KR102534946B1 - Manufacturing method of nano mold and nano mold produced thereby - Google Patents

Abstract

The present invention relates to a method for manufacturing a nanomold having excellent physical and mechanical properties, such as hardness and modulus of elasticity, and a nanomold manufactured thereby.

Description

Manufacturing method of nanomold and nanomold produced thereby

The present invention relates to a method for manufacturing a nanomold and a nanomold manufactured thereby.

The reason why we can see various colors is because there are various materials around us that absorb different wavelengths of light. When white light hits a material, it absorbs only light of a specific wavelength according to its own material, and the color of the light of the wavelength reflected without being absorbed is visible. If the wavelength of light absorbed by a material can be artificially changed, various colors can be created from the same material.

There are two basic methods of implementing these colors, which are classified into two types: a method using traditional dyes or pigments and a method using microstructures. While dyes and pigments have been used by mankind for a long time, microstructure is a mechanism of color that exists mainly in nature, such as in silkworms and morpho butterflies. Compared to the large amount of dyes and pigments used, they are harmful to the human body and pose a threat to the environment due to problems such as recycling. In addition, dyes and pigments have the disadvantage of degrading over time.

If structural colors are used in products, information using color can be conveyed without using colorants or pigments. It is possible to maintain the original function while eliminating the disadvantages of dyes and pigments. Applying structural colors to plastic packaging containers that are used a lot, such as beverage bottles, disposable cups and food packaging materials, can greatly contribute to environmental protection.

A method of realizing the structural color is to form a nano-sized lattice structure, nano-hole, or nano-dimple on the surface. The more regular the period of the pattern, the clearer the color development effect at a predetermined angle of reflection or viewing angle. The structural color due to the nanostructure on the surface is observed as a specific color by a different reflection angle for each wavelength according to the viewing angle, and is recognized by humans as iridescent color according to the reflection angle.

That is, a structural color may be formed by implementing a nanopattern on the outer surface of the plastic product. As such a method, there is a method of attaching a separate film or piece on which a structural color image is formed to a product, and a method of forming a single body with a nanostructured pattern on the surface of the product and the product. Compared to the separate manufacturing and attachment method, forming a single material structure has high efficiency, such as fewer restrictions on applied products and a shorter manufacturing process.

Information transmission elements of products include pictures, letters, figures, emblems, logos, etc. These image elements must be implemented with appropriate resolution.

It is preferable to form the structural color optical element for image on the outside rather than the inside in plastic bottles, cups, food containers, and the like. When positioned inside, the nanopattern may come into contact with the material inside, and the desired optical properties may be deformed, abraded, or separated, and mixed with the material. It may be located inside if there is no contact with the internal material or if there is a structure capable of preventing contact.

If located outside the product, the nanopattern may be damaged during transportation or use of the product, but it is not a big problem considering the short-term use or use pattern of the application target.

In order to simultaneously form the nanostructure on the surface during the molding process of a product, an insert on which a nanopattern is formed, that is, a nanomold, is required as a mold component. These nano-molds require sufficient strength and durability over a wide temperature and pressure range required for thermoplastic resin molding.

Although lithography technology used in a conventional semiconductor process is necessary for making a prototype of a pattern, there is a problem in that it is not suitable as a method of manufacturing various molds required for various images and products.

In addition, as a polymer forming technology, nanoimprint lithography technology and nanoimprint mold manufacturing technology required therefor can be applied, but the strength and durability are insufficient in the forming process in which high pressure and heat are applied compared to the nanoimprint process. In addition, since the same number of master patterns are required for multiple types of image molds, there is a problem in that economic efficiency is not good.

The present invention provides a method for manufacturing a nanomold having excellent physical and mechanical properties, such as hardness and modulus of elasticity, and the nanomold manufactured by the method.

However, the problem to be solved by the present invention is not limited to the above-mentioned problem, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

An exemplary embodiment of the present invention includes preparing a master mold having a pattern including a plurality of nanostructures; a first transfer step of transferring the pattern of the master mold to a soft mold; Applying a photocurable coating solution on a substrate and pre-curing to form a pre-cured coating layer; a second transfer step of transferring the first transferred pattern of the soft mold to the pre-cured coating layer; and preparing a nanomold by post-curing the pre-cured coating layer, wherein the pattern including the plurality of nanostructures exhibits a structural color.

In addition, one embodiment of the present invention provides a nanomold manufactured by the above method.

The manufacturing method according to an exemplary embodiment of the present invention can manufacture a nanomold having excellent physical and mechanical properties such as hardness and elastic modulus at low cost.

In addition, the nanomold according to an exemplary embodiment of the present invention may have excellent physical and mechanical properties such as hardness and modulus of elasticity.

Effects of the present invention are not limited to the above-mentioned effects, and effects not mentioned will be clearly understood by those skilled in the art from the present specification and accompanying drawings.

1 is a schematic diagram of a method for manufacturing a nanomold according to the present invention.
2 schematically shows a composition of a photocurable coating solution used in the method for manufacturing a nanomold according to the present invention and a process of forming a coating layer using the photocurable coating solution.
3 and 4 schematically show examples of implementation of structural color-based images and text implemented on nanomolds according to the present invention.
5 schematically illustrates an embodiment of manufacturing a product having a structural color-based image using a nanomold according to the present invention.
6 shows the thickness of the coating layer according to the change in the nanoparticle content of the nanomold according to the present invention.
7 is a photograph showing structural color-based images implemented on nanomolds according to Examples 1 and 7 to 9;
8 is a photograph showing structural color-based characters implemented on a nanomold according to Example 1;
9 shows a SEM image of a nanopattern formed on a nanomold according to Comparative Example 1.
10 shows a SEM image of a nanopattern formed on a nanomold according to Example 1.
11 shows the modulus of elasticity according to the change in nanoparticle content of nanomolds according to Comparative Example 1, Comparative Example 2, Example 1, Example 3, Example 5, and Example 6.
12 shows the hardness according to the change in nanoparticle content of nanomolds according to Comparative Example 1, Comparative Example 2, Example 1, Example 3, Example 5, and Example 6.

Throughout the present specification, when a certain component is said to "include", it means that it may further include other components without excluding other components unless otherwise stated.

Throughout the present specification, when a member is said to be located “on” another member, this includes not only a case where a member is in contact with another member, but also a case where another member exists between the two members.

Throughout the present specification, the unit "parts by weight" may mean the ratio of the weight of each component.

Hereinafter, the present invention will be described in more detail.

An exemplary embodiment of the present invention includes preparing a master mold having a pattern including a plurality of nanostructures; a first transfer step of transferring the pattern of the master mold to a soft mold; Applying a photocurable coating solution on a substrate and pre-curing to form a pre-cured coating layer; a second transfer step of transferring the first transferred pattern of the soft mold to the pre-cured coating layer; and preparing a nanomold by post-curing the pre-cured coating layer, wherein the pattern including the plurality of nanostructures exhibits a structural color.

According to an exemplary embodiment of the present invention, the pattern including the plurality of nanostructures may exhibit a structural color. Specifically, the pattern including the plurality of nanomaterials refracts, disperses, and scatters light of a specific wavelength among visible light that contacts the surface, so that the light of the specific wavelength is specified by interference and diffraction. It may be to implement the structural color of the color. More specifically, the structural color may be one in which light of a specific wavelength is absorbed through plasmon resonance and light of the remaining wavelengths is reflected or transmitted according to the shape of the plurality of nanostructures and patterns.

According to an exemplary embodiment of the present invention, the master mold having a pattern including a plurality of nanostructures may be formed with a single pattern including a plurality of nanostructures. Specifically, the nanostructure included in a single pattern including the plurality of nanostructures may have a shape such as a unidirectional diffraction grating, a hole, a cylinder, or a cone. The diffraction grating is a unidirectional grating structure, and its cross section may have a square, triangular or other shape. In addition, the plurality of nanostructures may have cross sections other than circles, such as squares or triangles.

According to an exemplary embodiment of the present invention, the pattern including the plurality of nanostructures may be reflected in a reverse image form on a final molded product through a series of transfer processes. Optical performance, such as brightness and sharpness of a structural color formed on a final molded article, is related to diffraction efficiency, and the diffraction efficiency may depend on the geometry of a pattern including the plurality of nanostructures. Therefore, the design of the plurality of nanostructures can be designed in terms of optical effects. For example, in the case of a grating type, the design factors may be the width (w), height (h), and pitch (p) of the pattern, and in the case of an array type, the diameter (d), depth (h), and pitch (p) can be Typically, the pitch is 0.3 to 3 μm, the width or diameter is 0.1 to 1 μm, and the depth or height constitutes a width or diameter and slenderness ratio of 0.3:1 or more may be suitable. Also, it may be suitable that the depth or height is at least 30% relative to the width or diameter.

According to an exemplary embodiment of the present invention, the pattern including the plurality of nanostructures includes a first region in which a plurality of first nanostructures exhibiting structural colors are formed, and a plurality of second nanostructures different from the first nanostructures are formed. It may include a second area. Specifically, the pattern including the plurality of nanostructures includes a first region formed with a plurality of first nanostructures exhibiting a structural color and a plurality of second nanostructures exhibiting a structural color different from the structural color of the first region. It may include a second area. Specifically, the pattern including the plurality of nanostructures may include a first region in which a plurality of first nanostructures exhibiting a structural color are formed and a second region in which a plurality of second nanostructures not exhibiting a structural color are formed. there is. The pattern includes a first region in which a plurality of first nanostructures are formed and a second region in which a plurality of second nanostructures are formed, such that a region exhibiting a specific structural color, a region exhibiting a different structural color, and a region not exhibiting a structural color. It may be possible to implement a structural color-based pattern in which regions appear regularly or irregularly.

According to an exemplary embodiment of the present invention, the first region in which the plurality of first nanostructures exhibiting the structural color are formed may be formed with a plurality of first nanostructures having a nano-dimple, diffraction grating, hole, cylinder, or cone shape. . When a plurality of first nanostructures having the above-described shape are formed, a specific structural color may be realized in the first region.

According to an exemplary embodiment of the present invention, the first region in which the plurality of first nanostructures exhibiting the structural color are formed has a pitch of 0.3 μm or more and 3 μm or less, a diameter or width of 0.1 μm or more and 1 μm or less, and a height or depth of 30 nm or more. A plurality of first nanostructures of 600 nm or less may be formed. More specifically, the pitch of the first nanostructure is 0.3 μm or more, 0.5 μm or more, 0.7 μm or more, 1 μm or more, 1.2 μm or more, 1.5 μm or more, 1.7 μm or more, 2 μm or more, 2.2 μm or more, or 2.5 μm or more. The pitch of the first nanostructure may be 3 μm or less, 2.7 μm or less, 2.5 μm or less, 2.3 μm or less, 2.1 μm or less, 1.9 μm or less, 1.7 μm or less, 1.5 μm or less, 1.3 μm or less, or 1 μm or less. It may be below. More specifically, the diameter or width of the first nanostructure is 0.1 μm or more, 0.2 μm or more, 0.3 μm or more, 0.4 μm or more, 0.5 μm or more, 0.6 μm or more, 0.7 μm or more, 0.8 μm or more, or 0.9 μm or more. The diameter or width of the first nanostructure may be 1 μm or less, 0.9 μm or less, 0.8 μm or less, 0.7 μm or less, 0.6 μm or less, 0.5 μm or less, 0.4 μm or less, 0.3 μm or less, or 0.2 μm or less. there is. More specifically, the height or depth of the first nanostructure is 30 nm or more, 50 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, It may be 450 nm or more or 500 nm or more, and the height or depth of the first nanostructure is 600 nm or less, 550 nm or less, 500 nm or less, 450 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less It may be less than nm or less than 100 nm. When the plurality of first nanostructures have a pitch, diameter or width, height or depth within the aforementioned range, a structural color may be implemented in the first region.

According to an exemplary embodiment of the present invention, the first region in which the plurality of first nanostructures exhibiting the structural color are formed has a plurality of first nanostructures having a ratio of a diameter or width to a height or depth of 0.3:1 or more and 1:1 or less. may have been formed. Specifically, the ratio of the diameter or width to the height or depth of the plurality of first nanostructures is 0.5:1 or more, 1:1 or less, 0.7:1 or more, 1:1 or less, 0.9:1 or more, 1:1 or less, 0.3:1 It may be more than 0.9:1 or less, 0.3:1 or more and 0.7:1 or less, 0.3:1 or more and 0.5:1 or less, or 0.5:1 or more and 0.7:1 or less. When the ratio of the diameter or width to the height or depth of the plurality of first nanostructures satisfies the aforementioned range, a structural color may be implemented in the first region.

According to an exemplary embodiment of the present invention, the second region in which a plurality of second nanostructures are formed may be formed with a plurality of second nanostructures having a nano-dimple, diffraction grating, hole, cylinder, or cone shape. When a plurality of second nanostructures having the aforementioned shape are formed, a structural color may not be implemented in the second region or a specific structural color different from that of the first region may be implemented.

According to an exemplary embodiment of the present invention, the second region in which a plurality of second nanostructures having a structural color different from that of the first region are formed has a pitch of 0.3 μm or more and 3 μm or less, and a diameter or width of 0.1 μm or more and 1 μm. Hereinafter, a plurality of second nanostructures having a height or depth of 30 nm or more and 600 nm or less may be formed. More specifically, the pitch of the second nanostructure is 0.3 μm or more, 0.5 μm or more, 0.7 μm or more, 1 μm or more, 1.2 μm or more, 1.5 μm or more, 1.7 μm or more, 2 μm or more, 2.2 μm or more, or 2.5 μm or more. The pitch of the second nanostructure may be 3 μm or less, 2.7 μm or less, 2.5 μm or less, 2.3 μm or less, 2.1 μm or less, 1.9 μm or less, 1.7 μm or less, 1.5 μm or less, 1.3 μm or less, or 1 μm or less. It may be below. More specifically, the diameter or width of the second nanostructure is 0.1 μm or more, 0.2 μm or more, 0.3 μm or more, 0.4 μm or more, 0.5 μm or more, 0.6 μm or more, 0.7 μm or more, 0.8 μm or more, or 0.9 μm or more. The diameter or width of the second nanostructure may be 1 μm or less, 0.9 μm or less, 0.8 μm or less, 0.7 μm or less, 0.6 μm or less, 0.5 μm or less, 0.4 μm or less, 0.3 μm or less, or 0.2 μm or less. there is. More specifically, the height or depth of the second nanostructure is 30 nm or more, 50 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, It may be 450 nm or more or 500 nm or more, and the height or depth of the second nanostructure is 600 nm or less, 550 nm or less, 500 nm or less, 450 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less It may be less than nm or less than 100 nm. When the plurality of second nanostructures have a pitch, diameter or width, height or depth within the aforementioned range, a specific structural color different from that of the first region may be implemented in the second region.

According to an exemplary embodiment of the present invention, in the second region in which a plurality of second nanostructures having a structural color different from that of the first region are formed, the ratio of the diameter or width to the height or depth is 0.3:1 or more 1:1 A plurality of second nanostructures described below may be formed. Specifically, the ratio of the diameter or width to the height or depth of the plurality of second nanostructures is 0.5:1 or more, 1:1 or less, 0.7:1 or more, 1:1 or less, 0.9:1 or more, 1:1 or less, 0.3:1 It may be more than 0.9:1 or less, 0.3:1 or more and 0.7:1 or less, 0.3:1 or more and 0.5:1 or less, or 0.5:1 or more and 0.7:1 or less. When the ratio of the diameter or width to the height or depth of the plurality of second nanostructures satisfies the aforementioned range, a structural color different from that of the first region may be realized in the second region.

According to an exemplary embodiment of the present invention, the second region in which the plurality of second nanostructures not exhibiting the structural color are formed has a pitch of 100 nm or more and 500 nm or less, a diameter or width of 10 nm or more and 300 nm or less, and a height or depth of 10 nm. A plurality of second nanostructures of greater than or equal to 300 nm or less may be formed. More specifically, the pitch of the second nanostructure may be 100 nm or more, 150 nm or more, 200 nm or more, 250 nm or more, 300 nm or more, 350 nm or more, 400 nm or more, or 450 nm or more, and The pitch of the structure may be 500 nm or less, 450 nm or less, 400 nm or less, 350 nm or less, 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less. More specifically, the diameter or width of the second nanostructure may be 10 nm or more, 30 nm or more, 50 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, or 250 nm or more, and the second nanostructure The diameter or width of may be 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less. More specifically, the height or depth of the second nanostructure may be 10 nm or more, 30 nm or more, 50 nm or more, 100 nm or more, 150 nm or more, 200 nm or more, or 250 nm or more, and the second nanostructure The height or depth of may be 300 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, 100 nm or less, or 50 nm or less. When the plurality of second nanostructures have a pitch, diameter or width, height or depth within the aforementioned range, the structure color may not be implemented in the second region.

According to one embodiment of the present invention, the first transfer step of transferring the pattern of the master mold to the soft mold; may be performed by an imprinting lithography method. When the first transfer step is performed by the above-described method, the soft mold may have a pattern representing a structural color formed on the master mold and a plurality of nanostructures in reversed form. Specifically, by forming a pattern including a plurality of nanostructures that are opposite to the pattern of the master mold on the soft mold by the first transfer step, the structural color is realized on the soft mold that has passed through the first transfer step. it may be

According to an exemplary embodiment of the present invention, the material of the soft mold is thermosetting PDMS (Polydimethylsiloxane), h-PDMS or x-PDMS with modified physical properties, PUA (polyurethane acrylate) as a UV curable resin, and PFPE, a UV curable fluororesin. (perfluoro polyether), polyhedral oligomeric silsesquioxane (POSS), or Ormocer-based ormostamp or ormocomp, which are commercial products composed of organic-inorganic composite materials. When the soft mold is formed of the above-described material, the formation of the soft mold may be facilitated, and the pattern transfer of the master mold may be more easily performed.

According to one embodiment of the present invention, the first transfer step; may further include a step of surface treating the soft mold. Specifically, the surface treatment may be a silane-based self-assembled monolayer or hydrophobic plasma treatment. More specifically, the surface treatment may be a plasma treatment using oxygen (O ₂ ) gas or a plasma treatment using carbon tetrafluoride (CF ₄ ) gas on the surface of the soft mold. Through the above-described surface treatment, adhesion between the soft mold and a shielding material described later may be improved, and releasability may be improved in a subsequent pattern transfer step.

According to an exemplary embodiment of the present invention, applying a photocurable coating solution on the substrate and pre-curing to form a pre-cured coating layer; preparing a master mold having a pattern including the plurality of nanostructures; and a first transfer step of transferring the pattern of the master mold to the soft mold; it may be performed as a separate process prior to, subsequent to, or simultaneously with.

According to an exemplary embodiment of the present invention, the substrate may be mold steel such as carbon steel, stainless steel, copper alloy, beryllium copper, aluminum alloy, or nickel alloy, 3D printing material, or synthetic resin such as polyimide film. More specifically, the substrate may be stainless steel. In the case of a material having physical properties suitable for coating and transfer described later, it may be used without limitation. When the substrate is formed of the above material, the surface roughness of the substrate may be low enough to be suitable for coating, and physical and mechanical properties such as hardness and elastic modulus of the nanomold may be excellent.

According to one embodiment of the present invention, the substrate may be formed in a flat or curved surface. Specifically, the substrate may be formed in a curved surface. When the substrate is formed in the above-described shape, patterns for implementing structural colors can be transferred to the surface of products having various shapes, and various kinds of nano-molds can be manufactured at low cost.

According to an exemplary embodiment of the present invention, the photocurable coating solution may include a photocurable composition including an acrylic compound and a photopolymerization initiator, and a solvent in which nanoparticles are dispersed. Specifically, the photocurable composition may include an acrylic compound and a photopolymerization initiator. More specifically, the photocurable composition may include an acrylic compound monomer, an acrylic compound oligomer, a photopolymerization initiator, or a mixture thereof. As long as the photocurable composition does not undergo chemical reactions such as curing, precipitation, bubbles, discoloration, etc. when mixed with the solvent in which the nanoparticles are dispersed, and is not separated from each other, a commercially available photocurable composition may also be appropriately selected. For example, the photocurable composition may include ormostamp, a commercially available photocurable resin for nanoimprint molds based on PUA (polyurethane acrylate) or Ormocer (organically modified ceramics). In the case of using the above-described photocurable composition, through the second transfer step and additional curing step described later, the pattern formed on the soft mold may be easily transferred to the pre-cured coating layer, and the elastic modulus and hardness may be used for resin molding. A nanomold having excellent mechanical properties required for use as a mold can be manufactured.

According to an exemplary embodiment of the present invention, the diameter of the nanoparticles may be greater than or equal to 5 nm and less than or equal to 30 nm. Specifically, the diameter of the nanoparticles is 5 nm or more and 30 nm or less, 10 nm or more and 30 nm or less, 15 nm or more and 30 nm or less, 20 nm or more and 30 nm or less, 25 nm or more and 30 nm or less, 5 nm or more and 25 nm or less. , 5 nm or more and 20 nm or less, 5 nm or more and 15 nm or less, 5 nm or more and 10 nm or less, 10 nm or more and 25 nm or less, 15 nm or more and 25 nm or less, or 20 nm or more and 25 nm or less. When the diameter of the nanoparticles satisfies the aforementioned range, dispersibility of the nanoparticles in the solvent and the photocurable coating solution may be excellent, and physical properties such as mechanical strength of the coating layer and nanomold may be excellent. .

According to an exemplary embodiment of the present invention, the content of the nanoparticles may be 10 vol% or more and 60 vol% or less based on the total volume of the photocurable composition. Specifically, the content of the nanoparticles is 10 vol% or more, 13 vol% or more, 15 vol% or more, 18 vol% or more, 20 vol% or more, 25 vol% or more, based on the total volume of the photocurable composition. 30 vol% or more, 35 vol% or more, 40 vol% or more, 45 vol% or more, or 50 vol% or more, the content of the nanoparticles based on the total volume of the photocurable composition, 60 vol% or less, 50 vol % or less, 45 vol % or less, 40 vol % or less, 35 vol % or less, 30 vol % or less, 25 vol % or less, 20 vol % or less, 18 vol % or less, or 15 vol % or less. When the content of the nanoparticles satisfies the aforementioned range, dispersibility of the nanoparticles in the solvent and the photocurable coating solution may be excellent, and physical properties such as mechanical strength of the coating layer and nanomold may be excellent. .

According to an exemplary embodiment of the present invention, the content of the nanoparticles may be 5 parts by weight or more and 50 parts by weight or less based on 100 parts by weight of the solvent in which the nanoparticles are dispersed. Specifically, the content of the nanoparticles is 5 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, 25 parts by weight or more, 30 parts by weight or more, based on 100 parts by weight of the solvent in which the nanoparticles are dispersed. or more, 35 parts by weight or more, or 40 parts by weight or more, and the content of the nanoparticles is 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less, based on 100 parts by weight of the solvent in which the nanoparticles are dispersed. It may be less than 30 parts by weight, less than 25 parts by weight. More specifically, when the content of the nanoparticles satisfies the aforementioned range, the dispersibility of the nanoparticles in the solvent and the photocurable coating solution may be excellent, and the physical properties such as mechanical strength of the coating layer and the nanomold may be improved. can be excellent

According to an exemplary embodiment of the present invention, the content of the nanoparticles may be 25 parts by weight or more and 1000 parts by weight or less based on 100 parts by weight of the photocurable composition. Specifically, the content of the nanoparticles is 25 parts by weight or more, 30 parts by weight or more, 35 parts by weight or more, 40 parts by weight or more, 45 parts by weight or more, 50 parts by weight or more, 55 parts by weight or more based on 100 parts by weight of the photocurable composition. Part by weight or more, 60 parts by weight or more, 65 parts by weight or more, 70 parts by weight or more, 75 parts by weight or more, or 80 parts by weight or more, the content of the nanoparticles based on 100 parts by weight of the photocurable composition, 1000 parts by weight 900 parts by weight or less, 800 parts by weight or less, 700 parts by weight or less, 600 parts by weight or less, 500 parts by weight or less, 400 parts by weight or less, 300 parts by weight or less, 200 parts by weight or less, or 100 parts by weight or less. . The content of the nanoparticles may be 30 parts by weight or more based on 100 parts by weight of the photocurable composition. When the content of the nanoparticles satisfies the aforementioned range, dispersibility of the nanoparticles in the solvent and the photocurable coating solution may be excellent, and physical properties such as mechanical strength of the coating layer and nanomold may be excellent. .

According to an exemplary embodiment of the present invention, the weight ratio of the photocurable composition and the solvent in which the nanoparticles are dispersed may be 1:2 or more and 1:20 or less. Specifically, the weight ratio of the photocurable composition and the solvent in which the nanoparticles are dispersed is 1:2 or more, 1:20 or less, 1:3 or more, 1:20 or less, 1:4 or more, 1:20 or less, 1:5 or more 1 :20 or less, 1:7 or more, 1:20 or less, 1:10 or more, 1:20 or less, 1:12 or more, 1:20 or less, 1:15 or more, 1:20 or less, 1:3 or more, 1:15 or less, 1 :3 or more and 1:12 or less, 1:3 or more and 1:10 or less, 1:3 or more and 1:7 or less, or 1:3 or more and 1:5 or less. As the added amount of the solvent in which the nanoparticles are dispersed increases, the viscosity of the photocurable composition may decrease, and accordingly, the coating thickness of the coating layer may decrease. When the weight ratio of the photocurable composition and the solvent in which the nanoparticles are dispersed satisfies the above range, the coating layer may have a coating thickness suitable for molding, and physical properties such as mechanical strength of the nanomold may be excellent.

According to an exemplary embodiment of the present invention, the nanoparticles may include at least one of ZrO ₂ , TiO ₂ , Al ₂ O ₃ and SiO ₂ . Specifically, the nanoparticles may include ZrO ₂ . When the nanoparticles include the above materials, the coating layer and the nanomold may have excellent mechanical properties, excellent chemical stability, and high transmittance to ultraviolet or visible light.

According to an exemplary embodiment of the present invention, the solvent may be Ethanol, Methyl Isobutyl Ketone (MIBK), Propylene Glycol Monomethyl Ether Acetate (PGMEA), Propylene Glycol Monomethyl Ether (PGME), or a mixture thereof. When the solvent is of the above-described type, evaporation may be facilitated in the process of being coated on the surface of the substrate and then cured, the nanoparticles may be uniformly dispersed, and the photocurable coating solution may have a low viscosity. Maintaining the moldability can be excellent in the process of coating and pattern transfer by soft mold.

According to an exemplary embodiment of the present invention, the coating is drop coating or spin coating. It may be performed by a coating method using a dip coating, a slot die, or a blade. Specifically, the coating may be spin coating, and the spin coating may be performed at 100 rpm or more and 5000 rpm or less for a time of 10 seconds or more and 5 minutes or less. The coating thickness may be changed according to the type of the solvent, the amount of nanoparticles added, the coating method, and the coating speed.

According to an exemplary embodiment of the present invention, the pre-curing may be thermal curing. Specifically, the pre-curing may be performed by coating the photocurable coating solution on the substrate and then heating and curing the coating layer at a predetermined temperature for a predetermined time in order to adjust the physical properties of the pre-curing coating layer to be suitable for molding. there is.

According to an exemplary embodiment of the present invention, the pre-curing may be performed at a temperature of 50 °C or more and 90 °C or less for a time of 1 minute or more and 1 hour or less. Specifically, the pre-curing is 50 ° C or more and 90 ° C or less, 60 ° C or more and 90 ° C or less, 70 ° C or more and 90 ° C or less, 80 ° C or more and 90 ° C or less, 50 ° C or more and 80 ° C or less, 50 ° C or more and 70 ° C or less, 50 It may be carried out at a temperature of 60 ° C or more or 60 ° C or more and 80 ° C or less, and the pre-curing is 1 minute or more and 1 hour or less, 1 minute or more and 50 minutes or less, 1 minute or more and 40 minutes or less, 1 minute or more 30 minutes minutes or less, 1 minute or more and 20 minutes or less, 1 minute or more and 10 minutes or less, 10 minutes or more and 1 hour or less, 20 minutes or more and 1 hour or less, 30 minutes or more and 1 hour or less, 40 minutes or more and 1 hour or less, or 50 minutes or more and 1 hour or less It may be performed for the following time. When the pre-curing temperature and time conditions in the above range are satisfied, the pre-curing coating layer may be formed to have properties suitable for molding.

According to an exemplary embodiment of the present invention, the pre-curing conditions may vary depending on the type of the photocurable composition. Accordingly, mechanical properties of the nanomold may vary.

According to an exemplary embodiment of the present invention, the thickness of the pre-cured coating layer may be 300 nm or more and 3 μm or less. Specifically, the thickness of the pre-cured coating layer is 300 nm or more and 3 μm or less, 500 nm or more and 3 μm or less, 700 nm or more and 3 μm or less, 900 nm or more and 3 μm or less, 1 μm or more and 3 μm or less, 2 μm or more and 3 μm or more It may be μm or less, 300 nm or more and 2 μm or less, 300 nm or more and 1 μm or less, 300 nm or more and 700 nm or less, or 300 nm or more and 500 nm or less. When the thickness of the coating layer within the aforementioned range is satisfied, formability during pattern transfer may be excellent, and physical properties such as mechanical strength of the nanomold may be excellent.

According to one embodiment of the present invention, the second transfer step of transferring the first transferred pattern of the soft mold to the pre-cured coating layer; may be performed by photo lithography, imprinting lithography, or a combination thereof. . When the first transfer step is performed by the above-described method, the pre-cured coating layer may have a pattern representing a structural color formed on the soft mold and a plurality of nanostructures in reverse phase. Specifically, by the first transfer step, a pattern including a plurality of nanostructures forming a reverse image of the pattern of the master mold is formed on the soft mold, and by the second transfer step, the soft mold is formed on the pre-cured coating layer. By forming a pattern including a plurality of nanostructures forming a reverse image of the pattern of, the structural color may be implemented on the pre-cured coating layer that has passed through the second transfer step.

According to an exemplary embodiment of the present invention, the second transfer step; additionally curing the pre-cured coating layer; may further include. Specifically, the additional curing may be light curing. More specifically, the soft mold may perform a role similar to that of a mask during the additional curing. More specifically, the additional curing is to irradiate UV light for a certain period of time by installing UV lighting on the transparent soft mold after the second transfer step of transferring the pattern of the first transferred soft mold to the pre-cured coating layer. can More specifically, the additional curing may be additionally curing the pre-cured coating layer by irradiating UV light for a certain period of time in order to adjust the physical properties of the additionally cured coating layer to be suitable for forming a pattern including a plurality of nanostructures. . The soft mold may be separated from the substrate after the additional curing is completed.

According to an exemplary embodiment of the present invention, the additional curing may be performed by irradiating UV with a light amount of 500 mJ/cm ² or more and 3000 mJ/cm ² or less for a time of 1 minute or more and 1 hour or less. Specifically, the additional curing is 500 mJ/cm ² or more and 3000 mJ/cm ^{2 or} less, 500 mJ/cm ² or more and 2500 mJ/cm ^{2 or} less, 500 mJ/cm ^{2 or} more and 2000 mJ/cm ² or less, 500 mJ /cm ² or more and 1500 mJ/cm ² or less, 500 mJ/cm ² or more and 1000 mJ/cm ² or less, 1000 mJ/cm ² or more and 3000 mJ/cm ² or less, 1500 mJ/cm ² or more and 2000 mJ/cm ² or less, 2500 mJ/cm ² or more and 3000 mJ/cm ² or less or 1000 mJ/cm ^{2 or} more and 2000 mJ/cm ² or less may be performed by irradiating UV light, and the additional curing is 1 minute or more and 1 hour or less, 1 minute to 50 minutes, 1 minute to 40 minutes, 1 minute to 30 minutes, 1 minute to 20 minutes, 1 minute to 10 minutes, 10 minutes to 1 hour, 20 minutes to 1 hour, 30 It may be performed by irradiating UV for a time of 1 minute or more and 1 hour or less, 40 minutes or more and 1 hour or less, or 50 minutes or more and 1 hour or less. When the conditions for the amount of additional curing light and time within the above-described range are satisfied, the additional curing coating layer may be formed to have physical properties suitable for forming a pattern including a plurality of nanostructures.

According to an exemplary embodiment of the present invention, the additional curing conditions may vary depending on the type of the photocurable composition. Accordingly, mechanical properties of the nanomold may vary.

According to an exemplary embodiment of the present invention, the additional hard coating layer may have a thickness of 300 nm or more and 3 μm or less. Specifically, the thickness of the additional cured coating layer is 300 nm or more and 3 μm or less, 500 nm or more and 3 μm or less, 700 nm or more and 3 μm or less, 900 nm or more and 3 μm or less, 1 μm or more and 3 μm or less, 2 μm or more and 3 μm or more. It may be μm or less, 300 nm or more and 2 μm or less, 300 nm or more and 1 μm or less, 300 nm or more and 700 nm or less, or 300 nm or more and 500 nm or less. When the thickness of the coating layer within the aforementioned range is satisfied, formability during pattern transfer may be excellent, and physical properties such as mechanical strength of the nanomold may be excellent.

According to an exemplary embodiment of the present invention, the second transfer step may further include forming a structural color-based image or text by shielding a partial region of the first transferred soft mold pattern. Specifically, the shielding of the partial area may be performed on the third area excluding the first area and the second area to form an image or text having a pattern based on the structural color. More specifically, a first region in which a plurality of first nanostructures exhibiting the structural color are formed and a second region in which a plurality of second nanostructures different from the first nanostructure are formed may each have a structural color, and the shielding color may be displayed. Through this, the third region not including the plurality of nanostructures may have no structural color.

According to an exemplary embodiment of the present invention, the second transfer step; is formed by using a master mold on which a pattern including a plurality of nanostructures of a single type is formed, and a soft pattern including a plurality of nanostructures in reverse phase thereon. The structural color-based image may be selectively transferred onto the finally manufactured nano-mold by duplicating the mold and shielding the third region on the soft mold to form an image based on the structural color. In the case of forming a structural color-based image or text by shielding a portion of the master mold having a structural color pattern, expensive master molds are required for each image, which is not cost-effective. In contrast, in the case of forming structural color-based images or characters by shielding the third region on the soft mold having the structural color patterns, various structural color-based images or characters can be easily formed in a final product at a lower cost. there is.

According to one embodiment of the present invention, the shielding may be performed by printing a predetermined material on the third region to block the structural color on the soft mold. The shielding of the third region may serve as a masking function in the second transfer step and the product molding step so that the nanostructure is formed only in a portion where structural color development is required.

According to one embodiment of the present invention, the shielding may be performed by a printing method using the same material or a different material from the soft mold. Specifically, when the soft mold is a PDMS material, shielding may be performed using PDMS, and when the soft mold is a photocurable resin material, shielding may be performed using a photocurable resin. Preferably, the shielding is performed using the same material as the soft mold, but the shielding may be performed using a material different from that of the soft mold depending on the printing method of the shielding material. When the shielding is performed using the above-described material, adhesion between the soft mold and the shielding material may be improved.

According to one embodiment of the present invention, the printing method may include at least one of an inkjet method for discharging low-viscosity droplets, other flexography, offset printing, or pad printing. If the printing method is of the above-mentioned type, the shielding may be suitable for realizing a predetermined resolution.

The printing method may have a resolution of 150 dpi or higher. When the printing method has a resolution within the aforementioned range, it is possible to implement a clear structural color image suitable for commercial use.

According to one embodiment of the present invention, the post-curing may be thermal curing. Specifically, the post-curing may be curing by heating the additional cured coating layer at a predetermined temperature for a predetermined time in order to adjust physical properties of the additional cured coating layer to be suitable for product molding.

According to an exemplary embodiment of the present invention, the post-curing may be performed at a temperature of 100° C. or more and 200° C. or less for a time of 1 minute or more and 1 hour or less. Specifically, the post-curing is 100 ° C or more and 200 ° C or less, 120 ° C or more and 200 ° C or less, 140 ° C or more and 200 ° C or less, 160 ° C or more and 200 ° C or less, 180 ° C or more and 200 ° C or less, 100 ° C or more and 180 ° C or less, 100 It may be carried out at a temperature of 160 ° C or more, 100 ° C or more and 140 ° C or less, 120 ° C or more and 180 ° C or less, or 140 ° C or more and 160 ° C or less, and the post-curing is 1 minute or more and 1 hour or less, 1 minute or more 50 minute or less, 1 minute or more and 40 minutes or less, 1 minute or more and 30 minutes or less, 1 minute or more and 20 minutes or less, 1 minute or more and 10 minutes or less, 10 minutes or more and 1 hour or less, 20 minutes or more and 1 hour or less, 30 minutes or more 1 hour Or less, it may be performed for a time of 40 minutes or more and 1 hour or less, or 50 minutes or more and 1 hour or less. When the post-curing temperature and time conditions in the above-described range are satisfied, the coating layer may be formed to have properties suitable for forming a product.

According to an exemplary embodiment of the present invention, the post-curing conditions may vary depending on the type of the photocurable composition. Accordingly, mechanical properties of the nanomold may vary.

According to an exemplary embodiment of the present invention, the thickness of the post-curing coating layer may be 300 nm or more and 3 μm or less. Specifically, the thickness of the post-curing coating layer is 300 nm or more and 3 μm or less, 500 nm or more and 3 μm or less, 700 nm or more and 3 μm or less, 900 nm or more and 3 μm or less, 1 μm or more and 3 μm or less, 2 μm or more and 3 μm or more. It may be μm or less, 300 nm or more and 2 μm or less, 300 nm or more and 1 μm or less, 300 nm or more and 700 nm or less, or 300 nm or more and 500 nm or less. When the thickness of the coating layer within the aforementioned range is satisfied, formability during pattern transfer may be excellent, and physical properties such as mechanical strength of the nanomold may be excellent.

An exemplary embodiment of the present invention provides a nanomold manufactured by the method for manufacturing a nanomold described above. The nanomold manufactured by the nanomold manufacturing method according to the present invention may have excellent physical properties such as mechanical strength.

According to an exemplary embodiment of the present invention, the hardness of the nanomold may be 10 MPa or more. The nanomold may have a hardness of 10 MPa or more and 500 MPa or less. Specifically, the hardness of the nanomold is 10 MPa or more, 20 MPa or more, 40 MPa or more, 60 MPa or more, 80 MPa or more, 100 MPa or more, 120 MPa or more, 140 MPa or more, 160 MPa or more, 180 MPa or more, or 200 MPa or more, and the hardness of the nanomold may be 500 MPa or less, 450 MPa or less, 400 MPa or less, 350 MPa or less, 300 MPa or less, or 250 MPa or less. When the hardness of the nanomold satisfies the aforementioned range, physical properties such as mechanical strength of the nanomold may be excellent and may be suitable for product molding.

According to an exemplary embodiment of the present invention, the elastic modulus of the nanomold may be 1 GPa or more. Specifically, the elastic modulus of the nanomold may be 1 GPa or more and 15 GPa or less. Specifically, the elastic modulus of the nanomold may be 1 GPa or more, 2 GPa or more, 4 GPa or more, 6 GPa or more, 8 GPa or more, 10 GPa or more, or 12 GPa or more, and the elastic modulus of the nano mold may be 15 GPa or more. Or less, it may be 14 GPa or less, 12 GPa or less, or 10 GPa or less. When the elastic modulus of the nanomold satisfies the above range, the nanomold may have excellent physical properties such as mechanical strength, and may be suitable for product molding.

One embodiment of the present invention provides a method of manufacturing a product or film on which a structural color-based image is formed using the nanomold. A method for manufacturing a product or film having a structured color-based image according to an exemplary embodiment of the present invention can implement a clear structured color image or text suitable for commercial use.

An exemplary embodiment of the present invention provides a product or film on which a structural color-based image is formed using the nanomold. A product or film on which a structural color-based image is formed according to an exemplary embodiment of the present invention may implement a clear structural color image or text suitable for commercial use.

Hereinafter, a preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic diagram of a method for manufacturing a nanomold according to the present invention.

2 schematically shows a composition of a photocurable coating solution used in the method for manufacturing a nanomold according to the present invention and a process of forming a coating layer using the photocurable coating solution. Specifically, (a) of FIG. 2 schematically shows the composition of the photocurable coating solution used in the method for manufacturing a nanomold according to the present invention, and (b) of FIG. 2 shows formation of a coating layer using the photocurable coating solution. It schematically represents the process.

Referring to FIG. 1 (a) and FIG. 2 (a), first, a photocurable composition including an acrylic compound and a photopolymerization initiator and a photocurable coating solution including a solvent in which nanoparticles are dispersed may be prepared.

Referring to (b) of FIG. 1, a master mold 10 having a pattern including a plurality of nanostructures is prepared, and the pattern of the master mold 10 is transferred to a soft mold through a first transfer step to form a plurality of nanostructures. It is possible to manufacture a soft mold 20 having a pattern including nanostructures of.

Referring to (c) to (e) of FIG. 1 and (b) of FIG. 2, thereafter, a photocurable coating solution is applied on a substrate 40 to form a coating layer 30, and pre-curing (thermal curing) Thus, a pre-cured coating layer may be formed. Thereafter, through a second transfer step, the pattern of the soft mold 20 on which the pattern including the plurality of nanostructures is formed through the first transfer is transferred to the pre-cured coating layer, and further cured (photocured) by irradiating UV. ) to form an additional cured coating layer. Thereafter, the additional cured coating layer is post-cured (heat-cured) to form a patterned coating layer 50 including a plurality of nanostructures on the substrate 40 to manufacture the nanomold 100 according to the present invention. can

3 and 4 schematically show implementation examples of structural color-based images and text implemented on nanomolds according to the present invention.

5 schematically illustrates an embodiment of manufacturing a product having a structural color-based image using a nanomold according to the present invention.

Referring to FIGS. 5(a), 3 to 5(b), and 8(a), a master mold 10 having a pattern including a plurality of nanostructures is prepared, and a first transfer is performed. Through the steps, the pattern of the master mold 10 may be transferred to the soft mold to manufacture and prepare a soft mold 20 having a pattern including a plurality of nanostructures.

Thereafter, the soft mold 20 on which the pattern including the plurality of nanostructures is formed may further include forming a structural color-based image or text by shielding a partial area of the pattern of the first transferred soft mold. , Through this, it is possible to form a soft mold 20' on which a structural color-based image or text is formed. According to the shielding, a first region 21 including a plurality of first nanostructures and a second region including a plurality of second nanostructures ( 22) and a third region 23 not including nanostructures may be formed.

Referring to (c) to (e) of FIG. 3 and (c) to (d) of FIG. 5, as described above, a photocurable coating solution is applied on the substrate 40 to form a coating layer 30, , it is possible to form a pre-cured coating layer by pre-curing (thermal curing). Thereafter, through a second transfer step, the pattern of the soft mold 20' on which the structural color-based image or character is formed is transferred to the pre-cured coating layer, and further cured (photo-cured) by irradiating UV to obtain an additional cured coating layer. can form Thereafter, the additional cured coating layer is post-cured (heat-cured) to form a coating layer 50' on which a structural color-based image or character is formed on the substrate 40, thereby manufacturing the nanomold 100 according to the present invention. there is.

Referring to (e) of FIG. 5 , a film 60 ′ or structure in which structural color-based images or characters are formed by molding a film or product itself made of a thermoplastic resin using the nanomold 100 according to the present invention. A product 200 on which color-based images or characters are formed may be manufactured.

Hereinafter, examples will be described in detail to explain the present invention in detail. However, embodiments according to the present invention can be modified in many different forms, and the scope of the present invention is not construed as being limited to the embodiments described below. The embodiments herein are provided to more completely explain the present invention to those skilled in the art.

Example

Example 1

A master mold having a pattern including a first region in which nanodimples having a pitch of 3um, a diameter of 800 nm, and a height of 500 nm are embossedly formed, and a second region in which nanodimples having a pitch of 400 nm, a diameter of 180 nm, and a height of 100 nm are embossed are prepared. Thereafter, the pattern formed on the master mold was transferred onto a soft mold made of polydimethylsiloxane (PDMS) by an imprinting lithography method to manufacture a soft mold in which a pattern corresponding to the pattern on the master mold was formed in an intaglio.

Thereafter, the non-image area (third area) on the soft mold having the pattern representing the structural color formed thereon is shielded using a UV flatbed printer (DMP 3060N, DMP Co., Ltd.) to form an image based on the structural color. An image based on the structural color was formed on the soft mold by forming a pattern showing the structural color only in partial regions (first region and second region) of the mold.

As a photocurable coating solution, it was prepared by mixing PGMEA (Propylene glycol methyl ether acetate, Sigma-Aldrich Co., Ltd.) solvent in which ZrO ₂ nanoparticles were evenly dispersed, and Ormostamp (Microresist Co., Ltd.) as a photocurable composition. At this time, the diameter of the nanoparticles dispersed in the solvent is about 25 nm, the content of ZrO ₂ is 36.7 parts by weight based on 100 parts by weight of the solvent in which the nanoparticles are dispersed, and the weight ratio between the solvent in which the ZrO ₂ nanoparticles are dispersed and Ormostamp was adjusted to 2:1.

A 40 X 40 mm ² substrate made of stainless steel was prepared, the photocurable coating solution was spin-coated on the substrate at 1000 rpm for 30 seconds, and heated at 80 ° C. for 2 minutes to be suitable for molding for pattern transfer. A pre-cured coating layer was formed.

Thereafter, by soft imprinting using a soft mold having the intaglio pattern, the pre-cured coating layer formed on the substrate is molded so that an embossed pattern corresponding to the intaglio pattern is formed, and UV is irradiated with a light amount of 1000 mJ/cm ² (UV ramp B 100sp, Analytikjena Co.) and further cured.

Thereafter, in order to have hardness and durability suitable for thermoplastic resin molding, a post-cured nanomold was prepared by heating at 160° C. for 20 minutes.

Example 2

As a photocurable coating solution, a nanomold was prepared in the same manner as in Example 1, except that the weight ratio of the solvent in which the ZrO ₂ nanoparticles were dispersed and Ormostamp was adjusted to 3:1.

Example 3

As a photocurable coating solution, a nanomold was prepared in the same manner as in Example 1, except that the weight ratio of the solvent in which the ZrO ₂ nanoparticles were dispersed and Ormostamp was adjusted to 4:1.

Example 4

As a photocurable coating solution, a nanomold was prepared in the same manner as in Example 1, except that the weight ratio of the solvent in which the ZrO ₂ nanoparticles were dispersed and Ormostamp was adjusted to 6:1.

Example 5

As a photocurable coating solution, a nanomold was prepared in the same manner as in Example 1, except that the weight ratio of the solvent in which the ZrO ₂ nanoparticles were dispersed and Ormostamp was adjusted to 7:1.

Example 6

As a photocurable coating solution, a nanomold was prepared in the same manner as in Example 1, except that the weight ratio of the solvent in which the ZrO ₂ nanoparticles were dispersed and Ormostamp was adjusted to 15:1.

Example 7

Nano mold in the same manner as in Example 1, except that a convex cylindrical substrate manufactured by 3D printing (Form2, Formlabs) using a High Temp Resin material was prepared, and the pre-cured coating layer was formed on the substrate. was manufactured.

Example 8

A nanomold was manufactured in the same manner as in Example 1, except that a concave cylindrical substrate made of beryllium was prepared and the pre-cured coating layer was formed on the substrate.

Example 9

A nano-mold was manufactured in the same manner as in Example 1, except that a substrate made of a polyimide film was prepared and the pre-cured coating layer was formed on the substrate.

Comparative Example 1

A nanomold was prepared in the same manner as in Example 1, except that only Ormostamp was used as the photocurable coating solution.

Comparative Example 2

As a photocurable coating solution, a nanomold was prepared in the same manner as in Example 1, except that the weight ratio of the solvent in which the ZrO ₂ nanoparticles were dispersed and Ormostamp was adjusted to 1:1.

Experimental example

Evaluation of coating and nanopattern transfer

Photocurable coating solutions according to Comparative Example 1, Comparative Example 2, and Examples 1 to 6 were prepared. Thereafter, the photocurable coating solution was spin-coated on a 20 X 20 mm ² Glass substrate at 1000 rpm and 30 sec, and pre-cured to evaporate all solvents, and then the thickness of the coating layer was measured. At this time, pre-curing was performed by heating at 80 °C for 2 minutes.

In addition, the nanoparticle content was measured through component analysis of the solvent-evaporated residue after pre-curing. At this time, the nanoparticle content was expressed based on 100 parts by weight of the photocurable composition and the total volume of the photocurable composition.

A nano-mold prepared by transferring a pattern using a soft mold on which a pattern is formed on the pre-cured coating layer, additionally curing through UV irradiation under a condition of 1000 mJ/cm ² and post-curing through heating at 160 ° C. for 20 minutes Nanopattern transfer was evaluated for . At this time, the nanopattern transfer evaluation result was indicated as 'O' when the structural color was expressed and 'X' when the structural color was not expressed based on whether or not the structural color was expressed on the manufactured nanomold.

The thickness, nanoparticle content, and nanopattern transfer results according to the above evaluation are shown in Table 1 below.

Sample Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 nanoparticle content wt % 0 26.8 42.3 52.4 59.5 68.8 72.0 84.6 Vol% 0 7.2 13.4 18.9 23.6 31.8 35.2 53.8 Coating thickness (μm) 40.29 7.2 4.6 3.3 2.62 2.11 1.99 1.45 Pattern transcription evaluation O O O O O O O O

In order to confirm the change in the thickness of the coating layer according to the change in the nanoparticle content of the photocurable coating solution, the nanoparticle content was adjusted to 0% to 60% by volume based on the total volume of the photocurable composition, except that A coating layer was formed in the same manner as in Example 1, and the results of measuring the thickness are shown in FIG. 6 below. At this time, the nanoparticle content is shown based on 100 parts by weight of the photocurable composition.

6 shows the thickness of the coating layer according to the change in the nanoparticle content of the nanomold according to the present invention.

Referring to Table 1 and FIG. 6, as the added amount of the nanoparticle dispersion solvent increases, the viscosity of the photocurable coating solution decreases, so the coating thickness decreases, but it is confirmed that there is no effect on pattern transfer by nanoimprinting. Through this, even when nanoparticles are mixed in a predetermined ratio to improve the mechanical strength of the photocurable composition, the nanomold produced by the method of manufacturing the nanomold according to the present invention is a nanostructure necessary for forming a coating layer and realizing a structural color image. It can be seen that the formation is good.

In order to confirm pattern transfer when substrates of various materials and shapes are used, pattern transfer evaluation is performed on the nano-molds according to Examples 1 and 7 to 9 in the same manner as the pattern transfer evaluation. It is shown in Figures 7 and 8 below.

7 is a photograph showing structural color-based images implemented on nanomolds according to Examples 1 and 7 to 9; Specifically, (a) of FIG. 7 is a photograph showing an image based on the structural color implemented on the nanomold according to Example 1, and (b) of FIG. 7 is a photograph showing the structural color implemented on the nanomold according to Example 7. 7(c) is a photograph showing the structural color-based image implemented on the nanomold according to Example 8, and FIG. 7(d) is a photograph showing the nanomold according to Example 9. This is a picture showing the implemented structural color-based image.

8 is a photograph showing structural color-based characters implemented on a nanomold according to Example 1; Specifically, FIG. 8(a) is a photograph showing structural color-based characters implemented on a soft mold for transferring a pattern to a nanomold according to Example 1, and FIG. 8(b) shows a photograph according to Example 1 This is a picture showing the structural color-based letters implemented on the nano mold.

7 and 8, in the case of the nano-molds of Examples 7 to 9 using materials other than the nano-mold of Example 1 using the stainless steel substrate, the nano-patterns formed on the substrate through coating and imprinting As a result, it was confirmed that the expression of the structural color was good. From this, it can be seen that the nanomold according to the present invention can form a structural color-based image using substrates of various materials and shapes.

Transfer durability evaluation

As a molding material, a 1 mm thick film made of PMMA (Poly(methyl methacrylate)) was prepared.

After transferring the PMMA film 30 times by hot embossing using the nano-mold according to Comparative Example 1 and Example 1, the first area and the second area where embossed patterns on the nano-mold are formed are formed. SEM (10,000x, NanSEM 200, Nova Co.) images for were taken and shown in FIGS. 9 and 10 below. Thereafter, the shape change of the nanostructures in each region before and after transfer was evaluated.

At this time, the temperature of the nano-mold was adjusted to 140 °C, the contact pressure between the PMMA film and the nano-mold was 7.1 MPa, and the pressing time was adjusted to 10 minutes.

9 shows a SEM image of a nanopattern formed on a nanomold according to Comparative Example 1. Specifically, FIG. 9(a) is an SEM image of the first region formed on the nanomold according to Comparative Example 1, and FIG. 9(b) is a SEM image of the first region formed on the nanomold according to Comparative Example 1. 9(c) is an SEM image of a second area formed on the nanomold according to Comparative Example 1, and FIG. 9(d) is an SEM image of the nanomold according to Comparative Example 1. It is an SEM image of the formed second region after one-time thermoplastic resin molding.

10 shows a SEM image of a nanopattern formed on a nanomold according to Example 1. Specifically, FIG. 10(a) is an SEM image of the first region formed on the nanomold according to Example 1, and FIG. 10(b) is a 30-degree view of the first region formed on the nanomold according to Example 1. 10(c) is an SEM image of a second area formed on the nanomold according to Example 1, and FIG. 10(d) is an SEM image of the nanomold according to Example 1. This is a SEM image of the formed second region after 30 times of thermoplastic resin molding.

Referring to FIGS. 9 and 10 , it was confirmed that the nano-mold according to Comparative Example 1 prepared using only the photocurable composition was destroyed and fell off during the first molding process during molding of the thermoplastic resin. On the other hand, in the nanomold according to Example 1 prepared using the photocurable composition and the photocurable coating solution containing the nanoparticle-dispersed solvent, when the nanomold is molded under the same conditions, the nanostructure after the initial and 30th molding is formed. It was confirmed that there was little change. From this, it can be seen that the nanomold manufactured by the method for manufacturing a nanomold according to the present invention has excellent durability under heating and pressurization conditions and is suitable for repeated molding of a photocurable resin.

Evaluation of mechanical properties

In order to determine the increase in mechanical properties of the nanomold as the nanoparticle content increases, nanomold specimens according to Comparative Example 1, Comparative Example 2, Example 1, Example 3, Example 5, and Example 6 were prepared and nano Hardness and modulus of elasticity were measured through a nanoindentation method and are shown in FIGS. 11 and 12 below.

11 shows the elastic modulus according to the change in nanoparticle content of nanomolds according to Comparative Example 1, Comparative Example 2, Example 1, Example 3, Example 5, and Example 6.

12 shows the hardness according to the change in nanoparticle content of the nanomolds according to Comparative Example 1, Comparative Example 2, Example 1, Example 3, Example 5, and Example 6.

11 and 12, as a result of measuring the elastic modulus and hardness for 10 points, the elastic modulus of Comparative Example 1 using a pure photocurable resin ormostamp was 75 ± 2 MPa and the hardness was measured to be 9.7 ± 0.16 MPa. . From Example 1 showing the nanoparticle content of 42.3 parts by weight, it was confirmed that the elastic modulus and hardness began to increase distinctly as the nanoparticle content increased, and then increased exponentially with increasing content. In the case of Example 6 in which the nanoparticle content was 84.6 parts by weight under experimental conditions, the elastic modulus was 11.9 ± 0.25 GPa, which was 158 times higher than that of Comparative Example 1, and the hardness was 146.9 ± 0.1 MPa, which was 15.1 times higher. From this, it can be seen that the nanomold manufactured by the nanomold manufacturing method according to the present invention has excellent mechanical properties required for use as a resin molding mold, such as elastic modulus and hardness.

The foregoing detailed description is intended to illustrate and explain the present invention. In addition, the foregoing merely represents and describes preferred embodiments of the present invention, and as described above, the present invention can be used in various other combinations, modifications, and environments, and the scope of the inventive concept disclosed herein, the foregoing Changes or modifications are possible within the scope equivalent to the disclosure and / or within the scope of skill or knowledge in the art. Accordingly, the above detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed to cover other embodiments as well.

100: nano mold
10: master mold on which a pattern including a plurality of nanostructures is formed
20: soft mold having a pattern including a plurality of nanostructures
20': Soft mold on which structural color-based images or characters are formed
21: first region including a plurality of first nanostructures
22: second region including a plurality of second nanostructures
23: third region not containing nanostructures
30: coating layer
40: base
50: a patterned coating layer including a plurality of nanostructures
50': coating layer on which structural color-based images or characters are formed
60': film on which structural color-based images or characters are formed
200: Products on which structural color-based images or characters are formed

Claims (13)

preparing a master mold on which a pattern including a plurality of nanostructures is formed;
a first transfer step of transferring the pattern of the master mold to a soft mold;
Applying a photocurable coating solution on a substrate and pre-curing to form a pre-cured coating layer;
a second transfer step of transferring the first transferred pattern of the soft mold to the pre-cured coating layer; and
Preparing a nanomold by post-curing the pre-cured coating layer; Including,
The second transfer step further includes further curing the pre-cured coating layer,
The pre-curing is performed by thermal curing, and the additional curing is performed by photo-curing,
The method of manufacturing a nanomold, wherein the pattern including the plurality of nanostructures exhibits a structural color.
According to claim 1,
Wherein the pattern including the plurality of nanostructures includes a first region in which a plurality of first nanostructures exhibiting structural colors are formed and a second region in which a plurality of second nanostructures different from the first nanostructures are formed. A method of making molds.
According to claim 1,
The first transfer step; the method of manufacturing a nano-mold further comprising a step of surface treating the soft mold.
According to claim 1,
The method of manufacturing a nano-mold in which the substrate is formed in a curved surface.
According to claim 1,
Wherein the photocurable coating solution includes a photocurable composition including an acrylic compound and a photopolymerization initiator and a solvent in which nanoparticles are dispersed.
According to claim 5,
The method of manufacturing a nanomold, wherein the nanoparticles have a diameter of 5 nm or more and 30 nm or less.
According to claim 5,
The method of manufacturing a nanomold wherein the content of the nanoparticles is 10 vol% or more and 60 vol% or less based on the total volume of the photocurable composition.
According to claim 5,
Wherein the nanoparticles include at least one of ZrO ₂ , TiO ₂ , Al ₂ O ₃ and SiO ₂ .
delete According to claim 1,
The second transfer step further includes forming a structural color-based image or text by shielding a partial region of the pattern of the first transferred soft mold.
A nano-mold prepared by the method according to claim 1 .
According to claim 11,
The nanomold having a hardness of 10 MPa or more.
According to claim 11,
The nanomold having an elastic modulus of 1 GPa or more.

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