JP2012167230A - Method for producing prepreg - Google Patents

Abstract

The present invention provides a method for producing a prepreg having a drapeability at a low cost, in which a fiber base material can be sufficiently impregnated with a resin even when a thick prepreg is produced.
A method for producing a prepreg, in which a liquid resin composition is sandwiched between fiber substrates made of continuous fibers and the fiber substrate is impregnated with the resin composition.
[Selection figure] None

Description

  The present invention relates to a method for producing a prepreg.

  Fiber reinforced composite materials are used in various applications because of their light weight and high strength characteristics. In particular, long fiber reinforced composite materials have light and high strength, and also have high rigidity characteristics. As an alternative to metal materials, such as airplanes, ships, rail cars, automobiles, golf clubs, tennis rackets, etc. Widely used in industrial applications such as aircraft.

Many fiber reinforced composite materials are manufactured by a method of laminating and curing a prepreg impregnated with an uncured thermosetting resin on a fiber substrate made of reinforced fibers such as carbon fibers because of its high performance. .
The performance required for this prepreg is, of course, excellent in physical properties such as strength after curing (that is, when it becomes a fiber-reinforced composite material), but also excellent in handling properties, that is, draping (flexible) Is).

  In order to obtain a fiber-reinforced composite material having excellent physical properties such as strength, it is important how voids (voids) generated in the inside can be reduced. If there is an unimpregnated part of the thermosetting resin on the fiber base material of the prepreg, the unimpregnated part remains as a void in the fiber-reinforced composite material that is the molded product, and the void becomes a defect in the fiber-reinforced composite material and its strength decreases. To do.

Conventionally, as a method for satisfactorily impregnating a fiber base material with a thermosetting resin, a thermosetting resin and a solvent are mixed, and after impregnating the fiber base material with the fiber base material, the solvent is removed by drying to obtain a prepreg. Lacquer method and varnish method were used.
However, this method has a problem that the solvent cannot be sufficiently removed, and the solvent remaining in the prepreg is vaporized during the molding, and voids are generated in the fiber-reinforced composite material. If the drying temperature is raised in order to sufficiently remove the solvent, the thermosetting resin is cured at the prepreg stage, and it is difficult to remove the solvent sufficiently at this stage.

  In order to solve this problem, in recent years, without using a solvent, the viscosity of the thermosetting resin is reduced by heating to produce a thermosetting resin film (resin film). A so-called hot melt film method has been proposed in which a fiber base material is impregnated with a thermosetting resin by being attached to one side of a fiber base material aligned in the direction and heated and / or pressurized to obtain a prepreg.

By the way, in order to shape | mold a fiber reinforced composite material using a prepreg, it is necessary to laminate | stack the prepreg to desired thickness. In particular, since structural parts of moving bodies such as ships, railway vehicles, and automobiles are thick, when the fiber reinforced composite material is used for these applications, it is necessary to increase the number of prepregs stacked. Therefore, a thick prepreg has been demanded.
In order to obtain a thick prepreg, the fiber substrate may be thickened. However, in the above-described hot melt film method, a resin film is attached to one side of a fiber base material in which continuous fibers are aligned, and the thermosetting resin is impregnated by applying pressure from the outside. That is, when the fiber base becomes thick, the thermosetting resin cannot be sufficiently impregnated from one side. Therefore, in the hot melt film method, from the impregnation principle, it is difficult to produce a prepreg having a thickness and sufficiently impregnated with a thermosetting resin.

  Thus, for example, Patent Document 1 discloses a method in which a resin film is attached to both surfaces of a fiber base material and impregnated with a thermosetting resin.

JP-A 63-170427

As described in Patent Document 1, in the method of attaching and impregnating a resin film on both surfaces of a fiber base material, the air in the fiber base material is moved out of the fiber base material while substituting the thermosetting resin. There is a need.
However, since the fiber base material is sandwiched between the resin films, it is difficult for air in the fiber base material to escape and it is difficult to sufficiently impregnate the thermosetting resin. As a result, the air in the fiber substrate was likely to remain in the prepreg. This was more remarkable as the basis weight of the fiber base material increased, that is, as the fiber base material became thicker.
The remaining air in the prepreg is a void in the prepreg, and this void becomes a defect of the fiber-reinforced composite material obtained by laminating and curing the prepreg.

On the contrary, when the fiber base material is excessively impregnated with the thermosetting resin, the resulting prepreg tends to be stiff and the drapability tends to be lowered. In particular, the larger the basis weight of the fiber base material, the more remarkable.
Furthermore, in the hot melt film method, it is necessary to produce a resin film in a separate process. In addition, material costs such as process processing costs, release paper supporting the resin film, protective film protecting the resin film, and the like are high, so that the prepreg manufacturing cost tends to be high.

  The present invention has been made in view of the above circumstances, and provides a method for producing a prepreg having drapeability at a low cost, in which a fiber base material can be sufficiently impregnated even when a thick prepreg is produced. With the goal.

The method for producing a prepreg of the present invention is characterized in that a liquid resin composition is sandwiched between fiber substrates made of continuous fibers and the fiber substrate is impregnated with the resin composition.
In addition, the resin composition is sandwiched between the first fiber base material (A1) made of continuous fibers and the first fiber base material (A1) to which the resin composition is attached. It is preferable that the second fiber base material (A2) made of continuous fibers is stacked on the substrate.
Moreover, it is preferable that the sandwiching of the resin composition is performed by attaching the resin composition to a fiber base made of continuous fibers and then bending the side to which the resin composition is attached.
Furthermore, it is preferable that the resin composition contains an epoxy resin.

  According to the present invention, even when a thick prepreg is manufactured, the fiber base material can be sufficiently impregnated with the resin, and a prepreg having drapeability can be manufactured at a low cost.

It is a schematic block diagram which shows an example of the prepreg manufacturing apparatus used for this invention. (A) is a schematic block diagram which shows the other example of the prepreg manufacturing apparatus used for this invention, (b) is the fragmentary perspective view of (a).

Hereinafter, the present invention will be described in detail.
The method for producing a prepreg of the present invention is characterized in that a liquid resin composition is sandwiched between fiber substrates made of continuous fibers and the fiber substrate is impregnated with the resin composition.

[Fiber base]
The continuous fiber constituting the fiber base material is a reinforcing fiber, and various fibers can be used according to the purpose of use of the fiber-reinforced composite material.
Specific examples of the continuous fiber used in the present invention include carbon fiber, graphite fiber, aramid fiber, silicon carbide fiber, alumina fiber, boron fiber, tungsten carbide fiber, and glass fiber. These may be used individually by 1 type and may be used in combination of 2 or more type.

As the continuous fiber, carbon fiber and graphite fiber are preferable because they are excellent in specific strength and specific modulus.
As carbon fiber and graphite fiber, all kinds of carbon fiber and graphite fiber can be used depending on the application, but high-strength carbon fiber with a tensile elongation of 1.5% or more shows strength of fiber-reinforced composite material. Suitable for. Among them, a high strength high elongation carbon fiber having a tensile strength of 4.4 GPa or more and a tensile elongation of 1.7% or more is more preferable, and a high strength high elongation carbon fiber having a tensile elongation of 1.9% or more is most suitable. Yes. Carbon fibers and graphite fibers may be used in combination with other reinforcing fibers.

  Examples of the form of the fiber base include a form in which continuous fibers are aligned in one direction, a tow form, a woven form, and a non-crimp fabric form. Among these, a form in which continuous fibers are aligned in one direction is preferable in terms of strength development.

  The fiber basis weight of the fiber base material can be freely set according to the purpose of use of the fiber reinforced composite material.

[Resin composition]
The resin composition used in the present invention contains a thermosetting resin and a curing agent.
The viscosity of the resin composition is not particularly limited, but is preferably lower from the viewpoint of impregnation properties. Specifically, the viscosity at 30 ° C. is preferably 1 to 1 × 10 ⁵ Pa · sec.
In addition, when the resin composition is sandwiched between the fiber base material, it will be described in detail later, but it may be liquid when adhering to the fiber base material and when impregnating the fiber base material. It may be in a solid state at room temperature.

(Thermosetting resin)
Thermosetting resins include phenolic resin, urea resin, melanin resin, bismaleimide resin, unsaturated polyester resin, vinyl ester resin, epoxy ester resin, epoxy resin, bismaleimide / triazine resin (BT resin), cyanate ester resin, Examples include triazine resin. Among these, an epoxy resin is preferable because it is excellent in strength, heat resistance, and moldability.
These thermosetting resins may be used alone or as a mixture of two or more. Further, even a single solid resin can be used as long as it is liquid when mixed.

  Examples of the epoxy resin include a glycidyl ether type epoxy resin obtained from a compound having a hydroxyl group in the molecule and epichlorohydrin, a glycidylamine type epoxy resin obtained from a compound having an amino group in the molecule and epichlorohydrin, a molecule Glycidyl ester type epoxy resin obtained from compound having carboxyl group and epichlorohydrin, alicyclic epoxy resin obtained by oxidizing compound having double bond in molecule, dealcoholized from isocyanate and epoxy An oxazoline ring-containing epoxy resin obtained by this method, or an epoxy resin in which two or more types of groups selected from these are mixed in the molecule is used.

  Specific examples of the glycidyl ether type epoxy resin include bisphenol A type epoxy resin obtained by reaction of bisphenol A and epichlorohydrin, bisphenol F type epoxy resin obtained by reaction of bisphenol F and epichlorohydrin, resorcinol and epi Resorcinol type epoxy resin obtained by reaction of chlorohydrin, phenol novolac type epoxy resin obtained by reaction of phenol and epichlorohydrin, other polyethylene glycol type epoxy resin, polypropylene glycol type epoxy resin, naphthalene type epoxy resin, dicyclo Examples thereof include pentadiene type epoxy resins, and their positional isomers, substituted groups with alkyl groups and halogens.

A commercial item can be used as these glycidyl ether type epoxy resins.
Commercially available bisphenol A type epoxy resins include “EPON825”, “jER826”, “jER828”, “jER828”, “jER1001” (manufactured by Mitsubishi Chemical Corporation), “Epiclon 850” (manufactured by DIC Corporation). “Epototo YD-128” (manufactured by Nippon Steel Chemical Co., Ltd.), “DER-331”, “DER-332” (manufactured by Dow Chemical Co., Ltd.), “Bakelite EPR154”, “Bakelite EPR162”, “Bakelite EPR172” ”,“ Bakelite EPR173 ”,“ Bakelite EPR174 ”(above, manufactured by Bakerite AG), and the like.
Commercially available products of bisphenol F type epoxy resin include “jER806”, “jER807”, “jER1750” (manufactured by Mitsubishi Chemical Corporation), “Epicron 830” (manufactured by DIC Corporation), “Epototo YD-170”, "Epototo YD-175" (manufactured by Nippon Steel Chemical Co., Ltd.), "Bakelite EPR169" (manufactured by Bakerite AG), "GY281", "GY282", "GY285" (manufactured by Huntsman Advanced Materials) ) And the like.
Examples of commercially available resorcinol-type epoxy resins include “Denacol EX-201” (manufactured by Nagase ChemteX Corporation).
Commercially available phenol novolac type epoxy resins include “jER152”, “jER154” (manufactured by Mitsubishi Chemical Corporation), “Epiclon 740” (manufactured by DIC Corporation), “EPN179”, “EPN180” (all, Huntsman). -Advanced Material, etc.).

  Specific examples of the glycidylamine type epoxy resin include tetraglycidyldiaminodiphenylmethanes, glycidyl compounds of aminophenol and aminocresol, glycidylanilines, and glycidyl compounds of xylenediamine.

A commercial item can be used as these glycidylamine type epoxy resins.
Commercially available products of tetraglycidyldiaminodiphenylmethanes include “Sumiepoxy ELM434” (manufactured by Sumitomo Chemical Co., Ltd.), “Araldite MY720”, “Araldite MY721”, “Araldite MY9512”, “Araldite MY9612”, “Araldite MY9634”, “Araldite” “MY9663” (manufactured by Huntsman Advanced Materials), “jER604” (manufactured by Mitsubishi Chemical Corporation), “Bakelite EPR494”, “Bakelite EPR495”, “Bakelite EPR496”, “Bakelite EPR497” (above, Bakelite) Manufactured).
Commercially available glycidyl compounds of aminophenol and aminocresol include “jER630” (manufactured by Mitsubishi Chemical Corporation), “Araldite MY0500”, “Araldite MY0510”, “Araldite MY0600” (above, manufactured by Huntsman Advanced Materials) ), “Sumiepoxy ELM120”, “Sumiepoxy ELM100” (manufactured by Sumitomo Chemical Co., Ltd.), and the like.
Examples of commercially available glycidyl anilines include “GAN, GOT” (manufactured by Nippon Kayaku Co., Ltd.), “Bakelite EPR493” (manufactured by Bakelite AG), and the like.
Examples of the glycidyl compound of xylenediamine include “TETRAD-X” (manufactured by Mitsubishi Gas Chemical Company, Inc.).

  Specific examples of the glycidyl ester type epoxy resin include diglycidyl phthalate, diglycidyl hexahydrophthalate, diglycidyl isophthalate, diglycidyl dimer, and isomers thereof.

As these glycidyl ester type epoxy resins, commercially available products can be used.
Examples of commercially available products of diglycidyl phthalate include “Epomic R508” (manufactured by Mitsui Chemicals), “Denacol EX-721” (manufactured by Nagase ChemteX Corporation), and the like.
Examples of commercially available hexahydrophthalic acid diglycidyl ester include “Epomic R540” (manufactured by Mitsui Chemicals), “AK-601” (manufactured by Nippon Kayaku Co., Ltd.), and the like.
Examples of commercially available dimer acid diglycidyl ester include “jER871” (manufactured by Mitsubishi Chemical Corporation), “Epototo YD-171” (manufactured by Nippon Steel Chemical Co., Ltd.), and the like.

A commercial item can be used as an alicyclic epoxy resin. Examples thereof include “Celoxide 2021P”, “Celoxide 2081”, “Celoxide 3000” (manufactured by Daicel Chemical Industries, Ltd.), “CY179” (manufactured by Huntsman Advanced Materials), and the like.
A commercial item can be used as an oxazoline ring containing epoxy resin. For example, “Araldite AER4152” (manufactured by Asahi Kasei E-Materials Co., Ltd.) can be used.

Among the epoxy resins described above, a bisphenol A type epoxy resin is particularly preferable in terms of heat resistance and toughness.
These epoxy resins may be used individually by 1 type, and may use 2 or more types together.
From the viewpoint of impregnation properties, it is preferable that the epoxy resin has a low viscosity.

(Curing agent)
Examples of the curing agent include amines, acid anhydrides (such as carboxylic acid anhydrides), phenols (such as novolak resins), mercaptans, Lewis acid amine complexes, onium salts, imidazoles, and the like. Any structure can be used as long as it can be used. Among these, amine type curing agents are preferable.
These curing agents may be used alone or in combination of two or more. Moreover, even if it is a solid hardener by itself, if it is liquid when it is set as a resin composition, it can be used.

  Examples of amine-type curing agents include aromatic amines such as diaminodiphenylmethane and diaminodiphenylsulfone, aliphatic amines, imidazole derivatives, dicyandiamide, tetramethylguanidine, thiourea-added amines, and isomers and modified products thereof. Can be mentioned. Among these, dicyandiamide is particularly preferable in terms of excellent prepreg storage.

  These curing agents can be combined with an appropriate curing aid in order to increase the curing activity. Preferred combinations include dicyandiamide as a curing agent and 3-phenyl-1,1-dimethylurea, 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU), 3- (3 as a curing aid. -Chloro-4-methylphenyl) -1,1-dimethylurea, combinations with urea derivatives such as 2,4-bis (3,3-dimethylureido) toluene, carboxylic anhydrides and novolac resins as curing agents, Combinations with tertiary amines as curing aids, diaminodiphenyl sulfones as curing agents, urea compounds such as imidazole compounds and phenyldimethylurea (PDMU) as curing aids, monoethylamine trifluoride, amine trichloride complexes, etc. A combination with an amine complex is exemplified.

(Other)
The resin composition used in the present invention may contain one or more resins selected from the group consisting of thermoplastic resins, thermoplastic elastomers, and elastomers as additives. These additives have the role of improving the toughness of the matrix resin (thermosetting resin) and changing the viscoelasticity to optimize the viscosity, storage elastic modulus and thixotropic properties.
These additives may be used alone or in combination of two or more. Moreover, even if an additive is solid by itself, it can be used if it is liquid when it is used as a resin composition.
These additives may be dissolved and blended in the thermosetting resin, and may be arranged on the surface layer of the prepreg in the form of fine particles, long fibers, short fibers, woven fabric, nonwoven fabric, mesh, pulp and the like.

The thermoplastic resin includes a group consisting of a carbon-carbon bond, amide bond, imide bond, ester bond, ether bond, carbonate bond, urethane bond, urea bond, thioether bond, sulfone bond, imidazole bond and carbonyl bond in the main chain. A thermoplastic resin having one or more bonds selected from the above is preferably used.
Examples of such thermoplastic resins include thermoplastic resins belonging to engineering plastics such as polyacrylate, polyamide, polyaramid, polyester, polycarbonate, polyphenylene sulfide, polybenzimidazole, polyimide, polyetherimide, polysulfone, and polyethersulfone. A group is more preferably used. Among these, polyimide, polyetherimide, polysulfone, and polyethersulfone are particularly preferable in terms of excellent heat resistance.
Moreover, it is preferable that a thermoplastic resin has a reactive functional group with a thermosetting resin from a viewpoint of toughness improvement and maintenance of environmental resistance of a thermosetting resin. Examples of the reactive functional group include a carboxyl group, an amino group, and a hydroxyl group.

[Manufacture of prepreg]
In the present invention, the resin composition is first sandwiched between the fiber base materials, and then the fiber base material is impregnated with the sandwiched resin composition.
Examples of the method for sandwiching the resin composition include the following methods.
(1) The resin composition of the fiber base material (A1) after adhering the resin composition to the first fiber base material (A1) composed of continuous fibers (hereinafter referred to as “fiber base material (A1)”). A method (Method 1) in which a second fiber base material (A2) made of continuous fibers (hereinafter referred to as “fiber base material (A2)”) is overlapped on the side to which is attached.
(2) A method in which a resin composition is attached to a fiber base made of continuous fibers and then bent with the side to which the resin composition is attached inward (Method 2).

In the case of Method 1, after the fiber substrate (A2) is stacked on the fiber substrate (A1), the resin composition attached to the fiber substrate (A1) is applied to the fiber substrate (A1) and the fiber substrate (A2). Impregnate.
On the other hand, in the case of the method 2, after bending the fiber base material to which the resin composition is adhered, the fiber base material is impregnated with the resin composition.

It does not specifically limit as a method of making a resin composition adhere to a fiber base material, A well-known method can be used. Specifically, a touch roll method, a dip method, a die method, a dispenser method, and the like can be given.
In both method 1 and method 2, it is preferable that the resin composition is uniformly deposited on the fiber substrate that has been aligned. This is because if there is a gap in the resin composition adhering to the fiber substrate, density unevenness or chipped portions of the resin composition occur in the prepreg after impregnation, which may affect the physical properties of the composite material after curing. is there.

The method for impregnating the fiber composition with the resin composition is not particularly limited, and a known method can be used. Specifically, the resin composition is sandwiched between fiber base materials, and the resin composition is sandwiched between several sets of impregnation rolls and impregnated by pressurization and / or heating. The method etc. are mentioned.
The temperature at the time of impregnation is preferably 10 to 120 ° C. Moreover, as for the pressure at the time of making it impregnate by pressurization, 950N-20kN are preferable.

By the way, when the resin composition is impregnated by the hot melt film method, since the fiber base material is sandwiched by the resin film, there is no escape route for air in the fiber base material in the direction perpendicular to the plane (lamination direction) of the fiber base material. Therefore, the progress of the resin composition to the fiber base material was hindered by this air, and it was difficult to sufficiently impregnate, and air was likely to remain in the prepreg.
Even in the hot melt film method, if the resin film is attached only to one side of the fiber base material, air escapes from the other side of the fiber base material, so that hindering impregnation of the resin composition with air is suppressed, When the basis weight of the fiber base material is increased, that is, when the fiber base material is thick, it is difficult to sufficiently impregnate the resin composition from one side.
On the other hand, if the fiber base material is excessively impregnated with the resin composition, the resulting prepreg tends to be stiff and drapability tends to be reduced.

  Furthermore, in the case of the hot melt film method, it is necessary to form a resin film on the release paper or to attach a protective film for protecting the resin film to the resin film. Therefore, the resin composition needs to maintain a certain level of viscosity. If the viscosity of the resin composition is too low, the protective film is difficult to peel off from the resin film during the production of the prepreg. If the viscosity of the resin composition is further lowered, it becomes difficult to form a resin film on the release paper.

  However, according to the present invention, when the resin composition is impregnated into the fiber base material sandwiched with the resin composition, in the fiber base material from the gap between the fibers in the direction perpendicular to the plane of the fiber base material (stacking direction). Air is easy to escape. Therefore, the resin composition is sufficiently impregnated to the extent that the resin composition does not become excessive without hindering its progress. Moreover, since the air in each fiber base material is extruded as the resin composition progresses, the air hardly remains in the obtained prepreg.

Moreover, if it is this invention, the fabric weight of a fiber base material can be changed easily. Therefore, for example, if the basis weight of the fiber base material is set to half of the desired basis weight of the prepreg, the moving distance in the plane perpendicular direction when the resin composition impregnates the fiber base material sandwiching the resin composition is In the hot melt film method, it is estimated to be about half of the case where a resin film is attached to only one side of a fiber base material and impregnated.
Therefore, the present invention has better impregnation of the resin composition than the hot melt film method, and even when the prepreg is increased in weight, that is, when a thick prepreg is produced, the resin composition is applied to the fiber substrate. Can be sufficiently impregnated so as not to be excessive, and a prepreg excellent in drapeability can be obtained.

Furthermore, in this invention, there is no restriction | limiting of a viscosity like a hot-melt film method about the resin composition to be used, and a resin composition with a low viscosity can be used. The lower the viscosity of the resin composition, the better the impregnation property, so that the impregnation into each fiber base material becomes better.
In the present invention, it is possible to use a resin composition in a low viscosity region that is difficult to use in the hot melt film method. Therefore, if a low-viscosity resin composition is used, the fiber base material can be more effectively impregnated. Therefore, even when a thick prepreg is produced, the impregnation property of the resin composition is improved, and a prepreg excellent in draping property is obtained. It is done.

Here, an example of a method for producing a prepreg by sandwiching the resin composition using the method 1 will be specifically described with reference to FIG.
The prepreg manufacturing apparatus 10 shown in FIG. 1 includes a coating means 12 for attaching a resin composition to a fiber base (A1) 11a, and a resin composition attached to the fiber base (A1) 11a as a fiber base (A1). 11a and two sets of impregnation means 13 for impregnating the fiber base material (A2) 11b, a drive roll 14, a transport means 15 for transporting the fiber base material, a feeding means 16 for feeding out the protective film, and the obtained prepreg 17 And a roll-shaped winding means 18 for winding up.
The coating means 12 includes a resin bath (not shown) for storing the resin composition, and a die 12a for coating the fiber composition (A1) with the resin composition supplied from the resin bath.
The impregnation means 13 includes a pair of impregnating rolls 13a and 13b that can be heated.
The conveying means 15 includes a pair of endless metal belts 15a and 15b.

Using the prepreg manufacturing apparatus 10 shown in FIG. 1, first, the resin composition is stored in the resin bath of the coating means 12, and the resin temperature in the resin bath is maintained. Further, as the fiber base material (A1) and the fiber base material (A2), a sheet-like fiber base material in which carbon fiber tows are aligned in one direction without any interval is used.
And after taking up fiber base material (A1) 11a and fiber base material (A2) 11b with drive roll 14, and making a resin composition adhere to fiber base material (A1) 11a by application means 12, this fiber base material (A1) The fiber base material (A2) 11b is placed on the side of the resin composition 11a to which the resin composition is adhered, and the resin composition is sandwiched between them, and conveyed while being sandwiched between the endless metal belts 15a and 15b.
Subsequently, the impregnating means 13 warms the impregnating rolls 13a and 13b, and adjusts the viscosity of the resin composition sandwiched between the fiber base (A1) 11a and the fiber base (A2) 11b, while the resin composition is added to the fiber. The substrate (A1) 11a and the fiber substrate (A2) 11b are impregnated. Further, the protective films 16a and 16b are fed out from the feeding means 16, and the impregnated fiber base (A1) 11a and fiber base (A2) 11b are sandwiched between the protective films 16a and 16b. Winding is performed by the winding means 18.

Further, an example of a method for producing a prepreg by sandwiching the resin composition using the method 2 will be specifically described with reference to FIG.
The prepreg manufacturing apparatus 20 shown in FIG. 2 (a) includes a coating means 22 for attaching a resin composition to a fiber base material 21, a bending means 29 for bending the fiber base material 21 to which the resin composition is attached, and a fiber base material. Two sets of impregnation means 23 for impregnating the fiber base material 21 with the resin composition adhering to 21, a drive roll 24, a transport means 25 for transporting the fiber base material 21, a feeding means 26 for feeding out the protective film, A roll-shaped winding means 28 for winding the obtained prepreg 27 is provided.
The coating means 22 includes a resin bath (not shown) for storing a resin composition, and a die 22a for coating the fiber composition with the resin composition supplied from the resin bath.
The impregnation means 23 includes a pair of impregnating rolls 23a and 23b that can be heated.
The conveying means 25 includes a pair of endless metal belts 25a and 25b.
The bending means 29 includes a bending guide 29a that bends the fiber base material with the resin composition adhering side facing inward, and a bending nip 29b that presses the folded fiber base material.

Using the prepreg manufacturing apparatus 20 shown in FIG. 2 (a), first, the resin composition is stored in a resin bath of the coating means 22, and the resin temperature in the resin bath is maintained. Further, as the fiber base material, a sheet-like fiber base material in which carbon fiber tows are aligned in one direction without any interval is used.
And the fiber base material 21 is taken up with the drive roll 24, and the resin composition is made to adhere to the fiber base material 21 with the coating means 22. FIG.
Thereafter, as shown in FIG. 2 (b), the fiber base 21 is folded in half so that the side to which the resin composition is adhered is passed through a folding guide 29a of the bending means 29, and further a folding nip 29b To hold the resin composition. The fiber base material 21 bent in half is gently twisted by 90 ° to change the direction from the vertical direction to the horizontal direction, and then conveyed while being sandwiched between endless metal belts 25a and 25b as shown in FIG. .
Subsequently, the impregnating means 23 heats the impregnating rolls 23a and 23b, and the bent fiber base material 21 is impregnated with the resin composition while adjusting the viscosity of the resin composition sandwiched between the fiber base materials. Further, the protective films 26 a and 26 b are fed out from the feeding means 26, the impregnated fiber base material 21 is sandwiched between the protective films 26 a and 26 b, and the obtained prepreg 27 is wound up by the winding means 28.

  As described above, according to the present invention, the fiber base material can be sufficiently impregnated with resin so as not to be excessive, so that a prepreg having a drape property can be manufactured even when there is a thickness. Moreover, since it is not necessary to produce a resin film in a separate process unlike the hot melt film method, the processing cost and material cost of the process are not required, and the prepreg can be manufactured at a low cost.

If the prepreg obtained by the present invention is used, a high-strength fiber-reinforced composite material with few defects can be produced.
In particular, when a thick prepreg is used, the number of laminations can be reduced when producing a fiber-reinforced composite material. Moreover, since the prepreg obtained by the present invention has a drape property, the handleability is good and the lamination time can be shortened.
Therefore, the present invention is particularly suitable for producing a thick fiber-reinforced composite material.

10, 20: Prepreg manufacturing apparatus 11a: Fiber substrate (A1)
11b: Fiber substrate (A2)
21: Fiber base material 12, 22: Adhering means 12a, 22a: Die 13, 23: Impregnation means 13a, 13b, 23a, 23b: Impregnation roll 14, 24: Drive roll 15, 25: Conveyance means 15a, 15b, 25a, 25b: Endless metal belt 16, 26: Feeding means 16a, 16b, 26a, 26b: Protective film 17, 27: Pre-preg 18, 28: Winding means 29: Bending means 29a: Bending guide 29b: Bending nip

Claims (4)

  A method for producing a prepreg, wherein a liquid resin composition is sandwiched between fiber substrates made of continuous fibers, and the fiber substrate is impregnated with the resin composition.   The sandwiching of the resin composition is performed after the resin composition is attached to the first fiber base material (A1) made of continuous fibers and then continuously on the side of the first fiber base material (A1) to which the resin composition is attached. The manufacturing method of the prepreg of Claim 1 made | formed by overlapping the 2nd fiber base material (A2) which consists of fibers.   2. The prepreg according to claim 1, wherein the sandwiching of the resin composition is performed by attaching the resin composition to a fiber substrate made of continuous fibers and then bending the resin composition-attached side inward. Production method.   The manufacturing method of the prepreg as described in any one of Claims 1-3 with which the said resin composition contains an epoxy resin.

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