JP2013176984A - Method of manufacturing molded product including rib structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a molded product of a fiber-reinforced composite material capable of achieving both formation of a face plate portion excellent in surface appearance, dimension accuracy and reliability and formation of a rib structure in press molding using sheet-shaped molding materials.SOLUTION: A preform includes: a sheet-shaped molding material (A) containing discontinuous reinforcement fiber and thermoplastic resin and having ≥1×10and ≤1×10of a density parameter p; and a sheet-shaped molding material (B) containing discontinuous reinforcement fiber and thermoplastic resin and having ≥1×10of a density parameter p which is 0.1 time as large as the density parameter of the molding material (A). By performing press molding of the preform by using an opening die having an opening for forming a rib structure and an opposing die opposing to the opening die, a molded product including the rib structure is manufactured. In a method for manufacturing the molded product, an area of the molding material (A) is set 70% or more of an projection area of the molded product, and the molding material (B) is disposed at an opening position of the opening.

Description

  The present invention relates to a method for producing a molded article having a rib structure by press molding using a molding material composed of reinforcing fibers and a thermoplastic resin.

  Fiber reinforced composite material (FRP), especially carbon fiber reinforced composite material (CFRP) using carbon fiber as the reinforced fiber, is super lightweight and excellent in specific strength and specific rigidity, including structural members for space and aircraft, sports equipment, automobiles It is widely used in industrial applications such as parts for motorcycles, parts for motorcycles, and parts for electrical and electronic equipment.

In recent years, the reduction of greenhouse gases on a global scale has become a major issue, and there is an increasing demand for environmentally friendly materials including the automobile industry. Structure made of FRP is effective for weight reduction of the vehicle body, especially CFRP and can achieve significant body weight reduction by replacing the metal member, in addition to the reduction of CO ² by improving fuel efficiency, such as an electric vehicle environmental impact It is drawing attention for the realization of a small next generation powertrain.

  Therefore, in order to further spread FRP, active technological development has been made on manufacturing methods that increase productivity and economy. Here, press molding is preferably used because it is suitable for mass production of a large number of molded products having a relatively complicated shape, but it is difficult to obtain a molded product with a complicated shape with higher quality and higher accuracy than before. Was an issue.

  For example, FRPs are known in which molding materials such as sheet molding compound (SMC) and glass mat thermoplastic (GMT) are manufactured in a short time by press molding. Since the resin and the fiber are molded while greatly flowing, there arises a problem that the characteristics greatly fluctuate along the flow, a problem that the characteristics are greatly decreased depending on a part, and a problem that the molded product is warped or twisted.

  On the other hand, in a press molding method for molding materials composed of reinforcing fibers and thermoplastic resins, by using homogeneous molding materials and arranging these molding materials in a larger area than the mold cavity, there is no significant flow. A technique for press molding has been proposed (Patent Document 1).

  According to this technique, the problem due to the large flow as described above does not occur, and the obtained molded product can obtain high strength and uniform characteristics, but a molded product having a narrow flow path and a high rib shape. In the case of manufacturing, it has been desired to develop a technique capable of sufficiently filling the rib portion with fibers.

  In addition, a technique has been proposed that achieves both fluidity and high strength by performing stamping molding using a base material in which the length of the reinforcing fiber is changed in the thickness direction (Patent Document 2). However, since the base material is manufactured integrally, it is difficult to control the fluidity. When the shape is complicated, the entire molding material is caused to flow, causing problems such as warping and twisting of the molded product. Above all, since the base material cannot be selectively arranged depending on the location such as the shape to be flowed and the shape not to be flowed, the problem of conventional press molding has not been solved in the end.

  Furthermore, a technology has been proposed in which a rib shape is press-molded by using a uniform molding material composed of reinforcing fibers and a thermoplastic resin, and using these differently-sized base materials for preforming (Patent Literature). 3). According to this method, it becomes easier to fill the substrate by selectively disposing the base material on the rib portion, but further technical development is required to form a finer and higher rib with high accuracy.

JP 2010-235777 A Japanese Patent Laid-Open No. 8-052735 JP 2009-196146 A

  The object of the present invention is to eliminate the problems of the prior art and to form a face plate portion with excellent surface appearance, dimensional accuracy, and reliability and rib structure formation in press molding using a sheet-like molding material. It is to obtain a molded product of compatible fiber reinforced composite material.

In order to solve the above problems, the present invention has the following configuration. That is, a sheet-like molding material containing discontinuous reinforcing fibers and a thermoplastic resin and having a concentration parameter p represented by the following general formula (1) of 1 × 10 ⁴ or more and 1 × 10 ⁸ or less ( A), a discontinuous reinforcing fiber and a thermoplastic resin, the concentration parameter p represented by the following general formula (1) is 1 × 10 ¹ or more, and the concentration parameter 0 of the molding material (A) is 0 A rib containing a preform containing a sheet-shaped molding material (B) that is less than 1 times is press-molded using an opening mold having an opening for forming a rib structure and an opposing mold facing the preform. In manufacturing a molded article having a structure, a rib structure in which the area of the molding material (A) is 70% or more of the projected area of the molded article, and the molding material (B) is disposed at the opening position of the opening. It is a manufacturing method of the molded article which has.

n: Number of flow units made of reinforcing fibers per unit area (1 mm ² ) of molding material h: Thickness of molding material (mm)
Ln: number average fiber length of reinforcing fibers (mm)

  According to the present invention, when laminating a sheet-like molding material containing discontinuous reinforcing fibers and a thermoplastic resin and press molding, the surface appearance and dimensional accuracy can be obtained by using two or more molding materials having different configurations. Thus, a molded product having a rib structure can be obtained in which the formation of a highly reliable face plate portion and the formation of a rib structure are compatible.

Perspective perspective view of a single-character rib molding die used in Examples and Comparative Examples Schematic diagram of reinforcing fiber dispersed with single yarn Schematic diagram of reinforcing fiber dispersed in fiber bundle Explanatory drawing of criteria for judging as a fiber bundle Explanatory drawing of the measuring method in the number of single fibers constituting the flow unit Illustration of projection surface of molded product Schematic diagram of an opening mold for explaining the projection plane of the opening Schematic diagram of opening die for explaining rib thickness of opening and height of rib structure Schematic representation of the dispersion state of reinforcing fibers in the molding material Simplified drawing of opening mold of single-character rib molding mold used in Examples and Comparative Examples Simplified view of the opposing mold of the mold for forming single-character ribs and cross ribs used in Examples and Comparative Examples Perspective perspective view of a mold for forming a cross rib used in Examples and Comparative Examples Simplified drawing of opening mold of cross rib forming mold used in Examples and Comparative Examples

  Hereinafter, preferred embodiments of the present invention will be described.

  In the present invention, a preform is press-molded using a pair of opposed molds to produce a molded product having a rib structure. One mold in the pair of molds has an opening for forming a rib structure, and is called an opening mold. The other mold in the pair of molds faces the opening mold and is referred to as an opposed mold. An example of such a pair of molds is shown in FIG. The pair of molds shown in FIG. 1 is attached to a press device (not shown), and is a pair of male and female molds having a concave portion and a convex portion. Further, as shown in FIG. 1, the concave mold 1 has an opening 3, which corresponds to the rib portion of the molded product, and further the volume of the hollow portion of the opening is defined as the cavity of the opening. Volume.

  In general, molds are roughly classified into two types, one is a sealed mold used for casting or injection molding, and the other is an open mold used for press molding or forging. The hermetically sealed mold is a mold mainly formed by pouring a material into the interior, and the open mold is a mold formed mainly by deforming without flowing the material. Without causing excessive flow to the base material during molding, disturbing the fiber orientation of the molding material or preform during molding, or suppressing the occurrence of anisotropy in the fiber orientation due to flow during molding, as much as possible, In order to obtain a molded article utilizing the fiber orientation of the molding material or preform, it is preferable to use an open mold. An open mold is also preferable from the viewpoint of eliminating decomposition gas and mixed air from the mold during molding.

  Further, the mold is preferably a mold having at least one selected from a punching mechanism, a punching mechanism, and a tapping mechanism. Molded products obtained by press molding may be molded by pressing with the charge rate of the molding material or preform larger than 100% of the total projected area of the cavity of the mold. May have necessary parts (ends). Therefore, in order to finish the shape of the molded product after molding, a step of removing this end portion may be necessary. Depending on the purpose of use of the molded product, the purpose is to provide gas and heat exchange vents and exhaust ports, gripping parts of molded products, screw holes for processing, holes for bolt connection, and design. It is assumed to be processed into a molded product having a hole portion used for the hole or punching pattern. By having at least one selected from the three mechanisms described above, the step of removing the end portion after press molding and the step of forming the necessary hole can be performed simultaneously with press molding, simplifying the process. This is preferable because it can be achieved.

  The type of press molding can be selected according to the obtained molded product. Here, press molding is a method of obtaining a molded body by applying deformation such as bending, shearing, compression, etc. to the laminated preform using a processing machine and a mold, a tool, etc. Examples include deep drawing, flange, call gate, edge curling, stamping and the like. As a press molding method, among various existing press molding methods, a die pressing method in which molding is performed using a metal mold is used from the viewpoint of flexibility in molding pressure and temperature.

  In the mold pressing method, a molding material or a preform is placed in a mold in advance, pressed and heated together with mold clamping, and then cooled while the mold is being clamped. In the case of a hot press method for obtaining a molded product by cooling, or when the resin of the base material is a thermoplastic resin, the molding material or preform is previously set to a temperature higher than the melting temperature of the thermoplastic resin, a far infrared heater, a heating plate, Heated with a heating device exemplified by a high-temperature oven, dielectric heating, etc., in a state where the thermoplastic resin has been melted and softened, placed on the mold that will be the lower surface of the mold, and then closed and clamped Stamping press molding, which is a method of performing and then pressurizing and cooling, can be employed. The press molding method is not particularly limited, but stamping press molding is preferable from the viewpoint of increasing the productivity by increasing the molding cycle.

  In the molded product, it is important that ribs are formed from the viewpoint of increasing rigidity and reducing warpage. In the present invention, a rib structure is formed by press-molding a sheet-like molding material to flow and fill the material into the opening of the opening mold that is out of plane. The rib structure can be formed by a single molding by a method in which the material is flowed to the opening of the opening mold by press molding. The shape of the rib is not particularly limited, but a single character rib, a cross rib, a lattice rib, and the like are preferable. Furthermore, it is preferable that a plurality of ribs are formed in the molded product from the viewpoint of increasing the rigidity of the molded product.

  In the present invention, the preform includes a sheet-like molding material containing discontinuous reinforcing fibers and a thermoplastic resin. A preform includes at least a molding material in which a reinforcing fiber is impregnated with a resin, and is formed by laminating or arranging the molding materials side by side, and is provided to the molding process directly or through a secondary processing process. The preform in the present invention includes a molding material (A) and a molding material (B) described later as molding materials. Here, “lamination” means a state in which at least a part of molding materials overlap each other, and “side-by-side” means an adjacent arrangement in which parts of the molding materials do not substantially overlap each other. Furthermore, in the present invention, two or more preforms may be combined and used for press molding. In addition, a preform form at the time of mold clamping is referred to as a final form preform. The secondary processing process is not particularly limited, but a cutting process for cutting the molding material into a predetermined size and shape, a bonding process for bonding the molding materials together to improve the handling of the preform, and air from the preform. An example is a defoaming step of removing. Next, a sheet-shaped molding material containing discontinuous reinforcing fibers and a thermoplastic resin used in the present invention will be described. The form of the molding material used in the present invention is a sheet, and the configuration of the molding material is not particularly limited as long as it is a thermoplastic resin composed of discontinuous reinforcing fibers and thermoplastic resin and reinforced with discontinuous reinforcing fibers. Not done. As the form of the reinforcing fiber, it is important that the reinforcing fiber is a discontinuous reinforcing fiber in consideration of the shaping property of the molding material or the preform. Here, the discontinuous reinforcing fiber referred to in the present invention refers to a reinforcing fiber obtained by including a step of substantially cutting the reinforcing fiber in the process of manufacturing an intermediate or a molding material made of the reinforcing fiber. As the form of the discontinuous reinforcing fibers, for example, the discontinuous reinforcing fibers are bundled and / or dispersed in a single fiber, and the reinforcing fibers are arranged in one direction, or the discontinuous reinforcing fibers are bundled. And / or a form in which reinforcing fibers are randomly oriented in a state of being dispersed in a single fiber. From the viewpoint that it is not necessary to strictly consider the direction of lamination, the reinforcing fiber arrangement included in the molding material is in a state of discontinuous reinforcing fiber bundles and / or dispersed in a single fiber. It is preferable that the fibers are randomly oriented.

  As a molding material used in the present invention, for example, a needle is pierced into a plurality of discontinuous strand-like reinforcing fibers, a thermoplastic resin is laminated on mat-like strand reinforcing fibers in which fibers are entangled with each other, and this is heated and pressurized. A molding material obtained by randomly discontinuous reinforcing fiber bundles, and a molding material obtained by heating and pressurizing a thermoplastic resin having a powder shape, a fiber shape, a film shape, and a nonwoven fabric shape, and a reinforcing fiber Molding material obtained by heating and pressurizing a molding material obtained by pressurizing a kneaded melted thermoplastic resin, only reinforcing fibers, or a dispersion of powdered and fiber-shaped thermoplastic resin in the air Materials, molding materials obtained by heating and pressurizing nonwoven materials obtained by making paper from suspensions in which dispersed fibers and fiber-shaped thermoplastic resins are dispersed and mixed in water The reinforcement obtained by papermaking by heating and pressing a thermoplastic resin in the form of powder, fiber, film, and nonwoven fabric to a nonwoven material obtained by papermaking from a suspension in which only fibers are dispersed in water. Examples of the molding material include a molding material obtained by bonding the thermoplastic resin to a fiber nonwoven material. Among these, a molding material obtained by adhering a thermoplastic resin to a nonwoven fabric material of reinforcing fibers is preferably used from the viewpoint of leaving a long fiber in the molding material and having high rigidity and isotropic properties. Further, as a method for dispersing short reinforcing fibers in a molding material, a molding material obtained by pressurizing a kneaded mixture of reinforcing fibers and a molten thermoplastic resin is preferably used from the viewpoint of economy.

  The reinforcing fiber used in the present invention is not particularly limited, and examples thereof include metal fibers such as aluminum, brass and stainless steel, carbon fibers such as polyacrylonitrile (PAN), rayon, lignin and pitch, and graphite. Examples thereof include fibers, insulating fibers such as glass, organic fibers such as aramid, PBO, polyphenylene sulfide, polyester, acrylic, nylon, and polyethylene, and inorganic fibers such as silicon carbide and silicon nitride. Moreover, the surface treatment may be given to these fibers. Examples of the surface treatment include a treatment with a coupling agent, a treatment with a sizing agent, and an adhesion treatment of an additive in addition to a treatment for depositing a metal as a conductor. Moreover, these reinforcing fibers may be used individually by 1 type, and may use 2 or more types together. Of these, PAN-based, pitch-based and rayon-based carbon fibers are preferably used from the viewpoints of high specific strength and specific rigidity and a light weight reduction effect. In addition, glass fibers can be preferably used from the viewpoint of improving the economical efficiency of the obtained molded product, and in particular, it is preferable to use carbon fibers and glass fibers in combination from the balance of mechanical properties and economy. Furthermore, aramid fibers can be preferably used from the viewpoint of improving the impact absorbability and formability of the obtained molded article, and it is particularly preferable to use carbon fibers and aramid fibers in combination from the balance of mechanical properties and impact absorbability. In addition, reinforcing fibers coated with a metal such as nickel, copper, or ytterbium can be used from the viewpoint of increasing the conductivity of the obtained molded product. Among these, PAN-based carbon fibers that are excellent in balance between mechanical properties such as strength and elastic modulus and price are more preferably used.

  Next, the thermoplastic resin used for the molding material of the present invention will be described. The type of resin is not particularly limited, and any of the thermoplastic resins exemplified below can be used. For example, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, liquid crystal polyester, etc. Fluorine such as polyester, polyolefin such as polyethylene, polypropylene, polybutylene, polyoxymethylene, polyamide, polyphenylene sulfide, polyketone, polyetherketone, polyetheretherketone, polyetherketoneketone, polyethernitrile, polytetrafluoroethylene Resins, crystalline resins such as liquid crystal polymers, styrene resins, polycarbonate, polymethyl methacrylate, polyvinyl chloride, polyphenylene ether, Amorphous resins such as lyimide, polyamideimide, polyetherimide, polysulfone, polyethersulfone, polyarylate, etc., phenolic resin, phenoxy resin, polystyrene, polyolefin, polyurethane, polyester, polyamide, Examples thereof include thermoplastic elastomers such as polybutadiene, polyisoprene, fluorine, and acrylonitrile, and thermoplastic resins selected from these copolymers and modified products. In particular, from the viewpoints of heat resistance, flame retardancy, and chemical resistance, PPS resins are used, and from the viewpoint of molded product appearance and dimensional stability, polycarbonate resins and styrenic resins are used for the strength and impact resistance of the molded products. From the viewpoint, polyamide resins are more preferably used, and from the viewpoint of lightness, polyolefins such as polyethylene and polypropylene and acid-modified products thereof are more preferably used.

  To the thermoplastic resins exemplified in the above group, an impact improver such as an elastomer or a rubber component, and other fillers and additives may be added as long as the object of the present invention is not impaired. Examples of these fillers and additives include inorganic fillers, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, and coloring prevention. Agents, heat stabilizers, release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, foam control agents, or coupling agents.

  Further, it is generally known that the exemplified molding material has different fluidity depending on the type, form, arrangement, blending ratio, etc. of the reinforcing fiber or thermoplastic resin. In order to form the ribs by press molding, it is preferable to use a molding material with high fluidity, and for the formation of the face plate, from the viewpoint of ensuring isotropy, the fluidity is to prevent the uniform molding material from flowing. It is preferable to use a low molding material. As described above, the molding material is selected in accordance with the portion that is desired to flow and the portion that is not desired to be flowed. Several examples are given below as criteria for determining the magnitude of the fluidity.

  First, there is a method of comparing the magnitude of fluidity from apparent viscosity of the molding material. A molding material having a higher apparent viscosity has poor fluidity. Examples of the method for measuring the apparent viscosity include a melt flow rate and a rheometer. Second, there is a method of comparing the magnitude of fluidity based on the degree of fiber interference. As the interference between the reinforcing fibers contained in the molten resin increases, the degree of freedom of the reinforcing fibers decreases by being constrained by other reinforcing fibers, so that the molding material having a higher degree of fiber interference becomes less fluid. . The third is a method of comparing the magnitude of fluidity from the elongation rate of the molding material. The elongation rate is obtained by press-molding a disk-shaped molding material heated to a melting point or higher and expressing the area ratio of the molding material before and after the press as a percentage. A molding material having a smaller elongation rate becomes less fluid.

  In the method for determining the fluidity of the molding material described above, the present invention compares the fluidity of the molding material using fiber interference and the elongation rate. First, the concentration parameter p, which is an index for determining the magnitude of fiber interference, will be described.

The concentration parameter p of the molding material used in the present invention is an index of the degree of fiber interference, and is a parameter determined by the blending amount of the reinforcing fiber, the fiber length, the fiber diameter, the number of single fibers constituting the flow unit, and the like. Can be expressed by the above-described formula (1). Here, n is the number of flow units composed of reinforcing fibers contained per unit area (1 mm ² ) of the molding material, h is the thickness (mm) of the molding material, and Ln is the number average fiber length (mm) of the reinforcing fibers. is there.

Furthermore, the number n of flow units composed of reinforcing fibers contained per unit area (1 mm ² ) of the molding material is derived by the following equation (2). Here, wf is the basis weight of the reinforcing fiber contained in the molding material (g / m ² ), d0 is the diameter of the single fiber (μm), Ln is the number average fiber length (mm) of the reinforcing fiber, and ρf is the density of the reinforcing fiber (G / cm ³ ), k is the average focusing number of flow units. Here, the flow unit will be described. The flow unit is an aggregate or a single body made of reinforcing fibers. For example, as shown in FIG. 2, in the case of reinforcing fibers dispersed with a single yarn, each single fiber becomes a flow unit, When the reinforcing fibers are present as fiber bundles as in the SMC shown in FIG. 3, each of the fiber bundles becomes a flow unit. Here, in the case of a fiber bundle, it demonstrates using FIG. 4 as a judgment standard considered as one flow unit. When the angle between the fiber bundle composed of a certain reinforcing fiber and the adjacent single fiber or fiber bundle is 5 ° or less and they are substantially adjacent to each other, it is one fiber bundle, that is, one fiber bundle It is regarded as a current unit, and in other cases, it is treated as a separate current unit.

  Each parameter used for deriving the concentration parameter will be described in detail below. Here, each parameter relating to the molding material used for derivation of the concentration parameter shown below is calculated on the assumption of the molding material before heating. This limitation is due to the heating of the molding material, for example, when the molding material to which the foaming agent is added expands and changes in volume, or when the thermoplastic resin melts by heating, Springback may occur due to elastic recovery, but these involve volume changes, so even if the mixing ratio of the real reinforcing fiber and the thermoplastic resin is the same before and after heating, the resulting concentration parameter is different. This is to eliminate it. For this reason, the molding material is substantially voidless, and the calculation is performed with the resin completely impregnated.

  First, the average focusing number k will be described. The average focusing number k is the number of single fibers constituting the flow unit. The average focusing number k is derived by observing the flow unit composed of reinforcing fibers, counting the single fibers one by one, and directly obtaining the number, or the single fiber diameter d0 (μm) shown in FIG. 5 in advance. After the measurement, a method for obtaining an approximate number of single fibers from the width and height of the flow unit can be exemplified. When the number of single fibers constituting the flow unit is large, a method of obtaining from the width and height of the flow unit can be preferably used. A scanning electron microscope (SEM) or an optical microscope can be used for observation of a flow unit made of reinforcing fibers. The observation of the diameter d0 of the single fiber is not particularly limited, but a scanning electron microscope (SEM) can be used. Moreover, when a single fiber is not a perfect circle, the average value of 10 points | pieces measured at random is employable. Here, a method of removing the resin component contained in the molding material and taking out only the reinforcing fibers will be described. A method of dissolving using a solvent that dissolves only the resin of the molding material (dissolution method), or if there is no solvent that dissolves the resin, burn out only the resin in a temperature range in which the reinforcing fiber does not lose weight by oxidation. A method of sorting (burn-off method) and the like can be exemplified. In the measurement, 100 flow units made of reinforcing fibers can be selected at random, the number of single fibers constituting the flow unit can be measured, and the average value can be set as the average focusing number k. In addition, the method of extracting reinforcing fibers from the molding material by a burning method or a melting method does not cause a special difference in the obtained results by appropriately selecting the conditions.

  Next, as a method for measuring the number average fiber length Ln of the reinforcing fibers contained in the molding material, for example, the resin component contained in the molding material is removed by a melting method or a burning method, and the remaining reinforcing fibers are removed. There is a method of measuring by microscopic observation after filtering. For the measurement, 400 reinforcing fibers are selected at random, the length is measured with an optical microscope up to the 1 μm unit, and the number average fiber length Ln is calculated by the following equation (3). In addition, the method of extracting reinforcing fibers from the molding material by a burning method or a melting method does not cause a special difference in the obtained results by appropriately selecting the conditions.

  Li: measured fiber length (i = 1, 2, 3,..., 400)

  The method for measuring the basis weight wf of the reinforcing fibers contained in the molding material is not particularly limited, but can be determined by removing the resin component contained in the molding material and measuring the weight of only the remaining reinforcing fibers. Examples of the method for removing the resin component contained in the molding material include a melting method and a burning method. The weight can be measured using an electronic scale or an electronic balance. The size of the molding material to be measured is preferably 100 mm × 100 mm square, the number of measurements is n = 3, and the average value can be used.

  The density ρf of the reinforcing fibers is not particularly limited, but can be determined by using an underwater substitution method, a pycnometer method, a floatation method, or the like. Only a resin component can be removed from a 10 mm × 10 mm square molding material by a melting method or a burning method, and the remaining reinforcing fibers can be used for measurement. The number of measurements is n = 3, and the average value can be used.

  The method for measuring the thickness h of the molding material is not particularly limited, but can be measured using a caliper, a micrometer, a laser displacement meter, or an existing measuring means such as measuring the thickness by photographing with a camera. As a method that can be measured easily and accurately, an average value of 10 points measured randomly at intervals of about 100 mm is used for the molding material left for 10 minutes in a 23 ° C. temperature atmosphere using a micrometer. The method of making this thickness is preferred. Moreover, it is preferable that the thickness of a molding material (A) is 0.1-1 mm from a viewpoint of the handleability of a preform. If the molding material is thinner than 0.1 mm, the number of layers increases to obtain a predetermined thickness, and the work at the time of preforming becomes complicated. On the other hand, a molding material thicker than 1 mm may be subject to restrictions on the laminated structure with respect to a predetermined thickness. More preferably, it is 0.2 mm-0.8 mm, More preferably, it is 0.4 mm-0.6 mm.

  Next, the expansion rate used in the present invention will be described. As a method for measuring the elongation rate, a molding material cut into a disk shape is placed on a mold having a pair of opposing concave and convex inner surfaces, and after heating the molding material to a softening temperature or a melting point + 35 ° C., 20 MPa Press molding. The elongation rate is defined as the percentage of the area ratio of the molding material before and after pressing as shown in the following formula (4). Further, the size of the disk to be cut out is 150 mm in diameter and 2.5 mm in thickness. The measurement is n = 3, and the average is the elongation rate. As a method for measuring the diameter of the disk-shaped molding material, the diameter can be measured arbitrarily at three locations, and the average value can be used.

In the present invention, a molding material having a concentration parameter p of 1 × 10 ⁴ or more and 1 × 10 ⁸ or less is used as the molding material (A), and the molding material mainly forms the face plate portion. Moreover, it is preferable that the fiber length is short to improve the surface appearance of the face plate portion, and it is preferable that the fiber length is long to increase the rigidity. From the balance of surface appearance and rigidity, the concentration parameter p of the molding material (A) is more preferably 1 × 10 ⁴ or more and 1 × 10 ⁶ or less. On the other hand, a molding material in which the concentration parameter p is 1 × 10 ¹ or more and is 0.1 times or less the concentration parameter of the molding material (A) is used as the molding material (B), and molding mainly for forming the rib portion Become a material. Further, since the surface appearance in the rib portion can be improved by shortening the fiber length, the concentration parameter p of the molding material (B) is preferably 1 × 10 ¹ or more and 1 × 10 ³ or less, and the rib portion Since the reinforcing effect in can be increased by increasing the fiber length, it is preferably 1 × 10 ² or more and 0.1 times or less the concentration parameter of the molding material (A).

  Since the molding material (A) used in the present invention is preferably non-flowing or low-flowing from the viewpoint of securing the isotropy of the face plate part, the elongation ratio R (%) of the molding material (A) is 100. % Or more and less than 350%. More preferably, they are 100% or more and less than 250%, More preferably, they are 100% or more and less than 150%. On the other hand, since it is preferable that the molding material (B) is easily filled into the rib portion, the elongation rate R (%) of the molding material (B) is preferably larger than the elongation rate R of the molding material (A). % Is more preferable, and it is more preferable that it is larger than 450%. Although there is no restriction | limiting in particular about the upper limit of the elongation rate R (%) of a molding material (B), 1000% or less considered as the upper limit of the elongation rate of the molding material containing a reinforcement fiber can be illustrated.

  Here, in the present invention, the area of the molding material (A) is 70% or more of the projected area of the molded product obtained by press molding, and the molding material (B) is disposed at the opening position of the opening in the opening mold. To do.

  As shown in FIG. 6, the projected area of the molded product refers to the area of the projected surface (shaded portion) of the molded product portion in the mold. By setting the area of the molding material (A) to 70% or more of the projected area of the molded product, molding can be performed while maintaining the fiber orientation of the molding material without causing excessive flow of the molding material during molding. From the viewpoint of securing the isotropic property of the molding material, the area of the molding material (A) is more preferably 80% or more of the projected area of the molded product, and more preferably 100% or more of the projected area of the molded product. preferable. The upper limit of the area of the molding material (A) is not particularly limited, but is preferably 150% or less of the projected area of the molded product from the viewpoint of effectively using the molding material and saving waste.

  For example, as shown in FIG. 7, the molding material is disposed substantially in the region of the projection surface of the opening with respect to the projection surface 11 of the opening. Or the molding material is arranged so as to cover the entire area of the projection surface of the opening, or the molding material is arranged so as to be included in a part of the area of the projection surface of the opening. From the viewpoint of promoting the filling of the opening, it is preferable that the molding material is disposed so as to cover the entire area of the projection surface of the opening.

  Regarding the arrangement of the molding material (A) and the molding material (B) in the preform used in the present invention, the molding material (A) and the molding material (B) are laminated or arranged side by side. It is preferable that the preform is formed by arranging the molding material (A) on the mold surface facing the mold having the opening. Moreover, since symmetrical lamination is more preferable from the viewpoint of reducing warpage of the molded product, the molding material (A) is further arranged on the mold surface side having the opening, and the molding material (B) is interposed between the molding materials (A). A preform formed by laminating is preferable.

  The area of the molding material (B) used in the present invention is preferably at least 0.5 times the projected area of the opening forming the rib portion so that the molding material (B) is sufficiently filled in the rib portion. As shown in FIG. 7, the projected area of the opening refers to the area of the projected surface (shaded portion) of the opening in the mold. If the area of the molding material (B) is smaller than this, the amount of fluid flowing to the flat portion is larger than filling the rib portion, and the rib portion may be insufficiently filled. More preferably, the area of the molding material (B) is preferably 1 or more times the projected area of the opening. When the projected area of the opening is small, the size of the molding material cut out accordingly is small and the handling becomes worse. Therefore, the area of the molding material (B) is more preferably 5 times or more industrially, More preferably, it is 10 times or more. Although there is no restriction | limiting in particular about the upper limit of the area of a molding material (B), there exists a possibility that the isotropy of a molding material (A) may be disturb | confused by the molding material (B) located in a faceplate part flowing. Of the molding material (B), the rib portion is substantially filled with the molding material (B) arranged in the region of the projection surface of the opening, and is therefore smaller than 50 times. Is more preferable, and more preferably less than 30 times.

  Further, the molding material (B) contained in the preform used in the present invention has a sufficient material in the opening by making the total volume Vb of the molding material (B) larger than the cavity volume Vr of the opening. It is preferable because it can be filled. More preferably, Vb is greater than 5 times Vr, and even more preferably, Vb is greater than 10 times Vr. Here, the cavity volume Vr of the opening is a volume of a region corresponding to the opening 3 (shaded portion in FIG. 1) shown in FIG. The total volume of the molding material (B) preferably takes into account the relationship between the projected area of the opening and the area of the molding material (B). For example, when the area of the molding material (B) arranged relative to the projected area of the opening is large, the rib material is substantially filled with the molding material (in the area of the projection surface of the opening) ( Since B) is almost all, it is more preferable that the volume of the molding material (B) arranged in the region of the projected area of the opening is larger than the cavity volume of the opening.

  As the form of the preform used in the present invention, it is more preferable to arrange the molding material (B) next to the molding material (B). By disposing the molding material (A) beside the molding material (B), the molding material (B) is suppressed from flowing in the plane direction, and has an effect of promoting filling into the rib portion, which is more preferable. Furthermore, by disposing the molding material (A) on the molding material (B), the pressurizing effect increases when the mold is clamped, and the effect of increasing the filling of the rib portion is more preferable.

  As a preform used in the present invention, in the molding material (A) disposed between the molding material (B) and the opening mold, the molding material (in the region of the projection surface of the opening in the opening mold) It is preferable that a penetration part such as a notch or a notch is provided in A) because the molding material (B) easily flows from the penetration part and has an effect of increasing the filling of the rib part. If the penetrating portion is provided on a portion other than the projection surface of the opening in the opening mold, the strength of the face plate portion may be impaired. Therefore, it is preferable to keep the penetrating portion within the region of the projection surface of the opening. Although there is no restriction | limiting in particular in the formation method of a penetration part, A cutter knife, a drill, a thread saw, etc. can be used preferably. Further, the shape of the penetrating portion is not particularly limited, but for example, one or more cuts of one character, or a rectangular or elliptical cutout can be made. Further, at least one penetrating portion may be provided or a combination thereof may be provided.

  The number average fiber length Lb of the molding material (B) used in the present invention increases the rib strength when the reinforcing fibers contained in the molding material (B) sufficiently flow into the opening of the opening mold. It is preferable that Lb is 2 times or less of Tr with respect to the rib thickness Tr of the opening shown in FIG. Since the filling into the opening can be increased as the fiber length of the reinforcing fiber becomes shorter, Lb is more preferably 4 times or less of Tr, and even more preferably Lb is 10 times or less of Tr. In addition, the molding material (B) preferably has a high flow rate, but when a reinforcing effect in the rib structure is desired, a certain length of fiber length is required, so the number average fiber length Lb of the molding material (B) is 0. It is preferably 1 mm or more and 2 mm or less, more preferably 0.1 mm or more and 1 mm or less.

  The number average fiber length La of the molding material (A) used in the present invention is preferably 2 mm or more in order to ensure the strength of the face plate portion. More preferably, it is 3 mm or more. The upper limit of the number average fiber length La of the molding material (A) is not particularly limited, but an excessively long fiber length may impair the shapeability of the face plate portion, and is preferably 20 mm or less, more preferably. Is 10 mm or less.

  The orientation of the reinforcing fibers in the present invention can be arranged by a two-dimensional orientation angle. In general, base materials made of reinforcing fibers often have a configuration in which reinforcing fibers are bundled. Therefore, it is difficult to ensure isotropy as a molding material, and resin impregnation into the bundle is sufficient. In addition, the strength of the molded product may be reduced. Even if the reinforcing fiber bundle is dispersed in the single yarn, the same result is obtained if the single yarns of the reinforcing fibers come in contact with each other in parallel. Furthermore, the fiber orientation in the thickness direction causes the expansion of the thickness of the molding material or a preform obtained by laminating the molding material, and the handling property and moldability may be significantly impaired.

  Here, as the two-dimensional orientation angle, a two-dimensional orientation angle formed by a single fiber that is a reinforcing fiber and a single fiber that intersects the single fiber will be described with reference to the drawings. FIG. 9 is a schematic view showing a dispersion state of reinforcing fibers when only reinforcing fibers as an example of the molding material of the present invention are observed from the surface direction. Focusing on the single fiber 4-1, the single fiber 4-1 intersects with the other single fibers 4-2 to 4-7. The term “intersection” as used herein means a state in which a single fiber focused on the observed two-dimensional plane is observed crossing another single fiber. Here, in the actual molding material, the single fibers 4-1 and the single fibers 4-2 to 4-7 are not necessarily in contact with each other. The two-dimensional orientation angle is defined as an angle 12 that is not less than 0 degrees and not more than 90 degrees among two angles formed by two intersecting single fibers.

  Although there is no restriction | limiting in particular in the method of measuring the average value of a two-dimensional orientation angle from a molding material specifically, For example, the method of observing the orientation of a reinforced fiber from the surface of a molding material can be illustrated. In this case, polishing the surface of the molding material to expose the fibers is preferable because the reinforcing fibers can be more easily observed. Moreover, the method of observing the orientation of a reinforced fiber using transmitted light for a molding material can be illustrated. In this case, it is preferable to slice the molding material thinly because it becomes easier to observe the reinforcing fibers. Furthermore, a method of photographing the orientation image of the reinforcing fiber by observing the molding material by X-ray CT transmission can be exemplified. In the case of reinforcing fibers with high X-ray permeability, it is easier to observe reinforcing fibers by mixing tracer fibers with reinforcing fibers or applying tracer chemicals to reinforcing fibers. preferable.

Moreover, when measurement is difficult by the above method, a method of observing the orientation of the reinforcing fibers after removing the resin so as not to destroy the structure of the reinforcing fibers can be exemplified. For example, it can be measured by wrapping the molding material with aluminum foil, burning off the resin component, and observing the substrate made of the resulting reinforcing fibers with an optical microscope or an electron microscope. The average value of the two-dimensional orientation angle of the present invention is measured by the following procedures i and ii.
i. Two-dimensional with all single fibers (single fibers 4-2 to 4-7 in FIG. 1) intersecting with a single yarn (single fiber 4-1 in FIG. 9) which is a reinforcing fiber selected at random. The average value of the orientation angle is measured. For example, when there are a large number of other single fibers that cross a certain single fiber, an average value obtained by randomly selecting and measuring 20 other single fibers that intersect may be used instead.
ii. The measurement of i is repeated 5 times in total focusing on another single fiber, and the average value is calculated as the average value of the two-dimensional orientation angle. The average value of the two-dimensional orientation angle of the reinforcing fiber in the present invention is preferably 10 to 80 degrees. More preferably, it is 20 to 70 degrees, more preferably 30 to 60 degrees, and it is more preferable as it approaches 45 degrees which is an ideal angle. When the average value of the two-dimensional orientation angle is less than 10 degrees or greater than 80 degrees, it means that many reinforcing fibers are present in a bundle, and not only the mechanical properties are deteriorated but also two-dimensional etc. In some cases, the directivity is impaired, or the reinforcing fibers in the thickness direction cannot be ignored, and the economic burden in the laminating process increases.

  The tensile strength of the molding material is obtained by cutting a test piece from the molding material and measuring the tensile properties according to JIS K-7073 (1988). The test piece is measured in four directions of +45 degrees, −45 degrees, and 90 degrees with an arbitrary direction set to 0 degrees. The number of measurements in each direction was n = 5 or more, and the average value was the tensile strength. Of the tensile strengths measured in all four directions, the maximum value was σMax, the minimum value was σMin, and the ratio was the tensile strength ratio (σcMax / σcMin). The relationship between the maximum tensile strength σMax and the minimum tensile strength σMin of the molding material (A) is preferably not more than twice as large as σMin from the viewpoint of ensuring isotropy of the face plate portion. More preferably, σMax is 1.5 times or less of σMin, more preferably σMax is 1.3 times or less of σMin, and σMax is 1.1 times or less of σMin. It is extremely preferable because it can be considered.

  As a component of the molding material (B) used in the present invention, an end material obtained in the process of manufacturing or processing the molding material (A) may be included. When a recycled material is used for the molding material (B), it is preferable to include the molding material (A) having a relatively long fiber length from the viewpoint of enhancing the reinforcing effect of the rib portion. The method for producing the recycled material is not particularly limited, but as a simple method, a method of kneading using a kneader can be used.

  As the press molding in the present invention, it is preferable to employ stamping press molding. Next, the stamping press molding will be described in detail. Stamping press molding includes the following steps (I) to (IV).

  Step (I) is a step of heating the preform to a temperature equal to or higher than the softening temperature or melting point of the thermoplastic resin contained in the preform. Since it is necessary to heat the laminated or side-by-side arranged molding material to a temperature above which it can be molded, a heating device exemplified by a far-infrared heater, a heating plate, a high-temperature oven, dielectric heating and the like can be used. Among these, a far infrared heater can be preferably used because of easy control of the heating state. In addition, the form of the preform at the time of heating is a preform made of only the molding material (A) or the molding material (B), or a preform made of the molding materials (A) and (B), and the final form. Any of the preforms may be used.

  Step (II) is a step in which the preform heated in step (I) is transported and placed in a mold. That is, in the step (II), the molding material heated to the softening temperature or melting point of the thermoplastic resin or higher is transported and placed in an open molding die. The heated molding material is transported by a hand, a robot, etc., and placed in an open molding die from the viewpoint of safety in terms of work and placement accuracy of the molding material on a molding die in which press molding is performed.

  Step (III) is a step of pressurizing and cooling the preform by clamping a mold having a temperature lower by 20 ° C. to 150 ° C. than the softening temperature or melting point of the thermoplastic resin. That is, in step (III), the molding material having a temperature higher than the softening temperature or the melting point is pressurized and cooled by clamping the mold. The temperature of the molding die is such that the molding material is easily shaped and the surface of the molded body is within a temperature range of 20 ° C. to 150 ° C. lower than the softening temperature or melting point of the thermoplastic resin contained in the molding material. It is preferable from the viewpoint of appearance.

  Step (IV) is a step of opening the mold after cooling and taking out the molded product from the mold. After forming the shape by cooling to the softening temperature or melting point of the thermoplastic resin contained in the molding material by pressure cooling in the previous step (III), the mold is opened and the molded product is removed from the mold. Take it out.

  In the mold clamping in the step (III), when the preform comes into contact with the mold approaching the preform, the surface temperature of the preform on the approaching mold side is the softening temperature or melting point of the thermoplastic resin. It is preferably higher by 20 ° C or more. Generally, a heated preform has a surface temperature lower than the center temperature of the preform. Therefore, by keeping the surface temperature at least 20 ° C. above the softening temperature or melting point of the thermoplastic resin, It can be considered that the temperature is moldable, which is preferable. Since the surface temperature of the preform is cooled by the outside air during transportation to the mold after the heating is completed, by reducing the time from the end of heating to the mold clamping as much as possible, the softening temperature or melting point of the thermoplastic resin Since heating and cooling can be performed in a state of 20 ° C. or higher, it is extremely preferable for enhancing the surface appearance.

In the step (III), it is preferable that the pressure applied to the projection surface of the molded product is in the range of 10 to 40 MPa from the viewpoint of easy shaping of the molding material and easy control of the thickness of the molded product. In particular, the range of 15 to 30 MPa is preferable from the viewpoint of the equipment cost of the press molding machine, and more preferably 15 to 20 MPa.
In step (I), at least the molding material (A) and / or (B) constituting the preform is divided in a thickness range of 0.1 to 10 mm, and heated separately to soften the thermoplastic resin. Or it is preferable to make it more than melting | fusing point. If the molding material or preform is thick, or if the molding material expands by heating or springs back in the thickness direction, the heating efficiency is reduced. It is preferable because the heating time can be shortened by reducing the thickness of the body. More preferably, the thickness of the divided molding material or preform is 0.1 to 5 mm, and further preferably 0.1 to 2 mm. The divided molding material or preform can be formed into a final form preform by the step of placing it in a mold.

  It is preferable to include a step of forming a final form preform between the steps (I) and (II). Since the preform taken out from the heating device gradually cools with time, it is possible to press-mold at a higher temperature when the preform is transported than when the preform is produced on the mold. This is preferable because it is possible. Furthermore, it is more preferable to perform the final form in the furnace because the preform can be conveyed while maintaining a sufficiently high temperature.

  In the molded product obtained in the present invention, it is preferable that the height Hr (mm) of the rib structure satisfies the relationship of Hr ≧ 3 × H0 with respect to the face plate thickness H0 (mm) accompanied by the rib. Here, FIG. 8 shows the height Hr of the rib structure. The method for measuring the thickness H0 of the face plate portion of the molded product is not particularly limited, but in the same manner as the method for measuring the thickness h0 of the molding material, a caliper, a micrometer, a laser displacement meter, the thickness is measured with a camera, etc. Can be measured using existing measuring means. As a method that can be measured easily and accurately, an average value of 10 points randomly measured at intervals of about 100 mm with respect to a face plate portion of a molded product left for 10 minutes in a temperature atmosphere of 23 ° C. using a micrometer. Is preferable to make the thickness of the face plate part. As the height of the rib structure is as high as possible, the reinforcing effect of the face plate portion can be enhanced. Therefore, it is preferable that the relationship of Hr ≧ 3 × H0 is satisfied. Further, the upper limit of the height of the rib structure is not particularly limited. For example, when the rib structure is formed by material flowing from the face plate portion to the surface by press molding, the rib portion is thin when the face plate portion is thin. Since there is a limit to the amount of material that can flow, Hr is usually 50 times or less of H0. Moreover, since it is difficult to mold a rib structure that is too high, the formability and the reinforcing effect of the face plate portion can be satisfied by providing several rib structures having a short height.

Hereinafter, although the Example demonstrates the preform of this invention and the press molding method using the preform concretely, the following Example does not restrict | limit this invention.
The measurement methods used in the examples are described below.

(1) Measurement of adhesion amount of sizing agent As a sample, about 5 g of a carbon fiber bundle to which the sizing agent was adhered was collected and put into a heat-resistant container. Next, this container was dried at 120 ° C. for 3 hours. After cooling to room temperature in a desiccator, the weighed mass was designated as w1 (g). Subsequently, the whole container was heated in a nitrogen atmosphere at 450 ° C. for 15 minutes, and similarly cooled to room temperature in a desiccator, and the weighed mass was defined as w2 (g). Through the above treatment, the amount of carbon fiber sizing agent deposited was determined using the following equation (5). In addition, the measurement was performed 3 times and the average value was employ | adopted as adhesion amount.

(2) Reinforcement fiber density Measured by submerged substitution method. The density of the reinforcing fiber is ρf.

(3) Concentration parameter p of molding material
The height h (mm) of each molding material is measured with a micrometer. The molding material left for 10 minutes in a 23 ° C. temperature atmosphere was measured randomly at intervals of about 100 mm, and the average value of the 10 points was adopted.

The basis weight and fiber weight fraction of each molding material are measured. A 100 mm × 100 mm square plate was cut out from the molding material, and its weight w0 (g) was measured. Next, the cut molding material was heated in air at 500 ° C. for 1 hour, and the weight w1 (g) of the reinforcing fiber remaining after burning the resin component was measured. Here, the basis weight (g / m ² ) of the reinforcing fiber contained in the molding material was derived from the weight w1 (g) of the reinforcing fiber. Moreover, the fiber weight fraction (wt%) was calculated | required using the following Formula (6). All measurements were performed at n = 3, and the average value was used.

  In order to calculate the flow unit number n of reinforcing fibers contained in each molding material, the average focusing number k of reinforcing fibers is measured by the following method. Here, the diameter d0 (μm) of the single yarn is measured in advance with a scanning electron microscope (SEM). Moreover, when it was not a perfect circle, the average value of 10 points | pieces measured at random was employ | adopted.

  First, a 100 mm × 100 mm square plate is cut out from the molding material, the square plate is heated in air at 500 ° C. for 1 hour, the resin component is burned off, and the remaining reinforcing fiber is observed with an optical microscope. The average focusing number k of the flow unit is calculated. If the width and height of the flow unit is approximately d0, it is a single yarn and the convergence number k is 1. From the representative width and representative height of the flow unit, an approximate multiple of d0 is derived to determine the convergence number k of the flow unit. 100 flow units made of reinforcing fibers were selected at random, and the average value measured by the operation was adopted.

  The number average fiber length Ln of the reinforcing fibers contained in each molding material is measured. A part of the molding material was cut out, heated in air at 500 ° C. for 30 minutes in an electric furnace to sufficiently incinerate and remove the resin to separate reinforcing fibers, and 400 or more pieces were randomly extracted from the separated reinforcing fibers. The fiber lengths of these extracted reinforcing fibers are measured using an optical microscope, the lengths of 400 fibers are measured to the 1 μm unit, and the number average fiber length Ln is calculated using the above-described formula (3). Calculated.

Using the above measured values, the number n of flow units made of reinforcing fibers contained per unit area (1 mm ² ) of the molding material is derived from the above-described equation (2).

  Further, the concentration parameter p of the molding material is derived from the above-described equation (1).

(4) Elongation rate of molding material The elongation rate of the molding material is measured. First, a disk having a diameter of 150 mm was cut out from the molding material. A disc-shaped molding material whose thickness was adjusted to 2.0 mm was used as a measurement sample, placed in an oven equipped with a far infrared heater, and preheated for 10 minutes. At this time, using a multi-input data collection system (manufactured by Keyence Corporation, NR-600), a thermocouple was installed on the surface of the sample and in the center of the disk, and the thermal history was measured. After confirming that the measured temperature was the melting point of the resin alone + 35 ° C., the sample taken out of the oven was placed on the lower mold, the upper mold was lowered, and press molding was performed at a surface pressure of 20 MPa. After pressurizing and cooling in this state for 1 minute, the upper mold was raised to obtain a molded product. The obtained molded product had a substantially circular disk shape.

  The diameter of the molded product was measured at two arbitrary locations, and the area of the molded product after molding was derived using the average value. The area of the molding material before molding was calculated with a diameter of 150 mm. Here, the elongation ratio of the molding material was defined and obtained by the above-described formula (4).

(5) Tensile strength ratio of molding material (σcMax / σcMin)
As a test piece for measurement, a tensile test piece having a length of 250 mm ± 1 mm and a width of 25 ± 0.2 mm is cut out from the molding material. Test specimens were prepared by cutting out test specimens in four directions of + 45 °, −45 °, and 90 ° when an arbitrary direction was set to 0 °, and the number of measurements in each direction was n = 5, and the average The value was taken as the tensile strength. Of the tensile strengths measured in all four directions of 0 °, + 45 °, −45 °, and 90 ° in the molded article to be measured, the maximum value is σcMax, the minimum value is σcMin, and the ratio is the tensile strength ratio (σcMax). / ΣcMin). According to the test method specified in JIS K-7073 (1988), the tensile strength was measured at a standard head distance of 150 mm and a crosshead speed of 2.0 mm / min. As the measuring device, “Instron (registered trademark)” 5565 type universal material testing machine (manufactured by Instron Japan Co., Ltd.) was used.

(6) Two-dimensional orientation angle of reinforcing fiber in molding material The molding material cut into 5 cm square was wrapped in aluminum foil, and this was heated in air at 500 ° C. for 1 hour to burn off the resin component. The aluminum foil wrapped with the molding material was opened and placed on the microscope stage. The obtained substrate made of reinforcing fibers was observed with a microscope, one single filament was selected at random, and the two-dimensional orientation angle with another single fiber intersecting with the single fiber was measured by image observation. Of the two angles formed by the two intersecting single fibers, the angle between 0 ° and 90 ° (acute angle side) was adopted as the orientation angle. The number of measured two-dimensional orientation angles per selected single fiber was n = 20. The same measurement was performed by selecting a total of 5 single fibers, and the average value was taken as the two-dimensional orientation angle.

(7) Surface appearance of molded product face plate The face plate surface was visually observed and evaluated according to the following criteria. A and B are acceptable and C is unacceptable.
A: The face plate has no faint marks or holes, and has an excellent surface appearance.
B: Although there is no practical problem, a faint mark is seen on a part of the face plate.
C: The face plate is unfilled or perforated, and the entire surface is faint and inferior.

(8) Warpage of molded product face plate The rib side of the molded product was the upper surface, the face plate surface was grounded to a flat base, and the maximum height from the ground contact surface to the face plate surface was measured. Since the warpage of the molded product face plate is preferably small, the measured maximum height was determined to be less than 10 mm.

(9) Appearance quality of molded product rib part The rib part was visually observed and evaluated according to the following criteria. From the viewpoint that it is preferable that the rib is completely filled with the material, AA, A, and B were set as acceptable.
AA: Completely filled, no resin rich part, and no trace of blur A: Completely filled, no resin rich part, and partially blurred trace B: Resin rich part is present, but completely filled C: 80% or more Filling amount less than 100% D: Filling amount less than 80%

(10) In-plane average bending strength of molded product and in-plane variation of bending strength A test piece for measurement was cut out from the molded product, and the bending strength was measured according to ISO 178 method (1993). The cut-out part was a face plate part as close to the center as possible, avoiding the end of the molded product, and a face plate part without ribs was used. Test specimens were prepared by cutting out test specimens in four directions of + 45 °, −45 °, and 90 ° when any direction was set to 0 ° in each surface portion, and the number of measurements in each direction was n = 5. And the average value was taken as the bending strength. As the measuring apparatus, “Instron (registered trademark)” 5565 type universal material testing machine (manufactured by Instron Japan Co., Ltd.) was used.

  The average value of individual bending strengths of 0 °, + 45 °, −45 °, and 90 ° in the face plate portion to be measured was defined as the in-plane average bending strength. Since it is preferable that the face plate portion has high strength, the in-plane average bending strength is determined to be 150 MPa or more.

  Using the following equation (7), the individual bending strengths of 0 °, + 45 °, −45 °, 90 ° in the face plate portion to be measured and the average value of the bending strength measured in all four directions are used. did. Since the face plate portion preferably has isotropic properties, the in-plane variation of the bending strength of the molded product was accepted as less than 12%.

(11) Fiber filling rate and porosity of molded product rib part Using the sample cut out from the rib part of the molded product, the specific gravity ρr1 (g / cm ³ ) was measured according to ISO 1183 (1987). The number of measurement samples was n = 3. The cut-out position was cut into a size of width 10 mm × length 50 mm with reference to the inside 5 mm from the rib root. Here, let the average value of the weight of the sample measured in the air be weight w6 (g).

Furthermore, the sample cut out above is heated in air at 500 ° C. for 1 hour, and the weight w7 (g) of the reinforcing fiber left after burning the resin component is measured. For each measurement, n = 3, and the average values derived using the following formulas (8), (9), and (10) are used as the fiber weight fraction Wfr (%) and the fiber volume fraction Vfr (%) of the rib part. And density ρr2 (g / cm ³ ). It is assumed that the density ρF of the reinforcing fiber and the density ρR of the resin.

  Next, the fiber filling rate of the rib portion was derived. In the case of one type of molding material, the ratio of the fiber weight fraction Wfr of the rib portion to the fiber weight fraction Wf (%) of the molding material was defined as the fiber filling rate of the rib portion. Further, when two or more kinds of molding materials were used, the ratio of the fiber weight fraction Wfr of the rib portion to the fiber weight fraction Wf (%) of the molding material having the smallest concentration parameter was defined as the fiber filling rate of the rib portion. The fiber filling rate of the rib part was set to 0.7 or more, which is considered to be sufficient from the viewpoint of increasing the rib strength and increasing the reinforcing effect of the top plate as the fiber filling rate increases. In addition, it was determined that measurement was not possible if the amount of filling in the rib portion was small and the sample could not be cut out.

  Moreover, the porosity of the rib part was calculated | required using the following Formula (11). From the viewpoint that the rib is a reinforcing member for the top plate, the allowable void ratio of the rib portion is considered to be less than 8%, and it was set as an acceptable line.

(12) Method for measuring temperature of molding material during preheating The temperature of the molding material during preheating is measured using a multi-input data collection system (manufactured by Keyence Corporation, NR-600). When measuring the temperature of the laminated odd (2n-1) molding materials, a thermocouple is attached to the surface and end of the molding material located in the middle (nth sheet). When the number of stacked layers is an even number (2n), a thermocouple is attached to the surface and end of the nth sheet located between the nth sheet and the (n + 1) th sheet. However, when molding materials having different sizes are used, only the molding material having the largest area is targeted, and the number of layers is counted to install a thermocouple. In the case of preheating a single molding material, a thermocouple is attached to the surface and end of the molding material, and measurement is performed.

(13) Method for measuring surface temperature of molding material during mold clamping Using a multi-input data collection system (NR-600, manufactured by Keyence Corporation), the mold approaching the molding material and the molding material come into contact with each other. At the time, the surface temperature of the molding material is measured. The attachment location of the thermocouple is the surface and end located on the mold side of the nearest molding material with respect to the approaching mold.

(Reference Example 1) Preparation of carbon fiber Spinning and firing were performed from a polymer mainly composed of polyacrylonitrile to obtain a continuous bundle of carbon fibers having a total filament number of 12,000. A sizing agent was applied to the carbon fiber continuous bundle by an immersion method and dried in heated air at a temperature of 120 ° C. to obtain a PAN-based carbon fiber bundle. The characteristics of this PAN-based carbon fiber bundle were as follows.

Single fiber diameter: 7 μm
Mass per unit length: 0.83 g / m
Specific gravity: 1.8 g / cm ³
Tensile strength: 4.0 GPa
Tensile modulus: 235 GPa
Sizing type: Polyoxyethylene oleyl ether Sizing adhesion amount: 2% by mass
(Reference Example 2) Chopped carbon fiber bundle 1
Using a cartridge cutter, the carbon fiber of Reference Example 1 was cut to obtain a chopped carbon fiber bundle having a fiber length of 9 mm.

Reference Example 3 Chopped carbon fiber bundle 2
In the same manner as in Reference Example 2, a chopped carbon fiber bundle 2 having a fiber length of 6 mm was obtained.

(Reference Example 4) Chopped carbon fiber bundle 3
In the same manner as in Reference Example 2, a chopped carbon fiber bundle 3 having a fiber length of 100 mm was obtained.

(Reference Example 5) Chopped carbon fiber bundle 4
In the same manner as in Reference Example 2, a chopped carbon fiber bundle 4 having a fiber length of 3 mm was obtained.

(Reference Example 6) Chopped glass fiber bundle, manufactured by Nittobo, trade name CS13G-874
Single fiber diameter: 10 μm
Specific gravity: 2.5 g / cm ³
Fiber length: 13mm (catalog value)

Reference Example 7 Unmodified Polypropylene Resin Prime Polymer Co., Ltd. “Prime Polypro” (registered trademark) J105G, melting point 160 ° C.

(Reference Example 8) Acid-modified polypropylene resin “Admer” (registered trademark) QE510, melting point 160 ° C., manufactured by Mitsui Chemicals, Inc.

(Reference Example 9) Nylon 6 resin “Amilan” (registered trademark) CM1001, manufactured by Toray Industries, Inc., melting point 225 ° C.

(Reference Example 10) Preparation of carbon fiber mat 1 100 liters of a 1.5 wt% aqueous solution of a surfactant (manufactured by Wako Pure Chemical Industries, Ltd., “sodium n-dodecylbenzenesulfonate” (product name)) was stirred. A pre-foamed dispersion was prepared. To this dispersion, the chopped carbon fiber bundle 1 obtained in Reference Example 2 was added, stirred for 10 minutes, then poured into a paper machine having a paper surface of 500 mm length × 500 mm width, dehydrated by suction, and 150 ° C. The carbon fiber mat 1 made of carbon fibers was obtained by drying at a temperature of 2 hours.

Reference Example 11 Preparation of Carbon Fiber Mat 2 In the same manner as in Reference Example 10, using the chopped carbon fiber bundle 2 obtained in Reference Example 3, a carbon fiber mat 2 made of carbon fibers was obtained.

Reference Example 12 Preparation of Carbon Fiber Mat 3 In the same manner as in Reference Example 10, the chopped carbon fiber bundle 3 obtained in Reference Example 4 was used to obtain a carbon fiber mat 3 made of carbon fibers.

Reference Example 13 Adjustment of Glass Fiber Mat In the same manner as in Reference Example 10, a chopped glass fiber of Reference Example 6 was used to obtain a glass fiber mat made of glass fiber.

Reference Example 14 Preparation of Polypropylene Resin Film 90% by mass of the unmodified polypropylene resin of Reference Example 7 and 10% by mass of the acid-modified polypropylene resin of Reference Example 8 were prepared and dry blended. This dry blend product was put in from a hopper of a twin screw extruder, melt kneaded in the extruder, and then extruded from a T-die (500 mm width). Then, it cooled and solidified by taking up with a 60 degreeC chill roll, and obtained the polypropylene resin film.

Reference Example 15 Preparation of Nylon 6 Resin Film Nylon 6 resin of Reference Example 9 was melt-kneaded in the same manner as in Reference Example 14 to obtain a nylon 6 resin film.

Reference Example 16 Preparation of Molding Material 1 The carbon fiber mat 1 obtained in Reference Example 10 and the polypropylene resin film obtained in Reference Example 14 were alternately laminated to prepare a laminate. A laminate sandwiched between release sheets was placed on a metal tool plate, and a tool plate was further disposed thereon. A Teflon (registered trademark) sheet (thickness 1 mm) was used as a release sheet. Next, the laminate was placed between the hot platen surfaces of a hydraulic press machine composed of upper and lower hot platen surfaces heated to 210 ° C. and pressed at a surface pressure of 5 MPa. Next, it is transported to another hydraulic press controlled at a temperature of 80 ° C., placed between cooling boards, and then subjected to a cooling press at a surface pressure of 5 MPa, and a length of 500 mm made of carbon fiber mat and polypropylene resin, A molding material 1 having a width of 500 mm, a thickness of 0.5 mm, and a fiber weight fraction of 33.3 wt% was obtained. Other material properties are shown in Table 1.

Reference Example 17 Preparation of Molding Material 2 In the same manner as in Reference Example 16, the carbon fiber mat 2 obtained in Reference Example 11 and the polypropylene resin film obtained in Reference Example 14 were used. Length 500 mm, width 500 mm A molding material 2 having a thickness of 2.0 mm and a fiber weight fraction of 14.8 wt% was obtained. Other material properties are shown in Table 1.

Reference Example 18 Preparation of Molding Material 3 In the same manner as in Reference Example 16, the carbon fiber mat 1 obtained in Reference Example 10 and the polypropylene resin film obtained in Reference Example 14 were used. Length 500 mm, width 500 mm A molding material 3 having a thickness of 0.5 mm and a fiber weight fraction of 18.2 wt% was obtained. Other material properties are shown in Table 1.

Reference Example 19 Preparation of Molding Material 4 In the same manner as in Reference Example 16, the carbon fiber mat 1 obtained in Reference Example 10 and the polypropylene resin film obtained in Reference Example 14 were used. Length 500 mm, width 500 mm A molding material 4 having a thickness of 0.5 mm and a fiber weight fraction of 57.1 wt% was obtained. Other material properties are shown in Table 1.

Reference Example 20 Preparation of Molding Material 5 In the same manner as in Reference Example 16, the carbon fiber mat 3 obtained in Reference Example 12 and the polypropylene resin film obtained in Reference Example 14 were used. Length 500 mm, width 500 mm A molding material 5 having a thickness of 0.5 mm and a fiber weight fraction of 33.3 wt% was obtained. Other material properties are shown in Table 1.

(Reference Example 21) Adjustment of molding material 6 In the same manner as in Reference Example 16, the carbon fiber mat 2 obtained in Reference Example 11 and the polypropylene resin film obtained in Reference Example 14 were made to have a length of 500 mm and a width of 500 mm. A molding material 6 having a thickness of 0.5 mm and a fiber weight fraction of 33.3 wt% was obtained. Other material properties are shown in Table 1.

(Reference Example 22) Adjustment of molding material 7 In the same manner as in Reference Example 16, a length of 500 mm, a width consisting of the carbon fiber mat 1 obtained in Reference Example 10 and the nylon 6 resin film obtained in Reference Example 15 A molding material 7 having a thickness of 500 mm, a thickness of 0.5 mm, and a fiber weight fraction of 28.6 wt% was obtained. However, the hot platen surface temperature of the press machine was 250 ° C. Other material properties are shown in Table 1.

(Reference Example 23) Preparation of molding material 8 In the same manner as in Reference Example 16, the length of the glass fiber mat obtained in Reference Example 13 and the polypropylene resin film obtained in Reference Example 14 was 500 mm long, 500 mm wide, A molding material 8 having a thickness of 0.5 mm and a fiber weight fraction of 64.9 wt% was obtained. Other material properties are shown in Table 2.

(Reference Example 24) Preparation of molding material 9 In the same manner as in Reference Example 16, the length of the glass fiber mat obtained in Reference Example 13 and the polypropylene resin film obtained in Reference Example 14 was 500 mm long, 500 mm wide, A molding material 9 having a thickness of 2.0 mm and a fiber weight fraction of 2.7 wt% was obtained. Other material properties are shown in Table 2.

Reference Example 25 Preparation of Molding Material 10 90% by mass of the unmodified polypropylene resin of Reference Example 7 and 10% by mass of the acid-modified polypropylene resin of Reference Example 8 were prepared and dry blended. After the dry blend product was melted and kneaded with a 200 ° C. twin screw extruder, the chopped carbon fiber bundle 2 obtained in Reference Example 3 was charged from the side feeder of the extruder and further kneaded. After melt-kneading with the extruder, it was extruded from a T-shaped die (500 mm width). Then, it cooled and solidified by taking up with a 60 degreeC chill roll, and obtained the CF / PP sheet of thickness 0.5mm.

  Next, press molding was performed using the same method as in Reference Example 16 to obtain a molding material 10 having a length of 500 mm, a width of 500 mm, a thickness of 2.0 mm, and a fiber weight fraction of 33.3 wt%. Other material properties are shown in Table 2.

Reference Example 26 Preparation of Molding Material 11 In the same manner as Reference Example 25, a length of 500 mm, a width consisting of the chopped carbon fiber bundle 2 obtained in Reference Example 3 and the nylon 6 resin obtained in Reference Example 9 A molding material 11 having a thickness of 500 mm, a thickness of 2.0 mm, and a fiber weight fraction of 28.6 wt% was obtained. However, the hot platen surface temperature of the press machine was 250 ° C. Other material properties are shown in Table 2.

Reference Example 27 Preparation of Molding Material 12 A release sheet (Teflon (registered trademark), thickness 1 mm) was placed on a metal tool plate, and the polypropylene resin film obtained in Reference Example 14 was placed on top. Arranged. The chopped carbon fiber bundles 4 of Reference Example 5 were randomly scattered on the polypropylene resin film, and it was visually confirmed that the carbon fiber bundles were distributed in a random direction. Furthermore, the polypropylene resin film obtained in Reference Example 14, the release sheet, and the tool plate were arranged in that order.

  Next, press molding was performed using the same method as in Reference Example 16 to obtain a molding material 12 having a length of 500 mm, a width of 500 mm, a thickness of 2.0 mm, and a fiber weight fraction of 57.1 wt%. Other material properties are shown in Table 2.

Reference Example 28 Single-character Rib Molding Mold A pair of opposed molds for obtaining a molded product having a shape composed of a face plate and a single-character rib shown in FIG. 1, and having the dimensions shown below. The dimensions of the upper mold (opening mold) and the lower mold (opposing mold) are shown in FIGS.
Fig. 10: W1; 2mm, W2; 199mm, W3; 199mm, W4; 400mm, W5; 500mm, W6; 200mm, W7; 300mm, H1; 10mm, H2; 20mm, H3;
FIG. 11: W1; 392 mm, W2; 500 mm, W3; 192 mm, W4; 300 mm, H1; 7 mm, H2; 150 mm

Reference Example 29 Cross Rib Mold A pair of opposed molds having a shape composed of a face plate and a cross rib shown in FIG. 12, and having the dimensions shown below. The dimensions of the upper mold (opening mold) and the lower mold (opposing mold) are shown in FIGS.
FIG. 13: W1; 2 mm, W2; 199 mm, W3; 199 mm, W4; 400 mm, W5; 500 mm, W6; 200 mm, W7; 300 mm, W8; 2 mm, H1;
FIG. 11: W1; 392 mm, W2; 500 mm, W3; 192 mm, W4; 300 mm, H1; 7 mm, H2; 150 mm
Example 1
The molding material 1 obtained in Reference Example 16 and the molding material 10 obtained in Reference Example 25 were used. Here, from the concentration parameter p of the molding material 1 and the molding material 10, the molding material 1 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B). The molding material 1 and the molding material 10 were cut into the following dimensions to prepare 8 molding materials 1 and 10 molding materials 10.
Molding material 1: length 440mm, width 220mm
Molding material 10: length 200 mm, width 20 mm
Next, 10 molding materials 10 were placed on the two molding materials 1 at positions directly above the ribs as preforms of the molding material. This laminate is designated as preform 1A. Moreover, the laminated body which laminated | stacked two molding materials 1 was used as the preform 1B, and three bodies were prepared. As the molding die, Reference Example 27 was used, and the die temperature was adjusted to 80 ° C.

  Each preform was placed individually in an oven equipped with a far infrared heater and preheated for 10 minutes. After confirming that the temperature of the thermocouple installed in the molding material of each preform has reached 210 ° C., two preforms 1A and two preforms 1B are placed on the preform 1B in the oven. Laminated to make a preform 1C.

  Next, the preheated preform 1C is disposed on the convex portion of the lower mold, and after confirming that the molding material 10 is disposed immediately above the rib, the upper mold is lowered, Press molding was performed at a pressure of 20 MPa. After pressing and cooling for 3 minutes in this state, the upper mold was raised to obtain a molded body. Although a trace of faintness was seen in a part of the rib part, the others had a good surface appearance, and no warpage was found in the obtained molded product. Furthermore, the rib was completely filled with the material, and no resin rich portion was observed. Properties and evaluation results are summarized in Table 3.

(Example 2)
The molding material 1 obtained in Reference Example 16 and the molding material 10 obtained in Reference Example 25 were used. Here, from the concentration parameter p of the molding material 1 and the molding material 10, the molding material 1 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B). The molding material 1 and the molding material 10 were cut into the following dimensions to prepare four molding materials 1 and one molding material 10.
Molding material 1: length 440mm, width 220mm
Molding material 10: length 440 mm, width 220 mm

  Next, two preforms 2A were prepared as the preforms of the molding material. As a molding die, Reference Example 23 was used, and the die temperature was adjusted to 80 ° C.

  Two preforms 2A and the molding material 10 were individually placed in an oven equipped with a far-infrared heater and preheated for 10 minutes. After confirming that the temperature of the thermocouple installed in the molding material of each preform has reached 210 ° C., two preforms 2A are stacked in the oven, and then the molding material 10 is laminated, and the preform 2B It was.

  Next, the preheated preform 2B was placed on the convex portion of the lower mold, and then the upper mold was lowered and press molded at a surface pressure of 20 MPa. After pressing and cooling for 3 minutes in this state, the upper mold was raised to obtain a molded body. The warpage of the face plate of the obtained molded product was slightly large. However, the rib part was completely filled, and it was good without a faint trace and resin richness. Properties and evaluation results are summarized in Table 3.

(Example 3)
Preform, preheating and molding are performed in the same manner as in Example 2 except that the molding material 10 obtained in Reference Example 25 is placed on the convex portion of the lower mold and the preform 2A is placed thereon. A molded product was obtained. The obtained molded product had a slightly larger warp on the face plate. Moreover, although the rib part was completely filled, a faint trace was seen in a part of the surface. Properties and evaluation results are summarized in Table 3.

Example 4
Preform 2A is arranged on the convex part of the lower mold and the molding material 10 obtained in Reference Example 25 and the preform 2A are arranged in this order on the preform 2A. Then, preheating and molding were performed to obtain a molded product. There was almost no warp in the face plate portion of the obtained molded product, and the surface appearance was good. In addition, although a faint trace was seen in a part of the rib portion, the filling was sufficient. Properties and evaluation results are summarized in Table 3.

(Example 5)
In the same manner as in Example 1, the molding material 1 obtained in Reference Example 16 and the molding material 10 obtained in Reference Example 25 were cut. However, the molding material 1 was cut into a size of 320 mm in length and 200 mm in width, and 10 sheets were prepared.

  Next, 10 molding materials 10 were arranged on the four molding materials 1 at positions directly above the ribs as preforms of the molding material. This laminate is designated as preform 5A. Moreover, the laminated body which laminated | stacked three molding materials 1 was used as the preform 5B, and two bodies were prepared. As a molding die, Reference Example 23 was used, and the die temperature was adjusted to 80 ° C.

  Each preform was placed individually in an oven equipped with a far infrared heater and preheated for 10 minutes. After confirming that the temperature of the thermocouple installed in the molding material of each preform reached 210 ° C., the preform 5A was laminated on the preform 5B in an oven to obtain a preform 5C.

  Next, the preheated preform 5C is placed on the convex portion of the lower mold, and after confirming that the molding material 10 is placed at the rib position, molding is performed in the same manner as in Example 1, and molding is performed. I got a product. The rib was completely filled although there was a resin rich part. Further, the isotropicity of the face plate portion was slightly low. Properties and evaluation results are summarized in Table 3.

(Example 6)
The molding material 5 obtained in Reference Example 20 and the molding material 10 obtained in Reference Example 25 were used. Here, from the concentration parameter p of the molding material 5 and the molding material 10, the molding material 5 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B).

  Except that the molding material 5 was used instead of the molding material 1, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. Some faint marks were seen on the face plate. The rib was completely filled although there was a resin-rich part. Properties and evaluation results are summarized in Table 4.

(Example 7)
The molding material 6 obtained in Reference Example 21 and the molding material 10 obtained in Reference Example 25 were used. Here, from the concentration parameter p of the molding material 6 and the molding material 10, the molding material 6 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B).

  Except that the molding material 6 was used instead of the molding material 1, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. Although a faint trace was seen in a part of the rib portion, the face plate had a good surface appearance. Also, no warpage was found on the face plate. Furthermore, the rib was completely filled with the material, and no resin rich portion was observed. Properties and evaluation results are summarized in Table 4.

(Example 8)
The molding material 3 obtained in Reference Example 18 and the molding material 10 obtained in Reference Example 25 were used. Here, from the concentration parameter p of the molding material 3 and the molding material 10, the molding material 3 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B).

  Except that the molding material 3 was used instead of the molding material 1, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. In the obtained molded product, a faint trace was seen in a part of the rib part, but the other was a good surface appearance, and the warp of the top plate was hardly seen. Furthermore, the rib was completely filled with the material, and no resin rich portion was observed. However, the top plate was slightly less isotropic. Properties and evaluation results are summarized in Table 4.

Example 9
The molding material 4 obtained in Reference Example 19 and the molding material 10 obtained in Reference Example 25 were used. Here, from the concentration parameter p of the molding material 4 and the molding material 10, the molding material 4 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B).

  Except that the molding material 4 was used instead of the molding material 1, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. In the obtained molded product, faint marks were seen on the top plate and part of the rib portion. Moreover, the warp of the top plate was not seen, and the isotropic property was excellent. Furthermore, the rib was completely filled with the material, and no resin rich portion was observed. Properties and evaluation results are summarized in Table 4.

(Example 10)
Except that the molding material 10 has a length of 200 mm and a width of 2 mm, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. Although the surface appearance of the top plate was good, resin richness was seen in the ribs. Others were good molded products. Properties and evaluation results are summarized in Table 4.

(Example 11)
Except that the molding material 10 has a length of 200 mm and a width of 60 mm, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. There was a faint trace in part of the rib, but it was completely filled. The surface appearance of the top plate was good. Properties and evaluation results are summarized in Table 5.

(Example 12)
Except that the molding material 10 has a length of 200 mm and a width of 140 mm, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. There was a faint trace in part of the rib, but it was completely filled. However, the top plate was slightly less isotropic. Properties and evaluation results are summarized in Table 5.

(Example 13)
The molding material 1 obtained in Reference Example 16 and the molding material 10 obtained in Reference Example 25 were used. Here, from the concentration parameter p of the molding material 1 and the molding material 10, the molding material 1 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B). The molding material 1 and the molding material 10 were cut into the following dimensions to prepare seven molding materials 1-1, two molding materials 1-2, and ten molding materials 10.
Molding material 1-1: length 440mm, width 220mm
Molding material 1-2: length 190mm, width 200mm
Molding material 10: length 200 mm, width 20 mm

  Next, as a molding material preform, ten molding materials 10 were placed on the one molding material 1-1 at a position directly above the ribs. Further, one molding material 1-2 was placed on both sides where the molding material 10 was placed, and it was placed after confirming that the molding materials did not overlap. This laminate is designated as preform 13A. Moreover, the laminated body which laminated | stacked two molding materials 1-1 was used as the preform 13B, and three bodies were prepared. As a molding die, Reference Example 23 was used, and the die temperature was adjusted to 80 ° C.

  Each preform was placed individually in an oven equipped with a far infrared heater and preheated for 10 minutes. After confirming that the temperature of the thermocouple installed in the molding material of each preform has reached 210 ° C., the preform 11A is laminated on one preform 11B in an oven, and the preform 11B is further laminated. A laminate of two bodies was designated as preform 13C.

  Next, the preheated preform 13C is placed on the convex portion of the lower mold, and after confirming that the molding material 10 is placed at the position of the rib, molding is performed in the same manner as in Example 1. A molded product was obtained. The top plate portion had a good surface appearance, and no warpage was found in the obtained molded product. Furthermore, although a faint trace was seen in a part of the rib, it was a good molded product that was completely filled and no resin-rich part was seen. Properties and evaluation results are summarized in Table 5.

(Example 14)
First, one sheet obtained by cutting the molding material 1 obtained in Reference Example 16 into a length of 200 mm and a width of 20 mm was further laminated on the molding material 10 to be placed on the preform 13A of Example 13 to obtain a preform 14A. . Except that the preform 14A was used instead of the preform 13A, preheating, preforming and molding were performed in the same manner as in Example 13 to obtain a molded product. Both the top plate and the rib portion had a good surface appearance, and no warpage was found in the obtained molded product. Further, the rib was completely filled with the material, and it was a very good molded product in which no resin rich portion was seen. Properties and evaluation results are summarized in Table 5.

(Example 15)
For the molding material 1-1 cut in Example 13, what was subjected to the cutting process in the area located at the opening position of the opening in the upper mold and the center of the molding material 1-1 was the molding material 1-1. -1. The cut length is 200 mm. Except that the molding material 1-1-1 was used instead of the molding material 1-1, preheating, preforming and molding were performed in the same manner as in Example 14 to obtain a molded product. Both the top plate and the rib portion had a good surface appearance, and no warpage was found in the obtained molded product. Further, the rib was completely filled with the material, and it was a very good molded product in which no resin rich portion was seen. Properties and evaluation results are summarized in Table 5.

(Example 16)
The molding material 3 obtained in Reference Example 18 and the molding material 2 obtained in Reference Example 17 were used. Here, from the concentration parameter p of the molding material 3 and the molding material 2, the molding material 3 is classified into the molding material (A), and the molding material 2 is classified into the molding material (B).

  Preformed, preheated and molded in the same manner as in Example 1 except that the molding material 3 and the molding material 2 were used in place of the molding material 1 and the molding material 10, respectively, to obtain a molded product. The top plate of the obtained molded product had almost no warp and had a good surface appearance. The rib was completely filled although there was a resin rich part. The top plate was slightly isotropic. Properties and evaluation results are summarized in Table 6.

(Example 17)
The end materials of the molding material 1 and molding material 10 cut in Example 1 and the unmodified polypropylene resin of Reference Example 7 were put into a twin screw extruder at 200 ° C. and melt-kneaded. After extruding the kneaded material from a T-die, press molding was performed using a CF / PP film cut into a length of 500 mm and a width of 500 m in the same manner as in Reference Example 25, and a length of 500 mm consisting of reinforcing fibers and a thermoplastic resin. A molding material 13 having a width of 500 mm and a thickness of 2.0 mm was obtained. The material properties are shown in Table 6.

  Except that the molding material 1 obtained in Reference Example 16 and the molding material 13 were used, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. Here, from the concentration parameter p of the molding material 1 and the molding material 13, the molding material 1 is classified as a molding material (A), and the molding material 13 is classified as a molding material (B). Both the top plate and the rib portion had good surface appearance, and no warpage was found in the obtained molded product. Further, the rib was completely filled with the material, and was a good molded product in which no resin-rich portion was seen. Properties and evaluation results are summarized in Table 2.

(Example 18)
The molding material 1 obtained in Reference Example 16 and the molding material 2 obtained in Reference Example 17 were used. Here, from the concentration parameter p of the molding material 1 and the molding material 2, the molding material 1 is classified into the molding material (A), and the molding material 2 is classified into the molding material (B).

  Except that the molding material 2 was used instead of the molding material 10, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. The face plate portion had no warpage and had a good surface appearance with no blurring on the surface. In addition, although a faint trace was seen in a part of the rib portion, the filling was sufficient. Properties and evaluation results are summarized in Table 6.

(Example 19)
The molding material 1 obtained in Reference Example 16 and the molding material 12 obtained in Reference Example 27 were used. Here, from the concentration parameter p of the molding material 1 and the molding material 12, the molding material 1 is classified into the molding material (A), and the molding material 12 is classified into the molding material (B).

  Except that the molding material 11 was used instead of the molding material 10, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. The face plate portion had almost no warpage and had a good surface appearance with no blurring on the surface. In addition, although a faint trace was seen in a part of the rib portion, the filling was sufficient. Properties and evaluation results are summarized in Table 6.

(Example 20)
Except that the molding material 7 obtained in Reference Example 22 and the molding material 11 obtained in Reference Example 26 were used, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. The far-infrared heater was adjusted so that the temperature of the molding material was 250 ° C. Here, from the concentration parameter p of the molding material 7 and the molding material 10, the molding material 7 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B). In the obtained molded product, a faint trace was seen in a part of the rib part, but the other was a good surface appearance, and no warp was seen. Further, the rib was completely filled with the material, and was a good molded product in which no resin-rich portion was seen. Properties and evaluation results are summarized in Table 6.

(Example 21)
Preformed, preheated and molded in the same manner as in Example 1 except that the molding material 8 obtained in Reference Example 23 and the molding material 9 obtained in Reference Example 24 were used, and a molded product was obtained. Here, from the concentration parameter p of the molding material 7 and the molding material 8, the molding material 7 is classified into the molding material (A), and the molding material 8 is classified into the molding material (B). The obtained molded product had a good surface appearance on the top plate, but resin-rich was seen in the ribs. Properties and evaluation results are summarized in Table 7.

(Example 22)
A preform was obtained by performing preforming, preheating and molding in the same manner as in Example 1 except that press molding was performed at a surface pressure of 5 MPa. The obtained molded product had good surface appearance and warpage of the face plate portion. The rib portion was completely filled although a resin rich portion was generated. Properties and evaluation results are summarized in Table 7.

(Example 23)
Except for press molding at a surface pressure of 35 MPa, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. Although the obtained molded product was slightly inferior in bending strength, both the surface appearance and warpage of the face plate portion were good. Further, the rib portion was satisfactory because it was completely filled with no trace of fading. Properties and evaluation results are summarized in Table 7.

(Example 24)
Except for press molding at a surface pressure of 50 MPa, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. Although the obtained molded product was slightly inferior in the in-plane variation in bending strength and bending strength, both the surface appearance and warpage of the face plate portion were good. Further, the rib portion was satisfactory because it was completely filled with no trace of fading. Properties and evaluation results are summarized in Table 7.

(Example 25)
In the form of the preform 1C of Example 1, it was preheated in an oven equipped with a far infrared heater. It took 20 minutes for the temperature of the thermocouple installed in the preform 1C to reach 210 ° C. Using the preheated preform 1C, molding was performed in the same manner as in Example 1. The obtained molded article had no trace of faintness on the top plate and almost no warpage occurred. Although a faint trace was seen in a part of the rib part, it was completely filled. Properties and evaluation results are summarized in Table 7.

(Example 26)
In the same manner as in Example 1, one preform 1A and three preforms 1B of Example 1 were individually placed in an oven equipped with a far infrared heater and preheated for 10 minutes. After confirming that the temperature of the thermocouple installed in the molding material of each preform has reached 210 ° C, a preform 1D or a preform obtained by laminating the preform 1A on the preform 1B in the oven A laminate of two 1Bs was designated as preform 1E.

  Next, the preheated preform 1D is placed on the convex portion of the lower mold, and after confirming that the molding material 10 is placed at the rib position, the preheated preform 1E is placed on the preform 1D. After placement, the upper mold was lowered and press-molded at a surface pressure of 20 MPa. At this time, when the upper mold and the molding material 1 were in contact, the surface temperature of the molding material 1 was 170 ° C., which was lower than 190 ° C. in Example 1. After pressing and cooling for 3 minutes in this state, the upper mold was raised to obtain a molded body. Some faint marks were seen on the face plate. Moreover, although the resin rich part had arisen in the rib, it was complete filling. Properties and evaluation results are summarized in Table 8.

(Example 27)
The molding material 1 obtained in Reference Example 16 and the molding material 10 obtained in Reference Example 25 were used. Here, from the concentration parameter p of the molding material 1 and the molding material 10, the molding material 1 is classified into the molding material (A), and the molding material 10 is classified into the molding material (B). The molding material 1 and the molding material 10 were cut into the following dimensions to prepare 16 molding materials 1 and 10 molding materials 10.
Molding material 1: length 210mm, width 220mm
Molding material 10: length 200 mm, width 20 mm

  Next, four preforms 27A were prepared as laminates of four molding materials 1 as preforms of the molding material, and four bodies were prepared. Moreover, the laminated body which laminated | stacked two molding materials 10 was used as the preform 27B, and five bodies were prepared. As the molding die, Reference Example 27 was used, and the die temperature was adjusted to 80 ° C.

  Each preform was placed individually in an oven equipped with a far infrared heater and preheated for 10 minutes. After confirming that the temperature of the thermocouple installed in the molding material of each preform reached 210 ° C., two preforms 27A were laminated in an oven, and this was designated as preform 27C. Further, five preforms 27B were laminated to produce a preform 27D.

  Next, the preheated preform 27D was disposed on the opening of the lower mold, and then the preform 27C was disposed on both sides thereof so as not to overlap the preform 27D. Thereafter, the upper mold was lowered and press-molded at a surface pressure of 20 MPa. After pressing and cooling for 3 minutes in this state, the upper mold was raised to obtain a molded body. The rib portion was completely filled although a resin rich portion was observed. In addition, some warping occurred in the top plate portion of the obtained molded product. Properties and evaluation results are summarized in Table 8.

(Example 28)
Except that five molding materials 10 were used, a preform was obtained in the same manner as in Example 1 to perform preforming, preheating and molding. The top plate portion had a good surface appearance, and no warpage was found in the obtained molded product. Moreover, although the resin rich part was seen to the rib part, it was completely filled. Properties and evaluation results are summarized in Table 8.

(Example 29)
Except that the cross rib molding die of Reference Example 29 was used, preforming, preheating and molding were performed in the same manner as in Example 15 to obtain a molded product. However, the molding material 10 disposed in the opening was cut into a size matched to the cross-shaped opening. After confirming that the molding materials did not overlap, a preform was prepared. The top plate of the obtained molded product had almost no warp and had a good surface appearance. The rib was completely filled although there was a resin rich part. The top plate was slightly isotropic. Properties and evaluation results are summarized in Table 8.

(Example 30)
Except that the molding material 13 was used as the molding material (B), preforming, preheating and molding were performed in the same manner as in Example 29 to obtain a molded product. The top plate of the obtained molded product had almost no warp and had a good surface appearance. The rib was completely filled with no resin-rich part. The top plate was slightly isotropic. Properties and evaluation results are summarized in Table 11.

(Example 31)
The preform, preheating and molding were performed in the same manner as in Example 17 except that a cut having a cut length of 200 mm was made in the region located at the opening position of the opening in the upper mold of the molding material (A). A molded product was obtained. The top plate of the obtained molded product had almost no warp and had a good surface appearance. The rib was completely filled with no resin-rich part. The top plate was slightly isotropic. Properties and evaluation results are summarized in Table 11.

(Example 32)
The preform, preheating and molding were performed in the same manner as in Example 19 except that a cut having a cut length of 200 mm was made in the region located at the opening position of the opening in the upper mold of the molding material (A). A molded product was obtained. The top plate of the obtained molded product had almost no warp and had a good surface appearance. The rib was completely filled with no resin-rich part. The top plate was slightly isotropic. Properties and evaluation results are summarized in Table 11.

(Example 33)
The preform, preheating and molding were performed in the same manner as in Example 20 except that a cut having a cut length of 200 mm was made in the region located at the opening position of the opening in the upper mold of the molding material (A). A molded product was obtained. The top plate of the obtained molded product had almost no warp and had a good surface appearance. The rib was completely filled with no resin-rich part. The top plate was slightly isotropic. Properties and evaluation results are summarized in Table 11.

(Comparative Example 1)
Only the molding material 1 obtained in Reference Example 16 was used. The molding material 1 was cut into dimensions of 440 mm in length and 220 mm in width to prepare 8 sheets.

  Next, four laminates in which two molding materials 1 were laminated were prepared as preforms for the molding material. As the molding die, Reference Example 27 was used, and the die temperature was adjusted to 80 ° C.

  In the same manner as in Example 1, each preform was individually placed in an oven equipped with a far infrared heater and preheated for 10 minutes. After confirming that the temperature of the thermocouple installed in each laminate reached 210 ° C., four laminates were laminated in order.

  Next, the laminate was placed on the convex portion of the lower mold, the upper mold was lowered, and press-molded at a surface pressure of 20 MPa. After pressing and cooling for 3 minutes in this state, the upper mold was raised to obtain a molded body. The surface appearance of the face plate of the obtained molded product was good and almost no warp was seen, but the isotropic property of the face plate portion was somewhat inferior. Furthermore, the filling of the rib portion and the fiber filling rate were insufficient, and the fiber filling rate was not sufficient. Properties and evaluation results are summarized in Table 9.

(Comparative Example 2)
Only the molding material 10 obtained in Reference Example 25 was used. Except that the molding material 10 was cut into dimensions of 440 mm in length and 220 mm in width and two sheets were prepared, preheating and molding were performed in the same manner as in Comparative Example 1 to obtain a molded product. The surface appearance of the face plate of the obtained molded product was good, and almost no warpage was seen. However, the bending strength of the face plate was poor. The filling of the ribs and the surface appearance were good. Properties and evaluation results are summarized in Table 9.

(Comparative Example 3)
Only the molding material 1 obtained in Reference Example 16 was used. Except that the molding material 1 was used instead of the molding material 10, preforming, preheating and molding were performed in the same manner as in Example 1 to obtain a molded product. The surface appearance of the face plate of the obtained molded product was good, and no warp was seen. Further, the isotropy of the top plate was superior to that of Comparative Example 1. However, the rib was completely filled although there was a resin-rich part. Moreover, the fiber filling rate was inferior. Properties and evaluation results are summarized in Table 9.

(Comparative Example 4)
The molding material 3 obtained in Reference Example 18 and the molding material 4 obtained in Reference Example 19 were used. Here, the molding material 3 and the molding material 4 are classified into the molding material (A) from the concentration parameter p of the molding material 3 and the molding material 4.

  Preformed, preheated and molded in the same manner as in Example 1 except that the molding material 3 and the molding material 4 were used in place of the molding material 1 and the molding material 10, respectively, to obtain a molded product. The surface appearance of the face plate of the obtained molded product was good, and almost no warpage was seen. Moreover, the face plate was excellent in isotropy. However, the rib portion was insufficiently filled and the resin richness was conspicuous. Properties and evaluation results are summarized in Table 9.

(Comparative Example 5)
In the same manner as in Example 1, the molding material 1 obtained in Reference Example 16 and the molding material 10 obtained in Reference Example 25 were cut. However, the molding material 1 was cut into a size of 200 mm in length and 200 mm in width, and 16 sheets were prepared.

  Next, 10 molding materials 10 were placed on the two molding materials 1 at positions directly above the ribs as preforms of the molding material. This laminate is designated as preform 4A. Moreover, the laminated body which laminated | stacked two molding materials 1 was used as the preform 4B, and seven bodies were prepared. As a molding die, Reference Example 23 was used, and the die temperature was adjusted to 80 ° C.

  Each preform was placed individually in an oven equipped with a far infrared heater and preheated for 10 minutes. After confirming that the temperature of the thermocouple installed in each preform has reached 210 ° C., three preforms 4B are laminated in an oven, and then preform 4A is laminated, and further, preform 4B is laminated thereon. A four-layer laminate was designated as Preform 4C.

  Next, the preheated preform 4C is placed on the convex part of the lower mold, and after confirming that the molding material 10 is placed at the position of the rib, molding is performed in the same manner as in Example 1, and molding is performed. I got a product. A faint trace was observed on the face plate surface of the obtained molded product. Also, the ribs were hardly filled. Furthermore, the top plate was inferior in isotropy. Properties and evaluation results are summarized in Table 9.

(Comparative Example 6)
Preform and preheating were performed in the same manner as in Example 1 except that the temperature of the molding material during preheating was 140 ° C. When the preform after preheating was confirmed, the polypropylene resin contained in the molding material was not melted and could not be molded. Properties and evaluation results are summarized in Table 10.

(Comparative Example 7)
Except that the mold temperature was 30 ° C., preforming, preheating and molding were performed in the same manner as in Example 20 to obtain a molded product. The face plate portion of the obtained molded product is generally faint and inferior in appearance. The rib portion was completely filled although a trace of faintness was seen in part. Properties and evaluation results are summarized in Table 10.

(Comparative Example 8)
Except that the mold temperature was 210 ° C., preforming, preheating and molding were performed in the same manner as in Example 20 to obtain a molded product. The face plate portion of the obtained molded product was generally faint and inferior in appearance. Moreover, the in-plane variation of bending strength was inferior. The rib portion was completely filled although a trace of faintness was seen in part. Properties and evaluation results are summarized in Table 10.

  Unlike conventional methods, when laminating discontinuous reinforcing fibers and sheet-shaped molding materials containing thermoplastic resin, and press molding, the surface appearance and dimensional accuracy are achieved by using two or more types of molding materials with different configurations. Thus, a molded product having a rib structure can be obtained in which the formation of a highly reliable face plate portion and the formation of a rib structure are compatible. Therefore, the molded article obtained by the present invention can be suitably used for parts / members used for automobiles, electrical / electronic devices, household electrical appliances, or aircraft.

1 Concave mold of single-character rib molding mold 2 Convex mold of single-character rib molding mold 3 Opening (shaded area)
4-1, 4-2, 4-3, 4-4, 4-5, 4-6, 4-7, 4-8, 7, 8 Monofilaments 5-1, 5-2, 5-3, 5 -4, 5-5, 5-6, 5-7, 5-8 Fiber bundles 6-1, 6-2, 9 Flow unit 10 Projection surface (shaded part) of molded product
11 Projection surface of the opening (shaded area)
12 Two-dimensional orientation angle

Claims (23)

A sheet-shaped molding material (A) containing discontinuous reinforcing fibers and a thermoplastic resin and having a concentration parameter p represented by the following general formula (1) of 1 × 10 ⁴ or more and 1 × 10 ⁸ or less A discontinuous reinforcing fiber and a thermoplastic resin, the concentration parameter p represented by the following general formula (1) is 1 × 10 ¹ or more, and the concentration parameter of the molding material (A) is 0.1. A preform containing a sheet-like molding material (B) that is not more than double is press-molded using an opening mold having an opening for forming a rib structure and an opposing mold facing the preform, thereby forming a rib structure. In manufacturing a molded product having, a molding having a rib structure in which the area of the molding material (A) is 70% or more of the projected area of the molded product, and the molding material (B) is disposed at the projected position of the opening. Product manufacturing method.
n: Number of flow units made of reinforcing fibers per unit area (1 mm ² ) of molding material h: Thickness of molding material (mm)
Ln: number average fiber length of reinforcing fibers (mm) The method for producing a molded article having a rib structure according to claim 1, wherein the press molding includes the following steps (I) to (IV).
Step (I): A step of heating the preform above the softening temperature or melting point of the thermoplastic resin contained in the preform.
Step (II): A step of transporting the preform heated in Step (I) and placing it in a mold.
Step (III): A step of pressurizing and cooling the preform by clamping a mold having a temperature lower by 20 ° C. to 150 ° C. than the softening temperature or melting point of the thermoplastic resin.
Step (IV): A step of opening the mold after cooling and taking out the molded product from the mold. The method for producing a molded product having a rib structure according to claim 1 or 2, wherein the preform is formed by laminating the molding material (A) and the molding material (B). The manufacturing method of the molded article which has the rib structure of Claim 3 which arrange | positions the said preform so that the said molding material (A) may become an opposing metal mold | die side. The method for producing a molded article having a rib structure according to claim 4, wherein the molding material (B) is laminated on an intermediate layer of a preform, and the molding material (A) is also disposed on the opening mold side. . The molded article having a rib structure according to any one of claims 1 to 5, wherein the number average fiber length Lb of the reinforcing fibers contained in the molding material (B) is not more than twice the rib thickness Tr of the rib structure. Manufacturing method. The manufacturing method of the molded article which has a rib structure in any one of Claims 1-6 whose area of the said molding material (B) is 1-50 times the opening area of the said opening part. The said molding material (A) is arrange | positioned between the said molding material (B) and the said opening metal mold | die, The said molding material (A) has a penetration part in the area | region of the projection surface of the said opening part. The manufacturing method of the molded article which has a rib structure in any one of 1-7. The manufacturing method of the molded article which has a rib structure in any one of Claims 1-8 whose area of the said molding material (A) is larger than the projected area of the said molded article. The manufacturing method of the molded article which has the rib structure in any one of Claims 1-9 whose total volume Vb of the molding material (B) contained in the said preform is larger than the cavity volume Vr of the said opening part. At a temperature 35 ° C. higher than the softening temperature or melting point of the thermoplastic resin, the elongation rate R (%) of the molding material (A) is 100% or more and less than 350%, and the elongation rate R (%) of the molding material (B). The manufacturing method of the molded article which has a rib structure in any one of Claims 1-10 which are 350% or more and less than 1000%. The reinforcing fiber contained in the molding material (A) is an average of two-dimensional orientation angles formed by the reinforcing fiber single yarn (a) and the reinforcing fiber single yarn (b) intersecting the reinforcing fiber single yarn (a). The method to manufacture the molded article which has a rib structure using the preform in any one of Claims 1-11 whose value is 10-80 degree | times. The said molding material (A) is a manufacturing method of the molded article which has the rib structure in any one of Claims 1-12 whose maximum tensile strength (sigma) Max by a measurement direction is 2 times or less of minimum tensile strength (sigma) Min. The reinforcing fiber contained in the molding material (A) is a method for producing a molded article having a rib structure according to any one of claims 1 to 13, wherein the number average fiber length is 2 to 20 mm. The method for producing a molded article having a rib structure according to any one of claims 1 to 14, wherein the reinforcing fibers contained in the molding material (B) have a number average fiber length of 0.1 to 2 mm. The manufacturing method of the molded article which has the rib structure in any one of Claims 1-15 in which the said molding material (B) contains the end material obtained in the process of manufacturing or processing the said molding material (A). The manufacturing method of the molded article which has a rib structure in any one of Claims 1-16 in which the said molding material (A) contains the molding raw material of thickness 0.1-1 mm as a lamination | stacking unit. The manufacturing method of the molded article which has a rib structure in any one of Claims 1-17 whose said reinforced fiber is a polyacrylonitrile-type carbon fiber. At the time of the mold clamping in the step (III), when the preform and the mold approaching the preform come into contact, the surface temperature of the preform on the approaching mold side is the softening temperature or melting point of the thermoplastic resin. The manufacturing method of the molded article which has a rib structure of Claim 2 higher than 20 degreeC. The method for producing a molded article having a rib structure according to claim 2, wherein the pressure applied to the projection surface of the molded article in the step (III) is in the range of 10 to 40 MPa. In the step (I), the molding material (A) and / or the molding material (B) constituting the preform is divided in a thickness range of 0.1 to 10 mm and heated separately to soften the thermoplastic resin. The method for producing a molded article having a rib structure according to claim 2, wherein the temperature or melting point is set. The manufacturing method of the molded article which has the rib structure of Claim 2 including the process of forming the preform of the last form between the said process (I) and the said process (II). The rib according to any one of claims 1 to 22, wherein the obtained molded product has a rib structure height Hr (mm) that is at least three times the face plate thickness H0 (mm) accompanied by the rib structure. A method for producing a molded article having a structure.