JP2009114265A - Biodegradable composition, biodegradable processed article such as strength member and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a processed biodegradable article having sufficient water resistance and strength and also having thermoplasticity. <P>SOLUTION: 15-75 mass% of starch, 5-50 mass% of protein, 3-50 mass% of cellulose fiber, 0.5-20 mass% of polyphenol and 0-5 mass% of sodium chloride are mixed together to give the respective contents as specified above. To 100 pts.mass of the resultant mixture, 10-100 pts.mass of water is added followed by well kneading by using, for example, a mixer. Next, to 100 pts.mass of a composition comprising starch, protein, cellulose fiber, polyphenol and sodium chloride, 15-100 pts.mass of polylactic acid is added followed by kneading under heating, and the resultant mixture is molded under heat to obtain an intermediate processed article of pellet form or a processed article usable, for example, as an enclosure of home electric appliances. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a biodegradable composition, a biodegradable processed product such as a strength member, and a method for producing the same.

  Many biodegradable resins and biodegradable compositions based on natural materials such as biodegradable resins such as polylactic acid and fatty acid polyester, and starch have been proposed. Biodegradable processed products using the degradable composition are provided.

  For example, Japanese Patent Laid-Open No. 7-17571 (Patent Document 1) discloses a biodegradable cushioning material which is formed by foaming with starch as a main component and adding vegetable fiber and / or protein. Japanese Unexamined Patent Publication No. 2005-119708 (Patent Document 2) discloses a biodegradable resin composition in which starch and polyol, monosaccharide or oligosaccharide, and protein are blended. Japanese Patent Laid-Open No. 5-320401 (Patent Document 3) discloses a biodegradable molded product obtained by blending wheat flour, starch, cellulose and the like and foaming and firing.

  However, when natural materials such as starch are used, the water resistance is often insufficient and the strength tends to be insufficient. For this reason, for example, JP-A-5-278738 (Patent Document 4), JP-A-5-57833 (Patent Document 5), and JP-A-2002-355932 (Patent Document 6) are molded from biodegradable compositions, respectively. A method of coating a water-resistant resin on the surface of a processed product is disclosed, but this method requires a new coating and increases the number of steps.

  On the other hand, as a biodegradable composition having improved impact resistance and heat resistance, for example, JP-A-6-248040 (Patent Document 7) discloses a composition comprising phenols, sugar and starch. ing. This composition is an application of resin formation by reaction of phenols with sugar. Japanese Patent Application Laid-Open No. 2004-137726 (Patent Document 8) discloses biodegradability comprising starch and tannin or polyphenol, and protein and mineral powder at the end of tannin or polyphenol and a divalent metal powder having a chelating mordanting effect. Compositions for gravel products are disclosed. However, this composition is one in which a condensation compound of a metal salt and a polyphenol is supported on starch, and a divalent metal salt is used. The tannins and polyphenols used here are condensed tannins such as tannins, tea tannins and bark tannins, which are suitable as substitutes for gravel, but condensed tannins and divalent metals. Because salt is used, the strength becomes too high and it is not suitable for processed products such as tableware. And since the metal salt is used, after decomposition | disassembly, these metals remain | survived and the possibility of having a bad influence on an environment was also considered. Furthermore, it does not have thermoplasticity.

  JP 2005-23262 (Patent Document 9) discloses cereals such as corn, dietary fibers such as weeds, main materials obtained by refining 100% natural materials such as sugar millet, and natural binders such as strawberries and konjac flour. A biodegradable composition is disclosed. However, the specific composition ratio is unknown, and it is unknown whether it can actually be manufactured as a product. Further, since this composition is composed only of natural materials such as grains, the quality of the finished molded product is not guaranteed, and it is unsuitable as an industrial product.

  Further, JP-A-9-500944 (Patent Document 10) discloses a biodegradable composition containing starch and protein, cellulose, phenol and tannin, tall oil and wax. However, since this composition contains tall oil or wax, there is a concern about exudation of wax or the like. Therefore, even if it is suitable for the production of woodwork, etc., it may cause an undesirable problem from the viewpoint of safety when applied to processed products such as tableware.

  On the other hand, as a biodegradable composition containing polylactic acid, for example, JP-A-2001-509526 (Patent Document 11) is composed of lignin, starch, protein and glycerol, and a lactic acid-based composition as a plasticizer. A composition incorporating a polymer is disclosed. In this composition, lignin modifies polysaccharides such as protein and starch, thereby obtaining stable thermoplasticity. However, since this biodegradable composition contains glycerol, there is a possibility that glycerol may elute, and when used in food containers, adverse effects due to glycerol are expected.

In JP-T-2002-512929 (Patent Document 12), starch and protein, cellulose, water, and metal salt hydrate are essential components, and polyvinyl alcohol, polylactic acid, polyesteramide, A thermoplastic composition using a natural biopolymer is disclosed. This composition can be manufactured by extrusion or injection molding of a product, and has a low density, a high compressive strength, and a tensile strength. However, since this composition uses metal salt hydrates such as CaCl ₂ · 2H ₂ O and AlK (SO 4) 2 · 12H ₂ O, these metals remain after being decomposed, adversely affecting the environment. The possibility was also considered.
JP 7-17571 A JP 2005-119708 A JP-A-5-320401 JP-A-5-278738 JP-A-5-57833 JP 2002-355932 A JP-A-6-248040 JP 2004-137726 A JP 2005-23262 A Japanese National Patent Publication No. 9-500924 Special table 2001-509526 gazette JP-T-2002-512929

  The present invention has been made in view of the above-described background art, and an object of the present invention is to provide a biodegradable processed product having sufficient water resistance and strength and having thermoplasticity.

  As a result of diligent efforts to solve the above-mentioned problems, the present inventors have found that a four-component system of starch, protein, cellulose fiber and polyphenols, and a composition to which sodium chloride is added if necessary, have water resistance and sufficient mechanical properties. Has been found to have the right strength. And by adding biodegradable plastics, such as polylactic acid, to this composition and improving it, still better thermoplasticity was obtained and it came to complete this invention.

  According to the present invention, a biodegradable processed product having sufficient water resistance and strength can be obtained, and a biodegradable composition that can be applied to a relatively strong product such as a housing of home appliances is provided. Is done. Moreover, since this composition has thermoplasticity, it can be provided as pellets, and so-called biodegradable plastic products that can be handled in the same manner as conventional thermoplastic resins can be provided.

  The biodegradable composition of the present invention comprises 15 to 75 mass% starch, 5 to 50 mass% protein, 3 to 50 mass% cellulose fiber, 0.5 to 20 mass% polyphenols and 0 to 5 mass%. It consists of 100 parts by weight of a composition consisting of 1% sodium chloride and 15-100 parts by weight of biodegradable plastic.

  The starch used in the present invention may be not only a starch derived from a natural product (natural starch), but also any chemically modified starch obtained by chemically treating natural starch and subjecting it to chemical modification. Can also be used.

  The natural starch is a starch obtained from various plants such as corn starch, potato starch, sweet potato starch, wheat starch, rice starch, tapioca starch, sorghum starch, and the origin plant is not limited. Further, the amylose and amylopectin contents contained in the starch are not particularly limited, and starch having a high amylose content such as high amylose corn starch may be used. In the present invention, not only a single starch but also two or more kinds of natural starches may be used.

  Chemically modified starch is obtained by introducing a substituent into the hydroxyl group of glucose constituting starch. The substituent is not particularly limited, and the type of natural starch that is the modified starch is not limited. As the chemically modified starch, for example, hydroxypropyl starch, carboxymethyl starch, acetylated high amylose starch, acetate starch, starch maleate, octenyl succinate starch, succinate starch, phthalate starch, hydroxypropyl high amylose starch, cross-linked starch, Examples include phosphate starch and hydroxypropyl distarch phosphate. These chemically modified starches are not limited to a single type, and two or more types may be mixed and used. The term “crosslinked starch” as used herein refers to those obtained by crosslinking starch molecules with various crosslinking agents such as phosphates, epichlorohydrin, phosphoric acid derivatives and the like.

  The protein used in the present invention may be either a plant-derived protein or an animal-derived protein, or a synthetic protein. Examples of plant-derived protein (plant protein) include proteins obtained from various beans and cereals such as soybean protein, wheat protein, and rice protein. Examples of animal-derived proteins (animal proteins) include proteins derived from various animals such as milk protein, birds, and fish. These proteins may be not only crude proteins that have been extracted but not purified, but also concentrated proteins that have been concentrated. For example, if it is plant-derived protein, soybean concentrated protein is exemplified, and if it is animal-derived protein, concentrated milk protein is exemplified. On the other hand, it may be a protein obtained by purifying a crude protein. Examples of plant-derived proteins include gluten, zein, hordein, avenin, and kafilin. Examples of animal-derived proteins include casein, albumin, collagen, gelatin, and keratin. Is done. These proteins can be used alone or in combination of two or more.

  The cellulose fiber used in the present invention may be either natural or artificial cellulose fiber. Naturally-derived cellulose fibers include various seeds such as seed coats of cereals such as rice husks, grass, wood, straw, sugar cane, cotton, leaves, corn peel and sugar cane obtained from sugar cane, newspapers, etc. Goods are illustrated. These cellulose fibers are used by drying straw or cereal seed coats, etc., then loosening them into fibers and cutting them into appropriate lengths. Cellulose fibers that can be used have a thickness of about 1 to 100 μm and a length of about 10 μm to 30 mm, and are appropriately determined depending on the use of the processed product, the required strength, and the like.

  The polyphenol used in the present invention may be a compound having a phenolic hydroxyl group in the compound, and may be any of a low molecular polyphenol having a molecular weight of about 100 to 1,000 and a higher molecular polyphenol. Examples include pyrogallol, gallic acid, tannin and the like, and one or more polyphenols are used. Tannins are largely divided into condensed tannins and soluble tannins (hydrolyzable tannins) typified by persimmon and tea tannins. In the present invention, soluble tannins that produce gallic acid or ellagic acid by hydrolysis are preferred. In order to keep the quality uniform, low molecular polyphenols such as pyrogallol and gallic acid obtained by hydrolyzing soluble tannin are preferably used. This is because these low molecular weight polyphenols are chemically single and can be used in stable quality.

  As biodegradable plastics used in the present invention, polylactic acid-based polymers such as polylactic acid and polyhydroxylactic acid, polyvinyl alcohol, polybutylene succinate, polybutylene succinate terephthalate, polyalkylene succinate such as polyethylene succinate, Examples include polyglycolic acid, polyhydroxybutyric acid, and polyhydroxyvaleric acid. Particularly in the present invention, polylactic acid-based polymers such as polylactic acid and polyhydroxylactic acid are preferably used. As this polymer, not only a homopolymer of lactic acid and hydroxylactic acid, but also a copolymer obtained by copolymerizing a lactic acid monomer, a monomer of hydroxylactic acid, or a lactide thereof with these other copolymerizable components may be used. Examples of other copolymerizable components include glycolic acid, 3-hydroxybutyric acid, hydroxycarboxylic acid such as 5-hydroxyvaleric acid or 6-hydroxycaproic acid, succinic acid, adipic acid, sebacic acid, glutaric acid, terephthalic acid Alternatively, dicarboxylic acids such as isophthalic acid, polyhydric alcohols typified by ethylene glycol, propanediol, octanediol, glycerin, sorbitan or polyethylene glycol, lactones typified by ε-caprolactone or δ-butyrolactone, and the like can be given. The lactic acid used may be either D-type lactic acid or L-type lactic acid, or a mixture thereof.

  The biodegradable composition of the present invention comprises starch, protein, cellulose fiber, polyphenols and biodegradable plastic as essential components, 15 to 75% by mass of starch, 5 to 50% by mass of protein, and 3 of cellulose fiber. The biodegradable plastic is contained in an amount of 15 to 100 parts by mass with respect to 100 parts by mass of the composition comprising -50% by mass and 0.5 to 20% by mass of polyphenols. Moreover, sodium chloride may be mix | blended with this. By blending sodium chloride, a so-called “waist” is obtained when making udon noodles, and a biodegradable processed product having strength (rigidity) can be obtained. When sodium chloride is blended, it is blended at 5% by mass or less in the composition excluding the biodegradable plastic.

  The biodegradable composition of the present invention has been found by blending a biodegradable plastic with a composition in which starch and protein, cellulose fiber, polyphenols, and sodium chloride are added if necessary. That is, a biodegradable plastic is added as an additive to a composition in which starch and protein, cellulose fiber, polyphenols, and sodium chloride as necessary are added, and imparts thermoplasticity to the composition. In addition, the strength of the biodegradable processed product obtained is increased. Therefore, as will be described in the following examples, a biodegradable plastic is blended with a composition exhibiting good mixing properties, pressability, and moldability. At this time, 15 parts by mass or more and 100 parts by mass or less of the biodegradable plastic is blended with respect to 100 parts by mass of the composition excluding the biodegradable plastic. When the amount is less than 15 parts by mass, sufficient kneading may not be performed or good moldability may not be obtained. In addition, improvement in strength and thermoplasticity may not be expected. On the other hand, although it can mix | blend exceeding 100 mass parts, the processed goods which have plasticity and intensity | strength sufficient practically with the compounding quantity of 100 mass parts or less are obtained.

  The base composition before blending the biodegradable plastic is based on a mixture of starch and protein, and it is important to blend cellulose fibers and polyphenols on this basis. If the polyphenols are less than 0.5% by mass, sufficient kneading (kneading) cannot be performed or molding becomes difficult. Even if the amount of polyphenols exceeds 20% by mass, the moldability deteriorates. Further, if the cellulose fiber is less than 3% by mass or exceeds 50% by mass, molding becomes impossible.

  In the above composition, the mass ratio of starch / protein is preferably 1 or more and 12 or less, more preferably 1 or more and 3 or less. For example, when the derived plant uses the same starch and protein, such as wheat starch and wheat protein, the mass ratio of starch and protein (starch / protein) can be 3 or more. If it is less than 5% by mass, the moldability becomes poor. If the starch to protein mass ratio exceeds 3 and the starch is increased, sufficient kneading may not be possible or the moldability tends to deteriorate. Therefore, if kneading is not possible or the moldability is poor, it is better to increase the amount of protein. Moreover, in the range where the mass ratio of starch to protein is 1 or more and 3 or less, moldability can be ensured by setting the amount of protein to 15 mass% or more, desirably 20 mass% or more. On the other hand, if the protein exceeds 50% by mass, the moldability by pressing tends to deteriorate.

  On the other hand, when the amount of cellulose fiber is larger than the amount of protein, flexibility is lost and the moldability is adversely affected. Therefore, it is preferable to reduce the amount of cellulose fiber as the mass ratio of starch and protein is increased. Specifically, when the starch / protein mass ratio exceeds 2, the blended amount of cellulose fibers is 30% by mass or less, and when the starch / protein mass ratio exceeds 1 and 2 or less, When the blending amount is 40% by mass or less and the starch / protein mass ratio is 1, the blending amount of the cellulose fiber is desirably 50% by mass or less. However, it goes without saying that, depending on the blending amount of the cellulose fiber and the polyphenols, good water resistance and strength can be obtained even outside this range.

  The biodegradable composition of the present invention contains starch, protein, cellulose fiber and polyphenols, biodegradable plastic and necessary sodium chloride as essential components, and in addition, biodegradable plastic is added as an additive. It is not necessary to add other plasticizers, softeners, and metal salts (except sodium salts). However, additives such as colorants and stabilizers for preventing thermal coloring can be blended as long as the physical properties such as strength and flexibility of the processed product of the present invention are not essentially changed.

  The biodegradable processed product of the present invention can be produced as follows. That is, components other than the biodegradable plastic are mixed well with water, and then the biodegradable plastic is added and further kneaded. That is, the components other than the above-described biodegradable plastic are mixed in a predetermined blending amount, and then added, and then sufficiently stirred and kneaded using a mixer or the like. At this time, it is not sufficient to mix each component and water, and it is preferable to knead to a hardness that is about the level of an earlobe, and preferably so-called noodle waist.

  In this case, the mixing ratio of water and the composition excluding the biodegradable plastic is 10 to 100 parts by weight of water, preferably 30 to 85 parts by weight of water with respect to 100 parts by weight of the composition. It is adjusted to such an extent that hardness is obtained. If the amount of water is less than 10 parts by mass, it becomes powdery and cannot be sufficiently kneaded. If the amount is more than 100 parts by mass, the amount of water is too soft and soft, and an appropriate hardness is often not obtained. .

  A biodegradable plastic is added to the above kneaded material and further kneaded. This kneading is performed under heating. By heating, the biodegradable plastic melts and fits well in the composition, leading to improved thermoplasticity and strength. Therefore, it is preferable to heat near the melting point of the biodegradable plastic used, preferably above the melting point. On the other hand, when the heating temperature is high, good moldability cannot be obtained.

  The obtained kneaded material is pressed into a desired shape as it is, for example. Moreover, the processed goods obtained from the composition of this invention have thermoplasticity. For this reason, it is also supplied as a so-called pellet-shaped intermediate processed product (primary processed product), and this intermediate processed product can be used as a final product. And it can also shape | mold into a predetermined shape with various shaping | molding methods, such as extrusion molding and injection molding, similarly to the case where a thermoplastic plastic is used. Also, heat treatment is performed during molding. By this heat treatment, sufficient strength and water resistance can be obtained. The processing temperature is preferably the same as or higher than the temperature during the kneading, for example, 150 to 220 ° C. for polylactic acid used in the examples.

  The biodegradable processed product thus obtained has a water resistance of about 30 days even when immersed in water. Further, this processed product has a tensile strength of 2 MPa or more and a bending strength of 30 MPa or more, and can be used for a housing of home appliances or furniture that requires strength. Since no oil, wax, or plasticizer is used, a resin-like product that does not ooze oil or wax and is excellent in safety to living bodies can be obtained. Moreover, since it is not a combination of a polyphenol such as tannin and a metal salt, the metal salt is not discharged by decomposition, and there is no concern about environmental pollution.

  However, since the processed product of the present invention has not only high strength but also sufficient water resistance, not only household appliance housings and furniture, but also tableware such as cups and dishes, chopsticks, forks, knives, spoons, etc. It can also be used for daily utensils such as tableware, lunch boxes, food containers such as so-called Tupperware (registered trademark), take-out packaging containers, pencil cases, underlays, and accessories. Also, if necessary, a water-resistant resin may be coated.

  Next, the present invention will be described in more detail based on the following examples. Needless to say, the present invention is not limited to the following examples.

  First, using the starch, protein, cellulose fiber, polyphenol and sodium chloride, the mixing / pressing property and moldability of the composition were evaluated.

  Corn starch (“Corn Starch” manufactured by Wako Pure Chemical Industries, Ltd.), wheat protein (“Fmerit A” manufactured by Nagata Sangyo Co., Ltd.), cellulose fiber (KC Flock # 100 mesh or # 200 manufactured by Nippon Paper Chemicals Co., Ltd.) ), Pyrogallol ("Pyrogallol powder" manufactured by Iwate Chemical Co., Ltd.), gallic acid ("gallic acid powder" manufactured by Iwate Chemical Co., Ltd.), sodium chloride ("Salt", Salt Business Center) Table 1 These were blended as shown in Table 2, a predetermined amount of water was added, and the mixture was kneaded at room temperature using a rotation and revolution mixer. This kneaded product was stretched into a sheet having a thickness of about 3 mm using a biaxial press, and formed into a cup having a thickness of 1 mm using a mold press at a temperature of 150 ° C. The mixing / pressability and moldability at this time were evaluated. The results are shown in Table 1-1 to Table 2-3. Tables 1-1 to 1-3 are evaluated by the blending amount of cellulose fiber, and Tables 2-1 to 2-3 are evaluated by the blending amount of polyphenol. The mixing / pressing property was evaluated based on whether the composition and water could be sufficiently kneaded, and the moldability was evaluated based on whether the press molding was satisfactory.

[Composition of polylactic acid]
Next, polylactic acid (polylactic acid manufactured by East Japan Resins Co., Ltd., melting point 150 ° C.) was added to the compositions of Test Nos. 34 and 39, which had good mixing / pressability and moldability in Tables 1 and 2 above. ) And the polylactic acid mixing property and heat pressability were examined. The results are shown in Table 3. As for the mixing property of polylactic acid, components other than polylactic acid and water were mixed uniformly at room temperature until the so-called waist was raised, then polylactic acid was added and kneaded well at a temperature of 160 ° C. After returning this kneaded material to room temperature, press molding was then performed at 200 ° C., and evaluation was made regarding the mixing property and the heat press property. The mixing property was evaluated based on whether or not it was sufficiently kneaded with polylactic acid, and the hot press property was evaluated based on whether or not the press molding was good. The results are shown in Table 3. Although not shown, according to differential thermal analysis, it was found that starch produced a heat endothermic reaction in the range of about 50 to 170 ° C, and wheat protein produced a heat endothermic reaction in the range of about 30 to 140 ° C. On the other hand, both turned over 180 ° C. and turned brown. Further, since the polylactic acid used has a melting point of 150 ° C., the mixing temperature was set to 160 ° C.

  As a result, by blending 15 parts by mass or more of polylactic acid with 100 parts by mass of starch, protein, polyphenol, cellulose fiber and, if necessary, sodium chloride added, a good heat press property can be obtained. (Test Nos. 203 to 207).

〔Strength test〕
In Table 3, the tensile strength and bending strength of the molded products of test numbers 203 to 207, which had good mixing properties and heat press properties, were measured. The results are shown in Table 4. As shown in Table 4, in these molded articles, a tensile strength of 2 MPa or more and a bending strength of 30 MPa or more were obtained. Moreover, when sodium chloride was mix | blended, the tensile strength and bending strength increased further, and the tensile strength of 3.5 MPa or more and the bending strength of 33 MPa or more were obtained.

(Water resistance evaluation)
Next, the water resistance of the molded products of Test Nos. 205 and 207 having good heat pressability was evaluated. When each molded product was immersed in room temperature water and allowed to stand at room temperature, the molded product of test number 205 was maintained for 30 days, the molded product of test number 207 was maintained for 40 days without swelling. As a result, it was confirmed that a molded product having practically water resistance was obtained in both cases. Further, it was confirmed that the processed products having test numbers other than these also had good strength and water resistance.

[Heat resistance evaluation]
The heat resistance of the molded article having the test number 204, which had good heat pressability and water resistance, was evaluated. The heat resistance was evaluated by thermomechanical analysis (TMA). TMA uses TMA120 manufactured by Seiko Instruments Inc. (atmosphere: nitrogen 200 mL / min, mode: compression, load: 500 mN), JIS K-7196 “Softening temperature test method by thermomechanical analysis of thermoplastic film and sheet” It went according to. The result is shown in FIG. As a result, slight softening was shown around 50 ° C. and abrupt softening was shown around 150 ° C., confirming heat resistance of 140 ° C. or higher.

  According to the present invention, it is possible to provide a biodegradable processed product having an unprecedented strength and water resistance. Since particularly high strength can be obtained, it can be applied to processed products that require strength, such as housings and furniture for home appliances. In addition, since the composition of the present invention is mostly starch, protein, cellulose fiber and biodegradable plastic, it is excellent in biodegradability, is easy to dispose and has little adverse effect on the environment. Further, since molding is possible without using a plasticizer, a biodegradable processed product excellent in safety without bleeding of the plasticizer is provided.

It is a chart which shows the softening point of the molded article which is an Example of this invention.

Claims (10)

Starch 15-75% by mass
5-50% by mass of protein
Cellulose fiber 3-50 mass%
Polyphenols 0.5-20% by mass
Sodium chloride 0-5% by mass
A biodegradable composition comprising 15 to 100 parts by mass of a biodegradable plastic with respect to 100 parts by mass of the composition.   The biodegradable composition according to claim 1, wherein the mass ratio of starch / protein in the composition excluding the biodegradable plastic is 1 or more and 12 or less.   The biodegradable composition according to claim 1, wherein the starch / protein mass ratio in the composition excluding the biodegradable plastic is 1 or more and 3 or less, and the protein is 15 mass% or more.   The biodegradable composition according to any one of claims 1 to 3, wherein the cellulose fiber is a natural plant fiber or an artificial cellulose fiber.   The biodegradable composition according to any one of claims 1 to 4, wherein the polyphenol is one or two of pyrogallol and gallic acid.   The biodegradable composition according to any one of claims 1 to 5, wherein the biodegradable plastic is a polylactic acid polymer.   A biodegradable processed product comprising the biodegradable composition according to any one of claims 1 to 6. Of the biodegradable composition according to any one of claims 1 to 6, a step of hydrating and mixing the components excluding the biodegradable plastic,
Adding a biodegradable plastic to the mixture under heating and kneading;
A method for producing a biodegradable processed product comprising a step of molding the kneaded composition under heating.   The method for producing a biodegradable processed product according to claim 8, wherein the biodegradable plastic is mixed and kneaded with a composition other than the biodegradable plastic at a temperature higher than the melting point of the biodegradable plastic. A step of adding to and mixing the components other than the biodegradable plastic in the biodegradable composition according to any one of claims 1 to 5,
Adding a biodegradable plastic to the mixture under heating and kneading;
An intermediate processed product obtained through a step of forming the kneaded composition into a predetermined shape under heating.

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