Marine biodegradation accelerators and marine biodegradable compositions having hydrocarbon groups

Abstract

Provided is a marine biodegradation promoter that is a hydrophobic, thermoplastic powder composed of a compound in which ionic bonds bond a metal cation having a valence of two or higher and a monovalent organic anion derived from a substance selected from among monovalent carboxylic acids containing a monovalent hydrocarbon group having 10-25 carbon atoms, monovalent sulfonic acids containing a monovalent hydrocarbon group having 10-25 carbon atoms, monovalent sulfate esters containing a monovalent hydrocarbon group having 10-25 carbon atoms, and monovalent phosphate esters containing a monovalent hydrocarbon group having 10-25 carbon atoms, wherein the powder dissolves in a 3 mass% aqueous sodium chloride solution, or exhibits hydrophilicity in a 3 mass% aqueous sodium chloride solution.

Description

[Technical Field]

[0001] The present invention relates to a marine biodegradation accelerator and a marine biodegradable composition having a hydrocarbon group. [Background technology]

[0002] In recent years, environmental pollution (marine pollution) and adverse effects on ecosystems caused by microplastics have become a serious problem, and various initiatives to reduce the environmental burden have begun. Among these, the development and widespread use of biodegradable resins are attracting attention.

[0003] On the other hand, while general biodegradable resins exhibit high biodegradability in environments with many microorganisms responsible for decomposition, such as soil and sludge, they have the drawback of being difficult to decompose in environments with extremely low microbial concentrations, such as in the ocean (Non-Patent Literature 1). Furthermore, even for resins that have been reported to be biodegradable in the ocean, such as polycaprolactone (PCL) and polyhydroxyalkanoic acid (PHA), it has been found that the rate of decomposition varies greatly depending on the type of seawater. It has been reported that various factors such as the presence and number of decomposing bacteria in the seawater, salt concentration, pH, water temperature, dissolved oxygen concentration, and dissolved organic carbon content are influencing this (Non-Patent Literature 2).

[0004] Therefore, there is a need to develop materials that can be reliably decomposed in any type of seawater, and materials that can act as decomposition accelerators for resins that do not biodegrade easily in seawater. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Hideki Takada, "Current Status, International Trends, and Countermeasures Regarding Microplastic Pollution," Journal of the Japan Society of Waste Management and Resource Recycling, Vol. 29, No. 4, pp. 261-269, 2018. [Non-Patent Document 2] Akira Ebisu et al., "Decomposition of Biodegradable Plastics in Seawater," *Fisheries Engineering*, Vol. 40 No. 2, pp. 143-149, 2003. [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention has been made in view of the above circumstances, and aims to provide a biodegradation accelerator for promoting the biodegradation of resins and the like in the ocean, and a marine biodegradable composition containing the biodegradation accelerator. [Means for solving the problem]

[0007] The inventors, through diligent research to solve the aforementioned problems, have discovered that a hydrophobic powder material consisting of a compound in which a monovalent organic anion derived from one of the following—a monovalent carboxylic acid having a monovalent hydrocarbon group with 10 to 25 carbon atoms, a monovalent sulfonic acid having a monovalent hydrocarbon group with 10 to 25 carbon atoms, a monovalent sulfate ester having a monovalent hydrocarbon group with 10 to 25 carbon atoms, and a monovalent phosphate ester having a monovalent hydrocarbon group with 10 to 25 carbon atoms—is ionically bonded to a metal cation with two or more carbon atoms does not dissolve in freshwater, and despite being hydrophobic, it gradually dissolves or becomes hydrophilic in seawater. Unlike general biodegradable resins, primary decomposition (low molecular weighting) in seawater is not carried out by hydrolysis, enzymes, or microorganisms, but by molecular cleavage by metal ions such as sodium. Therefore, this material undergoes stable primary decomposition regardless of the type of seawater, and by being reduced to a low molecular weight structure that dissolves or blends with seawater, it can greatly promote hydrolysis, enzymes, and microbial decomposition. Furthermore, by using this material in combination with resin, particularly biodegradable resin, we discovered that the material undergoes primary decomposition in seawater first, resulting in (1) the formation of pores in the resin material, increasing the specific surface area of ​​the resin and promoting the growth of microorganisms responsible for decomposition, and (2) the primary decomposition promoting secondary decomposition, i.e., biodecomposition by microorganisms. As a result, we found that the biodecomposition of the resin material in the ocean can be promoted, thus completing the present invention.

[0008] In other words, the present invention provides a marine biodegradation accelerator and a marine biodegradable composition having the following hydrocarbon groups. 1. A marine biodegradation accelerator, which is a hydrophobic and thermoplastic powder, comprising a compound in which a monovalent organic anion derived from one selected from a monovalent carboxylic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfonic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfuric acid ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms, and a monovalent phosphate ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms is ionically bonded to a metal cation with two or more atoms, The aforementioned powder is a marine biodegradation accelerator that dissolves in a 3% by mass sodium chloride aqueous solution or exhibits hydrophilicity in a 3% by mass sodium chloride aqueous solution. 2. A marine biodegradation accelerator wherein the monovalent organic anion is derived from a monovalent carboxylic acid. 3. A marine biodegradation accelerator wherein the monovalent carboxylic acid is a monovalent fatty acid having a monovalent hydrocarbon group with 10 to 25 carbon atoms. 4. A marine biodegradation accelerator wherein the monovalent carboxylic acid is capric acid, lauric acid, myristic acid, palmitic acid, or stearic acid. 5. A marine biodegradation accelerator wherein the monovalent carboxylic acid is an amino acid derivative having a monovalent hydrocarbon group with 10 to 25 carbon atoms. 6. The marine biodegradation accelerator of 5, wherein the amino acid derivative is a sarcosinic acid derivative having a monovalent hydrocarbon group having 10 to 25 carbon atoms, or a glutamic acid derivative having a monovalent hydrocarbon group having 10 to 25 carbon atoms. 7. A marine biodegradation accelerator of 6, wherein the amino acid derivative is lauroyl sarcosine, myristoyl sarcosine, palmitoyl sarcosine, myristoyl glutamic acid, or stearoyl glutamic acid. 8. Any of the marine biodegradation accelerators 1 to 7 wherein the monovalent organic anion does not contain a ring structure. 9. Any of the marine biodegradation accelerators 1 to 8 wherein the monovalent organic anion contains an amide group. 10. A marine biodegradation accelerator according to any of 1 to 9, wherein the metal cation is a calcium ion, a magnesium ion, or an aluminum ion. 11. Any one of marine biodegradation accelerators 1 to 10, which is a powder having an average particle diameter of 0.1 to 10,000 μm. 12. Any one of marine biodegradation accelerators 1 to 11, which is a thermoplastic powder having a melting temperature of 60 to 230 °C. 13. Any one of marine biodegradation accelerators 1 to 12, wherein water droplets are dropped onto a melt-molded body of a particle group composed of the powder, and the contact angle after 30 seconds is 50° or more. 14. A marine biodegradable resin composition containing any one of marine biodegradation accelerators 1 to 13 and a resin. 15. The marine biodegradable resin composition according to 14, wherein the resin is a biodegradable resin. 16. The marine biodegradable resin composition according to 14 or 15, wherein the content of the marine biodegradation accelerator is 3 to 50% by mass, and the content of the biodegradable resin is 50 to 97% by mass. 17. A molded body obtained from any one of the marine biodegradable resin compositions according to 14 to 16.

Advantages of the Invention

[0009] The marine biodegradation accelerator of the present invention dissolves or becomes hydrophilic in seawater. Therefore, the composition and molded body containing this are promoted in biodegradation in the ocean and are useful for countermeasures against ocean pollution. By using the marine biodegradation accelerator of the present invention, an environmentally friendly composition and molded body can be obtained.

Brief Description of the Drawings

[0010] [Figure 1] SEM photograph (500 times) of the film of Example 5-2 after being immersed in water for 45 days. [Figure 2] SEM photograph (500 times) of the film of Example 5-2 after being immersed in a 3% by mass aqueous sodium chloride solution for 45 days. [Figure 3] SEM photograph (2,000 times) of the film of Example 6-3 after being immersed in water for 45 days. [Figure 4] SEM photograph (2,000 times) of the film of Example 6-3 after being immersed in a 3% by mass aqueous sodium chloride solution for 45 days.

Modes for Carrying Out the Invention

[0011] [Marine biodegradation accelerator] The marine biodegradation accelerator of the present invention is a hydrophobic and thermoplastic powder comprising a compound (hereinafter also referred to as a hydrophobic compound) in which a monovalent organic anion derived from one selected from a monovalent carboxylic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfonic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfate ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms, and a monovalent phosphate ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms is ionically bonded to a metal cation with two or more carbon atoms.

[0012] Considering the safety of the powder, including its melting temperature, degree of hydrophobicity, and irritancy, the monovalent hydrocarbon group is preferably one with 12 to 25 carbon atoms, more preferably one with 14 to 25 carbon atoms, and best of all, one with 14 to 20 carbon atoms. If the number of carbon atoms is less than 10, the melting temperature will be too high, making it difficult to melt and mix with the resin described later. On the other hand, if the number of carbon atoms exceeds 25, the melting temperature may decrease.

[0013] The monovalent organic anion is preferably derived from the monovalent carboxylic acid or monovalent sulfonic acid, and more preferably from the monovalent carboxylic acid. Furthermore, as the monovalent carboxylic acid, a fatty acid having a monovalent hydrocarbon group with 10 to 25 carbon atoms or an amino acid derivative having a monovalent hydrocarbon group with 10 to 25 carbon atoms is preferred. These monovalent organic anions are preferred because they have the characteristic of easily attracting fungi that are scarce in the ocean.

[0014] From the viewpoint of promoting biodegradability, it is preferable that the monovalent organic anion does not contain a ring structure. However, from the viewpoint of imparting physical properties, a ring structure may be introduced to the extent that it does not impair biodegradability and its control.

[0015] Furthermore, the monovalent organic anion is preferably one having an amide group or a carboxylic acid anhydride ring-opening group (for example, -C(=O)-CH2-CH2-C(=O)-(succinic acid), -C(=O)-CH=CH-C(=O)-)(maleic acid), -C(=O)-C6H4-C(=O)-(phthalic acid)).

[0016] The aforementioned metal cations with a valence of 2 or higher are not particularly limited, but include magnesium ions, calcium ions, aluminum ions, strontium ions, barium ions, radium ions, scandium ions, titanium ions, vanadium ions, chromium ions, manganese ions, iron ions, cobalt ions, nickel ions, copper ions, zinc ions, yttrium ions, zirconium ions, niobium ions, molybdenum ions, technetium ions, ruthenium ions, rhodium ions, palladium ions, silver ions, cadmium ions, lead ions, platinum ions, gold ions, and the like. Of these, calcium ions, magnesium ions, aluminum ions, zinc ions, iron ions, copper ions, and barium ions are preferred. Considering safety, calcium ions, magnesium ions, and aluminum ions are preferred. Considering the environment, calcium ions and magnesium ions are more preferred, and calcium ions are most preferred.

[0017] The powder comprising the hydrophobic compound dissolves in a 3% by mass sodium chloride aqueous solution, or exhibits hydrophilicity in a 3% by mass sodium chloride aqueous solution.

[0018] Furthermore, when the powder comprising the hydrophobic compound is dispersed in a 3% by mass aqueous solution of sodium chloride to a concentration of 0.1% by mass, and the transmittance of light at a wavelength of 560 nm of the dispersion after 15 days is defined as SD1(%), and when the marine biodegradation accelerator is dispersed in water to a concentration of 0.1% by mass, and the transmittance of light at a wavelength of 560 nm after 15 days is defined as WD1(%), it is preferable that WD1 / SD1 be 0.9 or less, more preferably 0.8 or less, and even more preferably 0.6 or less. If it is 0.9 or less, the phenomenon of the marine biodegradation accelerator particles changing shape, dissolving, and becoming transparent can be observed. The lower limit of WD1 / SD1 is not particularly limited, but is usually around 0.1. From the viewpoint of considering environmental impact and biodegradation promoting effect, it is preferable that WD1 / SD1 ≤ 0.9 is satisfied for about 15 days.

[0019] Furthermore, the powder comprising the hydrophobic compound is dispersed in water and a sodium chloride aqueous solution (sodium chloride concentration 3% by mass) to a concentration of 0.1% by mass, stirred at room temperature for 15 days, and dried. The weight loss rate ((AB) / A × 100 (%)) is determined from the weight B after drying and the weight A before dispersion. Let W be the weight loss rate in water and S be the weight loss rate in the sodium chloride aqueous solution. The degree of solubility or hydrophilization Z, calculated using Z=SW, is preferably 25 or higher, more preferably 50 or higher, and even more preferably 60 or higher. If Z is 25 or higher, the shape of the marine biodegradation accelerator particles changes in the sodium chloride aqueous solution used as simulated seawater, and the phenomenon of dissolution or hydrophilization progressing along with weight loss can be confirmed.

[0020] The aforementioned hydrophobic compound is designed to adequately satisfy environmental considerations, including solubility in water and brine, and biodegradability in the environment. Preferably, it has a molecular weight of 5,000 or less, more preferably 100 to 5,000, then 150 to 3,000, and finally 200 to 2,000, with 250 to 1,000 being the most preferred. In this invention, molecular weight refers to the number-average molecular weight (Mn) for polymers, where Mn is measured in polystyrene equivalents by gel permeation chromatography. For substances other than polymers, it refers to the chemical formula weight.

[0021] The powder comprising the hydrophobic compound preferably has an average particle size of 0.1 to 10,000 μm, more preferably 1.0 to 5,000 μm, and more preferably 3.0 to 3,000 μm. In particular, for applications where it is handled alone as primary particles, a particle size of 3.0 to 500 μm is preferred. In this invention, the average particle size is the volume-average particle size (MV) obtained by the laser diffraction-scattering method.

[0022] Furthermore, the powder comprising the hydrophobic compound is a thermoplastic powder with a melting temperature of 60 to 230°C, but preferably 60 to 200°C. A melting temperature within this range allows for uniform mixing with the resin through thermal melting, thus enabling the even and efficient creation of biodegradation initiation points in the ocean. This uniformity is also advantageous because it allows for control of variations in physical properties such as strength. A melting temperature of 70°C to 180°C is more preferable, and 90°C to 160°C is even more preferable. When mixing with a resin, it is preferable to adjust the melting temperature of the powder to within ±20°C of the resin's melting temperature.

[0023] The shape of the powder is not particularly limited, and may be spherical, approximately spherical, flat, or concave, or physically or chemically shaped, or physically pulverized. However, from the viewpoint of controlling texture, slipperiness, and particle size distribution, physically or chemically shaped powders such as spherical, approximately spherical, flat, or concave are preferred. The group of particles consisting of the marine biodegradation accelerator may also be compressed or melt-molded into pellets.

[0024] When a water droplet is dropped onto a molten body of the aforementioned powder particles, it is preferable that the contact angle after 30 seconds is 50° or higher. The molten body is a sheet for measuring the contact angle, formed by heating and melting particles. In this case, the hydrophobic effect, solubility in seawater, and decomposability are fully exhibited. Because the above effects are easily obtained, the contact angle is preferably 60° or higher, 70° or higher, and 80° or higher, in that order. The upper limit of the contact angle is not particularly limited, but a practical value is 170° or lower, 160° or lower, 150° or lower, and 140° or lower. Considering the practical hydrophobic effect and the time required for solubility in seawater and biodegradation, it is preferable that the contact angle satisfies 50° to 160°, more preferably 50° to 150°, even more preferably 60° to 140°, and most preferably 70° to 130°. The contact angle can be measured using a contact angle meter (for example, the Drop Master 300 manufactured by Kyowa Interface Science Co., Ltd.).

[0025] The hydrophobic compound is obtained by reacting a compound (hereinafter also referred to as starting compound A) consisting of a monovalent organic anion and a monovalent cation derived from one selected from a monovalent carboxylic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfonic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfuric acid ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms, and a monovalent phosphate ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms, with a polyvalent metal salt containing a metal cation of 2 or more valencies, thereby bonding the monovalent organic anion with the metal cation of 2 or more valencies.

[0026] The aforementioned monovalent organic anion is a carboxylic acid anion (-COO - ), sulfonate anion (-SO3 - ), sulfate anion (-O-SO3 - ) or phosphate anion (-P(=O)(OH)-O - It is an anion that possesses ).

[0027] From an environmental standpoint, examples of monovalent cations include monovalent metal ions such as hydrogen ions, lithium ions, sodium ions, potassium ions, and silver ions; and monovalent organic ions such as ammonium cations. Of these, sodium ions, potassium ions, and ammonium cations are preferred from the viewpoint of the environment, biosafety, versatility, and cost, sodium ions and potassium ions are more preferred, and sodium ions are even more preferred.

[0028] The molecular weight of raw material compound A is preferably 100 to 2,500. If the molecular weight is within this range, the physical properties of the resin, such as thermal meltability, and compatibility with other resins are maintained, it is compatible with seawater, and decomposition is easily achieved. The lower limit of the molecular weight is preferably 150 or more, followed by 200 or more. On the other hand, the upper limit is preferably 2,000 or less, followed by 1,500 or less, followed by 1,000 or less, and then 500 or less. In particular, the molecular weight of raw material compound A is preferably 150 to 800, more preferably 150 to 600, and even more preferably 200 to 500.

[0029] Furthermore, it is preferable that the raw material compound A is soluble in water at room temperature or below 80°C. Such a compound will blend well with seawater and allow for a good biodegradation rate.

[0030] Examples of starting material compound A include monovalent carboxylic acids or their salts, monovalent sulfonic acids or their salts, monovalent sulfuric acid esters or their salts, and monovalent phosphate esters or their salts.

[0031] The monovalent carboxylate salt is a salt consisting of an anion and a monovalent cation derived from a monovalent carboxylic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms. Preferred monovalent carboxylate salts include salts consisting of an anion and a monovalent cation derived from a fatty acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, and salts consisting of an anion and a monovalent cation derived from an amino acid derivative having a monovalent hydrocarbon group having 10 to 25 carbon atoms.

[0032] The aforementioned fatty acids include undecylenic acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, isostearic acid, oleic acid, vaccenic acid, ricinoleic acid, linoleic acid, linolenic acid, eleostearic acid, and oxystearic acid. ,a Examples include lacidic acid, meadic acid, arachidonic acid, eicosapentaenoic acid, behenic acid, docosahexaenoic acid, lignoceric acid, nervonic acid, cerotic acid, coconut oil fatty acids, palm oil fatty acids, etc. Branched isomers of these are also acceptable.

[0033] The fatty acid salt is preferably a monovalent metal salt, and specific examples include undecylenates such as potassium undecylenate and sodium undecylenate; laurates such as potassium laurate and sodium laurate; myristicates such as potassium myristate and sodium myristate; pentadecylates such as potassium pentadecylate and sodium pentadecylate; palmitates such as potassium palmitate and sodium palmitate; margarates such as potassium margarate and sodium margarate; stearates such as potassium stearate and sodium stearate; and potassium isostearate. Examples include isostearates such as sodium isostearate; oleates such as potassium oleate and sodium oleate; linoleates such as potassium linoleate and sodium linoleate; linolenates such as potassium linolenate and sodium linolenate; arachidates such as potassium arachidate and sodium arachidate; arachidates such as potassium arachidone and sodium arachidone; behenates such as potassium behenate and sodium behenate; docosahexaenoates such as sodium docosahexaenoate; and coconut oil fatty acid salts such as potassium coconut oil fatty acid and sodium coconut oil fatty acid. Of these, fatty acid salts having a monovalent hydrocarbon group with 10 to 20 carbon atoms, such as laurate, myristicate, palmitate, stearate, and arachidate, are preferred, and myristicate, palmitate, stearate, and arachidate are best when considering safety for the human body.

[0034] The amino acid derivative salt is more preferably one having 12 to 25 carbon atoms, and more preferably one having a monovalent hydrocarbon group with 14 to 20 carbon atoms. Furthermore, the salt of the amino acid derivative is preferably a monovalent salt, and more preferably a monovalent metal salt.

[0035] The aforementioned amino acid derivatives include sarcosine derivatives such as lauroyl sarcosine, myristoyl sarcosine, palmitoyl sarcosine, and coconut oil fatty acid sarcosine; glutamic acid derivatives such as lauroyl glutamic acid, myristoyl glutamic acid, palmitoyl glutamic acid, stearoyl glutamic acid, coconut oil fatty acid acyl glutamic acid, cocoyl glutamic acid, acyl glutamic acid, and dilauroyl glutamic acid; glycine derivatives such as lauroyl glycine, myristoyl glycine, palmitoyl glycine, palmitoyl methylglycine, coconut oil fatty acid acyl glycine, and cocoyl glycine; and methylalanine such as lauryl methylalanine, myristoyl methylalanine, cocoyl alanine, and coconut oil fatty acid methylalanine. Examples include derivatives of amino acids having a monovalent hydrocarbon group with 10 to 25 carbon atoms, such as: ranine derivatives; lysine derivatives such as lauroyl lysine, myristoyl lysine, palmitoyl lysine, stearoyl lysine, and oleyl lysine; aspartic acid derivatives such as lauroyl aspartic acid, myristoyl aspartic acid, palmitoyl aspartic acid, and stearoyl aspartic acid; taurine derivatives such as lauroyl taurine, lauroyl methyl taurine, myristoyl taurine, myristoyl methyl taurine, palmitoyl taurine, palmitoyl methyl taurine, stearoyl taurine, and stearoyl methyl taurine; and proline derivatives such as lauroyl proline, myristoyl proline, and palmitoyl proline. In particular, N-acyl derivatives of amino acids are preferred. Furthermore, as the amino acid derivatives, sarcosinic acid derivatives having a monovalent hydrocarbon group with 10 to 25 carbon atoms or glutamic acid derivatives having a monovalent hydrocarbon group with 10 to 25 carbon atoms are preferred. In particular, from the standpoint of melting point and safety for human health, lauroyl sarcosine, myristoyl sarcosine, palmitoyl sarcosine, myristoyl glutamate, and stearoyl glutamate are the best.

[0036] The aforementioned amino acid derivative salts include sarcosine derivative salts such as potassium lauroyl sarcosinate, sodium lauroyl sarcosinate, potassium myristoyl sarcosinate, sodium myristoyl sarcosinate, potassium palmitoyl sarcosinate, sodium palmitoyl sarcosinate, potassium coconut oil fatty acid sarcosinate, sodium coconut oil fatty acid sarcosinate; glutamic acid derivative salts such as potassium lauroyl glutamate, sodium lauroyl glutamate, potassium myristoyl glutamate, sodium myristoyl glutamate, sodium palmitoyl glutamate, potassium palmitoyl glutamate, potassium stearoyl glutamate, sodium stearoyl glutamate, potassium coconut oil fatty acid acyl glutamate, sodium coconut oil fatty acid acyl glutamate, potassium cocoyl glutamate, sodium cocoyl glutamate, sodium dilauroyl glutamate lysine; and potassium lauroyl glycine Glycine derivative salts such as sodium lauroyl glycinate, potassium myristoyl glycinate, sodium myristoyl glycinate, sodium palmitoyl glycinate, sodium palmitoyl methylglycinate, potassium coconut oil fatty acid acylglycinate, sodium coconut oil fatty acid acylglycinate, potassium cocoyl glycinate, sodium cocoyl glycinate; alanine derivative salts such as potassium lauroyl methylalanine, sodium lauryl methylalanine, sodium myristoyl methylalanine, sodium cocoyl alanine, sodium coconut oil fatty acid methylalanine; aspartic acid derivative salts such as potassium lauroyl aspartate, sodium lauroyl aspartate, potassium myristoyl aspartate, sodium myristoyl aspartate, potassium palmitoyl aspartate, sodium palmitoyl aspartate, potassium stearoyl aspartate, sodium stearoyl aspartate;Examples include taurine derivative salts such as sodium lauroyl taurate, potassium lauroyl taurate, sodium lauroyl methyl taurate, potassium myristoyl taurate, sodium myristoyl taurate, sodium myristoyl methyl taurate, potassium palmitoyl taurate, sodium palmitoyl taurate, potassium palmitoyl methyl taurate, sodium palmitoyl methyl taurate, potassium stearoyl taurate, sodium stearoyl taurate, and sodium stearoyl methyl taurate; and amino acid derivative salts having hydrocarbon groups, such as proline derivative salts such as sodium lauroyl proline, sodium myristoyl proline, and sodium palmitoyl proline. N-acyl derivative salts of amino acids are particularly preferred. Among these, sarcosine derivative salts of lauric acid, myristic acid, or palmitic acid, and glutamic acid derivative salts of lauric acid, myristic acid, palmitic acid, or stearic acid are best from the viewpoint of melting temperature and safety for the human body.

[0037] The sulfonate salt is preferably one having a monovalent hydrocarbon group with 12 to 20 carbon atoms. Furthermore, the sulfonate salt is preferably a monovalent salt, and more preferably an ammonium salt or a monovalent metal salt. Specific examples include alkyl sulfonates such as sodium lauryl sulfonate, ammonium lauryl sulfonate, sodium myristyl sulfonate, ammonium myristyl sulfonate, sodium cetyl sulfonate, ammonium cetyl sulfonate, sodium stearyl sulfonate, ammonium stearyl sulfonate, sodium oleyl sulfonate, and ammonium oleyl sulfonate; dodecylbenzenesulfonates such as ammonium dodecylbenzenesulfonate and sodium dodecylbenzenesulfonate; monoalkyl succinate sulfonates such as disodium monoalkyl succinate sulfonates with 12 to 20 carbon atoms; naphthalene sulfonate formalin condensate salts such as sodium naphthalene sulfonate formalin condensate; and olefin sulfonates with 12 to 20 carbon atoms such as sodium tetradecene sulfonate and ammonium tetradecene sulfonate. Examples include isethionates such as potassium lauroyl isethionate, sodium lauroyl isethionate, sodium myristoyl isethionate, sodium palmitoyl isethionate, and sodium stearoyl isethionate; and sulfosuccinates such as sodium dihexyl sulfosuccinate, sodium dioctyl sulfosuccinate, ammonium dioctyl sulfosuccinate, sodium didecyl sulfosuccinate, and sodium diisobutyl sulfosuccinate. Of these, sulfonates having an alkyl group with 12 to 20 carbon atoms are particularly preferred.

[0038] Examples of the sulfate ester salts include alkyl sulfate ester salts, polyoxyethylene aryl ether sulfate ester salts, polyoxyethylene alkyl ether sulfate ester salts, polyoxyalkylene alkyl ether sulfate ester salts, polyoxyalkylene alkenyl ether sulfate salts, and polyoxyethylene castor oil ether sulfate ester salts. Furthermore, the sulfate ester salt is preferably a monovalent salt, and more preferably an ammonium salt or a monovalent metal salt.

[0039] Specifically, the alkyl sulfate ester salt is preferably one having an alkyl group with 12 to 20 carbon atoms. Specific examples include potassium lauryl sulfate, sodium lauryl sulfate, ammonium lauryl sulfate, potassium myristyl sulfate, sodium myristyl sulfate, ammonium myristyl sulfate, sodium cetyl sulfate, ammonium cetyl sulfate, sodium stearyl sulfate, ammonium stearyl sulfate, sodium oleyl sulfate, and ammonium oleyl sulfate.

[0040] The polyoxyethylene aryl ether sulfate salts mentioned above are preferably those with an HLB value of 16 or less, and more preferably those with an HLB value of 12 or less. Specific examples include polyoxyethylene polycyclic phenyl ether sulfate salts such as sodium polyoxyethylene polycyclic phenyl ether sulfate and ammonium polyoxyethylene polycyclic phenyl ether sulfate; and sodium polyoxyethylene aryl ether sulfate.

[0041] As for polyoxyethylene alkyl ether sulfate salts, those with an HLB value of 16 or less are preferred, and those with an HLB value of 12 or less are more preferred. Specific examples include polyoxyethylene alkyl ether sulfate, polyoxyethylene lauryl ether sulfate sodium, polyoxyethylene lauryl ether sulfate ammonium, polyoxyethylene myristyl ether sulfate sodium, polyoxyethylene myristyl ether sulfate ammonium, polyoxyethylene cetyl ether sulfate sodium, polyoxyethylene cetyl ether sulfate ammonium, polyoxyethylene stearyl ether sulfate sodium, polyoxyethylene stearyl ether sulfate ammonium, polyoxyethylene oleyl ether sulfate sodium, and polyoxyethylene oleyl ether sulfate ammonium.

[0042] The polyoxyalkylene alkyl ether sulfate salts are preferably those with an HLB value of 16 or less, and more preferably those with an HLB value of 12 or less. Specific examples include sodium sulfate salts of polyoxyethylene-polyoxypropylene block copolymers, sodium sulfate salts of polyoxyethylene-polyoxybutylene block copolymers, and sodium sulfate salts of alkyl ethers of polyoxyethylene-polyoxypropylene block copolymers. The polyoxyalkylene alkenyl ether sulfate salts are preferably those with an HLB value of 16 or less, and more preferably those with an HLB value of 12 or less. Specific examples include ammonium sulfate salts of alkenyl ethers of polyoxyethylene-polyoxyalkylene block copolymers. The polyoxyethylene castor oil ether sulfate and its salts are preferably those with an HLB value of 16 or less, and more preferably those with an HLB value of 12 or less. Specific examples include polyoxyethylene castor oil ether sulfate and ammonium sulfate of polyoxyethylene castor oil ethers.

[0043] Examples of the phosphate salt include alkyl phosphate salts. The alkyl phosphate salt preferably has an alkyl group with 12 to 20 carbon atoms. Specific examples thereof include decyl phosphate salts such as potassium decyl phosphate; undecyl phosphate salts such as potassium undecyl phosphate; lauryl phosphate salts such as potassium lauryl phosphate; myristyl phosphate salts such as potassium myristyl phosphate; cetyl phosphate salts such as potassium cetyl phosphate and sodium cetyl phosphate; stearyl phosphate salts such as potassium stearyl phosphate, and the like.

[0044] In addition to the above-mentioned ones, as the starting compound A, a compound composed of an anion having a structure in which a monovalent anionic substituent selected from carboxylic acid anions (-COO - ), sulfonic acid anions (-SO3 - ), sulfate anions (-O-SO3 - ), and phosphate anions (-P(=O)(OH)-O - ) is introduced into a compound having an active functional group via a linking group and a monovalent cation can also be used. In the present invention, the active functional group means a functional group capable of undergoing a condensation reaction such as a hydroxy group, an amino group, a carboxy group, etc.

[0045] As the compound having the active functional group, compounds having a hydroxy group such as monohydric alcohols, monovalent amino compounds, (poly)alkylene glycol ethers, (poly)alkylene glycol esters, etc. are preferable. Further, as the monovalent anionic substituent introduced into the compound having the active functional group, -COO - is preferable because the introduction is easy.

[0046] The monohydric alcohol is an alcohol having a monohydric hydrocarbon group with 10 to 25 carbon atoms and one hydroxyl group, with those having 12 to 20 carbon atoms being more preferable. The monohydric alcohol may be linear, branched, or cyclic, but linear is preferred. Specific examples of the monohydric alcohol include hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, henicosanol, docosanol, tricosanol, tetracosanol, pentacosanol, hexacosanol, heptacosanol, octacosanol, nonacosanol, triacontanol, and the like.

[0047] The monovalent amino compound is a compound having a monovalent hydrocarbon group with 10 to 25 carbon atoms and one amino group, with those having 12 to 20 carbon atoms being more preferred. The monovalent amino compound may be linear, branched, or cyclic, but linear is more preferred. Specific examples include aminohexane, aminoheptane, aminooctane, aminononane, aminodecane, aminoundecane, aminododecane, aminotridecane, aminotetradecane, aminopentadecane, aminohexadecane, aminoheptadecane, aminooctadecane, aminononadecane, and aminoicosane.

[0048] The (poly)alkylene glycol ether is preferably one with an HLB value of 16 or less, more preferably one with an HLB value of 12 or less, and even more preferably one with an HLB value of 8 or less. Specific examples include (poly)alkylene glycol monoalkyl ethers such as (poly)ethylene glycol monododecyl ether, (poly)ethylene glycol monomyristyl ether, (poly)ethylene glycol monocetyl ether, (poly)ethylene glycol monostearyl ether, (poly)ethylene glycol monooleyl ether, (poly)ethylene glycol monobehenyl ether, (poly)propylene glycol monododecyl ether, (poly)propylene glycol monomyristyl ether, (poly)propylene glycol monocetyl ether, (poly)propylene glycol monostearyl ether, (poly)propylene glycol monooleyl ether, and (poly)propylene glycol monobehenyl ether; and (poly)alkylene glycol monoaryl ethers such as (poly)ethylene glycol monophenyl ether and (poly)propylene glycol monophenyl ether.

[0049] The (poly)alkylene glycol esters mentioned above are preferably those with an HLB value of 16 or less, more preferably those with an HLB value of 12 or less, and even more preferably those with an HLB value of 8 or less. Specific examples include polyalkylene glycol monofatty acid esters such as (poly)ethylene glycol monolaurate, (poly)ethylene glycol monomyristate, (poly)ethylene glycol monopalmitate, (poly)ethylene glycol monostearate, (poly)ethylene glycol monooleate, (poly)ethylene glycol monoisostearate, (poly)ethylene glycol monoarachidicate, (poly)ethylene glycol monobehenate, (poly)propylene glycol monolaurate, (poly)propylene glycol monomyristate, (poly)propylene glycol monopalmitate, (poly)propylene glycol monostearate, (poly)propylene glycol monooleate, (poly)propylene glycol monoisostearate, (poly)propylene glycol monoarachidicate, and (poly)propylene glycol monobehenate. Examples include polyalkylene sorbitan monofatty acid esters such as (poly)ethylene sorbitan monolaurate, (poly)ethylene sorbitan monomyristate, (poly)ethylene sorbitan monopalmitate, (poly)ethylene sorbitan monostearate, (poly)ethylene sorbitan monooleate, (poly)ethylene sorbitan monoisostearate, (poly)ethylene sorbitan monoarachidicate, (poly)ethylene sorbitan monobehenate, (poly)propylene sorbitan monolaurate, (poly)propylene sorbitan monomyristate, (poly)propylene sorbitan monopalmitate, (poly)propylene sorbitan monostearate, (poly)propylene sorbitan monooleate, (poly)propylene sorbitan monoisostearate, (poly)propylene sorbitan monoarachidicate, and (poly)propylene sorbitan monobehenate.

[0050] The number average molecular weight (Mn) of the polyalkylene glycol ether and (poly)alkylene glycol ester is preferably in the following order of lower limit: 100 or more, 300 or more, 400 or more, and 500 or more, and in the following order of upper limit: 10,000 or less, 6,000 or less, 4,000 or less, 3,000 or less, and 2,000 or less.

[0051] A method for introducing a monovalent anionic substituent to the compound having the active functional group is, for example, -COO - When introducing the active functional group, methods include esterifying the compound having the active functional group with a divalent carboxylic acid anhydride in the presence of a monovalent metal salt, or reacting these with a monovalent metal to form a metal alkoxide, and then esterifying it with a divalent carboxylic acid anhydride. Preferred divalent carboxylic acid anhydrides are succinic anhydride, maleic anhydride, and phthalic anhydride, with succinic anhydride and maleic anhydride being more preferred considering biodegradability. Also, for example, -SO3 - When introducing the active functional group, one method involves reacting a compound having a hydroxyl group or an amino group as the active functional group with SO3 or an SO3-Lewis base complex in an aprotic polar solvent. Examples of Lewis bases include tertiary amines, pyridine, and DMF. Acetonitrile is preferred as the aprotic polar solvent. These reactions can be carried out by known methods.

[0052] Specifically, the hydrophobic compounds include metal soaps such as calcium laurate, magnesium laurate, aluminum laurate, calcium myristate, magnesium myristate, aluminum myristate, calcium palmitate, magnesium palmitate, aluminum palmitate, calcium stearate, magnesium stearate, aluminum stearate, calcium ricinoleate, magnesium ricinoleate, aluminum ricinoleate; calcium myristoyl sarcosinate, magnesium myristoyl sarcosinate, aluminum myristoyl sarcosinate, calcium myristoyl glutamate, myristoyl glutamate, and others; calcium myristoyl sarcosinate, magnesium myristoyl sarcosinate, aluminum myristoyl sarcosinate, calcium myristoyl glutamate, and myristoyl glutamate. N-acyl amino acid derivative salts such as magnesium glutamate, aluminum myristoyl glutamate, calcium stearoyl glutamate, magnesium stearoyl glutamate, and aluminum stearoyl glutamate; sulfonates such as calcium dodecanesulfonate, magnesium dodecanesulfonate, and aluminum dodecanesulfonate; salt compounds obtained from esterifying propyl glycol monostearate and succinic anhydride in the presence of a sodium salt and a calcium salt; salt compounds obtained from esterifying stearyl alcohol and succinic anhydride in the presence of a sodium salt and a calcium salt are preferred.

[0053] [Method for producing hydrophobic compounds] The following methods (1) and (2) are examples of methods for producing the hydrophobic compound. (1) A method comprising the steps of forming a W / O emulsion containing one type of raw material compound A in a water droplet and performing a bonding treatment using a polyvalent metal salt (Method 1). (2) A method of adding a solution of a polyvalent metal salt dropwise to a medium in which one type of raw material compound A dissolves, and precipitating or precipitation while performing a bonding treatment, or a method of adding a solution in which one type of raw material compound A dissolves dropwise to a medium in which a polyvalent metal salt dissolves, and precipitating or precipitation while performing a bonding treatment (Method 2).

[0054] Method 1 is a method that includes the steps of forming a W / O emulsion containing one type of starting compound A in a water droplet and performing an ionic bonding treatment using a polyvalent metal salt.

[0055] An example of a method for forming a W / O emulsion is described below. First, a solution is prepared by dissolving one type of starting compound A in water or a mixed solvent of water and a hydrophilic organic solvent. Heating may be performed at this time if necessary. Next, the solution is mixed with a hydrophobic organic solvent and emulsified using a stirrer or homogenizer. When mixing, the solution may be added to the hydrophobic organic solvent, or the hydrophobic organic solvent may be added to the solution. At this time, a surfactant or polymer stabilizer may be dissolved in the hydrophobic organic solvent and used to control the particle size of water droplets in the W / O emulsion.

[0056] Another example of a method for forming a W / O emulsion is to put one type of raw material compound A, a hydrophobic agent, water, a surfactant, a hydrophobic organic solvent, and other necessary components into a container and emulsify them using a stirring device or homogenizer.

[0057] Heating may be performed when forming the W / O emulsion. Heating can increase the solubility, thereby homogenizing the starting compound A and stabilizing the W / O emulsion. The heating temperature is preferably 15 to 100°C, and more preferably 40 to 80°C.

[0058] After forming the W / O emulsion, an ionic bonding treatment is performed. The bonding treatment can be carried out by adding a solution containing a polyvalent metal salt to the W / O emulsion and stirring. Alternatively, the W / O emulsion may be added to the solution containing the polyvalent metal salt and stirred.

[0059] Examples of the aforementioned polyvalent metal salts include calcium salts, strontium salts, magnesium salts, barium salts, radium salts, lead salts, zinc salts, nickel salts, iron salts, copper salts, cadmium salts, cobalt salts, and manganese salts. However, calcium salts and magnesium salts are preferred due to their presence in seawater, environmental impact, safety, and versatility. Specific examples of the aforementioned polyvalent metal salts include calcium chloride, calcium sulfate, calcium carbonate, calcium hydroxide, calcium oxide, magnesium chloride, magnesium sulfate, magnesium carbonate, magnesium hydroxide, and magnesium oxide. However, calcium chloride and magnesium chloride are preferred due to their solubility in water, ease of handling, and cost.

[0060] The concentration of the polyvalent metal salt in the solution containing the polyvalent metal salt is preferably 1 to 40% by mass, and more preferably 10 to 30% by mass. The solvent of the solution is preferably water; a lower alcohol solvent such as methanol, ethanol, 1-propanol, 2-propanol, or a mixture thereof; however, a mixture of other organic solvents is also acceptable as long as the salt can be dissolved to the desired concentration without dissolving the particles.

[0061] The bonding treatment may be carried out with heating as needed. Heating may be performed when adding the solution containing the polyvalent metal salt to the dispersion, when stirring after addition, or both. The heating temperature is preferably 10 to 100°C, and more preferably 40 to 80°C. The treatment time is preferably 0.5 to 24 hours, and more preferably 1 to 12 hours. Heating can increase the solubility of the hydrophobic agent.

[0062] Since the aqueous phase of the W / O emulsion contains one type of raw material compound A and a hydrophobic agent, the bonding treatment also performs the hydrophobic treatment simultaneously.

[0063] After the bonding treatment, a group of particles consisting of hydrophobic compounds can be obtained by washing and drying the particles as needed. Washing can be carried out by conventional methods, such as removing the solvent after the bonding treatment, adding water, and centrifuging. Drying can be carried out by conventional methods, such as spray drying, vacuum drying, or freeze-drying. The obtained group of hydrophobic compound particles may be subjected to surface treatment or grinding treatment to adjust the particle size using known equipment as needed.

[0064] Method 2 is a method in which a solution of a polyvalent metal salt is added dropwise to a medium in which one type of raw material compound A is dissolved, and precipitates or settles while performing a binding treatment, or a method in which a solution in which raw material compound A is dissolved is added dropwise to a medium in which a polyvalent metal salt is dissolved, and precipitates or settles while performing a binding treatment.

[0065] An example of Method 2 is described below. First, solution A is prepared by dissolving one type of raw material compound A in water or a mixed solvent of water and a hydrophilic organic solvent. At this time, heating may be done as necessary to improve solubility. Next, solution B containing a polyvalent metal salt is added and stirred. Alternatively, a solution in which one type of raw material compound A is dissolved in a solution containing a polyvalent metal salt may be added and stirred. The solution containing the polyvalent metal salt can be the same as that described in the explanation of Method 1.

[0066] This process allows for bonding, and the target hydrophobic compound, which gradually becomes insoluble, precipitates or settles. The treatment time is preferably 0.5 to 24 hours, and more preferably 1 to 12 hours.

[0067] In this case, a surfactant or polymer stabilizer may be dissolved in at least one of solutions A and B for the purpose of controlling the particle size of the precipitate or sediment.

[0068] Heating may be performed when precipitating or precipitation the target hydrophobic compound. Heating may be performed when mixing solution A and solution B, when stirring after mixing, or both. Heating can increase the solubility of raw material compound A, thereby enabling polymerization through bonding and homogenizing the molecular weight distribution, and stabilizing the bonds. The heating temperature is preferably 15 to 100°C, and more preferably 40 to 80°C.

[0069] After processing, hydrophobic compound particles can be obtained by washing and drying the particles as needed. Washing can be carried out by conventional methods, such as removing the solvent after the bonding treatment and adding water and centrifuging. Drying can be carried out by conventional methods, such as spray drying, vacuum drying, or freeze-drying. The obtained group of hydrophobic compound particles may be subjected to surface treatment or pulverization to adjust the particle size using known equipment as needed.

[0070] [Resin composition] By using the marine biodegradation accelerator of the present invention in combination with a resin, particularly a biodegradable resin, a resin composition that promotes biodegradation in the ocean can be obtained. Furthermore, multiple types of resins can be used in combination to adjust the physical properties and handling characteristics of the resin composition. Here, a biodegradable resin refers to a resin that is decomposed by the action of microorganisms in nature and ultimately broken down into inorganic substances such as water and carbon dioxide.

[0071] Resins that can be combined with the marine biodegradation accelerator of the present invention include polyethylene, polyester, polypropylene, polyethylene terephthalate, vinyl chloride, polystyrene, polyurethane, epoxy resin, chlorinated polyethylene resin, chlorinated polypropylene resin, modified nylon resin, phenolic resin, silicone resin, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, styrene-maleic acid resin, styrene-butadiene resin, butadiene resin, acrylonitrile-butadiene resin, poly(meth)acrylonitrile resin, (meth)acrylamide resin, bioPET, biopolyamide, biopolycarbonate, biopolyurethane, polyvinyl alcohol, polybutylene adipate / terephthalate, polyethylene terephthalate succinate, biopolybutylene succinate, polylactic acid blend, starch blend, polyester resin, polybutylene terephthalate succinate, polylactic acid, polyhydroxyalkanoic acid, etc. However, considering the reduction of environmental impact, resins with particularly high biodegradability are preferred.

[0072] Furthermore, the biodegradable resins include polycaprolactone, poly(caprolactone / butylene succinate), polybutylene succinate (PBS), poly(butylene succinate / adipate) (PBSA), poly(butylene adipate / terephthalate) (PBAT), poly(butylene succinate / carbonate), polyethylene terephthalate copolymer, poly(ethylene terephthalate / succinate), and poly(tetramethylene adipate / terephthalate). The raw materials include polyethylene succinate, polyvinyl alcohol, polyglycolic acid, glycolic acid / caprolactone copolymer, etc., which are petroleum-derived resins; (polylactic acid / polybutylene succinate) block copolymer, (polylactic acid / polycaprolactone) copolymer, (polylactic acid / polyether) copolymer, polylactic acid blend PBAT, lactic acid / glycolic acid copolymer, biopolybutylene succinate, poly(butylene succinate / adipate), starch blend Examples include resins made from partially biomass-derived raw materials such as polyester resin and poly(butylene terephthalate succinate); polyhydroxyalkanoates such as polyhydroxybutyrate, polyhydroxyvaleric acid, polyhydroxycaprylic acid, poly(hydroxybutyrate / hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate / 4-hydroxybutyrate) (P3HB4HB), and poly(hydroxybutyrate / hydroxyvaleric acid) (PHBV); and resins made from 100% biomass-derived raw materials such as polylactic acid (PLA); and resins made from natural polymers such as cellulose, cellulose acetate, cellulose ester resin, starch, esterified starch, and chitosan.

[0073] Of these, it is preferable to combine a biodegradable resin component selected from resins that are biodegradable in soil or compost but have poor biodegradability in the ocean, such as polycaprolactone, (bio)PBS, PBSA, PBAT, poly(tetramethylene adipate / terephthalate), poly(butylene succinate / carbonate), PHBH, PHBV and other polyhydroxyalkanoates, PLA, cellulose, starch, chitosan and other resins derived from natural polymers, with the marine biodegradation accelerator. Among these, PBSA, PBS, PBAT, PLA and starch-derived resins are particularly preferred as the biodegradable resin.

[0074] Particularly preferred combinations of the marine biodegradation accelerator and biodegradable resin of the present invention include calcium palmitate, calcium stearate, calcium myristoyl sarcosinate, calcium palmitoyl sarcosinate, and calcium stearoyl glutamate as the marine biodegradation accelerator, and one or more selected from PBSA, PBS, PBAT, and starch-derived resins as the biodegradable resin.

[0075] Furthermore, considering the reduction of environmental impact, the raw materials for the resin to be combined are preferably biomass-derived, more preferably 25% or more are biomass-derived, even more preferably 50% or more are biomass-derived, and most preferably 80% or more are biomass-derived.

[0076] The resin composition of the present invention may contain a solvent. The solvent may dissolve the resin matrix while leaving the marine biodegradation accelerator undissolved as particles, or it may dissolve both the resin and the marine biodegradation accelerator. By adjusting these as appropriate, the composition can be used as a molded body formed by film formation through casting, or as a paint, ink, surface treatment agent, etc. Preferred solvents include, for example, water, hexane, heptane, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dimethyl sulfone, acetone, methyl ethyl ketone, diethyl ketone, acetophenone, dimethyl ether, dipropyl ether, tetrahydrofuran, chloroform, methylene chloride, trichloroethylene, dichloroethylene, dichloroethane, tetrachloroethane, chlorobenzene, methanol, ethanol, n-propanol, isopropanol, butanol, pentanol, methyl glycol, methyl triglyceride, hexyl glycol, phenyl glycol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, benzene, toluene, xylene, and the like. These may be used individually or in combination of two or more.

[0077] When a solvent is used, the total concentration of the resin and marine biodegradation accelerator in the resin composition is preferably 0.5 to 90% by mass, more preferably 1 to 80% by mass, even more preferably 5 to 60% by mass, and most preferably 10 to 50% by mass. Furthermore, the ratio of marine biodegradation accelerator to resin by mass is preferably 99:1 to 10:90, more preferably 97:3 to 40:60, even more preferably 95:5 to 50:50, and most preferably 90:10 to 60:40.

[0078] Furthermore, the resin composition of the present invention does not need to contain a solvent. In this case, the resin may be heated and melted, and a non-melting marine biodegradation accelerator may be added and mixed thereto, or the resin and the marine biodegradation accelerator may be melted together and mixed.

[0079] In the resin composition of the present invention, the content of the marine biodegradation accelerator is 1 to 50% by mass, and the content of the resin is 50 to 99% by mass. However, in order to efficiently exert the effect of the marine biodegradation accelerator of the present invention, the content of the marine biodegradation accelerator is more preferably 3 to 50% by mass, even more preferably 5 to 45% by mass, still more preferably 7 to 40% by mass, and most preferably 10 to 35% by mass. On the other hand, the resin content is more preferably 50 to 97% by mass, even more preferably 55 to 95% by mass, still more preferably 40 to 93% by mass, and most preferably 65 to 90% by mass. By including the marine biodegradation accelerator within the above range, it can be used as a marine biodegradation accelerator that promotes the progression of biodegradation in seawater while maintaining the physical properties of the biodegradable resin.

[0080] The resin composition of the present invention may optionally contain additives such as antioxidants, mold release agents, release agents, surface modifiers, hydrophobic agents, water-repellent agents, hydrophilic agents, dyes and pigments, colorants, heat stabilizers, light stabilizers, weather resistance improvers, antistatic agents, antifogging agents, lubricants, antiblocking agents, hardening agents, softening agents, compatibilizers, flame retardants, flow improvers, plasticizers, dispersants, antibacterial agents, fillers, and metal deactivators. The content of these additives is not particularly limited as long as it does not impair the effects of the present invention, but it is preferably about 0.1 to 50 parts by mass per 100 parts by mass of resin.

[0081] If the resin composition contains a solvent, it can be prepared, for example, by adding the resin, the marine biodegradation accelerator, and the additives as needed to the solvent simultaneously or in any order and mixing them. If the resin composition does not contain a solvent, for example, the resin may be melted, and the marine biodegradation accelerator and the additives as needed may be added simultaneously or in any order and mixed; or the resin and the marine biodegradation accelerator may be heated to melt them together and mixed, and the additives as needed may be added and mixed.

[0082] [Molded body] By molding using the aforementioned resin composition, a molded article can be obtained in which the marine biodegradation accelerator is dispersed or dissolved in the resin. If the resin composition contains a solvent, the resin composition can be used as is for molding; if the resin composition does not contain a solvent, the resin in the resin composition, or the resin and marine biodegradation accelerator, can be melted by heat before molding.

[0083] Examples of the shape of the molded article include film-like, fibrous, plate-like, foamed molded article-like, and other shapes depending on the application. The molding method is not particularly limited, and various conventionally known molding methods can be used. Specific examples include blow molding, injection molding, extrusion molding, compression molding, melt extrusion molding, solution casting molding, and calendering. [Examples]

[0084] The present invention will be described in more detail below with reference to manufacturing examples, examples, and comparative examples, but the present invention is not limited to the following examples. In the following examples and comparative examples, the particle size distribution and volume average particle diameter (MV) were measured using a MICROTRACK MT3000 (manufactured by Microtrac-Bell Co., Ltd.).

[0085] [Synthesis Example 1] Preparation of Propylene Glycol Monostearate Derivative A In a 2,000 mL reaction vessel, add monostearic acid propylene 240.0 g of glycol, 77.2 g of succinic anhydride, 83.7 g of sodium carbonate, and 500.0 g of acetonitrile were charged and stirred at 60°C for 4 hours. After stirring, the mixture was cooled to room temperature and the precipitate was removed by filtration. The resulting filtrate was concentrated using an evaporator, and the solvent was further removed under reduced pressure to obtain monostearate with one end replaced with -COONa. propylene Glycol derivative A was produced.

[0086] [Synthesis Example 2] Preparation of Stearyl Alcohol Derivative B In a 2,000 mL reaction vessel, 150.0 g of stearyl alcohol, 61.1 g of succinic anhydride, 64.6 g of sodium carbonate, and 500.0 g of acetonitrile were charged and stirred at 60°C for 4 hours. After stirring, the mixture was cooled to room temperature and the precipitate was removed by filtration. The resulting filtrate was concentrated using an evaporator, and the solvent was further removed under reduced pressure to obtain a stearyl alcohol derivative with one end substituted with -COONa. B They manufactured it.

[0087] [Example 1-1] Production of calcium palmitate particle group (particle group A1) The following components were placed in a 5,000 mL reaction vessel and stirred with a stirrer at 70°C until dissolved. Potassium palmitate 250.0g Ion-exchanged water 2,875.0g

[0088] Subsequently, 1000.0 g of a 20.0% by mass calcium chloride aqueous solution was added dropwise while stirring to carry out a calcium substitution reaction and precipitate particles. After stirring was complete, the particles were repeatedly filtered and washed with deionized water and dried to obtain the target particle group A1. Particle group A1 was observed by SEM and its shape was confirmed to be a flaky particle group. The MV of particle group A1 was 58 μm.

[0089] [Examples 1-2] Production of Myristoyl Sarcosinate Calcium Particle Group (Particle Group A2) The following components were placed in a 5,000 mL reaction vessel and stirred with a stirrer at 60°C until dissolved. Myristoyl sarcosin sodium 250.0g Ion-exchanged water 2,250.0g

[0090] Subsequently, 1000.0 g of a 20.0% by mass calcium chloride aqueous solution was added dropwise while stirring to carry out a calcium substitution reaction and precipitate particles. After stirring was complete, the particles were repeatedly filtered and washed with deionized water and dried to obtain the target particle group A2. Particle group A2 was observed by SEM and its shape was confirmed to be a flaky particle group. The MV of particle group A2 was 96 μm.

[0091] [Examples 1-3] Production of calcium myristoyl glutamate particles (particle group A3) The following components were placed in a 5,000 mL reaction vessel and stirred with a stirrer at 60°C until dissolved. Sodium myristoyl glutamate 70.0g Ion-exchanged water 2,730.0g

[0092] Subsequently, 350.0 g of a 15.0% by mass calcium chloride aqueous solution was added dropwise while stirring to carry out a calcium substitution reaction and precipitate particles. After stirring was complete, the particles were repeatedly filtered and washed with deionized water and dried to obtain the target particle group A3. Particle group A3 was observed by SEM and its shape was confirmed to be a flaky particle group. The MV of particle group A3 was 79 μm.

[0093] [Examples 1-4] Production of magnesium dodecanesulfonate particle group (particle group A4) The following components were placed in a 3,000 mL reaction vessel and stirred with a stirrer at 40°C until dissolved. Sodium dodecanesulfonate 150.0g Ion-exchanged water 600.0g

[0094] Subsequently, 1000.0 g of a 20.0 mass% magnesium chloride aqueous solution was added dropwise while stirring to carry out the magnesium substitution reaction and precipitate particles. After stirring was complete, the particles were repeatedly filtered and washed with deionized water and dried to obtain the target particle group A4. Particle group A4 was observed by SEM and its shape was confirmed to be a flaky particle group. The MV of particle group A4 was 41 μm.

[0095] [Examples 1-5] Production of aluminum myristate particle group (particle group A5) The following components were placed in a 5,000 mL reaction vessel and stirred with a stirrer at 50°C until dissolved. Sodium myristate 250.0g Ion-exchanged water 2,875.0g

[0096] Subsequently, 1250.0 g of a 10.0 mass% aluminum sulfate aqueous solution was added dropwise while stirring to carry out the aluminum substitution reaction and precipitate particles. After stirring was complete, the particles were repeatedly filtered and washed with deionized water and dried to obtain the target particle group A5. Particle group A5 was observed by SEM and its shape was confirmed to be a flake-like particle group. The MV of particle group A5 was 68 μm.

[0097] [Examples 1-6] Production of calcium particle group (particle group A6) derived from propylene glycol monostearate The following components were placed in a 3,000 mL reaction vessel and stirred with a stirrer at 60°C until dissolved. Propylene glycol monostearate derivative A 120.0g Ion-exchanged water 1,104.0g Ethanol 276.0g

[0098] Subsequently, 600.0 g of a 20.0 mass% calcium chloride aqueous solution was added dropwise while stirring to carry out a calcium substitution reaction and precipitate particles. After stirring was complete, the particles were repeatedly filtered and washed with deionized water and dried to obtain the target particle group A6. Particle group A6 was observed by SEM and its shape was confirmed to be a flaky particle group. The MV of particle group A6 was 164 μm.

[0099] [Examples 1-7] Production of stearyl alcohol derivative calcium particle group (particle group A7) The following components were placed in a 3,000 mL reaction vessel and stirred with a stirrer at 75°C until dissolved. Stearyl alcohol derivative B 100.0g Ion-exchanged water 1,140.0g Ethanol 760.0g

[0100] Subsequently, 666.7 g of a 15.0% by mass calcium chloride aqueous solution was added dropwise while stirring to carry out the calcium substitution reaction and precipitate particles. After stirring was complete, the particles were repeatedly filtered and washed with deionized water and dried to obtain the target particle group A7. Particle group A7 was observed by SEM and its shape was confirmed to be a flaky particle group. The MV of particle group A7 was 147 μm.

[0101] [Comparative Example 1-1] Production of polymethyl methacrylate (PMMA) particle group (particle group B1) Each of the components listed below was charged together into a 2,000 mL flask, and a group of single spherical polymer particles B1 of PMMA with an MV of 5 μm was prepared using the same method as Comparative Examples 1-3 in International Publication No. 2016 / 181877. Water 1,386.5g Methyl methacrylate 173.4g Lauryl peroxide 8.6g Polyvinylpyrrolidone (K-30) 17.3g

[0102] [Comparative Example 1-2] Production of polystyrene (PS) particle group (particle group B2) The compounds listed below were charged together in a 2,000 mL flask, and a suspension was prepared using a disperser vane at 1,000 rpm. The resulting suspension was stirred at 80°C for 8 hours under a nitrogen stream using an oil bath to obtain a PS particle dispersion. Water 1,280.0g Styrene 288.0g Lauryl peroxide 14.2g Polyvinylpyrrolidone (K-30) 21.6g

[0103] The obtained particle dispersion was transferred to a 3,000 mL flask through a sieve with a mesh size of 200 μm. Next, the particle dispersion that had passed through the sieve was subjected to centrifugation, and this was repeated five times to perform classification and washing operations, yielding a group of single spherical polymer particles B2 with an MV of 10 μm.

[0104] [Comparative Examples 1-3] Production of polybutylene succinate (PBS) particle group (particle group B3) 30.0 g of pellets of biodegradable resin (PBS, FZ-91 manufactured by Mitsubishi Chemical Corporation) were frozen with liquid nitrogen and then pulverized using a pulverizer (Wonder Blender WB-1 manufactured by Osaka Chemical Co., Ltd.). Next, the particle size was adjusted by sieving. By repeating this process, a single PBS particle group B3 with an MV of 10 μm was obtained.

[0105] [Comparative Example 1-4] Production of polybutylene succinate adipate (PBSA) particle group (particle group B4) 30.0 g of pellets of biodegradable resin (PBSA, FD-9 manufactured by Mitsubishi Chemical Corporation) were frozen with liquid nitrogen and then pulverized using a pulverizer (Wonder Blender WB-1 manufactured by Osaka Chemical Co., Ltd.). Next, the particle size was adjusted by sieving. By repeating this process, a group of single PBSA particles B4 with an MV of 5 μm was obtained.

[0106] [Comparative Examples 1-5] Calcium alginate particle group (Particle group B5) Spherical calcium alginate beads (manufactured by Nisshinbo Chemical Co., Ltd.: product name Flavicafine, MV=20μm) were designated as particle group B5.

[0107] [ 1 Measurement of basic physical properties [Examples 2-1 to 2-7, Comparative Examples 2-1 to 2-5] The melting temperature and contact angle of each marine biodegradation accelerator were measured using the method described below. The results are shown in Table 1.

[0108] [Measurement of melting temperature] Measurements were performed using a differential scanning calorimeter (DSC6200, manufactured by Seiko Instruments Inc.). Specifically, 10 mg of the sample was accurately weighed, placed in an aluminum pan, and an empty aluminum pan was used as a reference. The sample was heated at a rate of 10°C / min within the measurement temperature range of 20 to 200°C under normal temperature and humidity conditions. The glass transition temperature (Tg) was calculated from the obtained reversing heat flow curve. In this process, the midpoint of the line connecting the intersection points of the baseline and the endothermic curve was determined and defined as Tg. The endothermic (melting) peak point of the obtained curve was calculated as the melting temperature.

[0109] [Measuring contact angle] Each particle group was formed using a hot press set to a temperature above its respective melting temperature to produce a film with a thickness of 200 μm. Then, in accordance with JIS R 3257, pure water was dropped onto the surface of the prepared film, and the contact angle of the pure water was measured using a contact angle meter (Drop Master 300, manufactured by Kyowa Interface Science Co., Ltd.).

[0110] [Table 1]

[0111] [ 2 Solubility Test-1 [Examples 3-1 to 3-7, Comparative Examples 3-1 to 3-5] Each particle group (1.0 g) was dispersed in water or a sodium chloride aqueous solution (3% sodium chloride concentration) to a concentration of 0.1% by mass, and a solubility test was performed. The results are shown in Table 2. (1) Appearance: The condition was visually inspected 15 days after dispersion. (2) Shape: After dispersion in an aqueous sodium chloride solution, the change in shape compared to the shape before the test after 15 days was confirmed by particle size distribution measurement. (3) Transmittance: Each particle group was dispersed in an aqueous sodium chloride solution, and the transmittance of the dispersion at a wavelength of 560 nm after 15 days was defined as SD1 (%). Each particle group was then dispersed in water, and the transmittance of the dispersion at a wavelength of 560 nm after 24 hours was defined as WD1 (%). WD1 / SD1 was then calculated. Transmittance was measured using a UV-Vis spectrophotometer (Shimadzu Corporation UV-2450). This is shown in Table 1.

[0112] [Table 2]

[0113] [ 3 Solubility Test - 2 [Examples 4-1 to 4-7, Comparative Examples 4-1 to 4-5] 1.0 g of each particle group was dispersed in water and a sodium chloride aqueous solution (sodium chloride concentration 3% by mass) to a concentration of 0.1% by mass, respectively, and stirred at room temperature for 15 days. After that, the mixture was washed by suction filtration with warm water using a membrane filter, and the residue on the filter was dried in a vacuum dryer until a constant weight was reached, and then weighed. The weight before the test was denoted as A, and the weight after drying as B. The weight loss rate ((AB) / A × 100 (%)) was calculated. The weight loss rate in water was denoted as W, and the weight loss rate in sodium chloride aqueous solution was denoted as S. The degree of solubility or hydrophilization Z was calculated using Z = SW. The results are shown in Table 3.

[0114] [Table 3]

[0115] [ 4 Solubility test 1 in resin molded products [Examples 5-1 to 5-7, Comparative Examples 5-1 to 5-5] Biodegradable resin PBSA (FD-92, manufactured by Mitsubishi Chemical Corporation) was mixed with each particle group (particle groups A1-A7, particle groups B1-B5) at 140°C to a concentration of 20 by mass, and then press-molded at 150°C to produce a film with a thickness of 150 μm (Examples 5-1 to 5-6, Comparative Examples 5-1 to 5-4). In addition, PBSA itself (without particle groups) was press-molded at 150°C to produce a film with a thickness of 150 μm (Comparative Example 5-5). The table shows the presence or absence of the shape of each particle group within the film, and the measurement results of the contact angle of the fabricated film. 4 As shown below. Note that the presence or absence of particle shape is observed visually, and the contact angle is "[ 1 The measurements were taken using the method described in "Measurement of Basic Physical Properties". Furthermore, the obtained films were processed into 10 mm squares and placed in 200 mL of deionized water and 200 mL of 3% by mass sodium chloride aqueous solution, respectively. After standing at 25°C for 15 days and 45 days, the films were removed and their surfaces and appearance were observed using a scanning electron microscope. The results are shown in Table 4. Furthermore, SEM images of the film from Example 5-2 after immersion in water for 45 days and after immersion in a 3% by mass sodium chloride aqueous solution for 45 days are shown in Figures 1 and 2, respectively.

[0116] [Table 4]

[0117] [ 5 ] Solubility test for resin molded products 2 [Examples 6-1 to 6-7, Comparative Examples 6-1 to 6-5] Aside from changing the biodegradable resin to PBS (FZ-91 manufactured by Mitsubishi Chemical Corporation), "[ 4 Test films were prepared using the same method as in "Solubility Test 1 in Resin Molded Products" (Examples 6-1 to 6-7, Comparative Examples 6-1 to 6-4). A resin film without particles was also prepared for comparison (Comparative Example 6-5). The table shows the presence or absence of the shape of each particle group within the film, and the measurement results of the contact angle of the fabricated film. 5 As shown below. Note that the presence or absence of particle shape is observed visually, and the contact angle is "[ 1 The measurements were taken using the method described in "Measurement of Basic Physical Properties". The obtained films were processed into 10 mm squares and placed in 200 mL of deionized water and 200 mL of 3% by mass sodium chloride aqueous solution, respectively. After standing at 25°C for 15 days and 45 days, the films were removed and their surfaces and appearance were observed using a scanning electron microscope. The results are shown in Table 5. Furthermore, SEM images of the film from Example 6-3 after immersion in water for 45 days and after immersion in a 3% by mass sodium chloride aqueous solution for 45 days are shown in Figures 3 and 4, respectively.

[0118] [Table 5]

[0119] [ 6 ] Biodegradability test of powders [Examples 7-1 to 7-3, Comparative Examples 7-1 to 7-3] Seawater biodegradation tests were conducted on particle groups A1-A3 and B1-B3 using the following method. Microcrystalline cellulose (Sigma-Aldrich Avicel PH-101) was used as a control material, and the relative biodegradation rate of the cellulose was evaluated. The results are shown in Table 6.

[0120] <Testing methods and conditions> Method for measuring biodegradability: Measurement of oxygen consumption using a closed-loop respirator (refer to ASTM D6691). Test equipment: OxiTop IDS (manufactured by WTW) Culture temperature: 30±1℃, dark place Biodegradation (%)=(BOD O -BOD B ) / ThOD×100 BOD O : Biochemical oxygen demand for testing or confirmation of plant source activity (measured value: mg) BOD B : Average biochemical oxygen demand of a blank test (measured value: mg) ThOD: Required when the test material or control material is completely oxidized. Theoretical oxygen demand (calculated value: mg) Relative biodegradability of cellulose (%) = (Maximum biodegradability of test particles / Maximum biodegradability of cellulose) × 100 Seawater (collected from Tokyo Bay [Chiba Prefecture: Chiba Port]) The collected seawater was filtered to remove impurities using a 10 μm filter, and then aerated at room temperature (25°C). In addition, ammonium chloride (0.05 g / L) and potassium dihydrogen phosphate (0.1 g / L) were added as inorganic nutrients.

[0121] [Table 6]

[0122] The results shown in Table 6 indicate that particle groups A1 to A3 exhibited biodegradability nearly equivalent to that of cellulose up to 56 days of culture.

[0123] [ 7 ]Confirmation test in seawater 1 (weight loss) [Examples 8-1 to 8-10, Comparative Examples 8-1 to 8-6] Using particle groups A1, A2, and B1, each particle group was added to PBSA (FD-92, manufactured by Mitsubishi Chemical Corporation) in amounts of 3% by mass, 5% by mass, 10% by mass, 20% by mass, and 30% by mass, respectively. The mixture was kneaded at 140°C and press-molded at 150°C to produce a film with a thickness of 200 μm. In addition, PBSA itself (without the particle groups) was press-molded at 150°C to produce a film with a thickness of 200 μm as a blank (Comparative Example 8-6). The obtained film was processed into 20mm squares, sandwiched between stainless steel nets, and immersed in seawater (collected from Tokyo Bay [Chiba Prefecture: Chiba Port]) in a 40L tank. The weight loss after immersion was observed after 30, 60, and 90 days. The results are shown in Table 7.

[0124] [Table 7]

[0125] table 7 Based on the results shown, it is thought that biodegradation is promoted by both the breakdown caused by seawater and the presence of microorganisms in the seawater.

[0126] [ 8 Confirmation test 2 in seawater (biodegradability test) [Examples 9-1 to 9-10, Comparative Examples 9-1 to 9-5] [ 7 The films obtained in "Confirmation Test 1 in Seawater" were frozen with liquid nitrogen, then pulverized using a pulverizer (Wonder Blender WB-1 manufactured by Osaka Chemical Co., Ltd.), and various pulverized particles were prepared using a commercially available sieve so that the MV was 10 μm. A seawater biodegradation test was performed on each of the obtained pulverized particles using the following method. PBSA itself (without the particle group) was used as a blank, and the relative biodegradation rate with respect to the blank was used for evaluation. The results are shown in Table 8.

[0127] <Testing methods and conditions> Method for measuring biodegradability: Measurement of oxygen consumption using a closed-loop respirator (refer to ASTM D6691). Test equipment: OxiTop IDS (manufactured by WTW) Culture temperature: 30±1℃, dark place Biodegradation (%)=(BOD O -BOD B ) / ThOD×100 BOD O : Biochemical oxygen demand for testing or confirmation of plant source activity (measured value: mg) BOD B : Average biochemical oxygen demand of a blank test (measured value: mg) ThOD: Required when the test material or control material is completely oxidized. Theoretical oxygen demand (calculated value: mg) Relative biodegradability of cellulose (%) = (Maximum biodegradability of test particles / Maximum biodegradability of cellulose) × 100 Seawater (collected from Tokyo Bay [Chiba Prefecture: Chiba Port]) The collected seawater was filtered to remove impurities using a 10 μm filter, and then aerated at room temperature (25°C). In addition, ammonium chloride (0.05 g / L) and potassium dihydrogen phosphate (0.1 g / L) were added as inorganic nutrients.

[0128] [Table 8]

[0129] Based on the results shown in Table 8, it is considered that the marine biodegradation accelerator of the present invention improves overall biodegradability and also promotes the biodegradation of biodegradable resins in seawater.

[0130] Based on the above results, the marine biodegradation accelerator of the present invention maintains hydrophobicity in freshwater, while in seawater, it becomes more easily dissolved or hydrophilic by being broken down into smaller molecules or subjected to salt substitution through biodegradation prior to the biodegradable resin. Therefore, by adding the marine biodegradation accelerator of the present invention to resin compositions that are biodegradable in soil / compost or mixed compositions that have weak biodegradability in the ocean, it becomes possible to create porous structures in seawater, facilitate the attachment of microorganisms, and promote biodegradation. As a result, it is possible to improve the overall marine biodegradability and reduce the environmental burden.

Claims

1. A marine biodegradation accelerator, which is a hydrophobic and thermoplastic powder, comprising a compound in which a monovalent organic anion derived from one selected from an amino acid derivative having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfonic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfuric acid ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms, and a monovalent phosphate ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms is ionically bonded to a divalent or higher metal cation, which is a calcium ion, a magnesium ion, or an aluminum ion, The aforementioned powder is a marine biodegradation accelerator that dissolves in a 3% by mass sodium chloride aqueous solution or exhibits hydrophilicity in a 3% by mass sodium chloride aqueous solution.

2. The marine biodegradation accelerator according to claim 1, wherein the amino acid derivative is a sarcosinic acid derivative having a monovalent hydrocarbon group having 10 to 25 carbon atoms or a glutamic acid derivative having a monovalent hydrocarbon group having 10 to 25 carbon atoms.

3. The marine biodegradation accelerator according to claim 2, wherein the amino acid derivative is lauroyl sarcosine, myristoyl sarcosine, palmitoyl sarcosine, myristoyl glutamic acid, or stearoyl glutamic acid.

4. The marine biodegradation accelerator according to any one of claims 1 to 3, wherein the monovalent organic anion does not contain a ring structure.

5. A marine biodegradation accelerator according to any one of claims 1 to 4, wherein the powder has an average particle size of 0.1 to 10,000 μm.

6. A marine biodegradation accelerator according to any one of claims 1 to 5, wherein the material is a thermoplastic powder with a melting temperature of 60 to 230°C.

7. The marine biodegradation accelerator according to any one of claims 1 to 6, wherein a water droplet is dropped onto a molten body of a group of particles consisting of the aforementioned powder, and the contact angle after 30 seconds is 50° or more.

8. A marine biodegradable resin composition comprising a marine biodegradation accelerator and a resin, The marine biodegradation accelerator is a hydrophobic and thermoplastic powder comprising a compound in which a monovalent organic anion derived from one selected from a monovalent carboxylic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfonic acid having a monovalent hydrocarbon group having 10 to 25 carbon atoms, a monovalent sulfate ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms, and a monovalent phosphate ester having a monovalent hydrocarbon group having 10 to 25 carbon atoms is ionically bonded to a divalent or higher metal cation, which is a calcium ion, a magnesium ion, or an aluminum ion, wherein the powder dissolves in a 3% by mass aqueous solution of sodium chloride, or exhibits hydrophilicity in a 3% by mass aqueous solution of sodium chloride. A marine biodegradable resin composition comprising a marine biodegradation accelerator with a content of 7 to 50% by mass and a resin with a content of 50 to 93% by mass.

9. The marine biodegradable resin composition according to claim 8, wherein the resin is a biodegradable resin.

10. A molded article obtained from the marine biodegradable resin composition according to claim 8 or 9.

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