JP2014173031A - Stampable molded article, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a stampable molded article which is obtained by using a material, that has excellent shapability when molded into a complicated shape by stamping molding, which can be molded in a short time and has excellent external appearance quality.SOLUTION: The stampable molded article comprises a laminated base material formed by stacking two or more prepregs, each of which contains one-way arrayed reinforcing fibers and a thermoplastic resin. The prepreg has incisions which are formed on the front surface thereof in such a direction that the incision has a crossing with the reinforcing fiber and each of which has the depth enough to cut the reinforcing fiber. The stampable molded article has smooth front and back surfaces. The method for producing the stampable molded article is also provided.

Description

  The present invention relates to a method for manufacturing a stampable molded product that is excellent in shaping into a complicated shape during stamping molding, can be molded in a short time, and has excellent appearance quality of a molded product.

  As a method for molding fiber-reinforced thermoplastics, continuous reinforcing fibers called prepregs are laminated with a base material impregnated with a thermoplastic resin, and further, they are heated or pressed with a press or the like. Most commonly, stamping molding is performed in which a laminated and integrated molding base material is shaped into a target shape by heating and pressing or cooling and pressing with a press or the like. The fiber reinforced plastic obtained in this way has excellent mechanical properties because it uses continuous reinforcing fibers. Further, by arranging the continuous reinforcing fibers regularly, it is possible to design the required mechanical properties, and the variation in the mechanical properties is small. However, since it is a continuous reinforcing fiber, it is difficult to form a complicated shape such as a three-dimensional shape, and it is mainly limited to members close to a planar shape.

  In order to solve this problem, the fiber length is cut to 5 mm or 10 mm to 100 mm, the fiber length and the fiber volume content are constant, and the fibers are isotropically maintained by orienting the fibers randomly in two dimensions. Random mats have been proposed. (For example, Patent Documents 1 and 2)

However, it is extremely difficult to maintain a constant fiber length and fiber volume content and to keep the fibers isotropic, and there is a problem that mechanical characteristics are uneven depending on the location and orientation. Furthermore, during preheating of the molding base material required at the time of stamping molding, thickness spots and fiber volume content spots resulting from dispersion spots of reinforcing fibers are generated, resulting in excessive heating and insufficient heating in the same molding base material.
It is assumed that the part with insufficient heating lacks fluidity and the part with excessive heating reaches the decomposition temperature of the thermoplastic resin. When stamping molding is performed in such a state, surface irregularities may occur on the molded body or whitening may occur.・ It may cause browning or deterioration of surface appearance. Such a case is not preferable because the operation range of the preheating process of the molded base material is narrowed.

  In order to solve the above-mentioned problems, Patent Document 3 is capable of forming in a short time by cutting into a prepreg composed of continuous fibers and a thermoplastic resin and optimizing the cutting shape, thereby providing excellent loading. Materials that exhibit shape and have high mechanical properties and small variations have been proposed.

  However, although the proposed method shows improvement in mechanical characteristics and variation, the fluidity to a complicated three-dimensional shape such as a thin rib or boss is insufficient in stamping. Furthermore, because the charge rate is low, the area of the part where the reinforcing fibers generated on the front and back surfaces of the molded body randomly flow is large, and the switching position with the part that maintains the fiber orientation derived from the laminated substrate on the front and back surfaces of the molded body is visible. Since there is a tendency to become a highly sited part, it was necessary to remodel in order to obtain a molded article having a good appearance.

JP 2013-010254 A JP 2013-011736 A JP 2009-286817 A

  The present invention solves the problems of the prior art as described above, easily follows complicated shapes such as ribs, bosses, etc., and the reinforcing fibers generated on the front and back surfaces of the molded body randomly flow. An object of the present invention is to improve the appearance of a stamped molded product by reducing the area and reducing the visibility of the switching position between the front and back surfaces of the molded body and the portion where the fiber orientation derived from the laminated base material is maintained.

  The present invention is formed by laminating a plurality of prepregs including a reinforcing fiber oriented in one direction and a thermoplastic resin, and having a depth of notch for cutting the reinforcing fiber in a direction crossing the reinforcing fiber on the surface. It is a stampable molded product made of a laminated base material, and is a stampable molded product with smooth front and back surfaces.

  The present invention solves the problems of the prior art as described above, easily follows complicated shapes such as ribs, bosses, etc., and the reinforcing fibers generated on the front and back surfaces of the molded body randomly flow. A stamping molded product can be obtained by reducing the area and reducing the visibility of the switching position between the front and back surfaces of the molded body and the portion where the fiber orientation derived from the laminated base material is maintained.

The figure which shows the prepreg which gave the notch | incision used except Examples 12 and 13 of this invention. The figure which shows the stamping molded object obtained in the Example of this invention.

  The stamping molded article of the present invention comprises a laminate of a plurality of prepregs that include reinforcing fibers oriented in one direction and a thermoplastic resin, and that have a depth of cut that cuts the reinforcing fibers in a direction crossing the reinforcing fibers on the surface. A stampable molded product made of a laminated base material formed in the above manner, and a stampable molded product having smooth front and back surfaces.

(Prepreg)
The prepreg that can be used in the stampable molded article of the present invention requires that the reinforcing fiber is cut by cutting. The length L of the cut reinforcing fiber is not particularly limited, but is preferably 5 mm or more and 100 mm or less from the viewpoint of mechanical properties and fluidity. In particular, in order to achieve both sufficient mechanical properties and flow to a thin portion such as a rib during stamping molding, the thickness is more preferably 10 mm or more and 50 mm or less.

Further, the fluidity at the time of stamping molding depends not only on the direction of cutting for cutting the reinforcing fiber and the angle θ formed by the reinforcing fiber, but also on the total length la of the cutting length per 1 m ² . The larger θ is, the smaller the shear force between the reinforcing fibers is, so the fluidity is higher, and the larger la is, the more the cut portion in the prepreg is, the higher the fluidity is. When the prepreg that can be used in the stampable molded article of the present invention is flat plate stamping, θ is preferably 25 ° or more, and la is preferably 10 m or more. Furthermore, in the case of stamping molding of complicated shapes such as ribs, θ is preferably 30 ° or more, and la is preferably 20 m or more.

Furthermore, the mechanical properties represented by the bending strength and the flexural modulus depend not only on the angle θ between the notch for cutting the reinforcing fiber and the reinforcing fiber but also on the total length la of the notch length per 1 m ² . It is known that the smaller the angle θ between the cut and the reinforcing fiber is, the higher the mechanical properties are (for example, Patent Document 3), and the smaller the la is, the fewer cut portions in the prepreg are, so that higher mechanical properties are obtained. For example, θ is preferably 70 ° or less and la is preferably 200 m or less in order to be used for a semi-structure member of an automobile. For use in structural members that require higher mechanical strength, θ is preferably 60 ° or less, and la is preferably 150 m or less.

When using a prepreg that has been cut into a prepreg that can be used in the stampable molded article of the present invention, the manufacturing time and the manufacturing cost are not only the angle θ between the cut and the reinforcing fiber cutting the reinforcing fiber, This greatly depends on the total sum la of the cutting length per 1 m ² . When θ is small and la is large, for example, when cutting with a cutting plotter, the time required for the cutting process becomes long. In addition, when the cut is processed by punching, not only the manufacturing cost of the punching blade is increased, but also a tear is easily generated in the direction of the reinforcing fiber when punching, and a sheet is lost between adjacent cuts. Therefore, θ is preferably 15 ° or more, and la is preferably 200 m or less. Further, in consideration of the lamination process after the cutting process, θ is preferably 30 ° or more, and la is more preferably 150 m or less. It is necessary to have a cut, but if it satisfies the range of the angle θ between the cut and the reinforcing fiber and the total length of the cut per 1 m ² , the length of the cut and the number of cuts Different prepregs may be laminated. At the time of stamping molding, it is preferable to increase θ and increase la in a thin and three-dimensional portion such as a boss or rib. On the other hand, it is preferable that θ is small and la is small in a portion where the flow is two-dimensional and the flow length is small and high mechanical properties are required.

  The prepreg that can be used in the stampable molded article of the present invention is preferably a fiber volume content Vf of the reinforcing fiber of 55% or less because sufficient fluidity can be obtained. The lower the value of Vf, the better the fluidity. However, if the value of Vf is less than 20%, the mechanical properties necessary for the structural material cannot be obtained. Considering the relationship between fluidity and mechanical properties, 20% to 55% is preferable. Such Vf value can be measured based on JIS K7075.

  As a prepreg that can be used in the stampable molded article of the present invention, when a prepreg having a cut is used, the strength tends to decrease as the thickness of the divided prepreg increases, and it is assumed that the prepreg is applied to a structural material. Therefore, the thickness of the prepreg is preferably 200 μm or less. On the other hand, if the thickness is less than 50 μm, it is difficult to handle the prepreg, and the number of prepregs to be laminated for making a laminated base material is very large, so the productivity is remarkably deteriorated. Therefore, it is preferable that it is 50 micrometers or more and 200 micrometers or less from a viewpoint of productivity.

  The type of reinforcing fiber that can be used in the stampable molded article of the present invention is not particularly limited, and inorganic fiber, organic fiber, metal fiber, or a hybrid fiber that combines these can be used. Examples of the inorganic fiber include carbon fiber, graphite fiber, silicon carbide fiber, alumina fiber, tungsten carbide fiber, boron fiber, and glass fiber. Examples of organic fibers include aramid fibers, high density polyethylene fibers, other general nylon fibers, and polyesters. Examples of the metal fibers include fibers such as stainless steel and iron, and may be carbon fibers coated with metal. Among these, carbon fibers are preferable in consideration of mechanical properties such as strength of the final molded product. Moreover, it is preferable that the average fiber diameter of a reinforced fiber is 1-50 micrometers, and it is more preferable that it is 5-20 micrometers.

  The stampable molded article of the present invention needs to use a thermoplastic resin. That is, in the case of a fiber reinforced plastic using discontinuous reinforcing fibers, in order to break so as to connect the ends of the reinforcing fibers, it is generally possible to use a thermoplastic resin having a higher toughness value than a thermosetting resin. , Strength, especially impact properties are improved. Furthermore, since the thermoplastic resin is cooled and solidified without a chemical reaction to determine the shape, it can be molded in a short time and has excellent productivity. Examples of such thermoplastic resins include polyamide (nylon 6, nylon 66, etc.), polyolefin (polyethylene, polypropylene, etc.), modified polyolefin, polyester (polyethylene terephthalate, polybutylene terephthalate, etc.), polycarbonate, polyamideimide, polyphenylene oxide, polysulfone. , Polyethersulfone, polyetheretherketone, polyetherimide, polystyrene, ABS, polyphenylene sulfide, liquid crystal polyester, a copolymer of acrylonitrile and styrene, and the like can be used. Moreover, you may use these mixtures. Further, it may be a copolymer of nylon 6 and nylon 66 such as copolymerized nylon. In addition, depending on the required characteristics of the molded product to be obtained, flame retardants, weather resistance improvers, other antioxidants, heat stabilizers, ultraviolet absorbers, plasticizers, lubricants, colorants, compatibilizers, conductive fillers, etc. Can also be added.

  In the prepreg included in the present invention, it is preferable that the prepregs are bonded to each other in terms of easy handling.

  The laminated base material used in the present invention is preferably laminated with a plurality of prepregs so that the directions of the reinforcing fibers are pseudo-isotropic from the viewpoint of reducing the flow anisotropy during pressing.

  One embodiment of a production method that can be used for a prepreg that can be used for the stampable molded article of the present invention will be described below, but the present invention is not particularly limited thereby.

  The prepreg that can be used in the stampable molded product of the present invention is prepared, for example, by preparing two sheets of thermoplastic resin in the form of a film, sandwiching a reinforcing fiber sheet in which reinforcing fibers are arranged in a sheet shape, and heating and It can be obtained by applying pressure. More specifically, two films are sent out from two rolls of a film made of thermoplastic resin, and a reinforcing fiber sheet supplied from a roll of reinforcing fiber sheets is placed between the two films. After sandwiching, heat and pressurize. As a means for heating and pressurizing, known means can be used, which requires a multi-step process such as using two or more heat rolls or using multiple pairs of preheating devices and heat rolls. It may be. Here, the thermoplastic resin constituting the film does not have to be one type, and a film made of another type of thermoplastic resin may be further laminated using the apparatus as described above.

  Although the said heating temperature is based also on the kind of thermoplastic resin, it is preferable that it is 100-400 degreeC normally. On the other hand, the pressure during pressurization is preferably 0.1 to 10 MPa. If it is this range, since it can be made to impregnate a thermoplastic resin between the reinforced fiber contained in a prepreg, it is preferable. Moreover, the prepreg which can be used for the laminated base material of this invention can also use the prepreg marketed.

  The prepreg included in the present invention can be obtained by making a cut using a laser marker, a cutting plotter, a cutting die, or the like. However, when a laser marker is used, a complicated cut such as a curve or a zigzag line can be made at high speed. It is preferable because it can be processed, and a cutting plotter is preferable because a large prepreg of 2 m or more can be processed. Furthermore, it is preferable that the cut is made by using a punching die because there is an effect that processing can be performed at high speed.

  In the next step, the prepreg obtained as described above is laminated in a desired configuration such that the direction of the reinforcing fibers is pseudo-isotropic to create a laminated base material. At this time, prepregs can be spot-welded with an ultrasonic welder because of easy handling. Moreover, it is preferable to laminate | stack the prepreg so that the lamination base material which can be used for the stampable molded article of this invention will be 8 to 96 layers.

  In the next step, a laminated base material obtained by integrating the laminated base material obtained as described above through a heating and pressurizing and cooling and pressing process is formed. This process can be performed using a normal apparatus, for example, a heating press machine, a cooling press machine, and a heating / cooling multistage press machine.

  About the heating in the said heating-pressing process, although depending also on the kind of thermoplastic resin contained in a laminated base material, it is preferable to heat at 100-400 degreeC, More preferably, it is preferable to heat at 150-350 degreeC. . Prior to the heating, preliminary heating may be performed.

  About the pressurization in the said heat pressurization process, as a heating pressure applied to a laminated base material or a pressure at the time of heat pressurization, Preferably it is 0.1-10 MPa, More preferably, it is 0.2-2 MPa. The pressure is a value obtained by dividing the pressing force by the area of the laminated base material.

  About the pressurization time in the said heating-pressing process, it is preferable that it is 0.1 to 30 minutes, More preferably, it is 0.5 to 15 minutes. Moreover, it is preferable that the cooling time provided after a heating and pressurization is 0.5 to 30 minutes.

  Furthermore, about the heating in the said cooling pressurization process, although depending also on the kind of thermoplastic resin contained in a laminated base material, it is preferable to heat at 30-200 degreeC, More preferably, it heats at 50-150 degreeC. Is preferred. Prior to the heating, preliminary heating may be performed.

  About the pressurization in the cooling and pressurizing step, the heating pressure applied to the laminated base material and the pressure at the time of heating and pressing are preferably 0.5 to 10 MPa, more preferably 0.8 to 2 MPa. The pressure is a value obtained by dividing the pressing force by the area of the laminated base material.

  About the pressurization time in the said cooling pressurization process, it is preferable that it is 0.1 to 30 minutes, More preferably, it is 0.5 to 15 minutes. The thickness of the laminated base material integrated through these steps is preferably 0.5 to 10 mm.

  In addition, you may perform the said heating-pressing process and a cooling pressurization process on the conditions where a lubricant exists between a type | mold and the said laminated base material. Due to the action of the lubricant, the fluidity of the reinforcing fibers contained in the prepreg constituting the laminated base material during the heating and pressurization is increased, so that the impregnation of the thermoplastic resin between the reinforcing fibers is increased and the obtained lamination is obtained. This is because voids between the reinforcing fibers and between the reinforcing fibers and the thermoplastic resin can be reduced in the substrate.

  As the lubricant, for example, a silicone-based lubricant or a fluorine-based lubricant can be used. Moreover, you may use these mixtures. As the silicone-based lubricant, a heat-resistant one that can be used in a high-temperature environment is preferably used. More specifically, silicone oils such as methylphenyl silicone oil and dimethyl silicone oil can be exemplified, and commercially available ones can be preferably used. As the fluorine-based lubricant, a heat-resistant one that can be used in a high temperature environment is preferably used. As specific examples of such a material, fluorine oil such as perfluoropolyether oil or a low polymer of ethylene trifluoride chloride (weight average molecular weight 500 to 1300) can be used.

  The lubricant is applied to the surface of one side or both sides of the laminated base material, the surface of one side or both sides of the mold, or the surface of one side or both sides of the laminated base material and the mold. It may be supplied by appropriate means, or may be previously applied on the surface of the mold. Among these, a mode in which the lubricant is supplied to the surfaces on both sides of the laminated base material is preferable.

  The manufacturing method of the stampable molded body of the present invention needs to be a stampable molded body through two steps of a preheating process and a stamping molding process.

  The preheating step of the method for producing a stampable molded body of the present invention can be performed by a conventionally known method. For example, a hot air drying method, a steam drying method, or an infrared heater method can be appropriately selected and used. Among them, an infrared heater method having high uniform irradiation and a high temperature rising effect is preferable. Further, depending on the thickness of the laminated base material, etc., one or more dryers may be appropriately combined. The preheating temperature at the time of preheating depends on the thermoplastic resin to be used, but the lower limit temperature needs to be heated to 150 ° C. or more, and preferably 180 or more. The upper limit temperature needs to be heated at 400 ° C. or lower, and preferably 350 ° C. or lower. By increasing the preheating temperature, it becomes possible to follow a more complicated shape at the time of stamping molding, but it may be decomposed depending on the type of thermoplastic resin used, so it is preferable to mold at an appropriate temperature range. . In addition, since there is a thermoplastic resin in which thermal decomposition is accelerated in the air and thermal decomposition is reduced by blocking the air, the laminated base material may be appropriately covered with a heat-resistant film or sheet.

  The stamping molding step of the stampable molded body manufacturing method of the present invention requires compression molding so that S1 / S2 is 0.85 to 0.95. When S1 / S2 is less than 0.85, the part where the reinforcing fibers occupying the front and back surfaces of the stampable molded body randomly flowed increases, and the switching position with the part maintaining the fiber orientation derived from the laminated base material is visible. It tends to come to a high part, which is not preferable. Furthermore, the part where the reinforcing fibers are randomly oriented tends to have larger surface irregularities than the part maintaining the fiber orientation derived from the laminated base material, which may be an obstacle when performing painting or the like. There is sex. On the other hand, when S1 / S2 exceeds 0.95, the number of randomly oriented reinforcing fibers tends to decrease, but there is a concern that the laminated base material bites into the end of the mold during charging. Many molds for forming into complicated shapes typified by ribs and bosses have a cut-off shape at the ends, and as a result of increasing the value of S1 / S2, the material is bitten and the mold is damaged. This is not preferable because there is a possibility. In addition, when the laminated base material is charged, it is difficult to charge the mold opening, and appearance defects may occur as a result of inducing wrinkles and sagging.

  The mold temperature during stamping molding depends on the thermoplastic resin used, but the lower limit temperature is preferably 40 ° C. or higher, more preferably 50 ° C. or higher. The upper limit temperature is preferably 300 ° C. or lower, more preferably 200 ° C. or lower. If the lower limit temperature of the mold temperature is too low, the laminated base material is rapidly cooled when charged, and there is a possibility that the ability to follow the complex shape of the ribs and bosses may be remarkably lacking. On the other hand, if the mold temperature is too high, the ribs and bosses have excellent conformability to complex shapes, but depending on the thermoplastic resin used, the crystallization time becomes too long and the molded appearance deteriorates and in some cases it has not been. There is a possibility of hardening.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited at all by these Examples. In the following examples and comparative examples, the following were used as raw materials.

(Production Example 1)
A carbon fiber sheet in which carbon fibers (manufactured by Mitsubishi Rayon Co., Ltd., product name: TR50S15L, 12,000, density 1.82 g / cm ² ) are arranged in a unidirectional plane so that the basis weight is 72.0 g / m ² did. A laminate was obtained by laminating a resin film having a basis weight of 36.4 g / m ² (product name: Modic (registered trademark) P958, manufactured by Mitsubishi Chemical Corporation) on both surfaces of the carbon fiber sheet. This laminate was passed through a calender roll heated to 200 to 260 ° C. multiple times to melt and impregnate the resin into a carbon fiber sheet to obtain a prepreg. The thickness of the obtained prepreg was 120 μm, the basis weight was 145.0 g / m ² , and the fiber deposition content (Vf) was 33.0%.

(Production Example 2)
The prepreg obtained in Production Example 1 was cut into 1240 mm × 940 mm, and cut using a cutting plotter (product name: L-2500, manufactured by Rezac) at regular intervals as shown in FIG. At that time, except for the inner portion of 10 mm from the end of the sheet, the length of the reinforcing fiber L = 25.0 mm is constant, and the notch and the reinforcing fiber are cut so that the average cutting length l = 42.4 mm. Cutting was performed at an angle θ = 45 °. At this time, the total length of cuts per 1 m ² was la = 56.6 m.

  After laminating so that the cut prepreg has 16 layers, the fiber axis direction is [0/45/90 / −45] s2, and the cut direction is [−45/0/45/90] s2, ultrasonic waves A laminate was obtained by partial welding with a welder (manufactured by Nippon Emerson, product name: 2000LPt).

  The obtained laminate was placed in a stamping mold with a depth of 1.5 mm, the heating panel was put into a multi-stage press machine preheated to 200 ° C., heated and pressurized at a pressure of 0.30 MPa for 10 minutes, The composite sheet 1 was obtained by cooling and pressurizing at a pressure of 1.0 MPa for 3 minutes. The obtained composite sheet 1 was free from fiber meandering, and the reinforcing fibers were evenly flowing to the end thereof, and was not warped and maintained good appearance and smoothness.

(Production Example 3)
The prepreg obtained in Production Example 1 was slit into a width of 15.0 mm, and then cut into a length of 25.0 mm using a guillotine type cutting machine to obtain a small piece prepreg.
3 kg of the obtained small piece prepreg is weighed and dropped one by one from a height of 30 cm so that the fiber orientation is random, and placed in a stamping mold with an inner size of 1240 mm x 940 mm and a depth of 20.0 mm After that, the heating panel is put into a multi-stage press machine preheated to 200 ° C., heated and pressurized at a pressure of 0.30 MPa for 10 minutes, and then cooled and pressurized at a pressure of 1.0 MPa for 3 minutes, and combined. Sheet 2 was obtained. In the obtained composite sheet 2, the reinforcing fibers flowed evenly to the end portions, and the uniform appearance and smoothness were maintained without warping.

(Production Example 4)
Using the dry cutting machine (manufactured by Tanaka Kikai Kogyo Co., Ltd., product name: Tanaka Flash Panel Saw) equipped with a chip saw, the composite sheet 1 obtained in Production Example 1 is used as the fiber axis direction of the outermost layer of the composite sheet. The length in the parallel direction (abbreviated as length) is cut to 500 mm, and the length in the direction orthogonal to the fiber axis direction (abbreviated as width) is cut to 455 mm, and polished paper (product name: Emery # 400, manufactured by Koyo) Then, the end face was polished to obtain an intermediate material 11. Similarly, it was cut into length 450 mm × width 450 mm, length 60 mm × width 15 mm, length 90 mm × width 15 mm to obtain an intermediate material 21, an intermediate material 12, and an intermediate material 13.

(Production Example 5)
Using the dry cutting machine, the obtained composite sheet 2 is 500 mm in length in a direction parallel to the fiber axis direction of the outermost layer of the composite sheet (length is abbreviated as length), and the length in the direction perpendicular to the fiber axis direction. The thickness (abbreviated as width) was cut to 455 mm, and the end face was polished with abrasive paper to obtain an intermediate material 22.

Example 1
After using a far-infrared heater type heating device (product name: H7GS-71289, manufactured by NGK Kiln Tech Co., Ltd.) adjusted so that the heater temperature is 280 ° C. and the internal temperature attached to the device is 200 ° C. to 230 ° C. The laminated intermediate material 11 was softened by heating for 6 minutes and 30 seconds. Furthermore, a mold having a projection area of 500 × 500 mm, comprising four ribs with a projection length of 70 mm and a depth of 15 mm along the bent portion on the back surface, and one boss with a diameter of 25 to 30 mm and a depth of 15 mm. Using the 500t press machine (Kawasaki Yoko Co., Ltd., product name: FMP2-500) used, the direction in which the four ribs are aligned is the width direction, and the direction perpendicular to the width direction is the depth direction. Then, charge along the undulation of the mold so that the fiber axis direction on the resurface of the intermediate material is parallel to the depth direction, and compression molding is performed with a charge time of 25 s, a mold temperature of 130 ° C., a molding pressure of 20 MPa, and a molding time of 3 minutes. A stampable molded body 11 was obtained. S1 / S2 was 0.91. The obtained stampable molded body 11 did not cause fiber meandering, and the ribs and bosses on the back surface were well introduced. In accordance with the evaluation described later, the appearance quality of the molded body was ◎, the rib introduction rate was ◯, and the boss introduction rate was ◎.

(Example 2)
Intermediate material 11, two intermediate materials 12, and a sheet made of Teflon (registered trademark) (manufactured by Nitto Denko Corporation, product name: NITOFLON No. UL900) are composed of three layers (intermediate material 12 / sheet / intermediate material 12) Two sets of the above laminates were softened by heating by the method described in Example 1. Subsequently, after the intermediate material 12 was directly charged to the four ribs of the mold, the intermediate material 11 was continuously charged, except that the compression molding was performed by the method described in Example 1, and the stampable molded body 12 was formed. Obtained. The value of S1 / S2 was 0.91. The obtained stampable molded body 12 did not cause fiber meandering, and the ribs and bosses on the back surface were well introduced. In accordance with the evaluation described later, the appearance quality of the stampable molded body was ◎, the rib introduction rate was ◎, and the boss introduction rate was ◎.

(Example 3)
A stampable molded body 13 was obtained in the same manner as in Example 2 except that the intermediate material 13 was used instead of the intermediate material 12. The value of S1 / S2 was 0.91. The obtained stampable molded body 13 did not cause fiber meandering, and the ribs and bosses on the back surface were well introduced. In accordance with the evaluation described later, the appearance quality of the molded body was ◎, the rib introduction rate was ◎, and the boss introduction rate was ◎.

(Comparative Examples 1-3)
The stampable molded bodies 21 to 23 were obtained in the same manner as in Examples 1 to 3 except that the intermediate material 21 was used instead of the intermediate material 11. Note that the values of S1 / S2 were both 0.81. The obtained stampable molded bodies 21 to 23 were good with no meandering of fibers, but partly caused meandering of the fibers, but the ribs and bosses on the back were well introduced. In accordance with the evaluation described later, the appearance quality of the stampable molded body 21 is ○, the rib introduction rate is ○, the boss introduction rate is ◎, the appearance quality of the molded bodies 22 to 23 is ○, the rib introduction rate is ◎, and the introduction of the boss The rate was ◎.

(Comparative Example 4)
A stampable molded body 24 was obtained in the same manner as in Example 1 except that the intermediate material 22 was used instead of the intermediate material 11. The value of S1 / S2 was 0.91. The obtained stampable molded body 24 was whitened due to decomposition of the resin in some places, but the ribs and bosses on the back surface were well introduced. In accordance with the evaluation described later, the appearance quality of the molded body 24 was Δ, the rib introduction rate was ◯, and the boss introduction rate was ◎.

(Appearance grade)
The appearance quality of the front and back surfaces of the obtained stampable molded body was evaluated by the operator as follows according to the sensitivity evaluation.
“◎”: Good appearance with no fluid / non-flowing part switching on the main surface of the molded body. “○”: Poor appearance with fluid / non-flowing switching part on the main surface of the molding. △ ”: Discoloration of resin and minute irregularities are scattered on the surface of the molded body“ × ”: Obvious irregularities, defects and fluff derived from fibers are scattered on the surface of the molded body

(Rib introduction rate)
The determination was made according to the rib introduction rate calculated from the following equation.
(Total of the volume of the rib part of the obtained molded body) / (Total of the volume of the rib part calculated from the mold shape) [%]
“◎”: 90% or more and 100% or less “◯”: 80% or more and less than 90% “Δ”: 70% or more and less than 80% “X”: less than 70%.

(Boss introduction rate)
The determination was made according to the boss introduction rate calculated from the following equation.
(Volume of boss part of the obtained molded body) / (Volume of boss part calculated from mold shape) [%]
“◎”: 90% to 100% “◯”: 80% to less than 90% “△”: 70% to less than 80% “X”: less than 70%

1 ... Cut 2 ... Reinforcement fiber 3 ... Cut length 4 ... Cut reinforcing fiber length 5 ... Stampable molded product

Claims (8)

  From a laminated base material formed by laminating a plurality of prepregs, each of which includes a reinforced fiber oriented in one direction and a thermoplastic resin, and has a notch of a depth that cuts the reinforced fiber in a direction crossing the reinforced fiber on the surface. A stampable molded product with a smooth front and back. A prepreg having a depth of notch that cuts the reinforcing fiber in a direction transverse to the reinforcing fiber on the surface of the prepreg including the reinforcing fiber oriented in one direction and the thermoplastic resin.
A step of laminating a plurality of sheets to form a laminated base material, and preheating the laminated base material at 150 to 400 ° C;
In the mold (mold projected area S2), a step of putting a laminated base material (laminated base material area S1);
The process of tightening the mold and filling the entire interior of the mold with molding material;
A method for manufacturing a stampable molded product, comprising a step of compression molding so that S1 / S2 is 0.85 to 0.95. The prepreg in which the cut is linear, the angle formed by the cut and the reinforcing fiber is 30 ° or more and 60 ° or less, and the total length of the cut per 1 m ^{2 of the} prepreg is 20 m or more and 150 m or less is used. The manufacturing method of the stampable molded article of description.   The method for producing a stampable molded article according to claim 2 or 3, wherein a prepreg in which the length of the reinforcing fiber cut by the cutting is 10 mm or more and 50 mm or less is used.   The manufacturing method of the stampable molded product according to any one of claims 2 to 4, wherein the reinforcing fibers are carbon fibers.   The stampable molded product according to any one of claims 2 to 5, wherein a plurality of prepregs constituting the laminated base material are laminated so that directions of reinforcing fibers contained in the prepreg are pseudo-isotropic. Manufacturing method.   The method for producing a stampable molded article according to any one of claims 2 to 6, wherein the volume content of the reinforcing fibers contained in the prepreg is 20 vol% or more and 55 vol% or less.   The method for producing a stampable molded article according to any one of claims 2 to 7, wherein a thickness of the prepreg is 50 µm or more and 200 µm or less.