JPH03149230A - Production of prepreg - Google Patents

Abstract

PURPOSE:To produce in good efficiency a prepreg on which a matrix resin is laminated in multiple stage, by making a primary prepreg by superposing a release sheet carrying a resin on each surface of a sheeted reinforcing fiber and effecting the transfer of the resin to the reinforcing fiber and the infiltration of the resin into the fiber, releasing the release sheet from the primary prepreg and repeating this procedure. CONSTITUTION:A release sheet 14 (of a thickness of about 0.05-0.02mm) carrying a resin 16 (a thermosetting resin such as an epoxy resin or a thermoplastic resin such as a polyimide) is superposed on each surface of a sheeted reinforcing fiber 12 and the assemblage is pressed under heating with press rolls to effect the transfer of the resin 12 to the reinforcing fiber 12 and the infiltration of the resin 16 into the fiber 12, thus forming a primary prepreg 18. After the release sheet 15 is released from the primary prepreg 18, a release sheet 24 or 25 carrying a resin 26 formed by dispersing polyamide particles 28 in a resin component 27 which is desirably the same as the one used in the primary prepreg is superposed on the naked surface and pressed under heating with press rolls to transfer the resin to the primary prepreg 18. In this way, a secondary prepreg is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing sheet prepreg used for fiber-reinforced composite materials such as fiber-reinforced plastic. The present invention relates to a method for manufacturing prepregs using a series of continuous processes.

[Prior Art] Sheet-like prepregs used for molding fiber-reinforced composite materials usually consist of two sheets, at least one of which carries a resin (for example, a B-stage thermosetting resin), as shown in FIG. The reinforcing fibers 2 arranged in a sheet form are sandwiched between the release sheets 1 and 3, and the reinforcing fibers 2 are pressed with a press roll 4, for example.
A method of heating and transferring and impregnating the reinforcing fibers with resin to create a prepreg 5, peeling off one release seed 3 and winding the prepreg 5 together with the other release sheet 1 into a roll, or reinforcing. It is manufactured by a method in which the fibers are immersed together with a support sheet in a resin solution diluted with an appropriate solvent, pulled up, and heated to remove the solvent. When the prepreg manufactured by such a method is used, a release sheet is peeled off from one side thereof, a plurality of prepregs are laminated in the same direction or in different directions as necessary, and the prepreg is used to form a fiber-reinforced composite material.

In contrast to the conventional general prepreg manufactured by the method described above, the present applicant has recently developed a primary prepreg in which reinforcing fibers made of long fibers are transferred and impregnated with a base resin, and the base resin is applied to both or one side of the primary prepreg. A secondary prepreg has been developed that is made by transferring or appropriately impregnating a mixture of resin and fine particles made from other resins (
(Japanese Unexamined Patent Publication No. 64-26651, etc.). According to this prepreg, when made into a fiber-reinforced composite material while ensuring the excellent adhesiveness and flexibility of the prepreg, it can exhibit high strength in directions other than the fiber axis of the reinforcing fibers, especially between the laminated prepreg layers. By improving the strength and interlaminar toughness, it is possible to significantly improve the impact resistance, etc. of the composite material.

However, when manufacturing this prepreg by the conventional method shown in FIG. Alternatively, it is necessary to peel the release sheet from the primary prepreg while unwinding the roll and laminate the matrix resin on both sides of the primary prepreg. Therefore, manufacturing is labor-intensive and production efficiency is not good, and since the primary prepreg is unwound once it has been rolled up, a large amount of loss occurs until the resin lamination is stabilized at the start of secondary prepreg manufacturing, making it difficult to improve production yield. There was a problem that.

[Problems to be solved by the invention] In order to solve the above-mentioned problems, the present invention aims to improve production efficiency and yield in the production of prepregs having the excellent properties previously proposed by the applicant. The aim is to significantly increase production capacity.

[Means for Solving the Problems] The prepreg manufacturing method of the present invention in accordance with this objective comprises applying a release sheet on each side of reinforcing fibers arranged in a sheet shape, in which at least one side carries a resin. Overlap each,
The reinforcing fibers are transferred and impregnated with the resin to create a primary prepreg, and then at least one of the release sheets is peeled off from the primary prepreg, and the resin is supported all over the release sheet peeled surface of the primary prepreg. This method consists of stacking release sheets of different types and transferring the resin to the primary prepreg to create a secondary prepreg.

The reinforcing fiber in the present invention is a reinforcing fiber consisting of long fibers (
fiber bundles), carbon fibers, graphite fibers, organic high modulus fibers (
For example, aramid fiber, etc.), silicon carbide fiber, alumina fiber, boron fiber, tungsten carbide fiber, glass SIIM, etc. with high strength and high elastic modulus I! It is true. Such reinforcement III may be of only one type for the same prepreg or of different types of reinforcement 11i1.
i may be used in a regular or irregular arrangement.

These reinforcing fibers are arranged in a sheet shape. Normally, unidirectional prepreg is most suitable for applications that require high specific strength and specific modulus in a specific direction, but prepregs that are pre-processed into sheet forms such as long fiber mats and woven fabrics can also be used. is also possible.

A release sheet, in which at least one side (the surface facing the reinforcing fibers) carries a resin, is superimposed on each surface of the reinforcing fibers. The release sheet has a thickness of, for example, 0.05 to 0.2 for both primary prepreg production and secondary prepreg production.
A coating layer of a filler such as clay, starch, polyethylene, polyvinyl alcohol, etc. is applied to both sides of paper such as #lI11 kraft paper, roll paper, glassine paper, etc., and a silicone-based sealant is applied on each coating layer. or a non-silicone mold release agent, preferably a condensation reaction type of polydimethylsiloxane and polydimethylhydrodienesiloxane;
It is like applying a mold release agent made of addition reaction type silicone. A synthetic resin film imparted with mold releasability by corona discharge treatment or the like or a synthetic resin film coated with a mold release agent can also be used (for example, polyethylene film, polypropylene film, etc.). By using a synthetic resin film, there is less dimensional change due to moisture absorption compared to stamp paper. (2) The flexibility of the carrier is improved, allowing the product to be wound around a small diameter winding core. When unwinding and cutting the prepreg rolled up together with the sheet into a certain shape, paper dust tends to come out when using paper, which can adhere to the prepreg and cause defects in the molded product, but when using resin film, cutting is difficult. Effects such as less generation of powder can be obtained.

Transferred to reinforcing fibers on at least one side of this release sheet,
A base resin is supported as a matrix resin to be impregnated. Examples of the base resin include thermosetting resins and resins that are a mixture of thermosetting resins and thermoplastic resins.

The thermosetting resin used in the present invention includes epoxy resin,
Examples include maleimide resin, polyimide resin, resin having an acetylene end, resin having a vinyl end, resin having an allyl end, resin having a nadic acid end, and resin having a cyanate ester end. These can generally be used in combination with a curing agent or a curing catalyst. Also,
It is also possible to use a mixture of these thermosetting resins as appropriate.

Epoxy resin is used as a thermosetting resin suitable for the present invention. Particularly preferred are epoxy resins whose precursors are amines, phenols, and compounds having carbon-carbon double bonds. Specifically, as an epoxy resin using amines as a precursor, various isomers of tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl 1-amine phenol, triglycidylaminofresol, and phenols are used as precursors. Examples of epoxy resins used as precursors include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenol novolak epoxy resin, Talesol novolak epoxy resin, and compounds having carbon-carbon double bonds. Examples of the epoxy resin include, but are not limited to, alicyclic epoxy resins.

Brominated epoxy resins obtained by brominating these epoxy resins may also be used. Epoxy resins whose precursors are aromatic amines such as tetraglycidyldiaminodiphenylmethane are most suitable for the present invention because they have good heat resistance and good adhesion to reinforcing fibers.

Epoxy resins are preferably used in combination with epoxy curing agents. Any compound having an active group capable of reacting with an epoxy group can be used as the epoxy curing agent. Preferably, compounds having an amine group, an acid anhydride group, or an azide group are suitable. Specifically, dicyandiamide, various isomers of diaminodiphenylsulfone, and aminobenzoic acid esters are suitable. To explain specifically,
Dicyandiamide is preferably used because it has excellent pre-preg stability. Further, various isomers of diaminodiphenylsulfone are most suitable for the present invention because they give cured products with good heat resistance. As aminobenzoic acid esters, trimethylene glycol di-p-fuminobenzoate and neopentyl glycol di-p-aminobenzoate are preferably used, and although they have inferior heat resistance compared to diaminodiphenylsulfone, they have excellent tensile strength. For,
It is selected and used depending on the purpose.

In the present invention, it is also suitable to use a mixture of the above thermosetting resin and a thermoplastic resin as the matrix resin. Thermoplastic resins suitable for the present invention include carbon-carbon bonds, amide bonds, imide bonds, ester bonds, ether bonds, carbonate bonds, urethane bonds, urea bonds, thioether bonds, sulfone bonds, imidazole bonds, and carbonyl bonds in the main chain. A thermoplastic resin having a bond selected from bonds, more preferably polyacrylate, polyamide, polyaramid, polyester), polycarbonate, polyphenylene sulfide, polybenzimidazole, polyimide, polyetherimide, polysulfone, polyethersulfone, A group of thermoplastic resins belonging to engineering plastics such as polyetheretherketones. In particular, polyimide, polyetherimide, polysulfone, polyether sulfone, and polyether ether ketone are optimal for the present invention because they have excellent heat resistance.

As these thermoplastic resins, commercially available polymers may be used, or so-called oligomers having a lower molecular weight than commercially available polymers may be used. As the oligomer, an oligomer having a functional group capable of reacting with the thermosetting resin at the terminal or in the molecular chain is more preferable.

Thus, mixtures of thermosetting resins and thermoplastic resins give better results than when thermosetting resins are used alone. This is because thermosetting resins generally have the disadvantage of being brittle but can be molded at low pressure in an autoclave, whereas thermoplastic resins have the advantage of being tough but are difficult to mold at low pressure in an autoclave. This is because they exhibit contradictory properties, so by mixing and using these, it is possible to achieve a balance between physical properties and moldability. The amount of thermoplastic resin relative to 100 parts by weight of matrix resin is preferably up to 50% by weight, more preferably up to 30% by weight.

A primary prepreg is created by transferring and impregnating reinforcing fibers with the base resin as described above. 'For transfer and impregnation,
Usually, a method is adopted in which a stacked body in which reinforcing fibers are sandwiched between two mold releasing sheets is heated and pressurized with a press roll.

The press rolls are preferably arranged in an appropriate number of stages in order to perform transfer and impregnation more completely and more uniformly.

In addition, in order to assist and promote heating, before the press roll,
A heater may be provided between each press roll.

At the step immediately after the resin transfer and impregnation, release sheets are laminated on both sides of the primary prepreg (there is a state in which release sheets are laminated on both sides of the primary prepreg, but subsequently, at least one release sheet is peeled off from the created primary prepreg. When both mold sheets are peeled off, the primary prepreg becomes a single body. At this time, it is preferable that both mold release sheets are peeled off at substantially the same time since the entire apparatus can be peeled off in a short period of time. It may be peeled off sequentially at the front and rear positions in the feeding direction.

Next, a release sheet carrying resin on one surface is superimposed on the release sheet release surface of the primary prepreg. When attaching the release sheet to both sides of the primary prepreg, it is preferable to do it substantially simultaneously for the same reason as above, but it may be done before or after in the prepreg feeding direction. It is important to prevent the primary prepreg from touching other members such as guide rolls until the resin-supported release sheet is superimposed on the primary prepreg.

The resin supported on the release sheet for making the secondary prepreg is basically a resin that is not the same as the resin for the primary prepreg. Here, "non-identical resin" refers to a resin that contains the same resin components as the resin for making the primary prepreg, but also contains other resin components, and "a resin" refers to a resin that is different from the resin for making the primary prepreg. . As a resin for making a secondary prepreg, which contains the same nine resin components as the base resin for making the primary prepreg and other resin components, the base resin may contain either a thermoplastic resin or a thermosetting resin, or a thermosetting resin. It is preferable to use a mixture of fine particles as a raw material. Since fine particles exist in a dispersed state in the base resin when mixed with the base resin, the characteristics of the base resin appear to be dominant in the matrix resin, and even when impregnated into reinforcing fibers, the properties of the base resin are A prepreg that maintains adhesiveness and deformability (drapeability) and has excellent handling properties can be obtained. Therefore, since adhesiveness and deformability (drapeability) are not required as characteristics of the fine particles, there is a wide range of materials that can be selected for the fine particles.

For this reason, even resins that were conventionally difficult to use as matrix resins despite their superior performance can be made into fine particles and used as constituents of matrix resins, improving the performance of matrix resins. can do.

Thermosetting resins used as fine particles include epoxy resins, phenolic resins, unsaturated polyester resins, amino resins, allyl resins, silicone resins, urethane resins, maleimide resins, polyimide resins, resins with acetylene ends, and resins with vinyl ends. , a resin having an allyl end, a resin having a nadic acid end, and a resin having a cyanate ester end. Examples of commercially available thermosetting resin fine particles include Toshi special epoxy resin "To, Repal" EP-8, and phenolic resin Bell Pearl "R-800" manufactured by Kanekoji@.

Furthermore, even if fine particles cannot be obtained as a commercial product, it is possible to make them into fine particles by crushing the above-mentioned resin, and by further classification, it is possible to use only particles within the desired particle size range. Can be done.

It is also suitable for the present invention to use a thermoplastic resin as the fine particles. Thermoplastic resins suitable for the present invention include carbon-carbon bonds, amide bonds, imide bonds, ester bonds, ether bonds, carbonate bonds, urethane bonds,
The thermoplastic resin has a bond selected from a urea bond, a thioether bond, a sulfone bond, an imidazole bond, and a carbonyl bond, but it may also have a partially crosslinked structure within the molecule. Specifically, vinyl resins represented by polyacrylate, polyvinyl acetate, and polystyrene, polyamide, polyaramid, polyether, polyacetal, polycarbonate, polyphenylene oxide, polyphenylene sulfide, polyarylate, polybenzimidazole, polyimide, Thermoplastic resins belonging to engineering plastics such as polyamide-imide, polyetherimide, polysulfone, polyether sulfone, and polyether ether ketone, hydrocarbon resins such as polyethylene and polypropylene, cellulose acetate, and cellulose acetate. Examples include cellulose derivatives.

In particular, polyamide, polycarbonate, polyacetal, polyphenylene oxide, polyphenylene sulfide, polyarylate, polyester, polyamideimide,
Polyimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone, polyaramid, and polybenzimidazole have excellent impact resistance and are therefore suitable as materials for the fine particles used in the present invention.

Among these, polyamide has particularly excellent toughness, and by using a polyamide that belongs to the amorphous transparent nylon category, it can also have heat resistance. Commercially available thermoplastic resin fine particles include, for example, nylon 12 fine particles sp-soo manufactured by Toshiki Co., Ltd. and acrylic fine particles M p-1000 manufactured by Japan Synthetic Rubber Il. Furthermore, even if fine particles cannot be obtained as a commercial product, it is possible to make them into fine particles by crushing the above-mentioned resin, and by further classification, it is possible to use only particles within the desired particle size range. Can be done.

It is also suitable to use a mixture of a thermosetting resin and a thermoplastic resin as the fine particles. Suitable thermosetting resins and thermoplastic resins in this case are the same as those described above. For example, if a mixture of phenolic resin and nylon resin is used, the water absorption rate of the nylon resin will be lowered and the glass point transition temperature will be increased while maintaining the toughness of the nylon resin, resulting in a particle component with excellent heat and water resistance. can.

Regarding the distribution of the fine particles, it is preferable that the fine particles exist biased toward the surface layer of the secondary prepreg.

In highly anisotropic materials such as composite materials, stress is rarely uniform throughout the material, and in most cases, stress is concentrated in specific areas. In particular, in the case of fiber-reinforced composite materials obtained by laminating sheet-like prepregs, it is known that large stress is applied between the layers when an external force such as an external impact force is applied. Therefore, when fine particles with excellent toughness are distributed at a relatively high concentration between the layers, a remarkable effect is brought about in improving the interlayer toughness. In other words, near the surface layer of the secondary prepreg obtained, the matrix resin becomes a hybrid type of base resin and fine particle component, and the base resin component provides favorable adhesion and drape properties, while the fine particle component provides high interlaminar toughness, strength, etc. They can be demonstrated together. The amount of such fine particles is suitably in the range of 0.1% to 80% by weight based on the matrix resin.

If it is less than 0.1% by weight, the effect of fine particles will hardly appear,
Moreover, if it exceeds 80% by weight, it becomes difficult to mix with the base resin, and the adhesiveness as a matrix resin also decreases significantly.

The resin for making the secondary prepreg can also be the same as that for making the primary prepreg. First, when obtaining a thick secondary prepreg, by using the same resin for making the primary and secondary prepregs, the resin distribution in the secondary prepreg can be made more uniform. This is because the amount of resin to be impregnated at one time can be distributed appropriately, and it becomes possible to prevent uneven spread of the resin during pressurized impregnation.

A release sheet carrying a resin for producing the secondary prepreg as described above is laminated on the primary prepreg, and the resin is transferred to the primary prepreg. In this transition, if the above-mentioned resin is impregnated too strongly, the desired properties of the above-mentioned fat for forming the surface layer side of the secondary prepreg may be impaired, so impregnation should be appropriately controlled. preferred. For the transfer and impregnation, a method of heating and pressurizing the stacked body of the primary prepreg and the release sheet with a press roll can be applied, as in the case of producing the primary prepreg. The degree of impregnation can be controlled by the heating and pressurizing conditions. The arrangement of multiple stages of press rolls and the arrangement of heaters in front of the press rolls and/or between the press rolls may be appropriately adopted as in the case of producing the primary prepreg.

One of the mold release sheets is peeled off from the created secondary prepreg, and the secondary prepreg is wound up together with the other mold release sheet. In other words, the same method as the conventional method shown in FIG. 5 can be adopted. However, although the present invention specifies up to the creation of secondary prepreg, it is also possible to create tertiary prepreg and even multi-dimensional prepreg by continuing to perform the same process as secondary prepreg creation after creating secondary prepreg. It is.

As described above, according to the prepreg manufacturing method of the present invention,
The process from supplying reinforcing fibers arranged in a sheet shape to creating secondary prepreg is carried out in a series of continuous processes.

[Examples] Hereinafter, preferred embodiments of the present invention will be shown, and the present invention will be described in more detail with reference to the drawings.

FIG. 1 shows the entire prepreg manufacturing apparatus for carrying out the prepreg manufacturing method according to an embodiment of the present invention, and FIGS. 2 and 3 show the state during the production of primary prepreg and secondary prepreg. FIG. 4 shows coaters for preparing in advance a release sheet carrying resin.

In FIG. 1, in this embodiment, reinforcing fibers 12 (fiber bundles) (e.g. carbon fibers) drawn from a large number of creels 11 are drawn parallel to each other in one direction and into a sheet shape via a nip roll 13 or the like. .

The reinforcing fibers 12 arranged in a sheet shape are sent to the primary prepreg production process in the direction of the arrow. Release sheets 14 and 15 made of release paper are superimposed on both the upper and lower surfaces of the reinforcing fibers II 12, but in this example, as shown in FIG. 12
A resin 16 (for example, a B-stage epoxy resin) for making the primary prepreg is carried on the side surface.

A superimposed body of reinforcing fibers 12 and resin-supported release sheets 14 and 15 is a three-stage press roll 1 consisting of nip rolls.
7, the supported resin 16 is transferred to and impregnated into the reinforcing fibers 12, and a primary prepreg 18 is formed as a single unit. If necessary, the primary prepreg 18 may be further heated by a heater 19 (for example, a far-infrared heater) between the pre-support rolls 17, or conversely, in some cases, no heating is performed at all, and the primary prepreg 18 is heated only by pressurization by the press rolls 17. It is also possible to create one.

The upper and lower resin-supported mold release sheets 14 and 15 are unwound from the respective mold release geat rolls 20 and 21, and in this example, they are layered on both sides of the reinforcing fibers 12 substantially simultaneously, and after the primary prepreg 18 is created, They are peeled off from the primary prepreg 18 at substantially the same time. Simultaneous peeling minimizes the required length of the device in the sheet feeding direction.

The release sheet 14.15 that was peeled off and became only the release paper,
It is collected in rolls 22 and 23 and reused as long as there is no damage. The primary prepreg 18 from which both release sheets 14 and 15 have been peeled off is sent as a heavy body to the subsequent secondary prepreg production process.

In the secondary prepreg production step, resin-supported release sheets 24 and 25 are superimposed on both surfaces of the primary prepreg 18 at the same time in this embodiment. In this example, the third
As shown in the figure, a predetermined resin 26 is supported on both release sheets 24 and 25, but it is also possible to have resin 26 supported on only one side and transfer the resin only from one side of the primary prepreg 18. It is.

The resin 26 is made of, for example, a mixed resin of a portion 27 of the same type of resin (e.g., epoxy resin) as the base resin 16 of the primary prepreg 18 and fine particles 28 . Both release sheets 24
．． 25 and the primary prepreg 18 is heated and pressurized by three stages of press rolls 29 in the same manner as the primary prepreg W forming process, and the supported resin 26 is transferred to the primary prepreg 18, and may be impregnated to some extent in some cases. Then, a secondary prepreg 30 is created.

Release sheet 24.25 for making this secondary prepreg 30
When the resin supported on the resin is a mixture of resin-based fine particles 28 and other resin components 27, it is possible to distribute the fine particles 28 near the surface layer of the polar prepreg 30, as described above. This is preferable in order to obtain the desired performance of the secondary prepreg 30 (improvement of interlaminar strength and interlaminar toughness when made into a composite material while maintaining adhesion and flexibility). Therefore, it is desirable not to apply too much heat or pressure at the press roll 29 to prevent the fine particles 28 from sinking into the prepreg too much. In other words, by controlling the degree of heating and pressurization, it is possible to control the distribution of fine particles 28 in the thickness direction of the prepreg. Conditions (including conditions) are adjusted.

The resin-supported release sheet 24.25 is attached to each roll 31.32.
The upper release sheet 24 is unrolled and laminated substantially simultaneously on both sides of the primary prepreg 18 , and after the secondary prepreg 30 is created, only the upper release sheet 24 is peeled off as a single unit and wound up into a roll 33 . The lower release sheet 25 is wound up on the winding shaft 34 together with the created secondary prepreg 30. 635 makes it possible to temporarily stop only the winding end when changing the winding shaft in continuous production. The figure shows an accumulator (a device that changes the sheet path length by vertically displacing the roll and temporarily stores continuously supplied sheets).

When producing the above prepreg, the resin-supported release sheet for producing the second prepreg and the second prepreg should be
For example, as shown in FIG. 4, it is prepared in advance by a bath roll type coater 4G.

The release sheet 4 is released from the roll 42 set on the unwinding machine 41.
3 is unwound, and one surface of the release sheet 43 is coated with a coating molten resin 46 that is continuously supplied onto a coating roll 44 via an applicator roll 45. Whether or not a predetermined coating thickness has been achieved can be determined by checking the release sheet 43 using, for example, a β-line grating meter 47.
The thicknesses of the single piece and the resin-coated release sheet 60 are checked by measuring the thickness, and the resin-supported release sheet 6G is wound onto a roll 48. This roll 48 is subjected to the above-mentioned primary prepreg and secondary prepreg production process.

The coating resin 46 is produced by melting a resin block 49 with a heating roll 50 as a melt and guiding (dropping) the molten resin onto the applicator roll 45 to reduce the clearance between the applicator roll 45 and the metal ring roll 51. The amount of molten resin supplied is controlled by adjusting the circumferential speed, temperature, etc. of both rolls, and the molten resin is transferred from the applicator roll 45 onto the release sheet 43, thereby being supplied and coated. Heating 0-50, applicator roll 4
5. The metering roll 51 and the coating roll 44 are equipped with internal heaters 52, 53, 54, 55, respectively.
Alternatively, heating is controlled by a heating medium.

In such resin coating on the release sheet 43, especially when the resin supported on the release sheet 43 is a resin for producing a secondary prepreg mixed with the resin fine particles described above, the following measures may be taken. , consideration is required.

First, the coating that forms the resin block 49
The resin is a mixture of fine particles made of resin and a base resin, and it is desirable that the fine particles are mixed uniformly. Fine particles have a particle diameter of, for example, several microns to several tens of micrometers, but after production, such fine particles
It tends to cause secondary aggregation before mixing with the base resin.

If the fine particles are mixed with the base resin while being aggregated, the aggregated state tends to remain in the mixed resin, causing problems when passing through the clearance between the applicator roll 45 and the metering roll 51 (uneven passage, Otherwise, the release sheet 43 may be coated with streak-like defects (uneven coating). Therefore, the fine particles need to be deagglomerated using a crusher before being mixed with the base resin before use. By crushing the fine particles in this manner, the fine particles having a target average particle diameter are uniformly mixed with the base resin, and in this state, they are melted and provided for coating.

In addition, in relation to the coatability (easiness of coating) of the above-mentioned fine particle mixed resin, the following considerations should be made in setting the eye weight of the resin for making the primary prepreg and the above fine particle mixed resin for making the secondary prepreg. is necessary.

The weight ratio of the reinforcing fibers and the matrix resin after the preparation of the secondary prepreg is determined, for example, by the use of the prepreg for molding a composite material, that is, by the user's request. For example, if the matrix resin for the entire secondary prepreg is set at 35% by weight and 100 g/m, then the resin for creating the primary prepreg and the resin for creating the secondary prepreg mixed with fine particles are, for example, 22% by weight and 13% by weight. is set to However, in order to improve the impregnating property of attu with the resin for strengthening in the process of making the primary prepreg, it is preferable that the amount of the resin for making the primary prepreg be a little larger. For example, 22 above
It is desirable to increase the resin proportion by weight to about 30% by weight. However, the total amount of matrix resin is 35
Since it is specified in weight%, if the amount of resin for making the primary prepreg is 30% by weight, the amount of resin for making the secondary prepreg must be reduced to 5% by weight. As mentioned above, the resin particles mixed in the resin for making the secondary prepreg have the function of greatly increasing the interlaminar strength and interlaminar toughness of the composite material i, but in order to obtain the desired effect, A certain amount or more is required. For example, if fine particles need to have a basis weight of at least 5 g/m'', if the proportion of the secondary prepreg-producing resin to the entire prepreg is 13% by weight as described above, then this 5 g/m''
The proportion of fine particles in the resin for making the secondary prepreg according to the basis weight of R'' is, for example, about 13.5% by weight, and when the proportion of the resin for making the secondary prepreg to the entire prepreg is 5% by weight as described above. , above 5g/Tri,”
The proportion of fine particles in the resin for preparing the secondary prepreg according to the basis weight can be increased to 35°O weight %.

However, there is a limit to the proportion (concentration) of fine particles in the resin for preparing the secondary prepreg from the viewpoint of coating properties on the release sheet. In other words, if the concentration becomes too high,
The overall viscosity of the resin for making secondary prepregs decreases,
Coating properties deteriorate due to lack of viscosity. Therefore, in order to ensure coating properties, it is desirable to keep the concentration of fine particles in the resin for making secondary prepregs below a certain level, and the absolute amount is Reducing the concentration of fine particles that is required above a certain level (for example, 5g/7m" above) to below a certain level means that there is a limit to reducing the proportion of secondary prepreg-producing resin to the entire prepreg. become.

That is, as mentioned above, if the amount of resin for primary prepreg production in the primary prepreg production process is increased, the reinforcement 111i
Although it is possible to improve the impregnating properties of the prepreg, there is a limit to the reduction in the amount of resin used to create the secondary prepreg, as described above, due to the coating properties of the release sheet. In order to achieve both ease of production and ease of production of the resin-supported release sheet for making the secondary prepreg, it is necessary to set the weight settings of the resin for the production of the primary prepreg and the resin for the production of the secondary prepreg to the optimum value or range, respectively. exists, and it is important to set a realistic basis weight in line with this.

In addition, in the prepreg manufacturing process shown in FIG. 1, it is preferable to take the following considerations.

In the manufacturing process shown in FIG.
4 (It is rolled up, but when this prepreg 3G is used for molding composite materials, such as fishing rods and golf shafts, or when shipped for these uses,
It is often used as a sheet cut into 80 to 180 art lengths. In such use, it is preferable that the type of prepreg be clearly recognized.

Release sheet 25 wound together with pulley preg 30
The width of the prepreg 3G is usually set larger than the width of the prepreg 3G, and there is only an edge of the release sheet 25. Conventionally, the type of prepreg was printed on this edge using a printing machine or magic ink to indicate the type of prepreg, but regular ink was extremely difficult to adhere to the release sheet (release paper).
It was quite difficult to perform desired printing. Therefore, in the above-mentioned example Kotoki, when thermal stamping was performed using a printer, it became possible to print reliably. For example, printing by this hot printer is 100 times.
If this is done automatically and continuously at intervals of as or less, even if the sheets are cut into lengths of 80 to 1801 J as described above, at least one out of every two sheets will always be printed, which means that there will be no need for post-processing or secondary printing. It becomes possible to clearly distinguish between varieties during the machining process.

[Effects of the Invention] As detailed above, when using the prepreg manufacturing method of the present invention, it is possible to manufacture a prepreg in which reinforcing fibers are transferred and impregnated with matrix resin in two stages through a series of continuous processes. This makes it possible to improve production efficiency and production yield, and significantly increase production capacity. In particular, reinforcing fibers are transferred and impregnated with a base resin to create a primary prepreg, and then a resin mixed with fine particles made of resin is transferred and impregnated to create a secondary prepreg.
It is possible to significantly improve the production capacity of prepregs, which can maintain the adhesion and flexibility of prepregs while improving the interlaminar strength and interlaminar toughness, which would otherwise be detrimental to composite materials.

[Brief explanation of the drawing]

FIG. 1 is a side view of the entire prepreg manufacturing apparatus for carrying out a method according to an embodiment of the present invention, and FIG. 2 is an enlarged vertical cross-section of a portion of the apparatus shown in FIG. 1 showing the state at the start of primary prepreg production. 3 is an enlarged partial vertical sectional view showing the state of the apparatus shown in FIG. 1 at the start of secondary prepreg production,
FIG. 4 is a side view of a CO-9 for creating a resin-supported release sheet used in prepreg production using the apparatus shown in FIG. 1, and FIG. 5 is a schematic side view of a conventional prepreg production apparatus. . 11... Creel 12... Reinforced fiber 14.15.24.25-- Release sheet 16-
...Resin for making primary prepreg 17.29...
...Press roll 18...Primary prepreg 19--Heater 20.21.31.32...Resin-supporting mold release gear
Troll 22.23.33...Release sheet single roll 2
6... Resin for making secondary prepreg 27...
... Resin component 28 ... Fine particles 30 ... Secondary prepreg 34 ... Winding shaft 40 ... Coater 41 ... Unwinding machine 43--Release sheet 44--Coating roll 45--Applique roll 46-- Molten resin for coating 41--
・Total weight: 49 Resin block

Claims (1)

[Claims] 1. Layer a release sheet on each side of reinforcing fibers arranged in a sheet shape, with at least one side carrying a resin, and transfer and impregnate the reinforcing fibers with the resin to create a primary prepreg. Then, after peeling off at least one of the release sheets from the primary prepreg, a release sheet carrying a resin on one surface is superimposed on the release sheet release surface of the primary prepreg, and the resin is applied to the primary prepreg. A method for manufacturing prepreg, which comprises creating a secondary prepreg by transferring.