Manufacturing method of fiber reinforced plastic products

Abstract

The object of the present invention is to provide a product made of fiber-reinforced plastic which is lightweight and has excellent mechanical strength. [Solution] A method for manufacturing a fiber-reinforced plastic product having fibers and resin, the method comprising an additive manufacturing technology process, a first pressurizing process, and a second pressurizing process, in which the product obtained through the first pressurizing process is pressurized under heat to obtain a product whose volume is smaller than the volume of the product obtained by the first pressurizing process.

Description

[Technical field]

[0001] The present invention relates to a method for producing a fiber-reinforced plastic product. [Background technology]

[0002] Composite materials (fiber reinforced plastics (FRP (Fiber Reinforced Plastics): inorganic fiber reinforced plastics (e.g., carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP), other ceramic fiber reinforced plastics, metal fiber reinforced plastics), organic fiber reinforced plastics (e.g., aramid fiber reinforced plastics, natural fiber (e.g., cellulose fiber) reinforced plastics)) are attracting attention. For example, CFRP is attracting particular attention in the aerospace and automotive industries from the viewpoint of energy conservation through weight reduction. Of course, CFRP is also attracting attention in fields other than the above-mentioned industries. For example, it is used in products used in the leisure field.

[0003] Additive manufacturing technology (3D printer modeling technology) is known. This technology is explained as follows in the "2013 Patent Application Technology Trends Survey Report (Summary) 3D Printers": 3D printing (additive manufacturing technology) refers to the process of creating an object from a numerical representation of a three-dimensional shape by attaching material. In many cases, this is achieved by stacking layer on top of layer. The term 3D printer is used in contrast to the two-dimensional output on paper. In ASTM F2792-12a (Standard Terminology for Additive Manufacturing Technologies), the term additive manufacturing is used.

[0004] Thermoplastic resin laminated products made using additive manufacturing technology (3D printers) have become so popular that even individuals use them because of their characteristic of being able to freely create any shape they want. However, the mechanical properties of the resin itself are poor.

[0005] For example, MarkForged has proposed a 3D printer for CFRP. The material form includes fibers, and the concept of free shaping has expanded to the idea of ​​free fiber orientation. For this reason, additive manufacturing technology is being used to develop CFRP products in the aerospace and automotive industries. Additive manufacturing technology is also being used to develop CFRP products in the machine parts industry. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2016-78205 [Patent Document 2] Patent Publication No. 2016-172317 [Patent Document 3] Patent No. 6388238 [Patent Document 4] Patent No. 6507203 DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0007] It is difficult to manufacture fiber-reinforced plastic products with three-dimensional shapes (not sheet (flat) shapes) using additive manufacturing technology alone. In particular, when the amount of fiber is increased as much as possible (relatively decreasing the amount of resin) to improve mechanical strength, it is difficult to manufacture such products using additive manufacturing technology alone.

[0008] The problem that the present invention aims to solve is to provide a technology for producing products with high mechanical strength by using additive manufacturing technology, with a high fiber content (relatively low resin content). [Means for solving the problem]

[0009] The present invention relates to A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method includes an additive manufacturing step, a first pressurizing step, and a second pressurizing step; The second pressurizing step is a step in which the product obtained through the first pressurizing step is pressurized under heat, and a product having a volume smaller than that of the product obtained by the first pressurizing step is obtained. A method for manufacturing fiber-reinforced plastic products is proposed.

[0010] The present invention relates to A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method includes an additive manufacturing step, a first pressurizing step, and a second pressurizing step; The additive manufacturing process results in a product in which not all of the fibers are integrally bound by the resin and the fibers are partially separated. A method for manufacturing fiber-reinforced plastic products is proposed.

[0011] The present invention relates to A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method includes an additive manufacturing step, a first pressurizing step, and a second pressurizing step; The first pressing step is a step in which the product obtained through the additive manufacturing technology step is pressed, and most of the fibers are integrally bonded by the resin to obtain a product having a curved portion. A method for manufacturing fiber-reinforced plastic products is proposed.

[0012] The present invention relates to A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method includes an additive manufacturing step, a first pressurizing step, and a second pressurizing step; the additive manufacturing process results in a product in which not all of the fibers are integrally bound by the resin and the fibers are partially separated, The first pressing step is a step in which the product obtained through the additive manufacturing technology step is pressed, and most of the fibers are integrally bonded by the resin to obtain a product having a curved portion. A method for manufacturing fiber-reinforced plastic products is proposed.

[0013] The present invention relates to A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method includes an additive manufacturing step, a first pressurizing step, and a second pressurizing step; the additive manufacturing process results in a product in which not all of the fibers are integrally bound by the resin and the fibers are partially separated, The second pressurizing step is a step in which the product obtained through the first pressurizing step is pressurized under heat, and a product having a volume smaller than that of the product obtained by the first pressurizing step is obtained. A method for manufacturing fiber-reinforced plastic products is proposed.

[0014] The present invention relates to A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method includes an additive manufacturing step, a first pressurizing step, and a second pressurizing step; the additive manufacturing process results in a product in which not all of the fibers are integrally bound by the resin and the fibers are partially separated, The first pressurizing step is a step in which the product obtained through the additive manufacturing technology step is pressurized to obtain a product in which most of the fibers are integrally bonded by the resin and which has a curved portion; The second pressurizing step is a step in which the product obtained through the first pressurizing step is pressurized under heat, and a product having a volume smaller than that of the product obtained by the first pressurizing step is obtained. A method for manufacturing fiber-reinforced plastic products is proposed.

[0015] The present invention relates to A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method comprises an additive manufacturing step, a first pressing step, and a second pressing step; The ratio of the fiber to the resin in the additive manufacturing process is (volume of the resin) / (volume of the fiber+volume of the resin)≦55 / 100. A method for manufacturing fiber-reinforced plastic products is proposed.

[0016] The present invention relates to A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method comprises an additive manufacturing step, a first pressing step, and a second pressing step; The ratio of the fiber to the resin in the additive manufacturing process is 25 / 100≦(volume of the resin) / (volume of the fiber+volume of the resin). A method for manufacturing fiber-reinforced plastic products is proposed.

[0017] The present invention proposes a method for producing said fiber-reinforced plastic product, preferably in which the additive manufacturing technology process is a process for obtaining a product in which not all of the fibers are integrally bonded by the resin but the fibers are partially separated.

[0018] The present invention proposes a method for manufacturing the fiber-reinforced plastic product, preferably in which the first pressurizing step is a step in which the product obtained through the additive manufacturing technology step is pressurized, in which most of the fibers are integrally bonded by the resin and a product having a curved portion is obtained.

[0019] The present invention proposes a method for manufacturing the fiber-reinforced plastic product, preferably wherein the second pressurizing step is a step in which the product obtained through the first pressurizing step is pressurized under heat, and the volume of the obtained product is smaller than the volume of the product obtained by the first pressurizing step.

[0020] The present invention proposes a method for manufacturing the fiber-reinforced plastic product, preferably in which the first pressurizing step is a step in which multiple products obtained through the additive manufacturing technology step are stacked and pressurized.

[0021] The present invention proposes a method for producing the fiber-reinforced plastic product, wherein the pressure in the first pressurizing step is preferably lower than the pressure in the second pressurizing step.

[0022] The present invention proposes a method for producing the fiber-reinforced plastic product, which preferably satisfies (pressure in the first pressurizing step) / (pressure in the second pressurizing step)≦0.8.

[0023] The present invention proposes a method for producing the fiber-reinforced plastic product, which preferably satisfies (pressure in the first pressurizing step) / (pressure in the second pressurizing step)≦0.7.

[0024] The present invention proposes a method for producing the fiber-reinforced plastic product, which preferably satisfies (pressure in the first pressurizing step) / (pressure in the second pressurizing step)≦0.6.

[0025] The present invention proposes a method for producing the fiber-reinforced plastic product, which preferably satisfies (pressure in the first pressurizing step) / (pressure in the second pressurizing step)≦0.5.

[0026] The present invention proposes a method for producing the fiber-reinforced plastic product, which preferably satisfies (pressure in the first pressurizing step) / (pressure in the second pressurizing step)≦0.4.

[0027] The present invention proposes a method for producing the fiber-reinforced plastic product, which preferably satisfies 0.05≦(pressure in the first pressurizing step) / (pressure in the second pressurizing step).

[0028] The present invention proposes a method for producing the fiber-reinforced plastic product, which preferably satisfies 0.1≦(pressure in the first pressurizing step) / (pressure in the second pressurizing step).

[0029] The present invention proposes a method for producing the fiber-reinforced plastic product, preferably, wherein (volume of product obtained through the first pressurizing step) / (volume of product obtained through the second pressurizing step)≦2.5.

[0030] The present invention proposes a method for producing the fiber-reinforced plastic product, preferably, wherein (volume of the product obtained through the first pressurizing step) / (volume of the product obtained through the second pressurizing step)≦2.

[0031] The present invention proposes a method for producing the fiber-reinforced plastic product, preferably, wherein (volume of product obtained through the first pressurizing step) / (volume of product obtained through the second pressurizing step)≦1.5.

[0032] The present invention proposes a method for producing the fiber-reinforced plastic product, preferably, a method in which 1.05≦(volume of the product obtained through the first pressurizing step) / (volume of the product obtained through the second pressurizing step).

[0033] The present invention proposes a method for producing the fiber-reinforced plastic product, preferably such that 1.1≦(volume of the product obtained through the first pressurizing step) / (volume of the product obtained through the second pressurizing step).

[0034] The present invention proposes a method for producing a fiber-reinforced plastic product, preferably in which the pressure in the first pressurizing step is 0.8 kPa or more.

[0035] The present invention proposes a method for producing a fiber-reinforced plastic product, preferably in which the pressure in the first pressurizing step is 4 kPa or more.

[0036] The present invention is a method for producing a fiber-reinforced plastic product, and preferably, the pressure in the first pressurizing step is 8.0×10 5 We propose a method to reduce the pressure to less than kPa.

[0037] The present invention is a method for producing a fiber-reinforced plastic product, and preferably, the pressure in the first pressurizing step is 4.0×10 5 We propose a method to reduce the pressure to less than kPa.

[0038] The present invention proposes a method for producing a fiber-reinforced plastic product, preferably in which the pressure in the second pressurizing step is 1 kPa or more.

[0039] The present invention proposes a method for producing a fiber-reinforced plastic product, preferably in which the pressure in the second pressurizing step is 5 kPa or more.

[0040] The present invention is a method for producing a fiber-reinforced plastic product, and preferably, the pressure in the second pressurizing step is 1.0×10 6 We propose a method to reduce the pressure to less than kPa.

[0041] The present invention is a method for producing a fiber-reinforced plastic product, and preferably, the pressure in the second pressurizing step is 5.0×10 5 We propose a method to reduce the pressure to less than kPa.

[0042] The present invention proposes a method for producing the fiber-reinforced plastic product, wherein the first pressurizing step is preferably a step of pressurizing at a temperature equal to or higher than the melting temperature of the resin by the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation).

[0043] The present invention proposes a method for producing a fiber-reinforced plastic product, wherein the first pressurizing step is preferably a step in which pressure is applied at a temperature of {(melting temperature of the resin according to the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation))+10°C} or higher.

[0044] The present invention proposes a method for producing a fiber-reinforced plastic product, wherein the first pressurizing step is preferably a step in which pressure is applied at a temperature of {(melting temperature of the resin according to the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation))+20°C} or higher.

[0045] The present invention proposes a method for producing a fiber-reinforced plastic product, wherein the second pressurizing step is preferably a step of pressurizing at a temperature equal to or higher than the melting temperature of the resin by the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation).

[0046] The present invention proposes a method for producing a fiber-reinforced plastic product, wherein the second pressurizing step is preferably a step in which pressure is applied at a temperature of {(melting temperature of the resin according to the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation))+10°C} or higher.

[0047] The present invention proposes a method for producing a fiber-reinforced plastic product, wherein the second pressurizing step is preferably a step in which pressure is applied at a temperature of {(melting temperature of the resin according to the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation))+20°C} or higher.

[0048] The present invention proposes a method for producing a fiber-reinforced plastic product, in which the heating method in the first pressurizing step is preferably a non-contact heating method.

[0049] The present invention proposes a method for producing a fiber-reinforced plastic product, in which the heating method in the first pressurizing step is preferably an induction heating method.

[0050] The present invention proposes a method for producing a fiber-reinforced plastic product, in which the heating method in the first pressurizing step is preferably a high-frequency induction heating method.

[0051] The present invention proposes a method for producing the fiber-reinforced plastic product, which preferably uses a mold made of a non-magnetic material in the first pressurizing step.

[0052] The present invention proposes a method for producing a fiber-reinforced plastic product, which preferably uses a resin mold in the first pressurizing step.

[0053] The present invention proposes a method for producing a fiber-reinforced plastic product, in which the heating method in the second pressurizing step is preferably a contact heating method.

[0054] The present invention proposes a method for producing a fiber-reinforced plastic product, in which heating in the second pressurizing step is preferably performed by heat transfer.

[0055] The present invention proposes a method for producing the fiber-reinforced plastic product, in which a mold made of a metal material is preferably used in the second pressurizing step.

[0056] The invention proposes a method for producing said fibre-reinforced plastic product, preferably in which said fibres are conductive fibres.

[0057] The invention proposes a method for the manufacture of said fibre-reinforced plastic product, preferably in which said fibres are carbon fibres.

[0058] The present invention proposes a method for manufacturing said fiber reinforced plastic product, preferably wherein the ratio of said fiber to said resin used in said additive manufacturing technology process is 20 / 100≦(volume of said resin) / (volume of said fiber+volume of said resin).

[0059] The present invention proposes a method for manufacturing said fiber reinforced plastic product, preferably in which the ratio of said fiber to said resin used in said additive manufacturing technology process is 25 / 100≦(volume of said resin) / (volume of said fiber+volume of said resin).

[0060] The present invention proposes a method for manufacturing said fiber reinforced plastic product, preferably wherein the ratio of said fiber to said resin used in said additive manufacturing technology process is 30 / 100≦(volume of said resin) / (volume of said fiber+volume of said resin).

[0061] The present invention proposes a method for manufacturing said fiber reinforced plastic product, preferably in which the ratio of said fiber to said resin used in said additive manufacturing technology process is 35 / 100≦(volume of said resin) / (volume of said fiber+volume of said resin).

[0062] The present invention proposes a method for manufacturing said fiber reinforced plastic product, preferably in which the ratio of said fiber to said resin used in said additive manufacturing technology process is (volume of said resin) / (volume of said fiber+volume of said resin)≦55 / 100.

[0063] The present invention proposes a method for manufacturing said fiber reinforced plastic product, preferably in which the ratio of said fiber to said resin used in said additive manufacturing technology process is (volume of said resin) / (volume of said fiber+volume of said resin)≦50 / 100.

[0064] The present invention proposes a method for manufacturing said fiber reinforced plastic product, preferably in which the ratio of said fiber to said resin used in said additive manufacturing technology process is (volume of said resin) / (volume of said fiber+volume of said resin)≦45 / 100.

[0065] The present invention proposes a method for manufacturing said fiber reinforced plastic product, preferably in which the ratio of said fiber to said resin used in said additive manufacturing technology process is (volume of said resin) / (volume of said fiber+volume of said resin)≦40 / 100.

[0066] The present invention proposes a method for producing the fiber-reinforced plastic product, preferably in which the pressurizing mold used in the first pressurizing step and the pressurizing mold used in the second pressurizing step are different.

[0067] The present invention proposes a method for producing a fiber-reinforced plastic product, in which the first pressurizing step and the second pressurizing step are preferably separate steps that are discontinuous in time.

[0068] The present invention proposes a method for manufacturing the fiber-reinforced plastic product, preferably a method in which the product obtained through the first pressurizing step is removed from the pressurizing mold used in the first pressurizing step and placed in a pressurizing mold used in the second pressurizing step and pressurized.

[0069] The present invention proposes a method for manufacturing the fiber-reinforced plastic product, preferably in which a mold having at least a lower mold, a middle mold, and an upper mold is used in the first pressurizing step, the lower mold has a curved surface portion, the upper mold has a curved surface portion, the curved surface portion of the upper mold corresponds to the curved surface portion of the lower mold, and the middle mold has a guide portion that guides the product obtained through the additive manufacturing technology step toward the lower mold, the middle mold is placed relative to the lower mold, the product obtained through the additive manufacturing technology step is placed relative to the guide portion of the middle mold, and the upper mold is placed relative to the product placed relative to the guide portion, and pressure is applied between the lower mold and the upper mold, so that a curved portion corresponding to the curved surface portion is formed in the product existing between the curved surface portion of the lower mold and the curved surface portion of the upper mold.

[0070] The present invention is a method for producing a fiber-reinforced plastic product, and preferably, in the first pressurizing step, a mold having at least a lower mold, a middle mold, and an upper mold is used, the lower mold having a curved surface portion, the upper mold having a curved surface portion, the curved surface portion of the upper mold corresponding to the curved surface portion of the lower mold, the middle mold having a guide portion for guiding a product obtained through the additive manufacturing technology step to the lower mold side, and the middle mold having a flat surface on the upper surface and a curved surface portion on the lower surface corresponding to the curved surface portion of the lower mold. the guide portion is a gap provided in the vertical direction of the middle mold, the gap being connected to the curved surface portion of the lower mold, the middle mold being placed relative to the lower mold, a product obtained through the additive manufacturing technology process being placed relative to the guide portion of the middle mold, the upper mold being placed relative to the product placed relative to the guide portion, and pressure being applied between the lower mold and the upper mold, so that a curved portion corresponding to the curved surface portion is formed in the product existing between the curved surface portion of the lower mold and the curved surface portion of the upper mold.

[0071] The present invention proposes a method for manufacturing a fiber-reinforced plastic product, preferably in which a mold having at least a lower mold and an upper mold is used in the second pressurizing step, the upper mold and the lower mold have a cavity corresponding to the shape of the final product when the upper mold is placed relative to the lower mold, the product obtained through the first pressurizing step is placed on the lower mold, the upper mold is placed on top of the product placed on the lower mold, and pressure is applied between the lower mold and the upper mold.

[0072] The present invention proposes a method for manufacturing a fiber-reinforced plastic product, preferably in which a mold having at least a lower mold and an upper mold is used in the second pressurizing step, the upper mold and the lower mold have a cavity corresponding to the shape of the final product when the upper mold is placed relative to the lower mold, the cavity being composed of a groove formed on the surface of the upper mold and a groove formed on the surface of the lower mold, the groove having an approximately U-shaped cross-sectional shape, the product obtained through the first pressurizing step being placed on the lower mold, the upper mold being placed from above the product placed on the lower mold, and pressure being applied between the lower mold and the upper mold.

[0073] The invention proposes a method for manufacturing said fiber reinforced plastic product, preferably in which the product obtained through said additive manufacturing technology process is in the form of a flat plate.

[0074] The present invention proposes a method for manufacturing the fiber-reinforced plastic product, preferably, the product obtained through the additive manufacturing technology process is flat, and the product obtained through the first pressing process is three-dimensional. Effect of the Invention

[0075] The product obtained through the additive manufacturing technology process is pressurized in two separate processes, the first pressurization process and the second pressurization process. Therefore, even if not all of the fibers are integrally bonded together by the resin in the product obtained through the additive manufacturing technology process, the product is less likely to lose its shape, and a beautiful, three-dimensional fiber-reinforced plastic product is obtained. The mechanical strength was excellent. The present invention is easy to implement. [Brief description of the drawings]

[0076] [Figure 1] A perspective view of product A obtained through the additive manufacturing technology process [Diagram 2] FIG. 1 is an exploded perspective view of a mold used in the first pressing step. [Diagram 3] An exploded side view of the mold used in the first pressing step. [Figure 4] An explanatory diagram showing product A obtained through the additive manufacturing technology process placed in the mold used in the first pressurization process. [Diagram 5] Illustrative diagram of the first pressurizing step [Figure 6] A perspective view of product B obtained through the first pressing step. [Figure 7] A perspective view of product B obtained through the first pressing step. [Figure 8] An explanatory diagram of the state in which product B obtained through the first pressurizing process is placed on the mold (lower mold) used in the second pressurizing process. [Figure 9] A perspective view of the product C obtained through the second pressing process. [Figure 10] A perspective view of the product C obtained through the second pressing process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0077] Embodiments of the present invention are described.

[0078] The present invention relates to a method for producing a fiber-reinforced plastic product. The method is a method for producing a fiber-reinforced plastic product having fibers and resin. For example, the method is a method for producing a fiber-reinforced plastic product having a three-dimensional shape. The fiber is, for example, a conductive fiber. Examples of the conductive fiber include metal fiber and carbon fiber. From the viewpoint of light weight and mechanical properties, carbon fiber is preferable.

[0079] The manufacturing method includes an additive manufacturing process. The additive manufacturing process is a process in which additive manufacturing technology is used. In the additive manufacturing process, for example, an additive manufacturing device equipped with a nozzle is used. In the process, a resin (plastic) and fibers are used. In the process, the resin (resin that becomes the matrix) and the fibers may be supplied (discharged) from separate nozzles. Each material may be supplied (discharged) simultaneously. They may be supplied (discharged) with a time difference. A fiber-reinforced plastic material (a material in which fibers are dispersed in a resin) may be supplied (discharged) from one nozzle. A fiber-reinforced plastic product of a desired shape is obtained by the process. In the additive manufacturing process, for example, additive manufacturing technology using fused deposition modeling may be used. In the additive manufacturing process, for example, an additive manufacturing technique is used that does not include a coating / printing step of coating / printing uncoagulated coagulant on the top surface of the laminate or on the surface of a sheet to be laminated on the laminate based on laminate area data in a predetermined cross section of a three-dimensional model, and a bonding step of overlapping and bonding the sheet coated / printed with the uncoagulated coagulant and the laminate in a warm state, or does not include a bonding step of stacking sheets with a coagulant selectively coated on the surface and selectively bonding the sheets with the coagulant, and an additive manufacturing technique is used in which fibers and resin are used for molding. In the additive manufacturing process, for example, an additive manufacturing technique is used that does not include a step of stacking and bonding sheets coated with a coagulant, and an additive manufacturing technique is used in which fibers and resin are used for molding. The product obtained through the additive manufacturing process was approximately flat. It is not a three-dimensional shape (three-dimensional shape). A flat shape is not considered to be a three-dimensional shape. For example, it is not a three-dimensional shape having a flat surface portion and an intersecting surface portion intersecting the flat surface portion. It was not easy to obtain a product with the three-dimensional shape (solid shape) using additive manufacturing technology alone. It was easy (relatively easy) to obtain a roughly flat product using additive manufacturing technology. In a product obtained through the additive manufacturing technology process, not all of the fibers are integrally (rigidly) bonded by the resin. In the product, the fibers are partially separated. The fibers are only loosely connected to one another.The term "separated" means that the product (the product obtained through the additive manufacturing technology process) is not a fixed shape. For example, the term "separated" means that the fibers will be displaced when a force that bends the product into an approximately arch shape is applied to the product. If all of the fibers are integrally (strongly) bonded by the resin, the fibers will not be displaced even if the force described above is applied to the product. Of course, it is a different story if a force large enough to destroy the product is applied. Even if the force is small enough not to destroy the product, the fibers will easily be displaced when the force described above is applied to the product. "Not integrally bonded" or "partially separated" means the above-mentioned. When the amount of resin was small (the amount of fiber was large), it was difficult for all of the fibers to be integrally bonded by the resin. When the amount of fiber (e.g., carbon fiber) was small, the mechanical strength of the product obtained was poor. When the amount of fiber (e.g., carbon fiber) was large, the mechanical strength of the product obtained was excellent. When the amount of carbon fiber was large, the product obtained was heavy. From this viewpoint, the preferable ratio between the two was as follows. Preferably, 20 / 100≦(volume of the resin) / (volume of the fiber+volume of the resin). More preferably, 25 / 100≦(volume of the resin) / (volume of the fiber+volume of the resin). Even more preferably, 30 / 100≦(volume of the resin) / (volume of the fiber+volume of the resin). Even more preferably, 35 / 100≦(volume of the resin) / (volume of the fiber+volume of the resin). Preferably, (volume of the resin) / (volume of the fiber+volume of the resin)≦55 / 100. More preferably, (volume of the resin) / (volume of the fiber+volume of the resin)≦50 / 100. Even more preferably, (volume of the resin) / (volume of the fiber+volume of the resin)≦45 / 100. More preferably, (volume of the resin) / (volume of the fiber+volume of the resin)≦40 / 100. An object having substantially the same shape as the fiber-reinforced plastic product A may be molded by one (one) additive manufacturing technology process. The product A may be a combination of parts A1, ..., parts Ak (k is an integer equal to or less than n), ..., parts An (n is an integer equal to or greater than 2).In such a case, the part A1 is formed by one (single) additive manufacturing technology process A1. Similarly, the part Ak is formed by one (single) additive manufacturing technology process Ak. The part An is formed by one (single) additive manufacturing technology process An. When the parts A1, ..., Ak, ..., An formed by the additive manufacturing technology processes A1, ..., Ak, ..., An are combined, this combination will have the same shape as the product A. In other words, there are cases where one (single) additive manufacturing technology process is sufficient, and cases where two or more (two or more) processes are required. Which one is adopted is determined by the contents of the product A.

[0080] The manufacturing method includes a first pressurizing step. The first pressurizing step is a step in which the product obtained through the additive manufacturing technology step is pressurized. Through the first pressurizing step, most of the fibers are integrally bonded by the resin. That is, the fibers are integrally bonded to a certain degree firmly by the resin. When the fibers are integrally bonded by the resin, the fibers are unlikely to shift position even if the above-mentioned force is applied to the product. Even if the above-mentioned force is applied to the product that has undergone the first pressurizing step, the product is unlikely to deform. Of course, this is a different matter if a force large enough to destroy the product is applied. In contrast, in the case of a product at a stage obtained through the additive manufacturing technology step, when a large force is applied, the fibers are shifted position or the product is deformed. The product obtained through the first pressurizing step has a curved portion. Therefore, the shape of the product is three-dimensional. In contrast, the product at a stage obtained through the additive manufacturing technology step is flat. Therefore, at this stage, the product does not have a curved portion (a surface that intersects with a plane). In the first pressurizing process, a two-dimensional product is molded into a three-dimensional product. If the force applied in the first pressurizing process is too large, the fibers in the product obtained through the additive manufacturing technology process are not firmly integrated with the resin, and the shape is easily distorted. Therefore, it is preferable not to apply too large a force. In other words, the force applied in the first pressurizing process is smaller than the force applied to form the final product shape. The first pressurizing process is a process in which multiple products obtained through the additive manufacturing technology process are stacked and pressed. Of course, in some cases, there may be only one product. In order to prevent the shape from being distorted during deformation, the number of pressurizations in the first pressurizing process may be multiple (two or more). Of course, it may be one time. The force applied in the first pressurizing process may be increased in stages (gradually). When changing the applied force, it is preferable to apply a small force at first and a large force later. When the force applied in the first pressurizing step is changed from "small" to "large," the "large force" may be equal to the "force applied in the second pressurizing step described below. In such a case, it is not possible to strictly separate the first pressurizing step from the second pressurizing step.In the present invention (this specification), the terms "first pressurizing step" and "second pressurizing step" are used merely for convenience. When the force applied in the "first pressurizing step" changes, the "second pressurizing step" should be considered to be included in the "first pressurizing step". In other words, it can be considered that "the step in which the force in the first pressurizing step is large" = "the second pressurizing step". The "large force" in the step is "a force that causes the fibers in the product to shift position" when the "large force" is applied to the product obtained through the additive manufacturing technology step. When such a force is applied, even if it is formally the first pressurizing step, it is considered to be the second pressurizing step in substance. The change in the force may be continuous (analog) or discontinuous (stepwise: stepwise: digital). In the above, a case where the force applied in the first pressurizing step is changed from "small" to "large" has been described. However, the force applied in the first pressurizing process may be changed from "small" to "even smaller." Even in the case of such a change in force, since the process is in a heated state, the product obtained through the additive manufacturing technology process will be compressed (e.g., thinner) even with an "even smaller" force. When pressurization is performed multiple times (two or more times) in the first pressurizing process, the magnitude of the applied force was different in the above explanation. However, it may be the same. In this case, it can be considered that there is a rest period between the first and second applications in the first pressurizing process.

[0081] The manufacturing method includes a second pressing step. The second pressing step is a step in which the product obtained through the first pressing step is pressed under heating. The force applied in the second pressing step is greater than the force applied in the first pressing step. The force applied in the second pressing step is greater than the force applied at the initial stage of the first pressing step. That is, the force applied in the second pressing step is the force applied to form the final product shape. The volume of the product obtained through the second pressing step is smaller than the volume of the product obtained through the first pressing step. In the first pressing step, deformation occurred from a two-dimensional shape (flat plate shape) to a three-dimensional shape (solid shape). Shape deformation also occurred in the second pressing step. However, the deformation was a deformation of substantially similar shapes. Along with this fact, it was considered that even when a large force was applied, the product did not deform. In the second pressing step, a plurality of products obtained through the first pressing step may be stacked and pressed. In some cases, there may also be a case of one product. In this specification (including the claims), "the volume of the product obtained through the second pressing step is smaller than the volume of the product obtained through the first pressing step" must be interpreted as follows. Assuming that the volume of the product obtained through the first pressing step is A1 and the volume of the product obtained through the second pressing step is A2, then A2 < A1. A2 < A1 is natural when (the object processed in the second pressing step) and (the object processed in the first pressing step) are the same. However, when X (the object processed in the second pressing step) is {Y (the object processed in the first pressing step) + Z (the object not processed in the first pressing step)}, there may be a case where A2 > A1. However, even in such a case, when considering only the product obtained through the first pressing step, that is, when excluding Z (the object not processed in the first pressing step), A2 < A1. When a plurality of products obtained through the first pressing step are stacked and the second pressing step is performed, it should be interpreted as follows. If the volume of one product obtained through the first pressing step is A1 and the volume when n of these are stacked is n × A1, and the volume when the product with volume (n × A1) is processed in the second pressing step is A2, then A2 < n × A1.

[0082] The pressure in the first pressurizing step is lower than the pressure in the second pressurizing step. For example, (pressure in the first pressurizing step) / (pressure in the second pressurizing step) was 0.8 or less. For example, 0.7 or less. For example, 0.6 or less. For example, 0.5 or less. For example, 0.4 or less. For example, 0.02 or more. For example, 0.05 or more. For example, 0.1 or more. The pressure in the first pressurizing step was 0.8 kPa or more. For example, 4 kPa or more. For example, 8.0×10 5 kPa or less. For example, 4.0×10 5 The pressure in the second pressurizing step was 1 kPa or more. For example, 5 kPa or more. For example, 1.0×10 6 kPa or less. For example, 5.0×10 5 kPa or less. (Volume of the product obtained through the first pressurizing step) / (Volume of the product obtained through the second pressurizing step)≦2.5. For example, 2 or less. For example, 1.5 or less. For example, 1.05 or more. For example, 1.1 or more.

[0083] In the additive manufacturing technology process, when the resin is a thermoplastic resin, from the viewpoint of moldability, the temperature is preferably 30°C or higher. More preferably, it is 50°C or higher. Even more preferably, it is 100°C or higher. There is no particular restriction on the upper limit value. However, in general, it is preferably 700°C or lower. More preferably, it is 500°C or lower. Even more preferably, it is 450°C or lower. Even more preferably, it is 400°C or lower. When the resin is a thermosetting resin, from the viewpoint of moldability, the temperature is preferably 0°C or higher. Even more preferably, it is 10°C or higher. Even more preferably, it is 20°C or higher. Even more preferably, it is 30°C or higher. It is preferably 350°C or lower. Even more preferably, it is 150°C or lower. Even more preferably, it is 100°C or lower.

[0084] The first pressurizing step is preferably carried out under heated conditions. The reason is that by raising the temperature higher than room temperature (room temperature: for example, 25°C), the resin (resin composition) becomes soft. As a result, the moldability by pressurization is improved. The heating temperature should satisfy the following conditions. For example, the temperature was equal to or higher than the melting temperature in the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation) in accordance with the manual attached to the device. Preferably, the temperature was {the melting temperature + 10°C} or higher. More preferably, the temperature was {the melting temperature + 20°C} or higher. Preferably, the temperature was {the melting temperature + 60°C} or lower. More preferably, the temperature was {the melting temperature + 50°C} or lower. More preferably, the temperature was {the melting temperature + 40°C} or lower. Even more preferably, the temperature was {the melting temperature + 30°C} or lower. When the resin is a thermoplastic resin, the temperature may be, for example, higher than the melting temperature. When the resin is a thermosetting resin, the temperature may be, for example, less than the curing temperature. The melting temperature is also called the softening point (softening temperature). The temperature was obtained by the following method. A constant load extrusion type capillary rheometer (flow characteristic evaluation device: Flow Tester CFT-500D (manufactured by Shimadzu Corporation)) was used, and the measurement was performed according to the manual attached to the device. In this device, a constant load is applied from the top of the measurement sample (the sample in this case is not a resin containing fiber, but a resin not containing fiber) by a piston. The measurement sample filled in the cylinder is heated and melted. The molten measurement sample is extruded from the die at the bottom of the cylinder. A flow curve showing the relationship between the piston descent amount and the temperature is obtained. The melting temperature in the 1 / 2 method described in the manual was calculated as follows. 1 / 2 of the difference between the piston descent amount Smax at the time when the outflow ends and the piston descent amount Smin at the time when the outflow starts is calculated (this is X. X=(Smax-Smin) / 2). The temperature on the flow curve at the time when the piston descent amount becomes X on the flow curve is the melting temperature in the 1 / 2 method. For example, when the resin was PA6 (thermoplastic resin), the melting temperature (softening temperature) obtained by the above method was about 225°C. When the resin was polycarbonate resin (thermoplastic resin), the melting temperature (softening temperature) obtained by the above method was about 250°C. When the resin was thermoplastic polyimide (thermoplastic resin), the melting temperature (softening temperature) obtained by the above method was about 388°C. When the resin was epoxy resin (thermosetting resin), the melting temperature (softening temperature) obtained by the above method was about 70°C. When the resin was benzoxazine (thermosetting resin), the melting temperature (softening temperature) obtained by the above method was about 80°C. When the resin was cyanate resin (thermosetting resin), the melting temperature (softening temperature) obtained by the above method was about 80°C.

[0085] The second pressurizing step is preferably carried out under heated conditions. The reason is that by raising the temperature higher than room temperature (room temperature: for example, 25°C), the resin (resin composition) becomes soft. As a result, the moldability by pressurization is improved. The heating temperature in the second pressurizing step should satisfy the following conditions. The heating temperature may be any temperature at which the resin is softer than at room temperature (25° C.). For example, the heating temperature is preferably equal to or higher than the melting temperature (softening temperature). When the resin is a thermoplastic resin, the heating temperature is more preferably a temperature of {the melting temperature (softening temperature) + 10°C} or more. Even more preferably a temperature of {the melting temperature (softening temperature) + 20°C} or more. Even more preferably a temperature of {the melting temperature (softening temperature) + 30°C} or more. Preferably, the heating temperature is a temperature of {the melting temperature (softening temperature) + 100°C} or less. Even more preferably, the heating temperature is a temperature of {the melting temperature (softening temperature) + 90°C} or less. Even more preferably, the heating temperature is a temperature of {the melting temperature (softening temperature) + 80°C} or less. Even more preferably, the heating temperature is a temperature of {the melting temperature (softening temperature) + 70°C} or less. When the resin is a thermosetting resin, the heating temperature is preferably a temperature of (resin curing temperature -70°C) or more. More preferably, it is a temperature of (resin curing temperature -60°C) or more. Even more preferably, it is a temperature of (resin curing temperature -50°C) or more. Even more preferably, it is a temperature of (resin curing temperature -40°C) or more. Preferably, it is a temperature of (resin curing temperature +20°C) or less. Even more preferably, it is a temperature of (resin curing temperature +10°C) or less. And even more preferably, it is a temperature of (resin curing temperature or less). The curing temperature is the peak temperature in the DSC curve. The heat curing temperature of epoxy resin (thermosetting resin) is about 120 to 180°C. The heat curing temperature of benzoxazine resin (thermosetting resin) is about 120 to 200°C. The heat curing temperature of cyanate resin (thermosetting resin) is about 150 to 250°C. If the resin is a thermosetting resin, an after-cure may be performed.

[0086] The heating method in the first pressurizing step was a non-contact heating method. The heating method was an induction heating method. The heating method was a high-frequency induction heating method. In the first pressurizing step, for example, a mold made of a non-magnetic material was used. For example, a mold made of resin was used. A non-magnetic material such as glass beads or glass fiber may be used in part. A metal material may be used in part.

[0087] The heating method in the second pressurizing step was a contact heating method. For example, heating was performed by heat transfer. A metal mold was used in the second pressurizing step. A non-metallic material may be used in part. The applied pressure in the second pressurizing step is greater than that in the first pressurizing step. Therefore, it was preferable to use a metal mold in the second pressurizing step. The reason is as follows. The pressure in the second pressurizing step is greater than that in the first pressurizing step. This is because metal materials have better pressure resistance than resin materials. The second pressurizing step may be a molding method that generates resin burrs. The pressurizing method in the second pressurizing step is not particularly limited. Examples include press molding, injection molding, transfer molding, and autoclave molding. The second pressurizing step may be integrally molding the product obtained in the first pressurizing step and a second material (a product or material that has not been subjected to the first pressurizing step). The second material is not particularly limited. Examples include injection molding materials, prepreg materials, sheet materials, film materials, and resin materials. It does not have to contain reinforcing fibers.

[0088] The pressurizing mold used in the first pressurizing step was different from the pressurizing mold used in the second pressurizing step.

[0089] The product obtained through the first pressurizing step was taken out of the pressurizing mold used in the first pressurizing step, and placed in a pressurizing mold used in the second pressurizing step and pressed there.

[0090] In the first pressurizing step, for example, a mold including a lower mold, a middle mold, and an upper mold was used. The lower mold has a curved surface portion. The upper mold has a curved surface portion. The curved surface portion of the upper mold corresponds to the curved surface portion of the lower mold. The middle mold has a guide portion that guides the product obtained through the additive manufacturing technology step toward the lower mold. The middle mold was placed relative to the lower mold. The product obtained through the additive manufacturing technology step was placed relative to the guide portion of the middle mold. The upper mold was placed relative to the product placed relative to the guide portion. Pressure was applied between the lower mold and the upper mold, and a curved portion corresponding to the curved surface portion was formed in the product existing between the curved surface portion of the lower mold and the curved surface portion of the upper mold.

[0091] The middle mold has, for example, a flat surface on the upper surface and a curved surface portion on the lower surface corresponding to the curved surface portion of the lower mold. The guide portion is a gap portion provided in the vertical direction of the middle mold. The gap portion is connected to the curved surface portion of the lower mold. The middle mold is placed on the lower mold, a product obtained through the additive manufacturing technology process is placed on the guide portion of the middle mold, and the upper mold is placed on the product placed on the guide portion, and pressure is applied between the lower mold and the upper mold, forming a curved portion corresponding to the curved surface portion in the product present between the curved surface portion of the lower mold and the curved surface portion of the upper mold.

[0092] In the second pressurizing step, for example, a mold having a lower mold and an upper mold is used. The upper mold and the lower mold have a cavity corresponding to the final product shape when the upper mold is placed relative to the lower mold. The cavity is composed of a groove formed on the lower surface of the upper mold and a groove formed on the upper surface of the lower mold. Therefore, when the product obtained through the first pressurizing step is placed on the groove of the lower mold, a part of the product protrudes from the surface of the lower mold. The groove surface has no corners. The product obtained through the first pressurizing step is placed on the groove of the lower mold, the upper mold is placed on top of the product placed on the lower mold, and pressure is applied between the lower mold and the upper mold. The product obtained in this way has no corners because the groove surface has no corners. If the cavity is composed only of a groove formed on the upper surface of the lower mold, the product obtained in this way will have corners even if the groove has no corners.

[0093] The resin (plastic) used in the present invention may be any resin (matrix resin) that can be used in additive manufacturing technology. A thermoplastic resin is used. A thermosetting resin is used. Only one of them may be used. They may be used in combination. The resin may be one type or two or more types. The resin may be in the form of a film (or sheet). The resin may be in the form of a fiber (yarn or filament). When the resin is in the form of a fiber, in the present invention, it is a so-called mixed fiber yarn (see, for example, WO2016 / 167136A1). In the case of the mixed fiber yarn, the technology disclosed in WO2016 / 167136A1 can be adopted. The resin preferably has a functional group (reactive group: polar group). It is also possible to use a resin that does not have a functional group (reactive group: polar group).

[0094] Thermoplastic resins may consist of only thermoplastic resins or may contain thermoplastic resins as the main component. Either case is acceptable in the present invention. In the present invention (this specification), the term "thermoplastic resin" includes both cases consisting of only thermoplastic resins and cases containing thermoplastic resins as the main component, unless otherwise specified. A thermoplastic resin as the main component means that the thermoplastic resin is 50% by mass or more. Preferably, it is 80% by mass or more. More preferably, it is 90% by mass or more.

[0095] Thermosetting resins may consist of only thermosetting resins or may contain thermosetting resins as the main component. Either case is acceptable in the present invention. In the present invention (this specification), the term "thermosetting resin" includes both cases consisting of only thermosetting resins and cases containing thermosetting resins as the main component, unless otherwise specified. A thermosetting resin as the main component means that the thermosetting resin is 50% by mass or more. Preferably, it is 80% by mass or more. More preferably, it is 90% by mass or more.

[0096] Examples of the thermosetting resin include epoxy resin, vinyl ester resin, unsaturated polyester resin, diallyl phthalate resin, phenol resin, maleimide resin, cyanate resin, benzoxazine resin, and dicyclopentadiene resin.

[0097] Examples of thermoplastic resins include polyolefin resins, polystyrene resins, thermoplastic polyamide resins, polyester resins, polyacetal resins (polyoxymethylene resins), polycarbonate resins, (meth)acrylic resins, polyarylate resins, polyphenylene ether resins, polyimide resins, polyethernitrile resins, phenoxy resins, polyphenylene sulfide resins, polysulfone resins, polyketone resins, polyether ketone resins, thermoplastic urethane resins, fluorine-based resins, and thermoplastic polybenzimidazole resins.

[0098] Examples of the polyolefin resin include polyethylene resin, polypropylene resin, polybutadiene resin, polymethylpentene resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, and polyvinyl alcohol resin.

[0099] Examples of the polystyrene resin include polystyrene resin, acrylonitrile-styrene resin (AS resin), and acrylonitrile-butadiene-styrene resin (ABS resin).

[0100] Examples of the polyamide resin include polyamide 6 resin (nylon 6), polyamide 11 resin (nylon 11), polyamide 12 resin (nylon 12), polyamide 46 resin (nylon 46), polyamide 66 resin (nylon 66), and polyamide 610 resin (nylon 610). Nylon (hereinafter sometimes abbreviated as "PA"), which is one of the polyamide resins, includes PA6 (also called polycaproamide, polycaprolactam, poly-ε-caprolactam), PA26 (polyethylene adipamide), PA46 (polytetramethylene adipamide), PA66 (polyhexamethylene adipamide), PA69 (polyhexamethylene azepamide), PA610 (polyhexamethylene sebacamide), PA611 (polyhexamethylene undecamide), PA612 (polyhexamethylene dodecamide), PA11 (polyundecane amide), PA12 (polydodecanamide), PA1212 (polydodecamethylene dodecamide), PA6T (polyhexamethylene terephthalamide), P Examples include A6I (polyhexamethylene isophthalamide), PA912 (polynonamethylene dodecamide), PA1012 (polydecamethylene dodecamide), PA9T (polynonamethylene terephthalamide), PA9I (polynonamethylene isophthalamide), PA10T (polydecamethylene terephthalamide), PA10I (polydecamethylene isophthalamide), PA11T (polyundecamethylene terephthalamide), PA11I (polyundecamethylene isophthalamide), PA12T (polydodecamethylene terephthalamide), PA12I (polydodecamethylene isophthalamide), polyamide XD6 (polymetaxylylene adipamide), polyamide XD10 (polyxylylene sebacamide), and the like.

[0101] Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polytrimethylene terephthalate resin, and liquid crystal polyester.

[0102] An example of the (meth)acrylic resin is polymethyl methacrylate.

[0103] The modified polyphenylene ether resin is, for example, modified polyphenylene ether.

[0104] Examples of the thermoplastic polyimide resin include thermoplastic polyimide, polyamide-imide resin, and polyether-imide resin.

[0105] Examples of the polysulfone resin include modified polysulfone resin and polyethersulfone resin.

[0106] Examples of the polyether ketone resin include polyether ketone resin, polyether ether ketone resin, and polyether ketone ketone resin.

[0107] The fluorine-based resin is, for example, polytetrafluoroethylene.

[0108] Examples of fibers in the fiber reinforced resin include inorganic fibers. They may be organic fibers. They may be used in combination. The fiber length of the fibers is particularly preferably continuous reinforcing fibers having a fiber length of more than 30 mm. The average fiber length of the continuous reinforcing fibers used in the present invention is not particularly limited, but from the viewpoint of improving molding processability, it is preferable that it is in the range of 0.05 to 20,000 m. More preferably, it is 100 to 10,000 m. Even more preferably, it is 1,000 to 7,000 m. A fiber length of more than 30 mm and a fiber length of 30 mm or less may be used in combination. The length of the fibers in the present invention is the weight average fiber length unless otherwise specified. The average fiber diameter of the fibers is preferably 3 μm or more. More preferably, it is 4 μm or more. Even more preferably, it is 5 μm or more. It is preferably 50 μm or less. It is more preferably 20 μm or less. Even more preferably, it is 12 μm or less. The average fiber diameter is the diameter of a single yarn.

[0109] Examples of the inorganic fibers include, but are not limited to, carbon fibers, silicon carbide fibers, alumina fibers, boron fibers, glass fibers, and metal fibers.

[0110] Examples of the carbon fiber include polyacrylonitrile (PAN)-based carbon fiber, petroleum / coal pitch-based carbon fiber, rayon-based carbon fiber, cellulose-based carbon fiber, lignin-based carbon fiber, phenol-based carbon fiber, and vapor-grown carbon fiber. One or more of these may be used as appropriate. The carbon fiber used preferably has a tensile modulus of 100 GPa to 1000 GPa. The form of the carbon fiber is not particularly limited. The form of the carbon fiber may be continuous or discontinuous. An example of the continuous fiber is one in which carbon fibers are arranged in one direction (unidirectional material). Examples of discontinuous fibers include a material in which carbon fibers are arranged in a resin so as to be oriented in a specific direction, and a material in which carbon fibers are arranged randomly in the in-plane direction. The carbon fiber may be in the form of a single thread, a fiber bundle, or a mixture of both. Carbon fibers are generally in the form of a fiber bundle in which several thousand to several tens of thousands of filaments are assembled. When carbon fiber bundles are used as the carbon fibers, if the carbon fiber bundles are used as they are, the entangled portions of the fiber bundles may become locally thick, making it difficult to obtain a carbon fiber reinforced resin product having a thin end face. Therefore, when carbon fiber bundles are used as the carbon fibers, it is preferable to widen or open the carbon fiber bundles before use.

[0111] Examples of the metal fibers include Al fibers, Au fibers, Ag fibers, Fe fibers, and stainless steel fibers.

[0112] Examples of organic fibers include aramid fibers, aromatic polyamide fibers, cellulose fibers, polyethylene fibers, and poly(paraphenylene benzobisoxazole) fibers (Zylon (manufactured by Toyobo Co., Ltd.)).

[0113] The fibers may be treated with a treatment agent. Examples of the treatment agent include a bundling agent. Examples of the treatment agent include a surface treatment agent. For example, the treatment agent disclosed in Japanese Patent No. 4894982 may be used. It is advantageous if the treatment agent on the fiber surface reacts with the functional group (reactive group: polar group) of the resin.

[0114] The treating agent is selected from the group consisting of epoxy resins, urethane resins, silane coupling agents, water-insoluble polyamide resins, and water-soluble polyamide resins. Preferably, the treating agent is selected from the group consisting of epoxy resins, urethane resins, water-insoluble polyamide resins, and water-soluble polyamide resins. One or more kinds may be used.

[0115] Examples of the epoxy resin include glycidyl compounds (e.g., epoxyalkane, alkane diepoxide, bisphenol A glycidyl ether, dimer of bisphenol A glycidyl ether, trimer of bisphenol A glycidyl ether, oligomer of bisphenol A glycidyl ether, polymer of bisphenol A glycidyl ether, bisphenol F glycidyl ether, dimer of bisphenol F glycidyl ether, trimer of bisphenol F glycidyl ether, oligomer of bisphenol F glycidyl ether, polymer of bisphenol F glycidyl ether, stearyl glycidyl ether, phenyl glycidyl ether, ethylene oxide lauric alcohol glycidyl ether, ethylene glycol di ... diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, etc.), glycidyl ester compounds (e.g., benzoic acid glycidyl ester, p-toluic acid glycidyl ester, stearic acid glycidyl ester, lauric acid glycidyl ester, palmitic acid glycidyl ester, oleic acid glycidyl ester, linoleic acid glycidyl ester, linolenic acid glycidyl ester, phthalic acid diglycidyl ester, etc.), glycidyl amine compounds (e.g., tetraglycidylaminodiphenylmethane, triglycidylaminophenol, diglycidyl aniline, diglycidyl toluidine, tetraglycidyl metaxylenediamine, triglycidyl cyanurate, triglycidyl isocyanurate, etc.).

[0116] Examples of the urethane resin include polyols, polyols obtained by umesterifying fats and oils with polyhydric alcohols, and urethane resins obtained by reacting polyisocyanate with a compound having an OH group.

[0117] Examples of the polyisocyanate include aliphatic isocyanates (e.g., 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,8-diisocyanate methyl caproate, etc.), alicyclic diisocyanates (e.g., 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, methylcyclohexyl-2,4-diisocyanate, etc.), Examples of the polyisocyanate include aromatic diisocyanates (e.g., toluylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthene diisocyanate, diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4-dibenzyl diisocyanate, 1,3-phenylene diisocyanate, etc.), and halogenated diisocyanates (e.g., chlorinated diisocyanates, brominated diisocyanates). The polyisocyanate may be one type or two or more types.

[0118] The polyol may be any of those generally used in the manufacture of urethane resins. For example, diethylene glycol, butanediol, hexanediol, neopentyl glycol, bisphenol A, cyclohexanedimethanol, trimethylolpropane, glycerin, pentaerythritol, polyethylene glycol, polypropylene glycol, polyester polyol, polycaprolactone, polytetramethylene ether glycol, polythioether polyol, polyacetal polyol, polybutadiene polyol, and furandimethanol may be used. The polyol may be one or more.

[0119] Examples of the silane coupling agent include trialkoxy or triallyloxy silane compounds (e.g., aminopropyltriethoxysilane, phenylaminopropyltrimethoxysilane, glycidylpropyltriethoxysilane, methacryloxypropyltrimethoxysilane, vinyltriethoxysilane, etc.), ureidosilane, sulfidosilane, vinylsilane, imidazole silane, etc. The silane coupling agent may be one type or two or more types.

[0120] The present invention will be described in detail below. The following examples are merely examples of the present invention. The present invention is not limited to the following examples. In other words, the present invention also includes modifications and applications that do not significantly impair the features of the present invention.

[0121] [Example 1] A thermosetting resin (benzoxazine resin: manufactured by Aica Kogyo Co., Ltd.) was used. Carbon fiber (manufactured by Mitsubishi Rayon Co., Ltd., Pyrofil-TR-50S-12000-AD, 8000 dtex, fiber count 12000 f.) was used. The blending ratio was 40 parts by volume of the resin and 60 parts by volume of the carbon fiber.

[0122] A 3D printer (Velleman K8200) was used. Additive manufacturing technology was performed (nozzle temperature: 135°C, stage temperature: 50°C). This resulted in product A made of the composition. Product A obtained through the additive manufacturing technology process is as shown in Figures 1 and 2. Product A is approximately flat. It is not a three-dimensional shape (solid shape). Since the amount of resin in product A is relatively small, not all of the fibers are strongly and integrally bonded by the resin.

[0123] A product A obtained through the additive manufacturing technology process shown in Figure 1 was placed in the mold shown in Figures 2 to 5. The mold shown in Figures 2 to 5 is the mold used in the first pressing step.

[0124] In Figs. 2, 3, 4, and 5, 1 is a lower mold. 2 is a middle mold. 3 is an upper mold. The mold used in the first pressurizing step is composed of a lower mold 1, a middle mold 2, and an upper mold 3. The lower mold 1, the middle mold 2, and the upper mold 3 are all made of a non-magnetic material (non-metallic material), for example, resin. The lower mold 1 has a cylindrical portion 4 for guiding. The cylindrical portion 4 is provided according to the shape of the target product. The lower mold 1 has a convex portion or a concave portion (not shown) for positioning the middle mold 2 as needed. The upper surface portion of the lower mold 1 has a curved surface portion 5. The middle mold 2 has a concave portion or a convex portion (not shown) that fits the convex portion or concave portion as needed. The lower surface portion of the middle mold 2 has a curved surface portion 6 that comes into surface contact with the curved surface portion 5 when the middle mold 2 is placed against the lower mold 1. The middle mold 2 has a gap 7 into which the cylindrical portion 4 fits when the middle mold 2 is placed against the lower mold 1. The gap 7 is also present above the curved surface portions 5 and 6. The gap 7 may be connected to the end surface of the middle mold 2. When the middle mold 2 is placed against the lower mold 1, the lower surface of the middle mold 2 comes into surface contact with the upper surface of the lower mold 1. The upper surface of the middle mold 2 is a flat surface. The upper mold 3 has a structure that allows the upper mold 3 to be placed against the middle mold 2 when the product A obtained through the additive manufacturing technology process is placed at a predetermined position on the middle mold 2 placed against the lower mold 1. The upper mold 3 has a vertical wall 8. The vertical wall 8 has a recess 9 into which the cylindrical portion 4 can fit. The cross-sectional outer shape of the vertical wall 8 in the horizontal plane is approximately the same shape as the cross-sectional inner shape of the gap 7 in the horizontal plane. When the upper mold 3 is placed against the middle mold 2, the vertical wall 8 fits into the gap 7. When the upper die 3 is placed relative to the middle die 2, the lower end surface of the vertical wall 8 has a curved surface portion 10 that comes into surface contact with the curved surface portion 6. The lower die 1, the middle die 2, and the upper die 3 are configured so that when the lower die 1, the middle die 2, and the upper die 3 are combined, the space (cavity) that exists inside corresponds to the shape of the target product B (in this example, the product in Figures 6 and 7).

[0125] The middle mold 2 was placed against the lower mold 1. The product A (3 sheets) obtained through the additive manufacturing technology process was placed against the position of the void 7 of the middle mold 1. The upper mold 3 was placed against the product A placed against the position of the void 7. The vertical wall 8 of the upper mold 3 was pressed into the void 7 of the middle mold 1 (see Figures 4 and 5). The pressure was 1500 kPa. The middle mold 2 is called a guide mold. The middle mold 2 functions as a guide to regulate the position of the product A shown in Figure 1 (i.e., the product obtained through the additive manufacturing technology process in the first pressurizing process). When the vertical wall 8 of the upper mold 3 is pressed into the void 7 of the middle mold 1, it serves to regulate the position of the product A. A high-frequency induction heating device was used. The product A having carbon fiber obtained through the additive manufacturing technology process was heated to 80 to 100 ° C. Since the lower mold 1, the middle mold 2, and the upper mold 3 are made of resin, heat is not generated. That is, the mold is not hot even when touched with bare hands. A curved portion was formed in the flat product A sandwiched between the curved surface portion 5 and the curved surface portion 10 (see FIG. 5). The pressing force compressed the product A obtained through the additive manufacturing technology process. The pressure was maintained for 5 to 10 seconds until the product A cooled. As a result, unlike the product A obtained through the additive manufacturing technology process, most of the fibers were integrally bonded by the resin (see FIGS. 6 and 7). That is, even when a small force was applied, the product B shown in FIGS. 6 and 7 did not lose its shape.

[0126] FIG. 8 is an explanatory diagram of a mold used in the second pressurizing step. Reference numeral 21 denotes a lower mold made of metal. Lower mold 21 has a curved surface portion. A groove 22 having a shape that conforms to the shape of the lower half of the product obtained through the second pressurizing step described below is formed on the surface of lower mold 21. The cross-sectional shape of groove 22 is approximately U-shaped. In other words, there are no corners on the surface of groove 22. The mold used in the second pressurizing step has an upper mold made of metal similar to lower mold 21. In other words, the lower mold 21 and the upper mold form a molding mold. The upper mold also has a curved surface portion similar to the curved surface portion. A groove similar to groove 22 is formed on the surface of the upper mold. The cross-sectional shape of the groove is also approximately U-shaped.

[0127] The product B shown in Figures 6 and 7 (the product obtained through the first pressurizing step) was placed on the groove 22 of the lower die 21 shown in Figure 8 (see Figure 8). Then, the corresponding upper die was placed, and heating (180°C) and pressurization (60,000 kPa) were performed. The desired final product C (see Figures 9 and 10) was obtained.

[0128] [Comparative Example 1] The same procedure was carried out as in Example 1, except that the first pressurization step was omitted. That is, the products (3 sheets) obtained through the additive manufacturing technology steps shown in Fig. 1 were placed in the grooves of the mold shown in Fig. 8, and heated (180°C) and pressurized (60,000 kPa). The product thus obtained had a collapsed shape. The final product C as obtained in Example 1 was not obtained.

[0129] This shows the importance of the first pressurization step. That is, in the product obtained through the additive manufacturing technology process, the carbon fibers were not integrally bonded by the resin, and the carbon fibers were partially separated. Even when the product obtained through the additive manufacturing technology process was placed on the groove 22 of the lower mold 21 shown in Figure 8, a part of the product did not fit within the groove 22. When a large force was applied, the carbon fibers in the product were displaced, and the desired product was not obtained.

[0130] [Comparative Example 2] In Example 1, the ratio of resin:carbon fiber was 60 parts by volume:40 parts by volume. That is, the same procedure as in Example 1 was carried out except that the ratio of resin was increased. The final product obtained in Comparative Example 2 did not lose its shape, similar to Example 1. By increasing the ratio of resin so that the carbon fibers in the product obtained through the additive manufacturing technology process are integrally bonded by the resin, the final product does not lose its shape, unlike the case of Comparative Example 1. However, the product of Comparative Example 2 was inferior to the product of Example 1 in mechanical strength.

[0131] [Comparative Example 3] In Comparative Example 1, the ratio of resin:carbon fiber was 60 parts by volume:40 parts by volume. That is, the same procedure as in Comparative Example 1 was carried out except that the amount of resin was increased. The final product obtained in Comparative Example 3 did not lose its shape, similar to Example 1 and Comparative Example 2. By increasing the ratio of resin so that the carbon fibers in the product obtained through the additive manufacturing technology process are integrally bonded by the resin, the final product would not lose its shape as in Comparative Example 1, even if the first pressurization step was omitted. However, the product of Comparative Example 3 was inferior to the product of Example 1 in mechanical strength.

[0132] [Comparative Example 4] The same procedure was carried out as in Example 1, except that the second pressurizing step was omitted. The product obtained in Comparative Example 4 is shown in Figures 6 and 7. The product had a poor appearance. It also had poor mechanical strength. It was believed that the reason for the poor mechanical strength was as follows: If sufficient pressure was not applied, voids (air bubbles) would form inside the product. It was believed that the generation of the voids was caused by the fibers. It was believed that the presence of the voids reduced the improvement in the mechanical strength of the product. It was believed that if sufficient pressure (particularly heating and pressure) was applied in the second pressure step, the voids would have decreased (or disappeared), and the mechanical strength would have been improved. It might seem that applying sufficient pressure in the first pressure step would be sufficient, but because the resin had not hardened, when it was heated to a temperature above the melting point of the resin using the 1 / 2 method with a flow tester CFT-500D (manufactured by Shimadzu Corporation), the shape collapsed.

[0133] [Comparative Example 5] The same procedure was carried out as in Example 1, except that no carbon fiber was used. The product obtained in Comparative Example 5 had poor mechanical strength.

[0134] [Example 2] Thermoplastic resin (Lexter8500: manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used. Carbon fiber (Pyrofil-TR-50S-12000-AD, 8000 dtex, fiber count 12000f: manufactured by Mitsubishi Rayon Co., Ltd.) was used. The blending ratio was 50 parts by volume of the resin and 50 parts by volume of the carbon fiber. The 3D printer used in Example 2 was K8200 manufactured by Velleman (nozzle temperature: 220°C, stage temperature: 50°C). The temperature in the first pressurizing step was 210 to 270°C, and the pressure was 1500 kPa. The temperature in the second pressurizing step was 230°C, and the pressure was 60000 kPa. The rest was performed in accordance with Example 1. The product thus obtained was as excellent as that of Example 1.

[0135] [Comparative Example 6] The same procedure was carried out as in Example 2, except that the first pressurization step was omitted. The results were similar to those in Comparative Example 1. [Comparative Example 7] In Example 2, the ratio of resin:carbon fiber was 60 parts by volume:40 parts by volume. The results were similar to those of Comparative Example 2, that is, the mechanical strength was poor.

[0136] [Comparative Example 8] In Comparative Example 6, the ratio of resin:carbon fiber was 60 parts by volume:40 parts by volume. That is, the same procedure as in Comparative Example 6 was carried out except that the amount of resin was increased. The final product obtained in Comparative Example 8 did not lose its shape. However, the product of Comparative Example 8 was inferior to the product of Example 2 in mechanical strength.

[0137] [Comparative Example 9] The same procedure was followed as in Example 2, except that the second pressurization step was omitted. The product obtained in Comparative Example 9 is shown in Figures 6 and 7. The product had poor appearance. It also had poor mechanical strength. Although it would have been fine if sufficient pressure had been applied in the first pressure application step, in this case the problem of deformation occurred.

[0138] [Comparative Example 10] Example 2 was carried out in the same manner, except that no carbon fibers were used. The product obtained in Comparative Example 10 had poor mechanical strength.

[0139] [Example 3] PEEK (manufactured by Victrex, Victrex (registered trademark): thermoplastic resin) was used. The Pyrofil-TR-50S-12000-AD was used. The blending ratio was 30 parts by volume of the resin and 70 parts by volume of the carbon fiber. The same procedure as in Example 1 was carried out.

[0140] [Example 4] A sheet of Torayca prepreg P3252S-25 (thermosetting resin: epoxy resin manufactured by Toray Industries, Inc.) and carbon fiber (T700SC) with the resin:carbon fiber = 40 volume parts:60 volume parts was slit (width: 0.8 mm). It was processed into a circular cross section with a diameter of 0.5 mm. This processed object (material) was used and carried out in the same manner as in Example 1. The 3D printer used in this Example 4 was Velleman K8200 (nozzle temperature: 60 ° C, stage temperature: 10 ° C). The temperature in the first pressurization step was 80 ° C, and the pressure was 500 kPa. The temperature in the second pressurization step was 130 ° C, and the pressure was 2000 kPa. The product thus obtained was excellent, as in Example 1. It did not lose its shape and had excellent mechanical strength. [Explanation of symbols]

[0141] 1 Lower mold 2 medium size 3 Upper mold 4 Cylinder section 5,6,10 Curved surface 7 Cavity 8 vertical walls 9 Recess 21 Lower mold 22 Groove A. Products obtained through additive manufacturing processes B. Product obtained through the first pressurization process C. The product obtained through the second pressurization process

Claims

1. A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method comprises an additive manufacturing step, a first pressurizing step, and a second pressurizing step; The first pressurizing step includes a process in which a deformation due to pressure occurs on a flat surface of the product obtained in the additive manufacturing technology step, and a surface intersecting the flat surface is formed; The second pressurizing step is a step in which the product obtained through the first pressurizing step is pressurized under heat, and a product having a volume smaller than that of the product obtained by the first pressurizing step is obtained. A method for manufacturing fiber-reinforced plastic products.

2. The additive manufacturing process results in a product in which not all of the fibers are integrally bound by the resin, but rather the fibers are partially separated. A method for producing the fiber reinforced plastic product of claim 1.

3. The first pressing step is a step in which the product obtained by the additive manufacturing technology step is pressed to obtain a product in which most of the fibers are integrally bonded by the resin. A method for producing the fiber reinforced plastic product of claim 1.

4. A method for producing a fiber-reinforced plastic product having fibers and a resin, comprising: The method includes an additive manufacturing step, a first pressing step, and a second pressing step. the additive manufacturing process is a process for obtaining a product in which not all of the fibers are integrally bound by the resin and the fibers are partially separated, The first pressurizing step includes a process in which the product obtained in the additive manufacturing technology step is placed in a mold made of a non-magnetic material and pressurized, and non-contact heating is performed during pressurization in the first pressurizing step. A method for manufacturing fiber-reinforced plastic products.

5. The first pressurizing step is a step in which a plurality of products obtained through the additive manufacturing technology step are stacked and pressed. A method for producing a fiber-reinforced plastic product according to any one of claims 1, 3 and 4.

6. The pressure in the first pressurizing step is lower than the pressure in the second pressurizing step. A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

7. (Volume of the product obtained through the first pressurizing step) / (Volume of the product obtained through the second pressurizing step)≦2.5 A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

8. The first pressurizing step is a step of pressurizing at a temperature equal to or higher than the melting temperature of the resin by the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation). A method for producing a fiber-reinforced plastic product according to any one of claims 1, 3 and 4.

9. The second pressurizing step is a step of pressurizing at a temperature equal to or higher than the melting temperature of the resin by the 1 / 2 method using a flow tester CFT-500D (manufactured by Shimadzu Corporation). A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

10. The heating method in the first pressurizing step is a non-contact heating method. A method for producing a fiber-reinforced plastic product according to any one of claims 1, 3 and 4.

11. The non-contact heating method is an induction heating method. A method for producing a fiber reinforced plastic product according to claim 10.

12. In the first pressurizing step, a mold made of a non-magnetic material is used. A method for producing a fiber reinforced plastic product according to claim 10.

13. The heating method in the second pressurizing step is a contact heating method. A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

14. In the second pressurizing step, a metal mold is used. A method for producing a fiber reinforced plastic product according to claim 13.

15. The fibers are conductive fibers. A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

16. The conductive fiber is a carbon fiber. A method for producing a fiber reinforced plastic product according to claim 15.

17. The ratio of the fiber to the resin used in the additive manufacturing process is (volume of the resin) / (volume of the fiber+volume of the resin)=30 / 100 to 55 / 100. A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

18. The resin is a thermosetting resin. A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

19. The resin is a thermoplastic resin. A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

20. In the first pressurizing step, a mold having at least a lower mold, a middle mold, and an upper mold is used, The lower mold has a curved surface portion, the upper mold has a curved surface portion, the curved surface portion of the upper mold corresponds to the curved surface portion of the lower mold, The middle mold has a guide portion that guides a product obtained through the additive manufacturing technology process to the lower mold side, The middle mold is placed on the lower mold, the product obtained through the additive manufacturing technology process is placed on the guide part of the middle mold, the upper mold is placed on the product placed on the guide part, and pressure is applied between the lower mold and the upper mold, forming a curved part corresponding to the curved surface part in the product existing between the curved surface part of the lower mold and the curved surface part of the upper mold. A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

21. The middle die has a flat surface on an upper surface and a curved surface portion on a lower surface corresponding to the curved surface portion of the lower die, The guide portion is a gap portion provided in the vertical direction of the medium-sized mold, The gap is connected to the curved surface of the lower die. A method for producing the fiber reinforced plastic product of claim 20.

22. In the second pressurizing step, a mold having at least a lower mold and an upper mold is used, the upper mold and the lower mold have a cavity corresponding to a final product shape when the upper mold is placed relative to the lower mold, the cavity is formed by a groove formed on a surface of the upper mold and a groove formed on a surface of the lower mold, The groove has a generally U-shaped cross section, The product obtained through the first pressurizing step is placed on the lower mold, the upper mold is placed on top of the product placed on the lower mold, and pressure is applied between the lower mold and the upper mold. A method for producing a fiber-reinforced plastic product according to claim 1 or 4.

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