Carbon fiber reinforced plastic plate and method for manufacturing the same

Abstract

A carbon fiber reinforced plastic plate having a desired strength and a method for manufacturing the same are provided. The carbon fiber reinforced plastic plate uses a papermaking body as a profile, the papermaking body comprising a phenolic resin as a thermosetting resin, one or more carbon fibers with a fiber length ranging from 10 mm to 15 mm, and aromatic polyamide fibers.

Description

Technical Field

[0001] The invention relates to a carbon fiber reinforced plastic plate and a manufacturing method thereof. Background Art

[0002] Thick carbon fiber reinforced plastic (hereinafter referred to as "CFRP") plates for cutting can be processed with high precision by superhard cutting tools in the same way as metal. The demand for CFRP plates (hereinafter referred to as "CFRP plates") is increasing due to the skyrocketing price of metal and the difficulty in obtaining them. However, even if CFRP plates are supplemented with metal, they are still insufficient in terms of strength.

[0003] A single domestic aircraft manufacturer in Japan can discharge 70 tons of carbon fiber waste per year. Therefore, the development of a method for utilizing carbon fiber waste has become an urgent issue. In the recycling of carbon fiber waste, if dry heat rollers are used, the fibers will break and fluff will occur during contact with the rollers, which may result in low quality of the carbon fiber. In addition, the recycling of carbon fiber waste requires a process such as removing the resin and an additional heating process, which complicates the process. Therefore, the recycled carbon fiber obtained by recycling carbon fiber waste is expensive. On the other hand, in the field of carbon fiber utilization, most of the recycled carbon fiber is used as non-woven fabrics for cushioning materials or sound insulation materials, so it is difficult to utilize expensive recycled carbon fiber. If recycled carbon fiber that is not impregnated with resin is used for explosion-proof tools with high added value, not only can the recycled carbon fiber be effectively utilized, but also a lightweight effect can be expected.

[0004] Achieving satisfactory strength using recycled carbon fibers is an urgent issue for promoting the use of recycled carbon fibers. So far, no carbon fibers have been selected that can produce CFRP plates with the same strength as metals. The inventors have found that by combining with a papermaking method, CFRP plates with the same strength as metals can be produced. The inventors believe that recycled carbon fibers based on a dissolution method can be used when using a papermaking method to produce CFRP plates with the same strength as metals. However, manufacturers that produce recycled carbon fibers based on a dissolution method only use recycled carbon fibers as non-woven fabrics for cushioning materials or sound insulation materials, and because the price of recycled carbon fibers is high, there is no progress in their use, and equipment investment based on a dissolution method has not progressed as expected. Therefore, the inventors have found that recycled carbon fibers based on a dissolution method are difficult to obtain. In order to increase the production of recycled carbon fibers and make recycled carbon fibers easily available, it is imperative to develop new uses for recycled carbon fibers.

[0005] Japanese Utility Model Registration No. 3225768 (Patent Document 1) relates to weight reduction by metal resinification and discloses a tool formed of carbon fiber reinforced thermoplastic resin. The tool formed of carbon fiber reinforced thermoplastic resin is slightly insufficient in strength because of the use of thermoplastic resin.

[0006] Japanese Patent No. 2907679 (Patent Document 2) discloses a tool formed of a thermosetting resin reinforced with glass fiber. In addition, Patent Document 2 discloses a tool having an outer surface covered with carbon fiber epoxy cloth as a conventional example. However, the strength of this tool is only less than 40% of the torque of a similar metal product, and its use is limited.

[0007] Japanese Patent No. 7005557 (Patent Document 3) discloses a CFRP plate and a method for manufacturing the same. Although the CFRP plate and the method for manufacturing the same can satisfy processability, smoothness after processing, and strength, the manufacturing process is complicated and it is considered difficult to cope with the case where higher strength is required.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Utility Model Registration No. 3225768

[0011] Patent Document 2: Japanese Patent No. 2907679

[0012] Patent Document 3: Japanese Patent No. 7005557 Summary of the invention

[0013] Problem that the invention aims to solve

[0014] An object of the present invention is to provide a CFRP plate achieving desired strength and a method for manufacturing the same.

[0015] Means used to solve problems

[0016] The carbon fiber reinforced plastic plate of the present invention is formed by using a papermaking body as a profile, and the papermaking body comprises: a phenolic resin as a thermosetting resin; one or more carbon fibers with a fiber length ranging from 10 mm to 15 mm; and aromatic polyamide fibers as an adhesive.

[0017] The carbon fibers of the carbon fiber reinforced plastic plate of the present invention may have two types of fiber lengths: 10 mm and 15 mm.

[0018] The manufacturing method of the carbon fiber reinforced plastic plate of the present invention comprises the following steps: using a phenolic resin as a thermosetting resin, one or more carbon fibers with a fiber length ranging from 10 mm to 15 mm, and aromatic polyamide fibers as materials, wherein the proportions of these materials are formed into 50 wt% of phenolic resin, 45 wt% of carbon fibers, and 5 wt% of aromatic polyamide fibers, and the materials are dispersed and mixed in water in a container, and paper-made in a paper-making frame, dehydrating the paper-made mixed liquid in the paper-making frame in the frame, drying the dehydrated residue and forming a profile, and then punching the profile with a Thomson knife, drying the punched profile, and heating and forming the profile with the aid of a punching machine.

[0019] In the method for producing a carbon fiber reinforced plastic plate of the present invention, the carbon fibers may have a fiber length of 10 mm and a fiber length of 15 mm, respectively, accounting for 22.5 wt % and 22.5 wt % of the carbon fibers.

[0020] There is no CFRP plate made of recycled carbon fibers by the papermaking method that has the same strength as metal. The flexural strength of the carbon fiber reinforced plastic plate of the present invention is 500 MPa or more.

[0021] The carbon fiber in the present invention is used for aircraft or electric vehicles that are light in weight and require strength. The carbon fiber is linear and can be carbon spun fiber before winding the linear fiber and impregnating the epoxy resin for commercialization. The carbon fiber is produced in the process of manufacturing genuine products and is a spun fiber or end material before being impregnated with resin in the final stage due to insufficient weight, etc. The carbon fiber can also be recycled carbon fiber that is recycled by burning or dissolving the resin of the discarded carbon fiber.

[0022] If two types of carbon fibers with different fiber lengths of 10 mm and 15 mm are used, a CFRP plate with the same strength as metal can be achieved. The bending strength of the CFRP plate is more than 500 MPa. As an example for confirming the strength of the carbon fiber reinforced plastic plate, a wrench with a thickness of 7 mm and a diameter of 17 mm was manufactured. The wrench achieved a torque of 55 N·m, which is more than twice the tightening torque of ordinary bolts. For reference, the tightening torque of ordinary bolts is 24.5 N·m.

[0023] Assume that 45wt% of the whole material is carbon fiber, the remaining 50wt% is phenolic resin, and 5wt% is aromatic polyamide fiber (trade name Toray Twaron (registered trademark)) as a binder. Among the carbon fibers, the carbon fibers with a fiber length of 10mm account for 22.5wt%, and the carbon fibers with a fiber length of 15mm account for 22.5wt%. The bending strength of the CFRP plate made of these materials is about 550MPa to about 600MPa.

[0024] It is said that in carbon fiber materials such as thermoplastic resin injection molding products, the strength of recycled carbon fiber is best when the fiber length is 8mm to 10mm. In this carbon fiber material, if the fiber length of recycled carbon fiber is shorter than this, there is no strength. In addition, if the fiber length of recycled carbon fiber is longer than this, part of the carbon fiber will appear in the product like a thorn, so it cannot be used. The bending strength of this carbon fiber material is about 450MPa to 480MPa, which is not strong enough as a CFRP plate and cannot be used.

[0025] From this, the inventors were able to clarify the optimum carbon fiber length in a CFRP sheet produced by a papermaking method using a mixture of a thermosetting resin and carbon fibers as a material in order to achieve a flexural strength of 500 MPa or more.

[0026] The CFRP plate of the present invention can provide a CFRP plate that is lightweight and has a bending strength equivalent to that of steel, and can provide explosion-proof specifications based on the characteristics of the material.

[0027] Carbon fibers that do not contain thermoplastic resins or thermosetting resins are suitable for papermaking, and since recycled carbon fibers from which these resins have been removed by burning or dissolving methods can be utilized, their contribution to the environment is outstanding. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a perspective view of the CFRP plate of Example 1.

[0029] Figure 2 1 is a flowchart showing the method for manufacturing the CFRP plate according to the first embodiment.

[0030] Figure 3 This is a table showing the test results of the bending strength of the tool of the CFRP plate manufactured using the carbon fiber with a fiber length of 9 mm as the material of the comparative example.

[0031] Figure 4 This is a table showing the test results of the bending strength of the tool of the CFRP plate of Example 1.

[0032] Figure 5 This is a table showing the results of a performance evaluation test of a tool for a CFRP plate of Example 2.

[0033] Figure 6 This is an enlarged photograph of a main part of the torque measurement test of the tool of the CFRP plate of Example 2.

[0034] Figure 7 This is a photograph of the entire main part of the torque measurement test of the tool of the CFRP plate of Example 2.

[0035] Figure 8 This is a perspective view of a tool for a CFRP plate according to the second embodiment.

[0036] Fig. 9 This is a table showing the test results of the bending strength of carbon fibers at different fiber lengths. DETAILED DESCRIPTION

[0037] Regarding Example 1 which embodies the CFRP plate of the present invention, Figure 1 While explaining.

[0038] <Example 1>

[0039] like Figure 1 As shown, the CFRP plate of Example 1 is a thick plate with a thickness of 5 mm and a length and width of 90 mm and 70 mm. The shape of the CFRP plate can be changed to make a tool such as a wrench or a ratchet wrench by changing the shape of the mold. In addition, by changing the mold and the punch, a large tool can also be manufactured.

[0040] like Figure 2 As shown, the manufacturing method of CFRP plate utilizes papermaking method. The manufacturing method comprises: 1. crushing step, 2. mixing step, 3. papermaking step, 4. dehydration and punching step, 5. drying step, 6. punching step and 7. press forming step. 1. In the crushing step, the carbon fiber is cut into a predetermined fiber length. 2. In the mixing step, the carbon fiber, phenolic resin and aromatic polyamide fiber are added to a container filled with water for dispersion and mixing. 3. In the papermaking step, the mixed liquid is papered in a papermaking frame. 4. In the dehydration and punching step, the mixed liquid after papermaking in the papermaking frame is dehydrated, and the profile after dehydration and punching is formed. 5. In the drying step, the profile is dried. 6. In the punching step, the dried profile is punched with a Thomson knife in a desired shape, such as a plate or tool shape. 7. In the press forming step, the water content of the punched profile is adjusted, and it is punched by a punching machine to complete the forming. The materials of CFRP plates are phenolic resin, carbon fiber and aromatic polyamide fiber.

[0041] The papermaking method in the papermaking process is a well-known method. The purpose of the papermaking process is to efficiently fix the resin to the fiber. The details of the papermaking method are described in Japanese Patent Gazette No. 2001-123386. In this papermaking method, dispersed water in which heat-resistant fibers are dispersed is stored in a water storage tank having a plurality of openable and closable drainage holes formed on the bottom surface, the drainage holes of the water storage tank are opened at the same time to release the dispersed water, and a papermaking tank provided below the water storage tank is used to receive the dispersed water falling from the water storage tank, and then the heat-resistant fibers are scooped with a scooping net provided in the papermaking tank by draining water from the papermaking tank.

[0042] The carbon fiber is a recycled carbon fiber that is a defective product when making carbon fiber before spun and impregnated with resin. The manufacturing method of the CFRP plate of Example 1 is described in detail. 1. In the crushing process, the recycled carbon fiber is cut into fiber lengths of 10 mm and 15 mm. 2. In the mixing process, 5 wt% of aromatic polyamide fiber, 50 wt% of thermosetting resin, i.e. phenolic resin, and 22.5 wt% of each of carbon fiber with a fiber length of 10 mm and carbon fiber with a fiber length of 15 mm are dispersed and mixed in a large amount of water in the container. 3. In the papermaking process, the mixed liquid is papered in a papermaking frame. 4. In the dehydration and punching process, the mixed liquid after papermaking in the papermaking frame is dehydrated to form a profile. 5. In the drying process, the profile is dried at 80°C for 3 hours. 6. In the punching process, punching is performed using a Thomson knife in the shape of a plate. 7. In the punching process, pressurized and heated forming is performed. Drying is to control the moisture content of the profile to about 10%. The heating temperature is 140°C, and in order to obtain a 5mm thick molded product, it is pressed for 5 minutes using a 150-ton press.

[0043] The experimental results of the bending strength of the CFRP plate of Example 1 were Figure 4 Shown. Figure 4 In the figure, "10 / 50% + 15 / 50%" means that among the carbon fibers accounting for 45wt% of the materials of the CFRP plate of phenolic resin, carbon fibers and aromatic polyamide fibers, the carbon fibers having a fiber length of 10mm and the carbon fibers having a fiber length of 15mm each account for 50wt%. The maximum value of the bending strength of the CFRP plate of Example 1 is 672.16MPa, so that a larger value can be achieved. The average value of the bending strength of N number 40 is 547.01MPa, and the CFRP plate can be used as a handheld tool.

[0044] As a comparative example, a CFRP plate of the same shape was manufactured by the same manufacturing method as in Example 1 using 5 wt % of aromatic polyamide fiber, 50 wt % of phenolic resin as a thermosetting resin, and 45 wt % of a carbon fiber with a fiber length of 9 mm as materials. Figure 3 The experimental results of the bending strength of the CFRP plate of the comparative example are shown. It is said that the bending strength of hand tools needs to be 500 MPa or more, preferably 550 MPa or more, and more preferably 600 MPa or more. The average value of the bending strength of the CFRP plate of the comparative example with N number 40 is 479.03 MPa, which is insufficient for hand tools.

[0045] Fig. 9 The test results of the bending strength of CFRP plates at different fiber lengths of carbon fibers are shown. Fig. 9CFRP plates A to D are plates made of two types of carbon fibers with different fiber lengths. CFRP plates A to C are plates in which the ratio of fiber length 10 mm and fiber length 15 mm is different among the carbon fibers accounting for 45 wt% of the materials of the CFRP plates (phenolic resin, carbon fibers, and aromatic polyamide fibers). CFRP plate A is a plate in which carbon fibers with a fiber length of 10 mm account for 90 wt% and carbon fibers with a fiber length of 15 mm account for 10 wt%. CFRP plate B is a plate in which carbon fibers with a fiber length of 10 mm account for 70 wt% and carbon fibers with a fiber length of 15 mm account for 30 wt%. CFRP plate C is the CFRP plate of Example 1 described above. CFRP plate D is a plate in which carbon fibers with a fiber length of 10 mm account for 50 wt% and carbon fibers with a fiber length of 20 mm account for 50 wt% of the carbon fibers accounting for 45 wt% of the materials of the CFRP plates. Although the maximum value of the bending strength of CFRP plate D is larger than that of CFRP plates A to C, the average value of the bending strength of N number 40 is smaller.

[0046] exist Fig. 9 Among them, CFRP plates of E to M are plates made of carbon fibers with one fiber length. The bending strength of the CFRP plates made of two types of carbon fibers with different fiber lengths tends to be greater than that of the CFRP plates made of carbon fibers with one fiber length.

[0047] In the papermaking method, the fiber length of carbon fiber is expected to be the strongest when it is less than 9mm, which is considered to be good. It is known that CFRP plates ( Fig. 9 The bending strength of the CFRP plate (in the middle F) is about 450MPa, which is less than 500MPa and cannot be used. It is known that carbon fiber with a fiber length of 10mm to 15mm can be used. By adjusting the length of the carbon fiber of the end material that was considered unusable in the papermaking method, a bending strength of more than 550MPa was successfully achieved. Fig. 9 It can be seen from the CFRP plate of C in the figure (a plate in which 50wt% of the carbon fibers accounting for 45wt% of the material of the CFRP plate are carbon fibers with a fiber length of 10mm and 50wt% are carbon fibers with a fiber length of 15mm) that the desired strength can be achieved by using two types of carbon fibers with different fiber lengths. Furthermore, even carbon fibers with a fiber length of 10mm to 15mm, which were considered unusable, can achieve a bending strength of approximately 600MPa or more by using the papermaking method.

[0048] <Example 2>

[0049] like Figure 8As shown, a wrench of a handheld tool is manufactured as a form of a CFRP plate. In the manufacturing method of the tool, in the mixing process, 5wt% of aromatic polyamide fiber, 50wt% of thermosetting resin, i.e. phenolic resin, and 22.5wt% of each material of 10mm fiber length carbon fiber and 15mm fiber length carbon fiber are mixed into a container filled with water, dispersed and mixed in the container, and papered in a papermaking frame. The mixed liquid after papermaking is dehydrated to form a profile. The thickness of the formed profile is 10mm. 10 profiles are overlapped to a thickness of 100mm, and preliminary drying is performed, such as by natural drying, to facilitate cutting with a Thomson knife. After that, punching is performed with a tool-shaped Thomson knife, the moisture content is adjusted, and hot stamping is performed at 180°C to manufacture a 7mm thick 17mm caliber wrench.

[0050] The manufacturing method of the wrench of the CFRP plate tool of Example 2 is described in detail for the steps after the mixing step. Although the numerical values ​​vary depending on the production volume, this is to make the papermaking method easier to understand, and therefore the case of small-scale production is described.

[0051] 1.Pour water into a bucket (container). (22.5L (liters) 4 cups)

[0052] 2. Add aromatic polyamide fiber, phenolic resin and carbon fiber materials into the barrel (except defoaming, dispersing and coagulant)

[0053] 3. Use a dissolver (mixer) to evenly disperse the materials in the water in the bucket to complete the dispersion of water. (5 minutes at 4000rpm)

[0054] 4. While manually stirring the water in the slurry bucket, add the dispersant and stir 20 times.

[0055] 5. While manually stirring the water in the slurry bucket into which the dispersed material has been added, add the coagulant and stir for about 10 times to complete the slurry.

[0056] 6. Store 3.% of dispersed water in the lower 10 cm of the papermaking frame and add 5.% of slurry.

[0057] 7. Extract water from the papermaking frame.

[0058] 8. Use a vacuum pump or ring blower to extract a certain amount of moisture from the papermaking sheet.

[0059] 9. Take out the sheet from the papermaking frame and dehydrate it by punching. (Every 1cm 2 30kg to 40kg pressure for 3 minutes)

[0060] 10. Punch the dehydrated sheet using a Thomson knife in a hydraulic shearing machine. (Hereafter, it is called a profile instead of a sheet)

[0061] 11. Arrange the profiles in the dryer for drying. (Current conditions: 80℃×4.5 hours)

[0062] 12. Measure the weight of the dried profiles and separate them.

[0063] 13. Combine the profiles separated by weight into the product weight.

[0064] 14. Stack multiple combined profiles and heat to form a flat plate. (Preliminary forming, current conditions: 1 cm per 2 100kg pressure, 80℃ x 1 minute)

[0065] 15. Heat and shape the flat profile. (Current conditions: 1 cm 2 1t pressure, 180℃×1 minute per 1mm thickness)

[0066] 16. The molded product removed from the mold is trimmed to complete.

[0067] The carbon fiber used here is recycled carbon fiber. Here, as an example, a method for manufacturing recycled carbon fiber, namely the dissolution method, is described. The method for manufacturing recycled carbon fiber by the dissolution method is well known. For example, Japanese Patent Publication No. 2020-37638 shows a resin dissolving device for the dissolution method. The resin dissolving device dissolves the resin material contained in the carbon fiber reinforced plastic. The resin dissolving device has a dissolving tank, a gas inlet and a guide wall. The dissolving tank is filled with a solution containing sulfuric acid and a carbon fiber reinforced plastic with controlled temperature and concentration. The gas inlet is arranged on the lower surface of the dissolving tank, and the bubbles are introduced into the processing space provided in the dissolving tank to generate bubbles. The guide wall is extended upward in a manner to surround the gas inlet in the processing space, and guides the solution rising with the bubbles. The carbon fiber reinforced plastic is put into the outside of the guide wall, and a through hole is provided near the bottom of the dissolving tank of the guide wall. The through hole is used to prevent the carbon fiber contained in the carbon fiber reinforced plastic from invading the inner side of the guide wall, and to convect the solution in the processing space. Recycled carbon fiber can be manufactured using the resin dissolving device.

[0068] Figure 5 The performance test results of the wrench of the CFRP plate tool of Example 2 were obtained from a public testing institute, and the basis for the evaluation is shown in the remarks column. According to the performance test results, the CFRP plate tool of Example 1 passed the tool strength, tightening torque, impact test, and live-current test and can be used as a handheld tool. Figure 6 as well as Figure 7: is a figure which shows the torque test of the wrench of Example 2. The general tightening torque of the standard torque table is 42N·m when the nominal diameter is M12. In contrast, the tool of the CFRP plate of Example 1 can reach 55N·m.

[0069] The wrench of Example 2 is 7 mm thick. When the thickness of the tool is set to 8 mm to 10 mm, the same profile as in Example 2 is overlapped to make a thickness of about 100 mm, and then stamped to 8 mm to 10 mm thick.

[0070] CFRP plate tools have a bending strength roughly equivalent to iron hand tools, and can be provided with hand tools that are one-quarter to one-seventh the weight, which is beneficial for explosion prevention or ensuring the safety of high-altitude operations.

[0071] When comparing a 3mm thick CFRP plate made of recycled carbon fiber with a 1mm thick SUS (stainless steel) plate, the bending strength is 578MPa vs. 502MPa, and the tensile load strength is 6400MPa vs. 6433N, which confirms that they are roughly equivalent in strength. This is the first time in the world that a hand tool with satisfactory strength and explosion-proof performance has been formed by combining waste, thermosetting resin, and papermaking.

[0072] Although a wrench is shown as the tool for the CFRP plate, a wrench or the like, which is a hand-held tool, can also be used to adjust the pressing pressure or time by changing the shape of the draft edge and depending on the size of the hand-held tool.

[0073] The present invention not only has the great advantage of achieving lightweight and explosion-proof functions of CFRP plates through papermaking and thermosetting resin, but also because it can use recycled carbon fibers, there is no need for melting operations at temperatures of several thousand degrees to obtain tools made of iron or stainless steel, thus making a huge contribution to the reduction of carbon dioxide.

[0074] In the past, in aerial work, tools were held at the waist, which sometimes caused waist pain due to their weight. However, if the present invention is used as a tool, it is expected that the waist pain will be relieved because of its light weight, and there will be no serious disaster caused by the tool falling. Furthermore, if the present invention is used as a tool, it will not rust like metal, so it can be expected to be used in the food industry.

[0075] According to the present invention, the most suitable carbon fiber for manufacturing CFRP panels by a papermaking method using a mixture of a thermosetting resin and carbon fiber can be clarified. There are many recycled carbon fibers or carbon fiber end materials that are difficult to utilize before resin impregnation, and there is no method for utilizing them. According to the present invention, it is possible to establish the use of carbon fiber end materials used in aircraft, etc., which are said to be produced more than 70 tons per year, to manufacture CFRP panels.

[0076] The final use destination of recycled carbon fiber is non-woven cushioning materials or sound insulation materials, so the strength of the molded product using the papermaking method is insufficient in strength measurement. The present invention can find a commercially available carbon fiber that solves the insufficient strength of the papermaking method and establish a CFRP plate with satisfactory strength and a method for manufacturing the same. In particular, the recycled carbon fiber material used is cheaper than the product price, that is, the original material price, and can be manufactured more cheaply than existing competitive products.

[0077] Industrial Applicability

[0078] The present invention is extremely excellent in terms of being an environmental protection measure, preventing fires through explosion-proofing, and reducing weight. This is a CFRP cutting plate made of thick plate that can be processed with high precision like metal by superhard cutting tools, and can be used as a basis for electronic components, etc. It can be used for connector components, end effectors of insertion robots, spacers (spacers) connecting robot bodies and action claws, etc. In addition, in the case of tools, etc., it can be expected to be widely used in industries such as the gasoline chemical industry, the oil and gas industry, explosive manufacturing plants, shipyards, the aviation industry, the medical industry, and the food industry for mechanical maintenance. Furthermore, it can also be expected to replace parts that rely on metal, such as gears or robot arms that are lightweight and require strength.

Claims

1. A carbon fiber reinforced plastic plate, in, The profile is formed by overlapping multiple layers of profiles, the profile is formed by a papermaking body, and the shape of the profile is punched into the shape of the product. The papermaking body comprises: Phenolic resins as thermosetting resins; One or more carbon fibers having a fiber length ranging from 10 mm to 15 mm, excluding carbon fibers having a fiber length less than 10 mm; and Aramid fiber as a binder, The proportions of these materials are 50wt% phenolic resin, 45wt% carbon fiber, and 5wt% aromatic polyamide fiber. The carbon fiber reinforced plastic plate has a bending strength of 500 MPa or more.

2. The carbon fiber reinforced plastic plate according to claim 1, in, The carbon fibers are of two types: 10 mm in fiber length and 15 mm in fiber length. The carbon fibers with a fiber length of 10 mm account for 22.5 wt % of the whole material, and the carbon fibers with a fiber length of 15 mm account for 22.5 wt % of the whole material.

3. A method for producing a carbon fiber reinforced plastic plate, which is a method for producing the carbon fiber reinforced plastic plate according to any one of claims 1 and 2, in, Phenolic resin as a thermosetting resin, one or more carbon fibers with a fiber length ranging from 10 mm to 15 mm and excluding a fiber length less than 10 mm, and aromatic polyamide fibers are used as materials respectively, and the proportions of these materials are formed into 50 wt% of phenolic resin, 45 wt% of carbon fibers and 5 wt% of aromatic polyamide fibers, dispersed and mixed in water in a container, and paper-made in a papermaking frame, and the papermaking mixed liquid in the papermaking frame is dehydrated in the frame, and the dehydrated residue is dried and formed into a profile, and then the profile is punched out with a Thomson knife, and the punched profile is dried and overlapped in multiple layers, and is heated and formed by a punching machine.

4. The method for manufacturing a carbon fiber reinforced plastic plate according to claim 3, in, Among the carbon fibers, the carbon fibers with a fiber length of 10 mm account for 22.5 wt % of the entire material, and the carbon fibers with a fiber length of 15 mm account for 22.5 wt % of the entire material.

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