of active energy rays, such as an ultraviolet-ray, is mentioned. As an active energy ray-curable adhesive agent containing a polymerizable compound and a photoinitiator, the thing containing a photocurable epoxy-type monomer and a photocationic polymerization initiator can be used preferably.

[Method for producing a laminate]

The laminated body 100 can be manufactured according to the method including the process of bonding the layers which comprise the laminated body 100 through an adhesive layer or an adhesive bond layer further. When bonding layers through an adhesive layer or an adhesive bond layer, in order to improve adhesiveness, it is preferable to perform surface activation processing, such as a corona treatment, with respect to one or both of a bonding surface, for example.

The polarizer layer 103 can be formed directly on the thermoplastic resin film or the base film, and this thermoplastic resin film or the base film may be knitted into the laminate 100 or peeled from the polarizer layer 103 It does not need to be a component of a laminated body.

<Display device>

The display device according to the present invention includes the laminate 100 according to the present invention. A display apparatus is not specifically limited, For example, Image display apparatuses, such as an organic electroluminescent display device, an inorganic electroluminescent display device, a liquid crystal display device, and an electroluminescent display device, are mentioned. The display device may have a touch panel function. The optical laminate is suitable for a display device having flexibility that can be bent or bent.

In a display device, the optical laminated body is arrange|positioned on the visual recognition side of the display element which a display apparatus has toward the outer side (a side opposite to the display element side, ie, the visual recognition side) of a front plate.

The display device according to the present invention can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signs, measuring instruments and instruments, office equipment, medical equipment, computer equipment, and the like.

<Adhesive composition>

The pressure-sensitive adhesive composition according to the present invention is preferably the above-described pressure-sensitive adhesive composition A. The adhesive composition which concerns on this invention can be manufactured by a well-known method, for example by collectively mixing each component using a mixer etc.

<Adhesive sheet>

The pressure-sensitive adhesive sheet according to the present invention preferably includes a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition A.

An adhesive layer can be formed by apply|coating an adhesive composition on a base material. When an active energy ray hardening-type adhesive composition is used as an adhesive composition, it can be set as the hardened|cured material which has a desired degree of hardening by irradiating an active energy ray to the formed adhesive layer. When a thermosetting adhesive composition is used as an adhesive composition, it can be set as the hardened|cured material which has a desired degree of hardening by heat-processing (and curing) to the formed adhesive layer.

The release film to which the release process was given may be sufficient as a base material. An adhesive sheet can be produced by forming the layer which consists of an adhesive on a release film in sheet form, and bonding another peeling film on the adhesive layer.

The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to the present invention has excellent adhesion durability in a normal temperature environment. When the shear modulus at a temperature of 25° C. of a reference pressure-sensitive adhesive layer having a thickness of 150 μm, formed by the pressure-sensitive adhesive composition used to form the pressure-sensitive adhesive layer, is G ₀ [Pa], preferably the following relational expression (4):

1.0×10 ⁴ ≤G ₀ ≤5.0×10 ⁵ (4)

, and more preferably the following relation (4a):

2.0×10 ⁴ ≤G ₀ ≤2.0×10 ⁵ (4a)

satisfy the

Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited by these examples.

(Example)

[Adhesive sheet using thermosetting pressure-sensitive adhesive composition]

[1] Preparation of adhesive sheet A11

(1) Preparation of (meth)acrylic polymer

54 mass parts of n-butyl acrylate, 45 mass parts of 2-ethylhexyl acrylate, and 1 mass part of acrylic acid 4-hydroxybutyl were copolymerized, and the (meth)acrylic-type polymer was prepared. When the molecular weight of this (meth)acrylic-type polymer was measured by the method mentioned later, the weight average molecular weight (Mw) was 800,000.

(2) Preparation of pressure-sensitive adhesive composition

100 parts by mass of the (meth)acrylic polymer obtained in the above step (in terms of solid content; the same hereinafter) and 0.25 parts by mass of trimethylolpropane-modified xylylene diisocyanate (manufactured by Soken Chemicals, product name "TD-75") as a thermal crosslinking agent; and 0.2 parts by mass of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM403") as a silane coupling agent, stirred sufficiently, and diluted with methyl ethyl ketone to obtain a coating solution of the pressure-sensitive adhesive composition got it Each mixing|blending (solid content conversion value) of the adhesive composition at the time of making a (meth)acrylic-type polymer into 100 mass parts (solid content conversion value) is shown in Table 1. In addition, the abbreviation etc. of Table 1 show the following.

BA: n-butyl acrylate

2EHA: 2-ethylhexyl acrylate

4HBA: 4-hydroxybutyl acrylate

(3) Manufacture of adhesive sheet A11

The coating solution of the obtained adhesive composition was apply|coated to the peeling process surface of the hard separator (The Lintec company make, product name "SP-PET752150") with a knife coater. And with respect to the application layer, it heat-processed at 90 degreeC for 1 minute, and the application layer was formed. Next, the application layer on the light separator obtained above and the heavy separator (manufactured by Lintec, product name "SP-PET382120") were bonded together so that the peeling-treated surface of the separator was in contact with the application layer, 23 ° C., By curing under the conditions of 50%RH for 7 days, the pressure-sensitive adhesive sheet A11 having a pressure-sensitive adhesive layer having a thickness of 25 µm, that is, a pressure-sensitive adhesive sheet A11 having the structure of a light separator/adhesive layer (thickness: 25 µm)/medium separator was produced. Let the adhesive layer of adhesive sheet A11 be adhesive layer A11. About the adhesive sheet A11, the measured shear modulus and a gel fraction are shown in Table 1. In addition, the thickness of adhesive layer A11, a shear modulus, and a gel fraction are the values measured by the method mentioned later.

[2] Production of adhesive sheets A12 to A16

(1) Preparation of (meth)acrylic polymer

The ratio of each monomer constituting the (meth)acrylic polymer is prepared as shown in Table 1, and in the same manner as in the manufacturing process of the adhesive sheet A11, a (meth)acrylic polymer having a weight average molecular weight (Mw) shown in Table 1 is prepared. did.

(2) Preparation of pressure-sensitive adhesive composition

100 parts by mass of the (meth)acrylic polymer obtained in the above step, trimethylolpropane-modified xylylene diisocyanate (manufactured by Soken Chemical Co., Ltd., product name "TD-75") as a thermal crosslinking agent, and 3-glycidoxypropyl as a silane coupling agent Trimethoxysilane (the Shin-Etsu Chemical Co., Ltd. make, product name "KBM403") was mixed in the compounding ratio shown in Table 1, fully stirred, and diluted with methyl ethyl ketone to obtain the coating solution of the adhesive composition.

(3) Production of adhesive sheets A12 to A16

Using the coating solution of the obtained adhesive composition, it carried out similarly to the manufacturing process of adhesive sheet A11, and produced adhesive sheets A12-A16. Let the adhesive layers of adhesive sheets A12-A16 be adhesive layers A12-A16. About adhesive sheet A12-A16, the thickness of adhesive layer A12-A16 measured by the method mentioned later, shear modulus, and a gel fraction are shown in Table 1.

[Table 1]

[Adhesive sheet using active energy ray-curable pressure-sensitive adhesive composition]

[1] Manufacture of adhesive sheet A21

(1) Preparation of (meth)acrylic polymer A21

A monomer composed of 92.9 mass % of 2-ethylhexyl acrylate (2-EHA) monomer and 7 mass % of butyl acrylate (BA) monomer in a 1 L reactor equipped with a cooling device so that nitrogen gas is refluxed to facilitate temperature control. After introducing the mixture, nitrogen gas was refluxed for 1 hour to remove oxygen, and then maintained at 80°C. After uniformly mixing the said monomer mixture, 0.05 mass % of photoinitiator benzyl dimethyl ketal (I-651) and 0.05 mass % of 1-hydroxycyclohexyl phenyl ketone (I-184) were prepared. Then, while stirring, a UV lamp (10 mW) was irradiated to prepare (meth)acrylic polymer A21 with a weight average molecular weight (Mw) of 490,000.

Table 2 shows the ratio of each monomer and each component of the acrylic polymer A21. In addition, the abbreviation etc. of Table 2 show the following.

2-EHA: 2-ethylhexyl acrylate (Tokyo Chemical Industry Co., Ltd., Japan)

BA: Butyl acrylate (Tokyo Kasei Kogyo Co., Ltd., Japan)

2-HEA: 2-hydroxyethyl acrylate (Tokyo Chemical Industry Co., Ltd., Japan)

LA: Lauryl acrylate (Tokyo Kasei Kogyo Co., Ltd., Japan)

I-651: benzyl dimethyl ketal (photopolymerization initiator, BASF, Germany)

I-184: 1-hydroxycyclohexylphenyl ketone (photoinitiator, BASF, Germany)

(2) Preparation of pressure-sensitive adhesive composition

95.5 mass % of the (meth)acrylic polymer obtained in the above process (solid content conversion; the same hereinafter) and 1 mass % of isodecyl acrylate (IDA, Miwon specialty chemical, Korea) as an additive and 2-acetoacetoxyethyl methacrylate (AAEM, Sigma-Aldorich, USA) 2.5 mass % and diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO, Tokyo Chemical Industry Co., Ltd., Japan) 0.5 mass % and 1 as a photoinitiator - The coating solution of the adhesive composition was obtained by mixing 0.5 mass % of -hydroxycyclohexylphenyl ketone (I-184, BASF, Germany), fully stirring, and diluting with methyl ethyl ketone. Each compounding (solid content conversion value) of an adhesive composition is shown in Table 3. In addition, the abbreviation etc. of Table 3 show the following.

IDA: isodecyl acrylate (Miwon specialty chemical, Korea)

AAEM: 2-acetoacetoxyethyl methacrylate (Sigma Aldorich, USA)

TPO: diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (Tokyo Chemical Industry Co., Ltd., Japan)

I-184: 1-Hydroxycyclohexylphenylketone (BASF, Germany)

(3) Manufacture of adhesive sheet A21

The coating solution of the obtained adhesive composition was apply|coated to the release-treated surface of a light separator (polyethylene terephthalate film, 38 micrometers in thickness) with a knife coater. Next, the applied layer on the light separator obtained above and a medium separator (polyethylene terephthalate film, 38 µm in thickness) are bonded so that the release-treated surface of the separator is in contact with the coated layer, UV irradiation is performed, and the thickness is 25 The adhesive sheet A21 which has a micrometer adhesive layer, ie, the adhesive sheet A21 which consists of a structure of a light separator/adhesive layer (thickness: 25 micrometers)/medium separator was produced. Let the adhesive layer of adhesive sheet A21 be adhesive layer A21. About the adhesive sheet A21, the measured shear modulus and gel fraction are shown in Table 3. In addition, the thickness of adhesive layer A21, a shear modulus, and a gel fraction are the values measured by the method mentioned later.

[2] Manufacture of adhesive sheets A22 and A23

(1) Preparation of (meth)acrylic polymers A22 and A23

(meth)acrylic polymer A22 of the weight average molecular weight (Mw) shown in Table 2 by preparing the ratio of each monomer which comprises a (meth)acrylic-type polymer as shown in Table 2, carrying out similarly to the manufacturing process of adhesive sheet A21, A23 was prepared.

(2) Preparation of pressure-sensitive adhesive composition

The coating solution of the adhesive composition was obtained by mixing the (meth)acrylic-type polymer obtained by the said process, and an additive at the compounding ratio shown in Table 3, stirring enough, and diluting with methyl ethyl ketone.

(3) Manufacture of adhesive sheets A22 and A23

Using the coating solution of the obtained adhesive composition, it carried out similarly to the manufacturing process of adhesive sheet A21, and produced adhesive sheets A22 and A23. Let the adhesive layers of adhesive sheets A22 and A23 be adhesive layers A22, A23. About the adhesive sheets A22 and A23, the thickness of adhesive layers A22, A23 measured by the method mentioned later, the shear modulus, and the gel fraction are shown in Table 3.

[Table 2]

[Table 3]

<Measurement of weight average molecular weight (Mw)>

The weight average molecular weight (Mw) of the (meth)acrylic polymer was determined as the number average molecular weight (Mn) in terms of polystyrene by the following size exclusion chromatography (SEC) using tetrahydrofuran as a mobile phase.

The (meth)acrylic polymer to be measured was dissolved in tetrahydrofuran at a concentration of about 0.05% by mass, and 10 µL of the polymer was injected by SEC. The mobile phase was flowed at a flow rate of 1.0 mL/min. As the column, PLgel MIXED-B (manufactured by Polymer Laboratories) was used. As a detector, a UV-VIS detector (trade name: Agilent GPC) was used.

<thickness of layer>

It measured using the contact-type film thickness measuring apparatus ("MS-5C" manufactured by Nikon Corporation).

However, about the polarizer layer and the orientation film, it measured using the laser microscope ("OLS3000" made by Olympus Corporation).

<Shear modulus>

The shear modulus was measured using a viscoelasticity measuring apparatus (MCR-301, manufactured by Anton Paar). The same pressure-sensitive adhesive sheets used in Examples and Comparative Examples were cut to a width of 20 mm x length 20 mm. The peeling film was peeled off from the adhesive sheet, and several sheets of adhesive layers were laminated|stacked and bonded to the glass plate so that thickness might be set to 150 micrometers. In a state in which the pressure-sensitive adhesive layer and the measurement chip were adhered, measurement was performed under the conditions of a frequency of 1.0 Hz, a deformation amount of 1%, and a temperature increase rate of 5°C/min in a temperature range from -20°C to 100°C, and the shear modulus value at 25°C was confirmed. .

<Gel fraction>

The obtained pressure-sensitive adhesive sheet is cut to a size of 80 mm x 80 mm, the pressure-sensitive adhesive layer is wrapped with a polyester mesh (mesh size 200), the mass is weighed with a precision balance, and the mass of the mesh alone is subtracted. The mass of the bay was calculated. Let the mass at this time be M1.

Next, the pressure-sensitive adhesive wrapped with the polyester mesh was immersed in ethyl acetate at room temperature (23° C.) for 24 hours. After that, the pressure-sensitive adhesive was taken out, air-dried in an environment of a temperature of 23°C and a relative humidity of 50% for 24 hours, and further dried in an oven at 80°C for 12 hours. After drying, the mass was measured with a precision balance, and the mass of only the adhesive was computed by subtracting the mass of the said mesh independent. Let the mass at this time be M2. The gel fraction (%) is represented by (M2/M1) x 100.

[Front Panel (Window Film)]

As a front plate, the polyimide film (50 micrometers in thickness) which has a hard-coat layer (10 micrometers in thickness) on one side was prepared.

[Polarizer layer]

1. The following materials were prepared.

1) 25㎛ TAC film

2) Composition for forming an alignment layer

<Polymer 1>

Polymer 1 having a photoreactive group composed of the following structural units was prepared.

A solution in which the polymer 1 was dissolved in cyclopentanone at a concentration of 5% by mass was used as a composition for forming an alignment film (hereinafter also referred to as composition (D-1)).

3) Composition for forming a polarizer layer

<Polymerizable liquid crystal compound>

The polymerizable liquid crystal compound is a polymerizable liquid crystal compound represented by formula (1-1) [hereinafter also referred to as compound (1-1)] and a polymerizable liquid crystal compound represented by formula (1-2) [hereinafter referred to as compound ( 1-2) was also used.

Compound (1-1) and compound (1-2) are described in Lub et al. Recl. Trav. Chim. It was synthesized by the method described in Pays-Bas, 115, 321-328 (1996).

<dichroic dye>

The azo dye described in the Example of Unexamined-Japanese-Patent No. 2013-101328 represented by following formula (2-1a), (2-1b), (2-3a) was used for a dichroic dye.

The composition for polarizer layer formation [hereinafter also referred to as composition (A-1)] contains 75 parts by mass of compound (1-1), 25 parts by mass of compound (1-2), and the above formula (2-1a) as a dichroic dye. , (2-1b), (2-3a) each 2.5 parts by mass of the azo dye, 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure369) as a polymerization initiator , BASF Japan Co., Ltd.) 6 parts by mass and 1.2 parts by mass of a polyacrylate compound (BYK-361N, manufactured by BYK-Chemie) as a leveling agent were mixed with 400 parts by mass of toluene as a solvent, and the resulting mixture was stirred at 80°C for 1 hour. prepared by doing

4) Composition for forming a protective layer (OC layer)

The composition for forming a protective layer (OC layer) [hereinafter also referred to as composition (E-1)] is water: 100 parts by mass, polyvinyl alcohol resin powder (manufactured by Kuraray Co., Ltd., average degree of polymerization 18000, trade name: KL- 318): 3 parts by mass, polyamide epoxy resin (crosslinking agent, manufactured by Sumika Chemtex Co., Ltd., trade name: SR650(30)): Prepared by mixing 1.5 parts by mass.

2. How to make

1) The composition for alignment film formation was coated on the TAC film side as follows.

First, corona treatment was performed once on the TAC film side. Conditions for corona treatment were an output of 0.3 KW and a processing speed of 3 m/min. Then, on the said TAC, the composition (D-1) obtained as mentioned above was apply|coated by the bar coating method, and it heat-dried for 1 minute in 80 degreeC drying oven. The obtained dry film was subjected to polarization UV irradiation treatment to form a first alignment film AL1. In the polarization UV treatment, light irradiated from a UV irradiation device (SPOT CURE SP-7; manufactured by Ushio Denki Co., Ltd.) is transmitted through a wire grid (UIS-27132##, manufactured by Ushio Denki Co., Ltd.) at a wavelength of 365 It carried out on condition that the amount of accumulated light measured in nm is 100 mJ/cm<2>. The thickness of the first alignment layer AL1 was 100 nm.

2) The composition for polarizer layer formation was coated on the alignment film side as follows.

On the first alignment film (AL1) formed first, the composition (A-1) was applied by a bar coating method, dried by heating in a drying oven at 120°C for 1 minute, and then cooled to room temperature. The polarizer layer pol was formed by irradiating an ultraviolet-ray to a dry film with the accumulated light amount of 1200 mJ/cm<2> (365 nm standard) using the said UV irradiation apparatus. It was 1.8 micrometers when the thickness of the obtained polarizer layer pol was measured with the laser microscope (Olympus Corporation make; OLS3000). Thus, the laminated body which consists of "TAC/AL1/pol" was obtained.

3) The composition for protective layer (OC layer) formation was coated on the polarizer layer side as follows.

On the formed polarizer layer (pol), the composition (E-1) was apply|coated by the bar coating method, it coated so that the thickness after drying might be set to 1.0 micrometer, and it dried at the temperature of 80 degreeC for 3 minutes. Thus, the laminated body which consists of "TAC film/cPL(AL1+pol+protective layer)" was obtained.

[phase difference layer]

1. Material preparation

The following materials were prepared.

1) 100㎛ thick PET film

2) Composition for forming an alignment layer

<Polymer 1>

Polymer 1 having a photoreactive group composed of the following structural units was prepared.

A solution in which the polymer 1 was dissolved in cyclopentanone at a concentration of 5% by mass was used as a composition for forming an alignment film (hereinafter also referred to as composition (D-1)).

3) Composition for forming retardation layer

The composition (B-1) was obtained by mixing each component shown below and stirring the obtained mixture at 80 degreeC for 1 hour.

Compound b-1 represented by the following formula: 80 parts by mass

Compound b-2 represented by the following formula: 20 parts by mass

Polymerization initiator (Irgacure369, 2-dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one, manufactured by BASF Japan): 6 parts by mass

Leveling agent (BYK-361N, polyacrylate compound, manufactured by BYK-Chemie): 0.1 parts by mass

Solvent (cyclopentanone): 400 parts by mass

2. How to make

1) The composition for forming an alignment film was coated on a PET film as follows.

A polyethylene terephthalate film (PET) having a thickness of 100 µm was prepared as a substrate, the composition (D-1) was applied on the film by a bar coating method, and dried by heating in a drying oven at 80°C for 1 minute. The obtained dry film was subjected to polarization UV irradiation treatment to form a second alignment film AL2. Polarization UV treatment was performed on condition that the amount of accumulated light measured at a wavelength of 365 nm was 100 mJ/cm 2 using the above UV irradiation device. In addition, the polarization direction of polarization|polarized-light UV was performed so that it might become 45 degrees with respect to the absorption axis of a polarizer layer. Thus, the laminated body which consists of "base material (PET)/2nd alignment film (AL2)" was obtained.

2) The composition for forming a retardation layer was coated on the alignment film side of the PET film as follows.

The composition (B-1) was apply|coated by the bar coating method on the 2nd alignment film (AL2) of the 1st base material obtained in this way, and after heating and drying for 1 minute in 120 degreeC drying oven, it cooled to room temperature. The retardation layer was formed by irradiating the ultraviolet-ray of 1000 mJ/cm<2> (365 nm standard) of accumulated light quantity to the obtained dry film using the said UV irradiation apparatus. It was 2.0 micrometers when the thickness of the obtained retardation layer was measured with the laser microscope (OLS3000 manufactured by Olympus Corporation). The retardation layer was a λ/4 plate (QWP) showing a retardation value of λ/4 in the in-plane direction. Thus, the laminated body which consists of "base material (PET)/AL2/QWP" was obtained.

[Common adhesive sheet]

1) Polymerization of acrylic resin

An acrylic resin was obtained by making the following component react at 55 degreeC, stirring in nitrogen atmosphere.

Butyl acrylate: 70 parts by mass

Methyl acrylate: 20 parts by mass

Acrylic acid: 2.0 parts by mass

Radical polymerization initiator (2,2'-azobisisobutyronitrile): 0.2 parts by mass

2) Crude solution of pressure-sensitive adhesive composition

The following components were mixed and the adhesive composition was obtained.

Acrylic resin: 100 parts by mass

Crosslinking agent ("Colonate L" manufactured by Tosoh Corporation): 1.0 mass part

Silane coupling agent ("X-12-981" manufactured by Shin-Etsu Silicone Co., Ltd.): 0.5 parts by mass

Ethyl acetate was added so that total solid content concentration might be 10 mass %, and the adhesive composition was obtained.

3) Preparation of adhesive sheet

The obtained adhesive composition was apply|coated on the release-treated surface of the polyethylene terephthalate film (medium separator, thickness 38 micrometers) by which the release process was carried out so that the thickness after drying might be set to 5 micrometers using an applicator. The application layer was dried at 100 degreeC for 1 minute, and the film provided with an adhesive layer was obtained. Then, on the exposed surface of the adhesive layer, the other polyethylene terephthalate film (light separator, thickness 38 micrometers) by which the mold release process was carried out was pasted together. Thereafter, it was cured for 7 days under conditions of a temperature of 23°C and a relative humidity of 50%RH to obtain a light separator/common pressure-sensitive adhesive layer/medium separator.

[Example 1]

The laminate was manufactured in the procedure shown to Fig.4 (a) - (e). First, the laminate 410 (TAC film 301 / cPL ((AL1 + pol) 302 / OC layer 303)) including the above-described polarizer layer and the above-mentioned common adhesive sheet 420 (light The separator 304/common adhesive layer 305/medium separator 306) was prepared (FIG.4(a)). Corona treatment (output 0.3 KW, speed 3 m/min) was performed on the OC layer 303 side of the laminate 410 including the polarizer layer and the surface on which the light separator 304 of the common adhesive sheet 420 was peeled off. Then, it bonded together and obtained the laminated body a (430). The retardation layer 440 (base material (PET) 308/AL2/QWP(307)) mentioned above was prepared (FIG.4(b)).

Next, after performing corona treatment (output 0.3KW, speed 3m/min) to the QWP (307) side of the retardation layer 440, and the surface from which the middle separator 306 of the laminated body a430 was peeled, bonding, , to obtain a laminate b (450). Then, as the adhesive sheet 460 (light separator 309/adhesive layer 310/medium separator 311), the adhesive sheet A11 produced above was prepared (FIG.4(c)). The pressure-sensitive adhesive layer 310 of the pressure-sensitive adhesive sheet 460 corresponds to the second pressure-sensitive adhesive layer.

Corona treatment (output 0.3 kW, speed 3 m/min) was performed on the surface of the laminate b 450 from which the base material (PET) 308 was peeled and the surface of the pressure-sensitive adhesive sheet 460 from which the light separator 309 was peeled. Then, it bonded together and obtained the laminated body c(470). Further, as the pressure-sensitive adhesive sheet 490 (the light separator 314 / the pressure-sensitive adhesive layer 315 / the medium separator 316), the pressure-sensitive adhesive sheet A12 prepared above was prepared, and the surface from which the light separator 314 was peeled, After corona treatment (output 0.3 KW, speed 3 m/min) on the polyimide film 313 side of one front plate 480 (polyimide film 313/hard coating layer 312), bonding and laminated body d(500) was obtained (FIG. 4(d)). The pressure-sensitive adhesive layer 315 of the pressure-sensitive adhesive sheet 490 corresponds to the first pressure-sensitive adhesive layer.

After performing corona treatment (output 0.3 KW, speed 3 m/min) on the TAC 301 side of the laminated body c (470) and the surface which peeled the middle separator 316 of the laminated body d (500), bonding, A laminate 300 of Example 1 was obtained (FIG. 4(e)). About the laminated body of Example 1, in accordance with the method mentioned later, normal temperature flexibility and normal temperature adhesion durability were evaluated. A result is shown in Table 4.

[Examples 2 to 6, Comparative Examples 1 and 2]

In Example 1, instead of having used the adhesive sheets A11 and A12, except having used the adhesive sheet which has an adhesive layer shown in Table 4, it carried out similarly to Example 1, and Examples 2-6 and Comparative Examples 1 and 2 of the laminate was prepared. About the laminated body of Examples 2-6 and Comparative Examples 1 and 2, normal temperature flexibility and normal temperature adhesion durability were evaluated by the method mentioned later. A result is shown in Table 4.

<Room temperature flexibility>

About the laminated body obtained by each Example and each comparative example, the evaluation test which confirms room temperature flexibility was done using the bending apparatus (Science Town company make, STS-VRT-500). The middle separator 311 was peeled off and bonded to a PET film having a thickness of 100 µm to obtain a laminate. The PET film corresponds to the back plate. 3 : is a figure which shows typically the method of this evaluation test. As shown in Fig. 3, the two individually movable mounting tables 501 and 502 are arranged so that the gap C is 6.0 mm (3R), and the center of the width direction is located at the center of the gap C. In addition, the hard coating layer 312 was positioned at the lower side to fix and arrange the laminate (FIG. 3(a)). Then, the two mounting tables 501 and 502 are rotated 90 degrees upward with the positions P1 and P2 as the centers of the rotation axes, and the bending force (front plate (front plate) 480) to the outside) was added (FIG. 3(b)). After that, the two mounting tables 501 and 502 were returned to their original positions (FIG. 3 (a)). The above series of operations was completed, and the number of times of addition of the bending force was counted once. After repeating this at the temperature of 25 degreeC, the presence or absence of generation|occurrence|production of the bubble in the adhesive layer in the area|region corresponding to the clearance gap C of the mounting tables 501 and 502 of a laminated body was confirmed. The moving speed of the mounting tables 501 and 502 and the additional pace of bending force were made into the same conditions also in the evaluation test with respect to any laminated body. "Adhesive omission" means that an adhesive layer protrudes from the edge part of a laminated body.

A: Even if the number of times of addition of the bending force reached 100,000, bubbles did not generate|occur|produce.

B: Bubbles were generated when the number of times of addition of the bending force was 50,000 or more and less than 100,000.

C: Bubbles were generated when the number of times of addition of the bending force was 20,000 or more and less than 50,000.

D: Bubbles were generated when the number of times of addition of the bending force was 10,000 or more and less than 20,000.

E: When the number of times of adding the bending force was less than 10,000, bubble/adhesive omission occurred.

<Adhesive durability at room temperature>

The laminate obtained by each Example and each comparative example was cut to width 100mm x length 100mm. The medieval separator 311 was peeled off and bonded to alkali-free glass. Compression processing was carried out for about 20 minutes in an autoclave (50 degreeC, 5 atmospheres), and it hold|maintained under constant temperature and humidity conditions (23 degreeC, 50%RH) for 4 hours. The sample was put in 25 degreeC oven, and the presence or absence of a float, peeling, and a bubble was judged after 250 hours. On the other hand, in the laminated body bonded together, an alkali free glass corresponds to a back plate.

(circle): Appearance changes, such as floatation, peeling, foaming, are hardly seen.

(triangle|delta): Appearance changes, such as floatation, peeling, foaming, are slightly conspicuous.

x: Appearance changes, such as a float, peeling, foaming, are recognized remarkably.

[Table 4]

Examples 1 to 6 is, therefore, "G 1≥G _{0 0} 2" satisfies the relationship and the first pressure-sensitive adhesive layer and the same, the thickness of the second pressure-sensitive adhesive layer, be determined to satisfy the relationship of "G1≥G2" can On the other hand, Comparative Examples 1 and 2 is _{a relationship of "G 0} 1 <G ₀ 2", and since the thickness of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are the same, it can be determined that the relationship is "G1 <G2".

100, 200: laminate 101: front plate
102: first pressure-sensitive adhesive layer 103: polarizer layer
104: second pressure-sensitive adhesive layer 105: back plate
106: first retardation layer 107: second retardation layer
108, 109: bonding layer 301: TAC film
302: pol 303: OC layer
305: common adhesive layer 306, 311, 316: middle separator
307: QWP 308: write
304, 309, 314: light separators 310, 315: pressure-sensitive adhesive layer
312: hard coating layer 313: polyimide film
410: laminate including a polarizer layer 420: common adhesive sheet
430: laminate a 440: retardation layer
450: laminate b 460, 490: adhesive sheet
470: laminate c 500: laminate d
501, 502: Stage

Claims (6)

A front plate, a first pressure-sensitive adhesive layer formed using the first pressure-sensitive adhesive composition, a polarizer layer, a second pressure-sensitive adhesive layer formed using the second pressure-sensitive adhesive composition, and a back plate in this order,
When the shear modulus at a temperature of 25° C. of the first pressure-sensitive adhesive layer is G1 [Pa], and the shear modulus at a temperature of 25° C. of the second pressure-sensitive adhesive layer is G2 [Pa], the following relational formula (1):
G1≥G2 (1)
to satisfy,
The said 1st adhesive layer and the said 2nd adhesive layer are a laminated body whose gel fraction is 45% or more and 85% or less. According to claim 1,
The first pressure-sensitive adhesive composition and the second pressure-sensitive adhesive composition both contain a (meth)acrylic polymer,
In the (meth)acrylic polymer, the structural unit derived from the monomer having a reactive functional group is less than 5% by mass based on the total mass, the laminate. 3. The method of claim 1 or 2,
The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer both contain a (meth)acrylic polymer,
The said (meth)acrylic-type polymer is a laminated body whose weight average molecular weights (Mw) are 200,000 or more and 1.5 million or less. 4. The method according to any one of claims 1 to 3,
The back plate is a touch sensor panel, the laminate. A display device comprising the laminate according to any one of claims 1 to 4. 6. The method of claim 5,
A display device capable of being bent with the front plate side facing outward.

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