JP2004162055A - Method for producing prepreg and apparatus for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a prepreg having no squeezing-out of a resin, nor uneveness in a basis weight of the resin, caused by heating nip rolls, nor defects, such as coarseness and fluffs. <P>SOLUTION: This method for producing the prepreg comprises giving reinforcing fiber bundles aligned in one direction a tension of 0.2-7 N per 1,000 filaments of the fibers, pressing and contacting the reinforcing fibers having a sheetlike form with each roll of a heating metallic roll line composed of two or more heating metallic rolls at a contact angle of 30-210°, and nipping the fibers on at least one heating metallic roll of the heating metallic roll line by a nipping metallic roll, so as to impregnate the sheetlike reinforcing fibers with a thermosetting resin. <P>COPYRIGHT: (C)2004,JPO

Description

  The present invention relates to a prepreg manufacturing method and a manufacturing apparatus that can be used for sports / leisure applications, aerospace applications, general industrial applications, and the like.

  Fiber reinforced plastic members made by curing a prepreg in which a reinforced fiber bundle is impregnated with a thermosetting resin are lightweight and have excellent mechanical strength characteristics, so they are used in sports applications such as fishing rods and golf shafts, and in aerospace. Widely used in applications, general industrial applications, etc.

When a prepreg is used for various members, if there is an unimpregnated portion of the resin in the prepreg layer, voids are likely to remain even when formed into a molded product, which not only lowers the mechanical strength characteristics but also lowers the molding surface quality. It also leads to a decline. Therefore, although with less unimpregnated portion of the resin in the prepreg layer is required, in particular relatively thick varieties and fiber basis weight fiber basis weight between 150 and 400 / m ² about an approximately 75~150g / m ² Also, in a variety having a fiber content exceeding 70% by weight, it was sometimes difficult to sufficiently impregnate the inside of the reinforcing fiber layer with the resin.

  The method for producing prepregs is classified into two methods: a wet method in which a resin is dissolved in a solvent to lower the viscosity to impregnate the reinforcing fibers, and a hot melt method in which the resin is heated to lower the viscosity to impregnate the reinforcing fibers. . Of these, the wet method requires a separate step of removing volatile solvents after impregnating the resin, which not only increases the manufacturing cost, but also leaves the solvent in the prepreg product and adversely affects the molding. And the working environment deteriorates. On the other hand, the hot melt method is advantageous from various points, such as no need to remove the solvent and a relatively good working environment. In the hot melt method, a bundle of reinforcing fibers with a certain tension is aligned, expanded to the required width with a bar, etc. to form a sheet, sandwiched from above and below with release paper coated with a thermosetting resin, and the progress of the reinforcing fibers A method of impregnating a reinforcing fiber with a thermosetting resin by nipping with several pairs of heated metal rolls installed at substantially the same height in the direction (for example, see Patent Document 1), It is known to adjust the nip pressure of the nip pressure (for example, see Patent Document 2). However, in these methods, since the nip pressure is a linear pressure, it is necessary to increase the number of nip rolls in order to obtain a sufficient impregnating property. When the nip pressure is increased to increase the pressure, the excess thermosetting resin protrudes from the side of the sheet-shaped reinforcing fiber bundle and the resin weight in the prepreg decreases, and the protruding resin contaminates the heating roll, resulting in processability. And the workability deteriorated. Furthermore, there is a limit in terms of the resin composition and its curing characteristics in order to reduce the viscosity and improve the impregnation property by heating the resin, and it has been difficult to completely impregnate the resin.

Further, there is disclosed a method of producing a prepreg in which a reinforcing fiber is impregnated with a thermosetting resin by passing the reinforcing fiber through a curved surface while being combined with a thermosetting resin under tension (for example, Patent Document 3 or 4), in order to spread or form a sheet on a substrate having a curved surface on which impregnation is performed, when a prepreg is produced using a reinforcing fiber bundle containing about 12,000 to 48,000 filaments per strand, There was a problem that the openings were not sufficiently widened to cause openings.
JP-A-2000-309021 (page 3) Tokuhei 6-98627 (pages 1-2) JP-A-59-184614 (page 3) Tokuhei 4-24209 (page 4)

  An object of the present invention is to provide a method and an apparatus for producing a prepreg which is excellent in impregnation property and has no openings or fluff defects mainly in a hot melt method.

  In order to achieve the above object, the present invention applies a tension of 0.2 to 7 N per 1000 filaments to a reinforcing fiber bundle aligned in one direction, and comprises a heating metal roll group including at least two or more heating metal rolls. This is a method for producing a prepreg in which a reinforcing fiber bundle is impregnated with a thermosetting resin by being pressed against each roll at a contact angle of 30 to 210 ° and nipped by a metal roll on at least one heated metal roll.

  Further, a prepreg manufacturing apparatus having a means for applying tension to the reinforcing fiber bundle, a resin-coated film supply means, a resin impregnating means for contacting the resin-coated film with the reinforcing fiber bundle and impregnating the resin, and a take-off means for withdrawing the prepreg. A heating metal roll group in which the resin impregnation means is arranged so that the resin-coated film and the reinforcing fiber bundle are pressed against each other at a predetermined contact angle; and a reinforcing fiber bundle on at least one heating metal roll of the heating metal roll group. And a nip metal roll for nipping a resin-coated film.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the stable prepreg manufacturing method which is excellent in impregnation property, and has neither an opening nor a fluff defect mainly in a hot-melt method.

  In the production method of the present invention, a tension of 0.2 to 7 N per 1,000 filaments is applied to the reinforcing fiber bundle. If the tension of the reinforcing fiber bundle is less than 0.2 N per 1000 filaments, the alignment (linearity) of the reinforcing fiber bundle is poor, the mesh becomes open in the prepreg, and the smoothness deteriorates due to the overlapping of the reinforcing fiber bundle. There is. On the other hand, when the tension of the reinforcing fiber bundle exceeds 7 N per 1000 filaments, problems such as addition of a nip roll just to pull the high tension reinforcing fiber bundle and an increase in equipment cost due to reinforcement of the winder occur.

  The means for applying tension is not particularly limited. For example, the tension can be appropriately applied by a tension applying means including a free roll group provided with a powder brake. Specifically, a free roll group in which about 2 to 10 free rolls having a diameter of about 20 to 200 mm are combined and a powder brake are connected with a chain belt or the like, and the braking force of the powder brake is transmitted to the free roll group. When the reinforcing fiber bundle rotates together with the free roll, a tension force can be applied without rubbing the reinforcing fiber bundle by the torque force generated in the free roll group by the powder brake. Here, the free roll of the tension applying means is preferably made of a metal having a rigidity not to be deflected by the tension when the tension is applied to the reinforcing fiber bundle, and a hard steel, a mild steel and other special steels are appropriately used. Can be used. Further, in order to prevent winding of the reinforcing fiber bundle around the roll, it is preferable that the roll surface is subjected to satin finish. The satin roughness can be appropriately used depending on the type and quality of the reinforcing fiber bundle to be used, but a roughness of about 3 to 20 S is preferably used.

In addition, it is preferable that the reinforcing fiber bundle aligned in one direction is widened in advance as necessary before applying tension, so as to form a so-called sheet-like reinforcing fiber. In particular, when a prepreg is manufactured using a reinforcing fiber bundle containing about 12,000 to 48,000 filaments per strand, the fiber weight per unit area (hereinafter, referred to as fiber weight) is 150 g / m2 by widening in advance. ^{Even with} a prepreg of ² or less, openings can be prevented. There is no particular limitation on the means for widening the reinforcing fiber bundle, a method of widening by rubbing with a rubbing roll, a method of widening by vibrating with a vibrating roll, a method of widening by hitting with a beater, a widening by air flow And the like.

  In the method for producing a prepreg of the present invention, a reinforcing fiber bundle (including a sheet-like reinforcing fiber, the same applies hereinafter) is pressed against each roll of a heating metal roll group including at least two or more heating metal rolls at a contact angle of 30 to 210 °. Then, the reinforcing fiber bundle is impregnated with a thermosetting resin by nipping with a metal roll on at least one of the heated metal rolls. In the present invention, a so-called resin-coated film obtained by applying a thermosetting resin to release paper or a release film on one or both sides of the reinforcement fiber bundle when passing the reinforcing fiber bundle while making contact with the heated metal roll group. It can be arranged to be in contact with the reinforcing fiber bundle. Thus, the reinforcing fiber bundle is pressed against the heated metal roll via the resin-coated film to impregnate the resin. When the resin-coated film is disposed only on one side, a release paper or a release film on which the thermosetting resin is not applied may be disposed such that the reinforcing fiber bundle is sandwiched between the resin-coated film and the resin-coated film. it can. Hereinafter, a resin-coated film, a release paper or a release film to which no resin is applied are collectively referred to as a resin-coated film or the like.

  Here, the contact angle is an angle (θ) at which the reinforcing fiber bundle 3 is pressed against the heated metal roll 1 as shown in FIG. Such a contact angle can be determined depending on the fiber basis weight and fiber weight content of the prepreg to be produced, and furthermore, the properties of the thermosetting resin used, but it is necessary to be 30 to 210 °, and 60 to 180 °. It is preferable if there is. If the contact angle is less than 30 °, the amount of heat and surface pressure received from the heating roll is insufficient, and the carbon fiber bundle may not be sufficiently impregnated with the resin. On the other hand, if the contact angle exceeds 210 °, as shown in FIG. 3, the process length of the resin-coated film or the like 2 in contact with the heated metal roll 4 b and the process with the resin-coated film or the like not in contact There is a problem that the difference from the length L2 becomes large and wrinkles 8 are formed on the resin-coated film or the like during the process.

  In the production method of the present invention, since at least two or more heated metal rolls are used, both sides of the reinforcing fiber bundle are pressed against the heated metal roll at least once via a resin-coated film or the like. Thereby, the impregnating property of the thermosetting resin into the reinforcing fiber bundle increases, and a better prepreg can be obtained. The number of the heating metal rolls is not particularly limited as long as it is two or more, but it is preferable to provide two to ten, and more preferably three to eight. The diameter of the heating metal roll is not particularly limited, and the diameters of the plurality of heating metal rolls may be different from each other.

  The production method of the present invention impregnates a reinforcing fiber bundle with a thermosetting resin by nipping a reinforcing fiber bundle with another metal roll on at least one of the heating metal roll groups. The metal roll for the nip is preferably a free roll. By using a free roll so as to follow the running speed of the reinforcing fiber bundle or the resin-coated film, the processability of the reinforcing fiber bundle or the resin-coated film is improved, and the deterioration of the prepreg quality due to wrinkling of the resin-coated film is reduced. It is preferable because it can be suppressed. The roll diameter is preferably 25 to 120 mm, more preferably 25 to 80 mm. Such a metal roll for nip nips the reinforcing fiber bundle from the opposite side of the heated metal roll, and in order to obtain uniform impregnation in the width direction, it is important that the nip has high rigidity and does not bend easily. Hard steel, mild steel, and other special steels can be used as appropriate.

  The smaller the diameter of the nip metal roll, the smaller the contact area between the heated metal roll and the nip metal roll, and the greater the linear pressure due to the nip. When there is no carbon fiber or resin-coated film between the rolls, the maximum contact stress σ [Pa] due to the nip between the rolls is expressed by the following equation.

ニップ用金属ロールにかける荷重Ｐ、加熱金属ロールの弾性率Ｅ₁、ニップ用金属ロールの弾性率Ｅ₂、ニップ幅Ｌ、および加熱金属ロールの半径ｒ₁が一定とすれば、ニップ用金属ロールの直径は小さい方が理論上の接触最大応力σが大きくなり、高線圧を得られることから、含浸性に対しては有利であり好ましいが、直径が２５ｍｍ未満ではロールの長手（軸）方向の曲げ剛性が不足することによりたわみが生じ、含浸性にバラツキがでる場合がある。一方、ロール直径が１２０ｍｍを超えると理論上の接触最大応力σが小さくなり、必要な線圧が得られないために含浸性が不足したり、ロールの重量が大きくなることにより脱着時の作業性に劣る場合がある。

If the load P applied to the nip metal roll, the elastic modulus E ₁ of the heated metal roll, the elastic modulus E _{2 of} the nip metal roll, the nip width L, and the radius r ₁ of the heated metal roll are constant, the nip metal roll When the diameter of the roll is smaller, the theoretical maximum contact stress σ becomes larger and a high linear pressure can be obtained, which is advantageous and preferable for impregnation. However, when the diameter is less than 25 mm, the longitudinal (axial) direction of the roll is smaller. Insufficient bending stiffness may cause deflection and impregnation may vary. On the other hand, if the roll diameter exceeds 120 mm, the theoretical maximum contact stress σ becomes small, and the required linear pressure cannot be obtained. May be inferior.

  In the present invention, the heating metal roll group is a drive roll, and a ratio Vr / Vs of a peripheral speed Vr thereof to a running speed Vs of the reinforcing fiber bundle is preferably in a range of 0.8 to 1.2, and 0.95 to 0.95. More preferably, it is in the range of 1.05 to 1.05. When Vr / Vs is in the range of less than 0.8 or more than 1.2, friction occurs between the heated metal roll and the release paper or the release film in contact with the heated metal roll, whereby the tension of the release paper or the release film is reduced. It may become unstable and cause wrinkles or tears of the release paper or release film during the process.

  In the present invention, the group of heated metal rolls is preferably heated to 70 to 150 ° C, and more preferably in the range of 80 to 130 ° C. The heat of the heated metal roll group lowers the viscosity of the thermosetting resin of the resin-coated film and facilitates impregnation of the reinforcing fiber bundle. The temperatures of the rolls of the heated metal roll group do not need to be the same, and may be set to different temperatures depending on the impregnation property, resin characteristics, and other workability. However, if the temperature of each roll is less than 70 ° C., the viscosity of the thermosetting resin may not be sufficiently reduced and impregnation may be poor, and if the temperature of each roll is 150 ° C. or more, the thermosetting resin may be hardened. Inadvertently promoted, there is a case where the handleability of the prepreg is inferior.

  In the present invention, the distance between the surfaces of the heated metal rolls adjacent to the front or rear of the heated metal roll group in the running direction of the reinforcing fiber bundle is preferably 5 to 150 mm, more preferably 10 to 120 mm. . Here, the distance between the heating metal roll surfaces is a distance between adjacent heating metal rolls and the closest distance. Among the rolls of the heating roll group, it is preferable that even one distance between the surfaces of the heated metal rolls falls within the above range, but it is more preferable that all the distances between the surfaces of the heated metal rolls fall within the above range. preferable. Due to the heat of the heated metal roll group, the thermosetting resin of the resin-coated film is reduced in viscosity, but substantially heat is released between the heated metal rolls. If the distance between the front and rear adjacent heated metal roll surfaces is long, the viscosity of the thermosetting resin whose viscosity has been reduced becomes high before reaching the next heated metal roll, and efficient impregnation cannot be performed. That is, if the distance between the front and rear adjacent heated metal roll surfaces exceeds 150 mm, sufficient impregnating properties may not be obtained due to high viscosity of the resin between the rolls. If the distance between the surfaces of the heated metal rolls is less than 5 mm, the workability may be reduced during operations such as thread passing and dirt removal.

  In the present invention, means for preheating the reinforcing fiber bundle together with the resin-coated film or the like immediately before entering the heated metal roll group may be provided. By preheating using a heater or the like, the thermosetting resin before impregnation is appropriately reduced in viscosity, so that the impregnation property is increased and a better prepreg can be obtained. The preheating method is not particularly limited, such as a far-infrared heater, a hot plate, a hot roll, and hot air, but a hot plate or a hot roll is preferably used because it can be uniformly heated. The heating temperature may be a temperature at which the thermosetting resin is reduced in viscosity to some extent immediately before entering the heated metal roll group, and is preferably about 50 to 120 ° C.

  It is preferable that the reinforcing fiber sheet impregnated with the thermosetting resin is cooled to 30 ° C. or lower after passing through the group of heated metal rolls. The reinforcing fiber sheet impregnated with the thermosetting resin is not cooled to 30 ° C. or less after passing through a group of heating rolls, and proceeds to a step of winding on a winder, for example, and the curing reaction is accelerated by the heat of the resin itself. In addition, there is a possibility that the resin properties are adversely affected, or the alignment of the reinforcing fibers is disturbed due to a decrease in the viscosity of the resin due to heat storage, and the quality as a prepreg is significantly reduced. The cooling method is preferable because it can be cooled in a short time by bringing it into contact with a cooling plate set at 5 to 15 ° C.

  The reinforcing fiber bundle used in the present invention is not particularly limited, and carbon fiber, glass fiber, aramid fiber, alumina fiber and the like can be used. Moreover, the number of filaments (the number of single fibers) per fiber bundle in the reinforcing fiber bundle in the present invention is not particularly limited, but is preferably 1,000 to 72,000, more preferably 1,000 to 48,000, and 3,000 to 48,000. Books are more preferred.

  The thermosetting resin used in the present invention is composed of an epoxy resin composition, and preferably contains at least an epoxy resin and a curing agent.

  As such an epoxy resin, for example, bisphenol-type epoxy resin, bisphenol-type epoxy resin such as bisphenol F-type epoxy resin, phenol novolak-type epoxy resin, novolak-type epoxy resin such as cresol-novolak-type epoxy resin, or a combination thereof is preferable. But is not particularly limited.

  As the curing agent used in such an epoxy resin composition, any compound having an active group capable of reacting with an epoxy group can be used, but a compound having an amino group, an acid anhydride group, and an azide group is preferable. Is used. Specifically, various isomers of dicindiamide and diaminodiphenyl sulfone, and aminobenzoic acid esters are preferably used.

  In addition to the epoxy resin and the curing agent, other components such as a polymer compound and organic particles can be appropriately added to the epoxy resin composition according to the purpose.

  Next, an example of the prepreg manufacturing apparatus of the present invention used in the above manufacturing method will be described with reference to FIG.

  The prepreg manufacturing apparatus according to the present invention comprises a tension applying means 15 for reinforcing fiber bundles, resin-coated film supply means 18a and 18b, a resin impregnating means 23 for contacting the reinforcing fiber bundle with the resin-coated film and impregnating the resin, And a heating metal roll group 29 arranged so that the resin impregnating means presses the resin applied films 19a, 19b and the reinforcing fiber bundle 12 at a predetermined contact angle. And a nip metal roll 28 for nipping the reinforcing fiber bundle and the resin-coated film on at least one of the heated metal roll groups.

  Although there is no particular limitation on the tension applying means, the tension can be appropriately applied by a tension applying means comprising a plurality of roll groups connected to the powder brake 17 as shown in FIG. Specifically, a roll group in which about 2 to 10 free rolls 16 having a diameter of about 20 to 200 mm are combined with a powder brake 17 by a chain belt or the like, and the braking force of the powder brake 17 is transmitted to a plurality of roll groups. . Here, the free roll 16 of the tension applying means is preferably made of a metal having rigidity as described above, and the surface of the roll is set to about 3 to 20 S in order to prevent the reinforcing fiber bundle from winding around the roll. It is preferable that the fabric has a satin finish.

  The resin application film supply means 18a, 18b is for attaching and unwinding, for example, a resin application film wound in a roll shape.

  In order to heat the reinforcing fiber bundle sandwiched between the resin coating films 19a and 19b, the heater 22 may be installed before entering the impregnating means, if necessary. The heater 22 is not particularly limited, such as a far-infrared heater, a hot plate, a hot roll, and hot air, but a hot plate or a hot roll is preferable because it can uniformly heat.

  The resin impregnating means for contacting the resin coating film with the reinforcing fiber bundle and impregnating the resin includes a heating metal roll group 29 arranged so as to press the resin coating film and the reinforcing fiber bundle at a predetermined contact angle; A nip metal roll 28 for nipping the reinforcing fiber bundle and the resin-coated film on at least one heated metal roll of the group 29.

  The take-off means 33 for taking out the prepreg comprises a pair or several pairs of take-off nip rolls 32, which can change the rotation speed of the take-up nip rolls 32 in accordance with the production speed of the prepreg. The take-off nip roll 32 is preferably a roll having a metal surface or a rubber surface.

  Further, if necessary, a cooling plate 31 for cooling the prepreg can be provided between the resin impregnating means and the take-off means. Although the cooling plate 31 is not particularly limited, for example, a metal plate having a refrigerant therein is preferable because it has good thermal conductivity. The surface temperature of the cooling plate 31 may be about 5 to 15 ° C.

The present invention is described in more detail by the following examples.
(1) Preparation of resin composition The following materials were mixed in a kneader to obtain a thermosetting resin composition.
Bisphenol A type epoxy resin 20 parts by weight (Epicoat (registered trademark) 828, manufactured by Yuka Shell Epoxy Co., Ltd.)
Bisphenol A type epoxy resin 30 parts by weight (Epicoat 1001, Yuka Shell Epoxy Co., Ltd.)
50 parts by weight of phenol novolak epoxy resin (Epicoat 154, manufactured by Yuka Shell Epoxy Co., Ltd.)
10 parts by weight of polyvinyl formal (Vinilec K (registered trademark), manufactured by Chisso Corporation)
3- (3,4-dichlorophenyl) -1,1-dimethylurea 10 parts by weight (DCMU99, model number, manufactured by Hodogaya Chemical Industry Co., Ltd.)
(2) Preparation of Resin-Coated Film A resin-coated film was prepared by applying the thermosetting resin composition to release paper with a predetermined thickness using a knife coater, and was wound into a roll.

  Incidentally, in the examples, the impregnating property of the obtained prepreg is visually confirmed the wetting condition of the reinforcing fibers in the layer and the surface layer by the resin, and it is preferable that the reinforcing fibers not wetted by the resin have no so-called dry fibers at all. Those having dry fibers in the layer or on the surface were regarded as defective. In order to check the dry fiber in the layer, a prepreg measuring 5 cm in length and 100 cm in width was sandwiched from both sides with an OPP adhesive tape (Nippon Denko Co., Ltd., Damplon Series No. 3201) with the fiber direction as the longitudinal direction. After that, the inside of the prepreg layer was observed by peeling.

Moreover, the fluff of the obtained prepreg was visually observed, and when the length of the long side of the fluff was 10 mm or more, it was regarded as a defect. Further, the openings of the obtained prepreg were visually confirmed, and those having a width of 1 mm or more were regarded as defects.
Example 1 A prepreg was manufactured using the manufacturing process shown in FIG. As the reinforcing fiber bundle, 125 carbon fibers T700SC-12K (manufactured by Toray Industries, Inc .; number of filaments: 12,000, tensile strength: 4,900 MPa, tensile modulus: 230 GPa) were used, and the fiber weight was 100 g / m ² . The fiber weight content was 76%. A plurality of carbon fiber bundles 12 drawn out from the bobbin 11 installed on the creel 10 with a tension of 0.1 N per 1,000 pieces were widened into a 1000 mm wide sheet shape by widening means 13 having rubbing rolls 14.

The reinforcing fiber bundle is tensioned to 2.0 N per 1000 filaments by a tension applying device 15 equipped with two hard steel free rolls 16 and satin-finished 16S and a powder brake 17 (ZKB-20HBN manufactured by Mitsubishi Electric). Was given. It was visually confirmed that there was no occurrence of fluff or thread breakage due to abrasion in the tension applying device portion, and no free roll deflection or carbon fiber winding. The tensioned carbon fiber bundle is sandwiched between a release paper 19a and a resin coating film 19b coated with a thermosetting resin having a basis weight of 32 g / m ² on one side, and is brought into contact with a heater 22 set at a surface temperature of 100 ° C. for preliminary use. Heated. The heater 22 was a hot plate. The carbon fiber bundle sandwiched between the release paper and the thermosetting resin and preheated is moved at a speed of 3.0 m / min while running at 180 ° to the heated metal roll 24 and at 100 ° to the heated metal rolls 25 and 26. The heating metal roll 27 was pressed against the heating metal roll 27 at a contact angle of 180 °, and a load of 1.5 kN was applied on the heating metal roll 27 with a metal nip metal roll having a diameter of 40 mm and an elastic modulus of 21.6 GPa. By nip over a width of 1000 mm at a linear pressure of 8 MPa, the carbon fiber bundle was impregnated with a thermosetting resin to obtain a prepreg. The heating temperature of the heating metal rolls 24, 25, 26, and 27 was 110 ° C., the diameter was 250 mm, the elastic modulus was 21.6 GPa, and the distance between the heating metal roll surfaces was 60 mm. Further, the peripheral speed Vr of the heated metal rolls 24, 25, 26, 27 was 3.0 m / min, and the ratio Vr / Vs to the traveling speed Vs of the carbon fiber bundle was 1.0. At this time, there was no protrusion of the resin onto the heated metal roll, and it was confirmed that there was no contamination by the protrusion resin. After the impregnated prepreg was cooled to 25 ° C. by the cooling plate 31 set at 10 ° C., the release paper 34 on one side was peeled off and wound up as a product roll 36 on a winder. As shown in Table 1, the obtained prepreg had good impregnating properties and good quality without fuzz defects or opening defects.
(Comparative Example 1) A prepreg was obtained in the same manner as in Example 1 except that the nip by the nip metal roll 28 was not performed. As shown in Table 2, the obtained prepreg was inferior in quality because dry fibers were conspicuous in the surface layer due to insufficient impregnation.
(Comparative Example 2) Except that the setting of the tension applying device 15 equipped with the powder brake 17 (ZKB-20HBN manufactured by Mitsubishi Electric) shown in FIG. 1 was adjusted, and a tension of 0.15 N was applied per 1000 carbon fiber filaments. A prepreg was obtained in the same manner as in Example 1. As shown in Table 2, the obtained prepreg was poor in quality, with dry fibers remaining in the layer and in the surface layer and having many aperture defects.
(Embodiment 2) The distance between the surfaces of the heating metal rolls 24, 25, 26 and 27 shown in FIG. 1 was 250 mm, 150 ° for the heating metal roll 24, and 70 ° for the heating metal rolls 25 and 26. A prepreg was obtained in the same manner as in Example 1 except that the heated metal roll 27 was contacted at a contact angle of 150 °. As shown in Table 1, the obtained prepreg had less resin-impregnated portions in the layer than in Example 1 due to the effect of lowering the resin temperature between the heated metal rolls (higher viscosity of the resin). However, it was not at a level that would pose a problem in terms of handleability and molded article strength. For complete impregnation, it was necessary to reduce the traveling speed of the carbon fiber bundle to 1 m / min, and the time required for production was longer than in Example 1, but there was no problem with the obtained quality.
(Example 3) A prepreg was manufactured using the manufacturing process shown in FIG. As the reinforcing fiber, 109 carbon fibers T700SC-24K (manufactured by Toray Industries, Inc .; number of filaments: 24,000, tensile strength: 4900 MPa, tensile modulus: 230 GPa) were used, and the fiber weight was 175 g / m ² . Further, resin-coated films having a resin weight of 32 g / m ^{2 obtained} by applying a thermosetting resin to release paper were used as 19a and 19b, and the fiber weight content was 73%. Further, a prepreg was obtained in the same manner as in Example 1 except that a load of 2.5 kN was applied by the nip metal roll 28 and nip was performed at a linear pressure of 33.3 MPa. As shown in Table 1, the obtained prepreg had good impregnating properties and good quality with few fuzz defects and opening defects.
(Comparative Example 3) By performing the process shown in FIG. 4 between the heater 22 and the cooling plate 31 shown in FIG. 1, the contact angle between each roll of the group of heated metal rolls and the yarn is substantially reduced to 0 °. Except that three hard metal nip metal rolls 28 each having a diameter of 40 mm and a modulus of elasticity of 21.6 GPa were used, and a load of 7.4 kN was applied to each of the nip metal rolls at a linear pressure of 57.2 MPa per nip metal roll. A prepreg was obtained in the same manner as in Example 3. Due to the high linear pressure, the excess thermosetting resin protrudes from the side of the sheet-like reinforcing fiber, the resin metal adheres to the heated metal roll 35, and the workability deteriorates. The obtained prepreg is shown in Table 2. As shown, the dry fiber remained in the layer and the quality was poor with many fluff defects.
Example 4 A prepreg was manufactured using the manufacturing process shown in FIG. As the reinforcing fiber, 91 carbon fibers S300C-48K (48000 filaments, tensile strength 3630 MPa, tensile modulus 230 GPa) manufactured by Toray Industries, Inc. were used, and the fiber weight was 300 g / m ² . In addition, resin-coated films having a resin weight of 74 g / m ^{2 obtained} by applying a thermosetting resin to release paper were used as 19a and 19b, and the fiber weight content was 67%. Further, a prepreg was obtained in the same manner as in Example 1 except that a load of 2.9 kN was applied by a nip metal roll 28 made of hard steel having a diameter of 40 mm and an elastic modulus of 21.6 GPa, and nip was performed at a linear pressure of 35.8 MPa. Was. As shown in Table 1, the obtained prepreg had good impregnating properties and good quality with few fuzz defects and opening defects.
(Comparative Example 4) The process from the heater 22 to the cooling plate 31 shown in FIG. 1 was performed as shown in FIG. 4, the diameter of the nip metal roll 28 was 20 mm, and the nip metal roll 28 was 2.9 kN. And a prepreg was obtained in the same manner as in Example 4 except that the nip was nipped at a linear pressure of 48.4 MPa. Insufficient bending stiffness in the axial direction of the nip metal roll causes deflection of the nip metal roll, and the resulting prepreg has a non-uniform impregnating property in the width direction as shown in Table 2 and poor quality of dry fiber remaining. It was something.

It is a side view which shows an example of the manufacturing process of the prepreg of this invention. It is a figure which shows the contact angle with a heating metal roll. It is a side view which shows a mode that wrinkles generate | occur | produce in a resin coating film etc. by the process length difference of the resin coating film etc. which generate | occur | produced in the heating metal roll. It is a side view which shows the manufacturing process of the conventional prepreg.

Explanation of reference numerals

REFERENCE SIGNS LIST 1 heating metal roll 2 resin coating film 3 reinforcing fiber bundles 4 a, 4 b heating metal roll 5 resin coating film in contact with heating metal roll 4 b 6 resin coating film 7 in non-contact with heating metal roll 4 b Fiber bundle 8 Wrinkles of resin applied film generated during the process 9 Guide roll 10 Creel 11 Bobbin 12 Carbon fiber bundle 13 Widening means 14 Scraping roll 15 Tension applying means 16 Free roll 17 Powder brake 18a Resin applied film etc. (resin applied film , Release film, release paper) supply means 18b supply means 19a, such as resin coating film, release means 19a, release paper or release film or resin coating film 19b, resin coating films 20, 21, guide rolls 22, heaters 23, resin impregnation means 24, 25, 26, 27 Heating metal roll 28 Metal row for nip 29 taking over heated metal rolls 30 guard rolls 31 cooling plate 32 nip rolls 33 take-up means 34 collecting the release paper or recovered film 35 guide roll 36 product roll 37 heated metal roll

Claims (12)

A tension of 0.2 to 7 N per 1000 filaments is applied to the reinforcing fiber bundles aligned in one direction, and a contact angle of 30 to 210 ° is applied to each roll of a heated metal roll group including at least two or more heated metal rolls. A method for producing a prepreg in which a reinforcing fiber bundle is impregnated with a thermosetting resin by being pressed and nipped with a metal roll on at least one heated metal roll. The method for producing a prepreg according to claim 1, wherein the reinforcing fiber bundle is pressed against the heated metal roll at least once on both sides. The method for producing a prepreg according to claim 1 or 2, wherein the metal roll for nip is a free roll, and the roll diameter is 25 to 120 mm. The heating metal roll group is a drive roll, and the ratio Vr / Vs of the peripheral speed Vr and the running speed Vs of the reinforcing fiber bundle is in the range of 0.8 to 1.2. A method for producing the prepreg according to the above. The method for producing a prepreg according to any one of claims 1 to 4, wherein the heated metal roll group is heated to 70 to 150C. The method for producing a prepreg according to any one of claims 1 to 5, wherein a distance between front surfaces of the heating metal rolls adjacent to the front or rear of the heating metal roll group in the running direction of the reinforcing fiber bundle is 5 to 150 mm. The method for producing a prepreg according to any one of claims 1 to 6, wherein the reinforcing fiber bundle is preheated together with the resin-coated film before the reinforcing fiber bundle comes into contact with the heated metal roll group. After passing through the heating roll group, the reinforcing fiber bundle impregnated with the resin is brought into contact with a cooling plate at 5 to 15 ° C, cooled to 30 ° C or less, and wound by a winder. Method for producing prepreg. A prepreg manufacturing apparatus comprising: means for applying tension to a reinforcing fiber bundle; means for supplying a resin-coated film; means for contacting a resin-coated film with the reinforcing fiber bundle to impregnate a resin; A heating metal roll group arranged so that the resin impregnating means presses the resin-coated film and the reinforcing fiber bundle at a predetermined contact angle, and a reinforcing fiber bundle on at least one of the heating metal rolls of the heating metal roll group; A prepreg manufacturing apparatus comprising: a nip metal roll for nipping a resin-coated film. The prepreg manufacturing apparatus according to claim 9, wherein the tension applying means includes a plurality of roll groups connected to a powder brake. The prepreg manufacturing apparatus according to claim 9 or 10, further comprising a heater between the resin-coated film supply means and the impregnation means for heating the resin-coated film and the reinforcing fiber bundle. The prepreg manufacturing apparatus according to any one of claims 9 to 11, further comprising a cooling plate for cooling the prepreg between the resin impregnating means and the take-off means.

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