Marine biodegradable polymer compounds and marine biodegradable compositions

Abstract

This invention provides a polymer compound with excellent thermal and mechanical properties that undergoes biodegradation in the ocean, and a marine biodegradable composition using the same. [Solution] A marine biodegradable polymer compound comprising a polyester-type polyvalent anion having a total of two or more monovalent anionic substituents at its termini, comprising two or more polyvalent carboxylic acid residues and one or more polyvalent alcohol residues, and a monovalent cation.

Description

Technical Field

[0001] The present invention relates to a marine biodegradable polymer compound and a marine biodegradable composition.

Background Art

[0002] In recent years, environmental pollution (marine pollution) caused by microplastics and its adverse effects on ecosystems have become problems, and various efforts to reduce environmental burdens have begun. Among them, the development and spread of biodegradable resins have attracted attention.

[0003] On the other hand, although general biodegradable resins exhibit high biodegradability in an environment where there are many microorganisms responsible for decomposition, such as soil and sludge, they have the drawback of being difficult to decompose in an environment where the microorganism concentration is extremely low, such as in the ocean (Non-Patent Document 1). Also, regarding resins such as polycaprolactone (PCL) and polyhydroxyalkanoic acid (PHA) for which biodegradability in the ocean has been reported, it has been found that their decomposition rates vary greatly depending on the type of seawater, and it has been reported that various factors such as the presence or absence and number of decomposing bacteria in seawater, salt concentration, pH, water temperature, dissolved oxygen concentration, and amount of dissolved organic carbon have an impact (Non-Patent Document 2).

[0004] In addition, although starch-based resins have been put into practical use and are on the market as biodegradable resins, single starch materials are greatly inferior in terms of physical properties, so most of them are mixed compositions with polyester-based resins that are difficult to biodegrade in the ocean, such as polybutylene adipate / terephthalate (PBAT) and polylactic acid (PLA). Therefore, even starch-based resins tend to have greatly reduced biodegradability in the ocean.

[0005] Under such circumstances, there is a demand for the development of materials that can surely decompose in any type of seawater while maintaining physical properties, materials that can act as decomposition accelerators for resins that are difficult to biodegrade in seawater, and materials that can reduce environmental burdens.

Prior Art Documents

Non-Patent Documents

[0006] [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]

[0007] This invention has been made in view of the above circumstances, and aims to provide a polymer compound that exhibits excellent thermal and mechanical properties and induces biodegradation in the ocean, and a marine biodegradable composition using the same. [Means for solving the problem]

[0008] The inventors, through diligent research to solve the aforementioned problems, have found that marine biodegradable polymer compounds comprising a polyester-type polyvalent anion containing two or more polyvalent carboxylic acid residues and one or more polyvalent alcohol residues, and having a total of two or more monovalent anionic substituents at its terminus, and a monovalent cation, as well as marine biodegradable polymer compounds in which the polyester-type polyvalent anion is bonded via a divalent or higher cation, exhibit high marine biodegradability while maintaining stable thermal and mechanical properties. Furthermore, they have found that marine biodegradable compositions to which these polymer compounds are added also have the effect of stabilizing thermal and mechanical properties and promoting biodegradation.

[0009] 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.

[0010] In other words, the present invention provides the following marine biodegradable polymer compounds and marine biodegradable compositions. 1. A marine biodegradable polymer compound comprising a polyester-type polyvalent anion containing two or more polyvalent carboxylic acid residues and one or more polyvalent alcohol residues, and having a total of two or more monovalent anionic substituents at its terminus, and a monovalent cation. 2. A marine biodegradable polymer compound wherein the monovalent cation is a proton, a monovalent metal cation, or a monovalent organic cation. 3. A marine biodegradable polymer compound of type 1 or 2, wherein all of the two or more polyvalent carboxylic acid residues are aliphatic carboxylic acid residues, and when r1 mol% is the proportion of aliphatic carboxylic acid residues having more than 4 carbon atoms to the total number of aliphatic carboxylic acid residues, and m1 is the number-average molecular weight, the value of P1, represented by the following formula (1), is between 0.250 and 0.802.

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[0011] The marine biodegradable polymer compound of the present invention is derived from two or more polycarboxylic acid residues and one or more polyol residues, achieving both thermal and mechanical properties and good biodegradability. Furthermore, the marine biodegradable polymer compound gradually dissolves in seawater or exhibits hydrophilicity upon contact with seawater, so compositions and molded articles containing it promote biodegradation in the ocean and are useful for combating marine pollution. Because the marine biodegradable polymer compound is marine biodegradable, compositions and molded articles containing it promote biodegradation in the ocean and are useful for combating marine pollution. By using a marine biodegradation accelerator containing the marine biodegradable polymer compound of the present invention, environmentally friendly compositions and molded articles can be obtained. [Modes for carrying out the invention]

[0012] [Marine biodegradable polymer compounds] A first aspect of the marine biodegradable polymer compound of the present invention comprises a polyester-type polyvalent anion having a total of two or more monovalent anionic substituents at its termini, comprising two or more polyvalent carboxylic acid residues and one or more polyvalent alcohol residues, and a monovalent cation.

[0013] The monovalent anionic substituent is a carboxylic acid anion (-COO - ), sulfonate anion (-SO3 - ), sulfate anion (-O-SO3 - ), phosphate anion (-P(=O)(OH)-O - Examples include the following. Of these, carboxylate anions, sulfonate anions, and sulfate anions are preferred, and carboxylate anions are particularly preferred from an environmental perspective.

[0014] The monovalent cation is preferably a proton, a monovalent metal cation, or a monovalent organic cation. Hereinafter, a compound in which the monovalent cation is only a proton will be referred to as marine biodegradable polymer compound A, and a compound in which the monovalent cation includes cations other than protons will be referred to as marine biodegradable polymer compound B.

[0015] It is preferable that at least one of the two or more polyvalent carboxylic acid residues constituting marine biodegradable polymer compounds A and B is an aliphatic carboxylic acid residue. If all of the two or more polyvalent carboxylic acid residues are aliphatic carboxylic acid residues, then, if r1 mol% is the percentage of aliphatic carboxylic acid residues with more than 4 carbon atoms in the total number of aliphatic carboxylic acid residues, then from the viewpoint of thermal and mechanical properties and biodegradability, the lower limit of the value of r1 is preferably 10 mol%, 15 mol%, and 20 mol%, in that order, and the upper limit is preferably 90 mol%, 85 mol%, and 80 mol%, in that order. Furthermore, if at least one of the two or more carboxylic acid residues is an aliphatic carboxylic acid residue and at least one is an aromatic carboxylic acid residue, and the sum of the proportions of each aliphatic carboxylic acid residue to the total number of aliphatic carboxylic acid residues and total aromatic carboxylic acid residues is r2 mol% (however, the proportion of aliphatic carboxylic acid residues with 4 or fewer carbon atoms is multiplied by 0.250 when added to r2), then from the viewpoint of thermal and mechanical properties and biodegradability, the lower limit of the value of r2 is preferably 30 mol%, 35 mol%, and 40 mol%, in that order, and the upper limit is preferably 95 mol%, 90 mol%, 85 mol%, 80 mol%, 70 mol%, and 60 mol%, in that order. Furthermore, if at least one of the two or more carboxylic acid residues is an aliphatic carboxylic acid residue and at least one is an aromatic carboxylic acid residue, and the aliphatic carboxylic acid residue includes an aliphatic carboxylic acid residue having 4 or fewer carbon atoms, the lower limit of the percentage of aliphatic carboxylic acid residues having 4 or fewer carbon atoms relative to the total carboxylic acid residues is preferably 0.01 mol%, 0.05 mol%, and 0.1 mol%, in that order, and the upper limit is preferably 70 mol%, 50 mol%, and 30 mol%, in that order. r1 and r2 can be calculated by determining the composition of the constituent carboxylic acid residues using, for example, general methods such as nuclear magnetic resonance spectroscopy, infrared spectroscopy, and ultraviolet-visible spectroscopy.

[0016] From the viewpoint of balancing thermal and mechanical properties and biodegradability, the number average molecular weight of marine biodegradable polymer compound A is preferably in the order of lower limit 500, 1000, 1500, and 2000, and in the order of upper limit 50000, 20000, 10000, and 5000. From the viewpoint of thermal and mechanical properties, biodegradability, and reactivity, the number average molecular weight of marine biodegradable polymer compound B is preferably in the order of lower limit 500, 1000, 1500, and 2000, and in the order of upper limit 50000, 20000, 10000, and 5000.

[0017] As a method for comprehensively evaluating the thermal, mechanical properties and biodegradability from the composition ratio of the two or more polyvalent carboxylic acid residues and the number-average molecular weight of marine biodegradable polymer compound A, the following formulas (1) and (2) can be used. In the following formulas, m1 is the number-average molecular weight of marine biodegradable polymer compound A in which all of the two or more polyvalent carboxylic acid residues are aliphatic carboxylic acid residues, and m2 is the number-average molecular weight of marine biodegradable polymer compound A in which at least one of the above is an aliphatic carboxylic acid residue and at least one is an aromatic carboxylic acid residue.

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[0018] If all of the polyvalent carboxylic acid residues are aliphatic carboxylic acid residues, the lower limit of the P1 value determined by formula (1) is preferably 0.250, 0.300, 0.375, and 0.400 in that order, and the upper limit is preferably 0.802, 0.781, 0.720, and 0.700 in that order. Furthermore, if at least one of the polyvalent carboxylic acid residues is an aliphatic carboxylic acid residue and at least one is an aromatic carboxylic acid residue, the lower limit of the P2 value determined by formula (2) is preferably 0.245, 0.290, 0.310, and 0.340 in that order, and the upper limit is preferably 0.805, 0.785, 0.770, and 0.760 in that order.

[0019] Marine biodegradable polymer compounds A and B may have linear, branched, cyclic, or a combination thereof, but from the viewpoint of biodegradability and physical properties, they are preferably linear or branched, and more preferably linear. Linear marine biodegradable polymer compound A can be obtained, for example, by selecting a bifunctional compound from the examples of polycarboxylic acids or polyhydric alcohols described later and reacting them. Branched marine biodegradable polymer compound A can be obtained, for example, by selecting a compound in which at least one part is trifunctional or more from the examples of polycarboxylic acids or polyhydric alcohols described later and reacting them.

[0020] From the viewpoint of thermal, mechanical, and biodegradable properties, the polyhydric alcohol residues constituting marine biodegradable polymer compounds A and B are preferably in the order of 2, 3, 4, 5, and 6 for the lower limit of their carbon number, and 20, 18, 16, and 14 for the upper limit.

[0021] Examples of polyhydric alcohols that become the aforementioned polyhydric alcohol residues include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-butene-1,4-diol, 1,2,3-butanetriol, 1,2,4-butanetriol, 1,5-pentanediol, 2,4-pentanediol, 2-hydroxy-2-ethyl-1,3-propanol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,3,5-cyclohexanetriol, 1,6-hexanediol, 2,5-hexanediol, 3-methyl-1,5-pentanediol, 1,7-heptanediol, and 1,4-ben Examples include zendimethyl, 3,6-diazaoctane-1,8-diol, 2,6-dihydroxynaphthalene, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, phloroglucinol, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, polyethylene glycol, glycerol, trimethylolpropane, pentaerythritol, 1,2,5-pentanetriol, pyrogallol, and 1,2,4-benzenetriol. Marine biodegradable polymer compound A preferably has a polyhydric alcohol residue derived from at least one selected from ethylene glycol, 1,3-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, glycerol, and pentaerythritol; more preferably has a polyhydric alcohol residue derived from at least one selected from ethylene glycol, 1,4-butanediol, 3-methyl-1,5-pentanediol, and glycerol; and even more preferably has a polyhydric alcohol residue derived from at least one selected from 1,4-butanediol and 3-methyl-1,5-pentanediol.

[0022] From the viewpoint of thermal, mechanical, and biodegradable properties, the polycarboxylic acid residues constituting marine biodegradable polymer compounds A and B are preferably in the order of 2, 3, 4, 5, and 6 for the lower limit of their carbon number, and 20, 18, 16, and 14 for the upper limit.

[0023] Examples of aliphatic polycarboxylic acids among the polycarboxylic acids that become the aforementioned polycarboxylic acid residues include linear dicarboxylic acids with 2 to 20 carbon atoms such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid, as well as aliphatic polycarboxylic acids with 2 to 20 carbon atoms such as fumaric acid, maleic acid, malic acid, 1,2,3-propanetricarboxylic acid, aconitic acid, and citric acid. Examples of aromatic polycarboxylic acids include naphthalenedicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, franciocarboxylic acid, 5-sulfoisophthalic acid, 2,3-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid, as well as aromatic polycarboxylic acids with 8 to 20 carbon atoms such as 1,3,5-benzenetricarboxylic acid, biphenyldicarboxylic acid, trimetic acid, and pyromellitic acid. Marine biodegradable polymer compound A preferably has a carboxylic acid residue derived from at least one selected from succinic acid, adipic acid, sebacic acid, terephthalic acid, franzicarboxylic acid, 5-sulfoisophthalic acid, and 2,6-naphthalenedicarboxylic acid, and more preferably has a carboxylic acid residue derived from at least one selected from succinic acid, adipic acid, terephthalic acid, and franzicarboxylic acid.

[0024] When all of the two or more polycarboxylic acid residues are aliphatic carboxylic acid residues, the combination is preferably derived from at least one aliphatic polycarboxylic acid having 4 or fewer carbon atoms and at least one aliphatic polycarboxylic acid having 5 or more carbon atoms. Specifically, the at least one aliphatic polycarboxylic acid having 4 or fewer carbon atoms is preferably selected from oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, and 1,2,3-propanetricarboxylic acid, more preferably from succinic acid, maleic acid, and fumaric acid, and even more preferably from succinic acid. The at least one aliphatic polycarboxylic acid having 5 or more carbon atoms is preferably selected from adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid, more preferably from adipic acid, azelaic acid, and sebacic acid, and even more preferably from adipic acid and sebacic acid.

[0025] When at least one of the two or more polycarboxylic acid residues is an aliphatic carboxylic acid residue and at least one is an aromatic carboxylic acid residue, the combination is preferably derived from at least one selected from aliphatic polycarboxylic acids having 4 to 12 carbon atoms and at least one selected from aromatic polycarboxylic acids having 6 to 16 carbon atoms. Specifically, the at least one selected from aliphatic polycarboxylic acids having 4 to 12 carbon atoms is preferably selected from succinic acid, maleic acid, fumaric acid, 1,2,3-propanetricarboxylic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid, more preferably from succinic acid, maleic acid, adipic acid, azelaic acid, and sebacic acid, and even more preferably from succinic acid, adipic acid, and sebacic acid. At least one of the aromatic polycarboxylic acids having 6 to 16 carbon atoms is preferably selected from phthalic acid, isophthalic acid, terephthalic acid, franzicarboxylic acid, 5-sulfoisophthalic acid, 2,3-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,3,5-benzenetricarboxylic acid, trimetic acid, and pyromellitic acid; more preferably selected from isophthalic acid, terephthalic acid, 5-sulfoisophthalic acid, 1,6-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid; and even more preferably selected from isophthalic acid, terephthalic acid, and 5-sulfoisophthalic acid.

[0026] Marine biodegradable polymer compounds A and B preferably have a relative biodegradation rate of 40% or more relative to cellulose. In this invention, relative biodegradation rate of cellulose refers to the maximum degree of degradation relative to the maximum degree of cellulose degradation within two years after immersion in seawater. Marine biodegradable polymer compounds A and B are more preferably 50% or more relative to cellulose, even more preferably 60% or more, and most preferably 80% or more. Relative biodegradation rate of cellulose can be measured by ASTM D6691, known marine biodegradation test methods, etc., or BOD modified based on these, and if the sample to be measured is solid, it should be powdered before measurement.

[0027] Marine biodegradable polymer compound B is a compound in which some or all of the protons of the acidic group of marine biodegradable polymer compound A are replaced by monovalent cations other than protons. In other words, marine biodegradable polymer compound B is a salt compound consisting of a polyester-type polyvalent anion, which is a structure in which the protons of the acidic group of marine biodegradable polymer compound A are freed, and a countercation of the anionic group.

[0028] Preferred monovalent metal cations in marine biodegradable polymer compound B include lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, and francium ions. Preferred monovalent organic cations in marine biodegradable polymer compound B include ammonium ions, methylammonium ions, ethylammonium ions, anilinium ions, pyridinium ions, dimethylammonium ions, diethylammonium ions, trimethylammonium ions, and triethylammonium ions. Of these, sodium ions, potassium ions, and ammonium ions are preferred as monovalent cations in marine biodegradable polymer compound B from the viewpoint of safety, environmental impact, and ease of handling, with sodium ions and potassium ions being more preferred.

[0029] The properties of marine biodegradable polymer compound B can be adjusted by the content of monovalent cations other than protons contained therein. When used as a precursor for a crosslinked product with divalent cations as described later, the content of monovalent cations other than protons is preferably 80 mol% or more, 90 mol% or more, and 95 mol% or more of the total monovalent cations, in that order. When marine biodegradable polymer compound B is used as a raw material for a marine biodegradation accelerator, the content of monovalent cations other than protons is preferably 30 mol% or less, 20 mol% or less, and 10 mol% or less of the total monovalent cations, in that order.

[0030] Examples of methods for synthesizing marine biodegradable polymer compound A include introducing acidic groups to the terminals during polyester synthesis, and synthesizing polyesters with hydroxyl groups at the terminals and then introducing acidic groups through a modification reaction.

[0031] One example of a method for introducing acidic groups to the terminals during polyester synthesis is the direct polycondensation method of polycarboxylic acid and polyhydric alcohol. By mixing a polycarboxylic acid and a polyhydric alcohol and heating, a polycondensation reaction proceeds to obtain a polyester. It is preferable to use an excess of polycarboxylic acid compared to the polyhydric alcohol in order to introduce acidic groups to the terminals, and the amount of polycarboxylic acid is preferably 1.20, 1.10, and 1.05 times the amount of polyhydric alcohol, in that order. The lower limit of the heating temperature is preferably 150°C, 160°C, and 170°C, in that order, and the upper limit is preferably 230°C, 220°C, and 210°C, in that order. The polycarboxylic acid may be a derivative such as an acid halogenated compound or an ester, as long as it can be subsequently converted to a carboxyl group, and the polyhydric alcohol may also be a derivative. The polymerization time is preferably about 0.5 to 24 hours, more preferably about 1 to 12 hours, and even more preferably about 1.5 to 8 hours.

[0032] In polycondensation reactions, phosphite esters such as triphenyl phosphite or carbodiimide-based condensing agents such as DCC may be used to facilitate the reaction.

[0033] Another method for introducing acidic groups to the terminals during synthesis is by depolymerization. One example of this method involves adding water and a polycarboxylic acid to a high molecular weight polyester compound and heating it. A marine biodegradable polymer compound A can be obtained by hydrolysis and terminal modification. The amount of water used is preferably such that N / n is 2 to 20, and more preferably 4 to 10, where n is the value obtained by dividing the amount of water by the amount of high molecular weight polyester and adding 1, and N is the number-average degree of polymerization of the high molecular weight polyester. The amount of polycarboxylic acid used is preferably 1.01 to 1.5 times the amount of water, more preferably 1.05 to 1.4 times, and even more preferably 1.1 to 1.3 times. It is preferable to use a polycarboxylic acid derived from the polycarboxylic acid residues that constitute the high molecular weight polyester. In depolymerization, general acids and bases may be used to facilitate the reaction.

[0034] Examples of methods for synthesizing polyesters with hydroxyl groups at their terminal ends and then introducing acidic groups through modification reactions include reactions with acid anhydrides and reactions with SO3-Lewis salt complexes.

[0035] Methods for synthesizing polyesters having hydroxyl groups at their termini include direct polycondensation of polycarboxylic acids and polyhydric alcohols, polycondensation using polycarboxylic acid derivatives and polyhydric alcohol derivatives, and depolymerization.

[0036] In the direct polycondensation of polyesters having hydroxyl groups at the terminals, it is preferable to use a polyhydric alcohol in excess of the polycarboxylic acid to introduce hydroxyl groups at the terminals, and the amount of polyhydric alcohol is preferably 1.20, 1.10, and 1.05 times the amount of polycarboxylic acid, in that order. The lower limit of the heating temperature is preferably 150°C, 160°C, and 170°C, in that order, and the upper limit is preferably 230°C, 220°C, and 210°C, in that order. The polymerization time is preferably about 0.5 to 24 hours, more preferably about 1 to 12 hours, and even more preferably about 1.5 to 8 hours.

[0037] If the resulting compound is a polyester having a hydroxyl group at its terminus, derivatives of polycarboxylic acids and polyhydric alcohols may be used instead. When derivatives are used, methods using acid chlorides of polycarboxylic acids or transesterification using esters of polycarboxylic acids (e.g., ethyl esters, ethyl esters, or isopropyl esters of polycarboxylic acids) are preferred from the viewpoint of reactivity and environmental impact, and transesterification using methyl esters is particularly preferred.

[0038] In transesterification reactions of polycarboxylic acid esters with polyhydric alcohols, metal catalysts such as titanium, antimonstin, and zirconium may be used to ensure efficient reaction, and titanium catalysts having alkoxy groups are particularly preferred. Examples of such catalysts include titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide, titanium tetraisobutoxide, antimony trioxide, antimony triacetate, triphenylantimony, tributylantimony, tin formate, tin oxalate, potassium titanium oxalate, tetraphenyltin, dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide, dibutyltin dilaurate, zirconium tetraethoxide, zirconium tetrapropoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide, zirconium tetraisobutoxide, zirconium tetraacetylacetonate, zirconium octoate, zirconium stearate, etc. It is particularly preferable to use titanium catalysts having alkoxy groups, such as titanium tetraisopropoxide, titanium tetrapropoxide, and titanium tetrabutoxide. The amount of catalyst used is preferably 0.001 to 2.0% by mass of the high molecular weight polyester, and more preferably 0.005 to 1.0% by mass, from the viewpoint of reactivity and environmental impact.

[0039] Depolymerization is another method for obtaining polyesters having hydroxyl groups at their ends. One example of this method involves adding a polyhydric alcohol to a high molecular weight polyester compound and heating it to perform alcohol decomposition. This allows for obtaining polyesters having hydroxyl groups at their ends. The amount of polyhydric alcohol used is preferably such that N / n is 2 to 20, and more preferably 4 to 10, when n is the value obtained by multiplying the amount of polyhydric alcohol by 0.85, dividing that value by the amount of high molecular weight polyester, and adding 1 to that value, and N is the number-average degree of polymerization of the high molecular weight polyester. In depolymerization, a metal catalyst used in transesterification may also be used, and the amount used is preferably 0.01 to 3.0% by mass of the high molecular weight polyester, and more preferably 0.1 to 1.0% by mass. It is preferable to use a polyhydric alcohol derived from the polyhydric alcohol residues that constitute the high molecular weight polyester.

[0040] In depolymerization, two or more of the high molecular weight polyester compounds may be used. Furthermore, a polycarboxylic acid or its derivative may be added simultaneously to adjust the constituent components of the resulting oligomer. The amount of carboxylic acid or its derivative added to adjust the constituent components is preferably 40%, 30%, and 20% by mass of the high molecular weight polyester as the upper limit, and 1%, 5%, and 10% by mass as the lower limit. In this case, assuming that the polycarboxylic acid or its derivative forms an ester with the coexisting polyhydric alcohol, the aforementioned n is defined as the value obtained by dividing 0.85n1-n2(v2-1) by the amount of substance of the high molecular weight polyester and adding 1, where n1 is the amount of substance of the polyhydric alcohol, v1 is the valence of the alcohol, and n2 is the amount of substance of the polycarboxylic acid and v2 is its valence. However, if 0.85n1-n2(v-1) is negative, n is defined as the value obtained by dividing n2-0.85n1(v1-1) by the amount of substance of the high molecular weight polyester and adding 1.

[0041] As a method for introducing an acidic group to the terminal of a polyester having a hydroxyl group at its terminus, for example, when introducing a carboxyl group, one method is to react the polyester having a hydroxyl group at its terminus with a divalent carboxylic acid anhydride. Examples of the divalent carboxylic acid anhydride include succinic anhydride, glutaric anhydride, maleic anhydride, phthalic anhydride, O-acetyl-L-malic acid anhydride, cyclohexanedicarboxylic acid anhydride, tetrahydrophthalic acid anhydride, 1-cyclohexene-1,2-dicarboxylic acid anhydride, diglycolic acid anhydride, and 1,2-naphthalic acid anhydride. Of these, succinic anhydride, glutaric anhydride, maleic anhydride, and phthalic anhydride are preferred, and succinic anhydride, glutaric acid anhydride, and maleic anhydride are more preferred when considering biodegradability. The reaction between the polyester having a hydroxyl group at its terminus and the acid anhydride can be carried out using known methods commonly used for the reaction of acid anhydrides with alcohols, such as heating and mixing the two.

[0042] As a method for introducing an acidic group to the end of a polyester having a hydroxyl group at its terminus, for example, when introducing a sulfuric acid ester group, one method is to react the polyester having hydroxyl groups at both ends with sulfur trioxide or a complex of sulfur trioxide and a Lewis base. Preferred Lewis bases constituting the complex of sulfur trioxide and a Lewis base include tertiary amines, pyridine, dimethylformamide, and dioxane. This can be carried out by referring to known methods, such as using a solvent as needed.

[0043] Marine biodegradable polymer compound B can be synthesized, for example, by neutralizing some or all of the acidic groups of marine biodegradable polymer compound A using a base in a known acid-base reaction commonly used for neutralization. Examples of bases used in the neutralization reaction include lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, trisodium phosphate, tripotassium phosphate, lithium methoxide, sodium methoxide, potassium methoxide, lithium tert-butoxide, sodium tert-butoxide, potassium tert-butoxide, ammonia, methylamine, ethylamine, triethylamine, diazabicycloundecene, etc. Lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium bicarbonate, sodium bicarbonate, potassium bicarbonate, and ammonia are preferred, and considering safety and environmental impact, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate are particularly preferred.

[0044] A second aspect of the marine biodegradable polymer compound of the present invention is a structure in which polyester-type polyvalent anions constituting marine biodegradable polymer compound A or B are linked via divalent or higher cations (hereinafter also referred to as marine biodegradable polymer compound C). That is, marine biodegradable polymer compound C has a structure in which polyester-type polyvalent anions derived from marine biodegradable polymer compound A or B are crosslinked by polyvalent cations.

[0045] The aforementioned cations with a valency of 2 or higher are not particularly limited, but include ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-butanediamine, 1,5-diaminopentane, 1,6-diaminohexane (hexamethylenediamine), 1,7-diaminoheptane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane, 3,3-diaminodipropylamine, tris(3-aminopropyl)amine, 3,3'-diaminobenzidine, 1,4-cyclohexadiamine, spermine, spermidine, triethylenetetramine, 1,4-f Examples include polyvalent ammonium cations obtained from divalent or higher amines such as phenylenediamine, 1,2-diphenylethylenediamine, and orthotolidine, as well as calcium ions, beryllium ions, magnesium ions, strontium ions, barium ions, zinc ions, aluminum ions, iron ions, copper ions, platinum ions, gold ions, titanium ions, nickel ions, cobalt ions, manganese ions, zirconium ions, ruthenium ions, rhodium ions, palladium ions, scandium ions, gallium ions, indium ions, and radium ions. Of these, ethylenediammonium, calcium ions, beryllium ions, magnesium ions, strontium ions, barium ions, zinc ions, and aluminum ions are preferred, and calcium ions, magnesium ions, and aluminum ions are more preferred. The divalent or higher cations may be used individually or in combination of two or more.

[0046] The polyvalent ion equivalents in the aforementioned marine biodegradable polymer compound C are set to an upper limit of 100, 80, and 50 eq / 10 from the viewpoint of thermal, mechanical properties and biodegradability. 5 The order of preference is g, with 1, 2, 5 and 10 eq / 10 as the lower limit. 5 The order of preference is g. If the ion equivalent is within the above range, it is preferable because it has good biodegradability and its mechanical properties are not impaired. The ion equivalent is measured by inductively coupled plasma mass spectrometry (ICP-MS) when the ion is a metal, and by liquid chromatography-mass spectrometry (LC-MS) when the ion is an organic cation.

[0047] The aforementioned polyvalent ion equivalent is a theoretical value obtained when all polyester-type polyvalent anions and all polyvalent cations are stoichiometrically consumed, due to the infinite linkage of polyfunctional polyester-type polyvalent anions via polyvalent cations, and the linking polymer compound itself linking with polyvalent cations within the molecule. ideal Therefore, k ideal =nf / nv·1 / Mn·10 5 eq / 10 5 It is expressed as g. Here, nf is the number of anionic functional groups of the polyester-type polyvalent anion, nv is the valence of the polyvalent cation, and Mn is the number-average molecular weight of the polyester-type polyvalent anion. The polyfunctional polyester-type polyvalent anion constituting the marine biodegradable polymer compound C, in combination with a polyvalent cation, is k ideal The upper limit for the value is 100, 80, and 50eq / 10 5 The order of preference is g, with 1, 2, 5 and 10 eq / 10 as the lower limit. 5 The order of preference is g. ideal If the value is within the aforementioned range, it is preferable because it has good biodegradability and its mechanical properties are not impaired.

[0048] Let k be the polyvalent ion equivalent in the marine biodegradable polymer compound C, and k and the k ideal The ratio is given by q = k / k ideal In this case, the value of q is preferably in the range of 0.70 to 1.30, more preferably in the range of 0.80 to 1.20, and even more preferably in the range of 0.90 to 1.10. If the value of q is within this range, the polyvalent anion and polyvalent cation are sufficiently bonded, and there are few excess ions, indicating a good state.

[0049] Marine biodegradable polymer compound C is a compound in which a polyester-type polyvalent anion contained in the aforementioned marine biodegradable polymer compound A or B is bonded via a metal cation. In marine biodegradable polymer compound C, only one type of polyester-type polyvalent anion may be present, or multiple different types may be present. Marine biodegradable polymer compound C may also simultaneously contain anions derived from anionic compounds other than marine biodegradable polymer compound B (hereinafter also referred to as other anionic compounds). Examples of other anionic compounds include polymer compounds with anionic groups at their terminals and a number average molecular weight of 500 to 10000, carboxylic acid anions with a molecular weight of 1000 or less, amino acid anions with a molecular weight of 1000 or less, amino acid derivative anions with a molecular weight of 1000 or less, and sulfonic acid anions with a molecular weight of 1000 or less.

[0050] An example of a polymer compound having an anionic group at its terminus and a number-average molecular weight of 500 to 10000 is a compound obtained by introducing an acidic group to a polymer compound having an active hydrogen group such as a hydroxyl group, amino group, or thiol group at its terminus, and then neutralizing it. A method for introducing the acidic group is to introduce an acidic group to the aforementioned polyester having a hydroxyl group at its terminus by a modification reaction. As for the polymer compound having an anionic group at its terminus and a number-average molecular weight of 500 to 10000, a compound obtained by reacting a polymer compound having an active hydrogen group such as a hydroxyl group or amino group at its terminus with succinic anhydride, maleic anhydride, or phthalic anhydride and then neutralizing it is preferred, and a compound obtained by reacting a polymer compound having a hydroxyl group at its terminus with succinic anhydride or maleic anhydride and then neutralizing it is more preferred.

[0051] The polymer compound having a hydroxyl group at the terminal or the polymer compound having an amino group at the terminal may be a commercially available product or a synthesized product. Examples of the commercially available products include Kuraray Polyol P-1010, P-2010, P-2011, P-2012, P-2020, P-2050, P-520, C-590, C-1090, F-510, F-1010 (manufactured by Kuraray Co., Ltd.), Praxel 210B, 220N, 308 (manufactured by Daicel Corporation), polypropylene glycol, diol type 1000, polypropylene glycol, triol type 300 (manufactured by Fujifilm Wako Pure Chemical Industries Ltd.), poly(propylene glycol) bis(2-aminopropyl ether) 400, poly(propylene glycol) bis(2-aminopropyl ether) 2000 (manufactured by Sigma-Aldrich Japan LLC), and the like. One example of synthesis is a method in which two or more appropriate raw materials are selected from the aforementioned divalent or higher carboxylic acids, divalent or higher alcohols and divalent or higher amines, as well as the divalent or higher isocyanates, lactones, lactams, etc., described later, and polycondensation or polyaddition reactions are carried out. For example, polyester polyols can be obtained by polycondensation of a divalent or higher carboxylic acid and a divalent or higher alcohol, polyamide polyamines by polycondensation of a divalent or higher carboxylic acid and a divalent or higher amine, polyurethane polyols by polyaddition of a divalent or higher isocyanate and a divalent or higher alcohol, ring-opening polymerization type polyester polyols by ring-opening polymerization of a divalent or higher alcohol and a lactone, and ring-opening polymerization type polyamide polyamines by ring-opening polymerization of a divalent or higher amine and a lactam. However, the combinations are not limited to these, and three or more raw materials with different functional groups, or two or more different raw materials having the same functional group, may be used simultaneously. The aforementioned divalent or higher carboxylic acids, divalent or higher alcohols, divalent or higher amines, divalent or higher isocyanates, lactones / lactides, and lactams may be derivatized, for example, by acid halides, esters, or halides, in order to enhance reactivity. Known methods can be used for the polycondensation and polyaddition reactions, and metal catalysts or organic catalysts may be used to enhance reactivity as needed.

[0052] The aforementioned amines with a valency of 2 or higher include ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-butanediamine, 1,5-diaminopentane, 1,6-diaminohexane (hexamethylenediamine), 1,7-diaminoheptane, 1,8-diaminooctane, 1,10-diaminodecane, 1,12-diaminododecane, 3,3-diaminodipropylamine, tris(3-aminopropyl)amine, 3,3'-diaminobenzidine, 1, Examples include 4-cyclohexadiamine, spermine, spermidine, triethylenetetramine, 1,4-phenylenediamine, 1,2-diphenylethylenediamine, and orthotolidine. Ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,4-butanediamine, hexamethylenediamine, and 1,4-phenylenediamine are particularly preferred, with ethylenediamine, 1,4-butanediamine, and hexamethylenediamine being more preferred.

[0053] Examples of the divalent or higher isocyanates include hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), isophorone diisocyanate (IPDI), cyclohexane-1,4-diisocyanate, methylenebis(4-cyclohexyl isocyanate), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymeric MDI, xylene diisocyanate, 1,4-phenylene diisocyanate, and others, with HDI, PDI, MDI, and TDI being particularly preferred.

[0054] Examples of the aforementioned lactones and lactides include β-propiolactone, γ-butyrolactone, ε-caprolactone, δ-hexanolactone, mevalonate lactone, 1,3-dioxan-2-one, 1,4-dioxan-2-one, 1,4-dioxan-2,5-dione, γ-heptanolactone, γ-hexanolactone, glycolide, lactide, and 1,6-dioxacyclodecane-2,7-dione, with ε-caprolactone, glycolide, and lactide being particularly preferred.

[0055] Examples of the lactams include β-propiolactam, ε-caprolactam, ω-heptalactam, ω-octalactam, and ω-laurinlactam, with β-propiolactam and ε-caprolactam being particularly preferred.

[0056] Examples of carboxylic acid anions with a molecular weight of 1000 or less that may be included in the aforementioned marine biodegradable polymer compound C include 1,5-naphthalenedisulfonic acid, ethanedisulfonic acid, monoethyl phosphate, malic acid, aspartic acid, glutamic acid, succinic acid, adipic acid, sebacic acid, terephthalic acid, isophthalic acid, caproic acid, enanthic acid, caprylic acid, octic acid, pelargonic acid, capric acid, undecylenic acid, lauric acid, myristic acid, pentadecyl acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid Examples of anions include phosphoric acid, isostearic acid, oleic acid, vaccenic acid, ricinoleic acid, linoleic acid, linolenic acid, eleostearic acid, oxystearic acid, arachidic acid, meadic acid, arachidonic acid, eicosapentaenoic acid, behenic acid, docosahexaenoic acid, lignoceric acid, nervonic acid, cerotic acid, montanic acid, melissic acid, coconut oil fatty acid, and palm oil fatty acid, with lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, and linoleic acid anions being particularly preferred.

[0057] The amino acid anions or amino acid derivative anions with a molecular weight of 1000 or less that may be contained in the aforementioned marine biodegradable polymer compound C include anions of amino acids such as alanine, leucine, arginine, lysine, asparagine, methionine, aspartic acid, phenylalanine, cysteine, proline, glutamine, serine, glutamic acid, threonine, glycine, tryptophan, histidine, tyrosine, and isoleucine, as well as sarcosine derivatives (caproyl sarcosine, lauroyl sarcosine, myristoyl sarcosine, palmitoyl sarcosine). Glucosine, coconut oil fatty acid sarcosine, etc., glutamic acid derivatives (caproyl glutamic acid, 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, dilauroyl glutamic acid, etc.), glycine derivatives (lauroyl glycine, myristoyl glycine, palmitoyl glycine, palmitoyl methylglycine, coconut oil fatty acid acylglycine, cocoyl glycine, etc.), alanine derivatives (lauryl methyl Alanine, myristoyl methylalanine, cocoyl alanine, coconut oil fatty acid methylalanine, etc.), lysine derivatives (lauroyl lysine, myristoyl lysine, palmitoyl lysine, stearoyl lysine, oleyl lysine, acylated lysine, etc.), aspartic acid derivatives (lauroyl aspartic acid, myristoyl aspartic acid, palmitoyl aspartic acid, stearoyl aspartic acid, etc.), taurine derivatives (lauroyl taurine, lauroyl methyl taurine, myristoyl taurine, myristoyl methyl taurine, palmitoyl Examples include anions of amino acid derivatives having hydrocarbon groups, such as taurine, palmitoylmethyltaurine, stearoyltaurine, stearoylmethyltaurine, etc., and proline derivatives (lauroylproline, myristoylproline, palmitoylproline, etc.). Particularly preferred are anions of caproyl sarcosine, lauroyl sarcosine, myristoyl sarcosine, palmitoyl sarcosine, caproyl glutamic acid, lauroyl glutamic acid, myristoyl glutamic acid, palmitoyl glutamic acid, and stearoyl glutamic acid.

[0058] Examples of sulfonic acid anions with a molecular weight of 1000 or less that may be included in the marine biodegradable polymer compound C include alkyl sulfonic acids (lauryl sulfonic acid, myristyl sulfonic acid, cetyl sulfonic acid, stearyl sulfonic acid, oleyl sulfonic acid, etc.), dodecylbenzene sulfonic acid, dialkyl succinate sulfonic acid, monoalkyl succinate sulfonic acid, naphthalene sulfonic acid, olefin sulfonic acid, alkyl isethionic acid (lauroyl isethionic acid, myristoyl isethionic acid, palmitoyl isethionic acid, stearoyl isethionic acid, etc.), and dialkyl sulfosuccinate (dihexyl sulfosuccinate, dioctyl sulfosuccinate, didecyl sulfosuccinate, diisobutyl sulfosuccinate, etc.), with lauryl sulfonic acid, myristyl sulfonic acid, cetyl sulfonic acid, and stearyl sulfonic acid anions being particularly preferred.

[0059] If the marine biodegradable polymer compound C contains anions derived from other anionic compounds, the amount thereof is not particularly limited as long as it does not impair the effects of the present invention.

[0060] When marine biodegradable polymer compound C is mixed with other resins, it is preferable that it has a softening point or melting point suitable for the melting temperature of those resins. The polymer compound is solid at room temperature, and more specifically, the lower limit of the softening point or melting point is preferably 40°C, 50°C, and 60°C in that order, and the upper limit is preferably 250°C, 180°C, 160°C, and 140°C in that order. If the other resin is a biodegradable resin, it is preferable that the softening point or melting point is within the range of 40 to 200°C, more preferably 50 to 160°C, and even more preferably 60 to 140°C.

[0061] The marine biodegradable polymer compound C preferably has a relative biodegradation rate of 40% or more relative to cellulose. In this invention, relative biodegradation rate of cellulose refers to the degree of decomposition of cellulose after 60 days of immersion in seawater. The marine biodegradable polymer compound C is more preferably 50% or more relative to cellulose, even more preferably 60% or more, and most preferably 80% or more. The relative biodegradation rate of cellulose can be measured by ASTM D6691, known marine biodegradation test methods, or BOD modified based on these, and if the sample to be measured is solid, it should be powdered before measurement.

[0062] Marine biodegradable polymer compound C can be produced by a method that includes a step of crosslinking the polyester-type polyvalent anion contained in marine biodegradable polymer compound A or B using a polyvalent salt.

[0063] The aforementioned crosslinking treatment methods include a method in which a powder or solution of polyvalent salt is added dropwise to a medium in which marine biodegradable polymer compound B is dissolved or dispersed, and precipitates or settles while performing a bonding treatment; a method in which a powder or solution of polyvalent salt is added dropwise to a molten solution of marine biodegradable polymer compound B, and a bonding treatment is performed; and a method in which a solution in which marine biodegradable polymer compound B is dissolved is added dropwise to a solution in which a powder of polyvalent salt or a polyvalent metal salt is dissolved, and precipitates or settles while performing a bonding treatment.

[0064] As a preferred example, a solution is prepared by dissolving or dispersing marine biodegradable polymer compound B in water, an organic solvent, or a mixture thereof, or by heating marine biodegradable polymer compound B to dissolve or disperse it. At this time, heating may be done as necessary to improve solubility and dispersibility, or to reduce the viscosity of the molten liquid. Next, a solution containing a divalent or higher salt is added to the obtained solution, dispersion, or molten liquid and stirred. Alternatively, a solution, dispersion, or molten liquid in which marine biodegradable polymer compound B is dissolved in a solution containing a divalent or higher salt may be added and stirred.

[0065] Examples of the polyvalent salts include organic salts such as the salts of the polyvalent amines, and metallic salts such as calcium salts, strontium salts, magnesium salts, barium salts, radium salts, lead salts, zinc salts, nickel salts, iron salts, copper salts, cadmium salts, cobalt salts, manganese salts, aluminum salts, gallium salts, indium salts, and thallium salts. However, from the standpoint of environmental impact, safety, and versatility, ethylenediammonium salts, calcium salts, magnesium salts, and aluminum salts are preferred, and calcium salts and magnesium salts are more preferred when considering the environment of seawater. Specific examples of the polyvalent salts include ethylenediamine hydrochloride, ethylenediamine sulfate, calcium chloride, calcium sulfate, calcium carbonate, calcium hydroxide, calcium oxide, magnesium chloride, magnesium sulfate, magnesium carbonate, magnesium hydroxide, magnesium oxide, aluminum sulfate, sodium aluminum sulfate (sodium alum), potassium aluminum sulfate (potassium alum), etc. However, from the viewpoint of solubility in water, ease of handling, and cost, ethylenediamine hydrochloride, calcium chloride, magnesium chloride, and aluminum sulfate are preferred, and calcium chloride and magnesium chloride are more preferred.

[0066] Furthermore, neutralization and bonding via a divalent or higher cation can be achieved simultaneously by neutralizing the acidic group of marine biodegradable polymer compound A with a base of two or more valents.

[0067] A preferred example of this method is to prepare a solution by dissolving or dispersing marine biodegradable polymer compound A in water, an organic solvent, or a mixture thereof, or a molten solution by heating and dissolving marine biodegradable polymer compound A. At this time, heating may be done as necessary to improve solubility or to reduce the viscosity of the molten solution. Next, a solution of a divalent or higher base is added to the obtained solution, dispersion, or molten solution and stirred. Alternatively, a solution, dispersion, or molten solution of marine biodegradable polymer compound A dissolved in a solution of a divalent or higher base may be added and stirred.

[0068] Examples of the aforementioned bases with a valency of 2 or more include the aforementioned polyvalent amines as organic bases, and magnesium hydride, strontium hydride, calcium hydride, barium hydride, magnesium methoxide, calcium methoxide, strontium methoxide, barium methoxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, magnesium oxide, strontium oxide, calcium oxide, barium oxide, magnesium carbonate, strontium carbonate, calcium carbonate, barium carbonate, magnesium bicarbonate, strontium bicarbonate, calcium bicarbonate, and barium bicarbonate, among others. However, ethylenediamine, calcium hydride, calcium methoxide, calcium hydroxide, barium hydroxide, and strontium hydroxide are preferred in terms of solubility in water, reactivity, cost, etc., and calcium hydroxide is more preferred.

[0069] The concentration of the polyvalent salt in the solution containing the polyvalent salt, or the concentration of the base in the solution containing a base of 2 or more valents, is preferably 1 to 40% by mass, and more preferably 10 to 30% by mass. The solvent of the solution is preferably a lower alcohol solvent such as water, methanol, ethanol, 1-propanol, 2-propanol, amphiphilic solvents such as acetone, acetonitrile, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, 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.

[0070] Furthermore, if the polyvalent salt or divalent or more base is highly reactive and reacts even in a solid state, it may be used in powder form without a medium, or dispersed in a small amount of a medium.

[0071] In this way, the polyester-type polyvalent anions contained in marine biodegradable polymer compounds A or B can be bonded via divalent or higher cations, and the target marine biodegradable polymer compound C, which has gradually become insoluble, is obtained as precipitate, sediment, or bulk. The processing time is preferably 0.5 to 24 hours, and more preferably 1 to 12 hours.

[0072] In this case, for the purpose of controlling the particle size and shape (such as spherical) of the precipitate or sediment, a surfactant or polymer stabilizer may be dissolved in at least one of a solution containing marine biodegradable polymer compound A or B, and a solution containing a divalent or polyvalent base or polyvalent salt.

[0073] Heating may be performed when precipitating or precipitation the target marine biodegradable polymer compound C. Heating may be performed when mixing a solution containing a dissolved or dispersed marine biodegradable polymer compound A or B, or a molten marine biodegradable polymer compound A or B, with a solution containing a polyvalent salt or a base of two or more progenitors, or when stirring after mixing, or both. The heating temperature is preferably 15 to 150°C, more preferably 20 to 100°C, and more preferably 40 to 80°C.

[0074] After processing, marine biodegradable polyester C can be obtained by washing the resin as needed. Washing can be carried out by conventional methods, such as removing the solvent after bonding and adding water, followed by centrifugation or decantation.

[0075] After washing, marine biodegradable polyester C can be obtained by drying as needed. Drying can be carried out by conventional methods, such as spray drying, vacuum drying, or freeze-drying. The drying process may also involve stirring or heating, and if heating is used, a temperature of 30 to 200°C is preferred, 40 to 190°C is more preferred, and 60 to 180°C is even more preferred.

[0076] After drying, heating may be performed to improve fluidity when extracting marine biodegradable polyester C, in which case a temperature of 20 to 180°C is preferred, 30 to 160°C is more preferred, and 40 to 140°C is even more preferred.

[0077] Furthermore, the obtained marine biodegradable polyester C may be subjected to surface treatment or pulverization to adjust its particle size using known equipment, if necessary.

[0078] Furthermore, marine biodegradable polymer compound C containing anions derived from other anionic compounds can be produced by using a medium in which the aforementioned marine biodegradable polymer compound A or B is dissolved or dispersed, or by adding an anionic compound to the molten solution of marine biodegradable polymer compound A or B.

[0079] The marine biodegradable polymer compound C may have at least one of its ends that are not bonded to the polyester-type polyvalent anions via a divalent cation sealed with a sealing segment group.

[0080] By selecting the appropriate sealing segment group, multiple effects can be incorporated in single materials and composite materials (marine biodegradable compositions) using this material, such as adjustment of melt temperature and melt viscosity, adjustment of crystallinity, adjustment of microbial adhesion and biodegradability, adjustment of physical properties such as resin tensile strength, flexural strength, and elasticity, improvement of compatibility with resins, adjustment of hydrophobicity, adjustment of water repellency, adjustment of adhesion, and adjustment of plasticity. This allows for improvements in both the biodegradability and physical properties of marine biodegradable compositions. Since the organic anion that forms the sealing segment is desirable to have a structure that is biodegradable in the ocean, it is desirable to select a sealing segment group with a molecular weight of 5000 or less that is biodegradable in the ocean. For example, when prioritizing the biodegradation rate in the ocean and maintaining average physical properties, a molecular weight of 2500 or less is preferred, and a molecular weight of 1000 or less is more preferred.

[0081] Specifically, the sealing segment group is preferably one having a monovalent hydrocarbon group with 3 or more carbon atoms, more preferably one having a monovalent hydrocarbon group with 6 or more carbon atoms, even more preferably one having a monovalent hydrocarbon group with 10 or more carbon atoms, and most preferably one having a monovalent hydrocarbon group with 12 or more carbon atoms. The upper limit of the number of carbon atoms in the monovalent hydrocarbon group is not particularly limited, but is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less.

[0082] The sealing segment group is preferably a monovalent organic anion selected from a carboxylic acid anion having 3 or more C3 monovalent hydrocarbon groups, a sulfonic acid anion having 3 or more C3 monovalent hydrocarbon groups, a sulfate ester anion having 3 or more C3 monovalent hydrocarbon groups, and a phosphate ester anion having 3 or more C3 monovalent hydrocarbon groups. Of these, it is preferably a monovalent organic anion derived from a carboxylic acid having 3 or more C3 monovalent hydrocarbon groups, and more preferably a monovalent organic anion derived from a fatty acid having 3 or more C3 monovalent hydrocarbon groups or an amino acid derivative having 3 or more C3 monovalent hydrocarbon groups.

[0083] End encapsulation can be performed using at least one end encapsulant selected from carboxylic acids having three or more C3 or more monovalent hydrocarbon groups, salts of the carboxylic acid, sulfonic acids having three or more C3 or more monovalent hydrocarbon groups, salts of the sulfonic acid, sulfate esters having three or more C3 or more monovalent hydrocarbon groups, salts of the sulfate esters, phosphate esters having three or more C3 or more monovalent hydrocarbon groups, and salts of the phosphate esters. End encapsulation can be performed by adding the end encapsulant to a solution containing polymer compound A or B, and then binding with polyvalent metal ions.

[0084] As the end-capturing agent, acid compounds or salt compounds described in paragraphs

[0029] to

[0044] of Japanese Patent Application Publication No. 2021-191810 are preferred.

[0085] [Marine biodegradable composition] The marine biodegradable composition of the present invention comprises at least one selected from the marine biodegradable polymer compounds A, B, and C.

[0086] The marine biodegradable polymer compound may be used as the main raw material, or it may be used as an additive in combination with other resins. The other resins are not particularly limited, but are preferably biodegradable resins. In this case, the composite resin will be a composition that promotes biodegradation in the ocean. Furthermore, in order to adjust the physical properties and handling characteristics of the composition, multiple types of resins may be used in combination as the other resins.

[0087] Other resins include polyethylene, polyester, polypropylene, polyethylene terephthalate, 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 and the effect of promoting marine biodegradability, resins with high biodegradability are particularly preferred.

[0088] 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), poly(tetramethylene adipate / terephthalate), polyethylene succinate, polyvinyl alcohol, polyglycolic acid, glycolic acid / caprolactone copolymer, glycolic acid / trimethylene carbonate copolymer, etc., which are resins derived from petroleum; (polylactic acid / polybutylene succinate-based) block copolymer, (polylactic acid / polycaprolactone) copolymer, (polylactic acid / polyether) copolymer, Examples of resins include those made from partially biomass-derived raw materials such as polylactic acid blend PBAT, lactic acid / glycolic acid copolymer, biopolybutylene succinate, poly(butylene succinate / adipate), starch blend polyester resin, and poly(butylene succinate terephthalate) (PBST); resins made from 100% biomass-derived raw materials such as polyhydroxyalkanoates like polyhydroxybutyric acid, polyhydroxyvaleric acid, polyhydroxycaprylic acid, poly(hydroxybutyrate / hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate / 4-hydroxybutyrate) (P3HB4HB), and poly(hydroxybutyrate / hydroxyvaleric acid) (PHBV), and polylactic acid (PLA); and resins made from natural polymers such as cellulose, cellulose acetate, cellulose ester resin, starch, esterified starch, and chitosan. These may be used individually or in combination of two or more types.

[0089] Of these, it is preferable to combine a biodegradable resin, selected from resins that are biodegradable in soil or compost but have poor biodegradability in the ocean, such as polycaprolactone, PBS, PBSA, PBAT, PBST, poly(tetramethylene adipate / terephthalate), poly(butylene succinate / carbonate), polyhydroxyalkanoates such as PHBH, PHBV, PLA, cellulose, starch, polylactic acid blend PBAT, chitosan, and other resins derived from natural polymers, with the marine biodegradable polymer compound. Among these, resins derived from PBSA, PBS, PBAT, PBST, PLA, starch, and polylactic acid blend PBAT are particularly preferred as the biodegradable resin.

[0090] From the viewpoint of thermal and mechanical properties and biodegradability, preferred combinations of the biodegradable resin and the marine biodegradable polymer compound are as follows: when all polyvalent carboxylic acid residues of the marine biodegradable polymer compound are aliphatic carboxylic acid residues, the biodegradable resin is preferably PBSA, PBS, PLA, PHBV, or PHBH, and more preferably PBSA or PBS. Furthermore, when the polyvalent carboxylic acid residues of the marine biodegradable polymer compound include aliphatic carboxylic acid residues and aromatic carboxylic acid residues, the biodegradable resin is preferably PBAT, PBST, PLA, starch, or polylactic acid blend PBAT, and more preferably PBAT, starch, or polylactic acid blend PBAT. With these combinations of biodegradable resin and marine biodegradable polymer compound, the change in the physical properties of the biodegradable resin due to compounding is small, and the effect of promoting biodegradation is large.

[0091] Furthermore, considering the reduction of environmental impact, the raw materials for the resin to be combined are preferably 20% or more biomass-derived, more preferably 50% or more biomass-derived, and most preferably 100% biomass-derived.

[0092] The marine biodegradable composition of the present invention may contain a solvent. The solvent may dissolve the resin matrix while leaving the marine biodegradable polymer compound as particles, or it may dissolve both the resin and the marine biodegradable polymer compound. By appropriately adjusting these, the composition can be used as a molded product formed into a film by casting, or as a paint, ink, surface treatment agent, etc. Preferred solvents include, for example, water, formic acid, hexane, heptane, acetonitrile, N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, dimethyl sulfone, acetone, methyl ethyl ketone, diethyl ketone, acetophenone, dimethyl ether, dipropyl ether, tetrahydrofuran, chloroform, methylene chloride (dichloromethane), trichloroethylene, dichloroethylene, tetrachloroethane, chlorobenzene, methanol, ethanol, n-propanol, isopropanol, butanol, pentanol, hexafluoroisopropanol, methyl glycol, methyl triglyceride, hexyl glycol, phenyl glycol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, benzene, toluene, and xylene. These may be used individually or in combination of two or more.

[0093] When a solvent is used, the total concentration of the resin and marine biodegradable polymer compound in the 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 the marine biodegradable polymer compound to the resin is preferably 99:1 to 10:90 by mass ratio, more preferably 97:3 to 40:60, even more preferably 95:5 to 50:50, and most preferably 90:10 to 60:40.

[0094] The lower limit of the softening point of the composition is preferably 50°C, 60°C, and 70°C, in that order, and the upper limit is preferably 250°C, 200°C, and 180°C, in that order. Preferably, the softening point is in the range of 50 to 250°C, more preferably 60 to 200°C, and even more preferably 70 to 180°C.

[0095] Furthermore, the marine biodegradable 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 biodegradable polymer compound may be added and mixed thereto, or the resin and the marine biodegradable polymer compound may be melted together and mixed.

[0096] In the marine biodegradable composition of the present invention, the content of the marine biodegradable polymer compound is preferably 1 to 60% by mass, 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 preferably 40 to 99% by mass, more preferably 50 to 97% by mass, even more preferably 55 to 95% by mass, still more preferably 60 to 93% by mass, and most preferably 65 to 90% by mass. By including the marine biodegradable polymer compound within the above range, the marine biodegradable composition of the present invention can be used as a marine biodegradation accelerator that promotes biodegradation in seawater while maintaining the physical properties of the biodegradable resin. The marine biodegradable polymer compound may be used alone or in combination of two or more types.

[0097] The tensile strength of the test specimen obtained from the composition is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more, compared to a blank resin test specimen that does not contain the marine biodegradable polymer compound of the present invention, when the content of the marine biodegradable polymer compound in the composition is 10% by mass. Furthermore, when the content of the marine biodegradable polymer compound in the composition is 30% by mass, the tensile strength is preferably 65% ​​or more, more preferably 70% or more, and even more preferably 80% or more.

[0098] The marine biodegradable 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 is preferably about 0.1 to 50 parts by mass per 100 parts by mass of resin.

[0099] If the marine biodegradable composition contains a solvent, it can be prepared, for example, by adding the resin, the marine biodegradable polymer compound, and the additives as needed to the solvent simultaneously or in any order and mixing them. If the marine biodegradable composition does not contain a solvent, for example, the resin may be melted, and the marine biodegradable polymer compound and the additives as needed may be added simultaneously or in any order and mixed; or the resin and the marine biodegradable polymer compound may be heated to melt them together and mixed, and the additives as needed may be added and mixed.

[0100] [Molded body] By molding using the aforementioned marine biodegradable composition, a molded article can be obtained in which the marine biodegradable polymer compound is dispersed or dissolved in the resin. If the composition contains a solvent, the composition can be used as is for molding; if the composition does not contain a solvent, the resin in the composition, or the resin and marine biodegradable polymer compound, can be melted by heat before molding.

[0101] 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.

[0102] [Application] The marine biodegradable polymer compounds and marine biodegradable compositions of the present invention can be used as raw materials for plastic molded products, and as various additives to molded products such as liquids, coatings, films, plates, and paper. When used as raw materials for plastic molded products, they can be used as raw materials for general-purpose applications such as films, packaging, containers, trays, laminates, adhesives, coatings, medical and clothing fibers, shoes, belts, tires, tubes, shock absorbers, fishing lines, fishing nets, and marine applications, and are particularly suitable as raw materials for marine applications. Furthermore, when used as an additive, it can be widely used as an additive for various applications, such as light scattering agents, optical filter materials, colorants, cosmetics, absorbents, adsorbents, inks, adhesives, electromagnetic shielding materials, fluorescent sensors, biomarkers, recording materials, recording elements, polarizing materials, drug holders for drug delivery systems (DDS), biosensors, DNA chips, diagnostic reagents, calcined porous molded products, antiblocking agents, additives for printing inks used in screen printing, offset printing, process printing, gravure printing, pad printing, coaters, inkjet printers, etc., additives for writing instrument inks such as marking pens, ballpoint pens, fountain pens, brush pens, and markers, additives for stationery such as crayons, paints, and erasers, and additives for paints used in brush painting, spray painting, electrostatic painting, electrodeposition painting, pouring, roller painting, and dipping painting, particularly as an additive for paints used in marine applications such as ship hull paints. [Examples]

[0103] The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the following examples and comparative examples, the metal ion equivalent was measured by emission analysis using ICP-MS (ICPE-9820, Shimadzu Corporation) after heating and decomposing the target substance with nitric acid or aqua regia. The organic cation equivalent was measured using LC-MS / MS (Triple Quad 3500, AB Sci-X Co., Ltd.) after decrosslinking the target substance by immersing it in brine or a solution containing a chelating agent. The number-average molecular weight and the composition ratio of carboxylic acid residues in the polyester were measured using a nuclear magnetic resonance spectrometer (JNM-ECZ400S, JEOL Ltd.).1 The molecular weight was calculated from the integrated peak values ​​in 1H-NMR. GPC was performed using Shimadzu Corporation's Prominence (COM-20A, LC-20A, SIL-20A, RID-20A, SPD-20A, CTO-20A) with chloroform (1.0 mL / min) as the mobile phase, and the sample was adjusted to a concentration of 5 mg / mL. The molecular weight was evaluated as the relative molecular weight in terms of polystyrene. The softening temperature was determined using a thermomechanical analyzer (NETZSCH Japan Co., Ltd. TMA4000SE).

[0104] [1] Synthesis of marine biodegradable polymer compound A [Example 1-1] Synthesis of marine biodegradable polymer compound A-1 In a 1L flask, 69.6g of dimethyl adipate, 234g of dimethyl succinate, 200g of 1,4-butanediol, and 2.84g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. After cooling to room temperature, 10mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of adipic acid residues to succinic acid residues was 20:80. Subsequently, 37.8 g of acetonitrile and 44.1 g of succinic anhydride were added and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray with a Teflon® sheet to obtain marine biodegradable polymer compound A-1 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 2000.

[0105] [Examples 1-2] Synthesis of marine biodegradable polymer compound A-2 In a 1L flask, 182g of dimethyl sebacate, 115g of dimethyl succinate, 200g of 3-methyl-1,5-pentanediol, and 2.24g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. After cooling to room temperature, 10mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of sebaciate residues to succinic acid residues was 50:50. Subsequently, 39.8 g of acetonitrile and 29.2 g of maleic anhydride were added and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray lined with a Teflon® sheet to obtain marine biodegradable polymer compound A-2 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 3000.

[0106] [Examples 1-3] Synthesis of marine biodegradable polymer compound A-3 In a 1L flask, 302g of dimethyl adipate, 99.7g of dimethyl sebacate, 200g of 1,4-butanediol, and 3.07g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. After cooling to room temperature, 10mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of adipic acid residues to sebaciic acid residues was 80:20. Subsequently, 46.6 g of acetonitrile and 12.3 g of maleic anhydride were added and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray with a Teflon® sheet to obtain marine biodegradable polymer compound A-3 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 8000.

[0107] [Examples 1-4] Synthesis of marine biodegradable polymer compound A-4 In a 1L flask, 170g of dimethyl adipate, 155g of dimethyl terephthalate, 200g of 1,4-butanediol, and 2.52g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. After cooling to room temperature, 10mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of adipic acid residues to terephthalic acid residues was 55:45. Subsequently, 41.4 g of acetonitrile and 109 g of succinic anhydride were added, and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray lined with a Teflon® sheet to obtain marine biodegradable polymer compound A-4 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1 1H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, resulting in a number-average molecular weight of 1000.

[0108] [Examples 1-5] Synthesis of marine biodegradable polymer compound A-5 In a 1L flask, 304g of dimethyl adipicate, 42.4g of dimethyl terephthalate, 42.4g of dimethyl isophthalate, 200g of 1,4-butanediol, and 3.10g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. After cooling to room temperature, 10mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of adipic acid residues, terephthalic acid residues, and isophthalic acid residues was 80:10:10. Subsequently, 45.2 g of acetonitrile and 8.06 g of succinic anhydride were added and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray with a Teflon® sheet to obtain marine biodegradable polymer compound A-5 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 12,000.

[0109] [Examples 1-6] Synthesis of marine biodegradable polymer compound A-6 In a 1L flask, 209g of dimethyl adipate, 116g of dimethyl terephthalate, 31.2g of franzicarboxylic acid, 200g of 1,4-butanediol, and 2.84g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. After cooling to room temperature, 10mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of adipic acid residues, terephthalic acid residues, and frangic acid residues was 60:30:10. Subsequently, 43.7 g of acetonitrile and 79.8 g of phthalic anhydride were added and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray with a Teflon® sheet to obtain marine biodegradable polymer compound A-6 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 2000.

[0110] [Examples 1-7] Synthesis of marine biodegradable polymer compound A-7 In a 1L flask, 281g of dimethyl adipate, 134g of dimethyl terephthalate, 200g of 1,4-butanediol, 22.7g of glycerol, and 3.27g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a branched polyester having hydroxyl groups at each end. After cooling to room temperature, 10mg was taken from the contents of the flask. 1¹H-NMR analysis revealed that the ratio of adipic acid residues to terephthalic acid residues was 70:30. Subsequently, 49.3 g of acetonitrile and 37.0 g of succinic anhydride were added and the mixture was heated and stirred at 130°C for 4 hours. After that, the contents were removed from the mixture into a stainless steel tray lined with a Teflon® sheet to obtain marine biodegradable polymer compound A-7 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 3000.

[0111] [Examples 1-8] Synthesis of marine biodegradable polymer compound A-8 In a 1L flask, 228g of dimethyl sebacate, 22.3g of dimethyl succinate, 74.0g of dimethyl terephthalate, 200g of 3-methyl-1,5-pentanediol, and 2.16g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. After cooling to room temperature, 10mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of sebaciate, succinic acid, and terephthalic acid residues was 65:10:25. Subsequently, 42.9 g of acetonitrile and 49.0 g of maleic anhydride were added, and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray with a Teflon® sheet to obtain marine biodegradable polymer compound A-8 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 2000.

[0112] [Examples 1-9] Synthesis of marine biodegradable polymer compound A-9 201 g of dimethyl adipate, 149 g of dimethyl terephthalate, 200 g of 1,4-butanediol, and 2.73 g of titanium tetraisopropoxide were added to a 1 L flask and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. After cooling to room temperature, 10 mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of adipic acid residues to terephthalic acid residues was 60:40. Subsequently, 43.0 g of acetonitrile and 69.5 g of succinic anhydride were added and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray lined with a Teflon® sheet to obtain marine biodegradable polymer compound A-9 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 1500.

[0113] [Examples 1-10] Synthesis of marine biodegradable polymer compound A-10 In a 1L flask, 311g of dimethyl adipate, 92.6g of dimethyl terephthalate, 29.1g of dimethyl 2,6-naphthalenedicarboxylate, 200g of 1,4-butanediol, 22.7g of glycerol, and 3.39g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a branched polyester having hydroxyl groups at each end. After cooling to room temperature, 10mg was taken from the contents of the flask. 1 ¹H-NMR analysis revealed that the molar ratio of adipic acid residues, terephthalic acid residues, and 2,6-naphthalenedicarboxylic acid residues was 75:20:5. Subsequently, 50.7 g of acetonitrile and 18.4 g of succinic anhydride were added and the mixture was heated and stirred at 130°C for 4 hours. The contents were then removed from the mixture into a stainless steel tray with a Teflon® sheet to obtain marine biodegradable polymer compound A-10 as a solid resin. 20 mg was taken from the obtained resin, and 10 mg of each was used... 1¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 6000.

[0114] [Comparative Example 1-1] Synthesis of Polymer Compound X-1 In a 1L flask, 348g of dimethyl adipate, 200g of 1,4-butanediol, and 2.84g of titanium tetraisopropoxide were added and heated and stirred at 160°C for 6 hours to obtain a linear polyester having hydroxyl groups at both ends. Subsequently, 42.3g of acetonitrile and 49.4g of succinic anhydride were added and heated and stirred at 130°C for 4 hours. After that, the contents were transferred to a stainless steel tray with a Teflon® sheet to obtain X-1 as a solid resin. 20mg was taken from the obtained resin, and 10mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, and the number-average molecular weight was 2000.

[0115] [Comparative Example 1-2] Synthesis of Polymer Compound X-2 In a 1L flask, 388g of dimethyl terephthalate, 200g of 1,4-butanediol, and 2.84g of titanium tetraisopropoxide were added and heated and stirred at 200°C for 6 hours to obtain a linear polyester with hydroxyl groups at both ends. Subsequently, 46.3g of acetonitrile and 54.0g of succinic anhydride were added and heated and stirred at 150°C for 4 hours. After that, the contents were transferred to a stainless steel tray with a Teflon® sheet to obtain X-2 as a solid resin. 20mg was taken from the obtained resin, and 10mg of each was used... 1 ¹H-NMR and GPC measurements revealed that all terminal hydroxyl groups had reacted, resulting in a number-average molecular weight of 2000.

[0116] Table 1 below shows the marine biodegradable polymer compounds A-1 to A-10 and polymer compounds X-1 and X-2 together.

[0117] [Table 1]

[0118] [2] Synthesis of marine biodegradable polymer compound B

[0119] [Example 2-1] Synthesis of marine biodegradable polymer compound B-1 300 g of marine biodegradable polymer compound A-1 and 289 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 20.1 g of 28% aqueous ammonia was added and stirred for a further 30 minutes at 90°C to obtain marine biodegradable polymer compound B-1 as a 50% by mass aqueous solution, in which 100% of the protons of the acidic group of marine biodegradable polymer compound A-1 were replaced with ammonium ions.

[0120] [Example 2-2] Synthesis of marine biodegradable polymer compound B-2 300 g of marine biodegradable polymer compound A-2 and 302 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 15.2 g of potassium carbonate was added and stirred for another 30 minutes at 90°C to obtain marine biodegradable polymer compound B-2 as a 50% by mass aqueous solution, in which 100% of the protons of the acidic group of marine biodegradable polymer compound A-2 were replaced with potassium.

[0121] [Examples 2-3] Synthesis of marine biodegradable polymer compound B-3 300 g of marine biodegradable polymer compound A-3 and 297 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 4.37 g of sodium carbonate was added and stirred for a further 30 minutes at 90°C to obtain marine biodegradable polymer compound B-3 as a 50% by mass aqueous solution, in which 100% of the protons of the acidic group of marine biodegradable polymer compound A-3 were replaced with sodium.

[0122] [Examples 2-4] Synthesis of marine biodegradable polymer compound B-4 300 g of marine biodegradable polymer compound A-4 and 305 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 45.6 g of potassium carbonate was added and stirred for another 30 minutes at 90°C to obtain marine biodegradable polymer compound B-4 as a 50% by mass aqueous solution, in which 100% of the protons of the acidic group of marine biodegradable polymer compound A-4 were replaced with potassium.

[0123] [Examples 2-5] Synthesis of marine biodegradable polymer compound B-5 300 g of marine biodegradable polymer compound A-5 and 304 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 2.91 g of sodium carbonate was added and stirred for a further 30 minutes at 90°C to obtain marine biodegradable polymer compound B-5 as a 50% by mass aqueous solution, in which 100% of the protons of the acidic group of marine biodegradable polymer compound A-5 were replaced with sodium.

[0124] [Examples 2-6] Synthesis of marine biodegradable polymer compound B-6 300 g of marine biodegradable polymer compound A-6 and 306 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 18.5 g of potassium hydroxide was added and the mixture was stirred for another 30 minutes at 90°C to obtain marine biodegradable polymer compound B-6 as a 50% by mass aqueous solution, in which 100% of the protons in the acidic groups of marine biodegradable polymer compound A-6 were replaced with potassium.

[0125] [Examples 2-7] Synthesis of marine biodegradable polymer compound B-7 300 g of marine biodegradable polymer compound A-7 and 305 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 2.90 g of sodium hydroxide and 5.02 g of potassium carbonate were added and stirred for a further 30 minutes at 90°C to obtain marine biodegradable polymer compound B-7 as a 50% by mass aqueous solution, in which 66% of the protons of the acidic groups of marine biodegradable polymer compound A-7 were replaced with sodium or potassium.

[0126] [Examples 2-8] Synthesis of marine biodegradable polymer compound B-8 300 g of marine biodegradable polymer compound A-8 and 304 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 10.0 g of 28% by mass aqueous ammonia was added and stirred for a further 30 minutes at 90°C to obtain marine biodegradable polymer compound B-8 as a 50% by mass aqueous solution, in which 50% of the protons of the acidic group of marine biodegradable polymer compound A-8 were replaced with ammonium ions.

[0127] [Examples 2-9] Synthesis of marine biodegradable polymer compound B-9 300 g of marine biodegradable polymer compound A-9 and 304 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 30.4 g of potassium carbonate was added and stirred for another 30 minutes at 90°C to obtain marine biodegradable polymer compound B-9 as a 50% by mass aqueous solution, in which 100% of the protons of the acidic group of marine biodegradable polymer compound A-9 were replaced with potassium.

[0128] [Example 2-10] Synthesis of marine biodegradable polymer compound B-10 300 g of marine biodegradable polymer compound A-10 and 302 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 6.17 g of potassium hydroxide was added and the mixture was stirred for another 30 minutes at 90°C to obtain marine biodegradable polymer compound B-10 as a 50% by mass aqueous solution, in which 100% of the protons in the acidic groups of marine biodegradable polymer compound A-10 were replaced with potassium.

[0129] [Comparative Example 2-1] Synthesis of Polymer Compound Y-1 300 g of marine biodegradable polymer compound X-1 and 303 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 22.8 g of potassium carbonate was added and stirred for another 30 minutes at 90°C to obtain marine biodegradable polymer compound Y-1 as a 50% by mass aqueous solution, in which 100% of the protons of the acidic groups of polymer compound X-1 were replaced with potassium.

[0130] [Comparative Example 2-2] Synthesis of Polymer Compound Y-2 300 g of marine biodegradable polymer compound X-2 and 302 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 22.7 g of potassium carbonate was added and stirred for another 30 minutes at 90°C to obtain marine biodegradable polymer compound Y-2 as a 50% by mass aqueous solution, in which 100% of the protons of the acidic groups of polymer compound X-2 were replaced with potassium.

[0131] Table 2 below shows the marine biodegradable polymer compounds B-1 to B-10 and polymer compounds Y-1 and Y-2 together.

[0132] [Table 2]

[0133] [3] Synthesis of marine biodegradable polymer compound C

[0134] [Example 3-1] Synthesis of marine biodegradable polymer compound C-1 609 g of a 50% by mass aqueous solution of marine biodegradable compound B-1 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 111 g of a 30% by mass aqueous solution of calcium chloride was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-1.

[0135] [Example 3-2] Synthesis of marine biodegradable polymer compound C-2 617 g of a 50% by mass aqueous solution of marine biodegradable compound B-2 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 76.0 g of a 30% by mass aqueous solution of aluminum sulfate was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-2.

[0136] [Example 3-3] Synthesis of marine biodegradable polymer compound C-3 602 g of a 50% by mass aqueous solution of marine biodegradable compound B-3 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 23.8 g of a 30% by mass aqueous solution of magnesium chloride was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-3.

[0137] [Examples 3-4] Synthesis of marine biodegradable polymer compound C-4 542 g of a 50% by mass aqueous solution of marine biodegradable compound B-4 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 185 g of a 30% by mass aqueous solution of calcium chloride was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-4.

[0138] [Examples 3-5] Synthesis of marine biodegradable polymer compound C-5 607 g of a 50% by mass aqueous solution of marine biodegradable compound B-5 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 15.9 g of a 30% by mass aqueous solution of magnesium chloride was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-5.

[0139] [Examples 3-6] Synthesis of marine biodegradable polymer compound C-6 In a 1L flask, 180g of a 50% by mass aqueous solution of marine biodegradable compound B-6 and 300g of a 30% sodium myristoyl sarcosinate (SMS) solution were added and the mixture was heated to 80°C over 30 minutes while stirring. Then, 139g of a 30% by mass aqueous solution of aluminum sulfate was added and stirred, which produced a precipitate. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-6.

[0140] [Examples 3-7] Synthesis of marine biodegradable polymer compound C-7 In a 1 L reaction vessel, 201 g of polyester diol (Kuraray Polyol P-1010, manufactured by Kuraray Co., Ltd.), 42.3 g of succinic anhydride, and 20.1 g of acetonitrile were charged and stirred at 130°C for 2 hours. Then, 245 g of water and 30.9 g of potassium carbonate were added and stirred at 80°C for 30 minutes to obtain an aqueous solution of polymer compound P-1 at 50% by mass. In a 1L round-bottom flask, 280g of a 50% by mass aqueous solution of marine biodegradable compound B-7, 40g of a 50% by mass aqueous solution of P-1, and 200g of a 20% by mass aqueous solution of dodecanoyl sarcosinate sodium (SDS) were added and the mixture was heated to 80°C over 30 minutes while stirring. Then, 95.8g of a 30% by mass aqueous solution of calcium chloride was added and stirred, which produced a precipitate. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-7.

[0141] [Examples 3-8] Synthesis of marine biodegradable polymer compound C-8 300 g of marine biodegradable polymer compound A-8 and 300 g of water were added to a 1 L flask and stirred at 80°C for 30 minutes. Subsequently, 9.92 g of a 50% by mass aqueous solution of ethylenediamine (EDA) was added and stirred for a further 30 minutes at 90°C until a precipitate formed. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-8.

[0142] [Examples 3-9] Synthesis of marine biodegradable polymer compound C-9 528 g of a 50% by mass aqueous solution of marine biodegradable compound B-9 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 123 g of a 30% by mass aqueous solution of calcium chloride was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-9.

[0143] [Example 3-10] Synthesis of marine biodegradable polymer compound C-10 609 g of a 50% by mass aqueous solution of marine biodegradable compound B-10 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 37.0 g of a 30% by mass aqueous solution of calcium chloride was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound C-10.

[0144] [Comparative Example 3-1] Synthesis of marine biodegradable polymer compound Z-1 521 g of a 50% by mass aqueous solution of marine biodegradable compound Y-1 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 79.4 g of a 30% by mass aqueous solution of magnesium chloride was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound Z-1.

[0145] [Comparative Example 3-2] Synthesis of Polymer Compound Z-2 521 g of a 50% by mass aqueous solution of marine biodegradable compound Y-2 was added to a 1 L flask and heated to 80°C over 30 minutes while stirring. Then, 92.5 g of a 30% by mass aqueous solution of calcium chloride was added and stirred, causing a precipitate to form. After washing the precipitate with water, it was dried under reduced pressure to obtain marine biodegradable polymer compound Z-2.

[0146] Table 3 below shows marine biodegradable polymer compounds C-1 to C-10 and polymer compounds Z-1 and Z-2 together. [Table 3]

[0147] [4] Biodegradability testing of marine biodegradable polymer compounds [Examples 4-1 to 4-10, 5-1 to 5-10, 6-1 to 6-10, Comparative Examples 4-1 to 4-2, 5-1 to 5-2, 6-1 to 6-2] The marine biodegradable polymer compounds A-1 to A-10, B-1 to B-10, and C-1 to C-10, as well as polymer compounds X-1, X-2, Y-1, Y-2, Z-1, and Z-2, were subjected to seawater biodegradation tests using the following method. Microcrystalline cellulose (Avicel PH-101, manufactured by Sigma-Aldrich) was used as a control material, and the relative biodegradation rate of the cellulose was evaluated. The results are shown in Tables 4 to 6.

[0148] <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.

[0149] [Table 4]

[0150] [Table 5]

[0151] [Table 6]

[0152] As shown in Tables 4-6, marine biodegradable polymer compounds A, B, and C all exhibited biodegradability, achieving a relative degradation of 40% or more of cellulose by 60 days of culture.

[0153] [5] Preparation of marine biodegradable compositions and confirmation tests in seawater - 1 (1) Surface changes [Examples 7-1 to 7-12, Comparative Examples 7-1 to 7-3] PBSA (FD-92, manufactured by Mitsubishi Chemical Corporation), a biodegradable resin, was pulverized using a pulverizer (Wonder Blender WB-1, manufactured by Osaka Chemical Co., Ltd.). Marine biodegradable polymer compounds C-1 to C-10, A-4, B-8, and polymer compounds Z-1 and Z-2, classified using a stainless steel sieve (mesh size 26 μm), were melt-kneaded 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 200 μm. In addition, PBSA itself (without marine biodegradable polymer compounds) was press-molded at 150°C to produce a film with a thickness of 200 μm (Comparative Example 7-3). Furthermore, the obtained films were processed into 10 mm squares and placed in 200 mL of deionized water and 200 mL of seawater (collected from Tokyo Bay [Chiba Prefecture: Chiba Port]), respectively. After standing at 25°C for 7 and 30 days, the films were removed and their surfaces and appearance were observed using a scanning electron microscope. The results are shown in Table 7.

[0154] [Table 7]

[0155] Based on the results shown in Table 7, it is considered that biodegradation is accelerated by the presence of microorganisms in the seawater, in addition to the breakdown caused by seawater.

[0156] (2) Weight reduction of composite resin [Examples 8-1 to 8-12, Comparative Examples 8-1 to 8-3] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-10, A-4, B-8, and polymer compounds Z-1 and Z-2 to PBSA, respectively, as well as a film of PBSA alone. The obtained films were processed into 20 mm squares, sandwiched between stainless steel nets, and immersed in seawater (collected from Tokyo Bay [Chiba Prefecture: Chiba Port]) in a 15 L tank. The weight loss after immersion was observed after 30, 60, and 90 days. The results are shown in Table 8.

[0157] [Table 8]

[0158] Based on the results shown in Table 8, it is considered that biodegradation is accelerated by the presence of microorganisms in the seawater, in addition to the breakdown caused by seawater.

[0159] (3) Measurement of tensile strength [Examples 9-1 to 9-12, Comparative Examples 9-1 to 9-3] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-10, A-4, B-8, and polymer compounds Z-1 and Z-2 to PBSA at concentrations of 10% by mass, 20% by mass, or 30% by mass, respectively, as well as a film of PBSA alone. Dumbbells were prepared from each film according to JIS K 7139-A22, and the tensile stress (yield point) was measured using a universal testing machine (MCT-2150, A&D Co., Ltd.). Each sample was measured five times, and the average value was taken as the tensile stress. The results are shown in Table 9.

[0160] [Table 9]

[0161] The results shown in Table 9 confirm that the marine biodegradable polymer compound of the present invention exhibits improved mechanical properties compared to Z-1.

[0162] (4) Softening point measurement [Examples 10-1 to 10-12, Comparative Examples 10-1, 10-2] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-10, A-4, B-8, and polymer compounds Z-1 and Z-2 to PBSA at concentrations of 10% by mass, 20% by mass, or 30% by mass, respectively, as well as a film of PBSA alone. The softening points were measured using a thermomechanical analyzer (TMA4000SE, manufactured by NETZSCH Japan Co., Ltd.). Specifically, a 1.5 mm thick, 3 mm square test piece was subjected to a 0.5 g load, and the softening point was defined as the temperature at which a 150 μm penetration was observed within a temperature range of 25 to 200 °C (heating rate of 3 °C / min). The results are shown in Table 10.

[0163] [Table 10]

[0164] The results shown in Table 10 confirm that the marine biodegradable polymer compound of the present invention exhibits improved thermophysical properties compared to Z-1.

[0165] [6] Preparation of marine biodegradable compositions and confirmation tests in seawater - 2 (1) Surface changes [Examples 11-1 to 11-12, Comparative Examples 11-1 to 11-3] A biodegradable starch-based resin (Mater-Bi EF05B, manufactured by Novamont) was pulverized using a pulverizer (Wonder Blender WB-1, manufactured by Osaka Chemical Co., Ltd.), and marine biodegradable polymer compounds C-1 to C-10, A-4, B-8, and polymer compounds Z-1 and Z-2 were classified using a stainless steel sieve (mesh size 26 μm). These were melt-kneaded at 150°C to a concentration of 20% by mass, and then press-molded at 160°C to produce a film with a thickness of 200 μm (Examples 11-1 to 11-9, Comparative Examples 11-1 and 11-2). In addition, a film with a thickness of 200 μm was produced by press-molding the starch-based resin itself (without marine biodegradable polymer compounds) at 160°C (Comparative Example 11-3). Furthermore, the obtained films were processed into 10 mm squares and placed in 200 mL of deionized water and 200 mL of seawater (collected from Tokyo Bay [Chiba Prefecture: Chiba Port]), respectively. After standing at 25°C for 7 and 30 days, the films were removed and their surfaces and appearance were observed using a scanning electron microscope. The results are shown in Table 11.

[0166] [Table 11]

[0167] Based on the results shown in Table 11, it is considered that biodegradation is accelerated by the presence of microorganisms in the seawater, in addition to the breakdown caused by seawater.

[0168] (2) Weight reduction of composite resin [Examples 12-1 to 12 to 12, Comparative Examples 12-1 to 12-2] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-10, A-2, B-6, and polymer compounds Z-1 and Z-2 to starch resin, respectively, as well as a film of starch resin alone. The obtained films were processed into 20 mm squares, sandwiched between stainless steel nets, and immersed in seawater (collected from Tokyo Bay [Chiba Prefecture: Chiba Port]) in a 15 L tank. The weight loss after immersion was observed after 30, 60, and 90 days. The results are shown in Table 12.

[0169] [Table 12]

[0170] Based on the results shown in Table 12, it is considered that biodegradation is accelerated by the presence of microorganisms in the seawater, in addition to the breakdown caused by seawater.

[0171] (3) Measurement of tensile strength [Examples 13-1 to 13-12, Comparative Examples 13-1 to 13-2] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-10, A-4, B-8, and polymer compounds Z-1 and Z-2 to a starch-based resin at concentrations of 10% by mass, 20% by mass, or 30% by mass, respectively, as well as films of the starch-based resin alone. Dumbbells were prepared from various films in accordance with JIS K 7139-A22, and the tensile stress (yield point) was measured using a universal testing machine (MCT-2150, manufactured by A&D Co., Ltd.). Each sample was measured five times, and the average value was taken as the tensile stress. The results are shown in Table 13.

[0172] [Table 13]

[0173] The results shown in Table 13 confirm that the marine biodegradable polymer compound of the present invention exhibits improved mechanical properties compared to Z-1.

[0174] (4) Softening point measurement [Examples 14-1 to 14-12, Comparative Examples 14-1, 14-2] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-10, A-4, B-8, and polymer compounds Z-1 and Z-2 to a starch-based resin at concentrations of 10% by mass, 20% by mass, or 30% by mass, respectively, as well as films of the starch-based resin alone. The softening points were measured using a thermomechanical analyzer (TMA4000SE, manufactured by NETZSCH Japan Co., Ltd.). Specifically, a 1.5 mm thick, 3 mm square test piece was subjected to a 0.5 g load, and the softening point was defined as the temperature at which a 150 μm penetration was observed within a temperature range of 25 to 200 °C (heating rate of 3 °C / min). The results are shown in Table 14.

[0175] [Table 14]

[0176] The results shown in Table 14 confirm that the marine biodegradable polymer compound of the present invention exhibits improved thermophysical properties compared to Z-1.

[0177] Based on the above results, the marine biodegradable polymer compound of the present invention dissolves or becomes more hydrophilic in seawater by being reduced in molecular weight or undergoing salt substitution through biodegradation prior to that of biodegradable resins. Therefore, by adding a marine biodegradation accelerator containing the marine biodegradable polymer compound of the present invention to resin compositions that are biodegradable in soil or compost, or resin compositions that have low biodegradability in the ocean, it becomes possible to create an uneven surface in seawater, facilitate the attachment of microorganisms, and promote biodegradation. As a result, it becomes possible to improve the overall marine biodegradability and reduce the environmental burden. By combining the marine biodegradable polymer compound of the present invention with a marine biodegradation accelerator that is biodegradable in soil or compost, seawater biodegradability can be improved. Furthermore, by appropriately changing the structure of the organic anion, multiple effects can be incorporated, such as adjusting the melting temperature and viscosity, adjusting the degree of crystallinity, adjusting microbial adhesion and biodegradability, adjusting physical properties such as resin tensile strength, flexural strength, and elasticity, improving compatibility with the resin, adjusting the degree of hydrophobicity, adjusting hydrophobicity, and adjusting adhesion and plasticity. Thus, improvements can be made to both the biodegradability and physical properties of the marine biodegradable composition.

Claims

1. A marine biodegradable polymer compound comprising a polyester-type polyvalent anion having a total of two or more monovalent anionic substituents at its termini, and a monovalent cation, comprising two or more polyvalent carboxylic acid residues and one or more polyvalent alcohol residues.

2. The marine biodegradable polymer compound according to claim 1, wherein the monovalent cation is a proton, a monovalent metal cation, or a monovalent organic cation.

3. The two or more polyvalent carboxylic acid residues mentioned above are all aliphatic carboxylic acid residues, and the ratio of aliphatic carboxylic acid residues with more than 4 carbon atoms to the total number of aliphatic carboxylic acid residues is r 1 Expressed as mol%, the number-average molecular weight is m 1 In this case, P is represented by the following equation (1). 1 The marine biodegradable polymer compound according to claim 1, wherein the value of is 0.250 to 0.

802. [Math 1] [In the formula, f(r 1 ), g(m 1 ) and h(r 1 , m 1 These values ​​are represented by the following formulas (1-1), (1-2), and (1-3), respectively. [Math 2] [Math 3] [Math 4] (In formulas (1-1) to (1-3), exp is an exponential function with the Napier's number e as the base, and log is the common logarithm. α 1 , β 1 , γ 1 , a 11 , b 11 , c 11 , a 12 , b 12 , c 12 , a 13 , b 13 , c 13 and d 1 are 0.0676, 0.6105, 0.3219, 2.9770, 0.2966, 1.4983, 3.1436, -4.5792, 0.7557, 0.7984, -4.2000, 0.9134 and 1.2789, respectively. )]]

4. r 1 The marine biodegradable polymer compound according to claim 3, wherein the amount is 10 to 90 mol%.

5. Of the two or more polyvalent carboxylic acid residues, at least one is an aliphatic carboxylic acid residue, and at least one is an aromatic carboxylic acid residue, and the sum of the proportions of each aliphatic carboxylic acid residue to the total number of aliphatic carboxylic acid residues and total aromatic carboxylic acid residues is r 2 Expressed as mol%, the number-average molecular weight is m 2 In this case, P is represented by the following equation (2). 2 The value is 0.245 to 0.805 (however, the proportion of aliphatic carboxylic acid residues with 4 or fewer carbon atoms is r 2 When adding it, multiply by 0.

250. ) The marine biodegradable polymer compound according to claim 1. [Math 5] [In the formula, f(r 2 ), g(m 2 ) and h(r 2 , m 2 These values ​​are represented by the following formulas (2-1), (2-2), and (2-3), respectively. [Math 6] [Number 7] [Number 8] (In equations (2-1) to (2-3), exp is the exponential function with base e (Napier's number), and log is the common logarithm. α 2 , β 2 gamma 2 a 21 , b 21 , c 21 a 22 , b 22 , c 22 a 23 , b 23 , c 23 and d 2 These are 0.2653, 0.4012, 0.3335, 7.9171, 0.6603, 2.227, 3.3353, -4.2489, 0.6774, 1.6621, -4.6736, 0.6076, and 0.8414, respectively.

6. r 2 The marine biodegradable polymer compound according to claim 5, wherein the amount is 30 to 95 mol%.

7. The marine biodegradable polymer compound according to claim 1, wherein the number average molecular weight is 500 to 50,000.

8. The marine biodegradable polymer compound according to claim 1, wherein the polyhydric alcohol residue is derived from a polyhydric alcohol having 2 to 20 carbon atoms.

9. The marine biodegradable polymer compound according to claim 3, wherein the aliphatic carboxylic acid residue is derived from a polycarboxylic acid having 2 to 20 carbon atoms.

10. The marine biodegradable polymer compound according to claim 5, wherein the aliphatic carboxylic acid residue is derived from a polycarboxylic acid having 2 to 20 carbon atoms.

11. The polymer compound according to claim 5, wherein the aromatic carboxylic acid residue is derived from an aromatic polycarboxylic acid having 6 to 20 carbon atoms.

12. A marine biodegradable polymer compound comprising two or more polyvalent carboxylic acid residues and one or more polyvalent alcohol residues, wherein polyester-type polyvalent anions having a total of two or more monovalent anionic substituents at their terminals are bonded via divalent or greater cations.

13. The marine biodegradable polymer compound according to claim 12, wherein the content of the divalent or greater cation is 1 to 100 eq / 105 g.

14. A marine biodegradable composition comprising a marine biodegradable polymer compound according to any one of claims 1 to 13.

15. A marine biodegradation accelerator comprising the marine biodegradable composition described in claim 14.

16. A molded article obtained from the marine biodegradable composition according to claim 14.

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