JP2006044262A - Hollow molded article and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hollow molded article having a light weight and excellent dynamic characteristics in which both of formation of complicated shapes and producibility can be realized at the same time by making the 1st member composed of FRP and the 2nd member into a strongly integrated structure. <P>SOLUTION: In the hollow molded article, the 1st member 11 and the 2nd member 12 are made integrated, and at least the 1st material is composed mainly of a thermosetting resin 16 reinforced by a continuous reinforcing fibers 14 and contains a thermoplastic resin layer 13 at the joint part with the 2nd member, wherein the thermoplastic resin layer incorporates a part of the reinforcing fiber, or, as an alternative, the 1st member composed mainly of a thermosetting resin reinforced by a continuous reinforcing fibers and the 2nd member mainly composed of a thermoplastic resin are made integrated to form a hollow structure, and in those articles, the 1st member has a surface shape which constitutes at least one surface of the molded article, and the 2nd member constitutes a surface opposite to the 1st member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hollow molded body in which a hollow shape is formed by integrating two members and a manufacturing method thereof, and more specifically, a fiber reinforced resin (FRP) reinforced with a continuous reinforcing fiber group is firmly integrated. Therefore, the present invention relates to a hollow molded article that is excellent in light weight and mechanical properties, and has both a moldability of a complicated shape and productivity, and a method for manufacturing the same.

  Fiber reinforced resin (FRP) reinforced with continuous reinforcing fiber groups is used for transportation equipment such as aircraft, automobiles, motorcycles and bicycles, sports applications such as tennis, golf and fishing rods, construction structures such as seismic reinforcement, etc. It is frequently used as a material for structures requiring light weight and mechanical properties.

  In particular, FRP hollow moldings are very applicable to aircraft structures, vehicle structures, automobile parts, bicycle cranks, tanks and pipes for storing or transporting gas and liquid, golf shafts, fishing rods, windmill blades, etc. wide.

  Here, among hollow molded bodies, for example, a hollow molded body having a simple shape, such as a golf shaft or a pressure vessel, with a relatively small opening, is obtained by winding a reinforcing fiber bundle impregnated with resin around a rotating liner. It can be suitably produced by a so-called reinforcing fiber winding method for curing. Although this manufacturing method is relatively inexpensive and high in productivity, the target is limited to the shape of a rotating body, and it is difficult to apply to a complicated shape.

  Among hollow molded products, for example, automobile monocoque bodies and large hollow molded products with a somewhat complicated shape such as aircraft structural materials are shaped by injecting uncured resin by shaping the fiber base into a mold. Further, it can be produced by a so-called resin transfer molding (RTM) molding method in which a substrate is impregnated and then cured. Patent Document 1 discloses a method of manufacturing a hollow body having a non-circular cross-sectional shape using a core. However, this method is suitable for producing a large-sized molded product in a small amount, but productivity is a problem for mass-producing the molded product.

Therefore, it is possible to manufacture a non-hollow FRP molded product or a hollow molded product having a complicated shape by joining a plurality of hollow FRP molded products having relatively large openings, but generally using a known adhesive The man-hours and lead time required for the bonding process lead to an increase in cost and a decrease in productivity, and above all, the bonding strength cannot be sufficiently exhibited, and the characteristics of the FRP such as high strength and high rigidity are impaired. In addition, mechanical joining methods such as bolts and screws not only require a separate machining process, but also have limitations in design and limited application, and above all, the characteristics of FRP such as lightness are impaired. is there.
International Publication No. 2000/18566 pamphlet (page 39, line 22)

  In view of the prior art, an object of the present invention is to provide a hollow molded body that is lightweight and excellent in mechanical characteristics by firmly integrating the first member made of FRP and the second member. is there. It is another object of the present invention to provide a bonding method that is excellent in bonding strength and can achieve both the moldability and productivity of complex shapes.

  In order to solve the above problems, a hollow molded body according to the present invention is a hollow molded body in which a hollow shape is formed by integrating at least two members of a first member and a second member, At least the first member of the members is mainly composed of a thermosetting resin reinforced with a continuous reinforcing fiber group, and has a thermoplastic resin layer at a joint portion with the second member. The layer comprises a part of the reinforcing fibers of the reinforcing fiber group (hereinafter also referred to as the first invention).

  In addition, the hollow molded body according to the present invention is formed by integrating a first member mainly composed of a thermosetting resin reinforced with a group of continuous reinforcing fibers and a second member mainly composed of a thermoplastic resin. A hollow molded body in which a hollow shape is formed, wherein the first member has a planar shape, forms at least one surface of the molded body, and the second member serves as the first member. It consists of what is characterized by forming the surface which opposes (henceforth a 2nd invention).

  Furthermore, in the method for producing a hollow molded body according to the present invention, when producing the hollow molded body as described above, the first member and the second member are thermally welded, vibration welded, ultrasonic welded, laser welded. And at least one method selected from insert injection molding and outsert injection molding.

  The hollow molded body according to the present invention can firmly integrate the first member made of the FRP molded body with the second member, thereby providing excellent lightness and mechanical properties. Moreover, even in a complicated shape, it can be manufactured with high productivity by an inexpensive method. Therefore, these hollow molded bodies are suitable for applications such as tanks, pipes, windmill blades, automobile members, and bicycle cranks.

Below, the hollow molded object of this invention and its manufacturing method are demonstrated in detail with desirable embodiment.
The hollow molded body of the present invention is a structure having a hollow shape. The hollow shape means a shape having a substantially internal space, such as a shell shape, a drum shape, or a cylindrical shape. There are no particular restrictions on the shape of the internal space. For example, there may be ribs or bosses inside it, and it may be divided into several spaces by partitions, etc., and the opening that connects the internal space and the external space A part may be provided. The opening can be used as a doorway for a person or a person's hand to go in and out, to load or unload a baggage, or to store grains, liquid, gas, or the like inside.

  There is no particular restriction on the size of the internal space, but it is hollow molding from the viewpoint of storing and moving the contents, making the internal space function effectively, and reducing the specific gravity of the molded product. The maximum thickness of the hollow part in the body is preferably 10 mm or more, and more preferably 20 mm or more. Here, the thickness of the hollow portion refers to the maximum surface that represents the shape of the molded product in the internal space formed by the first member and the second member, and is disposed so as to face the surface. It means the height sandwiched between the faces. This may be confirmed by subtracting the thickness of each member from the thickness of the molded product. Moreover, when it has several space height, the length which becomes the largest space height is defined as the maximum thickness.

  Although there is no restriction | limiting in particular also in the external shape of the hollow molded object of this invention, the direction which is a non-rotating body shape rather than a rotating body shape is preferable at the point applicable to a more various use. Note that the non-rotating body shape here includes a symmetrical shape and a vertically symmetric shape.

  The hollow molded body of the present invention is one in which the hollow shape is formed by integrating at least two members. There are no particular restrictions on the method of forming the hollow shape. For example, two U-shaped members may be combined vertically or horizontally, a plurality of planar members and curved members may be connected, and the hollow shape may be formed inside. A beam may be formed, or a canopy may be formed on the box-shaped member.

  Furthermore, the interior space consists of urethane foam, polystyrene foam, polyethylene foam, polypropylene foam, phenol foam, urea foam, polyvinyl chloride foam, silicon foam, epoxy foam, polyimide foam, polyester foam, melamine foam, and fibrous material. You may arrange lightweight foam materials, such as a foam structure.

  Here, one embodiment of the hollow molded body according to the present invention will be described with reference to FIG. The hollow molded body is composed of a first member 1 and a second member 2.

  In the hollow molded body of the first invention, at least the first member among the members is mainly composed of a thermosetting resin reinforced with a continuous reinforcing fiber group, and a thermoplastic resin is bonded to the second member. A hollow molded body having a layer, wherein the thermoplastic resin layer includes a part of the reinforcing fibers of the reinforcing fiber group. In FIG. 2, the example of the junction part of the 1st member 3 and the 2nd member 4 is shown as a figure which expanded the cross section. FIG. 2 is a diagram created based on a photograph obtained by using a scanning electron micrograph. In FIG. 2, the first member 3 is mainly composed of a large number of continuous reinforcing fibers 5 a and 5 b and a thermosetting resin 6. And it has the thermoplastic resin layer 7 in the junction part with the 2nd member 4, and this thermoplastic resin layer 7 includes a group (part) reinforcement fiber 5b. Here, it is preferable that the thermoplastic resin layer 7 has an uneven shape at the interface with the thermosetting resin 6 and is integrated.

  The hollow molded body of the second aspect of the present invention is an integrated first member mainly composed of a thermosetting resin reinforced with a group of continuous reinforcing fibers and a second member mainly composed of a thermoplastic resin. It is the hollow molded object which formed the hollow shape by doing. When the second member is made of a thermoplastic resin, not only heat welding is possible, but also a structure for joining such as a boss, a hinge, and a fitting portion can be easily formed and processed. This first member is formed into a surface shape, and at least one surface of the molded body is formed, and the second member is formed to form a surface facing the first member, thereby producing a hollow molded body integrally. It can be manufactured with good performance.

  In the hollow molded body of the second invention, it is practically preferable that the first member and the second member are bonded to each other at the joint surface. As a bonding method, a general thermoplastic or thermosetting adhesive may be used. As a more preferable bonding mode, the first member is heated at a bonding portion with the second member. It has a plastic resin layer, and the thermoplastic resin layer is bonded by including some reinforcing fibers of the continuous reinforcing fiber group. The aspect of these more preferable joining parts is the same as that described in FIG.

  In the hollow molded body of the present invention, the structure of the first member 3 as shown in FIG. 2 is that the thermosetting resin before curing is added to the reinforcing fiber group 8 composed of a large number of continuous reinforcing fibers 5a and 5b. A base material formed by processing a thermoplastic resin is placed on the prepreg or prepreg laminate that has been impregnated, and the base material thermoplastic resin during the curing reaction of the thermosetting resin or during preheating before the curing reaction Can be formed by impregnating the reinforcing fiber group 8. Further, the thermosetting resin 6 forms a thermosetting resin layer, and the thermoplastic resin forms a thermoplastic resin layer 7. The layer of the thermosetting resin 6 and the thermoplastic resin are impregnated into the reinforcing fiber group 8 of the thermoplastic resin, that is, by penetration of the thermoplastic resin between a large number of reinforcing fibers 5b forming the reinforcing fiber group 8. The uneven shape of the interface with the resin layer 7 is formed.

  As the prepreg, a prepreg composed of a plurality of reinforcing fiber groups 8 as necessary and arranged in the width direction of the prepreg or laminated in the thickness direction of the prepreg is used. In FIG. 2, the reinforcing fiber group 8 that is located in the outermost layer in the prepreg and is closest to the joint surface with the second member 4 is shown.

  Here, the reinforcing fiber group is composed of a large number of reinforcing fibers continuous in a length of 10 mm or more in at least one direction. The reinforcing fiber group does not need to be continuous over the entire length in the length direction of the first member or over the entire width in the width direction of the first member, and may be divided in the middle.

  The reinforcing fiber group includes a reinforcing fiber bundle composed of a large number of reinforcing fibers, a cloth composed of the fiber bundle, a reinforcing fiber bundle in which a large number of reinforcing fibers are arranged in one direction (unidirectional fiber bundle), A unidirectional cloth composed of directional fiber bundles. Among these, from the viewpoint of prepreg and member productivity, a cloth and a unidirectional fiber bundle are preferable. The reinforcing fiber group may be composed of a plurality of fiber bundles having the same form, or may be composed of a plurality of fiber bundles having different forms. The number of reinforcing fibers constituting one reinforcing fiber group is usually 300 to 48,000, but in consideration of the production of prepreg and the production of cloth, it is preferably 300 to 24,000, more preferably 1,000 to 12,000.

  Moreover, as a preferable aspect of a 1st member, it is the laminated body by which the fiber bundle was laminated | stacked in layers. By changing the orientation direction of the reinforcing fiber group and laminating, the mechanical properties of the entire member can be controlled. Moreover, the sandwich form by which another base material is laminated | stacked between the lamination | stacking of the laminated | stacked reinforcing fiber group as needed is also used.

  The structure of the 1st member in the hollow molded object of this invention can be verified with the following method, for example. First, the first test method is based on observation of a partial cross section of a surface layer of a member joint by a scanning electron microscope (SEM) or a transmission electron microscope (TEM). The observation of the cross section may be performed based on the taken cross-sectional photograph, if necessary. The test piece to be observed is a thin slice created using the surface layer portion cut out from the member. In making this, some of the reinforcing fibers of the reinforcing fiber group may fall off, but there is no problem as long as the observation is not affected. The test piece may be stained as necessary to adjust the contrast of observation.

  The reinforcing fibers constituting the reinforcing fiber group are usually observed as a circular cross section. When the reinforcing fiber is dropped, it is usually observed as a circular drop mark. In the portion other than the portion where the reinforcing fibers constituting the reinforcing fiber group are located, the thermosetting resin layer and the thermoplastic resin layer are observed as two regions having different contrasts.

  An example of the observation result by the first method is shown in FIG. FIG. 3 is an enlarged view of the cross section of the joint surface of the hollow molded body in which the first member 11 and the second member 12 are integrated. The state in which the resin of the thermoplastic resin layer 13 has entered into the gap between the multiple reinforcing fibers 15a and 15b constituting the reinforcing fiber group 14 is shown. The state where the interface 17 with the plastic resin layer 13 has an uneven shape is shown.

  The second test method is based on observation with a scanning electron microscope (SEM) or a transmission electron microscope (TEM) of a cross section in which the thermoplastic resin in the surface layer portion of the member joint is extracted and removed with a solvent. The observation of the cross section may be performed based on a cross-sectional photograph as necessary. The member is cut to a length of about 10 mm and a width of about 10 mm to obtain a test piece. In this test piece, the thermoplastic resin layer is sufficiently washed with a good solvent for the resin constituting the test piece, and the thermoplastic resin is removed to prepare a test piece for observation. The cross section of the prepared test piece is observed using SEM (or TEM).

  An example of the observation result by the second method is shown in FIG. FIG. 4 shows an enlarged cross section of the joint surface in a state where the second member and the thermoplastic resin layer are removed from the hollow molded body in which the first member 18 and the second member 19 are integrated. Is. In FIG. 4, the thermosetting resin 20 exists with the reinforcing fibers 22 a constituting the reinforcing fiber group 21, but the thermoplastic that has existed with the thermosetting resin 20 and the uneven interface 23. The resin layer does not exist because it is removed by the solvent when the test piece is prepared. While the uneven shape of the interface 23 is observed, the reinforcing fiber 22b constituting the reinforcing fiber group 21 is observed at the position where the thermoplastic resin layer was present, and the void 24 is observed between these reinforcing fibers. The This proves that the reinforcing fiber 22b constituting the reinforcing fiber group 21 was included in the thermoplastic resin layer.

  In the first method and the second method, when observing the member joint portion from the integrated hollow molded body, the joint portion is peeled off by heating to a temperature at which the resin of the thermoplastic resin layer is plasticized, You may process by the method of removing a 2nd member mechanically.

  The third test method is based on observation of a state obtained when the other is forcibly peeled from one to the other in an integrated molded product. This test method is performed by forcibly peeling the integrally molded product at room temperature so as to break between the first member and the second member. A part of the surface layer of the first member may adhere as a residue to the peeled second member. This residue is observed with a microscope.

  An example of the state of the test piece obtained by implementing the third test method is shown in FIG. In FIG. 5, a joining portion 26 where the surface of the first member is joined is shown in the second member 25, and a part of the first member surface layer portion remains in the joining portion 26. As observed. In this residue 27, it is observed that there are a plurality of reinforcing fibers dropped from the reinforcing fiber group located on the surface layer of the first member.

  The structural characteristics of the hollow molded body of the present invention can be verified by the at least one test method described above.

  The first member in the hollow molded body of the present invention is a region in which the continuous reinforcing fibers 5b exist in the thermoplastic resin layer 7 shown in FIG. 2 for the purpose of increasing the adhesive strength with the second member. The maximum thickness Tpf-max is preferably 10 μm or more, more preferably 20 μm or more, and further preferably 40 μm or more. This maximum thickness Tpf-max is the outermost (bonding side) reinforcing fiber 5b-out in contact with the resin of the thermoplastic resin layer 7 in the thickness direction of the thermoplastic resin layer 7, and the thermoplastic resin layer 7 Is defined as a distance (Tpf-max) between the innermost reinforcing fiber 5b-in-max in contact with the resin of the thermoplastic resin layer 7 at the portion where the penetration depth from the surface of the resin is the largest. The The maximum thickness Tpf-max can be measured in the SEM or TEM photograph obtained by the first test method or the second test method. If the maximum thickness Tpf-max is 1,000 μm at the maximum, the effect of the present invention is sufficiently achieved.

  The minimum thickness Tpf-min is the outermost (surface side) reinforcing fiber 5a-out in contact with the resin of the thermoplastic resin layer 7 in the thickness direction of the thermoplastic resin layer 7, and the thermoplastic resin layer 7 It is defined as the distance (Tpf-min) between the innermost reinforcing fiber 5b-in-min in contact with the resin of the thermoplastic resin layer 7 at the portion where the penetration depth from the resin surface is the smallest. .

  In the first member, as shown in FIG. 2, the interface 9 between the thermosetting resin 6 and the thermoplastic resin layer 7 is a reinforcing fiber composed of a large number of reinforcing fibers 5a and 5b aligned in one direction. It is preferably present in group 13. In the first member, in the case where a plurality of reinforcing fiber groups 13 are laminated in the thickness direction, it is more preferable that the interface 9 exists only in the outermost reinforcing fiber group.

  In order to obtain an excellent adhesive effect when the hollow molded body of the present invention is joined to the second member to form an integrally molded product, the thermoplastic resin layer provided on the surface of the first member It is necessary to be joined to the second member. The area S of the thermoplastic resin layer provided on the surface of the first member is appropriately determined according to the area where the bonding force with the second member to be bonded can be secured.

  That is, in the hollow molded body of the present invention, it is preferable that the first member and the second member are bonded via a film made of a thermoplastic resin composition constituting the thermoplastic resin layer. The average thickness of the coating film formed on the first member is preferably 0.01 to 1,000 μm, more preferably 0.1 to 200 μm, and still more preferably 1 to 50 μm. The average thickness Tp of the coating is the outermost (bonding side) reinforcing fiber 5b-out in contact with the resin of the thermoplastic resin layer 7 shown in FIG. 2, the first member 3 and the second member 4. It is defined by the distance to the bonding interface 10 of When the thickness of the film is not constant, measurement is performed at an arbitrary number of points, and the average value of the obtained measured values is defined as the thickness of the film. When the average thickness is in the above preferable range, the first member and the second member are more reliably joined.

  Examples of the reinforcing fiber group and / or the fiber material of the reinforcing fiber used in the hollow molded body of the present invention include glass fiber, carbon fiber, metal fiber, aromatic polyamide fiber, polyaramid fiber, alumina fiber, and silicon carbide fiber. Boron fiber, basalt fiber. These are used alone or in combination of two or more. These fiber materials may be subjected to surface treatment. Examples of the surface treatment include a metal deposition treatment, a treatment with a coupling agent, a treatment with a sizing agent, and an additive adhesion treatment. Among these fiber materials, conductive fiber materials are also included. As the fiber material, carbon fiber having a small specific gravity, high strength and high elastic modulus is preferably used.

  In the hollow molded body of the present invention, examples of the thermosetting resin used for the first member include unsaturated polyester, vinyl ester, epoxy, phenol (resol type), urea melamine, polyimide, There are coalesced, modified and blended resins of at least two of these. In order to improve the impact resistance, an elastomer or a rubber component may be added to the thermosetting resin. In particular, the epoxy resin is preferable from the viewpoint of the mechanical characteristics of the first member.

  In the hollow molded body of the present invention, the thermoplastic resin forming the thermoplastic resin layer used for the first member preferably has a solubility parameter δ (SP value) of 9 to 16, more preferably 10 -15, particularly preferably 11-14. By setting it within the above range, the cohesive force of the thermoplastic resin is large, and it is effective in increasing the adhesive strength which is one of the objects of the present invention.

  Examples of the thermoplastic resin that can achieve the solubility parameter δ include amide bonds, ester bonds, urethane bonds, ether bonds, amino groups, hydroxyl groups, carboxyl groups, acid anhydride groups, sulfonic acid groups, aromatic rings, imide rings, and the like. And those having a bond, functional group or structure having a polarity higher than that of the hydrocarbon skeleton.

  Moreover, as a weight average molecular weight of a thermoplastic resin, 2,000-200,000 are preferable, 5,000-150,000 are more preferable, 10,000-100,000 are still more preferable. By setting it within the above range, intermolecular forces and entanglement of molecular chains increase, and the strength of the thermoplastic resin itself increases, so that the thermoplastic resin itself is not easily broken, and at the same time, the thermoplastic resin is sufficient. The reinforcing fiber group can be impregnated, and by including the fiber group, a strong adhesive force can be expressed.

Furthermore, in the hollow molded body of the present invention, the thermoplastic resin forming the thermoplastic resin layer used for the first member is selected from a carboxyl group, an acid anhydride group, an amino group, an epoxy group, and a hydroxyl group. By containing at least one kind of functional group, the reactivity of the thermoplastic resin is increased, and this is effective in increasing the adhesive strength, which is one of the objects of the present invention. Among these, an acid anhydride group, an amino group, and an epoxy group are more preferably selected. Here, the functional group amount of the thermoplastic resin is preferably 1 × 10 ⁻⁵ mol / g or more, more preferably 1 × 10 ⁻⁴ mol / g or more, and further preferably 1 × 10 ⁻³ mol / g or more. The amount of the functional group is not particularly limited and can be measured by a general chemical analysis method. For example, the components are identified by IR (infrared absorption spectrum measurement), the molecular structure is identified by NMR (nuclear magnetic resonance spectrum measurement), and the molecular weight is identified by GPC (gel permeation chromatography). From the obtained result, the number of moles of the functional group per unit weight of the polymer chain can be calculated.

  As described above, in the hollow molded body of the present invention, examples of the thermoplastic resin composition used for the first member include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), and polyethylene naphthalate. In addition to phthalate (PEN), polyester such as liquid crystal polyester, modified polyethylene (PE), modified polypropylene (PP), modified polyolefin such as polybutylene, styrenic resin, polyoxymethylene (POM), polyamide (PA), Polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), polyphenylene ether (PPE), modified PPE, polyimide (PI), polyamideimide (PAI) Polyetherimide (PEI), Polysulfone (PSU), Modified PSU, Polyethersulfone, Polyketone (PK), Polyetherketone (PEK), Polyetheretherketone (PEEK), Polyetherketoneketone (PEKK), Polyarylate ( PAR), polyether nitrile (PEN), phenolic resin, phenoxy resin, polytetrafluoroethylene and other fluorine resins, polystyrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, polyisoprene, Fluorine-based thermoplastic elastomers and the like, copolymers, modified products, and resins obtained by blending at least two of them can be used. Among these, polyester resins, polyamide resins, and modified polyolefin resins are preferably used from the viewpoints of productivity and economy.

  In order to improve impact resistance, an elastomer or a rubber component may be added to the thermoplastic resin, and a filler or an additive may be added from the viewpoint of improving functionality. For example, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, coloring inhibitors, heat stabilizers, mold release agents, antistatic agents Plasticizers, lubricants, colorants, pigments, dyes, foaming agents, antifoaming agents, and coupling agents. In particular, when an inorganic substance is added, a smaller dispersion size is more preferable from the viewpoint of impregnation into the reinforcing fiber group. In particular, those having a nano-order dispersion size are more preferable from the viewpoint that the effect can be exhibited by addition of a small amount.

  In the hollow molded body of the first aspect of the present invention, the second member is not particularly limited as long as it is made of a material having thermal adhesiveness at the joint portion with the first member.

  For example, the second member is a member having substantially the same configuration as the first member, and the one in which the thermoplastic resin layer is disposed at the joint is from the viewpoint of manufacturing a hollow molded body having excellent mechanical characteristics. preferable.

  Moreover, if the 2nd member is a member comprised from the thermoplastic resin composition, it is preferable from a viewpoint which can shape | mold a more complicated shape. There is no restriction | limiting in particular as a thermoplastic resin to be used, This can be illustrated similarly as a thermoplastic resin used for a 2nd member in the hollow molded object of this 2nd invention. For example, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polyester such as liquid crystal polyester, polyethylene (PE), polypropylene (PP), polybutylene, etc. In addition to polyolefins and styrene resins, polyoxymethylene (POM), polyamide (PA), polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), polyphenylene ether ( PPE), modified PPE, polyimide (PI), polyamideimide (PAI), polyetherimide (PEI), polysulfone (PSU), modified PSU, polyethersulfone, polyketo (PK), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyarylate (PAR), polyethernitrile (PEN), phenolic resin, phenoxy resin, polytetrafluoro Fluorine-based resins such as ethylene, polystyrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polybutadiene-based, polyisoprene-based, fluorine-based thermoplastic elastomers, copolymers thereof, modified products, and the like A resin obtained by blending at least two of these can be used. An elastomer or a rubber component may be added to the thermoplastic resin in order to improve impact resistance. In particular, PPS resin is economical from the viewpoint of heat resistance and chemical resistance, polycarbonate resin and styrene resin are from the viewpoint of molded product appearance and dimensional stability, and polyamide resin is economical from the viewpoint of molded product strength and impact resistance. From this point of view, a polyolefin resin is preferably used.

  About the 2nd member used for this invention, it is preferable that the reinforcement fiber is contained in the thermoplastic resin from a viewpoint of the intensity | strength of a hollow molded object, rigidity, and dimensional stability. Examples of such reinforcing fibers include polyacrylonitrile-based, rayon-based, lignin-based, pitch-based carbon fibers, graphite fibers, glass fibers, aluminum fibers, brass fibers, stainless fibers, and other metal fibers, silicon carbide fibers, and siliconite. There are inorganic fibers such as ride fibers. The fiber length of the reinforcing fiber is not particularly limited, but the number average fiber length is preferably in the range of 0.1 to 60 mm, more preferably in the range of 0.3 to 30 mm, and particularly preferably in the range of 1 to 20 mm. Moreover, there is no restriction | limiting in particular also in content of a reinforced fiber, The inside of the range of 1-90 weight% is preferable, The inside of the range of 10-70 weight% is more preferable, The inside of the range of 20-60 weight% is especially preferable.

These fiber length and fiber content can be measured by a generally known method. For example, a test piece is cut out from the second member with a length of 10 mm and a width of 10 mm. The prepared test piece is immersed in a solvent in which the thermoplastic resin is soluble for 24 hours to dissolve the resin component. The reinforcing fiber is extracted from the test piece in which the resin component is dissolved. The obtained reinforcing fibers are observed with a microscope, and the fiber length is measured for N pieces of randomly extracted reinforcing fibers. If N number is 400 or more, there will be no restriction | limiting in particular. When each fiber length is Li, the number average fiber length is calculated based on the following formula.
Number average fiber length = (ΣLi) / (N)

  Further, the content can be measured from the weight of the extracted reinforcing fiber and the weight of the test piece. When the thermoplastic resin is hardly soluble or insoluble in the solvent, a method of extracting the reinforcing fiber by removing the thermoplastic resin by heating may be used.

  Furthermore, a filler and an additive may be added to the thermoplastic resin from the viewpoint of enhancing functionality. For example, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, coloring inhibitors, heat stabilizers, mold release agents, antistatic agents Plasticizers, lubricants, colorants, pigments, dyes, foaming agents, antifoaming agents, and coupling agents.

  There is no restriction | limiting in particular in the molding material which has the said thermoplastic resin as a main component, The pellet for injection molding, a stampable sheet, and the thermoplastic sheet for high pressure molding can be illustrated. Among these, long fiber pellets and thermoplastic sheet materials are more preferably used from the viewpoint of maintaining the fiber length of the reinforcing fibers at 1 mm or more.

  Furthermore, if the 2nd member is a member which consists of metal materials, it is preferable from a viewpoint which improves robustness. The metal material may be a metal material obtained by subjecting aluminum, iron, magnesium, titanium, an alloy thereof, or the like to a heat-adhesive surface treatment.

In the hollow molded article of the present invention, integrated by molding or after the use environment, from the viewpoint of suppressing the dimensional change and warpage of occurrence of the molded article, the maximum linear expansion coefficient CIImax surface direction of the second member 4 × 10 ^- It is preferably ⁵ or less, more preferably 1 × 10 ⁻⁵ or less. Similarly, from the viewpoint of suppressing twisting of the molded product, the ratio between the maximum linear expansion coefficient CIImax and the minimum linear expansion coefficient CIImin in the surface direction of the second member, CIImax / CIImin is 1.8 or less. Preferably, it is 1.5 or less.

  The linear expansion coefficient can be measured based on ISO 11359-2. For a part randomly selected from the molded product, four test pieces cut out at different angles such as 0 degrees, 45 degrees, 90 degrees, and 135 degrees with respect to the longitudinal direction of the member are prepared. As for the cutout position of the test piece, portions where shapes such as ribs, hinges, and concavo-convex portions are intentionally avoided should be avoided as much as possible. In these test pieces, the maximum value is defined as the maximum linear expansion coefficient CIimax, and the minimum value is defined as the minimum linear expansion coefficient CIimin. In addition, although there is no restriction | limiting in particular in a measurement temperature range, 30-200 degreeC can be illustrated as a preferable range from a viewpoint of the environment where a molded article is used.

  Furthermore, from the viewpoint of the rigidity and dimensional stability of the hollow molded article, the flexural modulus based on ISO 179 of the second member is preferably 10 GPa or more, and more preferably 12 GPa or more. For the measurement of the flexural modulus, four test pieces cut out at different angles such as 0 degrees, 45 degrees, 90 degrees, and 135 degrees from the flat part of the molded product with reference to the longitudinal direction of the member. Prepare. It is preferable to cut out the test piece while avoiding a portion where the shape is intentionally provided such as a rib portion, a hinge portion, and an uneven portion. When these intentionally shaped parts are included in the test piece, the thickness of the test piece is measured excluding this part. The minimum value of the flexural modulus obtained in these test pieces is defined as the flexural modulus.

  The method for integrating the hollow molded body of the present invention is not particularly limited. For example, the manufacturing method includes joining the second member at a temperature equal to or higher than the melting point or softening point of the thermoplastic resin layer or coating film constituting the first member, bonding, and then cooling.

  The procedure in the joining is not particularly limited. For example, (i) a method in which the first member is molded in advance and the second member is molded at the same time as the second member is joined and integrated; (ii) the second member is molded in advance; A method of joining and integrating the two at the same time as forming the one member, or (iii) forming the first member and the second member separately in advance, and joining and integrating the two. Can be applied.

  As a method of integration, a method of mechanically fitting and integrating the first member and the second member, a method of integrating both using mechanical coupling means such as bolts and screws, both There is also a technique of integrating the materials using chemical bonding means such as an adhesive. These methods for integrating may be used in combination as necessary.

  As a specific example of the integration method (i), the first member is press-molded, processed or post-processed into a predetermined size as necessary, then inserted into an injection mold, and then the second member. There is a technique of injection molding a material for forming a mold into a mold.

  As a specific example of the integration method (ii), the second member is press-molded or injection-molded, processed or post-processed into a predetermined size as necessary, and then inserted into a press mold, and then the press mold Laying up a base material with a thermoplastic resin layer formed on the surface of a prepreg consisting of an uncured thermosetting resin forming a first member and a group of continuous reinforcing fibers, with a mold as a predetermined process temperature Then, there is a method of molding at a temperature equal to or higher than the melting point of the thermoplastic resin.

  As a specific example of the integration method (iii), the first member is press-molded, prepared by processing or post-processing to a predetermined size as necessary, and the second member is separately molded in advance. There is a method of integrating each by heat welding, vibration welding, ultrasonic welding and the like in the same manner as the integration method (ii). Further, if any member has laser permeability, it can be integrated by laser welding.

  Among the integration methods as described above, insert injection molding and outsert injection molding in the integration method (i) are preferably used from the viewpoint of mass productivity of the hollow molded body. In particular, it is preferable to apply blow molding to form a hollow shape. From the viewpoint of shape stability and precision of the bonded portion, the above-mentioned integration method (iii) is preferably used, and heat welding, vibration welding, ultrasonic welding, and laser welding can be preferably used.

  Further, in the production of the hollow molded body of the present invention, the first member forms a curved surface with a radius of curvature of 1000 m or less from the viewpoint of efficiently performing integration and at the same time increasing the degree of freedom of shape. It may be. More preferably, it is within 500 m, and a plurality of these curved surfaces may be formed intermittently or intermittently in one surface of the molded product. Further, a diaphragm having a radius of curvature of 5 mm or more may be formed in these planes.

  On the other hand, the second member may be formed with a three-dimensional shape in the thickness direction. For example, the second member has a structure having irregularities from the functional surface, a structure having irregularities from the design surface, and assists mechanical joining. Bosses, ribs, hinges, fitting structures, and the like may be formed.

  As a use of the hollow molded article of the present invention, there is a product in a field that is lightweight and requires mechanical properties. For example, pipes such as tanks, intake manifolds, pumps, instrument panels, interior materials, spoilers, pillars, door panels, bonnets, engine covers, automobile parts such as various beams and shock absorbers, structures such as windmill blades, cowls, bicycle cranks Aircraft parts such as motorcycles, bicycle parts, landing gear pods, monocoques, winglets, spoilers, edges, ladders, elevators, failings, ribs, parabolic antennas, laptop computers, mobile phones, digital still cameras, PDAs, Parts, members and casings of electric or electronic devices such as portable MDs and plasma displays, telephones, facsimiles, VTRs, photocopiers, televisions, irons, hair dryers, rice cookers, microwave ovens, audio equipment, vacuum cleaners, toilets -Household or office product parts represented by articles, laser discs, compact discs, lighting, refrigerators, air conditioners, typewriters, word processors, parts and housings, game or entertainment product parts such as pachinko machines, slot machines, game machines, Components and housings, microscopes, binoculars, cameras, watches and other optical equipment, precision machine parts, members and housings, medical applications such as X-ray cassettes, tennis rackets, golf club heads, boards, yachts and other sports-related parts And building material parts and panels.

  Among these, tanks, pipes, windmill blades, bicycle cranks, golf club heads, notebook computer cases, X-ray cassettes, automobile members, and building material panels are highly demanded for light weight and high rigidity, and are preferably used.

  Based on an Example, this invention is demonstrated further more concretely. Unless otherwise specified, the blending ratio (%) shown in the examples is a value based on% by weight. The components used in the examples of the present invention are shown below.

Reference example 1
Pellets of ternary copolymer polyamide resin (manufactured by Toray Industries, Inc., ternary copolymer polyamide resin CM4000, polyamide 6/66/610, melting point 150 ° C., solubility parameter δ (SP value) 13.3), It processed into the nonwoven fabric-like tape of 80 g / m < ² > of fabric weight.

Reference example 2
Polyamide 6 (manufactured by Toray Industries, Inc., polyamide 6 resin CM1001) was processed into a powder having a particle diameter of 10 to 1000 μm, and chopped carbon fibers (Toray Industries, Inc., trading card TW12, fiber length 6 mm) were mixed in a dry manner. The mixture was vacuum-dried at 80 ° C. for 3 hours and then press-molded at 250 ° C. to obtain a sheet-like molded body having a carbon fiber content of 30% by weight. The molded article had a maximum coefficient of linear expansion of 1.2 × 10 ⁻⁵ and a minimum coefficient of linear expansion of 0.9 × 10 ⁻⁵ . The flexural modulus was 16 GPa.

Example 1
By explaining using FIG. 6, this embodiment can be explained more clearly.
Ten prepreg sheets having a predetermined shape were cut out from a prepreg impregnated with a group of carbon fibers arranged in one direction with an epoxy resin (thermosetting resin) (Treka prepreg P6053-12 manufactured by Toray Industries, Inc.). As shown in FIG. 6, these 10 sheets are sequentially laminated along the female mold 29 so as to be [0 ° / 90 °] 5 s with respect to the longitudinal direction of the molded product (prepreg laminate 30), Furthermore, the nonwoven fabric-like tape 28 prepared in Reference Example 1 was arranged at a joint portion having a width of 10 mm (arranged nonwoven fabric-like tape 31).

  Next, a male mold (not shown) was set and press molding was performed. In a press molding machine, preheating was performed at 160 ° C. for 5 minutes, and the thermosetting resin was cured by heating at 150 ° C. for 30 minutes while applying a pressure of 5 MPa. After the curing, the first member 32 made of a laminate having a thickness of 1.2 mm was formed by cooling at room temperature and removing the mold. The site | part which has arrange | positioned the said nonwoven fabric tape 31 of the shape | molded 1st member 32 is formed in the junction part 33 with a 2nd member.

  The first member 32 made of the obtained laminate is inserted into an injection mold and inserted using long fiber pellets (TLP1146S manufactured by Toray Industries, Inc., carbon fiber content 20 wt%, polyamide resin matrix). A canopy portion 36a, an opening portion 36b, and a gripping portion 36c were formed on the laminate, and a hollow molded body 34 having an opening portion shown in FIG. 6 was manufactured. A portion 35 of the hollow molded body 34 is the first member. Injection molding was performed using a J350EIII injection molding machine manufactured by Nippon Steel Works, and the cylinder temperature was 280 ° C.

  The obtained integrated molded product 34 was in contact with at least the joint portion 33 on which the nonwoven fabric tape was disposed, and was firmly integrated. A joint portion was cut out from this integrated molded article, dissolved in formic acid for 12 hours to remove the thermoplastic resin portion, and a test piece for cross-sectional observation was obtained. When the test piece was observed with a scanning electron microscope (SEM), a state in which the carbon fiber group was exposed was observed. Furthermore, a two-layer structure of a carbon fiber group having a gap in the bonding surface direction of the laminate 32 and a carbon fiber group having no gap in the opposite direction was observed, and was continuous as shown in FIG. It was recognized that the interface between the thermosetting resin reinforced with the reinforcing fiber group and the thermoplastic resin layer has an uneven shape. The void portion of the carbon fiber group is a region in which the reinforcing fibers of the thermoplastic resin layer are included, and when the maximum thickness Tpf and the minimum thickness Tpf-min are measured, the minimum thickness Tpf-min is 30 μm and the maximum thickness. Tpf-max was 60 μm.

  Further, when the cross section of the bonded portion of the laminate 32 was observed with an SEM, the thermoplastic resin was melted and adhered to the surface in the form of a film, and the film thickness was 10 μm.

Example 2
By explaining using FIG. 7, this embodiment can be explained more clearly.
In the same manner as in Example 1, two laminated bodies 37 and 38 (second member 37 and first member 38) constituting the front and back of the wind turbine blade are manufactured. As shown in FIG. 7, at least a bonded portion was subjected to thermocompression bonding at 180 ° C. for 10 minutes to produce a hollow molded body. The obtained integrally molded product was in contact with at least the joint portion 39 on which the nonwoven fabric tape was disposed, and was firmly integrated.

  Similarly, it was recognized that the interface between the thermosetting resin reinforced with the continuous reinforcing fiber group and the thermoplastic resin layer has an uneven shape. Tpf-min was 30 μm, and the maximum thickness Tpf-max was 60 μm.

  Further, when the cross section of the bonded portion of the laminate 38 was observed with an SEM, the thermoplastic resin was melted and adhered to the surface in the form of a film, and the film thickness was 10 μm.

Example 3
The thermoplastic sheet-like molded body prepared by adjusting the second member 37 in Reference Example 2 is manufactured again by press molding. The molded body was preheated with a hot air dryer at 250 ° C. for 10 minutes, and then molded with a 120 ° C. mold at a pressure of 5 MPa. The obtained member was integrated in the same manner as in Example 2.

Example 4
By explaining using FIG. 8, this embodiment can be explained more clearly.
In the same manner as in Example 1, the prepreg was laminated on the female mold, and the non-woven tape was placed on the joint portion 42 having a width of 10 mm. Next, a vacuum bag was formed, preheated at 160 ° C. for 5 minutes, heated at 150 ° C. for 30 minutes to cure the thermosetting resin, and two first laminated bodies (first members) 40a and 40b were manufactured. . Similarly, two second laminates (second members) 41a and 41b were manufactured by press molding.

  Next, as shown in FIG. 8, the 1st laminated body and the 2nd laminated body were arrange | positioned, and the hollow molded body was manufactured by thermocompression bonding. The obtained integrally molded product was in contact with at least the joint portion 42 on which the nonwoven fabric tape was disposed, and was firmly integrated. Similarly, it was recognized that the interface between the thermosetting resin reinforced with the continuous reinforcing fiber group and the thermoplastic resin layer has an uneven shape. Tpf-min was 30 μm, and the maximum thickness Tpf-max was 60 μm.

  Further, when the cross section of the laminate 40a was observed with an SEM, the thermoplastic resin was melted and adhered to the surface in the form of a film, and the film thickness was 10 μm.

Example 5
This embodiment can be described more clearly by using FIG.
In the same manner as in the first embodiment, the two laminated bodies 43 and 44 (the first member 43 and the second member 44) constituting the front and back of the bicycle crank are manufactured. As shown in FIG. 9, at least the bonded portion was subjected to thermocompression bonding at 180 ° C. for 10 minutes to produce a hollow molded body. The obtained integrally molded product was in contact with at least the joint portion 45 on which the nonwoven fabric tape was disposed, and was firmly integrated. Similarly, it was recognized that the interface between the thermosetting resin reinforced with the continuous reinforcing fiber group and the thermoplastic resin layer has an uneven shape. Tpf-min was 30 μm, and the maximum thickness Tpf-max was 60 μm.

  Further, when the cross section of the laminate 44 was observed with an SEM, the thermoplastic resin was melted and adhered to the surface in the form of a film, and the film thickness was 10 μm.

It is sectional drawing of the hollow molded object which concerns on one embodiment of this invention. It is an expanded sectional view of the joined part in the hollow fabrication object of the present invention. It is sectional drawing which shows the result of having observed the hollow molded object of this invention by the 1st test method. It is sectional drawing which shows the result of having observed the hollow molded object of this invention by the 2nd test method. It is a perspective view which shows the result of having observed the hollow molded object of this invention by the 3rd test method. It is explanatory drawing which shows the process and hollow molded object assembly of Example 1 of this invention. It is explanatory drawing which shows the process of Example 2 of this invention, and a hollow molded object assembly. It is a perspective view which shows the hollow molded object assembly of Example 4 of this invention. It is a perspective view which shows the hollow molded object assembly of Example 5 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st member 2 2nd member 3 1st member 4 2nd member 5a, 5b Reinforcing fiber 6 Thermosetting resin 7 Thermoplastic resin layer 8 Reinforcing fiber group 9 Thermosetting resin and thermoplastic resin layer Interface 10 of the first member and the second member 11 First member 12 Second member 13 Thermoplastic resin layer 14 Reinforcing fiber group 15a, 15b Reinforcing fiber 16 Thermosetting resin 17 Thermosetting resin Interface with thermoplastic resin layer 18 1st member 19 2nd member 20 Thermosetting resin 21 Reinforcing fiber group 22a, 22b Reinforcing fiber 23 Interface between thermosetting resin and thermoplastic resin layer 24 Thermoplastic resin layer Existing gap 25 Second member 26 Joint portion with first member 27 Residual 28 Non-woven tape 29 Female mold 30 Prepreg laminate 31 Non-woven tape 32 First member 33 First member and first 2 Joining portion with member 34 Hollow molded body 35 First member 36a Second member canopy portion 36b Second member opening portion 36c Second member gripping portion 37 Second member 38 First member 39 First member 40a, 40b 1st member 41a, 41b 2nd member 42 Joining part of 1st member and 2nd member 43 1st member 44 2nd member 45 1st Part of the member and the second member

Claims (25)

  A hollow molded body in which a hollow shape is formed by integrating at least two members of a first member and a second member, and at least the first member of the members is reinforced with a continuous reinforcing fiber group. A thermoplastic resin layer at the joint portion with the second member, and the thermoplastic resin layer includes a part of the reinforcing fibers of the reinforcing fiber group. The hollow molded object characterized by the above-mentioned.   The hollow molded body according to claim 1, wherein the second member is a member having substantially the same configuration as the first member or a member made of a metal material.   Hollow molding in which a hollow shape is formed by integrating a first member mainly composed of a thermosetting resin reinforced with a group of continuous reinforcing fibers and a second member mainly composed of a thermoplastic resin. The first member has a surface shape, forms at least one surface of the molded body, and the second member forms a surface facing the first member. A hollow molded body.   The hollow molded body according to claim 3, wherein the second member contains reinforcing fibers having a number average fiber length of 0.1 to 60 mm.   The hollow molded body according to claim 3 or 4, wherein the first member and the second member are bonded to each other at a joining surface thereof.   The first member has a thermoplastic resin layer at a joint portion with the second member, and the thermoplastic resin layer includes a part of the continuous reinforcing fiber group. The hollow molded body according to any one of claims 3 to 5.   The hollow molding according to claim 1 or 6, wherein the thermoplastic resin layer is integrated with a thermosetting resin layer reinforced with a group of continuous reinforcing fibers and has an uneven shape at an interface thereof. body.   The hollow molded body according to any one of claims 1, 6, and 7, wherein in the thermoplastic resin layer, a maximum thickness of a region including the reinforcing fibers is 10 µm or more.   The hollow molded body according to claim 8, wherein the maximum thickness is 1,000 μm or less.   The hollow molded body according to any one of claims 1 and 6 to 9, wherein the resin of the thermoplastic resin layer is formed in a film shape at a joint portion with the second member.   The hollow molded object according to claim 10, wherein the average thickness of the coating film is in the range of 0.01 to 1000 µm.   The hollow molded object in any one of Claims 1-11 whose said 1st member is a laminated body.   The hollow molded object in any one of Claims 1-12 whose reinforced fiber used for a said 1st member is carbon fiber.   The hollow molded body according to any one of claims 1 to 13, wherein the thermosetting resin is a resin mainly composed of an epoxy resin.   The hollow molded body according to any one of claims 1 to 14, wherein the thermoplastic resin used for the first member is at least one selected from a polyester resin, a polyamide resin, and a modified polyolefin resin. The hollow molded body according to any one of claims 1 to 15, wherein the second member has a maximum linear expansion coefficient CIImax in a plane direction of 4 x ^10-5 or less.   The hollow molding according to any one of claims 1 to 16, wherein the ratio of the maximum linear expansion coefficient CIImax in the surface direction to the minimum linear expansion coefficient CIImin of the second member, CIImax / CIImin is 1.8 or less. body.   The hollow molded body according to any one of claims 1 to 17, wherein the second member has a flexural modulus of 10 GPa or more.   The hollow molded body according to any one of claims 1 to 18, wherein the hollow molded body has any one of a shell shape, a drum shape, and a cylindrical shape.   The hollow molded object in any one of Claims 1-19 whose maximum thickness of the hollow part in the said hollow molded object is 10 mm or more.   The hollow molded body according to any one of claims 1 to 20, wherein the first member forms a substantially curved surface having a radius of curvature of 1000 m or less.   The hollow molded body according to any one of claims 1 to 21, wherein the first member is formed with a diaphragm having a radius of curvature of 5 mm or more in a plane thereof.   The hollow molded body according to any one of claims 1 to 22, wherein the second member forms a three-dimensional shape in a thickness direction thereof.   The hollow molded body according to any one of claims 1 to 23, wherein the hollow molded body is a tank, a pipe, a windmill blade, or a part, member, or panel for an automobile, a motorcycle, a bicycle, an aircraft, or a building material.   The first member and the second member are integrated by at least one method selected from thermal welding, vibration welding, ultrasonic welding, laser welding, insert injection molding, and outsert injection molding. The manufacturing method of the hollow molded object in any one of 1-24.

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