JP2020029016A - Manufacturing method for prepreg, prepreg tape and fiber-reinforced composite material, and manufacturing device for prepreg - Google Patents

Abstract

To provide a manufacturing method and a manufacturing device for prepreg that can suppress generation of fuzz and continuously manufacture prepreg without clogging of fuzz and further can efficiently impregnate a reinforcement fiber sheet with matrix resin to increase manufacturing speed.SOLUTION: In a manufacturing method for a prepreg, a reinforcement fiber sheet having reinforcement fibers arranged in one direction is passed downward in a substantially vertical direction to inside a coating part storing matrix resin, and the matrix resin is applied to the reinforcement fiber sheet. The coating part comprises a liquid pool part and a narrowed part communicated with each other. The liquid pool part has a part at which a cross-sectional area continuously reduces along a running direction of the reinforcement fiber sheet. The narrowed part has a slit-like cross section and has a cross sectional area smaller than an upper surface of the liquid pool part. The reinforcement fiber sheet is made to run while contacting the sheet with a member provided at a position within 1 mm or more and 300 mm or less from liquid level of the matrix resin stored in the coating part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a prepreg, and more particularly to a method and an apparatus for uniformly impregnating a reinforcing fiber sheet with a matrix resin.

  Fiber reinforced composite material (FRP), which is a matrix resin containing thermoplastic resin and thermosetting resin reinforced with reinforcing fibers, is a material for aviation and space, automotive material, industrial material, pressure vessel, building material, housing, medical equipment. It is used in various fields such as applications and sports. Particularly when high mechanical properties and lightness are required, carbon fiber reinforced composite materials (CFRP) are widely and suitably used. On the other hand, when cost is prioritized over mechanical properties and light weight, a glass fiber reinforced composite material (GFRP) may be used. In the FRP, a reinforcing fiber bundle is impregnated with a matrix resin to obtain an intermediate substrate, which is laminated and molded, and when a thermosetting resin is used, is thermoset to produce a member made of FRP. In the above-mentioned applications, there are many planar objects and those obtained by bending the same, and the two-dimensional sheet-like material is more often used as an intermediate substrate of FRP than a one-dimensional strand or roving-like material when producing a member. It is widely used from the viewpoint of lamination efficiency and moldability.

  Recently, in order to improve the production efficiency of members made of FRP, mechanization and automation of lamination of sheet-like intermediate base materials have been promoted, and narrow tape-like intermediate base materials are preferably used here. The narrow tape-shaped intermediate substrate can be obtained by slicing a wide sheet-shaped intermediate substrate at a desired width, or by directly impregnating a narrow reinforcing fiber sheet with a matrix resin.

  As a two-dimensional sheet-like intermediate base material, a prepreg obtained by impregnating a matrix resin into a reinforcing fiber sheet in which reinforcing fibers are arranged in one direction is widely used. As the reinforcing fiber sheet used for the prepreg, there is a UD base material in which reinforcing fibers are arranged in one direction to form a sheet, and a reinforcing fiber fabric in which the reinforcing fibers are arranged in multiple directions. Particularly when the mechanical properties are prioritized, the UD base material is often used.

  Hot-melt method, one of the prepreg manufacturing methods, is to melt the matrix resin, coat it on release paper, create a laminated structure sandwiched between the upper and lower surfaces of the reinforcing fiber sheet, and apply heat and pressure. The matrix resin is impregnated inside the reinforcing fiber sheet. This method has a problem that the number of steps is large, the production speed cannot be increased, and the cost is high.

  For improving the efficiency of impregnation, for example, there has been a proposal as in Patent Document 1. In this method, a glass fiber is melt-spun and then bundled into a strand or roving to pass through a liquid reservoir having a conical flow path filled with a thermoplastic resin.

  On the other hand, a method for simultaneously forming a coating film on both sides of a sheet material is described in Patent Document 2. However, in order to prevent the fluctuation of the sheet material at the time of forming the coating film, the sheet material is passed through a web guide. After that, coating is performed with a pipe type doctor.

  As a method for producing a strip-shaped prepreg using a thermoplastic resin, a strip-type reinforcing fiber bundle is conveyed in a horizontal direction (horizontal direction), passed through a die, and a thermoplastic resin is applied to and impregnated into the strip-shaped reinforcing fiber bundle. Patent Literature 3, Patent Literature 4, etc.) are known. In Patent Document 3, a tape-like reinforcing fiber is passed through a crosshead (FIG. 2 of Patent Document 3), and a resin is applied to a tape-like reinforcing fiber bundle immediately before a linear die portion in the crosshead. Patent Document 4 discloses that a plurality of band-shaped reinforcing fiber bundles are separately introduced into a die filled with a molten thermoplastic resin, opened, impregnated, and laminated by a fixed guide (for example, a squeeze bar). It is described that the sheet-shaped prepreg is pulled out from a die.

International Publication WO2001 / 028551 pamphlet Patent No. 3252278 JP-A-6-31821 International Publication WO2012 / 002417 Pamphlet

  However, the method of Patent Document 1 can produce only a strand or a roving-like material, and cannot be applied to the production of a sheet-like prepreg to which the present invention is applied. Further, in Patent Literature 1, in order to improve the impregnation efficiency, a fluid of a thermoplastic resin is applied to the strand or the side surface of the roving-like reinforcing fiber bundle to generate turbulent flow positively in the conical flow path. It is considered that this is intended to partially disturb the arrangement of the reinforcing fiber bundles and allow the matrix resin to flow in.However, when this idea is applied to the unidirectional array reinforcing fiber bundles, the arrangement of the reinforcing fiber bundles is disturbed, It is considered that not only the quality of the prepreg decreases, but also the mechanical properties of the FRP decrease.

  Further, the sheet-like material in Patent Document 2 is a film, cloth, paper, foil, a punching plate, a net-like sheet material, and the like, and the reinforcing fiber sheet which is the object of the present invention is not intended. If the technique of Patent Literature 2 is applied to a reinforcing fiber sheet made of carbon fibers, it is considered that fluff is generated by rubbing with a web guide, and the running of the reinforcing fiber sheet becomes difficult. Further, the technique of Patent Document 2 is coating of a resin, and impregnation is not intended.

  In the technique of Patent Document 3, since the tape-like reinforcing fiber passes through the slit-shaped guider chip without resin at the front portion of the die portion in the crosshead, the fluff is easily clogged, and there is no function of removing the fluff. Therefore, it is considered difficult to continuously run for a long time. In particular, it is considered that this tendency is remarkable in carbon fibers in which fluff is easily generated.

  Further, in the method of Patent Document 4, fluff is likely to stay in the liquid pool portion during continuous production, and fluff is likely to be clogged in the withdrawn portion. In particular, when the band-shaped reinforcing fiber bundle is continuously run at a high speed, the frequency of clogging of the fluff is extremely increased, so that production can be performed only at a very low speed, and there is a problem that productivity is not improved. Further, in the case of the horizontal drawing method, it is necessary to seal the die portion to prevent liquid leakage, and it is not sufficient to collect fluff during continuous production. Furthermore, in the horizontal drawing method, when the matrix resin is impregnated inside the reinforcing fiber sheet, the air bubbles remaining inside the band-shaped reinforcing fiber bundle are buoyant to a direction orthogonal to the orientation direction of the reinforcing fiber bundle (band-shaped reinforcing fiber). Since the gas is discharged in the direction of the thickness of the fiber bundle (the thickness direction of the fiber bundle), the discharge of the bubbles proceeds as if the impregnated matrix resin is pushed away. Therefore, there is a problem that impregnation efficiency is poor because the movement of bubbles is inhibited by the liquid and the impregnation of the matrix resin is also inhibited by the bubbles. In addition, although patent document 4 proposes exhausting air bubbles from a vent, the effect is considered to be limited only in the vicinity of the die outlet.

  As described above, an efficient method of applying a matrix resin to a reinforcing fiber sheet such as a UD base material or a reinforcing fiber fabric, particularly an efficient manufacturing method of a sheet prepreg using a UD base material, has not yet been established.

  An object of the present invention is to reduce the generation of fluff in the prepreg production method, to enable continuous production without clogging of fluff, and to impregnate the reinforcing fiber sheet with a matrix resin efficiently, thereby increasing the production speed. It is an object of the present invention to provide a prepreg manufacturing method and a manufacturing apparatus that are possible.

  The method for producing a prepreg of the present invention that solves the above-mentioned problem is that a reinforcing fiber sheet in which reinforcing fibers are arranged in one direction is passed substantially downward in a vertical direction inside an application portion in which a matrix resin is stored. A method for producing a prepreg for applying a matrix resin to a reinforcing fiber sheet, wherein the application section includes a liquid reservoir and a constriction that are communicated with each other, and the liquid reservoir has a cross-sectional area along a running direction of the reinforcing fiber sheet. Has a portion that continuously decreases, the constricted portion has a slit-shaped cross section, and has a cross-sectional area smaller than the upper surface of the liquid reservoir portion, and is 1 mm from the liquid level of the matrix resin stored in the application portion. It is characterized in that the reinforcing fiber sheet is made to travel while being in contact with a member provided at a position within 300 mm or more.

  Further, a method of manufacturing a prepreg tape according to the present invention is characterized in that the prepreg obtained by the above-described method of manufacturing a prepreg is slit.

  Further, the method for producing a fiber-reinforced composite material of the present invention is characterized in that the prepreg obtained by the above-described method for producing a prepreg or the prepreg tape obtained by the above-described method for producing a prepreg tape is cured.

  Further, the prepreg manufacturing apparatus of the present invention is a prepreg manufacturing apparatus having a traveling mechanism for running the reinforcing fiber sheet substantially vertically downward, and a coating mechanism for applying a matrix resin to the reinforcing fiber sheet to obtain a prepreg. The coating mechanism is capable of storing a matrix resin therein, and further includes a liquid reservoir and a constriction which are communicated with each other, and the liquid reservoir is cut along the running direction of the sheet-like reinforcing fiber bundle. The constricted portion has a slit-shaped cross section, and has a cross-sectional area smaller than the upper surface of the liquid reservoir portion, and the liquid surface of the matrix resin stored in the application portion has an area having a continuously decreasing area. A member that comes into contact with the reinforcing fiber sheet at a position within 1 mm or more and 300 mm or less.

  By using the prepreg manufacturing method of the present invention or the prepreg manufacturing apparatus of the present invention, clogging due to fluff can be significantly suppressed and prevented. Further, the reinforcing fiber sheet can be run continuously and at a high speed, and the productivity of the reinforcing fiber sheet provided with the matrix resin is improved, and the reinforcing fiber sheet uniformly impregnated with the matrix resin can be obtained.

1 is a schematic cross-sectional view showing a prepreg manufacturing method and a prepreg manufacturing apparatus according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a prepreg manufacturing method and a prepreg manufacturing apparatus according to an embodiment of the present invention, which is different from FIG. 1. FIG. 2 is an enlarged detailed cross-sectional view of a coating section 20 in FIG. 1. FIG. 3 is an enlarged detailed cross-sectional view of the vicinity of a member 18 in FIG. 2. FIG. 3 is a bottom view of the application unit 20 in FIG. 2 as viewed from a direction A in FIG. 2. FIG. 3 is a cross-sectional view illustrating a structure inside the coating unit when the coating unit 20 in FIG. 2 is viewed from a direction B in FIG. 2. FIG. 4C is a cross-sectional view illustrating the flow of the matrix resin 2 in the gap 26 in FIG. 4A. It is a figure showing an example of installation of a width regulation mechanism. FIG. 4 is a detailed cross-sectional view of a coating unit 20b according to another embodiment different from FIG. 2. FIG. 7 is a detailed cross-sectional view of a coating unit 20c according to another embodiment different from FIG. 6. FIG. 7 is a detailed cross-sectional view of a coating unit 20d according to another embodiment different from FIG. 6. FIG. 7 is a detailed cross-sectional view of a coating unit 20e according to another embodiment different from FIG. FIG. 4 is a detailed cross-sectional view of a coating unit 30 according to an embodiment different from the present invention. It is a figure showing the mode provided with the bar in the liquid pool part which is an example of an embodiment of the present invention. It is the schematic which shows the example of the prepreg manufacturing process and apparatus using this invention. It is the schematic of an example of another prepreg manufacturing process and apparatus using this invention. It is the schematic of an example of another prepreg manufacturing process and apparatus using this invention. It is the schematic of an example of another prepreg manufacturing process and apparatus using this invention. It is the schematic of an example of another prepreg manufacturing process and apparatus using this invention. It is the schematic of an example of another prepreg manufacturing process and apparatus using this invention.

  A preferred embodiment of the present invention will be described with reference to the drawings. Note that the following description exemplifies embodiments of the present invention, and the present invention is not construed as being limited thereto, and various modifications can be made without departing from the objects and effects of the present invention. .

<Outline of prepreg manufacturing method and manufacturing apparatus>
First, the outline of the method for producing a prepreg of the present invention will be described with reference to FIG. FIG. 1 is a schematic sectional view showing a prepreg manufacturing method and apparatus according to one embodiment of the present invention. The coating device 100 includes a transport roll 13 that transports the reinforcing fiber sheet 1a to the coating device 100, a direction changing roll 17 that changes the running direction of the reinforcing fiber sheet, and a reinforcing fiber sheet that comes into contact with the reinforcing fiber sheet 1a and is applied to the coating unit. It has a member 18 for guiding vertically downward Z and a transport roll 14, and an application section 20 in which the matrix resin 2 serving as an application mechanism is stored is provided between the member 18 and the transport roll 14. Further, before and after the coating apparatus 100, a plurality of creels 11 for unwinding the reinforcing fibers 1 and a reinforcing fiber sheet 1a in which the unwound reinforcing fibers 1 are arranged in one direction (in FIG. 1, arranged in the depth direction of the paper). And a winding device 15 for the prepreg 1b. The coating device 100 is provided with a matrix resin supply device (not shown). Further, if necessary, a release sheet supply device 16 for supplying the release sheet 3 can be provided.

<Reinforced fiber sheet>
Here, examples of the reinforcing fiber 1 include carbon fiber, glass fiber, metal fiber, metal oxide fiber, metal nitride fiber, organic fiber (aramid fiber, polybenzoxazole fiber, polyvinyl alcohol fiber, polyethylene fiber, etc.). However, it is preferable to use carbon fibers from the viewpoint of the mechanical properties and light weight of the FRP.

  Examples of the reinforcing fiber sheet used in the present invention include a UD substrate in which reinforcing fibers are arranged in one direction and a reinforcing fiber fabric as a woven fabric.

  The reinforcing fiber sheet arranged in one direction refers to a sheet in which a plurality of reinforcing fibers are arranged on a surface in one direction. That is, according to the production method of the present invention, after application of the matrix resin, it is obtained as a prepreg that is a sheet-like material impregnated with the matrix resin, and is referred to as a reinforcing fiber sheet for convenience as an array of reinforcing fibers. I have. A prepreg in which reinforcing fibers are arranged in one direction is a base material of FRP which is called “unidirectional material” or “UD material” in the composite material industry. Here, the thickness and width of the reinforcing fiber sheet are not particularly limited, and can be appropriately selected depending on the purpose and application. In the case of a carbon fiber, a fiber in which about 1,000 to about 1,000,000 single fibers are aggregated in a tape shape is called a "tow", and the tow is arranged to form a reinforcing fiber sheet. Although it can be obtained, tows may be laminated in the thickness direction. The reinforcing fiber sheet preferably has an aspect ratio defined by the width / thickness of 10 or more because it is easy to handle. In the present invention, one tape-shaped “toe” is also understood as one form of the reinforcing fiber sheet.

  The method for forming the reinforcing fiber sheet can be a known method, and is not particularly limited. A reinforcing fiber bundle in which single fibers are arranged in advance is formed, and the reinforcing fiber bundle is further arranged to form a reinforcing fiber. Forming a sheet is preferable from the viewpoints of process efficiency and uniform arrangement. For example, in carbon fiber, as described above, a `` toe '' which is a tape-shaped reinforcing fiber bundle is wound around a bobbin, and a reinforcing fiber sheet is obtained by arranging a tape-shaped reinforcing fiber bundle drawn out from this. Can be. It also has a reinforcing fiber arrangement mechanism for orderly arranging reinforcing fiber bundles drawn from creeled bobbins, eliminating undesirable overlapping and folding of reinforcing fiber bundles in reinforcing fiber sheets, and gaps between reinforcing fiber bundles. Is preferred. As the reinforcing fiber arranging mechanism, a known roller or comb-type arranging device can be used. It is also useful to stack a plurality of pre-arranged reinforcing fiber sheets from the viewpoint of reducing the gap between the reinforcing fibers. The creel is preferably provided with a tension control mechanism when drawing out the reinforcing fibers. As the tension control mechanism, a known mechanism can be used, and a brake mechanism or the like can be used. The tension can also be controlled by adjusting the thread guide.

  In addition, the reinforcing fiber fabric as the reinforcing fiber sheet of the present invention is a sheet in which reinforcing fibers are arranged in a multiaxial manner or randomly arranged. Specific examples thereof include those in which reinforcing fibers are two-dimensionally arranged in a multiaxial manner, and those in which reinforcing fibers such as a nonwoven fabric, a mat, and paper are randomly oriented, in addition to a woven fabric or a knitted fabric. In this case, the reinforcing fibers can be formed into a sheet using a method such as binder application, entanglement, welding, or fusion. As the woven fabric, a non-crimp woven fabric, a bias structure, an entangled woven fabric, a multiaxial woven fabric, a multiple woven fabric, or the like can be used in addition to the plain woven fabric, twill fabric, and satin woven fabric. The woven fabric combining the bias structure and the UD substrate not only suppresses the deformation of the woven fabric due to the tension in the coating / impregnation process due to the UD structure, but also has the pseudo-isotropy due to the bias structure, which is a preferable form. . In addition, the multi-layer fabric has an advantage that the structure / characteristics of the fabric upper / lower surface and the inside of the fabric can be individually designed. In the case of knitted fabrics, warp knitting is preferred in view of the form stability in the coating / impregnation step, but a blade which is a tubular knitted fabric can also be used.

  The thickness of the reinforcing fiber fabric is not particularly limited as long as the effects of the present invention can be obtained, and may be determined in consideration of the required FRP performance and the stability of the coating process. In consideration of the permeability of the stenosis, it is preferably 1 mm or less, more preferably 0.3 mm or less.

  A reinforcing fiber fabric suitable for the purpose can be obtained and manufactured from the market, and an example thereof will be described below. Examples of the woven fabric include “Toreca (registered trademark)” cloth C06142, C06347B, and C05642 manufactured by Toray Industries, Inc., and “HexForce (registered trademark)” Fabrics and “PrimeTex (registered trademark) 84, G0801 manufactured by HEXCEL. G108, which is a hybrid fabric of carbon fiber and glass fiber, such as GB201, G0986, G0926, etc. of carbon fiber and glass fiber. , G0874, G0973, 43743, etc., and 20796 and 21263 which are aramid fiber fabrics, and 610 and 593 which are Quartz fabrics. Examples of the nonwoven fabric, mat, and paper include “Torayca (registered trademark)” mats B030, B050, and BV03 manufactured by Toray Industries Co., Ltd. ZX-020 and the like.

<Smoothing of reinforcing fiber sheet>
In the present invention, by increasing the surface smoothness of the reinforcing fiber sheet, it is possible to improve the uniformity of the application amount in the application section. For this reason, it is preferable to guide the reinforcing fiber sheet to the liquid pool after performing the smoothing treatment. The method of smoothing is not particularly limited, and examples thereof include a method of physically pressing with a facing roll or the like, and a method of moving a reinforcing fiber using an air flow. The physical pressing method is preferred because it is simple and does not easily disturb the arrangement of the reinforcing fibers. More specifically, calendering or the like can be used. The method using an air flow is preferable because it not only causes less abrasion but also has the effect of widening the reinforcing fiber sheet.

<Widening of reinforced fiber sheet>
In the present invention, it is also preferable to guide the reinforcing fiber sheet to the liquid pool after widening the reinforcing fiber sheet from the viewpoint of efficiently producing a thin prepreg. There is no particular limitation on the widening processing method, and examples thereof include a method of mechanically applying vibration and a method of expanding the reinforcing fiber bundle by an air flow. As a method of mechanically applying vibration, there is a method of bringing a reinforcing fiber sheet into contact with a vibrating roll as described in, for example, JP-A-2015-22799. As the vibration direction, when the traveling direction of the reinforcing fiber sheet is the X axis, it is preferable to apply vibrations in the Y axis direction (horizontal direction) and the Z axis direction (vertical direction). It is also preferable to use them in combination. It is preferable that a plurality of projections are provided on the surface of the vibrating roll, because the abrasion of the reinforcing fibers by the roll can be suppressed. As a method using an air flow, for example, SEN-IGAKKAISHI, vol. 64, P-262-267 (2008). The described method can be used.

<Preheating of reinforced fiber sheet>
Further, in the present invention, it is preferable that the reinforcing fiber sheet is heated and then guided to the liquid pool portion, because the temperature decrease of the matrix resin can be suppressed and the viscosity uniformity of the matrix resin can be improved. The reinforcing fiber sheet is preferably heated to a temperature close to the matrix resin temperature. Examples of heating means for this include air heating, infrared heating, far infrared heating, laser heating, contact heating, and heating medium heating (such as steam). Means can be used. Above all, infrared heating is preferable because the apparatus is simple and the reinforcing fiber sheet can be directly heated, so that it can be efficiently heated to a desired temperature even at a high running speed.

<Members that contact the reinforcing fiber sheet>
In the present invention, the reinforcing fiber sheet is brought into contact with the member immediately before entering the application section storing the matrix resin, and then the reinforcing fiber sheet is guided to the matrix resin in the application section. As a result, it is possible to suppress the yarn cracking of the reinforcing fiber sheet and obtain a prepreg having a high uniformity of the basis weight in the width direction. The term “yarn cracking” as used herein refers to a phenomenon in which a gap is formed between the tows of the reinforcing fiber sheet that enters the matrix resin, and a portion where there is no reinforcing fiber in the prepreg. If there is a yarn crack in the reinforcing fiber sheet before entering the matrix resin, the yarn crack is often directly reflected in the prepreg after application of the matrix resin. In the present invention, as shown in FIG. 1, the reinforcing fiber sheet 1a is transported while being in contact with the member 18.

(Position of installation of components)
An installation position of the member 18 will be described in detail with reference to FIG. The member 18 for contacting the reinforcing fiber sheet 1a is installed at a position of 1 mm or more and 300 mm or less from the liquid surface of the matrix resin 2 stored in the application section 20. More specifically, as shown in FIG. 2A, the member 18 is installed such that the distance E from the liquid surface 27 of the matrix resin 2 stored in the application section to the lower end 19 of the member 18 is 1 mm or more and 300 mm or less. Thereby, yarn cracks in the reinforcing fiber sheet are suppressed, a prepreg having high uniformity in the weight per unit area in the width direction can be obtained, and workability in the manufacturing process can be ensured.

(Element)
As the member 18 to be brought into contact with the reinforcing fiber sheet 1a, various members can be used as long as the object of the present invention is achieved, and examples thereof include plate members, bars, and rolls. Among them, a fixed bar, a free roll, and a driving roll are preferable. The fixed bar is inexpensive and easy to install, and can also suppress the fluff wrapping around the roll. The free roll and the drive roll can make the frictional force between the reinforcing fiber sheet 1a and the member 18 appropriate, and can also suppress the accumulation of fluff on the member 18. The free roll means a roll that is not provided with a drive mechanism or a brake mechanism. The drive roll means a roll having a mechanism for rotating the rotation speed and the rotation speed at a constant speed using a driving force of a motor or the like. Various materials can be used as the material of the member 18 as long as the object of the present invention is achieved, but a metal having high rigidity is preferable, and stainless steel or the like is preferable. Thereby, deformation can be suppressed. Further, the inside of the member 18 does not need to be dense as long as the deformation can be suppressed. For example, a pipe or the like having a hollow inside may be used.

(Cross section of member)
The member 18 to be brought into contact with the reinforcing fiber sheet 1a preferably has no protrusion on the surface, that is, the member 18 preferably has a smooth curve without sharp corners. At this time, the accumulation of fluff can be suppressed, and yarn clogging or the like caused by bringing the fluff into the application section can be suppressed. The cross-sectional shape of the member 18 may be a circle illustrated in FIG. 2A or an elliptical shape.

(Surface roughness of member)
It is preferable that the surface roughness of the portion of the member 18 in contact with the reinforcing fiber sheet 1a is 1 μm or more and 20 μm or less. As a result, the fluff generated due to the rubbing with the reinforcing fiber sheet 1a can be suppressed, the process continuity can be improved, and the prepreg quality improving effect can be obtained. The surface roughness referred to here is the maximum height, and is the maximum height Rz measured according to JIS B0601 (2001). The surface roughness can be measured using a commercially available device capable of measuring the surface roughness. As an example of a device for measuring the surface roughness, the surface roughness can be measured using a Mitutoyo surface roughness meter (SV-C4500S4 or SJ-310).

(Contact length between reinforcing fiber sheet and member)
The contact length between the reinforcing fiber sheet 1a and the member 18 is preferably 5 mm or more and 200 mm or less. In this range, the generation of fluff due to the rubbing of the member and the reinforcing fiber sheet and the winding of the fluff around the member 18 can be suppressed, and the effect of improving the quality of the prepreg can be easily obtained while keeping the equipment compact. The contact length between the reinforcing fiber sheet 1a and the member 18 more specifically connects a point 28 where the reinforcing fiber sheet 1a contacts the member 18 and a point 29 where the reinforcing fiber sheet 1a separates from the member 18 as shown in FIG. 2a. The length of the arc.

  In FIG. 1, the direction changing roll 17 is used to bring the reinforcing fiber sheet 1a into contact with the member 18. However, for example, when the reinforcing fiber preheating device is not installed, or when the reinforcing fiber preheating device is compact, FIG. Of course, it is also possible to use the transport roll 13 as the member 18. Further, the direction changing roll 17 and the member 18 may have a heating mechanism. Thereby, by contact with the reinforcing fiber sheet heated by the reinforcing fiber preheating device, the reinforcing fiber sheet can be guided into the matrix resin of the application section without cooling.

<Matrix resin>
The matrix resin used in the present invention can be appropriately selected according to the purpose to be applied. For example, when applied to the production of a sheet-shaped prepreg, a matrix resin of the matrix resin can be used. The matrix resin-impregnated reinforced fiber sheet coated with the matrix resin obtained by the present invention is in a state where the matrix resin is impregnated into the reinforced fiber sheet, and it is possible to obtain a member made of FRP by directly laminating and molding as a sheet-like prepreg. it can. The degree of impregnation can be controlled by the design of the application section and the additional impregnation after application. The matrix resin can be appropriately selected depending on the application, but it is common to use a thermoplastic resin or a thermosetting resin. The matrix resin may be a molten resin heated and melted or a matrix resin at room temperature. Further, a solution or a varnish formed using a solvent may be used.

  As the matrix resin, those generally used for FRP, such as a thermoplastic resin, a thermosetting resin, and a photocurable resin, can be used. Further, these may be used as they are if they are liquids at room temperature, or may be used as solids or viscous liquids at room temperature to reduce the viscosity by heating, or may be used as a melt by melting, or a solvent. May be used as a solution or varnish.

  The thermoplastic resin is selected from a carbon-carbon bond, an amide bond, an imide bond, an ester bond, an ether bond, a carbonate bond, a urethane bond, a urea bond, a thioether bond, a sulfone bond, an imidazole bond, and a carbonyl bond in the main chain. A polymer having a bond can be used. Specifically, polyacrylate, polyolefin, polyamide (PA), aramid, polyester, polycarbonate (PC), polyphenylene sulfide (PPS), polybenzimidazole (PBI), polyimide (PI), polyetherimide (PEI), polysulfone (PSU), polyether sulfone (PES), polyether ketone (PEK), polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polyaryl ether ketone (PAEK), polyamide imide (PAI), etc. it can. In fields requiring heat resistance such as aircraft applications, PPS, PES, PI, PEI, PSU, PEEK, PEKK, PAEK, and the like are suitable. On the other hand, for industrial applications and automotive applications, polyolefins such as polypropylene (PP), PA, polyester, PPS, and the like are preferable in order to increase molding efficiency. These may be polymers or oligomers or monomers for low viscosity and low temperature coating. Of course, these may be copolymerized depending on the purpose, or may be used as a polymer blend alloy by mixing various types.

  Examples of the thermosetting resin include an epoxy resin, a maleimide resin, a polyimide resin, a resin having an acetylene terminal, a resin having a vinyl terminal, a resin having an allyl terminal, a resin having a nadic acid terminal, and a resin having a cyanate ester terminal. Can be These can be generally used in combination with a curing agent or a curing catalyst. In addition, these thermosetting resins can be appropriately used in combination.

  As a thermosetting resin suitable for the present invention, an epoxy resin is preferably used because of its excellent heat resistance, chemical resistance, and mechanical properties. In particular, an epoxy resin using an amine, a phenol, or a compound having a carbon-carbon double bond as a precursor is preferable. Specifically, various isomers of tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, and triglycidylaminocresol, and phenols are used as epoxy resins having amines as precursors. Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, a compound having a carbon-carbon double bond as a precursor Examples of the epoxy resin include, but are not limited to, alicyclic epoxy resins. Brominated epoxy resins obtained by brominating these epoxy resins are also used. An epoxy resin having an aromatic amine represented by tetraglycidyldiaminodiphenylmethane as a precursor has a good heat resistance and a good adhesion to a reinforcing fiber, and is most suitable for the present invention.

  A thermosetting resin is preferably used in combination with a curing agent. For example, in the case of an epoxy resin, the curing agent may be a compound having an active group capable of reacting with an epoxy group. Preferably, a compound having an amino group, an acid anhydride group, or an azide group is suitable. Specifically, dicyandiamide, various isomers of diaminodiphenylsulfone, and aminobenzoic acid esters are suitable. More specifically, dicyandiamide is preferably used because of its excellent prepreg preservability. Further, various isomers of diaminodiphenyl sulfone are most suitable for the present invention because they give cured products having good heat resistance. As the aminobenzoic acid esters, trimethylene glycol di-p-aminobenzoate and neopentyl glycol di-p-aminobenzoate are preferably used. Compared with diaminodiphenyl sulfone, the heat resistance is lower, but the tensile strength is lower. Because it is excellent, it is selected and used according to the application. It is also possible to use a curing catalyst if necessary. From the viewpoint of improving the pot life of the matrix resin, it is also possible to use a complexing agent capable of forming a complex with a curing agent or a curing catalyst.

  In the present invention, it is also preferable to use a thermoplastic resin mixed with a thermosetting resin. A mixture of a thermosetting resin and a thermoplastic resin gives better results than using the thermosetting resin alone. This is because the thermosetting resin is generally capable of low pressure molding by an autoclave while having a brittle defect, whereas the thermoplastic resin is generally difficult to perform low pressure molding by an autoclave while having the advantage of being tough. This is because they exhibit a trade-off characteristic, that is, they can be used in combination to balance physical properties and moldability. When mixed and used, it is preferable to contain the thermosetting resin in an amount of more than 50% by mass from the viewpoint of the mechanical properties of the FRP obtained by curing the prepreg.

<Polymer particles>
Further, in the present invention, it is preferable to use a matrix resin containing polymer particles since the toughness and impact resistance of the obtained CFRP can be improved. At this time, it is preferable that the glass transition temperature (Tg) or the melting point (Tm) of the polymer particles be higher than the matrix resin temperature by 20 ° C. or more, because the shape of the polymer particles can be easily maintained in the matrix resin. The Tg of the polymer particles can be measured using a temperature-modulated DSC under the following conditions. As the temperature modulation DSC device, Q1000 manufactured by TA Instruments or the like is suitable, and it can be used after being calibrated with high-purity indium in a nitrogen atmosphere. The measurement conditions are as follows: the temperature rise rate is 2 ° C./min, and the temperature modulation condition is a cycle of 60 seconds and an amplitude of 1 ° C. The reversible component is separated from the total heat flow obtained in this way, and the temperature at the middle point of the step signal can be set to Tg.

  In addition, Tm is measured by a normal DSC at a heating rate of 10 ° C./min, and the peak top temperature of a peak signal corresponding to melting can be defined as Tm.

  Further, it is preferable that the polymer particles do not dissolve in the matrix resin. As such polymer particles, for example, referring to WO 2009/142231 pamphlet and the like, appropriate ones can be used. More specifically, polyamide or polyimide can be preferably used, and polyamide, which can greatly improve impact resistance due to excellent toughness, is most preferable. As the polyamide, semi-IPN (polymer interpenetrating network structure) using polyamide 12, polyamide 11, polyamide 6, polyamide 66 or polyamide 6/12 copolymer, or the epoxy compound described in Example 1 of JP-A-01-104624. Polyamide (semi-IPN polyamide) or the like can be suitably used. The shape of the thermoplastic resin particles may be a spherical particle, a non-spherical particle, or a porous particle, but a spherical shape is particularly preferable in the production method of the present invention since the flow characteristics of the resin are not deteriorated. Further, a spherical shape is a preferable embodiment in that there is no starting point of stress concentration and high impact resistance is given.

  Commercially available polyamide particles include SP-500, SP-10, TR-1, TR-2, 842P-48, 842P-80 (all manufactured by Toray Industries, Inc.) and "Orgasol (registered trademark)" 1002D. , 2001UD, 2001EXD, 2002D, 3202D, 3501D, 3502D (all manufactured by Arkema Co., Ltd.), "Grillamide (registered trademark)" TR90 (manufactured by Mazaverke Co., Ltd.), "TROGAMID (registered trademark)" CX7323, CX9701 , CX9704 (manufactured by Degussa Co., Ltd.) and the like can be used. These polyamide particles may be used alone or in combination of two or more.

  Further, in order to increase the toughness of the CFRP interlayer resin layer, it is preferable to keep the polymer particles in the interlayer resin layer. Therefore, the number average particle size of the polymer particles is preferably in the range of 5 to 50 μm, more preferably in the range of 7 to 40 μm, and still more preferably in the range of 10 to 30 μm. By setting the number average particle diameter to 5 μm or more, the particles do not enter the bundle of the reinforcing fibers and can stay in the interlayer resin layer of the obtained fiber-reinforced composite material. By setting the number average particle size to 50 μm or less, the thickness of the matrix resin layer on the prepreg surface can be optimized, and thus, in the obtained CFRP, the fiber mass content can be optimized.

<Matrix resin viscosity>
As the matrix resin used in the present invention, it is preferable to select an optimum viscosity from the viewpoint of processability and stability. Specifically, when the viscosity is in the range of 1 to 60 Pa · s, it is possible to suppress the liquid dripping at the outlet of the constriction portion and to improve the high-speed running property and the stable running property of the reinforcing fiber sheet, which is preferable. Here, the viscosity refers to a value measured at a strain rate of 3.14 s ^-1 at the matrix resin temperature in the liquid reservoir. As the measuring device, a viscoelasticity measuring device such as a parallel disk type or a cone type can be used. The viscosity of the matrix resin is more preferably from 10 to 30 Pa · s.

<Coating process>
The coating step in the present invention will be described with reference to FIG. The method of applying the matrix resin 2 to the reinforcing fiber sheet 1a in the coating device 100 is as follows. The reinforcing device 1 is arranged by arranging a plurality of reinforcing fibers 1 unwound from the creel 11 in one direction (a depth direction in the drawing) by the arranging device 12. After the fiber sheet 1a is obtained, the running direction of the reinforcing fiber sheet 1a is further changed by the direction changing roll 17, and the reinforcing fiber sheet 1a is brought into contact with the member 18, and then passes through the application section 20 substantially in the vertical direction Z downward. The matrix resin 2 is applied to both sides of the reinforcing fiber sheet 1a. Thereby, the prepreg 1b can be obtained.

  In the present invention, the step of bringing the reinforcing fiber sheet 1a into contact with the member 18 may be a step as shown in FIG. 2A. The member 18 is set at a position of 1 mm or more and 300 mm or less from the liquid surface of the matrix resin 2 in which the reinforcing fiber sheet 1a is stored in the application section 20, and the reinforcing fiber sheet 1a and the member 18 are conveyed while being in contact with each other. The member 18 is set so that the distance E from the liquid surface 27 of the matrix resin stored in the application section 20 to the lower end 19 of the member 18 is within a range of 1 mm or more and 300 mm or less. By setting the distance E within this range, it is possible to suppress yarn breakage of the reinforcing fiber sheet 1a before entering the coating section 20, to obtain a prepreg having good quality and high uniformity in the weight per unit area in the width direction. Workability can be ensured. In order to obtain the effect of suppressing yarn breakage, it is preferable to shorten the distance E.

  As the member 18, a plate material, a bar, a roll, or the like can be used. Among them, a fixed bar, a free roll, and a driving roll are preferable. The fixed bar is inexpensive and easy to install, and can also suppress the fluff wrapping around the roll. The free roll and the drive roll can make the frictional force between the reinforcing fiber sheet 1a and the member 18 appropriate, and can also suppress the accumulation of fluff on the member 18. Further, it is preferable that the member to be used has no protrusion on the surface, that is, the member 18 has a smooth curve without sharp corners in the cross-sectional shape. At this time, generation of fluff can be suppressed, and process continuity can be improved. FIG. 2A illustrates the member 18 having a circular cross section, but may have an elliptical shape. The surface roughness of the portion of the member 18 that contacts the reinforcing fiber sheet is preferably 1 μm or more and 20 μm or less. Thereby, it is possible to suppress yarn breakage of the reinforcing fiber sheet 1a while suppressing generation of fluff caused by rubbing with the reinforcing fibers 1a, and as a result, an effect of improving prepreg quality is obtained. The surface roughness referred to here is the maximum height, and is the maximum height Rz measured according to JIS B0601 (2001). The surface roughness can be measured using a commercially available device capable of measuring the surface roughness. As an example of an apparatus for measuring the surface roughness, it can be measured using a Mitutoyo surface roughness meter (SV-C4500S4 or SJ-310).

  Further, the contact length between the reinforcing fiber sheet 1a and the member 18 is preferably 5 mm or more and 200 mm or less. When it is in this range, the effect of improving the quality of the prepreg is easily obtained while suppressing the generation of fluff due to the friction between the member and the reinforcing fiber sheet. The contact length between the reinforcing fiber sheet 1a and the member 18 will be described in detail with reference to FIG. 2A in which the cross-sectional shape of the member 18 is circular. This is the length of the arc connecting the separated points 29. In order to adjust the contact length between the reinforcing fiber sheet 1a and the member 18, it is necessary to change the size of the member 18 or to adjust the contact angle α between the reinforcing fiber sheet and the member if the member has a circular cross section. Alternatively, the position of the direction changing roll 17 can be changed.

  In FIG. 1, the direction changing roll 17 is used to bring the reinforcing fiber sheet 1a into contact with the member 18. However, for example, when there is no reinforcing fiber preheating device or when the reinforcing fiber preheating device is compact, the transport roll 13 in FIG. It is of course possible to achieve the object of the present invention by using as the member 18. Further, the direction changing roll 17 and the member 18 may have a heating mechanism. When the reinforcing fiber sheet is heated by the reinforcing fiber preheating device, the contact between the direction changing roll 17 and the member 18 causes the reinforcing fiber sheet to be heated. Can be suppressed from cooling.

  Further, if necessary, the release sheet 3 may be provided on at least one side of the prepreg 1b, and the winding device 15 may simultaneously wind the matrix resin-impregnated reinforced fiber sheet 1b and the release sheet 3 together. In particular, even if the matrix resin 2 applied to the prepreg 1b reaches the transport roll 14, if the matrix resin 2 is partially or entirely present on the prepreg 1b surface and has high fluidity or high adhesiveness, the release sheet 3, the transfer of a part of the matrix resin 2 on the surface of the prepreg 1b to the transport roll 14 can be prevented. Further, the adhesion between the prepregs 1b can be prevented, and the handling in the subsequent process becomes easy. The release sheet is not particularly limited as long as it has the above-mentioned effect, and examples thereof include release paper, and those obtained by applying a release agent to the surface of an organic polymer film.

  Next, a process of applying the matrix resin 2 to the reinforcing fiber sheet 1a will be described in detail with reference to FIGS. FIG. 2 is an enlarged detailed cross-sectional view of the application unit 20 in FIG. The coating unit 20 includes wall members 21a and 21b facing each other with a predetermined gap D therebetween, and a cross-sectional area between the wall members 21a and 21b is continuous in a vertically downward Z (that is, a running direction of the reinforcing fiber sheet). The liquid reservoir 22 which is gradually reduced, is located below the liquid reservoir 22 (the side where the reinforcing fiber sheet 1a is carried out), and is smaller than the cross-sectional area of the upper surface of the liquid reservoir 22 (the side where the reinforcing fiber sheet 1a is introduced). A slit-shaped constriction 23 having a cross-sectional area is formed. In FIG. 2, the reinforcing fiber sheets 1a are arranged in the depth direction of the paper surface.

  In the application section 20, the reinforcing fiber sheet 1a introduced into the liquid storage section 22 travels in the vertical downward direction Z while accompanying the matrix resin 2 around the reinforcement fiber sheet 1a. At this time, since the cross-sectional area of the liquid reservoir 22 decreases in the downward Z direction (the running direction of the reinforcing fiber sheet 1a), the accompanying matrix resin 2 is gradually compressed and moves toward the lower part of the liquid reservoir 22. As the pressure increases, the pressure of the matrix resin 2 increases. When the pressure in the lower part of the liquid reservoir 22 becomes higher, the accompanying liquid flow becomes more difficult to flow further downward, flows in the direction of the wall members 21a and 21b, and is then blocked by the wall members 21a and 21b and flows upward. Become like As a result, a circulating flow T is formed in the liquid reservoir 22 along the flat surface of the reinforcing fiber sheet 1a and the wall surfaces of the wall members 21a and 21b. Thereby, even if the sheet-like reinforcing fiber 1a brings the fluff into the liquid reservoir 22, the fluff moves along the circulating flow T and cannot approach the lower part of the liquid reservoir 22 or the narrowed portion 23 where the hydraulic pressure is large. . As described further below, the air bubbles adhere to the fluff, and the fluff moves upward from the circulating flow T and passes near the upper liquid level of the liquid reservoir 22. Therefore, not only is it possible to prevent the fluff from clogging the lower portion of the liquid reservoir 22 and the narrowed portion 23, but also it is possible to easily collect the retained fluff from the upper liquid surface of the liquid reservoir 22. Furthermore, when the reinforcing fiber sheet 1a is run at a high speed, the above-mentioned liquid pressure is further increased, so that the effect of eliminating fluff becomes higher. As a result, it becomes possible to apply the matrix resin 2 at a high speed to the reinforcing fiber sheet 1a, and productivity is greatly improved.

  In addition, the increased liquid pressure has an effect that the matrix resin 2 easily impregnates the inside of the reinforcing fiber sheet 1a. This is based on the property (Darcy's law) that when a matrix material is impregnated into a porous body such as a reinforcing fiber bundle, the degree of impregnation increases with the pressure of the matrix resin. Also in this case, when the reinforcing fiber sheet 1a is run at a higher speed, the hydraulic pressure is further increased, so that the impregnation effect can be further enhanced. Note that the matrix resin 2 is impregnated with air bubbles / liquid replacement with air bubbles remaining inside the reinforcing fiber sheet 1a. It is discharged in the orientation direction (vertically upward). At this time, since the bubbles are discharged without pushing the impregnated matrix resin 2, there is also an effect of not impairing the impregnation. Some of the air bubbles are discharged out of the surface of the reinforcing fiber sheet 1a in the out-of-plane direction (normal direction). However, the air bubbles are also quickly eliminated vertically upward by the above-mentioned liquid pressure and buoyancy. There is also an effect that the discharge of air bubbles proceeds efficiently without staying at the lower part of the liquid reservoir 22 having a high effect. These effects make it possible to efficiently impregnate the reinforcing fiber sheet 1a with the matrix resin 2, and as a result, obtain a high-quality matrix resin-impregnated reinforcing fiber sheet 1b in which the matrix resin 2 is uniformly impregnated. Becomes

  Further, the reinforcing fiber sheet 1a is automatically centered at the center of the gap D by the increased liquid pressure, and the reinforcing fiber sheet 1a does not directly rub against the wall surface of the liquid reservoir 22 or the narrowed portion 23. It also has the effect of suppressing the generation of fluff. This is because when the reinforcing fiber sheet 1a approaches one of the gaps D due to disturbance or the like, the matrix resin 2 is pushed into the narrower gap on the approaching side and is compressed, so that the hydraulic pressure increases on the approaching side. Then, the reinforcing fiber sheet 1a is pushed back to the center of the gap D.

  The constricted portion 23 is designed to have a smaller sectional area than the upper surface of the liquid reservoir 22. As understood from FIG. 2 and FIG. 4, the length of the pseudo plane made of the reinforcing fiber sheet in the perpendicular direction is small, that is, the interval between the members is small, so that the cross-sectional area becomes small. This is because the impregnation and the self-centering effect can be obtained by increasing the fluid pressure at the constricted portion as described above. The cross-sectional shape of the uppermost surface of the constricted portion 23 should be made to match the cross-sectional shape of the lowermost surface of the liquid reservoir 22, from the viewpoint of the running property of the reinforcing fiber sheet 1a and the flow control of the matrix resin 2. Although preferred, the constriction 23 may be slightly larger if necessary.

  Here, in the application section 20 of FIG. 2, the reinforcing fiber sheet 1a runs completely downward in the vertical direction Z (90 degrees from the horizontal plane), but the present invention is not limited to this. Is obtained, and the reinforcing fiber sheet 1a may be directed substantially vertically downward within a range in which the fiber sheet 1a can be stably and continuously driven.

  Further, the total amount of the matrix resin 2 applied to the reinforcing fiber sheet 1a can be controlled by the gap D of the narrowed portion 23. For example, it is desired to increase the total amount of the matrix resin 2 applied to the reinforcing fiber sheet 1a (to increase the basis weight). In this case, the wall members 21a and 21b may be installed so that the gap D is widened.

  FIG. 3 is a bottom view of the application unit 20 viewed from the direction of A in FIG. The coating unit 20 is provided with side wall members 24a, 24b for preventing the matrix resin 2 from leaking from both ends in the arrangement direction of the reinforcing fiber sheet 1a, and is surrounded by the wall members 21a, 21b and the side wall members 24a, 24b. An outlet 25 of the constricted portion 23 is formed in the closed space. Here, the outlet 25 has a slit shape, and the sectional aspect ratio (Y / D in FIG. 3) may be set according to the shape of the reinforcing fiber sheet 1a to which the matrix resin 2 is to be applied.

  FIG. 4A is a cross-sectional view illustrating the structure inside the coating unit when the coating unit 20 is viewed from the direction B. In addition, the wall member 21b is omitted for easy viewing, and the reinforcing fiber sheet 1a depicts the reinforcing fibers 1 so as to be arranged with a gap therebetween. Arrangement without any gap is preferable from the viewpoint of the quality of the sheet prepreg and the mechanical properties of the FRP.

  FIG. 4 b shows the flow of the matrix resin 2 in the gap 26. If the gap 26 is large, a vortex flows in the matrix resin 2 in the direction of R. Since the vortex flow R becomes a flow (Ra) directed outward at the lower portion of the liquid pool 22, the reinforcing fiber sheet may be torn (breakage of the sheet-like fiber bundle occurs) or the spacing between the reinforcing fibers may be reduced. When the matrix resin-impregnated reinforced fiber sheet is formed, the arrangement of the reinforced fibers may be uneven. On the other hand, in the upper part of the liquid reservoir 22, since the flow becomes inward (Rb), the reinforcing fiber sheet 1a is compressed in the width direction, and the end may be broken. In an apparatus represented by Patent Literature 2 (Japanese Patent No. 3252278) for applying a matrix resin on both sides of an integrated sheet-like base material (especially a film), a vortex flow in the gap 26 occurs. Also had little attention to quality.

Therefore, in the present invention, it is preferable to restrict the width of the gap 26 so as to suppress the generation of the vortex at the end. Specifically, the width L of the liquid reservoir 22, that is, the interval L between the side plate members 24a and 24b may be configured to satisfy the following relationship with the width W of the reinforcing fiber sheet measured immediately below the narrowed portion 23. preferable.
L ≦ W + 10 (mm)
As a result, generation of vortex flow at the end is suppressed, cracking and end breakage of the reinforcing fiber sheet 1a can be suppressed, and the reinforcing fibers 1 are arranged uniformly over the entire width (W) of the matrix resin-impregnated reinforcing fiber sheet 1b. Thus, a high-quality, high-stability matrix resin-impregnated reinforced fiber sheet 1b can be obtained. Furthermore, when this technology is applied to a prepreg, not only can the quality and quality of the prepreg be improved, but also the mechanical properties and quality of the FRP obtained using the prepreg can be improved. More preferably, when the relationship between L and W is L ≦ W + 2 (mm), cracks and end breaks in the reinforcing fiber sheet can be further suppressed.

  Further, it is preferable to adjust the lower limit of L to be not less than W-5 (mm) from the viewpoint of improving the uniformity of the dimension in the width direction of the matrix resin-impregnated reinforced fiber sheet 1b.

  Note that this width regulation is preferably performed at least at the lower part of the liquid reservoir 22 (the position G in FIG. 4A) from the viewpoint of suppressing the generation of the vortex R due to the high liquid pressure below the liquid reservoir 22. Further, more preferably, when this width regulation is performed in the entire area of the liquid pool 22, the generation of the vortex flow R can be almost completely suppressed, and as a result, cracks and end breaks of the reinforcing fiber sheet can be almost completely prevented. Can be suppressed.

  In addition, from the viewpoint of suppressing the vortex flow in the gap 26, the width regulation may be performed only on the liquid pool 22. However, when the constriction 23 is similarly performed, the excess amount of the matrix resin may It is preferable from the viewpoint of suppressing that 2 is given.

<Width regulation mechanism>
In the above description, the case where the side wall members 24a and 24b play the width regulation is shown. However, as shown in FIG. 5, width regulation mechanisms 27a and 27b may be provided between the side wall members 24a and 24b, and the width regulation may be performed by such a mechanism. it can. This is preferable from the viewpoint that the width regulated by the width regulating mechanism can be freely changed, so that a matrix resin-impregnated reinforced fiber sheet having various widths can be manufactured by one application portion. Here, the relationship between the width (W) of the reinforcing fiber sheet immediately below the constriction and the width (L2) regulated by the width regulating mechanism at the lower end of the width regulating mechanism is preferably L2 ≦ W + 10 (mm), More preferably, L2 ≦ W + 2 (mm). Further, it is preferable to adjust the lower limit of L2 to be not less than W-5 (mm) from the viewpoint of improving the uniformity of the dimension in the width direction of the matrix resin-impregnated reinforced fiber sheet 1b. There is no particular limitation on the shape and material of the width regulating mechanism, but a plate-shaped bush is simple and preferable. In the upper part, that is, at a place close to the liquid surface, the width is smaller than the distance between the wall members 21a and 21b (see FIG. 5; the vertical direction of the width regulating mechanism in the "view from the Z direction"). By having this, it is possible to prevent the matrix resin from flowing in the horizontal direction, which is preferable. On the other hand, it is preferable that the shape from the middle part to the lower part of the width regulating mechanism conforms to the internal shape of the application part, because the stagnation of the matrix resin in the liquid pool part can be suppressed and the deterioration of the matrix resin can be suppressed. In this sense, it is preferable that the width regulating mechanism is inserted up to the constriction 23. FIG. 5 shows an example of a plate-shaped bush as the width regulating mechanism, but shows an example in which the lower part from the middle of the bush follows the tapered shape of the liquid reservoir 22 and is inserted to the constriction 23. FIG. 5 shows an example in which L2 is constant from the liquid level to the outlet. However, the width regulated by the portion may be changed within a range that achieves the purpose of the width regulating mechanism. The width regulating mechanism can be fixed to the application section 20 by an arbitrary method. In the case of a plate-shaped bush, by fixing the plate-shaped bush at a plurality of portions in the up-down direction, regulation by deformation of the plate-shaped bush due to high hydraulic pressure. Variation in width can be suppressed. For example, it is preferable to use a stay for the upper portion and to insert the lower portion into the application portion, since the width can be easily regulated by the width regulating mechanism.

<Shape of liquid pool>
As described in detail above, in the present invention, the liquid pressure is increased in the running direction of the reinforcing fiber sheet by continuously decreasing the cross-sectional area in the running direction of the reinforcing fiber sheet in the liquid reservoir 22. It is important to note that the continuous decrease in the cross-sectional area in the running direction of the reinforcing fiber sheet is not particularly limited as long as the hydraulic pressure can be continuously increased in the running direction. In the cross-sectional view of the liquid reservoir, the liquid reservoir may have a curved shape such as a tapered shape (linear shape) or a trumpet shape. In addition, the cross-sectional area decreasing portion may be continuous over the entire length of the liquid pool portion, or may include a portion where the cross-sectional area does not decrease or a portion which expands conversely as long as the object and effects of the present invention can be obtained. You may go out. These will be described in detail below with reference to FIGS.

  FIG. 6 is a detailed cross-sectional view of the application section 20b of another embodiment different from FIG. It is the same as the coating unit 20 of FIG. 2 except that the shapes of the wall members 21c and 21d constituting the liquid pool 22 are different. As in the application part 20b of FIG. 6, the liquid reservoir 22 may be divided into a region 22a in which the cross-sectional area continuously decreases in the vertical direction Z downward, and a region 22b in which the cross-sectional area does not decrease. At this time, the vertical height H at which the cross-sectional area is continuously reduced is preferably 10 mm or more. The vertical height H at which the more preferable cross-sectional area is continuously reduced is 50 mm or more. As a result, the distance by which the matrix resin 2 entrained by the reinforcing fiber sheet 1a is compressed in the region 22a where the cross-sectional area of the liquid reservoir 22 is continuously reduced is secured, and the liquid generated in the lower portion of the liquid reservoir 22 is secured. The pressure can be increased sufficiently. As a result, it is possible to prevent the fluff from clogging the constricted portion 23 due to the liquid pressure, and to obtain the effect that the matrix resin 2 impregnates the reinforcing fiber sheet 1a with the liquid pressure.

  Here, when the region 22a where the cross-sectional area of the liquid reservoir 22 is continuously reduced is tapered like the coating portion 20 in FIG. 2 or the coating portion 20b in FIG. 6, the opening angle θ of the taper is smaller. More specifically, it is preferable to form an acute angle (90 ° or less). Thereby, the compression effect of the matrix resin 2 can be enhanced in the region 22a (tapered portion) where the cross-sectional area of the liquid reservoir 22 is continuously reduced, and a high liquid pressure can be easily obtained.

  FIG. 7 is a detailed cross-sectional view of the application unit 20c of another embodiment different from FIG. It is the same as the application section 20b of FIG. 6 except that the shape of the wall members 21e and 21f constituting the liquid pool section 22 is a two-step tapered shape. As described above, the region 22a where the cross-sectional area of the liquid reservoir 22 is continuously reduced may be configured by a multi-stage taper portion of two or more stages. At this time, it is preferable to make the opening angle θ of the tapered portion closest to the constricted portion 23 an acute angle from the viewpoint of enhancing the compression effect. Also in this case, it is preferable that the height H of the region 22a where the cross-sectional area of the liquid reservoir 22 is continuously reduced is 10 mm or more. The vertical height H at which the more preferable cross-sectional area is continuously reduced is 50 mm or more. As shown in FIG. 7, the area 22a where the cross-sectional area of the liquid reservoir 22 is continuously reduced is formed as a multi-stage tapered portion, so that the volume of the matrix resin 2 that can be stored in the liquid reservoir 22 is maintained while the constricted portion 23 is maintained. Can be further reduced. As a result, the liquid pressure generated in the lower portion of the liquid reservoir 22 is further increased, and the effect of removing fluff and the effect of impregnating the matrix resin 2 can be further enhanced.

  FIG. 8 is a detailed cross-sectional view of a coating unit 20d according to another embodiment different from FIG. It is the same as the application section 20b in FIG. 6 except that the shape of the wall members 21g and 21h constituting the liquid pool section 22 is stepped. As described above, if there is a region 22a in which the cross-sectional area is continuously reduced at the lowermost portion of the liquid reservoir 22, the effect of increasing the hydraulic pressure, which is the object of the present invention, can be obtained. May include a region 22c in which the cross-sectional area decreases intermittently. By forming the liquid reservoir 22 in a shape as shown in FIG. 8, the depth B of the liquid reservoir 22 can be increased and stored while maintaining the shape of the region 22 a where the cross-sectional area is continuously reduced. The volume can be increased. As a result, even when the matrix resin 2 cannot be continuously supplied to the application section 20d, the matrix resin 2 can be continuously applied to the reinforcing fiber sheet 1a for a long time, and the productivity of the matrix resin impregnated reinforcing fiber sheet 1b can be further improved. improves.

  FIG. 9 is a detailed cross-sectional view of a coating unit 20e according to another embodiment different from FIG. It is the same as the application section 20b in FIG. 6, except that the shape of the wall members 21i and 21j forming the liquid pool section 22 is a trumpet shape (curved shape). In the application section 20b of FIG. 6, the area 22a where the cross-sectional area of the liquid pool section 22 is continuously reduced is tapered (straight), but is not limited to this. For example, as shown in FIG. May be. However, it is preferable that the lower part of the liquid pool part 22 and the upper part of the narrow part 23 are connected smoothly. This is because if there is a step at the boundary between the lower part of the liquid pool part 22 and the upper part of the narrow part 23, the reinforcing fiber sheet 1a is caught by the step, and there is a concern that fluff is generated at this part. When the region where the cross-sectional area of the liquid reservoir 22 is continuously reduced is a trumpet-like shape, the opening of the virtual tangent line at the lowermost part of the region 22a where the cross-sectional area of the liquid reservoir 22 is continuously reduced. It is preferable that the angle θ be an acute angle.

  In the above description, an example in which the cross-sectional area is smoothly reduced has been described. However, in the present invention, the cross-sectional area of the liquid reservoir does not necessarily have to be smoothly reduced unless the object of the present invention is impaired.

  FIG. 10 is a detailed cross-sectional view of a coating unit 30 according to another embodiment different from the present invention. Unlike the embodiment of the present invention, the liquid reservoir 32 in FIG. 10 does not include a region where the cross-sectional area continuously decreases in the vertical downward direction Z, and the cross-sectional area at the boundary 33 with the constriction 23 is discontinuous and sharp. It is a structure which reduces to. Therefore, the reinforcing fiber sheet 1a is easily clogged.

  In addition, it is also possible to improve the impregnation effect by bringing the reinforcing fiber sheet into contact with a plurality of bars in the application section. FIG. 11 shows an example in which three bars (35a, 35b and 35c) are used. The greater the number of bars, the longer the contact length between the reinforcing fiber sheet and the bars, the larger the contact angle, the greater the impregnation rate. Can be improved. In the example of FIG. 11, the impregnation rate can be 90% or more. The means for improving the impregnation effect may be used in combination of plural kinds.

<Travel mechanism>
As a traveling mechanism for transporting the reinforcing fiber sheet or the matrix resin-impregnated reinforcing fiber sheet of the present invention, a known roller or the like can be suitably used. In the present invention, since the reinforcing fiber sheet is conveyed vertically downward, it is preferable to arrange rollers vertically above and below the application section.

  In the present invention, it is preferable that the running path of the reinforcing fiber sheet is as linear as possible in order to suppress the arrangement disorder and the fluffing of the reinforcing fibers. Further, in the conveying step of the sheet-like integrated body which is a laminate of the matrix resin-impregnated reinforced fiber sheet and the release sheet, if there is a bent portion, wrinkles may occur due to a difference in circumference between the inner layer and the outer layer. It is preferable that the traveling path of the shape-integrated object is also as straight as possible. From this viewpoint, it is preferable to use a nip roll in the traveling path of the sheet-like integrated object.

  Whether to use the S-shaped roll or the nip roll can be appropriately selected according to the manufacturing conditions and the characteristics of the product.

<High tension take-up device>
In the present invention, it is preferable that a high tension take-off device for pulling out the matrix resin-impregnated reinforced fiber sheet from the application section is disposed downstream of the application section in the process. This is because high frictional force and shear stress are generated between the reinforcing fiber sheet and the matrix resin at the application section, and high pulling tension is generated downstream in the process to overcome and draw out the matrix resin-impregnated reinforcing fiber sheet. This is because it is preferable to make them. A nip roll or S-shaped roll can be used as the high tension take-off device, but any of them can increase slipping force between the roll and the matrix resin-impregnated reinforced fiber sheet to prevent slip and enable stable running. It can be. For this purpose, it is preferable to arrange a material having a high coefficient of friction on the roll surface, or to increase the nip pressure or the pressing pressure of the matrix resin-impregnated reinforced fiber sheet on the S-shaped roll. From the viewpoint of preventing the slip, the S-shaped roll is preferable because the frictional force can be easily controlled by the roll diameter and the contact length.

<Release sheet feeding device, winder>
In the production of a prepreg or FRP using the present invention, a release sheet feeding device or a winder can be used as appropriate, and as such a device, a known device can be used. It is preferable to provide a mechanism capable of feeding back the winding tension or feeding back the winding speed from the viewpoint of stable running of the sheet.

<Addition impregnation>
In order to adjust the degree of impregnation to a desired degree, it is also possible to combine a means for further increasing the degree of impregnation using an impregnating apparatus separately after coating with the present invention. Here, in order to distinguish it from the impregnation in the application section, additional impregnation after application is referred to as additional impregnation, and an apparatus therefor is referred to as an additional impregnation apparatus. The device used as the additional impregnation device is not particularly limited, and can be appropriately selected from known devices according to the purpose. For example, as described in JP-A-2011-132389 and WO2015 / 060299, after laminating a sheet-like carbon fiber bundle and a resin with a hot plate and sufficiently softening the resin on the sheet-like carbon fiber bundle, The impregnation can also be advanced by using a device that presses with a heated nip roll. The temperature of the hot plate for preheating, the surface temperature of the nip roll, the linear pressure of the nip roll, and the diameter and number of the nip rolls can be appropriately selected so as to obtain a desired impregnation degree. It is also possible to use an “S-wrap roll” in which a prepreg sheet travels in an S-shape as described in WO 2010/150022 pamphlet. In the present invention, “S-wrap roll” is simply referred to as “S-shaped roll”. WO 2010/150022 Pamphlet FIG. 1 shows an example in which the prepreg sheet runs in an S-shape, but if impregnation is possible, the contact length between the sheet and the roll, such as a U-shape, V-shape or Λ-shape, is described. May be adjusted. When the impregnation pressure is increased to increase the degree of impregnation, it is also possible to add an opposing contact roll. Further, as shown in FIG. 4 of the pamphlet of WO2015 / 076981, it is possible to improve the impregnation efficiency by arranging the conveyor belt opposite to the “S-wrap roll”, thereby increasing the production speed of the prepreg. Further, as described in WO 2017/068159 pamphlet or JP-A-2006-20397, etc., it is possible to improve the impregnation efficiency by applying ultrasonic waves to the prepreg before impregnation and rapidly raising the temperature of the prepreg. is there. Further, as described in JP-A-2017-154330, it is also possible to use an impregnation device that vibrates a plurality of “ironing blades” with an ultrasonic generator. Further, it is also possible to fold and impregnate the prepreg as described in JP-A-2013-22868.

<Simple additional impregnation>
In the above, an example in which the conventional additional impregnation apparatus is applied is shown, but the temperature of the matrix resin-impregnated reinforcing fiber sheet may still be high immediately below the application section, and in such a case, after leaving the application section, it is not so much. If the additional impregnation operation is performed before the time has passed, a heating device such as a hot plate for reheating the matrix resin-impregnated reinforced fiber sheet is omitted or simplified, and the impregnation device is greatly simplified and downsized. It is also possible. Such an impregnating device located immediately below the coating section is referred to as a simple additional impregnating device. As a simple additional impregnating device, a heating nip roll or a heated S-shaped roll can be used, but the roll diameter, the set pressure, and the contact length between the prepreg and the roll can be reduced as compared with a normal impregnating device, and the device can be downsized. This is preferable because power consumption can be reduced as much as possible.

  It is preferable that a release sheet be provided to the matrix resin-impregnated reinforced fiber sheet before the matrix resin-impregnated reinforced fiber sheet enters the simple re-impregnation apparatus, because the running property of the prepreg is improved. FIG. 15 shows an example of an apparatus for manufacturing a matrix resin-impregnated reinforced fiber sheet incorporating a simple additional impregnation apparatus.

<Impregnation rate>
In the matrix resin-impregnated reinforced fiber sheet obtained by the production method of the present invention, the matrix resin impregnation ratio is desirably 10% or more. The impregnation rate of the matrix resin can be checked for the presence or absence of impregnation by tearing the collected matrix resin-impregnated reinforced fiber sheet and visually observing the inside, and can be more quantitatively evaluated by, for example, a peeling method. . The impregnation rate of the matrix resin by the peeling method can be measured as follows. That is, the collected matrix resin-impregnated reinforced fiber sheet is sandwiched between adhesive tapes and peeled off to separate the reinforced fibers with the matrix resin from the reinforced fibers without the matrix resin. Then, the ratio of the mass of the reinforcing fibers to which the matrix resin has adhered to the mass of the entire reinforcing fiber sheet put in can be taken as the impregnation rate of the matrix resin by the peeling method.

<Prepreg width>
Since prepreg, which is a kind of precursor of FRP, is a form of matrix resin-impregnated reinforced fiber sheet obtained in the present invention, when applying the present invention to FRP applications, the matrix resin-impregnated reinforced fiber sheet is referred to as prepreg. This will be described below.

  The width of the prepreg is not particularly limited, and may be a wide width of about several tens cm to 2 m or a tape having a width of several mm to several tens mm. The width can be selected according to the application. In recent years, devices called ATL (Automated Tape Laying) or AFP (Automated Fiber Placement) for automatically laminating narrow prepregs and prepreg tapes have been widely used in order to increase the efficiency of the prepreg lamination process. Therefore, it is also preferable that the width is adjusted to this. ATL often uses a narrow prepreg having a width of about 7.5 cm, about 15 cm, or about 30 cm. AFP often uses a prepreg tape having a width of about 3 mm to about 25 mm.

  There is no particular limitation on a method of obtaining a prepreg having a desired width, and a method of slitting a wide prepreg having a width of about 1 m to 2 m into a narrow width can be used. Further, in order to simplify or omit the slitting step, the width of the coating portion used in the present invention can be adjusted so as to have a desired width from the beginning. For example, when manufacturing a narrow prepreg having a width of 30 cm for ATL, the width of the application section outlet may be adjusted accordingly. In addition, in order to manufacture this efficiently, it is preferable to manufacture the product with a product width of 30 cm. When a plurality of such manufacturing devices are arranged in parallel, the same traveling device / transport device, various rolls, and a winder are used. The prepreg of the line can be manufactured. FIG. 17 shows an example in which five application sections are connected in a parallel direction. At this time, the five reinforcing fiber sheets 416 may pass through the five independent reinforcing fiber preheating devices 420 and the application unit 430, respectively, to obtain five prepregs 471, or the reinforcing fiber preheating device 420 The application section 430 may be integrated in the parallel direction. In this case, the coating unit 430 may be provided with five independent width control mechanisms and five coating unit outlet widths.

  In the case of a prepreg tape, the tape-shaped reinforcing fiber bundle is formed into a reinforcing fiber sheet with about 1 to 3 yarns, and the reinforcing fiber sheet is passed through an application section whose width is adjusted so as to obtain a desired tape width. You can also get it. In the case of a prepreg tape, in particular, the accuracy of the tape width is often required from the viewpoint of controlling the lateral overlap between the tapes. For this reason, it is preferable to more strictly control the outlet width of the application section. In this case, it is preferable that the above L, L2, and W satisfy the relationship of L ≦ W + 1 mm and / or L2 ≦ W + 1 mm. .

<Slit>
The method of slitting the prepreg is not particularly limited, and a known slit device can be used. After winding the prepreg once, it may be installed in the slit device again to perform slitting, or for efficiency, a slitting step may be arranged continuously from the prepreg producing step without winding the prepreg once. Also, in the slitting step, a wide prepreg of 1 m or more may be directly slit to a desired width, or once cut and divided into narrow prepregs of about 30 cm, and then slit again to a desired width. good.

  In addition, when the above-mentioned narrow prepreg and prepreg tape are arranged in a plurality of coating portions in parallel, a release sheet may be supplied independently, or one wide release sheet may be supplied. A plurality of prepregs may be stacked. The end in the width direction of the prepreg thus obtained can be cut off and supplied to an ATL or AFP device. In this case, since most of the cut-off end is a release sheet, the matrix resin component (resin component in the case of CFRP) adhering to the slit cutter blade can be reduced, and the cleaning cycle of the slit cutter blade is extended. There is also an advantage that you can do it.

<Matrix resin supply mechanism>
In the present invention, the matrix resin is stored in the coating section, but it is preferable to appropriately supply the matrix resin because the coating proceeds. The mechanism for supplying the matrix resin to the application section is not particularly limited, and a known device can be used. It is preferable that the matrix resin be continuously supplied to the application section because the running of the reinforcing fiber sheet can be stabilized without disturbing the liquid level above the application section. For example, the self-weight can be supplied as a driving force from a tank storing the matrix resin, or can be supplied continuously using a pump or the like. As the pump, a gear pump, a tube pump, a pressure pump, or the like can be used as appropriate according to the properties of the matrix resin. When the matrix resin is solid at room temperature, it is preferable to provide a melter above the reservoir. Further, a continuous extruder or the like can be used. Further, it is preferable to provide a mechanism capable of continuously supplying the matrix resin in accordance with the applied amount so that the liquid level above the application portion of the matrix resin is as constant as possible. For this purpose, for example, a mechanism that monitors the liquid level, the weight of the application section, and the like and feeds it back to the supply device is conceivable.

<Online monitoring>
Further, it is preferable to provide a mechanism capable of online monitoring of the application amount for monitoring the application amount. The online monitoring method is not particularly limited, and a known method can be used. For example, as a device for measuring the thickness, for example, a beta-ray meter or the like can be used. In this case, it is possible to estimate the coating amount by measuring the thickness of the reinforcing fiber sheet and the thickness of the matrix resin-impregnated reinforcing fiber sheet and analyzing the difference. The application amount monitored online is immediately fed back to the application unit, and can be used for adjusting the temperature of the application unit and the gap D (see FIG. 2) of the constricted portion 23. Application amount monitoring can of course be used as defect monitoring. As the thickness measurement position, for example, in FIG. 12, the thickness of the reinforcing fiber sheet 416 is measured in the vicinity of the direction changing roll 419, and the thickness of the matrix resin impregnated reinforcing fiber sheet is measured between the application section 430 and the direction changing roll 441. can do. It is also preferable to perform online defect monitoring using infrared rays, near infrared rays, a camera (image analysis), or the like.

  The prepreg manufacturing apparatus of the present invention has a traveling mechanism for causing a reinforcing fiber sheet in which reinforcing fibers are arranged in one direction to travel substantially vertically downward, and a coating mechanism, and the coating mechanism includes a matrix resin therein. It is storable, and further comprises a liquid reservoir and a constricted portion that are communicated with each other, wherein the liquid reservoir has a portion whose cross-sectional area decreases continuously along the running direction of the reinforcing fiber sheet, The constricted portion has a slit-shaped cross-section, has a cross-sectional area smaller than the upper surface of the liquid reservoir portion, and forms a reinforcing fiber sheet at a position of 1 mm or more and 300 mm or less from the liquid surface of the matrix resin stored in the application portion. The vehicle travels while contacting the vehicle.

  Hereinafter, the present invention will be described in more detail with specific examples of prepreg production. Note that the following is an example, and the present invention is not construed as being limited to the embodiments described below.

  FIG. 12 is a schematic view of an example of a prepreg manufacturing process / apparatus using the present invention. The plurality of reinforcing fiber bobbins 412 are hung on a creel 411, and are pulled out upward through a direction changing guide 413. At this time, the reinforcing fiber bundle 414 can be pulled out with a constant tension by the brake mechanism provided to the creel. The plurality of pulled out reinforcing fiber bundles 414 are orderly arranged by the reinforcing fiber arrangement device 415, and the reinforcing fiber sheet 416 is formed. In FIG. 12, only three yarns are drawn on the reinforcing fiber bundle. However, in practice, the reinforcing fiber bundle can be made from two yarns to several hundreds of yarns, and can be adjusted to have a desired prepreg width and fiber weight. is there. Thereafter, the sheet is conveyed vertically downward through a widening device 417, a smoothing device 418, and a direction change roll 419. In FIG. 12, the reinforcing fiber sheet 416 is conveyed linearly between the reinforcing fiber arrangement devices 415 to the direction change roll 419 between the devices. Note that the widening device 417 and the smoothing device 418 can be appropriately skipped or the devices can be omitted depending on the purpose. The arrangement order of the reinforcing fiber arrangement device 415, the widening device 417, and the smoothing device 418 can be appropriately changed according to the purpose. The reinforcing fiber sheet 416 travels vertically downward from the direction changing roll 419, passes through the reinforcing fiber preheating device 420, and changes the running direction with the direction changing roll 421 to contact the member 422. The reinforcing fiber preheating device 420 can be skipped or the device can be omitted.

  The step of bringing the reinforcing fiber sheet 1a into contact with the member 422 can be, for example, a step as shown in FIG. 2A. A member 18 is provided immediately above the application section 20, and conveys the reinforcing fiber sheet so that the reinforcing fiber sheet 1a and the member 18 come into contact with each other. The member 18 is set in contact with a distance E from the liquid surface 27 of the matrix resin 2 stored in the application section 20 to the lower end 19 of the member 18 within a range of 1 mm or more and 300 mm or less. By setting E in this range, it is possible to suppress yarn breakage of the reinforcing fiber sheet 1a before entering the coating section 20, to obtain a prepreg having good quality and high uniformity in the width direction, and workability in the manufacturing process. Is also possible. In order to obtain the effect of suppressing the yarn breakage by the member 18 of the present invention, it is preferable to shorten E. As the member 18 in FIG. 2a, a member having no projection on its surface, that is, a cross-sectional shape preferably has no sharp corners and is formed of a smooth curve. At this time, generation of fluff can be suppressed, and the process stability can be improved. Further, it is preferable that the surface roughness of the portion of the member 18 in contact with the reinforcing fiber sheet is 1 μm or more and 20 μm or less. Thereby, the prepreg quality improvement effect can be obtained while maintaining the process stability due to the fluff generated by rubbing with the reinforcing fiber sheet 1a. The surface roughness referred to here is the maximum height, which is the maximum height Rz measured according to JIS B 0601 (2001). The surface roughness can be measured using a commercially available device capable of measuring the surface roughness. As an example of an apparatus for measuring the surface roughness, it can be measured using a Mitutoyo surface roughness meter (SV-C4500S4 or SJ-310).

  In addition, as the member 18, a plate material, a bar, a roll, or the like can be used, and among them, it is preferable to use a fixed bar, a free roll, or a driving roll. Thereby, the winding of the fluff can be suppressed, the frictional force between the reinforcing fiber sheet 1a and the member 18 can be made appropriate, and the accumulation of the fluff on the member 18 can also be suppressed.

  The contact length between the reinforcing fiber sheet 1a and the member 18 does not matter, but is preferably 5 mm or more and 200 mm or less. In this range, the generation of fluff due to friction between the member and the reinforcing fiber sheet is suppressed, the equipment is kept compact, and the effect of improving the quality of the prepreg is easily obtained. The contact length between the reinforcing fiber sheet 1a and the member 18 is the length of the arc connecting the point 28 where the reinforcing fiber sheet 1a contacts the member 18 and the point 29 where the reinforcing fiber sheet 1a separates from the member 18 in FIG. In addition, as a member, in order to adjust the contact length between the reinforcing fiber sheet 1a and the member 18, the adjustment can be performed by changing the size of the member 18 or adjusting the contact angle α between the reinforcing fiber sheet and the member. . It is also possible to change the position of the direction change roll 421 shown in FIG.

  In FIG. 1, the direction changing roll 17 is used in order to bring the reinforcing fiber sheet 1a into contact with the member 18. However, for example, when there is no preheating of the reinforcing fiber sheet, or when the reinforcing fiber sheet preheating device is compact, the conveyance of FIG. It is of course possible to achieve the object of the present invention by using the roll 13 as the member 18. When using the reinforcing fiber sheet preheating device 420 for the reinforcing fiber sheet 1a, when the temperature of the direction change roll 421 or the member 422 is lower than the surface temperature of the heated reinforcing fiber 1a, the surface temperature of the reinforcing fiber sheet 1a is cooled. Therefore, the direction changing roll 421 and the member 422 may have a heating mechanism.

  The reinforcing fiber sheet 1a that has come into contact with the member 422 is conveyed vertically downward, and reaches the direction change roll 441 via the application unit 430. The application section 430 can adopt any application section shape as long as the object of the present invention is achieved. For example, shapes as shown in FIG. 2 and FIGS. Further, a bush can be provided as shown in FIG. 5 as necessary. Further, as shown in FIG. 11, a bar can be provided in the application section. In FIG. 12, the release sheet 446 unwound from the release sheet (upper) supply device 442 is laminated on a matrix resin-impregnated reinforced fiber sheet, in this case, a prepreg 471, on a direction change roll 441, and the sheet-like integrated material is formed. can do. Furthermore, the release sheet 446 unwound from the release sheet (lower) supply device 443 can be inserted into the lower surface of the sheet-like integrated body. Here, release paper, release film, or the like can be used as the release sheet. This can be taken off by the high tension take-up device 444. In FIG. 12, a nip roll is drawn as the high tension take-up device 444. Thereafter, the sheet-like integrated material passes through an additional impregnating device 450 provided with a hot plate 451 and a heating nip roll 452, is cooled by a cooling device 461, is taken off by a take-off device 462, and peels off the upper release sheet 446. Then, a sheet-like integrated body 472 composed of a prepreg / release sheet as a product can be obtained by winding with a winder 464. Since the sheet-like integrated object is conveyed in a basic straight line from the direction changing roll 441 to the winder 464, generation of wrinkles can be suppressed. In FIG. 12, the illustration of the matrix resin supply device and the on-line monitoring device is omitted. By using the matrix resin supply device, the liquid level of the matrix resin stored in the application section can be maintained.

  FIG. 13 is a schematic view of another example of a prepreg manufacturing process / apparatus using the present invention. In FIG. 13, the reinforcing fiber bundle 414 is pulled out from the creel 411, the reinforcing fiber sheet 416 is formed as it is by the reinforcing fiber arrangement device 415, and thereafter, is linearly conveyed to the widening device 417 and the smoothing device 418. The difference from FIG. 12 is that the sheet 416 is guided upward. With such a configuration, it is not necessary to install the device above, and the installation of a scaffold or the like can be greatly simplified.

  FIG. 14 is a schematic view of another example of a prepreg manufacturing process / apparatus using the present invention. In FIG. 14, a creel 411 is installed on the floor, and the traveling route of the reinforcing fiber sheet 416 is further linearized.

  FIG. 15 is a schematic view of another example of a prepreg manufacturing process / apparatus using the present invention. An example in which a simple additional impregnation device is used instead of the ordinary additional impregnation device shown in FIG. 12 is shown. In FIG. 15, since the simple additional impregnating device 453 is installed immediately below the coating unit 430, the matrix resin impregnated reinforced fiber sheet 471 is guided to the simple additional impregnating device 453 in a high temperature state. Can be downsized. In FIG. 15, the heating nip roll 454 is illustrated as an example, but a small heating S-shaped roll may be used depending on the purpose. The use of the simple additional impregnation apparatus is also advantageous in that the entire prepreg manufacturing apparatus can be made very compact.

  FIG. 16 is a schematic view of another example of a prepreg manufacturing process / apparatus using the present invention. FIG. 16 shows an example in which a high tension take-off S-shaped roll 449 is used as the high tension take-off device, and two S-2 rolls 455 of the “S-wrap roll” type are used as the additional impregnating device (two rolls-two sets in total). Although the drawing is performed, the number of rolls can of course be increased or decreased according to the purpose. Further, in FIG. 16, a contact roll 456 for enhancing the impregnation effect is also drawn, but it is of course possible to omit it depending on the purpose.

  FIG. 17 is a schematic view of another example of a prepreg manufacturing process / apparatus using the present invention. In this example, an example is shown in which a heated S-shaped roll of the "S-wrap roll" type is also used as a high tension take-up device. There is an advantage that the entire prepreg manufacturing apparatus can be made very compact.

<Prepreg manufacturing equipment>
As a prepreg manufacturing apparatus, an apparatus having the configuration shown in FIG. 12 (the drawing is omitted from the matrix resin supply apparatus), and a step shown in FIG. The widening device 417, the smoothing device 418, the additional impregnation device 450, and the cooling device 461 were not used.

  The reinforcing fibers are pulled out from the reinforcing fiber bobbin 412 hung on the creel 411, and the reinforcing fiber 56 is arranged in the width direction by the reinforcing fiber arranging device 415 to form the reinforcing fiber sheet 416, and then reinforced by the direction changing roll 419. After changing the conveying direction of the fiber sheet from the horizontal direction to the vertical direction and passing the reinforcing fiber preheating device 420, the conveying direction is changed by the direction changing roll 421 so that the reinforcing fiber sheet 416 contacts the member 422, and the member 422 is contacted. The reinforced fiber sheet 416 thus obtained was caused to enter the application section 430 vertically downward, and a matrix resin was applied to both surfaces of the reinforced fiber sheet 416 to obtain a prepreg 471. The release sheet 446 is unwound from the release sheet (upper) supply device 442 and the release sheet (lower) supply device 443 on the obtained prepreg, and is taken out by a high tension take-up device 444 of a nip roll type. (Upper) The release sheet on one side was peeled off by the winding supply device 463, and the prepreg / release sheet (sheet-like integrated body) 472 was wound. During the production of the prepreg / release sheet (sheet-like integrated material) 472, the matrix resin is supplied using a matrix resin supply device so that the liquid level of the matrix resin stored in the application section 430 becomes constant. Was.

<Members contacting the reinforcing fiber sheet>
The step of bringing the member into contact with the reinforcing fiber sheet was performed with the configuration shown in FIG. 2A. As the member 18 to be brought into contact with the reinforcing fiber sheet 1a, a free roll having a material of stainless steel, a surface roughness of 6.3 μm, a circular cross section and a diameter of 60 mm was used. The member 18 was installed such that the distance E from the liquid surface 27 of the matrix resin stored in the coating section 20 to the lower end 19 of the member 18 was 220 mm. In addition, the folding roll 17 was provided so that the contact length between the reinforcing fiber sheet 1a and the member 18 was 25 mm. Note that a free roll having the same material, surface roughness, cross-sectional shape, and diameter as the member 18 was used as the folding roll 17. Note that the surface roughness of the member 18 was measured by using a Mitutoyo-made surface roughness measuring device (SJ-310) with a maximum height Rz measured according to JIS B0601 (2001).

<Coating part>
As the application unit, an application unit of the application unit 20c type shown in FIG. 7 is used, and the application unit 20c uses a stainless steel block for the wall members 21e and 21f that form the liquid reservoir 22 and the constriction 23. Stainless steel plates were used for the side plate members 24a and 24b. In order to further heat the matrix resin, a plate heater was attached to the outer periphery of the wall members 21e, 21f and the side plate members 24a, 24b, so that the temperature and viscosity of the matrix resin could be adjusted while measuring the temperature with a thermocouple. . In addition, the running direction of the reinforcing fiber sheet in the liquid reservoir is vertically downward, and the liquid reservoir has a two-stage tapered shape. The first-stage taper has an opening angle of 17 ° and a taper height (ie, H) of 100 mm. The opening angle of the second-stage taper was 7 °. Further, as a width regulating mechanism, a plate-shaped bush 27 adapted to the inner shape of the application portion as shown in FIG. 5 was provided, L2 was set to 300 mm, and the gap D of the constricted portion was set to 0.2 mm. In addition, the outside of the stenosis portion was closed off from the bush so that the matrix resin did not leak from the stenosis portion exit.

  Hereinafter, details of the present embodiment will be described.

<Reinforcing fiber>
For the preparation of the prepreg, 56 yarns of carbon fibers ("Torayca (registered trademark)" T800S (24K) manufactured by Toray) were used as reinforcing fibers.

<Matrix resin>
Matrix resin A (thermosetting epoxy resin composition):
It is a mixture of an epoxy resin (a mixture of an aromatic amine type epoxy resin and a bisphenol type epoxy resin), a curing agent (diaminodiphenyl sulfone), and a polyether sulfone. The viscosity of this thermosetting epoxy resin 1 was measured using ARES-G2 manufactured by TA Instruments at a measurement frequency of 0.5 Hz and a heating rate of 1.5 ° C./min, and was 15 Pa · s at 90 ° C. . In this embodiment, the matrix resin A heated to 90 ° C. was used.

<Release sheet>
Release paper having a width of 350 mm was used as the release sheet.

<Transport speed>
The running speed of the reinforcing fiber sheet and the prepreg in this example was 20 m / min.

<Evaluation>
Each evaluation was performed as shown below, and “○” and “△” were passed, and “×” was rejected.

<Yarn cracking of reinforced fiber sheet before matrix resin enters>
The yarn cracking of the reinforcing fiber sheet before the matrix resin enters is determined by photographing the widthwise state of the reinforcing fiber sheet when the reinforcing fiber sheet lands on the matrix resin in the application section from the direction of U shown in FIG. did. More specifically, the application was started, and the reinforcing fiber sheet to be applied to the matrix resin in the application section was photographed for 5 minutes with a moving image at a transport speed of 20 m / min. The captured moving images were taken as still images at intervals of 10 seconds, and 30 images were obtained. The width of the yarn crack of the reinforcing fiber sheet was measured from the image. The obtained image was printed, the width of the reinforcing fiber sheet and the width of the yarn crack was measured with a vernier caliper, and the width of the yarn crack when the total width of the reinforcing fiber sheet was 300 mm was calculated. When the maximum yarn crack width obtained from the image was less than 1 mm, it was evaluated as “○”, when it was 1 mm or more and less than 2 mm, “Δ”, and when it was 2 mm or more, it was “X”.

<Yarn cracking of prepreg>
As for the yarn cracking of the prepreg, the obtained prepreg was unwound by 10 m, and the maximum width of the yarn cracking portion having no reinforcing fiber was measured with a vernier caliper. When the yarn crack was less than 2 mm, it was evaluated as “○”, and when it was 2 mm or more, it was evaluated as “X”.

<Fluff wrapped around the part>
“○” indicates that the member that comes into contact with the reinforcing fiber sheet has no visible fluff, and “△” indicates that the member has fluff but can be continuously applied for 30 minutes or more. Was adhered to the reinforcing fiber sheet and brought to the application section, causing thread clogging, and it was difficult to continue application.

[Example 1]
A reinforcing fiber is drawn out from a reinforcing fiber bobbin hung on a creel, and a reinforcing fiber arranging device is used to arrange reinforcing fiber 56 yarns in the width direction to form a reinforcing fiber sheet. After applying the matrix resin A to give a release sheet, the release sheet was peeled off on only one side, and the prepreg / release sheet (sheet-like integrated body) was wound up. When the yarn cracking of the reinforcing fiber sheet before the matrix resin intrusion was evaluated, "で" was passed when the length was less than 1 mm, and "O" was passed when the prepreg was less than 2 mm. Fuzz wrapping around the member was not visually observed, and was evaluated as "O".

[Example 2]
A prepreg / release sheet (sheet-like integrated body) was wound in the same manner as in Example 1 except that the surface roughness of the member to be brought into contact with the reinforcing fiber sheet was 25 μm. When the yarn cracking of the reinforcing fiber sheet before the matrix resin intrusion was evaluated, if it was 1 mm or more and less than 2 mm, the result was evaluated as “△”, and the yarn crack of the prepreg was less than 2 mm, and was evaluated as “○”. Although fluff wrapping was observed on the member, continuous application for 30 minutes or more was possible, and the test was evaluated as “Δ”.

[Example 3]
The diameter of the free roll of the member that comes into contact with the reinforcing fiber sheet is changed to 200 mm, and a direction changing roll is installed so that the contact angle α between the reinforcing fiber sheet and the free roll becomes 143 °, and the contact length between the reinforcing fiber sheet and the member The prepreg / release sheet (sheet-like integrated material) was wound up in the same manner as in Example 1 except that the thickness was changed to 250 mm. When the yarn cracking of the reinforcing fiber sheet before the matrix resin intrusion was evaluated, "で" was passed when the length was less than 1 mm, and "O" was passed when the prepreg was less than 2 mm. Although fluff wrapping was observed on the member, continuous application for 30 minutes or more was possible, and the test was evaluated as “Δ”.

  Examples 1 to 3 show that by setting the surface roughness of the member that comes into contact with the reinforcing fiber sheet and the contact length with the member in an appropriate range, it is possible to suppress the fluff winding around the member.

[Example 4]
A prepreg / release sheet (sheet) was formed in the same manner as in Example 1 except that the member in contact with the reinforcing fiber sheet was changed from a free roll to a driving roll, and the driving roll was rotated so as to be at the same speed as the conveying speed of the reinforcing fiber sheet. Was wound up. When the yarn cracking of the reinforcing fiber sheet before the matrix resin intrusion was evaluated, "で" was passed when the length was less than 1 mm, and "O" was passed when the prepreg was less than 2 mm. Fuzz wrapping around the member was not visually observed, and was evaluated as "O".

[Example 5]
A prepreg / release sheet (sheet-like integrated body) was wound up in the same manner as in Example 1 except that the member in contact with the reinforcing fiber sheet was changed from a free roll to a fixed bar. When the yarn cracking of the reinforcing fiber sheet before the matrix resin intrusion was evaluated, "で" was passed when the length was less than 1 mm, and "O" was passed when the prepreg was less than 2 mm. Fuzz wrapping around the member was not visually observed, and was evaluated as "O".

[Comparative Example 1]
A prepreg / release sheet (sheet-like integrated material) was wound in the same manner as in Example 1 except that the distance E from the matrix resin liquid surface 27 of the application section 20 to the lower end 19 of the member 18 was set to 700 mm. When yarn cracking of the reinforcing fiber sheet before matrix resin intrusion was evaluated, it was rejected as "x" at 2 mm or more, and failed as "x" at 2 mm or more at prepreg.

  From Example 1 and Comparative Example 1, the distance E from the liquid surface 27 of the matrix resin to the lower end 19 of the member 18 is set to an appropriate distance in order to suppress the yarn breakage of the reinforcing fiber sheet and obtain a high-quality prepreg. It turned out to be necessary.

  When the degree of impregnation of the prepregs obtained in Examples 1 to 5 was evaluated by a peeling method, the impregnation rate was 50% or more. The impregnation rate by the peeling method is as follows. The collected prepreg is sandwiched between adhesive tapes, peeled off, and the reinforcing fiber to which the matrix resin is attached and the reinforcing fiber to which the matrix resin is not attached are separated. Calculated from the ratio of the mass of the reinforcing fiber to which the matrix resin adhered to the mass of

  The prepregs obtained in Examples 1 to 5 were slit to obtain a prepreg tape having a width of 7 mm. Since the impregnation of these prepreg tapes was sufficiently advanced, the adhesion of the resin to the cutter blade of the slitter was small.

Further, six layers of the prepregs obtained in Examples 1 to 5 were laminated, and cured at 180 ° C. for 6 hours at 6 kgf / cm ² (0.588 MPa) using an autoclave to obtain CFRP. The tensile strength is about 2.9 GPa, and the CFRP obtained by laminating and curing prepregs prepared by a conventional hot melt method using carbon fiber and matrix resin A in the same manner has the same tensile strength as about 2.9 GPa. It was about. The CFRP tensile strength was measured in the same manner as in WO2011 / 118106, and the value obtained by standardizing the volume% of the reinforcing fibers in the prepreg to 56.5% was used.

  The matrix resin-impregnated reinforced fiber sheet obtained by the production method of the present invention can be used as an FRP typified by CFRP, such as structural materials and interior materials for aerospace applications, automobiles, trains and ships, pressure vessels, industrial materials applications, and sports. It can be widely used for materials, medical equipment, housing, civil engineering and construction.

REFERENCE SIGNS LIST 1 reinforced fiber 1a reinforced fiber sheet 1b matrix resin impregnated reinforced fiber sheet 2 matrix resin 3 release sheet 11 creel 12 arranging device 13, 14 transport roll 15 winding device 16 release sheet supply device 17 direction changing roll 18 member 19 lower end of member 20 Coating section 20b Coating section 20c of another embodiment Coating section 20d of another embodiment Coating section 20e of another embodiment Coating sections 21a, 21b of another embodiment Wall members 21c, 21d Wall members 21e of different shapes , 21f Differently shaped wall members 21g, 21h Differently shaped wall members 21i, 21j Differently shaped wall members 22 Liquid reservoir 22a Region 22b of the liquid reservoir where the cross-sectional area is continuously reduced. A region 22c in which the cross-sectional area does not decrease 22c A region 23 in the liquid reservoir where the cross-sectional area decreases intermittently 4b Side plate member 25 Outlet 26 Gap 27 Liquid surface 27 of matrix resin 2 stored in coating section
28 The point where the reinforcing fiber sheet 1a comes into contact with the member 18 29 The point where the reinforcing fiber sheet 1a separates from the member 18 The application portions 31a and 31b of another embodiment different from the present invention The wall member 32 of another embodiment different from the present invention Liquid reservoir 33 of another embodiment different from the present invention Regions 35a, 35b, and 35c in which the cross-sectional area is intermittently reduced among liquid reservoirs of another embodiment of the present invention Bar 100 Coating device B Liquid reservoir The depth C of the liquid reservoir 22 to the upper liquid surface D The gap of the constriction E The distance G from the upper end of the wall member of the application unit to the lower end of the member 18 The position H for regulating the width H The cross-sectional area of the liquid reservoir 22 is Continuously decreasing vertical height L Width R, Ra, Rb of liquid reservoir 22 Swirling flow T Circulating flow U Photographing direction W of reinforcing fiber sheet W of matrix resin impregnated reinforcing fiber sheet 1b measured immediately below constriction 23 Width Y constriction 3 in the running direction of the width Z reinforcing fiber sheet 1a (vertically downward)
θ Opening angle of taper portion α Contact angle between reinforcing fiber sheet and member 411 Creel 412 Reinforcing fiber bobbin 413 Direction changing guide 414 Reinforcing fiber bundle 415 Reinforcing fiber arrangement device 416 Reinforcing fiber sheet 417 Widening device 418 Smoothing device 419 Turning roller 420 Reinforcing fiber preheating device 421 Direction change roll 422 Member 430 Coating section 441 Direction change roll 442 Release sheet (upper) supply device 443 Release sheet (lower) supply device 444 High tension take-up device 445 Direction change roll 446 Release sheet 447 Laminating roll 448 High tension take-up device 449 High tension take-off S-shaped roll 450 Additional impregnating device 451 Hot plate 452 Heating nip roll 453 Simple additional impregnating device 454 Heating nip roll 455 Heating S-shaped roll 456 Contact roll 461 Cooling device 462 Pulling device 63 release sheet (upper) winding device 464 winder 471 prepreg (matrix resin-impregnated reinforcing fiber sheet)
472 Pre-preg / release sheet (sheet-like integrated product)

Claims (12)

  A method for producing a prepreg in which a reinforcing fiber sheet in which reinforcing fibers are arranged in one direction is passed substantially vertically downward inside an application section in which a matrix resin is stored, and the matrix resin is applied to the reinforcing fiber sheet. The application unit includes a liquid reservoir and a constricted portion that are communicated with each other, the liquid reservoir has a portion having a continuously decreasing cross-sectional area along the running direction of the reinforcing fiber sheet, and the constricted portion is The reinforcing fiber sheet is brought into contact with a member having a slit-shaped cross section and having a cross-sectional area smaller than the upper surface of the liquid pool portion and provided at a position of 1 mm or more and 300 mm or less from the liquid surface of the matrix resin stored in the coating portion. A method of manufacturing a prepreg that runs while running.   The method for producing a prepreg according to claim 1, wherein the member has a surface roughness of 1 µm or more and 20 µm or less.   The method for producing a prepreg according to claim 1 or 2, wherein a contact length between the reinforcing fiber sheet and the member is 5 mm or more and 200 mm or less.   The method for producing a prepreg according to claim 1, wherein the member is a fixed bar.   The method for producing a prepreg according to claim 1, wherein the member is a free roll.   The method for producing a prepreg according to claim 1, wherein the member is a drive roll.   The relationship between the width L (mm) of the lower part of the liquid pool in the arrangement direction of the reinforcing fibers and the width W (mm) of the reinforcing fiber sheet immediately below the constriction satisfies L ≦ W + 10. A method for producing a prepreg according to any one of the above.   A width regulating mechanism for regulating the width of the reinforcing fiber sheet is provided in the liquid reservoir. The width W (mm) of the reinforcing fiber sheet immediately below the constriction and the width L2 regulated by the width regulating mechanism at the lower end of the width regulating mechanism. The method for producing a prepreg according to claim 1, wherein a relationship with (mm) satisfies L2 ≦ W + 10.   The method for producing a prepreg according to any one of claims 1 to 8, wherein a vertical height of a portion of the liquid reservoir where a cross-sectional area is continuously reduced is 10 mm or more.   A method for producing a prepreg tape that slits a prepreg obtained by the method for producing a prepreg according to claim 1.   A method for producing a fiber-reinforced composite material, comprising curing a prepreg obtained by the method for producing a prepreg according to claim 1 or a prepreg tape obtained by a method for producing a prepreg tape according to claim 10.   A prepreg manufacturing apparatus having a traveling mechanism for causing a reinforcing fiber sheet to travel substantially vertically downward, and a coating mechanism for applying a matrix resin to the reinforcing fiber sheet to obtain a prepreg, wherein the coating mechanism includes a matrix resin inside. Further comprising a liquid reservoir and a constricted portion which are communicated with each other, and the liquid reservoir has a portion whose cross-sectional area decreases continuously along the running direction of the sheet-shaped reinforcing fiber bundle. The constricted portion has a slit-shaped cross section and a cross-sectional area smaller than the upper surface of the liquid reservoir portion, and is strengthened at a position within 1 mm or more and 300 mm or less from the liquid surface of the matrix resin stored in the application portion. An apparatus for producing a prepreg, comprising a member for contacting a fiber sheet.

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