JP2005070744A - Optical film, method for manufacturing optical film, polarizing plate, and display apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wide and thin optical film having sufficient pencil hardness without causing peeling, cracks or scratches even when the optical film has a layered structure, to provide a method for manufacturing the film, and to provide a polarizing plate using the film, and a liquid crystal display having excellent visibility. <P>SOLUTION: The method for manufacturing an optical film having a hard coat layer disposed on a cellulose ester film substrate is characterized in that: at least one layer of intermediate layer and a hard coat layer are applied on a prescribed cellulose ester film substrate; the coating composition for forming the intermediate layer contains at least one kind of solvent which can swell or dissolve the substrate; the proportion of the solvent which can swell or dissolve the substrate is 20 to 95 vol% of the entire solvent of the coating composition; and the coating composition for formation of the intermediate layer is applied to form 5 to 60 μm wet film thickness per one layer of the intermediate layer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to an optical film used for optical applications and a method for producing the same, and particularly to an antireflection film used for a display device such as a liquid crystal display device or an organic EL display, a plasma display, a field emission display, and the production thereof. The present invention relates to a useful optical film and a method for producing the same.

  A transparent resin film used for optical applications such as a polarizing plate protective film for liquid crystal displays, a circular polarizing plate protective film used for organic EL displays, and an elliptical polarizing plate has a transparent resin layer in order to have various functions. It is painted. For example, an antistatic layer for providing an antistatic function, a hard coat layer for improving surface hardness, an undercoat layer for improving film adhesion, an anti-curl layer for preventing curling, etc. . When such a transparent resin layer is applied to the transparent resin film, particularly when a hard coat layer or a laminated structure in which an antireflection layer is further applied thereon is taken, cracks are generated and various processes are performed. Occurrence of scratches, etc. was seen and sometimes became a problem. In particular, when a polarizing plate is produced using these optical films, there is a problem in that productivity is remarkably impaired due to failure such as peeling or cracking of the hard coat layer during subsequent cutting and punching.

  In order to have various functions, fine particles may be added to the lower layer. For example, when the lower layer is an antistatic layer, conductive fine particles will be added. Adhesion between the added fine particles and the lower layer binder may be a problem, and the peeling and cracking may be increased.

Regarding the improvement of problems caused by these adhesions, a technology comprising a transparent resin having two or more transparent resin layers on a transparent resin film, and the lower binder mainly having a weight average molecular weight of 20,000 to 400,000 In addition, a technique (for example, see Patent Documents 1 and 2) in which a coating composition having a water content of 5% by mass or less having a resin and a solvent is applied on a film substrate and a resin layer is provided is disclosed, and each effect is recognized. However, the effect is insufficient for a thin film and a wide optical film corresponding to the recent increase in size and thickness of liquid crystal display devices. Further, there is no suggestion regarding improvement of peeling, cracking, scratches and the like.
JP 2001-83327 A JP 2001-183528 A

  Therefore, the object of the present invention is excellent in adhesiveness with the substrate, there is no occurrence of peeling, cracking, scratching, etc. even in an optical film with a laminated structure, and a wide width with sufficient pencil hardness, excellent flatness, An object of the present invention is to provide a thin film optical film, a production method thereof, a polarizing plate excellent in hardness and processability using the same, and a liquid crystal display device excellent in visibility.

  The above object of the present invention is achieved by the following configurations.

(Claim 1)
In the method for producing an optical film in which a hard coat layer is provided on a cellulose ester film substrate, the cellulose ester film substrate contains an ultraviolet absorber and two or more plasticizers, and has a total acyl group substitution degree of 2.6. After casting a solution containing a cellulose ester having a value of ˜2.9, number average molecular weight (Mn) 80000-200000, weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.4 to 3.0, A method of producing an optical film by coating at least one intermediate layer on the cellulose ester film substrate, and then coating a hard coat layer on the cellulose ester film substrate, The coating composition for providing the intermediate layer contains at least one solvent that can swell or dissolve the substrate, and the coating composition of the solvent that can swell or dissolve the substrate The proportion of the total agent is 20 to 95% by volume, and the coating composition for providing the intermediate layer is applied so that the wet film thickness per layer of the intermediate layer is 5 to 60 μm. A method for producing an optical film.

(Claim 2)
The method for producing an optical film according to claim 1, wherein the intermediate layer has at least one binder, and the binder contains an acrylic resin or a cellulose ester.

(Claim 3)
Two or more kinds of plasticizers contained in the cellulose ester film substrate are selected from plasticizers other than phosphate ester plasticizers, and the content of phosphate ester plasticizers is less than 1% by mass. The method for producing an optical film according to claim 1, wherein the optical film is a film.

(Claim 4)
The method for producing an optical film according to claim 1, wherein at least one of the plasticizers is a polyhydric alcohol ester plasticizer.

(Claim 5)
An optical film produced by the method according to claim 1.

(Claim 6)
An optical film having at least one intermediate layer and a hard coat layer on a cellulose ester film substrate, wherein the cellulose ester film substrate contains an ultraviolet absorber and two or more plasticizers, and is substituted with a total acyl group A solution containing a cellulose ester having a degree of 2.6 to 2.9, a number average molecular weight (Mn) of 80000 to 200000, and a weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.4 to 3.0. The intermediate layer coating composition is produced by biaxial stretching after casting, and the intermediate layer contains a solvent capable of swelling or dissolving the cellulose ester film substrate in an amount of 20 to 95% by volume based on the total solvent. An optical film characterized by having a hard coat layer on an intermediate layer formed by coating so as to have a wet film thickness of 5 to 60 μm.

(Claim 7)
The optical film according to claim 6, wherein the intermediate layer has at least one binder.

(Claim 8)
The optical film according to claim 7, wherein the binder contains an acrylic resin or a cellulose ester.

(Claim 9)
The optical film according to claim 8, wherein the cellulose ester used for the binder is a cellulose ester having a total acyl group substitution degree of 0.1 or more smaller than the total acyl group substitution degree of the cellulose ester film base material.

(Claim 10)
The intermediate layer contains at least one binder and fine particles having an average particle diameter of 0.01 to 3 μm, and the content of the fine particles is 5 to 90% by volume of the total solid content of the intermediate layer. The optical film according to any one of claims 6 to 9.

(Claim 11)
Two or more kinds of plasticizers contained in the cellulose ester film substrate are selected from plasticizers other than phosphate ester plasticizers, and the content of phosphate ester plasticizers is less than 1% by mass. The optical film according to claim 6, wherein the optical film is a film.

(Claim 12)
The optical film according to any one of claims 6 to 11, wherein at least one of the plasticizers is a polyhydric alcohol ester plasticizer.

(Claim 13)
The optical film according to claim 6, wherein an antireflection layer is provided on the hard coat layer.

(Claim 14)
14. The optical film according to claim 6, wherein a width of the cellulose ester film substrate is in a range of 1.4 m to 4 m.

(Claim 15)
A polarizing plate comprising the optical film according to any one of claims 6 to 14 provided on at least one surface.

(Claim 16)
A display device comprising the polarizing plate according to claim 15.

  According to the present invention, it is excellent in adhesiveness with a base material, and even with an optical film having a laminated structure, there is no occurrence of peeling, cracking, scratching, etc. A film, a manufacturing method thereof, a polarizing plate using the film, and a liquid crystal display device excellent in visibility can be provided.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

  The present invention relates to a method for producing an optical film in which a hard coat layer is provided on a cellulose ester film substrate, wherein the cellulose ester film substrate contains an ultraviolet absorber and two or more plasticizers, and is substituted with a total acyl group. A solution containing a cellulose ester having a degree of 2.6 to 2.9, a number average molecular weight (Mn) of 80000 to 200000, and a weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.4 to 3.0. Is produced by biaxial stretching after casting, and after coating at least one intermediate layer on the cellulose ester film substrate, a hard coat layer is coated to produce an optical film. The coating composition for providing the intermediate layer comprises a solvent capable of swelling or dissolving at least one substrate, and the solvent composition capable of swelling or dissolving the substrate. The proportion of the total amount of the cloth composition solvent is 20 to 95% by volume, and the coating composition for providing the intermediate layer is a wet film thickness per layer of the intermediate layer (the solvent immediately after the coating composition is applied). The film is coated so that the film thickness is 5 to 60 μm.

  That is, as a result of intensive studies on the above problems, the present inventors have wetted a specific intermediate layer coating composition containing a solvent capable of swelling or dissolving at least one type of base material on a specific cellulose ester film base material. By coating so that the film thickness is 5 to 60 μm, and further by coating a hard coat layer, it is excellent in adhesion between the substrate and the interlayer, and excellent in flatness without occurrence of peeling, cracking, scratches, etc. The present inventors have found that an optical film can be obtained and have reached the present invention.

  Hereinafter, the present invention will be described in detail.

<Intermediate layer>
When at least one or more intermediate layers and a hard coat layer are coated on the cellulose ester film substrate, there is a problem that the adhesion of the coating layer is deteriorated and peeling or cracking occurs. As a part that deteriorates the adhesion, the adhesion between the lower layer and the upper layer, the adhesion between the lower layer and the transparent resin film as the base material, and the adhesion between the lower layer binder and the fine particles when fine particles are added to the lower layer It became clear that Therefore, as a result of intensive studies to solve this problem, the coating composition for providing the intermediate layer contains at least one solvent that can swell or dissolve the substrate, and swells or dissolves the substrate. The proportion of the solvent that can be applied to the entire coating composition solvent is 20 to 95% by volume, and the coating composition for providing the intermediate layer is adjusted so that the wet film thickness per layer of the intermediate layer is 5 to 60 μm. By coating, it was found that adhesion was improved and problems such as peeling, cracking and scratches were improved. Surprisingly, interference unevenness caused by interference between light reflected from the surface of the hard coat layer and light reflected from the interface between the hard coat layer and the substrate due to the difference in the refractive index of the substrate and the refractive index of the hard coat layer ( (Interference fringe pattern) was also improved.

  An intermediate | middle layer here is formed by coating the coating composition containing a solvent on the cellulose-ester film used as a base material. The coating composition may be a solvent alone, and more preferably contains a binder. In the case of only the solvent, the portion where the surface of the base material is modified by the penetration of the solvent into the base material becomes the intermediate layer.

  The binder used for the intermediate layer is preferably a thermoplastic resin, and is coated in a state dissolved in the solvent according to the present invention described later. Examples of the resin used here include cellulose derivatives such as cellulose diacetate, cellulose triacetate, cellulose acetate butyrate, cellulose acetate phthalate, cellulose acetate propionate, and cellulose nitrate, polyvinyl acetate, polystyrene, polycarbonate, and polybutylene. Polyesters such as terephthalate or copolybutylene tele / isophthalate, polyvinyl alcohol derivatives such as polyvinyl alcohol, polyvinyl formal, polyvinyl acetal, polyvinyl butyral, polyvinyl benzal, norbornene resin polymers, polymethyl methacrylate, (meth) acrylic Acrylic resins such as copolymers containing methyl acid can be used, but are not limited to these. Not.

  Of these, cellulose derivatives or acrylic resins are particularly preferably used.

  Examples of the cellulose derivative include those described above, and the cellulose ester is preferably a cellulose ester in which the total acyl group substitution degree is 0.1 or more smaller than the total acyl group substitution degree of the cellulose ester film substrate. The present inventors have found that the effect of the present invention is further improved by selecting a cellulose ester having a total acyl group substitution degree of 0.1 or more smaller than the acyl group substitution degree of the substrate. The reason for this effect is not clear, but it is presumed that the hydroxyl group remaining in the cellulose ester has some influence on the plasticizer eluted from the base material and suppresses the adverse effect on the upper layer. Although there is no restriction | limiting in particular as a cellulose derivative, Preferably it is a cellulose ester of total acyl group substitution degree 2.0-2.7, and a cellulose ester of 2.0-2.6 is especially preferable. Among the cellulose esters, cellulose diacetate, cellulose acetate propionate and the like whose total acyl substitution degree satisfies the above conditions are preferable. A method for producing a cellulose ester and a method for measuring the total acyl group substitution degree will be described later.

  As the acrylic resin, an acrylic resin having a weight average molecular weight of 1,000,000 or less can be preferably used. In particular, the resin used here is preferably a thermoplastic resin, and a resin having a glass transition point of 110 ° C. or lower, more preferably 90 ° C. or lower is used. The resin used here is preferably the above-described resin.

  Further, a thermoplastic resin having a glass transition point of 110 ° C. or less, more preferably 30 to 90 ° C. is preferably used.

  As the thermoplastic acrylic resin, for example, various types having a molecular weight of tens of thousands to hundreds of thousands and a glass transition point of 20 to 105 ° C. are commercially available, and preferable ones can be selected.

  For example, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M4003, M-4005, M-4006, M-4202, M-5000, M-5001, M-4501 (Negami) Manufactured by Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR-79, BR-80, BR- 82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105, BR-106, Acrylic and methacrylic monomers such as BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118 (Mitsubishi Rayon Co., Ltd.) Various homopolymers and copolymers were prepared as charge are commercially available, can also be suitably selecting a preferred resin from the.

  The glass transition point can be determined by the method described in JIS-K7121.

  The resin used here is preferably 60% by mass or more, more preferably 80% by mass or more of the entire binder used in the intermediate layer, and an actinic ray curable resin or a thermosetting resin is blended as necessary. You can also

  The coating composition for an intermediate layer according to the present invention contains a solvent that can swell or dissolve the substrate, and the ratio of the solvent that can swell or dissolve the substrate to the entire coating composition solvent is 20 to 95% by volume. It is a range, More preferably, it is the range of 30-80 volume%.

  Solvents that can be used as the coating composition of the present invention and that can swell or dissolve the substrate include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl oxide, methyl n-amyl ketone, cyclohexanone, diacetone alcohol, diisobutyl ketone, and methylcyclohexanone. Ketones such as methyl acetate, ethyl acetate, ethyl lactate, butyl lactate, ethyl benzoate, methyl acetoacetate, etc., ethers such as dioxolane, dioxane, methyl cellosolve, methyl carbitol, methyl cellosolve acetate, cellosolve acetate Such as polyhydric alcohol esters such as tetrahydrofuran, furfural and the like, acids such as glacial acetic acid, halogen hydrocarbons such as methylene chloride, ethylene dichloride and tetrachloroethane, Tromethane, nitroethane, pyridine, dimethylformamide, nitrogen compounds such as nitrobenzene, sulfonic acids such as dimethyl sulfoxide and the like are suitably used. In consideration of drying after coating, a solvent that easily volatilizes is preferable, and a solvent having a boiling point of 200 ° C. or lower is preferable.

  In the present invention, a solvent that does not swell or dissolve the substrate can be mixed and used in the range of 5 to 80% by volume with the above solvent. For example, alcohols such as methanol, ethanol, propanol, n-butanol, 2-butanol, tert-butanol, glycol ethers (propylene glycol mono (C1-C4) alkyl ether (specifically, propylene glycol monomethyl ether (PGME), Propylene glycol monoethyl ether, propylene glycol mono n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, etc.), propylene glycol mono (C1-C4) alkyl ether ester (propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether) Acetate)), water, and other solvents. Although not particularly limited to these, a solvent in which these are appropriately mixed is preferably used.

  Examples of the optical film for forming one or more intermediate layers on the cellulose ester film substrate of the present invention include, but are not particularly limited to, the following examples.

Cellulose ester film / Anti-blocking layer (intermediate layer) / Clear hard coat layer Cellulose ester film / Antistatic layer (intermediate layer) / Clear hard coat layer Cellulose ester film / Light diffusion layer (intermediate layer) / Clear hard coat layer Cellulose ester Film / UV absorbing layer (intermediate layer) / clear hard coat layer Clear hard coat layer / antistatic layer (intermediate layer) / cellulose ester film / anti-curl layer / anti-blocking layer Clear hard coat layer / undercoat layer (intermediate layer) / Cellulose ester film / anti-curl layer / anti-blocking layer clear hard coat layer / cellulose ester film / antistatic layer (intermediate layer) / easi-adhesion layer / anti-blocking layer The intermediate layer of the present invention may contain fine particles. The average particle size of the fine particles was 0.01 to 3 μm, and it was revealed that the adhesion was not lowered even when fine particles were added when the total solid content contained in the intermediate layer was 5 to 90% by volume. The average particle diameter of the fine particles preferably includes particles having a primary particle diameter of 0.01 to 3 μm, and particularly includes particles having a primary particle diameter or a secondary particle diameter of 0.05 to 3 μm in which they are aggregated. It is preferable. The shape of the particles is not particularly limited, such as a spherical shape, a needle shape, a flat plate shape, a rice grain shape, an indefinite shape, or a rod shape.

  The fine particles that can be used in the intermediate layer are, as examples of inorganic compounds, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate And aluminum silicate, magnesium silicate and calcium phosphate. Those containing silicon are preferable in terms of low turbidity, and silicon oxide is particularly preferable.

  Examples of silicon oxide include Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above, manufactured by Nippon Aerosil Co., Ltd.), methanol silica sol, IPA-ST, IPA-ST-UP, Under the trade names of IPA-ST-ZL, EG-ST, NPC-ST-30, DMAC-ST, MEK-ST, MIBK-ST, XBA-ST, PMA-ST (manufactured by Nissan Chemical Industries, Ltd.) It is commercially available and can be used.

  As examples of zirconium oxide, Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.

Examples of organic fine particles include polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, polymethyl methacrylate crosslinked particles, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin Examples thereof include powder, melamine resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, and polyfluorinated ethylene resin powder. In particular, polystyrene resin powder and polymethyl methacrylate resin powder are preferable. Examples of polystyrene resin powder are SX-130H and SX-200H (above, manufactured by Soken Chemical Co., Ltd.), and examples of polymethyl methacrylate resin powder are MX150 and MX300. (As mentioned above, manufactured by Soken Chemical Co., Ltd.), an example of polymethyl methacrylate crosslinked particles is commercially available under the trade name of MS-300K (manufactured by Soken Chemical Co., Ltd.), and an intermediate layer that can be used is blocking. When it is a prevention layer, it is preferable that it is 0.05-1 micrometer as an average particle diameter of microparticles | fine-particles, 5-80 mass% is preferable with respect to a binder, and it is more preferable that it is 5-20 mass%. The dynamic friction coefficient of the anti-blocking layer is preferably 0.9 or less, particularly preferably 0.1 to 0.9.

  The intermediate layer of the present invention can be an antistatic layer.

  For example, when the intermediate layer is an antistatic layer, a method for improving adhesion even when conductive fine particles are added is provided. That is, when the average particle size of the fine particles is 0.05 to 3 μm and the content is 5 to 90% by volume of the total solids contained in the intermediate layer, it is clear that the adhesion does not decrease even when conductive fine particles are added. It became.

  That is, in the present invention, it is also a preferred embodiment to provide an antistatic layer on a transparent cellulose ester film.

  The antistatic processing is to impart a function of preventing the cellulose ester film from being charged when the transparent cellulose ester film is handled. Specifically, it contains an ionic conductive substance or conductive fine particles. This is done by providing a layer. Here, the ion conductive substance is a substance that shows electric conductivity and contains ions that are carriers for carrying electricity, and examples include ionic polymer compounds.

Examples of the ionic polymer compound include anionic polymer compounds such as those described in JP-B-49-23828, JP-A-49-23827, and JP-A-47-28937, JP-B-55-734, and JP-A-50-54672. Ionene type polymer having a dissociating group in the main chain, as shown in JP-B-59-14735, JP-B-57-18175, JP-B-57-18176, 57-56059, etc. No. 57-15376, No. 53-45231, No. 55-145783, No. 55-65950, No. 55-67746, No. 57-11342, No. 57-19735, No. 58-56858. No., JP-A 61-27853, 62-9346, and a cationic pendant type having a cationic dissociation group in the side chain Rimmer, etc. can be mentioned. Examples of conductive fine particles include conductive metal oxides. Examples of metal oxides are preferably ZnO, TiO ₂ , SnO ₂ , Al ₂ O ₂ , In ₂ O ₃ , SiO ₂ , MgO, BaO, MoO ₂ , V ₂ O ₅ , or a composite oxide thereof. In particular, ZnO, TiO ₂ and SnO ₂ are preferred. Examples of containing different atoms include, for example, addition of Al and In to ZnO, addition of Nb and Ta to TiO ₂ , and addition of Sb, Nb and halogen elements to SnO ₂ . Addition is effective. The amount of these different atoms added is preferably in the range of 0.01 mol% to 25 mol%, but is particularly preferably in the range of 0.1 mol% to 15 mol%.

Further, the volume resistivity of these conductive metal oxide powders is 10 ⁷ Ωcm or less, particularly 10 ⁵ Ωcm or less, and the average particle size is 0.01 to 3 μm, particularly 0.05 to 3 μm. It is preferable to contain 5 to 90 volume% of the total solid content contained in the intermediate layer.

  It is also desirable to contain an ionene conductive polymer described in JP-A-9-203810, a quaternary ammonium cation conductive polymer having intermolecular crosslinking, or the like.

  The characteristic of the cross-linked cationic conductive polymer is the dispersible granular polymer obtained, and it can have a high concentration and high density of the cationic component in the particles, so it has not only excellent conductivity. No deterioration of conductivity was observed even under low relative humidity, and although the particles were well dispersed in the dispersed state, the film strength was also good because of the good adhesion between the particles in the film formation process after coating. It is strong and has excellent adhesion to other substances such as supports, and has excellent chemical resistance.

  The dispersible granular polymer, which is a crosslinked cationic conductive polymer used in the antistatic layer, is generally in the particle size range of about 0.05 μm to 0.5 μm, preferably in the range of 0.05 μm to 0.2 μm. Size is used. As used herein, the term dispersible particulate polymer is a polymer that appears as a clear or slightly turbid solution by visual observation but appears as a granular dispersion under an electron microscope. By using a coating composition that does not substantially contain dust (foreign matter) larger than the particle size corresponding to the film thickness of the upper layer in the intermediate layer coating composition, failure of the upper layer foreign matter can be prevented.

  The ratio of the fine particles to the binder is preferably 0.1 to 4 parts by mass of the binder with respect to 1 part by mass of the fine particles, and particularly the adhesiveness after UV irradiation is such that the binder is contained with respect to 1 part by mass of the fine particles. It is preferable that it is 1-2 mass parts.

  The method of applying the coating composition of the present invention includes doctor coating, extrusion coating, slide coating, roll coating, gravure coating, wire bar coating, reverse coating, curtain coating, die coating, spray coating, ink jet method, or U.S. Pat. The wet film thickness is 5 to 60 μm by an extrusion coating method using a hopper described in the specification of 681,294. If it is less than 5 μm, the effect of the present invention is not exhibited, and if it exceeds 60 μm, peeling, cracking, scratches, etc., flatness deterioration and interference unevenness are caused.

<Cellulose ester film>
The molecular weight of the cellulose ester used for the cellulose ester film used as the substrate of the present invention is 80000-200000 in terms of number average molecular weight (Mn). More preferred are 100,000 to 200,000, particularly preferably 150,000 to 200,000.

  Further, the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), Mw / Mn, is in the range of 1.4 to 3.0 as described above, preferably 1.7 to 2.2. It is a range.

  The average molecular weight and molecular weight distribution of the cellulose ester can be measured by a known method using high performance liquid chromatography. Using this, the number average molecular weight and the weight average molecular weight can be calculated, and the ratio (Mw / Mn) can be calculated.

The measurement conditions are as follows.
Solvent: Methylene chloride column: Shodex K806, K805, K803G (used by connecting 3 products manufactured by Showa Denko KK)
Column temperature: 25 ° C
Sample concentration: 0.1% by mass
Detector: RI Model 504 (manufactured by GL Sciences)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0ml / min
Calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corp.) Mw = 100000-500 calibration curves with 13 samples were used. The 13 samples are preferably used at approximately equal intervals.

  The cellulose ester used in the present invention is a carboxylic acid ester having about 2 to 22 carbon atoms, may be an aromatic carboxylic acid ester, and is particularly preferably a lower fatty acid ester of cellulose. The lower fatty acid in the lower fatty acid ester of cellulose means a fatty acid having 6 or less carbon atoms. For example, cellulose acetate, cellulose propionate, cellulose butyrate, cellulose acetate phthalate, etc., JP-A-10-45804, Mixed fatty acid esters such as cellulose acetate propionate and cellulose acetate butyrate as described in U.S. Pat. No. 8,231,761, U.S. Pat. No. 2,319,052 can be used. Among the above descriptions, the lower fatty acid esters of cellulose particularly preferably used are cellulose triacetate and cellulose acetate propionate. These cellulose esters can be used as a mixture.

  In the case of cellulose triacetate, those having a total acyl group substitution degree (acetyl group substitution degree) of 2.6 to 2.9 are preferably used.

  Preferred cellulose esters other than cellulose triacetate have an acyl group having 2 to 4 carbon atoms as a substituent, the substitution degree of acetyl group is X, and the substitution degree of propionyl group is Y, the following formula (I) And (II) at the same time.

Formula (I) 2.6 ≦ X + Y ≦ 2.9
Formula (II) 0 ≦ X ≦ 2.5
Among them, cellulose acetate propionate (total acyl group substitution degree = X + Y) satisfying 1.9 ≦ X ≦ 2.5 and 0.1 ≦ Y ≦ 0.9 is preferable. The portion not substituted with an acyl group usually exists as a hydroxyl group. These can be synthesized by known methods.

  These acyl group substitution degrees can be measured according to the method prescribed in ASTM-D817-96.

  As the cellulose ester, cellulose ester synthesized from cotton linter, wood pulp, kenaf or the like as a raw material can be used alone or in combination. In particular, it is preferable to use a cotton linter (hereinafter sometimes simply referred to as a linter) or a cellulose ester synthesized from wood pulp alone or in combination.

  Moreover, the cellulose ester obtained from these can be mixed and used in arbitrary ratios, respectively. These cellulose esters are prepared by using an organic acid such as acetic acid or an organic solvent such as methylene chloride when sulfuric acid is used as the acylating agent (acetic anhydride, propionic anhydride, butyric anhydride). It can obtain by making it react by a conventional method using a protic catalyst like.

  In the case of acetyl cellulose, it is necessary to extend the time for the acetylation reaction in order to increase the acetylation rate. However, if the reaction time is too long, the decomposition proceeds at the same time, and the polymer chain is broken and the acetyl group is decomposed, resulting in undesirable results. Therefore, it is necessary to set the reaction time within a certain range in order to increase the degree of acetylation and suppress decomposition to some extent. It is not appropriate to define the reaction time because the reaction conditions are various and greatly change depending on the reaction apparatus, equipment and other conditions. As the decomposition of the polymer progresses, the molecular weight distribution becomes wider. Therefore, in the case of cellulose ester, the degree of decomposition can be defined by the value of weight average molecular weight (Mw) / number average molecular weight (Mn) that is usually used. In other words, in the process of acetylation of cellulose triacetate, the weight average molecular weight is used as one index of the reaction degree for allowing the acetylation reaction to be carried out for a sufficient time for acetylation without being too long and being decomposed too much. The value of (Mw) / number average molecular weight (Mn) can be used.

  An example of a method for producing a cellulose ester is shown below: 100 parts by mass of a flocculent linter was crushed as a cellulose raw material, 40 parts by mass of acetic acid was added, and pretreatment activation was performed at 36 ° C. for 20 minutes. Thereafter, 8 parts by mass of sulfuric acid, 260 parts by mass of acetic anhydride and 350 parts by mass of acetic acid were added, and esterification was performed at 36 ° C. for 120 minutes. After neutralization with 11 parts by mass of a 24% magnesium acetate aqueous solution, saponification aging was carried out at 63 ° C. for 35 minutes to obtain acetylcellulose. This was stirred for 160 minutes at room temperature using a 10-fold acetic acid aqueous solution (acetic acid: water = 1: 1 (mass ratio)), then filtered and dried to obtain purified acetylcellulose having an acetyl substitution degree of 2.75. . This acetylcellulose had Mn of 92000, Mw of 156000, and Mw / Mn of 1.7. Similarly, cellulose esters having different degrees of substitution and Mw / Mn ratios can be synthesized by adjusting the esterification conditions (temperature, time, stirring) and hydrolysis conditions of the cellulose ester.

  The synthesized cellulose ester is preferably purified to remove low molecular weight components or to remove unacetylated or low acetylated components by filtration.

  In the case of a mixed acid cellulose ester, it can be obtained by a reaction described in JP-A-10-45804. The measuring method of the substitution degree of an acyl group can be measured according to the provisions of ASTM-D817-96.

  Cellulose esters are also affected by trace metal components in cellulose esters. These are considered to be related to water used in the production process, but it is preferable that there are few components that can become insoluble nuclei, and metal ions such as iron, calcium, and magnesium contain organic acidic groups. Insoluble matter may be formed by salt formation with a polymer degradation product or the like that may be present, and it is preferable that the amount is small. The iron (Fe) component is preferably 1 ppm or less. About calcium (Ca) component, it is contained in a lot of ground water and river water, etc., and it becomes hard water, and it is unsuitable as drinking water. Coordination compounds with ligands, that is, complexes are easily formed, and scum (insoluble starch, turbidity) derived from many insoluble calcium is formed.

  The calcium (Ca) component is 60 ppm or less, preferably 0 to 30 ppm. The magnesium (Mg) component is preferably in the range of 0 to 70 ppm, and more preferably 0 to 20 ppm, because too much will cause insoluble matter. Metal components such as iron (Fe) content, calcium (Ca) content, magnesium (Mg) content, etc. are pre-processed by completely digesting cellulose ester with micro digest wet cracking equipment (sulfuric acid decomposition) and alkali melting. After performing, it can obtain | require by performing an analysis using ICP-AES (inductively coupled plasma emission spectroscopy analyzer).

<Plasticizer>
The cellulose ester film used in the present invention contains at least two kinds of plasticizers. Moreover, it is preferable not to contain phosphate ester plasticizers, such as a triphenyl phosphate, substantially. “Substantially not containing” means that the content of the phosphoric ester plasticizer is less than 1% by mass, preferably 0.1% by mass, particularly preferably not added.

  By including two or more plasticizers, elution of the plasticizer can be reduced. The reason is not clear, but it seems that elution is suppressed by the ability to reduce the amount added per type and the interaction between the two plasticizers and the cellulose ester. When the plasticizer elutes in the upper layer of the base material, the base material is deformed and the flatness is easily deteriorated. Therefore, it is important to reduce the elution amount.

  The two plasticizers are not particularly limited, but are preferably selected from the polyhydric alcohol ester plasticizer, phthalate ester, citrate ester, fatty acid ester, glycolate plasticizer, and the like. Of these, at least one is preferably a polyhydric alcohol ester plasticizer.

  The polyhydric alcohol ester plasticizer is a plasticizer comprising an ester of a dihydric or higher aliphatic polyhydric alcohol and a monocarboxylic acid, and preferably has an aromatic ring or a cycloalkyl ring in the molecule. Preferably it is a 2-20 valent aliphatic polyhydric alcohol ester.

  The polyhydric alcohol used in the present invention is represented by the following general formula (1).

Formula (1) R _1- (OH) _n
However, R ₁ represents an n-valent organic group, n represents a positive integer of 2 or more, and the OH group represents an alcoholic and / or phenolic hydroxyl group.

  Examples of preferred polyhydric alcohols include the following, but the present invention is not limited to these. Adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, 1,2-butanediol, 1,3- Butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane- Examples include 1,3,5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, and xylitol. In particular, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, sorbitol, trimethylolpropane, and xylitol are preferable.

  There is no restriction | limiting in particular as monocarboxylic acid used for the polyhydric alcohol ester of this invention, Well-known aliphatic monocarboxylic acid, alicyclic monocarboxylic acid, aromatic monocarboxylic acid, etc. can be used. Use of an alicyclic monocarboxylic acid or aromatic monocarboxylic acid is preferred in terms of improving moisture permeability and retention.

  Examples of preferred monocarboxylic acids include the following, but the present invention is not limited thereto.

  As the aliphatic monocarboxylic acid, a fatty acid having a straight chain or a side chain having 1 to 32 carbon atoms can be preferably used. The number of carbon atoms is more preferably 1-20, and particularly preferably 1-10. When acetic acid is contained, the compatibility with the cellulose ester is increased, and it is also preferable to use a mixture of acetic acid and another monocarboxylic acid.

  Preferred aliphatic monocarboxylic acids include acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, 2-ethyl-hexanoic acid, undecylic acid, lauric acid, tridecylic acid, Saturated fatty acids such as myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, heptacosanoic acid, montanic acid, melicic acid, laccelic acid, undecylenic acid, olein Examples thereof include unsaturated fatty acids such as acid, sorbic acid, linoleic acid, linolenic acid, and arachidonic acid.

  Examples of preferable alicyclic monocarboxylic acids include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cyclooctanecarboxylic acid, and derivatives thereof.

  Examples of preferred aromatic monocarboxylic acids include those in which an alkyl group is introduced into the benzene ring of benzoic acid such as benzoic acid and toluic acid, and two or more benzene rings such as biphenylcarboxylic acid, naphthalenecarboxylic acid, and tetralincarboxylic acid. The aromatic monocarboxylic acid which has, or those derivatives can be mentioned. Benzoic acid is particularly preferable.

  The molecular weight of the polyhydric alcohol ester is not particularly limited, but is preferably 300 to 1500, and more preferably 350 to 750. A higher molecular weight is preferred because it is less likely to volatilize, and a smaller one is preferred in terms of moisture permeability and compatibility with cellulose ester.

  The carboxylic acid used for the polyhydric alcohol ester may be one kind or a mixture of two or more kinds. Moreover, all the OH groups in the polyhydric alcohol may be esterified, or a part of the OH groups may be left as they are.

  Below, the specific compound of a polyhydric alcohol ester is illustrated.

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

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

  Examples of the citrate plasticizer include acetyl trimethyl citrate, acetyl triethyl citrate, and acetyl tributyl citrate.

  Examples of fatty acid ester plasticizers include butyl oleate, methylacetyl ricinoleate, and dibutyl sebacate.

  Examples of the phosphate ester plasticizer include triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, and the like. It is preferable that the agent is not substantially contained in the cellulose ester film constituting the present invention. As described above, “not containing substantially” means that the content is less than 1% by mass, preferably less than 0.1% by mass, and particularly preferably not contained at all.

  As described above, it is particularly preferable that the addition amount of the phosphoric ester plasticizer is small because the base material is not easily deformed when the intermediate layer and the hard coat layer are formed, and the flatness is excellent.

  The total content of the plasticizer in the cellulose ester film is preferably 5 to 20% by mass, more preferably 6 to 16% by mass, and particularly preferably 8 to 13% by mass with respect to the total solid content. The contents of the two kinds of plasticizers are each at least 1% by mass, preferably 2% by mass or more.

  The polyhydric alcohol ester plasticizer is preferably contained in an amount of 1 to 12% by mass, particularly preferably 3 to 11% by mass. If the amount is too small, deterioration of flatness is recognized, and if it is too large, bleeding out tends to occur. The mass ratio between the polyhydric alcohol ester plasticizer and the other plasticizer is preferably in the range of 1: 4 to 4: 1, more preferably 1: 3 to 3: 1. If the amount of the plasticizer added is too large or too small, the film is liable to be deformed, which is not preferable.

<Ultraviolet absorber>
The cellulose ester film according to the present invention contains an ultraviolet absorber. The ultraviolet absorber is intended to improve durability by absorbing ultraviolet light having a wavelength of 400 nm or less, and the transmittance at a wavelength of 370 nm is particularly preferably 10% or less, more preferably 5% or less. Preferably it is 2% or less.

  Although the ultraviolet absorber used in the present invention is not particularly limited, for example, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, triazine compounds, nickel complex compounds, inorganic powders Examples include the body.

  For example, 5-chloro-2- (3,5-di-sec-butyl-2-hydroxylphenyl) -2H-benzotriazole, (2-2H-benzotriazol-2-yl) -6- (linear and side Chain dodecyl) -4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone, etc., and tinuvin 109, tinuvin 171, tinuvin 234, tinuvin 326, tinuvin 327, tinuvin 328, etc. These are commercially available products manufactured by Ciba Specialty Chemicals and can be preferably used.

  For example, as the benzotriazole ultraviolet absorber, a compound represented by the following general formula (A) can be used.

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

  Moreover, these groups described above may have an arbitrary substituent.

  Although the specific example of the ultraviolet absorber which concerns on this invention is given to the following, this invention is not limited to these.

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-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)
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-benzotriazol-2-yl) phenyl] propionate (Tinuvin 109)
Furthermore, the ultraviolet absorber preferably used in the present invention is a benzophenone ultraviolet absorber.

  As the benzophenone-based ultraviolet absorber, a compound represented by the following general formula (B) is preferably used.

In the formula, Y represents a hydrogen atom, a halogen atom or an alkyl group, an alkenyl group, an alkoxyl group, and a phenyl group, and these alkyl group, alkenyl group, and phenyl group may have a substituent. A represents a hydrogen atom, an alkyl group, an alkenyl group, a phenyl group, a cycloalkyl group, an alkylcarbonyl group, an alkylsulfonyl group or a —CO (NH) _{n -1-} D group, and D represents an alkyl group, an alkenyl group or a substituent. Represents a phenyl group which may have m and n represent 1 or 2.

  In the above, the alkyl group represents, for example, a linear or branched aliphatic group having up to 24 carbon atoms, the alkoxyl group represents, for example, an alkoxyl group having up to 18 carbon atoms, and the alkenyl group has, for example, carbon number An alkenyl group up to 16 represents an allyl group, a 2-butenyl group, or the like. In addition, as substituents to alkyl groups, alkenyl groups, and phenyl groups, halogen atoms such as chlorine atoms, bromine atoms, fluorine atoms, etc., hydroxyl groups, phenyl groups (this phenyl group is substituted with alkyl groups or halogen atoms, etc.) May be used).

  Specific examples of the benzophenone compound represented by the general formula (B) are shown below, but the present 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)
Moreover, the triazine type compound shown by the general formula (I) of Unexamined-Japanese-Patent No. 2001-235621 is also preferably used for the cellulose ester film which concerns on this invention.

  The cellulose ester film according to the present invention preferably contains two or more ultraviolet absorbers.

  As the UV absorber, a polymer UV absorber can be preferably used, and in particular, a polymer type UV absorber described in JP-A-6-148430 is preferably used.

  The method of adding the UV absorber may be added to the dope after the UV absorber is dissolved in an alcohol such as methanol, ethanol or butanol, an organic solvent such as methylene chloride, methyl acetate, acetone or dioxolane, or a mixed solvent thereof. Or you may add directly in dope composition. For an inorganic powder that does not dissolve in an organic solvent, a dissolver or a sand mill is used in the organic solvent and cellulose ester to disperse and then added to the dope.

  The amount of UV absorber used is not uniform depending on the type of UV absorber, operating conditions, etc., but when the dry film thickness of the cellulose ester film is 30 to 200 μm, it is 0.5 to 4 with respect to the cellulose ester film. 0.0 mass% is preferable, and 0.6 to 2.0 mass% is still more preferable.

<Fine particles>
The cellulose ester film according to the present invention preferably contains fine particles.

  As fine particles used in the present invention, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, and hydrated silicic acid. Mention may be made of calcium, aluminum silicate, magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low turbidity, and silicon dioxide is particularly preferable.

  The average primary particle diameter of the fine particles is preferably 5 to 50 nm, and more preferably 7 to 20 nm. These are preferably contained mainly as secondary aggregates having a particle size of 0.05 to 0.3 μm. The content of these fine particles in the cellulose ester film is preferably 0.05 to 1% by mass, particularly preferably 0.1 to 0.5% by mass. In the case of a cellulose ester film having a multilayer structure by the co-casting method, it is preferable to contain fine particles of this addition amount on the surface.

  Silicon dioxide fine particles are commercially available, for example, under the trade names Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above Nippon Aerosil Co., Ltd.). I can do it.

  Zirconium oxide fine particles are commercially available under the trade names of Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used.

  Examples of the polymer include silicone resin, fluorine resin, and acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (manufactured by Toshiba Silicone Co., Ltd.) It is marketed by name and can be used.

  Among these, Aerosil 200V and Aerosil R972V are particularly preferably used because they have a large effect of reducing the friction coefficient while keeping the turbidity of the cellulose ester film low. In the cellulose ester film used in the present invention, the dynamic friction coefficient on the back side of the hard coat layer is preferably 1.0 or less.

<dye>
A dye may be added to the cellulose ester film used in the present invention to adjust the color. For example, a blue dye may be added to suppress the yellowness of the film. Preferred examples of the dye include anthraquinone dyes.

  The anthraquinone dye may have an arbitrary substituent at an arbitrary position from the 1st position to the 8th position of the anthraquinone. Preferred substituents include an anilino group, hydroxyl group, amino group, nitro group, or hydrogen atom. In particular, it is preferable to contain a blue dye described in JP-A-2001-154017, particularly an anthraquinone dye.

  Various additives may be batch-added to a dope that is a cellulose ester-containing solution before film formation, or an additive solution may be separately prepared and added in-line. In particular, it is preferable to add a part or all of the fine particles in-line in order to reduce the load on the filter medium.

  When the additive solution is added in-line, it is preferable to dissolve a small amount of cellulose ester in order to improve mixing with the dope. The amount of the cellulose ester is preferably 1 to 10 parts by mass, more preferably 3 to 5 parts by mass with respect to 100 parts by mass of the solvent.

  In order to perform in-line addition and mixing in the present invention, for example, an in-line mixer such as a static mixer (manufactured by Toray Engineering), SWJ (Toray static type in-tube mixer Hi-Mixer) or the like is preferably used.

<Method for producing cellulose ester film>
Next, the manufacturing method of the cellulose-ester film of this invention is demonstrated.

  The cellulose ester film of the present invention is prepared by dissolving a cellulose ester and an additive in a solvent to prepare a dope, casting a dope onto an endless metal support, and casting the dope. It is carried out by a step of drying as a web, a step of peeling from a metal support, a step of stretching or maintaining the width, a step of further drying, and a step of winding up the finished film.

  The process for preparing the dope will be described. The concentration of cellulose ester in the dope is preferably higher because the drying load after casting on the metal support can be reduced, but if the concentration of cellulose ester is too high, the load during filtration increases and the filtration accuracy is poor. Become. As a density | concentration which makes these compatible, 10-35 mass% is preferable, More preferably, it is 15-25 mass%.

  The solvent used in the dope of the present invention may be used alone or in combination of two or more. However, it is preferable from the viewpoint of production efficiency that a good solvent and a poor solvent of cellulose ester are mixed and used. The more solvent is preferable from the viewpoint of solubility of the cellulose ester. The preferable range of the mixing ratio of the good solvent and the poor solvent is 70 to 98% by mass for the good solvent and 2 to 30% by mass for the poor solvent. With a good solvent and a poor solvent, what dissolve | melts the cellulose ester to be used independently is defined as a good solvent, and what poorly swells or does not melt | dissolve is defined as a poor solvent. Therefore, depending on the average acetylation degree (acetyl group substitution degree) of the cellulose ester, the good solvent and the poor solvent change. For example, when acetone is used as the solvent, the cellulose ester acetate ester (acetyl group substitution degree 2.4), cellulose Acetate propionate is a good solvent, and cellulose acetate (acetyl group substitution degree 2.8) is a poor solvent.

  Although the good solvent used for this invention is not specifically limited, Organic halogen compounds, such as a methylene chloride, dioxolanes, acetone, methyl acetate, methyl acetoacetate, etc. are mentioned. Particularly preferred is methylene chloride or methyl acetate.

  Moreover, although the poor solvent used for this invention is not specifically limited, For example, methanol, ethanol, n-butanol, cyclohexane, cyclohexanone, etc. are used preferably.

  As a preferable solvent composition, methylene chloride 80 to 95% by mass, ethanol 5 to 20% by mass, or a combination of methyl acetate 60 to 95% by mass and ethanol 5 to 40% by mass can be mentioned. Moreover, it is also preferable that water contains 0.01-2 mass% in dope.

  A general method can be used as a method of dissolving the cellulose ester when preparing the dope described above. When heating and pressurization are combined, it is possible to heat above the boiling point at normal pressure. It is preferable to stir and dissolve while heating at a temperature that is equal to or higher than the boiling point of the solvent at normal pressure and that the solvent does not boil under pressure, in order to prevent the generation of massive undissolved materials called gels and mamaco. Moreover, after mixing a cellulose ester with a poor solvent and making it wet or swell, the method of adding a good solvent and melt | dissolving is also used preferably.

  The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or a method of increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy.

  The heating temperature with the addition of the solvent is preferably higher from the viewpoint of the solubility of the cellulose ester, but if the heating temperature is too high, the required pressure increases and the productivity deteriorates. A preferable heating temperature is 45 to 120 ° C, more preferably 60 to 110 ° C, and still more preferably 70 ° C to 105 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature.

  Alternatively, a cooling dissolution method is also preferably used, whereby the cellulose ester can be dissolved in a solvent such as methyl acetate.

  Next, this cellulose ester solution is filtered using a suitable filter medium such as filter paper. As the filter medium, it is preferable that the absolute filtration accuracy is small in order to remove insoluble matters and the like, but there is a problem that the filter medium is likely to be clogged if the absolute filtration accuracy is too small. For this reason, a filter medium with an absolute filtration accuracy of 0.008 mm or less is preferable, a filter medium with 0.001 to 0.008 mm is more preferable, and a filter medium with 0.003 to 0.006 mm is still more preferable.

  The material of the filter medium is not particularly limited, and a normal filter medium can be used. However, a plastic filter medium such as polypropylene and Teflon (R) and a metal filter medium such as stainless steel are preferable because there is no loss of fibers. . It is preferable to remove and reduce impurities, particularly bright spot foreign matter, contained in the raw material cellulose ester by filtration.

A bright spot foreign substance is when two polarizing plates are placed in a crossed Nicol state, a cellulose ester film is placed between them, light is applied from the side of one polarizing plate, and observed from the side of the other polarizing plate. It is a point (foreign matter) where light from the opposite side appears to leak, and the number of bright spots having a diameter of 0.01 mm or more is preferably 200 / cm ² or less. More preferably, it is 100 pieces / cm < ² > or less, More preferably, it is 50 pieces / m < ² > or less, More preferably, it is 0-10 pieces / cm < ² > or less. Further, it is preferable that the number of bright spots of 0.01 mm or less is small.

  The dope can be filtered by an ordinary method, but the method of filtering while heating at a temperature not lower than the boiling point of the solvent at normal pressure and in a range where the solvent does not boil under pressure is the filtration pressure before and after filtration. The increase in the difference (referred to as differential pressure) is small and preferable. A preferred temperature is 45 to 120 ° C, more preferably 45 to 70 ° C, and still more preferably 45 to 55 ° C.

  A smaller filtration pressure is preferred. The filtration pressure is preferably 1.6 MPa or less, more preferably 1.2 MPa or less, and further preferably 1.0 MPa or less.

  Here, the dope casting will be described.

  The metal support in the casting (casting) step preferably has a mirror-finished surface, and a stainless steel belt or a drum whose surface is plated with a casting is preferably used as the metal support. The cast width can be 1 to 4 m. The surface temperature of the metal support in the casting step is −50 ° C. to a temperature lower than the boiling point of the solvent, and a higher temperature is preferable because the web drying rate can be increased. May deteriorate. The support temperature varies depending on the solvent used, but is preferably 0 to 70 ° C, more preferably 5 to 40 ° C. Alternatively, it is also a preferable method that the web is gelled by cooling and peeled from the drum in a state containing a large amount of residual solvent. The method for controlling the temperature of the metal support is not particularly limited, and there are a method of blowing hot air or cold air, and a method of contacting hot water with the back side of the metal support. It is preferable to use warm water because heat transfer is performed efficiently, so that the time until the temperature of the metal support becomes constant is short. When warm air is used, wind at a temperature higher than the target temperature may be used.

  In order for the cellulose ester film to exhibit good flatness, the residual solvent amount when peeling the web from the metal support is preferably 10 to 150% by mass, more preferably 20 to 40% by mass or 60 to 130% by mass. Especially preferably, it is 20-30 mass% or 70-120 mass%.

  In the present invention, the amount of residual solvent is defined by the following formula.

Residual solvent amount (% by mass) = {(MN) / N} × 100
M is the mass of a sample collected during or after the production of the web or film, and N is the mass after heating M at 115 ° C. for 1 hour.

  Further, in the drying step of the cellulose ester film, the web is peeled off from the metal support, and further dried, and the residual solvent amount is preferably 1% by mass or less, more preferably 0.1% by mass or less, Especially preferably, it is 0-0.01 mass% or less.

  In the film drying process, generally, a roll drying method (a method in which a plurality of rolls arranged on the upper and lower sides are alternately passed through and dried) or a method of drying while transporting the web by a tenter method is adopted.

  In order to produce the cellulose ester film for the hard coat film of the present invention, the web is stretched in the conveying direction (longitudinal direction) where the amount of residual solvent of the web immediately after peeling from the metal support is large, and both ends of the web are clipped. It is particularly preferable to perform stretching (biaxial stretching) in the width direction (lateral direction) by a tenter method that grips with, for example. The preferred draw ratio in both the machine direction and the transverse direction is 1.05 to 1.3 times, and 1.05 to 1.15 times is particularly preferred. It is preferable that the area is 1.12 times to 1.44 times, and preferably 1.15 times to 1.32 times due to longitudinal and lateral stretching. This can be determined by the draw ratio in the longitudinal direction × the draw ratio in the transverse direction. If one of the stretching ratios in the machine direction and the transverse direction is less than 1.05, the flatness deterioration due to ultraviolet irradiation when forming the hard coat layer is not preferable. A draw ratio of 1.3 times or less is preferable because of excellent flatness and low haze.

  In order to stretch in the longitudinal direction immediately after peeling, peeling is preferably performed at a peeling tension of 210 N / m or more, particularly preferably 220 to 300 N / m.

  The means for drying the web is not particularly limited, and can be generally performed with hot air, infrared rays, a heating roll, microwave, or the like, but it is preferably performed with hot air in terms of simplicity.

  The drying temperature in the web drying step is preferably increased stepwise from 40 to 150 ° C, and more preferably from 50 to 140 ° C in order to improve dimensional stability.

  Although the film thickness of a cellulose-ester film is not specifically limited, 10-200 micrometers is used preferably. Particularly, it was difficult to obtain a hard coat film excellent in flatness and hardness with a thin film of 10 to 70 μm, but according to the present invention, a thin hard coat film excellent in flatness and hardness was obtained, Moreover, since it is excellent also in productivity, it is especially preferable that the film thickness of a cellulose-ester film is 10-70 micrometers. More preferably, it is 20-60 micrometers. Most preferably, it is 35-60 micrometers.

  As the hard coat film of the present invention, a cellulose ester film having a width of 1 to 4 m is preferably used.

  When the width of the cellulose ester film becomes wider, the illuminance unevenness of the irradiated light during UV curing cannot be ignored, not only the flatness deteriorates, but also the hardness unevenness. When the antireflection layer is formed on this, the reflection unevenness There was a problem that became prominent. Since the hard coat film of the present invention can provide sufficient hardness with a small amount of irradiation, even if there is unevenness of the irradiation amount in the width direction of the irradiation light, there is little unevenness in the width direction of the hardness, and the hardness excellent in flatness Since a coated film is obtained, a remarkable effect is recognized with a wide cellulose ester film. In particular, those having a width of 1.4 to 4 m are preferably used, and particularly preferably 1.4 to 2 m. If it exceeds 4 m, conveyance becomes difficult.

  A long film having a length of 1000 to 6000 m is preferably used. Moreover, it is preferable that a knurling part having a height of 0 to 25% with respect to the film thickness is provided at both ends of the width.

<Physical properties>
The moisture permeability of the cellulose ester film used in the present invention, 40 ° C., or less 850g / m ² · 24h at 90% RH, preferably ^{20~800g / m 2 · 24h, 20~750g} / m 2 · 24 h is particularly preferable. The moisture permeability can be measured according to the method described in JIS Z 0208.

  The breaking elongation of the cellulose ester film used in the present invention is preferably 10 to 80%, and more preferably 20 to 50%.

  The visible light transmittance of the cellulose ester film used in the present invention is preferably 90% or more, and more preferably 93% or more.

  The haze of the cellulose ester film used in the present invention is preferably less than 1%, particularly preferably 0 to 0.1%.

  The in-plane retardation value (Ro) of the cellulose ester film used in the present invention is preferably 0 to 70 nm or less. More preferably, it is 0-30 nm or less, More preferably, it is 0-10 nm or less. The retardation value (Rt) in the film thickness direction is preferably 400 nm or less, preferably 10 to 200 nm, and more preferably 30 to 150 nm.

  The retardation values (Ro) and (Rt) can be obtained by the following formula.

Ro = (nx−ny) × d
Rt = ((nx + ny) / 2−nz) × d
Here, d is the thickness (nm) of the cellulose ester film, the refractive index nx (the maximum refractive index in the plane of the film, also referred to as the refractive index in the slow axis direction), ny (in the film plane, perpendicular to the slow axis). Index of refraction in a certain direction) and nz (refractive index of the film in the thickness direction).

  The retardation values (Ro) and (Rt) can be measured using an automatic birefringence meter. For example, the wavelength can be obtained at 590 nm in an environment of 23 ° C. and 55% RH using KOBRA-21ADH (Oji Scientific Instruments).

  The slow axis is preferably in the width direction ± 1 ° of the film or in the longitudinal direction ± 1 °.

<Actinic radiation curable resin layer>
A method for producing the active ray curable resin layer of the hard coat film of the present invention will be described.

  In the hard coat film of the present invention, an actinic radiation curable resin layer is preferably used as the hard coat layer.

  The actinic radiation curable resin layer refers to a layer mainly composed of a resin that cures through a crosslinking reaction or the like by irradiation with actinic rays such as ultraviolet rays or electron beams. As the actinic radiation curable resin, a component containing a monomer having an ethylenically unsaturated double bond is preferably used, and a hard coat layer is formed by curing by irradiation with actinic radiation such as ultraviolet rays or electron beams. Typical examples of the actinic radiation curable resin include an ultraviolet curable resin and an electron beam curable resin, and a resin curable by ultraviolet irradiation is preferable.

  As the ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, or an ultraviolet curable epoxy resin is preferable. Used.

  UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylates) in products obtained by reacting polyester polyols with isocyanate monomers or prepolymers. It can be easily obtained by reacting an acrylate monomer having a hydroxyl group such as 2-hydroxypropyl acrylate. For example, those described in JP-A-59-151110 can be used.

  For example, a mixture of 100 parts Unidic 17-806 (Dainippon Ink Co., Ltd.) and 1 part Coronate L (Nihon Polyurethane Co., Ltd.) is preferably used.

  Examples of UV curable polyester acrylate resins include those that are easily formed when 2-hydroxyethyl acrylate and 2-hydroxy acrylate monomers are generally reacted with polyester polyols. JP-A-59-151112 Can be used.

  Specific examples of the ultraviolet curable epoxy acrylate resin include an epoxy acrylate as an oligomer, a reactive diluent and a photoreaction initiator added thereto, and reacted to form an oligomer. The thing as described in 105738 can be used.

  Specific examples of UV curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate, etc. I can list them.

  Specific examples of the photoreaction initiator of these ultraviolet curable resins include benzoin and its derivatives, acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof. You may use with a photosensitizer. The photoinitiator can also be used as a photosensitizer. In addition, when using an epoxy acrylate photoinitiator, a sensitizer such as n-butylamine, triethylamine, or tri-n-butylphosphine can be used. The photoreaction initiator or photosensitizer used in the ultraviolet curable resin composition is 0.1 to 15 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the composition.

  Examples of the resin monomer include general monomers such as methyl acrylate, ethyl acrylate, butyl acrylate, benzyl acrylate, cyclohexyl acrylate, vinyl acetate, and styrene as monomers having one unsaturated double bond. In addition, monomers having two or more unsaturated double bonds include ethylene glycol diacrylate, propylene glycol diacrylate, divinylbenzene, 1,4-cyclohexane diacrylate, 1,4-cyclohexyldimethyl adiacrylate, and the above trimethylolpropane. Examples thereof include triacrylate and pentaerythritol tetraacryl ester.

  Examples of commercially available ultraviolet curable resins that can be used in the present invention include ADEKA OPTMER KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (Asahi Denka ( Co., Ltd.); Koeihard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102, NS -101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Co., Ltd.); Seika Beam PHC2210 (S), PHC X-9 (K-3), PHC2213, DP -10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (manufactured by Dainichi Seika Kogyo Co., Ltd.) KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel UCB Corporation); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120 RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (manufactured by Dainippon Ink & Chemicals, Inc.); 340 clear (manufactured by China Paint Co., Ltd.); Sunrad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (manufactured by Sanyo Chemical Industries); SP -1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.); RCC-15C (manufactured by Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.), etc. Can be selected as appropriate.

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

  These actinic ray curable resin layers can be coated by a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method.

As a light source for curing an ultraviolet curable resin by a photocuring reaction to form a cured film layer, any light source that generates ultraviolet rays can be used without any limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, or the like can be used. Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is preferably 5 to 200 mJ / cm ² , and particularly preferably 20 to 100 mJ / cm ² .

  With a conventional hard coat film, a hard coat film having a pencil hardness of 4H or more and excellent flatness cannot be obtained at such a low irradiation dose. In the case of a hard coat film that does not require much hardness, the amount of irradiation can be further reduced, so it is possible to produce a hard coat film at a speed much higher than the coating speed limited by the ability of the UV irradiation section, and productivity Is significantly improved.

  Moreover, when irradiating actinic radiation, it is preferable to carry out while applying tension | tensile_strength in the conveyance direction of a film, More preferably, it is performing applying tension | tensile_strength also in the width direction. The tension to be applied is preferably 30 to 300 N / m. The method for applying the tension is not particularly limited, and the tension may be applied in the conveying direction on the back roll, or the tension may be applied in the width direction or the biaxial direction by a tenter. This makes it possible to obtain a film having further excellent flatness.

  Examples of the organic solvent for the UV curable resin layer composition coating solution include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl). Ketone), esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, other organic solvents, or a mixture thereof. Propylene glycol monoalkyl ether (1 to 4 carbon atoms of the alkyl group) or propylene glycol monoalkyl ether acetate ester (1 to 4 carbon atoms of the alkyl group) is 5% by mass or more, more preferably 5 to 80%. It is preferable to use the organic solvent containing at least mass%.

  In addition, it is particularly preferable to add a silicon compound to the ultraviolet curable resin layer composition coating solution. For example, polyether-modified silicone oil is preferably added. The number average molecular weight of the polyether-modified silicone oil is, for example, 1,000 to 100,000, preferably 2,000 to 50,000.

  Commercially available silicon compounds include DKQ8-779 (trade name, manufactured by Dow Corning), SF3771, SF8410, SF8411, SF8419, SF8421, SF8428, SH200, SH510, SH1107, SH3749, SH3771, BX16-034, SH3746, SH3749, SH8400, SH3771M, SH3772M, SH3773M, SH3775M, BY-16-837, BY-16-839, BY-16-869, BY-16-870, BY-16-004, BY-16-891, BY-16 872, BY-16-874, BY22-008M, BY22-012M, FS-1265 (above, product names manufactured by Toray Dow Corning Silicone), KF-101, KF-100T, KF351, KF3 2, KF353, KF354, KF355, KF615, KF618, KF945, KF6004, Silicone X-22-945, X22-160AS (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), XF3940, XF3949 (trade name, manufactured by Toshiba Silicone Co., Ltd.) ), Disparon LS-009 (manufactured by Enomoto Kasei Co., Ltd.), Granol 410 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.), TSF4440, TSF4441, TSF4445, TSF4446, TSF4452, TSF4460 (manufactured by GE Toshiba Silicone), BYK-306, BYK- 330, BYK-307, BYK-341, BYK-344, BYK-361 (manufactured by BYK-Japan) L series (for example, L7001, L-7006, L-7604, L-9000) manufactured by Nippon Unicar Co., Ltd. Y Over's, FZ series (FZ-2203, FZ-2206, FZ-2207) and the like, are preferably used.

  These components enhance the applicability to the substrate and the lower layer. When added to the outermost surface layer of the laminate, it not only improves the water repellency, oil repellency and antifouling properties of the coating film, but also exhibits an effect on the scratch resistance of the surface. These components are preferably added in a range of 0.01 to 3% by mass with respect to the solid component in the coating solution.

  As a coating method of the ultraviolet curable resin composition coating solution, the above-described methods can be used. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm, as the wet film thickness. The dry film thickness is 0.1 to 10 μm, preferably 1 to 10 μm.

  More preferably, the film thickness of the cellulose ester film is 10 to 70 μm, and the ratio (d / H) of the film thickness (H) of the hard coat layer to the film thickness (d) of the cellulose ester film is 4 to 10 Excellent in hardness and scratch resistance as well as flatness. This is because the hardness and scratch resistance are inferior when the hard coat layer is thinner than the film thickness of the cellulose ester, and the flatness is deteriorated when the hard coat layer is thicker than the film thickness of the cellulose ester.

The ultraviolet curable resin composition is preferably irradiated with ultraviolet rays during or after coating and drying. The irradiation time for obtaining the irradiation dose of the active ray of 5 to 200 mJ / cm ² is from 0.1 second to 5 seconds. Minutes are good, and 0.1 to 10 seconds is more preferable from the viewpoint of curing efficiency or work efficiency of the ultraviolet curable resin.

Moreover, it is preferable that the illuminance of these active ray irradiation parts is 50-150 mW / m < ² >.

  In order to prevent blocking, to improve scratch resistance, to give antiglare properties, and to adjust the refractive index, fine particles of an inorganic compound or an organic compound may be added to the cured resin layer thus obtained. I can do it.

  The inorganic fine particles used in the hard coat layer include silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, and hydrated calcium silicate. And aluminum silicate, magnesium silicate and calcium phosphate. In particular, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide and the like are preferably used.

  Organic particles include polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, and melamine resin. It can be added to an ultraviolet curable resin composition such as powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, or polyfluoroethylene resin powder. Particularly preferred are cross-linked polystyrene particles (for example, SX-130H, SX-200H, SX-350H, manufactured by Soken Chemical) and polymethyl methacrylate-based particles (for example, MX150, MX300, manufactured by Soken Chemical).

  The average particle diameter of these fine particle powders is preferably 0.005 to 5 μm, and particularly preferably 0.01 to 1 μm. As for the ratio of a ultraviolet curable resin composition and fine particle powder, it is desirable to mix | blend so that it may be 0.1-30 mass parts with respect to 100 mass parts of resin compositions.

  The UV curable resin layer is a clear hard coat layer having a center line average roughness (Ra) defined by JIS B 0601 of 1 to 100 nm, or an antiglare layer having an Ra of about 0.1 to 1 μm. Is preferred. The center line average roughness (Ra) is preferably measured with an optical interference type surface roughness measuring instrument, and can be measured using, for example, RST / PLUS manufactured by WYKO.

<Back coat layer>
It is preferable to provide a backcoat layer on the surface of the hardcoat film of the present invention opposite to the side on which the hardcoat layer is provided. The back coat layer is provided to correct curl caused by providing a hard coat layer or other layers by coating or CVD. That is, the degree of curling can be balanced by imparting the property of being rounded with the surface on which the backcoat layer is provided facing inward. The back coat layer is preferably applied also as an anti-blocking layer. In that case, it is preferable that fine particles are added to the back coat layer coating composition in order to provide an anti-blocking function.

  As fine particles added to the back coat layer, examples of inorganic compounds include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, tin oxide, and indium oxide. Zinc oxide, ITO, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. Fine particles containing silicon are preferable in terms of low haze, and silicon dioxide is particularly preferable.

  These fine particles are commercially available under the trade names of, for example, Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, and TT600 (manufactured by Nippon Aerosil Co., Ltd.). . Zirconium oxide fine particles are commercially available under the trade names of Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) and can be used. Examples of the polymer include silicone resin, fluorine resin, and acrylic resin. Silicone resins are preferable, and those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120, and 240 (manufactured by Toshiba Silicone Co., Ltd.) It is marketed by name and can be used.

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

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

  Specifically, the back coat layer is formed by coating a coating composition containing a solvent capable of swelling or dissolving the cellulose ester film substrate. The solvent to be used may include a solvent that can swell or dissolve the base material and a solvent that does not dissolve the base material, and the coating composition and coating amount are mixed in an appropriate ratio depending on the curl degree of the base material and the type of resin. .

  When it is desired to enhance the curl prevention function, it is effective to increase the ratio of the solvent that can swell or dissolve the base material and to decrease the ratio of the solvent that does not swell or dissolve. The ratio of the solvent capable of swelling or dissolving the substrate to the coating composition solvent is preferably 100 to 10% by volume. Solvents that can swell or dissolve the substrate contained in such a mixed composition include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl oxide, methyl-n-amyl ketone, cyclohexanone, diacetone alcohol, diisobutyl ketone, methylcyclohexanone, and the like. Ketones, esters such as methyl acetate, ethyl acetate, ethyl lactate, butyl lactate, ethyl benzoate, methyl acetoacetate, ethers such as dioxolane, dioxane, methyl cellosolve, methyl carbitol, methyl cellosolve acetate, cellosolve acetate, etc. Polyhydric alcohol esters, furans such as tetrahydrofuran and furfural, acids such as glacial acetic acid, halogen hydrocarbons such as methylene chloride, ethylene dichloride and tetrachloroethane, nitro Tan, nitroethane, pyridine, dimethylformamide, nitrogen compounds such as nitrobenzene, sulfonic acids such as dimethyl sulfoxide and the like are suitably used. In consideration of drying after coating, a solvent that easily volatilizes is preferable, and a solvent having a boiling point of 200 ° C. or lower is preferable.

  Further, a solvent that does not swell or dissolve the substrate can be mixed and used in the range of 0 to 90% by volume with the above solvent. For example, alcohols such as methanol, ethanol, propanol, n-butanol, 2-butanol, tert-butanol, glycol ethers (propylene glycol mono (C1-C4) alkyl ether (specifically, propylene glycol monomethyl ether (PGME), Propylene glycol monoethyl ether, propylene glycol mono n-propyl ether, propylene glycol monoisopropyl ether, propylene glycol monobutyl ether, etc.), propylene glycol mono (C1-C4) alkyl ether ester (propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether) Acetate)), water, and other solvents.

  These coating compositions are preferably applied to the surface of the transparent resin film with a gravure coater, dip coater, reverse coater, wire bar coater, die coater, etc., with a wet film thickness of 1 to 100 μm, particularly 5 to 30 μm. Preferably there is.

  Examples of the resin used as the binder of the backcoat layer include vinyl chloride-vinyl acetate copolymer, vinyl chloride resin, vinyl acetate resin, vinyl acetate-vinyl alcohol copolymer, partially hydrolyzed vinyl chloride-vinyl acetate copolymer. Polymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-acrylonitrile copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyvinyl chloride, ethylene-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, etc. Vinyl polymer or copolymer, nitrocellulose, cellulose acetate propionate (preferably acetyl group substitution degree 1.8-2.3, propionyl group substitution degree 0.1-1.0), diacetyl cellulose, cellulose Cellulose derivatives such as acetate butyrate resin, maleic acid and / or Or acrylic acid copolymer, acrylic ester copolymer, acrylonitrile-styrene copolymer, chlorinated polyethylene, acrylonitrile-chlorinated polyethylene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, acrylic resin Rubber resins such as polyvinyl acetal resin, polyvinyl butyral resin, polyester polyurethane resin, polyether polyurethane resin, polycarbonate polyurethane resin, polyester resin, polyether resin, polyamide resin, amino resin, styrene-butadiene resin, butadiene-acrylonitrile resin, Examples thereof include, but are not limited to, silicone resins and fluorine resins. For example, as an acrylic resin, Acrypet MD, VH, MF, V (manufactured by Mitsubishi Rayon Co., Ltd.), Hyperl M-4003, M-4005, M-4006, M-4202, M-5000, M-5001, M-4501 (manufactured by Negami Kogyo Co., Ltd.), Dialnal BR-50, BR-52, BR-53, BR-60, BR-64, BR-73, BR-75, BR-77, BR-79, BR -80, BR-82, BR-83, BR-85, BR-87, BR-88, BR-90, BR-93, BR-95, BR-100, BR-101, BR-102, BR-105 BR-106, BR-107, BR-108, BR-112, BR-113, BR-115, BR-116, BR-117, BR-118, etc. (Mitsubishi Rayon Co., Ltd.) acrylic and The methacrylic monomers such as various homopolymers and copolymers were prepared as raw materials are commercially available, can also be selected preferred mono from this appropriate.

  Particularly preferred are cellulose resin layers such as diacetylcellulose and cellulose acetate propionate.

  The order of coating the backcoat layer may be before or after coating the cellulose ester film on the opposite side of the backcoat layer (clear hard coat layer or other layer such as an antistatic layer). When the back coat layer also serves as an anti-blocking layer, it is desirable to coat it first. Alternatively, the back coat layer can be applied in multiple layers in two or more steps.

  The hard coat film of the present invention is suitable for uniformly forming a thin film of a metal compound layer by coating or plasma CVD, particularly atmospheric pressure plasma treatment, and these are useful as an antireflection layer.

  As an atmospheric pressure plasma treatment method, for example, an atmospheric pressure plasma discharge treatment method for applying a high-frequency pulse voltage described in JP-A-11-181573, JP-A-2000-26632, JP-A-2002-110397, or the like can be used. Alternatively, the conductive layer can be provided by an atmospheric pressure plasma discharge processing method described in JP-A-2001-337201. Alternatively, the antireflection layer can be provided by the methods described in JP-A No. 2002-228803, Japanese Patent Application No. 2002-369679, Japanese Patent Application No. 2002-317883, and Japanese Patent Application No. 2003-50823. Alternatively, the antifouling layer can be provided by the method described in Japanese Patent Application No. 2003-50823. Alternatively, the antireflection layer can be applied by the method described in JP-A-2003-93963 and Japanese Patent Application No. 2002-49724.

On the hard coat film of the present invention, metal compounds (for example, SiO _x , SiO _x N _y , TiO _x N _y , SiO _x C _z (x = 1 to 2, y = It is preferable to form a thin film such as a metal oxide among metal oxides such as 0.1-1 and z = 0.1-2), metal nitrides, metal oxynitrides, metal carbides). The nitrogen gas contained in the gas is 60 to 99.9% by volume, preferably 75 to 99.9% by volume, and more preferably 90 to 99.9% by volume. In addition to nitrogen gas, a rare gas such as argon or helium may be contained, a gas of a metal compound for forming a thin film is contained, and further a gas (addition gas) for promoting a reaction such as oxygen and hydrogen. Or an auxiliary gas). By these, a low refractive index layer, a high refractive index layer, a medium refractive index layer, a transparent conductive layer, an antistatic layer, an antifouling layer and the like containing a metal compound can be formed.

  Next, the antireflection layer formed on these hard coat layers will be described.

(Antireflection layer)
In the present invention, the method for providing the antireflection layer is not particularly limited, and the antireflection layer can be formed by coating, sputtering, vapor deposition, CVD (Chemical Vapor Deposition), or a combination thereof.

  As a method of forming the antireflection layer by coating, a method of dispersing metal oxide powder in a binder resin dissolved in a solvent, coating and drying, a method of using a polymer having a crosslinked structure as a binder resin, ethylenic unsaturated Examples of the method include a method of forming a layer by containing a monomer and a photopolymerization initiator and irradiating actinic rays.

  In the present invention, an antireflection layer can be provided on the hard coat film provided with the hard coat layer. A low refractive index layer is formed on the uppermost layer of the hard coat film, a metal oxide layer of a high refractive index layer is formed between them, and a medium refractive index layer is further provided between the hard coat film and the high refractive index layer. It is preferable to provide (a metal oxide layer in which the refractive index is adjusted by changing the metal oxide content or the ratio with the resin binder and the type of metal) in order to reduce the reflectance. The refractive index of the high refractive index layer is preferably 1.55 to 2.30, and more preferably 1.57 to 2.20. The refractive index of the medium refractive index layer is adjusted so as to be an intermediate value between the refractive index (about 1.5) of the cellulose ester film as the substrate and the refractive index of the high refractive index layer. The refractive index of the middle refractive index layer is preferably 1.55-1.80. The thickness of each layer is preferably 5 nm to 0.5 μm, more preferably 10 nm to 0.3 μm, and most preferably 30 nm to 0.2 μm. The haze of the metal oxide layer is preferably 5% or less, more preferably 3% or less, and most preferably 1% or less. The strength of the metal oxide layer is preferably 3H or more, and most preferably 4H or more, with a pencil hardness of 1 kg. When the metal oxide layer is formed by coating, it is preferable to include inorganic fine particles and a binder polymer.

The inorganic fine particles used for the metal oxide layer such as the middle refractive index layer or the high refractive index layer preferably have a refractive index of 1.80 to 2.80, more preferably 1.90 to 2.80. . The primary particles of the inorganic fine particles preferably have a weight average diameter of 1 to 150 nm, more preferably 1 to 100 nm, and most preferably 1 to 80 nm. The weight average diameter of the inorganic fine particles in the layer is preferably 1 to 200 nm, more preferably 5 to 150 nm, still more preferably 10 to 100 nm, and most preferably 10 to 80 nm. . The average particle diameter of the inorganic fine particles is measured by a light scattering method if it is 20-30 nm or more and by an electron micrograph if it is 20-30 nm or less. The specific surface area of the inorganic fine particles, a measured value by the BET method, is preferably from 10 to 400 m ² / g, more preferably from 20 to 200 m ² / g, a 30 to 150 m ² / g Is most preferred.

  The inorganic fine particles are particles formed from a metal oxide. Examples of metal oxides or sulfides include titanium dioxide (eg, rutile, rutile / anatase mixed crystal, anatase, amorphous structure), tin oxide, indium oxide, ITO, zinc oxide, zirconium oxide, and the like. Of these, titanium dioxide, tin oxide, and indium oxide are particularly preferable. The inorganic fine particles are mainly composed of oxides of these metals and can further contain other elements. The main component means a component having the largest content (% by mass) among the components constituting the particles. Examples of other elements include Ti, Zr, Sn, Sb, Cu, Fe, Mn, Pb, Cd, As, Cr, Hg, Zn, Al, Mg, Si, P, and S.

  The inorganic fine particles are preferably surface-treated. The surface treatment can be performed using an inorganic compound or an organic compound. Examples of inorganic compounds used for the surface treatment include alumina, silica, zirconium oxide and iron oxide. Of these, alumina and silica are preferable. Examples of the organic compound used for the surface treatment include polyols, alkanolamines, stearic acid, silane coupling agents, and titanate coupling agents. Of these, a silane coupling agent is most preferable. It may be processed by combining two or more types of surface treatments.

  The shape of the inorganic fine particles is preferably a rice grain shape, a spherical shape, a cubic shape, a layer shape, a spindle shape, or an indefinite shape. Two or more kinds of inorganic fine particles may be used in combination in the metal oxide layer.

  The proportion of the inorganic fine particles in the metal oxide layer is preferably 5 to 90% by volume, more preferably 10 to 65% by volume, and still more preferably 20 to 55% by volume.

  The inorganic fine particles are supplied to a coating liquid for forming a metal oxide layer in a dispersion state dispersed in a medium. As the dispersion medium for the inorganic fine particles, a liquid having a boiling point of 60 to 170 ° C. is preferably used. Specific examples of the dispersion solvent include water, alcohol (eg, methanol, ethanol, isopropanol, butanol, benzyl alcohol), ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone), ester (eg, methyl acetate, ethyl acetate). , Propyl acetate, butyl acetate, methyl formate, ethyl formate, propyl formate, butyl formate), aliphatic hydrocarbons (eg, hexane, cyclohexane), aromatic hydrocarbons (eg, benzene, toluene, xylene), amides (eg, Dimethylformamide, dimethylacetamide, n-methylpyrrolidone), ether (eg, diethyl ether, dioxane, tetrahydrofuran), ether alcohol (eg, 1-methoxy-2-propanol), ketone alcohol (eg, diacetone alcohol) Lumpur, 3-hydroxy-3-methyl-2-butanone), and the like. Of these, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and butanol are particularly preferable.

  The inorganic fine particles can be dispersed in the medium using a disperser. Examples of the disperser include a sand grinder mill (eg, a bead mill with pins), a high-speed impeller mill, a pebble mill, a roller mill, an attritor, and a colloid mill. A sand grinder mill and a high-speed impeller mill are particularly preferred. Further, preliminary dispersion processing may be performed. Examples of the disperser used for the preliminary dispersion treatment include a ball mill, a three-roll mill, a kneader, and an extruder.

  The metal oxide layer preferably uses a polymer having a crosslinked structure (hereinafter also referred to as “crosslinked polymer”) as a binder polymer. Examples of the crosslinked polymer include polymers having a saturated hydrocarbon chain such as polyolefin (hereinafter collectively referred to as “polyolefin”), crosslinked products such as polyether, polyurea, polyurethane, polyester, polyamine, polyamide and melamine resin. Among them, a crosslinked product of polyolefin, polyether and polyurethane is preferred, a crosslinked product of polyolefin and polyether is more preferred, and a crosslinked product of polyolefin is most preferred. Moreover, it is more preferable that the crosslinked polymer has an anionic group. The anionic group has a function of maintaining the dispersion state of the inorganic fine particles, and the crosslinked structure has a function of imparting a film forming ability to the polymer and strengthening the film. The anionic group may be directly bonded to the polymer chain or may be bonded to the polymer chain via a linking group, but is bonded to the main chain as a side chain via the linking group. Is preferred.

  The refractive index of the low refractive index layer used in the antireflection layer of the present invention is preferably 1.46 or less, particularly preferably 1.3 to 1.45. Moreover, it is preferable that the low refractive index layer also serves as an antifouling layer. A low refractive index layer can be formed by a sol-gel method using silicon alkoxide as a coating composition. Alternatively, a low refractive index layer can be formed using a fluororesin. In particular, it is preferably composed of a cured product of thermosetting or ionizing radiation curable fluorine-containing resin and the cured product and ultrafine particles of silicon oxide.

  The dynamic friction coefficient of the cured product is preferably 0.02 to 0.2, and the pure water contact angle is preferably 90 to 130 °. Examples of the curable fluorine-containing resin include perfluoroalkyl group-containing silane compounds (for example, (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane) and fluorine-containing copolymers (crosslinkable groups). Monomer and fluorine-containing monomer as structural units). Specific examples of the fluorine-containing monomer unit include, for example, hexafluoroethylene, hexafluoropropylene, tetrafluoroethylene, and fluoroolefins (for example, vinylidene fluoride perfluoro-2,2-dimethyl-1,3-dioxole, fluoroethylene, etc.) , Fluorinated alkyl ester derivatives of (meth) acrylic acid (for example, Biscoat 6FM (manufactured by Osaka Organic Chemicals) and M-2020 (manufactured by Daikin)), fluorinated vinyl ethers, and the like. As a monomer having a crosslinkable group, a (meth) acrylate monomer having a crosslinkable functional group in the molecule in advance such as glycidyl methacrylate, and a (meth) acrylate having a carboxyl group, an amino group, a hydroxyl group, a sulfonic acid group, etc. And monomers (for example, (meth) acrylic acid, methylol (meth) acrylate, hydroxyalkyl (meth) acrylate, allyl acrylate, etc.). It is described in JP-A-10-25388 and JP-A-10-147739 that a crosslinked structure can be introduced after copolymerization.

  Moreover, not only the polymer which uses the said fluorine-containing monomer as a structural unit but the copolymer with the monomer which does not contain a fluorine atom can be used. There are no particular limitations on the monomer units that can be used in combination, for example, acrylic esters (methyl acrylate, methyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate), methacrylate esters (methyl methacrylate, ethyl methacrylate, Butyl methacrylate, ethylene glycol dimethacrylate, etc.), styrene derivatives (styrene, divinylbenzene, α-methylstyrene, vinyltoluene, etc.), acrylamides (N-tertbutylacrylamide, N-cyclohexylacrylamide, etc.), methacrylamides, acrylonitrile Derivatives, olefins (ethylene, propylene, isoprene, vinylidene chloride, vinyl chloride, etc.), vinyl ethers (methyl vinyl ether, etc.), vinyl esters (vinyl acetate, propionic acid) Alkenyl, vinyl cinnamate) may be mentioned.

  In order to improve the scratch resistance, it is preferable to add silicon oxide fine particles to the fluorine-containing resin used for forming the low refractive index layer. The addition amount is adjusted in consideration of the refractive index and scratch resistance. As the silicon oxide fine particles, silica sol dispersed in a commercially available organic solvent can be added to the coating composition as it is, or various commercially available silica powders can be dispersed in an organic solvent and used.

  The coating composition for forming a low refractive index layer of the antireflection film of the present invention preferably contains a solvent having a low boiling point mainly. Specifically, the solvent having a boiling point of 100 ° C. or less is preferably 50% by mass or more of the total solvent. As a result, even when coated on the surface of a substrate having irregularities such as an antiglare layer, it can be dried quickly, fine film thickness unevenness due to the flow of the coating liquid is reduced, and an increase in reflectance is suppressed. The Moreover, since the drying nonuniformity and white turbidity nonuniformity are suppressed when the solvent whose boiling point is 100 degreeC or more is contained, it is preferable that the solvent whose boiling point is 100 degreeC or more contains 0.1-50 mass%.

  Low boiling point solvents used in coating compositions for the low refractive index layer include ketones such as acetone and methyl ethyl ketone, esters such as methyl acetate and ethyl acetate, ether alcohols such as methyl cellosolve, methanol, ethanol, and isopropanol. Among such alcohols, those having high solubility of the solid content contained in the coating composition are preferably used. Coating solvents having a boiling point exceeding 100 ° C. include ketones such as cyclohexanone, cyclopentanone and methyl-isobutyl ketone, ether alcohols such as diacetone alcohol and propylene glycol monomethyl ether, and alcohols such as 1-butanol and 2-butanol. Etc. are used.

  Each layer of the antireflection film can be formed by coating by dip coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, micro gravure coating or extrusion coating. I can do it.

  In the present invention, a method of forming a metal oxide layer by plasma discharge treatment can also be preferably used.

  Hereinafter, a method for forming a metal oxide layer by plasma discharge treatment will be described with reference to FIGS.

  Plasma discharge treatment under atmospheric pressure or a pressure in the vicinity thereof as a method for forming a metal oxide layer on the hard coat film of the present invention is performed by using a plasma discharge treatment apparatus as described below.

  FIG. 1 is a view showing an example of a plasma discharge treatment apparatus used for forming a metal oxide layer on the hard coat film of the present invention.

  In FIG. 1, this apparatus has a pair of rotating electrodes 10A and 10B. A power supply 80 to which a voltage for generating plasma discharge can be applied is connected to the rotating electrodes 10A and 10B. Connected to ground, 82 is connected to ground.

  The rotating electrodes 10A and 10B are conveyed while winding the hard coat film, and are preferably roll electrodes or belt-like electrodes, and FIG. 1 shows the roll electrodes.

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

  The gap between the electrodes is maintained at atmospheric pressure or a pressure close to atmospheric pressure. The reaction gas G is supplied from the reaction gas supply unit 30 and the surface of the hard coat film F is subjected to plasma discharge treatment.

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

  The hard coat film F that has once exited from the discharge section 50 is U-turned by the U-turn rolls 11A to 11D, and this time, the hard coat film F contacts the rotating electrode 10B rotating in the opposite direction to the rotating electrode 10A. The thin film is further formed by plasma discharge treatment on the surface of the hard coat film F on which the thin film has been formed. The U-turn is usually performed in about 0.1 seconds to 1 minute.

  The reaction gas G used for the treatment is discharged from the gas discharge port 40 as exhaust gas G ′ after the reaction. It is preferable that the reaction gas G is heated to room temperature to 250 ° C., preferably 50 to 150 ° C., more preferably 80 to 120 ° C., and then fed into the discharge part 50.

  In addition, it is preferable that the discharge part 50 is provided with the rectification | straightening board 51, and while making the flow of the reaction gas G and waste gas G 'smooth, the discharge part 50 spreads and unnecessary discharge is made between electrodes 10A and 10B. The rectifying plate 51 is preferably made of an insulating member.

  In the figure, the thin film formed on the hard coat film F is omitted. The hard coat film F having a thin film formed on the surface is conveyed in the direction of the next process or a take-up roll (not shown) via the guide roller 21.

  Therefore, the hard coat film F is subjected to plasma discharge treatment by reciprocating the discharge portion 50 in a state of being in close contact with the rotary electrodes 10A and 10B.

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

  Although not shown, a temperature control medium for controlling the temperature of the rotating electrodes 10A and 10B is circulated as necessary to control each electrode surface temperature to a predetermined value. . The diameters of the rotating electrodes 10A and 10B are 10 to 1000 mm, preferably 50 to 500 mm, and those having different diameters may be used in combination.

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

  A rotating electrode 110 and a plurality of fixed electrodes 111 arranged opposite to the rotating electrode 110 and a hard coat film F conveyed from a not-shown original winding roll or a previous process pass through a guide roll 120 and a nip roll 122 to rotate the rotating electrode 110, the hard coat film F is transferred in synchronization with the rotation of the rotating electrode 110 while being in contact with the rotating electrode 110, and is supplied to the discharge unit 150 under the atmospheric pressure or in the vicinity thereof by the reaction gas generator 131. The prepared reaction gas G is supplied from the supply pipe 130, and a thin film is formed on the hard coat film surface facing the fixed electrode 111.

  A power source 180 capable of applying a voltage for generating plasma discharge is connected to the voltage supply means 181 between the rotating electrode 110 and the fixed electrode, one of which is connected to the ground, and 182 is connected to the ground.

  Further, the rotating electrode 110, the fixed electrode 111, and the discharge unit 150 are covered with a plasma discharge processing vessel 190 and are shielded from the outside. The treated exhaust gas G ′ is discharged from a gas exhaust port 140 at the lower part of the processing chamber.

  The hard coat film F subjected to the plasma discharge treatment is conveyed to the next process or a winding roll (not shown) through the nip roll 123 and the guide roll 121.

  Partition plates 124 and 125 with the outside world are provided at the nip rolls 122 and 123 at the entrance and exit of the plasma discharge processing container, and air accompanying the hard coat film F from the outside world together with the nip rolls 122 is provided. At the outlet, the reaction gas G or the exhaust gas G ′ is prevented from leaking to the outside. Although not shown, the rotating electrode 110 and the fixed electrode 111 may be temperature controlled as required. A temperature-controlled medium is circulated in the interior.

  Thus, in the present invention, the hard coat film on which the thin film is formed is preferably subjected to plasma discharge treatment while being transferred on the rotating electrode.

  The surface where the rotating electrode is in contact with the hard coat film is required to have high smoothness, and the surface roughness of the surface of the rotating electrode is the maximum surface roughness (Rmax) defined by JIS-B-0601 of 10 μm or less. More preferably, it is 8 micrometers or less, Most preferably, it is 7 micrometers or less. In addition, it is necessary to prevent dust and foreign matter from adhering to the electrodes for uniform film formation.

The surface of the electrode used for the plasma discharge treatment is preferably coated with a solid dielectric, and in particular, a conductive base material such as a metal is preferably coated with the solid dielectric. Examples of the solid dielectric include plastics such as polytetrafluoroethylene and polyethylene terephthalate, metal oxides such as glass, silicon dioxide, aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), and titanium oxide (TiO ₂ ). Examples thereof include double oxides such as barium titanate.

  Particularly preferred is a ceramic-coated dielectric that has been subjected to sealing treatment using an inorganic material after thermal spraying of ceramics. Here, examples of the conductive base material such as metal include metals such as silver, platinum, stainless steel, aluminum, and iron. Stainless steel is preferable from the viewpoint of processing.

  As the lining material, silicate glass, borate glass, phosphate glass, germanate glass, tellurite glass, aluminate glass, vanadate glass, etc. are preferably used. However, among these, borate glass is more preferably used because it is easy to process.

  The electrode used for the plasma discharge treatment can be heated or cooled as necessary from the back side (inside). When the electrode is a belt, it can be cooled with gas from the back side, but it is preferable to control the temperature of the electrode surface and the temperature of the hard coat film by supplying a medium inside the rotating electrode using a roll. .

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

  The temperature of the hard coat film during the discharge treatment varies depending on the treatment conditions, but is preferably room temperature to 200 ° C. or less, more preferably room temperature to 120 ° C. or less, and further preferably 50 to 110 ° C.

  It is desirable to prevent temperature unevenness particularly in the width direction of the hard coat film surface during the discharge treatment, preferably within ± 5 ° C, more preferably within ± 1 ° C, and particularly 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 using plasma, and the like. The shortest distance between the solid dielectric and the electrode when a solid dielectric is placed on one of the electrodes, and the distance between the solid dielectrics when a solid dielectric is placed on both of the electrodes is uniform in any case From the viewpoint of generating discharge plasma, 0.5 mm to 20 mm is preferable, and 1 mm ± 0.5 mm is particularly preferable.

  In the present invention, the flow rate of the mixed gas generated by the gas generator is controlled in the discharge portion of the electrode gap and introduced into the plasma discharge portion from 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 to the electrode gap at a speed sufficient for the transport speed of the hard coat film. In the discharge section, it is desirable to set the flow rate and discharge conditions so that most of the supplied reaction gas reacts and is used for thin film formation.

  In order to prevent the atmosphere from being mixed into the discharge part and the reaction gas from leaking out of the apparatus, it is preferable that the electrode and the hard coat film being transferred are surrounded and shielded from the outside. In the present invention, the atmospheric pressure of the discharge part is maintained at atmospheric pressure or a pressure in the vicinity thereof. In addition, the reaction gas may be decomposed in the gas phase to generate metal oxide fine powder, and it is desirable to set the flow rate and discharge conditions so as to reduce the generation.

  Here, the vicinity of atmospheric pressure represents a pressure of 20 to 200 kPa, but 93 to 110 kPa is preferable in order to preferably obtain the effects described in the present invention. The discharge part is preferably slightly positive with respect to the atmospheric pressure outside the apparatus, more preferably atmospheric pressure outside the plasma apparatus +0.1 kPa to 5 kPa.

  In the plasma discharge treatment apparatus useful for the present invention, it is preferable that one electrode is connected to a power source to apply a voltage, and the other electrode is grounded to generate a discharge plasma to generate a stable plasma. .

  The value of the voltage applied to the electrode from the high frequency power source used in the present invention is appropriately determined. For example, the voltage is about 0.5 to 10 kV, the applied frequency is adjusted to 1 kHz to 150 MHz, and the waveform is a pulse wave. Or a sine wave. In particular, it is preferable to apply a high frequency exceeding 100 kHz and not exceeding 50 MHz because a discharge part (discharge space) is preferably obtained. Alternatively, a method of simultaneously applying high-frequency voltages having two frequencies of 1 kHz to 200 kHz and 800 kHz to 150 MHz is also preferably used.

Preferably the discharge density in the discharge portion are 5~1000W · min / m ^2, in particular it is desirable that 50~500W · min / m ^2.

  It is desirable that the plasma discharge processing section is appropriately surrounded by a Pyrex (R) glass processing container or the like, and it is also possible to use a metal as long as it is insulated from the electrodes. For example, polyimide resin or the like may be affixed to the inner surface of an aluminum or stainless steel frame, and the metal frame may be thermally sprayed to obtain insulation. In addition, the reaction gas and the exhaust gas can be appropriately supplied to the discharge unit or exhausted by surrounding the discharge unit, the side surface of the rotating electrode, the side surface of the cellulose ester film transport unit and the like.

  The reaction gas used in the method for forming a metal oxide 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 noble gas is a group 18 element of the periodic table, specifically helium, neon, argon, krypton, xenon, radon, etc., and in the present invention, helium or argon is preferably used. I can do it. These may be used as a mixture, for example, in a ratio of helium 3: argon 7 or the like.

  The concentration of the rare gas or nitrogen in the reaction gas is preferably 90% or more in order to generate a stable plasma discharge, and desirably 90 to 99.99% by volume.

  A rare gas or nitrogen is used to generate a stable plasma discharge, and the reactive gas is ionized or radicalized in the plasma, and is deposited or adhered to the surface of the substrate to form a thin film.

  The reactive gas useful in the present invention can form thin films having various functions on a hard coat film by using a reactive gas added with reactive gases of various substances.

  For example, the low refractive index layer or the antifouling layer of the antireflection layer can be formed using a fluorine-containing organic compound or a silicon compound as the reactive gas.

  Further, these metal oxide layers (metal oxide nitride layers) using organometallic compounds, metal hydrides, and metal halides containing Ti, Zr, In, Sn, Zn, Ge, Si or other metals. Or a metal nitride layer or the like, and these layers may be a refractive index layer or a high refractive index layer among antireflection layers, or may be a conductive layer or an antistatic layer.

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

  The film thickness of the formed metal oxide layer is preferably in the range of 1 nm to 1000 nm.

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

  As the fluorine-containing organic compound, a fluorocarbon gas, a fluorinated hydrocarbon gas, or the like is preferable.

Specifically, as the fluorine-containing organic compound, for example, a fluorocarbon compound such as carbon tetrafluoride, carbon hexafluoride, tetrafluoroethylene, hexafluoropropylene, and octafluorocyclobutane;
Fluorinated hydrocarbon compounds such as difluoromethane, tetrafluoroethane, propylene tetrafluoride, propylene trifluoride, and cyclobutane octafluoride;
Further, halides of fluorinated hydrocarbon compounds such as trichloromethane trichloride, methane monochloride difluoride methane, and cyclobutane tetrachloride difluoride, and fluorine-substituted products of organic compounds such as alcohols, acids, and ketones. I can do it.

  These may be used alone or in combination. Examples of the fluorinated hydrocarbon gas include gases such as difluoromethane, tetrafluoroethane, propylene tetrafluoride, and propylene trifluoride.

  Furthermore, it is possible to use halides of fluorinated hydrocarbon compounds such as monochlorotrifluoride methane, monochlorodifluoride methane, and dichloride tetrafluorocyclobutane, and fluorine-substituted products of organic compounds such as alcohols, acids, and ketones. However, the present invention is not limited to these.

  Further, these compounds may have an ethylenically unsaturated group in the molecule. Moreover, you may use said compound in mixture.

  When a fluorine-containing organic compound is used as the reactive gas, the content of the fluorine-containing organic compound as the reactive gas in the reactive gas is from the viewpoint of forming a uniform thin film on the cellulose ester film by plasma discharge treatment. It is preferable that it is 01-10 volume%, More preferably, it is 0.1-5 volume%.

  Further, when the fluorine-containing organic compound that is preferably used is a gas at normal temperature and pressure, it can be used as it is as a component of the reactive gas.

  Further, when the fluorine-containing organic compound is liquid or solid at normal temperature and normal pressure, it may be used after being vaporized by vaporization means, for example, by heating, reduced pressure, or the like, and may be used after being dissolved in an appropriate organic solvent. .

  Examples of silicon compounds useful as reactive gases include organometallic compounds such as dimethylsilane and tetramethylsilane, metal hydrides such as monosilane and disilane, metal halogens such as silane dichloride, silane trichloride, and silicon tetrafluoride. Compounds, tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, dimethyldiethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, hexamethyldisiloxane and other alkoxysilanes, organosilanes, etc. are preferably used. It is not limited.

  Moreover, these can be used in combination as appropriate. Alternatively, another organic compound can be added to change or control the physical properties of the film.

  When a silicon compound is used as the reactive gas, the content of the silicon compound as the reactive gas in the reactive gas is 0.01 to 10 volumes from the viewpoint of forming a uniform thin film on the cellulose ester film by plasma discharge treatment. %, Preferably 0.1 to 5% by volume.

  Although it does not specifically limit as an organometallic compound useful as a reactive gas, Al, As, Au, B, Bi, Sb, Ca, Cd, Cr, Co, Cu, Fe, Ga, Ge, Hg, In, Li Preferable organic metal compounds for forming metal compounds such as Mg, Mn, Mo, Na, Ni, Pb, Pt, Rh, Se, Si, Sn, Ti, Zr, Y, V, W, and Zn I can do it.

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

  The above silicon compounds and organometallic compounds are preferably metal hydrides and metal alkoxides from the viewpoint of handling, and are preferably used since metal alkoxides are not corrosive, do not generate harmful gases, and have little contamination in the process. It is done.

  When using an organometallic compound as the reactive gas, from the viewpoint of forming a uniform thin film on the cellulose ester film by plasma discharge treatment, the content of the organometallic compound as the reactive gas in the reactive gas is 0.01 to Although it is preferable that it is 10 volume%, More preferably, it is 0.1-5 volume%.

  Further, in order to introduce a metal compound such as a silicon compound or a titanium compound into the discharge part, both can 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 after being vaporized by means of vaporization such as heating, decompression or ultrasonic irradiation.

  When metal compounds such as silicon compounds and titanium compounds are vaporized by heating, metal alkoxides that are liquid at room temperature and have a boiling point of 200 ° C. or less, such as tetraethoxysilane and tetraisopropoxytitanium, are used in the present invention. It is suitable for a method for forming a metal oxide thin film layer. The metal alkoxide may be used after diluted with an organic solvent. As the organic solvent, an organic solvent such as methanol, ethanol, n-hexane, or a mixed organic solvent thereof can be used.

  Furthermore, physical properties such as hardness and density of the thin film layer can be obtained by adding 0.1 to 10% by volume of oxygen, hydrogen, carbon dioxide, carbon monoxide, nitrogen, nitrogen dioxide, nitrogen monoxide, water, etc. in the reaction gas. Can be controlled.

  By the above method, an amorphous metal oxide layer such as silicon oxide or titanium oxide can be preferably produced.

  The hard coat film of the present invention can be preferably used for, for example, an optical film having an antireflection layer obtained by laminating a low refractive index layer and a high refractive index layer, a conductive layer, an optical film having an antistatic layer, or the like.

  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 producing an antireflection film having an antireflection layer on a hard coat film, a high refractive index layer having a refractive index of 1.6 to 2.3 and a low refractive index layer having a refractive index of 1.3 to 1.5 are provided. The cellulose ester film can be continuously laminated on the surface and efficiently produced.

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

  Although there are thinning methods described above, the present invention is not limited to these methods, and the layer structure is not limited thereto. For example, an antifouling layer may be provided on the outermost surface by plasma discharge treatment in the presence of a fluorine-containing organic compound gas in the presence of atmospheric pressure or in the vicinity thereof.

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

<Polarizer>
The polarizing plate of the present invention will be described.

  The polarizing plate can be produced by a general method. The back side of the hard coat film of the present invention is subjected to alkali saponification treatment, and the treated hard coat film is completely saponified on at least one surface of a polarizing film prepared by immersing and stretching a stretched polyvinyl alcohol film in an iodine solution. It is preferable to bond using an aqueous polyvinyl alcohol solution. The hard coat film may be used on the other surface, or another polarizing plate protective film may be used. The polarizing plate protective film used on the other surface of the hard coat film of the present invention has an in-plane retardation Ro of 590 nm, a phase difference of 20 to 70 nm, and Rt of 100 to 400 nm. preferable. These can be produced, for example, by the method described in JP-A-2002-71957 and Japanese Patent Application No. 2002-155395. Alternatively, it is preferable to use a polarizing plate protective film that also serves as an optical compensation film having an optically anisotropic layer formed by aligning a liquid crystal compound such as a discotic liquid crystal. For example, the optically anisotropic layer can be formed by the method described in JP-A-2003-98348. By using in combination with the hard coat film of the present invention, a polarizing plate having excellent flatness and a stable viewing angle expansion effect can be obtained.

  The polarizing film, which is the main component of the polarizing plate, is an element that transmits only light having a polarization plane in a certain direction. A typical polarizing film known at present is a polyvinyl alcohol polarizing film, which is a polyvinyl alcohol film. There are one in which iodine is dyed on a system film and one in which dichroic dye is dyed. As the polarizing film, a polyvinyl alcohol aqueous solution is formed and dyed by uniaxially stretching or dyed, or uniaxially stretched after dyeing, and then preferably subjected to a durability treatment with a boron compound. On the surface of the polarizing film, one side of the hard coat film of the present invention is bonded to form a polarizing plate. It is preferably bonded with an aqueous adhesive mainly composed of completely saponified polyvinyl alcohol or the like.

  A polarizing plate using a conventional hard coat film is inferior in flatness, and when a reflected image is seen, fine wavy irregularities are recognized, and a pencil hardness of only about 2H is obtained, under conditions of 60 ° C. and 90% RH. As a result of the durability test, the wavy unevenness increased. On the other hand, the polarizing plate using the hard coat film of the present invention was excellent in flatness and pencil hardness. Further, even in the durability test under the conditions of 60 ° C. and 90% RH, the wavy unevenness did not increase.

  In addition, the polarizing plate produced using the hard coat film of the present invention is less likely to be broken by cutting at the end when cutting even though it is excellent in hardness, and the occurrence of failure due to chips is also reduced. It was also excellent in workability.

<Display device>
By incorporating the polarizing plate of the present invention into a display device, the display device of the present invention having various visibility can be manufactured. The hard coat film of the present invention is a reflective type, transmissive type, transflective type LCD, or TN type, STN type, OCB type, HAN type, VA type (MVA type, PVA type), IPS type, etc. Preferably used. In addition, the antireflection film in which the antireflection layer is formed on the hard coat film of the present invention has significantly less color unevenness in the reflected light of the antireflection layer, and is excellent in flatness, plasma display, field emission display, organic EL display, It is also preferably used for various display devices such as inorganic EL displays and electronic paper. Especially in a large-screen display device with a 30-inch screen or more, a reflection image of a fluorescent lamp that appears to be distorted due to uneven color or undulation is not distorted like the reflection of a mirror. But there was an effect that eyes were not tired.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example 1
[Production of cellulose ester film]
A cellulose ester solution was prepared using the cellulose ester, plasticizer, ultraviolet absorber, fine particles, and solvent described in Table 1 so as to have a dope composition as shown in Table 2.

  That is, the solvent was put into an airtight container, the remaining materials were put in order while stirring, and completely dissolved and mixed while heating and stirring. The fine particles were added dispersed in a part of the solvent. After the temperature was lowered to the temperature at which the solution was cast and allowed to stand overnight, a defoaming operation was performed, and then the solution was produced by Azumi Filter Paper No. Filtration using 244 gave each cellulose ester solution.

  Next, the cellulose ester solution whose temperature was adjusted to 33 ° C. was fed to a die and uniformly cast from a die slit onto a stainless steel belt. The cast part of the stainless steel belt was heated from the back with hot water of 37 ° C. After casting, the dope film on the metal support (which will be referred to as the web after casting on the stainless steel belt) is dried by applying hot air of 44 ° C., and the residual solvent amount during peeling is 120% by mass. Then, the film was stretched so as to have a predetermined longitudinal stretching ratio by applying tension at the time of peeling, and then the web end was gripped by a tenter, and stretched to the stretching ratio shown in the table in the width direction. After stretching, the width is maintained for several seconds, then the tension in the width direction is relaxed, then the width is released, and further transported for 20 minutes in the third drying zone set at 125 ° C. for drying. A cellulose ester film No. 1 having a predetermined film thickness having a width of 1.4 to 2 m and a knurling of 1.5 cm in width and 8 μm in height at the end. 1-27 were produced.

  About each produced cellulose-ester film, the cellulose ester used, the plasticizer, the ultraviolet absorber, etc., the draw ratio of the web, the film thickness of the produced film, and the film-forming width are summarized in Table 2.

[Production of intermediate layer coated film]
Among the cellulose ester films, No. On the surface of 1 cellulose ester film, the following intermediate layer coating composition was prepared by filtering using a filter having a particle capture efficiency of 3 μm of 99% or more and a particle capture efficiency of 0.5 μm or less of 10% or less. . These coating compositions (1) to (19) were applied with an extrusion coater so that the wet film thickness was 15 μm, dried at 90 ° C. for 30 seconds, and the intermediate layer coated film No. 1-19 were obtained.

  Moreover, about coating composition (3) and (4), it apply | coated so that the wet film thickness might be 3 micrometers and 70 micrometers, and each intermediate | middle layer coat film No.1. 20, 21 (both 3 μm) and No. 22 and 23 (both 70 μm) were obtained.

  Further, the coating composition (7) was coated with a wet film thickness of 15 μm, and the coating composition (8) was coated with a wet film thickness of 15 μm. 24 was obtained.

Coating composition (1)
Methyl ethyl ketone 20 parts by weight Methanol 40 parts by weight Isopropyl alcohol 40 parts by weight Coating composition (2)
Methyl ethyl ketone 80 parts by weight Methanol 20 parts by weight Coating composition (3)
Acetone 30 parts by weight Methanol 30 parts by weight Propylene glycol monomethyl ether 40 parts by weight Coating composition (4)
Acetone 60 parts by weight Methanol 40 parts by weight Coating composition (5)
Acetone 90 parts by weight Methanol 10 parts by weight Coating composition (6)
Diacetylcellulose (acetyl group substitution degree 2.4) 1 part by weight Acetone 30 parts by weight Methanol 30 parts by weight Propylene glycol monomethyl ether 40 parts by weight Coating composition (7)
Diacetyl cellulose (acetyl group substitution degree 2.4) 1 part by weight Acetone 60 parts by weight Methanol 40 parts by weight Coating composition (8)
Thermoplastic acrylic resin (Dianar BR-108 (Mitsubishi Rayon Co., Ltd.))
1 part by weight Acetone 30 parts by weight Methanol 30 parts by weight Propylene glycol monomethyl ether 40 parts by weight Coating composition (9)
Thermoplastic acrylic resin (Dianar BR-108 (Mitsubishi Rayon Co., Ltd.))
1 part by weight Acetone 60 parts by weight Methanol 40 parts by weight Coating composition (10)
Cellulose propionate (total substitution degree 2.69) 1 part by weight Acetone 30 parts by weight Methanol 30 parts by weight Propylene glycol monomethyl ether 40 parts by weight Coating composition (11)
Cellulose propionate (total substitution degree 2.69) 1 part by weight Acetone 60 parts by weight Methanol 40 parts by weight Coating composition (12)
Diacetylcellulose (acetyl group substitution degree 2.4) 0.5 parts by mass Thermoplastic acrylic resin (Dianar BR-108 (Mitsubishi Rayon Co., Ltd.))
0.5 parts by weight Acetone 30 parts by weight Methanol 30 parts by weight Propylene glycol monomethyl ether 40 parts by weight Coating composition (13)
Diacetylcellulose (acetyl group substitution degree 2.4) 0.5 parts by mass Thermoplastic acrylic resin (Dianar BR-108 (Mitsubishi Rayon Co., Ltd.))
0.5 parts by weight Acetone 60 parts by weight Methanol 40 parts by weight Coating composition (14)
Acetone 10 parts by weight Methanol 20 parts by weight Isopropyl alcohol 70 parts by weight Coating composition (15)
Methyl ethyl ketone 100 parts by weight Coating composition (16)
Triacetylcellulose (acetyl group substitution degree 2.85) 1 part by weight Methyl acetate 30 parts by weight Methanol 30 parts by weight Propylene glycol monomethyl ether 40 parts by weight Coating composition (17)
Triacetyl cellulose (acetyl group substitution degree 2.85) 1 part by weight Methyl acetate 60 parts by weight Methanol 40 parts by weight Coating composition (18)
Thermoplastic acrylic resin (Dianar BR-108 (Mitsubishi Rayon Co., Ltd.))
1 part by weight Acetone 10 parts by weight Methanol 20 parts by weight Isopropyl alcohol 70 parts by weight Coating composition (19)
Diacetyl cellulose (acetyl group substitution degree 2.4) 1 part by weight Methyl ethyl ketone 100 parts by weight [Preparation of hard coat film]
<< Coating of hard coat layer / back coat layer >>
Intermediate layer coat film No. The following coating liquid for hard coat layer (ultraviolet curable resin layer) is filtered through a polypropylene filter having a pore diameter of 0.4 μm on the intermediate layer 1 to 24 and on the surface of the cellulose ester film on which the intermediate layer is not coated. Then, a hard coat layer coating solution is prepared, applied using an extrusion coater, dried at 90 ° C. for 30 seconds, and then irradiated using an ultraviolet lamp with an illuminance of 120 mW / cm ² and an irradiation amount of 100 mJ / cm 2. ^The coating layer was cured as ² to form a hard coat layer having a thickness of 6 μm.

  Furthermore, the following coating composition for a back coat layer was prepared by filtering with a filter having a particle capture efficiency of 3 μm of 99% or more and 0.5 μm or less of particle capture efficiency of 10% or less. This back coat layer coating composition was applied to the surface opposite to the surface coated with the hard coat layer of the film coated with the above hard coat layer with an extrusion coater so that the wet film thickness was 15 μm. And dried at 90 ° C. for 30 seconds.

  In this way, the hard coat film No. 1 described in Table 3 was used. 1-25 were produced.

<Coating liquid for hard coat layer>
Dipentaerythritol hexaacrylate 100 parts by weight Photoreaction initiator 4 parts by weight (Irgacure 184 (Ciba Specialty Chemicals Co., Ltd.))
Ethyl acetate 75 parts by mass Propylene glycol monomethyl ether 75 parts by mass Silicon compound 0.5 parts by mass (BYK-307 (by Big Chemie Japan))
<Coating liquid for back coat layer>
Diacetylcellulose (acetyl group substitution degree 2.4) 0.5 parts by mass Acetone 70 parts by mass Methanol 20 parts by mass Propylene glycol monomethyl ether 10 parts by mass Ultrafine silica Aerosil 200 (produced by Nippon Aerosil Co., Ltd.) 0.002 parts by mass

[Evaluation]
The following evaluation was performed about the obtained optical film.

《Scratch resistance》
The steel wool # 0000, the surface of the hard coat layer was 10 reciprocations while applying a load of 1000 g, is adhered black tape on the back, was visually observed the presence or absence of the occurrence of scratches in the green lamp, area 1 cm ² per The number of wounds was determined.

"Pencil hardness"
Using pencils with different hardnesses, a hardness test was performed based on the test method shown in JIS K5400 under a load of 1 kg. Each hard coat film was divided into 10 in the width direction, and the pencil hardness at each position was measured.

《Tear test》
In order to evaluate the peeling and cracking of the hard coat layer of the optical film, a tear test was performed.

  After making a 2mm incision on one side of a 5cm x 5cm piece with an NT cutter, the hard coat surface is placed in front and the tear direction is set to tear direction 1, and the hard coat surface is placed on the back side and torn to the front side. Is the tear direction 2. The torn edge of the film that has been torn three times in two directions of tear direction 1 and tear direction 2 is observed with a × 10 loupe.

◎: No peeling of hard coat layer on the tearing edge, no edge raising ○: No more than 2 out of 3 times, partial tearing on the tearing edge △: Partially raised edge on the tearing edge ×: 3 No more than 2 times of hard coat layer peeling XX: Hard coat layer peeling for all 3 times << Flatness index; Evaluation of minute unevenness >>
Laser displacement meter: Keyence Corporation, Model: LT-8100, Resolution: 0.2 μm, Scan with a laser displacement meter in the width direction to measure fine undulations on the surface, flatness of hard coat film Evaluated.

  The measuring method is that the film is placed on a flat and horizontal table, both ends of the width are fixed to the table with tape, and the measuring camera is set in parallel with the table on a moving rail made by Sigma Kogyo Co., Ltd. And the sample film were set so that the distance between them was 25 mm, and the measurement was performed by scanning at a moving speed of 5 cm / min. The value obtained by the measurement is the state and size of minute irregularities on the film surface.

A: Unevenness due to film deformation is less than 0.5 μm ○: Unevenness due to film deformation is less than 0.5 to 1.0 μm Δ: Unevenness due to film deformation is less than 1.0 to 3.0 μm ×: Due to film deformation Unevenness is 3.0 μm or more <<Flatness; Visual evaluation >>
Cut each sample into a size of 90cm in width and 100cm in length, and arrange five 50W fluorescent lamps at a height of 1.5m so that the sample stage can be illuminated from a 45 ° angle. Each film sample was placed, and the unevenness that appeared to be reflected on the film surface was visually observed and judged as follows. By this method, it is possible to determine “tsun” and “wrinkle”.

◎: All five fluorescent lamps looked straight ○: Fluorescent lamps appear to be bent slightly △: Fluorescent lamps appear to be slightly bent as a whole ×: Fluorescent lamps appear to swell significantly Hard coat film No. The evaluation results for 1 to 25 are shown in Table 4 below.

  From the table, an intermediate layer containing 20, 30, 60, 80, 90% by volume of the swelling solvent of the cellulose ester film in the coating composition solvent is coated with a wet film thickness of 15 μm between the hard coat layer and the cellulose ester film. The hard coat film No. 1 of the present invention. It was confirmed that Nos. 1 to 5 were compatible with scratch resistance, pencil hardness, tear resistance, and flatness. In particular, the hard coat film No. having a swelling ratio of 30, 60, 80% by volume of cellulose ester film swelling solvent. 2 to 4 had a pencil hardness of 4H and were good. Comparative hard coat film No. having no intermediate layer Comparative Example Hard Coat Film No. 25 having a volume ratio of the swelling solvent of the cellulose ester film in the coating composition solvent having the intermediate layer 25 and the intermediate layer. Nos. 14 and 18 show comparative examples of hard coat film No. 1 in which the hard coat layer was peeled off at the tear portion in the tear test, and the intermediate layer was coated only with the swelling solvent of the cellulose ester film in the coating composition solvent. 15 and 19 were unfavorable values for both scratch resistance and flatness. In addition, even if the coating composition solvent has an intermediate layer containing 30 to 60% of the swelling solvent of the cellulose ester film in a volume ratio, the comparative hard coat film No. 3 having a wet film thickness of 3 μm. Nos. 20 and 21 are comparative examples of a hard coat film No. 1 in which the hard coat layer peeled off at the tear portion in the tear test and the wet film thickness was 70 μm. Nos. 22 and 23 were undesirable physical properties due to inferior scratch resistance and flatness.

  In addition, the hard coat film No. 1 of the present invention having a binder in the intermediate layer. Nos. 6 to 11 have both scratch resistance, pencil hardness, tear resistance, and flatness. The hard coat film No. 1 of the present invention in which cellulose ester and polymethyl methacrylate are used in combination. 12 and 13 were also good. The present hard coat film No. 1 using diacetyl cellulose having a substitution degree of 2.4 as an intermediate layer binder. Nos. 6 and 7 of the present invention using cellulose propionate having a total substitution degree of 2.69. Nos. 10 and 11 show the hard coat film No. 1 of the present invention using triacetyl cellulose having an acetyl group substitution degree of 2.85. The tear test is better than 16, 17, and when the cellulose ester binder is used, it is better that the substitution degree of the intermediate layer binder is 0.1 or more smaller than the substitution degree of the cellulose ester used for the substrate. It was proved.

  Furthermore, the present hard coat film No. 2 having two intermediate layers was provided. 24 was also found to have good scratch resistance, tear resistance, and flatness.

  In addition, the hard coat film No. of the present invention. 1-13, no. 16, no. 17, no. The 24 hard coat film had no interference unevenness and excellent optical characteristics.

[Preparation of antireflection film]
An antireflection layer was formed on the hard coat film produced above.

  The hard coat film No. The following medium refractive index layer coating solution is applied onto 1 to 25 using a bar coater, dried at 70 ° C., then irradiated with ultraviolet rays to cure the coating layer, and the medium refractive index layer (refractive index 1). 72, film thickness 80 nm). On top of that, the following coating solution for a high refractive index layer was applied using a bar coater, dried at 70 ° C., then irradiated with ultraviolet rays to cure the coating layer, and a high refractive index layer (refractive index 1.9, A film thickness of 70 nm) was formed. Furthermore, the following coating solution for the low refractive index layer is applied using a bar coater, dried at 70 ° C., and cured by heat treatment to form a low refractive index layer (refractive index 1.45, film thickness 95 nm). And an antireflection film No. having a visible light reflectance of 0.5% or less. 1-25 were produced.

<Preparation of medium refractive index layer / high refractive index layer / low refractive index layer>
(Preparation of titanium dioxide dispersion)
Titanium dioxide (primary particle mass average particle size: 50 nm, refractive index: 2.70) 30 parts by mass, anionic diacrylate monomer (PM21, Nippon Kayaku Co., Ltd.) 4.5 parts by mass, cationic methacrylate monomer ( DMAEA (manufactured by Kojin Co., Ltd.) 0.3 parts by mass and 65.2 parts by mass of methyl ethyl ketone were dispersed with a sand grinder to prepare a titanium dioxide dispersion.

(Preparation of coating solution for medium refractive index layer)
In 151.9 g of cyclohexanone and 37.0 g of methyl ethyl ketone, 0.14 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and 0.04 g of a photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) were dissolved. Further, 6.1 g of the above titanium dioxide dispersion and 2.4 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) were added and stirred at room temperature for 30 minutes. The solution was filtered through a polypropylene filter having a pore diameter of 0.4 μm to prepare a coating solution for a medium refractive index layer. When this coating solution was applied to a cellulose ester film and dried and the refractive index after UV curing was measured, a refractive index layer was obtained even with a refractive index of 1.72.

(Preparation of coating solution for high refractive index layer)
In 1152.8 g of cyclohexanone and 37.2 g of methyl ethyl ketone, 0.06 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and 0.02 g of a photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) were dissolved. Furthermore, the ratio of the above titanium dioxide dispersion and the titanium dioxide dispersion of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, Nippon Kayaku Co., Ltd.) is increased, and the refractive index of the high refractive index layer is increased. The amount was adjusted so as to be a ratio, and the mixture was stirred at room temperature for 30 minutes, and then filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a high refractive index layer. When this coating solution was applied to a cellulose ester film, dried and the refractive index after UV curing was measured, a high refractive index layer having a refractive index of 1.9 was obtained.

(Preparation of coating solution for low refractive index layer)
Silane coupling agent (KBM-503, Shin-Etsu Silicone Co., Ltd.) 3 g and 0.1 M / L hydrochloric acid 2 g were added to 200 g of methanol dispersion of silica fine particles with an average particle size of 15 nm (methanol silica sol, manufactured by Nissan Chemical Co., Ltd.). In addition, the mixture was stirred at room temperature for 5 hours and then allowed to stand at room temperature for 3 days to prepare a dispersion of silica fine particles treated with silane coupling. To 35.04 g of the dispersion, 58.35 g of isopropyl alcohol and 39.34 g of diacetone alcohol were added. Further, 1.02 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy) and a solution obtained by dissolving 0.51 g of a photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) in 772.85 g of isopropyl alcohol were added. Furthermore, 25.6 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was added and dissolved. 67.23 g of the resulting solution was added to the above dispersion, a mixture of isopropyl alcohol and diacetone alcohol. The mixture was stirred for 20 minutes at room temperature and filtered through a polypropylene filter having a pore size of 0.4 μm to prepare a coating solution for a low refractive index layer. When this coating solution was applied to a cellulose ester film and dried, and the refractive index after UV curing was measured, the refractive index was 1.45.

  A polarizing plate was prepared using each antireflection film.

[Preparation of polarizing plate]
A polyvinyl alcohol film having a thickness of 120 μm was uniaxially stretched (temperature: 110 ° C., stretch ratio: 5 times). This was immersed in an aqueous solution composed of 0.075 g of iodine, 5 g of potassium iodide and 100 g of water for 60 seconds, and then immersed in an aqueous solution of 68 ° C. composed of 6 g of potassium iodide, 7.5 g of boric acid and 100 g of water. This was washed with water and dried to obtain a polarizing film.

  Subsequently, according to the following processes 1-5, the polarizing film, the said antireflection film, and the cellulose ester film of the back side were bonded together, and the polarizing plate was produced. As the polarizing plate protective film on the back surface side, a cellulose ester film having a retardation (measured at 590 nm, in-plane retardation Ro = 43 nm, retardation in the thickness direction Rt = 135 nm) was used as a polarizing plate.

  Step 1: Soaked in a 2 mol / L sodium hydroxide solution at 60 ° C. for 90 seconds, then washed with water and dried to obtain a saponified cellulose ester film bonded to the polarizer.

  On the other hand, the surface of the anti-reflection layer side of the hard coat film on which the anti-reflection layer was formed was subjected to the saponification treatment while applying a peelable polyethylene film and protecting it from alkali.

  Step 2: The polarizing film was immersed in a polyvinyl alcohol adhesive tank having a solid content of 2% by mass for 1 to 2 seconds.

  Step 3: Gently wipe off the excess adhesive adhering to the polarizing film in Step 2 and place it on the cellulose ester film treated in Step 1, so that the antireflection layer of the hard coat film is on the outside Laminated and placed.

Step 4: Excess adhesive and bubbles were removed from the end of the laminate of the antireflection film, the polarizing film and the cellulose ester film sample laminated in Step 3 with a hand roller, and bonded together. The pressure of the hand roller was 20 to 30 N / cm ² and the roller speed was about 2 m / min.

  Process 5: The sample which bonded the polarizing film produced in the process 4, the cellulose-ester film, and the antireflection film in the 80 degreeC dryer was dried for 2 minutes, and the polarizing plate was produced. Antireflection film No. 1 to 25, polarizing plate No. 1-25 were produced.

[Production of liquid crystal display device]
A liquid crystal panel for viewing angle measurement was produced as follows, and the characteristics as a liquid crystal display device were evaluated.

  The polarizing plates on the both sides of the 15-inch display VL-150SD manufactured by Fujitsu were previously peeled off to remove the polarizing plate No. 1 prepared above. 1-25 were each bonded to the glass surface of a liquid crystal cell.

  At that time, the direction of bonding of the polarizing plate is such that the surface of the optical compensation film (retardation film) is on the liquid crystal cell side, and the absorption axis is in the same direction as the polarizing plate previously bonded. The liquid crystal display device no. 1 to 25 were produced.

[Evaluation]
《Polarizer processing suitability》
The state of the edge when the polarizing plate was cut and the state of generation of chips were evaluated.

○: Hard coat layer peeling at the edge, no edge fluttering, no generation of chips ×: Hard coating layer peeling or chip generation at the edge << Evaluation of visibility >>
Each liquid crystal display device thus obtained was allowed to stand for 100 hours at 60 ° C. and 90% RH, and then returned to 23 ° C. and 55% RH. As a result, when the surface of the display device was observed, the antireflection film laminated on the hard coat film of the present invention was excellent in flatness, whereas the comparative polarizing plate had fine wavy unevenness. It was recognized and my eyes were easy to get tired.

A: No wavy unevenness is observed on the surface. O: A slight wavy unevenness is observed on the surface. Δ: A slight wavy unevenness is slightly observed on the surface. X: A fine wavy unevenness is observed on the surface. 《Evaluation of uneven reflection color》
About each liquid crystal display device, the screen was set as black display and the reflection unevenness of the surface was evaluated visually.

◎: Color unevenness of reflected light is not known, black appears dark ○: Color unevenness of reflected light is slightly recognized △: Color unevenness of reflected light is recognized, but there is no practical problem ×: Reflected light I'm worried about uneven color. Polarizer No. 1-25, liquid crystal display device No.1. The evaluation results for 1 to 25 are shown in Table 4 below.

  When the polarizing plate produced on the liquid crystal display device was cut together with the size of the display panel to bond, the polarizing plate No. 1 of the present invention was cut. 1-13, no. 16, no. 17, no. No. 24 was free from cracking, peeling and chipping of the hard coat layer at the cutting edge, and was excellent in workability without any foreign matter failure. On the other hand, comparative polarizing plate No. 14, no. 15, no. 18-23, no. In No. 25, the edge hard coat layer was peeled off by cutting, resulting in foreign matter failure.

  Separately, the viewing angle was measured in each liquid crystal display device by EZ-contrast manufactured by ELDIM. The viewing angle was expressed in the range of the tilt angle from the normal direction with respect to the panel surface where the contrast ratio between the white display and the black display of the liquid crystal cell is 10 or more.

  As a result, the liquid crystal display device No. 1 using the polarizing plate of the present invention was used. 1-13, no. 16, no. 17, no. 24, it was confirmed that the viewing angle was 160 ° or more when measured from an oblique 45 ° direction. Further, even if there was a fluorescent lamp reflected from an oblique direction, the black color appeared to appear, there was no uneven color of the reflected light, and the eyes did not get tired. In contrast, the liquid crystal display device No. 14, no. 15, no. 18-23, no. In No. 25, black from an oblique direction did not appear due to fine wavy unevenness, the visibility was inferior, and the effect of improving the visibility by widening the viewing angle had declined.

Example 2
[Evaluation of plasma display device]
The prepared antireflection film No. 1 of the present invention. 1-13, no. 16, no. 17, no. 24 is affixed to the forefront of a commercially available panel (PDP-503HD, manufactured by Pioneer Corporation) with an adhesive. 1-16 were produced. The obtained plasma display display device was placed on a desk 75 cm high from the floor, and a Paruk fluorescent lamp (FL40SS / ELW / 37 type, 37 W, Matsushita Electric Industrial Co., Ltd.) was placed on the ceiling 3 m high from the floor. (Manufactured) Eight sets were arranged at intervals of 1.5 m, with two as one set. At this time, when the evaluator is in front of the display device, the fluorescent lamp is arranged so that the fluorescent lamp comes to the ceiling part from the evaluator's overhead to the rear, and the reflection of the fluorescent lamp is ranked as follows. As a result, in the antireflection film using the hard coat layer of the present invention, it was found that there was no distortion until the reflection of a nearby fluorescent lamp, and thus the eyes did not get tired even during long-time viewing.

Example 3
[Production of intermediate layer coated film]
The cellulose ester film No. The intermediate layer coating composition (7) prepared in Example 1 was applied to the surfaces of 1 to 27 using an extrusion coater so that the wet film thickness was 15 μm, and dried at 90 ° C. for 30 seconds. No. 26-52 were obtained.

[Production of hard coat film]
Intermediate layer coat film No. No. 26 to 52, and cellulose ester film No. 9, no. The hard coat layer coating solution prepared in Example 1 was applied to the surface of No. 10 using an extrusion coater, dried at 90 ° C. for 30 seconds, and then irradiated with an ultraviolet lamp having an illuminance of 120 mW / cm ^2. Then, the applied layer was cured with an irradiation amount of 100 mJ / cm ² to form a hard coat layer having a thickness of 6 μm. The coating solution for backcoat layer prepared in Example 1 was coated on the surface opposite to the hard coat layer of these films so as to have a wet film thickness of 15 μm using an extrusion coater. In this way, the hard coat film Nos. 26-54 were produced.

[Evaluation]
Evaluation similar to Example 1 was performed about the obtained optical film. The results are shown in Table 5. It was confirmed that the hard coat film of the present invention has both scratch resistance, pencil hardness, tear resistance, and flatness. The hard coat film of the present invention in which the plasticizer of the cellulose ester film is a phosphate ester plasticizer. 47-49, good physical properties can be obtained, but hard coat film No. 1 of the present invention using a non-phosphate ester plasticizer. It became clear that the better physical properties can be obtained with 26-43.

  On the other hand, Comparative Example Hard Coat Film No. 44-46, no. Nos. 50 to 54 were inferior to the present invention in both scratch resistance and pencil hardness, and the hard coat layer was peeled off at the tear portion in the tear test, and the flatness was also an unfavorable value.

[Preparation of antireflection film]
The hard coat film no. 26 to 54, the same antireflection layer as in Example 1 was formed. 26-54 were produced.

[Preparation of polarizing plate]
Using the antireflection film, as in Example 1, polarizing plate No. 26-54 were produced.

[Production of liquid crystal display device]
As in Example 1, the liquid crystal display device No. 26 to 54 were produced.

  Liquid crystal display device no. The evaluation results for 26-54 are shown in Table 5.

  As a result, the polarizing plate No. 1 of the present invention. 26-43, no. 47-49 reproduced Example 1 and was excellent in workability.

  Further, the liquid crystal display device No. 1 of the present invention. 26-43, no. 47 to 49 were confirmed to have a viewing angle of 160 ° or more when measured from an oblique 45 ° direction. Further, even if there was a fluorescent lamp reflected from an oblique direction, the black color appeared to appear, there was no uneven color of the reflected light, and the eyes did not get tired. However, the liquid crystal display device no. Nos. 47 to 49 show slight wavy irregularities on the surface, and the liquid crystal display device No. The result was slightly inferior to 26-43. In contrast, the liquid crystal display device No. 44-46, NO. In 50 to 52, black from an oblique direction did not appear due to fine wavy unevenness, the visibility was inferior, and the effect of improving the visibility by widening the viewing angle had declined. Furthermore, the liquid crystal display device NO. 53, no. No. 54 was inferior in polarizing plate processing suitability.

Example 4
A conductive polymer resin P-1 (0.1 to 0.3 μm particles) having the following structure was added to the intermediate layer coating compositions 6 to 13 of Example 1 so that the total solid content was 60% by volume. In the same manner as for the intermediate layer coat film and the hard coat film No. 55-62, antireflection film No. 55-62, polarizing plate No. 55-62, liquid crystal display device no. 55 to 62 were prepared and evaluated in the same manner as in Example 1. However, scratch resistance, pencil hardness, tear resistance, flatness, polarizing plate processing suitability, reflection color unevenness, and visibility were good results, and surface resistivity of under 23 ° C. RH 55% are both a ^{2 × 10 10 Ω~5 × 10 10} Ω, had good antistatic performance.

Further, 2 parts by mass of fine powder silica particles (Aerosil 200, manufactured by Nippon Aerosil Co., Ltd.) and 100 parts by mass of methanol were stirred for 1 hour, and then dispersed with a pressure homogenizer at a pressure of 2.94 × 10 ⁷ Pa. A silica dispersion with a particle size of 245 nm was obtained.

  The silica dispersion was added to the intermediate layer coating compositions 6 to 13 so that the finely divided silica particles were 55% by volume of the total solid content, and the intermediate layer coat film and the hard coat film No. 63-70, antireflection film No. 63-70, polarizing plate No. 63-70, liquid crystal display device no. 63-70 were produced. Similarly, a polymethyl methacrylate crosslinked particle dispersion (MS-300K, manufactured by Soken Chemical Co., Ltd.) is added to the intermediate layer coating compositions 6 to 13 so that the polymethyl methacrylate crosslinked particles become 70% by volume of the total solid content. Intermediate layer coat film and hard coat film No. 71-78, antireflective film No. 71-78, Polarizing Plate No. 71-78, liquid crystal display device no. 71-78 were produced.

  These were also evaluated for scratch resistance, pencil hardness, tear test, flatness, suitability for polarizing plate processing, reflection color unevenness, and visibility, but all were good and no interference unevenness was observed. Furthermore, the friction coefficient of the intermediate layer coated film was 0.6 when fine particle silica was used, and 0.3 when polymethyl methacrylate crosslinked particles were used, and no blocking was observed.

  The above evaluation results are shown in Table 6 below.

It is a figure which shows an example of the plasma discharge processing apparatus used in forming the metal oxide layer of this invention. It is a figure which shows an example of the plasma discharge processing apparatus which has a rotating electrode useful for forming the metal oxide thin film layer of this invention, and a fixed electrode.

Explanation of symbols

F hard coat film G reactive gas G ′ exhaust gas 10A, 10B, 110 rotating electrode 11A, 11B, 11C, 11D U-turn roll 20, 21 guide roll 30 reactive gas supply unit 40, 140 gas exhaust port 50, 150 discharge unit 51 rectification Plate 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 plate 130 Air supply pipe 131 Reactive gas generator 190 Plasma discharge treatment vessel

Claims (16)

In the method for producing an optical film in which a hard coat layer is provided on a cellulose ester film substrate, the cellulose ester film substrate contains an ultraviolet absorber and two or more plasticizers, and has a total acyl group substitution degree of 2.6. After casting a solution containing a cellulose ester having a value of ˜2.9, number average molecular weight (Mn) 80000-200000, weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.4 to 3.0, A method of producing an optical film by coating at least one intermediate layer on the cellulose ester film base material, and then coating a hard coat layer. The coating composition for providing the intermediate layer contains at least one solvent that can swell or dissolve the substrate, and the coating composition of the solvent that can swell or dissolve the substrate The proportion of the total agent is 20 to 95% by volume, and the coating composition for providing the intermediate layer is applied so that the wet film thickness per layer of the intermediate layer is 5 to 60 μm. A method for producing an optical film. The method for producing an optical film according to claim 1, wherein the intermediate layer has at least one binder, and the binder contains an acrylic resin or a cellulose ester. Two or more kinds of plasticizers contained in the cellulose ester film substrate are selected from plasticizers other than phosphate ester plasticizers, and the content of phosphate ester plasticizers is less than 1% by mass. The method for producing an optical film according to claim 1, wherein the optical film is a film. The method for producing an optical film according to claim 1, wherein at least one of the plasticizers is a polyhydric alcohol ester plasticizer. An optical film produced by the method according to claim 1. An optical film having at least one intermediate layer and a hard coat layer on a cellulose ester film substrate, wherein the cellulose ester film substrate contains an ultraviolet absorber and two or more plasticizers, and is substituted with a total acyl group A solution containing a cellulose ester having a degree of 2.6 to 2.9, a number average molecular weight (Mn) of 80000 to 200000, and a weight average molecular weight (Mw) / number average molecular weight (Mn) of 1.4 to 3.0. The intermediate layer coating composition is produced by biaxial stretching after casting, and the intermediate layer contains a solvent capable of swelling or dissolving the cellulose ester film substrate in an amount of 20 to 95% by volume based on the total solvent. An optical film characterized by having a hard coat layer on an intermediate layer formed by coating so as to have a wet film thickness of 5 to 60 μm. The optical film according to claim 6, wherein the intermediate layer has at least one binder. The optical film according to claim 7, wherein the binder contains an acrylic resin or a cellulose ester. The optical film according to claim 8, wherein the cellulose ester used for the binder is a cellulose ester having a total acyl group substitution degree of 0.1 or more smaller than the total acyl group substitution degree of the cellulose ester film base material. The intermediate layer contains at least one binder and fine particles having an average particle diameter of 0.01 to 3 μm, and the content of the fine particles is 5 to 90% by volume of the total solid content of the intermediate layer. The optical film according to any one of claims 6 to 9. Two or more kinds of plasticizers contained in the cellulose ester film substrate are selected from plasticizers other than phosphate ester plasticizers, and the content of phosphate ester plasticizers is less than 1% by mass. The optical film according to claim 6, wherein the optical film is a film. The optical film according to any one of claims 6 to 11, wherein at least one of the plasticizers is a polyhydric alcohol ester plasticizer. The optical film according to claim 6, wherein an antireflection layer is provided on the hard coat layer. 14. The optical film according to claim 6, wherein a width of the cellulose ester film substrate is in a range of 1.4 m to 4 m. A polarizing plate comprising the optical film according to any one of claims 6 to 14 provided on at least one surface. A display device comprising the polarizing plate according to claim 15.

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