KR20210141521A - A laminate and a display device including the same - Google Patents

Abstract

An object of this invention is to provide the laminated body which improved durability by suppressing generation|occurrence|production of the bubble in an adhesive layer. The present invention is a laminate comprising 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 As, so that the thickness of the first pressure-sensitive adhesive reference layer and the thickness of the second pressure-sensitive adhesive reference layer are the same, the first pressure-sensitive adhesive composition is used to form the first pressure-sensitive adhesive reference layer, and the second pressure-sensitive adhesive composition is used to form the second pressure-sensitive adhesive reference layer. In this case, the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer satisfy the relationship of ΔR1>ΔR2, to provide a laminate.

Description

A laminate and a display device including the same

The present invention relates to a laminate and a display device including the same.

Korean Patent No. 10-2016-0053788 (Patent Document 1) and Korean Patent No. 10-2017-0093610 (Patent Document 2) describe a laminate for a display device having a plurality of pressure-sensitive adhesive layers, respectively.

Korean Patent No. 10-2016-0053788 Korean Patent No. 10-2017-0093610

The pressure-sensitive adhesive layer employed in this type of laminate is generally excellent in stress relaxation performance for relieving external stress. However, since bubbles are often generated in the pressure-sensitive adhesive layer when the laminate is bent at room temperature, it is required to improve the durability of the pressure-sensitive adhesive layer.

In view of the said situation, this invention aims at providing the laminated body which improved durability by suppressing generation|occurrence|production of the bubble in an adhesive layer, and the display apparatus containing the same.

The present invention provides the following laminates and a display device including the same.

[1] A laminate comprising 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 first pressure-sensitive adhesive reference layer is formed using the first pressure-sensitive adhesive composition so that the thickness of the first pressure-sensitive adhesive reference layer is equal to the thickness of the second pressure-sensitive adhesive reference layer, the second pressure-sensitive adhesive reference layer is formed using the second pressure-sensitive adhesive composition, Wherein the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer satisfy the relationship of the following formula (1), the laminate.

ΔR1>ΔR2 (One)

[In formula (1), ΔR1 represents a value obtained by subtracting R1B from R1A,

ΔR2 represents a value obtained by subtracting R2B from R2A,

R1A represents a first shear creep rate (%/μm), which is a shear creep value per 1 μm in thickness at 25° C. obtained for the first pressure-sensitive adhesive reference layer after performing the strain repeated addition test,

R1B represents a second shear creep rate (%/μm), which is a shear creep value per 1 μm in thickness at 25° C. obtained for the first pressure-sensitive adhesive reference layer before performing the strain repeated addition test,

R2A represents the third shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. calculated for the second pressure-sensitive adhesive reference layer after performing the strain repeated addition test,

R2B represents the fourth shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. calculated for the second pressure-sensitive adhesive reference layer before performing the strain repeated addition test.]

[2] The laminate according to [1], wherein the fourth shear creep rate (%/μm) is 0.1 or more and 0.2 or less.

[3] The laminate according to [1] or [2], wherein at least one of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer has a thickness of 20 µm or more and 50 µm or less.

[4] The laminate according to any one of [1] to [3], comprising one or more retardation layers between the polarizer layer and the back plate.

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

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

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

ADVANTAGE OF THE INVENTION According to this invention, the laminated body which improved durability by suppressing generation|occurrence|production of the bubble in an adhesive layer, and the display apparatus containing it can be provided.

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 another example of the laminate according to the present invention.
3 is a cross-sectional view schematically showing a manufacturing method of the laminate according to the present 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 is a front plate 101, a first pressure-sensitive adhesive layer 102 formed using the first pressure-sensitive adhesive composition, a polarizer layer 103, and a second pressure-sensitive adhesive layer formed using the second pressure-sensitive adhesive composition. 104 and the rear plate 105 are included in this order. Hereinafter, the 1st adhesive layer 102 and the 2nd adhesive layer 104 may be generically called "adhesive layer".

The thickness of the laminate 100 is not particularly limited because it varies depending on the function required for the laminate and the use of the laminate, but is, for example, 30 µm or more and 1500 µm or less, preferably 40 µm or more and 1000 µm or less. , more preferably 50 µm or more and 500 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 may be 5 mm or more and 800 mm or less, for example, Preferably they are 30 mm or more and 500 mm or less, More preferably, they are 50 mm or more and 300 mm or less. As for each layer which comprises a laminated body, each part may be R-processed, an edge part may be notched, or punching process may be carried out.

The laminate 100 can be applied, for example, to 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. Moreover, the display device to which the laminated body 100 is applied can be used as a flexible display in which bending, winding, etc. are possible. It is preferable that the display device be bendable with the front plate 101 side facing outward. However, the laminate 100 may be bent with the front plate 101 side inside.

[Adhesive layer (a first pressure-sensitive adhesive layer formed using the first pressure-sensitive adhesive composition, and a second pressure-sensitive adhesive layer formed using the second pressure-sensitive adhesive composition)]

The laminate 100 includes the first pressure-sensitive adhesive layer 102 formed using the first pressure-sensitive adhesive composition as described above, and the second pressure-sensitive adhesive layer 104 formed using the second pressure-sensitive adhesive composition. In the laminate 100 , the following relationship is established between the first pressure-sensitive adhesive composition used to form the first pressure-sensitive adhesive layer 102 and the second pressure-sensitive adhesive composition used to form the second pressure-sensitive adhesive layer 104 . do. That is, the first pressure-sensitive adhesive reference layer was formed using the first pressure-sensitive adhesive composition so that the thickness of the first pressure-sensitive adhesive reference layer and the thickness of the second pressure-sensitive adhesive reference layer were the same, and the second pressure-sensitive adhesive reference layer was formed using the second pressure-sensitive adhesive composition. In this case, the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer satisfy the relationship of the following formula (1). The thickness of the first pressure-sensitive adhesive reference layer and the thickness of the second pressure-sensitive adhesive reference layer may be, for example, 200 μm.

ΔR1>ΔR2 (One)

[In formula (1), ΔR1 represents a value obtained by subtracting R1B from R1A,

ΔR2 represents a value obtained by subtracting R2B from R2A,

R1A represents the first shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. obtained for the first pressure-sensitive adhesive reference layer after performing the strain repeated addition test,

R1B represents the second shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. calculated for the first pressure-sensitive adhesive reference layer before performing the strain repeated addition test,

R2A represents the third shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. obtained for the second pressure-sensitive adhesive reference layer after performing the strain repeated addition test,

R2B represents the fourth shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. calculated for the second pressure-sensitive adhesive reference layer before performing the strain repeated addition test].

On the other hand, the shear creep value at 25°C (%), the first shear creep ratio (%/μm) representing R1A, the second shear creep ratio (%/μm) representing R1B, and the third shear creep ratio representing R2A ( %/μm) and the fourth shear creep rate (%/μm) representing R2B can be obtained according to the measurement methods described in the Examples column, respectively, which will be described later.

In the laminate 100, the first pressure-sensitive adhesive layer 102 and the second pressure-sensitive adhesive layer 104, which are the pressure-sensitive adhesive layers included therein, satisfy the relationship of the above formula (1). It is formed by using the 1st adhesive composition and 2nd adhesive composition which can comprise. In this case, the laminate 100 can improve durability by suppressing generation|occurrence|production of a bubble in an adhesive layer. In particular, when the laminate 100 is bent with the front plate 101 side outward, the generation of bubbles in the pressure-sensitive adhesive layer can be further suppressed. Therefore, it is suitable for the laminated body 100 to be used for the laminated body of the system (a so-called out-folding system) which bends with the front-plate side outward, and a display device including the same.

The first pressure-sensitive adhesive layer 102 and the second pressure-sensitive adhesive layer 104 are a first pressure-sensitive adhesive composition and a second pressure-sensitive adhesive composition that can constitute a first pressure-sensitive adhesive reference layer and a second pressure-sensitive adhesive reference layer satisfying the relationship of Formula (1), respectively. When formed, the reason why the above-mentioned effect is obtained is not clear in detail, but it is thought to be based on the following mechanism. First, in the course of research by the present inventors, it was discovered that when the laminate was bent with the front plate side facing outward, bubbles were sometimes generated in the pressure-sensitive adhesive layer. In that case, it was revealed that most of the location where a bubble generate|occur|produced was the adhesive layer on the side far from the front plate, ie, the 2nd adhesive layer side.

Here, when the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer satisfy the relationship of Formula (1), the second pressure-sensitive adhesive composition is, compared to the first pressure-sensitive adhesive composition, before and after the deformation is repeatedly added, shear It means that the change in creep rate (%/μm) is a smaller composition. Moreover, the characteristic that the change of shear creep rate (%/micrometer) is smaller means that it is excellent in the performance (namely, durability) which can maintain the characteristic inherent in an adhesive layer against external stress. Therefore, the pressure-sensitive adhesive layer (second pressure-sensitive adhesive layer 104) formed by using the second pressure-sensitive adhesive composition, compared to the pressure-sensitive adhesive layer (first pressure-sensitive adhesive layer 102) formed using the first pressure-sensitive adhesive composition, durability against bending I think it could be better than this.

From the above, the present inventors, as the pressure-sensitive adhesive layer on the side far from the front plate, in which bubbles are bundled when the laminate is bent with the front plate side outward, is formed using a second pressure-sensitive adhesive composition having better durability against bending. A layer (the second pressure-sensitive adhesive layer 104) was disposed. Thereby, when the laminated body 100 was bent with the front plate 101 side turned outward, it reached|attained the laminated body 100 which can suppress generation|occurrence|production of the bubble in an adhesive layer. Specifically, as will be shown in Examples to be described later, the laminate 100 is a mandrel (mandrel) which is a cylindrical jig with a diameter (φ) of more than 10 mm and not more than 15 mm inside the back plate 105 side. Even when the laminate 100 is folded and bent along the core rod, the generation of air bubbles in the pressure-sensitive adhesive layer can be suppressed (hereinafter, this performance is also referred to as “excellent bending durability”).

In the present specification, the term "bending" includes a form of folding in which a curved surface is formed in a bent portion. In the form of bending, the radius of curvature of the bent inner surface is not limited unless otherwise noted. In addition, unless otherwise specified, "bending" includes a form of refraction in which the refraction angle of the inner surface is greater than 0 degrees and less than 180 degrees, and also includes a folding form in which the radius of curvature of the inner surface is close to zero or the refraction angle of the inner surface is 0 degrees. .

It is preferable that it is 0.01-4, respectively, as for the value of ?R1 and ?R2, it is more preferable that it is 0.05-0.5, It is still more preferable that it is 0.05-0.2.

It is preferable that it is 0.05-1.0, and, as for 1st shear creep rate R1A (%/micrometer), it is more preferable that it is 0.2-0.5. It is preferable that it is 0.01-0.3, and, as for 2nd shear creep rate R1B (%/micrometer), it is more preferable that it is 0.05-0.2. It is preferable that it is 0.05-1.0, and, as for 3rd shear creep rate R2A (%/micrometer), it is more preferable that it is 0.2-0.5. It is preferable that it is 0.01-0.3, and, as for 4th shear creep rate R2B (%/micrometer), it is more preferable that it is 0.05-0.2.

In the laminate 100, it is preferable that the said 4th shear creep rate (%/micrometer) is 0.1 or more and 0.2 or less. In this case, since the 2nd adhesive layer 104 becomes an adhesive layer provided with moderate hardness in addition to the outstanding flexibility and durability, the laminated body 100 can provide the outstanding surface hardness. Specifically, when a load of 100 g is applied to the surface of the back plate 105 of the laminate 100 using a pencil having a core hardness of 6B, as shown in Examples to be described later. , it is possible to eliminate the concave marks formed on the surface in less than 1 hour (hereinafter, this performance is also referred to as excellent in "surface hardness").

40 to 90 % may be sufficient as the gel fraction of an adhesive layer, and 50 to 80 % may be sufficient as it. The gel fraction of the pressure-sensitive adhesive layer is measured according to the method described in Examples to be described later.

Moreover, in the laminated body 100, it is preferable that the thickness of at least one of the 1st adhesive layer 102 and the 2nd adhesive layer 104 is 20 micrometers or more and 50 micrometers or less.

Here, as a method of preparing the first pressure-sensitive adhesive composition and the second pressure-sensitive adhesive composition constituting the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer that satisfy the relationship of Formula (1), these are, for example, as pressure-sensitive adhesive composition A to be described later. The method of changing the kind of monomer which comprises, or which comprises the (meth)acrylic-type polymer A mentioned later, or adjusting the molecular weight of the (meth)acrylic-type polymer A, etc. are mentioned. Hereinafter, the adhesive composition A is demonstrated concretely.

<Adhesive composition A>

Although the composition of both the 1st adhesive layer 102 and the 2nd adhesive layer 104 are different, both are the adhesive composition (henceforth "adhesive composition A") containing a (meth)acrylic-type polymer in the one form. ) can be formed. The adhesive composition A may be an active energy ray hardening type or a thermosetting type. In this specification, "(meth)acrylic polymer" represents 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 to which "(meta)" is assigned. Regarding a 1st adhesive composition and a 2nd adhesive composition, when any contains a (meth)acrylic-type polymer, the (meth)acrylic-type polymer may be same or different. Hereinafter, the (meth)acrylic-type polymer contained in the adhesive composition A is also called "(meth)acrylic-type polymer A."

(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 has a structural unit derived from a monomer having a reactive functional group, preferably, based on the total mass of the polymer It is 1 mass % or less. Examples of the reactive functional group include a hydroxyl group, a carboxy group, an amino group, an amide group, and an epoxy group. Thereby, the flexibility of an adhesive layer improves, and there exists a tendency which becomes easy to suppress generation|occurrence|production of the bubble in the adhesive layer at the time of normal temperature. (meth)acrylic polymer A, the structural unit derived from the monomer having a reactive functional group, from the viewpoint of suppressing the generation of bubbles at the time of bending, more preferably 0.01 mass % or less based on the total mass of the polymer, more Preferably, it does not have a structural unit derived from the monomer which has a reactive functional group, More preferably, it does not have a hydroxyl group, a carboxy group, an amino group, an amide group, and an epoxy group.

The (meth)acrylic polymer A can contain the structural unit derived from the (meth)acrylic-type monomer which has a linear or branched C1-C24 alkyl group. 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, 100,000 or more and 2 million or less, and preferably 500,000 or more and 1.5 million or less from the viewpoint of bubble suppression at the time of bending. The weight average molecular weight in this specification can be calculated|required based on the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method so that it may demonstrate 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. Moreover, 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, which 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, 3 mass parts or less, More preferably, 1 It is a mass part or less, More preferably, it is 0.5 mass part or less. The adhesive composition A may 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 be adhered to an adherend such as a film, and the active energy rays It is an adhesive composition which hardens by irradiation and has the property which can adjust adhesive force etc. 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; A (meth)acrylic compound that is obtained by reacting two or more functional group-containing compounds and is a (meth)acryloyloxy group-containing compound such as a (meth)acrylate oligomer having at least two (meth)acryloyloxy groups in the molecule can be heard 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, benzophenone, benzyl dimethyl ketal, 1-hydroxycyclohexyl 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.

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 or 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 problem of 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.

(thermosetting 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). When the pressure-sensitive adhesive composition A is a thermosetting pressure-sensitive adhesive composition, it is preferable to further contain a thermal crosslinking agent.

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. A (meth)acrylic acid alkylester having an alkyl group having 2 to 20 carbon atoms is, for example, a homopolymer having a glass transition temperature (Tg) of -40°C or less (hereinafter referred to as “low Tg alkyl acrylate” in some cases). It is preferable to include By containing the low-Tg alkyl acrylate as a constituent monomer unit, the flexibility of the pressure-sensitive adhesive layer is improved, and therefore the generation of bubbles during bending can be more easily suppressed. The glass transition temperature (Tg) of the (meth)acrylic polymer A can be calculated|required by using conventionally well-known methods, such as a differential thermal analysis method (DTA).

Examples of the low Tg alkyl acrylate include n-butyl acrylate (Tg-54° 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. Especially, as a low Tg alkyl acrylate, it is more preferable that Tg of a homopolymer is -45 degrees C or less, and it is especially preferable that it is -50 degrees C or less. 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.

Moreover, as for the (meth)acrylic-type 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 mass % or less is more preferable. By containing 99.9 mass % or less of the said low Tg alkyl acrylate, the other monomer component (particularly reactive functional group containing monomer) of a suitable quantity can be introduce|transduced into the (meth)acrylic-type polymer A.

(meth)acrylic polymer A, from the viewpoint of further exhibiting the effect of the present invention, the glass transition temperature (Tg) as a homopolymer exceeds 0 ° C. The content of the monomer (hereinafter referred to as "hard monomer") It is preferable to make it 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. This hard monomer also contains the reactive functional group containing monomer mentioned later.

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), acrylate n-stearyl (Tg30°C), methacrylate 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 (Tg105℃), dimethyl acrylamide (Tg89℃), acrylamide Acrylic monomers, such as (Tg165 degreeC), vinyl acetate (Tg32 degreeC), styrene (Tg80 degreeC), etc. are mentioned.

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

As a reactive functional group-containing monomer that (meth)acrylic polymer A contains as a monomer unit constituting the polymer, a monomer having a hydroxyl group in the molecule (hydroxyl group-containing monomer), a monomer having a carboxyl group in the molecule (carboxy group-containing monomer), in the molecule A monomer (amino group-containing monomer) etc. which have an amino group 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.

The (meth)acrylic polymer A, as a monomer unit constituting the polymer, preferably contains 0.1 mass % or more of the reactive functional group-containing monomer as a lower limit, particularly preferably 0.5 mass % or more, and further 1 mass % or more is preferable. As for the (meth)acrylic polymer A, it is preferable to contain 10 mass % or less of the said reactive functional group containing monomer as an upper limit, It is especially preferable to contain 8 mass % or less, Furthermore, it is preferable to contain 5 mass % or less. Thereby, there exists a tendency which can suppress more easily generation|occurrence|production of the bubble at the time of bending|flexion.

The (meth)acrylic polymer A may not contain a carboxyl group-containing monomer, particularly acrylic acid which is also a hard monomer, as a monomer unit constituting the polymer. Since the carboxyl group is an acid component, by not containing a carboxyl group-containing monomer, an acid may cause a problem in the affixing target of the pressure-sensitive adhesive, for example, a transparent conductive film such as tin-doped indium oxide (ITO), a metal film, or a metal Even when a mesh or the like is present, 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 said other monomer, for example, (meth)acrylic acid alkoxyalkyl esters, such as (meth)acrylic acid methoxyethyl and (meth)acrylic acid ethoxyethyl, the glass transition temperature (Tg) as a homopolymer is more than -40 degreeC, and 0 and a monomer (hereinafter, sometimes referred to as "medium Tg alkyl acrylate") having a temperature of °C or lower. 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. The weight average molecular weight in this specification can be calculated|required based on the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method so that it may demonstrate in the column of the Example mentioned later.

It is preferable that it is 2 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 1.5 million or less, Furthermore, it is preferable that it is 1.3 million or less. When the upper limit of the weight average molecular weight of the (meth)acrylic acid ester polymer (A) is below the above, the flexibility of the pressure-sensitive adhesive layer can be ensured, whereby the effects of the present invention can be easily exhibited.

The adhesive composition A WHEREIN: (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, cohesive force can be improved while ensuring the flexibility of an adhesive, and when applied to a laminated body, the hardness which can improve the surface hardness of the said laminated body can be 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. 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 isocyanates, etc., and their biuret forms, isocyanurate forms, and also reaction products with low-molecular active hydrogen-containing compounds 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 said range, moderate hardness can be acquired more easily by the improvement of cohesive force.

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

As a silane coupling (SC) 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 it is preferable that it has light transmittance.

As the silane coupling agent, for example, a silicon compound containing a polymerizable unsaturated group such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, Silicon compound 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, adhesiveness with each member in a laminated body can be improved more.

The various additives mentioned above can be added to adhesive composition A as needed. In this specification, 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-carbonie) 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.

The said polymerization process WHEREIN: By mix|blending chain transfer agents, such as 2-mercaptoethanol, the weight average molecular weight of the polymer obtained can be adjusted.

When the (meth)acrylic polymer A is obtained, a thermal crosslinking agent, a silane coupling agent, and optionally an additive and a diluting solvent are added to the solution of the (meth)acrylic polymer A, and the adhesive composition A diluted in the solvent by sufficiently mixing ( application solution) can be obtained. The adhesive composition A can be manufactured by a well-known method by collectively mixing each component using a mixer etc., for example. Moreover, a 1st adhesive composition and a 2nd adhesive composition can be prepared from the adhesive composition A obtained in this way.

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 You may mix 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

As a density|concentration and viscosity of the adhesive composition A (coating solution) prepared in this way, what is necessary is just to be a range which can be coated, It does not restrict|limit especially, According to a situation, it can select suitably. For example, it can prepare so that it may become 10-60 mass % in a solution as a density|concentration of adhesive composition A. In obtaining a coating solution, addition of a diluent solvent etc. is not a necessary condition, and as long as the adhesive composition A is a coating-able viscosity etc., it is not necessary to add a dilution solvent. In this case, the adhesive composition A turns into the coating solution which used the polymerization solvent of the (meth)acrylic-type polymer A as a dilution solvent as it is.

An adhesive layer can be obtained by bridge|crosslinking the said adhesive composition A. The pressure-sensitive adhesive composition A can be crosslinked by heat treatment. The said heat processing can also serve as the 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 in heat processing, it is more preferable that it is 70-120 degreeC. It is preferable that they are 10 second - 10 minutes, and, as for the heating time in heat processing, 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 can be provided at room temperature (eg, 23°C, 50%RH). When this curing period is required, the pressure-sensitive adhesive layer can be formed after the curing period has elapsed. When a curing period is unnecessary, an adhesive layer can be formed after completion|finish of the heat processing mentioned above.

By the heat treatment (and curing) described above, the (meth)acrylic polymer A is sufficiently crosslinked through the crosslinking agent to form a crosslinked structure, thereby forming the pressure sensitive adhesive layer (the first pressure sensitive adhesive layer 102 and the second pressure sensitive adhesive layer 104). )) can be obtained.

<Adhesive sheet>

The pressure-sensitive adhesive sheet may include a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition A. An adhesive layer can be formed by apply|coating adhesive composition A on a base material. When an active energy ray hardening-type 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 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 mold release process was given may be sufficient as the said base material. An adhesive sheet can be produced by apply|coating the adhesive composition A on a release film, forming an adhesive layer 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.

[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 1000 µm or less, preferably 20 µm or more and 500 µm or less, and more preferably 30 µm or more and 300 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|macromolecule 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.

It is preferable that the front plate 101 is a film in which the hard-coat layer was provided in at least one surface of a base film from a viewpoint of 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 intensity|strength. 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 1000 micrometers or less, for example, and 50 micrometers or more and 1000 micrometers or less may be sufficient as them. 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 102 may be a pressure-sensitive adhesive layer disposed at a position closest to the front plate 101 among the pressure-sensitive adhesive layers constituting the laminate 100 . Here, in this specification, an "adhesive agent" is also called a pressure-sensitive adhesive. In addition, in this specification, "adhesive" means adhesives other than an adhesive (pressure-sensitive adhesive), and is clearly distinguished from an adhesive. One layer may be sufficient as the 1st adhesive layer 102, Although what consists of two or more layers may be sufficient as it, Preferably it is one layer.

The 1st adhesive layer 102 is formed using the 1st adhesive composition as mentioned above. The first pressure-sensitive adhesive composition may be formed using the pressure-sensitive adhesive composition A as described above. The first pressure-sensitive adhesive layer 102 is formed such that the thickness of the first pressure-sensitive adhesive reference layer is equal to the thickness of the second pressure-sensitive adhesive reference layer, the first pressure-sensitive adhesive composition is used to form the first pressure-sensitive adhesive reference layer, and a second pressure-sensitive adhesive composition to be described later is used. Thus, when the second pressure-sensitive adhesive reference layer is formed, the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer satisfy the relationship of formula (1) expressed by ΔR1 > ΔR2. The thickness of the first pressure-sensitive adhesive reference layer and the thickness of the second pressure-sensitive adhesive reference layer may be, for example, 200 µm. The first pressure-sensitive adhesive composition is not limited to the pressure-sensitive adhesive composition A, as long as the above formula (1) is satisfied in relation to the second pressure-sensitive adhesive composition, and can be formed directly from any pressure-sensitive adhesive composition, or any pressure-sensitive adhesive composition It can be formed using the adhesive sheet which has the adhesive layer formed using it. However, it is also preferable to form the 1st adhesive composition from the adhesive composition A mentioned above, or it is also preferable to form using the adhesive sheet formed by apply|coating the adhesive composition A mentioned above on a base material.

That is, the first pressure-sensitive adhesive layer 102 is a composition and compounding component of the first pressure-sensitive adhesive composition constituting it, the type of the first pressure-sensitive adhesive composition (active energy ray curing type, thermosetting type, etc.), and additives that can be formulated in the first pressure-sensitive adhesive composition , With respect to the manufacturing method of the first pressure-sensitive adhesive layer, the thickness of the first pressure-sensitive adhesive layer, etc., the [Adhesive layer (a first pressure-sensitive adhesive layer formed using the first pressure-sensitive adhesive composition, and a second pressure-sensitive adhesive layer formed using the second pressure-sensitive adhesive composition) It can be done as described in the column of ].

In the laminated body 100, it is preferable that the thickness of at least one of the 1st adhesive layer 102 and the 2nd adhesive layer 104 is 20 micrometers or more and 50 micrometers or less. For this reason, the thickness of the 1st adhesive layer 102 may be 3 micrometers or more and 100 micrometers or less, for example, It is preferable that they are 5 micrometers or more and 50 micrometers or less, and 20 micrometers or more may be sufficient. As for the 1st adhesive layer 102, it is most preferable that the thickness is 20 micrometers or more and 50 micrometers or less.

[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 the dichroic dye, specifically, iodine or a dichroic organic dye is 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.

In the laminated body 100, the polarizer layer 103 can function as a circularly polarizing plate by combination with the retardation layer mentioned later, for example.

<A polarizer layer which is a stretched film or a stretched 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-based resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with aldehydes can be used. The polymerization degree of polyvinyl alcohol-type resin is 1000 or more and 10000 or less normally, Preferably they are 1500 or more and 5000 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. The polarizer layer which is the extending|stretching layer to which the dichroic dye was adsorbed 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.

The thermoplastic resin film may or may not have retardation. 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. μm or less. The thickness of a thermoplastic resin film is 5 micrometers or more normally, Preferably it is 20 micrometers or more. A thermoplastic resin film can be bonded to the polarizer layer 103 using an adhesive bond layer, for example.

<The polarizer layer formed by apply|coating and hardening the composition containing a dichroic dye and a polymeric 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.

The polarizer layer formed by apply|coating and hardening the composition containing a dichroic dye and a polymeric compound 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 105 among the pressure-sensitive adhesive layers constituting the laminate 100 . 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 second pressure-sensitive adhesive layer 104 is formed using the second pressure-sensitive adhesive composition as described above. The second pressure-sensitive adhesive composition may be formed using the pressure-sensitive adhesive composition A as described above. The second pressure-sensitive adhesive layer 104 uses the second pressure-sensitive adhesive composition to form a second pressure-sensitive adhesive reference layer so that the thickness of the first pressure-sensitive adhesive reference layer is equal to the thickness of the second pressure-sensitive adhesive reference layer, and the above-described first pressure-sensitive adhesive composition is used. Thus, when the first pressure-sensitive adhesive reference layer is formed, the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer satisfy the relationship of formula (1) expressed by ΔR1 > ΔR2. The thickness of the first pressure-sensitive adhesive reference layer and the thickness of the second pressure-sensitive adhesive reference layer may be, for example, 200 µm. The second pressure-sensitive adhesive composition is not limited to the pressure-sensitive adhesive composition A, as long as the above formula (1) is satisfied in relation to the first pressure-sensitive adhesive composition, and may be formed directly from any pressure-sensitive adhesive composition, or any pressure-sensitive adhesive composition It can be formed using the adhesive sheet which has the adhesive layer formed using it. However, it is also preferable to form the 2nd adhesive composition from the adhesive composition A mentioned above, or it is also preferable to form using the adhesive sheet formed by apply|coating the adhesive composition A mentioned above on a base material.

That is, although the composition of the 2nd adhesive layer 104 differs from the 1st adhesive layer 102, it is common in that it is preferable that it is formed from the adhesive composition A. FIG. For this reason, the 2nd adhesive layer 104 is mix|blended with the composition and compounding component of the 2nd adhesive composition which comprises this, the type of 2nd adhesive composition (whether it is an active energy ray hardening type or thermosetting type, etc.), and a 2nd adhesive composition Regarding the additives that can be used, the method of manufacturing the second pressure-sensitive adhesive layer and the thickness of the second pressure-sensitive adhesive layer, 2 pressure-sensitive adhesive layer)].

In the laminated body 100, it is preferable that the thickness of at least one of the 1st adhesive layer 102 and the 2nd adhesive layer 104 is 20 micrometers or more and 50 micrometers or less. For this reason, the thickness of the 2nd adhesive layer 104 may be 3 micrometers or more and 100 micrometers or less, for example, It is preferable that they are 5 micrometers or more and 50 micrometers or less, and 20 micrometers or more may be sufficient. As for the 2nd adhesive layer 104, it is most preferable that the thickness is 20 micrometers or more and 50 micrometers or less.

[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 back plate 105 may be 5 micrometers or more and 2000 micrometers or less, for example, Preferably, they are 10 micrometers or more and 1000 micrometers or less, More preferably, they are 15 micrometers or more and 500 micrometers 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 device, 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. The back plate 105 is preferably a touch sensor panel.

(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 capacitively coupled 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 2000 µm or less, or 5 µm or more and 100 µm or less.

[phase difference layer]

The laminate 100 may have one or more retardation layers 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

Examples of the retardation layer include positive A plates such as λ/4 plates and λ/2 plates, positive C plates, and the like. The retardation layer may be, for example, a retardation film that can be formed from the above-described 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.

[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 pressure-sensitive adhesive as exemplified for the pressure-sensitive adhesive composition constituting the first pressure-sensitive adhesive layer 102 and the second pressure-sensitive adhesive layer 104, and another pressure-sensitive adhesive, for example, a (meth)acrylic pressure-sensitive adhesive; A styrene-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a rubber-based pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, a polyester pressure-sensitive adhesive, an epoxy-based copolymer pressure-sensitive adhesive, or the like may be used.

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, and 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 laminate 200 according to another aspect of the present invention, for example, as shown in FIG. 2, the front plate 101, the first pressure-sensitive adhesive layer 102, the polarizer layer 103, the second pressure-sensitive adhesive layer ( 104 ) and the back plate 105 , and may further include a bonding layer 108 , a first retardation layer 106 , a bonding layer 109 , and a second retardation layer 107 .

[Method for producing a laminate]

The laminated bodies 100 and 200 can be manufactured according to the method including the process of bonding the layers which comprise the laminated bodies 100 and 200 through an adhesive layer or an adhesive bond layer further. When bonding layers through an adhesive layer or an adhesive bond layer, for the purpose of improving adhesiveness, it is preferable to perform surface activation treatment, 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 a thermoplastic resin film or a base film, and this thermoplastic resin film or base film may be knitted into the laminates 100 and 200 , or from the polarizer layer 103 . It is not necessary to peel off and not become a component of a laminated body.

<Display device>

A display device according to an aspect of the present invention includes the stacked bodies 100 and 200 . 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.

Since durability is improved by suppressing generation|occurrence|production of air bubble in the adhesive layer, the said laminated body 100 and 200 is suitable for the display apparatus which has the flexibility which can bend, fold, or the like.

In the display device, the stacked bodies 100 and 200 are disposed on the viewing side of the display element included in the display device with the front plate facing outward (the side opposite to the display element side, that is, the viewing side). It is preferable that the display device is bendable with the front plate 101 side of the laminates 100 and 200 facing outward.

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, instruments, office equipment, medical equipment, computer equipment, and the like.

(Example)

Hereinafter, although an Example demonstrates this invention in more detail, this invention is not limited by these examples. In this Example, when explaining using the terms "%" and "part", unless otherwise specified, such terms mean mass % and mass parts.

[How to measure]

The measuring method and calculation method of each physical property value (weight average molecular weight, each physical property of an adhesive layer, etc.) used for this Example are as follows.

<Measurement of weight average molecular weight (Mw)>

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

Specifically, the (meth)acrylic polymer A as the measurement target was dissolved in tetrahydrofuran at a concentration of about 0.05% by mass, and 10 µL 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 the 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" manufactured by Olympus Corporation).

<Deformation repeated additional test>

The strain repeated addition test was performed by using a viscoelasticity measuring apparatus (MCR-301, Anton Paar company). The specific test method is as follows. That is, by cutting an adhesive sheet (adhesive sheet A11, adhesive sheet A12, etc.) with an adhesive layer described later to a width of 20 mm x length 20 mm, and peeling the release film and laminating 8 sheets, an adhesive reference layer having a thickness of 200 µm (Production 1 pressure-sensitive adhesive reference layer and a second pressure-sensitive adhesive reference layer) were formed.

Next, this pressure-sensitive adhesive reference layer was bonded to the glass plate. In addition, with respect to the pressure-sensitive adhesive reference layer on the glass plate, under the conditions of a temperature of 25° C., Normal Force Free, and a frequency of 2 Hz in a state of being adhered to the measurement chip in the device, 0% and 1000% Strin (strain) (unit is “%”) A strain repeated addition test was performed by repeatedly adding and advancing for 1000 seconds (thus, 0% and 1000% Strin (strain) is repeatedly added over 1000 seconds to the pressure-sensitive adhesive sheet).

<Shear creep value and shear creep rate>

For the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer before the modified repeated addition test, and the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer after the modified repeated addition test were performed, 25 ° C. using the following method, respectively The shear creep value (unit is "%") was calculated|required. That is, the shear creep value in 25 degreeC was calculated|required by measuring using the said viscoelasticity measuring apparatus (MCR-301, Anton Paar company). Specifically, with respect to the pressure-sensitive adhesive reference layer on the glass plate before performing the above-mentioned strain repeated addition test or after executing the above-mentioned strain repeated addition test, in the state in which it adheres to the measurement chip in the device, the temperature is 25°C, Normal Force 1N, Torque The shear creep value at the elapsed time was calculated|required by making 1200 second pass under the conditions of 1200 microNm.

In addition, each value obtained as a shear creep value before and behind performing a deformation|transformation repeated addition test was divided by the thickness (200 micrometers) of a 1st adhesive reference|standard layer or a 2nd adhesive reference|standard layer. Accordingly, the first shear creep rate (R1A, unit is “%/μm”, the same hereinafter), which is the shear creep value per 1 μm in thickness, with respect to the first pressure-sensitive adhesive reference layer after the strain repeated addition test was performed, the strain repeated addition test was performed The second shear creep rate (R1B), which is the shear creep value per 1 µm in thickness with respect to the first pressure-sensitive adhesive reference layer before the following, and the third shear creep rate, which is the shear creep value per 1 µm in thickness, with respect to the second pressure-sensitive adhesive reference layer after performing the repeated strain addition test (R2A), and the fourth first shear creep rate (R2B), which is the shear creep value per 1 µm in thickness with respect to the second pressure-sensitive adhesive reference layer before performing the strain repeated addition test, were calculated. Then, by subtracting the second shear creep ratio from the first shear creep ratio and the fourth shear creep ratio from the third shear creep ratio, the respective subtracted values were obtained as ?R1 and ?R2.

<Gel fraction of adhesive layer>

The gel fraction of the pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer A11 and the pressure-sensitive adhesive layer A12) was measured according to the following (I) to (V).

(I) A pressure-sensitive adhesive layer having an area of about 8 cm x about 8 cm and a metal mesh (whose mass is Wm) made of SUS 304 of about 10 cm x about 10 cm are bonded together.

(II) Weigh the mass of the bonding material obtained in (I) above, let the mass be Ws, then fold 4 times to cover the pressure-sensitive adhesive layer and fix it with a stapler (stapler), then weigh, and the mass is Wb .

(III) Put the mesh fixed with a stapler in (II) above in a glass container, add 60 mL of ethyl acetate to immerse, and store this glass container at room temperature for 3 days.

(IV) The mesh of said (III) was taken out from the glass container, and after drying at 120 degreeC for 24 hours, it was weighed, and the mass was made into Wa.

(V) By substituting the above-mentioned weighed mass into the formula of gel fraction (mass %) = [wWa-(Wb-Ws)-Wm｝/(Ws-Wm)] x 100, the gel fraction of the pressure-sensitive adhesive layer is Calculated.

[Production of adhesive sheet]

[1] Preparation of adhesive sheet A11

(1) Preparation of (meth)acrylic polymer A

A mixed solution of 81.8 parts by mass of acetone, 98.6 parts by mass of butyl acrylate, 1.0 parts by mass of 2-hydroxyethyl acrylate, and 0.4 parts by mass of acrylic acid is introduced into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and nitrogen gas By replacing the air in the vessel with the furnace, the internal temperature was raised to 55°C without containing oxygen. Then, the whole quantity of the solution which melt|dissolved 0.14 mass parts of azobisisobutyronitrile (polymerization initiator) in 10 mass parts of acetone was added. One hour after the addition of the polymerization initiator, acetone is continuously added into the reaction vessel at an addition rate of 17.3 parts by mass/hr so that the concentration of the acrylic resin excluding the monomer becomes 35 mass%, and the temperature is maintained at 54 to 56° C. for 12 hours, Finally, acetone was added and it adjusted so that the density|concentration of an acrylic resin might be 20 mass %. As for the obtained acrylic resin, the weight average molecular weight Mw of polystyrene conversion by GPC was 1270000. Let this be (meth)acrylic polymer A. The structural unit derived from 2-hydroxyethyl acrylate which is a hydroxyl-containing unsaturated monomer in (meth)acrylic-type polymer A is 1 mass %, and the structural unit derived from acrylic acid which is a carboxy-group-containing unsaturated monomer is 0.4 mass %.

(2) Preparation of adhesive composition A11

100 parts by mass of (meth)acrylic polymer A obtained in the above step (in terms of solid content; as follows), polyisocyanate (manufactured by Tosoh Corporation, product name "Colonate L") as thermal crosslinking agent B and 3 as silane coupling agent C -Glycidoxypropyl trimethoxysilane (the Shin-Etsu Chemical Co., Ltd. make, product name "KBM403") was mixed, and the coating solution of the adhesive composition A11 was obtained by diluting with methyl ethyl ketone while fully stirring. Table 1 shows each compounding|blending (solid content conversion value) of adhesive composition A11 at the time of making a (meth)acrylic-type polymer 100 mass parts (solid content conversion value). "BA" which is an abbreviation in Table 1 shows n-butyl acrylate, "2EHA" shows 2-ethylhexyl acrylate, "AA" shows acrylic acid. The Tg (°C) of these BA, 2EHA, and AA was determined by differential thermal analysis (DTA).

(3) Manufacture of adhesive sheet A11

The coating material was formed by apply|coating the coating solution of the said adhesive composition A11 to the peeling process surface of the 1st peeling film (The Lintec company make, product name "SP-PET752150") with a knife coater. With respect to the said coating material, the coating layer was formed by heat-processing at 90 degreeC for 1 minute. Next, the application layer on the first release film and the second release film (manufactured by Lintec, product name "SP-PET382120") are bonded together so that the release-treated surface of the second release film is in contact with the application layer, and 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 formed using the pressure-sensitive adhesive composition A11, that is, the first release film/the pressure-sensitive adhesive layer (thickness: 25 µm)/the second release The adhesive sheet A11 which consists of a film structure was produced. In a present Example, the adhesive layer of adhesive sheet A11 is also called adhesive layer A11.

[2] Preparation of adhesive sheet A12

(1) Preparation of (meth)acrylic polymer A

The (meth)acrylic polymer A used for manufacture of the said adhesive sheet A11 was prepared.

(2) Preparation of adhesive composition A12

With respect to 100 parts by mass of the (meth)acrylic polymer A, a coating solution of the pressure-sensitive adhesive composition A12 was obtained by making the compounding quantity of the colonate L which is a thermal crosslinking agent as shown in Table 1 similar to the preparation method of the pressure-sensitive adhesive composition A11. .

(3) Manufacture of adhesive sheet A12

Adhesive sheet A12 was produced by making it similar to the manufacturing process of adhesive sheet A11 using the coating solution of the said adhesive composition A12. In a present Example, the adhesive layer of adhesive sheet A12 is also called adhesive layer A12.

In Table 1, each compounding (solid content conversion value) of adhesive composition A12 at the time of making a (meth)acrylic-type polymer 100 mass parts (solid content conversion value) is shown. In Table 1, the value of the gel fraction of the adhesive composition A11 and adhesive composition A12 calculated|required by the method mentioned above was also shown.

[Table 1]

Further, as commercially available pressure-sensitive adhesive sheets, OCA8146-02 and CEF3004 (both manufactured by 3M, USA) were prepared.

[3] Preparation of adhesive sheet B11

(1) Preparation of (meth)acrylic polymer B1

A cooling device was installed in the reaction vessel so that nitrogen gas was refluxed to facilitate temperature control. Into this reaction vessel, the monomer mixture described in Table 2 was charged. Nitrogen gas was purged for 1 hour to remove oxygen. After maintaining the temperature at 60° C. and uniformly mixing the monomer mixture, the photopolymerization initiator shown in Table 2 was added. After stirring, ultraviolet (10mW) was irradiated from a UV lamp to prepare a (meth)acrylic polymer B1.

(2) Preparation of adhesive composition B11

It mixed so that content of the said (meth)acrylic-type polymer B1, an active energy ray polymeric compound, and a photoinitiator might become the ratio of Table 3, and the adhesive composition B11 was manufactured.

(3) Manufacture of adhesive sheet B11

On the release film by which the silicone release process was carried out, adhesive composition B11 was apply|coated so that thickness might be set to 25 micrometers. After laminating|stacking the release film further on the coating film, ultraviolet-ray (accumulated light quantity 400mJ/cm<2>, illuminance 1.8mW/cm<2>, UVV standard) was irradiated, and the adhesive sheet B11 was produced. In a present Example, the adhesive layer of adhesive sheet B11 is also called adhesive layer B11.

[4] Manufacture of adhesive sheet B21

(1) Preparation of (meth)acrylic polymer B2

A cooling device was installed in the reaction vessel so that nitrogen gas was refluxed to facilitate temperature control. Into this reaction vessel, the monomer mixture described in Table 2 was charged. Nitrogen gas was purged for 1 hour to remove oxygen. After maintaining the temperature at 60° C. and uniformly mixing the monomer mixture, the photopolymerization initiator shown in Table 2 was added. After stirring, ultraviolet (10 mW) was irradiated from a UV lamp to prepare (meth)acrylic polymer B2.

(2) Preparation of adhesive composition B21

It mixed so that content of the said (meth)acrylic-type polymer B2, an active energy ray polymeric compound, and a photoinitiator might become the ratio of Table 3, and the adhesive composition B21 was manufactured.

(3) Manufacture of adhesive sheet B21

On the release film by which the silicone release process was carried out, adhesive composition B21 was apply|coated so that thickness might be set to 25 micrometers. After laminating|stacking the release film further on the coating film, ultraviolet-ray (accumulated light quantity 400mJ/cm<2>, illuminance 1.8mW/cm<2>, UVV standard) was irradiated, and the adhesive sheet B21 was produced. In a present Example, the adhesive layer of adhesive sheet B21 is also called adhesive layer B21.

[Table 2]

In Table 2, "LA" as an abbreviation represents lauryl acrylate, "2-EHA" represents 2-ethylhexyl acrylate, "2-HEA" represents 2-hydroxyethyl acrylate, and "2-EHA" represents 2-hydroxyethyl acrylate. PHA" represents 2-propylheptyl acrylate, "C22A" represents behenyl acrylate, and "ODA" represents octyldecyl acrylate.

[Table 3]

"IBOA" which is an abbreviation in Table 3 shows isobornyl acrylate.

With respect to the pressure-sensitive adhesive sheet, according to the method described above, each pressure-sensitive adhesive reference layer having a thickness of 200 μm was prepared, and before and after the repeated deformation addition test was performed on each pressure-sensitive adhesive reference layer as a target, and after the deformation repetition addition test was performed The shear creep value (%) of , and the difference (%/μm) of the shear creep rate were obtained. A result is shown as Table 4. In Table 4, the numerical value of the shear creep rate (%/micrometer) before performing the deformation|transformation repeated addition test in each adhesive reference layer was also shown.

[Table 4]

[Production of laminate]

[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. Material preparation

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 prepared 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>

As the polymerizable liquid crystal compound, 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 prepared.

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

<dichroic dye>

As a 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 prepared.

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 (Kurare 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. That is, 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. That is, first, the composition (A-1) was applied on the first alignment layer (AL1) 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 (OLS3000 manufactured by Olympus Corporation). 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. That is, on the said 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

A solution obtained by dissolving the above-described polymer 1 in cyclopentanone at a concentration of 5% by mass was prepared as a composition for forming an alignment film (composition (D-1)).

3) Composition for forming retardation layer

Each component shown below was mixed, and the composition (B-1) was obtained by 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. That is, 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. The polarization direction of polarization 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. That is, the composition (B-1) is applied by a bar coating method on the second alignment film (AL2) of the laminate composed of the above “base (PET)/second alignment film (AL2)”, and is heated in a drying oven at 120° C. After heating and drying for 1 minute, 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)/phase difference part (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 Chemical Co., Ltd.): 0.5 parts by mass

The said adhesive composition was prepared by adding ethyl acetate so that total solid content concentration might be 10 mass %.

3) Preparation of common adhesive sheet

The pressure-sensitive adhesive composition prepared as described above is applied to the release-treated surface of the release-treated polyethylene terephthalate film (heavy separator, thickness 38 µm) using an applicator so that the thickness after drying becomes 5 µm. got This 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, 38 micrometers in thickness) by which the mold release process was carried out was pasted together. Then, it was made to cure for 7 days on the conditions of temperature 23 degreeC and 50 %RH of relative humidity, and the common adhesive sheet which has the layer structure of light separator/common adhesive layer/medium separator was obtained.

[Backboard]

As the back plate, a PET film having a thickness of 100 µm was prepared.

[Example 1]

The laminated body was manufactured in the procedure shown to Fig.3 (a) - (e). First, as shown to Fig.3 (a), the above-mentioned polarizer layer 410 (TAC film 301/cPL((AL1+pol)302/OC layer 303)) and the above-mentioned common adhesive sheet 420 ) (light separator 304/common pressure-sensitive adhesive layer 305/medium separator 306) was prepared. After performing corona treatment (output 0.3kW, processing speed 3m/min) to the surface which peeled the OC layer 303 side of the said polarizer layer 410, and the light separator 304 of the common adhesive sheet 420, bonding together By doing so, the 1st laminated body precursor 430 shown to FIG.3(b) was obtained. Furthermore, as shown in FIG.3(b), the above-mentioned retardation layer 440 (base material (PET) 308/retardation part (AL2+QWP) 307) was prepared.

Next, corona treatment (output 0.3 kW, processing speed 3 m/min) is performed on the phase difference part 307 side of the phase difference layer 440 and the surface from which the middle separator 306 of the first laminate precursor 430 is peeled off. Then, the 2nd laminated body precursor 450 shown to FIG.3(c) was obtained by bonding together. Then, as shown to FIG.3(c), the said adhesive sheet A11 was prepared as the adhesive sheet 460 (1st peeling film 309 / adhesive layer 310 / 2nd peeling film 311). . The pressure-sensitive adhesive layer 310 of the pressure-sensitive adhesive sheet 460 corresponds to the second pressure-sensitive adhesive layer.

The surface from which the base material (PET) 308 of the 2nd laminated body precursor 450 was peeled and the surface from which the 1st peeling film 309 of the adhesive sheet 460 was peeled were corona-treated (output 0.3kW, processing speed 3m) /min), the 3rd laminated body precursor 470 shown to FIG.3(d) was obtained by bonding together.

Moreover, the said adhesive sheet A12 was prepared as the adhesive sheet 490 (1st peeling film 314 / adhesive layer 315 / 2nd peeling film 316), and the surface from which the 1st peeling film 314 was peeled. And after performing corona treatment (output 0.3kW, processing speed 3m/min) to the polyimide film 313 side of the front plate 480 (polyimide film 313/hard-coat layer 312) mentioned above, bonding together By doing so, the 4th laminated body precursor 500 shown to FIG.3(d) was obtained. The pressure-sensitive adhesive layer 315 of the pressure-sensitive adhesive sheet 490 corresponds to the first pressure-sensitive adhesive layer.

Then, the surface from which the 2nd peeling film 316 of the 4th laminated body precursor 500 was peeled, and the TAC301 side of the 3rd laminated body precursor 470 side corona-treated (output 0.3kW, processing speed 3m) /min), the 6th laminated body precursor 300 shown to FIG.3(e) was obtained by bonding together. Finally, in the sixth laminate precursor 300, the second release film 311 is peeled off, and the peeled side and one side of the PET film having a thickness of 100 μm prepared as a back plate are corona treated (output 0.3 The laminate of Example 1 was obtained by bonding together after implementing kW and processing speed 3 m/min). The laminate of Example 1 has a shape of 240 µm in thickness and 190 mm in length x 150 mm in width.

[Examples 2-5, Comparative Examples 1-2]

By applying the same manufacturing method as the laminate of Example 1 except having used the adhesive sheet which has the adhesive layer shown in Table 5 instead of the adhesive sheets A11 and A12 used in Example 1, Examples 2-5 and The laminates of Comparative Examples 1 and 2 were manufactured.

About the laminated body of Examples 1-5 and Comparative Examples 1-2, the kind of adhesive composition used in order to form a 1st adhesive layer and a 2nd adhesive layer was shown as a list in Table 5. Examples 1 to 5 satisfy the relationship ?R1 > ?R2, and Comparative Examples 1 to 2 satisfy the relationship ?R1 ?R2.

[Table 5]

Moreover, the bending durability test and the surface hardness test were performed by the method mentioned later about the laminated body of Examples 1-5 and Comparative Examples 1-2. A result is shown in Table 6.

<Bending durability test (mandrel test)>

A test piece having a length of 100 mm and a width of 10 mm was cut out from the laminate of each Example and each comparative example using a super cutter. For this test piece, using a bending resistance tester (cylindrical mandrel method) manufactured by TP Kigen Co., Ltd., the test piece was placed around the cylindrical mandrel (mandrel) so that the back plate of the test piece (laminated body) was inside. The bending durability test (mandrel test) in which a test piece was bent along the longitudinal direction at a temperature of 25 degreeC was done so that it may be wound around. Thereby, the minimum diameter of the core bar which does not generate|occur|produce in the adhesive layer of the test piece (laminated body) was calculated|required, and it ranked based on the following criteria. In the bending durability test, it can be evaluated that the bending durability of an adhesive layer is excellent, so that the value of this minimum diameter is small.

A: When it wound around the core rod of (phi) 10 mm or less, foam|bubble generate|occur|produced in the adhesive layer.

B: When it wound around the core rod of more than phi 10 mm and less than phi 15 mm, bubbles were generated in the pressure-sensitive adhesive layer.

C: When it was wound around the core rod of more than (phi) 15 mm and less than (phi) 20 mm, foam|bubble generate|occur|produced in the adhesive layer.

D: When it wound around the core rod exceeding (phi) 20 mm, foam|bubble generate|occur|produced in the adhesive layer.

<Surface hardness test>

For the surface of the back plate in the laminate of each Example and each comparative example, using a pencil hardness tester (PHT, manufactured by SUKBO SCIENCE, Korea), a load of 100 g was applied at a temperature of 25 ° C. With a pencil (manufactured by Mitsubishi Enfits Co., Ltd., the hardness of the core is 6B), concave marks were formed on the surface. In this case, the surface hardness of the laminated body of each Example and each comparative example was evaluated by calculating|requiring the time until the said recessed part disappears, and ranking based on the following criteria. In this surface hardness test, it can be evaluated that it is excellent in surface hardness, so that the time until the recessed part disappears is short.

A: The concave marks disappeared in less than 30 minutes.

B: The concave marks disappeared in 30 minutes or more and less than 60 minutes.

C: Concave marks disappeared in 60 minutes or more and less than 90 minutes.

D: Even if 90 minutes passed, the concave mark did not disappear.

[Table 6]

According to the above, Examples 1 to 5 satisfy the relationship of ΔR1 > ΔR2, and are excellent in evaluation of flexural durability and surface hardness with respect to Comparative Examples 1 and 2, which is a relationship of ΔR1 ≤ ΔR2.

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

Claims (7)

A laminate comprising 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 first pressure-sensitive adhesive reference layer is formed using the first pressure-sensitive adhesive composition so that the thickness of the first pressure-sensitive adhesive reference layer is equal to the thickness of the second pressure-sensitive adhesive reference layer, the second pressure-sensitive adhesive reference layer is formed using the second pressure-sensitive adhesive composition, Wherein the first pressure-sensitive adhesive reference layer and the second pressure-sensitive adhesive reference layer satisfy the relationship of the following formula (1), the laminate.
ΔR1>ΔR2 (1)
[In formula (1), ΔR1 represents a value obtained by subtracting R1B from R1A,
ΔR2 represents a value obtained by subtracting R2B from R2A,
R1A represents the first shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. calculated for the first pressure-sensitive adhesive reference layer after performing the strain repeated addition test,
R1B represents a second shear creep rate (%/μm), which is a shear creep value per 1 μm in thickness at 25° C. obtained for the first pressure-sensitive adhesive reference layer before performing the strain repeated addition test,
R2A represents the third shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. calculated for the second pressure-sensitive adhesive reference layer after performing the strain repeated addition test,
R2B represents the fourth shear creep rate (%/μm), which is the shear creep value per 1 μm in thickness at 25° C. calculated for the second pressure-sensitive adhesive reference layer before performing the strain repeated addition test.] According to claim 1,
The said 4th shear creep rate (%/micrometer) is 0.1 or more and 0.2 or less, The laminated body. 3. The method of claim 1 or 2,
At least one of the said 1st adhesive layer and the said 2nd adhesive layer is the laminated body whose thickness is 20 micrometers or more and 50 micrometers or less. 4. The method according to any one of claims 1 to 3,
A laminate having one or more retardation layers between the polarizer layer and the back plate. 5. The method according to any one of claims 1 to 4,
The back plate is a touch sensor panel, the laminate. A display device comprising the laminate according to any one of claims 1 to 5. 7. The method of claim 6,
A display device capable of being bent with the front plate side facing outward.

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