JP2017032756A - Transparent film and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent film having a fine uneven structure consisting of a plurality of projections formed with a period equal to or less than a wavelength in a visible light region on the surface, and a method for manufacturing the same.SOLUTION: The transparent film has first regions having a plurality of projections formed at a frequency equal to or more than a wavelength in a visible light region at both side ends of a long-sized base material film in the width direction and a second region having a layer including a fine uneven structure consisting of a plurality of projections formed at a frequency equal to or less than a wavelength in a visible light region on the surface. The second region is formed to be sandwiched by the first regions. The average height of the projections in the first regions is within ±25 μm of the thickness of the layer in the second region. A ratio W/H of each width W in the first region to the average height H of the projections in the first regions is 200-5000.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a transparent film having a fine concavo-convex structure on the surface and a method for producing the same.

  In recent years, it has been known that an article having a fine concavo-convex structure with a period equal to or shorter than the wavelength of visible light on the surface exhibits an antireflection effect, a lotus effect, and the like. In particular, the concavo-convex structure called the moth-eye structure in which substantially conical convex portions are arranged is an effective anti-reflection means by continuously increasing the refractive index from the refractive index of air to the refractive index of the material of the article. It is known that

  As a method for forming a fine concavo-convex structure on the surface of an article, a mold having a fine concavo-convex structure formed on the surface (also referred to as a mold; hereinafter referred to as a mold) is used. A method of transferring the structure to the surface of the article, more specifically, a liquid active energy ray-curable resin composition is filled between a mold having a fine concavo-convex structure on the surface and a base material, and active energy rays are applied to this. A method of forming a cured resin layer in which a fine concavo-convex structure is transferred to the surface of a base material by irradiating and curing is drawing attention. The transparent film having the fine concavo-convex structure produced by the above method on the surface is when the production speed is increased, or when the base film to be used has a high degree of smoothness, the winding of the roll or film at the stage of winding the transparent film Deformation may occur, and defects may be generated in the transferred fine uneven structure. That is, in the above method, when the roll film is wound up, the coalescence of the fine concavo-convex structure is locally generated, causing whitening of the produced transparent film having the fine concavo-convex structure, which may cause an increase in haze. Significantly affects product productivity.

Even before winding up the roll film of the above method, when the aspect ratio of the fine concavo-convex structure is high, or when a flexible active energy ray-curable resin composition is used for the fine concavo-convex structure, If a surface having a fine concavo-convex structure is in contact with the surface of a nip roll or a transport roll, whitening of the transparent film similar to the above may be caused and haze increase may be caused.
Moreover, also in the base film to be used, when a foreign material mixes in the wound roll film, for example, the optical film has an optical distortion defect. Many of these optical distortion defects are of a level that does not pose a problem with ordinary films, but since an article having a fine concavo-convex structure with a period shorter than the wavelength of visible light on its surface has a very low reflectance, Will be easily visible.
As a method for preventing such blocking of the base film, for example, Patent Document 1 proposes a method of coating the surface of the base film with an anti-blocking agent.
Moreover, in patent document 2, as a method of preventing the blocking of a base film and suppressing the optical distortion defect by the foreign material mixing of a roll film, it presses against the surface of a film edge part using an embossing roll, and the film | membrane of a film edge part There has been proposed a method of performing knurling by deforming the thickness bulky.

JP-A-60-110664 JP 2009-223129 A

However, the method of Patent Document 1 has the following problems.
When using a base film with an anti-blocking agent, it is highly slippery with the mold and transport roll, so it slips on the mold and damages the mold, or active energy ray curing is applied to the slipped part. In some cases, the photosensitive resin composition does not spread and transfer omission occurs. Moreover, the base film which added the antiblocking agent to the surface may deteriorate the adhesiveness of the active energy ray-curable resin composition to be transferred, and reduce the productivity of the article.

Further, the method of Patent Document 2 has the following problems.
Even if both ends of the base film are knurled, if the height of the knurling is too low with respect to the thickness of the layer having the fine concavo-convex structure, the knurling effect may not be exhibited. That is, when a roll film is wound up or when a surface having a fine concavo-convex structure is brought into contact with the surface of a nip roll or a transport roll, unification of the fine concavo-convex structure occurs locally, and the transparent having the produced fine concavo-convex structure It may cause whitening of the film and increase haze. Furthermore, when the knurling process is low, the optical distortion defect of the roll film that has been unrolled is not completely suppressed, and thus the optical distortion defect may be visually recognized.
On the other hand, when the height of the knurling is high, the roll diameter of the roll becomes large, which causes a decrease in productivity. Also, unless the width of the knurling portion is wide, the wound roll cannot be wound well and wrinkles may occur.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the transparent film which has the fine concavo-convex structure which suppressed whitening and transfer omission on the surface, and its manufacturing method.

  As a result of intensive studies, the inventors of the present invention have found that a plurality of convex portions (hereinafter referred to as first regions) provided with a period equal to or greater than the wavelength of visible light at both end portions in the width direction of the base film. Film thickness of a layer having a fine concavo-convex structure including a plurality of convex portions formed with a period equal to or less than the average height of the convex portions and the wavelength of visible light (hereinafter, a region provided with this layer is referred to as a second region). When the above relationship is optimal, the present inventors have found that whitening and transfer omission in the second region can be suppressed without winding the transparent film, and the present invention has been completed.

That is, this invention has the following aspects.
[1] A first region in which a plurality of convex portions are formed at both ends in the width direction of the long base film at a period equal to or longer than the wavelength of the visible light region;
A transparent film having a second region provided with a layer having a fine concavo-convex structure consisting of a plurality of convex portions formed at a period of a wavelength equal to or less than the wavelength of the visible light region on the surface,
The second region is formed so as to be sandwiched between the first regions, and the average height of the convex portions of the first region is within the range of the film thickness of the layer of the second region ± 25 μm. A transparent film, wherein the ratio W / H of the width W of each of the regions and the average height H of the convex portions of the first region is 200 to 5000.
[2] A method for producing a transparent film according to [1],
(I) An active energy ray-curable resin composition is formed on the base film in which a plurality of convex portions are formed at both ends in the width direction of the long base film at a period equal to or longer than the wavelength of the visible light region. Applying step;
(II) The active energy ray curable resin composition applied to the transparent film is pressed against the transfer mold and irradiated with the active energy ray to cure the active energy ray curable resin composition and form the transfer die. Transferring the formed uneven shape onto the surface of the active energy ray-curable resin, and forming a fine uneven structure on the base film,
(III) comprising a step of separating the transparent film and the mold,
A method for producing a transparent film.

  According to the transparent film of the present invention and the method for producing the same, blocking of the roll film and optical distortion defects can be suppressed, and whitening and transfer loss can be prevented.

It is sectional drawing which shows the manufacturing process of the metal mold | die which has an anodized alumina on the surface. It is a block diagram which shows an example of the manufacturing apparatus of the transparent film which has a fine uneven structure on the surface. It is a top view which shows an example of the base film which has a 1st area | region in the both ends of the width direction. It is sectional drawing which shows an example of the base film which has a 1st area | region in the both-sides edge part of the width direction. It is sectional drawing which shows an example of the transparent film which has a 1st area | region and a fine concavo-convex structure on the surface. It is sectional drawing which shows the other example of the transparent film which has a 1st area | region and a fine concavo-convex structure on the surface. It is sectional drawing which shows the example of the transparent film which has a 1st area | region in a back surface and has a fine concavo-convex structure on the surface. It is sectional drawing which shows the state which accumulated the transparent film shown by FIG.

Hereinafter, the present invention will be described in detail.
In the present specification, the “fine concavo-convex structure” means a structure in which the average interval (center-to-center distance) between adjacent convex portions or adjacent concave portions is not more than the visible light wavelength, that is, 400 nm or less.
The “active energy ray” means visible light, ultraviolet light, electron beam, plasma, heat ray (infrared ray or the like) and the like.
Further, “transparent” means transmitting at least light having a wavelength of 400 to 760 nm.
Further, the “pore” means a concave portion having a fine concavo-convex structure formed on an oxide film on the surface of an aluminum substrate.
The “interval between pores” means the distance between the centers of adjacent pores.
The “projection” refers to a convex portion having a fine concavo-convex structure formed on the surface of the transparent film.
“(Meth) acrylate” is a generic term for acrylate and methacrylate, “(meth) acrylic acid” is a generic term for acrylic acid and methacrylic acid, and “(meth) acrylonitrile” is a generic term for acrylonitrile and methacrylonitrile. “(Meth) acrylamide” is a general term for acrylamide and methacrylamide.
“(Poly) oxyalkylene alkyl phosphate compound” is a generic term for an oxyalkylene alkyl phosphate compound having one oxyalkylene group and a polyoxyalkylene alkyl phosphate compound having two or more oxyalkylene groups. is there.

"Transparent film manufacturing method"
A method for producing a transparent film having a fine concavo-convex structure having a plurality of convex portions having a period (that is, an interval between convex portions) of 400 nm or less on the surface includes the following steps (I) to (III).
Step (I): A step of manufacturing a mold in which an inverted structure of the fine concavo-convex structure including a plurality of concave portions is formed on the surface.
Step (II): An active energy ray-curable resin composition is supplied to the surface of the mold having the inverted structure of the fine relief structure, and the active energy ray-curable resin composition is irradiated with active energy rays. Curing the active energy ray-curable resin composition to obtain a transparent film having the fine concavo-convex structure on the surface.
Step (III): A step of separating the transparent film and the mold.
Hereinafter, each step will be described in detail.

<Process (I)>
Step (I) is a step of manufacturing a mold having on its surface an inverted structure of the fine uneven structure (hereinafter also referred to as “inverted fine uneven structure”). Hereinafter, the surface of the mold having the inverted fine concavo-convex structure is also referred to as “mold surface”.
Examples of the material for the mold base include metals (including those having an oxide film formed on the surface), quartz, glass, resin, ceramics, and the like. Alternatively, a metal, quartz, glass, resin, or ceramic base material on which metal or the like is formed can be used.
Examples of the shape of the mold include a roll shape, a belt shape, and a flat plate shape. Among these, a roll shape or a belt shape is preferable from the viewpoint that the inverted fine concavo-convex structure of the mold can be continuously transferred and the productivity can be further increased.

Examples of the method for producing a mold include the following method (i-1) or method (i-2), and the method (i-) is possible because the area can be increased and the production is simple. 1) is particularly preferred.
(I-1) A method of forming anodized alumina having a plurality of pores (recesses) on the surface of an aluminum substrate.
(I-2) A method of forming a fine relief structure on the surface of a mold base by lithography.

As the method (i-1), a method having the following steps (a) to (f) is preferable.
(A) A step of forming an oxide film on the surface of an aluminum substrate by anodizing the aluminum substrate in an electrolytic solution under a constant voltage.
(B) A step of removing the oxide film and forming anodic oxidation pore generation points on the surface of the aluminum substrate.
(C) A step of anodizing the aluminum substrate again in the electrolytic solution to form an oxide film having pores at the pore generation points.
(D) A step of enlarging the diameter of the pores.
(E) A step of anodizing again in the electrolytic solution after the step (d).
(F) A step of repeating steps (d) and (e) to obtain a mold in which anodized alumina having a plurality of pores is formed on the surface of an aluminum substrate.

Step (a): As shown in FIG. 1, when the aluminum substrate 10 is anodized, an oxide film 14 having pores 12 is formed.
Examples of the shape of the aluminum substrate include a roll shape, a circular tube shape, a flat plate shape, and a sheet shape.
The aluminum base material is preferably polished by mechanical polishing, feather polishing, chemical polishing, electrolytic polishing treatment (etching treatment) or the like in order to smooth the surface state.
Moreover, since the oil used when processing an aluminum base material in a defined shape may adhere, it is preferable to degrease in advance before anodizing.

The purity of aluminum is preferably 99% or more, more preferably 99.5% or more, and particularly preferably 99.8% or more.
When the purity of aluminum is low, when anodized, an uneven structure having a size to scatter visible light may be formed due to segregation of impurities, or the regularity of pores obtained by anodization may be lowered. In addition, you may use the base material by which the above-mentioned aluminum was formed into a film on the base material of another metal, quartz, glass, resin, and ceramics, without comprising the whole metal mold | die from high purity aluminum material.
Examples of the electrolytic solution include sulfuric acid, oxalic acid, and phosphoric acid.

When using oxalic acid as the electrolyte: The concentration of oxalic acid is preferably 0.7 M or less.
When the concentration of oxalic acid exceeds 0.7M, the current value becomes too high, and the surface of the oxide film may become rough.
When the formation voltage is 30 to 60 V, anodized alumina having highly regular pores with an average interval of about 100 nm can be obtained.
Regardless of whether the formation voltage is higher or lower than this range, the regularity tends to decrease.
The temperature of the electrolytic solution is preferably 60 ° C. or lower, and more preferably 45 ° C. or lower.
When the temperature of the electrolytic solution exceeds 60 ° C., a so-called “burn” phenomenon occurs, and the pores may be broken, or the surface may melt and the regularity of the pores may be disturbed.

When sulfuric acid is used as the electrolytic solution: The concentration of sulfuric acid is preferably 0.7 M or less.
If the concentration of sulfuric acid exceeds 0.7M, the current value may become too high to maintain a constant voltage.
When the formation voltage is 25 to 30 V, anodized alumina having highly regular pores with an average interval of 63 nm can be obtained.
The regularity tends to decrease whether the formation voltage is higher or lower than this range.
The temperature of the electrolytic solution is preferably 30 ° C. or less, and more preferably 20 ° C. or less.
When the temperature of the electrolytic solution exceeds 30 ° C., a so-called “burn” phenomenon occurs, and the pores may be broken or the surface may melt and the regularity of the pores may be disturbed.

  Step (b): As shown in FIG. 1, the regularity of the pores can be improved by removing the oxide film 14 once and using it as the pore generation points 16 for anodic oxidation. Note that, as shown in the step (b ′), the oxide film 14 may not be completely removed, and only the region where the interval between the pores is not uniform may be deleted. After step (b ′), step (c) described later is performed, but step (c) may be omitted and step (d) or step (e) may be performed directly.

As a method of removing the oxide film, a method of dissolving and removing the oxide film may be used, and it is preferable to use a method of dissolving and removing the oxide film in a solution that selectively dissolves the aluminum film without dissolving aluminum. .
Examples of the solution that selectively dissolves the oxide film include a chromic acid / phosphoric acid mixed solution.

Step (c): As shown in FIG. 1, when the aluminum substrate 10 from which the oxide film has been removed is anodized again, an oxide film 14 having cylindrical pores 12 is formed.
Anodization may be performed under the same conditions as in step (a).
Deeper pores can be obtained as the anodic oxidation time is lengthened.

Step (d): As shown in FIG. 1, a process of expanding the diameter of the pores 12 (hereinafter referred to as a pore diameter expansion process) is performed.
The pore diameter expansion treatment is a treatment for expanding the diameter of the pores obtained by anodic oxidation by immersing in a solution dissolving the oxide film.
Examples of such a solution include a phosphoric acid aqueous solution of about 5% by mass.
The longer the pore diameter expansion processing time, the larger the pore diameter.

Step (e): As shown in FIG. 1, when anodized again, cylindrical pores 12 having a small diameter that extend downward from the bottom of the cylindrical pores 12 are further formed.
Anodization may be performed under the same conditions as in step (a).
Deeper pores can be obtained as the anodic oxidation time is lengthened.

Step (f): As shown in FIG. 1, when the pore diameter enlargement process in step (d) and the anodization in step (e) are repeated, the diameter continuously decreases in the depth direction from the opening. An oxide film 14 having pores 12 is formed, and a mold 18 having anodized alumina (aluminum porous oxide film (alumite)) on the surface of the aluminum substrate 10 is obtained.
It is preferable that the last end is step (d).

The total number of repetitions is preferably 3 times or more, and more preferably 5 times or more.
When the number of repetitions is 2 times or less, the diameter of the pores decreases discontinuously, so that the effect of reducing the reflectance of the moth-eye structure formed using anodized alumina having such pores is insufficient.

Examples of the shape of the pore 12 include a substantially conical shape, a pyramid shape, a cylindrical shape, and the like. A shape that continuously decreases in the direction is preferred.
The average interval between the pores 12 is not more than the wavelength of visible light, that is, not more than 400 nm.
The average interval between the pores 12 is preferably 20 nm or more.
The average interval between the pores 12 was measured by measuring the distance between adjacent pores 12 (the distance from the center of the pore 12 to the center of the adjacent pore 12) by electron microscope observation, and averaging these values. It is a thing.

When the average interval is 100 nm, the depth of the pores 12 is preferably 80 to 500 nm, more preferably 120 to 400 nm, and particularly preferably 150 to 300 nm.
The depth of the pore 12 is a value obtained by measuring the distance between the bottom of the pore 12 and the top of the convex portion existing between the pores 12 when observed with an electron microscope at a magnification of 30000 times. It is.
The aspect ratio of the pores 12 (depth of pores / average interval between pores) is preferably 0.8 to 5.0, more preferably 1.2 to 4.0, and 1.5 to 3.0. Is particularly preferred.

Next, the surface of the mold where the fine concavo-convex structure is formed is treated with an external release agent.
As the external release agent, those having a functional group capable of forming a chemical bond with the anodized alumina of the aluminum substrate are preferable.
Strictly speaking, a mold having a fine concavo-convex structure on the surface is a treatment of the surface of the fine concavo-convex structure with a release agent. It may be described that “the surface of the mold” is treated.

Examples of the external release agent include silicone resins, fluororesins, and fluorine compounds, and it is preferable to use a fluorine compound having a hydrolyzable silyl group.
Commercially available fluorine compounds having hydrolyzable silyl groups include fluoroalkylsilane, KBM-7803 (manufactured by Shin-Etsu Chemical Co., Ltd.), MRAF (Asahi Glass), OPTOOL HD1100, HD2100 series (manufactured by Harves), OPTOOL AES4, AES6 (Manufactured by Daikin Industries), Novec EGC-1720 (manufactured by Sumitomo 3M), FS-2050 series (manufactured by Fluoro Technology), and the like.
Fluorine-containing compounds, silicone compounds, phosphate ester compounds, compounds having a long-chain alkyl group, compounds having a polyoxyalkylene group, solid wax that can be used as an internal release agent for an active energy ray-curable resin composition (Polyethylene wax, amide wax, polytetrafluoroethylene powder, etc.) etc. diluted with a solvent can also be used.

Examples of the treatment method using an external release agent include the following method (ii-1) or method (ii-2), and the surface on the side where the fine concavo-convex structure of the mold is formed can be uniformly applied with the external release agent. The method (ii-1) is particularly preferable because it can be treated.
(Ii-1) A method of immersing the mold body in a dilute solution of an external mold release agent.
(Ii-2) A method of applying an external mold release agent or a diluted solution thereof to the surface of the mold on which the fine uneven structure is formed.

As the method (ii-1), a method having the following steps (g) to (l) is preferable.
(G) A step of washing the mold with water.
(H) After step (g), air is blown onto the mold to remove water droplets attached to the surface of the mold.
(I) A step of immersing the mold in a diluted solution in which a fluorine compound having a hydrolyzable silyl group is diluted with a fluorine-based solvent.
(J) A step of slowly lifting the immersed mold from the solution.
(K) A step of heating and humidifying the mold after the step (j) as necessary.
(L) A step of drying the mold body.

  Step (g): The mold contains the chemicals used when forming the fine relief structure (phosphoric acid aqueous solution used for pore diameter enlargement processing, stripping solution used for lithography, etc.), impurities (dust etc.), etc. Since it adheres, it is removed by washing with water.

  Step (h): If water droplets adhere to the surface of the mold, the diluted solution in step (i) deteriorates, so air is blown onto the mold, and visible water droplets are almost removed.

Step (i): Examples of the fluorine-based solvent for dilution include hydrofluoropolyether, perfluorohexane, perfluoromethylcyclohexane, perfluoro-1,3-dimethylcyclohexane, dichloropentafluoropropane, and the like.
As for the density | concentration of the fluorine compound which has a hydrolyzable silyl group, 0.01-0.5 mass% is preferable in a diluted solution (100 mass%).
The immersion time is preferably 1 to 30 minutes.
As for immersion temperature, 0-50 degreeC is preferable.

Step (j): When the soaked mold is pulled up from the solution, it is preferable to pull it up at a constant speed using an electric puller or the like to suppress swinging during the pulling.
This can reduce coating unevenness.
The pulling speed is preferably 1 to 10 mm / sec.

Step (k): The mold may be heated and humidified after the step (j).
By leaving the mold under heating and humidification, the hydrolyzable silyl group of the fluorine compound (release agent) is hydrolyzed to form a silanol group, and the reaction between the silanol group and the hydroxyl group on the mold surface is caused. It proceeds sufficiently and improves the fixability of the fluorine compound.
As the humidification method, a saturated salt method using a saturated salt aqueous solution, a method of heating and humidifying water, a method of directly spraying heated steam on a mold, and the like are conceivable.
This step may be performed in a constant temperature and humidity chamber.
The heating temperature is preferably 30 to 150 ° C.
The humidification condition is preferably a relative humidity of 60% or more.
The standing time is preferably 10 minutes to 7 days.

Step (l): In the step of drying the mold, the mold may be air-dried or forcibly heated and dried with a dryer or the like.
The drying temperature is preferably 30 to 150 ° C.
The drying time is preferably 5 to 300 minutes.

When the mold surface is treated with the external mold release agent as described above, it can be confirmed by measuring the water contact angle of the mold surface that the mold surface has been treated with the external mold release agent.
The water contact angle on the surface of the mold treated with an external release agent is preferably 60 ° or more, and more preferably 90 ° or more.
When the water contact angle is 60 ° or more, the surface of the mold is sufficiently treated with an external release agent, and the release property is improved.

When transferring the fine uneven structure of the mold to the surface of the article by treating the surface on the side where the fine uneven structure of the mold is formed with an external release agent capable of forming a chemical bond with the mold, The releasability of is improved.
In addition, even when it is repeatedly transferred, the releasability is hardly lowered, and thus an article having a fine concavo-convex structure on the surface can be manufactured with high productivity.

<Step (II), Step (III)>
Process (II) and process (III) are performed using the manufacturing apparatus shown, for example in FIG.
Step (II) is a step of obtaining a transparent film having a fine concavo-convex structure on the surface using the mold obtained in step (I).
Step (III) is a step of separating the transparent film and the mold obtained in step (I).

  In step (II), an active energy ray-curable resin composition is supplied to the surface of the mold obtained in step (I) on the side having the inverted fine uneven structure, and the active energy ray-curable resin composition is supplied to the active energy ray-curable resin composition. The active energy ray-curable resin composition is cured by irradiating active energy rays to obtain a transparent film having the fine uneven structure on the surface. At this time, the active energy ray-curable resin composition is cured in a state sandwiched between the mold and the base material, and a cured resin layer to which the inverted fine uneven structure of the mold is transferred is formed on the surface of the base material. It is preferable to do.

Examples of the shape of the substrate include films, sheets, injection molded products, press molded products, extruded molded products, cast molded products, and the like.
As a base material, since active energy ray irradiation is performed over a base material, the thing of a material with high light transmittance is preferable. Examples of highly light transmissive materials include polycarbonate, polystyrene resin, polyester, polyurethane, acrylic resin, polyether sulfone, polysulfone, polyether ketone, cellulose resin (triacetyl cellulose, etc.), polyolefin, and alicyclic. Examples include polyolefin and glass.
The surface of the substrate may be subjected to coating, corona treatment, etc. for the purpose of improving properties such as adhesion, antistatic properties, scratch resistance, and weather resistance.

  The long base film used as the base material of the present embodiment has a period equal to or greater than the wavelength of the visible light region at both side ends in the width direction (the period here is between adjacent convex parts described later) A first region in which a plurality of convex portions are formed. FIG. 3 is a top view of an example of the base film. The first region 43 (hereinafter, unless otherwise specified, the same applies to the first region 43 ′ and the first region 43 ″ in other embodiments to be described later) at both ends in the width direction of the base film 42. .) Is provided. (Note that the shape of the convex portion provided in the first region 43 is not shown in FIG. 3 because it is very small.) Each of the base film 42 is spaced from the right end and the left end by a few millimeters. Although it is preferable to provide the first region 43, the first region may be provided to the right end and the left end of the base film 42, respectively, without leaving these intervals. This first region is formed by previously pressing an embossing roll (not shown) on the surface of both end portions in the width direction of the base film, and performing knurling by deforming the film thickness of the film end portion in a bulky manner. be able to. FIG. 4 is a cross-sectional view showing an example of the base film 42 in which the first region 43 is formed.

  The average interval (center-to-center distance) between adjacent convex portions in the first region is not less than the visible light wavelength, that is, not less than about 800 nm, and preferably “100 μm to 1 mm”.

The average width W of each of the first regions 43 is preferably 2 mm to 50 mm, more preferably 3 mm to 30 mm, and particularly preferably 5 mm to 25 mm. If average width W is 3 mm-50 mm, when winding a elongate base film, it will not generate winding, a wrinkle, and a deformation | transformation of a film. Even when the average width W is 50 mm or more, there is an effect of suppressing the winding of the roll and wrinkles, but the width that can be used as a product is narrowed, and the productivity is lowered. When the average width W is 3 mm or less, winding of the transparent film is likely to occur, and as a result, winding or wrinkling may occur.
Moreover, the height of the convex part of the 1st area | region 43 is the distance from the surface of the base film 42 to the topmost part of the convex part of the 1st area | region 43, and average height H of the convex part of a 1st area | region 43 Is preferably in the range of 2 μm to 50 μm, more preferably 3 μm to 30 μm, and particularly preferably 5 μm to 25 μm. When the average height H is 1 μm to 50 μm, the roll winding diameter of the transparent film is not increased and wrinkles are not generated.
The convex part of the 1st field may be formed in the surface of a substrate film, and may be formed in the back. It can be selectively formed by applying the knurling process described above to the surface of the base film or the back surface. In FIGS. 5 and 6 to be described later, examples of the transparent films 40 and 40 ′ in which the convex portions of the first regions 43 and 43 ′ are formed on the surface of the base film 42 are shown in cross-sectional views. 7 shows a cross-sectional view of an example of a transparent film 40 ″ in which the convex portions of the first region 43 ″ are formed on the back surface of the base film 42. FIG. 8 is a cross-sectional view showing a case where the transparent film shown in FIG. 7 is overlaid.

In the first region of the transparent film, the ratio W / H of the average width W of each of the first regions and the average height H of the convex portions of the first region is preferably 200 to 5000. When W / H is 200 to 5000, a good transparent film can be produced without causing winding or wrinkles, film deformation, or winding deviation when winding a long base film. .
When the first region of the base film is pressed against the mold, the active energy ray-curable resin composition of the second region to be described later is reduced by lowering the average height of the convex portions of the first region. The film thickness of the layer can be made uniform. Furthermore, it is possible to suppress the generation | occurrence | production of the crack of the part which contacts a metal mold | die. When the film thickness is made uniform, warpage as a transparent film can be reduced.
In addition, by appropriately adjusting the relationship between the average height of the convex portions in the first region and the film thickness of the layer in the second region, the winding of the roll and the deformation of the film at the stage of winding the transparent film are prevented. It is possible to suppress the occurrence of defects in the fine concavo-convex structure of the second region described later. Even if it is before winding up a roll film, a 1st area | region uses the active energy ray-curable resin composition flexible to the case where the aspect ratio of the fine concavo-convex structure of a 2nd area | region is high, or a fine concavo-convex structure. In this case, it is possible to suppress whitening and haze increase due to nip rolls and transport rolls. In addition, in the case where an optical distortion defect due to contamination of foreign matter occurs in the second region having a fine concavo-convex structure in particular, the reflectance is low and it is easily visually recognized. By having the region, it is possible to suppress the occurrence of optical distortion defects even when foreign matter is mixed into the wound transparent film.

Here, step (II) and step (III) will be described in detail. Process (II) and process (III) are performed as follows using the manufacturing apparatus shown in FIG.
From the tank 22 between a roll-shaped mold 20 having an inverted fine concavo-convex structure (not shown) on the surface and a strip-shaped base material (base film) 42 that moves along the surface of the roll-shaped mold 20. An active energy ray-curable resin composition 24 is supplied.

  A base in which first regions (not shown in FIG. 2) are provided at both end portions in the width direction between the roll-shaped mold 20 and the nip roll 28 whose nip pressure is adjusted by the pneumatic cylinder 26. The material film 42 and the active energy ray curable resin composition 24 are nipped, and the active energy ray curable resin composition 24 is uniformly distributed between the base film 42 and the roll mold 20, and at the same time a roll shape. The mold 20 is filled into the recesses (pores) of the inverted fine uneven structure.

The active energy ray curable resin composition 24 is irradiated from the active energy ray irradiation device 30 installed below the roll-shaped mold 20 through the base film 42 to the active energy ray curable resin composition 24. Is cured to form a cured resin layer 44 to which the inverted fine concavo-convex structure on the surface of the roll-shaped mold 20 is transferred.
By peeling the base film 42 having the cured resin layer 44 formed on the surface thereof from the roll-shaped mold 20 by the peeling roll 32, the transparent film 40 as shown in FIGS. 5, 6, and 7 is continuously formed. To manufacture.

The active energy ray-curable resin layer 44 corresponding to the second region 47 shown in FIGS. 5, 6, and 7 may be a single layer or a multilayer. The film thickness of the second region layer is preferably in the range of 1 μm to 50 μm, more preferably 2 μm to 30 μm, and particularly preferably 3 μm to 15 μm. If the film thickness is 1 μm to 50 μm, the flexibility of the transparent film can be maintained and the generation of wrinkles can be suppressed. Note that the film thickness of the layer in the second region refers to the height from the surface on which the cured resin layer 44 is formed on the base material to the tops of the plurality of convex portions 46.
The active energy ray-curable resin composition 24 that constitutes the active energy ray-curable resin layer 44 corresponding to the second region 47 is generally hard and, therefore, if the film thickness becomes too thick, warping becomes high. Or the flexibility as a transparent film is impaired. On the other hand, when the film thickness is thin, the flexibility of the transparent film can be maintained, but when it is too thin, the scratch resistance of the fine concavo-convex structure is reduced, or interference fringes are caused by the difference in refractive index from the base film. It tends to occur.

(Active energy ray-curable resin composition)
The active energy ray-curable resin composition includes a polymerizable compound and a polymerization initiator.
Examples of the polymerizable compound include monomers, oligomers, and reactive polymers having a radical polymerizable bond and / or a cationic polymerizable bond in the molecule.
Examples of the monomer having a radical polymerizable bond include a monofunctional monomer and a polyfunctional monomer.

Polymerizable compound:
Examples of the monomer having a radical polymerizable bond include a monofunctional monomer and a polyfunctional monomer.
Monofunctional monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, s-butyl (meth) acrylate, t- Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, alkyl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, Phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, allyl (meth) acrylate, 2-hydroxyethyl ( )) (Meth) acrylate derivatives such as acrylate, hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate; (meth) acrylic acid; (meth) acrylonitrile; styrene, α -Styrene derivatives such as methylstyrene; (meth) acrylamide derivatives such as (meth) acrylamide, N-dimethyl (meth) acrylamide, N-diethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide and the like. These may be used alone or in combination of two or more.

  Polyfunctional monomers include ethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, isocyanuric acid ethylene oxide modified di (meth) acrylate, triethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate , Neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,5-pentanediol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, polybutylene glycol di (Meth) acrylate, 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 2,2-bis (4- (meth) acryloxyethoxyphenyl) propane, 2,2-bis (4- (3- ( Ta) acryloxy-2-hydroxypropoxy) phenyl) propane, 1,2-bis (3- (meth) acryloxy-2-hydroxypropoxy) ethane, 1,4-bis (3- (meth) acryloxy-2-hydroxypropoxy) ) Butane, dimethylol tricyclodecane di (meth) acrylate, ethylene oxide adduct di (meth) acrylate of bisphenol A, propylene oxide adduct di (meth) acrylate of bisphenol A, neopentyl glycol di (meth) hydroxypivalate Bifunctional monomers such as acrylate, divinylbenzene, and methylenebisacrylamide; pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane ethylene oxide Trifunctional monomers such as tri (meth) acrylate, trimethylolpropane propylene oxide modified triacrylate, trimethylolpropane ethylene oxide modified triacrylate, isocyanuric acid ethylene oxide modified tri (meth) acrylate; succinic acid / trimethylolethane / acrylic acid Condensation reaction mixture, dipentaerythrole hexa (meth) acrylate, dipentaerystol penta (meth) acrylate, ditrimethylolpropane tetraacrylate, tetramethylolmethane tetra (meth) acrylate and other tetrafunctional or higher monomers; bifunctional or higher functional Examples thereof include urethane acrylate and bifunctional or higher functional polyester acrylate. These may be used alone or in combination of two or more.

  Examples of the monomer having a cationic polymerizable bond include a monomer having an epoxy group, an oxetanyl group, an oxazolyl group, a vinyloxy group, and the like, and a monomer having an epoxy group is particularly preferable.

  Examples of the oligomer or reactive polymer include unsaturated polyesters such as a condensate of unsaturated dicarboxylic acid and polyhydric alcohol; polyester (meth) acrylate, polyether (meth) acrylate, polyol (meth) acrylate, epoxy (meth) Examples thereof include acrylates, urethane (meth) acrylates, cationic polymerization type epoxy compounds, homopolymers of the above-described monomers having a radical polymerizable bond in the side chain, and copolymerized polymers.

Polymerization initiator:
As the polymerization initiator, a compound that generates radicals or cations when irradiated with active energy rays is used. From the viewpoint of apparatus cost and productivity, a photopolymerization initiator using ultraviolet rays as an active energy ray is preferable.

  When using a photocuring reaction, examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl, benzophenone, p-methoxybenzophenone, and 2,2-diethoxyacetophenone. , Α, α-dimethoxy-α-phenylacetophenone, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylamino) benzophenone, 2-hydroxy-2-methyl-1-phenylpropane-1 Carbonyl compounds such as -one; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoyldi Such as butoxy phosphine oxide. These may be used alone or in combination of two or more.

  When using an electron beam curing reaction, examples of the polymerization initiator include benzophenone, 4,4-bis (diethylamino) benzophenone, 2,4,6-trimethylbenzophenone, methyl orthobenzoyl benzoate, 4-phenylbenzophenone, and t-butyl. Thioxanthones such as anthraquinone, 2-ethylanthraquinone, 2,4-diethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl Ketal, 1-hydroxycyclohexyl-phenyl ketone, 2-methyl-2-morpholino (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholino Acetyl) -butanone and the like; benzoin ethers such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether and benzoin isobutyl ether; 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl)- Acylphosphine oxides such as 2,4,4-trimethylpentylphosphine oxide and bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; methylbenzoylformate, 1,7-bisacridinylheptane, 9-phenyl Examples include acridine. These may be used alone or in combination of two or more.

  When utilizing a thermosetting reaction, examples of the thermal polymerization initiator include methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxy octoate, organic peroxides such as t-butylperoxybenzoate and lauroyl peroxide; azo compounds such as azobisisobutyronitrile; N, N-dimethylaniline, N, N-dimethyl-p- Examples thereof include a redox polymerization initiator combined with an amine such as toluidine. These may be used alone or in combination of two or more.

  The content of the polymerization initiator in the active energy ray-curable resin composition is preferably 0.1 to 10.0 parts by mass with respect to 100 parts by mass of the polymerizable compound. If content of a polymerization initiator is 0.1 mass part or more, superposition | polymerization will fully advance. On the other hand, if content of a polymerization initiator is 10.0 mass parts or less, the hardened | cured material (cured resin layer) of an active energy ray-curable resin composition will be hard to color, and the fall of mechanical strength can also be suppressed.

Internal mold release agent:
When the active energy ray-curable resin composition contains an internal release agent, continuous transferability can be improved.
The internal mold release agent improves the mold releasability between the cured resin layer and the mold surface, and is compatible with components other than the internal mold release agent contained in the active energy ray-curable resin composition. For example, the composition of the internal release agent is not particularly limited.
Examples of the internal release agent include (poly) oxyalkylene alkyl phosphate ester compounds, phosphate ester compounds other than (poly) oxyalkylene alkyl phosphate ester compounds, fluorine-containing compounds, silicone compounds, and long-chain alkyl groups. And a compound having a polyoxyalkylene group, solid wax (polyalkylene wax, amide wax, polytetrafluoroethylene powder, etc.), and the like. These may be used alone or in combination of two or more. Among these, (poly) oxyalkylene alkyl phosphate ester compounds are preferable.

  When the active energy ray-curable resin composition contains a (poly) oxyalkylene alkyl phosphate ester compound as an internal release agent, the release property between the cured resin layer that is the cured product and the mold is better. Become. Further, since the load at the time of mold release is extremely low, the fine concavo-convex structure is hardly damaged, and as a result, the inverted fine concavo-convex structure of the mold can be transferred efficiently and accurately. In particular, if the mold surface is subjected to a mold release treatment using a (poly) oxyalkylene alkyl phosphate compound as an external mold release agent, the mold releasability between the cured resin layer and the mold is further enhanced.

The (poly) oxyalkylene alkyl phosphate compound is preferably a compound represented by the following formula (1) from the viewpoint of releasability.
_{(HO) 3-n (O} =) P [-O- (R 2 O) m-R 1] n ··· (1)
In the formula (1), R ¹ is an alkyl group, R ² is an alkylene group, m is an integer of 1 to 20, n is an integer of 1-3.

The R ^1, preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 3 to 18 carbon atoms.
R ² is preferably an alkylene group having 1 to 4 carbon atoms, more preferably an alkylene group having 2 to 3 carbon atoms.
m is preferably an integer of 1 to 10.

  The (poly) oxyalkylene alkyl phosphate compound may be a monoester (n = 1), a diester (n = 2), or a triester (n = 3). In the case of a diester or triester, a plurality of (poly) oxyalkylene alkyl groups in one molecule may be different from each other.

Examples of commercially available (poly) oxyalkylene alkyl phosphate compound include the following.
Johoku Chemical Co., Ltd .: JP-506H,
Accelerator: Mold with INT-1856,
Nikko Chemicals: TDP-10, TDP-8, TDP-6, TDP-2, DDP-10, DDP-8, DDP-6, DDP-4, DDP-2, TLP-4, TCP-5, DLP -10.
The (poly) oxyalkylene alkyl phosphate ester compound may be used alone or in combination of two or more.

  The mold of the active energy ray-curable resin composition having a fine concavo-convex structure with a content of (poly) oxyalkylene alkyl phosphate ester compound of 100 parts by mass of the polymerizable compound and having a wavelength of normal visible light or less. If it is, 0.01-1 mass part is preferable, 0.05-0.5 mass part is more preferable, 0.05-0.1 mass part is further more preferable. When the amount of the (poly) oxyalkylene alkyl phosphate compound is 1 part by mass or less, a decrease in the performance of the cured resin layer can be suppressed. Moreover, the fall of adhesiveness with a light transmissive base material is suppressed, As a result, the resin residue (mold release defect) to a metal mold | die and peeling of the cured resin layer from articles | goods are suppressed. If the amount of the (poly) oxyalkylene alkyl phosphate compound is 0.01 parts by mass or more, the releasability from the mold will be sufficient, and the resin residue (unsatisfactory mold release) on the mold will be suppressed.

  The active energy ray-curable resin composition is also referred to as an internal mold release agent other than the (poly) oxyalkylene alkyl phosphate compound (hereinafter referred to as “other internal mold release agent”) for the purpose of further improving mold release properties. ) May be included. Other internal mold release agents include those described above.

<< Other ingredients >>
The active energy ray-curable resin composition is made of a non-reactive polymer, an active energy ray sol-gel reactive composition, an antistatic agent, an additive such as a fluorine compound for improving antifouling properties, and fine particles as necessary. A small amount of a solvent may be contained.

Examples of non-reactive polymers include acrylic resins, styrene resins, polyurethanes, cellulose resins, polyvinyl butyral, polyesters, thermoplastic elastomers, and the like.
Examples of the active energy ray sol-gel reactive composition include alkoxysilane compounds and alkyl silicate compounds.

Examples of the alkoxysilane compound include tetramethoxysilane, tetra-i-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-s-butoxysilane, tetra-t-butoxysilane, methyltriethoxysilane, Examples include methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, trimethylpropoxysilane, and trimethylbutoxysilane.
Examples of the alkyl silicate compound include methyl silicate, ethyl silicate, isopropyl silicate, n-propyl silicate, n-butyl silicate, n-pentyl silicate, acetyl silicate and the like.

  The cured product (cured resin layer) of the active energy ray-curable resin composition may be hydrophobic or hydrophilic. By changing the cured product of the active energy ray-curable resin composition to hydrophobic or hydrophilic, performance (for example, water resistance and fingerprint wiping property) can be imparted to the transparent film as necessary.

Hydrophobic material:
When the transparent film is required to have water repellency (specifically, the water contact angle of the surface of the fine uneven structure of the cured resin layer is 90 ° or more), active energy ray curing that can form a hydrophobic material As the conductive resin composition, it is preferable to use a composition containing a fluorine-containing compound or a silicone compound.

  Examples of the fluorine-containing compound include a fluorine-containing monomer, a fluorine-containing silane coupling agent, a fluorine-containing surfactant, and a fluorine-containing polymer.

Examples of the fluorine-containing monomer include a fluoroalkyl group-substituted vinyl monomer and a fluoroalkyl group-substituted ring-opening polymerizable monomer.
Examples of the fluoroalkyl group-substituted vinyl monomer include fluoroalkyl group-substituted (meth) acrylates, fluoroalkyl group-substituted (meth) acrylamides, fluoroalkyl group-substituted vinyl ethers, and fluoroalkyl group-substituted styrenes.

  Examples of the fluoroalkyl group-substituted ring-opening polymerizable monomer include fluoroalkyl group-substituted epoxy compounds, fluoroalkyl group-substituted oxetane compounds, and fluoroalkyl group-substituted oxazoline compounds.

  Fluorine-containing silane coupling agents include 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriacetoxysilane, dimethyl-3,3,3-trifluoropropylmethoxysilane, Examples include decafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane.

  Examples of the fluorine-containing surfactant include a fluoroalkyl group-containing anionic surfactant and a fluoroalkyl group-containing cationic surfactant.

  Fluorine-containing polymers include polymers of fluoroalkyl group-containing monomers, copolymers of fluoroalkyl group-containing monomers and poly (oxyalkylene) group-containing monomers, and copolymers of fluoroalkyl group-containing monomers and crosslinking reactive group-containing monomers. A polymer etc. are mentioned. The fluorine-containing polymer may be a copolymer with another copolymerizable monomer.

Examples of the silicone compound include (meth) acrylic acid-modified silicone, silicone resin, silicone silane coupling agent and the like.
Examples of the (meth) acrylic acid-modified silicone include silicone (di) (meth) acrylate, and examples include silicone diacrylates “x-22-164” and “x-22-1602” manufactured by Shin-Etsu Chemical Co., Ltd. Preferably used.

Hydrophilic material:
When the transparent film is required to have hydrophilicity (specifically, the water contact angle of the surface of the fine uneven structure of the cured resin layer is 25 ° or less), active energy ray curing that can form a hydrophilic material As the conductive resin composition, it is preferable to use a composition containing at least a hydrophilic monomer. Further, from the viewpoint of imparting scratch resistance and water resistance, an active energy ray-curable resin composition containing a cross-linkable polyfunctional monomer is more preferable. In addition, the same (namely, hydrophilic polyfunctional monomer) may be sufficient as the polyfunctional monomer which can be bridge | crosslinked with a hydrophilic monomer. Furthermore, the active energy ray-curable resin composition may contain other monomers.

  The active energy ray-curable resin composition capable of forming a hydrophilic material includes a tetrafunctional or higher polyfunctional (meth) acrylate, a bifunctional or higher hydrophilic (meth) acrylate, and a monofunctional monomer as necessary. More preferably, the composition is used.

Examples of the tetrafunctional or higher polyfunctional (meth) acrylate include ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol ethoxytetra (meth) acrylate, dipentaerythritol hydroxypenta (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, succinic acid / trimethylolethane / acrylic acid molar mixture 1: 2: 4 condensation reaction mixture, urethane acrylates (manufactured by Daicel-Cytec: EBECRYL220, EBECRYL1290K, EBECRYL1290K, EBECRYL5129, EBECRYL8210, EBECRYL 8301, KRM 8200), polyether acrylates (manufactured by Daicel-Cytec: EBEC) YL81), modified epoxy acrylates (manufactured by Daicel-Cytec: EBECRYL3416), polyester acrylates (manufactured by Daicel-Cytech: EBECRYL450, EBECRYL657, EBECRYL800, EBECRYL810, EBECRYL8111, EBECRYL81L, EBECRYL81L It is done. These may be used alone or in combination of two or more.
The polyfunctional (meth) acrylate having 4 or more functional groups is more preferably a polyfunctional (meth) acrylate having 5 or more functional groups.

  The content of the tetrafunctional or higher polyfunctional (meth) acrylate is preferably 10 to 50% by mass in 100% by mass of the polymerizable compound, and more preferably 20 to 50% by mass from the viewpoint of water resistance and chemical resistance. 30-50 mass% is especially preferable. When the content of the tetrafunctional or higher polyfunctional (meth) acrylate is 10% by mass or more, the elastic modulus is increased and the scratch resistance is improved. If the ratio of the tetrafunctional or higher polyfunctional (meth) acrylate is 50% by mass or less, small cracks are hardly formed on the surface, and the appearance is hardly deteriorated.

Long-chains such as Aronix M-240, Aronix M260 (manufactured by Toagosei Co., Ltd.), NK ester AT-20E, NK ester ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.) Examples thereof include polyfunctional acrylates having polyethylene glycol and polyethylene glycol dimethacrylate. These may be used alone or in combination of two or more.
In the polyethylene glycol dimethacrylate, the total of the average repeating units of the polyethylene glycol chain present in one molecule is preferably 6 to 40, more preferably 9 to 30, and particularly preferably 12 to 20. If the average repeating unit of the polyethylene glycol chain is 6 or more, the hydrophilicity is sufficient and the antifouling property is improved. When the average repeating unit of the polyethylene glycol chain is 40 or less, the compatibility with a polyfunctional (meth) acrylate having 4 or more functionalities is improved, and the active energy ray-curable resin composition is hardly separated.

  30-100 mass% is preferable in 100 mass% of polymeric compounds, and, as for content of bifunctional or more hydrophilic (meth) acrylate, 40-70 mass% is more preferable. If content of bifunctional or more hydrophilic (meth) acrylate is 30 mass% or more, hydrophilicity will become sufficient and antifouling property will improve. When the content of the bifunctional or higher hydrophilic (meth) acrylate is 80% by mass or less, the elastic modulus is increased and the scratch resistance is improved.

As the monofunctional monomer, a hydrophilic monofunctional monomer is preferable.
Examples of hydrophilic monofunctional monomers include monofunctional (meth) acrylates and hydroxyalkyl (meth) acrylates having a polyethylene glycol chain in the ester group such as M-20G, M-90G, and M-230G (manufactured by Shin-Nakamura Chemical Co., Ltd.). And cationic monomers such as monofunctional (meth) acrylates having a hydroxyl group in the ester group, monofunctional acrylamides, methacrylamide propyltrimethylammonium methyl sulfate, methacryloyloxyethyltrimethylammonium methyl sulfate, and the like.
Further, as the monofunctional monomer, a viscosity modifier such as acryloylmorpholine or vinylpyrrolidone, an adhesion improver such as acryloyl isocyanate for improving the adhesion to the article body, or the like may be used.

  The content of the monofunctional monomer is preferably 0 to 20% by mass and more preferably 5 to 15% by mass in 100% by mass of the polymerizable compound. By using a monofunctional monomer, the adhesion between the substrate and the cured resin layer is improved. If the content of the monofunctional monomer is 20% by mass or less, antifouling property or scratch resistance can be obtained without a shortage of polyfunctional (meth) acrylate having 4 or more functional groups or hydrophilic (meth) acrylate having 2 or more functional groups. Fully express.

  The monofunctional monomer may be blended in an active energy ray-curable resin composition as a low-polymerization polymer obtained by (co) polymerizing one or two or more of 0 to 35% by mass in 100% by mass of the polymerizable compound. Good. As the polymer having a low degree of polymerization, 40/40 of monofunctional (meth) acrylates having a polyethylene glycol chain in an ester group such as M-230G (manufactured by Shin-Nakamura Chemical Co., Ltd.) and methacrylamide propyltrimethylammonium methyl sulfate 60 copolymerization oligomer (manufactured by MRC Unitech Co., Ltd., MG polymer).

<< Viscosity >>
The viscosity of the active energy ray curable resin composition with a rotary B-type viscometer at 25 ° C. is that the active energy ray curable resin composition can be sufficiently supplied to the details of the inverted fine uneven structure of the mold. It is preferably 10 Pa · s or less, more preferably 5 Pa · s or less, and particularly preferably 2 Pa · s or less. If the viscosity at 25 ° C. of the active energy ray-curable resin composition is 10 Pa · s or less, the followability of the active energy ray-curable resin composition to the inversion fine uneven structure of the mold becomes good, and the inversion fine uneven structure. Can be transferred more accurately. Moreover, when supplying to the surface of a metal mold | die, you may heat beforehand and may reduce a viscosity.

(Active energy rays)
Examples of active energy rays include visible light, ultraviolet rays, electron beams, plasma, and heat rays (infrared rays and the like). Among these, ultraviolet rays are preferable.
Examples of the lamp that irradiates ultraviolet rays include a chemical lamp, a high-pressure mercury lamp, a metal halide lamp, an electrodeless UV lamp (manufactured by Fusion UV Systems), and a UV-LED lamp. Moreover, you may use together hardening by a heat | fever.

What is necessary is just to determine the irradiation amount of an ultraviolet-ray according to the absorption wavelength and content of a polymerization initiator contained in an active energy ray curable resin composition. Normally, the integrated quantity of ultraviolet light is 100~10000mJ / cm ^2, preferably ^{100~8000mJ / cm 2, 400~6000mJ / cm} 2 is more preferable. When the cumulative amount of ultraviolet light is 100 mJ / cm ² or more, the active energy ray-curable resin composition can be sufficiently cured. If the integrated light quantity of ultraviolet rays is 10,000 mJ / cm ² or less, deterioration of the substrate can be suppressed.
Moreover, it is preferable to suppress the irradiation intensity of ultraviolet rays to an output that does not cause deterioration of the base material.

"Transparent film"
5, 6, and 7 show examples of transparent films 40, 40 ′, and 40 ″ obtained by the transparent film manufacturing method of the present invention, respectively.
Each transparent film 40, 40 ′, 40 ″ is a cured resin layer having a fine concavo-convex structure in which a reverse fine concavo-convex structure of a mold is transferred on the surface of a base material (base film) 42 in a relationship between a key and a keyhole. 44 is formed.
As the base material 42, the base material illustrated previously in description of process (II) is mentioned.

The cured resin layer 44 is a film made of a cured product of the active energy ray-curable resin composition described above, and has a fine uneven structure on the surface.
The fine concavo-convex structure on the surface of the transparent film 40 when an anodized alumina mold is used is formed by transferring the inverted fine concavo-convex structure on the surface of the anodized alumina, and the active energy ray-curable resin composition It has the some convex part 46 which consists of hardened | cured material of a thing.

  As the fine concavo-convex structure, a so-called moth-eye structure in which a plurality of protrusions (convex portions) having a substantially conical shape or a pyramid shape are arranged is preferable. It is known that the moth-eye structure in which the distance between the protrusions is less than or equal to the wavelength of visible light is an effective anti-reflection measure by continuously increasing the refractive index from the refractive index of air to the refractive index of the material. It has been.

  The average interval between the convex portions is not more than the wavelength of visible light, that is, not more than 400 nm. When the protrusions are formed using a mold of anodized alumina, the average distance between the convex portions is about 100 to 200 nm, and therefore 250 nm or less is particularly preferable.

The average interval between the convex portions is preferably 20 nm or more from the viewpoint of easy formation of the convex portions.
The average interval between the convex portions was measured by measuring 10 points or 50 points between the adjacent convex portions (distance from the center of the convex portion to the center of the adjacent convex portion) by electron microscope observation, and averaged these values. Is.

When the average interval is 100 nm, the height of the convex portion is preferably 80 to 500 nm, more preferably 120 to 400 nm, and particularly preferably 150 to 300 nm. If the height of the protrusion is 80 nm or more, the reflectance is sufficiently low and the wavelength dependence of the reflectance is small. If the height of a convex part is 500 nm or less, the scratch resistance of a convex part will become favorable.
The height of the convex portion is a value obtained by measuring the distance between the top of the convex portion and the bottom of the concave portion existing between the convex portions when observed with an electron microscope at a magnification of 30000 times.

The aspect ratio of the convex portion (height of the convex portion / average interval between the convex portions) is preferably 0.8 to 5.0, more preferably 1.2 to 4.0, and 1.5 to 3.0. Particularly preferred. When the aspect ratio of the convex portion is 1.0 or more, the reflectance is not sufficiently low, and the wavelength dependency of the reflectance is small.
If the aspect ratio of the convex portion is 5.0 or less, the scratch resistance of the convex portion is good.

  The shape of the convex part is a shape in which the convex cross-sectional area in the direction perpendicular to the height direction continuously increases in the depth direction from the outermost surface, for example, the cross-sectional shape in the height direction of the convex part is a triangle, trapezoid, A bell-shaped shape is preferred.

  The difference between the refractive index of the cured resin layer 44 and the refractive index of the substrate 42 is preferably 0.20 or less, more preferably 0.10 or less, and particularly preferably 0.05 or less. When the refractive index difference is 0.20 or less, reflection at the interface between the cured resin layer 44 and the base material 42 is suppressed.

By the way, when the surface has a fine concavo-convex structure, if the surface is made of a hydrophobic material, super water repellency can be obtained by the lotus effect, and if the surface is made of a hydrophilic material, it is super hydrophilic. Is known to be obtained.
When the material of the cured resin layer 44 is the hydrophobic material described above, the water contact angle on the surface of the fine uneven structure is preferably 90 ° or more, more preferably 110 ° or more, and particularly preferably 120 ° or more. If the water contact angle is 90 ° or more, water stains are less likely to adhere, so that sufficient antifouling properties are exhibited. Moreover, since water does not adhere easily, anti-icing can be expected.
In order to set the water contact angle on the surface of the fine uneven structure of the cured resin layer 44 to 90 ° or more, an active energy ray-curable resin composition containing the hydrophobic material described above may be used.

On the other hand, when the material of the cured resin layer 44 is the above-described hydrophilic material, the water contact angle on the surface of the fine uneven structure is preferably 25 ° or less, more preferably 23 ° or less, and particularly preferably 21 ° or less. If the water contact angle is 25 ° or less, the dirt adhering to the surface is washed away with water and oil dirt is less likely to adhere, so that sufficient antifouling properties are exhibited. The water contact angle is preferably 3 ° or more from the viewpoint of suppressing the deformation of the fine concavo-convex structure due to water absorption of the cured resin layer 44 and the accompanying increase in reflectance.
In order to set the water contact angle of the surface of the fine uneven structure of the cured resin layer 44 to 25 ° or less, an active energy ray-curable resin composition containing the hydrophilic material described above may be used.

The transparent film 40 shown in FIG. 5 and the transparent film 40 ′ shown in FIG. 6 are the surfaces of the base material (base film) 42 sandwiched between the first regions 43 and 43 ′ at both end portions by the above-described steps. In addition, a cured resin layer 44 having a fine concavo-convex structure in which the inverted fine concavo-convex structure of the mold is transferred in a relationship between a key and a keyhole is formed.
In the transparent film 40 shown in FIG. 5, the thickness of the cured resin layer 44 in the second region 47 is equal to or less than the average height of the convex portions in the first region 43. For this reason, in the transparent film 40, blocking of the base film 42 can be prevented, and the cured resin layer 44 can be protected when rolled after shaping.
In the transparent film 40 ′ shown in FIG. 6, the thickness of the cured resin layer 44 is larger than the average height of the convex portions of the first region 43 ′. For this reason, in transparent film 40 ', the base film 42 can be prevented from being blocked, and the mold can be damaged and the transfer can be prevented from being lost during shaping.

The transparent film 40 ″ shown in FIG. 7 is according to another embodiment of the present invention, and is opposite to the back surface of the base film 42, that is, the surface on which the cured resin layer 44 is provided on the base film 42. The convex portion of the first region 43 ″ is provided on the side surface. In the transparent film 40 ″, the thickness of the cured resin layer 44 is equal to or less than the average height of the convex portions of the first region 43 ″. Even in such a transparent film 40 ″, blocking of the base film 42 can be prevented. Further, when the transparent film 40 ″ is rolled after shaping, the overlapping transparent films 40 ″ have a relationship as shown in FIG. Since the thickness of the cured resin layer 44 is equal to or less than the average height of the convex portions of the first region 43 ″, the first region 43 ″ provided on the back surface of the upper transparent film 40 ″. The convex portion defines the distance from the surface of the lower transparent film 40 ″, whereby the upper surface of the cured resin film 44 and the upper transparent film 40 ″ provided on the surface of the lower transparent film 40 ″. The cured resin layer 44 can be protected even when the transparent film 40 ″ is rolled.
In the transparent form 40 ″ shown in FIG. 7, the cured resin layer 44 on the front surface has a positional relationship such that it is sandwiched between the first regions 43 ″ on the back surface in the width direction. Since the resin layer 44 and the first region 43 ″ are provided on different surfaces, respectively, when the width of the cured resin layer 44 on the surface is increased and rolled, the first transparent film 40 ″ that overlaps the first layer 43 ″. You may make it contact one part or all part of the convex part of the area | region 43 of this.

<Application>
Applications of transparent films include antireflective articles, antifogging articles, antifouling articles, water repellent articles, and more specifically, antireflection for displays, automobile meter covers, automobile mirrors, automobile windows, organic or inorganic electro Examples include a luminescence light extraction efficiency improving member, a solar cell member, an optical waveguide, a relief hologram, a lens, a polarization separation element, and a cell culture sheet.

  For example, when a transparent film is used as an antireflection film, the surface of an object such as an image display device (liquid crystal display device, plasma display panel, electroluminescence display, cathode tube display device, etc.), lens, show window, spectacle lens, etc. In addition, a transparent film is applied.

In addition, when the part where the transparent film is pasted is a three-dimensional shape, an article having a fine concavo-convex structure on the surface is manufactured in advance using a substrate having a shape corresponding thereto, and this is pasted on a predetermined part of the object. You can attach it.
When the object is an image display device, not only the surface thereof, but also a transparent film may be attached to the front plate, or the front plate itself is composed of an article having a fine uneven structure on the surface. May be.

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

<Manufacture of molds>
(Production example)
According to the following process, the roll-shaped metal mold | die which has the inversion fine concavo-convex structure below the wavelength of visible light on the surface was manufactured.

pre-process:
As the aluminum substrate, roll aluminum having a purity of aluminum of 99.99% was used. In addition, as a polishing body, a polyester non-woven fabric and a foamed polyurethane suede polishing pad were used to make a mirror surface.

Step (a):
The aluminum substrate surface-treated in the previous step was anodized for 6 hours in a 0.3 M oxalic acid aqueous solution at a direct current of 40 V and a temperature of 16 ° C. to form an oxide film on the surface of the aluminum substrate.

Step (b):
The aluminum base material on which the oxide film was formed in the step (a) was immersed in a 6% by mass phosphoric acid / 1.8% by mass chromic acid mixed aqueous solution for 6 hours to remove the entire oxide film.

Step (c):
The aluminum substrate after the step (b) was anodized for 20 seconds in a 0.3 M oxalic acid aqueous solution under the conditions of a direct current of 40 V and a temperature of 16 ° C. to form an oxide film on the surface of the aluminum substrate.

Step (d):
The aluminum base material on which the oxide film was formed in the step (c) was immersed in 5% by mass phosphoric acid at 32 ° C. for 8 minutes to carry out pore size expansion treatment.

Step (e):
The aluminum substrate after the step (d) was anodized in a 0.3 M oxalic acid aqueous solution at a direct current of 40 V and a temperature of 16 ° C. for 20 seconds.

Step (f):
The step (d) and the step (e) are repeated four times in total, and finally the step (d) is performed, and anodized alumina having substantially conical pores with an average interval of 100 nm and a depth of 200 nm is the surface. A roll-shaped mold formed in the above was obtained.

Steps (g) to (l):
The obtained mold was washed with deionized water, and then water on the surface was removed by air blow.
Next, after immersing the mold in a 0.1% by weight diluted solution of TDP-8 (manufactured by Nikko Chemicals) for 10 minutes, the mold was slowly pulled up from the diluted solution, and the mold was air-dried overnight. A roll-shaped mold surface-treated with an external release agent was obtained.

<Measurement of mold pores>
A part of the mold with the oxide film formed on the surface is cut, platinum is deposited on the surface and cross section for 1 minute, and accelerated using a field emission scanning electron microscope (JEOL Ltd., “JSM-7400F”). Observe the surface under a voltage of 3.00 kV, measure the pore spacing (distance from the center of the pore to the center of the adjacent pore) at 10 points, and use the average value as the average spacing between adjacent pores. It was.
Similarly, the longitudinal section of the mold was observed in the same manner, and the distance between the bottom of the pores and the top of the convex portions existing between the pores was measured at 10 points, and the average value was measured. The average depth. The shape of the pores was confirmed.

<Preparation of active energy ray-curable resin composition>
Each component was mixed according to the following compounding composition, and the active energy ray-curable resin composition was prepared.

(Composition composition of active energy ray-curable resin composition A)
-Trimethylolethane / acrylic acid / succinic anhydride condensation reaction product: 70 parts by mass,
Polyethylene glycol diacrylate (manufactured by Toagosei Co., Ltd., “Aronix M260”): 20 parts by mass
2-hydroxyethyl acrylate: 3 parts by mass
Methyl acrylate: 7 parts by mass
(Poly) oxyalkylene alkyl phosphate ester compound (manufactured by Accel Corp., “Mold with INT-1856”): 0.3 part by mass,
1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Japan, “Irgacure 184”): 1 part by mass,
Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by BASF Japan, “Irgacure 819”): 0.1 part by mass.

(Composition composition of active energy ray-curable resin composition B)
Dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., “Kayarad DPHA”): 20 parts by mass,
Pentaerythritol triacrylate (Daiichi Kogyo Seiyaku Co., Ltd., “PET-3”): 20 parts by mass
EO-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., “Kayarad DPEA-12”): 30 parts by mass
Polyethylene glycol diacrylate (manufactured by Toagosei Co., Ltd., “Aronix M260”): 30 parts by mass
(Poly) oxyalkylene alkyl phosphate ester compound (manufactured by Accel Corp., “Mold with INT-1856”): 0.3 part by mass,
1-hydroxycyclohexyl phenyl ketone (manufactured by BASF Japan, “Irgacure 184”): 1 part by mass,
Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by BASF Japan, “Irgacure 819”): 0.1 part by mass.

<Measurement of height and width of first region of base film>
(Measurement of average height H)
The average height H of the convex portions of the first region formed at both ends of the base film is measured 10 times at a magnification of 10 times using a shape measurement laser microscope (manufactured by KEYENCE, VK-X100). Calculated as an average.
(Measurement of average width W)
The average width W of each of the first regions formed at both ends of the base film was measured at 10 locations using a metal scale and calculated as an average.

<Measurement of haze>
A transparent film is pasted on a slide glass (manufactured by Matsunaga Glass Industrial Co., Ltd., “S9112”) via a non-carrier film (manufactured by Lintec Co., Ltd., “OPTERIA MO-3006C”), and a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., “NDH2000”). )) To measure the transmittance.

<Appearance evaluation of single wafer>
(Optical distortion defect)
Appearance evaluation of optical distortion uses an LED light (“DOP-XRE301” manufactured by Asahi Denki Co., Ltd.), visually observes a transparent film in a dark room, and determines the number of optical distortion defects having a diameter of about 1 to 2 mm. Measured and evaluated according to the following criteria.
○: Occurrence frequency of appearance defects 0 to 3 per 0.1 m ² Δ: Occurrence frequency of appearance defects 4 to 10 per 0.1 m ² ×: Generation frequency of appearance defects 11 or more per 0.1 m ² (Whitening)
The appearance of whitening is evaluated by using an LED light (“DOP-XRE301” manufactured by Asahi Denki Co., Ltd.) and visually observing the transparent film in a dark room. Evaluation based on the criteria.
○: No whitening is observed (over 95% as a whole)
Δ: Partial whitening is observed (75-94%)
X: Whitening is recognized (74% or less)

<Appearance evaluation of roll-shaped transparent film>
The appearance of the roll-shaped transparent film was evaluated by visually observing the roll film that was produced and wound up, and evaluated whether there was any wrinkling, winding, or winding deviation based on the following criteria.
○: Wrinkles, winding-up, and winding deviation are not recognized Δ: Some wrinkles, winding-up, winding-up deviation is recognized ×: Wrinkles, winding-up, winding-up deviation is recognized

<Measurement of film thickness>
The film thickness of the second region was measured at 10 points in the width direction using a micrometer (manufactured by Mitutoyo Corporation, model: ID-F125), and calculated as an average.

<Measurement of warpage>
For the measurement of warpage, a long transparent film was cut to 500 mm, the heights of four corners were measured using a gold scale, and the average was calculated.
○: Less than 5 mm Δ: Less than 20 mm ×: 20 mm or more

"Example 1"
The transparent film was continuously manufactured as follows using the manufacturing apparatus shown in FIG. In addition, as the roll-shaped mold 20 and the active energy ray-curable resin composition 24, the above-described die and the active energy ray-curable resin composition A were used. As the base film 42, a base material in which a first region was formed at both ends of a polyethylene terephthalate film (Toyobo Co., Ltd., “Cosmo Shine A-4300”, thickness: 75 μm) was used. In the production of the transparent film, the average height H and the average width W of the convex portions of the first region of the used base film were measured. The results are shown in Table 1.

While the belt-shaped base film 42 is moved along the surface of the roll-shaped mold 20 in synchronization with the rotation of the roll-shaped mold 20, between the roll-shaped mold 20 and the base film 42 from the tank 22. An active energy ray-curable resin composition 24 was supplied.
The active energy ray-curable resin composition 24 is irradiated from the base film 42 side with ultraviolet light with an integrated light quantity of 1000 mJ / cm ² using an electrodeless UV lamp (manufactured by Fusion UV Systems, “Light Hammer 6”). Then, the cured resin layer 44 was formed in the second region on the surface of the base film 42 by curing the active energy ray-curable resin composition 24.
A transparent film was continuously produced by peeling the base film 42 having the cured resin layer 44 formed on the surface from the roll mold 20 by the peeling roll 32.
When the transparent film was manufactured 200 m, the movement of the base film 42 was stopped. About the transparent film obtained just before the stop, haze, film thickness, and warp were measured, and the appearance of the single wafer and the appearance of the roll were evaluated. These results are shown in Table 3.

"Example 2"
A transparent film was continuously produced in the same manner as in Example 1 except that the base film B was used as the base film 42 and the active energy ray curable resin composition B was used as the active energy ray curable resin composition. About the transparent film at the time of manufacturing 200m, haze, a film thickness, and curvature were measured, and the external appearance evaluation of the sheet | seat and the roll shape were performed. The results of evaluation as a transparent film are shown in Table 3.

"Comparative Examples 1-5"
A transparent film was continuously produced in the same manner as in Example 1 except that the base film 42 and the active energy ray-curable resin composition shown in Table 2 were used. About the transparent film at the time of manufacturing 200m, haze, a film thickness, and curvature were measured, and the external appearance evaluation of the sheet | seat and the roll shape were performed. The results of evaluation as a transparent film are shown in Table 3.

As is clear from the results in Table 3, in Examples 1 and 2, the average height of the protrusions in the first region (first region average height) and the thickness of the second region (second The difference in area average height) is within a range of ± 25 μm (that is, the average height of the protrusions of the first area is within the range of the film thickness of the second area ± 25 μm), and the protrusions of the first area Since the ratio W / H of the average height H to the average width W is 200 to 5000, the appearance of the roll film is good, and further optical distortion defects in the second region of the single wafer transparent film, whitening, There was no transfer omission and a good transparent film was obtained. By having the unevenness | corrugation of the 1st area | region provided in the both ends of the base film, it was possible to suppress blocking and optical distortion of the roll film, whitening of the fine unevenness structure of the second area, and transfer omission.
On the other hand, in Comparative Example 1, the difference between the average height of the protrusions in the first region (first region average height) and the thickness of the second region (second region average height) is 25 μm. Since the height of the convex part of the 1st field was so high that it exceeded, and the film thickness of the 2nd field was thin, curvature occurred. In Comparative Example 2, since the average height H of the convex portions of the first region of the used base film was high and the average width W of each of the first regions was narrow, blocking and wrinkles occurred, and Whitening and transfer loss occurred in the area 2. In Comparative Example 3, since the average height of the convex portions in the first region was lower than the average width W of the first region, an optical distortion defect occurred, and whitening and omission of transfer occurred. In Comparative Example 4, since there was no unevenness in the first region, there was a warp. In addition, an optical distortion defect due to contamination was generated.

Usually, when producing a transparent film having a fine uneven structure on the surface that is less than or equal to the wavelength of visible light, winding or film deformation is likely to occur at the stage of winding the film in a roll shape, and the transferred fine uneven structure is white. And haze may increase. In particular, when the production speed is increased, when the smoothness of the base film is high, or when the aspect ratio of the fine concavo-convex structure corresponding to the second region is high, when a flexible active energy ray-curable resin composition is used Is likely to cause whitening of the transparent film.
As described above, these are dealt with by knurling, but when the knurled height is low, the optical distortion defect may not be suppressed or the fine concavo-convex structure may be whitened.

However, the transparent film of the present invention has a first region provided at both end portions in the width direction of the base film, and irregularities below the wavelength of visible light formed between the first regions. The presence of the second region can suppress the occurrence of optical distortion defects, wrinkles, whitening, and transfer omission.
Therefore, according to the transparent film of the present invention, it is possible to obtain a transparent film that suppresses optical distortion defects and wrinkles and is free of whitening and transfer omission.

The method for producing a transparent film of the present invention is useful for efficient mass production of transparent films such as antireflection articles, antifogging articles, antifouling articles, water repellent articles, and cell culture sheets.
The transparent film obtained by the present invention is suitable as an antireflection article, an antifogging article, an antifouling article, a water repellent article, a cell culture sheet, and the like.

DESCRIPTION OF SYMBOLS 10 Aluminum base material 12 Pore 14 Oxide film 16 Pore generation | occurrence | production point 18 Mold 20 Roll-shaped mold 22 Tank 24 Active energy ray-curable resin composition 26 Pneumatic cylinder 28 Nip roll 30 Active energy ray irradiation apparatus 32 Peeling roll 40, 40 ', 40''transparent film 42 substrate (substrate film)
43, 43 ′, 43 ″ First region 44 Cured resin layer 46 Multiple convex portions 47 Second region

Claims (2)

A first region in which a plurality of convex portions are formed at both ends in the width direction of the long substrate film at a period equal to or longer than the wavelength of the visible light region;
A transparent film having a second region provided with a layer having a fine concavo-convex structure consisting of a plurality of convex portions formed at a period of a wavelength equal to or less than the wavelength of the visible light region on the surface,
The second region is formed between the first regions,
The average height of the protrusions in the first region is within the range of the film thickness of the layer in the second region ± 25 μm,
The ratio W / H of the width W of each said 1st area | region and the average height H of the convex part of the said 1st area | region is 200-5000. The transparent film characterized by the above-mentioned. It is a manufacturing method of the transparent film of Claim 1, Comprising:
(I) An active energy ray-curable resin composition is formed on the base film in which a plurality of convex portions are formed at both ends in the width direction of the long base film at a period equal to or longer than the wavelength of the visible light region. Applying step;
(II) The active energy ray-curable resin composition applied to the transparent film is pressed against a transfer mold and irradiated with active energy rays to cure the active energy ray-curable resin composition, and the transfer gold A forming step of transferring the uneven shape formed on the mold to the surface of the active energy ray-curable resin, and forming the fine uneven structure on the base film;
(III) comprising a step of separating the transparent film and the mold,
A method for producing a transparent film.

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