JP2018144360A - Mold manufacturing method, article manufacturing method and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold manufacturing method which has excellent productivity and can obtain a mold which can obtain an article having excellent anti-reflection performance and anti-glare performance, to provide an article manufacturing method which can obtain an article having excellent anti-reflection performance and anti-glare performance, and to provide an article having excellent anti-reflection performance and anti-glare performance.SOLUTION: A mold manufacturing method includes a step (a) to a step (f) successively and uses the same kind of processing liquid through the step (a) to the step (f). The step (a): a step for immersing an aluminum substrate in the processing liquid. The step (b): a first oxide film formation step for anodizing the aluminum substrate to form an oxide film having pores. The step (c): an oxide film removal step for removing a part of the oxide film. The step (d): a second oxide film formation step for anodizing the aluminum substrate under a constant voltage to form an oxide film having pores. The step (e): a pore diameter enlargement processing step for removing a part of the oxide film to enlarge the diameters of the pores. The step (f): a step for successively repeating the step (d) and the step (e).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mold manufacturing method, an article manufacturing method, and an article.

  In recent years, it has become possible to impart a nanoscale fine concavo-convex structure to the surface of a molded body due to advances in microfabrication technology. In particular, a fine uneven structure called a moth-eye structure is known to exhibit an effective antireflection function by continuously increasing from the refractive index of air to the refractive index of a material. .

  As described above, an article having a fine concavo-convex structure having a period of less than or equal to the wavelength of visible light, that is, a moth-eye structure on the surface exhibits antireflection performance, and thus has attracted attention for its usefulness. In addition to anti-reflective performance, the moth-eye structure expresses functions derived from the structure, such as a water repellent function called the Lotus effect. Has been done.

  There are various techniques for imparting a fine relief structure to the surface of a molded body, but the method for transferring the fine relief structure formed on the surface of the mold to the surface of the molded body gives a fine relief structure to the surface of the molded body. This is suitable for industrial production because it requires only a small number of steps and is simple. As a method for easily producing a large-area mold having a fine concavo-convex structure on the surface, a method utilizing an oxide film (anodized porous alumina) having a plurality of pores by anodizing an aluminum base material has attracted attention. Yes.

  Examples of a method for forming an oxide film having a plurality of pores by anodizing an aluminum substrate include methods disclosed in Patent Documents 1 to 4.

International Publication No. 2008/001847 Pamphlet International Publication No. 2011-046114 Pamphlet International Publication No. 2014/092048 JP 2009-221562 A

  However, since the methods disclosed in Patent Documents 1 to 4 use different treatment liquids for each process, a plurality of processes cannot be performed in one reaction tank, and productivity is inferior. There is a problem that a heavy manufacturing facility corresponding to the processing liquid must be designed. In addition, by using different processing liquids for each process, it is possible to form and control nano-order concavo-convex structures, but it is difficult to form and control micro-order concavo-convex structures, and to obtain articles with excellent antiglare properties. Has the problem of being difficult.

Then, this invention solves these subjects, and is providing the manufacturing method of the mold which is excellent in productivity, and is excellent in the antireflection performance of the article | item obtained using the mold obtained, and anti-glare property.
Moreover, this invention is providing the manufacturing method of the articles | goods which are excellent in the antireflection performance and anti-glare property of the articles | goods obtained.
Furthermore, the present invention is to provide an article excellent in antireflection performance and antiglare property.

The present invention has the following aspects.
[1] A method for producing a mold, which includes the following steps (a) to (f) in sequence, wherein the treatment liquid in the following steps (a) to (f) is the same kind of liquid.
Step (a): A step of immersing the aluminum substrate in the treatment liquid.
Step (b): a first oxide film forming step of forming an oxide film having pores by anodizing an aluminum substrate.
Step (c): An oxide film removing step for removing a part of the oxide film.
Step (d): a second oxide film forming step of forming an oxide film having pores by anodizing an aluminum substrate at a constant voltage.
Step (e): A pore diameter enlargement treatment step in which part of the oxide film is removed to enlarge the pore diameter.
Step (f): A step of alternately repeating the step (d) and the step (e).
[2] The method for producing a mold according to [1], wherein the treatment liquid is a mixture of a plurality of acids.
[3] The method for producing a mold according to [2], wherein the plurality of acids include oxalic acid and phosphoric acid.
[4] The method for producing a mold according to any one of [1] to [3], wherein in the step (c), a recess is formed in a lower portion of the remaining oxide film.
[5] A fine concavo-convex structure for transferring a fine concavo-convex structure comprising a plurality of pores formed on the surface of a mold obtained by the production method according to any one of [1] to [4] to the surface of an article A method for manufacturing an article having a surface thereof.
[6] A fine concavo-convex structure having an inverted structure of the fine concavo-convex structure composed of a plurality of pores formed on the surface of the mold obtained by the production method according to any one of [1] to [4] The article you have.

The mold manufacturing method of the present invention is excellent in productivity and excellent in antireflection performance and antiglare property of an article obtained using the obtained mold.
Moreover, the manufacturing method of the articles | goods of this invention is excellent in the antireflection performance and anti-glare property of the articles | goods obtained.
Furthermore, the article of the present invention is excellent in antireflection performance and antiglare property.

It is typical sectional drawing which shows an example of the process in the manufacturing method of the mold of this invention. It is typical sectional drawing which shows the manufacturing apparatus of the articles | goods which have a fine concavo-convex structure on the surface. It is typical sectional drawing which shows an example of the article | item which has a fine concavo-convex structure on the surface.

(Mold manufacturing method)
The mold manufacturing method of the present invention sequentially includes the following steps (a) to (f), and the processing liquid in the following steps (a) to (f) is the same kind of liquid.
Step (a): A step of immersing the aluminum substrate in the treatment liquid.
Step (b): a first oxide film forming step of forming an oxide film having pores by anodizing an aluminum substrate.
Step (c): An oxide film removing step for removing a part of the oxide film.
Step (d): a second oxide film forming step of forming an oxide film having pores by anodizing an aluminum substrate at a constant voltage.
Step (e): A pore diameter enlargement treatment step in which part of the oxide film is removed to enlarge the pore diameter.
Step (f): A step of alternately repeating the step (d) and the step (e).

(Processing liquid)
A process liquid will not be limited if the objective of each process of a process (a)-a process (f) is achieved. Since the treatment liquid achieves the purpose of each step (a) to step (f), a plurality of acids are preferable, and an acid that contributes to the formation of an oxide film (hereinafter referred to as “first acid”). And an acid useful for etching that dissolves the oxide film, that is, enlarges the pores formed in the oxide film (hereinafter sometimes referred to as “second acid”).

The purpose of the treatment liquid in step (a) and step (b) is to form an oxide film having pores by anodic oxidation.
The purpose of the treatment liquid in the step (c) is to remove a part of the oxide film.
The purpose of the treatment liquid in the step (d) is to form an oxide film having pores by anodic oxidation.
The purpose of the treatment liquid in step (e) is to remove part of the oxide film and enlarge the pores formed in the oxide film.
The purpose of the treatment liquid in the step (f) is the same as in the step (d) and the step (e).

Examples of the acid include sulfuric acid, phosphoric acid, oxalic acid, malonic acid, tartaric acid, succinic acid, malic acid, citric acid and the like.
Examples of the first acid include oxalic acid and sulfuric acid.
Examples of the second acid include phosphoric acid.

  The plurality of acids are easy to form highly regular pores on the surface of the aluminum base, easy to control the shape of the pores, can form the second recess described later, and should be chromium-free. Therefore, a combination of oxalic acid and phosphoric acid is preferable.

After determining the types of the first acid and the second acid, the composition of the plurality of acids is determined depending on the temperature at the time of anodization (step (b), step (d), step (f)). It is preferable to determine the concentration of.
The composition and temperature of the plurality of acids affect the depth of pores during anodization and the speed of expansion of the pore diameter during etching. If the concentration of the second acid is increased or the temperature of the treatment liquid is increased, the expansion speed of the pore diameter at the time of etching is increased, and the pores can be expanded in a short time. On the other hand, control of the pore diameter becomes difficult as the expansion speed of the pore diameter increases. Therefore, it is important to control the composition and temperature of a plurality of acids in order to form pores having a desired shape and a desired pore diameter on the surface of the aluminum substrate.

When the first acid is oxalic acid, the second acid is phosphoric acid, and the temperature of the treatment liquid during anodization is 4 ° C. or higher and lower than 20 ° C., the concentration of oxalic acid in the treatment liquid is 0. 05 mol / l to 1 mol / l is preferable, and 0.2 mol / l to 0.7 mol / l is more preferable. When the concentration of oxalic acid in the treatment liquid is 0.05 mol / l or more, a current flows stably and pores can be stably formed. Further, when the concentration of oxalic acid in the treatment liquid is 1 mol / l or less, the current value does not become too high, and the surface of the oxide film can be prevented from becoming rough.
When the first acid is oxalic acid, the second acid is phosphoric acid, and the temperature of the treatment liquid during anodization is 4 ° C. or higher and lower than 20 ° C., the concentration of phosphoric acid in the treatment liquid is 0.00. 05 mol / l to 3 mol / l is preferable, and 0.1 mol / l to 2 mol / l is more preferable. When the concentration of phosphoric acid in the treatment liquid is 0.05 mol / l or more, the dissolution of the oxide film is sufficiently fast and the mold productivity is excellent. Further, when the concentration of phosphoric acid in the treatment liquid is 3 mol / l or less, it is easy to control the removal rate of the oxide film and the expansion rate of the pore diameter.

When the first acid is oxalic acid, the second acid is phosphoric acid, and the temperature of the treatment liquid during anodic oxidation is 20 ° C. or higher and lower than 35 ° C., the concentration of oxalic acid in the treatment liquid is 0. 05 mol / l to 1 mol / l is preferable, and 0.1 mol / l to 0.5 mol / l is more preferable. When the concentration of oxalic acid in the treatment liquid is 0.05 mol / l or more, a current flows stably and pores can be stably formed. Further, when the concentration of oxalic acid in the treatment liquid is 1 mol / l or less, the current value does not become too high, and the surface of the oxide film can be prevented from becoming rough.
When the first acid is oxalic acid, the second acid is phosphoric acid, and the temperature of the treatment solution during anodization is 20 ° C. or more and less than 35 ° C., the concentration of phosphoric acid in the treatment solution is 0. 02 mol / l to 2.5 mol / l is preferable, and 0.05 mol / l to 1.5 mol / l is more preferable. When the concentration of phosphoric acid in the treatment liquid is 0.02 mol / l or more, dissolution of the oxide film is sufficiently fast and the mold productivity is excellent. Further, when the concentration of phosphoric acid in the treatment liquid is 2.5 mol / l or less, it is easy to control the removal rate of the oxide film and the expansion rate of the pore diameter.

When the first acid is sulfuric acid, the second acid is phosphoric acid, and the temperature of the treatment liquid during anodization is 30 ° C. or lower, the concentration of sulfuric acid in the treatment liquid is 0.05 mol / l to 0 0.7 mol / l is preferred. When the concentration of sulfuric acid in the treatment liquid is 0.05 mol / l or more, a current flows stably and pores can be stably formed. Further, when the concentration of sulfuric acid in the treatment liquid is 0.7 mol / l or less, the current value does not become too high, and a constant voltage can be maintained.
When the first acid is sulfuric acid, the second acid is phosphoric acid, and the temperature of the treatment liquid during anodization is 30 ° C. or lower, the concentration of phosphoric acid in the treatment liquid is 0.02 mol / l to 3 mol / l is preferred. When the concentration of phosphoric acid in the treatment liquid is 0.02 mol / l or more, dissolution of the oxide film is sufficiently fast and the mold productivity is excellent. Further, when the concentration of phosphoric acid in the treatment liquid is 3 mol / l or less, it is easy to control the removal rate of the oxide film and the expansion rate of the pore diameter.

  The mixing ratio of the first acid and the second acid is 0.5: 99 because pores with high regularity are easily formed on the surface of the aluminum base and the shape of the pores is easily controlled. 0.5 to 90:10 (mass ratio) is preferable, and 0.7: 99.3 to 80:20 (mass ratio) is more preferable.

An anodic oxidation process for forming an oxide film on the surface of the aluminum base by using the same kind of liquid as the treatment liquid in each of the steps (a) to (f), and an oxide film removal for removing a part of the oxide film Since all the processes of the process and the etching process of enlarging the pores formed in the oxide film can be performed in one reaction tank, the manufacturing equipment is simplified and the productivity of the mold is excellent.
Here, the same kind of liquid is used, for example, when a mixture of oxalic acid and phosphoric acid is used as a treatment liquid, oxalic acid and phosphorus are used in any of the steps (a) to (f). It means using what mixed the acid as a processing liquid.

(Process (a))
Step (a) is a step of immersing the aluminum substrate in the treatment liquid.

  Examples of the shape of the aluminum base material include a roll shape, a circular tube shape, a flat plate shape, and a sheet shape. Among the shapes of these aluminum substrates, a roll shape and a circular tube shape are preferable, and a roll shape is more preferable because of excellent productivity of an article having a fine concavo-convex structure on the surface.

The aluminum substrate is preferably polished in order to smooth the surface.
Examples of the polishing method include mechanical polishing, chemical polishing, chemical mechanical polishing, robe polishing, and electrolytic polishing. One of these polishing methods may be used alone, or two or more thereof may be used in combination. Among these polishing methods, mechanical polishing and chemical mechanical polishing are preferable, and chemical mechanical polishing is more preferable because of excellent smoothness after processing.

  Since the oil used when processing the aluminum base material into a predetermined shape may adhere, it is preferable that the aluminum base material is degreased in advance before anodizing.

  97 mass%-99.9 mass% are preferable in 100 mass% of aluminum base materials, and the purity of aluminum of an aluminum base material has more preferable 99.5 mass%-99.9 mass%. When the purity of aluminum is 97% by mass or more, it is possible to suppress the formation of a fine concavo-convex structure having a size that scatters visible light due to segregation of impurities when anodized, and the rule of pores obtained by anodization It can suppress that property falls. Further, when the purity of aluminum is 99.9% by mass or less, the aluminum base material is not too soft and excellent in workability.

  In order to increase the strength of the aluminum substrate and improve the workability, it is preferable to contain a trace amount of magnesium in the aluminum substrate. 0.1 mass%-3 mass% are preferable in 100 mass% of aluminum base materials, and the purity of magnesium of an aluminum base material has more preferable 0.1 mass%-0.5 mass%.

(Process (b))
Step (b) is a first oxide film forming step of forming an oxide film having pores by anodizing the aluminum base material. That is, the step (b) is a step of anodizing the aluminum substrate in the treatment liquid. By immersing a part or all of the surface of the aluminum substrate in the treatment liquid and performing anodization, an oxide film can be formed on the portion immersed in the treatment liquid.

The thickness of the oxide film on the surface of the aluminum substrate in the step (b) is such that when the oxide film is removed in the step (c) described later, the machining marks on the surface of the aluminum substrate are sufficiently removed, and the grain boundary Are not so large as to be visually recognized, and it is possible to avoid transferring macro unevenness derived from machining to the surface of the molded body.
The thickness of the oxide film can be observed with a field emission scanning electron microscope or the like.

  The thickness of the oxide film on the surface of the aluminum substrate in the step (b) is proportional to the total amount of electricity consumed in the anodic oxidation. By adjusting the ratio of the total amount of electricity and the amount of electricity consumed for each voltage, the ratio between the thickness of the oxide film and the thickness of the oxide film formed by the initial anodic oxidation can be controlled.

  The voltage applied to the aluminum substrate in the step (b) is preferably 30V to 180V, more preferably 40V to 100V. When the voltage applied to the aluminum substrate in the step (b) is 40 V or more, an oxide film having a pore interval of 100 nm or more can be easily formed. When the voltage applied to the aluminum substrate in step (b) is 180 V or less, there is no need to maintain the treatment liquid at a low temperature or to inject a cooling liquid onto the back surface of the aluminum substrate, and the anode can be used with a simple device. Can be oxidized.

  The voltage applied to the aluminum substrate in the step (b) may be constant from the beginning to the end, and may be changed in the middle, but is changed in the middle because of the excellent regularity of the pores obtained by anodization. It is preferable. When changing the voltage in the middle, the voltage may be changed stepwise or the voltage may be changed continuously.

When the current density immediately after applying a voltage to the aluminum substrate in step (b) is 10 mA / cm ² or less, a maximum voltage of 40 V or more may be applied from the beginning, and initial anodization at a voltage of less than 40 V To increase the voltage stepwise or continuously, and finally adjust the voltage to be in the range of 40V to 180V.
Here, the maximum voltage means the maximum value of the voltage in the step (b) and coincides with the voltage at the end of the step (b).

  When increasing the voltage stepwise in the step (b), the voltage may be held for a certain period of time, or the voltage may be temporarily decreased. The certain time is preferably 1 to 10 minutes. When the voltage is temporarily reduced, the voltage may be temporarily 0 V. However, when the voltage becomes 0 V during the anodic oxidation, the electric field applied to the anode is eliminated, so the voltage is 0 V in the middle. When the voltage is increased and the electric field is applied again, the aluminum base material and the oxide film may be partially separated, and the thickness of the oxide film may become uneven. Therefore, it is preferable to perform anodic oxidation so that the voltage does not become 0 V in the middle.

  When the voltage is continuously increased in the step (b), the voltage boosting speed is preferably 0.05 V / s to 5 V / s. When the voltage boosting rate is 0.05 V / s or more, it is possible to prevent the oxide film from becoming too thick when the voltage is increased. Further, when the voltage boosting speed is 5 V / s or less, it is possible to suppress the burn that occurs due to an instantaneous increase in the current density flowing through the aluminum base material.

  When boosting from an arbitrary voltage to an arbitrary voltage in the step (b), the voltage may be increased instantaneously or gradually. The voltage boosting speed is preferably 0.05 V / s to 5 V / s. When the voltage boosting rate is 0.05 V / s or more, it is possible to prevent the oxide film from becoming too thick when the voltage is increased. Further, when the voltage boosting speed is 5 V / s or less, it is possible to suppress the burn that occurs due to an instantaneous increase in the current density flowing through the aluminum base material.

  The time for applying the voltage to the aluminum base material in the step (b) and performing the anodic oxidation is 3 seconds to 1800 since the thickness of the oxide film on the surface of the aluminum base material can be controlled to 0.5 μm to 10 μm. Second is preferable, and 30 seconds to 1000 seconds is more preferable.

(Process (c))
Step (c) is an oxide film removing step for removing a part of the oxide film. In order to remove a part of the oxide film, a voltage is not substantially applied to the aluminum substrate, and the aluminum substrate may be held while being immersed in the treatment liquid. After the step (b), the application of voltage is interrupted, and the aluminum substrate is held in the treatment liquid in which a plurality of acids are mixed in the same reaction tank, thereby allowing one of the oxide films formed in the step (b). Part can be dissolved and removed.
In the present invention, “substantially no voltage” means not only that the voltage applied to the aluminum substrate is 0 V, but also that the voltage does not flow to the aluminum substrate and the formation of the oxide film does not proceed. Including lowering.

  The holding time in the step (c) is preferably 5 minutes to 400 minutes. When the holding time in step (c) is 5 minutes or longer, the oxide film formed in step (b) can be sufficiently removed. In addition, when the holding time in the step (c) is 400 minutes or less, the regular structure formed in the step (b) can be prevented from being damaged, and the haze is not too high and the visibility of the article is excellent. Excellent mold productivity.

  When the holding time in the step (c) is less than 100 minutes, the formation of the second recess described later can be suppressed, and the transparency and antireflection performance of the article are excellent.

  In the case where the holding time in the step (c) is 100 minutes or longer, a second concave portion described later is formed, and thus the article has excellent antiglare property and antireflection performance.

The formation process of the second recess will be described below.
By dissolving and removing the oxide film formed in the step (b), a pinhole is formed at the bottom of the oxide film, the aluminum base material and the treatment liquid come into contact with each other, the aluminum starts to dissolve, and has a size larger than the pores. A second recess is formed. At this time, when the dissolution rate of the oxide film of the treatment liquid is higher than the dissolution rate of the aluminum base material, the second recess is formed before the oxide film is completely removed.

(Process (d))
Step (d) is a second oxide film forming step of forming an oxide film having pores by anodizing an aluminum substrate at a constant voltage. That is, the step (d) is a step of anodizing the aluminum substrate in the treatment liquid. By immersing a part or all of the surface of the aluminum substrate in the treatment liquid and performing anodization, an oxide film can be formed on the portion immersed in the treatment liquid.

The thickness of the oxide film on the surface of the aluminum substrate in the step (d) is preferably 0.01 μm to 0.4 μm. When the thickness of the oxide film on the surface of the aluminum substrate in the step (d) is 0.01 μm or more, the article has excellent antireflection performance. Moreover, it is excellent in the mold release property of a mold and articles | goods in the process (d) that the thickness of the oxide film on the surface of the aluminum base material is 0.4 micrometer or less.
The thickness of the oxide film can be observed with a field emission scanning electron microscope or the like.

  The thickness of the oxide film on the surface of the aluminum substrate in the step (d) is proportional to the total amount of electricity consumed in the anodic oxidation. By adjusting the ratio of the total amount of electricity and the amount of electricity consumed for each voltage, the ratio between the thickness of the oxide film and the thickness of the oxide film formed by the initial anodic oxidation can be controlled.

  The voltage applied to the aluminum substrate in the step (d) is preferably 30V to 180V, and more preferably 40V to 120V. When the voltage applied to the aluminum substrate in the step (d) is 40 V or more, an oxide film having a pore interval of 100 nm or more can be easily formed. When the voltage applied to the aluminum substrate in the step (d) is 180 V or less, it is not necessary to maintain the treatment liquid at a low temperature or to inject the cooling liquid onto the back surface of the aluminum substrate, and the anode can be used with a simple apparatus. Can be oxidized.

  The voltage applied to the aluminum substrate in the step (d) may be constant from the beginning to the end or may be changed in the middle. However, since the depth of the pores can be controlled, the voltage is constant from the beginning to the end. It is preferable to do. When changing the voltage in the middle, the voltage may be changed stepwise or the voltage may be changed continuously.

When the current density immediately after applying a voltage to the aluminum substrate in step (d) is 10 mA / cm ² or less, the highest voltage of 40 V or more may be applied from the beginning, and the initial anodic oxidation at a voltage of less than 40 V To increase the voltage stepwise or continuously, and finally adjust the voltage to be in the range of 40V to 180V.
Here, the maximum voltage means the maximum value of the voltage in the step (d) and coincides with the voltage at the end of the step (d).

  When increasing the voltage stepwise in the step (d), the voltage may be maintained for a certain period of time, or the voltage may be temporarily decreased. The certain time is preferably 1 to 10 minutes. When the voltage is temporarily reduced, the voltage may be temporarily 0 V. However, when the voltage becomes 0 V during the anodic oxidation, the electric field applied to the anode is eliminated, so the voltage is 0 V in the middle. When the voltage is increased and the electric field is applied again, the aluminum base material and the oxide film may be partially separated, and the thickness of the oxide film may become uneven. Therefore, it is preferable to perform anodic oxidation so that the voltage does not become 0 V in the middle.

  When the voltage is continuously increased in the step (d), the voltage boosting speed is preferably 0.05 V / s to 5 V / s. When the voltage boosting rate is 0.05 V / s or more, it is possible to prevent the oxide film from becoming too thick when the voltage is increased. Further, when the voltage boosting speed is 5 V / s or less, it is possible to suppress the burn that occurs due to an instantaneous increase in the current density flowing through the aluminum base material.

  When boosting from an arbitrary voltage to an arbitrary voltage in step (d), the voltage may be increased instantaneously or gradually. The voltage boosting speed is preferably 0.05 V / s to 5 V / s. When the voltage boosting rate is 0.05 V / s or more, it is possible to prevent the oxide film from becoming too thick when the voltage is increased. Further, when the voltage boosting speed is 5 V / s or less, it is possible to suppress the burn that occurs due to an instantaneous increase in the current density flowing through the aluminum base material.

  The time for applying the voltage to the aluminum substrate in the step (d) and performing the anodic oxidation is 3 seconds because the thickness of the oxide film on the surface of the aluminum substrate can be controlled to 0.01 μm to 0.4 μm. ˜600 seconds are preferable, and 5 seconds to 120 seconds are more preferable.

(Process (e))
Step (e) is a pore diameter expansion treatment step in which a part of the oxide film is removed to enlarge the pore diameter. In order to remove a part of the oxide film and enlarge the pore diameter, the voltage may not be substantially applied to the aluminum substrate, and the aluminum substrate may be kept immersed in the treatment liquid. After the step (d), the application of voltage is interrupted, and the aluminum base material is held in a treatment liquid in which a plurality of acids are mixed in the same reaction tank, whereby one of the oxide films formed in the step (d). The portion can be dissolved and removed, and the pore diameter can be enlarged.

  The holding temperature in the step (e) is preferably 5 ° C. to 40 ° C., more preferably 10 ° C. to 35 ° C., since the expansion rate of the pore diameter can be controlled and the pores can be easily tapered. preferable.

When the concentration of the second acid in the treatment liquid is 0.05 mol / l or more and less than 0.5 mol / l and the holding temperature in step (e) is less than 20 ° C., the holding time in step (e) is 30 minutes. -200 minutes are preferable and 45 minutes -180 minutes are preferable. If the holding time in step (e) is 30 minutes or longer, the pores can be tapered. Moreover, it is excellent in productivity of a mold in the holding time in a process (e) being 200 minutes or less.
When the concentration of the second acid in the treatment liquid is 0.05 mol / l or more and less than 0.5 mol / l and the holding temperature in the step (e) is 20 ° C. or more and less than 35 ° C., the holding time in the step (e) is 30 minutes to 180 minutes are preferable, and 45 minutes to 160 minutes are preferable. If the holding time in step (e) is 30 minutes or longer, the pores can be tapered. Moreover, it is excellent in productivity of a mold in the holding time in a process (e) being 180 minutes or less.

When the concentration of the second acid in the treatment liquid is 0.5 mol / l or more and the holding temperature in step (e) is less than 20 ° C., the holding time in step (e) is preferably 15 minutes to 200 minutes, 30 minutes to 120 minutes is preferable. If the holding time in step (e) is 15 minutes or longer, the pores can be tapered. Moreover, it is excellent in productivity of a mold in the holding time in a process (e) being 200 minutes or less.
When the concentration of the second acid in the treatment liquid is 0.5 mol / l or more and the holding temperature in step (e) is 20 ° C. or higher and lower than 35 ° C., the holding time in step (e) is 5 minutes to 120 minutes. 10 minutes to 100 minutes is preferable. If the holding time in step (e) is 5 minutes or longer, the pores can be tapered. Moreover, it is excellent in productivity of a mold in the holding time in a process (e) being 120 minutes or less.

(Process (f))
Step (f) is a step of alternately repeating step (d) and step (e).

The number of repetitions is preferably 3 times or more, more preferably 5 times or more, because the pores can be formed into a smooth taper shape and the antireflection performance of an article having a fine uneven structure obtained on the surface is excellent. The number of repetitions is preferably 10 times or less because of excellent mold productivity.
At the end of the step (f), a taper shape in which the pore diameter continuously changes can be formed, and the antireflection performance of an article having a fine uneven structure obtained on the surface is excellent. It is preferable to end with the pore diameter expansion treatment.

(Figure 1)
FIG. 1 is a schematic cross-sectional view showing an example of steps in the method for producing a mold of the present invention. Hereinafter, although the manufacturing method of the mold of this invention is demonstrated concretely using FIG. 1, the manufacturing method of the mold of this invention is not limited to the process shown in FIG.

First, the machined aluminum substrate 10 is immersed in a treatment liquid (step (a)), a voltage is applied, and the surface of the aluminum substrate 10 is anodized to form an oxide film 14 (step (b)). ). The pores 12 initially formed in the step (b) have low regularity and the pores 12 are randomly generated. When anodization is performed for a long time, the pores 12 gradually become deeper as the pores 12 become deeper. The regularity of the array period increases. Thereby, as shown in FIG. 1A, an oxide film 14 having a plurality of pores 12 arranged with high regularity can be formed on the surface of the aluminum base 10. After the step (b), at least a part of the oxide film 14 above the pores in which the pores 12 are randomly generated is removed (step (c)). Here, the second recess is formed at the bottom of the oxide film 14 simultaneously with the removal under the above-described conditions. Thereby, as shown in FIG. 1 (B), the pore generation points 16 arranged with high regularity can be formed on the surface of the aluminum base 10.
Next, a voltage is applied to the aluminum substrate 10 on which the pore generation points 16 are formed while being immersed in the treatment liquid (step (d)). Thereby, as shown in FIG. 1C, the aluminum substrate 10 is anodized, and the oxide film 14 having the plurality of pores 12 is formed again. And the application of the voltage to the aluminum base material 10 is interrupted, and the aluminum base material 10 is hold | maintained, being immersed in a process liquid (process (e)). Thereby, as shown in FIG. 1D, a part of the formed oxide film 14 is removed, and the pore diameter of the pores 12 is enlarged.
Thereafter, the step (d) of applying a voltage while being immersed in the treatment liquid and the step (e) of interrupting and holding the application of the voltage are alternately repeated (step (f)). Thereby, as shown in FIG.1 (E), the shape of the pore 12 can be made into the taper shape which a hole diameter shrink | contracts continuously in a depth direction from an opening part. As a result, it is possible to obtain a mold 18 in which an oxide film 14 composed of a plurality of periodic pores 12 is formed on the surface of the aluminum substrate 10.
As described above, since the same kind of treatment liquid is used in each of the steps (a) to (f), an anodic oxidation step for forming an oxide film on the surface of the aluminum base, and an oxide film for removing a part of the oxide film All the steps of the removal step and the etching step of enlarging the pores formed in the oxide film can be performed in one reaction tank, the manufacturing equipment is simplified and the productivity of the mold is excellent.

(Mold recess)
Examples of the shape of the pore (first concave portion) include a substantially conical shape, a pyramid shape, a bell shape, and a cylindrical shape. Among these pore shapes, the anti-reflective performance of the article having the fine concavo-convex structure obtained on the surface is excellent, so that the shape in the direction perpendicular to the depth direction, such as a cone shape, a pyramid shape, a bell shape, etc. A shape in which the hole cross-sectional area continuously decreases from the outermost surface in the depth direction is preferable, and a conical shape, a pyramid shape, and a bell shape are more preferable.

  The average distance between adjacent pores (first recesses) is preferably less than the wavelength of visible light, that is, 400 nm or less, since it is excellent in the antireflection performance of an article having a fine uneven structure obtained on the surface. Is more preferable.

  The average distance between adjacent pores (first recesses) is preferably 20 nm to 300 nm, and more preferably 80 nm to 200 nm. When the average interval between adjacent pores is 20 nm or more, the projections are easily formed when the projections are formed by transferring the pores. Moreover, the voltage for enlarging a pore space | interval can be suppressed as the average space | interval between adjacent pores is 300 nm or less, and it is easy to manufacture anodized porous alumina industrially.

  In this specification, the average interval between adjacent pores is 10 points at random by using an electron microscope to determine the interval between adjacent pores (the distance from the center of the pore to the center of the adjacent pore). (However, the place where the second concave portion does not exist) is measured, and these values are averaged.

  The average depth of the pores (first recesses) is preferably 60 nm to 400 nm, and more preferably 90 nm to 350 nm. When the average depth of the pores is 60 nm or more, an increase in the minimum reflectance or the reflectance at a specific wavelength can be suppressed, and the antireflection performance of an article having a fine uneven structure on the surface is excellent. Further, when the average depth of the pores is 400 nm or less, the pores are easily formed, and the article having the fine concavo-convex structure obtained on the surface is excellent in scratch resistance.

  In this specification, the average depth of the pores is determined by randomly measuring the vertical distance between the bottom of the pores and the top of the convex portions existing between the pores using an electron microscope at 10 points. These values are averaged.

  The aspect ratio of pores (average depth of pores / average interval between adjacent pores) is preferably 0.8 to 5.0, more preferably 1.2 to 4.0, and 1.5 to 3 0.0 is more preferable. When the aspect ratio of the pores is 0.8 or more, the antireflection performance of an article having a fine uneven structure on the surface is excellent. Further, when the aspect ratio of the pores is 5.0 or less, the pores are easily formed, and the article having the fine concavo-convex structure obtained on the surface is excellent in scratch resistance.

  When forming the second recess, the average diameter of the second recess is preferably 0.5 μm to 50 μm, and more preferably 1 μm to 30 μm. When the average diameter of the second concave portion is 0.5 μm or more, the antiglare property of the article having the fine concavo-convex structure obtained on the surface is excellent. In addition, when the average diameter of the second recess is 50 μm or less, the haze is not excessively increased and the visibility of the article is excellent.

  In the present specification, the average diameter of the second concave portion is obtained by randomly extracting 10 points of the second concave portion using a laser microscope, measuring the longest length of the opening, and averaging these values. Value.

  When forming the second recess, the average depth of the second recess is preferably 0.1 μm to 3.0 μm, and more preferably 0.3 μm to 1.5 μm. When the average depth of the second recess is 0.1 μm or more, the antiglare property of the article having the obtained fine uneven structure on the surface is excellent. In addition, when the average depth of the second recess is 3.0 μm or less, the haze is not excessively increased and the visibility of the article is excellent.

  In this specification, the average depth of the second recess is determined by randomly measuring 10 vertical distances between the bottom and the opening of the second recess using a laser microscope. The average value.

  The aspect ratio of the second recess (average depth of the second recess / average diameter of the second recess) is preferably 0.02 to 3, and more preferably 0.1 to 2. When the aspect ratio of the second recess is 0.02 or more, the antiglare property of the article having the fine concavo-convex structure obtained on the surface is excellent. Moreover, when the aspect ratio of the second recess is 3 or less, the mechanical strength of an article having the obtained fine uneven structure on the surface is excellent.

(Manufacturing method of article having fine concavo-convex structure on its surface)
Since the method for producing an article having the fine concavo-convex structure on the surface thereof according to the present invention is excellent in the productivity of the article, a curable composition is supplied to the surface of the mold obtained by the method for producing a mold of the present invention, and the curability is increased. A method of curing the composition to obtain an article is preferred. Specifically, since it is excellent in the productivity of the article, a curable composition is sandwiched between the mold and the base material on the surface of the mold obtained by the method for producing a mold of the present invention, and active energy rays are added to this. A method of obtaining an article by irradiating is cured.

(Base material)
Examples of the base material include acrylic resins such as polymethyl methacrylate; polycarbonate resins; styrene resins such as polystyrene and methyl methacrylate-styrene copolymers; cellulose resins such as cellulose diacetate, cellulose triacetate, and cellulose acetate butyrate; Polyester resin such as polyethylene terephthalate; Polyamide resin; Polyimide resin; Polyether sulfone resin; Polysulfone resin; Polyolefin resin such as polypropylene, polymethylpentene, and alicyclic polyolefin; Vinyl chloride resin such as polyvinyl chloride; Polyvinyl acetal resin; Polyetherketone resin; polyurethane resin; glass and the like. Among these materials for the base material, acrylic resin, polycarbonate resin, polyester resin, and cellulose resin are preferable, and polyester resin and cellulose resin are more preferable because of excellent light transmittance and handling properties.

  Examples of the form of the substrate include known forms such as a film and a sheet. Among these forms of base materials, films and sheets are preferred because of excellent product productivity and handleability.

  As a manufacturing method of a base material, well-known manufacturing methods, such as an injection molding method, an extrusion molding method, a cast molding method, etc. are mentioned, for example. Among these methods for producing a substrate, an extrusion molding method and a cast molding method are preferable because of excellent productivity.

  The surface of the base material may be subjected to coating treatment, corona treatment, etc. for the purpose of improving properties such as adhesion, antistatic properties, scratch resistance, and weather resistance.

  The refractive index difference between the cured product of the curable composition and the substrate can suppress light reflection at the interface between the cured product layer of the curable composition and the substrate, and optical performance such as antireflection performance. Is preferably 0.3 or less, more preferably 0.1 or less.

(Curable composition)
Since the curable composition is excellent in the productivity of an article, a composition that is cured by active energy rays is preferable.
Examples of the active energy rays include visible light, ultraviolet rays, electron beams, plasma, heat rays (infrared rays, etc.) and the like. Among these active energy rays, ultraviolet rays and electron beams are preferred, and ultraviolet rays are more preferred because of the excellent curability of the curable composition.

  It is preferable that a curable composition contains a polymeric compound, a polymerization initiator, and another additive as needed.

(Polymerizable compound)
Examples of the polymerizable compound include monomers, oligomers, reactive polymers, and the like that include at least one of a radical polymerizable bond and a cationic polymerizable bond in the molecule. These polymerizable compounds may be used alone or in combination of two or more.

  Examples of the monomer having a radical polymerizable bond include a monofunctional monomer and a polyfunctional monomer.

Examples of the monofunctional monomer 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, dodecyl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, alkyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) Acrylate, phenoxyethyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, allyl (meth) acrylate, 2-hydroxy (Meth) acrylate derivatives such as til (meth) acrylate, hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate; (meth) acrylic acid; (meth) acrylonitrile; styrene Styrene derivatives such as α-methylstyrene; (meth) acrylamide derivatives such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, etc. Is mentioned. These monofunctional monomers may be used individually by 1 type, and may use 2 or more types together. Among these monofunctional monomers, alkyl (meth) acrylate, N, N-dimethyl (meth) acrylamide, 2-hydroxyethyl (meth) is excellent because of excellent adhesion between the cured product of the curable composition and the substrate. Acrylate is preferable, and alkyl acrylate, N, N-dimethylacrylamide, and 2-hydroxyethyl acrylate are more preferable.
In this specification, (meth) acryl refers to acryl, methacryl or both.

  Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, isocyanuric acid ethylene oxide modified di (meth) acrylate, and 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) acryloxy Toxiphenyl) propane, 2,2-bis (4- (3- (meth) acryloxy-2-hydroxypropoxy) phenyl) propane, 1,2-bis (3- (meth) acryloxy-2-hydroxypropoxy) ethane, 1,4-bis (3- (meth) acryloxy-2-hydroxypropoxy) butane, dimethyloltricyclodecane di (meth) acrylate, ethylene oxide adduct of bisphenol A di (meth) acrylate, propylene oxide addition of bisphenol A Bifunctional monomers such as di (meth) acrylate, neopentyl glycol hydroxypivalate di (meth) acrylate, divinylbenzene, methylenebisacrylamide; pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) Trifunctional monomers such as acrylate, trimethylolpropane ethylene oxide modified 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, pentaerythritol tetra (meth) acrylate, dipentaerythrole hexa (meth) acrylate, dipentaerystol penta (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) Tetrafunctional or higher functional groups such as acrylate, ditrimethylolpropane tetraacrylate, tetramethylolmethane tetra (meth) acrylate, etc. Monomers above: bifunctional or higher urethane acrylates, bifunctional or higher polyester acrylates, and the like. These polyfunctional monomers may be used individually by 1 type, and may use 2 or more types together. Among these polyfunctional monomers, since the mechanical strength of the cured product of the curable composition is excellent, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipenta Erythritol hexa (meth) acrylate, ethylene oxide modified dipentaerythritol hexa (meth) acrylate, polyethylene glycol di (meth) acrylate are preferred, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate , Ethylene oxide modified dipentaerythritol hexaacrylate, polyethylene glycol diacrylate Ri preferred.

  Examples of the monomer having a cationic polymerizable bond include monomers having an epoxy group, an oxetanyl group, an oxazolyl group, a vinyloxy group, and the like. These monomers having a cationic polymerizable bond may be used alone or in combination of two or more. Among these monomers having a cationic polymerizable bond, a monomer having an epoxy group is preferable because the reactivity of the curable composition is excellent.

  Specific examples of the monomer having a cationic polymerizable bond include, for example, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, and polypropylene glycol diglycidyl ether. Neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol A diglycidyl ether, bisphenol A polypropylene oxide 2 mol adduct diglycidyl ether, 3-ethyl-3-hydroxymethyloxetane, 2-ethylhexyl Xetane, xylylenebisoxetane, 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, 2-ethylhexyl vinyl ether Etc. These monomers having a cationic polymerizable bond may be used alone or in combination of two or more.

  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 ( Examples thereof include a meth) acrylate, a urethane (meth) acrylate, a cationic polymerization type epoxy compound, a homopolymer or a copolymer of the above-described monomer having a radical polymerizable group in the side chain. These oligomers or reactive polymers may be used alone or in combination of two or more.

  Since the combination of the polymerizable compounds is excellent in the reactivity of the curable composition, a combination of monomers having a radical polymerizable bond, a combination of a monomer having a radical polymerizable bond and a monomer having a cationic polymerizable bond is preferable. A combination of monomers having a radical polymerizable bond is more preferable.

(Polymerization initiator)
When using a photocuring reaction in the case of hardening of a curable composition, it is good to use a photoinitiator as a polymerization initiator.
Examples of the photopolymerization initiator 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, methylphenylglyoxylate, ethylphenylglyoxylate, 4,4′-bis (dimethylamino) benzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy- Carbonyl compounds such as cyclohexyl phenyl ketone; sulfur compounds such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; 2,4,6-trimethylbenzoyldiphenylphosphine And acyl phosphine oxides such as bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. These photoinitiators may be used individually by 1 type, and may use 2 or more types together. Among these photopolymerization initiators, since the curability of the curable composition is excellent, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2, 4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide are preferred, 1-hydroxy-cyclohexyl-phenyl-ketone, bis (2,4,6-trimethylbenzoyl) ) -Phenylphosphine oxide is more preferred.

When a thermosetting reaction is used in curing the curable composition, a thermal polymerization initiator may be used as the polymerization initiator.
Examples of the thermal polymerization initiator include methyl ethyl ketone peroxide, benzoyl peroxide, dicumyl peroxide, t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxy octoate, t-butyl peroxybenzoate, lauroyl. Organic peroxides such as peroxides; Azo compounds such as azobisisobutyronitrile; Redox in which the organic peroxides are combined with amines such as N, N-dimethylaniline and N, N-dimethyl-p-toluidine A polymerization initiator etc. are mentioned. These thermal polymerization initiators may be used individually by 1 type, and may use 2 or more types together. Among these thermal polymerization initiators, an organic peroxide and an azo compound are preferable because the reaction temperature is moderate, and an azo compound is more preferable.

  As for content of a polymerization initiator, 0.1 mass part-10 mass parts are preferable with respect to 100 mass parts of polymeric compounds. When the content of the polymerization initiator is 0.1 parts by mass or more, the polymerization is likely to proceed. Moreover, it is excellent in the mechanical strength of hardened | cured material as content of a polymerization initiator is 10 mass% or less, and coloring of hardened | cured material can be suppressed.

(Other additives)
The curable composition may contain other additives as necessary in addition to the polymerizable compound and the polymerization initiator.
Other additives include, for example, release agents, non-reactive polymers, active energy ray sol-gel reactive compositions, antistatic agents, additives such as fluorine compounds for improving antifouling properties, fine particles, small amounts of A solvent etc. are mentioned. These other additives may be used alone or in combination of two or more.

(Release agent)
Since the curable composition can improve continuous transferability, it preferably contains a release agent.
A mold release agent improves the mold release property of the hardened | cured material of a curable composition, and a mold surface, and if it has compatibility with a curable composition, it will not specifically limit.

  Examples of the release agent include (poly) oxyalkylene alkyl phosphate compounds, phosphate ester compounds, fluorine-containing compounds, silicone compounds, compounds having a long-chain alkyl group, solid wax (polyalkylene wax, amide wax, Teflon (trade name) powder, etc.). These mold release agents may be used individually by 1 type, and may use 2 or more types together. Among these release agents, a (poly) oxyalkylene alkyl phosphate compound is preferable because of excellent release properties.

  The content of the release agent in the curable composition is preferably 0.01 parts by mass to 1 part by mass, more preferably 0.05 parts by mass to 0.5 parts by mass with respect to 100 parts by mass of the polymerizable compound. 0.05 parts by mass to 0.1 parts by mass is more preferable. When the content of the release agent in the curable composition is 0.01 parts by mass or more, the release property between the cured product and the mold is excellent. Moreover, the fall of the performance of the articles | goods obtained as it is 1 mass part or less can be suppressed.

(Non-reactive polymer)
The curable composition preferably contains a non-reactive polymer because the molecular weight of the cured product can be controlled.
Examples of the non-reactive polymer include acrylic resins, styrene resins, polyurethane, cellulose resins, polyvinyl butyral, polyester, and thermoplastic elastomers. These non-reactive polymers may be used alone or in combination of two or more. Among these non-reactive polymers, an acrylic resin is preferable because it has a refractive index close to that of a cured product of a (meth) acrylic monomer.

(Active energy ray sol-gel reactive composition)
Since the curable composition is excellent in the mechanical strength of the cured product, the curable composition preferably contains an active energy ray sol-gel reactive composition.
Examples of the active energy ray sol-gel reactive composition include alkoxysilane compounds and alkylsilicate compounds. These active energy ray sol-gel reactive compositions may be used individually by 1 type, and may use 2 or more types together.

  Examples of the alkoxysilane compound include tetramethoxysilane, tetra-i-propoxysilane, tetra-n-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-t-butoxysilane, and methyltriethoxy. Examples include silane, methyltripropoxysilane, methyltributoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, trimethylmethoxysilane, trimethylpropoxysilane, and trimethylbutoxysilane. These alkoxysilane compounds may be used individually by 1 type, and may use 2 or more types together.

  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. These alkyl silicate compounds may be used individually by 1 type, and may use 2 or more types together.

(Water repellent / hydrophilic)
Articles having a fine concavo-convex structure on the surface can obtain super water repellency if the surface is made of a hydrophobic material due to the lotus effect, and super hydrophilic if the surface is made of a hydrophilic material. Is obtained.

When imparting water repellency to the surface of an article having a fine concavo-convex structure on the surface (specifically, when the contact angle between the fine concavo-convex structure and water is 90 ° or more), the surface is formed of a hydrophobic material. The
The raw material for the hydrophobic material is preferably a fluorine-containing compound or a silicone compound because of excellent water repellency.

When hydrophilicity is imparted to an article having a fine concavo-convex structure on its surface (specifically, the contact angle between the fine concavo-convex structure and water is 25 ° or less), the surface is formed of a hydrophilic material.
The raw material of the hydrophilic material preferably includes at least a hydrophilic monomer because it is excellent in hydrophilicity, and more preferably includes a cross-linkable polyfunctional monomer because it is excellent in scratch resistance and water resistance. . The hydrophilic monomer and the crosslinkable polyfunctional monomer may be the same or different.
Specifically, since the raw material of the hydrophilic material is excellent in scratch resistance, a polyfunctional (meth) acrylate having 4 or more functions, a hydrophilic (meth) acrylate having 2 or more functions, and a monofunctional as necessary. It is preferable to include a monomer.

  Specific examples of the curable composition include the compositions described in JP2013-175733A and JP2015-129947A.

The viscosity of the curable composition is preferably 10,000 mPa · s or less, more preferably 5000 mPa · s or less, and even more preferably 2000 mPa · s or less because the curable composition has excellent followability to a fine concavo-convex structure.
In this specification, the viscosity of the curable composition is a value measured at 25 ° C. using a rotary E-type viscometer.

(Manufacturing apparatus for articles having a fine concavo-convex structure on the surface)
A method for obtaining an article by sandwiching a curable composition on the surface of a mold obtained by the method for producing a mold of the present invention between a mold and a base material and irradiating it with an active energy ray to cure the article, Therefore, it is preferable to use the manufacturing apparatus shown in FIG.
FIG. 2 is a schematic cross-sectional view showing an apparatus for manufacturing an article having a fine relief structure on the surface. Hereinafter, although the manufacturing method of the article | item which has a fine concavo-convex structure on the surface is demonstrated using FIG. 2, the manufacturing method of the article | item which has a fine concavo-convex structure on the surface is not limited to FIG.

A method for manufacturing an article having a fine concavo-convex structure on the surface using the manufacturing apparatus shown in FIG. 2 is as follows.
Between the roll-shaped mold 20 provided with the reverse structure of the fine concavo-convex structure on the surface and the belt-shaped base material 42 that moves along the surface of the roll-shaped mold 20 in synchronization with the rotation of the roll-shaped mold 20. The curable composition 38 is supplied from the tank 22. The base material 42 and the curable composition 38 are nipped between the roll-shaped mold 20 and the nip roll 26 whose nip pressure is adjusted by the pneumatic cylinder 24, and the curable composition 38 is transferred to the base material 42 and the roll. At the same time, it is filled in the recesses of the roll-shaped mold 20. By irradiating the curable composition 38 with the active energy ray from the active energy ray irradiating device 28 installed outside the roll-shaped mold 20 through the base material 42 and curing the curable composition 38, A cured resin layer 44 to which the fine uneven structure on the surface of the mold 20 is transferred is formed.
By peeling the base material 42 having the cured resin layer 44 formed on the surface from the roll-shaped mold 20 by the peeling roll 30, an article 40 having a fine concavo-convex structure on the surface is obtained.

  Examples of the active energy ray irradiation device include a chemical lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, an electrodeless ultraviolet lamp, a visible light halogen lamp, a xenon lamp, and an ultraviolet LED. Among these active energy ray irradiation apparatuses, an electrodeless ultraviolet lamp and an ultraviolet LED are preferable because heat generation can be suppressed.

Irradiation energy amount is ^{preferably 100mJ / cm 2 ~10000mJ / cm 2} , 200mJ / cm 2 ~5000mJ / cm 2 is more preferable. When the light irradiation energy amount is 100 mJ / cm ² or more, the curability of the curable composition is excellent. Moreover, coloring of hardened | cured material can be suppressed as light irradiation energy amount is 10000 mJ / cm < ² > or less.

(Articles with fine concavo-convex structure on the surface)
By the method for manufacturing an article having the fine uneven structure on the surface of the present invention, for example, an article having the fine uneven structure shown in FIG. 3 on the surface is obtained. Hereinafter, the article having the fine concavo-convex structure on the surface obtained by the method for producing the article having the fine concavo-convex structure of the present invention on the surface will be described with reference to FIG. The article having a fine relief structure on the surface obtained by the method is not limited to FIG.

  FIG. 3 is a schematic cross-sectional view showing an example of an article having a fine relief structure on the surface. 3 has a cured resin layer 44 on a substrate 42, and the cured resin layer 44 has a plurality of convex portions 46.

(Convex part of article having fine uneven structure on the surface)
Examples of the shape of the first convex portion include a substantially conical shape, a pyramid shape, a bell shape, and a cylindrical shape. Among the shapes of these first convex portions, since the antireflective performance of the article having the fine concavo-convex structure obtained on the surface is excellent, it is orthogonal to the height direction, such as a cone shape, a pyramid shape, a bell shape, etc. A shape in which the cross-sectional area of the convex portion continuously increases in the depth direction from the top is preferable, and a conical shape, a pyramid shape, and a bell shape are more preferable.
The first convex portion may be one in which a plurality of fine first convex portions are united to form one convex portion.
In this specification, let the 1st convex part be the convex part which transferred the pore (1st crevice) mentioned above.

  The average distance between the adjacent first convex portions is excellent in the antireflection performance of the article having the resulting fine concavo-convex structure on the surface, and is therefore not more than the wavelength of visible light, that is, not more than 400 nm, and more preferably not more than 380 nm. .

  The average distance between adjacent first convex portions is preferably 20 nm to 300 nm, and more preferably 80 nm to 200 nm. When the average interval between the adjacent first convex portions is 20 nm or more, the convex portions are easily formed when the fine portions are transferred to form the convex portions. Moreover, the voltage for enlarging a pore space | interval can be suppressed as the average space | interval between adjacent 1st convex parts is 300 nm or less, and it is easy to manufacture anodized porous alumina industrially.

  In this specification, the average interval between the adjacent first convex portions is the interval between the adjacent first convex portions (the first convex portion adjacent from the center of the first convex portion using an electron microscope). 10 points (however, the place where the second convex portion does not exist) is measured at random, and the values are averaged.

  The average height of the first protrusions is preferably 60 nm to 400 nm, and more preferably 90 nm to 350 nm. When the average height of the first protrusions is 60 nm or more, an increase in the minimum reflectance and the reflectance at a specific wavelength can be suppressed, and the antireflection performance of an article having a fine uneven structure on the surface is excellent. . In addition, when the average height of the first protrusions is 400 nm or less, pores are easily formed, and the article having a fine uneven structure on the surface is excellent in scratch resistance.

  In this specification, the average height of the first convex portion is the vertical distance between the top of the first convex portion and the bottom of the concave portion existing between the first convex portions using an electron microscope. 10 points are measured at random, and these values are averaged.

  The aspect ratio of the first protrusions (average height of the first protrusions / average interval between adjacent first protrusions) is preferably 0.8 to 5.0, and 1.2 to 4.0. Is more preferable, and 1.5 to 3.0 is even more preferable. When the aspect ratio of the first convex portion is 0.8 or more, the antireflection performance of an article having the obtained fine uneven structure on the surface is excellent. Further, when the aspect ratio of the first convex portion is 5.0 or less, pores are easily formed, and the article having the fine concavo-convex structure obtained on the surface is excellent in scratch resistance.

In the case of forming the second convex portion, the average diameter of the second convex portion is preferably 0.5 μm to 50 μm, and more preferably 1 μm to 30 μm. When the average diameter of the second protrusions is 0.5 μm or more, the antiglare property of the article having the fine uneven structure obtained on the surface is excellent. In addition, when the average diameter of the second convex portion is 50 μm or less, the haze is not excessively increased and the visibility of the article is excellent.
In the present specification, the second convex portion is a convex portion obtained by transferring the above-described second concave portion.

  In this specification, the average diameter of the second convex portion is obtained by randomly extracting 10 points of the second convex portion using a laser microscope, measuring the longest length of the opening, and calculating these values. The average value.

  When forming the second convex portion, the average height of the second convex portion is preferably 0.1 μm to 3.0 μm, and more preferably 0.3 μm to 1.5 μm. When the average height of the second protrusions is 0.1 μm or more, the antiglare property of the article having the resulting fine uneven structure on the surface is excellent. In addition, when the average height of the second convex portions is 3.0 μm or less, the haze is not excessively increased and the visibility of the article is excellent.

  In this specification, the average height of the second convex portion is the vertical distance between the top of the second convex portion and the bottom of the concave portion existing between the second convex portions using a laser microscope. 10 points are measured at random, and these values are averaged.

  The aspect ratio of the second convex part (average depth of the second convex part / average diameter of the second convex part) is preferably 0.02 to 3, and more preferably 0.1 to 2. When the aspect ratio of the second convex portion is 0.02 or more, the antiglare property of the article having the fine concavo-convex structure obtained on the surface is excellent. In addition, when the aspect ratio of the second convex portion is 3 or less, the mechanical strength of an article having the obtained fine uneven structure on the surface is excellent.

  When water repellency is imparted to the surface of an article having a fine concavo-convex structure, the contact angle between the fine concavo-convex structure and water is less than 90 ° because water stains are difficult to adhere and icing can be suppressed. Preferably, it is 110 ° or more, more preferably 120 ° or more.

  When imparting hydrophilicity to the surface of an article having a fine concavo-convex structure on the surface, the contact angle between the fine concavo-convex structure and water is preferably 25 ° or less, because it can be washed with water and oil stains are less likely to adhere, The following is more preferable, and 21 ° or more is more preferable. In addition, when imparting hydrophilicity to the surface of an article having a fine concavo-convex structure on the surface, the contact angle between the fine concavo-convex structure and water can suppress deformation of the fine concavo-convex structure and an increase in reflectance. It is preferably at least °.

(Use)
Articles having a fine concavo-convex structure on the surface have various performances such as antireflection performance, antiglare performance, water repellency performance, and hydrophilic performance.
When an article having a fine concavo-convex structure on the surface is in the form of a sheet or film, it is attached to the surface of an object such as an image display device such as a television or a mobile phone display, an exhibition panel, a meter panel, etc. Or insert molding. In addition, taking advantage of its water-repellent performance, it can also be used as a member for objects that may be exposed to rain, water, steam, etc., such as bathroom windows and mirrors, solar cell members, automobile mirrors, signboards, and glasses lenses. Can be used.
When an article having a fine concavo-convex structure on its surface is a three-dimensional shape, an antireflection article is manufactured using a transparent substrate having a shape according to the application, and this can be used as a member constituting the surface of the object. it can.
When the object is an image display device, not only the surface thereof, but also an article having a fine concavo-convex structure on the surface may be attached to the front plate, or the front plate itself may be attached to the surface with the fine concavo-convex structure. It can also be comprised from the article which has. For example, an article having a fine concavo-convex structure on the surface of a rod lens array attached to a sensor array for reading an image, a cover glass of an image sensor such as a FAX, a copying machine or a scanner, or a contact glass for placing an original of a copying machine May be used. Further, by using an article having a fine concavo-convex structure on the surface of a light receiving portion of an optical communication device such as visible light communication, signal reception sensitivity can be improved.
In addition to the above-described uses, for example, it can also be used for optical uses such as optical waveguides, relief holograms, optical lenses, and polarization separation elements, and for cell culture sheets.

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

(Measurement of mold recesses and article protrusions)
The average interval and the average depth of the first concave portions of the molds obtained in the examples and comparative examples, and the average interval and the average height of the first convex portions of the articles obtained in the examples and comparative examples are electrolytically discharged. Using a scanning electron microscope (model name “JSM-6701F”, manufactured by JEOL Ltd.), 10 points were measured randomly under the condition of an acceleration voltage of 3.0 kV, and these values were averaged.

  The average diameter and average depth of the second concave portions of the molds obtained in the examples and comparative examples, and the average diameter and average height of the second convex portions of the articles obtained in the examples and comparative examples were measured with a laser microscope. (Model name “VK-X100”, manufactured by Shimadzu Corporation) was used to randomly measure 10 points and average these values.

(Reflectance measurement)
In accordance with JIS Z8722, the spectrophotometer (model name “UV-2450”, manufactured by Shimadzu Corporation) was used to measure the reflectance of the articles obtained in the examples and comparative examples, and these items were measured. A value obtained by averaging the values was taken as a measured value, and evaluated according to the following evaluation criteria.
A: The reflectance was less than 1.00.
B: The reflectance was 1.00 or more.

(Haze measurement)
Based on ISO13468-1, the articles obtained in Examples and Comparative Examples were measured at three points using a haze meter (model name “NDH2000”, manufactured by Nippon Denshoku Industries Co., Ltd.). A value obtained by averaging was used as a measured value, and evaluated according to the following evaluation criteria.
A: The haze was 1.0 or more and 30.0 or less.
B: The haze was less than 1.0 or more than 30.0.

(Anti-glare evaluation)
The articles obtained in the examples and comparative examples were irradiated with a fluorescent lamp having a luminance of 8000 cd / m ² from a direction of 45 °, and a reflected image was visually observed from the direction of −45 °, and the following evaluation criteria were used. evaluated.
A: The outline of the fluorescent lamp cannot be almost visually recognized.
B: The outline of the fluorescent lamp can be clearly seen.

[Example 1]
(Mold production)
Aluminum is cut into a cylindrical shape having an outer diameter of 205 mm, an inner diameter of 155 mm, and a width of 350 mm, and the surface is subjected to mirror cutting so that the arithmetic average roughness Ra of the processed surface is 0.03 μm or less. The surface was mirror-polished so that the arithmetic average roughness Ra was 0.002 μm or less to obtain a cylindrical aluminum substrate.

Subsequently, the processing liquid which mixed 0.1 mol / l oxalic acid aqueous solution and 1.0 mol / l phosphoric acid aqueous solution was temperature-controlled at 23 degreeC, and the aluminum base material obtained by this was immersed. (Process (a))
Next, the aluminum substrate was anodized at 40 V for 600 seconds to form an oxide film having pores on the surface of the aluminum substrate. (Process (b))
Next, the application of voltage to the aluminum base material having an oxide film formed on the surface is interrupted, and the oxide film is dissolved and removed by holding it in the treatment liquid for 120 minutes to form a pit that becomes a pore generation point of anodic oxidation. While exposing, the 2nd recessed part was formed.
Next, the aluminum substrate was anodized at 40 V for 60 seconds to form an oxide film having pores on the surface of the aluminum substrate. (Process (d))
Next, the application of voltage to the aluminum base material with an oxide film formed on the surface is interrupted, and the oxide film is held for 25 minutes to dissolve and remove part of the oxide film, and the pore diameter of the oxide film is enlarged. It was. (Process (e))
Next, the step (d) and the step (e) were repeated alternately four times, and finally the step (e) was performed. (Process (f))
In addition, all the processes of process (a)-process (f) were performed in the same reaction tank. Moreover, the process (d) and the process (e) were each performed 5 times in total.

Thereafter, the aluminum substrate was washed with deionized water, and the water on the surface was further removed by air blowing to obtain a roll-shaped mold in which an oxide film having substantially conical shape, that is, tapered pores was formed. .
The obtained mold had an average interval between the first recesses of 100 nm, an average depth of the first recesses of 200 nm, an average diameter of the second recesses of 1.5 μm, and an average depth of the second recesses of 1.5 μm. .

(Preparation of curable composition)
25 parts by mass of dipentaerythritol hexaacrylate, 25 parts by mass of pentaerythritol triacrylate, 25 parts by mass of ethylene oxide-modified dipentaerythritol hexaacrylate, 25 parts by mass of polyethylene glycol diacrylate, 1 part by mass of 1-hydroxycyclohexyl phenyl ketone, bis (2 , 4,6, -trimethylbenzoyl)? Phenylphosphine oxide and 0.1 part by mass of polyoxyethylene alkyl (12-15) ether phosphoric acid were mixed to obtain a curable composition.

(Manufacture of goods)
The obtained roll-shaped mold was installed in the manufacturing apparatus shown in FIG. Roll-shaped mold and belt-shaped base material (trade name “A4300”, manufactured by Toyobo Co., Ltd.) that moves along the surface of the roll-shaped mold in synchronization with the rotation of the roll-shaped mold (speed 7 m / min) The curable composition obtained from the tank is supplied between the polyethylene terephthalate film). The substrate and the curable composition are nipped between the roll-shaped mold and the nip roll whose nip pressure is adjusted by the pneumatic cylinder, and the curable composition is placed between the substrate and the roll-shaped mold. At the same time, it is filled in the recesses of the roll-shaped mold. The surface of the roll-shaped mold is obtained by irradiating the curable composition with ultraviolet rays through a substrate from an ultraviolet irradiation device (output 240 W / cm) installed outside the roll-shaped mold to cure the curable composition. The cured resin layer to which the fine uneven structure is transferred is formed.
An article having a fine concavo-convex structure on the surface was obtained by peeling the substrate having a cured resin layer formed on the surface from the roll-shaped mold with a peeling roll.
The obtained article has an average interval between the first protrusions of 100 nm, an average height of the first protrusions of 200 nm, an average diameter of the second protrusions of 1.5 μm, an average height of the second protrusions of 1. It was 5 μm.
Table 2 shows the evaluation results of the obtained articles.

[Examples 2 to 4]
Except having changed the conditions of process (a)-process (f) like Table 1, it operated similarly to Example 1 and obtained the article | item which has a fine uneven structure on the surface.
Table 2 shows the evaluation results of the obtained articles.

[Comparative Example 1]
The temperature of the treatment liquid in step (a) was adjusted to 15.7 ° C., and the treatment liquid used in steps (a) to (b) was used in 0.3 mol / l oxalic acid aqueous solution, step (c). The treatment liquid was the same as in Example 1 except that the aqueous solution obtained by mixing the 1.8% by mass chromic acid aqueous solution and the 6% by mass phosphoric acid aqueous solution and the temperature of the treatment liquid in step (c) was adjusted to 70 ° C. Then, an article having a fine concavo-convex structure on the surface was obtained.
The obtained article had an average interval between the first protrusions of 100 nm and an average height of the first protrusions of 200 nm, and no second protrusions were present.
It should be noted that the reaction vessels used in the steps (a) to (b), the reaction vessels used in the step (c), and the reaction vessels used in the steps (d) to (f) are different from each other. Was used.
Table 2 shows the evaluation results of the obtained articles.

The molds in Examples 1 to 4 can be manufactured in the same reaction tank, whereas the molds in Comparative Example 1 cannot be manufactured in the same reaction tank because the treatment liquid used varies depending on the process. It was.
Moreover, since the articles | goods obtained in Examples 1-4 had the 1st convex part and the 2nd convex part, they were excellent in antireflection performance and anti-glare property. On the other hand, the article obtained in Comparative Example 1 was not formed with the second concave portion in the step (c) and had only the first convex portion, and thus was excellent in antireflection performance, but was inferior in antiglare property.

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 Pneumatic cylinder 26 Nip roll 28 Active energy ray irradiation apparatus 30 Peeling roll 38 Curable composition 40 With fine uneven structure on the surface Article 42 Base Material 44 Cured Resin Layer 46 Projection

Claims (6)

The manufacturing method of a mold which includes the following process (a)-process (f) sequentially, and makes the process liquid in the following process (a)-process (f) the same kind of liquid.
Step (a): A step of immersing the aluminum substrate in the treatment liquid.
Step (b): a first oxide film forming step of forming an oxide film having pores by anodizing an aluminum substrate.
Step (c): An oxide film removing step for removing a part of the oxide film.
Step (d): a second oxide film forming step of forming an oxide film having pores by anodizing an aluminum substrate at a constant voltage.
Step (e): A pore diameter enlargement treatment step in which part of the oxide film is removed to enlarge the pore diameter.
Step (f): A step of alternately repeating the step (d) and the step (e).   The method for producing a mold according to claim 1, wherein the treatment liquid is a mixture of a plurality of acids.   The method for producing a mold according to claim 2, wherein the plurality of acids includes oxalic acid and phosphoric acid.   The method for producing a mold according to claim 1, wherein in the step (c), a concave portion is formed in a lower portion of the remaining oxide film.   An article having a fine concavo-convex structure on the surface thereof, wherein the fine concavo-convex structure comprising a plurality of pores formed on the surface of the mold obtained by the production method according to claim 1 is transferred to the surface of the article. Manufacturing method. An article having a fine concavo-convex structure on the surface, having an inverted structure of the fine concavo-convex structure comprising a plurality of pores formed on the surface of the mold obtained by the production method according to claim 1.