JP2008114525A - Composite molded article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite molded article having a light weight, a thin thickness and a high strength and superior in high design property and a high scratch resistance and suitable for applications required for these characteristics. <P>SOLUTION: In the composite molded article (I) including a sheet-shape reinforced member (II) and a resin member (III), a hard layer (IV) having a pencil hardness of 2H or more is formed on at least a part of a front surface across a connecting part between the sheet-shape reinforced member (II) and the resin member (III), a gap S of the sheet-shape reinforced member (II) formed with the hard layer (IV) and the resin member (III) is 0-50 μm, and a height difference D between a higher surface and a lower surface thereof is 0-50 μm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is, for example, a composite molded product suitable for applications requiring lightweight, high strength, high rigidity, high designability, and high scratch resistance, which are used as parts and casing parts of personal computers, office automation equipment, mobile phones and the like. About.

  Currently, as portable electronic devices and electronic devices such as personal computers, OA devices, AV devices, mobile phones, telephones, facsimiles, home appliances, and toy products are increasingly required, smaller and lighter weights are required. In order to achieve that requirement, the components that make up the equipment, especially the housing, have been made smaller, lighter and thinner, but when the load is applied from the outside, the housing will bend greatly to contact and destroy the internal components. Since it is necessary to prevent it from occurring, high strength and high rigidity are required. Furthermore, it is also a surface that touches customers as a product, and the appearance is clean (high design), and it is difficult to be damaged during use (high scratch resistance).

Therefore, in order to obtain a high-strength, high-rigidity molded product, a thermoplastic resin sheet containing continuous reinforcing fibers in one direction or a composite injection molded product in which a sheet laminated with the thermoplastic resin is integrated is proposed. However, the pencil hardness of the surface is at most about H, and there is a problem that it is easily scratched during use. Furthermore, for example, although a blow molded product having a hard layer provided on the surface has been proposed (see, for example, Patent Document 2), there is a problem that the strength and rigidity of the molded product itself is inferior.
JP-A-9-272134 Japanese Patent Laid-Open No. 10-330517

  In view of the problems of the prior art, the present invention is lightweight, thin, high-strength, high-rigidity, excellent in design and scratch resistance, and suitable for applications requiring these characteristics. It is an object to provide a composite molded product.

To achieve the above object, the present invention adopts the following configuration. That is,
(1) In the composite molded article (I) including the sheet-like reinforcing member (II) and the resin member (III), at least one of the surfaces straddling the joint between the sheet-like reinforcing member (II) and the resin member (III) A hard layer (IV) having a pencil hardness of 2H or more is formed at the portion, and a gap S between the joint portion between the sheet-like reinforcing member (II) and the resin member (III) on which the hard layer (IV) is formed Is a composite molded article (I), wherein the surface height difference D is 0 to 50 μm.

  (2) The composite molded article (I) according to (1), wherein the resin member (III) is formed by injection molding and has a molding shrinkage in the resin flow direction of 0 to 0.5%.

  (3) The composite molded article (I) according to (1) or (2), wherein the sheet-shaped reinforcing member (II) is a fiber-reinforced layer body including a fiber-reinforced layer in which continuous fibers are arranged in a sheet shape in one direction. ).

  (4) The composite molded article (I) according to (3), wherein the continuous fibers of the fiber reinforced layer include at least carbon fibers.

  (5) The composite molded article according to any one of (1) to (4), wherein the sheet-like reinforcing member (II) and the resin member (III) are joined via the thermoplastic resin composition (V) ( I).

  (6) Absolute value of the difference between the solubility parameter (SP value) δA of the resin constituting the resin member (III) and the solubility parameter (SP value) δB of the resin constituting the thermoplastic resin composition (V) (| δA- The composite molded article (I) according to (5), wherein δB |) is 0 to 1.2.

  (7) A test piece having a thickness of 0.1 to 1.6 mm in flame retardancy based on UL-94 of the sheet-like reinforcing member (II) and the resin member (III) is V-1 or V-0. The composite molded article (I) according to any one of (1) to (6).

  (8) The composite molded article (I) according to (7), wherein the sheet-like reinforcing member (II) and the resin member (III) include at least a phosphorus-based flame retardant.

  (9) The composite molded article (I) according to any one of (1) to (8), wherein the sheet-like reinforcing member (II) includes a matrix resin mainly composed of an epoxy resin.

  (10) The composite molded article (I) according to any one of (1) to (9), wherein the resin member (III) includes reinforcing fibers.

  (11) The composite molded article (I) according to (10), wherein the reinforcing fibers include at least carbon fibers.

  (12) The composite molded article (I) according to any one of (1) to (11), wherein the hard layer (IV) is formed of any one of a photocurable resin, a catalyst curable resin, and an electron beam curable resin. ).

  (13) The composite molded article (I) according to any one of (1) to (12), which is a casing for an electronic device.

  (14) The composite molded article (I) according to (13), which is a notebook personal computer casing.

  (15) The composite molded article (I) according to (13), which is a mobile phone casing.

  The composite molded article of the present invention is lightweight, thin, high-rigidity, high-strength, excellent in design and scratch resistance, and has such characteristics as electrical equipment such as personal computers, displays and portable information terminals, and housings of electronic equipment. Suitable for manufacturing the body and its housing.

  Hereinafter, the present invention will be described in detail with reference to the drawings relating to one embodiment thereof. However, the following embodiments are not intended to limit the present invention in any way, and modifications may be made without departing from the spirit of the present invention. This is the technical scope of the present invention.

  FIG. 1 is a perspective view of a composite molded product (I) according to an embodiment of the present invention.

  FIG. 2 is a cross-sectional view of the composite molded article (I) illustrated in FIG.

  FIG. 3 is a detailed view of part B of the composite molded article (I) illustrated in FIG.

  1, 2, and 3, the composite molded product (I) of the present invention is a sheet-like reinforcement in which continuous fibers provided with one square hole portion and one round hole portion are arranged in a sheet shape in one direction. The surface of the member (II) and the resin member (III), (IIIa), (IIIb), and the sheet-shaped reinforcing member (II) and the resin member (III), (IIIa), (IIIb) The hard layer (IV) having a pencil hardness of 2H or more is partially or entirely formed.

  The reason for providing the hard layer (IV) is to suppress external scratches during use of the composite molded product (I) and maintain high designability. Further, the safety can be improved such that the reinforcing fiber is exposed and cut on the surface due to the surface being damaged and the reinforcing fiber is prevented from being stabbed into a finger or the like and being injured.

  In order to achieve the object, the hard layer (IV) having a pencil hardness of 2H or more is used. The higher the pencil hardness, the better. Depending on the type of the base material for forming the hard layer (IV), the pencil hardness is about 5H at present. In addition, the formation method of the hard layer (IV) is not particularly limited, but it can be cured in a short period of time, has high mass production efficiency, has a small heat history during curing, and has little thermal effect on the molded product. Therefore, it is preferable to form the photocurable resin, the catalyst curable resin, or the electron beam curable resin. Examples of the main components of these photo-curing type, catalyst-curing type, and electron beam curable resins include unsaturated polyester resins, epoxy acrylates, urethane acrylates, polyester acrylates, polyether acrylates, and unsaturated acrylic resins. For example, in a photocurable resin, chlorothioxanthone, isopropylthioxanthone, benzyl, benzophenone, methylbenzyl formate, hexachloroethane, or the like is added as a polymerization initiator as a photopolymerization initiator. In addition, in the case of a catalyst curable resin, for example, benzoyl peroxide, methyl ethyl ketone peroxide, or the like is added as a radical polymerization catalyst to promote curing.

  As shown in FIG. 3, the surface of the composite molded product (I) on which the hard layer (IV) is formed, particularly the joint between the sheet-like reinforcing member (II) and the resin member (III), If there is an elevation difference (level difference) D, the hard layer (IV) becomes non-uniform in that portion, the appearance design is greatly reduced, and the commercial value is impaired. In order to achieve scratch resistance due to the hard layer (IV) while satisfying high designability, the gap S between the joint portions of the sheet-like reinforcing member (II) and the resin member (III) is set to 0 to 50 μm. And preferably 0 to 30 μm. Similarly, the surface height difference D is also 0 to 50 μm, preferably 0 to 30 μm.

  The pencil hardness is measured by the method described in JIS K5400. Further, the gap S and the surface height difference D of the joint were measured with a surface roughness measuring device and set to the maximum height.

  As a method of integrating the sheet-like reinforcing member (II) and the resin member (III), each is manufactured separately beforehand, and then integrated by adhesive, thermal welding, vibration welding, ultrasonic welding, laser welding, thermocompression bonding, etc. However, when manufacturing components separately, it is necessary to manufacture and manage each component with a highly accurate mold in order to achieve the accuracy of the gap and surface height difference. Is extremely low. Therefore, it is preferable from the viewpoint of productivity and dimensional accuracy to provide the resin members (III), (IIIa), and (IIIb) by direct injection molding on the sheet-like reinforcing member (II). However, since the injection resin is shrunk during molding, the injection molded product itself is smaller than the mold size. Therefore, the resin having a large molding shrinkage cannot achieve the accuracy of the gap and the surface height difference. Therefore, the resin member (III) used for injection molding preferably has a molding shrinkage in the resin flow direction of 0 to 0.5%. More preferably, it is 0 to 0.3%. Thereby, the curvature and twist which generate | occur | produce in sheet-like reinforcement member (II) can also be reduced. In addition, by selecting an injection resin containing reinforcing fibers, the molding shrinkage tends to be smaller, the gap and surface height difference can be reduced, and not only warping and twisting are further reduced, but also composite molded products. (I) It is preferable because the overall rigidity can be improved. Furthermore, it is still more preferable to use carbon fibers as reinforcing fibers. The molding shrinkage is measured by the method described in JIS K7152.

  The ratio of the resin member (III) in the composite molded product (I) is preferably the minimum necessary from the viewpoint of molding shrinkage, and is preferably as small as possible. Further, this increases the proportion of the sheet-like reinforcing member (II), which is effective from the viewpoint of strength and rigidity.

  If the gap and the surface height difference are large due to the necessity of enlarging the resin member (III) in shape design, sanding or filling of putty etc. is performed before forming the hardened layer (IV). This can also be dealt with by adjusting the gap and the surface height difference to be small.

  The reason for providing a hole in the sheet-like reinforcing member (II) is that, for example, there is a need to provide a camera lens mounting hole or a logo pedestal with a company name clearly specified in a notebook PC housing. In such cases, generally, holes, notches, and recesses are formed in the sheet-like reinforcing member (II) by drilling, cutting, counterbore, etc., but at this time, a part of continuous reinforcing fibers is cut. For this reason, the processed surfaces of the hole, the notch and the concave portion are not only reinforced by the reinforcing fibers, and the appearance is remarkably deteriorated, but also during the production or use of the molded product, the surface is easily crushed and peeled off. In the worst case, there is a risk of being stabbed into a finger or the like to cause injury, so the safety can be improved by providing resin members (IIIa) and (IIIb) on the processed surfaces of the hole, notch and recess. Further, because of the complicated shape, even if the sheet-like reinforcing member (II) cannot obtain sufficient processing dimensional accuracy due to the influence of disturbance due to the cutting of the reinforcing fibers, the resin members (IIIa) and (IIIb) are formed in the holes. By providing in, dimensional accuracy can be ensured. Since the resin members (III), (IIIa), and (IIIb) are generally formed by pouring resin into a mold, it is easy to ensure dimensional accuracy.

  The resin members (III), (IIIa), and (IIIb) may be made of the same material, but may be formed of different resins depending on the necessary functions such as, for example, providing some elasticity or conductivity. May be. Furthermore, it is formed in the entire square hole portion of the sheet-like reinforcing member (II) like the resin member (IIIa), and the cross section is concave as a pedestal portion for a logo in which each hole portion is closed and the company name is clearly indicated. It is also possible to form only the processed surface portion of the round hole portion of the sheet-like reinforcing member (II) like the resin member (IIIb), and leave the hole shape. The shape formed on the sheet-like reinforcing member (II) is not limited to the hole shape, but may be a notch shape or a concave shape, or any shape that has been post-processed. Further, the shape of the resin members (IIIa) and (IIIb) formed in the post-processed portion is not limited to the shape shown in FIG. 2, but may be any shape that matches the required shape.

  As a method for producing a sheet-like reinforcing member (II) comprising a fiber reinforced layer body including a fiber reinforced layer in which continuous fibers are arranged in a sheet shape in one direction, press molding, hand lay-up molding method, spray-up molding method, vacuum Examples thereof include a method using a thermosetting resin such as a back molding method, a pressure molding method, an autoclave molding method and a transfer molding method, and a method using a thermoplastic resin such as a press molding and a stamping molding method. In particular, vacuum back molding, press molding, transfer molding, and the like are preferably used from the viewpoint of processability and mechanical properties.

  The continuous fiber is a state in which continuous fibers having a length of 10 mm or more are arranged, and is not necessarily a continuous fiber throughout the fiber reinforced layer, and there is no particular problem even if it is divided in the middle. Examples of specific fiber forms include filaments, crosses, unidirectional drawing (UD), braids, multifilaments, and reinforcing materials in a form in which spun yarns are arranged in one direction with a drum wind or the like. From the viewpoint of process, cloth and UD are preferably used. Moreover, these strengthening forms may be used independently or may use 2 or more types of strengthening forms together.

  Specific continuous fibers include, for example, metal fibers such as aluminum fibers, brass fibers, and stainless fibers, polyacrylonitrile-based, rayon-based, lignin-based, pitch-based carbon fibers, and fibers that exhibit conductivity alone. In addition, insulating fibers such as glass fibers, organic fibers such as aramid fibers, polyparaphenylene benzoxazole (PBO) fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers, polyethylene fibers, and silicon carbide fibers Examples thereof include inorganic fibers such as silicon nitride fibers.

  These continuous fibers may be used alone or in combination of two or more. Among these, carbon fiber, particularly polyacrylonitrile-based carbon fiber is preferably used from the viewpoint of the balance of specific strength, specific rigidity, and light weight, and in particular, at a low cost.

  As the matrix of the fiber reinforced layered body, a thermoplastic resin, a thermosetting resin, a metal, or the like can be used. Examples of the thermoplastic resin include polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), liquid crystal polyester, polyethylene (PE), and polypropylene. (PP), polyolefins such as polybutylene, styrene resins, polyoxymethylene (POM), polyamide (PA), polycarbonate (PC), polymethylene methacrylate (PMMA), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), polyphenylene ether (PPE), modified PPE, thermoplastic polyimide (PI), polyamideimide (PAI), polyetherimide (PEI), polysulfone (PSU), PSU, polyethersulfone (PES), polyketone (PK), polyetherketone (PEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyarylate (PAR), polyethernitrile (PEN) , Fluoroplastics such as thermoplastic phenolic resins, phenoxy resins, polytetrafluoroethylene, and thermoplastic elastomers such as polystyrene, polyolefin, polyurethane, polyester, polyamide, polybutadiene, polyisoprene, and fluorine And these copolymers, modified products, and resins obtained by blending two or more types.

  Examples of thermosetting resins include unsaturated polyesters, vinyl esters, epoxies, phenols (resol type), urea melamines, polyimides, copolymers, modified products, and blends of at least two of these. Resin and the like. In particular, a thermosetting resin excellent in rigidity and strength of the fiber reinforced layer body, particularly a thermosetting resin mainly composed of an epoxy resin is preferable from the viewpoint of the mechanical properties of the molded product.

  Furthermore, in order to improve impact resistance, a resin obtained by adding another elastomer or a rubber component to the thermoplastic resin and the thermosetting resin may be used.

  Moreover, not only resin but metals, such as titanium, magnesium, and aluminum, may be sufficient.

  20 to 90 volume% is preferable from a viewpoint of a moldability and a dynamic characteristic, and, as for the ratio of the continuous fiber which comprises a fiber reinforcement layer body, 30 to 80 volume% is more preferable. The volume% is measured by the method described in JIS K7075.

  In addition, the composite molded article (I) of the present invention preferably has a strong bonding between the sheet-like reinforcing member (II) and the resin member (III) in order to maximize its functions. In order to join, it is preferable that the sheet-like reinforcing member (II) and the resin member (III) are joined via the thermoplastic resin composition (V). More preferably, the thermoplastic resin composition (V) is melted during the process of bonding the sheet-like reinforcing member (II) and the resin member (III), and the thermoplastic resin composition (V) is used as a bonding layer. The reinforcing member (II) and the resin member (III) can be distributed.

  Furthermore, it is preferable that the sheet-like reinforcing member (II) and the thermoplastic resin composition (V) are integrally formed in advance from the viewpoint of improving the bondability.

  Further, in order to enhance the bonding between the sheet-like reinforcing member (II) and the resin member (III), it is preferable to bring the mutual solubility parameters (SP values) of the resins close to each other, and the solubility parameter of the resin constituting the resin member (III) ( The absolute value (| δA−δB |) of the difference between the SP value) δA and the solubility parameter (SP value) δB of the resin constituting the thermoplastic resin composition (V) is preferably 0 to 1.2. More preferably, it is 0-1.0.

  The solubility parameter δ (SP value) refers to the value of the repeating unit of the polymer at 25 ° C. determined by the method of Fedors. This method is described in the following documents 1 and 2. That is, in the structural formula of the desired compound, it is determined by the following formula from the data of the evaporation energy and molar volume of atoms and atomic groups.

Solubility parameter δ (SP value) = (ΣΔei / ΣΔvi) ^1/2
In the formula, Δei and Δvi represent the evaporation energy and molar volume of an atom or atomic group, respectively. The structural formula of the compound to be determined is determined using a general structural analysis technique such as IR, NMR, and mass spectrum.
(Reference 1) RFFedors, Polym. Eng. Sci., 14 (2), 147 (1974)
(Reference 2) Shinji Mukai and Noriyuki Kaneshiro “Practical polymers for engineers”
(Kodansha, published on October 1, 1981) Pages 66-87 Examples of the resin constituting the thermoplastic resin composition (V) include polyamide resins, polyester resins, polycarbonate resins, styrene resins, and ethylene. -There are vinyl acetate copolymer (EVA) resin, urethane resin, acrylic resin, polyphenylene sulfide (PPS) resin, copolymers, modified products, and resins obtained by blending at least two of them. If necessary, an additive, a filler and the like may be included. As fillers or additives, inorganic fillers, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, coloring inhibitors, heat There are stabilizers, mold release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, foaming agents, coupling agents and the like.

  The composite molded article (I) of the present invention preferably has flame retardancy as a characteristic for its use, and flame retardancy based on UL-94 of the sheet-like reinforcing member (II) and the resin member (III) The test piece having a thickness of 0.1 to 1.6 mm is preferably V-1 or V-0. More preferably, it is V-1 or V-0 in the test piece of any thickness of 0.1-1.0 mm. Flame retardancy is evaluated by a vertical combustion test based on the UL-94 standard.

  In order to impart flame retardancy, it is preferable that the sheet-like reinforcing member (II) and the resin member (III) include at least a phosphorus-based flame retardant. As the phosphorus-based flame retardant, for example, phosphorus-containing compounds such as phosphate esters, condensed phosphate esters, and phosphaphenanthrene compounds, and red phosphorus are preferably used. Among these, red phosphorus is preferable because it has a high phosphorus atom content that serves to impart a flame retardant, so that a small amount of flame retardant should be added to obtain a sufficient flame retardant effect.

  The resin used for the resin member (III) is not particularly limited. In particular, PPS resin is used from the viewpoint of heat resistance and chemical resistance, and polycarbonate resin and styrene resin are used from the viewpoint of molded product appearance and dimensional stability. However, a polyamide resin is more preferably used from the viewpoint of the strength and impact resistance of the molded product.

  Further, in order to increase the strength and rigidity of the composite molded product (I), a resin containing reinforcing fibers may be used as the resin of the resin member (III). As reinforcing fibers, for example, metal fibers such as aluminum fibers, brass fibers, stainless steel fibers, polyacrylonitrile-based, rayon-based, lignin-based, pitch-based carbon fibers, fibers exhibiting conductivity alone such as graphite fibers, Insulating fibers such as glass fibers, organic fibers such as aramid fibers, PBO fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers, polyethylene fibers, and inorganic fibers such as silicon carbide fibers and silicon nitride fibers It can be illustrated.

  These continuous fibers may be used alone or in combination of two or more. Among these, carbon fiber, particularly polyacrylonitrile-based carbon fiber is preferably used from the viewpoint of the balance of specific strength, specific rigidity, and light weight, and in particular, at a low cost.

  Furthermore, the resin constituting the resin member (III) may contain other fillers and additives within a range that does not impair the object of the present invention, depending on required characteristics. For example, inorganic fillers, non-phosphorous flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorants, anti-coloring agents, heat stabilizers , Mold release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, antifoaming agents, coupling agents and the like.

  FIG. 4 is an exploded perspective view of the composite molded article (I) illustrated in FIG.

  In FIG. 4, the composite molded product (I) of the present invention is a sheet-like reinforcing member (II) having four fiber reinforced layers in which continuous fibers are arranged in a sheet shape in one direction. The reason is that the fiber reinforced layer made of continuous fibers is an anisotropic material that has different mechanical properties depending on the direction, which is strong in the fiber direction and weak in the direction other than the fiber direction, unlike metal. And the fiber reinforced layer made of carbon fiber has a bending elastic modulus in the direction perpendicular to the fiber direction of about 1/5 with respect to the bending elastic modulus in the fiber direction.) Then, even if it is satisfactory in terms of strength, it may happen that it cannot be satisfied in other directions. For this reason, it is necessary to arrange the fiber direction of a fiber reinforcement layer appropriately in the direction where strength is required.

  However, the fiber reinforced layer is generally molded by pressurization and heating using resin or metal as a continuous fiber matrix, so even if the fiber direction is determined in the dark clouds, molding shrinkage in each direction There arises a problem that warping or twisting occurs in the fiber reinforced layer due to a difference in rate or tensile strength. For example, when the reinforcing fibers are carbon fibers and the matrix resin is an epoxy resin, the molding shrinkage in the fiber direction is extremely small, about 1/50 compared with the direction orthogonal to the fiber direction. For this reason, in order to obtain a sheet-shaped reinforcing member (II) having low anisotropy and less warping or twisting during molding and having high dimensional stability, the fiber orientation is based on the neutral layer, and is vertically symmetrical It is preferable to dispose the fiber reinforced layer as described above. Here, the neutral layer is a central layer with respect to the stacking direction. Specifically, when the number of stacked layers is (2 × n) layers (n is a positive integer), the layers between the nth layer and the (n + 1) th layer are shown, and the number of stacked layers is (2 × n−1). In the case of a layer (n is a positive integer), it is the nth layer. The number of fiber reinforced layers is four here, but it is not particularly limited. When the thickness is desired to be increased, the number of layers is increased. On the other hand, when the thickness is desired to be decreased, the required thickness and required strength are reduced. It is preferable to select appropriately according to the above. However, in order to reduce the above-described anisotropy and obtain a sheet-like reinforcing member (II) with a more balanced stiffness, it is preferable to laminate a plurality of fiber reinforced layers.

  In particular, in the case of a notebook computer case, in order to protect the internal parts of the case from external force, it is required to bend even when external force is applied, that is, to increase bending rigidity. It is preferable from the viewpoint of improving bending rigidity that the reinforcing fiber (II) is arranged so that the direction of the reinforcing fiber in the outermost layer is substantially the short side direction (1a) of the sheet-like reinforcing member (II). For example, when the rectangular carbon fiber reinforced sheet-shaped reinforcing member (II) having a ratio of the long side to the short side of 2 is manufactured in a three-layer configuration, the direction of the first layer of reinforcing fibers is the short side direction (1a ), The direction of the second layer reinforcing fiber is the long side direction (1b), the direction of the third layer reinforcing fiber is the short side direction (1a), and the direction of the first layer reinforcing fiber is In the long side direction (1b), the direction of the second layer reinforcing fiber is shorter than the direction of the short side (1a), and the direction of the third layer reinforcing fiber is longer than the direction of the long side (1b). When applied, the deflection is about ½. In order to further reduce the weight, it is also possible to use a sheet-shaped reinforcing member (II) having a sandwich structure in which a lightweight resin member, more preferably a foamed resin member, is sandwiched between fiber reinforced layers. In terms of material mechanics, the surface stiffness is a fiber reinforced layer and the neutral layer because the stiffness of the layer close to the surface layer of the sheet-like reinforcing member (II) is significantly greater than the stiffness of the layer near the neutral layer described above. This is because the rigidity of the sheet-like reinforcing member (II) can be ensured while the weight is reduced by constituting the lightweight resin member.

  FIG. 5 is a schematic cross-sectional view of an injection mold according to an embodiment of the present invention.

  First, a sheet-shaped reinforcing member (II) having at least one shape selected from the group consisting of (a) hole, (b) notch, and (c) recess is produced in advance, and this member is illustrated in FIG. After being set in the mold shown in FIG. 5, the mold is clamped, and the resin member (IIIa) is formed on at least a part of the processed surface of the hole, notch, and recess by injection molding the resin member (III). (IIIb) is formed to produce a composite molded article (I).

  The mold illustrated in FIG. 5 includes a female mold 2 and a male mold 3. The male mold 3 includes a gate 4 for injection molding a resin member (III), and a resin in a square hole portion. In order to fix the gate 4a for injection molding of the member (IIIa), the gate for injection molding of the resin member (IIIb) in a round hole (not shown) and the sheet-like reinforcing member (II) in the male mold 3 The adsorption hole 5 is provided. In addition, when the shape of the sheet-like reinforcing member (II) itself has a hole or an uneven shape, a positioning member or a sheet-like reinforcing member (not shown) that can be fitted into the male mold 3 with the hole or the uneven portion. The sheet-shaped reinforcing member (II) can be fixed in the male mold 3 by providing in advance a positioning member 6 that can fix at least a part of the outer periphery of the member (II). Furthermore, an extrusion pin 7 is also provided for injection molding after the resin member (III) is clamped and taking out the composite molded product (I) from the mold.

  Examples of applications of the composite molded product (I) include personal computers, displays, OA equipment, mobile phones, personal digital assistants, facsimile machines, compact discs, portable MDs, portable radio cassettes, PDAs (electronic notebooks, etc.) ), Video cameras, digital still cameras, optical equipment, audio equipment, air conditioners, lighting equipment, entertainment equipment, toy equipment, other electrical appliances such as home appliances, and internal components such as trays and chassis, cases and mechanisms thereof Examples include parts, electric parts for automobiles and aircraft, and internal parts.

  In particular, the composite molded product (I) of the present invention is suitable for electrical and electronic equipment casings and external members by taking advantage of its excellent lightness, high strength and high rigidity, high designability, and high scratch resistance. Furthermore, it is suitable as a casing for a notebook personal computer or a portable information terminal that requires a thin and wide projection area.

  The present invention will be described more specifically with reference to the following examples. However, the following examples are not intended to limit the present invention in any way, and modifications within the scope of the present invention may be made without departing from the spirit of the present invention. It is a range.

(Example 1)
As the sheet-like reinforcing member (II), carbon fiber unidirectional prepreg (UD PP) P3052S (manufactured by Toray Industries, Inc., carbon fiber T700S (strength 4900 MPa, elastic modulus 230 GPa), carbon fiber content 67% by weight, carbon fiber basis weight 125 g / m ² , base resin: epoxy resin # 2500), and the outermost layer as a thermoplastic resin composition (V) is a polyamide layer CM4000 (manufactured by Toray Industries, Ltd., terpolymer polyamide resin, polyamide 6/66 / 610, melting point 150 ° C .; one layer of solubility parameter δ (SP value) 13.3) is press-molded (die temperature 150 ° C., pressure 1.5 MPa, curing time 30 minutes, target thickness after molding 0. 5mm), and after processing this into an external size of about 300mm x 230mm, 40mm x 30mm square holes in the sheet-like reinforcing member (II) After setting one place and one φ10mm round hole part in an injection mold as shown in FIG. 5 and performing mold clamping, long fiber pellets TLP1146S (Toray ( Co., Ltd. carbon fiber content 20%, base resin: polyamide 6; solubility parameter δ (SP value) 13.6, resin flow direction molding shrinkage: 0.1%) is injection molded to form a composite molded product (I) As a result, the gap S at the joint between the sheet-like reinforcing member (II) and the resin member (III) was 5 μm at the maximum, and the surface height difference D was 10 μm at the maximum. Then, when a photocurable (ultraviolet curable) paint (M-40 manufactured by Origin Electric Co., Ltd.) was formed as the hard layer (IV), the appearance design was good and the pencil hardness of the hard layer surface was 2H. Even if scratched with a nail, it was hardly scratched.

(Example 2)
As the sheet-like reinforcing member (II), carbon fiber unidirectional prepreg (UD PP) P3052S (Toray Industries, Inc. carbon fiber T700S (strength 4900 MPa, elastic modulus 230 GPa), carbon fiber content 67% by weight, carbon fiber basis weight 200 g / m ² , base resin: epoxy resin # 2500), and then a polypropylene foam material “Efcel” (registered trademark) RC2010 (manufactured by Furukawa Electric Co., Ltd .; thickness 1.0 mm) is laminated, and carbon Fiber unidirectional prepreg (UD PP) P3052S (manufactured by Toray Industries, Inc., carbon fiber T700S (strength 4900 MPa, elastic modulus 230 GPa), carbon fiber content 67 wt%, carbon fiber basis weight 200 g / m ² , base resin: epoxy resin # 2500 ) And a polyamide layer CM4 as the thermoplastic resin composition (V) in the outermost layer. 000 (manufactured by Toray Industries, Inc., ternary copolymer polyamide resin, polyamide 6/66/610, melting point 150 ° C .; solubility parameter δ (SP value) 13.3) is laminated by pressing (mold temperature 145 C., pressure 1.5 MPa, curing time 30 minutes, target thickness after molding 1.5 mm), and after processing this into a size of 300 mm × 230 mm, it is 40 mm × 30 mm in the sheet-like reinforcing member (II) After setting one corner hole portion and one φ10 mm round hole portion in an injection mold as shown in FIG. 5 and performing mold clamping, long fiber pellets TLP1146S as a resin member (III) (Toray Industries, Inc., carbon fiber content 20%, base resin: polyamide 6; solubility parameter δ (SP value) 13.6, resin flow direction molding shrinkage: 0.1%) was injection molded to form a composite molded product. Was producing I), the gap S of the joint portion of the sheet-like reinforcing member (II) and the resin member (III) is 5μm at most, surface height difference D was 10μm in maximum. Then, when a photocurable (ultraviolet curable) paint (M-40 manufactured by Origin Electric Co., Ltd.) was formed as the hard layer (IV), the appearance design was good and the pencil hardness of the hard layer surface was 2H. Even if scratched with a nail, it was hardly scratched.

(Example 3)
As the sheet-like reinforcing member (II), carbon fiber unidirectional prepreg (UD PP) P3052S (manufactured by Toray Industries, Inc., carbon fiber T700S (strength 4900 MPa, elastic modulus 230 GPa), carbon fiber content 67% by weight, carbon fiber basis weight 125 g / m ² , base resin: epoxy resin # 2500), and the outermost layer as a thermoplastic resin composition (V) is a polyamide layer CM4000 (manufactured by Toray Industries, Ltd., terpolymer polyamide resin, polyamide 6/66 / 610, melting point 150 ° C .; one layer of solubility parameter δ (SP value) 13.3) is press-molded (die temperature 150 ° C., pressure 1.5 MPa, curing time 30 minutes, target thickness after molding 0. 5mm), and after processing this into an external size of about 300mm x 230mm, 40mm x 30mm square holes in the sheet-like reinforcing member (II) After setting one place and one φ10mm round hole part in an injection mold as shown in FIG. 5 and performing mold clamping, long fiber pellets TLP1146S (Toray ( Co., Ltd. carbon fiber content 20%, base resin: polyamide 6; solubility parameter δ (SP value) 13.6, resin flow direction molding shrinkage: 0.1%) is injection molded to form a composite molded product (I) As a result, the gap S at the joint between the sheet-like reinforcing member (II) and the resin member (III) was 5 μm at the maximum, and the surface height difference D was 10 μm at the maximum. Then, after applying and drying acrylic urethane paint (Origin Plate-Z-NY, manufactured by Origin Electric Co., Ltd.), as a hard layer (IV), photocurable (ultraviolet curable) paint (Made by Origin Electric Co., Ltd., M) When -40) was formed, the appearance design was also good, the pencil hardness of the hard layer surface was 2H, and it was hardly scratched even when scratched with a nail.

Example 4
As the sheet-like reinforcing member (II), carbon fiber unidirectional prepreg (UD PP) P3052S (manufactured by Toray Industries, Inc., carbon fiber T700S (strength 4900 MPa, elastic modulus 230 GPa), carbon fiber content 67% by weight, carbon fiber basis weight 125 g / 4 layers of m ² , base resin: epoxy resin # 2500) are manufactured by press molding (mold temperature 150 ° C., pressure 1.5 MPa, curing time 30 minutes, target thickness after molding 0.5 mm). Then, after processing this into an outer size of about 300 mm × 230 mm, a sheet-like reinforcing member (II) having one square hole portion of 40 mm × 30 mm and one round hole portion of φ10 mm was manufactured. Resin members (III), (IIIa) and (IIIb) are long fiber pellets TLP1146S (carbon fiber content 20%, manufactured by Toray Industries, Inc., base resin: polyamide 6; solubility parameter δ (SP value) 13.6, resin After the flow direction molding shrinkage: 0.1%) is manufactured by injection molding, the sheet-like reinforcing member (II) and the resin members (III), (IIIa), (IIIb) are integrated with an adhesive. Since the gap S at the joint between the sheet-like reinforcing member (II) and the resin member (III) is 70 μm at the maximum and the surface height difference D is 100 μm at the maximum, the unsaturated polyester is formed on the surface on which the hard layer (IV) is formed. After applying and drying putty (LP960 made by Solar Co., Ltd.), sanding with sandpaper (# 1000) and joining the sheet-like reinforcing member (II) and resin members (III), (IIIa), (IIIb) Gap S and surface height D is set to 50 μm or less, acrylic / urethane paint (Origin Plate-Z-NY, manufactured by Origin Electric Co., Ltd.) is applied and dried, and then the hard layer (IV) is used as a photocurable (ultraviolet curable) paint (origin) When M-40 manufactured by Denki Co., Ltd. was formed, the appearance design was also good, the pencil hardness of the hard layer surface was 2H, and scars were hardly scratched even when scratched with a nail.

(Comparative Example 1)
A composite molded article (I) was produced in the same manner as in Example 1 except that the hard layer (IV) was not formed. The surface pencil hardness was HB, and it was easily scratched by scratching with a nail. The sex could not be maintained.

(Comparative Example 2)
As the sheet-like reinforcing member (II), carbon fiber unidirectional prepreg (UD PP) P3052S (manufactured by Toray Industries, Inc., carbon fiber T700S (strength 4900 MPa, elastic modulus 230 GPa), carbon fiber content 67% by weight, carbon fiber basis weight 125 g / 4 layers of m ² , base resin: epoxy resin # 2500) are manufactured by press molding (mold temperature 150 ° C., pressure 1.5 MPa, curing time 30 minutes, target thickness after molding 0.5 mm). Then, after processing this into an outer size of about 300 mm × 230 mm, a sheet-like reinforcing member (II) having one square hole portion of 40 mm × 30 mm and one round hole portion of φ10 mm was manufactured. Resin members (III), (IIIa) and (IIIb) are long fiber pellets TLP1146S (carbon fiber content 20%, manufactured by Toray Industries, Inc., base resin: polyamide 6; solubility parameter δ (SP value) 13.6, resin After the flow direction molding shrinkage: 0.1%) is manufactured by injection molding, the sheet-like reinforcing member (II) and the resin members (III), (IIIa), (IIIb) are integrated with an adhesive. The gap S at the joint between the sheet-like reinforcing member (II) and the resin member (III) was 70 μm at the maximum, and the surface height difference D was 100 μm at the maximum. Then, after applying and drying an acrylic / urethane paint (Origin Plate-Z-NY, manufactured by Origin Electric Co., Ltd.), the hard layer (IV) was used as a photocurable (ultraviolet curable) paint (M-made by Origin Electric Co., Ltd.). 40) was formed, the pencil hardness of the hard surface layer was 2H, but the appearance of the streaks at the joint between the sheet-like reinforcing member (II) and the resin member (III) was poor, which was insufficient as a product. Met.

  From Examples 1 to 4 and Comparative Examples 1 and 2, the following became clear.

  The composite molded products (I) of Examples 1 to 4 are lightweight, highly rigid, and highly rigid, satisfy extremely high design properties, have high scratch resistance, and are suitable as a housing for electric / electronic devices. there were.

  On the other hand, in the composite molded product (I) of Comparative Example 1, the surface was easily damaged, and high designability could not be maintained. In Comparative Example 2, streaks were seen at the joint between the sheet-like reinforcing member (II) and the resin member (III), which was insufficient as a product.

  The composite molded product (I) of the present invention is not limited to use in electrical and electronic equipment casings such as notebook computers and portable terminals, but takes advantage of its excellent lightness, high strength, high rigidity, high designability, and safety. Although it can be applied to automotive parts such as spoilers, medical parts such as stretchers, and musical instrument carrying cases, the application range is not limited to these.

1 is a perspective view of a composite molded product (I) according to an embodiment of the present invention. It is AA sectional drawing of the composite molded product (I) which concerns on one Example of this invention. It is B section detail drawing of the composite molded product (I) which concerns on one Example of this invention. It is a disassembled perspective view of the composite molded product (I) which concerns on one Example of this invention. It is a general | schematic cross-sectional view of the injection mold for shape | molding the composite molded product (I) based on one Example of this invention.

Explanation of symbols

I: Composite molded product
II: Sheet-like reinforcing member
III: Resin member
IIIa: Resin member (square hole)
IIIb: Resin member (round hole)
IV: Hard layer
V: Thermoplastic resin plastic 1a: Fiber direction (short side direction) of fiber reinforced layer
1b: Fiber direction of the fiber reinforced layer (long side direction)
2: Female type 3: Male type 4: Gate 4a: Gate (for forming a square hole)
5: Hole for suction 6: Positioning member 7: Extrusion pin S: Gap between joints D: Surface height difference (step) of joints

Claims (15)

In the composite molded product (I) including the sheet-like reinforcing member (II) and the resin member (III), a pencil is provided on at least a part of the surface extending over the joint portion between the sheet-like reinforcing member (II) and the resin member (III). The hard layer (IV) having a hardness of 2H or more is formed, and the gap S at the joint between the sheet-like reinforcing member (II) and the resin member (III) on which the hard layer (IV) is formed is 0 to 0 A composite molded article (I) having a surface height difference D of 0 to 50 μm and a thickness of 50 μm. The composite molded article (I) according to claim 1, wherein the resin member (III) is formed by injection molding and has a molding shrinkage in the resin flow direction of 0 to 0.5%. The composite molded article (I) according to claim 1 or 2, wherein the sheet-like reinforcing member (II) is a fiber-reinforced layer body including a fiber-reinforced layer in which continuous fibers are arranged in a sheet shape in one direction. The composite molded article (I) according to claim 3, wherein the continuous fibers of the fiber reinforced layer contain at least carbon fibers. The composite molded article (I) according to any one of claims 1 to 4, wherein the sheet-like reinforcing member (II) and the resin member (III) are joined via the thermoplastic resin composition (V). Absolute value (| δA-δB |) of the difference between the solubility parameter (SP value) δA of the resin constituting the resin member (III) and the solubility parameter (SP value) δB of the resin constituting the thermoplastic resin composition (V) The composite molded article (I) according to claim 5, wherein is from 0 to 1.2. The flame retardancy based on UL-94 of the sheet-like reinforcing member (II) and the resin member (III) is V-1 or V-0 in a test piece having a thickness of 0.1 to 1.6 mm. The composite molded article (I) according to any one of 1 to 6. The composite molded article (I) according to claim 7, wherein the sheet-like reinforcing member (II) and the resin member (III) contain at least a phosphorus-based flame retardant. The composite molded article (I) according to any one of claims 1 to 8, wherein the sheet-like reinforcing member (II) contains a matrix resin mainly composed of an epoxy resin. The composite molded article (I) according to any one of claims 1 to 9, wherein the resin member (III) contains reinforcing fibers. The composite molded article (I) according to claim 10, wherein the reinforcing fibers include at least carbon fibers. The composite molded article (I) according to any one of claims 1 to 11, wherein the hard layer (IV) is formed of any one of a photocurable resin, a catalyst curable resin, and an electron beam curable resin. The composite molded article (I) according to any one of claims 1 to 12, which is a casing for electronic equipment. The composite molded article (I) according to claim 13, which is a notebook personal computer casing. The composite molded article (I) according to claim 13, which is a casing for a mobile phone.

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