JP2003107201A - Optical film, protective film for polarizing plate, optical retardation film, polarizing plate, method for manufacturing optical film, method for manufacturing polarizing plate, method for manufacturing protective film of polarizing plate and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film which can prevent the degradation of the flatness of a cellulose ester film. SOLUTION: The optical film contains a cellulose ester film. A metal compound layer containing at least either oxygen atoms or nitrogen atoms and metal atoms is formed directly or with another layer interposed on at least one surface of the cellulose ester film.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an optical film including a cellulose ester film, a polarizing plate protective film, a retardation film, a polarizing plate, a method for producing the optical film, and a method for producing the polarizing plate. The present invention relates to a method for producing the polarizing plate protective film, and a display device including the optical film.

[0002]

2. Description of the Related Art Cellulose ester films are used in various optical films such as polarizing plate protective films, retardation films and optical compensation films because they have excellent optical properties. For example, Japanese Patent Laid-Open No. 2000-3526
The optical film described in Japanese Patent No. 20 has a cellulose ester film formed by melt casting. With this configuration, an optical film having excellent optical, physical and dimensional stability can be obtained.

[0003]

By the way, the cellulose ester film is often stored in a rolled state, which causes deterioration of the flatness of the film.

The cellulose ester film also contains
Usually, additives such as a plasticizer and an ultraviolet absorber are included. These additives are added to improve the processability and moisture permeability of the cellulose ester film. However, on the other hand, the inclusion of these additives causes a problem that the coating properties of various coating layers on the cellulose ester film are deteriorated. In particular, there has been a problem that the storage stability of the unprocessed cellulose ester film is deteriorated due to bleed-out of these additives and change in physical properties due to volatilization.

Further, there is a problem that the cellulose ester film absorbs water and expands or contracts. In particular, when knurling is applied to the film end in a long roll film,
Swelling due to moisture absorption causes the film to stretch or sag, which may cause the film to have irregularities, streaks, folds, or wrinkles. This problem is remarkable especially in a thin film, and improvement has been demanded.

An object of the present invention is to provide an optical film capable of preventing the flatness of a cellulose ester film from deteriorating.
Provided is a polarizing plate protective film, a retardation film, a polarizing plate, and a method for producing an optical film, a method for producing a polarizing plate, a method for producing a polarizing plate protective film, and a display device including the optical film, which are formed using the same. That is. Further, another object is to improve the coating property on the cellulose ester film, the storage stability of the long roll-shaped cellulose ester film, and prevent moisture absorption by the cellulose ester film. Further, it is to provide a polarizing plate which suppresses the retardation variation of the retardation film and has excellent durability.

[0007]

In order to solve the above-mentioned problems, the invention according to claim 1 is an optical film comprising a cellulose ester film, wherein an oxygen atom (O) and a nitrogen atom (N ), And a metal compound layer containing at least one of the above, and a metal atom,
The optical film is provided on at least one surface of the cellulose ester film directly or via another layer.

The invention according to claim 2 is the optical film according to claim 1, wherein the thickness of the cellulose ester film is 10 to 500 μm. The invention according to claim 3 is the optical film according to claim 1 or 2, wherein the thickness of the metal compound layer is 0.005 to 1 µm.

According to a fourth aspect of the present invention, in the optical film according to any one of the first to third aspects, the metal atom contained in the metal compound layer is a silicon atom (Si), and the number of the metal atom is When the ratios of the numbers of oxygen atoms and nitrogen atoms contained in the metal compound layer are x and y, respectively, x is 0 or more and 2 or less, and y is 0 or more and 4/3 or less. To do.

According to a fifth aspect of the invention, in the optical film according to any one of the first to fourth aspects, the metal compound layer is provided on both surfaces of the cellulose ester film, either directly or via another layer. It is characterized by The invention according to claim 6 is the optical film according to claim 5, wherein the thickness of the metal compound layer provided on one surface of the cellulose ester film is the same as that of the metal compound layer provided on the other surface of the cellulose ester film. It is characterized by being thicker than the film thickness.

The invention according to claim 7 is the optical film according to any one of claims 1 to 6, characterized in that the metal compound layer contains carbon atoms. The invention according to claim 8 is the optical film according to claim 7, wherein the content of carbon atoms in the metal compound layer is 0.1 to 10% by mass.

According to a ninth aspect of the invention, in the optical film according to any one of the first to eighth aspects, a resin layer is provided on at least one metal compound layer directly or via another layer. It is characterized by being According to a tenth aspect of the invention, in the optical film according to the ninth aspect, the resin layer is an actinic ray curable resin layer or a thermosetting resin layer.

The invention according to claim 11 is the invention according to claims 1 to 10.
The optical film as described in any one of 1 to 3, wherein the thickness of the metal compound layer is greater than 0.1 μm and is 0.8 μm.
It is characterized by being m or less. The invention according to claim 12 is the optical film according to any one of claims 1 to 11, wherein the cellulose ester film has a thickness of 10 to 6
It is characterized in that it is 0 μm.

The invention according to claim 13 is the invention according to claims 1 to 12.
The optical film according to any one of items 1 to 3, wherein the cellulose ester film has a laminated structure formed by a co-casting method. According to a fourteenth aspect of the present invention, in the optical film according to any one of the first to thirteenth aspects, knurling having a height of 25% or less of a film thickness of the cellulose ester film is provided at an end portion. Is characterized by.

The invention as defined in claim 15 is defined by claim 1 through claim 14.
A polarizing plate protective film comprising the optical film according to any one of 1. The invention according to claim 16 is configured using the optical film according to any one of claims 1 to 14, and has a retardation value (Rt value) in the film thickness direction defined by the following formula (1) of 7:
0 to 300 nm or a retardation value (Ro value) in the in-plane direction defined by the following formula (2) is 40 to 1000.
or a Rt value of 70 to 300 nm and a Ro value of 40 to 1000 nm. Rt value _{= ((n x + n y} ) / 2-n z) × d ... (1) Ro value _{= (n x -n y) ×} d ... (2) (n x is a refractive index in the film plane is most Refractive index in the larger direction, n _y is the in-plane refractive index in the direction perpendicular to n _x ,
_nz represents the refractive index in the thickness direction of the film, and d represents the thickness (nm) of the film. )

The invention according to claim 17 is a polarizing plate comprising the polarizing plate protective film according to claim 15. The invention according to claim 18 is the polarizing plate according to claim 17, wherein from at least one surface, an actinic ray curable resin layer, a metal compound layer having a film thickness of 0.01 to 1 μm, a cellulose ester film, a polarizer, It is characterized by having a laminated structure in which a cellulose ester film and a metal compound layer having a film thickness of 0.01 to 1 μm are laminated in this order.

According to a nineteenth aspect of the present invention, a solution containing a cellulose ester is cast on a support, peeled and dried, and when the residual solvent amount is 3 to 40% by mass, 1. Oxygen atoms and nitrogen atoms are drawn by atmospheric pressure plasma treatment while supplying a reaction gas containing a silicon compound to at least one surface of the cellulose ester film obtained by stretching the film by 00 to 2.0 times and further drying. A method for producing an optical film, which comprises providing a metal compound layer containing at least one of the above and a silicon atom.

According to a twentieth aspect of the present invention, in the method for producing an optical film according to the nineteenth aspect, the atmospheric pressure plasma treatment is performed at a high frequency voltage exceeding 100 kHz and for 1 W.
It is characterized in that it is performed by supplying electric power of / cm ² or more and discharging. The invention according to claim 21 is the method for producing an optical film according to claim 19 or 20, characterized in that an actinic radiation curable resin layer is provided on at least one metal compound layer directly or through another layer. And

The invention according to claim 22 is a method according to claims 19 to 2.
1. A method for producing a polarizing plate, which comprises subjecting an optical film produced by the method for producing an optical film according to any one of 1 to saponification treatment and laminating it with a polarizer.

In a twenty-third aspect of the present invention, a solution containing a cellulose ester is cast on a support, peeled and dried, and when the residual solvent amount is 3 to 40% by mass, 1. The film is stretched by 00 to 2.0 times and further dried, and both surfaces of the cellulose ester film thus obtained are saponified. Then, one surface saponified is left, and the other surface saponified is subjected to atmospheric pressure plasma. A method for producing a polarizing plate protective film, comprising providing a metal compound layer containing at least one of an oxygen atom and a nitrogen atom and a silicon atom by treatment.

The invention according to claim 24 is a polarizing plate protective film containing a cellulose ester film, a polarizer,
A method for manufacturing a polarizing plate, which comprises laminating a polarizing plate, to bond the polarizing plate protective film to the polarizing plate before or after the polarizing plate protective film is bonded to the polarizing plate protective film. Accordingly, a metal compound layer including at least one of an oxygen atom and a nitrogen atom and a silicon atom is provided. Claim 25
The described invention is a display device including the optical film according to any one of claims 1 to 14.

The present invention will be described in detail below. The optical film of the present invention is configured to include a cellulose ester film, and an oxygen atom (O) and a nitrogen atom (N) can be formed on one surface or both surfaces of the cellulose ester film directly or through another layer. )) And a metal compound layer including a metal atom.

Here, the "metal compound layer containing at least one of oxygen atom (O) and nitrogen atom (N) and a metal atom" is a metal oxide, a metal oxynitride, Either a metal nitride or a mixture of two or more of these may be used.

If the metal compound layer is too thin, the effect is poor, and if it is too thick, problems such as cracks and cracks occur. Therefore, the film thickness is preferably about 0.005 to 1 μm, and particularly 0.1 μm. Greater than and 0.8μ
The thickness is preferably m or less, more preferably 0.5 μm or less, and particularly preferably 0.2 μm or less. The metal compound layer is preferably a layer thicker than the SiO ₂ layer forming the antireflection layer.

Examples of the metal atom contained in the metal compound layer include silicon (Si), aluminum (Al), titanium (Ti), zinc (Zn), zirconium (Zr),
Examples include magnesium (Mg), tin (Sn), copper (Cu), iron (Fe), germanium (Ge),
Particularly, silicon atom (Si) is preferable. When the metal atom contained in the metal compound layer is a silicon atom, x is 0 or more and 2 when the ratios of the number of oxygen atoms and the number of nitrogen atoms to the number of silicon atoms in the metal compound layer are x and y, respectively. And y is 0 or more and 4/3 or less.

The metal compound layer preferably contains a predetermined amount of carbon atoms (C). Thereby, the flexibility of the film and the adhesiveness at the time of stacking can be obtained. here,
The carbon content of the metal compound layer is preferably 0.1 to 10% by mass, more preferably 0.2 to 8% by mass, and particularly preferably 0.2 to 5% by mass.
If the carbon content is less than 0.1% by mass, the flexibility of the film tends to be insufficient, and if it is more than 10% by mass, the improvement effect due to the provision of the metal compound layer decreases, and This is not preferable because the required film thickness becomes thick.

The metal compound layer can be formed by various methods such as vapor deposition, sputtering, plasma CVD and vacuum plasma, but it is particularly preferable to form it by atmospheric pressure plasma treatment. The atmospheric pressure plasma treatment is performed, for example, in Japanese Patent Application No. 2001-127649 or Japanese Patent Application No. 2001-1.
It can be performed by the processing method and apparatus described in No. 31663.

In the atmospheric pressure plasma treatment, the reaction gas is brought into a plasma state by discharging between the opposing electrodes under the atmospheric pressure or a pressure near the atmospheric pressure, and the cellulose ester film is exposed to the reaction gas in the plasma state. Forming a metal compound layer on the cellulose ester film.

In the atmospheric pressure plasma treatment, in order to obtain a high plasma density and increase the film forming rate, it is preferable to supply a certain amount of high power with a high frequency voltage, and a high frequency voltage exceeding 100 kHz is applied between the opposing electrodes. 1 W / c
It is preferable to supply electric power of m ² or more to excite the reaction gas and generate plasma. By applying such a high-power electric field, a dense, highly functional thin film with high film thickness uniformity can be obtained with high production efficiency.

The frequency of the high frequency voltage applied between the opposing electrodes is preferably 150 MHz or less. The frequency of the high frequency voltage is preferably 200 kHz or higher, more preferably 800 kHz or higher. The power supplied between the electrodes facing each other is preferably 1.2 W / cm.
² or more, preferably 50 W / cm ² or less, and more preferably 20 W / cm ² or less. The voltage application area (/ cm ² ) at the electrodes facing each other indicates the area in which discharge occurs. The high-frequency voltage applied between the electrodes facing each other may be an intermittent pulse wave or a continuous sine wave, but in order to obtain the effect of the present invention high, it is a continuous sine wave. It is preferable.

After the cellulose ester film-forming step by the solution casting method and before winding the cellulose ester film, it is preferable to continuously form the metal compound layer by atmospheric pressure plasma treatment.

An example of a plasma discharge treatment apparatus used for forming a thin film of a metal compound layer by atmospheric pressure plasma treatment will be described below with reference to FIG. The plasma discharge treatment apparatus 1 has a rotary electrode 2 and a plurality of counter electrodes 3 arranged to face the rotary electrode 2. The original film roll (not shown) or the base film F conveyed from the previous step is guided to the rotary electrode 2 through the guide roll 4 and the nip roll 5, and is brought into contact with the rotary electrode 2 to rotate the rotary electrode 2.
It is designed to be transferred in synchronization with the rotation of the.

The reaction gas G prepared by the reaction gas generator 7 is supplied from the air supply pipe 8 to the discharge part 6 under atmospheric pressure or a pressure in the vicinity thereof, and the discharge part 6 faces the counter electrode 3. A thin film (metal compound layer) is formed on the surface of the base film F on the side where the film is formed. Although not shown in FIG. 1, in order to supply the reaction gas G at a uniform concentration and flow rate in the width direction of the base film F, the reaction gas G is provided between the respective counter electrodes 3. It is desirable that a plurality of air supply pipes 8 to be introduced are provided.

A power supply 9 capable of applying a voltage for generating plasma discharge is connected to the rotary electrode 2 and the counter electrode 3 via voltage supply means 10 and 11. The rotating electrode 2, the counter electrode 3, and the discharge part 6 are the plasma discharge processing container 12
It is covered with and is isolated from the outside world. The exhaust gas G ′ used for the treatment is the gas exhaust port 13 at the top of the treatment chamber.
Is to be discharged from. Further, the exhaust gas G ′ is supplied from a gas exhaust port (not shown) provided between the counter electrodes 3.
Can be exhausted.

Base film F subjected to plasma discharge treatment
Is conveyed through the nip roll 14 and the guide roll 15 to the next step or a winding roll (not shown). In order to block the air that is entrained from the outside and accompanies the base film F, and also to prevent the air from entering the inside at the outlet, the nip rolls 514 of the plasma discharge processing container 12 are placed in and out. However, it is desirable that partition plates 16 and 17 from the outside are provided. The above-mentioned entrained air is preferably suppressed to 1% by volume or less, more preferably 0.1% by volume or less with respect to the total volume of the gas in the plasma discharge processing container 12. This can be achieved with the nip roll 5.

The pressure inside the plasma discharge treatment container 12 is preferably high, and the pressure outside is preferably +0.1 kPa or more, and more preferably 0.3 to 10 kPa. Although not shown, the rotary electrode 2 and the counter electrode 3 circulate a temperature-controlled medium for temperature adjustment, if necessary. As a medium,
Insulating materials such as distilled water and oil can be preferably used.

The value of the voltage applied from the power source 9 to the counter electrode 3 is appropriately determined. For example, the voltage is 0.5 to 10 k.
At about V, the power supply frequency exceeds 100 kHz and 150M
It is preferably adjusted to Hz or less. Here, as a voltage application method, a continuous sine wave continuous oscillation mode called a continuous mode and an ON state called a pulse mode are used.
Either of the intermittent oscillation modes in which ON / OFF is intermittently performed may be adopted, but the continuous mode can obtain a denser and higher quality thin film. The power source 9 for applying a voltage between the opposing electrodes is, for example, a high frequency power source (2
00kHz), high frequency power supply made by Pearl Industry (800kHz)
z), a high frequency power source (13.56 MHz) manufactured by JEOL Ltd., a high frequency power source (150 MHz) manufactured by Pearl Industrial Co., Ltd. can be used, but the invention is not particularly limited thereto.

The electrode interval of the discharge part 6 is the thickness of the solid dielectric (not shown) installed on the base material of the electrode, the applied voltage and frequency,
It is determined in consideration of the purpose of using plasma.
The shortest distance between the solid dielectric and the electrode when the solid dielectric is installed on one of the electrodes (electrodes 2 and 3) and the distance between the solid dielectrics when the solid dielectric is installed on both of the electrodes are:
From the viewpoint of uniform discharge, 0.5 mm in each case
~ 20 mm is preferable, and more preferably 0.5-5 mm.
And particularly preferably 1 mm ± 0.5 mm.

As the plasma discharge processing container 12, a processing container made of Pyrex (R) glass or plastic is preferably used, but a metallic one can be used as long as it can be insulated from the electrodes. For example, a polyimide resin or the like may be attached to the inner surface of an aluminum or stainless steel frame, and the metal frame may be sprayed with ceramics to have an insulating property.

Further, during discharge plasma treatment, the physical properties and composition of the thin film obtained may change depending on the temperature of the base film, and in order to suppress the influence on the base film to a minimum, during the discharge plasma treatment It is preferable to appropriately control the temperature of the base film. The temperature of the substrate film varies depending on the processing conditions, but is preferably room temperature to 200 ° C, more preferably room temperature to 120 ° C. More specifically, it is preferable to adjust the temperature to room temperature (15 to 25 ° C.) or higher and lower than 200 ° C., more preferably 50 ° C. or higher and 15
The temperature should be adjusted to less than 0 ° C, more preferably 60 ° C.
As described above, the temperature is adjusted to less than 120 ° C. In order to adjust the temperature within the above range, the electrodes and the base material film are subjected to discharge plasma treatment while being cooled or heated by a cooling means, if necessary.

The above discharge plasma treatment is carried out at or near atmospheric pressure. Here, near atmospheric pressure is 20
It represents a pressure of kPa to 200 kPa. In order to preferably obtain the effect described in the present invention, 90 to 110 kPa, particularly 93 kPa to 104 kPa are preferable.

In the discharge electrodes (electrodes 2 and 3) used in the atmospheric pressure plasma treatment, at least the surface of the electrode which is in contact with the base film F is JIS B 060.
Maximum height of surface roughness (Rmax) specified in 1 is 10μ
The surface roughness is preferably adjusted to m or less, and the maximum surface roughness is preferably 8 μm or less, more preferably 7 μm or less.

The surface of the electrode is preferably coated with a solid dielectric material, and in particular, the conductive base material such as metal is preferably coated with the solid dielectric material. Examples of solid dielectrics include plastics such as polytetrafluoroethylene and polyethylene terephthalate, glass, silicon dioxide, aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), and other metal oxides,
Examples thereof include double oxides such as barium titanate. In particular, a ceramic-coated dielectric material obtained by performing a pore-sealing treatment using an inorganic material after spraying ceramics is preferable. Here, examples of the conductive base material such as metal include metals such as silver, platinum, stainless steel, aluminum and iron, and stainless steel is preferable from the viewpoint of processing. As the lining material, silicate glass,
Borate glass, phosphate glass, germanate glass, tellurite glass, aluminate glass, vanadate glass, etc. are preferably used, but among these, borate glass is processed. Since it is easy, it is more preferably used.

The above-mentioned electrode can be heated or cooled from the back side (inside) of the electrode, if necessary. When the electrode is a belt, it can be cooled with gas from the back surface, but in the rotating electrode 2 using a roll, the medium is supplied inside to control the temperature of the electrode surface and the temperature of the base film. Is preferred.

During the plasma discharge treatment, it is desirable to control the temperature inside the rotary electrode 2 using a roll in order to prevent temperature unevenness of the base film in the width direction or the longitudinal direction as much as possible. . Temperature unevenness is ± 10 ° C
Is preferably within ± 5 ° C., more preferably within ± 5 ° C., more preferably within ± 1 ° C., and most preferably within ± 0.1 ° C.

Reaction gas G used in atmospheric pressure plasma treatment
Is basically a reaction gas in which an inert gas and a reactive gas for forming the thin film are mixed, although it depends on the type of the thin film to be provided on the base film F. The reactive gas is preferably contained in the reaction gas in an amount of 0.01 to 10% by volume.

As the above-mentioned inert gas, the 18th of the periodic table is used.
Group elements, such as helium, neon, argon, krypton, xenon, and radon, are mentioned, but helium and argon are preferably used in order to obtain the effects described in the present invention.

As the reactive gas, a metal compound is used, and an organic metal compound such as a metal hydrogen compound or a metal alkoxide is preferably used. Further, in order to introduce these organometallic compounds between the electrodes which are the discharge spaces, they may be in a gas, liquid or solid state at normal temperature and pressure. In the case of gas, it can be introduced into the discharge space as it is, and in the case of liquid or solid, it is used by being vaporized by means such as heating, decompression, and ultrasonic irradiation. The metal compound gas is preferably contained in the reaction gas in an amount of 0.01 to 10% by volume, more preferably 0.1 to 5% by volume.

By using a silicon compound as the metal compound gas and performing atmospheric pressure plasma treatment while supplying a reaction gas containing this, a metal compound layer containing silicon atoms can be formed. Here, as the above-mentioned silicon compound, for example, general formula Si (OR1) ₄ (R1 is an alkyl group, preferably an alkyl group having 1 to 5 carbon atoms) and general formula (R2) _n Si ( OR3) _4-n (R2 and R3 are alkyl groups, preferably alkyl groups having 1 to 5 carbon atoms, and n is an integer of 1 to 3.)
Examples include organic silicon compounds represented by and silane (SiH ₄ ). Specifically, tetraethoxysilane (T
EOS), hexamethyldisiloxane (HMDSO),
Tetramethyldisiloxane (TMDSO), octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, ethyltrimethoxysilane, ethyltri Ethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane, n-hexyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltri Examples include ethoxysilane and decamethylcyclopentasiloxane. In addition, 1,1,3,3-tetramethyldisilazane, 1,3-bis (chloromethyl)
-1,1,3,3-tetramethyldisilazane, hexamethyldisilazane, 1,3-divinyl-1,1,3,3-
Tetramethyldisilazane, aminomethyltrimethylsilane, dimethyldimethylaminosilane, dimethylaminotrimethylsilane, allylaminotrimethylsilane, diethylaminodimethylsilane, 1-trimethylsilylpyrrole, 1-trimethylsilylpyrrolidine, isopropylaminomethyltrimethylsilane, diethylaminotrimethylsilane, anilino Trimethylsilane, 2-piperidinoethyltrimethylsilane, 3-butylaminopropyltolumethylsilane, 3-piperidinopropyltrimethylsilane, bis (dimethylamino) methylsilane, 1-trimethylsilylimidazole, bis (ethylamino) dimethylsilane, Bis (dimethylamino) dimethylsilane, bis (butylamino) dimethylsilane, 2-aminoethylaminomethyl Methylphenyl silane, 3- (4
-Methylpiperazinopropyl) trimethylsilane, dimethylphenylpiperazinomethylsilane, butyldimethyl-3-piperazinopropylsilane, dianilinodimethylsilane, bis (dimethylamino) diphenylsilane and the like can also be used. Further, the above silicon compounds may be mixed at a predetermined ratio, such as a mixture of methyltrimethoxysilane and TEOS at a ratio of 1: 1 and a mixture of ethyltriethoxysilane and TEOS at a ratio of 1: 2. . By further combining these organosilicon compounds with oxygen gas, nitrogen gas, or the like at a predetermined ratio, a metal compound layer containing at least one of O atom and N atom and Si atom can be formed.

The reaction gas preferably contains 0.0 or more components selected from oxygen, ozone, hydrogen peroxide, carbon dioxide, carbon monoxide, nitric oxide, nitrogen dioxide, hydrogen and nitrogen.
By containing 1 to 10% by volume, more preferably 0.1 to 5% by volume, the reaction can be promoted, the hardness of the thin film can be significantly improved, and a dense and high-quality thin film can be formed. . In particular, it is preferable to add oxygen or hydrogen.

As described above, by providing the metal compound layer on at least one surface of the cellulose ester film directly or via another layer, the storage stability of the wound roll-shaped cellulose ester film is remarkably improved. After winding, before providing various functional layers such as an antiglare layer, a clear hard coat layer and an antireflection layer,
It is possible to provide a roll-shaped cellulose ester film that does not deteriorate in flatness and surface quality. In particular, when the metal compound layer is formed by atmospheric pressure plasma treatment, a dense and dense film is formed, so that moisture absorption by the cellulose ester film can be prevented, and the strength is high,
An optical film having excellent scratch resistance can be provided.

The optical film of the present invention is preferably used as a polarizing plate protective film. Incidentally, conventionally, the cellulose ester film has been preferably used as a polarizing plate protective film. This is because the saponification treatment provides excellent adhesion to the polarizing plate.

A polarizing plate can be manufactured by subjecting the optical film of the present invention to a saponification treatment and bonding it to a polarizer. Here, it is particularly preferable that the optical film (polarizing plate protective film) attached to the polarizer is provided with metal compound layers on both sides. In the optical film of the present invention, if the metal compound layer is provided on at least one surface of the cellulose ester film, the above effect can be expected, so do not provide the metal compound layer on the surface to be saponified. You can also keep it. Further, in the optical film, when the metal compound layer is provided on both sides of the cellulose ester film, the metal compound layer on the side to be bonded to the polarizer is dissolved by a strong saponification treatment, which causes an obstacle to the production of a polarizing plate. Can be prevented.

The metal compound layer on at least one surface of the cellulose ester film can be left after the saponification treatment by controlling the saponification treatment conditions and the film formation conditions of the metal compound layer. Here, when providing the metal compound layer on both sides of the cellulose ester film, the thickness of the metal compound layer provided on one surface of the cellulose ester film, than the thickness of the metal compound layer provided on the other surface It is preferable to make it thick. Thereby, the thin metal compound layer and the surface of the cellulose ester film on the side where the metal compound layer is provided can be dissolved by the saponification treatment, and the thick metal compound layer is partially dissolved by the saponification treatment. But you can leave it.

As described above, the durability of the polarizing plate can be remarkably improved by using the optical film having the metal compound layer as the polarizing plate protective film.
The saponification treatment of the optical film provided with a metal compound layer in advance is not limited to the case of laminating with a polarizer, and after saponifying both surfaces of the cellulose ester film, one side subjected to saponification is left, A metal compound layer may be formed on the other surface by atmospheric pressure plasma treatment to prepare a polarizing plate protective film, and the polarizing plate protective film may be bonded to a polarizer. Further, not only in the case of producing a polarizing plate by laminating an optical film and a polarizer provided with a metal compound layer, after the polarizing plate protective film containing a cellulose ester film and the polarizer are laminated, Even when the metal compound layer is provided on the plate protective film by atmospheric pressure plasma, the durability of the polarizing plate can be improved.

In order to obtain more stable durability, it is more preferable to provide a resin layer directly or through another layer on the metal compound layer provided on the optical film. here,
Since the optical compound is provided with the metal compound layer, coating failure such as coating unevenness or brushing is less likely to occur, and the coating process is easy. Therefore, the optical film of the present invention is more preferably provided with the resin layer.

The resin layer is preferably a thermoplastic resin layer, an actinic ray curable resin layer, or a thermosetting resin layer, and particularly preferably an actinic ray curable resin layer. Here, the actinic radiation curable resin layer refers to a layer containing as a main component a resin which is cured by a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays and electron beams. The actinic radiation curable resin layer or the thermosetting resin layer may be provided as an antiglare layer or a clear hard coat layer. Further, an antireflection layer or an antifouling layer can be further provided on these resin layers.

The actinic radiation curable resin layer such as the antiglare layer or the clear hard coat layer is preferably a resin layer formed by polymerizing a component containing an ethylenically unsaturated monomer. Typical examples of the actinic ray curable resin include an ultraviolet curable resin and an electron beam curable resin.
In addition, a resin that is cured by irradiation with active rays other than ultraviolet rays and electron beams may be used.

Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin. Etc. can be mentioned.

The ultraviolet curable acrylic urethane resin is
In general, a product obtained by reacting a polyester polyol with an isocyanate monomer, or a prepolymer, further includes 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter, when described as acrylate, methacrylate is included), Two
It can be easily obtained by reacting an acrylate-based monomer having a hydroxyl group such as -hydroxypropyl acrylate (for example, JP-A-59-1511).
No. 10, etc.).

The UV-curable polyester acrylate resin can generally be easily obtained by reacting a polyester polyol with 2-hydroxyethyl acrylate or 2-hydroxy acrylate monomer (for example, JP-A-59-151112). See the bulletin).

As a specific example of the ultraviolet-curable epoxy acrylate resin, an epoxy acrylate as an oligomer, to which a reactive diluent and a photoreaction initiator are added and reacted, can be mentioned. Kaihei 1
-105738). Examples of the photoreaction initiator include benzoin derivatives, oxime ketone derivatives, benzophenone derivatives, thioxanthone derivatives,
One kind or two or more kinds can be selected and used.

Specific examples of the UV-curable polyol acrylate resin include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and alkyl-modified dipenta. Examples thereof include erythritol pentaacrylate.

These resins are usually used together with a known photosensitizer. The above photoreaction initiator can also be used as a photosensitizer. Specific examples of the photosensitizer include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. When using an epoxy acrylate-based photoreactive agent, n-butylamine, triethylamine, tri-n
-A sensitizer such as butylphosphine can be used.
The photoreaction initiator or photosensitizer contained in the ultraviolet curable resin composition excluding the solvent component which volatilizes after coating and drying can be added in an amount of usually 1 to 10% by mass of this composition, and the addition amount is 2 It is more preferably 0.5 to 6 mass%.

As the resin monomer, for example, a monomer having one unsaturated double bond such as methyl acrylate,
Common monomers such as ethyl acrylate, butyl acrylate, vinyl acetate, benzyl acrylate, cyclohexyl acrylate and styrene can be mentioned. Further, as a monomer having two or more unsaturated double bonds, ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-
Cyclohexane diacrylate, 1,4-cyclohexyl dimethyl adiacrylate, the above-mentioned trimethylol propane triacrylate, pentaerythritol tetraacrylic ester, etc. can be mentioned.

The UV curable resin is, for example, ADEKA OPTOMER KR / BY series: KR-400, KR-41.
0, KR-550, KR-566, KR-567, BY
-320B (all manufactured by Asahi Denka Kogyo Co., Ltd.), or Koei Hard A-101-KK, A-101-WS,
C-302, C-401-N, C-501, M-10
1, M-102, T-102, D-102, NS-10
1, FT-102Q8, MAG-1-P20, AG-1
06, M-101-C (all manufactured by Koei Chemical Industry Co., Ltd.), or Seika Beam PHC2210 (S), P
HC X-9 (K-3), PHC2213, DP-1
0, DP-20, DP-30, P1000, P110
0, P1200, P1300, P1400, P150
0, P1600, SCR900 (above, manufactured by Dainichiseika Kogyo Co., Ltd.), or KRM7033, KRM703
9, KRM7130, KRM7131, UVECRYL
29201, UVECRYL29202 (above, Daicel UCB Co., Ltd.), or RC-501
5, RC-5016, RC-5020, RC-503
1, RC-5100, RC-5102, RC-512
0, RC-5122, RC-5152, RC-517
1, RC-5180, RC-5181 (above, manufactured by Dainippon Ink and Chemicals, Inc.) or Aurex N
o. 340 Kuriya (Chugoku Paint Co., Ltd.), Sunrad H-601 (Sanyo Kasei Co., Ltd.), SP-1509, SP-1507 (Showa High Polymer Co., Ltd.), or RCC-15C (Grace Japan Co., Ltd.) Company made), Aronix M-6100, M-80
30, M-8060 (above, manufactured by Toagosei Co., Ltd.) or other commercially available ones can be appropriately selected and used.

The actinic radiation curable resin layer can be applied by a known method. As a light source for forming a cured film layer of an actinic ray curable resin by a photocuring reaction, any light source that generates ultraviolet rays can be used, and examples thereof include a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, and carbon. An arc lamp, a metal halide lamp, a xenon lamp, etc. can be used. Irradiation conditions vary depending on each lamp, but the irradiation light amount may be about ²⁰ to 10000 mJ / cm ² , and preferably 50 to 2000 mJ / cm ^2.
Is. From the near-ultraviolet region to the visible light region, it can be used by using a sensitizer having an absorption maximum in that region.

As the solvent for applying the actinic radiation curable resin layer, for example, hydrocarbons, alcohols, ketones,
It can be used by appropriately selecting from esters, glycol ethers and other solvents, or by mixing these. Preferably, propylene glycol mono (1 carbon atom
To 4% alkyl group) alkyl ether or propylene glycol mono (alkyl group having 1 to 4 carbon atoms) alkyl ether ester is 5% by mass or more, more preferably 5 to 8%.
A solvent containing 0% by mass or more is used.

As a method for applying the ultraviolet-curable resin composition coating solution, known methods such as a gravure coater, a spinner coater, a wire bar coater, a roll coater, a reverse coater, an extrusion coater and an air doctor coater can be used. Appropriate application amount is 0.1 to 30 μm in wet film thickness, preferably 0.5 to 15
μm.

The ultraviolet curable resin composition is applied and dried, and then irradiated with ultraviolet rays from a light source. Irradiation time is 0.5 seconds
5 minutes is preferable, and 3 seconds to 2 minutes is more preferable from the viewpoint of curing efficiency and work efficiency of the ultraviolet curable resin.

In order to prevent blocking and to improve scratch resistance and the like, it is preferable to add inorganic or organic fine particles to the obtained cured film layer. For example,
Examples of the inorganic fine particles include silicon oxide, titanium oxide, aluminum oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, calcium sulfate, and the like, and organic fine particles include polymethyl methacrylate. Acrylate resin powder, acrylic styrene resin powder, polymethylmethacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin resin powder, polyester resin powder, Examples thereof include polyamide-based resin powder, polyimide-based resin powder, polyfluorinated ethylene-based resin powder, and the like, and these fine particle powders can be added to the ultraviolet curable resin composition.

The average particle size of these fine particle powders is as follows.
0.005 μm to 45 μm is preferable and 0.01 to 1 μm
Is particularly preferable. Further, it is desirable that the fine particle powder is blended in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of the resin composition (ultraviolet curable resin composition).

The layer obtained by curing the ultraviolet curable resin may be a clear hard coat layer having a center line average roughness Ra of 1 to 50 nm or an antiglare layer having Ra of about 0.1 to 1 μm. . Further, an antireflection layer can be formed on these layers by a known method.

When the actinic radiation curable resin layer is provided on the metal compound layer, the surface hardness of the actinic radiation curable resin layer can be made harder as compared with the case where the metal compound layer is not provided, and the resistance is further improved. An optical film having excellent scratch resistance and pencil hardness can be obtained.

The polarizing plate provided with the resin layer as described above includes, for example, an antireflection layer, an actinic radiation curable resin layer, a metal compound layer, a cellulose ester film, a polarizer, and a cellulose ester from at least one surface. Examples thereof include those having a laminated structure in which a film and a metal compound layer are laminated in this order. Here, the film thickness of the metal compound layer is preferably 0.01 to 1 μm.

The optical film provided with the metal compound layer is also preferably used as a retardation film. When the optical film is used as the retardation film, the retardation value Rt in the film thickness direction is 70 to 300 nm or the retardation value Ro in the in-plane direction is 40 to 10 nm.
It is particularly preferable that the value is 00 nm or the Rt value and the Ro value are within the above ranges. With this configuration, it is possible to extremely reduce the fluctuation of these characteristics due to the environment, and it is possible to provide a retardation film having excellent retardation performance with excellent durability.

By using the optical film of the present invention as a retardation film, various transmissive, semi-transmissive and reflective liquid crystal display devices and various driving systems of TN type, STN type, VA type, OCB type and HAN type can be used. It can be used for a liquid crystal display device, a plasma display, an organic EL display, an inorganic EL display, or other display devices. As a result, it is possible to provide a stable and durable display device in which the fluctuation of the phase difference is small even in a high temperature and high humidity environment, the change in the display performance is small.

In the optical film of the present invention,
The thickness of the cellulose ester film is 10 to 500 μ.
It is preferably m. If the film thickness is less than 10 μm, the mechanical strength will be insufficient, and if it exceeds 500 μm, the handleability and processability will be poor, such being undesirable. The thickness of the cellulose ester film is more preferably 10 to 200 μm, and particularly preferably a thin film of 10 to 60 μm. This is because the effect of providing the metal compound layer is particularly remarkable in the thin cellulose ester film.

The cellulose ester film of the present invention preferably has a laminated structure formed by a co-casting method. More specifically, the cellulose ester film preferably has a constitution of three or more layers having surface layers on both sides of the base layer. Here, fine particles (matting agent) for mainly imparting slipperiness are added to the surface layer, and the base layer contains an ultraviolet absorber and a plasticizer. Of the ultraviolet absorber and the plasticizer, the bleed-out component is preferably added mainly to the base layer. When the plasticizer is not added to the surface layer, or when the addition amount or the component ratio is different, the coating properties of the antiglare layer, the clear hard coat layer, etc. coated thereon may change, but the present invention Then, by providing the metal compound layer, the film can have a certain property, and thus a cellulose ester film having excellent suitability for coating and processing can be provided.

The cellulose as the raw material of the cellulose ester used in the present invention is not particularly limited, but cotton linter, wood pulp, kenaf and the like can be mentioned. In addition, the cellulose ester obtained from these,
Each can be used alone or in a mixture at an arbitrary ratio, but it is preferable to use 50% by mass or more of cotton linter.

The cellulose ester used in the present invention is an organic acid such as acetic acid or methylene chloride when the acylating agent of the cellulose raw material is an acid anhydride (acetic anhydride, propionic anhydride, butyric anhydride). It can be obtained by carrying out the reaction using an organic solvent and a protic catalyst such as sulfuric acid. The acylating agent is acid chloride (CH
₍₃ COCl, C ₂ H ₅ COCl, C ₃ H ₇ COCl) can be obtained by carrying out the reaction using a basic compound such as an amine as a catalyst. Specifically, JP-A-1
It can be synthesized by the method described in 0-45804.

In the synthesis of cellulose ester, the acyl group reacts with the hydroxyl group of the cellulose molecule. The cellulose molecule is composed of a large number of glucose units linked together, and each glucose unit has three hydroxyl groups.
The number of acyl groups derived from these three hydroxyl groups is called the degree of substitution. For example, in cellulose triacetate, an acetyl group is bonded to all three hydroxyl groups of the glucose unit.

The cellulose ester that can be used in the cellulose ester film of the present invention is not particularly limited, but the total acyl group substitution degree is preferably 2.5 to 3.0, and particularly 2.6 to 2 It is preferably 1.9. Among the acyl groups, those having a substitution degree of acetyl group of 1.4 or more are preferably used. The substitution degree of the acyl group can be measured according to ASTM-D817-96.

The cellulose ester according to the present invention includes cellulose acetate such as cellulose triacetate and cellulose diacetate, cellulose acetate propionate, cellulose acetate butyrate, or propionate in addition to acetyl group such as cellulose acetate propionate butyrate. A cellulose ester having a group or a butyrate group bonded thereto is preferable.
As the cellulose ester, in addition to the above examples,
Cellulose acetate phthalate, cellulose nitrate, etc. may also be mentioned. Note that butyrate includes iso-in addition to n-. Cellulose acetate propionate having a large degree of substitution of propionate groups has excellent water resistance.

The number average molecular weight Mn (measurement method described below) of the cellulose ester of the present invention is 70,000 to 250,000.
In the range of 00, the mechanical strength of the obtained film is high,
It also has an appropriate dope viscosity, which is preferable, and further 80,0.
The range of 00 to 150,000 is more preferable. Further, a cellulose ester having a ratio Mw / Mn to the weight average molecular weight Mw of 1.0 to 5.0 is preferably used, and further 1.5
Cellulose esters of ˜4.5 are preferably used.

The number average molecular weight of cellulose ester can be measured by high performance liquid chromatography under the following conditions. Solvent: Acetone column: MPW × 1 (manufactured by Tosoh Corporation) Sample concentration: 0.2 (mass / volume)% Flow rate: 1.0 mL / min Sample injection amount: 300 μL Standard sample: Polymethylmethacrylate (weight average molecular weight 188 , 200) Temperature: 23 ° C

Metals (Ca, Mg, Fe, Na, etc.) in the cellulose ester used during the production of the cellulose ester or mixed in the used material in a small amount.
Is preferably as small as possible, and the total metal content is preferably 100 ppm or less.

Examples of the organic solvent useful for forming a cellulose ester solution or dope in which cellulose ester is dissolved include methylene chloride (methylene chloride), which is a chlorine-based organic solvent, which is a solvent for dissolving cellulose ester, particularly cellulose triacetate. Suitable for Examples of the non-chlorine organic solvent include methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoro. Ethanol, 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
Examples thereof include 3,3-pentafluoro-1-propanol and nitroethane. When using these organic solvents for cellulose triacetate, it is possible to use a dissolution method at room temperature, but it is possible to use a dissolution method such as a high temperature dissolution method, a cooling dissolution method, or a high pressure dissolution method.
Insoluble matter can be reduced, which is preferable.

For cellulose esters other than cellulose triacetate, methylene chloride can be used, but methyl acetate, ethyl acetate and acetone can be preferably used without using methylene chloride. Methyl acetate is particularly preferable. Where:
An organic solvent having good solubility in the above cellulose ester is referred to as a good solvent, and an organic solvent having a main effect on dissolution is referred to as a main (organic) solvent or a main (organic) solvent. .

For the dope, in addition to the above organic solvent, 1 to 4
It is preferable to contain 0% by mass of an alcohol having 1 to 4 carbon atoms. These are gelling that, after casting the dope on the metal support, the solvent begins to evaporate and the alcohol content increases, causing the web to gel, making the web tougher and easier to peel from the metal support. It is also used as a solvent, and when these ratios are small, it also has a role of promoting dissolution of the cellulose ester of the non-chlorine organic solvent.

As the alcohol having 1 to 4 carbon atoms,
Methanol, ethanol, n-propanol, iso-
Propanol, n-butanol, sec-butanol,
Mention may be made of tert-butanol. Of these, ethanol is preferable because it is excellent in stability of the dope, has a relatively low boiling point, has good drying property, and has no toxicity. These organic solvents alone have no solubility in cellulose ester and are called poor solvents.

In the present invention, the cellulose ester film preferably contains a plasticizer, an ultraviolet absorber, an antioxidant, fine particles (matting agent), a retardation adjusting agent and the like.

The plasticizer is not particularly limited, but it is a phosphoric acid ester plasticizer, a phthalic acid ester plasticizer, a trimellitic acid ester plasticizer, a pyromellitic acid plasticizer, a glycolate plasticizer, a quenching agent. Acid ester plasticizers, polyester plasticizers and the like can be preferably used.

In the phosphate ester system, triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate,
Diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc., in the phthalate ester system, diethyl phthalate, dimethoxyethyl phthalate, dimethyl phthalate, dioctyl phthalate,
Dibutyl phthalate, di-2-ethylhexyl phthalate, dicyclohexyl phthalate, butylbenzyl phthalate, etc. as trimellitic acid plasticizers, such as tributyl trimellitate, triphenyl trimellitate, triethyl trimellitate, pyromellitic acid ester plasticizers As, tetrabutylpyromellitate, tetraphenylpyromellitate, tetraethylpyromellitate, etc., in glycolic acid ester series, triacetin, tributyrin, ethylphthalylethylglycolate, methylphthalylethylglycolate, butylphthalylbutylglycolate. As citric acid ester plasticizers, triethyl citrate, tri-n-butyl citrate, acetyl triethyl citrate, acetyl tri-n-butyl citrate, acetyl citrate. -n-(2-ethylhexyl) citrate, it can be preferably used dicyclohexyl phthalate. Examples of other carboxylic acid esters include:
It includes butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. As a polyester plasticizer, an aliphatic dibasic acid,
A copolymer of dibasic acid such as alicyclic dibasic acid and aromatic dibasic acid and glycol can be used. The aliphatic dibasic acid is not particularly limited, but adipic acid, sebacic acid, phthalic acid, terephthalic acid, 1,4-cyclohexyldicarboxylic acid and the like can be used. As glycol, ethylene glycol, diethylene glycol,
1,3-propylene glycol, 1,2-propylene glycol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol and the like can be used. These dibasic acids and glycols may be used alone or in combination of two or more. The amount of these plasticizers used depends on the film performance,
1 to 20 relative to cellulose ester in terms of processability
It is preferably mass%.

As the ultraviolet absorber, those having excellent absorption of ultraviolet rays having a wavelength of 370 nm or less and little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display property. Specific examples of the ultraviolet absorber preferably used include, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex salt compounds, but are not limited thereto. Not done. In addition, JP-A-6-1484
The polymer ultraviolet absorber described in JP-A-30 is also preferably used.

Specific examples of the ultraviolet absorber useful in the present invention include 2- (2'-hydroxy-5'-methyl-phenyl) benzotriazole and 2- (2'-hydroxy-).
3 ', 5'-di-tert-butyl-phenyl) benzotriazole, 2- (2'-hydroxy-3'-ter
t-Butyl-5'-methyl-phenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-te
rt-Butyl-phenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 '-(3 ", 4",
5 ", 6" -tetrahydrophthalimidomethyl) -5 '
-Methyl-phenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol), 2- (2 '-Hydroxy-3'-tert
-Butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2H-benzotriazole-2-
Yl) -6- (linear and side chain dodecyl) -4-methyl-
Phenol << TINUVIN 171 >>, 2
-Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazole-2-
Iyl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5-
(5-chloro-2H-benzotriazol-2-yl)
Phenyl] propionate mixture << Tinuvin (TIN
UVIN) 109 >>, 2- (2H-benzotriazol-2yl) -4,6-bis (1-methyl-1-phenylethyl) phenol << Tinuvin 234 >>, and the like. Not limited. All of the above-mentioned tinuvins such as tinuvin 109, tinuvin 171, and tinuvin 326 are commercial products manufactured by Ciba Specialty Chemicals and can be preferably used.

Specific examples of the benzophenone compound include:
2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, bis (2-methoxy-4-hydroxy-5-benzoylphenylmethane), etc. Examples include, but are not limited to:

Further, the ultraviolet absorber which can be used in the cellulose ester film of the present invention is less contaminated in the plasma treatment step and is excellent in the coating property of various coating layers. Therefore, it is disclosed in Japanese Patent Application No. 11-295209. It is preferable to include an ultraviolet absorber having a distribution coefficient of 9.2 or more, and it is particularly preferable to use an ultraviolet absorber having a distribution coefficient of 10.1 or more.

Further, the high molecular weight ultraviolet absorbers (or ultraviolet absorbing polymers) described in JP-A-6-148430 and Japanese Patent Application No. 2000-156039 can be preferably used. General formula (1) or general formula (2) of JP-A-6-148430, or Japanese Patent Application No. 2000
The polymeric ultraviolet absorbers represented by the general formulas (3), (6) and (7) of -156039 are particularly preferably used.

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-4)
-Hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-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-
t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-
Butyl-4-hydroxy-hydrocinnamamide), 1,
3,5-Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, Tris- (3,5-di-t-butyl-4-hydroxybenzyl)- Isocyanurate and the like can be mentioned. In particular, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3 -(3-t-butyl-
5-Methyl-4-hydroxyphenyl) propionate] is preferred. In addition, for example, N, N′-bis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
A hydrazine-based metal deactivator such as propionyl] hydrazine and a phosphorus-based processing stabilizer such as tris (2,4-di-t-butylphenyl) phosphite may be used in combination. The addition amount of these compounds is preferably 1 ppm to 1.0% by mass ratio with respect to the cellulose ester, and 10 to 10%.
00 ppm is more preferable.

This antioxidant is also called a deterioration inhibitor. When the liquid crystal image display device or the like is placed in a high humidity and high temperature state, the cellulose ester film may be deteriorated. The antioxidant, for example, has a role of delaying or preventing the decomposition of the cellulose ester film due to halogen of the residual solvent amount in the cellulose ester film or phosphoric acid of the phosphoric acid-based plasticizer, and the like. It is preferably contained in the film. Examples of the fine particles added to the cellulose ester film include inorganic compounds such as silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, and hydrated silica. Calcium acid,
Mention may be made of aluminum silicate, magnesium silicate and calcium phosphate. Among them, those containing silicon are preferable because they have a low turbidity and can reduce the haze of the film, and silicon dioxide is particularly preferable. Although fine particles such as silicon dioxide are often surface-treated with an organic substance, such particles are preferable because they can reduce the haze of the film. Preferred organic substances for the surface treatment include halosilanes, alkoxysilanes, silazanes, siloxanes and the like. The silicon dioxide fine particles can be obtained, for example, by burning a mixture of vaporized silicon tetrachloride and hydrogen at 1000 to 1200 ° C. in the air. The particles of silicon dioxide are
Primary average particle diameter is 20 nm or less, apparent specific gravity is 70 g /
It is preferably L or more. The average diameter of the primary particles is 5
The thickness is more preferably 16 nm, further preferably 5 to 12 nm. The smaller the average diameter of the primary particles, the lower the haze, which is preferable. The apparent specific gravity is more preferably 90 to 200 g / L or more, and further preferably 100 to 200 g / L or more. The larger the apparent specific gravity is, the higher the concentration of the fine particle dispersion liquid can be made, and the haze and the aggregate are not generated, which is preferable. In the present invention, liter is represented by L. The amount of the fine particles added is preferably 0.01 to 1.0 g, more preferably 0.03 to 0.3 g, and 0.08 to 1 g per 1 m ^{2 of} the cellulose ester film.
0.16 g is more preferred. As a result, convex portions of 0.1 to 1 μm are preferably formed on the surface of the cellulose ester film.

Preferred silicon dioxide fine particles include, for example, Aerosil R972 manufactured by Nippon Aerosil Co., Ltd.,
R972V, R974, R812, 200, 200V,
300, R202, OX50, and TT600 (all manufactured by Nippon Aerosil Co., Ltd.) are commercially available. Aerosil 200V, R972, R9
72V, R974, R202 and R812 can be preferably used. As fine particles of zirconium oxide,
For example, they are commercially available under the trade names of Aerosil R976 and R811 (all manufactured by Nippon Aerosil Co., Ltd.), and any of them can be used. Among these Aerosil 200
V, Aerosil R972V, and Aerosil TT600 are particularly preferable because they have a large effect of reducing the turbidity and the coefficient of friction of the cellulose ester film of the present invention.

Examples of polymer fine particles include silicone resin, fluorine resin and acrylic resin. Of these, silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 14
5, 3120 and 240 (Toshiba Silicone Co., Ltd.)
Made).

In the measurement of the primary average particle diameter of the fine particles, the particles were observed with a transmission electron microscope (magnification: 500,000 to 2,000,000 times), 100 particles were observed, and the average value was used to determine the primary average. It can be a particle size. In addition, the apparent specific gravity described above can be calculated by the following formula, by taking a certain amount of silicon dioxide fine particles in a graduated cylinder and measuring the weight at this time. Apparent specific gravity (g / L) = mass of silicon dioxide (g) / volume of silicon dioxide (L)

The cellulose ester film is preferably made by solution casting film formation. In particular, a solution containing a cellulose ester is cast on a support, dried after peeling, and stretched 1.00 to 2.0 times in the width direction when the residual solvent amount is 3 to 40% by mass, It is preferably a cellulose ester film obtained by further drying.

The method for forming the cellulose ester film according to the present invention will be described below. The cellulose ester film can be produced by a solution casting film forming method.

Dissolution step: a step of dissolving the cellulose ester, polymer and additives in an organic solvent mainly composed of a good solvent for cellulose ester (flakes) while stirring to form a dope, or cellulose In this step, a polymer solution or an additive solution is mixed with an ester solution to form a dope. The dissolution of the cellulose ester is carried out under normal pressure, below the boiling point of the main solvent, under pressure above the boiling point of the main solvent, and disclosed in JP-A-9-
Various melting methods, such as the method of cooling and melting as described in JP-A-95544, JP-A-9-95557 or JP-A-9-95538, and the method of performing at high pressure as described in JP-A-11-21379. Although a method can be used, a method in which the pressure is higher than the boiling point of the main solvent is preferably used. The concentration of cellulose ester in the dope is 10 to 3
5 mass% is preferable. An additive is added to the dope during or after the dissolution to dissolve and disperse it, and the dope is filtered through a filter medium, defoamed, and sent to the next step by a liquid sending pump.

Casting step: An endless metal belt, such as a stainless steel belt, or a rotating metal drum, which feeds the dope to a pressure die through a liquid feed pump (for example, a pressure type fixed gear pump) and transfers it infinitely. This is a step of casting the dope from the pressure die slit at the casting position on the support. It is preferable to use a pressure die that can adjust the slit shape of the die of the die and can easily make the film thickness uniform. The pressure die includes a coat hanger die and a T die, and any of them is preferably used. The surface of the metal support is a mirror surface. In order to increase the film formation speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided to form multiple layers.
Alternatively, it is preferable to obtain a cellulose ester film having a laminated structure by a co-casting method in which a plurality of dopes are simultaneously cast.

Solvent Evaporation Step: A web (the dope film after casting the dope on the metal support is referred to as a web) is heated on the metal support so that the web can be peeled from the metal support. Up to the step of evaporating the solvent. To evaporate the solvent, there are a method of blowing air from the web side and / or a method of transferring heat from the back surface of the metal support by a liquid, a method of transferring heat from the front and back sides by radiant heat, and the like. Is preferable because of good drying efficiency. A method of combining them is also preferable. In the case of rear surface liquid heat transfer, it is preferable to heat at a temperature not higher than the boiling point of the main solvent of the organic solvent used for the dope or the organic solvent having the lowest boiling point.

Peeling step: This is a step of peeling the web having the solvent evaporated on the metal support at the peeling position. The peeled web is sent to the next step. In addition, if the residual solvent amount (the following formula) of the web at the time of peeling is too large, peeling is difficult, or conversely, if the web is peeled off after being sufficiently dried on the metal support, a part of the web It peels off.

Here, there is a gel casting method (gel casting) as a method of increasing the film forming speed (the film forming speed can be increased by peeling while the residual solvent amount is as large as possible). For example, there is a method in which a poor solvent for cellulose ester is added to the dope and gelling is performed after casting the dope, and a method in which the temperature of the metal support is lowered to cause gelation. By gelling on the metal support to increase the strength of the film at the time of peeling, the peeling can be accelerated and the film forming speed can be increased. Drying of the web on the metal support is 5 to 150% by mass depending on the strength of the condition and the length of the metal support.
However, if the web is too soft, the flatness is impaired at the time of peeling, and cracks and vertical streaks due to peeling tension tend to occur. The amount of residual solvent at the time of peeling is determined by the trade-off between quality and quality. In the present invention, the temperature at the peeling position on the metal support is preferably 10 to 40 ° C, more preferably 15 to 30 ° C. In addition, the residual solvent amount of the web at the peeling position is 10 to 1
It is preferably 20% by mass. The amount of residual solvent can be represented by the following formula. Residual solvent amount (mass%) = {(M−N) / N} × 100 Here, M is the mass of the web at an arbitrary time point, and N is the mass of the mass M when dried at 110 ° C. for 3 hours. Is.

Drying and Stretching Process: After peeling, using a drying device that alternately conveys the web through a plurality of rolls arranged in the drying device, and / or a tenter device that clips both ends of the web with a clip and conveys the web. , Dry the web. In the present invention, it is preferable to use a tenter device as a method of stretching 1.00 to 2.0 times in the width direction between the clips. More preferably, it is biaxially stretched in the longitudinal and transverse directions. The draw ratio is set according to the desired optical characteristics (Ro, Rt). or,
When producing a retardation film, it may be uniaxially stretched in the longitudinal direction. As a drying means, hot air is generally blown on both sides of the web, but a microwave may be applied instead of the air to heat the web. Drying too rapidly tends to impair the flatness of the finished film. Throughout, the drying temperature is usually in the range of 40 to 250 ° C.
The drying temperature, the amount of drying air and the drying time vary depending on the solvent used, and the drying conditions may be appropriately selected depending on the type and combination of the solvents used.

Further, the transmittance of the optical film is preferably 90% or more, more preferably 92% or more, and particularly preferably 94% or more. Further, the haze of the cellulose ester film is preferably 0 to 1%, and particularly preferably 0 to 0.1%. When the antiglare layer is provided on the optical film, the haze value of the entire optical film is preferably 3 to 30%.

Further, in the optical film of the present invention,
The water vapor transmission rate is preferably 250 g / m ² · 24 hours or less, more preferably 0 to 220 g / m ² · 24 hours, and particularly preferably 1 to 200 g / m ² · 24 hours. If the moisture permeability is too low, the evaporation rate of water contained in an adhesive such as an aqueous polyvinyl alcohol solution at the time of bonding with a polarizer will be slow, which is not preferable, but the cellulose ester film itself has moisture permeability and water absorbency. Therefore, there is no big problem in the present invention.

Further, as the optical film of the present invention, those having a retardation value Rt in the thickness direction of 0 to 300 nm and a retardation value Ro in the in-plane direction of 0 to 1000 nm are particularly preferably used. Further, it is preferable that knurling is provided at the end of the optical film of the present invention. In particular, the height of the knurling is preferably 25% or less of the film thickness of the cellulose ester film, and the stability of the rolled film during storage is improved.

[0116]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. In addition, the "part" shown below means the "mass part."

[Example 1] <Preparation of substrate film> A cellulose ester film as a substrate was prepared according to the method described below.

(Preparation of Dope) The following materials were placed in a closed container, heated, stirred and completely dissolved and filtered to prepare dopes 1 to 7. The silicon dioxide fine particles (Aerosil R972V) were added after being dispersed in ethanol. The average particle size of the secondary particles was 0.44 μm.

[0119]   Dope 1   Cellulose triacetate (acetyl substitution degree 2.88) 100 parts   Triphenyl phosphate 8 parts   Ethylphthalyl ethyl glycolate 2 parts   Chinubin 171 (manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.4 parts   Chinubin 109 (manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.4 parts   TINUVIN 326 (manufactured by Ciba Specialty Chemicals Co., Ltd.) 0.3 part   Methylene chloride 415 parts   30 parts of ethanol   Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) 0.13 parts

[0120]   Dope 2   Cellulose triacetate (acetyl substitution degree 2.68) 100 parts   Ethylphthalyl ethyl glycolate 4 parts   Chinubin 171 0.4 part   Tinuvin 109 0.4 part   Tinuvin 326 0.3 parts   Methylene chloride 415 parts   30 parts of ethanol   Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) 0.13 parts

[0121]   Dope 3   Cellulose triacetate (acetyl substitution degree 2.88) 100 parts   Dicyclohexyl phthalate 10 parts   Chinubin 171 0.4 part   Tinuvin 109 0.4 part   Tinuvin 326 0.3 parts   Methylene chloride 400 parts   22 parts of ethanol

[0122]   Dope 4   Cellulose triacetate (acetyl substitution degree 2.88) 100 parts   Methylene chloride 415 parts   30 parts of ethanol   Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) 0.15 parts

[0123]   Dope 5   Cellulose acetate propionate   (Acetyl substitution degree 1.9, propionyl substitution degree 0.7) 100 parts   Triphenyl phosphate 8 parts   Ethylphthalyl ethyl glycolate 2 parts   Chinubin 171 0.4 part   Tinuvin 109 0.4 part   Tinuvin 326 0.3 parts   Methylene chloride 380 parts   50 parts of ethanol

[0124]   Dope 6   Cellulose acetate propionate   (Acetyl substitution degree 1.9, propionyl substitution degree 0.7) 100 parts   Methylene chloride 380 parts   50 parts of ethanol   Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) 0.16 parts

[0125]   Dope 7   Cellulose acetate propionate   (Acetyl substitution degree 2.0, propionyl substitution degree 0.8) 100 parts   Triphenyl phosphate 8 parts   Ethylphthalyl ethyl glycolate 2 parts   Chinubin 171 0.4 part   Tinuvin 109 0.4 part   Tinuvin 326 0.3 parts   250 parts ethyl acetate   80 parts of ethanol   Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) 0.12 part

(Production of Cellulose Ester Film) Using the obtained dopes 1 to 7, cellulose ester films 1 to 15 shown in Table 1 below were produced as follows. First, the dope was filtered and then uniformly cast on a stainless band support at 33 ° C. at a dope temperature of 34 ° C. using a belt casting device. After being dried on the support for 60 seconds, the web was peeled off from the stainless band support. Here, the cellulose ester film 12-
No. 15 has a laminated structure by the co-casting method. That is, two types of dope were combined in one die and cast to form a three-layer structure.

After peeling from the stainless band support,
After roll-conveying in an atmosphere of 80 ° C and drying while applying conveyance tension in the longitudinal direction, the amount of residual solvent is 10% in a tenter.
At that time, the film was stretched in the width direction in an atmosphere of 80 ° C (note that
The cellulose ester film 15 was stretched in the longitudinal direction without stretching in the width direction using a tenter). After that, the width retention is released, the drying is completed in the drying zone at 120 ° C. while the roll is further conveyed, the both ends of the film are subjected to knurling with a width of 10 mm and a predetermined height, and the film is wound into a roll, and the cellulose ester is used. Films 1 to 15 were produced. Table 1 shows the dry film thickness of the layer formed from each dope.

[Table 1]

Further, the obtained cellulose ester films 1 to 15 were continuously subjected to atmospheric pressure plasma treatment to form a silicon oxide layer on one side or both sides, and the optical films 1 to 30 shown in Table 2 below were obtained. Obtained. Film width is 130
The winding length was 0 mm and the winding length was 2500 m.

Here, in the atmospheric pressure plasma treatment,
A reaction gas was brought into a plasma state by discharging between opposing electrodes under the following discharge conditions, and the film was exposed to the reaction gas in the plasma state to form a silicon oxide layer on the surface of the film. Discharge conditions Power frequency 800 kHz Electric power 10 W / cm ² atmosphere Atmospheric pressure +0.1 kPa Reactive gas Inert gas: Argon 99.0 vol% Reactive gas 1: Oxygen gas 0.7 vol% Reactive gas 2: Tetraethoxysilane vapor (Argon gas Bubbling in) 0.3% by volume

<Measurement of Carbon Content> The carbon content of each of the optical films 1 to 15 prepared was measured by XPS (X-ray Photoelect).
ron Spectroscopy) was measured using a surface analyzer. X
The PS surface analyzer is not particularly limited, and any model can be used, but in this embodiment, the VG is used.
ESCALAB-200R made by Scientific Fix Co.
Was used. Mg is used for the X-ray anode and the output is 600W
(Acceleration voltage 15 kV, emission current 40 mA). The energy resolution was set to be 1.5 to 1.7 eV when defined by the full width at half maximum of a clean Ag3d5 / 2 peak.

Before carrying out the measurement, it is necessary to etch away the surface layer corresponding to 10 to 20% of the film thickness in order to eliminate the influence of contamination. For removing the surface layer, it is preferable to use an ion gun capable of utilizing rare gas ions, and as the ion species, He, Ne, A
r, Xe, Kr, etc. can be used. In this measurement,
The surface layer was removed using Ar ion etching.

In the XPS surface analysis, the binding energy range from 0 eV to 1100 eV was measured at a data acquisition interval of 1.0 eV to determine which atom was detected.

Next, with respect to all the detected atoms except for the etching ion species, the data acquisition interval is set to 0.
At 2 eV, a narrow scan was performed on the photoelectron peak giving the maximum intensity, and the spectrum of each atom was measured. The obtained spectrum is VAMAS-SCA-J in order to prevent the difference in the content calculation result due to the difference of the measuring device or the computer.
APAN-made COMMON DATA PROCESS
ING SYSTEM (Ver. 2.3 or later is preferable. Here, Ver. 2.3 was used), and then the same software was used to process the value of carbon content to atomic concentration (atomic concentration). Sought as.

Before performing the quantitative treatment, the Count Scale was calibrated for each atom, and the 5-point smoothing treatment was performed. In the quantitative treatment, the peak area intensity (cps * eV) from which the background was removed was used. The method by Shirley was used for the background treatment. Shirle
For the y method, see D.Y. A. Shirley, Phys.
Rev. , B5, 4709 (1972) can be referred to. As a result of the measurement, the carbon content of the formed silicon oxide layer was 0.5%.

<High-Temperature and High-Humidity Rolling Shape Change> Each of the optical films 1 to 15 wound in a roll shape for 2000 m is covered with a vinyl sheet for preventing dust adhesion, and this is wrapped at 35 ° C. and 80% RH (relative humidity). Under the environment of 2
After leaving it for a week, the change of the surface shape in the wound state was visually confirmed. As a comparison, cellulose ester films 1 to 15 wound in a roll shape without forming these layers.
The shape change was also confirmed (Comparative Examples 31 to 45).

The results of confirmation of changes in the winding shape are shown below. A: No change is observed. ◯: Weak wrinkles are recognized on the surface of the roll. Δ: The shape is significantly deteriorated near the roll surface, and wrinkles and dents are observed on the entire surface. X: The surface of the roll is significantly deteriorated in shape, wrinkles and dents are observed on the entire surface, and the shape of the roll is also deteriorated.

[Table 2] Here, the surface that was in contact with the stainless band support during casting was designated as surface B, and the opposite side was designated as surface A.

Example 2 According to the following method, a clear hard coat layer was provided on each of the silicon oxide layers of the optical films 1 to 15 produced in Example 1 to form an optical film 4.
6-60 were produced.

<Coating of Clear Hard Coat Layer (CHC Layer)> The following coating composition (1) was gravure coated and then dried in a drying section set at 80 ° C., then 118 mJ
/ Cm ² was irradiated with ultraviolet rays to form a clear hard coat layer having a dry film thickness of 3 μm and a center line average roughness (Ra) of 10 nm. Here, the above-mentioned center line average roughness (Ra) is JIS
It is a value defined by B0601.

[0139]   Coating composition (1) (clear hard coat layer (CHC layer) coating composition)   Dipentaerythritol hexaacrylate monomer 60 parts   Dipentaerythritol hexaacrylate dimer 20 parts   Dipentaerythritol hexaacrylate trimer 20 parts or more   Dimethoxybenzophenone photoinitiator 4 parts   50 parts of ethyl acetate   Methyl ethyl ketone 50 parts   Isopropyl alcohol 50 parts

Further, according to the following method, antiglare layers were respectively provided on the silicon oxide layers of the optical films 1 to 15 to produce optical films 61 to 75. In all cases, coating streaks and brushing did not occur, and the coating properties were good.

<Coating of Antiglare Layer> After stirring the following materials with a high-speed stirrer (TK homomixer, manufactured by Tokushu Kika Kogyo Co., Ltd.), a collision type disperser (Manton Gorin, manufactured by Gorin Co., Ltd.) Dispersed. Ethyl acetate 50 parts Methyl ethyl ketone 50 parts Isopropyl alcohol 50 parts Aerosil R972V (primary particle average particle size 16 nm) (manufactured by Nippon Aerosil Co., Ltd.)) 5 parts

After dispersion, the following components were added to prepare coating composition (2) (antiglare layer (AG layer) coating composition). Dipentaerythritol hexaacrylate monomer 60 parts Dipentaerythritol hexaacrylate dimer 20 parts Dipentaerythritol hexaacrylate trimer The above components 20 parts Dimethoxybenzophenone photoreaction initiator 4 parts Coating composition obtained (2) Is gravure-coated and then dried in a drying section set at 80 ° C., then 118 mJ /
Ultraviolet irradiation was performed at a cm ² to provide an antiglare layer (center line average roughness (Ra) of 0.25 μm) having a dry film thickness of 4 μm.

With respect to the produced optical films 46 to 75, the change in the winding shape under high temperature and high humidity was evaluated in the same manner as in Example 1. No change in the winding state due to the high temperature and high humidity treatment was observed in any of the optical films 46 to 75.

[Example 3] Optical films 4, 5, 14, 15, 19, 20, 29, 30, 3 produced in Example 1
4, 35, 44 and 45 were left at 23 ° C. and 55% RH for 24 hours, and then the automatic birefringence meter KOBRA-21
Using ADH (manufactured by Oji Scientific Instruments), 23 ° C, 5
Three-dimensional refractive index measurement was performed at a wavelength of 590 nm in an environment of 5% RH, and a retardation value Rt in the film thickness direction and a retardation value Ro in the in-plane direction were obtained. Further, these samples were allowed to stand at 35 ° C. and 80% RH for 72 hours, and then the three-dimensional refractive index was similarly measured to obtain retardation values Rt and Ro, and variations before and after the high temperature and high humidity treatment. The results are shown in Table 3.

[Table 3] In Comparative Examples 34, 35, 44 and 45, the Rt value, R
While the o values were all reduced, the optical films 4, 5, 14, and 15 showed almost no fluctuations in the Rt value and the Ro value. In addition, the optical films 19 and 2
Regarding 0, 29 and 30, no change in Rt value and Ro value was observed.

Example 4 A silicon oxide layer having a thickness of 0.3 μm was formed by plasma treatment on the A side of the cellulose ester film 12 produced in Example 1 under the same conditions as in Example 1, and the same procedure was performed. A silicon oxide layer having a film thickness of 0.01 μm was provided on the surfaces B and B to obtain an optical film 76. Optical film 7
A clear hard coat layer was provided on the silicon oxide layer provided on the B side of 6 by the method described in Example 2 to obtain an optical film 77. Further, an antiglare layer was provided on the silicon oxide layer provided on the B surface side of the optical film 76 by the method described in Example 2 to obtain an optical film 78.

A silicon oxide film having a thickness of 0.05 μm was formed by plasma treatment in the same manner as in Example 1 except that the discharge conditions were changed as follows on the A side of the cellulose ester film 1 produced in Example 1. A layer having a thickness of 0.5 is formed on the B side in the same manner except that the discharge conditions are changed as described below.
An optical film 79 was obtained by providing a silicon oxide layer having a thickness of μm.

Discharge conditions (Side A side) Frequency 200 kHz Power 2 W / cm ² Reaction gas Argon 98.7% Hydrogen 1% Tetraethoxysilane 0.25% (Bubbling with argon gas) Dimethyldiethoxysilane 0.05% (Argon Bubbling with gas) Here, the carbon content of the silicon oxide film provided on the A surface side was 6%.

Discharge conditions (B side) Frequency 2 MHz Power 8 W / cm ² Reactive gas Argon 98.7% Hydrogen 1% Tetraethoxysilane 0.25% (Bubbling with argon gas) Dimethyldiethoxysilane 0.05% (Argon Bubbling with gas) Here, the carbon content of the silicon oxide film provided on the B surface side was 2%.

On the silicon oxide layer provided on the B side of the optical film 79, a clear hard coat layer was provided by the method described in Example 2 to obtain an optical film 80. Further, an antiglare layer was provided on the silicon oxide layer provided on the B surface side of the optical film 79 by the method described in Example 2 to obtain an optical film 81.

The optical films 76 to 81 were wound into rolls, and the change in the winding shape under high temperature and high humidity was evaluated in the same manner as in Example 1. No deterioration of the winding shape was observed even when stored under high temperature and high humidity conditions.

The long cellulose ester film 1 produced in Example 1 was immersed in a 2 mol / L sodium hydroxide solution at 50 ° C. for 80 seconds, then washed with water and dried,
Further, in the same manner as in Example 1, a silicon oxide layer having a film thickness of 0.2 μm was formed on the B side by plasma treatment, and this was used as an optical film 82. Further, the cellulose ester film 1 was replaced with the long cellulose ester film 12 produced in Example 1 in the same manner, and the film thickness on the side B was 0.3.
A μm silicon oxide layer was formed by plasma treatment, and this was used as an optical film 83.

The long optical films 76 to 81 are set to 2 mo.
It was dipped in a 1 / L sodium hydroxide solution at 55 ° C. for 90 seconds, washed with water and dried to obtain saponified optical films 76 to 81. Long optical film 1, 12
In a 2 mol / L sodium hydroxide solution at 45 ° C.
It was dipped for 0 seconds, washed with water and dried to obtain saponified optical films 1 and 12.

A clear hard coat layer was provided on the cellulose ester films 1 and 12 produced in Example 1 by the method described in Example 2, and the long film thus obtained was
9 mol at 2 ℃ / L of sodium hydroxide solution at 55 ℃
It was dipped for 0 second, washed with water and dried to perform saponification treatment. These were used for producing the polarizing plates 21 and 23 described later, respectively. While the clear hard coat layer of the polarizing plate 21 had a pencil hardness of 2H, the polarizing plates 1 to 19 had a pencil hardness of 3H.
It was confirmed that it was excellent. Pencil hardness is JI
It was measured according to SK-5400.

Using the saponified optical film as a protective film for a polarizing plate, polarizing plates 1 to 23 shown in Table 4 below were produced according to the following method. <Production of Polarizing Film> A long polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution containing 0.08 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then 6 g of potassium iodide and 7.5 g of boric acid,
It was immersed in a 68 ° C. aqueous solution consisting of 100 g of water.
Then, this was washed with water and dried to obtain a long polarizing film.

<Preparation of Polarizing Plate> Next, the following steps 1 to 5
According to the above, the obtained polarizing film and the optical film were attached to each other to prepare a polarizing plate. Step 1: The optical film or cellulose ester film of the present invention was saponified by the above method as a polarizing plate protective film. Step 2: The long polarizing film described above was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds. Step 3: The adhesive excessively attached to the polarizing film in Step 2 was lightly removed, and the combination of Table 4 was sandwiched between the saponification treated surfaces of the polarizing plate protective film, and laminated. Step 4: 20-30 N / with two rotating rollers
The polarizing film and the optical film were bonded together at a pressure of cm2 and a speed of about 2 m / min. At this time, care was taken to prevent bubbles from entering. Step 5: The sample prepared in Step 4 was dried in a dryer at 80 ° C. to prepare a polarizing plate.

<Durability Test> Polarizing plates 1 to 23 were heated to 65 ° C.
It was left for 12 days under a high temperature and high humidity condition of 95% RH, and the amount of change in polarization degree before and after that was determined. Here, the transmittance when the two polarizing plates which are the measurement samples are stacked so that the orientation directions of the respective polarizers are the same is defined as the parallel transmittance Tp, and the two polarizing plates are respectively The transmittance in the case where the polarizers are stacked so that the orientations thereof are orthogonal to each other is defined as an orthogonal transmittance Tc,
The polarization degree P was calculated by the following formula (3).

[Equation 1]

The results of the durability test are shown below. ◎ Polarization degree change 0% or less, and -0.3
% Greater than the degree of polarization change −0.3% or less, and −0.5
% Polarization change amount −0.5% or less, and −1.0
% Greater than the degree of polarization change −1.0% or less, and −2.0
%% xx Polarization degree change -2.0% or less

[Table 4] It has been confirmed that the polarizing plates 1 to 19 using the optical films 75 to 83 of the present invention as the polarizing plate protective film have excellent fluctuations in the degree of polarization even when subjected to high temperature and high humidity treatment and have excellent durability. It was also confirmed that the optical film of the present invention can be subjected to saponification treatment, which is particularly preferable as a polarizing plate protective film.

Example 5 Commercially available liquid crystal display panel (NE
Color liquid crystal display made by C MultiSync
The polarizing plate on the outermost surface of LCD1525J (model name: LA-1529HM) was carefully peeled off, and the polarizing plates 1 to 23 after the durability test in which the polarization directions were matched were attached to each. As a result, in the polarizing plates 1 to 19 which are the polarizing plates of the present invention, the contrast was high and the high display performance was maintained. On the other hand, it was confirmed that the contrasts of the comparative polarizing plates 20 to 23 were clearly low.

[0159]

According to the present invention, at least one of oxygen atom and nitrogen atom and a metal atom are formed on at least one surface of the cellulose ester film directly or through another layer. Since the metal compound layer is provided, it is possible to prevent the flatness and surface quality of the rolled cellulose ester film from being deteriorated.
Further, since the metal compound layer is provided, the storage stability of the rolled cellulose ester film can be significantly improved. Also, to prevent coating failures such as uneven coating and brushing,
The coating property on the film can be improved. Further, since the dense metal film is formed by providing the metal compound layer by the atmospheric pressure plasma treatment, moisture absorption by the cellulose ester film can be prevented.

[Brief description of drawings]

FIG. 1 is a view showing an example of a plasma discharge treatment apparatus used for forming a thin film of a metal compound layer of the present invention.

[Explanation of symbols]

1 Plasma discharge treatment device 2 rotating electrodes 3 Counter electrode F Base film G reaction gas 10.11 Voltage supply means

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02B 5/30 G02F 1/1335 510 4F205 G02F 1/1335 510 1/13363 1/13363 B29K 1:00 // B29K 1:00 B29L 7:00 B29L 7:00 C08L 1:10 C08L 1:10 G02B 1/10 Z F Term (reference) 2H049 BA02 BA25 BA27 BB33 BB43 BB51 BC03 BC14 BC22 2H091 FA08 FA11 FA50 FB03 FB08 FC07 GA16 LA30 2K009 BB28 CC01 CC03 CC42 DD04 EE00 4F006 AA02 AB76 BA00 BA02 CA05 DA01 EA03 4F100 AA01B AA01D AA17B AA17D AA20B AA20D AJ06C AK01A AK01E AK25 BA03 BA05 BA10A BA10E BA25B BA25C BA25D EH46C EJ61B EJ61D EJ612 JB13A JB13E JB14A JB14E JN06 4F205 AA01 AG01 AG03 AH73 GA07 GB02 GW21 GW34

Claims (25)

[Claims] 1. An optical film including a cellulose ester film, comprising at least one of an oxygen atom and a nitrogen atom,
With a metal atom, a metal compound layer comprising containing at least one surface of the cellulose ester film,
An optical film, which is provided directly or through another layer. 2. A cellulose ester film having a thickness of 1
It is 0-500 micrometers, The optical film of Claim 1 characterized by the above-mentioned. 3. The thickness of the metal compound layer is 0.005 to 1 μm.
The optical film according to claim 1 or 2, wherein m is m. 4. The metal atom contained in the metal compound layer is a silicon atom, and the ratio of the number of oxygen atoms and nitrogen atoms contained in the metal compound layer to the number of metal atoms is x and y, respectively. In this case, x is 0 or more and 2 or less, and y is 0 or more and 4/3.
It is the following, The optical film in any one of Claims 1-3. 5. The optical film according to claim 1, wherein the metal compound layer is provided on both surfaces of the cellulose ester film directly or via another layer. 6. The film thickness of the metal compound layer provided on one surface of the cellulose ester film is larger than the film thickness of the metal compound layer provided on the other surface of the cellulose ester film. 5. The optical film according to item 5. 7. The optical film according to claim 1, wherein the metal compound layer contains carbon atoms. 8. The content of carbon atoms in the metal compound layer is
It is 0.1-10 mass%, The optical film of Claim 7 characterized by the above-mentioned. 9. On at least one metal compound layer,
The optical film according to any one of claims 1 to 8, wherein a resin layer is provided directly or via another layer. 10. The optical film according to claim 9, wherein the resin layer is an actinic ray curable resin layer or a thermosetting resin layer. 11. The optical film according to claim 1, wherein the thickness of the metal compound layer is greater than 0.1 μm and 0.8 μm or less. 12. A cellulose ester film having a thickness of 10 to 60 μm.
The optical film according to any one of 1. 13. The optical film according to claim 1, wherein the cellulose ester film has a laminated structure formed by a co-casting method. 14. The optical film according to claim 1, wherein a knurling having a height of 25% or less of a film thickness of the cellulose ester film is provided at an end portion. 15. A polarizing plate protective film comprising the optical film according to any one of claims 1 to 14. 16. A retardation value (Rt value) in the film thickness direction defined by the following formula (1) is 70, which is constituted by using the optical film according to any one of claims 1 to 14.
Is 300 nm or the retardation value (Ro value) in the in-plane direction defined by the following formula (2) is 40 to 1000 n.
or a R0 value of 70 to 300 nm and a Ro value of 40 to 1000 nm. Rt value _{= ((n x + n y} ) / 2-n z) × d ... (1) Ro value _{= (n x -n y) ×} d ... (2) (n x is a refractive index in the film plane is most Refractive index in the larger direction, n _y is the in-plane refractive index in the direction perpendicular to n _x ,
_nz represents the refractive index in the thickness direction of the film, and d represents the thickness (nm) of the film. ) 17. A polarizing plate comprising the polarizing plate protective film according to claim 15. 18. An actinic radiation curable resin layer, a metal compound layer having a film thickness of 0.01 to 1 μm from at least one surface,
The polarizing plate according to claim 17, which has a laminated structure in which a cellulose ester film, a polarizer, a cellulose ester film, and a metal compound layer having a film thickness of 0.01 to 1 µm are laminated in this order. 19. A solution containing a cellulose ester is cast on a support, peeled and dried to give a residual solvent amount of 3-4.
When it was 0% by mass, the film was stretched 1.00 to 2.0 times in the width direction and further dried, and a reaction gas containing a silicon compound was supplied to at least one surface of the cellulose ester film thus obtained. However, the method for producing an optical film, wherein a metal compound layer containing at least one of oxygen atoms and nitrogen atoms and silicon atoms is provided by atmospheric pressure plasma treatment. 20. Atmospheric pressure plasma treatment is performed at 100 kHz.
20. The method for producing an optical film according to claim 19, wherein the method is performed by supplying a power of 1 W / cm ² or more and discharging with a high-frequency voltage exceeding the above. 21. The method for producing an optical film according to claim 19, wherein an actinic radiation curable resin layer is provided on at least one metal compound layer directly or via another layer. 22. A method for producing a polarizing plate, which comprises subjecting the optical film produced by the method for producing an optical film according to any one of claims 19 to 21 to a saponification treatment and laminating it with a polarizer. 23. A solution containing a cellulose ester is cast on a support, peeled and dried to give a residual solvent amount of 3-4.
When it was 0% by mass, the film was stretched 1.00 to 2.0 times in the width direction and further dried, and both surfaces of the cellulose ester film thus obtained were saponified, and one surface saponified was left. And a metal compound layer containing at least one of an oxygen atom and a nitrogen atom and a silicon atom is provided on the other surface subjected to the saponification treatment by atmospheric pressure plasma treatment. Method for manufacturing plate protection film. 24. A method of manufacturing a polarizing plate, which comprises manufacturing a polarizing plate by laminating a polarizing plate protective film containing a cellulose ester film and a polarizer, wherein the polarizing plate protective film and the polarizer are Before or after bonding, a metal compound layer containing at least one of oxygen atoms and nitrogen atoms and a silicon atom is provided on the polarizing plate protective film by atmospheric pressure plasma treatment. A method of manufacturing a polarizing plate, comprising: 25. A display device comprising the optical film according to claim 1.