JP2003294945A - Optical film, method for manufacturing the same, and polarizing plate and display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film having significantly decreased cracks, improved curling, and little decrease in conductivity in a conductive film or an antireflection film having a metal oxide nitride layer deposited on a polyester film as an optical film to be used for various kinds of display devices. <P>SOLUTION: The optical film has a metal oxide nitride layer directly deposited or with another layer interposed on a substrate film having a polyester resin layer with 1% to 5% equilibrium moisture content which is produced by the reaction of at least an aromatic dicarboxylic acid and glycol. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

The present invention relates to a liquid crystal display,
The present invention relates to an optical film used in various display devices such as an organic EL display, an inorganic EL display and a plasma display, and particularly to an antireflection film or a conductive film.

[0002]

2. Description of the Related Art With the remarkable development of the information industry, display devices have been used in various places. In particular, the development of liquid crystal display devices has been remarkable, and they have come to be installed in various devices. On the other hand, demands for smaller size and lighter weight are increasing, and thinning requirements for members such as polarizing plates are also increasing. A polarizing plate is usually made by sandwiching a polarizer between two polarizing plate protective films, and a cellulose ester film such as triacetyl cellulose is preferably used as the polarizing plate protective film.

However, in order to make the polarizing plate thin,
If the triacetyl cellulose film (TAC film), which is a protective film, is made thin, the moisture permeability deteriorates,
There is a problem that dimensional stability is reduced, especially 40μ
It is difficult to impart sufficient durability to the polarizing plate because a thin film having a thickness of less than m causes a remarkable decrease in physical properties.

On the other hand, it is known that polyester can be used as a polarizing plate protective film. For example, it is known to use a polyethylene terephthalate film. The polyethylene terephthalate film has low moisture permeability and is excellent in dimensional stability as compared with a TAC film, but it is inferior in adhesiveness to a polarizer because saponification treatment cannot be performed. In addition, there is a problem that the drying property of the adhesive is extremely poor when it is attached to the polarizer. Further, conventionally, in a film in which a metal oxynitride layer is provided on a polyester film, there are problems that cracks and curls occur and that the conductivity of the metal oxynitride layer decreases.

[0005]

Therefore, the object of the present invention is to provide a liquid crystal display, an organic EL display, an inorganic EL display.
In a conductive film and an antireflection film in which a metal oxynitride layer is provided on a polyester film as an optical film used in various display devices such as displays and plasma displays, cracks are significantly reduced, curling is improved, and conductivity is improved. It is to provide a film with less deterioration.

[0006]

The above object of the present invention can be achieved by the following constitution.

1) Metal oxynitridation directly or through another layer on a base film having a polyester resin layer produced by a reaction of at least an aromatic dicarboxylic acid and glycol and having an equilibrium water content of 1 to 5%. An optical film comprising a physical layer.

2) The film thickness is 5 to 40 μm, and the dimensional stability is ±
It is 0.5% or less, The optical film as described in 1) above.

3) The optical film as described in 1) or 2) above, wherein the polyester resin has a group selected from sulfonic acids or salts thereof.

4) The optical film as described in 3) above, wherein the polyester resin has a sulfur element content of 0.15 to 2 mass%.

5) The polyester resin has an aromatic dicarboxylic acid having a group selected from 1 to 10 mol% of sulfonic acid and its salt with respect to the total aromatic dicarboxylic acid, or 1 to 10 mol% of sulfonic acid with respect to the total glycol, and The optical film as described in 3) or 4) above, which is produced using a glycol having a group selected from its salts.

6) The polyester resin is produced by using 1 to 10 mol% of aromatic dicarboxylic acid having a group selected from sulfonic acid and salts thereof, based on wholly aromatic dicarboxylic acid. Or the optical film as described in 4).

7) The polyester resin contains polyalkylene glycol in an amount of 0.
The optical film as described in any one of 1) to 6) above, which is produced using 1 to 10% by mass.

8) The above 1) to 1) wherein the main component of the polyester resin is polyethylene terephthalate
The optical film according to any one of 7).

9) The above-mentioned 7) or 8), wherein the metal oxynitride layer is provided directly or through another layer on a long film continuously formed by melt extrusion. Optical film.

10) Optics characterized in that a metal oxynitride layer is provided by atmospheric pressure plasma CVD directly or through another layer on a substrate having a polyester resin layer having an equilibrium water content of 1 to 5%. the film.

11) Atmospheric pressure plasma of a metal oxynitride layer directly or through another layer on a substrate film formed by stretching a film having a polyester resin having a group selected from sulfonic acid or a salt thereof. A method for producing an optical film, which is characterized by being formed by CVD.

12) A polarizing plate using the optical film as described in any one of 1) to 10) above.

13) A display device using the polarizing plate described in 12) above. Hereinafter, details of the present invention will be described.

The optical film of the present invention is a polyester film having a metal oxynitride layer provided on the surface thereof directly or through another layer. The metal oxynitride layer is a layer containing a metal oxide, a metal nitride, or a mixture thereof. Examples of metal nitrides include titanium nitride and silicon nitride.

As a result of intensive studies in order to solve the above problems found in conventional polyester films, the present inventors have found that an optical film having a polyester resin layer having an equilibrium water content of 1 to 5% is used. It has been found that the above problems can be solved by using them.

In the present invention, the polyester resin layer having an equilibrium water content of 1 to 5% may form a polyester film alone, or may be laminated with a polyester resin layer having an equilibrium water content of less than 1%. It may be laminated on a film made of another material, and the resin used for the support is not particularly limited.

The equilibrium water content is the amount of water contained in the sample in the equilibrium state, expressed as a percentage of the sample mass. As a specific method, a polyester film (or, when laminated on another film, the polyester resin layer film peeled off from the substrate) at 23 ° C. and a relative humidity of 20% is conditioned in a room. After leaving it for 4 hours or longer, it is immersed in distilled water at 23 ° C. for 24 hours, and then the sample is used at a temperature of 150 ° C. using a trace moisture meter (for example, CA-20 type manufactured by Mitsubishi Chemical Corporation).
It is a method of quantifying by the Karl Fischer method after drying and vaporizing water.

For polyester, a direct esterification method in which an aromatic dicarboxylic acid component is directly esterified with a glycol component, and first, a dialkyl ester is used as an aromatic dicarboxylic acid component, and a transesterification reaction is performed between the aromatic dicarboxylic acid component and the glycol component, It can be produced by a transesterification method in which this is polymerized by heating under reduced pressure to remove an excess glycol component. At this time, if necessary, a transesterification catalyst or a polymerization reaction catalyst is used, or a heat-resistant stabilizer or the like is used for production.

In the present invention, the raw material and its copolymerization component are used as the raw material and the copolymerization component thereof, even when the dialkyl ester of the dicarboxylic acid is first used or when the esterification method in which the dicarboxylic acid component and the glycol component are once subjected to the esterification reaction is used. When referred to, the amount is equivalent to an aromatic dicarboxylic acid or glycol.

In the above process, for example, a copolymerization component such as an aromatic dicarboxylic acid or a polyalkylene glycol having a group selected from sulfonic acid and its salt is added after the transesterification reaction, and polycondensation is carried out to obtain these compounds. A polyester resin containing a copolymer component is obtained.

Therefore, the equilibrium water content used in the present invention is 1
As the polyester resin forming the polyester resin layer of up to 5%, specifically, a polyester resin obtained by a reaction of at least an aromatic dicarboxylic acid and glycol, and selected from sulfonic acid or a salt thereof in the polyester resin structure A polyester resin having a group represented by

These sulfonic acid groups are mixed with a predetermined amount of an aromatic dicarboxylic acid or glycol having a group selected from sulfonic acid and salts thereof as a copolymerization component of dicarboxylic acid such as terephthalic acid or glycol such as ethylene glycol. It can be incorporated into a polyester resin by producing polyester.

The content of elemental sulfur contained in the polyester resin thus obtained is preferably 0.15 to 2% by mass.

If the content of these elemental sulfur exceeds 2%, the content of sulfonic acid groups may be too high, resulting in poor mechanical strength. If it is less than 0.15%, the number of sulfonic acid groups may be reduced. Does not exist in a sufficient ratio, and the effect of the present invention is not provided.

It is not necessary that all of the sulfur element in the polyester resin be derived from a group selected from a sulfonic acid group or a salt thereof, but 50% or more, preferably 80% or more is contained in the polyester as a sulfonic acid or a salt thereof. It is preferably derived from a sulfonic acid group.

There is no particular limitation on the method for quantifying the elemental sulfur in the polyester resin, but it can be quantified by, for example, ICP-AES (inductively coupled plasma optical emission spectroscopy). Specifically, sodium carbonate is added to the sample, water is added to the decomposed product obtained by heating and melting at 1000 ° C. to form an aqueous solution, and this is used as an aqueous solution by using SPS-4000 manufactured by Seiko Electronic Industry Co., Ltd. It can be determined by ICP-AES analysis.

In the polyester resin containing a sulfonic acid group, 1 to 10 mol% of the aromatic dicarboxylic acid is a sulfonic acid in the wholly aromatic dicarboxylic acid used in the production by the reaction of the aromatic dicarboxylic acid and glycol. Aromatic dicarboxylic acid having a group selected from an acid and a salt thereof, or 1 to 10 mol% of all glycols obtained by using a glycol having a group selected from a sulfonic acid and a salt thereof as a copolymerization component Is preferred. In particular, in order to introduce a sulfonic acid into a polyester, it is necessary to produce an aromatic dicarboxylic acid having a group selected from sulfonic acid and salts thereof in an amount of 1 to 10 mol% based on the total aromatic dicarboxylic acid. It is more preferable in terms of ease of use and the like.

Further, the polyester resin used in the present invention is preferably produced by further using polyalkylene glycol as a copolymerization component of 0.1 to 10% by mass based on the total amount of the produced polyester.

Due to these components, cracks hardly occur in the optical film formed with metal oxynitride,
When this optical film is used as a polarizing plate protective film or the like, the properties as a polarizing plate protective film, such as the adhesiveness with a polarizer and the drying property of an adhesive at the time of bonding, are greatly improved.

In the polyester resin used in the present invention, the main component of the polyester is preferably polyethylene terephthalate obtained by using terephthalic acid and ethylene glycol.

In the present invention, as will be described later, a film obtained by substantially uniaxially stretching a melt-cast film is preferably used, but a biaxially stretched film may be used. The film thus obtained is not particularly limited in film thickness, and a film having a film thickness of 5 to 500 μm is used. Even if the film has a film thickness of 5 to 40 μm, the metal oxynitride layer provided thereon has cracks. Is less likely to enter and curling is less, which is preferable. Further, since it has an appropriate moisture permeability, the drying property of the adhesive during the production of the polarizing plate was excellent, and the adhesion with the polarizer was also good. Further, the film of the present invention was less likely to have wrinkles during the production of a polarizing plate even when the film thickness was 5 to 40 μm, and was easily attached to a polarizer.

As the aromatic dicarboxylic acid used for producing the polyester used in the present invention, there are isophthalic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, etc. in addition to the above-mentioned terephthalic acid. The lower alkyl ester (an ester-forming derivative such as an anhydride or a lower alkyl ester) can be used. Examples of glycols include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, diethylene glycol and p-xylylene glycol. Above all, it is preferable that the main component is polyethylene terephthalate obtained by the reaction of terephthalic acid and ethylene glycol.

The main component being polyethylene terephthalate means that the repeating unit of polyethylene terephthalate is 8
When it is a copolymer of 0 mol% or more, or when blended, it means that it contains 80% by mass or more of polyethylene terephthalate.

As the aromatic dicarboxylic acid having a group selected from the sulfonic acids and salts thereof used for containing a sulfonic acid group in the polyester used in the present invention, 5-sodium sulfoisophthalic acid,
2-sodium sulfoisophthalic acid, 4-sodium sulfoisophthalic acid, 4-sodium sulfo-2,6-naphthalenedicarboxylic acid, 4-sodium sulfo-2,7
-Naphthalenedicarboxylic acid, 2-sodium sulfoterephthalic acid, 4-sodium sulfophthalic acid, 4-sodium sulfo-1,5-naphthalenedicarboxylic acid or its ester-forming derivatives, and their sodium to other metals (for example, potassium). , Lithium, etc.) are used.

Further, a glycol in which a group selected from sulfonic acid and its salt is introduced may be used.
The preferred compound for containing a sulfonic acid group in the polyester is an aromatic dicarboxylic acid having the sulfonic acid group or a salt thereof.

If the aromatic dicarboxylic acid component having these sulfonic acid groups or salts thereof exceeds 10 mol% of the total aromatic dicarboxylic acid used during production, the stretchability and mechanical strength will be poor. Sometimes, again 1
If it is less than mol%, the desired equilibrium water content may not be obtained.

Furthermore, the polyester used in the present invention preferably contains polyalkylene glycol as a copolymerization component, and as described above, the polyester contains polyalkylene glycol in an amount of 0.1% based on the total amount of the reaction product polyester. It is preferably produced by using 10 to 10% by mass. Further, it is more preferably 0.2 to 8 mass%. If the polyalkylene glycol content is less than 0.1% by mass, the prescribed equilibrium water content may not be obtained, and the content may be 10% by mass.
If it exceeds, the Young's modulus may decrease and the mechanical strength may be poor.

As the polyalkylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and the like are used. Among them, polyethylene glycol is preferable, and the molecular weight (number average molecular weight) is not particularly limited, but is 300 to 2000.
It is preferably 0, more preferably 600 to 10000, and particularly preferably 1000 to 5000. These molecular weights can be measured by using GPC.

The polyester used in the optical film of the present invention may be further copolymerized with other components or may be blended with other polymers, as long as the effects of the present invention are not impaired.

As aromatic dicarboxylic acids or derivatives thereof other than the above, 2,7-naphthalenedicarboxylic acid,
Aromatic dicarboxylic acids such as 1,5-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, and diphenyletherdicarboxylic acid, and lower alkyl esters thereof (anhydrides, ester-forming derivatives such as lower alkyl esters) can be used. In the production, alicyclic dicarboxylic acids such as cyclopropanedicarboxylic acid, cyclobutanedicarboxylic acid and hexahydroterephthalic acid and their derivatives (anhydrides, ester-forming derivatives such as lower alkyl esters), adipic acid, succinic acid, Aliphatic dicarboxylic acids such as oxalic acid, azelaic acid, sebacic acid and dimer acid and their derivatives (anhydrides, ester-forming derivatives such as lower alkyl esters) are used in an amount of 10 mol% or less of the total dicarboxylic acids. Good.

Examples of glycols that can be used in the present invention include ethylene glycol and the above-mentioned glycols, as well as trimethylene glycol, triethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, bisphenol A,
p, p'-dihydroxyphenyl sulfone, 1,4-
Examples thereof include bis (β-hydroxyethoxyphenyl) propane, polyalkylene (eg, ethylene, propylene) glycol, and p-phenylene bis (dimethylolcyclohexane), which are used in an amount of 10 mol% or less of the glycol used. May be used in.

The polyester used in the present invention is obtained by blocking the terminal hydroxyl group and / or carboxyl group with a monofunctional compound such as benzoic acid, benzoylbenzoic acid, benzyloxybenzoic acid and methoxypolyalkylene glycol. Alternatively, it may be modified with a trifunctional or tetrafunctional ester forming compound such as glycerin or pentaerythritol in an extremely small amount within a range where a substantially linear copolymer is obtained.

The polyester used in the present invention may be copolymerized with a bisphenol compound or a compound having a naphthalene ring or a cyclohexane ring for the purpose of improving the heat resistance of the film.

The intrinsic viscosity (Intrinsic Viscosity) of the polyester used in the present invention is 0.
Those in the range of 35 to 0.65 are preferably used. If it is less than this range, the brittleness of the obtained film may be insufficient, and if it exceeds this range, the melt viscosity during melt extrusion may be too large and the flatness may be deteriorated.

The intrinsic viscosity was calculated using an Ubbelohde viscometer. Mass ratio is about 55:45 (flow time 42.0
Adjusted to ± 0.1 seconds) and phenol, 1,1,2,2
-Using a mixed solvent with tetrachloroethane, the sample was dissolved in it and the concentration was 0.2, 0.6, 1.0 (g / d
Prepare a solution of l) (temperature 20 ° C.). Using an Ubbelohde viscometer, the specific viscosity (ηsp) at each concentration (C) was calculated, and the formula [ηsp / C] was calculated as zero concentration (C →
It was extrapolated to 0) and the intrinsic viscosity [η] was obtained. Intrinsic viscosity [η]
The unit is dl / g.

Further, the polyester used in the present invention preferably has a glass transition temperature (Tg) of 55 ° C. or higher, more preferably 60 ° C. or higher. If it is less than 55 ° C, the obtained film may be inferior in dimensional stability under high temperature and high humidity. The Tg is obtained as an average value of the temperature at which the baseline begins to become biased as measured by a differential scanning calorimeter and the temperature at which the baseline returns to a new level.

The polyester used in the present invention may contain an antioxidant. In particular, the effect becomes remarkable when the polyester contains a compound having a polyoxyalkylene group. The type of the antioxidant to be contained is not particularly limited, and various antioxidants can be used, for example, hindered phenol compounds,
Antioxidants such as phosphite compounds and thioether compounds can be mentioned. Among them, antioxidants of hindered phenolic compounds are preferable in terms of transparency. The content of the antioxidant is usually 0.
The content is 01 to 2% by mass, preferably 0.1 to 0.5% by mass.

The polyester film used in the present invention may be provided with slipperiness, if necessary. The means for imparting slipperiness is not particularly limited, but an external particle addition method of adding inert inorganic particles to polyester, an internal particle precipitation method of precipitating a catalyst added at the time of polyester synthesis, or a surfactant film The method of applying on the surface is common.

An ultraviolet absorber may be added to the polyester film of the present invention, if necessary.

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 used in the present invention include oxybenzophenone compounds, benzotriazole compounds, salicylate compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex salt compounds, triazine compounds. , Benzoate compounds, triazine compounds and the like. Further, the polymer UV absorber described in JP-A-6-148430 and the polymer UV absorber disclosed in Japanese Patent Application No. 2000-214134 are also preferably used.

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

[0059]

[Chemical 1]

In the formula, R ₁ , R ₂ , R ₃ , R ₄ and R ₅ may be the same or different and each is a hydrogen atom, a halogen atom, a nitro group, a hydroxyl group, an alkyl group, an alkenyl group, an aryl group or an alkoxy group. Represents a group, an acyloxy group, an aryloxy group, an alkylthio group, an arylthio group, a mono- or dialkylamino group, an acylamino group or a 5- or 6-membered heterocyclic group, and R ₄ and R ₅ are ring-closed to form a 5- or 6-membered carbon. You may form a ring.

Further, these groups described above may have an arbitrary substituent. Specific examples of the ultraviolet absorber represented by the general formula [1] are shown below, but the invention is not limited thereto.

UV-1: 2- (2'-hydroxy-5 '
-Methylphenyl) benzotriazole UV-2: 2- (2'-hydroxy-3 ', 5'-di-
tert-Butylphenyl) benzotriazole UV-3: 2- (2'-hydroxy-3'-tert-
Butyl-5'-methylphenyl) benzotriazole UV-4: 2- (2'-hydroxy-3 ', 5'-di-
tert-Butylphenyl) -5-chlorobenzotriazole UV-5: 2- (2'-hydroxy-3 '-(3 ",
4 ", 5", 6 "-tetrahydrophthalimidomethyl)
-5'-Methylphenyl) benzotriazole UV-6: 2,2-methylenebis (4- (1,1,3,3)
3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol) UV-7: 2- (2'-hydroxy-3'-tert-
Butyl-5'-methylphenyl) -5-chlorobenzotriazole UV-8: 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) -4-methylphenol (TINUVIN 171, Ciba) UV-9: Octyl-3- [3-tert-butyl-4]
-Hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl-4-hydroxy-5- (5-chloro-2H-benzotriazole- Two
-Yl) phenyl] propionate mixture (TINU
In the present invention, a compound represented by the following general formula [2] is preferably used as the benzophenone-based ultraviolet absorber in the present invention.

[0063]

[Chemical 2]

In the formula, Y represents a hydrogen atom, a halogen atom or an alkyl group, an alkenyl group, an alkoxy group, and a phenyl group, and these alkyl group, alkenyl group and phenyl group may have a substituent. A is a hydrogen atom,
An alkyl group, an alkenyl group, a phenyl group, a cycloalkyl group, an alkylcarbonyl group, an alkylsulfonyl group or a -CO (NH) _n-1 -D group, where D is an alkyl group,
It represents an alkenyl group or a phenyl group which may have a substituent. m and n represent 1 or 2.

In the above, the alkyl group represents, for example, a linear or branched aliphatic group having up to 24 carbon atoms, the alkoxy group represents, for example, an alkoxy group having up to 18 carbon atoms, and the alkenyl group represents For example, it is an alkenyl group having up to 16 carbon atoms and represents, for example, an allyl group or a 2-butenyl group. Also, an alkyl group, an alkenyl group,
As the substituent which may be substituted on the phenyl group, a halogen atom, for example, a chlorine atom, a bromine atom, a fluorine atom, a hydroxyl group, a phenyl group, (this phenyl group may be substituted with an alkyl group or a halogen atom, etc. Also good).

Specific examples of the benzophenone compound represented by the general formula [2] are shown below, but the invention is not limited thereto.

UV-10: 2,4-dihydroxybenzophenone UV-11: 2,2'-dihydroxy-4-methoxybenzophenone UV-12: 2-hydroxy-4-methoxy-5-sulfobenzophenone UV-13: bis ( 2-methoxy-4-hydroxy-5
-Benzoylphenylmethane) As commercially available products, TINUVIN P, T
INUVIN 324, TINUVIN 320, TI
NUVIN 326, TINUVIN 327, TIN
UVIN 328, TINUVIN 329, TINU
VIN 770, TINUVIN 780, TINUV
IN 144, TINUVIN 120, UVITEX
OB (manufactured by Ciba-Geigy Co., Ltd.) and the like can be appropriately selected and used.

The above-mentioned UV absorber preferably used in the present invention is preferably a benzotriazole-based UV absorber or a benzophenone-based UV absorber which has high transparency and is excellent in the effect of preventing deterioration of a polarizing plate or a liquid crystal element, A benzotriazole-based ultraviolet absorber that causes less unnecessary coloring is particularly preferably used. Further, the polyester film used in the present invention may contain a fluorescent whitening agent.

The fluorescent whitening agent is usually commercially available, or can be arbitrarily selected from the novel departments based on the light resistance. Examples thereof include those described in paragraph numbers [0029] to [0034] of JP-A-2002-53824. Generally optical brighteners are about 320 to about 410 nm
Of a compound having a property of absorbing light having a wavelength of about 410 nm to emitting light having a wavelength of about 500 nm. Textiles dyed with these optical brighteners have white reflected light in addition to the original yellow reflected light and blue light with a wavelength of about 410 to about 500 nm newly emitted by the fluorescent whitening agent. In addition, the energy of visible light is increased by the amount due to the fluorescence effect, and as a result, whitening is performed.

Examples of the fluorescent whitening agent further include those of the following general formula [3].

[0071]

[Chemical 3]

In the formula, R ₁ and R ₄ represent a hydrogen atom, an alkyl group or an alkoxy group, and R ₂ and R ₃ represent an alkyl group. [A] represents a substituted aryl group or a substituted ethenyl group. The compound represented by the general formula [3] is preferably a compound represented by the following general formula [4].

[0073]

[Chemical 4]

In the formula, R ₅ and R ₇ have the same meaning as R _2, and R ₆ and R ₈ have the same meaning as R ₃ . n is 1
Alternatively, it represents an integer of 2. These compounds are disclosed in JP-A-11-
It can be synthesized by the method described in No. 29556. Specific examples of the compound represented by the general formula [4] are disclosed in JP-A-2002-2002.
Paragraph Nos. [0050] to [0060] of 53824.

These fluorescent whitening agents may be added to any of the clear hard coat layer, the support and the binder layer,
It is also possible to use two or more types in combination. The addition amount varies depending on the thickness of the layer, the properties of the fluorescent whitening agent, the presence or absence of the ultraviolet absorber, the properties, and the addition amount, and therefore cannot be uniquely determined. Generally, 0.1-30% by mass, preferably 4-15% by mass is sufficient for a layer having a heat of 50 μm.

The method of synthesizing the polyester used in the present invention is not particularly limited, and the polyester can be produced by the conventionally known method for producing polyester as described above. For example, a direct esterification method in which a dicarboxylic acid component is directly esterified with a diol component, first a dialkyl ester is used as a dicarboxylic acid component, and an ester exchange reaction is performed between this and the diol component, and this is heated under reduced pressure. A transesterification method in which the excess diol component is removed to perform polymerization can be used. At this time, if necessary, a transesterification catalyst or a polymerization reaction catalyst may be used, or a heat stabilizer may be added. At this time, it is preferable that aromatic dicarboxylic acids having a metal sulfonate group, which is a copolymerization component, or polyethylene glycol be added after the transesterification reaction to carry out polycondensation. In addition, in each process during synthesis, anti-coloring agents, antioxidants, crystal nucleating agents, slip agents, stabilizers, anti-blocking agents, UV absorbers, optical brighteners, viscosity modifiers, defoamers, clarifiers. Further, an antistatic agent, a pH adjusting agent, a dye, a pigment or the like may be added.

Next, a method for producing the polyester film used for the optical film of the present invention will be described.

As the polyester film used in the present invention, a biaxially stretched film having a stretching ratio of 1.0 to 10.0 is used, and a substantially uniaxially stretched film is particularly preferably used. The substantially uniaxially stretched polyester film is obtained by stretching mainly in either one direction in the biaxial stretching film formation. That is, in the present invention,
Polyester film has a draw ratio of 1.00 in one direction
2.5 times, the draw ratio in the direction orthogonal thereto is 2.5 to 1
It is preferable that the polyester film is biaxially stretched to 0 times, more preferably 1.0 to 2.0 times in the longitudinal direction and 2.5 to 7 times in the transverse direction. It is a biaxially stretched polyester film, and more preferably has a longitudinal draw ratio of 1.1 to 1.8 times and a transverse draw ratio of 3.0 to 6.0 times. It is a polyester film. It is preferable to increase the draw ratio in one direction, and the ratio of the draw ratios (the higher draw ratio in either the vertical or horizontal direction / the lower draw ratio in the vertical or horizontal direction).
Is preferably 2 or more, more preferably 4 or more, and preferably 6 or more. Further, it is preferably stretched 4 times or more, more preferably 5 to 7 times the area ratio of the unstretched material after stretching.

The above polyester film can be obtained by a conventionally known method without any particular limitation.
It can be performed by the following method. In this case, the longitudinal direction means the film forming direction of the film (longitudinal direction), and the lateral direction means the direction perpendicular to the film forming direction of the film (width direction).

First, the raw material polyester is molded into pellets, dried in hot air or vacuum, and then melt-extruded.
A sheet is extruded from a die, adhered to a cooling drum by an electrostatic application method or the like, and then cooled and solidified to obtain an unstretched sheet. Next, the obtained unstretched sheet is heated to a temperature within the range of Tg + 100 ° C. from the glass transition temperature (Tg) of polyester through a plurality of roll groups and / or a heating device such as an infrared heater to carry out single-stage or multi-stage longitudinal stretching. Is.

Next, the longitudinally stretched polyester film obtained as described above is transversely stretched within the temperature range of Tg to Tm (melting point) -20 ° C. and then heat set.

In the case of transverse stretching, it is preferable to transversely stretch while gradually increasing the temperature difference in the range of 1 to 50 ° C. in the stretching region divided into two or more because the distribution of the physical properties in the width direction can be reduced.
After further transverse stretching, the film is subjected to T at or below its final transverse stretching temperature.
It is preferable to maintain the temperature in the range of g-40 ° C or higher for 0.01 to 5 minutes because the distribution of physical properties in the width direction can be further reduced.

The heat setting is generally 0.5 to 30 at a temperature higher than the final transverse stretching temperature and within a temperature range of Tm-20 ° C. or lower.
Heat set for 0 seconds. At this time, it is preferable to heat-set while sequentially raising the temperature difference in the range of 1 to 100 ° C. in the two or more divided regions.

The heat-fixed film is usually cooled to Tg or less, and the clip holding portions at both ends of the film are cut and wound up. At this time, within the temperature range not higher than the final heat setting temperature and not lower than Tg, 0.1 to 1 in the horizontal direction and / or the vertical direction.
It is preferable to perform 0% relaxation treatment. Further, for cooling, it is preferable to gradually cool from the final heat setting temperature to Tg at a cooling rate of 100 ° C. or less per second. The means for cooling and relaxing treatment is not particularly limited and can be carried out by conventionally known means, but it is particularly preferable to perform these treatments while sequentially cooling in a plurality of temperature regions from the viewpoint of improving the dimensional stability of the film. still,
The cooling rate is T1, the final heat setting temperature, and t is the time required for the film to reach Tg from the final heat setting temperature,
It is a value obtained by (T1-Tg) / t.

The more optimum heat setting conditions, cooling conditions, and relaxation treatment conditions differ depending on the polyester constituting the film. Therefore, the physical properties of the obtained stretched film are measured and appropriately adjusted so as to have the desired properties. Just decide.

In the production of the above film, functional layers such as an antistatic layer, a slipping layer, an adhesive layer and a barrier layer may be coated before and / or after stretching. At this time, various surface treatments such as corona discharge treatment, atmospheric pressure plasma treatment, chemical treatment and the like can be applied as necessary.

The clip gripping portions on both ends of the cut film are pulverized or, if necessary, subjected to granulation treatment, depolymerization / repolymerization or the like, and then used as raw materials for films of the same kind or It may be reused as a raw material for films of different types.

In the present invention, the refractive index in the plane direction of the polyester film formed as described above is the refractive index in the lateral direction (n _TD ) and the refractive index in the longitudinal direction (n _MD ).
The absolute value of the difference | n _TD −n _MD | is preferably 0.05 or less, more preferably 0.04 or less, still more preferably 0.025 or less.

The thickness of the polyester film used in the present invention is usually 3 to 500 μm, preferably 5 to 120 μm.
μm, further preferably 5 to 40 μm, more preferably 1
It is 0 to 35 μm. Before winding, knurling with a height of 1 to 25% of the film thickness on both widthwise ends, width of 0.1 to 3c
It is preferable to perform processing of about m.

The retardation R ₀ (nm) in the in-plane direction of the polyester film used in the present invention
Is preferably 1000 nm or less, and 800 n
It is more preferably m or less, and further preferably 500 nm or less.

The polyester film used in the present invention has an angle of 0 ° ± 15 ° or 90 ° between the direction in which the in-plane refractive index is maximum and the width direction of the film (long direction of the film). It is preferably ± 15 °, more preferably 0 ° ± 10 ° or 90 ° ± 10 °, more preferably 0 ° ± 5 ° or 90 ° ± 5 °, and 0 ° ± 1 ° or 9
More preferably, it is 0 ° ± 1 °.

The polyester film used in the present invention may be a single (single layer) film made of the above polyester film, but a plurality of films containing at least one layer made of the above polyester may be used as long as the effects of the present invention are not impaired. It may be a multi-layer film comprising the resin layer.
When the polyester layer is A and the other resin layers are B and C, for example, A / B, A / B / A, B / A / B, B /
It can be configured like A / C. Of course, a structure having four or more layers can also be used. With such a multi-layer structure, a plurality of functions can be imparted simultaneously by, for example, laminating a film having high strength and water barrier properties on the core layer and the outer layer.

As the other resin layer, acrylic resin, cellulose ester resin (cellulose triacetate, cellulose diacetate, cellulose acetate propionate), polycarbonate, norbornene resin or the like may be used, or the above polyester or the like is preferably used. For example, a multilayer structure of a sulfonic acid group-containing polyester layer / a sulfonic acid group-free polyester layer (for example, PET) / a sulfonic acid group-containing polyester layer can be used.

When fine particles such as a matting agent are added to impart slipperiness, the effect can be obtained by adding them only to the outermost layer, so that it is possible to impart a function without deteriorating transparency and the like. Become.

The fine particles that can be added are not particularly limited, but examples thereof include fine particles of an inorganic compound and fine particles of an organic compound.

As the inorganic compound, a compound containing silicon,
Silicon dioxide, aluminum oxide, zirconium oxide, titanium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate,
Aluminum silicate, magnesium silicate, calcium phosphate and the like are preferable, and more preferable are inorganic compounds containing silicon and zirconium oxide, but silicon dioxide is preferably used. As the fine particles of silicon dioxide, for example, Aerosil R972, R972V, R974, R
812, 200, 200V, 300, R202, OX5
Commercially available products such as 0 and TT600 (all manufactured by Nippon Aerosil Co., Ltd.) can be used. Examples of fine particles of zirconium oxide include, for example, Aerosil R976 and R811 (above,
Commercial products such as Nippon Aerosil Co., Ltd. can be used.

As the organic compound, for example, polymers such as silicone resin, fluorine resin and acrylic resin are preferable, and among them, silicone resin is preferably used. Among the above-mentioned silicone resins, those having a three-dimensional network structure are particularly preferable. For example, Tospearl 10
3, 105, 108, 120, 145, 31
Commercial products having trade names such as 20 and 240 (above, manufactured by Toshiba Silicone Co., Ltd.) can be used.

The primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 5 to 16 nm, and particularly preferably 5 to 12 nm from the viewpoint of suppressing haze to a low level.

As a method for producing a multilayer film, a method by coextrusion, a method by extrusion lamination, a method by dry lamination or the like can be preferably used.

In the present invention, it is preferable that the surface of the optical film has conductivity, and the surface specific resistance (23 ° C., 2
5% RH) is preferably 1 × 10 ¹² Ω / cm ² or less. More preferably, 1 × 10 ¹¹ Ω / cm ² or less,
More preferably, it is 1 × 10 ¹⁰ Ω / cm ² or less.

In the present invention, conductivity can be imparted to the optical film by containing a hygroscopic substance or a conductive substance. Examples of the substance that imparts the conductivity include a surfactant, a conductive polymer, and an inorganic metal oxide.

As the surfactant that can be used,
It may be anionic, cationic, amphoteric or nonionic. Examples of the anionic surfactant include alkyl carboxylates, alkyl sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkyl sulfates, alkyl phosphates, N-acyl-N-alkyl taurines. Acid, sulfosuccinates, sulfoalkyl polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl phosphates, and other acidic groups such as carboxy groups, sulfo groups, phospho groups, sulfate ester groups, phosphate ester groups, etc. Those containing are preferable.

Examples of the cationic surfactant include, for example,
Preferred are alkylamine salts, aliphatic or aromatic quaternary ammonium salts, heterocyclic quaternary ammonium salts such as pyridinium and imidazolium, and phosphonium or sulfonium salts containing an aliphatic or heterocyclic ring.

As the amphoteric surfactant, for example, amino acids, aminoalkyl sulfonic acids, aminoalkyl sulfuric acid or phosphoric acid esters, alkyl betaines, amine oxides and the like are preferable.

Examples of the nonionic surfactant include, for example,
Saponins (steroids), alkylene oxide derivatives (for example, polyethylene glycol, polyethylene glycol / polypropylene glycol condensates, polyethylene glycol alkyl ethers or polyethylene glycol alkylaryl ethers, polyethylene glycol esters, polyethylene glycol sorbitan esters, polyalkylene glycols) Alkyl amines or amides, polyethylene oxide adducts of silicone), glycidol derivatives (for example, alkenyl succinic acid polyceride, alkyl phenol polyglyceride), and alkyl esters such as polyhydric alcohol fatty acid esters are preferable.

The conductive polymer is not particularly limited and may be any of anionic, cationic, amphoteric and nonionic, and among them, anionic and cationic are preferable. More preferred are sulfonic acid-based or carboxylic acid-based polymers when anionic, and tertiary amine-based or quaternary ammonium-based polymers or latexes when cationic.

Examples of these electrically conductive polymers include anionic polymers or latexes described in JP-B-52-25251, JP-A-51-29923 and JP-B-60-48024, and JP-B-57-18176 and 57-57. -56
059, 58-56856, U.S. Pat. No. 4,11.
Examples thereof include the cationic polymers or latexes described in No. 8,231.

For example, an antistatic layer or a conductive layer can be provided by the plasma treatment described in JP-A-2000-33720.

The optical film of the present invention can also be used as a polarizing plate by laminating it on at least one surface of a polarizer. The other side of the polarizer is a known polarizing plate protective film (cellulose film, for example, Konikak KC8UX).
2MW, KC4UX2MW) may be stuck together,
You may laminate the optical film of this invention. When the optical film of the present invention is used as a polarizing plate protective film, the conventional polyester film does not have a curl, and curls remain even after being used as a polarizing plate, or the adhesive part peels off due to a strong curl. There was a problem that it was easy,
In the optical film of the present invention, since the curling habit is easily eliminated,
It is especially suitable for a polarizing plate protective film. In particular, the curl can be easily eliminated by immersing in water or an aqueous solution or applying steam before or after bonding with the polarizer, and a polarizing plate having excellent flatness can be provided.
Further, since the optical film of the present invention has a hygroscopic expansion coefficient close to that of triacetyl cellulose as compared with conventional polyesters, one of the polarizers has a cellulose ester-based polarizing plate protective film such as triacetyl cellulose, and the other has the present invention. Even a hybrid polarizing plate using an optical film is excellent in that the polarizing plate attached to the liquid crystal display device is less likely to peel off or wrinkle due to moisture absorption or the like, and is excellent.

As the adhesive used for laminating the optical film of the present invention and the polarizer, one having sufficient adhesiveness, transparency and not impairing the polarizing function is preferably used. For example, polyester adhesive Agents, polyacrylic adhesives, epoxy adhesives, cyanoacrylate adhesives, polyurethane adhesives, polyvinyl alcohol adhesives such as polyvinyl alcohol and polyvinyl butyral, and the like.

Various surface treatments such as corona discharge treatment, glow discharge treatment, ultraviolet ray treatment, flame treatment, discharge plasma treatment in atmospheric pressure gas, chemical treatment and the like can be applied as necessary to improve adhesion. Further, an undercoat layer may be coated to improve the adhesiveness. As the undercoat layer, a hydrophilic colloid layer having excellent adhesiveness to the polarizer is particularly preferable.

For example, in order to improve the adhesiveness with a polarizer as a polarizing plate protective film, JP-A-2000-3567 is used.
By performing the plasma treatment by the method of 14 or the like, it is possible to further improve the adhesiveness when a polyvinyl alcohol-based adhesive or the like is used.

The optical film of the present invention is characterized in that a metal oxynitride layer is formed on a polyester film directly or through another layer, but it is formed through a resin cured layer or another layer. Is more preferable. It is preferable to form a thermosetting resin layer or an actinic radiation curing resin layer on the polyester film obtained as described above, and it is particularly preferable to provide an ultraviolet curing resin layer.

The cured resin layer may have various functions, and may be, for example, an antiglare layer or a clear hard coat layer. The cured resin layer is preferably a layer formed by polymerizing a component containing at least one monomer having an ethylenically unsaturated bond. The resin layer formed by polymerizing a component containing a monomer having an ethylenically unsaturated bond,
A layer formed by curing an actinic ray curable resin or a thermosetting resin is preferably used, but an actinic ray curable resin layer is particularly preferably used. Here, the actinic ray curable resin layer refers to a layer containing a resin which is cured by a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays and electron beams as a main component.

Typical examples of the actinic ray curable resin include an ultraviolet curable resin and an electron beam curable resin, but a resin which is cured by irradiation with an actinic ray other than an ultraviolet ray or an electron beam may be used.

Examples of the UV curable resin include UV curable acrylic urethane resin, UV curable polyester acrylate resin, UV curable epoxy acrylate resin, UV curable polyol acrylate resin, and UV curable epoxy resin. Can be mentioned.

Specific examples include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate and the like. it can.

As the UV-curable acrylic urethane type resin, generally, a product obtained by reacting a polyester polyol with an isocyanate monomer or a prepolymer is further added with 2-hydroxyethyl acrylate or 2-hydroxyethyl acrylate.
Examples thereof include hydroxyethyl methacrylate (hereinafter, acrylate is referred to as acrylate only including acrylate) and 2-hydroxypropyl acrylate, which are easily formed by reacting an acrylate-based monomer having a hydroxyl group. Those described in JP-A-59-151110 can be used.

Examples of the UV-curable polyester acrylate resin include those generally formed easily by reacting a polyester polyol with 2-hydroxyethyl acrylate or 2-hydroxyacrylate monomer. Those described in No. 151112 can be used.

Specific examples of the UV-curable epoxy acrylate-based resin include epoxy acrylate as an oligomer, a reactive diluent and a photoreaction initiator added thereto, and a reaction product. Kaihei 1-
The one described in No. 105738 can be used.

Specific examples of these photoreaction initiators include benzoin and derivatives, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone and their derivatives. You may use it with a photosensitizer.

The above photoreaction initiator can also be used as a photosensitizer. When using an epoxy acrylate-based photoreactive agent, n-butylamine, triethylamine, tri-
A sensitizer such as n-butylphosphine can be used.

As the resin monomer, for example, a monomer having one unsaturated double bond is methyl acrylate,
Common monomers such as ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, vinyl acetate 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.

Commercially available UV-curable resins usable in the present invention include ADEKA OPTOMER KR / BY series: KR-400, KR-410, KR-550, KR.
-566, KR-567, BY-320B (manufactured by Asahi Denka Co., Ltd.); Koei Hard A-101-KK, A-1
01-WS, C-302, C-401-N, C-50
1, M-101, M-102, T-102, D-10
2, NS-101, FT-102Q8, MAG-1-P
20, AG-106, M-101-C (Kouei Chemical Co., Ltd.)
Made); SEIKA BEAM PHC2210 (S), PHC X
-9 (K-3), PHC2213, DP-10, DP-
20, DP-30, P1000, P1100, P120
0, P1300, P1400, P1500, P160
0, SCR900 (manufactured by Dainichiseika Kogyo KK); KRM7
033, KRM7039, KRM7130, KRM71
31, UVECRYL29201, UVECRYL29
202 (manufactured by Daicel UCB Ltd.); RC-5
015, RC-5016, RC-5020, RC-50
31, RC-5100, RC-5102, RC-512
0, RC-5122, RC-5152, RC-517
1, RC-5180, RC-5181 (manufactured by Dainippon Ink and Chemicals, Inc.); Aurex No. 340 Clear (manufactured by China Paint Co., Ltd.); Sunrad H-601 (manufactured by Sanyo Kasei Co., Ltd.); SP-1509, SP-1507
(Showa High Polymer Co., Ltd.); RCC-15C (Grace
Japan Co., Ltd.), Aronix M-6100, M-
8030, M-8060 (manufactured by Toagosei Co., Ltd.) and the like can be appropriately selected and used.

These actinic ray curable resin layers can be applied by a known method. As a light source for curing the ultraviolet curable resin by a photo-curing reaction, any light source that emits ultraviolet light can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a super high pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, etc. can be used. Irradiation conditions vary depending on each lamp, but the amount of irradiation light is 20 to 10,000 mJ / cm
^It may be about ² and preferably 50 to 2000 mJ /
cm ² . It can be efficiently formed by using a sensitizer having an absorption maximum in the near-ultraviolet region to the visible light region.

The organic solvent for the ultraviolet curable resin layer composition coating liquid is appropriately selected from, for example, hydrocarbons, alcohols, ketones, esters, glycol ethers, and other organic solvents, or these are selected. Can be mixed and used. For example, propylene glycol monoalkyl ether (the number of carbon atoms of the alkyl group is 1 to 4) or propylene glycol monoalkyl ether acetic acid ester (the number of carbon atoms of the alkyl group is 1 to 4) is 5% by mass or more, more preferably 5 It is preferable to use the above organic solvent that is contained in an amount of -80% by mass or more.

As the method for applying the ultraviolet-curable resin composition coating liquid, the above-mentioned methods can be used. The coating amount is suitably 0.1 to 30 μm as a wet film thickness, preferably 0.5 to 15 μm. The ultraviolet curable resin composition is preferably irradiated with ultraviolet rays during or after coating and drying, and the irradiation time is preferably 0.5 seconds to 5 minutes, and 3 seconds from the viewpoint of curing efficiency or work efficiency of the ultraviolet curable resin. ~ 2 minutes is more preferred.

Fine particles of an inorganic compound or an organic compound may be added to the coating solution for the cured resin layer in order to prevent blocking and to enhance scratch resistance. It is almost similar to the fine particles of the agent. The average particle size of these fine particle powders is preferably 0.005 μm to 5 μm and 0.01 to 1 μm.
Particularly preferably m. The ratio of the ultraviolet curable resin composition to the fine particle powder is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin composition.

The UV-curable resin layer is JIS-B-0601.
Even if it is a clear hard coat layer having a center line average roughness (Ra) of 1 to 50 nm, the Ra is 0.1 to 1 μm.
m may be an antiglare layer. The refractive index of the ultraviolet curable resin layer is 1.5 to 1.7, preferably 1.52 to 1.6.
It is preferably 5.

In the present invention, a metal oxynitride thin film layer whose film thickness unevenness is remarkably improved can be formed on these layers by plasma discharge treatment.

In the present invention, the method for providing the metal oxynitride thin film layer is not particularly limited, and the metal oxynitride thin film layer can be formed by coating, sputtering, vapor deposition, or CVD. However, it should be particularly formed by plasma CVD even during CVD. Is preferred.

The plasma discharge treatment under atmospheric pressure or a pressure in the vicinity thereof as the method for forming the metal oxynitride layer of the present invention is performed by using the plasma discharge treatment apparatus as described below.

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

In FIG. 1, this device has a pair of rotating electrodes 10A and 10B, and a power supply 80 capable of applying a voltage for generating plasma discharge is provided to the rotating electrodes 10A and 10B by voltage supply means 81 and 82. Connected through.

The rotating electrodes 10A and 10B convey the polyester film while winding it, and are preferably roll electrodes or belt-shaped electrodes. In FIG. 1, roll electrodes are shown.

The gap between these rotating electrodes (electrode gap) is a place where discharge is performed, and is set to an interval at which the polyester film F can be conveyed. The gap between the electrodes becomes the discharge part 50.

This electrode gap is maintained at or near atmospheric pressure, and the reaction gas supply unit 30
The reaction gas G is supplied more uniformly in the width direction, and the surface of the polyester film F is plasma-discharge treated.

Here, the polyester film F unwound from the original winding roll or the polyester film F conveyed from the previous step is transferred through the guide roll 20 while being in contact with the rotating electrode 10A rotating in the transfer direction. After passing through the discharge part 50, a thin film is formed on the surface of the polyester film F.

The polyester film F once discharged from the discharge section 50 is U-turned by the U-turn rolls 11A to 11D, and this time, the polyester film F is rotated.
The thin film is formed while being transferred while being in contact with the rotating electrode 10B rotating in the direction opposite to A, passing through the discharge part 50 again, and further subjected to plasma discharge treatment on the surface of the polyester film F on which the thin film has been formed. . The U-turn is usually made in 0.1 second to 1 minute.

The reaction gas G used for the treatment is discharged from the gas discharge port 40 as the exhaust gas G'after the reaction. Particles and decomposition products contained in the exhaust gas G ′ are removed by a filter or activated carbon treatment, and the rare gas can be recovered and reused.

In the figure, the thin film formed on the polyester film F is omitted. The polyester film F having a thin film formed on the surface is conveyed through the guide roller 21 in the next step or in the direction of a winding roll (not shown).

Therefore, the polyester film F is reciprocated in the discharge part 50 while being in close contact with the rotary electrodes 10A and 10B, and is subjected to plasma discharge treatment.

Although not shown, the rotating electrodes 10A and 10B, the guide rolls 20 and 21, and the U-turn roll 11 are not shown.
It is preferable that the devices such as A-11D, the reaction gas supply unit 30, and the gas discharge port 40 are enclosed and housed in a plasma discharge processing container that is shielded from the outside.

Although not shown, a temperature control medium for controlling the temperature of the rotating electrodes 10A and 10B is circulated as necessary to control the surface temperature of each electrode to a predetermined value. It has become. Usually, it is preferable to control the temperature from room temperature to 200 ° C, preferably 50 to 120 ° C.
It is particularly preferable to control the temperature to 60 to 100 ° C. The fluctuation of the electrode surface temperature and the unevenness of width are preferably within ± 1 ° C, and particularly preferably within ± 0.1 ° C.

FIG. 2 is a diagram showing an example of a plasma discharge treatment apparatus having a rotating electrode and a fixed electrode useful for forming the metal oxynitride thin film layer of the present invention.

A polyester film F having a rotary electrode 110 and a plurality of fixed electrodes 111 arranged so as to face the rotary electrode 110, which is not shown in the drawing, or the polyester film F conveyed from the previous step is a guide roll 120 and a nip roll 1.
The polyester film F is guided to the rotating electrode 110 via 22 and is in contact with the rotating electrode 110.
Of the reaction gas generator 13 transferred to the discharge part 150 under atmospheric pressure or a pressure near the atmospheric pressure.
The reaction gas G prepared in 1 is supplied from the air supply pipe 130, and a thin film is formed on the polyester film surface facing the fixed electrode 111.

A power supply 180 capable of applying a voltage for generating plasma discharge is connected to the rotary electrode 110 and the fixed electrode via voltage supply means 181 and 182.

Further, the rotating electrode 110, the fixed electrode 111,
The discharge unit 150 is covered with the plasma discharge processing container 190,
It is cut off from the outside world. The treated exhaust gas G ′ is discharged from the gas exhaust port 140 at the bottom of the processing chamber.

The plasma discharge-treated polyester film F is conveyed to the next step or a winding roll (not shown) through the nip roll 123 and the guide roll 121.

Partitioning plates 124 and 125 from the outside are provided at the nip rolls 122 and 123 of the entrance / exit portion of the plasma discharge treatment container for the polyester film F, and air entrained in the polyester film F together with the nip roll 122 from the outside is provided. In addition, the reaction gas G or the exhaust gas G ′ is prevented from leaking to the outside at the outlet. Although not shown, the rotary electrode 110 and the fixed electrode 111 circulate a temperature-controlled medium for temperature adjustment, if necessary.
The temperature can be controlled similarly to the rotary electrodes 10A and 10B in FIG.

As described above, in the present invention, the polyester film on which the thin film is formed is preferably subjected to plasma discharge treatment while being transferred on the rotating electrode.

The surface of the rotary electrode in contact with the polyester film is required to have high smoothness, and the surface roughness of the rotary electrode is such that the maximum height (Rmax) of the surface roughness defined by JIS-B-0601 is 10 μm or less. Is more preferable, 8 μm or less is more preferable, and 7 μm or less is particularly preferable. Further, dust, foreign matter, particles, etc. on the rotating electrode cause defects in the formed thin film, and therefore it is desired to remove them with an adhesive roll, brush, air blower or the like.

The surface of the electrode used is preferably coated with a solid dielectric material, and particularly preferably the conductive base material such as metal is 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.

Particularly preferably, after spraying ceramics,
It is desirable that the dielectric material is a ceramic-coated dielectric material that is sealed with an inorganic material. Here, as the conductive base material such as metal, silver, platinum, stainless steel, aluminum, iron,
Examples of the metal include titanium and titanium alloys, but 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. Is preferably used,
Among these, borate glass is more preferably used because it is easy to process.

In the present invention, the 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 thereof, but in a rotating electrode using a roll, it is preferable to supply a medium inside to control the temperature of the electrode surface and the temperature of the polyester film.

As the medium, an insulating material such as distilled water, oil, especially silicone oil is preferably used.

The temperature of the polyester film during the discharge treatment varies depending on the treatment conditions, but is preferably room temperature to 200 ° C. or lower, more preferably 50 to 120 ° C. or lower,
More preferably, it is 60 to 110 ° C.

During the discharge treatment, it is desirable that temperature unevenness does not occur particularly in the width direction of the polyester film surface, preferably within ± 5 ° C., more preferably within ± 1 ° C., and particularly preferably within ± 1 ° C. It is preferably within ± 0.1 ° C.

In the present invention, the electrode gap is determined in consideration of the thickness of the solid dielectric, the applied voltage and frequency, the purpose of utilizing plasma, and the like. The shortest distance between the solid dielectric and the electrode when the solid dielectric is installed on one of the electrodes, and the distance between the solid dielectrics when the solid dielectric is installed on both of the electrodes are uniform in all cases. From the viewpoint of generating discharge plasma, it is preferably 0.5 to 20 mm, particularly preferably 1 ± 0.5 mm.

In the present invention, the discharge part in the electrode gap is
The mixed gas generated by the gas generator is controlled in flow rate and introduced into the plasma discharge section through the reaction gas supply port. The concentration and flow rate of the reaction gas are appropriately adjusted, but it is preferable to supply the processing gas into the electrode gap at a speed sufficient for the transport speed of the polyester film. For example, width direction 1c
It is preferable to supply the reaction gas at a flow rate of 0.1 to 200 L / min per m. It is desirable to set the flow rate and discharge conditions so that most of the supplied reaction gas reacts in the discharge part and is used for thin film formation.

In order to prevent atmospheric air from entering the discharge part and prevent the reaction gas from leaking out of the apparatus, it is preferable that the electrodes and the polyester film being transferred are entirely enclosed and shielded from the outside. In the present invention, the atmospheric pressure of the discharge part is maintained at or near atmospheric pressure.

Here, the atmospheric pressure vicinity means 20 to 200 kP.
It represents the pressure of a, but in order to obtain the effect described in the present invention preferably, it is preferably 93 to 110 kPa. It is preferable that the discharge part has a slightly positive pressure with respect to the atmospheric pressure outside the apparatus, and the atmospheric pressure outside the plasma apparatus +0.1 kPa to 5 kPa
Is more preferable.

In the plasma discharge treatment apparatus useful in the present invention, one electrode is connected to a power source to apply a voltage, and the other electrode is grounded to earth to generate discharge plasma, which produces stable plasma. Preferred for.

The value of the voltage applied to the electrodes from the high frequency power source used in the present invention is appropriately determined.
5 to 10 kV, and applied frequency is 1 kHz to 15
It may be adjusted to 0 MHz and the waveform may be a pulse wave or a sine wave. Especially when the frequency exceeds 100 kHz and 50
It is preferable to set the frequency to MHz or less because a discharge portion (discharge space) can be obtained.

The discharge density in the discharge part is 5 to 1000 W.
-Min / m ² is preferable, and particularly 50 to 50
It is preferably 0 W · min / m ² .

The plasma discharge processing unit is Pyrex (R)
It is desirable that it is appropriately surrounded by a glass processing container or the like, and if it can be insulated from the electrodes, it can be made of metal. 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, by surrounding the side surface of the discharge part, the side surface of the rotating electrode, the polyester film conveying part, etc., the reaction gas and the exhaust gas can be appropriately supplied to the discharge part and exhausted.

The reaction gas used in the method for forming the metal oxynitride thin film layer of the present invention will be described. The reaction gas for forming the thin film layer preferably contains nitrogen or a rare gas. That is, the reactive gas is preferably a mixed gas of nitrogen or a rare gas and a reactive gas described later. here,
The rare gas may be an element belonging to Group 18 of the periodic table, specifically, each element such as helium, neon, argon, krypton, xenon, and radon. In the present invention, among them, helium element, argon Elements can be preferably used. The concentration of the rare gas in the reaction gas is preferably 90% or more in order to generate stable plasma discharge, and is preferably 90 to 99.99% by volume. The rare gas is used to generate a stable plasma discharge, and the reactive gas is ionized or radicalized in the plasma, and deposited or adhered to the surface of the substrate to form a thin film.

In the present invention, thin films having various functions can be formed on the polyester film by using various reactive gases. For example, a low refractive index layer can be formed by using a fluorine-containing organic compound or a silicon compound as the reactive gas, and can be used as an antireflection layer.

Further, an organometallic compound, a metal hydrogen compound,
Metal halides can be used to form these metal oxide layers (including metal oxide nitride layers) or metal nitride layers, and these layers can be used as medium-refractive-index layers or high-refractive-index layers. It may be a refractive index layer, or a conductive layer or an antistatic layer. A metal oxide layer is particularly preferably used.

Further, a fluorine-containing organic compound can be used to form an antifouling layer or a low refractive index layer, and a silicon compound can be used to form a gas barrier layer, a low refractive index layer or an antifouling layer. The present invention is particularly preferably used for forming an antireflection layer formed by alternately stacking high and medium refractive index layers and low refractive index layers.

The thickness of the metal oxynitride layer formed in the present invention is preferably in the range of 1 to 1000 nm.

In the atmospheric pressure plasma treatment, the fluorine compound-containing layer can be formed by using the fluorine-containing organic compound as the source gas.

As the fluorine-containing organic compound, fluorocarbon gas, fluorohydrocarbon gas and the like are preferable. Specifically, as the fluorine-containing organic compound, for example, a carbon fluoride compound such as carbon tetrafluoride, carbon hexafluoride, tetrafluoroethylene, propylene hexafluoride, and cyclobutane octafluoride;
Fluorinated hydrocarbon compounds such as methane difluoride, ethane tetrafluoride, propylene tetrafluoride, propylene trifluoride, and cyclobutane octafluoride; further, trifluoromethane monochloride, monochlorodifluoromethane, dichloride Fluorinated hydrocarbon compounds such as tetrafluorocyclobutane halides, alcohols,
Examples thereof include fluorine-substituted compounds of organic compounds such as acids and ketones. These may be used alone or in combination.
As the above-mentioned fluorohydrocarbon gas, difluoromethane,
Examples thereof include ethane tetrafluoride, propylene tetrafluoride, propylene trifluoride, and the like. Further, halides of fluorohydrocarbon compounds such as methane monochloride trifluoride, methane monochloride difluoride, and cyclobutane tetrachloride dichloride, and fluorine-substituted compounds of organic compounds such as alcohols, acids, and ketones can be used. However, the present invention is not limited to these.

In addition, these compounds may have an ethylenically unsaturated group in the molecule. Further, the above compounds may be mixed and used.

When a fluorine-containing organic compound is used as the reactive gas useful in the present invention, from the viewpoint of forming a uniform thin film on the polyester film by plasma discharge treatment, the fluorine-containing organic compound as the reactive gas in the reaction gas is used. The content of is preferably 0.01 to 10% by volume, and more preferably 0.1 to 5% by volume.

When the fluorine-containing organic compound preferably used in the present invention is a gas at room temperature and atmospheric pressure, it can be used as it is as a component of the reactive gas.

When the fluorine-containing organic compound is a liquid or a solid at room temperature and atmospheric pressure, it may be used by being vaporized by a vaporizing means, for example, by heating, depressurizing, etc., and used by dissolving it in a suitable organic solvent. May be.

Examples of the silicon compound as the reactive gas useful in the present invention include organometallic compounds such as dimethylsilane and tetramethylsilane, metal hydrogen compounds such as monosilane and disilane, silane dichloride, silane trichloride and tetrasilane. Metal halide compounds such as silicon fluoride, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, and other alkoxysilanes, organosilanes, etc. It is preferable to use, but not limited to. Also,
These can be used in appropriate combination. Alternatively, another organic compound may be added to change or control the physical properties of the film.

In the present invention, when a silicon compound is used as the reactive gas, from the viewpoint of forming a uniform thin film on the polyester film by discharge plasma discharge treatment, the content of the silicon compound as the reactive gas in the reaction gas is ,
It is preferably 0.01 to 10% by volume, and more preferably 0.1 to 5% by volume.

The organometallic compound as the reactive gas useful in the present invention is not particularly limited, but Al, As,
Au, B, Bi, Sb, Ca, Cd, Cr, Co, C
u, Fe, Ga, Ge, Hg, In, Li, Mg, M
n, Mo, Na, Ni, Pb, Pt, Rh, Se, S
Examples thereof include metal compounds for forming metal oxynitrides such as i, Sn, Ti, Zr, Y, V, W and Zn.

For example, in order to form the high refractive index layer of the antireflection layer, a titanium compound is preferable. Specifically, for example, an organic amino metal compound such as tetradimethylaminotitanium, metal hydrogen such as monotitanium or dititanium. Compound,
Examples thereof include metal halogen compounds such as titanium dichloride, titanium trichloride and titanium tetrachloride, and metal alkoxides such as tetraethoxy titanium, tetraisopropoxy titanium and tetrabutoxy titanium.

In the present invention, the above-mentioned silicon compound and organometallic compound are metal hydrogen compounds, from the viewpoint of handling.
Among them, metal alkoxides are preferable, and metal alkoxides are preferably used because they do not generate corrosiveness or harmful gas and have less contamination in the process.

In the present invention, when an organometallic compound is used as the reactive gas, from the viewpoint of forming a uniform thin film on the polyester film by plasma discharge treatment, the content of the organometallic compound as the reactive gas in the reaction gas is high. Is preferably 0.01 to 10% by volume, more preferably 0.1 to 5% by volume. In order to introduce a metal compound such as a silicon compound or a titanium compound into the discharge part, both may be used in a gas, liquid or solid state at normal temperature and pressure. In the case of gas, it can be introduced into the discharge part as it is, but in the case of liquid or solid, it can be used by being vaporized by vaporizing means such as heating, decompression, ultrasonic irradiation, spraying and the like.

When a metal compound such as a silicon compound or a titanium compound is vaporized by heating and used, a metal alkoxide such as tetraethoxysilane or tetraisopropoxytitanium which is liquid at room temperature and has a boiling point of 200 ° C. or lower is used. It is suitable for the method of forming the metal oxynitride thin film layer of the present invention. The metal alkoxide may be diluted with an organic solvent before use, and examples of the organic solvent include methanol, ethanol, n-butanol, isopropanol, and
An organic solvent such as acetone, methyl ethyl ketone, n-hexane, or a mixed organic solvent thereof can be used. Furthermore, 0.1 to 0.1% of oxygen, hydrogen, carbon dioxide, carbon monoxide, nitrogen, nitrogen dioxide, nitric oxide, etc. in the reaction gas.
By containing 10% by volume, the physical properties such as hardness and density of the thin film layer can be controlled.

An amorphous metal oxide layer such as silicon oxide or titanium oxide can be preferably formed by the above method.

The optical film of the present invention is, for example, an optical film having an antireflection layer in which a low refractive index layer and a high refractive index layer are laminated, or an optical film having a conductive layer and an antistatic layer.

In the present invention, by providing a plurality of plasma discharge devices, a multilayer thin film can be continuously provided, and a multilayer laminate can be formed without unevenness of the thin film.

For example, when an optical film having an antireflection layer on a polyester film is produced, the refractive index is 1.
A high refractive index layer having a refractive index of 6 to 2.6 and a low refractive index layer having a refractive index of 1.3 to 1.5 can be continuously laminated on the surface of the polyester film to be efficiently manufactured.

As the low refractive index layer, a fluorine-containing compound layer formed by plasma discharge treatment of a gas containing a fluorine-containing organic compound, or mainly formed by plasma discharge treatment using an organosilicon compound such as alkoxysilane is used. A layer having silicon oxide is preferable, and as the high refractive index layer,
A metal oxide layer formed by plasma discharge treatment of a gas containing an organometallic compound, for example, a layer containing titanium oxide or zirconium oxide is preferable.

The present invention is not limited to these, and the layer structure is not limited to these. For example, the antifouling layer may be provided on the outermost surface by plasma discharge treatment in the presence of a fluorine-containing organic compound gas under atmospheric pressure or a pressure in the vicinity thereof. Alternatively, an antifouling layer may be provided by coating.

According to the present invention, a multilayer thin film can be laminated by the above method, and a uniform optical film can be obtained without unevenness of the film thickness of each layer.

The film thickness of a thin film such as a metal oxynitride layer was determined by making a cross section of the laminate and using a transmission electron microscope (Transmiss).
Ion Electroron Microscope:
Hereinafter, it can be determined by observing with TEM).

Specifically, the cross section was prepared by embedding the laminate together with the substrate in an epoxy embedding resin for electron microscope observation pretreatment, and using an ultramicrotome equipped with a diamond knife to a thickness of about 0. Make 1 μm ultrathin sections or use focused ion beam (Focused Ion Be)
It can be produced by focusing and scanning a Ga ion beam on the surface of the laminated body using an am: FIB) processing device and cutting out a thin section having a thickness of about 0.1 μm.

Observation by TEM shows a magnification of 50,000.
A bright field image is observed at 0 to 500,000 times, and the image is recorded on a film, an imaging plate, a CCD camera or the like. The acceleration voltage of TEM is 80 to 400 kV
Is preferred, and particularly preferred is 80 to 200 kV.

For details of the electron microscope observation technique and the sample preparation technique, see “Electron Microscopy Society of Japan Kanto Branch Edition / Medical / Biological Electron Microscopy” (Maruzen), “Electron Microscope Society of Japan Kanto Chapter Edition / Electronics” "Microscopic biological sample preparation method" (Maruzen), "Electron microscope Q &A" (Agne Jofusha)
Can be referred to respectively. A TEM image recorded on a suitable medium is one image at least 1024 pixels x 1024 pixels, preferably 2048 pixels x 2048 pixels.
It is preferable to decompose the image into pixels or more and perform image processing by a computer. For details of image processing technology, see "Tanaka Hiroshi
Image processing application technology (industrial research committee) "can be used as a reference, and the image processing program or device is not particularly limited as long as the above operation can be performed, but an example is an image manufactured by MEDIA CYBERNETICS (USA). Analysis software Image-Pro PLUS may be mentioned.

In order to perform image processing, it is preferable that the analog image recorded on the film is converted into a digital image by a scanner or the like, and shading correction, contrast / edge emphasis, etc. are performed as necessary. After that, a histogram is created, and a binarization process is performed to extract a portion corresponding to the laminate interface, and the width between the interfaces (Thickness
s) is measured. Similarly, at least 25 places,
Preferably, the average film thickness and its variation can be calculated from the values obtained at 50 or more locations.

As described above, the present invention can provide an optical film having a metal oxynitride layer having various functions.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an optical film in which the occurrence of cracks in the metal oxynitride layer is small and curl and curl are improved, and the optical film is repeatedly exposed under high temperature and high humidity conditions. The deterioration of the display quality due to the decrease in conductivity or the cloudiness was also improved.

The optical film of the present invention is particularly useful as a polarizing plate protective film, and a polarizing plate can be produced by a known method using this.

The polarizing plate having the optical film and the display device having the optical film were excellent in visibility and could provide excellent display performance even in a harsh environment.

In the optical film of the present invention, if necessary,
A clear hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, a conductive layer, a light diffusion layer, an easy-adhesion layer, an antifouling layer, and an electromagnetic wave shielding layer can be provided alone or in an appropriate combination.

The optical film of the present invention is preferably used as an antireflection film, an antistatic film, a conductive film, an electromagnetic wave shielding film, a protective film such as a polarizing plate, an optical compensation film, a polarizing plate, a plasma display front filter and the like.

The optical film of the present invention is a reflective type, transmissive type, semi-transmissive type liquid crystal display device or TN type, STN type.
Type, OCB type, HAN type, VA type, IPS type and the like are preferably used in liquid crystal display devices of various driving systems, and also preferably used in various display devices such as plasma displays, organic EL displays and inorganic EL displays.

[0205]

The present invention will be described in more detail with reference to the following examples, but the embodiments of the present invention are not limited thereto.

Example 1 [Synthesis of Polyester] (Polyester A) 0.1 part by mass of calcium acetate hydrate was added to 100 parts by mass of dimethyl terephthalate and 64 parts by mass of ethylene glycol, and transesterification reaction was carried out by a conventional method. It was In the obtained product, 39 parts by mass of ethylene glycol solution of 5-sodium sulfodi (β-hydroxyethyl) isophthalic acid (concentration 35% by mass) (7 mol% / total dicarboxylic acid component), polyethylene glycol (number average molecular weight) 3000) 5.8 parts by mass (5% by mass / generated polyester), antimony trioxide 0.05 parts by mass, and phosphoric acid trimethyl ester 0.13 parts by mass were added. Then, gradually raise the temperature and reduce the pressure to 280 ° C. and 40P.
Polymerization was carried out in a to obtain polyester A.

The intrinsic viscosity was determined according to the method shown below. As a result, the intrinsic viscosity was 0.50. The intrinsic viscosity was calculated by the following procedure using an Ubbelohde viscometer. Mass ratio is about 55:45 (flow time 42.0 ±
(Adjusted to 0.1 seconds) and phenol, 1,1,2,2-
The sample was melt | dissolved using the mixed solvent with tetrachloroethane, and the solution (temperature 20 degreeC) of concentration 0.2, 0.6, 1.0 (g / dl) was prepared. The specific viscosity (η _sp ) at each concentration (C) was obtained by an Ubbelohde viscometer, and the equation [η _sp / C] was extrapolated (C → 0) to zero concentration to obtain the intrinsic viscosity [η]. The unit of the intrinsic viscosity [η] is dl / g.

(Polyester B) 22 parts by mass of ethylene glycol solution of 5-sodium sulfodi (β-hydroxyethyl) isophthalic acid (concentration 35% by mass) (4 mol% / total dicarboxylic acid component), polyethylene glycol ( Number average molecular weight 3000) 12.2 parts by mass (1
Polyester B was obtained in the same manner as described above, except that the amount was changed to 0.5% by mass / generated polyester. The intrinsic viscosity measured in the same manner was 0.55.

(Polyester C) To 100 parts by mass of dimethyl terephthalate, 65 parts by mass of ethylene glycol, and 2 parts by mass of diethylene glycol, 0.05 part by mass of magnesium acetate hydrate was added as an ester exchange catalyst, and the transesterification reaction was carried out according to a conventional method. went. 0.05 parts by mass of antimony trioxide and 0.03 parts by mass of trimethyl phosphate were added to the obtained product. Then gradually raise the temperature,
Polymerization was carried out under reduced pressure at 280 ° C. and 80 Pa to obtain polyester C having an intrinsic viscosity of 0.65.

[Production of Base Film] (Base Film 1) 150 polyester pellets were prepared.
After vacuum-drying at 8 ° C. for 8 hours, it was melt-extruded at 285 ° C. by using an extruder, brought into close contact with a 30 ° C. cooling drum while being electrostatically applied, and cooled and solidified to obtain an unstretched sheet. This unstretched sheet was stretched 1.2 times in the machine direction at 85 ° C. using a roll-type machine. The temperature difference between the front and back surfaces was within 5 ° C.

The obtained uniaxially stretched film was stretched 4.5 times in the transverse direction at 95 ° C. using a tenter type transverse stretching machine.
Then, heat treatment is performed at 70 ° C. for 2 seconds, and further heat fixing is performed at the first heat setting zone 150 ° C. for 10 seconds.
Heat set at 0 ° C for 15 seconds, then at 5 ° C, relax 5% in the lateral (width) direction and wind.
A polyester film (base film 1) having a thickness of 00 mm and a thickness of 35 μm was produced. Immediately before winding, both ends were knurled with a height of 5 μm and a width of 1 cm.

(Substrate film 2) Polyester A pellets were vacuum dried at 150 ° C. for 8 hours, melt-extruded at 285 ° C. using an extruder, and adhered onto a cooling drum at 30 ° C. while electrostatically applying, It was cooled and solidified to obtain an unstretched sheet. The unstretched sheet was rolled using a roll-type longitudinal stretching machine to
It was stretched 4.0 times in the machine direction at 0 ° C. The temperature difference between the front and back is 5
It was within ℃.

The obtained uniaxially stretched film was stretched 1.2 times in the transverse direction at 100 ° C. using a tenter type transverse stretching machine. Then, heat treatment is performed at 70 ° C. for 2 seconds, heat setting is further performed at the first heat setting zone 150 ° C. for 10 seconds, heat setting is performed at the second heat setting zone 180 ° C. for 15 seconds, and then at 160 ° C. in the lateral (width) direction. Then, the film was subjected to a 2% relaxation treatment and wound up to form a polyester film (base film 2) having a lateral length of 1500 mm and a thickness of 35 μm.

(Substrate film 3) Pellets of polyester A and polyester C were mixed in a tumbler type mixer in a mass ratio of 3: 7, and vacuum dried at 150 ° C for 8 hours. Also, the polyester B pellets are 8 at 150 ° C.
Vacuum dried for an hour. The mixture of Polyester A and Polyester C and Polyester B are mixed in two extruders.
It was melt extruded at 5 ° C., extruded into a sheet using a multi-manifold die, brought into close contact with a cooling drum at 30 ° C. while being electrostatically applied, and cooled and solidified to obtain an unstretched sheet. At this time, the thickness ratio of each layer was set to 1: 1. This unstretched sheet was stretched 1.05 times in the machine direction at 95 ° C. using a roll-type machine. The temperature difference between the front and back surfaces was within 5 ° C.

The obtained uniaxially stretched film was stretched 4.0 times in the transverse direction at 105 ° C. using a tenter type transverse stretching machine. Then, heat treatment is performed at 70 ° C. for 2 seconds, heat setting is further performed at the first heat setting zone 150 ° C. for 10 seconds, heat setting is performed at the second heat setting zone 180 ° C. for 15 seconds, and then at 160 ° C. in the lateral (width) direction. Then, a polyester film (base film 3) having a length of 1500 mm in the lateral direction and a thickness of 30 μm was prepared.

(Substrate film 4) Polyester C pellets were vacuum dried at 150 ° C. for 8 hours, and then dried using an extruder.
Melt extrusion was carried out at 90 ° C., and it was brought into close contact with a cooling drum at 30 ° C. while applying static electricity and cooled to solidify to obtain an unstretched sheet.
This unstretched sheet is heated at 95 ° C. using a roll-type longitudinal stretching machine.
Was drawn 1.2 times in the machine direction. The temperature difference between the front and back surfaces was within 5 ° C.

The uniaxially stretched film thus obtained was stretched 4.5 times in the transverse direction at 105 ° C. using a tenter type transverse stretching machine. Then, heat treatment is performed at 70 ° C. for 2 seconds, heat setting is further performed at the first heat setting zone 150 ° C. for 10 seconds, heat setting is performed at the second heat setting zone 180 ° C. for 15 seconds, and then at 160 ° C. in the lateral (width) direction. Then, a polyester film (base film 4) having a lateral length of 1500 mm and a thickness of 30 μm was prepared by relaxing the film by 5% and winding.

Substrate film 1 obtained as described above
For 4 to 4, equilibrium water content, dimensional stability,
The moisture permeability was evaluated. The results are shown in Table 1.

<Equilibrium Moisture Content> 23 film samples were prepared.
After leaving it for 4 hours or more in a room whose humidity is controlled to 20 ° C and relative humidity of 20%, soak it in distilled water at 23 ° C for 24 hours, wipe off the water on the surface, and take a sample with a trace moisture meter (for example, Mitsubishi Chemical Water was dried and vaporized at a temperature of 150 ° C. using CA-20 type manufactured by K.K., and then quantified by the Karl Fischer method.

<Dimensional Stability> Film is 80 ° C., 90%
Before and after the treatment with RH for 1000 hours, the dimensional change rate was obtained and evaluated in the direction in which the in-plane refractive index of the film was the maximum. The contraction direction was minus and the extension direction was +.

<Moisture Permeability> The moisture permeability at a temperature of 25 ° C. and a humidity of 90% RH was determined according to JIS Z0208.

[0222]

[Table 1]

[Production of Optical Film] Optical film 1 was formed with a tin oxide layer having a thickness of 0.1 μm on the base film by atmospheric pressure plasma treatment.

The apparatus shown in FIG. 2 was used for the atmospheric pressure plasma discharge treatment. As the roll electrode, a stainless steel jacket roll base material having a cooling function by circulating silicon oil inside was used.

Alumina was added to this by ceramic spraying.
mm coating, and then a solution of tetramethoxysilane diluted with ethyl acetate is applied and dried, then cured by ultraviolet irradiation and sealed to perform a sealing treatment, and a roll electrode having a dielectric of Rmax, 1 μm is manufactured and grounded (grounded). did.

On the other hand, as a counter electrode, a hollow stainless steel pipe was coated with the same dielectric as the above under the same conditions to form a facing electrode group. The plasma discharge processing device uses a JEOL high-frequency power supply with a continuous frequency of 2
The frequency was set to MHz and a power of ² W / cm ² was supplied. However, the roll electrode was rotated in synchronization with the conveyance of the polyester film using a drive. The surface temperature of the roll electrode is 7
It was set to 0 ° C.

The electrode gap was 1.6 mm, the reaction gas pressure was +1 kPa relative to the atmospheric pressure, and the reaction gas temperature was 85 ° C. to form a metal oxide layer having a film thickness of 0.1 μm. The composition of the reaction gas used for the plasma discharge treatment is described below.

(Reaction Gas for Forming Tin Oxide Layer) Inert gas (helium) 99.4% by volume Reaction gas (oxygen gas) 0.3% by volume Reaction gas (tetrabutyltin vapor) 0.3% by volume Optical obtained Films 1 to 4 were evaluated for cracks, curls, cloudiness, conductivity, and adhesiveness. The conductivity was evaluated by the change in surface resistivity. The results are shown in Table 2.

<Crack> 80 ± 3 of optical film sample
C., 90 ± 2% RH for 12 hours, 23 ± 2
After the sample was left standing at 55 ° C. and 55 ± 5% RH for 12 hours, the sample was observed for cracks with an optical microscope and evaluated according to the following criteria.

⊚: Almost no cracks were found ◯: Short cracks were found Δ: Many short cracks were found on the entire surface ×: Innumerable cracks were found on the entire surface <Curl> Film wound into a roll 23 ± 2
The sample was cut into 2 mm in the longitudinal direction and 50 mm in the width direction, and the sample piece was cut into 2 pieces.
After conditioning the humidity at 3 ± 2 ° C. and 55% RH for 24 hours, a curvature scale was used to confirm the radius of curvature (1 / m) having a curve that matches the sample, and the radius of curvature was determined to be the curl of the sample. Value.

⊚: Curl value less than 10 ◯: Curl value 10 to less than 20 Δ: Curl value 20 to less than 25 x: Curl value 25 or more <White turbidity> Each optical film in a high temperature and high humidity atmosphere of 80 ° C. and 90% RH. After being treated for 6 hours, it was left in an atmosphere of 23 ° C. and 55% RH for 18 hours. After repeating this treatment 30 times in total, the state of cloudiness was visually observed on the metal oxide layer side. The evaluation is 1 when no cloudiness is observed.
5 was used for the case where significant white turbidity was generated, and the state of the rank between them was set to 2 to 4, and a 5-level evaluation was performed. It is considered that the cloudiness was due to the inclusion of fine cracks.

<Change in surface resistivity> Change in surface resistivity after repeated high temperature and high humidity treatment: under the conditions of 80 ° C. and 90% RH,
After exposure for 6 hours, the humidity was adjusted to 23 ° C. and 30% RH for 18 hours. Similarly, after repeating the high temperature and high humidity treatment 10 times,
After conditioning the humidity for 6 hours under the conditions of 23 ° C. and 30% RH, measure the surface specific resistance value of the metal oxide layer surface with an insulation resistance measuring instrument (VE ・ 30 type manufactured by Kawaguchi Electric Co., Ltd.) under the same conditions. Then, the evaluation was made according to the following criteria, and the results are shown in Table 2.

⊚: Surface specific resistance value was less than 10 ¹⁰ Ω / cm ² and hardly changed. ○: Surface specific resistance value was slightly increased, but 10 ¹¹ Ω / c.
No problem at m ² level Δ: Surface resistivity increased but less than 10 ¹² Ω / cm ² , no problem x: Surface resistivity of 10 ¹² Ω / cm ² or more, 5 × 10 ¹²
Increased to less than Ω / cm ² XX: The surface resistivity increased significantly to 5 × 10 ¹² Ω / cm ² or more.

As is clear from Table 2, the optical film of the present invention showed a good value with little change in surface specific resistance due to repeated high temperature and high humidity treatment, but the comparative optical film showed an increase in surface specific resistance value. As a result, a decrease in antistatic property was observed.

<Adhesiveness> A cross-cut test was carried out in accordance with JIS-K-5400. Specifically, 11 cuts were made vertically and horizontally at 1 mm intervals on the coated surface to make 100 1 mm square grids. Cellophane tape was attached on this, and it was quickly peeled off at an angle of 90 degrees, and evaluated by the number of crosses left without peeling.

◎: 100 Adhesiveness is excellent and excellent ○: 95 to 99 Peeling is slightly but there is no problem in practical use Δ: 80 to 94 Peeling is noticeable and there is a problem in practical use ×: Less than 80 Peeling is remarkable in practical use I can not use it.

[0237]

[Table 2]

It was confirmed that the optical film of the present invention had few cracks, reduced curl, excellent adhesiveness, and stable conductivity.

Example 2 A clear hard coat layer (CHC) or an antiglare layer (AG) was formed on the substrate film and the optical film formed in Example 1.
Was applied, and the following antireflection layer was formed thereon by using the plasma processing apparatus used in Example 1. The base film and the optical film were applied after the wettability was improved by corona discharge treatment before forming the following coating layer. In the optical film, a clear hard coat layer or an antiglare layer was formed on the tin oxide layer.

Anti-glare layer (AG) UV-curable acrylic urethane resin 100 parts (Unidec 17-806 (manufactured by Dainippon Ink and Chemicals, Inc.)) Spherical crosslinked polystyrene fine particles having an average particle diameter of 3.5 μm 5 parts Average particle diameter 16 nm Synthetic silica fine particles of 7 parts Coronate L (polyisocyanate compound: manufactured by Nippon Polyurethane Co., Ltd.) 1 part Photopolymerization initiator (IRGACURE 184 manufactured by Ciba Geigy) 3 parts The above components are mixed with a solvent (ethyl acetate) by a homogenizer. A homogeneous dispersion having a volatile content of 60% was prepared.

The base film was wire-bar coated with this and dried at 90 ° C. for 2 minutes, and then 130 mJ / cm ²
Was irradiated with the ultraviolet rays and cured to form an antiglare layer 1 having a thickness of 3 μm.

Clear hard coat layer (CHC) Dipentaerythritol hexaacrylate monomer 60 parts Dipentaerythritol hexaacrylate dimer 20 parts Dipentaerythritol hexaacrylate trimer or more components 20 parts Photopolymerization initiator (IRGACURE 184 Ciba Geigy) 4 parts Ethyl acetate 50 parts Methyl ethyl ketone 50 parts Isopropyl alcohol 50 parts This is coated on a base film with a wire bar, dried at 90 ° C. for 2 minutes, and then irradiated with UV rays of 130 mJ / cm ² to cure it. A clear hard coat layer (CHC) having a film thickness of 3 μm was formed.

<Formation of Metal Oxide Layer> On the ultraviolet curable resin layer (AG or CHC) provided on the base film, the atmospheric pressure plasma treatment apparatus used in Example 1 was used to perform the first oxidation. Titanium layer (refractive index 2.15, average film thickness 15
nm), the first silicon oxide layer (refractive index 1.46, average film thickness 3
3 nm), a second titanium oxide layer (refractive index 2.15, average film thickness 119 nm), and a second silicon oxide layer (refractive index 1.46, average film thickness 86 nm) were sequentially formed. The surface of the second silicon oxide layer was surface-treated with the reaction gas 2 for forming a silicon oxide layer described below.

As the power source of the plasma discharge treatment apparatus, a high frequency power source manufactured by Pearl Industrial Co., Ltd. was used, and the continuous frequency was 2 MHz.
Electric power of ² W / cm ² was supplied to the discharge electrode. The roll electrode was rotated using a drive in synchronization with the conveyance of the polyester film. The electrode gap was 1.4 mm, the pressure of the reaction gas was atmospheric pressure + 1 kPa, and the temperature of the reaction gas was 8 mm.
It was performed at 0 ° C. The composition of the reaction gas used for the plasma discharge treatment is described below.

[0245]   (Reaction gas for forming titanium oxide layer (high refractive index layer))   Inert gas (helium) 99.4% by volume   Reactive gas (hydrogen gas) 0.3% by volume   Reaction gas (tetraisopropoxy titanium vapor) 0.3% by volume   (Reaction Gas for Forming Silicon Oxide Layer (Low Refractive Index Layer))   Inert gas (helium) 99.4% by volume   Reactive gas (oxygen gas) 0.3% by volume   Reaction gas (tetraethoxysilane vapor) 0.3% by volume   (Reaction gas 2 for forming silicon oxide layer (low refractive index layer))   Inert gas (helium) 99.8% by volume   Reaction gas (CF4) 0.2% by volume Table 3 shows the evaluation results of the obtained antireflection film.

The optical film of the present invention is suitable for sticking to a flat surface portion such as the forefront of a display device, because cracks are less likely to occur, curl is small, and curl is easily eliminated. On the other hand, the comparative optical film has a problem that cracks are likely to occur, curl is large, and curl is difficult to be eliminated, so that wrinkles are likely to occur during attachment.

<Measurement of Average Reflectance> A spectrophotometer (U-4000 manufactured by Hitachi, Ltd.) is used to roughen the surface on the side where the antireflection layer is not provided, and then light is applied using a black spray. Absorption treatment was performed to prevent reflection of light on the back surface, each reflectance at 450 to 650 nm was measured under the condition of specular reflection of 5 degrees, and the average reflectance was obtained.

[0248]

[Table 3]

Example 3 [Production of Polarizer] A polyvinyl alcohol film having a thickness of 120 μm was immersed in an aqueous solution containing 1 part by mass of iodine, 2 parts by mass of potassium iodide and 4 parts by mass of boric acid, and stretched 4 times at 50 ° C. Then, a polarizer was produced.

[Production of Polarizing Plate and Display] On the back surface side of the surface having the antireflection layer of the antireflection film of Example 2,
Kasuga Denki Co., Ltd. corona discharge treatment device (HFS-20
Using 2), the easy adhesion treatment was performed under the condition of 12 W · min / m ² . Similarly, one surface of the polyester film (base film) used for each antireflection film was subjected to corona treatment.

A completely saponified polyvinyl alcohol 5% aqueous solution was used as an adhesive on both sides of the above-prepared polarizer so that the side of the antireflection film and the polyester film which had been subjected to the easy adhesion treatment would be the polarizer side. Pasted,
A polarizing plate was produced. At this time, the antireflection film was laminated so that the maximum direction of the refractive index in the film plane was parallel to the polarization axis of the polarizer.

Next, a commercially available liquid crystal display panel (NEC color liquid crystal display MultiSync LCD1
525J: Model name LA-1529HM), the polarizing plate on the outermost surface was carefully peeled off, and the polarizing plates prepared as described above with their polarization directions aligned were attached thereto.

When the produced liquid crystal display panel was observed with a magnifying glass, no increase in cracks in the antireflection layer was observed in the liquid crystal display panel using the polarizing plate of the present invention. Occurrence of cracks was observed in the liquid crystal display panel used. Dust was more likely to adhere to the comparative polarizing plate.

[0254]

INDUSTRIAL APPLICABILITY In a conductive film and an antireflection film in which a metal oxynitride layer is provided on a polyester film as an optical film used in various display devices, cracks are remarkably reduced, curling is improved, and conductivity is improved. It was possible to provide a film with less deterioration.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an example of a plasma discharge treatment apparatus having a rotating electrode and a fixed electrode useful for forming a metal oxynitride thin film layer of the present invention.

[Explanation of symbols]

F polyester film G reaction gas G'exhaust gas 10A, 10B, 110 rotating electrodes 11A, 11B, 11C, 11D U-turn roll 20, 21 Guide roll 30 Reaction gas supply unit 40,140 Gas exhaust port 50, 150 Discharge part 80, 180 power supply 81, 82, 181, 182 Voltage supply means 111 fixed electrode 120, 121 Guide roll 122, 123 nip roll 124, 125 partition plates 130 Air supply pipe 131 Reaction gas generator 190 Plasma discharge treatment vessel

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C23C 16/30 C23C 16/30 G02B 1/10 C08L 67:02 1/11 G02B 1/10 A // C08L 67:02 Z F-term (reference) 2H049 BA02 BA24 BB23 BB65 BB67 BC10 BC22 2K009 AA02 CC03 CC34 DD04 EE03 4F006 AA35 AB74 BA07 BA14 CA08 DA01 4F100 AA01A AA12B AA17B AA33B AK42A AK42K BA02 EH66B EJ61B GB41 JG01 JN06 JN10 4K030 AA11 BA35 BA44 BA45 BA46 BB05 CA07 CA12 FA03 JA09 KA16 LA18

Claims (13)

[Claims] 1. A metal oxynitride on a substrate film having a layer of a polyester resin produced by a reaction of at least an aromatic dicarboxylic acid and glycol and having an equilibrium water content of 1 to 5%, either directly or through another layer. An optical film comprising a physical layer. 2. A film thickness of 5 to 40 μm and a dimensional stability of ± 0.
It is 5% or less, The optical film of Claim 1 characterized by the above-mentioned. 3. The polyester resin has a group selected from sulfonic acid and salts thereof.
Or the optical film according to item 2. 4. The optical film according to claim 3, wherein the polyester resin has a sulfur element content of 0.15 to 2 mass%. 5. A polyester resin, wherein the aromatic dicarboxylic acid has a group selected from 1 to 10 mol% of sulfonic acid and salts thereof based on the total aromatic dicarboxylic acid, or 1 to 10 mol% of sulfonic acid based on the total glycol, and The optical film according to claim 3 or 4, which is produced using a glycol having a group selected from the salt thereof. 6. The polyester resin is produced by using 1 to 10 mol% of an aromatic dicarboxylic acid having a group selected from sulfonic acids and salts thereof based on the total aromatic dicarboxylic acid. Alternatively, the optical film according to item 4. 7. The polyester resin contains polyalkylene glycol in an amount of 0.1 relative to the total amount of polyester in the reaction product.
It is manufactured using 10 to 10% by mass.
The optical film according to any one of items 1 to 6. 8. The main component of the polyester resin is polyethylene terephthalate, which is characterized in that
The optical film according to any one of 1. 9. The optical element according to claim 7, wherein a metal oxynitride layer is provided directly or via another layer on a long film continuously formed by melt extrusion. the film. 10. An optical system characterized in that a metal oxynitride layer is provided by atmospheric pressure plasma CVD directly or through another layer on a substrate having a polyester resin layer having an equilibrium water content of 1 to 5%. the film. 11. An atmospheric pressure plasma of a metal oxynitride layer directly or through another layer on a base film formed by stretching a film having a polyester resin having a group selected from sulfonic acid or a salt thereof. A method for producing an optical film, which is characterized by being formed by CVD. 12. A polarizing plate comprising the optical film according to any one of claims 1 to 10. 13. A display device using the polarizing plate according to claim 12.