JP2014157284A - Polarizing plate protective film, polarizing plate and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate protective film which has low moisture permeability, exhibits excellent adhesiveness to a polarizer when assembled in a polarizer, and can sufficiently reduce a panel warpage amount when assembled in a liquid crystal display device, after the panel is left in a high-temperature and high-humidity environment.SOLUTION: The polarizing plate protective film includes at least one surface layer essentially comprising cellulose acylate and a core layer essentially comprising a polymer excluding cellulose acylate. In the film, the total film thickness of the surface layer is 0.2 to 10 μm; the polymer as the main component of the core layer is a cycloolefin resin or a styrene-acryl copolymer; and the polymer as the main component of the core layer shows a solution viscosity of 10 Pa s to 100 Pa s when the polymer is dissolved in a dichloromethane/methanol mixture solvent (in a mass ratio of 95/5) to obtain a concentration of 18 mass%.

Description

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

In recent years, liquid crystal display devices have been widely used for liquid crystal panels such as liquid crystal televisions, personal computers, mobile phones, and digital cameras. Usually, a liquid crystal display device has a liquid crystal panel member provided with polarizing plates on both sides of a liquid crystal cell, and display is performed by controlling light from the backlight member with the liquid crystal panel member. Here, the polarizing plate is composed of a polarizer and protective films on both sides thereof, and a general polarizer is obtained by dyeing a stretched polyvinyl alcohol (PVA) film with iodine or a dichroic dye to protect it. A cellulose ester film or the like is used as the film.
In liquid crystal display devices, it is known to use a polymer film as an optical compensation film (retardation film) in order to increase the viewing angle, improve image coloring, and improve contrast. For polymer films used as optical compensation films, depending on the liquid crystal cell mode of the liquid crystal display device such as VA mode or IPS mode, the optical properties of the film (for example, retardation value Re and film thickness in the film plane) It is required to provide desired optical anisotropy by controlling the birefringence such as the retardation value Rth in the vertical direction.

  Recent liquid crystal display devices are becoming more and more demanding, and the demands for durability are becoming stricter as the quality of the liquid crystal display devices increases. As an example of durability, stability for environmental changes is required for use in outdoor applications, and optical films such as the polarizing plate protective film and optical compensation film used in liquid crystal display devices are also resistant to changes in temperature and humidity. It is required to suppress changes in dimensions and optical characteristics. Problems with liquid crystal display devices exposed to high temperature and high humidity conditions include the occurrence of warping and display unevenness in the liquid crystal cell of the liquid crystal display device. This is because moisture penetrates into the polarizing plate and the optical film constituting it. Desorption causes a difference in the shrinkage balance between the front and back polarizing plates of the liquid crystal cell of the liquid crystal display device, causing the liquid crystal cell to warp, and the four corners and four sides of the liquid crystal cell come into contact with the casing and the back side members. This is considered to be caused by uneven display. For this reason, improvement of humidity dependency and wet heat durability has been demanded for protective films and optical compensation films for polarizing plates. It is necessary to suppress desorption, and in particular, the optical film on the outermost surface of the polarizing plate is required to have a performance that prevents moisture from passing through, that is, a reduction in moisture permeability.

  Patent Document 1 discloses a laminate having a core layer containing a polymer soluble or dispersible in an organic solvent or water, and a surface layer mainly composed of a cellulose derivative having a thickness of 0.1 to 20 μm on at least one side of the core layer. It is described that by using a film as a protective film for a polarizing plate, a polarizing plate having low retardation, no foreign matter defects, and excellent dimensional stability under high temperature and high humidity can be produced.

  Patent Document 2 has an acrylic resin layer containing an acrylic resin and a cellulose acylate layer containing a cellulose acylate provided on at least one layer on the surface of the acrylic resin layer, and used as a main component in the acrylic resin layer. The optical film having an acrylic resin weight average molecular weight of 600,000 to 4,000,000 is less likely to cause display unevenness when other members in the liquid crystal display are in contact with the cellulose acylate film, and bonded to a polarizer. It is described that the film is easy and the film surface is good.

JP 2001-215331 A JP 2012-093714 A

Liquid crystal display devices are used not only in conventional indoor applications but also in harsher environments such as outdoors, and for the optical film on the outermost surface of the liquid crystal display device, it is important to have a performance that does not transmit moisture. . This problem is due to the tendency of thinning of the glass of liquid crystal cells in TV applications, which are becoming larger in recent years. In recent years, it has become increasingly important. When the present inventors examined the optical film containing the high molecular weight acrylic resin in the core layer of patent document 2, it did not fully reach the low-moisture permeability level demanded in recent years, and the liquid crystal display device It was found that there was a problem of panel warping after aging in a high temperature and high humidity environment.
On the other hand, if polystyrene or the like is used as the polymer for the core layer, or if a polymer having a low molecular weight and a low solution viscosity is used, there is room for improvement in terms of polarizing plate adhesion and polarizer adhesion. This was found by the inventors' investigation.

  In view of the situation as described above, the problems to be solved by the present invention are low moisture permeability, excellent polarizer adhesion when incorporated in a polarizing plate, and high temperature and high temperature of a panel when incorporated in a liquid crystal display device. An object of the present invention is to provide a polarizing plate protective film that can sufficiently reduce the amount of panel warpage after aging in a wet environment.

The present inventors have intensively studied to solve the above-mentioned problems. By using a coalescence and disposing a surface layer with a specific film thickness containing cellulose acylate on the core layer, the moisture permeability is lower, the adhesiveness to the polarizer is better, and the film is incorporated into the liquid crystal display device At that time, it was found that a polarizing plate protective film capable of sufficiently reducing the amount of warpage of the panel after aging in a high temperature and high humidity environment was obtained, and the present invention was achieved.
The present invention, which is a specific means for solving the above problems, has the following configuration.

（一般式（１）中、Ｒはそれぞれ独立に、水素原子、脂肪族炭化水素基またはアリール基を表し、Ｒは互いに同一であっても異なっていてもよい。）

（一般式（２）中、Ｒ¹、Ｒ³およびＲ⁵は水素原子、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。）
［３］ ［２］に記載の偏光板保護フィルムは、前記一般式（１）で表される化合物が、Ｒとして少なくとも１つのフェニル基を有する化合物、２以上のＲが互いに結合して複素環を形成した化合物またはノボラック型フェノール樹脂であることが好ましい。
［４］ ［２］または［３］に記載の偏光板保護フィルムは、前記コア層の主成分となるポリマーがスチレンとアクリルの共重合体であり、
前記一般式（１）で表される化合物を前記コア層の主成分となるポリマーに対して５〜５０質量％含み、
前記一般式（１）で表される化合物がノボラック型フェノール樹脂であることが好ましい。
［５］ ［１］〜［４］のいずれか一に記載の偏光板保護フィルムは、前記スチレンとアクリルの共重合体が、スチレン／アクリルの重合比が重量比で２／８〜８／２のスチレンとアクリルの共重合体であることが好ましい。
［６］ ［２］または［３］に記載の偏光板保護フィルムは、前記コア層の主成分となるポリマーがシクロオレフィン樹脂であり、
前記一般式（１）で表される化合物、前記一般式（２）で表される化合物または芳香族炭化水素ホルムアルデヒド樹脂を前記コア層の主成分となるポリマーに対して５〜５０質量％含み、
前記一般式（１）で表される化合物がＲとして少なくとも１つのフェニル基を有する化合物または２以上のＲが互いに結合して複素環を形成した化合物であることが好ましい。
［７］ ［１］〜［６］のいずれかに記載の偏光板保護フィルムは、前記偏光板保護フィルムの透湿度が１０５ｇ／ｍ²／ｄａｙ以下（膜厚４０μｍ換算）であることが好ましい。
［８］ ［１］〜［７］のいずれかに記載の偏光板保護フィルムは、前記コア層の両表面に、それぞれ前記表層を有することが好ましい。
［９］ ［１］〜［８］のいずれかに記載の偏光板保護フィルムは、前記コア層の膜厚が、２０〜６０μｍであることが好ましい。
［１０］ 偏光子と、少なくとも１枚の［１］〜［９］のいずれかに記載の偏光板保護フィルムとを有することを特徴とする偏光板。
［１１］ ［１０］に記載の偏光板は、前記偏光子の一方の表面上のみに、前記偏光板保護フィルムを有することが好ましい。
［１２］ 液晶セルと、該液晶セルの少なくとも一方に配置された［１０］または［１１］に記載の偏光板とを有し、前記偏光板保護フィルムが最表層となるように配置されたことを特徴とする液晶表示装置。
［１３］ 支持体上に、少なくとも１層のセルロースアシレートを主成分とする表層用ドープと、セルロースアシレート以外のポリマーを主成分とするコア層用ドープとを流延し、フィルムを形成する工程と、前記フィルムを剥ぎ取る工程を含み、前記表層の合計膜厚が、０．２〜１０μｍであり、前記コア層用ドープの主成分となるポリマーが、シクロオレフィン樹脂、またはスチレンとアクリルの共重合体のいずれかであり、前記コア層用ドープの主成分となるポリマーが、ジクロロメタン／メタノール混合溶媒（質量比９５／５）に対して１８質量％の濃度で溶解したときの溶液粘度が、１０Ｐａ・ｓ〜１００Ｐａ・ｓとなるポリマーであることを特徴とする偏光板保護フィルムの製造方法。 [1] A surface layer mainly composed of at least one cellulose acylate, and a core layer mainly composed of a polymer other than cellulose acylate,
The total film thickness of the surface layer is 0.2 to 10 μm,
The polymer that is the main component of the core layer is either a cycloolefin resin or a copolymer of styrene and acrylic,
A polymer whose solution viscosity is 10 Pa · s to 100 Pa · s when the polymer as the main component of the core layer is dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5). A polarizing plate protective film, wherein
[2] The polarizing plate protective film according to [1] is a compound represented by the following general formula (1), the following general formula (2), and one hydrogen bond donating property in the core layer. It is preferable that 5-50 mass% of at least 1 sort (s) of compounds which have a group or aromatic hydrocarbon formaldehyde resin is included with respect to the polymer used as the main component of the said core layer.

(In general formula (1), each R independently represents a hydrogen atom, an aliphatic hydrocarbon group or an aryl group, and R may be the same or different from each other.)

(In the general formula ^{(2), R 1, R} 3 and R ⁵ are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group, or a carbon number of 2 to 20 carbon atoms Represents an aromatic group of 6 to 20.)
[3] In the polarizing plate protective film according to [2], the compound represented by the general formula (1) is a compound having at least one phenyl group as R, and two or more Rs are bonded to each other to form a heterocyclic ring. It is preferable that the compound is a novolak type phenolic resin or a compound which forms
[4] In the polarizing plate protective film according to [2] or [3], the polymer as a main component of the core layer is a copolymer of styrene and acrylic,
Containing 5 to 50% by mass of the compound represented by the general formula (1) with respect to the polymer as the main component of the core layer,
It is preferable that the compound represented by the general formula (1) is a novolac type phenol resin.
[5] In the polarizing plate protective film according to any one of [1] to [4], the styrene / acrylic copolymer has a styrene / acrylic polymerization ratio of 2/8 to 8/2 by weight. Of these, a copolymer of styrene and acrylic is preferred.
[6] In the polarizing plate protective film according to [2] or [3], the polymer that is a main component of the core layer is a cycloolefin resin,
The compound represented by the general formula (1), the compound represented by the general formula (2) or the aromatic hydrocarbon formaldehyde resin is contained in an amount of 5 to 50% by mass with respect to the polymer as the main component of the core layer,
The compound represented by the general formula (1) is preferably a compound having at least one phenyl group as R or a compound in which two or more Rs are bonded to each other to form a heterocyclic ring.
[7] The polarizing plate protective film according to any one of [1] to [6] preferably has a moisture permeability of 105 g / m ² / day or less (converted to a film thickness of 40 μm).
[8] The polarizing plate protective film according to any one of [1] to [7] preferably has the surface layer on both surfaces of the core layer.
[9] In the polarizing plate protective film according to any one of [1] to [8], the thickness of the core layer is preferably 20 to 60 μm.
[10] A polarizing plate comprising a polarizer and at least one polarizing plate protective film according to any one of [1] to [9].
[11] The polarizing plate according to [10] preferably has the polarizing plate protective film only on one surface of the polarizer.
[12] A liquid crystal cell and the polarizing plate according to [10] or [11] disposed in at least one of the liquid crystal cells, wherein the polarizing plate protective film is disposed as an outermost layer A liquid crystal display device.
[13] A film is formed by casting a dope for a surface layer mainly composed of at least one cellulose acylate and a dope for a core layer mainly composed of a polymer other than cellulose acylate on a support. A step and a step of peeling off the film, wherein the total film thickness of the surface layer is 0.2 to 10 μm, and the polymer that is the main component of the core layer dope is a cycloolefin resin or styrene and acrylic The viscosity of the solution when the polymer, which is one of the copolymers and is the main component of the core layer dope, is dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5). The manufacturing method of the polarizing plate protective film characterized by being a polymer used as 10 Pa.s-100 Pa.s.

  The polarizing plate according to the present invention has low moisture permeability, excellent polarizer adhesion when incorporated in a polarizing plate, and can sufficiently reduce the amount of warping of the panel after aging in a high temperature and high humidity environment when incorporated in a liquid crystal display device. A protective film can be provided. By using the polarizing plate protective film of the present invention, it is possible to provide a liquid crystal display device in which the amount of panel warpage after aging in a high temperature and high humidity environment is suppressed.

It is another cross-sectional schematic of the polarizing plate protective film of this invention.

Below, the polarizing plate of this invention, its manufacturing method, the additive used for it, etc. are demonstrated in detail.
The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
“Acrylic resin” means a resin obtained by polymerizing methacrylic acid or a derivative of acrylic acid, and a resin containing the derivative. Further, when not particularly limited, “(meth) acrylate” represents acrylate and methacrylate, and “(meth) acryl” represents acryl and methacryl.

[Polarizing plate protective film]
The polarizing plate protective film of the present invention (hereinafter also referred to as the film of the present invention) includes at least one surface layer mainly composed of cellulose acylate and a core layer mainly composed of a polymer other than cellulose acylate. The total thickness of the surface layer is 0.2 to 10 μm, and the polymer that is the main component of the core layer is either a cycloolefin resin or a copolymer of styrene and acrylic, The polymer whose main component is a polymer having a solution viscosity of 10 Pa · s to 100 Pa · s when dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5). Features. The surface layer “having cellulose acylate as a main component” means that the proportion of cellulose acylate in all polymers contained in the surface layer is 50% by mass or more. The phrase “the core layer is mainly composed of a polymer other than cellulose acylate” means that the proportion of the polymer other than cellulose acylate in the total polymer contained in the core layer is 50% by mass or more. The “polymer that is the main component of the core layer” means a polymer that occupies 50% by mass or more of the total polymer contained in the core layer.
With the above configuration, the moisture permeability is low, the polarizer has excellent adhesiveness when incorporated in a polarizing plate, and the amount of panel warpage after aging of the panel at a high temperature and high humidity environment when incorporated in a liquid crystal display device can be sufficiently reduced.

<Film structure and properties>
The polarizing plate protective film of the present invention includes a surface layer mainly composed of at least one cellulose acylate and a core layer mainly composed of a polymer other than cellulose acylate, and the total film thickness of the surface layer is 0. .2 to 10 μm.
FIG. 1 is a schematic view showing a partial cross-sectional structure in an example of the polarizing plate protective film 10 of the present invention. As shown in FIG. 1, the first surface layer 1 (surface layer on the support surface side) and the second surface layer 3 (surface layer on the air surface side) are the outer surfaces of the polarizing plate protective film 10. Located in. That is, the first surface layer 1 and the second surface layer 3 are located on the opposite surfaces in the polarizing plate protective film 10. The core layer 2 is located between the first surface layer 1 and the second surface layer 3 and inside the polarizing plate protective film 10.
The polarizing plate protective film of the present invention preferably has a three-layer structure composed of a first surface layer, a core layer, and a second surface layer, but has a structure of four or more layers including other functional layers. May be. When the polarizing plate protective film includes other functional layers, for example, the surface of the polarizing plate protective film opposite to the core layer of the first surface layer, the core layer of the second surface layer Functional layers can be provided on the opposite side, between the first surface layer and the core layer, and between the second surface layer and the core layer.
When the polarizing plate protective film has a three-layer structure including the first surface layer, the core layer, and the second surface layer, the first surface layer, the core layer, and the second surface layer are sequentially stacked adjacent to each other. Structure. When the polarizing plate protective film is attached to the polarizer, either the first surface layer or the second surface layer may be laminated on the polarizer side.
In this invention, it is preferable that resin which comprises a 1st surface layer and a 2nd surface layer is the same resin. In the present invention, the additive contained in the first surface layer and the second surface layer is more preferably the same additive, and the content ratio of the resin and the additive in the first surface layer and the second surface layer. Are also particularly preferred. Thereby, since the physical property of the 1st surface layer and the 2nd surface layer can be made equivalent and the restriction | limiting of the surface laminated | stacked on the polarizer side is lose | eliminated, the assembly operation | work of a polarizing plate can be made easy.

The total film thickness of the surface layer is preferably 1 to 9 μm, and more preferably 4 to 8 μm.
The thickness of the surface layer is preferably 0.1 to 5 μm, more preferably 0.5 to 4.5 μm, and particularly preferably 2 to 4 μm per layer.
The thickness of the core layer is preferably 20 to 60 μm, more preferably 30 to 60 μm, and particularly preferably 25 to 40 μm.
Moreover, 100 micrometers or less are preferable and, as for the film thickness of the whole polarizing plate protective film of this invention, 60 micrometers or less are more preferable.
In the film of the present invention, the ratio of the total film thickness of the surface layer to the total film thickness is preferably 40% or less, more preferably 1 to 30%, and more preferably 5 to 20%. It is particularly preferred. However, the total film thickness of a surface layer here means the total film thickness of two layers, when there are two surface layers. By satisfying this relationship, the surface condition during casting tends to be better. Furthermore, the interfacial adhesion, curlability, water absorption reduction, etc. of the obtained polarizing plate protective film can be preferably adjusted.

(Film width)
The film of the present invention preferably has a film width of 400 to 2500 mm, more preferably 1000 mm or more, particularly preferably 1500 mm or more, and particularly preferably 1800 mm or more.

(Water permeability of film)
The moisture permeability of the film is measured under the conditions of 40 ° C. and 90% relative humidity based on JIS Z-0208.
The moisture permeability was determined by subtracting a measured value of moisture permeability using an aluminum foil having a thickness of 10 μm from each sample instead of the measured value of each sample, and performing zero point correction to obtain the moisture permeability of the sample. Further, the moisture permeability decreases as the film thickness increases, and increases as the film thickness decreases. Therefore, it is necessary to convert the samples having different film thicknesses by setting the reference to 40 μm. The film thickness can be converted according to the following mathematical formula.
Mathematical formula: moisture permeability in terms of 40 μm = measured moisture permeability × measured film thickness (μm) / 40 (μm).
The moisture permeability of the polarizing plate protective film of the present invention is preferably 105 g / m ² / day or less, more preferably 80 g / m ² / day, and more preferably 70 g / m ² / day or less. More preferably, it is still more preferably 60 g / m ² / day or less. When the water vapor transmission rate is 105 g / m ² / day or less, warpage of the liquid crystal cell and display unevenness during black display after the normal temperature, high humidity, and high temperature and high humidity environment of the liquid crystal display device can be suppressed.

<Core layer>
The film of the present invention includes a core layer containing a polymer other than cellulose acylate as a main component, and the polymer as the main component of the core layer is either a cycloolefin resin or a copolymer of styrene and acrylic. The solution viscosity when the polymer as the main component of the core layer is dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5) is 10 Pa · s to 100 Pa · s. It is a polymer.
Here, the solution viscosity (synonymous with the complex viscosity of the dope) in the present invention is a sample solution prepared by dissolving the target sample at a concentration of 18% by mass with respect to a mixed solution of dichloromethane / methanol = 95/5 mass ratio. Is the viscosity measured at a frequency of 1 Hz and 25 ° C. using a solution shear rheometer (CLS500) and a Steel Cone (both manufactured by TA Instruments) with a diameter of 4 cm. The sample solution is a measurement result obtained by starting measurement after holding the sample solution at a measurement start temperature until the liquid temperature becomes constant.

The polymer which is the main component of the core layer is a polymer having a solution viscosity of 20 to 90 Pa · s when dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5). It is preferable that the polymer is 25 to 70 Pa · s, and it is particularly preferable that the polymer is 30 to 60 Pa · s.
The solution viscosity can be adjusted by the molecular weight of the polymer. For example, when a cycloolefin resin is used, in order to obtain a solution viscosity of 10 Pa · s to 100 Pa · s when dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5). The weight average molecular weight of the olefin resin is preferably 200000 to 4000000, more preferably 400000 to 3000000, and particularly preferably 600000 to 2000000.
When a copolymer of styrene and acrylic is used, the solution viscosity when dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5) is 10 Pa · s to 100 Pa · s. Therefore, the number average molecular weight of the copolymer of styrene and acrylic is preferably 600000 to 4000000, more preferably 800000 to 3000000, and particularly preferably 100000 to 1800000.
The weight average molecular weight can be measured by a usual method using GPC (Gel Permeation Chromatography), and polystyrene can be used as a standard material.
In addition, it is preferable from a viewpoint of improving a water vapor transmission rate that a polymer of the said core layer does not contain a cellulose acylate.

(Cycloolefin resin)
A cycloolefin resin can be used as the polymer that is the main component of the core layer. Here, the cycloolefin resin represents a polymer resin having a cycloolefin structure.
Examples of the polymer resin having a cycloolefin structure used in the present invention include (1) a norbornene polymer, (2) a monocyclic cycloolefin polymer, (3) a cyclic conjugated diene polymer, (4) There are vinyl alicyclic hydrocarbon polymers and hydrides of (1) to (4).
The preferred polymer for the present invention is an addition (co) polymer cycloolefin resin containing at least one repeating unit represented by the following general formula (II) and, if necessary, a repeating unit represented by the general formula (I) An addition (co) polymer cycloolefin resin further comprising at least one of the above. Further, a ring-opening (co) polymer containing at least one cyclic repeating unit represented by the general formula (III) can also be suitably used.

In formulas (I) to (III), 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.

X ¹ to X ^3, Y by ¹ introducing a polarizable large functional group in a substituent to Y ^3, by increasing the thickness direction retardation (Rth) of the polarizing plate protective film, in-plane retardation (Re ) Can be increased. A film having a high Re developability can increase the Re value by stretching in the film forming process.

このノルボルネン系樹脂は、ＪＳＲ（株）からアートン（Ａｒｔｏｎ）ＧあるいはアートンＦ（アートンＦ５０２３など）という商品名で発売されており、また日本ゼオン（株）からゼオノア（Ｚｅｏｎｏｒ）ＺＦ１４、ＺＦ１６、ゼオネックス（Ｚｅｏｎｅｘ）２５０あるいはゼオネックス２８０という商品名で市販されており、これらを使用することができる。 Norbornene-based polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19807, JP-A-2003-159767, or JP-A-2004-309979. 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 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.
Furthermore, the cycloolefin resin preferably has a structural unit represented by the following general formula.

This norbornene-based resin is sold under the trade name of Arton G or Arton F (Arton F5023, etc.) by JSR Co., Ltd., and ZEONOR ZF14, ZF16, ZEONEX (Zeonor Corporation). Zeonex) 250 or ZEONEX 280 are commercially available, and these 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 cycloolefin resin is not limited, but a high Tg cycloolefin resin such as 200 to 400 ° C. can also be used.

(Styrene and acrylic copolymer)
As a polymer that is a main component of the core layer, a copolymer of styrene and acrylic can be used. The styrene / acrylic copolymer has a repeating structural unit derived from styrene and a repeating structural unit derived from acrylic.

  In addition, the acryl in the repeating structural unit derived from acryl means (meth) acryl, and is a concept including both methacryl and acryl. The repeating structural unit derived from (meth) acryl also includes a combination of a repeating structural unit derived from acrylate / a repeating structural unit derived from methacrylate, particularly a combination of a repeating structural unit derived from acrylate ester / a repeating structural unit derived from methacrylate ester. It is.

  The repeating structural unit derived from acrylic preferably has a repeating structural unit derived from a (meth) acrylate monomer as the repeating structural unit.

  The copolymer of styrene and acrylic further polymerizes 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 a repeating structural unit constructed by

Formula (201)
CH ₂ = C (X) R ²⁰¹

(In General Formula (201), 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. Represents a —CO—R ²⁰³ group, and R ²⁰² and R ²⁰³ represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms.)

The (meth) acrylic acid ester is not particularly limited, and examples thereof include methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, cyclohexyl acrylate, and benzyl acrylate. Acrylic acid esters; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, methacrylic acid esters such as benzyl methacrylate; These 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 the (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 weight, more preferably 10%, in order to sufficiently exhibit the effects of the present invention. -100% by weight, more preferably 40-100% by weight, particularly preferably 50-100% by weight.

The hydroxyl group-containing monomer is not particularly limited. For example, 2- (hydroxyalkyl) acrylic acid ester such as α-hydroxymethylstyrene, α-hydroxyethylstyrene, methyl 2- (hydroxyethyl) acrylate; 2 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 the hydroxyl group-containing monomer, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by weight, more preferably 0 to 0% in order to sufficiently exert the effects of the present invention. It is 20% by weight, more preferably 0 to 15% by weight, particularly preferably 0 to 10% by weight.

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. You may use together. Among these, acrylic acid and methacrylic acid are preferable in that the effects of the present invention are sufficiently exhibited.
When the unsaturated carboxylic acid is used, the content ratio in the monomer component to be subjected to the polymerization step is preferably 0 to 30% by weight, more preferably 0 to 20%, in order to sufficiently exhibit the effects of the present invention. % By weight, more preferably 0-15% by weight, particularly preferably 0-10% by weight.

Examples of the monomer represented by the general formula (201) include styrene, vinyl toluene, α-methyl styrene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, vinyl acetate, and the like. You may use, and may use 2 or more types together. 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% in order to sufficiently exhibit the effects of the present invention. %, More preferably 0 to 20% by weight, still more preferably 0 to 15% by weight, particularly preferably 0 to 10% by weight.

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.
As a polymerization reaction form for polymerizing the monomer component to obtain a polymer having a hydroxyl group and an ester group in the molecular chain, a polymerization form using a solvent is preferable, and solution polymerization is particularly preferable. .
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.

  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 styrene / acrylic copolymer preferably contains a repeating unit based on an unsaturated carboxylic acid alkyl ester. As the repeating unit based on the unsaturated carboxylic acid alkyl ester, for example, those represented by the following general formula (102) are preferable.
Formula _{(102): - [CH 2} -C (R 41) (COOR 42)] -

In General Formula (102), R ⁴¹ represents hydrogen or an alkyl group having 1 to 5 carbon atoms, R ⁴² represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms, or one or more carbon atoms. Represents an aliphatic or alicyclic hydrocarbon group having 1 to 6 carbon atoms substituted with several hydroxyl groups or halogen.

The monomer corresponding to the repeating unit represented by the general formula (102) is represented by the following general formula (103).
Formula _{(103): CH 2 = C} (R 41) (COOR 42)

  Preferred examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, (meth) acrylic acid. t-butyl, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (meth ) 3-hydroxypropyl acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate and 2,3,4,5-tetrahydroxypentyl (meth) acrylate, among others, methacryl Methyl acid is most preferably used. These may be used individually by 1 type, or may use 2 or more types together.

  The content of the unsaturated carboxylic acid alkyl ester unit in the styrene / acrylic copolymer is preferably 50 to 95% by mass, more preferably 55 to 90% by mass.

As an unsaturated carboxylic acid unit, what is represented, for example by the following general formula (104) is preferable.
Formula _{(104): - [CH 2} -C (R 51) (COOH)] -
Here, R ⁵¹ represents hydrogen or an alkyl group having 1 to 5 carbon atoms.

Preferable specific examples of the monomer for deriving the unsaturated carboxylic acid unit include a compound represented by the following general formula (105) which is a monomer corresponding to the repeating unit represented by the general formula (104), and Examples thereof include maleic acid and a hydrolyzate of maleic anhydride, and acrylic acid and methacrylic acid are preferable, and methacrylic acid is more preferable in terms of excellent thermal stability.
Formula _{(105): CH 2 = C} (R 51) (COOH)

  These may be used individually by 1 type, or may use 2 or more types together. As described above, an acrylic thermoplastic copolymer having a glutaric anhydride unit and an unsaturated carboxylic acid alkyl ester-based unit is, for example, a copolymer having an unsaturated carboxylic acid alkyl ester-based unit and an unsaturated carboxylic acid unit. Since the polymer can be obtained by cyclization of the polymer, it may have an unsaturated carboxylic acid unit in its constituent unit.

  As content of the unsaturated carboxylic acid unit with respect to said styrene and acrylic copolymer, 10 mass% or less is preferable, More preferably, it is 5 mass% or less. By setting the content to 10% by mass or less, it is possible to prevent a decrease in colorless transparency and retention stability.

As the repeating structural unit derived from styrene, unsubstituted styrene, (p-, m- or o-methylstyrene), (2,4-, 2,5-, 3,4- or 3,5-dimethylstyrene) , Poly (alkylstyrene) such as (p-tertiarybutylstyrene), (p-, m- or o-chlorostyrene), poly (p-, m- or o-bromostyrene), (p-, m- Or (o-fluorostyrene), (halogenated styrene) such as (o-methyl-p-fluorostyrene), (halogen-substituted alkylstyrene) such as (p-, m- or o-chloromethylstyrene), (p- , M- or o-methoxystyrene), (alkoxystyrene) such as (p-, m- or o-ethoxystyrene), and (carboxya) such as (p-, m- or o-carboxymethylstyrene). Kirusuchiren) (p-vinylbenzyl propyl ether) such as (alkyl ether styrene), (p-trimethylsilyl styrene) such as (alkyl silyl styrene), more like (vinylbenzyl dimethoxyphosphoryl sulfide).
In the present invention, unsubstituted styrene is particularly preferable among the repeating structural units derived from styrene. Moreover, the repeating structural unit derived from styrene used in the present invention is not necessarily a single compound, and may be a mixture with a repeating structural unit derived from other styrene, a copolymer, or a mixture thereof. For controlling physical properties, vinyl toluene, α-methyl styrene, acrylonitrile, methyl vinyl ketone, ethylene, propylene, vinyl acetate, maleic anhydride and the like may be copolymerized.

  In addition, the styrene / acrylic copolymer may have other vinyl monomer units that do not contain an aromatic ring as long as the effects of the present invention are not impaired. Specific examples of other vinyl monomer units that do not contain an aromatic ring include the corresponding monomers: vinyl cyanide monomers such as acrylonitrile, methacrylonitrile, ethacrylonitrile; allyl glycidyl ether Maleic anhydride, itaconic anhydride; N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, acrylamide, methacrylamide, N-methylacrylamide, butoxymethylacrylamide, N-propylmethacrylamide; aminoethyl acrylate, acrylic Propylaminoethyl acid, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, cyclohexylaminoethyl methacrylate; N-vinyldiethylamine, N-acetylvinylamine, allylamine, methallylamino , N- methyl-allyl amine; 2-isopropenyl - oxazoline, 2-vinyl - oxazoline, 2-acryloyl - oxazoline, and the like. These may be used alone or in combination of two or more.

  As content of the other vinyl-type monomer unit which does not contain an aromatic ring with respect to said styrene and an acrylic copolymer, 35 mass% or less is preferable.

The copolymer of styrene and acrylic used in the present invention is preferably a copolymer of unsubstituted styrene and unsubstituted (meth) acrylic acid ester, and is substituted with unsubstituted styrene and unsubstituted (meth) acrylic acid. A copolymer of methyl is more preferable, and a copolymer of unsubstituted styrene and unsubstituted methyl methacrylate is particularly preferable.
The styrene / acrylic copolymer used in the present invention is a styrene / acrylic copolymer having a styrene / acrylic polymerization ratio of 2/8 to 8/2 by weight, thereby obtaining a film with lower moisture permeability. It is preferable that the copolymer is a styrene / acrylic copolymer of 3/7 to 5/5.

  The weight average molecular weight Mw of the copolymer of styrene and acrylic used in the present invention is preferably 80,000 or more. When the weight average molecular weight Mw of the copolymer of styrene and acrylic is 80,000 or more, the mechanical strength is high and the handling property at the time of film production is excellent. From this viewpoint, the weight average molecular weight Mw of the copolymer of styrene and acrylic is preferably 100,000 or more. Further, from the viewpoint of improving compatibility with cellulose acylate, the weight average molecular weight Mw of the copolymer of styrene and acrylic is preferably 3000000 or less, and more preferably 2000000 or less.

  As the copolymer of styrene and acrylic used in the present invention, a commercially available product can also be used. Two or more styrene / acrylic copolymers may be used in combination.

<Surface>
The polarizing plate protective film of this invention contains the surface layer which has an at least 1 layer of cellulose acylate as a main component, and the total film thickness of the said surface layer is 0.2-10 micrometers.
The polarizing plate protective film of the present invention preferably has the surface layer on both surfaces of the core layer.

(Types of cellulose acylate)
Examples of cellulose used as a raw material for the cellulose acylate for the surface layer include cotton linter and wood pulp (hardwood pulp, conifer pulp). May be used. Detailed descriptions of these raw material celluloses can be found, for example, by Marusawa and Uda, “Plastic Materials Course (17) Fibrous Resin”, published by Nikkan Kogyo Shimbun (published in 1970), and the Japan Institute of Invention and Technology Publication No. 2001. The cellulose described in No.-1745 (pages 7 to 8) can be used.

(Degree of acyl substitution of cellulose acylate)
The cellulose acylate used for the surface layer preferably has a total substitution degree of acyl groups of 1.2 or more and 3.0 or less.
Furthermore, the cellulose acylate used for the surface layer has a total substitution degree of acyl groups of TA, a substitution degree of acyl groups having 2 carbon atoms, TA2, and a substitution degree of acyl groups of 3 to 7 carbon atoms. When TA3 is satisfied, the following conditions are preferably satisfied. By setting it as the following range, the polarizing plate protective film excellent in the viewpoint of adhesiveness with an adjacent layer, drum peelability, and curl reduction of a film can be obtained.
2.2 ≦ TA total ≦ 3.0
1.5 ≦ TA2 ≦ 3.0
0.0 ≦ TA3 ≦ 0.7

The cellulose acylate is more preferably a cellulose acylate that satisfies the following conditions.
2.5 ≦ TA total ≦ 3.0
2.4 ≦ TA2 ≦ 3.0
0.0 ≦ TA3 ≦ 0.1

  The cellulose acylate used for the surface layer is preferably at least one selected from cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate benzoate, cellulose propionate, and cellulose butyrate. Among these, more preferred cellulose acylates are cellulose acetate and cellulose acetate propionate, and more preferred is triacetyl cellulose.

  In addition, the substitution degree of an acetyl group and the substitution degree of other acyl groups can be obtained by a method prescribed in ASTM-D817-96.

(Weight average molecular weight of cellulose acylate)
The weight average molecular weight (Mw) of the cellulose acylate used for the surface layer is preferably 50,000 to 500,000 from the viewpoint of improving the film surface shape, more preferably 80000 to 400,000, and 100,000 to 300,000. Is particularly preferred.

  The weight average molecular weight of the cellulose acylate used for the surface layer is more preferably in the range of 75,000 to 300,000, and more preferably in the range of 100,000 to 240,000, particularly from the viewpoint of adhesion with the core layer. Those having a molecular weight of 160000 to 240,000 are particularly preferable. If the weight average molecular weight (Mw) of the cellulose acylate is 75,000 or more, the effect of improving the self-film forming property and adhesion of the surface layer itself is preferable. In the present invention, two or more kinds of cellulose acylates can be mixed and used.

<Additives>
The polarizing plate protective film of the present invention may contain an additive in each of the core layer and the surface layer, together with a polymer as a main material.

（一般式（１）中、Ｒはそれぞれ独立に、水素原子、脂肪族炭化水素基またはアリール基を表し、Ｒは互いに同一であっても異なっていてもよい。）

（一般式（２）中、Ｒ¹、Ｒ³およびＲ⁵は水素原子、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。） <Moisture permeability reducing compound>
The polarizing plate protective film of the present invention is a compound represented by the following general formula (1) in the core layer in order to reduce moisture permeation and desorption.
A compound represented by the following general formula (2) and having one hydrogen-bonding donating group, or an aromatic hydrocarbon formaldehyde resin:
Among these, it is preferable that 5-50 mass% of at least 1 type compound is included with respect to the polymer used as the main component of the said core layer.

(In general formula (1), each R independently represents a hydrogen atom, an aliphatic hydrocarbon group or an aryl group, and R may be the same or different from each other.)

(In the general formula ^{(2), R 1, R} 3 and R ⁵ are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group, or a carbon number of 2 to 20 carbon atoms Represents an aromatic group of 6 to 20.)

The moisture permeability reducing compound preferably has a structure containing one or more aromatic rings. Hydrophobic properties can be imparted to the film by the aromatic ring, and moisture permeation and desorption can be suppressed.
More preferably, the moisture permeability reducing compound has a structure containing two or more aromatic rings.
The moisture permeability reducing compound preferably includes one or more —OH groups, more preferably includes two or more aromatic rings, and more preferably includes one or more —OH groups.

(Compound represented by the general formula (1))
In the compound represented by the general formula (1), at least one of R preferably represents an aliphatic hydrocarbon group or an aryl group.
In addition, when R represents an aliphatic hydrocarbon group or an aryl group, the aliphatic hydrocarbon group or aryl group may further have a substituent, and examples of the substituent include an aliphatic hydrocarbon group, an aryl group And a hydroxyl group.
Two or more Rs may be bonded to each other to form a ring, and examples of the ring formed include a saturated hydrocarbon ring, an aromatic ring, and a heterocyclic ring.
The aliphatic hydrocarbon group represented by R is preferably an alkyl group.
The aryl group represented by R is preferably a phenyl group.

  The compound represented by the general formula (1) includes (i) a compound having at least one phenyl group as R, (ii) a compound in which two or more R's are bonded to each other to form a heterocyclic ring, or (iii) It is preferably a phenolic resin.

(I) Compound having at least one phenyl group as R Among the compounds represented by the general formula (1), the compound having at least one phenyl group as R has a structure including one or more aromatic rings. It is more preferable that the structure has three or more aromatic rings, and a compound represented by the following general formula (B) is preferable.
General formula (B)

In the general formula ^{(B), R 12, R} 13, R 14, R 15, R 16, R 21, R 23, R 24, R 25, R 32, R 33, R 34, R 35, R 36 are, Each represents a hydrogen atom or a substituent, and the substituent T described below can be applied as the substituent. Moreover, the general formula in ^{(B) R 12, R 13} , R 14, R 15, R 16, R 21, R 23, R 24, R 25, R 32, R 33, R 34, R 35 and R ³⁶ At least one of them is an amino group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, a hydroxy group, a mercapto group, or a carboxyl group.

Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, and particularly preferably 1 to 8 carbon atoms, such as a methyl group, an ethyl group, an isopropyl group, and tert-butyl. Group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, etc.), alkenyl group (preferably having 2 to 20 carbon atoms, more preferably 2 carbon atoms). To 12, particularly preferably 2 to 8 carbon atoms, such as vinyl group, allyl group, 2-butenyl group, and 3-pentenyl group), alkynyl group (preferably 2 to 20 carbon atoms, more preferably Has 2 to 12 carbon atoms, particularly preferably 2 to 8 carbon atoms, and examples thereof include a propargyl group and a 3-pentynyl group.), Aryl (Preferably having 6 to 30 carbon atoms, more preferably 6 to 20 carbon atoms, particularly preferably 6 to 12 carbon atoms, and examples thereof include a phenyl group, a p-methylphenyl group, and a naphthyl group.), An amino group (Preferably has 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, and particularly preferably 0 to 6 carbon atoms. For example, amino group, methylamino group, dimethylamino group, diethylamino group, dibenzylamino group, etc. And an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, and a butoxy group. ), An aryloxy group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as phenyl A xy group, a 2-naphthyloxy group, etc.), an acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as an acetyl group, A benzoyl group, a formyl group, a pivaloyl group, etc.), an alkoxycarbonyl group (preferably having a carbon number of 2 to 20, more preferably a carbon number of 2 to 16, particularly preferably a carbon number of 2 to 12, such as methoxycarbonyl Group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, particularly preferably having 7 to 10 carbon atoms, such as a phenyloxycarbonyl group. An acyloxy group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, especially Preferably it is C2-C10, for example, an acetoxy group, a benzoyloxy group, etc. are mentioned. ), An acylamino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include an acetylamino group and a benzoylamino group), alkoxycarbonyl. An amino group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, particularly preferably 2 to 12 carbon atoms, such as a methoxycarbonylamino group), an aryloxycarbonylamino group (preferably Has 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, particularly preferably 7 to 12 carbon atoms, such as a phenyloxycarbonylamino group, and a sulfonylamino group (preferably 1 to 1 carbon atom). 20, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms. Nylamino group, benzenesulfonylamino group, etc.), sulfamoyl group (preferably having 0 to 20 carbon atoms, more preferably 0 to 16 carbon atoms, particularly preferably 0 to 12 carbon atoms, such as sulfamoyl group, methyl A sulfamoyl group, a dimethylsulfamoyl group, a phenylsulfamoyl group, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to carbon atoms). 12 and examples thereof include a carbamoyl group, a methylcarbamoyl group, a diethylcarbamoyl group, a phenylcarbamoyl group, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably carbon atoms). Examples thereof include methylthio group and ethylthio group. ), An arylthio group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, particularly preferably 6 to 12 carbon atoms, such as a phenylthio group), a sulfonyl group (preferably C1-C20, More preferably, it is C1-C16, Most preferably, it is C1-C12, For example, a mesyl group, a tosyl group, etc. are mentioned), a sulfinyl group (preferably C1-C20, More preferably, it is C1-C16, Most preferably, it is C1-C12, for example, a methanesulfinyl group, a benzenesulfinyl group, etc.), a ureido group (preferably C1-C20, more preferably carbon) The number is 1 to 16, particularly preferably 1 to 12, and examples thereof include a ureido group, a methylureido group, and a phenylureido group. ), A phosphoric acid amide group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, and particularly preferably 1 to 12 carbon atoms, such as a diethylphosphoric acid amide group and a phenylphosphoric acid amide group. Hydroxy group, mercapto group, halogen atom (eg fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfino group, hydrazino group, imino group Group, heterocyclic group (preferably having 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, and examples of the hetero atom include a nitrogen atom, an oxygen atom, and a sulfur atom, specifically, for example, an imidazolyl group, a pyridyl group, and a quinolyl group. Group, furyl group, piperidyl group, morpholino group, benzoxazolyl group, benzimidazolyl group, benzthiazolyl group, etc. ), A silyl group (preferably having 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, particularly preferably 3 to 24 carbon atoms, and examples thereof include a trimethylsilyl group and a triphenylsilyl group. For example). Among these, an alkyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, and an aryloxy group are more preferable, and an alkyl group, an aryl group, and an alkoxy group are more preferable.
These substituents may be further substituted with a substituent T. Moreover, when there are two or more substituents, they may be the same or different. If possible, they may be linked together to form a ring.

Further, in the general formula ^{(B), R 12, R} 13, R 14, R 15, R 16, R 21, R 23, R 24, R 25, R 32, R 33, R 34, R 35, R 36 At least one of them is an amino group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, a hydroxy group, a mercapto group, or a carboxyl group, more preferably an amino group or a hydroxy group. A hydroxy group is preferred. These groups may be substituted with a substituent. As the substituent in this case, the above-described substituent T can be applied, and the preferred range is also the same.

  Preferred examples of the compound represented by formula (B) of the present invention are shown below, but the present invention is not limited to these specific examples.

（一般式（１’）中、Ｒはそれぞれ独立に、水素原子、脂肪族炭化水素基またはアリール基を表し、Ｒは互いに同一であっても異なっていてもよい。Ｒ’は脂肪族炭化水素基を表す。）
一般式（１’）中におけるＲは、それぞれ独立に、脂肪族炭化水素基であることが好ましく、炭素数１〜３のアルキル基であることがより好ましく、メチル基であることが特に好ましい。
一般式（１’）中におけるＲ’は、炭素数２〜３０のアルキル基であることが好ましく、炭素数６〜２０のアルキル基であることがより好ましく、炭素数６〜２０の分枝アルキル基であることが特に好ましい。
前記一般式（１’）で表される構造の化合物は、下記構造の化合物であることが特に好ましい。

上記構造の化合物は、ＩＲＧＡＮＯＸ Ｅ２０１（ＢＡＳＦ社製）として市販品として入手可能である。 (Ii) Compound in which two or more Rs are bonded to each other to form a heterocyclic ring Among the compounds represented by the general formula (1), compounds in which two or more Rs are bonded to each other to form a heterocyclic ring include A compound having a structure represented by the general formula (1 ′) is preferred.

(In the general formula (1 ′), R each independently represents a hydrogen atom, an aliphatic hydrocarbon group or an aryl group, and R may be the same or different from each other. R ′ is an aliphatic hydrocarbon. Represents a group.)
R in the general formula (1 ′) is preferably independently an aliphatic hydrocarbon group, more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group.
R ′ in the general formula (1 ′) is preferably an alkyl group having 2 to 30 carbon atoms, more preferably an alkyl group having 6 to 20 carbon atoms, and a branched alkyl group having 6 to 20 carbon atoms. Particularly preferred is a group.
The compound having the structure represented by the general formula (1 ′) is particularly preferably a compound having the following structure.

The compound having the above structure is commercially available as IRGANOX E201 (manufactured by BASF).

(Iii) Phenolic Resin Among the compounds represented by the general formula (1), the phenolic resin is preferably a novolac phenolic resin.
The novolak-type phenol resin used in the present invention is a normal novolak-type phenol resin obtained by reacting phenol and formaldehyde (formalin) in general under an acidic catalyst such as oxalic acid. There is no restriction | limiting in particular as a raw material of this phenol, For example, phenol, o-cresol, m-cresol, p-cresol, p-tert-butylphenol, p-tert-octylphenol, p-octylphenol, p-nonylphenol etc. and those Mixtures can be used. As a raw material of the phenol, p-cresol is preferable.
Moreover, as a raw material of formaldehyde, formalin, paraform, acetal, etc., and mixtures thereof can be used.

  The structure of the novolac type phenol resin is represented by the following general formula (3).

[一般式（３）中、ｎは平均で１〜１０を表し、Ｒはそれぞれ独立に水素原子または炭素原子数１〜１０のアルキル基を示す。]

[In general formula (3), n represents 1-10 on an average, and R shows a hydrogen atom or a C1-C10 alkyl group each independently. ]

In general formula (3), R represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms is preferred from the viewpoint of durability, and is preferably a methyl group. More preferred.
In the general formula (31), the position of R substituted on each benzene ring of R is not particularly limited, but is preferably para-position to the —OH group.
In general formula (3), it is preferable that n is 1-7.
In general formula (3), the bonding position of the methylene group connecting each benzene ring is not particularly limited, but is preferably in the ortho position with respect to the —OH group.

  Specific examples of the novolac type phenol resin represented by the general formula (3) are given below, but the present invention is not limited to these. Moreover, n in the following specific examples is synonymous with n in General formula (3). Among the following specific examples, A-4 is preferable.

  As the novolak-type phenol resin, a phenol resin (Sumilite Resin PR-HF-3 or the like) manufactured by Sumitomo Bakelite Co., Ltd. can be suitably used.

  The novolac type phenol resin preferably has a weight average molecular weight of 200 to 10,000, more preferably 200 to 5,000, and particularly preferably 200 to 3,000.

(Compound represented by the general formula (2) and having one hydrogen bond donating group)
The compounds represented by the following general formula (2) and having one hydrogen bond donating group are known as so-called barbituric acids.

In the general formula ^{(2), R 1, R} 3 and R ⁵ are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group carbon atoms or a C2-20 6 Represents ˜20 aromatic groups.

In the general formula (2), the alkyl group having 1 to 20 carbon atoms that can be employed as R ¹ , R ³ , and R ⁵ preferably has 1 to 10 carbon atoms, and preferably 1 to 5 carbon atoms. More preferably, it is more preferable that it is 1-3, More preferably, it is a methyl group or an ethyl group.
In the general formula (2), the cycloalkyl group having 3 to 20 carbon atoms that can be employed as R ¹ , R ³ and R ⁵ preferably has 3 to 10 carbon atoms, and preferably 4 to 8 carbon atoms. It is more preferable. Specific examples of the cycloalkyl group include a cyclopropyl group, a cyclopentyl group, and a cyclohexyl group, and a cyclohexyl group is particularly preferable.
In the above general formula (2), the alkenyl group having 2 to 20 carbon atoms that can be employed as R ¹ , R ³ and R ⁵ preferably has 2 to 10 carbon atoms, and preferably 2 to 5 carbon atoms. Is more preferable.
In the general formula (2), the aromatic group of 6 to 20 that can be employed as R ¹ , R ³ and R ⁵ may be an aromatic hydrocarbon group or an aromatic heterocyclic group. An aromatic hydrocarbon group is preferred. As the aromatic hydrocarbon group, a phenyl group and a naphthyl group are preferable, and a phenyl group is more preferable.

In general formula (2), R ¹ , R ³ and R ⁵ may have a substituent, but the substituent is not particularly limited, and is preferably an alkyl group (preferably having 1 to 10 carbon atoms, Methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl group (preferably having 2 to 20 carbon atoms, for example, vinyl, allyl , Oleyl, etc.), alkynyl groups (preferably having 2 to 20 carbon atoms, such as ethynyl, butadiynyl, phenylethynyl, etc.), cycloalkyl groups (preferably having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), aryl groups (preferably having 6 to 26 carbon atoms, such as phenyl, 1-naphthyl, 4-methyl Toxiphenyl, 2-chlorophenyl, 3-methylphenyl, etc.), a heterocyclic group (preferably a heterocyclic group having 0 to 20 carbon atoms, wherein the ring-forming heteroatom is preferably an oxygen atom, a nitrogen atom or a sulfur atom, 5 or 6 The ring may be condensed with a benzene ring or a hetero ring, and the ring may be a saturated ring, an unsaturated ring, or an aromatic ring. For example, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2 -Benzimidazolyl, 2-thiazolyl, 2-oxazolyl, etc.), alkoxy group (preferably having 1 to 20 carbon atoms, for example, methoxy, ethoxy, isopropyloxy, benzyloxy, etc.), aryloxy group (preferably having 6 to 26 carbon atoms) And, for example, phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), alkylthio groups (preferably carbon 1-20, for example, methylthio, ethylthio, isopropylthio, benzylthio, etc., arylthio groups (preferably having 6-26 carbon atoms, for example, phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc. ), Acyl groups (including alkylcarbonyl groups, alkenylcarbonyl groups, arylcarbonyl groups, and heterocyclic carbonyl groups, preferably having 20 or less carbon atoms, such as acetyl, pivaloyl, acryloyl, metachloroyl, benzoyl, nicotinoyl, etc.), aryloyl An alkyl group, an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, for example, ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc.), an aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, for example, phenyloxy Including sulfonyl, naphthyloxycarbonyl, etc.), amino groups (including amino groups, alkylamino groups, arylamino groups, heterocyclic amino groups, preferably having 0 to 20 carbon atoms, such as amino, N, N-dimethylamino, N , N-diethylamino, N-ethylamino, anilino, 1-pyrrolidinyl, piperidino, morphonyl, etc.), sulfonamide group (preferably having 0 to 20 carbon atoms, for example, N, N-dimethylsulfonamide, N-phenylsulfonamide) ), A sulfamoyl group (preferably having 0 to 20 carbon atoms, for example, N, N-dimethylsulfamoyl, N-phenylsulfamoyl, etc.), an acyloxy group (preferably having 1 to 20 carbon atoms, for example, acetyl Oxy, benzoyloxy, etc.), a carbamoyl group (preferably having 1 to 20 carbon atoms such as N , N-dimethylcarbamoyl, N-phenylcarbamoyl, etc.), acylamino group (preferably having 1 to 20 carbon atoms, for example, acetylamino, acryloylamino, benzoylamino, nicotinamide, etc.), cyano group, hydroxyl group, mercapto group or halogen An atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.) is mentioned.

In the general formula (2), the above substituents that R ¹ , R ³ and R ⁵ may have may further have the above substituents.

Here, in the general formula (2), among the above substituents that each of R ¹ , R ³ and R ⁵ may have, an alkyl group, an aryl group, an alkoxy group and an acyl group are preferable.

Among the compounds represented by the general formula (2), preferred compounds are listed as follows.
A compound in which any one of R ¹ , R ³ and R ⁵ is an aralkyl group. The aralkyl group is a compound in which an aryl group is substituted on an alkyl group. Among the aralkyl groups, one or two alkyl groups are substituted. In which the aryl group is substituted (when two aryl groups are substituted, the same carbon atom is preferably substituted). Further, an alkyl group substituted with an aryl group and an acyl group (preferably an aryloyl group) is also preferable.
A compound in which any one of R ¹ , R ³ and R ⁵ is a group containing a cycloalkyl group, and preferably the group containing a cycloalkyl group is a cycloalkyl group

In the compound represented by the general formula (2), R ¹ , R ^3, and R ⁵ are each a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or a carbon number 2 to 20 from the viewpoint of dissolution stability during film formation. Are more preferably an alkenyl group or an aryl group having 6 to 20 carbon atoms, and particularly preferably a hydrogen atom, an alkyl group having a substituent having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. And more preferably a hydrogen atom, an aralkyl group, or an aryl group having 6 to 20 carbon atoms.
Moreover, it is more preferable that at least one of R ¹ , R ³ and R ⁵ has one or more ring structures, and it is particularly preferable to have one ring structure. Furthermore, it is more preferable that two of R ¹ , R ³ and R ⁵ have one or more ring structures, and it is particularly preferable to have one ring structure.

More preferably, the compound represented by the general formula (2) is represented by the following general formula (2-a) or the following general formula (2-b). More particularly preferably, the compound represented by the general formula (2) is particularly preferably represented by the following general formula 2-a.

In General Formula (2-a), L ^{1 to} L ³ each independently represents a single bond or a divalent linking group having 1 or more carbon atoms. L ^{1 to} L ³ are more preferably a single bond or an alkylene group having 1 to 6 carbon atoms, more preferably a single bond, a methylene group or an ethylene group, and particularly preferably a single bond or a methylene group. preferable. In view of the dissolution stability, L ^1, at least one of ~L ³ is preferably an alkylene group having 1 to 6 carbon atoms, at least two of L ¹ ~L ³ is 1 to 6 carbon atoms An alkylene group is more preferable. At least one of L ^{1 to} L ³ is preferably a single bond. The divalent linking group that L ^{1 to} L ³ can represent may have a substituent, and the substituent includes R ¹ , R ^3, and R ⁵ in the general formula (2). It is synonymous with a possible substituent.
In general formula (2-a), Ar ^{1 to} Ar ³ each independently represents an aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. Ar ^{1 to} Ar ³ may have a substituent, and the substituent is synonymous with the substituent that R ¹ , R ^3, and R ⁵ in General Formula (2) may have. Ar ^{1 to} Ar ³ do not have a substituent, or when it has a substituent, the substituent preferably has no ring structure.

In general formula (2-b), R ^1b is a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms. Represents a group. R ^1b is preferably a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and a hydrogen atom or a substituent having 1 to 20 carbon atoms. Is more preferably an alkyl group having 6 or an aryl group having 6 to 20 carbon atoms, particularly preferably a hydrogen atom, an aralkyl group or an aryl group having 6 to 20 carbon atoms, and particularly preferably a hydrogen atom. .
In General Formula (2-b), L ⁴ and L ⁵ each independently represent a single bond or a divalent linking group having 1 or more carbon atoms. L ⁴ and L ⁵ are more preferably a single bond or an alkylene group having 1 to 6 carbon atoms, more preferably a single bond, a methylene group or an ethylene group, and particularly preferably a single bond or a methylene group. preferable. In consideration of dissolution stability, one of L ⁴ and L ⁵ is preferably an alkylene group having 1 to 6 carbon atoms. The other of L ⁴ and L ⁵ is preferably a single bond, and L ⁵ is more preferably a single bond. The divalent linking group that can be represented by L ⁴ and L ⁵ may have a substituent, and the substituent includes R ¹ , R ^3, and R ⁵ in the above general formula (2). It is synonymous with a possible substituent.
In general formula (2-b), Ar ⁴ and Ar ⁵ each independently represents an aryl group having 6 to 20 carbon atoms, preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. Ar ⁴ and Ar ⁵ may have a substituent, and the substituent is synonymous with the substituent that R ¹ , R ^3, and R ⁵ in General Formula (2) may have. Ar ⁴ and Ar ⁵ do not have a substituent, or when they have a substituent, the substituent preferably has no ring structure.

The molecular weight of the compound represented by the general formula (2) is preferably 250 to 1200, more preferably 300 to 800, and particularly preferably 350 to 600.
If the molecular weight is too small, volatilization from the film may be a problem, and if it is too large, the haze may be increased.

  Although the specific example of a compound represented by General formula (2) below is shown, this invention is not limited to these. In the following exemplary compounds, Me represents a methyl group.

It is known that the compound represented by the general formula (2) can be synthesized by using a barbituric acid synthesis method in which a urea derivative and a malonic acid derivative are condensed. Barbituric acid having two substituents on N can be obtained by heating N, N 'disubstituted urea and malonic acid chloride or by combining malonic acid and an activating agent such as acetic anhydride. For example, Journal of the American Chemical Society 61, 1015 (1939), Journal of Medicinal Chemistry, 54, 2409 (2011), Tetrahedron 99, 40, Tetrahedron Letters 99, 40. The method described in WO2007 / 150011 public relations etc. can be used preferably.
The malonic acid used for the condensation may be either unsubstituted or substituted, and if malonic acid having a substituent corresponding to R ⁵ is used, a barbituric acid is constructed to construct the general formula of the present invention. The compound represented by (2) can be synthesized. Further, when an unsubstituted malonic acid and a urea derivative are condensed, a 5-position unsubstituted barbituric acid is obtained. By modifying this, a compound represented by the general formula (2) of the present invention is synthesized. May be.
In addition, the synthesis | combining method of the compound represented by General formula (2) used for this invention is not limited above.

(Aromatic hydrocarbon formaldehyde resin)
As the aromatic hydrocarbon formaldehyde resin used in the present invention, an ordinary aromatic hydrocarbon formaldehyde resin generally obtained by reacting an aromatic hydrocarbon and formaldehyde (formalin) can be used. There is no restriction | limiting in particular as a raw material of this aromatic hydrocarbon, For example, the triisomer of toluene, xylene, a mesitylene, a C10 or more monocyclic aromatic hydrocarbon compound, etc., and mixtures thereof can be used. Among the aromatic hydrocarbons, xylene (so-called xylene resin is obtained) is preferable, and m-xylene is more preferable.
Moreover, as a raw material of formaldehyde, formalin, paraform, acetal, etc., and mixtures thereof can be used.

  The structure of the aromatic hydrocarbon formaldehyde resin is preferably represented by the following general formula (4).

[一般式（４）中、ｎは平均で１〜１０を表し、ｍはそれぞれ独立に１〜３の整数を表し、Ｒはそれぞれ独立にメチル基もしくはエチル基を表し、Ｌ¹およびＬ²はそれぞれ独立にメチレン基または−ＣＨ₂−Ｏ−ＣＨ₂−を表す。]

[In the general formula (4), n represents 1 to 10 on average, m represents an integer of 1 to 3, each independently represents R or each independently represents a methyl group or an ethyl group, and L ¹ and L ² represent Each independently represents a methylene group or —CH ₂ —O—CH ₂ —. ]

In general formula (4), R is preferably a methyl group.
In the general formula (4), the number of R substituted on each benzene ring of R is not particularly limited, but is preferably 0 to 2, and more preferably 2.
In the general formula (4), the position of R substituted on each benzene ring of R is not particularly limited.
In general formula (4), it is preferable that n is 1-7.
In general formula (4), the bonding position of the methylene group or —CH ₂ O— group linked to each benzene ring is not particularly limited, but is preferably in a meta position.

  Specific examples of the aromatic hydrocarbon formaldehyde resin represented by the general formula (4) are given below, but the present invention is not limited thereto. Moreover, n is synonymous with n in General formula (4).

  As the aromatic hydrocarbon formaldehyde resin, a xylene resin (Nikanol Y1000, etc.) manufactured by Fudou Co., Ltd. can be suitably used.

  The aromatic hydrocarbon formaldehyde resin preferably has a molecular weight of 200 to 10,000, more preferably 200 to 5,000, and particularly preferably 200 to 3,000.

  The aromatic hydrocarbon formaldehyde resin can be preferably used when the polymer of the core layer of the polarizing plate protective film of the present invention is a cycloolefin resin.

  In addition, petroleum resins, terpene resins, terpene phenol resins, rosin resins, coumarone resins, and hydrides thereof may also be used together if they have a moisture permeability reducing effect.

Since the polarity varies depending on the type of polymer as the main component of the core layer, the optimum moisture permeability reducing compound can be selected according to the type of polymer as the main component of the core layer.
When the polymer that is the main component of the core layer is a copolymer of styrene and acrylic, the phenol resin can be preferably used as the moisture permeability reducing compound, and a novolac type phenol resin can be more preferably used.
When the polymer that is the main component of the core layer is a cycloolefin resin, the compound represented by the general formula (1) is a compound having at least one phenyl group as R, or two or more compounds as the moisture permeability reducing compound It is preferable to use a compound in which R is bonded to each other to form a heterocyclic ring, a compound represented by the general formula (2), or an aromatic hydrocarbon formaldehyde resin, and more preferably an aromatic hydrocarbon formaldehyde resin. Can do.

  The moisture permeability reducing compound is preferably contained in an amount of 5 to 50% by mass with respect to the mass of the polymer as the main component of the core layer. More preferably, it is 10-40 mass%.

On the other hand, the kind of the moisture permeability reducing compound added to the surface layer is not particularly limited, but the same moisture permeability reducing compound as that used for the core layer in the polarizing plate protective film of the present invention is used. Is preferable from the viewpoint of improving film interface adhesion.
Further, the amount of the moisture permeability reducing compound added to the surface layer is not particularly limited, but the moisture permeability reducing compound is added in the same amount as the moisture permeability reducing compound used for the core layer in the polarizing plate protective film of the present invention. It is preferable to use from the viewpoint of improving film interface adhesion.

<Other additives>
(Matting agent fine particles)
Fine particles can be added as a matting agent to the polarizing plate protective film of the present invention. Fine particles used as a matting agent include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and Mention may be made of calcium phosphate. Fine particles containing silicon are preferred in that the haze of the film is reduced, and silicon dioxide is particularly preferred. The silicon dioxide fine particles preferably have a primary average particle size of 20 nm or less and an apparent specific gravity of 70 g / liter or more. Those having an average primary particle size as small as 5 to 16 nm are more preferred because they can reduce the haze of the film. The apparent specific gravity is preferably 90 to 200 g / liter or more, and more preferably 100 to 200 g / liter or more. A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.

  These fine particles usually form secondary particles having an average particle diameter of 0.1 to 3.0 μm, and these fine particles are present as aggregates of primary particles in the film, and 0.1 to 0.1 μm on the film surface. An unevenness of 3.0 μm is formed. The average particle diameter of the secondary particles is preferably from 0.2 μm to 1.5 μm, more preferably from 0.4 μm to 1.2 μm, and most preferably from 0.6 μm to 1.1 μm. The particle diameter of the primary particles and the secondary particles was determined by observing the particles in the film with a scanning electron microscope and determining the diameter of a circle circumscribing the particles as the particle diameter. In addition, 200 particles were observed at different locations, and the average value was taken as the average particle size.

  As fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. Zirconium oxide fine particles are commercially available, for example, under the trade names Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Among these, Aerosil 200V and Aerosil R972V are fine particles of silicon dioxide having an average primary particle diameter of 20 nm or less and an apparent specific gravity of 70 g / liter or more, and the turbidity of the polarizing plate protective film is kept low. However, it is particularly preferable because the effect of reducing the friction coefficient is great.

  As the solvent used for dispersion, lower alcohols are preferable, and examples thereof include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, and butyl alcohol. Although it does not specifically limit as solvents other than a lower alcohol, It is preferable to use the solvent used at the time of film forming of a polarizing plate protective film.

(Other additives)
In addition to the mat particles, the polarizing plate protective film of the present invention has other various additives (for example, retardation developing agent, plasticizer, ultraviolet absorber, deterioration inhibitor, release agent, infrared absorber, wavelength). Dispersion modifiers etc.) can be added and they can be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of ultraviolet absorbing material at 20 ° C. or lower and 20 ° C. or higher, and similarly mixing of a plasticizer is described in, for example, JP-A-2001-151901. Furthermore, infrared absorbing dyes are described in, for example, JP-A No. 2001-194522. Moreover, the addition time may be added at any time in the dope preparation step, but may be added by adding an additive to the final preparation step of the dope preparation step. Furthermore, the amount of each material added is not particularly limited as long as the function is manifested. Moreover, when a polarizing plate protective film is formed from a multilayer, the kind and addition amount of the additive of each layer may differ. For example, it is described in Japanese Patent Application Laid-Open No. 2001-151902, and these are conventionally known techniques. For these details, materials described in detail on pages 16 to 22 in the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical No. 2001-1745, published on March 15, 2001, Japan Institute of Invention) are preferably used.

  In the polarizing plate protective film of the present invention, when these additives are added, the total amount of the additives is preferably 50% by mass or less based on the core layer or surface layer polymer of the polarizing plate protective film, and 30 It is preferable that it is below mass%.

<Functional layer>
Moreover, it is preferable that the polarizing plate protective film of this invention laminate | stacks a functional layer with a film thickness of 0.1-20 micrometers on at least one surface. The type of the functional layer is not particularly limited, but a hard coat layer, an antireflection layer (a layer having a adjusted refractive index such as a low refractive index layer, a medium refractive index layer, or a high refractive index layer), an antiglare layer, an antistatic layer, An ultraviolet absorption layer, a low moisture permeability layer (moisture permeability reduction layer), etc. are mentioned.
The functional layer may be a single layer or a plurality of layers. The method for laminating the functional layer is not particularly limited, but co-casting of a thermoplastic resin and a polarizing plate protective film containing the moisture permeability reducing compound, or a polarizing plate protective film containing a thermoplastic resin and the moisture permeability reducing compound. It is preferable to be coated on top.
When the functional layer is formed by coating and drying, it is preferable to use a monomer having an ethylenically unsaturated group as a binder. The monomer may be monofunctional or polyfunctional. Among them, it is preferable to use a polymerizable polyfunctional monomer, more preferably a photopolymerizable polyfunctional monomer, and particularly preferably a coating solution containing a monomer having two or more (meth) acryloyl groups. .

Specific examples of the monomer having two or more (meth) acryloyl groups include (meth) alkylene glycols such as neopentyl glycol acrylate, 1,6-hexanediol (meth) acrylate, and propylene glycol di (meth) acrylate. Acrylic acid diesters;
(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-bis {4- (acryloxy · polypropoxy) phenyl} propane ;
Etc.

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

Among these, esters of polyhydric alcohol and (meth) acrylic acid are preferable. A polyhydric alcohol means a dihydric or higher alcohol.
More preferably, a polyfunctional monomer having 3 or more (meth) acryloyl groups in one molecule is preferable. For example, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, ethylene oxide modified trimethylolpropane tri (meth) acrylate, propylene oxide modified trimethylolpropane tri (meth) acrylate, Ethylene oxide modified tri (meth) acrylate phosphate, trimethylolethane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (Meth) acrylate, 1,2,3-cyclohexanetetramethacrylate, polyurethane polyacrylate, Li ester polyacrylate, caprolactone-modified tris (acryloyloxyethyl) isocyanurate.

  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 other polyfunctional monomers, for example, dendrimers described in JP-A-2005-76005 and JP-A-2005-36105 can be used.

As the polyfunctional monomer, esters of polyhydric alcohol and (meth) acrylic acid, and amides of polyhydric alcohol and isocyanate containing a plurality of (meth) acryloyl groups are also preferably used.
The polyhydric alcohol is not particularly limited, but is preferably an aliphatic alcohol, and more preferably an alcohol having a cyclic aliphatic hydrocarbon group. The aliphatic group of the monocyclic alicyclic alcohol is preferably a cycloalkyl group having 3 to 8 carbon atoms, and examples thereof include a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group.
Examples of the aliphatic group of the polycyclic alicyclic alcohol include a group having a bicyclo, tricyclo, tetracyclo structure or the like having 5 or more carbon atoms, and a cycloalkyl group having 6 to 20 carbon atoms is preferable. Adamantyl group, norbornyl group, dicyclopentyl group, tricyclodecanyl group, tetracyclododecyl group, central skeleton of compounds described in claims of JP-A-2006-215096, compound described in JP-A-2001-10999 And the like. A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.
Among them, examples of the polycyclic alcohol include an adamantyl group, a norbornyl group, a dicyclopentyl group, a tricyclodecanyl group, a tetracyclododecyl group, and a central skeleton of the compound described in the claims of JP-A-2006-215096. Polyhydric alcohols having a central skeleton of the compounds described in JP-A No. 2001-10999 are particularly preferred from the viewpoint of reducing moisture permeability.

  Two or more kinds of polymerizable polyfunctional monomers may be used in combination. Polymerization of the monomer having an ethylenically unsaturated group can be performed by irradiation with ionizing radiation or heating in the presence of a photo radical initiator or a thermal radical initiator.

  It is preferable to use a photopolymerization initiator for the polymerization reaction of the photopolymerizable polyfunctional monomer. As the photopolymerization initiator, a photoradical polymerization initiator and a photocationic polymerization initiator are preferable, and a photoradical polymerization initiator is particularly preferable.

  It is also preferable to use the polymerizable polyfunctional monomer in combination with a monofunctional monomer.

  As the monofunctional monomer, a monomer having one (meth) acryloyl group is preferable, and a monomer having one (meth) acryloyl group is usually obtained from a monovalent alcohol and acrylic acid.

The monohydric alcohol may be an aromatic alcohol or an aliphatic alcohol.
As monohydric alcohol, methyl alcohol, n-propyl alcohol, iso-propyl alcohol, n-butyl alcohol, tert-butyl alcohol, n-amyl alcohol, diacetone alcohol, 1-methoxy-2-propanol, furfuryl alcohol 2-octanol, 2-ethylhexanol, nonanol, n-decanol, undecanol, n-dodecanol, trimethylnonyl alcohol, benzyl alcohol, phenethyl alcohol, ethylene glycol monoisoamyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, Examples include ethylene glycol monohexyl ether.
Moreover, about the aliphatic part of aliphatic alcohol, cycloaliphatic may be sufficient. The cycloaliphatic may be monocyclic, polycyclic, or may be bridged in the case of polycyclic. As the monocyclic type, a cycloalkyl group having 3 to 8 carbon atoms is preferable, and examples thereof include a cyclopentyl group, a cyclohexyl group, a cyclobutyl group, and a cyclooctyl group. Examples of the polycyclic type include groups having a bicyclo, tricyclo or tetracyclo structure having 5 or more carbon atoms, and a cycloalkyl group having 6 to 20 carbon atoms is preferable, for example, an adamantyl group, norbornyl group, dicyclopentyl group. , Tricyclodecanyl group, tetracyclododecyl group, central skeleton of the compound described in the claims of JP-A-2006-215096, central skeleton of the compound described in JP-A-2001-10999, and the like. . A part of carbon atoms in the cycloalkyl group may be substituted with a hetero atom such as an oxygen atom.

  The monovalent alcohol, whether it is an aromatic alcohol or an aliphatic alcohol, preferably has 6 or more carbon atoms.

  As (meth) acrylic acid, acrylic acid and methacrylic acid are preferable.

  In addition, as a functional layer, an antireflection layer (a layer having a refractive index adjusted such as a low refractive index layer, a middle refractive index layer, a high refractive index layer), an antiglare layer, an antistatic layer, an ultraviolet absorption layer, a low moisture permeable layer (translucent layer). Various additives may be added to obtain a humidity reduction layer.

  The thickness of the functional layer is more preferably 0.01 to 100 μm, and particularly preferably 0.02 to 50 μm. Furthermore, as a functional layer which reduces a water vapor transmission rate, it is more preferable that it is 0.1-20 micrometers in thickness.

  When the functional layer for reducing the moisture permeability is used, the moisture permeability (C) of the polarizing plate protective film laminated with the functional layer and the moisture vapor transmission rate (D) of the polarizing plate protective film without lamination are C / D. It is desirable to be below 0.9. More preferably, it is 0.85 or less, and more preferably 0.8 or less.

(Composition of low moisture permeable layer)
A low moisture-permeable layer can be preferably used as the functional layer.
The low moisture-permeable layer that can be used for the polarizing plate protective film of the present invention is a layer formed from a composition containing a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond in the molecule, or chlorine. The layer preferably has a resin containing a repeating unit derived from a vinyl monomer, and is formed from a composition containing a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond in the molecule. More preferably, it is a layer.

  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 will be described.

<< Layer formed from a composition mainly composed of a compound having a cycloaliphatic 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. The composition can be formed 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.

  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.

(Polymerization initiator)
The composition containing as a main component a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule preferably contains a polymerization initiator, but a photopolymerization initiator is preferred as the polymerization initiator. .
As photopolymerization initiators, acetophenones, benzoins, benzophenones, phosphine oxides, ketals, anthraquinones, thioxanthones, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, Examples include fluoroamine compounds, aromatic sulfoniums, lophine dimers, onium salts, borate salts, active esters, active halogens, inorganic complexes, and coumarins. Specific examples, preferred embodiments, commercially available products, and the like of the photopolymerization initiator are described in paragraphs [0133] to [0151] of JP-A-2009-098658, and can be suitably used in the present invention as well. it can.

  “Latest UV Curing Technology” {Technical Information Association, Inc.} (1991), p. 159, and “UV Curing System” written by Kiyomi Kato (published by the General Technology Center in 1989), p. Various examples are also described in 65-148 and are useful in the present invention.

  Commercially available photocleavable photoradical polymerization initiators include “Irgacure 651”, “Irgacure 184”, “Irgacure 819”, “Irgacure 907”, “Irgacure 1870” (CGI) manufactured by Ciba Specialty Chemicals Co., Ltd. -403 / Irgacure 184 = 7/3 mixing initiator), "Irgacure 500", "Irgacure 369", "Irgacure 1173", "Irgacure 2959", "Irgacure 4265", "Irgacure 4263", "Irgacure 127", " OXE01 ”, etc .;“ Kayacure DETX-S ”,“ Kayacure BP-100 ”,“ Kayacure BDK ”,“ Kayacure CTX ”,“ Kayacure BMS ”,“ Kayacure 2-EAQ ”,“ Cayacure ”manufactured by Nippon Kayaku Co., Ltd. "ABQ", " “Yacure CPTX”, “Kayacure EPD”, “Kayacure ITX”, “Kayacure QTX”, “Kayacure BTC”, “Kayacure MCA”, etc .; , KIP150, TZT) ", etc., and combinations thereof are preferred examples.

  The content of the photopolymerization initiator in the composition containing as a main component a compound having a cycloaliphatic hydrocarbon group and an unsaturated double bond group in the molecule used in the present invention is the polymerizable content contained in the composition. 0.5-8 mass% is preferable with respect to the total solid content in the composition for hard-coat layer formation from the reason that it sets so that a starting compound may be superposed | polymerized and a starting point may not increase too much, 1-5 The mass% is more preferable.

〔solvent〕
The composition containing as a main component a compound having a cyclic aliphatic hydrocarbon group and an unsaturated double bond group in the molecule used in the present invention can contain a solvent. As the solvent, various solvents can be used in consideration of the solubility of the monomer, the drying property during coating, the dispersibility of the translucent particles, and the like. Examples of such organic solvents include dibutyl ether, dimethoxyethane, diethoxyethane, propylene oxide, 1,4-dioxane, 1,3-dioxolane, 1,3,5-trioxane, tetrahydrofuran, anisole, phenetole, dimethyl carbonate, carbonic acid. Methyl ethyl, diethyl carbonate, acetone, methyl ethyl ketone (MEK), diethyl ketone, dipropyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, methylcyclohexanone, ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, propyl acetate, Methyl propionate, ethyl propionate, γ-ptyrolactone, methyl 2-methoxyacetate, methyl 2-ethoxyacetate, ethyl 2-ethoxyacetate, ethyl 2-ethoxypropionate, 2-metho Siethanol, 2-propoxyethanol, 2-butoxyethanol, 1,2-diacetoxyacetone, acetylacetone, diacetone alcohol, methyl acetoacetate, methyl acetoacetate and other methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, cyclohexyl Alcohol, isobutyl acetate, methyl isobutyl ketone (MIBK), 2-octanone, 2-pentanone, 2-hexanone, ethylene glycol ethyl ether, ethylene glycol isopropyl ether, ethylene glycol butyl ether, propylene glycol methyl ether, ethyl carbitol, butyl carbitol , Hexane, heptane, octane, cyclohexane, methylcyclohexane, ethylcyclohexane, benzene, tolu Examples thereof include ene and xylene, and these can be used alone or in combination of two or more.

  A solvent is used so that the solid content concentration of the composition mainly composed of a compound having a cycloaliphatic hydrocarbon group and an unsaturated double bond group in the molecule is 20-80% by mass. It is preferably used, more preferably 30 to 75% by mass, and still more preferably 40 to 70% by mass.

On the other hand, for the layer having a resin containing a repeating unit derived from the chlorine-containing vinyl monomer, the coating layer described in JP-A-2008-230036 [0042] to [0058] can be preferably used. As a component for forming a layer formed of a composition containing vinylidene chloride as a main component, Asahi Kasei Co., Ltd. among the coating layer materials described in JP-A-2008-230036 [0042] to [0058]. It is preferable to use “Saran Resin R204” manufactured by Life & Living Co., Ltd.
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.

(Configuration of low moisture permeable layer, manufacturing method)
The low moisture-permeable layer may be a single layer or a plurality of layers. The method for laminating the low moisture permeable layer is not particularly limited, but the low moisture permeable layer is formed as a co-cast with the base film, or the low moisture permeable layer is laminated on the base film by coating. The low moisture-permeable layer is preferably provided by being laminated on the base film by coating. That is, in the polarizing plate protective film of the present invention, it is more preferable that the low moisture permeable layer is laminated on the base film by coating.

(Thickness of low moisture permeable layer)
The thickness of the low moisture permeable layer is preferably 1 to 20 μm, more preferably 2 to 18 μm, and particularly preferably 3 to 17 μm.

  The low moisture permeable layer of the polarizing plate protective film of the present invention preferably has a hard coat layer function, an antireflection function, an antifouling function, and the like.

(Other functional layers-optically anisotropic layers-)
The polarizing plate protective film of the present invention may further have an optically anisotropic layer, and an example of a preferred embodiment thereof will be described.
The polarizing plate protective film has a transparent support, an optically anisotropic layer, and a substrate, and the optically anisotropic layer is a layer that causes a retardation, and a film having a certain retardation is in-plane. It may be a uniformly formed optically anisotropic layer, or a patterned optically anisotropic layer in which regions having different slow axes and phase differences are regularly arranged in the plane.
In the polarizing plate protective film of this aspect, the moisture permeability reducing compound having the molecular weight of 200 or more and satisfying the following formula (1) may be included in the transparent support.

The optically anisotropic layer in which the film having a certain retardation is uniformly formed in the plane is preferably a λ / 4 film, and a specific example of the polarizing plate protective film having the λ / 4 film as the optically anisotropic layer. As for a specific aspect, the optically anisotropic layer and the polarizing plate protective film described in JP2012-098772A, JP2012-103689A, JP2012-177894A are appropriately used. Can do.
A polarizing plate protective film having a λ / 4 film as an optically anisotropic layer can be used for a brightness enhancement plate, a 3D liquid crystal display device, and the like, and is particularly useful as a member of an active 3D liquid crystal display device.

Next, a typical example of the patterned optically anisotropic layer will be described.
In the image display device, the first and second retardation regions are patterned optically anisotropic layers arranged uniformly and symmetrically. The first and second retardation regions preferably have in-plane slow axes that are orthogonal to each other.
Furthermore, it is preferable that the in-plane slow axes of the first and second retardation regions are orthogonal to each other and the pattern λ / 4 layer has an in-plane retardation Re of λ / 4. When the patterned optically anisotropic layer of this aspect is combined with a polarizing film, the light that has passed through each of the first and second retardation regions becomes a circularly polarized state in opposite directions, and the right and left eye circles respectively. A polarized image is formed.
Regarding specific embodiments of the polarizing plate protective film having the pattern λ / 4 layer as the optically anisotropic layer, the optically anisotropic layer described in Japanese Patent No. 4825934, the Japanese Patent No. 4887463, and the optical Films can be used as appropriate.

  The polarizing plate protective film is useful as a member of a 3D liquid crystal display device, particularly a passive 3D liquid crystal display device. In this aspect, the polarized image that has passed through each of the first and second phase difference regions is recognized as an image for the right eye or the left eye through polarized glasses or the like. Therefore, it is preferable that the first and second phase difference regions have the same shape so that the left and right images do not become non-uniform, and that the respective arrangements are preferably uniform and symmetrical.

  The patterned optically anisotropic layer is not limited to an embodiment. For example, one in-plane retardation of the first and second retardation regions is λ / 4, and the other in-plane retardation is A display pixel area of 3λ / 4 can be used. Further, a retardation region in which one in-plane retardation of the first and second retardation regions 12a and 12b is λ / 2 and the other in-plane retardation is 0 may be used.

The polarizing plate protective film of the present invention can also be used as an optical compensation film for liquid crystal display devices. A liquid crystal display device includes a liquid crystal cell having a liquid crystal supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and at least one sheet between the liquid crystal cell and the polarizing element. More preferably, the polarizing plate protective film of the present invention is arranged as an optical compensation film. These liquid crystal display devices are preferably TN, IPS, FLC, AFLC, OCB, STN, ECB, VA and HAN mode liquid crystal display devices, more preferably TN, OCB, IPS and VA mode liquid crystal display devices. A mode liquid crystal display device is more preferable.
In that case, you may provide the above-mentioned various functional layers to the polarizing plate protective film of this invention.

<Method for producing polarizing plate protective film>
There is no restriction | limiting in particular in the manufacturing method of the polarizing plate protective film of this invention. Hereinafter, the polymer solution used for forming the core layer of the polarizing plate protective film of the present invention may be referred to as a dope (B), and the polymer solution used for forming the surface layer may be referred to as a dope (A). .

  As a method for producing the polarizing plate protective film of the present invention, production methods such as an inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, and a hot press method can be used. From the viewpoint of suppression of defects and suppression of optical defects such as die lines, solution casting by casting is preferred.

The production method of the polarizing plate protective film of the present invention may use a solution casting method or a melt casting method.
In the case of the melt casting method, the step of casting the thermoplastic resin and the moisture permeation reducing compound on the support to form a polymer film is obtained by melting the thermoplastic resin and the moisture permeation reducing compound. It is preferably a step of casting the polymer film to form a polymer film. As the melt casting method, a method described in detail in JP2009-154301A can be used.
In the case of the solution casting method, the step of casting the thermoplastic resin and the moisture permeation reducing compound on a support to form a polymer film is a high process comprising the thermoplastic resin, the moisture permeability reducing compound and a solvent. A step of casting a molecular solution (dope) on a support to form a polymer film is preferable. The polymer film is formed by casting a polymer solution (dope) containing the thermoplastic resin, the moisture permeability reducing compound and a solvent on a support.
Among them, the method for producing a polarizing plate protective film of the present invention comprises a dope for a surface layer mainly composed of at least one cellulose acylate and a core layer mainly composed of a polymer other than cellulose acylate on a support. Casting a dope for forming a film, and a step of peeling off the film. The total thickness of the surface layer is 0.2 to 10 μm, which is the main component of the dope for the core layer. The polymer is either a cycloolefin resin or a copolymer of styrene and acrylic, and the polymer as the main component of the core layer dope is 18 with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5). It is preferable that the polymer has a solution viscosity of 10 Pa · s to 100 Pa · s when dissolved at a concentration of mass%.

<Preparation of dope>
Regarding the preparation of the polymer solution (dope) used for forming the core layer and the surface layer of the polarizing plate protective film of the present invention, the dissolution method is carried out by a room temperature dissolution method, a cooling dissolution method or a high temperature dissolution method, and further these It is carried out in combination. Regarding these, for example, JP-A-5-163301, JP-A-61-106628, JP-A-58-127737, JP-A-9-95544, JP-A-10-95854, JP-A-10-45950, JP 2000-53784, JP 11-322946, JP 11-322947, JP 2-276830, JP 2000-273239, JP 11-71463, JP 04-259511, JP JP-A-2000-273184, JP-A-11-323017, JP-A-11-302388, etc. describe methods for preparing cellulose acylate solutions. These cellulose acylates can be dissolved in an organic solvent by appropriately applying these techniques to the polymer solution used in the polarizing plate protective film of the present invention. About these details, especially a non-chlorine type | system | group solvent system, it implements by the method described in detail on the 22-25th pages of the above-mentioned technical numbers 2001-1745. Further, the polymer dope solution is usually subjected to solution concentration and filtration, and is also described in detail on page 25 of the above-mentioned official technical number 2001-1745. In addition, when it melt | dissolves at high temperature, it is the case where it is more than the boiling point of the organic solvent to be used, and in that case, it uses in a pressurized state.

(Organic solvent)
An organic solvent (also referred to as a solvent) that dissolves the polymer and forms a dope will be described. Examples of the organic solvent to be used include conventionally known organic solvents, and those having a solubility parameter in the range of 17 to 22 are preferable. Solubility parameters are described, for example, in J. Org. Brandrup, E.I. “Polymer Handbook (4th. Edition)” such as H and the like described in VII / 671 to VII / 714. Lower aliphatic hydrocarbon chloride, lower aliphatic alcohol, ketone having 3 to 12 carbon atoms, ester having 3 to 12 carbon atoms, ether having 3 to 12 carbon atoms, fat having 5 to 8 carbon atoms Group hydrocarbons, aromatic hydrocarbons having 6 to 12 carbon atoms, fluoroalcohols (for example, described in paragraph No. [0020] of JP-A-8-143709, paragraph No. [0037] of JP-A-11-60807) Compound) and the like.

The solvent used in the present invention may be used alone or in combination, but it is preferable to use a mixture of a good solvent and a poor solvent in order to impart planar stability, more preferably a mixture of a good solvent and a poor solvent. The ratio of the good solvent is 60 to 99% by mass, and the poor solvent is 40 to 1% by mass. In the present invention, the good solvent means a resin that dissolves the resin used alone, and the poor solvent means a resin that swells or does not dissolve the resin used alone. Examples of the good solvent used in the present invention include organic halogen compounds such as methylene chloride and dioxolanes. Moreover, as a poor solvent used for this invention, methanol, ethanol, n-butanol, a cyclohexane etc. are used preferably, for example.
Drying on the support (casting substrate) after film formation that the proportion of alcohol in the organic solvent contained in the dopes (A) and (B) is 10 to 50% by mass of the whole organic solvent. It is preferable for the reason that the time can be shortened and it can be quickly peeled off and dried, and more preferably 15 to 30% by mass.
Furthermore, in the organic solvent contained in the dope (A) and the dope (B), the ratio of methanol to the total organic solvent in the dope is 20 to 35% by mass. It is preferable from the viewpoint of improving and improving reworkability. Here, the reworkability means that for the purpose of improving the yield when manufacturing a polarizing plate or a liquid crystal display device, a polarizing plate protective film and a polarizer are bonded together to manufacture a polarizing plate, and then the polarizing plate is liquid crystal. It means a performance that allows the polarizing plate to be peeled off and attached again after being once attached to the glass substrate of the cell. The ratio of methanol to the total organic solvent in the dope is more preferably 21 to 35% by mass, and particularly preferably 25 to 30% by mass.

  The material forming the film is preferably dissolved in an organic solvent at a concentration of 10 to 60% by mass, more preferably 10 to 50% by mass. When the cellulose acylate resin is a main component, it is preferably dissolved by 10 to 30% by mass, more preferably 13 to 27% by mass, and particularly preferably 15 to 25% by mass. The method for preparing these concentrations may be prepared so as to have a predetermined concentration at the stage of dissolution, or prepared in advance as a low concentration solution (for example, 9 to 14% by mass) and then a predetermined high concentration in the concentration step. You may adjust to a solution. Furthermore, it is good also as a solution of the predetermined | prescribed low concentration by adding various additives later as a solution of the material which forms a high concentration light transmissive base material beforehand.

(Dope solid content concentration)
In the above production method, the solid content concentration of the dope (B) (concentration of the component that becomes solid after the dope drying) is appropriately selected according to the molecular weight, but suitable for solution casting film formation. In order to obtain a dope having a high viscosity, the solid content concentration is preferably 16 to 30% by mass. Conventionally, it has been considered that the solid content concentration is preferably 30 to 50% because the content of the organic solvent can be reduced and the drying time can be shortened. From the viewpoint of obtaining the effects of the present invention, it was found that the solid content concentration is more preferably adjusted. The solid content concentration of the dope (B) is more preferably 16 to 30% by mass, and particularly preferably 18 to 25% by mass.

  In the manufacturing method, it is preferable that the solid content concentration of the dope (A) and the dope (B) is 16 to 30% by mass.

On the other hand, in the manufacturing method, in order to obtain a good planar film by co-casting, the solid content concentration of the dope (B) is set to the same level as the solid content concentration of the dope (A). It is preferable. The difference in solid content between the dope (B) and the dope (A) is preferably within 10% by mass, and more preferably within 5% by mass.
In particular, in the dope (B), the concentration of the sum of the components that become solid after drying is 16 to 30% by mass, and the difference in concentration between the dope (B) and the dope (A) is within 10% by mass. Is preferred.

(Complex viscosity of dope)
In the production method, the solution viscosity (hereinafter also referred to as complex viscosity) when the polymer of the dope (B) is dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5). 10 Pa · s to 100 Pa · s.
In the manufacturing method, it is preferable that the solution viscosity of the dope (A) and the dope (B) is 20 to 90 Pa · s or less. By setting the complex viscosity in such a range, the solution casting suitability tends to be further improved, which is preferable.
More preferably, it is 25-70 Pa * s, Most preferably, it is 30-60 Pa * s.

  In the production method, the viscosity of the dope at the time of casting may be different between the surface layer and the core layer, and the viscosity of the surface layer is preferably smaller than the viscosity of the core layer, but the viscosity of the core layer is higher than the viscosity of the surface layer. It may be small. In the production method of the present invention, among them, the complex viscosity of the dope (A) and the dope (B) is 10 to 80 Pa · s or less, and the complex viscosity of the dope (B) is the dope ( It is preferable that it is larger than the complex viscosity of A) from the viewpoint of improving the film surface shape after film formation.

(Composition of dope thermoplastic resin)
Furthermore, from the viewpoint of achieving support releasability, interfacial adhesion, low curl, etc., the composition of the thermoplastic resin in the dopes (A) and (B) preferably satisfies the following conditions. The proportion of cellulose acylate in the thermoplastic resin in the dope (A) is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and most preferably 80 to 100% by mass. The proportion of the cycloolefin resin or styrene / acrylic copolymer in the polymer in the dope (B) is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and most preferably 95 to 100%. % By mass.

  In the manufacturing method, the two or more kinds of dopes are cast on a casting base material to form a film. There is no restriction | limiting in particular as a manufacturing method of the film of this invention other than the above, A well-known co-casting method can be used. For example, a film may be produced while casting and laminating a dope solution from a plurality of casting openings provided at intervals in the traveling direction of the metal support. For example, Japanese Patent Application Laid-Open No. 61-158414, The methods described in Japanese Laid-Open Patent Publication Nos. 1-122419 and 11-198285 can be applied. Further, the dope solution may be cast from two casting ports or formed into a film. For example, Japanese Patent Publication Nos. 60-27562, 61-94724, 61-947245, 61-947245, It can be carried out by the methods described in JP-A-61-104813, JP-A-61-158413, and JP-A-6-134933.

  In the production method, it is preferable that at least two kinds of dopes (A) and (B) are simultaneously co-cast in order from the casting substrate side. Furthermore, in the production method of the present invention, it is preferable that the co-casting is performed in the order of the dopes (A), (B), and (A) in order from the base material side and from the support side. Here, a plurality of (A) in one laminated film may have the same composition or different compositions.

  In the case of co-casting, it is possible to produce a laminated film by co-casting dope solutions having different additive concentrations such as the above-mentioned plasticizer, ultraviolet absorber and matting agent. For example, the matting agent can be contained in the surface layer on the support surface side or in the surface layer on the support surface side only. The plasticizer and the ultraviolet absorber can be contained in the core layer more than the surface layer, and may be contained only in the core layer. Also, the type of plasticizer and ultraviolet absorber can be changed between the core layer and the surface layer. For example, the surface layer contains a low-volatile plasticizer and / or an ultraviolet absorber, and the core layer is a plasticizer with excellent plasticity. Alternatively, an ultraviolet absorber excellent in ultraviolet absorption can be added.

<Drying process>
It is preferable that the manufacturing method includes a step of removing the organic solvent.
A method for drying a web that has been dried on a drum and peeled is described. The web peeled at the peeling position just before the drum makes one turn is conveyed by alternately passing through a group of rolls arranged in a staggered manner, or the both ends of the peeled web are gripped with clips or the like and are not contacted It is conveyed by the method of conveying it automatically. Drying is performed by a method of applying wind at a predetermined temperature to both sides of the web (film) being conveyed or a method using a heating means such as a microwave. Since rapid drying may impair the flatness of the film to be formed, it is preferable to dry at a temperature at which the solvent does not foam in the initial stage of drying, and to dry at a high temperature after the drying proceeds. In the drying process after peeling from the support, the film tends to shrink in the longitudinal direction or the width direction by evaporation of the solvent. Shrinkage increases with drying at higher temperatures. Drying while suppressing this shrinkage as much as possible is preferable for improving the flatness of the finished film. From this point, for example, as shown in Japanese Patent Laid-Open No. 62-46625, a method in which all or part of the drying process is performed while holding the width at both ends of the web with clips or pins in the width direction. (Tenter method) is preferable. It is preferable that the drying temperature in the said drying process is 100-145 degreeC. The drying temperature, the amount of drying air, and the drying time vary depending on the solvent used, but may be appropriately selected according to the type and combination of the solvents used.

  It is preferable to dry the multilayer cast dope and then peel it from the support. The time for the dope to be cast and peeled on the casting substrate, that is, the time for the dope to be conveyed on the casting substrate is preferably within 60 seconds, and more preferably within 30 seconds.

<Extension process>
The manufacturing method may include a step of stretching the formed laminated film after the film forming step. For example, when it is necessary to further improve the brittleness of the film of the present invention, the brittleness can be improved by a stretching process.
In the said manufacturing method, it is preferable to extend | stretch the web (film) peeled from the support body when the amount of residual solvents in a web is less than 120 mass%.

The residual solvent amount can be expressed 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 web of which M is measured is dried at 110 ° C. for 3 hours. If the amount of residual solvent in the web is too large, the effect of stretching cannot be obtained, and if it is too small, stretching becomes extremely difficult and the web may break. The more preferable range of the residual solvent amount in the web is most preferably 10% by mass to 50% by mass, particularly 12% by mass to 35% by mass. Further, if the stretching ratio is too small, a sufficient phase difference cannot be obtained, and if it is too large, stretching may become difficult and breakage may occur.

The draw ratio can be 5% to 100%, and preferably 15% to 40%. Here, extending from 5% to 100% in one direction means that the distance between clips and pins supporting the film is in the range of 1.05 to 2.00 times the distance before stretching. Means.
Stretching may be performed in the film transport direction (longitudinal direction), in the direction orthogonal to the film transport direction (transverse direction), or in both directions.

In the above production method, a solution cast film can be stretched without heating to a high temperature as long as the residual solvent amount is in a specific range, but if drying and stretching are combined, the process can be shortened. preferable. In the said manufacturing method, it is preferable that the extending | stretching temperature in the said extending process is 110-190 degreeC, and it is more preferable that it is 120-150 degreeC. The stretching temperature is preferably 120 ° C. or higher from the viewpoint of lowering haze, and 150 ° C. or lower is preferable from the viewpoint of enhancing optical expression (thin film forming).
On the other hand, since the plasticizer volatilizes when the temperature of the web is too high, the range of room temperature (15 ° C.) to 145 ° C. or lower is preferable when using a low molecular plasticizer that easily volatilizes as a plasticizer.

  In addition, stretching in biaxial directions perpendicular to each other is an effective method from the viewpoint of improving the optical expression of the film, particularly from the viewpoint of increasing the Rth (retardation) value of the film.

In the said manufacturing method, you may extend | stretch to a biaxial direction simultaneously in an extending | stretching process, and may extend | stretch to a biaxial direction sequentially. When extending | stretching to a biaxial direction sequentially, you may change extending | stretching temperature for every extending | stretching in each direction.
In the case of simultaneous biaxial stretching, the film of the present invention can be obtained even when the stretching temperature is 110 ° C. to 190 ° C., and the stretching temperature in the case of simultaneous biaxial stretching is 120 ° C. to 150 ° C. More preferably, it is 130 to 150 degreeC. Further, by simultaneous biaxial stretching, the haze is increased to some extent, but the optical expression can be further enhanced.
On the other hand, when sequentially biaxially stretching, it is preferable to first stretch in a direction parallel to the film transport direction and then stretch in a direction orthogonal to the film transport direction. A more preferable range of the stretching temperature at which the successive stretching is performed is the same as the stretching temperature range at which the simultaneous biaxial stretching is performed.

<Heat treatment process>
The manufacturing method preferably includes a heat treatment step after the drying step. The heat treatment in the heat treatment step may be performed after completion of the drying step, and may be performed immediately after the stretching / drying step, or may be separately provided only after the winding process is performed by a method described later after the completion of the drying step. . In the present invention, it is preferable to provide the heat treatment step again after the drying step is once cooled to room temperature to 100 ° C. or less. This is because a film having better thermal dimensional stability can be obtained. For the same reason, it is preferable that the amount of residual solvent is dried to less than 2% by mass, preferably less than 0.4% by mass immediately before the heat treatment step.

The heat treatment is performed by a method of applying a wind at a predetermined temperature to the film being conveyed or a method using a heating means such as a microwave.
The heat treatment is preferably performed at a film surface temperature of 150 to 200 ° C., more preferably 160 to 180 ° C. The heat treatment is preferably performed for 1 to 20 minutes, more preferably 5 to 10 minutes.

(Heated steam treatment)
In addition, the stretched film may be manufactured through a process of spraying steam heated to 100 ° C. or higher. By passing through this water vapor spraying step, the residual stress of the polarizing plate protective film to be produced is relaxed, and the dimensional change is reduced, which is preferable. The temperature of the water vapor is not particularly limited as long as it is 100 ° C. or higher, but considering the heat resistance of the film, the temperature of the water vapor is 200 ° C. or lower.

<Surface treatment process>
When the polarizing plate protective film of the present invention is adhered to a polarizer, from the viewpoint of adhesiveness with the polarizer, a treatment to make the surface hydrophilic such as acid treatment, alkali treatment, plasma treatment, corona treatment, etc. is performed. It is particularly preferable to do this.

[Polarizer]
The polarizing plate of the present invention is characterized by having a polarizer and at least one polarizing plate protective film of the present invention.
In this case, it can serve as an optical compensation film for a liquid crystal display device and a protective film for a polarizing plate. A method for manufacturing the polarizing plate is not particularly limited, and the polarizing plate can be manufactured by a general method. There is a method in which the obtained polarizing plate protective film is subjected to alkali treatment, and a polarizer prepared by immersing and stretching a polyvinyl alcohol film in an iodine solution is bonded to both surfaces using a completely saponified polyvinyl alcohol aqueous solution. Instead of alkali treatment, easy adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be performed. Further, the surface treatment as described above may be performed.
Examples of the adhesive used to bond the protective film treated surface and the polarizer include polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, vinyl latexes such as butyl acrylate, and the like.
The polarizing plate is composed of a polarizer and a polarizing plate protective film that protects both sides of the polarizer, and further comprises a protective film on one surface of the polarizing plate and a separate film on the other surface. The protective film and the separate film are used for the purpose of protecting the polarizing plate at the time of shipping the polarizing plate and at the time of product inspection. In this case, the protect film is bonded for the purpose of protecting the surface of the polarizing plate, and is used on the side opposite to the surface where the polarizing plate is bonded to the liquid crystal plate. Moreover, a separate film is used in order to cover the adhesive layer bonded to a liquid crystal plate, and is used for the surface side which bonds a polarizing plate to a liquid crystal plate.
In a liquid crystal display device, a substrate including a liquid crystal cell is usually disposed between two polarizing plates. The polarizing plate protective film of the present invention can be used as any polarizing plate protective film of two polarizing plates. Of the two polarizing plate protective films of each polarizing plate, it may be used as a polarizing plate protective film disposed on the side opposite to the liquid crystal cell with respect to the polarizer, and on the liquid crystal cell side with respect to the polarizer. You may use as a polarizing plate protective film arrange | positioned.

(Optical compensation film)
The polarizing plate protective film of the present invention can be used in various applications, and is particularly effective when used as an optical compensation film for a liquid crystal display device. The optical compensation film is generally used for a liquid crystal display device and refers to an optical material that compensates for a retardation, and is synonymous with a retardation plate, an optical compensation sheet, and the like. The optical compensation film has birefringence and is used for the purpose of removing the color of the display screen of the liquid crystal display device or improving the viewing angle characteristics.

  The polarizing plate protective film of the present invention may itself be an optical compensation film, or may be used as a support for the optical compensation film, and an optically anisotropic layer may be provided thereon. The optically anisotropic layer is not limited to the optical performance or driving method of the liquid crystal cell of the liquid crystal display device in which the polarizing plate protective film of the present invention is used, and any optical anisotropy required as an optical compensation film Layers can also be used in combination. The optically anisotropic layer used in combination may be formed from a composition containing a liquid crystalline compound or may be formed from a thermoplastic film having birefringence.

[Liquid Crystal Display]
The liquid crystal display device of the present invention includes a liquid crystal cell and the polarizing plate of the present invention disposed in at least one of the liquid crystal cells, and the polarizing plate protective film of the present invention contained in the polarizing plate is the outermost layer. It is arranged as follows.

(Types of liquid crystal display devices)
The film of the present invention can be used for liquid crystal cells in various display modes. TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), AFLC (Anti-Ferroly Liquid Liquid Crystal), OCB (Optically QuantNW). Various display modes such as ECB (Electrically Controlled Birefringence) and HAN (Hybrid Aligned Nematic) have been proposed. In addition, a display mode in which the above display mode is oriented and divided has been proposed. The polarizing plate protective film of the present invention is effective in any display mode liquid crystal display device. Further, it is effective in any of a transmissive type, a reflective type, and a transflective liquid crystal display device.

  Hereinafter, the present invention will be specifically described based on examples. The materials, reagents, amounts and ratios of substances, operations, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the present invention is not limited to the following examples.

上記構造式で表される化合物を、特開平１−２４０５１７号公報の実施例に従って合成した。この際、ＪＳＲ Ｔｅｃｈｎｉｃａｌ Ｒｅｖｉｅｗ Ｎ０．１０８（２００１）記載に従い、連鎖移動剤１−ヘキセンの量を変更することにより、分子量を調整した。こうして得られたノルボルネン系重合体水素化物Ａ−１の溶液粘度は４０Ｐａ・ｓ、Ａ−２の溶液粘度は１５Ｐａ・ｓ、Ａ−３の溶液粘度は８０Ｐａ・ｓ、Ａ−４の溶液粘度は５Ｐａ・ｓであった。 [Preparation of materials]
(Polymer used for core layer and surface layer)
The polymers described below were used.
-Preparation of hydride of norbornene polymer-

The compounds represented by the above structural formula were synthesized according to the examples of JP-A-1-240517. At this time, according to the description in JSR Technical Review N0.108 (2001), the molecular weight was adjusted by changing the amount of the chain transfer agent 1-hexene. The solution viscosity of the norbornene polymer hydride A-1 thus obtained was 40 Pa · s, the solution viscosity of A-2 was 15 Pa · s, the solution viscosity of A-3 was 80 Pa · s, and the solution viscosity of A-4 was It was 5 Pa · s.

-Styrene / acrylic copolymer-
Styrene / acrylic copolymers can be obtained commercially or by known synthesis methods. As raw materials, the following styrene / acrylic copolymers were prepared by changing the polymerization ratio of styrene and methyl methacrylate (the following polymerization ratio represents the weight ratio) and the synthesis conditions.
Styrene / acryl-1, styrene / acryl-2 (styrene / methyl methacrylate = 4/6 copolymer, different molecular weight. Polymer solution viscosity is 40 Pa · s for styrene / acryl-1, styrene / acryl-2 Is 5 Pa · s)
・ Styrene / acryl-3 (styrene / methyl methacrylate = 5/5 copolymer)
・ Styrene / acryl-4 (styrene / methyl methacrylate = 8/2 copolymer)

-Polymer of core layer used in comparative example-
As the polymer of the core layer used in the comparative example, these polymers using the following polymers are commercially available or can be obtained by a known synthesis method.
-As acrylic-1, the polymethylmethacrylate which is the acrylic-1 described in the Example of Unexamined-Japanese-Patent No. 2012-93714 was used.
-As polystyrene, brand name G9504 and the product made by PS Japan were used.

(Additives for core layer and surface layer)
The following compounds were used as additives for the core layer and surface layer.
2,6-diphenylphenol (the following structure, manufactured by Wako Pure Chemical Industries, molecular weight 246, compound B-7)

(UV absorber)
In addition to the above additives, the following ultraviolet absorbers were used for the core layer and the surface layer.
-Tinuvin 328 (Ciba Specialty Chemicals Co., Ltd.)

[Example 1]
(Dope preparation)
The composition described below was put into a mixing tank and stirred while heating to dissolve each component to prepare a dope.
Details of the composition of the dope used in Example 1 are shown below.

<Dope for core layer in Example 1>
Norbornene polymer hydride A-1 100 parts by mass 2,6-diphenylphenol 10.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 486 parts by mass Methanol 25.6 parts by mass <Dope for surface layer in Example 1>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass 2,6-diphenylphenol 10.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 561 parts by mass Methanol 29.5 parts by mass

(Measurement of polymer solution viscosity)
The solution viscosity in the present invention refers to a complex viscosity measured by solution shear rheometer measurement.
The sample solution for the core layer was prepared by dissolving the target sample at a concentration of 18% by mass with respect to a mixed solution of dichloromethane / methanol = 95/5 mass ratio.
A rheometer (CLS500) and a Steel Cone with a diameter of 4 cm (both manufactured by TA Instruments) were used for the measurement, and the frequency was 1 Hz. The sample solution was kept at the measurement start temperature until the liquid temperature was kept constant, and then the measurement was started. The measurement temperature was 25 ° C.
The sample solution for the surface layer was obtained by using each polymer whose solution viscosity of the polymer at a concentration of 18% by mass was found in this way, and the target sample was 16% by mass with respect to a mixed solution of dichloromethane / methanol = 95/5 mass ratio. It was prepared by dissolving at a concentration of.

<Preparation of polarizing plate protective film>
A polarizing plate protective film was prepared by the following procedure so as to have the configuration described in Table 1. First, the dope was cast on the metal support so as to have the layer structure shown in Table 1 through a casting giesser capable of co-casting three layers. Next, while being on the metal support, the dope is dried with a drying air of 40 ° C. to form a polarizing plate protective film, and then peeled off, and both ends of the film are fixed with clips, and the gap is kept at the same interval. It dried for 5 minutes with the drying wind of 105 degreeC. Then, after removing the clip, it was further dried at 130 ° C. for 20 minutes.
The obtained polarizing plate protective film was used as the polarizing plate protective film of Example 1.

[Examples 2 to 17, Comparative Examples 1 to 7]
In the production of the polarizing plate protective film of Example 1, the type of core layer polymer and the type and amount of additives were set as shown in Table 1. Other casting film forming conditions were the same as the polarizing plate protective film 001 of Example 1, and polarizing plate protective films of Examples and Comparative Examples were produced.
Details of the composition of the dope used in each example and comparative example are shown below.

<Dope for core layer in Example 2>
Norbornene polymer hydride A-1 100 parts by mass 3-phenylphenol 10.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 486 parts by mass Methanol 25.6 parts by mass <Dope for surface layer in Example 2>
Same as the surface layer dope in Example 1.

<Dope for core layer in Example 3>
Norbornene polymer hydride A-1 100 parts by mass IRGANOX E201 10.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 486 parts by mass Methanol 25.6 parts by mass <Dope for surface layer in Example 3>
Same as the surface layer dope in Example 1.

<Dope for core layer in Example 4>
Norbornene polymer hydride A-1 100 parts by mass Nicanol Y-50 10.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 486 parts by mass Methanol 25.6 parts by mass <Dope for surface layer in Example 4>
Same as the surface layer dope in Example 1.

<Dope for core layer in Example 5>
Norbornene polymer hydride A-1 100 parts by mass Nicanol Y-50 30.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 573 parts by mass Methanol 30.2 parts by mass <Dope for surface layer in Example 5>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass Nikanol Y-50 30.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 660 parts by mass Methanol 34.8 parts by mass

<Dope for core layer in Example 6>
Norbornene polymer hydride A-1 100 parts by mass Nikanol Y-50 30.0 parts by mass Compound X 4.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 590 parts by mass Methanol 31.1 parts by mass <In Example 6 Surface layer dope>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass Nicanol Y-50 30.0 parts by mass Compound X 4.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 680 parts by mass Methanol 35.8 parts by mass

<Dope for core layer in Example 7>
Norbornene-based polymer hydride A-2 100 parts by mass Nicanol Y-50 30.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 573 parts by mass Methanol 30.2 parts by mass <Dope for surface layer in Example 7>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass Nikanol Y-50 30.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 660 parts by mass Methanol 34.8 parts by mass

<Dope for core layer in Example 8>
Norbornene polymer hydride A-3 100 parts by mass Nikanol Y-50 30.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 573 parts by mass Methanol 30.2 parts by mass <Dope for surface layer in Example 8>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass Nikanol Y-50 30.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 660 parts by mass Methanol 34.8 parts by mass

<Dope for core layer in Example 9>
Norbornene polymer hydride A-1 100 parts by mass Compound Y 30.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 573 parts by mass Methanol 30.2 parts by mass <Dope for surface layer in Example 9>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass Compound Y 30.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 660 parts by mass Methanol 34.8 parts by mass

<Dope for core layer in Example 10>
Norbornene polymer hydride A-1 100 parts by mass Nicanol Y-50 3.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 456 parts by mass Methanol 24.0 parts by mass <Dope for surface layer in Example 10>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass Nikanol Y-50 3.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 526 parts by mass Methanol 27.7 parts by mass

<Dope for core layer in Comparative Example 1>
Norbornene polymer hydride A-1 100 parts by mass Dichloromethane 433 parts by mass Methanol 22.8 parts by mass In Comparative Example 1, no surface layer was provided.

<Dope for core layer in Comparative Example 2>
The same composition as the core layer dope in Example 4 was used.
<Dope for surface layer in Comparative Example 2>
The same composition as the surface layer dope in Example 4 was used. However, in Comparative Example 2, the coating thickness of the surface layer dope was applied to both the air surface side and the support surface side so that the film thickness of each surface layer was 8 μm.

<Dope for core layer in Comparative Example 3>
Norbornene polymer hydride A-4 100 parts by mass Dichloromethane 433 parts by mass Methanol 22.8 parts by mass <Dope for surface layer in Comparative Example 3>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass Dichloromethane 499 parts by mass Methanol 26.3 parts by mass

<Dope for core layer in Example 11>
Styrene-acrylic-1
(Styrene / methyl methacrylate = 4/6 copolymer) 100 parts by mass PR-HF-3 10.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 445 parts by mass Methanol 66.6 parts by mass <Surface layer in Example 11 For dope>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass PR-HF-3 10.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 513 parts by mass Methanol 76.7 parts by mass

<Dope for core layer in Example 12>
Styrene-acrylic-1
(Styrene / methyl methacrylate = 4/6 copolymer) 100 parts by mass p-cresol novolak 10.0 parts by mass Tinuvin 328 2.4 parts by mass dichloromethane 445 parts by mass Methanol 66.6 parts by mass <for surface layer in Example 12 Dope>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass p-cresol novolac 10.0 parts by mass Tinuvin 328 2.4 parts by mass dichloromethane 513 parts by mass methanol 76.7 parts by mass

<Dope for core layer in Example 13>
Styrene-acrylic-1
(Styrene / methyl methacrylate = 4/6 copolymer) 100 parts by mass PR-HF-3 5.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 426 parts by mass Methanol 63.6 parts by mass <Surface layer in Example 13 For dope>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass PR-HF-3 5.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 491 parts by mass Methanol 73.3 parts by mass

<Dope for core layer in Example 14>
Styrene-acrylic-1
(Styrene / methyl methacrylate = 4/6 copolymer) 100 parts by mass PR-HF-3 3.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 418 parts by mass Methanol 62.4 parts by mass <Surface layer in Example 14 For dope>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass PR-HF-3 3.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 481 parts by mass Methanol 71.9 parts by mass

<Dope for core layer in Example 15>
Styrene-acrylic-1
(Styrene / methyl methacrylate = 4/6 copolymer) 100 parts by mass Dichloromethane 396 parts by mass Methanol 59.2 parts by mass <Dope for surface layer in Example 15>
Cellulose triacetate (Substitution degree = 2.86) 100 parts by mass Dichloromethane 457 parts by mass Methanol 68.3 parts by mass

<Dope for core layer in Comparative Example 4>
Styrene-acrylic-1
(Styrene / methyl methacrylate = 4/6 copolymer) 100 parts by mass Dichloromethane 396 parts by mass Methanol 59.2 parts by mass In Comparative Example 4, no surface layer was provided.

<Dope for core layer in Comparative Example 5>
Styrene-acrylic-2
(Styrene / methyl methacrylate = 4/6 copolymer) 100 parts by mass Dichloromethane 396 parts by mass Methanol 59.2 parts by mass <Dope for surface layer in Comparative Example 5>
Cellulose triacetate (Substitution degree = 2.86) 100 parts by mass Dichloromethane 457 parts by mass Methanol 68.3 parts by mass

<Dope for core layer in Example 16>
Styrene-acrylic-3
(Styrene / methyl methacrylate = 5/5 copolymer) 100 parts by mass PR-HF-3 5.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 426 parts by mass Methanol 63.6 parts by mass <Surface layer in Example 16 For dope>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass PR-HF-3 5.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 491 parts by mass Methanol 73.3 parts by mass

<Dope for core layer in Example 17>
Styrene-acrylic-4
(Styrene / methyl methacrylate = 8/2 copolymer) 100 parts by mass PR-HF-3 5.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 426 parts by mass Methanol 63.6 parts by mass <Surface layer in Example 17 For dope>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass PR-HF-3 5.0 parts by mass Tinuvin 328 2.4 parts by mass Dichloromethane 491 parts by mass Methanol 73.3 parts by mass

<Dope for core layer in Comparative Example 6>
Acrylic-1
(Polymethyl methacrylate) 100 parts by mass Dichloromethane 396 parts by mass Methanol 59.2 parts by mass <Dope for surface layer in Comparative Example 6>
Cellulose triacetate (Substitution degree = 2.86) 100 parts by mass Dichloromethane 457 parts by mass Methanol 68.3 parts by mass

<Dope for core layer in Comparative Example 7>
Polystyrene 100 parts by mass Dichloromethane 419 parts by mass Methanol 36.4 parts by mass <Dope for surface layer in Comparative Example 7>
Cellulose triacetate (degree of substitution = 2.86) 100 parts by mass Dichloromethane 483 parts by mass Methanol 42.0 parts by mass

[Evaluation of polarizing plate protective film]
(Water permeability of film)
The moisture permeability of the film was measured under the conditions of 40 ° C. and relative humidity 90% based on JIS Z-0208. For samples with different film thicknesses, the reference was set at 40 μm, and the following formula was used.
Mathematical formula: moisture permeability in terms of 40 μm = measured moisture permeability × measured film thickness (μm) / 40 (μm).
The obtained results are shown in Table 1 below.

(Evaluation of interfacial adhesion of film)
The adhesion evaluation was performed by the following method.
A cross cut test according to JIS K-5600 was conducted. On the surface of the film, 11 cuts were made vertically and horizontally at 1 mm intervals to make 100 1 mm square grids.
A transparent pressure-sensitive adhesive tape was affixed on this, and the part peeled off quickly was evaluated by adhesion by visual observation.
Samples were conditioned for 2 hours or more in a room at a temperature of 25 ° C. and a humidity of 60% before adhesion evaluation, and then evaluated according to the following criteria. The evaluation B or higher is allowable, but the evaluation C or lower is not allowable.
A: No peeling occurrence B: Peeling location 1 to 10 squares C: Peeling location 11 squares to 99 squares D: Peeling location 100 squares or more (all parts pasted with tape)
The obtained results are shown in Table 1 below.

[Preparation of polarizing plate]
After immersing the polarizing plate protective film of each Example and Comparative Example and Fujitac TD60UL (manufactured by Fuji Film Co., Ltd.) in a 4.5 mol / L sodium hydroxide aqueous solution (saponification solution) adjusted to 37 ° C. for 1 minute, The film was washed with water, then immersed in a 0.05 mol / L sulfuric acid aqueous solution for 30 seconds, and then passed through a washing bath. 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.
According to Example 1 of Japanese Patent Laid-Open No. 2001-141926, a peripheral speed difference was given between two pairs of nip rolls, and the film was stretched in the longitudinal direction to prepare a polarizer having a thickness of 20 μm.
The polarizer thus obtained, the polarizing plate protective film of each of the examples and comparative examples subjected to the saponification treatment and Fujitac TD60UL were selected, and the polarizer was sandwiched between them, and then PVA (Kuraray Co., Ltd.) was selected. Manufactured, PVA-117H) 3% aqueous solution was used as an adhesive, and a polarizing plate was prepared by laminating with a roll-to-roll so that the polarization axis and the longitudinal direction of the film were orthogonal. Here, one film of the polarizer was a saponified film selected from the polarizing plate protective film group described in Table 1, and the other film was a film saponified Fujitac TD60UL. The obtained polarizing plate was made into the polarizing plate of each Example and a comparative example.

[Evaluation of polarizing plate]
<Evaluation of polarizer adhesion>
At the time of producing the polarizing plates of each Example and Comparative Example, the polarizer adhesive property of the polarizing plate protective film of the present invention was examined and evaluated according to the following criteria.
A: Adhesiveness with polyvinyl alcohol is sufficient, and has excellent polarizing plate processing suitability.
B: The film is easily peeled off from the polyvinyl alcohol and does not have appropriate polarizing plate processing suitability.
The obtained results are shown in Table 1 as polarizer adhesion.

<Evaluation of polarizing plate durability>
About the polarizing plate of each Example and comparative example produced above, the orthogonal transmittance | permeability of the polarizer in wavelength 410nm was measured by the method described in this specification.
Thereafter, the orthogonal transmittance was measured by the same method after storage for 1000 hours in an environment of 60 ° C. and 95% relative humidity. The amount of change in the orthogonal transmittance before and after aging was determined and evaluated according to the following criteria. The results are shown in Table 1 as the polarizer durability. The evaluation B or higher is allowable, but the evaluation C or lower is not allowable.
A: Change in orthogonal transmittance at wavelength 410 nm is less than 1% B: Change in orthogonal transmittance at wavelength 410 nm is 1% or more and less than 5% C: Change in orthogonal transmittance at wavelength 410 nm is 5% or more and less than 10% D: Wavelength of 410 nm Orthogonal transmittance change is 10% or more

[Production and evaluation of panels]
<Implementation to IPS panel>
A polarizing plate protective film of each example and comparative example subjected to saponification treatment in the same manner as the production of the polarizing plate of each example and comparative example except that ZRD40 (manufactured by FUJIFILM Corporation) was used instead of Fujitac TD60UL. A polarizing plate for mounting an IPS panel was produced by sandwiching the polarizer with ZRD40.
The upper and lower polarizing plates of the IPS mode liquid crystal cell (LGS 42LS5600) were peeled off, and the polarizing plate for mounting the IPS panel was attached so that the ZRD 40 was on the liquid crystal cell side. The crossed nicols were arranged so that the transmission axis of the upper polarizing plate was in the vertical direction and the transmission axis of the lower polarizing plate was in the horizontal direction. The obtained liquid crystal display device was made into the liquid crystal display device of each Example and a comparative example.

(Panel warpage after high temperature and high humidity)
After the above liquid crystal display device was allowed to pass for 72 hours at 50 ° C. and a relative humidity of 80%, the liquid crystal display device was disassembled in an environment of 25 ° C. and a relative humidity of 60%, and the amount of warping at the four corners of the panel was measured. Values are listed in Table 1.

From Table 1 above, as a result of mounting the prepared polarizing plate protective films and polarizing plates of Examples 1 to 17 on a 42-inch panel, the polarizing plate protective film of the present invention has low moisture permeability and is incorporated into the polarizing plate. It was confirmed that it has excellent polarizer adhesion and can sufficiently reduce the amount of panel warpage after aging in a high-temperature and high-humidity environment when incorporated in a liquid crystal display device.
On the other hand, the protective film for polarizing plate of Comparative Example 1 using a norbornene polymer hydride for the core layer without providing a surface layer is inferior in polarizer adhesion when incorporated in the polarizing plate, and the protective film easily peels off. Therefore, it was an insufficient result for the performance required as a polarizing plate in the present invention.
The polarizing plate protective film of Comparative Example 2 in which the thickness of the surface layer exceeds the upper limit specified in the present invention has high moisture permeability, and the amount of panel warpage after aging of the panel in a high temperature and high humidity environment when incorporated in a liquid crystal display device is reduced. Was found to be insufficient.
The polarizing plate protective film of Comparative Example 3 in which the solution viscosity of the norbornene-based polymer hydride used for the core layer exceeds the upper limit defined in the present invention is inferior in polarizer adhesion when incorporated into the polarizing plate, and the protective film is Since it peels easily, it was an inadequate result with respect to the performance calculated | required as a polarizing plate in this invention.
Since the polarizing plate protective film of Comparative Example 4 using a copolymer of styrene and acrylic for the core layer without providing a surface layer is inferior in polarizer adhesion when incorporated in the polarizing plate, the protective film easily peels off. The results required for the polarizing plate in the present invention were insufficient.
The polarizing plate protective film of Comparative Example 5 in which the solution viscosity of the copolymer of styrene and acrylic used for the core layer exceeds the upper limit specified in the present invention is inferior in polarizer adhesion when incorporated in the polarizing plate, and is a protective film. However, it was an insufficient result for the performance required as a polarizing plate in the present invention.
The polarizing plate protective film of Comparative Example 6 using acrylic that is outside the range specified in the present invention as the polymer of the core layer has high moisture permeability, and after being incorporated into a liquid crystal display device, the panel is subjected to a high temperature and high humidity environment over time. It was found that the panel warpage amount was insufficiently reduced.
Since the polarizing plate protective film of Comparative Example 7 using polystyrene that is outside the range specified in the present invention as the polymer of the core layer is inferior in polarizer adhesion when incorporated in the polarizing plate, the protective film easily peels off. The results required for the polarizing plate in the present invention were insufficient.
In addition, the polarizing plate protective film of this invention was excellent in film interface adhesiveness, and when it integrated in the polarizing plate, it existed in the tendency which was excellent in polarizer adhesiveness and polarizer durability.

1 First surface layer (air side)
2 Core layer 3 Second surface layer (support surface side)
10 Polarizing film

Claims (13)

A surface layer mainly composed of at least one cellulose acylate, and a core layer mainly composed of a polymer other than cellulose acylate,
The total film thickness of the surface layer is 0.2 to 10 μm,
The polymer that is the main component of the core layer is either a cycloolefin resin or a copolymer of styrene and acrylic,
A polymer whose solution viscosity is 10 Pa · s to 100 Pa · s when the polymer as the main component of the core layer is dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5). A polarizing plate protective film, wherein In the core layer, a compound represented by the following general formula (1),
A compound represented by the following general formula (2) and having one hydrogen-bonding donating group, or an aromatic hydrocarbon formaldehyde resin:
2. The polarizing plate protective film according to claim 1, comprising 5 to 50% by mass of at least one compound based on a polymer as a main component of the core layer.

(In general formula (1), each R independently represents a hydrogen atom, an aliphatic hydrocarbon group or an aryl group, and R may be the same or different from each other.)

(In the general formula ^{(2), R 1, R} 3 and R ⁵ are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group, or a carbon number of 2 to 20 carbon atoms Represents an aromatic group of 6 to 20.)   The compound represented by the general formula (1) is a compound having at least one phenyl group as R, a compound in which two or more Rs are bonded to each other to form a heterocyclic ring, or a novolac type phenol resin, The polarizing plate protective film according to claim 2. The polymer that is the main component of the core layer is a copolymer of styrene and acrylic,
The compound represented by the general formula (1) is contained in an amount of 5 to 50% by mass with respect to the polymer as the main component of the core layer,
The polarizing plate protective film according to claim 2 or 3, wherein the compound represented by the general formula (1) is a novolak type phenol resin.   The styrene / acrylic copolymer is a styrene / acrylic copolymer having a styrene / acrylic polymerization ratio of 2/8 to 8/2 by weight. The polarizing plate protective film according to one item. The polymer that is the main component of the core layer is a cycloolefin resin,
The compound represented by the general formula (1), the compound represented by the general formula (2) or the aromatic hydrocarbon formaldehyde resin is contained in an amount of 5 to 50% by mass with respect to the polymer as the main component of the core layer,
The compound represented by the general formula (1) is a compound having at least one phenyl group as R, or a compound in which two or more R's are bonded to each other to form a heterocyclic ring. The polarizing plate protective film of description. The polarizing plate protective film according to claim 1, wherein the polarizing plate protective film has a moisture permeability of 105 g / m ² / day or less (in terms of a film thickness of 40 μm).   The polarizing plate protective film according to claim 1, wherein the surface layer is provided on both surfaces of the core layer.   The polarizing plate protective film according to claim 1, wherein the core layer has a thickness of 20 to 60 μm.   A polarizing plate comprising a polarizer and at least one polarizing plate protective film according to claim 1.   The polarizing plate according to claim 10, wherein the polarizing plate protective film is provided only on one surface of the polarizer. A liquid crystal cell;
The polarizing plate according to claim 10 or 11 disposed in at least one of the liquid crystal cells,
A liquid crystal display device, wherein the polarizing plate protective film is arranged to be an outermost layer. Casting a surface layer dope mainly comprising at least one cellulose acylate and a core layer dope mainly containing a polymer other than cellulose acylate on a support to form a film;
Including the step of peeling the film,
The total film thickness of the surface layer is 0.2 to 10 μm,
The polymer that is the main component of the core layer dope is either a cycloolefin resin or a copolymer of styrene and acrylic,
When the polymer as the main component of the core layer dope is dissolved at a concentration of 18% by mass with respect to a dichloromethane / methanol mixed solvent (mass ratio 95/5), the solution viscosity is 10 Pa · s to 100 Pa · s. The manufacturing method of the polarizing plate protective film characterized by the above-mentioned.

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