JP7440993B2 - Optical film with adhesive layer, image display panel and image display device - Google Patents

Description

The present invention relates to an optical film with an adhesive layer. The optical film with an adhesive layer of the present invention can be applied to an image display panel, and the image display panel can form an image display device such as a liquid crystal display (LCD) or an organic EL display device. Moreover, the image display panel can be used as an image display panel with a bezel, which includes a bezel as an outer frame on the outside of the image display panel.

2. Description of the Related Art Image display panels such as liquid crystal display panels have a polarizing film disposed in an image display section such as a liquid crystal cell due to its image forming method. Generally, in an image display panel, at least a polarizing film is bonded to an image display portion via an adhesive layer.

A pressure-sensitive adhesive containing a base polymer and a crosslinking agent is usually used to form the pressure-sensitive adhesive layer. As the base polymer, an acrylic pressure-sensitive adhesive using an acrylic polymer is used. Such adhesives have removability that allows them to be easily peeled off even if the polarizing film is pasted to the image display area in the wrong position or if foreign matter gets caught in the pasted surface. (reworkability) is required. In addition to reworkability, the adhesive layer is required to improve white spots (unevenness around the periphery) and improve durability, and acrylic polymers are being used as adhesive compositions that can improve the above properties. , it has been proposed to blend a polyether compound having a reactive silyl group (Patent Document 1).

Further, a bezel (outer frame) is usually provided on the outside of the image display panel from the viewpoint of ease of handling. In recent years, emphasis has been placed on design, and there is a tendency for bezels to have narrower frames (Patent Documents 2 and 3).

JP2010-275522A Japanese Patent Application Publication No. 2012-014000 Japanese Patent Application Publication No. 2016-004214

When applying the above image display panel with a narrow bezel to an image display device such as a mobile phone, a cover glass or the like is placed on the surface of the image display panel. When applied to an image display device, since a cover glass or the like is usually not placed on the surface of the image display panel, the strength of the viewing side surface of the image display panel cannot be said to be sufficient. As a countermeasure, when using a notebook computer, etc., an elastic body is provided at the top of the bezel, for example, to prevent the image display panel from coming into direct contact with the main body of the image display device when it is closed. There is. However, when the bezel has a narrow frame, it may be difficult to provide the elastic body above the bezel. Therefore, when using a bezel with a narrow frame, a mode is also being considered in which an elastic intermediate layer is provided between the end surface of the image display panel and the bezel, protruding from the outermost surface of the image display panel on the viewing side. .

Generally, when opening and closing an image display panel of a notebook computer or the like, the outer edge of the image display panel is often touched with bare hands. Bare hands contain oil components (oleic acid, etc.) based on sebum, and even after using moisturizing creams, sunscreen creams, etc., the components of these creams may remain on bare hands. In such a case, when a notebook computer or the like using a bezel-equipped image display panel provided with the elastic intermediate layer is opened and closed with bare hands, the oil or cream component may be directly or indirectly transmitted through the elastic intermediate layer. It has been found that there is a possibility that the adhesive layer that adheres the polarizing film or the like to the image display area may reach the adhesive layer, and that the adhesive layer absorbs the component and expands. In particular, in a humid environment, the adhesive layer that has absorbed the above-mentioned components is likely to expand, and peeling of the adhesive layer from the image display area has become a problem. However, the adhesive layer formed from the adhesive composition described in Patent Document 1 cannot solve the problem of peeling.

In addition, the adhesive layer swells due to the oil and cream components that reach the adhesive layer, and furthermore, the transparent protective film of the polarizing film bonding the adhesive layer absorbs the oil and cream components. It was also found that swelling causes whitening (occurrence of cracks) due to cracking of the transparent protective film. Due to these defects, oil and cream components tend to intervene at the interface between the adhesive layer and the transparent protective film, and furthermore, the surface of the transparent protective film may be deformed. As a result, it was also found that there is a possibility that peeling between the adhesive layer and the transparent protective film may be induced.

The present invention is an optical film with an adhesive layer that can be applied to image display panels, etc., and when oil or cream components reach the adhesive layer of the optical film with an adhesive layer in a humidified environment. Also, an optical film with an adhesive layer can suppress peeling of the adhesive layer and suppress cracks that occur in the transparent protective film of the polarizing film included in the optical film (has crack resistance). The purpose is to provide.

Another object of the present invention is to provide an image display panel using the adhesive layer-attached optical film, and further to provide an image display device using the image display panel.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using the following adhesive layer-attached optical film, etc., and have completed the present invention.

That is, the present invention is an optical film with an adhesive layer having an optical film and an adhesive layer,
The thickness of the optical film is 75 μm or more,
The optical film includes a single-protection polarizing film having a transparent protective film (but not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less, and the adhesive layer includes a single-protection polarizing film having a transparent protective film (not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less. It is provided on the side that does not have a protective film,
The adhesive layer is
At least one monomer (a) selected from alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms, alkoxyalkyl (meth)acrylates, fluorine-containing monomers, and acrylonitrile as a monofunctional monomer unit 80 Based on a (meth)acrylic polymer (A) containing 20% by mass or more of n-butyl acrylate as a monofunctional monomer unit, or 70% by mass or more of alkoxyalkyl (meth)acrylate. Contains as a polymer,
and contains a silane coupling agent (B),
An image display panel with a bezel, characterized in that it is formed from an adhesive composition that has a polyether skeleton and does not contain a polyether compound that has a reactive silyl group at at least one end. .

In the optical film with an adhesive layer, the adhesive layer may be provided on a single-protection polarizing film via a retardation film.

In the optical film with an adhesive layer, the adhesive layer may be provided directly on the polarizer of the single-protection polarizing film.

In the optical film with an adhesive layer, it is preferable that the optical film has a surface treatment layer on the outermost surface on the viewing side.

In the optical film with an adhesive layer, the thickness of the optical film is preferably 300 μm or less.

In the optical film with an adhesive layer, the thickness of the adhesive layer is preferably 10 to 30 μm.

In the optical film with an adhesive layer, it is also suitable that the adhesive layer has an oleic acid swelling degree of more than 130% and 190% or less.

In the optical film with an adhesive layer, all of the monomers (a) are alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms, and 30% by mass of n-butyl acrylate is used as the monomer unit. Those containing the above can be used (aspect (1)).

In the above aspect (1), the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms is all n-butyl acrylate, and contains 70% by mass or more of n-butyl acrylate as the monomer unit. (Aspect (10)).

Further, in the above aspect (10), the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms is an alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms (provided that n-butyl acrylate is ) and n-butyl acrylate can be used (aspect (11)).

Furthermore, in the above aspect (11), 4 to 60% by mass of an alkyl (meth)acrylate (excluding n-butyl acrylate) having an alkyl group having 1 to 4 carbon atoms as the monomer unit, n- A material containing 30% by mass or more of butyl acrylate can be used.

Furthermore, in the above aspect (11), as the monomer unit, 15 to 60% by mass of alkyl acrylate having an alkyl group having 1 to 4 carbon atoms (excluding n-butyl acrylate), and n-butyl acrylate A material containing 30% by mass or more can be used (aspect (11A)).

Furthermore, in the above aspect (11), the monomer unit contains 5 to 15% by mass of alkyl methacrylate having an alkyl group having 1 to 4 carbon atoms and 70% by mass or more of n-butyl acrylate. (Aspect (11B)).

Further, in the optical film with an adhesive layer, the monomer (a) contains the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms and the fluorine-containing monomer, and the monomer unit includes the carbon A material containing 30% by mass or more of an alkyl (meth)acrylate having a number of 1 to 4 alkyl groups, 25% by mass or more of a fluorine-containing monomer, and 30% by mass or more of n-butyl acrylate can be used. (Aspect (21)).

Further, in the optical film with an adhesive layer, the monomer (a) contains the alkyl (meth)acrylate and acrylonitrile having the alkyl group having 1 to 4 carbon atoms, and the monomer unit includes the alkyl group having 1 to 4 carbon atoms. A material containing 70% by mass or more of alkyl (meth)acrylate having an alkyl group of No. 4, 5% by mass or more of acrylonitrile, and 70% by mass or more of n-butyl acrylate can be used (Aspect (22) ).

Further, in the bezel-equipped image display panel, the monomer (a) may contain 70% by mass or more of the alkoxyalkyl (meth)acrylate (aspect (23)).

In the optical film with an adhesive layer, the silane coupling agent (B) may be at least one selected from an epoxy group-containing silane coupling agent (b1) and a mercapto group-containing silane coupling agent (b2). preferable. The epoxy group-containing silane coupling agent (b1) is preferably a low molecular weight epoxy group-containing silane coupling agent (b1). Further, the mercapto group-containing silane coupling agent (b2) is preferably an oligomer-type mercapto group-containing silane coupling agent (b2).

In the optical film with an adhesive layer, the adhesive composition may contain a crosslinking agent.

The present invention also relates to an image display panel comprising an image display section and the adhesive layer-attached optical film. The image display panel can be used in such a manner that the optical film with an adhesive layer is disposed on the viewing side of the image display section via the adhesive layer of the optical film with an adhesive layer.

The present invention also relates to a liquid crystal display device having the image display panel.

Since the optical film with a pressure-sensitive adhesive layer of the present invention has an optical film having a thickness exceeding a predetermined range, it is possible to prevent or to some extent prevent oil and cream components from reaching or coming into contact with the pressure-sensitive adhesive layer. Further, the optical film with an adhesive layer of the present invention is formed of an adhesive layer containing an acrylic polymer containing a predetermined monomer in a predetermined proportion or more as a base polymer, and containing a silane coupling agent. Therefore, even if oil or cream components reach the adhesive layer in a humidified environment, peeling from the adherend due to swelling of the adhesive layer can be suppressed.

Further, the optical film with an adhesive layer of the present invention uses a single-protection polarizing film having a transparent protective film (but not including a retardation film) on one side of a polarizer as the polarizing film, and the adhesive layer is provided on the side of the single-protection polarizing film that does not have the transparent protective film, so even if the adhesive layer absorbs oil or cream components in a humidified environment and swells, the Since there is no transparent protective film on the side to which the adhesive layer is bonded, it is possible to effectively suppress the occurrence of cracks in the transparent protective film. Further, since the polarizer is a thin polarizer with a thickness of 10 μm or less, shrinkage of the polarizer in a humid environment can be suppressed to a small extent, and peeling between the polarizer and the adhesive layer is less likely to occur.

1 is a part of a cross-sectional view showing an example of a bezel-equipped image display panel to which the adhesive layer-equipped optical film of the present invention can be applied. 1A is a top view showing an example of the bezel-equipped image display panel according to FIG. 1A. FIG. 1 is a part of a cross-sectional view showing an example of a bezel-equipped image display panel to which the adhesive layer-equipped optical film of the present invention can be applied. 2A is a top view showing an example of the bezel-equipped image display panel according to FIG. 2A. FIG. 1 is a part of a cross-sectional view showing an example of a bezel-equipped image display panel to which the adhesive layer-equipped optical film of the present invention can be applied. 3A is a top view showing an example of the bezel-equipped image display panel according to FIG. 3A. FIG. FIG. 3 is a top view showing an example of a frame-shaped elastic intermediate layer. It is a part of sectional drawing which shows an example of the image display panel with a bezel based on a comparative example.

An image display panel to which the optical film with an adhesive layer of the present invention can be applied will be described below with reference to the drawings. In the following, a case will be described in which an optical film with an adhesive layer is applied to an image display panel with a bezel.
For example, an image display panel with a bezel to which the optical film with an adhesive layer of the present invention is applied has an image display section 1 and an adhesive layer 3 on the viewing side of the image display section 1, as shown in the cross-sectional view of FIG. 1A. An image display panel A having an optical film 2 is disposed therebetween, and an external bezel 5 is provided on the outside of the end surface of the image display panel A. FIG. 1A is a part of a cross-sectional view showing an example of an image display panel with a bezel, and one edge portion is shown. FIG. 1B is a top view of a bezel-equipped image display panel to which the adhesive layer-equipped optical film of the present invention is applied. The outer bezel 5 is provided via the elastic intermediate layer 4. The elastic intermediate layer 4 is provided so as to protrude from the outermost surface a on the viewing side of the image display panel A (optical film 2), and the external bezel 5 is provided without covering the elastic intermediate layer 4. It is being The end surface of the image display panel A and the elastic intermediate layer 4 are designed to reduce the thickness of the entire image display device, from the viewpoint of narrowing the frame and expanding the display area, and from the viewpoint of preventing moisture, oil, and cream components from entering. From the viewpoint of preventing cracks from entering from the edges of the image display panel when the thickness is reduced, it is preferable to use a mode in which they are in contact with each other. The outer bezel 5 can be fixed to the elastic intermediate layer 4 by adhesive.

On the other hand, a gap S may be provided between the end surface of the image display panel A and the elastic intermediate layer 4, as shown in FIG. 2A, from the viewpoint of simplifying the manufacturing process of fitting and installing the panel in the housing. can. FIG. 2B is a top view of a bezel-equipped image display panel to which the adhesive layer-equipped optical film of the present invention is applied. It is preferable that the gap S is provided in a range of 2000 μm or less. When the gap S is provided, moisture, oil, and cream components easily enter the gap S, but according to the bezel-equipped image display panel of the present invention, even when placed in a humidified environment, Peeling of the adhesive layer can be suppressed. Regardless of the presence or absence of the gap S, the end surface of the optical film 2 can be coated with an acrylic resin, a urethane resin, a silicone resin, a fluorine resin, or the like.

Further, as shown in the cross-sectional view of FIG. 3A, the bezel-equipped image display panel to which the adhesive layer-equipped optical film of the present invention is applied has the embodiment shown in FIG. 1A or FIG. An internal bezel 6 can be provided on the outermost surface a inside the elastic intermediate layer 4 in the end face portion. FIG. 3B is a top view of a bezel-equipped image display panel to which the adhesive layer-equipped optical film of the present invention is applied. Also in this embodiment, the elastic intermediate layer 4 is used in such a manner that it protrudes beyond the inner bezel 6. In the embodiment shown in FIG. 3A, a case is illustrated in which a cavity 7 is provided between the end surface of the image display panel A and the elastic intermediate layer 4, but the embodiment shown in FIG. The end surface of the display panel A and the elastic intermediate layer 4 can be used in a state where they are in contact with each other. In the case of providing a vacant room 7 in the embodiment shown in FIG. 6. The inner bezel 6 can be fixed to the outermost surface a of the image display panel A and the elastic intermediate layer 4 with an adhesive.

Further, an image display panel with a bezel to which the optical film with an adhesive layer of the present invention is applied has a distance t between the outermost surface a on the viewing side of the image display panel A (optical film 2) and the adhesive layer 3 2) is set to 75 μm or more. If the distance t is less than 75 μm, it is difficult to prevent the adhesive layer 3 from peeling off even in a humid environment where oil or cream components may come into contact with the elastic intermediate layer. The distance t is preferably 100 μm or more, more preferably 120 μm or more in order to suppress peeling of the adhesive layer 3. On the other hand, as the distance t becomes longer (that is, as the thickness of the optical film becomes thicker), the optical film tends to shrink more in size in a humidified environment and warp more easily. Therefore, the distance t is 300 μm or less. The thickness is preferably 250 μm or less, and more preferably 250 μm or less. The distance t corresponds to the thickness of the optical film, and in the optical film with an adhesive layer of the present invention, the thickness of the optical film is 75 μm or more, while it is preferably 300 μm or less.

Further, from the viewpoint of narrowing the frame of the bezel-equipped image display panel, it is preferable that the widths of the external bezel 5 and the elastic intermediate layer 4 are both small. The widths of the external bezel 5 and the elastic intermediate layer 4 are set appropriately depending on the size of the image display panel A, but usually the width of the external bezel 5 is 5 mm or less, and is preferably 0.5 to 5 mm. is preferable, and more preferably 0.5 to 3 mm. Further, the width of the elastic intermediate layer 4 is 5 mm or less, preferably 0.5 to 5 mm, and more preferably 0.5 to 3 mm. Further, the internal bezel 6 is also preferably small from the viewpoint of narrowing the frame. Usually, the width of the internal bezel 6 is preferably 1 to 20 mm, more preferably 1 to 15 mm. Furthermore, when the empty chamber 7 is provided, its width is preferably 1 to 20 mm, more preferably 1 to 15 mm. When the internal bezel 6 is provided, even if oil or cream components come into contact with the elastic intermediate layer 4, the possibility of the components reaching and coming into contact with the adhesive layer 3 is reduced, so that the empty space 7 is The width is preferably 1 mm or more.

Further, in the embodiment shown in FIG. 1A, the elastic intermediate layer 4 protrudes beyond the outermost surface a on the viewing side of the image display panel A (optical film 2), and in the embodiment shown in FIG. 3A, the inner bezel 6 It is used in a manner that is more prominent than the This protrusion prevents the image display panel from coming into direct contact with the main body of the image display device. The height of the protrusion is generally preferably 0.5 to 5 mm, more preferably 0.5 to 3 mm. Further, in the top view shown in FIG. 1B and FIG. 3B, the elastic intermediate layer 4 is provided on the entire outer side of the end surface of the image display panel A, but the elastic intermediate layer 4 is The present invention is also effective when used at least in part.

Further, as shown in FIGS. 1A, 2A, and 3A, a holding portion 41 for holding the image display panel A can be provided below the elastic intermediate layer 4. The elastic intermediate layer 4 and the holding portion 41 may be integrally molded. The width of the holding portion 41 at a portion not in contact with the bottom of the elastic intermediate layer 4 is preferably 5 mm or less, and preferably 3 mm or less, from the viewpoint of narrowing the frame and reducing weight. On the other hand, from the viewpoint of holding the image display panel A, the width of the holding portion 41 (the width of the portion not in contact with the bottom of the elastic intermediate layer 4) is preferably 0.1 mm or more, and more preferably 0.1 mm or more. It is preferable that it is .3 mm or more. In FIG. 2, in the holding part 41 of the elastic intermediate layer 4, a gap S is provided between the end surface of the image display panel A and the elastic intermediate layer 4, so that the edge of the image display panel A is However, when a gap S is provided, the width of the portion of the holding portion 41 that is not in contact with the bottom of the elastic intermediate layer 4 is longer than the width of the gap S. It is preferable to design

As shown in FIGS. 1B, 2B, and 3B, the elastic intermediate layer 4, the outer bezel 5, and the inner bezel 6 can be provided in a frame shape. In addition, when the elastic intermediate layer 4 is used in a frame shape as shown in FIG. , some sides can be omitted from the viewpoint of ease of handling. Furthermore, the inner side of the elastic intermediate layer 4 can have a convex portion 42 that is fitted into the elastic intermediate layer 4 to fix it to the housing. For example, in FIG. 4, two protrusions 42 are provided on each of three sides inside the frame. The number of the protrusions 42 can be set arbitrarily.

<External bezel, internal bezel>
The external bezel forms an outer frame on the outside of the end surface of the image display panel to protect it, and can be used without any particular restriction as is normally applied to the image display panel. Further, the internal bezel protects the outermost surface of the end face portion of the image display panel, and can be used without any particular restriction as is normally applied to the image display panel.

<Elastic intermediate layer>
As mentioned above, the elastic intermediate layer is used to avoid direct contact between the image display panel and the main body of the image display device, and is made of a material that can reduce the impact caused by such contact when a laptop computer or the like is closed. There are no particular restrictions. Examples of materials forming the elastic intermediate layer include nitrile rubber, fluororubber, urethane rubber, silicone rubber, ethylene propylene rubber, hydrogenated nitrile rubber, chloroprene rubber, acrylic rubber, butyl rubber, which are used in rubber packing, etc. Rubber materials such as chlorosulfonated polyethylene, epichlorohydrin rubber, and natural rubber can be used. Other materials for the elastic intermediate layer include, for example, elastic plastics such as vinyl chloride resin and urethane resin, and cushion foam foams.

<Optical film>
The optical film of the present invention will be explained below. As mentioned above, the optical film of the present invention contains a polarizing film. The optical film of the present invention can be formed of a polarizing film alone, or can be formed as a laminated optical film that is a combination of a polarizing film and another film. The thickness of the optical film (also in the case of a laminated optical film) is designed to be 75 μm or more. On the other hand, it is preferable to design the thickness to be 300 μm or less.

≪Polarizing film≫
As the polarizing film contained in the optical film, a single-protection polarizing film having a transparent protective film (but not including a retardation film) on only one side of the polarizer is used. In the single-side protection polarizing film, the adhesive layer is provided on the side of the single-side protection polarizing film that does not have the transparent protective film.

When the adhesive layer is provided directly on the polarizer of the single-side protection polarizing film, the layer structure (1) of the single-side protection polarizing film and the adhesive layer is shown below.
Layer configuration (1): transparent protective film/polarizer/adhesive layer In addition, when the adhesive layer is provided on the single-protection polarizing film via a retardation film, the single-protection polarizing film and the adhesive The layer structure (2) of the layers is shown below.
Layer structure (2): Transparent protective film/polarizer/retardation film/adhesive layer

The polarizer is not particularly limited, and various types can be used. As a polarizer, for example, a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film, a partially saponified ethylene/vinyl acetate copolymer film, or a dichroic film such as iodine or a dichroic dye is used. Examples include polyene-based oriented films such as those obtained by adsorbing a substance and uniaxially stretched, dehydrated polyvinyl alcohol, and dehydrochloric acid treated polyvinyl chloride. Among these, a polarizer made of a polyvinyl alcohol film and a dichroic substance such as iodine is suitable.

Further, as the polarizer, it is preferable to use a thin polarizer with a thickness of 10 μm or less. In particular, it is preferable to use a thin polarizer in the single-protection polarizing film. It is preferable that the thickness of the polarizer is 3 μm or more in order to suppress peeling of the adhesive layer due to oil or cream components. Further, from the viewpoint of suppressing dimensional shrinkage in a humid environment, the thickness of the polarizer is preferably 10 μm or less. A thin polarizer with a thickness of 3 to 10 μm is preferable because it has less unevenness in thickness, has excellent visibility, and has excellent durability because of little dimensional change, and can also be made thinner as a polarizing film.

As a material constituting the transparent protective film, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetylcellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, and cyclic resins. Examples include polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. A transparent protective film is bonded to one side of the polarizer using an adhesive layer, while a transparent protective film made of (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone is attached to the other side of the polarizer. A thermosetting resin such as a thermosetting resin or an ultraviolet curable resin can be used.

As the material for the transparent protective film, cellulose resin and (meth)acrylic resin are preferable. As the (meth)acrylic resin, it is preferable to use a (meth)acrylic resin having a lactone ring structure. Examples of (meth)acrylic resins having a lactone ring structure include JP-A Nos. 2000-230016, 2001-151814, 2002-120326, 2002-254544, and 2005- Examples include (meth)acrylic resins having a lactone ring structure, such as those described in Japanese Patent No. 146084. In particular, cellulose resin is preferable to (meth)acrylic resin in that it is more effective in suppressing polarizer cracking, which is a problem in single-protection polarizing films that have a transparent protective film on only one side of the polarizer. The thickness of the transparent protective film is generally preferably 10 to 100 μm, more preferably 20 to 50 μm, and even more preferably 30 to 50 μm. In particular, when cellulose resin is used as the material for the transparent protective film, it is preferable to control the thickness to 100 μm or less in order to suppress dimensional shrinkage in a humid environment.

The transparent protective film does not include a retardation film. A transparent protective film that is not included in the retardation film indicates that it is "optically isotropic", and has an in-plane retardation Re (550) of 0 nm to 10 nm, and a retardation Rth (550) in the thickness direction. is -10 nm to +10 nm.

(Definition of terms and symbols)
Definitions of terms and symbols used herein are as follows.
(1) Refractive index (nx, ny, nz)
"nx" is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., slow axis direction), and "ny" is the direction perpendicular to the slow axis in the plane (i.e., fast axis direction) "nz" is the refractive index in the thickness direction.
(2) In-plane phase difference (Re)
"Re(λ)" is the in-plane retardation of the film measured with light having a wavelength of λ nm at 23°C. For example, "Re(450)" is the in-plane retardation of the film measured with light having a wavelength of 450 nm at 23°C. Re(λ) is determined by the formula: Re=(nx−ny)×d, where d (nm) is the thickness of the film.
(3) Phase difference in thickness direction (Rth)
"Rth (λ)" is the retardation in the thickness direction of the film measured with light having a wavelength of 550 nm at 23°C. For example, "Rth (450)" is the retardation in the thickness direction of the film measured using light with a wavelength of 450 nm at 23°C. Rth (λ) is determined by the formula: Rth=(nx-nz)×d, where d (nm) is the thickness of the film.

The adhesive used for bonding the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and various types of adhesives such as water-based, solvent-based, hot-melt, radical curing, and cationic curing types can be used. However, water-based adhesives or radical curing adhesives are preferred.

≪Surface treatment layer≫
A surface treatment layer can be provided on the outermost surface of the optical film. Examples of the surface treatment layer include functional layers such as a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer, and an antiglare layer. The surface treatment layer can be provided on the transparent protective film used for the polarizing film, and can also be provided on a separate base material from the transparent protective film. As the separate base material, the same material as the transparent protective film can be used. When the surface treatment layer is provided separately, it can be bonded to the polarizing film using a conventionally known adhesive layer or the like. The surface treatment layer is provided on the opposite side of the polarizing film of the optical film to the side on which the adhesive layer is provided.

As the material for forming the hard coat layer provided as the surface treatment layer, for example, a thermoplastic resin or a material that is cured by heat or radiation can be used. Examples of the material include radiation curable resins such as thermosetting resins, ultraviolet curable resins, and electron beam curable resins. Among these, ultraviolet curable resins are preferred because they can efficiently form a cured resin layer through simple processing operations through curing treatment using ultraviolet irradiation. These curable resins include various types such as polyester, acrylic, urethane, amide, silicone, epoxy, and melamine resins, and include monomers, oligomers, and polymers of these resins. Radiation-curable resins, especially ultraviolet-curable resins, are particularly preferred because of their high processing speed and low heat damage to the base material. Preferably used UV-curable resins include, for example, those having UV-polymerizable functional groups, especially those containing acrylic monomers or oligomer components having two or more, particularly 3 to 6, functional groups. Moreover, a photopolymerization initiator is blended into the ultraviolet curable resin.

Further, as the surface treatment layer, an antiglare treatment layer or an antireflection layer for the purpose of improving visibility can be provided. Moreover, an anti-glare treatment layer or an anti-reflection layer can be provided on the hard coat layer. The constituent material of the anti-glare treatment layer is not particularly limited, and for example, radiation-curable resins, thermosetting resins, thermoplastic resins, etc. can be used. As the antireflection layer, titanium oxide, zirconium oxide, silicon oxide, magnesium fluoride, etc. are used. A plurality of antireflection layers can be provided. Other examples of the surface treatment layer include an anti-sticking layer.

≪Other layers≫
In addition to the above-mentioned layers, the optical film (laminated optical film) may include a retardation film (including a 1/2 or 1/4 wavelength plate), a visual compensation film, and the like. Further, the polarizing film and other optical layers may be provided with an anchor layer or an easily bonding layer, or may be subjected to various adhesion-facilitating treatments such as corona treatment or plasma treatment.

As shown in the layer structure (2), the adhesive layer can be provided on the single-protection polarizing film via a retardation film. Examples of the retardation film include a birefringent film formed by uniaxially or biaxially stretching a polymer material, an oriented film of a liquid crystal polymer, and a film in which an oriented layer of a liquid crystal polymer is supported by a film. These retardation films can be used singly or in combination of two or more layers.

When applying an optical film with an adhesive layer to an image display panel for a PC, the retardation film is preferably provided between the polarizer and the image display section from the viewpoint of viewing angle compensation, low reflectance, etc. This differentiates it from the above-mentioned transparent protective film. In addition, retardation films can generally be used with a thickness of 4 to 150 μm, but the thinner the thickness is within an appropriate range, the better to suppress peeling of the adhesive layer in a humid environment and to prevent the retardation film from peeling off in a humid environment. This is advantageous in suppressing cracks in the film, and for example, the thickness (total) of the retardation film is preferably 2 to 25 μm, more preferably 4 to 24 μm.

<Adhesive layer>
The adhesive layer in the adhesive layer-attached optical film will be described below. The adhesive layer contains, as a base polymer, at least one monomer selected from alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms, alkoxyalkyl (meth)acrylates, fluorine-containing monomers, and acrylonitrile ( (meth)acrylic containing 80% by mass or more of a) as a monofunctional monomer unit, and 20% by mass or more of n-butyl acrylate as a monomer unit, or 70% by mass or more of alkoxyalkyl (meth)acrylate It is formed from an adhesive composition containing a polymer (A). The monofunctional monomer unit is a unit of a compound having one unsaturated double bond such as a (meth)acryloyl group or a vinyl group, which constitutes the (meth)acrylic polymer (A). The (meth)acrylic polymer (A) includes a partial polymer of a monomer component containing the alkyl (meth)acrylate (a) and/or a (meth)acrylic polymer obtained from the monomer component. Note that (meth)acrylate refers to acrylate and/or methacrylate, and (meth) in the present invention has the same meaning.

The main skeleton of the (meth)acrylic polymer (A) is one selected from the alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms, alkoxyalkyl (meth)acrylates, fluorine-containing monomers, and acrylonitrile. Formed from at least one monomer (a). The mass ratio of the monomer (a) is 80% by mass as the monomer unit based on the mass ratio of all constituent monomers (monofunctional monomer 100% by mass, the same shall apply hereinafter) constituting the (meth)acrylic polymer (A). By using the (meth)acrylic polymer (A) in such a proportion, peeling of the adhesive layer due to oil or cream components can be suppressed.

Examples of the alkyl group in the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms include linear or branched alkyl groups, such as methyl group, ethyl group, propyl group, isopropyl group, Examples include n-butyl group, isobutyl group, t-butyl group, and the like.

The alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms is preferably an alkyl (meth)acrylate having an alkyl group having 4 carbon atoms, and n-butyl acrylate is particularly preferable. N-butyl acrylate is an essential monomer unit constituting the (meth)acrylic polymer (A), and the monomer (a) can be composed only of n-butyl acrylate. The mass ratio of n-butyl acrylate, as a monomer unit, is 20% by mass or more in the mass ratio of all constituent monomers (monofunctional monomer 100% by mass) constituting the (meth)acrylic polymer (A), By using the (meth)acrylic polymer (A) in such a proportion, peeling of the adhesive layer due to oil or cream components can be suppressed. The mass ratio of n-butyl acrylate can be 30% by mass or more, 40% by mass or more, 50% by mass or more, furthermore 60% by mass or more, and can be used in an amount of 70% by mass or more, further can be used in an amount of 80% by mass or more, and further can be used in an amount of 90% by mass or more.

The alkoxyalkyl (meth)acrylate is not particularly limited, but the alkoxyalkyl group is preferably an alkoxyalkyl group having a total of 3 to 25 carbon atoms. For example, the alkoxyalkyl (meth)acrylates include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4- Examples include methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, and other alkoxypolyalkylene glycols such as methoxytriethylene glycol (meth)acrylate. Examples include acrylate (Bismer MPE400A manufactured by Osaka Organic Chemical Industry Co., Ltd.).

The fluorine-containing monomer is not particularly limited, but has a radically polymerizable carbon-carbon double bond such as a (meth)acryloyl group or a vinyl group, and has 3 to 10 carbon atoms substituted with at least one fluorine atom. Examples include those having an alkyl group. For example, examples of the fluorine-containing monomer include 2,2,2-trifluoroethyl acrylate, 2-(perfluorohexyl)ethyl acrylate, 2,2,3,3,3-pentafluoropropyl acrylate, 2-( Perfluorobutyl)ethyl acrylate, 3-perfluorobutyl-2-hydroxypropyl acrylate, 3-perfluorohexyl-2-hydroxypropyl acrylate, 3-(perfluoro-3-methylbutyl)-2-hydroxypropyl acrylate, 1H, 1H,3H-tetrafluoropropyl acrylate, 1H,1H,5H-octafluoropentyl acrylate, 1H,1H,7H-dodecafluoroheptyl acrylate, 1H-1-(trifluoromethyl)trifluoroethyl acrylate, 1H,1H,3H -hexafluorobutyl acrylate, 1,2,2,2-tetrafluoro-1-(trifluoromethyl)ethyl acrylate, and the like. Note that among the above-mentioned fluorine-containing monomers, those having a hydroxy group are not included in the hydroxyl group-containing monomers described below.

Further, as the monomer (a), at least one selected from alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms, alkoxyalkyl (meth)acrylates, fluorine-containing monomers, and acrylonitrile is used. , the monomer (a) may be entirely composed of the alkyl (meth)acrylate having the alkyl group having 1 to 4 carbon atoms (aspect (1)). In the case of this embodiment (1), it is preferable that the monomer unit contains 30% by mass or more of n-butyl acrylate. This aspect (1) is preferable from the viewpoint of ensuring durability against heating and moist heat.

In the embodiment (1) in which all of the monomers (a) are alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms, for example, all of the monomers (a) are n-butyl acrylate. Embodiment (10) formed by the above method can be adopted. In the case of this aspect (10), it is preferable that the monomer unit contains 70% by mass or more of n-butyl acrylate. In this case, the monomer unit of n-butyl acrylate may be used in an amount of 80% by mass or more, 90% by mass or more, and even 95% by mass or more, depending on the type of copolymer monomer, crosslinking agent, etc. be able to. This aspect (10) is preferable from the viewpoint of securing heating and moist heat durability.

Further, as the embodiment (1) in which all of the above-mentioned monomers (a) are alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms, for example, in addition to n-butyl acrylate, n-butyl acrylate Embodiment (11) in which the above-mentioned alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms is used in combination can be adopted. As the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms other than n-butyl acrylate, alkyl (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and t-butyl acrylate are preferable. The alkyl (meth)acrylate having an alkyl group having 1 to 3 carbon atoms is preferably an alkyl (meth)acrylate having an alkyl group having 1 to 2 carbon atoms, such as methyl acrylate, methyl methacrylate, or ethyl acrylate. That is, in the embodiment (11) in which n-butyl acrylate is used in combination with the monomer (a) other than n-butyl acrylate, the monomer (a) is an alkyl (meth) having an alkyl group having 1 to 3 carbon atoms. ) acrylate or t-butyl acrylate, and n-butyl acrylate are preferably used. This aspect (11) is preferable from the viewpoint of oil resistance, processability, handling, and crack resistance.

In the case of the embodiment (11) of the combination system, the mass ratio of the alkyl (meth)acrylate having an alkyl group having 1 to 3 carbon atoms is preferably 4 to 60% by mass, more preferably 4 to 50% by mass. , more preferably 10 to 40% by mass, while the mass ratio of n-butyl acrylate is preferably 30% by mass or more, more preferably 30 to 96% by mass, even more preferably 40 to 90% by mass, It is preferable to adjust the total amount to 80% by mass or more.

Furthermore, in the embodiment (11) of the combination system, an embodiment (11A) in which an alkyl acrylate is used as the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms (excluding n-butyl acrylate). In some cases, the mass proportion of the alkyl acrylate is preferably 15 to 60% by mass, more preferably 15 to 45% by mass, even more preferably 20 to 40% by mass, while the mass proportion of n-butyl acrylate is preferably is preferably adjusted to 30% by mass or more, more preferably 40 to 85% by mass, even more preferably 40 to 75% by mass, so that the total amount is 80% by mass or more. This embodiment (11A) is preferable from the viewpoint of oil resistance, processability, handling, and crack resistance.

Furthermore, in the embodiment (11) of the combination system, an embodiment (11B) in which an alkyl methacrylate is used as the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms (excluding n-butyl acrylate). In this case, the mass ratio of the alkyl methacrylate is preferably 5 to 15% by mass, more preferably 5 to 10% by mass, while the mass ratio of n-butyl acrylate is 70% by mass or more, more preferably 70 to 10% by mass. Assuming 90% by mass, it is preferable to adjust the total to 80% by mass or more. This embodiment (11B) is preferable from the viewpoint of workability, handling, and crack resistance.

Further, as the monomer (a), for example, embodiment (21) can be adopted in which the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms and the fluorine-containing monomer are used in combination. In the case of embodiment (21) of the combination system, the mass ratio of the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms is preferably 30% by mass or more, more preferably 30 to 55% by mass, The fluorine-containing monomer is preferably 25% by mass or more, more preferably 25 to 50% by mass, and the total is adjusted to 80% by mass or more, and the n-butyl acrylate is preferably 30% by mass or more, more preferably 30 to 50% by mass. It is preferable to adjust the content to 55% by mass. This aspect (21) is preferable from the viewpoint of oil resistance.

Further, as the monomer (a), for example, embodiment (22) can be adopted in which the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms and acrylonitrile are used in combination. In the case of embodiment (22) of the combination system, the mass ratio of the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms is preferably 70% by mass or more, more preferably 70 to 85% by mass, Acrylonitrile is preferably 5% by mass or more, more preferably 10 to 20% by mass, and adjusted to a total of 80% by mass or more, and n-butyl acrylate is preferably 70% by mass or more, more preferably 70 to 85% by mass. %. This aspect (22) is preferable from the viewpoint of heating durability.

Further, as the monomer (a), for example, embodiment (23) in which 70% by mass or more of the alkoxyalkyl (meth)acrylate is used can be adopted. In the case of the above embodiment (23), the alkoxyalkyl (meth)acrylate can be used in an amount of 80% by mass or more, further 90% by mass or more, and even 100% by mass. Furthermore, in embodiment (23), the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms can be used in combination. The mass ratio of the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms is preferably 20% by mass or more, and the alkoxyalkyl (meth)acrylate is preferably 70% by mass or more, more preferably 70 to 99% by mass. %, and the total amount is adjusted to 80% by mass or more, and n-butyl acrylate is preferably adjusted to 20% by mass or more. This embodiment (23) is preferable from the viewpoint of high adhesive strength and oil resistance.

In addition, in embodiments (21) to (23) of the above combination system, n-butyl acrylate or the alkoxyalkyl (meth)acrylate having the alkyl group having 1 to 4 carbon atoms within the range that satisfies the mass ratio. The alkyl (meth)acrylate can be used in combination with monomers other than n-butyl acrylate. In particular, in the above aspect (21), as the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms, the alkyl acrylate having an alkyl group having 1 to 3 carbon atoms is used in addition to n-butyl acrylate. The embodiment can be preferably adopted.

In addition to the monomer units of the monomer (a), the (meth)acrylic polymer (A) also contains unsaturated dihydrogens such as a (meth)acryloyl group or a vinyl group for the purpose of improving adhesiveness and heat resistance. One or more types of copolymerizable monomers having a polymerizable functional group having a double bond can be introduced by copolymerization. The copolymerization monomer mass ratio is 20% by mass or less.

However, if the polymerization ratio of alkyl (meth)acrylate having an alkyl group having 5 or more carbon atoms increases, this is not preferable from the viewpoint of suppressing the peeling of the adhesive described above. ) Acrylate has a polymerization ratio of 20% by mass or less, more preferably 15% by mass or less, further preferably 10% by mass or less, further preferably 5% by mass or less, further preferably 3% by mass or less, and is preferably 1% by mass or less, and most preferably not used.

As the copolymerizable monomer, for example, an aromatic ring-containing (meth)acrylate can be used. An aromatic ring-containing (meth)acrylate is a compound that contains an aromatic ring structure in its structure and also contains a (meth)acryloyl group. Examples of the aromatic ring include a benzene ring, a naphthalene ring, and a biphenyl ring.

Specific examples of aromatic ring-containing (meth)acrylates include benzyl (meth)acrylate, phenyl (meth)acrylate, o-phenylphenol (meth)acrylate phenoxy (meth)acrylate, phenoxyethyl (meth)acrylate, and phenoxypropyl. (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide modified nonylphenol (meth)acrylate, ethylene oxide modified cresol (meth)acrylate, phenol ethylene oxide modified (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate Acrylate, methoxybenzyl (meth)acrylate, chlorobenzyl (meth)acrylate, cresyl (meth)acrylate, polystyryl (meth)acrylate, etc. that have a benzene ring; hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth)acrylate , 2-naphthoxyethyl acrylate, 2-(4-methoxy-1-naphthoxy)ethyl (meth)acrylate, etc. having a naphthalene ring; and biphenyl (meth)acrylate, etc. having a biphenyl ring.

As the aromatic ring-containing (meth)acrylate, benzyl (meth)acrylate and phenoxyethyl (meth)acrylate are preferable from the viewpoint of adhesive properties and durability, and phenoxyethyl (meth)acrylate is particularly preferable.

The mass ratio of the aromatic ring-containing (meth)acrylate is 20% by mass or less, preferably 3 to 18% by mass, more preferably 5 to 16% by mass, and even more preferably 10 to 14% by mass. When the mass ratio of the aromatic ring-containing (meth)acrylate is 3% by mass or more, it is preferable for suppressing display unevenness.

Examples of the copolymerizable monomer include functional group-containing monomers such as hydroxyl group-containing monomers, carboxyl group-containing monomers, and amide group-containing monomers.

The hydroxyl group-containing monomer is a compound that contains a hydroxyl group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Specific examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxypropyl (meth)acrylate. Examples include hydroxyalkyl (meth)acrylates and (4-hydroxymethylcyclohexyl)-methyl acrylate, such as hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate. Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred from the viewpoint of durability, with 4-hydroxybutyl (meth)acrylate being particularly preferred.

A carboxyl group-containing monomer is a compound that contains a carboxyl group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Specific examples of carboxyl group-containing monomers include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and the like. Among the carboxyl group-containing monomers, acrylic acid is preferred from the viewpoints of copolymerizability, price, and adhesive properties.

The hydroxyl group-containing monomer and the carboxyl group-containing monomer become reaction points with the crosslinking agent when the adhesive composition contains the crosslinking agent. Hydroxyl group-containing monomers and carboxyl group-containing monomers have high reactivity with intermolecular crosslinking agents, and are therefore preferably used to improve the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer.

The mass ratio of the hydroxyl group-containing monomer is preferably 3% by mass or less, more preferably 0.01 to 3% by mass, further preferably 0.1 to 2% by mass, and even more preferably 0.2 to 2% by mass. 2% by mass is preferred. It is preferable that the mass ratio of the hydroxyl group-containing monomer is 0.01% by mass or more from the viewpoint of crosslinking the adhesive layer, durability, and adhesive properties. On the other hand, if it exceeds 3% by mass, it is not preferred from the viewpoint of durability.

The mass ratio of the carboxyl group-containing monomer is preferably 10% by mass or less, more preferably 0.01 to 8% by mass, further preferably 0.05 to 6% by mass, and even more preferably 0.1 to 6% by mass. 5% by mass is preferred. From the viewpoint of durability, it is preferable that the mass ratio of the carboxyl group-containing monomer is 0.01% by mass or more.

The amide group-containing monomer is a compound that contains an amide group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Specific examples of amide group-containing monomers include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N- Butyl (meth)acrylamide, N-hexyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methylol-N-propane (meth)acrylamide, aminomethyl (meth)acrylamide, aminoethyl (meth)acrylamide, mercaptomethyl Acrylamide monomers such as (meth)acrylamide and mercaptoethyl (meth)acrylamide; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and N-(meth)acryloylpyrrolidine; N -Vinyl pyrrolidone, N-vinyl group-containing lactam monomers such as N-vinyl-ε-caprolactam, and the like. An amide group-containing monomer is preferable in terms of suppressing an increase in surface resistance over time (particularly in a humid environment) and satisfying durability. Among the amide group-containing monomers, N-vinyl group-containing lactam monomers are particularly preferred.

If the mass ratio of the amide group-containing monomer increases, the anchoring property to the optical film tends to decrease, so the mass ratio is preferably 10% by mass or less, and more preferably 5% by mass or less. Particularly preferred. From the viewpoint of suppressing an increase in surface resistance value over time (especially under a humid environment), the content is preferably 0.1% by mass or more. The mass ratio is preferably 0.3% by mass or more, and more preferably 0.5% by mass or more.

Specific examples of copolymerizable monomers other than those mentioned above include; monomers containing acid anhydride groups such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; allylsulfonic acid, 2-(meth)acrylamide-2 - Sulfonic acid group-containing monomers such as methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, and sulfopropyl (meth)acrylate; and phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

In addition, alkylaminoalkyl (meth)acrylates such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; methoxyethyl (meth)acrylate, ethoxyethyl ( Alkoxyalkyl (meth)acrylates such as meth)acrylate; N-(meth)acryloyloxymethylene succinimide, N-(meth)acryloyl-6-oxyhexamethylene succinimide, N-(meth)acryloyl-8-oxyoctamethylene succinimide, etc. Succinimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide; N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N- Itaconimide monomers such as octyl itaconimide, N-2-ethylhexyl itaconimide, N-cyclohexy itaconimide, and N-lauryl itaconimide are also mentioned as examples of monomers for modification purposes.

Furthermore, as modifying monomers, vinyl monomers such as vinyl acetate and vinyl propionate; epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate; glycols such as polyethylene glycol (meth)acrylate and polypropylene glycol (meth)acrylate; (meth)acrylate monomers such as tetrahydrofurfuryl (meth)acrylate and silicone (meth)acrylate can also be used. Further examples include isoprene, butadiene, isobutylene, vinyl ether, and the like.

Furthermore, examples of copolymerizable monomers other than those mentioned above include silane monomers containing silicon atoms. Examples of the silane monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. , 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

The proportion of the other copolymerizable monomer in the (meth)acrylic polymer (A) is 0 to 0 in the mass proportion of all the constituent monomers (monofunctional monomer 100% by mass) of the (meth)acrylic polymer (A). It is preferably about 10% by mass, more preferably about 0 to 7% by mass, and even more preferably about 0 to 5% by mass.

In addition, the copolymerization monomers include tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol A diglycidyl ether di(meth)acrylate, neo Pentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate , (meth)acryloyl groups such as esters of (meth)acrylic acid and polyhydric alcohol such as caprolactone-modified dipentaerythritol hexa(meth)acrylate, and polyfunctional compounds having two or more unsaturated double bonds such as vinyl groups. polyester (meth)acrylate, epoxy (meth)acrylate, epoxy ( It is also possible to use meth)acrylate, urethane(meth)acrylate, and the like.

When the above-mentioned polyfunctional monomer or the like is used as the copolymerizable monomer, the polyfunctional monomer functions as a crosslinking component. The amount of the polyfunctional monomer used varies depending on its molecular weight, number of functional groups, etc., but it is preferably used in an amount of 1 part by mass or less, and 0.5 part by mass or less, based on a total of 100 parts by mass of monofunctional monomers. More preferred. Further, the lower limit is not particularly limited, but it is preferably 0 parts by mass or more, and more preferably 0.01 parts by mass or more. When the amount of the polyfunctional monomer used is within the above range, adhesive strength can be improved.

The (meth)acrylic polymer (A) of the present invention usually preferably has a weight average molecular weight of 1,000,000 to 2,500,000. Considering durability, especially heat resistance, the weight average molecular weight is preferably 1.2 million to 2 million. It is preferable that the weight average molecular weight is 1 million or more from the viewpoint of heat resistance. Furthermore, when the weight average molecular weight is greater than 2.5 million, the adhesive tends to become hard and peeling tends to occur. Further, the weight average molecular weight (Mw)/number average molecular weight (Mn), which indicates molecular weight distribution, is preferably 1.8 or more and 10 or less, more preferably 1.8 to 7, and even more preferably 1.8 to 10. Preferably, it is 5. When the molecular weight distribution (Mw/Mn) exceeds 10, it is unfavorable from the viewpoint of durability. Note that the weight average molecular weight and molecular weight distribution (Mw/Mn) are measured by GPC (gel permeation chromatography) and determined from values calculated by polystyrene conversion.

For the production of such (meth)acrylic polymer (A), known production methods such as various radical polymerizations such as solution polymerization, bulk polymerization, emulsion polymerization, and radiation (UV) polymerization can be appropriately selected. Moreover, the obtained (meth)acrylic polymer (A) may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

In addition, in solution polymerization, ethyl acetate, toluene, etc. are used as a polymerization solvent, for example. As a specific example of solution polymerization, the reaction is carried out under a flow of an inert gas such as nitrogen, a polymerization initiator is added, and the reaction condition is usually about 50 to 70° C. for about 5 to 30 hours.

The polymerization initiator, chain transfer agent, emulsifier, etc. used in radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight of the (meth)acrylic polymer (A) can be controlled by the amount of polymerization initiator and chain transfer agent used and reaction conditions, and the amount used can be adjusted as appropriate depending on the type of these. Ru.

Moreover, the adhesive composition forming the adhesive layer of the present invention contains a silane coupling agent (B) as an additive. A (meth)acrylic polymer (A) containing the silane coupling agent (B) in an amount of 80% by mass or more based on the monomer unit of the alkyl (meth)acrylate (a) having an alkyl group having 1 to 4 carbon atoms. By using it in combination, it is possible to suppress the peeling of the adhesive layer due to oil and cream components.

As the silane coupling agent (B), it is preferable to use at least one selected from epoxy group-containing silane coupling agents (b1) and mercapto group-containing silane coupling agents (b2).

Examples of the epoxy group-containing silane coupling agent (b1) include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-( Low molecular type (non-oligomer type) epoxy group-containing silane coupling agents such as 3,4-epoxycyclohexyl)ethyltrimethoxysilane, X-41-1053, X-41-1056, and X manufactured by Shin-Etsu Chemical Co., Ltd. Examples include oligomer-type epoxy group-containing silane coupling agents such as -41-1059A, X-24-9590, and KR-516. The epoxy group-containing silane coupling agent (b1) is preferably a low molecular type (non-oligomer type) epoxy group-containing silane coupling agent because it has a large effect of suppressing peeling of the adhesive layer due to oil or cream components.

Further, as the mercapto group-containing silane coupling agent (b2), 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldiethoxysilane, β - Low molecular type (non-oligomer type) mercapto group-containing silane coupling agents such as mercaptomethylphenylethyltrimethoxysilane, mercaptomethyltrimethoxysilane, 6-mercaptohexyltrimethoxysilane, and 10-mercaptodecyltrimethoxysilane, Examples include X-41-1805, X-41-1810, and X-41-1818 manufactured by Shin-Etsu Chemical. The mercapto group-containing silane coupling agent (b2) is preferably an oligomer-type mercapto group-containing silane coupling agent because it has a great effect of suppressing peeling of the adhesive layer due to oil or cream components.

In addition, examples of low-molecular-weight silane coupling agents (B) other than those mentioned above include acetoacetyl group-containing silane coupling agents such as A100 manufactured by Soken Chemical Co., Ltd.; 3-aminopropyltrimethoxysilane, N-2- Silanes containing amino groups such as (aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, and N-phenyl-γ-aminopropyltrimethoxysilane. Coupling agent; (meth)acrylic group-containing silane coupling agent such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane; Isocyanate group-containing silane coupling agent such as 3-isocyanatepropyltriethoxysilane etc. Examples of oligomer-type silane coupling agents other than those mentioned above include, for example, KR-213 manufactured by Shin-Etsu Chemical Co., Ltd.

These silane coupling agents having a plurality of alkoxysilyl groups in their molecules are preferred because they are difficult to volatilize and are effective in improving durability because they have a plurality of alkoxysilyl groups. In particular, durability is also suitable when the adherend of the adhesive-attached optical film is a transparent conductive layer (for example, ITO, etc.) in which alkoxysilyl groups are less likely to react than glass. Note that the oligomer type refers to a polymer of about 2 or more monomers and less than 100 monomers, and the weight average molecular weight of the oligomer type silane coupling agent is preferably about 300 to 30,000.

The silane coupling agent (B) may be used alone or in combination of two or more, but the total content is lower than that of the (meth)acrylic polymer (A). It is preferably 0.01 to 5 parts by weight, more preferably 0.02 to 3 parts by weight, even more preferably 0.05 to 1 part by weight, and even more preferably 0.1 to 0.8 parts by weight per 100 parts by weight. Parts by mass are preferred. In addition, as mentioned above, it is preferable to use at least one kind selected from the epoxy group-containing silane coupling agent (b1) and the mercapto group-containing silane coupling agent (b2) as the silane coupling agent (B), When these silane coupling agents (b1) and (b2) are used together with another silane coupling agent, the other silane coupling agent is based on 100 parts by mass of the (meth)acrylic polymer (A). , 3 parts by mass or less, and the same amount or less as the silane coupling agent (B).

The adhesive composition of the present invention can contain a crosslinking agent (C). As the crosslinking agent (C), an organic crosslinking agent or a polyfunctional metal chelate can be used. Examples of the organic crosslinking agent include isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, imine crosslinking agents, and the like. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, etc. Can be mentioned. Examples of atoms in the organic compound that form a covalent bond or coordinate bond include oxygen atoms, and examples of the organic compound include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, ketone compounds, and the like.

As the crosslinking agent (C), an isocyanate-based crosslinking agent is preferable. As the isocyanate crosslinking agent, a compound having at least two isocyanate groups can be used. For example, known aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, etc., which are generally used in urethanization reactions, are used.

The amount of the crosslinking agent (C) used is preferably 3 parts by mass or less, more preferably 0.01 to 3 parts by mass, and more preferably 0.01 to 3 parts by mass, based on 100 parts by mass of the (meth)acrylic polymer (A). The amount is preferably from 0.02 to 2 parts by weight, more preferably from 0.03 to 1 part by weight. In addition, if the crosslinking agent (C) is less than 0.01 parts by mass, the adhesive may be insufficiently crosslinked and the durability and adhesive properties may not be satisfied, whereas if it is more than 3 parts by mass, the adhesive may become hard. If it is too high, there is a tendency for durability to decrease.

Furthermore, the adhesive composition of the present invention may contain other known additives, such as antistatic agents, colorants, powders such as pigments, dyes, surfactants, plasticizers, adhesives, etc. properties imparting agent, surface lubricant, leveling agent, softener, antioxidant, anti-aging agent, light stabilizer, ultraviolet absorber, polymerization inhibitor, inorganic or organic filler, metal powder, particulate, foil-like material etc. can be added as appropriate depending on the purpose of use. Further, within a controllable range, a redox system may be employed in which a reducing agent is added. These additives are preferably used in an amount of 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 1 part by mass or less, based on 100 parts by mass of the (meth)acrylic polymer (A).

On the other hand, the pressure-sensitive adhesive composition of the present invention does not contain a polyether compound having a polyether skeleton and having a reactive silyl group at at least one end. Examples of the polyether compound having a reactive silyl group include those disclosed in JP-A No. 2010-275522. The polyether compound having a reactive silyl group is preferable since it can improve reworkability, but it is not preferable from the viewpoint of suppressing peeling of the adhesive layer due to oil or cream components. When the polyether compound having a reactive silyl group is used, peeling of the adhesive layer cannot be suppressed even if the silane coupling agent (B) is used.

The adhesive layer of the present invention can be used as an optical film with an adhesive layer bonded to an optical film (containing at least one polarizing film). The optical film with an adhesive layer can be obtained by forming an adhesive layer on at least one side of the optical film using the adhesive composition.

The method for forming the adhesive layer is, for example, by applying the adhesive composition to a release-treated separator, etc., drying and removing the polymerization solvent, etc. to form an adhesive layer, and then applying the adhesive composition to an optical film (polarizing film). It is produced by a method of transferring, or a method of applying the adhesive composition to an optical film (polarizing film) and drying and removing the polymerization solvent etc. to form an adhesive layer into an optical film. In addition, when applying the adhesive, one or more solvents other than the polymerization solvent may be newly added as appropriate.

The thickness of the adhesive layer is not particularly limited, but as it becomes thinner, the adhesion with the image display area decreases, and it tends to be less likely to peel off during heat shrinkage.On the other hand, as it becomes thicker, oil and cream components For example, the thickness is preferably about 10 to 30 μm, and more preferably 15 to 20 μm, since it is easily absorbed by the adhesive layer and peeling occurs easily.

The pressure-sensitive adhesive layer usually has an oleic acid swelling degree of 100% by mass or more, and the smaller the oleic acid swelling degree, the smaller the influence exerted by oleic acid. According to the optical film with an adhesive layer of the present invention, when the oleic acid swelling degree of the adhesive layer exceeds 130%, furthermore, when it is 140% or more, and even when it is 150% or more, the adhesive layer It is possible to minimize the effects of oil and cream components. Further, when the oleic acid swelling degree of the adhesive layer exceeds 130%, the adhesive layer absorbs oil and cream components, thereby reducing the influence on other optical members. On the other hand, as the oleic acid swelling degree of the adhesive layer increases, the influence of oil and cream components on the adhesive layer also increases, so the oleic acid swelling degree is preferably 190% or less, and preferably 180% or less. is preferred.

<Image display section>
The image display section forms a part of an image display device together with the optical film (containing at least one polarizing film) in the optical film with an adhesive layer, and the image display device includes a liquid crystal display device, Examples include organic EL (electroluminescence) display devices, PDP (plasma display panels), and electronic paper.

As the image display section, a liquid crystal cell used in a liquid crystal display device can be exemplified. The liquid crystal cell may be of any type, such as a TN type, STN type, π type, VA type, or IPS type.

<Image display panel>
In addition to the optical films described above, other optical films can be laminated and used to form an image display panel, depending on the suitability of each location. For example, in a liquid crystal display panel, at least a polarizing film is disposed on the opposite side to the viewing side of the liquid crystal cell, but the polarizing film is not particularly limited. Examples of the other optical films include reflective plates, anti-transmissive plates, retardation films (including 1/2 and 1/4 wavelength plates), visual compensation films, brightness enhancement films, and other liquid crystal display devices. Examples include those that serve as optical layers that are sometimes used in the formation of. These can be used in one layer or two or more layers.

<Image display device>
Various image display devices such as the liquid crystal display device of the present invention can be formed according to conventional methods. It is formed by appropriately assembling component parts such as a lighting system as necessary and incorporating a drive circuit. Generally, a liquid crystal display device incorporates a drive circuit by appropriately assembling components such as a liquid crystal cell (a structure of glass substrate/liquid crystal layer/glass substrate), polarizing films placed on both sides of the cell, and a lighting system as needed. It is formed by such things as The optical film is placed on the viewing side, and another polarizing film is placed on the other side. Furthermore, an appropriate liquid crystal display device may be formed using a backlight or a reflector in the illumination system. Furthermore, when forming a liquid crystal display device, appropriate parts such as a diffusion plate, an anti-glare layer, an antireflection film, a protection plate, a prism array, a lens array sheet, a light diffusion plate, and a backlight are placed in one layer or at appropriate positions. Two or more layers can be arranged.

The present invention will be specifically explained below with reference to production examples and examples, but the present invention is not limited to these examples. Note that all parts and percentages in each example are based on weight. All room temperature storage conditions below, unless otherwise specified, are 23° C. and 65% RH.

<Measurement of weight average molecular weight of (meth)acrylic polymer (A)>
The weight average molecular weight (Mw) of the (meth)acrylic polymer was measured by GPC (gel permeation chromatography). Mw/Mn was also measured in the same manner.
・Analyzer: Tosoh Corporation, HLC-8120GPC
・Column: Manufactured by Tosoh Corporation, G7000H _XL +GMH _XL +GMH _XL
・Column size: 7.8mmφ each x 30cm total 90cm
・Column temperature: 40℃
・Flow rate: 0.8mL/min
・Injection volume: 100μL
・Eluent: Tetrahydrofuran ・Detector: Differential refractometer (RI)
・Standard sample: polystyrene

<Preparation of optical film>
Optical films A to D used in Examples, Comparative Examples, and Reference Examples were prepared as follows.

(Preparation of thin polarizer)
Corona treatment is applied to one side of the base material of an amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100 μm) with a water absorption rate of 0.75% and a Tg of 75°C. Alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (degree of polymerization 1200, degree of acetoacetyl modification 4.6%, degree of saponification 99.0 mol% or more, manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd.) , trade name "Gosefaimer Z200") in a ratio of 9:1 was applied and dried at 25° C. to form a PVA-based resin layer with a thickness of 11 μm, thereby producing a laminate.
The obtained laminate was uniaxially stretched free end to 2.0 times in the longitudinal direction (longitudinal direction) between rolls having different circumferential speeds in an oven at 120° C. (in-air auxiliary stretching treatment).
Next, the laminate was immersed for 30 seconds in an insolubilization bath (boric acid aqueous solution obtained by blending 4 parts of boric acid with 100 parts of water) at a liquid temperature of 30° C. (insolubilization treatment).
Next, the polarizing plate was immersed in a dyeing bath at a liquid temperature of 30° C. while adjusting the iodine concentration and immersion time so that the polarizing plate had a predetermined transmittance. In this example, the material was immersed for 60 seconds in an iodine aqueous solution obtained by blending 0.2 parts of iodine and 1.0 parts of potassium iodide with respect to 100 parts of water (staining treatment).
Next, it was immersed for 30 seconds in a crosslinking bath (boric acid aqueous solution obtained by blending 3 parts of potassium iodide and 3 parts of boric acid with 100 parts of water) at a liquid temperature of 30°C (crosslinking treatment). ).
Thereafter, the laminate was immersed in a boric acid aqueous solution (an aqueous solution obtained by blending 4 parts of boric acid and 5 parts of potassium iodide with 100 parts of water) at a liquid temperature of 70°C. Uniaxial stretching was performed between rolls having different speeds in the longitudinal direction (longitudinal direction) so that the total stretching ratio was 5.5 times (underwater stretching treatment).
Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by blending 4 parts of potassium iodide with 100 parts of water) at a liquid temperature of 30° C. (cleaning treatment).
As a result of the above, an optical film laminate containing a polarizer having a thickness of 5 μm was obtained.

(Transparent protective film)
Acrylic film 1: A (meth)acrylic resin film having a thickness of 40 μm and having a lactone ring structure was used, and the adhesion-promoting surface thereof was subjected to corona treatment.
TAC film: A triacetyl cellulose film with a thickness of 40 μm was saponified and used.
COP film 1: A cycloolefin resin film (trade name: ZF14-013, manufactured by Nippon Zeon Co., Ltd.) with a thickness of 13 μm was used.
COP film 2: A cycloolefin resin film (trade name: ZF14-013, manufactured by Nippon Zeon Co., Ltd.) with a thickness of 25 μm was used.
All of the above transparent protective films are "optically isotropic", with an in-plane retardation Re (550) of 0 nm to 10 nm, and a thickness direction retardation Rth (550) of -10 nm. It was ~+10 nm.

(Preparation of adhesive applied to transparent protective film)
10 parts of N-hydroxyethyl acrylamide, 30 parts of acryloylmorpholine, 45 parts of 1,9-nonanediol diacrylate, 10 parts of an acrylic oligomer obtained by polymerizing (meth)acrylic monomer (ARUFONUP1190, manufactured by Toagosei Co., Ltd.), photopolymerization Three parts of an initiator (IRGACURE 907, manufactured by BASF) and two parts of a polymerization initiator (KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.) were mixed to prepare an ultraviolet curable adhesive.

(Retardation film)
First retardation film: A cyclic olefin film with a thickness of 18 μm (refractive index characteristics: nx>ny>nz, in-plane retardation: 116 nm) was used.

Second retardation film: A modified polyethylene film with a thickness of 6 μm (refractive index characteristics: nz>nx>ny, in-plane retardation: 35 nm) was used.

<Single protection polarizing film>
While applying the ultraviolet curable adhesive a to the surface of the polarizer of the optical film laminate so that the thickness of the adhesive layer after curing is 1 μm, apply the transparent protective film (thickness: 40 μm: acrylic film 1 or After laminating the adhesive (TAC film), ultraviolet rays were irradiated as active energy rays to cure the adhesive. Ultraviolet irradiation was performed using a gallium-filled metal halide lamp, irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak illuminance: 1600 mW/cm ² , cumulative irradiation amount 1000/mJ/cm ² (wavelength 380 to 440 nm) ), and the illuminance of ultraviolet light was measured using the Sola-Check system manufactured by Solatell. Next, the amorphous PET base material was peeled off, and a single protective polarizing film with a thickness of 46 μm using a thin polarizer was produced.
The single-protection polarizing film 1 using the acrylic film 1 was used to prepare the following single-protection polarizing film with a retardation film.
When the TAC film was used, it was used as it was as the single protection polarizing film 2.

<Single protection polarizing film with retardation film>
A first retardation film and a second retardation film were sequentially attached to the thin polarizer side of the single-piece protection polarizing film 1 to obtain a single-piece protection polarizing film with a retardation film having a thickness of 72 μm. For bonding, the same ultraviolet curing adhesive a as above was used to form an adhesive layer with a thickness of 1 μm. Note that the slow axis of the first retardation film forms an angle of 0° with respect to the absorption axis of the polarizer, and the slow axis of the second retardation film forms an angle of 90° with respect to the absorption axis of the polarizer. Pasted together.

<Preparation of both protective polarizing films>
The COP film 1 (thickness: 25 μm) was laminated onto the surface of the polarizer of the optical film laminate while applying the UV curable adhesive a so that the thickness of the adhesive layer after curing was 1 μm. Afterwards, the adhesive was cured by irradiation with ultraviolet rays as active energy rays. Ultraviolet irradiation was performed using a gallium-filled metal halide lamp, irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak illuminance: 1600 mW/cm ² , cumulative irradiation amount 1000/mJ/cm ² (wavelength 380 to 440 nm) ), and the illuminance of ultraviolet light was measured using the Sola-Check system manufactured by Solatell. Next, the amorphous PET base material was peeled off, and the COP film 2 (thickness: 13 μm) was laminated to the peeled surface using the adhesive described above, and then cured in the same manner to form a film with a thickness of 45 μm using a thin polarizer. Both protective polarizing films were produced.

<Preparation of film with surface treatment layer: ARTAC: thickness 44 μm)>
An antireflection layer with a thickness of 4 μm was formed on a triacetyl cellulose film with a thickness of 40 μm by sputtering.

<Preparation of film with surface treatment layer: ARTAC: thickness 84 μm>
An antireflection layer with a thickness of 4 μm was formed on a triacetyl cellulose film with a thickness of 80 μm by sputtering.

<Preparation of film with surface treatment layer: LCTAC (thickness 42 μm)>
A liquid crystal retardation layer with a thickness of 2 μm was formed on a triacetyl cellulose film with a thickness of 40 μm by coating.

<Preparation of adhesive layer A>
(Preparation of acrylic polymer)
A monomer mixture containing 100 parts of n-butyl acrylate and 5 parts of acrylic acid was charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. Furthermore, to 100 parts of the monomer mixture (solid content), 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was charged together with 100 parts of ethyl acetate, and nitrogen gas was added while stirring gently. After introducing the flask and purging it with nitrogen, a polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55° C. to prepare a solution of an acrylic polymer having a weight average molecular weight (Mw) of 1.6 million.

(Preparation of adhesive composition)
To 100 parts of the solid content of the acrylic polymer solution obtained above, 0.45 parts of an isocyanate crosslinking agent (Coronate L manufactured by Tosoh Corporation, trimethylolpropane tolylene diisocyanate) was blended to create an acrylic adhesive. A solution of the drug composition was prepared.

(Formation of adhesive layer)
Next, the solution of the acrylic adhesive composition was applied to one side of a polyethylene terephthalate film (separator film: manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., MRF38) treated with a silicone release agent, so that the dried adhesive layer It was coated to a thickness of 23 μm or 12 μm, and dried at 155° C. for 1 minute to form an adhesive layer A on the surface of the separator film.

Optical films A to F were prepared by laminating the polarizing film and the film with a surface treatment layer in the following configuration. The lamination was carried out by bonding the surface treatment layer-equipped film to the triacetyl cellulose film side via the adhesive layer A. In the lamination of the single-protection polarizing film with the retardation film, the adhesive layer A was bonded to the acrylic film 1 side. The single-protection polarizing film 2 was laminated by laminating the adhesive layer A on the TAC film side. In the lamination of both protective polarizing films, the adhesive layer A was attached to the COP film 2 side.
Optical film A (total thickness 128 μm): ARTAC (thickness 44 μm)/adhesive layer A (thickness 12 μm)/piece protection polarizing film with retardation film (thickness 72 μm).
Optical film B (total thickness 179 μm): ARTAC (thickness 84 μm)/adhesive layer A (thickness 23 μm)/piece protection polarizing film with retardation film (thickness 72 μm).
Optical film C (total thickness 244 μm): ARTAC (thickness 84 μm) / Adhesive layer A (thickness 23 μm) / LCTAC (thickness 42 μm) / Adhesive layer A (thickness 23 μm) / Single protection polarizing film with retardation film (thickness 72 μm) ).
Optical film D (total thickness: 72 μm): single-protection polarizing film with retardation film (thickness: 72 μm).
Optical film E (total thickness 217 μm): ARTAC (thickness 84 μm)/adhesive layer A (thickness 23 μm)/LCTAC (thickness 42 μm)/adhesive layer A (thickness 23 μm)/both protective polarizing films (thickness 45 μm).
Optical film F (total thickness 244 μm): ARTAC (thickness 84 μm)/adhesive layer A (thickness 23 μm)/LCTAC (thickness 42 μm)/adhesive layer A (thickness 23 μm)/piece protection polarizing film 2 (thickness 72 μm).

Example 1
(Preparation of acrylic polymer)
In a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser, 81.9 parts of n-butyl acrylate, 13.2 parts of benzyl acrylate, 0.1 part of 4-hydroxybutyl acrylate, and acrylic acid. A monomer mixture containing 4.8 parts was charged. Further, to 100 parts of the monomer mixture (solid content), 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was charged together with 100 parts of ethyl acetate, and nitrogen gas was introduced while stirring gently. After introducing the flask and purging it with nitrogen, the temperature of the liquid in the flask was maintained at around 55° C. and a polymerization reaction was carried out for 8 hours to prepare a solution of an acrylic polymer having a weight average molecular weight (Mw) of 1.6 million.

(Preparation of adhesive composition)
For 100 parts of solid content of the acrylic polymer solution obtained above,
Oligomeric mercapto group-containing silane coupling agent (X-41-1810 manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2 parts, isocyanate crosslinking agent (Coronate L manufactured by Tosoh Corporation, trimethylolpropane tolylene diisocyanate) 0.45 parts A solution of an acrylic pressure-sensitive adhesive composition was prepared.

(Formation of adhesive layer)
Next, the solution of the acrylic adhesive composition was applied to one side of a polyethylene terephthalate film (separator film: manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., MRF38) treated with a silicone release agent, so that the dried adhesive layer It was applied to a thickness of 20 μm and dried at 155° C. for 1 minute to form an adhesive layer B on the surface of the separator film.

(Preparation of optical film with adhesive layer and production of image display panel)
An image display section (liquid crystal cell including a diagonal size of 15 inches: thickness 300 μm) was prepared.
The adhesive layer B prepared above was laminated on the side of the protective polarizing film with the retardation film of the optical film A prepared above, so that the optical film with the adhesive layer (the shorter side and the longer side of the optical film from the liquid crystal cell A 4 mm short polarizing film was also prepared. After peeling off the separator film from the optical film with the adhesive layer, the optical film A (second retardation film side) is placed on the viewing side of the image display section via the adhesive layer B using a laminator. An image display panel (liquid crystal display panel) was produced by bonding the two together. Next, the optical film A was subjected to autoclave treatment at 50° C. and 0.5 MPa for 15 minutes to completely adhere the optical film A to the image display area. Next, the obtained image display panel was laser cut and molded into a size of 15 inches.

(Production of image display panel with bezel)
As the elastic intermediate layer, a rubber molded product with a width of 1 mm and a height of 5 mm was processed to fit the outer edge of the image display panel (15 inch size) (the total width of the holding part was 1.5 mm, there were 6 convex parts, as shown in Fig. 4). An elastic intermediate layer was prepared with a length of 5 cm from both sides.
In addition, as an outer bezel, a resin plate (frame) with a metal-like sputter of 1 mm in width and 3 mm in height was prepared, which was molded to match the image display panel (15 inch size). (integrated into a concave housing frame).
The elastic intermediate layer is attached to the casing in which the external bezel is integrated, and then the image display panel is incorporated (with a gap of 1 mm or less), and the elastic intermediate layer is applied to the entire outside of the end surface of the image display device. An image display panel with a bezel having the structure shown in FIG. 2 (FIGS. 2A and 2B) in which an intermediate layer and an outer bezel were sequentially attached was produced. In the obtained bezel-equipped image display panel, the elastic intermediate layer was provided so as to protrude by 1 mm from the outermost surface on the viewing side of the image display panel (optical film A). The elastic intermediate layer had a structure in which it was in contact with the end surface of the image display panel. The outer bezel was secured to the elastic intermediate layer with adhesive.

Examples 2 to 32 and Comparative Examples 1 to 8
In Example 1, the composition or ratio of the monomer mixture used to prepare the acrylic polymer, the type or amount of the silane coupling agent used to prepare the adhesive composition, the type or amount of the crosslinking agent used, or the amount of the formed Adhesive layer B was formed in the same manner as in Example 1 except that the thickness of the adhesive layer was changed as shown in Table 1. Further, using the adhesive layer B obtained above and using the optical films A to F shown in Table 1, an optical film with an adhesive layer was prepared in the same manner as in Example 1, and then an image display panel was prepared. was created. Further, in the same manner as in Example 1, an image display panel with a bezel was produced.
In addition, when optical film E is used, adhesive layer B is attached to both protective polarizing film sides, and when optical film F is used, adhesive layer B is attached to one protective polarizing film 2 side to form an optical film with an adhesive layer. Prepared.

However, in Example 30, an image display panel with a bezel having the structure shown in FIG. 3 (FIGS. 3A and 3B) was manufactured. In the image display panel with a bezel, a metal-like sputtered resin plate (frame) with a width of 20 mm and a height of 2 mm, which is molded to match the image display panel (15 inch size), is prepared as the inner bezel. I put it together. The elastic intermediate layer was provided with a gap of 15 mm from the end surface of the image display panel. The outer bezel and the elastic intermediate layer were sized to ensure the gap. The outer bezel was secured to the elastic intermediate layer with adhesive. The inner bezel was fixed to the outermost edge of the image display panel and the elastic intermediate layer using an adhesive.

Note that the adhesive composition used to form the adhesive layer of Comparative Example 3 was prepared by the following method.
A monomer mixture consisting of 67 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of 2-hydroxyethyl acrylate (HEA), and 18 parts of N-vinyl-2-pyrrolidone (NVP) was added with 1 as a photopolymerization initiator. -Hydroxycyclohexylphenylketone (trade name: Irgacure 184, manufactured by BASF) 0.050 parts, 2,2-dimethoxy-1,2-diphenylethan-1-one (trade name: Irgacure 651, manufactured by BASF) 0. After blending 050 parts, ultraviolet rays were irradiated until the viscosity (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30 ° C.) reached about 20 Pa・s, and a part of the monomer component was polymerized. A prepolymer composition (polymerization rate: 9%) was obtained. Next, 0.09 part of hexanediol diacrylate (HDDA) was added to the prepolymer composition and mixed to obtain an adhesive composition. The above-mentioned adhesive composition was applied onto the release-treated surface of a release film (trade name "MRF#38", manufactured by Mitsubishi Plastics Co., Ltd.) to a thickness of 20 μm, and the adhesive composition was layered. was formed. Next, the surface of the other pressure-sensitive adhesive composition layer and the release-treated surface of a release film ("MRN #38", manufactured by Mitsubishi Plastics Co., Ltd.) were bonded together, and the illuminance: 4 mW/cm ² and the amount of light: Ultraviolet irradiation was performed under the conditions of 1200 mJ/cm ² to form a pressure-sensitive adhesive layer by photo-curing, thereby producing a pressure-sensitive adhesive sheet.

Reference example 1 (fabrication of image display panel with cover glass and bezel)
Using an image display panel similar to the image display panel prepared in Example 1, an image display panel with a bezel having the structure shown in FIG. 5 was produced.
An outer bezel similar to that used in Example 1 was prepared.
A tempered glass having a thickness of 1500 μm and molded to fit the image display panel (15 inch size) was prepared as a cover glass.
The image display panel was assembled by attaching the outer bezel to the entire outer side of the end surface. The outer bezel was fixed to the image display panel with adhesive. The cover glass was bonded together using an adhesive layer (LUCIACS CS9864 manufactured by Nitto Denko Corporation).

The optical films with adhesive layers and the image display panels with bezels obtained in the above examples, comparative examples, and reference examples were evaluated as follows. The evaluation results are shown in Table 1.

<Chemical test during humidification>
Using a 2 mL dropper, 10 mL of the following chemical was dropped onto the inside (all) of the elastic intermediate layer (outside bezel in the reference example) of the obtained bezel-equipped image display panel.
Oleic acid: Oleic acid (primary grade, 65% content) manufactured by Wako Pure Chemical Industries.
Vaseline moisturizing cream: UJ Body Milk COAB (contains 63% water and 26% glycerin) manufactured by Unilever.
Sunscreen Cream: EDGEWELL PERSONAL CARE Banana Boat Sunscreen Lotion SPF 30.
After the chemicals were dropped, the bezel-equipped image display panel was stored at 65° C. and 90% RH for 72 hours, and then left at room temperature (23° C.). Thereafter, the optical film with the adhesive layer was taken out from the bezel-equipped image display panel, the appearance was visually observed, and peeling of the adhesive layer B was evaluated using the following criteria.
(Evaluation criteria)
◎: No peeling.
○: No peeling, but the edges are bulged due to swelling of the glue.
△: Minute peeling of 0.5 mm or less.
NG: Peeling (peeling: mm is also listed in Table 1).

<Measurement of oleic acid swelling degree>
The adhesive layer B formed on the surface of the separator film used in each example was cut into 20 mm x 40 mm to prepare a sample, and its mass (W1) was measured. Next, the sample was immersed in oleic acid at 60°C for 24 hours at a humidity of 90%, then taken out from the oleic acid, the surface of the sample was washed with ethanol, and then immersed at 110°C for 3 hours. Dry. The mass (W3) of the sample after drying was measured, and the oleic acid swelling rate of the acrylic adhesive was calculated using the following formula (2). The mass (W2) of the sample separator film was measured separately.
Swelling rate (%) = {(W3-W2)/(W1-W2)}×100

<Crack resistance>
In the same manner as in the above <Chemical test during humidification>, 10 mL of oleic acid was dropped onto the inside (all) of the elastic intermediate layer (outside bezel in the reference example) of the bezel-equipped image display panel using a 2 mL dropper. After the chemicals were dropped, the bezel-equipped image display panel was stored at 65° C. and 90% RH for 72 hours, and then left at room temperature (23° C.).
After that, take out the optical film with an adhesive layer from the image display panel with a bezel, place the adhesive layer of the optical film with an adhesive layer on the lower side, and remove cracks in the transparent protective film of the polarizing film from the upper side. The presence or absence of occurrence (whether or not it appeared cracked and white) was visually observed using a microscope (10x magnification).
In Comparative Example 8 (an example using both protective polarizing films), the side surface of the optical film with an adhesive layer taken out was visually observed. When viewed from the side, if any of the transparent protective films on both sides of the polarizer had a crack, it was determined that there was a crack.

In Table 1,
MA: methyl acrylate,
EA: ethyl acrylate,
BA: n-butyl acrylate,
MMA: methyl methacrylate,
2EHA: 2-ethylhexyl acrylate,
Viscoat 3F: 2,2,2-trifluoroethyl acrylate,
BzA: benzyl acrylate,
4HBA: 4-hydroxybutyl acrylate,
HEA: 2-hydroxyethyl acrylate,
NVP: N-vinylpyrrolidone,
AA: acrylic acid,
MEA: methoxyethyl acrylate,
SAT10: Cylyl SAT10 manufactured by Kaneka,
KBM403: KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.
KBM573: KBM-573 manufactured by Shin-Etsu Chemical Co., Ltd.
A100: A100 (acetoacetyl group-containing silane coupling agent) manufactured by Soken Chemical Co., Ltd.
X-41-1810: Oligomeric mercapto group-containing silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd.
X-41-1056: Oligomeric epoxy group-containing silane coupling agent manufactured by Shin-Etsu Chemical Co., Ltd.
C/HX: isocyanate crosslinking agent (Coronate HX manufactured by Tosoh Corporation, isocyanurate of hexamethylene diisocyanate),
Tetrad C: epoxy crosslinking agent (Tetrad C/1,3-bis(N,N-glycidylaminomethyl)cyclohexane manufactured by Mitsubishi Gas Chemical Co., Ltd.),
C/L: Isocyanate crosslinking agent (Coronate L manufactured by Tosoh Corporation, trimethylolpropane tolylene diisocyanate),
D160N: Isocyanate crosslinking agent (Takenate D160N, trimethylolpropane hexamethylene diisocyanate manufactured by Mitsui Chemicals)
HDDA: Hexanediol diacrylate.

A Image display panel 1 Image display section 2 Optical film (including polarizing film)
3 Adhesive layer (image display side)
4 Elastic intermediate layer 41 Holding section 42 Convex section 5 External bezel 6 Internal bezel 7 Vacant space 8 Adhesive layer (cover glass side)
9 Cover glass S gap

Claims (19)

An optical film with an adhesive layer, the optical film having an optical film and an adhesive layer, used for an image display panel having an elastic intermediate layer on at least a part of the outer side of the end surface of the image display panel having an image display part,
The thickness of the optical film is 120 μm or more,
The optical film includes a single-protection polarizing film having a transparent protective film (but not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less, and the adhesive layer includes a single-protection polarizing film having a transparent protective film (not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less. It is provided on the side that does not have a protective film,
The adhesive layer is
The alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms contains 80% by mass or more as a monofunctional monomer unit, and the alkyl (meth)acrylate having an alkyl group having 1 to 4 carbon atoms is Contains a (meth)acrylic polymer (A) containing 30% by mass or more of an alkyl (meth)acrylate having 1 to 4 alkyl groups (excluding n-butyl acrylate) and n-butyl acrylate as a base polymer. death,
and contains a silane coupling agent (B),
An optical film with an adhesive layer, characterized in that it is formed from an adhesive composition that has a polyether skeleton and does not contain a polyether compound having a reactive silyl group at at least one end. An optical film with an adhesive layer, the optical film having an optical film and an adhesive layer, used for an image display panel having an elastic intermediate layer on at least a part of the outer side of the end surface of the image display panel having an image display part,
The thickness of the optical film is 120 μm or more,
The optical film includes a single-protection polarizing film having a transparent protective film (but not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less, and the adhesive layer includes a single-protection polarizing film having a transparent protective film (not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less. It is provided on the side that does not have a protective film,
The adhesive layer is
Contains 80% by mass or more of an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms as a monofunctional monomer unit, and has the alkyl group having 1 to 4 carbon atoms as the monofunctional monomer unit. Contains (meth)acrylic polymer (A) containing 4 to 60% by mass of alkyl (meth)acrylate (excluding n-butyl acrylate) and 30% by mass or more of n-butyl acrylate as a base polymer,
and contains a silane coupling agent (B),
An optical film with an adhesive layer, characterized in that it is formed from an adhesive composition that has a polyether skeleton and does not contain a polyether compound having a reactive silyl group at at least one end. An optical film with an adhesive layer, the optical film having an optical film and an adhesive layer, used for an image display panel having an elastic intermediate layer on at least a part of the outer side of the end surface of the image display panel having an image display part,
The thickness of the optical film is 120 μm or more,
The optical film includes a single-protection polarizing film having a transparent protective film (but not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less, and the adhesive layer includes a single-protection polarizing film having a transparent protective film (not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less. It is provided on the side that does not have a protective film,
The adhesive layer is
Contains 80% by mass or more of an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms as a monofunctional monomer unit, and has the alkyl group having 1 to 4 carbon atoms as the monofunctional monomer unit. Contains (meth)acrylic polymer (A) containing 15 to 60% by mass of alkyl (meth)acrylate (excluding n-butyl acrylate) and 30% by mass or more of n-butyl acrylate as a base polymer,
and contains a silane coupling agent (B),
An optical film with an adhesive layer, characterized in that it is formed from an adhesive composition that has a polyether skeleton and does not contain a polyether compound having a reactive silyl group at at least one end. An optical film with an adhesive layer, the optical film having an optical film and an adhesive layer, used for an image display panel having an elastic intermediate layer on at least a part of the outer side of the end surface of the image display panel having an image display part,
The thickness of the optical film is 120 μm or more,
The optical film includes a single-protection polarizing film having a transparent protective film (but not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less, and the adhesive layer includes a single-protection polarizing film having a transparent protective film (not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less. It is provided on the side that does not have a protective film,
The adhesive layer is
An alkyl containing 80% by mass or more of an alkyl (meth) acrylate having an alkyl group having 1 to 4 carbon atoms as a monofunctional monomer unit, and having an alkyl group having 1 to 4 carbon atoms as the monofunctional monomer unit. Contains (meth)acrylic polymer (A) containing 5 to 15% by mass of methacrylate and 70% by mass or more of n-butyl acrylate as a base polymer,
and contains a silane coupling agent (B),
An optical film with an adhesive layer, characterized in that it is formed from an adhesive composition that has a polyether skeleton and does not contain a polyether compound having a reactive silyl group at at least one end. An optical film with an adhesive layer, the optical film having an optical film and an adhesive layer, used for an image display panel having an elastic intermediate layer on at least a part of the outer side of the end surface of the image display panel having an image display part,
The thickness of the optical film is 120 μm or more,
The optical film includes a single-protection polarizing film having a transparent protective film (but not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less, and the adhesive layer includes a single-protection polarizing film having a transparent protective film (not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less. It is provided on the side that does not have a protective film,
The adhesive layer is
Containing at least 80% by mass of at least one monomer selected from alkyl (meth) acrylate and acrylonitrile having an alkyl group having 1 to 4 carbon atoms as a monofunctional monomer unit, and the monofunctional monomer Contains, as a unit, 70% by mass or more of alkyl (meth)acrylate having the alkyl group having 1 to 4 carbon atoms, 5% by mass or more of acrylonitrile, and 70% by mass or more of n-butyl acrylate (meth) Contains an acrylic polymer (A) as a base polymer,
and contains a silane coupling agent (B),
An optical film with an adhesive layer, characterized in that it is formed from an adhesive composition that has a polyether skeleton and does not contain a polyether compound having a reactive silyl group at at least one end. An optical film with an adhesive layer, the optical film having an optical film and an adhesive layer, used for an image display panel having an elastic intermediate layer on at least a part of the outer side of the end surface of the image display panel having an image display part,
The thickness of the optical film is 120 μm or more,
The optical film includes a single-protection polarizing film having a transparent protective film (but not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less, and the adhesive layer includes a single-protection polarizing film having a transparent protective film (not including a retardation film) on one side of a polarizer having a thickness of 10 μm or less. It is provided on the side that does not have a protective film,
The adhesive layer is
At least one monomer (a) selected from alkyl (meth)acrylates having an alkyl group having 1 to 4 carbon atoms, alkoxyalkyl (meth)acrylates, fluorine-containing monomers, and acrylonitrile as a monofunctional monomer unit 80 A (meth)acrylic polymer (A) containing 70% by mass or more of alkoxyalkyl (meth)acrylate as the monofunctional monomer unit and containing 70% by mass or more of alkoxyalkyl (meth)acrylate as a base polymer,
and contains a silane coupling agent (B),
An optical film with an adhesive layer, characterized in that it is formed from an adhesive composition that has a polyether skeleton and does not contain a polyether compound having a reactive silyl group at at least one end. 7. The optical film with an adhesive layer according to claim 1, wherein the adhesive layer is provided on the single-protection polarizing film via a retardation film. 8. The optical film with an adhesive layer according to claim 1, wherein the adhesive layer is provided directly on the polarizer of the single-protection polarizing film. The optical film with an adhesive layer according to claim 1 , wherein the optical film has a surface treatment layer on the outermost surface on the viewing side. The optical film with an adhesive layer according to claim 1, wherein the optical film has a thickness of 300 μm or less . The optical film with an adhesive layer according to claim 1, wherein the adhesive layer has a thickness of 10 to 30 μm. The optical film with an adhesive layer according to claim 1, wherein the adhesive layer has an oleic acid swelling degree of more than 130% and less than 190 %. 13. The silane coupling agent (B) is at least one selected from an epoxy group-containing silane coupling agent (b1) and a mercapto group-containing silane coupling agent (b2). An optical film with an adhesive layer according to any one of the above. The optical film with an adhesive layer according to claim 13 , wherein the epoxy group-containing silane coupling agent (b1) is a low molecular weight epoxy group-containing silane coupling agent (b1). The optical film with an adhesive layer according to claim 13 or 14, wherein the mercapto group-containing silane coupling agent (b2) is an oligomer-type mercapto group-containing silane coupling agent (b2). The optical film with an adhesive layer according to any one of claims 1 to 15 , wherein the adhesive composition contains a crosslinking agent. An image display panel comprising an image display section and an optical film with an adhesive layer according to any one of claims 1 to 16 , comprising an elastic intermediate layer on at least a part of the outer side of an end surface of the image display panel. Features an image display panel. 18. The image display panel according to claim 17 , wherein the optical film with an adhesive layer is disposed on the viewing side of the image display section with the adhesive layer of the optical film with an adhesive layer interposed therebetween. An image display device comprising the image display panel according to claim 17 or 18 .

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