Crosslinked marine biodegradable polymer compound comprising different anionic polymer compounds, and method for producing same

Abstract

Provided is a marine biodegradable polymer compound which has a main chain that is linear or branched, which has a total of two or more monovalent anionic groups at terminals of the main chain, and in which are bonded, via a divalent or polyvalent metal cation, an anionic polymer compound A that has no ionic group in a side chain and an anionic polymer compound B that has a monovalent anionic group in a side chain of two or more repeating units.

Description

Crosslinked marine biodegradable polymer compound consisting of different anionic polymer compounds and method for producing the same

[0001] The present invention relates to a crosslinked marine biodegradable polymer compound comprising different anionic polymer compounds and a method for producing the same.

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

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

[0004] Although starch-based resins have been commercialized as biodegradable resins, most of them are mixed with polyester resins such as polybutylene adipate / terephthalate (PBAT) and polylactic acid (PLA), which are difficult to biodegrade in the ocean, because the physical properties of starch alone are significantly inferior. Therefore, even starch-based resins tend to have significantly reduced biodegradability in the ocean.

[0005] Under these circumstances, there is a need to develop materials that can be reliably decomposed in any type of seawater while maintaining their physical properties, as well as materials that can act as decomposition accelerators for resins that are difficult to biodegrade in seawater, while also reducing the environmental impact.

[0006] Hideshige Takada, "Current Status of Microplastic Pollution, International Trends and Countermeasures," Journal of the Japanese Society of Material Cycles and Waste Management, Vol. 29, No. 4, pp. 261-269, 2018; Akira Ebisui and four others, "Decomposition of Biodegradable Plastics in Seawater," Journal of Fisheries Engineering, Vol. 40, No. 2, pp. 143-149, 2003

[0007] The present invention has been made in view of the above circumstances, and aims to provide a polymer compound that has excellent thermal and mechanical properties and is biodegradable in the ocean, and a marine biodegradable resin composition using the same.

[0008] As a result of extensive research to solve the above-mentioned problems, the present inventors have found that a polymer compound in which an anionic polymer compound A having a linear or branched main chain, a total of two or more monovalent anionic groups at the ends of the main chain, and no ionic groups in the side chain, and an anionic polymer compound B having monovalent anionic groups in the side chains of two or more repeating units are bonded via a divalent or higher metal cation, has excellent thermal and mechanical properties and exhibits high marine biodegradability.

[0009] Furthermore, the inventors discovered that by using this material in combination with a resin, particularly a biodegradable resin, the material undergoes primary decomposition in seawater first, resulting in (1) the formation of pores in the resin material, which increases the specific surface area of ​​the resin and promotes the growth of microorganisms responsible for decomposition, and (2) the primary decomposition promotes secondary decomposition, i.e., biodegradation by microorganisms, thereby ultimately promoting the biodegradation of resin materials in the ocean, thereby completing the present invention.

[0010] That is, the present invention provides the following marine biodegradable polymer compounds and methods for producing the same. 1. A marine biodegradable polymer compound having a linear or branched main chain, a total of two or more monovalent anionic groups at the ends of the main chain, and comprising an anionic polymer compound A having no ionic groups in its side chain, and an anionic polymer compound B having monovalent anionic groups in the side chains of two or more repeating units, bonded via a divalent or higher metal cation. 2. The polymer compound of 1, in which the mass ratio of anionic polymer compound A to anionic polymer compound B is 99:1 to 10:90. 3. The polymer compound of 1 or 2, in which the main chain of anionic polymer compound A is linear. 4. Any of the polymer compounds of 1 to 3, in which anionic polymer compound B contains a repeating unit having no ionic group. 5. Any of the polymer compounds of 1 to 4, in which anionic polymer compound B has an aliphatic unsaturated carbon-carbon bond in its main chain. 6. 10. Any of the polymer compounds 1 to 5, wherein the monovalent anionic group of the anionic polymer compound A is a carboxylate anion. 11. Any of the polymer compounds 1 to 6, wherein the monovalent anionic group of the anionic polymer compound B is a carboxylate anion or a sulfonate anion. 12. Any of the polymer compounds 1 to 7, wherein the monovalent anionic group of the anionic polymer compound B is bonded to a ring. 13. Any of the polymer compounds 1 to 8, wherein the number average molecular weight of the anionic polymer compound A is 500 to 10,000 and the number average molecular weight of the anionic polymer compound B is 500 to 10,000. 14. Any of the polymer compounds 1 to 9, wherein the anionic polymer compound A is a polymer in which repeating units are bonded by at least one bond selected from an ester bond, an amide bond, an ether bond, and a urethane bond, and the anionic polymer compound B is a polymer in which repeating units are bonded by at least one bond selected from an ester bond, an amide bond, an ether bond, and a urethane bond. 15. Any of the polymer compounds 1 to 9, wherein the repeating units of the anionic polymer compound A are bonded by at least one bond selected from an ester bond, an amide bond, an ether bond, and a urethane bond. 11. A polymer compound according to any one of 1 to 10, wherein the value obtained by dividing the number average molecular weight of the anionic polymer compound B by the average number of monovalent anionic groups in one molecule is 100 to 5,000. 12. The content of the divalent or more polyvalent metal cation is 1 to 300 eq / 10 5g. 13. The polymer compound of any one of 1 to 12, wherein the divalent or higher metal cation is calcium ion, magnesium ion, or aluminum ion. 14. A marine biodegradation promoter comprising the marine biodegradable polymer compound of any one of 1 to 13. 15. A marine biodegradable resin composition comprising the marine biodegradation promoter of 14 and a resin. 16. The marine biodegradable resin composition of 15, wherein the resin is a biodegradable resin. 17. The marine biodegradable resin composition of 15 or 16, wherein the content of the marine biodegradation promoter is 1 to 50 mass % and the content of the resin is 50 to 99 mass %. 18. A molded article obtained from the marine biodegradable resin composition of any one of 15 to 17. 19. A method for producing a marine biodegradable polymer compound includes a step of crosslinking an anionic polymer compound A having a linear or branched main chain, a total of two or more monovalent anionic groups at the ends of the main chain, and no ionic groups in the side chains, and an anionic polymer compound B having monovalent anionic groups in the side chains of at least two repeating units, with a divalent or higher metal cation.

[0011] The marine biodegradable polymer compound of the present invention is a crosslinked compound, via a metal cation, of an anionic polymer compound having a monovalent anionic group at the terminal and an anionic polymer compound having a monovalent anionic group in a side chain of a repeating unit, and therefore exhibits both thermal and mechanical properties and marine biodegradability. Furthermore, the marine biodegradable polymer compound gradually dissolves in seawater upon contact with seawater or exhibits hydrophilicity, thereby promoting biodegradation in the ocean for resin compositions and molded articles containing the compound, making them useful for combating marine pollution. Because the marine biodegradable polymer compound has marine biodegradability, compositions and molded articles containing the compound also promoting biodegradation in the ocean for marine pollution. Environmentally friendly compositions and molded articles can be obtained by using a marine biodegradation promoter comprising the marine biodegradable polymer compound of the present invention.

[0012] [Marine biodegradable polymer compound] The marine biodegradable polymer compound of the present invention has a linear or branched main chain, has a total of two or more monovalent anionic groups at the terminals of the main chain, and is formed by bonding an anionic polymer compound A having no ionic groups in its side chain and an anionic polymer compound B having monovalent anionic groups in the side chains of two or more repeating units via a divalent or higher metal cation. In the present invention, the term "main chain" refers to the molecular chain that forms the skeleton of the polymer structure. The main chain may have a ring structure therein. The term "side chain" refers to a substituent bonded to the main chain.

[0013] In the marine biodegradable polymer compound of the present invention, the mass ratio of anionic polymer compound A to anionic polymer compound B is preferably A:B=99:1 to 10:90, more preferably 95:15 to 15:85, and even more preferably 90:10 to 20:80. When the mass ratio of anionic polymer compound A to anionic polymer compound B is within the above range, the flexibility derived from anionic polymer compound A and the thermal and mechanical properties derived from anionic polymer compound B can be compatible, and the polymer compound has good biodegradability.

[0014] The anionic polymer compound A may be linear or branched. From the viewpoint of the thermal and mechanical properties of the polymer compound after crosslinking, the anionic polymer compound A is preferably linear or branched and has a total of 2 to 10 monovalent anionic groups at the terminals of the main chain, more preferably has a total of 2 to 4 monovalent anionic groups at the terminals of the main chain, and even more preferably has a linear anionic polymer compound A and has a total of 2 monovalent anionic groups at the terminals of the main chain.

[0015] The anionic polymer compound B may contain a repeating unit having no ionic group in addition to the repeating unit having the monovalent anionic group, as long as two or more repeating units have a monovalent anionic group. In this case, the anionic polymer compound B is not particularly limited in the monomer arrangement, and may be any of a random copolymer, an alternating copolymer, a block copolymer, etc. Furthermore, the anionic polymer compound B may be linear or branched, but is preferably linear from the viewpoint of the thermal and mechanical properties of the polymer compound after crosslinking.

[0016] The anionic polymer compound B may also have aliphatic unsaturated carbon-carbon bonds in the main chain. In this case, the number of aliphatic unsaturated carbon-carbon bonds per molecule is preferably 0.1 to 50 on average, more preferably 0.5 to 25, and even more preferably 1 to 10, so as to achieve both strength and biodegradability.

[0017] From the viewpoints of physical properties and safety, the monovalent anionic group contained in the anionic polymer compound A is preferably a carboxylate anion, a sulfonate anion, or a phosphate anion, more preferably a carboxylate anion or a sulfonate anion, and even more preferably a carboxylate anion. The monovalent anionic groups contained in the anionic polymer compound A may be the same as or different from each other.

[0018] From the viewpoint of physical properties and safety, the monovalent anionic group contained in the anionic polymer compound B is preferably a carboxylate anion, a sulfonate anion, or a phosphate anion, more preferably a carboxylate anion or a sulfonate anion, and even more preferably a sulfonate anion. The monovalent anionic groups contained in the anionic polymer compound B may be the same as or different from each other.

[0019] The monovalent anionic group contained in the anionic polymer compound B may be bonded directly to the main chain or via a linking group. However, taking into consideration the thermal and mechanical properties, it is preferably bonded directly to the main chain or via a linking group having 1 to 25 atoms, and more preferably directly to the main chain. When the monovalent anionic group is bonded directly to the main chain, it is more preferable that the main chain contains a ring and the monovalent anionic group is bonded to the ring. The ring may be an alicyclic ring or an aromatic ring, but is preferably an aromatic ring. Furthermore, the ring may be composed only of carbon atoms or a heterocyclic ring containing other atoms, but is preferably composed only of carbon atoms. When the monovalent anionic group is bonded via a linking group, the structure of the linking group may be linear, branched, or cyclic, but is preferably linear or branched, and more preferably linear. The atoms constituting the linking group are not particularly limited, but are preferably carbon, oxygen, nitrogen, boron, sulfur, phosphorus, or silicon, and more preferably carbon, oxygen, nitrogen, or sulfur.

[0020] The molecular weight of the anionic polymer compound A is not particularly limited, but from the viewpoints of thermal and mechanical properties and biodegradability, the number average molecular weight is preferably 200 to 100,000, more preferably 300 to 50,000, and even more preferably 500 to 10,000.

[0021] The molecular weight of the anionic polymer compound B is not particularly limited, but from the viewpoints of thermal and mechanical properties and biodegradability, the number average molecular weight is preferably 200 to 100,000, more preferably 300 to 50,000, and even more preferably 500 to 10,000.

[0022] Furthermore, from the viewpoint of the thermal and mechanical properties of the polymer compound after crosslinking, the value obtained by dividing the number average molecular weight of the anionic polymer compound B by the average number of monovalent anionic groups per molecule is preferably from 100 to 5000, more preferably from 200 to 3000, and even more preferably from 300 to 1000. Furthermore, two or more monovalent anionic groups may be contained in one repeating unit, and one or more types of repeating units having a monovalent anionic group and repeating units not having a monovalent anionic group may be contained.

[0023] It is possible to further improve the thermal and mechanical properties by adjusting the combination of the anionic polymer compound A and the anionic polymer compound B. Specifically, the sum of the weighted average based on the mass ratio of the number average molecular weights of the anionic polymer compound A components contained in the marine biodegradable polymer compound and the weighted average based on the mass ratio of the number average molecular weights of the anionic polymer compound B components is preferably 500 to 50,000, more preferably 1,000 to 30,000, even more preferably 1,500 to 10,000, and most preferably 2,000 to 8,000.

[0024] In this case, the anionic polymer compound A and the anionic polymer compound B are preferably combined by combining an anionic polymer compound A having a number average molecular weight of 200 to 20,000 with an anionic polymer compound B having a number average molecular weight of 300 to 30,000, more preferably by combining an anionic polymer compound A having a number average molecular weight of 500 to 10,000 with an anionic polymer compound B having a number average molecular weight of 500 to 20,000, and even more preferably by combining an anionic polymer compound A having a number average molecular weight of 500 to 3,000 with an anionic polymer compound B having a number average molecular weight of 1,500 to 5,000.

[0025] From the viewpoints of thermal and mechanical properties and biodegradability, the anionic polymer compound A is preferably one in which repeating units are bonded by at least one bond selected from an ester bond, an amide bond, an ether bond, and a urethane bond, more preferably one in which repeating units are bonded by an ester bond or an amide bond, and even more preferably one in which repeating units are bonded by an ester bond. Furthermore, from the viewpoints of thermal and mechanical properties and biodegradability, the repeating units are preferably aliphatic or aromatic having 1 to 20 carbon atoms, or a combination thereof, more preferably aliphatic or aromatic having 1 to 10 carbon atoms, or a combination thereof, and even more preferably aliphatic having 1 to 10 carbon atoms.

[0026] From the viewpoints of thermal and mechanical properties and biodegradability, the anionic polymer compound B is preferably one in which repeating units are bonded by at least one bond selected from an ester bond, an amide bond, an ether bond, and a urethane bond, more preferably one in which repeating units are bonded by an ester bond or an amide bond, and even more preferably one in which repeating units are bonded by an ester bond. Furthermore, from the viewpoints of thermal and mechanical properties and biodegradability, the repeating units are preferably aliphatic or aromatic having 1 to 20 carbon atoms, or a combination thereof, more preferably aliphatic or aromatic having 1 to 10 carbon atoms, or a combination thereof, and even more preferably a combination of aliphatic and aromatic having 1 to 10 carbon atoms.

[0027] The anionic polymer compound A preferably has a relative cellulose biodegradability of 40% or more, more preferably 50% or more, even more preferably 60% or more, and most preferably 80% or more. In the present invention, the relative cellulose biodegradability refers to the maximum decomposition rate relative to the maximum cellulose decomposition rate within two years after immersion in seawater. The relative cellulose biodegradability can be measured using ASTM D6691, known marine biodegradation test methods, etc., or BODs modified with reference to these methods.

[0028] The anionic polymer compound B preferably has a relative cellulose biodegradability of 40% or more, more preferably 50% or more, even more preferably 60% or more, and most preferably 80% or more.

[0029] The anionic polymer compound A preferably has a softening point or melting point. The anionic polymer compound A is preferably solid or liquid at room temperature, and specifically, the lower limit of the softening point or melting point is preferably −80° C. or higher, −40° C. or higher, 0° C. or higher, 40° C. or higher, and 80° C. or higher, in that order, and the upper limit is preferably 180° C. or lower, 150° C. or lower, and 120° C. or lower, in that order. In consideration of handleability, the softening point or melting point is preferably within the range of −80 to 180° C., more preferably −40 to 120° C.

[0030] The anionic polymer compound B preferably has a softening point or melting point. The anionic polymer compound B is preferably a solid or liquid at room temperature, and specifically, the lower limit of the softening point or melting point is preferably 0°C or higher, 25°C or higher, 40°C or higher, 80°C or higher, and 100°C or higher, in that order, and the upper limit is preferably 180°C or lower, 150°C or lower, and 120°C or lower, in that order. In consideration of handleability, the softening point or melting point is preferably within the range of 0 to 180°C, more preferably 25 to 120°C.

[0031] The anionic polymer compound A is preferably dissolved in water or a water-miscible solvent, more specifically, in concentrations of 1 mass %, 5 mass %, 10 mass %, 20 mass %, 30 mass %, and 50 mass % or more in water or a water-miscible solvent, respectively. The water or water-miscible solvent may be cooled or heated.

[0032] The anionic polymer compound B is preferably dissolved in water or a water-miscible solvent, more specifically, in concentrations of 1 mass %, 5 mass %, 10 mass %, 20 mass %, 30 mass %, and 50 mass % or more in water or a water-miscible solvent, respectively. The water or water-miscible solvent may be cooled or heated.

[0033] Examples of the solvent miscible with water include lower alcohol solvents such as methanol, ethanol, 1-propanol, and 2-propanol, and amphipathic solvents such as acetone, acetonitrile, tetrahydrofuran (THF), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and N-methylpyrrolidone (NMP). From the viewpoints of miscibility with water, solubility, and ease of handling, ethanol, acetonitrile, THF, and NMP are preferred, and ethanol and acetonitrile are more preferred.

[0034] The method for producing the anionic polymer compound A is not particularly limited, but the anionic polymer compound A can be produced, for example, by introducing the monovalent anionic group via a linking group into a compound (hereinafter also referred to as polymer compound A) having a linear or branched main chain, having a total of two or more active functional groups such as hydroxy groups, amino groups, and thiol groups at the terminals of the main chain, and having no ionic groups in the side chains.

[0035] As the polymer compound A, commercially available products or synthesized products can be used. Examples of commercially available products include Kuraray Polyol P-1010, P-2010, P-2020, P-2050, P-520, C-590, and F-1010 (manufactured by Kuraray Co., Ltd.), Placcel 210B, 220N, and 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, and poly(propylene glycol) bis(2-aminopropyl ether) 2000 (manufactured by Sigma-Aldrich Japan LLC). When synthesizing the polymer compound A, two or more suitable raw materials are selected from, for example, divalent or higher carboxylic acids, divalent or higher alcohols, divalent or higher amines, and divalent or higher isocyanates, and the like, and the polymer can be obtained by polycondensation or polyaddition reaction. For example, polyester polyols can be obtained by polycondensation of divalent or higher carboxylic acids with divalent or higher alcohols, polyamide polyamines can be obtained by polycondensation of divalent or higher carboxylic acids with divalent or higher amines, and polyurethane polyols can be obtained by polyaddition of divalent or higher isocyanates with divalent or higher alcohols. However, these combinations are not limited to these. Three or more raw materials with different functional groups may be used, or two or more different raw materials with the same functional group may be used simultaneously. Furthermore, when using trivalent or higher raw materials, the total amount of the trivalent or higher raw materials is preferably 0.01 to 50 mol%, more preferably 0.05 to 30 mol%, and most preferably 0.1 to 15 mol% of the total amount of the raw materials. In this case, derivatives of the respective raw materials may be used in place of the raw materials to facilitate the reaction. Furthermore, in the above reaction, base catalysts such as diazabicycloundecene (DBU) and triethylamine, or metal catalysts such as dibutyltin dilaurate and titanium tetraisopropoxide may also be used.

[0036] Examples of the divalent or higher carboxylic acid include oxalic acid, malonic acid, fumaric acid, maleic acid, succinic acid, adipic acid, sebacic acid, 1,2,3-propanetricarboxylic acid, aconitic acid, malic acid, citric acid, phthalic acid, isophthalic acid, terephthalic acid, 1,3,5-benzenetricarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, trimellitic acid, and pyromellitic acid.

[0037] Examples of the dihydric or higher alcohol include ethylene glycol, glycerol, 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, 1,2,5-pentanetriol, 2-hydroxy-2-ethyl-1,3-propanol, pentaerythritol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 1,3,5-cyclohexanetriol, 1,6-hexanediol, 2,5-hexanediol, 3-methylpropanol, and the like. 1,5-pentanediol, 1,7-heptanediol, 1,4-benzenedimethanol, 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, pyrogallol, 1,2,4-benzenetriol, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, polyethylene glycol, and the like.

[0038] Examples of the divalent or higher amines 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-phenylenediamine, 1,2-diphenylethylenediamine, and orthotoliidine.

[0039] Examples of the divalent or higher isocyanate include hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), isophorone diisocyanate (IPDI), cyclohexane-1,4-diisocyanate, methylenebis(4-cyclohexylisocyanate), toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymeric MDI, xylene diisocyanate, and 1,4-phenylene diisocyanate.

[0040] The anionic polymer compound B can be a commercially available product or a synthesized product. An example of a commercially available product is Z-221 (GOO Chemical Industry Co., Ltd.). The anionic polymer compound B can be synthesized by a polymerization reaction using a monomer having a monovalent anionic group or a functional group that can be converted into an anionic group by appropriate treatment, or by a reaction between a polymer compound containing a repeating unit having a reactive site and a compound (hereinafter also referred to as compound b) that is reactive with the reactive site and has a monovalent anionic group or a functional group that can be converted into a monovalent anionic group by appropriate treatment.

[0041] Specific examples of the monomer include 5-sodium sulfoisophthalate, 4-sodium sulfoisophthalate, 4-sulfonaphthalene-2,6-dicarboxylic acid, monomethyl trimellitate, pyromellitic dianhydride, 4,4'-biphthalic anhydride, methacrylic acid, methyl methacrylate, and styrenesulfonic acid.

[0042] Polymerization reactions using the monomers include polycondensation and polyaddition reactions between the monomers and divalent or higher carboxylic acids, divalent or higher alcohols, divalent or higher amines, divalent or higher isocyanates, etc. Examples of the divalent or higher carboxylic acids, divalent or higher alcohols, divalent or higher amines, and divalent or higher isocyanates include those described above. Preferred examples of the polymerization reactions include polycondensation reactions with 5-sodium sulfoisophthalate, terephthalic acid, and 1,4-butanediol, and polyaddition reactions between pyromellitic dianhydride and hexamethylenediamine. In this case, derivatives of the respective raw materials may be used in place of the raw materials themselves to facilitate the reaction. Furthermore, base catalysts such as DBU and triethylamine, or metal catalysts such as dibutyltin dilaurate and titanium tetraisopropoxide may also be used in the reactions.

[0043] Examples of polymer compounds containing a repeating unit having a reactive site include unsaturated polymer compounds containing a repeating unit having an aliphatic unsaturated carbon-carbon bond, such as unsaturated polyester compounds, unsaturated polyamide compounds, and unsaturated polyurethane compounds. These unsaturated polymer compounds can be synthesized by using unsaturated polycarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, 2-pentenedioic acid, methylenesuccinic acid, allylmalonic acid, isopropylidenesuccinic acid, 2,4-hexadienedioic acid, and acetylenedicarboxylic acid, unsaturated polyhydric alcohols such as 2-butene-1,4-diol and 3-hexene-1,6-diol, unsaturated polyamines such as 2-butene-1,4-diamine and 3-hexene-1,6-diamine, and unsaturated polyisocyanates such as 2-butene-1,4-diisocyanate and 3-hexene-1,6-diisocyanate, together with the divalent or higher carboxylic acids, divalent or higher alcohols, divalent or higher amines, and divalent or higher isocyanates. Preferred examples include unsaturated polyesters obtained by polycondensation of maleic acid and 1,4-butanediol, and unsaturated polyamides obtained by polycondensation of sebacic acid, maleic acid, and hexamethylenediamine. In this case, derivatives of the respective raw materials may be used in place of the raw materials themselves in order to facilitate the reaction. Furthermore, in the reaction, a base catalyst such as DBU or triethylamine, or a metal catalyst such as dibutyltin dilaurate or titanium tetraisopropoxide may be used. In addition to the unsaturated polymer compounds, a polymer compound having a temporary radical site in the system may be produced by reacting a polyolefin polymer or a polyether polymer with a radical initiator or radiation.

[0044] Among compounds b, examples of compounds reactive with aliphatic unsaturated carbon-carbon bonds include nucleophilic organic acids and derivatives thereof, such as mercaptocarboxylic acids such as 3-mercaptopropionic acid, amino acids such as 5-aminovaleric acid and 6-aminohexanoic acid, aminosulfonic acids such as 2-aminoethanesulfonic acid, aminophosphoric acids such as ethanolamine phosphate, malonic acid, and organocopper ate complexes, when the reaction with the unsaturated bond is a conjugate addition reaction; carboxylic acids and sulfonic acids having an unsaturated bond such as acrylic acid, 3-pentenoic acid, carboxystyrene, and styrenesulfonic acid when the reaction with the unsaturated bond is a radical reaction; pyrrole carboxylic acids such as 1-methyl-2-pyrrolecarboxylic acid when the reaction with the unsaturated bond is a Diels-Alder reaction; and carboxylic acids having an unsaturated bond such as acrylic acid and 3-pentenoic acid when the reaction with the unsaturated bond is a photocycloaddition reaction. Among compounds b, examples of compounds reactive with radical sites include carboxylic acids and sulfonic acids having an unsaturated bond such as acrylic acid, 3-pentenoic acid, carboxystyrene, and styrenesulfonic acid.

[0045] The reaction between the polymer compound containing a repeating unit having a reactive site and compound b is not particularly limited. However, taking into consideration reactivity, selectivity, the physical properties of the product, and safety, it is preferable to use 3-mercaptopropionic acid, 5-aminovaleric acid, 6-aminohexanoic acid, or a malonic acid derivative in the conjugate addition reaction, and it is most preferable to use 3-mercaptopropionic acid in the conjugate addition reaction. In the reaction, a commonly used catalyst may be used as needed. Examples of such catalysts include base catalysts such as DBU and TEA in the conjugate addition reaction, transition metal catalysts such as organoruthenium complexes and organotitanium complexes in the radical reaction, Lewis acid catalysts such as ytterbium triflate and scandium triflate in the Diels-Alder reaction, and photosensitizers such as thiophene and benzophenone in the photocycloaddition reaction. In this case, derivatives of the respective raw materials may be used in place of the raw materials in order to facilitate the reaction.

[0046] [Marine Biodegradable Polymer Compound] The marine biodegradable polymer compound of the present invention is one in which an anionic polymer compound A and an anionic polymer compound B are bonded via a divalent or higher metal cation.

[0047] The divalent or higher metal cation is not particularly limited, but examples thereof include 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. Among these, calcium ions, beryllium ions, magnesium ions, strontium ions, barium ions, zinc ions, and aluminum ions are preferred, with calcium ions, magnesium ions, and aluminum ions being more preferred. The divalent or higher metal cations may be used alone or in combination.

[0048] The marine biodegradable polymer compound of the present invention may contain only one type of anionic polymer compound A and one type of anionic polymer compound B, or may contain multiple different types of anionic polymer compound B. The marine biodegradable polymer compound may also contain other anions, such as polyvalent anions, fatty acid anions, amino acid anions, amino acid derivative anions, and sulfonate anions.

[0049] Examples of the polyvalent anions include anions of 1,5-naphthalenedisulfonic acid, ethanedisulfonic acid, monoethyl phosphate, malic acid, aspartic acid, glutamic acid, succinic acid, adipic acid, sebacic acid, terephthalic acid, and isophthalic acid.

[0050] Examples of the fatty acid anions include anions of caproic acid, enanthic acid, caprylic acid, octylic acid, pelargonic acid, capric acid, undecylenic acid, lauric acid, myristic acid, pentadecylic acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, isostearic acid, oleic acid, vaccenic acid, ricinoleic acid, linoleic acid, linolenic acid, eleostearic acid, oxystearic acid, arachidic acid, mead 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.

[0051] Examples of the amino acid anion or amino acid derivative anion 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; sarcosine derivatives (caproyl sarcosine, lauroyl sarcosine, myristoyl sarcosine, palmitoyl sarcosine, 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, and dilauroyl glutamic acid); and glycine derivatives (lauroyl glycine, myristoyl glycine, palmitoyl glycine, palmitoyl methyl glycine, etc.). and anions of amino acid derivatives having a hydrocarbon group, such as lysine, coconut oil fatty acid acylglycine, cocoylglycine, etc.), alanine derivatives (laurylmethylalanine, myristoylmethylalanine, cocoylalanine, coconut oil fatty acid methylalanine, etc.), lysine derivatives (lauroyllysine, myristoyllysine, palmitoyllysine, stearoyllysine, oleyllysine, acylated lysine, etc.), aspartic acid derivatives (lauroylaspartic acid, myristoylaspartic acid, palmitoylaspartic acid, stearoylaspartic acid, etc.), taurine derivatives (lauroyltaurine, lauroylmethyltaurine, myristoyltaurine, myristoylmethyltaurine, palmitoyltaurine, palmitoylmethyltaurine, stearoyltaurine, stearoylmethyltaurine, etc.), and proline derivatives (lauroylproline, myristoylproline, palmitoylproline, etc.).

[0052] Examples of the sulfonate anion include anions of alkyl sulfonic acids (lauryl sulfonic acid, myristyl sulfonic acid, cetyl sulfonic acid, stearyl sulfonic acid, oleyl sulfonic acid, etc.), dodecyl benzene 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 sulfosuccinic acid (dihexyl sulfosuccinic acid, dioctyl sulfosuccinic acid, didecyl sulfosuccinic acid, diisobutyl sulfosuccinic acid, etc.).

[0053] The metal ion equivalent (content of divalent or higher metal cations) in the marine biodegradable polymer compound is 1 to 300 eq / 10 5 g is preferable, but considering biodegradability in seawater and mechanical properties, 10 to 200 eq / 10 5 g is more preferable, and 20 to 100 eq / 10 5 It is more preferable that the metal ion equivalent is in the above range, since the biodegradability is good and the mechanical properties are not impaired. The metal ion equivalent is a value measured by inductively coupled plasma mass spectrometry (ICP-MS).

[0054] The marine biodegradable polymer compound can be an amorphous or crystalline polymer compound depending on the blending ratio of the anionic polymer compound A and the anionic polymer compound B. The marine biodegradable polymer compound is solid at room temperature, and specifically, the lower limit of the softening point is preferably 0°C or higher, 40°C or higher, and 80°C or higher, in that order, and the upper limit is preferably 250°C or lower, 200°C or lower, 180°C or lower, and 160°C or lower, in that order. It is preferable that the softening point is within the range of preferably 40 to 200°C, more preferably 60 to 180°C, and even more preferably 80 to 160°C.

[0055] The marine biodegradable polymer compound preferably has a relative cellulose biodegradability of 40% or more, more preferably 50% or more, even more preferably 60% or more, and most preferably 80% or more.

[0056] [Method for producing marine biodegradable polymer compound] The marine biodegradable polymer compound can be produced by a method including a step of crosslinking anionic polymer compound A and anionic polymer compound B using a divalent or higher metal salt (hereinafter also referred to as a polyvalent metal salt).

[0057] Examples of the crosslinking treatment method include a method in which a powder, solution, or dispersion of a polyvalent metal salt is dropped into a solution or dispersion containing an anionic polymer compound A and an anionic polymer compound B, and precipitation or precipitating occurs while performing a bonding treatment; a method in which a powder, solution, or dispersion of a polyvalent metal salt is dropped into a melt of anionic polymer compound A and anionic polymer compound B, and precipitation or precipitating occurs while performing a bonding treatment; and a method in which a solution or dispersion containing anionic polymer compound A and anionic polymer compound B is dropped into a powder of a polyvalent metal salt or a solution or dispersion in which the polyvalent metal salt is dissolved, and precipitation or precipitating occurs while performing a bonding treatment. These methods may be performed alone or in combination.

[0058] In a preferred example, first, a solution in which anionic polymer compound A and anionic polymer compound B are dissolved in water, an organic solvent, or a mixed solvent thereof, or a melt in which anionic polymer compound A and anionic polymer compound B are heated to dissolve them, is prepared. At this time, heating may be performed as necessary to improve solubility or reduce the viscosity of the melt. Next, a solution containing a polyvalent metal salt is added to the obtained solution or melt and stirred. Alternatively, a solution or melt in which anionic polymer compound A and anionic polymer compound B are dissolved may be added to a solution containing a polyvalent metal salt and stirred.

[0059] Examples of the polyvalent metal salt include calcium salt, strontium salt, magnesium salt, barium salt, radium salt, lead salt, zinc salt, nickel salt, iron salt, copper salt, cadmium salt, cobalt salt, manganese salt, aluminum salt, gallium salt, indium salt, and thallium salt. However, calcium salt, magnesium salt, and aluminum salt are preferred from the viewpoints of being metals contained in seawater, environmental aspects, safety, and versatility, and calcium salt and magnesium salt are more preferred in consideration of the seawater environment. Specific examples of the polyvalent metal salt include 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), and potassium aluminum sulfate (potassium alum). However, calcium chloride, magnesium chloride, and aluminum sulfate are preferred from the viewpoints of water solubility, handling, cost, and the like.

[0060] The concentration of the polyvalent metal salt in the solution containing the polyvalent metal salt is preferably 1 to 40% by mass, more preferably 10 to 30% by mass. The solvent for the solution is preferably water, a lower alcohol solvent such as methanol, ethanol, 1-propanol, or 2-propanol, an amphipathic solvent such as acetone, acetonitrile, THF, DMF, DMSO, or NMP, or a mixed solvent thereof. However, a mixed solvent with other organic solvents may also be used as long as the salt can be dissolved to the desired concentration without dissolving the resin.

[0061] Furthermore, if the polyvalent metal salt has a good reactivity and is reactive even in a solid state, it may be used in a powder form without using a medium, or may be dispersed in a small amount of medium.

[0062] During crosslinking, for the purpose of controlling the particle size and shape (e.g., spherical shape) of the precipitate or sediment, a surfactant or a polymer stabilizer may be dissolved in at least one of the solution in which the anionic polymer compounds A and B are dissolved and the solution containing the polyvalent metal salt.

[0063] The method for preparing a solution or dispersion containing anionic polymer compound A and anionic polymer compound B is not limited, but examples include a method of mixing a monovalent salt of anionic polymer compound A and a monovalent salt of anionic polymer compound B with water or an organic solvent, or a method of mixing an acidic polymer compound A and an acidic polymer compound B in which the monovalent anionic group of anionic polymer compound A and the monovalent anionic group of anionic polymer compound B are bonded to protons with water or an organic solvent, and then adding a monovalent base thereto. These methods may be carried out alone or in combination. Furthermore, when carried out in combination, the order is not particularly limited.

[0064] The monovalent counter cation constituting the monovalent salt of anionic polymer compound A and the monovalent salt of anionic polymer compound B is preferably a lithium ion, a sodium ion, a potassium ion, a rubidium ion, a cesium ion, a francium ion, an ammonium ion, a methylammonium ion, an ethylammonium ion, an anilinium ion, a pyridinium ion, a dimethylammonium ion, a diethylammonium ion, a trimethylammonium ion, a triethylammonium ion, or the like. From the viewpoints of safety, environmental load, and operability, sodium ions, potassium ions, and ammonium ions are more preferred, and sodium ions and potassium ions are even more preferred.

[0065] Examples of the monovalent base include lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogencarbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, trisodium phosphate, tripotassium phosphate, lithium methoxide, sodium methoxide, potassium methoxide, lithium tert-butoxide, sodium tert-butoxide, potassium tert-butoxide, ammonia, methylamine, ethylamine, TEA, DBU, etc. Preferred are lithium hydroxide, sodium hydroxide, potassium hydroxide, lithium carbonate, sodium carbonate, potassium carbonate, lithium hydrogencarbonate, sodium hydrogencarbonate, and potassium hydrogencarbonate, and in consideration of safety and environmental impact, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, and potassium hydrogencarbonate are particularly preferred.

[0066] By adding a base containing a divalent or higher metal to water or an organic solvent containing an acidic polymer compound A and an acidic polymer compound B, it is possible to produce a marine biodegradable polymer compound in a chain reaction following the production of anionic polymer compound A and anionic polymer compound B.

[0067] Examples of the base containing a divalent or higher metal include 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 hydrogencarbonate, strontium hydrogencarbonate, calcium hydrogencarbonate, and barium hydrogencarbonate. From the viewpoints of solubility in water, reactivity, cost, and the like, calcium hydride, calcium methoxide, calcium hydroxide, and barium hydroxide are preferred, and calcium hydroxide is more preferred.

[0068] In a preferred example, a solution in which the acidic polymer compound A and the acidic polymer compound B are dissolved in water, an organic solvent, or a mixed solvent thereof, or a melt in which the acidic polymer compound A and the acidic polymer compound B are heated and dissolved, is prepared. At this time, heating may be performed as necessary to improve solubility or to reduce the viscosity of the melt. Next, a solution of a base containing a divalent or higher metal is added to the obtained solution or melt and stirred. Alternatively, a solution or melt in which the acidic polymer compound A and the acidic polymer compound B are dissolved may be added to a solution of a base containing a divalent or higher metal and stirred.

[0069] Examples of the base containing a divalent or higher metal include 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 hydrogencarbonate, strontium hydrogencarbonate, calcium hydrogencarbonate, and barium hydrogencarbonate. From the viewpoints of solubility in water, reactivity, cost, and the like, calcium hydride, calcium methoxide, calcium hydroxide, and barium hydroxide are preferred, and calcium hydroxide is more preferred.

[0070] Furthermore, the anionic polymer compound A and the anionic polymer compound B do not necessarily have to be crosslinked at the same time. For example, a marine biodegradable polymer compound can be obtained by crosslinking a portion of one of the anionic polymer compounds, then adding the other anionic polymer compound and further crosslinking the resulting mixture.

[0071] By subjecting anionic polymer compound A and anionic polymer compound B to the crosslinking treatment, anionic polymer compound A and anionic polymer compound B can be bonded via metal cations, and the target marine biodegradable polymer compound that gradually becomes insoluble can be obtained as a precipitate, sediment, or bulk. The treatment time is preferably 0.5 to 24 hours, and more preferably 1 to 12 hours.

[0072] Heating may be performed when precipitating or precipitating the desired marine biodegradable polymer compound. Heating may be performed when mixing a solution containing anionic polymer compound A and anionic polymer compound B or a melt of anionic polymer compound A and anionic polymer compound B with a solution containing a polyvalent metal salt, or when stirring after mixing, or both. Alternatively, heating may be performed when mixing a solution containing acidic polymer compound A and acidic polymer compound B or a melt of acidic polymer compound A and acidic polymer compound B with a solution containing a base containing a divalent or higher metal, or when stirring after mixing, or both. The heating temperature is preferably 5 to 200°C, more preferably 10 to 150°C, and even more preferably 20 to 100°C.

[0073] After the treatment, the particles can be washed and dried as needed to obtain a marine biodegradable polymer compound. Washing can be carried out by a conventional method, for example, removing the solvent after the binding treatment, adding water, and then centrifuging. Drying can be carried out by a conventional method, for example, spray drying, vacuum drying, freeze drying, etc. The obtained marine biodegradable polymer compound may be surface-treated or pulverized to adjust the particle size using known equipment as needed.

[0074] The marine biodegradable polymer compound may be one in which at least one of the monovalent anionic groups that is not bonded to other anionic polymer compounds via a divalent metal cation is blocked with a blocking segment group.

[0075] By selecting the capping segment group, it is possible to incorporate multiple effects in a single material and a composite material (marine biodegradable resin composition) using this material, such as adjustment of melting 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 resin, adjustment of hydrophobicity, adjustment of water repellency, adjustment of adhesion, and adjustment of plasticity, thereby improving both the biodegradability and physical properties of the marine biodegradable resin composition. Since the organic anion that forms the capping segment is desirably a structure that is biodegradable in the marine environment, it is desirable to select a capping segment group that is marine biodegradable and has a molecular weight of 5,000 or less. For example, when emphasis is placed on the rate of biodegradation in the marine environment and the maintenance of average physical properties, a molecular weight of 2,500 or less is preferred, and a molecular weight of 1,000 or less is more preferred.

[0076] Specifically, the blocking segment group preferably has a hydrocarbon group having 3 or more carbon atoms, more preferably has a hydrocarbon group having 6 or more carbon atoms, even more preferably has a hydrocarbon group having 10 or more carbon atoms, and most preferably has a hydrocarbon group having 12 or more carbon atoms. There are no particular limitations on the upper limit of the number of carbon atoms in the hydrocarbon group, but it is preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less.

[0077] The capping segment group is preferably an organic anion selected from a carboxylate anion having a hydrocarbon group with 3 or more carbon atoms, a sulfonate anion having a hydrocarbon group with 3 or more carbon atoms, a sulfate ester anion having a hydrocarbon group with 3 or more carbon atoms, and a phosphate ester anion having a hydrocarbon group with 3 or more carbon atoms. Of these, a monovalent organic anion derived from a carboxylic acid having a hydrocarbon group with 3 or more carbon atoms is preferred, and a monovalent organic anion derived from a fatty acid having a hydrocarbon group with 3 or more carbon atoms or an amino acid derivative having a hydrocarbon group with 3 or more carbon atoms is more preferred.

[0078] Terminal blocking can be carried out using at least one terminal blocking agent selected from a carboxylic acid having a hydrocarbon group of 3 or more carbon atoms, a salt of the carboxylic acid, a sulfonic acid having a hydrocarbon group of 3 or more carbon atoms, a salt of the sulfonic acid, a sulfate ester having a hydrocarbon group of 3 or more carbon atoms, a salt of the sulfate ester, a phosphate ester having a hydrocarbon group of 3 or more carbon atoms, and a salt of the phosphate ester. Terminal blocking can be carried out by adding the terminal blocking agent to a solution containing polymer compound A or B, followed by bonding treatment with a polyvalent metal ion.

[0079] As the terminal blocking agent, the acid compounds or salt compounds described in paragraphs

[0029] to

[0044] of JP-A-2021-191810 are preferred.

[0080] [Marine Biodegradable Resin Composition] The marine biodegradable resin composition of the present invention contains the marine biodegradable polymer compound.

[0081] The marine biodegradable polymer compound may be used as a main raw material, or may be used in combination with other resins as additives. The other resins are not particularly limited, but are preferably biodegradable resins. When used in combination with other resins as additives, the marine biodegradable polymer compound functions as a marine biodegradation promoter. In this case, the composite resin becomes a resin composition in which biodegradation in the ocean is promoted. Furthermore, in order to adjust the physical properties and handleability of the resin composition, multiple types of resins may be used in combination as the other resins.

[0082] Examples of the 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, bio-PET, bio-polyamide, bio-polycarbonate, bio-polyurethane, polyvinyl alcohol, polybutylene adipate / terephthalate, polyethylene terephthalate succinate, bio-polybutylene succinate, polylactic acid blend, starch-blend polyester resin, polybutylene terephthalate succinate, polylactic acid, and polyhydroxyalkanoic acid. However, in consideration of reducing the burden on the environment and promoting marine biodegradability, highly biodegradable resins are particularly preferred.

[0083] Further, examples of the biodegradable resin include resins whose raw materials are derived from petroleum, such as 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, and glycolic acid / trimethylene carbonate copolymer; (polylactic acid / polybutylene succinate-based) block copolymer, (polylactic acid / polycaprolactone) copolymer, and (polylactic acid / polyether) copolymer. Resins partially derived from biomass, such as polylactic acid blend PBAT, lactic acid / glycolic acid copolymer, biopolybutylene succinate, poly(butylene succinate / adipate), starch blend polyester resin, and poly(butylene terephthalate succinate); resins 100% derived from biomass, such as polyhydroxyalkanoates (e.g., polyhydroxyalkanoates) and polylactic acid (PLA), including polyhydroxybutyrate, polyhydroxyvalerate, polyhydroxycaprylic acid, poly(hydroxybutyrate / hydroxyhexanoate) (PHBH), poly(3-hydroxybutyrate / 4-hydroxybutyrate) (P3HB4HB), and poly(hydroxybutyrate / hydroxyvalerate) (PHBV); and resins derived from natural polymers, such as cellulose, cellulose acetate, cellulose ester resin, starch, esterified starch, and chitosan. These may be used alone or in combination of two or more.

[0084] Among these, it is preferable to combine the marine biodegradable polymer compound with a biodegradable resin selected from resins that are biodegradable in soil or compost but poorly biodegradable in the ocean, such as polycaprolactone, PBS, PBSA, PBAT, poly(tetramethylene adipate / terephthalate), poly(butylene succinate / carbonate), polyhydroxyalkanoates such as PHBH and PHBV, PLA, cellulose, starch, chitosan, etc. As the biodegradable resin, resins derived from PBSA, PBS, PBAT, PLA, and starch are particularly preferred.

[0085] Furthermore, in consideration of reducing the environmental load, 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 raw materials.

[0086] The marine biodegradable resin 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 may dissolve both the resin and the marine biodegradable polymer compound. By adjusting the solvent appropriately, the composition can be used as a molded body formed into a film by casting or the like, 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, ethylene dichloride, tetrachloroethane, chlorobenzene, methanol, ethanol, n-propanol, isopropanol, butanol, pentanol, hexafluoroisopropanol, methyl glycol, methyl triglycol, hexyl glycol, phenyl glycol, ethylene glycol, propylene glycol, phenol, cresol, polyethylene glycol, benzene, toluene, xylene, etc. These may be used alone or in combination of two or more.

[0087] When a solvent is used, the total concentration of the resin and the marine biodegradable polymer compound in the resin composition is preferably 0.5 to 90% by mass, more preferably 1 to 80% by mass, even more preferably 5 to 60% by mass, and most preferably 10 to 50% by mass. The ratio of the marine biodegradable polymer compound to the resin is preferably 99:1 to 10:90 by mass, more preferably 97:3 to 40:60, even more preferably 95:5 to 50:50, and most preferably 90:10 to 60:40.

[0088] The lower limit of the softening point of the resin composition is preferably 60° C. or higher, 70° C. or higher, and 80° C. or higher, in that order, and the upper limit is preferably 300° C. or lower, 250° C. or lower, 200° C. or lower, and 180° C. or lower, in that order. The softening point is preferably in the range of 60 to 250° C., more preferably 70 to 200° C., and even more preferably 80 to 180° C.

[0089] The marine biodegradable resin composition of the present invention may not contain a solvent. In this case, the resin may be thermally melted and then an insoluble marine biodegradable polymer compound may be added and mixed thereto, or the resin and the marine biodegradable polymer compound may be melted and mixed together.

[0090] In the marine biodegradable resin 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, even more preferably 7 to 40% by mass, and most preferably 10 to 35% by mass. Meanwhile, the content of the resin is preferably 40 to 99% by mass, more preferably 50 to 97% by mass, even more preferably 55 to 95% by mass, even more preferably 60 to 93% by mass, and most preferably 65 to 90% by mass. By including the marine biodegradable polymer compound in the above range, the composition can be utilized as a marine biodegradation promoter 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.

[0091] The tensile strength of a test piece obtained from the resin composition is preferably 80% or more, more preferably 85% or more, and even more preferably 90% or more when the content of the marine biodegradable polymer compound in the resin composition is 10% by mass, compared to a blank resin test piece not containing the marine biodegradable polymer compound of the present invention. Furthermore, when the content of the marine biodegradable polymer compound in the resin 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.

[0092] The marine biodegradable resin composition of the present invention may contain additives, as needed, such as antioxidants, release agents, peeling agents, surface modifiers, hydrophobizing agents, water repellent agents, hydrophilizing agents, dyes / pigments, colorants, heat stabilizers, light stabilizers, weather resistance improvers, antistatic agents, antifogging agents, lubricants, antiblocking agents, hardeners, softeners, compatibilizers, flame retardants, flow improvers, plasticizers, dispersants, antibacterial agents, fillers, metal deactivators, etc. 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 the resin.

[0093] When the marine biodegradable resin composition contains a solvent, it can be prepared, for example, by adding the resin, the marine biodegradable polymer compound, and, if necessary, the additives to a solvent simultaneously or in any order and mixing them. When the marine biodegradable resin composition does not contain a solvent, for example, the resin can be melted, and the marine biodegradable polymer compound and, if necessary, the additives can be added thereto simultaneously or in any order and mixed, or the resin and marine biodegradable polymer compound can be heated to melt and mix them together, and the additives can be added and mixed as necessary.

[0094] [Molded Article] By molding the resin composition, a molded article can be obtained in which the marine biodegradable polymer compound is dispersed or dissolved in the resin. When the resin composition contains a solvent, the resin composition can be used as is for molding. When the resin composition does not contain a solvent, the resin in the resin composition, or the resin and the marine biodegradable polymer compound, can be melted by heat and then molded.

[0095] The shape of the molded product may be, for example, a film, a fiber, a plate, a foam molded product, or any other shape depending on the intended use. The molding method is not particularly limited, and various conventionally known molding methods can be used. Specific examples thereof include blow molding, injection molding, extrusion molding, compression molding, melt extrusion molding, solution casting molding, and calendar molding.

[0096] [Uses] The marine biodegradable polymer compound and marine biodegradable resin composition of the present invention can be used as raw materials for plastic molded products, and as various additives for molded products such as liquids, coatings, films, plates, paper, etc. 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, laminated materials, adhesives, coating materials, medical materials, fibers for clothing, shoes, belts, tires, tubes, shock absorbers, fishing lines, fishing nets, etc., and for marine applications, etc., and are particularly suitable for use as raw materials for marine applications, etc. In addition, when used as an additive, for example, light scattering agents and optical filter materials, colorants, cosmetics, absorbents, adsorbents, inks, adhesives, electromagnetic wave shielding materials, fluorescent sensors, biomarkers, recording materials, recording elements, polarizing materials, drug carriers for drug delivery systems (DDS), biosensors, DNA chips, test agents, baked voided moldings, antiblocking agents, screen printing, offset printing, process printing, gravure printing, pad printing, coater, inkjet and the like additives for printing inks used, for marking pens, ballpoint pens, fountain pens, brush pens, markers and other writing instrument ink additives, crayons, paints, erasers and other stationery additives, brush coating, spray coating, electrostatic coating, electrodeposition coating, flow coating, roller coating, dip coating and the like additives for paints used in marine applications, particularly hull paints and the like It can be widely used as an additive.

[0097] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples and comparative examples, the metal ion equivalent was measured by heating and decomposing the target substance with nitric acid or aqua regia, and then by optical emission spectrometry using an ICP-MS (ICPE-9820, manufactured by Shimadzu Corporation). The number average molecular weight and the number of anionic groups were measured using a nuclear magnetic resonance spectrometer (JNM-ECZ400S, manufactured by JEOL Ltd.). 1 It was calculated from the integrated value of the peak in H-NMR.

[0098] [1] Synthesis of Anionic Polymer Compound A [Synthesis Example 1-1] Synthesis of Anionic Polymer Compound A-1 400 g of polyester diol (Kuraray Polyol P-1010 manufactured by Kuraray Co., Ltd.), 84 g of succinic anhydride, and 40 g of acetonitrile were charged into a 1000 mL reaction vessel and stirred at 130°C for 2 hours under a nitrogen atmosphere to obtain an acidic polymer compound A-1. 500 g of acidic polymer compound A-1, 412 g of water, and 88 g of potassium bicarbonate were added to a 3000 mL recovery flask and stirred at room temperature to obtain an anionic polymer compound A-1. The aniline polymer compound A-1 is linear and has monovalent anionic groups at both ends thereof, 1 The number average molecular weight was confirmed to be 1,300 by H-NMR measurement.

[0099] Synthesis Example 1-2 Synthesis of Anionic Polymer Compound A-2 400 g of polyester triol (Kuraray Polyol F-1010 manufactured by Kuraray Co., Ltd.), 126 g of succinic anhydride, and 60 g of acetonitrile were charged into a 1000 mL reaction vessel and stirred at 130°C for 2 hours under a nitrogen atmosphere to obtain an acidic polymer compound A-2. 500 g of acidic polymer compound A-2, 368 g of water, and 132 g of potassium bicarbonate were added to a 3000 mL recovery flask and stirred at room temperature to obtain an anionic polymer compound A-2. The aniline polymer compound A-2 is a branched polymer branched into three branches, and has monovalent anionic groups at all of its terminals. 1 The number average molecular weight was confirmed to be 1,400 by H-NMR measurement.

[0100] Synthesis Example 1-3 Synthesis of Anionic Polymer Compound A-3 130 g of 1,4-butanediol, 71 g of dimethyl terephthalate, 150 g of dimethyl adipate, and 2.4 g of titanium tetraisopropoxide were added to a 1000 mL recovery flask and stirred at 160°C for 6 hours under a nitrogen atmosphere, followed by addition of 32 g of succinic anhydride and 40 g of acetonitrile and stirring at 130°C for 2 hours to obtain acidic polymer compound A-3. 350 g of acidic polymer compound A-3, 316 g of water, and 34 g of potassium bicarbonate were added to a 3000 mL recovery flask and stirred at 80°C to obtain anionic polymer compound A-3. The aniline polymer compound A-3 is linear and has monovalent anionic groups at both ends. 1 The number average molecular weight was confirmed to be 2,300 by H-NMR measurement.

[0101] Synthesis Example 1-4 Synthesis of Anionic Polymer Compound A-4 280 g of hexamethylenediamine, 340 g of sebacic acid, and 80 g of water were added to a 1000 mL recovery flask, and the flask was placed in an autoclave and thoroughly purged with nitrogen. The temperature was then raised to 230°C with stirring. While maintaining a sealed state, the flask was stirred at 230°C for 1 hour, after which the pressure was released to normal pressure. The solids were washed with ethanol and dried. 400 g of the dried resin was pulverized, and 82 g of succinic anhydride, 100 g of potassium carbonate, and 400 g of acetonitrile were added. After stirring at 70°C for 4 hours, the reaction solution was cooled to room temperature, allowing a precipitate to precipitate. The precipitate was removed by filtration, and the resulting filtrate was concentrated under reduced pressure to obtain an acidic polymer compound A-4. Finally, 300 g of acidic polymer compound A-4, 263 g of water, and 37 g of potassium bicarbonate were added to a 3000 mL recovery flask and stirred at 80°C to obtain an anionic polymer compound A-4. The aniline polymer compound A-4 is linear and has monovalent anionic groups at both ends thereof. 1 The number average molecular weight was confirmed to be 1,800 by H-NMR measurement.

[0102] Synthesis Example 1-5 Synthesis of Anionic Polymer Compound A-5 300 g of polyether diol (polytetramethylene ether glycol manufactured by Mitsubishi Chemical Corporation), 94 g of succinic anhydride, and 30 g of acetonitrile were charged into a 1000 mL reaction vessel and stirred at 130°C for 2 hours under a nitrogen atmosphere to obtain an acidic polymer compound A-5. 400 g of acidic polymer compound A-5, 1100 g of water, and 100 g of potassium bicarbonate were added to a 3000 mL recovery flask and stirred at room temperature to obtain an anionic polymer compound A-5. The aniline polymer compound A-5 is linear and has monovalent anionic groups at both ends. 1 The number average molecular weight was confirmed to be 900 by H-NMR measurement.

[0103] The anionic polymer compounds A-1 to A-5 are listed in Table 1 below.

[0104]

[0105] [2] Synthesis of anionic polymer compound B

[0106] Synthesis Example 2-1 Synthesis of Anionic Polymer Compound B-1 204 g of ethylene glycol, 80 g of dimethyl terephthalate, 122 g of dimethyl sodium 5-sulfoisophthalate, and 1.0 g of titanium tetraisopropoxide were added to a 1000 mL recovery flask, and the mixture was stirred at 200°C for 3 hours under a nitrogen atmosphere, and the liquid was then distilled off under reduced pressure to obtain anionic polymer compound B-1. 1 It was confirmed by H-NMR measurement that the number average molecular weight was 3,000 and that the polymer had an average of six monovalent anionic groups in the side chains.

[0107] Synthesis Example 2-2 Synthesis of Anionic Polymer Compound B-2 142 g of ethylene glycol, 110 g of dimethyl sebacate, 142 g of dimethyl sodium 5-sulfoisophthalate, and 0.7 g of titanium tetraisopropoxide were added to a 1000 mL recovery flask and stirred at 200°C for 3 hours under a nitrogen atmosphere to obtain anionic polymer compound B-2. 1It was confirmed by H-NMR measurement that the number average molecular weight was 1500 and that the polymer had an average of three monovalent anionic groups in the side chain.

[0108] Synthesis Example 2-3 Synthesis of Anionic Polymer Compound B-3 195 g of 1,4-butanediol, 110 g of dimethyl adipate, 80 g of sodium dimethyl 5-sulfoisophthalate, and 0.9 g of titanium tetraisopropoxide were added to a 1000 mL recovery flask and stirred at 200°C for 3 hours under a nitrogen atmosphere to obtain anionic polymer compound B-3. 1 It was confirmed by H-NMR measurement that the number average molecular weight was 1900 and that the polymer had an average of three monovalent anionic groups in the side chain.

[0109] Synthesis Example 2-4 Synthesis of Anionic Polymer Compound B-4 After 11 g of hexamethylenediamine and 160 g of tetrahydrofuran were added to a 1000 mL recovery flask, a solution containing 25 g of pyromellitic anhydride and 200 g of tetrahydrofuran was gradually added, and the mixture was stirred at 50°C for 2 hours under a nitrogen atmosphere. After the solvent was distilled off, 22 g of potassium bicarbonate and 200 g of water were added, and the mixture was stirred at room temperature to obtain anionic polymer compound B-4. Anionic polymer compound B-4 was 1 H-NMR measurement confirmed that the number average molecular weight was 2000 and that the polymer had an average of 13 monovalent anionic groups on the side chains.

[0110] Synthesis Example 2-5 Synthesis of Anionic Polymer Compound B-5 119.1 g of 1,4-butanediol, 75.6 g of succinic acid, and 25.0 g of maleic acid were added to a 1000 mL recovery flask and stirred at 160°C for 6 hours under a nitrogen atmosphere, and then 90.1 g of 3-mercaptopropionic acid and 34.4 g of acetonitrile were added and stirred at 130°C for 4 hours to obtain anionic polymer compound B-5. 1 It was confirmed by H-NMR measurement that the number average molecular weight was 1800 and that the copolymer had an average of three monovalent anionic groups.

[0111] The anionic polymer compounds B-1 to B-5 are listed in Table 2 below.

[0112]

[0113] [3] Biodegradability Test of Anionic Polymer Compounds [Reference Examples 1 to 10] Anionic polymer compounds A-1 to A-5 and anionic polymer compounds B-1 to B-5 were subjected to a seawater biodegradation test using the following method. Microcrystalline cellulose (Sigma-Aldrich Avicel PH-101) was used as a control material, and the relative biodegradability of cellulose was evaluated. The results are shown in Table 4.

[0114] <Test method and conditions> Biodegradability measurement method: Measurement of oxygen consumption using a closed respirometer (see ASTM D6691) Test equipment: OxiTop IDS (manufactured by WTW) Incubation temperature: 30±1°C, dark place Biodegradability (%) = (BOD O -BOD B ) / ThOD×100 BOD O : Biochemical oxygen demand (measured value: mg) for testing or inoculum activity confirmation B : Average biochemical oxygen demand of blank test (measured value: mg) ThOD: Theoretical oxygen demand required when test material or control material is completely oxidized (calculated value: mg) Relative cellulose biodegradability (%) = (Maximum biodegradability of test particles / Maximum cellulose biodegradability) x 100 Seawater (collected from Tokyo Bay [Chiba Prefecture: Chiba Port])] The collected seawater was aerated at room temperature of 25°C after removing foreign matter with a 10 μm filter. In addition, ammonium chloride and potassium dihydrogen phosphate were added as inorganic nutrients to the solution at 0.05 g / L and 0.1 g / L, respectively.

[0115]

[0116] The results shown in Table 3 indicate that anionic polymer compound A and anionic polymer compound B were biodegradable, with the relative degree of cellulose decomposition reaching 40% or more within 60 days of the culture period.

[0117] [4] Synthesis of Marine Biodegradable Polymer Compounds [Example 1-1] Synthesis of Marine Biodegradable Polymer Compound C-1 400 g of a 25% by mass aqueous solution of anionic polymer compound A-1 and 100 g of a 25% by mass aqueous solution of anionic polymer compound B-1 were added to a 1000 mL recovery flask and stirred thoroughly until homogenous. Subsequently, 140 g of a 30% by mass aqueous solution of calcium chloride was added and stirred to produce a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-1.

[0118] Example 1-2 Synthesis of Marine Biodegradable Polymer Compound C-2 200 g of a 50% by mass aqueous solution of anionic polymer compound A-2 and 400 g of a 25% by mass aqueous solution of anionic polymer compound B-2 were added to a 1000 mL recovery flask and stirred thoroughly until homogenous. Subsequently, 175 g of a 30% by mass aqueous solution of calcium chloride was added and stirred to produce a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-2.

[0119] Example 1-3 Synthesis of Marine Biodegradable Polymer Compound C-3 160 g of a 50% by mass aqueous solution of anionic polymer compound A-3 and 480 g of a 25% by mass aqueous solution of anionic polymer compound B-3 were added to a 1000 mL recovery flask and stirred thoroughly until homogenous. Subsequently, 120 g of a 30% by mass aqueous solution of magnesium chloride was added and stirred to produce a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-3.

[0120] Example 1-4 Synthesis of Marine Biodegradable Polymer Compound C-4 320 g of a 50% by mass aqueous solution of anionic polymer compound A-4 and 160 g of a 25% by mass aqueous solution of anionic polymer compound B-1 were added to a 1000 mL recovery flask and stirred thoroughly until homogenous. Subsequently, 110 g of a 30% by mass aqueous solution of calcium chloride was added and stirred to produce a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-4.

[0121] Example 1-5 Synthesis of Marine Biodegradable Polymer Compound C-5 640 g of a 50% by mass aqueous solution of anionic polymer compound A-5 and 160 g of a 25% by mass aqueous solution of anionic polymer compound B-1 were added to a 2000 mL recovery flask and stirred thoroughly until homogenous. Thereafter, 320 g of a 40% by mass aqueous solution of aluminum sulfate was added and stirred to produce a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-5.

[0122] Example 1-6 Synthesis of Marine Biodegradable Polymer Compound C-6 160 g of a 50% by mass aqueous solution of anionic polymer compound A-1 and 480 g of a 25% by mass aqueous solution of anionic polymer compound B-4 were added to a 1000 mL recovery flask and stirred thoroughly until homogenous. Subsequently, 360 g of a 30% by mass aqueous solution of calcium chloride was added and stirred to produce a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-6.

[0123] Example 1-7 Synthesis of Marine Biodegradable Polymer Compound C-7 120 g of a 50% by mass aqueous solution of anionic polymer compound A-3 and 560 g of a 25% by mass aqueous solution of anionic polymer compound B-5 were added to a 1000 mL recovery flask and stirred thoroughly until homogenous. Subsequently, 130 g of a 30% by mass aqueous solution of calcium chloride was added and stirred to produce a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-7.

[0124] Example 1-8 Synthesis of Marine Biodegradable Polymer Compound C-8 240 g of a 50% by mass aqueous solution of anionic polymer compound A-1, 80 g of a 50% by mass aqueous solution of anionic polymer compound A-2, and 160 g of a 25% by mass aqueous solution of anionic polymer compound B-1 were added to a 1000 mL recovery flask and stirred thoroughly until homogenous. Subsequently, 160 g of a 30% by mass aqueous solution of calcium chloride was added, and stirring produced a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-8.

[0125] Example 1-9 Synthesis of Marine Biodegradable Polymer Compound C-9 To a 1000 mL recovery flask, 320 g of a 50% by mass aqueous solution of anionic polymer compound A-1, 80 g of a 25% by mass aqueous solution of anionic polymer compound B-1, and 80 g of a 25% by mass aqueous solution of anionic polymer compound B-3 were added and stirred thoroughly until homogeneous. Subsequently, 130 g of a 30% by mass aqueous solution of calcium chloride was added, and stirring produced a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain marine biodegradable polymer compound C-9.

[0126] Comparative Example 1-1 Synthesis of Marine Biodegradable Polymer Compound X-1 To a 1000 mL recovery flask, 400 g of a 50 mass % aqueous solution of anionic polymer compound A-2 was added, followed by addition of 180 g of a 30 mass % aqueous solution of calcium chloride, and stirring resulted in the formation of a precipitate. The precipitate was washed with water and then dried under reduced pressure to obtain Marine Biodegradable Polymer Compound X-1.

[0127] Marine biodegradable polymer compounds C-1 to C-9 and X-1 are summarized in Table 4 below.

[0128]

[0129] [5] Preparation of Marine Biodegradable Resin Compositions and Confirmation Tests in Seawater - 1 (1) Surface Changes [Examples 2-1 to 2-9, Comparative Examples 2-1 to 2-2] The biodegradable resin PBSA (FD-92, manufactured by Mitsubishi Chemical Corporation) was crushed using a crusher (Wonder Blender WB-1, manufactured by Osaka Chemical Co., Ltd.) and sieved through a stainless steel sieve (26 μm mesh). The resulting mixture was melt-kneaded at 140°C with the marine biodegradable polymer compounds C-1 to C-9 and X-1 to a concentration of 20% by mass. The resulting mixture was then press-molded at 150°C to produce a 200 μm thick film (Examples 2-1 to 2-9, Comparative Example 2-1). Also, PBSA itself (not containing the marine biodegradable polymer compounds) was press-molded at 150°C to produce a 200 μm thick film (Comparative Example 2-2). The resulting films were cut into 10 mm square pieces and placed in 200 mL of ion-exchanged water and 200 mL of seawater (collected from Tokyo Bay (Chiba Port, Chiba Prefecture)), and left to stand at 25°C for 7 and 30 days, respectively. The films were then removed and their surfaces and appearances were observed using a scanning electron microscope. The results are shown in Table 5.

[0130]

[0131] From the results shown in Table 5, it is believed that, in addition to the disintegration caused by seawater, the presence of microorganisms in seawater also promotes biodegradation.

[0132] (2) Weight Loss of Composite Resin [Examples 3-1 to 3-9, Comparative Examples 3-1 to 3-2] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-9 and X-1 to PBSA, 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 progress of weight loss after immersion was observed after 30, 60, and 90 days. The results are shown in Table 6.

[0133]

[0134] From the results shown in Table 6, it is believed that biodegradation is promoted by the presence of microorganisms in seawater as well as by the disintegration caused by seawater.

[0135] (3) Tensile Strength Measurement [Examples 4-1 to 4-9, Comparative Example 4-1] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-9 and X-1 to PBSA at concentrations of 10 mass%, 20 mass%, or 30 mass%, respectively, as well as films of PBSA alone. According to JIS K 7139-A22, dumbbells were prepared from various films, and the tensile stress (yield point) was measured using a universal testing machine (MCT-2150, manufactured by A&D Co., Ltd.). Five measurements were taken for each sample, and the average value was used as the tensile stress. The results are shown in Table 7.

[0136]

[0137] From the results shown in Table 7, it was confirmed that the marine biodegradable polymer compound of the present invention has improved mechanical properties compared to X-1.

[0138] (4) Softening Point Measurement [Examples 5-1 to 5-9, Comparative Example 5-1] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-9 and X-1 to PBSA at concentrations of 10%, 20%, or 30% by mass, respectively, as well as films of PBSA alone. The softening points of the marine biodegradable polymer compounds C-1 to C-9 and X-1 were measured using a thermomechanical analyzer (TMA4000SE, manufactured by NETZSCH Japan Co., Ltd.). Specifically, a test specimen measuring 200 μm in thickness, 150 mm in length, and 3 mm in width was stretched with a 10 g load over a temperature range of 0 to 180°C (heating rate of 3°C / min), and the temperature at which 1 mm of elongation was observed was recorded as the softening point. The results are shown in Table 8.

[0139]

[0140] From the results shown in Table 8, it was confirmed that the marine biodegradable polymer compound of the present invention has improved thermal properties compared to X-1.

[0141] [6] Preparation of Marine Biodegradable Resin Compositions and Confirmation Tests in Seawater - 2 (1) Surface Changes [Examples 6-1 to 6-9, Comparative Examples 6-1 to 6-2] A starch-based resin (Mater-Bi EF05B, manufactured by Novamont) was crushed using a crusher (Wonder Blender WB-1, manufactured by Osaka Chemical Co., Ltd.) and sieved through a stainless steel sieve (26 μm mesh). The resulting mixture was melt-kneaded at 140 °C to a concentration of 20% by mass with the marine biodegradable polymer compounds C-1 to C-9 and X-1, respectively, and then press-molded at 150 °C to produce a 200 μm thick film (Examples 6-1 to 6-9, Comparative Example 6-1). Furthermore, the starch-based resin itself (not including the marine biodegradable polymer compound) was press-molded at 150 °C to produce a 200 μm thick film (Comparative Example 6-2). The obtained films were cut into 10 mm square pieces and placed in 200 mL of ion-exchanged water and 200 mL of seawater (collected from Tokyo Bay (Chiba Port, Chiba Prefecture)), and left to stand at 25°C for 7 and 30 days, respectively. The films were then removed and their surfaces and appearances were observed using a scanning electron microscope. The results are shown in Table 9.

[0142]

[0143] From the results shown in Table 9, it is believed that biodegradation is promoted by the presence of microorganisms in seawater as well as by the disintegration caused by seawater.

[0144] (2) Weight Loss of Composite Resins [Examples 7-1 to 7-9, Comparative Examples 7-1 to 7-2] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-9 and X-1 to starch-based resins, as well as films of starch-based resins alone. The resulting 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 progress of weight loss after immersion was observed after 30, 60, and 90 days. The results are shown in Table 10.

[0145]

[0146] From the results shown in Table 10, it is believed that, in addition to the disintegration caused by seawater, the presence of microorganisms in seawater also promotes biodegradation.

[0147] (3) Tensile Strength Measurement [Examples 8-1 to 8-9, Comparative Example 8-1] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-9 and X-1 to starch-based resins at concentrations of 10 mass%, 20 mass%, or 30 mass%, respectively, as well as films of starch-based resins alone. According to JIS K 7139-A22, dumbbells were prepared from the various films, and the tensile stress (yield point) was measured using a universal testing machine (MCT-2150, manufactured by A&D Co., Ltd.). Five measurements were taken for each sample, and the average value was used as the tensile stress. The results are shown in Table 11.

[0148]

[0149] From the results shown in Table 11, it was confirmed that the marine biodegradable polymer compound of the present invention has improved mechanical properties compared to X-1.

[0150] (4) Softening Point Measurement [Examples 9-1 to 9-9, Comparative Example 9-1] Using the same method as in (1), films were prepared by adding marine biodegradable polymer compounds C-1 to C-9 and X-1 to starch-based resins at concentrations of 10%, 20%, or 30% by mass, respectively, as well as films of starch-based resins alone. The softening points of marine biodegradable polymer compounds C-1 to C-9 and X-1 were measured using a thermomechanical analyzer (TMA4000SE, manufactured by NETZSCH Japan Co., Ltd.). Specifically, a 200 μm thick, 150 mm long, and 3 mm wide test piece was stretched with a 10 g load over a temperature range of 0 to 180 °C (heating rate of 3 °C / min), and the temperature at which 1 mm of elongation was observed was recorded as the softening point. The results are shown in Table 12.

[0151]

[0152] From the results shown in Table 12, it was confirmed that the marine biodegradable polymer compound of the present invention has improved thermal properties compared to X-1.

[0153] From the above results, the marine biodegradable polymer compound of the present invention is biodegraded in seawater before the biodegradable resin, and is broken down into smaller molecules or salt-substituted, which makes it more likely to dissolve or become hydrophilic. Therefore, by adding a marine biodegradation promoter consisting of the marine biodegradable polymer compound of the present invention to a resin composition that is biodegradable in soil or compost or a resin composition that is poorly biodegradable in the ocean, it becomes possible to create irregularities in seawater, which helps microbial adhesion and promotes biodegradation, thereby ultimately improving overall marine biodegradability and reducing the environmental burden. By combining the marine biodegradation promoter made of the marine biodegradable polymer compound of the present invention with a resin that is biodegradable in soil or compost, it is possible to improve seawater biodegradability, and by appropriately modifying the structure of the organic anion, it is possible to incorporate multiple effects, such as adjusting the melting temperature and viscosity, adjusting the degree of crystallinity, adjusting the adhesion and biodegradability of microorganisms, adjusting physical properties such as the resin tensile strength, flexural strength, and elasticity, improving compatibility with the resin, adjusting the degree of hydrophobicity, adjusting the hydrophobicity, and adjusting the adhesion and plasticity, and it is possible to improve both the biodegradability and physical properties of the marine biodegradable resin composition.

Claims

1. A marine biodegradable polymer compound in which an anionic polymer compound A has a linear or branched main chain, a total of two or more monovalent anionic groups at the ends of the main chain, and no ionic groups in the side chains, and an anionic polymer compound B has monovalent anionic groups in the side chains of two or more repeating units, bonded via a divalent or higher metal cation.

2. The polymer compound according to claim 1, wherein the mass ratio of the anionic polymer compound A to the anionic polymer compound B is from 99:1 to 10:

90.

3. The polymer compound according to claim 1, wherein the main chain of the anionic polymer compound A is linear.

4. The polymer compound according to claim 1, wherein the anionic polymer compound B contains a repeating unit having no ionic group.

5. The polymer compound according to claim 1, wherein the anionic polymer compound B has an aliphatic unsaturated carbon-carbon bond in the main chain.

6. The polymer compound according to claim 1, wherein the monovalent anionic group of the anionic polymer compound A is a carboxylate anion.

7. The polymer compound according to claim 1, wherein the monovalent anionic group of the anionic polymer compound B is a carboxylate anion or a sulfonate anion.

8. The polymer compound according to claim 1, wherein the monovalent anionic group of the anionic polymer compound B is bonded to a ring.

9. The polymer compound according to claim 1, wherein the anionic polymer compound A has a number average molecular weight of 500 to 10,000, and the anionic polymer compound B has a number average molecular weight of 500 to 10,000.

10. The polymer compound according to claim 1, wherein the anionic polymer compound A has repeating units bonded together through at least one bond selected from the group consisting of ester bonds, amide bonds, ether bonds and urethane bonds, and the anionic polymer compound B has repeating units bonded together through at least one bond selected from the group consisting of ester bonds, amide bonds, ether bonds and urethane bonds.

11. The polymer compound according to claim 1, wherein the value obtained by dividing the number average molecular weight of the anionic polymer compound B by the average number of monovalent anionic groups in one molecule is 100 to 5,000.

12. The content of the divalent or higher metal cation is 1 to 300 eq / 10 5 2. The polymer compound according to claim 1, wherein 13. The polymer compound according to claim 1, wherein the divalent or higher metal cation is a calcium ion, a magnesium ion or an aluminum ion.

14. A marine biodegradation promoter comprising the marine biodegradable polymer compound according to any one of claims 1 to 13.

15. A marine biodegradable resin composition comprising the marine biodegradation promoter according to claim 14 and a resin.

16. The marine biodegradable resin composition according to claim 15, wherein the resin is a biodegradable resin.

17. The marine biodegradable resin composition according to claim 15, wherein the content of the marine biodegradation promoter is 1 to 50 mass %, and the content of the resin is 50 to 99 mass %.

18. A molded article obtained from the marine biodegradable resin composition according to claim 15.

19. A method for producing a marine biodegradable polymer compound, comprising a step of crosslinking an anionic polymer compound A having a linear or branched main chain, a total of two or more monovalent anionic groups at the ends of the main chain, and no ionic groups in its side chain, and an anionic polymer compound B having monovalent anionic groups in the side chains of at least two repeating units, with a divalent or higher metal cation.

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