TWI826911B - Polarizing plates and display devices - Google Patents

Abstract

The present invention provides a means to reduce display unevenness. The present invention relates to a display device having a polarizing plate and a display device unit, wherein the polarizing plate has a polarizer and an optical film, the optical film has at least a base material, the base material contains at least a cycloolefin resin, and the optical film The refractive index difference from the aforementioned polarizer satisfies the following formula (1), Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02 When the aforementioned display device displays black, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.34.

Description

Polarizing plates and display devices

The present invention relates to polarizing plates and display devices.

In recent years, as the uses of display devices have expanded, display devices have been required to have higher image quality and higher definition. Recently, 4K TVs (TVs with approximately four times the number of pictures of ultra-high-definition TVs) have been commercially available. In addition, in the future, there will be a demand for even higher contrast display devices such as 8K TVs. In addition, known methods for improving the image quality and high definition of the display device include reducing the pixel size, increasing the amount of light, or accelerating the response speed of an active drive type using thin film transistors.

Among such display devices, a liquid crystal display device is generally known, which includes a liquid crystal panel including a light source side polarizing plate, a liquid crystal cell, and a viewing side polarizing plate in this order, and a light source that irradiates the liquid crystal panel with light. In addition, in liquid crystal display devices, various optical films are used for the purpose of protecting the polarizer included in the polarizing plate, expanding the viewing angle, or improving display characteristics. As such optical film materials, cellulose ester resin or polycarbonate resin has been conventionally used. Furthermore, in recent years, resins containing polymers having an alicyclic structure have attracted attention from the viewpoints of high heat resistance, low hygroscopicity, and low photoelastic constant. As an optical film using a resin containing a polymer having an alicyclic structure, Japanese Patent Application Laid-Open No. 2016-79210 discloses a multilayer film composed of a thermoplastic resin containing a polymer having a molecular weight above a specified value. A stretched film layer, and a cured layer of a coating film of a polyurethane-containing coating liquid provided on at least one side of the stretched film layer. Furthermore, Japanese Patent Application Publication No. 2016-79210 discloses a polarizing plate having the multi-layer film, and a liquid crystal display device including the multi-layer film or the polarizing plate including the same. Furthermore, Japanese Patent Application Publication No. 2016-79210 also discloses that the multilayer film has excellent adhesion to the polarizer included in the polarizing plate.

Regarding the display device, the present inventors discovered that depending on the type of optical film used in the display device, display unevenness recognized as screen roughness is recognized when viewed from an oblique direction. In addition, in recent years, display devices have been industrially produced, and when the display devices are used for display, it has been confirmed that the frequency or degree of display unevenness recognized as brightness unevenness varies between display devices, and the display varies between the devices. The difference in display quality becomes larger. Moreover, display devices using the multi-layer film described in Japanese Patent Application Publication No. 2016-79210 or the polarizing plate cannot eliminate the above-mentioned display unevenness, and there is still room for improvement.

Therefore, an object of the present invention is to provide a means for reducing display unevenness.

The above problems of the present invention can be solved by the following means: A display device having a polarizing plate and a display device unit, wherein The aforementioned polarizing plate has a polarizer and an optical film, The aforementioned optical film has at least a base material, The aforementioned base material contains at least a cycloolefin resin, and the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (1); Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02; When the aforementioned display device displays black, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.34.

In addition, the above-mentioned problems of the present invention can also be solved by the following means: A display device having a polarizing plate and a display device unit, wherein The aforementioned polarizing plate has a polarizer and an optical film, The aforementioned optical film has at least a base material, The aforementioned base material contains at least a cycloolefin resin, and the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (1); Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02 When the aforementioned display device displays black, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.30.

In addition, the above-mentioned problems of the present invention can also be solved by the following means: A polarizing plate having a polarizer and an optical film, wherein The aforementioned optical film has at least a base material, The aforementioned base material contains at least a cycloolefin resin, and the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (1); Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02; When the display device displays black with the polarizing plate assembled in the display device, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.34.

In addition, the above-mentioned problems of the present invention can also be solved by the following means: A polarizing plate having a polarizer and an optical film, wherein The aforementioned optical film has at least a base material, The aforementioned base material contains at least a cycloolefin resin, and the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (1); Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02 When the above-mentioned polarizing plate is assembled in a display device and the above-mentioned display device displays black, the RMS granularity of a display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.30.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings as necessary. In addition, in the description of the drawings, the same elements are assigned the same symbols, and repeated explanations are omitted. In addition, the dimensional ratios in the drawings may be exaggerated to fit the description smoothly and may differ from the actual ratios.

In this specification, "X~Y" indicating a range means "above X and below Y". In addition, unless otherwise noted, operation and physical properties are measured under the conditions of room temperature (20~25℃)/relative humidity 40~50%RH.

In this specification, (co)polymer refers to a general term including copolymers and homopolymers.

In addition, in this specification, "(meth)acrylate" refers to the general term of acrylate and methacrylate. Compounds containing (meth) such as (meth)acrylic acid are also collectively referred to as compounds having "methyl" in their names and compounds that do not have "methyl".

＜Display device＞ One aspect of the present invention relates to a display device having a polarizing plate and a display device unit, wherein the polarizing plate has a polarizer and an optical film, the optical film has at least a base material, the base material has at least a cycloolefin resin, and The refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (1); Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02 When the aforementioned display device displays black, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.34.

A preferred embodiment of the present invention relates to a display device having a polarizing plate and a display device unit, wherein the polarizing plate has a polarizer and an optical film, the optical film has at least a base material, and the base material contains at least a cyclic olefin Resin, and the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (1); Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02 When the aforementioned display device displays black, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.30.

According to the present invention, a means for reducing display unevenness can be provided.

The inventors of the present invention speculate that the mechanism for solving the problems by the present invention is as follows.

As display devices become more pixelated and high-definition by reducing the pixel size, the control of linearity of light will be improved accordingly. However, in this case, light interference (moiré) or the like between pixel grids becomes easy to occur. When reducing the pixel size, it is difficult to make the size completely uniform. Furthermore, due to subtle differences in pixel size at different locations within the display device, the frequency or degree of light interference between pixel grids will also be different. As a result, the picture may become rough. The roughness of the image becomes noticeable especially when viewed from an oblique direction. In addition, due to subtle differences in pixel size between display devices, the frequency or degree of light interference between pixel grids will also be different, so uneven brightness will also occur between display devices. Display quality deviation. These results lead to display unevenness in the display device.

Since the RMS particle size is related to the deviation of the density of the image, it is believed that the RMS particle size closer to 0 will lead to better display unevenness. However, the present inventors found that when the RMS particle size is above the specified value, the display will still be uneven. Reduce display unevenness. In addition, when considering the impact of the refractive index difference between the optical film and the polarizer on light, it is believed that the display unevenness will become better if its absolute value is closer to 0, regardless of its positive or negative value. However, surprisingly, the inventors found that when the refractive index difference between the optical film and the polarizer (refractive index of the optical film - the refractive index of the polarizer) is greater than 0, display unevenness will be reduced. Moreover, as a result of repeated examinations, the present inventors found that the RMS grain size of photographic images taken from a specific direction of the display device can be set within a specific range, and by using the optical film in the polarizing plate of the display device and polarizing If the refractive index difference of the device satisfies the specified relationship, the display unevenness that is recognized as brightness unevenness as a difference in display quality between display devices will be well suppressed, and the display unevenness that is recognized as screen roughness will also be suppressed. Reduce. The reason for this is considered to be that the display device of the present invention deliberately scatters light emitted from the display device slightly in order to eliminate light interference between pixel grids. Although the detailed reason is unknown, it is believed that the above-mentioned RMS particle size, the above-mentioned optical film, and the difference in refractive index between the polarizer and the polarizer are particularly beneficial in eliminating light interference between pixel grids by changing the scattering properties of light.

In addition, the above-mentioned mechanism is only based on speculation, and its accuracy does not affect the technical scope of the present invention.

RMS particle size refers to one of the evaluation indexes of granularity, and it is known that the density deviation of a photographic image is expressed as the root mean square (RMS).

When the display device according to one embodiment of the present invention displays black, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side (the RMS granularity of the display device) is 0.30 to 1.34. 0.30~1.30 is better.

The above-mentioned RMS particle size (RMS particle size of the display device) represents the polarization relative to the polarizing plate (when there is a plural number, any polarizing plate of interest, preferably the viewing side polarizing plate) when the display device displays black. The absorption axis direction of the device is rotated along the display surface at +45°, +135°, +225° (-135°), and +315° (-45°) and tilted 10 degrees from the display surface toward the viewing side. The average RMS granularity (RMS granularity at a specific angle) of the display image photographed at the ° position.

Therefore, in this specification, the average value of the RMS granularity of each display image photographed from the above four positions is also simply referred to as the "RMS granularity of the display device." In addition, the RMS granularity of each display image photographed at a position tilted 10° from the display surface toward the viewing side at a specific angle of the display surface is also simply referred to as the "RMS granularity at a specific angle."

If the RMS granularity of the display device is less than 0.30, the variation in display quality between display devices, especially the display unevenness recognized as brightness unevenness, will increase. In addition, if the RMS granularity of the display device exceeds 1.30, especially if it significantly exceeds 1.34, display unevenness, especially display unevenness recognized as screen roughness, will increase.

In this specification, the "top" of a certain part means "right above" a certain part, or it may include other parts between the highlighted part and the certain part.

In this manual, "the position that is tilted 10° from the display surface toward the viewing side" means that the plane on which the display surface of the display device exists is set to 0°, and the position of the display surface that serves as the reference for photography is oriented toward the display. The normal direction (vertical direction) side of the surface on the observer side (viewing side, front side) becomes a straight line position at an angle of 10°.

Hereinafter, "the position tilted 10° from the display surface toward the viewing side" will be explained using FIG. 1 . Figure 1 is a schematic diagram illustrating the photographic position used to evaluate the RMS grain size. In FIG. 1 , the position of the display surface 1 of the display device as the reference position for photography is set as the reference position O. Regarding the reference position O, the plane on which the display surface 1 exists is set to 0°, and the normal direction (vertical direction) toward the observer side (viewing side, front side) of the display surface 1, that is, the Z direction side is an angle of 10°. The position on the straight line L is "the position tilted 10° from the display surface toward the viewing side." The same judgment is made for the position tilted toward the viewing side from the display surface other than this angle.

In the display device according to one embodiment of the present invention, it is preferable that the display device unit includes a display unit, and at least one polarizing plate is disposed on the viewing side (observer side, front side) of the display unit of the display device unit. In addition, it is preferable that one polarizing plate is arranged on the viewing side (observer side, front side) of the display unit of the display device unit.

In the display device according to one embodiment of the present invention, when the polarizing plate is disposed on the viewing side (observer side, front side) of the display unit of the display device unit, when the display device displays black, the polarizing plate is The polarizer's absorption axis direction is rotated along the display surface at +45°, +135°, +225°, and +315° in each direction, and the display image is photographed at a position tilted 10° from the display surface toward the viewing side. The average value of the RMS particle size (the RMS particle size of the display device) is preferably 0.30~1.34, and preferably 0.30~1.30. The reason is that display unevenness is particularly likely to occur when the display surface is rotated by +45°, +135°, +225°, or +315° relative to the direction of the absorption axis of the polarizing plate on the viewing side. Photographing from this position is By keeping the RMS granularity of the image within the above range, the effect of significantly reducing display unevenness can be achieved. Based on the same point of view, with respect to the direction of the absorption axis of the polarizer of the above-mentioned polarizing plate, the display surface is tilted from the display surface toward the viewing side in each direction of +45°, +135°, +225°, or +315° rotation along the display surface. The RMS granularity (RMS granularity at a specific angle) of the display image photographed at a position of 10° is preferably 0.30~1.34, and 0.30~1.30 is even more preferably.

Here, the "directions of +45°, +135°, +225°, and +315° rotated along the display surface with respect to the direction of the absorption axis of the polarizer" of the polarizing plate on the viewing side refer to individual indications on the display device. On the display surface as a photographic reference position, set the absorption axis direction of the polarizer of the polarizer on the viewing side (observer side, front side) of the display unit to 0°, and rotate it +45 with the counterclockwise direction as a positive value. °, +135°, +225°(-135°), and +315°(-45°) directions on the display surface.

Hereinafter, using Figure 2, an explanation will be given as an example of "a position tilted 10° from the display surface toward the viewing side in the direction of +45° rotation along the display surface with respect to the absorption axis direction of the polarizer of the viewing side polarizing plate." . 2 is a diagram illustrating the +45° rotation direction along the display surface with respect to the absorption axis direction of the polarizer of the polarizing plate (viewing side polarizing plate) disposed on the viewing side (observer side, front side) of the display unit. Above, a pattern diagram of the photographic position used to evaluate the RMS grain size. In FIG. 2 , the position of the display surface 1 of the display device as the reference position for photography is set as the reference position O. In addition, let the direction on the display surface 1 that is orthogonal to the absorption axis direction a of the polarizer of the polarizer arranged on the viewing side of the display unit be the X direction, and let the direction of the absorption axis direction a of the polarizer be Y direction. Moreover, let the direction orthogonal to the X direction and the Y direction and the viewing side (observer side, front side) with respect to the display surface 1 be the Z direction. Here, the Z direction is the normal direction (vertical direction) of the observer side (viewing side, front side) of the display surface 1 . At this time, "the position that is tilted 10° from the display surface toward the viewing side in the direction of rotation of +45° along the display surface with respect to the direction of the absorption axis of the polarizer of the viewing side polarizing plate" means the following position. First, at the reference position O, imagine that the direction of the absorption axis direction a (Y direction) of the polarizer of the viewing side polarizing plate on the display surface 1 is set to 0°, and then rotated in the direction of +45° along the display surface. In addition, with respect to the reference position O in this direction, the plane on which the display surface 1 exists is set to 0°, and the normal direction (vertical direction) toward the observer side (viewing side, front side) of the display surface 1, that is, the Z direction side The position on the straight line L (45) with an angle of 10° is the direction of rotation of +45° along the display surface with respect to the absorption axis direction of the polarizer of the viewing side polarizing plate, tilted from the display surface toward the viewing side. 10° position". Furthermore, regarding "the position tilted 10° from the display surface toward the viewing side in the direction of rotation of +135°, +225°, and +315° along the display surface with respect to the direction of the absorption axis of the polarizer of the viewing side polarizing plate. ” It is also judged in the same way as the case of +45° mentioned above. In addition, the angles other than these with respect to the absorption axis direction of the polarizer of the viewing side polarizing plate are also determined in the same manner.

Furthermore, based on the same viewpoint, in the display device according to one embodiment of the present invention, when the polarizing plate is disposed on the viewing side (observer side, front side) of the display unit of the display device unit, when the display device displays black, Photography is taken in a direction in which the display surface is rotated at 45° intervals from 0° to less than +360° with respect to the absorption axis direction of the polarizer of the polarizer, and is tilted 10° from the display surface toward the viewing side. The RMS granularity of the displayed image (RMS granularity at a specific angle) is preferably 0.30~1.34, and 0.30~1.30 is even better.

Furthermore, when two or more polarizing plates are arranged on the viewing side of the display unit of the display device unit, the RMS particle size is measured based on the absorption axis direction of the polarizer of the viewing side polarizing plate arranged closest to the display unit. Just use it as a baseline.

Furthermore, when the display device unit includes a display unit and at least one polarizing plate is disposed on the viewing side (observer side, front side) of the display unit of the display device unit, the polarizing plate is positioned between the viewing side (observer side) of the display unit. , front side) It is better to configure at least 1 polarizing plate on the opposite side. In addition, in this case, it is preferable to dispose one polarizing plate on the side opposite to the viewing side (observer side, front side) of the display unit.

Furthermore, in the display device according to one embodiment of the present invention, the display device unit may include a display unit, but the polarizing plate may not be disposed on the viewing side (observer side, front side) of the display unit of the display device unit. At least one polarizing plate is disposed only on the side (back side) of the display device unit opposite to the viewing side of the display unit. In this case, the RMS particle size can be measured based on the absorption axis direction of the polarizer placed on the back side of the polarizing plate. At this time, when two or more polarizing plates are arranged on the back side of the display unit of the display device unit, the absorption axis direction of the polarizer of the back side polarizing plate arranged closest to the display unit may be used as a reference. .

There are no special restrictions on the RMS granularity of the display device and the RMS granularity of the specific angle as long as they are within the above ranges. 0.30~1.00 is preferred, 0.40~0.70 is preferred, and 0.40~0.60 is preferred. Within this range, display unevenness will be further reduced.

RMS particle size can be measured by the following operations.

(Step 1) Obtain image Using a camera (e.g. Sony Co., Ltd. (SONY) α7sII) and lens (e.g. Canon Co., Ltd. (Canon) EF 70-200mm F2.8L IS II USM) at ISO 25,600, F 2.8, in a darkroom Below, the display surface is photographed when the LCD device displays black from a position tilted 10° from the display surface toward the viewing side. Furthermore, the distance between the position of the display surface as the reference point for photography and the camera is set to 50cm. Moreover, photography can also be done using a general-purpose camera.

The RMS particle size of the display device is calculated by rotating along the display surface from the direction of the absorption axis of the polarizer relative to the polarizer (in the case of a plurality of numbers, any of the polarizers attracting attention, preferably the viewing side polarizer) + Photography is performed at a position tilted 10° from the display surface toward the viewing side in each direction of 45°, +135°, +225° (-135°), and +315° (-45°).

(Step 2) Analyze the obtained image According to the following operation sequence, the RMS granularity is calculated from the photographic image: 1. Use free software (imageJ) to read the two-dimensional (plane) data of the obtained photographic image; 2. Set a 2.8cm×4cm rectangular evaluation area in the actual photographic image; 3. Grayscale conversion using free software (ImageJ); 4. If necessary, perform background correction on the read two-dimensional data in the aforementioned evaluation area; 5. Calculate the RMS granularity from the standard deviation σ of the gray scale value (pixel value) under gray scale. That is, the standard deviation σ is regarded as the RMS granularity of the display image at the measurement angle (the angle along the display surface) (the RMS granularity at a specific angle); 6. Calculate the rotation of +45° and +135 along the display surface in the direction of the absorption axis of the polarizer relative to the polarizer (if there is a plurality of numbers, it is any polarizer that attracts attention, preferably the viewing side polarizer). RMS granularity of display images photographed at a position tilted 10° from the display surface toward the viewing side in each direction of °, +225° (-135°), and +315° (-45°) (RMS at a specific angle) particle size) as the RMS particle size of the display device.

Here, the free software ImageJ refers to ImageJ1.32S produced by Wayne Rasband. On the other hand, regarding the software used in 1 above, software such as WinROOF can also be used.

Background correction is performed using a polynomial when, for example, the right and left halves of the image are output as different brightnesses even though they have the same brightness, or are output as a result of gradually becoming brighter from the left to the right of the image. to approximate the concentration gradient and eliminate the concentration gradient mathematically.

Use the following method to calculate the standard deviation σ of the gray-scale value under the gray scale: Taking N data of gray-scale values x ₁ , x ₂ ,..., x _N as the parent group, it is calculated by the following mathematical formula (I) Find the summed average (parent average) m of the parent group.

[Number 1]

Next, using the mother average m obtained above, the dispersion σ ² is obtained by the following mathematical formula (II).

[Number 2]

The positive square root of this dispersion σ ² is defined as the standard deviation σ.

In addition, the details of the evaluation method of the RMS particle size are described in the Examples.

The RMS particle size of the display device changes in association with the optical properties such as the refractive index of the cycloolefin resin base material (base material containing cycloolefin resin) described later, optional functional layer and polarizer described later. Here, the method of controlling the refractive index of the cycloolefin resin base material (base material containing cycloolefin resin), optional functional layers, and optical films containing them is as described below. The RMS particle size of the display device is reduced if the difference in the refractive index of the optical film containing the cycloolefin resin base material (the base material containing the cycloolefin resin) and the refractive index of the polarizer becomes small, and the difference in the refractive index becomes The tendency will increase. However, as mentioned above, if the RMS particle size of the display device is too small, display unevenness will occur. Therefore, the present invention not only reduces the refractive index of the optical film containing the cycloolefin resin base material (the base material containing the cycloolefin resin) and the polarizer. The difference in refractive index must be made in such a way that the RMS particle size of the display device becomes an optimal range.

The following describes the details of the polarizing plate and the display device unit included in the display device according to one aspect of the present invention.

[Polarizing plate] A display device according to an embodiment of the present invention includes one or more polarizing plates. At least one of the polarizing plates included in the display device according to an embodiment of the present invention includes a polarizer and one or more optical films. Furthermore, the entire polarizing plate included in the display device according to an embodiment of the present invention preferably includes a polarizer and one or more optical films.

In a display device according to an embodiment of the present invention, at least one polarizing plate includes one or more optical films. The number of optical films included in the polarizing plate is not particularly limited, but it is preferably two or more, and two is particularly preferred. Furthermore, the polarizing plate preferably has at least one optical film on both sides of the polarizer, and preferably has at least one optical film on both sides of the polarizer.

(Optical films including base materials containing cycloolefin resin) ・Substrate containing cycloolefin resin In a display device according to an embodiment of the present invention, at least one polarizing plate includes an optical film, and the optical film includes a base material containing a cycloolefin resin. The optical film may be composed only of a base material containing a cycloolefin resin, or may further have one or two or more types of functional layers described below on the base material containing a cycloolefin resin.

In at least one polarizing plate included in a display device according to an embodiment of the present invention, an optical film including a base material containing a cycloolefin resin can be disposed on one side of the polarizer or on both sides of the polarizer. superior.

That is, in at least one polarizing plate included in a display device according to an embodiment of the present invention, at least one optical film included in the polarizing plate includes a base material containing a cycloolefin resin. Among the optical films included in the polarizing plate, it is preferable that at least one optical film disposed on one side of the polarizer includes a base material containing a cycloolefin resin. At this time, one or more optical films may be disposed on the other side of the polarizer, or no optical film may be disposed. Furthermore, it is preferable that an optical film is disposed on the polarizer side of the polarizing plate, and the optical film includes a base material containing a cycloolefin resin. At this time, one or more optical films may be disposed on the other side of the polarizer, or no optical film may be disposed, but it is better to dispose one other optical film as described below.

Hereinafter, a base material containing a cycloolefin resin will also be simply referred to as a "cycloolefin resin base material".

The base material containing cyclic olefin resin contains cyclic olefin resin.

The cycloolefin resin is not particularly limited as long as it is a (co)polymer containing a structural unit having an alicyclic structure. A (co)polymer containing a structural unit having an alicyclic structure may have an alicyclic structure in the main chain or may have an alicyclic structure in a side chain. Among these, from the viewpoint of controlling the refractive index, a (co)polymer having an alicyclic structure in the main chain is preferred.

Examples of the alicyclic structure include a saturated alicyclic hydrocarbon (cycloalkane) structure, an unsaturated alicyclic hydrocarbon (cycloalkene, cycloalkyne) structure, and the like. Among them, from the viewpoint of mechanical strength, heat resistance, etc., a cycloalkane structure or a cycloolefin structure is preferred, and a cycloalkane structure is particularly preferred.

The number of carbon atoms constituting the alicyclic structure is not particularly limited. It is preferable that the number of carbon atoms per alicyclic structure is 4 or more, and more preferably 5 or more. If it is within the above range, the storage stability becomes even better. Moreover, the number of carbon atoms constituting the alicyclic structure is preferably 30 or less per alicyclic structure, more preferably 20 or less, and more preferably 15 or less. If it is within the above range, the operability of the film becomes better.

As the cycloolefin resin, a (co)polymer containing a structural unit derived from a cycloolefin monomer is preferred. The cycloolefin monosystem is a compound that has a ring structure formed by carbon atoms and has a polymerizable carbon-carbon double bond in the ring structure. The polymerizable carbon-carbon double bond is not particularly limited, and examples thereof include carbon-carbon double bonds capable of polymerization such as ring-opening polymerization. Examples of the ring structure of the cycloolefin monomer include a monocyclic ring, a polycyclic ring, a condensed polycyclic ring, a crosslinked ring, and a polycyclic ring formed by combining these. Among them, polycyclic cycloolefin monomers are preferred from the viewpoint of controlling the refractive index.

Examples of the cycloolefin resin include (co)polymers containing structural units derived from monomers containing a norbornene structure, and (co)polymers containing structural units derived from monomers containing a monocyclic cyclic olefin. ) polymer, a (co)polymer containing a structural unit derived from a monomer containing a cyclic conjugated diene structure, etc. The (co)polymers may also be in the hydride state.

The cycloolefin resin is not particularly limited, and examples thereof include (co)polymers containing structural units derived from tricyclo[4.3.0.1 ^2,5 ]dec-3-ene, tricyclo[4.3. 0.1 ^2,5 ]dec-3,7-diene (common name: dicyclopentadiene), 7,8-benzotricyclo[4.3.0.1 ^2,5 ]dec-3-ene (common name: bridge Methylenetetrahydrofuran), tetracyclo[4.4.0.1 ^2,5 .1 ^7,10 ] dodec-3-ene (common name: tetracyclododecene), compounds 1 to 34 described below, and the like Monomers containing norbornene structures such as derivatives of compounds (for example, those with substituents on the ring); 1,3-dimethyldodecahydrocyclopenta[a]indene, and its derivatives (for example, Those with substituents on the ring) and other monomers. Incidentally, compound 5 described below is bicyclo[2.2.1]hept-2-ene (common name: norbornene). Here, examples of the substituent include an alkyl group, an alkylene group, a polar group, and the like. In addition, these substituents may be the same or different, and may be bonded to the ring in plural. The type of polar group is not particularly limited, and examples thereof include heteroatoms, atomic groups containing heteroatoms, and the like. The hetero atom is not particularly limited, and examples thereof include oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, and halogen atoms. Specific examples of the polar group are not particularly limited, but include, for example, a carboxyl group, a carbonyl group, an oxycarbonyl group, an epoxy group, a hydroxyl group, an oxy group, an ester group, a silanol group, a silicone group, an amine group, and a nitrile group. Sulfonic acid groups, groups other than polar groups substituted by these groups, groups other than polar groups connected via these groups, etc.

Furthermore, the cycloolefin resin is not particularly limited. Examples of (co)polymers containing structural units derived from monomers containing monocyclic cyclic olefins include cyclohexene, cycloheptene, A (co)polymer having a structural unit of a monocyclic cyclic olefin monomer such as cyclooctene.

Furthermore, the cycloolefin resin is not particularly limited, and examples thereof include cyclization reactions of addition polymers of conjugated diene monomers such as 1,3-butadiene, isoprene, and chloroprene. The resulting (co)polymers, or 1,2- or 1,4-addition polymers of cyclic conjugated diene monomers such as cyclopentadiene and cyclohexadiene, and their hydrogenation Things etc.

Among these, a (co)polymer containing a structural unit derived from a monomer containing a norbornene structure is preferred from the viewpoint of controlling the refractive index. The (co)polymer containing a structural unit derived from a monomer containing a norbornene structure is not particularly limited, and examples thereof include ring-opened (co)polymers containing a monomer containing a norbornene structure, and Its hydride; addition (co)polymer of monomers containing norbornene structure, and its hydride, etc. Here, the ring-opened polymer containing a monomer with a norbornene structure is not particularly limited, and examples thereof include a ring-opened homopolymer containing one type of monomer with a norbornene structure, a ring-opened polymer containing a norbornene structure, Ring-opening copolymers of two or more types of monomers, monomers containing norbornene structure, and ring-opening copolymers of monomers other than monomers containing norbornene structure that can be copolymerized therewith. In addition, the addition polymer of a monomer containing a norbornene structure is not particularly limited, and examples thereof include an addition homopolymer of one type of monomer containing a norbornene structure, and a homopolymer containing a norbornene structure. Addition copolymers of two or more types of monomers, monomers containing norbornene structure, and addition copolymers of monomers other than monomers containing norbornene structure that can be copolymerized with them. Among them, from the viewpoint of improving surface uniformity, a copolymer containing a structural unit derived from a monomer containing a norbornene structure and a structural unit derived from a monomer other than a monomer containing a norbornene structure is used. Preferably, it is a ring-opened copolymer containing a monomer containing a norbornene structure, and a monomer other than a monomer containing a norbornene structure that can be copolymerized therewith, or a monomer containing a norbornene structure, and can Addition copolymers of monomers other than monomers containing norbornene structure copolymerized therewith are preferred.

Preferable examples of the cycloolefin resin are not particularly limited, and examples thereof include (co)polymers containing structural units derived from the cycloolefin monomer represented by the following general formula (A). The (co)polymer is a type of (co)polymer containing a structural unit derived from a monomer containing a norbornene structure. This (co)polymer is particularly suitable when producing a cycloolefin resin base material by a solution film forming method.

Each R in the general formula (A) independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, or a polar group. In addition, a and b in the general formula (A) each independently represent an integer above 0.

In addition, a preferred example of the cycloolefin resin is not particularly limited, and examples thereof include resins derived from a cycloolefin monomer represented by the following general formula (A-1) or the following general formula (A-2). Constituent units of (co)polymers, etc. The (co)polymer is a type of (co)polymer containing a structural unit derived from a monomer containing a norbornene structure. This (co)polymer is particularly suitable when producing a cycloolefin resin base material by a solution film forming method.

First, the cycloolefin monomer represented by the general formula (A-1) will be described.

R ¹ to R ⁴ in the general formula (A-1) each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms, or a polar group. However, excluding the case where all R ¹ to R ⁴ become hydrogen atoms, it is considered that there is no case where R ¹ and R ² become hydrogen atoms at the same time, or R ³ and R ⁴ become hydrogen atoms at the same time.

The halogen atom is not particularly limited, but a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are preferred. The hydrocarbon group having 1 to 30 carbon atoms is not particularly limited, and an alkyl group having 1 to 30 carbon atoms is preferred. The polar group is not particularly limited. A carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amine group, an amide group, a cyano group, a group in which these groups are bonded via a linking group such as a methylene group, It is preferable to use a polar divalent organic group such as a carbonyl group, an ether group, a silyl ether group, a thioether group, an imine group, etc. as a linking group and a bonded hydrocarbon group. Among these, carboxyl group, hydroxyl group, alkoxycarbonyl group or allyloxycarbonyl group is also preferred. In addition, from the viewpoint of ensuring solubility during film formation from a solution, an alkoxycarbonyl group or an allyloxycarbonyl group is more preferred.

From the viewpoint of ensuring the solubility of the cycloolefin resin during film formation from a solution, it is preferred that at least one of R ¹ to R ⁴ be a polar group.

p in general formula (A-1) represents an integer from 0 to 2. From the viewpoint of improving the heat resistance of the film, p is preferably 1 to 2. This is because if p is 1 to 2, the volume of the resin obtained is likely to increase, and the glass transition temperature is likely to increase.

Next, the cycloolefin monomer represented by the general formula (A-2) will be described.

R ⁵ in the general formula (A-2) represents a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkylsilyl group having an alkyl group having 1 to 5 carbon atoms. Among them, R ⁵ is preferably a hydrocarbon group with 1 to 3 carbon atoms.

R ⁶ in the general formula (A-2) represents a polar group or a halogen atom. The polar group is not particularly limited, but is preferably a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amine group, an amide group, or a cyano group. The halogen atom is not particularly limited, but a fluorine atom, a chlorine atom, a bromine atom or an iodine atom is preferred. Among these, R ⁶ is preferably a polar group, and preferably a carboxyl group, a hydroxyl group, an alkoxycarbonyl group or an allyloxycarbonyl group. In addition, from the viewpoint of ensuring solubility during film formation from a solution, an alkoxycarbonyl group or an allyloxycarbonyl group is more preferred.

By using a cycloolefin monomer represented by the general formula (A-2), the symmetry of the molecule becomes lower and the diffusion movement of the resin when the solvent evaporates is easily promoted.

In general formula (A-2), p represents an integer from 0 to 2.

Specific examples of the structures of general formulas (A-1) and (A-2) are shown below.

Furthermore, by increasing the proportion of the alicyclic structure in the cycloolefin resin, the refractive index can be further reduced.

The cycloolefin monomer constituting the cycloolefin resin (that is, the cycloolefin monomer constituting the cycloolefin resin) may be used alone, or two or more types may be used in combination.

The cycloolefin resin may be a copolymer of a cycloolefin monomer and a monomer other than the cycloolefin monomer, or a hydrogenated product thereof. The monomers other than the cycloolefin monomer constituting the cycloolefin resin (that is, the monomers other than the cycloolefin monomer constituting the cycloolefin resin) may be used individually by one type, or two or more types may be used in combination.

As described above, the cycloolefin resin is preferably a (co)polymer (the (co)polymer may be in a hydrogenated state) containing a structural unit derived from a monomer containing a norbornene structure. Furthermore, the cycloolefin resin may be a copolymer including a structural unit derived from a monomer containing a norbornene structure and a structural unit derived from a monomer other than a monomer containing a norbornene structure (the copolymer). It can also be in the hydride state). Here, the other monomer that can be copolymerized with the monomer containing a norbornene structure may be a cycloolefin monomer or a monomer other than the cycloolefin monomer. There are no particular limitations on other monomers that can be copolymerized with monomers containing a norbornene structure. Examples thereof include norbornene structure-containing monomers that can be ring-opening copolymerized with monomers containing a norbornene structure. Monomers other than monomers, or monomers other than monomers containing norbornene structure that can be added and copolymerized with monomers containing norbornene structure.

The monomer other than the monomer containing the norbornene structure that can be subjected to ring-opening copolymerization with the monomer containing the norbornene structure is not particularly limited, and examples thereof include cyclobutene, cyclopentene, and cyclohexane. Monomers other than monomers containing norbornene structure such as olefin, cycloheptene, cyclooctene, dicyclopentadiene, and these derivatives.

The monomer other than the monomer containing the norbornene structure that can be added-copolymerized with the monomer containing the norbornene structure is not particularly limited. Examples thereof include unsaturated double bond-containing compounds and vinyl compounds. Cyclic hydrocarbon compounds, (meth)acrylate compounds, etc.

The compound containing an unsaturated double bond (excluding vinyl cyclic hydrocarbon compounds and (meth)acrylate compounds described below) is not particularly limited, and examples thereof include carbon atoms such as ethylene, propylene, and 1-butene. α-olefins and their derivatives with a number of 2 to 20 (preferably 2 to 12, more preferably 2 to 8), or 1,4-hexadiene, 4-methyl-1,4-hexadiene, Non-conjugated dienes such as 5-methyl-1,4-hexadiene, etc. Among these, compounds containing unsaturated double bonds are also preferred. As the compound containing an unsaturated double bond, an α-olefin having a carbon number of 2 to 20 (preferably 2 to 12, more preferably 2 to 8) is preferred, and ethylene is even more preferred. Furthermore, as the unsaturated double bond-containing compound, an unsaturated double bond-containing compound having a hydroxyl group is preferred, and a monomer having a structure represented by the following formula (M1) is preferred.

Here, the above-mentioned R ₁₁ is an organic group. The organic group of R ₁₁ is not particularly limited, and examples thereof include electron-donating groups such as alkyl groups and methoxy groups. Among these, the above-mentioned R ₁₁ is preferably an alkyl group, preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and particularly preferably a butyl group.

The vinyl cyclic hydrocarbon compound is not particularly limited, and examples thereof include vinyl cyclopentene such as 4-vinylcyclopentene, 2-methyl-4-isopropenylcyclopentene and derivatives thereof. Ethylene monomers, etc.

The (meth)acrylate compound is not particularly limited, and examples thereof include methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, and the like. Alkyl (meth)acrylate with 1 to 20 carbon atoms and its derivatives, etc. Among these, (meth)acrylate compounds having a hydroxyl group are also preferred. The (meth)acrylate compound having a hydroxyl group is not particularly limited, and examples thereof include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxypropyl (meth)acrylate. Butyl (meth)acrylate, 3-hydroxypropane-1,2-diyl di(meth)acrylate, glycerol mono(meth)acrylate, diglycerol mono(meth)acrylate , diglycerol tri(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol mono(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate Acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, sorbitol di(meth)acrylate Acrylate, sorbitol tri(meth)acrylate, sorbitol tetra(meth)acrylate, sorbitol penta(meth)acrylate, sorbitol mono(meth)acrylate diglycerol di(meth)acrylate ) acrylate, isocyanuric acid EO denatured diacrylate, etc.

Among these, (meth)acrylate compounds having a hydroxyl group are also preferred, and 2-hydroxyethyl (meth)acrylate (alias: (meth)acrylic acid 2-hydroxyethyl) is preferred. 2-hydroxyethyl acrylate (alias: 2-hydroxyethyl acrylate) is more preferred.

In a copolymer containing a structural unit derived from a monomer containing a norbornene structure and a structural unit derived from a monomer other than a monomer containing a norbornene structure, a unit other than a monomer containing a norbornene structure is used. One type of the system may be used alone, or two or more types may be used in combination.

Preferred cycloolefin resins include, for example, tricyclo[4.3.0.1 ^2,5 ]dec-3-ene and tetracyclo[4.4.0.1 ^{2,5.1 7,10} ]dode-3-ene. (common name: tetracyclododecene), and the hydrogenated product of the copolymer of the monomer of 1,3-dimethyldodehydrocyclopenta[a]indene, including bicyclo[2.2.1]hept-2-ene (Common name: copolymer of norbornene) and ethylene monomer, etc. Among these, examples include tricyclo[4.3.0.1 ^2,5 ]dec-3-ene and tetracyclo[4.4.0.1 ^{2,5.1 7,10} ]dodec-3-ene (conventionally Name: tetracyclododecene), the hydrogenated product of the copolymer of 1,3-dimethyldodecahydrocyclopenta[a]indene, and 2-hydroxyethyl acrylate, bicyclo[2.2.1]hept-2- Copolymers of olefin (common name: norbornene) and ethylene are preferred examples.

The mass ratio of the monomers having an alicyclic structure relative to the total mass of the monomers having an alicyclic structure and the monomers not having an alicyclic structure used to constitute the cycloolefin resin is not particularly limited. However, the ratio is preferably 30 to 50% by mass. If it is within this range, the refractive index of the cycloolefin resin base material will easily become an appropriate value. The results show that unevenness will be further reduced.

With respect to a copolymer containing a structural unit derived from a monomer containing a norbornene structure (the copolymer may be in a hydride state), a monomer containing a norbornene structure is used, and a monomer containing a norbornene structure is used. There is no particular restriction on the mass ratio of the monomer containing the norbornene structure to the total mass of the monomers other than the monomer. However, the ratio is preferably 30 to 50% by mass. If it is within this range, the refractive index of the cycloolefin resin base material will easily become an appropriate value. The results show that unevenness will be further reduced.

The weight average molecular weight (Mw) of the cycloolefin resin is not particularly limited, but it is preferably 30,000 or more, more preferably 35,000 or more, and more preferably 40,000 or more. Moreover, the weight average molecular weight (Mw) of the cycloolefin resin is preferably 300,000 or less, more preferably 250,000 or less, and more preferably 150,000 or less. If it is within these ranges, the heat resistance, water resistance, chemical resistance, mechanical properties and formability of the cycloolefin resin as a film will become better.

In addition, the dispersion degree (Mw/Mn) of the cycloolefin resin is not particularly limited, but it is preferably 1.2 or more, more preferably 1.5 or more, and more preferably 1.8 or more. Moreover, the dispersion degree (Mw/Mn) of the cycloolefin resin is preferably 3.5 or less, more preferably 3.0 or less, and more preferably 2.7 or less.

The number average molecular weight (Mn) or the weight average molecular weight (Mw) can be measured in terms of polystyrene by gel permeation chromatography (GPC).

The glass transition temperature (Tg) of the cycloolefin resin is not particularly limited, but it is preferably 100°C or higher, more preferably 110°C or higher, and more preferably 120°C or higher. If it is within this range, it becomes less likely to cause deformation caused by use under high temperature conditions or secondary processing such as coating and printing. In addition, the glass transition temperature (Tg) of the cycloolefin resin is preferably 190°C or lower, more preferably 180°C or lower, and more preferably 170°C or lower. If it is within these ranges, molding processing becomes easier, and the possibility of resin deterioration due to heat during molding processing becomes even lower. The Tg system of cycloolefin resin can be measured according to JIS K 7121-1987.

As the cycloolefin resin, commercially available products or synthetic products can be used. Examples of commercially available products are not particularly limited and include, for example, ARTON (registered trademark, the same below) G (for example, ARTON G7810), ARTON F, ARTON manufactured by JSR Co., Ltd. R, and Yaton RX, etc.

The synthesis method of the cycloolefin resin is not particularly limited, and a known method can be used. For example, the ring-opening polymer containing a monomer with a norbornene structure is not particularly limited, and can be produced, for example, by polymerizing or copolymerizing the monomer in the presence of a ring-opening polymerization catalyst. Moreover, the addition polymer containing the monomer of norbornene structure is not specifically limited, For example, it can be produced by polymerizing or copolymerizing a monomer in the presence of an addition polymerization catalyst. Moreover, the hydride of the above-mentioned ring-opening polymer and addition polymer is not particularly limited. For example, it can be prepared by adding a solution of a ring-opening polymer and an addition polymer to a transition metal containing nickel, palladium, etc. It is produced by hydrogenating the carbon-carbon unsaturated bond in the presence of a hydrogenation catalyst, preferably by hydrogenating 90% or more. In addition, as a synthesis method of the cycloolefin resin, a method based on the method described in Japanese Patent Application Publication No. 2010-235719 or Japanese Patent Application Publication No. 2018-55044 can also be used, and the type, amount, ratio, etc. of the monomers can be appropriately changed as necessary. or other methods of synthesizing the types, amounts and ratios of ingredients used.

One type of cycloolefin resin may be used alone, or two or more types may be used in combination.

The content of the cycloolefin resin in the cycloolefin resin base material is not particularly limited, but it is preferably 50 mass% or more, more preferably 70 mass% or more, and more preferably 90 mass% or more. If it is within the above range, the handleability of the film will become even better. Moreover, the content of the cycloolefin resin in the cycloolefin resin base material is preferably 100 mass% or less, more preferably 99.9 mass% or less, and more preferably 99.5 mass% or less. If it is within the above range, the added amount of components other than the cycloolefin resin can be increased, thereby further enhancing the effect of the present invention and making it easier to provide other desired functions.

The cycloolefin resin base material preferably contains particles. That is, the cycloolefin resin base material preferably contains at least one type of particles. The particle system achieves a function of further reducing display unevenness. Hereinafter, the particles contained in the cycloolefin resin base material are also simply referred to as "base material particles".

The substrate particles are not particularly limited, and examples thereof include organic particles, inorganic particles, organic-inorganic composite particles, and the like.

The inorganic particles are not particularly limited, and examples thereof include silicon dioxide (silica), titanium dioxide, lower titanium oxide, magnesium oxide, tin oxide, indium oxide, antimony oxide, alumina, zirconium dioxide, doped Tin oxide doped with antimony, fluorine or phosphorus, inorganic oxides such as indium oxide doped with antimony, tin or fluorine, or calcium carbonate, magnesium carbonate, barium sulfate, strontium sulfate, talc, clay, fired kaolin, Calculate inorganic substances such as calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium silicate, etc. One type of inorganic material may be used alone, or two or more types may be used in combination. Among them, particles composed of the above-mentioned inorganic materials or their combinations are also preferred, and alumina (alumina particles, particulate alumina) is preferred.

The organic particles are not particularly limited, and examples thereof include acrylic resins such as poly(meth)acrylate and polymeth(meth)acrylate, styrene resins such as polystyrene, and poly(meth)acrylate. Acrylonitrile resins such as acrylonitrile, cellulose resins such as cellulose acetate, cellulose acetate propionate, silicone resins, fluororesins, and cross-linked products thereof, etc. The organic material system may be used individually by 1 type, or may use 2 or more types together. Among them, particles composed of the above-mentioned organic materials or their combinations, or their cross-linked products are also preferred.

The organic-inorganic composite particles are not particularly limited, and examples thereof include multilayer particles including a core layer composed of one of the above-mentioned inorganic materials and the above-mentioned organic materials, and a shell layer composed of the other one. . The inorganic material or the organic material may be used individually by 1 type, or may use 2 or more types together.

The base particles may also be surface-treated particles (surface-treated particles). When surface treatment is performed, examples of materials used for surface treatment include dissimilar inorganic oxides such as silicon oxide and zirconium oxide, metal hydroxides such as aluminum hydroxide, and organic acids such as stearic acid. Hydrolyzable organosilicon compounds, etc. Each surface treatment system may be used individually by 1 type, or may use 2 or more types together. The surface-treated particles are not particularly limited, and examples thereof include particles in which the surface of particles composed of the above-mentioned inorganic material is treated with a hydrolyzable organosilicon compound. Here, the particles to which such treatment is applied are generally those in which the surface of the particles made of an inorganic material is modified with a hydrolyzate of an organosilicon compound.

The surface treatment method and the type of surface treatment particles are not particularly limited, and known surface treatment methods and known surface treatment particles can be used. For example, the organosilicon compound modification method and organosilicon compound-modified particles described in paragraphs "0105" to "0128" of Japanese Patent Application Laid-Open No. 2016-157068 can be used.

The average primary particle diameter of the base material particles is not particularly limited, but is preferably 1 nm or more. If the brightness is within the above range, uneven brightness between display devices will be reduced, and the variation in display quality between display devices will be further reduced. In addition, the average primary particle diameter of the base material particles is not particularly limited, but is preferably 100 nm or less. If it is within the above range, the transparency of the film will be further improved. In addition, the average primary particle diameter of the base material particles can be measured by transmission electron microscopy (TEM) (H-7650 manufactured by Hitachi High-Technology Co., Ltd.).

The average secondary particle diameter of the base material particles is not particularly limited, but is preferably 10 nm or more. If the brightness is within the above range, uneven brightness between display devices will be reduced, and the variation in display quality between display devices will be further reduced. In addition, the average secondary particle diameter of the base material particles is not particularly limited, but is preferably 300 nm or less. If it is within the above range, the transparency of the film will be further improved. The average secondary particle diameter of the base material particles can be determined by directly measuring the size of the secondary particles from an electron micrograph of the layer (cycloolefin resin base material). Specifically, this method uses transmission electron microscopy (TEM) (H-7650 manufactured by Hitachi High-tech Co., Ltd.) to measure particle images and determine the equivalent of 100 randomly selected secondary particles. The average diameter of circles of equal area, and this value is taken as the average secondary particle diameter.

As the base material particles, commercially available products or synthetic products may be used. Commercially available products are not particularly limited, and examples thereof include R972V and R812 manufactured by Japan Aerosil Co., Ltd., alumina nanoparticles manufactured by EM JAPAN Co., Ltd., and the like.

One type of base material particles may be used alone, or two or more types may be used in combination.

The content of the base particles in the cycloolefin resin base material is not particularly limited, but it is preferably 0.1% by mass or more relative to the total mass of the cycloolefin resin base material. If it is within the above range, the adjustment of the refractive index becomes easier. Furthermore, the content of the base material particles in the cycloolefin resin base material is preferably 10% by mass or less relative to the total mass of the cycloolefin resin base material. If it is within the above range, the transparency of the film will be further improved.

In one embodiment of the present invention, the cycloolefin resin base material does not need to contain base material particles.

The cycloolefin resin base material may further contain other components than those described above as long as the effects of the present invention are not impaired. The other components are not particularly limited, and examples thereof include components used in the field of known optical films or in the field of known functional layers for optical applications. Specific examples include thermoplastic resins other than cycloolefin resins (excluding organic particles of the above-mentioned base material particles), retardation adjusters, wavelength dispersion adjusters, plasticizers, ultraviolet absorbers, antioxidants, and hydrogen bonding agents. solvents, ionic surfactants, etc., but are not limited by these.

In one embodiment of the present invention, the thickness of the cycloolefin resin base material is not particularly limited, but is preferably 10 μm or more. If it is within this range, the film has good operability. In addition, the thickness of the cycloolefin resin base material is preferably 60 μm or less. If it is within this range, it can also be applied to a flexible device.

In one embodiment of the present invention, the refractive index of the cycloolefin resin base material is not particularly limited, but is preferably 1.500 or more, and more preferably 1.525 or more. In addition, the refractive index of the cycloolefin resin base material is preferably 1.535 or less. If it is within these ranges, the refractive index difference between the optical film containing the cycloolefin resin base material and the polarizer becomes more likely to satisfy the equation (1) described below. It is particularly preferred if the refractive index at the nD:D line (589nm) at 25°C satisfies the above range. The refractive index can be measured with a multi-wavelength Abbe refractometer (trade name: DR-M2, manufactured by ATAGO Co., Ltd.).

・Functional layer The optical film preferably has an organic functional layer in addition to the above-mentioned cycloolefin resin base material. That is, in at least one of the polarizing plates included in the display device according to one embodiment of the present invention, at least one of the optical films included in the polarizing plate is composed of a base material containing a cycloolefin resin and a functional film. Layer is better. By using an optical film with a base material and a functional layer, desired functions can be provided and display unevenness can be further reduced. This reason is as described in the above-mentioned speculation mechanism. It is considered that when the display device of the present invention deliberately scatters the light emitted from the display device slightly in order to eliminate the light interference between the pixel grids, the functional layer will This is due to the effect of making the scattering more appropriate.

The optical film system may have only one functional layer, or may have two or more functional layers. In addition, the functional layer may be provided on one side of the above-mentioned base material containing the cycloolefin resin, or may be provided on both sides, but it is preferably provided on one side.

Among the optical films included in the polarizing plate, it is preferred that at least one of the optical films disposed on one side of the polarizer further includes a functional layer in addition to a base material containing an olefin resin. Furthermore, it is preferable that all the optical films disposed on one side of the polarizer have a base material and a functional layer containing a cycloolefin resin. At this time, one or more optical films may be disposed on the other side of the polarizer, or no optical film may be disposed.

Furthermore, among the optical films included in the polarizing plate, it is particularly preferred that one optical film is disposed on one side of the polarizer, and that the optical film further includes a functional layer in addition to the base material of the cycloolefin resin. At this time, one or more optical films may be disposed on the other side of the polarizer, or no optical film may be disposed. Among them, it is also preferable to arrange another optical film described below on the other side of the polarizer.

The functional layer is not particularly limited, and examples thereof include functional layers used for optical applications. Specific examples include anti-clogging layer, release layer, easy-adhesion layer, anti-static layer, hard coat layer, anti-reflection layer, anti-glare layer, anti-fouling layer, barrier layer, buffer layer, and slipability layer. layer, adhesive layer, etc., but are not limited to these. Among them, a functional layer other than an adhesive layer is preferred, an easily adhesive layer or a hard coat layer is more preferred, and an easily adhesive layer is more preferred.

In addition, the functional layer is preferably a hardened layer.

The functional layer is not particularly limited. For example, a matrix resin including urethane resin, acrylic resin, epoxy resin, polyvinyl acetal resin, etc. is preferably used. For example, when the functional layer is an easily adhesive layer, the easily adhesive layer preferably contains a urethane resin. For example, when the functional layer is a hard coat layer, the hard coat layer preferably contains an acrylic resin.

The functional layer containing a urethane resin is not particularly limited, and examples thereof include a layer (layer of coating liquid) containing a polyurethane precursor or a polyurethane coating liquid. The layer obtained by hardening, etc.

The urethane resin is not particularly limited, and examples thereof include adding polyurethane itself as a raw material of the coating liquid, and adding the polyurethane resin through a curing reaction with isocyanate or its derivatives and alcohol or its derivatives. The polyurethane product obtained, and the polyurethane product obtained through the hardening reaction of the urethane prepolymer, etc. Therefore, the urethane resin is preferably polyurethane or its cross-linked product.

The polyurethane itself, the urethane prepolymer and the polyurethane product are not particularly limited, and examples include polyurethane having an average of two or more hydroxyl groups per molecule. Alcohol component, polyurethane obtained by reacting with a polyisocyanate component having an average of 2 or more isocyanate groups per molecule, etc.

The polyol component is not particularly limited, and examples thereof include (1) aliphatic polyester polyol, (2) polyether polyol, (3) polycarbonate polyol, and (4) polyester ether polyol. , and (5) polyethylene terephthalate polyol, etc.

(1) The aliphatic polyester polyol is not particularly limited, and examples thereof include reactants obtained by the reaction of an aliphatic polyol and an aliphatic polybasic acid. The aliphatic polyol is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, glycerin, trimethylolpropane, and the like. One type of aliphatic polyol may be used alone, or two or more types may be used in combination at an arbitrary ratio. The aliphatic polybasic acid is not particularly limited, and examples thereof include polyvalent carboxylic acids and their anhydrides. The polyvalent carboxylic acid is not particularly limited, and examples thereof include adipic acid, succinic acid, sebacic acid, glutaric acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, and the like. Dicarboxylic acid, or tricarboxylic acid such as trimellitic acid, etc. One type of polybasic acid may be used alone, or two or more types may be used in combination at an arbitrary ratio.

The polyether polyol (2) is not particularly limited, and examples thereof include poly(oxypropylene ether) polyol, poly(oxyethylene-propylene ether) polyol, and the like.

The polycarbonate polyol (3) is not particularly limited, and examples thereof include _the formula HO-R-(OC(O)-OR) The saturated fatty acid polyol residue. In addition, X represents the number of structural units of the molecule, usually an integer from 5 to 50), etc. Such polycarbonate polyol is not particularly limited, and can be obtained, for example, by a transesterification method in which a saturated aliphatic polyol and a substituted carbonate are reacted under conditions in which hydroxyl groups are excessive. For example, it can be obtained by reacting a saturated aliphatic polyol with phosgene, or by reacting it with a saturated aliphatic polyol later if necessary. At this time, the substituted carbonate is not particularly limited, and examples thereof include diethyl carbonate, diphenyl carbonate, and the like. Moreover, these systems may be used individually by 1 type, or may use 2 or more types together in arbitrary ratios.

(4) The polyester ether polyol is not particularly limited, and examples thereof include a reactant obtained by reacting a polyol compound containing an ether group with a polyvalent carboxylic acid or its anhydride. The polyol compound containing an ether group is not particularly limited, and examples thereof include the aforementioned (2) polyether polyol, diethylene glycol, and the like. The polyol compound containing an ether group may be used individually by 1 type, or may use 2 or more types together in arbitrary ratios. In addition, the polyvalent carboxylic acid or its anhydride is not particularly limited, and examples thereof include the compounds exemplified in the description of (1) aliphatic polyester polyol. A polyvalent carboxylic acid or its anhydride may be used individually by 1 type, or 2 or more types may be used together in arbitrary ratios. Specific examples of the polyester ether polyol include polybutylene glycol-adipic acid condensate and the like.

The polyethylene terephthalate polyol (5) is not particularly limited, and for example, a known polyethylene terephthalate polyol can be used.

The polyol component may be used individually by 1 type, or may use 2 or more types together in arbitrary ratios.

The polyisocyanate component is not particularly limited, and examples thereof include aliphatic polyisocyanate compounds having two or more isocyanate groups per molecule, alicyclic polyisocyanate compounds, and aromatic polyisocyanate compounds.

The aliphatic polyisocyanate compound is not particularly limited, and examples thereof include hexamethylene diisocyanate, 2,2,4-trimethylhexane diisocyanate, hexane diisocyanate (HDI), etc. 1~12 aliphatic diisocyanates, etc.

The alicyclic polyisocyanate compound is not particularly limited, and examples thereof include 1,4-cyclohexane diisocyanate, methylcyclohexyl diisocyanate, isophorone diisocyanate (IPDI), and dicyclohexylmethane. Alicyclic diisocyanate with 4 to 18 carbon atoms such as diisocyanate (HMDI), etc.

The aromatic polyisocyanate compound is not particularly limited, and examples thereof include aromatic diisocyanates such as toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate, and styryldiisocyanate.

The polyisocyanate component can be used individually by 1 type, or can use 2 or more types together in arbitrary ratios.

Among them, the polyurethane itself, the urethane prepolymer, and the polyurethane product are respectively polycarbonate-based polyurethane or polyester-ether. Polyurethane is preferred. Polycarbonate-based polyurethane refers to a polyurethane having a carbonate skeleton in the molecular structure of the polyurethane. Examples include polyurethane produced from polycarbonate polyol and polyisocyanate components. Moreover, the polyester-ether polyurethane refers to a polyurethane having an ester bond and an ether bond in the molecular structure of the polyurethane. Examples thereof include polyurethane produced from polyester ether polyol and polyisocyanate components.

The urethane prepolymer may include unreacted hydroxyl groups remaining after the reaction of the polyol component and the polyisocyanate component. The hydroxyl group can be used as a polar group capable of performing a cross-linking reaction with the functional group in the cross-linking agent.

The urethane prepolymer is preferably one that can be cross-linked by a cross-linking agent.

The urethane prepolymer preferably contains a polar group in order to achieve reaction with the cross-linking agent. The polar group is not particularly limited, and examples thereof include a hydroxymethyl group, a carboxyl group, a carbonyloxycarbonyl group, an epoxy group, a hydroxyl group, an oxy group, an ester group, a silicon alcohol group, a silicon group, an amine group, and a nitrile group. Sulfonic acid group, etc. Among these, a hydroxymethyl group, a hydroxyl group, a carboxyl group and an amino group are also preferred, a hydroxyl group or a carboxyl group is more preferred, and a carboxyl group is more preferred. The amount of polar groups in the polyurethane is not particularly limited, but is preferably 0.0001 equivalent/1kg or more, more preferably 0.001 equivalent/1kg or more. In addition, the amount of polar groups in the polyurethane is preferably 1 equivalent/1kg or less.

As polyurethane itself or the raw material of urethane resin, isocyanate or its derivatives, alcohol or its derivatives, urethane prepolymers, and urethane prepolymers The raw materials used for the production may be commercially available products or synthetic products. There is no particular limitation on the commercially available product, and for example, a commercially available aqueous emulsion of aqueous urethane resin can be used. Water-based urethane resin refers to a composition containing polyurethane and water, usually polyurethane and optional components dispersed in water as necessary. The water-based urethane resin is not particularly limited, and examples thereof include the "Adeka Bontighter (registered trademark)" series manufactured by ADEKA Co., Ltd. and the "Olester (registered trademark)" series manufactured by Mitsui Chemicals Co., Ltd. , "Vondic (registered trademark)" series made by DIC Co., Ltd., "Hydran (registered trademark) (WLS201, WLS202, etc.)" series, "Impranil" series made by Bayer Co., Ltd., "Poiz (registered trademark) made by Kao Co., Ltd. Trademark)" series, "Sanplen (registered trademark)" series made by Sanyo Chemical Industry Co., Ltd., "SuperFlex (registered trademark)" series made by Daiichi Industrial Pharmaceutical Co., Ltd., "NEOREZ" made by Kusumoto Chemical Co., Ltd. series, the "Sancure" series produced by Lubrizol Company, etc.

Cross-linking agents may also be used in the formation of urethane resins. As the cross-linking agent, there are no particular restrictions and publicly known ones can be used. Examples include epoxy compounds, carbodiimide compounds, oxazoline compounds, isocyanate compounds, and the like. Specific examples of these include the cross-linking agents described in paragraphs "0075" to "0094" of Japanese Patent Application Laid-Open No. 2016-79210, and the like. One type of cross-linking agent may be used alone, or two or more types may be used in combination at an arbitrary ratio.

Hardening accelerators may also be used in the formation of urethane resins. As the hardening accelerator, there are no particular restrictions, and known ones can be used. Examples include tertiary amine compounds (excluding compounds having a 2,2,6,6-tetramethylpiperidinyl group having a tertiary amine at the 4-position), boron azide trifluoride compounds, and the like. One type of hardening accelerator may be used alone, or two or more types may be used in combination at an arbitrary ratio.

Hardening aids may also be used in the formation of urethane resins. As the hardening auxiliary agent, there are no particular restrictions, and well-known ones can be used. Examples include oximes and nitroso-based hardening aids such as quinonedioxime, benzoquinonedioxime, and p-nitrosophenol; and maleides such as N,N-m-phenylbismaleimide. Imine-based hardening additives; allyl-based hardening additives such as diallyl phthalate, triallyl cyanurate, triallyl isocycyanurate, etc.; ethylene glycol dimethyl Methacrylate-based hardening aids such as acrylates and trimethylolpropane trimethacrylate; vinyl-based hardening aids such as vinyltoluene, ethylvinylbenzene, divinylbenzene, etc. One type of hardening auxiliary agent may be used alone, or two or more types may be used in combination at an arbitrary ratio.

One type of urethane resin may be used alone, or two or more types may be used in combination.

Acrylic resin refers to a resin containing a structural unit derived from a (meth)acrylate compound. The acrylic resin is not particularly limited, but an acrylic resin cured by active energy rays is preferred, and an acrylic resin cured by ultraviolet rays is preferred. An acrylic resin obtained by active energy ray curing can be obtained by irradiating an active energy ray curable (meth)acrylate compound or a mixture of the compound and a compound copolymerizable with the active energy ray to harden the compound. In addition, an acrylic resin obtained by ultraviolet curing can be obtained by irradiating a mixture of an ultraviolet curable (meth)acrylate compound, the compound, and a compound copolymerizable with the ultraviolet curable (meth)acrylate compound with ultraviolet rays to cause curing.

The curable (meth)acrylate compound constituting the acrylic resin is not particularly limited, and examples thereof include well-known active energy ray-curable (meth)acrylic compounds that can be used as materials for functional layers used in optical applications. ester compounds, or well-known ultraviolet curable (meth)acrylate compounds, etc. Among these, known compounds that can be used as materials for the functional layer, especially the hard coat layer, are preferred. Such compounds are not particularly limited, and examples thereof include monofunctional (meth)acrylate compounds, polyfunctional (meth)acrylate compounds, and combinations thereof.

There are no particular restrictions on the monofunctional (meth)acrylate compound, and publicly known ones can be used. Examples include (meth)acrylate, methyl(meth)acrylate, dicyclopentenyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, dicyclopentenyloxyethyl(meth)acrylate, and dicyclopentenyloxyethyl(meth)acrylate. Cyclopentyl (meth)acrylate, etc.

The polyfunctional (meth)acrylate compound is not particularly limited, and known compounds can be used. For example, trimethylolpropane triacrylate, bistrimethylolpropane tetraacrylate, isocyanuric acid EO denatured triacrylate, pentaerythritol triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate can be used , dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, ethylene oxide adduct of dipentaerythritol hexaacrylate, the H of ethylene oxide in the adduct is substituted by fluorine, pentaerythritol tetraacrylate, pentaerythritol tetraacrylate The ethylene oxide adduct of acrylate, the H of ethylene oxide in the adduct is substituted by fluorine, etc.

Moreover, as a monofunctional (meth)acrylate compound or a polyfunctional (meth)acrylate compound, a (meth)acrylate compound which has an aromatic ring can also be used. By using these compounds, the refractive index of the functional layer can be increased. The (meth)acrylate compound having an aromatic ring is not particularly limited, and examples thereof include benzyl acrylate or a monofunctional (meth)acrylate compound represented by any one of the following general formulas (i) to (iv) Meth)acrylate compounds, etc. Among these, benzyl acrylate is also preferred.

In the above general formulas (i) to (iv), R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, an alkyl group with 1 to 3 carbon atoms or an aromatic ring, and n represents a positive number from 0 to 2.

The acrylic resin preferably contains urethane acrylate resin. The reason for this is that the adhesion between the base material and the functional layer on the refractive index surface is good, and peeling at the interface, that is, a difference in refractive index, is unlikely to occur even under durable use, so it is preferable. Urethane acrylate resin means an acrylic resin containing a structural unit derived from a urethane (meth)acrylate compound.

The urethane (meth)acrylate compound as the curable (meth)acrylate compound is not particularly limited, and examples thereof include the poly(meth)acrylate compound described above having the above-mentioned urethane resin in the molecule. The skeleton structure of urethane prepolymer and (meth)acryloxy compounds, etc. Furthermore, the urethane (meth)acrylate compound may be an aliphatic urethane (meth)acrylate compound or an aromatic urethane (meth)acrylate compound. .

Among the curable urethane (meth)acrylate compounds, polyether urethane (meth)acrylate is particularly preferred.

The polyether urethane (meth)acrylate is not particularly limited, and examples thereof include (ua1) a polyol having a polyether polyol skeleton, (ua2) an isocyanate compound, and (ua3) Obtained from the reaction of (meth)acrylate with hydroxyl group.

The polyol (ua1) has a terminal hydroxyl group for forming a urethane bond with the isocyanate compound (ua2). When a bifunctional urethane (meth)acrylate is used, the polyol (ua1) has one hydroxyl group at both ends of the skeleton. Furthermore, the polyol (ua1) must have a polyether polyol skeleton. Among them, from the viewpoint of improving adhesion, polypropylene polyol (polypropylene glycol) is preferred.

The number average molecular weight of the polypropylene polyol as the polyether polyol (ua1) is preferably 1,000 to 10,000, and more preferably 1,500 to 5,000. If the number average molecular weight is within this range, an adhesive composition with excellent adhesiveness can be produced. In addition, the number average molecular weight is represented by the value measured by gel permeation chromatography (GPC method) (polystyrene conversion).

When using bifunctional polyether urethane (meth)acrylate, the isocyanate compound (ua2) has two isocyanate groups.

As the isocyanate compound (ua2), a known compound can be used. Examples include toluene diisocyanate, hydrogenated toluene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, Xylylene diisocyanate (Xylylene diisocyanate), paraphenylene diisocyanate diisocyanate) and other well-known persons. Only one type of these isocyanate compounds (ua2) may be used alone, or two or more types may be used in combination.

The (meth)acrylate (ua3) having a hydroxyl group has at least one hydroxyl group in order to form a urethane bond.

There is no particular restriction on the (meth)acrylate (ua3), and any known compound can be used without limitation. Examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, butylene glycol mono(meth)acrylate, and 2-hydroxyethyl (meth)acrylate. Caprolactone denaturation of esters, glycidyl di(meth)acrylate, and pentaerythritol tri(meth)acrylate. Only one type of these (meth)acrylate (ua3) may be used alone, or two or more types may be used in combination.

Polyether urethane (meth)acrylate can be produced suitably by conventionally known methods. As a general production method, the polyether polyol (ua1) and the isocyanate compound (ua2) are heated at 70 to 80° C. while stirring for 4 to 6 hours. Thereafter, polyether urethane (meth)acrylic acid is synthesized by adding (meth)acrylate (ua3) with a hydroxyl group, heating at 70~80°C while stirring for 4~6 hours ester. At this time, the input amounts of the polyether polyol (ua1), the isocyanate compound (ua2), and the (meth)acrylate having a hydroxyl group (ua3) are not particularly limited. When the total mass of these is 100% by mass, Preferable are 62.0~96.9% by mass, 2.5~25.2% by mass, and 0.4~11.7% by mass respectively.

In addition, the number average molecular weight of the polyether urethane (meth)acrylate is not particularly limited, but is preferably 2,000 to 50,000, and more preferably 3,000 to 15,000. In addition, the number average molecular weight is represented by the value measured by gel permeation chromatography (GPC method) (polystyrene conversion).

The number of functions of the urethane (meth)acrylate compound is not particularly limited. For example, it may be less than trifunctional or less, or it may be trifunctional or more. Here, if it has six or more functions, it is particularly suitable for the formation of a hard coat layer.

As the curable (meth)acrylate compound, a commercial product or a synthetic product may be used. For example, FANCRYL series FA-511AS, FA-512AS, FA-513AS, FA-BZA, FA-314A, FA-318AS, FA-129AS, FA-P240A, FA-P270A manufactured by Showa Denko Materials Co., Ltd. , FA-324A, FA-731A, FA-512M, FA-512MT, FA-513M, FA-711MM, FA-712HM, FA-400M(100), FA-BZM, FA-124M, FA-125M, FA- 220M, FA-321M and FA-023M, etc. In addition, commercially available products of the urethane (meth)acrylate compound as the curable (meth)acrylate compound are not particularly limited. Examples of bifunctional aliphatic urethane (meth)acrylate compounds include EBECRYL (registered trademark) 230, 270, 280, 284, 4683, 4858, 8307, and 8402 manufactured by DAICEL-ALLNEX. , 8411, 8413, 8804, 8807, 9270 and 8800, as well as KRM7735, KRM8961 and KRM8191, etc. Examples of the 3- to 4-functional aliphatic urethane (meth)acrylate compound include EBECRYL (registered trademark) 294, 4220, 4513, 4738, 4740, 8311, and 9260 manufactured by DAICEL-ALLNEX. , 8701, 4265, 4587, 4666, 4680, 8210 and 8405, as well as KRM8667, KRM8296 and KRM8528, etc. Examples of the hexafunctional or higher aliphatic urethane (meth)acrylate compound include EBECRYL (registered trademark) 1290, 5129, and 8301R manufactured by DAICEL-ALLNEX, and KRM8200, KRM8200AE, KRM8530, and KRM8904. , KRM8531BA and KRM8452, etc. Examples of aromatic urethane (meth)acrylate compounds include EBECRYL (registered trademark) 210 and 220 manufactured by DAICEL-ALLNEX.

The curable (meth)acrylate compound can be used individually by 1 type, or can use 2 or more types together.

The curable (meth)acrylate compound preferably contains a urethane (meth)acrylate compound, and the curable (meth)acrylate compound preferably contains a polyether urethane (meth)acrylate. The content ratio of the urethane (meth)acrylate compound in the curable (meth)acrylate compound is not particularly limited. The ratio is 40 to 100 based on the total mass of the curable (meth)acrylate compound. Mass% is preferred, and 50 to 100 mass% is preferred. If it is within these ranges, the refractive index of the functional layer will easily become an appropriate value. The results show that unevenness will be further reduced.

As the hardening (meth)acrylate compound, aromatic urethane (meth)acrylate; polyether urethane (meth)acrylate; monofunctional (meth)acrylate compound; Or a combination of polyether urethane (meth)acrylate and a monofunctional (meth)acrylate compound is preferred. Also, aromatic urethane (meth)acrylate; polyether urethane (meth)acrylate; benzyl (meth)acrylate; or polyether urethane (meth)acrylate The combined use of benzyl (meth)acrylate and benzyl (meth)acrylate is preferred. Furthermore, the combination of aromatic urethane (meth)acrylate, polyether urethane (meth)acrylate, and benzyl (meth)acrylate is more preferred.

In the formation of acrylic resin, cross-linking agents, hardeners or hardening accelerators may also be used. There are no particular restrictions on these, and publicly known ones can be used. These systems may be used individually by 1 type, or may use 2 or more types together.

As the acrylic resin, an acrylic resin of thermoplastic resin can also be used. The acrylic resin as the thermoplastic resin is not particularly limited, and examples thereof include the above-mentioned (co)polymers containing structural units derived from (meth)acrylate compounds. Among these, the above-mentioned (co)polymer containing a structural unit derived from a monofunctional (meth)acrylate compound is also preferred, with polymeth(meth)acrylate (alias: polymethacrylic acid) Methyl ester, abbreviated as: PMMA) is preferred.

The weight average molecular weight (Mw) of the acrylic resin of the thermoplastic resin is not particularly limited, but is preferably 100,000 to 300,000. The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC) in terms of polystyrene.

The acrylic resin of the thermoplastic resin can be used individually by 1 type, or can use 2 or more types together.

In the formation of the functional layer, it is preferable to use a curable (meth)acrylate compound and an acrylic resin as a thermoplastic resin in combination. Furthermore, it is preferable to use polyether urethane (meth)acrylate and polymeth (meth)acrylate in combination. That is, as the acrylic resin, it is preferable to use a curable acrylic resin and a thermoplastic resin acrylic resin in combination. Furthermore, it is preferable to use a (co)polymer containing a structural unit derived from polyether urethane (meth)acrylate in combination with polymeth (meth)acrylate. Furthermore, it is more preferable to use a homopolymer composed of structural units derived from polyether urethane (meth)acrylate in combination with polymeth (meth)acrylate.

In the formation of the functional layer, when a curable (meth)acrylate compound and an acrylic resin of a thermoplastic resin are used in combination, the content ratio of the acrylic resin of the thermoplastic resin to the curable (meth)acrylate is not particularly limited. The total mass of the compound and the acrylic resin of the thermoplastic resin is preferably more than 0 mass % and not more than 60 mass %, and more preferably more than 0 mass % and not more than 50 mass %. If it is within these ranges, the refractive index of the functional layer can easily become an appropriate value. The results show that unevenness will be further reduced.

As the acrylic resin and the (meth)acrylate compound as its raw material, commercially available products or synthetic products may be used.

One type of acrylic resin may be used alone, or two or more types may be used in combination.

The content of the matrix resin in the functional layer is not particularly limited, but relative to the total mass of the functional layer, it is preferably more than 50 mass%, more preferably more than 70 mass%, and more preferably more than 90 mass%. If it is within the above range, the function of the functional layer will become better. Furthermore, relative to the total mass of the functional layer, the content of the matrix resin in the functional layer is preferably 100 mass% or less, more preferably 99 mass% or less, and more preferably 95 mass% or less. If it is within the above range, the added amount of components other than the matrix resin can be increased, and it becomes easier to further enhance the effects of the present invention and provide other desired functions.

The functional layer preferably contains particles. That is, the functional layer preferably contains at least one type of particle. The particles will further reduce display unevenness, especially display unevenness that is recognized as screen roughness and display unevenness that is recognized as brightness unevenness. Hereinafter, the particles included in the functional layer are also simply referred to as "functional layer particles".

As the functional layer particles, the same ones as those described above for the base material particles can be used. The types of functional layer particles are also the same as those of the base material particles.

As the functional layer particles, inorganic particles are preferred, and silicon dioxide (silica particles, particulate silicon dioxide) is more preferred.

The average secondary particle diameter of the functional layer particles is not particularly limited, but is preferably 10 nm or more. If it is within the above range, display unevenness will be further reduced. In addition, the average secondary particle diameter of the functional layer particles is not particularly limited, but is preferably 300 nm or less. If it is within the above range, the transparency of the film will be further improved. Furthermore, the average secondary particle diameter of the functional layer particles can be determined by directly calculating and measuring the size of the secondary particles from an electron microscope photograph of the layer (functional layer). Specifically, this method uses transmission electron microscopy (TEM) (H-7650 manufactured by Hitachi High-Technology Co., Ltd.) to measure particle images, and determines the value of 100 randomly selected secondary particles. The average diameter of circles of equal area, and this value is taken as the average secondary particle diameter.

As for the functional layer particle system, one type may be used alone, or two or more types may be used in combination.

The content of the functional layer particles in the functional layer is not particularly limited, but is preferably 0.1% by mass or more relative to the total mass of the functional layer. If it is within the above range, it becomes easier to adjust the refractive index. Furthermore, the content of the functional layer particles in the functional layer is preferably 10% by mass or less relative to the total mass of the functional layer. If it is within the above range, the transparency of the film will be further improved.

The functional layer may further contain other components than those described above as long as the effects of the present invention are not impaired. The other components are not particularly limited, and examples thereof include components used in the field of known optical films or in the field of known functional layers for optical applications. Specific examples include heat-resistant stabilizers, weather-resistant stabilizers, leveling agents, surfactants, antioxidants, anti-charge agents, slip agents, anti-blocking agents, anti-fogging agents, slip agents, dyes, and pigments. Natural oils, synthetic oils, waxes, etc., but are not limited to these.

In one embodiment of the present invention, the thickness of the functional layer is not particularly limited, but is preferably 0.1 μm or more. If it is within this range, it becomes easier to adjust the refractive index and the function of the functional layer can be well demonstrated. In addition, the thickness of the functional layer is preferably 50 μm or less. If it is within this range, it becomes easier to adjust the refractive index and the transparency of the film can be well expressed.

The optical film containing a cycloolefin resin base material preferably has a functional layer, and the functional layer contains acrylic resin or urethane resin and particles. In this case, it is preferable that the functional layer contains an acrylic resin, and the acrylic resin contains a urethane acrylate resin.

In one embodiment of the present invention, the refractive index of the optical film containing the cycloolefin resin base material is not particularly limited, but is preferably 1.500 or more, more preferably 1.505 or more, and more preferably 1.510 or more. In addition, the refractive index of the optical film containing the cycloolefin resin base material is preferably 1.535 or less, more preferably 1.525 or less, and more preferably 1.515 or less. If it is within these ranges, the refractive index of the optical film containing the cycloolefin resin base material will easily become an appropriate value. The results show that unevenness will be further reduced. nD at 25°C: The refractive index at the D line (589nm) is particularly preferably within the above range. The refractive index can be measured with a multi-wavelength Abbe refractometer (trade name: DR-M2, manufactured by ATAGO Co., Ltd.). In addition, the details of the measurement method are described in the Examples.

The refractive index of the optical film containing the cycloolefin resin base material can be adjusted according to the refractive index by forming a functional layer having a different refractive index from the cycloolefin resin base material. rate changes.

In addition, the refractive index of the optical film containing the cycloolefin resin base material can be controlled by the formulation and manufacturing method of the cycloolefin resin base material, or by the formulation or manufacturing method of the functional layer when it has a functional layer. For example, if a material with a high volume structure is used as the raw material of the cycloolefin resin as the base material of the cyclic olefin resin or as the raw material of the matrix resin of the functional layer, or if the amount of the monomer is increased, or if a low refractive index monomer is used and the amount of the material is increased, then The refractive index of an optical film containing a cycloolefin resin base material tends to become lower. Furthermore, for example, when the cycloolefin resin base material is produced using solution film formation compared to the case where the cyclo olefin resin base material is produced using melt film formation, the refractive index of the optical film containing the cyclo olefin resin base material becomes lower. tendency. For example, in the production of the functional layer, the refractive index of the optical film containing the cycloolefin resin base material tends to become lower when the film is rapidly dried compared to when the film is dried slowly. In these cases, it is presumed that the refractive index of the optical film containing the cycloolefin resin base material becomes lower because the resin density of the cycloolefin resin base material or the functional layer decreases. In addition, in the case of further increasing the refractive index, the opposite to the above may be performed. Furthermore, for example, by adding particles having a different refractive index from the cycloolefin resin base material to the cycloolefin resin base material, the refractive index of the optical film including the cycloolefin resin base material can be changed in accordance with the refractive index of the particles. For example, by adding particles with a different refractive index from the matrix resin to the functional layer, the refractive index of the optical film including the cycloolefin resin base material is changed according to the refractive index of the particles.

However, the method of controlling the refractive index of the optical film containing the cycloolefin resin base material is not limited to these methods.

Furthermore, when an optical film containing a cycloolefin resin base material has a functional layer, from the viewpoint of optical scattering (display unevenness), it is preferable that the refractive index of the functional layer is 0.002 to 0.008 lower than the refractive index of the base layer. .

In one embodiment of the present invention, the haze (%) of the optical film containing the cycloolefin resin base material is not particularly limited, but it is preferably 0.20% or more, more preferably 0.50% or more, and more preferably 0.55% or more. . In addition, the haze (%) of the optical film containing the cycloolefin resin base material is preferably 1.00% or less, more preferably 0.90% or less, and more preferably 0.85% or less. If it is within this range, display unevenness will be further reduced. The haze system can be measured in accordance with JIS K 7136:2000 using a haze meter (NDH4000, manufactured by Nippon Denshoku Industries Co., Ltd.). Here, among the optical films, for films having a functional layer (hardened layer), the value measured from the functional layer side is preferably used. In addition, the details of the measurement method are described in the Examples.

The haze of an optical film containing a cycloolefin resin base material can be controlled by, for example, the type of particles (particle size, refractive index, etc.), the amount of particles added, and the like. More specifically, the haze of the optical film can be increased by, for example, increasing the refractive index of the cycloolefin resin and the particles, or increasing the amount of particles having a refractive index difference with the cycloolefin resin. Furthermore, in order to reduce the haze of the optical film, the opposite of the above can be done.

In one embodiment of the present invention, the angular photon of the optical film containing the cycloolefin resin base material is not particularly limited, but is preferably 0.7 to 11. If it is within this range, display unevenness, especially display unevenness recognized as screen roughness and display unevenness recognized as brightness unevenness, will be further reduced. Variable angle photometry is measured by the following operations. Set the sample (optical film) on the variable angle photometer (model GP-200 manufactured by Murakami Color Technology Research Institute Co., Ltd., the inclination angle of the beam is within 0.5 degrees), and place it on the sample at the position used as the measurement reference, so that the distance from the sample Visible rays incident on the sample surface with an 80-degree tilt from the normal direction (that is, relative to the sample surface, visible rays are incident on the sample surface from a position tilted 10 degrees toward the normal direction), and the normal direction of the incident light will be The reflection direction is set to 0 degrees of the reference angle, and the intensity of the reflected light is measured every 0.1 degrees within a range of ±3.0 degrees with the aforementioned reference angle as the center. Furthermore, when measuring, the scale of the light receiving aperture is set to "6" and the scale of the beam aperture is set to "1". The variable angle luminosity is calculated by calculating the integrated value of the light amount obtained at -3.0 degrees to -2.0 degrees with the aforementioned reference angle as the center.

When the film has a slow axis, it is considered that at the position on the sample as the measurement reference, the slow axis direction will have two directions (set the counterclockwise direction as positive, the 0° direction and +180° relative to the slow axis direction). Here, when the optical film containing a cycloolefin resin base material has a slow axis, the angular photometry is tilted from the normal direction of the sample to either side of the slow axis direction of the sample (optical film). When 80-degree visible light is incident on the sample surface for measurement, it is better to have a value within the above range. In addition, the variable angle photometry is measured when visible light rays tilted 80 degrees from the normal direction of the sample are incident on the sample surface from both sides of the slow axis direction of the sample (optical film). These values are all A value within the above range is better. In addition, with respect to the slow axis direction of the sample (optical film), the counterclockwise direction is set as positive, and in all directions along the sample surface from 0° to less than +360°, rotate every 45°. , it is particularly preferable that all values measured when visible light rays tilted 80 degrees from the normal direction of the sample are incident on the surface of the sample fall within the above range.

(Method for manufacturing optical film containing cycloolefin resin base material) In one embodiment of the present invention, the manufacturing method of the optical film containing the cycloolefin resin base material is not particularly limited, and a known method can be used. Examples include a coating method, a solution film forming method, a melt film forming method (Melt film forming method), a vapor phase film forming method, etc., and these may be used in combination.

The cycloolefin resin base material is not particularly limited, but is preferably produced by a melt film forming method or a solution film forming method, and is preferably produced by a melt film forming method. In these manufacturing methods, stretching may be performed as necessary during or after film formation.

The melt film forming method is not particularly limited, and examples thereof include melt casting method (melt extrusion method), pressure molding method, expansion molding method, injection molding method, blow molding method, and stretch molding. Law etc. Among them, the melt casting method is preferred, in which a resin composition containing a cycloolefin resin and other components that can be added as necessary is heated and melted, cast on a substrate, and then cooled and solidified to form a thin film. The melt film forming method is preferably a known method. For example, the method described in paragraphs "0111" to "0116" of Japanese Patent Publication No. 5509515, or the method described in paragraphs "0224" to "0230" of Japanese Patent Application Laid-Open No. 2016-153839, etc. can be appropriately modified and adopted. However, applicable melt film forming methods are not limited to these.

In one embodiment of the present invention, the melt casting method is preferably to dry the particles before melting. The drying temperature is not particularly limited, but may be, for example, 80 to 120°C. In addition, the drying time is not particularly limited, but may be, for example, 2 to 12 hours.

The melting temperature of the melt casting method is not particularly limited, but it is preferably above the melting temperature of the cycloolefin resin used, and preferably above 220°C. In addition, from the viewpoint of the transparency of the film, the melting temperature of melt casting is preferably 350°C or lower.

In one embodiment of the present invention, the manufacturing device used in the melt casting method is not particularly limited, and a known manufacturing device used in the melt casting method can be used. Examples include, but are not limited to, a single-screw extruder, a polymer tube, a polymer filter, a T-die, a casting drum, and the like.

The solution film forming method is not particularly limited, and examples thereof include solution casting. For example, the steps include: 1) obtaining a dopant containing a cycloolefin resin, other components and solvents that can be added as necessary, 2) casting the obtained dopant on a metal support, and drying it. Methods such as a step of peeling off the support to obtain a film-like object, and 3) a step of further drying the peeled film-like object. Moreover, the aforementioned method may also have other steps.

Regarding steps 1) The dopant is prepared by dissolving the cyclic olefin resin and other components that may be added as necessary in a solvent. The mixing with the solvent can be carried out at normal temperature, in a heating environment, or in a cooling environment. The heating temperature or cooling temperature is not particularly limited as long as it is a temperature at which the cycloolefin resin can be dissolved. The solvent used for the dopant includes an organic solvent (good solvent) that can at least dissolve the cycloolefin resin. Examples of good solvents include chlorine-based organic solvents such as dichloromethane; and non-chlorine-based organic solvents such as methyl acetate, ethyl acetate, acetone, and tetrahydrofuran. Among them, methylene chloride is also preferred. The solvent used for the dopant may also include a lean solvent. Examples of lean solvents include linear or branched aliphatic alcohols having 1 to 4 carbon atoms. If the alcohol ratio in the dopant becomes high, the film-like material will be easily gelled and will be more easily peeled off from the metal support. Examples of linear or branched aliphatic alcohols having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. alcohol. Among these, ethanol is preferred because the dopant has a relatively low boiling point and stability, and has good drying properties. These solvents can be used individually by 1 type, or in combination of 2 or more types at arbitrary ratios.

The content ratio of the solvent contained in the dopant is not particularly limited, but relative to the total mass of the dopant, it is preferably 50 mass % or more, and more preferably 60 mass % or more. In addition, the content ratio of the solvent contained in the dopant is preferably 95 mass% or less, more preferably 85 mass% or less, and particularly preferably 80 mass% or less. The content ratio of the solvent component can be appropriately adjusted from the viewpoint of film production conditions, film thickness of the produced film, etc.

After preparing the dopant, it is better to filter it.

Regarding steps 2) The obtained dopant is cast on a metal support. The dopant is cast by spitting it out from the casting mold. Next, the solvent in the dopant that has been cast on the metal support is evaporated and dried. The dried dopant is peeled off from the metal support to obtain a film-like substance. The amount of residual solvent of the dopant when peeled off from the metal support (amount of residual solvent during peeling) is preferably 10 to 150 mass %, and more preferably 20 to 40 mass %. The amount of residual solvent in a dopant is defined by the following formula. The following are all the same: The amount of residual solvent of the dopant (mass %) = (the mass of the dopant before heat treatment - the mass of the dopant after heat treatment) / the mass of the dopant after heat treatment × 100 In addition, the heat treatment when measuring the amount of residual solvent refers to the heat treatment at 120°C for 60 minutes.

Regarding steps 3) Dry the resulting film. The drying temperature is not particularly limited. For example, when the glass transition temperature of the cycloolefin resin is Tg, (Tg-65)℃~(Tg+60)℃ is preferred, and (Tg-50)℃~(Tg+ 50)℃ is preferred, and (Tg-30)℃~(Tg+50)℃ is more preferred. Specific examples of the drying temperature are not particularly limited, but for example, 100°C or higher is preferred, and 120°C or higher is preferred. In addition, the stretching temperature is preferably 220°C or lower, more preferably 200°C or lower, and more preferably 180°C or lower. The amount of residual solvent in the film at the beginning of drying is preferably 2 to 50% by mass.

It is best to dry the film-like material while being transported. It is also possible to dry and stretch the film at the same time. The stretching method and stretching conditions are the same as those described below for the stretching process in the production of an optical film containing a cycloolefin resin base material. In the solution casting method, when drying and stretching a film-like object, the film-like object is stretched in the MD direction (conveying direction) by, for example, causing a circumferential speed difference between a plurality of rollers and utilizing the circumference of the rollers in between. It is better to use the speed difference method (roller method). The film is stretched in the TD direction (the direction perpendicular to the conveyance direction) by, for example, fixing both ends of the film with clamps or pins, and expanding the distance between the clamps or pins in the direction of movement ( It is better to carry out the tenter method).

In one embodiment of the present invention, when the optical film has the above-mentioned cycloolefin resin base material and functional layer, the manufacturing method of the optical film including the cycloolefin resin base material is included in the cycloolefin resin base material or its raw material film ( The method of forming the functional layer on raw film is preferred.

In addition, the "raw film of cycloolefin resin base material" refers to the film of the cycloolefin resin base material obtained after stretching under specific conditions and in a state before stretching. In addition, if the raw material film is further stretched after being tied, it may have already been stretched.

In order to improve the adhesion between the cycloolefin resin base material and the functional layer, it is preferable to apply a surface modification treatment on the surface of the cycloolefin resin base material or its raw material film where the functional layer will be formed. The surface modification treatment is not particularly limited, and known surface modification treatments can be applied. Examples include active energy ray irradiation treatment and chemical treatment. Examples of the active energy ray irradiation treatment include corona discharge treatment, plasma treatment, electron beam irradiation treatment, ultraviolet irradiation treatment, and the like. Examples of the chemical treatment include saponification treatment, treatment in which the film is immersed in an aqueous oxidant solution such as potassium dichromate solution and concentrated sulfuric acid, and then washed with water. As the surface modification treatment method, the methods described in paragraphs "0125" to "0139" of Japanese Patent Application Laid-Open No. 2016-79210 can be appropriately modified as necessary. However, the surface modification treatment methods that can be used are not limited to these. Among them, from the viewpoint of treatment efficiency, active energy ray irradiation treatment is more preferred, corona discharge treatment or plasma treatment is more preferred, and corona discharge treatment is more preferred. One of these surface modification treatments may be used alone, or two or more types may be used in combination.

The output of the corona discharge treatment is not particularly limited, but it is preferably 0.02 kW or more, and 0.04 kW or more. In addition, the output of the corona discharge treatment is preferably 5 kW or less, and more preferably 2 kW or less. In addition, the length of the electrode used for corona discharge treatment is not particularly limited. Furthermore, the corona discharge treatment is preferably performed while conveying. The conveying speed of corona discharge treatment is not particularly limited.

The corona discharge treatment device (corona treatment device) is not particularly limited, and a known one can be used, for example.

The method of forming the functional layer is not particularly limited, but it is preferably formed by a coating method. The coating method is not particularly limited and a known method can be used. Examples include wire bar coating, dipping, spraying, spin coating, roll coating, gravure coating, air knife coating, curtain coating, and slide coating. method, extrusion coating method, mold coating method, etc.

In addition to the matrix resin that can be added as necessary, or other components that can be added as necessary, the coating liquid for forming the functional layer can also contain a solvent. As a solvent, for example, water or an organic solvent can be used. The organic solvent is not particularly limited, and examples thereof include methanol, ethanol, isopropyl alcohol, acetone, tetrahydrofuran, N-methylpyrrolidone, dimethylsulfoxide, ethylene glycol monomethyl ether, and ethylene glycol. Alcohol monobutyl ether, methylene chloride, methyl ethyl ketone, cyclohexanone, etc. One type of water or organic solvent may be used alone, or two or more types may be used in combination at any ratio.

The solid content concentration of the functional layer-forming coating liquid is not particularly limited, but it is preferably 0.5 mass % or more, and more preferably 1 mass % or more based on the total mass of the functional layer-forming coating liquid. Furthermore, the solid content concentration of the functional layer-forming coating liquid is preferably 15 mass% or less, and more preferably 10 mass% or less relative to the total mass of the functional layer-forming coating liquid. If it is within this range, the operability and coating properties of the coating liquid will be further improved.

When the functional layer is formed by a coating method, the manufacturing method of the optical film containing the cycloolefin resin base material includes coating the functional layer on at least one side of the cycloolefin resin base material or its raw material film to form a coating. The step of forming a functional layer coating liquid layer is preferred. This step preferably includes drying the solvent contained in the coating liquid for forming the functional layer. Furthermore, when the functional layer is a hardened layer, it is preferable to dry the solvent contained in the coating liquid and proceed with the hardening reaction. In addition, at this time, drying and hardening may be performed simultaneously. Furthermore, at this time, in addition to drying and hardening, stretching described below may be performed simultaneously. Furthermore, it is preferable to perform heating during drying, hardening or stretching of the coating liquid for forming the functional layer.

The heating temperature and heating time can be set to a range within which the desired treatment or reaction can proceed. The heating temperature is not particularly limited, but for example, 40 to 150°C is preferred, and 60 to 130°C is preferred. The heating time is not particularly limited as long as it can achieve the desired drying or effect.

The drying conditions of the functional layer are not particularly limited. From the viewpoint of controlling the refractive index, when you want to increase the refractive index, it is better to dry at a low drying speed, that is, to dry slowly. When you want to decrease the refractive index, it is better to dry at a high speed. The drying speed is preferably rapid drying. In this specification, "slow drying" means drying at a drying speed of 0.2g/m ² ･s or less. In addition, "quick drying" means drying at a drying speed of 0.8~4.8g/m ² ･s.

The drying speed is calculated by measuring the film thickness of the coating liquid on the conveyed support, and calculating the volatilization amount of the solvent in the coating liquid from the change in the film thickness (specifically, the formula: {film thickness change ^{[ μm} ] (g/m ² ･s), and this value can be obtained as the drying rate.

Drying is not particularly limited, and drying air, electric heaters, infrared heaters, heated rollers, etc. can be used. Among these, dry wind is the best. In addition, the drying equipment is not particularly limited, but it is preferable to have air supply holes and exhaust holes for drying air.

When the functional layer is a hardened layer, the hardening of the functional layer is preferably performed by active energy ray irradiation. The active energy ray is not particularly limited, but ultraviolet rays are preferred. The output of the ultraviolet irradiation device is not particularly limited and can be, for example, 100~300W. In addition, the amount of ultraviolet irradiation is not particularly limited. It can be made, for example, 100~2000mJ/cm ² . The ultraviolet irradiation device is not particularly limited and a known device can be used. Examples thereof include air-cooled metal halide lamps (manufactured by EyeGraphics Co., Ltd.) and the like. In addition, the irradiation environment for active energy ray irradiation (preferably ultraviolet irradiation) is not particularly limited, but it is preferably flushed with an inert gas such as nitrogen, and more preferably flushed with nitrogen.

In the production of an optical film containing a cycloolefin resin base material, it is preferable to provide a step of stretching the raw material film to obtain the cycloolefin resin base material. Stretching may be performed in the state of the raw material film alone, or in the state of forming a layer of the coating liquid for forming a functional layer or a functional layer on the raw material film.

As a preferred embodiment of the method for manufacturing an optical film containing a cycloolefin resin base material, (A): (A-1) is included on at least one side of a raw material film of a cycloolefin resin base material. The steps of forming a layer of the coating liquid for forming a functional layer, (A-2) stretching the raw material film to obtain a cycloolefin resin base material, and (A-3) drying the layer of the coating liquid (updated as necessary). (hardening) to obtain a functional layer (for example, a hardened layer). Either step of the above-mentioned step (A-2) and the above-mentioned step (A-3) can be performed in advance, or both steps can be performed simultaneously.

Another preferred embodiment of the method for producing an optical film containing a cycloolefin resin base material is as follows: (B): Stretching the raw material film including (B-1) to obtain a cycloolefin resin base material The steps of (B-2) forming a layer of a coating liquid for forming a functional layer on at least one side of the cycloolefin resin base material, (B-3) drying the layer of the coating liquid (more if necessary) (hardening) to obtain a functional layer (for example, a hardened layer).

In the production of an optical film containing a cycloolefin resin base material, there is no particular limitation on the stretching method when performing stretching treatment. Examples include a method of uniaxially stretching in the length direction using the difference in circumferential speed between rolls (longitudinal uniaxial stretching); and a method of uniaxially stretching in the width direction using a tenter (horizontal uniaxial stretching). axial stretching); the method of sequentially performing longitudinal uniaxial stretching and transverse uniaxial stretching (sequential biaxial stretching); the method of performing longitudinal stretching and transverse stretching at the same time (simultaneous biaxial stretching); relative to Methods such as stretching the length direction of the film in the inclined plane direction before stretching (inclined plane stretching), etc. Here "slope direction" means a direction that is neither parallel nor vertical.

In the production of an optical film containing a cycloolefin resin base material, when performing a stretching process, the stretching ratio is not particularly limited, but is preferably 1.01 times or more, more preferably 1.5 times or more, and 1.7 times or more. Even better, 2.0 times or more is considered particularly good. Furthermore, the stretching ratio is preferably 10.0 times or less, more preferably 7.0 times or less, and more preferably 5.0 times or less. When drying the film-like material simultaneously, the stretching ratio is not particularly limited, but is preferably 1.01 times or more, more preferably 1.1 times or more, and more preferably 1.2 times or more. In addition, at this time, the stretching ratio is preferably 1.5 times or less, more preferably 1.4 times or less, and more preferably 1.3 times or less. Here, when stretching is performed in two or more steps, the product of the stretching ratios in each step is preferably within the aforementioned range.

In the production of an optical film containing a cycloolefin resin base material, during the stretching process, the stretching temperature is not particularly limited, but for example, it is preferably 100°C or higher, and more preferably 120°C or higher. In addition, the stretching temperature is preferably 220°C or lower, more preferably 200°C or lower, and more preferably 180°C or lower. In addition, when the above-mentioned drying, hardening and stretching are performed simultaneously, the stretching temperature is preferably 150°C or lower, and more preferably 130°C or lower.

From the viewpoint of improving the production efficiency of the optical film containing the cycloolefin resin base material, it is preferable to form the optical film into a long film.

(Other optical films) In at least one of the polarizing plates included in the display device according to one embodiment of the present invention, when the optical film including the base material containing the cycloolefin resin is disposed on only one side of the polarizer, the other side of the polarizer Other optical films can also be configured on one side.

Furthermore, in the display device according to one embodiment of the present invention, when a polarizing plate not having an optical film containing a base material containing a cycloolefin resin is used, the polarizing plate may be disposed on one side or both sides of the polarizing plate. Other optical films. As other optical films, there are no particular limitations, and known optical films can be used.

Other optical films preferably include resin films. The resin film is not particularly limited, and examples thereof include cellulose ester films, acrylic films, polycarbonate films, and the like. Among these, cellulose ester film is also preferred. Commercially available cellulose ester films are not particularly limited, and examples include Konica Minolta Tuck KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC6UY, and KC4UY. , KC4UE, KC8UE, KC8UY-HA, KC2UA, KC4UA, KC6UAKC, 2UAH, KC4UAH, KC6UAH (above, manufactured by Konica Minolta Co., Ltd.) or FUJITAC (registered trademark) T40UZ, T60UZ, T80UZ, TD80UL, TD60UL, TD40UL , R02, R06 (above, manufactured by Fuji Film Co., Ltd.), etc.

The thickness of the resin film is not particularly limited, but it is preferably 5 μm or more, more preferably 10 μm or more, and more preferably 20 μm or more. If it is within this range, the protection function of the polarizer will be further improved. In addition, the thickness of the resin film is not particularly limited, but it is preferably 100 μm or less, more preferably 80 μm or less, and more preferably 60 μm or less. If it is within these ranges, it becomes possible to achieve a thinner polarizing plate.

In addition to the above-mentioned resin film, other optical films may also include functional layers. The functional layer is not particularly limited, and examples thereof include functional layers used for optical applications.

(polarizer) A polarizing plate included in a display device according to an embodiment of the present invention includes a polarizer. A polarizer is an element that only allows light from a polarized surface in a certain direction to pass through.

The polarizer is not particularly limited and a known polarizer can be used, but a polyvinyl alcohol-based polarizing film is preferred. The polyvinyl alcohol-based polarizing film may be a polyvinyl alcohol-based film dyed with iodine or a polyvinyl alcohol-based film dyed with a dichroic dye. For example, as a polyvinyl alcohol-based polarizing film, a polyvinyl alcohol-based film is uniaxially stretched and then dyed with iodine or a dichroic dye (more preferably, a durability treatment is performed with a boron compound). film) etc. For example, the polyvinyl alcohol-based polarizing film may be a polyvinyl alcohol-based film dyed with iodine or a dichroic dye and then uniaxially stretched (preferably, a boron compound is used to provide durability). processed film), etc. Among these, a polyvinyl alcohol-based film dyed with iodine, subjected to a durability treatment using a boron compound, and then uniaxially stretched is particularly preferred. The absorption axis of a polarizer is usually parallel to the direction of maximum stretch.

The polyvinyl alcohol-based film used to form the polyvinyl alcohol-based polarizing film is not particularly limited, and examples thereof include ethylene units described in Japanese Patent Application Laid-Open No. 2003-248123, Japanese Patent Application Laid-Open No. 2003-342322, etc. Ethylene-modified polyvinyl alcohol with a content of 1~4 mol%, a polymerization degree of 2000~4000, and a saponification degree of 99.0~99.99 mol%.

The temperature during uniaxial stretching is not particularly limited, but is preferably 30 to 90°C. The uniaxial stretching ratio is not particularly limited, but 1.05 to 10 times is preferred, 2 to 8 times is preferred, and 4 to 6 times is preferred.

The thickness of the polarizer is not particularly limited, but it is preferably 0.1 μm or more, more preferably 1 μm or more, and more preferably 5 μm or more. If it is within this range, the polarization performance will be further improved. In addition, the thickness of the polarizer is preferably 40 μm or less, more preferably 30 μm or less, and more preferably 20 μm or less. If it is within these ranges, it becomes possible to achieve a thinner polarizing plate.

The refractive index of the polarizer is not particularly limited, but is preferably 1.500~1.520.

The polarizing plate included in the display device according to one embodiment of the present invention has an optical film containing a cycloolefin resin base material, and the refractive index difference between the optical film containing the cycloolefin resin base material and the polarizer satisfies the following formula (1): Formula (1)　0≦(refractive index of optical film - refractive index of polarizer)＜0.02 If the refractive index difference between the optical film of the above formula (1) (the aforementioned optical film containing a cycloolefin resin base material) and the polarizer is less than 0, display unevenness will occur, especially when the display unevenness is recognized as uneven brightness. Increase. In addition, if the difference in refractive index between the optical film of the above formula (1) (the aforementioned optical film containing a cycloolefin resin base material) and the polarizer is 0.02 or more, display unevenness will occur, especially when the display unevenness is recognized as screen roughness. More increase.

Furthermore, the polarizing plate included in the display device according to one embodiment of the present invention is preferably such that the refractive index difference between the optical film containing the cycloolefin resin base material and the polarizer satisfies the following formula (2): Formula (2)　0.001≦(refractive index of optical film - refractive index of polarizer)≦0.015 If it is within this range, display unevenness will be further reduced. Based on the same point of view, the upper limit of the refractive index difference between the optical film containing the cycloolefin resin base material and the polarizer is preferably 0.008 or less, and more preferably 0.005 or less.

In the display device according to one embodiment of the present invention, in at least one polarizing plate included therein, as long as the refractive index difference between at least one optical film containing a cycloolefin resin base material and the polarizer satisfies the relationship of the above formula (1) That’s it. Furthermore, in the measurement of the RMS particle size of at least the above-mentioned display device, in a polarizing plate including a polarizer having an absorption axis as an angular reference along the display surface, at least one optical film and polarizer including a cycloolefin resin base material It is better if the refractive index difference of the device satisfies the relationship of the above equation (1). Furthermore, in the measurement of the RMS particle size of the display device as described above, in the viewing side polarizing plate including a polarizer having an absorption axis as an angular reference along the display surface, at least one optical film including a cycloolefin resin base material and It is preferable that the refractive index difference of the polarizer satisfies the relationship of the above equation (1). In these cases, it is preferable that the refractive index difference between at least one optical film containing a cycloolefin resin base material and the polarizer satisfies the relationship of the above formula (2). In addition, at this time, the upper limit of the refractive index difference between at least one optical film containing a cycloolefin resin base material and the polarizer is preferably 0.008 or less, and more preferably 0.005 or less.

Here, according to the display device according to one embodiment of the present invention, among all the polarizing plates included in the display device, the refractive index difference between at least one optical film containing a cycloolefin resin base material and the polarizer satisfies the above formula (1): good. At this time, it is preferable that the refractive index difference between at least one optical film containing a cycloolefin resin base material and the polarizer satisfies the above formula (2). In addition, at this time, the upper limit of the refractive index difference between at least one optical film containing a cycloolefin resin base material and the polarizer is preferably 0.008 or less, and more preferably 0.005 or less.

Furthermore, in the display device according to an embodiment of the present invention, it is preferable that the refractive index differences between all optical films containing cycloolefin resin base materials and polarizers satisfy the above formula (1) among all polarizing plates included therein. At this time, it is preferable that the refractive index difference between all the optical films containing the cycloolefin resin base material and the polarizer satisfies the above formula (2). In addition, at this time, the upper limit of the refractive index difference between the entire optical film and the polarizer including the cycloolefin resin base material is preferably 0.008 or less, and more preferably 0.005 or less.

Furthermore, according to the display device according to one embodiment of the present invention, among all the polarizing plates included therein, the polarizing plate has only one optical film containing a cycloolefin resin base material, and the optical film containing the cycloolefin resin base material It is better that the refractive index difference with the polarizer satisfies the above formula (1). At this time, it is preferable that the refractive index difference between the optical film containing the cycloolefin resin base material and the polarizer satisfies the above formula (2). Moreover, at this time, the upper limit of the refractive index difference between the optical film containing the cycloolefin resin base material and the polarizer is preferably 0.008 or less, and more preferably 0.005 or less.

The refractive index difference between the optical film containing a cycloolefin resin base material and the polarizer satisfies the range of the above formula (2), or the upper limit of the refractive index difference between the optical film containing a cycloolefin resin base material and the polarizer. To satisfy the requirement of 0.008 or less or 0.005 or less, it is preferable that the optical film containing the cycloolefin resin base material has a functional layer, and the functional layer contains an acrylic resin or a urethane resin, and particles.

It is particularly preferred that the refractive index at the nD:D line (589nm) at 25°C satisfies the above ranges. Furthermore, the refractive index of the optical film containing the cycloolefin resin base material and the refractive index of the polarizer can be measured with a multi-wavelength Abbe refractometer (trade name: DR-M2, manufactured by ATAGO Co., Ltd.). In addition, the details of the measurement method are as described in the Examples.

(Manufacturing method of polarizing plate) The manufacturing method of the polarizing plate included in the display device according to one embodiment of the present invention is not particularly limited, and known methods can be used. For example, the polarizing plate can be manufactured by laminating the polarizer and the above-mentioned optical film containing the cycloolefin resin base material and/or other optical films through an adhesive (that is, through an adhesive layer).

The adhesive is not particularly limited, and known ones can be used. Examples include a completely saponified polyvinyl alcohol aqueous solution (water gel), an active energy ray-curable adhesive, and the like. Among them, the polarizer and the above-mentioned optical film containing a cycloolefin resin base material and/or other optical films are used in order to easily obtain a polarizing plate that is high-strength and excellent in planarity even if it is a thin film. It is better to use active energy ray hardening adhesive for bonding.

The active energy ray curable adhesive agent is not particularly limited, and examples thereof include photoradical polymerization-type compositions using photoradical polymerization, photocationic polymerization-type compositions using photocationic polymerization, and combinations of photoradical polymerizations. Mixed compositions of polymerization and photocationic polymerization, etc.

The photoradically polymerizable composition is not particularly limited. For example, a known photoradically polymerizable composition can be used. In particular, the radically polymerizable compound contained in the photoradically polymerizable composition is not particularly limited, but a compound having an ethylenically unsaturated bond capable of radical polymerization is preferred. The compound having an ethylenically unsaturated bond capable of radical polymerization is not particularly limited, but a compound having a (meth)acrylyl group is preferred. The compound having a (meth)acrylyl group is not particularly limited, and examples thereof include N-substituted (meth)acrylamide compounds, (meth)acrylate compounds, and the like. The photo-radically polymerizable composition is not particularly limited, and examples thereof include radically polymerizable compounds containing polar groups such as hydroxyl groups and carboxyl groups in a specific ratio, as described in Japanese Unexamined Patent Publication No. 2008-009329, and those that do not contain polar groups. Compositions of radically polymerizable compounds with polar groups, etc.

The photocationically polymerizable composition is not particularly limited. For example, a known photocationically polymerizable composition can be used. The cationically polymerizable compound contained in the photocationically polymerizable composition is not particularly limited, and examples thereof include a curable compound having an epoxy group, a curable compound having an epoxypropane group, and the like. The photocationically polymerizable composition is not particularly limited, and may include, for example, a composition containing (α) a cationically polymerizable compound, (β) a photocationic polymerization initiator, and (γ) as described in Japanese Patent Application Publication No. 2011-028234. Photo sensitizers that exhibit maximum absorption for light with wavelengths greater than 380 nm, and compositions of (δ) naphthalene photosensitizers, etc.

Preferable examples of active energy ray curable adhesives include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate and Epolead (registered trademark). GT-301 (alicyclic epoxy resin manufactured by Daicel Co., Ltd.), 1,4-butanediol diepoxypropyl ether, triarylsonium hexafluorophosphate, 9,10-dibutoxyanthracene , and the composition of 1,4-diethoxynaphthalene, etc.

The manufacturing method of a polarizing plate using an active energy ray-curable adhesive is not particularly limited. Examples thereof include 1) coating at least one of the bonding surfaces of the polarizer and the optical film with an active energy ray-curable adhesive. The step of adhesive, 2) the step of bonding the polarizer and the optical film through the obtained adhesive layer, 3) irradiating the active energy ray in the state of bonding the polarizer and the optical film through the adhesive layer, so that the adhesive The step of layer hardening to obtain a polarizing plate, 4) the manufacturing method of the step of punching the obtained polarizing plate into a specified shape (cutting), etc. Before step 1), if necessary, it may further include a step of 5) performing an easy-adhesion treatment (for example, corona discharge treatment or plasma treatment) on the surface of the optical film that is attached to the polarizer.

In the application of the active energy ray curable adhesive in step 1), the thickness of the cured adhesive layer is not particularly limited. However, the coating of the active energy ray-curable adhesive is preferably carried out so that the thickness of the adhesive layer after hardening becomes 0.01 μm or more, and it is preferably carried out so that it becomes 0.1 μm or more. It is better to make it 0.5 μm or more. If it is within this range, the adhesion will be further improved. In addition, the active energy ray curable adhesive is preferably applied so that the thickness of the adhesive layer after curing becomes 10 μm or less, more preferably 5 μm or less, and 3 μm or less. Better behavior in the future. If it is within these ranges, the polarizing plate can be made thinner.

In the step 3), the active energy rays to be irradiated are not particularly limited, and examples thereof include visible rays, ultraviolet rays, X-rays, electron rays, and the like. Since the operation is easy and the hardening speed is sufficient, it is generally better to use ultraviolet light. The irradiation conditions of ultraviolet rays only need to be conditions that can harden the adhesive. For example, the amount of ultraviolet irradiation is preferably a cumulative light amount of 50~1500mJ/ ^cm2 , and a preferably 100~1000mJ/ ^cm2 . It is best to irradiate ultraviolet rays while transporting. The ultraviolet irradiation device is not particularly limited, and a known device can be used, for example.

In step 5), corona discharge treatment is used as an easy adhesion treatment. However, one type of surface modification treatment system may be used alone, or two or more types may be used in combination. The output of the corona discharge treatment is not particularly limited, but it is preferably 0.02kW or more, and 0.04kW or more. In addition, the output of the corona discharge treatment is preferably 5 kW or less, and more preferably 2 kW or less. In addition, it is preferable to perform corona discharge treatment while transporting. The conveying speed of corona discharge treatment is not particularly limited. The corona discharge treatment device (corona treatment device) is not particularly limited, and a known one can be used, for example.

Furthermore, the effects of the present invention can also be said to be achieved by applying the polarizing plate described in the present invention to a display device unit. Therefore, another aspect of the present invention can also be said to be related to a polarizing plate, which has a polarizer and an optical film, wherein the aforementioned optical film has at least a base material, the aforementioned base material contains at least a cycloolefin resin, and the aforementioned optical film and the aforementioned optical film The refractive index difference of the polarizer satisfies the following formula (1), Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02 When the display device displays black with the polarizing plate assembled in the display device, the RMS grain size of the display image photographed at a position tilted 10° from the display surface toward the viewing side (the RMS grain size of the display device) is: 0.30~1.34. A preferred embodiment of the present invention can also be said to be about a polarizing plate, which has a polarizer and an optical film, wherein the aforementioned optical film has at least a base material, the aforementioned base material contains at least a cycloolefin resin, and the aforementioned optical film and the aforementioned The refractive index difference of the polarizer satisfies the following formula (1), Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02 When the display device displays black with the polarizing plate assembled in the display device, the RMS grain size of the display image photographed at a position tilted 10° from the display surface toward the viewing side (the RMS grain size of the display device) is: 0.30~1.30.

Furthermore, the details or preferred aspects of the polarizing plate of this aspect or the optical film containing the cycloolefin resin base material included therein are respectively the same as those of the polarizing plate included in the display device of the aspect of the present invention. The instructions on the board are the same. In addition, detailed or preferable aspects of a display device incorporating the polarizing plate of this aspect or a display device unit combined with the polarizing plate are the same as those described below for the display device of one aspect of the present invention.

The polarizing plate according to one embodiment of the present invention is preferably assembled on the viewing side of the display unit of the aforementioned display device unit. Furthermore, it is preferable that the polarizing plate according to one embodiment of the present invention is assembled on the viewing side of the display unit of the display device unit and on the side opposite to the viewing side. At this time, the absorption axis of the polarizer of the polarizing plate assembled on the viewing side of the display unit is orthogonal to the absorption axis of the polarizer of the polarizing plate assembled on the side opposite to the viewing side of the display unit. (That is, becoming an orthogonal Nicol) is better.

[Display device unit] A display device according to an embodiment of the present invention includes a display device unit. In this specification, a display device unit refers to components or an assembly thereof necessary for the display of the display device, and is other than the above-mentioned polarizing plate. The display device unit preferably includes a display unit.

The display device according to one embodiment of the present invention is not particularly limited, but a liquid crystal display device or an organic electroluminescence (organic EL) display device is preferred, and a liquid crystal display device is more preferred. That is, in the display device according to one embodiment of the present invention, it is preferable that the display device unit includes a display unit, and the display unit is a liquid crystal unit or an organic EL unit.

In one embodiment of the present invention, when the display device is a liquid crystal display device, the display device unit is not particularly limited, and preferably includes a liquid crystal unit of the display unit and a backlight of the light source. The liquid crystal cell and backlight are not particularly limited, and for example, known ones can be used. Furthermore, in one embodiment of the present invention, when the display device is an organic EL display device, the display device unit includes at least an organic EL unit of the display unit. The organic EL unit is not particularly limited, and for example, known ones can be used. The display device unit may further include a frame, a touch panel, etc. when necessary. There are no particular restrictions on these, and for example, publicly known ones can be used.

[Construction example of a better display device] A preferred embodiment of the present invention includes, for example, a liquid crystal cell, a first polarizing plate disposed on one side of the liquid crystal cell, and a second polarizing plate disposed on the other side of the liquid crystal cell. LCD devices, etc. Here, at least one of the first polarizing plate and the second polarizing plate is the above-mentioned polarizing plate containing an optical film containing a cycloolefin resin base material. It is preferable that both the first polarizing plate and the second polarizing plate are the above-mentioned polarizing plates containing an optical film containing a cycloolefin resin base material. At this time, in each of the first polarizing plate and the second polarizing plate, it is preferable that the optical film containing the cycloolefin resin base material is disposed on the surface of the polarizer on the liquid crystal cell side. Furthermore, the above-mentioned optical film containing a cycloolefin resin base material is more preferably provided with the above-mentioned functional layer in addition to the cycloolefin resin base material. Furthermore, in this case, it is particularly preferable to include an easy-adhesive layer as the above-mentioned functional layer, and the easy-adhesive layer is disposed on the polarizer side surface of the cycloolefin resin base material. Furthermore, in each of the first polarizing plate and the second polarizing plate, it is more preferable that another optical film is disposed on the surface of the polarizer opposite to the liquid crystal cell. Furthermore, the display device unit includes at least a liquid crystal unit. The display device unit preferably further includes a backlight.

It is preferable that the absorption axis of the polarizer of the first polarizing plate and the absorption axis of the polarizer of the second polarizing plate are orthogonal to each other (that is, they become orthogonal Nicols).

The method of bonding the liquid crystal display device and the polarizing plate is not particularly limited. It is preferably bonded through an adhesive or an adhesive (i.e., through an adhesive layer or an adhesive layer), and preferably through an adhesive. Better. There are no particular restrictions on the adhesive, and known ones can be used. For example, the adhesive agent described in the above-mentioned manufacturing method of a polarizing plate is mentioned. As the adhesive, there are no particular restrictions, and publicly known ones can be used. Examples include acrylic adhesives, epoxy adhesives, urethane adhesives, and the like.

The display mode of the liquid crystal cell is not particularly limited, and examples thereof include lateral electric field effect (IPS) mode, vertical alignment (VA) mode (vertical alignment mode: including multi-area vertical alignment (MVA) mode, patterned vertical alignment mode). Alignment (PVA) mode), continuous pyrotechnic arrangement (CPA) mode, mixed arrangement nematic (HAN) mode, twisted nematic (TN) mode, super twisted nematic (STN) mode, optically compensated bending (OCB) mode, etc. . Among them, the VA mode is preferable from the viewpoint of achieving the effect of the present invention more effectively. Therefore, in a preferred embodiment of the present invention, the display device unit is preferably a vertical alignment (VA) liquid crystal display device unit (ie, a display device unit including a vertical alignment (VA) mode liquid crystal unit).

Hereinafter, an example of a liquid crystal display device according to a preferred embodiment of the present invention will be described. However, the display device of the present invention is not limited to the following description.

FIG. 3 is a schematic diagram showing an example of the basic structure of a liquid crystal display device according to an embodiment of the present invention. FIG. 4 is a schematic diagram showing another example of the basic structure of a liquid crystal display device according to an embodiment of the present invention. As shown in FIGS. 3 and 4 , a liquid crystal display device 10 according to an embodiment of the present invention includes a liquid crystal cell 30 , a first polarizing plate 50 disposed on one side of the liquid crystal cell 30 , and a first polarizing plate 50 disposed on one side of the liquid crystal cell 30 . The second polarizing plate 70 and the backlight 90 are on the other side. Here, the display device unit includes a liquid crystal unit 30 and a backlight 90 .

The display mode of the liquid crystal unit 30 is not particularly limited, and various display modes as described above can be exemplified. Among them, the VA mode is preferred.

The first polarizing plate 50 includes: a first polarizer 51 disposed on one side of the liquid crystal unit 30 (the viewing side), and a first polarizer 51 disposed on the surface opposite to the liquid crystal unit 30 . The optical film 53 (F1) (the surface on the viewing side) and the optical film 55 (F2) arranged on the surface of the first polarizer 51 on the liquid crystal unit 30 side.

The second polarizing plate 70 includes: a second polarizer 71 disposed on the other surface of the liquid crystal unit 30 (the surface on the backlight 90 side); and an optical film 73 disposed on the surface of the second polarizer 71 on the liquid crystal unit 30 side. (F3). The optical film 75 (F4) is arranged on the surface of the second polarizer 71 opposite to the liquid crystal unit 30 (the surface on the backlight 90 side).

Each optical film in the first polarizing plate 50 and the second polarizing plate 70 can also be said to be a protective film for protecting the polarizer. Furthermore, it is preferable that the absorption axis of the first polarizer 51 and the absorption axis of the second polarizer 71 are orthogonal to each other (that is, they become orthogonal Nicols).

At least one of the optical films 53(F1), 55(F2), 73(F3) and 75(F4) is the above-mentioned optical film containing the cycloolefin resin base material. Among them, it is also preferable that the optical films 55 (F2) and 73 (F3) are the above-mentioned optical films containing the cycloolefin resin base material. In addition, at this time, it is more preferable that the optical films 55 (F2) and 73 (F3) each have the above-mentioned functional layer in addition to the cycloolefin resin base material.

Optical films 53 (F1) and 75 (F4) are preferably optical films other than optical films containing a cycloolefin resin base material, and cellulose ester films are particularly preferred.

As shown in FIG. 4 , it is more preferable that the optical films 55 (F2) and 73 (F3) have cycloolefin resin base materials 551 and 731 and the above-mentioned functional layers 552 and 732 respectively. At this time, in the first polarizing plate 50 , the functional layer 552 can be disposed on any one surface of the cycloolefin resin base material 551 , or can be disposed on both sides of the cycloolefin resin base material 551 . The surface on the first polarizer 51 side is particularly suitable. In addition, in the second polarizing plate 70, the functional layer 732 of the optical film 73 (F3) can be disposed on either side of the cycloolefin resin base material 731, or can be disposed on both sides to dispose on the cycloolefin resin. The surface of the base material 731 on the second polarizer 71 side is particularly preferred.

The present invention includes the following aspects and forms, but is not limited by them: [1] A display device having a polarizing plate and a display device unit, wherein The aforementioned polarizing plate has a polarizer and an optical film, The aforementioned optical film has at least a base material, The aforementioned base material contains at least a cycloolefin resin, and the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (1); Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02; When the aforementioned display device displays black, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.34. [2] The display device of [1], wherein the aforementioned RMS granularity is 0.30~1.30; [3] The display device of [1] or [2], wherein the aforementioned optical film further has an organic layer; [4] The display device according to [3], wherein the refractive index difference between the optical film and the polarizer satisfies the following formula (2); Formula (2)　0.001≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)≦0.015; The aforementioned functional layer contains acrylic resin or urethane resin, and particles; [5] The display device of [3] or [4], wherein the functional layer includes an acrylic resin, and the acrylic resin includes a urethane acrylate resin; [6] The display device according to any one of [1] to [5], wherein the aforementioned display device unit is a vertical alignment (VA) liquid crystal display device unit; [7] The display device according to any one of [1] to [6], wherein at least one of the aforementioned polarizing plates is arranged on the viewing side of the display unit of the aforementioned display device unit; [8] A polarizing plate having a polarizer and an optical film, wherein The aforementioned optical film has at least a base material, The aforementioned base material contains at least a cycloolefin resin, and the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (1); Formula (1)　0≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)＜0.02; When the above-mentioned polarizing plate is assembled in a display device and the above-mentioned display device displays black, the RMS granularity of the display image photographed at a position tilted 10° from the display surface toward the viewing side is 0.30 to 1.34; [9] The polarizing plate of [8], wherein the aforementioned RMS particle size is 0.30~1.30; [10] The polarizing plate of [8] or [9], wherein the aforementioned optical film further has an organic layer. [11] The polarizing plate of [10], wherein the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (2); Formula (2)　0.001≦(refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer)≦0.015; The aforementioned functional layer further contains acrylic resin or urethane resin, and particles; [12] The polarizing plate of [10] or [11], wherein the functional layer contains an acrylic resin, and the acrylic resin contains a urethane acrylate resin; [13] The polarizing plate according to any one of [8] to [12], wherein the aforementioned display device has a display device unit, and the aforementioned display device unit is a vertical alignment (VA) liquid crystal display device unit; [14] The polarizing plate according to any one of [8] to [13], wherein the display device has a display device unit and is assembled on the viewing side of the display unit of the display device unit. [Example]

Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these. In addition, although the expression of "part" or "%" is used in the Example, when it is not specifically defined, it means "part by mass" or "% by mass".

<Manufacture of optical film> (Manufacture of cycloolefin resin a1) ・Ring-opening polymerization adds tricyclo[4.3.0.1 ^2,5 ]dec-3-ene (hereinafter also referred to as "DCP") in a nitrogen-substituted reactor ), tetracyclo[4.4.0.1 ^2,5 .1 ^7,10 ] dodec-3-ene (hereinafter also referred to as "TCD"), 1,3-dimethyldodecahydrocyclopenta[a]indene ( 7 parts of a mixture (mass ratio 18/18/4/60) of 2-hydroxyethyl acrylate (hereinafter also referred to as "MTHF") and 2-hydroxyethyl acrylate (hereinafter also referred to as "HEA") (relative to the monomer used for polymerization ( monomer) with a total amount of 1 mass%), and 1600 parts of cyclohexane, then add 0.55 parts of tri-iso-butylaluminum, 0.21 parts of isobutyl alcohol, 0.84 parts of diisopropyl ether as a reaction regulator, and 3.24 parts of 1-hexene as molecular weight regulator.

To this, 24.1 parts of a 0.65% tungsten hexachloride solution dissolved in cyclohexane was added, and the mixture was stirred at 55° C. for 10 minutes.

Then, the reaction system was kept at 55°C, and 693 parts of a mixture of DCP, TCD, MTHF, and HEA (mass ratio 18/18/4/60) were dissolved in cyclohexane at a concentration of 0.65%. 48.9 parts of the tungsten chloride solution was continuously dripped into the system over 150 minutes. Thereafter, the reaction was continued for 30 minutes to complete the polymerization, and a ring-opening polymerization reaction liquid containing a ring-opening polymer was obtained.

After the polymerization is completed, the polymerization conversion rate of the monomer measured by gas chromatography is 100% at the end of the polymerization.

・Hydrogenation The obtained ring-opening polymerization reaction liquid is transferred to a pressure-resistant hydrogenation reactor, and a diatomite-supported nickel catalyst (manufactured by Nichiwa Chemical Co., Ltd. (currently Nichiwa Catalyst Chemical Co., Ltd.), product name "T8400RL") is added ", nickel loading rate 57%) 1.4 parts and 167 parts cyclohexane, react at 180°C and hydrogen pressure 4.6MPa for 6 hours to obtain a reaction solution. Using Radiolite #500 as a filter bed, the reaction solution was pressure filtered (manufactured by IHI Co., Ltd., product name "Funda Filter") at a pressure of 0.25 MPa to remove the hydrogenation catalyst and obtain a colorless and transparent hydride solution. .

Next, antioxidant: pentaerythritol [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (manufactured by BASF JAPAN Co., Ltd., product name) was prepared per 95 parts of the aforementioned hydride. Add 0.5 part of "Irganox (registered trademark) 1010") to the hydride solution and dissolve it. Next, a filter (manufactured by 3M Company, product name "Zeta Plus Filter 30H", pore size 0.5~1 μm) is used for filtration in order, and then another metal fiber filter (manufactured by Nichida Co., Ltd., pore size 0.4 μm) is used for filtration. Filter to remove tiny solid components and obtain a filtered solution.

Next, the filtered solution was dried using a cylindrical concentration dryer (manufactured by Hitachi, Ltd.) at a temperature of 270° C. and a pressure of 1 kPa or less. Thereby, cyclohexane and other volatile components of the solvent are removed from the filtered solution, and the resin solid content is obtained. The resin solid content is extruded in a molten state from a mold directly connected to the concentration dryer into a strand shape. After cooling, the extruded resin solid content is cut to obtain particles of hydrogenated ring-opening polymer (including particles of cycloolefin resin a1).

Furthermore, when measured in terms of polystyrene by gel permeation chromatography (GPC), the weight average molecular weight (Mw) of the cycloolefin resin a1 was 70,000.

(Manufacture of cycloolefin resin a2) In the production of cycloolefin resin a1, in addition to adding 7 parts (1% by mass relative to the total amount of monomers used for polymerization) and 693 parts of a mixture of DCP, TCD, MTHF, and HEA, Except that the mass ratio of DCP, TCD, MTHF, and HEA was changed to a mass ratio of 10/20/10/60, the same operation was performed to obtain particles of the hydrogenated compound of the ring-opened polymer (including particles of the cycloolefin resin a2).

Furthermore, when measured in terms of polystyrene by gel permeation chromatography (GPC), the weight average molecular weight (Mw) of the cycloolefin resin a2 was 90,000.

(Manufacture of cycloolefin resin a3) In the production of cycloolefin resin a1, in addition to adding 7 parts (1% by mass relative to the total amount of monomers used for polymerization) and 693 parts of a mixture of DCP, TCD, MTHF, and HEA, Except that the mass ratio of DCP, TCD, MTHF, and HEA was changed to a mass ratio of 25/25/10/40, the same operation was performed to obtain particles of the hydrogenated compound of the ring-opened polymer (including particles of the cycloolefin resin a3).

Furthermore, when measured in terms of polystyrene by gel permeation chromatography (GPC), the weight average molecular weight (Mw) of the cycloolefin resin a3 was 60,000.

(Manufacture of cycloolefin resin a4) The copolymerization reaction of ethylene and bicyclo[2.2.1]hept-2-ene (common name: norbornene) is carried out in the manner shown below.

To a glass reaction vessel with a volume of 500 ml equipped with a stirring device, nitrogen as an inert gas was circulated at a flow rate of 50 Nl/hr for 30 minutes, then 200 ml of toluene and 15 g of norbornene were added, and then triisobutylaluminum-decane was added Solution (concentration 1.000mM/ml) 0.30ml. Next, the polymerization solvent was stirred at a rotation speed of 1200 rpm while adjusting the solvent temperature to 40°C. After the solvent temperature reaches 40°C, in addition to nitrogen, ethylene is circulated to the reaction vessel at a supply rate of 25Nl/hr. After 10 minutes, the toluene solution of triphenylcarbenium (4-pentafluorophenyl) borate ( 7 ml of (concentration 0.005mM/ml) was added to the reaction vessel, and then, from the dropping funnel at the top of the reaction vessel, the previously prepared (eta ⁵ -C ₅ Me ₄ SiMe ₃ )Sc(CH ₂ C ₆ H ₄ NMe ₂ -o) 7 ml of toluene solution ₂ (concentration 0.005mM/ml) was added to the glass reaction vessel and polymerization started. Here, Me represents a methyl group, and eta ⁵ represents a hapticity of 5.

After 15 minutes, 5 ml of methanol was added to stop the polymerization, and a polymerization solution containing a copolymer of ethylene and norbornene was obtained. Thereafter, the polymerization solution was transferred to a separately prepared beaker with a volume of 1 L, and 5 ml of concentrated hydrochloric acid and a stirrer were added, and the mixture was brought into contact with strong stirring for 2 hours to perform a deashing operation. The polymerization solution was placed in a beaker with approximately 3 times the volume of acetone, and the delimed polymerization solution was added with stirring to form a copolymer. The precipitated copolymer was separated from the filtrate by filtration. The obtained polymer containing the solvent was dried under reduced pressure at 130° C. for 12 hours, and an ethylene-norbornene copolymer (copolymer of ethylene and norbornene) (cycloolefin resin a4) was obtained. The mass ratio of ethylene to norbornene in the obtained ethylene-norbornene copolymer was a mass ratio of 46/54.

Thereafter, the obtained cycloolefin resin a4 is granulated to obtain particles containing the cycloolefin resin a4.

Furthermore, when measured in terms of polystyrene by gel permeation chromatography (GPC), the weight average molecular weight (Mw) of the cycloolefin resin a4 was 50,000.

(Manufacture of pellets containing cycloolefin resin a5) A copolymer obtained by copolymerizing compound C1 represented by the following chemical formula (C1) and HEA at a ratio of 80/20 (mass ratio) was prepared as cycloolefin resin a5.

Thereafter, the obtained cycloolefin resin a5 is made into a pellet form, and pellets containing the cycloolefin resin a5 are obtained.

Furthermore, when measured in terms of polystyrene by gel permeation chromatography (GPC), the weight average molecular weight (Mw) of the cycloolefin resin a5 was 50,000.

(Synthesis of polyether urethane acrylate U1) Polyether polyol (Sanniks (registered trademark) diol PP-2000, number average molecular weight 2,000, Sanyo Chemical Industry Co., Ltd.) as the component (ua1) was put into a flask equipped with a stirrer, a thermometer, a reflux cooler, and a nitrogen introduction tube. Co., Ltd.) 400 parts by mass. Next, while blowing in nitrogen gas, the temperature in the system was raised to 60°C, and after uniformly dissolving, 54 parts by mass of toluene diisocyanate as the component (ua2) was added, and the temperature was further raised to 100°C and kept at the temperature for 6 hours. And, after the temperature was lowered to 90° C. and the nitrogen blowing was stopped, 10 parts by mass of 2-hydroxyethyl acrylate as the component (ua3) and 0.5 parts by mass of hydroquinone monomethyl ether as a polymerization inhibitor were added, and the temperature was maintained for 7 hours. . After confirming the disappearance of the isocyanate group in the reaction solution by IR measurement, the reaction was completed, and a polyether urethane acrylate (U1) with a number average molecular weight of 11,000 was obtained.

(Preparation of particle dispersion 1) Use a dissolver to stir and mix 10 parts by mass of silica particles (R972V manufactured by Japan Aerosil Co., Ltd., average secondary particle diameter 200 nm) and 90 parts by mass of ethanol for 30 minutes, and then disperse them using a high-pressure disperser named Manton Gaulin. Prepare a dispersion liquid. While stirring the obtained dispersion, 65 parts by mass of methylene chloride was added, and the mixture was stirred and mixed using a dissolver for 30 minutes to dilute. The obtained solution was filtered using a polypropylene duct filter TCW-PPS-1N manufactured by Advantech Toyo Co., Ltd. to obtain particle dispersion 1.

(Preparation of particle dispersion 2) Use a dissolver to stir and mix 10 parts by mass of silica particles (R812 manufactured by Japan Aerosil Co., Ltd., average secondary particle diameter 50 nm) and 90 parts by mass of ethanol for 30 minutes, and then disperse them using a high-pressure disperser such as Manton Gaulin. Prepare a dispersion liquid. The obtained dispersion liquid was stirred and 65 parts by mass of methylene chloride was added at the same time. The mixture was stirred and mixed using a dissolver for 30 minutes and diluted. The obtained solution was filtered using a polypropylene wind cartridge filter TCW-PPS-1N manufactured by Advantech Toyo Co., Ltd. to obtain particle dispersion 2.

(Preparation of particle dispersion 3) Use a dissolver to stir and mix 10 parts by mass of silica particles (R972V manufactured by Japan Aerosil Co., Ltd., average secondary particle diameter 200 nm) and 90 parts by mass of ethanol for 30 minutes, and then disperse them using a high-pressure disperser named Manton Gaulin. Prepare a dispersion liquid. The obtained dispersion liquid was stirred, and 65 parts by mass of ethanol was added at the same time, and stirred and mixed using a dissolver for 30 minutes to dilute it. The obtained solution was filtered using a polypropylene duct filter TCW-PPS-1N manufactured by Advantech Toyo Co., Ltd. to obtain particle dispersion 3.

(Preparation of coating liquid b1 for forming functional layer) The following components were mixed at 60°C to prepare the coating liquid b1 for forming the functional layer: Polyether urethane acrylate (U1): 50.0 parts by mass Benzyl acrylate (FA-BZA, manufactured by Showa Denko Materials Co., Ltd., refractive index (25°C) 1.5132): 50.0 parts by mass Particle dispersion 1: 86.0 parts by mass Methyl ethyl ketone (MEK): 3010.0 parts by mass Cyclohexanone: 90.0 parts by mass.

(Preparation of coating liquid b2 for forming functional layer) The following components are mixed to prepare the coating liquid b2 for forming a functional layer: Aromatic urethane (meth)acrylate (EBECRYL (registered trademark) 220, manufactured by DAICEL-ALLNEX Co., Ltd.): 100.0 parts by mass Particle dispersion 1: 86.0 parts by mass Methyl ethyl ketone (MEK): 3010.0 parts by mass Cyclohexanone: 90.0 parts by mass.

(Preparation of coating liquid b3 for forming functional layer) The following components are mixed to prepare the coating liquid b3 for forming a functional layer: Benzyl acrylate (FA-BZA, manufactured by Showa Denko Materials Co., Ltd., refractive index (25°C) 1.5132): 100.0 parts by mass Particle dispersion 1: 86.0 parts by mass Methyl ethyl ketone (MEK): 3010.0 parts by mass Cyclohexanone: 90.0 parts by mass.

(Preparation of coating liquid b4 for forming functional layer) The following components are mixed to prepare the coating liquid b4 for forming a functional layer: Polyether urethane acrylate (U1): 50.0 parts by mass Benzyl acrylate (FA-BZA, manufactured by Showa Denko Materials Co., Ltd., refractive index (25°C) 1.5132): 50.0 parts by mass Particle dispersion 2: 86.0 parts by mass Methyl ethyl ketone (MEK): 3010.0 parts by mass Cyclohexanone: 90.0 parts by mass.

(Preparation of coating liquid b5 for forming functional layer) The following components are mixed to prepare the coating liquid b5 for forming a functional layer: Polyether urethane acrylate (U1): 50.0 parts by mass Polymethyl methacrylate (PMMA) (manufactured by Kaneka Co., Ltd., Mw 150,000, refractive index (25°C) 1.49): 50.0 parts by mass Particle dispersion 1: 86.0 parts by mass Methyl ethyl ketone (MEK): 3010.0 parts by mass Cyclohexanone: 90.0 parts by mass.

(Preparation of coating liquid b6 for forming functional layer) The following components are mixed to prepare the coating liquid b6 for forming a functional layer: Water-based urethane resin (polyurethane aqueous dispersion) (SuperFlex (registered trademark) 210, manufactured by Daiichi Industrial Pharmaceutical Co., Ltd., solid content 35%): 228.6 parts by mass Epoxy compound (Denacol (registered trademark) EX-521, manufactured by Nagase Chemical Co., Ltd.): 16.0 parts by mass Adipodihydrazine: 4.0 parts by mass Particle dispersion 3: 86.0 parts by mass Ethanol: 3100.0 parts by mass.

(Production of optical film 1 with functional layer) The particles containing the cycloolefin resin a1 produced above were dried at 100° C. for 5 hours. Thereafter, the dried particles were supplied to a single-screw extruder, and were extruded from a T-shaped die on a casting drum through a polymer tube and a polymer filter at a resin temperature of 260° C. into a sheet shape and then cooled. In this way, a pre-stretched film with a thickness of 80 μm and a width of 675 mm was obtained.

Next, the stretching treatment was performed by directly and continuously feeding the pre-stretched film to a tenter-type transverse stretching machine, and performing transverse uniaxial stretching at a stretching temperature of 145°C and a stretching ratio of 2 times. , cut and remove the left and right ends of the stretched film in the width direction, and produce a cycloolefin resin base material with a thickness of 60 μm.

Subsequently, a corona treatment device (manufactured by Kasuga Electric Co., Ltd.) was used to perform discharge treatment on the surface of the cycloolefin resin base material under the conditions of an output of 500 W, an electrode length of 1.35 m, and a conveyance speed of 5 m/min.

Furthermore, on the surface of the cycloolefin resin base material that has been subjected to discharge treatment, the coating liquid b1 for forming the functional layer is applied by the mold coating method at a coating speed = 30 m/min and a wet coating amount = 17.5 ml/m. ^2. Apply and slowly dry with drying air (90°C) at a drying speed of 0.1g/m ² ･s. Afterwards, a 160W/cm air-cooled metal halide lamp (manufactured by EyeGraphics Co., Ltd.) was used under nitrogen purge to irradiate ultraviolet rays with an irradiation dose of 50mJ/ ^cm2 to harden the coating layer, forming a finished film with a thickness of 1 μm. layer (hardened layer). Through this operation, the optical film 1 is produced.

(Production of optical film 2 with functional layer) In the production of the above-mentioned optical film 1, except that the drying conditions after application of the coating liquid for forming the functional layer were changed to a drying speed of 3.0 g/m ² ･s The optical film 2 is formed in the same manner except for rapid drying.

(Manufacture of optical film 3 with functional layer) In the production of the optical film 1 described above, the optical film 3 was produced in the same manner except that a film obtained by the solution casting method described below was used as a film before stretching.

[Solution casting method] [Modulation of dopant 1] Dopant 1 of the following composition was prepared. First, methylene chloride and ethanol are added to the pressurized dissolution tank. Next, the particles of the cycloolefin resin a1 obtained above were stirred and simultaneously put into a pressurized dissolution tank. Then, the mixture was heated to 60° C., and the particles of cycloolefin resin a1 were dissolved while stirring. At this time, the heating temperature was raised from room temperature at 5°C/min, and after dissolution for 30 minutes, the temperature was lowered at 3°C/min.

Using SHP150 manufactured by Roki Techno Co., Ltd., the obtained mixture was filtered at a filtration flow rate of 300L/m ² ･h and a filtration pressure of 1.0×10 ⁶ Pa to obtain dopants.

(Composition of dopant 1) Cyclic olefin resin a1: 100 parts by mass Dichloromethane: 235 parts by mass Ethanol: 15 parts by mass.

[Film making] Next, using an endless endless belt casting device, the dopant 1 was evenly cast on the stainless steel belt support at a temperature of 31° C. and a width of 1800 mm. The temperature of the stainless steel strip is controlled at 28°C. The conveying speed of the stainless steel belt is set to 20m/min.

On a stainless steel tape support, the solvent was evaporated until the amount of residual solvent in the cast film became 30%. Next, it was peeled off from the stainless steel belt support at a peeling tension of 128 N/m. The peeled film was transported using a plurality of rollers, and the obtained film was stretched 1.2 times in the width direction using a tenter at 150°C. Thereafter, it was dried while being transported by a roller, and the end portion clamped by the tenter clamp was cut using a laser cutter and wound up to produce a cycloolefin resin base material with a thickness of 60 μm.

(Production of optical film 4 with functional layer) In the above-mentioned production of the optical film 1, the optical film 4 is formed in the same manner except that the type of the functional layer-forming coating liquid is changed to the functional layer-forming coating liquid b2.

(Production of optical film 5 with functional layer) In the above-mentioned production of the optical film 1, the optical film 5 is formed in the same manner except that the type of the functional layer-forming coating liquid is changed to the functional layer-forming coating liquid b3.

(Manufacture of optical film 6 with functional layer) In the above-mentioned production of the optical film 1, the optical film 6 is formed in the same manner except that the type of the functional layer-forming coating liquid is changed to the functional layer-forming coating liquid b4.

(Manufacture of optical film 7 with functional layer) In the production of the above-mentioned optical film 1, in addition to changing the type of particles used to form the film before stretching to particles containing cycloolefin resin a2, and changing the type of coating liquid for forming a functional layer to a coating for forming a functional layer Except for liquid b5, the optical film 7 is formed in the same manner.

(Manufacture of optical film 8) A cyclic olefin resin base material was produced in the same manner as in the production of the optical film 7 described above, and this base material was used as the optical film 8 .

(Manufacture of optical film 9 with functional layer) In the production of the above-mentioned optical film 7, when forming the pre-stretched film, in addition to the particles containing the cyclic olefin resin a2, alumina nanoparticles (manufactured by EM JAPAN Co., Ltd., average primary particle diameter 80 nm) are also used. The optical film 9 was produced in the same manner except that the particles and the alumina nanoparticles were supplied to the single-screw extruder in such a manner that the total mass thereof became 0.7% by mass.

(Production of optical film 10 with functional layer) In the production of the optical film 7 described above, the optical film 10 was produced in the same manner except that the type of particles used to form the pre-stretched film was changed to particles containing the cycloolefin resin a4.

(Manufacture of optical film 11) A cycloolefin resin base material was produced in the same manner as in the production of the optical film 1 described above, and this base material was used as the optical film 11 .

(Manufacture of optical film 12) In the production of the optical film 11 described above, the optical film 12 is produced in the same manner except that the type of particles used to form the pre-stretched film is changed to particles containing the cycloolefin resin a3.

(Manufacture of optical film 13 with functional layer) In the above-mentioned production of the optical film 1, the optical film 13 was produced in the same manner except that the type of the functional layer-forming coating liquid was changed to the functional layer-forming coating liquid b6.

(Manufacture of optical film 14) In the production of the optical film 11 described above, the optical film 14 is produced in the same manner except that the type of particles used to form the pre-stretched film is changed to particles containing the cycloolefin resin a5.

Furthermore, in the obtained optical films 1 to 14, the thickness of the cycloolefin resin base material was 60 μm. Furthermore, in the obtained optical films 1 to 7, 9, 10, and 13, the thickness of the functional layer (hardened layer) was 1 μm.

Furthermore, the prescription and manufacturing method of the optical film obtained above are shown in the following Table 1 and the following Table 2.

＜Manufacturing of polarizing plates＞ [Manufacture of polarizer] A polyvinyl alcohol film with a thickness of 70 μm was swollen with water at 35°C. The obtained film was immersed in an aqueous solution composed of 0.075g of iodine, 5g of potassium iodide and 100g of water for 60 seconds, and then immersed in a 45°C aqueous solution of 3g of potassium iodide, 7.5g of boric acid and 100g of water. The obtained film was uniaxially stretched at a stretching temperature of 55°C and a stretching ratio of 5 times. The uniaxially stretched film was washed with water and then dried to obtain a polarizer with a thickness of 20 μm.

[Preparation of active energy ray curing adhesive] After mixing each of the following components, defoaming is performed to prepare an active energy ray-curable adhesive. Furthermore, triarylsonium hexafluorophosphate is blended as a 50% propylene carbonate solution, and the following represents the solid content of triarylsonium hexafluorophosphate: 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate: 45 parts by mass Epolead (registered trademark) GT-301 (alicyclic epoxy resin manufactured by Daicel Co., Ltd.): 40 parts by mass 1,4-butanediol diglycidyl ether: 15 parts by mass Triarylsonium hexafluorophosphate: 2.3 parts by mass 9,10-dibutoxyanthracene: 0.1 parts by mass 1,4-diethoxynaphthalene: 2.0 parts by mass.

[Manufacturing of polarizing plates] (Manufacture of polarizing plate 1) The optical film 1 produced as above is prepared, and the surface on the functional layer (hardened layer) side is subjected to corona discharge treatment. Furthermore, the conditions for the corona discharge treatment were set to a corona output intensity of 2.0kW and a production line speed of 18m/min. Next, the active energy ray curable adhesive obtained above was applied to the corona discharge treated surface of the optical film using a bar coater until the film thickness after curing became about 3 μm. The obtained adhesive layer is bonded to one side of the polarizer produced above.

On the other hand, as another optical film, a cellulose triacetate film (KC4UA, manufactured by Konica Minolta Co., Ltd., film thickness 40 μm) was prepared, and corona was applied to one surface in the same manner as above. handle. Next, the active energy ray curable adhesive obtained above was applied to the corona discharge treated surface of KC4UA using a bar coater so that the film thickness after curing became about 3 μm. The obtained adhesive layer is bonded to the other side of the polarizer with optical film 1 produced above to obtain a laminate.

Then, an ultraviolet irradiation device with a conveyor belt attached to both sides of the bonded laminate (the lamp uses a D bulb manufactured by Fusion UV Systems) is irradiated with ultraviolet rays in such a manner that the cumulative light intensity becomes 750mJ/cm ² to allow the bonding to proceed. The agent layer is hardened to produce the polarizing plate 1 .

(Production of Polarizing Plate 2~14) The polarizing plates 2 to 14 were produced in the same manner as the polarizing plate 1 except that the optical film 1 was changed into the optical films 2 to 14 .

Furthermore, the surfaces of the optical films 2 to 14 that are subjected to corona discharge treatment and coated with the active energy ray curable adhesive obtained above are the functional layer (hardened layer) side of the film having a functional layer (hardened layer). The surface refers to any side of the film in a film that does not have a functional layer (hardened layer).

＜Manufacturing of liquid crystal display device＞ (Manufacture of liquid crystal display device 1) Attached to the observer side (viewing side) surface (front) and the light source side (rear) of the liquid crystal unit of the Sony Corporation Type 40 LCD monitor (BRAVIA (registered trademark) X1) in VA mode The polarizing plates are peeled off respectively. Furthermore, the polarizing plate 1 prepared above is bonded to the light source side surface (rear surface) and the observer side (viewing side) surface (front surface) of the obtained liquid crystal cell using an acrylic transparent adhesive, respectively, to produce a liquid crystal display. Device 1. The polarizing plates are bonded in such a way that the transmission axis of the polarizing plate after bonding is consistent with the transmission axis of the polarizing plate that was originally bonded. In addition, the polarizing plate is bonded so that the optical film 1 is on the liquid crystal cell side with respect to the polarizer. More specifically, the polarizing plate is attached to the front surface of the liquid crystal unit so that the polarizer of the optical film 1 becomes the side of the liquid crystal unit relative to the polarizing plate, and the cellulose triacetate film of other optical films is opposite to the polarizing plate. The polarizer will be placed on the viewing side. In addition, the polarizing plate is attached to the back side of the liquid crystal cell so that the optical film 1 faces the polarizer of the polarizing plate and becomes the side of the liquid crystal cell, and the cellulose triacetate film of other optical films faces the polarizer of the polarizing plate. It will be done on the side of the light source.

(Manufacture of liquid crystal display devices 2~14) The liquid crystal display devices 2 to 14 are produced in the same manner as the liquid crystal display device 1 except that the polarizing plate 1 is changed into the polarizing plates 2 to 14 .

＜Evaluation＞ [Refractive index of optical films and polarizers] According to JIS K0062-1992, a multi-wavelength Abbe refractometer (trade name: DR-M2, manufactured by ATAGO Co., Ltd.) was used to measure the refractive index at the nD:D line (589nm) at 25°C. The refractive index of films 1 to 14 and the polarizer obtained above. Furthermore, 1-bromonaphthalene was used as the measurement intermediate liquid. Furthermore, regarding the polarizing plates 1 to 14, the difference in refractive index between the optical films 1 to 14 and the polarizer (refractive index of the optical film - the refractive index of the polarizer) was calculated. The results are shown in Table 3 below. In addition, regarding the optical film with a functional layer, the entire film is measured as one film.

In addition, for the optical film with a functional layer, the refractive index of the functional layer alone and the refractive index of the cycloolefin resin base material alone were measured. The refractive index of the functional layer alone is determined by forming the functional layer into a thin film, and measuring the refractive index of the obtained film using the above method. In addition, the refractive index of the cycloolefin resin base material alone is measured by the above-mentioned method and the refractive index of the base material used in the production of the optical film obtained above. Furthermore, as explained above, from the viewpoint of optical scattering, the refractive index of the functional layer is preferably 0.002 to 0.008 lower than the refractive index of the base layer.

[Haze of optical films] Measure the haze (%) of the optical films 1 to 14 obtained above. The haze was measured in accordance with JIS K 7136:2000 using a haze meter (NDH4000, manufactured by Nippon Denshoku Industries Co., Ltd.). Here, among the optical films, for films having a functional layer (hardened layer), the value measured from the functional layer side is used. The results are shown in Table 3 below.

[RMS granularity] Regarding the liquid crystal display devices 1 to 14 obtained above, the RMS particle size of the display device was calculated as follows. The results are shown in Table 3 below.

(Step 1) Obtaining the image Camera: Sony Co., Ltd. (SONY) α7sII, Lens: Use Canon Co., Ltd. (Canon) EF 70-200mm F2.8L IS II USM, use ISO 25,600, F 2.8 in a dark room, and take pictures at a position tilted 10° from the display surface toward the viewing side to obtain the above-mentioned LCD The display surface when the display device displays black.

The display surface is photographed by rotating +45°, +135°, +225° (-- 135°C) and +315° (-45°) in each direction at a position tilted 10° from the display surface toward the viewing side. At this time, the distance between the position of the display surface of the liquid crystal display device as a reference for photography and the camera was set to 50 cm.

(Step 2) Analyze the obtained image Calculate the RMS granularity from the photographic image according to the following sequence of operations: 1. Use free software (imageJ) to read the two-dimensional (plane) data of the obtained photographic image; 2. Set a 2.8cm×4cm rectangular evaluation area in the actual photographic image; 3. Grayscale conversion using free software (ImageJ); 4. Perform background correction on the read two-dimensional data in the aforementioned evaluation area; 5. Calculate the RMS granularity from the standard deviation σ of the gray scale value (pixel value) under gray scale. The standard deviation σ is regarded as the RMS granularity of the display image at the measurement angle (the angle along the display surface) (the RMS granularity at a specific angle); 6. Calculate +45°, +135°, +225° (-135°), and +315 when rotating along the display surface with respect to the absorption axis direction of the polarizer of the polarizer arranged on the viewing side of the liquid crystal display device. The average of the RMS granularity (RMS granularity at a specific angle) of the display image photographed at a position tilted 10° from the display surface toward the viewing side in each direction of ° (-45°) is used as the RMS granularity of the display device.

Here, the free software ImageJ refers to ImageJ1.32S produced by Wayne Rasband.

Furthermore, background correction is performed when, for example, the right half and the left half of the image have the same brightness, but are output as different brightnesses, or are output as a result of gradually becoming brighter from the left to the right of the image. Correction, use polynomials to approximate the concentration gradient and mathematically eliminate the concentration gradient.

Use the following method to calculate the standard deviation σ of the gray-scale value under the gray scale: Taking N data of gray-scale values x ₁ , x ₂ ,..., x _N as the parent group, it is calculated by the following mathematical formula (I) Find the summed average (parent average) m of the parent group.

[Number 3]

Next, using the mother average m obtained above, the dispersion σ ² is obtained by the following mathematical formula (II).

[Number 4]

The positive square root of this dispersion σ ² is defined as the standard deviation σ.

(uneven display) Camera: Sony Co., Ltd. (SONY) α7sII, Lens: Canon Co., Ltd. (Canon) EF 70-200mm F2.8L IS II USM was used to observe and photograph the display surface when the display device displayed black at ISO 25,600 and F 2.8 in a dark room. The display surface is photographed from the display surface in the direction of +45° rotation with respect to the absorption axis direction of the polarizer of the polarizing plate disposed on the viewing side (observer side, front side) of the liquid crystal display device. Perform with the face tilted 10° toward the viewing side. At this time, the distance between the position of the display surface of the liquid crystal display device as a reference for photography and the camera was set to 50 cm. Furthermore, based on the following criteria, confirm the presence and extent of unevenness (roughness) visually or on the display image. Furthermore, when the following evaluation results are A to C, it is judged that the display unevenness is within a practically acceptable level. The results are shown in Table 3 below. Moreover, high-sensitivity cameras refer to the above-mentioned cameras and lenses: ≪Evaluation criteria≫ A: The image taken by the camera and then subjected to the gradation process can be visually confirmed, and uneven display cannot be confirmed; B: When visually confirming the image taken by the camera and then applying gradation processing, slight display unevenness can be confirmed; C: Slight display unevenness can be confirmed by visual inspection; D: Obvious display unevenness was visually confirmed.

Furthermore, the position photographed at the time of this measurement is rotated +45° along the display surface with respect to the absorption axis direction of the polarizer of the polarizing plate placed on the viewing side, and is tilted 10° from the display surface toward the viewing side. Part of the photographic portrait is shown in Figures 5 and 6. Specifically, a photographic image of the liquid crystal display device 7 is shown in FIG. 5 , and a photographic image of the liquid crystal display device 13 is shown in FIG. 6 .

(Production stability) Production stability was evaluated by manufacturing a plurality of the above-obtained liquid crystal display devices and evaluating their brightness unevenness. Specifically, the observation was performed in a dark room with a black display. With respect to the direction of the absorption axis of the polarizer of the polarizing plate placed on the viewing side (observer side, front side) of the liquid crystal display device, the +45° rotation direction along the display surface is tilted 45° from the display surface toward the viewing side. Observe the position visually to confirm whether there is uneven brightness. The evaluation is based on the number of units with observed unevenness among 2,000 units. The evaluation criteria are as follows. When the following evaluation result is A or B, the production stability is judged to be at a practically acceptable level. The results are shown in Table 3 below: ≪Evaluation criteria≫ A: The number of liquid crystal display devices for which uneven brightness was visually confirmed is less than 10 units/2000 units. B: The number of liquid crystal display devices for which uneven brightness is visually confirmed is more than 10 and less than 19/2000 units C: The number of liquid crystal display devices for which uneven brightness is visually confirmed is more than 20 units/2,000 units.

Furthermore, based on the results of FIGS. 5 and 6 , it was confirmed that the liquid crystal display device 7 having the polarizing plate 7 of the present invention significantly reduced display unevenness compared with the liquid crystal display device 13 having the polarizing plate 13 of the comparative example. Furthermore, regarding liquid crystal display devices having other polarizing plates, it was also confirmed that the liquid crystal display device having the polarizing plate of the present invention was significantly reduced compared to the liquid crystal display device having the polarizing plate of the comparative example.

Furthermore, according to the results in Table 3 above, in the liquid crystal display devices 1 to 10 having the polarizing plates 1 to 10 of the present invention, the refractive index difference between the optical film containing the cycloolefin resin base material and the polarizer is between 0 and less than 0.02. Within the range, the RMS particle size is 0.30~1.34, preferably within the range of 0.30~1.30, and it is confirmed that the display unevenness is reduced at this time. Furthermore, it was confirmed that the liquid crystal display device having the polarizing plate had little variation in brightness unevenness between display devices and had excellent production stability. On the other hand, it was confirmed that in the liquid crystal display devices 11 to 14 of the polarizing plates 11 to 14 of the comparative examples, the refractive index difference and the RMS particle size of the optical film and the polarizer including the cycloolefin resin base material were outside the above ranges, respectively. When the display unevenness occurs, it becomes obvious.

This patent application is based on Japanese Patent Application No. 2021-011903 filed on January 28, 2021, and the entire disclosure is incorporated herein by reference.

1:Display surface O: Reference position (the position used as the reference position for photography) X: X direction (the direction orthogonal to the absorption axis of the polarizer of the polarizing plate on the viewing side) Y: Y direction (the direction of the absorption axis of the polarizer of the viewing side polarizing plate) Z: Z direction (normal direction of the display surface) a: The absorption axis direction of the polarizer of the viewing side polarizing plate L: A straight line showing the direction of "a position tilted 10° from the display surface toward the viewing side" L(45): A straight line showing the direction of the absorption axis of the polarizer of the polarizing plate on the viewing side, along the +45° rotation of the display surface at a position tilted 10° from the display surface toward the viewing side. 10:LCD display device 30:LCD unit 50: 1st polarizing plate 51: 1st polarizer 53: Optical film (F1) 55: Optical film (F2) 551:Cyclic olefin resin base material 552:Functional layer 70: 2nd polarizing plate 71: 2nd polarizer 73: Optical film (F3) 731:Cyclic olefin resin base material 732:Functional layer 75: Optical film (F4) 90:Light source (backlight)

[Fig. 1] A schematic diagram illustrating the photographic position used to evaluate the RMS grain size. [Fig. 2] is used to explain the rotation of the polarizer along the display surface with respect to the absorption axis direction of the polarizer (viewing side polarizing plate) arranged on the viewing side (observer side, front side) of the display cell (display cell) Schematic diagram of the photographic position used to evaluate the RMS grain size in the +45° direction. [Fig. 3] A schematic diagram showing an example of the basic structure of a liquid crystal display device according to an embodiment of the present invention. [Fig. 4] A schematic diagram showing another example of the basic structure of a liquid crystal display device according to an embodiment of the present invention. [Fig. 5] A photographic image of display unevenness of the liquid crystal display device 7 according to the embodiment of the present invention. [Fig. 6] A photographic image of display unevenness of the liquid crystal display device 13 of the comparative example of the present invention.

30:LCD unit

50: 1st polarizing plate

51: 1st polarizer

53: Optical film (F1)

55: Optical film (F2)

70: 2nd polarizing plate

71: 2nd polarizer

73: Optical film (F3)

75: Optical film (F4)

90:Light source (backlight)

551:Cyclic olefin resin base material

552:Functional layer

731:Cyclic olefin resin base material

732:Functional layer

Claims (14)

A display device having a polarizing plate and a display device unit, wherein the polarizing plate has a polarizer and an optical film, the optical film has at least a base material, the base material contains at least a cycloolefin resin, and the optical film and the polarizer The refractive index difference satisfies the following formula (1); formula (1) 0≦ (refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer) <0.02; when making the aforementioned display device display black, when viewing from the display surface The RMS granularity of the displayed image photographed at a side tilt of 10° is 0.30~1.34. For example, the display device of claim 1, wherein the aforementioned RMS granularity is 0.30~1.30. The display device of claim 1 or 2, wherein the aforementioned optical film further has an organic layer. The display device of claim 3, wherein the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (2); Formula (2) 0.001≦ (refractive index of the aforementioned optical film – refractive index of the aforementioned polarizer)≦ 0.015; the aforementioned functional layer contains acrylic resin or urethane resin, and particles. The display device of claim 3, wherein the functional layer includes an acrylic resin, and the acrylic resin includes urethane acrylic. acid ester resin. The display device of claim 1 or 2, wherein the display device unit is a vertical alignment (VA) liquid crystal display device unit. The display device of claim 1 or 2, wherein at least one of the aforementioned polarizing plates is arranged on the viewing side of the display unit of the aforementioned display device unit. A polarizing plate having a polarizer and an optical film, wherein the optical film has at least a base material, the base material contains at least a cycloolefin resin, and the refractive index difference between the optical film and the polarizer satisfies the following formula (1) ; Formula (1) 0≦ (refractive index of the aforementioned optical film - refractive index of the aforementioned polarizer) <0.02; When the aforementioned polarizing plate is assembled in a display device, and the aforementioned display device displays black, when the display surface The RMS granularity of the display image photographed at a position tilted 10° toward the viewing side is 0.30~1.34. Such as the polarizing plate of claim 8, wherein the aforementioned RMS particle size is 0.30~1.30. The polarizing plate of claim 8 or 9, wherein the aforementioned optical film further has an organic layer. Such as the polarizing plate of claim 10, wherein the refractive index difference between the aforementioned optical film and the aforementioned polarizer satisfies the following formula (2); Formula (2) 0.001≦ (refractive index of the aforementioned optical film – refractive index of the aforementioned polarizer)≦ 0.015; The aforementioned functional layer contains acrylic resin or urethane resin, and particles. The polarizing plate of claim 10, wherein the functional layer includes an acrylic resin, and the acrylic resin includes a urethane acrylate resin. The polarizing plate of claim 8 or 9, wherein the display device has a display device unit, and the display device unit is a vertical alignment (VA) liquid crystal display device unit. The polarizing plate of claim 8 or 9, wherein the display device has a display device unit and is assembled on the viewing side of the display unit of the display device unit.