WO2022244813A1

WO2022244813A1 - Optical pressure-sensitive adhesive sheet, optical laminate, and image display device

Info

Publication number: WO2022244813A1
Application number: PCT/JP2022/020709
Authority: WO
Inventors: 普史形見; 大輔水野; 虎太朗雨宮
Original assignee: 日東電工株式会社
Priority date: 2021-05-21
Filing date: 2022-05-18
Publication date: 2022-11-24
Also published as: KR20240012430A; TW202302797A

Abstract

A purpose of the present invention is to provide: an optical pressure-sensitive adhesive sheet that has a layered structure including a pressure-sensitive adhesive layer which is less apt to have failures regarding transparency, appearance, or durability, exhibits a low surface resistivity, and has excellent antistatic performance; and an optical laminate.　This optical pressure-sensitive adhesive sheet has a layered structure comprising: a substrate 1 having a first surface 1a and a second surface 1b; and a pressure-sensitive adhesive layer 2 superposed on the first surface 1a of the substrate 1. The pressure-sensitive adhesive layer 2 is formed from a pressure-sensitive adhesive composition comprising: an antistatic agent; and an acrylic polymer (A), a mixture of monomers for constituting the acrylic polymer (A), or a partial polymer of a mixture of monomers for constituting the acrylic polymer (A). The antistatic agent is characterized by being an ionic compound having, in the molecule, a functional group capable of forming a covalent bond with the acrylic polymer (A).

Description

Optical pressure-sensitive adhesive sheet, optical laminate, and image display device

The present invention relates to an optical pressure-sensitive adhesive sheet, an optical laminate, and an image display device. More specifically, an optical pressure-sensitive adhesive sheet having a laminated structure with a pressure-sensitive adhesive layer having excellent antistatic properties, an optical laminate in which the optical pressure-sensitive adhesive sheet and an optical member are laminated, and the optical pressure-sensitive adhesive sheet and an image display panel It relates to an image display device in which and are laminated.

In recent years, display devices such as liquid crystal displays (LCDs) and input devices such as touch panels have been widely used in various fields. In manufacturing such display devices and input devices, adhesive sheets are used for bonding optical members. For example, transparent adhesive sheets are used for laminating optical members in various display devices such as touch panels. In recent years, in order to improve production efficiency, it is widely practiced to transport optical pressure-sensitive adhesive sheets in which a pressure-sensitive adhesive layer is laminated on a polarizing film, a retardation film, a transparent cover member such as a cover glass, and other various optical members. there is

In the manufacture of these display devices and input devices, when the optical pressure-sensitive adhesive sheet is attached to the display device, the release sheet protecting the pressure-sensitive adhesive layer is peeled off. occurs. The generated static electricity affects the orientation of the display cells of the display device and causes display defects. As means for suppressing the generation of such static electricity, an antistatic agent is added to reduce the surface resistivity of the pressure-sensitive adhesive layer (eg, Patent Documents 1 to 3).

JP 2020-187365 A JP 2019-56115 A WO2018/008712

In recent years, due to higher image quality, the influence of static electricity on display devices having high-density display cells has increased. For example, about 10 ¹⁰ Ω/□) is required. In addition, due to the demand for thinner and lighter display devices, thinner pressure-sensitive adhesive sheets are also required. It is

However, if a large amount of antistatic agent is blended into the adhesive layer, the compatibility with the adhesive layer may decrease, or the antistatic agent may precipitate on the surface of the adhesive layer, resulting in transparency such as white turbidity, especially in a hot and humid environment. and appearance defects may occur. In addition, foaming, peeling, and the like may occur in a moist and hot environment, resulting in durability problems.

Accordingly, an object of the present invention is to provide an optical pressure-sensitive adhesive having a laminated structure in which pressure-sensitive adhesive layers having low surface resistivity, excellent antistatic performance, and excellent antistatic performance are unlikely to cause defects in transparency, appearance, and durability. It is to provide a sheet.
Another object of the present invention is to provide an optical adhesive having a laminated structure in which a pressure-sensitive adhesive layer having low surface resistivity, excellent antistatic performance, which is less likely to cause defects in transparency, appearance, and durability, is laminated. An object of the present invention is to provide an optical laminate in which a pressure-sensitive adhesive sheet for optical devices and an optical member are laminated.
Another object of the present invention is to provide an optical adhesive having a laminated structure in which a pressure-sensitive adhesive layer having low surface resistivity, excellent antistatic performance, which is less likely to cause defects in transparency, appearance, and durability, is laminated. An object of the present invention is to provide an image display device in which an adhesive sheet for image display and an image display panel are laminated.

Therefore, as a result of intensive studies by the present inventors in order to solve the above problems, an acrylic polymer is used as a base polymer constituting a pressure-sensitive adhesive layer that the optical pressure-sensitive adhesive sheet has in a laminated structure, and as an antistatic agent, By using an ionic compound having a functional group capable of forming a covalent bond with the acrylic polymer in the molecule, defects in transparency, appearance, and durability are less likely to occur, and low surface resistivity is exhibited, resulting in excellent antistatic properties. The inventors have found that a pressure-sensitive adhesive layer having performance can be formed, and completed the present invention.

That is, the first aspect of the present invention has a laminated structure in which a substrate having a first surface and a second surface and an adhesive layer is laminated on the first surface of the substrate, and the adhesive layer is , an antistatic agent, and a mixture of monomer components constituting the acrylic polymer (A) or a partially polymerized product of a mixture of monomer components constituting the acrylic polymer (A). We provide adhesive sheets for
Further, a second aspect of the present invention has a laminated structure in which a substrate having a first surface and a second surface and an adhesive layer is laminated on the first surface of the substrate, and the adhesive layer is , an optical pressure-sensitive adhesive sheet formed from a pressure-sensitive adhesive composition containing an antistatic agent and an acrylic polymer (A).
In the optical pressure-sensitive adhesive sheets of the first and second aspects of the present invention, the antistatic agent is an ionic compound having a functional group capable of forming a covalent bond with the acrylic polymer (A) in its molecule.

In the optical pressure-sensitive adhesive sheet of the first and second aspects of the present invention, the antistatic agent is an ionic compound having a functional group capable of forming a covalent bond with the acrylic polymer (A) in its molecule. , the ionic compound that constitutes the antistatic agent can form a covalent bond with the acrylic polymer (A). Defects in transparency and appearance due to precipitation of the antistatic agent on the surface of the agent layer are unlikely to occur, and foaming and peeling due to the antistatic agent in a moist and hot environment are unlikely to occur, and excellent durability is also preferable. . Therefore, the optical pressure-sensitive adhesive sheets of the first and second aspects of the present invention are less likely to cause defects in transparency, appearance and durability, exhibit low surface resistivity, and have excellent antistatic performance.

In the optical pressure-sensitive adhesive sheet of the first and second aspects of the present invention, the functional group that the antistatic agent has in the molecule includes (meth)acryloyloxy group, (meth)acryloylamino group, vinyl group, allyl group, It is preferably at least one selected from the group consisting of styryl groups, hydroxyl groups, amino groups, mercapto groups and epoxy groups. These functional groups are preferable in that they easily form a covalent bond with the acrylic polymer (A).

In the optical pressure-sensitive adhesive sheet of the first and second aspects of the present invention, it is preferable that the acrylic polymer (A) does not contain or substantially does not contain a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A). This configuration is preferable in that the optical pressure-sensitive adhesive sheets of the first and second aspects of the present invention can obtain an excellent effect of preventing corrosion of metal wiring.

In the optical pressure-sensitive adhesive sheets of the first and second aspects of the present invention, the pressure-sensitive adhesive composition preferably contains no or substantially no organic solvent. This configuration is preferable in that defects in appearance such as citrus peel are less likely to occur.

In the optical pressure-sensitive adhesive sheet of the first and second aspects of the present invention, the haze (according to JIS K7136) of the pressure-sensitive adhesive layer is preferably 1.0% or less. In addition, the total light transmittance (according to JIS K7361-1) of the front adhesive layer is preferably 90% or more. These configurations are preferable in terms of obtaining excellent transparency and excellent appearance.

The 180° peeling adhesive force at 23°C of the optical pressure-sensitive adhesive sheet of the first and second aspects of the present invention to a glass plate is preferably 4 N/20 mm or more. This configuration is preferable in that the adhesiveness to glass and the ability to prevent floating on steps are more excellent.

The thickness of the optical pressure-sensitive adhesive sheet of the first and second aspects of the present invention is preferably 12-350 μm. A configuration in which the thickness is equal to or greater than a certain value is preferable in that peeling at the step portion is less likely to occur. In addition, a configuration in which the thickness is equal to or less than a certain value is preferable in terms of making it easier to maintain an excellent appearance during manufacturing.

In the optical pressure-sensitive adhesive sheet of the first and second aspects of the present invention, the second surface of the base material is preferably subjected to antireflection treatment, antiglare treatment, hard coat treatment, and/or antistatic treatment. The configuration in which the second surface of the base material is subjected to antireflection treatment and / or antiglare treatment prevents deterioration of visibility due to reflection of external light and reflection of images, and adjusts appearance such as glossiness. It is preferable from the viewpoint of Further, the configuration in which the second surface of the base material is hard-coated is preferable in that the surface hardness and scratch resistance are improved. In addition, the configuration in which the second surface of the base material is antistatically treated suppresses static electricity from being charged to the optical pressure-sensitive adhesive sheet of the first and second aspects of the present invention, thereby preventing the optical pressure-sensitive adhesive sheet from being charged with static electricity. When used in an image display device, it is preferable in that display defects caused by static electricity can be suppressed.

A third aspect of the present invention provides an optical laminate in which the optical pressure-sensitive adhesive sheet of the first or second aspect of the present invention and an optical member are laminated. A fourth aspect of the present invention provides an image display device in which the optical pressure-sensitive adhesive sheet of the first or second aspect of the present invention and an image display panel are laminated. The optical layered body of the third aspect of the present invention and the image display device of the fourth aspect of the present invention are less likely to cause defects in transparency, appearance and durability, exhibit low surface resistivity, and are excellent in antistatic properties. Since the optical pressure-sensitive adhesive sheet of the first or second aspect of the present invention having performance is provided in a laminated structure, display defects due to static electricity are less likely to occur, which is preferable.

The optical pressure-sensitive adhesive sheet of the present invention is less likely to cause defects in transparency, appearance, and durability, exhibits low surface resistivity, and has excellent antistatic performance. Therefore, by using the optical pressure-sensitive adhesive sheet of the present invention for manufacturing an image display device, excellent transparency, appearance and durability can be maintained, and display defects due to static electricity can be suppressed. In addition, the optical laminate and the image display device having the optical pressure-sensitive adhesive sheet of the present invention in a laminated structure can maintain excellent transparency, appearance and durability, and can suppress display defects caused by static electricity.

FIG. 1 is a schematic diagram (cross-sectional view) showing one embodiment of the optical pressure-sensitive adhesive sheet of the present invention. FIG. 2 is a schematic diagram (cross-sectional view) showing one embodiment of the optical laminate of the present invention. FIG. 3 is a schematic diagram (sectional view) showing an embodiment of the image display device of the present invention.

The optical pressure-sensitive adhesive sheet of the first aspect of the present invention has a laminated structure in which a substrate having a first surface and a second surface and an adhesive layer is laminated on the first surface of the substrate, The agent layer is formed from a pressure-sensitive adhesive composition containing an antistatic agent and a mixture of monomer components constituting the acrylic polymer (A) or a partial polymer of a mixture of monomer components constituting the acrylic polymer (A). optical pressure-sensitive adhesive sheet.
Further, the optical pressure-sensitive adhesive sheet of the second aspect of the present invention has a laminated structure in which a substrate having a first surface and a second surface and a pressure-sensitive adhesive layer is laminated on the first surface of the substrate, The pressure-sensitive adhesive sheet for optical use, wherein the pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing an antistatic agent and an acrylic polymer (A).
In the first and second side optical pressure-sensitive adhesive sheets of the present invention, the antistatic agent is an ionic compound having in its molecule a functional group capable of forming a covalent bond with the acrylic polymer (A).

In addition, in this specification, the above-mentioned "mixture of monomer components" includes the case of being composed of a single monomer component and the case of being composed of two or more monomer components. In addition, the above-mentioned "partially polymerized mixture of monomer components" means a composition in which one or more of the constituent monomer components of the above-mentioned "mixture of monomer components" is partially polymerized. do.
In this specification, when simply referring to "acrylic polymer (A)", unless otherwise specified, "acrylic polymer (A)", "mixture of monomer components constituting acrylic polymer (A)", and ""partially polymerized mixture of monomer components constituting the acrylic polymer (A)" is also included.

In this specification, the optical pressure-sensitive adhesive sheets of the first and second aspects of the present invention may be collectively referred to as "the optical pressure-sensitive adhesive sheet of the present invention". In the present specification, the base material, the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive composition constituting the optical pressure-sensitive adhesive sheet of the present invention are respectively referred to as "the base material of the present invention", "the pressure-sensitive adhesive layer of the present invention", and may be referred to as "the adhesive composition of the present invention". In addition, the antistatic agent contained in the pressure-sensitive adhesive composition of the present invention, the "ionic compound having a functional group capable of forming a covalent bond with the acrylic polymer (A) in the molecule", is referred to as the "antistatic agent of the present invention". Alternatively, it may be referred to as "the ionic compound of the present invention".

Further, the optical layered body of the third aspect of the present invention is an optical layered body obtained by laminating the optical pressure-sensitive adhesive sheet of the present invention and an optical member. The optical layered body of the third aspect of the present invention may be referred to as "the optical layered body of the present invention" in this specification.
Furthermore, the image display device of the fourth aspect of the present invention is an image display device in which the optical pressure-sensitive adhesive sheet of the present invention and an image display panel are laminated. The image display device according to the fourth aspect of the present invention may be referred to as "the image display device of the present invention" in this specification.

Hereinafter, embodiments of the optical pressure-sensitive adhesive sheet of the present invention will be described with reference to the drawings, but the present invention is not limited thereto and is merely an example.

FIG. 1 is a schematic diagram (cross-sectional view) showing one embodiment of the optical pressure-sensitive adhesive sheet of the present invention.
In FIG. 1, an optical pressure-sensitive adhesive sheet 10 has a laminated structure in which a substrate 1 and a pressure-sensitive adhesive layer 2 are laminated. The substrate 1 has a first surface 1a and a second surface 1b, and an adhesive layer 2 is laminated on the first surface 1a of the substrate 1. As shown in FIG. The second surface 1b of the substrate 1 is subjected to antireflection treatment, antiglare treatment, hard coat treatment, and/or antistatic treatment 3. FIG. The surface (adhesive surface) of the adhesive layer 2 that is not laminated on the first surface 1 a of the substrate 1 is protected by the separator 4 .

FIG. 2 is a schematic diagram (cross-sectional view) showing one embodiment of the optical laminate of the present invention.
In FIG. 2, the optical laminate 20 has a laminate structure in which a substrate 1, an adhesive layer 2, and an optical member 5 are laminated in this order. The substrate 1 has a first surface 1a and a second surface 1b, and the pressure-sensitive adhesive layer 2 is laminated on the first surface 1a of the substrate 1 . The optical member 5 is laminated on the surface of the pressure-sensitive adhesive layer 2 that is not laminated on the first surface 1a of the substrate 1 . The second surface 1b of the substrate 1 is subjected to antireflection treatment, antiglare treatment, hard coat treatment, and/or antistatic treatment 3. FIG.

FIG. 3 is a schematic diagram (sectional view) showing one embodiment of the image display device of the present invention. In FIG. 3, the image display device 30 has an image display panel 6 laminated on the adhesive layer 2 of the optical adhesive sheet 10 .
Each configuration will be described below.

[1. Optical adhesive sheet]
The “optical” in the optical pressure-sensitive adhesive sheet of the present invention means that it is used for optical purposes, and more specifically means that it is used for manufacturing products (optical products) using optical members. do. Examples of optical products include image display devices, input devices such as touch panels, and liquid crystal image display devices, self-luminous image display devices (eg, organic EL (electroluminescence) image display devices, LED image display devices, etc.). ) and the like.

The form of the optical pressure-sensitive adhesive sheet of the present invention is not particularly limited as long as the pressure-sensitive adhesive layer of the present invention is laminated on the first surface of the substrate of the present invention. For example, it may be a single-sided PSA sheet having an adhesive surface on only one side, or a double-sided PSA sheet having an adhesive surface on both sides. When the optical pressure-sensitive adhesive sheet of the present invention is a double-sided pressure-sensitive adhesive sheet, the optical pressure-sensitive adhesive sheet of the present invention may have a form in which both pressure-sensitive adhesive surfaces are provided by the pressure-sensitive adhesive layer of the present invention. , one pressure-sensitive adhesive surface is provided by the pressure-sensitive adhesive layer of the present invention, and the other pressure-sensitive adhesive surface is provided by a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer of the present invention (other pressure-sensitive adhesive layer). good. When the optical pressure-sensitive adhesive sheet of the present invention constitutes the outermost surface of an optical product, a single-sided pressure-sensitive adhesive sheet is preferable, and when adherends (optical members) are bonded together, a double-sided pressure-sensitive adhesive sheet is preferable. In addition, the meaning of an "adhesive tape" shall be included in an "adhesive sheet." That is, the optical pressure-sensitive adhesive sheet of the present invention may be a pressure-sensitive adhesive tape having a tape-like shape. Moreover, in this specification, the adhesive layer surface may be called an "adhesive surface."

[1-1. Various Physical Properties of Optical Adhesive Sheets]
180° peeling strength of the optical pressure-sensitive adhesive sheet of the present invention to a glass plate at 23°C 180° peeling adhesive force at 23°C to a glass plate) is not particularly limited, but from the viewpoint that sufficient adhesion can be obtained if the adhesive force is high, it is preferably 4 N / 20 mm or more, more preferably. is 6 N/20 mm or more, more preferably 8 N/20 mm or more, still more preferably 10 N/20 mm or more. If the optical pressure-sensitive adhesive sheet of the present invention has a 180° peeling adhesive strength to a glass plate at 23°C of a certain value or more, the adhesiveness to glass and the ability to prevent floating on steps are further improved. The upper limit of the 180° peeling adhesive strength of the optical pressure-sensitive adhesive sheet of the present invention to a glass plate at 23°C is not particularly limited, but is preferably, for example, 28 N/20 mm, 27 N/20 mm, or 26 N/20 mm. Preferably, they are 25N/20mm, 24N/20mm, 23N/20mm, 22N/20mm, 21N/20mm and 20N/20mm.

180° peeling strength of the optical pressure-sensitive adhesive sheet of the present invention to a glass plate at 80°C 180° peeling adhesive force at 80°C to a glass plate) is not particularly limited, but from the viewpoint that sufficient adhesion can be obtained if the adhesive force is high, it is preferably 4 N / 20 mm or more, more preferably. is 6 N/20 mm or more, more preferably 8 N/20 mm or more, still more preferably 10 N/20 mm or more. If the optical pressure-sensitive adhesive sheet of the present invention has a 180° peeling adhesive strength to a glass plate at 80°C of a certain value or more, the adhesiveness to glass and the ability to prevent floating on steps are further improved. Although the upper limit of the 180° peeling adhesive strength at 80°C of the optical pressure-sensitive adhesive sheet of the present invention to a glass plate is not particularly limited, it is preferably 18 N/20 mm, more preferably 16 N/20 mm. The 180° peeling adhesion to a glass plate at 23°C or 80°C is determined by the following method for measuring 180° peeling adhesion.

Although the glass plate is not particularly limited, for example, the product name "Soda Lime Glass #0050" (manufactured by Matsunami Glass Industry Co., Ltd.) can be mentioned. In addition, non-alkali glass, chemically strengthened glass, and the like can also be used.

(A-1. 180° peeling adhesive force measurement method)
The adhesive surface of the optical pressure-sensitive adhesive sheet is adhered to the adherend, pressed with a 2-kg roller for one reciprocation, and aged in an atmosphere of 23° C. and 50% RH for 30 minutes or 240 hours. After aging, according to JIS Z 0237, the optical pressure-sensitive adhesive sheet was peeled off from the adherend under the conditions of 23° C. or 80° C., 50% RH, a tensile speed of 300 mm/min, and a peeling angle of 180°, Measure the 180° peel adhesion (N/20 mm).

(B. Thickness)
The thickness (total thickness) of the adhesive sheet of the present invention is not particularly limited, but is preferably 12 to 350 μm, more preferably 15 to 330 μm, 18 to 325 μm, 18 to 320 μm, 20 to 300 μm, 23 to 300 μm, 25 to 275 μm. , or from 30 to 250 μm. When the thickness is equal to or greater than a certain value, peeling at the step portion is less likely to occur, which is preferable. Further, when the thickness is less than a certain value, it is preferable because it becomes easy to maintain an excellent appearance during production. In the case of a pressure-sensitive adhesive sheet with a substrate, the thickness of the pressure-sensitive adhesive sheet of the present invention includes the thickness of the substrate, but does not include the thickness of the separator.

(C. Hayes)
The haze (according to JIS K7136) of the optical pressure-sensitive adhesive sheet of the present invention is not particularly limited, but is preferably 1.0% or less, more preferably 0.8% or less, 0.7% or less, or 0.6%. It may be below. A haze of 1.0% or less is preferable because excellent transparency and appearance can be obtained. Incidentally, the above-mentioned haze can be measured, for example, by leaving the optical pressure-sensitive adhesive sheet in a normal state (23° C., 50% RH) for at least 24 hours, peeling off the separator, if any, and adjusting the haze on a slide glass (e.g., total light transmission). haze of 92% and haze of 0.2%) can be used as a sample and measured using a haze meter (manufactured by Murakami Color Research Laboratory Co., Ltd., trade name "HM-150N").

(D. Total light transmittance)
The total light transmittance (according to JIS K7361-1) in the visible light wavelength region of the optical pressure-sensitive adhesive sheet of the present invention is not particularly limited, but is preferably 90% or more, more preferably 91% or more, or 92% or more. There may be. When the total light transmittance is 90% or more, excellent transparency and excellent appearance can be obtained, which is preferable. The above total light transmittance can be measured, for example, by allowing the optical pressure-sensitive adhesive sheet to stand in a normal state (23° C., 50% RH) for at least 24 hours, peeling off the separator if it has one, and using a slide glass (for example, Total light transmittance of 92%, haze of 0.2%) is used as a sample, and measured using a haze meter (manufactured by Murakami Color Research Laboratory, trade name "HM-150N"). can be done.

The adhesive strength, total light transmittance and haze of the optical pressure-sensitive adhesive sheet of the present invention can be measured by the methods described in Examples below. The adhesive strength, total light transmittance and haze of the optical pressure-sensitive adhesive sheet of the present invention are determined by the composition of the monomers constituting the acrylic polymer (A), the amount of the cross-linking agent, the ionic compound of the present invention, the type of other additives, and the Adjustments can be made by adjusting amounts, curing conditions, and the like.

<Base material>
Materials constituting the substrate of the present invention include glass and plastic films. Examples of the plastic film include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); name "Zeonor" (manufactured by Zeon Co., Ltd.), acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate, triacetyl cellulose (TAC), polysulfone, polyarylate, polyimide, transparent polyimide (CPI), poly Examples thereof include plastic materials such as vinyl chloride, polyvinyl acetate, polyethylene, polypropylene, and ethylene-propylene copolymers. Preferred are polyester-based resins and cyclic olefin-based polymers (COP), which are excellent in dimensional stability and resistant to shrinkage. In addition, these plastic materials can be used individually or in combination of 2 or more types. The substrate of the present invention is a portion that is attached to an adherend together with the adhesive layer when the optical pressure-sensitive adhesive sheet of the present invention is attached to an adherend (optical member, image display panel, etc.). The "base material" does not include a separator (release liner) that is peeled off when the optical pressure-sensitive adhesive sheet of the present invention is used (attached).

The substrate of the present invention has a film-like (substrate-like) form having a first surface and a second surface. The base material of the present invention is not particularly limited as long as it is an optical member constituting the optical product, and includes various optical films such as cover members, polarizing plates, and retardation plates, and is preferably used as a cover member. When the substrate of the present invention is a cover member, the second surface is, for example, the outermost surface of the optical product.

Although the glass transition point (Tg) of the base material of the present invention is not particularly limited, it is preferably 60°C or higher and 160°C or lower. A configuration in which the glass transition point of the substrate of the present invention is 60° C. or higher is preferable in terms of stabilizing the mechanical properties of the image display device of the present invention under the usage environment. From the viewpoint of the stability of the mechanical properties of the image display device of the present invention, the glass transition point of the substrate may be 63° C. or higher, or 65° C. or higher. Moreover, the configuration in which the glass transition point of the substrate is 160° C. or lower is preferable in that the molding process of the substrate can be simplified. The glass transition point of the substrate is preferably 140° C. or lower, and may be 135° C. or lower, 130° C. or lower, or 125° C. or lower in terms of simplifying the molding process of the substrate.

The glass transition point (Tg) of the base material of the present invention can be measured according to JIS K 7121. The glass transition point (Tg) of the base material of the present invention can be adjusted by the type of resin constituting the base material of the present invention.

The humidity expansion coefficient of the base material of the present invention is not particularly limited, but is preferably 5×10 ⁻⁵ /% RH or less. The configuration in which the humidity expansion coefficient of the substrate of the present invention is 5×10 ⁻⁵ /% RH or less is preferable in terms of improving the dimensional stability of the substrate of the present invention against temperature changes and maintaining a good appearance. is. From the viewpoint of dimensional stability of the base material of the present invention, the humidity expansion coefficient of the base material of the present invention is preferably 3×10 ⁻⁵ /% RH or less, and may be 2×10 ⁻⁵ /% RH or less.

Specifically, the coefficient of humidity expansion of the base material of the present invention can be measured by the method described in Examples below. The humidity expansion coefficient of the base material of the present invention can be adjusted by the type of resin constituting the base material of the present invention, the conditions (temperature, extrusion speed, etc.) during the production of the base material, and the like.

Although the haze of the base material of the present invention is not particularly limited, it is preferably 5% or more. The configuration in which the haze of the base material of the present invention is 5% or more is preferable in that reflection due to metal wiring, ITO wiring, or the like arranged on the substrate of the image display panel in the image display device of the present invention can be prevented. It is preferably 6% or more, and may be 7% or more. The upper limit of the haze of the base material of the present invention is not particularly limited, but from the viewpoint of visibility of the image display device of the present invention, it is preferably 50% or less, and may be 40% or less or 30% or less.

The haze of the base material of the present invention can be measured according to JIS K 7136. The haze of the substrate of the present invention can be adjusted by the type and thickness of the resin that constitutes the substrate of the present invention, and by subjecting the surface of the substrate to antireflection treatment and/or antiglare treatment.

Although the reflectance of the substrate of the present invention is not particularly limited, it is preferably 5% or less. The configuration in which the reflectance of the base material of the present invention is 5% or less is preferable in that reflection due to metal wiring, ITO wiring, or the like arranged on the substrate of the image display panel in the image display device of the present invention can be prevented. It is more preferably 3% or less, and may be 1.5% or less. The lower limit of the reflectance of the substrate of the present invention is not particularly limited, but may be 0.1% or more, or 0.3% or more.

The reflectance of the substrate of the present invention can be measured according to JIS K7361-1. The reflectance of the base material of the present invention can be adjusted by the type and thickness of the resin constituting the base material of the present invention, and by subjecting the surface of the base material to antireflection treatment and/or antiglare treatment.

Although the thickness of the substrate of the present invention is not particularly limited, it is preferably in the range of 10 to 500 μm, more preferably in the range of 10 to 500 μm, considering dimensional stability, strength, workability such as handleability, thin layer property, and the like. It ranges from 20 to 300 μm, more preferably from 25 to 250 μm, optimally from 30 to 200 μm. The refractive index of the substrate of the present invention is not particularly limited, but is, for example, in the range of 1.30 to 1.80, preferably in the range of 1.40 to 1.70.

The second surface of the substrate of the present invention is preferably subjected to reflective surface treatment and/or antiglare treatment. The configuration in which the second surface of the base material of the present invention is subjected to reflective surface treatment and / or anti-glare treatment prevents deterioration of visibility due to reflection of external light and reflection of images, etc. This is preferable from the viewpoint of adjusting appearance. It is also preferable in that it can prevent reflection due to metal wiring, ITO wiring, and the like arranged on the substrate of the image display device of the present invention. Moreover, it is preferable that the second surface of the substrate of the present invention is subjected to a hard coat treatment. The configuration in which the second surface of the substrate of the present invention is hard-coated is preferable in that the surface hardness and scratch resistance are improved.

As the antireflection treatment, any known antireflection treatment can be used without particular limitation, and examples thereof include antireflection (AR) treatment.

As the antireflection (AR) treatment, a known AR treatment can be applied without particular limitation. It can be carried out by forming an antireflection layer (AR layer) in which two or more layers of thin films or optical thin films are laminated. The AR layer exerts an antireflection function by canceling out the reversed phases of the incident light and the reflected light using the interference effect of light. The wavelength region of visible light that exhibits the antireflection function is, for example, 380 to 780 nm, and the wavelength region with particularly high luminosity is in the range of 450 to 650 nm. It is preferable to design the AR layer so that

The AR layer generally includes a multilayer antireflection layer having a structure in which two to five optical thin layers (thin films with strictly controlled thickness and refractive index) are laminated. By forming multiple layers with a thickness of , the degree of freedom in the optical design of the AR layer increases, the anti-reflection effect can be further improved, and the spectral reflection characteristics can be made uniform (flat) in the visible light region. become. Since the optical thin film requires high thickness accuracy, each layer is generally formed by dry methods such as vacuum deposition, sputtering, and CVD.

In addition, the AR layer can also be formed using a coating solution for forming an antireflection layer. The antireflection layer-forming coating liquid may contain, for example, a resin, a fluorine element-containing additive, hollow particles, solid particles, a diluent solvent, and the like, and can be produced, for example, by mixing these.

Examples of the resin include thermosetting resins and ionizing radiation curable resins that are cured by ultraviolet light or light. As the resin, it is possible to use a commercially available thermosetting resin, ultraviolet curable resin, or the like.

As the thermosetting resin or UV-curable resin, for example, a curable compound having at least one of an acrylate group and a methacrylate group that is cured by heat, light (ultraviolet rays, etc.), electron beams, or the like can be used. Silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiolpolyene resins, oligomers or prepolymers such as acrylates and methacrylates of polyfunctional compounds such as polyhydric alcohols. can give. These may be used individually by 1 type, and may use 2 or more types together.

For the resin, for example, a reactive diluent having at least one of an acrylate group and a methacrylate group can be used. As the reactive diluent, for example, reactive diluents described in JP-A-2008-88309 can be used, and examples include monofunctional acrylates, monofunctional methacrylates, polyfunctional acrylates, polyfunctional methacrylates, and the like. As the reactive diluent, tri- or more functional acrylates and tri- or more functional methacrylates are preferable. This is because the hardness of the second surface of the substrate of the present invention can be made excellent. Examples of the reactive diluent include butanediol glycerol ether diacrylate, isocyanuric acid acrylate, and isocyanuric acid methacrylate. These may be used individually by 1 type, and may use 2 or more types together. The weight average molecular weight of the resin before curing may be, for example, 100 or more, 300 or more, 500 or more, 1,000 or more, or 2,000 or more, 100,000 or less, 70,000 or less, 50 ,000 or less, 30,000 or less, or 10,000 or less. If the weight-average molecular weight before curing is high, the hardness tends to be low, but cracking tends to be less likely to occur when bent. On the other hand, when the weight-average molecular weight before curing is low, the intermolecular crosslink density tends to improve and the hardness tends to increase.

The resin preferably contains a polyfunctional acrylate (eg, pentathritol triacrylate).

For example, a curing agent may be added to cure the curable resin. The curing agent is not particularly limited, and for example, a known polymerization initiator (eg, thermal polymerization initiator, photopolymerization initiator, etc.) can be used as appropriate. The amount of the curing agent to be added is not particularly limited. 15 parts by weight or more, 13 parts by weight or less, 10 parts by weight or less, 7 parts by weight or less, or 5 parts by weight or less; There may be.

The fluorine element-containing additive is not particularly limited, but may be, for example, an organic compound or an inorganic compound containing fluorine in the molecule. Examples of the organic compound include, but are not limited to, fluorine-containing antifouling coating agents, fluorine-containing acrylic compounds, fluorine- and silicon-containing acrylic compounds, and the like. Specific examples of the organic compound include "KY-1203" (trade name) manufactured by Shin-Etsu Chemical Co., Ltd., "Megafac" (trade name) manufactured by DIC Corporation, and the like. The inorganic compound is also not particularly limited. The amount of the elemental fluorine-containing additive to be added is not particularly limited. 0.05% by weight or more, 0.1% by weight or more, 0.15% by weight or more, 0.20% by weight or more, or 0.25% by weight or more, and 20% by weight or less, 15% by weight or less , 10 wt % or less, 5 wt % or less, or 3 wt % or less. Further, for example, the weight of the fluorine element-containing additive with respect to 100 parts by weight of the resin in the antireflection layer-forming coating liquid is, for example, 0.05 wt% or more, 0.1 wt% or more, 0 .15 wt% or more, 0.20 wt% or more, or 0.25 wt% or more, and 20 wt% or less, 15 wt% or less, 10 wt% or less, 5 wt% or less, or 3 wt% It may be below.

The hollow particles are not particularly limited, but may be, for example, silica particles, acrylic particles, acrylic-styrene copolymer particles, or the like. Examples of the silica particles include trade names "Sururia 5320" and "Sururia 4320" manufactured by Nikki Shokubai & Chemicals Co., Ltd. The weight average particle diameter of the hollow particles is not particularly limited, but may be, for example, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, or 70 nm or more, 150 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, Alternatively, it may be 110 nm or less. The shape of the hollow particles is not particularly limited, and may be, for example, a substantially spherical shape such as a bead, or an irregular shape such as a powder. They are substantially spherical particles with an aspect ratio of 1.5 or less, most preferably spherical particles. By adding the hollow particles, for example, a low refractive index, good antireflection properties, etc. of the antireflection layer can be realized. The amount of the hollow particles to be added is not particularly limited. parts by weight or more, or 100 parts by weight or more, and may be 300 parts by weight or less, 270 parts by weight or less, 250 parts by weight or less, 200 parts by weight or less, or 180 parts by weight or less. From the viewpoint of lowering the refractive index of the antireflection layer, the amount of the hollow particles added is preferably not too small, and from the viewpoint of ensuring the mechanical properties of the antireflection layer, the amount of the hollow particles added should not be too large. is preferred.

The solid particles are not particularly limited, but may be, for example, silica particles, zirconium oxide particles, titanium-containing particles (eg, titanium oxide particles), and the like. Examples of the silica particles include trade names "MEK-2140Z-AC", "MIBK-ST", and "IPA-ST" manufactured by Nissan Chemical Industries, Ltd. The weight average particle diameter of the solid particles is not particularly limited, but may be, for example, 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, or 25 nm or more, and 3300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less. , or 100 nm or less. The shape of the solid particles is not particularly limited, and may be, for example, a substantially spherical bead shape, or an irregular shape such as a powder. , an aspect ratio of 1.5 or less, most preferably spherical particles. By adding the solid particles, for example, the fluorine element-containing additive tends to be unevenly distributed on the surface of the coated antireflection layer-forming coating liquid, and the antireflection layer has excellent scratch resistance, A low refractive index, good antireflection properties, and the like can be realized. The amount of the solid particles to be added is not particularly limited. It may be 150 parts by weight or less, 120 parts by weight or less, 100 parts by weight or less, or 80 parts by weight or less.

The diluent solvent may be, for example, a mixed solvent containing MIBK (methyl isobutyl ketone) and PMA (propylene glycol monomethyl ether acetate). The mixing ratio in this case is not particularly limited. It may be 200 wt% or more, 400 wt% or less, 350 wt% or less, 300 wt% or less, or 250 wt% or less.

The diluent solvent may be, for example, a mixed solvent containing TBA (tertiary butyl alcohol) in addition to MIBK and PMA. The mixing ratio in this case is not particularly limited. It may be 100% by weight or more, 200% by weight or less, 180% by weight or less, 150% by weight or less, 130% by weight or less, or 110% by weight or less. Further, when the weight of MIBK is 100% by weight, the weight of TBA may be, for example, 10% by weight or more, 30% by weight or more, 50% by weight or more, 80% by weight or more, or 100% by weight or more. , 200 wt.% or less, 180 wt.% or less, 150 wt.% or less, 130 wt.% or less, or 110 wt.% or less.

The amount of the diluent solvent to be added is not particularly limited, either. 5 wt% or more, 1.0 wt% or more, or 1.5 wt% or more, and 20 wt% or less, 15 wt% or less, 10 wt% or less, 5 wt% or less, or 3 wt% % or less. From the viewpoint of ensuring coatability (wetness, leveling), it is preferable that the content of the solid content is not too high. is not too low.

Next, the antireflection layer-forming coating liquid is applied onto the second surface of the substrate of the present invention (the coating step). The coating method is not particularly limited, and for example, known coating methods such as fountain coating, die coating, spin coating, spray coating, gravure coating, roll coating, and bar coating can be used as appropriate. can. Although the coating amount of the antireflection layer-forming coating solution is not particularly limited, the thickness of the antireflection layer to be formed is, for example, 0.1 μm or more, 0.3 μm or more, 0.5 μm or more, or 1.0 μm. or 2.0 μm or more, or 50 μm or less, 40 μm or less, 30 μm or less, 20 μm or less, or 10 μm or less.

Next, the coated antireflection layer forming coating solution is dried to form a coating film (the coating film forming step). Although the drying temperature is not particularly limited, it may be in the range of 30 to 200°C, for example. The drying temperature may be, for example, 40° C. or higher, 50° C. or higher, 60° C. or higher, 70° C. or higher, 80° C. or higher, 90° C. or higher, or 100° C. or higher, 190° C. or lower, 180° C. or lower, 170° C. °C or lower, 160 °C or lower, 150 °C or lower, 140 °C or lower, 135 °C or lower, 130 °C or lower, 120 °C or lower, or 110 °C or lower. The drying time is not particularly limited, but may be, for example, 30 seconds or longer, 40 seconds or longer, 50 seconds or longer, or 60 seconds or longer, and may be 150 seconds or shorter, 130 seconds or shorter, 110 seconds or shorter, or 90 seconds or shorter. may

Furthermore, the coating film may be cured (curing step). The curing can be performed, for example, by heating, light irradiation, or the like. Although the light is not particularly limited, it may be, for example, ultraviolet light. The light source for the light irradiation is also not particularly limited, and may be, for example, a high-pressure mercury lamp. The irradiation amount of the energy beam source in the ultraviolet curing is preferably 50 to 500 mJ/cm ² as an integrated exposure amount at an ultraviolet wavelength of 365 nm. When the irradiation dose is 50 mJ/cm ² or more, curing proceeds sufficiently and the hardness of the formed antireflection layer tends to increase. Also, if it is 500 mJ/cm ² or less, coloring of the formed antireflection layer can be prevented.

As the anti-glare (AG) treatment, a known AG treatment can be applied without particular limitation, and can be carried out, for example, by forming an anti-glare layer on the second surface of the base material of the present invention. As the anti-glare layer, known layers can be employed without limitation, and it is generally formed as a layer in which inorganic or organic particles are dispersed as an anti-glare agent in a resin. Also, the antiglare layer may be an antiglare hard coat layer.

The anti-glare layer is not particularly limited. A convex portion is formed on the surface of the . With this configuration, the anti-glare layer has excellent display characteristics that achieve both anti-glare properties and prevention of white blurring, and despite the fact that the anti-glare layer is formed using aggregation of particles, there are no defects in appearance. It is possible to prevent the occurrence of protrusions on the surface of the anti-glare layer and improve the yield of products.

For the resin, for example, a reactive diluent having at least one of an acrylate group and a methacrylate group can be used. As the reactive diluent, for example, reactive diluents described in JP-A-2008-88309 can be used, and examples include monofunctional acrylates, monofunctional methacrylates, polyfunctional acrylates, polyfunctional methacrylates, and the like. As the reactive diluent, tri- or more functional acrylates and tri- or more functional methacrylates are preferable. This is because the hardness of the antiglare layer can be made excellent. Examples of the reactive diluent include butanediol glycerol ether diacrylate, isocyanuric acid acrylate, and isocyanuric acid methacrylate. These may be used individually by 1 type, and may use 2 or more types together.

The resin preferably contains a urethane acrylate resin, more preferably a copolymer of a curable urethane acrylate resin and a polyfunctional acrylate (for example, pentathritol triacrylate).

The main functions of the particles for forming the anti-glare layer are to make the surface of the formed anti-glare layer uneven to impart anti-glare properties, and to control the haze value of the anti-glare layer. The haze value of the antiglare layer can be designed by controlling the refractive index difference between the particles and the resin. Examples of the particles include inorganic particles and organic particles. The inorganic particles are not particularly limited, and examples include silicon oxide particles, titanium oxide particles, aluminum oxide particles, zinc oxide particles, tin oxide particles, zirconium oxide particles, calcium carbonate particles, barium sulfate particles, talc particles, kaolin particles, Examples include calcium sulfate particles. The organic particles are not particularly limited, and examples include polymethyl methacrylate resin powder (PMMA fine particles), silicone resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin. Examples thereof include resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, polyethylene fluoride resin powder, and the like. One type of these inorganic particles and organic particles may be used alone, or two or more types may be used in combination.

The weight average particle size (D) of the particles is preferably within the range of 2.5 to 10 μm. By setting the weight-average particle size of the particles within the above range, for example, the anti-glare property is more excellent and white blurring can be prevented. The weight average particle size of the particles is more preferably in the range of 3-7 μm. The weight-average particle diameter of the particles can be measured, for example, by the Coulter counting method. For example, using a particle size distribution measuring device (trade name: Coulter Multisizer, manufactured by Beckman Coulter, Inc.) using the pore electrical resistance method, the volume of the electrolyte solution corresponding to the volume of the particles when the particles pass through the pores. By measuring the electrical resistance, the number and volume of the particles are measured, and the weight average particle diameter is calculated.

The shape of the particles is not particularly limited, and may be, for example, a substantially spherical bead shape, or an irregular shape such as a powder. They are substantially spherical particles with a ratio of 1.5 or less, most preferably spherical particles.

The proportion of the particles in the antiglare layer is preferably in the range of 0.2 to 12 parts by weight, more preferably in the range of 0.5 to 12 parts by weight, still more preferably 1 part by weight, relative to 100 parts by weight of the resin. ~7 parts by weight. By setting it within the above range, for example, it is possible to achieve more excellent anti-glare properties and prevent white blurring.

The antiglare layer may contain a thixotropy-imparting agent. By containing the thixotropy-imparting agent, the aggregation state of the particles can be easily controlled. Examples of the thixotropy-imparting agent for forming the antiglare layer include organic clay, polyolefin oxide, and modified urea.

The organoclay is preferably an organically treated clay in order to improve the affinity with the resin. Examples of organic clays include layered organic clays. The organic clay may be self-prepared, or a commercially available product may be used. Examples of the commercially available products include Lucentite SAN, Lucentite STN, Lucentite SEN, Lucentite SPN, Somasif ME-100, Somasif MAE, Somasif MTE, Somasif MEE, Somasif MPE (trade names, all of which are manufactured by Co-op Chemical Co., Ltd.). ) manufactured); Organite, Organite D, Organite T (trade names, all manufactured by Hojun Co., Ltd.); Kunipia F, Kunipia G, Kunipia G4 (trade names, manufactured by Kunimine Industry Co., Ltd.); Thixogel VZ, Kraton HT , Clayton 40 (trade name, both manufactured by Rockwood Additives), and the like.

The oxidized polyolefin may be prepared in-house, or a commercially available product may be used. Examples of the commercially available products include Disparlon 4200-20 (trade name, manufactured by Kusumoto Kasei Co., Ltd.) and Flownon SA300 (trade name, manufactured by Kyoeisha Chemical Co., Ltd.).

The modified urea is a reaction product of an isocyanate monomer or its adduct and an organic amine. The modified urea may be self-prepared, or a commercially available product may be used. Examples of the commercial product include BYK410 (manufactured by Big Chemie).

The thixotropy-imparting agents may be used singly or in combination of two or more.

The height of the convex portion from the roughness average line of the antiglare layer is preferably less than 0.4 times the thickness of the antiglare layer. More preferably, it is in the range of 0.01 times or more and less than 0.4 times, and still more preferably in the range of 0.01 times or more and less than 0.3 times. Within this range, it is possible to suitably prevent the formation of projections that impair the appearance of the convex portion. Since the antiglare layer has convex portions with such heights, it is possible to make appearance defects less likely to occur. Here, the height from the average line can be measured, for example, by the method described in JP-A-2017-138620.

The proportion of the thixotropy imparting agent in the antiglare layer is preferably in the range of 0.1 to 5 parts by weight, more preferably in the range of 0.2 to 4 parts by weight, with respect to 100 parts by weight of the resin.

Although the thickness (d) of the antiglare layer is not particularly limited, it is preferably in the range of 3 to 12 μm. By setting the thickness (d) of the antiglare layer within the above range, for example, the optical pressure-sensitive adhesive sheet of the present invention can be prevented from curling, and the problem of reduced productivity such as poor transportability can be avoided. Further, when the thickness (d) is within the above range, the weight average particle size (D) of the particles is preferably within the range of 2.5 to 10 μm as described above. When the thickness (d) of the anti-glare layer and the weight average particle size (D) of the particles are in the above-described combination, the anti-glare property can be further improved. The thickness (d) of the antiglare layer is more preferably in the range of 3-8 μm.

The relationship between the thickness (d) of the antiglare layer and the weight average particle diameter (D) of the particles is preferably within the range of 0.3≦D/d≦0.9. By having such a relationship, it is possible to obtain an anti-glare layer that is more excellent in anti-glare properties, can prevent white blurring, and has no defects in appearance.

In the optical pressure-sensitive adhesive sheet of the present invention, as described above, the anti-glare layer forms convex portions on the surface of the anti-glare layer due to aggregation of the particles and the thixotropy-imparting agent. In the aggregated portion forming the convex portion, the particles are present in a state in which a plurality of the particles are aggregated in the surface direction of the antiglare layer. As a result, the convex portion has a gentle shape. Since the anti-glare layer has convex portions having such a shape, it is possible to maintain the anti-glare property, prevent white blurring, and make appearance defects less likely to occur.

The surface shape of the antiglare layer can be arbitrarily designed by controlling the aggregation state of the particles contained in the antiglare layer forming material. The aggregation state of the particles can be controlled by, for example, the material of the particles (for example, chemically modified state of the particle surface, affinity for solvent or resin, etc.), type of resin (binder) or solvent, combination, and the like. Here, the aggregation state of the particles can be controlled by the thixotropy imparting agent contained in the antiglare layer-forming material. As a result, the aggregated state of the particles can be made as described above, and the convex portion can be formed into a smooth shape.

In the optical pressure-sensitive adhesive sheet of the present invention, when the substrate of the present invention is made of a resin or the like, it preferably has a permeation layer at the interface between the substrate of the present invention and the antiglare layer. The permeation layer is formed by permeating the resin component contained in the material for forming the antiglare layer into the substrate of the present invention. The formation of the permeation layer is preferable because the adhesion between the substrate of the present invention and the antiglare layer can be improved. The penetration layer preferably has a thickness in the range of 0.2 to 3 μm, more preferably in the range of 0.5 to 2 μm. For example, when the base material of the present invention is a polyester-based resin and the resin contained in the antiglare layer is an acrylic resin, the permeation layer can be formed. The penetration layer can be confirmed and the thickness can be measured, for example, by observing the cross section of the optical pressure-sensitive adhesive sheet of the present invention with a transmission electron microscope (TEM).

Even when applied to the optical pressure-sensitive adhesive sheet of the present invention having such a permeation layer, it is possible to easily form a desired smooth uneven surface shape that achieves both anti-glare properties and prevention of white blurring. . It is preferable that the permeation layer is formed thicker in order to improve the adhesion of the base material with poor adhesion to the anti-glare layer.

In the antiglare layer, it is preferable that the number of appearance defects having a maximum diameter of 200 μm or more is 1 or less per 1 m ² of the antiglare layer. More preferably, it does not have the appearance defect.

In the uneven shape of the surface of the antiglare layer, the average inclination angle θa (°) is . It is preferably in the range of 1 to 5.0, more preferably in the range of 0.3 to 4.5, even more preferably in the range of 1.0 to 4.0, and 1.6 to 4.0. .0 is particularly preferred. Here, the average tilt angle θa is a value defined by the following formula (1). The average tilt angle θa is, for example, a value measured by the method described in JP-A-2017-138620.
Average tilt angle θa=tan-1Δa (1)

In the above formula (1), Δa is, as shown in the following formula (2), in the reference length L of the roughness curve defined in JIS B 0601 (1994 edition), the distance between the top and the valley of the adjacent peaks It is a value obtained by dividing the sum (h1+h2+h3 . The roughness curve is a curve obtained by removing surface waviness components longer than a predetermined wavelength from the cross-sectional curve with a phase difference compensation type high-pass filter. Further, the cross-sectional curve is a contour that appears at the cut end when the target plane is cut along a plane perpendicular to the target plane.
Δa=(h1+h2+h3...+hn)/L (2)

When θa is within the above range, the anti-glare property is more excellent and white blurring can be prevented.

In forming the antiglare layer, the prepared antiglare layer forming material (coating solution) preferably exhibits thixotropy, and the Ti value defined below is in the range of 1.3 to 3.5. is preferred, and more preferably in the range of 1.3 to 2.8.
Ti value = β1/β2
Here, β1 is the viscosity measured at a shear rate of 20 (1/s) using HAAKE's Rheostress 6000, and β2 is the viscosity measured using HAAKE's Rheostress 6000 at a shear rate of 200 (1/s). Viscosity measured under conditions.

If the Ti value is less than 1.3, defects in appearance are likely to occur, and anti-glare properties and white blur characteristics deteriorate. On the other hand, when the Ti value exceeds 3.5, the particles are less likely to agglomerate and more likely to be in a dispersed state.

The method for producing the anti-glare layer is not particularly limited, and it may be produced by any method. Then, the anti-glare layer-forming material (coating liquid) is applied to the second surface of the substrate of the present invention to form a coating film, and the coating film is cured to form an anti-glare layer. . A transfer method using a mold, a method of imparting an uneven shape by an appropriate method such as sandblasting, embossing roll, or the like can also be used together.

The solvent is not particularly limited, and various solvents can be used. One type may be used alone, or two or more types may be used in combination. There is an optimum solvent type and solvent ratio depending on the composition of the resin, the types and contents of the particles and the thixotropy-imparting agent, and the like. Examples of solvents include, but are not limited to, alcohols such as methanol, ethanol, isopropyl alcohol, butanol, and 2-methoxyethanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclopentanone; methyl acetate, ethyl acetate. , Esters such as butyl acetate; Ethers such as diisopropyl ether and propylene glycol monomethyl ether; Glycols such as ethylene glycol and propylene glycol; Cellosolves such as ethyl cellosolve and butyl cellosolve; Aliphatic hydrocarbons such as hexane, heptane and octane Aromatic hydrocarbons such as benzene, toluene, and xylene.

For example, when a polyester-based resin is used as the base material of the present invention to form the permeation layer, a good solvent for the polyester-based resin can be suitably used. Examples of the solvent include ethyl acetate, methyl ethyl ketone, cyclopentanone and the like.

By appropriately selecting the solvent, the thixotropy of the antiglare layer-forming material (coating liquid) by the thixotropy-imparting agent can be satisfactorily expressed. For example, when organoclays are used, toluene and xylene can be suitably used alone or in combination. They can be used or used in combination. For example, when modified urea is used, butyl acetate and methyl isobutyl ketone can be preferably used alone or in combination.

Various leveling agents can be added to the antiglare layer-forming material. As the leveling agent, for example, a fluorine-based or silicone-based leveling agent can be used for the purpose of preventing coating unevenness (uniformizing the coated surface). If antifouling properties are required on the surface of the antiglare layer, or if an antireflection layer (low refractive index layer) or a layer containing an interlayer filler is formed on the antiglare layer, a leveling agent is added as appropriate. can be selected. For example, the inclusion of the thixotropy-imparting agent makes it possible to express thixotropic properties in the coating liquid, so that unevenness in coating is less likely to occur. Therefore, for example, it has an advantage that the options for the leveling agent can be expanded.

The amount of the leveling agent compounded is, for example, 5 parts by weight or less, preferably in the range of 0.01 to 5 parts by weight, per 100 parts by weight of the resin.

Pigments, fillers, dispersants, plasticizers, UV absorbers, surfactants, antifouling agents, antioxidants and the like are added to the antiglare layer-forming material as necessary within a range that does not impair the performance. may These additives may be used singly or in combination of two or more.

For the anti-glare layer-forming material, conventionally known photopolymerization initiators, such as those described in JP-A-2008-88309, can be used.

Examples of the method for applying the anti-glare layer-forming material onto the second surface of the substrate of the present invention include a fountain coating method, a die coating method, a spin coating method, a spray coating method, a gravure coating method, a roll coating method, A coating method such as a bar coating method can be used.

The anti-glare layer-forming material is applied to form a coating film on the substrate of the present invention, and the coating film is cured. It is preferable to dry the coating film prior to the curing. The drying may be, for example, natural drying, air drying by blowing air, heat drying, or a combination thereof.

The means for curing the coating film of the anti-glare layer-forming material is not particularly limited, but ultraviolet curing is preferable. The irradiation amount of the energy beam source is preferably 50 to 500 mJ/cm ² as an integrated exposure amount at an ultraviolet wavelength of 365 nm. When the irradiation dose is 50 mJ/cm ² or more, the curing becomes more sufficient, and the hardness of the formed anti-glare layer becomes more sufficient. Also, if it is 500 mJ/cm ² or less, coloring of the formed antiglare layer can be prevented.

As described above, the antiglare layer can be formed on the second surface of the substrate of the present invention. The anti-glare layer may be formed by a manufacturing method other than the method described above. The hardness of the anti-glare layer is preferably 2H or more in terms of pencil hardness, although it is also affected by the thickness of the layer.

The antiglare layer may have a multi-layer structure in which two or more layers are laminated.

The above-described AR layer (low refractive index layer) may be arranged on the antiglare layer. For example, when an optical pressure-sensitive adhesive sheet is attached to an image display device, one factor that reduces the visibility of the image is the reflection of light at the interface between the air and the anti-glare layer. The AR layer reduces the surface reflection. The antiglare layer and the antireflection layer may each have a multi-layer structure in which two or more layers are laminated.

In addition, in order to prevent the adhesion of contaminants and improve the ease of removal of adhered contaminants, an anti-contamination layer formed of a fluorine group-containing silane compound, a fluorine group-containing organic compound, or the like is used as the antireflection layer and the anti-reflection layer. / Or lamination on the anti-glare layer is preferred.

It is preferable to subject at least one of the substrate of the present invention and the antiglare layer to surface treatment. By surface-treating the surface of the base material of the present invention, the adhesion to the anti-glare layer is further improved. Moreover, if the surface of the anti-glare layer is treated, the adhesion to the AR layer is further improved.

In order to prevent the base material of the present invention from curling, the other surface of the antiglare layer may be subjected to solvent treatment. Further, a transparent resin layer may be formed on the other surface of the antiglare layer in order to prevent curling.

The second surface of the base material of the present invention may be subjected to antistatic treatment. The configuration in which the second surface of the base material of the present invention is subjected to electrification treatment suppresses static electricity charging of the optical pressure-sensitive adhesive sheets of the first and second aspects of the present invention. is used in an image display device, it is preferable in that display defects caused by static electricity can be suppressed.

As the hard coat (HC) treatment, a known HC treatment can be applied without particular limitation, and can be carried out, for example, by forming a hard coat layer on the second surface of the substrate of the present invention. . As the hard coat layer, known ones can be employed without limitation. For example, in the above anti-glare layer-forming material, a hard coat layer-forming material containing only a resin without particles and a thixotropy-imparting agent may be used. Except for this, a hard coat layer having no antiglare properties can be formed in the same manner as the above antiglare layer.

As the antistatic treatment, a known antistatic treatment can be used without particular limitation, and can be carried out, for example, by forming an antistatic layer on the second surface of the substrate of the present invention.

As the antistatic layer, any appropriate antistatic layer can be adopted as long as it is a layer capable of exhibiting an antistatic effect, as long as it does not impair the effects of the present invention. Such an antistatic layer is preferably an antistatic layer formed by coating a conductive coating liquid containing a conductive polymer on any suitable substrate layer. Specifically, for example, it is an antistatic layer formed by coating a substrate with a conductive coating liquid containing a conductive polymer. Specific coating methods include a roll coating method, a bar coating method, a gravure coating method, and the like.

Any suitable conductive polymer can be adopted as the conductive polymer as long as it does not impair the effects of the present invention. Examples of such a conductive polymer include a conductive polymer obtained by doping a π-conjugated conductive polymer with a polyanion. Examples of π-conjugated conductive polymers include linear conductive polymers such as polythiophene, polypyrrole, polyaniline, and polyacetylene. Polyanions include polystyrene sulfonic acid, polyisoprene sulfonic acid, polyvinyl sulfonic acid, polyallylsulfonic acid, polyethyl acrylate sulfonic acid, polymethacrylic carboxylic acid, and the like.

The surface resistivity of the antistatic layer is preferably 1.0×10 ⁴ Ω/square to 1.0×10 ⁹ Ω/square at a temperature of 23° C. and a humidity of 50% RH, more preferably 1.0× 10 ⁴ Ω/□ to 5.0×10 ⁸ Ω/□, more preferably 5.0×10 ⁴ Ω/□ to 1.0×10 ⁸ Ω/□, and particularly preferably 1.0×10 Ω/□. 10 ⁵ Ω/□ to 5.0×10 ⁷ Ω/□. If the surface resistivity of the antistatic layer is within the above range, the effects of the present invention are more likely to be exhibited.

As the thickness of the antistatic layer, any appropriate thickness can be adopted according to the purpose as long as the effects of the present invention are not impaired. Such a thickness is preferably 1 nm to 1000 nm, more preferably 5 nm to 900 nm, even more preferably 7.5 nm to 800 nm, and particularly preferably 10 nm to 700 nm. The antistatic layer may consist of only one layer, or may consist of two or more layers.

The antistatic layer may be provided alone on the second surface of the substrate of the present invention, or an antiglare layer and/or an AR layer may be provided on the antistatic layer. Alternatively, as a topcoat layer, an antistatic layer may be provided on the antiglare layer and/or the AR layer.

[2. Adhesive composition and adhesive layer]
The pressure-sensitive adhesive layer of the present invention is a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention.
The pressure-sensitive adhesive composition of the present invention includes an antistatic agent, an acrylic polymer (A), a mixture of monomer components constituting the acrylic polymer (A), or a mixture of monomer components constituting the acrylic polymer (A). and the antistatic agent is an ionic compound having in its molecule a functional group capable of forming a covalent bond with the acrylic polymer (A).

The pressure-sensitive adhesive composition of the present invention may have any form, for example, emulsion type, hot melt type (hot melt type), non-solvent type (active energy ray curable type, e.g., monomer mixture, or monomer mixtures and partially polymerized products thereof) and the like. In particular, the pressure-sensitive adhesive composition of the present invention is preferably non-solvent type. This is because when a pressure-sensitive adhesive layer is to be obtained using a solvent-based pressure-sensitive adhesive composition, defects in appearance such as citrus peel are likely to occur. In addition, "yuzu skin" refers to a phenomenon in which unevenness occurs like the skin of "yuzu", which is a kind of citrus fruit. Moreover, the pressure-sensitive adhesive composition of the present invention is preferably active energy ray-curable from the viewpoint of obtaining a pressure-sensitive adhesive layer with excellent appearance. In this specification, the pressure-sensitive adhesive composition means a composition used for forming the pressure-sensitive adhesive layer, and includes the meaning of the composition used for forming the pressure-sensitive adhesive.

The organic solvent is not particularly limited as long as it is an organic compound used as a solvent. Examples include hydrocarbon solvents such as cyclohexane, hexane, and heptane; aromatic solvents such as toluene and xylene; ethyl acetate, methyl acetate, and the like. ketone solvents such as acetone and methyl ethyl ketone; and alcohol solvents such as methanol, ethanol, butanol and isopropyl alcohol. In addition, the mixed solvent containing 2 or more types of organic solvents may be sufficient as the said organic solvent.

In the pressure-sensitive adhesive composition of the present invention, "substantially contains no organic solvent" means that the organic solvent is not actively blended, except when the organic solvent is unavoidably mixed. Specifically, the content of the organic solvent in the adhesive composition is 1.0% by weight or less (preferably 0.5% by weight or less, more preferably 0.2% by weight or less) can be said to be substantially free.

The base polymer contained in the adhesive composition of the present invention is acrylic polymer (A). That is, the pressure-sensitive adhesive composition of the present invention is an acrylic pressure-sensitive adhesive composition containing an acrylic polymer as a base polymer. Acrylic polymers are preferred because of their transparency, weather resistance, adhesion reliability, and ease of functional design of the pressure-sensitive adhesive layer due to the wide variety of monomers available. In other words, the pressure-sensitive adhesive composition of the present invention is preferably an acrylic pressure-sensitive adhesive composition containing the below-described acrylic polymer (A) as a base polymer. In addition, acrylic polymer (A) can be used individually or in combination of 2 or more types.

The content of the acrylic polymer (A) in the pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) is not particularly limited, but may be 75% by weight or more (for example, 75 to 99.9%). 9% by weight), more preferably 85% by weight or more (for example, 85 to 99.9% by weight).

The adhesive composition of the present invention preferably does not contain or substantially does not contain acidic group-containing monomers (eg, carboxyl group-containing monomers, sulfo group-containing monomers, phosphoric acid group-containing monomers, etc.). This configuration is preferable in that an excellent effect of preventing corrosion of metal wiring can be obtained. 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, based on the total amount of the adhesive composition of the present invention. % or less (eg, 0 to 0.01% by weight), more preferably 0.001% by weight or less (eg, 0 to 0.001% by weight), it can be said to be substantially free.

The pressure-sensitive adhesive composition of the present invention preferably does not contain, or substantially does not contain, an acidic group-containing monomer such as a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer contained as the base polymer. More preferably, the pressure-sensitive adhesive composition of the present invention does not contain or substantially does not contain a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A). Therefore, the pressure-sensitive adhesive composition of the present invention can obtain an excellent anti-corrosion effect. The meaning of the carboxyl group-containing monomer, the meaning of "not containing substantially", the monomer having an acidic group other than the carboxyl group, etc. are the same as in the case of the monomer component constituting the acrylic polymer (A). do. 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, based on the total amount of the pressure-sensitive adhesive composition of the present invention. % or less (eg, 0 to 0.01% by weight), more preferably 0.001% by weight or less (eg, 0 to 0.001% by weight), it can be said to be substantially free.

The adhesive layer of the present invention (the adhesive layer formed from the adhesive composition of the present invention) has excellent antistatic performance. Therefore, display defects due to static electricity can be suppressed when an image display device and an optical member are attached to each other via the pressure-sensitive adhesive layer of the present invention. Thus, the pressure-sensitive adhesive layer of the present invention is suitably used for manufacturing image display devices.

(Surface resistivity)
The surface resistivity (according to JIS K 6271) of the pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) is preferably 1.0× from the viewpoint of excellent antistatic performance. 10 ¹⁰ Ω/□ or less, more preferably 0.5×10 ¹⁰ Ω/□ or less, still more preferably 1.0×10 ⁹ Ω/□ or less, and 0.5×10 ⁹ Ω/□ or less or less, or 1.0×10 ⁸ Ω/□ or less. The lower limit of the surface resistivity of the pressure-sensitive adhesive layer of the present invention is not particularly limited, but may be 1.0×10 ⁵ Ω/□ or more, or 0.5×10 ⁵ Ω/□ or more.

The pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) can suppress the bleed-out of the anticonductive agent and maintain the transparency of the appearance even in a moist and hot environment, and has excellent It can stably impart antistatic performance. For this reason, display defects due to static electricity can be suppressed while maintaining transparency even in a moist and hot environment after bonding the image display device and the optical member via the pressure-sensitive adhesive layer of the present invention. Thus, the pressure-sensitive adhesive layer of the present invention is suitably used for manufacturing image display devices.

The pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) was placed in an environment of 60°C and 95% RH for 240 hours and then taken out, and then placed in an environment of 23°C and 50% RH. After controlling the temperature and humidity for 24 hours, the surface resistivity of the adhesive layer surface after a moist heat test in an atmosphere of 23 ° C and 50% RH suppresses the bleeding out of the anti-conductive agent even in a moist heat environment. 5.0×10 ¹⁰ Ω/□ is preferable from the viewpoint of stably imparting excellent antistatic performance by ensuring the stability of the resistance value before and after the wet heat test while maintaining the transparency of the appearance. or less, more preferably 3.0×10 ¹⁰ Ω/□ or less, still more preferably 1.0×10 ¹⁰ Ω/□ or less, 0.5×10 ¹⁰ Ω/□ or less, 1.0 ×10 ⁹ Ω/□ or less, 0.5 × 10 ⁹ Ω/□ or less, or 1.0 × 10 ⁸ Ω/□ or less. The lower limit of the surface resistivity of the pressure-sensitive adhesive layer of the present invention after the humidification test is not particularly limited, but is 1.0×10 ⁵ Ω/□ or more, or 0.5×10 ⁵ Ω/□ or more. good too.

The ratio of the surface resistivity of the adhesive layer surface before and after the wet heat test (surface resistance value after the wet heat test / surface resistance value before the wet heat test) suppresses the bleeding out of the anti-conductive agent even in the wet heat environment, and the appearance While maintaining the transparency of, by ensuring the stability of the resistance value before and after the wet heat test, from the viewpoint of being able to impart the stability of excellent antistatic performance, preferably 90 or less, more preferably 50 or less. Yes, more preferably 30 or less, 20 or less, or 10 or less.

The surface resistivity of the pressure-sensitive adhesive layer of the present invention and the surface resistivity after the humidification test can be measured by the method described in Examples below. The surface resistivity of the pressure-sensitive adhesive layer of the present invention and the surface resistivity after a humidification test are determined by the monomer composition constituting the acrylic polymer (A), the amount of the cross-linking agent, the ionic compound of the present invention, the type of other additives, and the like. Adjustments can be made by adjusting amounts, curing conditions, and the like.

(Haze, total light transmittance)
The pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) is transparent or has transparency. Therefore, the visibility and appearance through the pressure-sensitive adhesive layer of the present invention are excellent. Thus, the pressure-sensitive adhesive layer of the present invention is suitable for optical applications.

The haze (according to JIS K7136) of the pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) is not particularly limited, but is preferably 1.0% or less, more preferably It may be 0.8% or less, 0.7% or less, or 0.6% or less. A haze of 1.0% or less is preferable because excellent transparency and appearance can be obtained. Incidentally, the haze is, for example, an adhesive layer (thickness: 100 μm), which is allowed to stand in a normal state (23° C., 50% RH) for at least 24 hours, and then slide glass (for example, total light transmittance of 92%, Haze of 0.2%) can be used as a sample and measured using a haze meter (manufactured by Murakami Color Research Laboratory, trade name "HM-150N").

The total light transmittance (according to JIS K7361-1) in the visible light wavelength region of the adhesive layer of the present invention is not particularly limited, but is preferably 90% or more, more preferably 91% or more, or 92% or more. may When the total light transmittance is 90% or more, excellent transparency and excellent appearance can be obtained, which is preferable. In addition, the above total light transmittance is, for example, an adhesive layer (thickness: 100 μm), which is allowed to stand in a normal state (23 ° C., 50% RH) for at least 24 hours, and then peeled off if it has a separator. Then, a slide glass (for example, total light transmittance of 92%, haze of 0.2%) is used as a sample, and a haze meter (manufactured by Murakami Color Research Laboratory, trade name "HM-150N" ) can be measured using

The total light transmittance and haze of the pressure-sensitive adhesive layer of the present invention can be measured by the methods described in Examples below. The total light transmittance and haze of the pressure-sensitive adhesive layer of the present invention are determined by the monomer composition constituting the acrylic polymer (A), the amount of the cross-linking agent, the ionic compound of the present invention, the type and amount of other additives, curing conditions, etc. can be adjusted by adjusting

(Gel fraction)
The gel fraction (proportion of solvent-insoluble components) of the pressure-sensitive adhesive layer of the present invention (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) is not particularly limited, but is preferably 40 to 95%, more preferably 50 to 92%, more preferably 55 to 90%. When the gel fraction is 40% or more, the cohesive force of the pressure-sensitive adhesive layer is improved, causing foaming and peeling at the interface with the adherend in a high-temperature environment, dents during handling, and edges during processing. Contamination of the part is suppressed, and excellent anti-foaming peeling property is easily obtained, which is preferable. In addition, when the gel fraction is 95% or less, appropriate flexibility can be obtained, and the adhesiveness and step followability are further improved, which is preferable.

Specifically, the gel fraction (ratio of solvent-insoluble components) is, for example, a value calculated by the following "Method for measuring gel fraction".

Adhesive layer: About 0.1 g was collected from the adhesive sheet, wrapped in a porous tetrafluoroethylene sheet (trade name “NTF1122”, manufactured by Nitto Denko Co., Ltd.) with an average pore size of 0.2 μm, and tied with a kite string. The weight at that time is measured, and the weight is taken as the weight before immersion. The weight before immersion is the total weight of the adhesive layer (the adhesive layer collected above), the tetrafluoroethylene sheet, and the kite string. Also, the total weight of the tetrafluoroethylene sheet and the kite string is measured, and this weight is taken as the weight of the package.
Next, the adhesive layer wrapped with a tetrafluoroethylene sheet and tied with kite string (referred to as a "sample") is placed in a 50 ml container filled with ethyl acetate and allowed to stand at 23°C for 7 days. After that, remove the sample (after ethyl acetate treatment) from the container, transfer it to an aluminum cup, dry it in a dryer at 130 ° C. for 2 hours to remove ethyl acetate, measure the weight, and immerse the weight. Rear weight.
Then, the gel fraction is calculated from the following formula.
Gel fraction [% (% by weight)] = (XY) / (ZY) x 100

The gel fraction can be controlled by, for example, the monomer composition of the acrylic polymer (A), the weight average molecular weight, the amount of cross-linking agent used (added amount), and the like.

(storage modulus)
The storage modulus of the pressure-sensitive adhesive layer (especially the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) at 25° C. and 1 Hz is not particularly limited, but is preferably 3×10 ⁴ Pa or more. . The configuration in which the pressure-sensitive adhesive layer of the present invention has a storage elastic modulus of 3×10 ⁴ Pa or more at 25° C. and 1 Hz is preferable in that dents are less likely to occur during handling. The storage elastic modulus of the pressure-sensitive adhesive layer of the present invention at 25° C. and 1 Hz is more preferably 5×10 ⁴ Pa or more, more preferably 1×10 ⁵ Pa or more, in that dents on the pressure-sensitive adhesive layer of the present invention can be suppressed. may Although the upper limit of the storage elastic modulus at 25° C. and 1 Hz of the pressure-sensitive adhesive layer of the present invention is not particularly limited, it is preferably 5×10 ⁶ Pa or less, and 1× It may be 10 ⁶ Pa or less.

The storage elastic modulus of the optical pressure-sensitive adhesive sheet of the present invention at 25°C and 1 Hz can be measured by dynamic viscoelasticity measurement, and specifically by the method described in Examples below. The storage elastic modulus of the optical pressure-sensitive adhesive sheet of the present invention at 25° C. and 1 Hz is determined by the composition of the monomers constituting the acrylic polymer (A), the amount of the cross-linking agent, the ionic compound of the present invention, the type of other additives, and the like. Adjustments can be made by adjusting amounts, curing conditions, and the like.

(thickness)
The pressure-sensitive adhesive layer (in particular, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) is not particularly limited, but is preferably 5 to 250 μm, more preferably 7 to 240 μm, 10 to 230 μm, 12 to 220 μm, It may be 15-210 μm, 20-200 μm, 23-175 μm, or 25-150 μm. When the thickness is at least a certain value, the followability to unevenness and adhesion reliability are improved, which is preferable. In addition, when the thickness is a certain value or less, it is particularly excellent in handleability and manufacturability, which is preferable.

The method for producing the pressure-sensitive adhesive layer of the present invention is not particularly limited. For example, it can be produced by preparing the pressure-sensitive adhesive composition (precursor composition) of the present invention and, if necessary, performing irradiation with active energy rays, heat drying, and the like. Specifically, a mixture of monomer components or a partial polymer thereof, the antistatic agent of the present invention (ionic compound having a functional group capable of forming a covalent bond with the acrylic polymer (A) in the molecule), and, if necessary, Depending on the circumstances, it may be produced by adding additives and the like and mixing.

[2-1. Ionic compound of the present invention]
The pressure-sensitive adhesive composition of the present invention contains at least the ionic compound of the present invention (an ionic compound having a functional group capable of forming a covalent bond with the acrylic polymer (A) in the molecule) as an antistatic agent as an essential component. contains. The ionic compound of the present invention is a functional group capable of forming a covalent bond with the acrylic polymer (A) (hereinafter, sometimes referred to as "functional group (A)" in the present specification). It is an ionic compound having a constituent cation part and/or an anion part (either or both). In addition, the ionic compound of the present invention is liquid (liquid) at any temperature within the range of 0 to 150° C., and is preferably a non-volatile molten salt having transparency (ionic liquid). In addition, the ionic compound of this invention can be used individually or in combination of 2 or more types.

When the pressure-sensitive adhesive composition of the present invention contains the ionic compound of the present invention, the acrylic polymer (A) reacts with the functional group (A) of the ionic compound of the present invention to form a covalent bond. As a result, the ionic compound is incorporated into the molecule of the acrylic polymer (A), so even if a large amount of the ionic compound of the present invention is blended, the compatibility in the pressure-sensitive adhesive layer of the present invention is impaired. It becomes easier to maintain transparency. In addition, since bleeding out of the antistatic component can be suppressed even under harsh conditions such as moist and hot environments, precipitation, foaming, and peeling on the surface of the adhesive layer are suppressed, and durability such as appearance and adhesion reliability is improved. defects are less likely to occur. Therefore, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention containing the ionic compound of the present invention can satisfy excellent antistatic properties, transparency, resistance to moist heat, and low staining properties, and is useful. .

The cation moiety of the ionic compound of the present invention can be used without particular limitation, and includes quaternary ammonium cations, imidazolium cations, pyridinium cations, piperinidinium cations, pyrrolidinium cations, quaternary phosphonium cations, tri Alkylsulfonium cations, pyrrole cations, pyrazolium cations, guanidinium cations, and the like, among which quaternary ammonium cations, imidazolium cations, pyridinium cations, piperinidinium cations, pyrrolidinium cations, quaternary Phosphonium cations and trialkylsulfonium cations are more preferably used.

Among the anions constituting the ionic compound of the present invention, the anions include SCN ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ^- ^, ^CF3SO3- ^, ₍ _FSO2 ) _2N- ^, ₍ _CF3SO2 ⁾ _2N- ^, ⁽ _CF3SO2 ₎ _3C- , _AsF6- , _SbF6- , _NbF6- ^, _TaF6 ^- , F ₍ HF) _n- ^, ₍ _CN ) _2N- ^, _C4F9SO3- ^, ₍ _C2F5SO2 ) _2N- ^, _C3F7COO- ^, ₍ _CF3SO2 ) ₍ _CF3CO )N- ^, B ₍ CN) _4- ^, C ⁽ CN) _3- ^, N ₍ _CN ⁾ _2- ^, _CH3OSO3- _, ^C2H5OSO3- _, _C4H9OSO3- _, C ₆ H ₁₃ OSO ₃ ^- , C ₈ H ₁₇ OSO ₃ ^- , p-toluenesulfonate anion, 2-(2-methoxyethyl)ethylsulfate anion, (C ₂ F ₅ ) ₃ PF ₃ ^- and the like, especially , an anion component containing a fluorine atom (fluorine-containing anion) is preferable in terms of obtaining an ionic compound having a low melting point and excellent antistatic properties. As anions, chlorine ions, bromide ions, etc. are preferably not used because they are corrosive.

The functional group (A) (functional group capable of forming a covalent bond with the acrylic polymer (A)) possessed by the ionic compound of the present invention includes, for example, a (meth)acryloyloxy group, a (meth)acryloylamino group, and a vinyl group. , allyl group, styryl group, hydroxyl group, amino group, mercapto group, epoxy group and the like. Among them, a (meth)acryloyloxy group, a (meth)acryloylamino group and a hydroxyl group are preferred, and a (meth)acryloyloxy group copolymerizable with the acrylic polymer (A) is particularly preferred. In this specification, "(meth)acryloyl" represents either one or both of "acryloyl" and "methacryloyl", and the same applies to others. The amino group also includes --NH ₂ and --NHR (R is an alkyl group having 1 to 6 carbon atoms).

The number of functional groups (A) possessed by the ionic compound of the present invention is not particularly limited, but is preferably 1 to 4, more preferably 1 to 3, further preferably 1 or 2, and particularly preferably 1. . When the number of functional groups (A) is two or more, two or more functional groups (A) may be the same or different. When the number of functional groups (A) is 2 or more, the ionic compound of the present invention can also function as a cross-linking agent for cross-linking two or more acrylic polymers (A).

Although the ionic compound of the present invention can be used without any particular limitation, it is preferably an ionic compound represented by the following general formula (A).

In formula (A) above, X ⁺ is a cation moiety. Y ⁻ is an anion. Z ¹ and Z ² are the same or different and each represents a single bond or an alkylene group having 1 to 16 carbon atoms. A ¹ and A ² are the same or different and are functional groups capable of forming a covalent bond with the acrylic polymer (A). n ¹ is 0 or 1, n ² is 0 or 1, provided that n ¹ +n ² is 1 or 2;

The cation moiety (X ⁺ ) constituting the ionic compound represented by the general formula (A) includes a quaternary ammonium group, an imidazolium group, a pyridinium group, a piperinidinium group, a pyrrolidinium group, a pyrrole group and a quaternary phosphonium group. , a trialkylsulfonium group, a pyrazolium group, a guanidinium group, and the like. Among these, a quaternary ammonium group is particularly excellent in transparency and is a preferred embodiment for electronic and optical applications. In addition, quaternary ammonium groups are suitable because they are less likely to inhibit general radical polymerization reactions during ultraviolet (UV) curing and are presumed to have high curability.

As the quaternary ammonium group, when n ¹ +n ² is 1, trimethylammonium group, triethylammonium group, tripropylammonium group, methyldiethylammonium group, ethyldimethylammonium group, methyldipropylammonium group, dimethylbenzyl ammonium group, diethylbenzylammonium group, methyldibenzylammonium group, ethyldibenzylammonium group, dimethyloctadecylammonium group, dimethyloleyl ammonium group, etc.; This is a preferred embodiment because the materials are readily available.

As the quaternary ammonium group, when n ¹ +n ² is 2, dimethylammonium group, diethylammonium group, dipropylammonium group, methylethylammonium group, methylpropylammonium group, methylbenzylammonium group, ethylbenzylammonium group group, methyloctadecylammonium group, ethyloctadecylammonium group, methyloleyl ammonium group, ethyl oleyl ammonium group, etc. Among them, dimethyl ammonium group and methyl oleyl ammonium group are particularly preferable in terms of easy availability of inexpensive industrial materials. It becomes a mode.

Among the anions (sites) (Y ⁻ ) constituting the ionic compound represented by the general formula (A), the anions include SCN ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , NO ₃ ⁻ , CH ₃ COO ⁻ , _CF3COO- _, _CH3SO3- , ^CF3SO3- ^, ₍ _FSO2 ) _2N- _, ₍ _CF3SO2 ) ^2N- ^, ₍ _CF3SO2 ⁾ ^3C- ^, _AsF6- _, _SbF _6- ^, _NbF6- ^, _TaF6- ^, F ₍ HF) _n- ^, ₍ _CN ) _2N- ^, _C4F9SO3- _, ₍ _C2F5SO2 ⁾ _2N- ^, _C3F7COO ^- , ₍ _CF3SO2 ) ₍ _CF3CO )N- ^, B(CN) _4- ^, C ⁽ CN) _3- ^, N ₍ CN ⁾ _2- ^, _CH3OSO3- _, _C2H5OSO3- , C ₄ H ₉ OSO ₃ ⁻ , C ₆ H ₁₃ OSO ₃ ⁻ , C ₈ H ₁₇ OSO ₃ ⁻ , p-toluenesulfonate anion, 2-(2-methoxyethyl)ethylsulfate anion, (C ₂ F ₅ ) ₃ PF ₃ ⁻ and the like are included, and in particular, an anion component containing a fluorine atom (fluorine-containing anion) is preferable because an ionic compound with a low melting point can be obtained and excellent antistatic properties can be obtained. As anions, chlorine ions, bromide ions, and the like are preferably not used because they are corrosive.

Z ¹ and Z ² constituting the ionic compound represented by the general formula (A) are single bonds or alkylene groups having 1 to 16 carbon atoms. The alkylene group having 1 to 16 carbon atoms is preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms, and particularly preferably an alkylene group having 1 to 3 carbon atoms. Specific examples include a methylene group, an ethylene group, a trimethylene group, a methylethylene group, etc., and an ethylene group and a trimethylene group are preferable. When n ¹ +n ² is 2, Z ¹ and Z ² may be the same or different.

A ¹ and A ² constituting the ionic compound represented by the general formula (A) are functional groups capable of forming a covalent bond with the acrylic polymer (A), specifically, a (meth)acryloyloxy group , (meth)acryloylamino group, vinyl group, allyl group, styryl group, hydroxyl group, amino group, mercapto group, epoxy group and the like. Among them, a (meth)acryloyloxy group, a (meth)acryloylamino group and a hydroxyl group are preferred, and a (meth)acryloyloxy group copolymerizable with the acrylic polymer (A) is particularly preferred. When n ¹ +n ² is 2, A ¹ and A ² may be the same or different.

Among the ionic compounds represented by the general formula (A), X ⁺ is a quaternary ammonium group, n ¹ is 1, n ² is 0, A ¹ is a vinyl group, and (meth)acryloyl Specific examples of embodiments that are oxy groups or (meth)acryloylamino groups include N,N,N-trialkyl-N-vinylammonium tetrafluoroborate, N,N,N-trialkyl-N-vinylammonium tri Fluoroacetate, N,N,N-trialkyl-N-vinylammonium heptafluorobutyrate, N,N,N-trialkyl-N-vinylammonium trifluoromethanesulfonate, N,N,N-trialkyl-N-vinyl ammonium perfluorobutanesulfonate, N,N,N-trialkyl-N-vinylammonium bis(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-vinylammonium bis(pentafluoroethanesulfonyl)imide, N, N,N-trialkyl-N-vinylammonium tris(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-vinylammonium hexafluorophosphate, N,N,N-trialkyl-N-vinylammonium ( N,N,N-trialkyl- such as trifluoromethanesulfonyl)trifluoroacetamide, N,N,N-trialkyl-N-vinylammonium dicyanamide, N,N,N-trialkyl-N-vinylammonium thiocyanate N-Vinylammonium cation-containing ionic compounds; N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium tetrafluoroborate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium trifluoroacetate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium heptafluorobutyrate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium trifluoromethanesulfonate, N , N,N-trialkyl-N-(meth)acryloyloxyalkylammonium perfluorobutanesulfonate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium bis(trifluoromethanesulfonyl)imide, N,N , N-trialkyl-N-(meth)acryloyloxyalkylammonium bis(penta fluoroethanesulfonyl)imide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium tris(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium Hexafluorophosphate, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium (trifluoromethanesulfonyl) trifluoroacetamide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium di N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium cation-containing ionic compounds such as cyanamide, N,N,N-trialkyl-N-(meth)acryloyloxyalkylammonium thiocyanate; N , N,N-trialkyl-N-(meth)acryloylaminoalkylammonium tetrafluoroborate, N,N,N-trialkyl-N-(meth)acryloylaminoalkylammonium trifluoroacetate, N,N,N-tri Alkyl-N-(meth)acryloylaminoalkylammonium heptafluorobutyrate, N,N,N-trialkyl-N-(meth)acryloylaminoalkylammonium trifluoromethanesulfonate, N,N,N-trialkyl-N-( meth)acryloylaminoalkylammonium perfluorobutanesulfonate, N,N,N-trialkyl-N-(meth)acryloylaminoalkylammonium bis(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N-(meth) Acryloylaminoalkylammonium bis(pentafluoroethanesulfonyl)imide, N,N,N-trialkyl-N-(meth)acryloylaminoalkylammonium tris(trifluoromethanesulfonyl)imide, N,N,N-trialkyl-N- (Meth) acryloylaminoalkylammonium hexafluorophosphate, N,N,N-trialkyl-N-(meth)acryloylaminoalkylammonium (trifluoromethanesulfonyl) trifluoroacetamide, N,N,N-trialkyl-N-( N,N such as meth)acryloylaminoalkylammonium dicyanamide, N,N,N-trialkyl-N-(meth)acryloylaminoalkylammonium thiocyanate, etc. , N-trialkyl-N-(meth)acryloylaminoalkylammonium cation-containing ionic compounds. The alkyl substituent is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms.

Among the ionic compounds represented by the general formula (A), X ⁺ is a quaternary ammonium group, n ¹ is 1, n ² is 0, and A ¹ is a (meth)acryloyloxy group. Preferred specific examples of certain embodiments include (meth)acryloyloxypropyltrimethylammonium bis(trifluoromethanesulfonyl)imide, (meth)acryloyloxypropyldimethylbenzylammonium bis(trifluoromethanesulfonyl)imide, (meth)acryloyloxyethyltrimethylammonium Bis(trifluoromethanesulfonyl)imide, (meth)acryloyloxyethyldimethylbenzylammonium bis(trifluoromethanesulfonyl)imide, (meth)acryloyloxyethyltrimethylammonium bis(fluorosulfonyl)imide, (meth)acryloyloxyethyldimethylbenzylammonium bis (fluorosulfonyl)imide, (meth)acryloyloxyethyltrimethylammonium trifluoromethanesulfonic acid, (meth)acryloyloxyethyldimethylbenzylammonium trifluoromethanesulfonic acid and the like.

Among the ionic compounds represented by the general formula (A), X ⁺ is a quaternary ammonium group, n ¹ is 1, n ² is 0, and A ¹ is a (meth)acryloylamino group. Preferred specific examples of certain embodiments include (meth)acryloylaminopropyltrimethylammonium bis(trifluoromethanesulfonyl)imide, (meth)acryloylaminopropyldimethylbenzylammonium bis(trifluoromethanesulfonyl)imide, (meth)acryloylaminopropyltrimethylammonium Bis(fluorosulfonyl)imide, (meth)acryloylaminopropyldimethylbenzylammonium bis(fluorosulfonyl)imide, (meth)acryloylaminopropyltrimethylammonium trifluoromethanesulfonic acid, (meth)acryloylaminopropyldimethylbenzylammonium trifluoromethanesulfonic acid, etc. are mentioned.

Among the ionic compounds represented by the general formula (A), X ⁺ is an imidazolium group, n ¹ is 1, n ² is 0 or 1, and A ¹ and A ² are vinyl groups. Specific examples of embodiments include 1-alkyl-3-vinylimidazolium tetrafluoroborate, 1-alkyl-3-vinylimidazolium trifluoroacetate, 1-alkyl-3-vinylimidazolium heptafluorobutyrate, 1-alkyl -3-vinylimidazolium trifluoromethanesulfonate, 1-alkyl-3-vinylimidazolium perfluorobutanesulfonate, 1-alkyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide, 1-alkyl-3-vinylimidazolium bis (Pentafluoroethanesulfonyl)imide, 1-alkyl-3-vinylimidazolium tris(trifluoromethanesulfonyl)imide, 1-alkyl-3-vinylimidazolium hexafluorophosphate, 1-alkyl-3-vinylimidazolium (trifluoromethane 1-alkyl-3-vinylimidazolium cation-containing ionic compounds such as sulfonyl)trifluoroacetamide, 1-alkyl-3-vinylimidazolium dicyanamide, 1-alkyl-3-vinylimidazolium thiocyanate; dialkyl-3-vinylimidazolium bis(fluorosulfonyl)imide, 1,2-dialkyl-3-vinylimidazolium bis(trifluoromethanesulfonyl)imide, 1,2-dialkyl-3-vinylimidazolium dicyanamide, 1, 1,2-dialkyl-3-vinylimidazolium cation-containing ionic compounds such as 2-dialkyl-3-vinylimidazolium thiocyanate; 2-alkyl-1,3-divyvinylimidazolium bis(fluorosulfonyl)imide, 2-alkyl -2-alkyl- such as 1,3-divynylimidazolium bis(trifluoromethanesulfonyl)imide, 2-alkyl-1,3-divynylimidazolium dicyanamide, 2-alkyl-1,3-divynylimidazolium thiocyanate, etc. 1,3-divinylimidazolium cation-containing ionic compounds; 1-vinylimidazolium bis(fluorosulfonyl)imide, 1-vinylimidazolium bis(trifluoromethanesulfonyl)imide, 1-vinylimidazolium dicyanamide, 1-vinyl imidazoli and ionic compounds containing 1-vinylimidazolium cations such as umthiocyanate.

Among the ionic compounds represented by the general formula (A), X ⁺ is an imidazolium group, n ¹ is 1, n ² is 0 or 1, and A ¹ and A ² are (meth)acryloyl Specific examples of embodiments that are oxy groups include 1-alkyl-3-(meth)acryloyloxyalkylimidazolium tetrafluoroborate, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium trifluoroacetate, 1-alkyl -3-(meth)acryloyloxyalkylimidazolium heptafluorobutyrate, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium trifluoromethanesulfonate, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium perfluorobutane Sulfonate, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium bis(trifluoromethanesulfonyl)imide, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium bis(pentafluoroethanesulfonyl)imide, 1-alkyl -3-(meth)acryloyloxyalkylimidazolium tris(trifluoromethanesulfonyl)imide, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium hexafluorophosphate, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium 1-alkyl-3 such as lithium (trifluoromethanesulfonyl) trifluoroacetamide, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium dicyanamide, 1-alkyl-3-(meth)acryloyloxyalkylimidazolium thiocyanate -(meth)acryloyloxyalkylimidazolium cation-containing ionic compound; 1,2-dialkyl-3-(meth)acryloyloxyalkylimidazolium bis(fluorosulfonyl)imide, 1,2-dialkyl-3-(meth)acryloyl Oxyalkylimidazolium bis(trifluoromethanesulfonyl)imide, 1,2-dialkyl-3-(meth)acryloyloxyalkylimidazolium dicyanamide, 1,2-dialkyl-3-(meth)acryloyloxyalkylimidazolium thiocyanate, etc. 1,2-dialkyl-3-(meth)acryloyloxyalkylimidazolium cation-containing ionic compound; 2-alkyl-1,3-di (Meth) acryloyloxyalkylimidazolium bis(fluorosulfonyl)imide, 2-alkyl-1,3-di(meth)acryloyloxyalkylimidazolium bis(trifluoromethanesulfonyl)imide, 2-alkyl-1,3-di( 2-alkyl-1,3-di(meth)acryloyloxyalkylimidazolium cation-containing ions such as meth)acryloyloxyalkylimidazolium dicyanamide, 2-alkyl-1,3-di(meth)acryloyloxyimidazolium thiocyanate 1-(meth)acryloyloxyalkylimidazolium bis(fluorosulfonyl)imide, 1-(meth)acryloyloxyalkylimidazolium bis(trifluoromethanesulfonyl)imide, 1-(meth)acryloyloxyalkylimidazolium dicyanide Examples include ionic compounds containing 1-(meth)acryloyloxyalkylimidazolium cations such as amides and 1-(meth)acryloyloxyalkylimidazolium thiocyanate. The alkyl substituent is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms.

Among the ionic compounds represented by the general formula (A), X ⁺ is an imidazolium group, n ¹ is 1, n ² is 0 or 1, and A ¹ and A ² are (meth)acryloyl Specific examples of amino groups include 1-alkyl-3-(meth)acryloylaminoalkylimidazolium tetrafluoroborate, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium trifluoroacetate, 1-alkyl -3-(meth)acryloylaminoalkylimidazolium heptafluorobutyrate, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium trifluoromethanesulfonate, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium perfluorobutane Sulfonate, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium bis(trifluoromethanesulfonyl)imide, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium bis(pentafluoroethanesulfonyl)imide, 1-alkyl -3-(meth)acryloylaminoalkylimidazolium tris(trifluoromethanesulfonyl)imide, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium hexafluorophosphate, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium 1-alkyl-3 such as lithium (trifluoromethanesulfonyl) trifluoroacetamide, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium dicyanamide, 1-alkyl-3-(meth)acryloylaminoalkylimidazolium thiocyanate -(meth)acryloylaminoalkylimidazolium cation-containing ionic compound; 1,2-dialkyl-3-(meth)acryloylaminoalkylimidazolium bis(fluorosulfonyl)imide, 1,2-dialkyl-3-(meth)acryloyl aminoalkylimidazolium bis(trifluoromethanesulfonyl)imide, 1,2-dialkyl-3-(meth)acryloylaminoalkylimidazolium dicyanamide, 1,2-dialkyl-3-(meth)acryloylaminoalkylimidazolium thiocyanate, etc. 1,2-dialkyl-3-(meth)acryloylaminoalkylimidazolium cation-containing ionic compounds; 2-alkyl-1,3-di (Meth) acryloylaminoalkylimidazolium bis(fluorosulfonyl)imide, 2-alkyl-1,3-di(meth)acryloylaminoalkylimidazolium bis(trifluoromethanesulfonyl)imide, 2-alkyl-1,3-di( 2-alkyl-1,3-di(meth)acryloylaminoalkylimidazolium cation-containing ions such as meth)acryloylaminoalkylimidazolium dicyanamide, 2-alkyl-1,3-di(meth)acryloylaminoimidazolium thiocyanate 1-(meth)acryloylaminoalkylimidazolium bis(fluorosulfonyl)imide, 1-(meth)acryloylaminoalkylimidazolium bis(trifluoromethanesulfonyl)imide, 1-(meth)acryloylaminoalkylimidazolium dicyanide 1-(meth)acryloylaminoalkylimidazolium cation-containing ionic compounds such as amides and 1-(meth)acryloylaminoalkylimidazolium thiocyanate. The alkyl substituent is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms.

Among the ionic compounds represented by the general formula (A), X ⁺ is a pyridinium group, n ¹ is 1, n ² is 0, A ¹ is a vinyl group, a (meth)acryloyloxy group, or (meth)acryloylamino group, 1-vinylpyridinium bis(fluorosulfonyl)imide, 1-vinylpyridinium bis(trifluoromethanesulfonyl)imide, 1-vinylpyridinium dicyanamide, 1-vinyl 1-vinylpyridinium cation-containing ionic compounds such as pyridinium thiocyanate; 1-(meth)acryloyloxyalkylpyridinium cation-containing ionic compounds such as (meth)acryloyloxyalkylpyridinium dicyanamide, 1-(meth)acryloyloxyalkylpyridinium thiocyanate; 1-(meth)acryloylaminoalkylpyridinium bis( 1-(fluorosulfonyl)imide, 1-(meth)acryloylaminoalkylpyridinium bis(trifluoromethanesulfonyl)imide, 1-(meth)acryloylaminoalkylpyridinium dicyanamide, 1-(meth)acryloylaminoalkylpyridinium thiocyanate, etc. (Meth)acryloylaminoalkylpyridinium cation-containing ionic compounds; 2-alkyl-1-vinylpyridinium bis(fluorosulfonyl)imide, 2-alkyl-1-vinylpyridinium bis(trifluoromethanesulfonyl)imide, 2-alkyl-1- 2-alkyl-1-vinylpyridinium cation-containing ionic compounds such as vinylpyridinium dicyanamide, 2-alkyl-1-vinylpyridinium thiocyanate; 2-alkyl-1-(meth)acryloyloxyalkylpyridinium bis(fluorosulfonyl) imide, 2-alkyl-1-(meth)acryloyloxyalkylpyridinium bis(trifluoromethanesulfonyl)imide, 2-alkyl-1-(meth)acryloyloxyalkylpyridinium dicyanamide, 2-alkyl-1-(meth)acryloyl 2-alkyl-1-(meth)acryloyloxyalkyl, such as oxyalkylpyridinium thiocyanate Lupyridinium cation-containing ionic compound; 2-alkyl-1-(meth)acryloylaminoalkylpyridinium bis(fluorosulfonyl)imide, 2-alkyl-1-(meth)acryloylaminoalkylpyridinium bis(trifluoromethanesulfonyl)imide, 2 - 2-alkyl-1-(meth)acryloylaminoalkylpyridinium cation-containing ionic such as alkyl-1-(meth)acryloylaminoalkylpyridinium dicyanamide, 2-alkyl-1-(meth)acryloylaminoalkylpyridinium thiocyanate, etc. Compound; 3-alkyl-1-vinylpyridinium bis(fluorosulfonyl)imide, 3-alkyl-1-vinylpyridinium bis(trifluoromethanesulfonyl)imide, 3-alkyl-1-vinylpyridinium dicyanamide, 3-alkyl-1 - 3-alkyl-1-vinylpyridinium cation-containing ionic compounds such as vinylpyridinium thiocyanate; 3-alkyl-1-(meth)acryloyloxyalkylpyridinium bis(fluorosulfonyl)imide, 3-alkyl-1-(meth) 3-alkyl-1 such as acryloyloxyalkylpyridinium bis(trifluoromethanesulfonyl)imide, 3-alkyl-1-(meth)acryloyloxyalkylpyridinium dicyanamide, 3-alkyl-1-(meth)acryloyloxyalkylpyridinium thiocyanate -(meth)acryloyloxyalkylpyridinium cation-containing ionic compounds; 3-alkyl-1-(meth)acryloylaminoalkylpyridinium bis(fluorosulfonyl)imide, 3-alkyl-1-(meth)acryloylaminoalkylpyridinium bis(trifluoro) 3-alkyl-1-(meth)acryloylamino such as methanesulfonyl)imide, 3-alkyl-1-(meth)acryloylaminoalkylpyridinium dicyanamide, 3-alkyl-1-(meth)acryloylaminoalkylpyridinium thiocyanate, etc. Alkylpyridinium cation-containing ionic compounds; 4-alkyl-1-vinylpyridinium bis(fluorosulfonyl)imide, 4-alkyl-1-vinylpyridinium bis(trifluoromethanesulfonyl)imide, 4-alkyl-1-vinylpyridinium dicyanamide , 4-alkyl-1-vinylpyridinium thiocyanate 4-alkyl-1-vinylpyridinium cation-containing ionic compounds such as; 4-alkyl-1-(meth)acryloyloxyalkylpyridinium bis(fluorosulfonyl)imide, 4-alkyl-1-(meth)acryloyloxyalkylpyridinium bis 4-alkyl-1-(meth), such as (trifluoromethanesulfonyl)imide, 4-alkyl-1-(meth)acryloyloxyalkylpyridinium dicyanamide, 4-alkyl-1-(meth)acryloyloxyalkylpyridinium thiocyanate, etc. Acryloyloxyalkylpyridinium cation-containing ionic compounds; 4-alkyl-1-(meth)acryloylaminoalkylpyridinium bis(fluorosulfonyl)imide, 4-alkyl-1-(meth)acryloylaminoalkylpyridinium bis(trifluoromethanesulfonyl)imide , 4-alkyl-1-(meth)acryloylaminoalkylpyridinium dicyanamide, 4-alkyl-1-(meth)acryloylaminoalkylpyridinium thiocyanate, etc. containing 4-alkyl-1-(meth)acryloylaminoalkylpyridinium cations Examples include ionic compounds. The alkyl substituent is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms.

Among the ionic compounds represented by the general formula (A), X ⁺ is a piperinidinium group, n ¹ is 1, n ² is 0, A ¹ is a vinyl group, a (meth)acryloyloxy group, or a (meth)acryloylamino group, 1-alkyl-1-vinylalkylpiperidinium bis(fluorosulfonyl)imide, 1-alkyl-1-vinylalkylpiperidinium bis(trifluoromethanesulfonyl ) 1-alkyl-1-vinylalkylpiperidinium cation-containing ionic compounds such as imides, 1-alkyl-1-vinylalkylpiperidinium dicyanamides, 1-alkyl-1-vinylalkylpiperidinium thiocyanates; -alkyl-1-(meth)acryloyloxyalkylpiperidinium bis(fluorosulfonyl)imide, 1-alkyl-1-(meth)acryloyloxyalkylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-alkyl-1- 1-Alkyl-1-(meth)acryloyloxyalkylpiperidinium cation-containing ionics such as (meth)acryloyloxyalkylpiperidinium dicyanamide, 1-alkyl-1-(meth)acryloyloxyalkylpiperidinium thiocyanate Compound; 1-alkyl-1-(meth)acryloylaminoalkylpiperidinium bis(fluorosulfonyl)imide, 1-alkyl-1-(meth)acryloylaminoalkylpiperidinium bis(trifluoromethanesulfonyl)imide, 1-alkyl -1-alkyl-1-(meth)acryloylaminoalkylpiperidinium cations such as 1-(meth)acryloylaminoalkylpiperidinium dicyanamide, 1-alkyl-1-(meth)acryloylaminoalkylpiperidinium thiocyanate Contained ionic compounds and the like can be mentioned. The alkyl substituent is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms.

Among the ionic compounds represented by the general formula (A), X ⁺ is a pyrrolidinium group, n ¹ is 1, n ² is 0, A ¹ is a vinyl group, a (meth)acryloyloxy group, or a (meth)acryloylamino group, 1-alkyl-1-vinylalkylpyrrolidinium bis(fluorosulfonyl)imide, 1-alkyl-1-vinylalkylpyrrolidinium bis(trifluoromethanesulfonyl ) 1-alkyl-1-vinylalkylpyrrolidinium cation-containing ionic compounds such as imides, 1-alkyl-1-vinylalkylpyrrolidinium dicyanamides, 1-alkyl-1-vinylalkylpyrrolidinium thiocyanates; 1-alkyl-1-(meth)acryloyloxyalkylpyrrolidinium bis(fluorosulfonyl)imide, 1-alkyl-1-(meth)acryloyloxyalkylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-alkyl-1 - containing 1-alkyl-1-(meth)acryloyloxyalkylpyrrolidinium cations such as (meth)acryloyloxyalkylpyrrolidinium dicyanamide, 1-alkyl-1-(meth)acryloyloxyalkylpyrrolidinium thiocyanate, etc. Ionic compounds; 1-alkyl-1-(meth)acryloylaminoalkylpyrrolidinium bis(fluorosulfonyl)imide, 1-alkyl-1-(meth)acryloylaminoalkylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1 -1-alkyl-1-(meth)acryloylaminoalkylpyrrolidinium such as alkyl-1-(meth)acryloylaminoalkylpyrrolidinium dicyanamide, 1-alkyl-1-(meth)acryloylaminoalkylpyrrolidinium thiocyanate Examples include ionic compounds containing nium cations. The alkyl substituent is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms.

Among the ionic compounds represented by the general formula (A), X ⁺ is a trialkylsulfonium group, n ¹ is 1, n ² is 0, A ¹ is a vinyl group, (meth)acryloyloxy or (meth)acryloylamino group, dialkyl(vinyl)sulfonium bis(fluorosulfonyl)imide, dialkyl(vinyl)sulfonium bis(trifluoromethanesulfonyl)imide, dialkyl(vinyl)sulfonium dicyanide Dialkyl (vinyl) sulfonium cation-containing ionic compounds such as amides, dialkyl (vinyl) sulfonium thiocyanates; Dialkyl ((meth)acryloyloxyalkyl)sulfonium cation-containing ionic compounds such as (trifluoromethanesulfonyl)imide, dialkyl ((meth)acryloyloxyalkyl)sulfonium dicyanamide, dialkyl ((meth)acryloyloxyalkyl)sulfonium thiocyanate; dialkyl((meth)acryloylaminoalkyl)sulfoniumbis(fluorosulfonyl)imide, dialkyl((meth)acryloylaminoalkyl)sulfoniumbis(trifluoromethanesulfonyl)imide, dialkyl((meth)acryloylaminoalkyl)sulfonium dicyanamide, dialkyl dialkyl ((meth)acryloylaminoalkyl)sulfonium cation-containing ionic compounds such as ((meth)acryloylaminoalkyl)sulfonium thiocyanate; The alkyl substituent is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms.

Among the ionic compounds represented by the general formula (A), X ⁺ is a quaternary phosphonium group, n ¹ is 1, n ² is 0, A ¹ is a vinyl group, and (meth)acryloyl Specific examples of embodiments that are an oxy group or a (meth)acryloylamino group include trialkyl(vinyl)phosphonium bis(fluorosulfonyl)imide, trialkyl(vinyl)phosphonium bis(trifluoromethanesulfonyl)imide, trialkyl(vinyl ) phosphonium dicyanamide, trialkyl (vinyl) phosphonium thiocyanate, trialkyl (vinyl) phosphonium cation-containing ionic compounds; trialkyl ((meth) acryloyloxyalkyl) phosphonium bis (fluorosulfonyl) imide, trialkyl (( trialkyl ((meth)acryloyloxyalkyl)phosphonium bis(trifluoromethanesulfonyl)imide, trialkyl((meth)acryloyloxyalkyl)phosphonium dicyanamide, trialkyl((meth)acryloyloxyalkyl)phosphonium thiocyanate, etc. Acryloyloxyalkyl)phosphonium cation-containing ionic compounds; trialkyl((meth)acryloylaminoalkyl)phosphonium bis(fluorosulfonyl)imide, trialkyl((meth)acryloylaminoalkyl)phosphonium bis(trifluoromethanesulfonyl)imide, trialkyl trialkyl((meth)acryloylaminoalkyl)phosphonium cation-containing ionic compounds such as ((meth)acryloylaminoalkyl)phosphonium dicyanamide and trialkyl((meth)acryloylaminoalkyl)phosphonium thiocyanate; The alkyl substituent is preferably an alkyl group having 1 to 16 carbon atoms, more preferably 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms.

Among the ionic compounds represented by the general formula (A), X ⁺ is a quaternary ammonium group, n ¹ is 1, n ² is 1, and A ¹ and A ² are hydroxyl groups. Specific examples include bis(2-hydroxyethyl)-methyl-octylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-decylammonium bis(trifluoromethanesulfonyl)imide, bis(2- Hydroxyethyl)-methyl-dodecylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-tetradecylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-hexadecylammonium Bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-octadecylammonium bis(trifluoromethanesulfonyl)imide, bis(2-hydroxyethyl)-methyl-(9-ene-octadecyl)ammonium bis(trifluoromethane sulfonyl)imide, ethyl-bis(2-hydroxyethyl)-octylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-decylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2- hydroxyethyl)-dodecylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-tetradecylammonium bis(trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-hexadecylammonium bis( trifluoromethanesulfonyl)imide, ethyl-bis(2-hydroxyethyl)-octadecylammonium bis(trifluoromethanesulfonyl)imide, oleylbis(2-hydroxyethyl)methylammonium bis(trifluoromethanesulfonyl)imide, oleyl-ethyl-bis(2 -hydroxyethyl)ammonium bis(trifluoromethanesulfonyl)imide and the like.

Among the ionic compounds represented by the above general formula (A), specific examples of embodiments in which X ⁺ is a pyridinium group, n ¹ is 1, n ² is 0, and A ¹ is a hydroxyl group include: and N-hydroxyethylpyridinium bis(trifluoromethasulfonyl)imide.

Among the ionic compounds represented by the above general formula (A), as a specific example of an aspect in which X ⁺ is an imidazolium group, n ¹ is 1, n ² is 0, and A ¹ is a hydroxyl group, , 1-(2-hydroxyethyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and the like.

Among the ionic compounds represented by the general formula (A), X ⁺ is an imidazolium group or a quaternary ammonium group, n ¹ is 1, n ² is 0, A ¹ and A ² is an amino group, 1-aminopropyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-aminopropyl-3-methylimidazolium dicyanoamide, 1-aminopropyl-3- Methylimidazolium tetrafluoroborate, 1-aminohexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, 1-aminohexyl-3-methylimidazolium dicyanoamide, 1-aminohexyl-3-methylimidazolium tetrafluoro borate, trimethylaminohexylammonium bis(trifluoromethanesulfonyl)imide, trimethylaminohexylammonium dicyanoamide, trimethylaminohexylammonium tetrafluoroborate and the like.

The content of the ionic compound of the present invention is not particularly limited, but from the viewpoint of imparting sufficient antistatic performance to the pressure-sensitive adhesive layer of the present invention, it is preferably 0 per 100 parts by weight of the acrylic polymer (A). 0.01 parts by weight or more, more preferably 0.05 parts by weight or more, more preferably 0.1 parts by weight or more, 0.5 parts by weight or more, or 0.5 parts by weight or more, 1.0 parts by weight or more, 2.0 It may be included in parts by weight or more, 3.0 parts by weight or more, 4.0 parts by weight or more, or 5.0 parts by weight or more. Although the content of the ionic compound of the present invention is not particularly limited, the acrylic polymer (A) 100 It may be contained in an amount of preferably 50 parts by weight or less, more preferably 40 parts by weight or less, still more preferably 30 parts by weight or less, 25 parts by weight or less, 20 parts by weight or less, or 15 parts by weight or less.

[2-2. Acrylic polymer (A)]
The pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) is an acrylic pressure-sensitive adhesive layer containing the acrylic polymer (A) as a main component. Although the specific content of the acrylic polymer (A) is not particularly limited, it is 75% by weight or more (for example, 75 to 99.9% by weight) relative to the total amount of the pressure-sensitive adhesive layer of the present invention (total weight, 100% by weight). ), more preferably 85% by weight or more (for example, 85 to 99.9% by weight).

The adhesive composition for forming the adhesive layer containing the acrylic polymer (A) as a main component is not particularly limited, but for example, a composition containing the acrylic polymer (A) as an essential component; an acrylic polymer ( Examples thereof include a mixture of monomer components constituting A) (sometimes referred to as a "monomer mixture") or a composition containing a partial polymer thereof as an essential component. Although not particularly limited, examples of the former include so-called water-dispersible compositions (emulsion-type compositions), and examples of the latter include so-called active energy ray-curable compositions. In addition, the said adhesive composition may contain the other additive agent as needed.

The above "monomer mixture" includes cases where it is composed of a single monomer component and cases where it is composed of two or more monomer components. Moreover, the above-mentioned "partially polymerized product" means a composition in which one or more of the 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 structural units derived from acrylic monomers as structural units. In other words, the acrylic polymer (A) is a polymer constituted (formed) with an acrylic monomer as an essential monomer component. In this specification, "(meth)acryl" means either one or both of "acryl" and "methacryl", and the same applies to others. Although the weight average molecular weight of the acrylic polymer (A) is not particularly limited, it is preferably from 100,000 to 5,000,000.

The acrylic polymer (A) is a (meth)acrylic acid alkyl ester having a linear or branched alkyl group as an essential monomer unit (hereinafter sometimes simply referred to as "(meth)acrylic acid alkyl ester"). ) is preferred.

Examples of the (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate ((meth) ) n-butyl acrylate), isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, (meth) hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) 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, (meth) Hexadecyl acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, isostearyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, etc., where the alkyl group has 1 to 20 carbon atoms. (Meth)acrylic acid alkyl esters of. In addition, you may use a (meth)acrylic-acid alkylester individually or in combination of 2 or more types.

Among them, the (meth)acrylic acid alkyl ester is preferably a (meth)acrylic acid alkyl ester having an alkyl group with a carbon number of 1 to 18 from the viewpoint of obtaining strong adhesiveness and adjusting residual stress. are methyl methacrylate (MMA), butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), and isostearyl acrylate (ISTA).

The content (percentage) of the (meth)acrylic acid alkyl ester 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, but the adhesion reliability , Especially in terms of adhesion reliability at low temperatures, the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A) is preferably 30 to 95 parts by weight, more preferably 35 to 90 parts by weight, More preferably 40 to 85 parts by weight.

The acrylic polymer (A) may contain a copolymerizable monomer (copolymerizable monomer) in addition to the (meth)acrylic acid alkyl ester as a monomer unit. In other words, the acrylic polymer (A) may contain a copolymerizable monomer as a constituent monomer component. The copolymerizable monomers may be used alone or in combination of two or more.

As the copolymerizable monomer, a hydroxyl group-containing monomer is preferably mentioned. When the acrylic polymer (A) contains a hydroxyl group-containing monomer as a monomer unit, it becomes easy to polymerize the constituent monomer components, and it becomes easy to obtain good cohesive strength. For this reason, it becomes easy to obtain strong adhesiveness, and it becomes easy to obtain excellent anti-foaming peeling property by increasing the gel fraction. Furthermore, it becomes easy to suppress whitening of the adhesive sheet that may occur in a high-humidity environment. Furthermore, the hydroxyl group can also serve as a reaction point with the functional group (A) of the ionic compound of the present invention.

The content (proportion) 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 at least a certain amount, the whitening of the pressure-sensitive adhesive sheet, which may occur in a high-humidity environment, can be further suppressed, and the transparency such as resistance to humid clouding can be ensured. The lower limit of the content of the hydroxyl group-containing monomer is preferably 1 part by weight or more, more preferably 2 parts by weight or more, 3 parts by weight or more, 4 parts by weight or more, 5 parts by weight or more, 6 parts by weight or more, 7 parts by weight or more. It is at least 8 parts by weight, more preferably at least 10 parts by weight. In addition, the upper limit of the content of the hydroxyl group-containing monomer is preferably 40 parts by weight or less, and 35 parts by weight, from the viewpoint of cohesive strength, adhesiveness, and ease of obtaining adhesion reliability such as resistance to foaming and peeling. It is more preferably 34 parts by weight or less, 33 parts by weight or less, 32 parts by weight or less, or 31 parts by weight or less, and even more preferably 30 parts by weight or less.

Furthermore, as the copolymerizable monomer, a nitrogen atom-containing monomer is preferably mentioned. 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, the 180° (degree) peeling adhesive force to the glass plate and the 180° peeling adhesive force to the acrylic plate are increased, making it easier to obtain strong adhesiveness, and increasing the gel fraction to achieve excellent adhesion. It becomes easy to obtain anti-foaming peeling property. Furthermore, it becomes easy to obtain appropriate flexibility in the pressure-sensitive adhesive layer, adjust the 300% tensile residual stress within a specific range, and easily obtain excellent stress relaxation properties and excellent conformability to unevenness.

The content (proportion) of the nitrogen atom-containing monomer relative to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A) is not particularly limited, but is preferably 5 parts by weight or more. The lower limit of the content of the nitrogen atom-containing monomer is 7 parts by weight with respect to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A) from the viewpoint of cohesive strength, adhesiveness, and resistance to foaming and peeling. It is preferably 8 parts by weight or more, more preferably 9 parts by weight or more, or even more preferably 10 parts by weight or more. In addition, the upper limit of the content of the nitrogen atom-containing monomer is 40 parts by weight from the point that it becomes easier to obtain appropriate flexibility in the pressure-sensitive adhesive layer, and it becomes easier to obtain excellent stress relaxation and excellent step conformability. It is preferably 35 parts by weight or less, more preferably 30 parts by weight or less.

The above acrylic polymer (A) can be obtained by polymerizing the above monomer units (monomer components) by a known or commonly used 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 active energy ray irradiation (active energy ray polymerization method). Among them, the solution polymerization method and the active energy ray polymerization method are preferable, and the active energy ray polymerization method is more preferable, from the viewpoints of the transparency, water resistance, cost, etc. of the pressure-sensitive adhesive layer.

Examples of the active energy ray irradiated during the active energy ray polymerization (photopolymerization) include ionizing radiation such as α-ray, β-ray, γ-ray, neutron beam, and electron beam, and ultraviolet rays, particularly ultraviolet rays. is preferred. Moreover, the irradiation energy, irradiation time, irradiation method, and the like of the active energy ray are not particularly limited as long as the photopolymerization initiator can be activated to cause the reaction of the monomer components.

Various common solvents may be used in the polymerization of the acrylic polymer (A). Examples of such solvents 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 organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. In addition, a solvent may be used individually or in combination of 2 or more types.

In addition, when polymerizing 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. In addition, a polymerization initiator may be used individually or in combination of 2 or more types.

The photopolymerization initiator is not particularly limited. Active oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and the like can be mentioned. In addition, a photoinitiator may 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 and the like. Examples of the acetophenone-based photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, 4-phenoxydichloroacetophenone, 4-(t-butyl ) and dichloroacetophenone. Examples of the α-ketol photopolymerization initiator include 2-methyl-2-hydroxypropiophenone, 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one, and the like. be done. Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime-based photopolymerization initiator include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Examples of the benzoin-based photopolymerization initiator include benzoin. Examples of the benzyl-based photopolymerization initiator include benzyl. Examples of the benzophenone-based photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, α-hydroxycyclohexylphenyl ketone, and the like. Examples of the ketal-based photopolymerization initiator include benzyl dimethyl ketal. Examples of the thioxanthone-based photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

The amount of the photopolymerization initiator to be used is not particularly limited. 001 to 1 part by weight, more preferably 0.01 to 0.50 part by weight.

Further, 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 permaleate, etc.), a redox polymerization initiator agents and the like. Among them, the azo polymerization initiator disclosed in JP-A-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-methylpropionate)dimethyl, 4,4′-azobis-4-cyanovaleric acid and the like.

The amount of the thermal polymerization initiator used is not particularly limited. For example, in the case of the azo polymerization initiator, all monomer units of the acrylic polymer (A) (the total amount of monomer components constituting the acrylic polymer (A)) It is preferably 0.05 to 0.5 parts by weight, more preferably 0.1 to 0.3 parts by weight, per 100 parts by weight.

[2-3. Carboxyl group-containing monomer, etc.]
Preferably, the pressure-sensitive adhesive layer does not substantially contain a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A). The phrase "substantially does not contain" means that it is not actively blended except when it is unavoidably mixed. A 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 0.00% relative to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A). 05 parts by weight or less (e.g., 0 to 0.05 parts by weight), more preferably 0.01 parts by weight or less (e.g., 0 to 0.01 parts by weight), still more preferably 0.001 parts by weight or less (e.g., , 0 to 0.001 parts by weight) can be said to be substantially free. Examples of the carboxyl group-containing monomer include (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. Acid anhydride group-containing monomers such as maleic acid and itaconic anhydride are also intended to be included.

Furthermore, when the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer, from the viewpoint of obtaining a more excellent anti-corrosion effect, the pressure-sensitive adhesive layer contains a carboxyl group as a monomer component constituting the acrylic polymer (A). In addition to substantially not containing contained monomers, monomers having acidic groups other than carboxyl groups (sulfo groups, phosphoric acid groups, etc.) are also substantially contained as monomer components constituting the acrylic polymer (A). preferably not. That is, the acrylic polymer (A) preferably contains substantially no carboxyl group-containing monomers and other monomers having acidic groups as constituent monomer components. Specifically, the total amount of the carboxyl group-containing monomers and other monomers having an acidic group as the monomer components constituting the acrylic polymer (A) is the total amount of the monomer components constituting the acrylic polymer (A) (100 parts by weight ), preferably 0.05 parts by weight or less (e.g., 0 to 0.05 parts by weight), more preferably 0.01 parts by weight or less (e.g., 0 to 0.01 parts by weight), more preferably 0 It can be said that the content of 0.001 part by weight or less (for example, 0 to 0.001 part by weight) is substantially absent.

In addition, from the same viewpoint, the pressure-sensitive adhesive layer 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) described later). Or it is preferable not to contain substantially. For example, it is preferred that substantially no carboxyl group-containing monomer is contained. The meaning of "not containing substantially", the preferred degree, and the monomer having an acidic group other than a carboxyl group are the same as in the case of the monomer component constituting the acrylic polymer (A). .

[2-4. Basic group-containing monomer]
In addition, it is preferable that the pressure-sensitive adhesive layer does not contain, or substantially does not contain, a basic group-containing monomer as a monomer component constituting the base polymer. For example, when the pressure-sensitive adhesive layer is an acrylic pressure-sensitive adhesive layer containing an acrylic polymer (A) as a base polymer, a basic group-containing monomer is added as a monomer component constituting a polymer other than the acrylic polymer (A). It is preferable that it does not substantially contain, and even if it is not a monomer component constituting various polymers, it is preferable that the pressure-sensitive adhesive layer does not substantially contain a basic group-containing monomer. is the same as for In addition, the same applies to the meaning of "substantially free of", the preferred degree, and the like.

[2-5. Hydroxyl Group-Containing Monomer]
A hydroxyl group-containing monomer means a monomer having at least one hydroxyl group in the molecule. Also, 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. The hydroxyl group-containing monomer is not particularly limited, but specific examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, ( 3-hydroxypropyl meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, hydroxydecyl (meth)acrylate, (meth)acrylic acid hydroxyl group-containing (meth)acrylic acid esters such as hydroxyllauryl and (meth)acrylic acid (4-hydroxymethylcyclohexyl); vinyl alcohol, allyl alcohol and the like. 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), acrylic acid 4 - hydroxybutyl (4HBA). Incidentally, the hydroxyl group-containing monomers may be used alone or in combination of two or more.

[2-6. Nitrogen Atom-Containing Monomer]
A nitrogen atom-containing monomer means a monomer having at least one nitrogen atom in its molecule (in one molecule). However, the hydroxyl group-containing monomer does not include the nitrogen atom-containing monomer. That is, in this specification, a monomer having a hydroxyl group and a nitrogen atom in its molecule is included in the nitrogen atom-containing monomer. Also, 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.

From the viewpoint of improving resistance to foaming and peeling, N-vinyl cyclic amides, (meth)acrylamides, and the like are preferable as the nitrogen atom-containing monomer. Incidentally, the nitrogen atom-containing monomers may be used alone or in combination of two or more.

As the N-vinyl cyclic amide, an N-vinyl cyclic amide represented by the following formula (1) is preferable.

(In formula (1), R ¹ represents a divalent organic group)

R ¹ in the above formula (1) is a divalent organic group, preferably a divalent saturated hydrocarbon group or an unsaturated hydrocarbon group, more preferably a divalent saturated hydrocarbon group (e.g., carbon number 3 to 5 alkylene groups, etc.).

As the N-vinyl cyclic amide represented by the above formula (1), N-vinyl-2-pyrrolidone (NVP), N-vinyl-2-piperidone, N-vinyl -2-caprolactam, N-vinyl-3-morpholinone, N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione and the like are preferred, more preferably N-vinyl-2- pyrrolidone, N-vinyl-2-caprolactam, 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, N-octylacrylamide and the like. Furthermore, the above N-alkyl(meth)acrylamides also include (meth)acrylamides having an amino group such as dimethylaminoethyl(meth)acrylamide, diethylaminoethyl(meth)acrylamide, and dimethylaminopropyl(meth)acrylamide. Examples of the N,N-dialkyl(meth)acrylamides include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, N,N-diisopropyl (Meth)acrylamide, N,N-di(n-butyl)(meth)acrylamide, N,N-di(t-butyl)(meth)acrylamide and the like.

The (meth)acrylamides also 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, N-(2-hydroxypropyl)(meth)acrylamide, N- (1-hydroxypropyl)(meth)acrylamide, N-(3-hydroxypropyl)(meth)acrylamide, N-(2-hydroxybutyl)(meth)acrylamide, N-(3-hydroxybutyl)(meth)acrylamide, N-(4-hydroxybutyl)(meth)acrylamide, N-methyl-N-2-hydroxyethyl(meth)acrylamide and the like.

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

Nitrogen atom-containing monomers other than the N-vinyl cyclic amides and the (meth)acrylamides include, for example, aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylamino (meth)acrylate propyl, 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-vinyl imidazole, N-vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyridine, vinylpyrimidine, vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth)acryloylpyrrolidone, (meth)acryloyl heterocyclic ring-containing monomers such as pyrrolidine, (meth)acryloylpiperidine and N-methylvinylpyrrolidone; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide, N-methylitaconimide , N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-laurylitaconimide, N-cyclohexylitaconimide and other itaconimide monomers, N-(meth)acryloyl imide group-containing monomers such as succinimide monomers such as oxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; 2-(meth)acryloyloxy Examples thereof include isocyanate group-containing monomers such as ethyl isocyanate.

[2-7. Alicyclic Structure-Containing Monomer]
Copolymerizable monomers other than nitrogen atom-containing monomers and hydroxyl group-containing monomers further include alicyclic structure-containing monomers. The alicyclic structure-containing monomer is not particularly limited as long as it has a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group and has an alicyclic structure. For example, an alkyl (meth)acrylate having a cycloalkyl group is included in the alicyclic structure-containing monomer. In addition, an alicyclic structure containing monomer can be used individually or in combination of 2 or more types.

The alicyclic structure in the alicyclic structure-containing monomer is a cyclic hydrocarbon structure, preferably having 5 or more carbon atoms, more preferably 6 to 24 carbon atoms, further preferably 6 to 15 carbon atoms, and 6 to 10 are particularly preferred.

Examples of the alicyclic structure-containing monomer include cyclopropyl (meth)acrylate, cyclobutyl (meth)acrylate, cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, cyclooctyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, HPMPA represented by the following formula (2), TMA-2 represented by the following formula (3), HCPA represented by the following formula (4), etc. (Meth)acrylic monomers. In the following formula (4), there is no particular limitation on the bonding position between the cyclohexyl ring connected by a line and the structural formula in parentheses. Among these, isobornyl (meth)acrylate is preferred.

When the acrylic polymer contains the alicyclic structure-containing monomer as a monomer component constituting the polymer, the alicyclic structure-containing monomer in all the monomer components (100% by weight) constituting the acrylic polymer (A) Although the proportion of the monomer is not particularly limited, it is preferably 10% by weight or more from the viewpoint of improving durability and obtaining high adhesion reliability. In addition, the upper limit of the ratio of the alicyclic structure-containing monomer is preferably 50% by weight or less, more preferably 40% by weight or less, and still more preferably 30% by weight or less, from the viewpoint of obtaining a pressure-sensitive adhesive layer having appropriate flexibility. is.

[2-8. Other copolymerizable monomers]
Examples of copolymerizable monomers in the acrylic polymer (A) include, in addition to the above nitrogen atom-containing monomers and hydroxyl group-containing monomers, (meth)acrylic acid alkoxyalkyl esters [for example, 2-methoxyethyl (meth)acrylate , 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate , 4-ethoxybutyl (meth)acrylate, etc.]; epoxy group-containing monomers [e.g., glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, etc.]; sulfonic acid group-containing monomers [e.g., sodium vinyl sulfonate, etc. ]; phosphoric acid group-containing monomer; (meth) acrylic acid ester having an aromatic hydrocarbon group [e.g., phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, etc.]; vinyl ester analogues [e.g., vinyl acetate, vinyl propionate, etc.]; aromatic vinyl compounds [e.g., styrene, vinyltoluene, etc.]; olefins or dienes [e.g., ethylene, propylene, butadiene, isoprene, isobutylene, etc.]; vinyl ethers [e.g. For example, vinyl alkyl ether, etc.]; vinyl chloride, etc. may be mentioned.

Furthermore, the copolymerizable monomers in the acrylic polymer (A) also include polyfunctional monomers. A polyfunctional monomer acts as a cross-linking component. Examples of the polyfunctional monomer include 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, tetramethylolmethane tri(meth)acrylate, Allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate and the like. In addition, a polyfunctional monomer may be used individually or in combination of 2 or more types.

The content (proportion) of the polyfunctional monomer in all monomer units of the acrylic polymer (A) is not particularly limited, but with respect to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (A), It is preferably 0.5 parts by weight or less (for example, 0 to 0.5 parts by weight), more preferably 0 to 0.35 parts by weight, still more preferably 0 to 0.3 parts by weight. When the content of the polyfunctional monomer is 0.5 parts by weight or less, the pressure-sensitive adhesive layer has appropriate cohesive strength, and the pressure-sensitive adhesive strength and step absorbability are easily improved, which is preferable. In addition, when using a cross-linking agent, the polyfunctional monomer may not be used, but the content of the multi-functional monomer when the cross-linking agent is not used is preferably 0.001 to 0.5 parts by weight. , more preferably 0.001 to 0.35 parts by weight, more preferably 0.002 to 0.3 parts by weight.

[2-9. Acrylic polymer (B)]
When the pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention) contains an acrylic polymer (A) as a base polymer, the pressure-sensitive adhesive layer, together with the acrylic polymer (A), It preferably contains an acrylic polymer (B) having a weight average molecular weight of 1,000 to 30,000. When the acrylic polymer (B) is contained, the adhesion to the adherend at the interface of the pressure-sensitive adhesive sheet is improved, so that it becomes easy to obtain strong adhesion and excellent resistance to foaming and peeling. In this specification, "acrylic polymer (B) having a weight average molecular weight of 1000 to 30000" may be simply referred to as "acrylic polymer (B)".

As the acrylic polymer (B), an acrylic polymer composed of a (meth)acrylic ester having a cyclic structure in the molecule as an essential monomer component is preferably mentioned, and a (meth) having a cyclic structure in the molecule. An acrylic polymer composed of an acrylic acid ester and a (meth)acrylic acid alkyl ester having a linear or branched alkyl group as essential monomer components is more preferable. 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 has a cyclic structure in the molecule as a monomer unit (meth) ) Acrylic polymers containing acrylic acid esters and (meth)acrylic acid alkyl esters having linear or branched alkyl groups are more preferred.

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 , a non-aromatic ring, and is not particularly limited. Examples of the aromatic ring include aromatic carbocyclic rings [eg, monocyclic carbocyclic rings such as benzene ring, condensed carbocyclic rings such as naphthalene ring, etc.], various aromatic heterocyclic rings, and the like. Examples of the non-aromatic ring include non-aromatic aliphatic rings (non-aromatic alicyclic rings) [e.g., cycloalkane rings such as cyclopentane ring, cyclohexane ring, cycloheptane ring, and cyclooctane ring cycloalkene rings such as cyclohexene rings], non-aromatic bridging rings [e.g., bicyclic hydrocarbon rings in pinane, pinene, bornane, norbornane, norbornene, etc.; tricyclic or higher aliphatic hydrocarbons in adamantane, etc. ring (bridged hydrocarbon ring), etc.], non-aromatic heterocyclic ring [eg, epoxy ring, oxolane ring, oxetane ring, etc.], and the like.

Examples of the tricyclic or higher aliphatic hydrocarbon ring (tricyclic or higher bridged hydrocarbon ring) include, for example, a dicyclopentanyl group represented by the following formula (5a), and a dicyclopentanyl group represented by the following formula (5b). a dicyclopentenyl group represented by the following formula (5c), an adamantyl group represented by the following formula (5d), a tricyclopentenyl group represented by the following formula (5d), a tricyclopentenyl group represented by the following formula (5e), and the like. .

That is, examples of the ring-containing (meth)acrylic acid ester include (meth)acrylic esters such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate. Acrylic acid cycloalkyl ester; (meth)acrylic acid ester having a bicyclic aliphatic hydrocarbon ring such as isobornyl (meth)acrylate; dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth) Tricyclic or higher aliphatics such as acrylates, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, 2-ethyl-2-adamantyl (meth)acrylate (Meth)acrylic acid esters having a hydrocarbon ring; (meth)acrylic acid aryl esters such as phenyl (meth)acrylate, (meth)acrylic acid aryloxyalkyl esters such as phenoxyethyl (meth)acrylate, (meth)acrylic acid esters Examples thereof include (meth)acrylic acid esters having an aromatic ring, such as (meth)acrylic acid arylalkyl esters such as benzyl acrylate. 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), acrylic Dicyclopentanyl acid (DCPA) and 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, a (meth)acrylic acid ester having a tricyclic or higher aliphatic hydrocarbon ring (particularly, a tricyclic or higher bridging hydrocarbon ring) is used. This is particularly preferable in that polymerization inhibition is less likely to occur. Further, a dicyclopentanyl group having no unsaturated bond represented by the above formula (5a), an adamantyl group represented by the above formula (5c), and a tricyclopentanyl group represented by the above formula (5d) When using a (meth) acrylic acid ester having, it is possible to further increase the resistance to foaming and peeling, and furthermore, the adhesion to low-polar adherends such as polyethylene and polypropylene can be significantly improved. .

The content (percentage) of the ring-containing (meth)acrylic acid ester 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, but the acrylic polymer 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 components constituting (B). When the content of the ring-containing (meth)acrylic acid ester is 10 parts by weight or more, the resistance to foaming and peeling is easily improved, which is preferable. Moreover, when the content is 90 parts by weight or less, the pressure-sensitive adhesive layer has appropriate flexibility, and the pressure-sensitive adhesive strength, step absorbability, etc. are likely to be improved, which is preferable.

Examples of the (meth)acrylic acid alkyl ester having a linear or branched alkyl group as the monomer unit of the acrylic polymer (B) include methyl (meth)acrylate and ethyl (meth)acrylate. , propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, (meth)acrylate Pentyl acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, (meth) ) nonyl acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, (meth)acrylate Alkyl groups such as tetradecyl acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, etc. Examples thereof include (meth)acrylic acid alkyl esters having 1 to 20 carbon atoms. Among them, methyl methacrylate (MMA) is preferable because it has good compatibility with the acrylic polymer (A). In addition, said (meth)acrylic-acid alkylester may be used individually or in combination of 2 or more types.

Content (percentage) of (meth)acrylic acid alkyl ester having a linear or branched alkyl group in all monomer units of acrylic polymer (B) (total amount of monomer components constituting acrylic polymer (B)) is not particularly limited, but 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 components constituting the acrylic polymer (B) in terms of resistance to foaming and peeling. parts by weight, more preferably 20 to 60 parts by weight. When the content is 10 parts by weight or more, the adhesive strength to an adherend made of 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)acrylic acid alkyl ester having a linear or branched alkyl group, these monomers and A polymerizable monomer (copolymerizable monomer) may be included. The content (proportion) of the copolymerizable monomer 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, but the acrylic polymer (B ) is preferably 49.9 parts by weight or less (eg, 0 to 49.9 parts by weight), more preferably 30 parts by weight or less, relative to the total amount (100 parts by weight) of the monomer components constituting Also, the copolymerizable monomers may be used alone or in combination of two or more.

Examples of the copolymerizable monomer (the copolymerizable monomer constituting the acrylic polymer (B)) as monomer units of the acrylic polymer (B) include (meth)acrylic acid alkoxyalkyl esters [for example, (meth) ) 2-methoxyethyl acrylate, 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 3-methoxypropyl (meth) acrylate, 3-ethoxypropyl (meth) acrylate, (meth) ) 4-methoxybutyl acrylate, 4-ethoxybutyl (meth)acrylate, etc.]; hydroxyl group (hydroxyl group)-containing monomers [e.g., 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, Hydroxyalkyl (meth)acrylates such as 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate, vinyl alcohol, allyl alcohol, etc.]; amide group-containing monomers [e.g., (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methoxymethyl(meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-hydroxyethyl (meth)acrylamide, etc.]; amino group-containing monomers [e.g., aminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, t-butylaminoethyl (meth)acrylate etc.]; cyano group-containing monomers [e.g., acrylonitrile, methacrylonitrile, etc.]; sulfonic acid group-containing monomers [e.g., sodium vinyl sulfonate, etc.]; ; isocyanate group-containing monomers [eg, 2-methacryloyloxyethyl isocyanate], imide group-containing monomers [cyclohexylmaleimide, isopropylmaleimide, etc.], and the like.

As described above, the acrylic polymer (B) includes, as monomer units, a (meth)acrylic acid ester having a cyclic structure in the molecule and a (meth)acrylic acid alkyl ester having a linear or branched alkyl group. Acrylic polymers are preferred. Among them, an acrylic polymer containing, as monomer units, a ring-containing (meth)acrylic acid ester and a (meth)acrylic acid alkyl ester having a linear or branched alkyl group is preferred. 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 monomer units, a monomer component constituting the acrylic polymer (B) The amount of the ring-containing (meth)acrylic acid ester relative to the total amount (100 parts by weight) is not particularly limited, but is preferably 10 to 90 parts by weight, more preferably 20 to 80 parts by weight. The content of the (meth)acrylic acid alkyl ester 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, and even more preferably 20 to 60 parts by weight.

Furthermore, as a particularly preferred specific structure of the acrylic polymer (B), the monomer unit is (1) selected from the group consisting of dicyclopentanyl acrylate, dicyclopentanyl methacrylate, cyclohexyl acrylate, and cyclohexyl methacrylate. and (2) an acrylic polymer containing methyl methacrylate. Among all the monomer units of the acrylic polymer (B) having a particularly preferred specific configuration, (1) dicyclopentanyl acrylate, dicyclopentanyl methacrylate, cyclohexyl acrylate, and the content of cyclohexyl methacrylate (the total amount of these when two or more are included) is 30 to 70 parts by weight with respect to the total amount (100 parts by weight) of the monomer components constituting the acrylic polymer (B), 2) The content of methyl methacrylate is preferably 30 to 70 parts by weight. However, the acrylic polymer (B) is not limited to the above specific configuration.

The acrylic polymer (B) can be obtained by polymerizing the above monomer components by a known or commonly used 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 active energy ray irradiation (active energy ray polymerization method). Among them, the bulk polymerization method and the solution polymerization method are preferable, and the solution polymerization method is more preferable.

Various common solvents may be used in the polymerization of the acrylic polymer (B). 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; cyclohexane, methylcyclohexane and the like. alicyclic hydrocarbons; and organic solvents such as ketones such as methyl ethyl ketone and methyl isobutyl ketone. In addition, such a solvent may be used individually or in combination of 2 or more types.

Furthermore, a known or commonly used polymerization initiator (for example, a thermal polymerization initiator, a photopolymerization initiator, etc.) may be used in the polymerization of the acrylic polymer (B). In addition, a polymerization initiator may be used individually or in combination of 2 or more types.

Examples of thermal polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile (AMBN), 2,2'-azobis(2- methylpropionate) 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) and other azo initiators; benzoyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1- Examples include peroxide-based initiators such as bis(t-butylperoxy)cyclododecane. In addition, when performing solution polymerization, it is preferable to use an oil-soluble polymerization initiator. Moreover, a thermal polymerization initiator may be used individually or in combination of 2 or more types.

The amount of the thermal polymerization initiator to be used is not particularly limited. .1 to 15 parts by weight.

The photopolymerization initiator is not particularly limited, but includes, for example, the same photopolymerization initiator as the photopolymerization initiator used in the polymerization of the acrylic polymer (A) mentioned above. The amount of the photopolymerization initiator to be used is not particularly limited, and is appropriately selected.

A chain transfer agent may be used in the polymerization of the acrylic polymer (B) to adjust the molecular weight (specifically, to adjust the weight average molecular weight to 1000 to 30000). Examples of the chain transfer agent include 2-mercaptoethanol, α-thioglycerol, 2,3-dimercapto-1-propanol, octyl mercaptan, t-nonyl mercaptan, dodecyl mercaptan (lauryl mercaptan), t-dodecyl mercaptan, glycidyl mercaptan, thioglycolic acid, methyl thioglycolate, ethyl thioglycolate, propyl thioglycolate, butyl thioglycolate, t-butyl thioglycolate, 2-ethylhexyl thioglycolate, octyl thioglycolate, isooctyl thioglycolate, decyl thioglycolate, dodecyl thioglycolate, ethylene glycol thioglycolate, neopentyl glycol thioglycolate, pentaerythritol thioglycolate, α-methylstyrene dimer and the like. Among them, α-thioglycerol and methyl thioglycolate are preferred, and α-thioglycerol is particularly preferred, from the viewpoint of suppressing whitening of the adhesive sheet due to humidification. In addition, a chain transfer agent may be used individually or in combination of 2 or more types.

The content (amount used) of the chain transfer agent is not particularly limited, but is 0 per 100 parts by weight of all monomer units of the acrylic polymer (B) (the total amount of the monomer components constituting the acrylic polymer (B)). .1 to 20 parts by weight is preferred, more preferably 0.2 to 15 parts by weight, and still more preferably 0.3 to 10 parts by weight. By setting the content (use amount) of the chain transfer agent within the above range, an acrylic polymer having a weight average molecular weight controlled to 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 still more preferably 2,000 to 8,000. Since the acrylic polymer (B) has a weight-average molecular weight of 1000 or more, the adhesive strength and holding properties are improved, and the resistance to foaming and peeling is improved. On the other hand, since the acrylic polymer (B) has a weight-average molecular weight of 30,000 or less, the adhesive strength is easily increased, and the resistance to foaming and peeling is improved.

The weight-average molecular weight (Mw) of the acrylic polymer (B) can be determined by the GPC method in terms of polystyrene. For example, it can be measured under the following conditions using a 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

Although the glass transition temperature (Tg) of the acrylic polymer (B) is not particularly limited, it is preferably 20 to 300°C, more preferably 30 to 300°C, and even more preferably 40 to 300°C. When the glass transition temperature of the acrylic polymer (B) is 20° C. or higher, the resistance to foaming and peeling is likely to be improved, which is preferable. In addition, when the glass transition temperature of the acrylic polymer (B) is 300° C. or less, the pressure-sensitive adhesive layer has appropriate flexibility, and it becomes easy to obtain good adhesive strength and good step absorbability, resulting in excellent adhesion. This is preferable because it makes it easier to obtain reliability.

The glass transition temperature (Tg) of the acrylic polymer (B) is the glass transition temperature (theoretical value) represented by the following formula.
₁ /Tg ₌ W1 _/ Tg1 ₊ W2/Tg2+...+ _Wn / _Tgn
In the above formula, Tg is the glass transition temperature (unit: K) of the acrylic polymer (B), Tg is the glass transition temperature (unit: K) when the monomer _i forms a homopolymer, and W is the temperature of the monomer _i . It represents the weight fraction in the total amount of monomer components (i=1, 2, . . . n).
As the Tg of the homopolymer of the monomers constituting the acrylic polymer (B), the values shown in Table 1 below can be adopted. As the Tg of homopolymers of monomers not listed in Table 1, values described in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) can be used. Furthermore, as the Tg of a homopolymer of a monomer not described in the above literature, the value obtained by the above-described measuring method (tan δ peak top temperature by viscoelasticity test) can be employed.

The copolymer "DCPMA/MMA=60/40" in Table 1 means a copolymer of 60 parts by weight of DCPMA and 40 parts by weight of MMA.

The content of the acrylic polymer (B) when the pressure-sensitive adhesive layer contains the acrylic polymers (A) and (B) is not particularly limited. It is preferably 1 to 30 parts by weight, more preferably 2 to 20 parts by weight, still more preferably 2 to 10 parts by weight. That is, the content of the acrylic polymer (B) in the pressure-sensitive adhesive layer is not particularly limited, but is preferably 1 to 30 parts by weight with respect to 100 parts by weight of all monomer units of the acrylic polymer (A), and more It is preferably 2 to 20 parts by weight, more preferably 2 to 10 parts by weight. The content of the acrylic polymer (B) in the adhesive layer is not particularly limited. , more 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 resistance to foaming and peeling can be easily obtained, which is preferable. Moreover, when the content of the acrylic polymer (B) is 30 parts by weight or less, excellent transparency and adhesion reliability can be easily obtained, which is preferable.

The method for producing the pressure-sensitive adhesive layer containing the acrylic polymers (A) and (B) is not particularly limited. For example, a mixture of monomer components constituting the acrylic polymer (A) or a partial polymer of a mixture of monomer components constituting the acrylic polymer (A) (a monomer mixture forming the acrylic polymer (A) or a partial polymer thereof ), the acrylic polymer (B), additives and the like are added as necessary and mixed.

[2-10. Antistatic agent other than the ionic compound of the present invention]
The pressure-sensitive adhesive layer of the present invention may optionally contain an antistatic agent other than the ionic compound of the present invention (herein, may be referred to as "other antistatic agent"). .
Examples of other antistatic agents include materials capable of imparting antistatic properties, such as ionic compounds, ionic surfactants, conductive polymers, and conductive fine particles. Among these, ionic compounds are preferred from the viewpoint of compatibility with the acrylic polymer (A) and transparency of the pressure-sensitive adhesive layer.

As the ionic compound, an inorganic cation anion salt and/or an organic cation anion salt can be preferably used, and it is particularly preferable to use an inorganic cation anion salt. An ionic compound containing an inorganic cation (inorganic cation anion salt) is more preferable than an organic cation anion salt because it can suppress a decrease in adhesiveness (anchor force) of the pressure-sensitive adhesive layer when used. The term "inorganic cation anion salt" as used in the present invention generally indicates an alkali metal salt formed from an alkali metal cation and an anion, and the alkali metal salt includes an organic salt and an inorganic salt of an alkali metal. can be used. In addition, the term "organic cation anion salt" as used in the present invention means an organic salt, the cation portion of which is composed of an organic substance, and the anion portion may be an organic substance or an inorganic substance. can be "Organic cation anion salts" are also referred to as ionic liquids and ionic solids. As the anion component constituting the ionic compound, it is preferable to use a fluorine-containing anion from the viewpoint of antistatic function.

Examples of alkali metal ions that make up the cation portion of the alkali metal salt include ions of lithium, sodium, and potassium. Among these alkali metal ions, lithium ions are preferred.

The anion portion of the alkali metal salt may be composed of an organic substance or may be composed of an inorganic substance. Examples of the anion moiety constituting the organic salt include CH ₃ COO ⁻ , CF ₃ COO ⁻ , CH ₃ SO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , C ₄ F ₉ SO ₃ ^- ^, _C3F7COO- ^, ₍ _CF3SO2 ⁾ ₍ _CF3CO ) ^N- ^, _-O3S ( _CF2 ) _3SO3- ^, _PF6- _, _CO32- , or the following general formula ( 1) to (4),
(1): (C _n F _2n+1 SO ₂ ) ₂ N ⁻ (where n is an integer of 1 to 10),
(2): CF ₂ (C _m F _2m SO ₂ ) ₂ N ⁻ (where m is an integer of 1 to 10),
(3): ^- O ₃ S(CF ₂ ) _l SO ₃ ^- (where l is an integer of 1 to 10),
(4): (C _p F _2p+1 SO ₂ )N ⁻ (C _q F _2q+1 SO ₂ ), (where p and q are integers from 1 to 10), and (FSO ₂ ) ₂ N ⁻ Those represented by are used. In particular, an anion moiety containing a fluorine atom is preferably used because an ionic compound having good ion dissociation properties can be obtained. Examples of the anion moiety constituting the inorganic salt include Cl ⁻ , Br ⁻ , I ⁻ , AlCl ₄ ⁻ , Al ₂ Cl ₇ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , ClO ₄ ⁻ , NO ₃ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , NbF ₆ ⁻ , TaF ₆ ⁻ , (CN) ₂ N ⁻ , etc. are used. Among anions containing a fluorine atom, fluorine-containing imide anions are preferable, and among these, bis(trifluoromethanesulfonyl)imide anions and bis(fluorosulfonyl)imide anions are preferable. In particular, a bis(fluorosulfonyl)imide anion is preferable because it can impart excellent antistatic properties even when added in a relatively small amount, maintains adhesive properties, and is advantageous for durability in a humidified or heated environment.

Specific examples of alkali metal organic salts include sodium acetate, sodium alginate, sodium _{ligninsulfonate} , sodium toluenesulfonate, _LiCF3SO3 _, Li ₍ _CF3SO2 )2N, Li ₍ _CF3SO2 ). )2N, Li ₍ _C2F5SO2 )2N _, Li ₍ _C4F9SO2 ) _2N _, Li ₍ _CF3SO2 ) _3C _, _KO3S ₍ _CF2 ) _3SO3K _, LiO ₃ S(CF ₂ ) ₃ SO ₃ K, among others, LiCF ₃ SO ₃ , Li(FSO ₂ ) ₂ N, Li(CF ₃ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ ) ₂ N, Li(C ₄ F ₉ SO ₂ ) ₂ N, Li(CF ₃ SO ₂ ) ₃ C, etc. are preferred, and Li(CF ₃ SO ₂ ) ₂ N, Li(C ₂ F ₅ SO ₂ ) ₂ N , Li(C ₄ F ₉ SO ₂ ) ₂ N and the like are more preferred, and bis(trifluoromethanesulfonyl)imidelithium and bis(fluorosulfonyl)imidelithium are particularly preferred.

Inorganic salts of alkali metals include lithium perchlorate and lithium iodide.

An organic cation anion salt is composed of a cation component and an anion component, and the cation component is composed of an organic substance. Specific examples of cationic components include pyridinium cations, piperidinium cations, pyrrolidinium cations, cations having a pyrroline skeleton, cations having a pyrrole skeleton, imidazolium cations, tetrahydropyrimidinium cations, dihydropyrimidinium cations, Examples include pyrazolium cations, pyrazolinium cations, tetraalkylammonium cations, trialkylsulfonium cations, tetraalkylphosphonium cations, and the like.

Examples of anion components include Cl ^- , Br ^- , I ^- , AlCl ₄ ^- , Al ₂ Cl ₇ ^- , BF ₄ ^- , PF ₆ ^- , ClO ₄ ^- , NO ₃ ^- , CH ₃ COO ^- , CF ₃ COO ^- ^, _CH3SO3- _, ^CF3SO3- ^, ₍ _CF3SO2 ⁾ _3C- _, ^AsF6- ^, _SbF6- ^, _NbF6- , _TaF6- ^, ₍ CN) _2N- ^, _C4F ₉ SO ₃ ⁻ , C ₃ F ₇ COO ⁻ , ((CF ₃ SO ₂ )(CF ₃ CO) N ⁻ ^, —O ₃ S(CF ₂ ) ₃ SO ₃ ⁻ , and compounds represented by the following general formulas (1) to (4) ),
(1): (C _n F _2n+1 SO ₂ ) ₂ N ⁻ (where n is an integer of 1 to 10),
( ₂ ): CF2 ₍ _CmF2mSO2 ) _2N- ⁽ where _m is an integer of 1 to 10),
(3): ^- O ₃ S(CF ₂ ) _l SO ₃ ^- (where l is an integer of 1 to 10),
(4): (C _p F _2p+1 SO ₂ )N ⁻ (C _q F _2q+1 SO ₂ ), (where p and q are integers from 1 to 10), and (FSO ₂ ) ₂ N ⁻ Those represented by are used. Among these, anions containing a fluorine atom (fluorine-containing anions) are particularly preferred because they yield ionic compounds with good ion dissociation properties. Among anions containing a fluorine atom, fluorine-containing imide anions are preferable, and among these, bis(trifluoromethanesulfonyl)imide anions and bis(fluorosulfonyl)imide anions are preferable. In particular, a bis(fluorosulfonyl)imide anion is preferable because it can impart excellent antistatic properties even when added in a relatively small amount, maintains adhesive properties, and is advantageous for durability in a humidified or heated environment.

In addition to the above inorganic cation anion salts (alkali metal salts) and organic cation anion salts, the ionic compounds include inorganic compounds such as ammonium chloride, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, and ammonium sulfate. salt. These ionic compounds can be used alone or in combination.

Examples of ionic surfactants include cationic surfactants (e.g., quaternary ammonium salt type, phosphonium salt type, sulfonium salt type, etc.) and anionic surfactants (carboxylic acid type, sulfonate type, sulfate type, phosphate type, phosphite type, etc.). , Zwitterionic (sulfobetaine type, alkylbetaine type, alkylimidazolium betaine type, etc.) or nonionic (polyhydric alcohol derivative, β-cyclodextrin inclusion compound, sorbitan fatty acid monoester/diester, polyalkylene oxide derivative, amine oxide, etc.).

Examples of conductive polymers include polyaniline-based, polythiophene-based, polypyrrole-based, and polyquinoxaline-based polymers. Among these, polyaniline, polythiophene, and the like are preferably used. Polythiophene is particularly preferred.

Examples of conductive fine particles include metal oxides such as tin oxide, antimony oxide, indium oxide, and zinc oxide. Among these, the tin oxide type is preferable. Tin oxides include, in addition to tin oxide, antimony-doped tin oxide, indium-doped tin oxide, aluminum-doped tin oxide, tungsten-doped tin oxide, titanium oxide-cerium oxide-tin oxide composite, titanium oxide- Composites of tin oxide and the like can be mentioned. The fine particles have an average particle size of about 1 to 100 nm, preferably 2 to 50 nm.

Furthermore, as antistatic agents other than the above, acetylene black, ketjen black, natural graphite, artificial graphite, titanium black, cationic type (quaternary ammonium salt, etc.), amphoteric ion type (betaine compound, etc.), anionic type (sulfonic acid salts, etc.), homopolymers of monomers having nonionic (glycerin, etc.) ion-conductive groups or copolymers of the above monomers with other monomers, acrylates or methacrylates having a quaternary ammonium base Polymers having ionic conductivity such as polymers having sites of origin; and permanent antistatic agents of the type in which hydrophilic polymers such as polyethylene methacrylate copolymers are alloyed with acrylic resins or the like.

When the pressure-sensitive adhesive composition of the present invention contains other antistatic agents, the content is not particularly limited, but the transparency, appearance, and durability such as contact reliability of the pressure-sensitive adhesive layer of the present invention are ensured. From the point of view, it is preferably 1 part by weight or less, more preferably 0.5 parts by weight or less, 0.4 parts by weight or less, 0.3 parts by weight or less, or 0.3 part by weight or less with respect to 100 parts by weight of the acrylic polymer (A). 2 parts by weight or less. When the pressure-sensitive adhesive composition of the present invention contains other antistatic agents, the lower limit of the content is not particularly limited. Alternatively, it may be 0.05 parts by weight or more.

[2-11. Additive]
In the pressure-sensitive adhesive layer, if necessary, a cross-linking agent, a cross-linking accelerator, a silane coupling agent, a tackifying resin (rosin derivative, polyterpene resin, petroleum resin, oil-soluble phenol, etc.), an anti-aging agent, a filler, Known additives such as colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, chain transfer agents, plasticizers, softeners, surfactants, rust inhibitors, etc., within the range that does not impair the characteristics of the present invention. may be included in In addition, such an additive may be used individually or in combination of 2 or more types.

When the pressure-sensitive adhesive layer contains a cross-linking agent, the base polymer is cross-linked to increase the gel fraction, making it easier to improve the resistance to foaming and peeling. For example, the acrylic polymer (especially the acrylic polymer (A)) can be crosslinked to easily increase the control of the gel fraction. Also, the acrylic polymer (A) and the ionic compound of the present invention can form a covalent bond via a cross-linking agent.

Examples of the cross-linking agent include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, melamine-based cross-linking agents, peroxide-based cross-linking agents, urea-based cross-linking agents, metal alkoxide-based cross-linking agents, metal chelate-based cross-linking agents, metal Examples include salt-based cross-linking agents, carbodiimide-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, and amine-based cross-linking agents. Among them, when the pressure-sensitive adhesive layer is a pressure-sensitive adhesive layer containing an acrylic polymer (A) as a base polymer, isocyanate-based cross-linking agents and epoxy-based cross-linking agents are preferable and more preferable from the viewpoint of improving resistance to foaming and peeling. is an isocyanate cross-linking agent. In addition, a crosslinking agent may be used individually or in combination of 2 or more types.

Examples of the isocyanate-based crosslinking agent (polyfunctional isocyanate compound) include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; cyclopentylene diisocyanate; , cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate and other alicyclic polyisocyanates; 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate , xylylene diisocyanate and other aromatic polyisocyanates. Examples of the isocyanate-based cross-linking agent include trimethylolpropane/tolylene diisocyanate adduct [manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L"], trimethylolpropane/hexamethylene diisocyanate adduct [Nippon Polyurethane Kogyo Co., Ltd., trade name “Coronate HL”], trimethylolpropane/xylylene diisocyanate adduct [Mitsui Chemicals Co., Ltd., trade name “Takenate D-110N”].

Examples of the epoxy-based cross-linking agent (polyfunctional epoxy compound) include N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidyl aminomethyl)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 polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipate diglycidyl ester, o-phthalate diglycidyl ester, triglycidyl-tris(2 -hydroxyethyl)isocyanurate, resorcinol diglycidyl ether, bisphenol-S-diglycidyl ether, and epoxy resins having two or more epoxy groups in the molecule. Examples of the epoxy-based cross-linking agent include commercially available products such as those manufactured by Mitsubishi Gas Chemical Company, Inc. under the trade name of "Tetrad C".

The content of the cross-linking agent in the pressure-sensitive adhesive layer is not particularly limited. 5 parts by weight. When the content of the cross-linking agent is 0.001 parts by weight or more, the resistance to foaming and peeling is easily improved, which is preferable. On the other hand, when the content of the cross-linking agent is 10 parts by weight or less, the pressure-sensitive adhesive layer has appropriate flexibility and the pressure-sensitive adhesive strength is easily improved, which is preferable.

If the pressure-sensitive adhesive layer contains a silane coupling agent, excellent adhesion to glass (in particular, excellent adhesion reliability to glass at high temperature and high humidity) can be easily obtained, which is preferable. Examples of the silane coupling agent include, but are not limited to, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-aminopropyltrimethoxysilane. etc. Among them, γ-glycidoxypropyltrimethoxysilane is preferred. Furthermore, examples of the silane coupling agent include commercially available products such as the product name "KBM-403" (manufactured by Shin-Etsu Chemical Co., Ltd.). In addition, a silane coupling agent may be used individually or in combination of 2 or more types.

The content of the silane coupling agent in the adhesive layer is not particularly limited, but for example, when the adhesive layer is an adhesive layer containing an acrylic polymer (A) as a base polymer, the adhesion reliability to glass From the viewpoint of improving properties, it is preferably 0.01 to 1 part by weight, more preferably 0.03 to 0.5 part by weight, per 100 parts by weight of the acrylic polymer (A).

[2-12. Covalent bond]
The form of the reaction in which the acrylic polymer (A) and the functional group (A) of the ionic compound of the present invention form a covalent bond is not particularly limited as long as the covalent bond can be formed. For example, the functional group (A) may be incorporated as a monomer unit of the acrylic polymer (A), or the acrylic polymer (A) reacts with the functional group in the side chain to form a covalent bond. It may be in the form of forming. Furthermore, the acrylic polymer (A) and the functional group (A) of the ionic compound of the present invention may react via the above-mentioned cross-linking agent to form a covalent bond.

For example, the functional group (A) of the ionic compound of the present invention is a copolymerizable functional group such as (meth)acryloyloxy group, (meth)acryloylamino group, vinyl group, allyl group, styryl group, When it is contained in the mixture of monomer components constituting the acrylic polymer (A), it is incorporated as a monomer unit in the process of polymerizing the acrylic polymer (A) to form a covalent bond.

Further, the functional group (A) of the ionic compound of the present invention is a copolymerizable functional group such as (meth)acryloyloxy group, (meth)acryloylamino group, vinyl group, allyl group, styryl group, etc. When it is contained in the partially polymerized product of the mixture of the monomer components constituting the acrylic polymer (A), it undergoes living radical polymerization with the polymerized terminal radical of the partially polymerized product to form a covalent bond.

In addition, the functional group (A) of the ionic compound of the present invention is a hydroxyl group, an amino group, a mercapto group, etc., and the acrylic polymer (A) has an isocyanate group, a thioisocyanate group, an epoxy group, etc. in the side chain. When it has a functional group that can react with the functional group (A), or the functional group (A) is an epoxy group or the like, and the acrylic polymer (A) has a hydroxyl group, an amino group, a mercapto group, or the like in the side chain. When it has a functional group capable of reacting with the functional group (A) of, it reacts with the functional group (A) to form a covalent bond.

Furthermore, when the functional group (A) of the ionic compound of the present invention is a hydroxyl group, an amino group, a mercapto group, etc., and the acrylic polymer (A) has a hydroxyl group, an amino group, a mercapto group, etc. in the side chain. , The above-mentioned cross-linking agent is blended, and the functional group (A) and the side chain functional group of the acrylic polymer (A) react with the isocyanate group, thioisocyanate group, epoxy group, etc. of the cross-linking agent, and through the cross-linking agent can form a covalent bond.

In addition to the base material of the present invention and the pressure-sensitive adhesive layer of the present invention, the optical pressure-sensitive adhesive sheet of the present invention includes other layers, for example, a base material other than the base material of the present invention, as long as the effects of the present invention are not impaired. , a pressure-sensitive adhesive layer other than the pressure-sensitive adhesive layer of the present invention, an intermediate layer, an undercoat layer (anchor layer), a separator, a surface protective film, and the like on the surface or between any layers.

[3. Undercoat layer (anchor layer)]
From the viewpoint of adhesion, an undercoat layer (anchor layer) may be provided between the first surface of the base material of the present invention and the pressure-sensitive adhesive layer of the present invention.
The thickness of the anchor layer is 0.01 to 0.5 μm, preferably 0.01 to 0.4 μm, more preferably 0.02 to 0.3 μm, from the viewpoint of adhesion with the pressure-sensitive adhesive layer. It is preferable to have

As the material for forming the anchor layer, a binder component can be added for the purpose of improving the film-forming property and adhesion to the base material of the present invention. Examples of binders include oxazoline group-containing polymers, polyurethane resins, polyester resins, acrylic resins, polyether resins, cellulose resins, polyvinyl alcohol resins, epoxy resins, polyvinylpyrrolidone, polystyrene resins, polyethylene glycol, pentaerythritol and the like. Polyurethane-based resins, polyester-based resins, and acrylic-based resins are particularly preferred. One or more of these binders can be used as appropriate depending on the application.

The anchor layer may have conductivity (antistatic property). By making the anchor layer conductive (antistatic), the antistatic function is excellent compared to the case where the adhesive layer alone imparts antistatic properties, and the amount of antistatic agent used in the adhesive layer can be suppressed to a small amount, and this is a preferable embodiment from the viewpoint of durability and appearance defects such as precipitation and segregation of the antistatic agent and cloudiness under a humidified environment. When the anchor layer has antistatic properties, the surface resistance thereof is preferably 1.0×10 ⁸ to 1.0×10 ¹⁰ Ω/□, more preferably 1.0×10 ⁸ to 8.0×10 Ω/□. ⁹ Ω/□ is more preferable, and 2.0×10 ⁸ to 6.0×10 ⁹ Ω/□ is even more preferable.

When the anchor layer has antistatic properties, the antistatic properties can be imparted by including a conductive polymer in the binder component. The conductive polymer is preferably used from the viewpoint of optical properties, appearance, antistatic effect, and stability of the antistatic effect when heated and when humidified. In particular, conductive polymers such as polyaniline and polythiophene are preferably used. An organic solvent-soluble, water-soluble, or water-dispersible conductive polymer can be appropriately used, but a water-soluble conductive polymer or a water-dispersible conductive polymer is preferably used. A water-soluble conductive polymer or a water-dispersible conductive polymer can be prepared as an aqueous solution or an aqueous dispersion when forming an antistatic layer, and the coating solution does not need to use a non-aqueous organic solvent, and the organic This is because deterioration of the optical film substrate due to the solvent can be suppressed. The aqueous solution or aqueous dispersion can contain an aqueous solvent in addition to water. For example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol, 1-ethyl-1 -propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol and other alcohols.

In addition, the water-soluble conductive polymer or water-dispersible conductive polymer such as polyaniline and polythiophene preferably has a hydrophilic functional group in the molecule. Hydrophilic functional groups include, for example, a sulfone group, an amino group, an amide group, an imino group, a quaternary ammonium base, a hydroxyl group, a mercapto group, a hydrazino group, a carboxyl group, a sulfate group, a phosphate group, or salts thereof. etc. Having a hydrophilic functional group in the molecule makes it easier to dissolve in water or easier to disperse in water in the form of fine particles, making it possible to easily prepare the water-soluble conductive polymer or water-dispersible conductive polymer. In addition, when using a polythiophene-based polymer, polystyrene sulfonic acid is usually used together.

The anchor layer can be formed, for example, by coating the first surface of the substrate of the present invention with a conductive coating liquid obtained by blending a conductive polymer with the above binder component, if necessary. Specific coating methods include a roll coating method, a bar coating method, a gravure coating method, and the like.

[4. Separator (release liner)]
In the optical pressure-sensitive adhesive sheet of the present invention, the surface of the pressure-sensitive adhesive layer of the present invention (adhesive surface of the pressure-sensitive adhesive layer of the present invention) may be protected by a separator until use. The separator is used as a protective material for the pressure-sensitive adhesive layer, and is peeled off when the optical pressure-sensitive adhesive sheet of the present invention is attached to an adherend. Note that the separator does not necessarily have to be provided.

As the separator, a conventional release paper or the like can be used. Specifically, for example, in addition to a substrate having a release treatment layer with a release treatment agent on at least one surface, a fluorine-based polymer (e.g., polytetrafluoroethylene) , polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, etc.). A low-adhesive base material made of (for example, olefin resin such as polyethylene, polypropylene, etc.) can be used.

As the separator, for example, a separator in which a release treatment layer is formed on at least one surface of a separator substrate can be suitably used. Base materials for such separators include polyester film (polyethylene terephthalate film, etc.), olefin resin film (polyethylene film, polypropylene film, etc.), polyvinyl chloride film, polyimide film, polyamide film (nylon film), rayon film, etc. In addition to the plastic base film (synthetic resin film) and paper (wooden paper, Japanese paper, kraft paper, glassine paper, synthetic paper, top coat paper, etc.), these are multi-layered by lamination or co-extrusion. (composite of 2 to 3 layers) and the like.

The release treatment agent that constitutes the release treatment layer is not particularly limited, but for example, a silicone-based release treatment agent, a fluorine-based release treatment agent, a long-chain alkyl-based release treatment agent, or the like can be used. The release agents can be used alone or in combination of two or more.

The thickness of the separator is not particularly limited, and may be appropriately selected from the range of 5 to 100 μm.

The above separator may have an antistatic layer formed on at least one surface of the separator substrate in order to prevent damage to an adherend such as an image display panel. The antistatic layer may be formed on one surface of the separator (release-treated surface or untreated surface) or may be formed on both surfaces of the separator (release-treated surface and untreated surface).

The antistatic layer is not particularly limited, but is, for example, an antistatic layer formed by coating a separator with a conductive coating liquid containing a conductive polymer. Specifically, for example, it is an antistatic layer formed by coating a separator (release-treated surface and/or untreated surface) with a conductive coating liquid containing a conductive polymer. Specific coating methods include a roll coating method, a bar coating method, a gravure coating method, and the like.

As the conductive polymer, the same conductive polymer that constitutes the antistatic agent that may be contained in the optical pressure-sensitive adhesive sheet of the present invention can be used.

The thickness of the antistatic layer is preferably 1 nm to 1000 nm, more preferably 5 nm to 900 nm. The antistatic layer may consist of only one layer, or may consist of two or more layers.

[5. Manufacturing method of optical pressure-sensitive adhesive sheet]
The optical pressure-sensitive adhesive sheet of the present invention can be prepared by laminating the pressure-sensitive adhesive layer of the present invention on the first surface of the substrate of the present invention.

The method for laminating the pressure-sensitive adhesive layer of the present invention on the first surface of the base material of the present invention is not particularly limited. By drying and curing the adhesive composition layer, or by applying (coating) the adhesive composition on the separator and curing the obtained adhesive composition layer by irradiating it with an active energy ray, on the separator It can be carried out by molding into a sheet-like pressure-sensitive adhesive layer, and bonding the pressure-sensitive adhesive layer on the first surface of the substrate of the present invention. Moreover, you may heat-dry further as needed.
When curing by irradiation with active energy rays, a separator is further attached to the surface of the coating film, and the adhesive composition is sandwiched between two separators and irradiated with active energy rays to polymerize with oxygen. It is preferred to prevent inhibition.

Another method for laminating the pressure-sensitive adhesive layer of the present invention on the first surface of the substrate of the present invention is, for example, applying (coating) the above-mentioned pressure-sensitive adhesive composition onto the first surface of the substrate of the present invention. , drying and curing the obtained pressure-sensitive adhesive composition layer, or applying (coating) the above-mentioned pressure-sensitive adhesive composition on the first surface of the substrate of the present invention, and applying an active agent to the obtained pressure-sensitive adhesive composition layer. It can also be cured by irradiation with energy rays. Moreover, you may heat-dry further as needed.
When curing by irradiation with active energy rays, a separator is attached to the surface of the coating film, and the adhesive composition is irradiated with active energy rays while being sandwiched between the base material of the present invention and the separator. It is preferable to prevent polymerization inhibition by oxygen.

The sheet-like coating film may be heated for the purpose of removing the solvent, etc., before the active energy ray irradiation. If the solvent or the like is removed by heating, it is preferably carried out before attaching the separator.

Examples of the active energy rays include ionizing radiation such as α-rays, β-rays, γ-rays, neutron beams and electron beams, and ultraviolet rays, with ultraviolet rays being particularly preferred. Moreover, the irradiation energy of the active energy ray, the irradiation time, the irradiation method, etc. are not particularly limited.

The above pressure-sensitive adhesive composition can be produced by a known or commonly used method. For example, a solvent-based acrylic pressure-sensitive adhesive composition can be prepared by mixing additives, if necessary, with a solution containing the acrylic polymer (A) and the ionic compound of the present invention. . For example, an active energy ray-curable acrylic pressure-sensitive adhesive composition can be prepared by mixing the mixture of the acrylic monomer (A) or a partial polymer thereof and the ionic compound of the present invention with additives, if necessary. can be produced by

A known coating method may be used for applying (coating) the pressure-sensitive adhesive composition. For example, coaters such as gravure roll coaters, reverse roll coaters, kiss roll coaters, dip roll coaters, bar coaters, knife coaters, spray coaters, comma coaters, and direct coaters may be used.

In particular, when the adhesive layer is formed from an active energy ray-curable adhesive composition, the active energy ray-curable adhesive composition preferably contains a photopolymerization initiator. When the active energy ray-curable pressure-sensitive adhesive composition contains an ultraviolet absorber, it preferably contains at least a photopolymerization initiator having light absorption properties in a wide wavelength range as a photopolymerization initiator. For example, it preferably contains at least a photopolymerization initiator that absorbs not only ultraviolet light but also visible light. This is because there is concern that curing by active energy rays may be inhibited due to the action of the ultraviolet absorber, and if the adhesive composition contains a photopolymerization initiator that has light absorption characteristics in a wide wavelength range, high photocurability will be achieved in the adhesive composition. This is because it becomes easier to obtain.

[6. Applications, etc. of Optical Adhesive Sheets]
Since the optical pressure-sensitive adhesive sheet of the present invention has the pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention), it has excellent antistatic performance. Therefore, display defects due to static electricity are less likely to occur when used for lamination with an optical member or an image display device. In addition, since bleeding out of the antistatic component can be suppressed even under harsh conditions such as a moist and hot environment, precipitation, foaming, and peeling on the surface of the adhesive layer are suppressed, and appearance and adhesion reliability are improved. Poor durability is less likely to occur. Therefore, the optical pressure-sensitive adhesive sheet of the present invention satisfies excellent antistatic properties, transparency, moist heat resistance, and low staining properties, and is useful for the production of image display devices.

Furthermore, the optical pressure-sensitive adhesive sheet of the present invention is excellent in adhesiveness, resistance to foaming and peeling, and stress relaxation, as well as step followability and adhesion reliability, especially at high temperatures. Moreover, it is excellent in external appearance. Therefore, the optical pressure-sensitive adhesive sheet of the present invention is useful for adherends that tend to foam at the interface at high temperatures. For example, polymethyl methacrylate (PMMA) may contain unreacted monomers, and foaming due to foreign matter is likely to occur at high temperatures. Polycarbonate (PC) also tends to outgas water and carbon dioxide at high temperatures. Since the pressure-sensitive adhesive sheet of the present invention is excellent in resistance to foaming and peeling, it is also useful for plastic adherends containing such resins.

Moreover, the optical pressure-sensitive adhesive sheet of the present invention is useful not only for adherends with a small coefficient of linear expansion, but also for adherends with a large coefficient of linear expansion. The ^adherend ^having a small coefficient of linear expansion is not particularly limited. material (PET film, coefficient of linear expansion: 1.5×10 ⁻⁵ to 2×10 ⁻⁵ /° C.). The adherend having a large coefficient of linear expansion is not particularly limited, but examples thereof include resin substrates having a large coefficient of linear expansion. 7×10 ⁻⁵ to 8×10 ⁻⁵ /° C.), polymethyl methacrylate resin substrate (PMMA, linear expansion coefficient: 7×10 ⁻⁵ to 8×10 ⁻⁵ /° C.), cycloolefin polymer substrate ( COP, linear expansion coefficient: 6×10 ⁻⁵ to 7×10 ⁻⁵ /° C.), trade name “Zeonor” (manufactured by Nippon Zeon Co., Ltd.), trade name “Arton” (manufactured by JSR Corporation), and the like.

Thus, the optical pressure-sensitive adhesive sheet of the present invention is useful for lamination with adherends made of various materials, and is particularly useful for lamination with glass adherends and plastic adherends. The plastic adherend may be an optical film such as a plastic film having an ITO (indium tin oxide) layer on its surface.

Furthermore, the optical pressure-sensitive adhesive sheet of the present invention is useful not only for adherends with smooth surfaces, but also for adherends with uneven surfaces. In particular, in the optical pressure-sensitive adhesive sheet of the present invention, even if at least one of the glass adherend and the resin substrate having a large coefficient of linear expansion has steps on the surface, the glass adherend and the linear expansion coefficient It is useful for bonding with a resin base material having a large modulus.

The optical pressure-sensitive adhesive sheet of the present invention is preferably used for manufacturing portable electronic devices. Examples of the portable electronic devices include mobile phones, PHS, smartphones, tablets (tablet computers), mobile computers (mobile PCs), personal digital assistants (PDA), electronic notebooks, portable televisions, portable radios, and the like. type broadcast receivers, portable game machines, portable audio players, portable DVD players, cameras such as digital cameras, and camcorder type video cameras.

[7. Optical laminate]
The optical laminate of the present invention has a laminate structure in which the optical pressure-sensitive adhesive sheet of the present invention and an optical member are laminated. In FIG. 2, the optical layered body 20 has an optical member 5 laminated on the pressure-sensitive adhesive layer 2 of the optical pressure-sensitive adhesive sheet 10 .
Since the optical layered body of the present invention has the pressure-sensitive adhesive layer (the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention), it has excellent antistatic performance. Therefore, static electricity is less likely to occur when used to bond another optical member. In addition, since bleeding out of the antistatic component can be suppressed even under harsh conditions such as moist and hot environments, precipitation, foaming, and peeling on the surface of the adhesive layer are suppressed, and durability such as appearance and adhesion reliability is improved. defects are less likely to occur. Therefore, the optical laminate of the present invention can satisfy excellent antistatic properties, transparency, moist heat resistance, and low staining properties.

An optical member refers to a member having optical properties (e.g., polarization, light refraction, light scattering, light reflection, light transmission, light absorption, light diffraction, optical rotation, visibility, etc.). . The substrate constituting the optical member is not particularly limited. For example, polarizing plate, wave plate, retardation plate, optical compensation film, brightness enhancement film, light guide plate, reflective film, antireflection film, hard coat film (hard coat treatment is applied to at least one side of plastic film such as PET film). films), transparent conductive films (for example, plastic films having an ITO layer on the surface (preferably ITO films such as PET-ITO, polycarbonate, cycloolefin polymer, etc.), design films, decorative films, surface protection plates, prisms , lenses, color filters, transparent substrates (glass sensors, glass display panels (LCD, etc.), glass substrates such as glass plates with transparent electrodes, etc.), and substrates on which these are laminated (these are collectively referred to as " may be referred to as "functional film") and the like. Moreover, these films may have a metal nanowire layer, a conductive polymer layer, or the like. Further, these films may be mesh-printed with thin metal wires. The above-mentioned "plate" and "film" include forms such as plate-like, film-like, and sheet-like, respectively. For example, "polarizing film" includes "polarizing plate" and "polarizing sheet". . In addition, "film" shall include film sensors and the like.

Examples of the display device include a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (plasma display panel), electronic paper, and the like. Moreover, a touch panel etc. are mentioned as said input device.

The substrate constituting the optical member is not particularly limited. etc.). As described above, the "optical member" in the present invention includes members (design films, decorative films, surface protective films, etc.) that play a role of decoration and protection while maintaining the visibility of display devices and input devices. shall be taken.

The optical member is preferably transparent. The total light transmittance (according to JIS K7361-1) of the optical member in the visible light wavelength region is not particularly limited, but is preferably 85% or more, more preferably 88% or more. In addition, the haze (according to JIS K7136) of the optical member is not particularly limited, but is preferably 1.0% or less, more preferably 0.8% or less. Examples of such transparent substrates include PET films and non-oriented films such as the trade name "Arton" and the trade name "Zeonor".

Although the thickness of the optical member is not particularly limited, it is preferably 12 to 500 μm, for example. The optical member may have either a single-layer structure or a multilayer structure. Further, the surface of the optical member may be appropriately subjected to a known and commonly used surface treatment such as physical treatment such as corona discharge treatment and plasma treatment, and chemical treatment such as undercoating treatment.

The optical laminate of the present invention can be produced by laminating the optical member and the pressure-sensitive adhesive layer of the optical pressure-sensitive adhesive sheet of the present invention.

Specifically, the optical member and the optical pressure-sensitive adhesive sheet of the present invention can be attached by laminating them under heat and/or pressure. Curing may be performed by irradiating active energy rays after lamination under heat and/or pressure. Irradiation with active energy rays can be performed in the same manner as in the formation of the pressure-sensitive adhesive layer of the present invention.

[8. Image display device]
The image display device of the present invention has a laminate structure in which the optical pressure-sensitive adhesive sheet of the present invention and an image display panel are laminated. In FIG. 3, the image display device 30 has an image display panel 6 laminated on the adhesive layer 1 of the optical adhesive sheet 10 .
Since the image display device of the present invention has the optical pressure-sensitive adhesive sheet of the present invention having excellent antistatic performance in the laminated structure, display defects due to static electricity are less likely to occur. In addition, since it is possible to suppress bleeding out of the antistatic component even under harsh conditions such as a moist and hot environment, precipitation, foaming, and peeling on the surface of the adhesive layer are suppressed, and appearance and adhesion reliability are improved. Poor durability is less likely to occur. Therefore, the image display device of the present invention can satisfy excellent antistatic properties, transparency, moist heat resistance, and low staining properties.

In addition, the pressure-sensitive adhesive layer of the present invention sufficiently follows the contraction or expansion of the image display device, and is less likely to lift or peel off. Furthermore, when the image display panel has uneven steps due to wiring or the like, the pressure-sensitive adhesive layer of the present invention can sufficiently follow the steps and can be filled without leaving air bubbles.

The image display panel is not particularly limited, but includes, for example, a liquid crystal image display panel, a self-luminous image display panel (eg, an organic EL (electroluminescence) image display panel, an LED image display panel), and the like.

The image display panel is formed by alternately arranging RGB elements, and in order to improve the contrast, it is preferable that the spaces between the RGB elements be filled with a black matrix (BM).

The image display device of the present invention may include an optical member other than the optical pressure-sensitive adhesive sheet of the present invention and the image display panel on the surface or between any layers. Examples of the optical member include, but are not particularly limited to, a polarizing plate, a retardation plate, an antireflection film, a viewing angle adjusting film, and an optical compensation film. Note that the optical member includes members (design film, decorative film, surface protection plate, etc.) that play a role of decoration and protection while maintaining the visibility of the image display device and the input device.

The image display device of the present invention can be manufactured by laminating the image display panel and the pressure-sensitive adhesive layer of the optical pressure-sensitive adhesive sheet of the present invention.

Specifically, the image display panel and the optical pressure-sensitive adhesive sheet of the present invention can be attached by laminating them under heat and/or pressure. Curing may be performed by irradiating active energy rays after lamination under heat and/or pressure. Irradiation with active energy rays can be performed in the same manner as in the formation of the pressure-sensitive adhesive layer of the present invention.

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

Production example 1
(Preparation of antiglare film 1)
[Preparation of coating solution for forming antiglare layer 1]
As the resin contained in the antiglare layer forming material, 40 parts by weight of an ultraviolet curable urethane acrylate resin (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name “NK Oligo UA-53H-80BK”) A diluted solution of a composition for an optical adjustment layer containing 57.5 parts by weight of a functional acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #300"), zirconia particles, and an ultraviolet curable resin ("OPSTAR Z7540 ”, manufactured by JSR), 2.5 parts by weight of silicone particles (Momentive Performance Materials Japan LLC, trade name “Tospearl 130ND”, and 2.8 parts by weight of organic clay as a thixotropy-imparting agent. 2.5 parts by weight of smectite (manufactured by Kunimine Industries Co., Ltd., trade name "Smecton SAN") and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907"), fine particles of crosslinked acrylic styrene copolymer resin (trade name “SSX-103DXE” manufactured by Sekisui Plastics Co., Ltd.) was mixed with 6.5 parts by weight of a leveling agent (trade name “LE-303” manufactured by Kyoeisha Chemical Co., Ltd.) and 0.1 part by weight. , The organoclay was diluted with toluene so that the solid content was 6% by weight.This mixture was added to a toluene/cyclopentanone (CPN) mixed solvent ( (weight ratio: 64/36) to prepare an antiglare layer-forming material (coating liquid) using an ultrasonic disperser.

[Formation of antiglare layer 1]
As a substrate, a transparent plastic film substrate (PET film, manufactured by Toray Industries, Inc., trade name “38U413”, thickness: 38 μm) was prepared. The antiglare layer-forming material (coating solution) was applied to one side of the transparent plastic film substrate using a wire bar to form a coating film (coating step). Then, the coating film was dried by heating at 95° C. for 1 minute (drying step). After that, the coating film was cured by irradiating ultraviolet light with an accumulated light amount of 300 mJ/cm ² with a high-pressure mercury lamp to form an antiglare layer having a thickness of 6.5 μm. Thus, a laminate of the light transmissive substrate and the antiglare layer 1 was obtained.

[Preparation of coating solution for forming antireflection layer 1]
100 parts by weight of polyfunctional acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name “Viscoat #300”) mainly composed of pentaerythritol triacrylate, and hollow nano silica particles (manufactured by Nikki Shokubai Kasei Kogyo Co., Ltd., trade name “Sururia 5320") 100 parts by weight, solid nanosilica particles (manufactured by Nissan Chemical Industries, Ltd., trade name "MIBK-ST", solid content 30% by weight, weight average particle diameter 10 nm) 40 parts by weight, fluorine element-containing additive (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KY-1203") 12 parts by weight, a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907") 5 parts by weight, a photopolymerization initiator (manufactured by BASF, Trade name "OMNIRAD2959") was mixed with 5 parts by weight. To this mixture, a mixed solvent of MIBK (methyl isobutyl ketone) and PMA (propylene glycol monomethyl ether acetate) mixed at a weight ratio of 70:30 was added as a dilution solvent so that the total solid content was 1.5% by weight. and stirred to prepare a coating solution for forming an antireflection layer.
[Formation of antireflection layer 1]
The antireflection layer-forming coating liquid was applied to the antiglare layer surface of the laminate of the light transmissive substrate and the antiglare layer 1 with a wire bar (coating step). The applied coating liquid was heated at 80° C. for 1 minute and dried to form a coating film (drying step). After drying, the coating film was cured by irradiating ultraviolet light with an accumulated light amount of 300 mJ/cm ² from a high-pressure mercury lamp (curing step). Thereby, the coating film was cured to form an antireflection layer having a thickness of 0.1 μm (antireflection layer forming step). Antiglare film 1 of Production Example 1 was produced as described above.

Production Example 2: Production of PSA Sheet A As a monomer mixture, 58 parts by weight of butyl acrylate (BA), 23 parts by weight of 4-hydroxybutyl acrylate (4HBA), 7 parts by weight of 2-hydroxyethyl acrylate (HEA), and 12 parts by weight of cyclohexyl acrylate (CHA), 0.05 parts by weight of a photopolymerization initiator (trade name "Omnirad 184", manufactured by IGM Resins B.V.), and a photopolymerization initiator (trade name Name "Omnirad 651", manufactured by IGM Resins B.V.) After blending 0.05 parts by weight, the viscosity (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30 ° C.) was about 20 Pa s. A prepolymer composition in which a part of the monomer component was polymerized was obtained by irradiating with ultraviolet rays until the temperature reached 100%.
Next, 0.025 parts by weight of dipentaerythritol hexaacrylate (DPHA) and a quaternary ammonium salt (2-acryloyloxyethyl)trimethylammonium having an acroyl group as a reactive functional group are added to 100 parts by weight of the prepolymer composition. =Bis(trifluoromethanesulfonyl)imide) (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.: CAS RN.827027-31-6) was added and mixed to obtain an acrylic pressure-sensitive adhesive composition. The above acrylic pressure-sensitive adhesive composition is applied onto the release-treated surface of a release film (trade name “MRF #38”, manufactured by Mitsubishi Plastics, Inc.) so that the thickness after forming the pressure-sensitive adhesive layer is 20 μm. Then, a release film (trade name: "MRN#38", manufactured by Mitsubishi Plastics, Inc.) was attached to the surface of the adhesive composition layer. After that, ultraviolet irradiation is performed under the conditions of illuminance: 5 mW/cm ² and light amount: 1500 mJ/cm ² , and the adhesive composition layer is photocured to consist of only the adhesive layer, and both sides of the adhesive layer are protected by separators. A substrate-less double-sided pressure-sensitive adhesive sheet A was formed.

Production Example 3: Preparation of Adhesive Sheet B Quaternary ammonium salt having an acroyl group as a reactive functional group (2-acryloyloxyethyl) trimethylammonium = bis (trifluoromethanesulfonyl) imide) (Fujifilm Wako Pure Chemical Industries, Ltd.) CAS RN.827027-31-6) was added in 15 parts by weight and applied so that the thickness after forming the adhesive layer was 50 μm. formed B.

Production Example 4: Preparation of Adhesive Sheet C Quaternary ammonium salt having an acroyl group as a reactive functional group (2-acryloyloxyethyl) trimethylammonium = bis (trifluoromethanesulfonyl) imide) (Fujifilm Wako Pure Chemical Industries, Ltd.) CAS RN.827027-31-6) was added in 20 parts by weight, and the pressure-sensitive adhesive sheet was prepared in the same manner as for pressure-sensitive adhesive sheet A, except that the adhesive layer was coated so that the thickness after forming the pressure-sensitive adhesive layer was 50 μm. formed C.

Production Example 5: Preparation of Adhesive Sheet D Quaternary ammonium salt having an acroyl group as a reactive functional group (2-acryloyloxyethyl) trimethylammonium = bis (trifluoromethanesulfonyl) imide) (Fujifilm Wako Pure Chemical Industries, Ltd.) CAS RN.827027-31-6) was added in 15 parts by weight, and the pressure-sensitive adhesive sheet was prepared in the same manner as for pressure-sensitive adhesive sheet A except that the adhesive layer was coated so that the thickness after forming the pressure-sensitive adhesive layer was 100 μm. formed D.

Production Example 6: Preparation of Adhesive Sheet E Quaternary ammonium salt having an acroyl group as a reactive functional group (2-acryloyloxyethyl) trimethylammonium = bis (trifluoromethanesulfonyl) imide) (Fujifilm Wako Pure Chemical Industries, Ltd.) CAS RN.827027-31-6) instead of quaternary ammonium salt having a methacryloyl group as a reactive functional group (2-methacryloyloxyethyl) trimethylammonium = bis (trifluoromethanesulfonyl) imide) (Fuji Film Wada Kojunyaku Co., Ltd.: CAS RN.676257-10-6) was added in the same manner as in Adhesive Sheet A, except that 15 parts by weight was added and the adhesive layer was applied so that the thickness after forming the adhesive layer was 50 μm. to form an adhesive sheet E.

Comparative Production Example 1: Preparation of Adhesive Sheet F Quaternary ammonium salt having an acroyl group as a reactive functional group (2-acryloyloxyethyl) trimethylammonium = bis (trifluoromethanesulfonyl) imide) (Fujifilm Wako Pure Chemical Industries, Ltd. ) manufactured by: CAS RN.827027-31-6) was formed in the same manner as the adhesive sheet A, except that the adhesive sheet F was formed.

Comparative Production Example 2: Preparation of Adhesive Sheet G Quaternary ammonium salt having an acroyl group as a reactive functional group (2-acryloyloxyethyl) trimethylammonium = bis (trifluoromethanesulfonyl) imide) (Fujifilm Wako Pure Chemical Industries, Ltd. ) manufactured by: CAS RN.827027-31-6) instead of 1-ethyl-1-methylpyrrolidium=bis(trifluoromethanesulfonyl)imide (manufactured by Kanto Chemical Co., Ltd.: CAS RN.223436-99-5) A pressure-sensitive adhesive sheet G was formed in the same manner as the pressure-sensitive adhesive sheet A, except that 15 parts by weight of was added.

The following evaluations were performed using the pressure-sensitive adhesive sheets obtained in Production Examples 2-6 and Comparative Production Examples 1-2 above.

<Evaluation of total light transmittance and haze>
One separator was peeled off from the pressure-sensitive adhesive sheets obtained in Production Examples 2-6 and Comparative Production Examples 1-2, and the double-sided pressure-sensitive adhesive sheet was applied to a slide glass (manufactured by Matsunami Glass Industry Co., Ltd., "White polishing No. 1". , thickness 0.8 to 1.0 mm, total light transmittance 92%, haze 0.2%), and the other separator is peeled off, double-sided adhesive sheet (adhesive layer) / slide glass layer Test specimens having configurations were prepared. The total light transmittance and haze in the visible light region of the test piece were measured using a haze meter (apparatus name "HM-150N", manufactured by Murakami Color Research Institute). The measurement results are shown in Table 2.

<Evaluation of adhesive strength to glass>
The pressure-sensitive adhesive sheets obtained in Production Examples 2-6 and Comparative Production Examples 1-2 were cut into a width of 100 mm and a length of 100 mm. : Lumirror S-10, thickness: 25 μm, manufactured by Toray Industries, Inc.) was attached (backed). Next, the other release film was peeled off, and it was laminated to a glass plate (trade name: soda lime glass #0050, manufactured by Matsunami Glass Industry Co., Ltd.) as a test plate, and laminated under the conditions of one reciprocating pressure bonding with a 2 kg roller. , a sample composed of a test plate/adhesive layer/PET film was prepared.
(initial adhesive strength)
After sample preparation, after aging for 30 minutes in an atmosphere of 23 ° C. and 50% RH, in accordance with JIS Z0237, in an atmosphere of 23 ° C. and 50% RH, a tensile tester (device name: Autograph AG-IS, (manufactured by Shimadzu Corporation), the adhesive sheet (adhesive layer/PET film) was peeled off from the test plate under the conditions of a tensile speed of 300 mm / min and a peeling angle of 180 °, and 180 ° peeling adhesive strength (initial adhesion force) (N/20 mm) was measured.
(Paste storage adhesive strength)
After sample preparation, after aging for 240 hours in an atmosphere of 23 ° C. and 50% RH, in accordance with JIS Z0237, under an atmosphere of 23 ° C. and 50% RH, a tensile tester (device name: Autograph AG-IS (manufactured by Shimadzu Corporation), the adhesive sheet (adhesive layer/PET film) was peeled off from the test plate under the conditions of a tensile speed of 300 mm / min and a peeling angle of 180 °, and 180 ° peeling adhesive strength (sticking After 240 hours of storage, the adhesive strength) (N/20 mm) was measured.
For the measurement, three samples were prepared for each condition and their numerical average was taken. The measurement results are shown in Table 2.

<Surface resistivity (Ω/□): antistatic property>
After peeling off the separator film on one side of the pressure-sensitive adhesive sheets obtained in Production Examples 2-6 and Comparative Production Examples 1-2, the surface resistivity (R0) of the surface of the pressure-sensitive adhesive layer was measured. The measurement was performed in an atmosphere of 23° C. and 50% RH using MCP-HT450 manufactured by Mitsubishi Chemical Analytic Tech. The measurement results are shown in Table 2.

<Appearance: Stored at normal temperature, after moist heat test>
The pressure-sensitive adhesive sheets (structure of separator/adhesive/separator) obtained in Production Examples 2-6 and Comparative Production Examples 1-2 were cut into pieces of 15×15 cm and stored in an environment of 23° C. and 50% RH for 7 days. The appearance of the pressure-sensitive adhesive sheet was visually confirmed and evaluated according to the following evaluation criteria. The measurement results are shown in Table 2.
(Evaluation criteria)
〇 No optical defects such as white turbidity observed × Patchy whitening/bleed-out observed on the adhesive

Next, one separator is peeled off from the pressure-sensitive adhesive sheets obtained in Production Examples 2-6 and Comparative Production Examples 1-2, and the double-sided pressure-sensitive adhesive sheet is applied to a slide glass (manufactured by Matsunami Glass Industry Co., Ltd., "White polishing No. .1”, thickness 0.8 to 1.0 mm, total light transmittance 92%, haze 0.2%), and a test having a layer configuration of separator / double-sided adhesive sheet (adhesive layer) / slide glass A piece was made. Put in an atmosphere of 85 ° C. and 85% RH for 240 hours, take out to room temperature, adjust temperature and humidity for 24 hours in an environment of 23 ° C. and 50% RH, then peel off the separator and use a double-sided adhesive sheet ( Adhesive layer)/slide glass layer structure was measured using a haze meter (apparatus name "HM-150N", manufactured by Murakami Color Laboratory Co., Ltd.) and evaluated according to the following evaluation criteria. The measurement results are shown in Table 2.
(Evaluation criteria)
○: Haze of 1.0 or less, particularly good △: Haze of more than 1.0 to 2.0 or less, good ×: Haze of more than 2.0, practically problematic level

<Wet heat stability evaluation of surface resistivity (Ω/□)>
The pressure-sensitive adhesive sheets (separator film/adhesive layer/separator film) obtained in Production Examples 4 and 6 and Comparative Production Example 2 were cut into 100 mm squares, and after peeling off the separator film on one side, the surface resistance of the pressure-sensitive adhesive layer surface was measured. The rate (R0) was measured. The measurement was performed in an atmosphere of 23° C. and 50% RH using MCP-HT450 manufactured by Mitsubishi Chemical Analytic Tech. Three samples were prepared and measured for each condition, and their numerical averages were taken. After the measurement, the separator film was reattached, and then placed in an environment of 60° C. and 95% RH for 240 hours. After taking it out, the temperature and humidity were adjusted for 24 hours in an environment of 23°C and 50% RH, then the separator film on one side was peeled off, and the surface resistivity (R1) of the adhesive layer surface after the wet heat test was measured. and a numerical average of three samples was taken. Based on the measurement results, evaluation was made according to the following evaluation criteria. The measurement results are shown in Table 3.
(Evaluation criteria)
○: Surface resistance value after wet heat test (R1) / Surface resistance value before wet heat test (R0) ≤ 20
△: 20<Surface resistance value after wet heat test (R1) / Surface resistance value before wet heat test (R0) ≤ 100
×: 100<Surface resistance value after wet heat test (R1) / Surface resistance value before wet heat test (R0)

Example 1 Preparation of Optical Adhesive Sheet A One release film was peeled off from the adhesive sheet A obtained in Production Example 2 above, and the exposed adhesive surface was coated with the antiglare film 1 shown in Production Example 1. Optical adhesive sheet A consisting of antiglare film 1/adhesive layer/release film was obtained by attaching to the non-antiglare layer surface of .

Example 2: Preparation of optical adhesive sheet B The adhesive surface exposed by peeling one release film from the adhesive sheet C obtained in Production Example 4 above was coated with an antireflection film (TAC film; Dai Nippon Printing ( Co., Ltd.; product name “DSG-17V1”; substrate thickness: 60 μm; total thickness: 70 μm). An adhesive sheet B was obtained.

The following evaluations were performed using the optical pressure-sensitive adhesive sheets obtained in Examples 1 and 2 above.

<Evaluation of Haze>
The optical pressure-sensitive adhesive sheets obtained in Examples 1 and 2 were measured at room temperature (23° C.) using a haze measuring device (HR-100 manufactured by Murakami Color Laboratory). Measurement was repeated 3 times, and the average value was used as the measured value. The measurement results are shown in Table 3.

<Evaluation of reflectance>
The adhesive surface of the optical pressure-sensitive adhesive sheet obtained in Examples 1 and 2 was attached to a black acrylic plate to prepare a test piece. The obtained test piece was placed in a spectrophotometer U4100 (manufactured by Hitachi High-Technology Co., Ltd.) with the pressure-sensitive adhesive layer side facing the light source side, and the reflectance (%) of the visible light region of 5° specular reflection was measured. The measurement results are shown in Table 3.

<Surface resistivity (Ω/□): antistatic property>
After peeling off the separator film of the optical pressure-sensitive adhesive sheets obtained in Examples 1 and 2, the surface resistivity (R0) of the surface of the pressure-sensitive adhesive layer was measured. The measurement was performed in an atmosphere of 23° C. and 50% RH using MCP-HT450 manufactured by Mitsubishi Chemical Analytic Tech. The measurement results are shown in Table 4.

Variations of the present invention are described below.
[Appendix 1] An optical pressure-sensitive adhesive sheet having a laminated structure in which a substrate having a first surface and a second surface and an adhesive layer is laminated on the first surface of the substrate,
A pressure-sensitive adhesive composition in which the pressure-sensitive adhesive layer contains an antistatic agent and a mixture of monomer components constituting the acrylic polymer (A) or a partial polymer of a mixture of monomer components constituting the acrylic polymer (A). formed by
The optical pressure-sensitive adhesive sheet, wherein the antistatic agent is an ionic compound having a functional group capable of forming a covalent bond with the acrylic polymer (A) in its molecule.
[Appendix 2] An optical pressure-sensitive adhesive sheet having a laminated structure in which a substrate having a first surface and a second surface and a pressure-sensitive adhesive layer is laminated on the first surface of the substrate,
The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing an antistatic agent and an acrylic polymer (A),
The optical pressure-sensitive adhesive sheet, wherein the antistatic agent is an ionic compound having a functional group capable of forming a covalent bond with the acrylic polymer (A) in its molecule.
[Appendix 3] The functional group is at least selected from the group consisting of a (meth)acryloyloxy group, a (meth)acryloylamino group, a vinyl group, an allyl group, a styryl group, a hydroxyl group, an amino group, a mercapto group, and an epoxy group. The optical pressure-sensitive adhesive sheet according to

Appendix

1 or 2, which is one type.
[Appendix 4] The optical adhesive sheet according to any one of Appendices 1 to 3, wherein the acrylic polymer (A) does not contain or substantially does not contain a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A).
[Appendix 5] The optical pressure-sensitive adhesive sheet according to any one of Appendices 1 to 4, wherein the pressure-sensitive adhesive composition contains no or substantially no organic solvent.
[Appendix 6] The optical pressure-sensitive adhesive sheet according to any one of Appendices 1 to 5, wherein the pressure-sensitive adhesive layer has a haze (according to JIS K7136) of 1.0% or less.
[Appendix 7] The optical pressure-sensitive adhesive sheet according to any one of Appendices 1 to 6, wherein the pressure-sensitive adhesive layer has a total light transmittance (according to JIS K7361-1) of 90% or more.
[Appendix 8] The optical pressure-sensitive adhesive sheet according to any one of Appendices 1 to 7, which has a 180° peeling adhesive force to a glass plate at 23° C. of 4 N/20 mm or more.
[Appendix 9] The optical pressure-sensitive adhesive sheet according to any one of Appendices 1 to 8, which has a thickness of 12 to 350 μm.
[Appendix 10] The optical pressure-sensitive adhesive sheet according to any one of Appendices 1 to 9, wherein the second surface of the substrate is subjected to antireflection treatment, antiglare treatment, hard coat treatment and/or antistatic treatment.
[Appendix 11] An optical laminate obtained by laminating the optical pressure-sensitive adhesive sheet according to any one of Appendices 1 to 10 and an optical member.
[Appendix 12] An image display device in which the optical pressure-sensitive adhesive sheet according to any one of Appendices 1 to 10 and an image display panel are laminated.

The optical pressure-sensitive adhesive sheet of the present invention is less likely to cause defects in transparency, appearance, and durability, exhibits a low surface resistivity, and has excellent antistatic performance, so it is suitable for manufacturing image display devices.

REFERENCE SIGNS LIST 10 optical pressure-sensitive adhesive sheet 1 substrate 2 pressure-sensitive adhesive layer 3 antireflection treatment, anti-glare treatment, and/or antistatic treatment 4 separator 20 optical laminate 5 optical member 30 image display device 6 image display panel

Claims

An optical pressure-sensitive adhesive sheet having a laminated structure in which a substrate having a first surface and a second surface and a pressure-sensitive adhesive layer is laminated on the first surface of the substrate,
A pressure-sensitive adhesive composition in which the pressure-sensitive adhesive layer contains an antistatic agent and a mixture of monomer components constituting the acrylic polymer (A) or a partial polymer of a mixture of monomer components constituting the acrylic polymer (A). formed by
The optical pressure-sensitive adhesive sheet, wherein the antistatic agent is an ionic compound having in its molecule a functional group capable of forming a covalent bond with the acrylic polymer (A).
An optical pressure-sensitive adhesive sheet having a laminated structure in which a substrate having a first surface and a second surface and a pressure-sensitive adhesive layer is laminated on the first surface of the substrate,
The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing an antistatic agent and an acrylic polymer (A),
The optical pressure-sensitive adhesive sheet, wherein the antistatic agent is an ionic compound having in its molecule a functional group capable of forming a covalent bond with the acrylic polymer (A).
The functional group is at least one selected from the group consisting of a (meth)acryloyloxy group, a (meth)acryloylamino group, a vinyl group, an allyl group, a styryl group, a hydroxyl group, an amino group, a mercapto group, and an epoxy group. The optical pressure-sensitive adhesive sheet according to claim 1 or 2.
The optical pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein the acrylic polymer (A) does not contain or substantially does not contain a carboxyl group-containing monomer as a monomer component constituting the acrylic polymer (A).
The optical pressure-sensitive adhesive sheet according to any one of claims 1 to 4, wherein the pressure-sensitive adhesive composition contains no or substantially no organic solvent.
The optical pressure-sensitive adhesive sheet according to any one of claims 1 to 5, wherein the pressure-sensitive adhesive layer has a haze (according to JIS K7136) of 1.0% or less.
The optical pressure-sensitive adhesive sheet according to any one of claims 1 to 6, wherein the pressure-sensitive adhesive layer has a total light transmittance (according to JIS K7361-1) of 90% or more.
The optical pressure-sensitive adhesive sheet according to any one of claims 1 to 7, which has a 180° peeling adhesive force to a glass plate at 23°C of 4 N/20 mm or more.
The optical pressure-sensitive adhesive sheet according to any one of claims 1 to 8, which has a thickness of 12 to 350 µm.
The optical pressure-sensitive adhesive sheet according to any one of claims 1 to 9, wherein the second surface of the base material is subjected to antireflection treatment, antiglare treatment, hard coat treatment and/or antistatic treatment.
An optical laminate in which the optical pressure-sensitive adhesive sheet according to any one of claims 1 to 10 and an optical member are laminated.
An image display device in which the optical pressure-sensitive adhesive sheet according to any one of claims 1 to 10 and an image display panel are laminated.