Structure and marine organism adhesion prevention method

Abstract

To provide a structure exhibiting excellent marine organism adhesion prevention to an underwater structure, and a marine organism adhesion prevention method using the structure.SOLUTION: This structure having a hole irregular structure on the surface of a blank and used for preventing marine organism adhesion to an underwater structure is constructed such that a Young's modulus of the blank is less than 3.0 GPa, and the hole irregular structure has a hole diameter of 30 μm or more and 100 μm or less, an inter-hole distance of 10 μm or more and 100 μm or less, and a hole depth of 40 μm or more.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a structure used for preventing adhesion of marine organisms, and a method for preventing adhesion of marine organisms using said structure. [Background technology]

[0002] Conventionally, antifouling paints have been known that apply metal-type antifouling agents, mainly cuprous oxide, to underwater structures to prevent adhesion of marine organisms to the structures and release antifouling components. However, when such conventional antifouling paints are used, there are concerns about the impact on the environment, and therefore a safer method is required. In light of this background, relatively low-toxicity silicone-based antifouling paints or sheets are also known. However, there is also a problem that when the antifouling components in the coating film run out, it is difficult to overcoat a new silicone-based coating film on top of the silicone-based coating film. For this reason, a method that is effective for a long period of time and easy to renew the coating film (removal of the old coating and reapplication) is required.

[0003] Meanwhile, unlike the conventional method of using antifouling paint, a method is also known in which small irregularities are formed on the surface of an underwater structure to prevent adhesion of marine organisms (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-261385 A Summary of the Invention [Problem to be solved by the invention]

[0005] Although the method described in Patent Document 1 has been shown to be somewhat effective in preventing adhesion of marine organisms, the effect is not sufficient.

[0006] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a structure that is excellent in preventing adhesion of marine organisms to underwater structures, and a method for preventing adhesion of marine organisms using said structure. [Means for solving the problem]

[0007] The present inventors have found that the above problems can be solved by using a structure having a specific hole uneven structure on the surface of a material having a specific Young's modulus, and have completed the present invention.

[0008] A first aspect of the present invention is a structure used to prevent adhesion of marine organisms to an underwater structure, the structure having a hole-relief structure on a surface of a material, The Young's modulus of the material is less than 3.0 GPa; The hole concavo-convex structure has a hole diameter of 30 μm or more and 100 μm or less, a hole distance of 10 μm or more and 100 μm or less, and a hole depth of 40 μm or more.

[0009] A second aspect of the present invention is a method for preventing adhesion of marine organisms to an underwater structure, comprising providing a structure according to the first aspect on a surface of the underwater structure. Effect of the Invention

[0010] According to the present invention, it is possible to provide a structure that is excellent in preventing adhesion of marine organisms to underwater structures, and a method for preventing adhesion of marine organisms using said structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] ≪Structure≫ The structure has a hole-relief structure on the surface of the material. The structures are used to prevent attachment of marine organisms to underwater structures. The Young's modulus of the material is less than 3.0 GPa. The hole concave-convex structure has a hole diameter of 30 μm or more and 100 μm or less, a hole distance of 10 μm or more and 100 μm or less, and a hole depth of 40 μm or more.

[0012] The material of the structure has a specific Young's modulus, and the surface of the material has a specific hole-relief structure, so that the structure has an excellent effect of preventing adhesion of marine organisms to the underwater structure.

[0013] Required and optional aspects of the structure will be described below.

[0014] <Material properties of the structure> The Young's modulus of the material forming the structure is less than 3.0 GPa, preferably less than 2.5 GPa, and more preferably less than 2.0 GPa, from the viewpoint of excellent effect of preventing adhesion of marine organisms. The lower limit of the Young's modulus of the material is not particularly limited, and is preferably 0.002 GPa or more, and more preferably 0.004 GPa or more. In this specification, the Young's modulus is measured in accordance with ISO14577.

[0015] The material having the above Young's modulus is not particularly limited as long as it is a resin, a photocurable resin composition, or a thermosetting resin composition.

[0016] Examples of the resin include polydimethylsiloxane, polyester, polyester urethane, cyclic cycloolefin copolymer, thermoplastic polyurethane, acrylic resin, and polystyrene.

[0017] <Other material properties of the structure> The material properties of the structure may include other properties described below in addition to the Young's modulus. Examples of other properties include surface free energy.

[0018] The surface free energy of the material forming the structure is set to 40 mJ / m from the viewpoint of excellent effectiveness in preventing adhesion of marine organisms. 2 More than 80mJ / m 2 It is preferable that the concentration is less than 40 mJ / m 2 More than 70mJ / m 2 More preferably, it is 40 mJ / m or less. 2More than 60mJ / m 2 It is more preferable that the surface free energy is not more than 100 nm. In this specification, the surface free energy is determined by measuring the contact angle of various liquid droplets on the surface of the above-mentioned structure.

[0019] Specifically, using a contact angle meter, droplets of pure water and methylene iodide are dropped onto the surface of the structure at a temperature of 25°C and a relative humidity of 50%, and the contact angle is measured one second after the droplet adheres to the surface. The contact angle is then calculated from the respective contact angles obtained according to the Owens-Wendt method.

[0020] <Hole uneven structure> The hole concave-convex structure means a pattern structure in which two or more isolated holes are formed on the surface of a material. The shape of the isolated hole is not particularly limited, and examples thereof include, in plan view, a circle, an ellipse, a polygon such as a triangle or a quadrangle (square or rectangle), an irregular shape, etc. Among these, a circle and a square are preferred, and a circle is more preferred.

[0021] From the viewpoint of being highly effective in preventing adhesion of marine organisms, the hole uneven structure has a hole diameter of 30 μm or more and 100 μm or less, a hole distance of 10 μm or more and 100 μm or less, and a hole depth of 40 μm or more. The hole diameter means the diameter when the hole is circular, the major axis when the hole is elliptical, the length of one side when the hole is square, and the length of the major side when the hole is rectangular. The distance between holes means the distance between the center of one hole and the center of the adjacent hole. The hole depth means the vertical downward distance from the center of the hole to the deepest part of the hole on the surface of the hole relief structure.

[0022] The hole diameter is preferably 30 μm or more and 80 μm or less, and more preferably 30 μm or more and 60 μm or less. The distance between the holes is preferably 10 μm or more and 80 μm or less, and more preferably 10 μm or more and 60 μm or less. The hole depth is preferably 50 μm or more, more preferably 60 μm or more, even more preferably 70 μm or more, even more preferably 80 μm or more, and particularly preferably 85 μm or more. The upper limit of the hole depth is preferably 100 μm or less.

[0023] <Structure Form> The form of the structure is not particularly limited, and is preferably, for example, a sheet. The thickness of the sheet is not particularly limited, and is preferably 50 μm or more and 3000 μm or less, more preferably 100 μm or more and 2000 μm or less, and even more preferably 200 μm or more and 1500 μm or less, from the viewpoint of not being altered or deteriorated even when immersed in seawater for a long period of time. In this specification, a film is included as one embodiment of a sheet.

[0024] <Application> The structures are used to prevent attachment of marine organisms to underwater structures. The underwater structure refers to a structure that exists in seawater. Examples of the underwater structure include ships, various fishing nets, port facilities, oil fences, piping, bridges, undersea bases, and undersea housing. The marine organisms refer to organisms that live in the ocean and can attach to the underwater structure, particularly large marine organisms. Large marine organisms are those that grow to a size that allows individual visual observation, such as animals such as barnacles, mussels, oysters, hydroids, bryozoans, sea squirts, and serpula, and plants such as Ulva and Salvia officinalis.

[0025] <Methods for preventing marine organisms from attaching> The method for preventing adhesion of marine organisms to an underwater structure is not particularly limited, and includes, for example, providing the structure on the surface of the underwater structure. Specifically, it is preferable to cover the submerged portion of the underwater structure with the structure. The method for covering the structure is not particularly limited, and examples thereof include a method of applying an adhesive or paint to the back surface of the structure and / or the surface of the underwater structure, and attaching the structure to the underwater structure. The above-mentioned structure may also be attached to the surface of an underwater structure via a double-sided adhesive sheet having adhesive layers formed on both sides. Furthermore, before the underwater structure is placed in water, the structures can be formed on the surface of the underwater structure by a method such as an imprint method or a printing method, which will be described later.

[0026] <Manufacturing method of structure> The method for producing the structure is not particularly limited. For example, the structure can be produced by using an imprint method in which a pillar uneven structure formed on a mold is transferred to the above-mentioned material. The pillar uneven structure is a pattern structure in which two or more isolated pillars are formed, and refers to a transfer pattern. In the pillar uneven structure, a fine structure corresponding to the hole uneven structure is formed so that the hole uneven structure described above is formed after transfer. The fine structure preferably has a pillar diameter, a pillar distance, and a pillar height corresponding to the hole uneven structure.

[0027] As the imprinting method, a known method can be appropriately used, and for example, the following methods 1 to 3 can be used. Method 1: A method including pressing a transfer pattern of a pillar concave-convex structure formed on a mold onto a molded body (e.g., a sheet) formed from the material to transfer the transfer pattern to the molded body, and releasing the mold from the molded body after transfer. Method 2: A method including pouring the above-mentioned material into a transfer pattern of a pillar concave-convex structure formed in a mold, hardening the material to transfer the transfer pattern to the material, and releasing the mold from a molded body made of the material after transfer. Method 3: A method comprising: applying a photosensitive resin composition as a material to the surface of a substrate; pressing a transfer pattern of a pillar uneven structure formed on a mold onto the resulting coating; photo-curing the coating to transfer the transfer pattern to the coating; and releasing the mold from the cured film after transfer.

[0028] In method 1, the above molded body can be obtained, for example, by bar-coating the above material onto a release film, and then laminating the resulting film.

[0029] <Other examples of manufacturing methods for structures> The structure can also be manufactured by a photolithography method using a photomask for forming a hole pattern and a photosensitive resin composition. As the photosensitive resin composition, either a negative type resin composition or a positive type resin composition can be used. Specifically, after forming a photosensitive resin composition layer on a substrate, the photosensitive resin composition layer is exposed to light and developed to form a structure. In this case, the thickness of the photosensitive composition layer corresponds to the depth of the hole. The structure can also be manufactured by a printing method such as an inkjet method, in which ink droplets are ejected to form holes of a predetermined depth, forming the portions of the structure other than the holes. Furthermore, the structure may be a woven fabric woven to form holes of the above-mentioned predetermined size. In the woven fabric, the gaps between the fibers correspond to the holes. In this case, the fiber diameter of the fibers constituting the woven fabric is selected so that the distance between the holes is the above-mentioned predetermined distance between the holes and the hole depth is the above-mentioned predetermined depth. The weaving method of the woven fabric may be either a plain weave or a twill weave. EXAMPLES

[0030] The present invention will be described in more detail below by showing examples, but the scope of the present invention is not limited to these examples.

[0031] <Examples 1 to 13 and Comparative Examples 1 to 4> In the examples and comparative examples, the following materials 1 to 6 were used as materials for the structures. Material 1: SYLGARD 184 (polydimethylsiloxane, manufactured by Dow Chemical Company) Material 2: G-7 (polyester, 200 μm thick, manufactured by Kuraray Industries, Ltd.) Material 3: Vylon UR-8300 (polyester urethane, manufactured by Toyobo) Material 4: APL6509T (cyclic cycloolefin copolymer, manufactured by Mitsui Chemicals) Material 5: Resin pellets (TPU (thermoplastic polyurethane), product number: RPELLET0029, Standard Test Piece official online shop) Material 6: TMMR S2000 (photosensitive resin composition, 2000cP, manufactured by Tokyo Ohka Kogyo Co., Ltd.)

[0032] In the examples and comparative examples, the following devices were used as a laminator for laminating, a small press for heat pressing, and a bar coater for forming a bar coat film. Laminating machine: FA-570 (manufactured by Taisei Laminator Co., Ltd.) Press machine: H300-05 (As One) Bar coater: No. 75 (As One)

[0033] Example 1 Material 6 was spin-coated onto a silicon wafer, and the film obtained was exposed and developed through a PET film mask having a hole pattern to obtain a pillar pattern with a pillar diameter of 40 μm, a pillar distance of 25 μm, and a pillar height of 90 μm. Material 1 was poured into the obtained pillar pattern as a mold and thermally cured at 150° C. The mold was then released from the cured material 1 to obtain a 1000 μm thick sheet having the hole pattern shown in Table 1.

[0034] Example 2 Using the laminator, five sheets of material 2 were laminated onto a release PET film to obtain a sheet having a thickness of 900 μm. The pillar pattern surface of a Ni mold was brought into contact with the obtained sheet, and the sheet was heat-pressed at 100° C. under a load of 0.5 tons and held for 5 minutes. After cooling to room temperature, the mold was released from material 2 to obtain a sheet having a thickness of 700 μm and having the hole pattern shown in Table 1. The mold used had a pillar pattern surface with a pillar diameter of 40 μm, a pillar distance of 25 μm, and a pillar height of 90 μm.

[0035] Example 3 Material 3 was bar-coated on a release PET film and then laminated to obtain a sheet with a thickness of 1200 μm. The pillar pattern surface of a Ni mold was brought into contact with the obtained sheet, and the sheet was heat-pressed at 80° C. under a load of 1 ton and held for 5 minutes. After cooling to room temperature, the mold was released from material 3 to obtain a sheet with a thickness of 500 μm having the hole pattern shown in Table 1. The mold used was the same as that used in Example 2.

[0036] Example 4 The pellets of material 4 were hot-pressed at 130°C under a load of 1.5 tons, held for 3 minutes, and cooled to room temperature to obtain a sheet with a thickness of 300 μm. Three of these sheets were stacked, and the pillar pattern surface of a Ni mold was brought into contact with the obtained sheet, and the sheet was hot-pressed at 130°C under a load of 1 ton and held for 5 minutes. After cooling to room temperature, the mold was released from material 4 to obtain a sheet with a thickness of 600 μm having the hole pattern shown in Table 1. The mold used was the same as that used in Example 2.

[0037] Example 5 The pellets of material 5 were hot-pressed at 200°C under a load of 1 ton, held for 1 minute, and cooled to room temperature to obtain a sheet with a thickness of 600 μm. The pillar pattern surface of a Ni mold was brought into contact with the obtained sheet, and hot-pressed at 200°C under a load of 1 ton and held for 5 minutes. After cooling to room temperature, the mold was released from material 5 to obtain a sheet with a thickness of 300 μm having the hole pattern shown in Table 1. The mold used was the same as that used in Example 2.

[0038] (Examples 6 to 13) A 1000 μm thick sheet having the hole pattern shown in Table 1 was obtained in the same manner as in Example 1, except that the pillar pattern in Example 1 was replaced with the pillar pattern shown below. Example 6: Pillar pattern with pillar diameter of 40 μm, pillar distance of 15 μm, and pillar height of 90 μm Example 7: Pillar pattern with pillar diameter of 40 μm, pillar distance of 45 μm, and pillar height of 90 μm Example 8: Pillar pattern with pillar diameter of 40 μm, pillar distance of 60 μm, and pillar height of 90 μm Example 9: Pillar pattern with pillar diameter of 30 μm, pillar distance of 15 μm, and pillar height of 90 μm Example 10: Pillar pattern with pillar diameter of 60 μm, pillar distance of 15 μm, and pillar height of 90 μm Example 11: Pillar pattern with pillar diameter of 100 μm, pillar distance of 15 μm, and pillar height of 90 μm Example 12: Pillar pattern with pillar diameter of 40 μm, pillar distance of 15 μm, and pillar height of 125 μm Example 13: Pillar pattern with pillar diameter of 40 μm, pillar distance of 15 μm, and pillar height of 45 μm

[0039] Comparative Example 1 Material 6 was spin-coated onto a silicon wafer to form a film, and the film obtained was exposed to light and developed through a PET film mask having a dot pattern to obtain a 90 μm-thick resist film having the hole pattern shown in Table 1.

[0040] (Comparative Examples 2 to 3) A 1000 μm thick sheet having the hole pattern shown in Table 1 was obtained in the same manner as in Example 1, except that the pillar pattern in Example 1 was replaced with the pillar pattern shown below. Comparative Example 2: Pillar pattern with pillar diameter of 20 μm, pillar distance of 15 μm, and pillar height of 90 μm Comparative Example 3: Pillar pattern with pillar diameter of 40 μm, pillar distance of 15 μm, and pillar height of 90 μm

[0041] Comparative Example 4 Material 1 was thermally cured at 150°C to obtain a sheet having a thickness of 1000 µm.

[0042] <Evaluation> (larva attachment rate) Each sheet obtained in the above-mentioned Examples and Comparative Examples was placed as a test sample on the bottom surface of each polypropylene container (111 mm x 81 mm x 46 mm). In order to submerge each test sample in seawater, the back surface of each test sample and each container were fixed using a glue gun. Natural seawater filtered through a 0.45μm filter and approximately 100 cypris larvae of the Balanus fasciatus were placed in each of the above containers. The water temperature and other conditions during the test were room temperature of around 25℃, with light (laboratory lighting) during the day and darkness at night. 14 days after the start of the test, the number of cypris larvae attached to the surface of each test sample was counted, and the larvae attachment rate was calculated using the number of larvae introduced as the denominator. The results are shown in Table 1. In addition, when the larvae attachment rate in Table 1 is less than 10%, it is evaluated as having excellent effect of preventing attachment of cypris larvae.

[0043] (Surface Free Energy) Using a contact angle meter (Kyowa Interface Science Co., Ltd., "Dropmaster700"), droplets of pure water and methylene iodide were dropped onto the surface of each sheet produced in the Examples and Comparative Examples under conditions of a temperature of 25°C and a relative humidity of 50%, and the contact angle was measured 1 second after the droplets had attached to the surface, and the surface free energy was calculated from each of the obtained contact angles according to the Owens-Wendt method. The results are shown in Table 1. In Table 1, "SFE" stands for surface free energy.

[0044] (Young's Modulus) The Young's modulus of each of the sheets produced in the examples and comparative examples was measured in accordance with ISO 14577. The results are shown in Table 1.

[0045] [Table 1]

[0046] The results in Table 1 show that a sheet having a Young's modulus of less than 3.0 GPa and a hole uneven structure having a hole diameter of 30 μm or more, a hole distance of 10 μm or more, and a hole depth of 40 μm or more has excellent effectiveness in preventing the adhesion of the cypris larvae.

Claims

1. A structure used to prevent adhesion of marine organisms to an underwater structure, the structure having a hole-relief structure on the surface of a material, The Young's modulus of the material is less than 3.0 GPa; A structure, wherein the hole concavo-convex structure has a hole diameter of 30 μm or more and 100 μm or less, a hole distance of 10 μm or more and 100 μm or less, and a hole depth of 40 μm or more.

2. The surface free energy of the material is 40 mJ / m ２ 80mJ / m or more ２ 2. The structure of claim 1 , wherein:

3. The structure according to claim 1 or 2, wherein the structure is a sheet.

4. A method for preventing adhesion of marine organisms to an underwater structure, comprising providing the structure according to claim 1 or 2 on a surface of the underwater structure.

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