Integrated molded body and electronic device housing

Abstract

The present application provides a laminated body having excellent thermal conductivity, lightness and rigidity, and an integrated molded body in which the laminated body is integrated with other components. The integrated molded body of the present application is an integrated molded body in which a structure formed of a thermoplastic resin and a reinforcing fiber is arranged on the outer peripheral portion of a laminated body in which at least a prepreg formed of a continuous carbon fiber and a resin is laminated, and the thermal conductivity λ1A in the fiber direction of the continuous carbon fiber of the first prepreg constituting the outermost layer of the laminated body is 100 [W / (m·K)] or more and 800 [W / (m·K)] or less. It is preferably used for an electronic device housing.

Description

Technical Field

[0001] The present invention relates to an integral molded body and electronic device housing having lightweight, rigidity and excellent thermal conductivity, wherein the integral molded body comprises a laminate with excellent lightweight, thin-walled and rigid properties using continuous carbon fibers with specific thermal conductivity. Background Technology

[0002] Currently, the demands for portability and high performance in electrical and electronic equipment such as personal computers, OA equipment, AV equipment, mobile phones, telephones, fax machines, home appliances, and toys are constantly increasing. To meet these requirements, in addition to being lightweight and miniaturized, the components that make up the equipment, especially the housing, also require excellent heat dissipation to efficiently release the heat generated by the internal components to the outside of the product, protecting the internal components from the effects of external heat.

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

[0004] Patent Document 2 provides a thermally conductive molded body, which is a molded body integrally formed from a first part and a second part of a resin composition reinforced with continuous reinforcing fibers. This ensures lightweight and mechanical properties, and both the reinforcing fibers used in the first part and the second part have high thermal conductivity, thereby maintaining the characteristics of a thermally conductive molded body. Simultaneously, the first and second parts are firmly integrally formed with excellent bonding strength. Furthermore, a bonding method that enables the simultaneous realization of complex shape molding and high productivity in this thermally conductive molded body is disclosed.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2016 / 002457

[0008] Patent Document 2: Japanese Patent No. 4973364 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, regarding Patent Document 1, it requires stacking substrates of different materials and integrating them into a single unit, which makes the adhesion and warpage management of each layer difficult and causes problems with moldability. Furthermore, regarding Patent Document 2, because the integrated molded body itself has high thermal conductivity, in electronic device applications, there is a problem that external heat is also conducted into the interior of the product.

[0011] The object of this invention is to provide a laminate with excellent thermal conductivity, lightweight, and rigidity, addressing the limitations of existing technologies. Another object of this invention is to provide an integrally molded body and electronic device housing that integrates the laminate with other components, exhibiting excellent thermal conductivity, lightweight, and rigidity.

[0012] Methods for solving problems

[0013] To address the aforementioned issues, the integral molded body of the present invention adopts the following configuration.

[0014] (1) An integral molded body, which is an integral molded body in which a structure formed of thermoplastic resin and reinforcing fiber is disposed on the outer periphery of a laminate in which at least a prepreg blank formed of continuous carbon fiber and resin is stacked, wherein the thermal conductivity λ1A of the continuous carbon fiber of the first prepreg blank constituting the outermost layer of the laminate is 100[W / (m·K)] or more and 800[W / (m·K)] or less in the fiber direction.

[0015] (2) The integral molded body as described in (1), wherein the laminated body is a sandwich structure consisting of a core layer and a prepreg blank, with the prepreg blank disposed on both sides of the core layer.

[0016] (3) The integral molded body as described in (2), wherein the core layer is a foamed molded body formed of foamed resin or a porous substrate formed of discontinuous fibers and thermoplastic resin.

[0017] (4) An integral molded body as described in any one of (1) to (3) satisfies (i) and / or (ii) below.

[0018] (i) The above-mentioned laminate is a sandwich structure consisting of a core layer and a prepreg blank, with the prepreg blank disposed on both sides of the core layer, satisfying (i-1) or (i-2) below.

[0019] (i-1) The core layer is a foamed molded body formed of foamed resin, and the ratio of the thermal conductivity λ21 to the thermal conductivity λ1A of the foamed molded body, λ21 / λ1A, is greater than 0 and less than 0.05.

[0020] (i-2) The core layer is a porous substrate formed of discontinuous fibers and thermoplastic resin. The discontinuous fibers constituting the porous substrate are carbon fibers. The ratio of the thermal conductivity λ22 to the thermal conductivity λ1A in the fiber direction of the discontinuous fibers, λ22 / λ1A, is greater than 0 and less than 1.0.

[0021] (ii) The prepreg blank constituting the above-mentioned laminate includes a dissimilar carbon fiber prepreg blank, wherein the continuous carbon fibers constituting the prepreg blank other than the first prepreg blank 21 are formed of a different type of carbon fiber than the continuous carbon fibers constituting the first prepreg blank 21, and the ratio of the thermal conductivity λ1B of the carbon fiber with the lowest thermal conductivity in the dissimilar carbon fiber prepreg blank to the thermal conductivity λ1A, λ1B / λ1A, is greater than 0 and less than 1.0.

[0022] (5) The integral molded body as described in any one of (1) to (4), wherein the density of the continuous carbon fibers constituting the first prepreg blank is 2.0 g / cm³. 3 ~2.5g / cm 3 .

[0023] (6) The integral molded body as described in any one of (1) to (5), wherein a continuous fiber fabric substrate is disposed on the outer side of at least one of the outermost layers of the above-mentioned laminated body as a design surface.

[0024] (7) The integral molded body as described in any one of (1) to (6), wherein at least a portion between the laminate and the structure is provided with a thermoplastic resin substrate.

[0025] (8) The integral molded body as described in any one of (1) to (7) is used as an electronic device housing.

[0026] (9) An electronic device housing comprising any one of (1) to (8) an integral molded body.

[0027] Invention Effects

[0028] This invention provides an integrated molded body and electronic device housing that integrate a laminated body with excellent thermal conductivity, lightweight, and rigidity with other components. The integrated molded body according to this invention can suppress the conduction of heat received from the outside or inside to the opposite surface, allowing heat to diffuse in the in-plane direction. This results in an integrated molded body and electronic device housing that prevents the influence of external heat and localized high temperatures on the design surface caused by internal heat generation. Attached Figure Description

[0029] [ Figure 1 [This is a schematic perspective view of an integral molded body 10 according to an embodiment of the present invention.]

[0030] [ Figure 2 ] for along Figure 1A schematic cross-sectional view along line A-A' of the integral molded body 10 formed by joining resin components to the outer periphery of the laminate 20 composed of the first prepreg blank 21 and the second prepreg blank.

[0031] [ Figure 3 [A schematic cross-sectional view in the thickness direction of an integral molded body 10, which has a core layer formed by a foamed molded body 40 and resin components joined at the outer periphery of the laminate 20.]

[0032] [ Figure 4 A schematic cross-sectional view in the thickness direction of an integral molded body 10 formed by placing a continuous fiber fabric substrate as the design surface on the outer side of the laminate 20 formed by the first prepreg blank 21 and the second prepreg blank.

[0033] [ Figure 5 A schematic cross-sectional view in the thickness direction of an integral molded body 10 formed by joining resin components to the outer periphery of a laminate 20 having a thermoplastic resin layer.

[0034] [ Figure 6 [A schematic cross-sectional view in the thickness direction of an integral molded body 10 formed by bonding resin components to the outer periphery of a laminate 20 having a core layer formed of a porous substrate 50 and a thickness difference.]

[0035] [ Figure 7 This is a schematic cross-sectional view in the thickness direction of an integral molded body 10 formed by joining resin components at the outer periphery using a resin frame 80. Detailed Implementation

[0036] The embodiments will now be described using the accompanying drawings. It should be noted that the present invention is not limited to the drawings or embodiments in any way.

[0037] The integral molded body 10 of the present invention is an integral molded body 10 formed by distributing a structure 30 formed of thermoplastic resin and reinforcing fibers on the outer periphery of a laminate 20 having at least a prepreg blank formed of continuous carbon fibers and resin. The continuous carbon fibers used in the first prepreg blank 21 constituting the outermost layer of the laminate 20 have a thermal conductivity λ1A in the fiber direction of 100 [W / (m·K)] or more and 800 [W / (m·K)] or less. Here, "laminate 20 having at least a prepreg blank" means a laminate containing a prepreg blank within a laminate unit, and may include laminate units other than the prepreg blank. In addition, the prepreg blank may also contain other components besides the continuous carbon fibers and resin. It should be noted that the resin here refers to the matrix resin, sometimes to the resin monomer, and sometimes to the resin composition. Similarly, the structure 30 may also contain other components besides the thermoplastic resin and reinforcing fibers.

[0038] The integral molded body 10 involved in this embodiment includes, as follows: Figure 2 The structure shown is formed by joining a structural body 30 to the outer periphery of the laminate 20. The laminate 20 is as described later. Figure 3 This can be achieved by setting a core layer within an inner layer, or as described later. Figure 4 The configuration of the continuous fiber fabric substrate in the design can be determined based on the application and required performance of the integrally molded body 10. It should be noted that... Figure 2 For along Figure 1 A schematic cross-sectional view of the integral molded body 10 along the thickness direction, observed along line A-A', relative to... Figure 1 The flipped state is shown. Additionally, Figures 3 to 7 Similarly, with Figure 1 This is in contrast to the state shown when flipped upside down.

[0039] Here, continuous fibers and discontinuous fibers are defined. Continuous fibers refer to fibers in which the reinforcing fibers included in the integral molded body 10 are arranged substantially continuously along the entire length or width of the integral molded body 10. On the other hand, discontinuous fibers refer to fibers in which the reinforcing fibers are discontinuously segmented. Generally, fibers contained in unidirectional fiber-reinforced resin, which is formed by impregnating resin with unidirectionally filamentous reinforcing fibers, are considered continuous fibers; fibers contained in SMC (sheet molding compound) substrates used for compression molding, and granular materials containing reinforcing fibers used for injection molding, are considered discontinuous fibers. Continuous fibers refer to reinforcing fibers that are continuous in at least one direction for a length of 100 mm or more.

[0040] From the perspective of lightweighting, continuous carbon fibers preferably use polyacrylonitrile (PAN)-based carbon fibers, rayon-based carbon fibers, lignin-based carbon fibers, pitch-based carbon fibers, and other carbon fibers (including graphite fibers) that have excellent specific strength and specific stiffness. In this invention, it is preferable to use pitch-based carbon fibers with excellent thermal conductivity in at least one layer of the laminate 20. From a cost perspective, it is also preferable to use polyacrylonitrile (PAN)-based carbon fibers in combination.

[0041] In this invention, from the viewpoint of heat dissipation of the integral molded body 10, it is important that the thermal conductivity λ1A of the continuous carbon fibers in the fiber direction of the first prepreg blank 21 constituting the outermost layer of the laminate 20 is 100 W / (m·K) or more and 800 W / (m·K) or less. If it is less than 100 W / (m·K), the generated heat cannot be dissipated, heat accumulates inside the product, and internal damage may occur. Preferably, it is 150 W / (m·K) or more and 800 W / (m·K) or less, and from the viewpoint of balancing productivity and thermal conductivity, it is more preferably 300 W / (m·K) or more and 800 W / (m·K) or less. It should be noted that the thermal conductivity in the fiber direction of the carbon fibers can be determined by the test described in JIS A1412-2 (1999).

[0042] By using such continuous carbon fibers, laminates with excellent thermal conductivity, lightweight, and rigidity can be obtained.

[0043] Furthermore, regarding the tensile modulus of continuous carbon fibers, from the perspective of the rigidity of the laminate 20, it is preferable to use continuous carbon fibers in the range of 200 to 1000 GPa; from the viewpoint of the operability of the prepreg blank, it is more preferable to use continuous carbon fibers in the range of 280 to 900 GPa. When the tensile modulus of the carbon fibers is less than 200 GPa, the rigidity of the sandwich structure is inconsistent; when it is greater than 1000 GPa, it is necessary to improve the crystallinity of the carbon fibers, making it difficult to manufacture the carbon fibers. When the tensile modulus of the carbon fibers is within the above range, it is preferable from the perspective of further improving the rigidity of the sandwich structure and improving the manufacturability of the carbon fibers. It should be noted that the tensile modulus of the carbon fibers can be determined by the wire harness tensile test described in JIS R7301 (1986).

[0044] In particular, the tensile modulus of the continuous carbon fibers used in the prepreg blank constituting the outermost layer is preferably 400 to 1000 GPa from the viewpoint of the rigidity of the laminate 20, and even more preferably in the range of 500 to 900 GPa.

[0045] For continuous carbon fibers, in the case of polyacrylonitrile (PAN) based carbon fibers, the preferred density is 1.6 g / cm³. 3 Above 2.0g / cm 3 From the perspective of improving rigidity, 1.8 g / cm² is preferred. 3 Above 2.0g / cm 3 In the case of pitch-based carbon fibers, 2.0 g / cm³ is preferred. 3 Above 2.5g / cm 3 From a cost perspective, 2.0 g / cm³ is further preferred. 3 The above 2.3g / cm3 the following.

[0046] The density of the continuous carbon fibers used in the first prepreg blank 21, which constitutes the outermost layer of the laminate 20, is preferably 2.0 g / cm³. 3 ~2.5g / cm 3 From a cost perspective, 2.0 g / cm³ is a further preferred value. 3 The above 2.3g / cm 3 The following should be noted: The density of carbon fiber can be determined by the test described in JIS R7603-A (1999).

[0047] The resin used as the prepreg blank is not particularly limited, and either thermoplastic resin or thermosetting resin can be used. In the case of thermoplastic resin, for example, a resin of the same type as the thermoplastic resin used in the core layer described later can be used. As thermosetting resin, unsaturated polyester resin, vinyl ester resin, epoxy resin, phenolic (Resol type) resin, urea-formaldehyde melamine resin, polyimide resin, maleimide resin, benzoxazine resin, and other thermosetting resins are preferred. Resins obtained by blending two or more of these can also be used. Among these, epoxy resin is particularly preferred from the viewpoint of the mechanical properties and heat resistance of the molded article. For epoxy resin, in order to exhibit its excellent mechanical properties, it is preferable to contain it as the main component of the resin used. If the substance formed by combining epoxy resin with other components is used as a resin composition, specifically, it is preferable to contain 30% by mass or more relative to the resin composition.

[0048] From the viewpoint of formability and flexural properties of the laminate 20, the weight percentage of continuous carbon fibers in the prepreg is preferably 30-70% by mass. If it is less than 30% by mass, the laminate 20 may sometimes have difficulty exhibiting flexural strength. If it exceeds 70% by mass, insufficient resin may sometimes impair the designability after molding. Preferably, it is 62-68% by mass.

[0049] Regarding the thickness of the prepreg blank, from the viewpoint of the thickness of the laminate 20, it is preferably 0.05 to 1.00 mm. More preferably, from the viewpoint of design flexibility, it is preferably 0.05 to 0.20 mm. When the thickness of the prepreg blank is less than 0.05 mm, operation sometimes becomes difficult.

[0050] In this invention, from the viewpoint of reducing the weight and increasing the rigidity of the laminate 20, it is preferable to have the following properties: Figure 3 The prepreg blank shown is arranged on both sides of the core layer to form a sandwich structure.

[0051] By having such a core layer, it is possible to obtain a lighter and more rigid laminate.

[0052] As the core layer, the foamed molded body 40 or the porous substrate 50 is preferred. Preferably, the foamed molded body 40 is composed of foamed resin, and the porous substrate 50 is a substrate composed of discontinuous fibers and thermoplastic resin.

[0053] The type of resin used when the foamed molded body 40 is used in the core layer can be either the thermosetting resin or the thermoplastic resin described above. 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, or polymethacrylamide resin are preferred. Specifically, to ensure lightweight properties, resins with an apparent density lower than that of the prepreg preform are preferred, and polyurethane resin, acrylic resin, polyethylene resin, polypropylene resin, polyetherimide resin, or polymethacrylamide resin are particularly preferred. Regarding the example resin types, impact resistance improvers such as elastomers or rubber components, other fillers, and additives may be included without prejudice to the purpose of this invention. Examples of these include inorganic fillers, flame retardants, conductivity enhancers, nucleating agents, UV absorbers, antioxidants, vibration dampers, antibacterial agents, insect repellents, deodorizers, anti-coloring agents, heat stabilizers, mold release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, foam control agents, or coupling agents.

[0054] In this invention, the larger the value of the thermal conductivity ratio λ21 / λ1A between the foamed molded body 40 and the prepreg blank in the core layer, the more heat is conducted in the thickness direction and the less heat is conducted in the in-plane direction. Therefore, the smaller the value of λ21 / λ1A, the more heat is conducted in the in-plane direction, and thus, when used as an electronic device housing, it is less susceptible to the effects of localized heating. Therefore, from the viewpoints of lightweight, rigidity, and heat dissipation, the value of λ21 / λ1A is preferably greater than 0 and less than 0.05, and from the viewpoint of heat dissipation, it is further preferred to be greater than 0 and less than 0.01.

[0055] The thermal conductivity λ21 [W / (m·K)] of the foamed body 40 used in the core layer is preferably greater than 0 W / (m·K) and less than 10 W / (m·K). If it exceeds 10 W / (m·K), the generated heat will be transferred to the inside / outside, which may affect internal components or cause burns during use. It is preferably greater than 0 W / (m·K) and less than 5 W / (m·K), and more preferably greater than 0 W / (m·K) and less than 1 W / (m·K). It should be noted that the thermal conductivity of the foamed body 40 can be determined by the test described in JIS H7903 (2008).

[0056] Furthermore, regarding the porous substrate 50 used as the core layer, it is preferable to use a substrate formed by expanding a precursor containing discontinuous fibers and thermoplastic resin along the thickness direction through springback caused by heating, thereby creating voids. The molded body containing the discontinuous fibers and thermoplastic resin constituting the core layer is heated and pressurized to above the softening or melting point of the resin, and then the pressure is released. Utilizing the restoring force of the residual stress in the discontinuous fibers as they tend to return to their original state—the so-called springback—it expands, thereby forming the desired voids within the core layer. During this restoring process, if the restoring effect is suppressed in a certain area using a certain pressurization method, the porosity can be kept low.

[0057] The carbon fibers used in the core layer are preferably polyacrylonitrile (PAN)-based carbon fibers, rayon-based carbon fibers, lignin-based carbon fibers, pitch-based carbon fibers, etc. (including graphite fibers). Among them, in this invention, polyacrylonitrile (PAN)-based carbon fibers with excellent production efficiency are preferred.

[0058] In this invention, for the same reason as the ratio λ21 / λ1A of the thermal conductivity of the foamed molded body 40 to the thermal conductivity of the prepreg blank described above, the value of the ratio λ22 / λ1A of the thermal conductivity of the porous substrate 50 to the prepreg blank when the core layer is used is preferably greater than 0 and less than 1.0. From the viewpoint of lightweight and rigidity, it is more preferably greater than 0 and less than 0.5. From the viewpoint of heat dissipation, it is even more preferably greater than 0 and less than 0.1.

[0059] The value of 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, and may affect internal components or cause burns during use. It is preferably 0.1 W / (m·K) to 10 W / (m·K), and more preferably 3 W / (m·K) to 8 W / (m·K). It should be noted that the thermal conductivity in the fiber direction of the carbon fiber can be determined by the test described in JIS A1412-2 (1999).

[0060] The preferred weight percentage of discontinuous fibers constituting the core layer is 5-75% by weight, and the weight percentage of thermoplastic resin is 25-95% by weight.

[0061] In the formation of the core layer, the ratio of discontinuous fibers to thermoplastic resin is a key factor in determining the porosity. There are no particular limitations on how to determine this ratio; for example, it can be determined by removing the resin components from the core layer and measuring the weight of the remaining discontinuous fibers. Examples of methods for removing the resin components from the core layer include dissolution and ashing. The weight can be measured using an electronic scale or balance. The molded material to be measured can be 100mm × 100mm square, with n = 3 measurements taken, and the average value used.

[0062] Regarding the proportions of the core layer, it is preferable that the discontinuous fiber content is 7-70% by mass and the thermoplastic resin content is 30-93% by mass; more preferably, it is 20-50% by mass and the thermoplastic resin content is 50-80% by mass; and even more preferably, it is 25-40% by mass and the thermoplastic resin content is 60-75% by mass. If the discontinuous fiber content is less than 5% by mass and the thermoplastic resin content is more than 95% by mass, it is difficult to generate resilience, thus making it impossible to increase the porosity. This results in difficulties in creating regions with different porosities within the core layer, consequently reducing the bonding strength with the structure. On the other hand, if the discontinuous fiber content is more than 75% by mass and the thermoplastic resin content is less than 25% by mass, the specific stiffness of the laminate 20 decreases.

[0063] In this 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, voids caused by the resilience of the core layer can be reliably generated. 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 becomes difficult to form voids of a certain size or larger. On the other hand, if the number-average fiber length is greater than 50 mm, it is difficult to randomly disperse them from the fiber bundle, and the core layer cannot generate sufficient resilience. Therefore, the size of the voids is limited, and the bonding strength with the structure decreases.

[0064] As a method for determining the length of discontinuous fibers, there are methods such as directly extracting discontinuous fibers from a group of discontinuous fibers and measuring them using a microscope. When resin adheres to the group of discontinuous fibers, there are methods such as: using a solvent that dissolves only the resin contained in the discontinuous fiber group to dissolve the resin, filtering out the remaining discontinuous fibers, and measuring them using a microscope (dissolution method); in the absence of a solvent to dissolve the resin, simply ashing the resin within a temperature range where the discontinuous fibers do not undergo oxidation loss, separating the discontinuous fibers, and measuring them using a microscope (ashing method); and so on. Forty hundred discontinuous fibers can be randomly selected from a group of discontinuous fibers, and their lengths can be measured using an optical microscope, accurate to 1 μm, to determine the fiber length and its proportion. It should be noted that when comparing methods of directly extracting discontinuous fibers from a group of discontinuous fibers with methods of extracting discontinuous fibers using the ashing method and the dissolution method, the results obtained will not differ significantly by appropriately selecting the conditions. Among these measurement methods, the dissolution method is preferred from the perspective of minimizing weight variation in discontinuous fibers.

[0065] This type of felt, suitable for use in a porous core layer or molded body (formed by impregnating discontinuous fibers with thermoplastic resin), is manufactured by pre-forming discontinuous fibers into fiber bundles and / or dispersing them into monofilaments. Specifically, methods for manufacturing discontinuous fiber felts include: dry processes such as airflow web formation using an airflow to disperse and sheet the discontinuous fibers, and carding processes where discontinuous fibers are mechanically combed and formed into sheets; and wet processes based on the Radright process, which involves stirring discontinuous fibers in water and then papermaking.

[0066] As a means to make discontinuous fibers closer to monofilaments, in dry processes, examples include setting up a fiber-opening bar, further vibrating the fiber-opening bar, making the carding machine's pores finer (ultra-fine state), and adjusting the carding machine's rotation speed. In wet processes, examples include adjusting the stirring conditions of discontinuous fibers, diluting the concentration of reinforcing fibers in the dispersion, adjusting the viscosity of the dispersion, and suppressing eddies when transferring the dispersion.

[0067] In particular, discontinuous fiber mats are preferably manufactured using a wet process. By increasing the concentration of the added fibers or adjusting the flow rate of the dispersion and the speed of the mesh belt conveyor, the proportion of reinforcing fibers in the discontinuous fiber mat can be easily adjusted. For example, by slowing down the speed of the mesh belt conveyor relative to the flow rate of the dispersion, the orientation of the fibers in the resulting mat formed from discontinuous fibers is less likely to be in the pulling direction, thus producing a fluffy mat formed from discontinuous fibers. The mat formed from discontinuous fibers can be composed of discontinuous fiber monomers, or it can be a mixture of discontinuous fibers with a powder-shaped or fiber-shaped matrix resin component, or a mixture of discontinuous fibers with organic or inorganic compounds, or the discontinuous reinforcing fibers can be interlocked with a resin component.

[0068] There is no particular limitation on the type of thermoplastic resin used in the core layer, and any resin from the following examples of thermoplastic resins may be used. Examples of thermoplastic resins selected from the following include: polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polypropylene terephthalate (PTT) resin, polyethylene naphthalate (PEN) resin, liquid crystal polyester resin, polyethylene resin, polyethylene (PE) resin, polypropylene (PP) resin, polybutylene resin, polyolefin resin, polyoxymethylene (POM) resin, polyamide (PA) resin, polyphenylene sulfide (PPS) resin, polyarylene sulfide resin, polyketone (PK) resin, polyetherketone (PEK) resin, polyetheretherketone (PEEK) resin, polyetherketoneketone (PEKK) resin, polyethernitrile (PEN) resin, polytetrafluoroethylene resin, and other fluorinated resins, liquid crystal polymers (LC... Crystalline resins such as poly(phenylene oxide) (P), styrene-based resins, and amorphous resins such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polyphenylene ether (PPE), polyimide (PI), polyamide-imide (PAI), polyether-imide (PEI), polysulfone (PSU), polyethersulfone, and polyarylate (PAR), as well as phenolic resins, phenoxy resins, polystyrene-based resins, polyolefin-based resins, polyurethane-based resins, polyester-based elastomer resins, polyamide-based elastomer resins, polybutadiene-based resins, polyisoprene-based resins, fluoropolymer elastomer resins, and acrylonitrile-based elastomer resins, and their copolymers and modified forms, etc. From the viewpoint of lightweighting of the resulting molded article, polyolefin resin is preferred; from the viewpoint of strength, polyamide resin is preferred; from the viewpoint of surface appearance, amorphous resins such as polycarbonate resin, styrene-based resin, and modified polyphenylene ether resin are preferred; from the viewpoint of heat resistance, polyarylene sulfide resin is preferred; and from the viewpoint of continuous operating temperature, polyether ether ketone resin is preferred.

[0069] The example thermoplastic resin may contain impact-enhancing agents such as elastomers or rubber components, other fillers, and additives, without prejudice to the purpose of this invention. Examples of these include inorganic fillers, flame retardants, conductivity-improving agents, nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorizing agents, anti-coloring agents, heat stabilizers, mold release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, defoaming agents, or coupling agents.

[0070] In this invention, the laminate 20 is obtained by laminating at least two layers of a prepreg blank comprising at least continuous fibers and thermoplastic or thermosetting resin, and the total thickness is preferably 0.3 mm to 2.0 mm. If it is thinner than 0.3 mm, the rigidity of the integral molded body 10 is insufficient, and the difference in thermal conductivity in the thickness / in-plane direction becomes smaller, which may impair heat dissipation. If it is thicker than 2.0 mm, the lightweight properties may be compromised. From the viewpoints of rigidity, heat dissipation, and lightweight, it is more preferable to have a thickness of 0.7 mm to 1.5 mm.

[0071] In addition, regarding the laminate 20 with a porous substrate as the core layer, it can be as follows: Figure 6 In this way, a stepped portion is formed along the in-plane direction within the aforementioned total thickness range, consisting of a first flat prepreg region 21a, an inclined prepreg region 21b, and a second flat prepreg region 21c. Preferably, the prepreg region 21b has an inclined surface of 10° to 90° relative to the in-plane direction of the first flat prepreg region 21a provided in the laminate 20. By providing a stepped portion, a bonding surface 31 with the laminate can be provided in the second flat prepreg region 21c. As a result, the length 32 in the thickness direction of the bonding portion with the laminate 20 can be increased without changing the thickness of the structure. From the viewpoint of improving flowability during injection molding, it is possible to achieve improved bonding strength and thinner wall of the integral molded body 10.

[0072] 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°.

[0073] In this invention, the resin used as the structure 30 is not particularly limited, and the aforementioned thermoplastic resin or thermosetting resin can be used. Thermoplastic resin is preferred, as a fused-bonded structure formed by melting and bonding the thermoplastic resin of the structure 30 to the thermoplastic resin substrate 70 allows for higher bond strength in the integrally molded body 10. A fused-bonded structure refers to a structure in which the components are melted by heat and bonded by cooling. From the viewpoint of heat resistance and chemical resistance, PPS resin is more preferred; from the viewpoint of appearance and dimensional stability of the molded article, polycarbonate resin or styrene-based resin is more preferred; and from the viewpoint of strength and impact resistance of the molded article, polyamide resin is more preferred.

[0074] Furthermore, to achieve high strength and high rigidity in the integral molded body 10, resin containing reinforcing fibers is preferably used as the material for the structure 30. Examples of reinforcing fibers include, for instance, metal fibers such as aluminum fibers, brass fibers, and stainless steel fibers; inorganic fibers such as carbon fibers (polyacrylonitrile, rayon, lignin, and pitch-based fibers), graphite fibers, glass fibers, silicon carbide fibers, and silicon nitride fibers; and organic fibers such as aramid fibers, poly(p-phenylenebenzobisoxazole) (PBO) fibers, polyphenylene sulfide fibers, polyester fibers, acrylic fibers, nylon fibers, and polyethylene fibers. These reinforcing fibers can be used individually or in combination of two or more. From a strength perspective, carbon fibers and glass fibers are preferred. Glass fibers are more preferred, as by using glass fibers as the reinforcing fibers of the structure 30, the structure can be given the function of a radio wave transmission component.

[0075] Furthermore, the resin constituting structure 30 may contain other fillers and additives, depending on the desired properties, without compromising the purpose of the invention. Examples include inorganic fillers, flame retardants other than phosphorus-based agents, conductivity enhancers, nucleating agents, ultraviolet absorbers, antioxidants, vibration damping agents, antibacterial agents, insect repellents, deodorizing agents, anti-coloring agents, heat stabilizers, mold release agents, antistatic agents, plasticizers, lubricants, colorants, pigments, dyes, foaming agents, foam control agents, coupling agents, etc.

[0076] Regarding the weight fiber content of the reinforcing fiber, a discontinuous fiber content of 1 to 60% by mass is preferred. This improves the bonding strength and reduces the warpage of the integral molded body 10. If it is less than 1% by mass, it becomes difficult to ensure the strength of the integral molded body 10; if it exceeds 60% by mass, during injection molding, a portion of the filling of the structure 30 becomes insufficient. From the viewpoint of the formability of the structure, 5 to 55% by mass is preferred, more preferably 8 to 50% by mass, and even more preferably 12 to 45% by mass.

[0077] In this invention, regarding the laminate 20 having a core layer, from the viewpoint of the bonding strength of the integral molded body 10, it is preferable to make it having an insert portion (a part of the structure 30 entering the laminate 20).

[0078] If the structure 30 is formed by injection molding, the structure 30 is bonded to the planar or side portion of the prepreg blank of the laminate 20, and the structure 30 enters a portion of the core layer from the side portion 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 an easy structure for the molten structure 30 to enter. Furthermore, by using a porous substrate formed of discontinuous fibers and thermoplastic resin in the core layer, the bonding strength can be further improved through the anchoring effect of the structure 30 entering the core layer.

[0079] In addition, in the composition of structure 30, such as Figure 7 As shown, before injecting the resin component, a resin frame, which serves as another component, is pre-set on the outer periphery of the laminate 20, and the resin component is injection molded. This is also an effective means of achieving low warpage of the integral molded body 10.

[0080] From the viewpoint of strength and rigidity of the integral molded body 10, the resin frame 80 is preferably a fiber-reinforced resin frame formed of reinforcing fibers and resin. The reinforcing fibers can be those used in the resin components described above. In this invention, from the viewpoint of increasing the strength of the resin frame 80, glass fiber and carbon fiber are preferred. From the viewpoint of antenna performance, glass fiber is preferred as the reinforcing fiber. While carbon fiber is inferior to glass fiber in terms of antenna performance when used as the reinforcing fiber, it is still an effective means to improve strength and rigidity.

[0081] In this invention, from the viewpoint of thinning the wall of the laminate 20 and cost, the prepreg blank constituting the laminate may also be composed of a prepreg blank containing dissimilar carbon fibers. In the dissimilar carbon fiber prepreg blank, the continuous carbon fibers constituting the prepreg blank other than the first prepreg blank 21 contain carbon fibers of a different type than the continuous carbon fibers constituting the first prepreg blank 21. Figure 2An example of a laminate 20 is shown, in which a first prepreg blank 21 and a second prepreg blank 22, which is a dissimilar carbon fiber prepreg blank, are alternately laminated. Furthermore, considering the potential for heat transfer to the interior / exterior when used as an electronic device housing, which could affect internal components or cause burns during use, the ratio λ1B / λ1A of the thermal conductivity λ1B of the carbon fiber with the lowest thermal conductivity to the thermal conductivity λ1A of the first prepreg blank 21 is preferably greater than 0 and less than 1.0. From the viewpoint of lightweight and rigidity, it 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, and more preferably 3 W / (m·K) or more and 8 W / (m·K) or less. It should be noted that the thermal conductivity of carbon fiber in the fiber direction can be determined by the test described in JIS A1412-2 (1999).

[0082] In this invention, a continuous fiber fabric substrate 60 can be disposed on the outermost side of at least one of the outermost layers of the laminate 20 as a design surface. By configuring the fabric pattern on the design surface side, a highly customizable article can be obtained. Furthermore, it is preferable to manufacture a structure in which the number of layers of the prepreg blank constituting the laminate 20, the type of carbon fiber, and the type of resin are appropriately combined according to the characteristics and cost required for the integral molded body 10.

[0083] The continuous fiber fabric substrate 60 is described below. The continuous fiber fabric substrate refers to a substrate formed by bundling continuous fibers in units of 1000 strands, using these bundles as warp and weft yarns, and then using a loom to cross the two sets of yarns at right angles. Typically, a continuous fiber bundle of 1000 strands is called 1K, 3000 strands is called 3K, and 12000 strands is called 12K.

[0084] The fibers used in the continuous fiber fabric substrate 60 include metal fibers such as aluminum fiber, brass fiber, and stainless steel fiber; glass fiber; polyacrylonitrile-based, rayon-based, lignin-based, and pitch-based carbon fibers; graphite fiber; aromatic polyamide fiber; polyaramid fiber; PBO fiber; polyphenylene sulfide fiber; polyester fiber; acrylic fiber; nylon fiber; polyethylene fiber; and other organic fibers, as well as silicon carbide fiber, silicon nitride fiber, alumina fiber, silicon carbide fiber, and boron fiber. These fibers can be used alone or in combination of two or more. These fiber raw materials can also be surface-treated. Examples of surface treatments include metal coating treatment, coupling agent-based treatment, sizing agent-based treatment, and additive attachment treatment.

[0085] When carbon fiber is used as the continuous fiber fabric substrate 60, from the viewpoint of lightweighting, it is preferable to use carbon fibers (including graphite fibers) such as polyacrylonitrile (PAN) carbon fibers, rayon carbon fibers, lignin carbon fibers, and pitch-based carbon fibers, which have excellent specific strength and specific stiffness. Among them, PAN-based carbon fibers with excellent processability are preferred.

[0086] Regarding the continuous fiber fabric substrate 60, the continuous fibers are preferably selected from at least one of plain weave, twill weave, satin weave, and shoji weave. Since the continuous fiber fabric substrate 60 has a distinctive fiber pattern, this distinctive pattern can be highlighted. By using the continuous fiber fabric substrate 60 on the outermost layer (design surface side), the shape and pattern of the continuous fiber fabric can be made more prominent, resulting in a novel surface pattern. Regarding the continuous fiber bundle, 1K to 24K is preferred, and from the viewpoint of the stability of the fiber pattern during processing, 1K to 6K is further preferred.

[0087] In this invention, for example, such as Figure 5 As shown, a thermoplastic resin layer can be provided by distributing a thermoplastic resin substrate 70 between the prepreg blank and the structure, or / and between the core layer and the structure.

[0088] Here, the thermoplastic resin substrate 70 can be made of acrylic, epoxy, styrene, nylon, ester-based adhesives, thermoplastic resin films, nonwoven fabrics, etc. Furthermore, regarding the material, making it the same material as the structure can improve the bonding strength. It is acceptable if the resin of the outermost layer of the prepreg or core layer is not the same resin as the adhesive used in the thermoplastic resin substrate 70, as long as there is good compatibility; there are no particular limitations, but it is preferable to select the most suitable resin based on the type of resin constituting the structure.

[0089] In this invention, regarding the laminate 20 using the porous substrate 50, from the viewpoint of the rigidity and thin-walledness of the integrally molded body 10, it is preferable to use as follows: Figure 6 , Figure 7 As shown in the cross-sectional view, the porosity of the porous substrate is lower in the inclined porous substrate region 50b and the porous substrate region 50c in the second flat portion compared to the porous substrate region 50a in the first flat portion.

[0090] Example

[0091] The integrated molded body 10 and its manufacturing method of the present invention will be specifically described below through examples, but the following examples do not limit the present invention.

[0092] (1) Heat dissipation of the integral molded body 10

[0093] The heat dissipation performance evaluation used a micro-ceramic heater (model: MC1010) manufactured by Sakaguchi Electric Heating Co., Ltd. Figure 1 The integral molded body 10 shown is placed with a heater (not shown) heated to 40°C and stabilized at the center of the designed surface side of the integral molded body 10 in contact with the body. The heater is immediately turned off, and the body is left in this state for 10 minutes. Then, with the heater removed, the areas with the highest temperatures on both the designed and non-designed surfaces are identified using a thermal imager, and the maximum temperatures are measured. Furthermore, the obtained maximum surface temperatures are evaluated as A, B, and C according to the following criteria. The measurement on the designed surface side is defined as heat dissipation performance X, and the measurement on the non-designed surface side is defined as heat dissipation performance Y. A heat dissipation performance X and heat dissipation performance Y both being A or B are considered acceptable; otherwise, they are considered unacceptable.

[0094] A: Maximum temperature less than 25℃

[0095] B: Maximum temperature is above 25℃ and below 30℃

[0096] C: Maximum temperature above 30℃

[0097] (2) Lightweight of laminate 20

[0098] A sample with a width of 100 mm and a length of 100 mm (thickness equal to the thickness of the laminate 20) is cut from the laminate 20. The specific gravity is calculated using the following formula based on its mass W and apparent volume V.

[0099] Specific gravity = W / V

[0100] In addition, this specific gravity value is compared with that of magnesium (AZ91, specific gravity 1.82), which is a metallic material. If it is lighter, it is considered acceptable; otherwise, it is considered unacceptable.

[0101] (Material Composition Example 1-1) Unidirectional Prepreg Blank (C-1) 21

[0102] As a bitumen-based prepreg blank, a unidirectional prepreg blank (C-1)21 (manufactured by Nippon Graphite Fiber Corporation as "GRANOC Prepreg" (registered trademark), E8026A-07S) was used, with a fiber-direction thermal conductivity of 320 W / (m·K), a tensile modulus of elasticity of 785 GPa, and a fiber density of 2.17 g / m³. 3 (Prepreg blank formed from pitch-based continuous carbon fibers and resin).

[0103] (Material Composition Example 1-2) Unidirectional Prepreg Blank (C-2) 21

[0104] As a PAN-based prepreg preform, unidirectional prepreg preform (C-2)21 (manufactured by Toray Corporation, "ToraycaPrepreg" (registered trademark), variety P3252S-10) was used, with a fiber-direction thermal conductivity of 5 W / (m·K), tensile modulus of elasticity of 230 GPa, and fiber density of 1.8 g / m³. 3 (Prepreg blank formed from PAN-based continuous carbon fibers and resin).

[0105] (Material Composition Example 2) Foamed Molded Body 40

[0106] Uses uncrosslinked low-foaming polypropylene sheet "EFCELL" (registered trademark) (2x foaming) (manufactured by Furukawa Electric Industries, Ltd.).

[0107] (Material Composition Example 3) Short-cut carbon fiber bundles

[0108] Using a wallpaper knife (cartridge cutter), PAN-based carbon fiber (Toray Co., Ltd.'s "Torayca filament" (registered trademark), variety T700SC, carbon fiber with a thermal conductivity of 10 W / (m·K) in the fiber direction) was cut to obtain short carbon fiber bundles with a fiber length of 6 mm.

[0109] (Material Composition Example 4) Carbon Fiber Felt

[0110] A pre-foamed dispersion was prepared by stirring 100 liters of a 1.5 wt% aqueous solution of a surfactant (sodium n-dodecylbenzenesulfonate, manufactured by Wako Pure Chemical Industries, Ltd.). Short-cut carbon fiber bundles obtained in Material Composition Example 3 were added to this dispersion, stirred, and then fed into a paper machine with a papermaking surface of 400 mm in length and 400 mm in width. After dehydration by suction, the mixture was dried at 150°C for 2 hours to obtain carbon fiber felt. The obtained felt exhibited good dispersion.

[0111] (Material Composition Example 5) Polypropylene Resin Film

[0112] A polypropylene resin film was obtained by dry blending 90% by mass of unmodified polypropylene resin (PRIME PORYMER Co., Ltd., "PrimePolypro" (registered trademark) J105G, melting point 160°C) and 10% by mass of acid-modified polypropylene resin (Mitsui Chemicals Co., Ltd., "ADMER" (registered trademark) QE510, melting point 160°C).

[0113] (Material Composition Example 6) Porous Substrate 50

[0114] Using material composition examples 4 and 5, the layers are stacked in the order of [polypropylene resin film / carbon fiber felt / polypropylene resin film].

[0115] (Material Composition Example 7) Glass Fiber Reinforced Polycarbonate

[0116] Composite granules made of glass fiber reinforced polycarbonate (“Panlite” (registered trademark) GXV-3545WI (Teijin Kasei Corporation)).

[0117] (Material Composition Example 8) Thermoplastic Resin Substrate 70

[0118] A polyester resin film with a thickness of 0.05 mm was obtained using a polyester elastomer resin ("Hytrel" manufactured by Toray DuPont Co., Ltd., a registered trademark). This film was used as a thermoplastic resin substrate 70.

[0119] (Example 1)

[0120] In production Figure 1 When the integrated molded body 10 shown is used, the unidirectional prepreg blank (C-1) 21 prepared in Material Composition Example 1-1, the foamed molded body 40 prepared in Material Composition Example 2, and the thermoplastic resin substrate 70 prepared in Material Composition Example 8 are each adjusted to 400mm×400mm, and then laminated in the order of [unidirectional prepreg blank (C-1) 21 0° / unidirectional prepreg blank (C-1) 21 90° / foamed molded body 40 / unidirectional prepreg blank (C-1) 21 90° / unidirectional prepreg blank (C-1) 21 0° / thermoplastic resin substrate 70], and pressurized in a flat mold heated to 150°C at 3MPa×5 minutes to obtain the laminated body 20.

[0121] Next, the obtained laminate 20 was processed into a size of 300mm × 200mm and placed in an injection mold. Using glass fiber reinforced polycarbonate as described in Material Composition Example 7, injection molding was performed at 150MPa, barrel temperature 320°C, mold temperature 120°C, and resin nozzle diameter Φ3mm to form structure 30, thus manufacturing a [material name missing]. Figure 1 The integral molded body 10 shown is subjected to heat dissipation measurement using the method described above. The results show that both heat dissipation performance X and Y are A, which is a good result and is considered acceptable. The characteristics of the integral molded body 10 are summarized in Table 1.

[0122] (Example 2)

[0123] Using the unidirectional prepreg blank (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 adjusted to 400mm × 400mm, they were stacked in the order of [unidirectional prepreg blank (C-1) 21 0° / unidirectional prepreg blank (C-1) 21 90° / porous substrate 50 / unidirectional prepreg blank (C-1) 21 90° / unidirectional prepreg blank (C-1) 21 0° / thermoplastic resin substrate 70]. They were then pressurized in a flat mold heated to 180°C at 3MPa × 5 minutes, and then the mold spacing was expanded to 1.15mm, and pressurized at 3MPa × 3 minutes. The porous substrate 50 expanded in the thickness direction due to its springback, forming voids. Then, using a mold with a stepped shape and a surface temperature of 120°C, pressure molding is applied at 3 MPa for 3 minutes, and the laminate 20 is cooled to form a stepped shape. Therefore, in terms of the porosity of the porous substrate, relative to... Figure 6 For the portion corresponding to the porous substrate region 50a of the first flat portion, the porosity of the portion corresponding to the porous substrate region 50b of the inclined portion is reduced, and the porosity of the portion corresponding to the porous substrate region 50c of the second flat portion is even lower.

[0124] The resulting laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation performance of the resulting integral molded body 10 was measured using the method described above. The results showed that both heat dissipation performance X and heat dissipation performance Y were A, indicating a satisfactory result. The characteristics of the integral molded body 10 are summarized in Table 1.

[0125] (Example 3)

[0126] Using the unidirectional prepreg blank (C-1) 21 prepared in Material Composition Example 1-1, the unidirectional prepreg blank (C-2) 21 prepared in Material Composition Example 1-2, and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each adjusted to 400mm × 400mm, they were stacked in the order of [unidirectional prepreg blank (C-1) 21 0° / unidirectional prepreg blank (C-2) 21 90° / unidirectional prepreg blank (C-2) 21 0° / unidirectional prepreg blank (C-2) 21 90° / unidirectional prepreg blank (C-1) 21 0° / thermoplastic resin substrate 70], and pressurized in a flat mold heated to 150°C at 3MPa × 5 minutes to obtain the laminate 20.

[0127] Next, the resulting laminate 20 was processed to a size of 300mm × 200mm and then placed in an injection mold under the same conditions as in Example 1. The heat dissipation performance of the resulting integral molded body 10 was measured using the method described above. The results showed that both heat dissipation performance X and heat dissipation performance Y were A, indicating a satisfactory result. The characteristics of the integral molded body 10 are summarized in Table 1.

[0128] (Example 4)

[0129] Using the unidirectional prepreg blank (C-1) 21 prepared in Material Composition Example 1-1 and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each adjusted to 400mm×400mm, they were stacked in the order of [unidirectional prepreg blank (C-1) 21 0° / unidirectional prepreg blank (C-1) 21 90° / unidirectional prepreg blank (C-1) 21 0° / unidirectional prepreg blank (C-1) 21 90° / unidirectional prepreg blank (C-1) 21 0° / thermoplastic resin substrate 70], and pressurized in a flat mold heated to 150°C at 3MPa×5 minutes to obtain the laminate 20.

[0130] The resulting laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation performance of the resulting integral molded body 10 was measured using the method described above. The results showed that both heat dissipation performance X and heat dissipation performance Y were B, indicating a satisfactory result. The characteristics of the integral molded body 10 are summarized in Table 1.

[0131] (Comparative Example 1)

[0132] Using the unidirectional prepreg blank (C-2) 21 prepared in Material Composition Examples 1-2 and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each adjusted to 400mm×400mm, they were stacked in the order of [unidirectional prepreg blank (C-2) 21 0° / unidirectional prepreg blank (C-2) 21 90° / unidirectional prepreg blank (C-2) 21 0° / unidirectional prepreg blank (C-2) 21 90° / unidirectional prepreg blank (C-2) 21 0° / thermoplastic resin substrate 70], and pressurized in a flat mold heated to 150°C at 3MPa×5 minutes to obtain the laminate 20.

[0133] The resulting laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation performance of the resulting integral molded body 10 was measured using the method described above. The results showed that heat dissipation performance X was C and heat dissipation performance Y was B, indicating an overall unacceptable result. The characteristics of the integral molded body 10 are summarized in Table 1.

[0134] (Comparative Example 2)

[0135] Using the unidirectional prepreg blank (C-2) 21 prepared in Material Composition Examples 1-2, the foamed molded body 40 prepared in Material Composition Example 2, and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, each adjusted to 400mm×400mm, they were stacked in the order of [unidirectional prepreg blank (C-2) 21 0° / unidirectional prepreg blank (C-2) 21 90° / foamed molded body 40 / unidirectional prepreg blank (C-2) 21 90° / unidirectional prepreg blank (C-2) 21 0° / thermoplastic resin substrate 70]. The laminated body 20 was obtained by pressing in a flat mold heated to 150°C at 3MPa for 5 minutes.

[0136] The resulting laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation performance of the resulting integral molded body 10 was measured using the method described above. The results showed that heat dissipation performance X was C and heat dissipation performance Y was B, indicating an overall unacceptable result. The characteristics of the integral molded body 10 are summarized in Table 1.

[0137] (Comparative Example 3)

[0138] Using the unidirectional prepreg blank (C-1) 21 prepared in Material Composition Example 1-1, the unidirectional prepreg blank (C-2) 21 prepared in Material Composition Example 1-2, and the thermoplastic resin substrate 70 prepared in Material Composition Example 8, after adjusting each to 400mm×400mm, they were stacked in the order of [unidirectional prepreg blank (C-2) 21 0° / unidirectional prepreg blank (C-1) 21 90° / unidirectional prepreg blank (C-1) 21 0° / unidirectional prepreg blank (C-1) 21 90° / unidirectional prepreg blank (C-2) 21 0° / thermoplastic resin substrate 70], and pressurized in a flat mold heated to 150°C at 3MPa×5 minutes to obtain the laminate 20.

[0139] The resulting laminate 20 was injection molded under the same conditions as in Example 1, and the heat dissipation performance of the resulting integral molded body 10 was measured using the method described above. The results showed that heat dissipation performance X was C and heat dissipation performance Y was B, indicating an overall unacceptable result. The characteristics of the integral molded body 10 are summarized in Table 1.

[0140] [Table 1]

[0141]

[0142] Industrial availability

[0143] The integrated molded body 10 of the present invention can be effectively used in automotive interior and exterior decoration, electrical and electronic equipment housings, bicycles, structural materials for sporting goods, aircraft interior decoration materials, and transport boxes, etc.

[0144] Explanation of reference numerals in the attached figures

[0145] 10 Integrated Molded Body

[0146] 20-layer stack

[0147] 21 First Prepreg Billet

[0148] 21a Prepreg blank area of ​​the first flat section

[0149] 21b Prepreg blank area of ​​inclined section

[0150] 21c Prepreg blank area of ​​the second flat section

[0151] 22 Second Prepreg Billet

[0152] 30 Structures

[0153] 31. Joint surface with the laminate

[0154] 32 Length in the thickness direction of the joint with the laminated body

[0155] 40 Foamed Molded Body

[0156] 50 Porous substrates

[0157] 50a Porous substrate region of the first flat section

[0158] Porous substrate area of ​​50b inclined section

[0159] 50c Porous substrate region of the second flat part

[0160] 60 Continuous fiber fabric substrate

[0161] 70 Thermoplastic resin substrate

[0162] 80 Resin Frame

Claims

1. An integrally molded body, comprising a structure formed of thermoplastic resin and reinforcing fibers disposed on the outer periphery of a laminate consisting of at least a prepreg blank formed of continuous carbon fibers and resin, wherein the thermal conductivity λ1A in the fiber direction of the continuous carbon fibers of the first prepreg blank constituting the outermost layer of the laminate is 100 [W / (m·K)] or more and 800 [W / (m·K)] or less. The integral molded body satisfies the following (i) and / or (ii). (i) The laminate is a sandwich structure consisting of a core layer and a prepreg blank, with the prepreg blank disposed on both sides of the core layer, satisfying (i-1) or (i-2) below. (i-1) The core layer is a foamed molded body formed of foamed resin, wherein the ratio of the thermal conductivity λ21 to the thermal conductivity λ1A of the foamed molded body, λ21 / λ1A, is greater than 0 and less than 0.

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

5. (ii) The prepreg blank constituting the laminate includes a dissimilar carbon fiber prepreg blank, wherein the continuous carbon fibers constituting the prepreg blank other than the first prepreg blank are formed of a different type of carbon fiber than the continuous carbon fibers constituting the first prepreg blank, and the ratio of the thermal conductivity λ1B of the carbon fiber with the lowest thermal conductivity in the dissimilar carbon fiber prepreg blank to the thermal conductivity λ1A, λ1B / λ1A, is 0.016 or more and less than 0.

5.

2. The integrally molded body as described in claim 1, wherein, The density of the continuous carbon fibers constituting the first prepreg blank is 2.0 g / cm³. 3 ~2.5g / cm 3 .

3. The integrally molded body as described in claim 1 or 2, wherein, A continuous fiber fabric substrate is disposed on the outermost side of at least one of the outermost layers of the laminate as a design surface.

4. The integrally molded body as described in claim 1 or 2, wherein, A thermoplastic resin substrate is disposed in at least a portion between the laminate and the structure.

5. The integral molded body as described in claim 1 or 2, used as an electronic device housing.

6. An electronic device housing comprising an integrally molded body according to any one of claims 1 to 5.

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