JP2016036765A - Laminar film manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminar film manufacturing method for applying a coating layer containing metal oxide particles by using a gravure coating device, wherein the film thickness reduction of an application layer and the occurrence of a stream-like defect are suppressed.SOLUTION: A laminate film manufacturing method for applying an application liquid onto a base film to laminate a coating layer by using a coating equipment equipped with at least a gravure roll and a doctor blade is characterized: in that said coating layer contains metal oxide particles; in that the Vickers hardness (Hv1) of said gravure roll is at or more than 1200 and less than 2500; and in that the Vickers hardness (Hv2) of said doctor blade is at or more than 850 and less than 1200.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a laminated film in which a coating liquid is applied on a base film by using a gravure coating apparatus equipped with a gravure roll and a doctor blade, and in detail, the coating layer is a metal oxide. The present invention relates to a method for producing a laminated film that can suppress the occurrence of streak-like defects when particles are contained.

  The gravure coating method is generally known, and is particularly suitable for uniform coating of a thin film. The gravure roll is a roll in which cells are formed on the peripheral surface of the roll. The coating liquid supplied to the gravure roll is temporarily held in the cell, and after the excess coating liquid is scraped off by a doctor blade, the base is continuously transported. When the gravure roll comes into contact with the material film, the coating liquid in the cell is applied onto the base film.

  In the gravure coating apparatus, the doctor blade is arranged so as to be always in contact with the rotating gravure roll. For this reason, it has been proposed that the Vickers hardness of the gravure roll and / or doctor blade be in a specific range (Patent Documents 1 to 5).

  On the other hand, optical films provided with various functional layers (for example, functional layers such as an antireflection function, an antiglare function, a hard coat function, an antistatic function, and a color correction function) on a base film for image display devices and touch panels. Are used inside an image display surface or a display device (touch panel). These optical films are required to have high transmittance in addition to the above functions, but have few defects such as streaks and unevenness, and high thickness accuracy of the functional layer.

  Various functional layers constituting the optical film may contain metal oxide particles such as silicon oxide particles (silica particles) and zirconium oxide particles depending on the purpose and application.

JP 7-276601 A JP 2007-730 A JP 2010-240897 A JP 2013-1225876 A JP 2006-315399 A

  The coating method using the gravure roll is suitable for the thin film coating as described above, but on the other hand, since it is a coating method in which the thin film is formed while the base film and the gravure roll are in contact, There is a problem that defects are likely to occur.

  The above problem tends to occur when the coating layer contains metal oxide particles, and tends to occur as the coating layer becomes thinner.

  In addition, it is known that the hardness of the doctor blade is designed to be smaller than the hardness of the gravure roll, but this makes the doctor blade easy to wear, and when the doctor blade wears, the thickness of the coating layer decreases. Occur.

  Then, the objective of this invention suppresses generation | occurrence | production of the stripe defect of a coating layer in the manufacturing method of the laminated film which laminates | stacks the coating layer containing a metal oxide particle on a base film using a gravure coating apparatus. And to suppress a decrease in the thickness of the coating layer.

The above object of the present invention has been basically achieved by the following invention.
[1] A method for producing a laminated film in which a coating liquid is coated on a base film by using a gravure coating apparatus including at least a gravure roll and a doctor blade, and the coating layer is a metal oxide. A method for producing a laminated film, comprising particles, wherein the gravure roll has a Vickers hardness (Hv1) of 1200 or more and less than 2500, and the doctor blade has a Vickers hardness (Hv2) of 850 or more and less than 1200.
[2] The method for producing a laminated film according to [1], wherein the gravure roll has an outermost surface coated with diamond-like carbon.
[3] The method for producing a laminated film according to [1] or [2], wherein the doctor blade has an outermost surface coated with a nickel-based composite plating layer containing fluorine-based resin particles.
[4] The laminated film according to any one of [1] to [3], wherein the content of the metal oxide particles in the coating layer is 5 to 80% by mass with respect to 100% by mass of the total solid content of the coating layer. Manufacturing method.
[5] The method for producing a laminated film according to any one of [1] to [4], wherein the metal oxide particles are silicon oxide particles or zirconium oxide particles.
[6] The method for producing a laminated film according to any one of [1] to [5], wherein the coating layer further contains an active energy ray-curable resin.
[7] The base film has at least a thermosetting easy-adhesion layer containing a resin and a crosslinking agent, and a coating layer is laminated on the easy-adhesion layer. The manufacturing method of laminated film of description.

  According to the present invention, in the production of a laminated film in which a coating layer containing metal oxide particles is laminated on a base film using a gravure coating device, the occurrence of streaky defects in the coating layer is suppressed, and A decrease in the thickness of the coating layer can be suppressed.

  The method for producing a laminated film of the present invention is particularly suitably used for producing an optical film or a protective film for a display device or a touch panel.

FIG. 1 is a schematic view showing an example of a reverse gravure coating apparatus used in the present invention. FIG. 2 is a partial schematic cross-sectional view of a gravure roll used in the present invention. In order to explain the range of the bank portion in FIG. 2, the bank portion is indicated by a solid line, and the cell is indicated by a dotted line. FIG. 3 is a schematic sectional view of a doctor blade used in the present invention.

  The present invention is a method for producing a laminated film in which a coating liquid is coated on a base film by using a coating apparatus having at least a gravure roll and a doctor blade, and the coating layer is a metal oxide. A method for producing a laminated film, comprising particles, wherein the gravure roll has a Vickers hardness (Hv1) of 1200 or more and less than 2500, and the doctor blade has a Vickers hardness (Hv2) of 850 or more and less than 1200. Such an invention.

  First, the gravure coating apparatus according to the present invention will be described.

  The gravure coating apparatus of the present invention includes at least a gravure roll and a doctor blade, and the coating liquid supplied to the gravure roll is temporarily held in a cell formed on the peripheral surface of the gravure roll, and the excess coating liquid is scraped by the doctor blade. After being dropped, the gravure roll comes into contact with the continuously transported base film, whereby the coating liquid in the cell is transferred and applied onto the base film.

  The gravure coating apparatus used in the present invention is preferably a reverse method, and a reverse kiss method combining a reverse method and a kiss method (floating method) is preferably employed.

  The reverse gravure method is a method in which the rotation direction of the gravure roll is opposite to the conveyance direction of the continuously conveyed base film. The kiss method (floating method) is a method in which a back roll is not disposed at a position facing a gravure roll with a base film interposed therebetween.

  FIG. 1 is a schematic view showing an example of a gravure coating apparatus used in the present invention. This coating apparatus employs a reverse kiss method.

  The gravure coating apparatus includes a gravure roll 10, a coating liquid supply unit 20, a doctor blade 30, and a pair of transport rollers 41 and 42.

  The gravure roll 10 is driven and rotated in the direction of arrow y by a rotation driving means (not shown). The coating liquid supply means 20 includes a coating liquid storage container 21 and a coating liquid 22 accommodated in the coating liquid storage container 21. The pair of transport rollers 41 and 42 are arranged at predetermined intervals on both sides of the gravure roll 10, and the base film 50 is transported in the direction of arrow z with the gravure roll 10 being pressed.

  The gravure roll 10 is arranged so that the lower part thereof is immersed in the coating liquid 22 in the coating liquid storage container 21. By rotating the gravure roll 10, the coating liquid is supplied to the cells formed on the peripheral surface of the gravure roll 10, and the surplus coating liquid on the peripheral surface of the gravure roll 10 is scraped off by the doctor blade 30, and the amount of the coating liquid is reduced. Adjusted. The gravure roll 10 is pressed against the base film 50 while rotating the gravure roll 10 in the direction opposite to the conveying direction of the base film 50 (direction of arrow z) (direction of arrow y). The coating liquid in the cell is transferred to the base film 50 and applied.

  As described above, the gravure coating apparatus according to the present invention is a so-called direct method in which a gravure roll is pressed against a base film to apply a coating liquid, and an offset method (an offset between the gravure roll and the base film). The method of arranging rolls) is not included.

[Vickers hardness of gravure roll and doctor blade]
In the present invention, it is important to combine a gravure roll having a Vickers hardness (Hv1) of 1200 or more and less than 2500 and a doctor blade having a Vickers hardness (Hv2) of 850 or more and less than 1200. As a result, streaky defects in the coating layer containing metal oxide particles and a decrease in coating layer thickness can be suppressed.

  In the combination of the gravure roll and the doctor blade, when the Vickers hardness of the gravure roll is less than 1200, the gravure roll is likely to be worn, and as a result, streak-like defects and a reduction in the thickness of the coating layer are likely to occur. Become.

  When the Vickers hardness of the gravure roll is 2500 or more, the base film is likely to be scratched, and the doctor blade is likely to be worn, resulting in streak defects and a reduction in the thickness of the coating layer. It tends to happen.

  When the Vickers hardness of the doctor blade is less than 850, the doctor blade is likely to be worn, and as a result, streak-like defects and a reduction in the thickness of the coating layer are likely to occur.

  When the Vickers hardness of the doctor blade is 1200 or more, the gravure roll is likely to be worn, and as a result, stripe-like defects and film thickness reduction are likely to occur.

  From the viewpoint of further effectively suppressing streak-like defects of the coating layer containing metal oxide particles and a reduction in coating layer thickness, the Vickers hardness of the gravure roll is preferably 1300 or more, and more preferably 1400 or more. The upper limit Vickers hardness is preferably 2300 or less, and more preferably 2100 or less.

  Further, from the viewpoint of more effectively suppressing streak-like defects of the coating layer containing metal oxide particles and film thickness reduction of the coating layer, the Vickers hardness of the doctor blade is preferably 900 or more, more preferably 930 or more. preferable. The upper limit Vickers hardness is preferably 1150 or less, and more preferably 1100 or less.

  Furthermore, from the viewpoint of further effectively suppressing streak-like defects in the coating layer containing metal oxide particles and reduction in coating layer thickness, the Vickers hardness (Hv1) of the gravure roll and the Vickers hardness (Hv2) of the doctor blade ) Is preferably in the range of 100 to 1100, more preferably in the range of 200 to 1000, and particularly preferably in the range of 300 to 900.

[Gravure roll]
The gravure roll according to the present invention has a Vickers hardness (Hv1) of 1200 or more and less than 2500.

  It is generally known that a gravure roll is provided with a hard chromium (HCr) plating layer on the surface thereof, but the Vickers hardness of the gravure roll does not exceed 1200.

  In the gravure roll according to the present invention, a method for setting the Vickers hardness to 1200 or more is not particularly limited, and a known method can be used. For example, the surface of the gravure roll may be coated with diamond-like carbon (hereinafter sometimes abbreviated as “DLC”) or ceramic. In particular, since DLC has a small friction coefficient, it is preferable to coat the surface of the gravure roll with a DLC film.

  That is, in the present invention, it is preferable that the outermost surface of the gravure roll is coated with diamond-like carbon.

  A gravure roll is generally known in which cells are formed on the peripheral surface of a base material roll made of a material such as carbon steel, stainless steel, or carbon fiber, and can also be used in the present invention. The cells are formed by an etching method, an engraving method, a laser method, or the like directly on the base material roll or via a metal plating layer (metal plating layer of nickel, copper, titanium, chromium, etc.).

  The gravure roll used in the present invention is preferably coated with a DLC coating or a ceramic coating at least on the bank peripheral surface of the roll on which the cells are formed, and particularly preferably coated with a DLC coating. Thereby, a gravure roll having a Vickers hardness (Hv1) of 1200 or more and less than 2500 can be obtained.

  The ceramic coating can be coated by thermal spraying. As the ceramic sprayed material, for example, an oxide-based material (for example, alumina, titania, zirconia, chromia, yttria, or a compound containing these), or a carbide-based material (for example, tungsten carbide, chromium carbide, or these and cobalt) , Compounds containing nickel chromium, etc.). The thickness of the ceramic coating is preferably in the range of 0.5 to 30 μm, more preferably in the range of 1 to 20 μm.

  Subsequently, the gravure roll whose surface is coated with a DLC film will be described in detail below.

  The DLC film can be formed by, for example, an ion plating method, a sputtering method, a plasma CVD method, or the like, and the plasma CVD method is particularly preferable.

  A hydrocarbon gas such as methane, acetylene, propane, butane, hexane, benzene, and toluene is used as a raw material gas for forming the DLC film.

  The thickness and hardness of the DLC film can be adjusted by controlling the type and amount of the source gas, or by controlling conditions such as the degree of vacuum, high frequency voltage and pulse width.

  FIG. 2 is a partial schematic cross-sectional view showing a part of the gravure roll according to the present invention. The peripheral surface 2 of the gravure roll 1 is composed of a plurality of cells 3 and a bank portion 4 that partitions these cells (here, the range of the bank portion 4 will be described with reference to FIG. 2A. The part indicated by the solid line in FIG.

In the present invention, that the surface of the gravure roll is covered with the DLC film means that at least the bank portion 4 of the peripheral surface 2 of the gravure roll 1 is covered. The roll and doctor blade are placed in contact with each other, and the gravure roll is applied by pressing (contacting) the base film, and the bank part which is the contact part between the gravure roll and the doctor blade or the base film is DLC. It is important that it is coated with a coating.

  In the present invention, only the bank portion may be covered with the DLC coating, or both the bank portion and the inside of the cell may be covered with the DLC coating. From the viewpoint of improving the wear resistance of the gravure roll, it is preferable that both the bank portion and the inside of the cell are covered with the DLC film. That is, it is preferable that the entire exposed portion of the peripheral surface of the gravure roll is covered with the DLC film. Since the entire exposed portion of the peripheral surface of the gravure roll is covered with the DLC film, an effect of suppressing the occurrence of bubble defects can be expected.

  As described above, the DLC film is coated on the periphery of the gravure roll by ion plating, sputtering, plasma CVD, or the like. Covered with.

  The thickness of the DLC film is preferably 0.5 μm or more and more preferably 1 μm or more from the viewpoint of adjusting the Vickers hardness of the gravure roll to 1200 or more and less than 2500 and effectively suppressing the occurrence of streak-like defects. Particularly, 2 μm or more is preferable. The upper limit thickness is preferably 15 μm or less, more preferably 10 μm or less, and particularly preferably 5 μm or less from the viewpoint of the workability of the gravure roll and the coating stability.

  The DLC film only needs to be on the outermost surface of the gravure roll, and for example, a hard chrome (HCr) plating layer or a nickel plating is provided between the base material roll and the DLC film for the purpose of improving the adhesion with the base material roll or preventing rust. One or more other layers such as a layer may be provided.

  The gravure roll according to the present invention has cells (grooves) on the peripheral surface of the roll. The shape of the cell is not particularly limited, and for example, a generally known oblique line type, lattice type (rectangular shape), honeycomb type (tortoiseshell type), pyramid type, or the like can be adopted. Among the above cells, a hatched cell is particularly preferable.

  The hatched cell has a structure in which cells (grooves) are continuously connected in a spiral shape, and other cells (lattice type, honeycomb type (tortoise type), pyramid type) have a structure in which individual cells are independent. It has become.

  Due to the difference in the structure of the cells described above, the hatched cells tend to suppress the generation of bubbles relatively compared to other cells. This is because gravure rolls having slanted cells are effective in suppressing bubbles because the coating liquid held in the cells moves (flows) in the spiral direction when the gravure roll rotates. it seems to do. The generation of bubbles may cause streak-like defects.

  The gravure roll according to the present invention preferably has 150 or more cells per inch (25.4 mm). That is, it is preferable to have 150 or more cells (grooves) per inch (25.4 mm) in the rotational axis direction of the gravure roll. In particular, it is preferable to have 150 or more hatched cells per inch (25.4 mm).

  A gravure roll having 150 or more cells is effective from the viewpoint of uniformly coating the coating layer with a thin film. Here, the uniform coating layer means that the coating layer thickness in the coating width direction is uniform (the thickness profile in the coating width direction is uniform, that is, the variation is small).

  From the above viewpoint, the number of lines per inch (25.4 mm) of the cell is preferably 160 lines or more, more preferably 170 lines or more, and particularly preferably 190 lines or more. The upper limit of the number of lines is preferably 300 lines or less, and more preferably 250 lines or less. When it exceeds 300 lines, it is necessary to set the solid content concentration of the coating solution high, and when a coating solution containing metal oxide particles is applied, streak-like defects may easily occur.

  In the case of a gravure roll having a hatched cell, the cell depth of the hatched cell is preferably in the range of 10 to 60 μm, and more preferably in the range of 15 to 50 μm. Moreover, the inclination angle (angle with respect to the rotation axis direction of the gravure roll) of the hatched cell is preferably in the range of 30 to 70 degrees, more preferably in the range of 40 to 60 degrees.

  The outer diameter of the gravure roll is preferably 100 mm or less and more preferably 80 mm or less from the viewpoint of effectively suppressing the occurrence of streak-like defects. By setting the outer diameter of the gravure roll to 100 mm or less, it is presumed that the contact area with the base film is reduced and the occurrence of streak-like defects is suppressed. The lower limit of the outer diameter of the gravure roll is preferably 20 mm or more, and more preferably 30 mm or more from the viewpoint of ensuring coating stability. Here, the outer diameter of the gravure roll means an outer diameter based on the outermost surface (that is, bank portion) of the peripheral surface of the gravure roll.

[Doctor blade]
The doctor blade according to the present invention has a Vickers hardness (Hv1) of 850 or more and less than 1200. In the present invention, it is necessary that the Vickers hardness (Hv1) of at least the tip of the doctor blade, that is, the portion in contact with the gravure roll, be 850 or more and less than 1200.

  As a doctor blade, metal plates such as steel, carbon steel, SK material (carbon tool steel JIS G4401), Swedish steel, stainless steel and the like are generally used. However, the Vickers hardness of doctor blades made of these metal plates usually does not exceed 850.

  In the doctor blade according to the present invention, a method for setting the Vickers hardness to 850 or more is not particularly limited, and a known method can be used. For example, a method of coating the surface of the metal plate (base material plate) with a DLC film, a method of coating a nickel-based composite plating layer containing fluorine resin particles, or a nickel-based composite plating layer containing ceramic particles And the like. Among these, it is particularly preferable to coat a nickel-based composite plating layer containing fluorine-based resin particles.

  In the present invention, the composite plating layer does not mean a multilayer structure of two or more layers, but means a composite of fluororesin particles or ceramic particles and nickel.

  As the method for coating the DLC film, the same method as the method for coating the surface of the gravure roll with the DLC coating can be used.

  Examples of the fluorine-based resin particles used in the nickel-based composite plating layer containing the above-mentioned fluorine-based resin particles include, for example, tetrafluoroethylene resin, perfluoroalkoxy resin, fluorinated ethylenepropylene resin, and tetrafluoroethylene-perfluoroalkyl. Examples thereof include particles made of vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, trifluoroethylene chloride resin, vinylidene fluoride resin, fluorinated acrylic polymer, fluorinated methacrylic polymer, and the like. Among these, particles made of tetrafluoroethylene resin, perfluoroalkoxy resin, and fluorinated ethylenepropylene resin are preferable, and tetrafluoroethylene resin particles are particularly preferable.

  The average particle diameter of such fluororesin particles is suitably in the range of 0.1 to 5 μm.

  1-60 vol% is preferable, as for content of the fluorine-type resin particle in a nickel-type composite plating layer, 2-50 vol% is more preferable, and 5-40 vol% is more preferable.

Examples of the ceramic particles used for the nickel-based composite plating layer containing the ceramic particles include Al ₂ O ₃ , SiO ₂ , SiC, TiN, and the like. The average particle size of the ceramic particles is suitably in the range of 0.1 to 5 μm.

  The content of the ceramic particles in the nickel-based composite plating layer is preferably 0.5 to 50 vol%, more preferably 1 to 40 vol%, and further preferably 3 vol% to 30 vol%.

  Examples of the nickel-based metal used in the nickel-based composite plating layer include pure nickel, nickel-cobalt, nickel-iron, nickel-chromium, nickel-tungsten, nickel-manganese, nickel-tin, nickel-phosphorus, and nickel-boron. And alloys such as nickel-phosphorus-boron.

  The thickness of the DLC film is preferably in the range of 0.1 to 10 μm, and more preferably in the range of 0.5 to 5 μm.

  The thickness of the nickel-based composite plating layer containing the aforementioned fluorine-based resin particles is preferably in the range of 0.5 to 30 μm, and more preferably in the range of 1 to 20 μm.

  The thickness of the nickel-based composite plating layer containing the aforementioned ceramic particles is preferably in the range of 0.5 to 30 μm, and more preferably in the range of 1 to 20 μm.

  The above coating layer may be a single layer or a laminated structure of two or more layers, but is preferably a two-layer structure from the viewpoint of adjusting the Vickers hardness to a range of 850 or more and less than 1200. .

  In the case of a two-layer structure, it is preferable that at least the outermost surface has a nickel-based composite plating layer containing fluorine-based resin particles.

  FIG. 3 is a schematic cross-sectional view of a doctor blade preferably used in the present invention. FIG. 3 is a partial schematic cross-sectional view of the distal end portion of the doctor blade (the distal end portion in contact with the gravure roll).

  In the doctor blade according to FIG. 3, the first plating layer 6 and the second plating layer 7 are sequentially coated on the surface of the base material plate 5.

  As the base material plate 5, a metal plate such as steel, carbon steel, SK material (carbon tool steel JIS G4401), Swedish steel, stainless steel or the like is preferably used.

  As the first plating layer 6, a nickel-based composite plating layer containing the above-described ceramic particles or a normal nickel-based plating layer is preferably used.

  As the 2nd plating layer 7, the nickel type composite plating layer containing the above-mentioned fluorine-type resin particle is used preferably.

[Coating layer]
The coating layer according to the present invention contains metal oxide particles.

  The laminated film on which the coating layer of the present invention is laminated includes various optical films (antireflection film, antiglare film, transparent conductive film, transparent conductive film base film (refractive index adjusting film), infrared shielding film, ultraviolet absorption film. Films, color tone adjustment films, etc.) and protective films for display devices and touch panels (hard coat films, antifouling films, etc.).

  As for said optical film and protective film, various functional layers are laminated | stacked on the base film. For example, functional layers such as an antireflection layer, an antiglare layer, a conductive layer, a refractive index adjustment layer, an infrared absorption layer, an ultraviolet absorption layer, a color tone adjustment layer, a hard coat layer, and an antifouling layer are laminated on the base film. Yes.

  The functional layer may contain metal oxide particles depending on the purpose, and the coating layer according to the present invention is suitable for a functional layer containing metal oxide particles.

  Examples of the metal oxide particles contained in the coating layer according to the present invention include silicon oxide particles (silica particles), zirconium oxide particles, titanium oxide particles, zinc oxide particles, tin oxide particles, antimony oxide particles, and cerium oxide particles. , Iron oxide particles, zinc antimonate particles, tin oxide doped indium oxide (ITO) particles, antimony doped tin oxide (ATO) particles, phosphorus doped tin oxide particles, aluminum doped zinc oxide particles, gallium doped zinc oxide particles, fluorine doped tin oxide Particles and the like.

When the coating layer is, for example, a high refractive index layer constituting an antireflection layer or a high refractive index layer constituting a refractive index adjustment layer, the coating layer is made of metal oxide particles (for example, zirconium oxide particles, Containing titanium oxide particles, zinc oxide particles, tin oxide-doped indium oxide (ITO) particles, antimony-doped tin oxide (ATO particles), etc.)
When the coating layer is a low refractive index layer constituting the antireflection layer or a low refractive index layer constituting the refractive index adjustment layer, the coating layer has metal oxide particles (for example, silicon oxide particles; Silica particles),
When the coating layer is a conductive layer, the coating layer is a metal oxide particle having relatively high conductivity (for example, zinc oxide particles, tin oxide particles, antimony oxide particles, cerium oxide particles, iron oxide particles, zinc antimonate particles). , Tin oxide-doped indium oxide (ITO) particles, antimony-doped tin oxide (ATO) particles, phosphorus-doped tin oxide particles, aluminum-doped zinc oxide particles, etc.)
When the coating layer is a hard coat layer (a hard coat layer imparted with slipperiness or blocking resistance), the coating layer preferably contains silicon oxide particles (silica particles).

  Among the metal oxide particles described above, silicon oxide particles and zirconium oxide particles are preferably used from the viewpoint of effectively expressing the function of the functional layer while maintaining high transparency. Therefore, the present invention can be particularly preferably applied when the metal oxide particles are silicon oxide particles or zirconium oxide particles.

  The average particle diameter of the metal oxide particles contained in the coating layer is preferably smaller from the viewpoint of uniformly forming the coating layer with a thin film and suppressing the occurrence of streak-like defects. Specifically, the average particle diameter of the metal oxide particles is preferably 0.5 μm or less, more preferably 0.2 μm or less, particularly preferably 0.1 μm or less, and most preferably 0.08 μm or less. The lower limit of the average particle diameter is about 0.005 μm.

  Further, from the viewpoint of uniformly forming the coating layer with a thin film and suppressing the occurrence of streak-like defects, the average particle diameter (r of the metal oxide particles with respect to the thickness (dry thickness) (d: μm) of the coating layer : Μm) is preferably 1.3 or less, more preferably 1.0 or less, and particularly preferably 0.9 or less. The lower limit of the ratio (r / d) is about 0.01.

  The content of the metal oxide particles in the coating layer is preferably 5% by mass or more, preferably 10% by mass or more with respect to 100% by mass of the total solid content of the coating layer, from the viewpoint of effectively expressing the function of the functional layer described above. Is more preferable, and 15% by mass or more is particularly preferable. As described above, as the content of the metal oxide particles contained in the coating layer increases, streak-like defects tend to occur, but by using the gravure coating apparatus according to the present invention described above, Occurrence is suppressed.

  The upper limit of the content of the metal oxide particles in the coating layer is preferably 80% by mass or less, more preferably 75% by mass or less, and particularly preferably 70% by mass or less with respect to 100% by mass of the total solid content of the coating layer. When the content of the metal oxide particles exceeds 80% by mass, streaky defects are likely to occur.

  The coating layer according to the present invention preferably contains a resin. When the coating layer contains a resin, the coating property of the coating layer is improved, the metal oxide particles are uniformly dispersed and retained, a relatively robust coating is formed, and the base film Effects such as improved adhesion to the coating layer can be obtained.

  Although it does not specifically limit as resin contained in a coating layer, A thermosetting resin and an active energy ray curable resin are preferable, and an active energy ray curable resin is especially preferable.

  The thermosetting resin is a resin that is polymerized or cross-linked by heat. For example, acrylic resin, polyester resin, polyurethane resin, polycarbonate resin, polystyrene resin, polyolefin resin, fluorine resin, polyimide resin, etc. can give. After applying a coating solution containing these thermosetting resins, it is cured by heating.

  The active energy ray-curable resin is a resin that is polymerized and cured by active energy rays such as ultraviolet rays and electron beams, and examples thereof include monomers and oligomers having at least one ethylenically unsaturated group in the molecule. Here, examples of the ethylenically unsaturated group include an acryloyl group, a methacryloyl group, a vinyl group, and an allyl group. After applying a coating solution containing these active energy ray-curable resins, the active energy ray is cured by irradiation.

  Examples of monomers having at least one ethylenically unsaturated group in the molecule include methyl (meth) acrylate, lauryl (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, Phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxy-3-phenoxy (meth) acrylate Monofunctional acrylates such as neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Ritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, Multifunctional acrylates such as tripentaerythritol tri (meth) acrylate, tripentaerythritol hexa (meth) triacrylate, trimethylolpropane (meth) acrylic acid benzoate, trimethylolpropane benzoate, glycerin di (meth) acrylate hexa Urethane acrylates such as methylene diisocyanate, pentaerythritol tri (meth) acrylate hexamethylene diisocyanate Mention may be made of a door or the like.

  Examples of oligomers having at least one ethylenically unsaturated group in the molecule include polyester (meth) acrylate, polyurethane (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate, and alkit (meta ) Acrylate, melamine (meth) acrylate, silicone (meth) acrylate and the like.

  The above-mentioned monomers and oligomers having at least one ethylenically unsaturated group in the molecule may be used alone or in combination. It is preferable to use at least a trifunctional or higher polyfunctional monomer or polyfunctional oligomer.

  The content of the resin in the coating layer is the above-mentioned effect (for example, that the coating property of the coating layer is improved, that the metal oxide particles are uniformly dispersed and held, a relatively robust coating is formed, And 10% by mass or more, preferably 15% by mass or more with respect to 100% by mass of the total solid content of the application layer, from the viewpoint of effectively expressing the adhesion between the base film and the application layer). More preferred is 20% by mass or more. The upper limit content is preferably 90% by mass or less.

  When the coating layer contains an active energy ray-curable resin as a resin, the coating layer preferably further contains a photopolymerization initiator. Specific examples of such a photopolymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, benzophenone, 2-chlorobenzophenone, 4,4′-dichloro. Benzophenone, 4,4′-bisdiethylaminobenzophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, methylbenzoyl formate, p-isopropyl-α-hydroxyisobutylphenone, α-hydroxyisobutylphenone, Carbonyl compounds such as 2,2-dimethoxy-2-phenylacetophenone and 1-hydroxycyclohexyl phenyl ketone, tetramethylthiuram monosulfide, Sulfur compounds such as tetramethylthiuram disulfide, thioxanthone, 2-chlorothioxanthone, and 2-methylthioxanthone can be used.

  Moreover, generally the photoinitiator is marketed and they can be used. For example, Irgacure 184, 907, Irgacure 379, Irgacure 819, Irgacure 127, Irgacure 500, Irgacure 754, Irgacure 250, Irgacure 1800, Irgacure 1870, Irgacure OXE01, DAROCURT, POROCURUR, manufactured by Ciba Specialty Chemicals Co., Ltd. SPEEDCURE MBB, SPEEDCURE PBZ, SPEEDCURE ITX, SPEEDCURE CTX, SPEEDCURE EDB, YK AC, Y K-AC, ACC RE DMBI etc. are mentioned.

  These photopolymerization initiators may be used alone or in combination of two or more.

  The content of the photopolymerization initiator in the coating layer is suitably in the range of 0.1 to 10% by weight and preferably in the range of 0.5 to 8% by weight with respect to 100% by weight of the total solid content of the coating layer.

  The coating layer can further contain additives such as a leveling agent, an antifouling agent, a lubricant, a colorant, an antioxidant, and an ultraviolet absorber.

  The coating layer is obtained by coating a coating film for forming the coating layer (hereinafter referred to as “coating liquid”) on the base film. The coating solution coated on the base film is dried and cured (cured by heat curing or irradiation with active energy rays) as necessary to form a coating layer.

  The coating liquid according to the present invention contains at least metal oxide particles. The coating solution preferably further contains the aforementioned resin, and can contain the aforementioned photopolymerization initiator and various additives. These components are dissolved or dispersed in an organic solvent and / or an aqueous solvent to prepare a coating solution.

  The solid content concentration of the coating solution is preferably in the range of 0.5 to 50% by mass, and more preferably in the range of 1 to 40% by mass.

  The coating solution preferably has a relatively low viscosity. Specifically, the viscosity (23 ° C.) of the coating solution is preferably 30 mPa · s or less, more preferably 20 mPa · s or less, and particularly preferably 10 mPa · s or less. The lower limit viscosity of the coating solution is about 0.3 mPa · s.

Further, Wet coating amount of the coating liquid is preferably in the range of 0.5 to 20 g / ^{m 2,} more preferably in the range of 1 to 10 g / ^{m 2,} in particular in the range of 1 to 7 g / ^{m 2} is preferred.

The present invention is more effective as the coating layer is a thin film. In other words, when a coating layer containing metal oxide particles is applied as a thin film using a gravure coating device, streak-like defects tend to occur, but by using the gravure coating device of the present invention, the occurrence of streak-like defects occurs. Is suppressed.
Therefore, the thickness (dry thickness) of the coating layer is more preferable as it is a thin film. Specifically, the thickness (dry thickness) of the coating layer is preferably 2.5 μm or less, more preferably 1.7 μm or less, and particularly preferably 1.0 μm or less. The lower limit of the thickness (dry thickness) of the coating layer is preferably 0.01 μm or more, and more preferably 0.02 μm or more from the viewpoint of stably ensuring uniform coating properties.
The present invention is particularly effective when the thickness of the coating layer (dry thickness) is extremely thin. Here, the ultrathin film means less than 50 nm. The minimum thickness of the ultrathin film is about 10 nm.

[Base film]
As the base film according to the present invention, polyester resin film, cellulose resin film, polyolefin resin film, acrylic resin film, polycarbonate resin film, cyclic olefin resin film, epoxy resin film, polyimide resin film, polyetherimide resin film, polyamide Examples thereof include a resin film, a polysulfone resin film, a polyphenylene sulfide resin film, and a polyether sulfone resin film. Among these resin films, polyester resin films are preferable, and biaxially stretched polyethylene terephthalate (PET) films are particularly preferable because they are particularly excellent in physical properties (strength, wear resistance, etc.) and solvent resistance.

  The thickness of the base film is suitably in the range of 10 to 300 μm, preferably in the range of 15 to 250 μm, particularly preferably in the range of 20 to 200 μm.

  The base film is preferably provided with an easy-adhesion layer in advance in order to improve adhesion with the coating layer.

  The easy adhesion layer is preferably a layer containing a resin. The content of the resin in the easy adhesion layer is preferably 30% by mass or more, more preferably 50% by mass or more, and more preferably 60% by mass or more with respect to 100% by mass of the total solid content of the easy adhesion layer. It is particularly preferred. The upper limit is preferably 98% by mass or less, more preferably 95% by mass or less, and particularly preferably 90% by mass or less.

  Examples of the resin constituting the easy adhesion layer include polyester resin, acrylic resin, urethane resin, polycarbonate resin, epoxy resin, alkyd resin, urea resin, and the like. These resins can be used alone or in combination.

  From the viewpoint of improving the adhesion to the coating layer, it is preferable to use at least one selected from the group consisting of a polyester resin, an acrylic resin and a polyurethane resin as the resin contained in the easy-adhesion layer.

  The easy-adhesion layer preferably further contains a crosslinking agent. That is, in the present invention, it is preferable that the base film has a thermosetting easy-adhesion layer containing at least a resin and a crosslinking agent, and the coating layer is laminated on the easy-adhesion layer.

  Moreover, it is preferable that an easily bonding layer is a thermosetting layer containing the above-mentioned resin and a crosslinking agent, and being hardened by heat. By making the easy-adhesion layer such a thermosetting layer, the adhesion between the base film and the coating layer can be further improved. The conditions (heating temperature, time) for thermosetting the easy-adhesion layer are not particularly limited, but the heating temperature is preferably 70 ° C or higher, more preferably 100 ° C or higher, particularly preferably 150 ° C or higher, and most preferably 200 ° C or higher. preferable. The upper limit is preferably 300 ° C. or lower. The heating time is preferably in the range of 5 to 300 seconds, and more preferably in the range of 10 to 200 seconds.

  Examples of the crosslinking agent include melamine crosslinking agent, oxazoline crosslinking agent, carbodiimide crosslinking agent, isocyanate crosslinking agent, aziridine crosslinking agent, epoxy crosslinking agent, methylolated or alkylolized urea crosslinking agent, acrylamide Examples thereof include system crosslinking agents, polyamide resins, amide epoxy compounds, various silane coupling agents, and various titanate coupling agents. Among these, melamine crosslinking agents, oxazoline crosslinking agents, carbodiimide crosslinking agents, isocyanate crosslinking agents, aziridine crosslinking agents, and epoxy crosslinking agents are preferable, and melamine crosslinking agents are particularly preferable.

  The content of the crosslinking agent in the easy-adhesion layer is preferably in the range of 0.5 to 30% by mass, more preferably in the range of 1 to 25% by mass, especially 2 to 2% with respect to 100% by mass of the total solid content of the easy-adhesion layer. A range of 20% by weight is preferred.

  The easy-adhesion layer can contain metal oxide particles such as titanium oxide and zirconium oxide in order to design the refractive index relatively high. The content of these metal oxide particles in the easy-adhesion layer is appropriately adjusted according to the target refractive index of the easy-adhesion layer, specifically 10 to 10% by mass relative to the total solid content of 100% by mass of the easy-adhesion layer. It is preferable to adjust in the range of 60 mass%.

  The easy adhesion layer preferably contains particles (slippery particles) from the viewpoint of ensuring appropriate slipperiness in the production process of the laminated film. The average particle diameter of such particles (easy-sliding particles) is preferably larger than the thickness of the easy-adhesion layer. Specifically, the average particle diameter of the particles is preferably 1.1 times or more the thickness of the easy-adhesion layer, 1.3 times or more is more preferable, and 1.5 times or more is particularly preferable.

  Although it does not specifically limit as particle | grains (easy-slipper particle | grains) contained in an easily bonding layer, Organic particles, such as inorganic particles, such as a silica and a zeolite, an acrylic particle, a silicone particle, a polyimide particle, a Teflon (trademark) particle, are mentioned. It is done. Among these, silica particles are preferable, and colloidal silica is particularly preferable.

  The content of particles (slidable particles) in the easy-adhesion layer is preferably in the range of 0.1 to 4% by mass, and 0.5 to 3% by mass with respect to 100% by mass of the total solid content of the easy-adhesion layer. A range is more preferred.

  The thickness of the easy adhesion layer is preferably in the range of 10 to 200 nm, particularly preferably in the range of 15 to 150 nm.

  The base film provided with the easy-adhesion layer in advance improves the adhesion with the coating layer. On the other hand, in order to improve the adhesion with the coating layer, the cross-linking degree and hardness of the easy-adhesion layer are designed to be relatively small. When a coating layer containing product particles is applied using a gravure coating apparatus, the occurrence of streak-like defects may be promoted. However, this problem is suppressed by using the gravure coating apparatus according to the present invention.

[Production method of laminated film]
The method for producing a laminated film according to the present invention is applied by directly applying a coating liquid containing metal oxide particles on a base film using a gravure coating apparatus including at least the above-described gravure roll and doctor blade. It is a manufacturing method of the laminated | multilayer film which laminates | stacks a layer.

  In the manufacturing method of this invention, after apply | coating a coating liquid on a base film, this coating liquid is dried, It is preferable to make it harden | cure with a heat | fever or an active energy ray as needed, and to form a coating layer.

  In the present invention, a wider coating width is preferable from the viewpoint of improving productivity. Specifically, the coating width is preferably 1000 mm or more, more preferably 1300 mm or more, and particularly preferably 1500 mm or more. The upper limit coating width is about 2500 mm.

  As described above, when the coating width is increased, streak-like defects are likely to occur. However, by adopting the manufacturing method of the present invention, it is possible to effectively suppress the occurrence of streak-like defects even when the coating width is wide. it can.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these Examples. The measurement method, evaluation method, and materials used in this example are shown below.

[Measurement method and evaluation method]
(1) Measurement of Vickers hardness of gravure roll and doctor blade It measured according to JIS Z2244 (2009). Measurement was performed at 5 points and averaged.

(2) Measurement of thickness (dry thickness) of easy-adhesion layer and coating layer A cross section at the center in the coating width direction of the base film or laminated film was cut into an ultra-thin section, and a transmission electron microscope (H-7100FA model made by Hitachi) The cross section of the laminated film was observed at a magnification of 50,000 to 300,000 at an acceleration voltage of 100 kV, and the thicknesses of the easy-adhesion layer and the coating layer were measured. In addition, when the boundary of each layer was not clear, the dyeing | staining process was performed as needed.

(3) Measurement of average particle diameter of metal oxide particles contained in coating layer The cross section of the coating layer was observed with a TEM (transmission electron microscope) (approximately 10,000 to 100,000 times). The maximum length of each of the 30 particles selected for the purpose was measured, and a value obtained by averaging them was taken as the average particle diameter of the metal oxide particles.

(4) Measurement of average particle diameter of particles contained in easy-adhesion layer The cross section of the easy-adhesion layer laminated on the base film was observed with a TEM (transmission electron microscope) (about 10,000 to 100,000 times), From the cross-sectional photograph, the maximum length of each of 30 randomly selected particles was measured, and the average value of these was taken as the average particle diameter of the particles.

(5) Measurement of refractive index of coating layer The coating solution (dry thickness of about 2 μm) formed by applying each coating solution constituting the coating layer on a silicon wafer with a spin coater was measured under a temperature condition of 25 ° C. The refractive index of 589 nm was measured with a phase difference measuring device (Nikon Corporation: NPDM-1000).

(6) Evaluation of streaky defects When 10,000 m was applied, the streaky defects of the laminated film were evaluated.

The surface on which the coating layer of the laminated film was laminated by the following methods i) and ii) was observed, the number of streaky defects was examined, and the results of i) and ii) were averaged. Each observation area is 30 m ² . The evaluation criteria are shown below.
<Observation method>
i) The surface on which the coating layer of the laminated film is laminated is illuminated with an LED lamp and visually observed.
ii) The surface on which the coating layer of the laminated film is laminated is illuminated with a three-wavelength fluorescent lamp and visually observed.
<Evaluation criteria>
G1; the number of stripe-like defects is less than 0.5 / m ² G2; the number of stripe-like defects is 0.5 / m ² or more and less than 1.0 / m ² G3; the number of stripe-like defects is 1.0 / m ² to 2.0 pieces / ^{m 2} less than G4; striped defects number is 2.0 pieces / ^{m 2} to 5.0 pieces / ^{m 2} less than G5; striped defects number is 5.0 pieces / ^{m 2} or more 10 Less than 0.0 / m ² G6; The number of streaky defects is 10.0 / m ² or more.

(7) Evaluation of decrease in coating layer thickness The coating layer thickness (A) at the coating start point (when applied 200 m from the start of coating) and the coating layer thickness (B) when applied 10,000 m from the start of coating. It measured according to the method of said (2), and the reduction | decrease rate of the coating layer film thickness was calculated | required by the following formula | equation 1. {(A−B) / A} × 100 (1)

[Gravure roll]
<Gravure rolls a1 to a5 whose surfaces are coated with a DLC film>
Prepare a roll with 190 diagonal lines formed on the circumference of a stainless steel base roll, apply hard chrome (HCr) plating to the circumference of this roll, and then apply DLC on the surface. The film was coated by a plasma CVD method. Under the present circumstances, the gravure rolls a1-a5 which have the following Vickers hardness were manufactured by controlling the kind (methane or benzene) and introduction amount of hydrocarbon gas.

Gravure roll a1: Vickers hardness is 1400
Gravure roll a2: Vickers hardness is 2000
Gravure roll a3: Vickers hardness is 2300
Gravure roll a4: Vickers hardness is 2700
Gravure roll a5: Vickers hardness is 1100.

Each of the gravure rolls a1 to a5 has an outer diameter of 70 mm, a surface length of 1800 mm, a coating width of 1500 mm, and a slanted cell with an inclination angle of 45 degrees. <A gravure roll coated with a ceramic coating on its surface a6>
A roll having 190-line diagonal cells formed on the peripheral surface of a base material roll made of stainless steel was prepared, and tungsten carbide was sprayed on the peripheral surface of the roll to coat the ceramic coating. This gravure roll had an outer diameter of 70 mm, a surface length of 1800 mm, a coating width of 1500 mm, a slanted cell with an inclination angle of 45 degrees, and a Vickers hardness of 1500.

<Gravure roll a7>
A roll having a 190-line oblique cell formed on the circumference of a stainless steel base metal roll was prepared, and hard chromium (HCr) plating was applied to the circumference of the roll to coat an HCr film. . This gravure roll had an outer diameter of 70 mm, a surface length of 1800 mm, a coating width of 1500 mm, a slanted cell with an inclination angle of 45 degrees, and a Vickers hardness of 830.

<Gravure rolls b1-b7>
In the gravure rolls a1 to a7, gravure rolls b1 to b7 were produced in the same manner as the gravure rolls a1 to a7, except that the number of lines was changed to 230 lines. The Vickers hardness of the gravure rolls b1 to b7 is as follows.

Gravure roll b1: Vickers hardness is 1400
Gravure roll b2: Vickers hardness is 2000
Gravure roll b3: Vickers hardness is 2300
Gravure roll b4: Vickers hardness is 2700
Gravure roll b5: Vickers hardness is 1100
Gravure roll b6: Vickers hardness is 1500
Gravure roll b7: Vickers hardness is 830.

[Doctor blade]
<Doctor blade c1>
Nickel plating was applied to the tip of a base plate made of carbon steel, and nickel plating containing fluorine-based resin particles (tetrafluoroethylene particles; PTFE particles) was applied thereon to produce a doctor blade c1. The doctor blade had a Vickers hardness of 950.

<Doctor blade c2>
Nickel plating containing ceramic particles (SiC particles) is applied to the tip of a base plate made of carbon steel, and nickel plating containing fluorine resin particles (tetrafluoroethylene particles; PTFE particles) is applied thereon. The doctor blade c2 was manufactured. The doctor blade had a Vickers hardness of 1100.

<Doctor blade c3>
Nickel plating containing ceramic particles (SiC particles) was applied to the tip of a base plate made of carbon steel, and nickel plating was applied thereon to produce a doctor blade c3. The doctor blade had a Vickers hardness of 900.

<Doctor blade c4>
Nickel plating was applied to the tip of a base plate made of carbon steel to produce a doctor blade c4. The doctor blade had a Vickers hardness of 800.

<Doctor blade c5>
A doctor blade c5 made of carbon steel was prepared. The doctor blade had a Vickers hardness of 600.

<Doctor blade c6>
A hard chromium (HCr) plating was applied to the tip of a base plate made of carbon steel, and a DLC film was coated thereon by a plasma CVD method to produce a doctor blade c6. The doctor blade had a Vickers hardness of 1300.

[Example 1]
A laminated film was produced in the following manner.

<Manufacture of base film (biaxially stretched PET film with easy-adhesion layer laminated)>
Polyethylene terephthalate containing no particles is melt-extruded at 280 ° C., cast onto an electrostatically applied 20 ° C. cast drum to form an unstretched sheet, preheated at 100 ° C., and then stretched by roll stretching at this temperature. Stretched 3.0 times in the direction. Thereafter, the following water-based paint for an easy-adhesion layer was applied to both surfaces of the film. Thereafter, the film was stretched 3.5 times in the width direction at 120 ° C. and heat-treated at 220 ° C. Thereby, a biaxially stretched PET film (width 1600 mm, thickness 100 μm) in which a thermosetting easy adhesion layer having a dry thickness of 80 nm was laminated on both surfaces was obtained.

<Water-based paint for easy adhesion layer>
100 parts by mass of the following polyester resin A, 15 parts by mass of a melamine-based cross-linking agent (methylol-type melamine-based cross-linking agent (“Nicarac MW12LF” manufactured by Sanwa Chemical Co., Ltd.)) and particles (average particle size is 0.19 μm) This is an aqueous dispersion containing 2 parts by mass of colloidal silica particles.

<Polyester resin A>
A polyester resin having the following copolymer composition.
・ Carboxylic acid component terephthalic acid 35mol%
2,6-Naphthalenedicarboxylic acid 9 mol%
5-Na sulfoisophthalic acid 6 mol%
・ Glycol component ethylene glycol 49 mol%
Diethylene glycol 1 mol%.

<Lamination of coating layer>
Using the reverse gravure coating apparatus, gravure roll a1 and doctor blade c1 of FIG. 1, the following coating is applied directly on one easy-adhesive layer of a base film (biaxially stretched PET film on which an easy-adhesive layer is laminated). The liquid 1 was applied, dried at 90 ° C., and then cured by irradiation with ultraviolet rays of 400 mJ / cm ² to form a coating layer (hard coat layer) having a dry thickness of 1.6 μm. The refractive index of this coating layer was 1.52.

<Coating liquid 1>
84 parts by mass of active energy ray-curable resin (42 parts by mass of dipentaerythritol hexaacrylate, 42 parts by mass of urethane acrylate oligomer (“UN-901T” from Negami Industrial Co., Ltd.)), the following metal oxide particles (surface-treated silica) Disperse 11 parts by weight of the particle dispersion Z) in terms of solid content and 5 parts by weight of a photopolymerization initiator (“Irgacure (registered trademark) 184” manufactured by Ciba Specialty Chemicals) in an organic solvent (methyl isobutyl ketone). Alternatively, it is a dissolved coating solution. The coating solution has a solid content concentration of 30% by mass and a viscosity of 5 mPa · s (23 ° C.).

<Metal oxide particles (surface-treated silica particle dispersion Z)>
Colloidal silica particles (“organosilica sol IPA-ST-ZL” manufactured by Nissan Chemical Industries, Ltd., average particle size 0.13 μm) in 330 parts by mass, acryloyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) 8 masses Then, 2 parts by mass of tridecafluorooctyltrimethoxysilane (GE Toshiba Silicone Co., Ltd.) and 1.5 parts by mass of diisopropoxyaluminum ethyl acetate were added and mixed, and then 9 parts of ion-exchanged water was added. After making it react at 60 degreeC for 8 hours, it cooled to room temperature and added 1.8 mass parts of acetylacetone. Next, while adding cyclohexanone to this dispersion, solvent displacement was performed by distillation under reduced pressure at a pressure of 20 kPa to obtain a dispersion.

[Examples 2-8 and Comparative Examples 1-9]
In Example 1, each laminated film was produced in the same manner as in Example 1 except that the type of gravure roll and the type of doctor blade were changed as shown in Table 1.

[Evaluation]
About the laminated | multilayer film manufactured by said Example and comparative example, the stripe defect and the film thickness reduction rate of the coating layer were evaluated. The results are shown in Table 1.

[Example 11]
A laminated film was produced in the following manner.

<Manufacture of base film (biaxially stretched PET film with easy-adhesion layer laminated)>
Polyethylene terephthalate containing no particles is melt-extruded at 280 ° C., cast onto an electrostatically applied 20 ° C. cast drum to form an unstretched sheet, preheated at 100 ° C., and then stretched by roll stretching at this temperature. Stretched 3.0 times in the direction. Thereafter, the following water-based paint for an easy-adhesion layer was applied to both surfaces of the film. Thereafter, the film was stretched 3.5 times in the width direction at 120 ° C. and heat-treated at 220 ° C. As a result, a biaxially stretched PET film (width 1600 mm, thickness 100 μm) in which a thermosetting easy-adhesion layer having a dry thickness of 20 nm was laminated on both surfaces was obtained.

<Water-based paint for easy adhesion layer>
100 parts by mass of the above polyester resin A, 60 parts by mass of zirconium oxide particles having an average particle diameter of 15 nm, melamine-based crosslinking agent (methylol-type melamine-based crosslinking agent (“Nikalac MW12LF” manufactured by Sanwa Chemical Co., Ltd.)) Is an aqueous dispersion containing 15 parts by mass and 2 parts by mass of particles (colloidal silica having an average particle diameter of 0.19 μm).

<Lamination of coating layer>
Using the reverse gravure coating apparatus, gravure roll b1 and doctor blade c1 of FIG. 1, the following coating is applied directly on one easy-adhesion layer of a base film (biaxially stretched PET film on which an easy-adhesion layer is laminated). The liquid 2 was applied, dried at 90 ° C., and then cured by irradiation with ultraviolet light 400 mJ / cm ² to form a coating layer (high refractive index layer) having a set thickness of 45 nm (0.045 μm). The refractive index of this coating layer was 1.65.

<Coating liquid 2>
47 parts by mass of active energy ray-curable resin (dipentaerythritol hexaacrylate), 50 parts by mass of metal oxide particles (zirconium oxide particles having an average particle size of 30 nm), and a photopolymerization initiator (Ciba Specialty Chemicals Co., Ltd.) 3 parts by mass of “Irgacure (registered trademark) 184” manufactured in the art was prepared by dispersing and dissolving in an organic solvent (propylene glycol monoethyl ether). The coating solution has a solid content concentration of 2% by mass and a viscosity of 1 mPa · s (23 ° C.).

[Examples 12 to 18 and Comparative Examples 11 to 19]
In Example 11, each laminated film was produced in the same manner as in Example 11 except that the type of gravure roll was changed as shown in Table 2.

[Evaluation]
About the laminated | multilayer film manufactured by said Example and comparative example, the stripe defect and the film thickness reduction rate of the coating layer were evaluated. The results are shown in Table 2.

DESCRIPTION OF SYMBOLS 1, 10 Gravure roll 2 Gravure roll peripheral surface 3 Cell 4 Bank part 5 Base material plate constituting doctor blade 6 First plating layer constituting doctor blade 7 Second plating layer constituting doctor blade 20 Coating liquid supply means DESCRIPTION OF SYMBOLS 21 Coating liquid storage container 22 Coating liquid 30 Doctor blade 41, 42 A pair of conveyance roller 50 Base film

Claims (7)

  A method for producing a laminated film in which a coating liquid is coated on a base film by using a coating apparatus having at least a gravure roll and a doctor blade, and the coating layer is laminated, wherein the coating layer contains metal oxide particles. The method for producing a laminated film, wherein the gravure roll has a Vickers hardness (Hv1) of 1200 or more and less than 2500, and the doctor blade has a Vickers hardness (Hv2) of 850 or more and less than 1200. The method for producing a laminated film according to claim 1, wherein an outermost surface of the gravure roll is coated with diamond-like carbon.   The said doctor blade is a manufacturing method of the laminated | multilayer film of Claim 1 or 2 with which the outermost surface is coat | covered with the nickel type composite plating layer containing a fluorine resin particle.   The manufacturing method of the laminated | multilayer film in any one of Claims 1-3 whose content of the metal oxide particle in a coating layer is 5-80 mass% with respect to 100 mass% of solid content total amount of a coating layer.   The manufacturing method of the laminated | multilayer film in any one of Claims 1-4 whose metal oxide particle is a silicon oxide particle or a zirconium oxide particle.   The manufacturing method of the laminated | multilayer film in any one of Claims 1-5 in which an application layer contains active energy ray curable resin further.   The laminated film according to any one of claims 1 to 6, wherein the base film has a thermosetting easy-adhesive layer containing at least a resin and a crosslinking agent, and an application layer is laminated on the easy-adhesive layer. Production method.

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