Biomass resin composition, method for producing biomass resin composition, and molded article

Abstract

To provide a biomass resin composition that enables production of a molded article having enhanced heat resistance.SOLUTION: A biomass resin composition contains (A) a biomass resin, (B) carbon fibers, and (C) carbon powder. The (A) biomass resin is a crystalline resin containing a biologically derived component. The content of the (B) carbon fibers is 10 pts.mass or more and 50 pts.mass or less relative to 100 pts.mass of the (A) biomass resin.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a biomass resin composition, a method for producing the biomass resin composition, and a molded article made of the biomass resin composition. [Background technology]

[0002] Biomass plastics made from biomass are known. For example, the carbon dioxide emitted during the manufacturing process of biomass plastics made from plant-derived components can be offset by the carbon dioxide absorbed from the atmosphere by photosynthesis during the growth of the plants that are the raw materials. As such, biomass plastics are carbon-neutral materials and can contribute to the prevention of global warming.

[0003] Conventional plastics are primarily made from petroleum-based materials. Petroleum-based materials are finite and subject to depletion. In contrast, biomass is a renewable, non-renewable resource. For this reason, the production and use of biomass plastics can be said to be sustainable.

[0004] In the past, a method of adding glass fiber or carbon fiber to a molding resin material has been known to improve the strength characteristics of a resin molded product. For example, Patent Documents 1 and 2 disclose molding materials containing carbon fiber.

[0005] Resin molded products containing carbon fibers have high specific strength and impact resistance, as well as thermal conductivity, and are therefore expected to be substitutes for metal parts.

[0006] The production of the above-mentioned carbon fibers requires a large amount of energy. Furthermore, the carbon fibers are produced through a complicated manufacturing process. In response to this, Patent Documents 2 and 3 propose the use of recycled carbon fibers. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2014-145036 A [Patent Document 2] Special Publication No. 2016-540067 [Patent Document 3] JP 2017-2125 A Summary of the Invention [Problem to be solved by the invention]

[0008] Resin molded articles made from biomass as a raw material have a problem of low heat resistance. Patent Documents 1 and 2, which disclose molding materials reinforced with carbon fiber, make no mention of heat resistance. There is a demand for improving the heat resistance of molded articles made from biomass resin compositions. [Means for solving the problem]

[0009] The biomass resin composition for solving the above problems contains (A) biomass resin, (B) carbon fiber, and (C) carbon powder, wherein the (A) biomass resin is a crystalline resin containing components derived from living organisms, and the content of the (B) carbon fiber is 10 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the (A) biomass resin.

[0010] An example of the method for producing the biomass resin composition includes an attachment step of attaching a sizing agent to the (B) carbon fiber and the (C) carbon powder, and a kneading step of kneading the (A) biomass resin, the (B) carbon fiber, and the (C) carbon powder while heating them using a kneader, and the kneading step is performed after the attachment step.

[0011] An example of the method for producing the biomass resin composition includes a kneading step of kneading the (A) biomass resin, the (B) carbon fiber, and the (C) carbon powder while heating them using a kneader, and the kneading step includes a first kneading step of feeding the (A) biomass resin into the kneader and kneading the (A) biomass resin, and a second kneading step of feeding the (B) carbon fiber into the kneader that contains a molten material obtained by heating and melting the (A) biomass resin in the first kneading step and a solid of the (A) biomass resin, and kneading the molten material, the solid of the (A) biomass resin, and the (B) carbon fiber.

[0012] A molded article for solving the above problem is a molded article made of the above biomass resin composition. Effect of the Invention

[0013] According to the present invention, it is possible to improve the heat resistance of a molded article made of a biomass resin composition. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing an extruder used in producing a biomass resin composition. [Diagram 2] FIG. 2 is a schematic diagram showing an extruder used in producing a biomass resin composition. [Diagram 3] FIG. 3 is a schematic diagram showing an extruder used in producing a biomass resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, one embodiment of the biomass resin composition will be described. The biomass resin composition of this embodiment contains (A) biomass resin, (B) carbon fiber, and (C) resin carbonized material. Hereinafter, the resin contained in the resin composition may be referred to as a matrix component, meaning the base material of the resin composition. (A) Biomass resin is the matrix component of the biomass resin composition.

[0016] (A) Biomass Resin Biomass resin is a synthetic resin that contains biologically derived components. Biomass resin is a thermoplastic resin. Biomass resin is a crystalline resin.

[0017] The biomass resin may or may not be biodegradable. Specific examples of biomass resins include polylactic acid (hereinafter sometimes referred to as PLA), polybutylene succinate derived from biomass raw materials (hereinafter sometimes referred to as Bio-PBS), and the like.

[0018] A preferred biomass resin is PLA, which is a biodegradable crystalline resin containing plant-derived components. The biomass resin may be used alone or in combination of two or more kinds.

[0019] (B) Carbon fiber The carbon fiber is not particularly limited, and may be a PAN-based carbon fiber or a pitch-based carbon fiber. The fiber length of the carbon fiber is not particularly limited.

[0020] The carbon fibers contained in the biomass resin composition are preferably recycled carbon fibers recovered from raw materials for recycling. A known method can be used to recover carbon fibers from raw materials for recycling, such as a pyrolysis method.

[0021] The matrix component of the raw material for recycling is not particularly limited, and may be a thermoplastic resin or a thermosetting resin. The matrix component of the raw material for recycling is preferably a thermosetting resin.

[0022] The raw material for recycling may be scraps containing carbon fibers, waste materials containing carbon fibers, etc. Examples of the raw material for recycling include scraps of prepregs, prepregs whose expiration date has passed, etc.

[0023] For example, recycled carbon fibers are obtained by recovering a long-fiber prepreg sheet in which long carbon fibers are impregnated with a thermosetting resin, or a prepreg product manufactured using the long-fiber prepreg sheet, as a raw material for recycling, in a state in which the fibers are aligned in one direction. In addition, the recycled carbon fibers may be obtained in a state in which the carbon fibers are fixed together by the resin char remaining when the thermosetting resin is carbonized.

[0024] In the biomass resin composition, the content of the carbon fiber as the component (B) is 10 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the biomass resin as the component (A). The lower limit of the above range is preferably 15 parts by mass, and more preferably 20 parts by mass. The upper limit of the above range is preferably 40 parts by mass, and more preferably 30 parts by mass.

[0025] (C) Carbon powder Carbon powder refers to fine carbon particles, the particle size of which is, for example, 0.1 μm or more and 10 μm or less.

[0026] In the biomass resin composition, the content of carbon powder as component (C) is preferably 10 parts by mass or more and 20 parts by mass or less per 100 parts by mass of carbon fiber as component (B).

[0027] The carbon powder contained in the biomass resin composition is preferably a resin charcoal. For example, the carbon powder is a charcoal obtained as a by-product when producing recycled carbon fibers. More specifically, the carbon powder is a charcoal obtained in a state of adhering to the surface of the recycled carbon fibers together with the recycled carbon fibers recovered from the raw materials for recycling as a product derived from the resin contained in the raw materials for recycling. In this case, the resin charcoal can be said to be a residue of the matrix, etc., contained in the raw materials for recycling.

[0028] The amount of resin char obtained in a state attached to the recycled carbon fiber can be adjusted by the conditions when recovering the recycled carbon fiber. For example, the amount of resin char can be adjusted by the temperature during pyrolysis, the presence or absence of oxygen during pyrolysis, etc. In addition, the amount of resin char varies depending on the components contained in the raw material for recycling. For example, if the matrix component of the raw material for recycling is a thermosetting resin, the amount of carbon powder attached to the recycled carbon fiber is likely to be within the above range.

[0029] <Sizing agent> The biomass resin composition may contain a sizing agent. The sizing agent is not particularly limited, and polyester resin-based sizing agents, urethane resin-based sizing agents, and epoxy resin-based sizing agents can be used.

[0030] For example, a sizing agent may be selected based on the results of measuring the interfacial shear strength between the carbon fiber and the matrix component by a microdroplet method using a composite interface property evaluation device.

[0031] <Other Ingredients> The biomass resin composition may contain other components in addition to the above-mentioned components. The other components can be blended in an amount that does not impair the effects of the biomass resin composition.

[0032] Examples of the other components include a plasticizer, a colorant, a release agent, a stabilizer, an antioxidant, a compatibilizer, etc. The biomass resin composition may use two or more of the other components in combination.

[0033] <Uses of biomass resin composition> The use of the biomass resin composition is not particularly limited, but for example, it can be used as a molding resin material for producing a molded product. The form of the molding resin material is not particularly limited, but examples include pellets, films, etc.

[0034] <Method for producing biomass resin composition> The method for producing a biomass resin composition includes a kneading step of kneading (A) a biomass resin, (B) carbon fiber, and (C) carbon powder with a kneader while heating them. The biomass resin composition is obtained, for example, by solidifying the kneaded product obtained in the kneading step.

[0035] Examples of the kneading machine include an extruder, a Banbury mixer, a kneader, a high shear processing machine, etc. Examples of the extruder include a single screw extruder, a twin screw extruder, and an extruder having a combination of a single screw and a twin screw.

[0036] The method for producing a biomass resin composition may include other steps. For example, the method for producing a biomass resin composition may include a step of adhering a sizing agent to the carbon fibers (B). In this case, the kneading step is carried out after the adhering step.

[0037] The method of applying the sizing agent is not particularly limited, and examples thereof include a spray method in which the sizing agent is made into an aqueous solution and sprayed onto the target, and a dipping method in which the target is immersed in an aqueous solution of the sizing agent.

[0038] The adhesion step may be a step of adhering a sizing agent to the (B) carbon fiber and (C) carbon powder. For example, when a sizing agent is applied to recycled carbon fiber having a resin carbide attached to its surface, the sizing agent adheres to both the recycled carbon fiber and the resin carbide.

[0039] For example, the method for producing a biomass resin composition may include a cutting step of cutting the carbon fibers (B). In this case, the kneading step is performed after the cutting step. If the adhesion step is further performed, the adhesion step may be performed before or after the cutting step.

[0040] [Kneading process] The kneading step will now be described in more detail. In the kneading step, the (A) biomass resin, the (B) carbon fiber, and the (C) carbon powder may be fed into the kneader at the same time, or each component may be fed at a different time. The "simultaneous" mentioned above can tolerate a delay of a few seconds.

[0041] As a specific example, a manufacturing method using an extruder as a kneader will be described below. Three manufacturing methods, [Method 1], [Method 2], and [Method 3], will be exemplified. Below, an example will be described in which recycled carbon fiber is used as (B) carbon fiber. That is, when (B) carbon fiber is fed into the kneader, (C) carbon powder adhering to (B) carbon fiber is also fed into the kneader at the same time.

[0042] [Method 1] FIG. 1 shows an extruder 110 used in method 1. The extruder 110 includes a cylinder 21. The extruder 110 includes a screw 22 housed in the cylinder 21. The extruder 110 includes a heater 41. The extruder 110 includes an inlet 31 for feeding raw materials into the cylinder 21. The inlet 31 is provided with a measuring device for controlling the amount of material fed. The extruder 110 includes an extrusion outlet 33 for discharging the kneaded material from the cylinder 21. FIG. 1 shows an arrow indicating an extrusion direction X, which is a direction in which the kneaded material is fed by the rotation of the screw 22.

[0043] In method 1, (A) biomass resin and (B) carbon fiber are charged from the charging port 31. That is, in method 1, (A) biomass resin, (B) carbon fiber, and (C) carbon powder are charged simultaneously.

[0044] The extruder 110 heats and kneads the components fed into the cylinder 21 . The (A) biomass resin fed into the cylinder 21 is heated and melted while being fed in the extrusion direction X. Fig. 1 diagrammatically shows a solid (A) biomass resin P1 and a molten (A) biomass resin P2.

[0045] Shear stress and compression force act on the (B) carbon fibers fed into the cylinder 21 as they are fed in the extrusion direction X. The shear stress acting on the (B) carbon fibers advances the opening of the (B) carbon fibers. The compression force acts like three-point bending in response to contact between the (A) biomass resin and the (B) carbon fibers. This advances the breakage of the (B) carbon fibers.

[0046] [Method 2] 2 shows an extruder 210 used in method 2. The extruder 210 differs from the extruder 110 in that the extruder 210 has two input ports. The same reference numerals are used for the components common to the extruder 110, and the description thereof will be omitted as appropriate.

[0047] The extruder 210 includes a first input port 231 and a second input port 232. The first input port 231 is disposed at a position similar to that of the input port 31 of the extruder 110 shown in Fig. 1. The second input port 232 is disposed downstream of the first input port 231, that is, between the first input port 231 and the extrusion port 33. The first input port 231 and the second input port 232 are each provided with a measuring instrument similar to that of the input port 31.

[0048] In method 2, (A) biomass resin is charged from the first charging port 231. In method 2, (B) carbon fiber is charged from the second charging port 232. In the extruder 210, the positions of the first charging port 231 and the second charging port 232 are set so that the (B) carbon fiber is charged after the (A) biomass resin charged from the first charging port 231 starts to melt. That is, in method 2, (B) carbon fiber is charged into a kneader that contains the molten material P2 obtained by heating and melting the (A) biomass resin and the solid material P1 of the (A) biomass resin.

[0049] In method 2, the kneading step can be said to include the following first and second kneading steps. The first kneading step refers to a step of kneading (A) biomass resin by feeding the (A) biomass resin from the first feeding port 231. The second kneading step refers to a step of kneading (A) biomass resin molten material P2, (A) biomass resin solid material P1, and (B) carbon fiber by feeding (B) carbon fiber from the second feeding port 232.

[0050] The extruder 210 heats and kneads the components fed into the cylinder 21 . Shear stress and compression force act on the (B) carbon fibers fed into the cylinder 21 as they are fed in the extrusion direction X. The shear stress acting on the (B) carbon fibers advances the opening of the (B) carbon fibers. In method 2, from the moment the (B) carbon fibers are fed, molten material P2 can be interposed between the (B) carbon fibers and the (A) biomass resin solid P1. Therefore, the compression force acts on the (B) carbon fibers as hydrostatic pressure due to the presence of molten material P2. This suppresses breakage of the (B) carbon fibers compared to method 1.

[0051] [Method 3] 3 shows an extruder 310 used in method 3. The position of the inlet of the extruder 310 is different from that of the extruder 210. The same reference numerals are used for the components common to the extruder 210, and the description thereof will be omitted as appropriate.

[0052] The extruder 310 includes a first input port 331 and a second input port 332. The first input port 331 is disposed at a position similar to that of the first input port 231 of the extruder 210 shown in FIG. 2. The second input port 332 is disposed downstream of the first input port 331, that is, between the first input port 331 and the extrusion port 33. As will be described in detail later, the second input port 332 is disposed further downstream of the second input port 232 of the extruder 210 shown in FIG. 2, that is, at a position closer to the extrusion port 33.

[0053] In an extruder having multiple input ports, such as extruder 310, the positions of the input ports may be changed as appropriate. In method 3, (A) biomass resin is charged from the first charging port 331. In method 3, (B) carbon fiber is charged from the second charging port 332. The positions of the first charging port 331 and the second charging port 332 of the extruder 310 are set so that the (B) carbon fiber is charged after the melting of the (A) biomass resin charged from the first charging port 331 has progressed more than in method 2. For example, the positions of the first charging port 331 and the second charging port 332 are set so that the (B) carbon fiber is charged after all of the (A) biomass resin has melted. That is, in method 3, (B) carbon fiber is charged into a kneader containing a molten material P2 obtained by heating and melting the (A) biomass resin.

[0054] In method 3, the kneading step can be said to include the following 1A kneading step and 2A kneading step. The 1A kneading step is a step of kneading (A) biomass resin by feeding the (A) biomass resin from the first feeding port 331. The 2A kneading step is a step of kneading the (A) biomass resin melt P2 with the (B) carbon fiber by feeding the (B) carbon fiber from the second feeding port 332.

[0055] The extruder 310 heats and kneads the components fed into the cylinder 21 . Shear stress acts on the (B) carbon fibers fed into the cylinder 21 as they are fed in the extrusion direction X. In method 3, the viscosity of the molten material P2 at the time the (B) carbon fibers are fed is lower than in method 2. For this reason, the shear stress acting on the (B) carbon fibers is likely to be weaker than in method 2. As a result, the opening of the (B) carbon fibers is less likely to proceed. Furthermore, if the melting of the (A) biomass resin has progressed more than in method 2 at the time the (B) carbon fibers are fed, compressive force is less likely to act, and therefore breakage of the (B) carbon fibers is less likely to occur.

[0056] <Molded products> The biomass resin composition can be used to produce a molded article made of the biomass resin composition. The method for producing the molded product is not particularly limited, and any known method can be used, such as press molding, injection molding, gas-assisted injection molding, welding molding, extrusion molding, blow molding, film molding, blow molding, multi-layer molding, and melt spinning.

[0057] The crystallinity of the molded article is, for example, preferably 20% or more, more preferably 25% or more. The upper limit of the crystallinity of the molded article is not particularly limited, but is, for example, 95%. The crystallinity of the molded article can be measured by a known method. For example, as described below, the crystallinity can be calculated using a differential scanning calorimeter (DSC).

[0058] The use of the molded article made of the biomass resin composition is not particularly limited, and examples of the use of the molded article include various parts for automobiles, electrical and electronics, industrial materials, industrial materials, daily necessities and household goods, etc.

[0059] <Action and Effects> The operation of this embodiment will be described. By using the biomass resin composition of the present embodiment, a molded article in which the biomass resin is crystallized can be obtained.

[0060] The effects of this embodiment will be described. (1) Biodegradable biomass resins have been known for some time. It can be said that biodegradable biomass resins have a reduced stability of the material while being biodegradable. For this reason, biodegradable biomass resins tend to have low mechanical strength and low durability. Even non-biodegradable biomass resins have the problem of being hard and brittle and having low impact resistance because they do not have a rigid molecular structure. In addition, biomass resins are composed mainly of carbon, oxygen, and hydrogen, and therefore are easily combusted. Due to issues with flame retardancy and heat resistance, biomass resins are not easily adopted for applications that require flame retardancy and heat resistance.

[0061] In contrast, according to the present embodiment, a molded article can be obtained by crystallizing the biomass resin, which is a crystalline resin. By crystallizing the biomass resin, which is a matrix component, the molded article can be given high heat resistance. Furthermore, since the biomass resin composition contains carbon fiber, the molded article can be given high mechanical properties. That is, by crystallizing the biomass resin, which is a matrix component of a molded article made of a biomass resin composition containing carbon fiber, the mechanical properties can be improved and the heat resistance can be improved.

[0062] (2) Resin charcoal is attached to the surface of recycled carbon fiber recovered from raw materials for recycling. In the biomass resin composition of this embodiment, by using recycled carbon fiber with resin charcoal attached, it is possible to suppress the formation of clusters of the resin charcoal, which is carbon powder. If the carbon powder forms clusters, it is considered that the effect of the carbon powder in promoting the crystallization of the biomass resin is reduced. In contrast, by suppressing the cluster formation of the carbon powder, it is possible to favorably promote the crystallization of the biomass resin.

[0063] (3) For example, when the carbon fibers contained in the raw material for recycling are long fibers, the recycled carbon fibers are obtained in a state where the fibers are aligned in one direction. By using such recycled carbon fibers, it is easy to cut the fibers to a desired length. In other words, by using recycled carbon fibers recovered from raw materials for recycling that contain long carbon fibers, it is easy to align the fiber lengths of the carbon fibers to a predetermined length.

[0064] In addition, in recycled carbon fibers recovered from raw materials for recycling containing long carbon fibers, the aligned carbon fibers are fixed together by the resin carbide. The carbon fibers are not easily disintegrated and do not easily scatter, making them easy to handle.

[0065] (4) For example, on the surface of recycled carbon fibers obtained by recycling long-fiber prepreg products, carbon powder is uniformly dispersed and adhered without agglomeration. By using recycled carbon fibers with carbon powder attached in a dispersed state in this way, the carbon powder can be dispersed uniformly in the biomass resin matrix component without agglomeration. Dispersing the carbon powder can further suppress the formation of carbon powder clusters. Carbon powder that is uniformly dispersed in the molten crystalline resin without agglomeration can easily become crystal nuclei, promoting the crystallization of the crystalline resin.

[0066] (5) When producing a molded article, a molded article in which the biomass resin is crystallized can be produced without performing an annealing step after a molding step such as injection molding. (6) Since the carbon powder can promote the crystallization of biomass resin, it is possible to produce molded products in which the biomass resin is crystallized without the need to add a separate crystallization promoter.

[0067] (7) When carbon fibers are kneaded, the carbon fibers are opened by the kneading. When carbon fibers with carbon powder attached thereto are opened, the carbon powder may come off the carbon fibers. According to the manufacturing method of the present embodiment, the degree of opening of the carbon fibers can be adjusted by the timing of feeding the carbon fibers into the kneader. By adjusting the degree of opening of the carbon fibers, the degree of dispersion of the carbon powder can be adjusted.

[0068] (8) As in [Method 2] above, if carbon fibers are added when the biomass resin begins to melt, the molten resin will envelop the carbon fibers. This can prevent unnecessary shear stress from being applied to the carbon fibers, and therefore prevent the carbon fibers from being damaged during kneading. Furthermore, as the carbon fibers are opened in the viscous fluid atmosphere, the carbon powder separated from the carbon fibers can be prevented from agglomerating. This can prevent the carbon powder from forming clusters.

[0069] (9) The addition of a sizing agent improves the adhesion between the carbon fibers and the matrix components, thereby improving the strength of the molded product. (10) A large amount of energy is required to produce carbon fiber. Furthermore, the manufacturing process of carbon fiber is complicated. For this reason, the manufacturing cost of carbon fiber tends to be high, and the manufacturing cost of resin compositions and molded products containing carbon fiber tends to be high. In this regard, the use of recycled carbon fiber can reduce manufacturing costs.

[0070] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0071] In the above embodiment, the method for producing a biomass resin composition is exemplified by adding the carbon powder (C) as the resin char adhering to the recycled carbon fiber. Alternatively, the carbon powder (C) may be added alone.

[0072] For example, carbon fibers not having carbon powder attached thereto and carbon powder can be charged into a kneader and kneaded together. In this case, the carbon fibers and the carbon powder may be charged at the same time, or the timing of charging the carbon fibers and the timing of charging the carbon powder may be different.

[0073] Examples of carbon fibers that do not have carbon powder attached thereto include new carbon fibers, recycled carbon fibers from which residues have been removed from the surface, and recycled carbon fibers in which the generation of residues has been suppressed during the carbon fiber recovery process.

[0074] In the above embodiment, an example of producing a molding resin material using a kneader is shown. Alternatively, a molded product can be produced by supplying a kneaded product obtained from the kneader to a molding machine. In other words, a molded product can be produced from the kneaded product without first turning the kneaded product into a molding resin material such as pellets. EXAMPLES

[0075] The molded article made of the biomass resin composition will be described in more detail with reference to the following examples. Note that the biomass resin composition, the method for producing the biomass resin composition, and the molded article are not limited to the configurations described in the examples.

[0076] <Production of Molded Products> Molded articles were produced in Example 1, Example 2, and Comparative Example 1. Table 1 shows the components and amounts contained in the molding resin material used in each molded article.

[0077] [Table 1] Comparative Example 1 The molded product was manufactured by injection molding using PLA resin material.

[0078] Example 1 (A) PLA resin was used as the biomass resin. (B) Recycled carbon fiber was used as the carbon fiber. (B) The content of carbon fiber was 15 parts by mass per 100 parts by mass of (A) biomass resin. (C) The content of carbon powder was 15 parts by mass per 100 parts by mass of (B) carbon fiber.

[0079] A kneading step was carried out using an extruder 210 illustrated in FIG. 2, and a biomass resin composition was obtained as pellets. That is, the method 2 described in the above embodiment was adopted. Before carrying out the kneading step, an attachment step was carried out in which a sizing agent was attached to the (B) carbon fiber having (C) carbon powder attached thereto. Using the produced pellets, a molded product was produced by injection molding.

[0080] Example 2 The content of (B) carbon fiber was changed to 20 parts by mass relative to 100 parts by mass of (A) biomass resin, and pellets were produced in the same manner as in Example 1. The content of (C) carbon powder was 15 parts by mass relative to 100 parts by mass of (B) carbon fiber. Using the produced pellets, a molded product was produced in the same manner as in Example 1.

[0081] Evaluation Test Tests were carried out to evaluate the tensile strength, impact strength, and crystallinity of the molded articles of Example 1, Example 2, and Comparative Example 1. The evaluation methods and evaluation criteria are explained below. The evaluation results are shown in Table 1.

[0082] [Tensile strength] The tensile strength of each molded product was measured by a method conforming to JIS K 7161. For the measurement, a universal tensile tester (Shimadzu Corporation, Autograph AG-IS 250 kN) was used.

[0083] [Evaluation Criteria for Tensile Strength] ◎ (Excellent): Tensile strength is 150 MPa or more. ◯ (Good): The tensile strength is 100 MPa or more and less than 150 MPa. × (unacceptable): The tensile strength is less than 100 MPa.

[0084] [Impact strength] The impact strength of each molded article was measured by a method conforming to JIS K 7111. For the measurement, a Charpy impact tester (Impact Tester IT, manufactured by Toyo Seiki Seisakusho Co., Ltd.) was used.

[0085] [Impact strength evaluation criteria] ○(Good): Impact strength is 3.2kJ / m 2 That's all. × (Not acceptable): Impact strength is 3.2kJ / m 2 is less than.

[0086] [Crystallization degree] The crystallinity of each molded article was measured by a well-known method of measuring the heat of fusion of crystals by a differential scanning calorimeter (DSC).

[0087] [Criteria for evaluation of crystallinity] ◯ (Good): The crystallinity is 20% or more. × (unacceptable): The crystallinity is less than 20%.

[0088] Evaluation Results As shown in Table 1, in Examples 1 and 2, the tensile strength, impact strength, and crystallinity were all evaluated as good or better. In particular, Example 1 showed higher tensile strength. In contrast, in Comparative Example 1, the tensile strength, impact strength, and crystallinity were all unrecognizable. From these results, it can be seen that the molded articles of Examples 1 and 2 have improved tensile strength, impact strength, and crystallinity compared to the molded article of Comparative Example 1, which is composed of PLA resin alone.

[0089] Since the higher the crystallinity of a crystallized resin, the more excellent its heat resistance is, the molded articles of Examples 1 and 2 have high heat resistance. That is, a molded article made of a biomass resin composition containing (A) biomass resin, which is a crystalline resin containing a biological component, (B) carbon fiber, and (C) carbon powder, in which the content of (B) carbon fiber is 10 parts by mass or more and 50 parts by mass or less per 100 parts by mass of (A) biomass resin, has excellent mechanical properties and high heat resistance. [Industrial Applicability]

[0090] INDUSTRIAL APPLICABILITY The present invention is capable of producing molded articles having good heat resistance, and is therefore useful for molding various parts for automobiles, electrical and electronic equipment, industrial materials, industrial materials, daily necessities and household goods, etc. [Explanation of symbols]

[0091] 110...Extruder 21...Cylinder 22...Screw 31…Inlet 33...Extrusion port 41…Heater 210...Extruder 231…1st input port 232…Second input port 310…Extruder 331…1st input port 332…Second input port X: Extrusion direction

Claims

1. (A) biomass resin, (B) carbon fiber, and (C) carbon powder; The (A) biomass resin is a crystalline resin containing a component derived from a living organism, The content of the (B) carbon fiber is 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the (A) biomass resin. Biomass resin composition.

2. The (B) carbon fiber is a recycled carbon fiber recovered from a raw material for recycling, The carbon powder (C) is a carbide obtained as a product derived from the resin contained in the raw material for recycling, together with the recycled carbon fibers recovered from the raw material for recycling, and attached to the surface of the recycled carbon fibers. The biomass resin composition according to claim 1.

3. The content of the carbon powder (C) is 10 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the carbon fiber (B). The biomass resin composition according to claim 1.

4. The (B) carbon fiber is a sizing-agent-attached carbon fiber to which a sizing agent is attached, The carbon powder (C) is a resin carbide having a sizing agent attached thereto. The biomass resin composition according to claim 1.

5. A method for producing the biomass resin composition according to any one of claims 1 to 3, A step of adhering a sizing agent to the (B) carbon fiber and the (C) carbon powder; A kneading step of kneading the (A) biomass resin, the (B) carbon fiber, and the (C) carbon powder using a kneader while heating, The kneading step is carried out after the adhesion step. A method for producing a biomass resin composition.

6. A method for producing the biomass resin composition according to any one of claims 1 to 4, The method includes a kneading step of kneading the (A) biomass resin, the (B) carbon fiber, and the (C) carbon powder with a kneader while heating, The kneading step includes: A first kneading step of feeding the (A) biomass resin into the kneader and kneading the (A) biomass resin; a second kneading step of introducing the (B) carbon fiber into the kneader containing the molten (A) biomass resin heated and melted by the first kneading step and the solid (A) biomass resin, and kneading the molten (A), the solid (A) biomass resin, and the carbon fiber (B). A method for producing a biomass resin composition.

7. A molded article made of the biomass resin composition according to any one of claims 1 to 4.

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