JP7462202B2 - Manufacturing method of molding material, manufacturing method of molded body, and vehicle - Google Patents

Description

The present disclosure generally relates to a method for producing a molding material, a method for producing a molded body, and a vehicle, and more specifically, to a method for producing a molding material that mixes a first powder and a second powder, a method for producing a molded body, and a vehicle.

Patent Document 1 discloses a molding material containing carbon fiber and polypropylene. It is expected that this molding material will increase the strength of the molded body by blending carbon fiber with polypropylene. In general, resin molded bodies reinforced with carbon fiber are called carbon fiber reinforced thermoplastics (CFRTP).

JP 2017-075290 A

However, there was a problem in that it was difficult to disperse carbon fibers in molten thermoplastic resin.

The present disclosure aims to provide a method for producing a molding material that makes it easy to disperse carbon fibers in a thermoplastic resin.

The present disclosure also aims to provide a method for manufacturing a molded body using a molding material obtained by the molding material manufacturing method, and a vehicle.

A method for producing a molding material according to one embodiment of the present disclosure includes mixing a first powdered material with a second powdered material. The first powdered material includes a first thermoplastic resin. The second powdered material includes a second thermoplastic resin and carbon fibers. The carbon fibers are impregnated with the second thermoplastic resin.

In one embodiment of the method for producing a molded body according to the present disclosure, a molding material obtained by the method for producing a molding material according to the present disclosure is heated to melt a first thermoplastic resin and a second thermoplastic resin, which are then kneaded and molded.

A vehicle according to one aspect of the present disclosure includes a molded body obtained by the molded body manufacturing method according to the present disclosure, and a vehicle body.

The present disclosure has the advantage that carbon fibers can be easily dispersed in thermoplastic resin.

Fig. 1A is a schematic diagram showing a method for producing a molding material according to the present embodiment, and Fig. 1B is a schematic diagram showing particles constituting a second powder or granule. FIG. 2 is a diagram showing a schematic view of the molten state of the molding material obtained by the method for producing a molding material according to this embodiment. FIG. 3 is a schematic diagram showing a vehicle according to this embodiment.

(Embodiment 1)
(1) Overview In the manufacturing method of the molding material 3 according to this embodiment, as shown in Fig. 1, a first powder granular material 1 and a second powder granular material 2 are mixed. The first powder granular material 1 includes a first thermoplastic resin 13. The second powder granular material 2 includes a second thermoplastic resin 23 and carbon fibers 22. The carbon fibers 22 are impregnated with the second thermoplastic resin 23.

In the manufacturing method of the molding material 3 according to this embodiment, the carbon fibers 22 are contained in the second powder granules 2 before being mixed with the first thermoplastic resin 13. Then, the second powder granules 2 containing the carbon fibers 22 are mixed with the first powder granules 1. Therefore, the dispersibility of the carbon fibers 22 in the first thermoplastic resin 13 can be improved compared to the case where the carbon fibers are directly mixed with the molten thermoplastic resin. Therefore, it becomes easier to homogenize the physical properties and the appearance of the molded body 100 obtained by molding the molding material 3.

In addition, in the molded body 100 obtained by molding the molding material 3, when the second thermoplastic resin 23 is present in all or part between the first thermoplastic resin 13 and the carbon fiber 22, the adhesion between the first thermoplastic resin 13 and the carbon fiber 22 can be improved by the second thermoplastic resin 23, and physical properties such as strength and rigidity are improved compared to a molded body made of the first thermoplastic resin and carbon fiber.

When a molding material containing only a first thermoplastic resin and carbon fiber is molded, the dispersion of the carbon fiber in the first thermoplastic resin may be insufficient, resulting in insufficient adhesion between the first thermoplastic resin and the carbon fiber. In such cases, the strength, rigidity, and other physical properties of the molded body may not be sufficiently improved. On the other hand, if the amount of carbon fiber is increased to increase the rigidity of the molded body, the weight of the molded body may increase. In contrast, the molding material 3 obtained in this embodiment has the second thermoplastic resin 23 present at least partially between the first thermoplastic resin 13 and the carbon fiber 22. As a result, the strength, rigidity, and other physical properties are improved compared to a molded body made of the first thermoplastic resin and carbon fiber.

(2) Details (2-1) Manufacturing Method of Molding Material In the manufacturing method of the molding material 3 according to the present embodiment, as shown in FIG. 1A, a first powdery or granular material 1 and a second powdery or granular material 2 are mixed. In the present disclosure, the powdery or granular material includes one or both of a powder and a granular material. In the present disclosure, the powder and the granular material include a plurality of particles. That is, the first powdery or granular material 1 in the present embodiment is an aggregate of a plurality of particles 11. Also, the second powdery or granular material 2 in the present embodiment is an aggregate of a plurality of particles 21. In the present disclosure, a particle having a particle diameter of 10 ^-4 m or more and 10 ^-1 m or less is called a granular material, and a particle having a particle diameter of 10 ^-9 m or more and less than 10 ^-4 m is called a powder. In the present disclosure, the particle diameter is measured by, for example, a dynamic light scattering method, a laser diffraction method, a centrifugal sedimentation method, a FFF method, an electric detector method, or the like.

In the present disclosure, when mixing the first powdered or granular material 1 and the second powdered or granular material 2, it is preferable to dry blend them. Dry blending refers to mixing in a dry state. Here, the dry state refers to a state that does not contain any water or solvent, but a state that unavoidably contains small amounts of water and solvent is also called a dry state. In addition, a case where a small amount of water and solvent is added for reasons such as improving the uniformity of the mixed state of the first powdered or granular material 1 and the second powdered or granular material 2 is also called a dry state.

In the present disclosure, dry blending refers to mixing the first powdered granular material 1 and the second powdered granular material 2 in an unmolten state. However, dry blending may be performed in a state in which the first powdered granular material 1 and the second powdered granular material 2 are inevitably heated and at least one of the first powdered granular material 1 and the second powdered granular material 2 is slightly melted. Furthermore, dry blending may be performed by heating the first powdered granular material 1 and the second powdered granular material 2 so that at least one of them is slightly melted, for example, to improve the uniformity of the mixed state of the first powdered granular material 1 and the second powdered granular material 2.

<First powder and granular material>
As shown in FIG. 1A, the first powder granule 1 contains a first thermoplastic resin 13. That is, the first powder granule 1 is an aggregate of a plurality of particles 11 containing the first thermoplastic resin 13. The particles 11 contained in the first powder granule 1 may be composed of only the first thermoplastic resin 13, or may contain other thermoplastic resins or thermosetting resins. The particles 11 contained in the first powder granule 1 may contain other components such as inevitably contained impurities, antioxidants, colorants, inorganic fillers, ultraviolet absorbers, and recycled materials. The first powder granule 1 may also contain particles containing thermoplastic resins or thermosetting resins other than the first thermoplastic resin 13. The first powder granule 1 may also contain other components such as inevitably contained impurities, antioxidants, colorants, inorganic fillers, ultraviolet absorbers, and recycled materials.

The first thermoplastic resin 13 is a resin that can be molded by a molding method such as injection molding, compression molding, extrusion molding, or blow molding. In this embodiment, the first thermoplastic resin 13 includes an olefin-based resin. The olefin-based resin can include, for example, one or more materials selected from the group consisting of polyethylene, polypropylene, and polybutylene.

Examples of polyethylene include low density polyethylene (LDPE), medium density polyethylene, high density polyethylene (HDPE), ethylene homopolymer, ethylene and α-olefin copolymer, etc. Polyethylene can include one or more of these materials. Examples of polypropylene include propylene homopolymer (homopolypropylene), propylene-containing random copolymer (random polypropylene), propylene-containing block copolymer (block propylene), isotactic polypropylene, syndiotactic polypropylene, etc. Polypropylene can include one or more of these materials.

The proportion of the olefin-based resin in the first thermoplastic resin 13 is preferably 80% by weight or more, more preferably 90% by weight or more, and even more preferably 100% by weight. In other words, the entire first thermoplastic resin 13 may be an olefin-based resin. The olefin-based resin preferably contains polypropylene. In this case, the moldability of the molding material 3 can be improved, and the molding material 3 is particularly easy to apply to injection molding.

The shape of the particles constituting the first powder or granular material 1 is not particularly limited, and may be, for example, spherical, cylindrical, conical, rectangular, cubic, polyhedral, pellet-like, flaky, crushed, fibrous, film-like, or chip-like.

<Second powder/granular material>
As shown in FIG. 1A and FIG. 1B, the second powder granule 2 includes a second thermoplastic resin 23 and carbon fibers 22. That is, the second powder granule 2 is an aggregate of a plurality of particles 21 including the second thermoplastic resin 23 and the carbon fibers 22. The particles 21 included in the second powder granule 2 may be composed only of the second thermoplastic resin 23 and the carbon fibers 22, or may include other thermoplastic resins or thermosetting resins. The particles 21 included in the second powder granule 2 may include other components such as impurities, antioxidants, colorants, inorganic fillers, ultraviolet absorbers, and recycled materials that are inevitably included. The second powder granule 2 may also contain particles including thermoplastic resins or thermosetting resins other than the second thermoplastic resin 23. The second powder granule 2 may also include other components such as impurities, antioxidants, colorants, inorganic fillers, ultraviolet absorbers, and recycled materials that are inevitably included.

The second thermoplastic resin 23 may be the same type of thermoplastic resin as the first thermoplastic resin 13, or may be a different type of thermoplastic resin. The same type of thermoplastic resin refers to thermoplastic resins with the same molecular structure and physical properties such as viscosity, and different types of thermoplastic resins refer to thermoplastic resins with different molecular structures or physical properties such as viscosity. If the first thermoplastic resin 13 and the second thermoplastic resin 23 are made of the same type of thermoplastic resin, it becomes easier to control the amount of impregnation of the first thermoplastic resin 13 and the second thermoplastic resin 23 into the carbon fiber 22. In addition, making the first thermoplastic resin 13 and the second thermoplastic resin 23 the same type is effective as a means of reducing the blending ratio of the carbon fiber 22 in the entire molding material.

In this embodiment, the second thermoplastic resin 23 includes a non-olefin resin. When the first thermoplastic resin 13 includes an olefin resin, the second thermoplastic resin 23 preferably includes a non-olefin resin. This allows the second thermoplastic resin 23, which has properties different from those of the first thermoplastic resin 13, to be present between the first thermoplastic resin 13 and the carbon fiber 22, and the second thermoplastic resin 23 tends to improve the adhesion between the first thermoplastic resin 13 and the carbon fiber 22. The non-olefin resin preferably includes a resin having thermoplasticity other than the olefin resin. The non-olefin resin may include, for example, one or more materials selected from the group consisting of thermoplastic epoxy resin, acrylic resin, polyester resin, polyamide resin, polycarbonate resin, and ABS resin.

In this embodiment, the non-olefin resin preferably includes a thermoplastic epoxy resin.
In this case, the adhesion between the first thermoplastic resin 13 and the carbon fibers 22 can be particularly improved, and the physical properties such as the strength or rigidity of the molded body 100 produced from the molding material 3 can be particularly improved. The thermoplastic epoxy resin is an epoxy resin that has thermoplasticity even after curing, and is a linear high molecular weight epoxy polymer. For this reason, the thermoplastic epoxy resin is preferably a resin whose shape can be changed by treatment such as heating and pressure after curing. In addition, since the thermoplastic epoxy resin has a low molecular weight and low viscosity before polymerization, it is easy to impregnate between the carbon fibers 22, and is easier to impregnate between the carbon fibers 22 than other general thermoplastic resins. The thermoplastic epoxy resin can be obtained, for example, by chain extension of a bifunctional epoxy compound and a bifunctional phenolic compound by an addition polymerization reaction accompanied by ring opening of the epoxy ring.

The second thermoplastic resin 23 may contain a lubricant. In particular, when the second thermoplastic resin 23 contains a lubricant, the ratio of the lubricant to the total amount of the second thermoplastic resin 23 is preferably 0.02% by weight or less, and more preferably 0.01% by weight or less. In this case, it is possible to suppress the occurrence of whitening on the surface of the molded body 100 produced from the molding material.

The carbon fiber 22 can be one or both of PAN-based carbon fiber made from acrylic fiber and pitch-based carbon fiber made from petroleum, coal, etc. From the viewpoint of the balance between strength and elastic modulus, PAN-based carbon fiber is preferred. The carbon fiber 22 can be any of untwisted yarn, twisted yarn, and untwisted yarn.

In this embodiment, carbon fibers 22 arranged in one direction and bundled are used. Here, carbon fibers arranged in one direction are those in which the fiber axis directions of multiple carbon fibers are aligned. In other words, the carbon fibers 22 are strands. The strands are formed by bundling multiple single fibers (filaments). In this embodiment, it is sufficient that two or more carbon fiber single fibers are bundled, and preferably, the carbon fibers 22 are formed by bundling 1,000 or more single fibers. It is more preferable that the number of single fibers in the carbon fibers 22 is 10,000 or more, and even more preferably 100,000 or more. The upper limit of the number of carbon fiber bundles is not particularly limited, but in the case of carbon fiber bundles that are not opened, it is about 1 million. In addition, in the case of opening a bundle of carbon fibers arranged in one direction and using it, the number may be even greater.

In this embodiment, when bundling two or more carbon fiber monofilaments, they may be bundled with a bundling agent, or they may be bundled without using a bundling agent. From the viewpoint of productivity, it is preferable to bundle them with a bundling agent. Bundling agents are called bundling agents, binders, sizing agents, etc., and are used to bundle the monofilaments. When using a bundling agent, it is preferable to use one that has high affinity with the second thermoplastic resin 23. In this case, the second thermoplastic resin 23 is easily impregnated into the bundle of carbon fibers 22, and it is easy to obtain a molded body 100 having excellent strength and stable strength. In this disclosure, the second thermoplastic resin 23 is different from the bundling agent, bundling agent, binder, and sizing agent. The bundling agent has the function of only bundling multiple monofilaments, but the second thermoplastic resin 23 also bears part of the physical properties such as the rigidity of the molded body 100. That is, the second thermoplastic resin 23, together with the first thermoplastic resin 13, constitutes the main part of the molded body 100 and ensures (bears) the physical properties such as strength and rigidity. On the other hand, sizing agents and other bundling agents do not act to ensure the physical properties of the molded body 100.

The second thermoplastic resin 23 is impregnated into the carbon fibers 22. That is, the particles 21 constituting the second powdered material 2 contain the second thermoplastic resin 23 and the carbon fibers 22, and the second thermoplastic resin 23 is impregnated into the carbon fibers 22. In this disclosure, impregnation refers to a state in which the second thermoplastic resin 23 is attached to the surface of the filaments constituting the carbon fibers 22, and a part of the second thermoplastic resin 23 penetrates between the adjacent filaments. Furthermore, in the disclosure, impregnation refers to a state in which the second thermoplastic resin 23 penetrates between the adjacent carbon fibers 22. In this embodiment, a bundle is formed by aligning a plurality of carbon fibers 22, and the bundle is immersed in the heat-molten second thermoplastic resin 23 or a solution that dissolves the second thermoplastic resin 23. As a result, the carbon fibers 22 are impregnated with the second thermoplastic resin 23.

In the second powder granule 2, the content ratio of the second thermoplastic resin 23 to the carbon fiber 22 is in the range of carbon fiber/(second thermoplastic resin + carbon fiber) = 20/100 to 80/100 (0.2 to 0.8) in volume ratio. That is, the volume of the carbon fiber 22 contained in the second powder granule 2 is in the range of 20% to 80% of the total volume of the second thermoplastic resin 23 and the carbon fiber 22 contained in the second powder granule 2. In this case, it is easy to ensure the moldability of the molding material while improving the rigidity of the molded body 100. In addition, in the second powder granule 2, the content ratio of the second thermoplastic resin 23 to the carbon fiber 22 is more preferably in the range of carbon fiber/(second thermoplastic resin + carbon fiber) = 20/100 to 60/100 (0.2 to 0.6) in volume ratio. More preferably, the carbon fiber/(second thermoplastic resin + carbon fiber) = 20/100 to 50/100 (0.2 to 0.5). In addition, in the second powder granule 2, the content ratio of the second thermoplastic resin 23 to the carbon fiber 22 is preferably in the range of carbon fiber/(second thermoplastic resin + carbon fiber) = 20/100 to 40/100 (0.2 to 0.4) in volume ratio. In addition, in the second powder granule 2, the content ratio of the second thermoplastic resin 23 to the carbon fiber 22 is preferably in the range of carbon fiber/(second thermoplastic resin + carbon fiber) = 30/100 to 40/100 (0.3 to 0.4) in volume ratio.

The carbon fibers 22 contained in the second powdered granular material 2 preferably have a length in the fiber axis direction of 1 mm or more and 500 mm or less. In this case, the deterioration of the strength of the second powdered granular material 2, such as fracture toughness, bending strength, impact resistance, and compressive strength, is reduced. In addition, if the length of the carbon fibers 22 in the fiber axis direction is less than 1 mm, it may be difficult to obtain the reinforcing effect of the molded body 100 by the carbon fibers 22. In addition, if the length of the carbon fibers 22 in the fiber axis direction exceeds 500 mm, the carbon fibers 22 may become entangled with each other, and the dispersibility of the carbon fibers 22 in the second powdered granular material 2, the molten molding material 3, and the molded body 100 may be easily reduced. The length of the carbon fibers 22 in the fiber axis direction is preferably 1 mm or more and 100 mm or less, more preferably 1 mm or more and 50 mm or less. In addition, the length of the carbon fibers 22 in the fiber axis direction is preferably 5 mm or more, more preferably 10 mm or more, and even more preferably 20 mm or more. It is more preferably 30 mm or more, more preferably 40 mm or more, and even more preferably more than 50 mm.

The second thermoplastic resin 23 is attached to at least a part of the outer surface of the carbon fiber 22 with a thickness of 10 μm or more. As shown in FIG. 1A, each of the particles 21 contained in the second powder 2 contains a plurality of carbon fibers 22 and the second thermoplastic resin 23, and the second thermoplastic resin 23 is attached to a part or the entire surface of each carbon fiber 22 with a thickness of 10 μm or more. As a result, in the molding material 3 melted during molding, the second thermoplastic resin 23 is easily interposed between the carbon fiber 22 and the first thermoplastic resin 13, improving the adhesion between the first thermoplastic resin 13, the carbon fiber 22, and the second thermoplastic resin 23. The second thermoplastic resin 23 is preferably attached to at least a part of the outer surface of the carbon fiber 22 with a thickness of 20 μm or more, and more preferably attached to a thickness of 30 μm or more. The second thermoplastic resin 23 is preferably attached to at least a part of the outer surface of the carbon fiber 22 with a thickness of 10 mm or less, and more preferably attached to a thickness of 5 mm or less.

<Molding material>
The molding material 3 can be produced by dry blending the first powder granule 1 and the second powder granule 2. The molding material 3 may contain components other than the first powder granule 1 and the second powder granule 2. For example, in addition to the first powder granule 1 and the second powder granule 2, the molding material 3 may contain a filler, a release agent, a colorant, a dye, an ultraviolet absorber, a foaming agent, a solvent, a thermoplastic resin other than the first and second thermoplastic resins, a thermosetting resin, and the like.

The blending ratio of the first powder 1 and the second powder 2 is in the range of 99/1 to 75/25 by weight (first powder/second powder). In this case, the moldability of the molding material 3 is not easily impaired, and the reinforcement effect of the molded body 100 by the carbon fibers 22 is easily obtained. It is more preferable that the blending ratio of the first powder 1 and the second powder 2 is in the range of 93/7 to 85/15 by weight (first powder/second powder).

The ratio of the carbon fiber 22 to the total amount of the molding material 3 is preferably 2% by weight or more, more preferably 3% by weight or more. That is, the ratio of the carbon fiber 22 to the molding material 3 is, in weight ratio, carbon fiber/molding material = 2/100 or more, preferably carbon fiber/molding material = 3/100 or more. In this case, the rigidity of the molded body 100 made from the molding material 3 is easily ensured by the carbon fiber 22. The ratio of the carbon fiber to the total amount of the molding material is preferably 75% by weight or less, more preferably 50% by weight or less, even more preferably 25% by weight or less, and particularly preferably 15% by weight or less. In this case, the rigidity of the molded body 100 is easily ensured while ensuring the moldability of the molding material 3. In particular, when the molding material 3 is injection molded, the ratio of the carbon fiber 22 to the total amount of the molding material 3 is preferably 15% by weight or less. In this case, the strength (weld strength) of the part where the molten molding materials 3 join together can be improved.

When mixing (dry blending) the first powder 1 and the second powder 2, the first powder 1 and the second powder 2 are measured and mixed (dry blended) so that they are mixed in the desired ratio. Dry blending may be performed using a batch mixer or an automatic metering mixer. In order to reduce the effect of moisture on the molding material 3, the molding material 3 may be dried at 80°C for about 3 to 4 hours after dry blending, but if the effect of moisture is small, drying is not necessary.

(2-2) Manufacturing Method of Molded Body In the manufacturing method of the molded body 100 according to the present embodiment, the molding material 3 is heated to melt the first thermoplastic resin 13 and the second thermoplastic resin 23, kneaded, and then molded. The molding material 3 can be molded by a method such as injection molding, compression molding, extrusion molding, and blow molding. Therefore, in the manufacturing method of the molded body 100, the molding material 3 can be injection molded, compression molded, extrusion molded, or blow molded to produce the molded body 100 from the molding material 3. Among these various molding methods, the manufacturing method of the molded body 100 according to the present embodiment is preferably performed by heating the molding material 3 to melt the first thermoplastic resin 13 and the second thermoplastic resin 23, kneading, and then injection molding.

Figure 2 shows a schematic diagram of the molding material 3 in the melted state in this embodiment. The melted molding material 3a is a viscous material having fluidity due to thermal melting of the first powder granule 1 and the second powder granule 2. The melted molding material 3a includes a resin region 31. In the resin region 31, the first thermoplastic resin 13 and the second thermoplastic resin 23 contained in the molding material 3 are mixed in a melted state. The carbon fibers 22 are dispersed in the resin region 31. The carbon fibers 22 include carbon fibers 22a whose entire surface is covered with the second thermoplastic resin 23, carbon fibers 22b whose part of the surface is covered with the second thermoplastic resin 23, and carbon fibers 22c whose entire surface is not covered with the second thermoplastic resin 23.

Here, the carbon fibers 22b and 22c, at least a part of whose surface is not covered with the second thermoplastic resin 23, are generated by melting and kneading the first thermoplastic resin 13 and the second thermoplastic resin 23 by heating the molding material 3. That is, a shear force caused by kneading acts on the molten second thermoplastic resin 23, and the molten second thermoplastic resin 23 peels off from the surface of the carbon fiber 22. The peeled second thermoplastic resin 23 mixes with the first thermoplastic resin 13 in the resin region 31. Therefore, when the shear force during kneading increases, the amount of carbon fibers 22c that are not covered with the second thermoplastic resin 23 increases. Conversely, when the shear force during kneading decreases, the amount of carbon fibers 22a that are covered with the second thermoplastic resin 23 increases.

In the carbon fibers 22a, 22b, at least a portion of the surface of which is covered with the second thermoplastic resin 23, the second thermoplastic resin 23 exists between the resin region 31 and the carbon fibers 22a, 22b. Therefore, in the molded body 100, the solidified or hardened portion of the second thermoplastic resin 23 exists at least partially between the solidified or hardened portion of the resin region 31 and the carbon fibers 22a, 22b. The solidified or hardened portion of the second thermoplastic resin 23 can improve the adhesion between the solidified or hardened portion of the resin region 31 and the carbon fibers 22a, 22b. This can improve the physical properties, such as the rigidity, of the molded body 100.

When the molding material 3 is injection molded, the molding conditions vary depending on the type of first thermoplastic resin 13, the type of second thermoplastic resin 23, the amount of carbon fiber 22, etc., but for example, the temperature at the nozzle tip of the cylinder can be set to about 180 to 240°C. Furthermore, when the molding material 3 is melted and kneaded in the cylinder of the injection molding machine, and the material with dispersed fibers (molten molding material 3) is injected and filled into a mold, the mold temperature can be, for example, about 20 to 50°C, but is not limited to this. The molding material 3 filled into the mold and injection molded is then cooled inside the mold and removed to become a product.

In the molded body 100, for example, when comparing the elastic modulus of the cured product (including the solidified product) of the second thermoplastic resin 23 and the cured product (including the solidified product) of the first thermoplastic resin 13, it is preferable that the relationship of the following formula (1) is satisfied.

Elastic modulus of the cured product of the first thermoplastic resin≦Elastic modulus of the cured product of the second thermoplastic resin (1)
That is, it is preferable that the molded body 100 obtained from the molding material 3 satisfies the above formula (1). In this way, by interposing the second thermoplastic resin having a higher elastic modulus than the cured product of the first thermoplastic resin at the interface between the first thermoplastic resin and the carbon fiber, it is possible to suppress buckling of the carbon fiber during molding of the molding material. Therefore, the stress generated during molding of the molding material can be dispersed in the fiber direction of the carbon fiber.

The use of the molded body 100 is not particularly limited, so long as it is in a field in which resin molded bodies are used. For example, the molded body 100 is preferably a bicycle part. In this case, examples of bicycle parts include baskets, chain cases, mudguards, and child seats. By producing these bicycle parts from the molded body 100, bicycle parts with excellent rigidity can be obtained and the bicycle parts can be made lighter. The molded body 100 is not limited to bicycle parts, and may be used, for example, in shopping baskets, logistics pallets, home appliances, and automobile parts.

In addition, the carbon fibers 22 are not exposed on the surface of the molded body 100, but this is not limited to the above. For example, a portion of the carbon fibers 22 may be exposed on the surface of the molded body 100.

(2-3) Vehicle The vehicle 200 according to this embodiment includes the molded body 100 and a vehicle body 210. In this disclosure, a bicycle is exemplified as the vehicle 200, but is not limited to this. The vehicle body (bicycle body) 210 is a basic part required for riding, and includes, for example, a frame, wheels, a saddle, handlebars, cranks, a chain, brakes, etc. The vehicle body 210 shown in FIG. 4 is an electrically assisted bicycle, and may further include a battery, a motor, etc.

The vehicle 200 includes a vehicle body 210, a basket 211, a chain case 212, a mudguard 213, and a child seat 214. The basket 211, the chain case 212, the mudguard 213, and the child seat 214 are each a vehicle part, and are attached to the vehicle body 210.

In this embodiment, for example, it is preferable that the basket 211 is the molded body 100. Also, for example, it is preferable that the chain case 212 is the molded body 100. Also, for example, it is preferable that the mudguard 213 is the molded body 100. Also, for example, it is preferable that the child seat 214 is the molded body 100. That is, the vehicle 200 of this embodiment includes the molded body 100 and the vehicle body 210 to which the molded body 100 is attached.

In the present embodiment, the vehicle 200 is made lighter by constructing vehicle components such as the basket 211, the chain case 212, the mudguard 213, and the child seat 214 from the molded body 100.

(Embodiment 2)
The method for producing a molding material 3 according to this embodiment differs from the method for producing a molding material according to the first embodiment in that a third powder or granular material is further included.

In the following, configurations similar to those in embodiment 1 will be denoted by the same reference numerals and explanations will be omitted as appropriate.

The configuration described in the second embodiment can be applied in appropriate combination with the configuration described in the first embodiment (including the modified example).

The third powder contains an acid-modified olefin resin. That is, the third powder is an aggregate of particles containing the acid-modified olefin resin. The third powder has a powder or granular form, similar to the first powder 1. The size of the particles containing the acid-modified olefin resin may be uniform or non-uniform.

The acid-modified olefin resin is an olefin resin modified with a resin modifier. Therefore, the acid-modified olefin resin has a functional group introduced by the resin modifier. The interaction between this functional group and the second thermoplastic resin can improve the adhesion between the first thermoplastic resin and the carbon fiber, and can improve the physical properties such as the rigidity of the molded body 100. Furthermore, the improved adhesion between the first thermoplastic resin and the carbon fiber improves the physical properties of the molded body 100, and therefore the amount of carbon fiber used can be reduced.

The acid-modified olefin resin is obtained by modifying (reacting) the same thermoplastic resin as the first thermoplastic resin or the second thermoplastic resin with a resin modifier. The resin modifier is not particularly limited, but preferably contains, for example, a polycarboxylic acid anhydride. As described above, since the olefin resin preferably contains polypropylene, the acid-modified olefin resin preferably contains a polycarboxylic acid anhydride-modified polypropylene. In this case, the adhesion between the first thermoplastic resin 13 and the carbon fiber can be further improved, and the dispersibility of the carbon fiber in the first thermoplastic resin can be improved. Therefore, the rigidity of the molded body 100 can be particularly improved.

Examples of polycarboxylic anhydrides include succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic anhydride, dichloromaleic anhydride, itaconic anhydride, tetrabromophthalic anhydride, pyromellitic anhydride, etc. The resin modifier can contain one or more of these materials. In particular, the resin modifier preferably contains maleic anhydride. That is, the polycarboxylic anhydride acid-modified polypropylene preferably contains maleic anhydride-modified polypropylene. In this case, the adhesion between the first thermoplastic resin and the carbon fiber can be particularly improved, and the dispersibility of the carbon fiber in the first thermoplastic resin can be particularly improved. As a result, the rigidity of the molded body 100 can be particularly improved. The ratio of the acid-modified olefin resin to the olefin resin in the first thermoplastic resin is preferably 0.3% by weight or more and preferably 10% by weight or less. In this case, the rigidity of the molded body 100 can be improved and the amount of carbon fiber used can be reduced.

When the first thermoplastic resin contains an acid-modified olefin resin modified with a resin modifier, the adhesion between the first thermoplastic resin and the carbon fiber can be particularly improved by the second thermoplastic resin and the functional group of the acid-modified olefin resin. The presence of the second thermoplastic resin in the molded body 100 can be confirmed by, for example, an SEM, FT-IR, or other device. In particular, when the molded body 100 contains polycarboxylic anhydride-modified polypropylene, the functional group introduced by the polycarboxylic anhydride and the thermoplastic epoxy resin are present between the first thermoplastic resin and the carbon fiber in the molded body 100. Therefore, the adhesion between the first thermoplastic resin and the carbon fiber can be particularly improved by the interaction between the functional group introduced by the polycarboxylic anhydride and the thermoplastic epoxy resin, and the physical properties of the molded body 100 can be particularly improved. In addition, the amount of carbon fiber can be reduced.

(Examples 1 to 14, Comparative Examples 1 and 2)
The components shown in Table 1 were dry-blended in the ratios shown in Table 1 to prepare molding materials of Examples 1 to 14 and Comparative Examples 1 and 2. Details of the components shown in Table 1 are as follows.

First powder: Polypropylene, manufactured by Sumitomo Chemical Co., Ltd., product name Block-PP AW564
Second powder: Thermoplastic epoxy resin + carbon fiber, thermoplastic epoxy resin-impregnated carbon fiber (manufactured by Komatsu Matere Co., Ltd., product name CABOKOMA KB chip, length in the linear axis direction of carbon fiber: 5 mm)
Third powder: Maleic anhydride modified polypropylene resin (Evaluation)
Molded articles were produced by injection molding the molding materials of Examples 1 to 14 and Comparative Examples 1 and 2. The molded articles of Examples 1 to 14 and Comparative Examples 1 and 2 were evaluated as follows.

(1) Tensile modulus Test pieces having a length of 165 mm (narrowest part 80 mm), a width of 10 mm, and a thickness of 2.8 mm were prepared from the molded bodies of Examples 1 to 14 and Comparative Examples 1 and 2. The tensile modulus of elasticity as defined in JIS K 7161-1 was measured using a tensile tester (Shimadzu Corporation Autograph Load Cell 2 kN). The results are shown in Table 1.

(2) Tensile strength of welded portion Test pieces 165 mm long (narrowest portion 80 mm), 10 mm wide, and 2.8 mm thick were prepared from the molded bodies of Examples 1 to 14 and Comparative Example 1 so that the joining portion (weld portion) of the molten molding material was located. The tensile strength of these test pieces was measured using a tensile tester (Shimadzu Corporation Autograph Load Cell 2kN) as specified in JIS K 7161-1. The results are shown in Table 1.

(3) Tensile strength Test pieces with a length of 165 mm (narrowest part 80 mm), width of 10 mm, and thickness of 2.8 mm were prepared from the molded bodies of Examples 1 to 14 and Comparative Examples 1 and 2. The tensile strength of these test pieces was measured using a tensile tester (Shimadzu Corporation Autograph Load Cell 2 kN) as specified in JIS K 7161-1. The results are shown in Table 1.

(summary)
As described above, the manufacturing method of the molding material (3) according to the first embodiment includes mixing the first powder or granular material (1) and the second powder or granular material (2). The first powder or granular material (1) includes a first thermoplastic resin (13). The second powder or granular material (2) includes a second thermoplastic resin (23) and carbon fibers (22). The carbon fibers (22) are impregnated with the second thermoplastic resin (23).

According to this embodiment, the dispersibility of the carbon fibers (22) in the first thermoplastic resin (13) can be improved compared to when the carbon fibers are directly mixed into the molten thermoplastic resin. This has the advantage that it is easier to homogenize the physical properties and appearance of the molded body (100) obtained by molding the molding material (3).

The manufacturing method of the molding material (3) according to the second aspect is the same as that of the first aspect, in which the blending ratio of the first powder/granular material (1) to the second powder/granular material (2) is in the range of 99/1 to 75/25 by weight.

According to this embodiment, the dispersibility of the carbon fibers (22) in the first thermoplastic resin (13) can be further improved. This has the advantage that it is easier to homogenize the physical properties and appearance of the molded body (100) obtained by molding the molding material (3).

The manufacturing method of the molding material (3) according to the third aspect is the first or second aspect, in which the second thermoplastic resin (23) is attached to at least a portion of the outer surface of the carbon fiber (22) with a thickness of 10 μm or more.

This embodiment has the advantage that the second thermoplastic resin (23) is easily interposed between the carbon fibers (22) and the first thermoplastic resin (13), and the carbon fibers (22) are easily dispersed in the first thermoplastic resin (13).

The method for producing the molding material (3) according to the fourth aspect is any one of the first to third aspects, in which the first thermoplastic resin (13) contains an olefin-based resin, and the second thermoplastic resin (23) contains a non-olefin-based resin.

This embodiment has the advantage that the molding material (3) can be easily molded by injection molding.

The manufacturing method of the molding material (3) according to the fifth aspect is the fourth aspect, in which the olefin-based resin contains polypropylene.

This embodiment has the advantage that the molding material (3) can be easily molded by injection molding.

The method for producing the molding material (3) according to the sixth aspect is the fourth or fifth aspect, in which the non-olefin resin includes a thermoplastic epoxy resin.

This embodiment has the advantage that the second thermoplastic resin (23) can easily impregnate the carbon fibers (22).

The method for producing the molding material (3) according to the seventh aspect is any one of the first to sixth aspects, and further includes a third powder or granular material containing an acid-modified olefin-based resin.

This embodiment has the advantage that the tensile strength of the molded body (100) obtained by molding the molding material (3) can be improved.

The manufacturing method for molding material (3) according to the eighth aspect is the seventh aspect, in which the acid-modified olefin resin includes polycarboxylic anhydride-modified polypropylene.

This embodiment has the advantage that the tensile strength of the molded body (100) obtained by molding the molding material (3) can be further improved.

The manufacturing method of the molding material (3) according to the ninth aspect is the eighth aspect, in which the polyvalent carboxylic acid anhydride-modified polypropylene includes maleic anhydride-modified polypropylene.

This embodiment has the advantage that the tensile strength of the molded body (100) obtained by molding the molding material (3) can be further improved.

The manufacturing method of the molding material (3) according to the tenth aspect is any one of the first to ninth aspects, in which the carbon fiber (22) has a length in the fiber axis direction of 1 mm or more and 500 mm or less.

This embodiment has the advantage that the dispersibility of the carbon fibers (22) is improved, making them easier to disperse.

The manufacturing method of the molding material (3) according to the eleventh aspect is any one of the first to tenth aspects, in which the carbon fiber (22) is formed by bundling 1,000 or more single fibers.

This embodiment has the advantage that the carbon fibers (22) can be easily impregnated with the second thermoplastic resin (23).

The method for producing the molding material (3) according to the twelfth aspect is any one of the first to eleventh aspects, in which the content ratio of the second thermoplastic resin (23) and the carbon fiber (22) in the second powder or granular material (2) is in the range of carbon fiber/(second thermoplastic resin+carbon fiber)=20/100 to 80/100 in volume ratio.

This embodiment has the advantage that the carbon fibers (22) can be easily impregnated with the second thermoplastic resin (23).

The method for producing the molded body (100) according to the thirteenth aspect involves heating the molding material (3) obtained in any one of the first to twelfth aspects to melt the first thermoplastic resin (13) and the second thermoplastic resin (23), kneading them, and then molding them.

This has the advantage that it is easier to obtain molded products with excellent physical properties such as strength and rigidity.

The method for producing the molded body (100) according to the fourteenth aspect involves heating the molding material (3) to melt the first thermoplastic resin (13) and the second thermoplastic resin (23), kneading them, and then injection molding them.

This embodiment has the advantage that it is easy to obtain molded articles with excellent physical properties such as strength and rigidity through injection molding.

The vehicle (200) according to the fifteenth aspect comprises a molded body (100) obtained in the thirteenth or fourteenth aspect and a vehicle body (210).

This embodiment has the advantage that it is easy to obtain a vehicle (200) equipped with a molded body (100) that has excellent physical properties such as strength and rigidity.

REFERENCE SIGNS LIST 1 First powder/granule material 13 First thermoplastic resin 2 Second powder/granule material 22 Carbon fiber 23 Second thermoplastic resin 3 Molding material 100 Molded body 200 Vehicle 210 Vehicle body

Claims (14)

A first powder or granular material containing a first thermoplastic resin;
A second powdery material containing a second thermoplastic resin and carbon fibers, the second thermoplastic resin being impregnated between the carbon fibers, is mixed with the second powdery material.
A method for producing a molding material, comprising the steps of:
the first thermoplastic resin comprises an olefin-based resin,
the second thermoplastic resin comprises a non-olefin resin;
The blending ratio of the first powder or granule to the second powder or granule is in the range of 99/1 to 75/25 by weight ratio (first powder or granule/second powder or granule).
A method for producing molding materials. A first powder or granular material containing a first thermoplastic resin;
A second powdery material containing a second thermoplastic resin and carbon fibers, the second thermoplastic resin being impregnated between the carbon fibers, is mixed with the second powdery material.
A method for producing a molding material, comprising the steps of:
the first thermoplastic resin comprises an olefin-based resin,
the second thermoplastic resin comprises a non-olefin resin;
The non-olefin resin comprises a thermoplastic epoxy resin.
A method for producing molding materials. A first powder or granular material containing a first thermoplastic resin;
A second powdery material containing a second thermoplastic resin and carbon fibers, the second thermoplastic resin being impregnated between the carbon fibers, is mixed with the second powdery material.
A method for producing a molding material, comprising the steps of:
the first thermoplastic resin comprises an olefin-based resin,
the second thermoplastic resin comprises a non-olefin resin;
Further comprising a third powder containing an acid-modified olefin resin;
A method for producing molding materials. The second thermoplastic resin penetrates between adjacent carbon fibers.
A method for producing the molding material according to any one of claims 1 to 3. The second thermoplastic resin is adhered to at least a part of the outer surface of the carbon fiber with a thickness of 10 μm or more.
A method for producing the molding material according to any one of claims 1 to 4. The olefin resin includes polypropylene.
A method for producing the molding material according to any one of claims 1 to 5. The acid-modified olefin resin includes a polyvalent carboxylic anhydride-modified polypropylene resin.
A method for producing the molding material according to claim 3 . The polyvalent carboxylic acid anhydride-modified polypropylene resin contains maleic anhydride-modified polypropylene.
A method for producing the molding material according to claim 7. The carbon fiber has a length in the fiber axial direction of 1 mm or more and 500 mm or less.
A method for producing the molding material according to any one of claims 1 to 8 . The carbon fiber is formed by bundling 1,000 or more single fibers.
A method for producing the molding material according to any one of claims 1 to 9. In the second powder or granule, the content ratio of the second thermoplastic resin to the carbon fiber is in the range of carbon fiber/(second thermoplastic resin+carbon fiber)=20/100 to 80/100 by volume ratio.
A method for producing the molding material according to any one of claims 1 to 10. The molding material obtained by the method for producing a molding material according to any one of claims 1 to 11 is heated to melt the first thermoplastic resin and the second thermoplastic resin, knead them, and then mold them.
A method for producing a molded body. The molding material is heated to melt and knead the first thermoplastic resin and the second thermoplastic resin, and then the mixture is injection molded.
A method for producing the molded article according to claim 12 . A molded body obtained by melting the first thermoplastic resin and the second thermoplastic resin by heating the molding material obtained by the method for producing a molding material according to claim 2 and kneading and molding the first thermoplastic resin and the second thermoplastic resin;
A vehicle body;
vehicle.

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