WO2016038922A1

WO2016038922A1 - Optical film, polarizing plate, and image display device

Info

Publication number: WO2016038922A1
Application number: PCT/JP2015/061613
Authority: WO
Inventors: 佐々木　謙一; 絢子稲垣; 知世安達; 岡野　賢
Original assignee: コニカミノルタ株式会社
Priority date: 2014-09-10
Filing date: 2015-04-15
Publication date: 2016-03-17

Abstract

An optical film (15) is equipped with a cured layer (13) that is provided on at least one surface of a transparent substrate (a film substrate (12)). The transparent substrate is a cellulose film having a film thickness of 5 μm or more and less than 35 μm. The cured layer (13) contains at least one active-energy-ray-curable resin (A) and at least one compound (B). The active-energy-ray-curable resin (A) is a resin in which a spacer that links two active energy groups to each other has up to 8 linearly arranged atoms and the spacer contains no ring structure. The compound (B) is a compound having a ring structure and having a first acid dissociation constant pKa₁ of 1.0 to 7.0 inclusive.

Description

Optical film, polarizing plate and image display device

The present invention relates to an optical film having a cured layer on at least one surface of a transparent substrate, a polarizing plate having the optical film, and an image display device having the polarizing plate.

A liquid crystal display (LCD), which is one type of image display device, is widely used because it is thin, lightweight, and consumes little power. The liquid crystal display device includes a liquid crystal cell and a polarizing plate, and includes a liquid crystal cell sandwiched between two substrates (for example, a glass substrate) and sandwiched between two polarizing plates. The polarizing plate is usually constituted by laminating a cellulose film and a polarizing film (polarizer). The polarizing film made of a polyvinyl alcohol film is dyed with iodine and stretched, and the cellulose film is formed on both surfaces thereof. It is comprised by laminating.

Cellulose film is strong as the film itself, and has high handleability in the manufacturing process of polarizing plates, and has high reworkability after being made into polarizing plates and bonded to panels (liquid crystal cells). The demand is strong. However, since the cellulose film has high hygroscopicity and the polarizer is easily deteriorated by moisture, the cellulose film alone does not have sufficient protective function for the polarizer.

Therefore, in

Patent Documents

1 and 2, for example, a cured layer is formed on a cellulose acylate film using a resin composition having a compound having a ring structure, thereby reducing the moisture permeability of the entire film, and thereby a polarizer. There has been proposed a protective film that improves the protective function. As the cellulose acylate film, a film having a film thickness of 80 μm is used in Patent Document 1, and a film having a film thickness of 60 μm is used in Patent Document 2.

JP 2006-83225 A (see claims 1 to 3, paragraphs [0005], [0007], [0013], [0057], etc.) Japanese Patent Laying-Open No. 2014-95890 (see claims 1 and 10, paragraphs [0006], [0007], [0031], [0236], etc.)

By the way, in the recent small and medium size liquid crystal display market, in order to improve display performance and to make the display thinner, it is required to make the polarizing plate thinner, and the polarizer and the protective film are required to be made thinner. In addition, the use situation of medium- and small-sized liquid crystal displays has been diversified in recent years. For example, the use in a severe environment of high temperature and high humidity is increasing.

However, the durability of the polarizer deteriorates as the polarizer becomes thinner. In addition, when the protective film (especially the film base material) is made thin, the moisture permeability of the protective film increases significantly and the protective function of the polarizer decreases in a high-temperature and high-humidity environment. Deteriorates further. For this reason, even if a film base material is a thin film, the protective film which can suppress the raise of the water vapor transmission rate in a high temperature, high humidity environment, and can suppress the fall of the protective function of a polarizer is calculated | required.

In this regard, the protective films of

Patent Documents

1 and 2 are configured using a film base having a thickness of 80 μm or 60 μm, and the film base is a thin film (for example, a thickness of less than 35 μm), It does not suppress an increase in moisture permeability in a high temperature and high humidity environment, and does not suppress a decrease in the protective function of the polarizer.

The present invention has been made to solve the above-described problems, and its purpose is to increase the moisture permeability in a high-temperature and high-humidity environment with a configuration in which a cured layer is formed on a thin cellulose-based film. Even when applied to a protective film for a polarizing plate, an optical film capable of suppressing a decrease in the protective function of the polarizer, a polarizing plate having the optical film, and an image having the polarizing plate It is to provide a display device.

The inventors of the present application have found that the above-mentioned problems can be solved by forming a cured layer having the following constitution on at least one surface of a thin cellulose-based film substrate. That is, the above object of the present invention is achieved by the following configuration.

An optical film according to one aspect of the present invention is an optical film having a cured layer on at least one surface of a transparent substrate,
The transparent substrate is a cellulose film having a film thickness of 5 μm or more and less than 35 μm,
The cured layer is
At least one kind of active energy ray-curable resin (A), wherein the maximum number of atoms arranged in a straight line as a spacer connecting two active energy groups is 8 or more, and the spacer does not contain a ring structure; ,
And at least one compound (B) having a ring structure and having a first acid dissociation constant pKa ₁ of 1.0 or more and 7.0 or less.

According to the configuration of the optical film, the cured layer formed on the thin cellulose film having a film thickness of 5 μm or more and less than 35 μm contains the specific resin and the specific compound. The increase in moisture permeability under the environment can be suppressed. Thereby, even when the said optical film is applied to the protective film of a polarizing plate, the fall of the protective function of a polarizer can be suppressed and the durable fall of a polarizer can be suppressed.

1 is a cross-sectional view illustrating a schematic configuration of an image display device according to an embodiment of the present invention. It is sectional drawing which shows the structure of the optical film applied to the polarizing plate of the said image display apparatus.

An embodiment of the present invention will be described below with reference to the drawings. In this specification, when the numerical range is expressed as A to B, the numerical value range includes the values of the lower limit A and the upper limit B. The present invention is not limited to the following contents.

In the optical film in which a cured layer is formed on a thin cellulose-based film having a film thickness of 5 μm or more and less than 35 μm, the inventors of the present application form atoms arranged in a straight line as a spacer connecting two active energy groups to the cured layer. Is at least one active energy ray-curable resin (A) (hereinafter simply referred to as “the number of linear maximum atoms”) and 8 or less, and the spacer does not contain a ring structure. It is also found that the above-mentioned problem can be solved by including a curable resin (A) ”and a compound having a ring structure and a first acid dissociation constant pKa ₁ in a specific range (B). It was. The reason why the above problem can be solved is estimated as follows.

The cured layer containing the curable resin (A) and the compound (B) is prepared by preparing a cured layer composition (coating liquid) containing the curable resin (A) and the compound (B), and is cellulose-based. It is formed by coating on a film and curing the coating layer by irradiation with active energy rays. The curable resin (A) contains an active energy group having a polar group, which causes an increase in moisture permeability in a high temperature and high humidity environment. Therefore, by adding the compound (B) having a polar group having a first acid dissociation constant pKa ₁ of 1.0 or more and 7.0 or less, the polar group of the compound (B) is activated by the activity of the curable resin (A). It is possible to reduce polar portions that interact with the energy group and cause an increase in moisture permeability in a high-temperature and high-humidity environment. The curable resin (A) in which the maximum number of atoms arranged in a straight line as a spacer connecting two active energy groups is 8 or more and the spacer does not contain a ring structure is a compound having no steric hindrance. A cured film that can interact with (B) and has no gaps can be formed. As a result, when the coating layer is cured to form a cured layer, an increase in moisture permeability under a high temperature and high humidity environment can be suppressed.

From the viewpoint of surely obtaining the effect of the present embodiment described above, in the curable resin (A), the maximum number of linear atoms is preferably 10 or more, and more preferably 11 or more. Moreover, since it will become difficult to obtain predetermined | prescribed hardness as a hardened layer when a linear maximum atom number exceeds 25, it is preferable that the upper limit of a linear maximum atom number is 25. In the curable resin (A), the number of atoms arranged in a straight line as the spacer is preferably 8 or more, and more preferably 10 or more, for any spacer connecting any two active energy groups. Preferably, it is 11 or more.

When the first acid dissociation constant pKa ₁ is less than 1.0, the polarity of the compound (B) is too high and the cured layer easily absorbs moisture, so that the moisture permeability increases in a high temperature and high humidity environment. It becomes difficult to suppress this. On the other hand, when the first acid dissociation constant pKa ₁ exceeds 7.0, the polarity of the compound (B) is too low to interact with the polar part of the active energy group of the curable resin (A), and the high temperature and high humidity It becomes difficult to suppress an increase in moisture permeability under the environment. A preferred range of the first acid dissociation constant pKa ₁ is 2.0 or more and 6.0 or less, and a more preferred range is 2.5 or more and 5.5 or less.

In addition, the low molecular weight additive (compound (B)) is likely to bleed and the moisture permeation performance is likely to be deteriorated thereby, so that the molecular weight of the compound (B) is preferably 130 or more. On the other hand, since the high molecular weight additive tends to deteriorate the cross-linking rate of the resin and deteriorate the moisture permeability, the molecular weight of the compound (B) is preferably 500 or less.

In addition, when the cellulose-based film is a cellulose ester film, it is possible to add a specific organic acid, a phenol compound, or a compound containing a benzene ring in the main chain to the cellulose ester film, because it is excellent in suppressing deterioration of the polarizer. This is a preferred embodiment of the present invention.

Hereinafter, a specific configuration of the image display device to which the optical film of the present embodiment is applied will be described.

[Configuration of image display device]
FIG. 1 is a cross-sectional view illustrating a schematic configuration of an image display device 1 according to the present embodiment. The image display device 1 is, for example, a liquid crystal display device, and is configured by bonding a protective portion 3 to a polarizing plate 5 (particularly on an optical film 15 described later) of the liquid crystal display panel 2 via a filling layer 31. Yes. The filling layer 31 is an adhesive layer (void filler) made of a photocurable resin such as acrylic, and is formed on the entire surface of the polarizing plate 5 of the liquid crystal display panel 2. The protection unit 3 protects the surface of the liquid crystal display panel 2 and is formed of a front plate made of acrylic resin or glass, for example. Note that a touch panel (such as a capacitance method or a resistance film method) may be used as the protection unit 3 instead of the front plate.

The liquid crystal display panel 2 is configured by disposing

polarizing plates

5 and 6 on both sides of a liquid crystal cell 4 (display cell) in which a liquid crystal layer is sandwiched between a pair of substrates. The polarizing plate 5 is attached to one surface side (for example, the viewing side) of the liquid crystal cell 4 via the adhesive layer 7. The polarizing plate 6 is attached to the other surface side (for example, the backlight 9 side) of the liquid crystal cell 4 through the adhesive layer 8. The driving method of the liquid crystal display panel 2 is not particularly limited, and various driving methods such as an IPS (In Plane Switching) type and a TN (Twisted Nematic) method can be employed.

The polarizing plate 5 includes a polarizer 11 that transmits predetermined linearly polarized light, a film substrate 12 and a cured layer 13 that are sequentially stacked on the protective portion 3 side of the polarizer 11, and a liquid crystal cell 4 side of the polarizer 11. The optical film 14 is made up of. The film base 12 and the cured layer 13 constitute an optical film 15 as a protective film formed on the surface on the viewing side of the polarizer 11. The film substrate 12 is a transparent substrate made of a cellulose film. Examples of the cellulose film include a cellulose ether film and a cellulose ester film described later. By providing the cured layer 13 on the film substrate 12, the surface of the polarizing plate 5 can be protected.

The film thickness of the film substrate 12 is 5 μm or more and less than 35 μm. By making the film substrate 12 thinner, the optical film 15 and the polarizing plate 5 can be made thinner, which can contribute to the thinning of the entire image display device 1.

The cured layer 13 may be composed of a single layer as shown in FIG. 1, but two or more layers may be laminated on the film substrate 12. For example, as shown in FIG. 2, the cured layer 13 may be configured by laminating a first cured layer 13a and a second cured layer 13b from the film base 12 side. Thus, by laminating a plurality of hardened layers 13, the scratch resistance can be improved, and the surface protection of the polarizing plate 5 by the optical film 15 can be reliably achieved.

The optical film 14 is provided to protect the back surface of the polarizing plate 5. The optical film 14 may be made of the same material as the film base 12 (for example, a cellulose film), or may be made of other materials.

The film substrate 12 may be composed of a λ / 4 film. The λ / 4 film is a layer that imparts in-plane retardation of about ¼ of the wavelength to transmitted light, and in the present embodiment, the λ / 4 film is composed of a film that is obliquely stretched. The angle (crossing angle) formed between the slow axis of the λ / 4 film and the absorption axis of the polarizer 11 is 30 ° to 60 °, whereby the linearly polarized light from the polarizer 11 is converted into the λ / 4 film ( It is converted into circularly polarized light or elliptically polarized light by the film substrate 12).

Therefore, when an observer wears polarized sunglasses and observes a display image, the polarizing plate can be used regardless of how the transmission axis of the polarizer 11 (perpendicular to the absorption axis) and the transmission axis of the polarized sunglasses are misaligned. The light component parallel to the transmission axis of the polarized sunglasses contained in the light emitted from 5 (circularly polarized light or elliptically polarized light) can be guided to the eyes of the observer. Thereby, it can suppress that it becomes difficult to see a display image with the angle to observe. In addition, even when the observer does not wear polarized sunglasses, since it is circularly polarized light or elliptically polarized light that is emitted from the polarizing plate 5 and incident on the observer's eyes, linearly polarized light is directly incident on the observer's eyes. Compared to the above, the burden on the eyes of the observer can be reduced.

The film substrate 12 may contain a hindered amine compound. The optical film 15 having the cured layer 13 formed on the film substrate 12 is adhered (UV adhesion) to the polarizer 11 by, for example, ultraviolet irradiation. By this UV irradiation, the film substrate 12 and the cured layer 13 are bonded to each other. The adhesiveness (light-resistant adhesiveness) may deteriorate. However, when the film base 12 contains a hindered amine compound, the above light-resistant adhesion can be improved.

The film substrate 12 is a specific polymer containing a specific organic acid, a specific phenol compound, or a main chain containing a benzene ring in order to suppress deterioration of the polarizer 11 under high temperature and high humidity or high temperature and low humidity. It may contain.

The details of the above hindered amine compounds and specific organic acids will be described later.

The polarizing plate 6 includes a polarizer 21 that transmits predetermined linearly polarized light, an optical film 22 that is disposed on the liquid crystal cell 4 side of the polarizer 21, and an optical that is disposed on the opposite side of the polarizer 21 from the liquid crystal cell 4. The film 23 is laminated. The polarizer 21 is disposed so that the transmission axis is perpendicular to the polarizer 11 (crossed Nicol state). The optical films 22 and 23 are provided to protect the front and back surfaces of the polarizing plate 6, but they may be made of the same material as the film substrate 12 of the polarizing plate 5 (for example, a cellulose film). It may be made of other materials.

In addition, the above-described optical film 15 can be used for purposes other than the polarizing plate. In this case, the cured layer 13 may be provided on both surfaces of the film substrate 12. Therefore, in the optical film 15, it can be said that the cured layer 13 may be formed on at least one surface of the film substrate 12.

[Optical film]
Hereinafter, the detail of the optical film 15 mentioned above is demonstrated.

(Cured layer)
<Active energy ray-curable resin (A)>
The cured layer of this embodiment has at least one active energy in which the maximum number of atoms arranged in a straight line as a spacer connecting two active energy groups is 8 or more, and the spacer does not include a ring structure. It contains a linear curable resin (A).

The active energy group is a reactive group that can be cured by active energy rays such as ultraviolet rays, electron beams, and heat, and specifically includes an acryloyl group, an epoxide, an oxetane, an isocyanate group, and a vinyl group.

The active energy ray-curable resin is a resin that is cured through a crosslinking reaction by irradiation with active energy rays (also referred to as active rays) such as ultraviolet rays and electron beams. As the active energy ray curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used. Examples of the ethylenically unsaturated double bond group include polymerizable functional groups such as (meth) acryloyl group, vinyl group, styryl group and allyl group. Among them, (meth) acryloyl group and —C (O) OCH═ CH ₂ is preferred.

In this embodiment, the active energy ray-curable resin (A) is preferably an acrylate from the viewpoint of reactivity. For example, alkyl acrylate, polyethylene glycol acrylate, methoxy polyethylene glycol acrylate, polypropylene acrylate, methoxy polypropylene glycol acrylate, polytetramethylene glycol acrylate, polyethylene glycol and polypropylene glycol acrylate (block type), polyethylene glycol and polypropylene glycol acrylate (random type), (Alkoxylated) trimethylolpropane acrylate, alkoxylated glycerin acrylate, pentaerythritol acrylate, alkoxylated pentaerythritol acrylate, (alkoxylated) ditrimellirol propane acrylate, alkoxylated dipentaerythritol acrylate, alkyl urethane An acrylate etc. are mentioned. Among these, from the viewpoint of low moisture permeability and bleed-out, the active energy ray-curable resin (A) is preferably a resin with fewer heteroatoms and a resin having two or more functional groups.

In the present embodiment, as the active energy ray-curable resin (A), for the reasons described above, the maximum number of atoms arranged in a straight line as a spacer connecting two active energy groups is 8 or more, and the spacer The resin does not contain a ring structure. Hereinafter, although the specific compound of such active energy ray curable resin (A) is shown, this invention is not limited to these. In the structural formulas of the following compounds, a portion surrounded by a broken line represents an active energy group. A portion surrounded by a solid line functions as a spacer connecting two active energy groups, and indicates a portion where the number of atoms arranged in a straight line as the spacer is maximized.

<Compound (B) having a ring structure and pKa ₁ of 1.0 or more and 7.0 or less>
The hardened layer contains at least one compound (B) having a ring structure and having a first acid dissociation constant pKa ₁ of 1.0 or more and 7.0 or less.

The acid dissociation constant is one of the indexes for quantitatively expressing the strength of the acid. The smaller the pKa value, the stronger the acid. The first acid dissociation constant pKa ₁ represents an acid dissociation constant in the first dissociation (first-stage dissociation) of a polyvalent acid.

Examples of the compound (B) having a ring structure and having the first acid dissociation constant pKa ₁ in the above range include carboxylic acid-containing additives, barbituric acid compounds, and rosin compounds.

<< Carboxylic acid-containing additive >>
As the carboxylic acid-containing additive, a compound represented by the following general formula is preferable.

A is any one of hydrogen, methyl group, ethyl group, hydroxyl group, amino group, methoxy group, ethoxy group, and carboxylic acid group. However, the additive contains one or more carboxylic acid groups. L is nothing but any of the following structures.

Specific examples of the carboxylic acid-containing additive include, for example, benzoic acid, 2-carboxyphenyl salicylate, 4-biphenylacetic acid, biphenyl-4-carboxylic acid, biphenyl-4-carboxylic acid, o-benzoylbenzoic acid, 2,2 '-Biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, phthalic acid, 1,3,5-benzenetricarboxylic acid, diphenylacetic acid, cyclohexylcarboxylic acid, 1,3-adamantanedicarboxylic acid, triphenylacetic acid, N- ( 2,6-diethylphenylcarbamoylmethyl) iminodiacetic acid, N-benzyliminodiacetic acid, terephthalic acid, isophthalic acid, orthophthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid Acid, 1,5-naphthalenedicarboxylic acid, diph Nonoxyethanedicarboxylic acid, diphenylsulfonecarboxylic acid, anthracenedicarboxylic acid, 1,3-cyclopentanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, etc. Can be mentioned.

《Barbituric acid compound》
As the barbituric acid-based compound, a compound represented by the following general formula (G) is preferable.

In General Formula (G), R ²⁶ represents an alkyl group, an alkenyl group, or an aryl group, R ²⁷ and R ²⁸ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, or a heteroaryl group, R ²⁹ represents a hydrogen atom. R ²⁶ , R ²⁷ and R ²⁸ may each independently have a substituent.

R ²⁶ is preferably an alkyl group having 1 to 20 carbon atoms (including a cycloalkyl group), an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and an alkyl group having 1 to 12 carbon atoms. More preferably an alkenyl group having 2 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms, an alkyl group having 1 to 12 carbon atoms (including a cycloalkyl group), It is more preferably an alkenyl group having 2 to 10 carbon atoms or an aryl group having 6 to 18 carbon atoms, an alkyl group having 1 to 8 carbon atoms (including a cycloalkyl group), an alkenyl group having 2 to 5 carbon atoms, An aryl group having 6 to 12 carbon atoms is particularly preferable, and an alkyl group having 1 to 6 carbon atoms (including a cycloalkyl group) or an aryl group having 6 to 12 carbon atoms is most preferable. There.

Among these, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, a phenyl group or a naphthyl group is more preferable, and a methyl group, a cyclohexyl group or a phenyl group is most preferable.

R ²⁷ and R ²⁸ are each independently an alkyl group having 1 to 20 carbon atoms (including a cycloalkyl group), an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 6 to 20 carbon atoms. A heteroaryl group is more preferably an alkyl group having 1 to 12 carbon atoms (including a cycloalkyl group), an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. It is more preferably an alkyl group having 1 to 12 (including a cycloalkyl group), an alkenyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 18 carbon atoms, and an alkyl group having 1 to 8 carbon atoms (cycloalkyl An alkenyl group having 2 to 5 carbon atoms or an aryl group having 6 to 12 carbon atoms, and an alkyl group having 1 to 6 carbon atoms (including a cycloalkyl group). Most preferably, or an aryl group having 6 to 12 carbon atoms.

Among them, a methyl group, an ethyl group, a propyl group, a cyclohexyl group, a phenyl group, or a naphthyl group is most preferable, and a methyl group, an ethyl group, a cyclohexyl group, or a phenyl group is particularly preferable.

The substituent which R ²⁶ may have is not particularly limited as long as it is not contrary to the gist of the present invention, but is preferably a halogen atom, an alkyl group or an aryl group, and preferably a halogen atom, a carbon number It is more preferably a 1 to 6 alkyl group or an aryl group having 6 to 12 carbon atoms, and particularly preferably a chlorine atom, a methyl group or a phenyl group.

The substituent which R ²⁷ and R ²⁸ may have is not particularly limited as long as it does not contradict the gist of the present invention, but is preferably an aryl group having 6 to 12 carbon atoms, More preferably.

As the compound represented by the above general formula (G), a compound represented by the following general formula (Ga) can be used. The compound represented by the general formula (Ga) is preferable from the viewpoint of suppressing volatilization during film formation.

In the general formula (Ga), L ¹ to L ³ each independently represents a single bond or an alkylene group, and Ar ¹ to Ar ³ each independently represents an aryl group having 6 to 20 carbon atoms. .

L ¹ to L ³ each independently represents a single bond or a divalent linking group having 1 or more carbon atoms. L ¹ to L ³ are more preferably a single bond or an alkylene group having 1 to 6 carbon atoms, more preferably a single bond, a methylene group or an ethylene group, and a single bond or a methylene group. Particularly preferred. The divalent linking group may have a substituent, and the substituent is synonymous with the substituent that Ar ¹ , Ar ² , and Ar ³ described later may have.

Ar ¹ to Ar ³ are preferably a phenyl group or a naphthyl group, and more preferably a phenyl group. Ar ¹ to Ar ³ may have a substituent or may not have a substituent. When it has a substituent, it is preferable that the said substituent does not have a ring structure.

The substituent that Ar ¹ , Ar ² , and Ar ³ have is not particularly limited, and may be an alkyl group (preferably having 1 to 10 carbon atoms such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1- Ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl groups (preferably having 2 to 20 carbon atoms, such as vinyl, allyl, oleyl, etc.), alkynyl groups (preferably having 2 to 20 carbon atoms). For example, ethynyl, butadiynyl, phenylethynyl, etc.), cycloalkyl groups (preferably having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), aryl groups (preferably having 6 to 6 carbon atoms). 26, for example, phenyl, 1-naphthyl, 4-methoxyphenyl, 2-chlorophene , 3-methylphenyl, etc.), a heterocyclic group (preferably a heterocyclic group having from 0 to 20 carbon atoms, wherein the ring-constituting hetero atom is preferably an oxygen atom, nitrogen atom or sulfur atom, and a 5- or 6-membered ring is a benzene ring Or may be condensed with a heterocyclic ring, and the ring may be a saturated ring, an unsaturated ring, or an aromatic ring. For example, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzoimidazolyl, 2- Thiazolyl, 2-oxazolyl, etc.), alkoxy groups (preferably having 1 to 20 carbon atoms, such as methoxy, ethoxy, isopropyloxy, benzyloxy, etc.), aryloxy groups (preferably having 6 to 26 carbon atoms, such as phenoxy) 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), an alkylthio group (preferably having 1 to 20 carbon atoms such as methylthio , Ethylthio, isopropylthio, benzylthio, etc.), arylthio groups (preferably having 6 to 26 carbon atoms, such as phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc.), acyl groups (alkylcarbonyl groups) , An alkenylcarbonyl group, an arylcarbonyl group, and a heterocyclic carbonyl group, preferably having 20 or less carbon atoms, such as acetyl, pivaloyl, acryloyl, metachloroyl, benzoyl, nicotinoyl, etc.), an aryloylalkyl group, an alkoxycarbonyl group (preferably Has 2 to 20 carbon atoms, such as ethoxycarbonyl, 2-ethylhexyloxycarbonyl, etc., an aryloxycarbonyl group (preferably having 7 to 20 carbon atoms, such as phenyloxycarbonyl, naphthyloxycarbo Etc.), amino groups (including amino groups, alkylamino groups, arylamino groups and heterocyclic amino groups, preferably having 0 to 20 carbon atoms, such as amino, N, N-dimethylamino, N, N-diethylamino N-ethylamino, anilino, 1-pyrrolidinyl, piperidino, morpholinyl, etc.), sulfonamide groups (preferably having 0 to 20 carbon atoms, such as N, N-dimethylsulfonamide, N-phenylsulfonamide, etc.), sulfamoyl Groups (preferably having 0 to 20 carbon atoms such as N, N-dimethylsulfamoyl, N-phenylsulfamoyl, etc.), acyloxy groups (preferably having 1 to 20 carbon atoms such as acetyloxy, benzoyloxy, etc. ), A carbamoyl group (preferably having 1 to 20 carbon atoms, such as N, N-dimethylcarbamoyl, N Phenylcarbamoyl, etc.), acylamino groups (preferably having 1 to 20 carbon atoms, such as acetylamino, acryloylamino, benzoylamino, nicotinamide, etc.), cyano groups, hydroxyl groups, mercapto groups, or halogen atoms (eg, fluorine atoms, chlorines) Atom, bromine atom, iodine atom, etc.).

The above substituents that Ar ¹ , Ar ² , and Ar ³ may have may further have the above substituents.

Here, among the above substituents that each of Ar ¹ , Ar ² , and Ar ³ may have, an alkyl group, an aryl group, an alkoxy group, and an acyl group are preferable.

The molecular weight of the compound represented by the general formula (G) or (Ga) is preferably 250 to 1200, and more preferably 300 to 800. If the molecular weight is 250 or more, volatilization from the film is suppressed, and if it is 1200 or less, the compatibility with the cellulose acylate is excellent, and thus the transparency of the film is good.

Specific examples of the compound represented by the general formula (G) or (Ga) are shown below, but the present invention is not limited thereto. In the following exemplary compounds, Me represents a methyl group.

It is known that the compound represented by the above general formula (G) can be synthesized using a synthesis method of barbituric acid in which a urea derivative and a malonic acid derivative are condensed. Barbituric acid having two substituents on N can be obtained by heating N, N 'disubstituted urea and malonic acid chloride, or by combining malonic acid and an activating agent such as acetic anhydride. For example, Journal of the American Chemical Society, 61, 1015 (1939), Journal of Medicinal Chemistry, 54, 2409 (2011), Tetrahedron 99, Vol. ), Methods described in WO2007 / 150011 and the like can be preferably used.

The malonic acid used for the condensation may be either unsubstituted or substituted, and if malonic acid having a substituent corresponding to R ⁵ is used, by constructing barbituric acid, the general formula (G ) Can be synthesized. Further, when an unsubstituted malonic acid and a urea derivative are condensed, a 5-position unsubstituted barbituric acid is obtained. By modifying this, the compound represented by the general formula (G) can be synthesized. Good.

In addition, the synthesis method of the compound represented by the general formula (G) is not limited to the above method.

<Rosin compounds>
Examples of the rosin compound include the following structural formulas.

Of the above compounds, KE-604 and KE-610 are commercially available from Arakawa Chemical Industries, Ltd. Similarly, KR-85, KR-612, and KR-614 are commercially available from Arakawa Chemical Industries, Ltd. as rosins, and KR-140 as a polymerized rosin. A mixture of abietic acid, dehydroabietic acid, and parastrinic acid is commercially available from Harima Kasei Co., Ltd. as G-7 and Hartle RX.

Among the compounds (B) described above, structural formulas of representative compounds (B) are shown below.

(Sub resin)
When the curable resin (A) described above is a main resin, the cured layer may contain a sub-resin in addition to the main resin within a range that does not impair the effects of the present embodiment in order to increase the hardness. The sub-resin includes a compound having a ring structure in the molecule and having an active energy group. Examples of such a sub-resin include a compound having a cyclic aliphatic hydrocarbon group and having 3 or more ethylenically unsaturated double bond groups in the molecule.

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

Examples of the ethylenically unsaturated double bond group include polymerizable functional groups such as (meth) acryloyl group, vinyl group, styryl group and allyl group. Among them, (meth) acryloyl group and —C (O) OCH═ CH ₂ is preferred. Particularly preferably, a compound containing three or more (meth) acryloyl groups in one molecule can be used as the sub-resin.

In a compound having a cycloaliphatic hydrocarbon group and having 3 or more ethylenically unsaturated double bond groups in the molecule, the cycloaliphatic hydrocarbon group and the ethylenically unsaturated double bond group are linked. It is constituted by bonding through a group. As the linking group, a single bond, an alkylene group having 1 to 6 carbon atoms which may be substituted, an amide group which may be substituted at the N-position, a carbamoyl group which may be substituted at the N-position, an ester group, Examples include oxycarbonyl groups, ether groups, and the like, and groups obtained by combining these.

As the compound, it is preferable to use a compound represented by any one of the following general formulas.

In general formula (I-1), L represents a trivalent linking group, L ′ represents a divalent linking group, and R, R ′, and R ″ each independently represent an ethylenically unsaturated double bond. Represents a group having n represents an integer of 1 to 3.

In general formula (I-2), L represents a divalent linking group, L ′ represents a trivalent linking group, and R, R ′, and R ″ each independently represent an ethylenically unsaturated double bond. Represents a group having n represents an integer of 1 to 3.

In general formula (I-3), L and L ′ each independently represent a trivalent linking group, and R, R ′, R ″, and R ′ ″ each independently represent an ethylenically unsaturated double group. A group having a bond is represented. n represents an integer of 1 to 3.

In general formula (II-1), L represents a trivalent linking group, L ′ represents a divalent linking group, and R, R ′, and R ″ each independently represent an ethylenically unsaturated double bond. Represents a group having n represents an integer of 1 to 2.

In general formula (II-2), L represents a trivalent linking group, L ′ represents a divalent linking group, and R, R ′, and R ″ each independently represents an ethylenically unsaturated double bond. Represents a group having

In general formula (II-3), L and L ′ each independently represent a trivalent linking group, and R, R ′, R ″, and R ′ ″ each independently represent an ethylenically unsaturated double group. A group having a bond is represented. n represents an integer of 1 to 2.

In general formula (III-1), L represents a trivalent linking group, L ′ represents a divalent linking group, and R, R ′, and R ″ each independently represent an ethylenically unsaturated double bond. Represents a group having n represents an integer of 1 to 2.

In general formula (III-2), L represents a divalent linking group, L ′ represents a trivalent linking group, and R, R ′, and R ″ each independently represent an ethylenically unsaturated double bond. Represents a group having n represents an integer of 1 to 2.

In general formula (III-3), L and L ′ each independently represent a trivalent linking group, and R, R ′, R ″, and R ′ ″ each independently represent an ethylenically unsaturated double group. A group having a bond is represented. n represents an integer of 1 to 2.

In general formula (IV-1), L, L ′, and L ″ each independently represent a divalent linking group, and R, R ′, and R ″ each independently represent an ethylenically unsaturated double bond. Represents a group having

In general formula (IV-2), L, L ′, and L ′ ″ each independently represent a trivalent linking group, and R, R ′, R ″, R ′ ″, R ″ ″. And R ″ ′ ″ each independently represents a group having an ethylenically unsaturated double bond.

Preferred specific examples of the compound having a cyclic aliphatic hydrocarbon group and having three or more ethylenically unsaturated double bond groups in the molecule are described below.

(Photopolymerization initiator)
The cured layer preferably contains a photopolymerization initiator to accelerate the curing of the actinic radiation curable resin. The content of the photopolymerization initiator is preferably such that the photopolymerization initiator: active ray curable resin = 20: 100 to 0.01: 100 in terms of mass ratio. Specific examples of the photopolymerization initiator include alkylphenone series, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone and the like, and derivatives thereof. It is not something. Commercially available products may be used as the photopolymerization initiator, and preferred examples include Irgacure 184, Irgacure 907, and Irgacure 651 manufactured by BASF Japan.

(Fine particles)
The hardened layer may contain fine particles. Although it does not restrict | limit especially as microparticles | fine-particles, A silica, an alumina, a zirconia, a titanium oxide, antimony pentoxide etc. are mentioned, Preferably it is a silica. The silica fine particles may be hollow particles having cavities inside. Fine particles coated with a polymer silane coupling agent are particularly preferred because they exhibit good mechanical properties. The content is preferably a fine particle: active ray curable resin = 0.1: 100 to 400: 100.

(Polymer silane coupling agent)
The polymer silane coupling agent refers to a reaction product of a polymerizable monomer and a silane coupling agent (reactive silane compound). Such a polymer silane coupling agent can be obtained, for example, according to the method for producing a reaction product of a polymerizable monomer and a reactive silane compound disclosed in JP-A-11-116240.

Specific examples of the polymerizable monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid-n-propyl, (meth) acrylic acid isopropyl, (meth) -N-butyl, isobutyl (meth) acrylate, (meth) acrylic acid-n-hexyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid-n-heptyl, (meth) acrylic acid-n-octyl, ( 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, phenyl (meth) acrylate, toluyl (meth) acrylate, benzyl (meth) acrylate , 2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, (meth) acrylic acid -Hydroxyethyl, 2-hydroxypropyl (meth) acrylate, stearyl (meth) acrylate, glycidyl (meth) acrylate, 2-aminoethyl (meth) acrylate, ethylene oxide adduct of (meth) acrylic acid, (Meth) acrylic acid trifluoromethyl methyl, (meth) acrylic acid 2-trifluoromethyl ethyl, (meth) acrylic acid 2-perfluoroethyl ethyl, (meth) acrylic acid 2-perfluoroethyl-2-perfluorobutyl Ethyl, 2-perfluoroethyl (meth) acrylate, perfluoromethyl (meth) acrylate, difluorofluoromethyl methyl (meth) acrylate, 2-perfluoromethyl-2-perfluoroethyl methyl (meth) acrylate, (Meth) acrylic acid 2-perfluorohexylethyl (Meth) acrylic acid-based monomers such as (meth) acrylic acid 2-perfluorodecylethyl and (meth) acrylic acid 2-perfluorohexadecylethyl; styrene, vinyltoluene, α-methylstyrene, chlorostyrene, styrenesulfonic acid and Styrene monomers such as salts thereof; fluorine-containing vinyl monomers such as perfluoroethylene, perfluoropropylene, and vinylidene fluoride; silicon-containing vinyl monomers such as vinyltrimethoxysilane and vinyltriethoxysilane; maleic anhydride, maleic acid, Monoalkyl and dialkyl esters of maleic acid; fumaric acid, monoalkyl and dialkyl esters of fumaric acid; maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexyluma Nitrile group-containing vinyl monomers such as imide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenylmaleimide, cyclohexylmaleimide; amide group-containing vinyl monomers such as acrylamide and methacrylamide; vinyl acetate, vinyl propionate, vinyl pivalate, benzoate Vinyl esters such as vinyl acid and vinyl cinnamate; Alkenes such as ethylene and propylene; Conjugated dienes such as butadiene and isoprene; Vinyl chloride, vinylidene chloride, allyl chloride, allyl alcohol, acrylic resin monomers; Pentaerythritol triacrylate , Pentaerythritol tetraacrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetraacrylate, ditrimethylolpropane Tora (meth) acrylate, dipentaerythritol hexaacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl acrylate, n-stearyl acrylate, 1,6 -Hexanediol dimethacrylate, perfluorooctylethyl methacrylate, trifluoroethyl methacrylate, urethane acrylate and the like and mixtures thereof.

As the reactive silane compound, an organosilicon compound represented by the following formula (1) is preferably used.
XR-Si (OR) ₃ (1)
(In the formula, R represents an organic group having 1 to 10 carbon atoms selected from a substituted or unsubstituted hydrocarbon group. X represents a (meth) acryloyl group, an epoxy group (glycid group), a urethane group, an amino group, One or more functional groups selected from fluoro groups.)

Specific examples of the organosilicon compound represented by the formula (1) include 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3,3-trifluoropropyldimethoxysilane, β- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxymethyltrimethoxysilane, γ-glycidoxymethyltriethoxysilane, γ-glycidoxyethyltrimethoxysilane, γ-glycidoxyethyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, γ- (β-glycidoxyethoxy) Propyltrimethoxysilane, γ- (meth) acrylooxymethyltrimethoxy Lan, γ- (meth) acrylooxymethyltrioxysilane, γ- (meth) acrylooxyethyltrimethoxysilane, γ- (meth) acryloxyethyltriethoxysilane, γ- (meth) acryloxypropyl Trimethoxysilane, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, 3-ureidoisopropylpropyltriethoxy Silane, perfluorooctylethyltrimethoxysilane, perfluorooctylethyltriethoxysilane, perfluorooctylethyltriisopropoxysilane, trifluoropropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldimethoxysila , N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, and the like, and mixtures thereof.

Polymeric silane coupling agent is prepared by reacting a polymerizable monomer with a reactive silane compound. Specifically, an organic solvent solution in which a reactive silane compound is mixed in an amount of 0.5 to 20 parts by weight, further 1 to 10 parts by weight with respect to 100 parts by weight of the polymerizable monomer is prepared, and polymerization is started. It can be obtained by adding an agent and heating.

(Method for preparing polymer silane coupling agent coated fine particles)
Specifically, the polymer silane coupling agent-coated fine particles can be prepared by adding a polymer silane coupling agent to a fine particle organic solvent dispersion and coating the fine particles with the polymer silane coupling agent in the presence of an alkali. The average particle diameter of the resulting polymer silane coupling agent-coated fine particles is preferably 5 to 500 nm, more preferably 10 to 200 nm, from the viewpoint of securing optical properties when used in an optical film.

The content of the polymer silane coupling agent-coated fine particles in the cured layer is preferably 0.5 to 80 parts by mass, more preferably 1 to 60 parts by mass as the solid content, from the viewpoint of securing the film strength of the cured layer. .

(Conductive agent)
The hardened layer may contain a conductive agent in order to impart antistatic properties. Preferred conductive agents include metal oxide particles or π-conjugated conductive polymers. An ionic liquid is also preferably used as the conductive compound.

(Additive)
The cured layer may contain a fluorine-siloxane graft compound, a fluorine compound, a silicone compound, or a compound having an HLB value of 3 to 18 from the viewpoint of improving the coating property. The hydrophilicity can be easily controlled by adjusting the types and amounts of these additives. The HLB value is Hydrophile-Lipophile-Balance, that is, a hydrophilic-lipophilic balance, and is a value indicating the hydrophilicity or lipophilicity of a compound. The smaller the HLB value, the higher the lipophilicity, and the higher the value, the higher the hydrophilicity. The HLB value can be obtained by the following calculation formula.
HLB = 7 + 11.7Log (Mw / Mo)
In the formula, Mw represents the molecular weight of the hydrophilic group, Mo represents the molecular weight of the lipophilic group, and Mw + Mo = M (molecular weight of the compound). Alternatively, according to the Griffin method, HLB value = 20 × total formula weight of hydrophilic part / molecular weight (J. Soc. Cosmetic Chem., 5 (1954), 294) and the like.

Specific compounds of compounds having an HLB value of 3 to 18 are listed below, but are not limited thereto. Figures in parentheses indicate HLB values. Made by Kao Corporation: Emulgen 102KG (6.3), Emulgen 103 (8.1), Emulgen 104P (9.6), Emulgen 105 (9.7), Emulgen 106 (10.5), Emulgen 108 (12. 1), Emulgen 109P (13.6), Emulgen 120 (15.3), Emulgen 123P (16.9), Emulgen 147 (16.3), Emulgen 210P (10.7), Emulgen 220 (14.2) , Emulgen 306P (9.4), Emulgen 320P (13.9), Emulgen 404 (8.8), Emulgen 408 (10.0), Emulgen 409PV (12.0), Emulgen 420 (13.6), Emulgen 430 (16.2), Emulgen 705 (10.5), Emulgen 707 (12.1), Emulgen 7 9 (13.3), Emulgen 1108 (13.5), Emulgen 1118S-70 (16.4), Emulgen 1135S-70 (17.9), Emulgen 2020G-HA (13.0), Emulgen 2025G (15. 7), Emulgen LS-106 (12.5), Emulgen LS-110 (13.4), Emulgen LS-114 (14.0), manufactured by Nissin Chemical Industry Co., Ltd .: Surfynol 104E (4), Surfynol 104H (4), Surfinol 104A (4), Surfinol 104BC (4), Surfinol 104DPM (4), Surfinol 104PA (4), Surfinol 104PG-50 (4), Surfinol 104S (4), Surfi Knoll 420 (4), Surfynol 440 (8), Surfynol 46 (13), Surfynol 485 (17), Surfynol SE (6), Shin-Etsu Chemical Co., Ltd.: X-22-4272 (7), X-22-6266 (8).

The fluorine-siloxane graft compound refers to a copolymer compound obtained by grafting polysiloxane and / or organopolysiloxane containing siloxane and / or organosiloxane alone on at least a fluorine resin. Such a fluorine-siloxane graft compound can be prepared by a method as described in Examples described later. Alternatively, examples of commercially available products include ZX-022H, ZX-007C, ZX-049, and ZX-047-D manufactured by Fuji Chemical Industry Co., Ltd.

Examples of the fluorine-based compound include Megafac series (F-477, F-487, F-569, etc.) manufactured by DIC Corporation, OPTOOL DSX, OPTOOL DAC, etc. manufactured by Daikin Industries, Ltd.

Examples of silicone compounds are Shin-Etsu Chemical Co., Ltd .: KF-351, KF-352, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-618, KF-6011, KF. -6015, KF-6004, manufactured by Big Chemie Japan KK: BYK-UV3576, BYK-UV3535, BYK-UV3510, BYK-UV3505, BYK-UV3500, BYK-UV3510, and the like. These components are preferably added in a range of 0.005 parts by mass or more and 10 parts by mass or less with respect to the solid component in the cured layer composition. Two or more kinds of these components may be added as long as the total additive amount is in the range of 0.005 parts by mass or more and 10 parts by mass or less.

(UV absorber)
The hardened layer may contain an ultraviolet absorber described in the cellulose ester film described later. As a structure of the film in the case of containing an ultraviolet absorber, when the cured layer is composed of two or more layers, the cured layer in contact with the film substrate preferably contains the ultraviolet absorber.

The content of the ultraviolet absorber is preferably such that the mass ratio is ultraviolet absorber: curable resin = 0.01: 100 to 20: 100.

(solvent)
The cured layer is a component that forms the cured layer described above, diluted with a solvent that swells or partially dissolves the film substrate, and is applied as a cured layer composition on the film substrate in the following manner, dried. It is preferable to provide it by curing.

Solvents include ketones (methyl ethyl ketone, acetone, etc.) and / or acetate esters (methyl acetate, ethyl acetate, butyl acetate, etc.), alcohols (ethanol, methanol, normal propanol, isopropanol), propylene glycol monomethyl ether, cyclohexanone, methyl isobutyl ketone. Etc. are preferable. The coating amount of the cured layer composition is suitably an amount that results in a wet film thickness of 0.1 to 80 μm, and preferably an amount that results in a wet film thickness of 0.5 to 30 μm. The dry film thickness is in the range of an average film thickness of 0.01 to 20 μm, preferably in the range of 1 to 15 μm. More preferably, it is in the range of 2 to 12 μm.

As a method for applying the cured layer composition, a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method can be used.

(Laminated)
The cured layer is preferably composed of two or more layers from the viewpoint of surface hardness (abrasion resistance). When the cured layer is composed of two or more layers, it is preferable from the viewpoint of surface hardness that the outermost surface layer contains the above-described polymer silane coupling agent-coated fine particles. The content of the polymer silane coupling agent-coated fine particles is preferably in the range of polymer silane coupling agent-coated fine particles: curable resin = 0.1: 100 to 200: 100 by mass ratio.

When two or more cured layers are provided, the thickness of the cured layer in contact with the film substrate is preferably in the range of 0.01 to 50 μm, and the thickness of the second cured layer is in the range of 0.01 to 25 μm. It is preferable that

Two or more layers may be formed by simultaneous multilayers. The simultaneous multi-layer is to form a hardened layer by applying two or more hardened layers on a base material without going through a drying step.

In order to laminate the second hardened layer on the first hardened layer without going through a drying process, the layers are stacked one after another with an extrusion coater or simultaneously with a slot die having a plurality of slits. Can be done.

(Curing layer formation method)
After applying the cured layer composition, it may be dried and cured (irradiated with actinic radiation (also referred to as UV curing treatment)), and if necessary, may be heat treated after UV curing. The heat treatment temperature after UV curing is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and particularly preferably 120 ° C. or higher. By performing the heat treatment after UV curing at such a high temperature, a cured layer having excellent film strength can be obtained.

Drying is preferably performed at a temperature of 30% or more in the rate of drying section. More preferably, the temperature of the decreasing rate drying section is 50 ° C. or higher.

In general, it is known that the drying process changes from a constant state to a gradually decreasing state when drying starts. A section in which the drying speed is constant is called a constant rate drying section, and a section in which the drying speed decreases is called a decreasing rate drying section.

As a light source for UV curing treatment, any light source that generates ultraviolet rays can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used.

Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually in the range of 50 to 1000 mJ / cm ² , preferably in the range of 50 to 300 mJ / cm ² . In the UV curing treatment, oxygen removal (for example, replacement with an inert gas such as nitrogen purge) can be performed to prevent reaction inhibition by oxygen. The cured state of the surface can be controlled by adjusting the removal amount of the oxygen concentration.

When irradiating actinic rays, it is preferably performed while applying tension in the transport direction of the film, more preferably while applying tension in the width direction. The tension to be applied is preferably 30 to 300 N / m. The method for applying tension is not particularly limited, and tension may be applied in the conveying direction on the back roller, or tension may be applied in the width direction or biaxial direction by a tenter. Thereby, a film having further excellent flatness can be obtained.

There may be at least one cured layer on the optical film, and it may be composed of a plurality of layers. Moreover, there may be a cured layer on both sides of the optical film.

(Back coat layer)
You may provide a backcoat layer in the surface on the opposite side to the side which provided the hardened layer of the optical film. The back coat layer is provided to correct curling caused by providing a hardened layer or other layers by coating or CVD. That is, the degree of curling can be balanced by imparting the property of being rounded with the surface on which the backcoat layer is provided facing inward. In addition, it is also preferable that the back coat layer is preferably applied also as an anti-blocking layer. In that case, fine particles may be added to the back coat layer coating composition to provide an anti-blocking function. preferable.

As fine particles added to the backcoat layer, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, and oxide. Mention may be made of indium, zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low haze, and silicon dioxide is particularly preferable. These fine particles are commercially available under the trade names of, for example, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, and TT600 (manufactured by Nippon Aerosil Co., Ltd.). . 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. Examples of the polymer fine particles include a silicone resin, a fluororesin, and an acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (manufactured by Toshiba Silicone Co., Ltd.) It is marketed by name and can be used.

Among these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a large anti-blocking effect while keeping haze low. The dynamic friction coefficient on the back side of the optical film used in this embodiment is preferably 0.9 or less, particularly preferably 0.1 to 0.9.

The fine particles contained in the backcoat layer are preferably contained in an amount of 0.1 to 50% by weight, more preferably 0.1 to 10% by weight, based on the binder. The increase in haze when the backcoat layer is provided is preferably 1% or less, more preferably 0.5% or less, and particularly preferably 0.0 to 0.1%.

Specifically, the backcoat layer is preferably formed by applying a composition containing a solvent that dissolves or swells the transparent resin film (film substrate). The solvent to be used may include a solvent to be dissolved and / or a solvent to be swollen in addition to a solvent to be swelled, a composition in which these are mixed at an appropriate ratio depending on the degree of curl of the transparent resin film and the type of resin What is necessary is just to form by the application quantity.

In order to enhance the curl prevention function, it is effective to increase the mixing ratio of the solvent for dissolving the solvent composition to be used and / or the solvent for swelling, and to decrease the ratio of the solvent not to be dissolved. This mixing ratio is preferably (solvent to be dissolved and / or solvent to be swollen) :( solvent to be dissolved) = 10: 0 to 0.3: 9.7. Examples of the solvent for dissolving or swelling the transparent resin film contained in such a mixed composition include dioxane, acetone, methyl ethyl ketone, N, N-dimethylformamide, methyl acetate, ethyl acetate, cyclohexane, diacetone alcohol, 1 , 3-dioxolane, N-methylpyrrolidone, propylene glycol monomethyl ether acetate, propylene carbonate, cyclopentanone, 3-pentanone, 1,2-dimethoxyethane, tetrahydrofuran, ethyl lactate, bis (2-methoxyethyl) ether, acetic acid 2 -Methoxyethyl, propylene glycol dimethyl ether, trichloroethylene, methylene chloride, ethylene chloride, tetrachloroethane, trichloroethane, chloroform and the like. Examples of the solvent that does not dissolve include methanol, ethanol, n-propyl alcohol, i-propyl alcohol, n-butanol, propylene glycol monomethyl ether, and hydrocarbons (toluene, xylene, cyclohexanol).

These coating compositions are preferably applied on the surface of the transparent resin film with a gravure coater, dip coater, reverse coater, wire bar coater, die coater, etc., with a wet film thickness of 1 to 100 μm, particularly 5 to 30 μm. Preferably there is. The back coat layer may contain a resin as a binder. Examples of the resin used as the binder for the backcoat layer include vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, vinyl acetate-vinyl alcohol copolymer, partially hydrolyzed vinyl chloride-vinyl acetate copolymer. Polymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, etc. Vinyl polymer or copolymer, nitrocellulose, cellulose acetate propionate (preferably acetyl group substitution degree 1.8-2.3, propionyl group substitution degree 0.1-1.0), diacetylcellulose, cellulose Cellulose derivatives such as acetate butyrate resin, maleic acid and / or Or acrylic acid copolymer, acrylic ester copolymer, acrylonitrile-styrene copolymer, chlorinated polyethylene, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin Rubber resins such as polyvinyl acetal resin, polyvinyl butyral resin, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, styrene-butadiene resin, butadiene-acrylonitrile resin, Examples thereof include, but are not limited to, silicone resins and fluorine resins. For example, as acrylic resins, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M-4003, M-4005, M-4006, M-4202, M-5000, M-5001, M-4501 (manufactured by Negami Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR-79, BR -80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105 BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118, etc. (Mitsubishi Rayon Co., Ltd.) acrylic and The methacrylic monomers such as various homopolymers and copolymers were prepared as raw materials are commercially available and can also be selected as appropriate preferred from among these. A cellulose resin layer such as diacetyl cellulose or cellulose acetate propionate is preferable.

The order of coating the backcoat layer may be before or after coating the cured layer on the side opposite to the backcoat layer of the optical film, but if the backcoat layer also serves as an anti-blocking layer, coat it first. It is desirable to do. Alternatively, the back coat layer can be applied twice or more before and after the coating of the hardened layer.

[Optical film characteristics]
(Surface shape)
The arithmetic average roughness Ra (JIS B0601: 2001) of the hardened layer is preferably in the range of 2 to 100 nm, particularly preferably in the range of 2 to 20 nm. By setting the arithmetic average roughness Ra within the above range, the visibility and the clearness are excellent. The arithmetic average roughness Ra is a value measured with an optical interference surface roughness meter (manufactured by ZYGO, NewView) according to JIS B0601: 2001.

(Haze)
The haze of the optical film is preferably in the range of 0.05% to 10% in view of visibility when used in an image display device. Haze can be measured according to JIS K7105 and JIS K7136.

(hardness)
About the hardness of an optical film, it is preferable that the pencil hardness which is a parameter | index of hardness is HB or more. If the pencil hardness is equal to or higher than HB, it is difficult to be damaged in the polarizing plate forming step. For pencil hardness, the cured optical layer was conditioned at a temperature of 23 ° C. and a relative humidity of 55% for 2 hours or more, and then the cured layer was JIS K5400 using a test pencil specified by JIS S 6006 under a load of 500 g. Is a value measured in accordance with the pencil hardness evaluation method defined by.

[Film base]
The film substrate is composed of a cellulose-based film. As a cellulose film, it is preferable that manufacture is easy, it is easy to adhere | attach with a hardened layer, and it is optically isotropic, for example, a cellulose ether film and a cellulose-ester film are mentioned, for example.

(Cellulose ether film)
The cellulose ether film is a film containing a cellulose ether resin composition (hereinafter also simply referred to as cellulose ether) as a main component. The cellulose ether is preferably one in which the hydroxyl group of cellulose is substituted with an alkoxy group having 4 or less carbon atoms. Specifically, it is preferable that the hydroxyl group of cellulose is substituted by any one of a methoxy group, an ethoxy group, a propoxy group, a butoxy group or a plurality of alkoxy groups. In particular, those in which the hydroxyl group of cellulose is substituted by a single or a plurality of alkoxy groups of methoxy group and ethoxy group are preferable. Among them, the degree of ethoxy substitution (DSet) is 1.8 or more and 2.8 or less, more preferably DSet is 1 Ethyl cellulose satisfying .8 or more and 2.5 or less can be preferably used.

In the present specification, DSet represents the average ethoxylation of the three hydroxyl groups present at the 2, 3, and 6 positions in the cellulose molecule. It shows that the hydroxyl group is ethoxylated. The degree of substitution at each position may be equal or may be biased to any position. The degree of ether substitution can be quantified by the method described in ASTM D4794-94.

If the degree of substitution is less than 1.8, the type of solvent that can be dissolved alone is limited, and the water absorption rate of the film increases and the dimensional stability tends to decrease. Even if the degree of substitution exceeds 2.8, not only the type of solvent to be dissolved is limited, but the resin itself tends to be expensive.

Cellulose ether can be produced by a method known per se. For example, it can be produced by treating cellulose with a strong caustic soda solution to make alkali cellulose, reacting it with methyl chloride or ethyl chloride, and etherifying it.

The weight average molecular weight of the cellulose ether is preferably 100,000 to 400,000, more preferably 130,000 to 300,000, and further preferably 150,000 to 250,000. When the molecular weight is larger than 400,000, not only the solubility in the solvent is lowered, but also the viscosity of the resulting solution becomes too high, not suitable for the solvent casting method, making thermoforming difficult, and the transparency of the film is lowered. Tend to cause such problems. On the other hand, when the molecular weight is smaller than 100,000, the mechanical strength of the resulting film tends to decrease.

As the cellulose ether, cellulose ether produced from a single raw material may be used, or two or more kinds of cellulose ethers having different raw materials may be used in combination.

(Cellulose ester film)
The cellulose ester film is a film containing a cellulose ester resin composition as a main component. In the present specification, the cellulose ester is a part or all of hydrogen atoms of hydroxyl groups (—OH) at the 2nd, 3rd and 6th positions in the β-1,4 bonded glucose units constituting cellulose. Refers to a cellulose acylate resin substituted with an acyl group.

Examples of commercially available cellulose ester films include Konica Minoltack KC8UX, KC4UX, KC8UY, KC4UAY, KC6UA, KC4UA, KC2UA, KC4UE and KC4UZ (manufactured by Konica Minolta, Inc.). The refractive index of the cellulose ester film is preferably 1.45 to 1.55. The refractive index can be measured according to JIS K7142-2008.

The cellulose ester is preferably a lower fatty acid ester of cellulose. Lower fatty acid means a fatty acid having 6 or less carbon atoms. Examples of the lower fatty acid ester of cellulose include, for example, cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose propionate, cellulose butyrate and the like, and mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate. it can. Particularly preferably used lower fatty acid esters of cellulose are cellulose diacetate, cellulose triacetate, and cellulose acetate propionate. These cellulose esters can be used alone or in combination.

Cellulose diacetate preferably has an average degree of acetylation (bound acetic acid amount) of 51.0% to 56.0%. Commercially available products include L20, L30, L40, and L50 manufactured by Daicel Corporation, and Ca398-3, Ca398-6, Ca398-10, Ca398-30, and Ca394-60S manufactured by Eastman Chemical Japan Co., Ltd. .

The cellulose triacetate preferably has an average degree of acetylation (bound acetic acid amount) of 54.0 to 62.5%, and more preferably cellulose triacetate having an average degree of acetylation of 58.0 to 62.5%. is there.

The cellulose triacetate preferably contains cellulose triacetate A and cellulose triacetate B. Cellulose triacetate A is a cellulose triacetate having a number average molecular weight (Mn) of 125,000 or more and less than 155000, a weight average molecular weight (Mw) of 265,000 or more and less than 310,000, and Mw / Mn of 1.9 to 2.1. . Cellulose triacetate B has an acetyl group substitution degree of 2.75 to 2.90, Mn of 155,000 or more and less than 180,000, Mw of 290000 or more and less than 360,000, and Mw / Mn of 1.8 to 2.0. A cellulose triacetate.

Cellulose acetate propionate has an acyl group having 2 to 4 carbon atoms as a substituent, and when the substitution degree of acetyl group is X and the substitution degree of propionyl group or butyryl group is Y, the following formula (I ) And (II) are preferably satisfied at the same time.
Formula (I) 2.6 ≦ X + Y ≦ 3.0
Formula (II) 0 ≦ X ≦ 2.5

Among them, it is preferable that 1.9 ≦ X ≦ 2.5 and 0.1 ≦ Y ≦ 0.9.

The method for measuring the substitution degree of the acyl group can be measured according to ASTM-D817-96. The number average molecular weight (Mn) and molecular weight distribution (Mw) of the cellulose ester can be measured using high performance liquid chromatography. The measurement conditions are as follows.
Solvent: Methylene chloride Column: Shodex K806, K805, K803G
(Used by connecting three Showa Denko Co., Ltd.)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (GL Science Co., Ltd.)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0 ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (Tosoh Corporation)
A calibration curve with 13 samples from Mw = 1000000 to 500 was used. The 13 samples are preferably used at approximately equal intervals.

(Thermoplastic acrylic resin)
The film substrate may be configured by using a thermoplastic acrylic resin in combination with a cellulosic resin. When used in combination, the mass ratio of the thermoplastic acrylic resin to the cellulose resin is preferably thermoplastic acrylic resin: cellulose resin = 95: 5 to 50:50.

Acrylic resin also includes methacrylic resin. The acrylic resin is not particularly limited but is preferably composed of 50 to 99% by mass of methyl methacrylate units and 1 to 50% by mass of other monomer units copolymerizable therewith. Examples of other copolymerizable monomers include alkyl methacrylates having 2 to 18 alkyl carbon atoms, alkyl acrylates having 1 to 18 carbon atoms, alkyl acrylates such as acrylic acid and methacrylic acid. Unsaturated group-containing divalent carboxylic acids such as saturated acid, maleic acid, fumaric acid and itaconic acid, aromatic vinyl compounds such as styrene and α-methylstyrene, α, β-unsaturated nitriles such as acrylonitrile and methacrylonitrile, Examples thereof include maleic anhydride, maleimide, N-substituted maleimide, glutaric anhydride, and the like. These may be used alone or in combination of two or more.

Of these, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, s-butyl acrylate, 2-ethylhexyl acrylate, and the like are preferable from the viewpoint of thermal decomposition resistance and fluidity of the copolymer. -Butyl acrylate is particularly preferably used. Further, the weight average molecular weight (Mw) is preferably 80,000 to 500,000, more preferably 110,000 to 500,000.

The weight average molecular weight of the acrylic resin can be measured by gel permeation chromatography. Commercially available acrylic resins include, for example, Delpet 60N, 80N (Asahi Kasei Chemicals Corporation), Dianal BR52, BR80, BR83, BR85, BR88 (Mitsubishi Rayon Co., Ltd.), KT75 (Electrochemical Industry Co., Ltd.) )) And the like. Two or more acrylic resins can be used in combination.

(Λ / 4 film)
A λ / 4 film may be used as the film substrate. By using the λ / 4 film, when the optical film of the present embodiment is incorporated in an image display device, it is preferable from the viewpoint of excellent visibility and crosstalk.

A λ / 4 film refers to a film having an in-plane retardation of the film of about ¼ with respect to a predetermined light wavelength (usually in the visible light region). The λ / 4 film is preferably a broadband λ / 4 film having a phase difference of approximately ¼ of the wavelength in the visible light wavelength range in order to obtain almost perfect circularly polarized light in the visible light wavelength range. .

The λ / 4 film has an in-plane retardation value Ro (550) measured at a wavelength of 550 nm, preferably in the range of 60 nm to 220 nm, more preferably in the range of 80 nm to 200 nm, and more preferably in the range of 90 nm to 190 nm. More preferably, it is the range. The in-plane retardation value Ro is represented by the following formula.
Ro = (nx−ny) × d
However, in the formula, nx and ny are the maximum refractive index in the plane of the film (also referred to as the refractive index in the slow axis direction) out of the refractive index at 23 ° C. and 55% RH and the wavelength of 550 nm, and in the plane of the film. It is the refractive index in the direction perpendicular to the slow axis, and d is the thickness (nm) of the film. Ro can be calculated by measuring the birefringence at each wavelength in an environment of 23 ° C. and 55% RH using an automatic birefringence meter KOBRA-21ADH (manufactured by Oji Scientific Instruments).

Furthermore, in order to function effectively as a λ / 4 film, it is preferable that the relationship of Ro (590) −Ro (450) ≧ 2 nm is satisfied at the same time, and Ro (590) −Ro (450) ≧ 5 nm. More preferably, Ro (590) −Ro (450) ≧ 10 nm is more preferable. Note that Ro (A) indicates an in-plane retardation value measured at a wavelength of Anm.

A circularly polarizing plate is obtained by laminating so that the angle between the slow axis of the λ / 4 film and the transmission axis of the polarizer described later is substantially 45 °. Substantially 45 ° means in the range of 30 ° to 60 °, more preferably in the range of 40 ° to 50 °. The angle between the in-plane slow axis of the λ / 4 film and the transmission axis of the polarizer is preferably 41 to 49 °, more preferably 42 to 48 °, and 43 to 47 °. Is more preferably 44 to 46 °.

The λ / 4 film is not particularly limited as long as it is an optically transparent resin. For example, an acrylic resin, a polycarbonate resin, a cycloolefin resin, a polyester resin, a polylactic acid resin, a polyvinyl alcohol resin, The cellulose-based resin described above can be used. Among these, from the viewpoint of chemical resistance, the λ / 4 film is preferably a cellulose resin or a polycarbonate resin. From the viewpoint of heat resistance, the λ / 4 film is preferably a cellulose resin.

(Retardation adjuster)
The retardation adjustment of λ / 4 can be performed by adding a retardation adjusting agent to the film base described above. As the retardation adjusting agent, an aromatic compound having two or more aromatic rings as described in the specification of European Patent 911,656A2 can be used.

Two or more aromatic compounds may be used in combination. The aromatic ring of the aromatic compound includes an aromatic heterocycle in addition to an aromatic hydrocarbon ring. Particularly preferred is an aromatic heterocycle, and the aromatic heterocycle is generally an unsaturated heterocycle. Of these, a 1,3,5-triazine ring is particularly preferred.

(Fine particles)
In order to improve the handling property, for example, acrylic particles, silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, kaolin, talc, calcined calcium silicate, hydrated calcium silicate, aluminum silicate Further, it is preferable to contain inorganic fine particles such as magnesium silicate and calcium phosphate and a matting agent such as a crosslinked polymer. The acrylic particles are not particularly limited, but are preferably multi-layered acrylic granular composites. Among these, silicon dioxide is preferable in that the haze of the film substrate can be reduced. The primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably in the range of 5 to 16 nm, and particularly preferably in the range of 5 to 12 nm.

(Ester compound)
It is preferable that a film base material contains the ester compound or sugar ester represented by the following general formula (X) from a viewpoint of the dimensional stability by environmental change. First, the ester compound represented by the general formula (X) will be described.

Formula (X) B- (GA) n-GB
Wherein B is a hydroxy group or carboxylic acid residue, G is an alkylene glycol residue having 2 to 12 carbon atoms, an aryl glycol residue having 6 to 12 carbon atoms, or an oxyalkylene glycol residue having 4 to 12 carbon atoms. A represents an alkylene dicarboxylic acid residue having 4 to 12 carbon atoms or an aryl dicarboxylic acid residue having 6 to 12 carbon atoms, and n represents an integer of 1 or more.)

In the general formula (X), the alkylene glycol component having 2 to 12 carbon atoms includes ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,2-propanediol, 2-methyl 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2 , 2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl- 1,5-pentanediol 1,6-hexanediol, 2,2,4-trimethyl 1,3-pentanediol, 2-ethyl 1 There are 3-hexanediol, 2-methyl 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, and the like. Used as a mixture. In particular, alkylene glycols having 2 to 12 carbon atoms are particularly preferable because of excellent compatibility with cellulose acetate. Examples of the aryl glycol component having 6 to 12 carbon atoms include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol and the like, and these glycols can be used as one kind or a mixture of two or more kinds.

Examples of the oxyalkylene glycol component having 4 to 12 carbon atoms include diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, and tripropylene glycol. These glycols may be used alone or in combination of two or more. Can be used as a mixture. Examples of the alkylene dicarboxylic acid component having 4 to 12 carbon atoms include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and the like. Used as a mixture of two or more. Examples of the arylene dicarboxylic acid component having 6 to 12 carbon atoms include phthalic acid, terephthalic acid, isophthalic acid, 1,5 naphthalene dicarboxylic acid, and 1,4 naphthalene dicarboxylic acid. Specific examples of the compound represented by formula (X) (compound X-1 to compound X-17) are shown below, but are not limited thereto.

(Sugar ester compound)
Next, the sugar ester compound will be described. The sugar ester compound is an ester other than cellulose ester, and is a compound obtained by esterifying all or part of the OH group of a sugar such as the following monosaccharide, disaccharide, trisaccharide or oligosaccharide. Examples of the sugar include glucose, galactose, mannose, fructose, xylose, arabinose, lactose, sucrose, nystose, 1F-fructosyl nystose, stachyose, maltitol, lactitol, lactulose, cellobiose, maltose, cellotriose, maltotriose, raffinose And kestose. In addition, gentiobiose, gentiotriose, gentiotetraose, xylotriose, galactosyl sucrose, and the like are also included. Among these compounds, compounds having a furanose structure and / or a pyranose structure are particularly preferable. Among these, sucrose, kestose, nystose, 1F-fructosyl nystose, stachyose and the like are preferable, and sucrose is more preferable. As oligosaccharides, maltooligosaccharides, isomaltooligosaccharides, fructooligosaccharides, galactooligosaccharides, and xylo-oligosaccharides can also be preferably used.

The monocarboxylic acid used for esterifying the sugar is not particularly limited, and known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid and the like can be used. The carboxylic acid to be used may be one kind or a mixture of two or more kinds. Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanecarboxylic acid, undecylic acid, lauric acid , Saturated fatty acids such as tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, and laxelic acid And unsaturated fatty acids such as undecylenic acid, oleic acid, sorbic acid, linoleic acid, linolenic acid, arachidonic acid and octenoic acid. Examples of preferred alicyclic monocarboxylic acids include cyclopentane carboxylic acid, cyclohexane carboxylic acid, cyclooctane carboxylic acid, or derivatives thereof. Examples of preferred aromatic monocarboxylic acids include benzoic acid, aromatic monocarboxylic acids having an alkyl group or alkoxy group introduced into the benzene ring of benzoic acid, cinnamic acid, benzylic acid, biphenylcarboxylic acid, naphthalenecarboxylic acid, tetralin An aromatic monocarboxylic acid having two or more benzene rings such as carboxylic acid, or a derivative thereof can be mentioned, and more specifically, xylic acid, hemelic acid, mesitylene acid, planicylic acid, γ-isojurylic acid, Julylic acid, mesitic acid, α-isoduric acid, cumic acid, α-toluic acid, hydroatropic acid, atropic acid, hydrocinnamic acid, salicylic acid, o-, m, p-anisic acid, creosote acid, o-, m, p-homosalicylic acid, o-pyrocatechuic acid, β-resorcylic acid, vanillic acid, isovanillic acid, veratrum acid o- veratric acid, gallic acid, asarone acid, mandelic acid, homoanisic acid, homovanillic acid, homoveratric acid, o- homoveratric acid, Futaron acid, can be mentioned p- coumaric acid, especially benzoic acid. Among the ester compounds esterified, an acetyl compound into which an acetyl group has been introduced by esterification is preferable. Although the specific example of the sugar ester compound which can be used for this embodiment below is shown, it is not limited to these.

The sugar ester compound is preferably a compound represented by the general formula (Y). Below, the compound shown by general formula (Y) is demonstrated.

(Wherein, R ₁ ~ R ₈ is a hydrogen atom, a substituted or unsubstituted alkylcarbonyl group having 2 to 22 carbon atoms, or a substituted or unsubstituted arylcarbonyl group having 2 to 22 carbon atoms, R ₁ R ₈ may be the same or different.

The compounds represented by formula (Y) are shown below in more detail (compound Y-1 to compound Y-23), but are not limited thereto. In the table below, when the average substitution degree is less than 8.0, any one of R ₁ to R ₈ represents a hydrogen atom.

The substitution degree distribution can be adjusted to the desired substitution degree by adjusting the esterification reaction time or mixing compounds with different substitution degrees.

The ester compound or sugar ester compound represented by the general formula (X) is preferably contained in the cellulose acetate film in an amount of 1 to 30% by mass, more preferably 5 to 25% by mass. It is particularly preferred that

(Plasticizer)
The film substrate may contain a plasticizer as necessary. The plasticizer is not particularly limited, but is a polycarboxylic acid ester plasticizer, glycolate plasticizer, phthalate ester plasticizer, phosphate ester plasticizer, polyhydric alcohol ester plasticizer, acrylic plasticizer. Agents and the like. In these, an acrylic plasticizer is preferable from the point which can control a film base material to the retardation value mentioned later.

The polyhydric alcohol ester plasticizer is a plasticizer composed of an ester of a divalent or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. A divalent to 20-valent aliphatic polyhydric alcohol ester is preferred. Specific examples of the polyhydric alcohol ester plasticizer are shown below, but are not limited thereto.

The glycolate plasticizer is not particularly limited, but alkylphthalylalkyl glycolates can be preferably used. Examples of alkyl phthalyl alkyl glycolates include methyl phthalyl methyl glycolate, ethyl phthalyl ethyl glycolate, propyl phthalyl propyl glycolate, butyl phthalyl butyl glycolate, octyl phthalyl octyl glycolate, methyl phthalyl ethyl Glycolate, ethyl phthalyl methyl glycolate, ethyl phthalyl propyl glycolate, methyl phthalyl butyl glycolate, ethyl phthalyl butyl glycolate, butyl phthalyl methyl glycolate, butyl phthalyl ethyl glycolate, propyl phthalyl butyl glycol Butyl phthalyl propyl glycolate, methyl phthalyl octyl glycolate, ethyl phthalyl octyl glycolate, octyl phthalyl methyl glycolate, octyl phthalate Ethyl glycolate, and the like.

Examples of the phthalate ester plasticizer include diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, and dicyclohexyl terephthalate.

Examples of the phosphate ester plasticizer include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, and the like.

The polycarboxylic acid ester plasticizer is a compound composed of an ester of a divalent or higher, preferably a divalent to 20-valent polyvalent carboxylic acid and an alcohol. Specific examples include triethyl citrate, tributyl citrate, acetyl triethyl citrate (ATEC), acetyl tributyl citrate (ATBC), benzoyl tributyl citrate, acetyl triphenyl citrate, acetyl tribenzyl citrate, dibutyl tartrate, tartaric acid Examples include, but are not limited to, diacetyldibutyl, tributyl trimellitic acid, tetrabutyl pyromellitic acid, and the like.

The acrylic plasticizer is preferably an acrylic polymer, and the acrylic polymer is preferably a homopolymer or copolymer of acrylic acid or alkyl methacrylate. Examples of the acrylate monomer include methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), pentyl acrylate ( n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-), nonyl acrylate (n-, i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-hydroxyethyl), acrylic acid (2-hydroxypropyl), acrylic Acid (3-hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), acrylic acid (2-methoxyethyl), acrylic acid 2-ethoxyethyl), etc., or the acrylic acid ester may include those obtained by changing the methacrylic acid ester. The acrylic polymer is a homopolymer or copolymer of the above monomer, but preferably has 30% by mass or more of acrylic acid methyl ester monomer units, and has 40% by mass or more of methacrylic acid methyl ester monomer units. It is preferable. In particular, a homopolymer of methyl acrylate or methyl methacrylate is preferred.

When the above-mentioned plasticizer is contained in the film base material of this embodiment, it is preferably contained in an amount of 1 to 50% by mass, more preferably 5 to 35% by mass with respect to cellulose acetate. It is particularly preferable to contain 25% by mass.

(UV absorber)
The film base material of this embodiment may contain an ultraviolet absorber. Since the ultraviolet absorber absorbs ultraviolet rays of 400 nm or less, durability can be improved. In particular, the ultraviolet absorber preferably has a transmittance of 10% or less at a wavelength of 370 nm, more preferably 5% or less, and still more preferably 2% or less. Specific examples of the ultraviolet absorber are not particularly limited. For example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex salts, inorganic powders. Examples include the body.

More specifically, for example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6 -(Linear and side chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, and the like can be used. Commercially available products may be used. For example, TINUVIN such as TINUVIN 109, TINUVIN 171, TINUVIN 234, TINUVIN 326, TINUVIN 327, and TINUVIN 328 manufactured by BASF Japan Ltd. can be preferably used.

Preferably used ultraviolet absorbers are benzotriazole ultraviolet absorbers, benzophenone ultraviolet absorbers, and triazine ultraviolet absorbers, and particularly preferably benzotriazole ultraviolet absorbers and benzophenone ultraviolet absorbers. In addition, a discotic compound such as a compound having a 1,3,5 triazine ring is also preferably used as the ultraviolet absorber. As the UV absorber, a polymer UV absorber can be preferably used, and a polymer type UV absorber is particularly preferably used.

As the benzotriazole ultraviolet absorber, TINUVIN 109 (octyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazole-2-) manufactured by BASF Japan Ltd., which is a commercial product, is available. Yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate), TINUVIN 928 (2 -(2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol) and the like can be used. As the triazine-based ultraviolet absorber, commercially available TINUVIN 400 (2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) -manufactured by BASF Japan Ltd.- Reaction product of 5-hydroxyphenyl and oxirane), TINUVIN 460 (2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1,3-5 Triazine), TINUVIN 405 (2- (2,4-dihydroxyphenyl) -4,6-bis- (2,4-dimethylphenyl) -1,3,5-triazine and (2-ethylhexyl) -glycidic acid ester Reaction products) and the like.

The ultraviolet absorber is added by dissolving the ultraviolet absorber in an alcohol, such as methanol, ethanol, butanol or the like, an organic solvent such as methylene chloride, methyl acetate, acetone, dioxolane, or a mixed solvent thereof, and then becomes a film substrate. It may be added to the resin solution (dope) or directly during the dope composition. For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and cellulose acetate to disperse and then added to the dope.

The amount of the ultraviolet absorber used is preferably 0.5 to 10% by mass, more preferably 0.6 to 4% by mass with respect to the cellulose acetate film.

(Antioxidant)
The film substrate of the present embodiment may further contain an antioxidant (deterioration inhibitor). The antioxidant has a role of delaying or preventing the cellulose acetate film from being decomposed by a residual solvent amount of halogen in the cellulose acetate film, phosphoric acid of a phosphoric acid plasticizer, or the like. As the antioxidant, hindered phenol compounds are preferably used. For example, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl) are used. -4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3 5-triazine, 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- 3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1,3 5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate Etc. The amount of these compounds added is preferably 1 ppm to 10000 ppm by weight and more preferably 10 to 1000 ppm with respect to the cellulose acetate film.

(Hindered amine compounds)
When the film substrate is a cellulose ester film, the film substrate may contain a hindered amine compound. The hindered amine compound functions as an antioxidant and has a structure having a bulky organic group (for example, a bulky branched alkyl group) in the vicinity of the N atom. This is a known compound and is described, for example, in columns 5-11 of US Pat. No. 4,619,956 and columns 3-5 of US Pat. No. 4,839,405. As such, 2,2,6,6-tetraalkylpiperidine compounds, or acid addition salts thereof or complexes of them with metal compounds are included. Such compounds include those of the following general formula (H).

In the above formula, R1 and R2 are a hydrogen atom or a substituent.

The substituent represented by R1 is not particularly limited, but a substituent bonded to the piperidine ring by a nitrogen atom or an oxygen atom is preferable, and an amino group, hydroxyl group, alkoxy group, aryloxy group which may have a substituent An acyloxy group is more preferable, and an amino group, a hydroxyl group, an alkoxy group, or an acyloxy group having an alkyl group, an aryl group, or a heterocyclic group as a substituent is more preferable.

The substituent represented by R2 is not particularly limited, but an alkyl group (preferably having 1 to 20, more preferably 1 to 12, particularly preferably 1 to 8 carbon atoms, such as a methyl group, an ethyl group, Isopropyl group, tert-butyl group, n-octyl group, n-decyl group, n-hexadecyl group, cyclopropyl group, cyclopentyl, cyclohexyl group, etc.), alkenyl group (preferably having 2 to 20 carbon atoms, More preferably, it is 2 to 12, particularly preferably 2 to 8, and examples thereof include vinyl group, allyl group, 2-butenyl group, 3-pentenyl group, etc.), alkynyl group (preferably having 2 to 20 carbon atoms) More preferably 2 to 12, particularly preferably 2 to 8, and examples thereof include a propargyl group and a 3-pentynyl group), an aryl group The number of carbon atoms is preferably 6 to 30, more preferably 6 to 20, and particularly preferably 6 to 12, and examples thereof include a phenyl group, a biphenyl group, a naphthyl group, and the like, and an amino group (preferably a carbon atom number of 0). To 20, more preferably 0 to 10, particularly preferably 0 to 6, and examples thereof include an amino group, a methylamino group, a dimethylamino group, a diethylamino group, a dibenzylamino group, and the like, and an alkoxy group (preferably The number of carbon atoms is 1 to 20, more preferably 1 to 12, and particularly preferably 1 to 8, and examples thereof include a methoxy group, an ethoxy group, a butoxy group, and a cyclohexyloxy group.

Specific examples of hindered amines include 4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-allyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-benzyl-4-hydroxy -2,2,6,6-tetramethylpiperidine, 1- (4-tert-butyl-2-butenyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2, 2,6,6-tetramethylpiperidine, 1-ethyl-4-salicyloyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2,2,6,6-pentamethyl Piperidine, 1,2,2,6,6-pentamethylpiperidin-4-yl-β (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, 1-benzyl 2,2,6,6-tetramethyl-4-piperidinyl maleate, (di-2,2,6,6-tetramethylpiperidin-4-yl) -adipate, (di-2,2 , 6,6-tetramethylpiperidin-4-yl) -sebacate, (di-1,2,3,6-tetramethyl-2,6-diethyl-piperidin-4-yl) -sebacate, (di-1- Allyl-2,2,6,6-tetramethyl-piperidin-4-yl) -phthalate, 1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl-acetate, trimellitic acid-tri- ( 2,2,6,6-tetramethylpiperidin-4-yl) ester, 1-acryloyl-4-benzyloxy-2,2,6,6-tetramethylpiperidine, dibutyl-malonic acid-di- (1,2 , 2,6,6-pentamethyl-piperidin-4-yl) -ester, dibenzyl-malonic acid-di- (1,2,3,6-tetramethyl-2,6-diethyl-piperidin-4-yl) -ester Dimethyl-bis- (2,2,6,6-tetramethylpiperidin-4-oxy) -silane, tris- (1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) -phos Fit, tris- (1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) -phosphate, N, N'-bis- (2,2,6,6-tetramethylpiperidine-4- Yl) -hexamethylene-1,6-diamine, tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, tetrakis (1,2,2, 6, -Pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, N, N'-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -hexamethylene-1, 6-diacetamide, 1-acetyl-4- (N-cyclohexylacetamide) -2,2,6,6-tetramethyl-piperidine, 4-benzylamino-2,2,6,6-tetramethylpiperidine, N, N'-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -N, N'-dibutyl-adipamide, N, N'-bis- (2,2,6,6-tetramethyl Piperidin-4-yl) -N, N'-dicyclohexyl- (2-hydroxypropylene), N, N'-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -p-xylylene- Zia 4- (bis-2-hydroxyethyl) -amino-1,2,2,6,6-pentamethylpiperidine, 4-methacrylamide-1,2,2,6,6-pentamethylpiperidine, α- And cyano-β-methyl-β- [N- (2,2,6,6-tetramethylpiperidin-4-yl)]-amino-acrylic acid methyl ester.

Further, N, N ′, N ″, N ′ ″-tetrakis- [4,6-bis- [butyl- (N-methyl-2,2,6,6-tetramethylpiperidin-4-yl) amino]- Triazin-2-yl] -4,7-diazadecane-1,10-diamine, dibutylamine and 1,3,5-triazine N, N'-bis (2,2,6,6-tetramethyl-4- Piperidyl) -1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate (BASF's CHIMASSORB-2020FDL), dibutylamine and 1,3,3 Polycondensate of 5-triazine and N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) butylamine, poly [{(1,1,3,3-tetramethylbutyl) amino -1,3 , 5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino }] (CHIMASSORB 944FDL manufactured by BASF), 1,6-hexanediamine-N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) and morpholine-2,4,6-trichloro Polycondensate with 1,3,5-triazine, poly [(6-morpholino-s-triazine-2,4-diyl) [(2,2,6,6, -tetramethyl-4-piperidyl) imino ] -Hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]] and other high molecular weight HALS (hindered inderamine light) in which a plurality of piperidine rings are bonded via a triazine skeleton. stabilizer); a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2, Mixed esterified product of 6,6-pentamethyl-4-piperidinol and 3,9-bis (2-hydroxy-1,1-dimethylethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane Examples include, but are not limited to, high molecular weight HALS in which a piperidine ring is bonded via an ester bond. Among these, polycondensates of dibutylamine, 1,3,5-triazine and N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl) butylamine, poly [{(1, 1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2 , 2,6,6-tetramethyl-4-piperidyl) imino}], a polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol, etc. A molecular weight (Mn) of 2,000 to 5,000 is preferred.

Examples of preferable hindered amine compounds include the following Specific Example 1 (Sunlizer HA-622, manufactured by Sort Co., Ltd.) and Specific Example 2.

Among the above specific examples, CHIMASSORB 2020FDL (CAS-No. 192268-64-7), CHIMASSORB 944FDL (CAS-No. 71878-19-8), and TINUVIN 770DF manufactured by BASF (former Ciba Specialty Chemicals) (CAS-No. 52829-07-9), Siasorb UV-3346 (CAS-No. 82541-48-7) and Siasorb UV-3529 (CAS-No. 193098-40-7) manufactured by Sun Chemical Co., Ltd. It is suitable because it is commercially available and has excellent availability.

In addition, although the above-mentioned hindered amine compound may be obtained commercially as described above, a synthetically produced compound may be used. There is no restriction | limiting in particular as a synthesis | combining method of a hindered amine type compound, It can synthesize | combine by the method in normal organic synthesis. Moreover, as a production | generation method, the method using distillation, recrystallization, reprecipitation, and a filter agent and adsorption agent can be used suitably. Furthermore, the commercially available products that are available on the market at low cost may be a mixture instead of the hindered amine compound alone, but in the present embodiment, the commercially available product is obtained by the production method, composition, melting point, acid value. It can be used regardless of the above.

The hindered amine compound used for the film substrate may be a low molecular weight polymer or a polymer having a repeating unit, but a hindered amine compound is provided in the vicinity of the interface between the active energy ray cured layer and the film substrate. A high molecular weight is preferable for uneven distribution. On the other hand, if the molecular weight is too high, the compatibility with the film substrate (for example, cellulose acylate) is insufficient, and the haze of the film is increased.

The molecular weight of the hindered amine compound is preferably 300 to 100,000, more preferably 700 to 50,000, and particularly preferably 2,000 to 30,000.

The content of the hindered amine compound with respect to the film substrate is preferably 0.001% by mass to 5% by mass, more preferably 0.001% by mass to 2% by mass, and 0.01% by mass. The content is more preferably 1.5% by mass or less, and particularly preferably 0.05% by mass or more and 1.0% by mass or less.

When the content of the hindered amine compound is less than 0.001% by mass with respect to the film substrate, sufficient adhesion between the cured layer and the film substrate cannot be ensured. When the content of the hindered amine compound is 5% by mass or less, the hindered amine compound is less likely to bleed out, which is preferable from the viewpoint of improving the polarization performance of the polarizing plate.

(Polymer containing repeating units derived from the monomer represented by formula (P))
When a film base material is a cellulose-ester film, it is preferable from the effect of this embodiment that a film base material contains the polymer containing the repeating unit derived from the monomer represented by the following general formula (P).

In general formula (P), R ¹ represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ¹ is not particularly limited, but is preferably a hydrogen atom, a methyl group, or an ethyl group.

R ² represents a substituent, and the substituent is preferably an aliphatic group or an aromatic group. R ² is not particularly limited, but the aliphatic group is preferably an alkyl group, an alkenyl group, an alkynyl group or a cycloalkyl group, more preferably an alkyl group having 1 to 6 carbon atoms, a methyl group, an ethyl group or a propyl group. A butyl group is more preferable, and a methyl group and a t-butyl group are particularly preferable. As the aromatic group, a phenyl group, a naphthyl group, and a biphenyl group are preferable, and a phenyl group is particularly preferable.

n represents an integer of 0 to 4, preferably 0 to 2, and more preferably 0 to 1. Note that when n is 0, the substituent R ² does not exist, but in the chemical formula, this means that a hydrogen atom is sufficient.

(A) represents an atomic group necessary for forming a 5- or 6-membered ring, and is preferably a 5- or 6-membered aromatic ring. The aromatic ring in this specification is a concept including an aromatic ring containing no hetero atom and a saturated / unsaturated hetero ring containing a hetero atom.

In view of the effect of suppressing the moisture permeability and moisture content of the film, the mass average molecular weight of the polymer represented by the general formula (P) is preferably 200 to 10,000, and more preferably 300 to 8,000. 400 to 4,000 is particularly preferable. From the effect of suppressing the moisture permeability and moisture content of the film, an improvement in compatibility with the cellulose acylate can be expected when it is not more than the upper limit.

Unless otherwise specified, the molecular weight and dispersity are values measured using a GPC (gel filtration chromatography) method, and the molecular weight can be measured by a polystyrene-reduced mass average molecular weight.

The addition amount of the polymer represented by the general formula (P) is not particularly limited, but is preferably 0.1 to 100 parts by mass with respect to 100 parts by mass of the resin forming the film substrate, and 0.5 to The amount is more preferably 50 parts by mass, and particularly preferably 1.0 to 30 parts by mass.

Hereinafter, although the specific example of the polymer which has a repeating unit derived from the monomer represented by general formula (P) is shown, this invention is limited to this and is not interpreted. In addition, the following structural formula has shown the chemical structure of the repeating unit of the main component, and its structural ratio, and it is as above-mentioned that the other component may be contained.

The polymer of the present specification includes not only a polymer that is a general polymer compound in which a large number of monomers are polymerized, but also an oligomer that is a compound having a molecular weight of about several hundreds, in which several monomers are polymerized, for example. means. Unless otherwise specified, polymers, copolymers or copolymers are also included.

(Organic acid)
When a film base material is a cellulose-ester film, it is preferable from the effect of this embodiment that a film base material contains an organic acid. The molecular weight of the organic acid is preferably 200 to 1000, more preferably 250 to 800, and particularly preferably 280 to 500. The organic acid preferably includes an aromatic ring structure, preferably includes an aryl group having 6 to 12 carbon atoms, and particularly preferably includes a phenyl group. The aromatic ring structure of the organic acid may form a condensed ring with other rings. The aromatic ring structure of the organic acid may have a substituent, but is preferably a halogen atom or an alkyl group, more preferably a halogen atom or an alkyl group having 1 to 6 carbon atoms, and a chlorine atom. Or it is especially preferable that it is a methyl group. The organic acid is preferably represented by the following general formula (Q) from the effect of this embodiment.

In the general formula (Q), R ²⁶ represents an aryl group, and R ²⁷ and R ²⁸ each independently represent a hydrogen atom, an alkyl group, or an aryl group. R ²⁶ and R ²⁷ may each have a substituent. R ²⁶ is preferably an aryl group having 6 to 18 carbon atoms, more preferably an aryl group having 6 to 12 carbon atoms, and particularly preferably a phenyl group. R ²⁷ and R ²⁸ are preferably each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms (including a cycloalkyl group) or an aryl group having 6 to 12 carbon atoms. It is more preferably an alkyl group of 6 (including a cycloalkyl group) or a phenyl group, and particularly preferably a hydrogen atom, a methyl group, an ethyl group, a cyclohexane group or a phenyl group. Specific examples of the organic acid represented by the general formula (Q) are illustrated below, but the present invention is not limited to the following.

The content of the organic acid is preferably 1 to 20% by mass with respect to the cellulose ester.

(Compound represented by formula (S))
When a film base material is a cellulose-ester film, it is preferable from the effect of this embodiment that a film base material contains the compound represented by the following general formula (S).

In the general formula (S), R ¹ represents a hydrogen atom or a substituent, and R ² represents a substituent represented by the following general formula (a). n1 represents an integer of 0 to 4. When n1 is 2 or more, the plurality of R ¹ may be the same as or different from each other. n2 represents an integer of 1 to 5. When n2 is 2 or more, the plurality of R ² may be the same as or different from each other.

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

In general formula (b), X represents a substituted or unsubstituted aromatic ring. R ⁶ , R ⁷ , R ⁸ and R ⁹ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. n5 represents an integer of 1 to 11. When n5 is 2 or more, the plurality of R ⁶ , R ⁷ , R ⁸ and X may be the same as or different from each other.

Hereinafter, specific examples of the compound represented by the general formula (S) are shown, but the compound is not limited thereto.

The weight average molecular weight of the compound represented by the general formula (S) is preferably from 200 to 1,200, more preferably from 250 to 1,000, and particularly preferably from 300 to 800.

The addition amount of the compound represented by the general formula (S) is not particularly limited, but is preferably from 0.1 to 100 parts by mass with respect to 100 parts by mass of the film base material, and is preferably from 0.2 to 80 The amount is more preferably part by mass, and particularly preferably 0.3 to 60 parts by mass.

(Disadvantage)
The film substrate preferably has a defect of 5 μm or more in diameter of 1 piece / 10 cm square or less. More preferably, it is 0.5 piece / 10 cm square or less, more preferably 0.1 piece / 10 cm square or less. Here, the diameter of the defect indicates the diameter when the defect is circular, and when the defect is not circular, the range of the defect is determined by observing with a microscope by the following method, and the maximum diameter (diameter of circumscribed circle) is determined.

The range of the defect is the size of the shadow when the defect is observed with the transmitted light of the differential interference microscope when the defect is a bubble or a foreign object. When the defect is a change in the surface shape such as transfer of a roller scratch or an abrasion, the size can be confirmed by observing the defect with the reflected light of a differential interference microscope.

When the number of defects is more than 1/10 cm square, for example, when a tension is applied to the film during processing in a later process, the film may be broken with the defect as a starting point and productivity may be reduced. Moreover, when the diameter of a defect becomes 5 micrometers or more, it can confirm visually by polarizing plate observation etc., and when used as an optical member, a bright spot may arise.

Moreover, even when it cannot be visually confirmed, when the cured layer is formed, the coating film may not be formed uniformly, resulting in a defect (missing coating). Here, the defect is a void in the film (foaming defect) generated due to the rapid evaporation of the solvent in the drying process of the solution casting, a foreign matter in the film forming stock solution, or a foreign matter mixed in the film forming. This refers to the foreign matter (foreign matter defect) in the film. Further, the film base material preferably has a breaking elongation of at least one direction of 10% or more, more preferably 20% or more in the measurement based on JIS-K7127-1999. The upper limit of the elongation at break is not particularly limited, but is practically about 250%. In order to increase the elongation at break, it is effective to suppress defects in the film caused by foreign matter and foaming.

(optical properties)
The film substrate preferably has a total light transmittance of 90% or more, more preferably 92% or more. Moreover, as a realistic upper limit, it is about 99%. The haze value is preferably 2% or less, more preferably 1.5% or less. The total light transmittance and haze value can be measured according to JIS K7361 and JIS K7136.

The in-plane retardation value Ro of the film base is preferably 0 to 5 nm, and the retardation value Rth in the thickness direction is preferably in the range of −10 to 10 nm. Further, Rth is preferably in the range of -5 to 5 nm. Alternatively, the retardation Ro is preferably in the range of 30 to 200 nm, and more preferably in the range of 30 to 90 nm. The retardation Rth in the thickness direction is preferably in the range of 70 to 300 nm.

The in-plane retardation Ro value is defined by the following formula (I), and the retardation value Rth in the thickness direction is defined by the following formula (II).
Formula (I) Ro = (nx−ny) × d
Formula (II) Rth = {(nx + ny) / 2−nz} × d
(Where nx is the refractive index in the slow axis direction in the plane of the film base, ny is the refractive index in the direction perpendicular to the slow axis in the plane of the film base, and nz is the thickness direction of the film base) (Refractive index, d represents the thickness (nm) of the film substrate, respectively)

The retardation can be obtained at a wavelength of 590 nm under an environment of 23 ° C. and 55% RH (relative humidity) using, for example, KOBRA-21ADH (manufactured by Oji Scientific Instruments).

[Film formation]
Next, as a film forming method of the film substrate, a cellulose ester film will be described as an example, but the film forming method is not limited thereto. As a method for producing a cellulose ester film, a production method such as an inflation method, a T-die method, a calendar method, a cutting method, a casting method, an emulsion method, a hot press method, or the like can be used.

(Organic solvent)
An organic solvent useful for forming a resin solution (dope composition) in the case of producing a cellulose ester film by a solution casting film forming method described later is one that can simultaneously dissolve a cellulose ester resin and other additives. Can be used without limitation. For example, as a chlorinated organic solvent, methylene chloride, as a non-chlorinated organic solvent, methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-hexafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro- 2-methyl-2-propanol, 1,1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane, methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, tert-butanol, etc. Can, methylene chloride, methyl acetate, ethyl acetate, may be used preferably acetone. The solvent is preferably a dope composition in which a total of 15 to 45 mass% of cellulose ester resin and other additives are dissolved.

(Solution casting film forming method)
In the solution casting film forming method, a step of preparing a dope by dissolving a resin and an additive in a solvent, a step of casting the dope on a belt-shaped or drum-shaped metal support, and drying the cast dope as a web It is carried out by a step of peeling off from the metal support, a step of stretching or maintaining the width, a step of further drying, and a step of winding up the finished cellulose ester film.

As the metal support, a stainless steel belt or a drum whose surface is plated with a casting is preferably used.

The width of the cast (casting) can be 1 to 4 m. The surface temperature of the metal support in the casting process is set to −50 ° C. to a temperature at which the solvent boils and does not foam. A higher temperature is preferred because the web can be dried faster, but if it is too high, the web may foam or the flatness may deteriorate.

A preferable support temperature is appropriately determined at 0 to 100 ° C., and more preferably 5 to 30 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent. The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing warm air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short.

When using warm air, considering the temperature drop of the web due to the latent heat of vaporization of the solvent, while using warm air above the boiling point of the solvent, there may be cases where wind at a temperature higher than the target temperature is used while preventing foaming. .

In particular, it is preferable to efficiently dry by changing the temperature of the support and the temperature of the drying air during the period from casting to peeling.

In order for the cellulose ester film to obtain good flatness, the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 60%. It is 130% by mass, particularly preferably 20 to 30% by mass or 70 to 120% by mass. The amount of residual solvent is defined by the following formula.
Residual solvent amount (% by mass) = {(MN) / N} × 100
In addition, M is the mass of the sample collected at any time during or after the production of the web or film, and N is the mass after heating at 115 ° C. for 1 hour.

In the drying step of the cellulose ester film, the web is peeled off from the metal support and dried to make the residual solvent amount 1% by mass or less, more preferably 0.1% by mass or less, and particularly preferably 0. -0.01 mass% or less.

In the film drying process, generally, a roller drying method (a method in which webs are alternately passed through a plurality of rollers arranged above and below) and a method in which the web is dried while being conveyed by a tenter method are employed.

In the stretching step, the film can be sequentially or simultaneously stretched in the longitudinal direction (MD direction) and the lateral direction (TD direction). The draw ratios in the biaxial directions perpendicular to each other are preferably in the range of 1.0 to 2.0 times in the MD direction and 1.05 to 2.0 times in the TD direction, respectively. More preferably, it is carried out in the range of 1.0 to 1.5 times and 1.05 to 2.0 times in the TD direction. For example, a method of making a difference in peripheral speed between a plurality of rollers and stretching in the MD direction using the difference in peripheral speed of the roller between them, fixing both ends of the web with clips and pins, and widening the interval between the clips and pins in the traveling direction And a method of stretching in the MD direction, a method of stretching in the lateral direction and stretching in the TD direction, a method of stretching the MD direction and the TD direction simultaneously, and stretching in both directions.

It is preferable to perform the width maintenance or the stretching in the width direction in the film forming process by a tenter, and it may be a pin tenter or a clip tenter.

The film transport tension in the film forming process such as a tenter is preferably 120 to 200 N / m, more preferably 140 to 200 N / m, and most preferably 140 to 160 N / m, although it depends on the temperature.

The stretching temperature is (Tg-30) to (Tg + 100) ° C., more preferably (Tg-20) to (Tg + 80) ° C., more preferably (Tg-5), where Tg is the glass transition temperature of the cellulose ester film. ~ (Tg + 20) ° C.

The Tg of the cellulose ester film can be controlled by the material type constituting the film and the ratio of the constituting materials. The Tg when the cellulose ester film is dried is preferably 110 ° C. or higher, more preferably 120 ° C. or higher. Especially preferably, it is 150 degreeC or more. The glass transition temperature is preferably 190 ° C. or lower, more preferably 170 ° C. or lower. The Tg of the cellulose ester film can be determined by the method described in JIS K7121. The stretching temperature is preferably 150 ° C. or more and the stretching ratio is 1.15 times or more because the surface is appropriately roughened. Roughening the surface of the cellulose ester film is preferable because it improves slipperiness and improves surface processability.

(Melt casting method)
The film substrate may be formed by a melt casting film forming method. In the melt casting film forming method, a composition containing other additives such as a cellulose ester resin and a plasticizer is heated and melted to a temperature showing fluidity, and then a melt containing the fluid cellulose ester is cast. To do.

In the melt casting film forming method, the melt extrusion method is preferable from the viewpoint of mechanical strength and surface accuracy. It is preferable that a plurality of raw materials used for melt extrusion are usually kneaded in advance and pelletized.

Pelletization may be performed by a known method, for example, dry cellulose ester, plasticizer, and other additives are fed to an extruder with a feeder, kneaded using a single or twin screw extruder, and formed into a strand from a die. Can be extruded, water-cooled or air-cooled, and then cut.

Additives may be mixed before being supplied to the extruder, or may be supplied by individual feeders.

A small amount of additives such as particles and antioxidants are preferably mixed in advance in order to mix uniformly.

The extruder is preferably processed at a temperature as low as possible so that it can be pelletized so that the shearing force is suppressed and the resin does not deteriorate (molecular weight reduction, coloring, gel formation, etc.). For example, in the case of a twin screw extruder, it is preferable to rotate in the same direction using a deep groove type screw. From the uniformity of kneading, the meshing type is preferable.

Film formation is performed using the pellets obtained as described above. Of course, the raw material powder can be directly fed to the extruder by a feeder without being pelletized to form a film as it is.

Using a single-screw or twin-screw extruder, the pellets are melted at a temperature of about 200 to 300 ° C, filtered through a leaf disk filter, etc. to remove foreign matter, and then formed into a film from the T die. The cellulose ester film is formed by niping the film with a cooling roller and an elastic touch roller and solidifying the film on the cooling roller.

When introducing from the supply hopper to the extruder, it is preferable to prevent oxidative decomposition and the like under vacuum, reduced pressure, or inert gas atmosphere.

The extrusion flow rate is preferably adjusted stably by introducing a gear pump or the like. Further, a stainless fiber sintered filter is preferably used as a filter used for removing foreign substances. The stainless steel fiber sintered filter is a united stainless steel fiber body that is intricately intertwined and compressed, and the contact points are sintered and integrated. The density of the fiber is changed depending on the thickness of the fiber and the amount of compression, and the filtration accuracy is improved. Can be adjusted.

Additives such as plasticizers and particles may be mixed with the resin in advance, or may be kneaded in the middle of the extruder. In order to add uniformly, it is preferable to use a mixing apparatus such as a static mixer.

The cellulose ester film temperature on the touch roller side when the cellulose ester film is nipped by the cooling roller and the elastic touch roller is preferably Tg or more (Tg + 110 ° C.) or less of the film. A known roller can be used as the roller having an elastic surface used for such a purpose.

The elastic touch roller is also called a pinching rotator. A commercially available elastic touch roller can also be used.

When peeling the cellulose ester film from the cooling roller, it is preferable to control the tension to prevent deformation of the film.

Moreover, it is preferable that the cellulose ester film obtained as described above is stretched by the stretching operation after passing through the step of contacting the cooling roller.

As the stretching method, a known roller stretching machine or tenter can be preferably used. The stretching temperature is usually preferably in the temperature range of Tg to (Tg + 60) ° C. of the resin constituting the film.

Before winding, the end may be slit and trimmed to the width of the product, and knurled (embossed) may be applied to both ends to prevent sticking and scratching during winding. The knurling method can be performed by heating or pressurizing using a metal ring having an uneven pattern on the side surface. The grip portion of the clip at both ends of the film is usually cut out and reused because the cellulose ester film is deformed and cannot be used as a product.

(Manufacturing method of obliquely stretched film)
The λ / 4 film can be produced by a method for producing an obliquely stretched film. The method for producing an obliquely stretched film is a method for producing a stretched film having a slow axis at an angle of more than 0 ° and less than 90 ° with respect to the extending direction of the film. As the unstretched film before oblique stretching, the cellulose ester film described above can be used.

Here, the angle with respect to the extending direction of the film is an angle in the film plane. Since the slow axis is usually expressed in the stretching direction or a direction perpendicular to the stretching direction, stretching having such a slow axis is performed by stretching at an angle of more than 0 ° and less than 90 ° with respect to the extending direction of the film. A film can be manufactured.

The angle between the film extension direction and the slow axis (orientation angle θ) can be arbitrarily set to a desired angle in the range of more than 0 ° and less than 90 °, more preferably 10 ° to 80 °. °, more preferably 40 ° to 50 °.

(Diagonal stretching)
The obliquely stretched film can be produced using an obliquely stretching apparatus (obliquely stretched tenter). As an obliquely stretched tenter, the orientation angle of the film can be set freely by changing the rail pattern in various ways, and furthermore, the orientation axis of the film can be oriented with high precision evenly on the left and right across the width direction of the film. An apparatus capable of controlling the film thickness and retardation with high accuracy can be preferably used.

(Physical properties of film substrate)
The thickness of the film substrate is preferably 5 to 200 μm, more preferably 5 to 80 μm, and particularly preferably 5 to 34 μm. By forming the hardened layer of the present embodiment on a thin film substrate, the effect of the present embodiment is more easily exhibited. The length of the film substrate is preferably 500 to 10000 m, more preferably 1000 to 8000 m. By setting it as the range of the said length, it is excellent in the processability in application | coating, such as a hardened layer, and the handleability of film base itself.

The arithmetic average roughness Ra of the film substrate is preferably 2 to 10 nm, more preferably 2 to 5 nm. The arithmetic average roughness Ra can be measured according to JIS B0601: 1994.

[Other layers]
The optical film of this embodiment can be provided with other layers such as an antireflection layer and a conductive layer.

(Antireflection layer)
The optical film of this embodiment can be used as an antireflection film having an external light antireflection function by coating an antireflection layer on a cured layer.

The antireflection layer is preferably laminated in consideration of the refractive index, the film thickness, the number of layers, the layer order, and the like so that the reflectance is reduced by optical interference. The antireflection layer is composed of a low refractive index layer having a lower refractive index than the protective film as the support, or a combination of a high refractive index layer and a low refractive index layer having a higher refractive index than the protective film as the support. Preferably it is.

<Low refractive index layer>
The low refractive index layer preferably contains silica-based fine particles, and the refractive index is preferably in the range of 1.30 to 1.45 when measured at 23 ° C. and wavelength of 550 nm.

The film thickness of the low refractive index layer is preferably in the range of 5 nm to 0.5 μm, more preferably in the range of 10 nm to 0.3 μm, and in the range of 30 nm to 0.2 μm. Most preferred.

The composition for forming a low refractive index layer preferably contains at least one kind of particles having an outer shell layer and porous or hollow inside as silica-based fine particles. In particular, the particles having the outer shell layer and porous or hollow inside are preferably hollow silica-based fine particles.

The composition for forming a low refractive index layer may contain an organosilicon compound represented by the following general formula (OSi-1) or a hydrolyzate thereof, or a polycondensate thereof.
Formula (OSi-1): Si (OR) ₄
In the formula, R represents an alkyl group having 1 to 4 carbon atoms. Specifically, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane and the like are preferably used as the organosilicon compound represented by the general formula.

In addition, a compound having a thermosetting property and / or a photocurable property, which mainly contains a fluorine-containing compound containing a fluorine atom in a range of 35 to 80% by mass and containing a crosslinkable or polymerizable functional group, has a low refractive index. You may make it contain in the composition for layer formation. Specifically, a fluorine-containing polymer or a fluorine-containing sol-gel compound is used. Examples of the fluorine-containing polymer include hydrolysates and dehydration condensates of perfluoroalkyl group-containing silane compounds [eg (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane], and fluorine-containing monomers. Examples thereof include fluorine-containing copolymers having units and cross-linking reactive units as constituent units. In addition, you may add a solvent, a silane coupling agent, a hardening | curing agent, surfactant, etc. to the composition for low refractive index layer formation as needed.

<High refractive index layer>
In the high refractive index layer, it is preferable to adjust the refractive index to a range of 1.4 to 2.2 by measuring at 23 ° C. and a wavelength of 550 nm. The thickness of the high refractive index layer is preferably 5 nm to 1 μm, more preferably 10 nm to 0.2 μm, and most preferably 30 nm to 0.1 μm. Adjustment of the refractive index can be achieved by adding metal oxide fine particles and the like. The metal oxide fine particles used preferably have a refractive index of 1.80 to 2.60, more preferably 1.85 to 2.50.

The kind of metal oxide fine particles is not particularly limited, and Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P and S A metal oxide having at least one element selected from can be used.

<Conductive layer>
In the optical film, a conductive layer may be formed on the cured layer. As the conductive layer provided, a generally well-known conductive material can be used. For example, metal oxides such as indium oxide, tin oxide, indium tin oxide, gold, silver, and palladium can be used. These can be formed as a thin film on an optical film by a vacuum deposition method, a sputtering method, an ion plating method, a solution coating method, or the like. Moreover, it is also possible to form a conductive layer using the organic conductive material which is the above-described π-conjugated conductive polymer.

In particular, a conductive material that is excellent in transparency and conductivity, and that has a main component of any one of indium oxide, tin oxide, and indium tin oxide obtained at a relatively low cost can be suitably used. Although the thickness of the conductive layer varies depending on the material to be applied, it cannot be said unconditionally. However, the surface resistivity is 1000Ω or less, preferably 500Ω or less, and considering the economy, A range of 10 nm or more, preferably 20 nm or more and 80 nm or less, preferably 70 nm or less is suitable. In such a thin film, visible light interference fringes due to uneven thickness of the conductive layer are unlikely to occur.

〔Polarizer〕
Next, a polarizing plate using the optical film of this embodiment will be described. The polarizing plate can be produced by a general method. For example, an optical film is subjected to alkali saponification treatment, and the treated optical film is bonded to one surface of a polarizing film (polarizer) produced by immersing and stretching in an iodine solution using a completely saponified polyvinyl alcohol aqueous solution. Is preferred.

The optical film may be bonded to the other surface of the polarizer, or the above-described film substrate may be bonded. The film thickness of the film substrate to be bonded to the other surface is preferably in the range of 5 to 100 μm, more preferably in the range of 5 to 34 μm, from the viewpoint of adjusting smoothness and curl balance and further improving the effect of preventing winding deviation.

The polarizing film, which is the main component of the polarizing plate, is an element that transmits only light having a polarization plane in a certain direction, and a typical polarizing film that is known at present is a polyvinyl alcohol polarizing film. The polarizing film includes a polyvinyl alcohol film dyed with iodine and a dichroic dye dyed, but is not limited thereto.

For the polarizing film, a polyvinyl alcohol aqueous solution is formed and dyed by uniaxial stretching or dyeing, or after uniaxial stretching after dyeing, a film subjected to durability treatment with a boron compound is preferably used. The thickness of the polarizing film is 5 to 30 μm, preferably 8 to 15 μm.

A polarizing plate is formed by bonding one side of the optical film of the present embodiment on the surface of the polarizing film. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.

(Circularly polarizing plate)
A circularly polarizing plate can also be constituted using an optical film. That is, a circularly polarizing plate can be formed by laminating a polarizing plate protective film, a polarizer, and a λ / 4 film in this order. In this case, the angle formed between the slow axis of the λ / 4 film and the absorption axis (or transmission axis) of the polarizing film is 45 °. A long polarizing plate protective film, a long polarizer, and a long λ / 4 film (long diagonally stretched film) are preferably laminated in this order.

The circularly polarizing plate can be produced by using a stretched polyvinyl alcohol doped with iodine or a dichroic dye as a polarizer, and laminating with a configuration of λ / 4 film / polarizer. The thickness of the polarizer is 5 to 40 μm, preferably 5 to 30 μm, particularly preferably 5 to 20 μm.

The circularly polarizing plate can be produced by a general method. In other words, it is preferable to attach an alkali saponified λ / 4 film to one surface of a polarizer produced by immersing and stretching a polyvinyl alcohol film in an iodine solution, using a completely saponified polyvinyl alcohol aqueous solution.

(Adhesive layer)
In order to bond the substrate of the liquid crystal cell and the polarizing plate, the pressure-sensitive adhesive layer used on one side of the film of the polarizing plate is preferably optically transparent and exhibits moderate viscoelasticity and pressure-sensitive adhesive properties.

Specific examples of the adhesive layer include adhesives or adhesives such as acrylic copolymers, epoxy resins, polyurethane, silicone polymers, polyethers, butyral resins, polyamide resins, polyvinyl alcohol resins, and synthetic rubbers. A film such as a drying method, a chemical curing method, a thermal curing method, a thermal melting method, a photocuring method, or the like can be formed and cured using a polymer such as the above. Among them, the acrylic copolymer can be preferably used because it is most easy to control the physical properties of the adhesive and is excellent in transparency, weather resistance, durability and the like.

(Image display device)
The optical film of this embodiment is preferable in that the performance excellent in visibility is exhibited by using it for an image display apparatus. As an image display device, a reflection type, a transmission type, a transflective type liquid crystal display device, a liquid crystal display device of various driving methods such as a TN type, an STN type, an OCB type, a VA type, an IPS type, and an ECB type, an organic EL display Examples thereof include a device and a plasma display. Among these image display devices, a liquid crystal display device is preferable because of its high visibility.

Protective part may be arranged on the further viewing side of the cured layer of the optical film of the viewing side polarizing plate. This protection part can be constituted by a front plate or a touch panel. The said protection part is bonded together by the said hardened layer via the filler (photocurable resin) for filling the space | gap between hardened layers. The front plate in particular of a protection part is not restrict | limited, A conventionally well-known thing, such as an acrylic board and a glass plate, can be used. Further, the material, thickness, and the like of the front plate can be appropriately selected according to the use of the image display device.

As the filler, a solvent-free filler is preferable, and as commercially available products, for example, SVR1120, SVR1150, SVR1320 (above, manufactured by Dexerials Corporation), or HRJ-60, HRJ-302, HRJ-53 (above, Kyoritsu Chemical Industry) And the like). When using a filler, one type may be used independently and multiple types may be used together.

Bonding of the optical film and the front plate can be performed as follows, for example. First, a filler is prepared. Then, a filler is applied to the surface of the cured layer of the optical film, and the front plate is overlaid on the coating film of the filler. In this state, the filler is cured by light irradiation or the like, and the optical film and the front plate are bonded together. When the filler is applied to the surface of the cured layer, the surface free energy of the cured layer is set to 30 mN / m or more so that the filler is uniformly spread without being repelled at the end of the cured layer. An image display device that is maintained and has excellent visibility can be obtained.

〔Example〕
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

<Example 1>
[Production of Cellulose Ester Film 1]
<Preparation of silicon dioxide dispersion>
Aerosil R812 (Nippon Aerosil Co., Ltd., average primary particle diameter of 7 nm)
10 parts by mass Ethanol 90 parts by mass The above was stirred and mixed with a dissolver for 30 minutes, and then dispersed with Manton Gorin. 88 parts by mass of methylene chloride was added to the silicon dioxide dispersion while stirring, and the mixture was stirred and mixed for 30 minutes with a dissolver to prepare a silicon dioxide dispersion dilution. The mixture was filtered with a fine particle dispersion dilution filter (Advantech Toyo Co., Ltd .: polypropylene wind cartridge filter TCW-PPS-1N).

<Preparation of Dope Composition 1>
(Cellulose ester resin)
Cellulose triacetate A (cellulose triacetate synthesized from linter cotton, acetyl group substitution degree 2.88, Mn = 14,000)
90 parts by mass (additive)
Ester Represented by General Formula (X) (Exemplary Compound X-1) 5 parts by mass Ester Represented by General Formula (X) (Exemplary Compound X-12) 4 parts by mass (UV absorber)
TINUVIN 928 (manufactured by BASF Japan Ltd.) 3 parts by mass (fine particles)
Silicon dioxide dispersion dilution 4 parts by mass (solvent)
Methylene chloride 432 parts by mass Ethanol 38 parts by mass The above was put into a sealed container, heated and stirred, and dissolved completely. Azumi filter paper No. Azumi filter paper No. 24 was used to prepare a dope (dope composition 1).

Next, the belt was cast evenly on a stainless steel band support using a belt casting apparatus. With the stainless steel band support, the solvent was evaporated until the residual solvent amount reached 100% by mass, and the stainless steel band support was peeled off. The cellulose ester film web was evaporated at 35 ° C., slit to 1.15 m width, and dried at a drying temperature of 140 ° C. while being stretched 1.15 times in the TD direction (film width direction) with a tenter. I let you. Then, it was dried for 15 minutes while being transported in a drying device at 120 ° C. with a number of rollers, slitted to a width of 1.3 m, knurled with a width of 10 mm and a height of 5 μm at both ends of the film, and wound around a core. The cellulose ester film 1 was obtained. The cellulose ester film 1 had a film thickness of 15 μm and a winding length of 3900 m.

In addition, the draw ratio in the MD direction calculated from the rotational speed of the stainless steel band support and the operating speed of the tenter was 1.01.

[Preparation of optical film 1]
The following cured layer composition 1 is applied onto the A side (the surface not in contact with the casting belt) of the produced cellulose ester film 1 using an extrusion coater, and the constant rate drying zone temperature is 50 ° C., the rate of decrease. After drying at a drying section temperature of 50 ° C., while purging with nitrogen so that the atmosphere has an oxygen concentration of 1.0% by volume or less, the irradiance of the irradiated part is 100 mW / cm ² using an ultraviolet lamp, and the irradiation amount is set to 0. The coating layer was cured at 25 J / cm ² to form a cured layer 1 having a dry film thickness of 5 μm, and wound into a roll to produce an optical film 1.

<< Hardened layer composition 1 >>
<Composition of cured layer composition 1>
(Resin (A))
M-8 (urethane acrylate: UA-1100, manufactured by Shin-Nakamura Chemical Co., Ltd.)
90 parts by mass (photopolymerization initiator)
Irgacure 184 (manufactured by BASF Japan) 5 parts by mass (additive)
Silicone compound (BYK-UV3510, manufactured by BYK Japan)
1 part by mass (compound (B))
F-1 (biphenyl-2-carboxylic acid, molecular weight 198, manufactured by Tokyo Chemical Industry Co., Ltd.)
10 parts by mass (solvent)
Propylene glycol monomethyl ether 10 parts by weight Methyl acetate 30 parts by weight Methyl ethyl ketone 70 parts by weight

[Preparation of optical films 2 to 15]
Except that the resin (A) and the compound (B) of the cured layer composition 1 of the optical film 1 were changed to the resin (A) and the compound (B) described in Table 1, respectively, in the same manner as the production of the optical film 1. Thus, optical films 2 to 15 were produced.

In Table 1, resin M-1 is 1,6-hexanediol diacrylate (A-HD-N, manufactured by Shin-Nakamura Kogyo Co., Ltd.), and resin M-2 is 1,10-decanediol diacrylate. (A-DOD, manufactured by Shin-Nakamura Kogyo Co., Ltd.). Resin M′-1 is trimethylolpropane triacrylate (TMPTA, manufactured by Tokyo Chemical Industry Co., Ltd.), and resin M′-2 is tricyclodecane dimethanol diacrylate (A-DCP, Shin-Nakamura Industrial Co., Ltd.). Made). For reference, the structural formulas of Resin M′-1 and Resin M′-2 are shown below.

In Table 1, compound F-2 is 2,2-biphenyldicarboxylic acid (molecular weight 242; manufactured by Tokyo Chemical Industry Co., Ltd.), and compound F-3 is benzoic acid (molecular weight 122, manufactured by Tokyo Chemical Industry Co., Ltd.). Compound F-4 is 1,3,5-tris (4′-carboxy [1,1′-biphenyl] -4-yl) benzene (molecular weight 667, manufactured by Aldrich), and compound G-3 Is 1-benzyl-5-phenylbarbituric acid (molecular weight 294, manufactured by Tokyo Chemical Industry Co., Ltd.). Compound F′-1 is benzenesulfonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), compound F′-2 is Tinuvin P (manufactured by Ciba Japan), and compound F′-3 is decanoic acid. (Manufactured by Tokyo Chemical Industry Co., Ltd.). For reference, structural formulas of compounds F′-1, F′-2, and F′-3 are shown below.

[Preparation of optical films 16 and 17]
In the cured layer composition 1 of the optical film 6, the optical film except that the sub resins A-1 and A-5 shown in Table 2 (see Chemical formula 33 and Chemical formula 34) were added in addition to the resin (A), respectively. Optical films 16 and 17 were produced in the same manner as in the production of 6.

≪Evaluation≫
(1. Measurement of moisture permeability)
According to JIS Z-0208, the moisture permeability (g / m ² / 24h) of optical films 1 to 17 was measured in an environment of 80 ° C. and 90% RH, and evaluated according to the following criteria.
<Evaluation criteria>
◎: moisture permeability is less than 1300g / m ² / 24h.
○: moisture permeability is less than 1300g / m ² / 24h or more 2000g / m ² / 24h.
△: moisture permeability is less than 2000g / m ² / 24h or more 2500g / m ² / 24h.
×: it moisture permeability 2500g / m ² / 24h or more.

(2. Measurement of pencil hardness)
The prepared optical films 1 to 17 were conditioned for 2 hours or more at a temperature of 23 ° C. and a relative humidity of 55%, and then specified by JIS K5400 with a weight of 500 g using a test pencil specified by JIS S 6006. The pencil hardness of the cured layer was measured according to the pencil hardness evaluation method to be evaluated based on the following criteria.
<Evaluation criteria>
A: Pencil hardness is H or more.
○: Pencil hardness is 0.5H or more and less than H.
Δ: Pencil hardness is F or more and less than 0.5H ×: Pencil hardness is less than F

Tables 1 and 2 show the evaluation results of the optical films 1 to 17 and the physical properties such as the first acid dissociation constant pKa ₁ of the compound (B). As a method for measuring the acid dissociation constant, the alkali titration method described on pages 215 to 217 of the second edition of Experimental Chemistry Course published by Maruzen Co., Ltd. was adopted.

As shown in Table 1, the maximum number of atoms arranged in a straight line as a spacer connecting two active energy groups is 8 or more, and the spacer does not contain a ring structure, and the spacer has a ring structure. In addition, the optical film of the example having the compound (B) having a first acid dissociation constant pKa ₁ of 1.0 or more and 7.0 or less has low moisture permeability (evaluation is 80 ° C. and 90% RH). Therefore, it can be said that a decrease in the durability of the polarizer can be suppressed by suppressing a decrease in the protective function of the polarizer in a high temperature and high humidity environment.

In particular, from the results of

optical films

5, 6, 14, and 15, from the viewpoint of reliably suppressing deterioration of moisture permeability, the compound (B) is a compound having a molecular weight of 130 to 500 (for example, F-2, G- 3) is desirable.

From Table 2, it can be said that it is desirable to add a sub-resin (see A-1 and A-5) containing a compound having a ring structure in the molecule and having an active energy group from the viewpoint of improving pencil hardness. .

In addition, in the above-mentioned Example, since it is a premise that a film base material is a thin film, the above-mentioned effect is acquired by using the 15-micrometer-thick cellulose-ester film as a film base material. If the thickness of the film substrate is in the range of 5 μm or more and less than 35 μm, even if it is a film thickness other than 15 μm, there is no change to the thin film, so that the same effect as the above-described embodiment can be obtained. Guessed.

The optical film, polarizing plate, and image display device of the present embodiment described above can be expressed as follows.

1. An optical film having a cured layer on at least one surface of a transparent substrate,
The transparent substrate is a cellulose film having a film thickness of 5 μm or more and less than 35 μm,
The cured layer is
At least one kind of active energy ray-curable resin (A), wherein the maximum number of atoms arranged in a straight line as a spacer connecting two active energy groups is 8 or more, and the spacer does not contain a ring structure; ,
An optical film comprising a ring structure and at least one compound (B) having a first acid dissociation constant pKa ₁ of 1.0 or more and 7.0 or less.

2. 2. The optical film as described in 1 above, wherein the molecular weight of the compound (B) is 130 or more and 500 or less.

3. The cellulose-based film is a cellulose ester film, and a polymer containing a repeating unit derived from a monomer represented by the following general formula (P), an organic acid represented by the following general formula (Q), 3. The optical film as described in 1 or 2 above, which contains at least one of the compounds represented by formula (S).

(In the general formula (P), R ¹ represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R ² represents a substituent. (A) is necessary for forming a 5- or 6-membered ring. Represents an atomic group, and n represents an integer of 0 to 4.)

(In general formula (Q), R ²⁶ represents an aryl group, and R ²⁷ and R ²⁸ each independently represents a hydrogen atom, an alkyl group, or an aryl group.)

(In the general formula (S), R ¹ represents a hydrogen atom or a substituent, R ² represents a substituent represented by the following general formula (a). N1 represents an integer of 0 to 4, and n1 is 2 In the above, a plurality of R ¹ may be the same or different from each other, n2 represents an integer of 1 to 5, and when n2 is 2 or more, a plurality of R ² may be the same or different from each other May be.)

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

(In the general formula (b), X represents a substituted or unsubstituted aromatic ring, and R ⁶ , R ⁷ , R ⁸ , and R ⁹ are each independently a hydrogen atom or an alkyl having 1 to 5 carbon atoms. N5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R ⁶ , R ⁷ , R ⁸ and X may be the same or different.

4. 2. The optical film as described in any one of 1 to 3, wherein two or more hardened layers are provided.

5. 5. A polarizing plate, wherein the optical film according to any one of 1 to 4 is bonded to one surface of a polarizer.

6. 6. An image display device, wherein the polarizing plate according to 5 is provided on at least one surface side of the display cell.

The optical film of the present invention can be used for image display devices such as polarizing plates and liquid crystal display devices.

1 Image display device 4 Liquid crystal cell (display cell)
5 Polarizing plate 11 Polarizer 12 Film substrate (transparent substrate, cellulose film)
13 Hardened layer 15 Optical film

Claims

An optical film having a cured layer on at least one surface of a transparent substrate,
The transparent substrate is a cellulose film having a film thickness of 5 μm or more and less than 35 μm,
The cured layer is
At least one kind of active energy ray-curable resin (A), wherein the maximum number of atoms arranged in a straight line as a spacer connecting two active energy groups is 8 or more, and the spacer does not contain a ring structure; ,
An optical film comprising a ring structure and at least one compound (B) having a first acid dissociation constant pKa 1 of 1.0 or more and 7.0 or less.
The optical film according to claim 1, wherein the molecular weight of the compound (B) is 130 or more and 500 or less.
The cellulose-based film is a cellulose ester film, and a polymer containing a repeating unit derived from a monomer represented by the following general formula (P), an organic acid represented by the following general formula (Q), The optical film according to claim 1, comprising at least one of the compounds represented by formula (S).

(In the general formula (P), R 1 represents a hydrogen atom or an aliphatic group having 1 to 4 carbon atoms. R 2 represents a substituent. (A) is necessary for forming a 5- or 6-membered ring. Represents an atomic group, and n represents an integer of 0 to 4.)

(In general formula (Q), R 26 represents an aryl group, and R 27 and R 28 each independently represents a hydrogen atom, an alkyl group, or an aryl group.)

(In the general formula (S), R 1 represents a hydrogen atom or a substituent, R 2 represents a substituent represented by the following general formula (a). N1 represents an integer of 0 to 4, and n1 is 2 In the above, a plurality of R 1 may be the same or different from each other, n2 represents an integer of 1 to 5, and when n2 is 2 or more, a plurality of R 2 may be the same or different from each other May be.)

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

(In the general formula (b), X represents a substituted or unsubstituted aromatic ring, and R 6 , R 7 , R 8 , and R 9 are each independently a hydrogen atom or an alkyl having 1 to 5 carbon atoms. N5 represents an integer of 1 to 11, and when n5 is 2 or more, a plurality of R 6 , R 7 , R 8 and X may be the same or different.
The optical film according to any one of claims 1 to 3, wherein two or more hardened layers are provided.
A polarizing plate, wherein the optical film according to any one of claims 1 to 4 is bonded to one surface of a polarizer.
6. An image display device, wherein the polarizing plate according to claim 5 is provided on at least one surface side of the display cell.