JP6324947B2 - Image display device - Google Patents

Description

  The present invention relates to an optical film, and a polarizing plate and an image display device using the optical film.

  In a 3D image display device that displays a stereoscopic image, an optical device that converts linearly polarized light into circularly polarized light in order to prevent display characteristics from deteriorating with respect to face rotation or to separate a right eye image and a left eye image. A member may be used.

  As such an optical member, for example, Patent Document 1 discloses that “a transparent film substrate, an alignment layer formed on the transparent film substrate, and a surface formed on the surface of the alignment layer with different refractive indexes. A phase retardation film having a retardation layer containing a rod-like compound having a directivity, wherein the alignment layer is formed with fine irregularities so that the rod-like compound can be arranged in one direction. A first alignment region and a second alignment region in which fine irregularities are formed so that the rod-shaped compound can be arranged in a direction orthogonal to the arrangement direction in the first alignment region are arranged in a pattern on the surface And a fine concavo-convex shape formed on at least one surface of the first alignment region or the second alignment region is a striped line concavo-convex structure. Over emissions retardation film. "Is disclosed.

  Further, Patent Document 2 states that “an optical film formed of an alignment film containing at least one photoacid generator on a transparent support and a composition mainly composed of a liquid crystal having a polymerizable group”. An optical film having at least an isotropic layer, wherein the optically anisotropic layer includes a first retardation region and a second retardation region having mutually different in-plane slow axis directions, and the first and second retardation regions. An optical film characterized in that the retardation regions are patterned optically anisotropic layers arranged alternately in the plane. "

JP 2012-073515 A JP 2012-150428 A

However, when the optical members described in Patent Documents 1 and 2 were examined, when an acetylcellulose-based resin was used as a transparent film substrate or a transparent support (hereinafter simply referred to as “support”), the support was used. Depending on the manufacturing environment of the body, the type of additive, the type of optically anisotropic layer, and the manufacturing conditions, alignment defects may occur in the retardation layer (patterned optically anisotropic layer).
On the other hand, when a polyester resin (especially polyethylene terephthalate resin) is used as a support, it has excellent properties such as high durability compared to an acetyl cellulose resin, but has a high birefringence, so it is oblique. There was a problem that rainbow unevenness (rainbow-like color spots) occurred when viewed.

  Then, this invention makes it a subject to provide the optical film which suppressed generation | occurrence | production of the orientation defect and the rainbow nonuniformity, the polarizing plate using the same, and an image display apparatus.

As a result of intensive studies to achieve the above-mentioned problems, the inventors of the present invention include a polyethylene terephthalate resin, the in-plane retardation (Re) is in a specific range, and the in-plane retardation (Re) and the thickness direction retardation. By using a support having a specific ratio of (Rth) to (Rth) (Re / Rth), it was found that an optical film in which the occurrence of alignment defects and rainbow unevenness was suppressed could be produced, and the present invention was completed.
That is, it has been found that the above object can be achieved by the following configuration.

[1] An optical film having a support and an optically anisotropic layer provided on the support,
The optically anisotropic layer is a patterned optically anisotropic layer in which regions having two or more different optical properties are formed in a pattern,
The support contains a polyethylene terephthalate resin, the in-plane retardation (Re) is 3000 nm to 30000 nm, and the ratio (Re / Rth) between the in-plane retardation (Re) and the thickness direction retardation (Rth) is An optical film that is 0.2 to 1.5.
[2] The optical film according to [1], wherein the ratio (Re / Rth) is 0.7 to 1.2.
[3] Further, it has a hard coat layer,
The optical film according to [1] or [2], wherein the hard coat layer is provided on the optically anisotropic layer.
[4] The optical film according to [3], wherein the hard coat layer is an antiglare hard coat layer.
[5] The optical film according to any one of [1] to [4], wherein the content of the ultraviolet absorber in the support is 0.1% by mass or less of the mass of the support.

[6] A polarizing plate having an optically anisotropic layer, a support, and a polarizer in this order,
A laminate having an optically anisotropic layer and a support is composed of the optical film according to any one of [1] to [5],
A polarizing plate, wherein the polarizer is provided such that the optical axis of the polarizer is parallel or perpendicular to the optical axis of the support.

[7] An image display device comprising a polarizing plate having an optically anisotropic layer, a support, and a polarizer in this order,
The image display apparatus whose polarizing plate is a polarizing plate as described in [6].

  ADVANTAGE OF THE INVENTION According to this invention, the optical film which suppressed generation | occurrence | production of the orientation defect and the rainbow nonuniformity, the polarizing plate using the same, and an image display apparatus can be provided.

FIG. 1 is a schematic cross-sectional view showing an example of the optical film of the present invention. FIG. 2 is a schematic cross-sectional view showing another example of the optical film of the present invention. FIG. 3 is a schematic cross-sectional view showing another example of the optical film of the present invention. FIG. 4 is a schematic cross-sectional view showing an example of the polarizing plate of the present invention. FIG. 5 is a schematic cross-sectional view showing an example of the image display device of the present invention. 6A to 6C are schematic front views showing examples of the patterned optical anisotropic layer, and FIGS. 6A and 6B are stripe-shaped patterned optical anisotropic layers. FIG. 6C shows a mode in which the pattern optical anisotropic layer is arranged in a lattice pattern.

Hereinafter, the present invention will be described in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
Next, terms used in this specification will be described.

In-plane retardation (hereinafter also abbreviated as “Re”) is defined as the biaxial refractive index anisotropy (ΔNxy = | Nx−Ny |) in the film plane and the thickness d (nm) of the film. This parameter is defined by the product (ΔNxy × d), and is represented by Re = | Nx−Ny | × d.
Here, the biaxial refractive index anisotropy (ΔNxy) was determined by the following method. Using two polarizing plates, the orientation axis direction of the film was determined, and a 2 cm × 1 cm rectangle was cut out so that the orientation axis directions were perpendicular to each other, and used as a measurement sample. For this sample, the biaxial refractive index (Nx, Ny) perpendicular to each other and the refractive index (Nz) in the thickness direction were determined by an Abbe refractometer (NAGO-4T, measurement wavelength 589 nm, manufactured by Atago Co., Ltd.). The absolute value (| Nx−Ny |) of the refractive index difference between the axes was defined as the refractive index anisotropy (ΔNxy). The thickness d (nm) of the film was measured using an electric micrometer (K-402, manufactured by Anritsu Corporation), and the unit was converted to nm. In-plane retardation (Re) was determined from the product (ΔNxy × d) of refractive index anisotropy (ΔNxy) and film thickness d (nm).

Thickness direction retardation (hereinafter also abbreviated as “Rth”) is retardation in the film thickness direction, and two birefringences ΔNxz (= | Nx−Nz |) when viewed from the cross section in the film thickness direction. ΔNyz (= | Ny−Nz |) is a parameter representing the average retardation obtained by multiplying the thickness d of the film, and is represented by Rth = {(Nx + Ny) / 2−Nz} × d.
Here, Rth is determined by calculating the average value of (ΔNxz × d) and (ΔNyz × d) by obtaining Nx, Ny, Nz and film thickness d (nm) by the same measurement method as Re. The longitudinal retardation (Rth) was determined.

  In the present specification, the angle (for example, an angle such as “90 °”) and the relationship (for example, “orthogonal”, “parallel”, “same direction”, “crossing at 45 °”, etc.) The range of errors allowed in the technical field to which the invention belongs is included. At this time, the allowable error means, for example, that the angle is within a range of strict angle ± 10 ° or less, and the error from the strict angle is preferably 5 ° or less, More preferably, it is 3 ° or less.

1. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is an optical film having a support and a patterned optically anisotropic layer provided on the support, and the support includes a polyethylene terephthalate resin (hereinafter also abbreviated as “PET”). In-plane retardation (hereinafter also abbreviated as “Re”) is 3000 nm to 30000 nm, and the ratio (Re / Rth) between Re and thickness direction retardation (hereinafter also abbreviated as “Rth”) is 0. It relates to an optical film that is 2 to 1.5.

As described above, the present inventors have found that by using the support having the above-described configuration, an optical film in which the occurrence of alignment defects and rainbow unevenness is suppressed is obtained.
The above findings can be said to be an unexpected finding in consideration of the fact that general PET has a high Re and is inferior in visibility, and thus could not be used as a support or a polarizer protective film.
In addition, the present inventors presume the reason why such an effect is obtained as follows. That is, since the support containing PET has less solvent penetration, it can suppress bleed-out of the components (for example, additives and monomer components), and thus alignment defects in the optical anisotropic layer. Is thought to decrease. Further, by using a support having an extremely high Re and a ratio of Re to Rth (Re / Rth) of a specific ratio, rainbow unevenness is suppressed, and the optical axis of the polarizer and the support This is considered to be because the adjustment with the optical axis becomes easy and an optical film that does not cancel the optical characteristics of the optically anisotropic layer can be obtained.

1 to 3 show schematic cross-sectional views of examples of the optical film in the present invention.
In addition, the figure in this invention is a schematic diagram, and the relationship of the thickness of each layer, a positional relationship, etc. do not necessarily correspond with an actual thing. The same applies to the following figures.
An optical film 10 shown in FIG. 1 has a support 12 and a patterned optically anisotropic layer 14.
Moreover, the optical film 10 shown in FIG. 2 has the support body 12, the pattern optical anisotropic layer 14, and the arbitrary hard-coat layers 16 in this order. Note that the hard coat layer 16 may include an ultraviolet absorber (not shown) described later.
Furthermore, the optical film 10 shown in FIG. 3 has the support body 12, the pattern optical anisotropic layer 14, the arbitrary ultraviolet absorption layer 18, and the arbitrary hard-coat layer 16 in this order.

2. Polarizing plate The present invention also relates to a polarizing plate using the optical film of the present invention.
The polarizing plate of the present invention is a polarizing plate having an optically anisotropic layer, a support, and a polarizer in this order, and the laminate having the optically anisotropic layer and the support is the polarizing plate of the present invention. An optical film is used, and the polarizer is provided such that the optical axis of the polarizer is parallel or perpendicular to the optical axis of the support.
Here, “a laminate having an optically anisotropic layer and a support” includes a laminate consisting of only an optically anisotropic layer and a support, and any of the hard coat layers and ultraviolet absorbing layers described above. This refers to a laminate.

FIG. 4 shows a schematic cross-sectional view of an example of the polarizing plate of the present invention.
A polarizing plate 20 shown in FIG. 4 includes an optional hard coat layer 16, a patterned optically anisotropic layer 14, a support 12, a polarizer (viewing side) 22, and an optional polarizer protective film 24. It has in order. The hard coat layer 16, the patterned optical anisotropic layer 14, and the support 12 are constituted by the optical film 10 shown in FIG.
Here, the support 12 and the polarizer (viewing side) 22 may be bonded to each other via an adhesive or an adhesive (not shown). In addition, you may arrange | position the polarizer protective film which is not illustrated in the surface in which the optical film 10 (support 12) of the polarizer (viewing side) 22 is arrange | positioned as needed.

3. Image display apparatus TECHNICAL FIELD This invention relates also to the image display apparatus using the optical film or polarizing plate of this invention.
The image display device of the present invention has the polarizing plate of the present invention, the optical film of the present invention is disposed as the outermost surface (viewing side), and has an image display panel.

FIG. 5 shows a schematic cross-sectional view of a liquid crystal display device which is an example of the image display device of the present invention.
In the liquid crystal display device 30 shown in FIG. 5, the polarizing plate 20 of the present invention is disposed so that the optical film 10 of the present invention becomes the outermost surface (viewing side).
Further, polarizer protective films 36 and 38 are respectively disposed on the front and back surfaces of the polarizer (backlight side) 34. In addition, about the polarizer protective films 34 and 36, it is good also as an optical compensation film according to the drive mode of a liquid crystal cell.
Here, each layer may be bonded through an adhesive or an adhesive (not shown).

[Optical film]
Hereinafter, various members used in the optical film of the present invention will be described in detail.

<Support>
As described above, the support in the optical film of the present invention contains a polyethylene terephthalate resin, has an in-plane retardation (Re) of 3000 nm to 30000 nm, and an in-plane retardation (Re) and a thickness direction retardation (Rth). ) (Re / Rth) is 0.2 to 1.5.

Here, Re is preferably 5000 nm or more, and more preferably 6000 nm or more, from the reason that the occurrence of alignment defects and rainbow unevenness in the optical film can be further suppressed.
Further, Re is preferably 30000 nm or less, and more preferably 20000 nm or less, from the viewpoint of the handleability (particularly thickness) of the optical film.

  On the other hand, the ratio of Re to Rth (Re / Rth) is preferably from 0.5 to 1.5, because the occurrence of alignment defects and rainbow unevenness in the optical film can be further suppressed. More preferably, it is 7-1.5. Further, since the upper limit value of the ratio (Re / Rth) is preferably 1.2 or less because it is easy to manufacture, the ratio (Re / Rth) is further 0.7 to 1.2. preferable.

  In the present invention, the thickness of the support is not particularly limited, but is preferably 15 μm to 300 μm and more preferably 25 μm to 200 μm from the viewpoint of the handleability of the optical film.

  Furthermore, in the present invention, for the reason that the orientation defects of the optical film can be further suppressed, the support, particularly, the side of the support on which the optically anisotropic layer (orientation film in the case of having an orientation film) is provided. The content of the ultraviolet absorber in the vicinity of the surface (for example, the surface layer to a depth region of about 5 μm) is preferably 0.1% by mass or less of the mass of the support, and is preferably not substantially contained. .

  The manufacturing method of the said support body is not specifically limited, It can manufacture according to the manufacturing method of a general polyester film. For example, after melting a polyethylene terephthalate resin and stretching the non-oriented polyethylene terephthalate extruded into a sheet shape in the machine direction at a temperature equal to or higher than the glass transition temperature using the difference in the speed of the roll, The method of extending | stretching and performing heat processing is mentioned.

The production method of the support will be specifically described. The longitudinal (running direction) stretching temperature and the transverse (width direction) stretching temperature are preferably 80 ° C. to 130 ° C., and 90 ° C. to 120 ° C. More preferred.
The longitudinal draw ratio is preferably 1.0 to 5.0 times, and more preferably 1.0 to 4.0 times. Further, the transverse draw ratio is preferably 1.0 to 5.0 times, and more preferably 1.0 to 4.5 times.
Here, in order to control Re of the support within the above-described range, it is preferable to control the ratio of the longitudinal draw ratio and the transverse draw ratio. In addition, since it becomes difficult to raise Re when the difference of the draw ratio of length and width is too small, it is not preferable.
Also, setting the stretching temperature low is a preferable measure for increasing the Re of the support. In the subsequent heat treatment, the treatment temperature is preferably 100 ° C to 250 ° C, particularly preferably 180 ° C to 245 ° C.

  In order to suppress the Re fluctuation of the support, it is preferable that the thickness unevenness of the support is small. Since the stretching temperature and the stretching ratio have a great influence on the thickness unevenness of the support, it is necessary to optimize the film forming conditions from the viewpoint of the thickness unevenness. In particular, when the longitudinal draw ratio is lowered to increase Re, the longitudinal thickness unevenness may be deteriorated. Since there is a region where the vertical thickness unevenness becomes very bad in a specific range of the draw ratio, it is desirable to set the film forming conditions outside this range.

  The thickness unevenness of the support of the present invention is preferably 5.0% or less, more preferably 4.5% or less, still more preferably 4.0% or less, and 3.0% or less. It is particularly preferred that

As described above, the Re of the support can be controlled within the above-described range by appropriately setting the stretching ratio, the stretching temperature, and the thickness of the support.
For example, the higher the draw ratio, the lower the drawing temperature, and the thicker the support, the higher the Re. Conversely, the lower the draw ratio, the higher the drawing temperature, and the thinner the film, the easier it is to obtain low Re. However, when the thickness of the support is increased, the thickness direction retardation is likely to increase. Therefore, it is desirable that the thickness of the support is appropriately set within the above range. In addition to controlling the retardation, it is necessary to set final film forming conditions in consideration of physical properties necessary for processing.

<Pattern optical anisotropic layer>
The patterned optically anisotropic layer in the optical film of the present invention is a layer in which regions having two or more different optical characteristics are formed in a pattern.
Here, the regions having two or more different optical characteristics are preferably two or more retardation regions in which at least one of the in-plane slow axis direction and the in-plane retardation is different.

  The optical film of the present invention may have two or more retardation regions having a retardation of about λ / 4 because the patterned optically anisotropic layer can be approximated to accurate circularly polarized light in an image display device. Preferably, Re (550) is preferably 110 nm to 165 nm, more preferably 115 nm to 150 nm, and particularly preferably 120 nm to 145 nm as the phase difference in each region.

  In addition, the optical film of the present invention has a pattern optically anisotropic layer having an in-plane slow axis direction and a plane in the image display device because it can respectively produce clockwise circularly polarized light and counterclockwise circularly polarized light. An optically anisotropic layer in which at least one of the inner retardations includes a first retardation region and a second retardation region which are different from each other, and the first and second retardation regions are alternately arranged in the plane. It is preferable.

6A to 6C are schematic front views of examples of the patterned optically anisotropic layer.
For example, the patterned optical anisotropic layer 14 shown in FIGS. 6A to 6C includes a first retardation region 14a and a second retardation region 14b that are different from each other in at least one of the in-plane slow axis directions. And the 1st phase difference area | region 14a and the 2nd phase difference area | region 14b are pattern optically anisotropic layers arrange | positioned alternately in a surface. The first retardation region 14a and the second retardation region 14b have in-plane slow axes a and b that are orthogonal to each other.
Further, as shown in FIGS. 6A and 6B, the first retardation region 14a and the second retardation region 14b in the optical anisotropic layer 14 are alternately arranged in a stripe pattern as shown in FIGS. The aspect arrange | positioned may be sufficient, and as shown in FIG.6 (C), the aspect which arrange | positioned the rectangular pattern in the grid | lattice form may be sufficient.
In addition, when utilizing the polarizing plate of this invention mentioned later as a circularly-polarizing plate, the 1st phase difference area | region 14a and the 2nd phase difference area | region of the pattern optical anisotropic layer 14 shown to FIG. 6 (A)-(C). The in-plane slow axes a and b in each region 14b and the absorption axis of the polarizer are arranged so as to intersect at 45 °. With this configuration, it is possible to separate the circularly polarized images for the right eye and the left eye.

  The thickness of the patterned optically anisotropic layer is not particularly limited, but is preferably 0.1 μm to 10 μm, and more preferably 0.5 μm to 5 μm.

The patterned optically anisotropic layer preferably contains a liquid crystalline compound.
Examples of a method for forming an optically anisotropic layer containing a liquid crystal compound include a method of fixing the liquid crystal compound in an aligned state. In this case, as a method for immobilizing the liquid crystalline compound, a method of immobilizing by using a liquid crystalline compound having an unsaturated double bond (polymerizable group) as the liquid crystalline compound is preferably exemplified. . The optically anisotropic layer may have a single layer structure or a laminated structure.
The kind of unsaturated double bond contained in the liquid crystal compound is not particularly limited, and a functional group capable of addition polymerization reaction is preferable, and a polymerizable ethylenically unsaturated group or a ring polymerizable group is preferable. More specifically, a (meth) acryloyl group, a vinyl group, a styryl group, an allyl group, etc. are mentioned preferably, and a (meth) acryloyl group is more preferable.

In general, liquid crystal compounds can be classified into a rod-shaped type and a disk-shaped type based on their shapes. In addition, there are low and high molecular types, respectively. Polymer generally refers to a polymer having a degree of polymerization of 100 or more (Polymer Physics / Phase Transition Dynamics, Masao Doi, 2 pages, Iwanami Shoten, 1992). In the present invention, any liquid crystal compound can be used, but a rod-like liquid crystal compound or a discotic liquid crystal compound (discotic liquid crystal compound) is preferably used. Two or more kinds of rod-like liquid crystalline compounds, two or more kinds of disc-like liquid crystalline compounds, or a mixture of a rod-like liquid crystalline compound and a disk-like liquid crystalline compound may be used. In order to fix the liquid crystalline compound, it is more preferable to use a rod-like liquid crystalline compound having a polymerizable group or a discotic liquid crystalline compound, and the liquid crystalline compound has 2 polymerizable groups in one molecule. It is more preferable to have the above. In the case where the liquid crystal compound is a mixture of two or more, it is preferable that at least one liquid crystal compound has two or more polymerizable groups in one molecule.
As the rod-like liquid crystalline compound, for example, those described in claim 1 of JP-T-11-53019 and paragraphs [0026] to [0098] of JP-A-2005-289980 can be preferably used. As the tick liquid crystal compound, for example, those described in paragraphs [0020] to [0067] of JP-A-2007-108732 and paragraphs [0013] to [0108] of JP-A-2010-244038 are preferably used. However, it is not limited to these.

  In order to set the retardation in the patterned optically anisotropic layer to about λ / 4, the alignment state of the liquid crystal compound may be controlled. At this time, when the rod-like liquid crystalline compound is used, it is preferable to fix the rod-like liquid crystalline compound in a horizontally aligned state. When the discotic liquid crystalline compound is used, the discotic liquid crystalline compound is vertically aligned. It is preferable to fix in a state. In the present invention, “the rod-like liquid crystal compound is horizontally aligned” means that the director of the rod-like liquid crystal compound and the layer surface are parallel, and “the discotic liquid crystal compound is vertically aligned” means the discotic liquid crystal This means that the disk surface and layer surface of the active compound are perpendicular. It is not strictly required to be horizontal or vertical, but each means a range of ± 20 ° from an accurate angle. It is preferably within ± 5 °, more preferably within ± 3 °, even more preferably within ± 2 °, and most preferably within ± 1 °.

  Moreover, in order to make a liquid crystalline compound into a horizontal alignment and a vertical alignment state, you may use the additive (alignment control agent) which accelerates | stimulates a horizontal alignment and a vertical alignment. Various known additives can be used as the additive.

Examples of the method for forming the patterned optically anisotropic layer described above include the following preferred embodiments, but the present invention is not limited to these, and various known methods can be used.
The first preferred embodiment utilizes a plurality of actions for controlling the alignment of the liquid crystal compound, and then eliminates any action by an external stimulus (heat treatment, etc.) to make the predetermined alignment control action dominant. Is the method. As the above method, for example, the liquid crystalline compound is brought into a predetermined alignment state by the combined action of the alignment control ability by the alignment film and the alignment control ability of the alignment controller added to the liquid crystalline compound, and then fixed. After forming one phase difference region, any action (for example, action by the alignment control agent) disappears by external stimulation (heat treatment, etc.), and the other orientation control action (action by the alignment film) dominates. Thus, another alignment state is realized and fixed to form the other retardation region. Details of this method are described in paragraphs [0017] to [0029] of JP 2012-008170 A, the contents of which are incorporated herein by reference.

  A 2nd suitable aspect is an aspect using a pattern orientation film. In this embodiment, pattern alignment films having different alignment control capabilities are formed, a liquid crystalline compound is disposed thereon, and the liquid crystalline compound is aligned. The liquid crystalline compounds achieve different alignment states depending on the alignment control ability of the pattern alignment film. By fixing each alignment state, the pattern of the 1st and 2nd phase difference area | region is formed according to the pattern of an alignment film. The pattern alignment film can be formed using a printing method, mask rubbing for the rubbing alignment film, mask exposure for the photo alignment film, or the like. A method using a printing method is preferable in that large-scale equipment is not required and manufacturing is easy. Details of this method are described in paragraphs [0166] to [0181] of JP2012-032661, and the contents thereof are incorporated herein by reference.

  As a third preferred embodiment, for example, a photoacid generator is added to the alignment film. In this example, a photoacid generator is added to the alignment film, and pattern exposure exposes a region where the photoacid generator is decomposed to generate an acidic compound and a region where no acid compound is generated. The photoacid generator remains almost undecomposed in the non-irradiated portion, and the interaction between the alignment film material, the liquid crystal compound, and the alignment control agent added as necessary dominates the alignment state, and the liquid crystal compound Is oriented in a direction whose slow axis is perpendicular to the rubbing direction. When the alignment film is irradiated with light and an acidic compound is generated, the interaction is no longer dominant, the rubbing direction of the rubbing alignment film controls the alignment state, and the liquid crystalline compound has its slow axis parallel to the rubbing direction. To parallel orientation. As the photoacid generator used in the alignment film, a water-soluble compound is preferably used. Examples of photoacid generators that can be used include Prog. Polym. Sci. , 23, 1485 (1998). As the photoacid generator, pyridinium salts, iodonium salts and sulfonium salts are particularly preferably used. Details of this method are described in Japanese Patent Application No. 2010-289360, the contents of which are incorporated herein by reference.

<Hard coat layer>
In the optical film of the present invention, a hard coat layer is preferably provided on the optically anisotropic layer.
A hard-coat layer is a layer arrange | positioned on the said optically anisotropic layer, and plays the role which protects an optically anisotropic layer from the impact from the outside. Further, as will be described later, an ultraviolet absorber can be added to the hard coat layer, and in that case, it can also serve to impart light resistance to the optical film.
The optical film having the hard coat layer has a pencil hardness (JIS K5400) of preferably H or higher, more preferably 2H or higher, and still more preferably 3H or higher.

  There may be one hard coat layer or a plurality of hard coat layers. When there are a plurality of hard coat layers, the total thickness of all hard coat layers is preferably in the following range.

  The thickness of the hard coat layer is not particularly limited, but is preferably 3 μm to 30 μm, more preferably 5 μm to 30 μm, and even more preferably 10 μm to 30 μm from the viewpoint of the balance between brittleness and light resistance of the optical film.

  In the present invention, the hard coat layer is an ultraviolet ray because it can suppress degradation of the liquid crystalline compound of the optically anisotropic layer on the inner side (transparent support side) than the hard coat layer by ultraviolet rays and suppress deterioration of crosstalk. An absorbent is preferably included.

A well-known thing can be used as a ultraviolet absorber. Examples thereof include benzotriazole-based, benzophenone-based, salicylic acid phenyl ester-based, and triazine-based ultraviolet absorbers.
Examples of the benzotriazole ultraviolet absorber include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (2H-benzotriazol-2-yl) -p-cresol, and 2- (2H-benzotriazole-2). -Yl) -4,6-di-tert-pentylphenol, 2- (2′-hydroxy-5′methacryloxyethylphenyl) -2H-benzotriazole and the like.
Examples of benzophenone-based ultraviolet absorbers include 2-hydroxy-4-octoxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4′-chlorobenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, 2,2-dihydroxy-4,4′-dimethoxybenzophenone and the like can be mentioned.
Examples of the salicylic acid phenyl ester ultraviolet absorber include pt-butylphenyl salicylic acid ester.
Examples of triazine ultraviolet absorbers include 2,4-diphenyl-6- (2-hydroxy-4-methoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-). Ethoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-propoxyphenyl) -1,3,5-triazine, 2,4-diphenyl- (2-hydroxy-4-) Butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2- Hydroxy-4-hexyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-octyloxyphenyl) -1,3,5-triazine 2,4-diphenyl-6- (2-hydroxy-4-dodecyloxyphenyl) -1,3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-benzyloxyphenyl) -1 , 3,5-triazine, 2,4-diphenyl-6- (2-hydroxy-4-butoxyethoxyphenyl) -1,3,5-triazine, and the like.

Among these UV absorbers, the use of a compound having a functional group (preferably an unsaturated double bond) polymerizable with the polymerizable monomer of the hard coat layer can increase the hardness of the hard coat layer, It is preferable in terms of suppression and improvement of durability. That is, it is preferable that the matrix polymer constituting the hard coat layer is bonded to the ultraviolet absorber.
Examples of the compound having such a polymerizable functional group include 2-hydroxybenzophenone derivatives and 2-hydroxyphenylbenzotriazole derivatives.
Specific examples of 2-hydroxybenzophenone derivatives include 2-hydroxy-4-acryloyloxybenzophenone, 2-hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-4- (2-acryloyloxy) ethoxybenzophenone, 2-hydroxy- 4- (2-methacryloyloxy) ethoxybenzophenone, 2-hydroxy-4- (2-methyl-2-acryloyloxy) ethoxybenzophenone and the like can be mentioned.
Specific examples of 2-hydroxyphenylbenzotriazole derivatives include 2- [2′-hydroxy-5- (methacryloyloxy) ethylphenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxy). ) Phenyl] benzotriazole, 2- [2′-hydroxy-5 ′-(acryloyloxy) phenyl] benzotriazole, 2- [2′-hydroxy-3′-t-butyl-5 ′-(methacryloyloxy) phenyl] Benzotriazole, 2- [2′-hydroxy-3′-methyl-5 ′-(acryloyloxy) phenyl] benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxypropyl) phenyl] -5-chloro Benzolitriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxye) L) phenyl] benzotriazole, 2- [2′-hydroxy-5 ′-(acryloyloxyethyl) phenyl] benzotriazole, 2- [2′-hydroxy-3′-t-butyl-5 ′-(methacryloyloxyethyl) ) Phenyl] benzotriazole, 2- [2′-hydroxy-3′-methyl-5 ′-(acryloyloxyethyl) phenyl] benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxypropyl) phenyl] -5-chlorobenzotriazole, 2- [2'-hydroxy-5 '-(acryloyloxybutyl) phenyl] -5-methylbenzotriazole, [2-hydroxy-3-tert-butyl-5- (acryloyloxyethoxy) Carbonylethyl) phenyl] benzotriazole and the like. Examples of commercially available products include “RUVA-93” (2- [2′-hydroxy-5 ′-(methacryloyloxy) ethylphenyl] -2H-benzotriazole) manufactured by Otsuka Chemical Co., Ltd.
Two or more kinds of ultraviolet absorbers having these polymerizable functional groups can be used. Moreover, the ultraviolet absorber which has a polymerizable functional group, and the ultraviolet absorber which does not have a polymerizable functional group can also be used together.

  The content of the ultraviolet absorber in the hard coat layer is 1 with respect to the mass of the hard coat layer from the viewpoints of adhesion between the hard coat layer and the optically anisotropic layer, hardness of the hard coat layer, and light resistance. It is preferably at least 1% by mass, more preferably 1% by mass to 5% by mass, still more preferably 1% by mass to 4% by mass, and particularly preferably 1% by mass to 3% by mass. .

In the present invention, the hard coat layer has an antiglare hard coat layer (antiglare hard coat) because an antireflection function can be imparted when an optical film is used on the surface of the image display device. Layer).
Examples of the antiglare hard coat layer are disclosed in JP-A-10-206603, JP-A-2002-243906, JP-A-2007-264113, and the like.
The hard coat layer may contain translucent particles for imparting antiglare properties. Specific examples of the translucent particles include particles of inorganic compounds such as silica particles and TiO ₂ particles; resin particles such as acrylic particles, crosslinked acrylic particles, polystyrene particles, crosslinked styrene particles, melamine resin particles, and benzoguanamine resin particles; Is preferred. Of these, crosslinked styrene particles, crosslinked acrylic particles, and silica particles are preferred.
The shape of the light-transmitting particles can be either spherical or irregular.
In addition, in the hard coat layer, in order to control the cohesiveness of the translucent particles, an embodiment using a smectite clay organic composite obtained by intercalating a quaternary ammonium salt to the smectite clay is also preferable. Is exemplified.

The difference in refractive index between the translucent particles and the matrix polymer (binder) constituting the hard coat layer is preferably less than 0.05, more preferably 0.001 to 0.030 as an absolute value. More preferably, it is 0.001-0.020. When the difference in refractive index between the light-transmitting particles and the matrix polymer in the hard coat layer is less than 0.05, the light refraction angle by the light-transmitting particles becomes small, the scattered light does not spread to a wide angle, and optical anisotropic This is preferable because it does not have a deteriorating effect such as depolarization of transmitted light through the conductive layer.
The average particle diameter of the translucent particles is preferably 0.3 μm to 12 μm, more preferably 0.5 μm to 8 μm, still more preferably 0.5 μm to 6 μm, and most preferably 1.0 μm to 6 μm. By setting the refractive index difference and the particle size within the above ranges, the light scattering angle distribution does not spread to a wide angle, and it is difficult to cause blurring of characters on the display and a decrease in contrast.

  The material for forming the hard coat layer is not particularly limited, but the composition for forming the hard coat layer containing a compound having an unsaturated double bond, a polymerization initiator, a solvent, and an optional additive is optically anisotropic. It is preferably formed by coating, drying and curing directly on the layer or via another layer. Hereinafter, each component of the hard coat layer will be described.

(Compound having an unsaturated double bond)
The composition for forming a hard coat layer preferably contains a compound having an unsaturated double bond in order to covalently bond with the optically anisotropic layer. The compound having an unsaturated double bond can function as a binder, and is preferably a polyfunctional monomer having two or more polymerizable unsaturated groups. The polyfunctional monomer having two or more polymerizable unsaturated groups can function as a curing agent, and can improve the strength and scratch resistance of the coating film. The number of polymerizable unsaturated groups is more preferably 3 or more. These monomers may be used in combination of a monofunctional or bifunctional monomer and a trifunctional or higher functional monomer.

Examples of the compound having an unsaturated double bond include compounds having a polymerizable functional group such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Among them, a (meth) acryloyl group and —C (O ) OCH = CH ₂ is preferred. Particularly preferably, a compound containing three or more (meth) acryloyl groups in one molecule described below can be used.
Specific examples of the compound having a polymerizable unsaturated bond include (meth) acrylic acid diesters of alkylene glycol, (meth) acrylic acid diesters of polyoxyalkylene glycol, and (meth) acrylic acid diesters of polyhydric alcohol. , (Meth) acrylic acid diesters of ethylene oxide or propylene oxide adducts, epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, and the like.

  Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. For example, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , Pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, EO modified trimethylolpropane tri (meth) acrylate, PO modified trimethylolpropane tri (meth) acrylate, EO modified Tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate Rate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol hexa (meth) acrylate, 1,2,3-chlorohexane tetramethacrylate, polyurethane polyacrylate, polyester polyacrylate, caprolactone modified tris And (acryloxyethyl) isocyanurate.

  The content of the compound having an unsaturated double bond in the composition for forming a hard coat layer provides a sufficient polymerization rate and imparts hardness and the like, so that the total solid content in the composition for forming a hard coat layer is 50 mass% or more is preferable, 60 mass%-99 mass% is more preferable, 70 mass%-99 mass% is still more preferable, 80 mass%-99 mass% is especially preferable.

(Polymerization initiator)
Next, the photopolymerization initiator that can be contained in the composition for forming a hard coat layer will be described.
As photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, Examples include fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, and coumarins. Specific examples of photopolymerization initiators, preferred embodiments, commercial products, and the like are described in paragraphs [0133] to [0151] of JP-A-2009-098658, and are also suitably used in the present invention.
The content of the photopolymerization initiator in the composition for forming the hard coat layer is sufficiently high to polymerize the polymerizable compound contained in the composition for forming the hard coat layer and is small enough not to increase the starting point excessively. For the reason of setting the amount, 0.5% by mass to 8% by mass is preferable and 1% by mass to 5% by mass is more preferable with respect to the total solid content in the composition for forming a hard coat layer.

(solvent)
Next, the solvent that can be contained in the hard coat layer forming composition will be described.
As the solvent, various solvents can be used in consideration of the solubility of the monomer, the dispersibility of the light-transmitting particles, the drying property during coating, and the like. Examples of the organic solvent include dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole, phenetole, dimethyl carbonate, Methyl ethyl carbonate, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate , Methyl propionate, ethyl propionate, γ-ptyrolactone, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-methyl Methyl alcohol such as xylethanol, 2-propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, ethyl acetoacetate, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexyl Alcohol, isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol , Hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, Examples thereof include ruene and xylene, and these can be used alone or in combination of two or more.
It is preferable to use a solvent such that the solid content of the hard coat layer forming composition is in the range of 20% by mass to 80% by mass, more preferably 30% by mass to 75% by mass, and still more preferably 40%. It is mass%-70 mass%.

<Other layers>
The optical film of the present invention may contain other layers other than the above-described support, optically anisotropic layer, and optional hard coat layer.
For example, the optical film of the present invention may form an ultraviolet absorbing layer containing 5% by mass or more, preferably 10% by mass or more of the ultraviolet absorber between the hard coat layer and the optically anisotropic layer.
Here, the material for forming the ultraviolet absorber layer is not particularly limited, and specific examples thereof include polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polycarbonate resins; polymethyl Acrylic resins such as methacrylate; Polyamide resins; Polyimide resins; Polyvinyl chloride resins; Polyphenylene sulfide resins; Polyethersulfone resins; Polyethylene sulfide resins; Polyphenylene ether resins; Styrene resins; Cellulosic resin; and the like.
In addition, the thing similar to what was demonstrated as an arbitrary component contained in a hard-coat layer can be used for an ultraviolet absorber.

In the optical film of the present invention, an alignment film for forming an optically anisotropic layer may be formed between the support and the optically anisotropic layer.
The alignment film generally contains a polymer as a main component. The polymer material for alignment film is described in many documents, and many commercially available products can be obtained. The polymer material used is preferably polyvinyl alcohol or polyimide, and derivatives thereof. In particular, modified or unmodified polyvinyl alcohol is preferred. For the alignment film that can be used in the present invention, refer to the modified polyvinyl alcohol described in WO01 / 88574A1, page 43, line 24 to page 49, line 8, and patent No. 3907735, paragraphs [0071] to [0095]. be able to.
The thickness of the alignment film is preferably thin. However, it is possible to form an optically anisotropic layer with a uniform thickness by imparting alignment ability to form an optically anisotropic layer and relaxing the surface irregularities of the support. A certain amount of thickness is necessary from the standpoint of doing. Specifically, the thickness of the alignment film is preferably 0.01 μm to 10 μm, more preferably 0.01 μm to 1 μm, and still more preferably 0.01 μm to 0.5 μm.
In the present invention, it is also preferable to use a photo-alignment film. Although it does not specifically limit as a photo-alignment film | membrane, The thing as described in Paragraphs [0024]-[0043] of WO2005 / 096041 and the brand name LPP-JP265CP by Rolitechnologies can be used.

Furthermore, the optical film of the present invention may have an antireflection layer on the hard coat layer. The antireflection layer is preferably an antiglare layer, but may be a low refractive index layer, a medium refractive index layer, or a high refractive index layer.
An anti-glare layer contains a binder and translucent particles for imparting anti-glare properties, and surface irregularities are formed by the projections of the translucent particles themselves or by projections formed of an aggregate of a plurality of particles. It is preferable that it is a thing. The kind of translucent particle | grains is as the above-mentioned.

The refractive index of the high refractive index layer is preferably 1.70 to 1.74, more preferably 1.71 to 1.73. The refractive index of the middle refractive index layer is adjusted to be a value between the refractive index of the low refractive index layer and the refractive index of the high refractive index layer. The refractive index of the medium refractive index layer is preferably 1.60 to 1.64, and more preferably 1.61 to 1.63. The low refractive index layer preferably has a refractive index of 1.30 to 1.47. In the case of a multilayer thin film interference type antireflection film (medium refractive index layer / high refractive index layer / low refractive index layer), the refractive index of the low refractive index layer is preferably 1.33-1.38. More preferably, it is 35-1.37.
The high refractive index layer, medium refractive index layer, and low refractive index layer are formed by a chemical vapor deposition (CVD) method or a physical vapor deposition (PVD) method, particularly a vacuum vapor deposition method or a sputtering method, which is a kind of physical vapor deposition method, and an inorganic substance. Although a transparent oxide thin film can be used, a method using all wet coating is preferred.
As the high refractive index layer, the medium refractive index layer, and the low refractive index layer, those described in paragraphs [0197] to [0211] of JP-A-2009-98658 can be used.

Furthermore, the optical film of the present invention contains at least one of a polyester resin, a polyurethane resin, or a polyacrylic resin as a main component on at least one surface of the optical film of the present invention in order to improve adhesiveness with a polarizer described later. It is preferable to have an easy adhesion layer. Here, the “main component” refers to a component that is 50% by mass or more of the solid components constituting the easy-adhesion layer.
The coating solution used for forming the easy-adhesion layer is preferably an aqueous coating solution containing at least one of a water-soluble or water-dispersible copolymerized polyester resin, an acrylic resin, and a polyurethane resin. Examples of these coating solutions include water-soluble or water-dispersible co-polymers disclosed in Japanese Patent No. 3567927, Japanese Patent No. 3589232, Japanese Patent No. 3589233, Japanese Patent No. 3900191, and Japanese Patent No. 4150982. Examples thereof include a polymerized polyester resin solution, an acrylic resin solution, and a polyurethane resin solution.

The easy-adhesion layer can be obtained by applying the coating solution on one or both sides of a uniaxially stretched film in the longitudinal direction, drying at 100 ° C. to 150 ° C., and further stretching in the transverse direction. The coating amount of the final adhesive layer is preferably managed to ^{0.05g / m 2 ~0.20g / m 2} . When the coating amount is 0.05 g / m ² or more, adhesion between polarizing obtained polarizer is improved, when the coating amount is 0.20 g / m ² or more, blocking resistance is improved. When providing an easily bonding layer on both surfaces of a polyester film, the application quantity of an easily bonding layer on both surfaces may be the same or different, and can be independently set within the above range.

  It is preferable to add particles to the easy-adhesion layer in order to impart easy slipperiness. It is preferable to use particles having an average particle size of 2 μm or less. When the average particle diameter of the particles is 2 μm or less, the particles are difficult to drop off from the coating layer. As particles to be included in the easy adhesion layer, for example, titanium oxide, barium sulfate, calcium carbonate, calcium sulfate, silica, alumina, talc, kaolin, clay, calcium phosphate, mica, hectorite, zirconia, tungsten oxide, lithium fluoride, Examples include inorganic particles such as calcium fluoride, and organic polymer particles such as styrene, acrylic, melamine, benzoguanamine, and silicone. These may be added alone to the easy-adhesion layer, or may be added in combination of two or more.

  Moreover, a well-known method can be used as a method of apply | coating a coating liquid. For example, reverse roll coating method, gravure coating method, kiss coating method, roll brush method, spray coating method, air knife coating method, wire bar coating method, pipe doctor method, etc. can be mentioned. Or it can carry out in combination.

In addition, the measurement of the average particle diameter of said particle | grain is performed with the following method.
Take a picture of the particles with a scanning electron microscope (SEM), and at a magnification such that the size of one smallest particle is 2 mm to 5 mm, the maximum diameter of 300 to 500 particles (between the two most distant points) The average value is taken as the average particle diameter.

〔Polarizer〕
Hereinafter, various members used for the polarizing plate of the present invention will be described in detail.
Here, the polarizing plate of the present invention has the optical film of the present invention described above and a polarizer provided on the support side of the optical film, and the polarizer has an optical axis of the support whose optical axis is the support. It is provided so as to be parallel or perpendicular to the axis.

<Polarizer>
As the polarizer, a general polarizer can be used. As a polarizer that can be used in the present invention, for example, a polarizer made of a polyvinyl alcohol film or the like dyed with iodine or a dichroic dye can be used.

<Adhesive layer>
An adhesive layer may be disposed between the optically anisotropic layer and the polarizer. As the pressure-sensitive adhesive layer used for laminating the optically anisotropic layer and the polarizer, for example, the ratio of the storage elastic modulus G ′ and the loss elastic modulus G ″ measured with a dynamic viscoelasticity measuring apparatus (tan δ = G ″ / G ′) represents a material having a ratio of 0.001 to 1.5, and includes a so-called pressure-sensitive adhesive, a substance that easily creeps, and the like. Examples of the adhesive that can be used in the present invention include, but are not limited to, a polyvinyl alcohol-based adhesive.

(Image display device)
Hereinafter, various members used in the image display device of the present invention will be described in detail.
Here, the image display device of the present invention has the polarizing plate of the present invention described above, and the above-described optical film of the present invention is disposed as the outermost surface (viewing side) and has an image display panel.

<Image display panel>
In the present invention, the image display panel in the image display device is not particularly limited. For example, a liquid crystal panel including a liquid crystal layer, an organic EL display panel including an organic EL layer, a plasma display panel, Also good. For any aspect, various possible configurations can be employed.
Moreover, in the aspect which has the polarizer for image display on the visual recognition side of an image display panel, such as a transmissive mode liquid crystal panel, the polarizer is utilized as a polarizer in the polarizing plate of this invention, and the polarizing plate of this invention is used. Also preferred is an embodiment that doubles as a viewing-side polarizing plate in the image display device.

<Liquid crystal cell>
The liquid crystal cell used in the image display device of the present invention is preferably VA mode, OCB mode, IPS mode, or TN mode, but is not limited thereto.
In a TN mode liquid crystal cell, rod-like liquid crystal molecules are substantially horizontally aligned when no voltage is applied, and are twisted and aligned at 60 ° to 120 °. The TN mode liquid crystal cell is most frequently used as a color TFT liquid crystal display device, and is described in many documents.
In a VA mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially vertically when no voltage is applied. The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2-). 176625) (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Proceed) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle. ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVIVAL mode liquid crystal cells (announced at LCD International 98). Moreover, any of PVA (Patterned Vertical Alignment) type, optical alignment type (Optical Alignment), and PSA (Polymer-Stained Alignment) may be used. Details of these modes are described in JP-A-2006-215326 and JP-T-2008-538819.
In an IPS mode liquid crystal cell, rod-like liquid crystal molecules are aligned substantially parallel to the substrate, and the liquid crystal molecules respond in a planar manner when an electric field parallel to the substrate surface is applied. The IPS mode displays black when no electric field is applied, and the absorption axes of the pair of upper and lower polarizing plates are orthogonal. JP-A-10-54982, JP-A-11-202323, and JP-A-9-292522 are methods for reducing leakage light at the time of black display in an oblique direction and improving a viewing angle using an optical compensation sheet. No. 11-133408, No. 11-305217, No. 10-307291, and the like.

  Hereinafter, the present invention will be described in more detail based on examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the following examples.

(Preparation of polyester resin 1)
First, the esterification reactor was heated, and when the temperature reached 200 ° C., the following composition was injected, and the following catalyst was added while stirring.
Next, the pressure was raised and the pressure esterification reaction was performed under the conditions of a gauge pressure of 0.34 MPa and 240 ° C., then the esterification reaction vessel was returned to normal pressure, and 0.014 part by mass of phosphoric acid was added. . Furthermore, it heated up to 260 degreeC over 15 minutes, and 0.012 mass part of trimethyl phosphate was added. Then, after 15 minutes, dispersion treatment was performed with a high-pressure disperser. After 15 minutes, the obtained esterification reaction product was transferred to a polycondensation reaction can and subjected to polycondensation reaction at 280 ° C. under reduced pressure.
After completion of the polycondensation reaction, it is filtered through a NASRON filter with a 95% cut diameter of 5 μm, extruded in a strand form from a nozzle, and cooled and solidified using cooling water that has been filtered (nominal pore diameter: 1 μm or less) in advance. And cut into pellets to obtain polyester resin 1.
<Composition>
-86.4 parts by mass of terephthalic acid-64.6 parts by mass of ethylene glycol <Catalyst>
-Antimony trioxide 0.017 mass part-Magnesium acetate tetrahydrate 0.064 mass part-Triethylamine 0.16 mass part

(Preparation of polyester resin 2)
10 parts by weight of the dried UV absorber (2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazinon-4-one) and 90 parts by weight of polyester resin 1 containing no particles A polyester resin 2 containing an ultraviolet absorber was obtained using a kneading extruder.

(Preparation of polyester resin 3)
In the first esterification reactor, 4.7 tons of high-purity terephthalic acid and 1.8 tons of ethylene glycol are mixed for 90 minutes to form a slurry, and continuously at a flow rate of 3800 kg / h. Supplied to. Further, an ethylene glycol solution of antimony trioxide was continuously supplied, and the reaction was carried out at a reaction vessel temperature of 250 ° C. with stirring and an average residence time of about 4.3 hours. At this time, antimony trioxide was continuously added so that the amount of Sb added was 150 ppm in terms of element.
This reaction product was transferred to a second esterification reaction vessel, and reacted with stirring at a temperature in the reaction vessel of 250 ° C. and an average residence time of 1.2 hours. To the second esterification reaction tank, an ethylene glycol solution of magnesium acetate and an ethylene glycol solution of trimethyl phosphate are continuously supplied so that the added amount of Mg and the added amount of P are 65 ppm and 35 ppm in terms of element, respectively. did.

The esterification reaction product obtained above was continuously supplied to the first polycondensation reaction tank, and with stirring, the reaction temperature was 270 ° C. and the reaction tank internal pressure was 20 torr (2.67 × 10 ⁻³ MPa). The polycondensation reaction was carried out with a residence time of about 1.8 hours.
Further, the mixture was transferred to the second double condensation reaction tank, and while stirring in this reaction tank, the reaction tank temperature was 276 ° C., the reaction tank pressure was 5 torr (6.67 × 10 ⁻⁴ MPa), and the residence time was about 1.2 hours. The polycondensation reaction was performed under the conditions.
Subsequently, it was further transferred to the third triple condensation reaction tank. In this reaction tank, the reaction tank temperature was 278 ° C., the reaction tank pressure was 1.5 torr (2.0 × 10 ⁻⁴ MPa), and the residence time was 1.5 hours. The polycondensation reaction was carried out under the following conditions.
Next, the obtained reaction product was discharged into cold water in a strand shape, cooled and solidified with cooling water that had been filtered (nominal pore diameter: 1 μm or less) in advance, cut into pellets, and polyester resin 3 Got.

(Preparation of polyester resin 4)
10 parts by weight of the dried UV absorber (2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazinon-4-one) and 90 parts by weight of polyester resin 3 were mixed, A polyester resin 4 containing an ultraviolet absorber was obtained using a kneading extruder.

<Preparation of support (PET1)>
As a raw material of the support, the above-mentioned pellet molded product of polyester resin 1 was dried under reduced pressure (1 Torr) at 135 ° C. for 6 hours, and then supplied to an extruder and dissolved at 285 ° C.
Next, the polymer after dissolution is filtered through a filter material of stainless sintered body (nominal pore size 10 μm particles 95% cut), extruded into a sheet form from the die, and then cast at a surface temperature of 30 ° C. using an electrostatic application casting method. The film was wound around a drum and solidified by cooling to prepare an unstretched film.
Then, this unstretched film is guided to a tenter stretching machine, and the end of the film is gripped by a clip, guided to a hot air zone at a temperature of 125 ° C., and stretched 1.0 times in the running direction and 4.0 times in the width direction. did. Next, while maintaining the width stretched in the width direction, the film was treated at a temperature of 225 ° C. for 30 seconds and further subjected to a relaxation treatment of 3% in the width direction to obtain a uniaxially oriented PET film (PET1) having a film thickness of about 50 μm. It was. The Re, Rth and Re / Rth of the obtained PET1 are shown in Table 1 below.

<Preparation of support (PET2)>
An unstretched film prepared by the same method as PET 1 is heated to 105 ° C. using a heated roll group and an infrared heater, and then 4.0 times in the running direction and a width direction in the roll group having a difference in weekly speed. The film was stretched 1.0 times to obtain a uniaxially oriented PET film (PET2) having a film thickness of about 100 μm. The Re, Rth and Re / Rth of the obtained PET2 are shown in Table 1 below.

<Preparation of support (PET3)>
An unstretched film produced by the same method as PET 1 is heated to 105 ° C. using a heated roll group and an infrared heater, and then 1.0 times in the running direction and a width direction in the roll group having a weekly speed difference. The film was stretched 3.5 times to obtain a uniaxially oriented PET film (PET3) having a film thickness of about 75 μm. The Re, Rth and Re / Rth of the obtained PET3 are shown in Table 1 below.

<Preparation of support (PET4)>
After drying 90 parts by mass of the above-mentioned polyester resin 1 pellets and 10 parts by mass of the polyester resin 2 pellets containing an ultraviolet absorber as a raw material of the support at 135 ° C. for 6 hours under reduced pressure (1 Torr), It supplied to the extruder and melt | dissolved at 285 degreeC.
Next, the polymer after dissolution is filtered through a filter material of stainless sintered body (nominal pore size 10 μm particles 95% cut), extruded into a sheet form from the die, and then cast at a surface temperature of 30 ° C. using an electrostatic application casting method. The film was wound around a drum and solidified by cooling to prepare an unstretched film.
After that, this unstretched film is guided to a tenter stretching machine, and the end of the film is held by a clip, guided to a hot air zone at a temperature of 125 ° C., and stretched 1.5 times in the running direction and 4.0 times in the width direction. did. Next, while maintaining the width stretched in the width direction, the film was treated at a temperature of 225 ° C. for 30 seconds and further subjected to a relaxation treatment of 3% in the width direction to obtain a uniaxially oriented PET film (PET4) having a film thickness of about 50 μm. It was. The Re, Rth and Re / Rth of the obtained PET4 are shown in Table 1 below.

<Preparation of support (PET5)>
An unstretched film produced by the same method as PET 4 is heated to 105 ° C. using a heated roll group and an infrared heater, and then 3.3 times in the running direction and a width direction in the roll group having a weekly speed difference. The film was stretched 4.0 times to obtain a uniaxially oriented PET film (PET5) having a film thickness of about 75 μm. The Re, Rth and Re / Rth of the obtained PET5 are shown in Table 1 below.

<Preparation of support (PET6)>
As raw materials for the support, 90 parts by mass of the above-mentioned polyester resin 1 pellets and 10 parts by mass of the polyester resin 2 pellets containing an ultraviolet absorber were dried under reduced pressure (1 Torr), and then the extruder 2 (intermediate) The polyester resin 1 pellets were dried by a conventional method and supplied to the extruder 1 (for the outer layer I layer and the outer layer III layer), respectively, and dissolved at 285 ° C.
Next, the two types of polymer after dissolution are each filtered through a filter medium made of a sintered stainless steel (nominal pore size 10 μm particles 95% cut), laminated in a two-type three-layer confluence block, and extruded into a sheet form from the die. Thereafter, the film was wound around a casting drum having a surface temperature of 30 ° C. using an electrostatic application casting method, and solidified by cooling to produce an unstretched film. At this time, the discharge amount of each extruder was adjusted so that the thickness ratio of the I layer, the II layer, and the III layer was 10:80:10.
Then, this unstretched film is guided to a tenter stretching machine, and the end of the film is gripped by a clip, guided to a hot air zone at a temperature of 125 ° C., and stretched 1.0 times in the running direction and 4.0 times in the width direction. did. Next, while maintaining the width stretched in the width direction, the film was treated at a temperature of 225 ° C. for 30 seconds and further subjected to a relaxation treatment of 3% in the width direction to obtain a uniaxially oriented PET film (PET6) having a film thickness of about 100 μm. It was. The Re, Rth and Re / Rth of the obtained PET6 are shown in Table 1 below.

<Production of support (PET7)>
After heating an unstretched film produced by the same method as PET 6 to 105 ° C. using a heated roll group and an infrared heater, the roll group having a difference in weekly speed is 2.0 times in the running direction and in the width direction. The film was stretched 4.0 times to obtain a uniaxially oriented PET film (PET7) having a film thickness of about 50 μm. The Re, Rth and Re / Rth of the obtained PET 7 are shown in Table 1 below.

<Preparation of support (PET8)>
After heating an unstretched film produced by the same method as PET 1 to 105 ° C. using a heated roll group and an infrared heater, the roll group with a difference in weekly speed is 3.4 times in the running direction and in the width direction. The film was stretched 4.0 times to obtain a uniaxially oriented PET film (PET8) having a film thickness of about 40 μm. The Re, Rth and Re / Rth of the obtained PET8 are shown in Table 1 below.

<Preparation of support (PET9)>
As a raw material of the support, the above-mentioned pellet molded product of the polyester resin 3 was dried to a water content of 20 ppmpp and then supplied to the hopper 1 of the shaft kneading extruder 1. Polyester resin 3 was melted at 300 ° C., filtered with a filter medium (nominal pore size: 20 μm) under the following extrusion conditions, and extruded from a die.
The molten resin was extruded from the die under the conditions that the pressure fluctuation was 1% and the temperature distribution of the molten resin was 2%. The molten resin extruded from the die was wound around a cast drum having a surface temperature of 25 ° C. using an electrostatic application method and solidified by cooling to prepare an unstretched polyester film.
Thereafter, the unstretched polyester film was guided to a tenter stretching machine, and the preheating temperature was set to 90 ° C. while the end of the film was held with a clip, and the film was heated to a stretchable temperature. The preheated unstretched polyester film was stretched at 90 ° C. by 1.0 times in the running direction and 4.3 times in the width direction.
Next, the stretched polyester film was treated at 180 ° C. for 15 seconds, subjected to a 2% relaxation treatment at 170 ° C., and cooled at a cooling temperature of 50 ° C. As described above, a uniaxially stretched polyester film (PET9) having a thickness of 100 μm was obtained. Re, Rth and Re / Rth of the obtained PET 9 are shown in Table 1 below.

<Preparation of support (PET10)>
As a raw material of the support, after drying 90 parts by mass of the above-mentioned pellet molded product of the polyester resin 3 and 10 parts by mass of the polyester resin 4 containing the ultraviolet absorber to a moisture content of 20 ppm or less, It put into the hopper 1 of the shaft kneading extruder 1, melted to 300 ° C. with the extruder 1, filtered with a filter medium (nominal pore diameter: 20 μm) under the following extrusion conditions, and extruded from a die.
The molten resin was extruded from the die under the conditions that the pressure fluctuation was 1% and the temperature distribution of the molten resin was 2%. The molten resin extruded from the die was wound around a cast drum having a surface temperature of 25 ° C. using an electrostatic application method and solidified by cooling to prepare an unstretched polyester film.
Then, this unstretched polyester film was stretched under the same conditions as PET9 to obtain a uniaxially stretched polyester film (PET10) having a thickness of 100 μm. Re, Rth and Re / Rth of the obtained PET 10 are shown in Table 1 below.

<Preparation of support (PET11)>
As a raw material for the support, 90 parts by mass of a molded pellet of polyester resin 3 and 10 parts by mass of polyester resin 4 containing an ultraviolet absorber were dried to a moisture content of 20 ppm or less, and then uniaxially kneaded with a diameter of 50 mm. It put into the hopper 1 of the extruder 1 and melted at 300 ° C. with the extruder 1 (intermediate layer II layer). Further, after drying the polyester resin 3 to a moisture content of 20 ppm or less, the polyester resin 3 was put into a hopper 2 of a single screw kneading extruder 2 having a diameter of 30 mm and melted at 300 ° C. by the extruder 2 (outer layer I layer, outer layer III layer) ). The two polymers were filtered with a filter medium (nominal pore size: 20 μm) under the following extrusion conditions, respectively, and then the polymer extruded from the extruder 1 in the two-kind three-layer merging block became an intermediate layer (II layer). The polymer extruded from the extruder 2 was laminated so as to be outer layers (I layer and III layer), and extruded from a die into a sheet.
The molten resin was extruded from the die under the conditions that the pressure fluctuation was 1% and the temperature distribution of the molten resin was 2%. The molten resin extruded from the die was wound around a cast drum having a surface temperature of 25 ° C. using an electrostatic application method and solidified by cooling to prepare an unstretched polyester film.
At this time, the discharge amount of each extruder was adjusted so that the ratio of the thicknesses of the I layer, the II layer, and the III layer was 10:80:10.
The obtained unstretched polyester film was horizontally stretched under the same conditions as PET 9 to produce a uniaxially stretched polyester film (PET11) having a thickness of 100 μm. The Re, Rth and Re / Rth of the obtained PET 11 are shown in Table 1 below.

<Preparation of support (PET12)>
After heating an unstretched film produced by the same method as PET 11 to 105 ° C. using a heated roll group and an infrared heater, the roll group having a weekly speed difference is 0.7 times in the running direction and in the width direction. The film was stretched 4.3 times to obtain a uniaxially oriented PET film (PET12) having a film thickness of about 50 μm. Re, Rth and Re / Rth of the obtained PET 12 are shown in Table 1 below.

<Preparation of support (PET13)>
After heating an unstretched film produced by the same method as PET 11 to 105 ° C. using a heated roll group and an infrared heater, the roll group having a weekly speed difference is 4.3 times in the running direction and in the width direction. The film was stretched 4.3 times to obtain a uniaxially oriented PET film (PET13) having a film thickness of about 180 μm. Re, Rth and Re / Rth of the obtained PET 13 are shown in Table 1 below.

<Support (TAC1)>
(1) Preparation of core layer dope 1 A core layer dope 1 having the following composition was prepared.
────────────────────────────────
Composition of core layer dope 1 ────────────────────────────────
Cellulose acetate (acetylation degree 2.86, number average molecular weight 72000) 100 parts by mass Methylene chloride (first solvent) 320 parts by mass Methanol (second solvent) 83 parts by mass 1-butanol (third solvent) 3 Parts by mass, triphenyl phosphate 8.3 parts by mass, biphenyl diphenyl phosphate 4.2 parts by mass, compound 1 0.98 parts by mass, compound 2 0.24 parts by mass ──────────── ────────────────────

Specifically, it was prepared by the following method.
After adding the first solvent, the second solvent and the third solvent to a 4000 L stainless steel dissolution tank having a stirring blade and sufficiently stirring, cellulose acetate powder (flake), triphenyl phosphate, biphenyl diphenyl phosphate Compound 1 and Compound 2 were gradually added to prepare a total of 2000 kg.
A dissolver type eccentric stirring shaft that initially stirs the dissolution tank at a peripheral speed of 5 m / sec, and an anchor blade on the central axis, and a peripheral speed of 1 m / sec (shear stress: 1 × 10 ⁴ It was dispersed for 30 minutes under the condition of stirring at kgf / m / sec ² ). After the dispersion was completed, the high-speed stirring was stopped, and the peripheral speed of the anchor blade was set to 0.5 m / sec, and stirring was further performed for 100 minutes.

The solution in which the cellulose acetate powder was swollen was sent from the dissolution tank to the jacketed pipe by a pump. Subsequently, it heated to 50 degreeC with piping with a jacket, and also heated to 90 degreeC by pressurization of 2 Mpa, and melt | dissolved completely. The heating time was 15 minutes.
Next, the temperature was lowered to 36 ° C., and a dope was obtained by passing through a filter medium having a nominal pore diameter of 8 μm.

  The pre-concentration dope thus obtained was flashed in a flash apparatus adjusted to normal pressure at 80 ° C., and the evaporated solvent was recovered and separated by a condenser. The solid concentration of the dope after flashing was 21.8% by mass. The flash tank of the flash device was defoamed by stirring at a peripheral speed of 0.5 m / sec using an anchor blade on the central axis. The temperature of the dope in the tank was 25 ° C., and the average residence time in the tank was 50 minutes.

  Next, bubbles were removed by irradiating the dope with weak ultrasonic waves. Thereafter, under a pressure of 1.5 MPa, first, a sintered fiber metal filter having a nominal pore diameter of 10 μm was passed, and then, a 10 μm sintered fiber filter was also passed. The dope temperature after filtration was adjusted to 36 ° C. and stored in a 2000 L stainless steel stock tank. Using a stock tank having an anchor blade on the central axis, and constantly stirring at a peripheral speed of 0.3 m / sec, a core layer dope 1 was obtained.

(2) Preparation of dope 1-a for support layer Matting agent (silicon dioxide (particle size 20 nm)) and peeling accelerator (citric acid ethyl ester (citric acid, monoethyl ester, diethyl ester, triethyl ester mixture)) The core layer dope 1 was mixed through a static mixer to prepare a support layer dope 1-a. The amount added was such that the total solid content concentration was 20.5% by mass, the matting agent concentration was 0.05% by mass, and the release accelerator concentration was 0.03% by mass.

(3) Preparation of Air Layer Dope 1-b A matting agent (silicon dioxide (particle size: 20 nm)) is mixed with the core layer dope 1 through a static mixer to obtain an air layer dope 1-b. Prepared. The amount added was such that the total solid content concentration was 20.5% by mass and the matting agent concentration was 0.1% by mass.

(4) Film formation by co-casting Equipped with a feed block adjusted for co-casting as a casting die, an apparatus that can form a three-layer film by laminating on both sides in addition to the main stream Was used. In the following description, a layer formed from the mainstream is referred to as a core layer, a support surface side layer is referred to as a support layer, and an opposite surface is referred to as an air layer. As the dope liquid supply flow path, three flow paths for the core layer, the support layer, and the air layer were used.

The core layer dope, support layer dope 1-a, and air layer dope 1-b were co-cast from a casting port onto a drum cooled to -5 ° C. At this time, the flow rate of each dope was adjusted so that the thickness ratio was air layer / core layer / support layer = 3/54/3. The cast dope film was dried by applying a drying air of 34 ° C. at 230 m ³ / min on the drum, and the residual solvent was peeled off from the drum in a state of 150%. During peeling, 17% stretching was performed in the transport direction (longitudinal direction). Thereafter, the film was conveyed while gripping both ends of the film in the width direction (direction perpendicular to the casting direction) with a pin tenter (a pin tenter described in FIG. 3 of JP-A-4-1009). Furthermore, it dried further by conveying between the rolls of a heat processing apparatus, and obtained the TAC film (TAC1) with a film thickness of about 60 μm. Table 1 below shows Re, Rth, and Re / Rth of the obtained TAC1.

[Examples 1 to 13 and Comparative Examples 1 to 5]
[Production of optical film]
<Preparation of optically anisotropic layer>
On each of the prepared supports (see Table 1 below), an alignment film forming coating solution 1 having the following composition was applied with a # 14 wire bar. After drying at 25 ° C. for 30 seconds, the substrate was further put in an oven at 125 ° C. and dried for 100 seconds to form the support 1 with alignment film. The thickness of the alignment film was 0.49 μm.
─────────────────────────────────
Composition of coating liquid 1 for alignment film formation ──────────────────────────────────
Polymer material for alignment film (P-1) 2.50 parts by mass photoacid generator (S-1) 0.20 parts by mass radical polymerization initiator (Irgacure 2959, manufactured by Ciba Specialty Chemicals)
0.18 parts by mass Methanol 26.50 parts by mass IPA (isopropanol) 10.31 parts by mass pure water 60.31 parts by mass ─────────────────────── ──────────

(UV exposure)
The alignment film was rubbed once in one direction at 900 rpm while maintaining a 45 ° angle with respect to the stripe of the stripe mask.
Next, a stripe mask having a lateral stripe width of 363 μm in the transmissive part and a lateral stripe width of 363 μm in the shielding part is placed on the prepared support 1 with an alignment film before exposure, and a wavelength region of 200 nm to 400 nm under room temperature air. A pattern alignment film is formed by irradiating ultraviolet rays for 0.06 seconds (30 mJ / cm ² ) using a UV light irradiation device (Light Hammer 10, 240 W / cm, manufactured by Fusion UV Systems) with a illuminance of 500 mW / cm ^{2 as} a light source unit. did.

(Formation of patterned optically anisotropic layer 1 (formulation 1)-Examples 1 to 8 and 13 and Comparative Examples 1 to 4)
Next, the following coating solution 1 for optically anisotropic layer was applied with a wire bar of # 3.2. Furthermore, after heating and aging at a film surface temperature of 115 ° C. for 1 minute, it was cooled to 90 ° C. and irradiated with ultraviolet rays for 20 seconds using an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) of 20 mW / cm ² under air. The patterned optical anisotropic layer 1 was formed by fixing the orientation state. In the mask exposure portion (first retardation region), the discotic liquid crystal compound is vertically aligned with the slow axis direction parallel to the rubbing direction, and the unexposed portion (second retardation region) is vertically aligned perpendicularly. It was. The film thickness of the optically anisotropic layer 1 was 1.16 μm.

─────────────────────────────────
Composition of coating solution 1 for optically anisotropic layer ──────────────────────────────────
Discotic liquid crystal E-2 80 parts by mass Discotic liquid crystal E-3 20 parts by mass alignment film interface alignment agent (II-1) 0.9 parts by mass alignment film interface alignment agent (III-1) 0.08 parts by mass air interface Alignment agent (P-2) 0.2 parts by mass Air interface alignment agent (P-3) 0.6 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by BASF) 3.0 parts by mass Other functional monomer (ethylene oxide modification) Trimethylolpropane triacrylate (Biscoat 360, manufactured by Osaka Organic Chemical Co., Ltd.))
10 parts by mass Methyl ethyl ketone 268 parts by mass──────────────────────────────────

(Formation of patterned optically anisotropic layer 2 (formulation 2)-Examples 9 to 12 and Comparative Example 5)
The optically anisotropic layer 2 was formed in the same manner as in the prescription 1, except that the following optically anisotropic layer coating solution 2 was used instead of the optically anisotropic layer coating solution 1. In addition, the composition similar to the coating liquid 1 for optically anisotropic layers was used except the discotic liquid crystal E-4 in the composition of the following optically anisotropic layer coating liquid 2.

─────────────────────────────────
Composition of coating solution 2 for optically anisotropic layer ──────────────────────────────────
Discotic liquid crystal E-4 80 parts by mass Discotic liquid crystal E-3 20 parts by mass alignment film interface alignment agent (II-1) 0.9 parts by mass alignment film interface alignment agent (III-1) 0.09 parts by mass air interface Alignment agent (P-2) 0.2 parts by mass Air interface alignment agent (P-3) 0.6 parts by mass Photopolymerization initiator (Irgacure 907, manufactured by BASF) 3.0 parts by mass Other functional monomer (ethylene oxide modification) Trimethylolpropane triacrylate (Biscoat 360, manufactured by Osaka Organic Chemical Co., Ltd.))
10 parts by mass Methyl ethyl ketone 268 parts by mass──────────────────────────────────

<Preparation of hard coat layer>
For Examples 2, 4, 5 and 7 to 13 and Comparative Examples 2, 4 and 5, antiglare hard coat layers shown below were prepared.

(Formation of antiglare hard coat layer 1 (antiglare layer 1)-Examples 2 and 7 to 12 and Comparative Example 5)
Each component was mixed with a mixed solvent (89 to 11 (mass ratio)) of MIBK (methyl isobutyl ketone) and MEK (methyl ethyl ketone) so as to have the following composition. Filtration through a polypropylene filter having a pore diameter of 30 μm prepared antiglare hard coat layer coating solution 1. The solid concentration of each coating solution is 40% by mass. In preparing the coating solution, the resin particles and smectite were added in the state of a dispersion described later.
─────────────────────────────────
Anti-glare hard coat layer coating solution 1
─────────────────────────────────
Smectite (Lucentite STN, manufactured by Corp Chemical)
1.00% by mass
Resin particles (Techpolymer SSX, manufactured by Sekisui Plastics Co., Ltd.) 8.00% by mass
Acrylate monomer (NK ester A9550, manufactured by Shin-Nakamura Chemical Co., Ltd.)
87.79% by mass
Polymerization initiator (Irgacure 907, manufactured by BASF) 3.00% by mass
Leveling agent (P-4) 0.15% by mass
Dispersant (DISPERBYK-2164, manufactured by Big Chemie Japan)
0.06 mass%
─────────────────────────────────

(Preparation of resin particle dispersion)
The dispersion of translucent resin particles is gradually added to the stirred MIBK solution until translucent resin particles (Techpolymer SSX, manufactured by Sekisui Kasei Co., Ltd.) reach a solid content concentration of 30% by mass. For 30 minutes.

(Preparation of smectite dispersion)
The smectite dispersion was finally added to all MEKs used in the antiglare hard coat layer coating solution 1, and smectite (Lucentite STN, manufactured by Corp Chemical Co.) was gradually added while stirring in the MEK. Prepared by stirring for 30 minutes.

(Coating of anti-glare layer 1)
The support on which the optically anisotropic layer was formed was unwound in the form of a roll, and the antiglare hard coat layer coating solution 1 was used to coat the antiglare layer so as to have a film thickness of 4 μm.
Specifically, each coating solution was applied under the condition of a conveyance speed of 30 m / min by a die coating method using a slot die described in Example 1 of JP-A-2006-122889, and dried at 80 ° C. for 150 seconds. Further, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) having an oxygen concentration of about 0.1% under a nitrogen purge, it is applied by irradiating ultraviolet rays with an illuminance of 400 mW / cm ² and an irradiation amount of 180 mJ / cm ^2. The layer was cured to form an antiglare hard coat layer 1 (antiglare layer 1).

(Formation of antiglare hard coat layer 2 (antiglare layer 2)-Examples 4 and 13 and Comparative Examples 2 and 4)
Instead of the antiglare hard coat layer coating solution 1, except for using the antiglare hard coat layer coating solution 2 having the following composition, by the same method as the antiglare hard coat layer 1 (antiglare layer 1), Antiglare hard coat layer 2 (antiglare layer 2) was formed.

─────────────────────────────────
Antiglare hard coat layer coating solution 2
─────────────────────────────────
Smectite (Lucentite STN, manufactured by Corp Chemical)
1.00% by mass
Resin particles (Techpolymer SSX, manufactured by Sekisui Plastics Co., Ltd.) 8.00% by mass
Acrylate monomer (NK ester A9550, manufactured by Shin-Nakamura Chemical Co., Ltd.)
87.79% by mass
Polymerization initiator (Irgacure 907, manufactured by BASF) 3.00% by mass
UV absorber (Tinubin 1557, manufactured by BASF) 5.00% by mass
Leveling agent (P-4) 0.15% by mass
Dispersant (DISPERBYK-2164, manufactured by Big Chemie Japan)
0.06 mass%
─────────────────────────────────

(Formation of antiglare hard coat layer 3 (antiglare layer 3)-Example 5)
In place of the antiglare hard coat layer coating solution 1, except for using the antiglare hard coat layer coating solution 3 having the following composition, the same method as the antiglare hard coat layer 1 (antiglare layer 1) is used. An antiglare hard coat layer 3 (antiglare layer 3) was formed.

─────────────────────────────────
Antiglare hard coat layer coating solution 3
─────────────────────────────────
Smectite (Lucentite STN, manufactured by Corp Chemical)
1.00% by mass
Resin particles (Techpolymer SSX, manufactured by Sekisui Plastics Co., Ltd.) 8.00% by mass
Acrylate monomer (NK ester A9550, manufactured by Shin-Nakamura Chemical Co., Ltd.)
87.79% by mass
Polymerization initiator (Irgacure 907, manufactured by BASF) 3.00% by mass
Ultraviolet absorber (RUVA-93, manufactured by Otsuka Chemical Co., Ltd.) 5.00% by mass
Leveling agent (P-4) 0.15% by mass
Dispersant (DISPERBYK-2164, manufactured by Big Chemie Japan)
0.06 mass%
─────────────────────────────────

[Preparation of polarizing plate]
1) Saponification of film A commercially available cellulose acylate film (Fujitack ZRD40, manufactured by Fuji Film Co., Ltd.), a commercially available cellulose acylate film (Fujitac TD60, manufactured by Fuji Film Co., Ltd.) and each optical film prepared above were used. After immersing in a 1.5 mol / L NaOH aqueous solution (saponification solution) maintained at 55 ° C. for 2 minutes, the film was washed with water, and then immersed in a 0.05 mol / L sulfuric acid aqueous solution at 25 ° C. for 30 seconds. A water bath was passed under running water for 30 seconds to make the film neutral. Then, draining with an air knife was repeated three times, and after dropping the water, the film was retained in a drying zone at 70 ° C. for 15 seconds and dried to produce a saponified film.
2) Production of Polarizer According to Example 1 of Japanese Patent Application Laid-Open No. 2001-141926, iodine was adsorbed to a stretched polyvinyl alcohol film to produce a polarizer having a thickness of 20 μm.
3) Bonding (preparation of front side polarizing plate)
The cellulose acylate film ZRD40 after saponification, the polarizer prepared above, and the optical film after saponification were bonded in this order with a PVA adhesive and thermally dried to prepare a front side polarizing plate. At this time, the saponified surface of the cellulose acylate film and the saponified support side of the optical film were set to the polarizer side.
Under the present circumstances, it arrange | positioned so that the longitudinal direction of the produced polarizer roll and the longitudinal direction of an optical film may become parallel. Moreover, it arrange | positioned so that the longitudinal direction of the roll of a polarizer and the longitudinal direction of the roll of the said cellulose acylate film ZRD40 may become parallel.
(Preparation of rear-side polarizing plate)
The cellulose acylate film TD60 after saponification, the stretched iodine-based PVA polarizer, and the cellulose acylate film ZRD40 after saponification were bonded together in this order with a PVA-based adhesive and thermally dried to obtain a rear-side polarizing plate. .
Under the present circumstances, it arrange | positioned so that the longitudinal direction of the roll of the produced polarizer and the longitudinal direction of the cellulose acylate film TD60 may become parallel. Moreover, it arrange | positioned so that the longitudinal direction of the roll of a polarizer and the longitudinal direction of the roll of the said cellulose acylate film ZRD40 may become parallel.

<Rainbow rainbow>
The produced polarizing plate is a polyester film on the outgoing light side of a liquid crystal display device using a white LED composed of a light emitting element combining a blue light emitting diode and a yttrium / aluminum / garnet yellow phosphor as a light source (Nichia Chemical, NSPW500CS). Was installed on the viewer side.
This liquid crystal display device has a polarizing plate having two TAC films as polarizer protective films on the incident light side of the liquid crystal cell. Visual observation was performed from the front and oblique directions of the polarizing plate of the liquid crystal display device, and the presence or absence of rainbow spots was evaluated according to the following criteria. The results are shown in Table 1 below.
A: No rainbow spots from any direction.
B: When observed from an oblique direction, a partly extremely thin rainbow can be observed.
C: Iris can be clearly observed when observed from an oblique direction.

<Orientation defect>
A first polarizing plate was installed between the light source of the optical microscope and the sample table, and a λ / 4 plate was installed between the sample table and the eyepiece. Next, a second polarizing plate was placed between the λ / 4 plate and the eyepiece.
Next, each optical film produced above is placed on the sample stage so that the optical anisotropic layer is on the eyepiece side, and the optical axis of the first polarizing plate and the optical axis of PET of the optical film are parallel to each other. Samples were installed so that Further, the λ / 4 plate is rotated so that the optical axis of the λ / 4 plate is 45 ° with the optical axis of the first polarizing plate, and the optical axis of the second polarizing plate is the optical axis of the first polarizing plate. And the second polarizing plate was rotated so as to form 90 °. In this way, one region of the optically anisotropic layer was quenched, and the size and number of bright spots in the quenched region were measured.
Next, the λ / 4 plate was rotated 90 ° and fixed at a position where the other region was quenched. The sample was observed from the eyepiece lens, and the size and number of bright spots in the quenched region were measured.
From the size and number of bright spots in both regions, alignment defects were evaluated according to the following criteria. The results are shown in Table 1 below.
A: 20 or less bright spots with a size of several μm are observed.
B: More than 20 bright spots with a size of several μm are observed.
C: Bright spots with a size of several tens of μm are observed, or more than 100 bright spots are observed.

From the results shown in Table 1, it was found that the optical films of Comparative Examples 3 and 4 using an acetylcellulose-based resin as a support could suppress the occurrence of rainbow unevenness but were inferior to alignment defects. Even when PET is used for the support, the optical films of Comparative Examples 1 and 2 in which the Re value is outside the predetermined range, or Comparative Example 5 in which the Re / Rth value is outside the predetermined range In the optical film, the occurrence of orientation defects could be suppressed, but it was found that rainbow unevenness occurred.
On the other hand, it was found that the optical films of Examples 1 to 13 using PET having Re and Re / Rth values in the predetermined ranges as the support can suppress the occurrence of alignment defects and rainbow unevenness.
In particular, from the comparison between Example 1 and Example 6 and the comparison between Example 2 and Example 7, the use of PET1 that does not contain an ultraviolet absorber further suppresses the occurrence of alignment defects and rainbow unevenness. I understood that I could do it. Similarly, from the comparison between Example 10 and Example 11, it was found that the use of PET 9 not containing an ultraviolet absorber can suppress alignment defects more. In addition, Example 8 using PET6 and Example 12 using PET11 contain an ultraviolet absorber, but the surface of the support (PET) on the side where the optically anisotropic layer is provided is exposed to ultraviolet rays. Since no absorbent was contained, it was found that the occurrence of alignment defects and rainbow unevenness can be further suppressed as in Example 10.

  Even when a polyethylene terephthalate resin having a high birefringence is used as a support, the present invention not only suppresses the occurrence of alignment defects and rainbow unevenness, but also provides desired optical properties for the patterned optical anisotropic layer. Since it becomes possible to express the characteristics and the high durability of the polyethylene terephthalate resin can be utilized, it is very useful.

DESCRIPTION OF SYMBOLS 10 Optical film 12 Support body 14 Pattern optical anisotropic layer 14a 1st phase difference area a In-plane slow axis of 1st phase difference area 14b 2nd phase difference area b In-plane slow axis of 2nd phase difference area 16 Hard coat layer 18 UV absorbing layer 20 Polarizing plate 22 Polarizer (viewing side)
24 Polarizer Protective Film 30 Liquid Crystal Display Device 32 Liquid Crystal Cell 34 Polarizer (Backlight Side)
36, 38 Polarizer protective film

Claims (5)

A polarizing plate having an optically anisotropic layer, a support, and a polarizer in this order, and an image display device comprising a light source,
The laminate having the optically anisotropic layer and the support is composed of an optical film having the support and an optically anisotropic layer provided on the support,
The optically anisotropic layer is a patterned optically anisotropic layer in which regions having two or more different optical characteristics are formed in a pattern,
The support includes a polyethylene terephthalate resin, has an in-plane retardation (Re) of 3000 nm to 30000 nm, and a ratio (Re / Rth) between the in-plane retardation (Re) and the thickness direction retardation (Rth). Is 0.2 to 1.5,
The polarizer, the angle between the optical axis of the support and the optical axis of the polarizer is provided so that such a 0 ° or 90 °,
The image display device, wherein the light source is a white LED composed of a light emitting element in which a blue light emitting diode and a yttrium / aluminum / garnet yellow phosphor are combined.   The image display device according to claim 1, wherein the ratio (Re / Rth) is 0.7 to 1.2. Furthermore, it has a hard coat layer,
The image display device according to claim 1, wherein the hard coat layer is provided on the optically anisotropic layer.   The image display device according to claim 3, wherein the hard coat layer is an antiglare hard coat layer.   5. The image display device according to claim 1, wherein the content of the ultraviolet absorber in the support is 0.1% by mass or less of the mass of the support.