JP7675545B2 - display body - Google Patents

Description

The present invention relates to a display suitable for use as, for example, a capacitive touch panel.

In recent years, touch panels have come to be used more and more as displays in various mobile electronic devices such as smartphones and tablet terminals. Touch panel types include resistive and capacitive types, but the capacitive type is primarily used in such mobile electronic devices.

Recently, efforts have been made to enlarge touch panels, and mesh-shaped metal electrodes, such as copper or silver electrodes, have been considered as electrode materials for such touch panels. However, when conventional adhesives are used in contact with metal electrodes, particularly copper or silver electrodes, ion migration (electrochemical migration; hereafter simply referred to as "migration") can occur. Specifically, the electrode can dissolve and break at the positive electrode, and dendrites can form at the negative electrode due to precipitation of positive electrode components, causing a short circuit.

This type of migration is particularly likely to occur when a voltage is applied to the electrodes under high temperature and humidity conditions. When this type of migration occurs, the resistance value changes and the touch panel will no longer operate normally. In recent years, as electrodes have become finer and narrower in pitch, electrode disconnections and short circuits due to migration have become more likely to occur, and it is desirable to fully prevent and suppress migration.

Incidentally, Patent Document 1 discloses an adhesive composition for touch panels that contains a benzotriazole compound as a rust inhibitor.

JP 2014-177611 A

However, even though benzotriazole compounds as rust inhibitors have the effect of preventing corrosion of metal wiring, they are unable to sufficiently prevent or suppress migration.

The present invention was made in consideration of the above-mentioned circumstances, and aims to provide a display that can effectively prevent and suppress migration.

In order to achieve the above-mentioned object, first, the present invention provides a display comprising a first display member, a second display member, and an adhesive layer for bonding the first display member and the second display member to each other, wherein the first display member and/or the second display member have wiring made of metal or metal oxide on at least the surface to be bonded, the adhesive layer is made of an adhesive containing a rust inhibitor, and the coverage calculated by dividing the adhesive volume ( ^μm3 ) per ^mm2 in a planar view of the adhesive layer by the wiring volume ( ^μm3 ) per ^mm2 in a planar view of the wiring is 200 or more (Invention 1).

In the display body of the above invention (Invention 1), even if the first display body component and/or the second display body component have wiring made of metal or metal oxide at least on the surface to be bonded, the adhesive layer is made of an adhesive containing a rust inhibitor, and the coverage calculated by dividing the adhesive volume ( ^μm3 ) per ^mm2 in plan view of the adhesive layer by the wiring volume ( ^μm3 ) per ^mm2 in plan view of the wiring is 200 or more, so that the adhesive layer with the rust inhibitor segregated on the surface can sufficiently cover the wiring. This makes it easier for the rust inhibitor to effectively exert its effect, and migration can be effectively prevented and suppressed.

In the above invention (Invention 1), when the content of the rust inhibitor in the pressure-sensitive adhesive is α mass % and the thickness of the pressure-sensitive adhesive layer is Z μm, it is preferable that the following formula is satisfied (Invention 2).
0.5<α×Z≦100

In the above inventions (Inventions 1 and 2), it is preferable that the content of the rust inhibitor in the adhesive is 0.001% by mass or more and 1% by mass or less (Invention 3).

In the above inventions (Inventions 1 to 3), it is preferable that the rust inhibitor is an azole (Invention 4).

In the above inventions (Inventions 1 to 4), it is preferable that the adhesive is an acrylic adhesive (Invention 5).

The display according to the present invention can effectively prevent and suppress migration.

1 is a cross-sectional view of an example of the configuration of an adhesive sheet that can be used to manufacture a display according to one embodiment of the present invention. 1 is a cross-sectional view showing a display (touch panel) according to one embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described.
The display according to the present embodiment includes a first display member, a second display member, and an adhesive layer for bonding the first display member and the second display member to each other. The adhesive layer is made of an adhesive containing a rust inhibitor. Here, the first display member and/or the second display member has wiring made of metal or metal oxide on at least the side to be bonded (adhesive layer side). The coverage (hereinafter, sometimes simply referred to as "coverage") calculated by dividing the adhesive volume (μm ³ ) per mm ² in plan view of the adhesive layer by the wiring volume (μm ³ ) per mm ² in plan view of the wiring is preferably 200 or more.

In the display according to this embodiment, the wiring made of metal or metal oxide is prevented or suppressed from dissolving at the positive electrode, and the formation of dendrites at the negative electrode is prevented or suppressed. That is, migration in the electrodes is effectively prevented or suppressed (this effect is sometimes referred to as the "migration prevention effect"), and changes in the resistance value of the electrodes can be suppressed. Furthermore, by effectively preventing or suppressing migration, even if the first display component and/or the second display component have wiring that is finer and has a narrower pitch, for example, disconnection or short circuit of the wiring is prevented. In particular, when the above wiring is an electrode of a touch panel, driving failure of the touch panel caused by disconnection or short circuit is prevented.

The reason why the above effect occurs is not clear, but is presumed to be as follows. The adhesive layer of the display according to this embodiment is composed of an adhesive containing a rust inhibitor. The rust inhibitor tends to segregate on the surface of the adhesive layer. And, since the coverage is within the above range, the adhesive layer with the rust inhibitor segregated on the surface can sufficiently cover the wiring made of metal or metal oxide. It is presumed that this makes it easier for the rust inhibitor to effectively exert its action and can exhibit an excellent migration prevention effect. In addition, it is considered that by sufficiently covering the wiring made of metal or metal oxide with the adhesive layer with the rust inhibitor segregated on the surface, the coordination part such as the diamino group in the rust inhibitor forms a chelate compound by coordination bonding with the metal atom of the wiring, forming an anti-rust coating. Migration is likely to occur when moisture penetrates the electrode, but the formation of the coating suppresses the penetration of moisture, and it is presumed that the display according to this embodiment can exhibit an excellent migration prevention effect.

Here, in a display body in which the wiring is made finer and narrower in pitch, the distance between the wirings (hereinafter sometimes referred to as the "distance between wirings") is short, so the contact area of the adhesive layer with the wirings is large. If the contact area is large, the rust inhibitor is used more to form an anti-rust coating by the above-mentioned coordinate bond, and it is thought that the problem of the concentration of the rust inhibitor near the wirings being easily reduced occurs. In particular, since the rust inhibitor concentration in the adhesive between the wirings is easily low, moisture tends to penetrate and accumulate, and it is thought that the supply of the rust inhibitor from the adhesive above the wiring to the adhesive between the wirings tends to be hindered. In this way, it is presumed that migration is more likely to occur if the concentration of the rust inhibitor near the wirings is partially low. In the display body according to this embodiment, the adhesive layer is made of an adhesive containing a rust inhibitor, and the coverage is as described above, so that the above problem caused by the wiring being made finer and narrower in pitch can be solved. Specifically, by increasing the total amount of rust inhibitor contained in the adhesive layer, the rust inhibitor is continuously supplied from the adhesive on top of the wiring to the adhesive between the wiring, and the decrease in the rust inhibitor concentration in the adhesive between the wiring can be suppressed. This makes it possible to maintain a uniform concentration of the rust inhibitor near the wiring. As a result, it is believed that the rust inhibitor's action is more effectively exerted, and excellent migration prevention effects can be achieved.

In this specification, the coverage is calculated as follows.
First, the wiring volume (μm ³ ) per 1 mm ² (1000 μm×1000 μm) in plan view of wiring made of metal or metal oxide is calculated as follows. In wiring made of metal or metal oxide, the wiring width is A (μm), the distance between wirings is B (μm), and the wiring thickness is C (μm). The wiring length in the direction perpendicular to the wiring width and the distance between wirings is 1000 μm. In this case, the wiring volume per wiring is
Aμm×Cμm×1000μm (μm ³ )
The number of wires per 1 mm (1000 μm) in the wire width direction (wire-to-wire distance direction) is given by
1000μm/(A+B) (pieces)
The number of wires is rounded down to the nearest integer.
Therefore, the wiring volume (μm ³ ) per 1 mm ² in plan view of the wiring is calculated by the following formula (1).
Volume of one wire {A μm×C μm×1000}×number of wires {1000 μm/(A+B)} (1)
Next, the pressure-sensitive adhesive volume (μm ³ ) per 1 mm ² (1000 μm×1000 μm) in plan view of the pressure-sensitive adhesive layer is calculated by the following formula (2), where the thickness of the pressure-sensitive adhesive layer is Z μm.
Z μm x 1000 μm x 1000 μm (μm ³ )...(2)
Although the wiring is embedded in the adhesive layer, the volume of the wiring is very small compared to the volume of the adhesive, so the adhesive volume (μm ³ ) in calculating the coverage is the value of formula (2) above.
The value obtained by dividing (2) by (1) was determined as the degree of coverage.

The degree of coverage is preferably 200 or more, more preferably 250 or more, particularly preferably 300 or more, and even more preferably 330 or more. The upper limit of the degree of coverage is not particularly limited, but is preferably 10,000 or less, more preferably 5,000 or less, particularly preferably 2,000 or less, and even more preferably 1,500 or less. In particular, from the viewpoint of being able to exert an excellent migration prevention effect even in the case of finer and narrower pitch wiring, it is preferably 1,200 or less, more preferably 1,000 or less, and from the viewpoint of being able to exert an excellent migration prevention effect even in the case of a thin adhesive layer, it is particularly preferably 800 or less, even more preferably 600 or less, and most preferably 500 or less. By having the degree of coverage within the above range, the adhesive layer with the rust inhibitor segregated on the surface layer can sufficiently cover the wiring. In addition, the rust inhibitor is continuously supplied from the adhesive on the top of the wiring to the adhesive between the wiring, and the concentration of the rust inhibitor near the wiring can be maintained uniformly. This allows the rust inhibitor to more effectively exert its effect, providing excellent migration prevention effects and effectively suppressing changes in the resistance value of the electrode. Furthermore, by maintaining a uniform concentration of the rust inhibitor near the wiring, the formation of a coating by the rust inhibitor is maintained over time, and color changes in the wiring and adhesive layer can be suppressed.

The adhesive layer of the display according to this embodiment can be preferably formed from an adhesive layer of an adhesive sheet, which will be described below. However, the present invention is not limited to this as long as it satisfies the above-mentioned physical properties.

[Adhesive sheet]
One example of an adhesive sheet capable of producing a display according to one embodiment of the present invention comprises a first display component, a second display component, and an adhesive layer for bonding the first display component and the second display component to each other, and preferably has a release sheet laminated to one or both sides of the adhesive layer.

A specific structure of an example of an adhesive sheet that can be used to manufacture a display according to this embodiment is shown in FIG. 1. As shown in FIG. 1, the adhesive sheet 1 is composed of two release sheets 12a, 12b and an adhesive layer 11 sandwiched between the two release sheets 12a, 12b so as to contact the release surfaces of the two release sheets 12a, 12b. However, the release sheets 12a, 12b are not essential components of the adhesive sheet 1, and are peeled off and removed when the adhesive sheet 1 is used. In this specification, the release surface of the release sheet refers to the surface of the release sheet that has releasability, and includes both a surface that has been subjected to a release treatment and a surface that exhibits releasability even without a release treatment.

1. Each component 1-1. Adhesive layer The adhesive constituting the adhesive layer 11 of the adhesive sheet 1 is not particularly limited as long as it contains a rust inhibitor. The type of adhesive may be, for example, any of an acrylic adhesive, a polyester adhesive, a polyurethane adhesive, a rubber adhesive, a silicone adhesive, etc. In addition, the adhesive may be any of an emulsion type, a solvent type, or a solventless type, and may be any of a crosslinked type or a non-crosslinked type. Among them, an acrylic adhesive, which has excellent adhesive properties, optical properties, etc., is preferred.

Specifically, the above-mentioned adhesive is preferably obtained from an adhesive composition (hereinafter sometimes referred to as "adhesive composition P") containing a (meth)acrylic acid ester polymer (A) and a rust inhibitor (B), and is particularly preferably obtained by crosslinking an adhesive composition containing a (meth)acrylic acid ester polymer (A), a rust inhibitor (B), and a crosslinking agent (C), and is further preferably obtained by crosslinking an adhesive composition containing a (meth)acrylic acid ester polymer (A), a rust inhibitor (B), a crosslinking agent (C), and a silane compound (D). In this specification, (meth)acrylic acid ester means both acrylic acid ester and methacrylic acid ester. The same applies to other similar terms. In addition, the concept of "copolymer" is also included in "polymer".

The adhesive obtained from the adhesive composition P may be an active energy ray curable adhesive that is cured by irradiation with active energy rays, or an active energy ray non-curable adhesive that is not cured by irradiation with active energy rays. In the case of an active energy ray curable adhesive, it is preferable that the adhesive composition P further contains an active energy ray curable component (E).

(1) Components of the Pressure-Sensitive Adhesive Composition (1-1) (Meth)acrylic Acid Ester Polymer (A)
The (meth)acrylic acid ester polymer (A) preferably contains a reactive functional group-containing monomer having a reactive functional group in the molecule as a monomer constituting the polymer. By containing this reactive functional group-containing monomer, it reacts with the crosslinking agent (C) described later through the reactive functional group derived from the reactive functional group-containing monomer, thereby forming a crosslinked structure (three-dimensional network structure), and a pressure-sensitive adhesive having a predetermined cohesive strength is obtained.

Preferable examples of reactive functional group-containing monomers contained in the (meth)acrylic acid ester polymer (A) as monomer units constituting the polymer include monomers having a hydroxyl group in the molecule (hydroxyl group-containing monomers), monomers having a carboxyl group in the molecule (carboxyl group-containing monomers), and monomers having an amino group in the molecule (amino group-containing monomers). These reactive functional group-containing monomers may be used alone or in combination of two or more.

Among the above reactive functional group-containing monomers, hydroxyl group-containing monomers that have excellent reactivity with the crosslinking agent (C) and have little adverse effect on the electrodes are particularly preferred.

Examples of hydroxyl group-containing monomers include (meth)acrylic acid hydroxyalkyl esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Among these, from the viewpoint of reactivity with the crosslinking agent (C), 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred, 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate are more preferred, and 2-hydroxyethyl acrylate is particularly preferred. These may be used alone or in combination of two or more.

The (meth)acrylic acid ester polymer (A) preferably contains 6% by mass or more of reactive functional group-containing monomers (particularly hydroxyl group-containing monomers) as monomer units constituting the polymer, more preferably 9% by mass or more, particularly preferably 12% by mass or more, and even more preferably 15% by mass or more. In the case of fine and narrow-pitched wiring or when the thickness of the adhesive layer is thin, the effect of the rust inhibitor (B) described later is more easily exhibited, so it is preferable to contain 18% by mass or more, particularly preferably 20% by mass or more. In addition, the (meth)acrylic acid ester polymer (A) preferably contains 35% by mass or less of reactive functional group-containing monomers (particularly hydroxyl group-containing monomers) as monomer units constituting the polymer, particularly preferably 30% by mass or less, and even more preferably 25% by mass or less.

When the (meth)acrylic acid ester polymer (A) contains the reactive functional group-containing monomer as a monomer unit in the above amount, the adhesive strength and cohesive strength of the resulting adhesive are well balanced. In particular, when the reactive functional group-containing monomer is a hydroxyl group-containing monomer, when the (meth)acrylic acid ester polymer (A) contains the hydroxyl group-containing monomer as a monomer unit in the above amount, a predetermined amount of hydroxyl groups, which are hydrophilic groups, remain in the resulting adhesive. As a result, even if moisture is present, the moisture is captured by the hydroxyl groups. In particular, the hydroxyl groups contained in the adhesive on the upper part of the wiring capture moisture, and it is possible to prevent moisture from accumulating in the adhesive between the wiring. This prevents moisture from penetrating into the electrode adjacent to the adhesive layer. Furthermore, the supply of the rust inhibitor from the adhesive on the upper part of the wiring to the adhesive between the wiring is less likely to be hindered, making it easier to maintain a uniform concentration of the rust inhibitor near the wiring. As a result, an excellent migration prevention effect can be achieved.

It is preferable that the (meth)acrylic acid ester polymer (A) does not contain a carboxyl group-containing monomer as a monomer unit constituting the polymer. Since the carboxyl group is an acid component, there is a concern that the resistance value change due to corrosion of the electrode with which the adhesive comes into contact may occur. However, by not containing a carboxyl group-containing monomer, corrosion of the electrode can be prevented and the resistance value change can be effectively prevented or suppressed. However, the above-mentioned "not containing a carboxyl group-containing monomer" means that the carboxyl group-containing monomer is allowed to be contained to an extent that the electrode with which the obtained adhesive comes into contact is not adversely affected. Specifically, it is allowed that the (meth)acrylic acid ester polymer (A) contains a carboxyl group-containing monomer as a monomer unit in an amount of 0.1 mass% or less, preferably 0.01 mass% or less, and more preferably 0.001 mass% or less.

In addition, it is preferable that the (meth)acrylic acid ester polymer (A) contains an alkyl (meth)acrylic acid ester as a monomer unit constituting the polymer. This allows the polymer to exhibit good adhesion.

In particular, the (meth)acrylic acid ester polymer (A) preferably contains, as monomer units constituting the polymer, in addition to the reactive functional group-containing monomer described above, a (meth)acrylic acid alkyl ester having an alkyl group carbon number of 2 to 20 and a glass transition temperature (Tg) of 0°C or less as a homopolymer, and a monomer having a glass transition temperature (Tg) of more than 0°C as a homopolymer.

The (meth)acrylic acid ester polymer (A) can exhibit favorable adhesion by containing, as a monomer unit constituting the polymer, a (meth)acrylic acid alkyl ester (hereinafter sometimes referred to as "low Tg alkyl acrylate") having a glass transition temperature (Tg) of 0°C or less as a homopolymer and having 2 to 20 carbon atoms in the alkyl group. From this viewpoint, the (meth)acrylic acid ester polymer (A) preferably contains 30% by mass or more of low Tg alkyl acrylate as a monomer unit constituting the polymer, more preferably 40% by mass or more, particularly preferably 50% by mass or more, and even more preferably 60% by mass or more. In addition, the (meth)acrylic acid ester polymer (A) preferably contains the above-mentioned low Tg alkyl acrylate as a monomer unit constituting the polymer in an upper limit of 90% by mass or less, particularly preferably 80% by mass or less, and even more preferably 70% by mass or less. When the upper limit of the content of the low Tg alkyl acrylate is as described above, other monomer components can be introduced into the (meth)acrylic acid ester polymer (A) in suitable amounts.

Preferred examples of low Tg alkyl acrylates include ethyl acrylate (Tg -20°C), n-butyl acrylate (Tg -55°C), isobutyl acrylate (Tg -26°C), n-octyl acrylate (Tg -65°C), isooctyl acrylate (Tg -58°C), 2-ethylhexyl acrylate (Tg -70°C), 2-ethylhexyl methacrylate (Tg -10°C), isononyl acrylate (Tg -58°C), isodecyl acrylate (Tg -60°C), isodecyl methacrylate (Tg -41°C), n-lauryl acrylate (Tg -23°C), n-lauryl methacrylate (Tg -65°C), tridecyl acrylate (Tg -55°C), tridecyl methacrylate (-40°C), and isostearyl acrylate (Tg -18°C). Among them, from the viewpoint of more effectively imparting adhesion as a low Tg alkyl acrylate, it is more preferable that the Tg of the homopolymer is −40° C. or less, and particularly preferable that it is −50° C. or less. Specifically, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferable, and from the viewpoint of effectively suppressing migration, 2-ethylhexyl acrylate is even more preferable. These may be used alone or in combination of two or more kinds. The alkyl group in the (meth)acrylic acid alkyl ester having 2 to 20 carbon atoms in the alkyl group refers to a linear, branched, or cyclic alkyl group.

In addition, from the viewpoint of effectively suppressing migration by improving the hydrophobicity of the resulting pressure-sensitive adhesive layer, at least a portion of the low Tg alkyl acrylate is preferably a (meth)acrylic acid alkyl ester having 5 or more carbon atoms in the alkyl group, and more preferably a (meth)acrylic acid alkyl ester having 7 or more carbon atoms in the alkyl group. Specifically, 2-ethylhexyl acrylate is particularly preferred. In addition, from the viewpoint of effectively suppressing migration, the proportion of (meth)acrylic acid alkyl ester having 5 or more carbon atoms in the alkyl group (preferably 7 or more) in the entire low Tg alkyl acrylate is preferably 40% by mass or more, more preferably 60% by mass or more, particularly preferably 80% by mass or more, and most preferably 100% by mass.

In addition, the (meth)acrylic acid ester polymer (A) contains, as a monomer unit constituting the polymer, a monomer (hereinafter sometimes referred to as a "hard monomer") having a glass transition temperature (Tg) of more than 0°C as a homopolymer, so that the resulting adhesive tends to have appropriate cohesive strength and adhesiveness. As a result, the resulting adhesive layer tends to suppress defects such as lifting and peeling at the interface with the adherend even after durability conditions.

Examples of the hard monomers include methyl acrylate (Tg 10°C), methyl methacrylate (Tg 105°C), ethyl methacrylate (Tg 65°C), n-butyl methacrylate (Tg 20°C), isobutyl methacrylate (Tg 48°C), t-butyl methacrylate (Tg 107°C), n-stearyl acrylate (Tg 30°C), n-stearyl methacrylate (Tg 38°C), cyclohexyl acrylate (Tg 15°C), cyclohexyl methacrylate (Tg 66°C), phenoxyethyl acrylate (Tg 5°C), and phenoxyethyl methacrylate. Preferred examples of the monomers include acrylic monomers such as acrylate (Tg 54°C), benzyl methacrylate (Tg 54°C), isobornyl acrylate (Tg 94°C), isobornyl methacrylate (Tg 180°C), acryloylmorpholine (Tg 145°C), adamantyl acrylate (Tg 115°C), adamantyl methacrylate (Tg 141°C), dimethylacrylamide (Tg 89°C), acrylamide (Tg 165°C), vinyl acetate (Tg 32°C), and styrene (Tg 80°C). From the viewpoint of compatibility, acrylic monomers are more preferred. These may be used alone or in combination of two or more.

In particular, from the viewpoint of imparting suitable cohesive strength and adhesiveness to the resulting pressure-sensitive adhesive and effectively suppressing defects such as lifting and peeling at the interface with the adherend, the glass transition temperature (Tg) of the hard monomer is more preferably 60°C or higher, and particularly preferably 90°C or higher. In addition, taking into consideration compatibility and copolymerizability with other monomers constituting the (meth)acrylic acid ester polymer (A), the glass transition temperature (Tg) of the hard monomer is preferably 250°C or lower, more preferably 200°C or lower, and particularly preferably 150°C or lower.

Among the above hard monomers, it is preferable to contain at least one selected from the group consisting of methyl methacrylate, isobornyl acrylate, and acryloylmorpholine, from the viewpoint of better exerting the performance of the hard monomer while preventing adverse effects on other properties such as compatibility with other components. In particular, it is preferable to use methyl methacrylate alone, or to use isobornyl acrylate in combination with acryloylmorpholine.

From the viewpoint of imparting suitable cohesive strength and adhesiveness to the resulting adhesive, the hard monomer is preferably contained in the (meth)acrylic acid ester polymer (A) in an amount of 5% by mass or more as a monomer constituting the polymer, more preferably 10% by mass or more, and particularly preferably 15% by mass or more.

In addition, from the viewpoint of ensuring excellent compatibility between the resulting (meth)acrylic acid ester polymer (A) and other components, the hard monomer is preferably contained in an amount of 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less, as a monomer constituting the polymer.

If desired, the (meth)acrylic acid ester polymer (A) may contain other monomers as monomer units constituting the polymer. As the other monomer, a monomer that does not contain a reactive functional group is preferable so as not to interfere with the action of the reactive functional group-containing monomer. Examples of such other monomers include (meth)acrylic acid alkoxyalkyl esters such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate. These may be used alone or in combination of two or more.

The (meth)acrylic acid ester polymer (A) is preferably a solution polymer obtained by a solution polymerization method. By using a solution polymer, it is easy to obtain a high molecular weight polymer, and an adhesive with excellent durability is obtained. In addition, even in the case of fine and narrow-pitch wiring or when the thickness of the adhesive layer is thin, it is easy to obtain an adhesive that can more easily exhibit the effects of the rust inhibitor (B) described below.

The polymerization form of the (meth)acrylic acid ester polymer (A) may be a random copolymer or a block copolymer.

The lower limit of the weight average molecular weight of the (meth)acrylic acid ester polymer (A) is preferably 200,000 or more, more preferably 450,000 or more, and particularly preferably 550,000 or more, and from the viewpoint of suppressing changes in the resistance value of the electrode and suppressing changes in the color of the wiring and the adhesive layer, it is even more preferable that it is 650,000 or more. When the lower limit of the weight average molecular weight of the (meth)acrylic acid ester polymer (A) is as above, the obtained adhesive has excellent durability and the rust inhibitor (B) is easily segregated on the surface of the adhesive layer. Note that the weight average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

The upper limit of the weight average molecular weight of the (meth)acrylic acid ester polymer (A) is preferably 2,000,000 or less, more preferably 1,500,000 or less, and even more preferably 1,000,000 or less. When the upper limit of the weight average molecular weight of the (meth)acrylic acid ester polymer (A) is as above, the resulting adhesive exhibits suitable adhesive properties.

In addition, in the adhesive composition P, the (meth)acrylic acid ester polymer (A) may be used alone or in combination of two or more kinds.

(1-2) Rust inhibitor (B)
The rust inhibitor (B) in this embodiment is preferably one that segregates favorably on the surface of the adhesive layer. Such rust inhibitor (B) is likely to be present stably on the surface of the adhesive layer, and can effectively exert its action to contribute to the migration prevention effect. Examples of such rust inhibitor (B) include azoles such as azole compounds, triazole compounds, benzotriazole compounds, thiazole compounds, benzothiazole compounds, imidazole compounds, and benzimidazole compounds, as well as phosphorus compounds and nitrite compounds. Among these, azoles are preferred, and benzotriazole compounds are particularly preferred, from the viewpoint of favorable segregation on the surface of the adhesive layer and superior migration prevention effect. The rust inhibitor (B) may be used alone or in combination of two or more kinds.

Examples of benzotriazole compounds include 1H-benzotriazole, 1H-tolyltriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole, carboxybenzotriazole, 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol, etc. Among these, 1H-benzotriazole, 1H-tolyltriazole, 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole and 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole are preferred, and 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole is particularly preferred. This makes it possible to more effectively suppress the occurrence of migration.

The content of the rust inhibitor (B) in the adhesive composition P is preferably 0.001 parts by mass or more, more preferably 0.002 parts by mass or more, particularly preferably 0.006 parts by mass or more, even more preferably 0.008 parts by mass or more, and most preferably 0.01 parts by mass or more, per 100 parts by mass of the (meth)acrylic acid ester polymer (A). This makes it easier for the rust inhibitor (B) to segregate appropriately on the surface layer of the resulting adhesive layer, resulting in a more excellent migration prevention effect.

The content of the rust inhibitor (B) in the adhesive composition P is preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, relative to 100 parts by mass of the (meth)acrylic acid ester polymer (A). From the viewpoint of suppressing the change in the resistance value, it is particularly preferable that it is 0.1 parts by mass or less, more preferably 0.06 parts by mass or less, and most preferably 0.02 parts by mass or less. By having the above content of the rust inhibitor (B), it becomes easier to exhibit an excellent migration prevention effect in combination with the above-mentioned coverage. In addition, since the difference between the concentration of the rust inhibitor (B) in the adhesive on the top of the wiring and the concentration of the rust inhibitor (B) in the adhesive between the wiring is suppressed from becoming extremely large, the concentration of the rust inhibitor (B) in the vicinity of the wiring can be made uniform. This makes it possible to exhibit a good migration prevention effect. In addition, good adhesion is maintained. Furthermore, since the absolute amount of the rust inhibitor (B) contained in the adhesive layer can be suppressed, the color change of the wiring caused by the rust inhibitor (B) can be suppressed.

When the content of the rust inhibitor (B) in the adhesive constituting the adhesive layer in the display according to this embodiment is α mass % and the thickness of the adhesive layer is Z μm, it is preferable that the value satisfies the following formula.
0.5<α×Z≦100
By the value of α×Z being within the above range, it becomes easy to exert an excellent migration prevention effect in combination with the above-mentioned coverage. In addition, even in the case of wiring that is finely divided and has a narrow pitch, the rust inhibitor is continuously supplied from the adhesive on the top of the wiring to the adhesive between the wiring, so that the concentration of the rust inhibitor near the wiring can be easily maintained uniformly. This makes it possible to exert a more excellent migration prevention effect, and the film formation by the rust inhibitor is maintained over time, and color changes in the wiring and the adhesive layer can be suppressed. In addition, the thickness of the adhesive layer 11 in this specification is a value measured in accordance with JIS K7130.

From the above viewpoints, the lower limit of α×Z is preferably 0.6 or more, more preferably 0.7 or more, and even more preferably 0.75 or more. The upper limit of α×Z is preferably 50 or less, and even more preferably 25 or less, and from the viewpoints of suppressing resistance value changes and suppressing color changes in the wiring, it is preferably 20 or less, more preferably 10 or less, and even more preferably 5 or less, even more preferably 3 or less, and most preferably 2.5 or less.

The content of the rust inhibitor (B) in the adhesive constituting the adhesive layer in the display according to this embodiment is preferably 0.001% by mass or more, more preferably 0.002% by mass or more, particularly preferably 0.005% by mass or more, even more preferably 0.008% by mass or more, and most preferably 0.009% by mass or more. This makes it easier for the rust inhibitor (B) to segregate appropriately on the surface layer of the resulting adhesive layer, resulting in a more excellent migration prevention effect.

In addition, the content of the rust inhibitor (B) in the adhesive is preferably 1% by mass or less, more preferably 0.5% by mass or less, particularly preferably 0.1% by mass or less, further preferably 0.06% by mass or less, and most preferably 0.02% by mass or less. This, in combination with the above-mentioned coverage, makes it easier to exhibit an excellent migration prevention effect. In addition, the difference between the rust inhibitor (B) concentration of the adhesive on the top of the wiring and the rust inhibitor (B) concentration of the adhesive between the wiring is suppressed from becoming extremely large, and as a result, the concentration of the rust inhibitor (B) near the wiring can be made uniform. This allows a good migration prevention effect to be exhibited. In addition, good adhesion is maintained. Furthermore, the absolute amount of the rust inhibitor (B) contained in the adhesive layer can be suppressed, so that the color change of the wiring caused by the rust inhibitor (B) can be suppressed.

(1-3) Crosslinking agent (C)
The pressure-sensitive adhesive composition P preferably contains a crosslinking agent (C). By containing the crosslinking agent (C), the pressure-sensitive adhesive composition P can crosslink the (meth)acrylic acid ester polymer (A) to form a three-dimensional network structure, thereby improving the cohesive strength of the resulting pressure-sensitive adhesive and improving its durability.

The crosslinking agent (C) may be any that reacts with the reactive group of the (meth)acrylic acid ester polymer (A), and examples thereof include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, melamine-based crosslinking agents, aziridine-based crosslinking agents, hydrazine-based crosslinking agents, aldehyde-based crosslinking agents, oxazoline-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, and ammonium salt-based crosslinking agents. When the (meth)acrylic acid ester polymer (A) contains a hydroxyl group-containing monomer as a monomer unit constituting the polymer, it is preferable to use an isocyanate-based crosslinking agent that has excellent reactivity with the hydroxyl group. The crosslinking agent (C) may be used alone or in combination of two or more.

The isocyanate-based crosslinking agent contains at least a polyisocyanate compound. Examples of polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate and hydrogenated diphenylmethane diisocyanate, and their biurets, isocyanurates, and adducts which are reactants with low-molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Among these, trimethylolpropane-modified aromatic polyisocyanates, and particularly trimethylolpropane-modified tolylene diisocyanate, are preferred from the viewpoint of reactivity with hydroxyl groups.

The content of the crosslinking agent (C) in the adhesive composition P is preferably 0.001 parts by mass or more, more preferably 0.1 parts by mass or more, particularly preferably 0.2 parts by mass or more, and even more preferably 0.25 parts by mass or more, relative to 100 parts by mass of the (meth)acrylic acid ester polymer (A). The content is preferably 10 parts by mass or less, more preferably 1 part by mass or less, particularly preferably 0.6 parts by mass or less, and even more preferably 0.4 parts by mass or less from the viewpoint of suppressing resistance value change. By having the content of the crosslinking agent (C) in the above range, the cohesive force of the resulting adhesive becomes favorable, and an adhesive with superior adhesion can be obtained.

(1-4) Silane compound (D)
The adhesive composition P preferably contains a silane compound (D). By containing the silane compound (D), the adhesive composition P has a more excellent migration prevention effect.

The silane compound (D) is preferably an organosilicon compound having at least one alkoxysilyl group. This improves the adhesion of the resulting adhesive layer to the display component, which is the adherend, and provides more favorable adhesive strength. In addition, the action of the alkoxysilyl group is thought to prevent moisture from penetrating the electrode adjacent to the resulting adhesive layer, resulting in a more excellent migration prevention effect.

The organosilicon compound having at least one alkoxysilyl group as the silane compound (D) may be, for example, a silane coupling agent. Specific examples include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacryloxypropyltrimethoxysilane; silicon compounds having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyldimethylsilane. mercapto group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane; amino group-containing silicon compounds such as 3-chloropropyltrimethoxysilane, 3-isocyanatepropyltriethoxysilane, or condensates of at least one of these with alkyl group-containing silicon compounds such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, and ethyltrimethoxysilane. These may be used alone or in combination of two or more. Among them, silicon compounds having an epoxy structure are preferred from the viewpoint of migration prevention effect and adhesion, and 3-glycidyloxypropyltrimethoxysilane is particularly preferred.

（式中のＲ^１は、窒素原子を有していてもよい２価の炭化水素基である。式中のＲ^２～Ｒ^７は、それぞれ独立してアルキル基である。） The silane compound (D) may be an organosilicon compound having alkoxysilyl groups at both ends, preferably a compound represented by the following general formula (I):

(In the formula, R ¹ is a divalent hydrocarbon group which may have a nitrogen atom. In the formula, R ² to R ⁷ are each independently an alkyl group.)

From the viewpoint of migration prevention effect, the carbon number of the divalent hydrocarbon group of ^R1 is preferably 1 to 10, particularly preferably 3 to 8, and more preferably 5 to 7. The hydrocarbon group is preferably a saturated hydrocarbon group, and more preferably a chain saturated hydrocarbon group. Furthermore, the hydrocarbon group preferably contains an alkylene group, and more preferably is an alkylene group. The carbon number of the alkylene group is preferably 1 to 10, particularly preferably 3 to 8, and more preferably 5 to 7.

When ^R1 has a nitrogen atom, the nitrogen atom may be present in a side chain of the hydrocarbon group, but is preferably present in the main chain of the hydrocarbon group. When ^R1 has a nitrogen atom, the number of nitrogen atoms contained in ^R1 is preferably 1 to 5, and more preferably 2 to 3. The nitrogen atom is preferably an amino group or an amide group, and more preferably an amino group, and further preferably present in the main chain of the hydrocarbon group as a secondary amine or tertiary amine.

When R ¹ has a nitrogen atom, R ¹ preferably contains a -(CH) _m -NH- skeleton, more preferably contains a -(CH) _m -NH-(CH) _n - skeleton, particularly preferably contains a -(CH) _m -NH-(CH) _n -NH- skeleton, and further preferably contains a -(CH) _m -NH-(CH) _n -NH-(CH) _p - skeleton. The above m, n and p are positive integers, preferably 1 to 5, particularly preferably 2 to 4.

It is preferable that the R ¹ does not have a sulfur atom in the main chain. If the main chain has a sulfur atom, metal sulfide is easily generated at the interface between the adhesive and the wiring made of metal (particularly silver) or metal oxide (particularly ITO) in a durability test environment. This may hinder the migration prevention effect described above.

The number of carbon atoms in the alkyl groups R ² to R ⁷ is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1 or 2. Moreover, it is preferable that all of R ² to R ⁷ are the same alkyl group, and it is most preferable that all of them are methyl groups.

The content of the silane compound (D) in the adhesive composition P is preferably 0.01 parts by mass or more as a lower limit, more preferably 0.1 parts by mass or more, particularly preferably 0.16 parts by mass or more, and even more preferably 0.22 parts by mass or more, relative to 100 parts by mass of the (meth)acrylic acid ester polymer (A). The content is preferably 2 parts by mass or less as an upper limit, particularly preferably 1 part by mass or less, and even more preferably 0.5 parts by mass or less. When the content of the silane compound (D) is in the above range, the action of the silane compound (D) is effectively exerted, and the migration prevention effect is more excellent.

(1-5) Active energy ray-curable component (E)
When the adhesive obtained from the adhesive composition P is an active energy ray curable adhesive, the adhesive composition P preferably contains an active energy ray curable component (E). By containing the active energy ray curable component (E) in the adhesive composition P, the adhesive obtained by crosslinking (thermal crosslinking) the adhesive composition P becomes an active energy ray curable adhesive. In this active energy ray curable adhesive, it is presumed that the active energy ray curable components (E) polymerize with each other by curing by irradiation with active energy rays after attachment to the adherend, and the polymerized active energy ray curable component (E) is entangled with the crosslinked structure (three-dimensional network structure) of the (meth)acrylic acid ester polymer (A). An adhesive having such a high-order structure has high cohesive force and shows high coating strength, and therefore has excellent durability.

The active energy ray-curable component (E) is not particularly limited as long as it is a component that cures when irradiated with active energy rays and can provide the above-mentioned effects, and may be any of a monomer, oligomer, or polymer, or a mixture thereof. Among these, preferred examples include multifunctional acrylate monomers that can provide a pressure-sensitive adhesive with excellent durability.

Examples of polyfunctional acrylate monomers include bifunctional monomers such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, di(acryloxyethyl)isocyanurate, allylated cyclohexyl di(meth)acrylate, ethoxylated bisphenol A diacrylate, and 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene; trifunctional types such as diglycerol tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate; pentafunctional types such as propionic acid-modified dipentaerythritol tri(meth)acrylate; pentafunctional types such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate; and hexafunctional types such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate. Among the above, from the viewpoint of imparting suitable cohesive strength and adhesiveness to the resulting adhesive and effectively suppressing defects such as lifting and peeling at the interface with the adherend, polyfunctional acrylate monomers containing an isocyanurate structure in the molecule, such as di(acryloxyethyl)isocyanurate, tris(acryloxyethyl)isocyanurate, and ε-caprolactone-modified tris-(2-(meth)acryloxyethyl)isocyanurate, are preferred, polyfunctional acrylate monomers that are trifunctional or more and contain an isocyanurate structure in the molecule are more preferred, and ε-caprolactone-modified tris-(2-(meth)acryloxyethyl)isocyanurate is particularly preferred. These may be used alone or in combination of two or more. In addition, from the viewpoint of compatibility with the (meth)acrylic acid ester polymer (A), it is preferable that the polyfunctional acrylate monomer has a molecular weight of less than 1000.

As the active energy ray curable component (E), an active energy ray curable acrylate oligomer can also be used. Examples of such acrylate oligomers include polyester acrylates, epoxy acrylates, urethane acrylates, polyether acrylates, polybutadiene acrylates, silicone acrylates, etc.

The weight average molecular weight of the acrylate oligomer is preferably 50,000 or less, more preferably 1,000 to 50,000, and even more preferably 3,000 to 40,000.

As the active energy ray-curable component (E), an adduct acrylate polymer having a group having a (meth)acryloyl group introduced into the side chain can also be used. Such an adduct acrylate polymer can be obtained by using a copolymer of a (meth)acrylic acid ester and a monomer having a crosslinkable functional group in the molecule, and reacting a compound having a group that reacts with the (meth)acryloyl group and the crosslinkable functional group with a part of the crosslinkable functional group of the copolymer.

The weight average molecular weight of the adduct acrylate polymer is preferably about 50,000 to 900,000, and particularly preferably about 100,000 to 500,000.

The active energy ray curable component (E) may be one selected from the above-mentioned polyfunctional acrylate monomers, acrylate oligomers, and adduct acrylate polymers, or two or more may be combined, or may be combined with other active energy ray curable components.

When the adhesive composition P contains an active energy ray curable component (E), the content of the active energy ray curable component (E) is preferably 2 parts by mass or more, and particularly preferably 4 parts by mass or more, per 100 parts by mass of the (meth)acrylic acid ester polymer (A). The content is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and particularly preferably 6 parts by mass or less. When the content of the active energy ray curable component (E) is within the above range, the cohesive strength and adhesive strength of the adhesive after curing with active energy rays are improved, and the durability is more excellent.

(1-6) Photopolymerization initiator (F)
In the case where the adhesive obtained from the adhesive composition P is used as an active energy ray-curable adhesive, and ultraviolet rays are used as the active energy rays, it is preferable that the adhesive composition P further contains a photopolymerization initiator (F). By containing the photopolymerization initiator (F), the active energy ray-curable component (E) can be polymerized efficiently, and the polymerization and curing time and the irradiation dose of the active energy rays can be reduced.

Examples of such photopolymerization initiators (F) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzof Examples of the benzoxanthone include phenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tertiary-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], and 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide. These may be used alone or in combination of two or more.

When the adhesive composition P contains an active energy ray curable component (E) and a photopolymerization initiator (F), the content of the photopolymerization initiator (F) is preferably 1 part by mass or more as a lower limit, and more preferably 5 parts by mass or more, per 100 parts by mass of the active energy ray curable component (E). The content is preferably 30 parts by mass or less as an upper limit, and particularly preferably 15 parts by mass or less. By having the content of the photopolymerization initiator (F) within the above range, the cohesive strength and adhesive strength of the adhesive after curing with active energy rays are improved, and durability is improved.

(1-7) Various Additives Various additives that are commonly used in acrylic adhesives, such as an ultraviolet absorber, an antistatic agent, a tackifier, an antioxidant, a light stabilizer, a softener, a filler, a refractive index adjuster, etc., may be added to the adhesive composition P as desired. Note that polymerization solvents and dilution solvents described below are not included in the additives that constitute the adhesive composition P.

Examples of ultraviolet absorbents include compounds based on benzophenones, benzotriazoles, benzoates, benzoxazinones, triazines, phenyl salicylates, cyanoacrylates, and nickel complex salts. Of these, it is preferable to use at least one of benzophenone compounds, benzotriazole compounds, and triazine compounds.

Examples of the benzophenone compounds include 2,2-dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid hydrate, 2-hydroxy-4-n-octyloxybenzophenone, etc.

Examples of the benzotriazole compounds include 2-(2-hydroxy-5-t-butylphenyl)-2H-benzotriazole, octyl-3-[3-t-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate, 2-ethylhexyl-3-[3-t-butyl-4-hydroxy-5-(5-chloro-2H-benzotriazol-2-yl)phenyl]propionate, and 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzenepropanoic acid.

Examples of the triazine compounds include 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3-5-triazine, 2-[4,6-di(2,4-xylyl)-1,3,5-triazin-2-yl]-5-octyloxyphenol, etc.

The above UV absorbents may be used alone or in combination of two or more.

When the adhesive composition P contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.1 parts by mass or more, and more preferably 0.8 parts by mass or more, per 100 parts by mass of the (meth)acrylic acid ester polymer (A). The content is preferably 15 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 2 parts by mass or less. When the content of the ultraviolet absorber is within the above range, the adhesive layer is more likely to exhibit good ultraviolet absorption properties.

The adhesive composition P represents a mixture of various components remaining in the adhesive layer either as is or after reacting, and does not include components that are removed during the drying process, such as the polymerization solvent and dilution solvent described below.

(2) Production of adhesive composition The adhesive composition P can be produced by producing a (meth)acrylic acid ester polymer (A), mixing the obtained (meth)acrylic acid ester polymer (A) with a rust inhibitor (B), and, if desired, adding a crosslinking agent (C), a silane compound (D), an active energy ray-curable component (E), a photopolymerization initiator (F), additives, etc.

The (meth)acrylic acid ester polymer (A) can be produced by polymerizing a mixture of monomer units constituting the polymer by a normal radical polymerization method. The polymerization of the (meth)acrylic acid ester polymer (A) can be carried out by a solution polymerization method or the like, using a polymerization initiator as desired. Examples of polymerization solvents include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, methyl ethyl ketone, etc., and two or more types may be used in combination.

Examples of polymerization initiators include azo compounds and organic peroxides, and two or more of them may be used in combination. Examples of azo compounds include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane 1-carbonitrile), 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), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane].

Examples of organic peroxides include benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionyl peroxide, and diacetyl peroxide.

In addition, in the above polymerization process, the weight average molecular weight of the resulting polymer can be adjusted by adding a chain transfer agent such as 2-mercaptoethanol.

Once the (meth)acrylic acid ester polymer (A) is obtained, the rust inhibitor (B), crosslinking agent (C), silane compound (D), active energy ray curable component (E), photopolymerization initiator (F), additives, dilution solvent, etc. can be added to the solution of the (meth)acrylic acid ester polymer (A) and thoroughly mixed to obtain a solvent-diluted adhesive composition P (coating solution).

Examples of the dilution 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; alcohols such as methanol, ethanol, propanol, butanol, and 1-methoxy-2-propanol; ketones such as acetone, methyl ethyl ketone, 2-pentanone, isophorone, and cyclohexanone; esters such as ethyl acetate and butyl acetate; and cellosolve-based solvents such as ethyl cellosolve.

The concentration and viscosity of the coating solution thus prepared are not particularly limited as long as they are within the range that allows coating, and can be appropriately selected according to the situation. For example, the adhesive composition P is diluted so that the concentration is 10 to 40 mass %. Note that the addition of a dilution solvent or the like is not a necessary condition for obtaining the coating solution, and if the adhesive composition P has a viscosity that allows coating, it is not necessary to add a dilution solvent. In this case, the adhesive composition P becomes a coating solution in which the polymerization solvent for the (meth)acrylic acid ester polymer (A) itself serves as the dilution solvent.

(3) Formation of adhesive layer The adhesive layer in the display according to this embodiment is preferably made of an adhesive obtained by crosslinking the above-mentioned adhesive composition P (coating layer). The crosslinking of the adhesive composition P can be carried out by a heat treatment. This heat treatment can also serve as a drying treatment for volatilizing the dilution solvent of the coated adhesive composition P.

When heat treatment is performed, the heating temperature is preferably 50 to 150°C, and more preferably 70 to 120°C. The heating time is preferably 30 seconds to 10 minutes, and more preferably 50 seconds to 2 minutes. After heat treatment, a curing period of about 1 to 2 weeks may be provided at room temperature (e.g., 23°C, 50% RH) as necessary. If this curing period is required, the adhesive layer is formed after the curing period has elapsed, and if no curing period is required, the adhesive layer is formed after the heat treatment is completed.

(4) Physical properties of adhesive (gel fraction)
The gel fraction of the adhesive constituting the adhesive layer in the display according to the present embodiment is preferably 30% or more as a lower limit, particularly preferably 40% or more, and more preferably 45% or more. When the lower limit of the gel fraction of the adhesive is as above, the cohesive force is improved and the durability is higher. In addition, the gel fraction is preferably 90% or less as an upper limit, more preferably 80% or less, and particularly preferably 75% or less, and from the viewpoint of further increasing the adhesive strength, it is preferably 65% or less, and more preferably 55% or less. When the upper limit of the gel fraction of the adhesive is as above, the adhesive does not become too hard and the adhesive strength is higher. In addition, the rust inhibitor (B) is easily segregated to the surface layer of the adhesive layer. The method for measuring the gel fraction of this adhesive is as shown in the test example described later.

(5) Thickness of the adhesive layer The lower limit of the thickness of the adhesive layer 11 (measured according to JIS K7130) is preferably 1 μm or more, more preferably 5 μm or more, particularly preferably 10 μm or more, and even more preferably 20 μm or more. By setting the lower limit of the thickness of the adhesive layer 11 as above, the coverage is easily within the above-mentioned range. In addition, even in the case of wiring that is finely divided and narrowed in pitch, the rust inhibitor (B) is continuously supplied from the adhesive on the upper part of the wiring to the adhesive between the wiring, making it easier to maintain the concentration of the rust inhibitor (B) uniform in the vicinity of the wiring. This allows a more excellent migration prevention effect to be exhibited, and the film formation by the rust inhibitor (B) is maintained over time, thereby suppressing color changes in the wiring and the adhesive layer. In addition, by setting the lower limit of the thickness of the adhesive layer 11 as above, excellent adhesion is fully exhibited.

The upper limit of the thickness of the adhesive layer 11 is preferably 200 μm or less, more preferably 100 μm or less, and particularly preferably 80 μm or less. By setting the upper limit of the thickness of the adhesive layer 11 as described above, the degree of coverage is more likely to fall within the above-mentioned range. In addition, the absolute amount of the rust inhibitor (B) contained in the adhesive layer 11 can be reduced, so that the color change of the wiring caused by the rust inhibitor (B) can be suppressed. Furthermore, the processability of the adhesive sheet 1 is improved. In terms of being able to obtain a thinner display body while exhibiting an excellent migration effect while making it easy for the degree of coverage to fall within the above-mentioned range, the upper limit of the thickness of the adhesive layer 11 is preferably 60 μm or less, and more preferably 30 μm or less. The adhesive layer 11 may be formed as a single layer, or may be formed by laminating multiple layers.

1-2. Release Sheet The release sheets 12a and 12b are not particularly limited, and known plastic films can be used. For example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene-(meth)acrylic acid copolymer film, ethylene-(meth)acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, etc. can be used. Crosslinked films of these can also be used. Furthermore, laminated films of these can also be used.

It is preferable that the release surfaces of the release sheets 12a and 12b (particularly the surfaces in contact with the adhesive layer 11) are subjected to a release treatment. Examples of release agents used in the release treatment include alkyd-based, silicone-based, fluorine-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents. It is preferable that one of the release sheets 12a and 12b is a heavy release type release sheet with a large release force, and the other is a light release type release sheet with a small release force.

There are no particular limitations on the thickness of the release sheets 12a and 12b, but it is usually about 20 to 150 μm.

2. Manufacturing of adhesive sheet In one manufacturing example of the adhesive sheet 1, the coating solution of the adhesive composition P is applied to the release surface of one release sheet 12a (or 12b), the adhesive composition P is crosslinked by heat treatment to form a coating layer, and then the release surface of the other release sheet 12b (or 12a) is superimposed on the coating layer. If a curing period is required, a curing period is provided, and if no curing period is required, the coating layer becomes the adhesive layer 11 as it is. This results in the adhesive sheet 1. The conditions for the heat treatment and curing are as described above.

In another example of the production of the adhesive sheet 1, the coating liquid of the adhesive composition P is applied to the release surface of one of the release sheets 12a, and the adhesive composition P is crosslinked by heat treatment to form a coating layer, thereby obtaining the release sheet 12a with the coating layer. The coating liquid of the adhesive composition P is applied to the release surface of the other release sheet 12b, and the adhesive composition P is crosslinked by heat treatment to form a coating layer, thereby obtaining the release sheet 12b with the coating layer. Then, the release sheet 12a with the coating layer and the release sheet 12b with the coating layer are bonded together so that both coating layers are in contact with each other. If a curing period is required, a curing period is provided, and if no curing period is required, the laminated coating layer becomes the adhesive layer 11 as it is. This results in the adhesive sheet 1. According to this production example, stable production is possible even when the adhesive layer 11 is thick.

Methods for applying the coating solution of the adhesive composition P include, for example, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating.

3. Physical properties of the adhesive sheet 3-1. Adhesive strength The adhesive strength of the adhesive sheet 1 capable of producing the display according to the present embodiment to soda lime glass is preferably 10 N/25 mm or more as a lower limit, particularly preferably 15 N/25 mm or more, and more preferably 20 N/25 mm or more. When the lower limit of the adhesive strength is as above, the durability of the adhesive layer 11 becomes more excellent. In addition, the upper limit of the adhesive strength is preferably 100 N/25 mm or less, more preferably 75 N/25 mm or less, particularly preferably 50 N/25 mm or less, further preferably 35 N/25 mm or less, and most preferably 25 N/25 mm or less. When the upper limit of the adhesive strength is as above, the adhesive sheet can effectively exhibit the migration suppression effect, the color change suppression effect, and the resistance value change suppression effect, while obtaining good reworkability, and can be re-applied even if an application error occurs.

The above adhesive strength basically refers to the adhesive strength measured by the 180-degree peeling method in accordance with JIS Z0237:2009. The measurement sample is 25 mm wide and 100 mm long, and the measurement sample is attached to the adherend and pressurized at 0.5 MPa and 50°C for 20 minutes, and then left to stand for 24 hours under normal pressure, 23°C, and 50% RH, before being measured at a peeling speed of 300 mm/min.

3-2. Haze value The haze value of the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 is preferably 1% or less, more preferably 0.5% or less, particularly preferably 0.3% or less, and even more preferably 0.2% or less. The above haze value of the pressure-sensitive adhesive layer 11 provides excellent light transmission and is suitable for use in displays. The lower limit of the haze value is not particularly limited, and is preferably 0% or more, and more preferably 0.01% or more.

The above haze value is a characteristic value including the thickness of the adhesive layer, and it is preferable to satisfy the above haze value regardless of the thickness of the adhesive layer. Here, the haze value in this specification is a value measured in accordance with JIS K7136:2000.

3-3. Total light transmittance The total light transmittance of the pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 is preferably 70% or more, more preferably 80% or more, particularly preferably 90% or more, further preferably 95% or more, and most preferably 99% or more. The pressure-sensitive adhesive layer 11 having the above total light transmittance has excellent light transmittance and is suitable for display use. The upper limit of the total light transmittance is usually 100%. The total light transmittance in this specification is a value measured in accordance with JIS K7361-1:1997.

3-4. CIE1976L*a*b* color system The pressure-sensitive adhesive layer 11 of the pressure-sensitive adhesive sheet 1 has an absolute value of chromaticity a* defined by the CIE1976L*a*b* color system of preferably 0 or more, particularly preferably 0.1 or more. The absolute value of the chromaticity a* is preferably 0.8 or less, particularly preferably 0.6 or less, and more preferably 0.4 or less. The absolute value of the chromaticity b* of the pressure-sensitive adhesive layer 11 is preferably 0 or more, particularly preferably 0.1 or more. The absolute value of the chromaticity b* is preferably 0.8 or less, particularly preferably 0.6 or less, and more preferably 0.4 or less. As a result, the pressure-sensitive adhesive layer 11 has a color suitable for display. The method for measuring the chromaticity a* and b* in this specification is as shown in the test examples described later.

[Display body]
The display according to this embodiment includes a first display member, a second display member, and an adhesive layer for bonding the first display member and the second display member to each other. The adhesive layer is required to be made of an adhesive containing a rust inhibitor, and is preferably made of an adhesive obtained from the adhesive composition P described above. Here, the first display member and/or the second display member has wiring made of metal or metal oxide at least on the surface to be bonded (adhesive layer side). In a preferred configuration, the second display member has the wiring at least on the surface to be bonded.

Examples of the display include a liquid crystal display (LCD) display, a light-emitting diode (LED) display, an organic electroluminescence (OLED) display, electronic paper, etc., and may also be a touch panel. The display may also be a component that constitutes a part of these.

The first display member and the second display member may both be rigid and inflexible. The adhesive layer obtained from the adhesive composition P described above allows the first display member, which is a rigid body, and the second display member, which is also a rigid body, to be bonded together without any problems.

The first display member is preferably a protective panel made of a glass plate, a plastic plate, or a laminate containing these. The first display member may have a step on the surface on the adhesive layer side. In this case, specifically, it is preferable that the step is caused by a printing layer. This printing layer is generally formed in a frame shape.

The glass plate is not particularly limited, and examples thereof include chemically strengthened glass, alkali-free glass, quartz glass, soda-lime glass, barium-strontium-containing glass, aluminosilicate glass, lead glass, borosilicate glass, barium borosilicate glass, etc. The thickness of the glass plate is not particularly limited, but is usually 0.1 to 5 mm, and preferably 0.2 to 2 mm.

The above-mentioned plastic plate is not particularly limited, but examples thereof include acrylic plates and polycarbonate plates. The thickness of the plastic plate is not particularly limited, but is usually 0.2 to 5 mm, and preferably 0.4 to 3 mm.

In addition, various functional layers (electrode layer, silica layer, hard coat layer, anti-glare layer, etc.) may be provided on one or both sides of the above glass plate or plastic plate, or optical members may be laminated thereon.

The material constituting the printing layer is not particularly limited, and known materials for printing are used. The thickness of the printing layer, i.e., the lower limit of the height of the step, is preferably 3 μm or more, more preferably 5 μm or more, particularly preferably 7 μm or more, and most preferably 10 μm or more. By setting the lower limit above, it is possible to ensure sufficient concealment, such as making the electrical wiring invisible to the viewer. In addition, the upper limit is preferably 50 μm or less, more preferably 35 μm or less, particularly preferably 25 μm or less, and even more preferably 20 μm or less. By setting the upper limit below the above, it is possible to prevent the step-following ability of the adhesive layer relative to the printing layer from deteriorating.

The second display component is an optical member to which the first display component is to be attached, a display module (e.g., a liquid crystal (LCD) module, a light emitting diode (LED) module, an organic electroluminescence (organic EL) module, etc.), an optical member as part of a display module, or a laminate including a display module, and preferably has wiring made of metal or metal oxide on at least the surface facing the adhesive layer.

Examples of the optical components include film sensors, electrode films, metal nanowire films, wire grid polarizing films, etc.

Examples of wiring made of metal include wiring made of silver, silver alloy, copper, copper alloy, etc. (including mesh-shaped, grid-shaped, and nanowire-shaped wiring). In particular, preferred examples include wiring that constitutes electrodes of touch panels, specifically, wiring contained in film sensors. Among the above-mentioned metal wirings, wiring made of nanoparticles of silver or silver alloy is preferred, and as a silver alloy, silver alloy metal wiring in which palladium and copper are added to silver is particularly preferred. Unoxidized metals have a higher tendency to ionize than metal oxides such as ITO, but according to the display according to this embodiment, even in such cases, disconnection or short circuit of the wiring is effectively prevented.

Wiring made of metal oxides includes, for example, patterned transparent conductive films made of metal oxides such as tin-doped indium oxide (ITO) and zinc oxide. Among the above, patterned transparent conductive films made of ITO are particularly preferred, as the ITO transparent conductive film is likely to exhibit excellent migration prevention effects.

The wiring width of the metal or metal oxide is preferably 50 μm or less, more preferably 30 μm or less. The wiring width is preferably 1 μm or more, more preferably 4 μm or more, particularly preferably 8 μm or more, and even more preferably 10 μm or more. When the wiring width is in the above range, it contributes to the fineness and narrowing of the electrode pitch while making it easier for the coverage to fall within the above-mentioned range, so that a more excellent migration prevention effect can be exhibited. This can contribute to improving the connection reliability of the electrodes. From the viewpoint of obtaining a display having finer and narrower-pitched wiring while still having a coverage within the above-mentioned range, it is particularly preferable for the wiring width to be 20 μm or less, and even more preferable for it to be 12 μm or less.

The distance between the gaps (inter-wire distance) between the wirings made of the above metal or metal oxide is preferably 50 μm or less, more preferably 30 μm or less. The inter-wire distance is preferably 1 μm or more, more preferably 4 μm or more, particularly preferably 8 μm or more, and even more preferably 10 μm or more. When the inter-wire distance is within the above range, it contributes to the fineness and narrowing of the electrodes while making it easier for the coverage to fall within the above range, so that a more excellent migration prevention effect can be achieved. This can contribute to improving the connection reliability of the electrodes. From the viewpoint of obtaining a display having finer and narrower-pitched wiring while still having a coverage within the above range, it is particularly preferable for the distance to be 20 μm or less, and even more preferable for it to be 12 μm or less.

The thickness of the wiring made of the above metal or metal oxide is preferably 1 μm or less, more preferably 0.6 μm or less, particularly preferably 0.3 μm or less, and even more preferably 0.2 μm or less. The thickness of the wiring is preferably 0.01 μm or more, more preferably 0.05 μm or more, particularly preferably 0.1 μm or more, and even more preferably 0.15 μm or more. When the wiring thickness is in the above range, it contributes to thinning the electrode while making it easier for the coverage to fall within the above-mentioned range, so that a more excellent migration prevention effect can be achieved. This can contribute to improving the connection reliability of the electrodes, etc.

2 shows a capacitive touch panel 2 as an example of a display according to this embodiment. The touch panel 2 is configured to include a display module 3, a first film sensor 5a laminated thereon via an adhesive layer 4, a second film sensor 5b laminated thereon via a first adhesive layer 11, and a cover material 6 laminated thereon via a second adhesive layer 11. A printed layer 7 is formed on the surface of the cover material 6 facing the second adhesive layer 11, and therefore a step exists depending on the presence or absence of the printed layer 7. In this embodiment, the cover material 6 corresponds to the first display member, and the second film sensor 5b corresponds to the second display member, or the second film sensor 5b corresponds to the first display member and the first film sensor 5a corresponds to the second display member.

Considering the migration prevention effect, it is preferable that both the first adhesive layer 11 and the second adhesive layer 11 in the touch panel 2 are the adhesive layer 11 of the adhesive sheet 1. If the first adhesive layer 11 or the second adhesive layer 11 is not the adhesive layer 11 of the adhesive sheet 1, examples of the adhesive constituting the adhesive layer include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, etc., and among these, acrylic adhesives are preferred.

The adhesive layer 4 may be formed by the adhesive layer 11 of the adhesive sheet 1, or by another adhesive or adhesive sheet. In the latter case, examples of adhesives constituting the adhesive layer 4 include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, polyester adhesives, polyvinyl ether adhesives, etc., of which acrylic adhesives are preferred.

In this embodiment, the first film sensor 5a and the second film sensor 5b each include a base film 51 and an electrode 52 formed on the base film 51. The base film 51 is not particularly limited, but may be, for example, a polyethylene terephthalate film, an acrylic film, a polycarbonate film, or the like.

The electrode 52 of the first film sensor 5a and/or the electrode 52 of the second film sensor 5b are composed of wiring made of metal or metal oxide. Examples of wiring made of metal or metal oxide include those described above. Typically, one of the electrodes 52 of the first film sensor 5a and the electrode 52 of the second film sensor 5b forms a circuit pattern in the X-axis direction, and the other forms a circuit pattern in the Y-axis direction.

In this embodiment, the electrode 52 of the second film sensor 5b is located above the second film sensor 5b in FIG. 2. On the other hand, the electrode 52 of the first film sensor 5a is located above the first film sensor 5a in FIG. 2, but is not limited to this and may be located below the first film sensor 5a.

An example of a method for manufacturing the touch panel 2 will be described below.
A first adhesive sheet 1 and a second adhesive sheet 1 are prepared as the adhesive sheet 1. One release sheet 12a is peeled off from the first adhesive sheet 1, and the exposed adhesive layer 11 (first adhesive layer) is attached to the first film sensor 5a so as to contact the electrode 52 of the first film sensor 5a. Also, one release sheet 12a is peeled off from the second adhesive sheet 1, and the exposed adhesive layer 11 (second adhesive layer 11) is attached to the second film sensor 5b so as to contact the electrode 52 of the second film sensor 5b.

Then, the other release sheet 12b of the first adhesive sheet 1 is peeled off, and the two are attached so that the exposed first adhesive layer 11 contacts the surface of the second film sensor 5b opposite to the side on which the second adhesive layer 11 is laminated (the exposed surface of the base film 51 of the second film sensor 5b). This results in a laminate in which the release sheet 12b, the second adhesive layer 11, the second film sensor 5b, the first adhesive layer 11, and the first film sensor 5a are laminated in this order.

Next, the adhesive layer 4 provided on the release sheet is attached to the surface of the laminate facing the first film sensor 5a (the exposed surface of the base film 51 of the first film sensor 5a). Next, the release sheet 12b is peeled off from the laminate, and the cover material 6 is attached to the exposed second adhesive layer 11 so that the printed layer 7 side of the cover material 6 is in contact with the second adhesive layer 11. By the above attachment, a structure is obtained in which the cover material 6, the second adhesive layer 11, the second film sensor 5b, the first adhesive layer 11, the first film sensor 5a, the adhesive layer 4, and the release sheet are laminated in this order.

Then, the release sheet is peeled off from the above-mentioned structure, and the structure is attached to the display module 3 so that the exposed adhesive layer 4 contacts the display module 3. This completes the production of the touch panel 2 shown in FIG. 2.

Here, when the first adhesive layer 11 and/or the second adhesive layer 11 is made of an active energy ray-curable adhesive, the adhesive layer 11 in the above-mentioned structure or touch panel 2 is irradiated with active energy rays. This causes the active energy ray-curable component (E) in the adhesive layer 11 to polymerize, and the adhesive layer 11 is cured to become a cured adhesive layer. The energy rays are usually irradiated to the adhesive layer 11 from one side of the above-mentioned structure or touch panel 2, and preferably from the side of the cover material 6.

Note that active energy rays refer to electromagnetic waves or charged particle beams that have an energy quantum, and specific examples include ultraviolet rays and electron beams. Among active energy rays, ultraviolet rays are particularly preferred because they are easy to handle.

The irradiation of ultraviolet rays can be performed by a high pressure mercury lamp, a fusion H lamp, a xenon lamp, or the like, and the irradiation amount of ultraviolet rays is preferably 50 to 1000 mW/cm ² in terms of illuminance, and more preferably 100 to 600 mW/cm ^2. The light amount is preferably 50 to 10,000 mJ/cm ² , more preferably 80 to 5,000 mJ/cm ² , and particularly preferably 200 to 2,000 mJ/cm ^2. On the other hand, the irradiation of electron beams can be performed by an electron beam accelerator, and the irradiation amount of electron beams is preferably about 10 to 1,000 krad.

The gel fraction of the adhesive (adhesive after active energy ray irradiation) constituting the cured adhesive layer is preferably 40% or more as a lower limit, particularly preferably 55% or more, and more preferably 65% or more. When the lower limit of the gel fraction of the adhesive after active energy ray irradiation is as above, the durability is higher. In addition, the upper limit of the gel fraction is preferably 90% or less, particularly preferably 80% or less, and more preferably 75% or less. When the upper limit of the gel fraction of the adhesive after active energy ray irradiation is as above, it is possible to prevent the adhesive strength of the cured adhesive layer from decreasing and the durability from deteriorating. The method for measuring the gel fraction of the adhesive after active energy ray irradiation is as shown in the test example described later.

The adhesive strength of the adhesive sheet having the cured adhesive layer to soda lime glass is preferably 10 N/25 mm or more as a lower limit, more preferably 20 N/25 mm or more, particularly preferably 30 N/25 mm or more, and even more preferably 40 N/25 mm or more. When the lower limit of the adhesive strength is as above, the durability of the resulting product (touch panel 2) is high. The upper limit of the adhesive strength is not particularly limited, but is usually preferably 100 N/25 mm or less, particularly preferably 80 N/25 mm or less, and even more preferably 60 N/25 mm or less.

The above adhesive strength is basically the adhesive strength measured by the 180-degree peel method in accordance with JIS Z0237:2009, with the measurement sample being 25 mm wide and 100 mm long. The measurement sample is attached to the adherend and pressurized at 0.5 MPa and 50°C for 20 minutes, then irradiated with active energy rays (ultraviolet rays) under the conditions shown in the test example described below, and left for 24 hours under conditions of normal pressure, 23°C, and 50% RH, before being measured at a peel speed of 300 mm/min.

When the touch panel 2 is placed under high temperature and high humidity conditions and a voltage is applied to the electrode 52 under these conditions, migration of the electrode 52 is effectively suppressed, and changes in the resistance value of the electrode 52 are also effectively suppressed, even if the electrode 52 is composed of wiring made of a metal or metal oxide. This prevents driving failure of the touch panel 2 due to breaks or short circuits in the electrode 52.

Here, the change in resistance value of the electrode 52 will be specifically described. When polyethylene terephthalate and an electrode plate (silver wiring electrode plate in the embodiment) are laminated via the adhesive layer 11 of the adhesive sheet 1, and a durability test (105°C, 100% RH, 3 hours, 5V voltage applied) is performed on the resulting laminate, the resistance value change rate of the electrode plate calculated by the following formula is preferably less than 500%, and more preferably less than 100%. The lower limit is not particularly limited, but is preferably 0% or more.
Resistance change rate (%)={(R−R ⁰ )/R ⁰ }×100
(In the formula, ^R0 is the initial resistance value (Ω) before the durability test, and R is the resistance value (Ω) after the durability test.)
The details of the method for measuring the rate of change in resistance value are as shown in the test examples described later.

When a soda lime glass and an ITO vapor-deposited film are laminated via the adhesive layer 11 of the adhesive sheet 1, and a durability test (85°C, 85% RH, 1000 hours) is performed on the resulting laminate, the resistance change rate of the ITO vapor-deposited film calculated by the above formula is preferably less than 300%, more preferably less than 100%, and even more preferably less than 50%. The lower limit is not particularly limited, but is preferably 0% or more. Similarly, when a soda lime glass and an ITO vapor-deposited film are laminated via the adhesive layer 11 of the adhesive sheet 1, and a durability test (95°C, 1000 hours) is performed on the resulting laminate, the resistance change rate of the ITO vapor-deposited film calculated by the above formula is preferably less than 100%, more preferably less than 50%, and even more preferably less than 20%. The lower limit is not particularly limited, but is preferably 0% or more.

The above-described embodiments are described to facilitate understanding of the present invention, and are not described to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

For example, one of the release sheets 12a and 12b in the adhesive sheet 1 may be omitted. Also, in the touch panel 2, the printing layer 7 may not be formed on the cover material 6.

The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

Example 1
1. Preparation of (meth)acrylic acid ester polymer (A) 60 parts by mass of 2-ethylhexyl acrylate, 20 parts by mass of methyl methacrylate, and 20 parts by mass of 2-hydroxyethyl acrylate were copolymerized by a solution polymerization method to prepare a (meth)acrylic acid ester polymer (A). The molecular weight of this (meth)acrylic acid ester polymer (A) was measured by the method described below, and the weight average molecular weight (Mw) was 800,000.

2. Preparation of adhesive composition 100 parts by mass (solid content equivalent; the same below) of the (meth)acrylic acid ester polymer (A) obtained in the above step 1, 0.01 parts by mass of 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole as a rust inhibitor (B), 0.25 parts by mass of trimethylolpropane adduct tolylene diisocyanate as a crosslinking agent (C), and 0.25 parts by mass of 3-glycidyloxypropyltrimethoxysilane (D1) as a silane compound (D) were mixed, thoroughly stirred, and diluted with methyl ethyl ketone to obtain a coating solution of an adhesive composition.

[活性エネルギー線硬化性成分（Ｅ）]
ε－カプロラクトン変性トリス－（２－アクリロキシエチル）イソシアヌレート（新中村化学社製，製品名「ＮＫエステル Ａ－９３００－１ＣＬ」）
[光重合開始剤（Ｆ）]
１－ヒドロキシ－シクロヘキシル－フェニル－ケトンとベンゾフェノンとの１：１（質量比）混合物
[紫外線吸収剤]
ベンゾトリアゾール系紫外線吸収剤（ＢＡＳＦジャパン社製，製品名「ＴＩＮＵＶＩＮ ３８４－２」） Here, the formulations (solid content equivalent) of the pressure-sensitive adhesive composition when the (meth)acrylic acid ester polymer (A) is taken as 100 parts by mass (solid content equivalent) are shown in Table 1. Details of the abbreviations, components, etc. shown in Table 1 are as follows.
[(Meth)acrylic acid ester polymer (A)]
2EHA: 2-ethylhexyl acrylate MMA: methyl methacrylate HEA: 2-hydroxyethyl acrylate IBXA: isobornyl acrylate ACMO: N-acryloylmorpholine BA: n-butyl acrylate
[Silane compound (D)]
D1: 3-glycidyloxypropyltrimethoxysilane D2: An organosilicon compound represented by the following structural formula (II):

[Active energy ray-curable component (E)]
ε-Caprolactone modified tris-(2-acryloxyethyl)isocyanurate (manufactured by Shin-Nakamura Chemical Co., Ltd., product name "NK Ester A-9300-1CL")
[Photopolymerization initiator (F)]
1:1 (mass ratio) mixture of 1-hydroxy-cyclohexyl-phenyl-ketone and benzophenone
[Ultraviolet absorber]
Benzotriazole-based ultraviolet absorber (manufactured by BASF Japan, product name "TINUVIN 384-2")

3. Manufacturing of adhesive sheet The coating solution of the adhesive composition obtained in the above step 2 was applied by a knife coater to the release-treated surface of a heavy-release type release sheet (manufactured by Lintec Corporation, product name "SP-PET382150", thickness: 38 μm) in which one side of a polyethylene terephthalate film had been release-treated with a silicone-based release agent, and then the sheet was heated at 80° C. for 1 minute and further heated at 110° C. for 1 minute to form a coating layer (thickness: 75 μm).

Then, the coating layer on the heavy release type release sheet obtained above and a light release type release sheet (manufactured by Lintec Corporation, product name "SP-PET381130"), one side of which was a polyethylene terephthalate film treated with a silicone-based release agent, were attached so that the release-treated surface of the light release type release sheet was in contact with the coating layer, and the sheet was cured for 7 days under conditions of 23°C and 50% RH to produce an adhesive sheet consisting of heavy release type release sheet/adhesive layer (thickness: 75 μm)/light release type release sheet. The content of the rust inhibitor (B) in the adhesive constituting the adhesive layer was 0.01% by mass.

[Examples 2 to 14, Comparative Examples 1 to 6]
Pressure-sensitive adhesive sheets were produced in the same manner as in Example 1, except that the types and ratios of the monomers constituting the (meth)acrylic acid ester polymer (A), the weight average molecular weight of the (meth)acrylic acid ester polymer (A), the amount of the rust inhibitor (B), the amount of the crosslinking agent (C), the type of the silane compound (D), and the thickness of the pressure-sensitive adhesive layer were changed as shown in Table 1. Note that in Example 4, an ultraviolet absorber was further added, and in Example 12, an active energy ray-curable component (E) and a photopolymerization initiator (F) were further added.

The weight average molecular weight (Mw) mentioned above is a polystyrene-equivalent weight average molecular weight measured by gel permeation chromatography (GPC) under the following conditions (GPC measurement).
<Measurement conditions>
GPC measuring device: Tosoh Corporation, HLC-8020
GPC columns (passed in the following order): TSK guard column HXL-H manufactured by Tosoh Corporation
TSK gel GMHXL (x2)
TSK gel G2000HXL
Measurement solvent: tetrahydrofuran Measurement temperature: 40°C

[Test Example 1] (Measurement of gel fraction)
The pressure-sensitive adhesive sheets obtained in the Examples and Comparative Examples were cut to a size of 80 mm x 80 mm, the pressure-sensitive adhesive layer was wrapped in a polyester mesh (mesh size 200), and the mass was measured using a precision balance. The mass of the mesh alone was subtracted to calculate the mass of the pressure-sensitive adhesive alone. This mass was designated M1.

Next, the adhesive wrapped in the polyester mesh was immersed in ethyl acetate at room temperature (23°C) for 24 hours. The adhesive was then removed and air-dried for 24 hours in an environment with a temperature of 23°C and a relative humidity of 50%, and then dried in an oven at 80°C for 12 hours. After drying, the mass was weighed using a precision balance, and the mass of the adhesive alone was calculated by subtracting the mass of the mesh alone. This mass was designated M2. The gel fraction (%) was expressed as (M2/M1) x 100. The results are shown in Table 2.

For the adhesive sheet of Example 12, the gel fraction was measured before and after the adhesive layer was irradiated with ultraviolet (UV) light (irradiated from the heavy release type release sheet side). The ultraviolet light irradiation conditions were as follows.

<Ultraviolet irradiation conditions>
- Uses high pressure mercury lamp - Illuminance 200mW/ ^cm2 , light quantity 1000mJ/ ^cm2
・UV illuminance/light intensity meter used is "UVPF-A1" manufactured by iGraphics Co., Ltd.

[Test Example 2] (Measurement of adhesive strength)
The light release type release sheet was peeled off from the adhesive sheet obtained in the examples and comparative examples, and the exposed adhesive layer was attached to an easy-adhesion layer of a polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., product name "Cosmoshine PET100A4360", thickness: 100 μm) having an easy-adhesion layer, to obtain a laminate of heavy release type release sheet/adhesive layer/PET film. The obtained laminate was cut into a width of 25 mm and a length of 100 mm, and this was used as a sample.

In an environment of 23°C and 50% RH, the heavy release type release sheet was peeled off from the above sample, and the exposed adhesive layer was attached to soda lime glass (manufactured by Nippon Sheet Glass Co., Ltd.), and then pressure was applied for 20 minutes at 0.5 MPa and 50°C in an autoclave manufactured by Kurihara Seisakusho Co., Ltd. After leaving the sample for 24 hours under conditions of 23°C and 50% RH, the adhesive strength (N/25 mm) was measured using a tensile tester (manufactured by Orientec Co., Ltd., product name "Tensilon") at a peel speed of 300 mm/min and a peel angle of 180 degrees. Measurements were performed in accordance with JIS Z0237:2009 under conditions other than those described here. The results are shown in Table 2.

The adhesive sheet of Example 12 was also measured for adhesive strength after exposure to ultraviolet (UV) light. Specifically, after the autoclave treatment, the adhesive layer was irradiated with ultraviolet light from the soda lime glass side under the same conditions as in Test Example 1. The sheet was then left for 24 hours under conditions of 23°C and 50% RH, after which the adhesive strength (N/25 mm; after UV) was measured in the same manner as above. The results are shown in Table 2.

[Test Example 3] (Measurement of haze value)
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet produced in the Examples and Comparative Examples was attached to glass to prepare a measurement sample. After background measurement was performed on the glass, the haze value (total light haze value;%) of the measurement sample was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "NDH-5000") in accordance with JIS K7136:2000. The results are shown in Table 2.

[Test Example 4] (Measurement of total light transmittance)
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet produced in the Examples and Comparative Examples was attached to glass to prepare a measurement sample. After background measurement was performed on the glass, the total light transmittance (%) of the measurement sample was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") in accordance with JIS K7361-1:1997. The results are shown in Table 2.

[Test Example 5] (Measurement of L*a*b* color system)
The chromaticity a* and chromaticity b* defined by the CIE1976 L*a*b* color system were measured for the adhesive layers of the adhesive sheets prepared in the Examples and Comparative Examples using a simultaneous photometric spectrophotometer (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SQ2000"). The results are shown in Table 2.

[Test Example 6] (Evaluation of migration prevention effect using silver wiring electrode plate)
(1) Preparation of silver wiring electrode plate On one side of soda lime glass (length 70 mm × width 150 mm × thickness 1.0 mm; manufactured by Nippon Sheet Glass Co., Ltd.), silver paste (manufactured by Toyochem Co., Ltd., product name "RA FS088") was applied by screen printing so that the positive electrode wiring and the negative electrode wiring were linear and parallel. Then, by performing a heat treatment at 135 ° C. for 30 minutes and curing, glass (silver wiring electrode plate) on which silver wiring (thickness: 0.15 μm) was printed was obtained. Silver wiring electrode plate X ₁₀ with a wiring width of 10 μm; the distance between the wiring gap (wiring distance) of the positive electrode and the negative electrode, silver wiring electrode plate X ₁₅ with a wiring width of 15 μm; the wiring distance of 15 μm; the wiring distance of 30 μm; the wiring distance of _{30 μm} were prepared. The wiring thickness of each silver wiring electrode plate was 0.15 μm.

(2) Calculation of the degree of coating The light release type release sheet was peeled off from the adhesive sheet obtained in the examples and comparative examples, and the exposed adhesive layer was attached to the easy-adhesion layer of a polyethylene terephthalate (PET) film (manufactured by Toyobo Co., Ltd., product name "Cosmoshine PET100A4360", thickness: 100 μm) having an easy-adhesion layer to obtain a heavy release type release sheet / adhesive layer / PET film laminate. Next, the heavy release type release sheet was peeled off from the laminate, and the exposed adhesive layer was attached to the positive electrode wiring and the negative electrode wiring in the silver wiring electrode plate _X10 , _X15 or _X30 . Then, the plate was autoclaved for 20 minutes under conditions of 50 ° C. and 0.5 MPa, and then left for 24 hours under conditions of 23 ° C. and 50% RH, and this was used as a silver wiring electrode plate sample.

For the adhesive sheet of Example 12, after the autoclave treatment, the adhesive layer was irradiated with ultraviolet light from the PET film side under the same conditions as in Test Example 1, and this was used as a sample.

Here, the coverage of the silver wiring electrode plate sample consisting of the adhesive sheet produced in Example 1 and the silver wiring electrode plate _X10 was calculated as follows.
First, the wiring volume (μm ³ ) per 1 mm ² (1000 μm×1000 μm) in a plan view of the wiring in the silver wiring electrode plate sample was calculated as follows.
The silver wiring electrode plate X ₁₀ has a wiring width of 10 μm, a distance between the wirings of 10 μm, and a wiring thickness of 0.15 μm. In this case, the wiring volume per wiring is
10 μm x 0.15 μm x 1000 μm (μm ³ )
The number of wirings per 1 ^mm2 (1000 μm×1000 μm) in plan view is:
1000μm/(10μm+10μm) (pieces)
Therefore, the wiring volume (μm ³ ) per 1 mm ² in plan view of the wiring was calculated by the following formula (1-1).
{10μm×0.15μm×1000μm}×{1000μm/(10μm+10μm)}...(1-1)
Next, the adhesive volume (μm ³ ) per 1 mm ² (1000 μm × 1000 μm) in plan view of the adhesive layer of the silver wiring electrode plate sample was calculated using the following formula (2-1). As described above, the thickness of the adhesive layer of the adhesive sheet of Example 1 was 75 μm.
75 μm x 1000 μm x 1000 μm (μm ³ )...(2-1)
The degree of coverage was calculated by dividing (2-1) by (1-1).
For the other examples and comparative examples, the coverage was calculated in the same manner as in Example 1. The results are shown in Table 2.

(3) Migration Prevention Effect The above silver wiring electrode plate sample was left to stand for 3 hours under humid heat conditions of 105°C and 100% RH, and a voltage of 5 V was applied between the electrodes in that state. After that, the positive electrode wiring and the negative electrode wiring were observed with an optical microscope (magnification: 10 times), and the migration prevention effect was evaluated based on the evaluation criteria shown below. The results are shown in Table 2. In addition, no defects such as lifting, peeling, or the generation of bubbles were confirmed in any of the samples of the examples and comparative examples.
◯: No dissolution of the positive electrode wiring or no dendrite formation in the negative electrode wiring was observed.
×: Dissolution of the positive electrode wiring or formation of dendrites in the negative electrode wiring is observed.

[Test Example 7] (Evaluation of color change of wiring using silver wiring electrode plate)
A silver wiring electrode plate sample prepared in the same manner as in Test Example 6 was left to stand for 3 hours under humid heat conditions of 105°C and 100% RH, and a voltage of 5 V was applied between the electrodes in this state. After that, the positive electrode wiring and the negative electrode wiring were observed with an optical microscope (magnification: 10 times), and the color change of the wiring was evaluated based on the following evaluation criteria. The results are shown in Table 2.
⊚: There is no change in color of the positive and negative wiring.
○: Discoloration is observed in the positive or negative wiring.
-: Migration occurred (dissolution of the positive electrode wiring or formation of dendrites in the negative electrode wiring was observed), so evaluation was not possible.

[Test Example 8] (Evaluation of resistance change using silver wiring electrode plate)
For the silver wiring electrode plate sample prepared in the same manner as in Test Example 6, a voltage of 5 V was applied between the positive electrode wiring and the negative electrode wiring, and the initial resistance value R ⁰ (Ω) was measured using a Digital HiTester (manufactured by Hioki E.E. Corporation, product name "Digital HiTester 3802-50").

Next, the silver wiring electrode plate sample was placed in a humid heat environment of 105°C and 100% RH for 3 hours, and a voltage of 5 V was applied between the electrodes in this state. After that, it was left to stand in a normal temperature and humidity environment of 23°C and 50% RH for 24 hours, and the resistance value (Ω) was measured in the same manner as the initial resistance value. This was the resistance value R after the durability test. The resistance value change rate (%) was calculated from the obtained measured values using the following formula.
Resistance change rate (%)={(R−R ⁰ )/R ⁰ }×100

The resistance change was evaluated based on the rate of change in resistance calculated above, according to the following criteria. The results are shown in Table 2.
◯: The rate of change in resistance value is less than 100%. △: The rate of change in resistance value is 100% or more but less than 500%. ×: The rate of change in resistance value is 500% or more.

[Test Example 9] (Evaluation of resistance change using ITO vapor-deposited film)
A soda lime glass (length 70 mm × width 150 mm × thickness 1.0 mm; manufactured by Nippon Sheet Glass Co., Ltd.) and an ITO vapor deposition film (manufactured by Oike Kogyo Co., Ltd., product name "Tetlite TCF KH150NMH2-125-U6/T2", the ITO vapor deposition film side contacting the adhesive layer) were bonded together via the adhesive layer of the adhesive sheet obtained in the Examples and Comparative Examples. Then, autoclaving was performed for 20 minutes under conditions of 50°C and 0.5 MPa, and then the sample was left for 24 hours under conditions of 23°C and 50% RH to obtain an ITO vapor deposition film sample.

For the adhesive sheet of Example 12, after the autoclave treatment, the adhesive layer was irradiated with ultraviolet light from the soda-lime glass side under the same conditions as in Test Example 1, and this was used as the measurement sample.

The initial resistance value R ⁰ (Ω) of the ITO vapor-deposited film sample was measured using a non-contact resistance measuring device (manufactured by Napson Corporation, product name "EC-80").

Next, the ITO vapor-deposited film samples were placed in a humid heat environment of 85°C and 85% RH for 1000 hours, or in a high temperature environment of 95°C for 1000 hours. They were then left to stand in a normal temperature and humidity environment of 23°C and 50% RH for 24 hours, and the resistance value (Ω) was measured in the same manner as the initial resistance value described above. This was defined as the resistance value R after the durability test. The resistance value change rate (%) was calculated from the obtained measured values using the same formula as in Test Example 8.

The resistance change was evaluated based on the rate of change in resistance calculated above, according to the following criteria. The results are shown in Table 2.
<Humidity and heat environment of 85℃/85%RH>
◎: Resistance change rate is less than 50%. ○: Resistance change rate is 50% or more but less than 100%. △: Resistance change rate is 100% or more but less than 300%. ×: Resistance change rate is 300% or more (95°C high temperature environment).
◎: The rate of change in resistance value is less than 20%. ○: The rate of change in resistance value is 20% or more but less than 50%. △: The rate of change in resistance value is 50% or more but less than 100%. ×: The rate of change in resistance value is 100% or more.

As can be seen from Table 2, the adhesive sheet obtained in the example was able to prevent migration in the silver wiring electrode plate and prevent discoloration of the wiring. In addition, the adhesive sheet obtained in the example was able to suppress changes in the resistance value of the silver wiring electrode plate and the ITO vapor deposition film.

The display according to the present invention is suitable, for example, as a capacitive touch panel.

REFERENCE SIGNS LIST 1... Adhesive sheet 11... Adhesive layer 12a, 12b... Release sheet 2... Touch panel 3... Display module 4... Adhesive layer 5a... First film sensor 5b... Second film sensor 51... Substrate film 52... Electrode 6... Cover material 7... Printed layer

Claims (6)

A first display member;
A second display member;
A display body including an adhesive layer that bonds the first display body component and the second display body component to each other,
the first display member and/or the second display member have an electrode formed of a wiring made of a metal or a metal oxide on at least the surface on which the first display member and/or the second display member are bonded;
The wiring width of the wiring is 50 μm or less,
the pressure-sensitive adhesive layer is made of a pressure-sensitive adhesive containing a rust inhibitor and a silane compound,
The rust inhibitor is a benzotriazole-based compound,
a coverage calculated by dividing the pressure-sensitive adhesive volume (μm ³ ) per mm ² in a planar view of the pressure-sensitive adhesive layer by the wiring volume (μm ³ ) per mm ² in a planar view of the wiring is 200 or more and 10,000 or less ;
When the content of the rust inhibitor in the pressure-sensitive adhesive is α% by mass and the thickness of the pressure-sensitive adhesive layer is Z μm, the following formula is satisfied:
0.7≦α×Z≦100
A display characterized by: A first display member;
A second display member;
A display body including an adhesive layer that bonds the first display body component and the second display body component to each other,
the first display member and/or the second display member have an electrode formed of a wiring made of a metal or a metal oxide on at least the surface on which the first display member and/or the second display member are bonded;
The wiring width of the wiring is 50 μm or less,
the pressure-sensitive adhesive layer is made of a pressure-sensitive adhesive containing a rust inhibitor and a silane compound,
The rust inhibitor is a benzotriazole-based compound,
a coverage calculated by dividing the pressure-sensitive adhesive volume (μm ³ ) per mm ² in a planar view of the pressure-sensitive adhesive layer by the wiring volume (μm ³ ) per mm ² in a planar view of the wiring is 200 or more;
The thickness of the pressure-sensitive adhesive layer is 1 μm or more and 200 μm or less,
When the content of the rust inhibitor in the pressure-sensitive adhesive is α% by mass and the thickness of the pressure-sensitive adhesive layer is Z μm, the following formula is satisfied:
0.7≦α×Z≦100
A display characterized by: A first display member;
A second display member;
A display body including an adhesive layer that bonds the first display body component and the second display body component to each other,
the first display member and/or the second display member have an electrode formed of a wiring made of a metal or a metal oxide on at least the surface on which the first display member and/or the second display member are bonded;
the pressure-sensitive adhesive layer is made of an acrylic pressure-sensitive adhesive obtained from a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester polymer and a rust inhibitor;
The (meth)acrylic acid ester polymer contains, as a monomer unit constituting the polymer, 6% by mass or more and 35% by mass or less of a monomer having a hydroxyl group in the molecule,
The rust inhibitor is a benzotriazole-based compound,
a coverage calculated by dividing the pressure-sensitive adhesive volume (μm ³ ) per mm ² in a planar view of the pressure-sensitive adhesive layer by the wiring volume (μm ³ ) per mm ² in a planar view of the wiring is 200 or more and 10,000 or less ;
When the content of the rust inhibitor in the pressure-sensitive adhesive is α% by mass and the thickness of the pressure-sensitive adhesive layer is Z μm, the following formula is satisfied:
0.7≦α×Z≦100
A display characterized by: A first display member;
A second display member;
A display body including an adhesive layer that bonds the first display body component and the second display body component to each other,
the first display member and/or the second display member have an electrode formed of a wiring made of a metal or a metal oxide on at least the surface on which the first display member and/or the second display member are bonded;
the pressure-sensitive adhesive layer is made of an acrylic pressure-sensitive adhesive obtained from a pressure-sensitive adhesive composition containing a (meth)acrylic acid ester polymer and a rust inhibitor;
The (meth)acrylic acid ester polymer contains, as a monomer unit constituting the polymer, 6% by mass or more and 35% by mass or less of a monomer having a hydroxyl group in the molecule,
The rust inhibitor is a benzotriazole-based compound,
a coverage calculated by dividing the pressure-sensitive adhesive volume (μm ³ ) per mm ² in a planar view of the pressure-sensitive adhesive layer by the wiring volume (μm ³ ) per mm ² in a planar view of the wiring is 200 or more;
The thickness of the pressure-sensitive adhesive layer is 1 μm or more and 200 μm or less,
When the content of the rust inhibitor in the pressure-sensitive adhesive is α% by mass and the thickness of the pressure-sensitive adhesive layer is Z μm, the following formula is satisfied:
0.7≦α×Z≦100
A display characterized by: 5. The indicator according to claim 1 , wherein the content of the rust inhibitor in the adhesive is 0.001% by mass or more and 1% by mass or less. 3. The display according to claim 1, wherein the adhesive is an acrylic adhesive.

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