Polysaccharide-based biomass plastic, resin composition for molding using same, and molded body

Abstract

Provided are: a polysaccharide-based biomass plastic having both marine biodegradability and good mechanical strength and thermoplastic properties; a resin composition for molding, in which the polysaccharide-based biomass plastic is used; and a molded body.　The polysaccharide-based biomass plastic comprises a polysaccharide derivative and a biodegradable resin. In the polysaccharide derivative, hydrogen atoms in hydroxyl groups in a polysaccharide (cellulose or paramylon) are substituted by a long-chain component that is a C6-18 saturated aliphatic acyl group and a short-chain component that is a C2 or C3 acyl group, wherein the total of the degree of substitution by the long-chain component and the degree of substitution by the short-chain component is 2.4-2.6 in the case of a cellulose derivative and is 1.6-2.3 in the case of a paramylon derivative, and the degree of substitution by the long-chain component is 0.6 or more. The biodegradable resin comprises at least one component selected from the group consisting of PBS, PBSA, and PCL. In the polysaccharide-based biomass plastic, the content of the polysaccharide derivative is 70-90 mass%, and the content of the biodegradable resin is 10-30 mass%.

Description

Polysaccharide-based biomass plastic, molding resin composition using same, and molded article

[0001] The present disclosure relates to a polysaccharide-based biomass plastic, a molding resin composition using the same, and a molded article.

[0002] In recent years, plant-derived biomass plastics have become increasingly important from the perspectives of reducing environmental impact and achieving carbon neutrality. Furthermore, as marine plastic waste has become a problem, marine biodegradable plastics have also attracted increasing attention. Examples of mass-produced marine biodegradable biomass plastics include polyhydroxyalkanoate (PHA) resins and bio-polybutylene succinate (Bio-PBS) resins, which are produced by microorganisms. However, while these PHA resins and Bio-PBS resins are highly biodegradable, they lack durability and therefore cannot be said to be suitable for applications such as fishing gear and fishing nets, which require both marine biodegradability and durability.

[0003] In light of this, attention has been drawn to polysaccharide derivatives obtained by esterifying the hydroxyl groups of the glucose rings of polysaccharides with fatty acids. For example, Patent Document 1 describes a β-1,3-glucan derivative in which a long-chain aliphatic hydrocarbon group having 13 or more carbon atoms and a short-chain aliphatic hydrocarbon group having 1 to 5 carbon atoms or a phenyl group are introduced into β-1,3-glucan.

[0004] Patent No. 6029155

[0005] However, polysaccharide derivatives that exhibit good mechanical strength and thermoplasticity are generally known to be non-biodegradable due to their high degree of hydroxyl group substitution. Therefore, there is a demand for polysaccharide-based bioplastics that combine marine biodegradability with good mechanical strength and thermoplasticity.

[0006] An object of the present disclosure is to provide a polysaccharide-based biomass plastic that combines marine biodegradability with good mechanical strength and thermoplasticity, and a molding resin composition and molded article using the same.

[0007] In order to achieve the above object, the present disclosure provides a cellulose derivative in which hydrogen atoms of hydroxy groups of cellulose are substituted with long-chain components which are saturated aliphatic acyl groups having 6 to 18 carbon atoms and short-chain components which are acyl groups having 2 or 3 carbon atoms, and the degree of substitution with the long-chain components (DS Ｌｏ ) and the degree of substitution by the short chain component (DS Ｓｈ ) is in the range of 2.4 to 2.6, and the degree of substitution with the long chain component (DS Ｌｏ and a biodegradable resin which is one or more selected from the group consisting of polybutylene succinate, polybutylene succinate adipate, and polycaprolactone, wherein the content of the cellulose derivative is 70 to 90% by mass relative to 100% by mass of the total content of the cellulose derivative and the biodegradable resin, and the content of the biodegradable resin is 10 to 30% by mass relative to 100% by mass of the total content of the cellulose derivative and the biodegradable resin.

[0008] The present disclosure also provides a paramylon derivative in which the hydrogen atoms of the hydroxyl groups of paramylon are substituted with a long-chain component that is a saturated aliphatic acyl group having 6 to 18 carbon atoms and a short-chain component that is an acyl group having 2 or 3 carbon atoms, and the degree of substitution with the long-chain component (DS Ｌｏ ) and the degree of substitution by the short chain component (DS Ｓｈ ) is in the range of 1.6 to 2.3, and the degree of substitution with the long chain component (DS Ｌｏ ) is 0.6 or more, and a biodegradable resin which is one or more selected from the group consisting of polybutylene succinate, polybutylene succinate adipate, and polycaprolactone, wherein the content of the paramylon derivative is 70 to 90% by mass relative to 100% by mass of the total content of the paramylon derivative and the biodegradable resin, and the content of the biodegradable resin is 10 to 30% by mass relative to 100% by mass of the total content of the paramylon derivative and the biodegradable resin.

[0009] The present disclosure also relates to a molding resin composition containing the polysaccharide-based biomass plastic, and a molded article formed using the same.

[0010] Furthermore, the present disclosure relates to a method for producing a polysaccharide-based biomass plastic, comprising the steps of: reacting cellulose or paramylon dispersed in a solvent with: a short-chain acylating agent which is one or more selected from the group consisting of fatty acid halides and acid anhydrides having 2 or 3 carbon atoms; and a long-chain acylating agent which is one or more selected from the group consisting of saturated fatty acid halides and acid anhydrides having 6 to 18 carbon atoms, under heating in the presence of an acid scavenger component, to prepare a cellulose derivative or paramylon derivative by acylation of the hydroxy groups of the cellulose or paramylon; and mixing the cellulose derivative or paramylon derivative with a biodegradable resin to form an alloy.

[0011] According to the present disclosure, it is possible to provide a polysaccharide-based biomass plastic that combines marine biodegradability with good mechanical strength and thermoplasticity, as well as a molding resin composition and a molded article using the same.

[0012] Biomass plastics are polymeric materials obtained by chemical or biological synthesis using substances derived from renewable organic resources. Even when biomass plastics are incinerated, they are carbon-neutral, meaning that they reduce carbon dioxide emissions into the atmosphere compared to petroleum-derived resins, and are therefore expected to reduce the burden on the environment.

[0013] <Polysaccharide-Based Biomass Plastic> The polysaccharide-based biomass plastic of the present disclosure is composed of a specific polysaccharide derivative (cellulose derivative or paramylon derivative) and a specific biodegradable resin. In the present disclosure, by compounding and alloying the polysaccharide derivative and biodegradable resin, it is possible to obtain excellent marine biodegradability, impact strength, and thermoplasticity. Here, "compounding" refers to the process of mixing a raw resin with other resins and optional additives to process it into a resin with a new appearance, physical properties, and function. Furthermore, "alloying" refers to the technique of blending two or more raw materials to create a raw material with properties that complement the characteristics of both. The polysaccharide-based biomass plastic of the present disclosure preferably has a biodegradation value (relative to cellulose) of 10% or more, more preferably 10 to 30%, after three months in a BOD test using seawater. The polysaccharide-based biomass plastic of the present disclosure has a Charpy impact strength of 5 kJ / m ２ As a result, the material has good mechanical strength.

[0014] The content of the specific polysaccharide derivative is 70 to 90% by mass, preferably 80 to 90% by mass, and more preferably 83 to 90% by mass, relative to 100% by mass of the total content of the polysaccharide derivative and biodegradable resin. When the content of the polysaccharide derivative is within the above range, the polysaccharide-based biomass plastic can possess both marine biodegradability and good mechanical strength and thermoplasticity. If the amount of biodegradable resin is too small, the molded product may not have sufficient mechanical strength, while if the amount of biodegradable resin is too large, the physical properties of the polysaccharide-based biomass plastic may be reduced due to crystallization (clouding).

[0015] The content of the specific biodegradable resin is 10 to 30% by mass, preferably 10 to 20% by mass, and more preferably 10 to 17% by mass, relative to 100% by mass of the total content of the polysaccharide derivative and the biodegradable resin. When the content of the biodegradable resin is within the above range, the polysaccharide-based biomass plastic can possess both marine biodegradability and good mechanical strength and thermoplasticity. If the content of the biodegradable resin is too high, the physical properties of the polysaccharide-based biomass plastic may be reduced due to crystallization (cloudiness). If the content of the biodegradable resin is too low, the mechanical strength of the molded body may be poor.

[0016] [Polysaccharide Derivatives] (1) Cellulose Derivatives The cellulose derivatives according to the present disclosure are those into which long-chain components and short-chain components are introduced by utilizing the hydroxyl groups of cellulose. The cellulose derivatives according to the present disclosure are cellulose derivatives in which the hydrogen atoms of the hydroxyl groups of cellulose are substituted with short-chain components, which are acyl groups having 2 or 3 carbon atoms, and long-chain components, which are saturated aliphatic acyl groups having 6 to 18 carbon atoms, and the degree of substitution with the long-chain components (DS Ｌｏ ) and the degree of substitution by the short chain component (DS Ｓｈ ) is in the range of 2.4 to 2.6, and the degree of substitution with the long chain component (DS Ｌｏ ) is 0.6 or more.

[0017] (Cellulose) Cellulose is a linear polymer formed by the polymerization of β-D-glucose molecules (β-D-glucopyranose) via β(1→4) glycosidic bonds, as shown in the following formula (1) (where n is a natural number). Each glucose unit constituting cellulose has three hydroxy groups. In the present disclosure, these hydroxy groups can be used to introduce short-chain and long-chain components into such cellulose.

[0018]

[0019] (Long-Chain Component) By introducing a long-chain component into cellulose, the properties of the cellulose derivative of the present disclosure can be modified, for example, improving water resistance, thermoplasticity, and mechanical strength. The long-chain component is a saturated aliphatic acyl group having 6 to 18 carbon atoms, preferably a linear saturated aliphatic acyl group having 6 to 18 carbon atoms, more preferably a linear saturated aliphatic acyl group having 6 to 12 carbon atoms, and even more preferably a linear saturated aliphatic acyl group having 6 carbon atoms. This long-chain component may be one type alone or two or more types.

[0020] The long-chain component is an acyl group derived from a long-chain acylating agent introduced in place of a hydrogen atom of a hydroxy group of cellulose. The long-chain component can be introduced by reacting the hydroxy group in cellulose with a long-chain acylating agent (described later). The long-chain organic group of the long-chain component can be bonded to the pyranose ring of cellulose via an ester bond.

[0021] (Short-Chain Components) By introducing short-chain components into cellulose, the polysaccharide derivative of the present disclosure can reduce the intermolecular forces (intermolecular bonds) of cellulose, thereby improving the mechanical strength such as elastic modulus, and physical properties such as chemical resistance and surface hardness. The short-chain components are acyl groups (acetyl groups and / or propionyl groups) having 2 or 3 carbon atoms, preferably containing at least acetyl groups, and particularly preferably containing only acetyl groups.

[0022] The short-chain component is an acyl group derived from a short-chain acylating agent introduced in place of a hydrogen atom of a hydroxy group of cellulose. The short-chain component can be introduced by reacting the hydroxy group in cellulose with a short-chain acylating agent (described later). The short-chain organic group of the short-chain component and the pyranose ring of cellulose can be bonded via an ester bond.

[0023] Degree of substitution by long chain components of cellulose (DS Ｌｏ), that is, the average number of hydroxyl groups substituted with long-chain components (saturated aliphatic acyl groups having 6 to 18 carbon atoms) per glucose unit of cellulose (degree of hydroxyl group substitution) is 0.6 or more, preferably in the range of 0.8 to 2.0, and more preferably in the range of 1.0 to 1.8, from the viewpoint of achieving both mechanical strength and marine biodegradability. Ｌｏ If the value is less than 0.6, the mechanical strength may be poor.

[0024] Degree of substitution by long chain components of cellulose (DS Ｌｏ ) and the degree of substitution by short chain components (DS Ｓｈ ), i.e., the average number of hydroxyl groups substituted with short-chain components (acetyl groups and / or propionyl groups) per glucose unit of cellulose (degree of hydroxyl group substitution) is in the range of 2.4 to 2.6, preferably in the range of 2.45 to 2.55, and more preferably in the range of 2.5 to 2.55, from the viewpoint of achieving both mechanical strength and marine biodegradability. Ｌｏ and DS Ｓｈ If DS is too low, the mechanical strength of the produced resin may be insufficient. Ｌｏ and DS Ｓｈ If the pH is too high, marine biodegradability may be reduced.

[0025] (2) Paramylon Derivatives The paramylon derivatives according to the present disclosure are those in which long-chain and short-chain components have been introduced using the hydroxyl groups of paramylon. The paramylon derivatives according to the present disclosure are paramylon derivatives in which the hydrogen atoms of the hydroxyl groups of paramylon have been substituted with short-chain components that are acyl groups (acetyl and / or propionyl groups) having 2 or 3 carbon atoms and long-chain components that are saturated aliphatic acyl groups having 6 to 18 carbon atoms, and the degree of substitution with the long-chain components (DS) Ｌｏ ) and the degree of substitution by the short chain component (DS Ｓｈ ) is in the range of 1.6 to 2.3, and the degree of substitution with the long chain component (DS Ｌｏ ) is 0.6 or more.

[0026] (Paramylon) Paramylon is a linear polymer formed by the polymerization of β-D-glucose molecules (β-D-glucopyranose) via β(1→3) glycosidic bonds, as shown in the following formula (2) (where n is a natural number). Each glucose unit constituting paramylon has three hydroxy groups. In the present disclosure, these hydroxy groups can be used to introduce short-chain and long-chain components into such paramylon.

[0027] Paramylon is the main component of algae and is obtained by separating other components such as proteins from algae. Paramylon is a polysaccharide accumulated in Euglena as a storage polysaccharide, and is either stored or consumed as an energy source depending on the nutritional and other environmental conditions. Paramylon consists only of glucose, and the average degree of polymerization of paramylon obtained from Euglena gracilis is known to be approximately 700-750 glucose units.

[0028] (Long-Chain Component) The properties of the paramylon derivative of the present disclosure can be modified by introducing a long-chain component into paramylon, for example, improving water resistance, thermoplasticity, and mechanical strength. The long-chain component is a saturated aliphatic acyl group having 6 to 18 carbon atoms, preferably a linear saturated aliphatic acyl group having 6 to 18 carbon atoms, more preferably a linear saturated aliphatic acyl group having 6 to 12 carbon atoms, and even more preferably a linear saturated aliphatic acyl group having 6 carbon atoms. This long-chain component may be one type alone or two or more types.

[0029] The long-chain component is an acyl group derived from a long-chain acylating agent introduced in place of the hydrogen atom of the hydroxy group of paramylon. The long-chain component can be introduced by reacting the hydroxy group in paramylon with a long-chain acylating agent (described below). The long-chain organic group of the long-chain component can be bonded to the pyranose ring of paramylon via an ester bond.

[0030] (Short-Chain Components) By introducing short-chain components into paramylon, the paramylon derivatives of the present disclosure can reduce the intermolecular forces (intermolecular bonds) of paramylon, thereby improving mechanical strength such as elastic modulus, as well as physical properties such as chemical resistance and surface hardness. The short-chain components are acyl groups (acetyl groups and / or propionyl groups) having 2 or 3 carbon atoms, preferably containing at least acetyl groups, and particularly preferably consisting of only acetyl groups.

[0031] The short-chain components are acyl groups derived from short-chain acylating agents introduced in place of hydrogen atoms in the hydroxyl groups of paramylon. The short-chain components can be introduced by reacting the hydroxyl groups in paramylon with the short-chain acylating agents described below. The short-chain organic groups of the short-chain components can be bonded to the pyranose rings of paramylon via ester bonds.

[0032] Degree of substitution by long chain components of paramylon (DS Ｌｏ ), that is, the average number of hydroxyl groups substituted with long-chain components (saturated aliphatic acyl groups having 6 to 18 carbon atoms) per glucose unit of paramylon (degree of hydroxyl group substitution) is 0.6 or more, preferably in the range of 0.8 to 2.0, and more preferably in the range of 1.0 to 1.8, from the viewpoint of achieving both mechanical strength and marine biodegradability. Ｌｏ If the value is less than 0.6, the mechanical strength may be poor.

[0033] Degree of substitution by long chain components of paramylon (DS Ｌｏ ) and the degree of substitution by short chain components (DS Ｓｈ ), that is, the sum of the average number of hydroxyl groups substituted with short-chain components (acetyl groups and / or propionyl groups) per glucose unit of paramylon (degree of hydroxyl group substitution) is in the range of 1.6 to 2.3, preferably in the range of 1.7 to 2.2, and more preferably in the range of 1.7 to 2.1, from the viewpoint of achieving both mechanical strength and marine biodegradability. Ｌｏ and DS Ｓｈ If DS is too low, the mechanical strength of the produced resin may be insufficient. Ｌｏ and DS Ｓｈ If the pH is too high, marine biodegradability may be reduced.

[0034] [Method for producing polysaccharide-based resins (cellulose-based resins and paramylon-based resins)] The cellulose-based resins and paramylon-based resins (also referred to as "polysaccharide-based resins") used in the present disclosure can be produced, for example, by the following production method. Hereinafter, cellulose and paramylon will also be referred to as "polysaccharides."

[0035] (Activation of Polysaccharides) Before the reaction step for introducing long-chain components and short-chain components into polysaccharides (cellulose and / or paramylon), an activation treatment (pretreatment step) can be carried out to increase the reactivity of the polysaccharides. As this activation treatment, the activation treatment usually carried out before acetylation of polysaccharides can be applied.

[0036] Activation treatments can be performed using wet methods, such as spraying an activating solvent compatible with the polysaccharide onto the polysaccharide or immersing the polysaccharide in the activating solvent (immersion method), to bring the polysaccharide into contact with the solvent and swell the polysaccharide. This facilitates penetration of the reactant between the polysaccharide molecular chains (or, if a solvent or catalyst is used, facilitates penetration along with the solvent or catalyst), thereby improving the reactivity of the polysaccharide. Examples of activating solvents include water; carboxylic acids such as acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, and stearic acid; alcohols such as methanol, ethanol, propanol, and isopropanol; nitrogen-containing compounds such as dimethylformamide, formamide, ethanolamine, and pyridine; and sulfoxide compounds such as dimethyl sulfoxide. These may be used alone or in combination. Water, acetic acid, pyridine, and dimethyl sulfoxide are particularly preferred.

[0037] Activation can also be carried out by adding a polysaccharide to the long-chain fatty acid. If the melting point of the long-chain fatty acid is room temperature or higher, it can also be heated to the melting point or higher.

[0038] The amount of the activating solvent used can be set to, for example, 10 parts by mass or more, preferably 20 parts by mass or more, and more preferably 30 parts by mass or more, per 100 parts by mass of the polysaccharide. When the polysaccharide is immersed in the activating solvent, the amount can be set to, for example, 1 time or more, preferably 5 times or more, and more preferably 10 times or more, by mass, relative to the polysaccharide. From the viewpoints of reducing the burden of removing the activating solvent after pretreatment and reducing material costs, the amount of the activating solvent is preferably 300 times or less, more preferably 100 times or less, and even more preferably 50 times or less, relative to the polysaccharide.

[0039] The temperature of the activation treatment can be appropriately set, for example, in the range of 0 to 100° C. From the viewpoint of activation efficiency and reducing energy costs, the temperature of the activation treatment is preferably 10 to 40° C., more preferably 15 to 35° C.

[0040] When the polysaccharide is added to the melted long-chain fatty acid, the mixture can be heated to a temperature equal to or higher than the melting point of the long-chain fatty acid.

[0041] The activation treatment time can be set appropriately within the range of, for example, 0.1 to 72 hours. From the viewpoint of performing sufficient activation and reducing the treatment time, the activation treatment time is preferably 0.1 to 24 hours, and more preferably 0.5 to 3 hours.

[0042] After the activation treatment, excess activation solvent can be removed by a solid-liquid separation method such as suction filtration, filter press, or squeezing.

[0043] After the activation treatment, the activation solvent contained in the polysaccharide can be replaced with the solvent used in the reaction. For example, the replacement treatment can be carried out by the immersion method of the activation treatment described above, except that the activation solvent is replaced with the solvent used in the reaction.

[0044] (Method for introducing long-chain and short-chain components) The polysaccharide derivatives according to the present disclosure can be produced by the following method.

[0045] In one embodiment, a method for producing a polysaccharide derivative includes a step of reacting a polysaccharide dispersed in a solvent with a short-chain reactant (short-chain acylating agent) and a long-chain reactant (long-chain acylating agent) under heating in a solvent in the presence of an acid scavenger component to acylate the hydroxy groups of the polysaccharide. The short-chain reactant (short-chain acylating agent) and the long-chain reactant (long-chain acylating agent) are preferably dissolved in the solvent. The acid scavenger component can also be used as the solvent.

[0046] As a long-chain reactant for introducing a long-chain component into a polysaccharide, an acid chloride of a saturated fatty acid (preferably an acid chloride of a linear saturated fatty acid) is preferred. As a long-chain acylating agent, for example, a saturated fatty acid halide having 6 to 18 carbon atoms can be used, and one type may be used alone or two or more types may be used in combination. A specific example of a saturated fatty acid having 6 to 18 carbon atoms is caproic acid (C ６ ), enanthic acid (C ７ ), caprylic acid (C ８ ), pelargonic acid (C ９ ), capric acid (C １０ ), undecylic acid (C １１ ), lauric acid (C １２ ), tridecylic acid (C １３ ), myristic acid (C １４ ), pentadecylic acid (C １５ ), palmitic acid (C １６ ), margaric acid (C １７ ), stearic acid (C １８ Of these, caproic acid, caprylic acid, and lauric acid are preferred, with caproic acid being more preferred. Furthermore, from the viewpoint of environmental friendliness, saturated fatty acids that are obtained from natural sources are preferred.

[0047] The short-chain acylating agent is a compound having at least one functional group capable of reacting with the hydroxyl groups in cellulose or paramylon. Examples of the short-chain acylating agent include fatty acid halides having two or three carbon atoms (acetic acid or propionic acid), with acetyl chloride and / or propionyl chloride being preferred, and acetyl chloride being more preferred.

[0048] As the solvent, a solvent that has a liquid retention rate of 90 vol % or more when used with cotton fiber filter paper can be used.

[0049] The "liquid retention rate" can be measured by the following method. Cotton fiber filter paper (5B, 40 mm diameter, moisture content approximately 2%) is immersed in each solvent at room temperature for 1 hour. The weight is measured before and after immersion, and the liquid retention rate (vol%) is calculated using the formula below. After immersion, the weight is measured when the solvent stops dripping from the sample.

[0050] Liquid retention rate (vol%)=(weight after immersion−weight before immersion) / weight before immersion / specific gravity of solvent×100

[0051] Examples of solvents that achieve a liquid retention rate of 90 vol% or more by the above method include water (liquid retention rate 145 vol%), acetic acid (liquid retention rate 109 vol%), dioxane (liquid retention rate 93 vol%), pyridine (liquid retention rate 109 vol%), N-methylpyrrolidone (liquid retention rate 104 vol%), N,N-dimethylacetamide (liquid retention rate 112 vol%), N,N-dimethylformamide (liquid retention rate 129 vol%), and dimethyl sulfoxide (liquid retention rate 180 vol%).

[0052] The acid scavenger component is not particularly limited as long as it is a base that neutralizes by-produced acids (hydrochloric acid, acetic acid, propionic acid, etc.), and examples thereof include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides such as calcium hydroxide and barium hydroxide; metal alkoxides such as sodium methoxide and sodium ethoxide; and nitrogen-containing nucleophilic compounds such as diazabicycloundecene, diazabicyclononene, triethylamine, and pyridine. When the acid scavenger component is added separately from the solvent, it is preferable that the acid scavenger component be present in the reaction system from the start of the reaction. As long as the acid scavenger component is present in the reaction system at the start of the reaction, it does not matter whether the acid scavenger component is added before or after the addition of the acylating agent.

[0053] The amount of acid scavenger added is preferably 0.1 to 10 equivalents, more preferably 0.5 to 5 equivalents, relative to the total amount of long-chain acylating agent and short-chain acylating agent charged. However, this range is not limited when a nitrogen-containing nucleophilic compound is used as a solvent. If the amount of acid scavenger added is small, the efficiency of the acylation reaction decreases. Furthermore, if the amount of acid scavenger added is large, paramylon may decompose, resulting in a decrease in molecular weight.

[0054] The reaction temperature in the acylation step is preferably 50 to 100°C, more preferably 60 to 95°C, and even more preferably 70 to 90°C. The reaction time can be appropriately set according to the desired degree of substitution. If the reaction temperature is sufficiently high, the reaction rate can be increased, so that the acylation reaction can be completed in a relatively short time, and the reaction efficiency can be increased. Furthermore, if the reaction temperature is within the above range, a decrease in molecular weight due to heating can be suppressed.

[0055] The amount of the solvent can be set to 10 to 50 times the dry mass of the raw material cellulose or paramylon, and is preferably set to 10 to 40 times (mass ratio).

[0056] (Recovery Step) The polysaccharide derivative (product) into which long-chain components and short-chain components have been introduced can be recovered from the reaction solution by a conventional method, and the method is not limited thereto. When the product is not dissolved in the reaction solution, a recovery method in which the reaction solution and the product are subjected to solid-liquid separation is preferred from the viewpoint of production energy. When the product is soluble in or has an affinity with the reaction solution, making solid-liquid separation difficult, the reaction solution can be distilled off and the product recovered as a residue. Alternatively, a poor solvent for the product can be added to the reaction solution, and the precipitated product can be recovered by solid-liquid separation.

[0057] When the reaction solution is distilled off, the short-chain acylating agent, reaction solvent, and catalyst preferably have low boiling points, but the catalyst can also be removed from the product without being distilled off using a wash solvent, etc. Furthermore, when components other than the product, such as the solvent, are distilled off from the reaction solution, the distillation can be stopped when the product precipitates, and the remaining reaction solution and the precipitated product can then be subjected to solid-liquid separation to recover the product.

[0058] Examples of solid-liquid separation methods include filtration (natural filtration, reduced pressure filtration, pressure filtration, centrifugal filtration, and hot filtration of these), natural sedimentation / floating, liquid separation, centrifugal separation, squeezing, etc., and these may be used in appropriate combinations.

[0059] The polysaccharide derivative (product) dissolved in the filtrate after solid-liquid separation can be precipitated by adding a poor solvent for the product and then recovered by solid-liquid separation. The solid content (polysaccharide derivative) recovered from the reaction solution can be washed as necessary and dried by a conventional method.

[0060] The polysaccharide derivatives produced by this method can have a reinforced crystalline structure due to polysaccharide main chain crystals within a thermoplastic matrix. This is due to the unreacted portion of the polysaccharide raw material acylated. Such polysaccharide main chain crystals can be evaluated, for example, by X-ray diffraction. During this evaluation, the polysaccharide derivative can be pressed to increase its density, making it easier to confirm the signal.

[0061] (Other methods for producing polysaccharide derivatives) In one embodiment, a polysaccharide resin can be obtained by acylation of a polysaccharide in a solid-liquid heterogeneous system using a mixed acid anhydride having a long-chain component and a short-chain component as an acylating agent. The polysaccharide is preferably subjected to an activation treatment. The activation treatment can be carried out by a conventional method.

[0062] Acylation can be carried out by stirring in a solvent (e.g., dioxane, for example, in an amount 80 to 120 times the weight of the dried polysaccharide) that provides a liquid retention rate of 90% or more through cotton fiber filter paper in the presence of an acid catalyst (e.g., sulfuric acid) at 45 to 65°C for 2 to 5 hours, followed by addition of water and aging under heating (e.g., 55 to 75°C) for several hours (e.g., 1 to 3 hours).

[0063] After the reaction is complete, a poor solvent such as a water / methanol mixed solvent is added to thoroughly precipitate the product dissolved in the liquid phase, and the product can be recovered by solid-liquid separation, followed by washing and drying.

[0064] Alternatively, the acylation may be carried out in a homogeneous solution in which the polysaccharide and the acylating agent are dissolved in a solvent. The polysaccharide is preferably subjected to an activation treatment. The activation treatment can be carried out by a conventional method.

[0065] As the solvent for acylation, a solvent having high affinity with polysaccharides, such as N,N-dimethylacetamide, pyridine, or N-methylpyrrolidinone, is used.

[0066] As the acylating agent, a mixed acid anhydride having a long-chain component and a short-chain component can be formed in the same solvent as that used for acylation and used.

[0067] After the reaction is complete, a poor solvent such as methanol is added to precipitate the product, which can then be recovered by solid-liquid separation, followed by washing and drying.

[0068] [Biodegradable Resin] Examples of biodegradable resins include polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), and polycaprolactone (PCL). The biodegradable resins may be used alone or in combination of two or more. By using these specific biodegradable resins, polysaccharide-based biomass plastics with good mechanical strength and thermoplasticity can be obtained.

[0069] <Method for Producing Polysaccharide-Based Biomass Plastic> The method for producing the polysaccharide-based biomass plastic of the present disclosure is not particularly limited, and can be produced, for example, by melt-mixing the polysaccharide derivative and the biodegradable resin by hand mixing or using a known compounding device such as a tumbler mixer, ribbon blender, single-screw or multi-screw mixing extruder, kneader, kneading roll, etc., and, if necessary, granulating the resulting mixture into an appropriate shape. Another suitable production method involves mixing the polysaccharide derivative and the biodegradable resin dispersed in a solvent such as an organic solvent, adding a solidification solvent as necessary to obtain a mixed composition of the polysaccharide derivative and the biodegradable resin, and then evaporating the solvent.

[0070] <Molding Resin Composition> The polysaccharide-based biomass plastic of the present disclosure can be used as a base resin for a molding resin composition. The molding resin composition can contain other components depending on the desired properties, as long as the components do not interfere with the function of the base resin. The polysaccharide-based biomass plastic accounts for 60% by mass or more of the molding resin composition, preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0071] The molding resin composition of the present disclosure can be applied with various additives used in ordinary thermoplastic resins. For example, the addition of a plasticizer can further improve thermoplasticity and elongation at break. Examples of such plasticizers include phthalate esters such as dibutyl phthalate, diaryl phthalate, diethyl phthalate, dimethyl phthalate, di-2-methoxyethyl phthalate, ethylphthalylethyl glycolate, and methylphthalylethyl glycolate; tartaric acid esters such as dibutyl tartrate; adipic acid esters such as dioctyl adipate and diisononyl adipate; polyhydric alcohol esters such as triacetin, diacetylglycerin, tripropionitrile glycerin, and glycerin monostearate; phosphate esters such as triethyl phosphate, triphenyl phosphate, and tricresyl phosphate; dibasic fatty acid esters such as dibutyl adipate, dioctyl adipate, dibutyl azelate, dioctyl azelate, and dioctyl sebacate; citrate esters such as triethyl citrate, acetyltriethyl citrate, and acetyltributyl citrate; Examples of suitable plasticizers include epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil; castor oil and its derivatives; benzoate esters such as ethyl O-benzoylbenzoate; aliphatic dicarboxylic acid esters such as sebacate esters and azelaate esters; unsaturated dicarboxylic acid esters such as maleate esters; N-ethyltoluenesulfonamide, triacetin, O-cresyl p-toluenesulfonate, tripropionin; cyclohexanedicarboxylic acid esters such as dihexyl cyclohexanedicarboxylate, dioctyl cyclohexanedicarboxylate, and di-2-methyloctyl cyclohexanedicarboxylate; trimellitic acid esters such as dihexyl trimellitate, diethylhexyl trimellitate, and dioctyl trimellitate; and pyromellitic acid esters such as dihexyl pyromellitate, diethylhexyl pyromellitate, and dioctyl pyromellitate. These plasticizers can be used alone or in combination of two or more.

[0072] If necessary, inorganic or organic granular or fibrous fillers can be added to the molding resin composition of the present disclosure, which can further improve strength and rigidity. Examples of fillers include mineral particles (talc, mica, calcined silica earth, kaolin, sericite, bentonite, smectite, clay, silica, quartz powder, glass beads, glass powder, glass flakes, milled fiber, wollastonite (or wollastonite), etc.), boron-containing compounds (boron nitride, boron carbide, titanium boride, etc.), metal carbonates (magnesium carbonate, heavy calcium carbonate, light calcium carbonate, etc.), metal silicates (calcium silicate, aluminum silicate, magnesium silicate, magnesium aluminosilicate, etc.), metal oxides (magnesium oxide, etc.), metal hydroxides (aluminum hydroxide, calcium hydroxide, magnesium hydroxide, etc.), metal sulfates (calcium sulfate, barium sulfate, etc.), metal carbides (silicon carbide, aluminum carbide, titanium carbide, etc.), metal nitrides (aluminum nitride, silicon nitride, titanium nitride, etc.), white carbon, and various metal foils. Examples of fibrous fillers include organic fibers (natural fibers, paper, etc.), inorganic fibers (glass fibers, asbestos fibers, carbon fibers, silica fibers, silica-alumina fibers, wollastonite, zirconia fibers, potassium titanate fibers, etc.), metal fibers, etc. These fillers can be used alone or in combination of two or more.

[0073] Glass fibers can be added to the molding resin composition of the present disclosure as needed. The resin composition contains glass fibers, which improves the strength of the molded body. The glass fibers are not particularly limited, but the fiber length of the glass fibers before melt-kneading is preferably 0.5 mm or more, and preferably 30 mm or less, more preferably 10 mm or less. The cross-sectional shape of the glass fibers is not particularly limited, and examples include circular, elliptical, oval, and non-circular. The fiber diameter of the glass fibers, calculated as the cross-sectional area of ​​a perfect circle, may be, for example, 3 to 20 μm.

[0074] A flame retardant can be added to the molding resin composition of the present disclosure as needed. Adding a flame retardant can impart flame retardancy. Examples of flame retardants include metal hydrates such as magnesium hydroxide, aluminum hydroxide, and hydrotalcite, basic magnesium carbonate, calcium carbonate, silica, alumina, talc, clay, zeolite, bromine-based flame retardants, antimony trioxide, phosphate-based flame retardants (e.g., aromatic phosphate esters, aromatic condensed phosphate esters), and compounds containing phosphorus and nitrogen (phosphazene compounds). These flame retardants can be used alone or in combination.

[0075] A hydrolysis inhibitor can be added to the molding resin composition of the present disclosure as needed. The hydrolysis inhibitors may be used alone or in combination of two or more. Examples of hydrolysis inhibitors include compounds having functional groups such as carbodiimide groups, epoxy groups, and oxazoline groups.

[0076] The carbodiimide compound is a compound having one or more carbodiimide groups (-N=C=N-) in the molecule. The carbodiimide compound may be a compound having two or more carbodiimide groups in the molecule, i.e., a polyvalent carbodiimide compound. In one embodiment, the polyvalent carbodiimide compound preferably has 30 or fewer carbodiimide groups in the carbodiimide compound. Furthermore, as the carbodiimide compound, a high-molecular-weight polycarbodiimide produced by a decarboxylation condensation reaction of a diisocyanate in the presence of a carbodiimidization catalyst may be used.

[0077] Examples of carbodiimide compounds include monocarbodiimides such as aliphatic monocarbodiimides, alicyclic monocarbodiimides, and aromatic monocarbodiimides, and polycarbodiimides such as aliphatic polycarbodiimides, alicyclic polycarbodiimides, and aromatic polycarbodiimides. Examples of aliphatic monocarbodiimides include diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, and dioctylcarbodiimide. Examples of alicyclic monocarbodiimides include dicyclohexylcarbodiimide. Examples of aromatic monocarbodiimides include N,N'-diphenylcarbodiimide and N,N'-di-2,6-diisopropylphenylcarbodiimide. Examples of polycarbodiimides include those obtained by a decarboxylation condensation reaction of the following diisocyanates: Examples of such diisocyanates include 1,4-phenylene diisocyanate, 1,3,5-triisopropyl-phenylene-2,4-diisocyanate, 4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4'-diphenylether diisocyanate, 3,3'-dimethyl-4,4'-diphenylether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, and tetramethylxylylene diisocyanate. The number average molecular weight of the polycarbodiimide is not particularly limited, but is preferably 200 or more, more preferably 300 or more, and preferably 20,000 or less.

[0078] The carbodiimide compound may be either a carbodiimide compound having an isocyanate group in the molecule or a carbodiimide compound not having an isocyanate group in the molecule, and can be appropriately selected. In the case of a polycarbodiimide, both ends of the molecule or any part in the molecule may have a functional group such as an isocyanate group, or the molecular chain may be branched, or the molecular structure may be different from that of other parts. In addition, the carbodiimide compound may have a heterocycle or other functional group in the molecule.

[0079] Examples of the epoxy group-containing compound include a glycidyl ester compound, a glycidyl ether compound, etc. Examples of the oxazoline group-containing compound include a bisoxazoline compound, etc.

[0080] The molding resin composition of the present disclosure may further contain phenolic or phosphorus-based antioxidants, light stabilizers, ultraviolet absorbers, antistatic agents, antibacterial and antifungal agents, and the like.

[0081] <Molded Article> The molded article of the present disclosure is produced by molding the molding resin composition, for example, by extrusion molding, injection molding, blow molding, or the like.

[0082] The uses of the molded article of the present disclosure are not particularly limited, but are suitable for, for example, fishing gear and fishing nets, housings and exterior parts of electronic devices and home appliances, interior components of building materials, and automotive interior materials. Applications for electronic devices and home appliances include housings for personal computers, landlines, mobile phone terminals, smartphones, tablets, POS terminals, routers, projectors, speakers, lighting fixtures, copiers, multifunction printers, calculators, remote controls, refrigerators, washing machines, humidifiers, dehumidifiers, video recorders / players, vacuum cleaners, air conditioners, rice cookers, electric shavers, electric toothbrushes, dishwashers, broadcasting equipment, etc., clock dials and exteriors, and cases for mobile devices such as smartphones. Applications for automobiles include interior instrument panels, dashboards, cup holders, door trim, armrests, door handles, door locks, steering wheels, brake levers, ventilators, shift levers, etc.

[0083] The present disclosure will be specifically described below using examples, but the present disclosure is not limited to these examples.

[0084] [1] Marine biodegradability test (1) Samples The amount of each biomass plastic sample used was calculated from the oxygen demand. In the case of alloyed products with biodegradable resins, the molded body was crushed in a tabletop mixer before use. The amount of sample used was the amount that would result in an oxygen consumption (ThOD) of 20 mg / bottle when the sample was completely oxidized. The theoretical oxygen demand of the compound (CcHhClclNnSsPpNanaOo) was calculated using the following formula. Shredded cellulose filter paper Whatman No. 42 was used as a standard sample.

[0085]

[0086] (2) Collection and Preparation of Environmental Water Seawater from Daiba was used as environmental water. Data such as air and water temperatures and pH are shown in Table 1 (Tests 1 to 3 were conducted under condition 2, Tests 4 and 5 under condition 1, and Tests 10, 11, 14, 23, 26 to 29, 31, and 32 under condition 3). Environmental water was collected in a container that had been sterilized with ethanol in advance. Soil was also collected at the time of collection. Then, 2 kg of soil was added to 10 L of environmental water, and the environmental water and soil were thoroughly mixed. While stirring, impurities were removed using a 122 μm nylon mesh, and the mixture was pre-cultured for 7 days to prepare the environmental water and soil for the biodegradation experiments.

[0087]

[0088] (3) BOD Measurement 100 mL of the environmental water for biodegradability testing prepared above, 10 g of soil, and 100 μL of buffer were placed in a 300 mL culture bottle (transparent glass bottle), and the sample was added thereto. The culture bottle was cultured in a thermostatic chamber (25°C), and BOD measurements were carried out for 3 months using OxiTop IDS (WTW). The buffer composition was 0.5 g / L NH4Cl, 0.5 g / L KH ２ P.O. ４ 0.1 g / L, and further allylthiourea was added at 5 mg / L.

[0089] The principle of the BOD test device is as follows: During measurement, oxygen is consumed by microorganisms in the water and carbon dioxide is released. When the released carbon dioxide is absorbed by an absorbent (NaOH), the air pressure inside the bottle decreases. This pressure change is detected by a pressure sensor and the BOD value is calculated.

[0090] BOD biodegradation value (%) = (BODs - BODb) / ThOD x 100 (i) BODs: BOD measurement value of test piece (mg) BODb: BOD measurement value of blank (mg) ThOD: Theoretical oxygen consumption (mL)

[0091] The marine biodegradability of each biomass plastic was evaluated based on the decomposition value relative to cellulose (standard sample). The BOD biodegradation value (%) of each biomass plastic relative to cellulose was calculated by calculating the BOD biodegradation value (%) using formula (i) and dividing it by the decomposition value of cellulose evaluated under the same conditions. Three samples were used, and the average value was used.

[0092] [2] Mechanical Properties (1) Preparation of Molded Articles In the examples and comparative examples, molded articles were used to evaluate the physical properties of the derivatives. Molding was performed by setting the cylinder temperature at 190 to 230°C, the mold temperature at 65°C, and the dwell pressure at 100 MPa. The molding machine used was a HAAKE MiniJet II manufactured by Thermo Electron Corporation.

[0093] (2) Evaluation of Physical Properties The following evaluations were carried out for the above-mentioned molded body. <Charpy Impact Test> A Charpy impact test was carried out in accordance with JIS K7111-1 (notched: Type A (notch cutter tip R 0.25 mm)) using an evaluation sample having the shape of JIS K 7162 test piece 1A.

[0094] <Flexural Strength, Flexural Modulus, and Breaking Strain> A bending test was carried out in accordance with JIS K7171 to measure the flexural strength, flexural modulus, and breaking strain.

[0095] <Thermoplasticity (MFR)> Using a Takashita flow tester (manufactured by Shimadzu Corporation, product name: CFT-500D), MFR was measured in accordance with JIS 7210:1990 under the conditions of a temperature of 210°C, a load of 5 kg, a die of 2 mmφ×10 mm (hole diameter 2 mm, hole length 10 mm), and a preheat time of 2 minutes (the time from the time the sample was filled into the cylinder and the piston was inserted until the load was applied).

[0096] <Glass Transition Temperature (Tg)> The glass transition point was determined by differential scanning calorimetry (DSC) under the following conditions. The measuring devices used were an EXSTAR2000 and DSC6200 manufactured by Seiko Instruments Inc. The derivative was heated from 20°C to 200°C at 10°C / min, and then rapidly cooled from 200°C to -30°C at 50°C / min. The glass transition point (Tg) of the derivative was then measured when the temperature was raised from -30°C to 200°C at 20°C / min.

[0097] <Molecular Weight of Polysaccharides> (Degree of Polymerization of Cellulose) The degree of polymerization of cellulose (before the introduction of long-chain components and short-chain components) was calculated by measuring the intrinsic viscosity number [η] in accordance with JIS P8215 and using the following formula: [η] = 1.67 × DP where "DP" represents the degree of polymerization. ０．７１ (GPC measurement conditions for paramylon) The weight-average molecular weight of paramylon was measured under the following conditions. Column: PLgel 20 μm MIXED-A (product name, manufactured by Agilent Technologies, Inc.) Eluent: dimethylacetamide (DMAc) solution (0.1 M LiCl) Flow rate: 0.5 mL / min Detector: RI (differential refractive index) (RI-71 type 201 (16X) manufactured by Tosoh Corporation) Temperature: 23.0° C. Standard sample: Pullulan standard

[0098] (Synthesis Example 1) Synthesis of Paramylon Derivative P1 (1) 50 g of paramylon (weight-average molecular weight (Mw) 432,000) was added to a mixed solvent of 421 mL of N-methylpyrrolidone and 79 mL of pyridine and dispersed, followed by stirring overnight at room temperature under a nitrogen atmosphere. (2) After cooling the dispersion obtained in (1) to -4°C, 54.0 g of premixed hexanoyl chloride and 31.5 g of acetyl chloride were added to the dispersion in (1) while maintaining the temperature below 10°C. The mixture was heated to 90°C and then stirred for 4 hours with heating. (3) The reaction solution was then cooled to 65°C, and 250 mL of methanol was added dropwise and stirred for approximately 30 minutes. 300 mL of water was then added to precipitate the product. The product was collected by suction filtration, washed five times with 450 mL of a methanol / water mixture (5 / 1 v / v), and vacuum dried at 105°C for 5 hours to obtain paramylon acetate hexanate (yield: 91 g (97%)). The resulting paramylon acetate hexanate (paramylon derivative P1) had a DSHe (degree of substitution with long-chain components) of 1.04 and a DSAc (degree of substitution with short-chain components) of 0.99.

[0099] (Synthesis Example 2) Synthesis of Paramylon Derivative P2 Paramylon derivative P2 was obtained in the same manner as in Synthesis Example 1, except that 49.8 g of hexanoyl chloride and 33.9 g of acetyl chloride were used (yield: 91 g (94%)). The resulting paramylon acetate hexanate (paramylon derivative P2) had a DSHe (degree of substitution with long-chain components) of 1.20 and a DSAc (degree of substitution with short-chain components) of 0.93.

[0100] (Synthesis Example 3) Synthesis of Paramylon Derivative P3 Paramylon derivative P3 was obtained in the same manner as in Synthesis Example 1, except that 57.3 g of hexanoyl chloride and 33.4 g of acetyl chloride were used (yield: 93 g (97%)). The resulting paramylon acetate hexanate (paramylon derivative P3) had a DSHe (degree of substitution with long-chain components) of 1.23 and a DSAc (degree of substitution with short-chain components) of 0.97.

[0101] (Synthesis Example 4) Synthesis of Paramylon Derivative P4 (1) 500 g of paramylon (weight-average molecular weight (Mw) 461,000) and 5.0 kg of 7% aqueous hydrochloric acid were added to a reactor and stirred at 90°C for 4 hours. The reaction solution was then returned to room temperature. The product was collected by suction filtration, washed five times with 5.0 kg of water, and the washed solid was vacuum-dried at 105°C for 5 hours to obtain paramylon 1 (yield: 309 g (62% yield)). The weight-average molecular weight (Mw) of paramylon 1 was 148,000. 50 g of paramylon 1 was dispersed in a mixed solvent of 421 mL of N-methylpyrrolidone and 79 mL of pyridine, and the mixture was stirred overnight at room temperature under a nitrogen atmosphere. (2) After cooling the dispersion obtained in (1) to -4 ° C, 57.3 g of premixed hexanoyl chloride and 33.4 g of acetyl chloride were added to the dispersion in (1) while maintaining the temperature below 10 ° C., and the mixture was heated to 90 ° C. and stirred for 4 hours. (3) The reaction solution was then cooled to 65 ° C., and 210 mL of water was added to precipitate the product. The product was collected by suction filtration, washed five times with 450 mL of a methanol / water mixture (5 / 1 v / v), and vacuum dried at 105 ° C. for 5 hours to obtain paramylon acetate hexanate (yield: 100 g (100%)). The DSHe (degree of substitution by long-chain components) of the resulting paramylon acetate hexanate (paramylon derivative P4) was 1.21, and the DSAc (degree of substitution by short-chain components) was 1.07.

[0102] (Synthesis Example 5) Synthesis of Paramylon Derivative P5 Paramylon derivative P5 was obtained in the same manner as in Synthesis Example 1, except that 33.2 g of hexanoyl chloride and 38.7 g of acetyl chloride were used (yield: 80 g (97%)). The resulting paramylon acetate hexanate (paramylon derivative P5) had a DSHe (degree of substitution with long-chain components) of 0.59 and a DSAc (degree of substitution with short-chain components) of 1.07.

[0103] (Synthesis Example 6) Synthesis of Paramylon Derivative P6 Paramylon derivative P6 was obtained in the same manner as in Synthesis Example 2, except that 57.3 g of hexanoyl chloride and 36.3 g of acetyl chloride were used (yield: 101 g (96%)). The resulting paramylon acetate hexanate (paramylon derivative P6) had a DSHe (degree of substitution with long-chain components) of 1.31 and a DSAc (degree of substitution with short-chain components) of 1.17.

[0104] (Synthesis Example 10) Synthesis of Paramylon Derivative P7 Paramylon derivative P7 was obtained in the same manner as in Synthesis Example 1, except that 37.4 g of hexanoyl chloride and 43.6 g of acetyl chloride were used (yield: 89.0 g (96%)). The resulting paramylon acetate hexanate (paramylon derivative P7) had a DSHe (degree of substitution with long-chain components) of 0.80 and a DSAc (degree of substitution with short-chain components) of 1.42.

[0105] (Synthesis Example 11) Synthesis of Paramylon Derivative P8 Paramylon derivative P8 was obtained in the same manner as in Synthesis Example 1, except that 66.4 g of hexanoyl chloride and 19.4 g of acetyl chloride were used (yield: 74.0 g (76%)). The resulting paramylon acetate hexanate (paramylon derivative P8) had a DSHe (degree of substitution with long-chain components) of 1.33 and a DSAc (degree of substitution with short-chain components) of 0.60.

[0106] (Synthesis Example 12) Synthesis of Paramylon Derivative P9 Paramylon derivative P8 was obtained in the same manner as in Synthesis Example 1, except that 33.2 g of hexanoyl chloride and 43.6 g of acetyl chloride were used (yield: 84.2 g (96%)). The resulting paramylon acetate hexanate (paramylon derivative P8) had a DSHe (degree of substitution with long-chain components) of 0.72 and a DSAc (degree of substitution with short-chain components) of 1.23.

[0107] (Synthesis Example 7) Synthesis of Cellulose Derivative C1 (1) 100 g of cellulose (degree of polymerization 560) was added to a mixed solvent of 1.14 L of N-methylpyrrolidone and 159 mL of pyridine and dispersed. The mixture was stirred overnight at room temperature under a nitrogen atmosphere to obtain a dispersion. (2) After cooling the dispersion obtained in (1) to -4 ° C, 166 g of premixed hexanoyl chloride and 48.4 g of acetyl chloride were added to the dispersion in (1) while maintaining the temperature below 10 ° C., and the mixture was heated to 90 ° C. and then stirred for 4 hours while heating. (3) The reaction solution was then cooled to 65 ° C., and 750 mL of methanol was added dropwise. After stirring for about 30 minutes, 333 mL of water was added to precipitate the product. The product was recovered by suction filtration, washed five times with 1.30 L of methanol, and then vacuum dried at 105 ° C. for 5 hours to obtain a cellulose-based resin (yield: 203 g (yield: 92%)). The resulting cellulose acetate hexanate (cellulose derivative C1) had a DSHe (degree of substitution with long chain components) of 1.64 and a DSAc (degree of substitution with short chain components) of 0.87.

[0108] (Synthesis Example 8) Synthesis of Cellulose Derivative C2 Cellulose derivative C2 was obtained in the same manner as in Synthesis Example 7, except that 125 g of hexanoyl chloride and 72.6 g of acetyl chloride were used (yield: 186 g (90%)). The resulting cellulose acetate hexanate (cellulose derivative C2) had a DSHe (degree of substitution with long-chain components) of 1.20 and a DSAc (degree of substitution with short-chain components) of 1.33.

[0109] (Synthesis Example 9) Synthesis of Cellulose Derivative C3 Cellulose derivative C3 was obtained (yield: 178 g (94%)) in the same manner as in Synthesis Example 7, except that the amounts of hexanoyl chloride and acetyl chloride were 41.5 g and 145 g, respectively. The resulting cellulose acetate hexanate (cellulose derivative C3) had a DSHe (degree of substitution with long-chain components) of 0.31 and a DSAc (degree of substitution with short-chain components) of 2.73.

[0110] Tables 2 and 3 show the substitution degrees (DS) of the long-chain component (hexanoyl group) and the short-chain component (acetyl group) of the polysaccharide derivatives obtained in Synthesis Examples 1 to 9. Ｌo ・DS ｓｈ ) is shown.

[0111]

[0112]

[0113] Test Example 1: Production of biomass plastic of paramylon derivative P1 and polybutylene succinate adipate (PBSA) in a ratio of 80:20 24.0 g of paramylon derivative P1 (pellets) and 6.0 g of PBSA (pellets) were placed in a bag and mixed in advance, then melt-kneaded at 200°C using a twin-screw kneader (a small kneader, the same applies to all of the following Examples and Comparative Examples) to produce pellets. The resulting pellets were molded using an injection molding machine, and their physical properties were evaluated.

[0114] Test Example 2: Production of a biomass plastic of paramylon derivative P1 and polybutylene succinate adipate (PBSA) at a ratio of 90:10 27.0 g of paramylon derivative P1 (pellets) and 3.0 g of PBSA (pellets) were placed in a bag and mixed in advance, then mixed in a twin-screw mixer at 200° C. to produce pellets. The resulting pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0115] Test Example 3: Production of biomass plastic of paramylon derivative P1 30.0 g of the paramylon derivative P1 was mixed using a twin-screw kneader at 200° C. to prepare pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0116] Test Example 4: Production of biomass plastic of paramylon derivative P4 30.0 g of the paramylon derivative P4 was mixed using a twin-screw kneader at 200° C. to prepare pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0117] Test Example 5: Production of biomass plastic of paramylon derivative P6 30.0 g of the paramylon derivative P6 was mixed using a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0118] Test Example 6: Production of biomass plastic of paramylon derivative P2 and polybutylene succinate adipate (PBSA) at a ratio of 80:20 24.0 g (pellets) of paramylon derivative P2 and 6.0 g (pellets) of PBSA were placed in a bag and mixed in advance, then mixed in a twin-screw mixer at 200° C. to produce pellets. The resulting pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0119] Test Example 7: Production of biomass plastic of paramylon derivative P2 30.0 g of the paramylon derivative P2 was mixed using a twin-screw kneader at 200° C. to prepare pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0120] Test Example 8: Production of a biomass plastic of paramylon derivative P3 and polybutylene succinate adipate (PBSA) in a ratio of 83:17 24.9 g (pellets) of paramylon derivative P3 and 5.1 g (pellets) of PBSA were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200°C to produce pellets. The resulting pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0121] Test Example 9: Production of biomass plastic of paramylon derivative P3 and polybutylene succinate adipate (PBSA) in a ratio of 86:14 25.8 g (pellets) of paramylon derivative P3 and 4.2 g (pellets) of PBSA were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The resulting pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0122] Test Example 10: Production of a 90:10 biomass plastic of paramylon derivative P3 and polybutylene succinate adipate (PBSA) 27.0 g (pellets) of paramylon derivative P3 and 3.0 g (pellets) of PBSA were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The resulting pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0123] Test Example 11: Production of biomass plastic of paramylon derivative P3 30.0 g of the paramylon derivative P3 was mixed using a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0124] Test Example 12: Production of biomass plastic of paramylon derivative P5 and polybutylene succinate adipate (PBSA) at a ratio of 70:30 21.0 g (pellets) of paramylon derivative P5 and 9.0 g (pellets) of PBSA were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 225° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0125] Test Example 13: Production of biomass plastic of paramylon derivative P5 and polybutylene succinate adipate (PBSA) at a ratio of 80:20 24.0 g (pellets) of paramylon derivative P5 and 6.0 g (pellets) of PBSA were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 225°C to produce pellets. The resulting pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0126] Test Example 14: Production of biomass plastic of paramylon derivative P5 30.0 g of the paramylon derivative P5 was mixed using a twin-screw kneader at 225° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0127] Test Example 15: Production of a biomass plastic of cellulose derivative C1 and polybutylene succinate adipate (PBSA) at a ratio of 80:20 24.0 g of cellulose derivative C1 (pellets) and 6.0 g of PBSA (pellets) were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 220° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and their physical properties were evaluated.

[0128] Test Example 16: Production of biomass plastic from cellulose derivative C1 30.0 g of the cellulose derivative C1 was mixed using a twin-screw kneader at 220° C. to prepare pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0129] Test Example 17: Production of a biomass plastic of cellulose derivative C2 and polybutylene succinate adipate (PBSA) at a ratio of 80:20 24.0 g of cellulose derivative C2 (pellets) and 6.0 g of PBSA (pellets) were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 220° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and their physical properties were evaluated.

[0130] Test Example 18 Production of Biomass Plastic from Cellulose Derivative C2 30.0 g of the cellulose derivative C2 was mixed using a twin-screw kneader at 220° C. to prepare pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0131] Test Example 19: Production of a biomass plastic of cellulose derivative C3 and polybutylene succinate adipate (PBSA) at a ratio of 80:20 24.0 g of cellulose derivative C3 (pellets) and 6.0 g of PBSA (pellets) were placed in a bag and mixed in advance, and then mixed using a twin-screw kneader at 230° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and their physical properties were evaluated.

[0132] Test Example 20 Production of Cellulose Derivative C3 30.0 g of the cellulose derivative C3 was mixed using a twin-screw kneader at 230° C. to prepare pellets, which were then molded using an injection molding machine and evaluated for physical properties.

[0133] Test Example 21: Production of biomass plastic composed of paramylon derivative P2 and polycaprolactone (PCL) at a ratio of 90:10 27.0 g (pellets) of paramylon derivative P2 and 3.0 g (pellets) of PCL were placed in a bag and mixed in advance, then mixed in a twin-screw mixer at 200° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0134] Test Example 22: Production of a biomass plastic of paramylon derivative P2 and polycaprolactone (PCL) at a ratio of 95:5 28.5 g (pellets) of paramylon derivative P2 and 1.5 g (pellets) of PCL were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0135] Test Example 23: Production of biomass plastic of paramylon derivative P3 and polycaprolactone (PCL) at a ratio of 80:20 24.0 g (pellets) of paramylon derivative P3 and 6.0 g (pellets) of PCL were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0136] Test Example 24: Production of biomass plastic of paramylon derivative P3 and polybutylene adipate terephthalate (PBAT) at a ratio of 80:20 24.0 g (pellets) of paramylon derivative P3 and 6.0 g (pellets) of PBAT were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200°C to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0137] Test Example 25: Production of biomass plastic of paramylon derivative P3 and polylactic acid (PLA) at a ratio of 80:20 24.0 g (pellets) of paramylon derivative P3 and 6.0 g (pellets) of PLA were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0138] Test Example 26: Production of biomass plastic of paramylon derivative P7 30.0 g of the paramylon derivative P7 was mixed using a twin-screw kneader at 225° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0139] Test Example 27: Production of a biomass plastic of paramylon derivative P7 and polycaprolactone (PCL) at a ratio of 90:10 27.0 g (pellets) of paramylon derivative P7 and 3.0 g (pellets) of PCL were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0140] Test Example 28: Production of biomass plastic of paramylon derivative P8 30.0 g of the paramylon derivative P8 was mixed using a twin-screw kneader at 225° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0141] Test Example 29: Production of a 90:10 biomass plastic of paramylon derivative P8 and polycaprolactone (PCL) 27.0 g (pellets) of paramylon derivative P8 and 3.0 g (pellets) of PCL were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0142] Test Example 30: Production of biomass plastic of paramylon derivative P9 30.0 g of the paramylon derivative P9 was mixed using a twin-screw kneader at 225° C. to produce pellets. The obtained pellets were molded using an injection molding machine, and the physical properties were evaluated.

[0143] Test Example 31: Production of biomass plastic of paramylon derivative P9 and polycaprolactone (PCL) at a ratio of 70:30 21.0 g (pellets) of paramylon derivative P9 and 9.0 g (pellets) of PCL were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0144] Test Example 32: Production of a 50:50 biomass plastic of paramylon derivative P9 and polycaprolactone (PCL) 15.0 g of paramylon derivative P9 (pellets) and 15.0 g of PCL (pellets) were placed in a bag and mixed in advance, then mixed in a twin-screw kneader at 200° C. to produce pellets. The obtained pellets were molded in an injection molding machine, and their physical properties were evaluated.

[0145] The physical properties of the biomass plastics of each test example were measured and evaluated. The results are shown in Tables 4 to 7.

[0146]

[0147] When paramylon derivatives with a relatively low degree of substitution (P1 to P4) were used alone, the Charpy impact strength was low (Test Examples 3, 4, 7, and 11). Therefore, when the degree of substitution of the paramylon derivative was increased (P6), the Charpy impact strength increased, but marine biodegradability was not achieved (Test Example 5). Thus, it was difficult to achieve marine biodegradability, mechanical strength, and thermoplasticity simultaneously with paramylon derivatives alone. Therefore, in this disclosure, we attempted to alloy a paramylon derivative with a relatively low degree of substitution with a biodegradable resin (PBSA).

[0148] Compared with Test Example 3, which contained only the paramylon derivative (P1), Test Examples 1 and 2, which compounded the paramylon derivative (P1) with a biodegradable resin (PBSA), showed improved Charpy impact strength and thermoplasticity, while maintaining marine biodegradability. Similar effects were obtained when P2 and P3 were used as paramylon derivatives (Test Examples 6 to 11).

[0149] It was found that when the content of the paramylon derivative is 70 to 90 mass% and the content of the biodegradable resin is 10 to 30 mass% relative to the total content of the paramylon derivative and biodegradable resin, which is 100 mass%, marine biodegradability and good mechanical strength and thermoplasticity can be achieved at the same time.

[0150] Furthermore, if the degree of long-chain substitution of the paramylon derivative is too low (P5), sufficient mechanical strength cannot be obtained even when alloyed with a biodegradable resin (Test Examples 12 to 14). It was found that the degree of long-chain substitution of the paramylon derivative is preferably 0.6 or more, and the total degree of substitution is preferably 1.6 to 2.3.

[0151]

[0152] The Charpy impact strength was low when only the paramylon derivatives (P7 to P9) with a relatively low degree of substitution were used (Test Examples 26, 28, and 30).

[0153] Therefore, we attempted to alloy a paramylon derivative with a biodegradable resin (PCL) using a paramylon derivative with a relatively low degree of substitution. It was found that in Test Examples 27, 29, and 31, Charpy impact strength improved and marine biodegradability was maintained. It was found that when the paramylon derivative content was 70-90% by mass and the biodegradable resin content was 10-30% by mass, relative to a total content of the paramylon derivative and biodegradable resin of 100% by mass, marine biodegradability was achieved alongside good mechanical strength and thermoplasticity.

[0154] On the other hand, in Test Example 32, in which 50% biodegradable resin (PCL) was added, marine biodegradability was maintained, but the molded body became cloudy and the Charpy impact strength decreased. It is thought that the increase in the blending ratio of the biodegradable resin promoted crystallization of the biodegradable resin, which is why the Charpy impact strength decreased.

[0155]

[0156] When only a cellulose derivative with a relatively low degree of substitution (C1 or C2) was used, the Charpy impact strength was low (Test Examples 16 and 18). Therefore, when the degree of substitution of the cellulose derivative was increased (C3), thermoplasticity was not obtained (Test Example 20). Thus, it was difficult to achieve both marine biodegradability, mechanical strength, and thermoplasticity using a cellulose derivative alone. Therefore, in this disclosure, an attempt was made to alloy a cellulose derivative with a relatively low degree of substitution with a biodegradable resin.

[0157] It was found that Test Example 17, in which the cellulose derivative (C2) was compounded with a biodegradable resin, had improved Charpy impact strength and thermoplasticity compared to Test Example 18, which contained only the cellulose derivative (C2). Similar effects were also obtained when C1 was used as the cellulose derivative (Test Examples 15 and 16).

[0158] It was found that when the cellulose derivative content is 70 to 90 mass% and the biodegradable resin content is 10 to 30 mass% relative to the total content of the cellulose derivative and biodegradable resin (100 mass%), marine biodegradability and good mechanical strength and thermoplasticity can be achieved simultaneously.

[0159] If the degree of short-chain substitution of the cellulose derivative was too high (C3), sufficient mechanical strength and thermoplasticity could not be obtained even when alloyed with a biodegradable resin (Test Examples 19 and 20). When a cellulose derivative with a total degree of substitution of less than 2.4 was used, the thermoplasticity decreased and alloying was not possible. It was found that the degree of long-chain substitution of 0.6 or more is preferable, and the total degree of substitution is preferably 2.4 to 2.6.

[0160]

[0161] Comparisons of Test Example 7 with Test Examples 6, 21, and 22, and comparisons of Test Example 11 with Test Example 23, confirmed that the Charpy impact strength and thermoplasticity were improved by using 10 to 30 mass% of polybutylene succinate adipate (PBSA) or polycaprolactone (PCL) as the biodegradable resin. On the other hand, comparisons of Test Example 11 with Test Examples 24 and 25 confirmed that the Charpy impact strength was not improved when polybutylene adipate terephthalate (PBAT) or polylactic acid (PLA) was used as the biodegradable resin.

[0162] Although the present disclosure has been described above with reference to the embodiments, the present disclosure is not limited to the above-described embodiments. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present disclosure within the scope of the present disclosure. Furthermore, each embodiment can be combined with other embodiments as appropriate.

[0163] (Appendix 1) A cellulose derivative in which hydrogen atoms of hydroxyl groups of cellulose are substituted with long-chain components which are saturated aliphatic acyl groups having 6 to 18 carbon atoms and short-chain components which are acyl groups having 2 or 3 carbon atoms, and the degree of substitution by the long-chain components (DS) Ｌｏ ) and the degree of substitution by the short chain component (DS Ｓｈ ) is in the range of 2.4 to 2.6, and the degree of substitution with the long chain component (DS Ｌｏ A polysaccharide-based biomass plastic comprising: a cellulose derivative having a degree of substitution (DS) of 0.6 or more; and a biodegradable resin which is one or more selected from the group consisting of polybutylene succinate, polybutylene succinate adipate, and polycaprolactone, wherein the content of the cellulose derivative is 70 to 90% by mass relative to 100% by mass of the total content of the cellulose derivative and the biodegradable resin, and the content of the biodegradable resin is 10 to 30% by mass relative to 100% by mass of the total content of the cellulose derivative and the biodegradable resin. (Appendix 2) A paramylon derivative in which hydrogen atoms of hydroxy groups of paramylon are substituted with a long-chain component which is a saturated aliphatic acyl group having 6 to 18 carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms, and wherein the degree of substitution (DS) with the long-chain component is 0.6 or more; and a biodegradable resin which is one or more selected from the group consisting of polybutylene succinate, polybutylene succinate adipate, and polycaprolactone, wherein the content of the cellulose derivative is 70 to 90% by mass relative to 100% by mass of the total content of the cellulose derivative and the biodegradable resin, and the content of the biodegradable resin is 10 to 30% by mass relative to 100% by mass of the total content of the cellulose derivative and the biodegradable resin. Ｌｏ ) and the degree of substitution by the short chain component (DS Ｓｈ ) is in the range of 1.6 to 2.3, and the degree of substitution with the long chain component (DS Ｌｏ) is 0.6 or more, and a biodegradable resin which is one or more selected from the group consisting of polybutylene succinate, polybutylene succinate adipate, and polycaprolactone, wherein the content of the paramylon derivative is 70 to 90 mass% relative to 100 mass% of the total content of the paramylon derivative and the biodegradable resin, and the content of the biodegradable resin is 10 to 30 mass% relative to 100 mass% of the total content of the paramylon derivative and the biodegradable resin. (Appendix 3) The polysaccharide-based biomass plastic according to Appendices 1 or 2, wherein the long-chain component is a hexanoyl group. (Appendix 4) The polysaccharide-based biomass plastic according to any of the preceding Appendices, wherein the short-chain component is an acetyl group. (Appendix 5) The polysaccharide-based biomass plastic according to any one of the preceding appendices, which has a biodegradation value (relative to cellulose) of 10% or more after 3 months in a BOD test using seawater. (Appendix 6) The Charpy impact strength is 5 kJ / m ２ The polysaccharide-based biomass plastic according to any of the preceding appendices. (Appendix 7) A molding resin composition comprising the polysaccharide-based biomass plastic according to any of the preceding appendices. (Appendix 8) A molded body formed using the molding resin composition according to Appendix 7. (Appendix 9) A method for producing a polysaccharide-based biomass plastic, comprising the steps of: reacting cellulose or paramylon dispersed in a solvent with: a short-chain acylating agent which is one or more selected from the group consisting of fatty acid halides and acid anhydrides having 2 or 3 carbon atoms; and a long-chain acylating agent which is one or more selected from the group consisting of saturated fatty acid halides and acid anhydrides having 6 to 18 carbon atoms, under heating, in the presence of an acid scavenger component to acylate the hydroxy groups of the cellulose or paramylon, thereby preparing a cellulose derivative or paramylon derivative; and mixing the cellulose derivative or paramylon derivative with a biodegradable resin to form an alloy.

Claims

1. A cellulose derivative in which the hydrogen atoms of the hydroxyl groups of cellulose are substituted with long-chain components which are saturated aliphatic acyl groups having 6 to 18 carbon atoms and short-chain components which are acyl groups having 2 or 3 carbon atoms, and the degree of substitution by the long-chain components (DS) Ｌｏ ) and the degree of substitution by the short chain component (DS Ｓｈ ) is in the range of 2.4 to 2.6, and the degree of substitution with the long chain component (DS Ｌｏ ) is 0.6 or more, and a biodegradable resin which is one or more selected from the group consisting of polybutylene succinate, polybutylene succinate adipate, and polycaprolactone, wherein the content of the cellulose derivative is 70 to 90 mass% relative to 100 mass% of the total content of the cellulose derivative and the biodegradable resin, and the content of the biodegradable resin is 10 to 30 mass% relative to 100 mass% of the total content of the cellulose derivative and the biodegradable resin.

2. A paramylon derivative in which the hydrogen atoms of the hydroxyl groups of paramylon are substituted with a long-chain component which is a saturated aliphatic acyl group having 6 to 18 carbon atoms and a short-chain component which is an acyl group having 2 or 3 carbon atoms, and the degree of substitution by the long-chain component (DS) is Ｌｏ ) and the degree of substitution by the short chain component (DS Ｓｈ ) is in the range of 1.6 to 2.3, and the degree of substitution with the long chain component (DS Ｌｏ ) is 0.6 or more, and a biodegradable resin which is one or more selected from the group consisting of polybutylene succinate, polybutylene succinate adipate, and polycaprolactone, wherein the content of the paramylon derivative is 70 to 90% by mass relative to a total content of the paramylon derivative and the biodegradable resin of 100% by mass, and the content of the biodegradable resin is 10 to 30% by mass relative to a total content of the paramylon derivative and the biodegradable resin of 100% by mass.

3. The polysaccharide-based biomass plastic according to claim 1, wherein the long-chain component is a hexanoyl group.

4. The polysaccharide-based biomass plastic according to claim 1, wherein the short-chain component is an acetyl group.

5. The polysaccharide-based biomass plastic according to claim 1, which has a biodegradation value (relative to cellulose) of 10% or more after three months in a BOD test using seawater.

6. Charpy impact strength is 5 kJ / m ２ The polysaccharide-based biomass plastic according to claim 1 .

7. A molding resin composition comprising the polysaccharide-based biomass plastic according to claim 1.

8. A molded article formed using the molding resin composition according to claim 7.

9. The polysaccharide-based biomass plastic according to claim 2, wherein the long-chain component is a hexanoyl group.

10. The polysaccharide-based biomass plastic according to claim 2, wherein the short-chain component is an acetyl group.

11. The polysaccharide-based biomass plastic according to claim 2, which has a biodegradation value (relative to cellulose) of 10% or more after three months in a BOD test using seawater.

12. Charpy impact strength is 5 kJ / m ２ The polysaccharide-based biomass plastic according to claim 2 .

13. A molding resin composition comprising the polysaccharide-based biomass plastic according to claim 2.

14. A molded article formed using the molding resin composition according to claim 13.

15. A method for producing polysaccharide-based biomass plastics, comprising the steps of: reacting cellulose or paramylon dispersed in a solvent with one or more short-chain acylating agents selected from the group consisting of fatty acid halides and acid anhydrides having 2 or 3 carbon atoms, and one or more long-chain acylating agents selected from the group consisting of saturated fatty acid halides and acid anhydrides having 6 to 18 carbon atoms, in the presence of an acid scavenger component and under heating, thereby preparing a cellulose derivative or paramylon derivative by acylation of the hydroxyl groups of the cellulose or paramylon; and mixing the cellulose derivative or paramylon derivative with a biodegradable resin to form an alloy.

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