JP2014206725A - Polarizing plate and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate which has the thickness of a polarizer of 10 μm or less, and excellent durability under high temperature environment.SOLUTION: A polarizing plate has at least one or more first polarizing plate protective layer, and a polarizer in this order, the thickness of the polarizer is 10 μm or less, and the moisture vapor permeability of the first polarizing plate protective layer at 40°C and 90% RH is 12 g/m/day or more.

Description

  The present invention relates to a polarizing plate and a liquid crystal display device.

  As the use of liquid crystal display devices is expanded, large-size and high-quality textures are required for liquid crystal display devices. In order to reduce the weight of a large-sized liquid crystal display device, the thickness of various members has been reduced. Among them, the thickness of the glass substrate used for the liquid crystal cell has been 0.7 mm, and recently, the thickness of 0.3 mm has been studied. Even in small and medium-sized applications, thinning is rapidly progressing to reduce weight and secure space for batteries.

  A polarizing plate of a liquid crystal display device generally has a configuration in which a polarizer made of a polyvinyl alcohol film or the like on which iodine or dye is adsorbed and oriented, and a transparent protective film are bonded to both sides of the polarizer. The board is sensitive to changes in temperature and humidity, and tends to expand and contract due to changes in the surrounding environment. As a result of the expansion and contraction of the polarizing plate and the warpage of the liquid crystal cell, display unevenness (light leakage occurring at the four corners of the liquid crystal cell) occurs in the liquid crystal display device. With the recent thinning of glass substrates, display unevenness due to warpage of liquid crystal cells has become apparent.

Therefore, in Patent Document 1, an optical member having a transparent low moisture-permeable layer having a moisture permeability of 100 g / m ² / day or less is disposed closer to the viewer than the polarizer, thereby returning the temperature from a high-temperature and high-humidity environment to room temperature. A method for improving the warpage of the liquid crystal panel at the time is disclosed.

JP 2005-345958 A

  In addition, with recent globalization, liquid crystal display devices are widely used in the world regardless of whether they are large-sized or small-sized, and durability at high temperatures is required in consideration of use in an environment just below the equator. . Furthermore, liquid crystal display devices for small and medium-sized applications are required to have durability at an extremely high temperature close to 100 ° C. due to an increase in the frequency of use in outdoor environments such as mobile phones and tablets, particularly in automotive applications. .

  In order to reduce the thickness of the polarizing plate provided in the liquid crystal display device by the present inventor, the polarizer of the polarizing plate having a low moisture permeability layer was reduced in thickness. It was found that the durability of the polarizer underneath deteriorates.

  The problem to be solved by the present invention is to provide a polarizing plate excellent in durability in a high temperature environment even when the film thickness of the polarizer is thin (for example, 10 μm or less), and a liquid crystal display device using the polarizing plate It is to be.

  When the present inventors diligently studied for the purpose of solving the above problems, in the polarizing plate in which the polarizer is thinned to a thickness of 10 μm or less, the moisture permeability of the protective film of the polarizer is controlled within a specific range. Thus, the inventors have obtained the knowledge that the above problems can be solved, and have further studied based on this finding to complete the present invention.

The above problem has been solved by the following means <1>, preferably <2> to <15>.
<1> It has at least one first polarizing plate protective layer and a polarizer, the thickness of the polarizer is 10 μm or less, and the first polarizing plate protective layer has a temperature of 40 ° C. and a relative humidity of 90%. A polarizing plate having a moisture permeability of 12 g / m ² / day or more.
<2> The polarizing plate according to <1>, further comprising at least one second polarizing plate protective layer on the opposite side of the polarizer from the first polarizing plate protective layer.
<3> The polarizing plate according to <2>, wherein the thickness of the second polarizing plate protective layer is 25 μm or less.
<4> A layer formed by polymerizing an ethylenically unsaturated monomer in at least one of the polarizer and the first polarizing plate protective layer and between the polarizer and the second polarizing plate protective layer, <2> or < The polarizing plate as described in 3>.
<5> The polarizing plate according to <4>, wherein the layer formed by polymerizing the ethylenically unsaturated monomer has a thickness of 5 μm or less.
<6> The first polarizing plate protective layer and / or the second polarizing plate protective layer includes a layer selected from a cellulose acylate polymer layer, a polyester polymer layer, an acrylic polymer layer, and a cycloolefin polymer layer. , <2> to <5>.
<7> The polarizing plate according to any one of <2> to <6>, wherein the first polarizing plate protective layer and / or the second polarizing plate protective layer includes a layer containing a liquid crystalline compound.
<8> The polarizing plate according to any one of <1> to <7>, wherein the polarizing plate has a thickness of 95 μm or less.
<9> The polarizing plate according to any one of <1> to <8>, wherein the thickness of the first polarizing plate protective layer is 60 μm or less.
<10> The polarizing plate according to any one of <1> to <9>, wherein the first polarizing plate protective layer is a layer having ultraviolet absorbing ability.
<11> The polarizing plate according to any one of <1> to <10>, having a hard coat layer on the first polarizing plate protective layer.
<12> A liquid crystal display device comprising a liquid crystal cell and at least one polarizing plate according to any one of <1> to <11>.
<13> The liquid crystal display device according to <12>, wherein the first polarizing plate protective layer is disposed on the side opposite to the liquid crystal cell with respect to the polarizer.
<14> The liquid crystal display device according to <13>, wherein the moisture permeability of the first polarizing plate protective layer at 40 ° C. and 90% relative humidity is 140 g / m ² / day or less and the thickness of the liquid crystal cell is 1100 μm or less. .
<15> The liquid crystal display device according to <13>, wherein the first polarizing plate protective layer has a moisture permeability of 85 g / m ² / day or less at 40 ° C. and 90% relative humidity, and a liquid crystal cell thickness of 700 μm or less. .

  ADVANTAGE OF THE INVENTION According to this invention, even if the film thickness of a polarizer is 10 micrometers or less, the polarizing plate excellent in durability in a high temperature environment and a liquid crystal display device using the same can be provided.

  Hereinafter, the contents of 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, “to” is used to mean that the numerical values described before and after it are included as a lower limit and an upper limit.

  In the present specification, “(meth) acrylate”, “(meth) acrylic acid”, and “(meth) acryloyl” represent “acrylate or methacrylate”, “acrylic acid or methacrylic acid”, and “acryloyl or methacryloyl”, respectively. .

<Polarizing plate>
The polarizing plate of the present invention has at least one first polarizing plate protective layer and a polarizer, the thickness of the polarizer is 10 μm or less, 40 ° C. of the first polarizing plate protective layer, and relative humidity 90%. The moisture permeability at is 12 g / m ² / day or more.
With such a configuration, a polarizing plate having excellent durability under a high temperature environment can be obtained even if the thickness of the polarizer is 10 μm or less. In particular, the effect of the polarizing plate of the present invention is more effectively exhibited when the first polarizing plate protective layer is disposed on the surface opposite to the bonding surface with the liquid crystal cell. The present inventors infer about this principle as follows.
The lower the moisture permeability of the polarizing plate protective layer arranged farther away from the liquid crystal cell in the polarizing plate, the slower the moisture removal from the polarizing plate. As a result, it occurs in the viewing side polarizing plate and the light source side polarizing plate of the liquid crystal display device. It is considered that the difference in the amount of expansion and contraction is reduced, and the warpage generated in the liquid crystal panel is also reduced. Therefore, in the polarizing plate having a polarizer thickness of about 30 μm, it is preferable that the moisture permeability of the polarizing plate protective layer is low. However, it was found that in the polarizing plate in which the polarizer is thinned to 10 μm or less, the durability of the polarizer under a high temperature environment is significantly deteriorated if the moisture permeability of the polarizing plate protective layer is too low. This is presumably because moisture contained in the polarizer and the polarizing plate protective layer itself stays in the polarizing plate under a high temperature environment, although moisture hardly enters from the outside. In a polarizing plate whose polarizer is thinned to 10 μm or less, the durability in a high temperature environment can be improved by setting the moisture permeability of the polarizing plate protective layer at 40 ° C. and 90% RH to 12 g / m ² / day or more. It is considered possible.

  The polarizing plate of the present invention may further include at least one second polarizing plate protective layer on the side of the polarizer opposite to the first polarizing plate protective layer.

  Although there is no restriction | limiting in the whole thickness of the polarizing plate of this invention, from the reason that a liquid crystal display device can be reduced in thickness, 95 micrometers or less are preferable, it is more preferable that it is 80 micrometers or less, and it is 10-60 micrometers. Is more preferable, and it is especially preferable that it is 10-40 micrometers.

[Polarizer]
A conventionally well-known thing can be used as a polarizer used for this invention.
In the present invention, it is preferable to use a commonly used linear polarizer. Linear polarizers are available from Optiva Inc. Are preferable, or a polarizer comprising a binder and iodine or a dichroic dye. The iodine and dichroic dye in the linear polarizer exhibit polarization performance by being oriented in the binder. It is preferable that the iodine and the dichroic dye are aligned along the binder molecule, or the dichroic dye is aligned in one direction by self-assembly such as liquid crystal. Currently, commercially available polarizers are generally made by immersing a stretched polymer in a solution of iodine or dichroic dye in a bath and allowing the iodine or dichroic dye to penetrate into the binder. is there.

  The thickness of the polarizer used in the present invention is 10 μm or less, and is preferably 1 to 8 μm and more preferably 2 to 5 μm because the liquid crystal display device can be thinned.

[First polarizing plate protective layer and second polarizing plate protective layer]
The moisture permeability of the first polarizing plate protective layer used in the present invention at 40 ° C. and a relative humidity of 90% is 12 g / m ² / day or more. Is preferably 12~3500g / m ² · day, more preferably from 12~1200g / m ² · day, more preferably in a ^{12~250g / m 2 · day, 12~140g} / m 2 especially preferably day is, more preferably from 12~100g / m ² · day, and even more preferably 12~85g / m ² · day.

The value of the moisture permeability in the present specification, in accordance with the moisture permeability test of JIS Z0208 (cup method), temperature 40 ° C., 90% relative humidity in the atmosphere, water vapor passing through the sample area 1 m ² in 24 hours It is the value converted into weight (g).

The thickness of the first polarizing plate protective layer used in the present invention is preferably 60 μm or less, more preferably 41 μm or less, and even more preferably 25 μm or less because the liquid crystal display device can be thinned.
Although there is no limitation in particular about a minimum, from a viewpoint of hardness, brittleness, etc., it is usually 1 micrometer or more and it is preferred that it is 5 micrometers or more.

  The thickness of the second polarizing plate protective layer used in the present invention is preferably 25 μm or less, more preferably 20 μm or less, and even more preferably 10 μm or less, because the liquid crystal display device can be thinned. . Although there is no limitation in particular about a minimum, from a viewpoint of hardness, brittleness, etc., it is usually 1 micrometer or more, and it is preferred that it is 5 micrometers or more.

Preferably Knoop hardness of the first polarizing plate protective layer used in the present invention is 235N / mm ² or more, more preferably 240 N / mm ² or more, and particularly preferably 240~290N / mm ² .

The second polarizing plate protective layer used in the present invention preferably satisfies the following formula (1) from the viewpoint of suppressing display unevenness when incorporated in a liquid crystal display device.
Formula (1) | Rth (590) | ≦ 300 nm
(In Formula (1), Rth (590) represents retardation in the film thickness direction at a wavelength of 590 nm.)
| Rth (590) | is preferably 260 nm or less. In particular, when the liquid crystal display device is in the VA mode, | Rth (590) | is more preferably 250 nm or less, and particularly preferably 160 nm or less. When the liquid crystal display device is in the IPS mode, | Rth (590) | is more preferably 50 nm or less, and particularly preferably 10 nm or less, that is, Rth is preferably −10 to 10 nm.

The second polarizing plate protective layer used in the present invention preferably satisfies the following formula (2) from the viewpoint of further improving display unevenness when incorporated in a liquid crystal display device.
Formula (2) | Re (590) | ≦ 100 nm
(In formula (2), Re (590) represents retardation in the in-plane direction of the film at a wavelength of 590 nm.)
| Re (590) | is preferably 80 nm or less. In particular, when the liquid crystal display device is in the VA mode, | Re (590) | is more preferably 75 nm or less. When the liquid crystal display device is in the IPS mode, | Re (590) | is more preferably 10 nm or less, further preferably 5 nm or less, and particularly preferably 2 nm or less.

  In this specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at the wavelength λ, respectively. In the present specification, the wavelength λ is 590 nm unless otherwise specified. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH (manufactured by Oji Scientific Instruments). Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH) as the tilt axis (rotary axis) (in the absence of the slow axis, any direction in the film plane) Is measured in 6 points from the inclined direction in 10 degree steps from the normal direction to 50 degrees on one side with respect to the normal direction of the film. KOBRA 21ADH calculates based on the retardation value, the assumed average refractive index, and the input film thickness value. The retardation value is measured from any two directions with the slow axis as the tilt axis (rotation axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotation axis), and the value Rth can also be calculated from the following formula (A) and formula (B) based on the assumed average refractive index and the input film thickness value. Here, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). The KOBRA 21ADH calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

Here, Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction, nx, ny, and nz represent refractive indexes in respective principal axis directions of the refractive index ellipsoid, and d represents a film. Represents thickness.
Rth = ((nx + ny) / 2−nz) × d Formula (B)
At this time, an average refractive index n is required as a parameter, and a value measured by an Abbe refractometer (“Abbe refractometer 2-T” manufactured by Atago Co., Ltd.) was used.

  The first polarizing plate protective layer used in the present invention preferably has an ultraviolet absorbing ability. Alternatively, it is preferable to separately have a layer having an ultraviolet absorbing ability. In particular, in the liquid crystal display device including the polarizing plate of the present invention, in a mode in which the first polarizing plate protective layer of the polarizing plate is disposed outside the polarizer of the polarizing plate, the liquid crystal display device is disposed farther from the liquid crystal cell than the polarizer. The at least one of the layers including the first polarizing plate protective layer has an ultraviolet absorbing ability, thereby improving the light resistance of the polarizing plate itself, or an image display member such as a polarizing plate or a liquid crystal compound of a liquid crystal display device. It is preferable because deterioration can be prevented.

  In order to add ultraviolet absorbing ability to the first polarizing plate protective layer, it is preferable to add an ultraviolet absorber to the first polarizing plate protective layer. As the ultraviolet absorber, one having an excellent ability to absorb ultraviolet rays having a wavelength of 370 nm or less from the viewpoint of preventing deterioration of the liquid crystal and having as little absorption of visible light having a wavelength of 400 nm or more as possible from the viewpoint of good image display properties is used. It is preferable. In particular, the transmittance at a wavelength of 370 nm is desirably 20% or less, preferably 10% or less, and more preferably 5% or less. Examples of such ultraviolet absorbers include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and ultraviolet absorbing groups as described above. Examples thereof include, but are not limited to, polymer ultraviolet absorbing compounds. Two or more kinds of ultraviolet absorbers may be used.

  The method of adding the ultraviolet absorber when preparing the first polarizing plate protective layer may be added after dissolving in an organic solvent such as alcohol, methylene chloride, dioxolane, or may be added when preparing the pellet. You may add directly in a composition by methods, such as copolymerization. For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and dispersed before addition to the dope.

  The usage-amount of the ultraviolet absorber in the aspect whose said 1st polarizing plate protective layer of this invention is a cellulose acylate is 0.1-5.0 mass parts with respect to 100 mass parts of cellulose acylates, Preferably it is 0.5- It is 2.0 mass parts, More preferably, it is 0.8-2.0 mass parts.

{Materials constituting first polarizing plate protective layer and second polarizing plate protective layer}
There is no restriction | limiting in particular about the material which comprises the 1st polarizing plate protective layer and 2nd polarizing plate protective layer used for this invention. The materials constituting the first polarizing plate protective layer and the second polarizing plate protective layer may each independently be a layer or film made of a polymer (hereinafter sometimes referred to collectively as “film”). , Cellulose acylate polymers, polycarbonate polymers, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, acrylic polymers such as polymethyl methacrylate, styrene polymers such as polystyrene and acrylonitrile / styrene copolymer (AS resin), etc. Can be used. In addition, polyolefins such as polyethylene and polypropylene, polyolefin polymers such as ethylene / propylene copolymers, cycloolefin polymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers, Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinylidene chloride polymer, vinyl alcohol polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or polymer One or two or more kinds of polymers may be selected from the mixed polymers and the like, and a polymer layer or film may be produced using them as the main component. Further, it may be a layer formed by polymerizing a rod-like liquid crystal having a polymerizable group or a discotic liquid crystal in a predetermined alignment state and fixing it.

  The first polarizing plate protective layer and the second polarizing plate protective layer used in the present invention are each independently a cellulose acylate polymer layer, a polyester polymer layer, an acrylic polymer layer, a cycloolefin polymer layer, and a liquid crystal property. It is preferable to include a layer containing a compound. That is, it may be a laminate of two or more polymer layers and a layer comprising the composition. In an embodiment in which the first polarizing plate protective layer includes a cellulose acylate polymer layer, for the purpose of lowering the moisture permeability of the first polarizing plate protective layer, a polyester polymer layer, an acrylic polymer layer, a cycloolefin polymer layer, and It is preferable to further include a layer containing a liquid crystal compound.

<Cellulose acylate polymer layer>
In this specification, the “cellulose acylate polymer layer” refers to a layer and a film containing cellulose acylate as a main component (50% by mass or more of all components). The cellulose acylate used for producing the film is obtained by substituting the hydrogen atom of the hydroxyl group of cellulose with an acyl group. Cellulose acylate is obtained by acylating a hydroxyl group of cellulose, and the substituent can be any acetyl group having 2 carbon atoms in the acyl group to those having 22 carbon atoms.

  The cellulose acylate used in the present invention is not particularly limited. Among them, it is preferable to use cellulose acylate having an acetyl substitution degree of 2.00 to 2.95, more preferably 2.70 to 2.95, and further preferably 2.75 to 2.90. Preferably, it is 2.82 to 2.89. It is preferable for the degree of acetyl substitution to be 2.7 or higher because the compatibility with the aromatic ester oligomer that satisfies the conditions described later is good and the film is not easily whitened. Furthermore, in addition to transparency, moisture permeability and water content are favorable, which is preferable. Moreover, the polarizer durability of the polarizing plate and the wet heat durability of the film itself are also favorable, which is preferable. On the other hand, the degree of substitution is preferably 2.95 or less from the viewpoint of optical performance. The preferred range of the total acyl substitution degree is the same as the preferred range of the acetyl substitution degree. The substitution degree of the acyl group can be measured according to the method specified in ASTM-D817-96. The portion not substituted with an acyl group usually exists as a hydroxyl group.

Among the acyl groups having 2 to 22 carbon atoms to be substituted for the hydroxyl group of cellulose, the acyl group having 2 to 22 carbon atoms may be an aliphatic group or an allyl group, and is not particularly limited. A single or a mixture of two or more types But you can. They are, for example, alkyl carbonyl esters, alkenyl carbonyl esters, aromatic carbonyl esters, aromatic alkyl carbonyl esters, etc. of cellulose, each of which may further have a substituted group. These preferred acyl groups include acetyl, propionyl, butanoyl, heptanoyl, hexanoyl, octanoyl, decanoyl, dodecanoyl, tridecanoyl, tetradecanoyl, hexadecanoyl, octadecanoyl, iso-butanoyl, t-butanoyl, cyclohexanecarbonyl, Examples include oleoyl, benzoyl, naphthylcarbonyl, and cinnamoyl groups. Among these, acetyl, propionyl, butanoyl, dodecanoyl, octadecanoyl, t-butanoyl, oleoyl, benzoyl, naphthylcarbonyl, cinnamoyl and the like are preferable, and acetyl, propionyl and butanoyl are more preferable.
In the cellulose acylate used in the present invention, the substituent is preferably an acetyl group or a propionyl group, and more preferably an acetyl group.

  In addition, mixed fatty acid cellulose acylate may be used. Specific examples of the mixed fatty acid cellulose acylate include cellulose acetate propionate and cellulose acetate butyrate, and cellulose acetate propionate is preferable.

  The basic principle of the cellulose acylate synthesis method is described in Mita et al., Wood Chemistry pages 180-190 (Kyoritsu Shuppan, 1968). A typical synthesis method is a liquid phase acetylation method using a carboxylic acid anhydride-acetic acid-sulfuric acid catalyst.

The molecular weight of the cellulose acylate polymer layer is preferably from 40,000 to 200,000, more preferably from 100,000 to 200,000 in terms of number average molecular weight (Mn). The cellulose acylate used in the present invention preferably has an Mw / Mn ratio of 4.0 or less, more preferably 1.4 to 2.3.
In the present invention, the average molecular weight and molecular weight distribution of cellulose acylate and the like are calculated by calculating the number average molecular weight (Mn) and the weight average molecular weight (Mw) using gel permeation chromatography (GPC). International Publication WO 2008-126535 The ratio can be calculated by the method described in the publication.

The cellulose acylate polymer layer may contain an additive together with cellulose acylate as a main component, and for example, preferably contains at least one aromatic ester oligomer. It is preferable to add the aromatic ester oligomer in a low addition amount because the Knoop hardness of the cellulose acylate polymer layer can be increased. For example, the Knoop hardness of the cellulose acylate film can be increased by subjecting the cellulose acylate film containing the aromatic ester oligomer to a stretching treatment (preferably a biaxial stretching treatment).
Here, as a method for representing the hardness of a film in which a hard coat layer is provided on a cellulose acylate polymer layer, a method represented by the Knoop hardness of the film in addition to the pencil hardness of the hard coat layer is known. Knoop hardness is one of the scales representing the hardness of a material, and is a kind of indentation hardness.

  Further, in a preferred embodiment of the polarizing plate of the present invention, the addition of an additive improves the deterioration in polarization performance during thermo treatment due to an increase in moisture permeability due to thinning of the cellulose acylate polymer layer, and polarization The child durability can also be improved.

  Hereinafter, the additive preferably used for the cellulose acylate polymer layer will be described.

《Aromatic ester oligomer》
In the cellulose acylate polymer layer used in the present invention, an aromatic ester oligomer may be used for the purpose of increasing the Knoop hardness.
The aromatic ester oligomer is not particularly limited. Among them, having a repeating unit derived from a dicarboxylic acid and a repeating unit derived from a diol, among the repeating units derived from a dicarboxylic acid, the molar ratio of the repeating unit derived from an aliphatic dicarboxylic acid is m, and the repeating unit derived from an aromatic dicarboxylic acid When the molar ratio is n, m: n is preferably 0:10 to 3: 7. When ester oligomers penetrate into the free volume part of cellulose, it is estimated that increasing the phthalic acid ratio increases the hardness derived from the material and increases the Knoop hardness of the film.
Without being bound by any theory, the Knoop hardness of the cellulose acylate polymer layer can be increased by using an aromatic ester oligomer, and the molar ratio of the repeating units derived from the aliphatic dicarboxylic acid of the aromatic ester oligomer. M, the Knoop hardness of the cellulose acylate polymer layer can be further increased by controlling the ratio of the molar ratio n of the repeating units derived from the aromatic dicarboxylic acid.
The reason why “the pencil hardness is different despite the same Knoop hardness” between thin films is thought to be because the penetration of the hard coat layer into the cellulose acylate polymer layer varies depending on the properties of the plasticizer. It is thought that pencil hardness becomes so low that it is easy to saturate into a cellulose acylate type polymer layer.
By using an aromatic ester oligomer, the molar ratio of the repeating unit derived from the aliphatic dicarboxylic acid of the aromatic ester oligomer is m, and the ratio of the molar ratio n of the repeating unit derived from the aromatic dicarboxylic acid is controlled. While increasing Knoop hardness, it is possible to suppress the penetration of the hard coat layer into the cellulose acylate polymer layer, and to increase the pencil hardness when the hard coat layer is provided.
In addition, by using an aromatic ester oligomer, an optical film having no display unevenness when incorporated in a liquid crystal display device as an optical film disposed inside a polarizer can be provided.

The number average molecular weight (Mn) of the aromatic ester oligomer used in the present invention is preferably 600 to 2000, more preferably 600 to 1500, and still more preferably 600 to 1200. If the number average molecular weight of the aromatic ester oligomer is 600 or more, the volatility is low, and film failure and process contamination due to volatilization under high temperature conditions during stretching of the cellulose acylate polymer layer are less likely to occur. Moreover, if it is 2000 or less, compatibility with a cellulose acylate will become high and it will become difficult to produce the bleed-out at the time of film forming and a heat-stretching.
The number average molecular weight of the aromatic ester oligomer in the present invention can be measured and evaluated by gel permeation chromatography.

  The aromatic ester oligomer used in the present invention is preferably synthesized from a diol having 2 to 10 carbon atoms and a dicarboxylic acid having 4 to 10 carbon atoms. As the synthesis method, a known method such as a dehydration condensation reaction of a dicarboxylic acid and a diol, or addition of a dicarboxylic anhydride to glycol and a dehydration condensation reaction can be used.

Here, the aromatic ester oligomer is preferably a polyester oligomer obtained by synthesis of an aromatic dicarboxylic acid, which is a dicarboxylic acid, and a diol.
The dicarboxylic acid and diol that can be preferably used for the synthesis of the aromatic ester oligomer used in the present invention will be described below.

-Dicarboxylic acid-
As the dicarboxylic acid, either an aliphatic dicarboxylic acid or an aromatic dicarboxylic acid can be used.
Examples of the aromatic dicarboxylic acid include phthalic acid, terephthalic acid, and isophthalic acid. Among these, phthalic acid and terephthalic acid are preferable, from the viewpoint of improving pencil hardness when a hard coat layer is provided, improving display unevenness when incorporated in a liquid crystal display device, and improving polarizer durability. Phthalic acid is particularly preferred. Two or more aromatic dicarboxylic acids may be used in combination. Specifically, combined use of phthalic acid and terephthalic acid can be mentioned. Among aromatic ester oligomers, it is possible to improve the pencil hardness when a hard coat layer is provided, to improve display unevenness when incorporated in a liquid crystal display device, and to improve the durability of a polarizer. Among them, it is preferable to increase the ratio of phthalic acid. Among the repeating units derived from dicarboxylic acid contained in the aromatic ester oligomer, the ratio of the repeating units derived from phthalic acid is preferably 70 mol% or more, and 80 mol% or more. More preferably, it is 90 mol% or more. The ratio (molar ratio) of phthalic acid to terephthalic acid is preferably 5: 5 to 10: 0, from 7: 3 to 10: 0, from the viewpoint of reducing Rth of the cellulose acylate polymer layer. More preferably, it is particularly preferably 10: 0.
Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, suberic acid, azelaic acid, cyclohexanedicarboxylic acid, and sebacic acid. Of these, succinic acid and adipic acid are preferable, and adipic acid is particularly preferable.
The carbon number of the dicarboxylic acid used in the present invention is preferably 4-10, and more preferably 4-8. In the present invention, a mixture of two or more kinds of dicarboxylic acids may be used. In this case, the average carbon number of the two or more kinds of dicarboxylic acids is preferably within the above range. If the carbon number of the dicarboxylic acid is within the above range, it is preferable because it is excellent in compatibility with cellulose acylate and bleed-out hardly occurs even when the cellulose acylate polymer layer is formed and heated.
An aliphatic dicarboxylic acid and an aromatic dicarboxylic acid may be used in combination. Specific examples include a combination of adipic acid and phthalic acid, a combination of adipic acid and terephthalic acid, a combination of succinic acid and phthalic acid, and a combination of succinic acid and terephthalic acid.
When the aliphatic dicarboxylic acid and the aromatic dicarboxylic acid are used in combination, the ratio (molar ratio) between them is m for the repeating unit derived from the aliphatic dicarboxylic acid, and n for the repeating unit derived from the aromatic dicarboxylic acid. M: n is 0:10 to 3: 7, more preferably 0:10 to 2: 8.

-Diol-
Examples of the diol include aliphatic diols and aromatic diols, with aliphatic diols being preferred.
Examples of the aliphatic diol include alkyl diols and alicyclic diols, such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3- Butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2- Diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl-1, 5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 2, , 4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, etc. Is mentioned.
Preferred aliphatic diols are at least one of ethylene glycol, 1,2-propanediol, and 1,3-propanediol, and particularly preferably at least one of ethylene glycol and 1,2-propanediol. Of these, ethylene glycol is particularly preferred from the viewpoint of compatibility with cellulose. When two types are used, it is preferable to use ethylene glycol and 1,2-propanediol.
The number of carbon atoms of the glycol is preferably 2 to 10, more preferably 2 to 6, and particularly preferably 2 to 4. When using 2 or more types of glycols, it is preferable that the average number of carbons of 2 or more types falls in the above range. If the carbon number of the glycol is in the above range, it is preferable because the compatibility with the cellulose acylate is excellent and bleed-out hardly occurs even when the cellulose acylate polymer layer is formed and heated.

-Sealing-
Although both ends of the aromatic ester oligomer used in the present invention may be sealed or unsealed, it is preferable that the aromatic ester oligomer is particularly sealed at the end with an alkyl group or an aromatic group. This is due to the fact that protecting the terminal with a hydrophobic functional group is effective in improving the polarizer durability of the polarizing plate and shows a role of delaying hydrolysis of the ester group.
It is preferable to protect with a monoalcohol residue or a monocarboxylic acid residue so that both ends of the aromatic ester oligomer do not become carboxylic acid or OH group. The hydroxyl value of the aromatic ester oligomer is preferably 10 mgKOH / g or less from the viewpoint of improving polarizer durability, more preferably 5 mgKOH / g or less, and particularly preferably 0 mgKOH / g.
When both ends of the aromatic ester oligomer are sealed, it is preferable to seal by reacting with a monocarboxylic acid. At this time, both ends of the aromatic ester oligomer are monocarboxylic acid residues. Here, the residue is a partial structure of an aromatic ester oligomer and represents a partial structure having the characteristics of a monomer forming the aromatic ester oligomer. For example, the monocarboxylic acid residue formed from monocarboxylic acid R—COOH is R—CO—. An aliphatic monocarboxylic acid residue is preferred, the monocarboxylic acid residue is more preferably an aliphatic monocarboxylic acid residue having 2 to 22 carbon atoms, and an aliphatic monocarboxylic acid residue having 2 to 3 carbon atoms is more preferred. It is more preferably a group, and particularly preferably an aliphatic monocarboxylic acid residue having 2 carbon atoms.
If the number of carbon atoms of the monocarboxylic acid residues at both ends of the aromatic ester oligomer is 3 or less, the volatility will be reduced, the weight loss due to heating of the aromatic ester oligomer will not be large, and process contamination and surface faults will occur. Can be reduced. That is, as the monocarboxylic acids used for sealing, aliphatic monocarboxylic acids are preferable to aromatic carboxylic acids from the viewpoint of production suitability and surface quality. More preferably, the monocarboxylic acid is an aliphatic monocarboxylic acid having 2 to 22 carbon atoms, more preferably an aliphatic monocarboxylic acid having 2 to 3 carbon atoms, and an aliphatic monocarboxylic acid residue having 2 carbon atoms. Particularly preferred is a group. For example, acetic acid, propionic acid, butanoic acid and derivatives thereof are preferable, acetic acid or propionic acid is more preferable, and acetic acid (terminal is an acetyl group) is most preferable. Two or more monocarboxylic acids used for sealing may be mixed.
When both ends are sealed, a cellulose acylate polymer layer excellent in handling at a normal temperature is not likely to be in a solid state, and is excellent in humidity stability and polarizer durability of a polarizing plate.

-Synthesis method-
The synthesis of the aromatic ester oligomer is carried out by a polyesterification reaction or a transesterification reaction between a dicarboxylic acid containing an aromatic dicarboxylic acid, a diol, and a monocarboxylic acid or monoalcohol for end-capping as required. It can be easily synthesized by either the hot melt condensation method or the interfacial condensation method of these acid chlorides and glycols.

-Addition amount-
In the cellulose acylate polymer layer used in the present invention, the content of the aromatic ester oligomer is preferably 5% by mass to 25% by mass and more preferably 5% by mass to 20% by mass with respect to the cellulose acylate. More preferably, the content is 5 to 15% by mass.

<< Compound Represented by Formula (1) or (2) >>
From the viewpoint of improving polarizer durability, the cellulose acylate polymer layer used in the present invention has a molecular weight / aromatic number ratio of 300 or less, and a general formula (1) or (2) described later. You may use the compound represented. These compounds are also preferably used from the viewpoint of realizing a pencil hardness of 3H when a hard coat layer is provided. In the following, the compound represented by the general formula (1) or (2) may be referred to as a polarizer durability improver.
The polarizer durability improving agent preferably has a hydrogen bonding hydrogen donating group.

Examples of hydrogen bonding hydrogen donating groups are described, for example, in Jeffrey, George A., et al. It is described in a book such as Introduction to Hydrogen Bonding published by Oxford UP.
In the present invention, the hydrogen bondable hydrogen donating group in the polarizer durability improving agent includes amino group, acylamino group, alkoxycarbonylamino group, aryloxycarbonyl from the viewpoint of interaction with carbonyl group in cellulose acylate. An amino group, a sulfonylamino group, a hydroxy group, a mercapto group, and a carboxyl group are preferable, a sulfonylamino group, an acylamino group, an amino group, and a hydroxyl group are more preferable, and an amino group and a hydroxyl group are still more preferable.

The ratio of molecular weight / aromatic ring number in the polarizer durability improver is 300 or less, preferably 190 or less, more preferably 160 or less, and particularly preferably 150 or less.
The ratio of molecular weight / aromatic ring number in the polarizer durability improving agent is preferably 90 or more, and more preferably 100 or more, from the viewpoint of improving compatibility with cellulose acylate.

The molecular weight of the polarizer durability improving agent is preferably 200 to 1000, more preferably 250 to 800, and particularly preferably 280 to 600. When the molecular weight is equal to or higher than the lower limit of the above range, disappearance due to volatilization of the polarizer durability improver during film formation of the cellulose acylate polymer layer can be suppressed, and when the molecular weight is equal to or lower than the upper limit of the above range. A cellulose acylate polymer layer having good compatibility between the acylate and the polarizer durability improving agent and having a low haze is preferable.
Hereinafter, the polarizer durability improving agent will be described in the order of the compound represented by the general formula (1) and the compound represented by the general formula (2).

-Compound represented by the general formula (1)-

In General Formula (1), R ¹ represents a substituent, R ² represents a substituent represented by the following General Formula (1-2); n1 represents an integer of 0 to 4, and n1 is 2 or more. A plurality of R ¹ may be the same or different from each other; n2 represents an integer of 1 to 5, and when n2 is 2 or more, a plurality of R ² may be the same or different from each other. Also good.

In general formula (1-2), A represents a substituted or unsubstituted aromatic ring; R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the following general formula: Represents a substituent represented by (1-3); R ⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms; X represents a substituted or unsubstituted aromatic ring; and n3 represents 0. Represents an integer of -10, and when n3 is 2 or more, the plurality of R ⁵ and X may be the same or different from each other.

In General Formula (1-3), X represents a substituted or unsubstituted aromatic ring; R ⁶ , R ⁷ , R ⁸ , and R ⁹ are each independently a hydrogen atom or a C 1-5 carbon atom. N5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R ⁶ , R ⁷ , R ⁸ , R ⁹ and X may be the same or different.

R ¹ represents a substituent. Examples of the substituent are not particularly limited, and may be an alkyl group (preferably an alkyl group having 1 to 10 carbon atoms such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2 -Ethoxyethyl, 1-carboxymethyl, etc.), alkenyl groups (preferably alkenyl groups having 2-20 carbon atoms, such as vinyl, allyl, oleyl, etc.), alkynyl groups (preferably alkynyl groups having 2-20 carbon atoms). , For example, ethynyl, butadiynyl, phenylethynyl, etc.), a cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), an aryl group (preferably An aryl group having 6 to 26 carbon atoms, such as phenyl, -Naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl and the like), a heterocyclic group (preferably a heterocyclic group having 2 to 20 carbon atoms, such as 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2-oxazolyl, etc.), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, such as methoxy, ethoxy, isopropyloxy, benzyloxy, etc.), an aryloxy group (preferably carbon An aryloxy group having 6 to 26 atoms such as phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc., an alkoxycarbonyl group (preferably an alkoxycarbonyl group having 2 to 20 carbon atoms, such as Ethoxycarbonyl, 2-ethylhexyloxycar Nyl, etc.), an amino group (preferably an amino group having 0 to 20 carbon atoms, such as amino, N, N-dimethylamino, N, N-diethylamino, N-ethylamino, anilino, etc.), a sulfonamide group (preferably Is a sulfonamide group having 0 to 20 carbon atoms, such as N, N-dimethylsulfonamide, N-phenylsulfonamide, etc., an acyloxy group (preferably an acyloxy group having 1 to 20 carbon atoms, such as acetyloxy, Benzoyloxy and the like), a carbamoyl group (preferably a carbamoyl group having 1 to 20 carbon atoms, such as N, N-dimethylcarbamoyl, N-phenylcarbamoyl and the like), an acylamino group (preferably an acylamino group having 1 to 20 carbon atoms) For example, acetylamino, benzoylamino, etc.), cyano group, or halogen atom (For example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.) and a hydroxyl group are mentioned.

R ¹ is preferably an alkyl group having 1 to 20 carbon atoms and a hydroxyl group, more preferably a hydroxyl group and a methyl group. R ¹ may further have one or more substituents, and examples of the further substituent include the same substituents as R ¹ .

  n1 represents the integer of 0-4, and 2-4 are preferable.

  n2 represents the integer of 1-5, 1-3 are preferable and 1-2 are more preferable.

R ² represents a substituent represented by the following general formula (1-2).

In general formula (1-2), A represents a substituted or unsubstituted aromatic ring; R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or the following general formula: Represents a substituent represented by (1-3); R ⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms; X represents a substituted or unsubstituted aromatic ring; and n3 represents 0. Represents an integer of -10, and when n3 is 2 or more, the plurality of R ⁵ and X may be the same or different from each other.

A represents a substituted or unsubstituted aromatic ring. The aromatic ring may be a heterocyclic ring containing a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom. Examples of A include benzene ring, indene ring, naphthalene ring, fluorene ring, phenanthrene ring, anthracene ring, biphenyl ring, pyrene ring, pyran ring, dioxane ring, dithiane ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring Morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring, triazine ring and the like. Further, other 6-membered rings or 5-membered rings may be condensed.
A is preferably a benzene ring.
Examples of the substituent that A may have include a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.), an alkyl group, a hydroxyl group, and the like. An alkyl group or a hydroxyl group is preferable, and carbon A C1-C10 alkyl group or a hydroxyl group is more preferable, and a C1-C5 alkyl group or a hydroxyl group is still more preferable.

In General Formula (1-2), R ⁵ represents a single bond or an alkylene group having 1 to 5 carbon atoms, and the alkylene group having 1 to 5 carbon atoms may have a substituent. R ⁵ is preferably an alkylene group having 1 to 4 carbon atoms, and more preferably an alkylene group having 1 to 3 carbon atoms. Examples of the substituent that R ⁵ may have include an alkyl group having 1 to 5 carbon atoms (eg, methyl, ethyl, isopropyl, t-butyl), a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine). Atoms), hydroxyl groups and the like.

  In general formula (1-2), X represents a substituted or unsubstituted aromatic ring. The aromatic ring may be a heterocyclic ring containing a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom. Examples of X include benzene ring, indene ring, naphthalene ring, fluorene ring, phenanthrene ring, anthracene ring, biphenyl ring, pyrene ring, pyran ring, dioxane ring, dithiane ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring Morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring, triazine ring and the like. Further, other 6-membered rings or 5-membered rings may be condensed. X is preferably a benzene ring. Examples of the substituent which X may have are the same as the examples given as the substituent of A.

n3 represents the integer of 0-10, 0-2 are preferable and 0-1 are more preferable. When n3 is an integer of 2 or more, a plurality of groups represented by — (R ⁵ —X) may be the same as or different from each other, and each bond to A. When n3 is 0, a group represented by — (R ⁵ —X) does not exist, and thus a group represented by — (R ⁵ —X) is not bonded to A.

R ³ and R ⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and a substituent represented by the following general formula (1-3). R ³ and R ⁴ are preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a substituent represented by the general formula (1-3), and a hydrogen atom, a methyl group, or a general formula (1-3) The substituent represented is more preferred.

In the substituent represented by the general formula (1-3) that may be contained in the substituent represented by the general formula (1-2), X represents a substituted or unsubstituted aromatic ring; R ⁶ , R ⁷ , R ⁸ , and R ⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; n5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R ⁶ , R ⁷ , R ⁸ , R ⁹ and X may be the same or different from each other.

X in the substituent represented by the general formula (1-3) which may be contained in the substituent represented by the general formula (1-2) has the same meaning as X in the general formula (1-2). The preferred range is also the same.
R ⁶ , R ⁷ , R ⁸ , and R ⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R ³ and R ⁴ are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a hydrogen atom or a methyl group.

  n5 represents an integer of 1 to 11, preferably 1 to 9, and more preferably 1 to 7.

  The substituent represented by the general formula (1-3) that may be contained in the substituent represented by the general formula (1-2) is a substituent represented by the following general formula (1-3 ′). It is preferable that

  The definition of each symbol of the general formula (1-3 ′) that may be included in the substituent represented by the general formula (1-2) is the same as that in the general formula (1-3). The preferable range is also the same.

  The substituent represented by the general formula (1-3) that may be contained in the substituent represented by the general formula (1-2) is a substituent represented by the following general formula (1-3 ″). More preferably, it is a group.

  N4 represents the integer of 0-10 in general formula (1-3 '').

  n4 represents the integer of 0-10, 0-8 are preferable and 0-6 are more preferable.

The substituent represented by the general formula (1-2) is preferably a substituent represented by the following general formula (1-2 ′).

In General Formula (1-2 ′), R ³ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a substituent represented by General Formula (1-3); R ⁵ represents a single bond or Represents an alkylene group having 1 to 5 carbon atoms; X represents a substituted or unsubstituted aromatic ring; n3 represents an integer of 0 to 5; and when n3 is 2 or more, a plurality of R ⁵ and X are They may be the same or different.

  The preferred range of each symbol in the general formula (1-2 ′) is the same as that in the general formula (1-2).

  The general formula (1-2) is preferably represented by the following general formula (1-2 ″).

In general formula (1-2 ″), n3 represents an integer of 0 to 5.
The preferable range of n3 in the general formula (1-2 ″) is the same as the preferable range of n3 in the general formula (1-2).

  Although the specific example of a compound represented by General formula (1) below is shown, it is not limited to the following specific examples.

  In addition, in order to enable the compound represented by the general formula (1) having a different number of hydroxyl groups to be hydrogen-bonded at multiple points, it contains two or more different compounds represented by the general formula (1). It is good also as a mixture. One example is a styrenated phenol in which 1 to 3 moles of styrene are alkylated with respect to phenol, a styrenated phenol in which styrene is further alkylated at the phenyl moiety of the alkylated styrene, and an oligomer of about 2 to 4 mers of styrene. Mention may be made of mixtures with styrenated phenols alkylated to phenol.

The compound represented by the general formula (1) can generally be synthesized by adding 1 equivalent or more of styrenes in the presence of an acid catalyst to 1 equivalent of phenols, and a commercially available product may be used. . Moreover, you may use the mixture obtained by the said synthesis method as it is.
As a commercial item of the compound represented by the general formula (1), “TSP” which is a styrenated phenol manufactured by Sanko Co., Ltd., “PH-25” manufactured by Nikko Paint Chemical Co., Ltd., “manufactured by Seiko Chemical Co., Ltd.” Non-flex WS "etc. are mentioned.

（一般式（２）中、Ｒ¹¹、Ｒ¹³及びＲ¹⁵は、各々独立に、水素原子、炭素数１〜２０のアルキル基、炭素数３〜２０のシクロアルキル基、炭素数２〜２０のアルケニル基または炭素数６〜２０の芳香族基を表す。） -Compound represented by the general formula (2)-

(In the general formula (2), R ¹¹ , R ¹³ and R ¹⁵ are each independently a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an alkyl group having 2 to 20 carbon atoms. Represents an alkenyl group or an aromatic group having 6 to 20 carbon atoms.)

In the general formula (2), R ¹⁵ preferably represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, and 1 to 12 carbon atoms. It is more preferable that it is a C3-C12 cycloalkyl group or a C6-C18 aromatic group, and a C1-C6 alkyl group and a C3-C6 cycloalkyl group are also included. Or an aromatic group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a cyclohexyl group or a phenyl group, and a methyl group, an isopropyl group or a phenyl group. Most preferred.

In general formula (2), R ¹¹ and R ¹³ are each independently preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms. It is more preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aryl group having 6 to 12 carbon atoms, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a carbon atom having 3 to 6 carbon atoms. It is particularly preferably a cycloalkyl group or a phenyl group, more preferably a hydrogen atom, a methyl group, an ethyl group, a cyclohexyl group or a phenyl group, and most preferably a methyl group or a phenyl group.
In General Formula (2), R ¹¹ is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms, and R ¹³ is a hydrogen atom. Or it is preferable that it is a C6-C20 aromatic group. R ¹¹ is an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms, or an aromatic group having 6 to 12 carbon atoms, and R ¹³ is a hydrogen atom or an aromatic group having 6 to 12 carbon atoms. More preferably, it is a group. It is particularly preferable that R ¹¹ is an alkyl group having 1 to 3 carbon atoms or a cyclohexyl group, and R ¹³ is a hydrogen atom or a phenyl group. It is more particularly preferable that R ¹¹ is a methyl group and R ¹³ is a hydrogen atom or a phenyl group.

R ¹⁵ may further have a substituent. The substituent that R ¹⁵ may have is not particularly limited as long as it does not contradict the gist of the present invention, but is preferably a halogen atom, an alkyl group, or an aromatic group, and preferably a halogen atom, carbon number 1 It is more preferably an alkyl group having ˜6 or an aromatic group having 6 to 12 carbon atoms, particularly preferably a chlorine atom, a methyl group, or a phenyl group. In particular, when R ¹⁵ is an alkyl group having 1 to 20 carbon atoms, it preferably has an aromatic group as a substituent, more preferably an aromatic group having 6 to 12 carbon atoms, and a phenyl group. Is particularly preferred. In particular, when R ¹⁵ is an aromatic group having 1 to 20 carbon atoms, it preferably has a halogen atom or an alkyl group having 1 to 20 carbon atoms as a substituent, and a halogen atom or an alkyl group having 1 to 6 carbon atoms. It is more preferable to have a group, and it is particularly preferable to have a chlorine atom or a methyl group.

R ¹¹ and R ¹³ may further have a substituent. The substituent that R ¹¹ may have is not particularly limited as long as it does not contradict the gist of the present invention, but is preferably an aromatic group having 6 to 12 carbon atoms, more preferably a phenyl group. preferable.

  Although the specific example of a compound represented by General formula (2) below is shown, it is not limited to the following specific examples.

  The compound represented by the general formula (2) may be obtained commercially or synthesized by a known method.

-Content-
The cellulose acylate polymer layer used in the present invention has a molecular weight / aromatic number ratio of 300 or less, and the content of the compound represented by formula (1) or (2) is cellulose acylate. The content is preferably 0.5% by mass to 20% by mass, and more preferably 1% by mass to 20% by mass. If it is 1% by mass or more with respect to the cellulose acylate, an effect of improving the elastic modulus is easily obtained, and if it is 20% by mass or less with respect to the cellulose acylate, bleeding occurs when a cellulose acylate film is formed. Out and exudation hardly occur.
The ratio of molecular weight / aromatic number is 300 or less, and the content of the compound represented by the general formula (1) or (2) is particularly preferably 1 to 15% by mass with respect to cellulose acylate. It is preferably 1 to 10% by mass, and more particularly preferably.

<< UV absorber >>
The cellulose acylate polymer layer used in the present invention may contain an ultraviolet absorber. The ultraviolet absorber contributes to improvement of the durability of the polarizer. In particular, in an embodiment in which the cellulose acylate polymer layer of the polarizing plate of the present invention is used as a surface protective film of a polarizing plate disposed on the viewing side of a liquid crystal display device, the addition of an ultraviolet absorber is effective.

  There is no restriction | limiting in particular about the ultraviolet absorber used for this invention. Any ultraviolet absorber conventionally used for cellulose acylate can be used. As an ultraviolet absorber, the compound as described in Unexamined-Japanese-Patent No. 2006-184874 can be mentioned. Polymer ultraviolet absorbers can also be preferably used. In particular, polymer type ultraviolet absorbers described in JP-A-6-148430 are preferably used.

The amount of UV absorber used is not uniform depending on the type of UV absorber, usage conditions, etc., but it is more likely that the UV absorber is contained in a proportion of 1 to 3% by mass with respect to cellulose acylate. preferable.
Examples include ultraviolet absorbers having the following structure, but the ultraviolet absorbers to be added are not limited to these.

《Other additives》
The cellulose acylate polymer layer used in the present invention may further contain at least one other additive as long as the effects of the present invention are not impaired. Examples of other additives include plasticizers other than aromatic ester oligomers (for example, phosphate ester plasticizers, carboxylic ester plasticizers, polycondensation oligomer plasticizers, etc.), retardation humidity durability improvers. , Antioxidants and the like are included.

-Retardation humidity durability improver-
Specific examples of the compound for improving the retardation humidity durability include the following compounds.

-Compound having a hydroxyl group-
Examples of the compound containing a hydroxyl group used in the present invention, more preferably a compound containing a phenolic hydroxyl group, include, for example, Compound A described on pages 13 to 19 of JP-A-2008-89860, and JP-A-2008 A compound represented by general formula (I) described on pages 7 to 9 of No. 233530 can be preferably used.

（一般式（１）中、Ｒａはアルキル基、アルケニル基、アルキニル基、複素環基又はアリール基を表す。Ｘ¹、Ｘ²、Ｘ³及びＸ⁴はそれぞれ独立に単結合又は２価の連結基を表す。Ｒ¹、Ｒ²、Ｒ³及びＲ⁴はそれぞれ独立に水素原子、アルキル基、アルケニル基、アルキニル基、アリール基、アシル基又は複素環基を表す。）

（一般式（４）中、Ｒｂ及びＲｃはそれぞれ独立にアルキル基、アルケニル基、アルキニル基、複素環基又はアリール基を表す。Ｘ⁵及びＸ⁶はそれぞれ独立に単結合又は２価の連結基を表す。Ｒ⁵及びＲ⁶はそれぞれ独立に水素原子、アルキル基、アルケニル基、アルキニル基、アリール基、アシル基又は複素環基を表す。）
Ｘ¹〜Ｘ⁶は、単結合又は２価の連結基を表し、それぞれ同じであっても異なっていてもよく、２価の連結基としては、下記一般式（５）で表される群の中から選ばれることが好ましい。

-Compound having an amino group-
Although it does not specifically limit as a compound containing the amino group used for this invention, It is preferable that it is a compound represented by the following general formula (3) or (4).

(In the general formula (1), Ra represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ¹ , X ² , X ³ and X ⁴ are each independently a single bond or a divalent linkage. R ¹ , R ² , R ³ and R ⁴ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an acyl group or a heterocyclic group.

(In General Formula (4), Rb and Rc each independently represents an alkyl group, an alkenyl group, an alkynyl group, a heterocyclic group or an aryl group. X ⁵ and X ⁶ each independently represent a single bond or a divalent linking group. R ⁵ and R ⁶ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an acyl group or a heterocyclic group.
X ^{1 to} X ⁶ each represents a single bond or a divalent linking group, and may be the same or different from each other, and the divalent linking group is selected from the group represented by the following general formula (5). It is preferable to select from among them.

一般式（６）中、Ｙはメチン基又は窒素原子を表す。Ｑａ、Ｑｂ及びＱｃはそれぞれ独立に単結合又は２価の連結基を表す。Ｒａ、Ｒｂ、及びＲｃはそれぞれ独立に水素原子、置換若しくは無置換のアルキル基、置換若しくは無置換のアルケニル基、置換若しくは無置換のアルキニル基、置換若しくは無置換のアリール基、シアノ基、ハロゲン原子、置換若しくは無置換の複素環基、又は、−Ｎ（Ｒｄ）（Ｒｄ'）を表し、Ｒｄ及びＲｄ'はそれぞれ独立に水素原子又は置換基を表し、Ｒｄ及びＲｄ'は互いに連結して環を形成しても
よい。ＲａとＲｂは互いに連結して環を形成してもよい。Ｘ１は単結合又は下記２価の連結基群（Ｌ）から選択される２価の連結基を表す。Ｘ２は単結合又は２価の連結基を表す。Ｒ¹及びＲ²はそれぞれ独立に水素原子、置換若しくは無置換のアルキル基、置換若しくは無置換のアルケニル基、置換若しくは無置換のアルキニル基、置換若しくは無置換のアリール基、又は、置換若しくは無置換の複素環基を表し、Ｒ¹とＲ²は互いに連結して環を形成してもよい。

（各式中、＊側が一般式（６）で表される化合物中の含窒素芳香環に置換している窒素原子との連結部位であり、Ｒｇは置換若しくは無置換のアルキル基、置換若しくは無置換のアルケニル基、置換若しくは無置換のアルキニル基、置換若しくは無置換のアリール基、又は、置換若しくは無置換の複素環基を表す。） The compound having an amino group is preferably a compound represented by the following general formula (6) having a pyridine or pyrimidine mother nucleus and having an amino group as a substituent at any substitutable position. Is also preferable.

In general formula (6), Y represents a methine group or a nitrogen atom. Qa, Qb and Qc each independently represent a single bond or a divalent linking group. Ra, Rb and Rc are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, a cyano group, or a halogen atom. Represents a substituted or unsubstituted heterocyclic group, or —N (Rd) (Rd ′), Rd and Rd ′ each independently represent a hydrogen atom or a substituent, and Rd and Rd ′ are linked to each other to form a ring; May be formed. Ra and Rb may be connected to each other to form a ring. X1 represents a single bond or a divalent linking group selected from the following divalent linking group group (L). X2 represents a single bond or a divalent linking group. R ¹ and R ² are each independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, or substituted or unsubstituted And R ¹ and R ² may be linked to each other to form a ring.

(In each formula, the * side is a linking site with a nitrogen atom substituted on the nitrogen-containing aromatic ring in the compound represented by the general formula (6), and Rg is a substituted or unsubstituted alkyl group, substituted or unsubstituted. Represents a substituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group.)

-Antioxidant-
In the present invention, known antioxidants for cellulose acylate solutions such as 2,6-di-tert-butyl-4-methylphenol, 4,4′-thiobis- (6-tert-butyl-3-methylphenol) ), 1,1′-bis (4-hydroxyphenyl) cyclohexane, 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, pentaerythrityl-tetrakis A phenolic or hydroquinone antioxidant such as [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] can be added. Further, tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert) It is preferable to add a phosphorus-based antioxidant such as -butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite. The addition amount of the antioxidant is preferably 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the cellulose resin.

<< Method for Producing Cellulose Acylate Polymer Layer >>
There is no restriction | limiting in particular in the method of manufacturing the cellulose acylate type polymer layer used for this invention, It can form into a film using a well-known method. For example, the film may be formed using either a solution casting film forming method or a melt film forming method. From the viewpoint of improving the surface shape of the film, the cellulose acylate polymer layer is preferably produced using a solution casting film forming method. Hereinafter, although the case where the solution casting film forming method is used will be described as an example, the present invention is not limited to the solution casting film forming method. In addition, about the case where a melt film forming method is used, a well-known method can be used.

-Polymer solution-
In the solution casting film forming method, a web can be formed using a cellulose acylate, an aromatic ester oligomer, and a polymer solution (cellulose acylate solution) containing various additives as required. Hereinafter, a polymer solution (hereinafter also referred to as a cellulose acylate solution as appropriate) that can be used in the solution casting film forming method will be described.

-Solvent-
The cellulose acylate used in the present invention is dissolved in a solvent to form a dope, which is cast on a substrate to form a film. At this time, since it is necessary to evaporate the solvent after extrusion or casting, it is preferable to use a volatile solvent.
Furthermore, it does not react with a reactive metal compound or a catalyst, and does not dissolve the casting base material. Two or more solvents may be mixed and used.
Alternatively, cellulose acylate and a reactive metal compound capable of hydrolysis polycondensation may be dissolved in different solvents and then mixed.
Here, an organic solvent having good solubility in cellulose acylate is referred to as a good solvent, and has a main effect on dissolution, and an organic solvent used in a large amount among them is a main (organic) solvent or a main (organic) ) Solvent.

  Examples of the good solvent include ketones such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, ethers such as tetrahydrofuran (THF), 1,4-dioxane, 1,3-dioxolane, 1,2-dimethoxyethane, and the like. In addition to esters such as methyl acid, ethyl formate, methyl acetate, ethyl acetate, amyl acetate, γ-butyrolactone, methyl cellosolve, dimethylimidazolinone, dimethylformamide, dimethylacetamide, acetonitrile, dimethylsulfoxide, sulfolane, nitroethane, Examples include methylene chloride and methyl acetoacetate, and 1,3-dioxolane, THF, methyl ethyl ketone, acetone, methyl acetate and methylene chloride are preferred.

The dope preferably contains 1 to 40% by mass of an alcohol having 1 to 4 carbon atoms in addition to the organic solvent.
After casting the dope on the metal support, the solvent starts to evaporate and the ratio of alcohol increases so that the web (the name of the dope film after casting the cellulose acylate dope on the support is called It is used as a gelling solvent that makes it easy to peel off from the metal support, and when these ratios are small, it promotes dissolution of cellulose acylate of non-chlorine organic solvent There is also a role to suppress gelation, precipitation, and viscosity increase of the reactive metal compound.

Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol, and propylene glycol monomethyl ether.
Of these, methanol and ethanol are preferred because they are excellent in dope stability, have a relatively low boiling point, good drying properties, and no toxicity. Ethanol is most preferred. These organic solvents alone are not soluble in cellulose acylate and are referred to as poor solvents.

In the present invention, cellulose acylate which is a raw material of cellulose acylate contains hydrogen bonding functional groups such as hydroxyl groups, esters, and ketones, and therefore 5 to 30% by mass, more preferably 7 to 25% by mass in the total solvent. More preferably, it contains 10 to 20% by mass of alcohol from the viewpoint of reducing the peeling load from the casting support.
Further, in the present invention, it is effective to contain a small amount of water to increase the solution viscosity and the film strength in the wet film state at the time of drying, or to increase the dope strength at the time of casting the drum method. It may be contained in an amount of 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and particularly 0.2 to 2% by mass.

  Examples of combinations of organic solvents preferably used as the solvent for the polymer solution in the present invention are described in JP-A-2009-262551.

  In addition, if necessary, a non-halogen organic solvent can be used as a main solvent, and detailed description can be found in the Japan Institute of Invention Publication (Publication No. 2001-1745, published on March 15, 2001, Invention Association). There is a description.

The cellulose acylate concentration in the polymer solution in the present invention is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and most preferably 15 to 30% by mass.
The cellulose acylate concentration can be adjusted to a predetermined concentration at the stage of dissolving the cellulose acylate in the solvent. Further, after preparing a low concentration (for example, 4 to 14% by mass) solution in advance, the solution may be concentrated by evaporating the solvent. Furthermore, after preparing a high concentration solution in advance, it may be diluted. Moreover, the density | concentration of a cellulose acylate can also be reduced by adding an additive.

  The timing of adding the additive can be appropriately determined according to the type of the additive. For example, aromatic ester oligomers and UV absorbers can be doped after dissolving UV absorbers in alcohols such as methanol, ethanol, butanol, organic solvents such as methylene chloride, methyl acetate, acetone, dioxolane, or mixed solvents thereof. It may be added or added directly during the dope composition. For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and cellulose acylate to be dispersed and then added to the dope.

  The most preferable solvent that satisfies such conditions and dissolves cellulose acylate, which is a preferred polymer compound, at a high concentration is a mixed solvent having a ratio of methylene chloride: ethyl alcohol of 95: 5 to 80:20. Alternatively, a mixed solvent of methyl acetate: ethyl alcohol 60:40 to 95: 5 is also preferably used.

(1) Dissolution step A step of dissolving the cellulose acylate and additives in an organic solvent mainly containing a good solvent for cellulose acylate while stirring to form a dope, or an additive in a cellulose acylate solution This is a step of mixing a solution to form a dope.
For dissolving cellulose acylate, a method carried out at normal pressure, a method carried out below the boiling point of the main solvent, a method carried out under pressure above the boiling point of the main solvent, JP-A-9-95544, JP-A-9-95557 Alternatively, various dissolution methods such as a cooling dissolution method as described in JP-A-9-95538 and a high-pressure method as described in JP-A-11-21379 can be used. The method of pressurizing at a boiling point or higher is preferred.
The concentration of cellulose acylate in the dope is preferably 10 to 35% by mass. It is preferable that an additive is added to the dope during or after dissolution to dissolve and disperse, and then filtered through a filter medium, defoamed, and sent to the next step with a liquid feed pump.

(2) Casting process An endless metal belt, such as a stainless steel belt or a rotating metal drum, that feeds the dope to a pressure die through a liquid feed pump (for example, a pressurized metering gear pump) and transfers it indefinitely. This is a step of casting the dope from the pressure die slit to the casting position on the support.
A pressure die that can adjust the slit shape of the die base and facilitates uniform film thickness is preferred. The pressure die includes a coat hanger die and a T die, and any of them is preferably used. The surface of the metal support is a mirror surface. In order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided and stacked. Or it is also preferable to obtain the film of a laminated structure by the co-casting method which casts several dope simultaneously.

(3) Solvent evaporation process A web (which is a state before it becomes a finished product of a cellulose acylate polymer layer and still contains a lot of solvent) is heated on a metal support, and the web is then transferred from the metal support to the web. This is a step of evaporating the solvent until it becomes peelable.
To evaporate the solvent, there are a method of blowing air from the web side and / or a method of transferring heat from the back side of the metal support by a liquid, a method of transferring heat from the front and back by radiant heat, etc. However, drying efficiency is preferable. A method of combining them is also preferable. In the case of backside liquid heat transfer, it is preferable to heat at or below the boiling point of the main solvent of the organic solvent used in the dope or the organic solvent having the lowest boiling point.

(4) Peeling process It is the process of peeling the web which the solvent evaporated on the metal support body in a peeling position. The peeled web is sent to the next process. In addition, if the residual solvent amount (the following formula) of the web at the time of peeling is too large, peeling is difficult, or conversely, if the film is peeled off after being sufficiently dried on the metal support, a part of the web is in the middle. It may come off.
Here, there is a gel casting method (gel casting) as a method for increasing the film forming speed (the film forming speed can be increased by peeling while the residual solvent amount is as large as possible). For example, there are a method in which a poor solvent for cellulose acylate is added to the dope and the dope is cast and then gelled, a method in which the temperature of the metal support is lowered and gelled. By gelling on the metal support and increasing the strength of the film at the time of peeling, the speed of film formation can be increased by speeding up the peeling.
The amount of residual solvent during peeling of the web on the metal support is preferably within a range of 5 to 150% by mass depending on the strength of drying conditions, the length of the metal support, etc., but the amount of residual solvent is larger. In the case of peeling at the time, the amount of residual solvent at the time of peeling is determined in consideration of economic speed and quality. In the present invention, the temperature at the peeling position on the metal support is preferably -50 to 40 ° C, more preferably 10 to 40 ° C, and most preferably 15 to 30 ° C.

The residual solvent amount of the web at the peeling position is preferably 10 to 150% by mass, and more preferably 10 to 120% by mass.
The amount of residual solvent can be represented by the following formula.
Residual solvent amount (% by mass) = [(MN) / N] × 100
Here, M is the mass of the web at an arbitrary point in time, and N is the mass when the mass M is dried at 110 ° C. for 3 hours.

(5) After the drying or heat treatment process, the stretching process, and the peeling process, a drying apparatus that alternately conveys the web through rolls arranged in the drying apparatus, and / or a tenter that clips and conveys both ends of the web with clips. It is preferred to dry the web using an apparatus.

When heat treatment is performed in the present invention, the heat treatment temperature is less than Tg-5 ° C, preferably Tg-20 ° C or more and less than Tg-5 ° C, and preferably Tg-15 ° C or more and less than Tg-5 ° C. More preferred.
The heat treatment temperature is preferably 30 minutes or less, more preferably 20 minutes or less, and particularly preferably about 10 minutes.

  As a means for drying and heat treatment, hot air is generally blown on both sides of the web, but there is also a means for heating by applying a microwave instead of the wind. The temperature, air volume, and time vary depending on the solvent used, and the conditions may be appropriately selected according to the type and combination of the solvents used.

  The stretching process may be performed in one direction of MD (longitudinal direction) and TD (transverse direction), or may be biaxially stretched in both directions. Biaxial stretching is preferred. Stretching may be performed in one stage or in multiple stages. The tensile elastic modulus is adjusted to the above range by adjusting the type of cellulose acylate to be used and the acyl substitution degree, selecting the type of additive, or adjusting the ratio thereof. Can do.

The stretching ratio in stretching in the film transport direction MD is preferably 0 to 20%, more preferably 0 to 15%, and particularly preferably 0 to 10%. The stretch ratio (elongation) of the web during stretching can be achieved by the difference in peripheral speed between the metal support speed and the stripping speed (stripping roll draw). For example, when an apparatus having two nip rolls is used, the film can be preferably stretched in the conveying direction (longitudinal direction) by increasing the rotational speed of the nip roll on the outlet side rather than the rotational speed of the nip roll on the inlet side. it can. By performing such stretching, the tensile modulus of MD can be adjusted.
Here, the “stretch ratio (%)” means that obtained by the following formula.
Stretch ratio (%) = 100 × {(Length after stretching) − (Length before stretching)} / Length before stretching

The stretching ratio in stretching in the direction TD perpendicular to the film conveying direction is preferably 0 to 30%, more preferably 1 to 20%, and particularly preferably 20 to 15%.
In addition, in this invention, it is preferable to extend | stretch using a tenter apparatus as a method of extending | stretching to the direction TD orthogonal to a film conveyance direction.

  In the case of biaxial stretching, a desired retardation value can be obtained by relaxing the length in the longitudinal direction, for example, 0.8 to 1.0 times. The draw ratio is set according to the target optical characteristics. When producing a cellulose acylate polymer layer, it can be uniaxially stretched in the longitudinal direction.

  It is preferable for the temperature during stretching to be Tg or less because the tensile elastic modulus in the stretching direction increases. The stretching temperature is preferably Tg-50 ° C to Tg, and more preferably Tg-30 ° C to Tg-5 ° C. On the other hand, when stretched under the above temperature conditions, the tensile elastic modulus in the stretching direction increases, while the tensile elastic modulus in the direction orthogonal thereto tends to decrease. Therefore, in order to increase the tensile elastic modulus in both the MD and TD directions by stretching, it is preferable to perform stretching in both directions, that is, biaxial stretching in the above temperature range.

  In addition, you may dry after an extending process. When drying after the stretching step, the drying temperature, the amount of drying air and the drying time differ depending on the solvent used, and the drying conditions may be appropriately selected according to the type and combination of the solvents used. In the present invention, the drying temperature after the stretching step is preferably lower than the stretching temperature in the stretching step from the viewpoint of increasing the front contrast when the film is incorporated into a liquid crystal display device.

(6) Winding The length of the film obtained as described above is preferably wound at 100 to 10000 m per roll, more preferably 500 to 7000 m, and further preferably 1000 to 6000 m. . The width of the film is preferably 0.5 to 5.0 m, more preferably 1.0 to 3.0 m, and still more preferably 1.0 to 2.5 m. When winding, it is preferable to give knurling to at least one end, the knurling width is preferably 3 mm to 50 mm, more preferably 5 mm to 30 mm, and the height is preferably 0.5 to 500 μm, more preferably 1 to 200 μm. is there. This may be a single push or a double push.

  The web thus obtained can be wound up to obtain a cellulose acylate polymer layer.

<< Layer structure of cellulose acylate polymer layer >>
The cellulose acylate polymer layer used in the present invention may be a single layer film or may have a laminated structure of two or more layers. For example, a laminated structure composed of two layers of a core layer and an outer layer (sometimes referred to as a surface layer or a skin layer) or a laminated structure composed of three layers of an outer layer, a core layer, and an outer layer are also preferable. It is also preferable that the laminated structure be formed by co-casting.
When the cellulose acylate polymer layer used in the present invention has a laminated structure of two or more layers, it is preferable to add a matting agent to the outer layer. As the matting agent, for example, those described in JP-A-2011-127045 can be used, and for example, silica particles having an average particle size of 20 nm can be used.

<Polyester-based polymer layer>
The polyester used for forming the polyester polymer layer used in the present invention is not particularly limited, and a known polyester can be used. Specific examples include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, and the like. Among these, it is particularly preferable to use polyethylene terephthalate from the viewpoint of cost and mechanical strength. In addition, when a 1st polarizing plate protective layer or a 2nd polarizing plate protective layer consists of a polyethylene terephthalate, it is preferable that the refractive index of a polyester-type polymer layer is 1.62 or more and 1.68 or less.

  In the embodiment in which the first polarizing plate protective layer has an ultraviolet absorbing ability, it is preferable to add an ultraviolet absorber to the polyester. The amount of the ultraviolet absorber added is such that the light transmittance at a wavelength of 380 nm in the support containing the ultraviolet absorber and polyester is 3.00% or less. As described above, in order to make the light transmittance 3.00% or less, it is preferable that the ratio of the ultraviolet absorber to the total amount of the polyester is 0.1% by mass or more and 5.0% by mass or less. More preferably, it is 0.2 mass% or more and 3.0 mass% or less, Most preferably, it is 0.3 mass% or more and 2.0 mass% or less. If the addition amount of the ultraviolet absorber is within the above range, the light transmittance can be suppressed to 3% or less, and therefore, for example, it is possible to prevent the dye contained in the infrared blocking layer from being decomposed by ultraviolet rays. The light transmittance is preferably as small as possible within the above range.

  The method of adding the ultraviolet absorber to the polyester is not particularly limited, and examples thereof include kneading the polyester in the step of polymerizing the polyester and the step of melting the polyester before forming the support. . Especially, if it knead | mixes in a polyester in a melt | fusion process, it can work, without reducing the polymerization degree of polyester. The kneading of the ultraviolet absorber can be performed by a method of directly adding the compound powder, a master batch method, or the like. As the ultraviolet absorber, an ultraviolet absorber having a structural formula of the following general formula (1) is preferable, and benzophenone, benzotriazole, salicylic acid ester, cyanoacrylate, benzoxazine, and triazine coumarin copolymers. System UV absorbers and the like. In addition, as a well-known technique of an ultraviolet absorber, all the technical matters described in JP-A-2002-244247 can be applied.

<Acrylic polymer layer>
Examples of the acrylic polymer layer used in the present invention include a layer formed from a composition containing a (meth) acrylic acid resin as a main component.
The repeating structural unit of the (meth) acrylic resin is not particularly limited. The (meth) acrylic resin preferably has a repeating structural unit derived from a (meth) acrylic acid ester monomer as a repeating structural unit.

  The (meth) acrylic resin is a concept including both a methacrylic resin and an acrylic resin. The (meth) acrylic resin also includes acrylate / methacrylate derivatives, particularly acrylate / methacrylate (co) polymers.

  The (meth) acrylic resin is polymerized by repeating at least one selected from a hydroxyl group-containing monomer, an unsaturated carboxylic acid and a monomer represented by the following general formula (201) as a repeating structural unit. It may contain repeating structural units to be constructed.

Formula (201)
CH ₂ = C (X) R ²⁰¹

(In the formula, R ²⁰¹ represents a hydrogen atom or a methyl group, and X represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group, a —CN group, a —CO—R ²⁰² group, or —O—CO—R. ²⁰³ represents a group, and R ²⁰² and R ²⁰³ represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)

  Although it does not specifically limit as (meth) acrylic acid ester, For example, acrylics, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, benzyl acrylate, etc. Acid esters; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, and benzyl methacrylate; May be used alone or in combination of two or more. Among these, methyl methacrylate is particularly preferable from the viewpoint of excellent heat resistance and transparency. When (meth) acrylic acid ester is used, the content ratio in the monomer component to be subjected to the polymerization step is preferably 10 to 100% by mass, more preferably 10 to 10%, in order to sufficiently exhibit the effects of the present invention. 100 mass%, More preferably, it is 40-100 mass%, Most preferably, it is 50-100 mass%.

Although it does not specifically limit as a hydroxyl-containing monomer, For example, 2- (hydroxyalkyl) acrylate ester, such as alpha-hydroxymethyl styrene, alpha-hydroxyethyl styrene, methyl 2- (hydroxyethyl) acrylate; 2- (hydroxyalkyl) acrylic acid such as (hydroxyethyl) acrylic acid; and the like. These may be used alone or in combination of two or more.
In the case of using a hydroxyl group-containing monomer, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by mass, more preferably 0 to 20%, in order to sufficiently exhibit the effects of the present invention. It is 0 mass%, More preferably, it is 0-15 mass%, Most preferably, it is 0-10 mass%.

Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, crotonic acid, α-substituted acrylic acid, α-substituted methacrylic acid and the like. These may be used alone or in combination of two or more. May be. Among these, acrylic acid and methacrylic acid are preferable in that the effects of the present invention are sufficiently exhibited.
When using an unsaturated carboxylic acid, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by mass, more preferably 0 to 20% by mass, in order to sufficiently exhibit the effects of the present invention. %, More preferably 0 to 15% by mass, particularly preferably 0 to 10% by mass.

Examples of the monomer represented by the general formula (201) include styrene, vinyl toluene, α-methyl styrene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, and vinyl acetate. These are used alone. Or two or more of them may be used in combination. Among these, styrene and α-methylstyrene are particularly preferable in that the effects of the present invention are sufficiently exhibited.
When the monomer represented by the general formula (201) is used, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by mass in order to sufficiently exhibit the effects of the present invention. More preferably, it is 0-20 mass%, More preferably, it is 0-15 mass%, Most preferably, it is 0-10 mass%.

The monomer component may form a lactone ring after polymerization. In that case, it is preferable to polymerize the monomer component to obtain a polymer having a hydroxyl group and an ester group in the molecular chain.
The form of the polymerization reaction for polymerizing the monomer component to obtain a polymer having a hydroxyl group and an ester group in the molecular chain is preferably a polymerization form using a solvent, and solution polymerization is particularly preferred.
For example, a lactone ring structure described in JP 2007-316366 A, JP 2005-189623 A, WO 2007/032304, WO 2006/025445 is also preferable. It is.

<Lactone ring-containing polymer>
The lactone ring-containing polymer is not particularly limited as long as it has a lactone ring, but preferably has a lactone ring structure represented by the following general formula (401).

General formula (401):

In the general formula (401), R ⁴⁰¹ , R ⁴⁰² and R ⁴⁰³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms, and the organic residue may contain an oxygen atom. . Here, the organic residue having 1 to 20 carbon atoms is preferably a methyl group, an ethyl group, an isopropyl group, an n-butyl group, a t-butyl group, or the like.

  The content ratio of the lactone ring structure represented by the general formula (401) in the structure of the lactone ring-containing polymer is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, and still more preferably 10 to 60% by mass. %, Particularly preferably 10 to 50% by mass. By setting the content ratio of the lactone ring structure to 5% by mass or more, the heat resistance and surface hardness of the obtained polymer tend to be improved, and by setting the content ratio of the lactone ring structure to 90% by mass or less. The moldability of the obtained polymer tends to be improved.

  The method for producing the lactone ring-containing polymer is not particularly limited, but preferably, after obtaining a polymer (p) having a hydroxyl group and an ester group in the molecular chain by a polymerization step, the obtained polymer ( It is obtained by carrying out a lactone cyclization condensation step for introducing a lactone ring structure into the polymer by heat-treating p).

  The weight average molecular weight of the lactone ring-containing polymer is preferably 1,000 to 2,000,000, more preferably 5,000 to 1,000,000, still more preferably 10,000 to 500,000, particularly preferably. 50,000 to 500,000.

  The lactone ring-containing polymer has a mass reduction rate within a range of 150 to 300 ° C. in dynamic TG measurement, preferably 1% or less, more preferably 0.5% or less, and still more preferably 0.3% or less. It is good. As a method for measuring dynamic TG, the method described in JP-A-2002-138106 can be used.

  Since the lactone ring-containing polymer has a high cyclization condensation reaction rate, there is little dealcoholization reaction in the production process of the molded product, and bubbles and silver stripes (silver streaks) are formed in the molded product after molding due to the alcohol. The disadvantage of entering can be avoided. Furthermore, since the lactone ring structure is sufficiently introduced into the polymer due to a high cyclization condensation reaction rate, the obtained lactone ring-containing polymer has high heat resistance.

  The lactone ring-containing polymer has a coloring degree (YI) of preferably 6 or less, more preferably 3 or less, still more preferably 2 or less, and particularly preferably 1 or less when a chloroform solution having a concentration of 15% by mass is used. . If the degree of coloring (YI) is 6 or less, problems such as loss of transparency due to coloring are unlikely to occur, and therefore, it can be preferably used in the present invention.

  The lactone ring-containing polymer has a 5% mass reduction temperature in thermal mass spectrometry (TG) of preferably 330 ° C. or higher, more preferably 350 ° C. or higher, and still more preferably 360 ° C. or higher. The 5% mass reduction temperature in thermal mass spectrometry (TG) is an indicator of thermal stability, and by setting it to 330 ° C. or higher, sufficient thermal stability tends to be exhibited. The thermal mass spectrometry can use the apparatus for measuring the dynamic TG.

  The lactone ring-containing polymer has a glass transition temperature (Tg) of preferably 115 ° C. or higher, more preferably 125 ° C. or higher, further preferably 130 ° C. or higher, particularly preferably 135 ° C. or higher, and most preferably 140 ° C. or higher. .

  The total amount of residual volatile components contained in the lactone ring-containing polymer is preferably 5,000 ppm or less, more preferably 2,000 ppm or less, still more preferably 1,500 ppm, and particularly preferably 1,000 ppm. If the total amount of residual volatile components is 5,000 ppm or less, it is preferable because coloring defects due to alteration during molding, foaming, and molding defects such as silver streak are unlikely to occur.

  The lactone ring-containing polymer has a total light transmittance of 85% or more, more preferably 88% or more, and still more preferably measured by a method based on ASTM-D-1003 for a molded product obtained by injection molding. 90% or more. The total light transmittance is an index of transparency, and when it is 85% or more, the transparency tends to be improved.

In the case of a polymerization form using a solvent, the polymerization solvent is not particularly limited. For example, aromatic hydrocarbon solvents such as toluene, xylene, and ethylbenzene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ether solvents such as tetrahydrofuran Etc., and only one of these may be used, or two or more may be used in combination.
In the first aspect of the production method of the present invention, the (meth) acrylic resin is dissolved in an organic solvent and cast by solution casting. Therefore, the organic solvent at the time of synthesizing the (meth) acrylic resin is There is no limitation as compared with the case of performing melt film formation, and synthesis may be performed using an organic solvent having a high boiling point.

During the polymerization reaction, a polymerization initiator may be added as necessary. Although it does not specifically limit as a polymerization initiator, For example, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-t-butyl peroxide, lauroyl peroxide, benzoyl peroxide, t-butylperoxyisopropyl carbonate, t-amyl Organic peroxides such as peroxy-2-ethylhexanoate; 2,2′-azobis (isobutyronitrile), 1,1′-azobis (cyclohexanecarbonitrile), 2,2′-azobis (2, Azo compounds such as 4-dimethylvaleronitrile), and the like. These may be used alone or in combination of two or more. The amount of the polymerization initiator used is not particularly limited as long as it is appropriately set according to the combination of the monomers used and the reaction conditions.
The weight average molecular weight of the polymer can be adjusted by adjusting the amount of the polymerization initiator.

  When performing the polymerization, it is preferable to control the concentration of the produced polymer in the polymerization reaction mixture to be 50% by mass or less in order to suppress gelation of the reaction solution. Specifically, when the concentration of the produced polymer in the polymerization reaction mixture exceeds 50% by mass, it is preferable that the polymerization solvent is appropriately added to the polymerization reaction mixture and controlled to be 50% by mass or less. . The concentration of the produced polymer in the polymerization reaction mixture is more preferably 45% by mass or less, still more preferably 40% by mass or less.

  The form in which the polymerization solvent is appropriately added to the polymerization reaction mixture is not particularly limited, and the polymerization solvent may be added continuously or intermittently. By controlling the concentration of the produced polymer in the polymerization reaction mixture in this way, the gelation of the reaction solution can be more sufficiently suppressed. The polymerization solvent to be added may be the same type of solvent used during the initial charging of the polymerization reaction or may be a different type of solvent, but is the same as the solvent used during the initial charging of the polymerization reaction. It is preferable to use different types of solvents. Further, the polymerization solvent to be added may be only one type of solvent or a mixed solvent of two or more types.

As the acrylic polymer layer used in the present invention, a conventionally known optical film can also be used.
As an optical film used as an acrylic polymer layer, an optical film made of a (meth) acrylic resin containing a styrene resin described in Japanese Patent No. 4570042 and a glutarimide ring structure described in Japanese Patent No. 5041532 are mainly used. An optical film made of a (meth) acrylic resin in the chain, an optical film made of a (meth) acrylic resin having a lactone ring structure described in JP2009-122664A, and a glutar described in JP2009-139754A An optical film made of a (meth) acrylic resin having an acid anhydride unit can be used.

<< Method for Producing Acrylic Polymer Layer >>
There is no restriction | limiting in particular as a manufacturing method of the acryl-type polymer layer used for this invention, It can manufacture by a well-known method. As an example, the manufacturing method similar to the manufacturing method of the above-mentioned cellulose acylate film can be mentioned.

  As the acrylic polymer layer, from the viewpoint of thinning, a thin layer formed by coating or the like may be used, and the thin layer does not necessarily have a self-supporting property. For example, after the acrylic polymer layer is formed on the temporary support, the acrylic polymer layer is bonded to the polarizer directly or via an adhesive layer together with the temporary support. It may be formed by peeling and transferring.

<Characteristics of acrylic polymer layer>

  The acrylic polymer layer used in the present invention preferably has an Rth of −10 to 10 nm, more preferably −8 to 8 nm, and particularly preferably −6 to 6 nm.

<Cycloolefin polymer layer>
Examples of the cycloolefin polymer layer used in the present invention include a layer formed from a composition containing as a main component a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule. .
In the present invention, the layer formed from the composition containing as a main component a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule is a cyclic aliphatic group for imparting low moisture permeability. Contains a compound having a hydrocarbon group and an unsaturated double bond group in the molecule, and further contains a polymerization initiator, a translucent particle, a fluorine-containing or silicone compound, and a solvent as necessary. It is preferable to form the composition by coating, drying, and curing directly on the support or through another layer. Each component will be described below. In addition, the main component of a composition or a layer means the component which occupies 50 mass% or more of the composition or the layer.

<< Compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule >>
A compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule functions as a binder. In addition, a compound having a cycloaliphatic hydrocarbon group and an unsaturated double bond group can function as a curing agent, and can improve the strength and scratch resistance of the coating film, while at the same time being low. Moisture permeability can be imparted. By using such a compound, low moisture permeability and high film strength can be realized. Although the details are not clear, by using a compound having a cycloaliphatic hydrocarbon group in the molecule, a hydrophobic cycloaliphatic hydrocarbon group is introduced into the low moisture-permeable layer, and is hydrophobized. Prevents uptake of molecules and reduces moisture permeability. Moreover, by having an unsaturated double bond group in a molecule | numerator, a crosslinking point density is raised and the diffusion path | route of the water molecule in a low moisture-permeable layer is restrict | limited. Increasing the crosslink point density also has the effect of relatively increasing the density of the cyclic aliphatic hydrocarbon group, making the inside of the low moisture permeable layer more hydrophobic, preventing the adsorption of water molecules, and reducing the moisture permeability. it is conceivable that.
In order to increase the crosslinking point density, the number of unsaturated double bond groups in the molecule is more preferably 2 or more.

The cyclic aliphatic hydrocarbon group is preferably a group derived from an alicyclic compound having 7 or more carbon atoms, more preferably a group derived from an alicyclic compound having 10 or more carbon atoms, and further preferably Is a group derived from an alicyclic compound having 12 or more carbon atoms.
The cycloaliphatic hydrocarbon group is particularly preferably a group derived from a polycyclic compound such as bicyclic or tricyclic.
More preferably, the central skeleton of the compound described in the claims of JP-A No. 2006-215096, the central skeleton of the compound described in JP-A No. 2001-10999, or the skeleton of an adamantane derivative may be used.

  As the cyclic aliphatic hydrocarbon group (including a linking group), a group represented by any one of the following general formulas (I) to (V) is preferable, and the following general formula (I), (II), or (IV) Is more preferable, and a group represented by the following general formula (I) is more preferable.

In general formula (I), L and L ′ each independently represent a divalent or higher valent linking group and are not divalent simultaneously. n represents an integer of 1 to 3.

In general formula (II), L and L ′ each independently represent a divalent or higher linking group and are not divalent simultaneously. n represents an integer of 1 to 2.

In general formula (III), L and L ′ each independently represent a divalent or higher linking group and are not divalent simultaneously. n represents an integer of 1 to 2.

  In general formula (IV), L and L ′ each independently represent a divalent or higher valent linking group, and L ″ represents a hydrogen atom or a divalent or higher valent linking group.

  In general formula (V), L and L ′ each independently represent a divalent or higher linking group and are not divalent simultaneously.

  Specific examples of the cyclic aliphatic hydrocarbon group include norbornyl, tricyclodecanyl, tetracyclododecanyl, pentacyclopentadecanyl, adamantyl, diamantanyl and the like.

Examples of the unsaturated double bond group include polymerizable functional groups 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.

A compound having a cycloaliphatic hydrocarbon group and having 3 or more unsaturated double bond groups in the molecule has the above-described cycloaliphatic hydrocarbon group and the group having an unsaturated double bond as a linking group. It is comprised by connecting via.
As the linking group, a single bond, an alkylene group having 1 to 6 carbon atoms which may be substituted, an amide group which may be substituted at the N-position, a carbamoyl group which may be substituted at the N-position, or an ester group , An oxycarbonyl group, an ether group, and the like, and groups obtained by combining these.

These compounds include, for example, polyols such as diols and triols having the above cyclic aliphatic hydrocarbon groups, and carboxylic acids and carboxylic acid derivatives of compounds having (meth) acryloyl groups, vinyl groups, styryl groups, allyl groups, etc. It can be easily synthesized by a one-step or two-step reaction with an epoxy derivative, an isocyanate derivative or the like.
Preferably, compounds such as (meth) acrylic acid, (meth) acryloyl chloride, (meth) acrylic anhydride, glycidyl (meth) acrylate, and compounds described in WO2012 / 00316A (eg, 1,1-bis ( (Acryloxymethyl) ethyl isocyanate) can be synthesized by reacting with a polyol having the above cyclic aliphatic hydrocarbon group.

  Preferred specific examples of the compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group are shown below, but the present invention is not limited thereto.

Examples of cycloolefin polymers used in the present invention include (1) norbornene polymers, (2) monocyclic olefin polymers, (3) cyclic conjugated diene polymers, (4) vinyl alicyclic polymers. There are hydrocarbon polymers and hydrides of (1) to (4).
Preferred cycloolefin polymer for the present invention is an addition (co) polymer cyclic polyolefin resin containing at least one repeating unit represented by the following general formula (102) and, if necessary, the general formula (101) An addition (co) polymer cyclic polyolefin resin further comprising at least one repeating unit. A ring-opening (co) polymer containing at least one cyclic repeating unit represented by the general formula (103) can also be suitably used.

Formula (101)

General formula (102)

General formula (103)

In formulas (101) to (103), m represents an integer of 0 to 4. R ^{1 to} R ⁶ are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, X ^{1 to} X ³ and Y ^{1 to} Y ³ are a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, and a halogen atom. substituted hydrocarbon group having 1 to 10 carbon _{atoms, - (CH 2) n COOR} 11, - (CH 2) n OCOR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - ( _{CH 2) n CN, - (} CH 2) n CONR 13 R 14, - (CH 2) n NR 13 R 14, - (CH 2) n OZ, - (CH 2) n W, or X ¹ and Y ¹ Alternatively, (—CO) ₂ O and (—CO) ₂ NR ¹⁵ composed of X ² and Y ² or X ³ and Y ³ are shown. R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with a halogen, and W is SiR ¹⁶ _p. D _3-p (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom, —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), n is an integer of 0 to 10 Show.

Norbornene polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19807, JP-A-2003-115767, or JP-A-2004-309799. As disclosed in No. 1, etc., a polycyclic unsaturated compound is produced by addition polymerization or metathesis ring-opening polymerization and then hydrogenation. In the norbornene-based polymer used in the present invention, R ^{5 to} R ⁶ are preferably a hydrogen atom or —CH ₃ , X ³ and Y ³ are preferably a hydrogen atom, Cl, —COOCH ₃ , and other groups are appropriately selected. Is done. This norbornene-based resin is sold under the trade name Arton G or Arton F by JSR Corporation, and from Zeon Corporation, Zeonor ZF14, ZF16, Zeonex 250 or Zeonex. They are commercially available under the trade name 280 and can be used.

  Norbornene-based addition (co) polymers are disclosed in JP-A No. 10-7732, JP-T-2002-504184, U.S. Published Patent No. 200429129157A1 or WO2004 / 070463A1. It can be obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. If necessary, norbornene-based polycyclic unsaturated compounds and ethylene, propylene, butene; conjugated dienes such as butadiene and isoprene; nonconjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride It is also possible to carry out addition polymerization with linear diene compounds such as acid, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate and vinyl chloride. This norbornene-based addition (co) polymer is marketed by Mitsui Chemicals, Inc. under the name of Apel, and has different glass transition temperatures (Tg) such as APL8008T (Tg70 ° C), APL6013T (Tg125 ° C) or APL6015T ( Grades such as Tg145 ° C). Pellets such as TOPAS 8007, 6013, and 6015 are sold by Polyplastics Co., Ltd. Further, Appear 3000 is sold by Ferrania.

  In the present invention, the glass transition temperature (Tg) of the cyclic polyolefin-based resin is not limited, but a high-Tg cyclic polyolefin resin such as 200 to 400 ° C. can also be used.

A conventionally known optical film can also be used as the cycloolefin-based polymer layer used in the present invention.
Examples of the optical film used as the cycloolefin-based polymer layer include cyclic olefin-based resin films described in paragraph [0029] and subsequent paragraphs of JP-A-2009-237376, Japanese Patent No. 4881827, and JP-A-2008-063536. A cyclic olefin resin film containing an additive for reducing Rth described in Japanese Unexamined Patent Application Publication Nos. 2008-102475 and 2007-256882 can be used.

<< Method for producing cycloolefin-based polymer layer >>
The method for producing the cycloolefin polymer layer used in the present invention is the same as the method for producing the acrylic polymer layer described above.

<Layer containing liquid crystalline compound>
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 disk-like 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. It is more preferable to use a rod-like liquid crystal compound or a disk-like liquid crystal compound having a reactive group because temperature change and humidity change can be reduced, and at least one of the reactive groups in one liquid crystal molecule is 2 or more. More preferably it is. The liquid crystalline compound may be a mixture of two or more, and in that case, at least one preferably has two or more reactive groups.
As the rod-like liquid crystalline compound, for example, those described in JP-A-11-513019 and JP-A-2007-279688 can be preferably used, and as the discotic liquid crystalline compound, for example, JP-A-2007- Those described in Japanese Patent No. 108732 and Japanese Patent Application Laid-Open No. 2010-244038 can be preferably used, but are not limited thereto.
In the aspect in which the first polarizing plate protective layer or the second polarizing plate protective layer is composed of a liquid crystal layer formed by immobilizing a liquid crystal compound, the liquid crystal layer can be formed by various methods using an alignment film. There is no limit.

  It is also preferable that the liquid crystal compound has two or more reactive groups having different polymerization conditions. In this case, it is possible to produce a retardation layer containing a polymer having an unreacted reactive group by selecting conditions and polymerizing only a part of plural types of reactive groups. The polymerization conditions used may be the wavelength range of ionizing radiation used for polymerization immobilization, or the difference in polymerization mechanism used, but preferably a radical reaction group and a cationic reaction that can be controlled by the type of initiator used. A combination of groups is good. A combination in which the radical reactive group is an acryl group and / or a methacryl group and the cationic group is a vinyl ether group, an oxetane group and / or an epoxy group is particularly preferable because the reactivity can be easily controlled.

<Adhesive layer>
An adhesive is usually used for laminating each layer. In the present invention, the adhesive layer between the polarizer and the polarizing plate protective layer can have a thickness of about 0.01 to 30 μm, preferably 0.01 to 10 μm, and more preferably 0.05 to 0.05. 5 μm. If the thickness of the adhesive layer is within this range, no adhesion or practical problem will be obtained without causing floating or peeling between the laminated polarizing plate protective layer and the polarizer.
The adhesive layer in the present invention is a layer containing an adhesive as a main component (for example, occupying 80% by mass or more of the adhesive layer), and may contain other additives.
The moisture permeability at 40 ° C. and 90% relative humidity of the adhesive layer in the present invention is preferably 12 g / m ² / day or more, more preferably 12 to 3500 g / m ² / day, More preferably, it is -1200 g / m < ² > / day.
The adhesive layer in the present invention preferably has substantially no optical properties. Having substantially no optical properties means that Re (550 nm) and Rth (550 nm) are ± 2 nm or less.
The adhesive preferably used in the present invention will be described below, but it goes without saying that the present invention is not limited to these.

<< Water-based adhesive >>
As one of the preferable adhesives, an aqueous adhesive, that is, an adhesive component dissolved or dispersed in water can be exemplified, and an adhesive made of an aqueous polyvinyl alcohol resin solution is preferably used.
In an adhesive comprising an aqueous polyvinyl alcohol resin solution, the polyvinyl alcohol resin includes a vinyl alcohol homopolymer obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, as well as vinyl acetate and this. Examples include vinyl alcohol copolymers obtained by saponifying a copolymer with other polymerizable monomers, and modified polyvinyl alcohol polymers obtained by partially modifying their hydroxyl groups.
To this adhesive, a polyvalent aldehyde, a water-soluble epoxy compound, a melamine compound, a zirconia compound, a zinc compound, a glyoxylate and the like may be added as a crosslinking agent. When an aqueous adhesive is used, the thickness of the adhesive layer obtained therefrom is usually 1 μm or less.

<< Curable adhesive composition >>
Another preferred adhesive is a curable adhesive composition containing an epoxy compound that is cured by irradiation with active energy rays or heating. Here, the curable epoxy compound has at least two epoxy groups in the molecule. In this case, the adhesive between the polarizer and the protective film is applied to the coating layer of the adhesive composition by irradiating active energy rays or applying heat, and a curable epoxy compound contained in the adhesive. It can carry out by the method of hardening. Curing of the epoxy compound is generally performed by cationic polymerization of the epoxy compound. Further, from the viewpoint of productivity, this curing is preferably performed by irradiation with active energy rays.
When a curable adhesive is used, the thickness of the adhesive layer obtained therefrom is usually about 0.5 to 5 μm.

  When using a curable adhesive, after bonding a polarizing plate protective layer using a bonding roll, drying is performed as necessary, and the curable adhesive is irradiated with an active energy ray or heated. Is cured. The light source of the active energy ray is not particularly limited, but an active energy ray having a light emission distribution at a wavelength of 400 nm or less is preferable. A microwave excited mercury lamp, a metal halide lamp, or the like is preferably used.

  From the viewpoint of weather resistance, refractive index, cationic polymerizability, etc., the epoxy compound contained in the curable adhesive composition is preferably one that does not contain an aromatic ring in the molecule. Examples of epoxy compounds that do not contain an aromatic ring in the molecule include hydrogenated epoxy compounds, alicyclic epoxy compounds, and aliphatic epoxy compounds. Epoxy compounds suitably used for such a curable adhesive composition are described in detail in, for example, Japanese Patent Application Laid-Open No. 2004-245925.

<< Layer formed by polymerizing ethylenically unsaturated monomer >>
The polarizing plate of the present invention may have a layer formed by polymerizing an ethylenically unsaturated monomer at least one between the polarizer and the first polarizing plate protective layer and between the polarizer and the second polarizing plate protective layer. preferable. Such a layer also serves as an adhesive layer in the present invention. Conventionally, when a polyester polymer layer, a cycloolefin polymer layer or an acrylic polymer layer is used as a protective layer on the liquid crystal cell side, the rework performance during panel mounting tended to deteriorate. Rework performance can be improved by forming, as an adhesion layer, a layer formed by polymerizing an ethylenically unsaturated monomer between the plate protective layer or the second polarizing plate protective layer.

There is no restriction | limiting in particular as an ethylenically unsaturated monomer which can be used for the layer formed by superposing | polymerizing an ethylenically unsaturated monomer. As the ethylenically unsaturated monomer, a monomer having two or more unsaturated double bonds in the same molecule and having no alicyclic structure is preferable.
A monomer having two or more unsaturated double bonds in the same molecule and not having an alicyclic structure has a polymerizable functional group such as a (meth) acryloyl group, a vinyl group, a styryl group, and an allyl group. Examples thereof include (meth) acryloyl group and —C (═O) OCH═CH ₂ . 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, and polyester (meth) acrylates.

  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 And dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, polyester polyacrylate, caprolactone-modified tris (acryloxyethyl) isocyanurate It is done.

  Commercially available polyfunctional acrylate compounds having a (meth) acryloyl group can be used, such as KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd., PET-30, Shin Nakamura Chemical Co., Ltd., NK Ester A -TMMT, A-TMPT, etc. can be mentioned.

  The thickness of the layer formed by polymerizing the ethylenically unsaturated monomer used in the present invention is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 1 to 4 μm.

<Functional layer>
The polarizing plate of the present invention preferably has a functional layer on at least one of the first polarizing plate protective layer, preferably on the surface. Examples of the functional layer include a pattern retardation layer for displaying 3D images, a λ / 4 layer, a hard coat layer, an antireflection layer, an antiglare layer, an antistatic layer, and an optically anisotropic layer. Each functional layer may be used alone or in combination. In particular, in a mode in which a patterned retardation layer or λ / 4 layer is provided on the first polarizing plate protective layer, a hard coat is applied on the other surface of the first polarizing plate protective layer, or on the patterned retardation layer or λ / 4 layer. An embodiment in which a layer is provided is preferred. Further, in the aspect in which the hard coat layer is provided on the pattern retardation layer or λ / 4 layer, the hard coat layer, the pattern retardation layer, or the layer disposed on the visual recognition side of the λ / 4 layer has an ultraviolet absorbing ability. Is preferred.

<Pattern retardation layer>
The optically anisotropic layer described in Japanese Patent No. 4887436 can be used.

  The first polarizing plate protective layer has a first retardation region (hereinafter also simply referred to as a first region) and a second retardation region (hereinafter also simply referred to as a second region) having different birefringence, You may have the optically anisotropic layer (henceforth a pattern phase difference) by which the one phase difference area | region and the 2nd phase difference area | region were alternately patterned for every line. From the viewpoint of use for a 3D stereoscopic image display system, it is preferable that the first region and the second region have a strip shape in which the lengths of the short sides of the first region and the second region are substantially equal and are alternately and repeatedly patterned.

  In the first polarizing plate protective layer, the slow axis of the first region and the slow axis of the second region are substantially orthogonal to each other, so that the polarization of light that has passed through the first region and the second region when displaying 3D images It is preferable from the viewpoint that the state can be changed from linearly polarized light to circularly polarized light, or from circularly polarized light to linearly polarized light, and more preferably orthogonal from the same viewpoint.

  In the case where the first polarizing plate protective layer has a support and a pattern retardation layer, the pattern region is such that the direction of the long side of the pattern and the direction in which the sound speed of the support is maximum are substantially orthogonal. This is preferable from the viewpoint of reducing pixel shift and suppressing crosstalk.

《Retardation》
As described above, the pattern retardation layer having a function of converting from linearly polarized light to circularly polarized light or from circularly polarized light to linearly polarized light preferably has a retardation of ¼ of the wavelength. In general, it is called a quarter-wave plate, and Re = 137.5 nm is an ideal value at a visible light wavelength of 550 nm.
Further, the pattern retardation layer for converting linearly polarized light into circularly polarized light or circularly polarized light into linearly polarized light is not limited to having a retardation of ¼ wavelength. For example, a retardation of -1/4 or 3/4 of the wavelength may be used, and the retardation may be ¼ ± n / 2 (n is an integer) of the wavelength when expressed by a general formula.
Patterning in which the slow axis of the first region and the slow axis of the second region are orthogonal may be performed by alternately forming regions having a retardation of -1/4 or 1/4 of the wavelength. At this time, the slow axes of each region are almost orthogonal. Further, the retardation of 1/4 and 3/4 of the wavelength may be patterned, and the slow axes of the mutual regions at this time are substantially parallel. However, the rotation directions of the circularly polarized light in the respective regions are reversed.
Further, in the patterning of the quarter of the wavelength and the retardation of the quarter, the retardation of 1/2 or −1/2 of the wavelength may be formed after the quarter of the wavelength is formed on the entire surface.
When the first polarizing plate protective layer has a retardation of ¼ of the wavelength, the Re (550) value of the first region included in the optical film and the Re (550) of the second region included in the optical film. 550) The value is preferably from 30 to 250 nm, more preferably from 50 to 230 nm, particularly preferably from 100 to 200 nm, particularly preferably from 105 to 180 nm, and from 115 to 160 nm. Is more preferable, and it is more preferable that it is 130-150 nm.

  Also, from the viewpoint of changing the polarization state of light that has passed through the first region and the second region when displaying 3D images from linearly polarized light to circularly polarized light, or from circularly polarized light to linearly polarized light, the pattern phase difference The total Re (550) of the layer and the support is preferably 110 to 165 nm, more preferably 110 to 155 nm, and still more preferably 120 to 145 nm. In particular, the entire Re (550) of the pattern retardation layer and the support is in the above range, and the slow axes of the first region and the second region are substantially orthogonal to each other, so that the right-eye image and the left-eye can be accurately obtained. It is preferable from the viewpoint that the polarization state of the image for use can be changed.

<Λ / 4 layer>
The 1st polarizing plate protective film used for this invention may have (lambda) / 4 layer which has only the 1st phase difference area | region described in the term of the pattern phase difference layer. In other words, this is not an aspect having two regions having different birefringence but each having a uniform birefringence region. A preferable material and a range of retardation are the same as those of the pattern retardation layer described above.

<Hard coat layer>
The hard coat layer used in the present invention is a layer for imparting hardness and scratch resistance to the film. A hard-coat layer can be formed by apply | coating a coating composition on the 1st polarizing plate protective layer which is a base film, and making it harden | cure, for example. Moreover, you may laminate | stack another functional layer on a hard-coat layer for the purpose of adding another function. Also, by adding fillers and additives to the hard coat layer, chemical performance such as mechanical, electrical and optical physical performance and water / oil repellency can be imparted to the hard coat layer itself. .

  The hard coat layer used in the present invention is preferably excellent in scratch resistance. Specifically, it is preferable to achieve 3H or higher when a pencil hardness test that is an index of scratch resistance is performed.

  The thickness of the hard coat layer used in the present invention is preferably 0.1 to 6 μm, more preferably 3 to 6 μm. By having a thin hard coat layer in the above range, an optical film including a hard coat layer in which physical properties such as brittleness and curl suppression are improved, weight reduction, and manufacturing cost reduction can be obtained. Moreover, pencil hardness can be raised notably by making a base film more than the range of a specific elasticity modulus. For example, the pencil hardness can be remarkably increased by setting the elastic modulus to 2 GPa or more.

  The hard coat layer is preferably formed by curing the curable composition. The curable composition is preferably prepared as a liquid coating composition. An example of the coating composition contains a matrix-forming binder monomer or oligomer, polymers, and an organic solvent. A hard coat layer can be formed by curing the coating composition after coating. For curing, a crosslinking reaction or a polymerization reaction can be used.

The polarizing plate of the present invention, it is preferred that Knoop hardness when the hard coat layer was applied to the first polarizing plate protective layer is 235N / mm ² or more, more preferably 270N / mm ² or more, 270 It is particularly preferred that it is ˜330 N / mm ² .

<Monomer or oligomer for matrix forming binder>
Examples of the monomer or oligomer for matrix forming binder that can be used in the hard coat layer used in the present invention include ionizing radiation curable polyfunctional monomers and polyfunctional oligomers. The polyfunctional monomer or polyfunctional oligomer is preferably a monomer capable of crosslinking reaction or polymerization reaction. The functional group of the ionizing radiation curable polyfunctional monomer or polyfunctional oligomer is preferably a light, electron beam, or radiation polymerizable group, and among them, a photopolymerizable functional group is preferable.

  Examples of the photopolymerizable functional group include unsaturated polymerizable functional groups such as (meth) acryloyl group, vinyl group, styryl group, and allyl group, and ring-opening polymerizable functional groups such as epoxy compounds. Of these, a (meth) acryloyl group is preferred.

As a specific example of a photopolymerizable polyfunctional monomer having a photopolymerizable functional group,
(Meth) acrylic acid diesters of alkylene glycol such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, propylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyoxyalkylene glycols such as triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate;
(Meth) acrylic acid diesters of polyhydric alcohols such as pentaerythritol di (meth) acrylate;
(Meth) acrylic acid diesters of ethylene oxide or propylene oxide adducts such as 2,2-bis {4- (acryloxy-diethoxy) phenyl} propane and 2,2-bis {4- (acryloxy-polypropoxy) phenyl} propane ;
Etc.

  Furthermore, urethane (meth) acrylates, polyester (meth) acrylates, isocyanuric acid acrylates, and epoxy (meth) acrylates are also preferably used as the photopolymerizable polyfunctional monomer.

  Among the above, esters of polyhydric alcohol and (meth) acrylic acid are preferable, and polyfunctional monomers having three or more (meth) acryloyl groups in one molecule are more preferable.

  Specifically, (di) pentaerythritol tri (meth) acrylate, (di) pentaerythritol tetra (meth) acrylate, (di) pentaerythritol penta (meth) acrylate, (di) pentaerythritol hexa (meth) acrylate, tri Pentaerythritol triacrylate, tripentaerythritol hexatriacrylate, trimethylolpropane tri (meth) acrylate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO-modified tri (meth) acrylate phosphate, 1,2,4-cyclohexanetetra (meth) acrylate, Printer glycerol triacrylate, 1,2,3-cyclohexane tetramethacrylate, polyester polyacrylate and caprolactone-modified tris (acryloyloxyethyl) isocyanurate, and the like.

Furthermore, resins having three or more (meth) acryloyl groups, such as relatively low molecular weight polyester resins, polyether resins, acrylic resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins And oligomers or prepolymers such as polyfunctional compounds such as polyhydric alcohols.
As specific compounds of polyfunctional acrylate compounds having three or more (meth) acryloyl groups, reference may be made to [0096] of JP-A No. 2007-256844.

As urethane acrylates, for example, alcohols, polyols, and / or hydroxyl group-containing compounds such as hydroxyl group-containing acrylates are reacted with isocyanates, and if necessary, polyurethane compounds obtained by these reactions (meth) Mention may be made of urethane acrylate compounds obtained by esterification with acrylic acid.
As specific examples of specific compounds, reference can be made to the description of [0017] in JP-A-2007-256844.

  Use of isocyanuric acid acrylates is preferable because curling can be further reduced. Examples thereof include isocyanuric acid diacrylates and isocyanuric acid triacrylates. As examples of specific compounds, reference can be made to [0018] to [0021] of JP-A-2007-256844. .

  In the hard coat layer used in the present invention, an epoxy compound can be further used for reducing shrinkage due to curing. As monomers having an epoxy group for constituting this, monomers having two or more epoxy groups in one molecule are used, and examples thereof include JP-A Nos. 2004-264563, 2004-264564, and Examples thereof include epoxy monomers described in 2005-37737, 2005-37738, 2005-140862, 2005-140862, 2005-140863, 2002-322430 and the like. It is also preferable to use a compound having both epoxy and acrylic functional groups such as glycidyl (meth) acrylate.

《Polymer Compound》
The hard coat layer may contain a polymer compound. The explanation and preferred specific examples of the polymer compound are the same as those described in JP 2012-215812 A, and the contents described in this gazette are incorporated in the present specification.

<< Curable composition >>
Description and preferred specific examples of the curable composition that can be used for forming the hard coat layer are the same as those described in JP 2012-215812 A, and the contents described in this gazette are described in this specification. Incorporated.

<Fingerprint resistant layer, antifouling layer>
In particular, since image display screens having various types of touch panels that have become popular in recent years are required to have fingerprint resistance and antifouling properties, a fingerprint resistant layer or antifouling layer is formed on the first polarizing plate protective layer. It is also useful to do. Regarding the anti-fingerprint layer and the antifouling layer, for example, Japanese Patent No. 4517590, Japanese Patent No. 4638954, International Publication WO2010 / 090116, and International Publication WO2011 / 105594 can be referred to.

Moreover, the layer or film which is a 1st polarizing plate protective layer can also be used as a base material of the transparent conductive film with a hard-coat layer for a touchscreen use.
When the polarizing plate is produced, if the first polarizing plate protective layer has an in-plane slow axis, it can be bonded so that the in-plane slow axis and the transmission axis of the polarizer are parallel or perpendicular to each other. preferable.

<Production method of polarizing plate>
The polarizing plate of the present invention can be produced by a general method. For example, in an embodiment in which the first polarizing plate protective layer is made of a cellulose acylate film (cellulose acylate polymer layer), the back surface of the cellulose acylate film (the surface on which the hard coat layer is not formed), a polarizer, Can be manufactured by bonding. The bonding surface of the cellulose acylate film is preferably subjected to alkali saponification treatment. Moreover, complete saponification type polyvinyl alcohol aqueous solution can be used for bonding.

  As a polarizer, what was manufactured by the conventionally well-known method can be used. For example, a film made of a hydrophilic polymer such as polyvinyl alcohol or ethylene-modified polyvinyl alcohol having an ethylene unit content of 1 to 4 mol%, a polymerization degree of 2000 to 4000, and a saponification degree of 99.0 to 99.99 mol%, A film stretched by treatment with a dichroic dye such as the above, or a film oriented by treating a plastic film such as vinyl chloride is used.

  Moreover, as a method of obtaining a polarizer film of 10 μm or less by stretching and dyeing in the state of a laminated film in which a polyvinyl alcohol layer is formed on a substrate, Patent No. 5048120, Patent No. 5143918, Patent No. 5048120 No. 4, Patent No. 4691205, Patent No. 4751481 and Patent No. 4751486 can be cited, and known techniques relating to these polarizers can also be preferably used for the polarizing plate of the present invention.

  The polarizer thus obtained is bonded to a polarizing plate protective layer.

  The polarizing plate of the present invention is preferably provided adjacent to each other in the order of a polarizer, an adhesive layer, and a first polarizing plate protective layer. Furthermore, it is preferable that the second polarizing plate protective layer, the adhesive layer, the polarizer, the adhesive layer, and the first polarizing plate protective layer are provided adjacent to each other in this order.

[Liquid Crystal Display]
The liquid crystal display device of the present invention has the polarizing plate of the present invention. An example of the arrangement method of the first polarizing plate protective layer is that the first polarizing plate protective layer of the polarizing plate is arranged outside the polarizer without having the hard coat layer (that is, the liquid crystal cell rather than the polarizer of the polarizing plate). The polarizing plate is arranged so as to be far from the polarizing plate. Another example of the arrangement method of the first polarizing plate protective layer is that the first polarizing plate protective layer of the polarizing plate on the display surface side is arranged outside the polarizer in a state having the hard coat layer (that is, the polarizing plate polarizer). The polarizing plate is arranged so as to be farther from the liquid crystal cell. In the liquid crystal display device of the present invention, it is preferable that the polarizing plate is disposed so that the second polarizing plate protective layer of the polarizing plate is closer to the liquid crystal cell than the first polarizing plate protective layer.
As for other configurations, any configuration of a known liquid crystal display device can be adopted. There are no particular restrictions on the mode, and TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-Ferroelectric Liquid Crystal), OCB (Optic STP). It can be configured as a liquid crystal display device in various display modes such as Nematic), VA (Vertically Aligned) and HAN (Hybrid Aligned Nematic).

As the liquid crystal display device of the present invention, a transmissive liquid crystal display device is preferable, and the transmissive liquid crystal display device is usually composed of a backlight, a liquid crystal cell, and two polarizing plates whose transmission axes are orthogonal, The two polarizing plates are bonded to the viewing side and the backlight side of the liquid crystal cell via an adhesive layer.
The liquid crystal cell includes a liquid crystal layer and two glass substrates provided on both sides of the liquid crystal layer.
As the glass substrate for the liquid crystal display device, silicate glass is used, preferably silica glass or borosilicate glass is used, and most preferably non-alkali borosilicate glass is used. If an alkali component is contained in a glass substrate for a liquid crystal display device, the alkali component is eluted and the TFT may be damaged. Here, the alkali-free borosilicate glass is a glass that does not substantially contain an alkali component, and specifically, a glass having an alkali component of 1000 ppm or less. The content of the alkali component in the present invention is preferably 500 ppm or less, more preferably 300 ppm or less of the alkali component.

  The glass substrate for a liquid crystal display device is a plate-like body having a substantially rectangular shape in plan view, and preferably has a plate thickness of 0.01 mm to 1.1 mm. This is because if the thickness is less than 0.01 mm, it is easily affected by light interference or internal distortion due to deformation of the glass substrate for display to be evaluated, and if it is too thick, the luminance at the time of evaluation decreases. A more preferable plate thickness is 0.1 mm to 0.7 mm, and a further preferable plate thickness is 0.1 mm to 0.5 mm. Furthermore, in the present invention, even if the thickness of the glass substrate is 0.1 mm to 0.3 mm, warping can be effectively suppressed.

When the thickness of the liquid crystal cell of the liquid crystal display device is 1100 μm or less (preferably 1000 μm or less), the moisture permeability of the first polarizing plate protective layer of the polarizing plate of the present invention is 12 to 250 g at 40 ° C. and 90% relative humidity. If / m ² / day, warpage of the liquid crystal display device can be more effectively suppressed, and display unevenness can be more effectively suppressed.
When the thickness of the liquid crystal cell of the liquid crystal display device is 700 μm or less (preferably 600 μm or less), the moisture permeability at 90 ° C. relative humidity of the first polarizing plate protective layer of the polarizing plate of the present invention is 12 to 85 g. If / m ² / day, warpage of the liquid crystal display device can be more effectively suppressed, and display unevenness can be more effectively suppressed.
Furthermore, in the liquid crystal display device of the present invention, it is preferable that the moisture permeability of the first polarizing plate protective layer at 40 ° C. and 90% relative humidity is 140 g / m ² / day or less and the thickness of the liquid crystal cell is 1100 μm or less. . Furthermore, in the liquid crystal display device of the present invention, the moisture permeability of the first polarizing plate protective layer at 40 ° C. and 90% relative humidity of 90% is 85 g / m ² / day or less, and the thickness of the liquid crystal cell is 700 μm or less. preferable.
In the above aspect, particularly when the thickness of the polarizer is 5 μm or less, the suppression of display unevenness is more effectively exhibited.

  The features of the present invention will be described more specifically with reference to 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 specific examples shown below.

<Production of films 1 and 2>
Using a pellet of norbornene resin (“ZEONOR1060” manufactured by Nippon Zeon Co., Ltd.) dried at 100 ° C. for 5 hours, a film 1 which is a cycloolefin polymer having a film thickness of 40 μm was obtained by extrusion molding. Moreover, the film 2 with a film thickness of 20 micrometers was obtained by the same method.

<Production of films 3 and 4>
In a reaction vessel having an internal volume of 30 L equipped with a stirrer, a temperature sensor, a cooling pipe and a nitrogen introduction pipe, 41.5 parts of methyl methacrylate (MMA) and 6 parts of methyl 2- (hydroxymethyl) acrylate (MHMA) 2.5 parts of 2- [2′-hydroxy-5′-methacryloyloxy] ethylphenyl] -2H-benzotriazole (trade name: RUVA-93, manufactured by Otsuka Chemical), 50 parts of toluene as a polymerization solvent, 0 0.025 part of an antioxidant (manufactured by Asahi Denka Kogyo Co., Ltd., Adeka Stub 2112) and 0.025 part of n-dodecyl mercaptan were charged as a chain transfer agent, and the temperature was raised to 105 ° C. through nitrogen. When the reflux with the temperature increase started, 0.05 part of t-amyl peroxyisononanoate (manufactured by Arkema Yoshitomi, trade name: Luperox 570) was added as a polymerization initiator, and 0.10 part of t- While amyl peroxy isononanoate was added dropwise over 3 hours, solution polymerization was allowed to proceed under reflux at about 105 to 110 ° C., followed by further aging for 4 hours.

  Next, 0.05 part of 2-ethylhexyl phosphate (manufactured by Sakai Chemical Industry Co., Ltd., Phoslex A-8) is added to the resulting polymerization solution as a catalyst for the cyclization condensation reaction (cyclization catalyst). The cyclization condensation reaction was allowed to proceed for 2 hours under reflux at 0 ° C., and then the polymerization solution was heated for 30 minutes in an autoclave at 240 ° C. to further proceed the cyclization condensation reaction. Next, 0.94 parts of CGL777MPA (manufactured by Ciba Specialty Chemicals) as an ultraviolet absorber was mixed into the polymerization solution after the reaction proceeded.

Next, the obtained polymerization solution was treated with a barrel temperature of 240 ° C., a rotation speed of 100 rpm, a degree of vacuum of 13.3 to 400 hPa, a rear vent number of 1 and a forevent number of 4 (first, second, third, Vent type screw twin screw extruder (Φ = 50.0 mm, L / D = 30) in which a leaf disk type polymer filter (filtration accuracy 5 μ, filtration area 1.5 m ² ) is arranged at the tip. Was introduced at a treatment rate of 45 kg / hr in terms of the amount of resin and devolatilized. At that time, a separately prepared mixed solution of antioxidant / cyclization catalyst deactivator was charged at a rate of 0.68 kg / hour from the back of the first vent, and ion-exchanged water was charged at 0.22 kg / hour. Each was fed from behind the third vent at a speed.

  In the mixed solution of antioxidant / cyclization catalyst deactivator, 50 parts of antioxidant (Sumitizer GS manufactured by Sumitomo Chemical Co., Ltd.) and 35 parts of zinc octylate (manufactured by Nippon Kagaku Sangyo Co., Ltd., Nikka Octix) Zinc (3.6%) was dissolved in 200 parts of toluene.

  Next, after completion of devolatilization, the resin in the hot melt state remaining in the extruder is discharged while being filtered through a polymer filter from the tip of the extruder, pelletized by a pelletizer, and has a lactone ring structure in the main chain A pellet of a transparent resin composition containing an acrylic resin and an ultraviolet absorber was obtained. The weight average molecular weight of the resin was 145000, and the glass transition temperature (Tg) of the resin and the resin composition was 122 ° C.

  A pellet of a transparent resin composition containing an acrylic resin having a lactone ring structure in the main chain and an ultraviolet absorber prepared above was melt-extruded from a coat hanger type T die using a twin screw extruder, and the thickness was about A 40 μm acrylic polymer film was prepared. This film was used as film 3. Further, the film 3 was stretched 1.3 times in length and 1.3 times in width under the temperature condition of 160 ° C. to obtain a film 4 having a thickness of 25 μm.

上記一般式中、Ｒ¹は水素原子、Ｒ²およびＲ³はメチル基であるラクトン環構造を有する（メタ）アクリル系樹脂｛共重合モノマー質量比＝メタクリル酸メチル／２−（ヒドロキシメチル）アクリル酸メチル＝８／２、ラクトン環化率約１００％、ラクトン環構造の含有割合１９．４％、重量平均分子量１３３０００、メルトフローレート６．５ｇ／１０分（２４０℃、１０ｋｇｆ）、Ｔｇ１３１℃｝９０質量部と、アクリロニトリル−スチレン（ＡＳ）樹脂｛トーヨーＡＳ ＡＳ２０、東洋スチレン社製｝１０質量部との混合物（Ｔｇ１２７℃）のペレットを二軸押し出し機に供給し、約２８０℃でシート状に溶融押し出しして、厚さ４０μｍのラクトン環構造を有する（メタ）アクリル系ポリマーのシートを得た。この未延伸シートを１６０℃の温度条件下、縦１．３倍、横１．３倍に延伸して厚さ２５μｍのフィルム５を得た。さらに、フィルム５を１６０℃の温度条件下、縦２．１倍、横２．０倍に延伸して厚さ１０μｍのフィルム６を得た。 <Production of films 5 and 6>

(Meth) acrylic resin having a lactone ring structure in which R ¹ is a hydrogen atom, and R ² and R ³ are methyl groups in the above general formula {copolymerization monomer mass ratio = methyl methacrylate / 2- (hydroxymethyl) acrylic Methyl acid = 8/2, lactone cyclization rate about 100%, lactone ring structure content 19.4%, weight average molecular weight 133000, melt flow rate 6.5 g / 10 min (240 ° C., 10 kgf), Tg 131 ° C.} Pellets of a mixture (Tg 127 ° C.) of 90 parts by mass and 10 parts by mass of acrylonitrile-styrene (AS) resin {Toyo AS AS20, manufactured by Toyo Styrene Co., Ltd.} are supplied to a biaxial extruder and are formed into a sheet at about 280 ° C. By melt extrusion, a (meth) acrylic polymer sheet having a lactone ring structure with a thickness of 40 μm was obtained. This unstretched sheet was stretched 1.3 times in length and 1.3 times in width under a temperature condition of 160 ° C. to obtain a film 5 having a thickness of 25 μm. Further, the film 5 was stretched 2.1 times in length and 2.0 times in width under a temperature condition of 160 ° C. to obtain a film 6 having a thickness of 10 μm.

<Preparation of film 7>

  The imidized resin A was obtained by the method of JP2011-138119 [0173]-[0176]. The imidized resin A is an acrylic resin having a glutarimide structure in the main chain and not having an aromatic vinyl structure.

  About imidized resin A, the imidation ratio, the glass transition temperature, and the acid value were measured according to the following method. As a result, the imidation ratio was 4 mol%, the glass transition temperature was 128 ° C., and the acid value was 0.40 mmol / g.

[Calculation of Imidation Rate] ¹ H-NMR ¹ H-NMR measurement of the resin was performed using BRUKER Avance III (400 MHz). From the area A of the peak derived from the O—CH ₃ proton of methyl methacrylate in the vicinity of 3.5 to 3.8 ppm and the area B of the peak derived from the N—CH ₃ proton of glutarimide in the vicinity of 3.0 to 3.3 ppm, Obtained by the following equation.

Im% = B / (A + B) × 100
Here, the “imidization rate” refers to the ratio of the imide carbonyl group in the total carbonyl group.

  The obtained imidized resin A100 parts by mass was pelletized using a single screw extruder to obtain imidized resin pellets.

  Using the imidized resin pellets, a (meth) acrylic polymer film having a film thickness of 25 μm was obtained in the same manner as the film 5 method. This film was used as film 7.

<Preparation of film 8>
[Synthesis of raw material polyester]
Raw material polyester 1
As shown below, terephthalic acid and ethylene glycol are directly reacted to distill off water, esterify, and then use a direct esterification method in which polycondensation is performed under reduced pressure, and a polyester (Sb catalyst) by a continuous polymerization apparatus. System PET) was obtained.

(1) Esterification reaction In a first esterification reactor, 4.7 tons of high-purity terephthalic acid and 1.8 tons of ethylene glycol are mixed over 90 minutes to form a slurry, and continuously at a flow rate of 3800 kg / h. It supplied to the 1st esterification reaction tank. 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.

(2) the polycondensation reaction above-obtained esterification reaction product supplied to the first polycondensation reaction vessel continuously stirring, the reaction temperature 270 ° C., the reaction vessel pressure 20 torr (2.67 × 10 ^{- 3} MPa) and polycondensation with an average 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 reaction (polycondensation) 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 reaction product (polyethylene terephthalate (PET)) was obtained by reaction (polycondensation) under the following conditions.

  Next, the obtained reaction product was discharged into cold water in a strand form and immediately cut to prepare polyester pellets (cross section: major axis: about 4 mm, minor axis: about 2 mm, length: about 3 mm).

  The obtained polymer is hereinafter abbreviated as PET1.

Raw material polyester 2
10 parts by weight of a dried UV absorber (2,2 ′-(1,4-phenylene) bis (4H-3,1-benzoxazinon-4-one) and 90 parts by weight of PET1 are mixed, and a kneading extruder Was used to obtain a raw material polyester 2 containing an ultraviolet absorber (hereinafter abbreviated as PET2).

[Film forming process]
After 90 parts by mass of the raw material polyester 1 (PET1) and 10 parts by mass of the raw material polyester 2 (PET2) are dried to a water content of 20 ppm or less, they are put into the hopper 1 of a single screw kneading extruder 1 having a diameter of 50 mm. 1 melted to 300 ° C. Extrusion was performed from a die through a gear pump and a filter (pore diameter: 20 μm) under the following extrusion conditions.
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%. Specifically, the back pressure was increased by 1% with respect to the average pressure in the barrel of the extruder, and the piping temperature of the extruder was heated at a temperature 2% higher than the average temperature in the barrel of the extruder.
The molten resin extruded from the die was extruded onto a cooling cast drum set at a temperature of 25 ° C., and was brought into close contact with the cooling cast drum using an electrostatic application method. It peeled using the peeling roll arrange | positioned facing the cooling cast drum, and obtained the unstretched polyester film.

<Horizontal stretching process>
The unstretched polyester film was guided to a tenter (lateral stretching machine), and was stretched laterally by the following method and conditions while holding the end of the film with a clip.

<Preheating part>
The preheating temperature was set to 95 ° C., and the mixture was heated to a temperature at which stretching was possible.

<Extension part>
The preheated unstretched polyester film was horizontally stretched in the width direction under the following conditions.
"conditions"
-Transverse stretching temperature: 95 ° C-Transverse stretching ratio: 4.7 times

<Heat fixing part>
Next, a heat setting treatment was performed while controlling the film surface temperature of the polyester film within the following range.
"conditions"
・ Heat setting temperature: 180 ℃
・ Heat setting time: 15 seconds

<Heat relaxation part>
The polyester film after heat setting was heated to the following temperature to relax the film.
-Thermal relaxation temperature: 170 ° C
-Thermal relaxation rate: TD direction (film width direction) 2%

<Cooling section>
Next, the polyester film after heat relaxation was cooled at a cooling temperature of 50 ° C.

<Recovery of film>
After cooling, both ends of the polyester film were trimmed by 20 cm. Then, after extruding (knurling) at a width of 10 mm at both ends, it was wound up with a tension of 18 kg / m.
Thus, a polyester polymer film 8 having a thickness of 37 μm was obtained.

<Preparation of film 9>
[Preparation of cellulose ester solution for air layer]
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare an air layer cellulose ester solution.

――――――――――――――――――――――――――――――――――
Composition of cellulose ester solution for air layer ――――――――――――――――――――――――――――――――――
-Cellulose ester (acetyl substitution degree 2.86) 100 parts by mass-Sugar ester compound of the formula (RI) 3 parts by mass-Sugar ester compound of the formula (R-II) 1 part by mass-The following UV absorber 2.4 Part by mass / silica particle dispersion (average particle size 16 nm) “AEROSIL R972”,
Made by Nippon Aerosil Co., Ltd. 0.026 parts by mass ・ Methylene chloride 339 parts by mass ・ Methanol 74 parts by mass ・ Butanol 3 parts by mass ―――――――――――――――――――――――― ―――――――――――

Formula (RI)

Formula (R-II)

UV absorber

(Preparation of cellulose ester solution for drum layer)
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose ester solution for a drum layer.

――――――――――――――――――――――――――――――――――
Composition of cellulose ester solution for drum layer ――――――――――――――――――――――――――――――――――
-Cellulose ester (acetyl substitution degree 2.86) 100 parts by mass-Sugar ester compound of the formula (RI) 3 parts by mass-Sugar ester compound of the formula (R-II) 1 part by mass-UV absorber 2.4 parts Part-silica particle dispersion (average particle size 16 nm) "AEROSIL R972",
Made by Nippon Aerosil Co., Ltd. 0.091 parts by mass, 339 parts by weight of methylene chloride, 74 parts by weight of methanol, 3 parts by weight of butanol ――――――――――――――――――――――― ―――――――――――

[Preparation of cellulose ester solution for core layer]
The following composition was put into a mixing tank and stirred while heating to dissolve each component to prepare a cellulose ester solution for the core layer.

――――――――――――――――――――――――――――――――――
Composition of cellulose ester solution for core layer ――――――――――――――――――――――――――――――――――
-Cellulose ester (acetyl substitution degree 2.86) 100 parts by mass-Sugar ester compound of formula (R-II) 8.3 parts by mass-Sugar ester compound of formula (R-II) 2.8 parts by mass-UV absorption Agent 2.4 parts by mass, methylene chloride 266 parts by mass, methanol 58 parts by mass, butanol 2.6 parts by mass ――――――――――――――――――――――――― ――――――――

[Filming by co-casting]
As a casting die, an apparatus equipped with a feed block adjusted for co-casting so that a film having a three-layer structure can be formed was used. The cellulose ester solution for the air layer, the cellulose ester solution for the core layer, and the cellulose ester solution for the drum layer were co-cast on a drum cooled to −7 ° C. from the casting port. At this time, the flow rate of each solution was adjusted so that the thickness ratio would be air layer / core layer / drum layer = 7/90/3.
It casted on the mirror surface stainless steel support body which is a drum of diameter 3m. A dry air of 34 ° C. was applied on the drum at 270 m ³ / min.
The cellulose ester film cast and rotated 50 cm before the end point of the casting part was peeled off from the drum, and then both ends were clipped with a pin tenter. During peeling, 5% stretching was performed in the transport direction (longitudinal direction).

The cellulose ester web held by the pin tenter was conveyed to the drying zone. In the initial drying, a drying air of 45 ° C. was blown and then dried at 110 ° C. for 5 minutes. At this time, the cellulose ester web was conveyed while stretching in the width direction at a magnification of 10%.
After the web was detached from the pin tenter, the portion held by the pin tenter was continuously cut out, and unevenness with a width of 15 mm and a height of 10 μm was made at both ends in the width direction of the web. The width of the web at this time was 1610 mm. It was dried at 140 ° C. for 10 minutes while applying a tensile stress of 210 N in the transport direction. Further, the end in the width direction was continuously cut so that the web had a desired width, and a film 9 having a film thickness of 41 μm was produced. At this time, the film thickness of the width direction edge part cut off after 140 degreeC drying and the web center part was the same.

<Preparation of film 10>
[Preparation of core layer cellulose acylate solution]
The following composition was put into a mixing tank and stirred to dissolve each component to prepare a cellulose acetate solution.
――――――――――――――――――――――――――――――――――
Composition of core layer cellulose acylate solution ――――――――――――――――――――――――――――――――――
-Cellulose acetate with an acetyl substitution degree of 2.88 100 parts by mass-Ester oligomer (Plasticizer 1 below) 10 parts by mass-Polarizer durability improver (Compound A below) 4 parts by mass-Ultraviolet absorber (UV Agent A below) 4 parts by mass, methylene chloride (first solvent) 438 parts by mass, methanol (second solvent) 65 parts by mass ――――――――――――――――――――――――― ――――――――

[Preparation of outer layer cellulose acylate solution]
10 parts by mass of the following matting agent solution was added to 90 parts by mass of the above core layer cellulose acylate solution to prepare an outer layer cellulose acetate solution.
――――――――――――――――――――――――――――――――――
Composition of matting agent solution ―――――――――――――――――――――――――――――――――――
-Silica particles having an average particle size of 20 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) 2 parts by mass-76 parts by mass of methylene chloride (first solvent)-11 parts by mass of methanol (second solvent)-Core layer cellulose acylate solution 1 part by mass ――――――――――――――――――――――――――――――――――

[Preparation of cellulose acylate film]
Three layers of the core layer cellulose acylate solution and the outer layer cellulose acylate solution on both sides of the core layer cellulose acylate solution were cast simultaneously on a drum at 20 ° C. from the casting port. The film was peeled off at a solvent content of about 20% by mass, both ends in the width direction of the film were fixed with tenter clips, and the film was dried while being stretched 1.1 times in the lateral direction with a residual solvent of 3 to 15% by mass. . Then, the film 10 with a film thickness of 25 micrometers was produced by conveying between the rolls of a heat processing apparatus.

<Preparation of film 11>
[Preparation of Cellulose Acylate Solution A-0]
100 parts by mass of cellulose acetate having a degree of acetyl substitution of 2.86 (weight average molecular weight 220,000, hereinafter also referred to as cellulose acetate 1) is dissolved in a mixed solvent of methylene chloride: methanol (mass ratio 80:20) to obtain cellulose acylate. Solution A-0 was obtained.

[Preparation of Acrylic Resin Solution A-1]
PMMA1, which is a polymethyl methacrylate having a weight average molecular weight of 1,500,000, is used as an acrylic resin, dissolved in a mixed solvent of methylene chloride: methanol (mass ratio 80:20), and an acrylic resin solution A-1 (solid content concentration 22%) The complex viscosity was 50 Pa · s).

[Production of optical film]
Using the cellulose acylate solution A-0 prepared above as an outer layer and the acrylic resin solution A-1 prepared above as a core layer, solution casting was performed. Specifically, three layers can be co-casted on a metal support from a die capable of co-casting at the same time, and the outer layer is 10 μm, the core layer is 40 μm, and the outer layer is 10 μm from the metal support surface side. Continuous film formation was performed. While on the metal support, the web was dried with a drying air at 40 ° C. to form a film, and then peeled off. Both ends of the film were fixed with pins, and 5 ° C. with a drying air of 105 ° C. while maintaining the same interval. Dried for minutes. After removing the pin, it was further dried at 130 ° C. for 20 minutes. Then, the film 11 with a film thickness of 10 μm was obtained by peeling off the outer layer.

<Preparation of film 12>
[Preparation of composition B-1 for forming a low moisture-permeable layer]
Each of the following components was mixed, then charged into a glass separable flask equipped with a stirrer, stirred at room temperature for 5 hours, and filtered through a polypropylene depth filter having a pore size of 5 μm to obtain each composition.
――――――――――――――――――――――――――――――――――
Composition of low moisture permeable layer forming composition B-1 ――――――――――――――――――――――――――――――――――
・ Cyclic polyolefin resin TOPAS6013 (Polyplastics Co., Ltd.)
100 parts by mass, cyclohexane 510 parts by mass, cyclohexanone 57 parts by mass ――――――――――――――――――――――――――――――――――

  After applying the low moisture-permeable layer forming composition B-1 on the film 9 using a gravure coater, the film is dried at 25 ° C. for 1 minute, and then dried at 80 ° C. for about 5 minutes to obtain a film thickness of 12 μm. The low moisture-permeable layer laminated film which has a property layer was produced, and the film 12 with a total film thickness of 53 micrometers was obtained.

<Preparation of film 13>
[Preparation of composition B-2 for forming a low moisture-permeable layer]
――――――――――――――――――――――――――――――――――
Composition of low moisture permeable layer forming composition B-2 ――――――――――――――――――――――――――――――――――
-A-DCP (100%) 97.0 parts by mass-Irgacure 127 (100%) 3.0 parts by mass-SP-13 0.04 parts by mass-MEK (methyl ethyl ketone) 81.8 parts by mass ――――――――――――――――――――――――――――

The materials used are shown below.
A-DCP: tricyclodecane dimethanol dimethacrylate [manufactured by Shin-Nakamura Chemical Co., Ltd.]
・ Irgacure 127: Polymerization initiator [Ciba Specialty Chemicals Co., Ltd.]
SP-13: (leveling agent)

On the film 9, the low moisture-permeable layer-forming composition B-2 was applied by a die coating method using the slot die described in Example 1 of JP-A-2006-122889 under the condition of a conveyance speed of 30 m / min. It was dried at 60 ° C. for 150 seconds. Thereafter, using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) with an oxygen concentration of about 0.1% under a nitrogen purge, ultraviolet rays with an illuminance of 400 mW / cm ² and an irradiation amount of 60 mJ / cm ² are irradiated. Then, the coating layer was cured and wound up. The coating amount was adjusted so that the thickness of the low moisture-permeable layer was 6 μm. The obtained low moisture-permeable layer laminated film having a total film thickness of 47 μm was used as the film 13.

<Preparation of film 14>
(1) Preparation of cellulose acylate resin by synthesis Cellulose acylate having an acetyl substitution degree of 2.88 was prepared. Sulfuric acid (7.8 parts by mass with respect to 100 parts by mass of cellulose) was added as a catalyst, and acetic acid was added to carry out an acylation reaction at 40 ° C. Thereafter, the total substitution degree and the 6-position substitution degree were adjusted by adjusting the amount of sulfuric acid catalyst, the amount of water and the aging time. The degree of acetyl substitution of cellulose acylate is determined according to Carbohydr. Res. Was determined by ¹³ C-NMR according to the method described in 273 (1995) 83-91 (Tezuka et al.). The aging temperature was 40 ° C. Further, the low molecular weight component of the cellulose acylate was removed by washing with acetone.

(2) Preparation of Cellulose Acylate Solution A-2 The following composition was put into a mixing tank, stirred to dissolve each component, further heated to 90 ° C. for about 10 minutes, and then filtered with an average pore size of 34 μm and an average pore size. Filtration through a 10 μm sintered metal filter.

――――――――――――――――――――――――――――――――――
Cellulose acylate solution A-2
――――――――――――――――――――――――――――――――――
Cellulose acylate having a degree of acetyl substitution of 2.88 Total 100.0 parts by mass The following plasticizer (polycondensation ester of carboxylic acid and diol) 15 parts by mass Methylene chloride 451.0 parts by mass Methanol 39.0 parts by mass ――――――――――――――――――――――――――――――――――

Polycondensation ester of adipic acid as dicarboxylic acid and ethylene glycol and 1,2-propylene glycol as diol (adipic acid: ethylene glycol: 1,2-propylene glycol = 100: 70: 30 (mass ratio)) ( (Terminal: acetyl group, hydroxyl value: 112 mgKOH / g, molecular weight 1000)

(Preparation of matting agent dispersion)
Next, the following composition containing the cellulose acylate solution A-2 prepared by the above method was put into a disperser to prepare a matting agent dispersion.
―――――――――――――――――――――――――――――――――――
Matting agent dispersion ―――――――――――――――――――――――――――――――――――
-Matting agent (Aerosil R972) 0.2 parts by weight-Methylene chloride 72.4 parts by weight-Methanol 10.8 parts by weight-Cellulose acylate solution A-2 10.3 parts by weight ――――――――――――――――――――――――――

[Preparation of Cellulose Acylate Solution A-3]
A cellulose acylate solution A-3 was prepared by mixing 100 parts by mass of the cellulose acylate solution A-2 and mixing the matting agent dispersion in an amount of 0.20 parts by mass of inorganic fine particles with respect to the cellulose acylate resin. .

(3) Casting The above cellulose acylate solution A-3 was cast using a band casting machine.

(4) Drying The web (film) obtained by casting is peeled off from the band, and then clipped at both ends of the web with a clip and transported at 100 ° C. for 20 minutes in the tenter device. Dried. Thereafter, the web was further transported through a drying zone at a drying temperature of 120 ° C. to dry the web. In addition, the drying temperature here means the film surface temperature of a film.

(5) Winding Then, after cooling to room temperature, each film was wound up, a roll having a roll width of 1340 mm and a roll length of 2600 mm was produced, and a film 14 having a film thickness of 25 μm was obtained.

<Preparation of film 15>
In the production of the film 11, except that the cellulose acylate solution A-0 used for the outer layer was changed to the above-mentioned cellulose acylate solution A-2, the outer layer 10 μm, the core layer 40 μm, A three-layer simultaneous co-cast film having an outer layer of 10 μm was prepared. Then, the film 15 with a film thickness of 10 micrometers was obtained by peeling an outer layer.

<Preparation of coating layer 16>
An optically anisotropic layer was formed on a 75 μm-thick polyethylene terephthalate roll film temporary support using the method described in Example 1 of JP-A-2007-279705. The optical anisotropy and alignment film formed on this temporary support was used as the coating layer 16.

  The coating layer 16 was transferred onto a transparent glass substrate, and when the in-plane retardation value (Re) and the retardation value (Rth) in the film thickness direction were measured at a wavelength of 590 nm, Re = 201 nm and Rth = 98 nm. It was. In addition, Re and Rth are adjusted at 25 ° C. and 60% relative humidity for 24 hours, and then using an automatic birefringence meter (KOBRA-21ADH: manufactured by Oji Scientific Instruments) at 25 ° C. and 60% relative humidity. It was calculated by measuring the phase difference at a wavelength of 590 nm from the direction inclined in increments of 10 ° from + 50 ° to −50 ° from the sample surface normal with the vertical direction and the slow axis as the rotation axis with respect to the sample surface.

<Preparation of coating layer 17>
After each component is mixed as described below, it is charged into a glass separable flask equipped with a stirrer, stirred at room temperature for 5 hours, filtered through a polypropylene depth filter having a pore size of 5 μm, and a composition for forming a cycloolefin polymer layer. Got.

――――――――――――――――――――――――――――――――――
Composition of cycloolefin polymer layer forming composition ――――――――――――――――――――――――――――――――――
・ Zeonor 1020R 100 parts by mass ・ Cyclohexane 510 parts by mass ・ Cyclohexanone 57 parts by mass ――――――――――――――――――――――――――――――――――
ZEONOR 1020R: Cyclic polyolefin resin (manufactured by Nippon Zeon Co., Ltd.)

  A composition for forming a cycloolefin polymer layer is applied on a PET film having a thickness of 100 μm used as a temporary support using a gravure coater, dried at 25 ° C. for 1 minute, and then dried at 80 ° C. for about 5 minutes. A coating layer 17 having a thickness of 5 μm was obtained.

<Production of films 1 to 4 and 8 to 13 with a hard coat layer>
[Production of hard coat layer]
The following hard coat curable composition hard coat 1 was prepared as a coating solution for forming a hard coat layer.

The hard coat 1 is applied onto one surface of each of the films 1 to 4 and 8 to 13 prepared above, and then dried at 100 ° C. for 60 seconds. Irradiation was performed at 1.5 kW and 300 mJ, and a hard coat layer having a thickness of 5 μm was formed. The film thickness was adjusted by using a slot die and adjusting the coating amount in a die coating method. In addition, about the films 1-4, and 8, after carrying out the corona treatment of the surface previously, formation of the hard-coat layer was implemented in the corona treatment surface.
In this way, films 1 to 4 and 8 to 13 with a hard coat layer having a hard coat layer on the films 1 to 4 and 8 to 13 produced as described above were produced.

<Preparation of polarizing plates 1>
<Comparative Example 1>
[Preparation of Polarizing Plate 1]
[Production of polarizer]
A polarizer having a thickness of 30 μm, 10 μm, and 5 μm was prepared by adsorbing iodine to each of the stretched polyvinyl alcohol films having a thickness of 30 μm, 10 μm, and 5 μm.

[Production of polarizing plate using bonding method A]
The surfaces of the film 1 with hard coat layer and the film 5 were subjected to corona treatment. Next, the film 1 and the film 5 are bonded to both sides of the polarizer using a polyvinyl alcohol adhesive so as to sandwich a 10 μm thick polarizer, and dried at 70 ° C. for 10 minutes or more. A polarizing plate 1 was produced. Here, it arrange | positioned so that the transmission axis of a polarizer and the conveyance direction of a film might orthogonally cross.

<Comparative example 2>
[Production of Polarizing Plate 2]
[Preparation of polarizing plate using bonding method B]
<Adhesive for polarizing plate>
A polarizing plate adhesive was prepared by blending 100 parts by mass of 2-hydroxyethyl acrylate, 10 parts by mass of tolylene diisocyanate, and 3 parts by mass of a photopolymerization initiator (Irgacure 127, manufactured by Ciba Specialty Chemicals).

The surfaces of the film 1 with hard coat layer and the film 5 were subjected to corona treatment. Next, on the films 1 and 5, the polarizing plate adhesive was applied to a thickness of 3 μm using a micro gravure coater (gravure roll: # 300, rotational speed 140% / line speed), An optical film with an adhesive was obtained. Subsequently, it bonded together on both surfaces of the polarizer so that a 10-micrometer-thick polarizer might be pinched | interposed with the film 1 with an adhesive agent, and the film 5. FIG. The polarizing plate 2 of the comparative example 2 which has irradiated the ultraviolet-ray from the bonded optical film side (both sides), and has a transparent protective film on both sides of a polarizer was obtained. The line speed was 20 m / min, and the cumulative amount of ultraviolet light was 300 mJ / cm ² . Here, it arrange | positioned so that the transmission axis of a polarizer and the conveyance direction of a film might orthogonally cross.

<Comparative Examples 3 and 4, Examples 1 to 13, 16, 17, 21, 22, Reference Examples 1 to 4>
[Preparation of Polarizing Plates 3-17, 20-25]
As shown in the table below, one film selected from films 1 to 4 and 8 to 13 with a hard coat layer and one film selected from films 5 to 7, 14, and 15 are shown in the table below. The polarizing plates 3-17, 20-25, 29, and 30 were produced by pasting in the combinations described. The polarizing plate was produced by the method described in Examples 1 and 2. That is, it selected from the bonding method A or B as described in the following table | surface, and was used. The polarizer was selected from those having a film thickness of 30 μm, 10 μm, and 5 μm as shown in the following table. The method of laminating the polarizer and the two films was selected from the laminating methods A or B as shown in the following table. Moreover, about the films 1-4, 8 with a hard-coat layer, and the films 5-7, what carried out the corona treatment on the surface before bonding with a polarizer like Example 1 or 2 is used for polarizing plate preparation. did. Moreover, about the films 10 and 12 with a hard-coat layer and the films 14 and 15 which were used for preparation of the polarizing plates 6, 16, and 17, what was saponified by the following method was used for polarizing plate preparation.

[Saponification of film]
Films 9 to 13 with a hard coat layer and films 14 and 15 were prepared, immersed in a 1.5 mol / L NaOH aqueous solution (saponification solution) maintained at 55 ° C. for 2 minutes, washed with water, and then 25 ° C. After being immersed in a 0.05 mol / L aqueous sulfuric acid solution for 30 seconds, the film was neutralized by passing a washing bath under running water for 30 seconds. 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.

<Example 14>
[Preparation of Polarizing Plate 18]
A film 10 with a hard coat layer and a coating layer 16 formed on a temporary support were prepared. Next, on the film 10 and the coating layer 16, the polarizing plate adhesive described in the bonding method B is used in a thickness of 3 μm using a micro gravure coater (gravure roll: # 300, rotational speed 140% / line speed). It was applied to become. Next, after a polarizer having a film thickness of 5 μm was bonded to the film 10 with an adhesive, a coating layer 16 with an adhesive was bonded to the other surface of the polarizer. Then, the polarizing plate 18 of Example 14 was obtained by peeling the temporary support body of the coating layer 16. FIG. Here, it arrange | positioned so that the transmission axis of a polarizer and the conveyance direction of a film might orthogonally cross. In the polarizing plate 18, the in-plane slow axis of the coating layer 16 was orthogonal to the absorption axis of the polarizer.

<Example 15>
[Production of Polarizing Plate 19]
In the production of the polarizing plate 18, the same method was used except that the coating layer 17 formed on the temporary support was used instead of the coating layer 16 formed on the temporary support. Fifteen polarizing plates 19 were produced.
<Example 18>
The surface of the film 4 with a hard coat layer was subjected to corona treatment. Next, the film 4 with a hard coat layer and a polarizer having a film thickness of 5 μm are attached by roll-to-roll using the method of the bonding method A so that the absorption axis of the polarizer and the longitudinal direction of the film are orthogonal to each other. In addition, a polarizing plate with a single-sided protective film was produced.
[Preparation of coating layer 18]
As a coating solution for forming the coating layer 18, the following compound was dissolved in methyl ethyl ketone so as to have a solid content concentration of 35.6%. In addition, the following polymerization initiator 1 is the same as the polymerization initiator 1 used for the hard coat 1 mentioned above.
―――――――――――――――――――――――――――――――――――――――
Composition of coating solution for forming coating layer 18 ―――――――――――――――――――――――――――――――――――――――
Dipentaerythritol hexaacrylate: A-DPH (manufactured by Shin-Nakamura Chemical Co., Ltd.) 48.5 parts by mass pentaerythritol triacrylate: PET30 [manufactured by Nippon Kayaku Co., Ltd.]
48.5 parts by mass Polymerization initiator 1 3.0 parts by mass Adhesion improving agent: 2.0 parts by mass of the following compound B ―――――――――――――――――――――――― ―――――――――――――――

The above coating solution is applied to the surface on the polarizer side of the polarizing plate with a single-side protective film, then dried at 70 ° C. for 60 seconds, and irradiated with UV at 150 mJ / cm ² under the condition of 0.1% or less of nitrogen. And cured to form a coating layer 18 having a thickness of 4 μm. The film thickness was adjusted by using a slot die and adjusting the coating amount in a die coating method. Thus, the polarizing plate 26 was produced.

（化合物２）

（化合物３）

（化合物４）

（化合物５）

<Example 19>
In the same manner as in Example 18, a polarizing plate with a single-sided protective film was produced.
[Preparation of coating layer 19-A])
As a coating solution for forming the coating layer 19-A, the following compound was dissolved in methyl ethyl ketone so as to have a solid content concentration of 35.6%.
The following compound was dissolved in methyl ethyl ketone to prepare a solid concentration of 35%.
――――――――――――――――――――――――――――――――――
Composition of coating solution for forming coating layer 19-A ――――――――――――――――――――――――――――――――――
Polymerizable liquid crystalline compound 1 86.7 parts by mass Compound 2 8.6 parts by mass Polymerization initiator: Compound 3 9 parts by mass Polymerization initiator: Compound 4 1.0 part by mass Fluorine-containing surfactant: Compound 5 0.8 parts by mass Part adhesion improver: 1.0 parts by mass of Compound A ――――――――――――――――――――――――――――――――――
(Compound 1)

(Compound 2)

(Compound 3)

(Compound 4)

(Compound 5)

The coating liquid was applied and dried on the polarizer side surface of the polarizing plate with a single-side protective film prepared above. The discotic liquid crystalline compound was aligned by heating at 70 ° C. for 1 minute. Thereafter, an ultraviolet ray of 500 mJ / cm ² was immediately irradiated under a temperature condition of 70 ° C. to polymerize the discotic liquid crystalline compound, and the alignment state was fixed. The thickness of the formed optical compensation layer was 1.0 μm. The thickness of the optical compensation layer was measured with a laser film thickness meter. Thus, the coating layer 19-A was produced on the polarizing plate.

[Measurement of optical properties]
The coating layer 19-A was formed on a glass substrate under the same conditions as in the example, and the retardation of only the optical compensation layer was measured. The in-plane retardation (Re (550)) was 0.3 nm and the retardation in the film thickness direction (Rth (550)) was 100 nm. The refractive index was 1.58.

(Preparation of coating layer 19-B)
As a temporary support for the coating layer 19-B, a commercially available cellulose acylate film “TD80UL” (manufactured by FUJIFILM Corporation) was prepared. Subsequently, a rubbing alignment film coating solution having the following composition was continuously applied to one side of the prepared film with a # 8 wire bar. The alignment film was formed by drying with warm air of 60 ° C. for 60 seconds and further with warm air of 100 ° C. for 120 seconds. Thereafter, the film was rubbed once in one direction at 500 rpm in the longitudinal direction of the film to produce a transparent support with a rubbing alignment film. The alignment film had a thickness of 0.5 μm.
――――――――――――――――――――――――――――――――――
Composition of coating solution for alignment film formation ――――――――――――――――――――――――――――――――――
3.9 parts by mass of polymer material for alignment film (PVA103, Kuraray Co., Ltd. polyvinyl alcohol)
Methanol 36 parts by mass Water 60 parts by mass ――――――――――――――――――――――――――――――――――

<Preparation of vertically aligned liquid crystal layer>
The following coating liquid for optically anisotropic layer was applied at a coating amount of 4 ml / m ² using a bar coater. Next, after heating and aging at a film surface temperature of 110 ° C. for 2 minutes, it was cooled to 80 ° C., and using an air-cooled metal halide lamp (made by Eye Graphics Co., Ltd.) of 20 mW / cm ² under the condition of 0.1% or less of nitrogen. The coating layer 19-B was formed on the temporary support by irradiating with ultraviolet rays for 20 seconds to fix the alignment state. The slow axis direction of the coating layer 19-B was perpendicularly aligned with the discotic liquid crystal perpendicular to the film longitudinal direction. The film thickness of the coating layer 19-B was 1.1 μm.

――――――――――――――――――――――――――――――――――
Composition of coating solution for optically anisotropic layer ――――――――――――――――――――――――――――――――――
Discotic liquid crystal E-1 100 parts by mass alignment film interface alignment agent (II-1) 3.0 parts by mass air interface alignment agent (P-1) 0.4 parts by mass photopolymerization initiator 3.0 parts by mass (Irgacure 127 , Manufactured by Ciba Specialty Chemicals Co., Ltd.)
Methyl ethyl ketone 400 parts by mass ――――――――――――――――――――――――――――――――――

[Measurement of optical properties]
The coating layer 19-B was formed on a glass substrate under the same conditions as in the example, and the retardation of only the optical compensation layer was measured. The in-plane retardation (Re (550)) was 155 nm, and the retardation in the film thickness direction (Rth (550)) was −75 nm. The refractive index was 1.58.

(Preparation of polarizing plate 27)
A micro gravure coater (gravure roll: # 300, rotational speed 140% / line speed) is applied to the adhesive for polarizing plate described in the bonding method B on the coating layer 19-A formed on the polarizing plate. It was used and coated to a thickness of 0.5 μm. Subsequently, after preparing the coating layer 19-B formed on the temporary support body and bonding the coating layer 19-A and the coating layer 19-B together, the temporary support body of the coating layer 19-B. The polarizing plate 27 was obtained by peeling off. Here, it arrange | positioned so that the transmission axis of a polarizer and the conveyance direction of a film might orthogonally cross. In the polarizing plate 27, the in-plane slow axis of the coating layer 19-B was orthogonal to the absorption axis of the polarizer.

<Example 20>
A polarizing plate 28 was produced by applying the coating layer 18 on both surfaces of a 5 μm-thick polarizer in the same manner as the polarizing plate 26 (shown as “application” in Table 2 described later).

<Example 23>
The surface of the film 5 was subjected to corona treatment. Next, the film 5 and a polarizer having a thickness of 10 μm are bonded to each other by roll-to-roll using the method of the bonding method A so that the absorption axis of the polarizer and the longitudinal direction of the film are orthogonal to each other. A polarizing plate with a film was prepared.
(Preparation of coating layer 20)
As a coating solution for forming the coating layer 20-A, the following compound was dissolved in a solvent in which methyl ethyl ketone and methyl acetate were mixed in the same weight to prepare a solid concentration of 55%. In addition, the following polymerization initiator 1 is the same as the polymerization initiator 1 used for the hard coat 1 mentioned above.
――――――――――――――――――――――――――――――――――――――――
Composition of coating solution for forming coating layer 20-A ―――――――――――――――――――――――――――――――――――――― -
Tricyclodecane dimethanol diacrylate: A-DCP (manufactured by Shin-Nakamura Chemical Co., Ltd.) 77 parts by mass Pine Crystal KR-120 (manufactured by Arakawa Chemical Industries, Ltd.) 20 parts by mass Polymerization initiator 1 3.0 parts by mass
Adhesion improver: Compound A 2.5 parts by mass ――――――――――――――――――――――――――――――――――――――― -

  Subsequently, as a coating solution for forming the coating layer 20-B, APEL 8008: a copolymer of tetracyclododecene and ethylene (manufactured by Mitsui Chemicals) is dissolved in cyclohexane so that the solid content concentration becomes 10%. Prepared.

  The coating solution for forming the coating layer 20-A was applied to the surface on the polarizer side of the polarizing plate with a single-side protective film, and then dried at 40 ° C. for 30 seconds. In this way, a coating layer 20-A having a thickness of 1 μm was formed. Subsequently, a coating solution for forming the coating layer 20-B is applied on the coating layer 20-A, dried at 60 ° C. for 120 seconds, and then UV is 1.5 kW under the condition of 0.1% or less of nitrogen. The coating layer 20 was irradiated with 300 mJ and cured to form a coating layer 20 having a total thickness of 13 μm of the coating layer 20 -A and the coating layer 20 -B. The film thickness was adjusted by using a slot die and adjusting the coating amount in a die coating method. In this way, a polarizing plate 31 was produced.

<Example 24>
In the production of the polarizing plate 31, a polarizing plate 32 was produced in the same manner as the polarizing plate 31, except that a polarizing film having a thickness of 5 μm was used instead of the polarizing film having a thickness of 10 μm.

<Example 25>
In the production of the polarizing plate 31, a polarizing plate 33 was produced in the same manner as the polarizing plate 31, except that a polarizer having a thickness of 10 μm was used instead of the polarizing plate with a single-side protective film having the film 5 on one side. .

<Example 26>
In the production of the polarizing plate 32, a polarizing plate 34 was produced in the same manner as the polarizing plate 32 except that a polarizer having a thickness of 5 μm was used instead of the polarizing plate with a single-side protective film having the film 5 on one side. .

<Evaluation>
[Evaluation of moisture permeability (moisture permeability at 40 ° C., 90% relative humidity)]
The measurement method of the moisture permeability of the first polarizing plate protective layer is “Polymer Physical Properties II” (Polymer Experiment Course 4 Kyoritsu Shuppan), pages 285 to 294: Measurement of vapor permeation (mass method, thermometer method, Vapor pressure method, adsorption amount method) were applied.
Sample 70mmφ was conditioned at 40 ° C and relative humidity 90% for 24 hours respectively, and using a moisture permeable cup according to the method of JIS Z-0208, moisture permeability = mass after humidity control-mass before humidity control per unit area The amount of water (g / m ² ) was calculated. In addition, in this measurement, the mass change in the said conditions was measured with the blank cup which did not put the hygroscopic agent, and the moisture permeability value was correct | amended. The results are shown in Table 2 below.

[Evaluation of heat resistance of polarizing plate]
About the polarizing plate of each Example, the comparative example, and the reference example which were produced above, orthogonal transmittance CT of the polarizer in wavelength 550nm was measured using UV3150 (made by Shimadzu Corp.). The average value of 10 measurements was used as the measurement value.
The polarizing plate heat resistance test was performed as follows. First, a polarizing plate conditioned for 240 hours in an environment of 25 ° C. and a relative humidity of 60% was prepared. Next, two samples (about 5 cm × 5 cm) in which a polarizing plate is attached to glass with an adhesive so that the film with a hard coat layer is on the outside are prepared, and the absorption axes of the two samples are orthogonal to each other. The transmittance was measured in the bonded state. This transmittance was defined as the orthogonal transmittance of the polarizing plate before the heat resistance test.
After that, after storage for 100 hours at 100 ° C. in a DRY environment (in a state where humidity is not controlled, and in this example, comparative examples and reference examples, relative humidity is 0% to 15%) The orthogonal transmittance after the property test was measured. The change in orthogonal transmittance before and after aging was determined, and the polarizer heat resistance was evaluated according to the following criteria. The results are shown in Table 2 below.
Here, the change amount of the orthogonal transmittance is calculated by the following equation.
Change in orthogonal transmittance (%) = {(Orthogonal transmittance after heat resistance test (%) − Orthogonal transmittance before heat resistance test (%)
A: Change in orthogonal transmittance is less than 0.06% B: Change in orthogonal transmittance is 0.06% or more and less than 0.08% C: Change in orthogonal transmittance is 0.08% or more

[Evaluation of display unevenness]
(1) Mounting on liquid crystal display device The polarizing plates on both sides were peeled off from the liquid crystal cell of a commercially available liquid crystal television (IPS mode slim type 42 type liquid crystal display device, Δnd = 320 nm), and used as the liquid crystal cell A. The thickness of the glass used for the liquid crystal cell A was about 500 μm, and the thickness of the liquid crystal cell was about 1000 μm.
Further, the polarizing plates on both sides were peeled off from a liquid crystal cell of Apple iPad (IPS mode liquid crystal display device, Δnd = 350 nm), and used as a liquid crystal cell B. The thickness of the glass used for the liquid crystal cell B was about 300 μm, and the thickness of the liquid crystal cell was about 600 μm.
Further, the polarizing plates on both sides were peeled off from the liquid crystal cell of W32-H9000 (IPS mode liquid crystal display device, Δnd = 320 nm) manufactured by Hitachi, and used as the liquid crystal cell C. The thickness of the glass used for the liquid crystal cell C was about 700 μm, and the thickness of the liquid crystal cell was about 1400 μm.
Using the three types of liquid crystal cells A to C, the produced polarizing plate was re-bonded to the liquid crystal cell via an adhesive as shown in the table below. Here, except for Example 14 & Example 19 in the following table, two sheets of the same polarizing plate bonded to the front and back of the liquid crystal cell were used for evaluation. In Example 14 of the following table, the polarizing plate 18 was used as the viewing side polarizing plate, the polarizing plate 19 was used as the light source side polarizing plate, and the liquid crystal cell was used for evaluation. In Example 19 shown in the following table, a polarizing plate 27 for the viewing side polarizing plate, a polarizing plate 26 for the light source side polarizing plate, and the front and back surfaces of the liquid crystal cell were used for evaluation.

(2) Evaluation of display unevenness After holding for 72 hours in an environment of 50 ° C. and 85% relative humidity, the backlight of the liquid crystal display device is turned on after being left for 2 hours in an environment of 25 ° C. and 60% relative humidity. 10 hours later, light leakage at the four corners of the panel was evaluated to evaluate display unevenness.
Light leakage evaluation for display unevenness is performed by photographing a black display screen from the front of the screen with a luminance measurement camera “ProMetric” (Radian Imaging), and the difference in luminance between the average luminance of the entire screen and the portion where light leakage at four corners is large. Based on the above, the following criteria were used for evaluation. The results are shown in Table 2 below.
A: The light leakage at the four corners of the panel is not visually recognized (light leakage from the panel is about the same as before the thermo-injection).
B: Of the four corners of the panel, slight light leakage is visible at one corner, but is acceptable.
C: Out of the four corners of the panel, light leakage is visually recognized at 2 to 4 corners, which is unacceptable.
D: Clear light leakage is visually recognized at least one of the four corners of the panel, and is not acceptable.
E: Light leakage at the four corners of the panel is strongly recognized and is not acceptable.

As is clear from the above table, it was found that the polarizing plate of the present invention was excellent in heat resistance (Examples 1 to 26). In particular, when the moisture permeability of the protective layer was 12 to 250 g / m ² / day, the warpage of the liquid crystal panel was more effectively improved when the protective layer was placed in a high temperature and high humidity environment and then returned to room temperature. Further, when the moisture permeability of the protective layer was 12 to 85 g / m ² / day, the warpage of the liquid crystal panel was significantly effectively improved when the protective layer was placed in a high temperature and high humidity environment and then returned to room temperature. In particular, when the thickness of the polarizer is 5 μm or less, the tendency is remarkable.
On the other hand, when the moisture permeability of the protective layer was less than 12 g / m ² / day, it was found that the heat resistance of the polarizing plate was inferior (Comparative Examples 1 to 4).
On the other hand, the thickness of the polarizer is the case of 30 [mu] m, even the moisture permeability as less than 12g / m ² / day, even moisture permeability as above 12g / m ² / day, the difference in heat resistance was observed.

Claims (15)

At least one first polarizing plate protective layer and a polarizer, wherein the polarizer has a thickness of 10 μm or less, and the first polarizing plate protective layer transmits light at 40 ° C. and a relative humidity of 90%. A polarizing plate having a humidity of 12 g / m ² / day or more.   The polarizing plate according to claim 1, further comprising at least one second polarizing plate protective layer on the opposite side of the polarizer from the first polarizing plate protective layer.   The polarizing plate according to claim 2, wherein the thickness of the second polarizing plate protective layer is 25 μm or less.   It has a layer formed by polymerizing an ethylenically unsaturated monomer in at least one between the polarizer and the first polarizing plate protective layer and between the polarizer and the second polarizing plate protective layer. 3. The polarizing plate according to 3.   The polarizing plate of Claim 4 whose thickness of the layer formed by superposing | polymerizing the said ethylenically unsaturated monomer is 5 micrometers or less.   The first polarizing plate protective layer and / or the second polarizing plate protective layer includes a layer selected from a cellulose acylate polymer layer, a polyester polymer layer, an acrylic polymer layer, and a cycloolefin polymer layer. The polarizing plate of any one of Claims 2-5.   The polarizing plate according to claim 2, wherein the first polarizing plate protective layer and / or the second polarizing plate protective layer includes a layer containing a liquid crystal compound.   The polarizing plate of any one of Claims 1-7 whose thickness of the said polarizing plate is 95 micrometers or less.   The polarizing plate of any one of Claims 1-8 whose thickness of a said 1st polarizing plate protective layer is 60 micrometers or less.   The polarizing plate according to claim 1, wherein the first polarizing plate protective layer is a layer having ultraviolet absorbing ability.   The polarizing plate of any one of Claims 1-10 which has a hard-coat layer on a said 1st polarizing plate protective layer.   A liquid crystal display device comprising a liquid crystal cell and at least one polarizing plate according to claim 1.   The liquid crystal display device according to claim 12, wherein the first polarizing plate protective layer is disposed on a side opposite to the liquid crystal cell with respect to the polarizer. 14. The liquid crystal display device according to claim 13, wherein the first polarizing plate protective layer has a moisture permeability of 40 g / m ² / day or less at 40 ° C. and 90% relative humidity, and a liquid crystal cell thickness of 1100 μm or less. 14. The liquid crystal display device according to claim 13, wherein the first polarizing plate protective layer has a water vapor transmission rate of 85 g / m ² / day or less at 40 ° C. and 90% relative humidity, and a liquid crystal cell thickness of 700 μm or less.