TW202033712A - Optical film with adhesive layer, image display panel and image display device - Google Patents

Abstract

An optical film with an adhesive layer according to the present invention uses a one-side protected polarizing film which has a transparent protective film (excluding a retardation film) on one surface of a thin polarizer; and the adhesive layer is formed from an adhesive composition which contains a (meth)acrylic polymer (A) and a silane coupling agent (B), but does not contain a polyether compound that has a polyether skeleton and a reactive silyl group, and which is configured such that the (meth)acrylic polymer (A) contains 80% by mass or more of a specific monomer (a) as a monofunctional monomer unit, said specific monomer (a) containing 20% by mass or more of n-butyl acrylate or 70% by mass or more of alkoxyalkyl (meth)acrylate. This optical film with an adhesive layer is suppressed in separation even if placed in a humidified environment, with the adhesive layer being in contact with a fat, an oil or a cream component; and this optical film with an adhesive layer is able to be suppressed in the occurrence of a crack in the transparent protective film of the polarizing film.

Description

Optical film with adhesive layer, image display panel and image display device

The 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 device (LCD) and an organic EL display device. Moreover, the aforementioned image display panel can be used as a frame-attached image display panel with a frame as an outer frame on the outside of the image display panel.

Background of the invention Image display panels such as liquid crystal display panels are based on their image forming methods, and the image display parts such as liquid crystal cells are equipped with polarizing films. Generally speaking, in the image display panel, at least a polarizing film is attached to the image display part through an adhesive layer.

The formation of the aforementioned adhesive layer usually uses an adhesive containing a base polymer and a crosslinking agent. The aforementioned base polymer uses an acrylic adhesive using an acrylic polymer. The adhesive is required to have re-peelability (reworkability) so that when the polarizing film is attached to the image display part, even if the attachment position is wrong or there is a foreign object biting into the attachment surface Can be easily peeled off. Moreover, in addition to heavy workability, improvement of whitening (peripheral unevenness) or improvement of durability is required for the aforementioned adhesive layer. As an adhesive composition that can improve the aforementioned properties, there have been documents that have proposed acrylic A polyether compound having a reactive silicon group is blended with the polymer (Patent Document 1).

In addition, the outer side of the image display panel is usually provided with a frame (outer frame) from the viewpoint of handling properties and the like. In recent years, design is emphasized, and there is a tendency to narrow the frame (Patent Documents 2 and 3).

Prior art literature Patent literature Patent Document 1: Japanese Patent Application Publication No. 2010-275522 Patent Document 2: JP 2012-014000 A Patent Document 3: JP 2016-004214 A

Summary of the invention Problems to be solved by the invention When the above-mentioned image display panel with a narrowed frame is applied to an image display device such as a mobile phone, the outermost surface of the image display panel is provided with a cover glass, etc., but when it is applied to an open-close image display device such as a notebook computer, The outermost surface of the image display panel is usually not equipped with a cover glass or the like, so the strength of the visible side surface of the image display panel is not sufficient. As a countermeasure, for the purpose of preventing the image display panel from directly contacting the image display device body in the closed state when using a notebook computer or the like, for example, an elastic body is provided on the upper part of the frame. However, when the frame has been narrowed, it is sometimes difficult to provide the aforementioned elastic body on the upper part of the frame. Therefore, when using a narrow-framed frame, the following aspect was also studied: an elastic intermediate layer that is more prominent than the most visible surface of the image display panel is arranged between the end surface and the frame of the aforementioned image display panel.

Generally speaking, when the image display panel of a notebook computer is turned on and off, the outer edge of the image display panel is touched with bare hands. The bare hands have oil components (oleic acid, etc.) derived from sebum, and after using moisturizers, sunscreens, etc., these cream components may remain on the bare hands. It is known that in this case, if the bare-hand switch uses a notebook computer with a framed image display panel with the aforementioned elastic intermediate layer, the aforementioned grease or cream will pass through the aforementioned elastic intermediate layer to directly or indirectly reach the polarized light. When a film or the like is attached to the adhesive layer of the image display part, the adhesive layer will absorb the aforementioned components and expand. Especially in a humidified environment, the adhesive layer absorbing the aforementioned components will be more likely to swell, and there is a problem that the aforementioned adhesive layer peels off from the image display part. However, the adhesive layer formed of the adhesive composition described in Patent Document 1 cannot solve the aforementioned peeling problem.

In addition, it is also known that the adhesive layer is swollen due to the grease or cream component reaching the adhesive layer, and the transparent protective film of the polarizing film laminated with the adhesive layer absorbs the grease or cream component and swells. Whitening (cracking) caused by cracks in the transparent protective film. Such unfavorable conditions may cause grease or emulsifiable concentrates to easily intervene in the interface between the adhesive layer and the transparent protective film, and the surface of the transparent protective film may also deform. It is also known that the results may induce peeling of the adhesive layer and the transparent protective film.

The object of the present invention is to provide an adhesive layer-attached optical film, which can be applied to image display panels, etc., and the adhesive layer-attached optical film, even in a humidified environment, has grease or emulsifiable concentrate reaching the adhesive In the case of the adhesive layer of the optical film, the adhesive layer can still be prevented from peeling off, and the transparent protective film of the polarizing film contained in the optical film can be prevented from cracking (with crack resistance).

In addition, an object of the present invention is to provide an image display panel using the aforementioned optical film with an adhesive layer, and to provide an image display device using the image display panel.

Means to solve the problem The inventors of the present invention actively studied to solve the above-mentioned problems, and found that the above-mentioned problems can be solved by the following optical film with adhesive layer, etc., and completed the present invention.

That is, the present invention relates to an image display panel with a frame, which has an optical film and an adhesive layer; the optical film with the adhesive layer is characterized by: The thickness of the aforementioned optical film is 75μm or more; The aforementioned optical film includes a single-sided protective polarizing film, the single-sided protective polarizing film has a transparent protective film on one side of a polarizer with a thickness of 10 μm or less (but does not contain a retardation film), and the adhesive layer is provided on the aforementioned single side Protect the side of the polarizing film that does not have the aforementioned transparent protective film; The aforementioned adhesive layer is formed by the following adhesive composition: The adhesive composition contains a (meth)acrylic polymer (A) as a base polymer, and the (meth)acrylic polymer (A) contains 80% by mass or more of monomer (a) as a monofunctional monomer The monomer (a) is selected from alkyl (meth)acrylates, alkoxyalkyl (meth)acrylates, fluorine-containing monomers and acrylonitrile with a carbon number of 1 to 4 alkyl groups Any at least one, and contains 20% by mass or more of n-butyl acrylate or 70% by mass or more of alkoxyalkyl (meth)acrylate as a monofunctional monomer unit, And contains silane coupling agent (B), and It does not contain polyether compounds with a polyether skeleton and reactive silicon groups at at least one end.

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

In the aforementioned adhesive layer-attached optical film, the aforementioned adhesive layer can be used directly on the polarizer of the single-sided protective polarizing film.

Among the above-mentioned optical film with adhesive layer, the above-mentioned optical film is preferably one having a surface treatment layer on the outermost surface on the visual side.

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

In the aforementioned adhesive layer-attached optical film, the thickness of the aforementioned adhesive layer is preferably 10-30 μm.

In the aforementioned adhesive layer-attached optical film, the aforementioned adhesive layer is also suitable for the case where the swelling degree of oleic acid is greater than 130% and less than 190%.

In the aforementioned adhesive layer-attached optical film, it is possible to use: the aforementioned monomer (a) is all the aforementioned alkyl (meth)acrylate having a C1-C4 alkyl group, and contains 30% by mass as the aforementioned monomer unit The above n-butyl acrylate (aspect (1)).

It can be used: In the above aspect (1), the alkyl (meth)acrylate having a C1-C4 alkyl group is all n-butyl acrylate, and the monomer unit contains more than 70% by mass of n-acrylate Those with butyl ester (aspect (10)).

It can also be used: In the above aspect (10), the aforementioned alkyl (meth)acrylate having a carbon number of 1 to 4 alkyl groups contains alkyl (meth)acrylate having a carbon number of 1 to 4 alkyl groups (but , Except for n-butyl acrylate) and n-butyl acrylate (pattern (11)).

And it can be used: In the above aspect (11), the monomer unit contains 4-60% by mass of the aforementioned alkyl (meth)acrylate having 1 to 4 alkyl groups (except for n-butyl acrylate). Outside) and 30% by mass or more of n-butyl acrylate.

And it can be used: In the above aspect (11), as the monomer unit, 15-60% by mass of the aforementioned alkyl acrylate with a carbon number of 1 to 4 alkyl (except n-butyl acrylate) and 30 Those with n-butyl acrylate with mass% or more (pattern (11A)).

And it can be used: In the above aspect (11), as the monomer unit, the monomer unit contains 5 to 15% by mass of the alkyl methacrylate having 1 to 4 alkyl groups and 70% by mass or more of n-butyl acrylate者(Form (11B)).

In addition, the aforementioned adhesive layer-attached optical film can be used: the aforementioned monomer (a) contains the aforementioned alkyl (meth)acrylate having a C1-C4 alkyl group and the aforementioned fluorine-containing monomer, and serves as the aforementioned monomer The body unit contains more than 30% by mass of the aforementioned alkyl (meth)acrylate with a carbon number of 1 to 4 alkyl groups and more than 25% by mass of a fluorine-containing monomer, and contains more than 30% by mass of n-butyl acrylate ( State (21)).

In addition, the aforementioned adhesive layer-attached optical film can be used: the aforementioned monomer (a) contains the aforementioned alkyl (meth)acrylate and acrylonitrile having a C1-C4 alkyl group, and contains as the aforementioned monomer unit 70% by mass or more of the aforementioned alkyl (meth)acrylate having a C1-C4 alkyl group and 5% by mass or more of acrylonitrile, and containing 70% by mass or more of n-butyl acrylate (aspect (22)) .

In addition, in the framed image display panel, the monomer (a) containing 70% by mass or more of the alkoxyalkyl (meth)acrylate (aspect (23)) can be used.

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

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

The present invention also relates to an image display panel, which is characterized by an optical film with an image display portion and the aforementioned adhesive layer. The aforementioned image display panel can be used in the following mode: the aforementioned optical film with adhesive layer passes through the adhesive layer of the optical film with adhesive layer and the adhesive layer is disposed on the visual side of the aforementioned image display part.

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

Invention effect The optical film with the adhesive layer of the present invention has an optical film with a thickness greater than a predetermined range, so it can prevent or to a certain extent prevent grease or emulsifiable concentrate from reaching and contacting the adhesive layer. In addition, in the optical film with an adhesive layer of the present invention, the adhesive layer is formed of an adhesive layer containing an acrylic polymer as a base polymer and a silane coupling agent, and the acrylic polymer uses a predetermined ratio The above-mentioned predetermined monomers can prevent the adhesive layer from peeling off the adherend due to swelling even when grease or cream components reach the adhesive layer in a humidified environment.

In addition, the optical film with an adhesive layer of the present invention is used as a polarizing film with a single-sided protective polarizing film with a transparent protective film (but no retardation film) on one side of the polarizer, and the aforementioned adhesive layer is provided on The single-sided protective polarizing film does not have the side of the transparent protective film. Therefore, even when the adhesive layer absorbs grease or emulsifiable concentrate in a humidified environment and swells, the side used to bond the adhesive layer is not With a transparent protective film, it can effectively prevent cracks in the transparent protective film. In addition, the aforementioned polarizer is a thin polarizer with a thickness of 10 μm or less, so the shrinkage of the polarizer in a humidified environment can be suppressed to be small, and the polarizer and the adhesive layer are not likely to peel off.

The form used to implement the invention Hereinafter, referring to the drawings, an image display panel to which the optical film with an adhesive layer of the present invention can be applied is described. In the following, the case of applying the optical film with an adhesive layer to an image display panel with a frame is described. For example, an image display panel with a frame to which an optical film with an adhesive layer of the present invention is applied is shown in the cross-sectional view of FIG. 1A, and has an image display panel A and an outer frame 5 located outside the end surface of the aforementioned image display panel A. The image display panel A has an image display portion 1 and an optical film 2, and the optical film 2 is disposed on the visual side of the image display portion 1 through an adhesive layer 3. FIG. 1A is a part of a cross-sectional view showing an example of an image display panel with a frame, showing one side edge. FIG. 1B is a top view of an image display panel with a frame to which the optical film with the adhesive layer of the present invention is applied. The outer frame 5 is provided via the elastic middle layer 4. The elastic middle layer 4 is arranged to be more protruding than the outermost surface a of the visual display side of the aforementioned image display panel A (optical film 2), and the outer frame 5 is arranged so as not to cover the elastic middle layer 4. From the viewpoint of narrowing the frame, expanding the display area, or preventing the penetration of moisture, grease or cream components, and preventing cracks from the end of the image display panel after reducing the overall thickness of the image display device, etc. It is suitable for use in the state where the end surface of the image display panel A is in contact with the elastic intermediate layer 4. The outer frame 5 can be fixed to the elastic middle layer 4 by an adhesive.

On the other hand, from the standpoint of the ease of manufacturing steps that allow the panel to be inserted into the frame body, the end surface of the image display panel A and the elastic intermediate layer 4 can be provided with a gap S as shown in FIG. FIG. 2B is a top view of an image display panel with a frame to which the optical film with the adhesive layer of the present invention is applied. The gap S should be designed in the range below 2000μm. When there is the aforementioned gap S, water, grease, or emulsifiable concentrate will easily penetrate into the gap S. However, the use of the framed image display panel of the present invention can suppress the adhesive even when placed in a humidified environment. The layer is peeling off. Regardless of whether there is a gap S, the end surface of the optical film 2 can be coated with acrylic resin, urethane resin, silicone resin, fluorine resin or the like.

In addition, an image display panel with a frame using an optical film with an adhesive layer of the present invention is shown in the cross-sectional view of FIG. 3A, and can be further applied to the aforementioned image display panel A in the aspect shown in FIG. 1A or FIG. 1B. The end face has an inner frame 6 on the innermost surface a of the inner side of the elastic intermediate layer 4. FIG. 3B is a top view of an image display panel with a frame to which the optical film with the adhesive layer of the present invention is applied. In this aspect, the aforementioned elastic middle layer 4 is also used in a more prominent aspect than the aforementioned inner frame 6. In the aspect shown in FIG. 3A, it is exemplified that a cavity 7 is provided between the end surface of the image display panel A and the elastic intermediate layer 4, but in the aspect shown in FIG. 3A, the image display can also be The end face of the panel A is in contact with the aforementioned elastic intermediate layer 4 for use. When the empty room 7 is set in the configuration shown in FIG. 3A, accessories (camera lens, cable, dimming sensor, face recognition sensor, etc.) can be arranged in the empty room 7 and separated The inner frame 6 above it functions. The inner frame 6 can be fixed to the outermost surface a of the image display panel A and the elastic intermediate layer 4 by an adhesive.

In addition, in the image display panel with a frame to which the optical film with the adhesive layer of the present invention is applied, the distance between the outermost surface a of the viewing side of the image display panel A (optical film 2) and the adhesive layer 3 t (corresponding to the thickness of the optical film 2) is set to 75 μm or more. If the aforementioned distance t is less than 75 μm, it will be difficult to suppress the peeling of the adhesive layer 3 in a humidified environment where there is a possibility that fats and oils or cream components may contact the aforementioned elastic intermediate layer. In view of suppressing peeling of the adhesive layer 3, the aforementioned distance t is preferably 100 μm or more, and more preferably 120 μm or more. On the other hand, if the aforementioned distance t becomes longer (that is, if the thickness of the optical film becomes thicker), the size shrinkage of the optical film in a humidified environment will increase, and there is a tendency for warping to occur easily. Therefore, the aforementioned distance t It is preferably 300 μm or less, and more preferably 250 μm or less. The aforementioned distance t corresponds to the thickness of the optical film, and the thickness of the optical film in the optical film with the adhesive layer of the present invention is 75 μm or more. On the other hand, the thickness is preferably 300 μm or less.

In addition, from the viewpoint of narrowing the frame of the frame-attached image display panel, the widths of the outer frame 5 and the elastic middle layer 4 are preferably small. The widths of the outer frame 5 and the elastic middle layer 4 are appropriately set according to the size of the image display panel A. Generally, the width of the outer frame 5 is less than 5 mm, preferably 0.5 to 5 mm, and preferably 0.5 to 3 mm. The width of the elastic intermediate layer 4 is less than 5 mm, preferably 0.5 to 5 mm, and preferably 0.5 to 3 mm. In addition, the inner frame 6 should also be smaller from the viewpoint of narrowing the frame. Generally speaking, the width of the inner frame 6 is preferably 1-20 mm, and preferably 1-15 mm. In addition, when the cavity 7 is installed, its width is preferably 1-20 mm, and more preferably 1-15 mm. With the inner frame 6, even when there are grease or cream components in contact with the elastic intermediate layer 4, the possibility of the components reaching and contacting the adhesive layer 3 will be reduced. Therefore, the width of the cavity 7 is appropriate It is 1mm or more.

In addition, in the aspect shown in FIG. 1A, the elastic intermediate layer 4 is used in a state that is more protruding than the outermost surface a on the viewing side of the image display panel A (optical film 2). In the aspect shown in FIG. 3A, it is used in a more prominent aspect than the inner frame 6 described above. With this protrusion, the image display panel can be prevented from directly contacting the body of the image display device. The height of the aforementioned protrusion is generally 0.5~5mm, and more preferably 0.5~3mm. In addition, the elastic intermediate layer 4 is provided on the entire outer side of the end surface of the image display panel A in the plan view shown in FIG. 1B and the plan view shown in FIG. 3B, but the present invention uses the elastic intermediate layer 4 for at least a part of it It is also valid under circumstances.

Moreover, as shown in FIGS. 1A, 2A, and 3A, a holding portion 41 for holding the image display panel A may be provided under the elastic intermediate layer 4. The aforementioned elastic intermediate layer 4 and the holding portion 41 may also be integrally formed. Among the widths of the holding portion 41, the width of the portion not in contact with the bottom of the elastic intermediate layer 4 is preferably 5 mm or less, and more preferably 3 mm or less, from the standpoints of narrow bezel and weight reduction. On the other hand, from the viewpoint of holding the aforementioned image display panel A, the width of the aforementioned holding portion 41 (the width of the portion not touching the bottom of the elastic intermediate layer 4) is preferably 0.1 mm or more, and more preferably 0.3 mm or more. 2 is an example of the holding portion 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, and the edge of the image display panel A is held by the holding portion 41 , And when setting the gap S, it is preferable to design such that the width of the holding portion 41 where it does not contact the bottom of the elastic intermediate layer 4 is longer than the width of the gap S.

As shown in FIG. 1B, FIG. 2B, and FIG. 3B, the elastic middle layer 4, the outer frame 5, and the inner frame 6 may be arranged in a frame shape. In addition, when the elastic intermediate layer 4 is used in a frame shape as shown in FIG. 4 (FIG. 4 is a plan view, the case where the elastic intermediate layer 4 is provided with the holding portion 41 is also described together), it can be used from the viewpoint of handling properties, etc. Omit part of the edge. Moreover, the inner side of the elastic intermediate layer 4 may have the convex part 42 for fitting in order to be fixed to a frame body. For example, in FIG. 4, two convex portions 42 are provided on each of the three sides tied inside the frame. The number of the aforementioned protrusions 42 can be arbitrarily set.

>Outer border, inner border> The outer frame is one that forms an outer frame on the outside of the end surface of the image display panel for protection, and generally, the one suitable for the image display panel can be used without special restrictions. The inner frame is the outermost surface of the end face protection of the aforementioned image display panel, and the one suitable for the image display panel can usually be used without any special restrictions.

>Elastic middle layer> The elastic intermediate layer is the same as the above-mentioned material for avoiding direct contact between the image display panel and the main body of the image display device. As long as it is a material that can alleviate the impact caused by the contact when the notebook computer is closed, there is no particular limitation. The material for forming the elastic intermediate layer can use, for example, nitrile rubber, fluorine rubber, urethane rubber, silicone rubber, ethylene propylene rubber, hydrogenated nitrile rubber, chloroprene rubber, acrylic rubber, etc. Rubber materials such as butyl rubber, chlorosulfonated polyethylene, epichlorohydrin rubber, and natural rubber. In addition, the material of the elastic intermediate layer may also 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 described 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 by a polarizing film alone, or a laminated optical film formed by combining a polarizing film with other films. The thickness of the aforementioned optical film (the same applies when it is a laminated optical film) is designed to satisfy 75 μm or more. On the other hand, it is preferable to design the aforementioned thickness to 300 μm or less.

"Polarizing Film" The polarizing film contained in the aforementioned optical film can be a single-sided protective polarizing film having a transparent protective film (but not including a retardation film) only on one side of the polarizer. In the single-sided protective polarizing film, the adhesive layer is provided on the side of the single-sided protective polarizing film that does not have the transparent protective film.

When the aforementioned adhesive layer is directly provided on the polarizer of the single-sided protective polarizing film, the layer composition (1) of the single-sided protective polarizing film and the adhesive layer is shown below. Layer composition (1): transparent protective film/polarizer/adhesive layer When the aforementioned adhesive layer is provided on a single-sided protective polarizing film via a retardation film, the layer composition (2) of the single-sided protective polarizing film and the adhesive layer is shown below. Layer composition (2): transparent protective film/polarizer/phase difference film/adhesive layer

The aforementioned polarizer is not particularly limited, and various polarizers can be used. Examples of polarizers include hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, and ethylene-vinyl acetate copolymer-based partially saponified films that adsorb iodine or dichroic dyes. Color materials and uniaxially stretched, and polyene-based oriented films such as dehydrated polyvinyl alcohol or dehydrated polyvinyl chloride. Among them, a polarizer composed of a dichroic substance such as a polyvinyl alcohol-based film and iodine is more suitable.

In addition, it is preferable to use a thin polarizer with a thickness of 10 μm or less as the polarizer. It is particularly suitable to use a thin polarizer for the aforementioned single-sided protective polarizing film. From the viewpoint of suppressing peeling of the adhesive layer due to grease or cream, the thickness of the polarizer is preferably 3 μm or more. In addition, from the viewpoint of suppressing dimensional shrinkage in a humidified environment, the thickness of the polarizer is preferably 10 μm or less. Thin polarizers with a thickness of 3 to 10 μm have less thickness variation, good visibility, and less dimensional changes, so they are excellent in durability, and can also be thinner in terms of the thickness of the polarizing film, which is preferable from these viewpoints.

As the material constituting the transparent protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture resistance, isotropy, etc. can be used. Specific examples of the thermoplastic resin may include cellulose resins such as cellulose triacetate, polyester resins, polyether resins, polycarbonate resins, polycarbonate resins, polyamide resins, polyimide resins, and polyamide resins. Olefin resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins and mixtures of these. In addition, on one side of the polarizer, the transparent protective film is bonded by the adhesive layer, and on the other side, the transparent protective film can use (meth)acrylic, urethane, or acrylic urethane Thermosetting resins such as ester-based, epoxy-based, and silicone-based resins or UV-curing resins.

The material of the aforementioned transparent protective film is preferably cellulose resin or (meth)acrylic resin. The (meth)acrylic resin is preferably a (meth)acrylic resin having a lactone ring structure. Examples of (meth)acrylic resins having a lactone ring structure include Japanese Patent Application Publication No. 2000-230016, Japanese Patent Application Publication No. 2001-151814, Japanese Patent Application Publication No. 2002-120326, and Japanese Patent Application Publication No. 2002-254544 A (meth)acrylic resin having a lactone ring structure described in JP 2005-146084 A, etc. In particular, cellulosic resins are more effective than (meth)acrylic resins in suppressing cracks in polarizers that have become a problem in single-sided protective films that have a transparent protective film on only one side of the polarizer. From this point of view, it is more effective. good. The thickness of the aforementioned transparent protective film is generally preferably 10-100μm, preferably 20-50μm, more preferably 30-50μm. Especially when cellulose resin is used as the material of the transparent protective film, controlling the thickness below 100 μm can suppress the size shrinkage in a humidified environment, which is preferable.

The aforementioned transparent protective film does not include a retardation film. The transparent protective film without retardation film shows "optically isotropic", meaning that the in-plane retardation Re(550) is 0nm~10nm, and the thickness direction retardation Rth(550) is -10nm~+ 10nm.

(Definition of terms and symbols) The definitions of terms and symbols in this manual are as follows. (1) Refractive index (nx, ny, nz) "Nx" is the refractive index in the direction where the in-plane refractive index is the largest (that is, the slow axis direction), "ny" is the refractive index in the direction orthogonal to the slow axis (that is, the fast axis direction) in the plane, and " 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 at 23°C with light of wavelength λnm. For example, "Re(450)" is the in-plane retardation of the film measured at 23°C with a wavelength of 450nm. Re(λ) can be obtained by the formula: Re=(nx-ny)×d when the thickness of the film is d(nm). (3) Phase difference in thickness direction (Rth) "Rth(λ)" is the retardation of the film in the thickness direction measured at 23°C with a wavelength of 550nm. For example, "Rth(450)" is the retardation of the film in the thickness direction measured at 23°C with a wavelength of 450nm. Rth(λ) can be obtained by formula: Rth=(nx-nz)×d when the film thickness is d(nm).

As long as the adhesive used for bonding the polarizer and the transparent protective film is optically transparent, various types of water-based, solvent-based, hot-melt adhesive-based, radical curing type, and cation curing type can be used without particular limitation. In the form of adhesives, only water-based adhesives or free radical hardening adhesives are more suitable.

≪Surface treatment layer≫ A surface treatment layer can also be provided on the outermost surface of the aforementioned optical film. The surface treatment layer can include functional layers such as a hard coat, an anti-reflection layer, an anti-adhesion layer, a diffusion layer, or an anti-glare layer. The surface treatment layer can be provided on the transparent protective film used for the polarizing film, and in addition, can be additionally provided on another substrate different from the aforementioned transparent protective film. As another substrate, the same thing as the aforementioned transparent protective film can be used. In addition, when a surface treatment layer is provided, a conventionally known adhesive layer or the like can be used to bond to the aforementioned polarizing film. The surface treatment layer is provided in the polarizing film of the optical film on the side opposite to the side where the adhesive layer is provided.

As a material for forming the hard coat layer provided as the surface treatment layer, for example, a thermoplastic resin, a material that can be cured by heat or radiation can be used. Examples of the aforementioned materials include radiation-curable resins such as thermosetting resins, ultraviolet-curing resins, and electron beam-curing resins. Among them, an ultraviolet-curable resin is suitable. The ultraviolet-curable resin can be cured by ultraviolet irradiation to efficiently form a cured resin layer with simple processing operations. The curable resins can include various resins such as polyester, acrylic, urethane, amide, silicone, epoxy, melamine, etc., and include these monomers and oligomers. , Polymers, etc. From the viewpoints of rapid processing speed and low heat loss to the substrate, radiation-curable resins, particularly ultraviolet-curable resins, are particularly suitable. Examples of UV-curable resins that can be suitably used include those having UV-polymerizable functional groups, including those having two or more functional groups, particularly acrylic monomers or oligomer components having 3 to 6 functional groups. . In addition, a photopolymerization initiator is blended in the ultraviolet curable resin.

Moreover, as for the aforementioned surface treatment layer, an anti-glare treatment layer or an anti-reflection layer for the purpose of improving visibility can be provided. Furthermore, an anti-glare treatment layer or an anti-reflection layer can be provided on the aforementioned hard coating layer. The constituent material of the anti-glare treatment layer is not particularly limited, and for example, radiation-curable resin, thermosetting resin, thermoplastic resin, etc. can be used. As the anti-reflection layer, titanium oxide, zirconium oxide, silicon oxide, magnesium fluoride, etc. can be used. The anti-reflection layer can be provided in multiple layers. In addition, the surface treatment layer may also include an anti-adhesion layer.

≪Other layers≫ On the aforementioned optical film (multilayer optical film), in addition to the aforementioned layers, a retardation film (including a 1/2 or 1/4 wavelength plate), a visual compensation film, etc. may be laminated. In addition, an anchor layer, an easy-to-bond layer, or various easy-to-bond treatments such as corona treatment and plasma treatment can be provided on the aforementioned polarizing film or other optical layer.

As shown in the layer configuration (2), the adhesive layer may be provided on a single-sided protective polarizing film via a retardation film. As the retardation film, for example, a birefringent film obtained by uniaxially or biaxially stretching a polymer material, an oriented film of a liquid crystal polymer, a film supporting an oriented layer of a liquid crystal polymer, etc. can be mentioned. These retardation films may be one layer alone or in combination or two or more layers.

When the optical film with adhesive layer is applied to the image display panel for PC, the retardation film should be placed between the polarizer and the image display from the viewpoint of viewing angle compensation and low reflectivity, and is compatible with the above transparent protection Film differentiation. In addition, the retardation film can generally be used with a thickness of 4 to 150μm, but from the viewpoint of suppressing peeling of the adhesive layer in a humidified environment or cracks in the retardation film, a thinner thickness within an appropriate range is more advantageous, for example The thickness (total) of the retardation film is 2~25μm, and 4~24μm is more preferable.

>Adhesive layer> The following describes the adhesive layer in the aforementioned adhesive layer-attached optical film. The adhesive layer is formed of the following adhesive composition, the adhesive composition contains a (meth)acrylic polymer (A) as a base polymer, and the (meth)acrylic polymer (A) contains 80% by mass or more of the monomer (a) is used as a monofunctional monomer unit, and the monomer (a) is selected from alkyl (meth)acrylates and alkyl (meth)acrylates having a C1-C4 alkyl group At least one of oxyalkyl ester, fluorine-containing monomer and acrylonitrile, and containing 20% by mass or more of n-butyl acrylate as the monomer unit, or 70% by mass or more of (methyl) Alkoxyalkyl acrylate. The aforementioned monofunctional monomer unit is a unit of a compound that constitutes the (meth)acrylic polymer (A) and has an unsaturated double bond such as a (meth)acryloyl group and a vinyl group. The (meth)acrylic polymer (A) includes a partial polymer containing the monomer component of the alkyl (meth)acrylate (a) and/or the (meth)acrylic polymer obtained from the monomer component polymer. In addition, (meth)acrylate refers to acrylate and/or methacrylate, and (meth) in the present invention also has the same meaning.

The main skeleton of the aforementioned (meth)acrylic polymer (A) is formed by a monomer (a) selected from the aforementioned alkyl (meth)acrylates having alkyl groups with 1 to 4 carbon atoms , At least one of alkoxyalkyl (meth)acrylate, fluorine-containing monomer and acrylonitrile. As the aforementioned monomer unit, the mass ratio of the aforementioned monomer (a) is in the mass ratio of the total constituent monomers (monofunctional monomer 100% by mass, the same below) constituting the (meth)acrylic polymer (A) , Is 80% by mass or more. By using the (meth)acrylic polymer (A) in the above ratio, it is possible to suppress the peeling of the adhesive layer due to grease or emulsifiable concentrate.

The alkyl group in the aforementioned alkyl (meth)acrylate having an alkyl group with 1 to 4 carbon atoms includes, for example, a linear or branched alkyl group, such as methyl, ethyl, propyl, and isopropyl. , N-butyl, isobutyl, tertiary butyl, etc.

The aforementioned alkyl (meth)acrylate having a carbon number of 1 to 4 alkyl groups is preferably an alkyl (meth)acrylate having a carbon number of 4 alkyl groups, and is particularly preferably n-butyl acrylate. The n-butyl acrylate system constitutes an essential monomer unit of the (meth)acrylic polymer (A), and the aforementioned monomer (a) may be constituted by only n-butyl acrylate. As the monomer unit, the mass ratio of n-butyl acrylate is 20 mass% or more in the mass ratio of the total monomers (monofunctional monomer 100% by mass) constituting the (meth)acrylic polymer (A) , By using the (meth)acrylic polymer (A) in the above ratio, it is possible to prevent the adhesive layer from peeling off due to oil or cream components. The aforementioned mass ratio of n-butyl acrylate can be used at 30% by mass or more, 40% by mass or more, 50% by mass or more can be used, 60% by mass or more can be used, and 70% by mass or more can be used, and can be used 80% by mass or more, and more preferably 90% by mass or more.

The alkoxyalkyl (meth)acrylate is not particularly limited, and the alkoxyalkyl group is preferably an alkoxyalkyl group with 3 to 25 carbon atoms in total. For example, the above-mentioned (meth)acrylic acid alkoxyalkyl ester can include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxypropyl (Meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, ethoxybutyl (meth)acrylate, etc., and others Examples include alkoxy polyalkylene glycols such as methoxy triethylene glycol (meth) acrylate, etc., and commercially available products include methoxy polyethylene glycol (meth) acrylate (Osaka Organic Chemical Industry Company made bisma MPE400A) and so on.

The above-mentioned fluorine-containing monomer is not particularly limited. Examples include radically polymerizable carbon-carbon double bonds such as (meth)acryloyl and vinyl groups, and at least one alkyl group with 3 to 10 carbon atoms substituted by a fluorine atom. By. For example, the fluorine monomer may 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-dodecafluoroheptane Acrylate, 1H-1-(trifluoromethyl)trifluoroethyl acrylate, 1H,1H,3H-hexafluorobutyl acrylate, 1,2,2,2-tetrafluoro-1-(trifluoro Meth) ethyl acrylate and the like. In addition, among the above-mentioned fluorine-containing monomers, those having a hydroxyl group are not included in the hydroxyl-containing monomer described below.

In addition, the aforementioned monomer (a) is selected from alkyl (meth)acrylates, alkoxyalkyl (meth)acrylates, fluorine-containing monomers, and acrylonitrile having a carbon number of 1 to 4 alkyl groups. At least one of them, but the aforementioned monomer (a) may all be composed of the aforementioned alkyl (meth)acrylate having an alkyl group with 1 to 4 carbon atoms (aspect (1)). In this aspect (1), it is preferable to contain 30% by mass or more of n-butyl acrylate as the aforementioned monomer unit. This aspect (1) is preferable from the viewpoint of heating and ensuring durability of wet heat.

Taking the above-mentioned monomer (a) using all the aforementioned alkyl (meth)acrylates having a carbon number of 1 to 4 alkyl (1), for example, all of the aforementioned monomer (a) can be composed of Formation of n-butyl acrylate (10). In this aspect (10), it is preferable to contain 70% by mass or more of n-butyl acrylate as the aforementioned monomer unit. At this time, although the aforementioned monomer units of n-butyl acrylate may vary depending on the types of comonomers, crosslinking agents, etc., they can be used at 80% by mass or more, 90% by mass or more, and 95% by mass or more. This aspect (10) is preferable from the viewpoint of heating and ensuring durability of wet heat.

In addition, in the aspect (1) in which the monomer (a) uses all the alkyl (meth)acrylates having a carbon number of 1 to 4 alkyl groups, for example, other than n-butyl acrylate can be used. In addition to n-butyl acrylate, the aforementioned alkyl (meth)acrylate with a carbon number of 1 to 4 is used in combination (11). In addition to n-butyl acrylate, the aforementioned alkyl (meth)acrylates with a carbon number of 1 to 4 alkyl groups are preferably alkyl (meth)acrylates with a carbon number of 1 to 3 alkyl groups and tertiary butyl acrylate . Alkyl (meth)acrylates with alkyl groups of 1 to 3 carbons are preferably methyl acrylate, methyl methacrylate, ethyl acrylate and other alkyl (meth)acrylates with alkyls of 1 to 2 carbons . That is, in the aspect (11) in which n-butyl acrylate and the aforementioned monomer (a) except for n-butyl acrylate are used in combination, the above-mentioned monomer (a) should preferably be a (methyl) group with a carbon number of 1 to 3 Alkyl acrylate or tertiary butyl acrylate, and n-butyl acrylate. This aspect (11) is preferable from the viewpoint of oil resistance, processability, handling properties, and crack resistance.

When it is the aspect (11) of the aforementioned combined system, the aforementioned mass ratio of the aforementioned alkyl (meth)acrylate having an alkyl group of 1 to 3 carbons is preferably 4-60% by mass, and preferably 4-50 % By mass, more preferably 10-40% by mass; on the other hand, the aforementioned mass ratio of n-butyl acrylate is preferably 30% by mass or more, preferably 30-96% by mass, more preferably 40-90 Mass%, and should be adjusted to a total of 80% by mass.

In addition, in the aspect (11) of the above-mentioned combined system, the alkyl (meth)acrylate (except n-butyl acrylate) having an alkyl group of 1 to 4 carbon atoms is used in the aspect in which alkyl acrylate is used In the case of (11A), the aforementioned mass ratio of the aforementioned alkyl acrylate is preferably 15-60% by mass, preferably 15-45% by mass, more preferably 20-40% by mass; on the other hand, n-butyl acrylate The aforementioned mass ratio of the ester is preferably 30% by mass or more, preferably 40 to 85% by mass, more preferably 40 to 75% by mass, and preferably adjusted to 80% by mass or more in total. This aspect (11A) is preferable from the viewpoint of oil resistance, workability, handling properties, and crack resistance.

In addition, in the aspect (11) of the above-mentioned combined system, the alkyl (meth)acrylate (except for n-butyl acrylate) having an alkyl group with carbon numbers of 1 to 4 uses one of alkyl methacrylate. In aspect (11B), the aforementioned mass ratio of the aforementioned alkyl methacrylate is preferably 5-15% by mass, and preferably 5-10% by mass; on the other hand, the aforementioned mass ratio of n-butyl acrylate is suitable It is set to 70% by mass or more, preferably 70 to 90% by mass, and preferably adjusted to a total of 80% by mass or more. This aspect (11B) is preferable from the viewpoint of workability, handling properties, and crack resistance.

In addition, the monomer (a) can be, for example, a form (21) in which the alkyl (meth)acrylate having a C1-C4 alkyl group and the fluorine-containing monomer are used in combination. When it is the aspect (21) of the aforementioned combined system, the aforementioned mass ratio of the aforementioned alkyl (meth)acrylate having a C1-C4 alkyl group is preferably 30% by mass or more, and preferably 30-55 mass %, and the fluorine-containing monomer should be 25% by mass or more, and 25-50% by mass, and should be adjusted to 80% by mass or more in total, and n-butyl acrylate should be adjusted to 30% by mass or more, more preferably Adjust to 30~55 mass%. This aspect (21) is preferable from the viewpoint of oil resistance.

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

In addition, the monomer (a) can be, for example, an aspect (23) in which 70% by mass or more of the aforementioned alkoxyalkyl (meth)acrylate is used. In the case of the aforementioned aspect (23), 80% by mass or more, 90% by mass or more, and 100% by mass of alkoxyalkyl (meth)acrylate can be used. In addition, in aspect (23), the aforementioned alkyl (meth)acrylate having an alkyl group with 1 to 4 carbon atoms may be used in combination. The aforementioned mass ratio of the aforementioned alkyl (meth)acrylate having an alkyl group of 1 to 4 carbon atoms is preferably 20% by mass or more, and the aforementioned alkoxyalkyl (meth)acrylate is preferably 70% by mass or more, It is better to be 70 to 99% by mass, and to be adjusted to a total of 80% by mass or more, and n-butyl acrylate is preferably adjusted to be 20% by mass or more. This aspect (23) is preferable from the viewpoint of high adhesion and oil resistance.

In addition, in the aspects (21) to (23) of the above-mentioned combined system, in the range of n-butyl acrylate or the aforementioned alkoxyalkyl (meth)acrylate that satisfies the aforementioned mass ratio, the aforementioned has a carbon number of 1 to 4 The alkyl (meth)acrylate of the alkyl group may use monomers other than n-butyl acrylate in combination. In particular, in the above aspect (21), in addition to n-butyl acrylate, the aforementioned alkyl (meth)acrylate having a carbon number of 1 to 4 alkyl groups may suitably use the aforementioned acrylic acid having a carbon number of 1 to 3 alkyl groups. The state of alkyl esters.

In addition, in order to improve adhesion and heat resistance, in addition to the monomer units of the aforementioned monomer (a), one or more types of (former) can be introduced into the (meth)acrylic polymer (A) by copolymerization. Base) A comonomer of a polymerizable functional group with unsaturated double bonds such as acrylic or vinyl. The aforementioned comonomer mass ratio is 20% by mass or less.

However, the alkyl (meth)acrylate having an alkyl group of 5 or more has a high polymerization ratio, which is not good from the viewpoint of suppressing the peeling of the aforementioned adhesive. Therefore, the (methyl) ) The polymerization ratio of alkyl acrylate is 20% by mass or less, preferably 15% by mass or less, and preferably 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less, and 1% by mass or less Best, not best.

As the aforementioned comonomer, for example, aromatic ring-containing (meth)acrylate can be used. Aromatic ring-containing (meth)acrylate is a compound containing an aromatic ring structure and a (meth)acryloyl group in its structure. Examples of the aromatic ring include a benzene ring, a naphthalene ring, or a biphenyl ring.

Specific examples of aromatic ring-containing (meth)acrylates include benzyl (meth)acrylate, phenyl (meth)acrylate, o-phenylphenol (meth)acrylate, and phenoxy (meth)acrylate , Phenoxyethyl (meth)acrylate, phenoxypropyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide modified nonphenol (meth)acrylate, Ethylene oxide modified cresol (meth)acrylate, phenol ethylene oxide modified (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, methoxybenzyl (Meth)acrylate, chlorobenzyl (meth)acrylate, cresol (meth)acrylate, polystyrene (meth)acrylate, etc., which have a benzene ring; hydroxyethylated β-naphthalene Phenol acrylate, 2-naphtholethyl (meth)acrylate, 2-naphthoxyethyl acrylate, 2-(4-methoxy-1-naphthoxy)ethyl (meth)acrylate, etc. have naphthalene Rings; (meth) acrylate and other biphenyls having a biphenyl ring.

From the viewpoint of adhesion properties and durability, the aforementioned aromatic ring-containing (meth)acrylates are preferably benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, and especially phenoxyethyl (meth)acrylate .

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

In addition, examples of the aforementioned comonomer include functional group-containing monomers such as hydroxyl group-containing monomers, carboxyl group-containing monomers, and amide group-containing monomers.

The hydroxyl-containing single system is a compound containing a hydroxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group and a vinyl group. Specific examples of hydroxyl-containing monomers include, for example, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyethyl (meth)acrylate Hydroxyhexyl ester, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate and other hydroxyalkyl (meth)acrylates or (4- Hydroxymethylcyclohexyl)-methacrylate and the like. From the viewpoint of durability, among the aforementioned hydroxyl-containing monomers, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred, and 4-hydroxybutyl (meth)acrylate is particularly preferred. .

The carboxyl group-containing single system is a compound that contains a carboxyl group in its structure and contains polymerizable unsaturated double bonds such as (meth)acrylic acid groups and vinyl groups. Specific examples of the carboxyl group-containing monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and the like. From the viewpoint of copolymerization, price, and adhesive properties, acrylic acid is preferred among the aforementioned carboxyl group-containing monomers.

The hydroxyl group-containing monomer and the carboxyl group-containing monomer become the reaction point of the crosslinking agent when the adhesive composition contains the crosslinking agent. Since the hydroxyl group-containing monomer and the carboxyl group-containing monomer have good reactivity with the crosslinking agent between molecules, it is preferable to use these monomers in order to improve the cohesiveness and heat resistance of the obtained adhesive layer.

The aforementioned mass ratio of the hydroxyl group-containing monomer is preferably 3% by mass or less, and preferably 0.01 to 3% by mass, more preferably 0.1 to 2% by mass, and more preferably 0.2 to 2% by mass. From the viewpoint of the cross-linked adhesive layer, durability, or adhesion characteristics, the mass ratio of the hydroxyl-containing monomer is preferably 0.01% by mass or more. On the other hand, when it exceeds 3% by mass, it is not good from the viewpoint of durability.

The aforementioned mass ratio of the carboxyl group-containing monomer is preferably 10% by mass or less, and is preferably 0.01-8% by mass, more preferably 0.05-6% by mass, and more preferably 0.1-5% by mass. The mass ratio of the carboxyl group-containing monomer is preferably 0.01% by mass or more from the viewpoint of durability.

Amino group-containing single system is a compound that contains an amide group in its structure and contains polymerizable unsaturated double bonds such as (meth)acrylic acid groups and vinyl groups. Specific examples of the amine group-containing monomer include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N -Isopropyl acrylamide, N-methyl (meth) acrylamide, N-butyl (meth) acrylamide, N-hexyl (meth) acrylamide, N-methylol (meth) acrylamide, Base) acrylamide, N-hydroxymethyl-N-propane (meth) acrylamide, aminomethyl (meth) acrylamide, aminoethyl (meth) acrylamide, mercaptomethyl (meth)acrylamide, Yl)acrylamide, mercaptoethyl (meth)acrylamide and other acrylamide monomers; N-(meth)acryloyl mopholin, N-(meth)acryloylpiperidine, N -(Meth)acryloylpyrrolidine and other N-acryloyl heterocyclic monomers; N-vinylpyrrolidone, N-vinyl-ε-caprolactam and other N-vinyl lactam-containing systems Monomer etc. The amide group-containing monomer can suppress the increase in surface resistance over time (especially in a humidified environment) or satisfy durability. In particular, among the amine group-containing monomers, an N-vinyl lactam-containing monomer is particularly preferable.

The aforementioned mass ratio of the amide group-containing monomer is large, and the anchoring property of the optical film tends to decrease. Therefore, the aforementioned mass ratio is preferably 10% by mass or less, and more preferably 5% by mass or less. From the viewpoint of suppressing the increase in surface resistance over time (especially in a humidified environment), it is preferably 0.1% by mass or more. The aforementioned mass ratio is preferably 0.3% by mass or more, and more preferably 0.5% by mass or more.

Specific examples of other comonomers other than the above include acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; allyl sulfonic acid, 2-(meth)acrylamide Sulfonic acid group-containing monomers such as methyl-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl(meth)acrylate; 2-hydroxyethylacryloyl phosphate, etc. Phosphoric acid group-containing monomers, etc.

In addition, examples of monomers for the purpose of modification include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, tertiary butylaminoethyl (meth) (Meth)acrylic acid esters and other (meth)acrylic acid alkylaminoalkyl esters; (meth)acrylic acid methoxyethyl, (meth)acrylic acid ethoxyethyl, and (meth)acrylic acid alkoxyalkyl groups Esters; N-(meth)acryloyloxymethylenesuccinimide or N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(meth)propylene Succinimidyl monomers such as octamethylene succinimidine such as octamethylene; N-cyclohexylmaleimide or N-isopropylmaleimide, N-laurylima Maleimines such as lyimines or N-phenylmaleimines; N-methylikonimines, N-ethylikonimines, N-butylimines Conimines, N-octyl iconimines, N-2-ethylhexyl iconimines, N-cyclohexyl iconimines, N-lauryl iconimines, etc. Amide-based monomers, etc.

In addition, as the modified monomer, vinyl monomers such as vinyl acetate and vinyl propionate can also be used; epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate; (meth)acrylic acid Glycol (meth)acrylate such as polyethylene glycol ester and polypropylene glycol (meth)acrylate; (meth)acrylic acid such as tetrahydrofurfuryl (meth)acrylate and polysiloxane (meth)acrylate Ester monomers, etc. More examples include isoprene, butadiene, isobutylene, vinyl ether, and the like.

In addition, the copolymerizable monomers other than the above may include silane-based monomers containing silicon atoms. As the silane-based monomer, for example, 3-propylene oxypropyl triethoxy silane, vinyl trimethoxy silane, vinyl triethoxy silane, 4-vinyl butyl trimethoxy silane, 4- Vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloxydecyltrimethoxysilane, 10-propylene Oxydecyl trimethoxysilane, 10-methacryloxydecyl triethoxysilane, 10-acryloxydecyl triethoxysilane, etc.

Among the mass ratios of the total constituent monomers (monofunctional monomer 100% by mass) of the aforementioned (meth)acrylic polymer (A), the aforementioned other comonomers in the (meth)acrylic polymer (A) The ratio is preferably about 0-10% by mass, preferably about 0-7% by mass, and more preferably about 0-5% by mass.

In addition, as a comonomer, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and bisphenol A can also be used. Diglycidyl ether di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, neopentylerythritol tri(meth)acrylate, Neopentyl erythritol tetra (meth) acrylate, dineopentaerythritol penta (meth) acrylate, dineopentaerythritol hexa (meth) acrylate, caprolactone modified dineopentaerythritol hexa ( Polyfunctional monomers such as esters of (meth)acrylic acid and polyols such as meth)acrylates, etc., have two or more (meth)acrylic acid groups, vinyl groups and other unsaturated double bonds, or in polyester, Polyester (meth)acrylates and cyclics in which two or more (meth)acrylic groups, vinyl groups, and other unsaturated double bonds are added to the backbone of epoxy, urethane, etc., as the same functional groups as the monomer components Oxygen (meth)acrylate, urethane (meth)acrylate, etc.

In the case of the aforementioned comonomer, when the aforementioned polyfunctional monomer or the like is used, the polyfunctional monomer functions as a crosslinking component. The usage amount of the above-mentioned polyfunctional monomers will vary depending on the molecular weight or the number of functional groups, etc. However, it is preferable to use 1 part by mass or less with respect to 100 parts by mass of the total of monofunctional monomers, and more preferably 0.5 parts by mass or less. Better. The lower limit is not particularly limited, but it is preferably 0 part by mass or more, preferably 0.01 part by mass or more. By using the multifunctional monomer in the aforementioned range, the adhesive force can be improved.

The (meth)acrylic polymer (A) of the present invention usually has a weight average molecular weight of 1 million to 2.5 million. Considering durability, especially heat resistance, the weight average molecular weight should be 1.2 million to 2 million. From the viewpoint of heat resistance, the weight average molecular weight is preferably 1 million or more. In addition, if the weight average molecular weight is more than 2.5 million, the adhesive tends to become hard and peel off easily. In addition, the weight average molecular weight (Mw)/number average molecular weight (Mn) showing the molecular weight distribution is preferably 1.8 or more and 10 or less, more preferably 1.8-7, and more preferably 1.8-5. If the molecular weight distribution (Mw/Mn) is greater than 10, it is not suitable from the viewpoint of durability. In addition, the weight average molecular weight and the molecular weight distribution (Mw/Mn) are measured in accordance with GPC (Gel Permeation Chromatography) and calculated in terms of polystyrene.

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

In addition, in solution polymerization, the polymerization solvent can be, for example, ethyl acetate, toluene, etc. As a specific example of solution polymerization, the reaction can be carried out under reaction conditions of about 50 to 70°C for about 5 to 30 hours by adding a polymerization initiator under an inert gas stream such as nitrogen.

The polymerization initiator, chain transfer agent, emulsifier, etc. used for radical polymerization can be appropriately selected and used without particular limitation. In addition, the weight average molecular weight of the (meth)acrylic polymer (A) can be controlled by the usage amount of the polymerization initiator and the chain transfer agent and the reaction conditions, and the usage amount can be appropriately adjusted according to the types of these.

In addition, the adhesive composition for forming the adhesive layer of the present invention contains a silane coupling agent (B) as an additive. By combining the aforementioned silane coupling agent (B) and the above-mentioned alkyl (meth)acrylate (a) with a carbon number of 1 to 4 alkyl groups containing 80% by mass or more as a monomer unit (meth)acrylic polymerization It can prevent the adhesive layer from peeling off due to oil or emulsifiable concentrate.

The aforementioned silane coupling agent (B) preferably uses at least one selected from the group consisting of epoxy group-containing silane coupling agent (b1) and mercapto group-containing silane coupling agent (b2).

The aforementioned epoxy-containing silane coupling agent (b1) can include, for example, 3-epoxypropylpropyltrimethoxysilane, 3-epoxypropylpropyltriethoxysilane, 3-epoxypropylpropyl Low-molecular-weight (non-oligomeric) epoxy-containing silane coupling agents such as methyldiethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or Shin-Etsu Chemical Industry The company produces X-41-1053, X-41-1056, X-41-1059A, X-24-9590, KR-516 and other oligomer type epoxy-containing silane coupling agents. In view of the great effect of inhibiting the peeling of the adhesive layer due to grease or emulsifiable concentrate, the aforementioned epoxy-containing silane coupling agent (b1) is preferably a low-molecular (non-oligomer type) epoxy-containing silane coupling agent .

In addition, the aforementioned mercapto group-containing silane coupling agent (b2) may include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3- Mercaptopropylmethyldiethoxysilane, β-mercaptomethylphenylethyltrimethoxysilane, mercaptomethyltrimethoxysilane, 6-mercaptohexyltrimethoxysilane, 10-mercaptodecyltrimethoxysilane Silane and other low molecular type (non-oligomer type) mercapto group-containing silane coupling agents, or X-41-1805, X-41-1810, X-41-1818 manufactured by Shin-Etsu Chemical Co., Ltd., etc. In view of the great effect of inhibiting the peeling of the adhesive layer due to grease or emulsifiable concentrate, the aforementioned mercapto group-containing silane coupling agent (b2) is preferably an oligomer type mercapto group-containing silane coupling agent.

In addition, the low-molecular-weight silane coupling agent (B) other than the above includes, for example, A100 made by Soken Chemical Co., Ltd. containing silane coupling agents such as acetylacetoxy groups; 3-aminopropyltrimethoxysilane, N-2-(amine Ethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine, N-phenyl-γ-aminopropyl Amino-containing silane coupling agents such as trimethoxysilane; 3-propenyloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. containing (meth)acrylic acid Silane coupling agent containing isocyanate groups; 3-isocyanate propyl triethoxy silane and other isocyanate group-containing silane coupling agents. In addition, examples of oligomer-type silane coupling agents other than the above include KR-213 manufactured by Shin-Etsu Chemical Co., Ltd. and the like.

The silane coupling agent having multiple alkoxysilyl groups in the molecule is ideal because it is not volatile and has multiple alkoxysilyl groups, so it can effectively improve durability. Especially when the adherend of the optical film with adhesive is a transparent conductive layer (such as ITO) that is less likely to react with alkoxysilyl than glass, the durability is still good. In addition, the so-called oligomer type refers to a polymer whose monomer is more than dimer and less than about 100 polymer, and the weight average molecular weight of the oligomer type silane coupling agent is preferably about 300 to 30,000.

The aforementioned silane coupling agent (B) can be used individually or in combination of two or more, but the total content is preferably 0.01-5 parts by mass relative to 100 parts by mass of the aforementioned (meth)acrylic polymer (A) , Preferably 0.02~3 parts by mass, more preferably 0.05~1 parts by mass, and more preferably 0.1~0.8 parts by mass. In addition, as mentioned above, the aforementioned silane coupling agent (B) is preferably at least one selected from the group consisting of epoxy-containing silane coupling agent (b1) and mercapto group-containing silane coupling agent (b2), and these silane coupling agents are used in combination When (b1) and (b2) are used with other silane coupling agents, with respect to 100 parts by mass of the aforementioned (meth)acrylic polymer (A), the other silane coupling agents may be 3 parts by mass or less and be compatible with the aforementioned silane coupling agent (B) Use the same amount or less.

The adhesive composition of the present invention may 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-based crosslinking agents, peroxide-based crosslinking agents, epoxy-based crosslinking agents, and imine-based crosslinking agents. Multifunctional metal chelate is a covalent bond or coordination bond between a multivalent metal and 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, and the like. Examples of atoms that can be covalently bonded or coordinately bonded in organic compounds include oxygen atoms, and organic compounds include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

The aforementioned crosslinking agent (C) is preferably an isocyanate-based crosslinking agent. As the isocyanate-based crosslinking agent, a compound having at least two isocyanate groups can be used. For example, well-known aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, etc. used in the urethane reaction are generally used.

Relative to 100 parts by mass of the (meth)acrylic polymer (A), the usage amount of the aforementioned crosslinking agent (C) is preferably 3 parts by mass or less, more preferably 0.01-3 parts by mass, more preferably 0.02-2 Parts by mass, and more preferably 0.03-1 parts by mass. On the other hand, when the crosslinking agent (C) is less than 0.01 parts by mass, the adhesive may not be sufficiently crosslinked to satisfy durability or adhesion characteristics; on the other hand, if it exceeds 3 parts by mass, the adhesive may become too hard The tendency to decrease durability.

In addition, the adhesive composition of the present invention may contain other well-known additives. For example, powders such as antistatic agents, colorants, pigments, dyes, surfactants, plasticizers, and tackifiers may be appropriately added according to the application. Agents, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, granules, foils, etc. In addition, an oxidation-reduction system with a reducing agent can also be used within a controllable range. These additives are preferably used in a range of 5 parts by mass or less, more preferably 3 parts by mass or less, and more preferably 1 part by mass or less with respect to 100 parts by mass of the (meth)acrylic polymer (A).

On the other hand, the adhesive composition of the present invention does not contain a polyether compound having a polyether skeleton and a reactive silicon group at at least one end. Examples of the aforementioned polyether compound having a reactive silicon group include those disclosed in Japanese Patent Application Laid-Open No. 2010-275522. The aforementioned reactive silicon-based polyether compound is preferable from the viewpoint of improving the reworkability, but it is not preferable from the viewpoint of suppressing the peeling of the adhesive layer due to grease or emulsifiable concentrate. When using the polyether compound having a reactive silicon group, even if the silane coupling agent (B) is used, the peeling of the adhesive layer cannot be suppressed.

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

The method of forming the aforementioned adhesive layer can be produced by, for example, the following method: applying the aforementioned adhesive composition to a release-treated separator, etc., and drying to remove the polymerization solvent, etc., to form an adhesive layer, and then transfer it to an optical film (Polarizing film) method; or a method of coating the aforementioned adhesive composition on an optical film (polarizing film) and then drying and removing the polymerization solvent to form an adhesive layer on the optical film. In addition, one or more solvents other than the polymerization solvent may be added appropriately when applying the adhesive.

The thickness of the aforesaid adhesive layer is not particularly limited, but if it is thinner, its adhesion to the image display part will decrease, or it will tend to peel off during heat shrinkage. On the other hand, if it is thicker, grease Or the emulsifiable concentrate component will be easily absorbed by the adhesive layer, causing easy peeling. Therefore, for example, it is preferably about 10-30 μm, and more preferably 15-20 μm.

The aforementioned adhesive layer usually has an oleic acid swelling degree of 100% by mass or more. The smaller the oleic acid swelling degree, the less the influence caused by oleic acid. According to the adhesive layer-attached optical film of the present invention, when the oleic acid swelling degree of the adhesive layer is greater than 130%, and when the swelling degree of oleic acid is more than 140%, and then is more than 150%, the grease or emulsifiable concentrate can be added to the adhesive layer. The impact is less suppressed. In addition, when the swelling degree of oleic acid of the adhesive layer is greater than 130%, the influence on other optical components after the adhesive layer absorbs grease or cream can be reduced. On the other hand, if the swelling degree of oleic acid of the adhesive layer increases, the influence of oil or emulsifiable concentrate on the adhesive layer will also increase. Therefore, the swelling degree of oleic acid should be 190% or less, and preferably 180% or less .

>Video Display Department> The image display part is an optical film (containing at least one polarizing film) and a part of the image display device forming the optical film with the adhesive layer. The image display device can include a liquid crystal display device, an organic EL (electroluminescence) display device, PDP (Plasma Display Panel), electronic paper, etc.

Examples of the aforementioned image display unit include liquid crystal cells used in liquid crystal display devices. The liquid crystal cell can use any type of liquid crystal cell such as TN type or STN type, π type, VA type, IPS type, etc.

>Image display panel> When forming an image display panel, in addition to the aforementioned optical films, other optical films can also be laminated according to the suitability of each configuration. For example, in a liquid crystal display panel, at least a polarizing film is arranged on the side opposite to the viewing side of the liquid crystal cell, and the polarizing film is not particularly limited. In addition, the aforementioned other optical films can be, for example, reflective plates or transmissive plates, retardation films (including 1/2 or 1/4 wavelength plates), viewing angle compensation films, brightness enhancement films, etc., which can be used to form liquid crystal display devices. Such as the optical layer. These can use 1 layer or 2 or more layers.

>Video display device> The formation of various image display devices such as the liquid crystal display device of the present invention can be performed according to conventional knowledge. It is formed by appropriately assembling the components such as the lighting system as needed and incorporating the driving circuit. Generally speaking, the liquid crystal display device is formed in the following way: the liquid crystal cell (the composition of the glass substrate/liquid crystal layer/glass substrate) and the polarizing films arranged on both sides of it and the lighting system according to the needs are properly assembled, and then Incorporate the drive circuit, etc. The aforementioned optical film is arranged on the viewing side, and other polarizing films are arranged on the other side. In addition, an appropriate liquid crystal display device such as a backlight or reflector used in a lighting system can be formed in the liquid crystal display device. In addition, when forming a liquid crystal display device, for example, a diffuser, an anti-glare layer, an anti-reflection film, a protective plate, a scallop array, a lens array sheet, a light diffuser, a backlight, and other appropriate parts can be arranged in a suitable position. Or more than 2 layers. Example

Hereinafter, the present invention will be specifically described with manufacturing examples and examples, but the present invention is not limited by these examples. As for the parts and% in each case, all are based on weight. Below, the room temperature storage conditions not specifically specified are 23°C and 65%RH.

>Measure the weight average molecular weight of the (meth)acrylic polymer (A)> The weight average molecular weight (Mw) of the (meth)acrylic polymer is measured by GPC (Gel Permeation Chromatography). Mw/Mn is also measured in the same way.・Analyzing device: Tosoh (Tosoh) Corporation, HLC-8120GPC ・Column: Tosoh Corporation, G7000H _XL +GMH _XL +GMH _XL・Column size: 7.8mmφ×30cm each, total 90cm ・Column temperature: 40℃・Flow rate: 0.8mL/min ・Injection volume: 100μL ・Eluent: Tetrahydrofuran ・Detector: Differential Refractometer (RI) ・Standard sample: Polystyrene

>modulated optical film> The optical films A and D used in the examples, comparative examples and reference examples were prepared in the following manner.

(Making thin polarizing parts) A non-crystalline isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100μm) substrate with a water absorption rate of 0.75% and a Tg75°C is corona treated on one side, and the corona The treated surface was coated at 25°C with a ratio of 9:1 containing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetyl acetyl modified PVA (polymerization degree 1200, acetyl acetyl alcohol) The degree of modification is 4.6%, the degree of saponification is 99.0 mol% or more, an aqueous solution made by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gohsefimer Z200") and dried to form a PVA-based resin layer with a thickness of 11 μm to produce a laminate. The resulting laminate was subjected to uniaxial extension of the free end 2.0 times in the longitudinal direction (long side direction) between rollers with different peripheral speeds in an oven at 120° C. (in-air auxiliary extension treatment). Next, the layered body was immersed in an insoluble bath (a boric acid aqueous solution obtained by mixing 4 parts of boric acid with respect to 100 parts of water) at a liquid temperature of 30°C for 30 seconds (insoluble treatment). Next, while immersing in a dyeing bath at a liquid temperature of 30°C, the iodine concentration and immersion time were adjusted so that the polarizing plate had a predetermined transmittance. In this example, it was immersed in an iodine aqueous solution obtained by mixing 0.2 part of iodine and 1.0 part of potassium iodide with respect to 100 parts of water for 60 seconds (dyeing treatment). Then, it was immersed in a crosslinking bath (a boric acid aqueous solution obtained by mixing 3 parts of potassium iodide and 3 parts of boric acid with respect to 100 parts of water with a liquid temperature of 30°C) for 30 seconds (crosslinking treatment). After that, while immersing the layered body in a boric acid aqueous solution at a liquid temperature of 70°C (an aqueous solution obtained by mixing 4 parts of boric acid and 5 parts of potassium iodide with respect to 100 parts of water), the laminate was moved vertically between rollers of different peripheral speeds. The direction (long side direction) is uniaxially stretched so that the total stretch magnification reaches 5.5 times (underwater stretch). Thereafter, the layered body was immersed in a washing bath (an aqueous solution obtained by mixing 4 parts of potassium iodide with respect to 100 parts of water with a liquid temperature of 30°C) (washing treatment). In the above manner, an optical thin film laminate including a polarizer having a thickness of 5 μm was obtained.

(Transparent protective film) Acrylic film 1: A (meth)acrylic resin film with a lactone ring structure with a thickness of 40 μm is used after corona treatment is applied to the easy-adhesive surface. TAC film: Tri-cellulose acetate film with a thickness of 40µm is saponified and used. COP film 1: Cycloolefin resin film with a thickness of 13 μm (trade name: ZF14-013, manufactured by ZEON Co., Ltd.) was used. COP film 2: Cycloolefin resin film with a thickness of 25 μm (trade name: ZF14-013, manufactured by ZEON Co., Ltd.) was used. The above-mentioned transparent protective films all show "optically isotropic", the in-plane phase difference Re(550) is 0nm~10nm, and the thickness direction phase difference Rth(550) is -10nm~+10nm.

(Manufacture of adhesives for transparent protective films) Acrylic oligomer formed by polymerizing 10 parts of N-hydroxyethyl acrylamide, 30 parts of acrylate mopholin, 45 parts of 1,9-nonanediol diacrylate, and (meth)acrylic monomer (ARUFONUP1190, manufactured by Toagosei Co., Ltd.), 3 parts of photopolymerization initiator (IRGACURE 907, manufactured by BASF), and 2 parts of polymerization initiator (KAYACURE DETX-S, manufactured by Nippon Kayaku Co., Ltd.) were mixed to prepare UV curable adhesive.

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

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

>Single-side protective polarizing film> On the surface of the polarizer of the above-mentioned optical film laminate, the above-mentioned transparent adhesive is laminated while applying the above-mentioned ultraviolet curable adhesive a so that the thickness of the adhesive layer after curing becomes 1μm After the protective film (thickness 40 μm: acrylic film 1 or TAC film), ultraviolet rays are irradiated as active energy rays to cure the adhesive. Ultraviolet rays are irradiated using a gallium-filled metal halide lamp, irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak illuminance: 1600mW/cm ² , cumulative irradiation amount 1000/mJ/cm ² (wavelength 380~440nm), and the ultraviolet illuminance is measured using the Sola-Check system manufactured by Solarell. Then, the amorphous PET substrate was peeled off to prepare a single-sided protective polarizing film with a thickness of 46 μm using a thin polarizer. The single-sided protective polarizing film 1 using the aforementioned acrylic film 1 is used to prepare the following single-sided protective polarizing film with retardation film. When the aforementioned TAC film is used, it is directly used as the single-sided protective polarizing film 2.

>Single-side protective polarizing film with retardation film> A first retardation film and a second retardation film were sequentially laminated on the thin polarizer side of the single-sided protective polarizing film 1 to obtain a 72 μm thick single-sided protective polarizing film with retardation film. The bonding system is the same as the above, and an ultraviolet curable adhesive a is used to form an adhesive layer with a thickness of 1 μm. In addition, the slow axis of the laminated first retardation film is 0° with respect to the absorption axis of the polarizer, and the slow axis of the second retardation film is 90° with respect to the absorption axis of the polarizer.

>Preparation of double-sided protective polarizing film> On the surface of the polarizer of the above-mentioned optical film laminate, the above-mentioned ultraviolet curable adhesive a is applied so that the thickness of the cured adhesive layer becomes 1μm, and the above-mentioned After the COP film 1 (thickness 25 μm), ultraviolet rays were irradiated as active energy rays to cure the adhesive. Ultraviolet rays are irradiated using a gallium-filled metal halide lamp, irradiation device: Light HAMMER10 manufactured by Fusion UV Systems, Inc., bulb: V bulb, peak illuminance: 1600mW/cm ² , cumulative irradiation amount 1000/mJ/cm ² (wavelength 380~440nm), and the ultraviolet illuminance is measured using the Sola-Check system manufactured by Solarell. Next, the amorphous PET substrate was peeled off, and the COP film 2 (thickness 13μm) was bonded on the peeling surface with the above-mentioned adhesive, and then cured in the same way to produce a double-sided thin polarizer with a thickness of 45μm. Protect the polarizing film.

>Production of film with surface treatment layer: ARTAC: thickness 44μm> A cellulose triacetate film with a thickness of 40 μm was sputtered to form an anti-reflection layer with a thickness of 4 μm.

>Making a film with surface treatment layer: ARTAC: thickness 84μm> A cellulose triacetate film with a thickness of 80 μm was sputtered to form an anti-reflection layer with a thickness of 4 μm.

>Production of film with surface treatment layer: LCTAC (thickness 42μm)> A cellulose triacetate film with a thickness of 40 μm was coated to form a liquid crystal retardation layer with a thickness of 2 μm.

>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 fed into a 4-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a cooler. With respect to 100 parts of the aforementioned monomer mixture (solid content), 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator and 100 parts of ethyl acetate were fed together, and nitrogen was introduced while slowly stirring. After the nitrogen substitution, the liquid temperature in the flask was maintained at around 55°C, and the polymerization reaction was performed for 8 hours to prepare a solution of acrylic polymer with a weight average molecular weight (Mw) of 1.6 million.

(Preparation of adhesive composition) With respect to 100 parts of the solid content of the acrylic polymer solution obtained above, 0.45 parts of an isocyanate-based crosslinking agent (Coronate L manufactured by Tosoh Corporation, trimethylolpropane toluene diisocyanate) was blended to prepare acrylic Solution of adhesive composition.

(Form an adhesive layer) Next, so that the thickness of the adhesive layer after drying becomes 23 μm or 12 μm, the solution of the acrylic adhesive composition is applied to the polyethylene terephthalate film treated with a silicone release agent ( Separating film: one side of Mitsubishi Chemical Polyester Film Co., Ltd., MRF38), and drying at 155°C for 1 minute, and an adhesive layer A is formed on the surface of the separating film.

The above-mentioned polarizing film and a film with a surface treatment layer were laminated with the following composition to prepare optical films A to F. The above-mentioned lamination is performed by bonding through the adhesive layer A on the triacetyl cellulose film side of the film with the surface treatment layer. The laminated layer of the aforementioned single-sided protective polarizing film with retardation film is bonded to the acrylic film 1 side with the adhesive layer A. The laminated layer of the aforementioned single-sided protective polarizing film 2 is bonded to the adhesive layer A on the TAC film side. The laminated layer of the aforementioned double-sided protective polarizing film is bonded to the adhesive layer A on the COP film 2 side. Optical film A (total thickness 128μm): ARTAC (thickness 44μm)/adhesive layer A (thickness 12μm)/single-side protective polarizing film with retardation film (thickness 72μm). Optical film B (total thickness 179μm): ARTAC (thickness 84μm)/adhesive layer A (thickness 23μm)/single-side protective polarizing film with retardation film (thickness 72μm). Optical film C (total thickness 244μm): ARTAC (thickness 84μm)/adhesive layer A (thickness 23μm)/LCTAC (thickness 42μm)/adhesive layer A (thickness 23μm)/single-side protective polarizing film with retardation film ( Thickness 72μm). Optical film D (total thickness 72μm): single-sided protective polarizing film with retardation film (thickness 72μm). 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)/double-sided protective polarizing film (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)/single-side protective polarizing film 2 (thickness 72 μm).

Example 1 (Preparation of acrylic polymer) A four-necked flask equipped with a stirring blade, a thermometer, a nitrogen introduction tube, and a cooler was fed with a monomer mixture containing 81.9 parts of n-butyl acrylate, 13.2 parts of benzyl acrylate, 0.1 part of 4-hydroxybutyl acrylate, and 4.8 parts of acrylic acid . With respect to 100 parts of the aforementioned monomer mixture (solid content), 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator and 100 parts of ethyl acetate were fed together, and nitrogen was introduced while slowly stirring. After the nitrogen substitution, the liquid temperature in the flask was maintained at around 55°C, and the polymerization reaction was performed for 8 hours to prepare a solution of acrylic polymer with a weight average molecular weight (Mw) of 1.6 million.

(Preparation of adhesive composition) With respect to 100 parts of the solid content of the acrylic polymer solution obtained above, 0.2 part of an oligomer type mercapto group-containing silane coupling agent (X-41-1810 manufactured by Shin-Etsu Chemical Co., Ltd.) and an isocyanate-based crosslinking agent ( Tosoh Corp. Coronate L, 0.45 parts of trimethylolpropane toluene diisocyanate), to prepare a solution of an acrylic adhesive composition.

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

(Preparation of optical film with adhesive layer and production of image display panel) Prepare the image display part (including the 15-inch diagonal liquid crystal cell: thickness 300μm). The adhesive layer B prepared above is attached to the single-sided protective polarizing film side of the retardation film of the prepared optical film A, and the optical film with the adhesive layer is prepared (the short side and the long side are more than the above The liquid crystal cell is 4mm short polarizing film). After peeling the release film from the optical film with the adhesive layer, the optical film A (the second retardation film side) was bonded to the optical film A (the second retardation film side) through the adhesive layer B on the visible side of the image display section. Display the image display panel (liquid crystal display panel). Next, autoclave treatment was performed at 50°C and 0.5 MPa for 15 minutes to completely adhere the optical film A to the image display portion. Then, the obtained image display panel is laser-cut into a 15-inch size.

(Making an image display panel with border) Prepare a rubber molding with a width of 1mm and a height of 5mm, which is processed according to the outer edge of the aforementioned image display panel (15-inch size) (the total width of the holding part is 1.5mm, and there are 6 convex parts, as shown in Figure 4, of which 1 The elastic middle layer is 5 cm from both sides) as the elastic middle layer. In addition, prepare a resin plate (frame) with a width of 1mm and a height of 3mm formed by the above-mentioned image display panel (15-inch size) as the outer frame (integrated with a concave frame that can be inserted into the panel) ). Install the aforementioned elastic intermediate layer to the frame where the aforementioned outer frame has been integrated, and then integrate the aforementioned image display panel (set the gap to be 1mm or less), and fabricate the outer side of the end surface of the aforementioned image display device with the aforementioned elastic The middle layer and the outer frame form the framed image display panel with the structure shown in Figure 2 (Figure 2A, Figure 2B). In the obtained framed image display panel, the elastic middle layer was set to protrude 1 mm from the outermost surface of the aforementioned image display panel (optical film A) on the viewing side. The aforementioned elastic intermediate layer is a structure in contact with the end surface of the aforementioned image display panel. The outer frame is fixed to the elastic middle layer by an adhesive.

Examples 2~32 and Comparative Examples 1~8 In Example 1, the composition or ratio of the monomer mixture used to prepare the acrylic polymer, the type or blending amount of the silane coupling agent used to prepare the adhesive composition, the type or blending amount of the crosslinking agent, or the formation The thickness of the adhesive layer was changed as shown in Table 1, except that the adhesive layer B was formed in the same manner as in Example 1. In addition, using the adhesive layer B obtained above and the optical films A and F shown in Table 1, the optical film with the adhesive layer was prepared in the same manner as in Example 1, and then an image display panel was produced. In addition, an image display panel with a frame was manufactured in the same manner as in the first embodiment. In addition, when the optical film E is used, the adhesive layer B is attached to the side of the double-sided protective polarizing film to prepare an optical film with the adhesive layer, and when the optical film F is used, it is attached to the side of the single-sided protective polarizing film 2 The adhesive layer B is combined to prepare an adhesive layer-attached optical film.

However, in Example 30, the framed image display panel with the structure shown in FIG. 3 (FIG. 3A, FIG. 3B) was produced. In the framed image display panel, a resin plate (frame) with a width of 20mm and a height of 2mm formed according to the image display panel (15-inch size) is prepared as the inner frame and assembled as the inner frame. The elastic middle layer is set to have a 15mm gap with the end surface of the aforementioned image display panel. The outer frame and the aforementioned elastic middle layer are used to ensure the size of the aforementioned gap. The outer frame is fixed to the elastic middle layer by an adhesive. The inner frame is fixed to the end of the outermost surface of the image display panel and the elastic middle layer by an adhesive.

In addition, the adhesive composition used in the formation of the adhesive layer of Comparative Example 3 was prepared by the following method. In a monomer mixture composed of 67 parts of 2-ethylhexyl acrylate (2EHA), 15 parts of 2-hydroxyethyl acrylate (HEA) and 18 parts of N-vinyl-2-pyrrolidone (NVP), As a photopolymerization initiator, 0.050 parts of 1-hydroxycyclohexyl phenyl ketone (trade name: IRGACURE184, manufactured by BASF), 2,2-dimethoxy-1,2-diphenylethan-1-one ( Trade name: IRGACURE651, manufactured by BASF Corporation) 0.050 parts, irradiated with ultraviolet rays until the viscosity (measurement conditions: BH viscometer No. 5 rotor, 10rpm, measurement temperature 30°C) reaches about 20 Pa·s, and the monomer composition is prepared Part of the polymerized prepolymer composition (polymerization rate: 9%). Next, 0.09 part of hexanediol diacrylate (HDDA) was added to this prepolymer composition and mixed, and the adhesive composition was obtained. The adhesive composition was coated on the peel-off treated surface of the release film (trade name "MRF#38", manufactured by Mitsubishi Plastics Corporation) so that the thickness became 20μm to form an adhesive composition layer . Then, the surface of another adhesive composition layer and the peeled-off surface of the release film ("MRN#38", manufactured by Mitsubishi Plastics Co., Ltd.) were bonded together, and the illuminance: 4mW/cm ² , light intensity: 1200mJ Under the condition of /cm ² , ultraviolet light is irradiated to harden the light to form an adhesive layer and make an adhesive sheet.

Reference example 1 (Making cover glass and image display panel with frame) Using the same image display panel as the image display panel modulated in Example 1, a framed image display panel with the structure shown in FIG. 5 was produced. The outer frame is the same thing as that used in Example 1. The cover glass is prepared according to the above-mentioned image display panel (15-inch size) and formed into a strengthened glass with a thickness of 1500 μm. All of the outer frame is installed on the outer side of the end surface of the image display panel and assembled. The outer frame is fixed to the image display panel by an adhesive. The aforementioned cover glass is bonded by an adhesive layer (LUCIACS CS9864 manufactured by Nitto Denko Corporation).

The following evaluations were performed on the optical film with an adhesive layer and the image display panel with a frame obtained in the above embodiments, comparative examples and reference examples. The evaluation results are listed in Table 1.

>Drug test during humidification> Use a 2 mL dropper to drip 10 mL of the following medicine on the inner side (all) of the elastic middle layer (the outer frame in the reference example) of the obtained framed image display panel. Oleic acid: Oleic acid produced by Wako Pure Chemicals Co., Ltd. (level 1, containing 65%). Vaseline moisturizing milk: UJ body lotion COAB made by Unilever (contains 63% water and 26% glycerin) Sunscreen: EDGEWELL PERSONAL CARE Banana Boat Sunscreen Lotion SPF 30. After dropping the medicine, store the framed image display panel at 65℃90%RH for 72 hours, then place it at normal temperature (23℃). Then, the optical film with the adhesive layer was taken out from the image display panel with the frame, the appearance was observed with naked eyes, and the peeling of the adhesive layer B was evaluated according to the following criteria. (Assessment criteria) ◎: No peeling. ○: No peeling, and the end swelled due to swelling of the glue. △: Tiny peeling under 0.5mm. NG: There is peeling (the peeling: mm is also described in Table 1).

>Determination of swelling degree of oleic acid> The adhesive layer B formed on the surface of the separation film used in each example was cut into a size of 20 mm×40 mm, and then a sample was made and its mass was measured (W1). Next, the aforementioned sample was immersed in oleic acid at 60°C and a humidity of 90% for 24 hours. The sample was removed from the oleic acid, and the surface of the sample was washed with ethanol, and then dried at 110°C for 3 hours. The mass (W3) of the dried sample is measured, and the oleic acid swelling rate of the acrylic adhesive is calculated using the following formula (2). The quality (W2) of the separation film of the sample is measured separately. Swelling rate (%)=((W3-W2)/(W1-W2))×100

>Crack resistance> In the same way as the above> Drug test during humidification>, use a 2 mL dropper to drop 10 mL of oleic acid on the inner side (all) of the elastic middle layer of the framed image display panel (in the reference example, the outer frame). After dropping the medicine, store the framed image display panel at 65℃90%RH for 72 hours, then place it at normal temperature (23℃). After that, take out the optical film with the adhesive layer from the image display panel with the frame, and set the adhesive layer of the optical film with the adhesive layer on the lower side, and observe it with the naked eye with a microscope (10 times) from the upper side. Whether the transparent protective film of the polarizing film has cracks (whether there are cracks and looks white). In addition, in Comparative Example 8 (an example using a double-sided protective polarizing film), the side surface of the optical film with the adhesive layer removed was observed with the naked eye. When viewed from the side, as long as one of the transparent protective films on both sides of the polarizer is cracked, it is evaluated as cracked.

[Table 1]

Table 1 shows as follows: 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, MEA: Methoxyethyl acrylate, SAT10: SAT10 made by Kaneka, KBM403: KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd., KBM573: KBM-573 manufactured by Shin-Etsu Chemical Co., Ltd., A100: A100 made by Soken Chemical Co., Ltd. (silicone coupling agent containing acetyl acetyl group), X-41-1810: oligomer type sulfhydryl-containing silane coupling agent manufactured by Shin-Etsu Chemical Industry Co., Ltd., X-41-1056: Oligomer type epoxy-containing silane coupling agent manufactured by Shin-Etsu Chemical Industry Co., Ltd., C/HX: isocyanate-based crosslinking agent (CORONATE HX manufactured by Tosoh, hexamethylene diisocyanate trimeric isocyanate), TETRAD C: Epoxy crosslinking agent (TETRAD C/1,3-bis(N,N-glycidylaminomethyl)cyclohexane manufactured by Mitsubishi Gas Chemical Corporation), C/L: isocyanate crosslinking agent (CORONATE L manufactured by Tosoh, trimethylolpropane toluene diisocyanate), D160N: isocyanate crosslinking agent (Takenate D160N manufactured by Mitsui Chemicals Co., Ltd., trimethylolpropane hexamethylene diisocyanate) 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 middle layer 5: Outer border 6: Internal border 7: Empty room 8: Adhesive layer (cover glass side) 9: Cover glass 41: holding part 42: convex S: gap a: the most surface t: distance

1A is a part of a cross-sectional view showing an example of an image display panel with a frame to which the optical film with an adhesive layer of the present invention can be applied. FIG. 1B is a top view showing an example of the framed image display panel of FIG. 1A. 2A is a part of a cross-sectional view showing an example of an image display panel with a frame to which the optical film with an adhesive layer of the present invention can be applied. FIG. 2B is a top view showing an example of the framed image display panel of FIG. 2A. 3A is a part of a cross-sectional view showing an example of an image display panel with a frame to which the optical film with an adhesive layer of the present invention can be applied. FIG. 3B is a top view showing an example of the framed image display panel of FIG. 3A. Fig. 4 is a plan view showing an example of a frame-shaped elastic intermediate layer. FIG. 5 is a part of a cross-sectional view showing an example of the framed image display panel of the comparative example.

A: Image display panel

1: Image display section

2: Optical film (including polarizing film)

3: Adhesive layer (image display side)

4: Elastic middle layer

5: Outer border

41: holding part

a: the most surface

t: distance

Claims (23)

An optical film with adhesive layer, with optical film and adhesive layer; The optical film with adhesive layer is characterized by: The thickness of the aforementioned optical film is 75μm or more; The aforementioned optical film includes a single-sided protective polarizing film, the single-sided protective polarizing film has a transparent protective film on one side of a polarizer with a thickness of 10 μm or less (but does not contain a retardation film), and the adhesive layer is provided on the aforementioned single side Protect the side of the polarizing film that does not have the aforementioned transparent protective film; The aforementioned adhesive layer is formed by the following adhesive composition: The adhesive composition contains a (meth)acrylic polymer (A) as a base polymer, and the (meth)acrylic polymer (A) contains 80% by mass or more of monomer (a) as a monofunctional monomer The monomer (a) is selected from alkyl (meth)acrylates, alkoxyalkyl (meth)acrylates, fluorine-containing monomers and acrylonitrile with a carbon number of 1 to 4 alkyl groups Any at least one, and contains 20% by mass or more of n-butyl acrylate or 70% by mass or more of alkoxyalkyl (meth)acrylate as a monofunctional monomer unit, And contains silane coupling agent (B), and It does not contain polyether compounds with a polyether skeleton and reactive silicon groups at at least one end. The optical film with an adhesive layer of claim 1, wherein the adhesive layer is provided on a single-sided protective polarizing film via a retardation film. Such as the optical film with adhesive layer of claim 1, wherein the adhesive layer is directly provided on the polarizer of the single-sided protective polarizing film. The optical film with an adhesive layer according to any one of claims 1 to 3, wherein the optical film has a surface treatment layer on the outermost surface of the optical film on the viewing side. The optical film with an adhesive layer according to any one of claims 1 to 4, wherein the thickness of the aforementioned optical film is 300 μm or less. The optical film with an adhesive layer according to any one of claims 1 to 5, wherein the thickness of the adhesive layer is 10-30 μm. The optical film with an adhesive layer according to any one of claims 1 to 6, wherein the oleic acid swelling degree of the adhesive layer is greater than 130% and less than 190%. The optical film with an adhesive layer according to any one of claims 1 to 7, wherein the aforementioned monomer (a) is all the aforementioned alkyl (meth)acrylate having an alkyl group of 1 to 4 carbons, and serves as the aforementioned The monomer unit contains more than 30% by mass of n-butyl acrylate. The optical film with an adhesive layer of claim 8, wherein the alkyl (meth)acrylate having a carbon number of 1 to 4 is all n-butyl acrylate, and the monomer unit contains 70% by mass or more The n-butyl acrylate. For example, the optical film with adhesive layer of claim 8, wherein the aforementioned alkyl (meth)acrylate having a carbon number of 1 to 4 alkyl groups contains alkyl (meth)acrylate having a carbon number of 1 to 4 alkyl groups (Except for n-butyl acrylate) and n-butyl acrylate. For example, the optical film with an adhesive layer of claim 10, which contains 4-60% by mass of the aforementioned alkyl (meth)acrylate having a carbon number of 1 to 4 alkyl groups as the aforementioned monomer unit (except for normal acrylic acid Butyl acrylate) and 30% by mass or more of n-butyl acrylate. For example, the optical film with adhesive layer of claim 10, which contains 15-60% by mass of the aforementioned alkyl acrylate having a carbon number of 1 to 4 alkyl groups as the aforementioned monomer unit (except for n-butyl acrylate) With 30% by mass or more of n-butyl acrylate. For example, the optical film with an adhesive layer of claim 10, wherein the monomer unit contains 5 to 15% by mass of the alkyl methacrylate having 1 to 4 alkyl groups and 70% by mass or more of normal acrylic acid Butyl ester. The optical film with an adhesive layer according to any one of claims 1 to 7, wherein the aforementioned monomer (a) contains the aforementioned alkyl (meth)acrylate having a C1-C4 alkyl group and the aforementioned fluorine-containing monomer As the aforementioned monomer unit, it contains more than 30% by mass of the aforementioned alkyl (meth)acrylate having 1 to 4 alkyl groups and more than 25% by mass of fluorine-containing monomer, and contains more than 30% by mass N-Butyl acrylate. The optical film with an adhesive layer according to any one of claims 1 to 7, wherein the aforementioned monomer (a) contains the aforementioned alkyl (meth)acrylate having an alkyl group of 1 to 4 carbon atoms and acrylonitrile, and The monomer unit contains 70% by mass or more of the alkyl (meth)acrylate having a carbon number of 1 to 4 alkyl groups and 5% by mass or more of acrylonitrile, and contains more than 70% by mass of n-butyl acrylate. The optical film with an adhesive layer according to any one of claims 1 to 7, wherein the monomer (a) contains 70% by mass or more of the alkoxyalkyl (meth)acrylate. The optical film with an adhesive layer according to any one of claims 1 to 16, wherein the aforementioned silane coupling agent (B) is selected from the group consisting of epoxy group-containing silane coupling agent (b1) and mercapto group-containing silane coupling agent (b2) At least one of them. Such as the optical film with adhesive layer of claim 17, wherein the aforementioned epoxy group-containing silane coupling agent (b1) is a low molecular type epoxy group-containing silane coupling agent (b1). The optical film with an adhesive layer according to claim 17 or 18, wherein the aforementioned 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 19, wherein the adhesive composition contains a crosslinking agent. An image display device, characterized in that it has an image display portion and an optical film with an adhesive layer as claimed in any one of claims 1-20. The image display panel of claim 21, wherein the optical film with the adhesive layer is disposed on the visual side of the image display part through the adhesive layer of the optical film with the adhesive layer. An image display device having an image display panel as in claim 21 or 22.

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