KR102232000B1 - Pressure-sensitive adhesive layer for optical use, pressure-sensitive adhesive sheet, optical component and touch panel - Google Patents

Abstract

The present invention provides an optical member capable of suppressing the occurrence of bending, maintaining high adhesion reliability and transparency, and excellent anti-corrosion effect, and a pressure-sensitive adhesive layer and a pressure-sensitive adhesive sheet capable of efficiently and inexpensively manufacturing such an optical member.
The present invention contains a base polymer and a rust inhibitor, the base polymer does not contain or substantially does not contain an acidic group-containing monomer as a constituent monomer component, and an optical ^{modulus of at least 5.0×10 4 Pa at 85°C.} It provides a pressure-sensitive adhesive layer.

Description

Optical adhesive layer, adhesive sheet, optical member and touch panel {PRESSURE-SENSITIVE ADHESIVE LAYER FOR OPTICAL USE, PRESSURE-SENSITIVE ADHESIVE SHEET, OPTICAL COMPONENT AND TOUCH PANEL}

The present invention relates to an optical pressure-sensitive adhesive layer, a pressure-sensitive adhesive sheet, an optical member, and a touch panel.

In recent years, display devices such as liquid crystal displays (LCDs) and input devices such as touch panels are widely used in various fields. In manufacturing of these display devices and input devices, a pressure-sensitive adhesive sheet is used for bonding optical members. For example, in various display devices such as a touch panel, a transparent adhesive sheet is used for bonding of optical members.

In these display devices and input devices, there is a problem that metal wiring is corroded by invading moisture, acidic gas, saline, and corrosive components from the external environment into the interior. In recent years, with the increase of the size of the sensor or the narrowing of the frame, the number of examples provided with copper wiring is increasing. Copper, after silver, has excellent electrical conductivity and is a useful material for wiring, but is known to be susceptible to oxidation and corrosion. In general, for the purpose of preventing metal oxidation and corrosion, a method of preventing intrusion of moisture or corrosive components by coating a moisture-proof protective layer on metal wiring is used (Patent Document 1).

Japanese Patent Application Publication No. 2011-28594

However, the coating needs to be performed after the metal wiring is formed, and since the number of steps increases and labor is required, it has become a major problem in terms of a reduction in manufacturing yield and cost. In addition, in the case of using a moisture-proof protective layer, there are problems in securing adhesion reliability and transparency such as adhesion and foaming and peeling resistance (a characteristic where foaming or peeling is difficult to occur at the interface between the adhesive sheet and the adherend in a high temperature environment). Something happened.

In addition, when a pattern is formed on the metal film in a laminate having a structure in which a metal film is stacked on a support, a patterned portion (pattern forming portion) and a patterned portion (pattern opening portion) are formed. In the case where such a metal film pattern is formed, there is a case where a warp occurs in the laminate under a high temperature environment due to a difference in linear expansion coefficient between the material constituting the support and the metal constituting the metal film. In addition, when such a bend occurs, the problem of deteriorating aesthetics tends to occur. This is because the step difference at the boundary between the pattern forming portion and the pattern opening (hereinafter, also referred to as "pattern boundary") becomes larger than necessary, and the pattern boundary becomes easily visually recognized.

Accordingly, it is an object of the present invention to suppress the occurrence of bending in a high-temperature environment, and adhesion reliability such as adhesion and foam-resistance (a characteristic that is difficult to cause foaming or peeling at the interface between an adhesive sheet and an adherend in a high-temperature environment). , An optical member (particularly, an optical member with a pressure-sensitive adhesive sheet) excellent in anti-corrosion effect of metal wiring such as copper wiring while maintaining high transparency, and an optical pressure-sensitive adhesive layer and adhesive that can efficiently and low-cost manufacture such optical members It is in providing a sheet.

Therefore, as a result of intensive study by the present inventors in order to solve the above problems, by using an appropriate one as a base polymer constituting the pressure-sensitive adhesive layer and using a rust inhibitor, adhesion reliability, transparency, and anti-corrosion effects can be provided, and further By controlling the elastic modulus at high temperature in the pressure-sensitive adhesive composition, it was found that the occurrence of bending in a high temperature environment can be suppressed, and the present invention was completed.

In particular, the present invention was completed by finding out that a synergistic effect on the anti-corrosion effect was obtained by not containing or substantially containing an acidic group-containing monomer as a monomer component constituting the base polymer, and using a rust inhibitor.

That is, the present invention contains a base polymer and a rust inhibitor, does not contain or substantially does not contain an acidic group-containing monomer as a monomer component constituting the base polymer, and has an elastic modulus of 5.0×10 ⁴ Pa or more at 85°C. It provides an optical pressure-sensitive adhesive layer.

In addition, the present invention contains an acrylic polymer (A) and a rust inhibitor as main components, does not contain or substantially does not contain a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A), and the elastic modulus at 85°C is 5.0× It provides an optical pressure-sensitive adhesive layer, characterized in that ^{10 4 Pa or more.}

The optical pressure-sensitive adhesive layer preferably contains 5 parts by weight or more of a hydroxyl group-containing monomer with respect to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A).

The optical pressure-sensitive adhesive layer preferably contains 5 parts by weight or more of a nitrogen atom-containing monomer with respect to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A).

It is preferable that the rust inhibitor is a benzotriazole-based compound.

It is preferable that the said optical pressure-sensitive adhesive layer has a haze (according to JIS K7136) of 1.0% or less.

It is preferable that the optical pressure-sensitive adhesive layer has a total light transmittance (according to JIS K7361-1) of 90% or more.

In addition, the present invention provides a pressure-sensitive adhesive sheet having the optical pressure-sensitive adhesive layer.

It is preferable that the pressure-sensitive adhesive sheet has a 180° peel adhesion to the glass plate of 8N/20mm or more.

It is preferable that the pressure-sensitive adhesive sheet has a thickness of 12 to 350 μm.

In addition, the present invention is an optical member having at least the pressure-sensitive adhesive sheet and a substrate, wherein the substrate is provided with a metal wiring on at least one side, and the pressure-sensitive adhesive sheet is adhered on the side of the substrate having the metal wiring. Provide absence.

In the optical member, it is preferable that the metal wiring is a copper wiring.

In addition, the present invention is a touch panel having at least the pressure-sensitive adhesive sheet and a substrate, wherein the substrate has a metal wire on at least one side, and the pressure-sensitive adhesive sheet is adhered on the side of the substrate having the metal wire Provide a panel.

In the touch panel, it is preferable that the metal wiring is a copper wiring.

According to the optical pressure-sensitive adhesive layer of the present invention, since it can have adhesion reliability, transparency, and anti-corrosion effect, metal wiring such as copper wiring while maintaining high adhesion reliability, such as adhesion and foaming and peeling resistance, and transparency An optical member having an excellent anti-corrosion effect of, and a pressure-sensitive adhesive layer and a pressure-sensitive adhesive sheet enabling the production of such an optical member are obtained. In addition, by imparting a corrosion-preventing ability to the pressure-sensitive adhesive layer, coating of the protective layer is unnecessary and the process is reduced, thereby reducing cost and improving yield.

Further, according to the pressure-sensitive adhesive layer for optics of the present invention, an optical member having good aesthetics, and a pressure-sensitive adhesive layer and a pressure-sensitive adhesive sheet that enable production of such an optical member can be obtained because it is possible to suppress the occurrence of bending in a high-temperature environment.

1 is a schematic diagram showing a specific example of a preferred embodiment of an optical member according to the present invention.
2 is a schematic diagram showing a specific example of a preferred embodiment of the touch panel according to the present invention.
Fig. 3 is a top view of a glass in which a step difference is formed used in evaluation of foaming and peeling resistance.
4 is a cross-sectional view (a cross-sectional view taken along line A-A') of the glass in which the step difference is formed.
5 is a cross-sectional view (a cross-sectional view taken along line B-B') of the glass in which the step difference is formed.
Fig. 6 is a schematic cross-sectional view showing an example of a laminate comprising a support and a metal film in which a bend has occurred.
7 is a schematic plan view showing an example of a metal wiring pattern.

1. Optical adhesive layer

The optical pressure-sensitive adhesive layer of the present invention contains a base polymer and a rust inhibitor as main components, the base polymer does not contain or substantially does not contain an acidic group-containing monomer as a constituent monomer component, and has an elastic modulus of 5.0×10 ^{4 at 85°C.} It may be Pa or more, and it is not specifically limited in other points. In addition, the pressure-sensitive adhesive composition of the present invention contains at least a base polymer and a rust inhibitor.

The optical pressure-sensitive adhesive layer of the present invention does not contain or substantially does not contain an acidic group-containing monomer as a monomer component constituting the base polymer, and further contains a rust inhibitor, thereby obtaining a synergistic effect on the anti-corrosion effect, and is excellent. It has anti-corrosion effect.

Further, the optical pressure-sensitive adhesive layer of the present invention contains an acrylic polymer (A) as a main component and a rust inhibitor, and the acrylic polymer (A) does not contain or substantially does not contain a carboxyl group-containing monomer as a constituent monomer component. The modulus of elasticity ^{may be 5.0×10 4} Pa or more.

The composition (adhesive composition, precursor composition) forming the optical pressure-sensitive adhesive layer of the present invention may have any form, for example, an emulsion type, a solvent type, a heat melting type (hot melt type), an active energy ray curing type, etc. Can be lifted. In addition, in the present specification, the pressure-sensitive adhesive composition refers to a composition for forming a pressure-sensitive adhesive layer, and includes a composition for forming a pressure-sensitive adhesive.

The base polymer contained in the optical pressure-sensitive adhesive layer of the present invention is not particularly limited, but, for example, an acrylic polymer in which the acrylic pressure-sensitive adhesive layer is contained as a base polymer, and a rubber-based pressure-sensitive adhesive layer (natural rubber-based pressure-sensitive adhesive layer, synthetic rubber-based pressure-sensitive adhesive layer, etc.) The rubber-based polymer contained as the base polymer, the silicone-based polymer containing the silicone-based adhesive layer as the base polymer, the polyester-based polymer containing the polyester-based adhesive layer as the base polymer, and the urethane-based polymer containing the urethane-based adhesive layer as the base polymer, poly Polyamide-based polymer in which an amide-based adhesive layer is contained as a base polymer, epoxy-based polymer in which an epoxy-based adhesive layer is contained as a base polymer, a vinyl alkyl ether-based polymer containing a vinylalkyl ether-based adhesive layer as a base polymer, and a fluorine-based adhesive layer Fluorine-based polymers and the like contained as this base polymer are mentioned. Among them, the base polymer is preferably an acrylic polymer from the viewpoints of transparency, weather resistance, adhesion reliability, and a variety of monomers to facilitate functional design of the pressure-sensitive adhesive layer. That is, it is preferable that the adhesive layer for optics of this invention is an acrylic adhesive layer containing an acrylic polymer (A) mentioned later as a base polymer. In addition, the base polymer may be used alone or in combination of two or more.

Although the content of the base polymer in the optical pressure-sensitive adhesive layer of the present invention is not particularly limited, it is preferably 75% by weight or more (for example, 75 to 99.9% by weight), and more preferably 85% by weight or more (for example, For example, 85 to 99.9% by weight).

The optical pressure-sensitive adhesive layer of the present invention does not contain or substantially does not contain an acidic group-containing monomer (eg, a carboxyl group-containing monomer, a sulfo group-containing monomer, a phosphoric acid group-containing monomer, etc.). For this reason, an excellent anti-corrosion effect of the metal wiring can be obtained. In addition, the content of the acidic group-containing monomer is preferably 0.05% by weight or less (for example, 0 to 0.05% by weight), more preferably 0.01% by weight or less (for example, with respect to the optical pressure-sensitive adhesive layer of the present invention). , 0 to 0.01% by weight), more preferably 0.001% by weight or less (for example, 0 to 0.001% by weight) can be said to be substantially not contained.

When the optical pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer, the optical pressure-sensitive adhesive layer of the present invention is a monomer component constituting an acrylic polymer contained as a base polymer, and does not contain an acidic group-containing monomer such as a carboxyl group-containing monomer, or It does not contain substantially. When the optical pressure-sensitive adhesive layer of the present invention contains an acrylic polymer (A) as a base polymer, it is more preferable that it does not contain or substantially does not contain a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A). For this reason, the optical pressure-sensitive adhesive layer of the present invention can obtain an excellent anti-corrosion effect. The meaning of the carboxyl group-containing monomer, the meaning of "substantially not contained", and the monomer having an acidic group other than a carboxyl group are the same as those in the case of the monomer component constituting the acrylic polymer (A). In addition, the content of the carboxyl group-containing monomer is preferably 0.05% by weight or less (for example, 0 to 0.05% by weight), more preferably 0.01% by weight or less (for example, with respect to the total amount of the optical pressure-sensitive adhesive layer of the present invention). , 0 to 0.01% by weight), more preferably 0.001% by weight or less (for example, 0 to 0.001% by weight) can be said to be substantially not contained.

The optical pressure-sensitive adhesive layer of the present invention is transparent or has transparency. For this reason, it is excellent in visibility and appearance through the optical pressure-sensitive adhesive layer of the present invention.

The haze (according to JIS K7136) of the optical pressure-sensitive adhesive layer of the present invention is not particularly limited, but is preferably 1.0% or less, and more preferably 0.8% or less. When the haze is 1.0% or less, excellent transparency and excellent appearance are obtained, which is preferable. In addition, the haze is, for example, a pressure-sensitive adhesive layer (thickness: 100 μm), and after leaving it in a steady state (23° C., 50% RH) for at least 24 hours, slide glass (eg, 91.8% total light transmittance) , A haze of 0.4%) as a sample, and it can be measured using a haze meter (manufactured by Murakami Shikisai Kijutsu Kenkyusho Co., Ltd., brand name "HM-150").

Although the total light transmittance (according to JIS K7361-1) in the visible light wavelength range of the optical pressure-sensitive adhesive layer of the present invention is not particularly limited, it is preferably 85% or more, and more preferably 88% or more. When the total light transmittance is 85% or more, excellent transparency and excellent appearance are obtained, which is preferable. In addition, the total light transmittance is, for example, a pressure-sensitive adhesive layer (thickness: 100 μm), and after leaving it in a steady state (23° C., 50% RH) for at least 24 hours, in the case of having a separator, it is peeled off, and the slide A sample bonded to glass (e.g., 91.8% total light transmittance, 0.4% haze) can be used as a sample and measured using a haze meter (manufactured by Murakami Shikisai Kijutsu Kenkyusho Co., Ltd., brand name ``HM-150''). have.

In the optical pressure-sensitive adhesive layer of the present invention, the elastic modulus at 85° C. is 5.0×10 ⁴ Pa or more, more preferably 7.0×10 ⁴ Pa or more, and still more preferably 9.0×10 ⁴ Pa or more. Since the optical pressure-sensitive adhesive layer of the present invention has an elastic modulus at 85° C. of 5.0×10 ⁴ Pa or more, the occurrence of bending can be suppressed. For this reason, according to the pressure-sensitive adhesive layer for optics of the present invention, an optical member or a touch panel having good aesthetics can be obtained. This is because it is possible to suppress the occurrence of so-called "pattern appearance" (a phenomenon in which the step difference at the pattern boundary becomes larger than necessary and the pattern boundary becomes more easily visually recognized, resulting in a deteriorating aesthetic appearance).

The measurement for the 85°C elastic modulus is obtained as follows. After making the pressure-sensitive adhesive layer (thickness: about 2 mm), it is punched out to a φ 7.9 mm, and a cylindrical pellet is produced, which is used as a sample for measurement. The measurement sample is fixed to a jig of a phi 7.9 mm parallel plate, and the temperature dependence of the storage elastic modulus G'is measured by a dynamic viscoelasticity measuring device (manufactured by Rheometrics, ARES). That is, measurement: shear mode, temperature range: -70°C to 150°C, temperature rise rate: 5°C/min, frequency: 1 Hz, it refers to the storage modulus (G') at 85°C.

6 shows a schematic cross-sectional view of an example of a laminate comprising a support and a metal film (a laminate having a metal film pattern on the support) in which the warp has occurred in relation to the warp. In Fig. 6, 6 is a laminate, 61 is a support, and 62 is a metal film (metal film pattern). In this way, "curve" means to bend or wave.

The method for producing the optical pressure-sensitive adhesive layer is not particularly limited. For example, it can be produced by preparing the pressure-sensitive adhesive composition and, if necessary, irradiation with active energy rays, heat drying, or the like. Specifically, to a polymerizable monomer mixture or a partial polymer thereof, a rust inhibitor (for example, the following benzotriazole-based compound, etc.), additives, etc. are added and mixed as needed, and the like is prepared through the process of mixing. .

The optical pressure-sensitive adhesive layer of the present invention contains a rust inhibitor. Rust inhibitors include compounds that prevent rust or corrosion of metals. Although it does not specifically limit as a rust inhibitor, For example, an amine compound, a benzotriazole type compound, nitrite, etc. are mentioned. In addition, ammonium benzoate, ammonium phthalate, ammonium stearate, ammonium palmitate, ammonium oleate, ammonium carbonate, dicyclohexylamine benzoate, urea, urotropine, thiourea, phenyl carbamate, cyclohexyl ammonium-N- And cyclohexylcarbamate (CHC). In addition, rust inhibitors can be used alone or in combination of two or more.

Examples of the amine compound include hydroxy group-containing amine compounds such as 2-amino-2-methyl-1-propanol, monoethanolamine, monoisopropanolamine, diethylethanolamine, and ammonia or aqueous ammonia; Cyclic amines such as morpholine; Cyclic alkylamine compounds such as cyclohexylamine; Linear alkylamines, such as 3-methoxypropylamine, etc. are mentioned. Further, examples of nitrites include dicyclohexylammonium nitrite (DICHAN), diisopropylammonium nitrite (DIPAN), sodium nitrite, potassium nitrite, and calcium nitrite.

Among them, a benzotriazole-based compound is preferred in that the rust inhibitor is difficult to inhibit the reaction (crosslinking, polymerization, etc.) of the base polymer when reacting the base polymer after addition, in terms of compatibility and transparency with the base polymer. Do.

Although the content of the rust inhibitor is not particularly limited, it is preferable to include 0.02 to 15 parts by weight based on 100 parts by weight of the base polymer. When the content is not less than 0.02 parts by weight, good corrosion-preventing performance can be easily obtained, and it is preferable. On the other hand, if the content is less than 15 parts by weight, transparency is easily secured, and adhesion reliability such as foaming and peeling resistance is easily secured, which is preferable.

In particular, the base polymer is an acrylic polymer (particularly an acrylic polymer (A) to be described later), and the rust inhibitor is a benzotriazole-based compound in that the properties of adhesion reliability, transparency, and corrosion protection can be obtained in a balanced and high level. It is desirable. That is, the optical pressure-sensitive adhesive layer of the present invention is preferably an acrylic pressure-sensitive adhesive layer containing at least an acrylic polymer as a base polymer (particularly, an acrylic polymer (A) to be described later) and a benzotriazole-based compound as a rust inhibitor.

1-1. Benzotriazole compounds

Although the content of the benzotriazole-based compound is not particularly limited, it is preferably 0.02 to 3 parts by weight, more preferably 0.02 to 2.5 parts by weight, based on the total amount (100 parts by weight) of the monomer component constituting the acrylic polymer (A). , More preferably 0.02 to 2 parts by weight. That is, the optical pressure-sensitive adhesive layer of the present invention preferably contains 0.02 to 3 parts by weight of a benzotriazole-based compound, more preferably 0.02 to 2.5 parts by weight, and 0.02 to 100 parts by weight of the acrylic polymer (A). It is more preferable to include to 2 parts by weight. When the amount of the benzotriazole-based compound is too small, the value of the rate of change (T) of the sheet resistivity may not be less than a predetermined value. In addition, since the amount of the benzotriazole-based compound is not more than a certain level, adhesion reliability such as foaming and peeling resistance can be reliably secured, and an increase in haze of the pressure-sensitive adhesive layer or the pressure-sensitive adhesive sheet can also be reliably prevented.

The benzotriazole-based compound is not particularly limited as long as it is a compound having a benzotriazole skeleton, but a compound having a structure represented by the following formula (1) is preferable from the viewpoint of obtaining a more excellent anti-corrosion effect.

(However, in the above formula (1), R ¹ and R ² are the same or different, R ¹ is a substituent on a benzene ring, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and 6 to 14 carbon atoms an aryl group, an amino group, a mono- or di-C _{1 - 10} alkyl group, amino -C _{1 - 6} alkyl group, a mono- or di-C _{1 - 10} alkyl, amino -C _{1 - 6} alkyl group, a mercapto group, an alkoxy group having 1 to 6 carbon atoms Represents a substituent such as, n is an integer of 0 to 4, and when n is 2 or more, n R ^1s may be the same or different, and R ² is a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, the number of carbon atoms of from 1 to 12 alkoxy groups, aryl groups having 6 to 14, an amino group, a mono- or di-C _{1 - 10} alkyl group, amino -C _{1 - 6} alkyl group, a mono- or di-C _{1 - 10} alkyl, amino -C _{1 - 6} Represents a substituent such as an alkyl group, a mercapto group, or an alkoxycarbonyl group having 1 to 12 carbon atoms)

From the viewpoint of obtaining a more excellent anti-corrosion effect, R ¹ is preferably an alkyl group having 1 to 3 carbon atoms, an alkoxycarbonyl group and the like, and more preferably a methyl group and the like. Further, n is preferably 0 or 1.

In the same aspect, R ² a hydrogen atom, a mono- or di-C _{1 - 4} alkyl group is more preferred such as ₁₀ alkylamino -C _{1 - 6} alkyl group is preferably a hydrogen atom, and di-C _{1 - 8} alkylamino -C ₁ Do.

1-2. Acrylic polymer (A)

It is preferable that the adhesive layer for optics of this invention is an acrylic adhesive layer containing an acrylic polymer (A) as a main component. Although the specific content of the acrylic polymer (A) is not particularly limited, it is preferably 75% by weight or more (for example, 75 to 99.9% by weight) based on the total amount (100% by weight) of the optical pressure-sensitive adhesive layer of the present invention. And more preferably 85% by weight or more (eg, 85 to 99.9% by weight).

Although it does not specifically limit as a pressure-sensitive adhesive composition for forming an optical pressure-sensitive adhesive layer containing an acrylic polymer (A) as a main component, for example, a composition containing an acrylic polymer (A) as an essential component; A mixture of monomer components constituting the acrylic polymer (A) (sometimes referred to as a "monomer mixture") or a composition containing a partial polymerized product thereof as an essential component may be mentioned. Although it does not specifically limit, For example, a so-called solvent-type composition etc. are mentioned as a former, For example, a so-called active energy ray-curable composition etc. are mentioned as a latter. In addition, the pressure-sensitive adhesive composition may contain other additives as necessary.

The term "monomer mixture" shall include a case where it is composed of a single monomer component and a case where it is composed of two or more monomer components. In addition, the "partially polymerized product" means a composition in which one or two or more components of the constituent components of the monomer mixture are partially polymerized. Among them, the pressure-sensitive adhesive composition is preferably a composition containing a monomer mixture or a partial polymer thereof as an essential component.

The acrylic polymer (A) is a polymer (polymer) containing an acrylic monomer (acrylic monomer) as an essential monomer unit (monomer unit, monomer structural unit). In other words, the acrylic polymer (A) is a polymer containing a structural unit derived from an acrylic monomer as a structural unit. That is, the acrylic polymer (A) is a polymer constituted (formed) by using an acrylic monomer as an essential monomer component. In addition, in this specification, "(meth)acryl" represents either or both of "acrylic" and "methacryl", and others are also the same. The weight average molecular weight of the acrylic polymer (A) is not particularly limited, but it is preferably 100,000 to 5,000,000.

It is preferable that the acrylic polymer (A) is a polymer containing as an essential monomer unit, an alkyl (meth)acrylate having a linear or branched alkyl group (hereinafter, simply referred to as ``alkyl (meth)acrylate)''. .

Examples of the alkyl (meth)acrylate ester include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, and butyl (meth)acrylate ((meth)acrylate n- Butyl), isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate , Octyl (meth)acrylate, (meth)2-ethylhexyl acrylate, Isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate , Undecyl (meth)acrylate, Dodecyl (meth)acrylate, Tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, (Meth)acrylate alkyl esters having 1 to 20 carbon atoms in an alkyl group such as octadecyl (meth)acrylate, isostearyl (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate. In addition, alkyl (meth)acrylates may be used alone or in combination of two or more.

Among them, the alkyl (meth)acrylate is preferably an alkyl (meth)acrylate having 1 to 18 carbon atoms in the alkyl group from the viewpoint of obtaining strong adhesiveness and adjusting the residual stress, and more preferably methylmethacrylate. They are acrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), and isostearyl acrylate (ISTA).

Although the content (ratio) of the alkyl (meth)acrylate in the total monomer units of the acrylic polymer (A) (the total amount of the monomer components constituting the acrylic polymer (A)) is not particularly limited, adhesion reliability, particularly adhesion reliability at low temperatures In terms of aspect, with respect to the total amount (100 parts by weight) of the monomer component constituting the acrylic polymer (A), 30 to 95 parts by weight is preferable, more preferably 35 to 90 parts by weight, still more preferably 40 to 85 parts by weight. .

The acrylic polymer (A) may contain a monomer (copolymerizable monomer) capable of copolymerization in addition to the above alkyl (meth)acrylate as a monomer unit. That is, the acrylic polymer (A) may contain a copolymerizable monomer as a constituent monomer component. Further, the copolymerizable monomer may be used alone or in combination of two or more.

As the copolymerizable monomer, a hydroxyl group-containing monomer is preferably exemplified. When the acrylic polymer (A) contains a hydroxyl group-containing monomer as a monomer unit, polymerization becomes easy when the constituting monomer component is polymerized, and a good cohesive force is easily obtained. For this reason, it becomes easy to obtain strong adhesiveness, and further increases the gel fraction, and it becomes easy to obtain excellent foaming and peeling resistance. In addition, it becomes easy to suppress whitening of the pressure-sensitive adhesive sheet which may occur in a high humidity environment.

The content (ratio) of the hydroxyl group-containing monomer relative to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A) is not particularly limited. When the amount of the hydroxyl group-containing monomer is more than a certain level, whitening of the pressure-sensitive adhesive sheet that may occur under a high humidity environment can be further suppressed, and transparency such as humidification whitening resistance can be secured. The lower limit of the content of the hydroxyl group-containing monomer is preferably 5 parts by weight or more, more preferably 7 parts by weight or more, and still more preferably 10 parts by weight or more. In addition, the upper limit of the content of the hydroxyl group-containing monomer is preferably 40 parts by weight or less, more preferably 35 parts by weight or less, in terms of cohesive strength, adhesion, foaming and peeling resistance, etc. It is more preferable that it is not more than parts by weight.

Further, as the copolymerizable monomer, a nitrogen atom-containing monomer is preferably exemplified. When the acrylic polymer (A) contains a nitrogen atom-containing monomer as a monomer unit, it becomes easy to obtain an appropriate cohesive force. For this reason, by increasing the 180° peeling adhesion to the glass plate and the 180° peeling adhesion to the acrylic plate, it becomes easy to obtain strong adhesiveness, and further increases the gel fraction, thereby making it easier to obtain excellent foaming and peeling resistance. In addition, it becomes easy to obtain appropriate flexibility in the pressure-sensitive adhesive layer, adjusts the 300% tensile residual stress within a specific range, and makes it easy to obtain excellent stress relaxation properties and excellent step followability.

Although the content (ratio) of the nitrogen atom-containing monomer with respect to the total amount (100 parts by weight) of the monomer component constituting the acrylic polymer (A) is not particularly limited, it is preferably 5 parts by weight or more. The lower limit of the content of the nitrogen atom-containing monomer is more preferably 7 parts by weight or more with respect to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A) from the viewpoints of cohesive strength, adhesiveness, and foaming and releasability, More preferably, it is 10 parts by weight or more. In addition, the upper limit of the content of the nitrogen atom-containing monomer is preferably 40 parts by weight or less, and 35 parts by weight, from the viewpoint of further obtaining an appropriate flexibility in the pressure-sensitive adhesive layer, and further obtaining excellent stress relaxation properties and excellent step followability. It is more preferable that it is below, and it is still more preferable that it is 30 parts by weight or less.

The acrylic polymer (A) can be obtained by polymerizing the monomer unit (monomer component) by a known or common polymerization method. Examples of the polymerization method of the acrylic polymer (A) include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method by irradiation with active energy rays (active energy ray polymerization method). Among them, from the viewpoints of transparency, water resistance, cost, etc. of the pressure-sensitive adhesive layer, a solution polymerization method and an active energy ray polymerization method are preferable, and an active energy ray polymerization method is more preferable.

The active energy rays irradiated during the polymerization (photopolymerization) of the active energy rays include, for example, ionizing radiation such as α-rays, β-rays, γ-rays, neutron rays, and electron beams, ultraviolet rays, and the like. This is desirable. Moreover, the irradiation energy, irradiation time, irradiation method, etc. of an active energy ray are not specifically limited, What is necessary is just to be able to generate|occur|produce reaction of a monomer component by activating a photoinitiator.

In the polymerization of the acrylic polymer (A), various general solvents may be used. Examples of such a solvent include esters such as ethyl acetate and n-butyl acetate; Aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; Alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; Organic solvents, such as ketones, such as methyl ethyl ketone and methyl isobutyl ketone, are mentioned. In addition, the solvent may be used alone or in combination of two or more.

In addition, in the polymerization of the acrylic polymer (A), a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) may be used depending on the type of polymerization reaction. Further, the polymerization initiator may be used alone or in combination of two or more.

Although it does not specifically limit as said photoinitiator, For example, a benzoin ether-type photoinitiator, acetophenone-type photoinitiator, α-ketol-type photoinitiator, aromatic sulfonyl chloride-type photoinitiator, photoactive oxime-type photoinitiator, benzo A phosphorus photoinitiator, a benzyl photoinitiator, a benzophenone photoinitiator, a ketal photoinitiator, a thioxanthone photoinitiator, etc. are mentioned. Moreover, a photoinitiator can also be used individually or in combination of 2 or more types.

Examples of the benzoin ether-based photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2 -Diphenylethan-1-one, anisole methyl ether, etc. are mentioned. Examples of the acetophenone-based photoinitiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, and 4-phenoxydichloroacetophenone And 4-(t-butyl)dichloroacetophenone. Examples of the α-ketol-based photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, and the like. Can be lifted. Examples of the aromatic sulfonyl chloride-based photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime and the like. Examples of the benzoin-based photopolymerization initiator include benzoin and the like. Examples of the benzyl-based photoinitiator include benzyl and the like. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3, 3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenylketone, and the like. . Examples of the ketal-based photopolymerization initiator include benzyl dimethyl ketal and the like. Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chloro thioxanthone, 2-methyl thioxanthone, 2,4-dimethyl thioxanthone, isopropyl thioxanthone, 2,4- Diisopropyl thioxanthone, dodecyl thioxanthone, etc. are mentioned.

Although the amount of the photopolymerization initiator is not particularly limited, for example, 0.001 to 1 part by weight is preferable based on 100 parts by weight of the total monomer units of the acrylic polymer (A) (the total amount of the monomer components constituting the acrylic polymer (A)). , More preferably 0.01 to 0.50 parts by weight.

In addition, the thermal polymerization initiator is not particularly limited, but, for example, an azo polymerization initiator, a peroxide polymerization initiator (e.g., dibenzoyl peroxide, tert-butyl permalate, etc.), a redox polymerization initiator And the like. Among them, the azo polymerization initiator disclosed in Japanese Patent Laid-Open No. 2002-69411 is preferable. Examples of the azo polymerization initiator include 2,2'-azobisisobutyronitrile (hereinafter sometimes referred to as ``AIBN''), 2,2'-azobis-2-methylbutyronitrile (hereinafter, ``AMBN "), 2,2'-azobis(2-methylpropionic acid)dimethyl, 4,4'-azobis-4-cyanovaleric acid, etc. are mentioned.

Although the amount of the thermal polymerization initiator is not particularly limited, for example, in the case of the azo polymerization initiator, 100 parts by weight of the total monomer units of the acrylic polymer (A) (the total amount of the monomer components constituting the acrylic polymer (A)) On the other hand, it is preferably 0.05 to 0.5 parts by weight, more preferably 0.1 to 0.3 parts by weight.

1-3. Carboxyl group-containing monomer, etc.

The optical pressure-sensitive adhesive layer of the present invention does not contain or substantially does not contain an acidic group-containing monomer as a monomer component constituting the base polymer. When the optical pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer, it is preferable that the optical pressure-sensitive adhesive layer of the present invention is a monomer component constituting the acrylic polymer (A) and does not substantially contain a carboxyl group-containing monomer. In addition, "substantially not contained" refers to not being actively blended except in the case of unavoidable mixing. In addition, the carboxyl group-containing monomer means a monomer having at least one carboxyl group in the molecule. From the viewpoint of obtaining a more excellent anti-corrosion effect, specifically, the content of the carboxyl group-containing monomer is 0.05 parts by weight or less (for example, 0 parts by weight) based on the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A). To 0.05 parts by weight), more preferably 0.01 parts by weight or less (for example, 0 to 0.01 parts by weight), more preferably 0.001 parts by weight or less (for example, 0 to 0.001 parts by weight) It can be said that it does not contain substantially. Further, examples of the carboxyl group-containing monomer include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid, and the carboxyl group-containing monomer includes, for example, maleic anhydride. And acid anhydride group-containing monomers such as itaconic anhydride are also included.

In addition, when the optical pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer, from the viewpoint of obtaining a more excellent anti-corrosion effect, the optical pressure-sensitive adhesive layer of the present invention contains a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A). As a monomer component constituting the acrylic polymer (A), it is preferable not to contain substantially a monomer having an acidic group other than a carboxyl group (sulfo group, phosphoric acid group, etc.). That is, it is preferable that the acrylic polymer (A) preferably does not substantially contain both a carboxyl group-containing monomer and another acidic group-containing monomer as a constituting monomer component. Specifically, the total amount of the carboxyl group-containing monomer and other acidic group-containing monomers as monomer components constituting the acrylic polymer (A) is 0.05 weight based on the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A). Parts or less (for example, 0 to 0.05 parts by weight) is preferable, more preferably 0.01 parts by weight or less (for example, 0 to 0.01 parts by weight), more preferably 0.001 parts by weight or less (for example, 0 to 0.001 parts by weight) can be said to be substantially not contained.

In addition, from the same viewpoint, the optical pressure-sensitive adhesive layer of the present invention does not contain an acidic group-containing monomer as a monomer component constituting a polymer other than the acrylic polymer (A) (for example, an acrylic polymer (B) to be described later). It is preferred that it does not contain or does not contain substantially. For example, it is preferable that it does not contain a carboxyl group-containing monomer substantially. In addition, the meaning of "substantially not contained", a preferable degree, and a monomer having an acidic group other than a carboxyl group are the same as those of the monomer component constituting the acrylic polymer (A).

1-4. Basic group-containing monomer

Further, the optical pressure-sensitive adhesive layer of the present invention is a monomer component constituting the base polymer, and preferably does not contain or substantially does not contain a basic group-containing monomer. For example, when the optical pressure-sensitive adhesive layer of the present invention is an acrylic pressure-sensitive adhesive layer containing an acrylic polymer (A) as a base polymer, a basic group-containing monomer is substantially included as a monomer component constituting a polymer other than the acrylic polymer (A). It is preferable not to contain, and even when it is not a monomer component constituting various polymers, the point that it is preferable not to substantially contain a basic group-containing monomer in the pressure-sensitive adhesive layer is the same as in the case of a carboxyl group-containing monomer. In addition, the meaning of "substantially not contained", a preferable degree, etc. shall be the same.

1-5. Hydroxyl-containing monomer

The hydroxyl-containing monomer means a monomer having at least one hydroxyl group in the molecule. In addition, a monomer having at least one hydroxyl group in the molecule and at least one carboxyl group in the molecule is a carboxyl group-containing monomer and is not a hydroxyl group-containing monomer. Although it does not specifically limit as said hydroxyl-containing monomer, Specifically, For example, (meth)acrylate 2-hydroxyethyl, (meth)acrylate 2-hydroxypropyl, (meth)acrylate 2-hydroxybutyl, ( 3-hydroxypropyl meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, hydroxydecyl (meth)acrylate Hydroxyl group-containing (meth)acrylic acid esters such as hydroxylauryl and (meth)acrylic acid (4-hydroxymethylcyclohexyl); Vinyl alcohol, allyl alcohol, etc. are mentioned. Among them, the hydroxyl group-containing monomer is preferably a hydroxyl group-containing (meth)acrylic acid ester, more preferably 2-hydroxyethyl acrylate (HEA), 2- Hydroxypropyl (meth)acrylate (HPA), 4-hydroxybutyl acrylate (4HBA). Further, the hydroxyl group-containing monomer may be used alone or in combination of two or more.

1-6. Nitrogen atom containing monomer

The nitrogen atom-containing monomer means a monomer having at least one nitrogen atom in a molecule (in one molecule). However, it is assumed that the nitrogen atom-containing monomer is not contained in the hydroxyl group-containing monomer. That is, in the present specification, a monomer having a hydroxyl group and a nitrogen atom in the molecule is assumed to be included in the nitrogen atom-containing monomer. In addition, a monomer having at least one nitrogen atom in the molecule and at least one carboxyl group in the molecule is a carboxyl group-containing monomer and is not a nitrogen atom-containing monomer.

As the nitrogen atom-containing monomer, N-vinyl cyclic amides, (meth)acrylamides, and the like are preferable from the viewpoint of improving foaming and releasability. Further, the nitrogen atom-containing monomer may be used alone or in combination of two or more.

As the N-vinyl cyclic amide, N-vinyl cyclic amide represented by the following formula (2) is preferable from the viewpoint of improving the compatibility of the benzotriazole-based compound.

(In formula (2), R ³ represents a divalent organic group)

In the above formula (2), R ³ is a divalent organic group, preferably a divalent saturated hydrocarbon group or an unsaturated hydrocarbon group, and more preferably a divalent saturated hydrocarbon group (e.g., an alkyl having 3 to 5 carbon atoms). Rengi, etc.).

The N-vinyl cyclic amide represented by the above formula (2) further includes N-vinyl-2-pyrrolidone (NVP), N-vinyl from the viewpoint of improving foaming and releasability and compatibility of the benzotriazole-based compound. -2-piperidone, N-vinyl-2-caprolactam, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-vinyl-3-morpholinone, N- Vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, etc. are preferable, more preferably N-vinyl-2-pyrrolidone, N-vinyl-2-capro Lactam, N,N-dimethyl(meth)acrylamide, and N,N-diethyl(meth)acrylamide, more preferably N-vinyl-2-pyrrolidone.

Examples of the (meth)acrylamides include (meth)acrylamide, N-alkyl (meth)acrylamide, and N,N-dialkyl (meth)acrylamide. Examples of the N-alkyl (meth)acrylamide include N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, Nn-butyl (meth)acrylamide, and N-octylacrylamide. Can be lifted. In addition, the N-alkyl (meth)acrylamide also includes (meth)acrylamide having an amino group such as dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and dimethylaminopropyl (meth)acrylamide. Included. Examples of the N,N-dialkyl (meth)acrylamide include N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, and N,N-dipropyl (meth) Acrylamide, N,N-diisopropyl(meth)acrylamide, N,N-di(n-butyl)(meth)acrylamide, N,N-di(t-butyl)(meth)acrylamide, etc. I can.

Further, the (meth)acrylamides include, for example, various N-hydroxyalkyl (meth)acrylamides. Examples of the N-hydroxyalkyl(meth)acrylamide include N-methylol(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, and N-(2-hydroxypropyl )(Meth)acrylamide, N-(1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(meth)acrylamide Amide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide, N-methyl-N-2-hydroxyethyl(meth)acrylamide, etc. Can be lifted.

Further, the (meth)acrylamides include, for example, various N-alkoxyalkyl (meth)acrylamides. Examples of the N-alkoxyalkyl (meth)acrylamide include N-methoxymethyl (meth)acrylamide and N-butoxymethyl (meth)acrylamide.

In addition, as nitrogen atom-containing monomers other than the N-vinyl cyclic amide and the (meth)acrylamides, for example, aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, and dimethylaminopropyl (meth)acrylate. And amino group-containing monomers such as t-butylaminoethyl (meth)acrylate; Cyano group-containing monomers such as acrylonitrile and methacrylonitrile; (Meth)acryloylmorpholine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyridine, vinylpyrimidine , Vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth)acryloylpyrrolidone, (meth)acryloylpyrrolidine, (meth)acryloylpiperidine, N -A heterocycle-containing monomer such as methylvinylpyrrolidone; Maleimide-based monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide, N-methyl itaconimide, N-ethyl itaconimide, N -Itaconimide systems such as butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-lauryl itaconimide, and N-cyclohexyl itaconimide Monomer, N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(meth)acryloyl-8-oxyoctamethylenesuccinimide Imide group-containing monomers such as succinimide-based monomers such as mid; An isocyanate group-containing monomer, such as 2-(meth)acryloyloxyethyl isocyanate, etc. are mentioned.

1-7. Other copolymerizable monomers

As the copolymerizable monomer in the acrylic polymer (A), in addition to the nitrogen atom-containing monomer and the hydroxyl group-containing monomer, for example, (meth)acrylate alkoxyalkyl ester [for example, 2-methoxyethyl (meth)acrylate, (meth) ) 2-ethoxyethyl acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, (meth)acrylate ) 4-ethoxybutyl acrylic acid, etc.]; Epoxy group-containing monomers [For example, glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, etc.]; A sulfonic acid group-containing monomer [for example, sodium vinylsulfonate]; Phosphoric acid group-containing monomers; (Meth)acrylic acid ester having an alicyclic hydrocarbon group [for example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, etc.]; (Meth)acrylic acid ester having an aromatic hydrocarbon group [for example, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, etc.]; Vinyl esters [for example, vinyl acetate, vinyl propionate, etc.]; Aromatic vinyl compounds [for example, styrene, vinyl toluene, etc.]; Olefins or dienes [for example, ethylene, propylene, butadiene, isoprene, isobutylene, etc.]; Vinyl ethers [for example, vinyl alkyl ethers]; Vinyl chloride and the like.

In addition, polyfunctional monomers may also be mentioned as copolymerizable monomers in the acrylic polymer (A). The polyfunctional monomer acts as a crosslinking component. As the polyfunctional monomer, for example, hexanediol di (meth) acrylate, butanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) acrylate , Neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetra Methylolmethane tri(meth)acrylate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, and the like. In addition, polyfunctional monomers may be used alone or in combination of two or more.

Although the content (ratio) of the polyfunctional monomer in the total monomer units of the acrylic polymer (A) is not particularly limited, 0.5 parts by weight or less (for example, based on the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A)) For example, 0 to 0.5 parts by weight) is preferable, more preferably 0 to 0.35 parts by weight, still more preferably 0 to 0.2 parts by weight. When the content of the polyfunctional monomer is 0.5 parts by weight or less, the pressure-sensitive adhesive layer has an appropriate cohesive strength, and the adhesive strength and the step absorption property are easily improved, which is preferable. In addition, when a crosslinking agent is used, the polyfunctional monomer may not be used, but when the crosslinking agent is not used, the content of the polyfunctional monomer is preferably 0.001 to 0.5 parts by weight, more preferably 0.001 to 0.35 parts by weight, furthermore It is preferably 0.002 to 0.2 parts by weight.

1-8. Acrylic polymer (B)

When the optical pressure-sensitive adhesive layer of the present invention contains an acrylic polymer (A) as a base polymer, the optical pressure-sensitive adhesive layer of the present invention is an acrylic polymer (B) having a weight average molecular weight of 1,000 to 30,000 together with the acrylic polymer (A). It is preferable to contain ). When the acrylic polymer (B) is contained, the adhesiveness to the adherend is improved at the interface of the pressure-sensitive adhesive sheet, so that it becomes easy to obtain strong adhesiveness, and also, it becomes easy to obtain excellent foaming and peeling resistance. In addition, in this specification, "acrylic polymer (B) having a weight average molecular weight of 1,000 to 30,000" is sometimes simply referred to as "acrylic polymer (B)".

The acrylic polymer (B) preferably includes an acrylic polymer composed of a (meth)acrylic acid ester having a cyclic structure in the molecule as an essential monomer component, and a (meth)acrylic acid ester having a cyclic structure in the molecule and a straight or branched chain An acrylic polymer composed of an alkyl (meth)acrylate having an alkyl group as an essential monomer component is more preferably mentioned. That is, the acrylic polymer (B) preferably includes an acrylic polymer containing a (meth)acrylic acid ester having a cyclic structure in the molecule as a monomer unit, and a (meth)acrylic acid ester having a cyclic structure in the molecule as a monomer unit, and An acrylic polymer containing an alkyl (meth)acrylate having a linear or branched alkyl group is more preferably mentioned.

The cyclic structure (ring) of the (meth)acrylic acid ester having a cyclic structure in the molecule (in one molecule) (hereinafter sometimes referred to as ``ring-containing (meth)acrylic acid ester'') is an aromatic ring, non-aromatic It may be any of the rings, and is not particularly limited. Examples of the aromatic ring include an aromatic carbocyclic ring (for example, a monocyclic carbocyclic ring such as a benzene ring or a condensed carbocyclic ring such as a naphthalene ring), and various aromatic heterocyclic rings. Examples of the non-aromatic ring include a non-aromatic aliphatic ring (non-aromatic alicyclic ring) [for example, a cycloalkane ring such as a cyclopentane ring, a cyclohexane ring, a cycloheptane ring, or a cyclooctane ring; Cycloalkene rings, such as a cyclohexene ring, etc.], non-aromatic caustic exchange [for example, a bicyclic hydrocarbon ring in evacuation, pinene, bornane, norbornane, norbornene, etc.; Tricyclic or more aliphatic hydrocarbon rings (crosslinked hydrocarbon rings) and the like in adamantane and the like] and non-aromatic heterocycles (eg, an epoxy ring, an oxolan ring, an oxetane ring, and the like).

Examples of the tricyclic or more aliphatic hydrocarbon ring (3 or more crosslinked hydrocarbon rings) include a dicyclopentanyl group represented by the following formula (3a), a dicyclopentenyl group represented by the following formula (3b), and the following formula An adamantyl group represented by (3c), a tricyclopentanyl group represented by the following formula (3d), a tricyclopentenyl group represented by the following formula (3e), and the like are mentioned.

That is, as the ring-containing (meth)acrylic acid ester, for example, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, etc. Alkyl esters; (Meth)acrylic acid ester having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth)acrylate; Dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl ( (Meth)acrylic acid ester having three or more aliphatic hydrocarbon rings such as meth)acrylate and 2-ethyl-2-adamantyl (meth)acrylate; Aromatic properties such as aryl (meth)acrylates such as phenyl (meth)acrylate, aryloxyalkyl esters of (meth)acrylates such as phenoxyethyl (meth)acrylate, and arylalkyl esters of (meth)acrylates such as benzyl (meth)acrylate (Meth)acrylic acid ester having a ring, etc. are mentioned. Among them, the ring-containing (meth)acrylic acid ester is particularly preferably a non-aromatic ring-containing (meth)acrylic acid ester, more preferably cyclohexyl acrylate (CHA), cyclohexyl methacrylate (CHMA), Dicyclopentanyl acrylate (DCPA), dicyclopentanyl methacrylate (DCPMA), more preferably dicyclopentanyl acrylate (DCPA) and dicyclopentanyl methacrylate (DCPMA). In addition, ring-containing (meth)acrylic acid esters may be used alone or in combination of two or more.

Among the non-aromatic ring-containing (meth)acrylic acid esters, when a (meth)acrylic acid ester having three or more aliphatic hydrocarbon rings (particularly, three or more crosslinked hydrocarbon rings) is used, it is particularly preferable because it is difficult to cause polymerization inhibition. . In addition, (meth)acrylic acid ester having a dicyclopentanyl group represented by the formula (3a) that does not have an unsaturated bond, an adamantyl group represented by the formula (3c), and a tricyclopentanyl group represented by the formula (3d) In the case of using, it is possible to further increase the foaming and releasability, and to remarkably improve the adhesion to a low polarity adherend such as polyethylene or polypropene.

The content (ratio) of the ring-containing (meth)acrylic acid ester in all monomer units of the acrylic polymer (B) (the total amount of the monomer components constituting the acrylic polymer (B)) is not particularly limited, but the acrylic polymer (B) is It is preferably 10 to 90 parts by weight, more preferably 20 to 80 parts by weight, based on the total amount (100 parts by weight) of the monomer component to be constituted. When the content of the ring-containing (meth)acrylic acid ester is 10 parts by weight or more, foaming and peeling resistance is easily improved, which is preferable. In addition, when the content is 90 parts by weight or less, the pressure-sensitive adhesive layer has appropriate flexibility, and the adhesive strength and step absorption property are easily improved, which is preferable.

In addition, as the (meth)acrylate alkyl ester having the linear or branched alkyl group as the monomer unit of the acrylic polymer (B), for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, ( Isopropyl meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, (meth)acrylate ) Hexyl acrylate, (meth) acrylate heptyl, (meth) acrylate octyl, (meth)2-ethylhexyl acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, (meth) Decyl acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexa (meth)acrylate Decyl, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and alkyl (meth)acrylate having 1 to 20 carbon atoms in an alkyl group such as eicosyl (meth)acrylate. . Among them, methyl methacrylate (MMA) is preferred from the viewpoint of improving compatibility with the acrylic polymer (A). Further, the above alkyl (meth)acrylates may be used alone or in combination of two or more.

The content (ratio) of the alkyl (meth)acrylate having a linear or branched alkyl group in the total monomer units of the acrylic polymer (B) (the total amount of the monomer components constituting the acrylic polymer (B)) is not particularly limited. From the viewpoint of foaming releasability, with respect to the total amount (100 parts by weight) of the monomer component constituting the acrylic polymer (B), 10 to 90 parts by weight is preferable, more preferably 20 to 80 parts by weight, even more preferably 20 to 60 parts by weight. It is a part by weight. When the content is 10 parts by weight or more, the adhesive strength to an adherend made of an acrylic resin or polycarbonate tends to be improved, which is preferable.

As the monomer unit of the acrylic polymer (B), in addition to the ring-containing (meth)acrylic acid ester and the (meth)acrylate alkyl ester having a linear or branched alkyl group, a monomer copolymerizable with these monomers (copolymerizable monomer) may be included. . In addition, the content (ratio) of the copolymerizable monomer in all monomer units of the acrylic polymer (B) (the total amount of the monomer components constituting the acrylic polymer (B)) is not particularly limited, but the monomer component constituting the acrylic polymer (B) The total amount (100 parts by weight) is preferably 49.9 parts by weight or less (for example, 0 to 49.9 parts by weight), and more preferably 30 parts by weight or less. Further, the copolymerizable monomer may be used alone or in combination of two or more.

As the copolymerizable monomer (the copolymerizable monomer constituting the acrylic polymer (B)) as the monomer unit of the acrylic polymer (B), for example, (meth)acrylate alkoxyalkyl ester [for example, (meth)acrylic acid 2- Methoxyethyl, (meth)acrylate 2-ethoxyethyl, (meth)acrylate methoxytriethylene glycol, (meth)acrylate 3-methoxypropyl, (meth)acrylate 3-ethoxypropyl, (meth)acrylic acid 4- Methoxybutyl, 4-ethoxybutyl (meth)acrylate, etc.]; Hydroxyl group (hydroxyl)-containing monomers (e.g., 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxy (meth)acrylate) Hydroxyalkyl (meth)acrylates such as hydroxypropyl, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, vinyl alcohol, allyl alcohol, etc.]; An amide group-containing monomer [for example, (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-moiety Oxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, etc.]; Amino group-containing monomers [for example, aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate, and the like]; Cyano group-containing monomers [for example, acrylonitrile, methacrylonitrile, etc.]; A sulfonic acid group-containing monomer [for example, sodium vinylsulfonate]; Phosphoric acid group-containing monomers [eg, 2-hydroxyethylacryloyl phosphate]; An isocyanate group-containing monomer [for example, 2-methacryloyloxyethyl isocyanate, etc.], an imide group-containing monomer [cyclohexyl maleimide, isopropyl maleimide, etc.], etc. are mentioned.

As described above, the acrylic polymer (B) is preferably an acrylic polymer containing, as a monomer unit, a (meth)acrylic acid ester having a cyclic structure in a molecule and an alkyl (meth)acrylate having a linear or branched alkyl group. Especially, it is preferable that it is an acrylic polymer containing a ring-containing (meth)acrylic acid ester and the (meth)acrylate alkyl ester which has the said linear or branched chain alkyl group as a monomer unit. In the acrylic polymer containing a ring-containing (meth)acrylic acid ester and a (meth)acrylic acid alkyl ester having a linear or branched alkyl group as the monomer unit, based on the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (B) The amount of the ring-containing (meth)acrylic acid ester is not particularly limited, but is preferably 10 to 90 parts by weight, and more preferably 20 to 80 parts by weight. In addition, the content of the alkyl (meth)acrylate having a linear or branched alkyl group is not particularly limited, but is preferably 10 to 90 parts by weight, more preferably 20 to 80 parts by weight, still more preferably 20 to 60 parts by weight. to be.

In addition, a particularly preferred specific configuration of the acrylic polymer (B) is as a monomer unit, (1) at least one selected from the group consisting of dicyclopentanyl acrylate, dicyclopentanyl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate. Monomers and (2) acrylic polymers containing methyl methacrylate. In the acrylic polymer (B) having a particularly preferred specific configuration, the content of (1) dicyclopentanyl acrylate, dicyclopentanyl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate in all monomer units of the acrylic polymer (B) ( When two or more types are included, the total amount of them) is 30 to 70 parts by weight based on the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (B), and (2) the content of methyl methacrylate is 30 to 70 It is preferably in parts by weight. However, the acrylic polymer (B) is not limited to the specific configuration.

The acrylic polymer (B) can be obtained by polymerizing the monomer component by a known or common polymerization method. Examples of the polymerization method of the acrylic polymer (B) include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method by irradiation with active energy rays (active energy ray polymerization method). Among them, a bulk polymerization method and a solution polymerization method are preferable, and a solution polymerization method is more preferable.

In the polymerization of the acrylic polymer (B), various general solvents may be used. Examples of the solvent include esters such as ethyl acetate and n-butyl acetate; Aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; Alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; Organic solvents, such as ketones, such as methyl ethyl ketone and methyl isobutyl ketone, are mentioned. In addition, these solvents may be used alone or in combination of two or more.

In addition, in the polymerization of the acrylic polymer (B), a known or commonly used polymerization initiator (eg, a thermal polymerization initiator or a photopolymerization initiator) may be used. Further, the polymerization initiator may be used alone or in combination of two or more.

As a thermal polymerization initiator, for example, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile (AMBN), 2,2'-azobis ( 2-methylpropionic acid)dimethyl, 4,4'-azobis-4-cyanovaleric acid, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'- Azobis (2,4-dimethylvaleronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (2,4,4-trimethylpentane), etc. Co-production initiator; Benzoyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 1,1-bis(t-butylperoxy)-3,3,5- And peroxide initiators such as trimethylcyclohexane and 1,1-bis(t-butylperoxy)cyclododecane. In addition, when performing solution polymerization, it is preferable to use an oil-soluble polymerization initiator. Further, the thermal polymerization initiator may be used alone or in combination of two or more.

The amount of the thermal polymerization initiator to be used is not particularly limited, but is, for example, 0.1 to 15 parts by weight based on 100 parts by weight of the total monomer units of the acrylic polymer (B) (the total amount of the monomer components constituting the acrylic polymer (B)). .

Further, the photopolymerization initiator is not particularly limited, and examples thereof include photopolymerization initiators such as the photopolymerization initiator used in polymerization of the acrylic polymer (A) mentioned above. The amount of the photopolymerization initiator used is not particularly limited and is appropriately selected.

In the polymerization of the acrylic polymer (B), in order to adjust the molecular weight (specifically, to adjust the weight average molecular weight to 1,000 to 30,000), a chain transfer agent may be used. Examples of the chain transfer agent include 2-mercaptoethanol, α-thioglycerol, 2,3-dimercapto-1-propanol, octylmercaptan, t-nonylmercaptan, dodecylmercaptan (laurylmercaptan) , t-dodecylmercaptan, glycidylmercaptan, thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate , Octyl thioglycolate, Isooctyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, thioglycolic acid ester of ethylene glycol, thioglycolic acid ester of neopentyl glycol, thioglycolic acid ester of pentaerythritol, α-methyl And styrene dimers. Among them, from the viewpoint of suppressing whitening of the pressure-sensitive adhesive sheet due to humidification, α-thioglycerol and methyl thioglycolate are preferable, and α-thioglycerol is particularly preferable. In addition, chain transfer agents may be used alone or in combination of two or more.

The content (usage) of the chain transfer agent is not particularly limited, but is preferably 0.1 to 20 parts by weight based on 100 parts by weight of the total monomer units of the acrylic polymer (B) (the total amount of the monomer components constituting the acrylic polymer (B)), It is more preferably 0.2 to 15 parts by weight, still more preferably 0.3 to 10 parts by weight. By setting the content (usage) of the chain transfer agent in the above range, an acrylic polymer having a weight average molecular weight of 1,000 to 30,000 can be easily obtained.

The weight average molecular weight (Mw) of the acrylic polymer (B) is 1,000 to 30,000, preferably 1,000 to 20,000, more preferably 1,500 to 10,000, and even more preferably 2,000 to 8,000. Since the weight average molecular weight of the acrylic polymer (B) is 1,000 or more, adhesive strength and retention properties are improved, and foaming and peeling resistance is improved. On the other hand, since the weight average molecular weight of the acrylic polymer (B) is 30,000 or less, it is easy to increase the adhesive force, and the foaming and peeling resistance is improved.

The weight average molecular weight (Mw) of the acrylic polymer (B) can be calculated in terms of polystyrene by the GPC method. For example, it can measure under the following conditions using the high-speed GPC apparatus "HPLC-8120GPC" manufactured by Tosoh Corporation.

Column: TSKgel SuperHZM-H/HZ4000/HZ3000/HZ2000

Solvent: tetrahydrofuran

Flow rate: 0.6 ml/min

The glass transition temperature (Tg) of the acrylic polymer (B) is not particularly limited, but is preferably 20 to 300°C, more preferably 30 to 300°C, and still more preferably 40 to 300°C. When the glass transition temperature of the acrylic polymer (B) is 20° C. or higher, the foaming and peeling resistance is easily improved, which is preferable. Further, when the glass transition temperature of the acrylic polymer (B) is 300° C. or less, the pressure-sensitive adhesive layer has appropriate flexibility, good adhesive strength and good step absorption properties are easily obtained, and excellent adhesion reliability is easily obtained, which is preferable.

The glass transition temperature (Tg) of the acrylic polymer (B) is a glass transition temperature (theoretical value) represented by the following formula.

1/Tg =W ₁ /Tg ₁ +W ₂ /Tg ₂ +... +W _n /Tg _n

In the above formula, Tg is the glass transition temperature (unit: K) of the acrylic polymer (B), Tg _i is the glass transition temperature (unit: K) when the monomer i forms a homopolymer, and W _i is the monomer of the monomer i The weight fraction in the total amount of the components is shown (i = 1, 2, ... n).

As the Tg of the homopolymer of the monomer constituting the acrylic polymer (B), the values shown in Table 1 can be adopted. In addition, as Tg of the homopolymer of a monomer not described in Table 1, the numerical values described in the "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc, 1989) can be adopted. In addition, as the Tg of the homopolymer of a monomer not described in the above document, a value obtained by the above-described measurement method (peak top temperature of tan δ by viscoelasticity test) can be adopted.

In addition, the copolymer of "DCPMA/MMA=60/40" in Table 1 means a copolymer of 60 parts by weight of DCPMA and 40 parts by weight of MMA.

In the case where the optical pressure-sensitive adhesive layer of the present invention contains acrylic polymers (A) and (B), the content of the acrylic polymer (B) is not particularly limited, but 1 to 30 parts by weight based on 100 parts by weight of the acrylic polymer (A). Part by weight is preferred, more preferably 2 to 20 parts by weight, and still more preferably 2 to 10 parts by weight. That is, the content of the acrylic polymer (B) in the optical pressure-sensitive adhesive layer of the present invention is not particularly limited, but is preferably 1 to 30 parts by weight based on 100 parts by weight of all monomer units of the acrylic polymer (A). It is preferably 2 to 20 parts by weight, more preferably 2 to 10 parts by weight. Although the content of the acrylic polymer (B) in the pressure-sensitive adhesive composition is not particularly limited, for example, with respect to 100 parts by weight of the monomer mixture, 1 to 30 parts by weight is preferable, more preferably 2 to 20 parts by weight, further It is preferably 2 to 10 parts by weight. When the content of the acrylic polymer (B) is 1 part by weight or more, excellent adhesiveness and excellent foaming and peeling resistance are easily obtained, which is preferable. In addition, when the content of the acrylic polymer (B) is 30 parts by weight or less, excellent transparency and adhesion reliability are easily obtained, which is preferable.

It does not specifically limit as a manufacturing method of the said adhesive layer containing acrylic polymers (A) and (B). For example, it is produced through a process of adding and mixing a benzotriazole-based compound, an acrylic polymer (B), and an additive as necessary to a monomer mixture or a partial polymer thereof forming an acrylic polymer (A).

1-9. additive

In the optical pressure-sensitive adhesive layer of the present invention, if necessary, a crosslinking agent, a crosslinking accelerator, a silane coupling agent, a tackifier resin (rosin derivative, polyterpene resin, petroleum resin, oil-soluble phenol, etc.), an anti-aging agent, a filler, a colorant (pigment or dye) Etc.), ultraviolet absorbers, antioxidants, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, and other known additives may be included within a range that does not impair the properties of the present invention. In addition, these additives may be used alone or in combination of two or more.

When a crosslinking agent is included in the pressure-sensitive adhesive layer, the base polymer is crosslinked to increase the gel fraction, and it becomes easy to improve foaming and peeling resistance. For example, since the control of the gel fraction can be easily increased by crosslinking an acrylic polymer (especially, an acrylic polymer (A)), it becomes easy to improve the foaming and peeling resistance. Examples of the crosslinking agent include isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxa And a sleepy crosslinking agent, an aziridine crosslinking agent, and an amine crosslinking agent. Among them, when the optical pressure-sensitive adhesive layer of the present invention is a pressure-sensitive adhesive layer containing an acrylic polymer (A) as a base polymer, an isocyanate-based crosslinking agent and an epoxy-based crosslinking agent are preferable, and more preferably, isocyanate It is a system crosslinking agent. Further, the crosslinking agent may be used alone or in combination of two or more.

Examples of the isocyanate crosslinking agent (polyfunctional isocyanate compound) include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; Alicyclic polyisocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylene diisocyanate; Aromatic polyisocyanates, such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylene diisocyanate, etc. are mentioned. In addition, as the isocyanate-based crosslinking agent, for example, trimethylolpropane/tolylenediisocyanate adduct [Nippon Polyurethane Co., Ltd. product, brand name "Colonate L"], trimethylolpropane/hexamethylenediisocyanate adduct [ Commercially available products such as Nippon Polyurethane Co., Ltd. product, brand name "Colonate HL"], trimethylolpropane/xylene diisocyanate adduct [Mitsui Chemical Co., Ltd. product, brand name "Takenate D-110N"] are also listed. have.

Examples of the epoxy-based crosslinking agent (polyfunctional epoxy compound) include N,N,N′,N′-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N -Diglycidylaminomethyl)cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol Diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglyci Dyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxyethyl) isocyanurate, resorcin digly In addition to cidyl ether and bisphenol-S-diglycidyl ether, epoxy resins having two or more epoxy groups in the molecule may be mentioned. Moreover, as said epoxy-type crosslinking agent, commercial items, such as the product made by Mitsubishi Gas Chemical Co., Ltd. and a brand name "Tetrad C", are also mentioned, for example.

Although the content of the crosslinking agent in the optical pressure-sensitive adhesive layer is not particularly limited, for example, when the optical pressure-sensitive adhesive layer of the present invention is a pressure-sensitive adhesive layer containing an acrylic polymer (A) as a base polymer, 100 parts by weight of an acrylic polymer (A) With respect to, it is preferably 0.001 to 10 parts by weight, more preferably 0.01 to 5 parts by weight. When the content of the crosslinking agent is 0.001 part by weight or more, the foaming and peeling resistance is easily improved, which is preferable. On the other hand, when the content of the crosslinking agent is 10 parts by weight or less, since the pressure-sensitive adhesive layer has appropriate flexibility and the adhesive strength is easily improved, it is preferable.

When a silane coupling agent is contained in the said optical pressure-sensitive adhesive layer, excellent adhesion to glass (particularly, excellent adhesion reliability to glass at high temperature and high humidity) is easily obtained, which is preferable. The silane coupling agent is not particularly limited, but γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-aminopropyltrime And oxysilane. Among them, γ-glycidoxypropyltrimethoxysilane is preferable. Moreover, as the said silane coupling agent, a commercial item, such as a brand name "KBM-403" (made by Shin-Etsu Chemical Co., Ltd.), is also mentioned, for example. Further, the silane coupling agent may be used alone or in combination of two or more.

Although the content of the silane coupling agent in the optical pressure-sensitive adhesive layer is not particularly limited, for example, when the optical pressure-sensitive adhesive layer of the present invention is a pressure-sensitive adhesive layer containing an acrylic polymer (A) as a base polymer, adhesion to glass From the viewpoint of improving reliability, 0.01 to 1 part by weight is preferred, more preferably 0.03 to 0.5 part by weight based on 100 parts by weight of the acrylic polymer (A).

2. Adhesive sheet

The pressure-sensitive adhesive sheet of the present invention may have the aforementioned optical pressure-sensitive adhesive layer (the optical pressure-sensitive adhesive layer of the present invention), and is not particularly limited in other respects.

The pressure-sensitive adhesive sheet of the present invention may be a double-sided pressure-sensitive adhesive sheet in which both sides become the pressure-sensitive adhesive layer surface, or may be a one-sided pressure-sensitive adhesive sheet in which only one side becomes the pressure-sensitive adhesive layer surface. Especially, it is preferable that it is a double-sided adhesive sheet from a viewpoint of bonding two members. In addition, in the present specification, in the case of a "adhesive sheet", a tape-like thing, that is, a "adhesive tape" is also included. In addition, in this specification, the surface of an adhesive layer may be called "adhesive surface."

The pressure-sensitive adhesive sheet of the present invention may be provided with a separator (release liner) on the pressure-sensitive adhesive surface until use.

The adhesive sheet of the present invention may be a so-called ``inorganic type'' adhesive sheet (hereinafter sometimes referred to as ``inorganic material adhesive sheet'') without a substrate (substrate layer), or a type of adhesive sheet having a substrate (Hereinafter, it may be referred to as "the adhesive sheet provided with a base material"). As the inorganic adhesive sheet, for example, a double-sided adhesive sheet including only the adhesive layer, or a double-sided adhesive including the adhesive layer and an adhesive layer other than the adhesive layer (sometimes referred to as ``other adhesive layer'') Sheets, etc. are mentioned. On the other hand, as an adhesive sheet provided with a base material, the adhesive sheet etc. which have the said adhesive layer on at least one side of the base material are mentioned. Among them, an inorganic material adhesive sheet (inorganic material double-sided pressure-sensitive adhesive sheet) is preferable, and more preferably, it is an inorganic material double-sided pressure-sensitive adhesive sheet containing only the pressure-sensitive adhesive layer. In addition, the said "substrate (substrate layer)" does not include a separator that peels off when the pressure-sensitive adhesive sheet is used (attached).

It is preferable that the adhesive sheet of this invention is an inorganic material adhesive sheet. If it is an adhesive sheet provided with a base material using a moisture-proof base material, it can be said that a corrosion-preventing function can be provided to some extent, so that the inorganic material adhesive sheet has a higher significance that a corrosion-preventing function can be imparted.

2-1. Various properties of adhesive sheet

The adhesive force of the adhesive sheet of the present invention to the glass plate by 180° (especially, the adhesive force of the adhesive surface provided by the adhesive layer (the optical adhesive layer of the present invention) to the glass plate by 180°) is not particularly limited, but the adhesive force If this is high, it is preferably 8N/20mm or more, more preferably 10N/20mm or more, still more preferably 12N/20mm or more, and more preferably from the viewpoint of obtaining sufficient adhesion to the metal surface and improving the corrosion prevention effect. It is more than 14N/20mm. When the 180° peeling adhesive force of the pressure-sensitive adhesive sheet of the present invention to the glass plate is more than a certain value, the adhesiveness to the glass and the suppression of lifting at a step are even more excellent. In addition, the upper limit of the 180° peeling adhesive force of the pressure-sensitive adhesive sheet of the present invention to the glass plate is not particularly limited, but, for example, 40N/20mm is preferable, and more preferably 60N/20mm. The 180° peel adhesion to the glass plate is determined by the following 180° peel adhesion measurement method.

Although it does not specifically limit as said glass plate, For example, a brand name "soda-lime glass #0050" (made by Matsunami Glass Co., Ltd.) is mentioned. Moreover, alkali-free glass, chemically strengthened glass, etc. are also mentioned.

The 180° peel adhesion of the adhesive sheet of the present invention to the acrylic plate (in particular, 180° peel adhesion of the adhesive surface provided by the pressure-sensitive adhesive layer (the optical pressure-sensitive adhesive layer of the present invention) to the acrylic plate) is not particularly limited. If the adhesive force is high, from the viewpoint of obtaining sufficient adhesion to the metal surface and improving the corrosion prevention effect, it is preferably 10N/20mm or more, more preferably 12N/20mm or more, and still more preferably 14N/20mm or more. When the adhesive sheet of the present invention has a 180° peel adhesion to an acrylic plate of 10 N/20 mm or more, good adhesion to the acrylic plate and good anti-lifting property at a good step are easily obtained, and thus, it is preferable. In addition, the upper limit of the 180° peeling adhesion force of the pressure-sensitive adhesive sheet of the present invention to the acrylic plate is not particularly limited, but is, for example, 40N/20mm, more preferably 60N/20mm. The 180° peel adhesion to the acrylic plate is determined from the following 180° peel adhesion measurement method.

Although it does not specifically limit as said acrylic board, For example, a PMMA board (brand name "Acrylic", Mitsubishi Rayon Co., Ltd. make) etc. are mentioned.

A. Method of measuring 180° peel adhesion

The adhesive surface of the pressure-sensitive adhesive sheet was bonded to the adherend, pressed under conditions of 2 kg roller, one round trip, and aged for 30 minutes in an atmosphere of 23°C and 50% RH. After aging, in accordance with JIS Z 0237, in an atmosphere of 23°C and 50% RH, the adhesive sheet was removed from the adherend under conditions of a tensile speed of 300 mm/min and a peel angle of 180°, and 180° peel adhesion (N/20 mm ) Is measured.

B. Thickness

The thickness (total thickness) of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but is preferably 12 to 350 µm, and more preferably 12 to 300 µm. If the thickness is more than a certain amount, it is difficult to cause peeling at the stepped portion, which is preferable. In addition, when the thickness is less than a certain amount, it is easy to maintain an excellent appearance during manufacture, which is preferable. In addition, it is assumed that the thickness of the separator is not included in the thickness of the pressure-sensitive adhesive sheet of the present invention.

C. Hayes

Although the haze (according to JIS K7136) of the adhesive sheet of the present invention is not particularly limited, it is preferably 1.0% or less, and more preferably 0.8% or less. When the haze is 1.0% or less, excellent transparency and excellent appearance are obtained, which is preferable. In addition, the haze is, for example, after leaving the pressure-sensitive adhesive sheet in a steady state (23° C., 50% RH) for at least 24 hours, and then peeling it off when a separator is provided, and slide glass (eg, 91.8% total light transmittance). , Haze 0.4%) as a sample, and a haze meter (manufactured by Murakami Shikisai Kijutsu Kenkyusho Co., Ltd., brand name "HM-150") can be used for measurement.

D. Total light transmittance

Although the total light transmittance (according to JIS K7361-1) in the visible light wavelength range of the adhesive sheet of the present invention is not particularly limited, it is preferably 85% or more, and more preferably 88% or more. When the total light transmittance is 85% or more, excellent transparency and excellent appearance are obtained, which is preferable. In addition, the total light transmittance is, for example, after leaving the pressure-sensitive adhesive sheet in a steady state (23° C., 50% RH) for at least 24 hours, and then peeling it off when a separator is provided, and slide glass (eg, 91.8 total light transmittance). %, haze 0.4%) as a sample, it can be measured using a haze meter (manufactured by Murakami Shikisai Kijutsu Kenkyusho Co., Ltd., brand name "HM-150").

2-2. Manufacturing method of adhesive sheet

The pressure-sensitive adhesive sheet of the present invention is not particularly limited, but it is preferably manufactured according to a known or commonly used manufacturing method. For example, when the adhesive sheet of the present invention is an inorganic adhesive sheet, it is obtained by forming the adhesive layer (the optical adhesive layer of the present invention) on a separator by the method described above. In addition, when the pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet provided with a substrate, it may be obtained by directly forming the pressure-sensitive adhesive layer on the surface of the substrate (direct yarn method), and once the pressure-sensitive adhesive layer is formed on the separator, the substrate It can also be obtained by forming the pressure-sensitive adhesive layer on a substrate by transferring (bonding) to (transfer method).

2-3. Adhesive layer of adhesive sheet

The gel fraction (the ratio of the solvent-insoluble component) of the pressure-sensitive adhesive layer (the optical pressure-sensitive adhesive layer of the present invention) of the pressure-sensitive adhesive sheet of the present invention is not particularly limited, but is preferably 65 to 99%, more preferably 68 to 95% , More preferably 70 to 95%. When the gel fraction is 65% or more, the cohesive strength of the pressure-sensitive adhesive layer is improved, foaming or peeling is suppressed at the interface with the adherend in a high-temperature environment, and excellent foaming and peeling resistance is easily obtained, which is preferable. In addition, when the gel fraction is 99% or less, appropriate flexibility is obtained, and adhesion is further improved, which is preferable.

(Gel fraction)

The said gel fraction (ratio of a solvent-insoluble component) is a value calculated by the following "Measurement method of a gel fraction" specifically, for example.

About 0.1 g of the pressure-sensitive adhesive layer was taken from the pressure-sensitive adhesive sheet, wrapped in a porous tetrafluoroethylene sheet (trade name "NTF1122", manufactured by Nitto Denko Co., Ltd.) with an average pore diameter of 0.2 μm, then tied with twisted yarn, and the weight at that time was measured. Thus, this weight is called the weight before immersion. In addition, the weight before immersion is the total weight of the pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer collected above), the tetrafluoroethylene sheet, and the yarn. In addition, the total weight of the tetrafluoroethylene sheet and the flue yarn is also measured, and the weight is referred to as the bag weight.

Next, the pressure-sensitive adhesive layer was wrapped with a tetrafluoroethylene sheet and tied with a strand (referred to as "sample") into a 50 ml container filled with ethyl acetate, and allowed to stand at 23°C for 7 days. Thereafter, a sample (after ethyl acetate treatment) was taken out from the container, transferred to an aluminum cup, dried in a dryer at 130° C. for 2 hours to remove ethyl acetate, and the weight was measured, and the weight after immersion It is called this.

And the gel fraction is calculated from the following formula.

Gel fraction [% (weight%)] = (X-Y)/(Z-Y)×100

In addition, the gel fraction can be controlled by, for example, the monomer composition of the base polymer (eg, acrylic polymer (A), etc.), the weight average molecular weight, the amount of crosslinking agent used (added amount), and the like.

(300% tensile residual stress)

300% tensile residual stress of the pressure-sensitive adhesive layer (the optical pressure-sensitive adhesive layer of the present invention) is not particularly limited, and 7 to 25N / cm ² is preferable, and more preferably from 7 to 20N / cm ^2, more preferably 7 to 16 N/cm ² , and more preferably 7 to 14 N/cm ² . When the said (300)% tensile residual stress is 7 N/cm ² or more, it is easy to obtain favorable foaming and peeling resistance, and is preferable. Moreover, when the said 300% tensile residual stress is 25 N/cm ² or less, favorable stress relaxation property is obtained, and it is easy to obtain good level difference followability, and it is preferable.

When the pressure-sensitive adhesive sheet of the present invention has the pressure-sensitive adhesive layer having a tensile residual stress of 300% within a specific range, excellent stress relaxation properties are easily obtained, and excellent level difference followability is easily exhibited. For example, a large step difference (for example, a step having a height of about 45 µm, particularly a step having a height of 20 to 50 µm) can be well followed.

The 300% tensile residual stress is obtained by stretching the pressure-sensitive adhesive layer to 300% of elongation (distortion) in the longitudinal direction under an environment of 23°C, maintaining the elongation, and obtaining a tensile load applied to the pressure-sensitive adhesive layer after 300 seconds elapse from the end of tensile ^{, The tensile load is a limit value (N/cm 2} ) in the initial cross-sectional area (cross-sectional area before tensioning) of the pressure-sensitive adhesive layer. In addition, the initial elongation of the pressure-sensitive adhesive layer is 100%.

(thickness)

The thickness of the pressure-sensitive adhesive layer (especially the optical pressure-sensitive adhesive layer of the present invention) is not particularly limited, but is preferably 12 to 350 µm, more preferably 12 to 300 µm. When the thickness is more than a certain level, step followability and adhesion reliability are improved, which is preferable. Moreover, when the thickness is not more than a certain level, handling properties and manufacturability are particularly excellent and are preferable.

(Manufacturing method)

The method for producing the pressure-sensitive adhesive layer (the optical pressure-sensitive adhesive layer of the present invention) is not particularly limited, but for example, the pressure-sensitive adhesive composition is applied (coated) on a substrate or a release liner, and dried, cured, or And drying and curing.

In addition, a known coating method may be used for the application (coating) of the pressure-sensitive adhesive composition. For example, a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, a spray coater, a comma coater, a direct coater, or the like may be used.

2-4. Different layers of adhesive sheet

The pressure-sensitive adhesive sheet of the present invention may have other layers in addition to the pressure-sensitive adhesive layer (the optical pressure-sensitive adhesive layer of the present invention). Other layers include, for example, other pressure-sensitive adhesive layers (adhesive layers other than the pressure-sensitive adhesive layers), intermediate layers, and undercoat layers. Further, the pressure-sensitive adhesive sheet of the present invention may have two or more other layers.

2-5. Base material of adhesive sheet

In the case where the pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet with a substrate, the substrate is not particularly limited, and examples thereof include various optical films such as plastic films, antireflection (AR) films, polarizing plates, and retardation plates. . Materials such as the plastic film include, for example, polyester resins such as polyethylene terephthalate (PET), acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate, triacetyl cellulose (TAC), Polysulfone, polyarylate, polyimide, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, ethylene-propylene copolymer, brand name ``ARTON (cyclic olefin polymer, manufactured by JSR Corporation)'', And plastic materials such as cyclic olefin-based polymers such as the brand name “ZEONOR (cyclic olefin-based polymer, manufactured by Nippon Xeon Co., Ltd.)”. In addition, these plastic materials may be used alone or in combination of two or more. In addition, when the said "substrate" is affixed to an adherend, when attaching an adhesive sheet to an adherend, it is a part attached to an adherend together with an adhesive layer. The separator (release liner) to be peeled off when the pressure-sensitive adhesive sheet is used (at the time of attaching) is not included in the "substrate".

It is preferable that the substrate is transparent. The total light transmittance (according to JIS K7361-1) in the visible light wavelength range of the substrate is not particularly limited, but is preferably 85% or more, and more preferably 88% or more. In addition, the haze (according to JIS K7136) of the substrate is not particularly limited, but is preferably 1.0% or less, and more preferably 0.8% or less. Examples of such a transparent substrate include a PET film, a brand name "Arton", and a brand name "Zeonoa" and other non-oriented films.

The thickness of the substrate is not particularly limited, but is preferably 12 to 500 µm, for example. In addition, the substrate may have any form of a single layer or a multilayer. Further, the surface of the substrate may be appropriately subjected to known and conventional surface treatment such as physical treatment such as corona discharge treatment and plasma treatment, and chemical treatment such as primer treatment.

2-6. Separator of adhesive sheet

The pressure-sensitive adhesive sheet of the present invention may be provided with a separator (release liner) on the pressure-sensitive adhesive surface until use. In addition, when the pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, each of the pressure-sensitive adhesive faces may be protected by two separators, or protected in a form wound in a roll shape by one separator with both sides being peeling faces. It could be. The separator is used as a protective material for the pressure-sensitive adhesive layer and is peeled off when adhered to an adherend. In addition, when the pressure-sensitive adhesive sheet of the present invention is an inorganic material pressure-sensitive adhesive sheet, the separator also serves as a support for the pressure-sensitive adhesive layer. In addition, the separator does not necessarily have to be installed.

As the separator, a common release paper or the like can be used, and it is not particularly limited. For example, a substrate having a peeling treatment layer, a low-adhesive substrate containing a fluoropolymer, and a low-adhesive substrate containing a non-polar polymer may be mentioned. Examples of the substrate having the release treatment layer include a plastic film or paper surface-treated with a release treatment agent such as silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide. As a fluorine-based polymer in the low-adhesion substrate containing the fluorine polymer, for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoro A propylene copolymer, a chlorofluoroethylene-vinylidene fluoride copolymer, etc. are mentioned. In addition, examples of the non-polar polymer include olefin-based resins (eg, polyethylene, polypropylene, etc.), and polyester-based substrates (polyethylene terephthalate-based substrates, polyethylene naphthalate-based substrates, and polybutyl). Renterephthalate-based substrates, etc.) are also used. In addition, the separator can be formed by a known or commonly used method. In addition, the thickness of the separator and the like are not particularly limited.

2-7. Use of adhesive sheet, etc.

Since the pressure-sensitive adhesive sheet of the present invention has the aforementioned pressure-sensitive adhesive layer (the optical pressure-sensitive adhesive layer of the present invention), it is excellent in adhesiveness and foaming and peeling resistance. Moreover, it is excellent in stress relaxation property and is excellent in step followability. For this reason, adhesion reliability, particularly, adhesion reliability at high temperatures is excellent. In addition, it is excellent in the suppression of occurrence of bending under a high temperature environment.

For this reason, the pressure-sensitive adhesive sheet of the present invention is usefully used for an adherend where foaming is likely to occur at the interface at high temperatures. For example, polymethyl methacrylate resin (PMMA) may contain an unreacted monomer, and foaming due to foreign substances is likely to occur at high temperatures. In addition, polycarbonate (PC) tends to generate outgass of water and carbon dioxide at high temperatures. Since the pressure-sensitive adhesive sheet of the present invention is excellent in foaming and peeling resistance, it is also usefully used for a plastic adherend containing such a resin.

Further, the pressure-sensitive adhesive sheet of the present invention is usefully used not only for an adherend having a small coefficient of linear expansion, but also for an adherend having a large coefficient of linear expansion. In addition, the adherend having a small coefficient of linear expansion is not particularly limited, but, for example, a glass plate (coefficient of linear expansion: 0.3×10 ^-5 to 0.8×10 ^-5 /°C), a polyethylene terephthalate substrate (PET film, coefficient of linear expansion: 1.5×10 ^-5 to 2×10 ^-5 /°C) and the like. In addition, the adherend having a large coefficient of linear expansion is not particularly limited, but examples thereof include a resin substrate having a large coefficient of linear expansion, and more specifically, a polycarbonate resin substrate (PC, coefficient of linear expansion: 7×10 ^{− 5} to 8×10 ^-5 /°C), polymethyl methacrylate resin substrate (PMMA, coefficient of linear expansion: 7×10 ^-5 to 8×10 ^-5 /°C), cycloolefin polymer substrate (COP, coefficient of linear expansion: 6 ×10 ^-5 to 7 ×10 ^-5 /°C), the brand name “Zeonoa” (manufactured by Nippon Xeon Corporation), and the brand name “Arton” (manufactured by JSR Corporation), and the like.

The pressure-sensitive adhesive sheet of the present invention is usefully used for bonding between an adherend having a small coefficient of linear expansion and an adherend having a large coefficient of linear expansion. Specifically, the pressure-sensitive adhesive sheet of the present invention is preferably used for bonding a glass adherend (eg, a glass plate, a chemically strengthened glass, a glass lens, etc.) to a resin substrate having a large coefficient of linear expansion.

As described above, the pressure-sensitive adhesive sheet of the present invention is useful for bonding adherends of various materials, and is particularly useful for bonding glass adherends and plastic adherends. Further, the plastic adherend may be an optical film such as a plastic film having an ITO (oxide of indium and tin) layer on the surface.

Further, the pressure-sensitive adhesive sheet of the present invention is usefully used not only for an adherend having a smooth surface, but also for an adherend having a stepped surface. In particular, the pressure-sensitive adhesive sheet of the present invention is usefully used for bonding a glass adherend and a resin substrate having a large linear expansion coefficient, even if at least one of the glass adherend and the resin substrate having a large linear expansion coefficient has a step on the surface.

For example, the adhesive sheet of the present invention is a laminate composed of a PET film (polyethylene terephthalate support), an ITO layer, and a copper wiring, the ITO layer is patterned, and the metal wiring is connected to the pattern of the ITO. When a laminate having a structure is fixed to an adherend, it can be preferably used. The laminate is made of a material having a different modulus of elasticity or linear expansion, and may be bent in a high-temperature environment, but the pressure-sensitive adhesive sheet of the present invention can effectively suppress the occurrence of bending in a high-temperature environment.

The pressure-sensitive adhesive sheet of the present invention is suitably used for manufacturing applications of portable electronic devices. This is because the pressure-sensitive adhesive sheet of the present invention can suppress the occurrence of bending in a high-temperature environment, and thus a portable electronic device having a good appearance in the display portion can be easily manufactured. Examples of the portable electronic devices include mobile phones, PHS, smart phones, tablets (tablet-type computers), mobile computers (mobile PCs), portable information terminals (PDAs), electronic notebooks, portable televisions, portable radios, etc. A broadcast receiver, a portable game machine, a portable audio player, a portable DVD player, a camera such as a digital camera, and a camcorder type video camera.

The pressure-sensitive adhesive sheet of the present invention is preferably used, for example, for attaching members or modules constituting a portable electronic device to each other, or fixing members or modules constituting a portable electronic device to a housing. More specifically, bonding of a cover glass or lens (especially a glass lens) to a touch panel or a touch sensor, fixing a cover glass or lens (especially a glass lens) to the housing, fixing a display panel to the housing, a sheet-like keyboard or a touch panel Such as fixing to the housing of the input device, bonding of the protection panel of the information display unit to the housing, bonding of the housings, bonding of the housing and decorative sheets, fixing or bonding of various members or modules constituting portable electronic devices, etc. have. In addition, in this specification, the display panel refers to a structure constituted at least by a lens (especially a glass lens) and a touch panel. In addition, the lens in the present specification is a concept including both a transparent body exhibiting a refractive action of light and a transparent body having no refractive action of light. That is, the lens in the present specification also includes a simple window panel without a refractive action.

In addition, the pressure-sensitive adhesive sheet of the present invention is preferably used for optical applications. That is, it is preferable that the adhesive sheet of this invention is an optical adhesive sheet used for an optical application. More specifically, it is preferably used, for example, for bonding optical members (for bonding optical members) or for manufacturing products (optical products) in which the optical members are used.

3. Optical member

The optical member of the present invention is an optical member having at least the pressure-sensitive adhesive sheet and a substrate, the substrate is provided with a metal wiring (for example, copper wiring, etc.) on at least one side, and the side of the substrate having the metal wiring The pressure-sensitive adhesive layer (the optical pressure-sensitive adhesive layer of the present invention) may be adhered on the surface, and it is not particularly limited in other respects. Further, the pressure-sensitive adhesive sheet may have a separator provided on the pressure-sensitive adhesive surface until use, but since the pressure-sensitive adhesive sheet in the optical member of the present invention is a pressure-sensitive adhesive sheet at the time of use, it does not have a separator.

In addition, from the viewpoint of obtaining an excellent anti-corrosion effect, it is preferable that the optical member has the pressure-sensitive adhesive layer on the side opposite to the side having the metal wiring of the substrate, and the side having the metal wiring of the substrate is It is more preferable that the pressure-sensitive adhesive layer is adhered on the opposite side.

The material constituting the metal wiring is not particularly limited, but for example, titanium, silicon, niobium, indium, zinc, tin, gold, silver, copper, aluminum, cobalt, chromium, nickel, lead, iron, palladium, Metals, such as platinum, tungsten, zirconium, tantalum, and hafnium, are mentioned. Further, those containing two or more of these metals, and alloys containing these metals as a main component may also be mentioned. Among them, gold, silver, and copper are preferable from the viewpoint of conductivity, and copper is more preferable from the viewpoint of conductivity and cost. That is, it is particularly preferable that the metal wiring is a copper wiring. In addition, the same applies to the material constituting the metal wiring of the touch panel to be described later.

An optical member refers to a member having optical properties (eg, polarization, light refraction, light scattering, light reflectivity, light transmission, light absorption, light diffraction, optical rotation, visibility, etc.). Although it does not specifically limit as a board|substrate which comprises the said optical member, For example, a board|substrate which comprises devices (optical devices), such as a display device (image display device) and an input device, or a board used for these devices, may be mentioned. , For example, a polarizing plate, a wavelength plate, a retardation plate, an optical compensation film, a brightness enhancing film, a light guide plate, a reflective film, an antireflection film, a hard coating film (a film treated with a hard coating on at least one side of a plastic film such as a PET film ), transparent conductive film (e.g., a plastic film having an ITO layer on the surface (preferably, an ITO film such as PET-ITO, polycarbonate, or cycloolefin polymer)), design film, decorative film, surface Protective plates, prisms, lenses, color filters, transparent substrates (glass sensors, glass display panels (LCD, etc.), glass substrates such as glass plates with transparent electrodes, etc.), or substrates on which these are laminated (collectively, ``functional films'') It may be referred to as this) and the like. In addition, these films may have a metal nanowire layer, a conductive polymer layer, or the like. In addition, fine metal wires may be mesh-printed on these films. In addition, the said "plate" and "film" shall each include a form, such as a plate shape, a film shape, a sheet shape, and, for example, a "polarization film" shall include a "polarization plate" and a "polarization sheet", etc. do. In addition, the "film" shall include a film sensor or the like.

Examples of the display device include a liquid crystal display device, an organic EL (electroluminescence) display device, a plasma display panel (PDP), and electronic paper. In addition, the input device may be a touch panel or the like.

The substrate constituting the optical member is not particularly limited, but, for example, a substrate including glass, acrylic resin, polycarbonate, polyethylene terephthalate, cycloolefin polymer, metal thin film, etc. A film-like, plate-like substrate, etc.), etc. are mentioned. In addition, the ``optical member'' in the present invention also includes a member (design film, decorative film, surface protection film, etc.) that plays a decorative or protective role while maintaining visibility of a display device or an input device as described above. It should be.

If the pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet with a substrate, and the pressure-sensitive adhesive sheet constitutes a member having optical properties, the substrate can be identified as the substrate, and the pressure-sensitive adhesive sheet is referred to as the optical member of the present invention. I can.

When the adhesive sheet of the present invention is an adhesive sheet provided with a substrate and the functional film is used as the substrate, the adhesive sheet of the present invention is a "adhesive functional film" having the adhesive layer on at least one side of the functional film. It can also be used as.

Next, with reference to the schematic diagram of FIG. 1, a specific example concerning a particularly preferable form of the optical member of the present invention will be described.

In (A) of FIG. 1, it is an optical member which has at least the board|substrate which is the adhesive sheet 10 and the transparent conductive film 11, The transparent conductive film 11 is provided with the metal wiring 3 on one side, and the adhesive sheet The optical member 1 in which (10) is bonded on the side of the transparent conductive film 11 on the side with the metal wiring 3 is described.

In (B) of FIG. 1, it is an optical member which has at least a board|substrate which is the adhesive sheet 10 and the transparent board|substrate 12, The transparent board|substrate 12 is provided with the metal wiring 3 on one side, and the adhesive sheet 10 The optical member 1 in which) is bonded on the side of the transparent substrate 12 on the side with the metal wiring 3 is described.

In (C) of FIG. 1, it is an optical member which has at least the board|substrate which is the adhesive sheet 10 and the film sensor 13, The film sensor 13 is provided with the metal wiring 3 on one surface, and the adhesive sheet 10 The optical member 1 in which) is bonded on the side of the film sensor 13 on the side with the metal wiring 3 is described.

4. Touch panel

The touch panel of the present invention is a touch panel having at least the pressure-sensitive adhesive sheet and a substrate, the substrate having a metal wiring (for example, copper wiring, etc.) on one side, and the side of the substrate having the metal wiring The pressure-sensitive adhesive layer may be adhered on, and it is not particularly limited in other respects. Moreover, since the said adhesive sheet in the touch panel of this invention is an adhesive sheet at the time of use, it does not have a separator.

As the touch panel, the optical member of the present invention is formed by bonding the optical member of the present invention with another optical member (which may or may not necessarily have the pressure-sensitive adhesive sheet, but it is preferable from the viewpoint of obtaining a more excellent anti-corrosion effect). Embodiments are preferred. In addition, the separate optical members may be singular or plural.

Although it does not specifically limit as an embodiment concerning bonding of the optical member of this invention and the said other optical member which is the case of the said embodiment, For example, (1) the optical member of this invention and the optical member of this invention through the adhesive sheet of this invention, An embodiment in which the another optical member is bonded, (2) an embodiment in which the pressure-sensitive adhesive sheet of the present invention including or constituting the optical member is bonded to the other optical member, (3) the pressure-sensitive adhesive sheet of the present invention An embodiment in which an optical member is bonded to a member other than an optical member through (4) an embodiment in which the pressure-sensitive adhesive sheet of the present invention including or constituting an optical member is bonded to a member other than the optical member, etc. are mentioned. . In addition, in the embodiment of the above (2), the pressure-sensitive adhesive sheet of the present invention is preferably a double-sided pressure-sensitive adhesive sheet in which the base material is an optical member (eg, an optical film).

Next, with reference to the schematic diagram of FIG. 2, a specific example concerning a particularly preferable form of the touch panel of the present invention will be described.

2A shows a touch panel 2 having a transparent substrate 12a, an adhesive sheet 10a, a transparent conductive film 11, an adhesive sheet 10b, and a transparent substrate 12b in contact with each other in this order. ) Is described. The transparent conductive film 11 is provided with the metal wiring 3 on the side of the adhesive sheet 10a, and the adhesive sheet 10a is on the surface of the transparent conductive film 11 on the side with the metal wiring 3 Is glued. The transparent substrate 12a and the transparent substrate 12b are preferably glass, and the transparent conductive film 11 is preferably PET-ITO. The pressure-sensitive adhesive sheet 10b may or may not be the pressure-sensitive adhesive sheet of the present invention, but is preferably the pressure-sensitive adhesive sheet of the present invention.

In Fig. 2B, a touch panel 2 having a transparent substrate 12a, an adhesive sheet 10, a polarizing plate 14a, a transparent substrate 12b, and a polarizing plate 14b in contact with each other in this order is described. Has been. The transparent substrate 12a is provided with the metal wiring 3 on the surface of the adhesive sheet 10 side, and the adhesive sheet 10 is adhered on the surface of the transparent substrate 12a on the side with the metal wiring 3 . The transparent substrate 12a is preferably a cover glass sensor, and the transparent substrate 12b is preferably a glass display panel such as an LCD.

In Fig. 2C, a transparent substrate 12a, an adhesive sheet 10a, a film sensor 13, an adhesive sheet 10b, a polarizing plate 14a, a transparent substrate 12b, and a polarizing plate 14b are arranged in this order. A touch panel 2 in contact with each other is described. The film sensor 13 is provided with the metal wiring 3 on the side of the adhesive sheet 10a, and the adhesive sheet 10a is adhered on the side of the film sensor 13 with the metal wiring 3 . The transparent substrate 12a is preferably glass, and the transparent substrate 12b is preferably a glass display panel such as an LCD. Although the pressure-sensitive adhesive sheet 10b may or may not be composed of the optical pressure-sensitive adhesive layer of the present invention, it is preferably composed of the optical pressure-sensitive adhesive layer of the present invention.

In Fig. 2(D), a transparent substrate 12a, an adhesive sheet 10a, a film sensor 13, an adhesive sheet 10b, a hard coating film 15, an adhesive sheet 10c, a polarizing plate 14a, and transparent A touch panel 2 having a substrate 12b and a polarizing plate 14b in contact with each other in this order is described. The film sensor 13 is provided with the metal wiring 3 on the side of the adhesive sheet 10a, and the adhesive sheet 10a is adhered on the side of the film sensor 13 with the metal wiring 3 . The transparent substrate 12a is preferably glass, the transparent substrate 12b is preferably a glass display panel such as an LCD, and the hard coating film 15 is preferably a hard-coated PET film. The pressure-sensitive adhesive sheets 10b and 10c may or may not be composed of the optical pressure-sensitive adhesive layer of the present invention, respectively, but it is preferable that they are composed of the optical pressure-sensitive adhesive layer of the present invention.

2E shows an optical member 4 having a transparent substrate 12a, an adhesive sheet 10a, a film sensor 13, an adhesive sheet 10b, and a hard coating film 15 in a state in contact with each other in this order. ) And an optical member 5 having a polarizing plate 14a, a transparent substrate 12b, and a polarizing plate 14b in contact with each other in this order is described. The optical member 4 and the optical member 5 have a positional relationship in which the hard coating film 15 and the polarizing plate 14a face each other. The hard coating film 15 does not contact the polarizing plate 14a, and an air layer is formed between the hard coating film 15 and the polarizing plate 14a. The film sensor 13 is provided with a metal wiring 3 on the side of the adhesive sheet 10a side, and the adhesive sheet 10a is adhered on the side of the film sensor 13 with the metal wiring 3 have. The transparent substrate 12a is preferably glass, the transparent substrate 12b is preferably a glass display panel such as an LCD, and the hard coating film 15 is preferably a hard-coated PET film. The pressure-sensitive adhesive sheets 10b and 10c may or may not be composed of the optical pressure-sensitive adhesive layer of the present invention, respectively, but it is preferable that they are composed of the optical pressure-sensitive adhesive layer of the present invention.

In addition, although it does not specifically limit as a metal wiring pattern (a wiring example of a metal wiring), For example, the metal wiring pattern shown in FIG. 7 is mentioned. 7 is a schematic plan view showing an example of a metal wiring pattern. In Fig. 7, 71a to 76a are metal wirings (pattern wirings), 71b to 76b are metal wirings (pattern wirings), and 81 to 86 are electrodes (transparent electrodes). Each electrode is connected to a metal wiring. For example, the electrode 81 is connected to the metal wiring 71a and the metal wiring 72b. In Fig. 7, each electrode is patterned in a rectangle, but the shape of the electrode is not limited to a rectangle. In Fig. 7, each electrode is connected to the metal wiring at two locations, but the number of connection points of the metal wiring in the electrode is not particularly limited. For example, the electrode may be connected to the metal wiring at one place, and may be connected to the metal wiring at three or more places. Further, if necessary, the metal wiring may be connected to a control means such as an IC.

The method of forming the metal wiring pattern is not particularly limited, but a method of removing the metal layer formed in advance by etching or the like, a printing method, or the like may be mentioned.

[Example]

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited at all by these examples.

(Preparation Example 1 of acrylic polymer)

Dicyclopentanyl methacrylate (DCPMA, dicyclopentanyl methacrylate) 60 parts by weight, methyl methacrylate (MMA, methyl methacrylate) 40 parts by weight, α-thioglycerol as a chain transfer agent 3.5 parts by weight and toluene as a polymerization solvent 100 parts by weight was put into a four-necked flask, and these were stirred at 70° C. for 1 hour in a nitrogen atmosphere. Next, 0.2 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator was put into a four-neck flask, reacted at 70°C for 2 hours, and then reacted at 80°C for 2 hours. Thereafter, the reaction solution was put in a 130° C. temperature atmosphere, and toluene, a chain transfer agent, and an unreacted monomer were dried and removed to obtain a solid acrylic polymer. In addition, the acrylic polymer was referred to as "acrylic polymer (B-1)".

In addition, the weight average molecular weight (Mw) of the acrylic polymer (B-1) was 5.1×10 ³ .

[Example 1]

In a monomer mixture consisting of 68 parts by weight of 2-ethylhexyl acrylate (2EHA), 14.5 parts by weight of N-vinyl-2-pyrrolidone (NVP) and 17.5 parts by weight of 2-hydroxyethyl acrylate (HEA), a photopolymerization initiator (Brand name ``Irgacure 184'', BASF) 0.035 parts by weight and a photopolymerization initiator (brand name ``Irgacure 651'', BASF) 0.035 parts by weight, after mixing, the viscosity ( BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30° C.) was irradiated with ultraviolet rays until about 20 Pa·s, to obtain a prepolymer composition in which a part of the monomer component was polymerized.

Next, 100 parts by weight of the prepolymer composition, 5 parts by weight of the acrylic polymer (B-1), 0.075 parts by weight of hexanediol diacrylate (HDDA), and a silane coupling agent (trade name "KBM-403", Shin-Etsu Chemical Cogyo Co., Ltd. product) 0.3 parts by weight and 1,2,3-benzotriazole (trade name "BT-120", Johoku Chemical Co., Ltd. product) 0.05 parts by weight were added and mixed, and an adhesive composition (before curing) Composition) was obtained.

The pressure-sensitive adhesive composition was applied on a polyethylene terephthalate (PET) separator (trade name “MRF50”, manufactured by Mitsubishi Jushi Corporation) so that the final thickness (the thickness of the adhesive layer) was 100 μm, and a coating layer (adhesive composition layer) Formed. Subsequently, a PET separator (trade name "MRF38", manufactured by Mitsubishi Jushi Co., Ltd.) was installed on the coating layer, and the coating layer was covered to block oxygen. And a laminate of MRF50/coating layer (adhesive composition layer)/MRF38 was obtained.

Next, the laminate was irradiated with ultraviolet rays having an ^{illuminance of 5 mW/cm 2} for 300 seconds with a black light (manufactured by Toshiba Co., Ltd.) from the upper surface of the laminate (MRF38 side). Further, a drying treatment was performed for 2 minutes in a dryer at 90°C to volatilize the residual monomer. And an inorganic material double-sided pressure-sensitive adhesive sheet including only the pressure-sensitive adhesive layer and in which both sides of the pressure-sensitive adhesive layer were protected by a separator was obtained.

[Example 2]

In the same manner as in Example 1, except that the amount of 1,2,3-benzotriazole used was 0.1 parts by weight, an inorganic double-sided adhesive sheet was obtained.

[Example 3]

In the same manner as in Example 1, except that the amount of 1,2,3-benzotriazole used was 0.2 parts by weight, an inorganic double-sided adhesive sheet was obtained.

[Example 4]

An inorganic double-sided pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1, except that the amount of 1,2,3-benzotriazole was used in an amount of 0.3 parts by weight and the thickness of the pressure-sensitive adhesive layer was 50 μm.

[Example 5]

In the same manner as in Example 1, except that the amount of 1,2,3-benzotriazole used was 0.3 parts by weight, an inorganic double-sided adhesive sheet was obtained.

[Example 6]

An inorganic double-sided pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the amount of 1,2,3-benzotriazole was used in an amount of 0.3 parts by weight and the thickness of the pressure-sensitive adhesive layer was 150 μm.

[Example 7]

An inorganic double-sided pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the amount of 1,2,3-benzotriazole was used in an amount of 0.3 parts by weight and the thickness of the pressure-sensitive adhesive layer was 250 μm.

[Example 8]

In the same manner as in Example 1, except that the amount of 1,2,3-benzotriazole used was 0.5 parts by weight, an inorganic double-sided adhesive sheet was obtained.

[Example 9]

In the same manner as in Example 1, except that the amount of 1,2,3-benzotriazole used was 2.0 parts by weight, an inorganic double-sided adhesive sheet was obtained.

[Example 10]

In the same manner as in Example 1 except that 0.5 parts by weight of 5-methylbenzotriazole (trade name "5M-BTA", manufactured by Johoku Chemical Co., Ltd.) was used instead of 1,2,3-benzotriazole, inorganic A double-sided adhesive sheet was obtained.

[Example 11]

In place of 1,2,3-benzotriazole, 0.5 parts by weight of 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole (trade name "BT-LX", Johoku Chemical Co., Ltd. Except having used), it carried out similarly to Example 1, and obtained the inorganic material double-sided adhesive sheet.

[Example 12]

Instead of 1,2,3-benzotriazole, 0.5 parts by weight of 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole (trade name "TT-LX", Johoku Chemical Co., Ltd. Except having used), it carried out similarly to Example 1, and obtained the inorganic material double-sided adhesive sheet.

[Example 13]

The amount of 1,2,3-benzotriazole used was 0.3 parts by weight, and the composition of the monomer mixture was 61 parts by weight of 2-ethylhexyl acrylate (2EHA), and 14 parts by weight of N-vinyl-2-pyrrolidone (NVP). Parts and 4-hydroxybutyl acrylate (4HBA) 25 parts by weight, and in the same manner as in Example 1 except that the amount of hexanediol diacrylate (HDDA) was set to 0.060 parts by weight, an inorganic double-sided adhesive sheet was obtained.

[Example 14]

In the same manner as in Example 1, except that the amount of 1,2,3-benzotriazole used was 5.0 parts by weight, an inorganic double-sided adhesive sheet was obtained.

[Example 15]

1,2,3-benzotriazole is used in an amount of 0.5 parts by weight, an acrylic polymer (B-1) is not used, and the composition of the monomer mixture is 2-ethylhexyl acrylate (2EHA) 78 parts by weight, N- An inorganic double-sided adhesive sheet was obtained in the same manner as in Example 1 except that 18 parts by weight of vinyl-2-pyrrolidone (NVP) and 4 parts by weight of 2-hydroxyethyl acrylate (HEA) were used.

[Example 16]

Example 1 except that 0.250 parts by weight of hexanediol diacrylate (HDDA) and 0.3 parts by weight of 1,2,3-benzotriazole (trade name "BT-120", manufactured by Johoku Chemical Co., Ltd.) It carried out similarly to the same, and obtained the adhesive composition (composition before hardening).

And it carried out similarly to Example 1 using this composition, and obtained the inorganic material double-sided pressure-sensitive adhesive sheet containing only the pressure-sensitive adhesive layer and having both sides of the pressure-sensitive adhesive layer protected by a separator.

[Example 17]

61 parts by weight of 2-ethylhexyl acrylate (2EHA), 14 parts by weight of N-vinyl-2-pyrrolidone (NVP), 3 parts by weight of 2-hydroxyethyl acrylate (HEA), and 4-hydroxybutyl acrylate (4HBA) A prepolymer composition in which a part of the monomer component was polymerized was obtained in the same manner as in Example 1 except that a monomer mixture composed of 22 parts by weight was used.

Subsequently, to the prepolymer composition 100 parts by weight, 0.180 parts by weight of hexanediol diacrylate (HDDA), 0.3 parts by weight of a silane coupling agent (trade name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.3 parts by weight of 1,2,3-benzotriazole (trade name "BT-120", manufactured by Johoku Chemical Co., Ltd.) was added and mixed to obtain a pressure-sensitive adhesive composition (composition before curing).

And it carried out similarly to Example 1 using this adhesive composition, and obtained the inorganic material double-sided adhesive sheet which contained only an adhesive layer, and both surfaces of the adhesive layer were protected by a separator.

[Example 18]

61 parts by weight of 2-ethylhexyl acrylate (2EHA), 14 parts by weight of N-vinyl-2-pyrrolidone (NVP), 3 parts by weight of 2-hydroxyethyl acrylate (HEA), and 4-hydroxybutyl acrylate (4HBA) A prepolymer composition in which a part of the monomer component was polymerized was obtained in the same manner as in Example 1 except that a monomer mixture composed of 22 parts by weight was used.

Then, to 100 parts by weight of the prepolymer composition, 0.060 parts by weight of hexanediol diacrylate (HDDA), 0.3 parts by weight of a silane coupling agent (trade name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd.) and 1, 0.3 parts by weight of 2,3-benzotriazole (trade name "BT-120", manufactured by Johoku Chemical Co., Ltd.) was added and mixed to obtain a pressure-sensitive adhesive composition (composition before curing).

And it carried out similarly to Example 1 using this composition, and obtained the inorganic material double-sided pressure-sensitive adhesive sheet containing only the pressure-sensitive adhesive layer and having both sides of the pressure-sensitive adhesive layer protected by a separator.

[Comparative Example 1]

Except having not used 1,2,3-benzotriazole, it carried out similarly to Example 1, and obtained the inorganic material double-sided adhesive sheet.

[Comparative Example 2]

In place of 1,2,3-benzotriazole, 0.5 parts by weight of pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (trade name "irganox ( Irganox) 1010" and BASF (made by BASF) were carried out in the same manner as in Example 1 to obtain an inorganic double-sided adhesive sheet.

[Comparative Example 3]

1,2,3-benzotriazole is not used, acrylic polymer (B-1) is not used, and the composition of the monomer mixture is 90 parts by weight of 2-ethylhexyl acrylate (2EHA) and 10 parts by weight of acrylic acid (AA) In addition, an inorganic double-sided adhesive sheet was obtained in the same manner as in Example 1 except that 0.070 parts by weight of dipentaerythritol hexaacrylate (DPHA) was used instead of 0.075 parts by weight of hexanediol diacrylate (HDDA).

[Comparative Example 4]

The amount of 1,2,3-benzotriazole is 0.5 parts by weight, and the composition of the monomer mixture is 90 parts by weight of 2-ethylhexyl acrylate (2EHA) and acrylic acid ( AA) In the same manner as in Example 1, except that 0.070 parts by weight of dipentaerythritol hexaacrylate (DPHA) was used instead of 0.075 parts by weight of hexanediol diacrylate (HDDA), an inorganic double-sided adhesive sheet was obtained.

[Comparative Example 5]

Lauryl acrylate (LA) 60 parts by weight, 2-ethylhexyl acrylate (2EHA) 22 parts by weight, N-vinyl-2-pyrrolidone (NVP) 10 parts by weight and 4-hydroxybutyl acrylate (4HBA) In the same manner as in Example 1 except for using a monomer mixture composed of 8 parts by weight, a prepolymer composition in which a part of the monomer component was polymerized was obtained.

Next, to 100 parts by weight of the prepolymer composition, 0.035 parts by weight of dipentaerythritol hexaacrylate (DPHA) and 0.3 parts by weight of a silane coupling agent (trade name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd.) were added. It mixed and obtained the pressure-sensitive adhesive composition (composition before curing).

And it carried out similarly to Example 1 using this composition, and obtained the inorganic material double-sided pressure-sensitive adhesive sheet containing only the pressure-sensitive adhesive layer and having both sides of the pressure-sensitive adhesive layer protected by a separator.

[Comparative Example 6]

1,2,3-benzotriazole is used in an amount of 0.3 parts by weight, and the composition of the monomer mixture is lauryl acrylate (LA) 60 parts by weight, 2-ethylhexyl acrylate (2EHA) 22 parts by weight, N-vinyl 10 parts by weight of -2-pyrrolidone (NVP) and 8 parts by weight of 4-hydroxybutyl acrylate (4HBA), and instead of 0.075 parts by weight of hexanediol diacrylate (HDDA), dipentaerythritol hexaacrylate ( DPHA) Except having used 0.035 parts by weight, it carried out similarly to Example 1, and obtained the inorganic material double-sided adhesive sheet.

[Characteristic evaluation]

About the inorganic material double-sided adhesive sheet of an Example and a comparative example, the following measurement or evaluation was performed. The evaluation results are shown in Table 2.

(1) metal corrosiveness

On the substrate side of a film with a copper layer formed on one side of a cycloolefin (COP) substrate (trade name “Zeonoa”, manufactured by Nippon Xeon Corporation, thickness 100 μm) (hereinafter sometimes referred to as “copper film”) One separator of the double-sided pressure-sensitive adhesive sheet was peeled off, and the double-sided pressure-sensitive adhesive sheet was pressed and bonded under the conditions of a 2 kg roller, one reciprocating pressure, to obtain a structure A having a laminated structure of a copper film and a double-sided pressure-sensitive adhesive sheet.

Subsequently, after the structure A was cut into a size of 15 mm×15 mm, the separator of the double-sided pressure-sensitive adhesive sheet was peeled off, and the soda glass plate (25 mm×25 mm, thickness 0.7 mm) was pressed and bonded to a soda glass plate (25 mm×25 mm, thickness 0.7 mm) under pressure bonding conditions of one round trip. Then, a structure B having a laminated structure of a copper film, a double-sided adhesive sheet, and glass was obtained.

Separately, a film in which an antireflection treatment layer was formed on one side of a triacetylcellulose (TAC) substrate (trade name "DSC-03", manufactured by Dinippon Inssu Co., Ltd., a thickness of 90 μm, hereinafter referred to as "AR film". In some cases), one separator of the same double-sided pressure-sensitive adhesive sheet as described above is peeled off, the double-sided pressure-sensitive adhesive sheet is crimped and bonded under conditions of a 2 kg roller, one reciprocating pressure, and the laminated structure of the AR film and the double-sided pressure-sensitive adhesive sheet The structure C was obtained. Next, after cutting the structure C into a size of 10 mm × 10 mm, the separator of the double-sided adhesive sheet was peeled off, and the central part of the copper surface side of the structure B was pressed and bonded under the conditions of a 2 kg roller, 1 reciprocating compression, and then bonded to the AR film. A structure D having a laminated structure consisting of five layers of a double-sided adhesive sheet, a copper film, a double-sided adhesive sheet, and glass was obtained.

After allowing to stand for 30 minutes in an atmosphere of 23°C and 50% RH, the structure D was put into an autoclave, followed by autoclaving for 15 minutes under the conditions of a temperature of 50°C and a pressure of 0.5 MPa. After the autoclave treatment, the structure D was taken out from the autoclave, and left to stand for 24 hours in an atmosphere of 23°C and 50% RH (RH: relative humidity).

As a device for measuring the sheet resistance value of the copper layer of the structure D, a Hall effect measuring device (trade name "HL5500PC", manufactured by Toho Technology Co., Ltd.) was used. The sheet resistance value (initial sheet resistance: R ₀ ) of the structure D was measured in an atmosphere of 23° C. and 50% RH, respectively.

After the measurement, in order to prevent copper oxidation at the portion to which the measurement probe is applied, the structure D was injected for 300 hours in an environment of 85° C. and 85% RH while covering the copper surface to which the AR film was not attached. After taking out, the temperature and humidity were adjusted for 24 hours in an environment of 23°C and 50% RH. After visually checking each color change of copper from the beginning, sheet resistance values (sheet resistance after test: R ₁ ) were measured in an atmosphere of 23°C and 50% RH, respectively.

From the initial sheet resistance value (R _{0 ) and the sheet resistance value (R 1} ) after the test after 300 hours in an 85°C, 85% RH environment, the rate of change (T) of the sheet resistance value was obtained by the following calculation formula.

Rate of change T(%)=(R ₁ -R ₀ )/R ₀ ×100

If the rate of change (T) of the sheet resistance value was less than 150%, it was set as pass ("(circle)"), and it was judged that it has good corrosion prevention performance. On the other hand, if the resistance value change rate from the initial stage was 150% or more, it was set as rejection ("x"), and it was judged that it did not have good corrosion prevention performance.

(2) Total light transmittance and haze

One separator is peeled off from the double-sided adhesive sheet, and the double-sided adhesive sheet is placed in a slide glass (manufactured by Matsunami Glass Co., Ltd., "White Polishing No. 1", thickness 0.8 to 1.0 mm, total light transmittance 92%, haze 0.2). %), and the other separator was peeled off to prepare a test piece having a layered configuration of a double-sided pressure-sensitive adhesive sheet (adhesive layer)/slide glass.

The total light transmittance and haze in the visible region of the test piece were measured using a haze meter (device name "HM-150", manufactured by Shikisai Murakami, Kijutsu Kenkyusho Co., Ltd.).

(3) 180° peel adhesion (180° peel adhesion to glass plate)

A sheet piece having a length of 100 mm and a width of 20 mm was cut out from the double-sided adhesive sheet. Subsequently, one separator was peeled from the sheet piece, and a PET film (brand name "Lumor S-10", thickness 25 µm, manufactured by Toray Corporation) was attached ((supported)). Subsequently, the other separator was peeled off, and the test plate was crimped with a 2 kg roller and one reciprocating crimp condition. Then, it aged for 30 minutes in an atmosphere of 23 degreeC and 50% RH. After aging, a tensile tester (equipment name "Autograph AG-IS", manufactured by Shimadzu Corporation) was used, and in accordance with JIS Z0237, a tensile speed of 300 mm/min, a peel angle in an atmosphere of 23°C and 50% RH The adhesive sheet was removed from the test plate under conditions of 180°, and the 180° peel adhesion (N/20mm) was measured.

As the test plate, a glass plate (trade name "soda lime glass #0050", manufactured by Matsunami Glass Co., Ltd.) was used.

(4) Humidification cloudiness resistance

After cutting the double-sided adhesive sheet into a size of 45 mm in width and 90 mm in length, one separator was peeled off, and then pressed onto a soda glass plate (manufactured by Matsunami Glass Co., Ltd., 100 mm x 50 mm, thickness 0.7 mm) with a 2 kg roller, one round trip. It was bonded by pressing under conditions. Subsequently, the separator was peeled from the bonded double-sided pressure-sensitive adhesive sheet, and the same glass plate as described above was bonded with a vacuum bonding device under conditions of a surface pressure of 0.2 MPa, a vacuum degree of 30 Pa, and an adhesion time of 10 seconds. An evaluation sample having a constitution was obtained.

Subsequently, the evaluation sample was put into an autoclave and subjected to an autoclave treatment for 15 minutes under conditions of a temperature of 50°C and a pressure of 0.5 MPa. After the autoclave treatment, an evaluation sample was taken out and left to stand for 24 hours in an atmosphere of 23°C and 50% RH (RH: relative humidity).

After putting the evaluation sample in a high-temperature, high-humidity environment of 60°C and 95% RH for 300 hours, it is taken out and left to stand in an environment of 23°C and 50% RH for 24 hours, and then the appearance of the evaluation sample is visually observed, according to the following evaluation criteria. Therefore, moisture-resistant cloudiness was evaluated.

Evaluation standard

A: No whitening

B: White flowers are visible only in the four corners of the double-sided adhesive sheet

C: Whitening is seen on the entire surface of the double-sided adhesive sheet

(5) foaming and peeling resistance

ITO (oxide of indium and tin) on one side of a cycloolefin (COP) substrate (trade name "Zeonoa", manufactured by Nippon Xeon Co., Ltd., thickness of 100 μm) by peeling one separator of the double-sided adhesive sheet The layered film (hereinafter sometimes referred to as “COP-ITO film”) was bonded to the surface on the side of the ITO layer under pressure bonding conditions of 2 kg rollers and one round trip. Then, a structure A'having a laminated structure of a COP-ITO film and a double-sided adhesive sheet was obtained.

Subsequently, the separator of the double-sided pressure-sensitive adhesive sheet in the structure A'is peeled off, and the structure A'is pressed on the side of the stepped glass (see Figs. 4 to 6) on the side with a step difference of 2 kg roller, under pressure bonding conditions of one reciprocation. And joined. Then, a structure B'having a laminated structure of a COP-ITO film, a double-sided adhesive sheet, and a stepped glass was obtained.

After allowing the structure B'to stand in an atmosphere of 23°C and 50% RH for 1 hour, the structure B'was put into an autoclave, followed by autoclaving for 15 minutes at a temperature of 50°C and a pressure of 0.5 MPa. After the autoclave treatment, the structure B'was taken out from the autoclave, and the structure B'was put into a dryer set at 85°C and left for 24 hours.

Thereafter, the structure B'was taken out from the dryer, and left to stand for 30 minutes in an atmosphere of 23°C and 50% RH. Then, the presence or absence of foaming (foaming including foaming due to foreign matter) or peeling in the structure B'was confirmed with a microscope. And it evaluated according to the following evaluation criteria.

Evaluation standard

A: No foaming or peeling was observed

B: Foaming is seen only due to foreign matter having a size of 100 μm or more

C: Foaming is seen due to a foreign material having a size of less than 100 μm

D: Regardless of the presence or absence of foreign matter, foaming or peeling is observed

In addition, in the evaluation of the above (5) foaming and peeling resistance, instead of the COP-ITO film, a film in which an ITO (oxide of indium and tin) layer was formed on one side of a polyethylene terephthalate (PET) substrate (thickness 50 μm) ( Hereinafter, it also carried out about the case of using the case where it may be called "PET-ITO film").

(6) Visual evaluation of the pattern

Film formation by sputtering was performed on one side of a film substrate (a 23 μm thick biaxially stretched polyethylene terephthalate (PET) film, brand name ``Diafoil'', manufactured by Mitsubishi Jushi Co., Ltd.), and had a thickness of 22 nm. An ITO film (ITO layer) was formed to obtain a film (ITO film) in which an ITO film was formed on one side of the film substrate.

Next, the ITO film was cut into a sheet having a width of 6 cm and a length of 10 cm. A plurality of polyimide tapes having a width of 2 mm were bonded to the surface of the cut-out ITO film at intervals of 2 mm. The bonding of the polyimide tape was performed so that the width direction of the ITO film cut in the length direction of the polyimide tape became the same direction. After bonding of the polyimide tape, it was immersed for 10 minutes in a 5 wt% aqueous hydrochloric acid solution heated at 50°C. This immersion corresponds to an etching treatment for the purpose of removing the ITO film of the non-masking portion (the portion to which the polyimide tape is not bonded). After immersion in a 5 wt% aqueous hydrochloric acid solution, it was washed with water by immersing in a sufficient amount of pure water, and the polyimide tape was slowly peeled off.

And it dried by heating for 5 minutes in 70 degreeC oven, and obtained the film (ITO pattern film) which has a patterned ITO film.

The ITO pattern film has a pattern forming portion in which an ITO film is formed, and a pattern opening from which the ITO film is removed.

After installing copper wires so as to be connected to the ends of each pattern from the periphery of the surface on which the ITO pattern of the ITO pattern film is formed and from the periphery, a glass plate is bonded to the surface through a double-sided adhesive sheet, and a test piece (glass plate/double-sided A laminate having a laminated structure of an ITO pattern film to which an adhesive sheet/copper wiring was attached) was obtained.

In addition, the copper wiring provided so as to connect to the end of each pattern from the periphery of the surface on which the ITO pattern of the ITO pattern film is formed and the periphery is common to the form shown in FIG. 7.

Next, the test piece was allowed to stand for 48 hours in an environment of 85°C and 85% RH. About the test piece after leaving to stand, the easiness of visibility of a pattern was visually confirmed, and it evaluated by the following evaluation criteria.

Evaluation standard

Very good (⊚): It is difficult to discriminate between the pattern formation portion and the pattern opening, so that the pattern is hardly visible.

Good (○): The pattern formation portion and the pattern opening can be slightly discriminated, and the pattern is slightly visible.

Defect (x): The pattern formation part and the pattern opening can be clearly discriminated, and the pattern is clearly visible.

According to the optical pressure-sensitive adhesive layer of the present invention, it is possible to have adhesion reliability, transparency, and anti-corrosion effect, and it is possible to suppress the occurrence of bending in a high-temperature environment, and as a result of reducing the process by eliminating the need for coating of the protective layer, cost Since this is reduced and the yield is improved, it is useful for a display device such as a liquid crystal display (LCD) or an input device such as a touch panel, particularly for a touch panel application.

1, 4, 5: optical member
2: touch panel
3: metal wiring
10, 10a, 10b, 10c: adhesive sheet
11: transparent conductive film
12a, 12b: transparent substrate
13: film sensor
14a, 14b: polarizing plate
15: hard coating film
20: Stepped glass (step test piece)
21: glass plate
22: step
6: laminate
61: support
62: metal film
71a, 72a, 73a, 74a, 75a, 76a: metal wiring (pattern wiring)
71b, 72b, 73b, 74b, 75b, 76b: metal wiring (pattern wiring)
81, 82, 83, 84, 85, 86: electrode (transparent electrode)

Claims (14)

delete Contains an acrylic polymer (A) and a rust inhibitor,
In the acrylic polymer (A), the content of the carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A) is 0 to 0.05 parts by weight based on the total amount (100 parts by weight) of the monomer component constituting the acrylic polymer (A). ,
The acrylic polymer (A) contains 5 to 40 parts by weight of a hydroxyl group-containing monomer with respect to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A),
The acrylic polymer (A) contains 5 to 40 parts by weight of a nitrogen atom-containing monomer with respect to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A),
The acrylic polymer (A) contains 30 to 90 parts by weight of an alkyl (meth)acrylate based on the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A),
The acrylic polymer (A) contains 0.001 to 0.5 parts by weight of a polyfunctional monomer based on the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A),
0.02 to 3 parts by weight of a benzotriazole compound as a rust inhibitor based on the total amount (100 parts by weight) of the monomer component constituting the acrylic polymer (A),
An optical pressure-sensitive adhesive layer, characterized in that the elastic modulus at 85° C. is 5.0×10 ^{4 Pa or more.} delete delete delete The optical pressure-sensitive adhesive layer according to claim 2, wherein the haze (according to JIS K7136) is 1.0% or less. The optical pressure-sensitive adhesive layer according to claim 2 or 6, wherein the total light transmittance (according to JIS K7361-1) is 90% or more. A pressure-sensitive adhesive sheet having an optical pressure-sensitive adhesive layer according to claim 2 or 6. The pressure-sensitive adhesive sheet according to claim 8, wherein the 180° peel adhesion to the glass plate is 8N/20mm or more. The pressure-sensitive adhesive sheet according to claim 8, having a thickness of 12 to 350 µm. An optical member having at least a pressure-sensitive adhesive sheet and a substrate according to claim 8, wherein the substrate has a metal wire on at least one side, and the pressure-sensitive adhesive sheet is adhered on a side of the substrate having the metal wire. absence. The optical member according to claim 11, wherein the metal wiring is a copper wiring. A touch panel having at least a pressure-sensitive adhesive sheet and a substrate according to claim 8, wherein the substrate has a metal wire on at least one side, and the pressure-sensitive adhesive sheet is adhered on a side of the substrate having the metal wire . The touch panel according to claim 13, wherein the metal wiring is a copper wiring.

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