Method for manufacturing a resin film and metal mold

Abstract

The present application is a method for manufacturing a resin film having a roughened shape on at least a part of the surface of the resin film, the method comprising a transfer step of transferring the roughened shape possessed by a roughened surface of a metal mold to the resin film by contacting the metal mold having the roughened surface on at least a part of the surface with the resin film, the roughened surface of the metal mold having a developed area ratio (Sdr) of 0.094 to 0.4285 and a root mean square slope (Sdq) of 0.14 to 0.99 according to ISO 25178.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a resin film and a metal mold. Background Technology

[0002] Resin films require various properties depending on their application. For example, resin films with high water repellency or high hydrophilicity have multiple uses. In addition, in recent years, to prevent infection with COVID-19 (the so-called novel coronavirus infectious disease) or seasonal influenza, resin films that come into contact with human hands are sometimes required to have antiviral properties on their surface.

[0003] Patent Document 1 describes an antiviral surface treatment method that randomly forms a large number of tiny bumps and depressions with specific widths of the bump-depression spacing and the width of the depression depth by subjecting the surface of a component to a shot peening treatment (hereinafter also referred to as "shot peening treatment"), thereby giving the surface of the component an antiviral effect.

[0004] Prior technology documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2022-28394 Summary of the Invention

[0005] [The problem the invention aims to solve] As a benchmark for evaluating antiviral activity, there is an "antiviral activity value." In the technology described in Patent Document 1, the comparison object (stainless steel sheet) did not show antiviral activity, but when the antiviral surface treatment method was applied, the antiviral activity value was 0.4 to 0.7 after 24 hours at 25°C. However, the inventors conducted research and determined that because the shot peening process involves projecting shot peening material onto the surface of the component, it can only impart a convex shape towards the back of the component. Therefore, the antiviral activity obtained using the technology described in Patent Document 1 is insufficient, and further improvement in antiviral activity is needed.

[0006] Furthermore, Patent Document 1 neither describes nor implies the imparting of water-repellent or hydrophilic properties to the resin film.

[0007] In view of the foregoing, the object of the present invention is to provide a method for manufacturing a resin film, which, by roughening at least a portion of the surface of the resin film, imparts hydrophobicity, hydrophilicity, and / or antiviral properties to the resin film. Furthermore, the object of the present invention is to provide a metal mold for forming a roughened shape on at least a portion of the surface of the resin film, which, by roughening at least a portion of the surface of the resin film, imparts hydrophobicity, hydrophilicity, and / or antiviral properties to the resin film.

[0008] [Problem-solving methods] The problem can be solved by the following configuration. The present invention relates to a method for manufacturing a resin film (1), characterized in that: at least a portion of the surface of the resin film has a roughened shape, the method for manufacturing the resin film includes a transfer step, wherein the transfer step transfers the roughened shape of the roughened surface to the resin film by contacting a metal mold having at least a portion of its surface with the roughened surface, wherein the roughened surface of the metal mold has an unfolded area ratio (Sdr) of 0.005 to 0.5 as measured according to ISO25178, and a root mean square slope (Sdq) of 0.1 to 1.5.

[0009] A preferred method for manufacturing a resin film (2) wherein, in the method for manufacturing a resin film (1), at least a portion of the surface of the resin film is given water-repellent properties during the transfer process.

[0010] The preferred method for manufacturing the resin film (3) is that, in the method for manufacturing the resin film (2), the contact angle between the resin film and water before the transfer process is 90° or more.

[0011] A preferred method for manufacturing a resin film (4) wherein, in the method for manufacturing a resin film (1), at least a portion of the surface of the resin film is made hydrophilic during the transfer process.

[0012] A preferred method for manufacturing a resin film (5) wherein, in the method for manufacturing a resin film (4), the contact angle between the resin film and water before the transfer process is 90° or less.

[0013] A preferred method for manufacturing a resin film (6) wherein, in the method for manufacturing a resin film (1), at least a portion of the surface of the resin film is endowed with antiviral properties during the transfer process.

[0014] In addition, the present invention relates to a metal mold (7), characterized in that: the metal mold is used to form a roughened shape on at least a portion of the surface of a resin film, the metal mold having a roughened surface on at least a portion of its surface for transferring the roughened shape to the resin film, the roughened surface having an unfolded area ratio (Sdr) of 0.005 to 0.5 as measured according to ISO25178, and a root mean square slope (Sdq) of 0.1 to 1.5.

[0015] [The effects of the invention] The method for manufacturing the resin film of the present invention includes a transfer step, wherein the transfer step involves contacting a metal mold having at least a portion of its surface roughened with the resin film, thereby transferring the roughened shape of the roughened surface to the resin film. Here, in the method for manufacturing the resin film of the present invention, the unfolded area ratio (Sdr) obtained by measuring the roughened surface of the metal mold according to ISO 25178 is designed to be 0.005 to 0.5, and the root mean square slope (Sdq) is 0.1 to 1.5. This allows the resin film to be endowed with hydrophobic, hydrophilic, and / or antiviral properties. Attached Figure Description

[0016] Figure 1 This is a scanning electron microscope image (1500x magnification) of a copper plate surface without roughening (untreated).

[0017] Figure 2 This is a scanning electron microscope image (5000x magnification) of a copper plate surface without roughening (untreated).

[0018] Figure 3 It is a scanning electron microscope image (1500x magnification) of the surface of a copper plate (metal mold A) with a roughened shape A.

[0019] Figure 4 It is a scanning electron microscope image (5000x magnification) of the surface of a copper plate (metal mold A) with a roughened shape A.

[0020] Figure 5 It is a scanning electron microscope image (1500x magnification) of the surface of a copper plate (metal mold B) with a roughened shape B.

[0021] Figure 6 It is a scanning electron microscope image (5000x magnification) of the surface of a copper plate (metal mold B) with a roughened shape B.

[0022] Figure 7 It is a scanning electron microscope image (1500x magnification) of the surface of a copper plate (metal casting C) with a roughened shape C.

[0023] Figure 8 It is a scanning electron microscope image (5000x magnification) of the surface of a copper plate (metal casting C) with a roughened shape C.

[0024] Figure 9 It is a scanning electron microscope image (1500x magnification) of the surface of a copper plate (metal mold D) with a roughened shape D.

[0025] Figure 10 It is a scanning electron microscope image (5000x magnification) of the surface of a copper plate (metal casting D) with a roughened shape D.

[0026] Figure 11 This is a scanning electron microscope image (1500x magnification) of the surface of a resin film (PP film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape A. Figure 12 This is a scanning electron microscope image (5000x magnification) of the surface of a resin film (PP film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape A. Figure 13 This is a scanning electron microscope image (1500x magnification) of the surface of a resin film (PP film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape B. Figure 14 This is a scanning electron microscope image (5000x magnification) of the surface of a resin film (PP film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape B. Figure 15 This is a scanning electron microscope image (1500x magnification) of the surface of a resin film (PP film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape C. Figure 16 This is a scanning electron microscope image (5000x magnification) of the surface of a resin film (PP film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape C. Figure 17 This is a scanning electron microscope image (1500x magnification) of the surface of a resin film (PP film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape D. Figure 18 This is a scanning electron microscope image (5000x magnification) of the surface of a resin film (PP film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape D. Figure 19 This is a scanning electron microscope image (1500x magnification) of the surface of a resin film (Acryl film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape A. Figure 20 This is a scanning electron microscope image (5000x magnification) of the surface of a resin film (Acryl film) that has undergone a transfer process using a copper plate (metal mold A) with a roughened shape A. Figure 21 This is a scanning electron microscope image (1500x magnification) of the surface of a resin film (Acryl film) that underwent a transfer process using a copper plate (metal mold B) with a roughened shape B. Figure 22This is a scanning electron microscope image (5000x magnification) of the surface of a resin film (Acryl film) that underwent a transfer process using a copper plate (metal mold B) with a roughened shape B. Figure 23 This is a scanning electron microscope image (1500x magnification) of the surface of a resin film (Acryl film) that has undergone a transfer process using a copper plate (metal mold C) with a roughened shape C. Figure 24 This is a scanning electron microscope image (5000x magnification) of the surface of a resin film (Acryl film) that has undergone a transfer process using a copper plate (metal mold C) with a roughened shape C. Figure 25 This is a scanning electron microscope image (1500x magnification) of the surface of a resin film (Acryl film) that has undergone a transfer process using a copper plate (metal mold D) with a roughened shape D. Figure 26 This is a scanning electron microscope image (5000x magnification) of the surface of a resin film (Acryl film) that has undergone a transfer process using a copper plate (metal mold D) with a roughened shape D. Detailed Implementation

[0027] The method for manufacturing a resin film according to the present invention produces a resin film that exhibits hydrophobicity, hydrophilicity, and / or antiviral properties by having a roughened shape on at least a portion of its surface. The method for manufacturing a resin film according to the present invention includes a transfer step in which the roughened shape of the roughened surface is transferred to the resin film by contacting a metal mold having a roughened surface on at least a portion of its surface with the resin film. The roughened surface of the metal mold used in the transfer step has an unfolded area ratio (Sdr) of 0.005 to 0.5 as measured according to ISO 25178, and a root mean square slope (Sdq) of 0.1 to 1.5.

[0028] In the method for manufacturing the resin membrane of the present invention, various resin membranes can be used as raw materials to facilitate the imparting of desired hydrophobicity, hydrophilicity, and / or antiviral properties. For example, when imparting hydrophobicity to at least a portion of the surface of the resin membrane, it is preferable to use a resin membrane with a water contact angle of 90° or more as the raw material; examples of such resin membranes include polypropylene (PP) membranes. Conversely, when imparting hydrophilicity to at least a portion of the surface of the resin membrane, it is preferable to use a resin membrane with a water contact angle of 90° or less as the raw material; examples of such resin membranes include poly(meth)acrylic acid membranes.

[0029] Furthermore, when imparting antiviral properties to at least a portion of the surface of the resin film, examples of resin films that can be used as raw materials include thermoplastic resins, thermosetting resins, and UV-curable resins. Examples of thermoplastic resins include: general-purpose plastics such as polypropylene, polyacrylic acid resin, and ABS resin; engineering plastics such as 6 nylon, 66 nylon, polyacetal, polycarbonate, polybutylene terephthalate, and modified polyphenylene ether; and super engineering plastics such as polyphenylene ether, liquid crystal polymers, and polyetherimide. Examples of thermosetting resins include: phenolic resins, urea resins, melamine resins, epoxy resins, unsaturated polyester resins, polyurethane resins, diallyl phthalate resins, silicone resins, and alkyd resins. Examples of UV-curable resins include: acrylic resins and epoxy resins.

[0030] Next, the metal molds used in the transfer process will be explained.

[0031] The metal mold used in the transfer process of the resin film manufacturing method of the present invention has a roughened surface on at least a portion of its surface. The specific characteristics of the roughened surface will be described separately. Examples of metal components constituting the metal mold include: aluminum, aluminum alloys, copper, copper alloys, nickel, nickel alloys, stainless steel, titanium, titanium alloys, iron, or iron alloys. Among these, in the present invention, aluminum, aluminum alloys, copper, or copper alloys are preferred as metal components, and copper or copper alloys are more preferred. The shape or size of the metal mold can be appropriately designed according to the intended use of the resin film to impart water-repellent, hydrophilic, and / or antiviral properties.

[0032] As a process of forming a roughened surface on at least a portion or the entire surface of a metal mold, for example, a roughening process can be described by contacting a micro-etching agent with the surface of a metal part to form a roughened surface on the surface of the metal part.

[0033] As a micro-etching agent used in the roughening process, for example, organic acid-based micro-etching agents, inorganic acid-based micro-etching agents, alkaline micro-etching agents, or hydrogen peroxide-based micro-etching agents can be used.

[0034] Organic acid-based micro-etching agents include, for example, micro-etching agents composed of aqueous solutions containing organic acids, metal ion sources, halide ion sources, etc.

[0035] Examples of inorganic acid-based microetching agents include microetching agents composed of acidic aqueous solutions containing inorganic acids, metal ion sources, halide ion sources, etc.

[0036] Examples of alkaline micro-etching agents include those composed of aqueous solutions containing an alkaline source, amphoteric metal ion source, nitrate ions, sulfur compounds, etc.

[0037] Examples of hydrogen peroxide-based micro-etching agents include those composed of aqueous solutions of hydrogen peroxide and sulfuric acid as the main agents.

[0038] The roughening process can be performed in one step, but in order to improve the properties of the roughened surface of the manufactured metal mold, it is preferable to perform it in two steps, and more preferably in three steps: a pretreatment step, a formal treatment step, and a post-treatment step. The following describes an implementation of the roughening process in three steps.

[0039] The pretreatment step can be exemplified by the following steps: immersing the surface of the metal part to be treated in, for example, dilute nitric acid, a hydrogen peroxide-based soft etcher consisting of an aqueous solution with hydrogen peroxide and sulfuric acid as the main agents, or an alkaline soft etcher containing the aforementioned alkaline source, a zwitterionic source, nitrate ions, sulfur compounds, etc. The treatment temperature can be, for example, 15–40°C, and the treatment time can be, for example, approximately 3 seconds to 10 minutes.

[0040] The formal processing steps can be exemplified by the following steps: at least the surface of the metal component to be processed is immersed in the aforementioned organic acid-based micro-etching agent, inorganic acid-based micro-etching agent, alkaline micro-etching agent, or hydrogen peroxide-based micro-etching agent. For example, the processing temperature can be 10–40°C, and the processing time can be approximately 5 seconds to 10 minutes.

[0041] The post-treatment step can be exemplified by the following steps: at least immersing the treated surface of the metal part in, for example, dilute nitric acid. The treatment temperature can be, for example, 15–40°C, and the treatment time can be, for example, approximately 3–40 seconds.

[0042] After the roughening process, a roughened surface can be formed on the surface of the metal part, wherein the roughened surface has an unfolded area ratio (Sdr) of 0.005 to 0.5 as measured according to ISO 25178, and a root mean square slope (Sdq) of 0.1 to 1.5. The unfolded area ratio (Sdr) and root mean square slope (Sdq) of the roughened surface formed on the surface of the metal part can be adjusted by changing the type of micro-etchant in the roughening process and the processing time and / or temperature of the roughening process (one step, two steps, and / or three steps) to arbitrary conditions. In order to impart a higher level of water repellency, hydrophilicity, and / or antiviral properties to the resin film, it is more preferable that the roughened surface of the metal mold has an unfolded area ratio (Sdr) of 0.0094 to 0.4285 as measured according to ISO 25178, and a root mean square slope (Sdq) of 0.14 to 0.99.

[0043] Next, the transfer process of the resin film manufacturing method of the present invention will be described. The transfer process involves contacting a metal mold with at least a portion of its surface having a roughened surface with the resin, thereby transferring the roughened shape of the roughened surface to the resin film.

[0044] As a method for transferring the roughened shape of a roughened surface of a metal mold to a resin film by contacting the metal mold with the resin film, an example method is to overlap the roughened surface of the metal mold with the surface of the resin film to be subjected to water-repellent, hydrophilic, and / or antiviral treatments, and then perform hot pressing using a press. On the other hand, as a method for transferring the roughened shape of a roughened surface of a metal mold to the surface of a thermosetting resin or a UV-curable resin, an example method is to form a mold that includes at least the roughened surface of the metal mold, pour raw material components of a thermosetting resin or a UV-curable resin into it, cure it, and then demold the resin film, thereby transferring the roughened shape formed on the surface of the metal part to the surface of the thermosetting resin or the UV-curable resin.

[0045] After the transfer process, a complex roughened shape is formed on the surface of the resin film. Specific examples of the complex roughened shape formed on the surface of the resin part after the transfer process will be explained later.

[0046] The method for manufacturing the resin film of the present invention can impart water-repellent, hydrophilic, and / or antiviral properties to the resin film. In the present invention, the water-repellent property of the resin film is evaluated by its contact angle with water. Specifically, in the present invention, water-repellent property is considered to be imparted when the contact angle is 10° or more higher than that of the untreated resin film before the transfer process. In the present invention, the water-repellent property of the resin film is particularly excellent when a contact angle with water exceeds 110°, and is therefore preferred. Furthermore, in the present invention, the water-repellent property of the resin film is also evaluated by its contact angle with water. Water-repellent property is considered to be imparted when the contact angle is 10° or more lower than that of the untreated resin film before the transfer process. In the present invention, the hydrophilicity of the resin film is particularly excellent when a contact angle with water is 70° or less, and is therefore preferred.

[0047] Furthermore, the resin film manufacturing method of the present invention can produce a resin film with excellent antiviral properties. The antiviral activity value, which represents the degree of antiviral properties, can be obtained by referring to JIS R1756:2020 (Visible light responsive photocatalyst, antiviral, membrane close contact method) and calculated using the following formula.

[0048] V D =Log(B D ) - Log(C D (1) In the above formula (1), V DThe values ​​represent antiviral activity, D represents the dark, B represents the infectivity of unprocessed products, and C represents the infectivity of processed products.

[0049] As described above, the resin film manufacturing method of the present invention enables the production of resin films with excellent antiviral properties. Therefore, the resin film manufacturing method of the present invention can also be used as a method for imparting antiviral properties to resin films used in the following articles: household appliances, residential building materials / equipment, toilet-related facilities / supplies, kitchen-related facilities / supplies, bathroom-related facilities / supplies, business machinery / business supplies, printing (printed matter, laminated products, or paper), transportation machinery, industrial machinery / industrial supplies (films, packaging materials for food, etc., bundling materials, etc.), medical / nursing / health, communication-related / accessories, pet supplies, daily necessities (shoes, cleaning supplies, cosmetics, etc.), etc.

[0050] Example The following describes one example of an embodiment of the present invention, but the present invention is not limited by this description.

[0051] <Methods for determining the developed area ratio (Sdr) and root mean square slope (Sdq) of the roughened surface of a metal casting mold> The developed area ratio (Sdr) and root mean square slope (Sdq) of the roughened surface of a metal mold were measured using a confocal microscope (OPTELICS HYBRID+) manufactured by Lasertec, in accordance with ISO 25178. Furthermore, measurements were performed using an S-filter (0.0025 mm) and an L-filter (0.08 mm), with threshold values ​​set.

[0052] [Example of metal mold manufacturing (example of roughened surface formation)] First, prepare a copper plate without a roughened shape (unprocessed). Figure 1 A scanning electron microscope image (1500x magnification) of a copper plate surface without roughening (untreated) is shown. Figure 2 A scanning electron microscope image (5000x magnification) of the surface of an untreated copper plate without a roughened shape is shown. A metal mold A with a roughened surface having a roughened shape A on at least a portion of its surface, a metal mold B with a roughened surface having a roughened shape B on at least a portion of its surface, a metal mold C with a roughened surface having a roughened shape C on at least a portion of its surface, and a metal mold D with a roughened surface having a roughened shape D on at least a portion of its surface are manufactured by performing a roughening process on the untreated copper plate. Figure 3 A scanning electron microscope image (1500x magnification) of the surface of a copper plate (metal mold A) with a roughened shape A is shown. Figure 4A scanning electron microscope image (5000x magnification) of the surface of a copper plate (metal mold A) with a roughened shape A is shown. Figure 5 A scanning electron microscope image (1500x magnification) of the surface of a copper plate (metal mold B) with a roughened shape B is shown. Figure 6 A scanning electron microscope image (5000x magnification) of the surface of a copper plate (metal mold B) with a roughened shape B is shown. Figure 7 A scanning electron microscope image (1500x magnification) of the surface of a copper plate (metal mold C) with a roughened shape C is shown. Figure 8 A scanning electron microscope image (5000x magnification) of the surface of a copper plate (metal mold C) with a roughened shape C is shown. Figure 9 A scanning electron microscope image (1500x magnification) of the surface of a copper plate (metal mold D) with a roughened shape D is shown. Figure 10 A scanning electron microscope image (5000x magnification) of the surface of a copper plate (metal mold D) with a roughened shape D is shown. The following describes the roughening process performed on metal molds A, B, C, and D.

[0053] [Roughening process for metal casting mold A] The roughening process (pre-treatment step, formal treatment step, and post-treatment step) is performed on unused copper plates (100 mm × 100 mm × 1.3 mm) under the following conditions. The conditions for each step are shown below.

[0054] (Preprocessing steps) The surface of the copper plate to be treated was sprayed with a sulfuric acid / hydrogen peroxide-based soft etcher. Treatment temperature: 25°C. Treatment time: 20 seconds.

[0055] (Formal processing steps) Following pretreatment, the surface of the copper plate to be treated was sprayed with an inorganic acid-based micro-etching agent (a micro-etching agent composed of an aqueous solution containing inorganic acid, metal ion source, halide ion source, etc.). Treatment temperature: 30℃. Treatment time: 50 seconds.

[0056] (Post-processing steps) Following the formal treatment, the surface of the copper plate to be treated is sprayed with dilute hydrochloric acid. Treatment temperature: 25℃. Treatment time: 15 seconds.

[0057] Table 1 shows the ratio of the developed area (Sdr) and the root mean square slope (Sdq) of the roughened surface of the metal mold A obtained after the roughening process.

[0058] [Roughening process for metal mold B] The roughening process (pre-treatment step, formal treatment step, and post-treatment step) is performed on unused copper plates (100 mm × 100 mm × 1.3 mm) under the following conditions. The conditions for each step are shown below.

[0059] (Preprocessing steps) The surface of the copper plate to be treated was sprayed with a sulfuric acid / hydrogen peroxide-based soft etcher. Treatment temperature: 25°C. Treatment time: 20 seconds.

[0060] (Formal processing steps) Following pretreatment, the surface of the copper plate to be treated was sprayed with an inorganic acid-based micro-etching agent (a micro-etching agent composed of an aqueous solution containing inorganic acid, metal ion source, halide ion source, etc.). Treatment temperature: 30℃. Treatment time: 50 seconds.

[0061] (Post-processing steps) Following the formal treatment, the surface of the copper plate to be treated is sprayed with dilute hydrochloric acid. Treatment temperature: 25℃. Treatment time: 15 seconds.

[0062] Table 1 shows the developed area ratio (Sdr) and root mean square slope (Sdq) of the roughened surface of the metal mold B obtained after the roughening process.

[0063] [Roughening process for metal casting mold C] The roughening process (pre-treatment step, formal treatment step, and post-treatment step) is performed on unused copper plates (100 mm × 100 mm × 1.3 mm) under the following conditions. The conditions for each step are shown below.

[0064] (Formal processing steps) Following pretreatment, the surface of the copper plate to be treated was sprayed with a sulfuric acid / hydrogen peroxide-based micro-etching agent. Treatment temperature: 30℃. Treatment time: 50 seconds.

[0065] The developed area ratio (Sdr) and root mean square slope (Sdq) of the roughened surface of the metal mold C obtained after the roughening process are shown in Table 1.

[0066] [Roughening process for metal casting mold D] The roughening process (pre-treatment step, formal treatment step, and post-treatment step) is performed on unused copper plates (100 mm × 100 mm × 1.3 mm) under the following conditions. The conditions for each step are shown below.

[0067] (Preprocessing steps) The surface of the copper plate to be treated was sprayed with a soft etchant consisting of a sulfuric acid and hydrogen peroxide mixture. Treatment temperature: 25°C. Treatment time: 20 seconds.

[0068] (Formal processing steps) Following pretreatment, the surface of the copper plate to be treated was sprayed with an organic acid-based micro-etching agent (a micro-etching agent composed of an aqueous solution containing organic acids, metal ion sources, halide ion sources, etc.). Treatment temperature: 30℃. Treatment time: 50 seconds.

[0069] (Post-processing steps) Following the formal treatment, the surface of the copper plate to be treated is sprayed with dilute hydrochloric acid. Treatment temperature: 25℃. Treatment time: 15 seconds.

[0070] Table 1 shows the ratio of the developed area (Sdr) and the root mean square slope (Sdq) of the roughened surface of the metal mold D obtained after the roughening process.

[0071] [Table 1]

[0072] <Method for determining the contact angle between resin membrane and water> The contact angle between the resin membrane and water was measured under the following conditions.

[0073] Measuring instrument: Automatic contact angle meter (DM-501) manufactured by Kyowa Interface Science. Test conditions: The solvent used for testing is DI (water). Measurement method: Contact angle immediately after dripping Liquid volume 2.0 μL Analytical methods: droplet method, θ / 2 method [The resin film transfer process (imparting water-repellent properties)] A polypropylene film (PP film) was prepared as the resin film. The contact angle of the untreated PP film before the transfer process was 96°. The transfer process was performed on the untreated PP film using the following method: The roughened surfaces of metal molds A, B, C, and D were overlapped with the water-repellent surface of the untreated polypropylene film (PP film) before the transfer process, and hot-pressed using a press to transfer the roughened shapes of metal molds A, B, C, and D to the untreated polypropylene film (PP film). The hot-pressing conditions are shown in Table 4.

[0074] [Example 1] The resin film (PP film) of Example 1 was manufactured by using a metal mold A to perform the transfer process. Figure 11A scanning electron microscope image (1500x magnification) of the surface of a resin film (PP film) after a transfer process was performed using a copper plate (metal mold A) with a roughened shape A is shown. Figure 12 A scanning electron microscope image (5000x magnification) of the surface of a resin film (PP film) after a transfer process was performed using a copper plate (metal mold A) with a roughened shape A. The contact angle of the resulting resin film (PP film) after the transfer process is shown to be 116°, exhibiting high water repellency.

[0075] [Example 2] The resin film (PP film) of Example 2 was manufactured by performing the transfer process using a metal mold B. Figure 13 A scanning electron microscope image (1500x magnification) of the surface of a resin film (PP film) after a transfer process was performed using a copper plate (metal mold B) with a roughened shape B. Figure 14 A scanning electron microscope image (5000x magnification) of the surface of a resin film (PP film) after a transfer process was performed using a copper plate (metal mold B) with a roughened shape B. The contact angle of the resulting resin film (PP film) after the transfer process is shown to be 118°, exhibiting high water repellency.

[0076] [Example 3] The resin film (PP film) of Example 3 was manufactured by using a metal mold C to perform the transfer process. Figure 15 A scanning electron microscope image (1500x magnification) of the surface of a resin film (PP film) after a transfer process was performed using a copper plate (metal mold C) with a roughened shape C. Figure 16 A scanning electron microscope image (5000x magnification) of the surface of a resin film (PP film) after a transfer process was performed using a copper plate (metal mold C) with a roughened shape C. The contact angle of the resulting resin film (PP film) after the transfer process is shown to be 124°, exhibiting high water repellency.

[0077] [Example 4] The resin film (PP film) of Example 4 was manufactured by using a metal mold D to perform the transfer process. Figure 17 A scanning electron microscope image (1500x magnification) of the surface of a resin film (PP film) after a transfer process was performed using a copper plate (metal mold D) with a roughened shape D is shown. Figure 18 A scanning electron microscope image (5000x magnification) of the surface of a resin film (PP film) after a transfer process was performed using a copper plate (metal mold A) with a roughened shape D is shown. The resin film (PP film) obtained after the transfer process shows a contact angle exceeding 140°, exhibiting high water repellency.

[0078] Table 2 shows the contact angles of the untreated PP film before the transfer process (Comparative Example 1) and the PP films that underwent the transfer process in Examples 1-4. The contact angles of the PP films in Examples 1-4 were all increased by more than 10°, indicating that they could impart excellent water repellency.

[0079] [Table 2]

[0080] [Transfer process of resin film (imparting hydrophilicity)] A poly(meth)acrylic acid film (Acryl film) was prepared as the resin film. The contact angle of the untreated Acryl film before the transfer process was 84°. The transfer process was carried out on the untreated Acryl film using the following method: Acryl raw material was poured into the roughened surfaces of metal molds A, B, C, and D, and after UV curing, the resin film was demolded to produce a film with the roughened shapes of metal molds A, B, C, and D transferred onto it. The hot pressing conditions are shown in Table 4.

[0081] [Example 5] The resin film (Acryl film) of Example 5 was manufactured by using a metal mold A to perform the transfer process. Figure 19 A scanning electron microscope image (1500x magnification) of the surface of a resin film (Acryl film) after a transfer process was performed using a copper plate (metal mold A) with a roughened shape A is shown. Figure 20 A scanning electron microscope image (5000x magnification) of the surface of a resin film (Acryl film) after a transfer process was performed using a copper plate (metal mold A) with a roughened shape A. The resin film (Acryl film) obtained after the transfer process has a contact angle of 65°, exhibiting high hydrophilicity.

[0082] [Example 6] The resin film (Acryl film) of Example 6 was manufactured by using a metal mold B to perform the transfer process. Figure 21 A scanning electron microscope image (1500x magnification) of the surface of a resin film (Acryl film) after a transfer process was performed using a copper plate (metal mold B) with a roughened shape B is shown. Figure 22 A scanning electron microscope image (5000x magnification) of the surface of a resin film (Acryl film) after a transfer process was performed using a copper plate (metal mold B) with a roughened shape B. The contact angle of the resin film (Acryl film) obtained after the transfer process is shown to be 46°, exhibiting high hydrophilicity.

[0083] Table 3 shows the contact angles of the untreated Acryl film before the transfer process (Comparative Example 2) and the Acryl films that underwent the transfer process in Examples 5 and 6. The contact angles of the Acryl films in Examples 5 and 6 were all reduced by more than 10°, indicating that they could impart excellent hydrophilicity.

[0084] [Table 3]

[0085] [The resin film transfer process (to impart antiviral properties)] A transfer process is performed by overlapping the roughened surfaces of metal molds A, B, C, and D with the surfaces of untreated resin films (polypropylene (PP) film and poly(meth)acrylic acid (Acryl) film) to be treated with antiviral agents before the transfer process, and then hot-pressing them using a press. The roughened shapes of metal molds A, B, C, and D are transferred to the untreated resin films (polypropylene (PP) film and poly(meth)acrylic acid (Acryl) film) using a press. The hot-pressing conditions are shown in Table 4.

[0086] [Table 4]

[0087] [Examples 7-8] The resin film (PP film) of Examples 7-8 was manufactured by using a metal mold B to perform the transfer process.

[0088] [Example 9] The resin film (PP film) of Example 9 was manufactured by using a metal mold C to carry out the transfer process.

[0089] [Examples 10-11] The resin film (PP film) of Examples 10-11 is manufactured by using a metal mold D to perform the transfer process.

[0090] [Examples 12-13] The resin films (Acryl films) of Examples 12-13 were manufactured by using a metal mold A to perform the transfer process.

[0091] Examples 14-15 The resin films (Acryl films) of Examples 14-15 were manufactured by using a metal mold B to perform the transfer process.

[0092] Examples 16-17 The resin films (Acryl films) of Examples 16-17 are manufactured by using a metal mold C to perform the transfer process.

[0093] Example 18 The resin film (Acryl film) of Example 18 is manufactured by using a metal mold D to perform the transfer process.

[0094] <Antiviral efficacy evaluation> Using Ref. (-) (glass plate) as an unprocessed product, the antiviral properties of the resin films (polypropylene film (PP film) and poly(meth)acrylic acid film (Acryl film)) manufactured in Examples 7 to 18 were evaluated under the following conditions.

[0095] [Testing Standards] Refer to JIS R1756:2020 (Visible light responsive photocatalyst, antiviral, membrane close-fitting method) [No product name specified] Ref. (-) (Glass plate) [Test Sample Name] The resin films (polypropylene film (PP film) and poly(meth)acrylic acid film (Acryl film)) manufactured in Examples 7-18 [Size of test samples (PP film and Acryl film)] 50 mm × 50 mm × t ≤ 1 mm [n number] n=1 [Experimental bacteriophage] • Phage Qβ (NBRC 20012) [host Escherichia coli (NBRC 106373)]; results are shown in Tables 5 and 7.

[0096] • Phage ϕ6 (NBRC 105899, outside JIS standard) [host Pseudomonas syringae (NBRC 14084)]; results are shown in Tables 6 and 8.

[0097] [Dilution of the experimental bacteriophage] 1 / 500NB [Sterilization of the test samples] Sterilize with UV254 nm (15 minutes each for the front and back sides). [Action conditions] Temperature 25℃, dark place, contact time 0 hours, 8 hours [Adhesive film] Polypropylene film (VF-10, KOKUYO), 40 mm × 40 mm [Table 5]

[0098] As shown in Table 5, the PP films obtained in Examples 7, 9, and 10 exhibited a significant decrease in infectivity against bacteriophage Qβ (a norovirus substitute) after 8 hours in the dark at 25°C. Furthermore, their antiviral activity also increased after 8 hours in the dark at 25°C. These results suggest that the PP films subjected to the transfer process using metal molds B, C, and D exhibit a significant antiviral effect due to the formation of highly complex roughened shapes on their surface.

[0099] [Table 6]

[0100] As shown in Table 6, the PP films obtained in Examples 8 and 11 exhibited a significant decrease in infectivity against bacteriophage ϕ6 (influenza virus, a COVID-19 substitute) after 8 hours in the dark at 25°C. Furthermore, their antiviral activity also increased after 8 hours in the dark at 25°C. These results indicate that the PP films subjected to the transfer process using metal molds B and D exhibit a significant antiviral effect due to the formation of a very complex roughened shape on the surface of the PP film.

[0101] [Table 7]

[0102] As shown in Table 7, the Acryl films obtained in Examples 12, 14, and 16 exhibited a significant decrease in infectivity against bacteriophage Qβ (a norovirus substitute) after 8 hours in the dark at 25°C. Furthermore, their antiviral activity also increased after 8 hours in the dark at 25°C. These results suggest that the Acryl films subjected to the transfer process using metal molds A, B, and C exhibit a significant antiviral effect due to the formation of highly complex, roughened shapes on their surface.

[0103] [Table 8]

[0104] As shown in Table 8, the Acryl films obtained in Examples 13, 15, 17, and 18 exhibited a significant decrease in infectivity against bacteriophage ϕ6 (influenza virus, a COVID-19 substitute) after 8 hours in the dark at 25°C. Furthermore, their antiviral activity also increased after 8 hours in the dark at 25°C. These results suggest that the Acryl films subjected to the transfer process using metal molds A, B, C, and D exhibit a significant antiviral effect due to the formation of highly complex, roughened shapes on their surface.

Claims

1. A method for manufacturing a resin film, characterized in that: The resin film has a roughened shape on at least a portion of its surface. The method for manufacturing the resin film includes a transfer printing step, wherein the transfer printing step involves contacting a metal mold with at least a portion of its roughened surface with the resin film, thereby transferring the roughened shape of the roughened surface to the resin film. The roughened surface of the metal mold has an unfolded area ratio (Sdr) of 0.005 to 0.5 as measured according to ISO 25178, and a root mean square slope (Sdq) of 0.1 to 1.

5.

2. The method for manufacturing the resin film according to claim 1, wherein, In the transfer process, at least a portion of the surface of the resin film is given water-repellent properties.

3. The method for manufacturing the resin film according to claim 2, wherein, The contact angle between the resin film and water before the transfer process is greater than 90°.

4. The method for manufacturing the resin film according to claim 1, wherein, In the transfer process, at least a portion of the surface of the resin film is made hydrophilic.

5. The method for manufacturing the resin film according to claim 4, wherein, The contact angle between the resin film and water before the transfer process is less than 90°.

6. The method for manufacturing a resin film according to claim 1, wherein, In the transfer process, at least a portion of the surface of the resin film is endowed with antiviral properties.

7. A metal casting mold, characterized in that: The metal mold is used to form a roughened shape on at least a portion of the surface of the resin film. The metal mold has a roughened surface on at least a portion of its surface for transferring the roughened shape to the resin film. The roughened surface has an unfolded area ratio (Sdr) of 0.005 to 0.5 as measured according to ISO 25178, and a root mean square slope (Sdq) of 0.1 to 1.5.

Images