JPWO2007023960A1 - Porous polymer membrane, method for producing the same, and method for producing a stamper used for the production - Google Patents

Abstract

A material is filled in the pores of anodized porous alumina having a porous surface structure, and the anodized porous alumina is dissolved and removed to produce a stamper made of the material and having an inverted structure of the surface structure. The porous polymer film having the surface structure is manufactured by transferring the inverted structure of the stamper to a polymer. A porous polymer membrane having a surface structure in which pores of uniform size are orthogonal to the membrane surface can be produced in a large area without going through complicated steps.

Description

The present invention relates to a porous polymer film and a method for producing the same, and in particular, a method for producing a porous polymer film in which a fine uneven structure such as a porous structure or a hole array structure is transferred to a surface using a stamper. And a method for producing a stamper used for producing a porous polymer film having a concavo-convex structure, for example, a porous structure or a hole array structure, on the surface produced by the method.
This application is based on Japanese Patent Application No. 2005-245702 filed with the Japan Patent Office on August 26, 2005 and Japanese Patent Application No. 2006-059103 filed with the Japan Patent Office on March 6, 2006. Is incorporated herein by reference.

Polymer films having fine concavo-convex structures of submicron to nanometer scale on the surface are expected to be applied to various fields such as water / oil repellency films and antireflection films. Various methods for forming a fine uneven pattern on the surface of a polymer film have been studied so far. Among them, a mold having a fine uneven pattern on the surface is mechanically pressed against a polymer. Therefore, a nanoimprinting method that can form a concavo-convex pattern corresponding to the geometric structure of the mold on the surface of the sample has attracted attention (for example, Non-Patent Document 1). According to this method, a regular structure having a large area can be formed with high throughput, and therefore, it can be expected as a method for manufacturing various nanodevices. However, since electron beam lithography is usually used for producing a mold used for nanoimprinting, it is difficult to produce a fine uneven pattern of 100 nm or less in a large area by these methods. .
S. Y. Chou, P.A. R. Krauss, and J.M. Renstrom, Science, 272, 85 (1996)

  In order to solve the above-described problems in producing a polymer film having a concavo-convex structure, for example, a porous structure or a hole array structure, which is expected to be used in various applications, the present invention has a self-organized pore structure. We have earnestly devised means for easily obtaining a porous polymer film by using a stamper having an inverted structure of the hole array structure prepared using a hole array structure of an arrayed porous material such as anodized porous alumina as a template. It was made as a result of examination.

  An object of the present invention is to produce a porous polymer film having pores of uniform size perpendicular to the film surface, that is, a hole polymer structure on the surface, without a complicated process, in a large area. And a porous polymer membrane produced by the method. Also, a stamper manufacturing method suitable for use in the manufacture thereof, particularly a metal stamper manufacturing method having a high aspect ratio concavo-convex structure (concave concavo-convex pattern), and a high array having a hole array structure in which each pore penetrates. The object is to provide a method for producing a molecular film (so-called through-hole membrane).

  In order to achieve the above object, a method for producing a porous polymer film according to the present invention includes filling a substance into pores of an anodized porous alumina having a porous surface structure and dissolving the anodized porous alumina. Producing a polymer film having the surface structure by forming a stamper made of the material by removing the stamper and having an inverted structure of the surface structure, and transferring the inverted structure of the stamper to a polymer; It is characterized by. That is, a porous polymer film having the surface structure of anodized porous alumina is obtained by using a stamper produced using anodized porous alumina as a mold and transferring the irregularities on the surface of the stamper to the polymer film.

  In order to obtain the stamper used in the present invention, the inside of the pores of the anodized porous alumina and the surface thereof are filled with a substance such as a metal, metal oxide, or semiconductor, and then the mold, that is, the alumina is removed by dissolution. The material of the stamper thus prepared, that is, the substance filled in the pores of the anodized porous alumina and the surface thereof is preferably a metal, and more preferably nickel, gold, and platinum.

  Further, in the method according to the present invention, a stamper produced by using anodized porous alumina having a pore whose pore diameter is continuously changed by repeatedly performing anodization and pore diameter enlargement processing as a template may be used. As described above, if porous alumina having pores with continuously changing pore diameters, which are produced by combining anodization and pore diameter expansion treatment, is used as a mold, a stamper with continuously changing projection diameters can be produced. For this reason, it is possible to produce a porous surface structure in which the pore diameter changes linearly or curvedly in the pore depth direction, that is, a hole array structure on the polymer membrane surface. The hole array structure on the surface of the polymer film formed at this time can be controlled by changing the production conditions of the anodized porous alumina that serves as a template for producing the stamper.

  Moreover, various conditions can be taken as the production conditions of the stamper, particularly as the production conditions of the anodized porous alumina as a mold for producing the stamper. For example, a stamper produced using oxalic acid as an electrolyte and anodized porous alumina produced at an conversion voltage of 30 to 40 V as a mold, or an anodized porous alumina produced at an formation voltage of 10 to 30 V using sulfuric acid as an electrolyte. Alternatively, a stamper manufactured using as a template, or a stamper manufactured using phosphoric acid as an electrolyte and anodized porous alumina prepared at a conversion voltage of 180 to 200 V as a template may be used.

  In addition, in the production of stampers, regular pore arrangement at the bottom of porous alumina pores obtained by anodizing for a long time at a constant voltage under appropriate conditions and dissolving and removing the base metal part and the bottom of the film of the sample. Can be used to obtain a stamper in which protrusions are regularly arranged. By using the stamper thus produced, it is possible to form a hole array structure in which pores of uniform size are regularly arranged on the surface of the polymer film.

  Furthermore, even if anodization is performed for a long time at a constant voltage, the oxide film is once removed, and anodized porous alumina prepared by anodizing again under the same conditions is used as a template, so that a high protrusion arrangement regularity can be obtained. Can be obtained. By using such a stamper, it is possible to obtain a porous polymer film having a hole array structure with regularly arranged pores on the surface.

  Prior to the anodic oxidation, a stamper may be produced using anodized porous alumina formed as a starting point for generating fine pores during anodic oxidation by forming a fine depression on the aluminum surface. According to this method, anodized porous alumina having an arbitrary arrangement can be produced. By using a stamper produced using this as a template, a porous polymer film having a hole array structure having an arbitrary pore arrangement on the surface can be obtained.

  In addition, if a stamper made using anodized porous alumina with a controlled pore size expansion time and a controlled proportion of pore wall portions as a mold is used, a hole array structure with a small proportion of pore wall portions on the surface side can be obtained. It is also possible to obtain a polymer film having the same. For example, the ratio of the pore wall portion on the surface side of the hole array structure formed on the surface of the polymer membrane (that is, the total area of the upper surface of the pore wall relative to the area of the region surrounded by the outer edge of the polymer membrane) It is possible to produce a porous polymer membrane of 30% or less, preferably 20% or less, more preferably 10% or less, and even more preferably 5% or less. The pore cross-sectional shape on the surface side of the hole array structure formed on the surface of the polymer film by enlarging the pore diameter to the limit may be, for example, a triangle, a quadrangle, or a hexagon. Such a porous polymer film has a high porosity on the surface of the sample, so the proportion of flat pore walls is reduced, improving antireflection properties and water / oil repellency. It is effective to make it.

  A porous polymer film having a hole array structure on its surface can be produced by a method of transferring the inversion structure of various stampers using a stamper produced by such a method. For example, a thermal imprint method using a thermoplastic resin as a polymer material for transferring the inverted structure of the stamper, or a photocurable resin (particularly, an ultraviolet curable resin) as the polymer material for transferring the inverted structure of the stamper. In addition to the optical imprint method, a solution in which a polymer is dissolved is cast on a stamper, the solvent is dried, the stamper is peeled off, and the inverted structure of the stamper is transferred to the polymer. A hole array structure similar to the anodized porous alumina used as the starting structure can be formed on the polymer film surface by a technique such as a casting method.

  The present invention also provides a method for producing a metal stamper having a particularly high aspect ratio, which is suitable for the production of the porous polymer film as described above. That is, the stamper manufacturing method according to the present invention is a stamper manufacturing method in which the material is a metal, and when the metal is filled into the pores of the anodized porous alumina serving as the mold by the electrodeposition method, An ion beam sputtering apparatus is used to coat the metal and provide a conductive layer. In particular, this method makes it possible to easily manufacture a metal stamper having a high aspect ratio.

In this stamper manufacturing method, when the conductive layer is applied to the mold surface, the ion beam sputtering is performed under the condition that the degree of vacuum in the sample chamber of the ion beam sputtering apparatus is 3 × 10 ⁻⁴ Pa to 1 × 10 ⁻⁵ Pa. It is preferable to carry out. By optimizing the sputtering conditions in this way, a desirable conductive layer is surely provided.

  By transferring the inverted structure of the stamper manufactured by such a method to a polymer, it becomes possible to easily manufacture a porous polymer film having pores having a shape corresponding to a stamper having a high aspect ratio. .

  The present invention further provides a method for producing a porous polymer membrane, particularly a through-hole membrane. That is, in the method for producing a porous polymer film according to the present invention, the material is filled in the pores of the anodized porous alumina having a porous surface structure, and the anodized porous alumina is dissolved and removed. And a stamper having an inverted structure of the surface structure is prepared, the stamper is placed in a layer of a polymer and a base substrate, and a tip of the convex portion of the reverse structure is placed on the surface of the base substrate via the polymer. A polymer film having the surface structure is produced by applying a load to the stamper until it contacts or reaches the inside to transfer the inverted structure to the polymer, and the polymer film is peeled off from the base substrate (Including the case of dissolving and removing the base substrate), a polymer film having a surface structure (hole array structure) in which each pore penetrates is manufactured. In particular, this method makes it possible to easily manufacture a through-hole membrane.

  In the method for producing a porous polymer film having a hole array structure in which each pore penetrates, a substrate having at least a surface made of a polymer, for example, a polymer substrate or a solution in which a polymer is dissolved is cast as a base substrate. Alternatively, a base substrate obtained by polymerizing monomers on a substrate such as glass to form a polymer film on the surface, or a multilayer base substrate having a polymer film on the outermost surface may be used. Also, a load may be applied to the stamper under heating conditions using at least a base substrate whose surface is made of a thermoplastic resin.

  The present invention also provides a porous polymer membrane produced using the above method.

  According to the porous polymer membrane and the method for producing the same according to the present invention, a hole array structure in which a large number of pores having a uniform size and a fine size and perpendicular to the membrane surface are uniformly arranged in a large area It is possible to easily and efficiently produce a porous polymer film having a surface on the surface without going through complicated steps.

  Further, according to the present invention, a porous polymer film having a hole array structure in which each pore is penetrated can be easily manufactured.

  Furthermore, according to the present invention, it is also possible to provide a high aspect ratio stamper suitable for use in the production of these porous polymer films.

It is a process flowchart which shows an example of the manufacturing process of a stamper. FIG. 5 is a process flow diagram showing an example of a stamper manufacturing process using anodized porous alumina having a pore whose pore diameter is continuously changed as a mold. It is a process flowchart which shows an example of the production process of the porous polymer film by a thermal imprint. It is a process flowchart which shows an example of the production process of the porous polymer film by optical imprint. It is a process flowchart which shows an example of the preparation process of the porous polymer film by the solution cast on a stamper. It is a process flow figure showing an example of a through hole membrane preparation process. It is a figure which shows the observation result by the electron microscope of the surface of the polymethyl methacrylate porous membrane produced by the thermal imprint (pore period 200nm). It is a figure which shows the observation result by the electron microscope of the surface of the acrylic resin porous membrane produced by the photoimprint (pore period 200nm). It is a figure which shows the observation result by the electron microscope of the cross section of the acrylic resin porous membrane produced by the photoimprint (pore period 200nm). It is a figure which shows the observation result by the electron microscope of the surface of the fluororesin porous membrane produced by the casting method (pore period 500nm). It is a figure which shows the observation result by the electron microscope of the metal stamper of the high aspect ratio produced in Example 5. FIG. It is a figure which shows the observation result by the electron microscope of the through-hole membrane produced in Example 6. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum 2 Anodized porous alumina 3 Filling substance layer 4 Stamper 5 Anodized porous alumina having pores whose pore diameter is continuously changed 6 Thermoplastic resin 7 Substrate 8 Porous polymer film 9 Photocurable monomer 10 After polymerization Polymer film 11 Dissolved polymer solution 12 Polymer film after solvent drying 21 Substrate 22 Polymer layer 23 Base substrate 24 Photocurable resin layer 25 Stamper 26 Through-hole membrane 31 Stamper 32 Through-hole membrane

Hereinafter, preferred embodiments of a porous polymer film according to the present invention, a method for producing the same, and a method for producing a stamper used for the production will be described in detail with reference to the drawings.
FIG. 1 shows an example of a stamper manufacturing method using anodized porous alumina used as a mold in the present invention. Anodized porous alumina 2 is produced by anodizing aluminum 1 in an acidic bath, and the material is filled in the pores and on the surface using this as a template (material-filled layer 3). Thereafter, only the aluminum and alumina portions are selectively dissolved and removed. As a substance to be filled, a metal, a metal oxide, a semiconductor, or the like can be used. For example, a metal stamper 4 can be manufactured by forming a conductive thin film on the surface of the anodized porous alumina 2 by sputtering or vapor deposition, and then performing metal electrodeposition using this as an electrode.

  Further, in the present invention, as shown in FIG. 2, anodized porous having pores whose pore diameters are changed linearly or in a curved line by combining anodization and pore enlargement processing by etching. A stamper 4 having a desired projection shape can be obtained by producing alumina 5 and using it as a mold.

  Various imprinting methods can be used for producing a porous polymer film having a hole array structure with pores of uniform pore size arranged on the surface. FIG. 3 shows a method for producing the porous polymer film 8 by the thermal imprint method. A thermoplastic resin 6 is provided on the substrate 7 as a polymer material for transferring the structure of the stamper 4, and the stamper 4 is pressed against the thermoplastic resin 6 under a temperature condition equal to or higher than the glass transition point. By cooling to a temperature and peeling off the stamper 4, it is possible to obtain a porous polymer film 8 to which a fine uneven structure on the stamper surface is transferred.

  Further, as shown in FIG. 4, after an ultraviolet curable (photo curable) monomer 9 is dropped on the substrate 7 as an ultraviolet curable resin as a polymer material for transferring the structure of the stamper 4, the stamper 4 is pressed. An optical imprint method for transferring the structure of the stamper 4 can also be used by irradiating with ultraviolet rays and peeling off the stamper 4 after curing to obtain a polymer film 10 after polymerization.

  In addition to these imprint methods, a polymer solution 11 dissolved in a suitable solvent as shown in FIG. 5 is cast on the stamper 4 and the solvent is dried (polymer film 12 after solvent drying). Alternatively, a method of producing the porous polymer film 8 by peeling off the polymer film can be used.

  According to the present invention, it is possible to produce a porous polymer film having a hole array structure on the film surface in which pores having a uniform size of submicron to nanometer scale are regularly arranged. Further, if the method of the present invention is applied to a thin polymer film, it is possible to obtain a through-hole membrane having pores penetrating.

  FIG. 6 shows an example of a method for producing a through-hole membrane. For example, a photocurable resin layer 24 is provided on a base substrate 23 composed of the substrate 21 and the polymer layer 22, and the tip of the convex portion of the stamper 25 is formed on the surface of the base substrate 23 via the photocurable resin layer 24. The surface structure of the stamper 25 is transferred by applying a load to the stamper 25 until it reaches the inside of the base substrate 23 slightly beyond the position. After the stamper 25 is peeled off, it is peeled off from the base substrate 23 or an equivalent operation. For example, the through-hole membrane 26 can be obtained by dissolving and removing the base substrate 23 (in this case, dissolving and removing the polymer layer 22).

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by this Example.

Example 1 [Preparation of a porous polymer film using a stamper prepared using anodized porous alumina as a template]
An aluminum plate having a purity of 99.99% was subjected to an electropolishing treatment in a mixed solution of perchloric acid and ethanol (volume ratio 1: 4). The mirror-finished aluminum plate was anodized in an aqueous oxalic acid solution adjusted to a concentration of 0.3 M at a bath temperature of 17 ° C. under a direct current of 40 V for 15 hours, and the oxide layer was once dissolved. After removing and anodizing again for 90 seconds under the same conditions, anodized porous alumina having a hole depth of 150 nm was formed. Thereafter, the sample was immersed in a 5% by weight phosphoric acid aqueous solution for 30 minutes, subjected to a pore size expansion treatment, and the pore size was adjusted to 70 nm. This surface was coated with 50 nm of Pt—Pd using a sputtering apparatus, and Ni electrodeposition was performed. Thereafter, the template was dissolved and removed with an aqueous sodium hydroxide solution to obtain a stamper having a regular protrusion arrangement on the surface. A hole array structure in which pores are regularly arranged by imprinting the polymethyl methacrylate resin surface formed on the Si substrate under a heating condition of 180 ° C. using the obtained Ni stamper. As a result, a polymer film having a surface on the surface was obtained.

Example 2 [Production of Polymethyl Methacrylate (PMMA) Porous Membrane by Thermal Imprinting Method Using Stamper Controlling Projection Shape]
A SiC mold having a structure in which protrusions are regularly arranged with a period of 200 nm was pressed against the surface of an aluminum plate having a purity of 99.99% to form a fine uneven pattern on the surface. The textured aluminum plate was anodized in an aqueous oxalic acid solution adjusted to a concentration of 0.05 M at a bath temperature of 17 ° C. under a direct current of 80 V for 2 seconds. Then, it was immersed in a 10% by weight phosphoric acid aqueous solution for 25 minutes, and subjected to a pore size expansion treatment. By repeating this operation five times, porous alumina having tapered pores having a pore period of 200 nm, a pore opening of 200 nm, a bottom of 50 nm, and a pore depth of 300 nm was obtained. This surface was coated with 50 nm of Pt—Pd using a sputtering apparatus, and Ni electrodeposition was performed. Then, the stamper which has a regular protrusion arrangement | sequence on the surface was obtained by melt | dissolving and removing a casting_mold | template. A hole array structure in which pores are regularly arranged by imprinting a polymethyl methacrylate resin surface formed on a Si substrate under a heating condition of 180 ° C. using the obtained Ni stamper. As a result, a polymer film having a surface on the surface was obtained. FIG. 7 shows an electron micrograph (a diagram observed with an electron microscope) of the surface of a polymethyl methacrylate porous membrane (porous polymer membrane 8) produced by thermal imprinting.

Example 3 [Production of Acrylic Porous Membrane by Photoimprinting Method Using Stamper Controlling Projection Shape]
The Ni stamper produced by the same method as in Example 2 was irradiated with ultraviolet rays while being pressed against the acrylic monomer dropped on the glass substrate. After the monomer was cured, the stamper was peeled off to produce a porous acrylic resin film on the substrate. FIG. 8 shows an electron micrograph (a diagram observed with an electron microscope) of the surface of the prepared acrylic resin porous membrane (porous polymer membrane 8), and FIG. 9 shows a cross-sectional electron micrograph (a diagram observed with an electron microscope). Shown in

Example 4 [Production of Fluororesin Porous Membrane by Casting Method Using Stamper Controlling Projection Shape]
A SiC mold having a structure in which protrusions were regularly arranged with a period of 500 nm was pressed against the surface of an aluminum plate having a purity of 99.99% to form a fine uneven pattern on the surface. The textured aluminum plate was anodized for 10 seconds in a phosphoric acid aqueous solution adjusted to a concentration of 0.1 M at a bath temperature of 0 ° C. and a direct current of 200 V. Then, it was immersed in a 10% by weight phosphoric acid aqueous solution for 25 minutes, and subjected to a pore size expansion treatment. By repeating this operation five times, porous alumina having tapered pores having a pore period of 500 nm, a pore opening portion of 400 nm, a bottom portion of 150 nm, and a pore depth of 800 nm was obtained. This surface was coated with 50 nm of Pt—Pd using a sputtering apparatus, and Ni electrodeposition was performed. Then, the stamper which has a regular protrusion arrangement | sequence on the surface was obtained by melt | dissolving and removing a casting_mold | template. A fluorine solution in which a fluororesin was dissolved was dropped on the produced stamper and dried, and then the stamper was peeled off to produce a porous fluororesin film. FIG. 10 shows an electron micrograph (a diagram observed with an electron microscope) of the surface of the produced fluororesin porous membrane (porous polymer membrane 8).

Example 5 [Production of Metal Stamper with High Aspect Ratio]
An aluminum plate having a purity of 99.99% was subjected to electropolishing treatment in a mixed solution of perchloric acid and ethanol (volume ratio 1: 4). A SiC mold having a structure in which protrusions were regularly arranged at a cycle of 500 nm was pressed against a mirror-finished aluminum plate to form a fine uneven pattern on the surface. Anodization was carried out for 14 minutes in a phosphoric acid aqueous solution adjusted to a concentration of 0.1 M at a bath temperature of 0 ° C. and a direct current of 200 V. Thereafter, the sample was immersed in a 10% by weight phosphoric acid aqueous solution for 30 minutes, subjected to pore diameter enlargement treatment, and the pore size was adjusted to 300 nm. This surface was coated with 50 nm of Pt using an ion beam sputtering apparatus, and then Ni electrodeposition was performed. Then, the stamper which has a regular protrusion arrangement | sequence on the surface was obtained by melt | dissolving and removing a casting_mold | template. The manufactured Ni stamper 31 is shown in FIG.

Example 6 [Production of Through-Hole Membrane]
A photocurable resin was dropped onto a Ni stamper produced in the same manner as in Example 5, and defoamed under reduced pressure. A stamper was pressed onto the glass substrate on which PMMA was cast, and ultraviolet irradiation was performed while applying a load. After the resin was completely cured by light irradiation, the Ni stamper was peeled off. The sample was immersed in acetone, and only the PMMA layer was selectively dissolved and removed to obtain a polymer through-hole membrane. The produced through-hole membrane 32 is shown in FIGS. 12A and 12B.

Claims (24)

A material is filled in the pores of anodized porous alumina having a porous surface structure, and the anodized porous alumina is dissolved and removed to produce a stamper made of the material and having an inverted structure of the surface structure. ,
A method for producing a porous polymer film, wherein the polymer film having the surface structure is produced by transferring the inverted structure of the stamper to a polymer.   The method for producing a porous polymer film according to claim 1, wherein the substance is a metal.   The method for producing a porous polymer film according to claim 2, wherein the metal is any one of nickel, gold, and platinum.   The method for producing a porous polymer film according to claim 1, wherein the anodized porous alumina has pores whose pore diameter is continuously changed by repeatedly performing anodization and pore diameter expansion treatment.   The method for producing a porous polymer film according to claim 1, wherein the anodized porous alumina is produced using oxalic acid as an electrolytic solution at a conversion voltage of 30 V to 40 V.   The method for producing a porous polymer film according to claim 1, wherein the anodized porous alumina is produced using sulfuric acid as an electrolytic solution and at a conversion voltage of 10V to 30V.   The method for producing a porous polymer film according to claim 1, wherein the anodized porous alumina is produced using phosphoric acid as an electrolytic solution at a conversion voltage of 180 V to 200 V.   The porous polymer film according to claim 1, wherein the anodized porous alumina is prepared by anodizing at a constant voltage, once dissolving and removing the oxide film, and again anodizing under the same conditions. Production method.   The porosity according to claim 1, wherein the anodized porous alumina is produced by forming a fine depression on the surface of aluminum before anodization and anodizing the depression as a starting point of pore generation. A method for producing a polymer membrane.   The method for producing a porous polymer membrane according to claim 1, wherein the ratio of the pore wall portion on the surface side of the surface structure of the polymer membrane is 30% or less.   The method for producing a porous polymer film according to claim 10, wherein the ratio of the pore wall portion on the surface side of the surface structure of the polymer film is 20% or less.   The method for producing a porous polymer film according to claim 11, wherein the ratio of the pore wall portion on the surface side of the surface structure of the polymer film is 10% or less.   The method for producing a porous polymer membrane according to claim 12, wherein the ratio of the pore wall portion on the surface side of the surface structure of the polymer membrane is 5% or less.   The method for producing a porous polymer film according to claim 1, wherein the cross-sectional shape of the pores on the surface side of the surface structure of the polymer film is a triangle, a quadrangle, or a hexagon.   The method for producing a porous polymer film according to claim 1, wherein the polymer is a thermoplastic resin.   The method for producing a porous polymer film according to claim 1, wherein the polymer is a photocurable resin.   2. The porous polymer according to claim 1, wherein a solution in which the polymer is dissolved is cast on the stamper, the solvent is dried, and the stamper is peeled off to transfer the surface structure of the stamper to the polymer. A method for producing a membrane.   A stamper manufacturing method in which a metal is coated on the surface of an anodized porous alumina using an ion beam sputtering device when a metal is filled in the pores of the anodized porous alumina by an electrodeposition method. 19. The method for manufacturing a stamper according to claim 18, wherein the ion beam sputtering is performed under a condition of a vacuum degree of 3 × 10 ⁻⁴ Pa to 1 × 10 ⁻⁵ Pa when the conductive layer is applied to the surface of the anodized porous alumina. .   A method for producing a porous polymer film, wherein the surface structure of a stamper produced by the method for producing a stamper according to claim 18 is transferred to a polymer. Filling the pores of anodized porous alumina having a porous surface structure with a substance, and dissolving and removing the anodized porous alumina to produce a stamper made of the substance and having an inverted structure of the surface structure;
The stamper is installed in a layer of a polymer and a base substrate, and a load is applied to the stamper until the tip of the convex portion of the inverted structure contacts or reaches the surface of the base substrate through the polymer. A polymer film having the surface structure is produced by transferring an inverted structure to the polymer,
A method for producing a porous polymer film, comprising producing a polymer film having a surface structure in which each pore penetrates by peeling the polymer film from the base substrate.   The method for producing a porous polymer film according to claim 21, wherein at least a surface of the base substrate is a polymer.   The method for producing a porous polymer film according to claim 22, wherein the polymer is a thermoplastic resin, and a load is applied to the stamper under heating conditions.   A porous polymer membrane produced by using the method according to any one of claims 1 to 17 and 20 to 23.

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