CN102666055B - Performance Evaluation Method of Organic Release Agent, Method of Manufacturing Mold, and Method of Manufacturing Transparent Film with Fine Concave-Convex Structure on Surface - Google Patents

Abstract

The present invention relates to a method for manufacturing a mold comprising the following steps (I) to (III): (I) a step of preparing a mold body having a fine concavo-convex structure formed on its surface; (II) a step of evaluating the performance of an organic release agent according to a method for evaluating the performance of an organic release agent; and (III) a step of treating the surface of the mold body prepared in the above step (I) with the organic release agent judged to have good performance in the above step (II); wherein the method for evaluating the performance of the organic release agent comprises mixing the organic release agent with a test organic solvent and judging the performance of the organic release agent by the solubility of the organic release agent in the test organic solvent.

Description

Performance Evaluation Method of Organic Release Agent, Method of Manufacturing Mold, and Method of Manufacturing Transparent Film with Fine Concave-Convex Structure on Surface

technical field

The present invention relates to a method for evaluating the performance of an organic mold release agent, a method for manufacturing a mold, and a method for manufacturing a transparent film having a fine concave-convex structure on the surface.

this application claims priority based on Japanese Patent Application No. 2009-291775 for which it applied to Japan on December 24, 2009, The content is used here.

Background technique

In recent years, it has been known that an article having a fine concave-convex structure with a period equal to or less than the wavelength of visible light on the surface exhibits antireflection effects, lotus effects, and the like. In particular, it is known that a fine concavo-convex structure called a moth-eye structure constitutes an effective anti-reflection means due to the continuous increase in the refractive index from that of air to that of the material of the article.

As a method for producing a transparent film having a fine uneven structure on the surface, a method of transferring the fine uneven structure on the surface of a mold to the surface of a base film by optical nanoimprinting, thermal nanoimprinting, or the like is known.

As an optical nanoimprint method, for example, a method including the following steps (I) to (III) is known (for example, Patent Document 1):

(I) A step of sandwiching an ultraviolet curable resin composition between a mold having an inverted structure having a fine uneven structure on the surface and a base film constituting the main body of the transparent film;

(II) A step of irradiating ultraviolet rays to the ultraviolet curable resin composition to cure the above ultraviolet curable resin composition to form a cured film having a fine uneven structure to obtain a transparent film; and

(III) A step of separating the mold from the transparent film.

The surface of the mold is usually treated with an organic mold release agent. However, the organic mold release agent used for the treatment of the surface of the mold may deteriorate due to repeated use in the surface treatment of the mold or standing for a long period of time. A mold surface-treated with a deteriorated organic mold release agent may have insufficient surface mold release properties, and as a result, it may be difficult to stably produce a transparent film.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2007-326367

Contents of the invention

The problem to be solved by the invention

The present invention provides a method for evaluating the performance of an organic mold release agent that can easily judge performance in a short time; a method that can produce a mold with sufficient surface releasability; and a method that can stably produce a transparent film with a fine uneven structure on the surface method.

solutions to problems

The method for manufacturing a mold according to the first embodiment of the present invention is characterized in that it has the following steps (I) to (III):

(1) The process of making the mold body with a fine concave-convex structure formed on the surface;

(II) A step of evaluating the performance of the organic mold release agent by the following performance evaluation method of the organic mold release agent; and,

(III) A step of treating the surface of the mold body prepared in the above step (I) with an organic mold release agent judged to have good performance in the above step (II);

The method for evaluating the performance of the organic mold release agent is to mix the organic mold release agent with the organic solvent for the test, and judge the organic mold release agent by the solubility of the organic mold release agent in the organic solvent for the test. The performance of the method is good or bad.

The above step (I) is preferably a step of forming the anodized alumina having a plurality of pores on the surface of the aluminum substrate to produce the mold main body.

The above-mentioned organic mold release agent is preferably a fluorine compound having a hydrolyzable silyl group or silanol group.

The dielectric constant of the above-mentioned test organic solvent is preferably 22-40.

The above-mentioned test organic solvent is preferably ethanol or N,N-dimethylformamide.

Preferably, the solubility of the organic mold release agent in the test organic solvent is judged by the light transmittance of the mixture of the organic mold release agent and the test organic solvent.

The method for evaluating the performance of the organic mold release agent according to the second embodiment of the present invention is to mix the organic mold release agent with the organic solvent for the test, and determine the solubility of the organic mold release agent in the organic solvent for the test. A method for judging the performance of organic release agents.

It is preferable to dilute the above-mentioned organic release agent with an organic solvent for dilution in advance to form the above-mentioned release agent solution.

Preferably, the above-mentioned organic mold release agent is used to treat the surface of the mold main body having a fine uneven structure formed on the surface.

The method for producing a transparent film having a fine uneven structure on the surface according to the third embodiment of the present invention is characterized in that the fine uneven structure on the surface of the mold obtained by the method for producing the mold described in the first embodiment of the present invention is converted into Printed onto the surface of the substrate film.

The effect of the invention

According to the method for evaluating the performance of an organic mold release agent according to the second embodiment of the present invention, it is possible to easily determine whether the performance of an organic mold release agent is good or bad in a short time.

According to the method of manufacturing a mold according to the first embodiment of the present invention, a mold having sufficient surface releasability can be produced.

According to the method for producing a transparent film having a fine uneven structure on the surface according to the third embodiment of the present invention, a transparent film can be stably produced.

Description of drawings

FIG. 1 is a cross-sectional view showing the formation process of pores of anodized alumina.

FIG. 2 is a configuration diagram showing an example of an apparatus for manufacturing a transparent thin film having a fine uneven structure on its surface.

Fig. 3 is a cross-sectional view showing an example of a transparent film having a fine uneven structure on the surface.

Explanation of reference signs

10 aluminum substrate

12 pores

14 oxide film

18 mold body

20 dies

40 transparent film

42 base film

44 curing film

46 Convex

Detailed ways

In this specification, (meth)acrylate means acrylate or methacrylate. Transparency means that at least light with a wavelength of 400~1170nm is transmitted. In addition, active energy rays refer to visible rays, ultraviolet rays, electron beams, plasma, heat rays (infrared rays, etc.), and the like.

<Performance Evaluation Method of Organic Release Agent>

The performance evaluation method of the organic mold release agent according to the second embodiment of the present invention is to mix the organic mold release agent with the organic solvent for the test, and judge by the solubility of the organic mold release agent in the organic solvent for the test How to improve the performance of organic mold release agents.

An organic mold release agent may deteriorate due to repeated use or long-term storage for surface treatment of molds, and may fail to exhibit sufficient mold release properties. The inventors of the present invention found that the reason for this is that, in the case of a compound having a hydrolyzable silyl group, intermolecular condensation occurs, the reactivity with the mold main body decreases, and the adhesiveness decreases. However, deterioration of an organic mold release agent cannot be judged only by the appearance of an organic mold release agent. The presence or absence of intermolecular condensation can also be investigated by nuclear magnetic resonance spectroscopy, etc., but the measurement requires labor and time, and requires expensive equipment. Therefore, the present inventors focused on the deterioration of the organic mold release agent, that is, the increase in the molecular weight of the organic mold release agent due to intermolecular condensation, and the decrease in the solubility of the organic mold release agent in an organic solvent. the invention.

(Measure to judge)

The solubility of the degraded organic mold release agent in the organic solvent for a test was lowered, and it became cloudy. As a method of confirming the presence or absence of cloudiness, the method of measuring the light transmittance, the method of measuring light scattering, etc. are mentioned, and the method of measuring the light transmittance is preferable from the viewpoint of being able to measure easily in a short time. of.

When the solubility of the organic mold release agent in the test organic solvent is judged by the light transmittance of the mixture of the organic mold release agent and the test organic solvent, the threshold value of the light transmittance as a judgment standard can be determined as follows, for example :

(1) The light transmittance of the mixture of the organic release agent (unused product) and the test organic solvent before the surface treatment of the mold body was measured using a spectrophotometer. Next, using a mold surface-treated with an organic mold release agent (unused product), the transparent film described later was produced, and mold release properties were evaluated.

(2) Using a spectrophotometer, measure the light transmittance of the mixture of the organic mold release agent and the organic solvent for the test that have been subjected to surface treatment of the mold body once to multiple times. Next, a transparent film to be described later was produced using the mold surface-treated with the above-mentioned organic mold release agent, and mold release properties were evaluated.

(3) The operation of (2) above was repeated until the evaluation of mold releasability was judged to be impossible.

(4) Spectrum of light transmittance of a mixture of an organic mold release agent (unused product) and an organic solvent for testing before surface treatment of the mold body and an organic mold release agent judged to be unable to evaluate mold release properties ( Deteriorated product) and the spectrum of the light transmittance of the mixture of the organic solvent for the test were compared, and the light transmittance of the mixture of the organic mold release agent (deteriorated product) and the organic solvent for the test at the wavelength at which the difference in light transmittance was the largest was set set as the threshold.

The light transmittance was measured with a spectrophotometer. Specifically, what was obtained by mixing the following release agent solution and the organic solvent for the test at a volume ratio of 2/8 to 8/2 was used as a measurement solution. In addition, as a reference, a mixture in which the dilution solvent for the release agent solution and the organic solvent for the test were mixed in the above-mentioned volume ratio was used. As the measurement wavelength, an ultraviolet to visible region (for example, about 200 to 900 nm) is used.

(organic release agent)

Examples of organic mold release agents include silicone resins, fluororesins, and fluorine compounds, which have hydrolyzable silyl groups or silanol groups from the viewpoint of excellent mold release properties and excellent adhesion to molds. Fluorine compounds are preferred, and fluorine compounds having a hydrolyzable silyl group are particularly preferred. Commercially available products of fluorine compounds having a hydrolyzable silyl group include fluoroalkylsilane, KBM-7803 (manufactured by Shin-Etsu Chemical Co., Ltd.), "OPTOOL" series (manufactured by DAIKIN INDUSTRIES, Ltd.), Novec EGC-1720 (manufactured by Sumitomo 3M Co., Ltd.), etc.

(organic solvent for test)

As the organic solvent for the test, a solvent in which a difference in solubility (light transmittance when forming a mixture) was observed between a normal organic release agent and a deteriorated organic release agent was used. For example, when the polarity of the organic solvent for the test is too low, both are easily soluble, but when the polarity is too high, neither is easily soluble, and there is no difference in solubility (light transmittance when forming a mixture). Therefore, an organic solvent having moderate polarity (that is, a dielectric constant) is preferable as the test organic solvent. The dielectric constant of the organic solvent used in the test is preferably 10-70, more preferably 30-60, and most preferably 22-40.

As an organic solvent for the test, for fluorine compounds having hydrolyzable silyl groups or silanol groups, from the viewpoint of increasing the difference in solubility (light transmittance when forming a mixture) between normal fluorine compounds and degraded fluorine compounds, Ethanol [dielectric constant: 23.8 (25° C.)] and N,N-dimethylformamide [dielectric constant: 36.7 (25° C.)] are preferable, and N,N-dimethylformamide is particularly preferable.

The dielectric constant in the present invention is a relative permittivity when the dielectric constant of vacuum is set to 1, and a literature value ["Solvent Handbook", Kodansha Scientific Ltd., 1976, p. 734] is used.

(organic solvent for dilution)

Usually, when used for the surface treatment of the mold itself, the organic mold release agent is diluted with an organic solvent for dilution so that the surface of the mold body can be uniformly treated, and used as a mold release agent solution. Therefore, in the performance evaluation method of the organic type mold release agent of the present invention, it is preferable that the organic type mold release agent is actually used for the surface treatment of the mold main body, and is diluted with an organic solvent for dilution. evaluated in the state of the solution. The organic solvent for dilution is not particularly limited as long as it dissolves the organic release agent. When a fluorine compound having a hydrolyzable silyl group or silanol group is used as the organic release agent, a solvent with a low dielectric constant Preferable examples include hexane, chloroform, diethyl ether, tetrahydrofuran, dichloromethane, acetone, acetonitrile, N,N-dimethylformamide and the like. In particular, when using the "OPTOOL" series (manufactured by DAIKININDUSTRIES, Ltd.) as the organic release agent, it is preferable to use the fluorine-based organic solvent "DURASURF" series (manufactured by HARVES Co., Ltd.).

(specific example)

Hereinafter, the case where the organic release agent is a fluorine compound having a hydrolyzable silyl group ["OPTOOL" series, manufactured by DAIKIN INDUSTRIES, Ltd.] will be described in more detail as an example.

As an organic solvent for testing, from the viewpoint of increasing the difference in solubility (light transmittance when forming a mixture) between the normal "OPTOOL" series and the deteriorated "OPTOOL" series, N,N-Dimethylformamide is particularly preferred.

As the organic solvent for dilution, the fluorine-based organic solvent DURASURF HD-ZV (manufactured by HARVES Co., Ltd.) is preferable from the viewpoint of the solubility of the organic mold release agent.

When the concentration of "OPTOOL" series in the mixture of the release agent solution and the organic solvent for the test is too high or too low, it is difficult to express the poor solubility corresponding to the deterioration. Therefore, the mixing ratio of 0.1% by mass release agent solution to N,N-dimethylformamide obtained by diluting the "OPTOOL" series with DURASURF HD-ZV (release agent solution/N,N-dimethylformamide ) is preferably 2/8 to 8/2 (volume ratio), more preferably 4/6 to 6/4 (volume ratio), and particularly preferably 5/5 (volume ratio).

When a 0.1% by mass release agent solution of the "OPTOOL" series diluted with DURASURF HD-ZV is mixed with the same volume of N,N-dimethylformamide, even unused products are slightly cloudy, and the release properties The reduced deteriorated product was remarkably cloudy. The judgment of the performance of the above-mentioned release agent solution is carried out like this: preferably, according to the result of the embodiment described later, the light transmittance of the mixture under the wavelength 400nm that the light transmittance decreases sharply is more than 36% and then judged as good performance, More preferably, a light transmittance of 45% or more is judged as good performance.

(Effect)

In the performance evaluation method of the organic mold release agent according to the second embodiment of the present invention described above, the organic mold release agent is mixed with the organic solvent for the test, and the organic mold release agent is dissolved in the organic solvent for the test. The performance of the organic release agent can be judged according to the performance of the organic release agent, so the performance of the organic release agent can be easily judged in a short time.

Furthermore, since the performance of the organic mold release agent can be judged in advance, it is possible to avoid troubles such as deterioration of the mold releasability due to deterioration of the organic mold release agent after the production of the transparent film is started. In addition, organic mold release agents can be effectively used to the limit.

The performance evaluation method according to the second embodiment of the present invention is suitable for evaluating an organic release agent used when producing a transparent film using a mold having a fine uneven structure with pores formed at an average interval of 20 to 400 nm, which will be described later. It is especially suitable when pores are formed by anodic oxidation.

<Mold manufacturing method>

The manufacturing method of the mold of the first embodiment of the present invention has the following steps (I) to (III):

(1) The process of making the mold body with a fine concave-convex structure formed on the surface;

(II) A step of evaluating the performance of the organic mold release agent by the following performance evaluation method of the organic mold release agent; and,

(III) A step of treating the surface of the mold main body prepared in the above step (I) with an organic mold release agent judged to have good performance in the above step (II),

The performance evaluation method of the organic mold release agent is to mix the organic mold release agent with the organic solvent for the test, and judge the performance of the organic mold release agent by the solubility of the organic mold release agent in the organic solvent for the test. Methods with good or bad performance.

Among them, the performance evaluation method of the organic release agent according to the second embodiment of the present invention can be used as the performance evaluation method of the organic release agent according to the first embodiment of the present invention.

(Process (I))

In the step (I), a fine concavo-convex structure is formed on the surface of the base material to produce a mold main body.

Examples of the material of the substrate include metals (including metals having an oxide film formed on the surface), quartz, glass, resin, ceramics, and the like.

Examples of the shape of the substrate include a roll shape, a circular tube shape, a flat plate shape, a sheet shape, and the like.

As a method of manufacturing the mold main body, for example, the following method (I-1) or (I-2) can be mentioned, and the method (I-1) is particularly preferable from the viewpoint that the area can be increased and the production is simple.

(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 uneven structure on the surface of a substrate by photolithography.

As the method (I-1), a method having the following steps (a) to (e) is preferable.

(a) A step of anodizing an aluminum substrate at a constant voltage in an electrolytic solution to form an oxide film on the surface of the aluminum substrate.

(b) A step of removing the oxide film and forming anodized pore generation sites on the surface of the aluminum substrate.

(c) A step of anodizing the aluminum substrate again in an electrolytic solution to form pores at the pore generation points.

(d) A step of enlarging the diameter of the pores.

(e) After the above-mentioned step (d), a step of re-anodizing in an electrolytic solution.

(f) A step of repeating the steps (d) and (e) above to obtain a mold body in which anodized alumina having a plurality of fine pores is formed on the aluminum surface.

Process (a):

As shown in FIG. 1 , when an 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, a sheet shape, and the like.

In order to smooth the surface state, the aluminum substrate is preferably polished by mechanical polishing, cloth polishing, chemical polishing, electrolytic polishing (etching treatment), or the like. In addition, since the oil used adheres to the aluminum substrate when it is processed into a predetermined shape, it is preferable to degrease before anodizing.

The purity of aluminum is preferably 99% or higher, more preferably 99.5% or higher, and particularly preferably 99.8% or higher. When the purity of aluminum is low, during anodization, due to segregation of impurities, a concave-convex structure of a size that scatters visible light may be formed, and the regularity of pores obtained during anodization may decrease.

Examples of the electrolytic solution include sulfuric acid, oxalic acid, phosphoric acid, and the like.

When using oxalic acid as electrolyte:

The concentration of oxalic acid is preferably 0.7M 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 60V, anodized alumina having highly regular pores with a period of about 100 nm can be obtained. When the formation voltage is higher than this range or lower than this range, the regularity tends to decrease.

The temperature of the electrolytic solution is preferably 60°C or lower, more preferably 45°C or lower. When the temperature of the electrolytic solution exceeds 60° C., a so-called “burning” phenomenon occurs, and the pores are destroyed, or the surface dissolves, and the regularity of the pores is disturbed.

When using sulfuric acid as electrolyte:

The concentration of sulfuric acid is preferably 0.7M or less. When the concentration of sulfuric acid exceeds 0.7M, the current value becomes too high, and a constant voltage cannot be maintained.

When the formation voltage is 25~30V, anodized alumina having highly regular pores with a period of about 63nm can be obtained. The regularity tends to decrease when the formation voltage is higher or lower than this range.

The temperature of the electrolytic solution is preferably 30°C or lower, more preferably 20°C or lower. When the temperature of the electrolytic solution exceeds 30° C., a phenomenon called “burning” occurs, and the pores are destroyed, or the surface dissolves, and the regularity of the pores is disturbed.

Process (b):

As shown in FIG. 1 , the oxide film 14 is first removed to form anodized pore generation points 16 , thereby improving the regularity of the pores.

As a method of removing the oxide film, a method of dissolving and removing the oxide film in a solution that does not dissolve aluminum but selectively dissolves the oxide film can be mentioned. As such a solution, a chromic acid/phosphoric acid mixed liquid etc. are mentioned, for example.

Process (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 columnar pores 12 is formed.

Anodic oxidation can be performed under the same conditions as step (a). Extending the time of anodizing can obtain deep pores.

Process (d):

As shown in FIG. 1 , a process of enlarging the pore diameter of the pores 12 (hereinafter referred to as pore diameter enlarging process) is performed. The pore diameter enlarging treatment is a process of enlarging the pore diameters of the pores obtained by anodizing by immersing in a solution for dissolving the oxide film. As such a solution, for example, a phosphoric acid aqueous solution of about 5% by mass or the like may be mentioned.

The longer the pore diameter enlarging treatment time, the larger the pore diameter.

Process (e):

As shown in FIG. 1 , during re-anodization, the cylindrical pores 12 with a small diameter extending downward from the bottom of the cylindrical pores 12 are further formed.

Anodic oxidation can be performed under the same conditions as step (a). Long anodizing time can obtain deep pores.

Process (f):

As shown in FIG. 1 , when the pore diameter enlarging treatment in step (d) and the anodizing in step (e) are repeated, an oxide film having pores 12 whose diameters continuously decrease from the opening to the depth direction can be formed. 14. A mold main body 18 in which anodized aluminum oxide (porous aluminum oxide film (alumite, aluminum oxide film)) is formed on the surface of the aluminum substrate 10 can be obtained. Finally, it is preferable to end in step (d).

The number of repetitions is preferably 3 or more in total, and more preferably 5 or more. When the number of repetitions is 2 or less, since the pore size discontinuity decreases, the reflectance reduction effect of the moth-eye structure formed using anodized alumina having such pores is insufficient.

As the shape of the pores 12, substantially conical shapes, pyramidal shapes, cylindrical shapes, etc. can be mentioned, such as conical shapes, pyramidal shapes, etc., the pore cross-sectional area in the direction perpendicular to the depth direction is continuous from the outermost surface to the depth direction. A reduced shape is preferred.

The average interval of the pores 12 is equal to or less than the wavelength of visible light, that is, equal to or less than 400 nm. The average interval between pores 12 is preferably 20 nm or more.

The average interval between the fine holes 12 is to measure 50 intervals between the adjacent fine holes 12 (the distance from the center of the fine hole 12 to the center of the adjacent fine hole 12) by electron microscope observation, and these values are averaged to obtain acquired.

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 when the average interval is 100 nm.

The depth of the pores 12 is a measured value of the distance between the bottom of the pores 12 and the top of the protrusions existing between the pores 12 when observed with an electron microscope at a magnification of 3000 times.

The aspect ratio of the pores 12 (depth of pores/average interval between pores) is preferably 0.8-5, more preferably 1.2-4, and particularly preferably 1.5-3.

(Processes (II) and (III))

As a method of treating the surface of the mold body with an organic mold release agent, the following methods (II-1) and (II-2) can be mentioned, from the formation of the mold body that can be uniformly treated with an organic mold release agent From the viewpoint of the surface of one side of the fine uneven structure, the method (II-1) is particularly preferable.

(II-1) A method of immersing the mold main body in a mold release agent solution obtained by diluting the organic mold release agent with an organic solvent.

(II-2) A method of applying an organic release agent or a release agent solution to the surface of the mold main body on which the fine uneven structure is formed.

As method (II-1), the method including following process (g)-(k) is mentioned, for example.

(g) A step of washing the mold main body with water.

(h) A step of blowing air onto the mold main body to remove water droplets adhering to the surface of the mold main body.

(i) A step of immersing the mold main body in a release agent solution.

(j) A step of slowly lifting the dipped mold body from the solution.

(k) A step of drying the mold.

(Effect)

In the manufacturing method of the mold according to the first embodiment of the present invention described above, since the surface of the mold main body is treated with an organic mold release agent judged to have good performance by the performance evaluation method of an organic mold release agent, it is possible to manufacture a surface mold release agent. Fully molded molds.

<Manufacturing method of transparent film>

The third embodiment of the present invention is a method for producing a transparent film having a micro-concave-convex structure on the surface (hereinafter, "transparent film having a micro-concave-convex structure" is simply referred to as "transparent film") is a method of producing a mold that will pass through the present invention. A manufacturing method called nanoimprint method in which the fine uneven structure obtained on the surface of the mold is transferred to the surface of the base film.

The nanoimprint method is a micro-molding method that presses a mold with nano-scale fine unevenness on the surface onto a substrate such as resin to transfer the fine unevenness of the mold. It is mainly classified into the thermal nanoimprint method using a thermal transfer method. Any of the photonanoimprint method using photocuring method can be used in the present invention.

The thermal nanoimprint method is a method in which the base material (thermoplastic material) is heated above the glass transition temperature (that is, the fluidity of the resin is increased), the mold is pressed, and the base material is cooled, and then the mold is released.

The photonanoimprint method is to irradiate an active energy ray such as an ultraviolet ray in a state where a mold is pressed against an active energy ray-curable resin composition on the surface of a base material, and after the active energy ray-curable composition is cured, the mold is released. model method.

As a method for producing the transparent film of the present invention, a method having the following steps (A) to (C) is preferred:

(A) A step of sandwiching the active energy ray-curable resin composition between the surface of the base film and a mold having an inverse structure of a fine uneven structure on the surface and the surface of which has been treated with an organic mold release agent.

(B) A step of irradiating the active energy ray-curable resin composition with active energy rays from the base film side, curing the active energy ray-curable resin composition, forming a cured film, and obtaining a transparent film.

(C) Process of separating the transparent film from the mold.

(manufacturing device)

Production of a transparent thin film by the method having steps (A) to (C) can be performed as follows, for example, using the apparatus shown in FIG. 2 .

The active energy ray-curable resin composition is supplied from a tank 22 between a roll-shaped mold 20 having a fine concave-convex structure (not shown) on the surface and a strip-shaped base film 42 moving along the surface of the mold 20 .

The substrate film 42 and the active energy ray-curable resin composition are clamped between the mold 20 and the nip roller 26 whose nip pressure 24 is adjusted by the pneumatic cylinder 24, so that the active energy ray-curable resin composition is formed between the substrate film 42 and the active energy ray-curable resin composition. The molds 20 are spread uniformly, and at the same time, the concave portions of the fine concavo-convex structure of the mold 20 are filled.

The active energy ray irradiation device 28 installed below the mold 20 irradiates the active energy ray curable resin composition through the base film 42 to cure the active energy ray curable resin composition, thereby forming a transfer print. Cured film 44 having a fine uneven structure on the surface of mold 20 .

The base film 42 on which the cured film 44 is formed on the surface is peeled from the mold 20 by the peeling roller 30 to obtain the transparent film 40 shown in FIG. 3 .

As the active energy ray irradiation device 28, a high-pressure mercury lamp, a metal halide lamp, or the like is preferable, and the light irradiation energy in this case is preferably 100 to 10000 mJ/cm ² .

(substrate film)

As the base film 42 , a film with high transparency is preferable from the viewpoint of irradiating active energy rays through the base film 42 . As a material of the said film, acrylic resin, polyethylene terephthalate, polycarbonate, triacetyl cellulose, etc. are mentioned, for example.

(cured film)

The cured film 44 is a film formed of a cured product of an active energy ray-curable resin composition to be described later, and has a fine uneven structure on the surface.

When using an anodized aluminum mold, the fine uneven structure on the surface of the transparent film 40 is formed by transferring the fine uneven structure on the anodized aluminum surface, and has many a convex portion 46.

The fine concavo-convex structure is preferably a so-called moth-eye structure formed by arranging a plurality of substantially conical, pyramidal, or other protrusions (convex portions). It is known that a moth-eye structure with a spacing between protrusions below the wavelength of visible light constitutes an effective anti-reflection means due to the continuous increase in the refractive index from that of air to that of the material.

The average interval between convex portions is preferably equal to or less than the wavelength of visible light, that is, equal to or less than 400 nm. When the protrusions are formed using an anodized alumina mold, the average interval between the protrusions is about 100 nm, more preferably 200 nm or less, particularly preferably 150 nm or less.

From the viewpoint of easy formation of the convex portions, the average interval between the convex portions is preferably 20 nm or more.

The average interval between convex portions is a value obtained by measuring 50 intervals between adjacent convex portions 19 (the distance from the center of the convex portion to the center of the adjacent convex portion) by electron microscope observation, and averaging these values. .

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, particularly preferably 150 to 300 nm. When the height of the convex portion is 80 nm or more, the reflectance becomes significantly lower, and the wavelength dependence of the reflectance is small. The scratch resistance of a convex part becomes favorable as the height of a convex part is 500 nm or less.

The height of the convex portion is a measured value of the distance between the topmost portion of the convex portion and the lowest portion of the concave portion existing between the convex portions when observed with an electron microscope at a magnification of 30,000.

The aspect ratio of the protrusions (the height of the protrusions/the average interval between the protrusions) is preferably 0.8 to 5.0, more preferably 1.2 to 4.0, and particularly preferably 1.5 to 3.0. When the aspect ratio of a convex part is 1.0 or more, reflectance becomes low remarkably. When the aspect ratio of a convex part is 5.0 or less, the abrasion resistance of a convex part will become favorable.

The shape of the convex part is a shape in which the cross-sectional area of the convex part in the direction perpendicular to the height direction increases continuously from the outermost surface to the depth direction, that is, the cross-sectional shape of the convex part in the height direction is preferably a triangle, trapezoid, bell shape or the like.

The difference between the refractive index of the cured film 44 and the base film 42 is preferably 0.2 or less, more preferably 0.1 or less, particularly preferably 0.05 or less. When the refractive index difference is 0.2 or less, reflection at the interface between the cured coating film 44 and the base film 42 can be suppressed.

It is known that when the surface has a fine concave-convex structure, if the surface is formed of a hydrophobic material, superhydrophobicity can be obtained through the lotus leaf effect, and if the surface is formed of a hydrophilic material, superhydrophilicity can be obtained. sex.

When the material of the cured film 44 is hydrophobic, the water contact angle of the surface of the fine uneven structure is preferably 90° or more, more preferably 110° or more, and particularly preferably 120° or more. When the water contact angle is 90° or more, water stains are less likely to adhere, and thus sufficient antifouling properties can be exhibited. In addition, since water does not easily adhere, it is expected that freezing can be prevented.

When the material of the cured coating 44 is hydrophilic, the water contact angle of the surface of the fine uneven structure is preferably 25° or less, more preferably 23° or less, particularly preferably 21° or less. If the water contact angle is 25° or less, the dirt adhering to the surface can be washed off with water, and oil stains are less likely to adhere, so sufficient antifouling properties can be exhibited. The water contact angle is preferably 3° or more from the viewpoint of suppressing the deformation of the fine uneven structure due to water absorption of the cured film 44 and the accompanying increase in reflectance.

(Active energy ray curable resin composition)

The active energy ray curable resin composition contains a polymerizable compound and a polymerization initiator.

Examples of the polymerizable compound include monomers, oligomers, and reactive polymers having a radically polymerizable bond and/or a cationically polymerizable bond in the molecule.

The active energy ray-curable resin composition may contain a non-reactive polymer and an active energy ray sol-gel reactive composition.

As a monomer which has a radically polymerizable bond, a monofunctional monomer and a polyfunctional monomer are mentioned.

Examples of monofunctional monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, and isobutyl (meth)acrylate. , sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, alkyl (meth)acrylate, (meth)acrylate base) tridecyl acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, phenoxyethyl (meth)acrylate, (meth) Isobornyl acrylate, Glycidyl (meth)acrylate, Tetrahydrofurfuryl (meth)acrylate, Allyl (meth)acrylate, 2-Hydroxyethyl (meth)acrylate, Hydroxy(meth)acrylate (Meth)acrylate derivatives such as propyl ester, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate; (meth)acrylic acid, (meth)acrylonitrile ; Styrene derivatives such as styrene and α-methylstyrene; (meth)acrylamide, N-dimethyl(meth)acrylamide, N-diethyl(meth)acrylamide, dimethyl (Meth)acrylamide derivatives such as aminopropyl (meth)acrylamide, etc. These may be used alone or in combination of two or more.

Examples of polyfunctional monomers include ethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, isocyanurate ethylene oxide-modified di(meth)acrylate, triglyceride Alcohol di(meth)acrylate, Diethylene glycol di(meth)acrylate, Neopentyl glycol di(meth)acrylate, 1,6-Hexanediol di(meth)acrylate, 1,5 -Pentylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, 2,2-bis(4-(methyl) )acryloyloxypolyethoxyphenyl) propane, 2,2-bis(4-(meth)acryloyloxyethoxyphenyl)propane, 2,2-bis(4-(3-( Meth)acryloyloxy-2-hydroxypropoxy)phenyl)propane, 1,2-bis(3-(meth)acryloyloxy-2-hydroxypropoxy)ethane, 1,4 - Ethylene oxide addition of bis(3-(meth)acryloyloxy-2-hydroxypropoxy)butane, dimethyloltricyclodecane di(meth)acrylate, bisphenol A Di(meth)acrylate, propylene oxide adduct of bisphenol A di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, divinylbenzene, methylene Bifunctional monomers such as bisacrylamide; pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethylene oxide modified tri(meth)acrylic acid Ester, trimethylolpropane propylene oxide modified triacrylate, trimethylolpropane ethylene oxide modified triacrylate, isocyanurate ethylene oxide modified tri(meth)acrylate, etc. Functional monomers; condensation reaction mixture of succinic acid/trimethylolethane/acrylic acid, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, bis(trimethylolpropane) tetra Acrylic esters, tetramethylolmethane tetra(meth)acrylate and other monomers with more than four functions; urethane-based acrylates with more than two functions, polyester acrylates with more than two functions, etc. These may be used alone or in combination of two or more.

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

Examples of oligomers or reactive polymers include unsaturated polyesters such as condensation products of unsaturated dicarboxylic acids and polyhydric alcohols; polyester (meth)acrylates, polyether (meth)acrylates, Alcohol (meth)acrylates, epoxy (meth)acrylates, urethane (meth)acrylates, cationic polymerizable epoxy compounds, homogeneous combinations of the above monomers having radically polymerizable bonds on the side chains polymers or copolymers etc.

Examples of non-reactive polymers include acrylic resins, styrene resins, polyurethanes, cellulose resins, polyvinyl butyral, polyesters, and thermoplastic elastomers.

Examples of the active energy ray sol-gel reactive composition include alkoxysilane compounds, alkyl silicate compounds, and the like.

Examples of the alkoxysilane compound include compounds of the following formula (1):

R ¹¹ _x Si(OR ¹² ) _y ···(1)

However, R ¹¹ and R ¹² each represent an alkyl group having 1 to 10 carbon atoms, and x and y represent integers satisfying the relationship of x+y=4.

Examples of alkoxysilane compounds include tetramethoxysilane, tetraisopropoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert-butoxysilane , Methyltriethoxysilane, Methyltripropoxysilane, Methyltributoxysilane, Dimethyldimethoxysilane, Dimethyldiethoxysilane, Trimethylethoxysilane , Trimethylmethoxysilane, trimethylpropoxysilane, trimethylbutoxysilane, etc.

Examples of the alkyl silicate compound include compounds of the following formula (2):

R ²¹ O[Si(OR ²³ )(OR ²⁴ )O] _z R ²² ···(2)

Wherein, R ²¹ to R ²⁴ each represent an alkyl group having 1 to 5 carbon atoms, and z represents an integer of 3 to 20.

Examples of alkyl silicate compounds include methyl silicate, ethyl silicate, isopropyl silicate, n-propyl silicate, n-butyl silicate, n-pentyl silicate, and acetyl silicate. .

When photocuring reaction is used, examples of photopolymerization initiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzyl, Benzophenone, p-methoxybenzophenone, 2,2-diethoxyacetophenone, α,α-dimethoxy-α-phenylacetophenone, methyl benzoylformate, benzoyl Carbonyl compounds such as ethyl formate, 4,4'-bis(dimethylamino)benzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc.; Tetramethylqiuran monosulfide 2,4,6-trimethylbenzoyldimethylphosphine oxide, benzoyldiethoxyphosphine oxide, etc. These may be used alone or in combination of two or more.

When the electron beam curing reaction is used, examples of the polymerization initiator include benzophenone, 4,4-bis(diethylamino)benzophenone, and 2,4,6-trimethylbenzophenone. , methyl phthaloylbenzoate, 4-phenylbenzophenone, tert-butylanthraquinone, 2-ethylanthraquinone, 2,4-diethylthioxanthone, isopropylthioxanthone, Thioxanthones such as 2,4-dichlorothioxanthone; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzoin dimethyl ether, 1-hydroxycyclo Hexyl-phenyl ketone, 2-methyl-2-morpholinyl (4-thiomethylphenyl) propan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholin benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether and other benzoin ethers; 2,4,6- Trimethylbenzoyldiphenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, bis(2,4,6-tri Acyl phosphine oxides such as methylbenzoyl)-phenylphosphine oxide; methyl benzoylformate, 1,7-diacridinylheptane, 9-phenylacridine, etc. These may be used alone or in combination of two or more.

When thermal curing reaction is utilized, examples of thermal polymerization initiators include methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tertiary octanoic acid peroxide, Butyl ester, tert-butyl peroxybenzoate, lauroyl peroxide and other organic peroxides; azo-based compounds such as azobisisobutyronitrile; N,N-dimethylaniline, N,N-dimethyl - A redox polymerization initiator in which an amine such as p-toluidine is combined with the above-mentioned organic peroxide, and the like.

The amount of the polymerization initiator is preferably 0.1 to 10 parts by mass relative to 100 parts by mass of the polymerizable compound. When the amount of the polymerization initiator is less than 0.1 parts by mass, it is difficult to carry out polymerization. When the quantity of a polymerization initiator exceeds 10 mass parts, a cured film may be colored or mechanical strength may fall.

The active energy ray-curable resin composition may contain antistatic agents, mold release agents, additives such as fluorine compounds for improving antifouling properties, fine particles, and a small amount of solvents, as needed.

(hydrophobic material)

In order to set the water contact angle of the surface of the fine uneven structure of the cured film 44 to 90° or more, it is preferable to use a fluorine-containing compound or a silicone-based active energy ray-curable resin composition as a material capable of forming hydrophobicity. Composition of compounds.

Fluorochemicals:

As the fluorine-containing compound, a compound having a fluoroalkyl group represented by the following formula (3) is preferable:

-(CF ₂ ) _n -X ···(3)

Wherein, X represents a fluorine atom or a hydrogen atom, n represents an integer of 1 or more, preferably 1-20, more preferably 3-10, particularly preferably 4-8.

Examples of the fluorine-containing compound include fluorine-containing monomers, fluorine-containing silane coupling agents, fluorine-containing surfactants, fluorine-containing polymers, and the like.

Examples of the fluorine-containing monomer include fluoroalkyl-substituted vinyl monomers, fluoroalkyl-substituted ring-opening polymerizable monomers, and the like.

Examples of fluoroalkyl-substituted vinyl monomers include fluoroalkyl-substituted (meth)acrylates, fluoroalkyl-substituted (meth)acrylamides, fluoroalkyl-substituted vinyl ethers, and fluoroalkyl-substituted styrenes. .

As a fluoroalkyl-substituted ring-opening polymerizable monomer, a fluoroalkyl-substituted epoxy compound, a fluoroalkyl-substituted oxetane compound, a fluoroalkyl-substituted oxazoline compound, etc. are mentioned.

As the fluorine-containing monomer, a fluoroalkyl-substituted (meth)acrylate is preferable, and a compound of the following formula (4) is particularly preferable.

CH ₂ =C(R ⁴¹ )C(O)O-(CH ₂ ) _m -(CF ₂ ) _n -X ···(4)

Wherein, R ^represents a hydrogen atom or a methyl group, X represents a hydrogen atom or a fluorine atom, m represents an integer of 1 to 6, preferably 1 to 3, more preferably 1 or 2, n represents an integer of 1 to 20, preferably 3 to 10 , more preferably 4~8.

As the fluorine-containing silane coupling agent, the fluoroalkyl-substituted silane coupling agent is preferred, and the compound of the following formula (5) is particularly preferred:

(R ^f ) _a R ⁵¹ _b SiY _c ···(5)

R ^f represents a fluorine-substituted alkyl group having 1 to 20 carbon atoms optionally containing one or more ether bonds or ester bonds. Examples of R ^f include 3,3,3-trifluoropropyl, tridecafluoro-1,1,2,2-tetrahydrooctyl, 3-trifluoromethoxypropyl, 3-trifluoroacetyl Oxypropyl etc.

R ⁵¹ represents an alkyl group having 1 to 10 carbon atoms. Examples of R ⁵¹ include methyl, ethyl, cyclohexyl and the like.

Y represents a hydroxyl group or a hydrolyzable group.

Examples of the hydrolyzable group include an alkoxy group, a halogen atom, R ⁵² C(O)O (where R ⁵² represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms), and the like.

Examples of the alkoxy group include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, pentyloxy, hexyloxy, and cyclohexyloxy Heptyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy, 3,7-dimethyloctyloxy, lauryloxy, etc.

Cl, Br, I, etc. are mentioned as a halogen atom.

Examples of R ⁵² C(O)O include CH ₃ C(O)O, C ₂ H ₅ C(O)O, and the like.

a, b, and c represent integers satisfying a+b+c=4 and a≥1, c≥1, preferably a=1, b=0, c=3.

Examples of fluorine-containing silane coupling agents include 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriacetoxysilane, dimethyl-3,3, 3-trifluoropropylmethoxysilane, tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane, etc.

As a fluorine-containing surfactant, a fluorine-containing alkyl anionic surfactant, a fluorine-containing alkyl cationic surfactant, etc. are mentioned.

Examples of fluorine-containing alkyl anionic surfactants include fluoroalkyl carboxylic acids with 2 to 10 carbon atoms or metal salts thereof, disodium perfluorooctylsulfonyl glutamate, 3-[ω-fluoroalkane Base (C ₆ ~C ₁₁ )oxy]-1-alkyl (C ₃ ~C ₄ ) sodium sulfonate, 3-[ω-fluoroalkanoyl (C ₆ ~C ₈ )-N-ethylamino]- Sodium 1-propylsulfonate, fluoroalkyl (C ₁₁ ~C ₂₀ ) carboxylic acid or its metal salt, perfluoroalkyl carboxylic acid (C ₇ ~C ₁₃ ) or its metal salt, perfluoroalkyl (C ₄ ~C ₁₂ ) sulfonic acid or its metal salt, perfluorooctane sulfonic acid diethanolamide, N-propyl-N-(2-hydroxyethyl) perfluorooctane sulfonamide, perfluoroalkyl (C ₆ ~ C ₁₀ ) sulfonamide propyl trimethyl ammonium salt, perfluoroalkyl (C ₆ ~C ₁₀ )-N-ethylsulfonyl glycinate, monoperfluoroalkyl (C ₆ ~C ₁₆ ) ethyl phosphate wait.

As fluorine-containing alkyl cationic surfactants, fluorine-containing alkyl aliphatic primary, secondary or tertiary amino acids, perfluoroalkyl (C ₆ ~C ₁₀ ) sulfonamide propyl trimethyl ammonium salt and other aliphatic Quaternary ammonium salts, benzalkonium salts, benzethonium chloride, pyridinium salts, imidazolium salts, etc.

Examples of fluoropolymers include polymers of fluoroalkyl monomers, copolymers of fluoroalkyl monomers and poly(oxyalkylene) monomers, fluoroalkyl monomers Copolymers of sexual group monomers, etc. Fluoropolymers may also be copolymers of fluoroalkyl monomers and other copolymerizable monomers.

As the fluorine-containing polymer, copolymers of fluorine-containing alkyl monomers and poly(oxyalkylene)-containing monomers are preferred.

As the poly(oxyalkylene), groups represented by the following formula (6) are preferred:

-(OR ⁶¹ ) _p -···(6)

Wherein, R ⁶¹ represents an alkylene group having 2 to 4 carbon atoms, and p represents an integer of 2 or more. Examples of R ⁶¹ include -CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ -, -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, and the like.

The poly(oxyalkylene) may be a group consisting of the same oxyalkylene unit (OR ⁶¹ ), or a group consisting of two or more kinds of oxyalkylene units (OR ⁶¹ ). The arrangement of two or more kinds of oxyalkylene units (OR ⁶¹ ) may be block or random.

Silicone compounds:

Examples of the silicone-based compound include (meth)acrylic-modified silicone, silicone resin, silicone-based silane coupling agent, and the like.

Examples of the (meth)acryl-modified silicone include silicone (di)(meth)acrylate and the like.

(hydrophilic material)

In order to set the water contact angle of the surface of the fine concavo-convex structure of the cured film 44 to 25° or less, as the active energy ray-curable resin composition that can form a hydrophilic material, it is preferable to use Compositions. In addition, from the viewpoint of imparting scratch resistance and water resistance, it is more preferable to contain a crosslinkable polyfunctional monomer. Wherein, the hydrophilic monomer and the crosslinkable polyfunctional monomer may be the same (ie, hydrophilic polyfunctional monomer). In addition, the active energy ray-curable resin composition may contain other monomers.

As the active energy ray-curable resin composition capable of forming a hydrophilic material, it is more preferable to use a composition containing a structural unit derived from a polymerizable compound described below. It is preferable to use a polymeric compound-derived structural unit containing 10 to 50% by mass of a tetrafunctional or more functional (meth)acrylate-derived structural unit with respect to 100% by mass of the total of the structural units constituting the polymeric compound. , A composition comprising 30 to 80 mass % of structural units derived from bifunctional or higher hydrophilic (meth)acrylates and 0 to 20 mass % of structural units derived from monofunctional monomers.

Examples of polyfunctional (meth)acrylates having four or more functions include bis(trimethylolpropane)tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol ethoxytetra(meth)acrylate, ) acrylate, dipentaerythritol hydroxypenta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, condensation reaction mixture of succinic acid/trimethylolethane/acrylic acid molar ratio 1:2:4, amino Formate acrylates (manufactured by DAICEL-CYTEC Company LTD.: EBECRYL220, EBECRYL1290, EBECRYL1290K , EBECRYL5129, EBECRYL8210, EBECRYL8301, KRM8200), polyether acrylates (manufactured by DAICEL-CYTEC Company LTD., EBECRYL81, modified) Epoxy acrylates (manufactured by DAICEL-CYTEC Company LTD., EBECRYL3416), polyester acrylates (manufactured by DAICEL-CYTEC Company LTD.: EBECRYL450, EBECRYL657, EBECRYL800, EBECRYL810, EBECRYL811, EBECRYL812, EBECRYL1830, EBECRYB848, etc.) . These may be used alone or in combination of two or more.

As the tetrafunctional or more polyfunctional (meth)acrylate, pentafunctional or more polyfunctional (meth)acrylate is more preferable.

The proportion of constituent units derived from tetrafunctional or higher polyfunctional (meth)acrylates is preferably 10 to 50% by mass, more preferably 20 to 50% by mass from the viewpoint of water resistance and chemical resistance, and particularly preferably It is 30~50% by mass. When the ratio of the constituent units derived from the tetrafunctional or higher polyfunctional (meth)acrylate is 10% by mass or more, the modulus of elasticity increases and scratch resistance improves. When the ratio of the constituent units derived from the tetrafunctional or higher polyfunctional (meth)acrylate is 50% by mass or less, small cracks are less likely to be formed on the surface, and appearance defects are less likely to occur.

Examples of bifunctional or higher hydrophilic (meth)acrylates include ARONIX M-240, ARONIX M260 (manufactured by Toagosei Co., Ltd.), NKESTER AT-20E, NK ESTER ATM-35E (manufactured by Shin-Nakamura Chemical Co., Ltd.), etc. Polyfunctional acrylates with long chain polyethylene glycol, polyethylene glycol dimethacrylate, etc. These may be used alone or in combination of two or more.

In polyethylene glycol dimethacrylate, the total of the average repeating units of polyethylene glycol chains present in one molecule is preferably 6-40, more preferably 9-30, and particularly preferably 12-20. When the average repeating unit of the polyethylene glycol chain is 6 or more, hydrophilicity becomes sufficient and antifouling property improves. When the average repeating unit of the polyethylene glycol chain is 40 or less, the compatibility with the tetrafunctional or more polyfunctional (meth)acrylate becomes favorable, and the active energy ray-curable resin composition is not easily separated.

The ratio of the structural unit derived from the bifunctional or more hydrophilic (meth)acrylate is preferably 30 to 80% by mass, more preferably 40 to 70% by mass. When the ratio of the bifunctional or higher hydrophilic (meth)acrylate is 30% by mass or more, hydrophilicity becomes sufficient and antifouling property improves. When the proportion of bifunctional or higher hydrophilic (meth)acrylate is 80% by mass or less, the modulus of elasticity increases and scratch resistance improves.

As the monofunctional monomer, a hydrophilic monofunctional monomer is preferable.

Examples of the hydrophilic monofunctional monomer include monofunctional (meth)acrylates having polyethylene glycol chains on their ester groups such as M-20G, M-90G, and M-230G (manufactured by Shin-Nakamura Chemical Co., Ltd.), Monofunctional (meth)acrylates having a hydroxyl group on the ester group such as hydroxyalkyl (meth)acrylate, monofunctional acrylamides, methacrylamidopropyltrimethylammonium methylsulfate, methacryloxy Cationic monomers such as ethyl ethyl trimethyl ammonium methyl sulfate, etc.

Moreover, as a monofunctional monomer, viscosity modifiers, such as acryloyl morpholine and vinylpyrrolidone, and an adhesive improvement agent, such as acryloyl isocyanate which improves the adhesiveness to an article main body, etc. can be used.

The proportion of constituent units derived from monofunctional monomers is preferably 0 to 20% by mass, more preferably 5 to 15% by mass. By using the structural unit derived from a monofunctional monomer, the adhesiveness of a part main body and curable resin improves. If the proportion of structural units derived from monofunctional monomers is 20% by mass or less, structural units derived from tetrafunctional or higher polyfunctional (meth)acrylates or bifunctional or higher hydrophilic (meth) Acrylic constituent units are sufficient to fully express stain resistance or scratch resistance.

Monofunctional monomers can be blended in an active energy ray-curable resin composition in an amount of 0 to 35 parts by mass as one or more polymers (copolymerized) with a low degree of polymerization. Examples of polymers with a low degree of polymerization include M-230G (manufactured by Shin-Nakamura Chemical Co., Ltd.), monofunctional (meth)acrylates having a polyethylene glycol chain on the ester group, and methacrylamidopropyltrimethylmethacrylate. 40/60 copolymerized oligomer of ammonium methylsulfate (manufactured by MRC UNITEC Co., Ltd., MG Polymer), etc.

(use)

Examples of applications of the transparent film 40 include anti-reflection films, anti-fogging films, anti-fouling films, and water-repellent films, and more specifically, anti-reflection films for displays and meter covers for automobiles. , automotive reflectors, automotive windows, organic or inorganic electroluminescent light output efficiency improvement components, solar cell components, etc.

However, the transparent film is not limited to the transparent film 40 of the illustrated example. For example, the fine concavo-convex structure may be formed directly on the surface of the base film 42 without providing the cured coating 44 . However, from the viewpoint of efficiently forming the fine uneven structure using the roll-shaped mold 20 , it is preferable to form the fine uneven structure on the surface of the cured film 44 .

(Effect)

The method for producing a transparent film according to the third embodiment of the present invention described above uses a mold having sufficient surface releasability obtained by the method for producing a mold of the present invention, so that a transparent film can be stably produced.

Example

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

(Example 1)

(Preparation of release agent solution)

Using OPTOOL DSX (manufactured by DAIKIN INDUSTRIES, Ltd.) as an organic release agent and DURASURF HD-ZV (manufactured by HARVES Co., Ltd.) as an organic solvent for dilution, a release agent concentration of 0.1% by mass was prepared. agent solution.

(Performance evaluation of release agent)

The prepared release agent solution was mixed with N,N-dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd., special grade, dielectric constant (25° C.): 36.71) at a volume ratio of 1:1 to form a mixture. The light transmittance of the mixture was measured with a spectrophotometer (manufactured by Hitachi, Ltd., U-3300). As a reference, a 1:1 volume ratio mixture of DURASURF HD-ZV and N,N-dimethylformamide was used. As a result of the measurement, the light transmittance at a wavelength of 400 nm was 93%.

(manufacturing of molds)

An aluminum plate (purity 99.99%) of 50mm×50mm×thickness 0.3mm was electrolytically ground in a mixed solution of perchloric acid/ethanol (1/4 volume ratio).

Process (a):

The above-mentioned aluminum plate was anodized in 0.3M oxalic acid aqueous solution for 6 hours under the conditions of direct current 40V and temperature 16°C.

Process (b):

The aluminum plate on which the oxide film was formed was immersed in a 6% by mass phosphoric acid/1.8% by mass chromic acid mixed aqueous solution for 3 hours to remove the oxide film.

Process (c):

The above-mentioned aluminum plate was anodized in 0.3M oxalic acid aqueous solution for 30 seconds under the conditions of direct current 40V and temperature 16°C.

Process (d):

The aluminum plate on which the oxide film was formed was immersed in a 5% by mass phosphoric acid aqueous solution at 32° C. for 8 minutes to perform a pore diameter expanding treatment.

Process (e):

The above-mentioned aluminum plate was anodized in 0.3M oxalic acid aqueous solution for 30 seconds under the conditions of direct current 40V and temperature 16°C.

Process (f):

The above step (d) and step (e) were repeated 4 times in total, and finally step (d) was performed to obtain anodized aluminum oxide having roughly conical pores with an average period of about 100 nm and a depth of about 240 nm formed on the surface The mold body a.

Process (g):

The phosphoric acid aqueous solution on the surface of the mold main body a was lightly rinsed off using a shower, and then the mold main body a was immersed in running water for 10 minutes.

Process (h):

Air is blown onto the mold main body a with an air gun to remove water droplets adhering to the surface of the mold main body a.

Process (i):

The mold main body a was dipped in the above-mentioned release agent solution at room temperature for 10 minutes.

Process (j):

Lift the mold body a out of the release agent solution at a speed of 3 mm/sec.

Process (k):

The mold main body a was air-dried for 15 minutes to obtain a mold treated with a release agent.

(Active energy ray curable resin composition)

As the active energy ray-curable resin composition, a composition of the following composition was prepared:

Condensation reaction mixture with a molar ratio of succinic acid/trimethylolethane/acrylic acid of 1:2:4: 45 parts by mass,

1,6-hexanediol diacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.): 45 parts by mass,

Radical polymerizable silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., X-22-1602): 10 parts by mass

1-hydroxycyclohexyl phenyl ketone (manufactured by Ciba Specialty Chemicals, Irgacure 184); 3 parts by mass.

(Manufacture of transparent film)

The active energy ray-curable resin composition is poured into the side of the mold on which the fine concave-convex structure is formed, covered with an acrylic film as a base film, and then cured by an ultraviolet irradiation machine (high-pressure mercury lamp, cumulative light intensity: 400mJ/cm ² ) . Next, by releasing the cured film from the mold together with the base film, the fine concave-convex structure of the mold was transferred to the acrylic film. The stripping can be carried out smoothly.

(Example 2)

The release agent solution of Example 1 was not replaced, and the surface treatment of the mold main body a was repeated 10 times with the same release agent solution, and the release agent solution and the same N,N-dimethyl formazan as in Example 1 were measured. The light transmittance of the 1:1 volume ratio mixture of amides, as a result, the light transmittance at a wavelength of 400nm is 80%.

Except having used the above-mentioned release agent solution, it carried out similarly to Example 1, and transferred the fine uneven|corrugated structure of a mold to an acrylic film. The stripping can be carried out smoothly.

(Example 3)

The release agent solution of Example 1 was not replaced, and the surface treatment of the mold main body a was repeated 20 times with the same release agent solution, and the release agent solution and the same N,N-dimethyl formazan as in Example 1 were measured. The light transmittance of the 1:1 volume ratio mixture of amides, as a result, the light transmittance at a wavelength of 400nm is 64%.

Except having used the above-mentioned release agent solution, it carried out similarly to Example 1, and transferred the fine uneven|corrugated structure of a mold to an acrylic film. The stripping can be carried out smoothly.

(comparative example 1)

The release agent solution of Example 2 was not replaced, and the surface treatment of the mold body a was further carried out more than 5 times with the same release agent solution, and the release agent solution and the same N,N-dimethyl The light transmittance of the 1:1 volume ratio mixture of formamide, as a result, the light transmittance at a wavelength of 400nm is 35%.

In the same manner as in Example 1, except that the mold release agent solution was used, the fine concave-convex structure of the mold was transferred to the acrylic film. As a result, the acrylic film could not be released from the mold from the first transfer.

Industrial availability

The mold obtained by the production method of the present invention can be used to produce an optical film having a fine concave-convex structure called a moth-eye structure on the surface.

Claims (10)

1. A manufacturing method of a mould, which has the following steps (I) to (III): (1) making the operation that the surface has formed the mold main body of micro-concave-convex structure; (II) A step of evaluating the deterioration of the performance of the organic mold release agent according to the performance evaluation method of the organic mold release agent described below; and, (III) a step of treating the surface of the mold main body prepared in the step (I) with an organic mold release agent judged to have good performance in the step (II), The method for evaluating the performance of the organic mold release agent is to mix the organic mold release agent with the organic solvent for the test, and judge the organic mold release agent by the solubility of the organic mold release agent in the organic solvent for the test. The performance of the method is good or bad. 2. The manufacturing method of the mold according to claim 1, wherein the step (I) is a step of forming an anodized aluminum oxide having a plurality of fine pores on the surface of the aluminum substrate to manufacture the mold main body. 3. The method for manufacturing a mold according to claim 1, wherein the organic mold release agent is a fluorine compound having a hydrolyzable silyl group or a silanol group. 4. The manufacturing method of the mold according to claim 1, wherein the dielectric constant of the organic solvent for the test is 22-40. 5. The manufacturing method of the mold according to claim 1, wherein the organic solvent for the test is ethanol or N,N-dimethylformamide. 6. the manufacture method of mold according to claim 1, wherein, judge the dissolving of organic system mold release agent in described test organic solvent by the light transmittance of the mixture of organic system mold release agent and test organic solvent Good or bad sex. 7. A method for evaluating the performance of an organic mold release agent, which is to mix an organic mold release agent with an organic solvent for testing, and determine whether the organic mold release agent has a good or bad solubility in the organic solvent for testing. The performance of the release agent is good or bad. 8. The performance evaluation method of an organic mold release agent according to claim 7, wherein the mold release agent solution is formed by diluting the organic mold release agent with an organic solvent for dilution in advance. 9 . The performance evaluation method of an organic mold release agent according to claim 8 , wherein the organic mold release agent is used to treat the surface of a mold main body having a fine concave-convex structure formed on the surface. 10. A method for manufacturing a transparent film having a micro-concave-convex structure on the surface, comprising: transferring the micro-concave-convex structure of the surface of the mold obtained by the method for producing a mold according to any one of claims 1 to 6 to The surface of the substrate film.