Biodegradable buoy and method of manufacturing the same

Abstract

The present invention provides a biodegradable buoy characterized by being formed from a buoy-forming composition comprising a biodegradable polymer. The biodegradable buoy according to the present invention utilizes a biodegradable polymer to exhibit excellent biodegradability, making it suitable for use as a marine buoy. Furthermore, by biodegrading after use, it prevents the generation of microplastics and contributes to the protection of the marine ecosystem. Additionally, excellent buoyancy and mechanical strength are simultaneously achieved through an optimal mixing ratio of the biodegradable polymer and calcium carbonate.

Description

Technology Field

[0001] The present invention relates to a biodegradable buoy and a method for manufacturing the same. Background Technology

[0002] Conventional buoys used in marine aquaculture farms are mainly manufactured from styrofoam (expanded polystyrene) or general plastic materials. The number of fishing buoys used in Korea amounts to approximately 55 million, of which styrofoam buoys account for about 72%.

[0003] These styrofoam buoys are easily damaged by waves or impacts, and when they break, they release large amounts of microplastics, becoming a major cause of marine environmental pollution. It has been found that approximately 55% of the plastic waste observed on the Korean coast consists of styrofoam buoys, and microplastics serve as food for marine organisms, having an adverse effect on the entire ecosystem.

[0004] Accordingly, the Ministry of Oceans and Fisheries has completely banned the use of styrofoam buoys starting in November 2023 and mandated the use of eco-friendly buoys, creating an urgent need for the development of biodegradable buoys that are both eco-friendly and practical. Prior art literature

[0005] Republic of Korea Registered Patent No. 10-2219616 The problem to be solved

[0006] The object of the present invention is to provide a biodegradable buoy and a method for manufacturing the same.

[0007] The problems of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0008] To achieve the above objective, the present invention

[0009] The present invention provides a biodegradable buoy characterized by being formed from a composition for forming a buoy that includes a biodegradable polymer.

[0010] In addition, the above-mentioned biodegradable polymer is characterized by being one or more selected from the group consisting of polybutylene adipate terephthalate (PBAT), polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone (PCL), thermoplastic starch (TPS), and polyhydroxyalkanoate (PHA).

[0011] In addition, the composition for forming the buoy comprises 30-50 parts by weight of a biodegradable polymer and 50-70 parts by weight of calcium carbonate.

[0012] In addition, the composition for forming the buoy comprises 35-45 parts by weight of polybutylene adipate terephthalate (PBAT), 20-40 parts by weight of calcium carbonate with an average particle size of 0.1-2.0 μm, 10-30 parts by weight of calcium carbonate with an average particle size of 5.0-10.0 μm, and 5-15 parts by weight of calcium carbonate with an average particle size of 20.0-50.0 μm.

[0013] In addition, the above-mentioned composition for forming a buoy further comprises 1 to 15 parts by weight of a reinforcing additive, and

[0014] The above reinforcing additive is,

[0015] A step of preparing a mixture by mixing 73-77 parts by weight of 1,3-propanediol and 23-27 parts by weight of erythritol; a step of preparing a mixture by adding 54-58 parts by weight of the mixture, 20-24 parts by weight of succinic acid, and 20-24 parts by weight of azelaic acid to an esterification reactor and mixing them; a step of adding titanium (IV) acetylacetonate to the mixture and performing an esterification reaction at a temperature of 258-262°C for 1-3 hours; and a step of, after performing the esterification reaction, transferring the reaction product to a polycondensation reactor and performing a polycondensation reaction in the polycondensation reactor at a temperature of 283-287°C for 3-5 hours; comprising a step of preparing a polyester resin.

[0016] A step of preparing a pellet composition by mixing 68-72 parts by weight of the above polyester resin, 13-17 parts by weight of nanocellulose fiber, 8-12 parts by weight of calcium carbonate, 0.8-1.2 parts by weight of 3-methoxypropyltrimethoxysilane, 1-5 parts by weight of N,N′-methylenebis(acrylamide), and 0.8-1.2 parts by weight of polyethylene glycol, and preparing a pellet composition by processing the above pellet composition; and

[0017] It is characterized by being manufactured by performing the step of fiberizing the above pellets.

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[0026] In addition, the present invention

[0027] A method for manufacturing a biodegradable buoy using a buoy-forming composition is provided.

[0028] In addition, the present invention

[0029] A biodegradable resin composition comprising 30-50 parts by weight of a biodegradable polymer and 50-70 parts by weight of calcium carbonate is provided. Effects of the invention

[0030] The biodegradable buoy according to the present invention utilizes a biodegradable polymer and exhibits excellent biodegradability, making it suitable for use as a marine buoy. Furthermore, by biodegrading after use, it prevents the generation of microplastics and contributes to the protection of the marine ecosystem. Additionally, excellent buoyancy and mechanical strength are simultaneously achieved through an optimal mixing ratio of the biodegradable polymer and calcium carbonate. Specific details for implementing the invention

[0031] Various embodiments are described in more detail below. The embodiments described herein may be modified in various ways. Specific embodiments may be described in detail in the detailed description. However, the specific embodiments disclosed are intended only to facilitate understanding of various embodiments. Accordingly, the technical concept is not limited by the specific embodiments disclosed, and it should be understood that it includes all equivalents or substitutions that fall within the spirit and scope of the invention.

[0032] Terms including ordinal numbers, such as first, second, first, second, etc., may be used to describe various components, but these components are not limited by the aforementioned terms. The aforementioned terms are used solely for the purpose of distinguishing one component from another.

[0033] In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. When a component is described as being "connected" or "connected" to another component, it should be understood that it may be directly connected to or connected to that other component, or that there may be other components in between. On the other hand, when a component is described as being "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0034] Furthermore, in describing the present invention, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the essence of the invention, such detailed description is abbreviated or omitted.

[0035] The present invention

[0036] The present invention provides a biodegradable buoy characterized by being formed from a composition for forming a buoy that includes a biodegradable polymer.

[0037] Hereinafter, the biodegradable buoy according to the present invention will be described in detail.

[0039] The biodegradable polymer used in the present invention is a polymer that can be degraded by microorganisms in a marine environment, and may include polybutylene adipate terephthalate (PBAT), polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone (PCL), thermoplastic starch (TPS), and polyhydroxyalkanoate (PHA). As a preferred example, polybutylene adipate terephthalate (PBAT) is used.

[0040] The above polybutylene adipate terephthalate (PBAT) is a biodegradable polymer with excellent ductility and high elongation at break, and can exhibit high durability.

[0041] Additionally, the composition for forming the buoy may include 30-50 parts by weight of a biodegradable polymer and 50-70 parts by weight of calcium carbonate, 35-45 parts by weight of a biodegradable polymer and 55-65 parts by weight of calcium carbonate, or 38-42 parts by weight of a biodegradable polymer and 58-62 parts by weight of calcium carbonate. If the content of calcium carbonate is less than 50 parts by weight, the effect of reducing raw material costs and improving buoyancy is insufficient, and if it exceeds 70 parts by weight, the content of the biodegradable polymer is relatively insufficient, resulting in reduced mechanical strength and poor moldability.

[0042] In addition, it is more preferable that the composition for forming the buoy comprises 35-45 parts by weight of polybutylene adipate terephthalate (PBAT), 20-40 parts by weight of calcium carbonate with an average particle size of 0.1-2.0 μm, 10-30 parts by weight of calcium carbonate with an average particle size of 5.0-10.0 μm, and 5-15 parts by weight of calcium carbonate with an average particle size of 20.0-50.0 μm. A composition having such compositional ratios and particle size distribution allows calcium carbonate particles of various size ranges to be dispersed in a stepped manner within a PBAT matrix, thereby simultaneously securing mechanical strength and impact resistance through mutual complementary effects between particles. In particular, ultrafine calcium carbonate with an average particle size of 0.1-2.0 μm significantly improves the crystallinity and tensile strength of PBAT, particles of 5.0-10.0 μm are responsible for dispersion uniformity and molding stability, and particles of 20.0-50.0 μm contribute to controlling the buoyancy and density of the buoy, thereby optimizing the balance of physical properties of the final buoy.

[0043] In addition, by maintaining a specific range through 35-45 parts by weight of PBAT and a distribution of calcium carbonate according to average particle size (20-40 parts by weight, 10-30 parts by weight, and 5-15 parts by weight), it is possible to secure a decomposition rate that simultaneously satisfies biodegradability in a marine environment and durability for use in aquaculture farms for several years. If the PBAT content decreases or the proportion of ultrafine and fine calcium carbonate becomes excessively high outside the above range, sufficient mechanical strength may not be secured, or conversely, if the proportion of coarse calcium carbonate becomes excessively high, the density may increase excessively, leading to a decrease in buoyancy.

[0044] In addition, the composition for forming the buoy may further include 1-15 parts by weight of a reinforcing additive, 3-12 parts by weight, and 5-12 parts by weight.

[0045] The above reinforcing additive is,

[0046] A step of preparing a mixture by mixing 73-77 parts by weight of 1,3-propanediol and 23-27 parts by weight of erythritol; a step of preparing a mixture by adding 54-58 parts by weight of the mixture, 20-24 parts by weight of succinic acid, and 20-24 parts by weight of azelaic acid to an esterification reactor and mixing them; a step of adding titanium (IV) acetylacetonate to the mixture and performing an esterification reaction at a temperature of 258-262°C for 1-3 hours; and a step of, after performing the esterification reaction, transferring the reaction product to a polycondensation reactor and performing a polycondensation reaction in the polycondensation reactor at a temperature of 283-287°C for 3-5 hours; comprising a step of preparing a polyester resin.

[0047] A step of preparing a pellet composition by mixing 68-72 parts by weight of the above polyester resin, 13-17 parts by weight of nanocellulose fiber, 8-12 parts by weight of calcium carbonate, 0.8-1.2 parts by weight of 3-methoxypropyltrimethoxysilane, 1-5 parts by weight of N,N′-methylenebis(acrylamide), and 0.8-1.2 parts by weight of polyethylene glycol, and preparing a pellet composition by processing the above pellet composition; and

[0048] The above pellet is applied to be manufactured by performing the step of fiberizing it.

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[0056] The biodegradable buoy according to the present invention can have even better mechanical properties by applying the reinforcing additive.

[0058] In addition, the present invention

[0059] A method for manufacturing a biodegradable buoy using a buoy-forming composition is provided.

[0060] The method for manufacturing the above-mentioned biodegradable buoy is,

[0061] A raw material composition is prepared with the components and content of the composition presented above, the raw material composition is fed into an extrusion molding machine equipped with a twin-screw, kneaded at a temperature of 145-165°C to pelletize, and biodegradable pellets are prepared, the biodegradable pellets are melted at a temperature of 200-220°C and poured into a mold at a pressure of 1-10 kgf / cm² 2 It can be manufactured by blowing with pressure and cooling for 10-30 seconds.

[0062] In addition, the present invention

[0063] A biodegradable resin composition comprising 30-50 parts by weight of a biodegradable polymer and 50-70 parts by weight of calcium carbonate is provided.

[0064] The biodegradable buoy according to the present invention utilizes a biodegradable polymer and exhibits excellent biodegradability, making it suitable for use as a marine buoy. Furthermore, by biodegrading after use, it prevents the generation of microplastics and contributes to the protection of the marine ecosystem. Additionally, excellent buoyancy and mechanical strength are simultaneously achieved through an optimal mixing ratio of the biodegradable polymer and calcium carbonate.

[0066] The present invention will be explained in more detail below by the following examples.

[0067] However, the following examples are merely illustrative of the content of the invention, and the scope of the invention is not limited by the examples and experimental examples.

[0068] <Example> Preparation of Biodegradable Buoy

[0069] A raw material composition is prepared with the components and content shown in Table 1 below, said raw material composition is fed into an extrusion molding machine equipped with a twin-screw, kneaded at a temperature of 155°C to pelletize, and biodegradable pellets are prepared, said biodegradable pellets are melted at a temperature of 210°C and in a mold at 5 kgf / cm² 2 A biodegradable buoy was manufactured by blowing with pressure and cooling for 20 seconds.

[0070] Example 1 Example 2 Example 3 Example 4 PBAT 40 40 40 40 Calcium carbonate 1 - - 30 30 Calcium carbonate 2 - 30 20 20 Calcium carbonate 3 60 30 10 10 Fortification additive - - - 10

[0071] * Calcium carbonate 1 : Calcium carbonate with an average particle size of 0.5-1.0 µm

[0072] * Calcium carbonate 2: Calcium carbonate with an average particle size of 7-9 µm

[0073] * Calcium carbonate 3: Calcium carbonate with an average particle size of 35-45 µm

[0074] <Experimental Example> Analysis of Biodegradable Buoy Characteristics

[0075] The characteristics of the biodegradable buoys prepared in Examples 1-4 above were analyzed through the following experiments.

[0076] Each of the above compositions was prepared into flakes with a thickness of 300 μm and a size of 30 mm × 30 mm, and the initial number average molecular weight of the flakes was measured under the following gel permeation chromatography (GPC) equipment and measurement conditions. Subsequently, each flake was placed for 63 days under the following composting conditions, a temperature of 60°C and a humidity of 90%, after which the number average molecular weight was measured under the following gel permeation chromatography (GPC) equipment and measurement conditions. The difference between the initial number average molecular weight and the number average molecular weight after 63 days was divided by the initial number average molecular weight to derive the biodegradability, and the results are shown in Table 1 below.

[0077] - Equipment and Measurement Conditions for Gel Permeation Chromatography (GPC)

[0078] Sample pretreatment: Dissolve 0.035 mg of the above-prepared flakes in 1.5 ml of THF.

[0079] Measuring device: waters, e2695

[0080] Infusion rate (Flow rate): 1 ml / min in the above THF

[0081] Injection volume: 50 µl

[0082] Column Temperature: 40℃

[0083] Detector: ELSD

[0084] Column: Styragel Column HR 5E, HR4, HR2

[0085] - Compost conditions

[0086] Manufacturer: Taeheung F&G

[0087] Product Name: Jisaengto (Grade 1 By-product Fertilizer Compost)

[0088] Compost composition: Pig manure 40 wt%, chicken manure 15 wt%, sawdust 37 wt%, zeolite 5 wt%, microbial agent 3 wt%

[0089] In addition, using the pellets prepared in Examples 1-4 above, tensile strength and elongation were analyzed using the ASTM D638 test method, flexural strength and flexural modulus were analyzed using the ASTM D790 test method, and room temperature IZOD impact strength was analyzed using the ASTM D256 test method, and the results are shown in Table 2 below.

[0090] Example 1 Example 2 Example 3 Example 4 Biodegradability (%) 93 93 93 91 Tensile strength (MPa) 30.6 31.7 35.3 42.0 Growth Rate (%) 201.5 200.0 223.7 243.2 Flexural strength (MPa) 35.4 36.8 40.5 44.3 Flexural modulus (MPa) 1237 1289 1325 1368 IZOD Impact Strength (J / m) 868.5 879.4 942.3 974.5

[0091] As shown in Table 2 above, it was confirmed that the biodegradable buoy according to the present invention exhibits excellent biodegradability and excellent mechanical properties.

Claims

Claim 1 A method comprising 35-45 parts by weight of polybutylene adipate terephthalate (PBAT), 1-15 parts by weight of a reinforcing additive, 20-40 parts by weight of calcium carbonate having an average particle size of 0.1-2.0 μm, 10-30 parts by weight of calcium carbonate having an average particle size of 5.0-10.0 μm, and 5-15 parts by weight of calcium carbonate having an average particle size of 20.0-50.0 μm, wherein the reinforcing additive comprises the steps of: preparing a mixture by mixing 73-77 parts by weight of 1,3-propanediol and 23-27 parts by weight of erythritol; and preparing a mixture by adding 54-58 parts by weight of the mixture, 20-24 parts by weight of succinic acid, and 20-24 parts by weight of azelaic acid to an esterification reactor and mixing. A step of preparing a polyester resin comprising: adding titanium (IV) acetylacetonate to the above mixture and performing an esterification reaction at a temperature of 258-262°C for 1-3 hours; and, after performing the esterification reaction, transferring the reaction product to a polycondensation reactor and performing a polycondensation reaction in the polycondensation reactor at a temperature of 283-287°C for 3-5 hours; and a step of preparing a pellet composition by mixing 68-72 parts by weight of the polyester resin, 13-17 parts by weight of nanocellulose fiber, 8-12 parts by weight of calcium carbonate, 0.8-1.2 parts by weight of 3-methoxypropyltrimethoxysilane, 1-5 parts by weight of N,N′-methylenebis(acrylamide), and 0.8-1.2 parts by weight of polyethylene glycol, and processing the pellet composition to produce pellets. A biodegradable buoy characterized by being manufactured by performing the step of fiberizing the above pellets. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete