JP2009292002A - Method of manufacturing fiber-reinforced plastics - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a high-quality level/high-quality fiber-reinforced plastics which can stably reveal excellent dynamic properties, low dispersion nature and outstanding dimensional stability, when the fiber-reinforced plastics is made using a base material with successful fluidity and molding follow-up performance to complicated shapes. <P>SOLUTION: (1) The fiber-reinforced plastics with a stepped part of differing plate thickness are laminated in such a way that a thick-walled part with a large number of laminations of prepreg base materials, a thin-walled part with a small number of laminations of prepreg base materials and a stepped part serving as a boundary between the thick-walled part and the thin-walled part, can be formed. Thus, a planar laminated form with a differing plate thickness, is obtained. (2) The stepped part of the laminated form is arranged by positioning it in the stepped part formed in a molding die so that the former can be registered with the latter. Further, the elongated laminated form is packed in the molding die. (3) The fiber-reinforced plastics are unloaded from the molding die and thereby, the molding process is completed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  In the present invention, when a base material having good fluidity and molding followability is used as a fiber reinforced plastic, excellent mechanical properties, low variation, and excellent dimensional stability are stably expressed. The present invention relates to a method for producing high-quality and high-quality fiber-reinforced plastic. Such fiber reinforced plastics are particularly suitably used for structural members such as transport equipment such as automobiles and airplanes and sports equipment such as bicycles.

  The demand for fiber reinforced plastics composed of reinforced fibers and matrix resins is increasing year by year because of their high specific strength and specific elastic modulus, excellent mechanical properties, and high functional properties such as chemical resistance.

  As a method for molding fiber reinforced plastic, a semi-cured intermediate base material impregnated with a thermosetting resin is laminated on a continuous reinforcing fiber called a prepreg base material, and heat is applied by heating and pressurizing with a high-temperature and high-pressure kettle. Autoclave molding in which a curable resin is cured and a fiber-reinforced plastic is molded is most commonly performed. The obtained fiber reinforced plastic has excellent mechanical properties because it is a continuous fiber. Further, since the continuous fibers are regularly arranged, it is possible to design the mechanical properties required by the arrangement of the base material, and the variation in the mechanical properties is small. However, there is a problem that it is difficult to form a three-dimensional shape because it is a continuous fiber. In particular, in the case of a complicated three-dimensional shape having a double contour part, when an intermediate base material using continuous fibers is shaped, there are stretches where the surface of the shape cannot be covered, and wrinkles where the intermediate base material remains. Therefore, there is a problem that it is difficult to form with high quality and high quality.

  For such problems, a proposal for forming a C-shaped two-dimensional shape (for example, Patent Document 2) using a laminate (for example, Patent Document 1) obtained by laminating prepreg base materials of continuous fibers is different in plate thickness. There are proposals for forming a step shape (for example, Patent Document 3) and proposals for forming a three-dimensional shape by preheating a laminated body to form a complicated shape (for example, Patent Documents 4 and 5). However, since a continuous fiber prepreg base material is used, it is difficult to form a three-dimensional shape (particularly, a shape having a double contour portion) into a stepped shape having different plate thicknesses.

On the other hand, an intermediate substrate using discontinuous fibers instead of continuous fibers, for example, BMC (bulk molding compound) (for example, Patent Document 6), SMC (sheet molding compound), stampable sheet (for example, Patent Document 7), If an intermediate base material in which bundled discontinuous fibers are dispersed in a matrix resin, such as a base material in which a prepreg is cut (for example, Patent Document 8), a three-dimensional shape having the above-described double contour portion is obtained. However, although it is known that the molding follows, there is a problem that the mechanical properties cannot be improved, and it cannot be applied to a structural member requiring high mechanical properties.
JP 2006-188597 A Japanese Patent Laid-Open No. 2006-312260 JP 2007-230036 A JP 2008-068532 A JP 2008-055609 A Japanese Patent Laid-Open No. 08-118379 JP-A-9-267344 International Publication No. WO2007 / 0135418 Pamphlet

  In view of the background of such prior art, the present invention, when used as a fiber-reinforced plastic using a substrate having good fluidity and molding followability of a complicated shape, has excellent mechanical properties, low variability, excellent Another object of the present invention is to provide a high-quality and high-quality fiber-reinforced plastic that stably exhibits dimensional stability and a method for producing the same.

  The present invention employs the following means in order to solve such problems. That is, a method of producing a fiber reinforced plastic having step portions having different plate thicknesses by press-molding a laminate of a prepreg base material including a reinforced fiber aligned in one direction and a matrix resin. As the prepreg base material, at least the following (1), using a notched prepreg base material in which at least a part of the reinforcing fibers is divided into a length of 10 to 100 mm by a plurality of incisions in a direction crossing the reinforcing fibers. It is a manufacturing method of a fiber reinforced plastic which shape | molds a fiber reinforced plastic through the process of (3) sequentially.

(1) When obtaining a laminate by laminating a plurality of prepreg substrates including at least a cut prepreg substrate, at least a part of the laminate and a thick part having a large number of laminated prepreg substrates, and a prepreg Lamination process for obtaining a flat laminate having different plate thicknesses by laminating so that a thin portion with a small number of base materials and a step portion which is a boundary between the thick portion and the thin portion are formed (2) When the laminate is pressed against a mold and cured or solidified to form a fiber reinforced plastic, the laminate is positioned so that the step portion of the laminate corresponds to the step portion provided in the mold. Forming the mold, and extending at least one of the thick part, the thin part, or the step part of the laminate, and filling each of the thick part, the thin part, and the step part of the mold. (3) From the mold to the fiber Demolding step of taking out the plastics.

  According to the present invention, when a fiber reinforced plastic is used by using a base material having good fluidity and molding followability of a complicated shape, excellent mechanical properties, its low variation, and excellent dimensional stability are stabilized. As a result, a high-quality and high-quality fiber-reinforced plastic can be obtained.

  The method for producing a fiber reinforced plastic according to the present invention produces a fiber reinforced plastic having different plate thicknesses by press-molding a laminate of a prepreg base material including a reinforced fiber and a matrix resin aligned in one direction. The prepreg base material is a cut prepreg base material obtained by dividing at least a part of reinforcing fibers into a length of 10 to 100 mm by a plurality of cuts in a direction crossing the reinforcing fibers, A fiber-reinforced plastic is molded through the steps (1) to (3) described in detail below.

  The fiber reinforced plastic molded by the production method of the present invention has at least a thick portion and a thin portion having different plate thicknesses, and a step portion that is a boundary between them. In order to exhibit the effect of the present invention more highly, it is preferable that the fiber reinforced plastic further has a three-dimensional shape having a double contour portion. In addition, a part of the fiber reinforced plastic may have a rib or a boss. Here, the “fiber reinforced plastic having a double contour portion” in the present invention is a point on the quadratic curved surface when the surface of the fiber reinforced plastic is taken out as a quadric curved surface. Even if such a plane is referred to, a point where an intersection line passing through the point does not become a straight line among intersection lines of the plane and the quadric surface belongs to the double contour part, and at least a part of the double contour part is included. Refers to fiber reinforced plastics. Specifically, a saddle shape, a hemispherical shape, a flat plate having an uneven portion, and the like are applicable, but a flat plate without a step portion, a conical shape, and a cylindrical shape are not applicable. In the present specification, unless otherwise specified, in the term including fibers or fibers (for example, “fiber direction”, etc.), the fibers represent reinforcing fibers. In the present specification, the continuous fiber refers to a reinforcing fiber having a fiber length of 100 mm or more.

  The prepreg base material used in the present invention is a state in which the resin sheet is not completely impregnated between the fibers, in addition to the reinforcing fiber aligned in one direction and the base material in which the reinforcing fiber base material is completely impregnated with resin. And a resin semi-impregnated base material (semi-preg: hereinafter also referred to as semi-impregnated prepreg).

  The incised prepreg base material used in the present invention is composed of a reinforcing fiber and a matrix resin that are aligned in one direction, and at least a part of the reinforcing fibers is formed by a plurality of incisions in a direction across the reinforcing fiber. The thing divided into the length of 100mm is pointed out. The cut portion in which the reinforcing fibers are divided to a length of 10 to 100 mm on the cut prepreg base material corresponds to a region where the base material can be extended in the molding step (2) described later. Therefore, when molding a fiber-reinforced plastic having a complicated shape, the laminated body in the region corresponding to at least one of the thick part, the thin part, or the step part has 10 to 10 reinforcing fibers by cutting on the cut prepreg base material. It is essential that the cut portions divided into 100 mm lengths are stacked.

  Since the reinforced fibers are aligned in one direction in the cut prepreg base material used in the present invention, it is possible to design a molded body having arbitrary mechanical properties by controlling the orientation in the fiber direction. In addition, since at least some of the fibers are divided into a length of 100 mm or less by a plurality of incisions in the direction crossing the fibers, the fibers can flow during molding, particularly in the longitudinal direction of the fibers. Excellent shape following capability. When there is no notch, that is, when only continuous fibers are used, a complicated shape cannot be formed because the fibers do not flow in the fiber longitudinal direction. On the other hand, if the fiber length is less than 10 mm, the fluidity is further improved. However, even if other requirements are satisfied, the high mechanical properties necessary as a structural material cannot be obtained. Considering the relationship between fluidity and mechanical properties, the fiber length needs to be 10 to 100 mm, and more preferably within the range of 20 to 60 mm.

  FIG. 2 is a cross-sectional view showing an example of the flow mechanism of the laminate used in the present invention.

  As shown in FIG. 2 (a), when molding is performed by applying pressure 13 from above the laminate 12 in which the 0 ° cut prepreg base material is sandwiched between 90 ° prepreg base materials, The resin extruded under pressure creates a flow 14 in the direction of 90 °, and the opening 15 of the discontinuous ends 4 of the reinforcing fibers occurs according to the flow. That is, it is not possible to provide a notch in a prepreg base material made of fibers aligned in one direction, and at least some of the reinforcing fibers are laminated with a notched prepreg base material having a length of 10 to 100 mm. Flow in the direction is possible, and molding conformability of complicated shapes is born. As described above, the flow of the reinforcing fiber is preferably an appropriate Vf (fiber volume content) since the flow of the matrix resin is the driving source. That is, Vf is preferably 65% or less because sufficient fluidity can be obtained. Moreover, although fluidity | liquidity improves, so that Vf is low, when Vf is less than 45%, since there exists a possibility that a high mechanical characteristic required for a structural material may not be acquired, it is preferable that Vf is 45% or more. Considering the relationship between fluidity and mechanical properties, it is more preferably in the range of 55-60%.

  The manufacturing method of the fiber reinforced plastic of this invention is shape | molded through the process of at least following (1)-(3) sequentially using the above-mentioned cutting prepreg base material. One of the features of the present invention is that fiber reinforced plastics having step portions having different plate thicknesses can be easily and stably molded.

(1) Laminating step When obtaining a laminate by laminating a plurality of prepreg substrates including at least a cut prepreg substrate, at least a part of the laminate has a thick portion having a large number of laminated prepreg substrates; Lamination is performed so that a thin part with a small number of laminated prepreg base materials and a step part which is a boundary between the thick part and the thin part are formed to obtain a flat laminate having different plate thicknesses.

  FIG. 1 is a perspective view showing an example of a method for producing a fiber-reinforced plastic according to the present invention. For example, as shown in FIG. 1 (c), the fiber reinforced plastic 16 having the step portion 12c and the hemispherical double contour portion 25 in the thick portion 12a and the thin portion 12b is manufactured as follows. The process goes through sequentially.

  First, the flat laminated body 12 is produced by laminating a plurality of prepreg base materials including at least a cut prepreg base material. Conventionally, a prepreg base material is laminated one by one along a mold, and a laminated body having a complicated shape is formed while forming, or the final shape of the fiber-reinforced plastic after molding (the resulting fiber) The shape of the reinforced plastic is simplified and the number of concavities and convexities is reduced or the undulations are reduced. However, in the present invention, the prepreg base material can be formed simply by laminating it into a flat plate, and a laminate can be produced at a lower cost. can do.

  FIG. 3 is a plan view and a cross-sectional view showing an example of a laminate used in the present invention. 3 (a) and 3 (b) show an example in which a cut portion is provided in a part of each laminated body. Each of FIGS. The figure is shown.

  In Fig.3 (a), only the cut prepreg base material into which the fiber was cut | disconnected by the length of 10-100 mm by the incision was used, and the cut prepreg base material 10a cut into the whole surface is laminated | stacked five sheets In addition, two cut prepreg base materials 10a that are cut into the entire surface with a smaller area than the cut prepreg base material 10a, and two further cut prepreg base materials 10a with a smaller area, a total of four layers The example which laminated | stacked is shown. The thick portion 12a is a nine-cut prepreg substrate, the thin portion 12b is a five-cut prepreg substrate, and the step portion 12c is more than five and less than nine, that is, seven cut prepregs. It is formed of a base material. In particular, when manufacturing a fiber-reinforced plastic having a complicated shape having the double contour portion 25, it is preferable to form the cut portion 37 in which only the cut prepreg base material is laminated. In the notch part 37, only the notch prepreg base material which consists only of a fiber of 10-100 mm substantially is laminated | stacked in the thickness direction of the laminated body. Here, “consisting essentially of fibers of 10 to 100 mm” means that 95% or more of the number of reinforcing fibers contained in the region is divided into 10 to 100 mm. Hereinafter, such a region is referred to as a cut portion of the laminate. When molding a fiber-reinforced plastic with a complex shape having the double contour part 25, the cut prepreg base material is easily stretched at the time of molding because the region of the laminate corresponding to the double contour part 25 is the cut part. Can follow a complex shape. When molding a fiber-reinforced plastic with a complex shape having a double contour part, when forming using only a prepreg base material of continuous fibers, create a flat cut pattern that develops the surface shape of the fiber-reinforced plastic, The continuous fiber base material cut with the cut pattern is required to be formed into a complex shape strictly along the mold and repeated for the number of layers to produce a laminate. On the other hand, in the case of molding using the cut prepreg base material according to the present invention, the cut prepreg base material (particularly the cut portion) extends and conforms to a complicated shape. In addition, a double contour part can be formed by molding with a molding die at once using a laminated body that is laminated in a flat shape without being shaped into a complicated shape completely along the shape of the molding die (that is, fiber reinforced plastic after molding) Therefore, a fiber-reinforced plastic can be produced with extremely high efficiency.

  In FIG.3 (b), the notch prepreg base material 10a by which the notch was cut into the whole surface using the notch prepreg base materials 10a and 10b and the continuous fiber prepreg base material 11 for at least a part of this laminated body. Are stacked, and two continuous fiber prepreg substrates 11 having a smaller area than the cut prepreg substrate 10a are stacked, and further cut into a part of the same area as the cut prepreg substrate 10a. The example which laminated | stacked one sheet of the cut prepreg base material 10b into which was put. The thick portion 12a is a total of nine pieces of seven cut prepreg substrates 10a and 10b and two continuous fiber prepreg substrates 11, and the thin portion 12b is seven cut prepreg substrates 10a and 10b. The step portion 12c is formed as a straight line (a plane when the thickness direction of the laminate is taken into consideration). Similarly to FIG. 3A, there is a cut portion 37 that is not covered by the prepreg base material 11 made of continuous fibers. Here, as the prepreg base material 11 of continuous fibers, a prepreg base material in which continuous fibers are aligned in one direction, a prepreg base material of woven fabric, and the like can be given.

  In such a stepped portion 12c, if the difference in the number of layers between the thick portion 12a and the thin portion 12b is within the range of 1 to 4 prepreg base materials or within the range of 0.1 to 1 mm thickness, FIG. As shown in b), the number of laminated layers may be reduced (increased) at a stretch to form a step, but if the difference in the number of laminated layers exceeds 4 prepreg base materials or exceeds 1 mm thickness, fiber reinforced plastic In FIG. 3A, the stress concentration becomes remarkable, so that the step is gradually formed within the range of 1 to 4 sheets or within the range of 0.1 to 1 mm thickness as shown in FIG. It is preferable to laminate. The difference in the number of stacked layers forming a more preferable step is in the range of 1 to 2 or in the range of 0.1 to 0.5 mm. In other words, in the stepped portion 12c as described above, it is preferable that the discontinuous ends 10c of the prepreg base material are laminated so as not to overlap with each other in excess of 4 or 1 mm in thickness at the same location, More preferably, the prepreg base materials are laminated so as not to overlap each other beyond two sheets. If the end of the prepreg base material overlaps at the stepped portion adjacent to each other exceeding 4 sheets or exceeding 1 mm thickness, the stress concentration at the stepped portion becomes remarkable in the fiber reinforced plastic, and the mechanical characteristics may be deteriorated. is there.

  Moreover, in this level | step difference part 12c, each prepreg base material of the surface of a laminated body covers prepreg base materials other than each prepreg base material of this surface over the thick part 12a, level | step difference part 12c, and the thin part 12b. It is preferable that they are arranged (corresponding to the cut prepreg 10b on the upper surface and the cut prepreg 10a on the lowermost layer on the lower surface in FIG. 3B) and laminated. That is, it is preferable to laminate the discontinuous ends 10c of the prepreg base material in which the number of layers for forming a level difference at the level difference part is reduced (increased) so as not to be exposed on each surface of the layered product. If the discontinuous end 10c of the prepreg base material is exposed at the stepped portion 12c, when stress is concentrated on the stepped portion 12c in the fiber reinforced plastic, a peeling (peel) stress acts, and the breakage from the stepped portion is accelerated. May be. If each prepreg base material on the surface of the laminate is arranged so as to cover a prepreg base material other than each prepreg base material on the surface, the peeling stress is suppressed to a minimum, and the peeling stress is reduced. I can take it. In addition, as each prepreg base material of a surface, it is preferable to use the thing of abbreviation same shape.

  Further, when a metal insert is embedded in the cut portion 37 of the laminate 12 shown in FIG. 3 and cured and integrated, the assembly cost can be reduced. At that time, by providing a plurality of recesses around the metal insert, the flowed fibers can enter the recesses, and can easily fill the gaps. And can be firmly integrated.

(1a) Deaeration step Prior to the molding step described later (2) or the preheating step described later (1b), the laminated body is covered with, for example, an elastic film and sealed, and then the pressure is reduced. It is preferable to deaerate by using a vacuum dryer or the like. By deaeration, air (voids) bitten during lamination and moisture (water vapor) absorbed by the matrix resin can be removed from the laminate, and the molding described in (2) below. It is possible to obtain a fiber reinforced plastic having superior quality and quality in the process. In degassing, it is preferable to preheat the laminate in order to efficiently remove air and moisture. A preferable heating temperature depends on the matrix resin, but is generally 40 to 120 ° C. In view of device restrictions, 60 to 90 ° C. is more preferable.

  In this step, after deaeration of the laminated body, a reduced pressure environment such as in a desiccator or a sealed film (such as a vacuum pack) is maintained until the molding step (2) described later or the preheating step (1b) described later. It is more effective to save or store the state. In particular, the aspect in which the laminate is kept in a reduced pressure environment in a sealed film is the transportation of the laminate, low-temperature storage for maintaining the performance of the matrix resin, maintenance of the environment and hygiene at the work site, and the preheating step described later (1b). It can be said that it is a particularly preferable embodiment from the viewpoint of the handleability of the laminate, such as preheating at.

(1b) Preheating step Prior to the molding step (2) described later, the laminate can be heated to soften the matrix resin. In the present invention, since the notched prepreg base material that can be stretched as described above is used, the matrix resin is softened in advance in this step, and the resin viscosity is reduced to a level at which the matrix resin exhibits fluidity. ) In the molding step, it is possible to easily extend the cut portion of the laminate and fill the mold easily, which is different from the case of using an intermediate base material of continuous fibers. it can. In particular, in the case of molding a thick fiber reinforced plastic exceeding 3 mm, it takes time for heat conduction of the laminate, so that a difference between the inner and outer layers of the laminate tends to occur, and this step is followed by the molding step (2) described later. Is preferred.

  In the case where the fiber reinforced plastic has a shape having a double contour portion, in this step, the matrix resin is pre-softened, and the laminated body is preliminarily formed into a substantially shape of the fiber reinforced plastic after molding, which will be described later (2 ) In the shape having a double contour part. In forming a shape having a double contour part, after creating a laminate in a flat plate shape, before the forming process, it is possible to perform a simple operation such as bending without actively extending the cut prepreg base material. By shaping, positioning at the time of placing in the mold becomes easy, and by clarifying the extending direction, a fiber-reinforced plastic having stable quality and quality can be obtained. In this case, although the productivity is slightly lower than that of molding from a flat plate at once, it is possible to obtain a fiber reinforced plastic with higher quality and higher quality.

  As a preferable pre-shaped shape, it is preferable that the laminated body is pre-shaped in a simple shape having a single contour portion in this step. Here, “single contour shape” refers to the type of uneven shape, and when the surface of the laminate is taken out as a quadric surface, it is a point on the quadric surface and an arbitrary plane passing through the point. When referring, it refers to a set of points where there is only one intersection line where the intersecting line passing through the point is a straight line among the intersecting lines of the plane and the quadric surface, specifically, a conical shape or a cylindrical shape, Some of them apply. If it is a single contour shape, even if it is not accompanied by expansion | extension of a notch prepreg base material, it can follow if it is a certain amount of shape. For example, when molding a double-contour-shaped fiber reinforced plastic composed of one face plate such as a lunch box lid and four standing walls, the laminate is a single contour composed of one face plate and two standing walls. If the shape, that is, the U-shaped pre-molded and then placed in the molding die, positioning at the time of placement becomes easy, and the direction in which the laminate is stretched during molding can be controlled.

  Since it is preferable to carry out pre-shaping as easily as possible, as a means for this, the flat-shaped laminate is sealed with a pre-forming mold and a silicon rubber film, etc., and the pre-forming mold is formed by decompressing the sealed space. It is preferable to press against.

  In the degassing step (1a), if the laminate is kept in a reduced pressure environment in a sealed film, air and moisture can be further improved by preheating in the sealed state in this step. In particular, it can be removed from the laminate.

(2) Molding process When the laminate is pressed against a mold and cured or solidified to form a fiber reinforced plastic, the stepped portion of the laminate corresponds to the stepped portion having a different thickness formed on the mold. After positioning and arranging, at least one of the thick part, the thin part, or the step part of the laminate is extended to fill each of the thick part, the thin part, and the step part of the mold. In this invention, since it shape | molds using the notch prepreg base material which can be extended | stretched, it becomes possible to extend | stretch a laminated body (especially notch part), and to make it fill with a shaping | molding die easily. When elongating, it has been found that the problem of the present invention can be solved by elongating and molding the step portion provided in the mold, that is, the portion corresponding to the step portion of the laminate. This point is the greatest feature of the present invention. By first bringing the step portion into contact with the mold and using it as a reference, the extension of the cut prepreg base material at the thick and thin portions can be significantly controlled. Conversely speaking, it is extremely difficult to control the extension at the step portion of the laminate and the position of the step portion of the laminate, based on the thick or thin portion of the laminate to be stretched, without variations, A fiber-reinforced plastic having a desired size cannot be stably molded.

  In this step, positioning of the laminate to the laminate is performed by mechanically holding and fixing to the place where the mold or the laminate fixing jig is displayed in advance, or the adhesive that the matrix resin has. It is preferable to adopt a means for fixing by sex. With such positioning means, it is possible to reliably position and arrange the stepped portions of the laminate so as to correspond to the stepped portions having different plate thicknesses formed in the mold. In particular, when mechanically gripping and fixing, a predetermined portion may be gripped in a dot shape, or the predetermined portion may be gripped in a line or a plane. Although depending on the shape of the molding die, it is preferable to hold the laminate in a dotted manner from the viewpoint of simply positioning and not hindering the extension of the laminate after placement as much as possible. In particular, when fixing with the adhesive property of the matrix resin, since it may be difficult to reliably fix it only by point-like gripping, the laminate may be fixed to the mold in a linear or planar shape. preferable. Further, after the preheating step (1b), the adhesiveness of the matrix resin is further improved and can be reliably fixed and arranged on the mold.

  It is desirable that the mold is composed of at least two of a fixed mold and a movable mold. Further, a combination of two or more fixed molds or movable molds such as a slide mold, a core, and a counter plate (a cowl plate) may be used as a molding mold. As the fixed mold, for example, a metal mold such as steel, an aluminum alloy, or a nickel alloy can be used, or a fiber reinforced plastic FRP mold can be used. As the movable mold, for example, a metal mold can be used, and a stretchable film or the like can be simply used.

  Using a molding die composed of at least two of a fixed die and a movable die, the laminate is placed on the fixed die, and when the movable die is pressed against the fixed die and molded, the laminate is first placed on the mold. It is preferable to arrange at least a stepped portion in the contacting portion. For example, in the case where a mold is used as the fixed mold and the movable mold, before the mold is clamped, the laminated body is placed on the fixed mold so that the stepped part of the laminated body corresponds to the stepped part formed in the fixed mold. After that, the laminate can be molded by clamping. As described above, the positioning of the laminated body is either mechanically held and fixed at the place where the mold or the laminated body fixing jig is displayed in advance, or fixed with the adhesiveness of the matrix resin. Measures can be taken.

  In addition, before the mold is clamped, when the laminated body is arranged so that neither the fixed mold nor the movable mold is touched (the mode shown in FIG. 4 described later), the mold is clamped to form the laminated body. When the movable mold comes into contact, the laminated body can be molded by clamping after arranging the stepped part of the laminated body so as to correspond to the stepped part formed in the movable mold. In particular, it is preferable that the positioning means for the laminated body in this case is mechanically gripped and fixed at a place to be arranged that is displayed in advance on the laminated body fixing jig.

  On the other hand, in the case of using a stretchable film as the movable mold, when the laminated body is disposed on the fixed mold (a mode of FIG. 5 described later), the level difference of the laminated body is formed on the stepped portion formed in the fixed mold. After the laminated body is arranged on the fixed mold so that the portions correspond, the inside of the cavity can be decompressed to form the laminated body. In addition, in the case of using a combination of a stretcher film and an address plate as a movable type, the cavity is depressurized after the step portion of the laminate corresponds to the step formed on the address plate. Thus, a laminate can be formed. In particular, the means for positioning the laminate in this case may be a means for fixing with the adhesive property of the matrix resin, and it is particularly preferable to fix it in a linear or planar shape.

  If both the fixed mold and the movable mold are formed of a metal mold having a large heat capacity, the laminate can be quickly controlled to the mold temperature, and a large amount of fiber-reinforced plastic can be molded with high efficiency. In addition, the mold can be clamped to apply a high pressure to the laminate when the laminate is cured or solidified, and the cut prepreg base material can be sufficiently stretched to improve the quality and quality of the fiber reinforced plastic. be able to. In particular, when molding a fiber reinforced plastic with a thickness exceeding 3 mm, it takes time for the laminated body to conduct heat. Therefore, it is preferable to use a mold for both the fixed mold and the movable mold. As a heating means in the case of using a mold, it is preferable to control the temperature by heating the mold itself by circulation of a cartridge heater or a heat medium.

  FIG. 4 is a cross-sectional view showing an example of a method for producing a fiber-reinforced plastic according to the present invention.

  The molding die 28 in FIG. 4 includes a movable die 28a and a fixed die 28b. In addition, it has a frame-shaped laminated body positioning clamp (laminated body fixing jig) 28d that can be moved with mold clamping of the mold. The laminated body 12 is mechanically gripped and fixed in a dot shape to a clamp 28d supported by a spring 27 for positioning. Thereafter, the movable mold is lowered, and the stepped portion of the movable mold 28 a and the stepped portion 12 c of the laminated body 12 are first brought into contact with each other. At this time, the thin portion 12b of the laminated body 12 is also in contact with the movable mold 28a at the same time. The step portion 12c and the thin portion 12b of the laminate 12 that first contacts the movable die 28a are temporarily fixed by the movable die 28a and the fixed die 28b. Thereafter, the thick portion 12a of the laminate 12 is brought into contact with the fixed mold 28b, and the thick portion is extended to obtain a fiber reinforced plastic. At least from the stepped part, the mold is clamped to fix the starting point of elongation and control the flow, thereby realizing uniform elongation of the cut prepreg base material and high-quality, high-quality fibers Reinforced plastic can be molded with few defective products. Moreover, if a demolding mechanism is provided, it is excellent in mass productivity.

  On the other hand, if the movable mold is made of an inexpensive stretchable film, the fixed cost can be reduced without using large equipment such as a mold or its elevator, and fiber reinforced plastic can be molded at low cost. Is easy to handle. Further, as a movable type, a stretchable film and a contact plate (made of metal, fiber reinforced plastic, or the like) may be used in combination. In this case, the fixed mold may be a mold or an FRP mold. When using a stretchable film, the temperature may be controlled by heating only the fixed mold, or the fixed mold and the stretchable film are placed in an oven (hot air, induction heating, high frequency heating, etc.). Each may be temperature controlled, or both may be combined. The former is preferable when molding thin fiber-reinforced plastics with a thickness of 3 mm or less, because the heat conduction of the laminate is short, and when molding thick fiber-reinforced plastics with a thickness of more than 3 mm, it takes time to heat the laminate. Therefore, the latter is preferable. When the thick part exceeds 3 mm and the thin part is 3 mm or less, it is preferable to combine both.

  FIG. 5 is a plan view and a cross-sectional view showing an example of the method for producing the fiber-reinforced plastic of the present invention.

  The mold 28 in FIG. 5 is composed of a fixed mold 28 c and a stretchable film 32. The laminated body 12 is brought into contact with the stepped portion formed on the fixed mold 28c so that the stepped portion 12c of the laminated body 12 corresponds to the laminated body 12 and is fixed on the mold in a linear shape with the adhesiveness of the matrix resin. , Positioning. At this time, the thick portion 12a and the thin portion 12b of the laminate 12 are also in linear contact with the fixed mold 28c at the same time. Thereafter, the stretchable film 32 is sealed as a fixed mold 28c and a movable mold with a sealant 31 or the like leaving a pipe serving as a degassing port 26, and the sealed space (cavity) 30 is decompressed using a vacuum pump or the like, The laminated body 12 is pressed in a planar shape against the fixed mold 28c by a pressure difference from the atmospheric pressure, and the thick part 12a, the thin part 12b, and the step part 12c are respectively extended to obtain a fiber reinforced plastic. The greatly extended portions are the thick portion 12 a and the thin portion 12 b that form both end portions (double contour portion 25) having the convex shape 36.

  Further, this mold is placed in a pressure vessel such as an autoclave, and the laminate 12 is pressed against the fixed die 28c with a pressure difference (about 0.1 to 0.6 MPa) between the pressure in the pressure vessel and the sealed space 30. It is also possible. The stretchable film may be made disposable for each molding, but a durable silicone rubber film or the like can be used as the openable lid, which is preferable from the viewpoint of cost reduction of the auxiliary material.

  When the matrix resin is a thermosetting resin, the heating temperature in the preheating step (1b) is preferably lower than the temperature of the mold in this step. That is, in the preheating step, the matrix resin is softened by heating with an IR heater or oven to a temperature higher than the glass transition temperature of the thermosetting resin in the prepreg substrate (preferably 35 to 110 ° C, more preferably 40 to 90 ° C), It is preferable to obtain a fiber reinforced plastic by hot press molding in which the matrix resin is cured by pressing against a mold whose temperature is controlled higher than the preheating temperature (preferably a glass transition temperature of 120 to 200 ° C. in the fiber reinforced plastic). . Unlike the thermoplastic resin described later, the thermosetting resin improves the glass transition temperature by the resin curing reaction. Therefore, when molding is performed by controlling the temperature as described above, the thermosetting resin shortens the occupation time of the molding die. The problems of the invention can be solved.

  As a molding condition when a thermosetting resin is used as the matrix resin, it is preferable that the mold temperature T1 in the molding process and the mold temperature T2 in the demolding process are substantially constant. Note that the temperature of the mold is represented by the average of the temperatures measured with a thermocouple at multiple points on the surface of the cavity that touches the laminate (if the mold is a movable mold or a fixed mold, at least one point is measured). . Here, that the mold temperature T in the present invention is substantially constant means that the variation of the mold temperature is usually within a range of ± 10 ° C. Further, both T1 and T2 should not change over time.

In the present invention, the fiber reinforced plastic has a mold temperature T with respect to an exothermic peak temperature Tp based on differential scanning calorimetry (DSC) of a thermosetting resin used for a prepreg substrate.
(Tp-60) ≦ T ≦ (Tp + 20) (I)
It is preferable to manufacture within the range. More preferably,
(Tp-30) ≦ T ≦ Tp (II)
Is within the range. When the mold temperature T is lower than Tp-60, the time required for curing of the resin becomes very long, and the curing may be insufficient. On the other hand, when it is higher than Tp + 20, a rapid reaction of the resin may cause generation of voids inside the resin and poor curing. In addition, the exothermic peak temperature Tp based on DSC in the present invention is performed according to JIS K7121 (1987), and is an exotherm obtained by raising the temperature at a temperature of 30 to 180 ° C. under a temperature raising rate of 10 ° C./min. The value is the peak of the curve. The test piece referred to in JIS K7121 (1987) is a paste in the present invention. Therefore, “condition adjustment of test piece” and “test piece” can be referred to as “condition adjustment of paste” and “paste”, respectively. In principle, the state of the paste is adjusted to stand for 6 to 8 hours at a temperature of 23 ± 2 ° C. and a relative humidity of 50 ± 5%, and no heat treatment is performed. In addition, since the paste is measured in the form of a paste, there is no regulation regarding the dimensions.

  When the matrix resin is a thermoplastic resin, the heating temperature in the preheating step (1b) is preferably higher than the temperature of the mold in this step. That is, in the preheating step, the matrix is heated by an IR heater or oven near the glass transition temperature or melting point of the thermoplastic resin or higher (generally 180 to 350 ° C., depending on the type of the thermoplastic resin). The resin is softened and pressed against a mold controlled at room temperature or at a temperature lower than the laminate (generally 30 to 100 ° C., depending on the type of thermoplastic resin), and the matrix resin is solidified. It is preferable to obtain a fiber reinforced plastic by cold press (stamping) molding. In general, cold press molding using a thermoplastic resin has an advantage that the molding cycle time can be shortened compared to hot press molding using a thermosetting resin.

(3) Demolding step The fiber reinforced plastic is taken out from the mold. When a thermosetting resin is used for the matrix resin, it is hardened after it has been cured or hardened to the extent that it can be removed from the mold. After that, the fiber reinforced plastic is taken out from the mold.

(4) Post-heating step It is preferable to heat the fiber reinforced plastic to a temperature equal to or higher than the mold temperature in the molding step (2) as necessary. When the matrix resin is a thermosetting resin, it can be completely cured by passing through this step by minimizing the pressing time in the molding step (2) to a level that allows demolding. When the matrix resin is a thermoplastic resin, when cold press (stamping) molding is performed, the mold temperature in the molding step (2) is controlled to a temperature lower than the glass transition temperature and the melting point. In such a case, for example, by performing this step of post-heating to a temperature exceeding the glass transition temperature, it is possible to correct the warp generated in the fiber-reinforced plastic or to perform an annealing process for promoting crystallization.

  In this step, it is preferable to simultaneously post-heat a plurality of fiber reinforced plastics without using a molding die because the occupation time of the expensive molding die used in the molding step (2) can be shortened. Of course, in order to strictly control the dimensions of the fiber reinforced plastic, a mold for the post-heating process may be used in this process. However, if a simple fixing jig or the like is used, the purpose of this process can be achieved at a lower cost. This is preferable because it is possible. As a heating means in this step, it is preferable to post-heat a plurality of fiber reinforced plastics simultaneously without using a mold, and therefore an oven (hot air, induction heating, high frequency heating, etc.) that can take a wide heating area is used. Is preferred.

  As described above, according to the present invention, high-quality and high-quality fiber-reinforced plastics can be easily produced regardless of whether the fiber-reinforced plastic has a complicated shape or a thermosetting resin or a thermoplastic resin is used as a matrix resin. Can be manufactured. Since the fiber-reinforced plastic obtained in this manner does not stretch during molding unlike a continuous fiber substrate, the laminate is firmly pressed against the mold. Also, even if it has stepped parts with different plate thicknesses, it is possible to obtain a high-quality and high-quality fiber-reinforced plastic that has been sufficiently transferred to the mold surface by forming it by using the stepped part of the laminate as a reference. be able to. Furthermore, since a cut prepreg base material that can be stretched at the time of molding is used, a laminate may be prepared smaller than the fiber reinforced plastic that is the final shape, so the bulky laminate cannot fit in the mold. There are few occurrences of fiber biting between burrs, wrinkles, and molds. Moreover, a trimless fiber-reinforced plastic can be obtained by using a matched die. As a feature of the fiber reinforced plastic, the fiber length Lc of all the reinforced fibers included in at least a part of the fiber reinforced plastic (particularly, the double contour portion) is in the range of 10 to 100 mm.

  More preferably, all of the reinforcing fibers constituting the cut prepreg base material are cut by cutting, and the fiber length L cut by the cutting is in the range of 10 to 100 mm. By making all the fiber lengths L of the cut prepreg base material 100 mm or less, it is possible to manufacture a cut prepreg base material and a laminate without considering the shape of the fiber reinforced plastic to be finally produced. Because it can, there is a big merit in terms of design and work efficiency. In addition, the air trapped at the time of stacking can be easily deaerated through a cut in the thickness direction, voids are hardly generated, and high mechanical properties can be expected. In the present invention, “all of the reinforcing fibers are divided by the incision” means that 95% or more of the number of reinforcing fibers contained in the prepreg base material is divided into 10 to 100 mm.

  As one of the preferred incision forms of the incision prepreg base material, the incision is linear, and the projected length Ws in which the incision is projected in the vertical direction of the reinforcing fiber is 30 μm to 100 mm, and is intermittent And as one of the forms of the cutting prepreg base material arrange | positioned periodically and the more preferable cutting prepreg base material, the cutting prepreg base material by which the said cutting is further arrange | positioned over the whole surface is mentioned. Since the incisions are not continuous but intermittent, the incised prepreg base material is not separated by the incision and is excellent in handleability during lamination. In addition, by periodically arranging the cuts, the position of the cuts can be controlled, and the dynamic characteristics can be controlled. Here, the “projection length Ws obtained by projecting the cut in the vertical direction of the reinforcing fiber” means that the cut 4 is cut with the vertical direction (fiber orthogonal direction 2) of the reinforcing fiber 3 as the projection plane as shown in FIG. The length 9 when projected perpendicularly to the projection surface (fiber longitudinal direction 1) from the protrusion 4 is indicated. Further, the phrase “the cuts are arranged over the entire surface” means that there are provided cuts that divide all the reinforcing fibers contained in the cut prepreg base material into a length of 10 to 100 mm.

  The discontinuous ends of the reinforcing fibers generated by the cutting are likely to cause stress concentration when a load is applied to the fiber reinforced plastic, and become a starting point of fracture. Therefore, it is advantageous in strength that the cut is smaller. Ws is an index indicating the amount of reinforcing fiber to be divided, and when Ws is 100 mm or less, the strength is greatly improved. However, when Ws is smaller than 30 μm, it may be difficult to control the cut, and it may be difficult to ensure that L is 10 to 100 mm over the entire cut portion of the reinforcing fiber. That is, if reinforcing fibers that are not divided by the cuts are present in the cuts that are expected to conform to the complex shape, the fibers may be remarkably lowered in fluidity, but the cuts are made longer. There is a problem that the area where L is less than 10 mm increases and the strength may be lower than the design value. Conversely, when Ws is greater than 100 mm, the strength is almost constant. That is, when the discontinuous ends of the reinforcing fibers become larger than a certain level, the loads at which the fracture starts are substantially equal. More preferably, the strength is significantly improved when Ws is 1.5 mm or less. That is, from the viewpoint that the cutting can be inserted with a simple device, Ws is preferably 1 to 100 mm. On the other hand, in view of the relationship between the ease of controlling the cutting and the mechanical characteristics, Ws Is preferably 30 μm to 1.5 mm, more preferably in the range of 50 μm to 1 mm.

  FIG. 6 is an enlarged plan view showing an example of a cut prepreg base material used in the present invention.

  Hereinafter, an example of a preferable cutting pattern will be described in detail with reference to FIG. A plurality of controlled and aligned cuts 4 are made on a prepreg base material in which reinforcing fibers are aligned in one direction. The fibers are divided by the pair of cuts in the fiber longitudinal direction 1, and the interval 6 is set to 10 to 100 mm, so that the fiber length L of the reinforcing fiber on the prepreg base material is substantially 10 to 100 mm. be able to.

  FIG. 6 shows an example in which both the fiber length L and the projected length Ws obtained by projecting the cut in the vertical direction of the reinforcing fiber are one type. The row 7a composed of the first intermittent cuts and the row 7c composed of the third intermittent cuts can be overlapped by moving L in the fiber longitudinal direction 1 and the second intermittent cuts. The row 7b made of a notch and the row 7d made of a fourth intermittent cut can be overlapped by L translation in the fiber longitudinal direction 1. In addition, there are fibers cut into the first and second cut rows and the third and fourth cut rows, and there is a width 5 cut to a fiber length L or less. A cut prepreg base material can be produced stably with a fiber length of 100 mm or less.

  FIG. 7 is a plan view showing an example of a cut prepreg base material used in the present invention.

  Although several cutting patterns are illustrated in FIGS. 7A to 7F, any pattern may be used as long as the above conditions are satisfied. In FIG. 7, the arrangement of the reinforcing fibers is omitted, but the arrangement direction of the reinforcing fibers is the vertical direction. 7 (a), (b) or (c) is an embodiment in which the cut is in the fiber orthogonal direction 2, and FIG. 7 (d), (e) or (f) is in the fiber orthogonal direction. 2 shows a state of being inclined from 2. Among the fibers that are divided into the cuts other than the pair of cuts, there are fibers shorter than the fiber length, but such fibers are not included in the fiber having the fiber length L defined in the present invention. And the fewer the fibers of 10 mm or less, the better.

  As described in FIG. 2, the cut prepreg base material used in the present invention has the reinforcing fibers aligned in one direction because the flow of the matrix resin in the 90 ° direction is the driving force of the flow of the reinforcing fibers. When two or more prepreg base materials are laminated in different fiber directions, fluidity in the fiber longitudinal direction is exhibited. Therefore, the layer adjacent to the cut prepreg base material is a prepreg base material (including the cut prepreg base material according to the present invention) in which reinforcing fibers are oriented in one direction, and in a fiber direction different from the cut prepreg base material. It is good to be laminated. When it is unavoidable to stack the cut prepreg base materials in the same fiber direction adjacent to each other, it is preferable to stack the cuts so that the cuts do not overlap. Moreover, a resin film etc. may be laminated | stacked between the layers of these cutting prepreg base materials, and fluidity | liquidity may be improved. In addition, a continuous fiber base material can be disposed in a region that does not need to flow, and the mechanical properties of the region can be further improved.

  If the fiber direction is different between layers, a difference occurs in the flow direction and distance of each layer, but the displacement difference can be absorbed by sliding between the layers. That is, even if the fiber volume content Vf is as high as 45 to 65%, the laminate used in the present invention can exhibit high fluidity because the resin can be unevenly distributed between the layers. For example, in the case of SMC, fluidity differs between randomly dispersed chopped strands and tries to flow in different directions, but the fibers interfere with each other and hardly flow, and the fluidity is only up to about 40% Vf. Can not be secured. That is, the laminate used in the present invention has a characteristic that high fluidity can be expressed even with a high Vf configuration capable of improving mechanical properties. In addition, due to the characteristics of this fluidity, the obtained fiber reinforced plastic can maintain a laminated structure even if it has a complex shape, expresses high elastic modulus and strength, reduces strength variation, and also has impact characteristics. Greatly improved.

  More preferably, the notch prepreg base material is adjacent to two or more consecutive layers, and for any two adjacent layers of the two or more layers, any notch geometry on one notch prepreg base material. It is preferable to laminate so that the center and the geometric center of any notch on the other notch prepreg base material are separated by 5 mm or more. It is important in two senses that the geometric centers of the cuts of adjacent cut prepreg substrates are separated from each other. The first reason is that when the laminate is stretched during molding, if the cuts are connected to each other, it is easy to tear, and the molding of the present invention may fail. Moreover, even if it does not tear at the time of shaping | molding, in the area | region where the geometrical center of a notch is near, the fiber content rate becomes low and there is a possibility of affecting the quality such as reducing the thickness. Second, when it becomes fiber reinforced plastic, the ends of the bundle of reinforced fibers that are split by cutting are so-called stress concentration points, so they are likely to be the starting point of breakage. In some cases, cracks are easily connected and the strength is lowered.

  FIG. 8 is a plan view showing an example of the cutting position relationship of the laminate used in the present invention.

  As shown in FIG. 8, in the relationship between the two layers of the laminated cut prepreg base material, the geometrical centers 8 of the closest cuts of the first cut 4a and the second cut 4b 8 (b) to (d) are separated, and preferably 5 mm or more, it is possible to wipe out the concerns during molding and the mechanical characteristics. If the distance is closer than 5 mm, a problem may occur. Here, the “geometric center” is a point around which the first moment is zero, and the following formula is established for the geometric center point g with respect to the point x on the cut.

  In order to obtain the incision prepreg base material of the present invention, as a method of cutting into the prepreg base material, first, a continuous fiber prepreg base material aligned in one direction is prepared, and then manual operation using a cutter is performed. A method of making a cut with a cutter or a cutting machine, or a continuous roller prepreg substrate manufacturing process of continuous fibers aligned in one direction, or continuously pressing a rotating roller with a blade in place at a predetermined position, or a prepreg substrate in multiple layers For example, there is a method in which the blades are stacked and pushed with a mold in which a blade is arranged at a predetermined position. When making a cut into a part of the prepreg base material easily at the molding site etc., the former makes a large amount of the cut prepreg base material in consideration of production efficiency, especially when making a cut on the entire surface. The latter is suitable. When a rotating roller is used, the roller may be directly cut out to provide a predetermined blade, but by cutting a flat plate around a magnet roller or the like and winding a sheet-shaped mold with the blade placed at a predetermined position The replacement of the blade is easy and preferable. By using such a rotating roller, it is possible to insert the cut well even with a cut prepreg base material having a small Ws (specifically, 1 mm or less). After making the cut, the cut prepreg base material may be further thermocompression bonded with a roller or the like, so that the resin is filled and fused in the cut portion, thereby improving the handleability.

  The characteristics of the fiber reinforced plastic obtained by molding according to the present invention using an example of the cut prepreg base material obtained as described above will be described with reference to FIG. FIG. 9 is a plan view and a cross-sectional view showing an example of the state of extension of the laminate used in the present invention.

  A part of the laminate 12 in which the cut prepreg base material 10 in which the cut 4 crosses the fiber 3 in the 90 ° direction was laminated (FIG. 9A), and the laminate 12 was formed by the present invention. A part of the fiber reinforced plastic 16 is shown in Fig. 9 (b), which is a plan view showing a close-up of the layer derived from the cut prepreg base material 10, and a cross-sectional view taken along the line AA of the plan view. As shown in FIGS. 7A to 7C, the notch prepreg base material 10 in FIG. 7A is provided with a notch perpendicular to the fiber, and the notch 4 penetrates in the thickness direction of the layer. By setting the fiber length L to 100 mm or less, the fluidity is ensured, and the fiber reinforced plastic 16 having an area larger than that of the laminate 12 can be easily obtained (however, the thickness is reduced). When the stretched fiber reinforced plastic 16 is obtained as in b) The discontinuous fiber layer 17 derived from the prepreg base material 10 extends in the direction perpendicular to the fiber and generates a region 18 where the fiber does not exist (cut opening), which is generally a pressure at which the reinforcing fiber is formed. 9, in the case of Fig. 9, a cut opening 18 is generated for the length of the extension 18. As shown in the cross-sectional view, this region 18 has an adjacent layer 19 invading to form a substantially triangular shape. It is occupied by the resin-rich portion 20 and the region where the adjacent layer 19 penetrates.For example, when a cut prepreg base material with cuts is formed on the entire surface of the fiber reinforced plastic, the fibers flow. In the region, the laminate cut opening 18 is observed, and more preferably, all the layers constituting the fiber reinforced plastic have a fiber length Lc in the range of 10 to 100 mm and a width Wsc. Is composed of strip-shaped aggregates of 30 μm to 150 mm In the present invention, as shown in a region 35 surrounded by a dotted line in FIG. The area surrounded by is expressed as a strip shape, and is a strip shape that is the spread width in the fiber vertical direction after molding with respect to the projection length Ws obtained by projecting the cut in the cut prepreg base material in the vertical direction of the reinforcing fiber. Since the width Wsc is expected to be extended up to about 50% by molding, Wsc is in the range of 30 μm to 150 mm.

  As the cut prepreg base material suitably used in the present invention other than the cut prepreg base material whose cut is perpendicular to the fiber as shown in FIGS. As shown in f), the incision is preferably inclined from the fiber orthogonal direction 2. When making an incision with a rotating roller or the like industrially, if an attempt is made to make an incision in the fiber orthogonal direction 2 into the prepreg base material supplied in the fiber direction, the fiber needs to be cut at a stretch and a large force is required. In addition, the durability of the blade is lowered, and the fibers easily escape in the orthogonal direction 2, which increases the amount of uncut fibers. On the other hand, since the cut is inclined from the fiber orthogonal direction 2, the amount of fibers cut per unit length of the blade is reduced, the fibers can be cut with a small force, the durability of the blades is high, and the fiber uncut residue can be reduced. . Furthermore, since the cut is inclined from the fiber orthogonal direction 2, the projection length Ws obtained by projecting the cut in the vertical direction of the reinforcing fiber can be reduced with respect to the cut length. An improvement in strength is expected by reducing the amount of fiber cut by the cutting. When cutting in the fiber orthogonal direction 2, it is preferable to prepare a small blade in order to reduce Ws, but if it is too small, there may be a problem in durability and workability.

  Still another preferred form of the cut prepreg base material is a cut prepreg base material in which the absolute value of the angle Θ formed by the cut with the reinforcing fiber is in the range of 2 to 15 °. In the case of this cut prepreg base material, the cut shown in FIG. 11 may be used, which is an intermittent cut and the angle Θ formed by the cut with the reinforcing fiber is small, or the continuous cut shown in FIG. It may be included. Even if the absolute value of Θ is larger than 15 °, fluidity can be obtained, and higher mechanical properties can be obtained as compared with conventional SMC, etc., but in particular, when the absolute value of Θ is 15 ° or less. Significant improvement in mechanical properties. On the other hand, even if the absolute value of Θ is smaller than 2 °, sufficient fluidity and mechanical properties can be obtained, but it is difficult to make a stable cut. That is, when the angle of cut with respect to the fiber becomes smaller, the fiber easily escapes from the blade when making the cut, and in order to make the fiber length L 100 mm or less, the absolute value of Θ is If it is less than 2 °, production stability may be lacking, such as at least the shortest distance between notches being less than 0.9 mm. In addition, when the distance between the cuts is small as described above, there may be a problem in that handling at the time of stacking becomes difficult. In view of the relationship between the ease of controlling the cutting and the mechanical characteristics, it is more preferably in the range of 5 to 11 °.

  FIG. 12 is a plan view showing an example of a cut prepreg base material used in the present invention.

  The incision may be a curve as shown in FIG. 12 (c), but a straight line is preferable because the fluidity can be easily controlled. Further, the length L of the reinforcing fiber divided by the cutting may not be constant as shown in FIG. 12B, but the fiber length L is constant over the entire surface as shown in FIG. It is preferable because it is easy to control fluidity and can further suppress variation in strength. Here, the prescribed linear shape means a state in which a part of a geometrical straight line is formed, but unless the effect of facilitating the control of the fluidity is impaired, the geometrical Even if there is a portion that does not form a part of the straight line, there is no problem. As a result, even if there is a portion where the fiber length L is not constant over the entire surface (in this case, the fiber length L is substantially over the entire surface). It can be said that it is constant).

  As a preferable example [1], it is preferable that the cuts 4c are continuously formed as shown in FIG. 10 and FIGS. 12 (a) to 12 (c). In the pattern of Example [1], since the cut 4c is not intermittent, the flow turbulence does not occur near the cut end, and all the fiber lengths L are constant in the region where the cut 4c is inserted. The flow is stable. When the cuts are provided on the entire surface of the prepreg base material, since the cuts 4c are continuously made, in order to prevent the cut prepreg base material 10 from falling apart, the periphery of the cut prepreg base material It is possible to improve the handleability by providing an area where the cut is not connected to the part, or by gripping with a support such as a sheet-like release paper or film without the cut. In addition, in order to improve handling at the time of stacking, two cut prepreg base materials that have been cut in advance are stacked so that the cuts do not overlap. It is good also as a 2 layer laminated body laminated | stacked so that it may become a shape.

In addition, as another preferable example [2], as shown in FIG. 11, when the length 9 projected in the vertical direction of the reinforcing fiber is Ws, the intermittent cut 4d in which Ws is in the range of 30 μm to 100 mm is provided. The notch prepreg base material 10 is provided on the entire surface, and the notch 4d ₁ and the notch 4d ₂ adjacent in the fiber longitudinal direction of the notch 4d ₁ may have the same geometric shape. FIG. 11 shows an example in which both L and Ws are one type. Any of the cuts 4d (for example, 4d ₁ ) has another cut 4d (for example, 4d ₂ ) that overlaps by translating in the fiber direction. By having a width 5 in which the fibers are divided by the adjacent notches at a fiber length shorter than the fiber length L divided by the notches 4d that form pairs in the fiber direction, the fibers are stably The cut prepreg base material 10 can be manufactured with a length of 100 mm or less. In the pattern of Example [2], when the obtained cut prepreg base material 10 is laminated, the cut is intermittent, and thus the handleability is excellent. Although other patterns are illustrated in FIGS. 12D and 12E, any pattern may be used as long as the above conditions are satisfied.

  The characteristics of the fiber reinforced plastic 16 of the fiber reinforced plastic obtained by molding according to the present invention using the cut prepreg base material of the preferred example [1] obtained in this way will be described with reference to FIG. FIG. 13 is a plan view and a cross-sectional view showing an example of a state of extension of the laminate used in the present invention.

  FIG. 13A shows a part of a laminate 12 in which the cut prepreg base material 10 according to the present invention is laminated, and a part of the fiber reinforced plastic 16 of the fiber reinforced plastic obtained by molding the laminate 12 according to the present invention. FIG. 13B shows a plan view in which the layers derived from the cut prepreg substrate 10 are respectively close-up and a cross-sectional view taken along the line AA of the plan view. As shown to Fig.13 (a), the cutting prepreg base material 10 is provided in the whole surface with the cutting 4c whose angle with the fiber 3 is 15 degrees or less, and the cutting 4c has penetrated the thickness direction of the layer. . By setting the fiber length L to 100 mm or less, fluidity is ensured, and the fiber reinforced plastic 16 whose area is easily extended from the laminate 12 can be obtained. As shown in FIG. 13B, when the elongated fiber reinforced plastic 16 is obtained, the discontinuous fiber layer 17 derived from the cut prepreg base material 10 extends in the fiber vertical direction, and the fiber 3 itself rotates 24. In order to increase the area of the elongated region, the region (cut opening) 18 where no fiber exists is not substantially generated as shown in FIG. 9, and the area on the surface of the layer of the cut opening is compared with the surface area of the layer. And 10% or less. Therefore, as can be seen from the cross-sectional view, the adjacent layer 19 does not enter, and the fiber-reinforced plastic 16 having high rigidity, high strength, and high quality without the undulation of the layer and the resin rich portion can be obtained. Since the fibers 3 are arranged all over the surface, there is no difference in rigidity in the surface, and the design can be easily applied as in the conventional continuous fiber reinforced plastic. A further epoch-making effect that this fiber rotates and stretches to obtain a fiber reinforced plastic having no layer waviness can be obtained only when the absolute value of the angle Θ formed with the cut fiber is 15 ° or less. . Further, in terms of strength, when attention is paid to the fibers that are oriented within about ± 10 ° from the load direction as described above, the fiber bundle end portion 22 lies down with respect to the load direction as shown in FIG. You can see how it is. Since the fiber bundle end portion 22 is slanted in the layer thickness direction, load transmission is smooth, and peeling from the fiber bundle end portion 22 hardly occurs. Therefore, further improvement in strength is expected compared to FIG. The fiber bundle end 22 is inclined in the layer thickness direction because when the above-mentioned fiber rotates, there is a gentle distribution in the rotation 24 of the fiber 3 from the upper surface to the lower surface due to friction between the upper surface and the lower surface. It is considered that the presence distribution of the fibers 3 occurs in the layer thickness direction, and the fiber bundle end 22 is inclined in the layer thickness direction. In such a layer of fiber reinforced plastic 16, a further breakthrough effect of significantly increasing the strength by forming an oblique fiber bundle end in the layer thickness direction is the absolute angle Θ formed with the fiber 3 of the cut 4 c. It can be obtained only when the value is 15 ° or less.

  FIG. 14 is a plan view showing an example of the state of extension of the laminate used in the present invention.

  In FIG. 14, a part of the laminate 12 in which the cut prepreg base material 10 of the preferred example [2] is laminated is shown in FIG. 14 (a), and a part of the fiber reinforced plastic 16 in which the laminate 12 is molded is shown in FIG. The top view which closed up the layer derived from the cutting prepreg base material 10 to (b) was shown, respectively. As shown in FIG. 14 (a), the cut prepreg base material 10 is provided with intermittent cuts 4d having an absolute value of the angle Θ between the fibers 3 of 15 ° or less and the cuts 4d are layers. It penetrates the thickness direction. By setting the fiber length L to 100 mm or less over the entire surface of the cut prepreg base material 10 by the cut 4d, the fluidity is ensured, and the fiber reinforced plastic 16 whose area is easily extended from the laminate 12 can be obtained. . By reducing the cut length and the cut angle, the projection length Ws obtained by projecting the cut in the vertical direction of the reinforcing fiber can be made 1.5 mm or less. As shown in FIG. 14B, when the elongated fiber reinforced plastic 16 is obtained, the discontinuous fiber layer 17 derived from the cut prepreg base material 10 does not extend in the fiber direction when extending in the fiber vertical direction. Therefore, a region (cut opening portion) 18 in which no fiber exists is generated, but the adjacent discontinuous fiber group flows in the fiber vertical direction so that the cut opening portion 18 is filled. The area becomes smaller. This tendency becomes particularly noticeable when the projected length Ws obtained by projecting the cut in the vertical direction of the reinforcing fiber is 1.5 mm or less, and the cut opening 18 is not substantially generated. The area on the surface of the layer can be in the range of 0.1 to 10% compared to the surface area of the layer. Therefore, the adjacent layer does not penetrate in the thickness direction, and the fiber-reinforced plastic 16 having high rigidity, high strength, and high quality without the undulation of the layer and the resin rich portion can be obtained. Since the fibers 3 are arranged all over the surface, there is no difference in rigidity in the surface, and the design can be easily applied as in the conventional continuous fiber reinforced plastic. The revolutionary effect of filling the cut opening 18 with the flow in the vertical direction of the fiber to obtain a fiber reinforced plastic 16 without layer undulation is that the absolute value of the cut angle Θ is 15 ° or less and the cut is strengthened. It can be obtained for the first time when the projection length Ws projected in the vertical direction of the fiber is 1.5 mm or less. More preferably, when Ws is 1 mm or less, higher rigidity, higher strength, and higher quality can be obtained, and application as an outer plate member is also possible.

  Furthermore, it is preferable for the fluidity improvement that the laminate is composed only of the cut prepreg base material. More preferably, the laminate is composed only of a cut prepreg base material, and all the fiber lengths L of the reinforcing fibers constituting the cut prepreg base material are within a range of 10 to 100 mm. Making a cut according to the shape is very time-consuming in terms of design and work, so for quality stability, a cut is made on the entire surface of the prepreg base material to determine which area of the laminate. It is preferable to make it easy to follow even complicated shapes. In addition, by cutting the entire surface, even if the laminate is a flat plate, the laminate will be stretched as a whole and becomes a fiber reinforced plastic with fibers spread all over. Can express well. Further, the laminate can be prepared smaller than the cavity of the mold, and the mold can be easily clamped without biting the laminate between the fixed mold and the movable mold of the mold.

  Examples of reinforcing fibers used in the prepreg base material of the present invention include organic fibers such as aramid fibers, polyethylene fibers, polyparaphenylene benzoxador (PBO) fibers, glass fibers, carbon fibers, silicon carbide fibers, alumina fibers, Examples thereof include inorganic fibers such as Tyranno fiber, basalt fiber, and ceramic fiber, metal fibers such as stainless fiber and steel fiber, and reinforcing fibers using boron fiber, natural fiber, modified natural fiber, and the like as fibers. Among them, carbon fiber is particularly lightweight among these reinforcing fibers, and has particularly excellent properties in specific strength and specific modulus, and is also excellent in heat resistance and chemical resistance. It is suitable for members such as automobile panels that are desired to be made. Among these, PAN-based carbon fibers that can easily obtain high-strength carbon fibers are preferable.

  Examples of the matrix resin used in the prepreg substrate of the present invention include, for example, thermosetting resins such as epoxy, unsaturated polyester, vinyl ester, phenol, epoxy acrylate, urethane acrylate, phenoxy, urethane, bismaleimide, and cyanate ester, Polyamide, polyacetal, polysulfone, ABS, acrylic, polyester such as polybutylene terephthalate and polyethylene terephthalate, polyolefin such as polyethylene and polypropylene, polyphenylene sulfide, polyetherimide, polyketone, polyetherketone, polyetheretherketone, liquid crystal polymer, chloride Examples thereof include thermoplastic resins such as fluororesin such as vinyl and polytetrafluoroethylene, and silicone. Among these, it is particularly preferable to use a thermosetting resin. Since the matrix resin is a thermosetting resin, the cut prepreg base material has tackiness at room temperature, so when the base material is laminated, it is integrated with the upper and lower base materials by adhesion, It can shape | mold, keeping the laminated structure as it was.

More preferably, among thermosetting resins, epoxy, unsaturated polyester, vinyl ester, phenol, and the like, and mixed resins thereof are preferable. The resin viscosity at normal temperature (25 ° C.) of these resins is preferably 1 × 10 ⁶ Pa · s or less, and within this range, a prepreg base material having tackiness and draping properties suitable for the present invention. Can be obtained. Among them, epoxy is most excellent in mechanical properties as a fiber reinforced plastic obtained in combination with carbon fiber.

  In the present invention, the thermosetting resin used for the prepreg base material is preferably produced with a minimum viscosity of 0.1 to 100 Pa · s based on dynamic viscoelasticity measurement (DMA). More preferably, it is 0.1-10 Pa.s. When the minimum viscosity is less than 0.1 Pa · s, only the resin flows during pressurization, and the reinforcing fiber may not be sufficiently filled up to the tip of the protrusion. On the other hand, when the viscosity is higher than 100 Pa · s, the fluidity of the resin is poor, and thus the reinforcing fibers and the resin may not be sufficiently filled up to the tip of the protrusion. The minimum viscosity due to DMA in the present invention is a rotational viscometer, using parallel plates with a radius of 20 mm, a distance between parallel plates of 1 mm, a measurement start temperature of 40 ° C., and a temperature increase rate of 1.5 ° C./min. Measured under the condition of a measurement frequency of 0.5 Hz, the value of the lowest viscosity observed.

  Moreover, the cut prepreg base material of the present invention may be in close contact with the tape-shaped support. The base material into which the cut is inserted can maintain its form even if all the fibers are cut by the cut, and there is no problem that the fiber falls off during shaping. More preferably, the matrix resin is a thermosetting resin having tackiness. Here, the tape-like support includes papers such as kraft paper, polymer films such as polyethylene / polypropylene, metal foils such as aluminum and the like, and in order to obtain releasability from the resin, silicone. A surface or a “Teflon (registered trademark)” release agent or metal deposition may be applied to the surface.

  The fiber reinforced plastic manufactured according to the present invention is suitably used for applications requiring strength, rigidity and light weight, and is used for bicycle articles such as frames, saddles, poles, forks, cranks, arms, handles, golf shafts and heads. Sports members such as rackets, outer panels such as doors, reinforcement materials such as inner panels, seat frames / panels, members, beams, and other automotive parts, doublers, window frames, ribs, stringers, spars, frames, beams, There are aircraft parts such as skins and industrial parts such as robot arms and forks. Especially, in addition to intensity | strength and lightweight, a member shape is complicated and it can apply preferably to the aircraft member or motor vehicle member which requires shape followability like this material.

    Hereinafter, the present invention will be described more specifically with reference to examples.

(Example 1)
<Preparation of prepreg base material>
An epoxy resin composition was obtained by the following procedure, and applied on a release paper using a reverse roll coater to prepare a resin film.

  (A) Epoxy resin (“Epicoat (registered trademark)” 828: 30 parts by weight, Epicoat 1001: 35 parts by weight, Epicoat 154: 35 parts by weight) manufactured by Japan Epoxy Resin Co., Ltd., and thermoplastic resin polyvinyl formal (Chisso ( "Vinylec (registered trademark)" K) 5 parts by weight was stirred for 1 to 3 hours while heating at 150 to 190 ° C to uniformly dissolve polyvinyl formal.

  (B) After lowering the resin temperature to 55 to 65 ° C., 3.5 parts by weight of a curing agent dicyandiamide (DICY7 manufactured by Japan Epoxy Resin Co., Ltd.) and a curing accelerator 3- (3,4-dichlorophenyl) -1, 4 parts by weight of 1-dimethylurea (DCU99 manufactured by Hodogaya Chemical Co., Ltd.) was added, kneaded at the temperature for 30 to 40 minutes, and then taken out from the kneader to obtain an epoxy resin composition. The exothermic peak temperature Tp according to DSC of the obtained epoxy resin composition was 152 ° C. As a measuring apparatus, “DSC2910” manufactured by TA Instruments Co., Ltd. was used, and the measurement was performed under a temperature rising rate of 10 ° C./min. Further, the minimum viscosity due to DMA was 0.5 Pa · s. As a measuring device, a dynamic viscoelasticity measuring device “ARES” manufactured by T.A. Instruments Co., Ltd. was used under the conditions of a temperature rising rate of 1.5 ° C./min, a frequency of 0.5 Hz, and a parallel plate (radius 20 mm). The minimum viscosity was determined from the temperature-viscosity relationship curve.

Next, the carbon fiber (tensile strength 4,900 MPa, tensile elastic modulus 235 GPa) aligned in one direction in a sheet shape is laminated with two resin films from both sides of the carbon fiber, heated and pressurized to impregnate the resin composition. Thus, a unidirectional prepreg base material having a carbon fiber basis weight of 150 g / m ² and a resin weight fraction of 33% (corresponding to a fiber volume content Vf of 58%) was produced.

<Production of cut prepreg base material>
A notch prepreg base material having regular notches at regular intervals was obtained by inserting notches as shown in FIG. 15 into the prepreg base material using an automatic cutter. The cutting direction is the fiber orthogonal direction 2, the cutting length W is 10.1 mm (that is, Ws = 10.1 mm), and the interval L (fiber length) is 30 mm. As shown in FIG. 15, adjacent incision rows 7a and 7b are geometrically equivalent when moved 10 mm in the direction perpendicular to the fiber. In addition, there are pairs of cuts 7a and 7c and 7b and 7d in the cut rows that are paired in the fiber longitudinal direction, and there are two patterns of cut rows. Furthermore, the range of 5 in which the cuts in the adjacent rows cut into each other is 0.1 mm. The cutting direction is the fiber orthogonal direction 2, the cutting length W is 10.1 mm (that is, Ws = 10.1 mm), and the interval L (fiber length) is 30 mm. As shown in FIG. 15, the adjacent cut rows 7a and 7b are geometrically equivalent when moved 10 mm in the direction perpendicular to the fiber. In addition, there are pairs of cuts 7a and 7c and 7b and 7d in the cut rows that are paired in the fiber longitudinal direction, and there are two patterns of cut rows. Furthermore, the range of 5 in which the cuts in adjacent rows are cut each other is 0.1 mm.

<Molding of fiber reinforced plastic>
As shown in FIG. 16, a fiber reinforced plastic 16 having a stepped portion 12c provided in a lid shape of a lunch box with a standing wall height of 20 mm having a projected area of 300 × 200 mm was molded.

(1) Laminating Step First, as the thin-walled portion 12b, the rectangular longitudinal direction is set to 0 °, and the carbon fiber orientation direction (0 ° direction) is shifted to the right by 45 degrees from the carbon fiber orientation direction (45 ° direction). ) And the carbon fiber orientation orthogonal direction (90 ° direction), the cut prepreg base material was cut into a rectangle (length 270 mm × width 180 mm), and [45/0 / −45 / 90/90 / −45 / 0 / 45] was laminated.

  Next, as the stepped portion 12c, similarly, the cut prepreg base material is cut into a rectangular shape (length: 140 mm × width: 180 mm) and laminated in a [45/0] stacked configuration, and the cut prepreg base material is rectangular (length: 135 mm). X Width 180 mm) and two layers are laminated in a [−45/90] laminated structure, and the cut prepreg base material is cut out into a rectangle (length 130 mm × width 180 mm) and [90 / −45] laminated structure 2 The cut prepreg base material was cut into a rectangle (length: 125 mm × width: 180 mm), and one piece was laminated in a laminated configuration of [0], each of which was laminated based on one end of the thin portion 12b.

  Finally, as the thick portion 12a, the cut prepreg base material was cut into a rectangle (length 120 mm × width 180 mm), and one piece was laminated based on one end portion of the thin portion 12b with the laminated structure [45].

  That is, the number of stacked thick portions 12a (16, length 125 mm × width 180 mm), the number of thin portions 12b (8, length 130 mm × width 180 mm), and a step portion (length 15 mm × width 180 mm) therebetween. The number of laminated layers is reduced by 1 to 2 in a tapered shape, and both surfaces (length 270 mm × width 180 mm) of the laminated body are covered with the same cut prepreg base material [45].

(2) Molding step The molding die is composed of a movable die and a fixed die, and the cavity when the two dies are combined is the same as the outer shape of the final molded product, and the step is provided in the molding die. The mold is installed in a press machine, and the movable mold moves up and down. The temperature was controlled at 150 ° C. so that the temperature T1 of the mold in the molding step was substantially the same as the exothermic peak temperature Tp due to DSC of the epoxy resin composition used for the prepreg substrate. Adhesiveness of the matrix resin at the location where the laminate is positioned on the fixed mold, positioned so that the step of the laminate corresponds to the step of the mold, and displayed in advance on the mold The laminate was fixed with and clamped. The press pressure at this time was adjusted to 6 MPa by dividing the pressure divided by an area of 300 × 200 mm. Since the laminated body is prepared smaller than the cavity, there is an advantage that it does not take time to arrange in the mold. It was heated and pressurized in the mold for 30 minutes.

(3) Demolding process After heating and pressurizing, the mold was opened at 150 ° C. without lowering the temperature T2 of the mold from T1, and the fiber reinforced plastic 16 was taken out.

  Although the laminate was smaller than the cavity, the carbon fiber flowed to every corner, and a fiber reinforced plastic having a step portion along the outer shape of the mold could be obtained. In addition to the stepped portion, the cut prepreg base material extends in both the thick and thin portions, the cut opening existing between the fiber bundle ends divided by the cut, the fiber length Lc is 30 mm, the width A strip-shaped fiber bundle having a distribution of Ws of about 11 to 15 mm was distributed as a whole. In particular, in the lid shape of a lunch box with such a stepped portion, the fiber always stretches in the molding using the continuous fiber base material, so that the pre-forming of the laminate along the forming mold in advance is performed as a shaping process. It is essential, and even if pre-shaped, it is extremely difficult to eliminate the deterioration of surface quality due to wrinkles and fiber tension. Like the present invention, it is a feature of the present invention that a high-quality fiber-reinforced plastic can be easily obtained from a laminate laminated in a flat plate shape, and in this example, since the fiber-reinforced plastic was obtained in a trimless manner, The effect of man-hour reduction is extremely large.

(Example 2)
Pellets of copolymerized polyamide resin (“Amilan” (registered trademark) CM4000 manufactured by Toray Industries, Inc., melting point 155 ° C.) were processed into a film having a thickness of 34 μm with a flat plate press heated at 200 ° C. The viscosity of the polyamide resin in an atmosphere at 25 ° C. was a solid and could not be measured, and the substrate had no tackiness. A prepreg base material was produced in the same manner as in Example 1 except that the release paper was not used, and a cut was introduced into the prepreg base material in the same manner as in Example 1 to obtain a cut prepreg base material.

(1) Lamination process It carried out similarly to Example 1, and obtained the laminated body. However, since the prepreg base material has no tack, in the laminating step, the cut prepreg base materials were temporarily fixed using an iron to integrate the laminated body.

(1b) Preheating process In addition to Example 1, the laminated body was heated in an oven at 200 ° C to soften the matrix resin in advance.

(2) Molding step The temperature of a double-sided mold similar to that in Example 1 is controlled to 70 ° C, and when the surface temperature reaches 160 ° C, the preheating step is finished and taken out from the oven, and the laminate is placed on the stationary mold. Since the matrix resin is softened in the preheating step of (1b) above, the adhesive is adhesive at a high temperature because the step portion of the laminate is positioned so as to correspond to the step portion of the mold. Then, the laminate was fixed to the place where it was preliminarily displayed on the mold due to its adhesiveness, and immediately clamped. The press pressure at this time was adjusted to 6 MPa by dividing the pressure divided by an area of 300 × 200 mm. Since the laminate was made smaller than the cavity, it could be placed easily and cold-pressed before the temperature of the laminate fell.

(3) Demolding process After cooling and pressurizing in the mold for 90 seconds, the mold was removed. Since it was a cold press, it was possible to remove the mold very easily.

  Although the laminate was smaller than the cavity, the carbon fiber flowed to every corner, and a fiber reinforced plastic having a step portion along the outer shape of the mold could be obtained. In addition to the stepped portion, the cut prepreg base material extends in both the thick and thin portions, the cut opening existing between the fiber bundle ends divided by the cut, the fiber length Lc is 30 mm, the width A strip-shaped fiber bundle having a distribution of Ws of about 11 to 15 mm was distributed as a whole. Since some voids were observed between the layers, although it was possible that the mechanical properties were not higher than those of Example 1, it was possible to perform cold press molding with a very short cycle time using the present invention.

(Example 3)
In the same manner as in Example 1, a prepreg base material was produced. A straight notch in the direction of 10 ° was continuously inserted into the prepreg base material from the fiber as shown in FIG. 10 using an automatic cutting machine to obtain a cut prepreg base material.

(1) Laminating process Two prepreg base materials are laminated on the front and back so that the incision prepreg base material is the same in fiber direction and the incision intersects (in the direction of 10 ° and −10 °), and the prepreg is formed by continuous incision. The base material was prevented from falling apart.

  As the thin-walled portion 12b, four sets of this two-layer laminate are cut into rectangles (length 270 mm × width 180 mm) in the orientation direction (0 ° direction) of the carbon fibers and the orientation orthogonal direction (90 ° direction) of the carbon fibers, Eight sheets were stacked in a stacked configuration of [0/0/90/90/0/0/90/90].

  Next, as the thick portion 12a, four sets of the two-layer laminate are cut into rectangles (length 125 mm × width 180 mm), and are thin-walled with a laminated configuration of [90/90/0/0/90/90/0/0]. Eight sheets were laminated based on one end portion of the portion 12b.

  That is, the number of stacked thick portions 12a (16, length 125 mm × width 180 mm), the number of thin portions 12b (8, length 145 mm × width 180 mm), and the stepped portion (length 0 mm × width 180 mm) all at once. The number of stacks is reduced by four, and only one surface (length 270 mm × width 180 mm) of the stack is covered with the same cut prepreg base material [0].

(1a) Deaeration step In addition to Example 1, the laminated laminate was covered with a stretchable film and sealed, then degassed by depressurizing the inside, and the air or matrix caught during lamination Moisture absorbed by the resin was removed from the laminate.

(1b) Preheating step In addition to Example 1, the laminate was heated in an oven to 70 ° C to soften the matrix resin in advance.

  Otherwise, molding was performed in the same manner as in Example 1 to obtain a fiber-reinforced plastic.

  The obtained fiber reinforced plastic was molded into a cavity-like shape as in Example 1. Even in the cutting of the prepreg base material on the surface of fiber reinforced plastic, there is almost no notch opening, the area where the reinforcing fiber is not present and the resin is rich, or the area where the reinforcing fiber of the adjacent layer is peeking The appearance quality and smoothness were almost zero. The fiber direction is rotating from the time when the laminate is arranged, and the rotation is filled with the cut opening, resulting in a smooth fiber reinforced plastic. In particular, this effect is more prominently expressed by the (1b) preheating step. It was speculated. In addition, no voids were observed between the layers, and it is considered that (1a) the deaeration process increased the certainty of the void suppression effect.

Example 4
A prepreg base material was prepared in the same manner as in Example 1. In this prepreg base material, an automatic cutting machine is used to intermittently insert 1 mm straight cuts in the direction of 11 ° from the fibers as shown in FIG. 11, thereby cutting the cuts in the vertical direction of the reinforcing fibers. The projected length Ws projected was 0.34 mm. The fibers were cut by the pair of cuts 4d ₁ and 4d ₂ , and the fiber length L was 30 mm over the entire surface of the obtained cut prepreg base material.

  A fiber-reinforced plastic was obtained through the laminating step, the forming step, and the demolding step in the same manner as in Example 1 except that the cut prepreg base material thus obtained was used.

  In the obtained fiber reinforced plastic, as shown in FIG. 14 (b), the fiber 3 is slightly swollen and the cut opening 18 is filled, and the cut opening 18 is hardly seen on the surface. It was possible to obtain a fiber reinforced plastic having good appearance quality and smoothness at a level that is not.

(Example 5)
Using a mold as shown in FIG. 4, a double contour part (R800 mm sphere protruded from the circle with a diameter of 350 mm as a boundary line on a 500 × 500 mm square flat plate as shown in FIG. 1 (c). Shape) and a fiber reinforced plastic provided with a step portion in the center.

(1) Lamination process A prepreg base material was produced in the same manner as in Example 1, and was first cut into squares of length 500 × width 500 mm in the directions of 0 °, 45 ° and 90 °. A notch similar to that of Example 1 was made in the center of the square in a range of 360 mm in diameter to form a region composed of only reinforcing fibers having a fiber length of substantially 25 mm. Furthermore, what cut the prepreg which put the incision into the half size (length 250mm x width 500mm) was also prepared.

As the thin-walled portion 12b, eight prepreg base materials that were partially cut were laminated in a square shape of length 500 × width 500 mm in a [45/0 / −45 / 90] _1S laminated structure.

Next, as a thick portion 12a, a prepreg base material that is partially cut and cut in half is formed into a rectangular shape having a length of 250 mm and a width of 500 mm with a [45/0 / −45 / 90] _1S laminated structure, and a thin portion Eight sheets were laminated based on one end of 12b.

  That is, the number of stacked thick portions 12a (16, length 250 mm × width 500 mm), the number of thin portions 12b (8, length 250 mm × width 500 mm), and the stepped portion (length 0 mm × width 500 mm) all at once. The number of stacks is reduced by 4 and only one surface (length 500 mm × width 500 mm) of the stack is covered with the same partially cut prepreg base material [45]. Moreover, the area | region comprised only with a 25 mm reinforcing fiber has overlapped each layer, and the discontinuous part 37 was formed in the range of the center part diameter 360mm of a laminated body like FIG. 1 a).

(1b) Preheating step The obtained laminate was heated to 70 ° C in an oven to soften the matrix resin in advance, and immediately set in a positioning clamp described later so that the temperature change was minimized.

(2) Molding Step The molding die in FIG. 4 is formed from a frame-shaped laminated body positioning clamp (laminated body fixing jig) 28d supported by a spring 27 together with a movable mold 28a and a fixed mold 28b. The fixed die 28b is a die that determines the shape of only the double contour portion 25, and the clamp 28d is a frame shape obtained by hollowing a flat plate so that the fixed die 28b can access the movable die 28a, and determines the shape of the flat plate portion. The type to be. The clamp 28d is supported by a spring, and when the mold is open, it is above the fixed mold 28b and below the movable mold 28a. The temperature of the entire mold was controlled at 150 ° C. in the same manner as in Example 1, and the laminate 12 was mechanically gripped and fixed on the clamp 28d in a dotted manner and positioned at a pre-displayed location. Next, the movable die 28a was lowered, and the stepped portion 12c was fixed at this stage, and became the starting point for the extension of the laminate 12. Further, by pushing the movable mold 28a, the shape of the double contour part 25 was determined by the fixed mold 28b and the movable mold 28a, and the cavity of the molding mold was closed. The pressing pressure at this time was adjusted so that the pressure divided by an area of 500 × 500 mm was 6 MPa. In the same manner as in Example 1, it was heated and pressurized in a mold for 30 minutes.

  Others were obtained in the same manner as in Example 1 to obtain a fiber reinforced plastic.

  The obtained reinforced fiber plastic had a double contour portion along the outer shape of the mold. Similar to Example 1, the surface quality is good, only the double contour part is elongated, the notch opening existing between the fiber bundle end parts divided by the notch, the fiber length Lc is 30 mm, and the width Ws is 11 Strip-like fiber bundles having a distribution of about ˜15 mm were concentrated and distributed in the double contour portion. Moreover, the peripheral part of the laminated body 12 hardly flowed, and it was shape | molded according to the cavity. (1b) By the preheating process, it was possible to easily follow a complicated shape such as a double contour portion.

(Example 6)
Using a mold as shown in FIG. 5, a lid-shaped fiber-reinforced plastic for an elliptical lunch box was molded.

(1) Lamination process The laminated body 12 was produced like Example 4. As shown in FIG.

(2) Molding Step As a molding die, a single-sided die 28c having a convex portion (double contour portion 25) shaped like the final shape shown in FIG. 5 and a groove 33 around it was prepared. A sealant 31 was disposed around the fixed mold 28c, and a tube connected to a vacuum pump was placed on the sealant 31 to form a deaeration port 26, which was heated in an oven controlled at 150 ° C. When the fixed die 28c becomes constant at 150 ° C., the laminated body 12 smaller than the surface area of the convex portion is positioned and arranged so that the stepped portion of the laminated body corresponds to the stepped portion of the fixed die, and is previously placed on the mold. The laminated body is fixed with the adhesiveness of the matrix resin at the position to be displayed, covered with a stretchable silicone rubber film 32 which is a movable mold, and closely adhered with a sealant 31, and sealed between the film 32 and the mold 28c. A space 30 was formed. At the same time, the vacuum pump is activated, the vacuum 38 is performed, the exhaust air is exhausted from the deaeration port 26, and the laminate 12 softened by the pressure difference between the outside air and the sealed space 30 (about 0.1 MPa) is extended to expand the mold 28c. To form a hot drape. Due to the presence of the grooves 33, the film 32 was firmly in the shape up to the base of the convex portion, and pressure was firmly applied to the base of the convex portion. After leaving in the oven for 30 minutes, the entire molding apparatus was taken out of the oven, the film 32 was broken, and the fiber reinforced plastic was removed from the mold 28c.

  Although the laminated body 12 had a flat plate shape smaller than the obtained fiber reinforced plastic, a fiber reinforced plastic having a shape like an elliptical lunch box lid could be obtained as designed. Since the molding pressure was smaller than in Examples 1 and 2, the double contour part was clearly transferred, although it was not elongated greatly, and a fiber-reinforced plastic with good surface quality could be obtained.

(Example 7)
Using the same prepreg base material as in Example 1, a 1 mm straight cut (Ws is 0.34 mm) is made in the direction of 20 ° from the fiber as shown in FIG. A cut prepreg base material having a fiber length L of 30 mm over the entire surface was prepared. The following steps were added to Example 1 to obtain a fiber reinforced plastic similar to Example 1.

(1a) Deaeration process After the laminated laminate is covered with a stretchable film and sealed, the inside is depressurized and degassed, and air that has been bitten when laminated, moisture absorbed by the matrix resin, etc. Removed from the laminate. This step was performed in an oven having a preheating temperature of 70 ° C. in the preheating step (1b) described later.

(1b) Preheating step The laminated body is heated to 70 ° C. in an oven to soften the matrix resin in advance, and the laminated body is folded at the R portion as shown in FIG. Pre-shaped to a simple shape.

  Otherwise, molding was performed in the same manner as in Example 1 to obtain a fiber-reinforced plastic.

  The obtained fiber reinforced plastic 16 was satisfactorily filled with fibers including two standing surfaces as shown in FIG. Since two standing surfaces were formed by pre-shaping, the extending direction of the laminated body 12 was controlled, and a fiber-reinforced plastic 16 having a more stable quality was obtained. Further, when the R-section cross-section 40 at the corner of the standing surface and the plane filled at the time of molding was observed, a laminated structure (including some undulations) that was not different from the plane was formed despite being filled at the time of molding. . In addition, no voids were observed between the layers, and it is considered that (1a) the deaeration process (in addition, (1b) the preheating process) increases the certainty of the void suppression effect.

(Reference Example 1)
The fiber reinforced plastic flat plate of Example 1 demonstrated that the fiber reinforced plastic of Example 1 developed excellent mechanical properties. A prepreg base material was prepared in the same manner as in Example 1, and a cut was introduced to prepare a cut prepreg base material. Each of the carbon fiber was cut into a size of 250 × 250 mm in the orientation direction of the carbon fiber (0 ° direction) and the direction shifted 45 degrees to the right from the orientation direction of the carbon fiber (45 ° direction). The cut prepreg base material was laminated in a pseudo isotropic manner with 16 layers ([45/0 / −45 / 90] _2S ) to obtain a laminate.

  Furthermore, after arrange | positioning in the approximate center part on the flat plate metal mold | die which has a cavity of 300x300mm using said laminated body, it is 150 degreeC x 30 minutes under the pressurization of 6 MPa with a heating type press molding machine. The plate was hardened under the above conditions to obtain a flat fiber reinforced plastic of 300 × 300 mm.

  A tensile strength test piece having a length of 250 ± 1 mm and a width of 25 ± 0.2 mm was cut out from the obtained flat fiber-reinforced plastic. According to the test method specified in JIS K-7073 (1998), the tensile strength was measured at a crosshead speed of 2.0 mm / min with a distance between the gauge points of 150 mm. In this reference example, an Instron (registered trademark) universal testing machine 4208 type was used as a testing machine. The number of test pieces measured was n = 5, and the average value was the tensile strength. Further, a standard deviation was calculated from the measured value, and the standard deviation was divided by an average value, thereby calculating a coefficient of variation (CV value) as an index of variation. The tensile elastic modulus was 43 GPa, the tensile strength was as high as 370 MPa, and the CV value was 3%, which was a very small variation.

  In the fiber reinforced plastic, the fibers are evenly flowed to the end, and like the first embodiment, a strip-like fiber bundle having a distribution with a fiber length Lc of 30 mm and a width Ws of about 11 to 15 mm is almost the entire surface. Since it was evenly distributed, it was expected that the fiber reinforced plastic obtained in Example 1 would also exhibit excellent mechanical properties.

(Reference Example 2)
The fiber reinforced plastic of Example 3 demonstrated high mechanical properties with a fiber reinforced plastic flat plate. In the same manner as in Example 3, a two-layer laminate was obtained. From this two-layer laminate, cut into a size of 250 × 250 mm in each of a carbon fiber orientation direction (0 ° direction) and a direction shifted to the right by 45 degrees from the carbon fiber orientation direction (45 ° direction). A layer stack is laminated in a pseudo isotropic manner ([45/45/0/0 / -45 / -45 / 90/90] _S ) in the direction of each of the eight sheets, and a 250 × 250 mm having a notch on the entire surface. A laminate was obtained.

  The laminate thus obtained was hot press molded in the same manner as in Reference Example 1 to obtain a flat fiber reinforced plastic. The obtained fiber reinforced plastic was subjected to a tensile test in the same manner as in Reference Example 1. The tensile modulus was 46 GPa and the tensile strength was as high as 470 MPa, and the CV value was 4%, which was very small.

  In the fiber reinforced plastic, the fibers are flowing evenly to the end, almost no cut opening is seen on the surface, and the fiber direction is the same as in Example 3 in the state of rotation from the time when the laminate was placed. For this reason, the fiber reinforced plastic obtained in Example 3 was also expected to exhibit excellent mechanical properties.

(Reference Example 3)
It was demonstrated on a flat plate that the fiber reinforced plastic of Example 4 has high mechanical properties. A cut prepreg base material was obtained in the same manner as in Example 4, cut out in the same manner as in Reference Example 1, laminated, and hot press molded. When the obtained fiber reinforced plastic was subjected to a tensile test in the same manner as in Reference Example 1, the tensile elastic modulus was 46 GPa, the tensile strength was as high as 620 MPa, and the CV value was 4%, which was a very small variation. . Fiber reinforced plastic has fibers evenly flowing to the end, and while the fibers swell slightly, it fills the notch opening, almost no notch opening is seen on the surface, even the incision is recognized Since the appearance of the non-sticking is the same as in Example 4, it was expected that the fiber-reinforced plastic obtained in Example 4 would also exhibit excellent mechanical properties.

(Comparative Example 1)
The fiber reinforced plastic provided with the step part shown in FIG. 16 as in Example 1 was molded with a continuous fiber prepreg base material. In the same manner as in Example 1, a prepreg base material was produced. Without making a notch in the prepreg base material, the laminate was obtained in the same manner as in Example 1 and molded.

  In the obtained fiber reinforced plastic, the surface of the stepped portion on the standing wall was particularly rough, and the fiber reinforced plastic was not completely adhered to the mold. This was presumed to be because the continuous carbon fibers were stretched and the laminate could not be stretched and did not conform to the mold.

(Comparative Example 2)
The same fiber reinforced plastic provided with the step shown in FIG. 16 as in Example 1 was molded with an SMC base material. The following SMC was used. 100 parts by weight of vinyl ester resin (manufactured by Dow Chemical Co., Ltd., Delaken 790) as a matrix resin, 1 part by weight of tert-butyl peroxybenzoate (manufactured by NOF Corporation, Perbutyl Z) as a curing agent, internally separated Using 2 parts by weight of zinc stearate (manufactured by Sakai Chemical Industry Co., Ltd., SZ-2000) as a mold, and 4 parts by weight of magnesium oxide (Kyowa Chemical Industry Co., Ltd., MgO # 40) as a thickener, They were thoroughly mixed and stirred to obtain a resin paste. The resin paste was applied onto a polypropylene release film with a doctor blade. From there, carbon fiber bundles (tensile strength 4,900 MPa, tensile elastic modulus 235 GPa, 12,000 fibers) cut to a length of 25 mm are uniformly dropped and dispersed so that the weight per unit area is 500 g / m ^2. did. Further, it was sandwiched between the other polypropylene film coated with the resin paste with the resin paste side inward. The volume content Vf of the carbon fiber with respect to the SMC sheet was 40%. The obtained sheet was allowed to stand at 40 ° C. for 24 hours, thereby sufficiently thickening the resin paste to obtain an SMC sheet. This SMC sheet was cut into a rectangle of 270 × 180 mm, and three sheets were laminated to obtain a laminate. Thereafter, molding was performed in the same manner as in Example 1 to obtain a fiber-reinforced plastic.

  In the obtained fiber reinforced plastic, fibers sufficiently flowed to the end of the cavity. Although there was no warp, some sink marks due to the density of the fibers were observed on the surface. Further, since Vf was 40%, it was estimated that the strength was not as high as that of Example 1.

It is a perspective view which shows an example of the manufacturing method of the fiber reinforced plastic of this invention. It is sectional drawing which shows an example of the mechanism of the flow of the laminated body used for this invention. It is the top view and sectional drawing which show an example of the laminated body used for this invention. It is sectional drawing which shows an example of the manufacturing method of the fiber reinforced plastics of this invention. It is the top view and sectional drawing which show an example of the manufacturing method of the fiber reinforced plastics of this invention. It is an enlarged plan view which shows an example of the cutting prepreg base material used for this invention. It is a top view which shows the example of the cutting prepreg base material used for this invention. It is a top view which shows the example of the cutting positional relationship of the laminated body used for this invention. It is the top view and sectional drawing which show an example of the mode of expansion | extension of the laminated body used for this invention. It is an enlarged plan view which shows an example of the cutting prepreg base material used for this invention. It is an enlarged plan view which shows an example of the cutting prepreg base material used for this invention. It is a top view which shows the example of the cutting prepreg base material used for this invention. It is the top view and sectional drawing which show an example of the mode of expansion | extension of the laminated body used for this invention. It is a top view which shows an example of the mode of the expansion | extension of the laminated body used for this invention. It is an enlarged plan view which shows an example of the cutting prepreg base material used for this invention. It is the schematic which shows an example of the fiber reinforced plastic manufactured by this invention. It is the schematic which shows an example of the manufacturing method of the fiber reinforced plastics of this invention.

Explanation of symbols

1: Fiber longitudinal direction 2: Fiber orthogonal direction 3: Reinforcing fiber 4: Discontinuous end (cutting) of reinforcing fiber
4a: cut in layer a 4b: cut in layer b 4c: continuous cut 4d (4d ₁ , 4d ₂ ): intermittent cut 5: mutually cut width 6: pair in the fiber direction Spacing L between geometric centers of cut (fiber length L)
7: Intermittent cut row 7a: First intermittent cut row 7b: Second intermittent cut row 7c: Third intermittent cut row 7d: Fourth Intermittent cut row 8: Geometric center of cut 8a: Geometric center of cut of layer a 8b: Geometric center of cut of layer b 9: Projected length of the cut projected in the vertical direction of the reinforcing fiber Ws
10: Notched prepreg base material 10a: Notched prepreg base material 10b with incision on the entire surface: Notched prepreg base material 10c with notch in part: Discontinuous end 11 of prepreg: Continuous fiber Prepreg base material 12: Laminated body 12a: Thick portion 12b: Thin portion 12c: Step portion 13: Pressure applied to the laminated body 14: Resin flow 15: Opening of discontinuous ends of reinforcing fibers 16: Fiber reinforced plastic 17: No Continuous fiber layer 18: region where no reinforcing fiber exists (cut opening)
19: Adjacent layer 20: Resin rich portion 21: Layer waviness 22: Discontinuous end of reinforcing fiber 23: Angle Θ between cut and fiber direction
24: rotation of reinforcing fiber 25: double contour portion 26: deaeration port 27: spring 28: molding die 28a: movable die 28b, 28c: fixed die 28d: clamp 29 for positioning the laminate, 30: cavity 31: sealant 32 : Stretch film 33: Groove 34: Base material 35 in which two layers of cut prepreg base material are laminated: Area surrounded by two pairs of fiber bundle splitting portions (strip-shaped fiber bundle)
36: Convex shape 37: Cut section 38 formed by laminating only cut prepreg base materials in which fibers are cut to a length of 10 to 100 mm: Depressurization

Claims (14)

A method for producing a fiber reinforced plastic having a stepped portion having a different plate thickness by press-molding a laminate of a prepreg base material comprising a reinforced fiber aligned in one direction and a matrix resin, As the prepreg base material, at least the following (1) to (1) are used by using a cut prepreg base material in which at least some of the reinforcing fibers are divided into a length of 10 to 100 mm by a plurality of incisions in a direction crossing the reinforcing fibers. A method for producing a fiber reinforced plastic, wherein the fiber reinforced plastic is molded through the steps of 3).
(1) When obtaining a laminate by laminating a plurality of prepreg substrates including at least a cut prepreg substrate, at least a part of the laminate and a thick part having a large number of laminated prepreg substrates, and a prepreg Lamination process (2) for laminating a thin-walled portion with a small number of substrate layers and a stepped portion that is a boundary between the thick-walled portion and the thin-walled portion to obtain a flat laminate having different plate thicknesses When the laminate is pressed against a mold and cured or solidified to form a fiber reinforced plastic, the laminate is positioned so that the step portion of the laminate corresponds to the step portion provided in the mold. Forming the mold, and extending at least one of the thick part, the thin part, or the step part of the laminate, and filling each of the thick part, the thin part, and the step part of the mold. (3) The fiber strength from the mold Demolding step of taking out the plastic In the molding step (2), the means for positioning the laminate to the molding die is mechanically held and fixed at the place where the mold or the laminate fixing jig is displayed in advance, or The method for producing a fiber-reinforced plastic according to claim 1, wherein the fixing is performed with the adhesive property of the matrix resin. The incision of the incision prepreg base material is linear, the incision length W is 30 μm to 100 mm, and the absolute value of the angle Θ formed by the incision with the reinforcing fiber is in the range of 2 to 15 °. The manufacturing method of the fiber reinforced plastics of Claim 1 or 2 arrange | positioned intermittently and periodically. In the laminating step (1), the laminated body is laminated so that the stepped portion is tapered, and the prepreg base material on both surfaces of the laminated body is replaced with a prepreg base material other than the prepreg base material on both surfaces. The manufacturing method of the fiber reinforced plastics of Claim 1 or 2 arrange | positioned so that it may cover. A cut prepreg base in which the fiber reinforced plastic has a shape having a double contour portion, and in the laminating step (1), at least a part of the laminate is cut into 10 to 100 mm in length by reinforcing fibers. In order to form a cut portion in which only the material is laminated, in the molding step (2), the cut portion is arranged in the double contour portion of the mold, and the cut portion is extended to double the cut portion. The manufacturing method of the fiber reinforced plastics in any one of Claims 1-4 shape | molded along a contour part. The manufacturing method of the fiber reinforced plastic in any one of Claims 1-5 which passes through the preheating process which heats a laminated body and softens a matrix resin prior to the shaping | molding process of said (2). The fiber-reinforced plastic according to any one of claims 1 to 6, which undergoes a degassing step (1a) for degassing the laminate prior to the molding step (2) or the preheating step (1b). Manufacturing method. The fiber reinforced plastic has a shape having a double contour portion, and in the preheating step (1b), the laminated body is pre-shaped into a simple shape having a single contour portion, and in the molding step (2) The manufacturing method of the fiber reinforced plastic of Claim 6 or 7 shape | molded in the shape which has a part. In the molding step (2), when the molding die is composed of at least a movable die and a stationary die, and the laminate is molded by pressing the movable die against the stationary die, the laminate first comes into contact with the molding die. The manufacturing method of the fiber reinforced plastics in any one of Claims 1-8 which arrange | positions a level | step-difference part at least. In the molding step (2), the mold is composed of at least a fixed mold and a movable mold made of a stretchable film, and the laminate is fixed by the differential pressure between the cavity formed by the stretchable film and the fixed mold and the outside air. The method for producing a fiber-reinforced plastic according to claim 9, wherein the fiber-reinforced plastic is molded by being pressed against a mold. The fiber according to any one of claims 6 to 10, wherein the matrix resin is a thermosetting resin, and the heating temperature in the preheating step (1b) is lower than the temperature of the mold in the molding step (2). A method of manufacturing reinforced plastics. The fiber reinforcement according to any one of claims 6 to 10, wherein the matrix resin is a thermoplastic resin, and the heating temperature in the preheating step (1b) is higher than the temperature of the mold in the molding step (2). Plastic manufacturing method. After the demolding step of (3), (4) a post-heating step of heating the fiber reinforced plastic to a temperature equal to or higher than the molding die temperature of the molding step of (2). The manufacturing method of the fiber reinforced plastic of description. The manufacturing method of the fiber reinforced plastics in any one of Claims 1-13 in which a laminated body is comprised only from a cutting prepreg base material.

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