Aquatic biofouling prevention film and float coated with said aquatic biofouling prevention film

Abstract

The present disclosure aims to provide a film for inhibiting the adhesion of aquatic organisms, and a float coated with the film for inhibiting the adhesion of aquatic organisms. The present invention provides a film for inhibiting adhesion of aquatic organisms containing a polybutene copolymer, and a float having a float body covered with the film for inhibiting adhesion of aquatic organisms.

Description

[Technical Field]

[0001] The present disclosure relates to a film for inhibiting the adhesion of aquatic organisms, a float coated with the film for inhibiting the adhesion of aquatic organisms, and the like. [Background technology]

[0002] In recent years, marine plastic pollution has attracted considerable attention both domestically and internationally. Plastic waste that flows into the ocean deteriorates the marine environment, including ecosystems, and causes a variety of problems, including reduced coastal functions, adverse effects on coastal scenery, obstructions to ship navigation, and impacts on fisheries. Global plastic production has increased more than 20-fold over the 50 years from 1964 to 2014, and it is said that approximately 8 million tons of plastic is released into the ocean every year (Non-Patent Document 1). In particular, there is concern that fragments of plastic less than 5 mm in size, known as microplastics (MPs), may be ingested by living organisms and accumulate in their bodies.

[0003] As shown in Figure 1 (1-1), rafts for marine aquaculture and other uses buoyancy bodies called floats to obtain buoyancy. These floats are mainly made of polystyrene foam or hollow resin bodies. If hollow resin bodies are used, the microplastic problem caused by polystyrene foam will be reduced. However, the resin hollow body is more than three times as expensive as a polystyrene foam float, and therefore, at present, the cheaper polystyrene foam float is used. Aquatic organisms such as shellfish like barnacles, and crustaceans like crabs and shrimp attach (attach) to Styrofoam floats, drilling holes in them and using them as homes, causing the floats to become worn out within a few months to a few years, as shown in Figure 4. A worn Styrofoam float loses its buoyancy. For example, in the case of oyster farming rafts, Styrofoam floats that have lost their buoyancy cannot withstand the weight of the oysters as they grow, and the raft reaches a state such as that shown in Figure 1 (1-2). Furthermore, because such used Styrofoam floats absorb water and increase in weight, replacing them with new floats is quite hard work. Furthermore, as mentioned above, there is a problem in that the scraped polystyrene foam is released into the water and becomes microplastics, which are then ingested by fish and other living organisms along with their food. For example, in the western waters of Hiroshima Prefecture, more than 60% of the microplastics are polystyrene, which is used in polystyrene foam, and it is believed that one of the causes is the floats used in oyster rafts (Non-Patent Document 2).

[0004] Therefore, to improve durability, float products that are generally used as marine (aquaculture) floats consist of polystyrene foam floats covered with a polyethylene float cover (Figure 2). Even when covered with a float cover, the float product generally lasts for about five years, after which it is replaced with a new one. After removing the float cover from a used float product, the state of the float body is as shown in Figure 4, making reuse (horizontal recycling) difficult. Therefore, used floats are usually discarded, but when discarding floats, they are required to be disposed of as "industrial waste" under the Waste Disposal Act. However, because the cost of treating them as industrial waste is high, used floats are often illegally dumped without being treated as industrial waste. These floats float on the ocean and are further broken down by aquatic organisms, turning into microplastics that end up in the ocean, causing problems.

[0005] Therefore, it is an urgent task to prevent the outflow of "non-degradable marine debris" such as microplastics. To achieve this, it is first important to prevent aquatic organisms from attaching to floats, and furthermore, it is required to make it possible to "recover," "recycle," or "commercialize" the floats. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Chosei, No. 105 (May 2021), pp. 16-19 [Non-patent document 2] Chugoku Shimbun, Microplastics Abound in Central Hiroshima Prefecture, Friday, June 9, 2023 (Reiwa 5) Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure aims to provide a film for inhibiting the adhesion of aquatic organisms, which can inhibit the adhesion of aquatic organisms, and a float covered with the film for inhibiting the adhesion of aquatic organisms. [Means for solving the problem]

[0008] The present inventors have conducted extensive research to solve the above-mentioned problems and have found that a film containing a polybutene copolymer exhibits an effect of inhibiting the adhesion of aquatic organisms. The present disclosure has been completed based on this finding.

[0009] That is, the present disclosure is as follows. [1] A film for inhibiting biofouling in water, containing a polybutene copolymer. [2] The film for inhibiting the adhesion of aquatic organisms according to [1], wherein the polybutene copolymer is a polybutene-olefin copolymer. [3] The film for inhibiting the adhesion of aquatic organisms according to [1] or [2], further comprising an ethylene-octene copolymer. [4] A float having a float body covered with the film for inhibiting adhesion of aquatic organisms according to any one of [1] to [3]. [5] A float product comprising a float coated with the film for inhibiting adhesion of aquatic organisms described in [4], and a float cover that further covers the float coated with the film for inhibiting adhesion of aquatic organisms. [6] A float coated with a film for inhibiting adhesion of aquatic organisms according to [4] or [5], further comprising an information tag storing individual identification information. [7] A float coated with a film for inhibiting adhesion of aquatic organisms according to [6], wherein the information tag includes an IC chip. [8] A method for horizontally recycling floats, comprising a step of recovering floats coated with the aquatic organism adhesion suppression film described in [4]. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a film for inhibiting the adhesion of aquatic organisms, and a float coated with the film for inhibiting the adhesion of aquatic organisms. [Brief explanation of the drawings]

[0011] [Figure 1] Figure 1 shows photographs of aquaculture rafts. (1-1) shows a raft with normal buoyancy due to the floats. (1-2) shows a tilted raft with the floats corroded and losing buoyancy. (1-3) shows the replacement of the floats. [Figure 2] Figure 2 shows photographs of commercially available float products. (2-1) is a photograph showing a float product covered with an orange float cover. (2-2) is a photograph showing a float product covered with a black float cover. (2-3) is a photograph showing a float product covered with a black mesh float cover. [Figure 3] Figure 3 is a schematic diagram showing the structure of a commercially available float product. (3-1) is a front cross-sectional view. (3-2) is a right side cross-sectional view. [Figure 4] FIG. 4 is a photograph of a float product (Comparative Example 1) covered with a commercially available float cover, which was used in the ocean for five years, and the float body after the float cover was removed. [Figure 5] 5A and 5B are schematic diagrams showing the configuration of an aquatic biofouling-suppressing float and a float product coated with an aquatic biofouling-suppressing film according to a second embodiment of the present disclosure. (5-1) is a front cross-sectional view. (5-2) is a right side cross-sectional view. (5-3) is a schematic enlarged view of a portion of the front cross-sectional view. [Figure 6] Figure 6 is a diagram corresponding to Table 1. Specifically, it is a photograph of the float body or film-covered float, and the appearance of the float covered with the float cover, before testing in Example 1, Comparative Example 1, and Comparative Example 2. [Figure 7] 7 is a diagram corresponding to Table 1. Specifically, it shows the test results of Example 1, Comparative Example 1, and Comparative Example 2, as well as photographs showing the results after use (after testing). [Figure 8] Figures 8 (8-1) and (8-2) are photographs of cross-sections (C is cross-section 1, and D is cross-section 2) of the float body of Example 1 after the test, with the float cover and the film for inhibiting adhesion of aquatic organisms removed. [Figure 9] Figure 9 is a photograph of the information tag. [Figure 10] 10A and 10B are schematic diagrams showing an aquatic biofouling-inhibiting float covered with an aquatic biofouling-inhibiting film according to a third embodiment of the present disclosure, with an information tag placed inside the float body. (10-1) is a front cross-sectional view, and (10-2) is a right side cross-sectional view. DETAILED DESCRIPTION OF THE INVENTION

[0012] Film for preventing aquatic biofouling The aquatic biofouling control film of the present disclosure contains a polybutene copolymer.

[0013] The polybutene copolymer is not particularly limited as long as it contains at least polybutene, and commercially available copolymers can be used. The copolymer can also be called a resin.

[0014] Polybutene includes normal butene (also called n-butene) alone (homopolymer); copolymers of normal butene with other monomers such as olefins (also called polybutene-olefin copolymers or butene-olefin copolymers); and the like.

[0015] The olefin is not particularly limited, and examples thereof include ethylene, propylene, and isopropylene. Olefin polymers can be referred to as polyolefins. Examples of polyolefins include polyethylene (PE) and polypropylene (PP). Polyethylene can be rephrased as polyethylene-based resin, polyethylene resin, etc. Polypropylene can be rephrased as polypropylene-based resin, polypropylene resin, etc. Specifically, in the polybutene-olefin copolymer, examples of the olefin polymer (polyolefin) include polyethylenes such as low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-α-olefin copolymer, and ethylene-(meth)acrylic acid copolymer. Examples of polypropylene include homopolypropylene, block polypropylene, and random polypropylene.

[0016] The polybutene copolymer of the present disclosure may be obtained by a general production method, but methods using a metallocene catalyst, a Ziegler-Natta catalyst, a radical initiator, or the like are preferred. The polybutene copolymer of the present disclosure is preferably a metallocene-based polybutene copolymer, more preferably a metallocene-based polybutene-olefin copolymer. It is also possible to use a metallocene-based polybutene copolymer in combination with a polybutene copolymer produced without using a metallocene-based catalyst. The content of polybutene is not particularly limited. In the butene-olefin copolymer, the mass ratio of butene to olefin is preferably 5:95 to 95:5, and more preferably 10:90 to 90:10.

[0017] The aquatic biofouling-inhibiting film of the present disclosure can be produced by further mixing (blending) an ethylene-α-olefin copolymer such as an ethylene-octene copolymer in addition to the polybutene copolymer. The aquatic biofouling-inhibiting film of the present disclosure preferably contains a butene-olefin copolymer and an ethylene-octene copolymer. Octene (C8H 16 ) is not particularly limited, and examples thereof include the α-olefin 1-octene. Polymerization of isobutene and 1-butene can yield various useful structural isomers of octene.

[0018] The ethylene-octene copolymer is not particularly limited, and commercially available products can be used. In the ethylene-octene copolymer, the mass ratio of ethylene to octene is preferably 5:95 to 95:5, and more preferably 10:90 to 90:10. The ethylene-octene copolymer may be one obtained by a general production method, but methods using a metallocene catalyst, a Ziegler-Natta catalyst, a radical initiator, or the like are preferred. The ethylene-octene copolymer in the present disclosure is preferably a metallocene-based polybutene copolymer, more preferably a metallocene-based polybutene-olefin copolymer. It is also possible to use a metallocene-based ethylene-octene copolymer in combination with an ethylene-octene copolymer produced without using an ethylene-octene copolymer.

[0019] In the case of a butene-olefin copolymer and an ethylene-octene copolymer as the polybutene copolymer of the present disclosure, for example, the content of the butene-olefin copolymer is typically 50% by mass or less, preferably 40% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less or 12% by mass or less, and particularly preferably 10% by mass or less, relative to the total mass of the polybutene copolymer. The content of the ethylene-octene copolymer is typically 50% by mass or more, preferably 60% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more or 88% by mass or more, and particularly preferably 90% by mass or more, based on the total mass of the polybutene copolymer.

[0020] Among these, the aquatic biofouling suppression film containing a butene-olefin copolymer and an ethylene-octene copolymer preferably contains more than 0 mass % and not more than 40 mass % of the butene-olefin copolymer and 60 mass % or more and 100 mass % or less of the ethylene-octene copolymer; More preferably, the butene-olefin copolymer is more than 0 mass% and 20 mass% or less, and the ethylene-octene copolymer is 80 mass% or more and 100 mass% or less; More preferably, the butene-olefin copolymer is more than 0 mass% and 15 mass% or less, and the ethylene-octene copolymer is 85 mass% or more and 100 mass% or less; Particularly preferably, the butene-olefin copolymer is more than 0 mass % and 10 mass % or less, and the ethylene-octene copolymer is 90 mass % or more and 100 mass % or less.

[0021] The aquatic biofouling inhibitor film of the present disclosure may also be a laminate containing the polybutene copolymer. When it is a laminate, there are no particular limitations on the laminate of the film for inhibiting adhesion of aquatic organisms, and it may be, for example, a two-layer laminate consisting of layer A and layer B in that order, or a three-layer laminate consisting of layer A, layer B, and layer C in that order.

[0022] For example, when two layers are laminated in the order of layer A and layer B, the film for inhibiting aquatic biofouling of the present disclosure may have layer A being a butene-olefin copolymer and layer B being an ethylene-octene copolymer. Furthermore, when the three layers are laminated in the order of Layer A, Layer B, and Layer C, the aquatic biofouling suppression film of the present disclosure may have Layer A being a butene-olefin copolymer, Layer B being an ethylene-octene copolymer, and Layer C being a butene-olefin copolymer; or The A layer may be an ethylene-octene copolymer, the B layer may be a butene-olefin copolymer, and the C layer may be an ethylene-octene copolymer, etc.

[0023] In the aquatic biofouling suppression film of the present disclosure, layer A and layer B can be laminated directly or via an adhesive or adhesive resin, and layer B and layer C can be laminated directly or via an adhesive or adhesive resin. Examples of layer configurations of the aquatic biofouling-inhibiting film of the present disclosure include Layer A / Layer B / Layer C, Layer A / Layer X / Layer B / Layer C, Layer A / Layer B / Layer Y / Layer C, Layer A / Layer X / Layer B / Layer Y / Layer C, Layer A / Layer X / Layer B / Layer Y / Layer C, Layer M / Layer A / Layer X / Layer B / Layer Y / Layer C / Layer N, etc. Here, Layer X and / or Layer Y can be a layer of an adhesive or adhesive resin, or a layer of a resin other than Layer A, Layer B, and Layer C of the present disclosure. Layer M and / or Layer N can be a layer of a resin other than Layer A, Layer B, Layer C, Layer X, and Layer Y of the present disclosure. In the aquatic biofouling-inhibiting film of the present disclosure, Layer A is preferably the innermost layer and Layer C is the outermost layer. The aquatic biofouling-inhibiting film of the present disclosure is preferably a three-layer aquatic biofouling-inhibiting film in which Layer A, Layer B, and Layer C are directly laminated in this order.

[0024] When the aquatic biofouling prevention film of the present disclosure uses a metallocene-based polybutene copolymer, for example, a metallocene-based butene-olefin copolymer or a metallocene-based ethylene-octene copolymer, a known metallocene catalyst can be used as the metallocene catalyst. For example, the metallocene catalyst may be a known metallocene catalyst for olefin polymerization, such as a combination of a metallocene compound of a transition metal of Group IV or V of the periodic table with an organoaluminum compound and / or an ionic compound, or a combination of an organoaluminum oxy compound and a transition metal compound of Group IV or V of the periodic table containing a ligand having a cyclopentadienyl skeleton.

[0025] As the transition metal of Group IV or V of the periodic table, titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), and the like are preferred.

[0026] The metallocene compound may be any known metallocene compound having a ligand bridged with at least one cyclopentadienyl group, substituted cyclopentadienyl group, hydrocarbyl silicon, or the like, or a cyclopentadienyl group bridged with an oxygen atom, nitrogen atom, or phosphorus atom.

[0027] Specific examples of these metallocene compounds include silicon-bridged metallocene compounds such as dimethylsilyl(2,4-dimethylcyclopentadienyl)(3',5'-dimethylcyclopentadienyl)zirconium dichloride and dimethylsilyl(2,4-dimethylcyclopentadienyl)(3',5'-dimethylcyclopentadienyl)hafnium dichloride; and indenyl-bridged metallocene compounds such as ethylene bisindenyl zirconium dichloride, ethylene bisindenyl hafnium dichloride, ethylene bis(methylindenyl)zirconium dichloride and ethylene bis(methylindenyl)hafnium dichloride.

[0028] The organoaluminum compound used in combination with the metallocene compound in the present disclosure is a linear or cyclic polymer represented by the general formula (-Al(R)O-)n (wherein R is a hydrocarbon group having 1 to 10 carbon atoms, including those partially substituted with halogen atoms and / or R-O groups, and n is the degree of polymerization, which is 5 or more, preferably 10 or more). Specific examples include methylalumoxane, ethylalumoxane, and isobutylethylalumoxane, in which R is a methyl, ethyl, or isobutyl group, respectively.

[0029] Furthermore, other organoaluminum compounds are not particularly limited, and examples thereof include trialkylaluminum, dialkylhalogenoaluminum, sesquialkylhalogenoaluminum, alkenylaluminum, dialkylhydroaluminum, and sesquialkylhydroaluminum.

[0030] Ionic compounds have the general formula C+·A-, where C+ is an oxidizing cation of an organic, organometallic, or inorganic compound, or a Brønsted acid consisting of a Lewis base and a proton, which can react with the anion of the metallocene ligand to produce the metallocene cation.

[0031] As a method for copolymerizing butene with an olefin or copolymerizing ethylene with octene using a metallocene catalyst, various well-known methods can be used, such as fluidized bed gas phase polymerization or stirred gas phase polymerization in an inert gas, slurry polymerization in an inert solvent, and bulk polymerization using a monomer as a solvent.

[0032] As the adhesive, a known adhesive component capable of bonding the layers together can be used.

[0033] As the adhesive resin, a known adhesive resin capable of bonding the layers together can be used. Unsaturated carboxylic acid-grafted polyolefins can be obtained by grafting unsaturated carboxylic acids onto polyolefins using known methods. As the unsaturated carboxylic acid-grafted polyolefins, resin components containing or consisting of unsaturated carboxylic acid-grafted ethylene-α-olefin copolymers obtained by grafting or reacting unsaturated carboxylic acids onto ethylene-α-olefin copolymers can be used. As the unsaturated carboxylic acids, maleic acid, itaconic acid, citraconic acid, and anhydrides and monoesters thereof can be used. Unsaturated carboxylic acid-grafted polyolefins can be produced by grafting 0.01 to 5 parts by mass of unsaturated carboxylic acids onto 100 parts by mass of polyolefins.

[0034] There are no particular limitations on the method for producing the aquatic biofouling-inhibiting film of the present disclosure, and methods commonly used in the production of conventional multilayer films, such as inflation film molding and T-die film molding, can be used.

[0035] The aquatic biofouling inhibitor film of the present disclosure may contain additives such as lubricants, antiblocking agents, antioxidants, ultraviolet absorbers, heat stabilizers, flame retardants, inorganic or organic fillers, and antistatic agents, as needed. There are no particular limitations on the thickness, width, and length of the film. For example, the thickness of the film is about 1 to 100 μm, preferably 10 to 50 μm, more preferably 20 to 30 μm, and particularly preferably about 25 μm. The width of the film is about 1 to 2000 mm, preferably 100 to 1000 mm, more preferably 200 to 600 mm, and particularly preferably about 500 mm.

[0036] The aquatic organism adhesion-inhibiting film of the present disclosure can be referred to as an aquatic organism adhesion-inhibiting resin, an aquatic organism adhesion-inhibiting film, an aquatic organism adhesion-inhibiting material, an aquatic organism parasitism-inhibiting material, or the like. The type of aquatic organism is not particularly limited, and examples include shellfish such as barnacles and bivalves, crustaceans such as crabs and shrimp, and lugworms (a type of polychaete belonging to the phylum Annelida, class Polychaeta). "Attachment" can be rephrased as "contact" or "parasitism." "Suppression" can be rephrased as "prevention," "reduction," etc.

[0037] Floats coated with a film to prevent underwater biofouling A float coated with the aquatic biofouling-prevention film of the present disclosure (hereinafter sometimes referred to as "embodiment 1," "aquatic biofouling-prevention float," "aquatic biofouling-prevention float coated with aquatic biofouling-prevention film," etc.) has a float body coated with the aquatic biofouling-prevention film. The aquatic biofouling-prevention float may also have the aquatic biofouling-prevention film laminated on top of the float body. The film can be referred to as a sheet. In other words, the underwater biofouling-inhibiting float coated with the underwater biofouling-inhibiting film of the present disclosure includes a float body and the underwater biofouling-inhibiting film, and the entire surface of the float body is covered with the underwater biofouling-inhibiting film. Since the entire surface of the float body is covered with the film for inhibiting adhesion of aquatic organisms, a float covered with the film for inhibiting adhesion of aquatic organisms of the present disclosure can inhibit the adhesion of organisms such as barnacles, bivalves, and other shellfish, crabs, shrimp, and other crustaceans, and lugworms. An underwater biofouling-inhibiting float coated with an underwater biofouling-inhibiting film can be rephrased as a film-coated float, a film-coated underwater biofouling-inhibiting float, or the like.

[0038] The float body is not particularly limited, and any known float can be used, such as a cylindrical polystyrene foam float or a urethane foam float used in oyster rafts, aquaculture rafts, etc. The diameter of a typical float body is about 25 to 85 cm, its outer circumference is about 75 to 270 cm, and its length (height) is about 45 to 115 cm. However, the size of the float body is not limited to these. During the manufacturing process, polystyrene foam is purified by adding steam, causing it to expand approximately 50 to 80 times its original size. This causes polystyrene foam floats to absorb water. For example, a cylindrical polystyrene foam float body with a diameter of 680 mm and a height of 1,150 mm weighs approximately 6 kg, but can absorb up to 10 kg of water, bringing its weight to 16 kg. In this way, the polystyrene foam float body 10 absorbs a large amount of water, causing a deterioration in performance. The float coated with the aquatic organism adhesion inhibitor film of the present disclosure can solve this problem by covering the entire surface of the float body with the aquatic organism adhesion inhibitor film.

[0039] Float Products Furthermore, in order to improve waterproofness, etc., the entire surface of the aquatic organism adhesion suppression float coated with the aquatic organism adhesion suppression film, i.e., the entire surface of the aquatic organism adhesion suppression film covering the float body, can be covered with a waterproof protective cover (hereinafter referred to as a float cover). As shown in Figure 5, the float product of embodiment 2 of the present disclosure includes a float body 1, the aquatic organism adhesion suppression film 2, and a float cover 3, and the entire surface of the float body 1 is covered with the aquatic organism adhesion suppression film 2, and the entire surface of the aquatic organism adhesion suppression film 2 is covered with the float cover 3. The float body of the float product of the present disclosure, coated with a film for inhibiting adhesion of aquatic organisms, has the effect of inhibiting adhesion of aquatic organisms. Therefore, deterioration of the float body (such as holes or falling apart) is inhibited, so the float body can be horizontally recycled even after, for example, five years. Furthermore, since the float body of the float product of the present disclosure can be horizontally recycled even after five years, it can be estimated that the float product of the present disclosure can be used for 7 to 12 years or more.

[0040] Float Cover The float cover plays a role in waterproofing and preventing damage to the aquatic organism adhesion suppression float covered with the aquatic organism adhesion suppression film of embodiment 1 (a float in which the entire surface of the float body is covered with the aquatic organism adhesion suppression film). The float cover is not particularly limited, and examples thereof include commercially available polyethylene covers. Commercially available polyethylene covers include the PE cover (orange) manufactured by Marine Float Co., Ltd. (material: polyethylene sheet, one-sided laminated (50 microns, 14 pieces x 14 pieces), size: for #20 to #600); PE cover (black) made by Marine Float Co., Ltd. (Material: polyethylene sheet, single-sided laminated (40 microns, 14 pieces x 14 pieces), size: for #3000 to #400); Marine Float mesh cover (black) (material: polyethylene sheet, unlaminated, size: for #300-#400); Examples include polyethylene float covers (orange) manufactured by Keiyo Polyethylene Co., Ltd. (KEIYO Polyethylene E808, polyethylene (-(CH2-CH2)n-): 99% or more, additives: 1% or less, normal hexane (residual polymerization solvent): 0.05% or less, odor: odorless). The material of the float cover is not particularly limited, and examples thereof include polyethylene. The thickness of the float cover is not particularly limited, and is, for example, 10 μm to 100 mm, preferably 0.1 mm to 1 mm, and more preferably 0.25 mm to 0.5 mm. The surface of the float cover may be meshed. The color of the float cover is not particularly limited. For example, a float color may be determined in advance for each manager or owner of the float, and a float cover of a color corresponding to the manager or owner of the float may be used. Since the float cover covers the entire surface of the float coated with the aquatic organism adhesion suppression film, the color of the float cover becomes the color of the float. In this way, by linking the float to the manager or owner of the float and using a float cover of the same color as the float, the float can be easily identified.

[0041] In the present disclosure, a float cover can cover the surface of an aquatic biofouling-inhibiting float coated with an aquatic biofouling-inhibiting film. Examples of the shape of the float cover include a bag-like shape and a cylindrical shape. When the float cover is bag-like, the float coated with the aquatic biofouling-inhibiting film can be placed inside the bag of the float cover and then squeezed on one side to completely cover the float. When the float cover is cylindrical, the float coated with the aquatic biofouling-inhibiting film can be placed inside the bag of the float cover and then squeezed on both sides or one side to completely cover the float. By covering the entire surface of a float coated with a film for inhibiting adhesion of underwater organisms with a float cover, it is possible to inhibit crustaceans from adhering to the float coated with a film for inhibiting adhesion of underwater organisms, while maintaining the performance of the float body and preventing damage.

[0042] The float body, the aquatic biofouling-inhibiting float coated with the aquatic biofouling-inhibiting film, and the float product of the present disclosure may further include an information tag that stores individual identification information. 10, the float product of the third embodiment of the present disclosure includes a float body 1, the aquatic organism adhesion prevention film 2, a float cover 3, and an information tag 4 that stores individual identification information. In other words, the entire surface of the float body 1 is covered with the aquatic organism adhesion prevention film 2, and the entire surface of the aquatic organism adhesion prevention film 2 is covered with the float cover 3. 10 shows a float product including a float body 1, the aquatic organism adhesion prevention film 2, a float cover 3, and an information tag 4 storing individual identification information, but is not limited to these. For example, the information tag 4 may be attached to a float that is covered with the aquatic organism adhesion prevention film of embodiment 1, which does not include a float cover and includes the float body 1 and the aquatic organism adhesion prevention film 2.

[0043] Information Tags The information tag is not particularly limited as long as it is a memory unit that stores individual identification information, and examples include IC chips, IC tags, RF tags, RFID; barcode tags, QR Code (registered trademark) tags, and other two-dimensional tags. For example, an IC tag may be an electronic tag (IC tag) that includes an IC chip that stores individual identification information and an antenna that emits radio waves containing this identification information. Specific examples of IC tags include RFID tags and NFC tags. Types of IC tags include "passive tags," "active tags," and "semi-active tags." The individual information of the information tag 4 in which the float information is input can be read in a contactless manner. Float information includes product information about the float (size, product number, raw materials, etc.), the float's manufacturing date, the float's manufacturer, the float's seller, the float's purchaser, the float's first use date, the float's use location, the float's warranty expiration date (replacement time), the number of floats, information for the person who found the float, etc. In this embodiment, the information tag 4 is an IC tag. Even when dirty, an IC tag can read information more easily than other information tags such as barcode tags. For example, in this embodiment, the information tag 4 is an RFID tag with a long communication distance. In this case, information can be read from a longer distance. RFID tags are further divided into active types that transmit information radio waves and passive types that do not transmit information radio waves. In this embodiment, the information tag 1 is a passive RFID tag that does not have a power source. In this case, power saving can be achieved. Note that RFID tags with a short communication distance can also be used. The attachment position of the information tag 4 is not particularly limited. In Fig. 10, the information tag 4 is inserted inside the float body 1, but it may be attached to the surface of the float body 1. Furthermore, the number of information tags is not limited to one, and two or more may be attached.

[0044] The aquatic biofouling-inhibiting float coated with the aquatic biofouling-inhibiting film of the present disclosure may have a through-hole formed along the center line of the float body. In this case, a rope or the like can be passed through the through-hole, and this rope can be used to prevent the float coated with the aquatic biofouling-inhibiting film floating on the water surface from moving from a predetermined position. Furthermore, the outer surface of the aquatic organism adhesion-control float coated with the aquatic organism adhesion-control film of the present disclosure may be fastened with multiple belts, for example, two belts.

[0045] Method for manufacturing aquatic biofouling-preventing floats coated with aquatic biofouling-preventing film The method for producing an aquatic organism adhesion-inhibiting float coated with the aquatic organism adhesion-inhibiting film of the present disclosure varies depending on the length and weight of the float, but examples include a production method comprising the following steps. (1) A process of wrapping a film for inhibiting the adhesion of aquatic organisms around the float body vertically twice (90 degrees above and below), (2) The process of rolling the dough horizontally in a spiral shape twice (overlapping about 5 cm and rolling while rotating), and (3) The process of taping the end of the aquatic biofouling prevention film. The method of manufacturing an aquatic organism adhesion-inhibiting float coated with the aquatic organism adhesion-inhibiting film of the present disclosure can easily and efficiently coat the aquatic organism adhesion-inhibiting film onto the float body. The method for manufacturing a float coated with a film for inhibiting the adhesion of aquatic organisms is not particularly limited as long as the film for inhibiting the adhesion of aquatic organisms can be coated on the float body. For example, the manufacturing method is not limited to the above, and any method may be used as long as the float body is covered with a film for inhibiting the adhesion of aquatic organisms. For example, the film may be laminated on the surface of the float body. The film may also be referred to as a resin, a resin composition, or the like. The examples below describe examples in which a film containing a polybutene copolymer is used, but for example, a resin (resin composition) containing a polybutene copolymer may be coated or covered on the float.

[0046] Purpose The underwater biofouling-inhibiting floats and float products coated with the underwater biofouling-inhibiting film of the present disclosure can be used as buoyancy bodies (floats (also called ribs, joints, or floats)) for aquaculture rafts, fenders for ships, etc.

[0047] Management method The management method or management system disclosed herein can be used to manage production, sales, use, collection, treatment, recycling, etc. in a seamless manner. This will help solve the problems of marine plastic pollution and litter. Specifically, by inputting information into an information tag attached to the float body and setting an expiration date, an alert (warning) will be issued to notify the user when it is time to replace the float, allowing it to be replaced with a new float. The replaced used float can be processed into fine plastic particles by crushing or the like, or melted and converted into petroleum raw materials, or recycled into known plastic materials.

[0048] How to monitor spill floats The management method or management system disclosed herein can monitor floats that have washed away from rafts, etc. For example, GPS can be used to obtain location information for the washed away float. Furthermore, since the trajectory of the washed away float can be tracked, the washed away float can be efficiently recovered. Furthermore, the float can be returned to the manufacturer, purchaser, etc. based on various information entered into the information tag. This prevents the float from being damaged or left unused for a long period of time, thereby preventing the scattering of plastic, the generation or release of microplastics, etc.

[0049] Horizontal recycling method The horizontal recycling method disclosed herein includes a process of recovering floats coated with a film for inhibiting the adhesion of aquatic organisms. The recovered used products can be recycled and returned to the market as environmentally friendly products. Furthermore, by recycling these products again, the environment is protected as a sustainable cycle. This horizontal recycling method can be called Revive Our Setouchi. Specifically, the horizontal recycling method for floats includes the following embodiments.

[0050] Examples of the horizontal recycling method for the float according to this embodiment include the following horizontal recycling method 1 and horizontal recycling method 2.

[0051] Horizontal recycling method 1 includes, for example: A recovery step (S1) of recovering a used float coated with a film for inhibiting aquatic biofouling; A step (S2) of removing the float cover and the aquatic organism adhesion suppression film from the recovered used float coated with the aquatic organism adhesion suppression film, leaving only the float; a crushing step (S3) of crushing the floats into plastic flakes; A washing step (S4) of washing the plastic flakes during or after crushing in the crushing step; A drying step (S5) of drying the washed plastic flakes; A melting step (S6) of melting the dried plastic flakes to form a melt; The method may further include a molding step (S7) of molding the material containing the molten material into a plastic molded container (not shown).

[0052] In other words, horizontal recycling method 1 is a method for recycling or regenerating plastic molded containers (material recycling method or horizontal recycling method) in which used plastic molded containers are collected to form plastic flakes, which are recycled resin materials (recycled materials), and these plastic flakes are used to form plastic molded containers, which are recycled products (not shown).

[0053] In addition, as a horizontal recycling method 2, for example, A recovery step (S11) of recovering a used float coated with a film for inhibiting aquatic biofouling; A process (S12) of removing the float cover and the aquatic organism adhesion suppression film from the recovered used float coated with the aquatic organism adhesion suppression film, leaving only the float body; A step (S13) of cleaning the float body; a step (cutting step) (S14) of scraping off the surface of the cleaned float body; The method may further include a step (S15) of reusing the cut float body (not shown). [Example]

[0054] The present disclosure will be explained in more detail below using examples, but the technical scope of the present disclosure is not limited to these examples.

[0055] Example 1 The polystyrene foam float body (length 1150 mm, diameter 700 mm) was coated with the polybutene copolymer resin film of Example 1 (Tsukasa Chemical Industry Co., Ltd., Silage Film Morwrap, polybutene-olefin copolymer 10% or less, ethylene-octene copolymer (high density polyethylene) 90%, (C2H4)m-(C8H 16 )n, Form: Film, Color: White, Odor: Odorless, pH: Neutral, Melting point: 120°C, Decomposition temperature: 250°C or higher, Flash point: 350-400°C, Ignition point: 400°C or higher, Density: 0.88-0.98g / cm 3 The float body was wrapped in a polybutene copolymer resin film (solubility: none, presence or absence of hygroscopic material: none), and the float body was covered with a polybutene copolymer resin film. The float covered with the polybutene copolymer resin film was then covered with a commercially available polyethylene float cover (orange) (Keiyo Polyethylene Co., Ltd., KEIYO Polyethylene E808, polyethylene (-(CH-CH)-): 99% or more, additives: 1% or less, normal hexane (residual polymerization solvent): 0.05% or less, odor: odorless), to produce the float of Example 1 (see Figure 5).

[0056] Example 1 Instead of the polybutene copolymer resin film of Example 1, a linear low-density polyethylene (LLDPE) stretched film of Comparative Example 1 (Nozoe Sangyo Co., Ltd., product name: 3-, 5-, and 7-layer extruded linear low-density polyethylene (LLDPE) stretched film, physical state: solid, shape / color: transparent film, odor: odorless, density: 0.89 to 0.96 g / cm) was used. 3The float of Comparative Example 1 was produced in the same manner as in Example 1, except that the following compound was used: a polystyrene foam float body (length, height, diameter): 105°C to 135°C, melting point: 105°C to 135°C, flash point: >340°C (estimated), spontaneous ignition temperature: 260°C to 320°C, explosive limit (in air): not applicable, water solubility: insoluble, solubility in other solvents: high-temperature aromatic compounds). Specifically, the linear low-density polyethylene (LLDPE) film of Comparative Example 1 was wrapped around a polystyrene foam float body (length, height, diameter), and the float body was covered with the linear low-density polyethylene (LLDPE) film. The float covered with the linear low-density polyethylene (LLDPE) film was further covered with a commercially available polyethylene float cover (black), to produce the float of Comparative Example 1.

[0057] Example 2 The float of Comparative Example 2 was produced by covering the foam polystyrene float body (length, height, diameter) with a black polyethylene cover (see FIG. 3).

[0058] <Test example> Aquatic Biofouling Test The floats of Example 1, Comparative Example 1 and Comparative Example 2 were tested by floating them in the sea off Etajima, Hiroshima Prefecture for 60 months. Photographs of the float of Example 1 before the underwater biofouling test are shown in Figure 6. The photograph on the left is with the float cover, and the photograph on the right is of the float covered with a film. Photographs of the float of Comparative Example 1 before the underwater biofouling test are shown in Figure 6. The photograph on the left is with the float cover, and the photograph on the right is of the float covered with a film. Photographs of the float of Comparative Example 2 before use and before the underwater organism adhesion test are shown in Figure 6. The photograph on the left is with the float cover, and the photograph on the right is of the float itself (without being covered with a film).

[0059] (evaluation) The float covers and films were removed from the floats of Example 1 and Comparative Example 1. The float cover was removed from the float of Comparative Example 2. A photograph of the float of Example 1 after the aquatic organism adhesion test is shown in Figure 7. A photograph of the float body of Example 1 after the aquatic organism adhesion test, with the float cover and the aquatic organism adhesion suppression film removed, is shown in the photograph of the float body after use in Figure 6, and a photograph of the cross section of the float body is shown in Figure 8. A photograph of the float of Comparative Example 1 after the underwater organism adhesion test is shown in Figure 7. A photograph of the float body of Comparative Example 1 from which the float cover and comparative film have been removed after the underwater organism adhesion test is shown in Figure 7. A photograph of the float of Comparative Example 2 after the underwater organism adhesion test is shown in Figure 7. A photograph of the float body of Comparative Example 2 with the float cover removed after the underwater organism adhesion test is shown in Figure 7. The condition of each float body was visually evaluated by seven evaluators. After discussion among all evaluators, the condition was evaluated using the following five-point scale. The results are shown in Table 1.

[0060] (5 levels) 5: The float body is in a reusable condition (horizontal recycling is possible). The float body is in a clean condition. 4: The float body can be reused (horizontally recycled), the float body is a little dirty. 3: The float body is in a state where it is difficult to reuse (horizontal recycling may be difficult). The float body has a few holes that could be habitats for aquatic organisms. 2: The float body is in a state where it is difficult to reuse (horizontal recycling is difficult). The float body has holes that are habitats for aquatic organisms, and the state is somewhere between 3 above and 1 below. 1: The float itself is difficult to reuse (horizontal recycling is difficult). The float itself has many holes that are habitats for aquatic life, and the polystyrene foam peels off when you touch it with your hand. Horizontal recycling, also known as horizontal circulation or horizontal reuse, refers to recovering a product after use and recycling it into the same type of product or material as the original product. Specifically, a float coated with an aquatic biofouling prevention film according to the present disclosure can be horizontally recycled by scraping or removing the surface of the float after use.

[0061] [Table 1]

[0062] result When the aquatic biofouling inhibition film (polybutene copolymer) of Example 1 was used, the float body after the test was in a state that allowed it to be reused (horizontally recycled) (as shown in the photograph after use in Figure 7), and its cross section was also clean, as shown in Figure 8. In contrast, when the film of Comparative Example 1 (linear low-density polyethylene (LLDPE)) was used, the float body after the test was not in a state suitable for reuse (horizontal recycling) (as shown in the photograph of the float after use in Figure 7). In addition, in the case of Comparative Example 2, in which the float body was directly covered with the float cover without using a film, the float body after the test was not in a condition suitable for reuse (horizontal recycling) (as shown in the photograph of the float body after use in Figure 7). As described above, after five years of use, the float coated with the aquatic organism adhesion-inhibiting film of the present disclosure had almost no holes in the float body caused by aquatic organisms, and maintained its shape as a buoyant body to the extent that it could be reused. [Explanation of symbols]

[0063] 1 Float body 2. Film for preventing aquatic biofouling 3 Float Cover 4 Information Tags C cross section 1 D cross section 2

Claims

1. A film for inhibiting the adhesion of aquatic organisms, comprising a polybutene-olefin copolymer and an ethylene-octene copolymer.

2. A float having a float body covered with the film for inhibiting adhesion of aquatic organisms according to claim 1.

3. A float product comprising: a float coated with the aquatic organism adhesion prevention film according to claim 2; and a float cover that covers the float coated with the aquatic organism adhesion prevention film.

4. 3. The float coated with the film for inhibiting adhesion of aquatic organisms according to claim 2, further comprising an information tag storing individual identification information.

5. 5. The float coated with a film for inhibiting the adhesion of aquatic organisms according to claim 4, wherein the information tag includes an IC chip.

6. A method for horizontally recycling floats, comprising a step of recovering floats coated with the aquatic organism adhesion suppression film according to claim 2.

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