JP2008242003A - Method for manufacturing hard coat film, optical film and anti-reflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a hard coat film, with which a high quality coating film, can be obtained without being accompanied by defective adhesion, occurrence of pinhole-shaped uncoated spots and so on, in the method for manufacturing the hard coat film of a coating layer obtained by applying a coating liquid containing an active energy ray-curable resin and a solvent to a substrate, and making the coating layer irradiated with the active energy ray after drying, and to provide an optical film and an anti-reflection film obtained by the method for manufacturing the hard coat film. <P>SOLUTION: In the method for manufacturing the hard coat film which is composed of the coating layer obtained by applying a coating liquid containing an active energy ray-curable resin and a solvent to a substrate, and making the coating layer irradiated with the active energy ray after drying, wherein the coating liquid is applied to the substrate by using an application head and dried so as to obtain the coating layer, a residual solvent content of the coating film before the active energy ray irradiation process is required to be 3-15 mass%. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing an optical film, an antireflection film, and a hard coat film obtained by applying and drying a coating liquid containing an active energy ray-curable resin and a solvent on a support and curing the active energy ray.

  In transparent resin films used for optical applications such as a polarizing plate protective film for liquid crystal displays and a circular polarizing plate protective film used in organic EL displays, several functional thin films are applied to give various functions. It is installed. Examples of the functional thin film include an antistatic layer for providing an antistatic function, a hard coat layer for improving surface hardness, an undercoat layer for improving film adhesion, and an anti-layer for preventing curling. A curl layer, an antiglare layer, an antireflection layer, or the like. Of these, the hard coat layer and the antireflection layer are particularly important.

  When forming a hard-coat layer in the said transparent resin film, the hardened | cured material layer normally hardened | cured with active energy rays, such as an active energy ray, is applied, and an active energy ray is irradiated and hardened. At this time, there is a problem that the hardness of the hard coat layer cannot be sufficiently obtained, and this improvement has been demanded. Furthermore, when providing a multilayer antireflection layer on the hard coat film on which the hard coat layer is formed, the accuracy of the film thickness of each antireflection layer, the improvement of the adhesion between the hard coat layer and each antireflection layer, Strength is required.

As a method for producing a hard coat film using an active energy ray-curable resin, after applying a curable coating on a resin film substrate, the active energy ray is irradiated while being heated from the back surface by being wound around a heating roll. And a method of forming a coating film by curing (for example, see Patent Document 1).
Japanese Patent Laid-Open No. 3-4969

  However, when an antireflection film in which a hard coat layer or a multilayer antireflection film is formed on a plastic film by the technique described in Patent Document 1, the adhesion of each layer is poor, and the occurrence of uneven color due to poor adhesion, There was a problem of occurrence of pinhole-shaped uncoated portions.

  The present invention has been made in view of the above problems, and its purpose is to produce a hard coat film using an active energy ray curable resin, which does not cause poor adhesion or the occurrence of pinhole-shaped uncoated areas. It is providing the optical film and antireflection film by the manufacturing method of the hard coat film which can obtain a various coating film, and the manufacturing method of this hard coat film.

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

1.
On the support, a coating liquid containing an active energy ray-curable resin and a solvent is coated to form a coating film; and
A drying step of drying the coating film on the support after the coating step;
In the method for producing a hard coat film having an active energy ray irradiation step of irradiating an active energy ray to the coating film on the support after the drying step,
A method for producing a hard coat film, wherein the residual solvent content of the coating film is 3 to 15% by mass after the drying step and before the active energy ray irradiation step.

2.
2. The method for producing a hard coat film according to 1, wherein the temperature of the coating film after the drying step and before the active energy ray irradiation step is 15 to 80 ° C.

3.
3. The hard coat film according to 1 or 2, wherein an active energy ray irradiation intensity in the active energy ray irradiation step is 50 to 350 mJ / cm ² in terms of an integrated light amount (an ultraviolet integrated energy amount in a wavelength range of 300 to 390 nm). Manufacturing method.

4).
In the said active energy ray irradiation process, the illumination intensity of an active energy ray is 200-600 mW / cm < ² >, The manufacturing method of the hard coat film in any one of 1-3 characterized by the above-mentioned.

5.
5. An optical film comprising at least one coating film obtained by the method for producing a hard coat film according to any one of 1 to 4.

6).
5. An antireflection film comprising at least one coating film obtained by the method for producing a hard coat film according to any one of 1 to 4.

  According to the present invention, in a method for producing a hard coat film in which a coating liquid containing an active energy ray-curable resin and a solvent is applied onto a support to form a coating film, the active energy is obtained after the drying step. When the content of the residual solvent in the coating film before the irradiation process is 3 to 15% by mass, it is possible to obtain a high-quality coating film that does not cause adhesion failure or occurrence of pinhole-shaped uncoated areas. A high quality optical film and antireflection film can be provided.

  An embodiment of the present invention will be described with reference to FIG. 1, but the present invention is not limited to these.

  FIG. 1 is a schematic diagram of a production apparatus for explaining a method for producing a hard coat film for forming a coating film on a support.

  In the figure, 1 indicates a production apparatus. The manufacturing method of the hard coat film using the production apparatus 1 includes an application object supply process 2, an application process 3, a drying process 4, a cooling process 5, an active energy ray irradiation process 7, and a recovery process 6. have. The supply process 2 has a feeding device (not shown) that feeds out a roll-like object 202 in which a substance 201 that is a belt-like support is wound around a winding core.

  The coating process 3 includes a backup roll 301 that holds the coating object 201 continuously conveyed from the supply process 2, and a coating head that applies the coating liquid to the coating object 201 that is continuously conveyed and held by the backup roll 301. 302 and a decompression chamber 303 provided on the upstream side of the coating head 302 in order to stabilize a bead (a pool of coating solution) formed between the coating liquid from the coating head 302 and the coating object 201 during coating. And a coating device 304 having

  The coating liquid discharged from the coating head 302 includes an active energy ray-curable resin and a solvent, and the flow rate thereof can be adjusted by a pump (not shown). The flow rate of the coating liquid discharged from the coating head 302 is determined to be an amount capable of stably forming a coating layer having a predetermined thickness when continuously coated under the conditions of the coating head 302 adjusted in advance.

  The decompression chamber 303 can adjust the degree of decompression. The decompression chamber 303 is connected to a decompression blower (not shown), and the inside is decompressed. The decompression chamber 303 is in a state where there is no air leakage, and the gap between the decompression chamber 303 and the backup roll is adjusted to be narrow so as to form a stable coating liquid bead.

  The drying process 4 includes a drying device 401 that dries the wet coating film applied on the coating object 201 in the coating process 3. Reference numeral 402 denotes a drying gas inlet, and reference numeral 403 denotes a discharge port. The temperature and air volume of the drying air can be appropriately determined according to the type of coating film and the type of the object 201 to be coated. In this drying step 4, the residual solvent content of the coating film after drying can be adjusted by setting conditions such as the temperature and amount of drying air and the drying time. The content of the residual solvent in the coating film after drying can be measured by comparing the unit mass of the coating film after drying with the mass after sufficiently drying the coating film.

  In the cooling step 5, the temperature of the object 201 having the coating film dried in the drying step 4 can be cooled and adjusted to an appropriate temperature. A cooling device 501 for lowering the temperature is provided, 502 indicates an inlet for cooling air, and 503 indicates an outlet for cooling air. The temperature and air volume of the cooling air can be appropriately determined depending on the type of coating film and the type of the object 201 to be coated. In addition, if the cooling temperature is appropriate without providing the cooling step 5, the cooling device need not be installed.

  The coating film applied to the coating object 201 with a constant film thickness is adjusted so that the residual solvent content is 3 to 15% by mass through the drying step 4.

  After adjustment in this way, the coating film is cured by irradiating the coating film with an activation energy beam in the activation energy beam irradiation step 7 using the activation energy beam irradiation apparatus 701. When the content of the residual solvent before the active energy ray irradiation step 7 is less than 3% by mass, even if a radical of the polymerization initiator is generated, the reaction progress rate is slow, and a film having sufficient hardness cannot be obtained. Scratches are likely to occur. As a result, due to dust generation of the coating film itself, a failure of the pinhole-shaped uncoated portion occurs when the film is laminated thereon. Further, in the recovery process 6 in the subsequent process, fusion between the films occurs, and the yield of the product is deteriorated.

  Further, if the content of the residual solvent before the active energy ray irradiation step 7 exceeds 15% by mass, the base material is deformed, for example, by slight protrusions or dents, and when it is laminated thereon, color unevenness, horizontal steps, etc. Will occur.

  Moreover, 15-80 degreeC is preferable and, as for the temperature of the coating film immediately before the active energy ray irradiation process 7, More preferably, it is 20-35 degreeC. If the temperature is less than 15 ° C., the temperature of the coating film is low, the active energy ray curing is not sufficiently performed, and the hardness may be insufficient. When the temperature exceeds 80 ° C., the fluidity of the coating film becomes too high, and partial curing unevenness occurs at the time of active energy ray curing, which may easily cause film thickness unevenness. The temperature of the coating film can be measured by a generally known non-contact thermometer such as a laser method or an infrared method, and shows an average value measured at five points in the width direction.

Moreover, the active energy ray irradiation intensity in the active energy ray irradiation step 7 is preferably 50 to 350 mJ / cm ^{2 as the} integrated light amount (ultraviolet integrated energy amount in the wavelength region of 300 to 390 nm). When the integrated light quantity is less than 50 mJ / cm ² , it may be difficult to obtain sufficient hardness due to insufficient light quantity. On the other hand, if it exceeds 350 mJ / cm ² , the coating film may be thinly discolored.

Moreover, 200-600 mW / cm < ² > is preferable for the illumination intensity at the time of irradiation. By setting the illuminance within this range, the productivity is good, the film is cured at an appropriate speed, and a high-quality cured film is obtained.

  As a method for adjusting the illuminance and the inclination in such a range, the type of active energy ray irradiation lamp, the type / structure of the reflection plate (condensing type or diffusion type) described later, the installation of the diffusion plate, the transparent resin film It can be adjusted by appropriately changing the conveyance speed, the distance between the lamp and the transparent resin film, and the like.

  When the active energy ray is ultraviolet light, the above illuminance measurement can be performed with Eye Graphics Co., Ltd. UV METER UVPF-36, Iida Trading Co., Ltd. ultraviolet intensity meter RMX-3W, VLX-3W, or the like.

  When the active energy ray is ultraviolet light, any light source that generates ultraviolet light can be used. For example, low pressure mercury lamp, medium pressure mercury lamp, high pressure mercury lamp, ultra high pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, etc. Can be used.

  The collection step 6 includes a winding device (not shown) that winds up the coating object 201 (coating object) on which a coating film is formed. Reference numeral 601 denotes a roll-like coated material that is wound around and collected by a winding core. Reference numerals a to d denote transport rolls for transporting an object 201 having a coating film.

  Hereinafter, the material used for this invention is demonstrated in detail.

  The resin film used in the present invention is not particularly limited. For example, polyester film, polyethylene film, polypropylene film, cellophane, cellulose diacetate film, cellulose acetate butyrate film, cellulose acetate propionate film, cellulose as transparent resin film Film made of triacetate or cellulose derivative, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, polycarbonate film, cycloolefin polymer film, norbornene resin film, polymethylpentene film, polyether ketone Film, polyethersulfone film, polysulfone film Lum, polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, polymethyl methacrylate film, may be mentioned acrylic film or polyarylate film.

  In the present invention, it has excellent curing particularly for a wide resin film, and is particularly preferably applied to a resin film having a width of 1.4 to 4 m. Moreover, the effect excellent especially with respect to the film in which a resin film contains a cellulose ester can be expected. This is because the cellulose ester film has additives such as a plasticizer and is susceptible to dissolution and swelling by the coating solvent. Examples of the cellulose ester film include a cellulose acetate film, a cellulose acetate butyrate film, a cellulose acetate propionate film, and a cellulose triacetate film (TAC). In particular, the influence is remarkable in a thin film having a film thickness of 10 to 60 μm, and the method of the present invention can exhibit an excellent effect as a method for producing an optical film that requires high flatness.

  The film used in the present invention may be a film manufactured by melt casting or a film manufactured by solution casting.

  Hereinafter, a method for forming a cellulose ester film will be described. Cellulose ester film is generally made by dissolving cellulose ester flake raw material and plasticizer in methylene chloride to form a viscous liquid, and then dissolving the plasticizer into dope. From the extruder die, stainless steel rotating endlessly, etc. It is cast on a metal belt (also referred to as a band), dried, peeled off from the belt in a dry state, dried from both sides by a transport device such as a roll, and wound up. The cellulose ester film used in the production of the optical film of the present invention is a film that is held or stretched by holding the end of the film by a device such as a tenter in the drying process and applying tension in the width direction. It is preferable because higher planarity can be obtained.

  The cellulose ester resin of the cellulose ester film used for the production of the optical film of the present invention is preferably a cellulose lower fatty acid ester resin. The lower fatty acid in the lower fatty acid ester of cellulose is preferably a fatty acid having 6 or less carbon atoms. For example, cellulose acetate, cellulose propionate, cellulose butyrate and the like are particularly preferred examples of the lower fatty acid ester of cellulose.

  In addition to the above, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate propionate buty described in JP-A Nos. 10-45804, 8-231761, U.S. Pat. No. 2,319,052 and the like. Mixed fatty acid esters such as rate can be used. Among the above description, cellulose triacetate (hereinafter referred to as TAC) and cellulose acetate propionate are the most preferably used lower fatty acid esters of cellulose.

  The number average molecular weight of the cellulose ester according to the present invention is preferably 70,000 to 250,000, which has a high mechanical strength when molded and has an appropriate dope viscosity, and more preferably 80,000 to 150,000. is there.

  The average molecular weight and molecular weight distribution of the cellulose ester can be measured by a known method using gel permeation chromatography. Using this, the number average molecular weight and the weight average molecular weight are measured.

  The measurement conditions are as follows.

<Gel permeation chromatography: molecular weight measurement by GPC>
The method for measuring the number average molecular weight by GPC was diluted with tetrahydrofuran so that the sample solid content concentration was 0.1%. Since the particles were included, the particles were removed using a filter, and the measurement was performed at a column temperature of 25 ° C. under the following conditions.

Column: Tosoh Corporation TSKgelG5000HXL-TSKgelG2000H XL
Eluent: THF (tetrahydrofuran)
Pump: L6000 (manufactured by Hitachi, Ltd.)
Flow rate: 1.0 ml / min
Detection: RI Model 504 (manufactured by GL Sciences)
Sample concentration: 0.8%
Standard sample / calibration curve: Standard polystyrene STK standard polystyrene (manufactured by Tosoh Corp.) Mw = 100000-500 calibration curves with 13 samples are used. It is preferable that the 13 samples are substantially equally spaced.

  The cellulose ester used in the present invention has an acetyl group and / or a propionyl group as a substituent, and when the substitution degree of the acetyl group is X and the substitution degree of the propionyl group is Y, the following formula (I) and Cellulose esters that simultaneously satisfy (II) are particularly preferred.

(I) 2.5 ≦ X + Y ≦ 3.0
(II) 0 ≦ Y ≦ 1.2
The measuring method of the substitution degree of an acyl group can be measured according to the provisions of ASTM-D817-96.

  As the cellulose ester, either a cellulose ester synthesized from cotton linter and a cellulose ester synthesized from wood pulp can be used alone or mixed at an arbitrary ratio. If peelability from the belt or drum becomes a problem, it is preferable to use a large amount of cellulose ester synthesized from a cotton linter that has good peelability from the belt or drum. When a mixture of cellulose esters synthesized from wood pulp is used, the ratio of cellulose esters synthesized from cotton linters is 40% by mass or more, and the effect of releasability becomes remarkable, and more preferably 60% by mass or more. Preferably it is used alone.

  The solvent used in preparing the dope may be any solvent that can dissolve the cellulose ester, and it can be dissolved by mixing with other solvents even if it cannot be dissolved alone. Can be used. In general, a mixed solvent comprising a poor solvent of methylene chloride and cellulose ester, which is a good solvent, is used, and the mixed solvent preferably contains 4 to 30% by mass of the poor solvent.

  Other good solvents that can be used include, for example, methyl acetate, ethyl acetate, amyl acetate, acetone, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, cyclohexanone, ethyl formate, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol, 1,3-difluoro-2-propanol, 1,1,1,3,3,3-hexafluoro-2-methyl-2-propanol, 1, 1,1,3,3,3-hexafluoro-2-propanol, 2,2,3,3,3-pentafluoro-1-propanol, nitroethane and the like, and organic halogen compounds such as methylene chloride , Dioxolane derivatives, methyl acetate, ethyl acetate, acetone and the like are preferable organic solvents (ie, good solvents). .

  Examples of the poor solvent for cellulose ester include alcohols having 1 to 8 carbon atoms such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, sec-butanol, and tert-butanol. These poor solvents can be used alone or in combination of two or more.

  Examples of the plasticizer that can be used in the present invention include phosphate ester plasticizers, polyhydric alcohol ester plasticizers, phthalate ester plasticizers, trimellitic ester plasticizers, and pyromellitic acid plasticizers. Glycolate plasticizers, citrate ester plasticizers, polyester plasticizers, fatty acid ester plasticizers, polycarboxylic acid ester plasticizers, and the like can be preferably used.

  Among these, polyhydric alcohol ester plasticizers, phthalate ester plasticizers, citrate ester plasticizers, fatty acid ester plasticizers, glycolate plasticizers, polycarboxylic acid ester plasticizers, and the like are preferable. In particular, it is preferable to use 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 preferably used in the present invention is represented by the following general formula (a).

Formula (a) 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 polyhydric alcohol ester, 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 1 to 3 alkoxy groups such as an alkyl group, a methoxy group or an ethoxy group are introduced into the benzene ring of benzoic acid such as benzoic acid or toluic acid, biphenylcarboxylic acid, Examples thereof include aromatic monocarboxylic acids having two or more benzene rings such as naphthalenecarboxylic acid and tetralincarboxylic acid, or derivatives thereof. 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.

  Polycarboxylic acid ester plasticizers can also be preferably used. Specifically, it is preferable to add the polyvalent carboxylic acid ester described in paragraphs [0015] to [0020] of JP-A No. 2002-265639 as one of the plasticizers.

  In addition, phosphate plasticizers can be used as other plasticizers, such as triphenyl phosphate, tricresyl phosphate, cresyl diphenyl phosphate, octyl diphenyl phosphate, diphenyl biphenyl phosphate, trioctyl phosphate, tributyl phosphate, etc. It is done.

  In addition, it is also preferable to contain an acrylic polymer described in JP-A-2003-12859.

  These plasticizers can be used alone or in combination of two or more.

  In consideration of dimensional stability and processability, the amount of the plasticizer used can be added in an amount of 1 to 40% by weight, preferably 3 to 20% by weight, based on the cellulose ester. Preferably it is 4-15 mass%. If the amount is less than 3% by mass, a smooth cut surface cannot be obtained when slitting or punching, resulting in increased generation of chips.

  It is preferable to add an antioxidant or an ultraviolet absorber to the cellulose ester film of the present invention.

  As the antioxidant, a hindered phenol compound is preferably used, and 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl). -4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3 5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5 -Triazine, 2,2-thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3 -Di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexamethylenebis (3,5-di-t-butyl-4-hydroxyhydrocinnamamide), 1,3,5-trimethyl- 2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate . In particular, 2,6-di-t-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate] is preferred. Further, for example, hydrazine-based metal deactivators such as N, N′-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine and tris (2,4-di-t A phosphorus-based processing stabilizer such as -butylphenyl) phosphite may be used in combination. The amount of these compounds added is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm in terms of mass ratio with respect to the cellulose ester.

  In addition, thermal stabilizers such as kaolin, talc, diatomaceous earth, quartz, calcium carbonate, barium sulfate, titanium oxide, alumina and other inorganic fine particles, and alkaline earth metal salts such as calcium and magnesium may be added. .

  The cellulose ester film of the present invention is used for a polarizing plate or a liquid crystal display member because of its high dimensional stability, but an ultraviolet absorber is preferably used from the viewpoint of preventing deterioration of the polarizing plate or the liquid crystal.

  As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Specifically, the transmittance at 380 nm is preferably less than 10%, more preferably less than 5%.

  Specific examples of the ultraviolet absorber preferably used in the present invention include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. Moreover, the polymeric ultraviolet absorbers described in JP-A-6-148430 and JP-A-2002-47357 are also preferably used. Or the ultraviolet absorber described in Unexamined-Japanese-Patent No. 10-152568 can also be used.

  As the benzotriazole ultraviolet absorber, a compound represented by the following general formula [1] is preferably 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, it 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 (TINUVIN171, manufactured by Ciba Specialty Chemicals)
UV-9: Octyl-3- [3-tert-butyl-4-hydroxy-5- (chloro-2H-benzotriazol-2-yl) phenyl] propionate and 2-ethylhexyl-3- [3-tert-butyl- Mixture of 4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate (TINUVIN109, manufactured by Ciba Specialty Chemicals)
Although the specific example of a benzophenone series ultraviolet absorber is shown below, this invention is not limited to these.

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)
In the cellulose ester film used for this invention, it is preferable to add microparticles | fine-particles in order to provide slipperiness to a film and to prevent blocking of a roll-shaped film.

  The fine particles according to the present invention include inorganic compound fine particles or organic compound fine particles.

  Inorganic compounds include silicon-containing compounds, silicon dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate, etc. More preferred are silicon-containing inorganic compounds and zirconium oxide, but silicon dioxide is particularly preferably used because the turbidity of the cellulose ester laminated film can be reduced.

  As the silicon dioxide fine particles, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used.

  As the fine particles of zirconium oxide, commercially available products such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.

  As the organic compound, for example, polymers such as silicone resin, fluorine resin and acrylic resin are preferable, and among them, silicone resin is preferably used.

  Among the above-described silicone resins, those having a three-dimensional network structure are particularly preferable. For example, Tospearl 103, 105, 108, 120, 145, 3120 and 240 (above Toshiba Silicone Co., Ltd.) ) Etc. can be used.

  The primary average particle diameter of the fine particles is preferably 20 nm or less, more preferably 5 to 16 nm, and particularly preferably 5 to 12 nm, from the viewpoint of keeping the haze low. For example, they are commercially available under the trade names of Aerosil 200V and Aerosil R972V (manufactured by Nippon Aerosil Co., Ltd.) and can be preferably used.

<< Preparation Method A >>
After stirring and mixing the solvent and the fine particles, dispersion is performed with a disperser. This is a fine particle dispersion. The fine particle dispersion is added to the dope solution and stirred.

<< Preparation Method B >>
After stirring and mixing the solvent and the fine particles, dispersion is performed with a disperser. This is a fine particle dispersion. Separately, a small amount of cellulose ester is added to the solvent and dissolved by stirring. As the cellulose ester added here, it is particularly preferable to add the solid material of the present invention.

  The fine particle dispersion is added to this and stirred. This is a fine particle addition solution. The fine particle additive solution is sufficiently mixed with the dope solution using an in-line mixer.

<< Preparation Method C >>
Add a small amount of cellulose ester to the solvent and dissolve with stirring. Fine particles are added to this and dispersed by a disperser. This is a fine particle addition solution. The fine particle additive solution is sufficiently mixed with the dope solution using an in-line mixer.

  Preparation method A is excellent in dispersibility of silicon dioxide fine particles, and preparation method C is excellent in that silicon dioxide fine particles are difficult to re-aggregate. Among them, the preparation method B described above is a preferable preparation method that is excellent in both dispersibility of the silicon dioxide fine particles and that the silicon dioxide fine particles are less likely to reaggregate.

《Distribution method》
The concentration of silicon dioxide when the silicon dioxide fine particles are mixed with a solvent and dispersed is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and most preferably 15 to 20% by mass. A higher dispersion concentration is preferable because liquid turbidity with respect to the added amount tends to be low, and haze and aggregates are improved.

  The solvent used is preferably lower alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol and the like. Although it does not specifically limit as solvents other than a lower alcohol, It is preferable to use the solvent used at the time of film forming of a cellulose ester.

  The amount of silicon dioxide fine particles added to cellulose ester is preferably 0.01 to 0.3 parts by mass, more preferably 0.05 to 0.2 parts by mass, and more preferably 0.0 to 0.2 parts by mass with respect to 100 parts by mass of cellulose ester. Most preferred is 08 to 0.12 parts by mass. The larger the added amount, the better the dynamic friction coefficient, and the smaller the added amount, the lower the haze and the fewer agglomerates.

  As the disperser, a normal disperser can be used. Dispersers can be broadly divided into media dispersers and medialess dispersers. For dispersing silicon dioxide fine particles, a medialess disperser is preferred because of its low haze.

  Examples of the media disperser include a ball mill, a sand mill, and a dyno mill.

  Examples of the medialess disperser include an ultrasonic type, a centrifugal type, and a high pressure type. In the present invention, a high pressure disperser is preferable. The high pressure dispersion device is a device that creates special conditions such as high shear and high pressure by passing a composition in which fine particles and a solvent are mixed at high speed through a narrow tube. When processing with a high-pressure dispersion apparatus, for example, the maximum pressure condition inside the apparatus is preferably 9.807 MPa or more in a thin tube having a tube diameter of 1 to 2000 μm. More preferably, it is 19.613 MPa or more. Further, at that time, it is preferable that the maximum reaching speed reaches 100 m / second or more, and the heat transfer speed reaches 420 kJ / hour or more.

  The high-pressure dispersing apparatus as described above includes an ultra-high pressure homogenizer (trade name: Microfluidizer) manufactured by Microfluidics Corporation or a nanomizer manufactured by Nanomizer. Examples include UHN-01 manufactured by Wako Machine Co., Ltd.

  Further, these fine particles may be uniformly distributed in the thickness direction of the film, but more preferably distributed so as to be mainly present in the vicinity of the surface, for example, by co-casting method, It is preferable to add fine particles mainly to the dope arranged on the surface layer side using two or more kinds of dopes because a film having high slipperiness and low haze can be obtained. Preferably, it is desirable to add fine particles mainly to at least one dope on the surface layer side or two dopes on the surface layer side using three kinds of dopes, and the dope forming the central layer contains almost no fine particles. , Preferably not included at all. Additives that may cause bleed-out, such as plasticizers or UV absorbers, are mainly added to the dope forming the center layer, and the two dopes on the surface layer side are added to the dope forming the center layer. The addition amount is preferably less than 80% by mass, more preferably less than 50% by mass, and it is more preferable to add little or no addition in terms of preventing process contamination.

  After the cellulose ester film obtained in such a film forming process is wound up once or continuously without being wound up, the coating layer can be provided by the method for producing a hard coat film of the present invention.

  The active energy ray-curable resin layer according to the present invention will be described. The active energy ray-curable resin layer refers to a layer mainly composed of a resin that is cured through a crosslinking reaction or the like by irradiation with active energy rays such as ultraviolet rays or electron beams. Typical examples of the active energy ray curable resin include an ultraviolet curable resin and an electron beam curable resin, but a resin that is cured by irradiation with an active energy ray other than an ultraviolet ray or an electron beam may be used. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic urethane resin, an ultraviolet curable polyester acrylate resin, an ultraviolet curable epoxy acrylate resin, an ultraviolet curable polyol acrylate resin, and an ultraviolet curable epoxy resin. I can do it.

  UV curable acrylic urethane resins generally include 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate (hereinafter referred to as acrylates) in addition to 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, JP-A-59-151110).

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

  Specific examples of the ultraviolet curable epoxy acrylate resin include those obtained by reacting epoxy acrylate with an oligomer, a reactive diluent and a photoinitiator added thereto (for example, JP-A-1- No. 105738). As this photoreaction initiator, one or more kinds selected from benzoin derivatives, oxime ketone derivatives, benzophenone derivatives, thioxanthone derivatives and the like can be selected and used.

  Specific examples of ultraviolet curable polyol acrylate resins include trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, alkyl-modified dipentaerythritol pentaacrylate. Etc. can be mentioned. These resins are usually used together with known photosensitizers. Moreover, the said photoinitiator can also be used as a photosensitizer. Specific examples include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, tetramethyluram monosulfide, thioxanthone, and derivatives thereof. Further, when using an epoxy acrylate photoreactant, 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 mass, preferably 1 to 10 parts by mass with respect to 100 parts by mass of the composition.

Examples of the active energy rays include electron beams, X-rays, radiation, visible light, and ultraviolet rays. In particular, ultraviolet rays are preferably used. In this case, any light source that generates ultraviolet rays can be used. For example, the low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultrahigh-pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, etc. can be used. Irradiation conditions vary depending on each lamp, but preferably 50 to 350 mJ / cm ² in terms of integrated light quantity (ultraviolet integrated energy amount in a wavelength range of 300 to 390 nm) as described above.

  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.

  In order to provide the active energy ray-cured resin layer with an antiglare property on the surface of the display device panel, to prevent adhesion with other substances, or to provide scratch resistance, inorganic or organic fine particles Can also be added. For example, examples of inorganic particles include silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, tin oxide, zinc oxide, calcium carbonate, barium sulfate, talc, kaolin, and calcium sulfate. Methyl methacrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin resin powder, polyester It can be added to an ultraviolet curable resin composition such as a resin resin powder, a polyamide resin powder, a polyimide resin powder, or a polyfluorinated ethylene resin powder. The average particle diameter of these particle powders is 0.01 μm to 10 μm, and the ratio of the ultraviolet curable resin composition to the fine particle powder is 0.1 to 20 parts by mass with respect to 100 parts by mass of the resin composition. It is desirable to blend so that. In order to impart an antiglare effect, 1 to 15 parts by mass is preferable with respect to an average particle size of 0.1 to 3 μm and 100 parts by mass of the resin composition.

  Furthermore, the particles having a volume average particle size of 0.005 to 0.1 μm are added to 100 parts by mass of the resin composition with the same components as those described above in order to perform the blocking prevention function or to form fine irregularities. 0.1-5 mass parts can also be used together.

  The organic solvent contained in the coating solution is evaporated before the ultraviolet irradiation, and is dried in the drying step so that the residual solvent content is 3 to 15% by mass.

  Examples of organic solvents that can be used as the coating solution include alcohols such as methanol, ethanol, propanol, n-butanol, 2-butanol, tert-butanol, and cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, and acetone, ethyl acetate, Esters such as methyl acetate, ethyl lactate, isopropyl acetate, amyl acetate, and ethyl butyrate, glycol ethers (propylene glycol mono (C1-C4) alkyl ethers (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 ester (propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate)), toluene, benzene, cyclohexane, and other solvents hydrocarbons such as n- hexane. Although not particularly limited to these, a solvent in which these are appropriately mixed is preferably used.

  As a method for producing a hard coat film of a coating solution containing an active energy ray curable resin, a known method such as a gravure coater, spinner coater, wire bar coater, roll coater, reverse coater, extrusion coater, air doctor coater, or the like may be used. I can do it. The coating amount is suitably 0.1 to 30 μm, preferably 0.5 to 15 μm in terms of wet film thickness.

  The coating solution containing the active energy ray-curable resin is applied and dried, and then irradiated with active rays such as ultraviolet rays. The irradiation conditions are as described above. Although there is no restriction | limiting in particular in irradiation time, 0.1 second-5 minutes are preferable, and 0.1 second-1 minute are more preferable from the hardening efficiency of a curable resin, work efficiency, etc.

In order to prevent oxygen inhibition during curing and ensure surface hardness, a method of filling with an inert gas such as N ₂ and curing at an oxygen concentration of 5% or less is used. The oxygen concentration is preferably 3% or less.

  An organic solvent is preferably used for the coating solution containing the active energy ray-curable resin of the present invention. At this time, it is preferable to use a solvent having a property of dissolving or swelling the resin film because the adhesion between the coated layer and the resin film is excellent. As the solvent, the above-mentioned solvents are used.

  An optical film can be formed by coating an antireflective layer such as a high refractive index layer or a low refractive index layer on the hard coat layer produced by the method for producing a hard coat film of the present invention. An optical film with significantly improved is obtained.

Although the following example is mentioned as a layer structure of the optical film obtained by the manufacturing method of this invention, It does not specifically limit to these. Among these, at least one of the clear hard coat layer, the antiglare hard coat layer, the medium refractive index layer, the high refractive index layer, and the low refractive index layer is a layer that is cured by irradiation with active rays after coating and drying. I can do it. The antireflection layer may be formed by a sol-gel method using any metal alkoxide of Ti or Si, and a composition containing metal oxide fine particles such as Zr, Zn, Ti, Si, Sn, and In and a binder is coated. May be.
Back coat layer / resin film / clear hard coat layer / high refractive index layer / low refractive index layer back coat layer / resin film / clear hard coat layer / medium refractive index layer / high refractive index layer / low refractive index layer antistatic layer / Resin film / Clear hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Back coat layer / Resin film / Anti-glare hard coat layer / High refractive index layer / Low refractive index layer Back coat layer / Resin film / Anti-glare hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index layer Antistatic layer / Resin film / Anti-glare hard coat layer / Medium refractive index layer / High refractive index layer / Low refractive index Rate layer Since the optical film obtained by the present invention is excellent in flatness, an antireflection film or an antiglare film used in front of a liquid crystal display device, an organic EL display or a plasma display, or a clear film. It is useful as a hard coat film, can provide excellent visibility, and can provide a polarizing plate or a display device using these as a polarizing plate protective film.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to this Example.

<< Preparation of transparent resin film >>
(Dope composition)
Cellulose triacetate (acetyl substitution degree 2.88) 100 parts by weight Ethylphthalyl ethyl glycolate 5 parts by weight Tinuvin 109 (manufactured by Ciba Specialty Chemicals) 1 part by weight Tinuvin 171 (manufactured by Ciba Specialty Chemicals) 1 part by weight Silicon oxide fine particles (Aerosil 200V) 0.1 parts by weight Methylene chloride 430 parts by weight Methanol 90 parts by weight The above composition was put into a sealed container, kept at 80 ° C. under pressure and completely dissolved while stirring.

  Next, the dope composition was filtered, cooled and kept at 33 ° C., and evenly cast on a stainless steel band. After the solvent was evaporated until peeling became possible, the width was removed by a tenter after peeling from the stainless steel band. It is dried while gripping, stretched to 1.1 times in the width direction, and further dried while being transported by a large number of rolls to obtain a transparent resin film having a film thickness of 40 μm, a width of 1.5 m, and a length of 2000 m. Obtained.

  At this time, the surface in contact with the stainless steel band is defined as b surface, and the other surface is defined as a surface.

<< Formation of Back Coat Layer (BC Layer) >>
(Backcoat layer (BC layer) coating composition)
Acetone 72 parts by mass Methanol 18 parts by mass Propylene glycol monomethyl ether 10 parts by mass Diacetyl cellulose 0.5 parts by mass 2% acetone-dispersed ultrafine silica (Aerosil 200V manufactured by Nippon Aerosil Co., Ltd.)
0.1 parts by mass The back coating layer coating composition (viscosity: 2.0 mPa · s) was applied to the back surface of the transparent resin film using a die so that the wet film thickness was 13 μm, and the temperature was set to 80 ° C. It dried in the drying part and provided BC layer (dry film thickness: 0.5 micrometer). (Viscosity is the value measured with Toki Sangyo Co., Ltd. E type viscometer.)
<< Formation of clear hard coat layer (CHC layer) >>
(Clear hard coat layer (CHC layer) coating composition)
Dipentaerythritol hexaacrylate monomer 60 parts by mass Dipentaerythritol hexaacrylate dimer 20 parts by mass Dipentaerythritol hexaacrylate trimer or higher component 20 parts by mass Irgacure 184 (manufactured by Ciba Specialty Chemicals) 2 parts by mass Isopropyl alcohol 50 parts by mass Ethyl acetate 50 parts by mass Methyl ethyl ketone 50 parts by mass Extruding the clear hard coat layer coating composition (viscosity 5.9 mPa · s) onto the surface of the prepared transparent resin film (coater type: die, Degree of vacuum: -1000 Pa, coating liquid discharge rate: 21 g / m ² , coating speed: 50 m / min), and then adjusting the hot air temperature and air volume so that the residual solvent content after drying shown in Table 1 is obtained in the drying step Dried.

In the drying step 4, the temperature in the furnace is 70 ° C. until the drying is completed, and the film heat transfer number h20 W / m ² ° C. After drying, the furnace temperature 50 ° C., the film heat transfer number h 30 W / m ² ° C. The process was set up and dried continuously. Cooling step 5 is a zone in which the temperature of the coating film is adjusted at a temperature of 30 ° C. and a film heat transfer number of 30 W / m ² ° C., and the amount of residual solvent is fixed so as not to dry more than necessary.

The residual solvent content was calculated from the mass ratio before and after vacuum drying at 120 ° C. for 2 hours on a film coated with the coating film after drying using a vacuum dryer. (Using a FD-3-85MP vacuum dryer manufactured by Central Science Trading Co., Ltd., degree of vacuum: 0.5 Torr Pa, sample size: 100 mm × 100 mm)
Residual solvent amount% = (mass of sample after drying / mass of sample before drying) × 100
The mass of the sample after drying and the mass of the sample before drying were measured with an electronic balance GF-300 manufactured by Onishi Keiki Co., Ltd.

  After drying in the drying section, it was cooled with a cooling device, and the temperature of the coating film was adjusted to the temperature shown in Table 1. Thereafter, ultraviolet rays were irradiated using an ultraviolet irradiation facility. The illuminance and integrated light quantity are as shown in Table 1, and adjustment is performed by changing the lamp power, the shape of the lamp and diffuser plate or the transport speed of the transparent resin film, and a clear hard coat layer (CHC layer) with a thickness of 7 μm is formed. Hard coat film No. 1-26 were obtained. Curing was performed at an oxygen concentration of 3%.

An ultraviolet ray lamp (high pressure mercury type manufactured by Eye Graphic Co., Ltd.) was used as the actinic ray light source.
Evaluation The produced hard coat film No. The following evaluation was performed using 1-26, and the results are shown in Table 1 below.

<Evaluation of clear hard coat layer>
(Flatness)
Each sample is cut into a size of 90 cm in width and 100 cm in length at the center of 10 m from the start of application of each film, and a height of 1.5 m so that five 50 W fluorescent lamps are arranged and the sample stage can be illuminated from a 45 ° angle. The film samples were placed on a sample stage, 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 overall ×: Fluorescent lamps appear to swell greatly Result from the above Is shown in Table 1.

  Further, the produced hard coat film No. The following antireflection layer was formed using 3 to produce an antireflection film.

<Formation of multilayer antireflection layer>
(Medium refractive index layer coating composition)
Tetra (n) butoxytitanium 250 parts by mass Terminal reactive dimethyl silicone oil (L-9000, manufactured by Nihon Unicar)
0.48 parts by mass Aminopropyltrimethoxysilane (KBE903 manufactured by Shin-Etsu Chemical Co., Ltd.)
22 parts by mass UV curable epoxy resin (KR500 manufactured by Asahi Denka Co., Ltd.) 21 parts by mass Propylene glycol monomethyl ether 4900 parts by mass Isopropyl alcohol 4840 parts by mass (High refractive index layer coating composition)
Tetra (n) butoxytitanium 310 parts by mass Terminal reactive dimethyl silicone oil (L-9000, manufactured by Nihon Unicar Company)
0.4 parts by mass Aminopropyltrimethoxysilane (KBE903 manufactured by Shin-Etsu Chemical Co., Ltd.)
4.8 parts by mass UV curable epoxy resin (KR500 manufactured by Asahi Denka Co., Ltd.) 4.6 parts by mass Propylene glycol monomethyl ether 4900 parts by mass Isopropyl alcohol 4800 parts by mass (Preparation of tetraethoxysilane hydrolyzate A)
580 g of tetraethoxysilane and 1144 g of ethanol were mixed, and after adding an aqueous citric acid solution (in which 5.4 g of citric acid monohydrate was dissolved in 272 g of water), the mixture was stirred at 25 ° C. for 1 hour. Ethoxysilane hydrolyzate A was prepared.

(Low refractive index layer coating composition)
Tetraethoxysilane hydrolyzate A 1020 parts by mass Terminal reactive dimethyl silicone oil (L-9000, manufactured by Nihon Unicar)
0.42 parts by mass Propylene glycol monomethyl ether 2700 parts by mass Isopropyl alcohol 6300 parts by mass On the CHC layer of the hard coat film 3 having the above CHC layer, a medium refractive index layer was applied using a die, and after drying, it is shown in Table 2. It dried so that it might become the residual solvent content shown, and after drying in the drying part, it cooled with the cooling device and adjusted so that the temperature of a coating film might become the temperature shown in Table 2. Thereafter, ultraviolet rays were irradiated using an ultraviolet irradiation facility. The illuminance and integrated light amount were set as shown in Table 2, and the adjustment was performed by changing the lamp power, the shape of the lamp and the diffusion plate, or the conveyance speed of the transparent resin film. The high refractive index layer and the low refractive index layer were coated on the medium refractive index layer thus prepared using a die, and dried so that the residual solvent content after drying was 5%. After drying at a part, it was cooled with a cooling device, and the temperature of the coating film was adjusted to 30 ° C. Thereafter, ultraviolet rays were irradiated using an ultraviolet irradiation facility. The illuminance at this time was 300 mW / cm ² , and the integrated light quantity was 100 mJ / cm ² . Thus, each antireflection layer was cured to form a multilayer antireflection layer. Curing was performed at an oxygen concentration of 3%.

  At this time, the flow rate of the coating material from the coating head is adjusted so that the thickness of each layer is 0.075 μm for the middle refractive layer, 0.070 μm for the high refractive layer, and 0.093 μm for the low refractive index layer. Antireflection film No. having an antireflection layer 27-42 were produced.

  The refractive index and film thickness of each layer are determined from the measurement results of the spectral reflectance of the spectrophotometer for the sample coated with each layer alone. The spectrophotometer uses a U-4000 type (manufactured by Hitachi, Ltd.), and after roughening the back surface of the sample, it is light-absorbed with black spray to prevent reflection of light on the back surface, and is 5 degrees positive. The reflectance measurement in the visible light region (400 to 700 nm) is performed under the conditions of reflection. The refractive index of each completed layer was medium refractive index layer 1.65, high refractive index layer 1.90, and low refractive index layer 1.45.

Evaluation The produced antireflection film No. The following evaluation was performed using 27 to 42, and the results are shown in Table 2 below.

<Evaluation of antireflection film>
(Evaluation of uneven color)
A black acrylic plate is attached to the surface opposite to the antireflection layer coated on each of the antireflection films prepared above, and the antireflection layer coating surface side surface is irradiated with a strong white light source to visually observe color unevenness. The presence or absence of occurrence was confirmed, the acrylic plate was removed, the presence or absence of color unevenness due to transmitted light was confirmed, and color unevenness was evaluated according to the following criteria.

◎: No color unevenness is observed even with a black acrylic plate affixed ○: Extremely weak color unevenness is observed with a black acrylic plate affixed, but no color unevenness is observed by observation with transmitted light △: Black acrylic plate Color unevenness is observed in a part of the patch, but it is in a practically acceptable range. ×: Color unevenness is clearly recognized by observation with a black acrylic plate patch and transmitted light, and there is a problem in practical use. The results are shown in Table 2.

  As is clear from Tables 1 and 2, the optical film produced using the present invention has good flatness in the state in which a clear hard coat layer is applied to the comparative example, and further antireflection thereon. It can be seen that even when the layer is applied, color unevenness does not occur and the uniformity of the coating film is excellent. Furthermore, the optical film was not easily broken when forming an optical thin film.

It is a schematic diagram of the production apparatus which produces a coated material.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Production apparatus 2 Supply process 201 Coating object 202 Roll-shaped coating object 3 Coating process 301 Backup roll 302 Coating head 303 Decompression chamber 304 Coating apparatus 4 Drying process 401 Drying apparatus 402 Inlet port 403 Outlet port 5 Cooling process 501 Cooling apparatus 502 Entrance 503 Exit 6 Collection step 601 Roll-shaped coating 7 Active energy ray irradiation step 701 Active energy ray irradiation device

Claims (6)

On the support, a coating step of coating a coating solution containing an active energy ray-curable resin and a solvent to form a coating film;
A drying step of drying the coating film on the support after the coating step;
In the method for producing a hard coat film having an active energy ray irradiation step of irradiating the coating film on the support with an active energy ray after the drying step,
A method for producing a hard coat film, wherein the residual solvent content of the coating film is 3 to 15% by mass after the drying step and before the active energy ray irradiation step. The method for producing a hard coat film according to claim 1, wherein the temperature of the coating film after the drying step and before the active energy ray irradiation step is 15 to 80 ° C. 3. The hardware according to claim 1, wherein the active energy ray irradiation intensity in the active energy ray irradiation step is 50 to 350 mJ / cm ² in terms of an integrated light amount (an ultraviolet integrated energy amount in a wavelength range of 300 to 390 nm). A method for producing a coated film. In the said active energy ray irradiation process, the illumination intensity of an active energy ray is 200-600 mW / cm < ² >, The manufacturing method of the hard coat film of any one of Claims 1-3 characterized by the above-mentioned. An optical film comprising at least one coating film obtained by the method for producing a hard coat film according to claim 1. An antireflection film comprising at least one coating film obtained by the method for producing a hard coat film according to any one of claims 1 to 4.

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