JP2006195136A - Stacked film, and polarizing plate and liquid crystal display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film substantially having optical isotropy, and having reduced wavelength dispersion and high surface hardness. <P>SOLUTION: The stacked film is obtained by forming a layer having an ultraviolet ray absorbing function on the surface of a film satisfying inequality (1): 0≤Re(630)≤10 and ¾Rth(630)¾≤25, and inequality (II): ¾Re(400)-Re(700)¾≤10 and ¾Rth(400)-Rth(700)¾≤35; wherein Re(λ) denotes the frontal retardation value (unit: nm) in the wavelength of λnm; and Rth(λ) denotes the retardation value (unit: nm) in the film thickness direction in the wavelength of λnm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a film useful for a liquid crystal display device and a production method thereof, and further relates to an optical material such as an optical compensation film and a polarizing plate using the film and a liquid crystal display device.

  Conventionally, cellulose acylate films have been used for photographic supports and various optical materials because of their toughness and flame retardancy. In particular, in recent years, it has been widely used as an optical transparent film for liquid crystal display devices. Cellulose acylate films are excellent as optical materials for devices that handle polarized light such as liquid crystal display devices because of their high optical transparency and high optical isotropy. It has been used as a support for optical protective films that can improve (viewing angle compensation) a protective film and a display viewed from an oblique direction.

A polarizing plate, which is one of members for a liquid crystal display device, has a polarizer protective film bonded to at least one side of the polarizer. A general polarizer is obtained by dyeing a stretched polyvinyl alcohol (PVA) film with iodine or a dichroic dye.
In many cases, as a protective film for a polarizer, a cellulose acylate film, particularly a triacetyl cellulose film, which can be directly bonded to PVA is used. It is important that the polarizer protective film is excellent in optical isotropy, and the optical characteristics of the polarizer protective film greatly affect the characteristics of the polarizing plate.

  In recent liquid crystal display devices, improvement in viewing angle characteristics is strongly demanded, and optical transparent films such as a protective film for a polarizer and a support for an optical compensation film are more optically isotropic. It is required to be sex. In order to be optically isotropic, it is important that the retardation value represented by the product of birefringence and thickness of the optical film is small. In particular, in order to improve display from an oblique direction, it is necessary to reduce not only the retardation (Re) in the front direction but also the retardation (Rth) in the film thickness direction. Specifically, when the optical properties of the optical transparent film are evaluated, the Re measured from the front of the film is small, and it is required that the Re does not change even if the angle is changed.

  So far, there has been a cellulose acylate film with a small Re on the front, but it was difficult to produce a cellulose acylate film with a small Re change with angle, that is, a small Rth.

  In the production of a cellulose acylate film, a compound called a plasticizer is generally added to improve the film forming performance. As types of plasticizers, phosphate triesters such as triphenyl phosphate and biphenyl diphenyl phosphate, phthalates, and the like are disclosed (for example, see Non-Patent Document 1). Among these plasticizers, those having an effect of reducing the optical anisotropy of the cellulose acylate film are known. For example, specific fatty acid esters are disclosed (for example, see Patent Document 1). ). However, the effect of reducing the optical anisotropy of cellulose acylate films using these conventionally known compounds is not sufficient.

  Furthermore, when these films are used as protective films for polarizing plates, there are problems that the optical properties and physical properties of the films are deteriorated or colored due to ultraviolet rays, sunlight, or backlights of liquid crystal display devices. In addition, the cellulose acylate film has a low surface hardness and has a problem of being scratched during handling.

Also, recent liquid crystal display devices are required to improve display color. Therefore, an optical transparent film such as a protective film for a polarizer or a support for an optical compensation film not only reduces Re and Rth in the visible region of a wavelength of 400 to 800 nm, but also changes Re and Rth depending on the wavelength, that is, wavelength dispersion. It needs to be small.
JP 2001-247717 A Plastic Materials Course, Volume 17, Nikkan Kogyo Shimbun, “Fiber-Based Resin”, p. 121 (Showa 45)

The first object of the present invention is cellulose having a small optical anisotropy (Re, Rth) and substantially optical isotropy, and further having a small wavelength dispersion of the optical anisotropy (Re, Rth). It is to provide an acylate film.
The second object of the present invention is to provide a cellulose acylate film having excellent light resistance.
The third object of the present invention is to provide a cellulose acylate film having excellent surface hardness.
A fourth object of the present invention is to provide an optical material excellent in optical characteristics such as viewing angle characteristics, and to provide a liquid crystal display device using them.

As a result of intensive studies, the inventors of the present invention have formed a film using a material having a small optical anisotropy and a small wavelength dispersion, and further provided a layer having an ultraviolet absorption function on the surface thereof, thereby I found that the problem could be solved. Based on this discovery, the present invention having the following configuration is provided.
[1] A laminated film in which a layer having an ultraviolet absorbing function is formed on the surface of a film satisfying the following formulas (I) and (II) (hereinafter also referred to as a base film).
Formula (I): 0 ≦ Re (630) ≦ 10 and | Rth (630) | ≦ 25
Formula (II): | Re (400) −Re (700) | ≦ 10 and | Rth (400) −Rth (700) | ≦ 35
[In the formula, Re (λ) is a front retardation value (unit: nm) at a wavelength λnm, and Rth (λ) is a retardation value (unit: nm) in a film thickness direction at a wavelength λnm. ]
[2] The laminated film according to [1], wherein the layer having an ultraviolet absorbing function is made of a material obtained by curing a mixture of an ultraviolet absorber, an active energy ray curable resin, and a polymerization initiator with an active energy ray.
[3] The film is a cellulose acylate film having an acyl substitution degree of 2.85 to 3.00, and at least one compound that reduces the optical anisotropy of the film is a solid content of cellulose acylate. The laminated film according to [1] or [2], which is contained in an amount of 0.01 to 30% by weight.
[4] The laminated film according to any one of [1] to [3], wherein the film has a thickness of 10 to 120 μm.
[5] A polarizing plate formed by forming the laminated film according to any one of [1] to [4] on at least one surface of a polarizer.
[6] A liquid crystal display device having the polarizing plate according to [5].

  The laminated film of the present invention is characterized by small optical anisotropy (Re, Rth), substantially optical isotropy, and small wavelength dispersion. Moreover, the laminated film of the present invention is excellent in light resistance, and the surface hardness can be improved. Such a laminated film is useful as an optical film excellent in optical characteristics such as viewing angle characteristics, and can be used as a protective film for polarizing plates, a support for optical compensation films, and the like. Furthermore, if these optical films are used, a liquid crystal display device having an excellent function can be provided.

  Hereinafter, the laminated film and the like of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, 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.

The laminated film of the present invention has a structure in which a layer having an ultraviolet absorbing function is formed on the surface of a base film.
The base film used in the present invention is a film having a small optical anisotropy that satisfies the above formula (I). That is, the in-plane retardation Re (630) at a wavelength of 630 nm is 10 nm or less (0 ≦ Re (630) ≦ 10), and the absolute value of the retardation Rth (630) in the film thickness direction is 25 nm or less (| Rth | ≦ 25 nm). Preferably, 0 ≦ Re (630) ≦ 5 and | Rth | ≦ 20 nm, and particularly preferably 0 ≦ Re (630) ≦ 2 and | Rth | ≦ 15 nm.
The base film used in the present invention is a film having a small wavelength dispersion that satisfies the above formula (II). That is, | Re (400) −Re (700) | ≦ 10 and | Rth (400) −Rth (700) | ≦ 35. Preferably, | Re (400) −Re (700) | ≦ 5 and | Rth (400) −Rth (700) | ≦ 25, and particularly preferably | Re (400) −Re (700) | ≦ 3. And | Rth (400) −Rth (700) | ≦ 15.

  In this specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at a wavelength λ, respectively. Re (λ) is measured in KOBRA 21ADH (manufactured by Oji Scientific Instruments) by making light having a wavelength of λ nm incident in the normal direction of the film. Rth (λ) is the light of wavelength λnm from the direction inclined by + 40 ° with respect to the normal direction of the film, with Re (λ) and the in-plane slow axis (determined by KOBRA 21ADH) as the tilt axis (rotation axis) And a retardation value measured by making light of wavelength λ nm incident from a direction inclined by −40 ° with respect to the film normal direction with the in-plane slow axis as the tilt axis (rotation axis). KOBRA 21ADH calculates based on the retardation value measured in three directions, the assumed value of the average refractive index, and the input film thickness value. Here, as the assumed value of the average refractive index, the values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). KOBRA 21ADH calculates nx, ny, and nz by inputting these assumed values of average refractive index and film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

Film satisfying formulas (I) and (II) The type of film satisfying formulas (I) and (II) used in the present invention and the method for adjusting the retardation are not particularly limited. For example, it is possible to use a cellulose acylate film, a polycarbonate film, and a thermoplastic cycloolefin film. Specifically, the films described in JP-A Nos. 2001-318233 and 2002-328233, ZEONOR (manufactured by ZEON Corporation), ARTON (manufactured by JSR Corporation) or the like can be used. A cellulose acylate film is particularly preferable. Therefore, the cellulose acylate film will be specifically described below as an example.

[Cellulose acylate]
(Raw cotton)
Cellulose acylate raw material cellulose used in the present invention includes cotton linter and wood pulp (hardwood pulp, softwood pulp) and the like, and any cellulose acylate obtained from any raw material cellulose can be used, optionally mixed. May be. Detailed descriptions of these raw material celluloses can be found in, for example, Plastic Materials Course (17) Fibrous Resin (Maruzawa, Uda, Nikkan Kogyo Shimbun, published in 1970) and Invention Association Open Technical Report 2001-1745 (page 7). To page 8) can be used, and the present invention is not particularly limited to the laminated film of the present invention.

(Degree of substitution)
Next, the cellulose acylate produced from the above cellulose will be described. Cellulose acylate is obtained by acylating a hydroxyl group of cellulose, and the substituent can be any acetyl group having 2 carbon atoms in the acyl group to those having 22 carbon atoms. In the cellulose acylate of the present invention, the degree of substitution of cellulose with a hydroxyl group is not particularly limited, but the degree of binding of acetic acid and / or a fatty acid having 3 to 22 carbon atoms substituted with a hydroxyl group of cellulose is measured and substituted by calculation. You can get a degree. The measurement can be carried out according to ASTM D-817-91 (the degree of substitution when the hydroxyl group is substituted by 100% is 3).

  As described above, in the cellulose acylate used in the present invention, the degree of substitution of cellulose with a hydroxyl group is not particularly limited, but the degree of acyl substitution with a hydroxyl group of cellulose is preferably 2.50 to 3.00. Furthermore, the substitution degree is more preferably 2.75 to 3.00, and further preferably 2.85 to 3.00.

  Among the acetic acid substituted for the hydroxyl group of cellulose and / or the fatty acid having 3 to 22 carbon atoms, the acyl group having 2 to 22 carbon atoms may be an aliphatic group or an allyl group, and is not particularly limited. A mixture of the above may also be used. These are, for example, cellulose alkylcarbonyl esters, alkenylcarbonyl esters, aromatic carbonyl esters, aromatic alkylcarbonyl esters, and the like, each of which may further have a substituted group. As these preferable acyl groups, acetyl group, propionyl group, butanoyl group, heptanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, octadecanoyl group , Iso-butanoyl group, tert-butanoyl group, cyclohexanecarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like. Among these, acetyl group, propionyl group, butanoyl group, dodecanoyl group, octadecanoyl group, tert-butanoyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group and the like are preferable, and acetyl group, propionyl group, butanoyl group are preferable. Groups are more preferred.

  As a result of intensive studies by the inventor of the present invention, when the acyl group that substitutes the hydroxyl group of the cellulose is substantially composed of two or more types selected from acetyl group / propionyl group / butanoyl group, the total substitution degree It was found that the optical anisotropy of the cellulose acylate film was reduced when the value was 2.50 to 3.00. The degree of acyl substitution is more preferably 2.60 to 3.00, still more preferably 2.65 to 3.00.

(Degree of polymerization)
The degree of polymerization of the cellulose acylate preferably used in the present invention is 180 to 700 as an average degree of polymerization. In the cellulose acetate, 180 to 550 is more preferable, 180 to 400 is more preferable, and 180 to 350 is particularly preferable. If the degree of polymerization is too high, the viscosity of the cellulose acylate dope solution becomes high, and film production becomes difficult due to casting. If the degree of polymerization is too low, the strength of the produced film will decrease. The average degree of polymerization can be measured by Uda et al.'S intrinsic viscosity method (Kazuo Uda, Hideo Saito, Journal of Textile Society, Vol. This is described in detail in JP-A-9-95538.
The molecular weight distribution of cellulose acylate preferably used in the present invention is evaluated by gel permeation chromatography, and its polydispersity index Mw / Mn (Mw is a mass average molecular weight, Mn is a number average molecular weight) is small, and the molecular weight distribution. Is preferably narrow. The specific value of Mw / Mn is preferably 1.0 to 3.0, more preferably 1.0 to 2.0, and most preferably 1.0 to 1.6. preferable.

  When the low molecular component is removed, the average molecular weight (degree of polymerization) increases, but the viscosity becomes lower than that of normal cellulose acylate, which is useful. Cellulose acylate having a small amount of low molecular components can be obtained by removing low molecular components from cellulose acylate synthesized by a usual method. The removal of the low molecular component can be carried out by washing the cellulose acylate with an appropriate organic solvent. In addition, when manufacturing a cellulose acylate with few low molecular components, it is preferable to adjust the sulfuric acid catalyst amount in an acetylation reaction to 0.5-25 mass parts with respect to 100 mass parts of cellulose. When the amount of the sulfuric acid catalyst is within the above range, cellulose acylate that is preferable in terms of molecular weight distribution (uniform molecular weight distribution) can be synthesized. In the present invention, when used for producing cellulose acylate, the water content is preferably 2% by mass or less, more preferably 1% by mass or less, and particularly 0.7% by mass or less. In general, cellulose acylate contains water and is known to have a water content of 2.5 to 5% by mass. In order to make the moisture content of a cellulose acylate 2 mass% or less, it is necessary to dry, and the method will not be specifically limited if it becomes the target moisture content. These cellulose acylates of the present invention are described in detail on pages 7 to 12 of the raw material cotton and the synthesis method of the Japan Society for Invention and Technology (Public Technical Number 2001-1745, published on March 15, 2001, Japan Society for Invention). Has been.

  The cellulose acylate of the present invention may be used singly or as a mixture of two or more kinds of cellulose acylates as long as the substituent, substitution degree, polymerization degree, molecular weight distribution and the like are within the above-mentioned ranges.

[Additive to cellulose acylate]
A film satisfying the formulas (I) and (II) can be produced by appropriately adding an additive to the cellulose acylate. That is, for cellulose acylate, various additives according to the use in each preparation step (for example, compounds that reduce optical anisotropy, wavelength dispersion regulators, ultraviolet inhibitors, plasticizers, deterioration inhibitors, fine particles , Optical property adjusting agents, etc.) can be added. For example, using a compound that suppresses in-plane and film thickness orientation of cellulose acylate in the film, the optical anisotropy is sufficiently reduced and adjusted so that Re is zero and Rth is close to zero. can do. Further, by using a compound that suppresses retardation wavelength dispersion, | Re (400) −Re (700) | and | Rth (400) −Rth (700) | can be adjusted to be small.
There is no particular limitation on the timing of addition of the additive. You may add at the time of dope adjustment, and may add at the end of the dope preparation process.
Hereinafter, additives that can be preferably used in the present invention will be described.

(Compound that reduces the optical anisotropy of cellulose acylate film)
A compound that reduces the optical anisotropy of the cellulose acylate film can be preferably added to the cellulose acylate. In particular, it is preferable to add at least one compound that lowers the retardation (Rth) in the film thickness direction within a range that satisfies the following formulas (i) and (ii).
Formula (i): (Rth [A] −Rth [0]) / A ≦ −1.0
Formula (ii): 0.01 ≦ A ≦ 30
The above formulas (i) and (ii) are represented by the formula (i-1): (Rth [A] −Rth [0]) / A ≦ −2.0
Formula (ii-1): 0.05 ≦ A ≦ 25
More preferably,
Formula (i-2): (Rth [A] −Rth [0]) / A ≦ −3.0
Formula (ii-2): 0.1 ≦ A ≦ 20
More preferably.
In the above formula, Rth [A], Rth [0], and A are respectively defined as follows.
Rth (A): Rth of a film containing A% of a compound that lowers Rth
(Unit: nm)
Rth (0): Rth of a film containing no compound that lowers Rth
(Unit: nm)
A: Rth is reduced when the weight of the film raw material polymer is 100
Weight of compound to be made (unit%)

  The compound that reduces the optical anisotropy has the effect of suppressing the in-plane and film thickness orientation of the cellulose acylate in the film and sufficiently reduces the optical anisotropy of the film. , Re can be zero and Rth can be close to zero. The compound that lowers the optical anisotropy is sufficiently compatible with cellulose acylate, and it is advantageous that the compound itself does not have a rod-like structure or a planar structure. Specifically, when a plurality of planar functional groups such as aromatic groups are provided, a structure having these functional groups in a non-planar rather than the same plane is advantageous.

The compound that reduces optical anisotropy may or may not contain an aromatic group. Further, the compound that reduces the optical anisotropy preferably has a molecular weight of 150 to 3000, more preferably 170 to 2000, and particularly preferably 200 to 1000. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used.
The compound that reduces optical anisotropy is preferably a liquid at 25 ° C. or a solid having a melting point of 25 to 250 ° C., more preferably a liquid at 25 ° C. or a melting point of 25 to 200 ° C. It is a solid. Moreover, it is preferable that the compound which reduces optical anisotropy does not volatilize in the process of dope casting for cellulose acylate film production and drying.
The addition amount of the compound that decreases the optical anisotropy is preferably 0.01 to 30% by mass of the cellulose acylate, more preferably 1 to 25% by mass, and 5 to 20% by mass. Is particularly preferred.
The compound that decreases the optical anisotropy may be used alone, or two or more compounds may be mixed and used in an arbitrary ratio.
The timing for adding the compound for reducing the optical anisotropy may be any time during the dope preparation process, or may be performed at the end of the dope preparation process.

  The compound that reduces the optical anisotropy is such that the average content of the compound in the portion from the surface on at least one side to 10% of the total film thickness is the average content of the compound in the central portion of the cellulose acylate film. It is preferable to use so that it may become 80 to 99% of. The abundance of the compound can be determined by measuring the amount of the compound at the surface and in the central portion, for example, by a method using an infrared absorption spectrum described in JP-A-8-57879.

As the compound for reducing the optical anisotropy, a sulfonamide and a carbonamide represented by the following general formula (1) are preferably used.

In the general formula (1), Z represents —SO ₂ — or —CO—. R ¹ represents an alkyl group or an aryl group, and R ² and R ³ each independently represent a hydrogen atom, an alkyl group or an aryl group. Further, the total number of carbon atoms of R ¹ , R ² and R ³ is particularly preferably 10 or more. As the substituent, a fluorine atom, an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are preferable, and an alkyl group, an aryl group, an alkoxy group, a sulfone group, and a sulfonamide group are particularly preferable. Further, the alkyl group may be linear, branched or cyclic, and preferably has 1 to 25 carbon atoms, more preferably 6 to 25, and more preferably 6 to 20 (For example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, isoamyl, t-amyl, hexyl, cyclohexyl, heptyl, octyl, bicyclo Octyl, nonyl, adamantyl, decyl, t-octyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, didecyl) are particularly preferred . As the aryl group, those having 6 to 30 carbon atoms are preferable, and those having 6 to 24 carbon atoms (for example, phenyl group, biphenyl group, terphenyl group, naphthyl group, binaphthyl group, triphenylphenyl group) are particularly preferable.
Although the preferable example of a compound represented by General formula (1) is shown below, the compound which reduces the optical anisotropy which can be used by this invention is not limited to these specific examples.

(Wavelength dispersion adjusting agent)
A compound (also referred to as a wavelength dispersion adjusting agent) that reduces the wavelength dispersion of the cellulose acylate film will be described.
In order to improve the wavelength dispersion of Rth of the cellulose acylate film, a compound that decreases the wavelength dispersion of Rth represented by the following formula (iii) is at least within a range satisfying the following formulas (iv) and (v): It is preferable to contain 1 type.
Formula (iii): ΔRth = | Rth (400) −Rth (700) |
Formula (iv): (ΔRth (B) −ΔRth (0)) / B ≦ −2.0
Formula (v): 0.01 ≦ B ≦ 30
The above formulas (iv) and (v) are represented by formula (iv-1): (ΔRth (B) −ΔRth (0)) / B ≦ −3.0
Formula (v-1): 0.05 ≦ B ≦ 25
More preferably,
Formula (iv-2): (ΔRth (B) −ΔRth (0)) / B ≦ −4.0
Formula (v-2): 0.1 ≦ B ≦ 20
More preferably.

  At least one compound having absorption in the ultraviolet region of 200 to 400 nm and lowering | Re (400) -Re (700) | and | Rth (400) -Rth (700) | It is preferable to contain 0.01-30 weight% with respect to a minute.

  In general, the Re and Rth values of the cellulose acylate film have a wavelength dispersion characteristic that the longer wavelength side is larger than the shorter wavelength side. Therefore, it is required to smooth the chromatic dispersion by increasing Re and Rth on the relatively short wavelength side. On the other hand, a compound having absorption in the ultraviolet region of 200 to 400 nm has a wavelength dispersion characteristic in which the absorbance on the long wavelength side is larger than that on the short wavelength side. If the compound itself is isotropically present inside the cellulose acylate film, it is assumed that the birefringence of the compound itself, and thus the wavelength dispersion of Re and Rth, is large on the short wavelength side as well as the wavelength dispersion of absorbance. .

  Therefore, as described above, by using the compound having absorption in the ultraviolet region of 200 to 400 nm and assuming that the wavelength dispersion of Re and Rth of the compound itself is large on the short wavelength side, the Re and Rth of the cellulose acylate film are used. Chromatic dispersion can be prepared. For this purpose, the compound for adjusting the wavelength dispersion is required to be sufficiently homogeneously compatible with the cellulose acylate. The absorption band range in the ultraviolet region of such a compound is preferably 200 to 400 nm, more preferably 220 to 395 nm, and even more preferably 240 to 390 nm.

  In recent years, liquid crystal display devices such as televisions, notebook personal computers, and mobile portable terminals have been required to have excellent transmittance of optical members used in liquid crystal display devices in order to increase luminance with less power. In that respect, a cellulose acylate film is a compound having absorption in the ultraviolet region of 200 to 400 nm and reducing | Re (400) -Re (700) | and | Rth (400) -Rth (700) | When it is added, it is required to have excellent spectral transmittance. In the cellulose acylate film of the present invention, the spectral transmittance at a wavelength of 380 nm is preferably 45% to 95%, and the spectral transmittance at a wavelength of 350 nm is preferably 10%.

As described above, the wavelength dispersion adjusting agent preferably used in the present invention preferably has a molecular weight of 250 to 1000 from the viewpoint of volatility. More preferably, it is 260-800, More preferably, it is 270-800, Most preferably, it is 300-800. A specific monomer structure may be used as long as these molecular weights are within the range, and an oligomer structure or a polymer structure in which a plurality of the monomer units are bonded may be used.
It is preferable that the wavelength dispersion adjusting agent does not volatilize during the dope casting and drying process for producing the cellulose acylate film.

The addition amount of the wavelength dispersion adjusting agent preferably used in the present invention described above is preferably 0.01 to 30% by weight, more preferably 0.1 to 20% by weight of cellulose acylate, and 2 to 10% by weight is particularly preferred.
These wavelength dispersion adjusting agents may be used alone or in combination of two or more compounds at an arbitrary ratio.
Further, the timing of adding these wavelength dispersion adjusting agents may be any time during the dope preparation process, or may be performed at the end of the dope preparation process.

  Specific examples of the wavelength dispersion adjusting agent preferably used in the present invention include, for example, benzotriazole compounds, benzophenone compounds, compounds containing a cyano group, oxybenzophenone compounds, salicylic acid ester compounds, nickel complex compounds, and the like. However, it is not limited to these.

As the benzotriazole-based compound, those represented by the general formula (101) are preferably used as the wavelength dispersion adjusting agent of the present invention.
Formula ^{(101): Q 1 -Q 2} -OH
(In the formula, Q ¹ represents a nitrogen-containing aromatic heterocycle, and Q ² represents an aromatic ring.)

Q ¹ represents a nitrogen-containing aromatic heterocycle, preferably a 5- to 7-membered nitrogen-containing aromatic heterocycle, more preferably a 5- to 6-membered nitrogen-containing aromatic heterocycle, such as imidazole Ring, pyrazole ring, triazole ring, tetrazole ring, thiazole ring, oxazole ring, selenazole ring, benzotriazole ring, benzothiazole ring, benzoxazole ring, benzoselenazole ring, thiadiazole ring, oxadiazole ring, naphthothiazole ring, naphtho An oxazole ring, an azabenzimidazole ring, a purine ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, a triazine ring, a triazaindene ring, a tetrazaindene ring, and the like, more preferably a 5-membered nitrogen-containing aromatic A heterocyclic ring, specifically an imidazole ring, a pyrazole ring, Riazor ring, tetrazole ring, thiazole ring, oxazole ring, benzotriazole ring, benzothiazole ring, benzoxazole ring, thiadiazole ring, oxadiazole ring are preferred, particularly preferably a benzotriazole ring.
The nitrogen-containing aromatic heterocycle represented by Q ¹ may further have a substituent, and the substituent T described below can be applied as the substituent. In addition, when there are a plurality of substituents, each may be condensed to form a ring.

The aromatic ring represented by Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.
The aromatic hydrocarbon ring is preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, a benzene ring or a naphthalene ring), and more preferably an aromatic hydrocarbon having 6 to 20 carbon atoms. A ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms. More preferred is a benzene ring.
The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the hetero ring include, for example, thiophene ring, imidazole ring, pyrazole ring, pyridine ring, pyrazine ring, pyridazine ring, triazole ring, triazine ring, indole ring, indazole ring, purine ring, thiazoline ring, thiazole ring, thiadiazole. Ring, oxazoline ring, oxazole ring, oxadiazole ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinazoline ring, cinnoline ring, pteridine ring, acridine ring, phenanthroline ring, phenazine ring, tetrazole ring, benz Examples include an imidazole ring, a benzoxazole ring, a benzthiazole ring, a benzotriazole ring, and a tetrazaindene ring. The aromatic hetero ring is preferably a pyridine ring, a triazine ring or a quinoline ring.
The aromatic ring represented by Q ² is preferably an aromatic hydrocarbon ring, more preferably a naphthalene ring or a benzene ring, and particularly preferably a benzene ring. Q ² may further have a substituent, and the substituent T is preferred.

  Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as a methyl group, an ethyl group, an iso-propyl group, a tert group, and the like. -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 carbon 2 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 having 2 to 20 carbon atoms, More preferably, it 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. Ru group (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). A substituted or unsubstituted amino group (preferably having 0 to 20 carbon atoms, more preferably 0 to 10 carbon atoms, particularly preferably 0 to 6 carbon atoms, such as an amino group, methylamino, dimethylamino group, diethylamino group, A dibenzylamino group, etc.), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms, particularly preferably 1 to 8 carbon atoms, such as methoxy group, ethoxy group, butoxy Group), an aryloxy group (preferably having 6 to 20 carbon atoms, more preferably 6 to 16 carbon atoms, and particularly preferably 6 to 12 carbon atoms). For example, a phenyloxy group, 2-naphthyloxy group, etc.), an acyl group (preferably having 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, particularly preferably 1 to 12 carbon atoms, For example, an acetyl group, a benzoyl group, a formyl group, a pivaloyl group, etc.), an alkoxycarbonyl group (preferably having 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, and particularly preferably 2 to 12 carbon atoms). A methoxycarbonyl group, an ethoxycarbonyl group, etc.), an aryloxycarbonyl group (preferably having a carbon number of 7-20, more preferably having a carbon number of 7-16, particularly preferably having a carbon number of 7-10, Phenyloxycarbonyl group, etc.), acyloxy group (preferably having 2 to 20 carbon atoms, more preferably It has 2 to 16 carbon atoms, particularly preferably 2 to 10 carbon atoms, and examples thereof include an acetoxy group and a benzoyloxy group. ), 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). These substituents may be further substituted. 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.

What is preferable as the compound represented by the general formula (101) is a compound represented by the following general formula (101-A).
General formula (101-A)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent a hydrogen atom or a substituent, and the above-mentioned substituent T can be applied as the substituent. . These substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.
R ¹ and R ³ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably an alkyl group having 1 to 12 carbon atoms (preferably 4 to 12 carbon atoms).

R ² and R ⁴ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom and a methyl group, most preferably It is a hydrogen atom.

R ⁵ and R ⁸ are preferably hydrogen atoms, alkyl groups, alkenyl groups, alkynyl groups, aryl groups, substituted or unsubstituted amino groups, alkoxy groups, aryloxy groups, hydroxy groups, and halogen atoms, more preferably hydrogen atoms. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and an alkyl group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom and a methyl group, most preferably It is a hydrogen atom.

R ⁶ and R ⁷ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom. An atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, more preferably a hydrogen atom and a halogen atom, and particularly preferably a hydrogen atom and a chlorine atom.

  Among the benzotriazole compounds exemplified in the above examples, it was confirmed that when a cellulose acylate film was produced without including those having a molecular weight of 320 or less, it was advantageous in terms of retention.

（式中、Ｑ¹およびＱ²はそれぞれ独立に芳香族環を表す。ＸはＮＲ（Ｒは水素原子または置換基を表す。）、酸素原子または硫黄原子を表す。） In addition, as the benzophenone compound which is one of the wavelength dispersion adjusting agents used in the present invention, those represented by the general formula (102) are preferably used.
Formula (102)

(In the formula, Q ¹ and Q ² each independently represent an aromatic ring. X represents NR (R represents a hydrogen atom or a substituent), an oxygen atom or a sulfur atom.)

The aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic heterocycle. These may be monocyclic or may form a condensed ring with another ring.
The aromatic hydrocarbon ring represented by Q ¹ and Q ² is preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, a benzene ring, a naphthalene ring, etc.). More preferably, it is a C6-C20 aromatic hydrocarbon ring, More preferably, it is a C6-C12 aromatic hydrocarbon ring. More preferred is a benzene ring.
The aromatic heterocycle represented by Q ¹ and Q ² is preferably an aromatic heterocycle containing at least one of an oxygen atom, a nitrogen atom or a sulfur atom. Specific examples of the hetero ring include a ring such as a ring, furan ring, pyrrole ring, thiophene ring, imidazole ring, pyrazole ring, pyridine ring, pyrazine ring, pyridazine ring, triazole ring, triazine ring, indole ring, indazole ring, and purine ring. , Thiazoline ring, thiazole ring, thiadiazole ring, oxazoline ring, oxazole ring, oxadiazole ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinazoline ring, cinnoline ring, pteridine ring, acridine ring, phenanthroline ring Phenazine ring, tetrazole ring, benzimidazole ring, benzoxazole ring, benzthiazole ring, benzotriazole ring, tetrazaindene ring and the like. The aromatic hetero ring is preferably a ring, a pyridine ring, a triazine ring, or a quinoline ring.
The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring and a ring, more preferably an aromatic hydrocarbon ring having 6 to 10 carbon atoms, and further preferably a substituted or unsubstituted benzene ring. It is.
Q ¹ and Q ² may further have a substituent, and the substituent T described later is preferable, but the substituent does not contain a carboxylic acid, a sulfonic acid, or a quaternary ammonium salt. Further, if possible, substituents may be linked to form a ring structure.

  X represents NR (R represents a hydrogen atom or a substituent. Substituent T described later can be applied as the substituent), an oxygen atom or a sulfur atom, and X is preferably NR (R is preferably an acyl group) , A sulfonyl group, and these substituents may be further substituted.) Or O, particularly preferably O.

  Specific examples and preferred ranges of the substituent T are as described above.

A preferable compound represented by the general formula (102) is a compound represented by the following general formula (102-A).
Formula (102-A)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represent a hydrogen atom or a substituent, and the above-mentioned substituent T can be applied as the substituent. . These substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.

R ¹ , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁸ and R ⁹ are preferably a hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, substituted or unsubstituted amino group, alkoxy group, aryl An oxy group, a hydroxy group and a halogen atom, more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group and a halogen atom, still more preferably a hydrogen atom and a carbon 1-12 alkyl group. Particularly preferred are a hydrogen atom and a methyl group, and most preferred is a hydrogen atom.

R ² is preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, a halogen atom, more preferably a hydrogen atom or one carbon atom. An alkyl group having -20 carbon atoms, an amino group having 0-20 carbon atoms, an alkoxy group having 1-12 carbon atoms, an aryloxy group having 6-12 carbon atoms, and a hydroxy group, and more preferably an alkoxy group having 1-20 carbon atoms. And particularly preferably an alkoxy group having 1 to 12 carbon atoms.

R ⁷ is preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, an alkoxy group, an aryloxy group, a hydroxy group, a halogen atom, more preferably a hydrogen atom or one carbon atom. An alkyl group having -20 carbon atoms, an amino group having 0-20 carbon atoms, an alkoxy group having 1-12 carbon atoms, an aryloxy group having 6-12 carbon atoms, and a hydroxy group, more preferably a hydrogen atom, having 1-20 carbon atoms. An alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, still more preferably a methyl group), particularly preferably a methyl group or a hydrogen atom.

（式中、Ｑ¹およびＱ²はそれぞれ独立に芳香族環を表す。Ｘ¹およびＸ²は水素原子または置換基を表し、少なくともどちらか１つはシアノ基、カルボニル基、スルホニル基、芳香族ヘテロ環を表す。Ｑ¹およびＱ²で表わされる芳香族環は芳香族炭化水素環でも芳香族ヘテロ環でもよい。また、これらは単環であってもよいし、さらに他の環と縮合環を形成してもよい。） As the compound containing a cyano group, which is one of the wavelength dispersion adjusting agents used in the present invention, those represented by the general formula (103) are preferably used.
General formula (103)

(In the formula, Q ¹ and Q ² each independently represent an aromatic ring. X ¹ and X ² represent a hydrogen atom or a substituent, and at least one of them represents a cyano group, a carbonyl group, a sulfonyl group, an aromatic group. The aromatic ring represented by Q ¹ and Q ² may be an aromatic hydrocarbon ring or an aromatic hetero ring, which may be a single ring or a condensed ring with another ring. May be formed.)

  The aromatic hydrocarbon ring is preferably a monocyclic or bicyclic aromatic hydrocarbon ring having 6 to 30 carbon atoms (for example, a benzene ring or a naphthalene ring), and more preferably an aromatic hydrocarbon having 6 to 20 carbon atoms. A ring, more preferably an aromatic hydrocarbon ring having 6 to 12 carbon atoms. More preferred is a benzene ring.

The aromatic heterocycle is preferably an aromatic heterocycle containing a nitrogen atom or a sulfur atom. Specific examples of the hetero ring include, for example, thiophene ring, imidazole ring, pyrazole ring, pyridine ring, pyrazine ring, pyridazine ring, triazole ring, triazine ring, indole ring, indazole ring, purine ring, thiazoline ring, thiazole ring, thiadiazole. Ring, oxazoline ring, oxazole ring, oxadiazole ring, quinoline ring, isoquinoline ring, phthalazine ring, naphthyridine ring, quinoxaline ring, quinazoline ring, cinnoline ring, pteridine ring, acridine ring, phenanthroline ring, phenazine ring, tetrazole ring, benz an imidazole ring, a benzoxazole ring, benzthiazole ring, benzotriazole ring, an aromatic ring are exemplified represented by tetrazaindene Q ^2. Preferably aromatic heterocycle, a pyridine ring, a triazine ring, an aromatic ring represented by quinoline Q ^2.

The aromatic ring represented by Q ¹ and Q ² is preferably an aromatic hydrocarbon ring, and more preferably a benzene ring.
Q ¹ and Q ² may further have a substituent, and the substituent T is preferable as the substituent. Specific examples and preferred ranges of the substituent T are as described above.

X ¹ and X ² each represent a hydrogen atom or a substituent, and at least one of them represents a cyano group, a carbonyl group, a sulfonyl group, or an aromatic heterocycle. The substituent T described above can be applied to the substituents represented by X ¹ and X ² . In addition, the substituent represented by X ¹ and X ² may be further substituted with another substituent, and X ¹ and X ² may be condensed to form a ring structure.

X ¹ and X ² are preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group, or an aromatic heterocycle, and more preferably a cyano group, a carbonyl group, a sulfonyl group, An aromatic heterocycle, more preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, 6 carbon atoms). ˜12 aryl groups and combinations thereof.

（式中、Ｒ¹、Ｒ²、Ｒ³、Ｒ⁴、Ｒ⁵、Ｒ⁶、Ｒ⁷、Ｒ⁸、Ｒ⁹およびＲ¹⁰はそれぞれ独立に水素原子または置換基を表す。Ｘ¹およびＸ²は一般式（１０３）におけるそれらと同義であり、また好ましい範囲も同様である。） As the general formula (103), a compound represented by the following general formula (103-A) is preferable.
General formula (103-A)

(Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represents a hydrogen atom or a substituent. X ¹ and X ² Are the same as those in formula (103), and the preferred range is also the same.)

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ each independently represent a hydrogen atom or a substituent, and examples of the substituent include the substituents described above. T is applicable. These substituents may be further substituted with another substituent, and the substituents may be condensed to form a ring structure.

R ¹ , R ² , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁹ , and R ¹⁰ are preferably a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a substituted or unsubstituted amino group, An alkoxy group, an aryloxy group, a hydroxy group, and a halogen atom, more preferably a hydrogen atom, an alkyl group, an aryl group, an alkyloxy group, an aryloxy group, and a halogen atom, still more preferably a hydrogen atom and carbon 1-12. An alkyl group, particularly preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

R ³ and R ⁸ are preferably a hydrogen atom, alkyl group, alkenyl group, alkynyl group, aryl group, substituted or unsubstituted amino group, alkoxy group, aryloxy group, hydroxy group, halogen atom, more preferably a hydrogen atom, An alkyl group having 1 to 20 carbon atoms, an amino group having 0 to 20 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, and a hydroxy group, more preferably a hydrogen atom and 1 carbon atom. An alkyl group having 12 to 12 carbon atoms and an alkoxy group having 1 to 12 carbon atoms, particularly preferably a hydrogen atom.

（式中、Ｒ³およびＲ⁸は一般式（１０３−Ａ）におけるそれらと同義であり、また、好
ましい範囲も同様である。Ｘ³は水素原子、または置換基を表す。） More preferable as the general formula (103) is a compound represented by the following general formula (103-B).
General formula (103-B)

(Wherein R ³ and R ⁸ have the same meanings as those in formula (103-A), and preferred ranges are also the same. X ³ represents a hydrogen atom or a substituent.)

X ³ represents a hydrogen atom or a substituent. As the substituent, the above-described substituent T can be applied, and if possible, the substituent may be further substituted with another substituent. X ³ is preferably a hydrogen atom, an alkyl group, an aryl group, a cyano group, a nitro group, a carbonyl group, a sulfonyl group or an aromatic heterocyclic ring, more preferably a cyano group, a carbonyl group, a sulfonyl group or an aromatic heterocyclic ring. More preferably a cyano group or a carbonyl group, and particularly preferably a cyano group or an alkoxycarbonyl group (—C (═O) OR (R is an alkyl group having 1 to 20 carbon atoms, an aryl having 6 to 12 carbon atoms). Group and a combination thereof).

（式中、Ｒ³およびＲ⁸は一般式（１０３−Ａ）におけるそれらと同義であり、また、好
ましい範囲も同様である。Ｒ²¹は炭素数１〜２０のアルキル基を表す。） More preferred as the general formula (103) is a compound represented by the general formula (103-C).
General formula (103-C)

(Wherein R ³ and R ⁸ have the same meanings as those in formula (103-A), and the preferred ranges are also the same. R ²¹ represents an alkyl group having 1 to 20 carbon atoms.)

R ²¹ is preferably an alkyl group having 2 to 12 carbon atoms, more preferably an alkyl group having 4 to 12 carbon atoms, and still more preferably 6 carbon atoms when both R ³ and R ⁸ are hydrogen. To 12 alkyl groups, particularly preferably n-octyl group, tert-octyl group, 2-ethylhexyl group, n-decyl group, n-dodecyl group, most preferably 2-ethylhexyl. It is a group.

When R ³ and R ⁸ are preferably other than hydrogen as R ²¹ , the compound represented by the general formula (103-C) has a molecular weight of 300 or more and an alkyl group having 20 or less carbon atoms. preferable.

  The compound represented by the general formula (103) of the present invention can be synthesized by the method described in Journal of American Chemical Society 63, 3452 (1941).

(Matting agent fine particles)
Fine particles can be preferably added as a matting agent to the cellulose acylate film used in the present invention.

  The fine particles used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, silica Mention may be made of magnesium and calcium phosphates. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable. The fine particles of silicon dioxide 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 size of 0.1 to 3.0 μm, and these fine particles exist in the film as aggregates of primary particles, and 0.1 to 0.1 μm on the film surface. An unevenness of 3.0 μm is formed. The secondary average particle size is preferably 0.2 μm to 1.5 μm, more preferably 0.4 μm to 1.2 μm, and most preferably 0.6 μm to 1.1 μm. Regarding the primary and secondary particle sizes, the particles in the film are observed with a scanning electron microscope, and the diameter of a circle circumscribing the particles is defined as the particle size. Also, 200 particles are observed at different locations, and the average value is taken as the average particle size.

  As the fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above 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 a primary average particle size of 20 nm or less and an apparent specific gravity of 70 g / liter or more, and the coefficient of friction is maintained while keeping the turbidity of the optical film low. It is particularly preferable because it has a great effect of reducing the effect.

  In order to obtain a cellulose acylate film having particles having a small secondary average particle size in the present invention, several methods are conceivable when preparing a dispersion of fine particles. For example, a method of preparing a fine particle dispersion in which a solvent and fine particles are mixed with stirring in advance, adding this fine particle dispersion to a small amount of cellulose acylate solution separately prepared, stirring and dissolving, and further mixing with the main cellulose acylate dope solution There is. This method is a preferable preparation method in that the dispersibility of the silicon dioxide fine particles is good and the silicon dioxide fine particles are more difficult to reaggregate. In addition, after adding a small amount of cellulose ester to the solvent and dissolving with stirring, add the fine particles to this and disperse with a disperser to make this fine particle additive solution, and mix this fine particle additive solution with the dope solution using an in-line mixer. There is also a way to do it.

The method that can be used in the present invention is not limited to these, but the concentration of silicon dioxide when the silicon dioxide fine particles are mixed and dispersed with a solvent is preferably 5 to 30% by mass, more preferably 10 to 25% by mass. 15-20 mass% is the most preferable. A higher dispersion concentration is preferable because the liquid turbidity with respect to the added amount is lowered, and haze and aggregates are improved. The addition amount of the matting agent in the final cellulose acylate dope solution is preferably 0.01 to 1.0 g, more preferably 0.03 to 0.3 g, and 0.08 to 0.16 g per 1 m ^2. Most preferred.

  The solvent used is preferably lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like. 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 cellulose ester.

(Plasticizer, degradation inhibitor, release agent)
In addition to the above-mentioned compound that optically decreases anisotropy, wavelength dispersion adjusting agent, matting agent, the cellulose acylate film used in the present invention has various additives (for example, depending on the use in each preparation step) Plasticizers, UV inhibitors, deterioration inhibitors, release agents, infrared absorbers, and the like). These additives may 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, for example, in 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 cellulose acylate 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, but these are conventionally known techniques. For these details, the materials described in detail on pages 16 to 22 of the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical Number 2001-1745, published on March 15, 2001, Japan Institute of Invention) are preferably used.

(Additive ratio)
In the cellulose acylate film used in the present invention, the total amount of compounds having a molecular weight of 3000 or less is preferably 5 to 45% based on the weight of the cellulose acylate. More preferably, it is 10-40%, More preferably, it is 15-30%. As described above, these compounds include compounds that reduce optical anisotropy, wavelength dispersion regulators, ultraviolet inhibitors, plasticizers, deterioration inhibitors, fine particles, release agents, infrared absorbers, etc. Is preferably 3000 or less, more preferably 2000 or less, and still more preferably 1000 or less. When the total amount of these compounds is 5% or less, the properties of cellulose acylate alone are likely to be obtained, and there are problems such as that the optical performance and physical strength are likely to vary with changes in temperature and humidity. Moreover, when the total amount of these compounds is 45% or more, problems such as exceeding the limit of compatibility of the compounds in the cellulose acylate film and depositing on the film surface and causing the film to become cloudy (crying out of the film) occur. It becomes easy.

Production of Cellulose Acylate Film The production method of the cellulose acylate film used in the present invention is not particularly limited, but it is preferably produced by a solvent cast method. At this time, the film is produced using a solution (dope) obtained by dissolving cellulose acylate in an organic solvent.

(solvent)
The solvent used for dissolving cellulose acylate is not particularly limited.
Preferred organic solvents as the solvent are esters, ketones, ethers having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 7 carbon atoms. Esters, ketones and ethers may have a cyclic structure. A compound having two or more functional groups of esters, ketones and ethers (that is, —O—, —CO— and —COO—) can also be used as a main solvent. It may have a functional group of In the case of the main solvent having two or more kinds of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group.
For cellulose acylate, a chlorinated halogenated hydrocarbon may be used as a main solvent, and as described in JIII Journal of Technical Disclosure 2001-1745 (pages 12 to 16), a non-chlorine group is used. A solvent may be the main solvent.

  Other preferred solvents for the cellulose acylate solution and film of the present invention, including the dissolution method thereof, are, for example, JP-A-2000-95876, JP-A-12-95877, JP-A-10-324774, and JP-A-8. -152514, JP-A-10-330538, JP-A-9-95538, JP-A-9-95557, JP-A-10-235664, JP-A-12-63534, JP-A-11-21379, JP-A-10- No. 182853, JP-A-10-278056, JP-A-10-279702, JP-A-10-323853, JP-A-10-237186, JP-A-11-60807, JP-A-11-152342, JP-A-11-292988 No. 1, JP-A-11-60752, JP-A-11-60752, etc. There. These publications describe not only preferred solvents for cellulose acylate, but also their solution properties and coexisting substances to coexist. Adopting these is also preferable in the present invention.

(Dissolution process)
The method for dissolving cellulose acylate in the solvent is not particularly limited. The dissolution may be performed at room temperature, a cooling dissolution method or a high temperature dissolution method, or a combination thereof. Regarding the preparation of the cellulose acylate solution in the present invention, and further the steps of solution concentration and filtration accompanying the dissolution step, the technical report of the Japan Society of Invention (Publication No. 2001-1745, published on March 15, 2001, Japan Society of Invention) Production processes described in detail on pages 22 to 25 are preferably used.

(Transparency of dope solution)
The dope transparency of the cellulose acylate solution is preferably 85% or more. More preferably, it is 88% or more, More preferably, it is 90% or more. The above-mentioned various additives are sufficiently dissolved in the cellulose acylate dope solution. As a specific method for calculating the dope transparency, a method of injecting the dope solution into a 1 cm square glass cell and measuring the absorbance at 550 nm with a spectrophotometer (UV-3150, Shimadzu Corporation) can be employed. Only the solvent is measured in advance as a blank, and the transparency of the cellulose acylate solution is calculated from the ratio with the absorbance of the blank.

(Casting, drying, winding process)
Next, a method for producing a film using a cellulose acylate solution will be described. As a method and equipment for producing a cellulose acylate film, a conventionally used solution casting film forming method and solution casting film forming apparatus used for producing a cellulose triacetate film can be used. The dope (cellulose acylate solution) prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation. The dope is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the number of rotations, and the dope is run endlessly from the die (slit) of the pressure die. The dope film (also referred to as web) is peeled off from the metal support at a peeling point that is uniformly cast on the metal support, and the metal support has substantially gone around. The both ends of the obtained web are sandwiched between clips, transported by a tenter while holding the width and dried, and then the obtained film is mechanically transported by a roll group of a drying device, dried, and then rolled by a winder Wind up to a predetermined length. The combination of the tenter and the roll group dryer varies depending on the purpose. In the solution casting film forming method used for the functional protective film or the silver halide photographic light-sensitive material which is an optical member for electronic display, which is the main use of the cellulose acylate film of the present invention, a solution casting film forming apparatus In addition, a coating apparatus is often added for surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, and a protective layer. These are described in detail on pages 25 to 30 of the Japan Society for Invention and Innovation (Public Technical Number 2001-1745, published on March 15, 2001, Japan Society of Inventions), and casting (including co-casting) And can be preferably used in the present invention.
The thickness of the cellulose acylate film is preferably 10 to 120 μm, more preferably 20 to 100 μm, and still more preferably 30 to 90 μm.

Layer having an ultraviolet absorbing function In the present invention, a layer having an ultraviolet absorbing function (hereinafter referred to as an ultraviolet absorbing layer) is formed on the surface of the film satisfying the above formulas (I) and (II). The ultraviolet absorbing layer is usually a layer containing an ultraviolet absorber and a binder, preferably a mixture of an ultraviolet absorber, an active energy ray curable resin (particularly an ultraviolet curable resin) and a polymerization initiator is cured with active energy rays. Layer. Below, the material used for an ultraviolet absorption layer is demonstrated.

(UV absorber)
The ultraviolet absorber used in the present invention is a compound having an excellent ability to absorb ultraviolet rays having a wavelength of 380 nm or less. Examples of commonly used ultraviolet absorbers include benzotriazole compounds, benzophenone compounds (including oxybenzophenone compounds), salicylic acid ester compounds, cyanoacrylate compounds, nickel complex compounds, inorganic powders, and the like.

  As the benzotriazole ultraviolet absorber, a compound represented by the following general formula [1] is preferably used.

R ¹ , R ² , R ³ , R ⁴ and R ⁵ in the general formula [1] may be the same or different, and may be a hydrogen atom or a halogen atom (chlorine, bromine, iodine, fluorine). ), Nitro group, hydroxyl group, alkyl group (for example, methyl group, ethyl group, n-propyl group, iso-propyl group, aminopropyl group, n-butyl group, sec-butyl group, tert-butyl group, chlorobutyl group) N-amyl group, iso-amyl group, hexyl group, octyl group, nonyl group, stearylamidobutyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, cyclohexyl group, benzyl group, phenylethyl group, phenylpropyl group Etc.), alkenyl group (for example, vinyl group, allyl group, methallyl group, dodecenyl group, tridecenyl group, tetradecenyl group, octade group) Senyl group etc.), aryl group (eg phenyl group, 4-methylphenyl group, 4-ethoxyphenyl group, 2-hexoxyphenyl group, 3-hexoxyphenyl group etc.), alkoxy group (eg methoxy group, ethoxy group) , Propoxy group, butoxy group, chlorobutoxy group, decoxy group, diaminophenoxy group, ethoxy group, pentadecoxy group, octadecoxy group, etc.), acyloxy group (for example, carbomethoxy group, carbobutoxy group, carbohexoxy group, carbopentadecoxy group) Etc.), aryloxy groups (for example, phenoxy group, 4-methylphenoxy group, 2-propylphenoxy group, 3-amylphenoxy group, etc.), alkylthio groups (for example, methylthio group, ethylthio group, t-butylthio group, t- Octylthio group, benzylthio group, etc. , Arylthio groups (for example, phenylthio group, methylphenylthio group, ethylphenylthio group, methoxyphenylthio group, ethoxyphenylthio group, naphthylthio group, etc.), mono- or dialkylamino groups (for example, N-ethylamino group, N- t-octylamino group, N, N-diethylamino group, N, N-di-t-butylamino group, etc.), acylamino group (for example, acetylamino group, benzoylamino group, methanesulfonylamino group, etc.), oxygen or nitrogen A 5- or 6-membered heterocyclic group containing, for example, a piperidino group, a morpholino group, a pyrrolidino group, a piperazino group, or the like, and R ⁴ and R ⁵ are closed to form a 5- or 6-membered ring consisting of carbon atoms. May be.
In the general formula [1], the substituents represented by R ^{1 to} R ⁵ preferably have 5 to 36 carbon atoms, and the alkyl group preferably has 1 to 18 carbon atoms.

Although the example of a compound represented by General formula [1] is shown below, the ultraviolet absorber which can be used by this invention is not limited to these.
(1-1) 2- (2′-hydroxy-5′-t-butylphenyl) -benzotriazole (1-2) 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -Benzotriazole (1-3) 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole (1-4) 2- (2'-hydroxy-3 ' , 5'-di-t-butylphenyl) -5-chlorobenzotriazole (1-5) 2- (2'-hydroxy-5'-isooctylphenyl) -benzotriazole (1-6) 2- (2 '-Hydroxy-5'-n-octylphenyl) -benzotriazole (1-7) 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) -benzotriazole (1-8) 2- (2'-hydroxy-5'-dodecylphenyl)- Benzotriazole (1-9) 2- (2′-hydroxy-5′-hexadecylphenyl) -benzotriazole (1-10) 2- (2′-hydroxy-3′-t-amyl-5′-benzophenyl) ) -Benzotriazole

  Moreover, as a benzophenone type ultraviolet absorber which is one of the ultraviolet absorbers preferably used in the present invention, a compound represented by the following general formula [2] is preferably used.

In general formula [2], Y represents a hydrogen atom, a halogen atom or an alkyl group, an alkenyl group, an alkoxy group, and a phenyl group, and these alkyl group, alkenyl group, and phenyl group may have a substituent. . A represents a hydrogen atom, an alkyl group, an alkenyl group, a phenyl group, a cycloalkyl group, an alkylcarbonyl group, an alkylsulfonyl group or a —CO (NH) _n-1 —D group, and D represents an alkyl group, an alkenyl group or a substituent. Represents a phenyl group which may have m and n represent 1 or 2.

  In the above, the alkyl group can be exemplified by a straight or branched alkyl group having up to 24 carbon atoms, the alkoxy group can be exemplified by an alkoxy group having up to 18 carbon atoms, and the alkenyl group can be exemplified by carbon atoms. Up to 16 alkenyl groups can be exemplified, and specific examples include an allyl group and a 2-butenyl group. In addition, as a substituent to an alkyl group, alkenyl group, or phenyl group, a halogen atom (eg, a chlorine atom, a bromine atom, a fluorine atom, etc.), a hydroxy group, a phenyl group (the phenyl group includes an alkyl group or a halogen atom, etc.) And may be substituted).

  Specific examples of the benzophenone compound represented by the general formula [2] are shown below, but the ultraviolet absorbent that can be used in the present invention is not limited to these.

Examples of salicylic acid ester compounds that are one of the ultraviolet absorbers preferably used in the present invention include phenyl salicylate.
Examples of the cyanoacrylate compound that is one of the ultraviolet absorbers preferably used in the present invention include 2-ethylhexyl-2-cyano-3,3′-diphenylacrylate.
Examples of the inorganic powder that is one of the ultraviolet absorbers preferably used in the present invention include ultrafine titanium oxide, ultrafine zinc oxide, ultrafine iron oxide, ultrafine cerium oxide, and silica-cerium oxide-coated pigment. Can be mentioned.

(UV absorbing layer)
The UV absorbing layer is prepared by blending UV absorbers alone or in combination with two or more binder components and solvent components such as synthetic resins so that they can be applied and printed. Gravure coating and flexographic printing It is formed by applying and printing on the surface of the film by a known printing means such as a method. When curing is required, the cured product is cured with active energy rays after drying.
The ultraviolet absorbing layer only needs to have a thickness capable of maintaining the ultraviolet shielding property and other physical properties, and the thickness is preferably 0.5 to 50 μm, more preferably 0.5 to 5 μm. The ultraviolet absorbing layer is formed on at least one surface of the film satisfying the above formulas (I) and (II). The ultraviolet absorbing layer may be formed on both sides of the film. By forming the ultraviolet absorbing layer, the light resistance can be improved and the film can be prevented from being colored.

Examples of the synthetic resin used for the ultraviolet absorbing layer include generally used synthetic resins such as cellulose acylate, acrylic resin, and polyester resin.
As a solvent to be used, a general solvent can be used as long as there is no problem in dissolution. Preferable examples include ketones such as methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, ethers such as ether and tetrahydrofuran, alcohols such as ethanol, and the like.
As for the compounding quantity of the ultraviolet absorber with respect to binders, such as a synthetic resin, it is preferable that an ultraviolet absorber is 0.1-10 mass parts with respect to 100 mass parts of binders, and it is more preferable that it is 1-5 mass parts. If the ultraviolet absorber is 0.1 parts by mass or more, an ultraviolet absorption effect is easily obtained, and if the ultraviolet absorber is 10 parts by mass or less, the ultraviolet absorber crys out and tends not to cause a haze increase. There is.

(Active energy ray curable resin)
Further, in order to increase the hardness of the ultraviolet absorbing layer, an active energy ray-curable resin can be used instead of the above synthetic resin. As a curing method, a method of irradiating with an electron beam or ultraviolet rays is preferable, and a method of irradiating with ultraviolet rays is more preferable. As the resin that is cured by ultraviolet rays, polyfunctional acrylates having an ethylenically unsaturated group that undergo photoradical polymerization and ring-opening polymerizable compounds that undergo photocationic polymerization are preferred.

Preferred types of ethylenically unsaturated groups are acryloyl group, methacryloyl group, vinyl group, styryl group and allyl group, and particularly preferably acryloyl group. These curable resins containing two or more ethylenically unsaturated groups in the same molecule may be used alone or in combination.
Examples of the curable resin containing two or more ethylenically unsaturated groups in the same molecule include a curable resin called a polyfunctional (meth) acrylate monomer, urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meta ) An oligomer having a molecular weight of several hundred to several thousands having three or more (meth) acrylic acid ester groups in a molecule called acrylate can be preferably used. In this specification, (meth) acrylate means an acrylate or a methacrylate.

  Specific examples of the curable resin having two or more acrylic groups in the same molecule include butanediol diacrylate, hexanediol diacrylate, ethylene glycol diacrylate, polyethylene glycol diacrylate, 1,4-cyclohexane diacrylate, Polyol polyacrylates such as methylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and hydroxyl groups such as polyisocyanate and hydroxyethyl acrylate Urethane acrylate, bisphenol A, etc. obtained by reaction of acrylate containing glycidyl Epoxy acrylates obtained by a reaction such as acrylate, tris (acryloxyethyl) isocyanurate, and the like.

Other curable resins include styrene compounds (for example, 1,4-divinylbenzene, 4-vinylbenzoic acid-2-acryloylethyl ester), 1,4-divinylcyclohexanone, vinyl sulfone (for example, divinyl sulfone), acrylamide (For example, methylenebisacrylamide) and the like.
Further, as the curable resin and its monomer, for example, those described in “Photocuring Technology Data Book Material” (Technonet Books, Technonet) and the like can be used.

The curable resin containing a ring-opening polymerizable group is preferably a curable resin having a ring structure in which ring-opening polymerization proceeds by the action of a cation, anion, radical, etc., and among them, a heterocyclic group-containing curable resin is preferable. . Examples of such curable resins include epoxy compounds, oxetane compounds, tetrahydrofuran compounds, cyclic lactone compounds, cyclic carbonate compounds, cyclic imino ethers such as oxazoline compounds, and the like, and epoxy compounds, oxetane compounds, and oxazoline compounds are particularly preferable.
In the present invention, the curable resin having a ring-opening polymerizable group preferably has two or more ring-opening polymerizable groups in the same molecule, more preferably three or more. In the present invention, two or more curable resins having a ring-opening polymerizable group may be used in combination. In this case, a curable resin having one ring-opening polymerizable group in the same molecule is used as necessary. Can be used together.

  The curable resin having a ring-opening polymerizable group in the present invention is not particularly limited as long as it is a curable resin having a cyclic structure as described above. Preferred examples of such curable resins include monofunctional glycidyl ethers, monofunctional alicyclic epoxies, difunctional alicyclic epoxies, diglycidyl ethers (for example, ethylene glycol diglycidyl ether as glycidyl ethers). Bisphenol A diglycidyl ether), trifunctional or higher glycidyl ethers (trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, triglycidyl trishydroxyethyl isocyanurate, etc.), tetrafunctional or higher glycidyl Ethers (sorbitol tetraglycidyl ether, pentaerythritol tetraglycyl ether, polyglycidyl ether of cresol novolac resin, phenol novolac Fatty polyglycidyl ether, etc.), cycloaliphatic epoxies (Celoxide 2021P, Celoxide 2081, Epolide GT-301, Epolide GT-401 (above, Daicel Chemical Industries, Ltd.), EHPE (Daicel Chemical Industries, Ltd.) ), Phenol novolak resin polycyclohexyl epoxy methyl ether, etc.), oxetanes (OX-SQ, PNOX-1009 (above, manufactured by Toagosei Co., Ltd.), etc.), etc., which can be used in the present invention. The functional resin is not limited to these.

  It is particularly preferable that the curable resin having a ring-opening polymerizable group contains a crosslinkable polymer containing a ring-opening polymerizable group in a repeating unit. For example, an acrylate ester having a ring-opening polymerizable group is preferable. Examples of the ring-opening polymerizable group include monovalent rings including an imino ether ring such as an epoxy ring, an oxetane ring, a tetrahydrofuran ring, a lactone ring, a carbonate ring, and an oxazoline ring. Among these, a monovalent group including an epoxy ring, an oxetane ring and an oxazoline ring is particularly preferable. A specific example is a polymer of glycidyl methacrylate.

(Polymerization initiator)
In forming the ultraviolet absorbing layer in the present invention, a polymerization initiator may be used. In particular, in the case of curing by ultraviolet irradiation, insufficient curing by the ultraviolet absorber can be prevented by using a polymerization initiator having a photosensitive wavelength in the near ultraviolet region in combination. Examples of the polymerization initiator in the near ultraviolet region include 2,4,6-trimethylbenzoyldiphenylphosphine oxide (DAROCUR (registered trademark) TPO; manufactured by Ciba Specialty Chemicals), phenylbis (2,4,6 -Trimethylbenzoyl) -phosphine oxide (IRGACURE (registered trademark) 819; manufactured by Ciba Geigy); manufactured by Ciba Pacety Chemicals), bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphos Phosphine oxides such as fin oxide, thioxanthone such as 2,4-diethylthioxanthone, 2-chlorothioxanthone, 1-chloro-4-propoxythioxanthone, N-methylacridone, bis (dimethylaminophenyl) ketone, 2-benzyl -2-di Ketones such as tilamino-1- (4-morpholinophenyl) -butan-1-one (IRGACURE (registered trademark) 369; manufactured by Ciba Pacecity Chemicals), 1,2-octanedione-1- [4- Compounds having an absorption terminal up to around 400 nm, such as oximes such as (phenylthio) -2,2- (O-benzoyloxime)], are preferred. In order to reduce coloring of the produced film, phosphine oxide having a large decoloring after irradiation is particularly preferable.
The ultraviolet wavelength is preferably in the range of 300 to 460 nm, and the radiation source is preferably a high pressure mercury lamp or a metal halide lamp. As an irradiation amount of an ultraviolet-ray, 300-1200 mJ / cm < ² > is preferable and 400-1000 mJ / cm < ² > is further more preferable. The irradiation unit is preferably filled with an inert gas such as nitrogen. Further, the ultraviolet irradiation can be performed in a flat state or a state wound around a cooled or heated roll.

Use of laminated film The laminated film of the present invention can be used in various applications. In particular, since the laminated film of the present invention has good optical properties, it can be preferably used as an optical film. Below, the typical use of the laminated | multilayer film of this invention is demonstrated.

(Polarizer)
The laminated film of the present invention is particularly useful as a protective film for a polarizing plate. When using as a protective film of a polarizing plate, the production method of the polarizing plate itself is not particularly limited, and can be produced by a general method. As a typical method, the obtained cellulose acylate film is treated with an alkali, 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. Can be mentioned. Instead of alkali treatment, easy adhesion processing as described in JP-A-6-94915 and JP-A-6-118232 may be performed.
Examples of the adhesive used for bonding 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.
A polarizing plate is composed of a polarizer and a protective film that protects both sides of the polarizer, and is generally composed of a protective film on one side of the polarizing plate and a separate film on the other side. is there. 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 contact bonding 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 containing liquid crystal is usually disposed between two polarizing plates. However, a polarizing plate protective film to which the laminated film of the present invention is applied can provide excellent display properties regardless of the location. . In particular, the polarizing plate protective film on the outermost surface of the display side of the liquid crystal display device is provided with a transparent hard coat layer, an antiglare layer, an antireflection layer, and the like.

(Optical compensation film)
The laminated film of the present invention can also be used as an optical compensation film. When used as an optical compensation film, the transmission axis of the polarizing element and the slow axis of the optical compensation film made of a cellulose acylate film may be arranged at any angle. A typical liquid crystal display device includes a liquid crystal cell in which liquid crystal is supported between two electrode substrates, two polarizing elements disposed on both sides thereof, and at least a gap between the liquid crystal cell and the polarizing element. It has a configuration in which one optical compensation film is arranged.

(Use for liquid crystal display devices)
The liquid crystal layer of the liquid crystal cell is usually formed by sealing liquid crystal in a space formed by sandwiching a spacer between two substrates. The transparent electrode layer is formed on the substrate as a transparent film containing a conductive substance. The liquid crystal cell may further be provided with a gas barrier layer, a hard coat layer, or an undercoat layer (undercoat layer) (used for adhesion of the transparent electrode layer). These layers are usually provided on the substrate. The substrate of the liquid crystal cell generally has a thickness of 50 μm to 2 mm.
The laminated 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-ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend), STN (Supper Twisted Nematic), VA (Vertically Aligned), 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 cellulose acylate 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.

(TN type liquid crystal display device)
The laminated film of the present invention may be used as a support for an optical compensation sheet of a TN type liquid crystal display device having a TN mode liquid crystal cell. TN mode liquid crystal cells and TN type liquid crystal display devices have been well known for a long time. The optical compensation sheet used in the TN type liquid crystal display device is described in JP-A-3-9325, JP-A-6-148429, JP-A-8-50206, and JP-A-9-26572. Also described in Mori et al. (Jpn. J. Appl. Phys. Vol. 36 (1997) p.143 and Jpn. J. Appl. Phys. Vol. 36 (1997) p. 1068). is there.

(STN type liquid crystal display device)
The laminated film of the present invention may be used as a support for an optical compensation sheet of an STN type liquid crystal display device having an STN mode liquid crystal cell. In general, in a STN type liquid crystal display device, rod-like liquid crystalline molecules in a liquid crystal cell are twisted in the range of 90 to 360 degrees, and the refractive index anisotropy (Δn) and cell gap (d) of the rod-like liquid crystalline molecules. Product (Δnd) is in the range of 300 to 1500 nm. The optical compensation sheet used in the STN type liquid crystal display device is described in JP-A-2000-105316.

(VA type liquid crystal display device)
The laminated film of the present invention is particularly useful as a support for an optical compensation sheet of a VA liquid crystal display device having a VA mode liquid crystal cell. It is preferable that Re of the optical compensation sheet used for the VA liquid crystal display device is 0 to 150 nm and Rth is 70 to 400 nm. More preferably, Re is 20 to 70 nm. When two optically anisotropic polymer films are used for the VA liquid crystal display device, the Rth of the film is preferably 70 to 250 nm. When one optically anisotropic polymer film is used for the VA liquid crystal display device, the Rth of the film is preferably 150 to 400 nm. The VA-type liquid crystal display device may be an alignment-divided system as described in, for example, JP-A-10-123576.

(IPS liquid crystal display device and ECB liquid crystal display device)
The laminated film of the present invention is particularly useful as a support for an optical compensation sheet of an IPS liquid crystal display device and an ECB liquid crystal display device having IPS mode and ECB mode liquid crystal cells, or as a protective film for a polarizing plate. In these modes, the liquid crystal material is aligned substantially in parallel during black display, and black is displayed by aligning liquid crystal molecules in parallel with the substrate surface in the absence of applied voltage. In these embodiments, the polarizing plate using the cellulose acylate film of the present invention contributes to improving the color tone, widening the viewing angle, and improving the contrast. In this aspect, the cellulose acylate film of the present invention is used for the protective film (the protective film on the cell side) disposed between the liquid crystal cell and the polarizing plate among the protective films of the polarizing plates above and below the liquid crystal cell. It is preferable to use the polarizing plate at least on one side. More preferably, an optically anisotropic layer is disposed between the protective film of the polarizing plate and the liquid crystal cell, and the retardation value of the disposed optically anisotropic layer is twice the value of Δn · d of the liquid crystal layer. It is preferable to set as follows.

(OCB type liquid crystal display device and HAN type liquid crystal display device)
The laminated film of the present invention is also useful as a support for an optical compensation sheet of an OCB type liquid crystal display device having an OCB mode liquid crystal cell or a HAN type liquid crystal display device having a HAN mode liquid crystal cell. In the optical compensation sheet used for the OCB type liquid crystal display device or the HAN type liquid crystal display device, it is preferable that the direction in which the absolute value of retardation is minimum does not exist in the plane of the optical compensation sheet or in the normal direction. The optical properties of the optical compensation sheet used in the OCB type liquid crystal display device or the HAN type liquid crystal display device are also the optical properties of the optical anisotropic layer, the optical properties of the support, and the optical anisotropic layer and the support. Is determined by the arrangement of An optical compensation sheet used for an OCB type liquid crystal display device or a HAN type liquid crystal display device is described in JP-A-9-197397. It is also described in Mori et al. (Jpn. J. Appl. Phys. Vol. 38 (1999) p. 2837).

(Reflective liquid crystal display)
The laminated film of the present invention is also useful as an optical compensation sheet for TN-type, STN-type, HAN-type, and GH (Guest-Host) -type reflective liquid crystal display devices. These display modes have been well known since ancient times. The TN type reflection type liquid crystal display device is described in JP-A-10-123478, International Publication No. 98/48320, and Japanese Patent No. 3022477. The optical compensation sheet used in the reflective liquid crystal display device is described in International Publication No. 00-65384 pamphlet.

(Other liquid crystal display devices)
The laminated film of the present invention is also useful as a support for an optical compensation sheet of an ASM type liquid crystal display device having an ASM (Axially Symmetric Aligned Microcell) mode liquid crystal cell. The ASM mode liquid crystal cell is characterized in that the thickness of the cell is maintained by a resin spacer whose position can be adjusted. Other properties are the same as those of the TN mode liquid crystal cell. The ASM mode liquid crystal cell and the ASM type liquid crystal display device are described in a paper by Kume et al. (Kume et al., SID 98 Digest 1089 (1998)).

(Transparent substrate)
Since the laminated film of the present invention has an optical anisotropy close to zero and excellent transparency, it can be used as an alternative to the liquid crystal cell glass substrate of a liquid crystal display device, that is, as a transparent substrate that encloses driving liquid crystals. Can be used.
Since the transparent substrate enclosing the liquid crystal needs to be excellent in gas barrier properties, a gas barrier layer may be provided on the surface of the cellulose acylate film of the present invention as necessary. The form and material of the gas barrier layer are not particularly limited, but SiO ₂ or the like is vapor-deposited on at least one surface of the cellulose acylate film of the present invention, or a relatively gas barrier property such as vinylidene chloride polymer or vinyl alcohol polymer. A method of providing a high polymer coat layer can be considered, and these can be used as appropriate.
In order to use as a transparent substrate for enclosing liquid crystal, a transparent electrode for driving the liquid crystal by applying a voltage may be provided. Although it does not specifically limit as a transparent electrode, A transparent electrode can be provided by laminating | stacking a metal film, a metal oxide film, etc. on the at least single side | surface of the cellulose acylate film of this invention. Among these, a metal oxide film is preferable from the viewpoint of transparency, conductivity, and mechanical properties, and an indium oxide thin film mainly containing 2 to 15% of zinc oxide can be preferably used. Details of these techniques are described in, for example, Japanese Patent Application Laid-Open Nos. 2001-125079 and 2000-227603.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

(1) Production of Cellulose Acylate Film The following composition was put into a mixing tank, stirred while heating to dissolve each component, and a cellulose acylate solution A was prepared. It filtered with the filter paper (Toyo Filter Paper Co., Ltd. product # 63) with an absolute filtration precision of 0.01 mm, and also filtered with the filter paper (Paul company make, FH025) of an absolute filtration precision 0.0025 mm.

<Composition of cellulose acylate solution A>
Cellulose acetate having a substitution degree of 2.86 100 parts by mass N-phenyl p-toluenesulfonamide 17.7 parts by mass 2-hydroxy 4-octyloxybenzophenone 1.2 parts by mass Silica particles (R972 from Nippon Aerosil Co., Ltd.) 13 parts by mass Methylene chloride 518 parts by mass Methanol 77 parts by mass Citric acid ester 0.01 parts by mass

  The cellulose acylate solution was cast using a band casting machine. When the amount of residual solvent reached about 60% by mass, the film was peeled from the band and dried at 135 ° C. for 20 minutes to produce a cellulose acylate film. The completed cellulose acylate film had a residual solvent amount of 0.15% by mass and a film thickness of 80 μm.

(2) Production of ultraviolet absorbing layer (production of laminated film of Example 1)
A coating solution prepared by dissolving the following components in methyl ethyl ketone is applied onto the above cellulose acylate film of 80 μm using a gravure coater so as to have a film thickness of 3 μm. Formed.
2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl)-
Benzotriazole 3 parts by mass Polyvinyl butyral resin 100 parts by mass

(Production of laminated film of Example 2)
A solution prepared by dissolving the following components in methyl ethyl ketone was mixed with stirring, and filtered with a filter having a pore size of 10 μm (polypropylene filter (PPE-10). The above cellulose having a thickness of 80 μm was obtained using a gravure coater. A coated film having a thickness of 3 μm was formed by coating and drying on an acylate film, and irradiation with a metal halide lamp (observed values at 500 mJ / cm ² : 350 to 390 nm) was performed to produce a laminated film.
2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl)-
Benzotriazole 3 parts by weight Trimethylolpropane triacrylate (Biscoat # 295; manufactured by Osaka Organic Chemical Industry Co., Ltd.) 100 parts by weight Photoradical polymerization initiator (Darocur TPO (manufactured by Ciba Specialty Chemicals)) 2 parts by weight

(3) Evaluation The following evaluation was performed about each laminated film of Example 1 and Example 2, and said cellulose acylate film (comparative example 1) which has not formed the ultraviolet absorption layer.
(Measurement of in-plane retardation Re and thickness direction retardation Rth)
Sample 30mm x 40mm is conditioned for 2 hours at 25 ° C and 60% relative humidity. Re is an automatic birefringence meter KOBRA 21ADH (manufactured by Oji Scientific Instruments Co., Ltd.). Measured. Rth is the retardation measured by injecting light having a wavelength of 590 nm with the slow axis in the plane as the tilt axis and the normal direction of the film as 0 °, and tilting the sample to 50 ° every 10 °. Based on the values, the assumed average refractive index of 1.48 and the film thickness were input and calculated.

(Light resistance test)
Each film was irradiated with super xenon light for 240 hours. The change in absorption at 380 nm of the film before and after irradiation was measured using a spectrophotometer (U-3210, Hitachi, Ltd.) at 25 ° C. and a relative humidity of 60%. If the change is 0.03 or less, it is an acceptable range.

(Abrasion resistance test)
The surface of each film was rubbed under a load of 200 g using Bon Star No. 0000 manufactured by Nippon Steel Wool Co., Ltd. About the laminated | multilayer film of Example 1 and Example 2, the side in which the ultraviolet absorption layer was formed was rubbed. The surface was rubbed until scratches were confirmed with the naked eye, and the number of rubs was recorded. When scratches were not observed on the surface even after rubbing 10 times, the test was terminated, and the result was expressed as “<10”.

  The laminated film of the present invention provided with an ultraviolet absorbing layer has improved light durability. Furthermore, the scratch resistance of the surface is improved by combining an ultraviolet curable resin.

(Preparation of polarizing plate)
The cellulose acylate film on which the ultraviolet absorption layer of the present invention produced in Example 2 was laminated was immersed in a 1.5 mol / L sodium hydroxide aqueous solution (55 ° C.) for 2 minutes. It wash | cleaned in the room temperature water-washing bath, and neutralized using 0.05 mol / L sulfuric acid at 30 degreeC. Again, it was washed in a water bath at room temperature and further dried with hot air at 100 ° C. In this way, the surface of the cellulose acylate film was saponified.
Subsequently, a polarizing film made of a roll-like polyvinyl alcohol film having a thickness of 80 μm, which was continuously stretched 5 times in an aqueous iodine solution and dried, was used as an adhesive with a 3% aqueous solution of polyvinyl alcohol (manufactured by Kuraray, PVA-117H). The polarizing plate protected by bonding and the cellulose acylate film was obtained. At this time, the side on which the ultraviolet absorbing layer was not provided was bonded to polyvinyl alcohol. Adhesiveness with the stretched polyvinyl alcohol was sufficient, and had excellent polarizing plate processing suitability.
About the obtained polarizing plate, the light resistance test was done by said method. The change in transmittance of 550 nm light when irradiated with super xenon light from the ultraviolet absorbing layer side is 0.5%, and the change in transmittance of 550 nm light when irradiated with super xenon light from the opposite side is 2%. (The transmittance before the light resistance test was 43%).

The laminated film of the present invention is characterized by small optical anisotropy (Re, Rth), substantially optical isotropy, and small wavelength dispersion. Moreover, the laminated film of the present invention is excellent in light resistance, and the surface hardness can be improved. Such a laminated film is useful as an optical film excellent in optical characteristics such as viewing angle characteristics.
In particular, when the liquid crystal display device is produced using the laminated film of the present invention as a protective film for a polarizer, a support for an optical compensation film, or the like, the display color can be improved. In addition, it is possible to prevent light deterioration and damage when used on the surface of a liquid crystal display device. In particular, it is effective when used on the surface on the viewing side of the polarizing plate of a liquid crystal display device and when used on the surface on the backlight side. For this reason, this invention has high industrial applicability.

Claims (6)

A laminated film in which a layer having an ultraviolet absorbing function is formed on the surface of a film satisfying the following formulas (I) and (II).
Formula (I): 0 ≦ Re (630) ≦ 10 and | Rth (630) | ≦ 25
Formula (II): | Re (400) −Re (700) | ≦ 10 and | Rth (400) −Rth (700) | ≦ 35
[In the formula, Re (λ) is a front retardation value (unit: nm) at a wavelength λnm, and Rth (λ) is a retardation value (unit: nm) in a film thickness direction at a wavelength λnm. ]   The laminated film according to claim 1, wherein the layer having an ultraviolet absorbing function is made of a material obtained by curing a mixture of an ultraviolet absorber, an active energy ray curable resin, and a polymerization initiator with an active energy ray.   The film is a cellulose acylate film having an acyl substitution degree of 2.85 to 3.00, and at least one compound that reduces the optical anisotropy of the film is added to the solid content of the cellulose acylate. The laminated film according to claim 1 or 2, comprising 0.01 to 30% by weight.   The laminated film according to claim 1, wherein the film has a thickness of 10 to 120 μm.   A polarizing plate formed by forming the laminated film according to claim 1 on at least one surface of a polarizer.   A liquid crystal display device comprising the polarizing plate according to claim 5.