JP6546992B2 - Release processing method, method of manufacturing antireflective film, and release processing apparatus - Google Patents

Description

  The present invention relates to a mold release treatment method, a method of manufacturing an antireflective film, and a mold release treatment apparatus. The term "mold" as used herein includes molds used for various processing methods (stamping and casting), and may be referred to as a stamper. It can also be used for printing (including nanoprinting).

  2. Description of the Related Art In general, optical elements such as display devices and camera lenses used in TVs and mobile phones are subjected to anti-reflection technology in order to reduce surface reflection and increase the amount of light transmission. For example, when light passes through an interface between media having different refractive indices as in the case where light is incident on the interface between air and glass, the amount of light transmission is reduced due to Fresnel reflection or the like, and the visibility is reduced. is there.

  In recent years, a method of forming on a substrate surface a fine uneven pattern in which the period of unevenness is controlled to the wavelength of visible light (λ = 380 nm to 780 nm) or less is attracting attention as an anti-reflection technique (Patent Documents 1 to 4) reference). The two-dimensional size of the convex part which comprises the uneven | corrugated pattern which expresses a reflection preventing function is 10 nm or more and less than 500 nm.

  This method utilizes the principle of so-called moth eye (Motheye) structure, and the refractive index for light incident on the substrate, the refractive index of the incident medium along the depth direction of the asperity, and the refractive index of the substrate By continuously changing up to the point, the reflection in the wavelength range where the reflection is desired to be prevented is suppressed.

  The moth-eye structure can exhibit an antireflection effect with small incident angle dependency over a wide wavelength range, and can be applied to many materials, and has advantages such as being able to form a concavo-convex pattern directly on a substrate. As a result, a low cost and high performance antireflective film (or antireflective surface) can be provided.

  As a method for producing a moth-eye structure, a method using an anodized porous alumina layer obtained by anodizing aluminum has attracted attention (Patent Documents 2 to 4).

  Here, the anodized porous alumina layer obtained by anodizing aluminum will be briefly described. Heretofore, a method for producing a porous structure utilizing anodization has attracted attention as a simple method capable of forming regularly arranged nano-order cylindrical pores (fine recesses). When the substrate is immersed in an acidic electrolytic solution such as sulfuric acid, oxalic acid or phosphoric acid or alkaline electrolytic solution and a voltage is applied with this as the anode, oxidation and dissolution proceed simultaneously on the surface of the substrate, and pores on the surface Can be formed. The cylindrical pores are oriented perpendicularly to the oxide film, and exhibit self-organizing regularity under certain conditions (such as voltage, type of electrolyte, temperature, etc.), so application to various functional materials Is expected.

  The porous alumina layer formed under the specific conditions takes an arrangement in which almost regular hexagonal cells are two-dimensionally and densely packed when viewed from the direction perpendicular to the film surface. Each cell has a pore at its center, and the arrangement of pores has a periodicity. The cells are formed as a result of local dissolution and growth of the film, and dissolution and growth of the film proceed simultaneously at the bottom of the pores called barrier layer. At this time, it is known that the cell size, that is, the distance between adjacent pores (center-to-center distance) corresponds to approximately twice the thickness of the barrier layer, and is approximately proportional to the voltage during anodic oxidation. In addition, although the diameter of the pore depends on the type, concentration, temperature, etc. of the electrolyte, it is usually 1/3 of the size of the cell (the length of the longest diagonal of the cell when viewed from the direction perpendicular to the film surface). It is known to be a degree. The pores of such porous alumina are highly ordered (having periodicity) arrangement under certain conditions, and, to some extent, irregularly ordered arrangement or irregular (less periodicity depending on conditions). Form an array.

  Patent Document 2 discloses a method of forming an antireflective film (antireflective surface) using a stamper having an anodized porous alumina film on the surface.

  Further, Patent Document 3 discloses a technique for forming a tapered concave portion in which the pore diameter changes continuously by repeating the anodic oxidation of aluminum and the hole diameter enlargement process.

  The applicant of the present application has disclosed, in Patent Document 4, a technique of forming an antireflective film using an alumina layer in which fine recesses have stepped side surfaces.

  Further, as described in Patent Documents 1, 2 and 4, in addition to the moth-eye structure (micro structure), an anti-reflection film (anti-reflection surface) is provided by providing a concavo-convex structure (macro structure) larger than the moth-eye structure. ) Can be provided with an antiglare (antiglare) function. The two-dimensional size of the convex part which comprises the unevenness | corrugation which exhibits an anti-glare function is one to 100 micrometer. The entire disclosures of Patent Documents 1, 2 and 4 are incorporated herein by reference.

  By using the anodized porous alumina film, it is possible to easily manufacture a mold for forming a moth-eye structure on the surface (hereinafter, referred to as “moth-eye mold”). In particular, as described in Patent Documents 2 and 4, when the surface of the anodic oxide film of aluminum is used as it is as a mold, the effect of reducing the manufacturing cost is large. The structure of the surface of the moth-eye mold capable of forming a moth-eye structure is referred to as "inverted moth-eye structure".

  As a method for producing an antireflective film using a moth-eye mold, a method using a photocurable resin is known. First, a photocurable resin is applied on a substrate. Subsequently, the concavo-convex structure of the surface of the moth-eye mold is filled with the photo-curable resin by pressing the concavo-convex surface of the moth-eye mold which has been subjected to the mold release treatment against the photocurable resin in vacuum. Subsequently, the photocurable resin in the concavo-convex structure is irradiated with ultraviolet light to cure the photocurable resin. Thereafter, by separating the moth-eye mold from the substrate, a cured product layer of the photocurable resin to which the uneven structure of the moth-eye mold has been transferred is formed on the surface of the substrate. A method for producing an antireflective film using a photocurable resin is described, for example, in Patent Document 4.

  The applicant has developed a method for efficiently manufacturing an antireflective film by a roll-to-roll method using a roll-shaped moth-eye mold (for example, Patent Document 5). Patent Document 5 discloses a mold release treatment method capable of applying a mold release agent to the surface of a mold having a porous alumina layer on the surface without unevenness. The entire disclosure of Patent Document 5 is incorporated herein by reference.

Japanese Patent Application Publication No. 2001-517319 Japanese Patent Publication No. 2003-531962 JP 2005-156695 A WO 2006/059686 International Publication No. 2011/111669

  However, when the present inventor performed a mold release treatment on the moth-eye mold, unevenness sometimes occurred on the surface of the moth-eye mold. Even in the case where the mold release agent is applied by the mold release treatment method of Patent Document 5, unevenness may still occur. According to the study of the inventor of the present invention, it was found that unevenness is generated in the step of drying the release agent after applying the release agent to the surface of the moth-eye mold. Details will be described later.

  This problem is not limited to the moth-eye mold, and is a common problem in the mold having a porous alumina layer having fine depressions on the submicron order on the surface.

  The main object of the present invention is to provide a method for releasing the surface of a mold having a porous alumina layer on the surface without unevenness.

  The mold release treatment method according to the embodiment of the present invention comprises (a) a mold release agent containing a fluorine compound having mold release property and a solvent, and a cylindrical or cylindrical mold having a porous alumina layer on the surface. (B) applying the mold release agent to the surface of the mold, and (c) drying the mold release agent applied in the step (b), the mold Generating a flow of air flowing in a direction parallel to the mold axis with respect to the surface of the mold, and drying comprising rotating the mold about the mold axis.

  In one embodiment, the rotational speed of the mold in the step (c) is 0.5 rpm or more and 10 rpm or less.

  In one embodiment, the flow rate of the air flow in the step (c) is 0.05 D (m / s) or more, where D (m) is the diameter of the mold in a cross section perpendicular to the mold axis. 52 D (m / s) or less.

  In one embodiment, the step of generating the gas flow in the step (c) includes the step of supplying a gas containing a solvent which dissolves the fluorine compound contained in the release agent.

  In one embodiment, the gas containing a solvent contains the same solvent as the solvent contained in the release agent.

  In one embodiment, the porous alumina layer has an inverted moth-eye structure on the surface, which has a plurality of recesses having a two-dimensional size of 50 nm or more and less than 500 nm when viewed in the normal direction of the surface.

  A method of manufacturing an antireflective film according to an embodiment of the present invention comprises the steps of preparing a mold on which a mold release treatment has been performed by any of the above-described mold release treatment methods, preparing a workpiece, and A step of curing the photocurable resin by irradiating the photocurable resin with light in a state in which the photocurable resin is applied to the surface of the workpiece, and photocuring cured from the mold And exfoliating the antireflective film formed of resin.

  A mold release processing apparatus according to an embodiment of the present invention includes a cylindrical cover having a first opening and a second opening, a cylindrical or cylindrical mold, the first opening and the second opening of the cover, and the like. Between and, substantially parallel to the axis of the cover, rotatably supporting structure rotatably supported about the axis of the mold.

  In one embodiment, the release processing apparatus further includes an air flow supply device which supplies an air flow substantially parallel to the axis of the cover from the first opening.

  In one embodiment, the air flow supply device has a filter provided in the first opening.

  In one embodiment, the rotary support structure includes a motor and a pedestal coupled to a drive shaft of the motor, at least a portion of the pedestal being between the first opening and the second opening. Located in

  According to the embodiment of the present invention, the surface of the mold having the porous alumina layer on the surface can be subjected to release treatment without unevenness.

(A)-(e) is a schematic diagram for demonstrating the mold release processing method and the mold release processing apparatus 50 by Embodiment 1 of this invention. (A) And (b) is a schematic diagram for demonstrating the mold release processing apparatus which performed the experiment example. It is a figure for demonstrating the consideration about the relationship between the flow velocity of the airflow 105, and the rotational speed of the type | mold 100 for moth-eye. (A)-(e) is typical sectional drawing for demonstrating the manufacturing method of the type | mold for moth-eye. It is a schematic cross section for demonstrating the method to manufacture an anti-reflective film by a roll-to-roll system. (A)-(c) is a schematic diagram for demonstrating the mold release processing apparatus 90 of the conventional mold release processing method and the comparative example used therein.

  When the present inventor performed release processing on a roll-like (for example, cylindrical or cylindrical) moth-eye mold, unevenness sometimes occurred on the surface of the moth-eye mold. According to the study of the present inventor, the unevenness is a step of drying the release agent applied to the surface of the moth-eye mold after the step of applying the release agent to the surface of the moth-eye mold ("release agent drying step It may have occurred in Details will be described below.

  A conventional mold release processing method will be described with reference to FIGS. 6 (a) to 6 (c). FIGS. 6A to 6C are schematic views for explaining a conventional mold release processing method and a mold release processing apparatus 90 of a comparative example used therefor. FIG. 6 (a) is a schematic view of the mold release processing apparatus 90 of the comparative example, and FIG. 6 (b) is a schematic cross sectional view of the mold release processing apparatus 90 of the comparative example. c) is a schematic view for explaining a method of examining the cause of unevenness generated in the conventional mold release treatment method.

  As shown to Fig.6 (a), the release processing apparatus 90 of a comparative example has the rectangular-tube-shaped cover 92 which has the 1st opening 92a and the 2nd opening 92b. The mold release processing apparatus 90 of the comparative example holds the cylindrical or cylindrical motheye mold 100 inside the cover 92 so that the long axis direction of the mold 100 is substantially parallel to the long axis direction of the cover 92. . The moth-eye mold 100 is, for example, erected and disposed so that the major axis direction is substantially parallel to the vertical direction. Typically, the long axis direction of the moth-eye mold 100 and the long axis direction of the cover 92 are arranged to substantially coincide with the vertical direction.

  In the release agent drying step, the air flow 105 ′ flowing in a direction parallel to the central axis of the moth-eye mold 100 with respect to the surface (that is, the side of the cylinder or cylinder) of the moth-eye mold 100 having the inverted moth-eye structure. Is supplied. In the example shown in FIG. 6A, an air flow 105 'flowing from the first opening 92a to the second opening 92b of the cover 92 is supplied. The air flow 105 ′ is fed into the cover 92 through, for example, the HEPA filter 94.

  FIG. 6B is a schematic cross-sectional view of the mold release processing apparatus 90 of the comparative example as viewed from the vertical direction. The air flow 105 ′ flows in the entire area between the cover 92 and the moth-eye mold 100. As shown in FIG. 6B, the cross section (bottom surface) of the moth-eye mold 100 is substantially circular, whereas the cross section (bottom surface) of the cover 92 is rectangular. The cross section of the cover 92 is typically the same shape as the first opening 92a and the second opening 92b. For example, the bottom of the moth-eye mold 100 is a circle with a diameter of 300 mm, and the cross section of the cover 92 is a square with a side of 600 mm. The moth-eye mold 100 is, for example, formed of an aluminum cylinder having a thickness of 15 mm, and the length in the long axis direction of the cylinder is 1600 mm.

  The step of applying the release agent uses, for example, the method and apparatus described in Patent Document 5. According to the method and / or apparatus described in Patent Document 5, the occurrence of uneven application of the release agent is prevented. That is, the release agent can be applied without unevenness.

  The release processing apparatus 90 of the comparative example further includes, for example, a motor 97 that rotates the moth-eye mold 100 about an axis. As described in Patent Document 5, the moth-eye mold 100 may be rotated in the step of applying the release agent. For example, when a mold release agent is applied by a spray coating method, if a spray nozzle moving in the long axis direction of the moth-eye mold 100 is used, the moth-eye mold 100 can be rotated about its axis. A release agent can be applied to the entire side of 100. On the other hand, in the conventional mold release treatment method, the moth-eye mold 100 is not rotated in the mold release agent drying step. In the release agent drying process, as described above, the air flow 105 ′ flows in the entire area between the cover 92 and the moth-eye mold 100. Therefore, even if the moth-eye mold 100 is not rotated, the air flow 105 ′ can extend over the entire side surface of the moth-eye mold 100.

  On the surface of the roll-like moth-eye mold 100 which has been subjected to the release treatment (including the step of applying a release agent and the release agent drying step) by the release treatment apparatus 90 of the comparative example, unevenness 101a and 101b are present. It happened. According to the study of the inventor, unevenness can be roughly divided into two main types depending on the place where it occurs. In the present specification, the unevenness 101 a refers to unevenness occurring mainly at the end in the long axis direction of the side surface of the moth-eye mold 100. The unevenness 101a often occurs at both ends of the side surface of the moth-eye mold 100, in particular, at the downstream end of the air flow 105 ', that is, near the lower end 100e of the moth-eye mold 100 in the example shown in FIG. The unevenness 101 b refers to unevenness occurring mainly in the central portion in the long axis direction, that is, in portions other than both end portions of the side surface of the moth-eye mold 100. The unevenness 101a is often streaky. As shown in FIG. 6A, the range 102a where the unevenness 101a is generated extends from the lower end 100e of the moth-eye mold 100 to the length L102 a in the long axis direction of the moth-eye mold 100. In the moth-eye mold 100 that has been subjected to release processing by the release processing apparatus 90 of the comparative example, the length L 102 a may be, for example, 200 mm or more and 300 mm or more.

  As described above, since the method and apparatus described in Patent Document 5 are used in the step of applying the release agent, the occurrence of uneven application of the release agent is suppressed. That is, it is considered that the unevenness 101a and 101b are not generated in the step of applying the release agent.

  In order to investigate the cause of the unevenness 101a and 101b, the inventor examined the flow of the air flow 105 'in the mold release treatment apparatus 90 of the comparative example using the smoke wire method. As shown in FIG. 6C, a thin wire (resistance wire) 110 of high resistance was placed in the cover 92. Liquid paraffin is applied to the resistance wire 110, and white smoke is generated by applying an electric current to visualize the flow of the air flow 105 '. For the smoke wire method, a smoke wire generator MS-405 manufactured by Ebara Corp. was used. As a result of investigation, it was found that the portion where the flow of the air flow 105 'is disturbed matches the portion where the unevenness 101a and 101b are generated. That is, in the surface (side surface) of the moth-eye mold 100, unevenness (unevenness) of the air flow 105 'may occur at the end in the long axis direction and at the center in the long axis direction. The present inventors considered that the unevenness (nonuniformity) of the air flow 105 'contributes to the generation of the unevenness 101a and 101b, and considered the present invention.

  The unevenness 101a and 101b of the moth-eye mold 100 can be visually observed immediately below the fluorescent lamp. In addition, when the moth-eye mold 100 has unevenness 101a and 101b, non-uniformity (unevenness) of the moth-eye structure is also formed on the surface of the antireflective film produced using the moth-eye mold 100.

  The above is a discussion of the inventor and does not limit the present invention.

  Hereinafter, a mold release processing method according to an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments exemplified below. Hereinafter, the case where a release treatment is performed on a roll-shaped moth-eye mold will be described as an example. The “roll-shaped moth-eye mold” includes a cylindrical moth-eye mold and a cylindrical moth-eye mold. In the following drawings, components having substantially the same functions are denoted by the same reference numerals, and the description thereof may be omitted.

(Embodiment 1)
A release processing method and a release processing apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. 1 (a) to 1 (e). 1 (a) to 1 (e) are schematic views for explaining a mold release processing method and a mold release processing apparatus 50 according to Embodiment 1 of the present invention. FIG. 1A is a schematic view of the mold release processing apparatus 50, and FIG. 1B is a schematic cross sectional view of the mold release processing apparatus 50. As shown in FIG. FIGS. 1C and 1D schematically show a moth-eye mold 100. FIG. FIG. 1E is a view schematically showing an example of a specific configuration of the pedestal 56. As shown in FIG.

  The mold release treatment method according to Embodiment 1 of the present invention prepares a mold release agent containing a fluorine compound having mold release property and a solvent, and a cylindrical or cylindrical mold 100 having a porous alumina layer 14 on the surface. And a step (B) of applying a release agent to the surface of the mold 100, and a step (C) of drying the release agent applied in the step (B). Step (C) includes the steps (C1) of generating an air flow 105 flowing in a direction parallel to the axis 100z of the mold 100, and the step (C2) of rotating the mold 100 about the axis 100z of the mold 100.

  According to the mold release treatment method according to the first embodiment of the present invention, as shown in an experimental example later, the surface of a mold having a porous alumina layer on the surface can be subjected to mold release treatment without unevenness. In particular, the occurrence of unevenness in the release agent drying process can be prevented.

  Hereinafter, details of the mold release processing method according to Embodiment 1 of the present invention will be described.

  First, a roll-shaped moth-eye mold 100 as shown in FIGS. 1C and 1D and a mold release agent (not shown) are prepared. The moth-eye mold 100 has a porous alumina layer 14 on the surface (i.e., the side of a cylinder or a cylinder). Use of the roll-shaped moth-eye mold 100 has an advantage that, for example, the anti-reflection film can be efficiently mass-produced by a roll-to-roll method.

  For example, as shown in FIG. 1D, the moth-eye mold 100 includes a roll-shaped support 12 (for example, a stainless steel tube) and an aluminum film 18 formed on the surface of the roll-shaped support 12. And a porous alumina layer 14 formed on the aluminum film 18. In FIG. 1D, for the sake of simplicity, only a part of the roll-like support 12, a part of the aluminum film 18, and a part of the porous alumina layer 14 are shown for the moth-eye mold 100. The porous alumina layer 14 has a plurality of fine recesses (pores) 14p. The two-dimensional size of the plurality of fine recesses 14p when viewed in the normal direction of the surface is 50 nm or more and less than 500 nm. The moth-eye mold 100 can be produced by repeating the anodic oxidation and etching of the aluminum film 18 formed on the roll-shaped support 12, as described in detail later. For the production of the moth-eye mold 100, for example, the methods described in Patent Documents 3 and 4 can be used.

  Next, the release agent is applied. As the release agent, a fluorine-based release agent containing a fluorine-based compound having releasability and a solvent is used. A well-known thing can be used widely as a fluorine-type mold release agent. For example, Florosurf manufactured by Fluoro Technology can be used. For example, Fluorosurf FG-5010Z130-0.1 can be used as Fluorosurf. Fluorosurf FG-5010Z130-0.1 contains a homopolymer of perfluorooctylethyl acrylate as a fluorine-based compound, and contains a diluent ZV (hydrofluoroether) as a solvent. For example, the concentration of homopolymers of perfluorooctylethyl acrylate of Fluorosurf FG-5010 Z130-0.1 is 0.1%. In addition to the above-described solvents, fluorosurf includes, for example, nonflammable fluorine-based solvents or petroleum-based solvents. As the nonflammable fluorine-based solvent, in addition to the hydrofluoroether, for example, perfluoropolyether, perfluoroalkane, hydrofluoropolyether, hydrofluorocarbon and the like can be mentioned. These nonflammable fluorine-based solvents are used singly or in combination of two or more. As a petroleum solvent, for example, n-heptane, acetone, or a solvent in which n-heptane and acetone are mixed is used.

  As the fluorine-based mold release agent, for example, OPTOOL DSX manufactured by Daikin Industries, Ltd. can be used. In addition, clear coat made by Mitsui DuPont Fluorochemicals can also be used. Moreover, as a solvent of a fluorine-type mold release agent, it is preferable to use a fluorine-type solvent. However, an aqueous solvent or a known organic solvent can be appropriately selected and used. The solvent is not limited to the one that dissolves the fluorine-based compound, but may be one that disperses the fluorine-based compound in the solvent.

  Fluorine-based release agents have an advantage that they have high releasability with respect to UV curable resins used in the production of antireflective films, as compared with release agents such as silicone-based release agents other than fluorine-based release agents. There is. In addition, fluorine-based release agents have the advantage of being highly resistant to ultraviolet light. In addition, the layer of the fluorine-based release agent is easily made thin.

  For example, the method and apparatus described in Patent Document 5 can be used to apply a release agent, as described below. Uneven application of the release agent can be prevented by using the method and / or apparatus described in Patent Document 5. In addition, as described in Patent Document 5, a washing step, a step of drying the surface, a step of baking the surface, and the like may be further performed before the step of applying the release agent.

  First, a solvent is applied to the surface of the moth-eye mold 100. The solvent to be applied here is typically a solvent contained in the mold release agent, but is not limited thereto and may be a solvent capable of dissolving the fluorine compound having mold release property contained in the mold release agent. Just do it. The solvent is applied by spray coating, for example, using a spray nozzle. Subsequently, a release agent is applied to the surface of the moth-eye mold 100. The release agent is applied by spray coating, for example, using a spray nozzle.

Subsequently, the release agent applied to the surface of the moth-eye mold 100 is dried. In the release agent drying step, the air flow 105 is generated to flow in a direction parallel to the axis 100z of the moth-eye mold 100 with respect to the surface of the moth-eye mold 100, and the moth-eye mold 100 is rotated about the axis 100z. Let The axis 100z is a central axis of the moth-eye mold 100. The air flow 105 may be, for example, a flow of air, or may be another gas (eg, an inert gas (eg, nitrogen gas, Ar gas, etc.), carbon dioxide gas (CO ₂ ), oxygen gas, etc.).

  According to the release agent drying process of the release treatment method according to the embodiment of the present invention, it is possible to suppress the occurrence of unevenness 101 a and 101 b which may occur in the conventional release treatment method. According to the release agent drying process of the mold release treatment method according to the embodiment of the present invention, the uniformity of the air flow 105 flowing on the surface of the moth-eye mold 100 can be determined by combining both the end and the central portion of the side surface of the moth-eye mold 100 Can be improved.

  The rotational speed of the moth-eye mold 100 is, for example, preferably 0.5 rpm or more and 10 rpm or less, and more preferably 1 rpm or more and 10 rpm or less, as described later with reference to experimental examples. The flow velocity of the air flow 105 is preferably, for example, not less than 0.05 × 100 d (m / s) and not more than 0.52 × 100 d (m / s). Here, the diameter of the bottom of the moth-eye mold 100 is 100 d (m). The bottom of the moth-eye mold 100 is a cross section perpendicular to the axis 100 z of the moth-eye mold 100. The above-mentioned range of the flow velocity of the air flow 105 corresponds to a range of 1 rpm or more and 10 rpm or less in terms of rotational speed. Because rpm is a unit representing the number of revolutions per minute, 1 rpm corresponds to (π × 100 d) / 60 (m / s). The relationship between the flow velocity of the air flow 105 and the rotational speed of the moth-eye mold 100 will be described later with reference to experimental examples.

  Next, the mold release processing apparatus 50 according to the present embodiment will be described. According to the mold release processing apparatus 50, the mold release processing method according to the present embodiment can be performed. However, the mold release processing apparatus according to the embodiment of the present invention is not limited to those exemplified below.

  As shown in FIG. 1A, the mold release processing apparatus 50 includes a cylindrical cover 52 having a first opening 52a and a second opening 52b, and a rotary support structure 58. The rotary support structure 58 is a cylindrical or cylindrical mold 100 between the first opening 52 a and the second opening 52 b of the cover 52 substantially parallel to the axis 52 z of the cover 52 and the axis 100 z of the mold 100. Supports rotatably around.

  According to the mold release processing apparatus 50, the mold surface having the porous alumina layer on the surface can be subjected to mold release processing without unevenness. In particular, the occurrence of unevenness in the release agent drying process can be prevented.

  FIG. 1 (b) is a schematic cross-sectional view of the mold release processing apparatus 50. The moth-eye mold 100 and the cover 52 are disposed, for example, such that the major axis direction is substantially parallel to the vertical direction. That is, the axis 100 z direction of the moth-eye mold 100 and the axis 52 z direction of the cover 52 may be arranged to substantially coincide with the vertical direction. The moth-eye mold 100 may be suspended from above by, for example, a suspending member 69 (see FIG. 1A) attached to the moth-eye mold 100. The cover 52 may be provided, for example, inside a prismatic or rectangular cylindrical application chamber 62 (see FIG. 1B).

  Since the mold release processing apparatus 90 of the comparative example has the rectangular cylindrical cover 92, the distance from each point on the surface of the moth-eye mold 100 to the cover 92 is not uniform. It is believed that this may contribute to the non-uniformity of the air flow 105 '.

  On the other hand, in the mold release processing apparatus 50 according to the embodiment of the present invention, as shown in FIG. 1B, the cross section of the cover 52 and the cross section of the moth-eye mold 100 are both substantially circular. Typically, the shapes of the first opening 52a and the second opening 52b of the cover 52 are circles having the same diameter as each other. Typically, when viewed from the vertical direction, the cover 52 and the moth-eye mold 100 are installed so that the centers thereof coincide with each other. At this time, the distance to the cover 52 is equal to each point on the surface of the moth-eye mold 100. In the mold release processing apparatus 50 according to the embodiment of the present invention, the flow velocity of the air flow 105 may be uniform for each point on the surface of the moth-eye mold 100. This effect can be obtained at both the end in the long axis direction and the central portion in the long axis direction of the surface (side surface) of the moth-eye mold 100. Therefore, for example, the occurrence of unevenness 101a and 101b (see FIG. 6A) that can occur in the mold release processing apparatus 90 of the comparative example is suppressed.

  For example, the cross section of the cover 52 is a circle with a diameter of 500 mm. The bottom surface of the moth-eye mold 100 is a circle with a diameter of 300 mm, and the moth-eye mold 100 is formed of, for example, an aluminum cylinder with a thickness of 15 mm. The length of the cylinder in the long axis direction is 1600 mm. The cover 52 is formed of, for example, a metal (for example, stainless steel, an anodized Al plate or the like) or a resin (for example, an acrylic resin, a polycarbonate resin, a BS-based resin or the like). The half cylinders formed of different materials may be combined to form the cover 52. For example, here, a half cylinder made of stainless steel and acrylic resin is combined to form the cover 52. When at least a part of the cover 52 is formed of a transparent material such as an acrylic resin, it is easy to observe the air flow 105 in the cover 52 using, for example, a smoke wire method.

  The rotation support structure 58 has, for example, a motor 57 and a pedestal 56 coupled to a drive shaft 57 d of the motor 57. At least a portion of the pedestal 56 is located between the first opening 52a and the second opening 52b. The rotary support structure 58 may further include a coupling member (not shown) that couples the pedestal 56 and the drive shaft 57 d of the motor 57.

  The motor 57 rotates the moth-eye mold 100 about the axis 100 z of the moth-eye mold 100. By the motor 57, the moth-eye mold 100 can be rotated about the shaft 100z in the release agent drying process. Thereby, as an experimental example is shown later, generation | occurrence | production of the unevenness | corrugation 101a, 101b (refer FIG. 6 (a)) which may generate | occur | produce in the mold release processing apparatus 90 of a comparative example is suppressed. One of the causes of the unevenness is considered to be the uneven speed at which the release agent dries due to the inhomogeneity of the air flow 105. When the moth-eye mold 100 is rotated, the air flow 105 can be made uniform, and it can be considered that the occurrence of unevenness can be suppressed. The preferable range of the flow velocity of the air flow 105 and the rotational speed of the moth-eye mold 100 will be described later with reference to experimental examples. Of course, the moth-eye mold 100 may be rotated by the motor 57 also in the step of applying the release agent.

  When at least a part of the pedestal 56 is located between the first opening 52a and the second opening 52b of the cover 52, between the second opening 52b of the cover 52 and the lower end 100e of the moth-eye mold 100 in the vertical direction. Distance L can be increased. Here, in the vertical direction, the second opening 52 b of the cover 52 is below the lower end 100 e of the moth-eye mold 100. Moreover, in the mold release treatment process, the moth-eye mold 100 can be stably supported.

  In the conventional mold release processing method using the mold release processing apparatus 90 of the comparative example, unevenness 101a occurs around the end (particularly the lower end) in the long axis direction of the surface (side surface) of the moth-eye mold 100 There was a case (see FIG. 6 (a)). In the mold release processing apparatus 90 of the comparative example, since the second opening 52b of the cover 52 is above or below the lower end 100e of the moth-eye mold 100, the distance L is small. It is considered that the air flow 105 'is disturbed near the lower end 100e of the side surface of the mold 100, and the unevenness 101a is generated. In the mold release processing apparatus 50 according to the embodiment of the present invention, since the distance L is large, the turbulence of the air flow 105 around the lower end 100e of the side surface of the moth-eye mold 100 is suppressed, and the generation of the unevenness 101a is suppressed. The distance L is, for example, preferably 200 mm or more, and more preferably 300 mm or more.

  Even if the occurrence of the unevenness 101a is not completely suppressed, when the range 102a (see FIG. 6A) in which the unevenness 101a is occurring is small, there are cases where it can be used without practical problems. When a film (for example, an antireflective film) is produced using a moth-eye mold, a portion of the produced film other than the portion corresponding to the effective area of the mold may be treated as an excess space. A range in which the length in the long axis direction from the lower end 100e of the moth-eye mold 100 is, for example, within 20 mm to 50 mm may not be included in the effective area of the mold. Therefore, in the moth-eye mold 100, if the length L102a (see FIG. 6A) in the long axis direction from the lower end 100e of the range 102a where the unevenness 101a is occurring is, for example, 20 mm or less, there is no practical problem. It can be used.

  The pedestal 56 has, for example, a cylindrical shape, and is provided such that the axial direction of the pedestal 56 substantially matches the axis 100 z direction of the mold 100. For example, the cross-sectional area of the pedestal 56 in a plane perpendicular to the axis 100 z of the mold 100 substantially matches the cross-sectional area of the mold 100 in the plane perpendicular to the axis 100 z of the mold 100.

  The pedestal 56 may have a structure as shown in FIG. 1 (e), for example. FIG. 1E is a view schematically showing an example of a specific configuration of the pedestal 56. As shown in FIG.

  As illustrated in FIG. 1E, the pedestal 56 is a base plate (mount plate) 56a for mounting and fixing the mold 100, a liquid receiving plate 56b for receiving liquid dropped from the surface of the mold 100, and these plates And a connecting member 56z that connects the two together. The cross-sectional shapes of the base plate 56 a and the liquid receiving plate 56 b as viewed in the vertical direction are typically substantially circular.

  The diameter of the cross section of the base plate 56 a as viewed in the vertical direction is substantially the same as the diameter of the cross section as viewed in the long axis direction of the moth-eye mold 100. The center of the cross section of the base plate 56 a as viewed in the vertical direction is, for example, on the long axis of the moth-eye mold 100.

  The diameter of the cross section of the liquid receiving plate 56b when viewed from the vertical direction is larger than the diameter of the cross section when viewed from the long axis direction of the moth-eye mold 100. The center of the cross section of the liquid receiving plate 56b as viewed in the vertical direction is, for example, on the long axis of the moth-eye mold 100. The liquid receiving plate 56b has tapered side surfaces. The diameter of the upper surface (surface on the side of the base plate 56a) of the liquid receiving plate 56b is smaller than the diameter of the lower surface (the surface on the opposite side to the base plate 56a) of the liquid receiving plate 56b. The diameter of the upper surface of the liquid receiving plate 56b is, for example, substantially the same as the diameter of the cross section of the moth-eye mold 100 as viewed in the long axis direction. The diameter of the lower surface of the liquid receiving plate 56b is, for example, larger than the diameter of the cross section of the moth-eye mold 100 as viewed in the long axis direction.

  When the center and diameter of the cross section as viewed from the vertical direction of the base plate 56a substantially agree with the center and diameter of the cross section as viewed from the long axis direction of the moth-eye mold 100, it adheres to the surface of the moth-eye mold 100 The liquid can flow smoothly. Furthermore, the disturbance of the air flow 105 in the vicinity of the lower end 100 e of the moth-eye mold 100 can be suppressed.

  When the side surface of the liquid receiving plate 56 b is tapered, the liquid dropped into the liquid reservoir 59 provided below the moth-eye mold 100 can be prevented from splashing and adhering to the moth-eye mold 100.

  If the diameter of the lower surface (surface opposite to the base plate 56a) of the liquid receiving plate 56b is larger than the diameter of the cross section as viewed from the long axis direction of the moth-eye mold 100, the cover from below the moth-eye mold 100 It is possible to reduce the gas and dust that may enter into the space 52.

  When viewed from the vertical direction, all of the connection members 56z overlap the moth-eye mold 100. The cross-sectional area of the connection member 56z when viewed from the vertical direction is smaller than the cross-sectional area when viewed from the long axis direction of the moth-eye mold 100. Thus, a space is formed between the base plate 56a and the liquid receiving plate 56b. In the space thus formed, the vaporized solvent and / or the release agent can be retained. The release agent applied to the surface of the moth-eye mold 100 can be prevented from drying from the lower end 100 e side of the moth-eye mold 100. By making the release rate of the release agent uniform, it is possible to suppress the occurrence of unevenness.

  The release processing apparatus 50 further includes, for example, an air flow supply device 55 that supplies an air flow 105 substantially parallel to the axis 52 z of the cover 52 from the first opening 52 a. The air flow 105 supplied by the air flow supply device 55 flows from the first opening 52a toward the second opening 52b.

  The air flow supply device 55 has, for example, a filter 53 provided in the first opening 52a. The air flow supply device may further include, for example, a HEPA filter 54 provided outside the first opening 52 a of the filter 53.

An air flow is introduced into the air flow supply device 55 from, for example, a blower (not shown). The blower may be provided separately from the mold release processing apparatus 50. The air flow introduced from the blower unit is homogenized by passing through the filter 53. An air flow 105 flowing in a direction parallel to the axis 100 z of the mold 100 is supplied into the cover 52. The filter 53 is, for example, a punching plate (punching metal). The thickness of the punching plate is, for example, 0.5 mm to 1.5 mm. The opening diameter of the punching plate is, for example, 1.0 mm to 8.0 mm. The pitch of the openings of the punching plate is, for example, 1 mm to 20 mm. The aperture ratio of the punching plate is, for example, 20% to 50%. Here, for example, a punching plate having a round hole 60 ° staggered pattern (a pattern in which circular openings are arranged on lattice points of an equilateral triangular lattice) is used. The aperture ratio of this punching pattern is obtained by 90.6 × D ² / P ² (%) (P: inter-hole pitch, D: hole diameter).

  Not limited to the above-described example, the blower may be provided as part of the air flow supply device 55. The airflow supply device 55 may further include a blower (not shown), which is, for example, a fan, a blower, or a fan.

  Both the step of applying the release agent and the release agent drying step can be performed using the release processing device 50. By using a common apparatus, it is not necessary to move the moth-eye mold between both steps, and the manufacturing yield can be improved. International Publication No. WO 2012/133390 by the applicant discloses a mold release treatment method for improving the sustainability of mold release property by performing the step of applying a mold release agent twice or more. Every time the step of applying the release agent is performed, the step of drying the release agent is required. Therefore, also in the mold release treatment method described in WO 2012/133390, manufacturing yield is improved by performing both the process of applying the mold release agent and the process of drying the mold release agent using a common apparatus. be able to. The entire disclosure of WO 2012/133390 is incorporated herein by reference.

Second Embodiment
A mold release treatment method and a mold release treatment apparatus according to Embodiment 2 of the present invention will be described. The following description will be made focusing on differences between the mold release processing method and the mold release processing apparatus in the present embodiment from the mold release processing method and the mold release processing apparatus in the first embodiment.

  In the mold release treatment method according to Embodiment 2, the step of generating the air flow 105 includes the step of supplying a gas including a solvent that dissolves the fluorine compound contained in the mold release agent. The vaporized solvent is, for example, the same solvent as the solvent contained in the release agent. The vaporized solvent may be a solvent different from the solvent contained in the release agent. The vaporized solvent may be, for example, a solvent that can dissolve the fluorine-based compound having releasability contained in the release agent.

  According to the mold release treatment method according to the second embodiment of the present invention, as shown in an experimental example later, the surface of a mold having a porous alumina layer on the surface can be subjected to mold release treatment without unevenness. In particular, the occurrence of unevenness in the release agent drying process can be prevented.

  The mold release treatment method according to Embodiment 2 of the present invention may have the effect of reducing the drying speed of the mold release agent because the gas stream 105 contains the vaporized solvent. As an experimental example will be shown later, the occurrence of unevenness can be prevented more effectively than the mold release treatment method of the first embodiment.

  The air flow supply device 55 of the mold release processing apparatus that performs the mold release processing method of the present embodiment further includes, for example, a container (for example, a flask). The mouth of the container is connected to a steam inlet provided between the HEPA filter 54 and the filter 53. When the solvent is put in the container, the solvent is spontaneously vaporized, and an air flow 105 containing the vaporized solvent can be supplied. Alternatively, the vaporized solvent can be contained in the gas by placing a solvent in a flask and introducing a gas (for example, nitrogen gas or air) into the solvent in the flask and bubbling. An air stream 105 containing a vaporized solvent can be provided. The steam inlet connected to the container may be provided outside the HEPA filter 54 and the filter 53.

  The mold release processing apparatus according to Embodiment 2 of the present invention is not limited to the above example. For example, the evaporation pan may be placed outside the filter 53. The solvent may be placed in an evaporation dish for natural evaporation, and air containing the vaporized solvent may be used to generate the air flow 105. The container for containing the solvent is not limited to the evaporation dish, and may be any shape that can hold the liquid inside. The cross section of the container may, for example, be U-shaped or V-shaped. The container for containing the solvent may be provided, for example, in contact with the inside of the cylindrical cover 52. For example, the container for containing the solvent may be provided integrally with the mold release processing apparatus 50. For example, when the air flow 105 flows from the first opening 52a toward the second opening 52b, the container for containing the solvent is preferably provided near the first opening 52a inside the cover 52. Alternatively, the vaporized solvent may be jetted from an air nozzle (not shown) to be contained in the gas. At this time, in order not to significantly change the flow of the air flow, it is preferable to spray the solvent into small particles in the form of mist. Furthermore, through the filter 53 thereafter, the uniformed air flow 105 can be obtained.

(Experimental example)
An experimental example is shown below. FIGS. 2 (a) and 2 (b) are schematic views for explaining the mold release processing apparatus in which the experimental example was performed. As an experimental example, release processing was performed by the release processing method of Embodiment 1 or Embodiment 2 described above. Here, the mold release treatment was performed while changing the flow velocity of the air flow 105, the rotational speed of the moth-eye mold 100, and the presence or absence of the solvent in the air flow 105.

  The moth-eye mold used here was produced by repeating the anodic oxidation and etching of the aluminum base using the methods described in, for example, Patent Documents 3 and 4 above. As an aluminum substrate, a substrate produced by forming an aluminum film 18 with a thickness of 1 μm on a surface of a roll-like support (a tube made of stainless steel) by sputtering was used. The diameter of the bottom of the aluminum substrate is 300 mm, the length in the long axis direction is 1600 mm, and the thickness is 15 mm.

  A porous alumina layer was formed on the surface of the aluminum film 18 by first performing anodic oxidation using this base material. The anodic oxidation step was carried out for 60 seconds by applying 80 V using an aqueous solution of oxalic acid (concentration 0.05 mol / L, solution temperature 3 ° C.). A Pt plate was used as an electrode. The distance between the electrode and the substrate was 150 mm.

  Next, the porous alumina layer was completely removed by etching. The etching step was performed for 90 minutes using a phosphoric acid aqueous solution (concentration 8 mol / L, solution temperature 30 ° C.).

  Next, the anodic oxidation step and the etching step were alternately performed five times (five times for anodic oxidation and four times for etching). The anodizing step was carried out for 60 seconds by applying 80 V using an oxalic acid aqueous solution (concentration 0.05 mol / L, solution temperature 3 ° C.) as described above. The etching step was performed for 20 minutes using a phosphoric acid aqueous solution (concentration 8 mol / L, solution temperature 30 ° C.).

  In the moth-eye mold thus obtained, a plurality of pores with a depth of about 400 nm and a pore spacing of about 180 nm were formed.

  Next, as shown below, mold release processing of the moth-eye mold was performed by the mold release processing method of Embodiment 1 or Embodiment 2 described above. At this time, in the release agent drying step, as shown in Table 1 below, the mold release treatment was performed while changing the flow velocity of the air flow 105, the rotational speed of the moth-eye mold 100, and the presence or absence of the solvent in the air flow 105. Here, the diameter of the bottom surface of the cover 52 used is 500 mm, and the length in the vertical direction is 2000 mm. A distance L (see FIG. 1A) between the second opening 52b of the cover 52 and the lower end 100e of the moth-eye mold 100 in the vertical direction was 200 mm.

  The flow velocity of the air flow 105 was measured as follows. As schematically shown in FIGS. 2 (a) and 2 (b), two types of current meter 120 (manufactured by Beatrix Co., Ltd., ultra-low-velocity sensors BS-03 and BS) are respectively provided at four places inside the cover 52. Provided -05). By installing two types of flow velocity meters having different measurable flow velocity ranges, it is possible to measure a wider range of flow velocity. FIG. 2B is a schematic cross-sectional view of the mold release processing apparatus 50 as viewed from the vertical direction. As shown in FIG. 2 (b), two flow velocity meters 120 were installed at four points at equal intervals in the circumferential direction. The positions in the vertical direction of the four places where the flow meter 120 is installed are the same as one another. The current meter 120 was installed approximately at the center of the cover 52 in the vertical direction. The flow velocity of the air flow 105 was measured three times each by the flow velocity meter 120 at four points, and was taken as the average value (that is, the average value of a total of 12 data).

  The smoke wire method was used to observe the flow of the air flow 105 in the release agent drying process, and to check whether the air flow 105 had nonuniformity. As shown in FIG. 2 (b), a substantially semicircular high resistance thin wire (resistance wire) 110 is provided in the cover 52. For the smoke wire method, a smoke wire generator MS-405 manufactured by Ebara Corp. was used. Liquid paraffin is applied to the resistance wire 110, white smoke is generated by applying an electric current, the flow of the air flow 105 is visualized, and whether or not the flow of the air flow 105 has nonuniformity (disturbance) is visually examined The

  With respect to the surface of the moth-eye mold 100 after the release treatment, the presence or absence of unevenness was visually inspected immediately below the fluorescent lamp.

  The results are shown in Table 1 below.

  In Table 1, "(circle)" shows that the unevenness | corrugation of the surface of the type | mold 100 for moth-eye was suppressed to such an extent that it can be used practically without a problem. Specifically, it indicates that the length (L102a in FIG. 6A) in the long axis direction from the lower end 100e in the range where unevenness occurs is 20 mm or less. “◎” indicates that unevenness on the surface of the moth-eye mold 100 was not visually recognized. In both “x” and “Δ”, unevenness is visually recognized on the surface of the moth-eye mold 100, and the length in the long axis direction from the lower end 100e (in FIG. 6A) It shows that L102a) was over 20 mm. "(Triangle | delta)" shows that the unevenness | corrugation of the surface of the type | mold of moth-eye was relieve | moderated rather than "x".

  By visualizing the flow of the air flow 105, it was confirmed that the unevenness of the surface of the moth-eye mold 100 occurred corresponding to the disturbance of the air flow 105. In the case of “◎”, the flow of the air flow 105 was not disturbed. In the case of “o”, the flow of the air flow 105 was disturbed, but the disturbance is observed only within the range of 20 mm or less in the length (L 102 a in FIG. 6A) in the long axis direction from the lower end 100 e. It had happened. In the case of “×” and “Δ”, the flow of the air flow 105 is disturbed, and the length in the major axis direction from the lower end 100 e (L 102 a in FIG. It was super.

  As seen from Table 1, the rotational speed of the moth-eye mold 100 is, for example, preferably 0.5 rpm or more and 10 rpm or less, and more preferably 1 rpm or more and 10 rpm or less. In Table 1, in the column of "rotational speed", the rotational speed (rpm) and a value obtained by converting it into the speed (m / s) are written together. As described above, since rpm is a unit that represents the number of revolutions per minute, assuming that the bottom diameter of the moth-eye mold 100 is 100 d (m), 1 rpm is equivalent to (π x 100 d) / 60 (m / s) Do. In the experimental example in which the rotation speed is 30 (rpm), it is considered that the air flow 105 is disturbed due to the high rotation speed.

  As can be seen from Table 1, the flow velocity of the air flow 105 is preferably, for example, not less than 0.016 (m / s) and not more than 0.157 (m / s). When the gas stream 105 does not contain the vaporized solvent, the flow velocity of the gas stream 105 is more preferably, for example, 0.016 (m / s) or more and 0.126 (m / s) or less. When the flow velocity of the air flow 105 is 0.157 (m / s), by making the air flow 105 contain a vaporized solvent, homogenization of the air flow 105 and homogenization of the surface of the moth-eye mold 100 are made more effective. I understand that it was done. In the experimental example in which the flow velocity of the air flow 105 is 0.01 (m / s), it is considered that the flow velocity is low and the air flow 105 is not uniform. In the experimental example in which the flow velocity of the air flow 105 is 0.471 (m / s), it is considered that the air flow 105 is disturbed due to the high flow velocity.

  The rotational speed (m / s) of the moth-eye mold 100 in the same range as the preferable range of the flow velocity of the air flow 105 described above, 0.016 (m / s) or more and 0.157 (m / s) or less, It is 1 rpm or more and 10 rpm or less in terms of rpm). This is, assuming that the diameter of the bottom of the moth-eye mold 100 is 100 d (m), (π × 100 d) / 60 (m / s) or more and (π × 100 d) / 6 (m / s) or less (that is, 0. It corresponds to 05 × 100 d (m / s) or more and 0.52 × 100 d (m / s) or more. That is, it has been found that the flow velocity of the air flow 105 and the rotational speed of the moth-eye mold 100 are preferably of the same order of magnitude. For example, the flow velocity of the air flow 105 and the rotational speed of the moth-eye mold 100 may be the same size. The inventor considered the reason as follows.

Consider a total velocity v _t (m / s) which is a combination of the flow velocity v _f (m / s) of the air flow 105 and the rotational velocity v _r (m / s) of the moth-eye mold 100. The rotational speed v _r of the flow velocity v _f and motheye mold 100 of the air flow 105, and orientation are perpendicular to each other. Therefore, the relationship of v _t ² = v _f ² + v _r ² holds. Speed at which the release agent is dried is believed v depends on the _t (for example proportional to v _t).

To consider the relationship between the rotational speed v _r of the flow velocity v _f and motheye mold 100 of the airflow 105, consider the case of two extreme cases. (I) Consider the cases represented by the following formulas (1-1) to (1-3) and (ii) the cases represented by the following formulas (2-1) to (2-3).

The coefficient of v _f in (ii) was determined so that the value of v _t would be the same between (i) and (ii) (equation (2-1)). In these cases, the absolute value of the amount of change in the total velocity v _t when the change in the flow velocity v _f occurs is compared.

It is assumed that the flow velocity v _f changes to av _f . a is a real number greater than zero. In the case of 0 <a <1, it represents that the flow velocity v _f decreased, and in the case of a> 1, it represents that the flow velocity v _f increased. For a = 1, there is no change in the flow velocity v _f. Absolute value of the change amount of the total velocity v _t in each case, by the following equation in the case of (i) (3), in the case of (ii) by the following formula (4) are represented respectively.

A graph plotting the difference between A and B is shown in FIG. As can be seen from FIG. 3, B is always larger than A (Al is always smaller than B). That is, in the case of (i), the change amount of the total velocity v _t is always smaller than in the case of (ii). Therefore, in the case of (i), the amount of change in the total velocity v _t is smaller when the flow velocity v _f changes than in the case of (ii), and the drying rate of the release agent is uniformly maintained. It is considered to be easy to catch.

  As described above, the reason why it is preferable that the flow velocity of the air flow 105 and the rotational speed of the moth-eye mold 100 be of the same order of magnitude may be considered. However, the above is the present inventor's consideration, and does not limit the present invention.

  Next, with reference to FIG. 4, the manufacturing process of the moth-eye mold will be described. FIGS. 4A to 4E are schematic cross-sectional views for explaining a method of manufacturing a moth-eye mold. In the following, the case of producing a flat moth-eye mold by anodizing and etching using the aluminum base 10 having the substrate 16 and the aluminum film 18 deposited on the substrate 16 will be exemplified. .

  First, as shown in FIG. 4A, the aluminum base 10 is prepared. The aluminum substrate 10 has a substrate 16 and an aluminum film 18 deposited on the substrate 16.

  Next, as shown in FIG. 4B, the surface of the substrate 10 (the surface 18s of the aluminum film 18) is anodized to form a porous alumina layer 14 having a plurality of pores 14p (fine recesses). Do. The porous alumina layer 14 has a porous layer having pores 14 p and a barrier layer. The porous alumina layer 14 is formed, for example, by anodizing the surface 18s in an acidic electrolyte solution. The electrolytic solution used in the step of forming the porous alumina layer 14 is, for example, an aqueous solution containing an acid selected from the group consisting of oxalic acid, tartaric acid, phosphoric acid, chromic acid, citric acid and malic acid. For example, the porous alumina layer 14 is formed by anodizing the surface 18s of the aluminum film 18 for 30 seconds at an applied voltage of 80 V using a boric acid aqueous solution (concentration 0.06 wt%, solution temperature 5 ° C.). By adjusting the anodic oxidation conditions (for example, the type of electrolytic solution, applied voltage), it is possible to adjust the pore spacing, the depth of the pores, the shape of the pores, and the like. The thickness of the porous alumina layer may be appropriately changed. The aluminum film 18 may be completely anodized.

  Next, as shown in FIG. 4C, the pore diameter of the pores 14p is enlarged by contacting the porous alumina layer 14 with an etchant of alumina and etching it by a predetermined amount. Here, by adopting wet etching, the pore walls and the barrier layer can be etched almost isotropically. The amount of etching (that is, the size and depth of the pores 14p) can be controlled by adjusting the type and concentration of the etchant and the etching time. As the etching solution, for example, an aqueous solution of 10% by mass of phosphoric acid, an organic acid such as formic acid, acetic acid, citric acid or the like, or a mixed aqueous solution of chromic phosphoric acid can be used. For example, the pores 14p are enlarged by performing etching for 25 minutes using phosphoric acid (concentration 1 mol / L, liquid temperature 30 ° C.).

  Next, as shown in FIG. 4D, the aluminum film 18 is partially anodized again to grow the pores 14p in the depth direction and to thicken the porous alumina layer 14. Here, since the growth of the pore 14p starts from the bottom of the already formed pore 14p, the side surface of the pore 14p is stepped.

  After this, if necessary, the pore diameter of the pores 14p is further expanded by further etching the porous alumina layer 14 by contacting it with an etchant of alumina. As the etching solution, it is preferable to use the above-described etching solution, and in reality, the same etching solution may be used.

  Thus, by repeating the anodic oxidation step and the etching step described above, as shown in FIG. 4E, a moth-eye mold 100 having a porous alumina layer 14 having a desired uneven shape can be obtained. Thereafter, the moth-eye mold 100 is used for manufacturing an antireflective film after being subjected to a release treatment by, for example, the release treatment method of the first embodiment or the second embodiment.

  In the above, the case of producing a flat moth-eye mold using the aluminum base 10 having the substrate 16 and the aluminum film 18 deposited on the substrate 16 has been described as an example, but a roll The moth-eye mold is anodized and etched using an aluminum base having, for example, a roll-like support (for example, a stainless steel tube) and an aluminum film formed on the roll-like support. , Can be made. Further, in the roll-shaped moth-eye mold, an aluminum film is formed on the polymer film using a flexible polymer film as the substrate 16, and the surface of the aluminum film is anodized to form a porous alumina layer. It can also be produced by fixing a polymer film on the outer peripheral surface of a roll-like support after formation.

  Next, with reference to FIG. 5, a method of manufacturing an antireflective film according to an embodiment of the present invention will be described. FIG. 5 is a schematic cross-sectional view for explaining a method of manufacturing an antireflective film by a roll-to-roll method.

  A method of manufacturing an antireflective film according to an embodiment of the present invention comprises the steps of preparing a mold on which a mold release treatment has been performed by any of the above-described mold release treatment methods, preparing a workpiece, and A step of curing the photocurable resin by irradiating the photocurable resin with light in a state in which the photocurable resin is applied to the surface of the workpiece, and photocuring cured from the mold And exfoliating the antireflective film formed of resin.

  When a roll-shaped film is used as a workpiece, the antireflective film can be manufactured by a roll-to-roll method. The film preferably has a base film and a hard coat layer formed on the base film, and the antireflective film is preferably formed on the hard coat layer. As a base film, for example, a TAC (triacetyl cellulose) film can be suitably used. As the hard coat layer, for example, an acrylic hard coat material can be used.

  First, a roll-shaped moth-eye mold 100 is prepared. For example, a moth-eye mold 100 subjected to release processing by the release processing method of Embodiment 1 or Embodiment 2 is prepared.

  Next, as shown in FIG. 5, the ultraviolet curable resin 32 ′ is irradiated with ultraviolet light (UV) while the workpiece 42 having the ultraviolet curable resin 32 ′ applied to the surface is pressed against the moth-eye mold 100. Thus, the UV curable resin 32 'is cured. For example, an acrylic resin can be used as the ultraviolet curable resin 32 '. The workpiece 42 is, for example, a TAC (triacetyl cellulose) film. The workpiece 42 is unrolled from an unillustrated unrolling roller, and then an ultraviolet curing resin 32 'is applied to the surface by, for example, a slit coater or the like. The workpiece 42 is supported by support rollers 46 and 48, as shown in FIG. The support rollers 46 and 48 have a rotation mechanism and transport the workpiece 42. Further, the roll-shaped moth-eye mold 100 is rotated at a rotational speed corresponding to the transport speed of the workpiece 42 in the direction indicated by the arrow in FIG. 5.

  Thereafter, the moth-eye mold 100 is separated (peeled off) from the workpiece 42, whereby the hardened material layer 32 to which the concavo-convex structure (inverted moth-eye structure) of the moth-eye mold 100 is transferred is transferred to the surface of the workpiece 42. It is formed. The workpiece 42 having the hardened material layer 32 formed on the surface is taken up by a take-up roller (not shown).

  In addition, in order to form an anti-reflection film excellent in anti-reflection performance, the pore 14p of the moth-eye mold 100 has a two-dimensional size of 10 nm or more and less than 500 nm when viewed from the normal direction of the surface. Is preferable (the above-mentioned patent documents 1, 2 and 4), and it is still more preferred that they are 50 nm or more and less than 500 nm.

  As described above, the moth-eye mold has been described by way of example in which the mold release treatment is performed. However, in the mold release treatment method of the embodiment according to the present invention, the mold release treatment has a porous alumina layer on the surface other than the moth-eye mold. Can also be used. For example, it can be used for mold release treatment of a type for forming a photonic crystal.

  In the above, although the anti-reflective film was illustrated as a film provided with the surface which has a moth-eye structure, the type | mold by embodiment of this invention is not restricted to this, It can be widely applied to manufacture of the film provided with the surface which has a moth-eye structure .

  Furthermore, although the moth-eye mold for forming the moth-eye structure has been illustrated above, the mold according to the embodiment of the present invention is not limited thereto, and for example, a convex portion (for example, nanopillar) or the like having a blunt tip is formed It can be widely used in That is, the shape of the micro concave portion provided on the surface of the mold according to the embodiment of the present invention is not limited to a substantially conical shape, and may be, for example, a substantially truncated cone or a substantially cylindrical shape. The bottom of the micro recess is not limited to a point, and may be, for example, rounded or flat. The shape of the opening of the micro recess is not limited to a circle, and may be, for example, a rectangular shape. Also, the plurality of micro recesses may be regularly arranged or irregularly (randomly) arranged.

  The mold release treatment method according to the present invention can be used as a mold release treatment method of a mold for forming an antireflective film, a photonic crystal or the like.

14 porous alumina layer 50 mold release processing device 52 cover 52a 1st opening 52b 2nd opening 53 filter 54 HEPA filter 55 air flow supply device 56 pedestal 57 motor 57d drive shaft 58 rotation support structure 100 mold for moth eye 105 air flow

Claims (11)

(A) preparing a mold release agent containing a fluorine compound having mold release property and a solvent, and a cylindrical or cylindrical mold having a porous alumina layer on the surface;
(B) applying the mold release agent to the surface of the mold;
(C) drying the mold release agent applied in the step (b), wherein the mold comprises a first opening and a second opening of a cylindrical cover having a first opening and a second opening. Between the two openings, the axis of the mold is substantially parallel to the axis of the cover, and when viewed from the axial direction of the mold, the center of the cover and the center of the mold substantially coincide with each other. In the arranged state, when the diameter of the mold in a cross section perpendicular to the axis of the mold is D (m) with respect to the surface of the mold , at least 0.05 D in a direction parallel to the axis of the mold A drying step including the step of rotating the mold at least 0.5 rpm about the axis of the mold while generating an air flow flowing at (m / s) . The mold release treatment method according to claim 1, wherein in the step (c), the rotational speed of the mold is 10 rpm or less. In the step (c), when the flow velocity of the air flow is D (m) and the diameter of the mold in a cross section perpendicular to the axis of the mold is 0 .. The mold release treatment method according to claim 1 or 2, which is 52 D (m / s) or less. The process according to any one of claims 1 to 3, wherein, in the step (c), the step of generating the air flow includes the step of supplying a gas containing a solvent which dissolves the fluorine- based compound contained in the release agent. Of mold release processing method.   The mold release treatment method according to claim 4, wherein the gas containing the solvent contains the same solvent as the solvent contained in the mold release agent.   The surface of the porous alumina layer according to any one of claims 1 to 5, wherein the porous alumina layer has an inverted moth-eye structure having a plurality of recesses having a two-dimensional size of 50 nm or more and less than 500 nm when viewed in the normal direction of the surface. The mold release processing method as described in any one.   The mold release treatment method according to any one of claims 1 to 6, wherein the step (c) includes the step of supplying the air flow from the first opening. A process of preparing a mold which has been subjected to a release treatment by the release treatment method according to any one of claims 1 to 7 ;
Preparing a workpiece;
Curing the photocurable resin by irradiating the photocurable resin with light in a state in which the photocurable resin is applied between the mold and the surface of the workpiece;
And exfoliating an antireflective film formed of a cured photocurable resin from the mold. A cylindrical cover having a first opening and a second opening, wherein a cylindrical or cylindrical mold having a porous alumina layer on the surface is disposed between the first opening and the second opening of the cover. A cover disposed so that the center of the cover and the center of the mold substantially coincide with each other when viewed in the axial direction of the cover;
A rotational support structure, rotatably supported about the mold axis substantially parallel to the axis of the cover and configured to rotate the mold at least 0.5 rpm;
An air flow substantially parallel to the axis of the cover from the first opening, and the diameter of the mold in a cross section perpendicular to the axis of the mold is D (m), at least 0.05 D (m / s) An air flow supply device and an air flow supply device configured to supply an air flow having a flow velocity
A mold release processing apparatus.   The mold release processing apparatus according to claim 9, wherein the air flow supply device has a filter provided in the first opening. The rotary support structure comprises a motor and a pedestal coupled to a drive shaft of the motor,
The mold release processing apparatus according to claim 9 , wherein at least a part of the pedestal is located between the first opening and the second opening.

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