JP5571953B2 - Composite polarizing plate, laminated optical member, and image display device using them - Google Patents

Description

  The present invention relates to a composite polarizing plate including a polarizer, a retardation plate, 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 device in which the composite polarizing plate or laminated optical member is combined with an image display element such as a liquid crystal cell. .

  Conventionally, liquid crystal display devices have been used in desktop calculators, electronic timepieces, and the like, but their use has been rapidly expanding in recent years. That is, liquid crystal display devices have been used from mobile devices such as mobile phones to large televisions regardless of screen size. In addition to liquid crystal display devices, organic electroluminescence (organic EL) display devices also tend to increase mainly in mobile applications. The polarizing plates used in these image display apparatuses are not only in increasing demand but also required to have performance suitable for each application.

  The polarizing plate generally used in the image display apparatus as described above is a triacetyl cellulose film via a liquid adhesive on both sides of a polarizer in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol resin film. It is manufactured with the structure which laminated | stacked the transparent protective layer represented by. In this state or, if necessary, in a form in which various optical layers such as a phase difference plate and an optical compensation plate exhibiting predetermined optical characteristics are bonded via an adhesive or a pressure sensitive adhesive, a liquid crystal cell, an organic EL element, etc. The image display element is used by bonding.

  FIG. 9 is a cross-sectional schematic view showing a general example of such a conventional polarizing plate and a composite polarizing plate having a retardation plate laminated thereon. That is, the transparent protective layers 2 and 3 are provided on both surfaces of the polarizer 1 to constitute the polarizing plate 40. In addition, a phase difference plate 5 is bonded to one transparent protective layer 3 via a pressure-sensitive adhesive layer 6, and further, a pressure-sensitive adhesive layer 7 for bonding to an image display element or the like on the outer side. Are provided to constitute the composite polarizing plate 41. On the outside of the pressure-sensitive adhesive layer 7, a release film 9 is usually provided to temporarily protect the surface of the pressure-sensitive adhesive layer 7 until it is bonded to an image display element or the like.

  In recent years, image display devices for mobile use such as mobile phones have been made thinner and slimmer from the viewpoint of design and portability. As a matter of course, there is a demand for further reduction in thickness and weight of the polarizing plate used there. In addition, since mobile devices are used in various places due to the use of mobile devices, there is a demand for durability that is higher than conventional ones while having a thin and lightweight configuration. Further, there is a demand for a composite polarizing plate having a thin structure that can secure brightness when viewed from the front and when viewed from an oblique direction and is less likely to cause blurring or blurring of a display image.

  Therefore, instead of the configuration in which the transparent protective layers 2 and 3 are provided on both surfaces of the polarizer 1 as shown in FIG. 9, the transparent protective layer 3 on the side to be bonded to another optical film such as the retardation plate 5 is provided. There is also an attempt to reduce the thickness of the polarizing plate by omitting and laminating another optical film such as the retardation plate 5 directly on the polarizer 1 via an adhesive or a pressure sensitive adhesive. However, in this case, especially when placed in a high temperature environment or when a high temperature environment and a low temperature environment are repeated, the dimensional change accompanying the expansion and contraction of the polarizer 1 becomes large, and it is difficult to obtain sufficient durability. There was a problem.

  On the other hand, the proposal which replaces the triacetyl cellulose film as a transparent protective layer with other resin is also made conventionally. For example, in JP-A-2000-199819 (Patent Document 1), a resin solution with a solvent that does not dissolve the film is applied to one or both sides of a polarizer made of a hydrophilic polymer to provide a transparent thin film layer. It is also disclosed that a protective layer made of a transparent film is disposed on the transparent thin film layer. Japanese Patent Application Laid-Open No. 2000-32430 (Patent Document 2) discloses that a cyclic olefin is formed on at least one surface of a polyvinyl alcohol polarizer through an adhesive composed of a mixture of a polyvinyl alcohol adhesive and a two-component adhesive. A polarizing plate in which a protective film made of a resin is laminated is disclosed. JP 2001-305345 A (Patent Document 3) discloses a protective film made of norbornene resin on at least one surface of a polarizer made of polyvinyl alcohol sheet with an aqueous polymer-isocyanate adhesive interposed therebetween. A laminated polarizing plate is disclosed.

  If the transparent film or the cyclic olefin-based resin film (norbornene-based resin film is also substantially synonymous) disclosed in these Patent Documents 1 to 3 is constituted by a film having a function of a retardation plate, it is bonded to the image display element. The number of members can be reduced to obtain a thin polarizing plate. However, when an adhesive is used for laminating the polarizer and the transparent polymer film, the adhesive is applied to the polarizer and the polymer film is laminated and cured, so that the optical axis of the film is polarized. Since it is difficult to laminate so as to be at a constant angle with respect to the child axis, there is a problem in forming an elliptical or circular polarization mode composite polarizing plate that is particularly useful for image display devices for mobile applications. there were. In addition, if the polarizer and the transparent polymer film are simply bonded together via a transparent adhesive, in the image display device to which the polarizer is applied, in the transmissive type, the shadow of the backlight and the unevenness of the image display element are generated. In the transmissive type, a light interference phenomenon occurs due to the unevenness on the surface of the reflecting plate, so that the display image may be blurred or blurred, and there is a limit to improving the visibility.

  Furthermore, it is also known that a norbornene-based resin film as described above is bonded to a polarizer using a pressure-sensitive adhesive (pressure-sensitive adhesive). For example, JP-A-6-511117 (Patent Document 4) discloses a polarizing plate in which a thermoplastic saturated norbornene resin film is laminated as a protective layer on at least one surface of a polarizer. In JP-A-8-43812 (Patent Document 5), in a polarizing plate in which protective films are laminated on both sides of a polarizer, at least one of the protective films has a function of a retardation plate at the same time. As an example of a protective film having a retardation plate function, a thermoplastic norbornene-based resin is cited. In these patent documents 4 and 5, as an adhesive (pressure-sensitive adhesive) used for laminating a polarizer and a norbornene resin film, natural rubber, synthetic rubber / elastomer, vinyl chloride / vinyl acetate copolymer, polyvinyl Examples include alkyl ethers, polyacrylates, modified polyolefin resin adhesives, and the like.

  In order to eliminate the blur and blur of the display image as described above and improve visibility, it is conceivable to provide a light diffusive pressure-sensitive adhesive layer in which a light diffusing agent is blended with an adhesive. However, a light diffusive pressure-sensitive adhesive layer obtained by mixing a light diffusing agent with a general pressure-sensitive adhesive sometimes causes a problem in durability due to insufficient cohesive force of the base pressure-sensitive adhesive.

  Therefore, a polarizing plate for mobile use that is desired to be thinner and lighter by reducing the number of constituent members is required to have a polarizing plate that is thin and has good durability and excellent visibility. On the other hand, development of a thin polarizing plate using a pressure-sensitive adhesive having a high degree of manufacturing freedom is also demanded in the laminating step with a polymer film having optical properties or another optical layer.

JP 2000-199819 A JP 2000-32430 A JP 2001-305345 A JP-A-6-511117 JP-A-8-43812

It is a cross-sectional schematic diagram which shows an example of a layer structure about the composite polarizing plate of this invention. It is a cross-sectional schematic diagram which shows the other example of a layer structure about the composite polarizing plate of this invention. It is a cross-sectional schematic diagram which shows the example in the case of applying the composite polarizing plate and laminated optical member of this invention to a liquid crystal display device. 2 is a schematic cross-sectional view showing a layer structure of a composite polarizing plate produced in Example 1 and Comparative Example 1. FIG. 6 is a schematic cross-sectional view showing a layer structure of a composite polarizing plate produced in Example 2 and Comparative Example 2. FIG. 6 is a schematic cross-sectional view showing a layer structure of a composite polarizing plate produced in Example 3 and Comparative Example 3. FIG. It is a cross-sectional schematic diagram which shows the layer structure of the composite polarizing plate produced in Example 4-11 and Comparative Example 4-5. (A) is the composite polarizing plate obtained in Example 2, and (B) is the composite polarizing plate obtained in Comparative Example 2, and the sample after the heat shock test is viewed from the transparent protective layer side of the polarizer. It is an enlarged photo. It is a cross-sectional schematic diagram which shows an example of a layer structure about the conventional composite polarizing plate.

Explanation of symbols

1 ... Polarizer,
2, 3 ... Transparent protective layer,
4 ... retardation plate (can be a λ / 2 plate),
5 ... retardation plate (can be a λ / 4 plate),
6,7,8 ... Pressure sensitive adhesive layer (may be light diffusive pressure sensitive adhesive layer),
7a, 8a: Light diffusive pressure sensitive adhesive layer,
9 …… Peeling film,
11-15 ... Composite polarizing plate,
18 ... an optical layer exhibiting other optical functions,
20 ... laminated optical member,
30 ... Liquid crystal cell,
40: Polarizing plate (conventional),
41 …… Composite polarizing plate (conventional).

  An object of the present invention is to arrange a transparent protective layer on one side of a polarizer and to laminate a retardation plate on the other side through a pressure-sensitive adhesive layer, thereby reducing the thickness and weight by reducing the number of members. In the composite polarizing plate, the pressure sensitivity existing from the pressure-sensitive adhesive layer joining the polarizer and the retardation plate to the pressure-sensitive adhesive layer provided outside the retardation plate (including these). By constituting at least one of the adhesive layers with a light diffusing agent blended, the brightness when the image display device to which it is applied is viewed from the front and obliquely is ensured. The display image is less likely to bleed or blur, and the pressure-sensitive adhesive layer containing such a light diffusing agent is further improved to repeat the high-temperature and low-temperature environments when placed under a high-temperature environment. A thin structure with good durability even when It is to provide a polarizing plate.

  Furthermore, another object of the present invention is to provide a laminated optical member excellent in durability and visibility by combining such a composite polarizing plate with an optical layer exhibiting other optical functions. Still another object of the present invention is to provide an image display device 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 object, the composite polarizing plate of the present invention has a first feeling in which a transparent protective layer is disposed on one side of a polarizer made of a polyvinyl alcohol-based resin film and directly disposed on the other side of the polarizer. At least one phase difference plate is laminated via a pressure adhesive layer, and a second pressure sensitive adhesive layer is disposed outside the phase difference plate located on the side farthest from the polarizer. Among the pressure-sensitive adhesive layers existing between the pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, at least the first pressure-sensitive adhesive layer is (A) an acrylic copolymer. And (B) an adhesive material in which a light diffusing agent is dispersed in an adhesive resin made of an active energy ray-curable compound, and irradiated with active energy rays, and at 23 ° C., 0.3 to 10 MPa. Consists of a light diffusive pressure sensitive adhesive layer that exhibits a storage modulus of That.

Thus, by laminating the retardation plate on one surface of the polarizer via the first pressure-sensitive adhesive layer, the composite polarizing plate is reduced in thickness and weight by reducing the number of members. In addition, the light diffusing agent includes 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. Consists of blended materials to ensure brightness when viewed from the front and oblique directions of an image display device to which the composite polarizing plate is applied, and display images are less likely to bleed or blur. The visibility is improved. Furthermore, the pressure sensitive adhesive layer in which the light diffusing agent is blended is a light diffusible pressure sensitive adhesive having a relatively high storage elastic modulus of 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. By comprising the adhesive layer, durability problems due to insufficient cohesive force of the pressure-sensitive adhesive layer are suppressed when placed in a high temperature environment or when a high temperature environment and a low temperature environment are repeated.

In the above composite polarizing plate, the pressure-sensitive adhesive layer present in at least two layers includes at least a first pressure-sensitive adhesive layer containing a light diffusing agent, and at 23 ° C., 0.3 to 10 MPa, preferably 80 ° C. may be made of a light diffusing pressure-sensitive adhesive layer showing a storage modulus Oite 0.15~10MPa in, usually, a layer of that may be satisfied this condition. The light diffusable pressure-sensitive adhesive layer has a haze value of 5% or more. If the haze value is 5% or more, the visibility becomes good. Furthermore, it is preferably 90% or less from the viewpoint of durability and adhesive properties. From the above points, the haze value is preferably in the range of 20 to 90%, particularly preferably 30 to 75%. Furthermore, the light diffusive pressure-sensitive adhesive layer preferably has a thickness in the range of 1 to 40 μm. If the thickness is less than 1 μm, the adhesive properties and durability may be insufficient, and if it exceeds 40 μm, problems such as residual solvent may occur. From such a viewpoint, the thickness of the light diffusable pressure-sensitive adhesive layer is preferably 3 to 25 μm. As described above, the first pressure-sensitive adhesive layer that joins the polarizer and the retardation plate contains a light diffusing agent , and its storage elastic modulus is 0.3 to 10 MPa at 23 ° C., preferably 80 ° C. to take a value between 0.15~10MPa in. When the storage elastic modulus at 23 ° C. is 0.3 MPa or more, even in the composite polarizing plate of the present invention having a transparent protective layer only on one side of the polarizer, excellent dimensional stability under a high temperature environment can be obtained. Moreover, it is because sufficient adhesiveness with a polarizer or a phase difference plate can be exhibited when the storage elastic modulus at 23 ° C. is 10 MPa or less.

In the above composite polarizing plate, when there is one retardation plate, the first pressure-sensitive adhesive layer existing between the polarizer and the retardation plate, and the second pressure-sensitive material disposed outside the retardation plate Among the adhesive layers, at least the first pressure-sensitive adhesive layer contains a light diffusing agent and exhibits a storage elastic modulus of 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. A light diffusable pressure sensitive adhesive layer is provided .

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 bonded via a third pressure-sensitive adhesive layer. In this case, a first pressure-sensitive adhesive layer present between the polarizer and the retardation plate, a second pressure-sensitive adhesive layer disposed outside the retardation plate located on the side far from the polarizer, and two sheets Among the third pressure-sensitive adhesive layers for joining the retardation plates, at least the first pressure-sensitive adhesive layer contains a light diffusing agent and is 0.3 to 10 MPa at 23 ° C., preferably 80 ° C. so that the light diffusing pressure-sensitive adhesive layer showing a storage modulus 0.15~10MPa in.

  In these composite polarizing plates, the second pressure-sensitive adhesive layer disposed outside the retardation plate located on the side farthest from the polarizer is convenient for handling until it is bonded to the adherend. Therefore, it is preferable that a release film treated with a release agent such as silicone is present on the exposed surface.

  The laminated optical member of the present invention is composed of a laminate of any one of the composite polarizing plates specified above and an optical layer exhibiting another optical function. 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, a reflection layer, a transflective layer, and a brightness enhancement film.

  For example, in the above composite polarizing plate, a surface treatment layer such as a hard coat layer, an antireflection layer, or 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. it can. Further, in the above-described composite polarizing plate, a reflective layer or a transflective layer is 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, so that the reflective or transflective composite is formed. It can be set as a polarizing plate. Further, in the above-described composite polarizing plate, a brightness enhancement film is bonded to the opposite side of the surface of the transparent protective layer disposed on one side of the polarizer in contact with the polarizer via an adhesive or a pressure sensitive adhesive. It can also be set as the composite polarizing plate which can recycle the light.

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

  In the composite polarizing plate of the present invention, since the retardation plate is laminated on one surface of the polarizer via the first pressure-sensitive adhesive layer, the number of members is reduced, and the thickness and weight are reduced. In addition, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer disposed on the outer side of the retardation plate located on the side farthest from the polarizer, are present between the two. At least one of the pressure adhesive layers contains a light diffusing agent, and the pressure sensitive adhesive layer containing the light diffusing agent exhibits a predetermined storage elastic modulus at 23 ° C., preferably at 23 ° C. and 80 ° C. Since it is composed of a light diffusive pressure-sensitive adhesive layer, it exhibits high durability and excellent visibility.

  Furthermore, the laminated optical member of the present invention is obtained by laminating an optical layer exhibiting other optical functions on the above-described composite polarizing plate, and also has a thin and lightweight configuration and excellent durability and visibility. It becomes. These composite polarizing plates or laminated optical members provide an image display device that is thin and excellent in durability and visibility.

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

[Composite polarizing plate]
FIG. 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 this figure, a transparent protective layer 2 is disposed on one surface of a polarizer 1, and a retardation plate 5 is disposed on the other surface of the polarizer 1 via a first pressure-sensitive adhesive layer 6. And a second pressure-sensitive adhesive layer 7 is disposed outside the retardation plate 5 to form a composite polarizing plate 11. In general, a release film 9 that temporarily protects the surface of the second pressure-sensitive adhesive layer 7 positioned outside the retardation plate 5 is provided until it is bonded to an image display element or the like. A plurality of retardation plates 5 can be formed, but even in that case, the second pressure-sensitive adhesive layer 7 is disposed outside the retardation plate located on the side farthest from the polarizer 1.

And it exists between both including the 1st pressure sensitive adhesive layer 6 which joins the polarizer 1 and the phase difference plate 5, and the 2nd pressure sensitive adhesive layer 7 located in the outer side of the phase difference plate 5. At least the first pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer contains a light diffusing agent and exhibits a storage elastic modulus of 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. Consists of a light diffusive pressure sensitive adhesive layer. Since the storage elastic modulus usually decreases gradually as the temperature rises, if both the storage elastic modulus at 23 ° C. and 80 ° C. are within the above range, storage at a temperature in this range is 0.15 to 10 MPa. It can be seen that the elastic modulus is shown.

As shown in FIG. 1, when the retardation plate 5 is composed of one sheet, at least the first pressure- sensitive adhesive layer 6 among the first pressure- sensitive adhesive layer 6 and the second pressure-sensitive adhesive layer 7. The adhesive layer 6 is a light diffusable pressure sensitive adhesive layer containing a light diffusing agent as described above and having a storage elastic modulus of 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. I just need it. In this case, the first pressure-sensitive adhesive disposed on the surface opposite to the surface in contact with the transparent protective layer 2 of the polarizer 1 also from the viewpoint of obtaining a composite polarizing plate with the highest light diffusion efficiency and high visibility. A light diffusing agent is contained in the layer 6 and the pressure sensitive adhesive layer 6 exhibits a storage elastic modulus of 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. An agent layer is preferred. Furthermore, no foaming occurs in the adhesive layer even in a high temperature environment, and there is no luminance unevenness in the case of an image display device. From the viewpoint of obtaining a uniform brightness for a long time, the light diffusable pressure sensitive adhesive layer is The average particle size of the light diffusing agent in the layer is 0.1 to 20 μm, the storage elastic modulus at 23 ° C. of the layer is preferably 0.3 to 10 MPa, and the haze value is preferably 5% or more, storage modulus at 8 0 ° C. in addition also it is particularly preferable to 0.3 to 10 MPa. The first pressure-sensitive adhesive layer 6 is the light diffusive pressure-sensitive adhesive layer because the second pressure-sensitive adhesive layer 7 provided via the retardation plate 5 can be designed freely. preferable. That is, since the liquid crystal cell is expensive, there is a demand to peel off and reuse the liquid crystal cell when the composite polarizing plate is not adhered. In this case, if the first pressure-sensitive adhesive layer 6 is a composite polarizing plate having a light diffusive pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer 7 is a releasable pressure-sensitive adhesive layer. It is possible to achieve both the visibility and removability of the composite polarizing plate. In addition, since a thin image display device is desired, the glass surface of the liquid crystal cell may be ground to reduce the thickness, but in this case, the glass surface becomes rough. Even when affixed to such a roughened glass surface, the second pressure-sensitive adhesive layer 7 prevents the bleeding and blurring by the light diffusable pressure-sensitive adhesive layer of the first pressure-sensitive adhesive layer 6. Can be made a pressure-sensitive adhesive layer having high followability capable of embedding a rough surface .

  FIG. 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 figure, a first retardation plate 4 and a second retardation plate 5 are used, and both retardation plates are laminated via a third pressure-sensitive adhesive layer 8. That is, in this example, the transparent protective layer 2 is disposed on one side of the polarizer 1, and the first retardation plate 4 is laminated on the other side of the polarizer 1 via the first pressure-sensitive adhesive layer 6. The third pressure-sensitive adhesive layer 8 and the second retardation plate 5 are sequentially laminated on the outside, and the second pressure-sensitive adhesive layer 7 is disposed outside the second retardation plate 5; The composite polarizing plate 12 is used. Even when three or more retardation plates are laminated, each retardation plate is preferably bonded via a pressure-sensitive adhesive layer. A release film 9 is usually provided on the outside of the second pressure-sensitive adhesive layer 7 located outside the second retardation plate 5 to temporarily protect the surface until it is attached to an image display element or the like. Is the same as the example shown in FIG.

In the form shown in FIG. 2, the first pressure-sensitive adhesive layer 6 that joins the polarizer 1 and the first retardation plate 4, and the second pressure-sensitive adhesive located outside the second retardation plate 5. Of the layer 7 and the third pressure-sensitive adhesive layer 8 that joins the first retardation plate 4 and the second retardation plate 5, at least the first pressure-sensitive adhesive layer 6 includes a light diffusing agent. And a light diffusible pressure-sensitive adhesive layer containing 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. In this case, the transparent protective layer 2, the polarizer 1, the first pressure-sensitive adhesive layer 6, the retardation plate 4 and the third layer are sequentially arranged from the viewpoint of increasing the light diffusion efficiency and obtaining a composite polarizing plate having good visibility. the pressure sensitive adhesive layer 8 of the phase difference plate 5, the second pressure sensitive adhesive layer 7, the double focus polarizing plate laminated with the release film 9, the first pressure sensitive adhesive layer 6 a light diffusing agent It is preferable that the pressure-sensitive adhesive layer be a light-diffusible pressure-sensitive adhesive layer having a storage elastic modulus of 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. Furthermore, no foaming occurs in the adhesive layer even in a high temperature environment, and there is no luminance unevenness in the case of an image display device. From the viewpoint of obtaining a uniform brightness for a long time, the light diffusable pressure sensitive adhesive layer is The average particle size of the light diffusing agent in the layer is 0.1 to 20 μm, the storage elastic modulus at 23 ° C. of the layer is preferably 0.3 to 10 MPa, and the haze value is preferably 5% or more, storage elastic modulus at 80 ° C. in addition also it is particularly preferable to 0.3 to 10 MPa. Moreover, it is preferable to use the first pressure-sensitive adhesive layer 6 as the light diffusive pressure-sensitive adhesive layer because the second pressure-sensitive adhesive layer 7 to be bonded to a liquid crystal cell or the like can be freely designed. That is, since the liquid crystal cell is expensive, there is a demand to peel off and reuse the liquid crystal cell when the composite polarizing plate is not adhered. In this case, if the first pressure-sensitive adhesive layer 6 is a composite polarizing plate having a light diffusive pressure-sensitive adhesive layer, the second pressure-sensitive adhesive layer 7 is a releasable pressure-sensitive adhesive layer. It is possible to achieve both the visibility and removability of the composite polarizing plate. In addition, since a thin image display device is desired, the glass surface of the liquid crystal cell may be ground to reduce the thickness, but in this case, the glass surface becomes rough. Even when affixed to such a roughened glass surface, the second pressure-sensitive adhesive layer 7 prevents the bleeding and blurring by the light diffusable pressure-sensitive adhesive layer of the first pressure-sensitive adhesive layer 6. Can be made a pressure-sensitive adhesive layer having high followability capable of embedding a rough surface .

As described above, in the present invention, the first pressure-sensitive adhesive layer 6 disposed on one surface of the polarizer 1 and bonded to the phase difference plate 5 or 4 and the farthest side from the polarizer 1 are positioned. including the second pressure sensitive adhesive layer 7 that is disposed outside the retardation plate 5, at least a first pressure sensitive adhesive layer 6 of the pressure-sensitive adhesive layer present between the two person, A light diffusing agent is contained. By arranging a pressure-sensitive adhesive containing a light diffusing agent, brightness is ensured when the image display device to which the composite polarizing plate is applied is viewed from the front and obliquely, and the display image Bleeding and blurring are less likely to occur. The pressure-sensitive adhesive layer containing the light diffusing agent has a relatively high storage elastic modulus of 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. It consists of layers. Thereby, durability can be enhanced when the composite polarizing plate or an image display device to which the composite polarizing plate is applied is exposed to a high temperature environment or a high temperature environment and a low temperature environment are repeated. In addition, the composite polarizing plate having the light diffusive pressure-sensitive adhesive layer exhibits good durability when bonded, and does not cause foaming in the adhesive layer even in a high temperature environment. From the viewpoint that the image display device obtained using the polarizing plate has no luminance unevenness and can obtain uniform brightness for a long time, the light diffusive pressure-sensitive adhesive layer has an average particle size of the light diffusing agent in the layer. assume the diameter 0.1 to 20 [mu] m, and 0.3~10MPa a storage modulus at 23 ° C., and preferably to the layer of the haze value is 5% or more, our Keru storage modulus to 80 ° C. in addition it is particularly preferred that also a 0.3 to 10 MPa.

In this invention, as shown in FIG.1 and FIG.2, the 1st pressure sensitive adhesive layer 6 is arrange | positioned directly on one surface of the polarizer 1, and the phase difference plate 5 or 4 is bonded together there. Therefore, compared with the conventional polarizing plate in which the transparent protective layer is stuck on both surfaces of the polarizer, the force for suppressing the expansion and contraction of the polarizer 1 when exposed to a high temperature environment is small. Accordingly, the first pressure sensitive adhesive layer 6 for bonding the polarizer 1 and the phase difference plate 5 or 4, the storage modulus of its is, 0.3 to 10 MPa at 23 ° C., preferably at 8 0 ° C. 0. A value between 15 and 10 MPa is taken . Although the pressure sensitive adhesive layer 6 is of a light diffusing pressure-sensitive adhesive layer, the layer of light diffusing agent and the average particle diameter of 0.1 to 20 [mu] m, 0.3 to 10 MPa and a storage elastic modulus at 23 ° C. and then, and it is preferable to the layer of haze value is 5% or more, the storage elastic modulus at 80 ° C. in addition also it is particularly preferable to 0.3 to 10 MPa. In this way, the first pressure-sensitive adhesive layer 6 that joins the polarizer 1 and the retardation plate 5 or 4 is made of a material having a high storage elastic modulus, so that a composite polarizing plate or an image display using the composite polarizing plate is applied. When the apparatus is exposed to a high temperature, or when a high temperature environment and a low temperature environment are repeated, a dimensional change accompanying expansion and contraction of the polarizer 1 can be suppressed.

  Hereinafter, each member which comprises the composite polarizing plate of this invention is demonstrated.

[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 resin constituting the polarizer 1 can be obtained by saponifying a polyvinyl acetate resin. Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable therewith. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group. The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. This polyvinyl alcohol-based resin may be further modified, and for example, polyvinyl formal and polyvinyl acetal modified with aldehydes may be used. Moreover, the polymerization degree of polyvinyl alcohol-type resin is about 1,000-10,000 normally, Preferably it is about 1,500-5,000.

  A film obtained by forming such a polyvinyl alcohol-based resin is used as an original film of the polarizer 1. The method for forming a polyvinyl alcohol-based resin is not particularly limited, and can be formed by a known method. Although the film thickness of the raw film which consists of polyvinyl alcohol-type resin is not specifically limited, For example, it is about 1 micrometer-150 micrometers. Considering easiness of stretching, the film thickness is preferably 10 μm or more.

  The polarizer 1 has a step of uniaxially stretching such a polyvinyl alcohol resin film, a step of dyeing the polyvinyl alcohol resin film with a dichroic dye and adsorbing the dichroic dye, and a dichroic dye being adsorbed. It is manufactured through a step of treating the polyvinyl alcohol-based resin film with a boric acid aqueous solution and a step of washing with water after the treatment with the boric acid aqueous solution. As the dichroic dye, iodine or a dichroic organic dye is used.

[Transparent protective layer]
A transparent protective layer 2 is disposed on one side of the polarizer 1. An appropriate resin film can 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 resin films such as triacetyl cellulose and diacetyl cellulose, polyester resin films such as polyethylene terephthalate, polyethylene isophthalate and polybutylene terephthalate, poly [methyl (meth) acrylate] and poly [ethyl (meth) acrylate] Acrylic resin film, polycarbonate resin film, polyethersulfone resin film, polysulfone resin film, polyimide resin film, polyolefin resin film, cyclic olefin resin film using cyclic olefin as a monomer such as norbornene, etc. be able to. An adhesive or a pressure-sensitive adhesive can be used for bonding the polarizer 1 and the transparent protective layer 2.

  A surface treatment layer such as a hard coat layer, an antireflection layer, or an antiglare layer may be provided on the surface of the transparent protective layer 2 as necessary. The hard coat layer is formed to prevent scratches on the surface of the polarizing plate. The hard coat layer is mainly composed of an ultraviolet curable resin, for example, an acrylic resin or a silicone resin, and the adhesiveness to the transparent protective layer 2. Those having excellent hardness are appropriately selected and can be formed on the surface of the transparent protective layer 2. 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 to prevent disturbance of visibility caused by external light reflected on the surface of the polarizing plate, for example, a roughening method such as a sandblasting method or an embossing method, In general, the surface of the transparent protective layer 4 is formed to have a concavo-convex structure by a method of applying and curing a coating liquid in which transparent fine particles are mixed with an ultraviolet curable resin.

[Phase difference 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 can be composed of various transparent resin films similar to those exemplified as the resin constituting the transparent protective layer 2, and in particular, characteristics required as a retardation plate, that is, Those whose birefringence is optically uniform are preferably selected and used for the purpose of protecting the polarizer 1 and compensating for the phase difference by the liquid crystal cell (including the meaning of viewing angle compensation). For example, those conventionally used in image display devices can be used without limitation, birefringent films composed of stretched films of various transparent resins, films in which discotic liquid crystals and nematic liquid crystals are oriented and fixed, Examples include those in which such a liquid crystal layer is formed on a base film. When the liquid crystal layer is fixed on the base film, a cellulose resin film such as triacetyl cellulose is preferably used as the base film for supporting the oriented liquid crystal layer.

  As a resin for forming a birefringent film, for example, polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polyolefin such as polypropylene, polyarylate, polyamide, or cyclic olefin such as norbornene is used as a monomer. Examples include cyclic polyolefins. The stretched film may be processed by an appropriate method such as uniaxial or biaxial. Moreover, the birefringent film which controlled the refractive index of the thickness direction of a film by applying shrinkage force and / or extending | stretching force under adhesion | attachment with a heat-shrinkable film can also be used.

  As the retardation plate, a wave plate (λ / 2 plate or λ / 4 plate) capable of forming an elliptically polarized light or a circularly polarized light mode composite polarizing plate used in an image display device for mobile use is used effectively. The elliptically polarized light or circularly polarized light mode composite polarizing plate has a function of changing to elliptically polarized light or circularly polarized light when the incident polarized light is linearly polarized light, and changing to linearly polarized light when the incident polarized light is elliptically polarized light or circularly polarized light. . In particular, as a retardation plate capable of changing elliptically polarized light or circularly polarized light into linearly polarized light and linearly polarized light into elliptically polarized light or circularly polarized light, λ gives an in-plane phase difference of ¼ wavelength with respect to a wavelength λ of visible light. A so-called / 4 plate is used. Further, the λ / 2 plate that gives an in-plane phase difference of ½ wavelength with respect to a wavelength λ of visible light has a function of rotating the direction of linearly polarized light. As the λ / 4 plate, for example, a plate having an in-plane retardation of about 90 to 160 nm can be used. As the λ / 2 plate, for example, a plate having an in-plane retardation of about 200 to 300 nm can be used.

  Further, the elliptically polarizing mode composite polarizing plate is effective for preventing a coloring phenomenon caused by liquid crystal birefringence in a liquid crystal display device. The circular polarizing mode composite polarizing plate is reflective or semi-transmissive. It is effectively used for the purpose of improving luminance in a reflective image display device. The circular polarization mode composite polarizing plate also has an antireflection function.

  As shown in FIG. 1, when a single retardation plate is used, a λ / 4 plate can be used as a suitable retardation plate 5. In this case, the polarizer 1 and the λ / 4 plate 5 are laminated such that the slow axis of the latter is about 45 ° or about 135 ° with respect to the former polarization transmission axis. Functions as a circularly polarizing plate.

  As shown in FIG. 2, when two retardation plates are used, as a suitable combination of retardation plates, the first retardation plate 4 disposed on the polarizer 1 side is a λ / 2 plate. The second retardation plate 5 disposed on the side far from the polarizer 1 is a λ / 4 plate. In this case, for example, the slow axis of the λ / 2 plate 4 that is the first retardation plate is about 15 ° with respect to the polarization transmission axis of the polarizer 1, and λ / 4 that is the second retardation plate. The slow axis of the plate 5 is about 75 °, or the slow axis of the λ / 2 plate 4 which is the first retardation plate is about 75 ° and the second retardation plate λ / By disposing the four plates 5 so that the slow axis is about 195 °, the composite polarizing plate 12 functions as a circular polarizing plate over a wide wavelength range.

[Pressure sensitive adhesive layer]
A first pressure-sensitive adhesive layer 6 that joins the polarizer 1 and the phase difference plate 5 or 4, and a second pressure-sensitive adhesive disposed outside the phase difference plate 5 that is located farthest from the polarizer. The layer 7 and the third pressure-sensitive adhesive layer 8 to be joined when two or more retardation plates are used are composed of an adhesive material having an adhesive base polymer (also referred to as an adhesive resin). it can, at least a first pressure sensitive adhesive layer 6 of these pressure-sensitive adhesive layer, adhesive resin and a light diffusing pressure-sensitive adhesive layer formed by the adhesive material containing a light diffusing agent It is. A layer made of an adhesive material (hereinafter sometimes referred to as an adhesive material layer) may form a pressure-sensitive adhesive layer as it is, or heat, ultraviolet rays, electron beams, etc. If the form of the energy ray-sensitive adhesive layer by indicia pressure also.
Specific examples of the adhesive base polymer (adhesive resin) include acrylic, rubber-based, urethane-based, silicone-based, and polyvinyl ether-based base polymers. Moreover, an energy beam curing type, a thermosetting type, etc. may be sufficient. Among these, transparency, weather resistance, and is suitably tacky resin as a base polymer an acrylic resin excellent in heat resistance, as the adhesive resin in the present invention, (A) an acrylic copolymer and (B) Ru used as composed of the active energy ray-curable compound. Examples of (A) acrylic copolymers include (meth) acrylic ester copolymers. Here, (meth) acrylic acid means both acrylic acid and methacrylic acid, and other similar terms are the same.

  As the (meth) acrylic acid ester-based copolymer, those having a crosslinking point that can be crosslinked by various crosslinking methods are preferably used. There is no particular limitation on the (meth) acrylic acid ester-based copolymer having such a crosslinking point, and any (meth) acrylic acid ester-based copolymer conventionally used as a resin component of an adhesive can be arbitrarily selected. Can be selected and used.

  As a (meth) acrylic acid ester-based copolymer having such a crosslinking point, a (meth) acrylic acid ester having an alkyl group of 1 to 20 carbon atoms and a crosslinkable functional group in the molecule. Preferable examples include copolymers of monomers and other monomers used as desired. Here, examples of the (meth) acrylic acid ester having 1 to 20 carbon atoms of the alkyl group in the ester portion include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth ) Butyl acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, decyl (meth) acrylate, ( Examples include dodecyl (meth) acrylate, myristyl (meth) acrylate, palmityl (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 a hydroxyl group, a carboxyl group, an amino group, and an amide group as a functional group. As a specific example, (meth) acrylic acid 2 -Hydroxyethyl, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, (meth) acrylic acid 4 -(Meth) acrylic acid hydroxyalkyl esters such as hydroxybutyl; acrylamides such as (meth) acrylamide, N-methyl (meth) acrylamide, N-methylol (meth) acrylamide; monomethylaminoethyl (meth) acrylate, (meth ) Monoethylaminoethyl acrylate, (meth) acrylic acid (Meth) acrylic acid monoalkylamino esters such as nomethylaminopropyl and (meth) acrylic acid monoethylaminopropyl; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid and citraconic acid An acid etc. are mentioned. These monomers may be used independently and may be used in combination of 2 or more type.

  In the adhesive resin, the (meth) acrylic acid ester copolymer used as the component (A) is not particularly limited with respect to the copolymerization form, and may be any of random, block, and graft copolymers. Good. As the molecular weight, those having a weight average molecular weight of 500,000 or more are usually used. When the weight average molecular weight is 500,000 or more, adhesion to the adherend and adhesion durability are sufficient, and neither floating nor peeling occurs. In view of adhesion and adhesion durability, the weight average molecular weight is preferably 600,000 to 2,200,000, particularly preferably 700,000 to 2,000,000. In addition, the said weight average molecular weight is the value of polystyrene conversion measured by the gel permeation chromatography (GPC) method.

  Furthermore, in this (meth) acrylic acid ester 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 mass. When the content is 0.01% by mass or more, crosslinking is sufficient due to a reaction with a crosslinking agent described later, and durability is improved. On the other hand, when the content is 10% by mass or less, the degree of cross-linking becomes too high, and the suitability for bonding to a liquid crystal glass cell or a retardation plate is not deteriorated. Considering durability and suitability for bonding to a liquid crystal glass cell or a retardation plate, the more preferable content of the monomer unit having this crosslinkable functional group is 0.05 to 7.0% by mass, The range of 0.2-6.0 mass% is preferable. In the present invention, the (meth) acrylic acid ester copolymer of the component (A) may be used alone or in combination of two or more.

In the adhesive resin, as the active energy ray-curable compound used as the component (B), a polyfunctional (meth) acrylate monomer having a molecular weight of less than 1000 can be preferably exemplified.
Examples of the polyfunctional (meth) acrylate monomer having a molecular weight of less than 1000 include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, Polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dicyclopentanyl di (meth) acrylate, caprolactone modified dicyclopentenyl di (meth) acrylate , Ethylene oxide modified di (meth) acrylate phosphate, di (acryloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate, dimethylol dicyclopentane di (meth) a Lilate, ethylene oxide modified hydrophthalic acid di (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, adamantane di (meth) acrylate, 9,9-bis [4 Bifunctional type such as-(2-acryloyloxyethoxy) phenyl] fluorene; trimethylolpropane tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, propionic acid modified dipentaerythritol tri (meth) acrylate, pentaerythritol tri Trifunctional type such as (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, tris (acryloxyethyl) isocyanurate; Tetrafunctional type such as tetra (meth) acrylate and pentaerythritol tetra (meth) acrylate; pentafunctional type such as propionic acid modified dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate and caprolactone modified dipentaerythritol Examples include hexafunctional types such as hexa (meth) acrylate.

  In the present invention, these polyfunctional (meth) acrylate monomers may be used alone or in combination of two or more. Among these, a cyclic structure is added to the skeleton structure. It is preferable to contain what it has. The cyclic structure may be a carbocyclic structure or a heterocyclic structure, and may be 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, tris (acryloxyethyl) isocyanurate, dimethylol dicyclopentane diacrylate, ethylene Oxide-modified hexahydrophthalic acid diacrylate, tricyclodecane dimethanol acrylate, neopentyl glycol-modified trimethylolpropane diacrylate, adamantane diacrylate, and the like are suitable.

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

Here, examples of the polyester acrylate oligomer include esterification of hydroxyl groups of a polyester oligomer having hydroxyl groups at both ends obtained by condensation of polyvalent carboxylic acid and polyhydric alcohol with (meth) acrylic acid, It can be obtained by esterifying the terminal hydroxyl group of an oligomer obtained by adding alkylene oxide to a monovalent carboxylic acid 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 and esterifying it. A carboxyl-modified epoxy acrylate oligomer obtained by partially modifying this epoxy acrylate oligomer with a dibasic carboxylic acid anhydride can also be used. The urethane acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by the reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid. It can be obtained by esterifying the hydroxyl group of ether polyol with (meth) acrylic acid.
The weight average molecular weight of the acrylate oligomer is a value in terms of standard polystyrene measured by GPC method, preferably 50,000 or less, more preferably 500 to 50,000, and still more preferably 3,000 to 40,000. Is selected. These acrylate oligomers may be used alone or in combination of two or more.

In the present invention, an adduct acrylate polymer in which a group having a (meth) acryloyl group is introduced into the side chain can also be used as the component (B). Such an adduct acrylate-based polymer includes the (meth) acrylic acid ester described in the above-mentioned (meth) acrylic acid ester-based copolymer of the component (A), a monomer having a crosslinkable functional group in the molecule, And a compound having a (meth) acryloyl group and a group capable of reacting with a crosslinkable functional group is allowed to react with a part of the crosslinkable functional group of the copolymer. 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 above polyfunctional acrylate monomers, acrylate oligomers and adduct acrylate polymers, or two or more types may be used in combination. Good.

  In the present invention, the content ratio of the acrylic copolymer of the component (A) and the active energy ray-curable compound of the component (B) is a mass ratio from the aspect of the performance of the pressure-sensitive adhesive layer to be obtained. The ratio is preferably 100: 1 to 100: 100, more preferably 100: 5 to 100: 50, and still more preferably 100: 10 to 100: 40.

[Light diffusing agent]
The light diffusing agent contained in the light diffusive pressure-sensitive adhesive layer may be fine particles having a refractive index different from that of the pressure-sensitive adhesive resin constituting the pressure-sensitive adhesive layer. The light diffusing agent may be fine particles made of inorganic compounds or organic compounds (polymers). Fine particles can be used. The difference in refractive index between the adhesive 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 when an image display device is used. Considering this, since the refractive index of the adhesive resin is usually around 1.4, the following can be preferably cited as fine particles comprising an inorganic compound or an organic compound used as a light diffusing agent.

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

  Examples of the fine particles comprising an organic compound include melamine beads (refractive index 1.57), polymethyl methacrylate beads (refractive index 1.49), methyl methacrylate / styrene copolymer resin beads (refractive index 1.50). 1.59), polycarbonate beads (refractive index 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), silicone resin beads (refractive index 1.46), and the like.

  Furthermore, when an acrylic copolymer is selected as the component (A) of the adhesive resin, the epoxy resin beads, polymethyl methacrylate beads, and silicone resin beads are excellent in dispersibility with respect to the acrylic copolymer, and are uniform and good. Since light diffusibility is obtained, it is preferable as a light diffusing agent. In addition, the light diffusing agent is preferably a spherical and monodispersed material with uniform light diffusion.

  The average particle diameter of the light diffusing agent is in the range of 0.1 to 20 μm. When the average particle size is less than 0.1 μm, the light diffusibility when the light diffusible pressure-sensitive adhesive layer is used is lowered, and when applied to an image display device, there is no luminance unevenness and uniform brightness is obtained. The effect of the present invention cannot be achieved. On the other hand, if the average particle size exceeds 20 μm, the contrast of the image is adversely affected, and if it is larger than the image pitch of the display, glare occurs. From the above points, the average particle diameter of the light diffusing agent is preferably in the range of 0.5 to 10 μm, particularly preferably in the range of 1 to 7 μm. Here, the average particle diameter of the light diffusing agent is a value measured by a centrifugal sedimentation light transmission method.

  The amount of the light diffusing agent is appropriately determined in consideration of the haze value required for the light diffusable pressure-sensitive adhesive layer in which it is blended, the brightness of the image display device to which it is applied, and the like. Generally, the range of 1 to 40% by mass is preferable with respect to the adhesive resin constituting the pressure-sensitive adhesive layer, and the range of 3 to 30% by mass is more preferable. When the content is 1% by mass or more, the effect of the present invention can be achieved without uneven brightness and uniform brightness. On the other hand, when the content of fine particles is 40% by mass or less, The adhesive force to the adherend is not reduced more than necessary.

  Moreover, the adhesive material of this invention can be made to contain a crosslinking agent as (C) component depending on necessity. There is no restriction | limiting in particular as this crosslinking agent, Arbitrary things can be suitably selected and used from what was conventionally used as a crosslinking agent in acrylic adhesive resin conventionally. Examples of such crosslinking agents include polyisocyanate compounds, epoxy resins, melamine resins, urea resins, dialdehydes, methylol polymers, aziridine compounds, metal chelate compounds, metal alkoxides, and metal salts. A compound is preferably used.

  Here, examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, alicyclic polyisocyanates such as isophorone diisocyanate, and hydrogenated diphenylmethane diisocyanate. And their biurets, isocyanurates, and adducts that are reaction products with low-molecular active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylol propane, castor oil, etc. Can do.

  In this invention, this crosslinking agent may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, although the usage-amount is based also on the kind of crosslinking agent, it is 0.01-20 mass parts normally with respect to 100 mass parts of acrylic copolymers of the said (A) component, Preferably, it is 0.1-10. Part by mass.

  Furthermore, the adhesive material of the present invention can contain a silane coupling agent as component (D), if desired. By including this silane coupling agent, for example, when bonding to a liquid crystal glass cell or the like, the adhesion between the pressure-sensitive adhesive layer and the glass cell becomes better. The silane coupling agent is an organosilicon compound having at least one alkoxysilyl group in the molecule, has good compatibility with the pressure-sensitive adhesive component, and has light transparency, for example, substantially transparent. Those are preferred. The addition amount of such a silane coupling agent is preferably in the range of 0.001 to 10 parts by mass, particularly 0.005 to 5 parts by mass with respect to 100 parts by mass of the acrylic copolymer of the component (A). A range is preferred.

  Specific examples of the silane coupling agent include a polymerizable unsaturated group-containing silicon compound such as vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, Silicon compounds having an epoxy structure such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- Examples include amino group-containing silicon compounds such as (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, and 3-chloropropyltrimethoxysilane. These may be used individually by 1 type and may be used in combination of 2 or more type.

  In the adhesive material of the present invention, various additives usually used for acrylic adhesive resins as desired, for example, tackifiers, antioxidants, ultraviolet absorbers, as long as the object of the present invention is not impaired. , Light stabilizers, softeners and the like can be added.

The light diffusive pressure-sensitive adhesive layer of the present invention is preferably formed by irradiating an adhesive material containing the component (B) as an adhesive resin with active energy rays. By performing crosslinking using active energy rays, the entire pressure-sensitive adhesive layer can be crosslinked instantaneously and uniformly without distortion, and it is also preferable for obtaining the storage elastic modulus of the present invention. .
Examples of the active energy rays include ultraviolet rays and electron beams. The ultraviolet rays are obtained with a high-pressure mercury lamp, an electrodeless lamp, a xenon lamp or the like, while the electron beam is obtained with an electron beam accelerator or the like. Among these active energy rays, ultraviolet rays are particularly preferable. In addition, when using an electron beam, a light diffusable pressure sensitive adhesive can be formed, without adding a photoinitiator.
The irradiation amount of the active energy ray for the adhesive material is appropriately selected so as to obtain an adhesive having a storage elastic modulus, which will be described in detail later, and an adhesive force to an alkali-free glass. In the case of -1000mW / cm < ² >, the light quantity 50-1000mJ / cm < ² >, and an electron beam, the range of 10-1000krad is preferable.

  The light diffusive pressure-sensitive adhesive layer containing the light diffusing agent ensures the brightness of the image display device to which the composite polarizing plate is applied, and has a haze from the viewpoint of preventing the display image from blurring or blurring. The value is preferably 5% or more, more preferably in the range of 20 to 90%, still more preferably 30 to 75%. The haze value is a value defined by JIS K7105 and represented by (diffuse transmittance / total light transmittance) × 100 (%).

  In the present invention, the light diffusable pressure-sensitive adhesive layer preferably has a gel fraction of 60% or more. That is, when there are few low molecular weight components that can be extracted with an organic solvent, light that floats or peels off under heating or in an environment of heat, causes little contamination to the adherend, and has a gel fraction of 60% or more. The diffusible pressure sensitive adhesive layer has high durability and stability. The gel fraction is further preferably 85% or more, and particularly preferably 90 to 99.9%. In the present invention, an image display device produced by, for example, adhering to a liquid crystal glass cell using a composite polarizing plate having such a light diffusible pressure-sensitive adhesive layer causes light leakage even in a high temperature and high humidity environment. In addition to being difficult, blurring and blurring of the display image are extremely suppressed. The method for measuring the gel fraction will be described in detail later.

The light diffusive pressure-sensitive adhesive layer used in the present invention preferably has an adhesive strength against an alkali-free glass of 0.2 N / 25 mm or more. If this adhesive strength 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 strength. A more preferable adhesive force is 1.0 to 50 N / 25 mm.
Moreover, it is preferable that the adhesive force with respect to a polycarbonate is 5 N / 25mm or more. If this adhesive strength is 5 N / 25 mm or more, for example, the polarizing plate can be bonded to the retardation plate with sufficient adhesive strength. The method for measuring the adhesive strength will be described in detail later.

  The light diffusive pressure-sensitive adhesive layer used in the present invention preferably has a holding power at 80 ° C. of 200 μm or less in terms of a deviation after 70000 seconds. If this deviation | shift amount is 200 micrometers or less, when optical functional films, such as a polarizing plate, are bonded to a liquid crystal glass cell, a favorable bonding state can be hold | maintained over a long period of time. This deviation amount is more preferably 100 μm or less. The method for measuring the deviation (holding force) will be described in detail later.

  Although the thickness of the light diffusable pressure-sensitive adhesive layer in which the light diffusing agent is blended is determined according to the adhesive force and the like, it is usually in the range of 1 to 40 μm. In order to obtain a thin composite polarizing plate that is an object of the present invention, it is desirable to apply a thin coating within a range that does not impair properties such as workability and durability. Therefore, the thickness of the light diffusable pressure-sensitive adhesive layer is 3 to 25 μm, which maintains good workability and exhibits high durability, and when the image display device is viewed from the front or obliquely. This is preferable from the viewpoint of maintaining brightness and making it difficult for bleeding and blurring of the display image to occur.

[Storage modulus of light diffusive pressure-sensitive adhesive layer]
In the present invention, the light diffusible pressure-sensitive adhesive layer containing the light diffusing agent has a storage elastic modulus of 0.3 to 10 MPa at 23 ° C., preferably 0.15 to 10 MPa at 80 ° C. . Good Mashiku is to indicate storage modulus 0.4~3MPa at 23 ° C. and 80 ° C.. The storage elastic modulus of the pressure-sensitive adhesive layer is a value measured according to JIS K7244. The pressure-sensitive adhesive layer used in a normal image display device or an optical film therefor has a storage elastic modulus of at most about 0.1 MPa at 23 ° C. Compared with that, the pressure-sensitive adhesive layer defined in the present invention. storage modulus adhesive layer, 0.15～10MPa is a high value at 23 ° C. 0.3 to 10 MPa, also at 80 ° C.. By using such a high storage elastic modulus, that is, a hard pressure-sensitive adhesive layer, it is possible to compensate for a lack of cohesive force when placed in a high temperature environment or when a high temperature environment and a low temperature environment are repeated, It is possible to suppress a dimensional change accompanying the contraction of the polarizer that occurs at that time. That is, good durability can be obtained. Furthermore, when the storage elastic modulus at 23 ° C. is 10 MPa or less, it is preferable in the present invention from the viewpoint of adhesive strength.

In the present invention, the storage elastic modulus of the light diffusable pressure-sensitive adhesive layer containing the light diffusing agent is kept high as described above. In order to obtain such a high storage elastic modulus, a base adhesive resin May be configured with such a high storage elastic modulus. In order to make the storage elastic modulus of the light diffusable pressure-sensitive adhesive layer such a high value, in the present invention, the adhesive resin is composed of (A) an acrylic copolymer and (B) an active energy ray-curable compound. adopted things, a light diffusing agent to the adhesive material dispersed therein, by Rukoto then cured by irradiation with energy ray, and to exhibit a high storage modulus.

The first pressure-sensitive adhesive layer 6 that joins the polarizer 1 and the phase difference plate 5 or 4 contains a light diffusing agent and is 0.3 to 10 MPa at 23 ° C., preferably 0.15 at 80 ° C. It is comprised with what shows the storage elastic modulus of 10 Mpa . When other pressure-sensitive adhesive layers have such a high storage elastic modulus without a light diffusing agent, the same method as described above can be used.

[Formation of pressure-sensitive adhesive layer and preparation of composite polarizing plate]
The method for forming the pressure-sensitive adhesive layer or the light diffusive pressure-sensitive adhesive layer on the surface of the polarizer 1 or the surface of the phase difference plate 5 or 4 is not particularly limited. For example, an organic solvent such as toluene or ethyl acetate is used. After the adhesive material is dissolved or dispersed to prepare a 10 to 40% by weight solution, this is directly applied to the surface of the polarizer or retardation plate on which the pressure-sensitive adhesive layer is to be formed and dried. , A method of laminating a release film made of a resin film treated with a release agent such as a silicone type, or after forming a pressure-sensitive adhesive layer on the release film as described above, and then applying it to a polarizer or a retardation plate A transfer method or the like can be employed. Moreover, when forming a pressure sensitive adhesive layer on the surface of a polarizer or a phase difference plate, if necessary, the pressure sensitive adhesive layer forming surface of the polarizer or the phase difference plate, and the pressure sensitive adhesive layer polarizer Alternatively, one or both of the surfaces to be bonded to the retardation plate may be subjected to a treatment for improving adhesion, such as a corona treatment.

  As shown in FIG. 1, a transparent protective layer 2 is disposed on one side of a polarizer 1, and only one retardation plate 5 is laminated on the other side of the polarizer 1 via a first pressure-sensitive adhesive layer 6. In addition, when 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 is A polarizing plate with a pressure-sensitive adhesive provided with one pressure-sensitive adhesive layer 6 is prepared, and a pressure-sensitive adhesive provided with a second pressure-sensitive adhesive layer 7 on one side of the retardation plate 5 It is advantageous to prepare a phase difference plate and laminate them so that the first pressure-sensitive adhesive layer 6 and the phase difference plate 5 overlap each other. In addition, for example, a phase difference 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 sides of the phase difference plate 5 is prepared. The polarizing plate having the transparent protective layer 2 bonded to one side of the polarizer 1 can be laminated so that the first pressure-sensitive adhesive layer 6 and the polarizer 1 overlap.

  As shown in FIG. 2, a transparent protective layer 2 is disposed on one surface of the polarizer 1, and the first retardation plate 4 is disposed on the other surface of the polarizer 1 via a first pressure-sensitive adhesive layer 6. When the third pressure-sensitive adhesive layer 8, the second retardation plate 5, and the second pressure-sensitive adhesive layer 7 are sequentially laminated, the transparent protective layer 2 is bonded to one side of the polarizer 1, A polarizing plate with a pressure sensitive adhesive provided with a first pressure sensitive adhesive layer 6 is prepared on the other surface of the polarizer 1, and a third pressure sensitive adhesive is attached to one surface of the first retardation plate 4. The first pressure-sensitive adhesive phase-difference plate provided with the adhesive layer 8 and the second pressure-sensitive adhesive provided with the second pressure-sensitive adhesive layer 7 on one side of the second retardation plate 5 A phase difference plate is prepared, and the first pressure sensitive adhesive layer 6 and the first phase difference plate 4 are sequentially overlapped with each other, and the third pressure sensitive adhesive layer 8 and the second phase difference are sequentially laminated. Laminate each so that the plates 5 overlap. Is an interest. In addition, for example, a polarizing plate with a pressure sensitive adhesive having a transparent protective layer 2 bonded to one side of the polarizer 1 and a first pressure sensitive adhesive layer 6 provided on the other side of the polarizer 1 is prepared. In addition, a phase difference plate with a double-sided pressure-sensitive adhesive in which a third pressure-sensitive adhesive layer 8 and a second pressure-sensitive adhesive layer 7 are respectively provided on both sides of the second retardation plate 5 is prepared. The first retardation plate 4 is sandwiched between the first pressure-sensitive adhesive layer 6 of the polarizing plate with pressure-sensitive adhesive and the third pressure-sensitive adhesive layer 8 of the retardation plate with double-sided pressure-sensitive adhesive. Arbitrary methods, such as laminating, can also be adopted.

  Thus, the method for laminating the polarizer and the retardation plate is not particularly limited, and it may be laminated by a conventionally known technique. For example, a laminating roll or the like is used to laminate so that the slow axis of the phase difference plate is orthogonal or parallel to the polarization transmission axis of the polarizer, or to the polarization transmission axis of the polarizer. A method of laminating so that the slow axis of the phase difference plate has a predetermined angle can be mentioned. In particular, the composite polarizing plate of the present invention is effectively used for laminating the polarizing transmission axis of the polarizer and the slow axis of the phase difference plate at a predetermined angle to obtain a circularly polarized or elliptically polarized mode.

[Laminated optical member]
The composite polarizing plate of the present invention can be used as a laminated optical member by laminating one or more optical layers exhibiting other optical functions when used. As examples of other optical layers, in addition to surface treatment layers such as the hard coat layer, antireflection layer, and antiglare layer previously exemplified as the layers that can be provided on the surface of the transparent protective layer 2, a reflective layer, transflective reflection Examples include a layer, a diffusion layer, a brightness enhancement film, and a light collector.

  The reflective composite polarizing plate is used in a liquid crystal display device of a type that reflects incident light from the viewing side and displays it. Since a light source such as a backlight can be omitted, the liquid crystal display device can be easily thinned. The transflective composite polarizing plate is used in a liquid crystal display device that displays as a reflective type in a bright place and as a transmissive type using a light source such as a backlight in a dark place. The reflective layer for making a reflective composite polarizing plate can be formed, for example, by attaching a foil or vapor deposition film made of a metal such as aluminum to the transparent protective layer 2 on the polarizer 1. The transflective layer for making a transflective composite polarizing plate is a method of using the reflective layer as a half mirror, or a reflective plate containing a pearl pigment or the like and exhibiting light transmittance, as a transparent protective layer. 2 and the like. On the other hand, the diffusion type composite polarizing plate has a function of diffusing incident light. For example, a method of performing a mat treatment on the transparent protective layer 2, a method of applying a resin containing fine particles, A light diffusing layer having a fine concavo-convex structure is formed on the surface using various methods such as a method of adhering a film.

  Further, the reflection / diffusion composite polarizing plate is obtained by providing a diffusion reflection layer by a method of providing a reflection layer reflecting the uneven structure on the fine uneven structure surface of the diffusion type composite polarizing plate, for example. The reflective layer having a fine concavo-convex structure has advantages such that incident light is diffused by irregular reflection, directivity and glare can be prevented, and unevenness in brightness and darkness can be suppressed. In addition, the resin layer or film containing fine particles has an advantage that incident light and its reflected light are diffused when passing through the layer, and brightness and darkness unevenness can be further suppressed. The reflective layer reflecting the surface fine concavo-convex structure can be formed, for example, by directly attaching a metal to the surface of the fine concavo-convex structure by a method such as vapor deposition such as vacuum deposition, ion plating, sputtering, or plating. Examples of the fine particles to be blended for forming the surface fine uneven structure include silica, aluminum oxide, titanium oxide, zirconium oxide, tin oxide, indium oxide, cadmium oxide, and oxide having an average particle diameter of 0.1 to 30 μm. Inorganic fine particles made of antimony or the like, organic fine particles made of a crosslinked or uncrosslinked polymer, or 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 remaining light for reuse, and is used for the purpose of improving brightness in a liquid crystal display device or the like. . Examples include a reflective linearly polarized light separation sheet, a cholesteric liquid crystal polymer alignment film designed to produce anisotropy in reflectance by laminating a plurality of thin film films having different refractive index anisotropies, and the like. Examples thereof include a reflective circularly polarized light separating sheet in which an alignment liquid crystal layer is supported on a base film.

  The light collector is used for the purpose of optical path control and can be formed as a prism array sheet, a lens array sheet, or a dot-attached sheet.

  A part of the various optical layers as described above can be directly provided on the surface of the transparent protective layer 2 by coating or vapor deposition. Moreover, the optical layer prepared in the form of a film can be integrated with the composite polarizing plate using an adhesive or a pressure sensitive adhesive. The adhesive or pressure sensitive adhesive used for that purpose is not particularly limited, and an appropriate one may be selected and used. It is preferable to use a pressure-sensitive adhesive from the viewpoint of easy bonding work and prevention of optical distortion. Examples of pressure sensitive adhesives include those made of base polymers such as acrylic, rubber, urethane, silicone, and polyvinyl ether. Specifically, the same materials as those exemplified above for the pressure-sensitive adhesive layers 6, 7, and 8 can be used. Above all, like a pressure-sensitive adhesive with an acrylic base polymer (adhesive resin), it has excellent optical transparency, retains appropriate wettability and cohesion, and is also adhesive to the substrate. It is preferable to select and use one that has excellent weather resistance and heat resistance and does not cause peeling problems such as floating and peeling under heating and humidification conditions.

[Image display device]
The composite polarizing plate or laminated optical member of the present invention can be combined with various image display elements to form an image display device. For example, it can be arranged on one or both sides of a liquid crystal cell to form a liquid crystal display device. The liquid crystal cell used is arbitrary. For example, a liquid crystal display using various liquid crystal cells such as an active matrix driving type typified by a thin film transistor type and a simple matrix driving type typified by a super twisted nematic type. A device can be formed. When providing the composite polarizing plate or laminated optical member of this invention on both sides of a liquid crystal cell, the same thing may be arrange | positioned on both surfaces, and a different thing may be arrange | positioned.

FIG. 3 is a schematic cross-sectional view showing an example in which the composite polarizing plate and the laminated optical member of the present invention are applied to a liquid crystal display device. In this example, the state in which the release film 9 is peeled off from the composite polarizing plate 11 shown in FIG. 1 is attached to one side (the upper side in the figure) of the liquid crystal cell 30 on the second pressure-sensitive adhesive layer 7 side. On the other side of the liquid crystal cell 30 (the lower side of the figure), the second pressure-sensitive adhesive layer 7 / retardation plate 5 / first pressure-sensitive adhesive layer 6 / polarizer 1 / transparent protective layer The laminated optical member 20 is laminated in the order of 2 (corresponding to the composite polarizing plate 11 shown in FIG. 1 in this state), and the other optical layer 18 is laminated on the outer side thereof. It is stuck on the agent layer 7 side. In the liquid crystal display device of this example, the upper side of the figure is the viewing side, and when the backlight is arranged, the backlight is provided on the lower side of the figure. The other optical layer 18 in this case can be a reflective layer, a transflective layer, a brightness enhancement film, a light collector, and the like. FIG. 3 shows an example in which the composite polarizing plate 11 shown in FIG. 1 is combined with the liquid crystal cell 30. However, when the composite polarizing plate 12 shown in FIG. It will be understood from the above description that the composite polarizing plate 11 in FIG. 2 may be replaced with the composite polarizing plate 12 shown in FIG.

  Furthermore, the composite polarizing plate of the present invention is also effectively used in a circular polarization mode or an elliptical polarization mode having an antireflection function in an image display device other than a liquid crystal display device, for example, a flat display such as an organic EL display device. 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 here.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, the retardation value is a value measured at a wavelength of 589 nm, and the storage elastic modulus, adhesive force, haze value, gel fraction, holding power, evaluation of composite polarizing plate, average particle diameter, and weight The average molecular weight was measured by the following method.

(1) Measuring method of storage elastic modulus The storage elastic modulus (G ') of the pressure-sensitive adhesive layer is a measuring instrument "DYNAMIC ANALYZER" manufactured by REOMETRIC using an 8 mmφ x 1 mm thick cylinder as a test piece in accordance with JIS K7244. Using RDA II ", it was obtained by a torsional shear method with a frequency of 1 Hz under conditions of 23 ° C and 80 ° C.
(2) Adhesive strength (adhesive strength for alkali-free glass and polycarbonate)
Two samples having a width of 25 mm and a length of 100 mm were cut out from the composite polarizing plate 13 and the release film 9 was peeled off (the thickness of the light diffusable pressure-sensitive adhesive layer was 25 μm). After affixing to a polycarbonate resin plate [“Pure Ace C110-100 (trade name)” manufactured by Teijin Kasei Co., Ltd.], pressure was applied in an autoclave manufactured by Kurihara Seisakusho at 0.5 MPa, 50 ° C. for 20 minutes. Then, after being left for 24 hours in an environment of 23 ° C. and a relative humidity of 50%, using the tensile tester (Orientec Tensilon) in the same environment, a peeling speed of 300 mm / min and a peeling angle of 180 ° The value measured in was used as the adhesive strength.
(3) Haze value The peelable film on the light diffusive pressure-sensitive adhesive layer (single) was peeled and removed, and in accordance with JIS K7105, an integrating sphere type light transmittance measuring device (“NDH-2000 made by Nippon Denshoku Industries Co., Ltd.) )), The diffuse transmittance (Hd%) and the total light transmittance (Ht%) were measured and calculated by the following formula.
Haze value (%) = Hd / Ht × 100
(4) Gel fraction The light diffusion pressure-sensitive adhesive layer (single) having a thickness of 25 μm was sampled to a size of 80 mm × 80 mm, and the release film was peeled and removed, and then wrapped in a polyester mesh (mesh size 200). The weight of only the diffusible pressure sensitive adhesive layer was weighed with a precision balance. The weight at this time is M1. The light diffusable pressure-sensitive adhesive layer was immersed in an ethyl acetate solvent using a Soxhlet (extractor), refluxed and treated for 16 hours. Thereafter, the light diffusive pressure-sensitive adhesive layer was taken out, air-dried in an environment of a temperature of 23 ° C. and a relative humidity of 50% for 24 hours, and further dried in an oven at 80 ° C. for 12 hours. The weight of only the light diffusable pressure-sensitive adhesive layer after drying was weighed with a precision balance. The weight at this time is M2. The value represented by (M2 / M1) × 100 (%) is taken as the gel fraction.
(5) Holding force A 25 mm wide and 150 mm long sample was cut out from the composite polarizing plate, peeled off the release film, and pasted so that 25 mm × 25 mm (area) was in contact with the test plate. Was reciprocated once at a speed of 300 mm / min, and the composite polarizing plate was pressure-bonded to the test plate. After that, it was left for 2 hours in an environment of 23 ° C. and 50% relative humidity, and after 70000 seconds in an environment of 80 ° C. under a load of 1000 g using a holding force measuring device described in JP-A-11-23449. The amount of deviation was measured. As a test plate, a SUS-304 steel plate having a thickness of 1.5 to 2.0 mm as defined in JIS-G-4305 is uniform in the length direction with No. 360 water-resistant abrasive paper as defined in JIS-R-6253. A polished one was used. Moreover, a digital indicator (“DEGIMATIC INDICATOR” manufactured by Mitutoyo Corporation) was used as a measurement sensor of the holding force measuring device.
(6) Evaluation of composite polarizing plate The composite polarizing plate was adjusted to a size of 233 mm × 309 mm with a cutting device (Super cutter “PN1-600” manufactured by Sugano Seiki Seisakusho Co., Ltd.), and then alkali-free glass [“1737” manufactured by Corning Co., Ltd. ] Was pressed under the conditions of 0.5 MPa, 50 ° C., and 20 minutes in an autoclave manufactured by Kurihara Seisakusho. Then, it put into the environment of each following durability conditions, and after 200 hours observed using a 10 magnification loupe, and evaluated durability with the following criteria.
A: On four sides, there is no defect in the region of 0.3 mm or more from the outer peripheral edge.
○: On the four sides, there is no defect in an area of 0.6 mm or more from the outer peripheral edge.
X: One of the four sides has an abnormal appearance defect of a composite polarizing plate of 0.1 mm or more such as floating, peeling, foaming, or streaking in an area of 0.6 mm or more from the outer peripheral edge.
<Durability conditions>
80 ℃, 90 ℃, 60 ℃, relative humidity 90% environment,
Heat shock test for 30 minutes each at −40 ° C. to 85 ° C., 50 cycles (7) Measurement of average particle diameter A sample consisting of 1.2 g of a light diffusing agent and 98.8 g of isopropyl alcohol was sufficiently stirred. And a centrifugal automatic particle size distribution measuring apparatus (“CAPA-700” manufactured by Horiba, Ltd.), and the measurement was performed by a centrifugal sedimentation light transmission method.
(8) Measurement of weight average molecular weight A weight average molecular weight is the polystyrene conversion value measured on condition of the following using gel permeation chromatography (GPC).
GPC measuring device: HLC-8020 manufactured by Tosoh Corporation
GPC column (passed in the following order): Tosoh Corporation TSK guard column HXL-H
TSK gel GMHXL (× 2)
TSK gel G2000HXL
Measuring 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 in which a urethane acrylate oligomer is blended with a copolymer of butyl acrylate and acrylic acid, and an isocyanate-based crosslinking agent is added, is subjected to a release treatment and has a thickness of 38 μm. A sheet-like pressure-sensitive adhesive formed on a release treatment surface of a polyethylene terephthalate film (release film) and dried to a thickness of 25 μm. The storage elastic modulus of the pressure-sensitive adhesive layer A was 0.41 MPa at 23 ° C. and 0.22 MPa at 80 ° C.

  Light diffusive pressure sensitive adhesive layer A: Thickness obtained by subjecting an organic solvent solution having the same composition as the pressure sensitive adhesive layer A to a mixture of silicone resin particles having an average particle size of 4.5 μm and a release treatment A sheet-like pressure-sensitive adhesive formed on a release treatment surface of a 38 μm polyethylene terephthalate film (release film) and dried to a thickness of 25 μm. The storage elastic modulus of the light diffusable pressure-sensitive adhesive layer A was 0.41 MPa at 23 ° C. and 0.22 MPa at 80 ° C. The haze value was 45%.

  Light diffusing agent-containing pressure-sensitive adhesive layer B: The light-diffusing pressure-sensitive adhesive layer A is blended on the release-treated surface of the 38 μm-thick polyethylene terephthalate film (release film) that has been subjected to the release treatment. A commercially available sheet-like pressure-sensitive adhesive in which an acrylic pressure-sensitive adhesive layer formed with a thickness of 25 μm is blended with the same silicone resin particles. No urethane acrylate oligomer is blended. The storage elastic modulus of light diffusing agent-containing pressure-sensitive adhesive layer (referring to a pressure-sensitive adhesive layer containing a light diffusing agent that does not satisfy the requirements of the present invention) is 0.05 MPa at 23 ° C. and 80 ° C. The pressure was 0.04 MPa. The haze value was 45%.

[Example 1] : Reference (a) Polarizing plate with pressure-sensitive adhesive layer From a triacetyl cellulose film having a thickness of 40 μm on one side of a polarizer having a thickness of 25 μm in which iodine is adsorbed and oriented on polyvinyl alcohol. A polarizing plate was prepared in which a transparent protective layer to be bonded was bonded through an epoxy adhesive. The above-mentioned pressure-sensitive adhesive layer A was bonded to the polarizer side, and a polarizing plate with a pressure-sensitive adhesive layer having a configuration of transparent protective layer / polarizer / pressure-sensitive adhesive layer A / release film was produced. .

(B) Retardation plate with pressure-sensitive adhesive layer Retardation plate composed of a stretched film of norbornene-based resin having a thickness of 40 μm and an in-plane retardation of 140 nm (“Essina film” manufactured by Sekisui Chemical Co., Ltd.) The light diffusable pressure-sensitive adhesive layer A was bonded to one side of (λ / 4 plate) to prepare a phase difference plate with a pressure-sensitive adhesive layer.

(C) Preparation of composite polarizing plate After peeling the release film from the polarizing plate with the pressure-sensitive adhesive layer prepared in (a) above, the pressure-sensitive adhesive prepared in (b) above was applied to the pressure-sensitive adhesive layer side. On the phase difference plate side of the phase difference plate with the agent layer (the side where the light diffusable pressure sensitive adhesive layer is not provided), the slow axis of the phase difference plate is 45 ° with respect to the polarization transmission axis of the polarizing plate. Thus, a composite polarizing plate was produced. 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 configuration.

  Transparent protective layer 2 / polarizer 1 / first pressure-sensitive adhesive layer 6 (25 μm) / retardation plate (λ / 4 plate) 5 / second pressure-sensitive adhesive layer 7a (light diffusable pressure-sensitive adhesive layer) 25 μm) / release film 9.

  In FIG. 4, the pressure-sensitive adhesive layer 6 and the λ / 4 plate 5 are separated from each other so that the stacking order can be understood. It will be understood from the explanation. In FIG. 5 and FIG. 6 below, the pressure-sensitive adhesive layer and the phase difference plate bonded thereto are separated from each other, but the same purpose as in FIG. 4 is obtained.

(D) Evaluation of Composite Polarizing Plate The release film 9 is peeled from the composite polarizing plate 13 obtained in (c) above, and the exposed light diffusable pressure-sensitive adhesive layer 7a is attached to a glass plate, 0.5 MPa, 50 The composite polarizing plate was adhered to the glass plate by an autoclave treatment at 20 ° C. for 20 minutes. In this state, a heat shock test was performed by placing in an atmosphere of −40 ° C. for 30 minutes, then moving to an atmosphere of + 85 ° C. and placing for 30 minutes as one cycle, and repeating this for 50 cycles. No defects were observed in the composite polarizing plate after the test, and a good state was maintained.

[Example 2] : Reference (a) Polarizing plate with pressure-sensitive adhesive layer In the same manner as in (a) of Example 1, the structure is transparent protective layer / polarizer / pressure-sensitive adhesive layer A / release film. A polarizing plate with a pressure sensitive adhesive layer was prepared.

(B) Retardation plate with pressure-sensitive adhesive layer Retardation plate composed of a stretched film of norbornene-based resin, having an in-plane retardation of 270 nm that is λ / 2 with respect to light wavelength λ, and a thickness of 33 μm Retardation plate with pressure sensitive adhesive layer (acrylic pressure sensitive adhesive having a thickness of 15 μm is laminated on one side of a plate (“ESCINA film” manufactured by Sekisui Chemical Co., Ltd.) (λ / 2 plate) (λ / 2 plate) was prepared. In addition, a retardation film made of a stretched film of norbornene-based resin, having an in-plane retardation of 90 nm that is λ / 4 with respect to the wavelength λ of light, and a thickness of 28 μm (manufactured by Sekisui Chemical Co., Ltd.) The light diffusive pressure-sensitive adhesive layer A was bonded to one side of an essina film “) (λ / 4 plate) to prepare a phase difference plate (λ / 4 plate) with a pressure-sensitive adhesive layer.

(C) Preparation of composite polarizing plate After peeling off the release film from the polarizing plate with the pressure-sensitive adhesive layer prepared in (a) above, the pressure-sensitive adhesive prepared in (b) above on the pressure-sensitive adhesive layer side. The λ / 2 plate side of the phase difference plate with the agent layer (λ / 2 plate) (the side where the pressure-sensitive adhesive layer is not provided) is the slow axis of the λ / 2 plate as the polarization transmission axis of the polarizing plate. The retardation plate with a pressure-sensitive adhesive layer (λ / 4 plate) produced in the above (b) is further bonded to the pressure-sensitive adhesive layer side of the λ / 4 plate. The side (the side where the light diffusive pressure-sensitive adhesive layer is not provided) is 60 ° with respect to the slow axis of the λ / 2 plate (with respect to the polarization transmission axis of the polarizing plate). The composite polarizing plate was prepared by pasting so as to be 75 °. FIG. 5 is a schematic cross-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.

  Transparent protective layer 2 / polarizer 1 / first pressure-sensitive adhesive layer 6 (25 μm) / retardation plate (λ / 2 plate) 4 / third pressure-sensitive adhesive layer 8 (15 μm) / retardation plate ( λ / 4 plate) 5 / second pressure-sensitive adhesive layer 7a (light diffusive pressure-sensitive adhesive layer, 25 μm) / release film 9.

(D) Evaluation of composite polarizing plate The composite polarizing plate obtained in (c) above was subjected to a heat shock test similar to (d) of Example 1. Also in this example, no defects were observed in the composite polarizing plate after the test, and the good state was maintained.

[Example 3] : Reference (a) Polarizing plate with pressure-sensitive adhesive layer The constitution of transparent protective layer / polarizer / pressure-sensitive adhesive layer A / release film is the same as in (a) of Example 1. A polarizing plate with a pressure sensitive adhesive layer was prepared.

(B) Retardation plate with pressure-sensitive adhesive layer Retardation plate composed of a stretched film of norbornene-based resin, having an in-plane retardation of 270 nm that is λ / 2 with respect to light wavelength λ, and a thickness of 33 μm The light diffusable pressure-sensitive adhesive layer A is bonded to one side of a plate (“Scina film” manufactured by Sekisui Chemical Co., Ltd.) (λ / 2 plate), and a phase difference plate (λ / 2 plate). In addition, a retardation film made of a stretched film of norbornene-based resin and having an in-plane retardation of 90 nm, which is λ / 4 with respect to the wavelength λ of light (“Scina film” manufactured by Sekisui Chemical Co., Ltd.) ( A retardation plate (λ / 4 plate) with a pressure-sensitive adhesive layer in which an acrylic pressure-sensitive adhesive having a thickness of 15 μm was laminated on one side of the (λ / 4 plate) was prepared.

(C) Preparation of composite polarizing plate After peeling the release film from the polarizing plate with pressure-sensitive adhesive prepared in (a) above, the pressure-sensitive adhesive prepared in (b) above on the pressure-sensitive adhesive layer side. The λ / 2 plate side of the phase difference plate with a layer (λ / 2 plate) (the side where the light diffusable pressure-sensitive adhesive layer is not provided) is the slow axis of the λ / 2 plate, and the polarization transmission axis of the polarizing plate. The retardation plate with a pressure-sensitive adhesive layer (λ / 4 plate) prepared in the above (b) is further attached to the pressure-sensitive adhesive layer side with respect to the pressure-sensitive adhesive layer side. On the plate side (the side where the pressure-sensitive adhesive layer is not provided), the slow axis of the λ / 4 plate is 60 ° with respect to the slow axis of the λ / 2 plate (with respect to the polarization transmission axis of the polarizing plate). Was pasted so as to obtain 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 configuration.

  Transparent protective layer 2 / polarizer 1 / first pressure-sensitive adhesive layer 6 (25 μm) / retardation plate (λ / 2 plate) 4 / third pressure-sensitive adhesive layer 8a (light-diffusing pressure-sensitive adhesive layer) 25 μm) / retardation plate (λ / 4 plate) 5 / second pressure-sensitive adhesive layer 8 (15 μm) / release film 9.

(D) Evaluation of composite polarizing plate The composite polarizing plate obtained in (c) above was subjected to a heat shock test similar to (d) of Example 1. Also in this example, no defects were observed in the composite polarizing plate after the test, and the good state was maintained.

[Comparative Example 1]
In Example 1 (b), the light diffusing pressure-sensitive adhesive layer A bonded to one side of the λ / 4 plate was changed to a light diffusing agent-containing pressure-sensitive adhesive layer B, and the others were the same as in Example 1. Thus, a composite polarizing plate was produced. About the obtained composite polarizing plate, the heat shock test similar to (d) of Example 1 was done. Bubbles were observed in the composite polarizing plate after the test.

[Comparative Example 2]
In Example 2 (b), the light diffusing pressure-sensitive adhesive A to be bonded to one side of the λ / 4 plate was changed to a light diffusing agent-containing pressure-sensitive adhesive B, and the others were combined in the same manner as in Example 2. A polarizing plate was produced. About the obtained composite polarizing plate, the heat shock test similar to (d) of Example 1 was done. Bubbles were observed in the composite polarizing plate after the test.

[Comparative Example 3]
In Example 3 (b), the light diffusing pressure-sensitive adhesive A to be bonded to one side of the λ / 2 plate was changed to a light diffusing agent-containing pressure sensitive adhesive B. As a result, the λ / 2 plate and λ / A light diffusing agent-containing pressure sensitive adhesive B having a small storage elastic modulus was disposed between the four plates, and a composite polarizing plate was produced in the same manner as in Example 3. About the obtained composite polarizing plate, the heat shock test similar to (d) of Example 1 was done. Bubbles were observed in the composite polarizing plate after the test.

  The main conditions and results of Examples 1 to 3 and Comparative Examples 1 to 3 are summarized in Table 1. Further, as a representative example of the sample after the heat shock test in these Examples and Comparative Examples, an enlarged photograph of the sample of Example 2 viewed from the transparent protective layer side of the polarizer is shown in FIG. An enlarged photograph of the sample of Example 2 viewed from the transparent protective layer side of the polarizer is shown in FIG. In FIG. 8, in the sample of Comparative Example 2 shown in (B), a plurality of bubbles reflected in an ellipse shape are observed, whereas in the sample of Example 2 shown in (A), such bubbles are observed. Thus, it can be seen that a good state is maintained.

Light diffusing agent-containing adhesive material layers C to L:
An ethyl acetate solution (solid content: 14% by mass) of an adhesive material having the composition (solid content) shown in Table 2 was prepared, and a release film made of polyethylene terephthalate having a thickness of 38 μm [“SP-PET3811” manufactured by Lintec Corporation] was peeled off. On the layer, after apply | coating with a knife type coating machine so that the thickness after drying might be set to 25 micrometers, it dried at 90 degreeC for 1 minute, and formed the light diffusing agent containing adhesive material layer CL.

Light diffusing agent-free adhesive material layers C to L:
An ethyl acetate solution (solid content 14% by mass) of an adhesive material having a composition obtained by removing silicon beads from the composition (solid content) shown in Table 2 was prepared, and a release film made of polyethylene terephthalate having a thickness of 38 μm [manufactured by Lintec Corporation] [SP-PET3811]] was coated with a knife coater so that the thickness after drying was 25 μm, and then dried at 90 ° C. for 1 minute to contain no light diffusing agent. Material layers C to L were formed.

Light-diffusing pressure-sensitive adhesive layers C to J and light diffusing agent-containing pressure-sensitive adhesive layers KL:
The light diffusing agent-containing pressure-sensitive adhesive layers C to L are irradiated with ultraviolet rays under the following conditions, whereby a light diffusing pressure-sensitive adhesive layer (single) C to J and a light diffusing agent-containing pressure sensitive adhesive layer (single) K ~ L was obtained. These pressure-sensitive adhesive layers were used for calculation of storage elastic modulus, haze value, and gel fraction value in Table 3-1.
<Ultraviolet irradiation conditions>
Fusion Co. electrodeless lamp H bulb used, illuminance 600 mW / cm ^2, light quantity 150 mJ / cm ²
As the ultraviolet illuminance / light meter, “UVPF-36” manufactured by Eye Graphics Co., Ltd. was used.

(A ′) Polarizing plate with light diffusing agent-containing adhesive material layer Transparent protection composed of a 40 μm thick triacetyl cellulose film on one side of a 25 μm thick polarizer in which iodine is adsorbed and oriented on polyvinyl alcohol A polarizing plate in which layers were bonded together with an epoxy adhesive was prepared. The light diffusing agent-containing adhesive material layer is bonded to the polarizer side in accordance with Table 3-1, and the light diffusion is a configuration of transparent protective layer / polarizer / light diffusing agent-containing adhesive material layer / release film. agent-containing pressure-sensitive material layer with a polarizing plate was created made.

(B ′) Retardation plate with light diffusing agent-free adhesive material layer A retardation plate comprising a stretched film of norbornene-based resin, having a thickness of 40 μm and an in-plane retardation of 140 nm (manufactured by Sekisui Chemical Co., Ltd.) The above-mentioned light diffusing agent-free adhesive material layer is bonded to one side of essina film ") (λ / 4 plate), and retardation plate (λ / 4 plate) / light diffusing agent-free adhesive material layer / A phase difference plate with a light diffusing agent-free adhesive material layer, which is a configuration of a release film, was produced.

(C ′) Preparation of Composite Polarizing Plate After peeling the release film from the polarizing plate with the light diffusing agent-containing adhesive material layer prepared in (a ′) above, The phase difference plate side (the side where the light diffusion agent-free adhesive material layer is not provided) of the phase difference plate with the light diffusion agent-free adhesive material layer prepared in b ′) Bonding was performed so that the axis was 45 ° with respect to the polarization transmission axis of the polarizing plate.
Next, composite polarizing plates corresponding to Examples 4 to 11 and Comparative Examples 4 to 5 in Table 3-2 are prepared by irradiating ultraviolet rays from the side of the release film bonded to the retardation plate under the following conditions. did.
<Ultraviolet irradiation conditions>
Fusion Co. electrodeless lamp H bulb used, illuminance 600 mW / cm ^2, light quantity 150 mJ / cm ²
As the ultraviolet illuminance / light meter, “UVPF-36” manufactured by Eye Graphics Co., Ltd. was used.

FIG. 7 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 configuration.
Examples 4-11
Transparent protective layer 2 / polarizer 1 / first pressure sensitive adhesive layer 7a (light diffusive pressure sensitive adhesive layer, 25 μm) / retardation plate (λ / 4 plate) 5 / second pressure sensitive adhesive layer 6 (Pressure-sensitive adhesive layer, 25 μm) / release film 9.
Comparative Examples 4-5
Transparent protective layer 2 / polarizer 1 / first pressure sensitive adhesive layer 7a (light diffusing agent-containing pressure sensitive adhesive layer, 25 μm) / retardation plate (λ / 4 plate) 5 / second pressure sensitive adhesive Layer 6 (pressure sensitive adhesive layer, 25 μm) / release film 9.

(D ′) Evaluation Result of Composite Polarizing Plate The composite polarizing plates of Examples 4 to 11 that satisfy the requirements of the present invention are Comparative Examples 4 to 5 that do not satisfy the requirements of the present invention as shown in Table 3-2. Compared with the composite polarizing plate, the result was extremely excellent in durability.

(note)
1) Acrylic copolymer: butyl acrylate and acrylic acid in a mass ratio of 95: 5, polymerized according to a conventional method, and having a weight average molecular weight of 1.8 million 2) Multifunctional acrylate monomer : Tris (acryloxyethyl) isocyanurate, molecular weight = 423, trifunctional type (trade name “Aronix M-315” manufactured by Toa Gosei Co., Ltd.)
3) Photopolymerization initiator: mixture of benzophenone and 1-hydroxycyclohexyl phenyl ketone in a mass ratio of 1: 1, “Irgacure 500” manufactured by Ciba Specialty Chemicals
4) Isocyanate-based crosslinking agent: trimethylolpropane-modified tolylene diisocyanate (“Coronate L” manufactured by Nippon Polyurethane)
5) Silane coupling agent: 3-glycidoxypropyltrimethoxysilane (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.)
6) Silicone beads: Spherical silicone fine particles (“Tospearl 145” manufactured by GE Toshiba Silicones, average particle size: 4.5 μm)

(note)
7) Adhesive residue is observed.

  The present invention relates to a composite polarizing plate comprising a polarizer, a retardation plate and a pressure-sensitive adhesive layer, a laminated optical member laminated on another optical layer, and an image display such as a liquid crystal cell using the composite polarizing plate or laminated optical member. The present invention can be applied to an image display device combined with an element.

Claims (17)

A transparent protective layer is arranged on one side of a polarizer made of a polyvinyl alcohol-based resin film, and at least one retardation plate is laminated via a first pressure-sensitive adhesive layer arranged directly on the other side of the polarizer. A composite polarizing plate in which a second pressure-sensitive adhesive layer is disposed outside the retardation plate located on the side farthest from the polarizer,
Among the pressure-sensitive adhesive layers existing between the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, at least the first pressure-sensitive adhesive layer is (A) acrylic An adhesive material obtained by dispersing a light diffusing agent in an adhesive resin composed of a copolymer and (B) an active energy ray-curable compound is irradiated with active energy rays, and at 0.degree. A composite polarizing plate, which is a light diffusive pressure-sensitive adhesive layer exhibiting a storage elastic modulus of 3 to 10 MPa. The composite polarizing plate according to claim 1 , wherein the light diffusable pressure-sensitive adhesive layer exhibits a storage elastic modulus of 0.15 to 10 MPa at 80 ° C. 2. Retardation plate, a composite polarizer according to claim 1 or 2, which is one. The composite polarizing plate according to claim 1 or 2 , wherein the number of retardation plates is two, and both retardation plates are bonded via a third pressure-sensitive adhesive layer. The light diffusing pressure-sensitive adhesive layer contains a light diffusing agent having an average particle diameter of 0.1 to 20 [mu] m, the composite polarizing plate according to any one of claims 1-4 F haze value is 5% or more . Composite polarizing plate according to the light diffusing pressure-sensitive adhesive layer, either a storage modulus 0.3~10MPa shown in to請 Motomeko 1-5 at 80 ° C.. Gel fraction of the light diffusing pressure-sensitive adhesive layer, the composite polarizer according to any one of claims 1 to 6 60% or more. The composite polarizing plate according to any one of claims 1 to 7, wherein (B) the active energy ray-curable compound constituting the adhesive resin is a polyfunctional (meth) acrylate monomer having a molecular weight of less than 1000. The composite polarizing plate according to claim 8 , wherein the polyfunctional (meth) acrylate monomer has a cyclic structure. The composite polarizing plate according to claim 9 , wherein the polyfunctional (meth) acrylate monomer has an isocyanurate structure. The content of the constituting the pressure-sensitive resin (A) and acrylic copolymer (B) the active energy ray-curable compound, 100 weight ratio: 1 to 100: any of claims 1 to 10 is 100 A composite polarizing plate according to any one of the above. Composite polarizing plate according to any one of the sticky material, according to claim 1 to 11 in which further comprising a crosslinking agent (C). It said composite polarizing plate according to the adhesive material, any one of claims 1 to 12, in which further comprises a (D) silane coupling agent. The light diffusing pressure-sensitive adhesive layer, the composite polarizing plate according to any one of claims 1 to 13 that has a haze value of 20 to 90%. The light diffusing pressure-sensitive adhesive layer, the composite polarizing plate according to any one of claims 1-14 that has a thickness of 1 to 40 [mu] m. A laminated optical member comprising a laminate of the composite polarizing plate according to any one of claims 1 to 15 and an optical layer exhibiting another optical function. An image display device comprising: an image display element; and the composite polarizing plate according to any one of claims 1 to 15 or the laminated optical member according to claim 16 .

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