Integrated molded body and electronic apparatus housing

Abstract

Provided is an integrated molded body having excellent heat conduction, lightness, and rigidity in which a laminate having excellent heat conduction, lightness, and rigidity is integrated with another member.　The present invention provides an integrated molded body in which a structure comprising a thermoplastic resin and reinforcing fibers is disposed on an outer peripheral part of a laminate in which at least prepregs comprising continuous carbon fibers and a resin are laminated, wherein a first prepreg constituting an outermost layer of the laminate has a heat conductivity λ1A of 100 [W / (m·K)] or more and 800 [W / (m·K)] or less in a fiber direction of the continuous carbon fibers. The integrated molded body is preferably used in an electronic apparatus housing.

Description

Integrated molded body and electronic device housing

[0001] The present invention relates to an integrated molded body and an electronic device housing having excellent properties of light weight, rigidity, and thermal conductivity, including a laminate that uses continuous carbon fiber with a specific thermal conductivity and has excellent light weight, thin wall properties, and rigidity.

[0002] Currently, there is an increasing demand for greater portability and performance in electrical and electronic devices such as personal computers, office automation equipment, audiovisual equipment, mobile phones, telephones, facsimiles, home appliances, toys, etc. To meet these demands, the components that make up the devices, especially the housings, must be lightweight and compact, as well as have heat dissipation properties that allow the heat generated by the internal components to be efficiently released outside the product, protecting the internal components from external heat.

[0003] Patent Document 1 discloses a structure in which a material with high thermal conductivity, such as a metal, is laminated inside a sandwich structure to improve heat dissipation, while Patent Document 2 discloses a structure in which a material with high thermal conductivity is used for the laminate.

[0004] Patent Document 2 discloses a thermally conductive molded body in which a first member made of a resin composition reinforced with a continuous reinforcing fiber group and a second member are integrated together, ensuring light weight and mechanical properties, and the reinforcing fibers used in the first member and the second member both have high thermal conductivity, thereby maintaining the properties of the thermally conductive molded body and providing a strong integration between the first member and the second member so that the bonding strength is excellent. Patent Document 2 also discloses a bonding method for such a thermally conductive molded body that can achieve both moldability and productivity for complex shapes.

[0005] International Publication No. 2016 / 002457 Patent No. 4973364

[0006] However, in Patent Document 1, it is necessary to laminate and integrate base materials of different materials, which makes it difficult to control the adhesion of each layer and warpage, resulting in problems with formability.In addition, in Patent Document 2, the integrated molded body itself has high thermal conductivity, so when used in electronic devices, there is a problem that heat from the outside is also transferred to the inside of the product.

[0007] An object of the present invention is to provide a laminate that is superior in thermal conductivity, light weight, and rigidity compared to the conventional techniques. Another object of the present invention is to provide an integrated molded body and an electronic device housing that are superior in thermal conductivity, light weight, and rigidity by integrating the laminate with other members.

[0008] In order to solve the above problems, the integrally molded body according to the present invention employs the following configuration.

[0009] (1) An integrally molded body in which a structure made of thermoplastic resin and reinforcing fiber is arranged on the outer periphery of a laminate in which at least prepregs made of continuous carbon fiber and resin are laminated, and the thermal conductivity λ1A in the fiber direction of the continuous carbon fiber of a first prepreg constituting the outermost layer of the laminate is 100 [W / (m K)] or more and 800 [W / (m K)] or less.

[0010] (2) The integrally molded body according to (1), wherein the laminate is a sandwich structure composed of a core layer and a prepreg, the prepreg being disposed on both sides of the core layer.

[0011] (3) The integrally molded body according to (2), wherein the core layer is a foamed molded body made of a foam resin or a porous substrate made of discontinuous fibers and a thermoplastic resin.

[0012] (4) An integrally molded body according to any one of claims 1 to 3, which satisfies the following (i) and / or (ii):

[0013] (i) The laminate is a sandwich structure composed of a core layer and a prepreg, with the prepreg disposed on both sides of the core layer, and satisfies the following (i-1) or (i-2):

[0014] (i-1) The core layer is a foamed molded body made of a foamed resin, and the ratio λ21 / λ1A of the thermal conductivity λ21 to the thermal conductivity λ1A of the foamed molded body is greater than 0 and not greater than 0.05.

[0015] (i-2) The core layer is a porous substrate made of discontinuous fibers and a thermoplastic resin, the discontinuous fibers constituting the porous substrate are carbon fibers, and the ratio λ22 / λ1A of the thermal conductivity λ1A to the thermal conductivity λ22 in the fiber direction of the discontinuous fibers is greater than 0 and less than or equal to 1.0. (ii) The prepregs constituting the laminate include heterogeneous carbon fiber prepregs in which the continuous carbon fibers constituting the prepregs other than the first prepreg 21 are made of a different type of carbon fiber than the continuous carbon fibers constituting the first prepreg 21, and the ratio λ1B / λ1A of the thermal conductivity λ1A to the thermal conductivity λ1B of the carbon fiber with the lowest thermal conductivity among the heterogeneous carbon fiber prepregs is greater than 0 and less than or equal to 1.0.

[0016] (5) The density of the continuous carbon fiber constituting the first prepreg is 2.0 g / cm ３ ~2.5g / cm ３ The integrally molded body according to any one of (1) to (4),

[0017] (6) An integrally molded body according to any one of (1) to (5), wherein a continuous fiber woven fabric substrate is disposed on the outer side of at least one of the outermost layers of the laminate to form a design surface.

[0018] (7) The integrally molded body according to any one of (1) to (6), wherein a thermoplastic resin substrate is provided at least partially between the laminate and the structure.

[0019] (8) The integrally molded body according to any one of (1) to (7), which is used as a housing for an electronic device.

[0020] (9) An electronic device housing comprising the integrally molded body according to any one of (1) to (8).

[0021] According to the present invention, an integrated molded body and an electronic housing having excellent thermal conductivity, light weight, and rigidity can be obtained. The integrated molded body of the present invention can suppress the heat conduction of heat received from the outside or the inside to the opposite surface and can diffuse the heat in an in-plane direction, thereby providing an integrated molded body and an electronic housing that, as an electronic device housing, prevents the influence of heat from the outside and localized temperature increases on the design surface due to heat generated from the inside.

[0022] FIG. 1 is a schematic perspective view of an integrally molded body 10 according to one embodiment of the present invention. It is a schematic cross-sectional view in the thickness direction of an integrally molded body 10 in which a resin member is bonded to the outer periphery of a laminate 20 composed of a first prepreg 21 and a second prepreg, as seen along line A-A' in FIG. 1. It is a schematic cross-sectional view in the thickness direction of an integrally molded body 10 in which a core layer composed of a foam molded body 40 is provided and a resin member is bonded to the outer periphery of the laminate 20. It is a schematic cross-sectional view in the thickness direction of an integrally molded body 10 in which a continuous fiber woven fabric substrate is arranged further outside the laminate 20 composed of the first prepreg 21 and the second prepreg to form a design surface. It is a schematic cross-sectional view in the thickness direction of an integrally molded body 10 in which a resin member is bonded to the outer periphery of a laminate 20 provided with a thermoplastic resin layer. It is a schematic cross-sectional view in the thickness direction of an integrally molded body 10 in which a resin member is bonded to the outer periphery of a core layer composed of a porous substrate 50 and a laminate 20 with a thickness difference. It is a schematic cross-sectional view in the thickness direction of an integrally molded body 10 in which a resin member is bonded to the outer periphery using a resin frame 80.

[0023] Hereinafter, embodiments will be described with reference to the drawings, but the present invention is not limited to the drawings and examples.

[0024] The integrally molded body 10 according to the present invention is an integrally molded body 10 in which a structure 30 made of thermoplastic resin and reinforcing fibers is disposed on the outer periphery of a laminate 20 made of at least prepregs made of continuous carbon fiber and resin. The thermal conductivity λ1A in the fiber direction of the continuous carbon fiber used in the first prepreg 21 constituting the outermost layer of the laminate 20 is 100 [W / (m·K)] or more and 800 [W / (m·K)] or less. Here, the "laminate 20 made of at least prepregs" refers to a laminate containing prepregs within the lamination units, and may also contain lamination units other than prepregs. Furthermore, the prepreg may contain other components in addition to the continuous carbon fiber and resin. Note that the term "resin" here refers to a matrix resin, and may refer to either a resin alone or a resin composition. Similarly, the structure 30 may contain other components in addition to the thermoplastic resin and reinforcing fibers.

[0025] The integrally molded body 10 according to this embodiment has a structure in which a structure 30 is bonded to the outer peripheral edge of a laminate 20, as shown in Fig. 2. The laminate 20 may have a structure in which a core layer is provided in the internal layer, as shown in Fig. 3 (described later), or a structure in which continuous fiber woven fibers are arranged on the design surface, as shown in Fig. 4 (described later), depending on the application and required performance of the integrally molded body 10. Fig. 2 is a schematic cross-sectional view of the integrally molded body 10 in the thickness direction taken along line A-A' in Fig. 1, but is shown upside down compared to Fig. 1. Similarly, Figs. 3 to 7 are also shown upside down compared to Fig. 1.

[0026] Here, continuous fibers and discontinuous fibers are defined. Continuous fibers refer to reinforcing fibers contained in the integrally molded body 10 that are arranged substantially continuously over the entire length or width of the integrally molded body 10. On the other hand, discontinuous fibers refer to reinforcing fibers that are arranged intermittently. Generally, fibers contained in unidirectional fiber-reinforced resins in which reinforcing fibers aligned in one direction are impregnated with resin are considered continuous fibers, and fibers contained in SMC (sheet molding compound) substrates used in press molding and pellet materials containing reinforcing fibers, such as those used in injection molding, are considered discontinuous fibers. Continuous fibers refer to reinforcing fibers that are continuous in at least one direction over a length of 100 mm or more.

[0027] From the viewpoint of weight reduction, the continuous carbon fibers are preferably carbon fibers (including graphite fibers) that are excellent in specific strength and specific rigidity, such as polyacrylonitrile (PAN)-based carbon fibers, rayon-based carbon fibers, lignin-based carbon fibers, and pitch-based carbon fibers. Among these, in the present invention, it is preferable to use pitch-based carbon fibers that are excellent in thermal conductivity in at least one layer of the laminate 20, and it is also preferable to use polyacrylonitrile (PAN)-based carbon fibers in combination from the viewpoint of cost.

[0028] In the present invention, it is important that the thermal conductivity λ1A in the fiber direction of the continuous carbon fibers of the first prepreg 21 constituting the outermost layer of the laminate 20 is 100 W / (m·K) or more and 800 W / (m·K) or less from the viewpoint of the heat dissipation of the integrally molded body 10. If it is less than 100 W / (m·K), the generated heat cannot be dispersed, and heat may accumulate inside the product, causing internal damage. Preferably, it is 150 W / (m·K) or more and 800 W / (m·K) or less, and more preferably, it is 300 W / (m·K) or more and 800 W / (m·K) or less from the viewpoint of the balance between productivity and thermal conductivity. The thermal conductivity in the fiber direction of the carbon fibers can be measured by the test described in JIS A1412-2 (1999).

[0029] By using such continuous carbon fibers, a laminate having excellent thermal conductivity, light weight, and rigidity can be obtained.

[0030] Furthermore, the tensile modulus of the continuous carbon fiber is preferably in the range of 200 to 1000 GPa from the viewpoint of the rigidity of the laminate 20, and more preferably in the range of 280 to 900 GPa from the viewpoint of the handleability of the prepreg. If the tensile modulus of the carbon fiber is less than 200 GPa, the rigidity of the sandwich structure may be poor, while if it is greater than 1000 GPa, the crystallinity of the carbon fiber must be increased, making it difficult to manufacture the carbon fiber. A tensile modulus of the carbon fiber within the above range is preferable in terms of further improving the rigidity of the sandwich structure and improving the manufacturability of the carbon fiber. The tensile modulus of the carbon fiber can be measured by the strand tensile test described in JIS R7301 (1986).

[0031] In particular, the tensile modulus of the continuous carbon fibers used in the prepreg constituting the outermost layer is preferably 400 to 1000 GPa, more preferably 500 to 900 GPa, from the viewpoint of the rigidity of the laminate 20 .

[0032] The density of the carbon fiber used for continuous carbon fiber is 1.6 g / cm in the case of polyacrylonitrile (PAN)-based carbon fiber. ３ 2.0g / cm or more ３ From the viewpoint of improving rigidity, 1.8 g / cm ３2.0g / cm or more ３ In the case of pitch-based carbon fiber, 2.0 g / cm ３ 2.5g / cm or more ３ From the viewpoint of cost, 2.0 g / cm ３ 2.3g / cm or more ３ It is preferable that:

[0033] Among these, the density of the continuous carbon fiber used in the first prepreg 21 constituting the outermost layer of the laminate 20 is 2.0 g / cm ３ ~2.5g / cm ３ From the viewpoint of cost, it is preferable that the density is 2.0 g / cm ３ 2.3g / cm or more ３ It is more preferable that the density of the carbon fiber is not more than 100%. The density of the carbon fiber can be measured by the test described in JIS R7603-A (1999).

[0034] The resin used for the prepreg is not particularly limited, and a thermoplastic resin or a thermosetting resin can be used. In the case of a thermoplastic resin, for example, the same type of resin as the thermoplastic resin used in the core layer described below can be used. As the thermosetting resin, unsaturated polyester resin, vinyl ester resin, epoxy resin, phenol (resol type) resin, urea-melamine resin, polyimide resin, maleimide resin, benzoxazine resin, and the like can be preferably used. A resin blend of two or more of these may also be used. Among these, epoxy resin is particularly preferred from the viewpoint of the mechanical properties and heat resistance of the molded product. In order to exhibit its excellent mechanical properties, epoxy resin is preferably included as the main component of the resin used. When an epoxy resin is combined with other components to form a resin composition, it is preferably included in an amount of 30% by mass or more per resin composition.

[0035] The weight fiber content of the continuous carbon fibers contained in the prepreg is preferably 30 to 70% by mass from the viewpoint of moldability and buckling characteristics of the laminate 20. If it is less than 30% by mass, it may be difficult for the laminate 20 to exhibit buckling strength. If it exceeds 70% by mass, there may be a shortage of resin, which may impair the design after molding. It is preferably 62 to 68% by mass.

[0036] The thickness of the prepreg is preferably 0.05 to 1.00 mm from the viewpoint of the thickness of the laminate 20. More preferably, it is 0.05 to 0.20 mm from the viewpoint of the degree of freedom in design. If the thickness of the prepreg is thinner than 0.05 mm, it may be difficult to handle.

[0037] In the present invention, from the viewpoint of reducing the weight and increasing the rigidity of the laminate 20, it is preferable that the laminate 20 has a sandwich structure in which prepregs are arranged on both sides of a core layer as shown in FIG.

[0038] By providing such a core layer, a lighter and more rigid laminate can be obtained.

[0039] The core layer is preferably a foamed molded body 40 or a porous substrate 50. The foamed molded body 40 is preferably made of a foam resin, and the porous substrate 50 is preferably a substrate made of discontinuous fibers and a thermoplastic resin.

[0040] When a foam molded body 40 is used for the core layer, the thermosetting resins and thermoplastic resins described above can be used as the resin type. Among these, polyurethane resin, phenolic resin, melamine resin, acrylic resin, polyethylene resin, polypropylene resin, polyvinyl chloride resin, polystyrene resin, acrylonitrile-butadiene-styrene (ABS) resin, polyetherimide resin, and polymethacrylimide resin are preferably used. Specifically, to ensure light weight, it is preferable to use a resin with a lower apparent density than prepreg, and polyurethane resin, acrylic resin, polyethylene resin, polypropylene resin, polyetherimide resin, and polymethacrylimide resin are particularly preferred. The resin types listed as examples may contain impact resistance improvers such as elastomers or rubber components, other fillers, and additives, as long as the object of the present invention is not impaired. Examples of these include inorganic fillers, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration dampers, antibacterial agents, insect repellents, deodorizing agents, color prevention agents, heat stabilizers, release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, foam control agents, and coupling agents.

[0041] In the present invention, when a foamed molded article 40 is used for the core layer, the larger the ratio of thermal conductivity λ21 / λ1A to the prepreg, the greater the heat conduction in the thickness direction and the less heat conduction in the in-plane direction. Therefore, the smaller the value of λ21 / λ1A, the greater the heat conduction in the in-plane direction, making it less susceptible to localized heating when used as an electronic device housing. For this reason, the value of λ21 / λ1A is preferably greater than 0 and less than 0.05 from the perspective of light weight, rigidity, and heat dissipation, and more preferably greater than 0 and less than 0.01 from the perspective of heat dissipation.

[0042] The thermal conductivity λ21 [W / (m·K)] of the foam molded body 40 used in the core layer is preferably greater than 0 W / (m·K) and less than or equal to 10 W / (m·K). If it exceeds 10 W / (m·K), the generated heat will be transferred to the inside / outside, potentially affecting internal components or causing burns during use. Preferably, it is greater than 0 W / (m·K) and less than or equal to 5 W / (m·K), and more preferably greater than 0 W / (m·K) and less than or equal to 1 W / (m·K). The thermal conductivity of the foam molded body 40 can be measured using the test described in JIS H7903 (2008).

[0043] Furthermore, the porous substrate 50 used as the core layer is preferably one in which a precursor composed of discontinuous fibers and a thermoplastic resin is expanded in the thickness direction by springback due to heating, thereby forming voids. A molded body containing the discontinuous fibers and thermoplastic resin that constitute the core layer is heated and pressurized above the softening point or melting point of the resin, and then the pressure is released. The core layer is expanded by the restoring force, or so-called springback, that occurs when the residual stress of the discontinuous fibers is released, thereby forming the desired voids within the core layer. During this restoration process, the restoration action can be suppressed in some regions by a certain pressure means, etc., to keep the void ratio low.

[0044] As the carbon fiber used in the core layer, carbon fibers (including graphite fibers) such as polyacrylonitrile (PAN)-based carbon fibers, rayon-based carbon fibers, lignin-based carbon fibers, pitch-based carbon fibers, etc. are preferably used. Among them, polyacrylonitrile (PAN)-based carbon fibers are preferred in the present invention because of their excellent productivity.

[0045] In the present invention, when porous substrate 50 is used for the core layer, the value of the ratio λ22 / λ1A of the thermal conductivity to the prepreg is preferably greater than 0 and not greater than 1.0 for the same reasons as for the ratio λ21 / λ1A of the thermal conductivity of foamed molded body 40 to the thermal conductivity of the prepreg described above, and is more preferably greater than 0 and less than 0.5 from the viewpoint of lightness and rigidity, and even more preferably greater than 0 and less than 0.1 from the viewpoint of heat dissipation.

[0046] The thermal conductivity λ22 [W / (m·K)] in the fiber direction of the carbon fiber used in the core layer is preferably 50 W / (m·K) or less. If it exceeds 50 W / (m·K), the generated heat will be transferred to the inside / outside, potentially affecting internal components or causing burns during use. It is preferably 0.1 W / (m·K) or more and 10 W / (m·K) or less, and more preferably 3 W / (m·K) or more and 8 W / (m·K) or less. The thermal conductivity in the fiber direction of the carbon fiber can be measured by the test described in JIS A1412-2 (1999).

[0047] The weight fiber content of the discontinuous fibers constituting the core layer is preferably 5 to 75% by mass, and the weight content of the thermoplastic resin is preferably 25 to 95% by mass.

[0048] In forming the core layer, the blending ratio of the discontinuous fibers to the thermoplastic resin is one factor that determines the porosity. There are no particular limitations on the method for determining the blending ratio of the discontinuous fibers to the thermoplastic resin. For example, the blending ratio can be determined by removing the resin component contained in the core layer and measuring the weight of only the remaining discontinuous fibers. Examples of methods for removing the resin component contained in the core layer include a dissolution method and a burn-off method. The weight can be measured using an electronic balance. The size of the molding material to be measured is 100 mm × 100 mm square, and measurements are made three times, and the average value can be used.

[0049] The core layer preferably contains 7 to 70% by mass of discontinuous fibers and 30 to 93% by mass of thermoplastic resin, more preferably 20 to 50% by mass of discontinuous fibers and 50 to 80% by mass of thermoplastic resin, and even more preferably 25 to 40% by mass of discontinuous fibers and 60 to 75% by mass of thermoplastic resin. If the discontinuous fibers are less than 5% by mass and the thermoplastic resin is more than 95% by mass, springback is less likely to occur, making it difficult to increase the porosity. This may make it difficult to create regions of different porosity in the core layer, resulting in a decrease in the bond strength to the structure. On the other hand, if the discontinuous fibers are more than 75% by mass and the thermoplastic resin is less than 25% by mass, the specific rigidity of the laminate 20 decreases.

[0050] In the present invention, the number-average fiber length of the discontinuous fibers constituting the core layer is preferably 0.5 to 50 mm. By setting the number-average fiber length of the discontinuous fibers to a specific length, it is possible to ensure the generation of voids due to springback in the core layer. The number-average fiber length is preferably 0.8 to 40 mm, more preferably 1.5 to 20 mm, and even more preferably 3 to 10 mm. If the number-average fiber length is shorter than 0.5 mm, it may be difficult to form voids of a certain size or larger. On the other hand, if the number-average fiber length is longer than 50 mm, it becomes difficult to randomly disperse the fibers from the fiber bundle, and the core layer cannot generate sufficient springback, which limits the size of the voids and reduces the bonding strength with the structure.

[0051] One method for measuring the fiber length of discontinuous fibers is to directly extract discontinuous fibers from a discontinuous fiber group and measure them under a microscope. When resin adheres to the discontinuous fiber group, the resin is dissolved from the discontinuous fiber group using a solvent that dissolves only the resin contained therein, and the remaining discontinuous fibers are filtered and measured under a microscope (dissolution method). When no solvent is available to dissolve the resin, the resin alone is burned off within a temperature range where the discontinuous fibers do not oxidize and lose weight, and the discontinuous fibers are separated and measured under a microscope (burn-off method). Four hundred discontinuous fibers are randomly selected from the discontinuous fiber group, and their lengths are measured to the nearest 1 μm using an optical microscope to determine the fiber length and its ratio. When comparing the method of directly extracting discontinuous fibers from a discontinuous fiber group with the method of extracting discontinuous fibers using the burn-off method or dissolution method, there is no significant difference in the results obtained by appropriately selecting the conditions. Among these measurement methods, the dissolution method is preferred because it results in minimal change in the weight of the discontinuous fibers.

[0052] A discontinuous fiber mat suitable for use in a core layer having voids or a molded article in which discontinuous fibers are impregnated with a thermoplastic resin is produced, for example, by dispersing discontinuous fibers in advance in the form of fiber bundles and / or monofilaments. Specific methods for producing a discontinuous fiber mat include dry processes such as the airlaid method, in which discontinuous fibers are dispersed into a sheet by an airflow, and the carding method, in which discontinuous fibers are mechanically combed into a sheet, and a wet process such as the Radlite method, in which discontinuous fibers are stirred in water to form a paper.

[0053] Examples of means for making the discontinuous fibers closer to the monofilament state in a dry process include providing a fiber-opening bar, vibrating the fiber-opening bar, making the card mesh finer (ultra-fine), and adjusting the rotation speed of the card. Examples of means for making the discontinuous fibers closer to the monofilament state in a wet process include adjusting the stirring conditions of the discontinuous fibers, diluting the reinforcing fiber concentration in the dispersion, adjusting the viscosity of the dispersion, and suppressing vortex flow when the dispersion is transported.

[0054] In particular, discontinuous fiber mats are preferably produced by a wet method, and the proportion of reinforcing fibers in the discontinuous fiber mat can be easily adjusted by increasing the concentration of the input fibers or adjusting the flow rate (flow rate) of the dispersion and the speed of the mesh conveyor. For example, by slowing the speed of the mesh conveyor relative to the flow rate of the dispersion, the fibers in the resulting discontinuous fiber mat are less likely to be oriented in the take-up direction, making it possible to produce a bulky discontinuous fiber mat. The discontinuous fiber mat may be composed of discontinuous fibers alone, or the discontinuous fibers may be mixed with a powder or fibrous matrix resin component, or the discontinuous fibers may be mixed with an organic or inorganic compound, or the discontinuous reinforcing fibers may be sealed with a resin component.

[0055] The type of thermoplastic resin used in the core layer is not particularly limited, and any of the thermoplastic resins exemplified below can be used. For example, polyester resins such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polytrimethylene terephthalate (PTT) resin, polyethylene naphthalate (PEN resin), and liquid crystal polyester resin; polyolefin resins such as polyethylene (PE resin), polypropylene (PP resin), and polybutylene resin; polyarylene sulfide resins such as polyoxymethylene (POM) resin, polyamide (PA) resin, and polyphenylene sulfide (PPS) resin; fluorine-based resins such as polyketone (PK) resin, polyether ketone (PEK) resin, polyether ether ketone (PEEK) resin, polyether ketone ketone (PEKK) resin, polyether nitrile (PEN) resin, and polytetrafluoroethylene resin; crystalline resins such as liquid crystal polymers (LCP); In addition to ethylene-based resins, examples of the resin include amorphous resins such as polycarbonate (PC) resin, polymethyl methacrylate (PMMA) resin, polyvinyl chloride (PVC) resin, polyphenylene ether (PPE) resin, polyimide (PI) resin, polyamideimide (PAI) resin, polyetherimide (PEI) resin, polysulfone (PSU) resin, polyethersulfone resin, and polyarylate (PAR) resin; and thermoplastic resins selected from phenol-based resins, phenoxy resins, and thermoplastic elastomers such as polystyrene-based resins, polyolefin-based resins, polyurethane-based resins, polyester-based elastomer resins, polyamide-based elastomer resins, polybutadiene-based resins, polyisoprene-based resins, fluorine-based elastomer resins, and acrylonitrile-based elastomer resins, as well as copolymers and modified products thereof. Among these, polyolefin resins are preferred from the viewpoint of the light weight of the resulting molded product, polyamide resins are preferred from the viewpoint of strength, amorphous resins such as polycarbonate resins, styrene-based resins, and modified polyphenylene ether-based resins are preferred from the viewpoint of surface appearance, polyarylene sulfide resins are preferred from the viewpoint of heat resistance, and polyether ether ketone resins are preferably used from the viewpoint of continuous use temperature.

[0056] The exemplified thermoplastic resins may contain impact resistance improvers such as elastomers or rubber components, other fillers, and additives, provided that the object of the present invention is not impaired. Examples of these include inorganic fillers, flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration dampers, antibacterial agents, insect repellents, deodorizing agents, color inhibitors, heat stabilizers, release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, foam control agents, and coupling agents.

[0057] In the present invention, the laminate 20 is formed by laminating at least two layers of prepreg made of at least continuous fibers and a thermoplastic resin or a thermosetting resin, and the total thickness is preferably 0.3 mm or more and 2.0 mm or less. If it is thinner than 0.3 mm, the rigidity of the integrally molded body 10 may be insufficient, and the difference in thermal conduction between the thickness and planar directions may be small, resulting in a loss of heat dissipation. If it is thicker than 2.0 mm, the light weight may be lost. More preferably, the thickness is 0.7 mm or more and 1.5 mm or less from the viewpoints of rigidity, heat dissipation, and light weight.

[0058] Furthermore, for laminates 20 in which the core layer is a porous substrate, a step portion may be set within the above-mentioned total thickness range in the in-plane direction, comprising a first flat prepreg region 21a, an inclined prepreg region 21b, and a second flat prepreg region 21c, as shown in FIG. 6. It is preferable to have a prepreg region 21b with an inclined surface at an angle of 10° to 90° relative to the in-plane direction of the first flat prepreg region 21a provided on the laminate 20. By configuring the step portion, it is possible to set a bonding surface 31 with the laminate in the second flat prepreg region 21c. As a result, the thickness direction length 32 of the bonding portion with the laminate 20 can be increased without changing the thickness of the structure, thereby improving bonding strength and reducing the thickness of the integrally molded body 10 from the perspective of improving fluidity during injection molding.

[0059] Here, the inclination angle θ (°) in the in-plane direction formed by the first flat portion and the inclined surface is preferably 10° to 90°.

[0060] In the present invention, the resin used for the structure 30 is not particularly limited, and the above-mentioned thermoplastic resin or thermosetting resin can be used. Among these, thermoplastic resins are preferred, and by forming a joint structure in which the thermoplastic resin of the structure 30 and the thermoplastic resin substrate 70 are melt-bonded, a higher joint strength can be achieved as the integrally molded body 10. A melt-bonded joint structure is a joint structure in which mutual components are melted by heat and then cooled to become solidified. In particular, PPS resin is more preferably used from the viewpoints of heat resistance and chemical resistance, polycarbonate resin or styrene-based resin from the viewpoints of the appearance and dimensional stability of the molded product, and polyamide resin from the viewpoints of the strength and impact resistance of the molded product.

[0061] In addition, to increase the strength and rigidity of the integrally molded body 10, it is also preferable to use a resin containing reinforcing fibers as the material of the structure 30. Examples of reinforcing fibers include metal fibers such as aluminum fibers, brass fibers, and stainless steel fibers; inorganic fibers such as polyacrylonitrile-, rayon-, lignin-, and pitch-based carbon fibers, graphite fibers, glass fibers, silicon carbide fibers, and silicon nitride fibers; and organic fibers such as aramid fibers, polyparaphenylene benzobisoxazole (PBO) fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers, and polyethylene fibers. These reinforcing fibers may be used alone or in combination of two or more. Among these, carbon fibers and glass fibers are preferred from the viewpoint of strength. Glass fibers are more preferred, as using glass fibers as the reinforcing fibers of the structure 30 can impart the structure with the function of a radio wave-transmitting member.

[0062] Furthermore, the resin constituting the structure 30 may contain other fillers or additives depending on the required properties, provided that the purpose of the present invention is not impaired. Examples include inorganic fillers, non-phosphorus-based flame retardants, conductivity imparting agents, crystal nucleating agents, ultraviolet absorbers, antioxidants, vibration dampers, antibacterial agents, insect repellents, deodorizers, color inhibitors, heat stabilizers, release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, foam control agents, and coupling agents.

[0063] The weight fiber content of the reinforcing fibers is preferably 1 to 60% by mass of discontinuous fibers. This increases the bonding strength and reduces warpage of the integrally molded body 10. If it is less than 1% by mass, it may be difficult to ensure the strength of the integrally molded body 10, and if it exceeds 60% by mass, filling of the structure 30 may be partially insufficient during injection molding. From the viewpoint of moldability of the structure, the weight fiber content is preferably 5 to 55% by mass, more preferably 8 to 50% by mass, and even more preferably 12 to 45% by mass.

[0064] In the present invention, in relation to the bonding strength of the integrally molded body 10, the laminate 20 having the core layer preferably has a fitting portion in which the structure 30 fits into a part of the laminate 20.

[0065] When the structure 30 is formed by injection molding, the structure 30 and the flat or side surface portions of the prepreg layers of the laminate 20 are bonded, and the structure 30 penetrates into a portion of the core layer from the side surface of the laminate 20 due to the injection molding pressure. This is because the region within the core layer has a high porosity, making it easy for the molten structure 30 to penetrate. Furthermore, by using a porous substrate made of discontinuous fibers and a thermoplastic resin for the core layer, the structure 30 penetrates into the core layer, creating an anchor effect, thereby further increasing the bonding strength.

[0066] In addition, in the configuration of the structure 30, as shown in FIG. 7, before injecting the resin member, a resin frame may be placed as a separate member on the outer periphery of the laminate 20, and the resin member may then be injection molded. This is also an effective means for realizing low warpage of the integrally molded body 10.

[0067] The resin frame 80 is preferably a fiber-reinforced resin frame made of reinforcing fibers and resin from the viewpoint of the strength and rigidity of the integrally molded body 10. The reinforcing fibers can be those used in the resin members described above, and in the present invention, glass fiber and carbon fiber are preferred from the viewpoint of increasing the strength of the resin frame 80, and in the present invention, glass fiber is preferably used as the reinforcing fiber from the viewpoint of antenna performance. When carbon fiber is used as the reinforcing fiber, although its antenna performance is inferior to that of glass fiber, it is also an effective means of using it for the purpose of improving strength and rigidity.

[0068] In the present invention, from the viewpoints of reducing the thickness and cost of the laminate 20, the prepregs constituting the laminate may be configured to include heterogeneous carbon fiber prepregs, in which the continuous carbon fibers constituting the prepregs other than the first prepreg 21 are made of a different type of carbon fiber than the continuous carbon fiber constituting the first prepreg 21. FIG. 2 shows an example of a laminate 20 in which the first prepreg 21 and a second prepreg 22, which is a heterogeneous carbon fiber prepreg, are alternately laminated. Furthermore, among the heterogeneous carbon fiber prepregs, from the viewpoints of transferring generated heat to the inside / outside when used as an electronic casing device and preventing the impact on internal components or the risk of burns during use, the ratio λ1B / λ1A of the thermal conductivity λ1A of the first prepreg 21 to the thermal conductivity λ1B of the carbon fiber with the lowest thermal conductivity is preferably greater than 0 and less than 1.0. From the viewpoints of lightness and rigidity, the ratio is more preferably greater than 0 and less than 0.5, and from the viewpoint of heat dissipation, it is even more preferably greater than 0 and less than 0.1. Here, the thermal conductivity λ1B of the carbon fiber with the lowest thermal conductivity is preferably 0.1 W / (m K) or more and 10 W / (m K) or less, more preferably 3 W / (m K) or more and 8 W / (m K) or less. The thermal conductivity in the fiber direction of the carbon fiber can be measured by the test described in JIS A1412-2 (1999).

[0069] In the present invention, a continuous fiber woven fabric substrate 60 may be disposed on the outer side of at least one of the outermost layers of the laminate 20 to form a design surface. By arranging a woven fabric pattern on the design surface side, a product with a highly designed design can be obtained. Furthermore, it is preferable to appropriately combine the number of prepreg layers, the type of carbon fiber, and the type of resin that constitute the laminate 20 depending on the characteristics and cost required of the integrally molded body 10.

[0070] The continuous fiber woven substrate 60 will now be described. A continuous fiber woven substrate is a substrate in which continuous fiber bundles each consisting of 1,000 continuous fibers are used as warp and weft threads, and two sets of threads are crossed at right angles using a loom. A continuous fiber bundle of 1,000 fibers is generally called 1K, a bundle of 3,000 fibers is called 3K, and a bundle of 12,000 fibers is called 12K.

[0071] Fibers used for the continuous fiber woven substrate 60 include metal fibers such as aluminum fibers, brass fibers, and stainless steel fibers; glass fibers; polyacrylonitrile-, rayon-, lignin-, and pitch-based carbon fibers and graphite fibers; organic fibers such as aromatic polyamide fibers, polyaramid fibers, PBO fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers, and polyethylene fibers; and silicon carbide fibers, silicon nitride fibers, alumina fibers, silicon carbide fibers, and boron fibers. These fibers may be used alone or in combination of two or more. These fiber materials may be surface-treated. Examples of surface treatments include metal deposition treatment, treatment with a coupling agent, treatment with a sizing agent, and treatment with an additive.

[0072] When carbon fibers are used as the continuous fiber woven substrate 60, from the viewpoint of weight reduction, carbon fibers (including graphite fibers) such as polyacrylonitrile (PAN)-based carbon fibers, rayon-based carbon fibers, lignin-based carbon fibers, and pitch-based carbon fibers, which have excellent specific strength and specific rigidity, are preferably used. Among these, PAN-based carbon fibers, which have excellent processability, are desirable.

[0073] The continuous fiber woven substrate 60 is preferably made of at least one woven fabric selected from plain weave, twill weave, satin weave, and satin weave. The continuous fiber woven substrate 60 has a distinctive fiber pattern, which can highlight the distinctive fiber pattern. By using the continuous fiber woven substrate 60 on the outer side of the outermost layer (the design surface side), the shape pattern of the continuous fiber woven fabric can be made to stand out, resulting in the development of an innovative surface pattern. The continuous fiber bundle is preferably 1K to 24K, and more preferably 1K to 6K from the viewpoint of the stability of the fiber pattern during processing.

[0074] In the present invention, as shown in FIG. 5, for example, a thermoplastic resin layer can be provided by disposing a thermoplastic resin substrate 70 at least partially between the prepreg and the structure and / or between the core layer and the structure.

[0075] Here, the thermoplastic resin substrate 70 can be made of an acrylic, epoxy, styrene, nylon, ester, or other adhesive, a thermoplastic resin film, a nonwoven fabric, or the like. Furthermore, using the same material as the structure can increase the bonding strength. The resin used in the outermost layer of the prepreg or core layer does not have to be the same resin as the adhesive used in the thermoplastic resin substrate 70, as long as it has good compatibility, and it is preferable to select an optimal resin depending on the type of resin constituting the structure.

[0076] In the present invention, from the viewpoint of the rigidity and thinness of the integrally molded body 10, it is preferable that the porosity of the porous substrate in the porous substrate region 50b of the inclined portion and the porous substrate region 50c of the second flat portion be lower than that of the porous substrate region 50a of the first flat portion, as shown in the cross-sectional views of Figures 6 and 7.

[0077] The integrally molded body 10 of the present invention and a method for producing the same will be described in detail below with reference to examples, but the present invention is not limited to the following examples.

[0078] (1) Heat Dissipation of the Integrated Molded Body 10 A micro ceramic heater (product number: MC1010) manufactured by Sakaguchi Electric Heating Co., Ltd. was used to evaluate heat dissipation. Using the integrated molded body 10 shown in FIG. 1 , a heater (not shown) heated to 40°C and stabilized at that temperature was placed in contact with the central portion of the design surface side of the integrated molded body 10, and the heater was immediately turned off and left for 10 minutes. After removing the heater, the maximum temperature areas on the design surface side and non-design surface side were confirmed with a thermograph and the maximum temperatures were measured. Furthermore, the maximum surface temperatures obtained were evaluated as A, B, and C according to the following criteria. The measurement on the design surface side was evaluated as heat dissipation X, and the measurement on the non-design surface side was evaluated as heat dissipation Y. A rating of A or B for both heat dissipation X and heat dissipation Y was considered a pass, while any other rating was considered a fail.

[0079] A: Maximum temperature is less than 25°C. B: Maximum temperature is 25°C or more and less than 30°C. C: Maximum temperature is 30°C or more. (2) Lightweightness of laminate 20 A sample measuring 100 mm wide and 100 mm long (thickness is the thickness of laminate 20) was cut out from laminate 20, and the specific gravity was calculated from its mass W and apparent volume V using the following formula.

[0080] Specific gravity = W / V Furthermore, if the specific gravity value was lighter than that of magnesium (AZ91, specific gravity 1.82), which is a metal material, it was deemed to have passed, otherwise it was deemed to have failed.

[0081] (Material Composition Example 1-1) Unidirectional Prepreg (C-1) 21: A pitch-based prepreg was used as a unidirectional prepreg (C-1) 21 (GRANOC Prepreg (registered trademark), E8026A-07S, manufactured by Nippon Graphite Fiber Co., Ltd., with a thermal conductivity in the fiber direction of 320 W / (m K), a tensile modulus of elasticity of 785 GPa, and a fiber density of 2.17 g / m). ３ The prepreg was made of pitch-based continuous carbon fiber and resin.

[0082] (Material Composition Example 1-2) Unidirectional prepreg (C-2) 21: PAN-based prepreg, unidirectional prepreg (C-2) 21 ("TORAYCA PREPREG" (registered trademark) manufactured by Toray Industries, Inc., product number P3252S-10, thermal conductivity in the fiber direction 5 W / (m K), tensile modulus 230 GPa, fiber density 1.8 g / m ３ A prepreg made of PAN-based continuous carbon fiber and resin was used.

[0083] (Material Composition Example 2) Foam Molded Article 40 A non-crosslinked low-foam polypropylene sheet "EF-CELL" (registered trademark) (double-expanded) (manufactured by Furukawa Electric Co., Ltd.) was used.

[0084] (Material Composition Example 3) Chopped Carbon Fiber Bundle Using a cartridge cutter, PAN-based carbon fiber (Toray Industries, Inc., "Torayca Yarn" (registered trademark), product type T700SC, carbon fiber having a thermal conductivity in the fiber direction of 10 W / (m·K)) was cut to obtain a chopped carbon fiber bundle having a fiber length of 6 mm.

[0085] (Material Composition Example 4) Carbon Fiber Mat 100 L of a 1.5 wt % aqueous solution of a surfactant (manufactured by Wako Pure Chemical Industries, Ltd., product name "sodium n-dodecylbenzenesulfonate") was stirred to prepare a pre-foamed dispersion. The chopped carbon fiber bundles obtained in (Material Composition Example 3) were added to this dispersion, and after stirring, the dispersion was poured into a paper machine with a papermaking surface of 400 mm long x 400 mm wide, dehydrated by suction, and then dried at a temperature of 150°C for 2 hours to obtain a carbon fiber mat. The obtained mat was in a well-dispersed state.

[0086] (Material Composition Example 5) Polypropylene Resin Film 90% by mass of unmodified polypropylene resin (Prime Polypro (registered trademark) J105G, melting point 160°C, manufactured by Prime Polymer Co., Ltd.) and 10% by mass of acid-modified polypropylene resin (Admer (registered trademark) QE510, melting point 160°C, manufactured by Mitsui Chemicals, Inc.) were dry-blended, and a polypropylene resin film was obtained using the dry-blended resin.

[0087] (Material Composition Example 6) Porous Substrate 50 Material Composition Example 4 and Material Composition Example 5 were laminated in the order of [polypropylene resin film / carbon fiber mat / polypropylene resin film].

[0088] (Material Composition Example 7) Glass Fiber Reinforced Polycarbonate Compound pellets of glass fiber reinforced polycarbonate ("Panlite" (registered trademark) GXV-3545WI (manufactured by Teijin Chemicals Ltd.)) were used.

[0089] (Material Composition Example 8) Thermoplastic Resin Substrate 70 A polyester-based elastomer resin (Hytrel (registered trademark) manufactured by DuPont-Toray Co., Ltd.) was used to obtain a polyester resin film having a thickness of 0.05 mm. This was used as the thermoplastic resin substrate 70.

[0090] Example 1 When producing an integrally molded body 10 as shown in FIG. 1, the unidirectional prepreg (C-1) 21 prepared in Material Composition Example 1-1, the foam molded body 40 prepared in Material Composition Example 2, and the thermoplastic resin substrate 70 prepared in Material Composition 8 were used, each adjusted to 400 mm x 400 mm, and then laminated in the order of [unidirectional prepreg (C-1) 21 0° / unidirectional prepreg (C-1) 21 90° / foam molded body 40 / unidirectional prepreg (C-1) 21 90° / unidirectional prepreg (C-1) 21 0° / thermoplastic resin substrate 70], and press-molded in a flat plate mold heated to 150°C under the conditions of 3 MPa x 5 minutes to obtain a laminate 20.

[0091] Next, the obtained laminate 20 was processed to 300 mm x 200 mm and set in an injection mold, and was injection molded using glass fiber reinforced polycarbonate of material composition 7 at 150 MPa, a cylinder temperature of 320 ° C, a mold temperature of 120 ° C, and a resin discharge port Φ of 3 mm to form a structure 30, and the integrally molded body 10 shown in Figure 1 was manufactured. The heat dissipation of the obtained integrally molded body 10 was measured using the method described above. As a result, both heat dissipation X and heat dissipation Y were good results, with a passing rating of A. The properties of the integrally molded body 10 are summarized in Table 1.

[0092] (Example 2) Using the unidirectional prepreg (C-1) 21 prepared in Material Composition Example 1-1, the porous substrate 50 prepared in Material Composition Example 6, and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each was adjusted to 400 mm × 400 mm, and then laminated in the order of [unidirectional prepreg (C-1) 21 0 ° / unidirectional prepreg (C-1) 21 90 ° / porous substrate 50 / unidirectional prepreg (C-1) 21 90 ° / unidirectional prepreg (C-1) 21 0 ° / thermoplastic resin substrate 70], and then press-molded under the conditions of 3 MPa × 5 minutes in a flat plate mold heated to 180 ° C., then the mold spacing was widened to 1.15 mm and 3 MPa × 3 minutes, and the porous substrate 50 was expanded in the thickness direction by springback to form voids. Thereafter, press molding was performed under the conditions of 3 MPa × 3 minutes using a mold with a step shape at a plate surface temperature of 120 ° C., and the laminate 20 was cooled to form a step shape. As a result, the porosity of the porous substrate was lower in the portion corresponding to the porous substrate region 50 b of the inclined portion than in the portion corresponding to the porous substrate region 50 a of the first flat portion in Figure 6, and the porosity of the portion corresponding to the porous substrate region 50 c of the second flat portion became even lower.

[0093] The obtained laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation of the obtained integrally molded body 10 was measured by the method described above. As a result, both heat dissipation X and heat dissipation Y were good results, being judged as passing with an A. The properties of the integrally molded body 10 are summarized in Table 1.

[0094] Example 3 Using the unidirectional prepreg (C-1) 21 prepared in Material Composition Example 1-1, the unidirectional prepreg (C-2) 21 prepared in Material Composition Example 1-2, and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each was adjusted to 400 mm x 400 mm, and then laminated in the order of [unidirectional prepreg (C-1) 21 0° / unidirectional prepreg (C-2) 21 90° / unidirectional prepreg (C-2) 21 0° / unidirectional prepreg (C-2) 21 90° / unidirectional prepreg (C-1) 21 0° / thermoplastic resin substrate 70], and press-molded in a flat plate mold heated to 150°C under the conditions of 3 MPa x 5 minutes to obtain a laminate 20.

[0095] Next, the obtained laminate 20 was processed to 300 mm x 200 mm and set in an injection mold under the same conditions as in Example 1, and the heat dissipation of the obtained integrally molded body 10 was measured using the method described above. As a result, both heat dissipation X and heat dissipation Y were good enough to be judged as passing, with a grade of A. The properties of the integrally molded body 10 are summarized in Table 1.

[0096] Example 4 Using the unidirectional prepreg (C-1) 21 prepared in Material Composition Example 1-1 and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each was adjusted to 400 mm x 400 mm, and then laminated in the order of [unidirectional prepreg (C-1) 21 0° / unidirectional prepreg (C-1) 21 90° / unidirectional prepreg (C-1) 21 0° / unidirectional prepreg (C-1) 21 90° / unidirectional prepreg (C-1) 21 0° / thermoplastic resin substrate 70], and press-molded in a flat plate mold heated to 150°C under the conditions of 3 MPa x 5 minutes to obtain a laminate 20.

[0097] The obtained laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation of the obtained integrally molded body 10 was measured by the method described above. As a result, both heat dissipation X and heat dissipation Y were good results, being judged as passing with a grade of B. The properties of the integrally molded body 10 are summarized in Table 1.

[0098] Comparative Example 1 Using the unidirectional prepreg (C-2) 21 prepared in Material Composition Example 1-2 and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each was adjusted to 400 mm x 400 mm, and then laminated in the order of [unidirectional prepreg (C-2) 21 0° / unidirectional prepreg (C-2) 21 90° / unidirectional prepreg (C-2) 21 0° / unidirectional prepreg (C-2) 21 90° / unidirectional prepreg (C-2) 21 0° / thermoplastic resin substrate 70], and press-molded in a flat plate mold heated to 150°C under the conditions of 3 MPa x 5 minutes to obtain a laminate 20.

[0099] The obtained laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation of the obtained integrally molded body 10 was measured by the method described above. As a result, the heat dissipation X was evaluated as "fail" and the heat dissipation Y was evaluated as "B", which was an overall "fail" result. The properties of the integrally molded body 10 are summarized in Table 1.

[0100] Comparative Example 2 Using the unidirectional prepreg (C-2) 21 prepared in Material Composition Example 1-2, the foam molded article 40 prepared in Material Composition Example 2, and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each was adjusted to 400 mm x 400 mm, and then laminated in the order of [unidirectional prepreg (C-2) 21 0° / unidirectional prepreg (C-2) 21 90° / foam molded article 40 / unidirectional prepreg (C-2) 21 90° / unidirectional prepreg (C-2) 21 0° / thermoplastic resin substrate 70], and press molding was performed in a flat plate mold heated to 150°C under the conditions of 3 MPa x 5 minutes, to obtain a laminate 20.

[0101] The obtained laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation of the obtained integrally molded body 10 was measured by the method described above. As a result, the heat dissipation X was evaluated as "fail" and the heat dissipation Y was evaluated as "B", resulting in an overall evaluation of "fail." The properties of the integrally molded body 10 are summarized in Table 1.

[0102] Comparative Example 3 Using the unidirectional prepreg (C-1) 21 prepared in Material Composition Example 1-1, the unidirectional prepreg (C-2) 21 prepared in Material Composition Example 1-2, and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each was adjusted to 400 mm x 400 mm, and then laminated in the order of [unidirectional prepreg (C-2) 21 0 ° / unidirectional prepreg (C-1) 21 90 ° / unidirectional prepreg (C-1) 21 0 ° / unidirectional prepreg (C-1) 21 90 ° / unidirectional prepreg (C-2) 21 0 ° / thermoplastic resin substrate 70], and press-molded in a flat plate mold heated to 150 ° C. under the conditions of 3 MPa x 5 minutes to obtain a laminate 20.

[0103] The obtained laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation of the obtained integrally molded body 10 was measured by the method described above. As a result, the heat dissipation X was evaluated as "fail" and the heat dissipation Y was evaluated as "B", resulting in an overall evaluation of "fail." The properties of the integrally molded body 10 are summarized in Table 1.

[0104]

[0105] The integrally molded body 10 of the present invention can be effectively used for automobile interiors and exteriors, electrical and electronic equipment housings, bicycles, structural materials for sporting goods, aircraft interior materials, transport boxes, and the like.

[0106] REFERENCE SIGNS LIST 10 Integrated molded body 20 Laminate 21 First prepreg 21a Prepreg region of first flat portion 21b Prepreg region of inclined portion 21c Prepreg region of second flat portion 22 Second prepreg 30 Structure 31 Bonding surface with laminate 32 Length in thickness direction of bonding portion with laminate 40 Foam molded body 50 Porous substrate 50a Porous substrate region of first flat portion 50b Porous substrate region of inclined portion 50c Porous substrate region of second flat portion 60 Continuous fiber woven fabric substrate 70 Thermoplastic resin substrate 80 Resin frame

Claims

1. An integrally molded body in which a structure made of thermoplastic resin and reinforcing fibers is arranged on the outer periphery of a laminate in which at least prepregs made of continuous carbon fiber and resin are laminated, wherein the thermal conductivity λ1A in the fiber direction of the continuous carbon fibers of a first prepreg constituting the outermost layer of the laminate is 100 [W / (m K)] or more and 800 [W / (m K)] or less.

2. 2. The integrally molded body according to claim 1, wherein the laminate is a sandwich structure composed of a core layer and a prepreg, the prepreg being disposed on both sides of the core layer.

3. 3. The integrally molded product according to claim 2, wherein the core layer is a foamed molded product made of a foam resin, or a porous substrate made of discontinuous fibers and a thermoplastic resin.

4. The integrally molded body according to claim 1, which satisfies the following (i) and / or (ii): (i) The laminate is a sandwich structure composed of a core layer and a prepreg, the prepreg being disposed on both sides of the core layer, and satisfies the following (i-1) or (i-2): (i-1) The core layer is a foamed molded body made of a foam resin, and the ratio λ21 / λ1A of the thermal conductivity λ21 to the thermal conductivity λ1A of the foamed molded body is greater than 0 and is equal to or less than 0.

05. (i-2) The core layer is a porous substrate made of discontinuous fibers and a thermoplastic resin, the discontinuous fibers constituting the porous substrate are carbon fibers, and the ratio λ22 / λ1A of the thermal conductivity λ22 in the fiber direction of the discontinuous fibers to the thermal conductivity λ1A is greater than 0 and less than or equal to 1.

0. (ii) The prepregs constituting the laminate include heterogeneous carbon fiber prepregs in which continuous carbon fibers constituting prepregs other than the first prepreg are made of a different type of carbon fiber than the continuous carbon fibers constituting the first prepreg, and a ratio λ1B / λ1A of the thermal conductivity λ1A to the thermal conductivity λ1B of a carbon fiber having the lowest thermal conductivity among the heterogeneous carbon fiber prepregs is greater than 0 and less than or equal to 1.

0.

5. The density of the continuous carbon fiber constituting the first prepreg is 2.0 g / cm ３ ~2.5g / cm ３ 2. The integrally molded body according to claim 1,

6. 2. The integrally molded body according to claim 1, wherein a continuous fiber woven fabric substrate is disposed on the outer side of at least one of the outermost layers of the laminate to form a design surface.

7. The integrally molded body according to claim 1 , further comprising a thermoplastic resin substrate provided at least partially between the laminate and the structural body.

8. 2. The integrally molded product according to claim 1, which is used as a housing for an electronic device.

9. An electronic device housing comprising the integrally molded product according to claim 1.