JP7598770B2 - Manufacturing method of carbon fiber composite - Google Patents

Description

The present invention relates to a carbon fiber composite, a carbon fiber composite laminate, and a method for producing a carbon fiber composite.

Carbon Fiber Reinforced Plastic (CFRP) is a fiber-reinforced plastic that uses carbon fiber as a reinforcing material. CFRP is lightweight and strong, so it is used in a wide range of fields, such as as a component material for automobiles and aircraft. An example of an intermediate material used in the production of fiber-reinforced composite materials is prepreg, which is a reinforcing fiber base material impregnated with a matrix resin.

Conventionally, thermosetting resins have been mainly used as matrix resins, but they have issues with limited application due to poor processability when molding the prepreg into the desired shape after production and difficulties in adding weather resistance.

For this reason, research into carbon fiber reinforced thermoplastic resin (CFRTP), which uses a thermoplastic resin as the matrix resin, is becoming more and more popular. By using a thermoplastic resin as the matrix resin, the workability and weather resistance of the prepreg can be improved (see, for example, Patent Document 1).

However, carbon fibers are generally used in the form of a sheet-like woven material aligned in a specific direction, and thermoplastic resins have a higher melt viscosity than thermosetting resins, posing the problem of poor impregnation into carbon fibers and the gaps between the fibers.

In order to improve the impregnation of carbon fibers when a thermoplastic resin is used as the matrix resin, for example, CFRTP using a polyurethane emulsion (aqueous emulsion of thermoplastic polyurethane) as the matrix resin is known (for example, see Non-Patent Document 1).

More specifically, as an example of CFRTP that uses polyurethane emulsion as the matrix resin, a unidirectionally stitched carbon fiber woven material is immersed in polyurethane emulsion while degassing with a roller, and after drying, multiple sheets of this material are stacked and hot pressed to obtain a CFRTP molded body.

JP 2019-172798 A

Summary of the 52nd Academic Conference of the College of Industrial Technology, Nihon University (2019-12-7) 1-36

However, the properties of CFRTP as disclosed in Non-Patent Document 1 are characterized by the resin emulsion used, so it is necessary to develop a dedicated resin emulsion for each object to be molded, which poses the problem of limited freedom in performance and appearance design. To address this issue, it is possible to use a crosslinking agent in the resin emulsion, but there is also a demand to avoid the use of a separate solvent from the standpoint of increased costs and workability.

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a method for producing a carbon fiber composite that uses a thermoplastic resin as a matrix resin and that allows easy design of performance and appearance.

In order to solve the above problems, the present invention proposes the following means.
That is, the method for producing a carbon fiber composite of the present invention is a method for producing a carbon fiber composite having a core portion formed by impregnating a fiber base material containing carbon fibers with a first resin containing a thermoplastic resin to form a film, and a coating portion containing a second resin that covers the surface of the core portion, the core portion and the coating portion being welded to each other, and is characterized by having an impregnation/film-forming process of impregnating the fiber base material with the first resin, and then forming a film of the first resin to obtain the core portion, a temporary fixing process of temporarily fixing the coating portion to the surface of the core portion, and a welding process of welding the coating portion and the core portion to obtain the carbon fiber composite .

In addition, in the present invention, the coating portion may have a first region made of the second resin and a second region made of a third resin having a composition different from that of the second resin.

The present invention provides a carbon fiber composite, a carbon fiber composite laminate, and a method for manufacturing a carbon fiber composite that uses a thermoplastic resin as a matrix resin and allows easy design of performance and appearance.

1 is an enlarged cross-sectional view showing a main portion of a carbon fiber composite according to a first embodiment of the present invention. FIG FIG. 4 is an enlarged cross-sectional view showing a main portion of a carbon fiber composite according to a second embodiment of the present invention. FIG. 11 is an enlarged cross-sectional view showing a main portion of a carbon fiber composite according to a third embodiment of the present invention. 1 is an enlarged cross-sectional view showing a main portion of a carbon fiber composite laminate according to a first embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view showing a main portion of a carbon fiber composite laminate according to a second embodiment of the present invention. FIG. 11 is an enlarged cross-sectional view showing a main portion of a carbon fiber composite laminate according to a third embodiment of the present invention. 1A to 1C are enlarged cross-sectional views of a main portion, illustrating a stepwise method for producing a carbon fiber composite according to a first embodiment of the present invention. 1A to 1C are enlarged cross-sectional views of a main portion showing a stepwise method for producing a carbon fiber composite laminate according to a first embodiment of the present invention. 5A to 5C are enlarged cross-sectional views of essential parts showing a step-by-step method for producing a carbon fiber composite laminate according to a second embodiment of the present invention.

The following describes a carbon fiber composite, a carbon fiber composite laminate, a method for producing a carbon fiber composite, and a method for producing a carbon fiber composite laminate according to one embodiment of the present invention, with reference to the drawings. Note that each embodiment shown below is specifically described to provide a better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified. Also, the drawings used in the following description may show essential parts enlarged for the sake of convenience in order to make the features of the present invention easier to understand, and the dimensional ratios of each component may not necessarily be the same as in reality.

(Carbon fiber composite: first embodiment)
FIG. 1 is an enlarged cross-sectional view of a main portion of a carbon fiber composite according to a first embodiment of the present invention.
The carbon fiber composite 1 has a core portion 13 including a first resin layer 12 formed by impregnating a fiber substrate 11 containing carbon fibers with a matrix resin (first resin) containing a thermoplastic resin.

The fiber substrate 11 may be carbon fiber alone, or may be a mixture of carbon fiber and other fibers, such as aramid fiber, nylon (registered trademark) fiber, high-strength polyester fiber, glass fiber, boron fiber, alumina fiber, or silicon nitride fiber mixed with boron fiber.

Examples of carbon fibers include pitch-based carbon fibers and polyacrylonitrile-based carbon fibers. The form of the carbon fibers is not particularly limited, and examples include woven fabrics, nonwoven fabrics, sheets of continuous fibers aligned in one direction, and short fibers made of continuous fibers cut to a certain length.

Such a first resin layer 12 prevents the fiber base material 11 from unraveling unexpectedly and promotes bonding with further resin. That is, it enables lamination of a plurality of core parts 13 together and also enables lamination of another functional layer, for example, the covering part shown in the second embodiment, on the surface.
The first resin layer 12 is only required to be formed so as to fill at least the gaps between the fibers of the fiber base material 11 , and may also be formed so as to cover the surface of the fiber base material 11 .

The matrix resin constituting the first resin layer 12 may contain at least a thermoplastic resin, and examples of the thermoplastic resin include polyvinyl chloride resin, polyvinyl acetate resin, acrylic resin, polyethylene resin, polypropylene resin, polyamide resin, polyester (polyethylene terephthalate resin, polybutylene terephthalate resin, etc.), polycarbonate resin, polyamideimide resin, polyphenylene oxide resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyetherimide resin, polystyrene resin, acrylonitrile-butylene-styrene copolymer resin, polyphenylene sulfide resin, and acrylonitrile-styrene mixed resin.
For example, polyvinyl chloride resin, polyvinyl acetate resin, acrylic resin, polyethylene resin, and polypropylene resin are preferred from the standpoint of handling and cost, and powder or liquid form (including emulsion, etc.) of these can be used.
In this embodiment, a polyvinyl chloride resin that has excellent impregnation properties for the fiber base material 11 is used as the matrix resin.

The matrix resin constituting the first resin layer 12 may be one type or a mixture of two or more types.
Depending on the application, the matrix resin may contain additives such as flame retardants, weather resistance improvers, antioxidants, heat stabilizers, UV absorbers, plasticizers, lubricants, colorants, compatibilizers, and conductive fillers.

(Carbon fiber composite: second embodiment)
FIG. 2 is an enlarged cross-sectional view of a main portion showing a carbon fiber composite according to a second embodiment of the present invention.
The same components as those in the first embodiment are given the same reference numbers, and duplicated explanations will be omitted.
The carbon fiber composite 10 has a core portion 13 including a first resin layer 12 formed by impregnating a fiber substrate 11 containing carbon fibers with a matrix resin (first resin) containing a thermoplastic resin, and a coating portion 14 including a second resin that covers at least a portion of the surface of the core portion 13.

The covering portion 14 is welded to the core portion 13 and is formed to cover the core portion 13. In this embodiment, the covering portion 14 is formed to cover one side and the other side of the sheet-shaped core portion 13.

The second resin constituting the coating portion 14 can be either a thermosetting resin or a thermoplastic resin. In this embodiment, polyvinyl chloride resin is used as the second resin constituting the coating portion 14.

When a thermosetting resin is used as the second resin, examples include epoxy resin, vinyl ester resin, unsaturated polyester resin, polyimide resin, maleimide resin, and phenolic resin.

When a thermoplastic resin is used as the second resin, examples include polyvinyl chloride resin, polyvinyl acetate resin, acrylic resin, polyethylene resin, polypropylene resin, polyamide resin, polyester (polyethylene terephthalate resin, polybutylene terephthalate resin, etc.), polycarbonate resin, polyamideimide resin, polyphenylene oxide resin, polysulfone resin, polyethersulfone resin, polyetheretherketone resin, polyetherimide resin, polystyrene resin, acrylonitrile-butylene-styrene copolymer resin, polyphenylene sulfide resin, and acrylonitrile-styrene copolymer resin. Examples include polyamide (Nylon 6 (registered trademark), Nylon 66 (registered trademark), etc.), polyolefin (polyethylene, polypropylene, etc.), modified polyolefin, polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate, polyamideimide, polyphenylene oxide, polysulfone, polyethersulfone, polyetheretherketone, polyetherimide, polystyrene, acrylonitrile-butylene-styrene copolymer, polyphenylene sulfide, liquid crystal polyester, and acrylonitrile-styrene copolymer.

The second resin constituting the coating portion 14 may be the same resin as the matrix resin constituting the first resin layer 12. If the matrix resin (first resin) and the second resin are the same resin, the compatibility between the core portion 13 and the coating portion 14 during welding is increased, and the core portion and the coating portion 14 are reliably welded together.

It is also possible to use different second resins for the coating 14 on one side and the other side of the core 13. For example, a highly flexible resin can be used as the second resin for the coating 14 on one side of the core 13, and a highly hard resin can be used as the second resin for the coating 14 on the other side of the core 13. By appropriately selecting the material for the coating 14, it is possible to add functions such as increasing the strength and weather resistance of the carbon fiber composite 10.

As a result, when the carbon fiber composite 10 is attached to any material, one side and the other side of the carbon fiber composite 10 can be used appropriately. For example, if the side having the covering portion 14 formed from the highly flexible second resin is applied to a component having corners or unevenness, the carbon fiber composite 10 can be firmly attached to the surface shape of the object to be attached.

At the same time, the surface opposite the attachment surface is exposed to the covering portion 14 formed of, for example, a second resin with high hardness, thereby increasing the strength of the outer surface. In this way, it is possible to form a carbon fiber composite 10 with multiple surface characteristics that are different from one another.

By welding the covering 14 to the core 13, it is possible to form a carbon fiber composite 10 with improved design and visual functionality by utilizing the surface of the covering 14 that is compatible with the core 13 and attaching a sheet of any color or design.

In addition, the second resin constituting the coating portion 14 may contain additives such as a flame retardant, a weather resistance improver, an antioxidant, a heat stabilizer, an ultraviolet absorber, a plasticizer, a lubricant, a colorant, a compatibilizer, and a conductive filler, as necessary.
Depending on the additive, the color, gloss, flexibility, weather resistance, conductivity, strength, abrasion resistance, etc. of the resin of the covering portion 14 can be improved.

According to the carbon fiber composite 10 of this embodiment, the surface of the core portion 13 including the first resin layer 12 formed by impregnation with a matrix resin (first resin) including a thermoplastic resin is covered (decorated) with the coating portion 14 including a second resin, so that it is possible to easily design a carbon fiber composite 10 having any desired performance and appearance without being limited by the properties of the core portion 13.

(Carbon fiber composite: third embodiment)
FIG. 3 is an enlarged cross-sectional view of a main portion showing a carbon fiber composite according to a second embodiment of the present invention.
In addition, the same components as those in the carbon fiber composite body of the first embodiment are denoted by the same numbers, and duplicated explanations will be omitted.

In this embodiment, the carbon fiber composite 20 has a coating 24A formed on one side of the core 13, the coating 24A having a first region 21 made of a second resin and a second region 22 made of a third resin that is in contact with the first region 21 and has a different composition from the second resin. Also, a coating 24B made of a fourth resin is formed on the other side of the core 13.

In this embodiment, a sheet-shaped polyvinyl chloride resin is used as the second resin constituting the first region 21 of the covering portion 24A. A sheet-shaped acrylic rubber is used as the third resin constituting the second region 22 of the covering portion 24A. Furthermore, a hard PVC sheet is used as the fourth resin constituting the covering portion 24B.

In this way, by forming covering portions 24A, 24B formed by dividing multiple types of resin (second resin, third resin, fourth resin) on the core portion 13 including the first resin layer 12 formed by impregnating a matrix resin (first resin) containing a thermoplastic resin, each region can be used as a patch. This makes it possible to realize a carbon fiber composite 20 with added functions such as grip in a predetermined direction and tear prevention by any combination of patch units.

For example, if a low-friction second resin is used as the coating portion 24A and a high-friction second resin is used as the coating portion 24B, and they are formed into multiple circles in a plan view, a carbon fiber composite 20 can be formed that has anti-slip properties and a highly aesthetic appearance, such as a polka dot pattern.

In addition, for example, if an antibacterial second resin is used as the coating 24A and a second resin shaped like letters or the like is used as the coating 24B, a carbon fiber composite 20 can be formed that has antibacterial properties and can also transmit a message.

(Carbon fiber composite laminate: first embodiment)
FIG. 4 is an enlarged cross-sectional view of a main portion showing the carbon fiber composite laminate according to the first embodiment of the present invention.
In addition, the same components as those in the carbon fiber composite body of the first embodiment are denoted by the same numbers, and duplicated explanations will be omitted.

The carbon fiber composite laminate 30 of this embodiment is made by stacking a plurality of carbon fiber composites 10 of the first embodiment. Specifically, a plurality of carbon fiber composites 10 (three in this embodiment) are stacked, and the coating portions 14 of each carbon fiber composite 10 are welded together to form an integrated structure.

With a carbon fiber composite laminate 30 configured in this way, a carbon fiber composite laminate 30 with the required thickness for the desired molded product can be easily formed by simply stacking any number of carbon fiber composites 10 and welding the coating portions 14 together.

(Carbon fiber composite laminate: second embodiment)
FIG. 5 is an enlarged cross-sectional view of a main portion showing a carbon fiber composite laminate according to a second embodiment of the present invention.
The carbon fiber composite laminate 40 of the present embodiment is formed by stacking a plurality of the carbon fiber composites 10 of the first embodiment. Specifically, a plurality of (two in the present embodiment) carbon fiber composites 40A, 40B are stacked, and the covering portions 44A, 44B of the respective carbon fiber composites 40A, 40B are welded to each other to be integrated.

The coating 44A of the carbon fiber composite 40A used here is made of, for example, a sheet-shaped polyvinyl chloride resin as the second resin. The coating 44B of the carbon fiber composite 40B is made of, for example, a sheet-shaped acrylic rubber as the second resin.

In this way, the carbon fiber composite laminate 40, which is formed by welding and integrating carbon fiber composites 40A, 40B having coatings 44A, 44B made of second resins with different resin compositions, can have different properties on one side and the other side of the carbon fiber composite laminate 40. In addition, by welding and integrating carbon fiber composites 40A, 40B having coatings 44A, 44B made by combining second resins of any composition, the physical and chemical properties required for the molded product to be applied can be easily accommodated.

(Carbon fiber composite laminate: third embodiment)
FIG. 6 is an enlarged cross-sectional view of a main portion showing a carbon fiber composite laminate according to a third embodiment of the present invention.
The carbon fiber composite laminate 50 of this embodiment is configured by laminating multiple (three in this embodiment) core portions 13 that constitute the carbon fiber composite 10 of the first embodiment, and integrating a coating portion 54 made of a second resin onto the surface of this core portion laminate 51.

In this way, with the carbon fiber composite laminate 50 in which the coating portion 54 made of the second resin is welded to the surface of the core portion laminate 51 in which multiple core portions 13 are welded together, the number of layers of the core portions 13 can be arbitrarily selected to easily realize a carbon fiber composite laminate 50 that has the physical strength required for the molded product to which it is applied.

The strength of the carbon fiber composite laminate 50 can be easily increased by welding the fiber base materials 11 of the overlapping core portions 13 together so that their fiber directions are different from each other.

(Method of manufacturing carbon fiber composite, method of manufacturing carbon fiber composite laminate: First embodiment)
7A and 7B are enlarged cross-sectional views of a main part, step by step, illustrating a method for producing a carbon fiber composite laminate according to the first embodiment of the present invention. FIG. 8 is an enlarged cross-sectional view of a main part, step by step, illustrating a method for producing a carbon fiber composite laminate according to the first embodiment of the present invention.

When manufacturing the carbon fiber composite of the first embodiment and the carbon fiber composite laminate of the first embodiment, first, as shown in FIG. 7(a), the fiber base material 11 is impregnated with an impregnation liquid Q of a first resin containing a thermoplastic resin, and then, as shown in FIG. 7(b), the first resin is formed into a film to form a core portion 13 having a first resin layer 12 (impregnation and film formation process).

In this embodiment, a cross-woven carbon fiber sheet serving as the fiber base material 11 is immersed in an aqueous emulsion of polyvinyl chloride resin (first resin) serving as an impregnation liquid, and the impregnation liquid is allowed to sufficiently penetrate between the fibers of the carbon fiber sheet. After that, the carbon fiber sheet is compressed with a roller or the like to remove excess impregnation liquid.
Thereafter, the carbon fiber sheet is dried by air cooling to remove the moisture of the impregnation liquid, and a first resin (polyvinyl chloride resin) is formed into a film to obtain a core portion 13 having a first resin layer 12 .

In addition to the air-cooled drying method described above, the method of forming the first resin film after immersion in the impregnation liquid can also be, for example, to evaporate the water content of the impregnation liquid by heating, or to remove the water content of the impregnation liquid by applying pressure or reducing pressure to form the first resin layer 12.

Next, as shown in FIG. 7C, the covering portion 14 is temporarily attached to the surface of the core portion 13 obtained through the impregnation and film-forming steps (temporary attachment step).
In this embodiment, polyvinyl chloride resin films were temporarily attached as the second resin to one side and the other side of the core portion 13 in which the first resin layer 12 was formed on the fiber base material 11. A cyanoacrylate adhesive (instant adhesive) was used for the temporary attachment.

In addition, the second resin that is temporarily fixed to the surface of the core portion 13 in the temporary fixing process is not limited to a film-shaped resin molding, but may be a thick plate-shaped resin molding. In addition, the second resin may be temporarily fixed to the surface of the core portion 13 by scattering a powdered resin body (resin powder) on the core portion 13 having an adhesive applied to its surface, or by applying a liquid resin to the surface of the core portion 13.

Next, as shown in FIG. 7( d ), the covering portion 14 temporarily attached to the surface of the core portion 13 is welded to the core portion 13 to form the carbon fiber composite 10 (welding step).
In this embodiment, the covering portion 14 temporarily fixed to the surface of the core portion 13 is heated from the outside to a temperature equal to or higher than the softening temperature of the second resin while being pressurized using, for example, a hot press device, so that the second resin constituting the covering portion 14 is welded to the first resin constituting the first resin layer 12. In this way, the carbon fiber composite 10 of this embodiment can be obtained in which the covering portion 14 is firmly fixed and integrated with the surface of the core portion 13.

The means for welding the core portion 13 and the covering portion 14 in the welding process is not limited to a hot press device. For example, if the second resin constituting the temporarily fixed covering portion 14 is a resin powder or liquid resin, the second resin may be solidified by a heater device or the like and then welded to the first resin constituting the first resin layer 12.

Next, as shown in FIG. 8(a), when manufacturing the carbon fiber composite laminate 30, the carbon fiber composites 10 formed by the above-mentioned procedure are stacked in the required number (three in this embodiment). Then, as shown in FIG. 8(b), the coating portions 14 of the stacked carbon fiber composites 10 are welded together to obtain the carbon fiber composite laminate 30 (lamination welding process).

In this embodiment, three carbon fiber composites 10 are stacked and heated and pressurized by a hot press device to weld and integrate the three carbon fiber composites 10, forming a carbon fiber composite laminate 30.

As described above, according to the method for producing a carbon fiber composite and the method for producing a carbon fiber composite laminate of this embodiment, the surface of the core portion 13 including the first resin layer 12 formed by impregnating a matrix resin (first resin) including a thermoplastic resin is simply covered (decorated) with the coating portion 14 including the second resin, and it is possible to easily produce a carbon fiber composite 10 having any desired performance and appearance without being limited by the properties of the core portion 13, and a carbon fiber composite laminate 30 obtained by laminating the same. The obtained carbon fiber composite 10 and carbon fiber composite laminate 30 can be used as a highly versatile fiber reinforced composite material that can be used in a patch unit.

(Method for manufacturing carbon fiber composite laminate: Second embodiment)
9A to 9C are enlarged cross-sectional views of essential parts showing a stepwise method for producing a carbon fiber composite laminate according to the second embodiment of the present invention.

When producing a carbon fiber composite laminate according to this embodiment, first, as shown in FIG. 9( a), a plurality of (three in this embodiment) fiber base materials 11 are laminated to obtain a fiber laminate 11A (lamination process).
Next, as shown in Fig. 9(b), the fiber laminate 11A is immersed in an aqueous emulsion liquid (impregnation liquid Q) containing the first resin to impregnate the fiber laminate 11A with the impregnation liquid (laminate impregnation step). Next, as shown in Fig. 9(c), the fiber laminate 11A impregnated with the impregnation liquid Q is dried to form a film of the first resin, thereby obtaining a core laminate (core portion) 51.

Next, as shown in FIG. 9D, a covering portion 54 made of a second resin is temporarily attached to the surface of the core laminate (core portion) 51 (temporary attachment step).
Then, as shown in FIG. 9( e ), the covering portion 54 and the core laminate (core portion) 51 are welded together by, for example, hot pressing to obtain the carbon fiber composite laminate 50 (welding step).

Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. These embodiments and their modifications are within the scope of the invention and its equivalents as set forth in the claims, as well as the scope and gist of the invention.

Example 1
The carbon fiber composite shown in Fig. 1 was actually produced by the manufacturing method of the carbon fiber composite of the first embodiment described above. A carbon fiber sheet (fiber substrate) was impregnated with polyvinyl chloride resin (first resin) to form a film to form a core part, and a hard polyvinyl chloride resin sheet (second resin: coating part) was temporarily attached to this core part with a PVC adhesive, and then the two were integrated by a hot press device.

Then, the cross section of the carbon fiber composite of Example 1 was observed. It was confirmed that the carbon fiber composite of Example 1 was a carbon fiber composite in which the core portion itself was impregnated with polyvinyl chloride resin, and the core portion and the coating portion were in close contact with each other and integrated.

Example 2
As the second resin for covering the core portion, an acrylic rubber sheet was used on one side of the core portion and a hard polyvinyl chloride resin sheet was used on the other side to form a covering portion, thereby obtaining a carbon fiber composite of Example 2. A cyanoacrylate adhesive was used in the temporary fixing step, and a hot press machine was used in the welding step.

When the cross section of the carbon fiber composite of Example 2 thus obtained was observed with a digital microscope, it was confirmed that the carbon fiber composite had an acrylic rubber sheet firmly attached to one side of the core and a hard polyvinyl chloride resin sheet firmly attached to the other side, forming an integrated structure.

Since the carbon fiber composite of Example 2 is soft on one side and hard on the other side, it has been confirmed that a carbon fiber composite can be obtained in which the physical properties of the surface are controlled on a patch-by-patch basis, making it possible to realize a carbon fiber composite with multiple properties according to the application.

Example 3
The carbon fiber composite body according to the second embodiment shown in FIG. 4 was actually produced.
Two covering members, a sheet of polyvinyl chloride resin and a sheet of acrylic rubber, were welded to one surface of the core, and a hard PVC sheet was welded to the other surface of the core.

The carbon fiber composite of Example 3 thus obtained was confirmed to be integrated with no gaps at the boundary between the polyvinyl chloride resin and the acrylic rubber, even in a carbon fiber composite in which a coating made of two types of second resin was formed on one side of the core.

Reference Signs List 10 Carbon fiber composite 11 Fiber substrate 12 First resin layer 13 Core portion 14 Covering portion 30 Carbon fiber composite laminate

Claims (2)

A method for producing a carbon fiber composite, comprising: a core portion formed by impregnating a fiber substrate containing carbon fibers with a first resin containing a thermoplastic resin to form a film; and a coating portion containing a second resin that covers a surface of the core portion, the core portion and the coating portion being welded to each other,
an impregnation/film-forming step of impregnating the fiber base material with the first resin and then forming a film of the first resin to obtain the core portion;
a temporary fixing step of temporarily fixing the covering portion to a surface of the core portion;
and a welding step of welding the covering portion and the core portion to obtain a carbon fiber composite. 2. The method for producing a carbon fiber composite according to claim 1, wherein the covering portion has a first region made of the second resin and a second region made of a third resin having a composition different from that of the second resin.

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