KR102130665B1 - Method of manufacturing mold for superhydrophobic material, superhydrophobic material and method of manufacturing the same - Google Patents

Abstract

The present invention provides a super water-repellent mold manufacturing method, a super-water-repellent material using the super-water-repellent mold, and a method of manufacturing the same, comprising: bonding a photoresist to a metal surface for a mold; Forming a photosensitive micro pattern by photosensitive the photoresist through lithography; Forming a first anodized layer through anodization on the photosensitive micro pattern; Etching the first anodized layer to form an anodized micropattern that is deeper than the photosensitive micropattern and includes nanoseeds; Forming a second anodized layer comprising an anodized nano pattern through anodization on the anodized micro pattern including nano seeds; It is a technical summary to include the step of adjusting the diameter and the depression depth of the nanopores by etching the anodized nanopattern made of nanopores. This simplifies the process by not performing an etching step among the steps of etching and anodizing to obtain an anodized micro pattern, thereby reducing manufacturing cost and manufacturing time, and also using anodization between photoresist and metal. The bonding strength is maintained, and an effect capable of increasing the depth of the micro pattern can be obtained by controlling the anodization time.

Description

Method for manufacturing super water-repellent mold, material for super water-repellent using super-water-repellent mold, and method for manufacturing same {Method of manufacturing mold for superhydrophobic material, superhydrophobic material and method of manufacturing the same}

The present invention relates to a method for manufacturing a super water-repellent mold, a material for super-water-repellent using a super-water-repellent mold, and a method for manufacturing the same, and more specifically, a process without etching during the etching and anodizing to obtain an anodized micro pattern The present invention relates to a method for manufacturing a super-water-repellent mold, a material for a super-water-repellent using a super-water-repellent mold, and a method for manufacturing the same.

In general, the surface of a solid such as a metal, ceramic, polymer, etc. has a surface energy inherent to the material, and when a liquid such as water or oil is deposited on the surface, the surface energy is determined by a contact angle between the solid surface and the liquid. To reflect. When the contact angle is 90° or less, the liquid spreads on the solid surface and shows hydrophilicity and excellent wettability, which makes the surface wet with the liquid. When the contact angle is 90° or more, the spherical liquid droplet does not wet the solid surface and forms a spherical shape. It exhibits water repellency, which is a characteristic that is maintained. In addition, when the contact angle is 150° or more, the spherical liquid droplet exhibits repelling properties on the solid surface, and does not remain stationary on the surface of the solid. At this time, the liquid drop rolling on the surface of the solid rolls and falls together with contaminants such as dust attached to the solid surface, so that the self-cleaning characteristic of spontaneously washing the surface additionally appears. A representative example of such super water repellency is the Lotus effect, which rolls on the surface while falling on the surface of the lotus leaf without condensation.

In addition to the lotus effect, non-freezing, non-wetting, non-condensing, non-corrosive, and antibacterial properties are given to the surface that exhibits super water repellency, so it is a fingerprint-free display panel, self-cleaning building window, self-cleaning vinyl house, self-cleaning solar cell protective film, corrosion And various corridor surfaces to prevent freezing, inner and outer walls of transport pipes and pipes to prevent corrosion and freezing, non-frozen aircraft body and wings, self-cleaning and non-freezing automobile bodies, toes, and ship bodies to prevent various seaweed habitat, ice or snow It is a versatile material technology that has a wide range of applications such as skating rinks and ski fields.

It is known that the lotus effect having both super water repellency and self-cleaning effect appears when the surface of the water-repellent material having little surface energy has a micro-structured surface with a micro-structured and nano-scaled structure. In general, when a solid surface has an uneven structure of a microscopic size, the contact angle changes, which is caused by an increase in the contact angle on both a hydrophilic surface and a water-repellent surface. Therefore, as the water-repellent surface becomes microscopically rough, the water-repellent property increases because air is trapped in the micro-structure to reduce the contact area between the liquid and solid surfaces. That is, when water droplets are placed on the lotus leaf, the air trapped in the microstructure prevents the entire surface from getting wet, so that only a very small area, such as the end of the microstructure surface, comes into contact with the water droplets. This phenomenon expands the interface between water and air, but minimizes the interface between the solid surface and water droplets, so it does not supply any energy for expanding the surface of water droplets through contact, so that water does not spread and has a spherical shape.

Therefore, the contact angle between the water and the solid surface is entirely dependent on the surface tension of the water. The correlation between the contact angle and the geometry of the solid surface is a mixture of Cassie-Baxter and Wenzel models:

cosθrc = rf cosθ + f -1

Can be represented as Where r is the ratio of the contact area between the actual solid surface-liquid droplets minus the vertically projected solid surface-liquid droplet contact area minus the liquid droplet-air contact area, θrc is the apparent contact angle on the rough surface, and θ is The contact angle on a flat solid surface, f is the fraction of the solid surface fraction, ie the total contact area of the liquid droplets, to the total contact area of the area actually in contact with the solid surface minus the contact area with air.

Such a super water-repellent surface can be produced by forming a microscopic-sized surface structure on a water-repellent surface, coating a water-repellent film on a surface having a micro-sized roughness, or forming a rough surface structure while simultaneously lowering the surface energy of a material. , To date, a myriad of methods have been developed for the preparation of this super water-repellent surface. Among these methods, a mold having a nanostructure suitable for super water repellency is manufactured by using nanostructures in which nano-pores having a size of several to several hundreds nm are formed when anodizing an aluminum metal surface, and nano-sized water-repellent materials are used therewith. Methods for manufacturing super water-repellent materials by manufacturing surface structures have been developed.

The prior art US20090011222A1 patent reports that an anodized aluminum metal surface was obtained to obtain a nanostructured surface in which nanopores of 60 to 70 nm were arranged, followed by PFOS treatment on the top to obtain a contact angle of 175.6° and a contact angle of 5°. Doing. However, it is stated that after 1000 hours of QUV testing, it decreased to a contact angle of 120 to 130°.

The US7,393,391B2 patent obtains a nanostructured surface with 50 to 150nm nanopores arranged by anodizing an aluminum metal surface by a two-step anodization method, and then separates it from the substrate, and one side is 50 to 300nm thick plasma polymerized fluorine It is described that a water-repellent surface having a contact angle of 140° or more was formed by forming a carbon film, and a hydrophilic surface having a contact angle of 10° or less was obtained as the other surface was formed.

US20090260702A1, US20100028615A1, and US20100126873A1 patents use a particle sprayer on a plate or cylindrical aluminum surface for the production of super water-repellent surfaces to make sand particles of 50 to 150 microns in size to make micron-sized irregularities on the surface, and then anodize this surface By oxidizing, nano-sized pores are present to create a surface in which microstructures and nanostructures are mixed. It has been reported that by using this as a mold, surface radiation was applied to water-repellent materials such as polytetrafluoroethylene (PTFE) to impart superhydrophobicity with a contact angle of 165°.

US20090194914A1 and US20100243458A1 patents are patents related to stamps or molds for manufacturing anti-reflection products for which superhydrophobic surfaces are not intended, and their manufacturing methods, anodizing a cylindrical aluminum metal surface with two-step anodization Then, a chemical etching method and an anodization method using a lower applied voltage were mixed to prepare a mold having an insect-like structure.

However, for excellent super water repellency, it is desirable to have a microscopic surface in which microstructures and nanostructures are mixed, and the above-described prior arts make nanostructures using anodization without mentioning the technology for the production of microstructures, and then upper It is a technology for producing a surface having excellent water repellency, not super water repellency, by coating a water repellent polymer material on it. In addition, as a mold manufacturing technology for mass production of super water-repellent surface materials, the technology is not excellent in water-repellent performance by forming the surface with only the nano-structured surface without the technology of making a micro-structure, or before forming the nano-structure through anodization. It is a technology to make fine structures by shooting particles such as sand with a particle sprayer for the production of fine structures. This technology not only has a non-uniform microstructure, but also has a uniformity in the nano-pore distribution, which has the property of growing perpendicularly to the surface and preferentially growing on the recessed surface, and the pores grow at various angles, thereby forming a replica of the molded body. There is a disadvantage that demoulding is not easy when demoulding.

In addition, superhydrophobicity is reported to appear on surfaces formed only of micro-sized microstructures in addition to surfaces where microstructures and nanostructures are mixed. In this case, when nanostructures are mixed in microstructures, water contact angle and water contact angle hysteresis are remarkable. It is known to increase significantly. In general, in order to manufacture a microstructure, it is manufactured using a lithography technique, and the cheapest method of the lithography technique is a UV lithography technique using UV light. UV lithography technology Although it is well developed for metals such as nickel (Ni) or chromium (Cr), development for aluminum (Al) is insignificant.

Patterning of aluminum surfaces by UV lithography is intended to produce sub-micron-sized micropatterns and is known to be unsuitable for manufacturing micro-patterns of several to several tens of microns in size. Such a method is 1) after lithography 2) forming a microstructure by etching, 3) after anodizing for a long time to relatively align the pores or holes of the microstructure, 4) etching it again to anodize After removing the formed alumina layer, 5) obtaining a surface with a convex nano-sized seed arranged thereafter, and 6) performing an anodization and etching for a certain period of time to form a nanoporous or hole-aligned imprinting mold. Was prepared. However, in the case of manufacturing the mold in this way, the process of manufacturing the mold is complicated due to the large number of steps, and the mold manufacturing process is inefficient due to the time and material consumption. In addition, when forming a microstructure through etching after lithography, the bonding force between the photoresist and aluminum is weakened by the etching solution used for etching, and it penetrates into the gap between the surfaces unevenly to obtain an uneven microstructure, as well as a long time Since etching is impossible, there is a problem that the depth of the microstructure is limited.

United States Patent Office Publication Patent Publication US 20090011222 A1 (published on January 8, 2009) US Patent Office Publication Patent Publication US 7,393,391 B2 (Announcement date of July 1, 2008) United States Patent Office Publication Patent Publication US 20090260702 A1 (published on October 22, 2009) United States Patent Office Publication Patent Publication US 20100028615 A1 (published February 4, 2010) United States Patent Office Publication Patent Publication US 20100126873 A1 (published on May 27, 2010)

Accordingly, an object of the present invention is to simplify the process by not performing an etching step of etching and anodizing in order to obtain an anodized micro-pattern, thereby making a super water-repellent mold manufacturing method and super water-repellent capable of reducing manufacturing cost and manufacturing time. It is to provide a material for super water repellent using a mold and a method for manufacturing the same.

In addition, by using anodization, the bonding force between the photoresist and the metal is maintained, and the method for manufacturing a super water-repellent mold that can increase the depth of a micro pattern by adjusting the anodization time, and a material for the super-water-repellent material using the super-water-repellent mold and a method for manufacturing the same Is to provide.

The above object comprises the steps of bonding a photoresist to a metal surface for a mold; Forming a photosensitive micro pattern by photosensitive the photoresist through lithography; Forming a first anodized layer through anodization on the photosensitive micro pattern; It is achieved by a method for manufacturing a super water-repellent mold comprising removing the first anodized layer by etching to form an anodized micro pattern that is deeper than the photosensitive micro pattern and includes nano seeds.

Here, after the step of forming the anodized micro-pattern, forming a second anodized layer containing an anodized nano-pattern through anodization in the anodized micro-pattern containing nano-seed; Adjusting the diameter of the nanopores by etching the anodized nanopattern made of nanopores; And repeating anodization and etching several times to control the shape of the nanopores, and forming the anodization layer after the second anodization layer is performed within a shorter time than forming the first anodization layer. It is preferred.

In addition, after the step of forming the anodized nano pattern, a material selected from the group consisting of Ni, W, SiC, SiN, AlN and mixtures thereof is coated on the metal surface for the mold to improve the strength of the metal for the mold. It is preferable to further include a step, or to further include a step of coating a release film on the mold metal to improve desorption of the polymer material for super water repellency from the mold metal.

The anodized micro-pattern is formed in a hemispherical shape, and the anodized nano-pattern is formed in various shapes such as a convex cylindrical shape or a conical shape with a pointed end inside the hemispherical shape of the anodized micro-pattern. It is preferable that the ratio of the diameter and the depth is 1: 0.1 to 1: 10 depending on the purpose.

The above object comprises the steps of bonding a photoresist to a metal surface for a mold; Forming a photosensitive micro pattern by etching the photoresist through lithography; Forming a first anodized layer through anodization on the photosensitive micro pattern; Removing the first anodized layer to form an anodized micropattern that is deeper than the photosensitive micropattern and includes a nanoseed; It is also achieved by a method for producing a super water-repellent material using a super-water-repellent mold, characterized in that it comprises the step of coating and demolding a polymer resin in a mold on which the anodized micro pattern is formed.

According to the above-described configuration of the present invention, the process is simplified by not performing an etching step among the steps of etching and anodizing to obtain an anodized micro pattern, thereby reducing manufacturing cost and manufacturing time, and also using anodizing. By maintaining the bonding force between the photoresist and the metal, it is possible to obtain an effect of increasing the depth of the micro pattern by controlling the anodization time.

1 is a flow chart of a method for manufacturing a super water-repellent mold according to an embodiment of the present invention,
Figure 2 is a flow chart of a method for manufacturing a super water-repellent material using a super water-repellent mold,
3 is a conceptual diagram of a method for manufacturing a super water-repellent material,
4 is an optical photograph of a negative photomask for lithography,
5 is an FE-SEM photograph of a photosensitive micro pattern manufactured using the photomask of FIG. 4,
6 is an FE-SEM photograph of the surface of the first anodized layer prepared by anodizing the surface of FIG. 5,
FIG. 7 is an FE-SEM photograph of an anodized micro pattern surface in which nano seeds are engraved on the surface after removing the first anodized layer of FIG. 6;
8 is an FE-SEM photograph of the surface of the second anodized layer showing the alignment of the hemisphere-shaped anodized micro-patterned unit cells engraved with a conical anodized nano-patterned unit cell formed by repeating anodization and etching processes,
9 is an enlarged FE-SEM photograph of the anodized nano pattern engraved on the anodized micro pattern of FIG. 8,
10 is a photograph of the surface FE-SEM photo and water contact angle of the PMMA polymer super water-repellent material prepared using a mold,
FIG. 11 is a photograph of the surface FE-SEM photograph and the water contact angle of a PC polymer superhydrophobic material manufactured using a mold.

Hereinafter, a method for manufacturing a super-water-repellent mold according to an embodiment of the present invention, a material for super-water-repellent using the super-water-repellent mold, and a method for manufacturing the same will be described with reference to the drawings.

First, as a method of manufacturing a super water-repellent mold, a photoresist is bonded to a metal surface for a mold as shown in FIG. 1 (S1).

Here, the metal for the mold is from the group consisting of aluminum (Al), tungsten (W), titanium (Ti), tantalum (Ta), hafnium (Hf), niobium (Nb), zirconium (Zr), and mixtures thereof. It is preferable to select, among which aluminum is the most preferable because of its low cost and easy anodization. In some cases, the metal for the mold is copper (Cu), manganese (Mn), silicon (Si), chromium (Cr), lithium (Li), vanadium (V), molybdenum (Mo), gallium (Ga), At least one of germanium (Ge), iron (Fe), cobalt (Co), nickel (Ni), carbon (C), and oxygen (O) elements may be further mixed. When such an element is added, the strength of the metal for the mold can be controlled. In addition, the metal for the mold is preferably made of a flat plate or a roll (roll) type.

A photoresist is bonded to the mold metal as shown in FIG. 3, and any photoresist that is generally used may be used and is not particularly limited.

In some cases, the metal surface for the mold may be further cleaned and polished so that no contaminants adhere between the metal for the mold and the photoresist. Here, the metal surface for the mold is cleaned using alcohol, acetone or aqua regia, and the polishing step may be performed through mechanical polishing or electrolytic polishing. It is preferable that the metal surface for the mold has a roughness of 0.1 nm to 10 μm through the polishing step.

The photoresist is photosensitive to form a photosensitive micro pattern (S2).

A positive photomask or negative photomask is placed on top of the photoresist, and the photoresist is photosensitive to form a desired photosensitive micropattern through lithography. Here, lithography is possible through a UV light or an electron beam method, but it is most preferable to use UV light lithography, which is high in cost-performance.

When the photoresist is photosensitive through lithography, the photoresist is removed at the photosensitive position and the metal for the mold is exposed. This area is called a photosensitive micro pattern.

A first anodization layer is formed on the photosensitive micro pattern (S3).

A first anodization layer is formed through anodization on a photosensitive micro pattern formed in a region excluding the photoresist. Conventionally, a micro pattern was deeply formed through etching rather than anodization in a photosensitive micro pattern region excluding photoresist. However, when the micro-pattern is controlled through etching as described above, the solution used in the etching process penetrates between the photoresist and the metal for the mold to weaken their bonding, and through this, the photoresist is separated to etch the desired pattern. There was a problem not to lose. This occurs because photoresists are vulnerable to solutions used in etching processes.

In order to solve this, in the present invention, an anodization micro pattern is formed through anodization except for an etching process. When the etching process is excluded, the occurrence of the problem of separation of the metal bond for the photoresist and the mold is delayed because the etching solution is not used, and the process for a long time is possible because an anodization solution that has less influence on the photoresist is used. Through this, a deep anodized micro pattern can be obtained.

The depth of the anodization micro pattern is determined by the time during which the anodization proceeds. That is, when the anodization is performed for a long time, the anodization layer is thickened to deepen the depth of the anodization micro pattern, and when the anodization is short, an anodization micro pattern having a relatively shallow depth can be obtained.

Anodic oxidation is an electrolyte with a concentration of 0.01 to 5 M of Phosphoric acid, Oxalic acid, Sulfuric acid, Selenic acid, Malonic acid, Acetic acid, and Tartrate ( A solution selected from the group consisting of tartaric acid, citric acid, etridonic acid and mixtures thereof is used. The anodizing condition is preferably performed by applying a voltage of 1 to 500V for 1 second to 1 week while maintaining a temperature of -50 to 300°C.

The time for applying the voltage can be changed according to the desired depth of the anodized micro pattern, and basically, anodizing for 10 hours or more is necessary to form a deep anodized micro pattern, and later to obtain a well-ordered nanoseed. desirable.

The first anodization layer is removed by etching to form an anodization micro pattern (S4).

When the first anodized layer formed in the photosensitive micro pattern region is completely removed using an etching solution, an anodized micro pattern is formed on the mold metal. The anodization micro pattern has a depth of depression determined according to the depth of the first anodization layer, and is deeper than that of forming a pattern through conventional etching. For the etching of the first anodization layer, a phosphoric acid etching solution different from that of the prior art is used, and the phosphoric acid etching solution is removed to the oxide barrier layer at the bottom of the first anodization layer. In addition, nano seeds, which are traces of the oxide barrier layer formed through anodization, are formed in the anodization micro pattern. Here, the anodized micro pattern is formed in a shape in which hemispherical unit cells are arranged in a hexagonal shape, and the nanoseed is formed in a shape in which convex hemispheres are arranged in a hexagonal shape in a round bottom region of the anodized micro pattern.

The anodized micro pattern formed through the removal of the first anodized layer is deeply recessed to a length of 2 to 20 times that of the photosensitive micro pattern formed in step S2. That is, the anodized micro pattern is preferably recessed at a depth of 0.1 to 50 μm, an area of 0.1 to 100 μm, and an interval of 0.1 to 50 μm. When the depth of the unit cell in the anodized micro pattern is less than 0.1 µm, the depression depth is shallow, so it is difficult to exhibit super water repellency, and it is difficult to form the anodized micro pattern to exceed 50 µm depth. In addition, when the area of the anodized micro pattern exceeds 100 μm, it is difficult to exhibit a super water-repellent phenomenon because the area is too wide. When the anodized micro pattern interval is less than 0.1 µm, the gap between the patterns is too close, and when it exceeds 50 µm, the gap between the patterns is too far, so it is not suitable to use the anodized micro pattern. Here, it is preferable to further include the step of removing the photoresist remaining in the mold metal after the first anodization layer is removed.

When the first anodization layer is removed in this way, a surface in which anodization micro-patterns and nano-seeds are mixed is formed, and it is possible to have super water repellency by itself. However, by further forming a nano pattern on the nanoseed, superior water repellency can be realized, and the following process is additionally performed for this.

A second anodization layer is formed on the anodization micro pattern (S5).

The second anodized layer is formed by anodizing the anodized micro pattern formed through the removal of the first anodized layer in the same manner as in step S3. When anodization is performed on the anodized micro pattern, the nanopores, which are unit cells of the anodized nanopattern, grow vertically from the deepest side of the nanoseed formed in S4 to the bottom. At this time, the length of the nanopores is determined by adjusting the anodization time in consideration of the ratio of the final diameter and the depth of the nanopores due to the enlargement of the nanopores through an etching process. Through the S5 step, anodization is performed in accordance with the shape and arrangement of the nanoseed, and through this, a second anodized layer having a shape in which nanopores grown in the center of the nanoseed are well aligned in a hexagon is formed. At this time, it is preferable that the anodization condition of the S5 step is the same as the anodization condition of the S3 step to produce a better aligned nano pattern.

Here, in the second anodization layer, the diameter and depth ratio of the nanopores are different depending on the purpose of the mold to be finally formed. For superhydrophobicity, it is preferable that it is mainly 10 or less, and for other purposes, the anodized nano which nanopores of 100 or less are aligned. It is necessary to form the second anodized layer very thickly to form a pattern. That is, the time for forming the second anodization layer is preferably about 1 second to 1 week. When the anodization time exceeds 1 week, the diameter and depth ratio of the nanopores are too large, and when using this mold to prepare a superhydrophobic material, demoulding is difficult. In addition, even if it is demolded, the nano-pillar formed through the nano-pores does not stand and lie down to achieve the original purpose of forming the nano-pores. Therefore, in order to form anodized nanopatterns in which pores of a desired diameter and depth ratio are aligned in the anodized micropattern, the anodization time must be adjusted.

The pore diameter of the anodized nano pattern is adjusted by etching the second anodized layer (S6).

Unlike the S4 step of forming the anodized micropattern and the nanoseed by etching and removing the entire anodized first anodized layer in the S3 step, the etching of the S6 step enlarges the diameter of the nanopattern present in the second anodized layer. In order to etch, an anodized nano pattern having an enlarged diameter of nano pores as a unit cell is formed through S6.

Here, the anodized nano pattern is preferably formed in a convex downward cylindrical shape or a conical shape with a pointed end, but such a shape is not limited and depends on the purpose of use of the mold. That is, a conical shape is preferred for non-reflection, and a cylindrical shape is preferred for super water repellency.

The etching of the S6 step has a different purpose from the etching of the S4 step, but it is the same etching in terms of etching to remove the anodization layer, and is preferably removed through a phosphoric acid solution.

The anodization and etching are repeated to adjust the shape and size of the anodization nano pattern (S7).

Anodization and etching are repeated to form the desired pore shape and size of the anodized nanopattern formed in step S6, and the anodized nanopattern is formed while controlling the time respectively. At this time, the anodization and etching time are adjusted in consideration of the diameter and depth ratio of the nano-pores after step S6. Here, the diameter:depth ratio of the nanopores is preferably 1:0.1 to 1:10. When the ratio exceeds 1: 10, the nano-pillar formed as a nano pattern in the finally produced super water-repellent material does not stand and tends to lie down. When the ratio is less than 1: 0.1, the length of the nano-pillar is short, resulting in super water-repellent Sometimes it is difficult to show the phenomenon. In addition, in the anodized nano pattern, the distance of the nano-space, which is a unit cell, that is, the distance between the nano-pillars in the super-water-repellent material is determined by the type of the electrolyte and the applied voltage, and the final result of the super-water-repellent material produced using the super-water-repellent mold It depends on the application. For example, in the case of a mold for manufacturing a replica film for non-visible use of visible light, the period is preferably around 140 nm.

In some cases, after the step of forming the anodized nano pattern, an additional coating process may be performed on the surface of the anodized mold to improve the strength of the anodized mold. At this time, the coating is a material selected from the group consisting of nickel (Ni), tungsten (W), silicon carbide (SiC), aluminum nitride (AlN), and mixtures thereof. In addition, the strength can be improved and the anodized micro and nano patterns are not damaged. Any coating material that is not used may be used.

In some cases, in order to manufacture a mold having a higher strength than the anodization mold using an anodization mold, anodization is performed after depositing or coating a polymer, metal, alloy or ceramic material on the pores and surfaces of the anodization mold. The mold is removed to produce an embossed mold of polymer, metal or ceramic material. After that, it is preferable to manufacture and utilize an intaglio mold of high strength metal, alloy or ceramic material by depositing or coating the high strength metal, alloy or ceramic material again on the embossed mold and removing the embossed mold. For the primary coating at this time, polymer materials such as PDMS, PA or PTFE, metals of any kind such as Al, Mn, Ti, W, Cu, Ni, Cr or alloys thereof, or SiC, diamond, DLC, etc. Various ceramic materials are available, and for secondary coating, it is preferable to coat high-strength metals such as Ni, Cr, W, or alloys thereof, or high-strength ceramic materials such as SiC, diamond, or DLC.

A release film is coated on the surface of the intaglio mold of anodized metal, high-strength metal, high-strength alloy or ceramic material (S8).

After the step of forming the anodized nano-pattern or after preparing an intaglio mold of a high-strength metal, alloy or ceramic material, this mold is used to improve the desorption property of the superhydrophobic polymer material from the anodized metal, high-strength metal high-strength alloy or ceramic mold Further comprising the step of coating the release film on the surface of the. The material of the release film may be a nanocomposite in which nanoparticles such as silicon oxide (SiO ₂ ) or titanium oxide (TiO ₂ ) are mixed in various water repellent materials or water repellent materials including alkyl silicon.

As described above, the super water-repellent material may be manufactured using the super water-repellent mold obtained through the steps S1 to S8. This is done in the order shown in FIG. 2, where steps S1 to S8 are described in FIG. 1 and above, and a description thereof will be omitted.

The super water-repellent material is coated with a polymer resin on the super water-repellent mold obtained through steps S1 to S6 (S9).

Here, the method of coating the polymer resin is performed through a polymer solution method, a thermal imprinting method, a UV-imprinting method or a chemical imprinting method, but various other coating methods are applicable.

In addition, the polymer resin is polyamide (PA); polystyrene (PS); polycarbonate (PC); polyurethane (PU); polyimide (PI); polyacrylates including polymethylmethacrylate (PMMA); polyesters including polybutylene terephthalate (PBT) and polyethylene terephthalate (PET); polyalkylenes including polyethylene (PE) and polypropylene (PP); polyvinyl chloride (PVC), polyvinylidene fluoride (PVdF) containing vinyl polymer; It is preferably selected from the group consisting of polydimethylsiloxane (PDMS) and mixtures thereof.

After drying the polymer resin, it is cured and demolded (S10).

The polymer resin coated on the super water-repellent mold is dried through S9 to remove all of the solvent, and cured and demolded to obtain a super-water-repellent material. The super water-repellent material thus obtained includes a micro-pillar formed by an anodizing micro-pattern and a nano-pillar shape obtained through an anodizing nano-pattern, and has super-water-repellent performance due to the shape. Although the micro filler alone can have super water-repellent performance, in general, when the nano-pillar is mixed in the micro filler, superior super water repellency is exhibited.

The following describes the embodiments of the present invention in more detail.

<Example>

As a method for manufacturing a mold and a super water-repellent material according to an embodiment of the present invention, an aluminum plate having a purity of 99.999% and a thickness of 1.0 mm is used as a metal for the mold. The aluminum plate was washed in order using alcohol, acetone and aqua regia, and then heat treated at 420°C for 3 hours.

After that, in order to reduce the surface roughness of the aluminum sheet, which is a metal for mold, perchloric acid (HClO ₄ ): ethanol (EtOH) = 1: 4 Immerse the aluminum sheet in the mixed solution electrolyte and apply a voltage of 20V, and 30 minutes After electrolytic polishing, the mixture was dried at 120° C. for 1 hour. Thereafter, a 3 μm photoresist is coated on the aluminum plate through a spin coating method, and soft baking is performed at 50° C. for 20 minutes and at 90° C. for 20 minutes. Thereafter, as shown in FIG. 4, a negative photomask in which a circle of 8 μm is hexagonally arranged at a cycle of 24 μm is covered on the top of the photoresist, irradiated with UV-light for 100 seconds, developed for 120 seconds, washed and then 80 After drying at 20° C. for 20 minutes at 120° C. for 30 minutes and slowly cooling to room temperature, photoresist negative photosensitive micro patterns as shown in FIGS. 5A and 5B were prepared.

Subsequently, the surface of the aluminum plate covered with the photosensitive micro-pattern of the photoresist was immersed in a 0.1M phosphoric acid solution and anodized while applying a voltage of 195V for 10 hours to prepare the surface of the first anodized layer shown in FIG. The first anodized layer was removed by etching for 1 hour using a phosphoric acid solution to form an anodized micro pattern in a tube shape having a semi-spherical shape with a bottom of 8 µm in depth and a nano size of 500 nm as shown in FIGS. 7A and 7B. A surface composed of seeds was formed.

Through the process of immersing the aluminum plate in which the anodized micro-pattern is formed in 0.1M phosphoric acid solution again, anodizing while applying a voltage of 195V for 15 minutes to form a second anodized layer, and etching for 40 minutes in 0.1M phosphoric acid solution. The pores formed in the second anodization layer were enlarged. Thereafter, the anodization and etching processes were repeated twice to form conical nanopores having a diameter of 350 nm and a depth of 1.2 µm as shown in FIGS. 8B and 9 of FIGS. 8A and 8B. As shown in FIG. 8, an alumina mold was prepared in which a hemispherical anodized micro pattern and a cone-shaped anodized nano pattern were mixed.

After that, the aluminum plate having the surface of the anodized micro pattern and nano pattern mixed structure was treated for 1 hour in a mixed solution mixed with hydrogen peroxide (H ₂ O ₂ ): sulfuric acid (H ₂ SO ₄ ) = 1: 1 weight ratio to the surface. After removing the adsorbed oxygen, the residual oxygen was removed again by putting it in a vacuum desiccator for 2 hours.

Thereafter, the surface of the aluminum plate was coated with an alkyl silane using a solution in which 2 drops of silane were dropped on 20 g of toluene, and then it was washed with alcohol and dried at 120° C. for 2 hours.

After washing the PMMA (Poly methyl methacrylate) and PC (Polycarbonate) substrates, they are mounted on a nanoimprint device, maintained at 130 to 170° C. for 20 minutes, and then a pressure of 30 bar is applied for 5 minutes. The substrate was then cooled to room temperature over 15 minutes, washed with water, and dried at 50° C. again, as shown in FIGS. 10A, 10B, 11A, and 11B, embossed anodized micro patterns in a hemispherical shape, and conical shape A surface in which anodized nano patterns were mixed was prepared. As a result of measuring the water contact angle of the substrate having a superhydrophobic surface, a value of 153? in PMMA and 151° in PC was obtained.

Conventionally, a mold for forming a fine super water-repellent pattern has formed a new micro pattern through an etching process in a state in which a photoresist forms a photosensitive micro pattern. However, during the etching process, the photoresist was detached from the mold metal, and thus a micro pattern having a desired shape could not be obtained. In addition, because the photoresist is separated, the time for etching is short, so that a micro pattern cannot be formed to a desired depth. However, in the case of the present invention, since an anodization micro pattern is formed through anodization in the presence of a photoresist, there is no problem that the photoresist falls off by a solution used for etching, and thus an anodization process can be performed for a long time. . Through this, a mold having a deeply depressed anodized micro pattern and a nano pattern can be obtained, and a material having increased water repellency can also be obtained through the mold.

Claims (24)

In the method for manufacturing a super water-repellent mold,
Bonding a photoresist to a mold metal surface;
Forming a photosensitive micro pattern by photosensitive the photoresist through lithography;
Forming a first anodized layer through anodization on the photosensitive micro pattern;
After removing the first anodized layer, the photoresist remaining in the mold metal is removed to form a anodized micro pattern that is deeper than the photosensitive micro pattern and includes nano seeds, wherein the anodized micro pattern is a hemisphere. It is formed into a shape, the depth of 0.1 to 50㎛, the width of 0.1 to 100㎛, and recessed at intervals of 0.1 to 50㎛;
A second anodization layer including an anodization nano pattern is formed on the anodization micro pattern including the nanoseed through anodization, and anodization conditions for forming the second anodization layer are for forming the first anodization layer. The same as the anodizing condition, and the anodized nano-pattern made of nanopores is formed in a convex cylindrical shape or a conical shape with a pointed end in a hemisphere shape of the anodized micro-pattern while the pores, which are unit cells, are 0.1 to 10. A depth of µm, a diameter of 0.1 to 1000 nm, and a depression of 0.1 to 1000 nm;
Adjusting the diameter of the nanopores by etching the anodized nanopattern made of nanopores;
Anodization and etching are repeated to adjust the shape and size of the anodized nano-pattern, but the diameter of the nano-pores is adjusted to a depth ratio of 1: 1 to 1: 10; Mold manufacturing method. According to claim 1,
Before the step of bonding a photoresist to the metal for the mold,
The method for manufacturing a super water-repellent mold further comprising the step of cleaning and polishing the metal surface for the mold. According to claim 2,
The polishing step,
It is made through mechanical polishing or electropolishing,
The method of manufacturing a super water-repellent mold, characterized in that the metal surface for the mold is polished to have a surface roughness of 0.1 nm to 10 μm. According to claim 1,
The lithography method for manufacturing a super water-repellent mold, characterized in that at least one of UV light and electron beam is used. According to claim 1,
The mold metal is Al, W, Ti, Ta, Hf, Nb, Zr and a method for producing a super water-repellent mold, characterized in that selected from the group consisting of a mixture thereof. The method of claim 5,
First, characterized in that at least one of Cu, Mn, Si, Mg, Cr, Zn, Li, V, Mo, Ga, Ge, Fe, Co, Ni, C, and O elements is further mixed with the mold metal. Method for manufacturing a receiving mold. According to claim 1,
The mold metal is a method for manufacturing a super water-repellent mold, characterized in that it is made of a flat plate or a roll. According to claim 1,
The first anodization layer is a method for manufacturing a super water-repellent mold, characterized in that etching is removed through a phosphoric acid solution. delete delete The method of any one of claims 1 and 8,
The anodization uses a solution selected from the group consisting of phosphoric acid, oxalic acid, sulfuric acid, selenic acid, malonic acid, phosphorus-acetic acid, tartaric acid, citric acid, etidronic acid, and mixtures thereof at concentrations of 0.001M to 5M, -50 Method for producing a super water-repellent mold, characterized in that it is made by applying a voltage of 1 to 500 V for 1 second to 1 week while maintaining a temperature of 300 to 300°C. According to claim 1,
After the step of adjusting the diameter and the depression depth of the nanopores,
In order to manufacture a mold having a higher strength than the super water-repellent mold using the super-water-repellent mold, after depositing or coating a polymer, metal, alloy or ceramic material on the pores and surfaces of the super-water-repellent mold, the super-water-repellent mold After removing the to prepare an embossed mold of a polymer, metal, alloy or ceramic material, the method of manufacturing a super water-repellent mold, characterized in that to produce an embossed mold of a metal, alloy or ceramic material again in the embossed mold. The method of claim 12,
The metal is selected from the group consisting of Al, Mn, Ti, W, Cu, Ni, Cr, and mixtures thereof, and the polymer is from the group consisting of polydimethylsiloxane (PDMS), polyamide (PA), polytetrafluoroethylene (PTFE), and mixtures thereof. Is selected, the ceramic is SiC, DLC, diamond, and a method for producing a super water-repellent mold, characterized in that is selected from the group consisting of a mixture thereof. According to claim 1,
After the step of adjusting the diameter and the depression depth of the nanopores,
Method for manufacturing a super-water-repellent mold further comprising the step of coating a release film on the metal for the mold to improve the desorption property of the polymer material for super-water-repellent from the super-water-repellent mold. delete delete delete delete delete In the method for producing a material for super water-repellent using a super water-repellent mold,
Bonding a photoresist to a mold metal surface;
Forming a photosensitive micro pattern by photosensitive the photoresist through lithography;
Forming a first anodized layer through anodization on the photosensitive micro pattern;
After removing the first anodized layer, the photoresist remaining in the mold metal is removed to form a anodized micro pattern that is deeper than the photosensitive micro pattern and includes nano seeds, wherein the anodized micro pattern is a hemisphere. It is formed into a shape, the depth of 0.1 to 50㎛, the width of 0.1 to 100㎛, and recessed at intervals of 0.1 to 50㎛;
A second anodization layer including an anodization nano pattern is formed on the anodization micro pattern including the nanoseed through anodization, and anodization conditions for forming the second anodization layer are for forming the first anodization layer. The same as the anodizing condition, and the anodized nano-pattern made of nanopores is formed in a convex cylindrical shape or a conical shape with a pointed end in a hemisphere shape of the anodized micro-pattern while the pores, which are unit cells, are 0.1 to 10. A depth of µm, a diameter of 0.1 to 1000 nm, and a depression of 0.1 to 1000 nm;
Adjusting the diameter of the nanopores by etching the anodized nanopattern made of nanopores;
Anodic oxidation and etching are repeated to adjust the shape and size of the anodized nano-pattern, but the diameter: depth ratio of the nano-pores is adjusted to 1: 1 to 1: 10, and
A method of manufacturing a super water-repellent material using a super-water-repellent mold comprising coating and demolding a polymer resin on a mold on which the anodized micro-pattern and anodized nano-pattern are formed. delete The method of claim 20,
The coating is a polymer solution method, a thermal imprinting method (Thermal imprinting), UV-imprinting method or a method for producing a super-water-repellent material using a water-repellent mold, characterized in that made through a chemical imprinting method. The method of claim 20,
The polymer resin is polyamide (PA); polystyrene (PS); polycarbonate (PC); polyurethane (PU); polyimide (PI); polyacrylates including polymethylmethacrylate (PMMA); polyester including polybutylene terephthalate (PBT) and polyethylene terephthalate (PET); polyalkylenes including polyethylene (PE) and polypropylene (PP); polyvinyl chloride (PVC), polyvinylidene fluoride (PVdF) containing vinyl polymer; Polydimethylsiloxane (PDMS) and a method for producing a super water-repellent material using a super water-repellent mold, characterized in that is selected from the group consisting of a mixture thereof. delete

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