Molded article and method for manufacturing the same

Abstract

To provide a molded article that significantly improves flexibility (tensile and physical properties) while maintaining the high elastic moduli characteristic of polylactic acid.SOLUTION: A molded article comprises polylactic acid and citrate and has a tensile elasticity of 1.5 GPa or more and a tensile elongation of 100% or more. A method for producing a molded article includes a mixing step for heating and mixing polylactic acid and citrate at 130°C or lower, to obtain a polylactic acid composition, and a molding step for molding the polylactic acid composition obtained from the mixing step, to obtain a molded article.SELECTED DRAWING: None

Description

【Technical Field】 【0001】 The present invention relates to a molded body and a method for producing the same. 【Background Art】 【0002】 In recent years, petrochemical plastics are difficult to decompose in the natural environment after being discarded, which has become one of the causes of polluting the natural environment. In recent years, biodegradable plastics that can be decomposed in the natural environment after being discarded have attracted attention. As such biodegradable plastics, polylactic acid has been studied. 【0003】 Although polylactic acid has a high tensile elastic modulus (rigidity), it has properties such as low flexibility (tensile elongation and physical properties) and low impact resistance, and its applications have been limited. As a method for improving flexibility (tensile elongation and physical properties), a method of adding a plasticizer has been proposed (Patent Document 1). 【Prior Art Documents】 【Patent Documents】 【0004】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2020-117692 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0005】 However, when a plasticizer is added to polylactic acid, although the flexibility (tensile and physical properties) is improved, there is a problem that the elastic modulus is greatly reduced, so the applications are limited. The main object of the present technology is to provide a molded body that maintains a characteristic high elastic modulus of polylactic acid and greatly improves flexibility (tensile and physical properties). Furthermore, a further object of the present technology is to provide a molded body that is excellent in impact resistance in addition to high elastic modulus and excellent flexibility (tensile and physical properties). 【Means for Solving the Problems】 【0006】 The inventors have discovered that by incorporating polylactic acid and citrate ester, it is possible to provide a molded article that has a high tensile modulus while also exhibiting large tensile elongation. 【0007】 This technology is Polylactic acid and, Citric acid ester and, The present invention provides a molded article that contains [a certain material], has a tensile modulus of 1.5 GPa or more, and a tensile elongation of 100% or more. The citrate ester may be triethyl acetyl citrate. The citrate ester may be tributyl acetylcitrate. The citrate ester may include triethyl acetyl citrate and tributyl acetyl citrate. In the molded article relating to this technology, the dirt impact strength at 20°C may be 40g or more. In the molded article relating to this technology, the dirt impact strength at -10°C may be 30g or more. The molded product relating to this technology may be a sheet or a film. This technology is A kneading step in which polylactic acid and citrate ester are heated and kneaded at 130°C or below to obtain a polylactic acid composition, A molding step is performed to mold the polylactic acid composition obtained in the kneading step to obtain a molded body, The present invention provides a method for manufacturing a molded article comprising the above features. [Effects of the Invention] 【0008】 The present invention makes it possible to obtain a molded article that has high tensile modulus (rigidity) while also exhibiting large tensile elongation. The effects of the present invention are not necessarily limited to those described herein, but may be any of the effects described herein. [Brief explanation of the drawing] 【0009】 [Figure 1] This figure shows the tensile modulus of the sheets of Examples 1-3 and the tensile modulus of the sheets of Comparative Examples 1-2. [Figure 2] It is a diagram showing the tensile elastic modulus of the sheets of Examples 1 to 3 and the tensile elongation of the sheets of Comparative Examples 1 and 2. [Figure 3] It is a diagram showing the tensile strength of the sheets of Examples 1 to 3 and the tensile strength of the sheets of Comparative Examples 1 and 2. [Figure 4] It is a diagram showing the tensile elastic modulus of the sheet of Example 4 and the tensile elastic modulus of the sheets of Comparative Examples 3 to 5. [Figure 5] It is a diagram showing the tensile elongation of the sheet of Example 4 and the tensile elongation of the sheets of Comparative Examples 3 to 5. 【Mode for Carrying Out the Invention】 【0010】 Hereinafter, preferred embodiments for carrying out the present technology will be described. The embodiments described below show typical embodiments of the present technology, and the scope of the present technology is not limited to only these embodiments. 【0011】 The present technology will be described in the following order. 1. Description of the present technology 2. First Embodiment (1) Configuration of the molded body (2) Explanation of each component [[ID=第33]] (4) Manufacturing method of the molded body 3. Second Embodiment (1) Configuration of another example of the molded body (2) Explanation of each component (3) Physical properties (4) Manufacturing method of the molded body 4. Examples 【0012】 1. Description of the present technology 【0013】 The present inventors have found that by containing polylactic acid and a citrate ester described below, it is possible to improve the tensile elongation while suppressing a decrease in the tensile elastic modulus (rigidity) of the molded body. 【0014】 That is, the molded body according to the present technology contains polylactic acid and,​ Citric acid ester and, It contains [a specific material], has a tensile modulus of 1.5 GPa or higher, and a tensile elongation of 100% or higher. Furthermore, the method for manufacturing a molded article according to this technology is: A kneading step in which polylactic acid and citrate ester are heated and kneaded at 130°C or below to obtain a polylactic acid composition, A molding step is performed to mold the polylactic acid composition obtained in the kneading step to obtain a molded body, It is equipped with the above. The method for measuring the tensile modulus and tensile elongation will be explained below in 2.(3). 【0015】 2. First Embodiment (Example of a Molded Body) 【0016】 (1) Structure of the molded body 【0017】 [Molded body] 【0018】 The molded article according to this embodiment contains polylactic acid and citrate ester. 【0019】 In this embodiment, the polylactic acid content is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, relative to the mass of the molded article. Even more preferably 83% by mass or more. Furthermore, the polylactic acid content is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 88% by mass or less, relative to the mass of the molded article. 【0020】 In this embodiment, the citrate ester content is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more, relative to the mass of the molded article. By having a citrate ester content of preferably 5% by mass or more relative to the mass of the molded article, the kneading temperature of polylactic acid and citrate ester in a twin-screw extruder can be reduced to 130°C or below, thereby suppressing the vaporization of polylactic acid due to heating of the twin-screw extruder, and enabling the acquisition of tensile properties that maintain a high tensile modulus while also having good tensile elongation. Furthermore, the citrate ester content is preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 16% by mass or less, relative to the mass of the molded article. 【0021】 (2) Explanation of each component 【0022】 [Polylactic acid] 【0023】 The polylactic acid contained in the molded article according to this embodiment is a type of aliphatic polyester in which lactic acid is the basic unit and multiple lactic acid units are linked together to form a high molecular weight. Examples of such lactic acid include poly(L-lactic acid) whose structural unit is L-lactic acid, poly(D-lactic acid) whose structural unit is D-lactic acid, poly(DL-lactic acid) whose structural units are L-lactic acid and D-lactic acid, mixtures thereof, and random copolymers of L-lactic acid and D-lactic acid. 【0024】 The polylactic acid contained in the molded article according to this embodiment may be not only a polylactic acid homopolymer obtained by condensation polymerization of only the lactic acid component as the raw material monomer, but also a polylactic acid copolymer obtained by condensation polymerization of the lactic acid component and other monomer components copolymerizable with the lactic acid component as the raw material monomer. 【0025】 Polylactic acid can be produced by methods such as dehydration polymerization using only lactic acid as a raw material monomer with a suitable catalyst and initiator; dehydration polymerization using lactic acid as a raw material monomer and other monomer components copolymerizable with lactic acid as initiators; or synthesis using enzymatic reactions such as lipase. There are no particular limitations on the other monomer components copolymerizable with the lactic acid component, but examples include oxy acids, dihydric alcohols or polyhydric alcohols of trihydric or higher valencies, aromatic hydroxy compounds, dihydric carboxylic acids or polyhydric carboxylic acids of trihydric or higher valencies, and lactones. 【0026】 Examples of oxyacids include glycolic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxybenzoic acid, and hydroxyheptanoic acid, of which glycolic acid and hydroxycaproic acid are preferred. 【0027】 Examples of dihydric alcohols include ethylene glycol, propylene glycol, propanediol, butanediol, heptanediol, hexanediol, octanediol, nonanediol, decanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, and polytetramethylene glycol. Examples of polyhydric alcohols with a valency of three or higher include glycerin, trimethylolpropane, and pentaerythritol. 【0028】 Examples of aromatic hydroxy compounds include hydroquinone, resorcinol, and bisphenol A. 【0029】 Examples of divalent carboxylic acids include oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedionic acid, malonic acid, glutaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, bis(4-carboxyphenyl)methane, anthracenedicarboxylic acid, bis(4-carboxyphenyl) ether, and sodium 5-sulfoisophthalate. Examples of trivalent or polyvalent carboxylic acids include trimellitic acid and pyromellitic acid. 【0030】 Examples of lactones include caprolactone, valerolactone, propiolactone, undecalactone, and 1,5-oxepant-2-one. 【0031】 Furthermore, while other components of polylactic acid besides lactic acid can be copolymerized to the extent that the inherent biodegradability of polylactic acid is not impaired, the molecular ratio of these copolymers is preferably 20 mol% or less of the total constituent components, more preferably 0 to 10 mol%, and even more preferably in the range of 0 to 5 mol%. 【0032】 Polylactic acid has a melting point in the range of 160°C to 170°C and a glass transition temperature in the range of 60°C to 70°C. Furthermore, polylactic acid is biodegradable and compostable, making it an environmentally friendly material. 【0033】 The polylactic acid content is preferably 75% by mass or more, more preferably 80% by mass or more, and even more preferably 85% by mass or more, relative to the mass of the molded article. 【0034】 Furthermore, the polylactic acid content is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 88% by mass or less, relative to the mass of the molded article. 【0035】 [Citrate ester] 【0036】 Examples of citrate esters included in the molded article according to this embodiment include triethyl acetylcitrate (ATEC) and tributyl acetylcitrate (ATBC). Only one type of citrate ester may be used, or two or more types may be used in combination. In this embodiment, the citrate ester can function as a plasticizer. 【0037】 In this embodiment, from the viewpoint of lowering the temperature during extrusion such as twin-screw extrusion, the content of triethyl acetyl citrate (ATEC) is preferably 5% by mass or more, more preferably 8% by mass or more, and even more preferably 11% by mass or more, based on the mass of the molded article. 【0038】 In this embodiment, from the viewpoint of lowering the temperature during extrusion such as twin-screw extrusion, the content of triethyl acetyl citrate (ATEC) is preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 16% by mass or less, based on the mass of the molded article. 【0039】 In this embodiment, from the viewpoint of lowering the temperature during extrusion such as twin-screw extrusion, the content of tributyl acetyl citrate (ATBC) is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, based on the mass of the molded article. 【0040】 In this embodiment, from the viewpoint of lowering the temperature during extrusion such as twin-screw extrusion, the content of tributyl acetyl citrate (ATBC) is preferably 30% by mass or less, more preferably 28% by mass or less, and even more preferably 26% by mass or less, based on the mass of the molded article. 【0041】 The citrate ester contained in the molded article according to this embodiment may be a mixture of triethyl acetylcitrate (ATEC) and tributyl acetylcitrate (ATBC). In the case of a mixture of triethyl acetylcitrate (ATEC) and tributyl acetylcitrate (ATBC), the mixing ratio is preferably 12:1 to 12:5, more preferably 12:1.5 to 12:4, and even more preferably 12:2 to 12:3, for example, tributyl acetylcitrate (ATBC):triethyl acetylcitrate (ATEC). 【0042】 In this embodiment, from the viewpoint of lowering the temperature during extrusion such as twin-screw extrusion, the content ratio of the mixture of triethyl acetyl citrate (ATEC) and tributyl acetyl citrate (ATBC) is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, based on the mass of the molded article. 【0043】 In this embodiment, from the viewpoint of lowering the temperature during extrusion such as twin-screw extrusion, the content ratio of the mixture of triethyl acetyl citrate (ATEC) and tributyl acetyl citrate (ATBC) is preferably 40% by mass or less, more preferably 37% by mass or less, and even more preferably 35% by mass or less, relative to the mass of the molded article. 【0044】 (3) Physical properties 【0045】 [Tensile properties] 【0046】 The molded article according to this embodiment has a tensile modulus of elasticity of 1.5 GPa or more, preferably 1.7 GPa or more, and more preferably 2.0 GPa or more. Furthermore, there is no particular upper limit to the tensile modulus of elasticity, but it is preferably 3 GPa or less, more preferably 2.8 GPa or less, and even more preferably 2.5 GPa or less. 【0047】 The molded article according to this embodiment has a tensile elongation of 100% or more, preferably 120% or more, and more preferably 140% or more. Furthermore, there is no particular upper limit to the tensile elongation, but it is preferably 200% or less, more preferably 180% or less, and even more preferably 150% or less. 【0048】 The molded article according to this embodiment has a tensile strength, which is a tensile property, preferably 30 MPa or more, more preferably 40 MPa or more, and even more preferably 50 MPa or more. Furthermore, there is no particular upper limit to the tensile strength, but the tensile strength is preferably 60 MPa or less, more preferably 58 MPa or less, and even more preferably 55 MPa or less. 【0049】 The tensile properties described above can be measured, for example, in accordance with JIS K 7161. Polylactic acid and citrate esters, etc., are mixed as raw material components using a mixer (manufactured by LAB TECH Engineering Co., Ltd.) (rotation speed: 500 RPM, mixing time: 5 minutes). The resulting mixture is supplied to a twin-screw extruder (model PCM30, manufactured by Ikegai Co., Ltd.) and melt-kneaded (the melting temperature is appropriately set in the range of 115 to 155°C depending on the sample) to produce pellets. The pellets are hot-pressed at 180°C using a hot press (manufactured by LAB TECH Engineering Co., Ltd.) to produce sheets. The tensile properties are measured using a Tensilon universal tester (manufactured by A&D Co., Ltd.) in accordance with JIS K 7161. 【0050】 [Dirt impact strength] 【0051】 The molded article according to this embodiment preferably has a dirt impact strength of 40g or more, more preferably 50g or more, and even more preferably 60g or more at 20°C. Furthermore, there is no particular upper limit to the dirt impact strength at 20°C, but the dirt impact strength is preferably 95g or less, more preferably 80g or less, and even more preferably 70g or less. 【0052】 The molded article according to this embodiment preferably has a dirt impact strength of 30 g or more, more preferably 35 g or more, and even more preferably 40 g or more at -10°C. Furthermore, there is no particular upper limit to the dirt impact strength at -10°C, but the dirt impact strength is preferably 70 g or less, more preferably 60 g or less, and even more preferably 50 g or less. 【0053】 The above dart impact strength measurement can be performed, for example, in accordance with JIS K 7124 Method B. Polylactic acid and citrate ester, etc., as raw material components are mixed using a mixer (manufactured by LAB TECH Engineering Co., Ltd.) (rotation speed: 500 RPM, mixing time: 5 minutes). The resulting mixture is supplied to a twin-screw extruder (model PCM30, manufactured by Ikegai Co., Ltd.) and melt-kneaded (the melting temperature is appropriately set in the range of 115 to 155°C depending on the sample) to produce pellets. A sheet (thickness: approximately 0.4 mm) is produced by extruding the pellets into a sheet at 160°C using a single-screw extruder (manufactured by LAB TECH Engineering Co., Ltd.). A drop impact test is performed according to JIS K 7124 Method B. The test is performed at room temperature (20°C) and frozen (-10°C). The fracture rate of the sample sheet is visually confirmed, and the weight of the weight when the fracture rate of the sample sheet reaches 50% is defined as the dart impact strength. 【0054】 (4) Method for manufacturing molded articles 【0055】 The method for manufacturing a molded article according to this embodiment is: A kneading step in which polylactic acid and citrate ester are heated and kneaded at 130°C or below to obtain a polylactic acid composition, A molding step is performed to mold the polylactic acid composition obtained in the kneading step to obtain a molded body, It is equipped with. The molded article according to this embodiment can be manufactured by the method for manufacturing the molded article according to this embodiment. 【0056】 The following explains each step. 【0057】 [Mixing process] 【0058】 In the kneading process, polylactic acid and citrate ester are heated and kneaded at a temperature of 130°C or lower. In the kneading process, the raw materials such as polylactic acid and citrate ester may be mixed first. Alternatively, after the mixing of the raw materials is complete, the mixed raw materials may be heated and kneaded. The kneading process may be heated to a temperature at which the polylactic acid and citrate ester can melt. This temperature may be appropriately selected by those skilled in the art depending on the type of citrate ester used and its content. 【0059】 In the aforementioned kneading step, for example, if the citrate ester is triethyl acetyl citrate (ATEC), the kneading may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, the kneading may be carried out at a temperature of 130°C or lower, preferably 125°C or lower, and even more preferably 123°C or lower. 【0060】 In the aforementioned kneading step, for example, if the citrate ester is tributyl acetylcitrate (ATBC), the kneading may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, the kneading may be carried out at a temperature of 130°C or lower, preferably 125°C or lower, and even more preferably 123°C or lower. 【0061】 In the aforementioned kneading step, for example, if the citrate ester is a mixture of triethyl acetyl citrate (ATEC) and tributyl acetyl citrate (ATBC), the kneading may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, the kneading may be carried out at a temperature of 130°C or lower, preferably 125°C or lower, and more preferably 123°C or lower. 【0062】 Mixing of raw materials such as polylactic acid and citrate ester may be carried out using a mixer such as a high-temperature stirrer, Henschel mixer, tumbler mixer, Barber mixer, or kneader mixer. Heating and kneading of the mixed raw materials may be carried out using a single-screw kneading extruder or a twin-screw kneading extruder, for example. As these kneading extruders, devices known in the art may be used. Preferably, the kneading step includes at least heating and kneading treatment using a twin-screw kneading extruder. As the twin-screw kneading extruder, a twin-screw kneading extruder with co-rotating or opposite-rotating surfaces may be used. By performing the kneading treatment with a twin-screw kneading extruder, a polylactic acid composition, which is a kneaded product in which the raw materials are more uniformly dispersed, can be obtained. 【0063】 The polylactic acid composition obtained in the aforementioned kneading step may be used directly in the molding step without being pelletized. This eliminates the need for the pelletizing step. Furthermore, the polylactic acid composition obtained in the kneading step may be pelletized. The pelletized polylactic acid composition may then be subjected to a molding step. 【0064】 [Molding process] 【0065】 In the molding process, the polylactic acid composition obtained in the kneading process is molded to obtain a molded body. For example, the polylactic acid resin composition obtained in the kneading process is transferred to a molding machine, and the polylactic acid resin composition is molded using the molding machine to form a molded body such as a film or sheet. The process of molding a film or sheet is called film formation. The temperature when molding the film or sheet may preferably be set to a temperature above the melting temperature of the polylactic acid resin, for example, 110°C to 200°C. The molding pressure may also be set as appropriate. 【0066】 When forming films or sheets, various film-forming machines such as T-die extruders, calenders, and inflation molders can be used. For example, a ring die may be used as an inflation molder. After the film is formed, the molded product, for example, in the form of a film or sheet, may be immediately cooled by setting the temperature of the take-up roll appropriately, and then taken up and wound as a raw material roll. A film is a thin, film-like material, and the thickness of a film may be, for example, less than 100 μm. A sheet is thicker than a film, and the thickness of a sheet may be, for example, 100 μm or more. In addition, when forming molded products other than films and sheets, blow molding machines, injection molding machines, thermoforming machines, and shape extrusion molding machines may be used. For example, a bottle container can be formed using a blow molding machine. For example, a bottle cap or container can be manufactured using an injection molding machine. For example, corrugated plastic can be formed using a shape extrusion molding machine. 【0067】 In the molding process described above, for example, the polylactic acid composition may be extruded directly from the film-forming machine or molding machine without being pelletized, or the pelletized polylactic acid composition may be melted and then the molten polylactic acid composition may be extruded from the film-forming machine or molding machine. The extrusion temperature may be appropriately selected by those skilled in the art depending on the type and proportion of citrate ester contained in the polylactic acid composition. 【0068】 For example, when the citrate ester is triethyl acetyl citrate (ATEC), extrusion may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, extrusion may be carried out at a temperature of 145°C or lower, preferably 140°C or lower, more preferably 135°C or lower, and even more preferably 130°C or lower. 【0069】 For example, when the citrate ester is tributyl acetylcitrate (ATBC), extrusion may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, extrusion may be carried out at a temperature of preferably 145°C or lower, more preferably 140°C or lower, even more preferably 135°C or lower, and even more preferably 130°C or lower. 【0070】 For example, if the citrate ester is a mixture of triethyl acetyl citrate (ATEC) and tributyl acetyl citrate (ATBC), extrusion may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, extrusion may be carried out at a temperature of preferably 145°C or lower, more preferably 140°C or lower, even more preferably 135°C or lower, and even more preferably 130°C or lower. 【0071】 3. Second Embodiment (Another Example of a Molded Body) 【0072】 (1) Configuration of other examples of molded bodies 【0073】 [Molded body] 【0074】 The molded article according to this embodiment contains polylactic acid, a citrate ester, and a biomass material. 【0075】 In this embodiment, the polylactic acid content is preferably 45% by mass or more, more preferably 50% by mass or more, and even more preferably 55% by mass or more, relative to the mass of the molded article. Furthermore, the polylactic acid content is preferably 60% by mass or less, more preferably 58% by mass or less, and even more preferably 56% by mass or less, relative to the mass of the molded article. 【0076】 In the molded article according to this embodiment, the citrate ester content is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more, based on the mass of the molded article. Furthermore, the citrate ester content is preferably 35% by mass or less, more preferably 30% by mass or less, and even more preferably 28% by mass or less, based on the mass of the molded article. 【0077】 In the molded article according to this embodiment, when the biomass material is cellulose powder, the cellulose powder content is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the mass of the molded article. Furthermore, the cellulose powder content is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the mass of the molded article. 【0078】 In the molded article according to this embodiment, when the biomass material is starch, the starch content is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the mass of the molded article. Furthermore, the starch content is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the mass of the molded article. 【0079】 In the molded article according to this embodiment, when the biomass material is eggshell powder, the eggshell powder content is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the mass of the molded article. Furthermore, the eggshell powder content is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the mass of the molded article. 【0080】 In the molded article according to this embodiment, when the biomass material is seashell powder, the content of seashell powder is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the mass of the molded article. Furthermore, the content of seashell powder is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the mass of the molded article. 【0081】 (2) Explanation of each component 【0082】 [Polylactic acid] 【0083】 Since the explanation of polylactic acid in the first embodiment applies, the explanation of polylactic acid will be omitted. 【0084】 [Citrate ester] 【0085】 Since the description of citrate esters in the first embodiment applies, the explanation of citrate esters will be omitted. 【0086】 [Biomass materials] 【0087】 The molded article according to this embodiment may further contain biomass material. Examples of such biomass material include plant-derived biomass material and biologically derived biomass material. Examples of plant-derived biomass material include cellulose powder and starch. The cellulose powder and starch may be classified as waste biomass, unused biomass, or resource grain. Examples of biologically derived biomass material include eggshell powder and seashell powder. 【0088】 <Cellulose powder> 【0089】 Examples of cellulose powder include crushed paper, paper pulp, cotton, or cloth. 【0090】 The particle size D50 (median diameter) of the cellulose powder is, for example, 15 μm to 150 μm, and particularly preferably 20 μm to 100 μm. The particle size D50 is determined by wet measurement using a laser diffraction particle size distribution analyzer (SALD-3100, Shimadzu Corporation). Having a particle size within the above numerical range of the cellulose powder can contribute to improving the dispersibility of the cellulose powder contained in the molded article. 【0091】 In this embodiment, the number of cellulose fibers having a particle size of 9.8 μm to 110.6 μm among the cellulose fibers constituting the cellulose powder accounts for 65% to 100%, preferably 70% to 100%, more preferably 80% to 100%, and even more preferably 85% to 100% of the total number of cellulose fibers constituting the cellulose powder. The above proportions regarding the number of cellulose fibers are determined by wet measurement using the laser diffraction particle size distribution analyzer to determine the proportion of cellulose fibers having a particle size of 0 μm to 9.8 μm (hereinafter referred to as the "first proportion") and the proportion of cellulose fibers having a particle size of 0 μm to 110.6 μm (hereinafter referred to as the "second proportion") among the total number of cellulose fibers in the cellulose powder, and then subtracting the first proportion from the second proportion. The numerical ranges "0 μm to 9.8 μm" and "0 μm to 110.6 μm" are both numerical ranges input to the laser diffraction particle size distribution analyzer during the wet measurement. 【0092】 In this embodiment, particularly preferably, the number of cellulose fibers having a particle size of 110.6 μm to 998.4 μm among the cellulose fibers constituting the cellulose powder accounts for 0% to 30%, preferably 0% to 25%, more preferably 0% to 20%, and even more preferably 0% to 15% of the total number of cellulose fibers constituting the cellulose powder. The above proportions regarding the number of cellulose fibers are determined by wet measurement using the laser diffraction particle size distribution analyzer to determine the proportion of cellulose fibers having a particle size of 0 μm to 110.6 μm (the "second proportion" above) and the proportion of cellulose fibers having a particle size of 0 μm to 998.4 μm (hereinafter referred to as the "third proportion") among the total number of cellulose fibers in the cellulose powder, and then subtracting the second proportion from the third proportion. The numerical ranges "0 μm to 110.6 μm" and "0 μm to 998.4 μm" are both numerical ranges input to the laser diffraction particle size distribution analyzer during the wet measurement. 【0093】 Cellulose powder having the above particle size distribution can be produced, for example, by treating pulp with chemicals such as acids. An example of cellulose powder having the above particle size distribution is KC Floc W400 (Nippon Paper Industries Co., Ltd.). 【0094】 By using cellulose powder having the above particle size distribution, better moldability is achieved when manufacturing molded articles such as films using a polylactic acid resin composition obtained by kneading polylactic acid and citrate ester. 【0095】 In particular, if the number of cellulose fibers having a particle size of 9.8 μm to 110.6 μm among the cellulose fibers constituting the cellulose powder accounts for 80% to 100%, and more preferably 85% to 100%, of the total number of cellulose fibers constituting the cellulose powder, then tearing or the occurrence of holes in films, etc., obtained by molding the polylactic acid resin composition can be prevented. In order to prevent tearing or the occurrence of holes in films, etc., it is particularly preferable that the number of cellulose fibers having a particle size of 110.6 μm to 998.4 μm among the cellulose fibers constituting the cellulose powder accounts for 0% to 20%, and more preferably 0% to 15%, of the total number of cellulose fibers constituting the cellulose powder. 【0096】 According to another preferred embodiment of the present invention, the cellulose powder may have a particle size in which 90% or more of the particles pass through a 100-mesh grid. In this embodiment, more preferably, the cellulose powder may have a particle size in which 90% or more of the particles pass through a 100-mesh grid, and the apparent specific gravity of the cellulose powder may be 0.30 g / ml to 0.40 g / ml. 【0097】 The particle size is measured by the standard sieving method, specifically as follows: 10 g of the sample is placed in a 100-mesh standard sieve, a tray and lid are set on the sieve, and the sample is shaken for 40 minutes using a rotary shaker. The particle size is then calculated from the sample mass (10 g) and the mass of the sieved residue using the following formula. Particle size (%) = [(Sample mass (g) - Sieve residue (g)) / Sample mass (g)] × 100 【0098】 The apparent specific gravity is measured as follows: 10 g of the sample is accurately weighed on a balance and placed in a 50 ml graduated cylinder. The bottom of the graduated cylinder is tapped on a rubber-covered surface, taking care not to let the sample spill. This tapping is continued until no more sample can clog the cylinder. After tapping, the surface of the sample is flattened, and the scale (volume, ml) is read. The apparent specific gravity is then calculated using the following formula. Apparent specific gravity (g / ml) = Sample (10g) / Volume (ml) 【0099】 Cellulose powder having the above particle size (or the above particle size and apparent specific gravity) can be produced, for example, by mechanically grinding pulp (e.g., by jet mill grinding). An example of cellulose powder having the above particle size (or the above particle size and apparent specific gravity) is KC Floc 100GK. 【0100】 In this embodiment, the content of cellulose powder is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the mass of the molded article. 【0101】 Furthermore, the content of cellulose powder is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the mass of the molded article. 【0102】 <Starch> 【0103】 Examples of starches include underground starches and above-ground starches. Underground starches are starches accumulated underground, such as those accumulated in rhizomes or roots. Examples of underground starches include, but are not limited to, tapioca starch (cassava starch), potato starch, sweet potato starch, kudzu starch, and bracken starch. 【0104】 Ground-based starches are starches accumulated on the ground, such as those accumulated in seeds. Examples of ground-based starches include, but are not limited to, corn starch, wheat starch, sago starch, acorn starch, and rice starch. 【0105】 In this embodiment, underground starch is preferably used. 【0106】 The starch may be a modified starch (i.e., modified starch), particularly a modified underground starch. Examples of such modified starches include physically modified starch and chemically modified starch. Examples of physically modified starches include alpha starch and moist heat starch. Examples of chemically modified starches include acetoacetate esterified starch, acetate esterified starch, hydroxymethyl etherified starch, hydroxypropyl etherified starch, carboxymethyl etherified starch, allyl etherified starch, methyl etherified starch, succinate esterified starch, xanthogene acetate esterified starch, nitrate esterified starch, urea phosphate esterified starch, phosphate esterified starch, phosphate cross-linked starch, formaldehyde cross-linked starch, acrolein cross-linked starch, and epichlorohydrin cross-linked starch. 【0107】 Furthermore, if the starch is corn starch, its particle size is preferably 5 μm or larger, more preferably 10 μm or larger, and even more preferably 15 μm or larger. The upper limit of the particle size is not particularly limited, but is preferably 50 μm or smaller, more preferably 40 μm or smaller, and even more preferably 30 μm or smaller. 【0108】 Furthermore, if the starch is tapioca starch, its particle size is preferably 2 μm or larger, more preferably 10 μm or larger, and even more preferably 15 μm or larger. The upper limit of the particle size is not particularly limited, but is preferably 40 μm or smaller, more preferably 30 μm or smaller, and even more preferably 25 μm or smaller. 【0109】 Furthermore, if the starch is potato starch, its particle size is preferably 2 μm or larger, more preferably 20 μm or larger, and even more preferably 30 μm or larger. The upper limit of the particle size is not particularly limited, but is preferably 80 μm or smaller, more preferably 60 μm or smaller, and even more preferably 40 μm or smaller. 【0110】 Furthermore, the starch may preferably contain equilibrium water. The amount of equilibrium water may be, for example, preferably 10% to 15% by mass, more preferably 10% to 14% by mass, even more preferably 10% to 13% by mass, and even more preferably 11% to 13% by mass, relative to the mass of starch. 【0111】 In this embodiment, the starch content is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the mass of the molded article. 【0112】 Furthermore, the starch content is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the mass of the molded article. 【0113】 <Eggshell powder> 【0114】 The eggshells used as raw materials for eggshell powder can include those from birds such as chickens, quail, ostriches, ducks, and geese, but chicken eggshells are preferred from the standpoint of ease of availability. 【0115】 Eggshell powder can be obtained by washing, drying, and grinding eggshells that are discarded as waste from food processing plants. Specifically, eggshells from chicken eggs and other eggs, after being cracked open and the contents removed, can be washed with water, dried, and then ground to obtain eggshell powder. The drying method is not particularly limited and can include natural drying, hot air drying, and heat drying. Drying conditions such as drying time and drying temperature can also be set as appropriate. Methods for grinding eggshells include using hammer mills, ball mills, jet mills, turbo mills, pin mills, and roll mills. 【0116】 Furthermore, commercially available eggshell powders or those produced by calcining at high temperatures may be used as the eggshell powder. In addition, if the raw material eggs are not white, eggshell powder that has been decolorized using an oxidizing chlorine bleach, an oxidizing oxygen bleach, or a reducing bleach after grinding may be used. 【0117】 In this embodiment, the eggshell powder content is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the mass of the molded article. 【0118】 Furthermore, the eggshell powder content is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the mass of the molded article. 【0119】 <Seashell powder> 【0120】 Examples of shells used as raw materials for shell powder include scallops, oysters, clams, freshwater clams, and surf clams. 【0121】 Shell powder can be obtained by crushing shells that are discharged as waste from seafood processing plants. Specifically, shells of scallops and other shells from which the contents have been removed can be washed with water, dried, and then crushed to obtain shell powder. The drying method is not particularly limited, and can be natural drying, hot air drying, or heat drying. Drying conditions such as drying time and drying temperature can also be set as appropriate. Methods for crushing shells include using a hammer mill, ball mill, jet mill, turbo mill, pin mill, or roll mill. Alternatively, shells can be washed with water, dried, calcined, and then crushed to obtain calcined shell powder. The calcination method is not particularly limited and may be carried out in the atmosphere or in an oxidizing atmosphere. The calcination temperature and calcination time can also be set as appropriate. 【0122】 Alternatively, various commercially available shell powders can be used as shell powder. Examples of such shell powders include scallop shell powder derived from scallop shells, such as "Product Name: Scallop Powder (manufactured by N.C. Corporation)" and "Scallop Powder S (manufactured by N.C. Corporation)." 【0123】 In this embodiment, the content of seashell powder is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, relative to the mass of the molded body. 【0124】 Furthermore, the content ratio of seashell powder is preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less, relative to the mass of the molded body. 【0125】 (3) Physical properties 【0126】 [Tensile properties] 【0127】 The molded article according to this embodiment has a tensile modulus of elasticity of 1.5 GPa or more, preferably 1.7 GPa or more, and more preferably 2.0 GPa or more. Furthermore, there is no particular upper limit to the tensile modulus of elasticity, but it is preferably 3 GPa or less, more preferably 2.8 GPa or less, and even more preferably 2.5 GPa or less. 【0128】 The molded article according to this embodiment has a tensile elongation of 1% or more, preferably 3% or more, more preferably 5% or more, and even more preferably 7% or more. Furthermore, there is no particular upper limit to the tensile elongation, but it is preferably 30% or less, more preferably 28% or less, and even more preferably 25% or less. 【0129】 The molded article according to this embodiment has a tensile strength, which is a tensile property, preferably 10 MPa or more, more preferably 15 MPa or more, and even more preferably 20 MPa or more. Furthermore, there is no particular upper limit to the tensile strength, but the tensile strength is preferably 30 MPa or less, more preferably 28 MPa or less, and even more preferably 25 MPa or less. 【0130】 The explanation regarding the measurement of tensile properties described above applies to the measurement of tensile properties in the first embodiment, so the explanation regarding the measurement of tensile properties will be omitted. 【0131】 (4) Method for manufacturing molded articles 【0132】 The method for manufacturing a molded article according to this embodiment is: A kneading step to obtain a polylactic acid composition by heating and kneading polylactic acid, citrate ester, and biomass material at a temperature of 130°C or lower, A molding step is performed to mold the polylactic acid composition obtained in the kneading step to obtain a molded body, It is equipped with. The polylactic acid resin composition according to this embodiment can be produced by the method for producing the polylactic acid resin composition according to this embodiment. 【0133】 The following explains each step. 【0134】 [Mixing process] 【0135】 In the kneading process, polylactic acid, citrate ester, and biomass material are heated and kneaded at a temperature of 130°C or lower. In the kneading process, the polylactic acid, citrate ester, and biomass material may be mixed first. Alternatively, after mixing is complete, the mixed raw materials may be heated and kneaded. In the kneading process, the polylactic acid and citrate ester may be heated to a temperature at which they can melt. This temperature may be appropriately selected by those skilled in the art depending on the type of citrate ester used and its content. 【0136】 In the aforementioned kneading step, for example, if the citrate ester is triethyl acetyl citrate (ATEC), the kneading may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, the kneading may be carried out at a temperature of 130°C or lower, preferably 125°C or lower, and even more preferably 123°C or lower. 【0137】 In the aforementioned kneading step, for example, if the citrate ester is tributyl acetylcitrate (ATBC), the kneading may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, the kneading may be carried out at a temperature of 130°C or lower, preferably 125°C or lower, and even more preferably 123°C or lower. 【0138】 In the aforementioned kneading step, for example, if the citrate ester is a mixture of triethyl acetyl citrate (ATEC) and tributyl acetyl citrate (ATBC), the kneading may be carried out at a temperature of preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher. Alternatively, the kneading may be carried out at a temperature of 130°C or lower, preferably 125°C or lower, and more preferably 123°C or lower. 【0139】 The mixing of polylactic acid, citrate ester, and biomass material may be carried out using a mixer such as a high-temperature stirrer, Henschel mixer, tumbler mixer, Barber mixer, or kneader mixer. The heating and kneading of the mixed raw materials may be carried out using a single-screw kneading extruder or a twin-screw kneading extruder, for example. As these kneading extruders, devices known in the art may be used. Preferably, the kneading step includes at least heating and kneading treatment using a twin-screw kneading extruder. As the twin-screw kneading extruder, a co-rotating twin-screw kneading extruder or a twin-screw kneading extruder rotating in opposite directions may be used. By performing the kneading treatment with a twin-screw kneading extruder, a polylactic acid composition, which is a kneaded product in which the raw materials are more uniformly dispersed, can be obtained. 【0140】 The polylactic acid composition obtained in the aforementioned kneading step may be used directly in the molding step without being pelletized. This eliminates the need for the pelletizing step. Furthermore, the polylactic acid composition obtained in the kneading step may be pelletized. The pelletized polylactic acid composition may then be subjected to a molding step. 【0141】 [Molding process] 【0142】 The description of the molding process in the first embodiment applies, so the description of the molding process will be omitted. 【0143】 4. Examples 【0144】 The present technology will be described in detail below with reference to examples, but the present technology is not limited to these examples. 【0145】 In the following examples and comparative examples, the tensile properties (tensile modulus, tensile elongation, tensile strength) and darting impact strength of the molded article are values ​​obtained by the measurement method described in the first embodiment. 【0146】 Test Example 1: Manufacturing of a molded body (first embodiment) 【0147】 [Example 1] 【0148】 As shown in Table 1 below, the components were prepared so that the molded product contained 85% by mass of polylactic acid (product name "REVODE110," manufactured by Zhejiang Haizheng Biomaterials Co., Ltd.) and 15% by mass of triethyl acetyl citrate (manufactured by Jungbunzlauer). These two components were mixed in a mixer (manufactured by LAB TECH Engineering Co., Ltd.). The mixing was performed at room temperature, with the mixer speed set to 500 RPM and the mixing time set to 5 minutes. 【0149】 The mixture obtained by the above mixing was supplied into a twin-screw extruder (PCM30, Ikegai Co., Ltd., screw diameter: 30φ), and the mixture was then subjected to a kneading process. 【0150】 The screw temperature (kneading temperature) in the kneading process was set to 115°C. After the kneading process, the mixture was extruded from the die of the extruder, and elongated, roughly cylindrical pellets were obtained. Pellets of the polylactic acid resin composition (hereinafter also referred to as "the polylactic acid resin composition of Example 1") were obtained through this kneading process. 【0151】 Pellets of the polylactic acid resin composition from Example 1 were supplied to a hot press (manufactured by LAB TECH Engineering Co., Ltd.), and hot pressing was performed at 180°C. A sheet with a thickness of 500 μm was obtained by this hot pressing. 【0152】 The tensile modulus, tensile elongation, and tensile strength of the obtained sheet were measured according to the method described in the first embodiment. The obtained sheet had a tensile modulus of 2.6 GPa, a tensile elongation of 157.7%, and a tensile strength of 40.8 MPa. The dirt impact strength at 20°C was 45 g, and the dirt impact strength at -10°C was 60 g. 【0153】 [Table 1] 【0154】 [Example 2] 【0155】 A sheet was obtained using the same method as in Example 1, except that the polylactic acid (product name "REVODE110", manufactured by Zhejiang Haizheng Biomaterials Co., Ltd.) content was 75% by mass, and the tributyl acetylcitrate (manufactured by Taoka Chemical Industry Co., Ltd.) content was 25% by mass instead of triethyl acetylcitrate (manufactured by Jungbunzlauer). The obtained sheet had a tensile modulus of 2.1 GPa, a tensile elongation of 148%, and a tensile strength of 34.2 MPa. The dirt impact strength at 20°C was 50 g, and the dirt impact strength at -10°C was 32 g. The measurement results are shown in Table 1 above. 【0156】 [Example 3] 【0157】 A sheet was obtained in the same manner as in Example 1, except that instead of triethyl acetyl citrate (manufactured by Jungbuntzlauer), a mixture of triethyl acetyl citrate (manufactured by Jungbuntzlauer) and tributyl acetyl citrate (manufactured by Taoka Chemical Industry Co., Ltd.) (ATBC:ATEC=4:1) was used, with a content ratio of 15% by mass. The obtained sheet had a tensile modulus of 3 GPa, a tensile elongation of 140.4%, and a tensile strength of 45.4 MPa. The dirt impact strength at 20°C was 90 g, and the dirt impact strength at -10°C was 45 g. The measurement results are shown in Table 1 above. 【0158】 [Comparative Example 1] 【0159】 Example 1 is the same method as Example 1, except that the polylactic acid (product name "REVODE110," manufactured by Zhejiang Haizheng Biomaterials Co., Ltd.) content in the polylactic acid resin composition was 100% by mass without the addition of triethyl acetyl citrate (manufactured by Jungbunzlauer), and the screw temperature (kneading temperature) during the kneading process was set to 170°C. The obtained sheet had a tensile modulus of 3.4 GPa, a tensile elongation of 4.6%, and a tensile strength of 57.9 MPa. The dirt impact strength at 20°C was 47 g, and the dirt impact strength at -10°C was 42 g. The measurement results are shown in Table 1 above. 【0160】 [Comparative Example 2] 【0161】 The sheet was obtained using the same method as in Example 1, except that the screw temperature (kneading temperature) during the kneading process was set to 155°C. The obtained sheet had a tensile modulus of 1.2 GPa, a tensile elongation of 190.9%, and a tensile strength of 34.4 MPa. The dirt impact strength at 20°C was 42 g, and the dirt impact strength at -10°C was 37 g. The measurement results are shown in Table 1 above. 【0162】 Figure 1 shows the tensile modulus of each of Examples 1, 2, 3, Comparative Example 1, and Comparative Example 2. Figure 2 shows the tensile elongation of each of Examples 1, 2, 3, Comparative Example 1, and Comparative Example 2. Figure 3 shows the tensile strength of each of Examples 1, 2, 3, Comparative Example 1, and Comparative Example 2. 【0163】 The results shown in Table 1, Figure 1, and Figure 2 indicate the following: 【0164】 The sheets in Examples 1 to 3 all had a tensile modulus of 1 GPa or higher and a tensile elongation of 100% or higher, exhibiting both a high tensile modulus and a large tensile elongation. 【0165】 Test Example 2: Relationship between mixing temperature and tensile properties of molded product 【0166】 [Example 4] 【0167】 Similar to Example 1, the screw temperature (kneading temperature) during the kneading process was set to 115°C, and a sheet was obtained using the same method as in Example 1. 【0168】 The tensile modulus, tensile elongation, and tensile strength of the obtained sheet were measured according to the method described in the first embodiment. The obtained sheet had a tensile modulus of 2.6 GPa, a tensile elongation of 157.7%, and a tensile strength of 40.8 MPa. The dirt impact strength at 20°C was 45 g, and the dirt impact strength at -10°C was 60 g. The measurement results are shown in Table 2 below. 【0169】 [Table 2] 【0170】 [Comparative Example 3] 【0171】 The sheet was obtained using the same method as in Example 1, except that the screw temperature (kneading temperature) during the kneading process was set to 130°C. The obtained sheet had a tensile modulus of 3.1 GPa, a tensile elongation of 12.3%, and a tensile strength of 48.7 MPa. The dirt impact strength at 20°C was 32 g, and the dirt impact strength at -10°C was 37 g. The measurement results are shown in Table 2 above. 【0172】 [Comparative Example 4] 【0173】 The sheet was obtained using the same method as in Example 1, except that the screw temperature (kneading temperature) during the kneading process was set to 145°C. The obtained sheet had a tensile modulus of 3 GPa, a tensile elongation of 2.6%, and a tensile strength of 51.6 MPa. The dirt impact strength at 20°C was 32 g, and the dirt impact strength at -10°C was 42 g. The measurement results are shown in Table 2 above. 【0174】 [Comparative Example 5] 【0175】 The sheet was obtained using the same method as in Example 1, except that the screw temperature (kneading temperature) during the kneading process was set to 155°C. The obtained sheet had a tensile modulus of 3.3 GPa, a tensile elongation of 2.8%, and a tensile strength of 57.3 MPa. The dirt impact strength at 20°C was 37 g, and the dirt impact strength at -10°C was 35 g. The measurement results are shown in Table 2 above. 【0176】 Figure 4 shows the tensile modulus for Example 4, Comparative Example 3, Comparative Example 4, and Comparative Example 5. Figure 5 shows the tensile elongation for Example 4, Comparative Example 3, Comparative Example 4, and Comparative Example 5. 【0177】 The results shown in Table 2, Figure 4, and Figure 5 indicate the following: 【0178】 The sheet of Example 4 had a tensile modulus of 1 GPa or higher and a tensile elongation of 100% or higher, exhibiting both a high tensile modulus and a large tensile elongation. On the other hand, Comparative Examples 3, 4, and 5, in which the screw temperature (kneading temperature) during the kneading process was higher than that of Example 4, exhibited smaller tensile elongations. From the above, it can be seen that polylactic acid containing triethyl acetylcitrate (manufactured by Jungbunzlauer) exhibits improved tensile elongation when the kneading temperature is reduced. 【0179】 This technology can also employ the following configuration: [1] Polylactic acid and, Citric acid ester and, A molded article containing a material, having a tensile modulus of 1.5 GPa or more, and a tensile elongation of 100% or more. [2] The molded article according to [1], wherein the citrate ester is triethyl acetylcitrate. [3] The molded article according to [1], wherein the citrate ester is tributyl acetylcitrate. [4] The molded article according to [1], comprising the citrate ester triethyl acetylcitrate and tributyl acetylcitrate. [5] A molded article as described in any one of [1] to [4], wherein the dirt impact strength at 20℃ is 40g or more. [6] The molded article described in any one of [1] to [4] has a dirt impact strength of 30g or more at -10℃. [7] A molded article according to any one of [1] to [6], wherein the molded article is a sheet or a film. [8] A kneading step in which polylactic acid and citrate ester are heated and kneaded at 130°C or below to obtain a polylactic acid composition, A molding step is performed to mold the polylactic acid composition obtained in the kneading step to obtain a molded body, A method for manufacturing a molded article comprising the features described above. 【0180】 Although embodiments and examples of this technology have been described in detail above, this technology is not limited to the embodiments and examples described above, and various modifications based on the technical concept of this technology are possible. 【0181】 For example, the configurations, methods, processes, shapes, materials, and numerical values ​​listed in the above embodiments and examples are merely examples, and different configurations, methods, processes, shapes, materials, and numerical values ​​may be used as needed. Furthermore, the chemical formulas of compounds are representative examples, and the general name of the same compound is not limited to those listed. 【0182】 Furthermore, the configurations, methods, processes, shapes, materials, and numerical values ​​of the above-described embodiments and examples can be combined with each other, as long as they do not deviate from the spirit of this technology. 【0183】 Furthermore, in this specification, numerical ranges indicated using "~" represent a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this specification, the upper or lower limit of one step in the numerical range may be replaced with the upper or lower limit of another step in the numerical range. Unless otherwise specified, the materials exemplified in this specification may be used individually or in combination of two or more.

Claims

[Claim 1] Polylactic acid and, Citric acid ester and, A molded article containing a material, having a tensile modulus of elasticity of 1.5 GPa or more as measured in accordance with JIS K7161, and a tensile elongation of 100% or more at the time of sample fracture as measured in accordance with JIS K7161. [Claim 2] The molded article according to claim 1, wherein the citrate ester is triethyl acetylcitrate. [Claim 3] The molded article according to claim 1, wherein the citrate ester is tributyl acetylcitrate. [Claim 4] The molded article according to claim 1, wherein the citrate ester comprises triethyl acetylcitrate and tributyl acetylcitrate. [Claim 5] The molded article according to claim 1, wherein the dirt impact strength at 20°C, as measured in accordance with JIS K 7124 Method B, is 40 g or more. [Claim 6] The molded article according to claim 1, wherein the dirt impact strength at -10°C, as measured in accordance with JIS K 7124 Method B, is 30 g or more. [Claim 7] The molded article according to claim 1, wherein the tensile strength measured in accordance with JIS K7161 is 30 MPa or more. [Claim 8] The molded article according to claim 1, wherein the molded article is a sheet or a film. [Claim 9] A kneading step to obtain a polylactic acid composition by heating and kneading polylactic acid and citrate ester at 100°C to 125°C, A molding step is performed to mold the polylactic acid composition obtained in the kneading step to obtain a molded body, A method for manufacturing a molded article comprising the features described above.

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