KR101501794B1 - Composite polarizing plate, laminated optical member, and image display device using them - Google Patents

Abstract

A composite polarizing plate having a polarizer, a retarder, and a pressure-sensitive adhesive layer is made thin and lightweight, and the brightness of the image display device to which the polarizer is applied is ensured, making it difficult to cause blurring or unclearness on the display. A transparent protective layer 2 is disposed on one surface of a polarizer 1 made of a polyvinyl alcohol based resin film and a second pressure sensitive adhesive layer 6 is provided on the other surface of the polarizer 1, And the second pressure sensitive adhesive layer 7 is disposed on the outer side of the retarder located farthest from the polarizer 1 to form a composite polarizing plate 11. [ At least one of the pressure-sensitive adhesive layers existing between the first pressure-sensitive adhesive layer (6) and the second pressure-sensitive adhesive layer (7) contains a light-diffusing agent and has a storage elastic modulus Sensitive pressure-sensitive adhesive layer. This composite polarizing plate 11 is combined with an image display element such as the liquid crystal cell 30 to form an image display apparatus.

Description

Technical Field [0001] The present invention relates to a composite polarizing plate, a laminated optical member, and an image display apparatus using the same,

The present invention relates to a composite polarizer comprising a polarizer, a retarder and a pressure-sensitive adhesive layer. The present invention also relates to a laminated optical member in which the composite polarizing plate is laminated on another optical layer and an image display apparatus in which the composite polarizing plate or laminated optical member is combined with an image display element such as a liquid crystal cell.

Background Art [0002] Liquid crystal display devices have heretofore been used in desk calculators, electronic timepieces, and the like, but their applications are rapidly expanding in recent years. That is, a liquid crystal display device is used regardless of the screen size from a mobile device such as a cellular phone to a large-sized TV. In addition, an organic electroluminescent (organic EL) display device in addition to a liquid crystal display device tends to increase mainly in mobile applications. The demand for polarizers used in these image display devices is increasing, and performance suitable for each application is required.

The polarizing plate widely used in such an image display apparatus generally has a structure in which a transparent protective layer typified by a triacetylcellulose film is laminated on both sides of a polarizer in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol- . In this state, or in accordance with necessity, various optical layers such as a retardation plate or an optical compensation plate exhibiting predetermined optical characteristics are bonded through an adhesive or a pressure-sensitive adhesive, and an image such as a liquid crystal cell or an organic EL element And is used by being attached to the display element.

FIG. 9 is a schematic view showing a typical example of such a conventional polarizing plate and a composite polarizing plate in which a retardation plate is laminated thereon. That is, the transparent protective layers 2 and 3 are provided on both sides of the polarizer 1 to constitute the polarizing plate 40. [ The retardation plate 5 is bonded to the transparent protective layer 3 side via the pressure sensitive adhesive layer 6 and the pressure sensitive adhesive layer 7 for bonding to image display elements or the like is provided on the outer side thereof A complex polarizing plate 41 is constituted. A release film 9 is usually provided on the outer side of the pressure-sensitive adhesive layer 7 to protect the surface of the pressure-sensitive adhesive layer 7 until it is adhered to an image display device or the like.

2. Description of the Related Art In recent years, in an image display device for mobile use such as a mobile phone, slimming down the entire module in terms of design and portability has been progressed. It is a matter of course that further reduction in thickness and weight of polarizing plates used therefor is desired. In addition, due to the mobile use, various places are used, so that it is required to have a thin and lightweight structure and a durability higher than that of the prior art. In addition, a composite polarizing plate of a thin configuration is desired which is less likely to cause blurring or unclearness of the display image, while ensuring the brightness when viewed from the front and from the oblique view.

Therefore, instead of providing the transparent protective layers 2 and 3 on both sides of the polarizer 1 as shown in Fig. 9, the transparent protective layer 3 ) Is omitted and other optical films such as the retardation plate 5 are directly laminated to the polarizer 1 through an adhesive or a pressure-sensitive adhesive to reduce the thickness of the polarizer. However, in this case, there is a problem that it is difficult to obtain sufficient durability because the dimensional change accompanied by elongation and contraction of the polarizer 1 becomes large especially when it is placed under a high temperature environment or when a high temperature environment and a low temperature environment are repeated.

On the other hand, it has also been proposed to replace the triacetylcellulose film as the transparent protective layer with another resin. For example, Japanese Patent Application Laid-Open No. 2000-199819 (Patent Document 1) discloses a method of coating a resin solution by a solvent which does not dissolve the film on one side or both sides of a polarizer made of a hydrophilic polymer, And a protective layer made of a transparent film is disposed on the transparent thin film layer. Japanese Patent Application Laid-Open No. 2000-321430 (Patent Document 2) discloses a polarizing plate in which a protective film made of a cyclic olefin resin is laminated on at least one side of a polyvinyl alcohol polarizer through an adhesive composed of a mixture of a polyvinyl alcohol adhesive and a two- . Japanese Patent Application Laid-Open No. 2001-305345 (Patent Document 3) discloses a polarizing plate in which a protective film made of a norbornene resin is laminated on at least one surface of a polarizer made of a polyvinyl alcohol-based sheet through an aqueous polymer-isocyanate adhesive. .

When the transparent film or the cycloolefin based resin film disclosed in Patent Documents 1 to 3 (the synonymous of the norbornene resin film is almost synonymous) is configured to have the function of the retardation plate, the member to be adhered to the image display element is reduced A thin polarizing plate can be used. However, when an adhesive is used for the lamination of the polarizer and the transparent polymer film, since the adhesive is applied to the polarizer and the polymer film is laminated and cured, it is difficult to laminate the optical axis of the film so as to have a certain angle with respect to the axis of the polarizer There has been a problem in forming an elliptic or circular polarization mode composite polarizing plate useful for an image display device for mobile use. In addition, in the image display apparatus to which the polarizer and the transparent polymer film are bonded through the transparent adhesive, the shadow of the backlight and the image display element are uneven in the transmission type, and in the transflective type, There is a possibility that blurring or unclearness may occur on the display due to occurrence of interference phenomenon, which has limitations in increasing the visibility.

It is also known to use a pressure-sensitive adhesive (pressure-sensitive adhesive) to adhere a norbornene resin film to a polarizer as described above. For example, Japanese Unexamined Patent Application Publication No. 6-51117 (Patent Document 4) discloses a polarizing plate in which a thermoplastic saturated norbornene resin film is laminated on at least one surface of a polarizer as a protective layer. JP-A-8-43812 (Patent Document 5) discloses a polarizing plate in which a protective film is laminated on both sides of a polarizer, and at least one of the protective films has a function of a retardation plate at the same time, An example of a protective film having a plate function is a thermoplastic norbornene resin. In these Patent Documents 4 and 5, as a pressure-sensitive adhesive (pressure-sensitive adhesive) used for lamination of a polarizer and a norbornene resin film, natural rubber, synthetic rubber / elastomer, vinyl chloride / vinyl acetate copolymer, polyvinyl alkyl ether, polyacrylate, Polyolefin-based resin-based pressure-sensitive adhesives, and the like.

It is conceivable to provide a light-diffusing pressure-sensitive adhesive layer in which a light-diffusing agent is blended with the pressure-sensitive adhesive in order to improve the visibility by eliminating the blur and lack of sharpness on the display. However, in the case of a light-diffusing pressure-sensitive adhesive layer formed by mixing a light-diffusing agent with a general pressure-sensitive adhesive, there is a case where the durability is caused by the lack of cohesive force of the pressure-

Therefore, in polarizing plates for mobile applications, which are required to be thin and lightweight due to the reduction of constituent members, there is a demand for a polarizing plate that maintains thin and good durability and also has good visibility. On the other hand, development of a thin polarizing plate using a pressure-sensitive adhesive having a high degree of manufacturing freedom has also been demanded in a lamination process with a polymer film having optical properties or another optical layer.

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-199819

Patent Document 2: Japanese Patent Application Laid-Open No. 2000-321430

Patent Document 3: Japanese Patent Application Laid-Open No. 2001-305345

Patent Document 4: Japanese Patent Application Laid-Open No. 6-51117

Patent Document 5: JP-A-8-43812

An object of the present invention is to provide a composite polarizing plate in which a transparent protective layer is disposed on one side of a polarizer and a retardation plate is laminated on the other side through a pressure sensitive adhesive layer to reduce the thickness and weight of the polarizing plate, At least one of the pressure-sensitive adhesive layers existing between the pressure-sensitive adhesive layer for bonding the pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer provided on the outer side of the phase difference plate (including the pressure-sensitive adhesive layer) It is possible to secure the brightness when the display device is viewed from the front and from the oblique view to make it less likely to cause blurring or unclearness on the display and further improve the pressure sensitive adhesive layer containing such a light diffusion agent, When it is placed under the high temperature environment and when the low temperature environment is repeated, And a composite polarizing plate of a thin configuration capable of exhibiting a composition.

It is still another object of the present invention to provide a laminated optical member excellent in durability and visibility by combining such a composite polarizing plate with an optical layer exhibiting another optical function. Still another object of the present invention is to provide an image display apparatus by combining such a composite polarizing plate or a laminated optical member with an image display element such as a liquid crystal cell.

In order to achieve the above-mentioned object, the composite polarizing plate of the present invention is characterized in that a transparent protective layer is disposed on one side of a polarizer made of a polyvinyl alcohol-based resin film, and at least one retardation is provided on the other side of the polarizer through a first pressure- Sensitive adhesive layer that is present between the first and second pressure-sensitive adhesive layers and the second pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer being disposed on the outer side of the retarder located farthest from the polarizer, At least one of the layers is a light-diffusing pressure-sensitive adhesive layer containing a light-diffusing agent and exhibiting a storage elastic modulus of 0.15 to 10 MPa at 23 DEG C, preferably a storage elastic modulus of 0.15 to 10 MPa at 23 DEG C and 80 DEG C. And a light-diffusing pressure-sensitive adhesive layer.

Thus, the retarder is laminated on one side of the polarizer through the first pressure-sensitive adhesive layer, whereby the composite polarizer is made thin and lightweight by reducing the number of members. When at least one of the pressure-sensitive adhesive layers existing between the two layers including the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is composed of a compounded light diffusing agent and the image display device to which the compound polarizer is applied is viewed from the front And the brightness when viewed from the oblique direction is ensured, making it less likely to cause blurring or unclearness on the display, thereby enhancing the visibility. The pressure-sensitive adhesive layer containing the light-diffusing agent is composed of a light-diffusing pressure-sensitive adhesive layer exhibiting a relatively high storage elastic modulus at 23 ° C of 0.15 to 10 MPa, preferably at 23 ° C and 80 ° C, of 0.15 to 10 MPa The problem of durability due to lack of cohesion of the pressure-sensitive adhesive layer is suppressed when the pressure-sensitive adhesive layer is placed under a high-temperature environment or when a high-temperature environment and a low-temperature environment are repeated.

At least two of the pressure-sensitive adhesive layers present in the composite polarizing plate include at least one layer thereof containing a light-diffusing agent. The pressure-sensitive adhesive layer preferably has a thickness of 0.15 to 10 MPa at 23 캜, preferably 0.15 to 10 MPa at 23 캜 and 80 캜 And a light diffusing pressure-sensitive adhesive layer showing a storage modulus of elasticity. Normally, one layer satisfies this condition. The haze value of the light-diffusing pressure-sensitive adhesive layer is 5% or more. When the haze value is 5% or more, the visibility is good. Further, from the viewpoints of durability and adhesive property, it is preferably 90% or less. From the above points, the haze value is preferably in the range of 20 to 90%, particularly preferably 30 to 75%. The thickness of the light-diffusing pressure-sensitive adhesive layer is preferably in the range of 1 to 40 탆. If the thickness is less than 1 占 퐉, the pressure-sensitive adhesive properties and durability may be insufficient. If the thickness exceeds 40 占 퐉, problems such as residual solvent may occur. From such a viewpoint, the thickness of the light-diffusing pressure-sensitive adhesive layer is preferably 3 to 25 mu m. The first pressure-sensitive adhesive layer for bonding the polarizer and the retarder to each other preferably has a storage elastic modulus of 0.15 to 10 MPa at 23 DEG C, preferably 0.15 to 10 MPa at 23 DEG C and 80 DEG C, Is preferably taken. When the storage elastic modulus at 23 캜 is 0.15 MPa or more, excellent dimensional stability under a high temperature environment can be obtained even in the composite polarizing plate of the present invention having only a transparent protective layer on one side of the polarizer, and the storage elastic modulus at 23 캜 If it is 10 MPa or less, sufficient adhesion between the polarizer and the retarder can be exhibited.

In the above composite polarizing plate, when the retarder has one sheet, either the first pressure-sensitive adhesive layer existing between the polarizer and the retarder and the second pressure-sensitive adhesive layer disposed outside the retarder contain the light-diffusing agent, and 23 Sensitive adhesive layer exhibiting a storage elastic modulus of 0.15 to 10 MPa at 0.1 to 10 MPa, preferably 23 to 80 MPa, preferably at 23 and 80 DEG C. In either case, the first pressure-sensitive adhesive layer And the pressure-sensitive adhesive layer is preferably a light-diffusing pressure-sensitive adhesive layer exhibiting a storage elastic modulus at 23 ° C of 0.15 to 10 MPa, preferably at 23 ° C and 80 ° C of 0.15 to 10 MPa Do.

On the other hand, in the above composite polarizing plate, when two retardation plates are used, it is preferable that these two retardation plates are laminated through the third pressure sensitive adhesive layer. In this case, the first pressure-sensitive adhesive layer existing between the polarizer and the retarder, the second pressure-sensitive adhesive layer disposed on the outer side of the retarder located farther from the polarizer, and the third pressure- Any one of them may be a light-diffusing pressure-sensitive adhesive layer containing a light-diffusing agent and exhibiting a storage elastic modulus at 23 ° C of 0.15 to 10 MPa, preferably at 23 ° C and 80 ° C, of 0.15 to 10 MPa. Sensitive adhesive layer for bonding the retarder to the retarder, or the third pressure-sensitive adhesive layer for bonding the two retarders to each other, and the pressure-sensitive adhesive layer has a pressure-sensitive adhesive layer of 0.15 to 10 MPa, It is preferable to exhibit a storage modulus of 0.15 to 10 MPa at 23 占 폚 and 80 占 폚.

In such a composite polarizing plate, the second pressure-sensitive adhesive layer disposed on the outer side of the retarder located farthest from the polarizer is treated with a releasing agent such as a silicone material on the exposed surface in view of convenience in handling until the object adheres to the adherend It is preferable that a release film is present.

The laminated optical member of the present invention is composed of a laminate of any one of the above specific composite polarizing plates and an optical layer exhibiting different optical functions. Examples of the optical layer exhibiting other optical functions include a surface treatment layer such as a hard coat layer, an antireflection layer, and an antiglare layer, and a reflective layer, a transflective layer, and a luminance enhancement film.

For example, in the above composite polarizing plate, a surface treatment layer such as a hard coat layer, an antireflection layer, and an antiglare layer may be provided on the opposite side of the surface of the transparent protective layer disposed on one side of the polarizer in contact with the polarizer. In the composite polarizing plate described above, a reflective layer or a transflective layer may be formed on the opposite side of the surface of the transparent protective layer disposed on one side of the polarizer in contact with the polarizer to form a reflective polarizer or a transflective polarizer. Further, in the above-mentioned composite polarizing plate, a composite polarizing plate capable of reusing light from a light source by bonding a brightness enhancement film to the opposite side of the transparent protective layer disposed on one side of the polarizer with an adhesive or a pressure- You may.

The image display apparatus of the present invention includes the composite polarizing plate or the laminated optical member and the image display element such as the liquid crystal cell or the organic EL element. The above-mentioned composite polarizing plate or laminated optical member is disposed on at least one side of the image display device. Normally, the composite polarizing plate or the laminated optical member is bonded to the image display element through the second pressure-sensitive adhesive layer disposed outside the retarder located farthest from the polarizer in the composite polarizing plate or laminated optical member.

In the composite polarizing plate of the present invention, since the retarder is laminated on one side of the polarizer through the first pressure-sensitive adhesive layer, the number of members is reduced and the thickness is reduced. It is preferable that at least one of the pressure-sensitive adhesive layers existing between the first pressure-sensitive adhesive layer and the polarizer includes a second pressure-sensitive adhesive layer disposed on the outer side of the retarder, And the pressure-sensitive adhesive layer containing the light-diffusing agent is composed of a light-diffusing pressure-sensitive adhesive layer exhibiting a predetermined storage modulus at 23 占 폚, preferably 23 占 폚 and 80 占 폚, so that it has high durability and excellent visibility .

Further, the laminated optical member of the present invention is obtained by laminating an optical layer exhibiting another optical function on the above-mentioned composite polarizing plate, and is also a thin and lightweight structure, and has excellent durability and visibility. Such a composite polarizing plate or laminated optical member provides an image display device which is thin in thickness and excellent in durability and visibility.

1 is a schematic cross-sectional view showing an example of the layer structure of the composite polarizing plate of the present invention.
2 is a schematic cross-sectional view showing another example of the layer structure of the composite polarizing plate of the present invention.
3 is a schematic cross-sectional view showing an example of application of the composite polarizing plate and the laminated optical member of the present invention to a liquid crystal display device.
4 is a schematic cross-sectional view showing the layer structure of the composite polarizing plate produced in Example 1 and Comparative Example 1. Fig.
5 is a schematic cross-sectional view showing the layer constitution of the composite polarizing plate produced in Example 2 and Comparative Example 2. Fig.
6 is a schematic cross-sectional view showing the layer structure of the composite polarizing plate produced in Example 3 and Comparative Example 3. Fig.
7 is a schematic cross-sectional view showing the layer constitution of the composite polarizing plate produced in Example 4-11 and Comparative Example 4-5.
8 (A) is an enlarged photograph of the composite polarizing plate obtained in Example 2, and (B) is an enlarged image of a sample after heat shock test for the composite polarizing plate obtained in Comparative Example 2, as viewed from the transparent protective layer side of the polarizer.
Fig. 9 is a schematic cross-sectional view showing an example of the layer structure of a conventional composite polarizing plate.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings as appropriate.

[Composite Polarizer]

1 is a schematic cross-sectional view showing an example of the layer structure of the composite polarizing plate of the present invention. In the present invention, as shown in the figure, a transparent protective layer 2 is disposed on one surface of the polarizer 1, and a retarder (not shown) is disposed on the other surface of the polarizer 1 through a first pressure- 5 is laminated on the outer side of the retarder 5 and the second pressure-sensitive adhesive layer 7 is disposed on the outer side of the retarder 5 to form the composite polarizer 11. The release film 9 is usually provided on the outer side of the second pressure-sensitive adhesive layer 7 located on the outer side of the retarder 5 to adhere and protect the surface of the pressure-sensitive adhesive layer 7 until it is adhered to an image display device. Although the retardation plate 5 can be composed of a plurality of plates, the second pressure sensitive adhesive layer 7 is disposed outside the retardation plate located farthest from the polarizer 1 in this case.

The first pressure sensitive adhesive layer 6 joining the polarizer 1 and the retardation plate 5 and the second pressure sensitive adhesive layer 7 located outside the retardation plate 5, At least one layer of the adhesive layer is composed of a light-diffusing pressure-sensitive adhesive layer containing a light-diffusing agent and exhibiting a storage elastic modulus of 0.15 to 10 MPa at 23 DEG C and 0.15 to 10 MPa, preferably 23 DEG C and 80 DEG C. Since the storage elastic modulus generally decreases (gradually decreases) with increasing temperature, if the storage elastic modulus at 23 deg. C and 80 deg. C falls within the above range, the storage elastic modulus can be regarded as the storage elastic modulus at the temperature within this range.

1, when at least one of the first pressure-sensitive adhesive layer 6 and the second pressure-sensitive adhesive layer 7 contains a light-diffusing agent as described above, Sensitive adhesive layer exhibiting a storage elastic modulus at 0.15 to 10 MPa, preferably at 23 ° C and 80 ° C, of 0.15 to 10 MPa. In this case, from the viewpoint of obtaining a composite polarizing plate having the best visibility by increasing the light diffusion efficiency most, a light diffusing agent is applied to the first pressure-sensitive adhesive layer 6 disposed on the side of the polarizer 1 opposite to the side in contact with the transparent protective layer 2 , And the pressure-sensitive adhesive layer (6) is preferably a light-diffusing pressure-sensitive adhesive layer exhibiting a storage elastic modulus at 23 ° C of 0.15 to 10 MPa, preferably at 23 ° C and 80 ° C, of 0.15 to 10 MPa. In addition, from the viewpoint of obtaining a uniform brightness for a long time with no luminance unevenness in an image display apparatus, no foaming occurs in the adhesive layer even under a high-temperature environment, and the light-diffusing pressure- It is preferable that the average particle diameter is 0.1 to 20 탆, the storage elastic modulus at 23 캜 of the layer is 0.3 to 10 MPa and the haze value is 5% or more, and the storage elastic modulus at 23 캜 and 80 캜 is And particularly preferably 0.3 to 10 MPa. It is also preferable that the first pressure-sensitive adhesive layer 6 is made of the light-diffusing pressure-sensitive adhesive layer so that the second pressure-sensitive adhesive layer 7 provided through the retarder 5 can be freely designed. That is, since the liquid crystal cell is expensive, there is a desire to reuse the liquid crystal cell by peeling when the composite polarizing plate is damaged. In this case, if the first pressure-sensitive adhesive layer 6 is a composite polarizing plate having a light-diffusing pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer 7 can be a releasable pressure-sensitive adhesive layer, Peelability can be achieved at the same time. In addition, since a thin type image display apparatus is desired, there is a case where the glass surface of the liquid crystal cell is ground to reduce the thickness, but in this case, the glass surface becomes roughened. The second pressure-sensitive adhesive layer 7 is prevented from being blurred or unclear due to the light-diffusing pressure-sensitive adhesive layer of the first pressure-sensitive adhesive layer 6 when the pressure-sensitive adhesive layer 7 is adhered to such a roughened glass surface Pressure sensitive adhesive layer having high followability capable of embedding the pressure-sensitive adhesive layer (i.e., the roughened surface). On the other hand, from the viewpoint of durability, the light-diffusing agent is contained in the second pressure-sensitive adhesive layer 7 disposed on the side of the retardation plate 5 and adhered to the image display element or the like, Sensitive adhesive layer exhibiting a storage elastic modulus at 0.15 to 10 MPa, preferably at 23 DEG C and 80 DEG C, of 0.15 to 10 MPa. In addition, the composite polarizing plate having the light-diffusing pressure-sensitive adhesive layer exhibits good durability in the case of bonding, so that no foaming occurs in the adhesive layer even under a high-temperature environment. In the image display apparatus, From the viewpoint of obtaining brightness for a long time, the light-diffusing pressure-sensitive adhesive layer is formed such that the average particle diameter of the light-diffusing agent in this layer is 0.1 to 20 μm, the storage elastic modulus at 23 ° C. is 0.3 to 10 MPa, Value is preferably 5% or more, and it is particularly preferable that the storage elastic modulus at 23 占 폚 and 80 占 폚 is 0.3 to 10 MPa.

2 is a schematic cross-sectional view showing another example of the layer structure of the composite polarizing plate of the present invention. In the example shown in this drawing, the first retardation plate 4 and the second retardation plate 5 are used, and both of the retardation plates are laminated via the third pressure-sensitive adhesive layer 8. That is, in this example, the transparent protective layer 2 is disposed on one surface of the polarizer 1, and the first retarder 4 is laminated on the other surface of the polarizer 1 via the first pressure sensitive adhesive layer 6 And the third pressure sensitive adhesive layer 8 and the second retardation plate 5 are sequentially laminated on the outer side and the second pressure sensitive adhesive layer 7 is disposed on the outer side of the second retardation plate 5 , And a composite polarizing plate (12). Even when three or more phase difference plates are laminated, it is preferable that the respective retardation plates are laminated through the pressure sensitive adhesive layer. The outer side of the second pressure sensitive adhesive layer 7 located outside the second retardation plate 5 is provided with a release film 9 for adhering and protecting the surface thereof until it is usually adhered to an image display element or the like. It is the same as the example shown.

2, the first pressure sensitive adhesive layer 6 for bonding the polarizer 1 and the first retardation plate 4, the second pressure sensitive adhesive layer 7 located outside the second retardation plate 5, , And the third pressure-sensitive adhesive layer (8) for bonding the first retardation plate (4) and the second retardation plate (5) contain a light-diffusing agent and have a thickness of 0.15 to 10 MPa Sensitive adhesive layer exhibiting a storage modulus of 0.15 to 10 MPa at 23 占 폚 and 80 占 폚. In this case, the transparent protective layer 2, the polarizer 1, the first pressure-sensitive adhesive layer 6, the retarder 4, the third pressure-sensitive adhesive layer 6, and the third pressure- In the composite polarizing plate of the present invention, which is laminated with the adhesive layer 8, the retarder 5, the second pressure-sensitive adhesive layer 7 and the release film 9, the first pressure-sensitive adhesive layer 6, The pressure-sensitive adhesive layer contains a light-diffusing agent in any one of the adhesive layers (8), and the pressure-sensitive adhesive layer has a light diffusing property which exhibits a storage elastic modulus at 23 ° C of 0.15 to 10 MPa, preferably at 23 ° C and 80 ° C, Pressure-sensitive adhesive layer. In addition, from the viewpoint of obtaining a uniform brightness without a brightness unevenness for a long period of time in the case of using an image display apparatus, the light-diffusing pressure-sensitive adhesive layer has an average particle diameter The storage elastic modulus at 23 占 폚 is preferably 0.3 to 10 MPa and the haze value is preferably 5% or more, and the storage elastic modulus at 23 占 폚 and 80 占 폚 is preferably 0.3 to 20 占 퐉, 10 MPa is particularly preferable. The use of any one of the first pressure-sensitive adhesive layer (6) or the third pressure-sensitive adhesive layer (8) as the light-diffusing pressure-sensitive adhesive layer can freely design the second pressure-sensitive adhesive layer (7) It is also preferable from the viewpoint of being able to. That is, since the liquid crystal cell is expensive, there is a desire to reuse the liquid crystal cell by peeling when the composite polarizing plate is damaged. In this case, if any of the first pressure sensitive adhesive layer (6) or the third pressure sensitive adhesive layer (8) is a light diffusing pressure sensitive adhesive layer, the second pressure sensitive adhesive layer (7) It is possible to make both the visibility and re-peelability of the composite polarizing plate. In addition, thin-film image display apparatuses are demanded to grind the glass surface of the liquid crystal cell to achieve thinness. In this case, however, the glass surface is roughened. Sensitive adhesive layer (6) or the third pressure-sensitive adhesive layer (8) is prevented from being blurred or unclear due to the light-diffusing pressure-sensitive adhesive layer of the first pressure-sensitive adhesive layer (6) Pressure sensitive adhesive layer having high followability capable of embedding the roughened surface of the pressure-sensitive adhesive layer (7). On the other hand, from the viewpoint of durability, the second pressure-sensitive adhesive layer 7 disposed on the outer side of the retarder 5 located farther from the polarizer 1 or the third pressure-sensitive adhesive layer 8 is preferably a light-diffusing pressure-sensitive adhesive layer containing a light-diffusing agent and exhibiting a storage elastic modulus of 0.15 to 10 MPa at 23 ° C at 0.15 to 10 MPa, preferably 23 ° C and 80 ° C . In addition, the composite polarizing plate having the light-diffusing pressure-sensitive adhesive layer exhibits good durability in the case of bonding, so that no foaming occurs in the adhesive layer even under a high-temperature environment. In the image display device, From the viewpoint of obtaining brightness for a long time, the light-diffusing pressure-sensitive adhesive layer preferably has an average particle diameter of the light-diffusing agent in this layer of 0.1 to 20 탆, a storage elastic modulus at 23 캜 of 0.3 to 10 MPa, a haze value of 5% , And it is particularly preferable to set the storage elastic modulus at 23 占 폚 and 80 占 폚 to 0.3 to 10 MPa.

As described above, in the present invention, the first pressure-sensitive adhesive layer 6 disposed on one side of the polarizer 1 for bonding with the retarder 5 or 4, and the retarder plate located farthest from the polarizer 1 Sensitive adhesive layer (7) disposed on the outside of the pressure-sensitive adhesive layer (5), and at least one of the pressure-sensitive adhesive layers existing between the two retardation plates contains a light-diffusing agent. By disposing the pressure-sensitive adhesive containing the light-diffusing agent, the brightness when the image display apparatus to which the composite polarizing plate is applied is viewed from the front and from the oblique direction is ensured, and blurring or unclearness on the display becomes less likely to occur. The pressure-sensitive adhesive layer containing the light-diffusing agent is composed of a light-diffusing pressure-sensitive adhesive layer exhibiting a relatively high storage elastic modulus of 0.15 to 10 MPa at 23 ° C and 0.15 to 10 MPa, preferably 23 ° C and 80 ° C have. This makes it possible to enhance the durability of the composite polarizing plate or the image display device using the same when exposed to a high temperature environment or repeatedly in a high temperature environment and a low temperature environment. In addition, the composite polarizing plate having the light-diffusing pressure-sensitive adhesive layer exhibits good durability in the case of bonding, does not cause foaming from occurring in the adhesive layer even under a high-temperature environment, From the viewpoint that there is no luminance unevenness and uniform brightness can be obtained for a long time, the light-diffusing pressure-sensitive adhesive layer has a light diffusing agent in this layer having an average particle diameter of 0.1 to 20 μm and a storage elastic modulus at 23 ° C. of 0.3 To 10 MPa, and the haze value of this layer is preferably 5% or more, more preferably 0.3 to 10 MPa at 23 占 폚 and 80 占 폚.

In the present invention, as shown in Figs. 1 and 2, the first pressure-sensitive adhesive layer 6 is directly disposed on one surface of the polarizer 1, and the retarder 5 or 4 is bonded thereto. Therefore, compared with the conventional polarizing plate in which the transparent protective layer is adhered to both surfaces of the polarizer, the force to suppress the expansion and contraction of the polarizer 1 when exposed to a high temperature environment is small. Therefore, the first pressure-sensitive adhesive layer 6, which bonds the polarizer 1 and the retarder 5 or 4, has a storage elastic modulus at 23 占 폚 of 0.15 to 10 MPa, preferably 23 Deg.] C and 80 [deg.] C, respectively. When the pressure-sensitive adhesive layer (6) is a light-diffusing pressure-sensitive adhesive layer, the light diffusing agent of this layer has an average particle diameter of 0.1 to 20 μm, a storage elastic modulus at 23 ° C. of 0.3 to 10 MPa, The haze value of this layer is preferably 5% or more, and the storage elastic modulus at 23 캜 and 80 캜 is particularly preferably 0.3 to 10 MPa. As described above, when the first pressure-sensitive adhesive layer 6 for bonding the polarizer 1 and the retarder 5 or 4 is made to have a high storage elastic modulus, when the composite polarizer or the image display device using the same is exposed to high temperatures It is possible to suppress the dimensional change accompanying the elongation and contraction of the polarizer 1 when the high-temperature environment and the low-temperature environment are repeated.

Hereinafter, each member constituting the composite polarizing plate of the present invention will be described.

[Polarizer]

The polarizer 1 is a film having a function of extracting linearly polarized light from incident natural light. Specifically, a polarizing film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film can be used. The polyvinyl alcohol-based resin constituting the polarizer (1) can be obtained by saponifying a polyvinyl acetate-based resin. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and other monomers copolymerizable therewith, and the like. Other monomers copolymerized with vinyl acetate include, for example, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group. The degree of saponification of the polyvinyl alcohol-based resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be further modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

A film of such a polyvinyl alcohol-based resin is used as a raw film of the polarizer 1. The method of forming the polyvinyl alcohol-based resin is not particularly limited and the film formation can be carried out by a known method. The thickness of the original film made of a polyvinyl alcohol-based resin is not particularly limited, but is, for example, about 1 to 150 mu m. Considering ease of stretching, etc., the film thickness is preferably 10 占 퐉 or more.

The polarizer 1 is a step of uniaxially stretching the polyvinyl alcohol-based resin film, a step of staining the polyvinyl alcohol-based resin film with a dichroic dye to adsorb the dichroic dye, a step of dying the polyvinyl alcohol- A step of treating the alcoholic resin film with an aqueous solution of boric acid, and a step of washing the aqueous solution with the aqueous solution of boric acid. As the dichromatic dye, iodine or a dichroic organic dye is used.

[Transparent protective layer]

On one surface of the polarizer 1, a transparent protective layer 2 is disposed. A suitable resin film may be used for the transparent protective layer 2. Specifically, a film made of a resin excellent in transparency, uniform optical characteristics, mechanical strength, thermal stability, etc. is preferably used. For example, cellulose-based resin films such as triacetylcellulose and diacetylcellulose, polyester-based resin films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate, polyester resins such as poly [methyl (meth) acrylate] (Meth) acrylate], a polycarbonate resin film, a polyether sulfone resin film, a polysulfone resin film, a polyimide resin film, a polyolefin resin film, a norbornene, And cyclic olefin based resin films made of monomers. An adhesive or a pressure-sensitive adhesive may be used for the adhesion between the polarizer 1 and the transparent protective layer 2.

A surface treatment layer such as a hard coat layer, an antireflection layer and an antiglare layer (antiglare layer) may be provided on the surface of the transparent protective layer 2 as necessary. The hard coat layer is formed for the purpose of preventing the surface of the polarizing plate from being damaged. The hard coat layer is appropriately selected from a resin such as an ultraviolet ray hardening type resin, for example, acrylic or silicone resin having excellent adhesion and hardness to the transparent protective layer 2, 2 can be formed. The antireflection layer is formed for the purpose of preventing reflection of external light on the surface of the polarizing plate and can be formed by a known method. In addition, the antiglare layer is formed in order to prevent the visibility of external light from being reflected on the surface of the polarizing plate. For example, the antiglare layer may be formed by a roughening method such as a sand blast method or an embossing method, It is generally formed to have a concavo-convex structure on the surface of the transparent protective layer 4 by a method of coating and curing the liquid.

[Retardation plate]

A first pressure sensitive adhesive layer 6 is provided on the other surface of the polarizer 1 and at least one retardation plate 5 and / or 4 is attached thereto. The retardation plates 4 and 5 may be first made of various transparent resin films as exemplified as the resin constituting the transparent protective layer 2, and in particular, the retardation films 4 and 5 may have properties required as retardation plates, Is preferably selected to be used for the purpose of protecting the polarizer 1 and compensating the phase difference due to the liquid crystal cell (including the meaning of the viewing angle compensation). As examples thereof, those conventionally used in an image display apparatus can be used without limitation, and a birefringent film made of stretched films of various transparent resins, a discotic liquid crystal, a film in which a nematic liquid crystal is aligned and fixed , And those in which such a liquid crystal layer is formed on a base film. When a liquid crystal layer is fixed on a base film, a cellulose resin film such as triacetyl cellulose is preferably used as a base film for supporting the aligned liquid crystal layer.

As the resin for forming the birefringent film, for example, a resin such as a polycarbonate-based resin, a polyvinyl alcohol-based resin, a polystyrene-based resin, a polymethylmethacrylate-based resin and a polypropylene- And cyclic polyolefins based on the same cyclic olefin as the monomer. The stretched film may be processed in a suitable manner such as a single-axis or a double-axis. It is also possible to use a birefringent film in which the refractive index in the thickness direction of the film is controlled by applying a shrinking force and / or a stretching force under adhering to the heat-shrinkable film.

As the retarder, a wavelength plate (lambda / 2 plate or lambda / 4 plate) capable of forming a compound polarizing plate of elliptically polarized light or circularly polarized light mode, which is used in an image display apparatus for mobile use, is effectively used. The elliptically polarized light or circularly polarized light composite polarizing plate has a function of converting elliptically polarized light or circularly polarized light when incident polarized light is linearly polarized light and changing it into linearly polarized light when incident polarized light is elliptically polarized light or circularly polarized light. A retardation plate capable of changing elliptically polarized light or circularly polarized light to linearly polarized light and linearly polarized light to elliptically polarized light or circularly polarized light and which is called a? / 4 plate which gives an in-plane retardation of 1/4 wavelength to a certain wavelength? Is used. The? / 2 plate which gives an in-plane retardation of 1/2 wavelength to a certain wavelength? Of visible light has a function of rotating the direction of linearly polarized light. As the? / 4 plate, for example, an in-plane retardation of about 90 to 160 nm can be used. As the? / 2 plate, for example, an in-plane retardation of about 200 to 300 nm can be used.

In addition, the above-described elliptically polarized composite polarizing plate is also effective in preventing a coloring phenomenon caused by birefringence of a liquid crystal in a liquid crystal display device, and the composite polarizing plate in a circularly polarized light mode is effective for a reflection type or transflective type image display For the purpose of improving the luminance in the display device. The composite polarizer in the circularly polarized mode also has an antireflection function.

As shown in Fig. 1, in the case of constituting one retardation plate, a preferable retardation plate 5 is? / 4 plate. In this case, the polarizer 1 and the lambda / 4 plate 5 are laminated so that the latter slow axis is about 45 DEG or about 135 DEG with respect to the polarized light transmission axis of the former, And functions as a circularly polarizing plate.

2, the first retardation plate 4 disposed on the side of the polarizer 1 as a combination of the retardation plates is a lambda / 2 plate, and the polarizer 1 And the second retardation plate 5 disposed on the far side is a? / 4 plate. In this case, for example, with respect to the polarized light transmission axis of the polarizer 1, the slow axis of the? / 2 plate 4 as the first retardation plate is about 15 占 and the retardation axis of the? / 4 plate 5 Or the slow axis of the? / 4 plate 5 as the second retardation plate is about 75 占 and the slow axis of the? / 2 plate 4 as the first retardation plate is about 75 deg. 195 degrees, the composite polarizing plate 12 functions as a circularly polarizing plate over a wide wavelength range.

[Pressure sensitive adhesive layer]

A first pressure-sensitive adhesive layer 6 for bonding the polarizer 1 and the retarder 5 or 4, a second pressure-sensitive adhesive layer 7 disposed on the outer side of the retarder 5 located farthest from the polarizer, , And the third pressure-sensitive adhesive layer 8 to be bonded to each other when two or more retardation plates are used may be composed of a pressure-sensitive adhesive material having a pressure-sensitive adhesive base polymer (also referred to as pressure-sensitive adhesive resin) The first layer is a light-diffusing pressure-sensitive adhesive layer formed of a viscous material containing a viscous resin and a light-diffusing agent. In addition, the pressure-sensitive adhesive layer may be a layer made of a pressure-sensitive adhesive material (hereinafter, sometimes referred to as a pressure-sensitive adhesive layer). Alternatively, by applying heat or an energy ray such as ultraviolet rays or electron rays to the pressure- Layer.

Specific examples of the adhesive base polymer (adhesive resin) include base polymers such as acrylic, rubber, urethane, silicone, and polyvinyl ether. It may also be an energy line curing type, a thermosetting type or the like. Of these, a tacky resin having an acrylic resin as a base polymer having excellent transparency, weather resistance and heat resistance is preferable. Specifically, the tacky resin is preferably composed of an acrylic copolymer (A) and an active energy ray curable compound (B) . (A) acrylic copolymers include (meth) acrylic acid ester copolymers. Here, (meth) acrylic acid means both acrylic acid and methacrylic acid, and other similar terms are also the same.

As the (meth) acrylic acid ester-based copolymer, those having crosslinking points capable of crosslinking according to various crosslinking methods are preferably used. The (meth) acrylic ester-based copolymer having such a crosslinking point is not particularly limited, and any of the (meth) acrylic ester-based copolymers conventionally used as the resin component of the pressure-sensitive adhesive may be appropriately selected and used.

Examples of the (meth) acrylate-based copolymer having such a crosslinking point include (meth) acrylic acid esters in which the alkyl moiety of the ester moiety has 1 to 20 carbon atoms, monomers having a crosslinkable functional group in the molecule and other monomers Are preferably used. Examples of the (meth) acrylic acid ester in which the alkyl moiety of the ester moiety has 1 to 20 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, (Meth) acrylate, dicyclohexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (Meth) acrylate, stearyl (meth) acrylate, and the like. These may be used alone or in combination of two or more.

On the other hand, the monomer having a crosslinkable functional group in the molecule preferably contains at least one of hydroxyl group, carboxyl group, amino group and amide group as a functional group, and specific examples thereof include 2-hydroxyethyl (meth) acrylate, (Meth) acrylic acid such as hydroxypropyl, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl Hydroxyalkyl esters; Acrylamides such as N-methyl (meth) acrylamide, N-methyl (meth) acrylamide and N-methylol (meth) acrylamide; (Meth) acrylic acid monoalkylamino esters such as monomethylaminoethyl (meth) acrylate, monoethylaminoethyl (meth) acrylate, monomethylaminopropyl (meth) acrylate and monoethylaminopropyl (meth) acrylate; And ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid. These monomers may be used alone or in combination of two or more.

In the adhesive resin, the copolymerization type of the (meth) acrylic acid ester-based copolymer used as the component (A) is not particularly limited and may be any of random, block and graft copolymers. As the molecular weight, a weight average molecular weight of 500,000 or more is usually used. If the weight-average molecular weight is 500,000 or more, adhesion with the adherend and adhesion durability are sufficient, so that lifting or peeling does not occur. In consideration of adhesion and adhesion durability, the weight average molecular weight is preferably from 600,000 to 2,000,000, and more preferably from 700,000 to 2,000,000. The weight average molecular weight is a polystyrene reduced value measured by a gel permeation chromatography (GPC) method.

In the (meth) acrylic ester-based copolymer, the content of the monomer unit having a crosslinkable functional group in the molecule is preferably in the range of 0.01 to 10% by weight. When the content is 0.01% by weight or more, crosslinking is sufficient by reaction with a crosslinking agent described later, and durability is improved. On the other hand, if it is 10% by weight or less, the degree of crosslinking is excessively high, so that the compatibility with the liquid crystal glass cell or the retarder is not deteriorated. In view of durability and compatibility with the liquid crystal glass cell or retardation plate, the content of the monomer unit having a crosslinkable functional group is more preferably 0.05 to 7.0% by weight, particularly preferably 0.2 to 6.0% by weight. In the present invention, the (meth) acrylic acid ester copolymer of the component (A) may be used singly or in combination of two or more.

As the active energy ray curable compound used as the component (B) in the adhesive resin, a polyfunctional (meth) acrylate-based monomer having a molecular weight of less than 1,000 is preferably used.

Examples of the polyfunctional (meth) acrylate monomer having a molecular weight of less than 1,000 include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di ) Acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid neopentylpentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) Caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide modified di (meth) acrylate, di (acryloxyethyl) isocyanurate, allylcyclohexyl di (meth) acrylate, dimethyloldicyclo (Meth) acrylate, ethylene oxide modified dihydroxy phthalic acid di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, neopentyl glycol modified trimethylene Propane di (meth) acrylate, adamantane di (meth) acrylate, 9,9-bis [4- (2-oxy-acrylic) phenyl] fluorene such as the bifunctional type; (Meth) acrylate, propylene oxide-modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri (meth) acrylate, propylene oxide-modified trimethylolpropane tri (meth) acrylate, dipentaerythritol tri ) Acrylate, and tris (acryloxyethyl) isocyanurate; Tetrafunctional types such as diglycerin tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate; Pentafunctional type such as propionic acid-modified dipentaerythritol penta (meth) acrylate; And hexafunctional types such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

In the present invention, these polyfunctional (meth) acrylate monomers may be used alone, or two or more of them may be used in combination. Among them, those containing a cyclic structure in the skeleton structure are preferred. The cyclic structure may be a carbon-cyclic structure, a heterocyclic structure, a monocyclic structure or a polycyclic structure. Examples of such polyfunctional (meth) acrylate monomers include those having an isocyanurate structure such as di (acryloxyethyl) isocyanurate and tris (acryloxyethyl) isocyanurate; Cyclopentane diacrylate, ethylene oxide-modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol-modified trimethylolpropane diacrylate, and adamantane diacrylate.

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

Examples of the polyester acrylate oligomer include a polyester oligomer obtained by esterifying a hydroxyl group of a polyester oligomer having a hydroxyl group at both ends with condensation of a polyhydric carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, or by alkylating an alkylene oxide with a polyvalent carboxylic acid And esterifying the terminal hydroxyl group of the oligomer obtained in addition with (meth) acrylic acid. The epoxy acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin to effect esterification. A carboxyl modified epoxy acrylate oligomer obtained by partially modifying the epoxy acrylate oligomer with a dibasic carboxylic acid anhydride may also be used. The urethane acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by the reaction of a polyether polyol or a polyester polyol with a polyisocyanate with (meth) acrylic acid, and the polyol acrylate oligomer is obtained by reacting a polyether polyol Of (meth) acrylic acid.

The weight average molecular weight of the acrylate oligomer is preferably 50,000 or less, more preferably 500 to 50,000, and still more preferably 3,000 to 40,000 in terms of standard polystyrene measured by the GPC method. These acrylate oligomers may be used singly or in combination of two or more.

In the present invention, as the component (B), an adduct acrylate-based polymer having a group having a (meth) acryloyl group introduced into the side chain may be used. Such an adduct acrylate-based polymer is obtained by using a copolymer of the (meth) acrylic acid ester described in the above-mentioned (meth) acrylic ester-based copolymer of component (A) and a monomer having a crosslinkable functional group in the molecule, (Meth) acryloyl group and a compound having a group capable of reacting with a crosslinkable functional group on a part of the crosslinkable functional group of the crosslinkable functional group. The weight average molecular weight of the adduct acrylate polymer is usually 500,000 to 2,000,000 in terms of polystyrene.

In the present invention, as the component (B), one type may be appropriately selected from the polyfunctional acrylate-based monomer, the acrylate-based oligomer and the adduct acrylate-based polymer, or two or more types may be selected and used in combination.

In the present invention, the content of the acrylic copolymer of the component (A) and the active energy ray-curable compound of the component (B) is preferably from 100: 1 to 100: 100 in terms of the weight ratio of the pressure- Preferably 100: 5 to 100: 50, and more preferably 100: 10 to 100: 40.

[Light diffusing agent]

The light diffusing agent contained in the light-diffusing pressure-sensitive adhesive layer may be a fine particle having a refractive index different from that of the pressure-sensitive adhesive resin constituting the pressure-sensitive adhesive layer, and fine particles made of an inorganic compound or fine particles made of an organic compound (polymer) can be used. The refractive index difference between the viscous resin and the light diffusing agent is usually 0.01 or more, and it is preferably 0.01 or more and 0.5 or less in consideration of the brightness and visibility in the image display device. Considering this, the following are preferable as fine particles composed of an inorganic compound or an organic compound used as a light diffusing agent since the refractive index of the adhesive resin is usually around 1.4.

Examples of the fine particles made of an inorganic compound include aluminum oxide (refractive index: 1.76), silicon oxide (refractive index: 1.45), and the like.

(Refractive index: 1.57), polymethyl methacrylate beads (refractive index: 1.49), methyl methacrylate / styrene copolymer resin beads (refractive index: 1.50 to 1.59), polycarbonate beads 1.55), polyethylene beads (refractive index 1.53), polystyrene beads (refractive index 1.6), polyvinyl chloride beads (refractive index 1.46), epoxy resin beads (refractive index 1.5-1.6) and silicone resin beads (refractive index 1.46).

When an acrylic copolymer is selected as the component (A) of the adhesive resin, epoxy resin beads, polymethyl methacrylate beads, and silicone resin beads are excellent in dispersibility in the acrylic copolymer and uniform and good light diffusibility can be obtained Therefore, it is preferable as a light diffusing agent. The light diffusing agent is preferably spherical or monodispersed with uniform light diffusion.

The average particle diameter of the light diffusing agent is in the range of 0.1 to 20 占 퐉. If the average particle diameter is less than 0.1 占 퐉, the effect of the present invention in which the light diffusibility in the case of using a light-diffusing pressure-sensitive adhesive layer is reduced and uniform brightness is obtained without application of an unevenness of brightness Can not. On the other hand, when the average particle diameter exceeds 20 mu m, the contrast of the image is adversely affected, and when the average particle diameter is larger than the image pitch of the display, flashing occurs. From this point of view, the average particle diameter of the light diffusing agent is preferably in the range of 0.5 to 10 mu m, more preferably in the range of 1 to 7 mu m. Here, the average particle diameter of the light diffusing agent is a value measured by a centrifugal sedimentation optical transmission method.

The compounding amount of the light diffusing agent is appropriately determined in consideration of the haze value required for the light diffusing pressure-sensitive adhesive layer in which it is blended and the brightness of the image display device to which the compound is applied. Generally speaking, Is preferably in the range of 1 to 40 wt%, more preferably in the range of 3 to 30 wt%. On the other hand, if the content of the fine particles is less than 40% by weight, the adhesive strength to the adherend may be lowered more than necessary if the content of the fine particles is less than 40% by weight There is no.

The pressure-sensitive adhesive material of the present invention may contain a crosslinking agent as the component (C), if necessary. The cross-linking agent is not particularly limited, and any of conventional cross-linking agents in the acrylic adhesive resin can be appropriately selected and used. Examples of such a crosslinking agent include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides and metal salts, Compounds are preferably used.

Examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenated diphenylmethane diisocyanate. Alicyclic polyisocyanate and the like, and adducts and the like which are reaction products of buret and isocyanurate compounds, and furthermore, low molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylol propane, .

In the present invention, these crosslinking agents may be used singly or in combination of two or more kinds. The amount to be used varies depending on the type of crosslinking agent, but is usually 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight of the acrylic copolymer of the component (A).

The adhesive material of the present invention may contain a silane coupling agent as the component (D), if necessary. By containing this silane coupling agent, adhesion between the pressure-sensitive adhesive layer and the glass cell is improved, for example, when the liquid-crystal glass cell or the like is attached. The silane coupling agent is preferably an organosilicon compound having at least one alkoxysilyl group in the molecule, which has good compatibility with the pressure-sensitive adhesive component and has optical transparency, for example, substantially transparent. The amount of the silane coupling agent to be added is preferably 0.001 to 10 parts by weight, more preferably 0.005 to 5 parts by weight, based on 100 parts by weight of the acrylic copolymer of the component (A).

Specific examples of the silane coupling agent include a polymerizable unsaturated group-containing silicon compound such as vinyltrimethoxysilane, vinyltriethoxysilane, and 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxy Silane, silicon compounds having an epoxy structure such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) Amino group-containing silicon compounds such as methoxysilane and N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and 3-chloropropyltrimethoxysilane. These may be used singly or in combination of two or more.

To the adhesive material of the present invention, various additives commonly used in acrylic adhesive resins such as a tackifier, an antioxidant, an ultraviolet absorber, a light stabilizer, a softening agent and the like may be added .

It is preferable that the light-diffusing pressure-sensitive adhesive layer of the present invention is formed by irradiating actinic energy rays to a sticky material containing the component (B) as a tacky resin. Crosslinking is carried out by using an active energy ray, so that the entire pressure-sensitive adhesive layer can be crosslinked in an instant and homogeneously without distortion, and is also preferable in obtaining the storage elastic modulus of the present invention.

Examples of the active energy ray include ultraviolet rays and electron rays. The ultraviolet ray is obtained from a high-pressure mercury lamp, an electrodeless lamp, a xenon lamp, etc., while the electron beam can be obtained by an electron beam accelerator or the like. Of these active energy rays, ultraviolet rays are particularly preferable. In the case of using an electron beam, a light-diffusing pressure-sensitive adhesive can be formed without adding a photopolymerization initiator.

The irradiation energy of the active energy ray for the adhesive material is suitably selected so as to obtain a pressure-sensitive adhesive having a storage elastic modulus and an adhesive force for alkali-free glass described later. In the case of ultraviolet rays, the light intensity is 50 to 1000 mW / Cm < 2 > for electron beams, and 10 to 1000 krad for electron beams.

The light diffusing pressure-sensitive adhesive layer containing the light diffusing agent preferably has a haze value of 5% or more from the viewpoint of securing the brightness of the image display apparatus to which the composite polarizing plate is applied and making it difficult to cause blurring or unclearness on the display, , More preferably in the range of 20 to 90%, and still more preferably in the range of 30 to 75%. The haze value is a value expressed by JIS K7105 (diffuse transmittance / total light transmittance) x 100 (%).

In the present invention, the light-diffusing pressure-sensitive adhesive layer preferably has a gel fraction of 60% or more. That is, when the amount of the low molecular weight component enough to be extracted with an organic solvent is small, the light diffusing pressure-sensitive adhesive layer having a gel fraction of 60% or more is less likely to be lifted or peeled off, adhered to the adherend, Is high. The gel fraction is also preferably 85% or more, more preferably 90 to 99.9%. In the present invention, an image display device manufactured by adhering a composite polarizing plate having such a light-diffusing pressure-sensitive adhesive layer to, for example, a liquid crystal glass cell is difficult to cause light leakage even in a high temperature and high humidity environment, It is also excellent in that the degree of uncertainty is considerably suppressed. The method of measuring the gel fraction will be described in detail later.

The light-diffusing pressure-sensitive adhesive layer used in the present invention preferably has an adhesive force of 0.2 N / 25 mm or more to alkali-free glass. When the adhesive force is 0.2 N / 25 mm or more, an optical functional film such as a polarizing plate can be bonded to, for example, a liquid crystal glass cell with sufficient adhesive force. A more preferable adhesive force is 1.0 to 50 N / 25 mm.

It is also preferable that the adhesive force to polycarbonate is 5 N / 25 mm or more. If the adhesive force is 5 N / 25 mm or more, for example, the polarizing plate can be bonded to the retarder with sufficient adhesive force. The method of measuring the adhesive force will be described in detail later.

The light-diffusing pressure-sensitive adhesive layer used in the present invention is desirably a displacement amount (amount) after maintaining the holding force at 80 캜 after 70000 seconds of not more than 200 탆. When the amount of misalignment is 200 m or less, it is possible to maintain a good bonding state for a long period of time when an optical functional film such as a polarizing plate is stuck to, for example, a liquid crystal glass cell. The amount of this misalignment is more preferably 100 mu m or less. A method of measuring the amount of misalignment (holding force) will be described in detail later.

The thickness of the light-diffusing pressure-sensitive adhesive layer in which the light diffusing agent is mixed is determined depending on the adhesive strength and the like, but is usually in the range of 1 to 40 mu m. In order to form a thin composite polarizer for the purpose of the present invention, it is preferable to apply thinly within a range that does not impair the properties such as workability and durability. Therefore, when the thickness of the light-diffusing pressure-sensitive adhesive layer is 3 to 25 占 퐉, good workability is maintained, high durability is exhibited, and the brightness when viewing the image display device from the front or from the oblique angle is maintained, It is preferable from the viewpoint of making it difficult to cause blurring and unclearness.

[Storage elastic modulus of light-diffusing pressure-sensitive adhesive layer]

In the present invention, the light-diffusing pressure-sensitive adhesive layer in which the light-diffusing agent is incorporated exhibits a storage modulus of 0.15 to 10 MPa at 23 ° C, preferably 0.15 to 10 MPa at 23 ° C and 80 ° C. More preferably, it exhibits a storage elastic modulus of 0.4 to 3 MPa at 23 占 폚 and 80 占 폚. The storage elastic modulus of the pressure-sensitive adhesive layer is a value measured in accordance with JIS K7244. The pressure-sensitive adhesive layer used in a conventional image display apparatus or optical film for use therein has a storage elastic modulus of about 0.1 MPa at 23 캜 and a storage elastic modulus of 0.15 to 10 MPa of the pressure- It becomes a high value. The use of a hard pressure-sensitive adhesive layer exhibiting such a high storage modulus can compensate for a lack of cohesion when the film is placed under a high-temperature environment or when a high-temperature environment and a low-temperature environment are repeated, and the dimensional change accompanying the contraction of the polarizer Can be suppressed to be small. That is, good durability can be obtained. When the storage elastic modulus at 23 캜 is 10 MPa or less, it is preferable in the present invention in view of adhesive strength.

In the present invention, the storage modulus of the light-diffusing pressure-sensitive adhesive layer containing the light diffusing agent is maintained as high as described above. However, in order to achieve such a high storage modulus, the adhesive resin serving as a base may be constituted to exhibit such a high storage modulus. The means for setting the storage elastic modulus of the light-diffusing pressure-sensitive adhesive layer to such a high value is not particularly limited. For example, a pressure-sensitive adhesive material comprising (A) an acrylic copolymer and (B) an active energy ray- Ray is irradiated to cure it is preferable because a high storage elastic modulus is exhibited.

The first pressure-sensitive adhesive layer 6 for bonding the polarizer 1 and the retarder 5 or 4 to the pressure-sensitive adhesive layer 6 is preferably 0.15 to 10 MPa, more preferably 23 ° C. and 80 ° C., but it is also possible to adopt a method as described above even in the case where such a high storage elastic modulus is achieved without a light diffusing agent.

[Formation of pressure-sensitive adhesive layer and production of composite polarizer plate]

The method for forming the pressure-sensitive adhesive layer or the light-diffusing pressure-sensitive adhesive layer on the surface of the polarizer 1 or on the surface of the retardation plate 5 or 4 is not particularly limited and, for example, an organic solvent such as toluene or ethyl acetate, A solution prepared by dissolving or dispersing a material in an amount of 10 to 40% by weight is directly applied on the surface of a polarizer or retarder to be formed with a pressure-sensitive adhesive layer, followed by drying, and then a resin film treated with a releasing agent such as silicone Or a method of forming a pressure-sensitive adhesive layer on the above-mentioned release film and then transferring the pressure-sensitive adhesive layer onto a polarizer or a retarder can be adopted. When the pressure-sensitive adhesive layer is formed on the surface of the polarizer or the retarder, the pressure-sensitive adhesive layer may be formed on the pressure-sensitive adhesive layer-forming surface of the polarizer or retarder and on the polarizer or retarder of the pressure- For example, a corona treatment may be carried out.

A transparent protective layer 2 is disposed on one surface of the polarizer 1 shown in Fig. 1 and a retarder 5 is laminated on the other surface of the polarizer 1 through the first pressure sensitive adhesive layer 6 And the second pressure sensitive adhesive layer 7 is disposed outside the retardation plate 5, the transparent protective layer 2 is bonded to one surface of the polarizer 1, and the other surface of the polarizer 1 A retardation plate with a pressure sensitive adhesive provided with a pressure sensitive adhesive provided with a first pressure sensitive adhesive layer 6 and a second pressure sensitive adhesive layer 7 provided on one side of the retardation plate 5 was prepared, 1 pressure-sensitive adhesive layer 6 and the retarder 5 overlap. In addition, for example, a retardation plate with a double-sided pressure-sensitive adhesive provided with a first pressure-sensitive adhesive layer 6 and a second pressure-sensitive adhesive layer 7 on both surfaces of a retardation plate 5 is prepared, It is also possible to laminate a polarizing plate in which the transparent protective layer 2 is adhered on one side so that the first pressure sensitive adhesive layer 6 and the polarizer 1 overlap.

A transparent protective layer 2 is disposed on one side of the polarizer 1 as shown in Fig. 2 and the other side of the polarizer 1 is covered with a first pressure sensitive adhesive layer 6, When the third pressure-sensitive adhesive layer 8, the second retarder 5 and the second pressure-sensitive adhesive layer 7 are laminated in order, the transparent protective layer 2 is bonded to one surface of the polarizer 1, A polarizing plate with a pressure sensitive adhesive provided with a first pressure sensitive adhesive layer 6 on the other surface of the polarizer 1 and a first pressure sensitive adhesive layer 6 provided with a pressure sensitive adhesive layer 8 on one surface of the first retardation plate 4, A pressure sensitive adhesive layer with a pressure sensitive adhesive and a second pressure sensitive adhesive layer provided with a second pressure sensitive adhesive layer 7 on one side of the second retardation film 5 were prepared and sequentially laminated with the first pressure sensitive adhesive layer 6 It is advantageous to laminate the first retardation plate 4 so that the third pressure sensitive adhesive layer 8 and the second retardation plate 5 overlap each other. In addition, for example, a polarizing plate with a pressure-sensitive adhesive is prepared in which a transparent protective layer 2 is bonded to one surface of a polarizer 1 and a first pressure-sensitive adhesive layer 6 is provided on the other surface of the polarizer 1, A pressure-sensitive adhesive sheet with a double-sided pressure-sensitive adhesive provided with a third pressure-sensitive adhesive layer 8 and a second pressure-sensitive adhesive layer 7 on both surfaces of a second retardation plate 5 was prepared, (6) and the third pressure-sensitive adhesive layer (8) of the pressure-sensitive adhesive layer with double-sided pressure-sensitive adhesive may be laminated with the first retardation plate (4) sandwiched therebetween.

The method of laminating the polarizer and the retarder in this way is not particularly limited and may be laminated by a conventionally known technique. Examples thereof include a method of laminating the retardation plate so that the slow axis of the retardation plate is orthogonal to or parallel to the polarized light transmission axis of the polarizer using a conjugation roll or a method of stacking the slow axis of the retardation plate with respect to the polarized light transmission axis of the polarizer at a predetermined angle Method. In particular, the composite polarizing plate of the present invention is effectively used to form a circularly polarized light or an elliptic polarization mode by stacking the polarized light transmission axis of the polarizer and the slow axis of the retarder so as to form a predetermined angle.

[Laminated Optical Member]

In the composite polarizing plate of the present invention, one or more optical layers showing different optical functions may be laminated to form a laminated optical member when used. Examples of other optical layers include a surface treatment layer such as a hard coat layer, an antireflection layer, and an antiglare layer, which are exemplified as layers that can be provided on the surface of the transparent protective layer 2, a reflective layer, a transflective layer, , A light collecting plate, and the like.

The reflective polarized composite polarizing plate is used in a liquid crystal display device which reflects incident light from the viewer side and displays the reflected light, so that a light source such as a backlight can be omitted, so that the liquid crystal display device can be easily made thin. Further, the transflective composite polarizing plate is used in a liquid crystal display device of the type that displays a transmissive type using a light source such as a backlight in a dark place in a reflective mode in a bright place. The reflective layer for forming the reflective composite polarizing plate can be formed by laying a foil or a vapor-deposited film made of a metal such as aluminum on the transparent protective layer 2 on the polarizer 1, for example. The transflective layer for forming the composite polarizing plate of the transflective type may be formed by a method of making the reflective layer as a half mirror or a method of attaching a reflective plate exhibiting light transmittance to a transparent protective layer 2 can do. On the other hand, the diffusion type composite polarizing plate has a function of diffusing incident light. For example, a method of applying a matte treatment to the transparent protective layer 2, a method of applying a fine particle-containing resin, A light diffusing layer having a micro concavo-convex structure is formed on the surface.

The composite polarizing plate for both reflection and diffusion is provided with a diffusing reflective layer by, for example, providing a reflective layer reflecting the concavo-convex structure on the fine concavo-convex structure surface of the diffusive composite polarizing plate. The reflective layer of the micro concavo-convex structure has an advantage that it can diffuse the incident light by diffuse reflection to prevent directivity and glare, and to prevent the light and shade from becoming uneven. The resin layer or film containing fine particles also has an advantage that it is possible to further suppress that the incident light and the reflected light are diffused when they penetrate through the layer to prevent the light and shade from becoming uneven. The reflective layer reflecting the surface micro concavo-convex structure can be formed, for example, by laying the metal directly on the surface of the micro concavo-convex structure by vapor deposition such as vacuum deposition, ion plating, sputtering, plating or the like. Examples of the fine particles to be blended for forming the surface micro concavo-convex structure include silica, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, indium oxide, cadmium oxide, antimony oxide and the like having an average particle diameter of 0.1 to 30 탆 Based fine particles, crosslinked or uncrosslinked polymers, and the like can be used.

The brightness enhancement film has a function of transmitting a part of incident natural light as linearly polarized light or circularly polarized light and reflecting the remainder to be reused, and is used for the purpose of improving brightness in a liquid crystal display device or the like. For example, a reflective linear polarized light separating sheet, a cholesteric liquid crystal polymer oriented film, or an alignment liquid crystal layer thereof, which are designed so that a plurality of thin film films having different anisotropy of refractive index have different anisotropies, A supported reflection type circularly polarized light separation sheet, and the like.

The light collecting plate is used for the purpose of optical path control or the like and may be formed of a prism array sheet, a lens array sheet, a dot mounting sheet, or the like.

Some of the various optical layers as described above can be provided directly on the surface of the transparent protective layer 2 by coating, vapor deposition or the like. In addition, the optical layer prepared as a film may be integrated with the composite polarizing plate using an adhesive or a pressure-sensitive adhesive. The adhesive or pressure-sensitive adhesive to be used for this purpose is not particularly limited, and a suitable one may be used. It is preferable to use a pressure-sensitive adhesive from the viewpoints of simplicity of the bonding operation and prevention of occurrence of optical deformation. Examples of the pressure-sensitive adhesive include acrylic, rubber, urethane, silicone, polyvinyl ether, and other base polymers. Specifically, the same materials as those used for the pressure-sensitive adhesive layers (6, 7, 8) can be used first. In particular, it is excellent in optical transparency, such as a pressure-sensitive adhesive having an acrylic base polymer (adhesive resin), maintains appropriate wettability and cohesive force, and is also excellent in adhesion to a substrate. Further, it has weather resistance and heat resistance, It is preferable to select and use those which do not cause the peeling problem.

[Image display device]

The composite polarizing plate or the laminated optical member of the present invention can be combined with various image display elements to form an image display apparatus. For example, on one side or both sides of the liquid crystal cell to form a liquid crystal display device. The liquid crystal cell to be used may be any liquid crystal cell, for example, an active matrix driven type represented by a thin film transistor type, a simple matrix driven type represented by a super twisted nematic type, A display device can be formed. When the composite polarizing plate or the laminated optical member of the present invention is provided on both sides of the liquid crystal cell, the same or different ones may be disposed on both sides.

3 is a schematic cross-sectional view showing an example of application of the composite polarizing plate and the laminated optical member of the present invention to a liquid crystal display device. In this example, a state in which the release film 9 is peeled off from the composite polarizer 11 shown in Fig. 1 is adhered to one surface (upper side in the figure) of the liquid crystal cell 30 on the side of the second pressure-sensitive adhesive layer 7 / Retardation plate 5 / first pressure-sensitive adhesive layer 6 / polarizer 1 / transparent protective layer 2 (second pressure-sensitive adhesive layer) (In this state, corresponding to the composite polarizing plate 11 shown in Fig. 1), and the other optical layer 18 is laminated on the outer side of the laminated optical member 20 is laminated on the second pressure- (7). In the liquid crystal display device of this example, when the upper side of the drawing is the viewer side and the backlight is disposed, a backlight is provided on the lower side of the drawing. In this case, the other optical layer 18 may be a reflection layer, a transflective layer, a brightness enhancement film, a light collecting plate, or the like. 3 shows an example in which the composite polarizing plate 11 shown in Fig. 1 is combined with the liquid crystal cell 30. In the case where the composite polarizing plate 12 shown in Fig. 2 is combined with a liquid crystal cell to form a liquid crystal display, It will be understood from the above description that the composite polarizing plate 11 of FIG. 2 is replaced with the composite polarizing plate 12 shown in FIG.

Further, the composite polarizing plate of the present invention is effectively used in a circular polarized light or an elliptic polarizing mode having an antireflection function in an image display apparatus other than a liquid crystal display apparatus, for example, an organic EL display apparatus. Of course, the image display apparatus to which the composite polarizing plate or the laminated optical member of the present invention is applied is not limited to those exemplified herein.

Example

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, the retardation value was a value measured at a wavelength of 589 nm, and the storage modulus, adhesion, haze value, gel fraction, retentivity, evaluation of the composite polarizing plate, average particle diameter and weight average molecular weight were measured according to the following methods Respectively.

(1) Method of measuring storage elastic modulus

The storage elastic modulus (G ') of the pressure-sensitive adhesive layer was measured at a temperature of 23 deg. C and 80 deg. C using a measuring device "DYNAMIC ANALYZER RDA II" manufactured by REOMETRIC Co., Under the condition of a frequency of 1 Hz.

(2) Adhesion (adhesion to alkali-free glass and polycarbonate)

Two samples of 25 mm wide and 100 mm long were cut out from the composite polarizing plate 13 and the release film 9 was peeled (thickness of the light-diffusing pressure-sensitive adhesive layer 25 탆), alkali-free glass ("1737" Or a polycarbonate resin plate ("Pure Ace C110-100 (trade name)" manufactured by Daijin Kasei Co., Ltd.), and then pressed in an autoclave made by Kurihara Seisakusho under the conditions of 0.5 MPa and 50 ° C for 20 minutes. Thereafter, the sample was allowed to stand in an environment of 23 ° C and a relative humidity of 50% for 24 hours, and then measured under the same conditions using a tensile tester (Tensilon manufactured by Orientec Co., Ltd.) under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 ° As an adhesive force.

(3) Haze value

The release film on the light-diffusing pressure-sensitive adhesive layer (alone) was peeled off, and the diffuse transmittance (Hd%) and the total light ray (Hd%) were measured using an integral-dated light transmittance measuring device ("NDH- The transmittance (Ht%) was measured and calculated by the following formula.

Haze value (%) = Hd / Ht × 100

(4) Gel fraction

The light-diffusing pressure-sensitive adhesive layer (alone) having a thickness of 25 占 퐉 was sampled at a size of 80 mm 占 80 mm to peel off the release film, wrapped in a polyester mesh (mesh size 200) Were weighed with a precision balance. The weight at this time is denoted by M1. The light-diffusing pressure-sensitive adhesive layer was immersed in an ethyl acetate solvent using a Soxhlet (extractor) and refluxed for 16 hours. Thereafter, the light-diffusing pressure-sensitive adhesive layer was taken out and air-dried for 24 hours in an environment of a temperature of 23 ° C and a relative humidity of 50%, and further dried in an oven at 80 ° C for 12 hours. The weight of this light-diffusing pressure-sensitive adhesive layer after drying was weighed with a precision balance. The weight at this time is M2. (M2 / M1) x 100 (%) is defined as the gel fraction.

(5) Retention force

A sample having a width of 25 mm and a length of 150 mm was cut out from the composite polarizing plate, and the peeled film was peeled off and attached to the test plate so that 25 mm x 25 mm (area) was contacted with the test plate. And the compound polarizer was pressed on a test plate. Thereafter, the sample was allowed to stand in an environment of 23 ° C. and a relative humidity of 50% for 2 hours. Using a holding force measuring apparatus described in Japanese Patent Application Laid-open No. 11-23449, the load was changed to 1000 g, Were measured. As a test plate, an SUS-304 steel sheet having a thickness of 1.5 to 2.0 mm specified in JIS-G-4305 was uniformly polished in the longitudinal direction with a water resistant abrasive paper No. 360 specified in JIS-R-6253. A digital indicator (" DEGIMATIC INDICATOR " manufactured by Mitsutoyo Co., Ltd.) was used as the measurement sensor of the holding force measuring apparatus.

(6) Evaluation of Composite Polarizer

The composite polarizing plate was adjusted to a size of 233 mm x 309 mm by a cutting device (super cutter "PN1-600" manufactured by Ogino Precision Machinery Co., Ltd.) and then bonded to an alkali-free glass [Corning Inc. "1737"], At a pressure of 0.5 MPa at 50 DEG C for 20 minutes. Thereafter, the mixture was placed under the conditions of the following durability conditions, and after 200 hours, observation was carried out using a 10 magnification magnifying glass, and durability was evaluated based on the following criteria.

A: No defects in the area of 0.3 mm or more from the outer peripheral edge at four sides.

A: No defects in the area of 0.6 mm or more from the outer peripheral edge on the four sides.

X: One of the four sides has a defect in appearance of the composite polarizer plate of 0.1 mm or more such as peeling, peeling, foaming, or streaking in an area of 0.6 mm or more from the outer peripheral edge.

≪ Durability condition &

80 ° C, 90 ° C, 60 ° C, 90% relative humidity,

A heat shock test for 30 minutes at -40 ° C to 85 ° C, 50 cycles

(7) Measurement of average particle diameter

The solution consisting of 1.2 g of the light-diffusing agent and 98.8 g of isopropyl alcohol was thoroughly stirred, and the resultant was used as a measurement sample and subjected to a centrifugal sedimentation optical transmission method using a centrifugal automatic particle size distribution analyzer ("CAPA-700" .

(8) Measurement of weight average molecular weight

The weight average molecular weight is a polystyrene reduced value measured by gel permeation chromatography (GPC) under the following conditions.

GPC measurement apparatus: HLC-8020 manufactured by Tosoh Corporation

GPC column (passed in the following order): manufactured by Toso Co., Ltd.

TSK guard column HXL-H

TSK gel GMHXL (× 2)

TSK gel G2000HXL

Measurement solvent: tetrahydrofuran

Measuring temperature: 40 ° C

In the following examples, the following were used as the pressure-sensitive adhesive layer.

Pressure-sensitive adhesive layer A: An organic solvent solution to which a urethane acrylate oligomer was added to a copolymer of butyl acrylate and acrylic acid and to which an isocyanate-based crosslinking agent had been further added was applied to a polyethylene terephthalate film (release film) And dried to form a thickness of 25 占 퐉. The storage elastic modulus of the pressure-sensitive adhesive layer A was 0.41 MPa at 23 占 폚 and 0.22 MPa at 80 占 폚.

Light-diffusing pressure-sensitive adhesive layer A: An organic solvent solution having the same composition as the pressure-sensitive adhesive layer A was blended with silicone resin particles having an average particle diameter of 4.5 占 퐉. The resultant was a polyethylene terephthalate film (release film) A pressure-sensitive adhesive on a sheet formed on a release-treated surface and dried to a thickness of 25 탆. The storage modulus of the light-diffusing pressure-sensitive adhesive layer A was 0.41 MPa at 23 占 폚 and 0.22 MPa at 80 占 폚. The haze value was 45%.

Light-diffusing agent-containing pressure-sensitive adhesive layer B: Silicone resin particles such as those blended in the light-diffusing pressure-sensitive adhesive layer A were compounded on the release-treated surface of a polyethylene terephthalate film (release film) , And an acrylic pressure-sensitive adhesive layer formed to a thickness of 25 占 퐉. The urethane acrylate oligomer is not blended. The pressure-sensitive adhesive layer containing a light-diffusing agent (referred to as a pressure-sensitive adhesive layer which does not satisfy the requirements of the present invention containing a light-diffusing agent, hereinafter the same) had a storage elastic modulus of 0.05 MPa at 23 캜 and 0.04 MPa at 80 캜 . The haze value was 45%.

[Example 1]

(a) a polarizing plate with a pressure-sensitive adhesive layer

A polarizing plate in which a transparent protective layer made of a triacetyl cellulose film having a thickness of 40 占 퐉 was bonded to one side of a polarizer made of a film having a thickness of 25 占 퐉 in which iodine was adsorbed and oriented on polyvinyl alcohol via an epoxy adhesive was prepared. On the side of the polarizer, the above pressure-sensitive adhesive layer A was laminated to produce a polarizing plate with a pressure-sensitive adhesive layer as a constitution of a transparent protective layer / polarizer / pressure-sensitive adhesive layer A / release film.

(b) retardation plate with pressure-sensitive adhesive layer

(? / 4 plate) made of a stretched film of norbornene resin and having a thickness of 40 占 퐉 and an in-plane retardation of 140 nm ("Essenafil" manufactured by Sekisui Chemical Co., Ltd.) The above-mentioned light-diffusing pressure-sensitive adhesive layer A was laminated to prepare a retarder having a pressure-sensitive adhesive layer.

(c) Fabrication of composite polarizer

After peeling off the release film from the polarizing plate with a pressure-sensitive adhesive layer prepared in (a) above, the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive layer- Was attached to the polarizing plate so that the slow axis of the retardation plate was 45 DEG with respect to the polarized light transmission axis of the polarizing plate to produce a composite polarizing plate. Fig. 4 is a schematic cross-sectional view showing the layer structure of the composite polarizing plate produced here. That is, the composite polarizing plate 13 produced in this example has the following layer structure.

The first pressure-sensitive adhesive layer 6 (25 占 퐉) / the retarder (? / 4 plate) 5 / the second pressure-sensitive adhesive layer 7a Adhesive layer, 25 占 퐉) / peeling film (9).

In FIG. 4, the pressure-sensitive adhesive layer 6 and the? / 4 plate 5 are displayed apart from each other so that the order of lamination can be understood. However, it will be understood from the above description that these layers are in close contact with each other. 5 and 6, the pressure-sensitive adhesive layer and the superimposed panel bonded to the pressure-sensitive adhesive layer are shown apart from each other, but the same effect as shown in Fig.

(d) Evaluation of composite polarizer

The release film 9 was peeled off from the composite polarizing plate 13 obtained in the step (c), and the exposed light-diffusing pressure-sensitive adhesive layer 7a was attached to a glass plate and subjected to autoclave treatment at 0.5 MPa and 50 캜 for 20 minutes Was performed to bring the complex polarizer plate into close contact with the glass plate. In this state, a heat shock test was performed in which one cycle was carried out in an atmosphere of -40 占 폚 for 30 minutes and then in an atmosphere of + 85 占 폚 for 30 minutes, and this cycle was repeated 50 times. No defects were observed in the composite polarizing plate after the test, and a good state was maintained.

[Example 2]

(a) a polarizing plate with a pressure-sensitive adhesive layer

A polarizing plate with a pressure-sensitive adhesive layer constituted of a transparent protective layer / polarizer / pressure-sensitive adhesive layer A / release film was produced in the same manner as in Example 1 (a).

(b) retardation plate with pressure-sensitive adhesive layer

(Manufactured by Sekisui Chemical Co., Ltd.) having an in-plane retardation of 270 nm, which is? / 2 with respect to the wavelength? Of light, of a stretched film of a norbornene resin and having a thickness of 33 占 퐉 (? / 2 plate) in which an acrylic pressure-sensitive adhesive having a thickness of 15 占 퐉 was laminated on one side of a polarizing plate (? / 2 plate) (? / 4 plate) (? / 4 plate, manufactured by Sekisui Chemical Co., Ltd.) having an in-plane retardation of 90 nm of? / 4 with respect to the wavelength? Of light and having a thickness of 28 占 퐉 Sensitive adhesive layer A was laminated on the surface of the pressure-sensitive adhesive layer to prepare a pressure-sensitive adhesive layer-attached retarder (? / 4 plate).

(c) Fabrication of composite polarizer

After peeling the release film from the polarizing plate with a pressure-sensitive adhesive layer prepared in the above (a), the? / 2 plate side (? / 2 plate) of the retarder (? / 2 plate) (The side on which the pressure-sensitive adhesive layer was not provided) was laminated so that the slow axis of the? / 2 plate was 15 ° with respect to the polarized light transmission axis of the polarizer, and further the pressure- The laminated retardation plate (? / 4 plate) was placed on the? / 4 plate side (the side where the light-diffusive pressure-sensitive adhesive layer was not provided) (75 [deg.] With respect to the polarization transmission axis of the polarizing plate) to prepare a composite polarizing plate. Fig. 5 is a schematic sectional view showing the layer structure of the composite polarizing plate produced here. That is, the composite polarizing plate 14 produced in this example has the following layer structure.

The first pressure-sensitive adhesive layer 6 (25 占 퐉) / the retardation plate (? / 2 plate) 4 / the third pressure-sensitive adhesive layer 8 (15 占 퐉) / Retardation plate (? / 4 plate) 5 / second pressure-sensitive adhesive layer 7a (light-diffusing pressure-sensitive adhesive layer, 25 占 퐉) / release film (9)

(d) Evaluation of composite polarizer

The composite polarizer obtained in (c) above was subjected to the heat shock test as in Example 1 (d). In this example as well, no defects were observed in the composite polarizing plate after the test and a satisfactory state was maintained.

[Example 3]

(a) a polarizing plate with a pressure-sensitive adhesive layer

A polarizing plate with a pressure-sensitive adhesive layer constituted of a transparent protective layer / polarizer / pressure-sensitive adhesive layer A / release film was produced in the same manner as in Example 1 (a).

(b) retardation plate with pressure-sensitive adhesive layer

(Manufactured by Sekisui Chemical Co., Ltd.) having an in-plane retardation of 270 nm, which is? / 2 with respect to the wavelength? Of light, of a stretched film of a norbornene resin and having a thickness of 33 占 퐉 (? / 2 plate) having a pressure-sensitive adhesive layer was prepared by sticking the light-diffusing pressure-sensitive adhesive layer A on one side of the laminate (? / 2 plate) (? / 4 plate) made by Sekisui Chemical Co., Ltd. (? / 4 plate) having an in-plane retardation of 90 nm, which is? / 4 with respect to the wavelength? Of light, Sensitive adhesive layer-laminated retardation plate (lambda / 4 plate) having an acrylic pressure-sensitive adhesive laminated thereon was prepared.

(c) Fabrication of composite polarizer

After peeling the release film from the polarizing plate with a pressure-sensitive adhesive prepared in the above (a), the? / 2 plate side (? / 2 plate) of the retardation plate (? / 2 plate) (The side on which the light-diffusing pressure-sensitive adhesive layer is not provided) is bonded so that the slow axis of the? / 2 plate is 15 ° with respect to the polarized light transmission axis of the polarizer, and the decompression pressure The retardation plate with an adhesive layer (? / 4 plate) was placed on the? / 4 plate side (the side on which the pressure-sensitive adhesive layer was not provided) so that the slow axis of the? / 4 plate was 60 degrees 75 ° with respect to the polarization transmission axis of the polarizing plate) to prepare a composite polarizing plate. Fig. 6 is a schematic cross-sectional view showing the layer structure of the composite polarizing plate produced here. That is, the composite polarizing plate 15 produced in this example has the following layer structure.

The first pressure-sensitive adhesive layer 6 (25 占 퐉) / the retarder (? / 2 plate) 4 / the third pressure-sensitive adhesive layer 8a Retardation plate (? / 4 plate) 5 / second pressure-sensitive adhesive layer (8) (15 占 퐉) / peeling film (9).

(d) Evaluation of composite polarizer

The composite polarizer obtained in (c) above was subjected to the heat shock test as in Example 1 (d). In this example as well, no defects were observed in the composite polarizing plate after the test and a satisfactory state was maintained.

[Comparative Example 1]

(B) of Example 1, the light-diffusing pressure-sensitive adhesive layer A to be laminated on one side of the? / 4 plate was changed to the light-diffusing-agent-containing pressure-sensitive adhesive layer B, To prepare a polarizing plate. The obtained composite polarizing plate was subjected to the heat shock test as in (d) of Example 1. Bubbles were observed in the composite polarizer after the test.

[Comparative Example 2]

(B) of Example 2 was changed to a light-diffusing pressure-sensitive adhesive B containing a light-diffusing pressure-sensitive adhesive A which was laminated on one side of a lambda / 4 plate, and in the same manner as in Example 2, Respectively. The obtained composite polarizing plate was subjected to the heat shock test as in (d) of Example 1. Bubbles were observed in the composite polarizer after the test.

[Comparative Example 3]

(B) of Example 3, the light-diffusing pressure-sensitive adhesive A to be laminated on one side of the? / 2 plate was changed to the pressure-sensitive adhesive B containing the light-diffusing agent, Sensitive adhesive B containing a light-diffusing agent having a small storage modulus of elasticity was disposed between the pressure-sensitive adhesive B and the pressure-sensitive adhesive B, and a composite polarizing plate was produced in the same manner as in Example 3 except that the pressure- The obtained composite polarizing plate was subjected to the heat shock test as in (d) of Example 1. Bubbles were observed in the composite polarizer after the test.

Table 1 summarizes the main conditions and results of Examples 1 to 3 and Comparative Examples 1 to 3 above. As a representative example of the sample after the heat shock test in these examples and comparative examples, an enlarged picture of the sample of Example 2 viewed from the transparent protective layer side of the polarizer is shown in Fig. 8 (A), and a sample of Comparative Example 2 And an enlarged view of the polarizer viewed from the side of the transparent protective layer is shown in Fig. 8 (B). In FIG. 8, a plurality of bubbles appearing in the shape of an ellipse are observed in the sample of Comparative Example 2 shown in (B), while the bubbles are not observed in the sample of Example 2 shown in (A) .

The light-diffusing-agent-containing adhesive material layer C to L:

An ethyl acetate solution (solid content: 14% by weight) of a viscous material having a composition (solid content) shown in Table 2 was prepared and coated on a release layer of a polyethylene terephthalate release film (SP-PET3811, Coated with a knife coater to a thickness of 25 mu m, and dried at 90 DEG C for 1 minute to form a light-diffusing-agent-containing adhesive material layer C to L. [

Light-diffusing agent-free adhesive material layer C to L:

An ethyl acetate solution (solid content 14% by weight) of a sticky material having a composition excluding the silicon beads was prepared from the composition (solid content) shown in Table 2 and a polyethylene terephthalate peeling film (SP-PET3811, ] With a knife coating machine to a thickness of 25 mu m after drying, and then dried at 90 DEG C for 1 minute to form layers C to L of a light-diffusing agent-free adhesive material.

The light-diffusing pressure-sensitive adhesive layers C to J and the light-diffusing-agent-containing pressure-sensitive adhesive layers K to L:

The light-diffusing pressure-sensitive adhesive layer (C) J and the light-diffusing-containing pressure-sensitive adhesive layer (K) L were obtained by irradiating ultraviolet rays to the light- These pressure-sensitive adhesive layers were used for calculating the storage elastic modulus, haze value, and gel fraction values in Table 3.

<Ultraviolet irradiation condition>

· Electrodeless luminescence H bulb used by Fusion

Illumination 600 mW / cm 2, light quantity 150 mJ / cm 2

The ultraviolet light intensity and the light amount were measured by "UVPF-36" manufactured by IGraphics.

(a ') With a PSA layer containing a light-diffusing agent [

A polarizing plate in which a transparent protective layer made of a triacetyl cellulose film having a thickness of 40 占 퐉 was bonded to one side of a polarizer made of a film having a thickness of 25 占 퐉 in which iodine was adsorbed and oriented on polyvinyl alcohol via an epoxy adhesive was prepared. The above-mentioned PSA layer containing a light-diffusing agent was laminated on the polarizer side according to Table 3 to prepare a polarizing plate with a PSA layer containing a light-diffusing agent as a constituent of a transparent protective layer / polarizer / light-diffusing agent- .

(b ') retarder having no adhesive agent layer

(? / 4 plate) made of a stretched film of a norbornene resin and having a thickness of 40 占 퐉 and an in-plane retardation of 140 nm (? / 4 plate, manufactured by Sekisui Chemical Co., Ltd.) A retardation plate with a light diffusing agent-free pressure-sensitive adhesive material layer as a constituent of a retardation film (? / 4 plate) / light-diffusing agent-free pressure-sensitive adhesive material layer / release film was prepared.

(c ') Production of composite polarizer

After peeling off the release film from the polarizing plate with a PSA layer containing a light-diffusing agent prepared in the above (a '), the pressure-sensitive adhesive material layer containing no light-diffusing agent- The retardation plate side (side not provided with the light-diffusing agent-containing viscous material layer) of the attached retardation plate was bonded so that the slow axis of the retardation plate was at 45 degrees with respect to the polarized light transmission axis of the polarizing plate.

Next, a composite polarizing plate corresponding to Examples 4 to 11 and Comparative Examples 4 to 5 in Table 4 was prepared by irradiating ultraviolet rays from the side of the release film adhering to the retardation plate under the following conditions.

<Ultraviolet irradiation condition>

· Electrodeless lamp H bulb manufactured by Fusion Co., Ltd.

Illumination 600 mW / cm 2, light quantity 150 mJ / cm 2

The ultraviolet light intensity and the light amount were measured using "UVPF-36" manufactured by IGraphics.

Fig. 7 shows the layer structure of the composite polarizing plate produced here as a schematic sectional view. That is, the composite polarizing plate 13 produced in this example has the following layer structure.

Examples 4 to 11

Sensitive adhesive layer (light-diffusing pressure-sensitive adhesive layer, 25 占 퐉) / retarder (? / 4 plate) 5 / second pressure-sensitive adhesive layer (2) / polarizer 1 / 6) (pressure-sensitive adhesive layer, 25 占 퐉) / release film (9).

Comparative Examples 4 to 5

Sensitive adhesive layer (2) / polarizer (1) / first pressure-sensitive adhesive layer (7a) (pressure-sensitive adhesive layer containing a light diffusing agent, 25 m) / retarder (? / 4 plate) (6) (pressure-sensitive adhesive layer, 25 m) / release film (9).

(d ') Evaluation results of the composite polarizer

As shown in Table 4, the composite polarizing plates of Examples 4 to 11 satisfying the requirements of the present invention were more durable than the composite polarizing plates of Comparative Examples 4 to 5, which did not satisfy the requirements of the present invention.

Yes No Floor composition The light-diffusing pressure-sensitive adhesive layer or
Sensitive adhesive layer containing a light-diffusing agent Heat shock
Test result Kinds Storage modulus 23 ℃ 80 ℃ Example 1 4 A 0.41 MPa 0.22 MPa ○ Example 2 5 A 0.41 MPa 0.22 MPa ○ Example 3 6 A 0.41 MPa 0.22 MPa ○ Comparative Example 1 4 B 0.08 MPa 0.06 MPa × Comparative Example 2 5 B 0.08 MPa 0.06 MPa × Comparative Example 3 6 B 0.08 MPa 0.06 MPa ×

Composition of the adhesive material (parts by weight) The light-diffusing pressure-sensitive adhesive layer or the pressure-sensitive adhesive layer containing the light- Acrylic
Copolymer ^{1 )}
(A) Polyfunctional acrylate series
Monomers ^{2 )}
(B) Photopolymerization
Initiator ^{3 )} Isocyanate crosslinking agent ^{4 )}
(C) Silane coupling agent ^{5 )}
(D) silicon
Bead ^{6 )} C 100 15 1.5 0.3 0.2 4.7 (3.86) D 100 15 1.5 0.3 0.2 9.3 (7.36) E 100 15 1.5 0.3 0.2 14.0 (10.7) F 100 15 1.5 0.3 0.2 18.6 (13.7) G 100 15 1.5 0.3 0.2 37.3 (24.2) H 100 15 1.5 0.3 0.2 3.0 (2.5) I 100 15 1.5 0.3 0.2 7.0 (5.65) J 100 15 1.5 0.3 0.2 21.0 (15.2) K 100 0 0 0 0.2 3.0 (2.90) L 100 0 0 0 0.2 7.0 (6.51)

(week)

1) Acrylic copolymer: Copolymer having a weight average molecular weight of 1,800,000, obtained by polymerizing butyl acrylate and acrylic acid in a weight ratio of 95: 5 according to a conventional method

2) polyfunctional acrylate monomer: tris (acryloxyethyl) isocyanurate, molecular weight = 423, trifunctional type (Aronix M-315,

3) Photopolymerization initiator: a mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone in a weight ratio of 1: 1, "Irgacure 500" manufactured by Chiba Specialty Chemicals Co.,

4) Isocyanate-based crosslinking agent: Trimethylolpropane-modified tolylene diisocyanate ("Colonate L" manufactured by Japan Polyurethane Co., Ltd.)

5) Silane coupling agent: 3-glycidoxypropyltrimethoxysilane ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.)

6) Silicone beads: Precursory silicon fine particles (TOUSPLE 145, manufactured by GE Toshiba Silicones, average particle diameter 4.5 占 퐉)

The light-diffusing pressure-sensitive adhesive layer or the pressure-sensitive adhesive layer containing the light- The performance of the pressure-sensitive adhesive layer Storage modulus (MPa) Adhesive force (N / 25mm) Haze value
(%) Gel fraction
(%) retention
(탆) 23 ℃ 80 ℃ Non-alkali glass Large polycarbonate C 0.945 0.458 37.5 48.0 37.9 98.3 53.0 D 0.998 0.495 35.5 46.0 58.7 98.6 48.0 E 1.050 0.530 29.8 38.5 70.4 99.2 48.0 F 1.130 0.578 29.0 37.5 78.5 98.9 35.0 G 1.370 0.707 24.0 31.0 89.2 98.4 36.5 H 1.010 0.480 19.0 24.5 23.9 96.6 54.5 I 0.890 0.460 16.5 21.5 43.9 96.9 52.0 J 1.010 0.490 14.0 18.2 75.0 98.3 37.5 K 0.140 0.090 12.5 ⁷⁾ 16.0 25.8 0.4 > 25000 L 0.140 0.090 13.0 ⁷⁾ 17.0 47.0 0.3 > 25000

(week)

7) Residue of adhesive is confirmed.

Floor composition Sensitive adhesive layer containing a light-diffusing or light-diffusing agent The pressure-sensitive adhesive layer (containing no light-diffusing agent) Evaluation of Composite Polarizer durability 90 ° C 80 ℃ 60 ° C
90% RH Heat shock Example 4 7 C C ◎ ◎ ◎ ◎ Example 5 7 D D ◎ ◎ ◎ ◎ Example 6 7 E E ◎ ◎ ◎ ◎ Example 7 7 F F ◎ ◎ ◎ ◎ Example 8 7 G G ◎ ◎ ◎ ◎ Example 9 7 H H ◎ ◎ ◎ ◎ Example 10 7 I I ◎ ◎ ◎ ◎ Example 11 7 J J ◎ ◎ ◎ ◎ Comparative Example 4 7 K K ○ ○ × × Comparative Example 5 7 L L ○ ○ × ×

Industrial availability

A composite polarizing plate having a polarizer, a retarder, and a pressure-sensitive adhesive layer is obtained by laminating a laminated optical member laminated on another optical layer and an image display apparatus obtained by combining the compound polarizing plate or the laminated optical member with an image display element such as a liquid crystal cell Can be applied.

One… Polarizers,
2, 3 ... Transparent protective layer,
4… Retardation plate (may be? / 2 plate),
5 ... Retardation plate (which may be? / 4 plate),
Six, seven, eight ... A pressure-sensitive adhesive layer (which may be a light-diffusing pressure-sensitive adhesive layer)
7a, 8a ... A light-diffusing pressure-sensitive adhesive layer,
9 ... Peeling film,
11-15 ... Complex polarizer,
18 ... An optical layer showing other optical functions,
20 ... The laminated optical member,
30 ... Liquid crystal cell,
40 ... Polarizer (conventional),
41 ... Complex polarizing plate (conventional).

Claims (20)

At least one retardation plate is laminated through a first pressure sensitive adhesive layer disposed on one side of a polarizer made of a polyvinyl alcohol based resin film and directly on the other side of the polarizer, And a second pressure-sensitive adhesive layer disposed on the outer side of the retarder plate,
Wherein at least the first pressure-sensitive adhesive layer among the pressure-sensitive adhesive layers existing between the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer comprises a pressure-sensitive adhesive layer comprising (A) an acrylic copolymer and (B) Wherein the pressure-sensitive adhesive layer is a light-diffusing pressure-sensitive adhesive layer which is obtained by irradiating an active energy ray to a pressure-sensitive adhesive material in which a light-diffusing agent is dispersed in a resin, and exhibits a storage elastic modulus of 0.3 to 10 MPa at 23 占 폚. The method according to claim 1,
Wherein the light-diffusing pressure-sensitive adhesive layer exhibits a storage modulus of 0.15 to 10 MPa at 80 캜. The method according to claim 1 or 2,
Wherein the retardation plate is one piece. The method according to claim 1 or 2,
Wherein two retardation plates are laminated, and both retardation plates are bonded through a third pressure-sensitive adhesive layer. The method according to claim 1 or 2,
Wherein the light-diffusing pressure-sensitive adhesive layer contains a light-diffusing agent having an average particle diameter of 0.1 to 20 占 퐉 and a haze value of 5% or more. The method according to claim 1 or 2,
Wherein the light-diffusing pressure-sensitive adhesive layer exhibits a storage modulus of 0.3 to 10 MPa at 80 캜. The method of claim 6,
Wherein the gel fraction of the light-diffusing pressure-sensitive adhesive layer is 60% or more. The method according to claim 1 or 2,
(B) a composite polarizer wherein the active energy ray-curable compound is a polyfunctional (meth) acrylate monomer having a molecular weight of less than 1,000. The method of claim 8,
Wherein the multifunctional (meth) acrylate monomer has a cyclic structure. The method of claim 9,
Wherein the polyfunctional (meth) acrylate monomer has an isocyanurate structure. The method according to claim 1 or 2,
(A) an acrylic copolymer and (B) an active energy ray-curable compound in a weight ratio of 100: 1 to 100: 100. The method according to claim 1 or 2,
Wherein the adhesive material further comprises (C) a crosslinking agent. The method according to claim 1 or 2,
Wherein the adhesive material further comprises (D) a silane coupling agent. The method according to claim 1 or 2,
The light-diffusing pressure-sensitive adhesive layer has a haze value of 20 to 90%. The method according to claim 1 or 2,
The light-diffusing pressure-sensitive adhesive layer has a thickness of 1 to 40 탆. A laminated optical member characterized by comprising a laminate of the composite polarizing plate according to claim 1 and an optical layer exhibiting different optical functions. An image display device comprising an image display element, the composite polarizing plate according to claim 1, or the laminated optical element according to claim 16. delete delete delete

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