Marine biodegradable resin composition and degradation speed accelerator

Abstract

To provide a technique for accelerating marine biodegradation speed of a biodegradable resin.SOLUTION: A marine biodegradation speed accelerator of a biodegradable resin contains one or more kinds selected from a monomer composed of a 9,10,16-trihydroxy hexadecanoic acid or its analog, an oligomer containing the monomer, and a polymer containing the monomer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a marine biodegradation rate accelerator for biodegradable resins that utilizes 9,10,16-trihydroxyhexadecanoic acid (also known as aroiritic acid) and the like, and to a marine biodegradable resin composition containing the same. [Background technology]

[0002] Polybutylene succinate-co-adipate (PBSA) and polybutylene succinate (PBS) Many aliphatic polyesters, such as these, are biodegradable materials with excellent physical properties and processability. However, their low biodegradation rate in the ocean contributes to marine environmental pollution. Attempts have been made to improve the decomposition rate by adding decomposition accelerators, but this has not been sufficient in terms of achieving both high biodegradation rate and other physical properties (such as a decrease in tensile strength due to the addition of accelerators) and material costs. Further marine biodegradation technology is needed to meet the demand for diverse resin products.

[0003] Patent documents 1 to 3 describe the use of polyolefins with high marine biodegradability in materials such as PBSA and PBS, which have low marine biodegradability. Patent documents 4 and 5 disclose a method of increasing the decomposition rate by adding a hydrolytic enzyme to the resin. Patent document 6 discloses a method of increasing the decomposition rate by adding a nitrogen compound and a phosphorus compound. One method is to add chlorine to the mixture to increase the rate of decomposition in the marine environment. However, there is a need to develop further methods to accelerate the decomposition of biodegradable resins in the marine environment. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-145600 [Patent Document 2] Japanese Patent Publication No. 2022-037049 [Patent Document 3] Japanese Patent Publication No. 2022-172526 [Patent Document 4] Special Publication No. 2020-531671 [Patent Document 5] Special Publication No. 2022-526344 [Patent Document 6] JP 2022-142016 A (Patent No. 6976540) Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above circumstances, an object of the present invention is to develop a technology for accelerating the rate of marine biodegradation of biodegradable resins. [Means for solving the problem]

[0006] As a result of intensive research aimed at solving the above problems, the present inventors have found that compounds such as 9,10,16-trihydroxyhexadecanoic acid can accelerate the rate of marine biodegradation of biodegradable resins. Based on this finding, the present invention has been completed. That is, the gist of the present invention relates to the following.

[0007] [1] A marine biodegradation rate accelerator for biodegradable resins, comprising at least one selected from the group consisting of a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing said monomer, and a polymer containing said monomer. [2] The monomers are 9,10,16-trihydroxyhexadecanoic acid, 7,16-dihydroxyhexadecanoic acid, Decanoic acid, 8,16-dihydroxyhexadecanoic acid, 9,16-dihydroxyhexadecanoic acid, 10,16-dihydroxyhexadecanoic acid, (Z)-16-hydroxyhexadec-9-enoic acid, 9,10-epoxy 16-hydroxyhexadecanoic acid, 9,18-dihydroxyoctadecanoic acid, 10,18-dihydro (Z)-18-Hydroxyoctadecanoic acid, (Z)-18-hydroxyoctadec-9-enoic acid, 9,10-epoxy-18-hydroxy 9,10,18-trihydroxyoctadecanoic acid, (Z)-octadec-9-enoic acid Dienoic acid, (9Z,12Z)-18-hydroxyoctadeca-9,12-dienoic acid, (Z)-9,10-epoxy-18-hydroxybenzoic acid The marine biodegradation rate enhancer is selected from the group consisting of (6Z,9Z)-octadeca-6,9-dienedioic acid, (Z)-9,10,18-trihydroxyoctadec-12-enoic acid, (Z)-9,10,18-trihydroxyoctadec-12-enoic acid, and (6Z,9Z)-octadeca-6,9-dienedioic acid. [3] The marine biodegradation rate accelerator, wherein the biodegradable resin is a polyester resin. [4] The marine biodegradation rate accelerator, wherein the biodegradable resin is at least one selected from polybutylene succinate adipate and polybutylene succinate. [5] biodegradable resins, and The marine biodegradation rate accelerator, A marine biodegradable resin composition having an accelerated marine biodegradation rate, comprising: [6] A molded article formed from the marine biodegradable resin composition. [7] A method for accelerating the biodegradation rate of a biodegradable resin in a marine environment, comprising contacting the biodegradable resin with the marine biodegradation rate accelerator. [8] A method for biodegrading a biodegradable resin in a marine environment, comprising contacting the biodegradable resin with the marine biodegradation rate accelerator.

[0008] The present invention can also employ the following configuration.

[10] The use of one or more members selected from a monomer comprising 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing said monomer, and a polymer containing said monomer, for accelerating the rate of marine biodegradation of a biodegradable resin.

[11] 1. One or more members selected from a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing said monomer, and a polymer containing said monomer, for use in accelerating the marine biodegradation rate of a biodegradable resin.

[12] 1. Use of one or more members selected from a monomer comprising 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing said monomer, and a polymer containing said monomer, for the production of an agent for promoting the marine biodegradation rate of a biodegradable resin.

[13] A method for producing a marine biodegradation rate accelerator for biodegradable resins, comprising formulating one or more selected from a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing said monomer, and a polymer containing said monomer.

[14] A method for producing a marine biodegradable resin composition with an accelerated rate of marine biodegradation, comprising mixing a biodegradable resin composition with one or more selected from a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing said monomer, and a polymer containing said monomer. [Effects of the Invention]

[0009] According to the present invention, the marine biodegradation rate of a biodegradable resin can be accelerated. That is, the present invention provides an accelerator for the marine biodegradation rate of a biodegradable resin, a marine biodegradable resin composition having an accelerated marine biodegradation rate, a molded article formed from the marine biodegradable resin composition, a method for accelerating the biodegradation rate of a biodegradable resin in a marine environment, a method for biodegrading a biodegradable resin in a marine environment, etc.

[0010] That is, according to the present invention, by coexisting a biodegradable resin with a low rate of marine biodegradation with a compound such as 9,10,16-trihydroxyhexadecanoic acid, the rate of marine biodegradation of the biodegradable resin can be accelerated. As a result, it is possible to provide, at low cost, a composite material that maintains its mechanical properties under normal use conditions but exhibits accelerated biodegradability when released into the environment after use and placed in an environment with few microorganisms, such as the ocean. [Brief explanation of the drawings]

[0011] [Figure 1] Figure 1 shows the weight loss rates of PBSA, PBSA + 10% AA, PBS, and PBS + 10% AA films after immersion in a seawater bath at 20°C for 1 month and 2 months. [Figure 2] Figure 2 shows the weight loss rates of PBSA, PBSA + 10% AA, PBS, and PBS + 10% AA films after immersion in sterile artificial seawater at 20°C for 1 month and 2 months. [Figure 3] Figure 3 shows PBS, PBSA, and the blend film before and after immersion in a seawater tank at 20°C for 1 month and 2 months (photos used as drawing substitutes). The black bar indicates 1 cm. [Figure 4] Figure 4 shows the PBS, PBSA, and blend films before and after immersion in sterile artificial seawater at 20°C for one and two months (photos used as drawing substitutes). The black bar indicates 0.5 cm. [Figure 5] Figure 5 shows SEM images of PBSA and PBSA + 10% AA films, from which biofilms had been removed by washing, before and after immersion in a seawater tank for one and two months (photographs used as drawing substitutes). The white bar indicates 10 μm. [Figure 6] Figure 6 shows SEM images of PBS and PBS + 10% AA films, from which biofilms had been removed by washing, before and after immersion in a seawater tank for one and two months (photographs used as drawing substitutes). The white bar indicates 10 μm. [Figure 7] Figure 7 shows SEM images of biofilms on PBSA and PBSA + 10% AA films before and after immersion in a seawater tank for 1 and 2 months (photographs used as drawing substitutes). The white bar indicates 10 μm. [Figure 8] Figure 8 shows SEM images of biofilms in PBS and PBS + 10% AA film before and after immersion in seawater for 1 month and 2 months (photographs used as drawing substitutes). The white bar indicates 10 μm. [Figure 9] Figure 9 shows SEM images of PBSA and PBSA + 10% AA films before and after immersion in sterilized artificial seawater for one and two months (photographs used as drawing substitutes). The white bar indicates 10 μm. [Figure 10] Figure 10 shows SEM images of PBS and PBS + 10% AA films before and after immersion in sterilized artificial seawater for one and two months (photographs used as drawing substitutes). The white bar indicates 10 μm. [Figure 11] Figure 11 shows the DNA concentration of each sample after immersion in a seawater tank for 1 month and 2 months. [Figure 12] FIG. 12 shows the RNA concentration of each sample immersed in a seawater tank for 1 month and 2 months. [Figure 13] FIG. 13 shows the BOD biodegradation curves of each sample. [Figure 14] FIG. 14 shows the molecular weight distribution curves of PBSA and PBSA+10% AA. [Figure 15] FIG. 15 shows the molecular weight distribution curves of PBS and PBS+10% AA. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below. <Marine biodegradation rate accelerator> One aspect of the present invention is a marine biodegradation rate accelerator for biodegradable resins (hereinafter referred to as "the marine biodegradable resin of the present invention"), which comprises at least one selected from the group consisting of a monomer comprising 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing the monomer, and a polymer containing the monomer. (sometimes referred to as "speed enhancers").

[0013] In the present invention, the biodegradation rate of a biodegradable resin in a marine environment such as seawater or the ocean can be accelerated by contacting the biodegradable resin with one or more selected from a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing the monomer, and a polymer containing the monomer. The marine biodegradation rate accelerator of the present invention can accelerate the biodegradation rate of a biodegradable resin in a marine environment by contacting the biodegradable resin with the marine biodegradation rate accelerator of the present invention, for example, by mixing the marine biodegradation rate accelerator of the present invention with the biodegradable resin or by laminating the marine biodegradation rate accelerator of the present invention on the biodegradable resin. For methods of using the marine biodegradation rate accelerator of the present invention, such as the method of contacting the marine biodegradation rate accelerator of the present invention with the biodegradable resin and the amount used, please refer to the items explained below in the sections <Marine biodegradable resin composition>, <Molded article>, and <Method for accelerating the biodegradation rate and biodegradation method>.

[0014] ≪Biodegradable resin≫ The "biodegradable resin" that is the target substance for accelerating the marine biodegradation rate of the marine biodegradation rate accelerator of the present invention is not particularly limited as long as it is a polymer that can be biodegraded by biodegradable polymer-degrading bacteria. Biodegradable resins include those derived from living organisms and those derived from chemical synthesis, and either can be used. Biodegradable resins include, but are not limited to, polyester resins, natural polymers and their derivatives, etc. Polyester resins can be selected from, for example, aliphatic polyesters, aromatic polyesters, etc.; natural polymers can be selected from, for example, cellulose, starch, etc.; and derivatives of natural polymers can be selected from, for example, cellulose esters, cellulose ethers, cellulose ether esters, etc.

[0015] The aliphatic polyester may be, for example, polylactic acid (PLA), polyhydroxyalkanoic acid (PHA), polyethylene succinate (PES), polybutylene succinate (PBS), polyethylene succinate adipate (PESA), polybutylene succinate adipate (PBSA), polycaprolactone (PCL), polybutylene succinate carbonate (PEC), polylactic acid / polycaprolactone copolymer, polylactic acid / polyether copolymer, or the like.

[0016] The aromatic polyester may be, for example, polybutylene adipate terephthalate (PBAT), polytetramethylene adipate terephthalate, polyethylene terephthalate succinate (PETS), and the like.

[0017] Polyhydroxyalkanoic acid (PHA) is, for example, a polyhydroxyalkanoic acid containing 3-hydroxyalkanoate. The poly-3-hydroxyalkanoate resin may be, specifically, a 3-hydroxyalkanoate resin. The resin may be a poly-3-hydroxybutyrate (PHB)-based resin containing butylate, specifically, poly-3-hydroxybutyrate (PHB), poly(3-hydroxybutyrate / 3-hydroxyvalerate) (PHBV), poly(3-hydroxybutyrate / 3-hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate / 4-hydroxybutyrate), etc.

[0018] Examples of cellulose esters include cellulose acetate, cellulose acetate propionate, and cellulose acetate butyrate; examples of cellulose ethers include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and cyanoethyl cellulose; and examples of cellulose ether esters include hydroxypropyl methyl cellulose acetate and hydroxypropyl methyl cellulose acetate succinate (it is intended that in this specification, cellulose ether esters are encompassed within the concepts of both cellulose ether and cellulose ester).

[0019] Although not limited thereto, among these, polyester resins are preferred, aliphatic polyester resins are more preferred, polyethylene succinate, polybutylene succinate, polyethylene succinate adipate, and polybutylene succinate adipate are even more preferred, and polybutylene succinate and polybutylene succinate adipate are particularly preferred. The biodegradable resin may contain one type or two or more types. The biodegradable resin can be prepared by, for example, a conventional method for preparing polymers, and commercially available products can also be used.

[0020] The molecular weight of the biodegradable resin used in the present invention is not particularly limited as long as it does not impair the effects of the present invention. For example, the number average molecular weight (Mn) may be 20,000 to 10,000,000. The weight average molecular weight (Mw) may be 20,000 to 10,000,000. The molecular weight can be measured by gel permeation chromatography (GPC) or the like.

[0021] Here, the biodegradability of a biodegradable resin means that the biodegradable resin has the property of being cut and fragmented into low molecular weight compounds by the action of hydrolytic enzymes and the like of biodegradable polymer-degrading bacteria, and then becomes inorganic. The biodegradability of a biodegradable resin in a marine environment (marine biodegradability) can be confirmed, for example, by immersing a sample in seawater and observing the weight loss from the initial weight after the seawater immersion test, as well as by measuring the biochemical oxygen demand (BOD) during the test.

[0022] <Monomer composed of 9,10,16-trihydroxyhexadecanoic acid or its analog, oligomer containing the monomer, and polymer containing the monomer> The marine biodegradation rate accelerator of the present invention contains, as an active ingredient, one or more selected from a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing the monomer, and a polymer containing the monomer.

[0023] 9,10,16-trihydroxyhexadecanoic acid, which is a preferred embodiment of the active ingredient, is an omega-hydroxy acid known as one of the monomers that make up cutin. Cutin is a waxy substance that covers the surface of plants and is one of the main polymers that make up the cuticle. Cutin is composed of omega-hydroxy acids and their derivatives, which are linked together via ester bonds to form polyester polymers.

[0024] Here, an omega hydroxy acid (ω-hydroxy acid) is a compound having a hydrocarbon chain of n carbon atoms with a carboxy group at position 1 and a hydroxy group at the terminal position.

[0025] The analogue of 9,10,16-trihydroxyhexadecanoic acid can be any substance that accelerates the marine biodegradation rate of biodegradable resins. Examples of the analogue of 9,10,16-trihydroxyhexadecanoic acid include omega-hydroxybenzoates having 3 to 20 or 16 to 18 carbon atoms. The hydrocarbon chain constituting the omega hydroxy acid may be saturated or unsaturated, but is preferably a saturated hydrocarbon. The number of hydroxy groups may be, for example, 1 to 5, or 2 to 3. The number of carboxy groups may be, for example, 1 to 5, or 1. It may be.

[0026] The analogue of 9,10,16-trihydroxyhexadecanoic acid may specifically be, for example, an omega hydroxy acid other than 9,10,16-trihydroxyhexadecanoic acid having 16 to 18 carbon atoms, 2 to 3 hydroxy groups, and one carboxy group.

[0027] 9,10,16-trihydroxyhexadecanoic acid analogs are derivatives of omega-hydroxy acids. For example, the compound may be a compound in which one or more of the functional groups of the hydrocarbon chain, hydroxy group, and carboxy group of the omega hydroxy acid are substituted with various substituents. Examples of the substituent include, but are not limited to, an alkyl group, an acyl group, an alkoxy group, a hydroxyl group, an amino group, an alkylamino group, a nitro group, a cyano group, a halogen atom, and various protecting groups.

[0028] Furthermore, the active ingredient of the marine biodegradation rate accelerator of the present invention may be a monomer selected from 9,10,16-trihydroxyhexadecanoic acid or its analogues, an oligomer containing such a monomer (preferably an oligomer of a monomer selected from 9,10,16-trihydroxyhexadecanoic acid or its analogues), or a polymer containing such a monomer (preferably a polymer of a monomer selected from 9,10,16-trihydroxyhexadecanoic acid or its analogues). For example, without limitation, the oligomer may have a degree of polymerization of 2 or more and 100 or less, and the polymer may have a degree of polymerization of 100 or more.

[0029] The active ingredient of the marine biodegradation rate accelerator of the present invention can be one or a combination of two or more selected from a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or its analogues, an oligomer containing said monomer, and a polymer containing said monomer.

[0030] As the monomers, oligomers containing said monomers, and polymers containing said monomers used in the present invention, which are composed of 9,10,16-trihydroxyhexadecanoic acid or its analogs, it is also possible to use the monomers that constitute cutin contained in plants, as well as their oligomers and polymers. The monomers that make up cutin are mainly of two types: the C16 family and the C18 family. The C16 family consists of 16-hydroxyhexadecanoic acid (16HHD), 7,16-dihydroxyhexadecanoic acid (7HHD), and 16HHD. It consists of canic acid, 8,16-dihydroxyhexadecanoic acid, 9,16-dihydroxyhexadecanoic acid, 10,16-dihydroxyhexadecanoic acid, (Z)-16-hydroxyhexadec-9-enoic acid, 9,10-epoxy-16-hydroxyhexadecanoic acid, 9,10,16-trihydroxyhexadecanoic acid, etc. The C18 family includes 18-hydroxyoctadecanoic acid, 9,18-dihydroxyoctadecanoic acid, Acid, 10,18-dihydroxyoctadecanoic acid, (Z)-18-hydroxyoctadec-9-enoic acid, 9,10-epoxy-18-hydroxyoctadecanoic acid, 9,10,18-trihydroxyoctadecanoic acid, (Z)-octadec-9-enedioic acid, (9Z,12Z)-18-hydroxyoctadeca-9,12-dienoic acid, (Z)-9,10-epoxy-18-hydroxyoctadec-12-enoic acid, (Z)-9,10,18-trihydroxyoctadecanoic acid It is composed of 12-enoic acid, (6Z,9Z)-octadeca-6,9-dienedioic acid, etc.

[0031] Monomers that may be used in the present invention include, but are not limited to, 7,16-dihydroxyhexadeca acid, 8,16-dihydroxyhexadecanoic acid, 9,16-dihydroxyhexadecanoic acid, 10,16-dihydroxyhexadecanoic acid, (Z)-16-hydroxyhexadec-9-enoic acid, 9,10-epoxy-16-hydroxyhexadecanoic acid, 9,10,16-trihydroxyhexadecanoic acid, 9,18-dihydroxyoctadecanoic acid, 10,18-dihydroxyoctadecanoic acid, (Z)-18-hydroxyoctadec-9-enoic acid, 9,10-epoxy-18-hydroxyoctadecanoic acid, 9,10,18-trihydroxyoctadecanoic acid Tadecanoic acid, (Z)-octadec-9-enedioic acid, (9Z,12Z)-18-hydroxyoctadeca-9,12-di Enoic acid, (Z)-9,10-epoxy-18-hydroxyoctadec-12-enoic acid, (Z)-9,10,18-trihydroxyoctadec-12-enoic acid hydroxyoctadec-12-enoic acid, (6Z,9Z)-octadeca-6,9-dienedioic acid The monomer may be a monomer selected from 9,10,16-trihydroxyhexadecanoic acid or a derivative thereof.

[0032] Monomers consisting of 9,10,16-trihydroxyhexadecanoic acid or its analogs, oligomers containing such monomers, and polymers containing such monomers may be extracted from plants or the like by conventional methods and purified as necessary, or may be synthesized by conventional methods, or may be commercially available products manufactured by Tokyo Chemical Industry Co., Ltd., etc.

[0033] The blending ratio of one or more selected from a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing the monomer, and a polymer containing the monomer in the marine biodegradation rate accelerator is not limited, but can be, for example, about 0.001 to 100% by weight, 0.01 to 90% by weight, 0.1 to 80% by weight, 1 to 70% by weight, 10 to 60% by weight, or 20 to 50% by weight relative to the total amount of the marine biodegradation rate accelerator.

[0034] The marine biodegradation rate accelerator may be composed of one or more selected from the group consisting of a monomer of 9,10,16-trihydroxyhexadecanoic acid or its analogs, an oligomer containing the monomer, and a polymer containing the monomer. Optionally, it may also contain additives for formulation, such as solvents, excipients, and stabilizers. In other words, the marine biodegradation rate accelerator can also be referred to as a "marine biodegradation rate accelerator composition." The additives can be used alone or in combination of two or more. Optionally, it may also contain a nutrient source necessary for the growth of biodegradable resin-degrading microorganisms.

[0035] The formulation of the marine biodegradation rate accelerator is not particularly limited, and may be in the form of a powder, pellet, film-like solid, or dissolved or dispersed in a hydrophilic or lipophilic liquid, sol, or gel. The formulation of the marine biodegradation rate accelerator can be carried out according to conventional methods.

[0036] <Marine biodegradable resin composition> Another aspect of the present invention relates to a marine biodegradable resin composition having an accelerated marine biodegradation rate, comprising a biodegradable resin and the marine biodegradation rate accelerator of the present invention (hereinafter, sometimes referred to as the "marine biodegradable resin composition of the present invention"). All of the matters explained in the above section on "Marine biodegradation rate accelerator" also apply to the marine biodegradable resin composition of the present invention.

[0037] The marine biodegradable resin composition of the present invention contains the biodegradable resin and a marine biodegradation rate accelerator, and can significantly accelerate biodegradation even when the ratio of the marine biodegradation rate accelerator to the biodegradable resin is small. Therefore, the biodegradability of the biodegradable resin can be improved or accelerated without significantly impairing the mechanical properties, etc. of the biodegradable resin. Furthermore, the biodegradability of the biodegradable resin can be controlled by the amount of marine biodegradation rate accelerator used.

[0038] The blending ratio of the marine biodegradation rate accelerator in the marine biodegradable resin composition is not limited, but can be, for example, about 0.1 to 50% by weight, 1 to 30% by weight, or 10 to 20% by weight relative to the total amount of the marine biodegradable resin composition.

[0039] The marine biodegradable resin composition may contain, as necessary, various additives that are commonly used in biodegradable resin compositions, such as plasticizers for the biodegradable resin, stabilizers (antioxidants, heat stabilizers, light resistance stabilizers, etc.), surfactants, lubricants, colorants, fillers, antistatic agents, silane coupling agents, dispersants, dispersing aids, mold release agents, etc. The additives may be used alone or in combination of two or more.

[0040] The marine biodegradable resin composition may be in the form of a mixture of a biodegradable resin and a marine biodegradation rate accelerator, or may be in the form of an integrated mixture of the biodegradable resin and the marine biodegradation rate accelerator (for example, a powder or pellet).

[0041] The mixture of the biodegradable resin and the marine biodegradation rate accelerator may be in the form of a film formed on the biodegradable resin, or may be laminated by being coated on the surface of the biodegradable resin, for example. The lower limit of the thickness of the laminated layer is, for example, 0.75 μm or more, 1 μm or more, or 3 μm or more. The upper limit may be, for example, 100 μm or less, 50 μm or less, or 10 μm or less. .

[0042] The marine biodegradable resin composition can be produced by a conventional method, and examples thereof include a method of forming a film on one or both surfaces of a biodegradable resin by lamination using a coating liquid prepared by dissolving or dispersing a marine biodegradation rate accelerator and a binder in a liquid such as water. Specifically, for example, a molten coating liquid is poured from a T-die onto the film. Examples of methods include extrusion lamination, in which a film is extruded into a film and then cooled and pressed onto a biodegradable resin laminated on a separately unwound substrate using a cooling roll, and thermal lamination, in which a film formed from a pre-prepared coating liquid is heated and pressed onto the biodegradable resin laminated on a substrate. Other examples include a method in which a coating liquid in which a marine biodegradation rate accelerator is dissolved or dispersed in a liquid such as water is applied to one or both surfaces of a biodegradable resin, and then heated to dry and form a film.

[0043] Furthermore, the marine biodegradable resin composition can be produced, for example, by feeding at least the biodegradable resin and the marine biodegradation rate accelerator into an extruder and melt-kneading the mixture. In the melt-kneading step, the biodegradable resin, the marine biodegradation rate accelerator, and, if necessary, additives may be fed into the extruder separately, or the components may be mixed and then fed into the extruder. The melt-kneading in the melt-kneading step can be carried out using, for example, an extruder (single-screw extruder, twin-screw extruder), a kneader, or the like.

[0044] The marine biodegradable resin composition can be produced in the same manner as in the production of ordinary polymer compositions, except that it contains a marine biodegradation rate accelerator in addition to the biodegradable resin.

[0045] <Molded products> Another aspect of the present invention relates to a molded article formed from the marine biodegradable resin composition of the present invention (hereinafter, sometimes referred to as the "molded article of the present invention"). The matters explained in the above sections "Marine biodegradation rate accelerator" and "Marine biodegradable resin composition" all apply to the explanation of the molded article of the present invention.

[0046] The marine biodegradable resin composition of the present invention can be molded into films, sheets, and other molded articles such as instruments, containers, and nonwoven fabrics having shapes suitable for the intended use.

[0047] There are no particular limitations on the method for obtaining a film or sheet made from the marine biodegradable resin composition of the present invention, and the composition can be molded into a film or sheet by a known molding method. Examples include T-die molding, inflation molding, calendar molding, and hot press molding. These films and sheets may also be stretched in at least one direction. There are no particular limitations on the stretching method, and examples include roll stretching, tenter molding, and inflation molding.

[0048] There are no particular limitations on the method for obtaining a molded article made of the marine biodegradable resin composition of the present invention in a shape suitable for the intended use, and it can be produced by any known method, such as extrusion molding or injection molding in a mold. The thickness of the molded article of the marine biodegradable resin composition of the present invention is preferably thin to enhance its water disintegrability and biodegradability, but can be freely adjusted to satisfy strength, flexibility, etc. The preferred thickness of the film is 5 to 300 μm, and more preferably 10 to 100 μm. The thickness of the sheet or container-shaped molded product is preferably 0.1 to 5 mm, more preferably 0.2 to 2 mm. The tensile modulus is not particularly limited, but is usually 1200 MPa or more. The tensile strength is not particularly limited, but is preferably in the range of 10 to 100 MPa, more preferably in the range of 15 to 70 MPa. More preferably, the pressure is in the range of 20 to 50 MPa.

[0049] There are no particular limitations on the method for obtaining a nonwoven fabric of the marine biodegradable resin composition of the present invention, and it can be produced by a known method, such as a dry method, a spunbond method, a meltblowing method, a wet method, etc. That is, the nonwoven fabric can be obtained by spinning the marine biodegradable resin composition of the present invention or a composition containing the marine biodegradable resin composition and an additive, forming a web, and bonding the web by a known method.

[0050] The uses of molded articles containing the marine biodegradable resin composition of the present invention are not particularly limited, and they can be used, for example, as members (components) constituting sanitary products, agricultural and horticultural materials, civil engineering and construction materials, fishing materials, etc. In other words, sanitary products, agricultural and horticultural materials, civil engineering and construction materials, fishing materials, etc. can be produced using materials containing the marine biodegradable resin composition of the present invention.

[0051] Sanitary products, agricultural and horticultural materials, civil engineering and construction materials, fishing materials, etc. can be produced by molding a composition containing the marine biodegradable resin composition of the present invention into a desired shape, and then the molded products can be bonded and fixed to each other by known methods such as hot melt bonding or thermal bonding.

[0052] Examples of the sanitary products include disposable diapers, incontinence pads, and sanitary napkins. Examples of the agricultural and horticultural materials include mulch films, seedling pots, gardening tapes, fruit cultivation bags, stakes, fumigation sheets, and films for vinyl greenhouses. Examples of the civil engineering and construction materials include vegetation nets, vegetation pots, three-dimensional netting, civil engineering fibers, stakes, and heat insulating materials. Examples of the fishing materials include fishing nets, aquaculture equipment, fishing tackle, mooring ropes, fenders, sea anchors, floats, and the like.

[0053] <Method for Accelerating Biodegradation Rate and Biodegradation Method> Another aspect of the present invention relates to a method for accelerating the biodegradation rate of a biodegradable resin in a marine environment by contacting the biodegradable resin with the marine biodegradation rate accelerator of the present invention (hereinafter sometimes referred to as the "biodegradation rate acceleration method of the present invention"). In another aspect, the present invention relates to a method for biodegrading a biodegradable resin in a marine environment by contacting the biodegradable resin with the marine biodegradation rate accelerator of the present invention (hereinafter sometimes referred to as the "biodegradation method of the present invention"). As described above, contacting a biodegradable resin with the marine biodegradation rate accelerator of the present invention accelerates the biodegradation rate of the biodegradable resin in a marine environment, thereby enabling the biodegradation of the biodegradable resin. The step of contacting a biodegradable resin with the marine biodegradation rate accelerator of the present invention in the biodegradation rate acceleration method and biodegradation method of the present invention can be carried out under the conditions and by the techniques described above in the "Marine Biodegradation Rate Accelerator" and "Marine Biodegradable Resin Composition" of the present invention. That is, for example, by adding, mixing, or blending the marine biodegradation rate accelerator of the present invention with a biodegradable resin (or by adding, mixing, or blending a biodegradable resin with the marine biodegradation rate accelerator of the present invention), the biodegradation of the biodegradable resin can be accelerated and the biodegradation of the biodegradable resin can be achieved when the biodegradable resin is placed in a marine environment. That is, the method for accelerating the biodegradation rate of the present invention may be, for example, a method for accelerating the biodegradation of a biodegradable resin in a marine environment, which includes a step of adding, mixing, or blending the marine biodegradation rate accelerator of the present invention to the biodegradable resin. Furthermore, the biodegradation method of the present invention may be, for example, a method for biodegrading a biodegradable resin in a marine environment, which includes a step of adding, mixing, or blending the marine biodegradation rate accelerator of the present invention to the biodegradable resin.

[0054] The form in which the marine biodegradation rate accelerator of the present invention is added, mixed, or blended with a biodegradable resin may be such that the marine biodegradation rate accelerator is formed into a film on the biodegradable resin, or the marine biodegradation rate accelerator is laminated by being coated on the surface of the biodegradable resin, etc. Furthermore, the form in which the marine biodegradation rate accelerator of the present invention is added, mixed, or blended with the biodegradable resin may be a form in which the marine biodegradation rate accelerator is kneaded with the biodegradable resin to be integrated. Furthermore, the form in which the marine biodegradation rate accelerator of the present invention is added to, mixed with, or blended with a biodegradable resin may be a form in which the biodegradable resin and the marine biodegradation rate accelerator are brought into contact with each other at the time of use.

[0055] The amount of the marine biodegradation rate accelerator used in the biodegradation rate acceleration method and biodegradation method of the present invention is not limited. For example, One or more compounds selected from cyclohexadecanoic acids can be applied in an amount of about 1 to 500 parts by weight, 10 to 100 parts by weight, or 30 to 50 parts by weight.

[0056] Another aspect of the present invention may be, for example, a method for producing the marine biodegradable resin composition of the present invention, which includes a step of adding, mixing, or blending the marine biodegradation rate accelerator of the present invention to a biodegradable resin.

[0057] The matters explained in the sections "Marine biodegradation rate accelerator", "Marine biodegradable resin composition", and "Molded article" all apply to the explanation of the method for accelerating the biodegradation rate and the biodegradation method of the present invention.

[0058] Here, "accelerating the biodegradation rate of a biodegradable resin in a marine environment" is not limited to, but may mean that the biodegradation rate of a biodegradable resin to which the marine biodegradation rate accelerator of the present invention has been added is increased compared to the biodegradation rate of a biodegradable resin to which the marine biodegradation rate accelerator of the present invention has been added in a marine environment, and is not limited to, for example, the biodegradation rate of a biodegradable resin to which the marine biodegradation rate accelerator of the present invention has been added is 1.25 times or more, 1.5 times or more, 2 times or more, 5 times or more, 10 times or more, or 15 times or more than the biodegradation rate of a biodegradable resin to which the marine biodegradation rate accelerator of the present invention has not been added. Whether or not the biodegradation rate of a biodegradable resin has increased can be confirmed by a degradation test such as that shown in the Examples below. For example, the amount of weight loss is calculated from the difference between the initial weight of the sample and the weight after a seawater immersion test, and the weight loss is divided by the surface area of ​​the sample and the immersion period to obtain the weight loss rate. Using this as an index, if the biodegradation rate of a biodegradable resin to which the marine biodegradation rate-accelerating agent of the present invention has been added is faster than that of a biodegradable resin to which the marine biodegradation rate-accelerating agent of the present invention has not been added, it can be determined that the biodegradation rate of the biodegradable resin has increased. [Example]

[0059] The present invention will be specifically described below with reference to examples, but these are merely examples of the present invention and the scope of the present invention is not limited to these examples.

[0060] <Experimental Method> Reagents Poly(butylene adipate-co-butylene succinate) (hereinafter referred to as PBSA) (Mn = 7.7 x 10 4 , Mw= 16.4 x 10 4 ), poly(butylene succinate) (hereinafter referred to as PBS) (Mn = 3.5 x 10 4 , Mw= 10.7 x 10 4 ) was provided by Mitsubishi Chemical Corporation. Poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (hereinafter referred to as PHBV) was provided by HighChem Co., Ltd. The polymer was dissolved in chloroform and reprecipitated by adding methanol. It was collected by suction filtration, dried in vacuum, and then used in the experiment. Aromatic acid (AA) was purchased from Tokyo Chemical Industry Co., Ltd. Other reagents were purchased from Merck Ltd. and Wako Pure Chemical Industries, Ltd. , Tokyo Chemical Industry Co., Ltd., and Kishida Chemical Co., Ltd., and used as received.

[0061] The polymer films were prepared by melt pressing. The polymer was placed in a mold and pressed at a pressure of 15 MPa for 1 minute at a temperature of 130°C (for PBSA) or 140°C (for PBS) using a press (manufactured by the company). The polymer film was cut into 2 × 2 cm pieces and washed with distilled water. It was washed twice, then dried under reduced pressure and used in the experiment.

[0062] <Seawater sample> The seawater sample was collected from the quay of the JAMSTEC headquarters in Yokosuka City, Kanagawa Prefecture (hereafter referred to as Yokosuka seawater). (This is the case.)

[0063] <Melting and kneading> The alloyic acid-mixed polymers used as control substances were prepared using a HAAKE™ MiniLab 3 Micro Compounder (manufactured by ThermoFisher Scientific) (twin-screw compounder). The compounding temperature was 140°C for PBS and 130°C for PBSA. The controlled substance-mixed polymer compositions were prepared by mixing at a shaft rotation speed of 50 rpm / min for 5 minutes.

[0064] <Film decomposition test in a water tank> The water tank immersion test was conducted indoors. 7 L of Yokosuka seawater was placed in a 7 L water tank, and an external filter was installed. Each film was placed in a stainless steel mesh bag, tied with nylon line, and hung in the installed water tank. When immersing compounded polymers, one water tank was used for each compounded substance. The room temperature was set at 20°C. In accordance with ASTM D6691-17, 0.5 g / L of NH4Cl and 0.1 g / L of KH2PO4 were added to each water tank.

[0065] <Film decomposition test in sterilized artificial seawater> Artificial seawater was prepared according to ASTM D 1141. 1 L of artificial seawater was then added to a medium bottle, autoclaved at 121°C for 15 minutes, and then cooled to room temperature to prepare sterilized artificial seawater. The film (1 x 1 x 0.1 cm) was washed with 0.1% benzalkonium chloride, placed in an autoclave-sterilized stainless steel mesh bag, tied with nylon fishing line, suspended in a medium bottle containing sterilized artificial seawater, tightly closed, and left to stand at 20°C.

[0066] <Calculation of weight loss rate> The films were collected after one and two months, washed twice with distilled water, and then dried under reduced pressure. The film weight loss rate was calculated using the following formula from the weight loss amount, surface area, and immersion period of each film. N = 5 tests were conducted.

[0067]

number

[0068] <DNA / RNA extraction> DNA and RNA were extracted from each polymer film immersed in seawater using the ZymoBIOMIC™ DNA / RNA Miniprep Kit according to the manual. The DNA / RNA concentrations were measured using the Nabi ultra-microspectrophotometer. For each polymer film measuring 2 x 2 cm in appearance, a bead tube was used. One filter was used. Metagenome extraction from seawater was performed as follows: To capture microorganisms in the seawater, a membrane filter (pore size 0.45 μL, cellulose mixed ester type, ADVENTEC) was used, and the seawater was filtered by suction filtration, and the membrane was collected. DNA and RNA were extracted from the membrane filters in the same manner as for the polymer films. and RNA was dissolved in 70 μL of DNA / RNA-free water.

[0069] <Surface morphology observed using a scanning electron microscope (SEM)> For biofilm observation, the film was removed from the seawater and placed in a 2.5% (v / v) glutaraldehyde (scanning electron microscope grade) solution adjusted to phosphate buffer solution (pH 7.4) for one hour. The film was washed with ultrapure water and then immersed in aqueous ethanol solutions of varying concentrations (50, 60, 70, 80, 90, 99.5% (v / v)) for 20 minutes each to dehydrate. The film was immersed in tert-butyl alcohol for one hour, allowed to dry naturally, and then dried under reduced pressure overnight. This was then coated with a metal (Au) using a DII-29010SCTR Smart Coater (manufactured by JEOL Ltd.), and observed under a scanning electron microscope (JCM-7000 NeoScope (trademark), manufactured by JEOL Ltd.). The observation was carried out under high vacuum conditions at a voltage of 10 kV.

[0070] <Biodegradability evaluation based on biological oxygen demand> To measure the biodegradability of the samples, a biological oxygen demand (BOD) measurement test was conducted. The BOD measurement test was based on a reference using sediment (Taguchi, Sakao, and Kikuchi; Journal of Materials Life, 33[3] 57-64). Biodegradability was evaluated at 30°C using an OxiTop-IDS (Xylem Analytics). 600 mL of seawater and marine soil (Hiroshima) were collected in a 1000 mL flask and subjected to ultrasonic irradiation for 10 seconds using an ultrasonic irradiation device. After ultrasonic irradiation, the seawater was naturally filtered using cellulose quantitative filter paper (No. 2, ADVANTEC), and 0.5 g / L of NH4Cl and 0.1 g / L of KH2PO4 were added and stirred. 300 In a 100 mL bottle, add 150 mL of seawater, approximately 6 mg of sample, and 200 mL of 5 g / mL allylthiourea. A blank was also prepared without adding any sample. Approximately 5 g of Yabashi Lime® was added to the absorbent container, and then the BOD head was attached. Biodegradability was calculated using the following formula:

[0071]

number

[0072] where BOD b , B.O.D. t , ThOD represent the BOD of the blank, the BOD of the test solution, and the theoretical oxygen demand, respectively.

[0073] <GPC> The molecular weights of various polymers were analyzed by gel permeation chromatography (GPC, RI-4030, PU-4180, CO-4060, AS-4550, LC-NetII / ADC, JASCO Co.). TSKgel MultiporeHXL-M, TSKgel MultiporeHXL-M, TSKgel GRCHR (Tosoh Corporation) and a guard column, TSKgel guardcolumn MP (XL) (Tosoh Corporation), were used, with chloroform as the mobile phase. The column temperature was 40°C and the flow rate was 1.0 mL / min. A standard curve was prepared using TSK standard polystyrene (Tosoh Corporation, number average molecular weight: 1.0 × 10 6 , 3.5×10 5 , 9.5×10 4 , 3.9 × 10 4 , 8.9×10 3 , 2.6×10 3 , 8.7 x10 2 The sample (1 mg) was added to chloroform (1.0 mL) to prepare the measurement solution. The prepared solution was filtered through a 0.45 μm pore size filter and measured by manual injection (100 μm). The number average molecular weight (Mn) and polydispersity (Mw / Mn) of each sample were determined.

[0074] <Result> <Film weight loss in water tank immersion test> After the water tank immersion test, the PBSA and PBSA containing 10 w / w% aleuritic acid were mixed with PBS. The weight loss rates of the films (PBSA + 10% AA and PBS + 10% AA, respectively) and the control PBSA and PBS films are shown in Figure 1 and Table 1. The weight loss rate of PBSA + 10% AA after immersion for 1 month (30 days) was The film weight loss after 2 months (60 days) of immersion in PBSA + 10% AA was approximately 17 times higher than that of PBSA. The rate was smaller than that of the 1-month group, but about 19 times higher than that of the PBSA group. The weight loss rate of the PBS+10% AA film after immersion for 2 months was approximately 58 times higher than that of the PBS film. Although the weight loss rate of the PBSA+10%AA film after immersion for one month was smaller than that after immersion for one month, , which was approximately 76 times higher than that of PBS alone.

[0075] [Table 1]

[0076] <Film weight loss in sterilized artificial seawater> The weight loss rates of PBSA, PBS, PBSA + 10% AA, and PBS + 10% AA in sterile artificial seawater at 20°C are shown in Figure 2 and Table 2. After one month, the weight loss rates of PBSA + 10% AA and PBS + 10% films in sterile artificial seawater were 30.00 ± 2.90 and 9.7 ± 0.55, respectively. From these results, it is believed that the alloyic acid breaks down and loses weight when immersed in sterile artificial seawater. This is 0.2 times the weight loss rate in the actual ocean. , which was smaller than that in the real ocean.

[0077] [Table 2]

[0078] <Film surface morphology observation> Photographs of the films of PBSA, PBS, and their mixture before and after the water tank immersion test are shown in Figures 3 and 4. In the case of the films of PBSA and its mixture, the films were translucent before decomposition, but after immersion, The film turned white. In contrast to the PBS solution, no change in the surface morphology was observed before and after immersion. However, the film changed from translucent to white after immersion in a PBS+10% AA tank and after immersion in sterile artificial seawater. Ta.

[0079] The results of SEM observation of the surface morphology of each sample are shown in Figures 5 to 10. The SEM images of PBSA and PBS before degradation showed smooth surfaces. On the other hand, the SEM images of PBSA + 10% AA and PBS + 10% AA before degradation showed uneven surfaces, and powder-like adhesions were observed. Small cracks and holes were observed on the PBSA surface after immersion in real seawater for one and two months. On the other hand, large holes and cracks were observed on the PBSA + 10% AA surface after immersion in real seawater for one and two months, and the surface had become rough (Figure 5). Small holes and cracks were observed on the PBSA + 10% AA surface after immersion in sterilized artificial seawater. Although small holes were observed, their morphology was different from that observed in real seawater. Furthermore, biofilm formation was confirmed on the surfaces of PBSA and PBSA + 10% AA after immersion in real seawater (Figure 7).

[0080] The surface of the PBS after immersion in real seawater for one and two months was as smooth as before degradation. After immersion in real seawater for 1 month and 2 months, large holes were observed on the PBS+10%AA surface, which became rough (Figure 6). After immersion in sterilized artificial seawater, small holes were observed on the surface of PBS+10%AA, similar to those on PBSA+10%AA. However, the morphology was different from that of decomposition in the actual ocean. On the other hand, the adhesion of microorganisms to the PBS+10%AA surface after immersion in real seawater was hardly observed. Biofilm formation was confirmed on the surface (Figure 8).

[0081] Figure 9 shows SEM images of the PBSA and its kneaded film before and after the immersion test in a sterilized artificial seawater tank. The film surface before decomposition was smooth. On the other hand, after immersion for one month, the washed PBSA film surface remained unchanged. The kneaded film surface showed some changes. After immersion for two months, the kneaded film surface The film surface remained unchanged after one month of immersion (Figure 9).

[0082] Figure 10 shows SEM images of the PBS and its mixed film before and after the immersion test in a sterile artificial seawater tank. The film surface before decomposition was smooth. On the other hand, after one month of immersion, the washed PBS film surface There was no change in the film surface of the kneaded material. After immersion for 2 months, the film surface of the kneaded material The film surface remained unchanged after one month of immersion (Figure 10).

[0083] ≪DNA / RNA concentration≫ The DNA and RNA concentrations extracted from each film after one and two months of immersion are shown in Table 3 and Figures 11 and 12. Comparing the DNA concentrations of PBSA and PBSA + 10% AA after one month of immersion, the DNA concentrations of PBSA + 10% AA were higher than those of PBSA + 10% AA. The DNA concentration in PBSA+10%AA was larger, about 23 times that in PBSA. After 2 months of immersion, the DNA concentration in PBSA+10%AA was also larger. Comparing the PBSA+10%AA immersion samples after 1 month and 2 months, the DNA concentration in PBSA+10%AA immersion samples was The RNA concentration was higher in the PBSA + 10% AA solution at 1 month, approximately three times that of the PBSA solution at 2 months, and approximately twice that of the PBSA solution at 2 months (Figure 12).

[0084] Comparing the DNA concentration in PBS and PBS+10%AA, the DNA concentration in PBS+10%AA was higher, about 36 times that of PBS. After 2 months of immersion, the DNA concentration in PBS+10%AA was also higher. When comparing the PBS+10% AA samples immersed for 1 month and 2 months, the PBS+10% AA samples immersed for 1 month showed a larger increase (Figure 11 As with DNA concentration, the RNA concentration was higher in the PBS+10% AA solution, approximately 12 times that of the PBS solution at 1 month and approximately 14 times that of the PBS solution at 2 months (Figure 12).

[0085] [Table 3]

[0086] <Biodegradability evaluation based on biochemical oxygen demand> The BOD biodegradation curves for each sample are shown in Figure 13. The BOD biodegradation curve for aroiritic acid increased rapidly from the first day, reached 70% in 10 days, and plateaued. The BOD biodegradation curve for PBSA + 10% AA increased rapidly from the first day. The BOD biodegradability gradually increased from 0.01 to 0.25, and reached 65% on the 88th day. On the other hand, the BOD biodegradability of PBSA was 0%. there were.

[0087] <GPC> The molecular weight distribution curves of PBSA, PBSA+10%AA, PBS, and PBS+10%AA are shown in Figures 14 and 15. The calculated relative number average molecular weight, weight average molecular weight, and polydispersity are shown in Table 4. The molecular weight curve for PBS+10%AA was also shifted to the lower molecular weight side compared to that for PBS. The amount and weight average molecular weight were smaller than those of the neat polymer.

[0088] [Table 4]

[0089] In this study, 10% (w / w) of aroiritic acid, a type of cutin monomer, was added to polyester PBSA and PBS by melt blending, and the polymer blended material and neat polyester were compared in real seawater and sterilized artificial seawater. A decomposition test of the film was conducted. The mass loss rates of PBSA+10%AA and PBS+10%AA in real seawater were both greater than those of neat polymer PBSA and PBS. PBSA+10%AA and PBS+10% showed mass loss in sterile artificial seawater, but From these results, it is thought that the mass loss of PBSA+10%AA and PBS+10%AA in real seawater is due to microbial action and the elution of the additive, aleuritic acid. can be.

[0090] After immersion in sterile artificial seawater, small holes were observed all over the surface of PBSA+10%AA and PBS+10%AA. This is thought to be evidence of the elution of aroiritic acid during decomposition. However, the SEM image of the PBSA+10%AA film surface after immersion in real seawater was different from that after immersion in sterilized artificial seawater. In the SEM image of the PBS+10%AA film surface after immersion, small holes were observed, similar to those observed after immersion in sterilized artificial seawater. However, unlike after immersion in sterilized artificial seawater, a lamellar structure of spherulites, which is formed by preferential hydrolysis of the amorphous portion, also appeared. No differences were observed on the PBS film surface before and after decomposition. These results suggest that adding arylene acid to PBSA and PBS can contribute to the development of marine It is thought that this significantly induces the microbial degradation of PBSA and PBS.

[0091] The DNA concentrations extracted from PBSA and PBS after immersion were lower than those from PBSA + 10% or PBS + 10% AA. Furthermore, the results of SEM analysis also showed that there were relatively few microorganisms attached to the surfaces of PBSA and PBS film. These results suggest that adding aleuritic acid to PBSA and PBS can enhance the biodegradation of marine organisms. It was found to accumulate many microorganisms.

[0092] The BOD biodegradation of aryl nitrite showed a high value after 10 days and then plateaued. It was found that illitic acid is biodegradable in the ocean. In addition, the BOD biodegradability of PBSA + 10% AA was higher than that of PBSA, reaching 65% in 88 days. This suggests that adding 10% illitic acid to PBSA can contribute to the biodegradability of PBSA. This has been shown to improve the biodegradability of PBSA in the ocean.

[0093] These results demonstrate that aroiritic acid and its analogues accelerate the marine biodegradation rate of biodegradable resins. [Industrial Applicability]

[0094] It has been found that the use of the present invention can produce a resin composition that has a low risk of environmental pollution by microplastics even in the ocean and has an accelerated rate of marine biodegradation. The use of the present invention is effective in producing resin products that comply with future environmental regulations, etc.

Claims

1. A marine biodegradation rate accelerator for biodegradable resins, comprising at least one selected from the group consisting of a monomer consisting of 9,10,16-trihydroxyhexadecanoic acid or an analog thereof, an oligomer containing said monomer, and a polymer containing said monomer.

2. The monomers are 9,10,16-trihydroxyhexadecanoic acid, 7,16-dihydroxyhexadecanoic acid, Decanoic acid, 8,16-dihydroxyhexadecanoic acid, 9,16-dihydroxyhexadecanoic acid, 10,16-dihydroxyhexadecanoic acid, (Z)-16-hydroxyhexadec-9-enoic acid, 9,10-epoxy 16-hydroxyhexadecanoic acid, 9,18-dihydroxyoctadecanoic acid, 10,18-dihydro (Z)-18-Hydroxyoctadecanoic acid, (Z)-18-hydroxyoctadec-9-enoic acid, 9,10-epoxy-18-hydroxy 9,10,18-trihydroxyoctadecanoic acid, (Z)-octadec-9-enoic acid Dienoic acid, (9Z,12Z)-18-hydroxyoctadeca-9,12-dienoic acid, (Z)-9,10-epoxy-18-hydroxybenzoic acid 2. The marine biodegradable fast acting hydroxyoctadec-12-enoic acid of claim 1, wherein the fast acting hydroxyoctadec-12-enoic acid is selected from the group consisting of (Z)-9,10,18-trihydroxyoctadec-12-enoic acid, (Z)-9,10,18-trihydroxyoctadec-12-enoic acid, and (6Z,9Z)-octadeca-6,9-dienedioic acid. Degree promoter.

3. The marine biodegradation rate accelerator according to claim 1 , wherein the biodegradable resin is a polyester resin.

4. The marine biodegradation rate accelerator according to claim 1, wherein the biodegradable resin is at least one selected from the group consisting of polybutylene succinate adipate and polybutylene succinate.

5. biodegradable resins, and The marine biodegradation rate accelerator according to any one of claims 1 to 4, A marine biodegradable resin composition having an accelerated marine biodegradation rate, comprising:

6. A molded article formed from the marine biodegradable resin composition according to claim 5.

7. A method for accelerating the biodegradation rate of a biodegradable resin in a marine environment, comprising contacting the biodegradable resin with the marine biodegradation rate accelerator according to any one of claims 1 to 4.

8. A method for biodegrading a biodegradable resin in a marine environment, comprising contacting the biodegradable resin with the marine biodegradation rate accelerator according to any one of claims 1 to 4.

Images