Integrated molded body and method for manufacturing the same

Abstract

An integrated molded body, wherein a resin inner member (B1) comprising a thermoplastic resin is interposed between a resin outer member (C1) comprising a thermoplastic resin and a plate (A) having a single surface as a design surface, and is a rectangular planar structure having a first joint portion where at least a portion of the outer peripheral side surface and / or outer peripheral edge of the plate (A) is joined to the resin inner member (B1), and a second joint portion where at least a portion of the outer peripheral side surface and / or outer peripheral edge of the resin inner member (B1) is joined to the resin outer member (C1), wherein the outer peripheral side surface and / or outer peripheral edge of the plate (A) is joined to the second joint portion. On the side opposite to the design surface (non-design surface side), one or more molten resin confluence lines are formed in each of the resin inner part (B1) and the resin outer part (C1), and one position of the molten resin confluence line (B2) formed in the resin inner part (B1) determined in a direction parallel to the outer periphery of the integrated molded body and the position of the molten resin confluence line (C2) formed in the resin outer part (C1) located closest to the position of the molten resin confluence line (B2) have a positional relationship of being present at a staggered position. Provided are an integrated molded body and a method for manufacturing the same in which a decrease in the strength of a molded body in which a molten resin confluence line is formed in a resin part by injection molding is suppressed.

Description

Technical Field

[0001] The present invention relates to an integrated molded body which can be used as a component or housing portion of a personal computer, OA equipment, mobile phone, etc. and is suitable for applications requiring light weight, high strength, high rigidity and thin wall, and a method for producing the same. Background Art

[0002] At present, with the development of portable electrical and electronic equipment such as personal computers, OA equipment, AV equipment, mobile phones, landlines, fax machines, home appliances, toys, etc., further miniaturization and lightness are required. In order to achieve this requirement, it is necessary to avoid the shell from bending significantly and contacting with internal parts and causing damage when a load is applied to the components (especially the shell) constituting the equipment from the outside. Therefore, thin-walling is also required while achieving high strength and high rigidity. In addition, for the molded structure obtained by integrating the fiber-reinforced resin structure (which contains reinforcing fibers and resin) with other components, such as frame components, the reliability of the bonding strength is required.

[0003] Patent document 1 (International Publication 2018 / 110293) describes an integrated molded body in which a bonding resin (C) is interposed between a plate (A) whose single-side surface is a design surface and a component (B), the integrated molded body having the following structure: a first bonding portion having at least a portion of the outer peripheral edge of the plate (A) bonded to the bonding resin (C), the plate (A) being separated from the component (B), at least a portion of the surface on the design surface side of the integrated molded body having an area where the plate (A), the component (B) and the bonding resin (C) are exposed, and the following effects are disclosed: a plurality of structures are bonded with high bonding strength, and the bonding boundary portion thereof has good smoothness, and even if the molded body has components of the plate, warping can be reduced, thereby achieving lightweight and thin-walled design.

[0004] Patent document 2 (Japanese Patent Gazette No. 2005-1215) records a method for manufacturing injection molded products by manufacturing parts through a multi-point injection molding machine, and the manufacturing method has the following steps: a film loading step, loading a film on one of the movable mold and the fixed mold constituting the molding mold of the multi-point injection molding machine; a first filling step, injecting molten resin into the cavity in the molding mold from a first injection gate provided on the other mold of the movable mold and the fixed mold, and leaving at least a part of the cavity for filling and solidification; a second filling step, after the first filling step, injecting molten resin into the remaining cavity from a second injection gate provided on the other mold in the same manner as the first injection gate, and filling and solidifying, wherein it is disclosed that even in the case of a molded product formed by a multi-point injection molding mechanism, an effect of an injection molded product with no visible weld line can be obtained.

[0005] In addition, in Patent Document 3 (Japanese Patent Publication No. 8-318547), in an injection molding method for injecting molten resin into a mold having a cavity with two runners, an injection molding machine is used in which two injection units are arranged corresponding to the positions of the two runners, and the molten resin is injected into the mold from the two injection units simultaneously or with a time difference, and the molten resin in the cavity is forcibly shaken by setting the injection action and the back suction action of the two injection units to be mutually opposite actions during the period from the injection of the molten resin to the cooling and solidification. Therefore, the orientation of the molten resin is disordered, and the strength of the molded product is uniform at any position. In particular, the following effect is disclosed: when the resin contains reinforcing materials such as glass fiber and carbon fiber, the reinforcing materials are entangled in the confluence of the molten resin and are not unidirectionally oriented, so that the strength of the confluence can be prevented from decreasing.

[0006] In Patent Document 4 (Japanese Patent Application Laid-Open No. 6-210669), a plurality of gates opened in the cavity, a plurality of runners connected to the plurality of gates, and a plurality of flow rate adjustment mechanisms for increasing or decreasing the flow rate per unit time in the plurality of runners at different times are provided in the mold, and the amount of resin flowing from each gate per unit time increases or decreases at different times, so that the position where the plurality of resin flows flowing from the plurality of gates into the cavity merge in the cavity is distributed left and right along a line corresponding to the weld line according to the increase or decrease in the amount of resin flowing from each gate. The result is disclosed as an effect that the weld line that should be generated at the merged portion becomes a thin left-right interlaced line and substantially disappears.

[0007] Patent document 5 (Japanese Patent Publication No. 6-285911) describes a structure having the following mechanisms: a pressure detection mechanism for detecting a situation where the pressure of the injected molten resin at a point closer to the first prescribed position than the third prescribed position exceeds a prescribed value when the molten resin is injected from the first gate and the second gate at the same time, and at a third prescribed position where two streams of molten resin injected from the two gates meet in the resin filling space and form a weld line; and a small space for detecting a situation where the pressure of the injected molten resin at a point closer to the first prescribed position than the third prescribed position exceeds a prescribed value. The molten resin retreats; and a valve mechanism, which usually closes the inlet on the resin filling space side of the small space in advance. When the pressure exceeds a specified value in response to a pressure detection device, the valve mechanism is used to open the inlet, introduce a part of the molten resin into the above-mentioned small space and make it retreat, and discloses the following effects: by operating the opening and closing of the gate, further, by opening the valve to introduce the resin in the vicinity into the small space and make it retreat, so that in the part where the weld line is formed, the pressure of the resin flow on the opposite side becomes relatively high, the front end center of the resin flow flows in, and a concave-convex weld line is formed more deeply, thereby improving the strength of this part.

[0008] Patent document 6 (Japanese Patent Publication No. 2000-167863) describes a method for welding reinforcement of short fiber reinforced thermoplastic resins, which is a method for insert molding a reinforcing component formed of a continuous fiber reinforced thermoplastic resin composite material having certain thermal properties to enhance welding, and discloses the effect of greatly improving the strength of the weld portion without the need for special equipment.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: International Publication No. 2018 / 110293

[0012] Patent Document 2: Japanese Patent Application Publication No. 2005-1215

[0013] Patent Document 3: Japanese Patent Application Laid-Open No. 8-318547

[0014] Patent Document 4: Japanese Patent Application Laid-Open No. 6-210669

[0015] Patent Document 5: Japanese Patent Application Laid-Open No. 6-285911

[0016] Patent document 6: Japanese Patent Application Publication No. 2000-167863. Summary of the invention

[0017] Problems to be solved by the invention

[0018] In the resin filling space (cavity) inside the mold, the resin flow sometimes has to be split. The two or more split resin flows merge and solidify in a state where the merged part is not fully fused with each other, thereby forming a weld line (also called a welded part). The weld line formed by the merged part has a problem that its strength is lower than that of other parts.

[0019] Patent Document 1 describes a method of joining and integrating a plate material and a frame material by injection molding, but does not mention weld lines that are predicted to occur during injection molding, and there is still room for improvement in measures to address this problem.

[0020] In the configuration of Patent Document 2, the amount of filling in the second filling step is only the amount of filling in the first filling step reduced relative to the total amount, so that the so-called mold clamping force can be performed with a more significantly reduced mold clamping force relative to the total amount, and the film can hide the weld line generated at the contact part of the molten resin from the surface, which can improve the surface appearance. However, although the film can obtain the effect of hiding the weld line, there is a problem in suppressing the reduction in the strength of the confluence part of the weld line.

[0021] In addition, in the structure of patent document 3, in the injection molding using a multi-point injection molding machine, the screws 12, 22 of each injection unit 10, 20 are alternately advanced and retreated to forcibly shake the molten resin in the cavity 35, so that the orientation of the molten resin is disordered, which can ensure a certain strength of the molded product. However, due to the repetition of injection action and back-suction action, a control mechanism for alternately advancing and retreating the screws 12, 22 of each injection unit 10, 20 is required. In the case where the molded product has a complex shape and the number of injection gates increases, the mechanism increases the number of injection units, and the control mechanism is complicated, which leads to the problem that the manufacturing process itself becomes complicated.

[0022] In addition, in the structure of patent document 4, an additional flow regulating mechanism is required for adjusting the amount of resin flowing in from the gate per unit time during injection molding, which increases the manufacturing cost. At the same time, the amount of resin flowing in is constantly changing, which may cause uneven flow of resin into the cavity during injection molding, and further cause the problem of generating voids.

[0023] In addition, in the injection molding structure of Patent Document 5, the pressure of the flowing molten resin is adjusted to form a concave-convex weld line more deeply, so a structure is adopted in which a part of the molten resin is introduced into a resin storage part arranged outside the molding part. However, in this structure, it is necessary to ensure an additional space in the mold, and the production of the molding mold becomes complicated, and it is inevitable to increase the size of the mold. In addition, in order to form a weld line more efficiently and deeply, it is necessary to detect the pressure of the molten resin and feed it back to the opening and closing of the valve, and the control of this feedback must also be considered, resulting in a complicated control sequence, and there is a problem that the manufacturing process itself becomes complicated.

[0024] In addition, the structure of Patent Document 6 is a method of insert molding using a reinforcing component and reinforcing the weld line using the reinforcing component. Since another reinforcing component is stacked, the reinforced molded product becomes thicker, which poses a problem in achieving thinning.

[0025] Therefore, in view of the problems of the above-mentioned prior art, the object of the present invention is to provide an integrated molded body and a method for manufacturing the same, which can maintain high joining strength even if weld lines are generated at the confluence of the resin parts when multiple structures are injected with resin parts from multiple injection gates and joined, and can also suppress the decrease in strength of the integrated structure, reduce warping, and achieve lightweight and thin-walled design.

[0026] Means for solving problems

[0027] In order to solve the above problems, the present invention adopts the following means. That is:

[0028] [1] An integrated molded body, characterized in that a resin inner member (B1) comprising a thermoplastic resin is interposed between a resin outer member (C1) comprising a thermoplastic resin and a plate material (A) having a single surface as a design surface, the integrated molded body being a rectangular planar structure having a first joint portion where at least a portion of an outer peripheral side surface and / or an outer peripheral edge portion of the plate material (A) is joined to the resin inner member (B1), and a second joint portion where at least a portion of an outer peripheral side surface and / or an outer peripheral edge portion of the resin inner member (B1) is joined to the resin outer member (C1),

[0029] On the side opposite to the above-mentioned design surface of the above-mentioned plate (A) (non-design surface side), one or more molten resin confluence lines are formed in the above-mentioned resin inner component (B1) and the above-mentioned resin outer component (C1), respectively, and a position of the molten resin confluence line (B2) formed in the above-mentioned resin inner component (B1) determined in a direction parallel to the outer periphery of the above-mentioned integrated molded body and a position of the molten resin confluence line (C2) formed in the above-mentioned resin outer component (C1) located closest to the above-mentioned position of the molten resin confluence line (B2) have a positional relationship of being present at a staggered position.

[0030] [2] An integrated molded body according to [1], wherein the ratio M2 / M1 of the distance M2 (mm) between the molten resin confluence line (B2) and the molten resin confluence line (C2) closest to the molten resin confluence line (B2) relative to the outer circumference M1 (mm) of the integrated molded body is 0.04 to 0.4.

[0031] [3] The integrated molded body according to [1] or [2], wherein the molten resin confluence line (B2) is formed in a narrow width portion (B1') provided at a portion of the resin inner member (B1).

[0032] [4] The integrated molded body according to any one of [1] to [3], wherein the molten resin confluence line (C2) is formed in a narrow width portion (C1') provided at a portion of the resin exterior member (C1).

[0033] [5] The integrated molded body according to any one of [1] to [4], wherein the first joining portion is formed over the entire circumference of the outer peripheral side surface and / or outer peripheral edge of the plate member (A).

[0034] [6] The integrated molded body according to any one of [1] to [5], wherein the second joining portion is formed over the entire circumference of the outer peripheral side surface and / or outer peripheral edge of the resin inner member (B1).

[0035] [7] The integrated molded body according to any one of [1] to [6], wherein the resin inner component (B1) or the resin outer component (C1) contains reinforcing fibers, the reinforcing fibers are discontinuous fibers, and the weight-average fiber length of the discontinuous fibers is 0.3 to 3 mm.

[0036] [8] A method for producing an integrated molded body, characterized in that it is a method for producing an integrated molded body having a planar structure having a rectangular shape by the following steps:

[0037] In a first step, a precursor of a resin outer component (C1) is injected into a molding die from a plurality of resin injection gates (GC) to preform the resin outer component (C1);

[0038] A second step is to arrange the plate (A) inside the resin exterior member (C1) at a position separated from at least a part of the resin exterior member (C1); and

[0039] In the third step, a precursor of the resin inner component (B1) is injected into the gap between the plate (A) and the resin outer component (C1) through a plurality of resin injection gates (GB), thereby forming a first joint portion where at least a portion of the outer peripheral side surface and / or outer peripheral edge of the plate (A) is joined to the resin inner component (B1), and a second joint portion where at least a portion of the outer peripheral side surface and / or outer peripheral edge of the resin inner component (B1) is joined to the resin outer component (C1).

[0040] Among them, the injection conditions of the precursor of the above-mentioned resin inner component (B1) and the precursor of the above-mentioned resin outer component (C1) are adjusted so that when observed from the side opposite to the design surface of the above-mentioned plate (A) (non-design surface side), the position of the molten resin confluence line (B2) formed in the above-mentioned resin inner component (B1) determined along the direction parallel to the outer periphery of the above-mentioned integrated molded body and the position of the molten resin confluence line (C2) formed in the above-mentioned resin outer component (C1) which is located at a position closest to the above-mentioned molten resin confluence line (B2) are offset in at least one place.

[0041] [9] A method for manufacturing an integrated molded body according to [8], wherein the injection conditions are as follows: a position of one of the plurality of resin injection gates (GB) for injecting a precursor of the resin inner component (B1) and a position of the resin injection gate (GC) for injecting a precursor of the resin outer component (C1) which is located at a position closest to the position of the resin injection gate (GB) are arranged at offset positions relative to a direction parallel to the outer periphery of the integrated molded body.

[0042] Effects of the Invention

[0043] According to the integrated molded body and its manufacturing method of the present invention, the integrated molded body obtained by joining multiple structures by injecting resin can be joined with high joining strength. At the same time, the molded body itself also has high strength. Even if the molded body has components of a plate material, warping can be reduced, and light weight and thin-walled can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] [ Figure 1 ] is a three-dimensional diagram of the integrated molded body involved in the present invention.

[0045] [ Figure 2 ] is a top view of the integrated molded body involved in the present invention.

[0046] [ Figure 3 ]for Figure 1 or Figure 2 A-A' cross-sectional view.

[0047] [ Figure 4 ]for Figure 3 The enlarged view of the region of the resin inner component (B1) or the resin outer component (C1) is a schematic cross-sectional view showing the flow state of the resin advancing in the molding die during injection molding.

[0048] [ Figure 5 ]for Figure 3 The enlarged view of the area of ​​the resin inner member (B1) or the resin outer member (C1) is a schematic cross-sectional view showing a state in which resins traveling from the left and right collide with each other to form a molten resin confluence line.

[0049] [ Figure 6 ] is a bottom view of the integrated molded body of the present invention viewed from the non-design surface side, showing the positional relationship of the molten resin confluence line formed by the confluence of resin parts injected from multiple resin injection gates.

[0050] [ Figure 7 ] is a cross-sectional view of the integrated molded body according to the present invention, in which a narrow width portion is provided on a portion of the resin inner component (B1) and the resin outer component (C1).

[0051] [ Figure 8 ] is a top view showing the step [1] of pre-forming the resin outer component (C1) by injecting a precursor of the resin outer component (C1) from a plurality of resin injection gates (GC) in a molding die.

[0052] [ Fig. 9] is a cross-sectional view of a molding die provided with a resin injection gate (GC) for injecting the resin outer component (C1) and a space (cavity) for forming the resin outer component (C1) in the step [1] of pre-forming the resin outer component (C1).

[0053] [ Fig.10 ] represents the state after the upper mold is removed after the resin outer component (C1) precursor is injected to form the resin outer component (C1). Figure 8 BB' cross-sectional view.

[0054] [ Fig.11 ] is an overhead view showing the process [2] of configuring a plate (A) having at least a portion separated from the resin outer component (C1) and a single-side surface as a design surface in a molding die on the inner side of the resin outer component (C1).

[0055] [ Fig.12 ]for Fig.11 C-C' cross-sectional view.

[0056] [ Fig.13 ] is an overhead view showing the process [3] of setting a pre-formed resin outer part (C1) in a molding die and injecting a precursor of a resin inner part (B1) from a plurality of resin injection gates (GB) to form the resin inner part (B1).

[0057] [ Fig.14 ] for Fig.13 A different embodiment shows a bottom view of a process [3] of setting a preformed resin outer part (C1) in a molding die, and injecting a precursor of a resin inner part (B1) from a plurality of resin injection gates (GB) to form the resin inner part (B1).

[0058] [ Fig.15 ] for Fig.13 A different embodiment shows a bottom view of a process [3] of providing a preformed resin outer part (C1) in a molding die, and injecting a precursor of a resin inner part (B1) from a plurality of resin injection gates (GB) to form the resin inner part (B1).

[0059] [ Fig.16 ] for Fig.13 A different embodiment shows a bottom view of a process [3] of providing a preformed resin outer part (C1) in a molding die, and injecting a precursor of a resin inner part (B1) from a plurality of resin injection gates (GB) to form the resin inner part (B1).

[0060] [ Fig.17] is a cross-sectional view of a molding die provided with a resin injection gate (GB) for injecting a precursor of the resin inner component (B1) and a space (cavity) for forming the resin inner component (B1) in the step [3] of forming the resin inner component (B1).

[0061] [ Fig.18 ] represents the state after the upper mold is removed after the resin inner part (B1) precursor is injected to form the resin inner part (B1). Fig.13 D-D' cross-sectional view.

[0062] [ Fig.19 ] is included Fig.13 A cross-sectional view of a component. DETAILED DESCRIPTION

[0063] Hereinafter, the embodiments will be described with reference to the drawings. It should be noted that the present invention is not limited to the drawings and embodiments.

[0064] The structure of the integrated molded body 1 according to the present invention is characterized in that a resin inner member (B1) containing a thermoplastic resin is interposed between a resin outer member (C1) containing a thermoplastic resin and a plate material (A) having a single surface as a design surface, and the integrated molded body is a rectangular planar structure having a first joint portion where a portion or the entire region of the outer peripheral side surface and / or outer peripheral edge of the plate material (A) is joined to the resin inner member (B1), and a second joint portion where a portion or the entire region of the outer peripheral side surface and / or outer peripheral edge of the resin inner member (B1) is joined to the resin outer member (C1). A body, on the side (non-design surface side) opposite to the above-mentioned design surface of the above-mentioned plate material (A), at least one molten resin confluence line is formed in each of the above-mentioned resin inner component (B1) and the above-mentioned resin outer component (C1), and a position of the molten resin confluence line (B2) formed in the above-mentioned resin inner component (B1) determined in a direction parallel to the outer periphery of the above-mentioned integrated molded body and a position of the molten resin confluence line (C2) formed in the above-mentioned resin outer component (C1) located closest to the above-mentioned position of the above-mentioned molten resin confluence line (B2) have a positional relationship of being present at a staggered position.

[0065] The three-dimensional view, top view and AA' cross-sectional view of the integrated molded body 1 according to the present invention are respectively as follows: Figure 1 , Figure 2 and Figure 3As shown. The integrated molded body 1 has a structure in which a resin inner part (B1) 3 is disposed between a plate (A) 2 and a resin outer part (C1) 4. Here, the portion where the plate (A) 2 and the resin inner part (B1) 3 are joined is a first joint portion 5, and the portion where the resin inner part (B1) 3 and the resin outer part (C1) 4 are joined is a second joint portion 6. It should be noted that, for the plate (A) 2, Figure 2 The surface shown, Figure 3 The upper surface in the middle is the design surface.

[0066] Furthermore, in at least a portion of the surface on the design surface side of the integrated molded body 1, there is a region 7 where the plate material (A) 2, the resin inner member (B1) 3, and the resin outer member (C1) 4 are exposed on the same plane.

[0067] The peripheral edge of the sheet (A) 2 refers to a planar region near the peripheral portion of the sheet (A) 2 of the planar structure, and is a region within a width range of 0 to 15% of the length of each side constituting the peripheral end of the sheet (A) 2. The peripheral side surface refers to an end having a perpendicular surface relative to the planar region of the peripheral portion of the sheet (A) 2 of the planar structure. The same is true for the resin inner member (B1) 3.

[0068] Next, the following describes one or more molten resin confluence lines (also called weld lines) formed in each of the resin inner component (B1) 3 and the resin outer component (C1) 4 on the side opposite to the design surface of the plate (A) 2 (non-design surface side).

[0069] When the molten resin part 11 (precursor of the resin inner part (B1) 3 and the resin outer part (C1) 4) is injected into the injection molding die from the plurality of injection resin injection gates, as shown in FIG. Figure 4 As shown in FIG. 1 , along the cavity surface 10 of the molding die, the molten resin part 11 moves in the direction of the arrow 12 in the molding die. It should be noted that the resin injection gate is arranged at Figure 4 The left and right ends are omitted here.

[0070] Then, if Figure 5 As shown, the molten resin part 11 flowing in the molding die moves in a molten state, but the front end of the molten resin part 11 changes from a molten state to a solidified state due to the temperature difference in the cavity as time passes from the injection. Furthermore, since there is also a temperature difference with the cavity surface 10 of the molding die, the area close to the molding die also changes from a molten state to a solidified state. As a result, the molten resin parts 11 moving in the direction of arrow 12 collide with each other in the area 15 while partially changing to a solidified state.

[0071] In the collision area 15, the molten resin part 11 partially changes to a solidified state, so it does not become a completely molten state, forming a molten resin confluence line indicating the collision position. This is also called a weld line, and the area where the molten resin confluence line is formed is an area where the strength of the formed molded product tends to decrease compared to other areas.

[0072] In addition, as described later, when fiber-reinforced resin is used as the molten resin component 11, it is difficult to arrange the reinforcing fibers across the molten resin confluence line at the location where the molten resin confluence line is formed, so the uniform distribution of the reinforcing fibers near the molten resin confluence line is disrupted, and uneven welding strength is likely to occur.

[0073] The integrated molded body 1 of the present invention is characterized in that: at least one molten resin confluence line is formed in each of the resin inner component (B1) 3 and the resin outer component (C1) 4, and a position of the molten resin confluence line (B2) formed in the above-mentioned resin inner component (B1) 3 determined in a direction parallel to the outer periphery of the integrated molded body 1 and a position of the molten resin confluence line (C2) formed in the resin outer component (C1) 4 which is located closest to the position of the molten resin confluence line (B2) have a positional relationship in which they exist at a staggered position.

[0074] exist Figure 6 In one embodiment of the present invention shown in the figure, in the structure shown in the figure, two molten resin confluence lines (B2) 16 are formed on the upper and lower sides of the resin inner part (B1) 3, and one is formed on the left and right sides. In addition, in the structure shown in the figure, two molten resin confluence lines (C2) 17 are formed on the upper and lower sides of the resin outer part (C1) 4, and two are formed in the center of the left and right sides. Figure 6 In the embodiment, when the position of the molten resin confluence line (B2) 16 and the position of the molten resin confluence line (C2) 17 are compared along the direction parallel to the outer periphery of the integrated molded body 1, both positions are arranged at offset positions. That is, the molten resin confluence line (B2) 16 and the molten resin confluence line (C2) 17 are arranged so as not to form a continuous weld line. By forming such a structure, the lack of strength of the portion where the weld line as the molten resin confluence line is formed is complementarily compensated by other resin parts where no weld line is formed, thereby preventing the strength of the entire molded body from decreasing.

[0075] In addition, in the present invention, the ratio of the distance M2 (mm) 19 between the molten resin confluence line (B2) 16 and the molten resin confluence line (C2) 17 closest to the molten resin confluence line (B2) 16 to the outer circumference M1 (mm) 18 of the integrated molded body 1 is preferably 0.04 to 0.4.

[0076] like Figure 6As shown, by making the distance between the molten resin confluence line (B2) 16 and the closest molten resin confluence line (C2) 17 and the outer circumference of the integrated molded body 1 satisfy a certain relationship, the strength of the position where the weld line is formed (hereinafter referred to as welding strength) can be improved compared to the case where the welding positions overlap.

[0077] When M2 / M1 is less than 0.04, the distance between the molten resin confluence line (B2) 16 and the closest molten resin confluence line (C2) 17 becomes narrower, and the weld strength becomes insufficient. On the other hand, when M2 / M1 is greater than 0.4, although a certain distance can be ensured between the molten resin confluence line (B2) 16 and the closest molten resin confluence line (C2) 17, it will not contribute to the improvement of the weld strength. The more preferred range of M2 / M1 is 0.07 to 0.4, and the further preferred range is 0.10 to 0.4.

[0078] In the present invention, it is preferred that a molten resin confluence line (B2) 16 is formed in a narrow width portion (B1') 18 provided at a portion of the resin inner member (B1) 3. Similarly, it is preferred that a molten resin confluence line (C2) 17 is formed in a narrow width portion (C1') 19 provided at a portion of the resin outer member (C1) 4. By forming the molten resin confluence line in the narrow width portion (C1') 19 having a narrowed width, the width of the molten resin confluence line, which is one of the factors causing the strength reduction of the molded body, can be shortened, and the strength reduction can be suppressed.

[0079] Figure 7 The example of forming a narrow width portion by repeatedly forming a concave-convex shape on the resin inner member (B1) 3 and the resin outer member (C1) 4 is shown. A molten resin confluence line (B2) 16 is formed in the narrow width portion (B1') 24 of the resin inner member (B1) 3, and a molten resin confluence line (C2) 17 is formed in the narrow width portion (C1') 25 of the resin outer member (C1) 4. Such a narrow width portion can be formed by adjusting the position of the resin injection gate, etc.

[0080] In addition, in the present invention, it is preferred that the first joint 5 is formed over the entire periphery of the outer peripheral side surface of the plate (A) 2. By forming the first joint 5 with the resin inner member (B1) 3 over the entire periphery of the outer peripheral side surface of the plate (A) 2, as an integrated molded body 1, high joint strength and thin wall can be achieved.

[0081] In addition, in the present invention, it is preferred that the second joining portion 6 is formed over the entire outer peripheral side surface of the resin inner member (B1) 3. By forming the second joining portion 6 with the resin outer member (C1) 4 over the entire outer peripheral side surface of the resin inner member (B1) 3, high joining strength and thinning can be achieved as the integrated molded body 1.

[0082] In the present invention, it is preferred that the resin inner member (B1) 3 or the resin outer member (C1) 4 contain reinforcing fibers, the reinforcing fibers are discontinuous fibers, and the weight average fiber length of the discontinuous fibers is 0.3 to 3 mm.

[0083] Here, continuous fibers and discontinuous fibers are defined. The so-called continuous fibers refer to reinforcing fibers contained in the integrated molded body 1 that are substantially continuously arranged over the entire length or width of the integrated molded body 1, and the so-called discontinuous fibers refer to reinforcing fibers that are intermittently divided and distributed.

[0084] When the weight-average fiber length of the discontinuous reinforcing fibers remaining in the resin inner part (B1) 3 or the resin outer part (C1) 4 is 0.3 mm or more, the shrinkage rate of the resin inner part (B1) 3 and the resin outer part (C1) 4 can be reduced, and the warpage of the integrated molded body 1 can be further reduced. When the weight-average fiber length is less than 0.3 mm, the effect of low shrinkage rate becomes weak, and sometimes it is not possible to fully reduce the warpage of the integrated molded body 1. When the weight-average fiber length is greater than 3 mm, the viscosity of the resin becomes high, and it is sometimes difficult to uniformly fill the resin inner part (B1) 3 or the resin outer part (C1) 4 into the corner part of the molding mold during injection molding. The weight-average fiber length of the discontinuous carbon fiber is preferably 0.4 to 2.8 mm, more preferably 0.7 to 1.5 mm, and even more preferably 0.9 to 1.2 mm.

[0085] Here, the "weight average fiber length" in the present invention is not a simple number average, but refers to the average fiber length calculated by applying the calculation method of the weight average molecular weight to the calculation of the fiber length according to the following formula taking into account the contribution of the fiber length. The following formula is applied assuming that the fiber diameter and density of the reinforcing fiber are constant.

[0086] Weight average fiber length = Σ(Mi2×Ni) / Σ(Mi×Ni)

[0087] Mi: Fiber length (mm)

[0088] Ni: Number of reinforcing fibers with a fiber length of Mi

[0089] The above-mentioned weight average fiber length can be measured by the following method. Heat the molded product at 500°C for 60 minutes, take out the reinforcing fibers in the molded product, and evenly disperse the reinforcing fibers in water. After sampling the dispersion water in which the reinforcing fibers are evenly dispersed into a petri dish, dry it, and observe it using an optical microscope (50 to 200 times). Measure the lengths of 500 randomly selected reinforcing fibers, and calculate the weight average fiber length according to the above formula.

[0090] In addition, in the present invention, it is preferred that the resin inner part (B1) 3 or the resin outer part (C1) 4 contain reinforcing fibers, and the weight average fiber content of the reinforcing fibers is 1 to 50% by weight of discontinuous fibers. It is possible to reduce the warping of the molded body 1 while improving the bonding strength. When it is less than 1% by weight, it is sometimes difficult to ensure the strength of the molded body 1; when it is greater than 50% by weight, during injection molding, the filling of the resin inner part (B1) 3 or the resin outer part (C1) 4 sometimes becomes insufficient. It is preferably 5 to 40% by weight, more preferably 8 to 35% by weight, and even more preferably 12 to 30% by weight.

[0091] In the present invention, from the viewpoint of rigidity and lightness, the discontinuous fibers contained in the resin inner member (B1) 3 are preferably carbon fibers.

[0092] In the present invention, the discontinuous fibers contained in the resin exterior member (C1) 4 are preferably glass fibers. By using glass fibers in the resin exterior member (C1) 4, the resin exterior member (C1) 4 can be provided with a function as a radio wave transmitting member.

[0093] In addition, it is preferable to use a thermoplastic resin as the resin inner member (B1) 3 or the resin outer member (C1) 4, so that the thermoplastic resin of the resin inner member (B1) 3 and the thermoplastic resin of the resin outer member (C1) 4 are melted and fixed. As a result, a higher bonding strength can be achieved as the integrated molded body 1. The melt-fixed bonding structure refers to a bonding structure in which the parts are melted to each other by heat and are fixed by cooling.

[0094] In the present invention, the plate material (A) 2 is preferably a structure including any one of a metal member and a carbon fiber reinforced resin member.

[0095] From the viewpoint of improving the strength and rigidity of the integrated molded body 1, the plate (A) 2 preferably uses a component that is high in strength, high in rigidity, and excellent in lightness. From the perspective of high strength and high rigidity, it is preferred to use a metal component or a fiber-reinforced resin component. For the purpose of further improving lightness, the following sandwich structure is more preferred: a core component selected from a resin sheet, a foam, and a material in which a discontinuous fiber-reinforced resin containing discontinuous fibers in the resin is expanded in the thickness direction is used as a core layer, and a metal component or a fiber-reinforced resin component is used as a surface layer to form a structure in which the surface layer sandwiches the two sides of the core layer. Here, by using a carbon fiber-reinforced resin component in which carbon fiber is used as the reinforcing fiber of the fiber-reinforced resin component, high rigidity, lightness, and thin-walling can be achieved.

[0096] On the other hand, metal parts include elements selected from titanium, steel, stainless steel, aluminum, magnesium, iron, silver, gold, platinum, copper, and nickel, or alloys containing these elements as main components. In addition, electroplating treatment may be performed as needed.

[0097] As the resin used for the fiber-reinforced resin component, the carbon fiber-reinforced resin component, or the core component, a thermoplastic resin or a thermosetting resin is suitably used.

[0098] The type of thermoplastic resin constituting the plate (A) 2, the resin inner member (B1) 3 or the resin outer member (C1) 4 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, liquid crystal polyester resin, etc., polyolefin resins such as polyethylene (PE) resin, polypropylene (PP) resin, polybutylene resin, polyoxymethylene (POM) resin, polyamide (PA) resin, polyphenylene sulfide (PPS) resin, etc., polyketone (PK) resin, polyether ketone (PEK) resin, polyether ether ketone (PEEK) resin, polyether ketone ketone (PEKK) resin, polyether nitrile (PEN) resin, polytetrafluoroethylene resin, etc., liquid crystal polymer (LCP) crystalline resin, Styrene resins, other non-crystalline resins include polycarbonate (PC) resins, polymethyl methacrylate (PMMA) resins, polyvinyl chloride (PVC) resins, polyphenylene ether (PPE) resins, polyimide (PI) resins, polyamideimide (PAI) resins, polyetherimide (PEI) resins, polysulfone (PSU) resins, polyethersulfone resins, polyarylate (PAR) resins, etc., other non-crystalline resins include phenolic resins, phenoxy resins, and further thermoplastic resins selected from polystyrene resins, polyolefin resins, polyurethane resins, polyester resins, polyamide resins, polybutadiene resins, polyisoprene resins, fluorine resins, and thermoplastic elastomers such as acrylonitrile, copolymers thereof, and modified bodies thereof. Among them, from the viewpoint of lightness of the obtained molded article, polyolefin resins are preferred, from the viewpoint of strength, polyamide resins are preferred, from the viewpoint of surface appearance, amorphous resins such as polycarbonate resins, styrene resins, and modified polyphenylene ether resins are preferred, from the viewpoint of heat resistance, polyphenylene sulfide is preferred, and from the viewpoint of continuous use temperature, polyetheretherketone is preferably used.

[0099] In addition, as the thermosetting resin constituting the sheet (A) 2, unsaturated polyester resin, vinyl ester resin, epoxy resin, phenolic (Resol type) resin, urea melamine resin, polyimide resin, maleimide resin, benzoxazine resin and other thermosetting resins can be preferably used. These thermosetting resins can be applied to be mixed with two or more resins. Among them, especially from the viewpoint of mechanical properties and heat resistance of the molded body, epoxy resin is preferred. In order to present its excellent mechanical properties, it is preferred to include epoxy resin as the main component of the resin used, specifically, preferably 60% by weight or more relative to the resin composition.

[0100] As carbon fibers constituting the plate (A) 2 or the resin inner member (B1) 3, carbon fibers of polyacrylonitrile (PAN), pitch, rayon, etc. having excellent specific strength and specific rigidity are preferably used from the viewpoint of weight reduction effect. Polyacrylonitrile (PAN) carbon fibers are more preferred.

[0101] Hereinafter, a method for producing an integrated molded body according to the present invention will be described with reference to the drawings.

[0102] The method for producing an integrated molded body according to the present invention is a method for producing an integrated molded body having a planar structure having a rectangular shape by the following steps [1] to [3]:

[0103] Step [1], injecting a precursor of the resin outer component (C1) 4 into the molding die from a plurality of resin injection gates (GC) 21 to preform the resin outer component (C1) 4;

[0104] Step [2], disposing a plate (A) inside the resin outer member (C1) 4 at a position separated from at least a portion of the resin outer member (C1); and

[0105] Step [3], injecting a precursor of the resin inner component (B1) 3 into a gap between the plate (A) 2 and the resin outer component (C1) 4 through a plurality of resin injection gates (GB) 22, thereby forming a first joint portion where at least a portion of the outer peripheral side surface and / or outer peripheral edge of the plate (A) 2 is joined to the resin inner component (B1) 3, and a second joint portion 6 where at least a portion of the outer peripheral side surface and / or outer peripheral edge of the resin inner component (B1) 3 is joined to the resin outer component (C1) 4,

[0106] Among them, the injection conditions of the precursor of the resin inner part (B1) 3 and the precursor of the resin outer part (C1) 4 are adjusted so that when observed from the side opposite to the design surface of the plate (A) 2 (non-design surface side), the position of the molten resin convergence line (B2) 16 formed in the resin inner part (B1) 3 determined along the direction parallel to the outer periphery of the above-mentioned integrated molded body 1 and the position of the molten resin convergence line (C2) 17 formed in the resin outer part (C1) 4 and located closest to the molten resin convergence line (B2) 16 are offset in at least one place.

[0107] like Figure 8 or Fig. 9 As shown, process [1] is a process of injecting a precursor of a resin outer component (C1) 4 from a plurality of resin injection gates (GC) 21 into a molding lower mold 30 and a molding upper mold 31 provided with a space (cavity) for forming a resin outer component (C1) 4, thereby forming a resin outer component (C1) 4.

[0108] exist Figure 8 In the embodiment shown, the resin injection gates (GC) 21 are arranged one each on the upper and lower sides and two each on the left and right sides of the resin outer member (C1) 4, and the molten resin confluence lines (C2) 17 are formed two each on the upper and lower sides and one each on the left and right sides of the resin outer member (C1) 4. The molten resin confluence lines (C2) 17 are formed near the middle of the adjacent resin injection gates (GC) 21.

[0109] Then, after the resin outer member (C1) 4 is cooled, Fig.10 As shown, take out the upper mold 31. It should be noted that, respectively Figure 8 The figure shows the method of injecting resin from the lateral direction through the resin injection gate (GC) 21. Fig. 9 The method of injecting resin from above is shown in the figure, but it is only shown for the sake of understanding the injection position, and the injection method can be appropriately set according to the shape of the molding die, etc. The same applies to the following description.

[0110] Then, if Fig.11 or Fig.12 As shown, step [2] is a step of arranging a plate (A) inside the resin outer member (C1) 4 at a position separated from at least a portion of the resin outer member (C1) 4. Here, the plate (A) 2 is preliminarily produced so that one side surface becomes a design surface.

[0111] Then, if Fig.13 or Fig.14As shown, step [3] is to inject the precursor of the resin inner component (B1) 3 into the gap between the plate (A) 2 and the resin outer component (C1) 4 in the molding lower mold 30 and the molding upper mold 32, which are provided with a space (cavity) for forming the resin inner component (B1) 3, through multiple resin injection gates (GB) 22, thereby forming the resin inner component (B1) 3 joined to the plate (A) 2 and the resin outer component (C1) 4.

[0112] Here, the resin injection gate (GB) 22 used to form the resin inner part (B1) 3 is arranged one each on the upper and lower sides of the resin inner part (B1) 3, and two each on the left and right sides, so that the molten resin confluence line (B2) 16 is formed two each on the upper and lower sides of the resin inner part (B1) 3, and one each on the left and right sides.

[0113] Then, after the resin inner part (B1) 3 is cooled, the upper mold 32 is taken out, as shown in FIG. Fig.18 As shown, an integrated molded body 1 can be obtained.

[0114] In order to offset the position of the molten resin confluence line (B2) 16 from the position of the molten resin confluence line (C2) 17, it is important to adjust the injection conditions of the precursor of the resin inner part (B1) 3 or the precursor of the resin outer part (C1) 4. By adjusting the injection conditions so that the position of the molten resin confluence line (B2) 16 and the position of the molten resin confluence line (C2) 17 are offset, it is possible to suppress the reduction in the strength of the molded body.

[0115] As a method of adjusting the injection conditions so that the position of the molten resin confluence line (B2) 16 and the position of the molten resin confluence line (C2) 17 are offset, as shown in FIG. Fig.13 As shown, it is preferred that one of the plurality of resin injection gates (GB) 22 of the precursor of the injection-injected resin inner part (B1) 3 and the position of the resin injection gate (GC) 21 of the precursor of the injection-injected resin outer part (C1) 4, which is located at a position closest to the position of the resin injection gate (GB) 22, are arranged at offset positions relative to the direction parallel to the outer periphery of the integrated molded body 1. By forming such a positional configuration, the molten resin confluence lines formed in the resin inner part (B1) 3 and the resin outer part (C1) 4 are offset from each other, and by complementarily compensating for the insufficient strength of the weld line with other resin parts, it is possible to prevent the strength of the molded body as a whole from decreasing.

[0116] In addition, as one of other methods for adjusting the injection conditions, it may be impossible to shift the position of the resin injection gate in consideration of the configuration of the device.

[0117] In such a case, as a method for shifting the molten resin confluence lines, it is preferable to set a difference in injection pressure when injecting the resin part from the adjacent resin injection gates, for example, in the resin injection gate (GB) 22 of the precursor of the injection resin inner part (B1) 3. In this way, the position where the molten resin confluence line is formed can be made to merge at a position shifted to either side from the center between the adjacent resin injection gates.

[0118] It is also preferred that a method is adopted in which a difference is set in injection pressure between the resin injection gates (GB) 22, and a difference is set in injection pressure between a plurality of resin injection gates (GC) 21 for injecting the precursor of the adjacent resin outer member (C1) 4. In this case, it is more preferred to adjust the injection pressures of both so that the molten resin confluence line is offset.

[0119] Fig.19 Shown in Fig.13 A cross-sectional view of the resin inner part (B1) 3, the resin outer part (C1) 4, and the molten resin confluence line formed therein. The resin injection gate (GB) 22 and the resin injection gate (GC) 21 are arranged on the same line without being staggered in order to miniaturize the molding device. When the resin inner part (B1) is injected from the adjacent resin injection gates 22a and 22b of the resin injection gate (GB) 22, the molten resin confluence line 16 is formed by setting the injection pressure of the resin injection gate 22b higher, thereby deviating to the resin injection gate 22a.

[0120] In addition, on the resin outer member (C1) 4 side, when the resin outer member (C1) is injected from the adjacent resin injection gates 21a and 21b of the resin injection gate (GC) 21, the injection pressure of the resin injection gate 21a is set high, so that the molten resin confluence line 17 is formed biased toward the resin injection gate 21b. As a result, the molten resin confluence line 16 and the molten resin confluence line 17 can be formed at separate positions.

[0121] As another method, it is also a preferable method to set a difference in the resin temperature when the resin is injected between adjacent resin injection gates.

[0122] In addition, as another method, it is also a preferred method to provide at least one portion with different cross-sectional areas on a surface perpendicular to the flow direction of the precursor of the resin inner part (B1) 3 in the flow path of the precursor of the resin inner part (B1) 3 that connects adjacent resin injection gates of the precursor of the injected resin inner part (B1) 3 to each other.

[0123] Example

[0124] Hereinafter, the integrated molded body 1 and the method for producing the same of the present invention will be specifically described using examples, but the following examples do not limit the present invention.

[0125] The measuring methods used in the examples are as follows.

[0126] (1) Measurement of weld strength of integrated molded body

[0127] With the design surface side of the integrated molded body facing upward, two cubic blocks made of SUS304 with a length of 10 mm, a width of 10 mm, and a height of 10 mm were placed 50 mm apart, and the molten resin confluence line (B2) formed in the resin inner part (B1) was arranged on it in such a way that it came to the center of the span. The push-pull force gauge is pushed to the molten resin confluence line (B2) formed in the resin inner part (B1), and the value when the resin inner part (B1) is destroyed is measured. The measurement position is a total of 6 points, 4 points on the long side and 2 points on the short side. Next, the molten resin confluence line (C2) formed in the resin outer part (C1) is arranged in such a way that it comes to the center of the span. The push-pull force gauge is pushed to the molten resin confluence line (C2) formed in the resin outer part (C1), and the value when the resin outer part (C2) is destroyed is measured. The measurement position is a total of 8 points, 4 points on the long side and 4 points on the short side. Then, the values ​​of each weld strength obtained are evaluated using the following criteria. A is qualified and B is unqualified.

[0128] A: The weld strength at each measurement location is 98 N (10 Kg·f) or more.

[0129] B: The weld strength at at least one point among the measurement locations is less than 98 N (10 Kg·f).

[0130] (Material Composition Example 1) Preparation of PAN-based carbon fiber bundle

[0131] A continuous carbon fiber bundle with a total number of 12,000 filaments was obtained by spinning and firing a polymer mainly composed of polyacrylonitrile. A sizing agent was applied to the continuous carbon fiber bundle by an impregnation method and dried in heated air to obtain a PAN-based carbon fiber bundle. The properties of the PAN-based carbon fiber bundle are shown below.

[0132] Carbon fiber diameter: 7μm

[0133] Mass per unit length: 0.83 g / m

[0134] Density: 1.8g / cm 3

[0135] Tensile strength: 4.0GPa

[0136] Tensile elastic modulus: 235GPa

[0137] (Material Composition Example 2) Preparation of Epoxy Resin Film

[0138] An epoxy resin (base resin: dicyandiamide / dichlorophenylmethyl urea curing epoxy resin) was applied onto release paper using a knife coater to obtain an epoxy resin film.

[0139] (Material Composition Example 3) Preparation of Unidirectional Prepreg

[0140] The PAN-based carbon fiber bundle obtained in Material Composition Example 1 is arranged in a unidirectional sheet shape, and two sheets of epoxy resin films prepared in Material Composition Example 2 are overlapped on both sides of the carbon fiber. The resin is impregnated by heating and pressing to prepare a unidirectional prepreg blank with a carbon fiber weight content of 70% and a thickness of 0.15 mm.

[0141] (Material Composition Example 4) Preparation of Thermoplastic Adhesive Film (D)

[0142] A polyester resin ("Hytrel" (registered trademark) 4057 manufactured by Toray-DuPont Co., Ltd.) was fed from the hopper of a twin-screw extruder, melt-kneaded in the extruder, and extruded from a T-die. Then, the resin was cooled and solidified by pulling with a cooling roll at 60°C to obtain a polyester resin film with a thickness of 0.05 mm. This was used as a thermoplastic adhesive film (D).

[0143] (Material Composition Example 5) Glass Fiber Reinforced Polycarbonate Resin

[0144] Glass fiber-reinforced polycarbonate resin GSH2030KR (manufactured by Mitsubishi Engineering-Plastics Corporation, polycarbonate resin matrix, fiber weight content 30 wt %) was used.

[0145] (Material Composition Example 6) Long Carbon Fiber Reinforced Nylon Resin

[0146] The long carbon fiber pellets TLP-1146S (manufactured by Toray Industries, Ltd., nylon 6 resin matrix, fiber weight content 20wt%) and nylon 6 resin CM1007 (manufactured by Toray Industries, Ltd., nylon 6 resin matrix, unreinforced) are dry-mixed to obtain a long carbon fiber reinforced nylon resin with a fiber weight content of 15wt%.

[0147] (Example 1)

[0148] The unidirectional prepreg obtained in Material Composition Example 3 and the thermoplastic adhesive film (D) obtained in Material Composition Example 4 are used, and after adjusting the size to 400 mm square, they are stacked in the order of [unidirectional prepreg 0° / unidirectional prepreg 90° / unidirectional prepreg 0° / unidirectional prepreg 90° / unidirectional prepreg 90° / unidirectional prepreg 0° / unidirectional prepreg 90° / unidirectional prepreg 0° / unidirectional prepreg 90° / unidirectional prepreg 0° / adhesive film]. The stack is clamped with a release film and then clamped with a tool plate. Here, as a thickness adjustment, a spacer with a thickness of 1.25 mm is inserted between the tool plates. After the tool plate is arranged on the disk surface with a disk surface temperature of 150°, the disk surface is closed and heated and pressurized at 3 MPa. After 5 minutes from the start of pressurization, the disk surface is opened to obtain a thermosetting CFRP plate with a thermoplastic adhesive film (D) formed into a flat plate shape with a thickness of 1.25 mm. This is referred to as a sheet (A) 2 to which a thermoplastic adhesive film (D) is attached.

[0149] Next, the GF-reinforced polycarbonate resin of Material Composition Example 5 was used. Figure 8 In the mold shown, at 150MPa, barrel temperature 320℃, mold temperature 120℃, and resin outlet diameter Injection molding is performed under the conditions of Figure 2 The frame member shown in the figure has a square frame shape with a width of 2.0 mm and a thickness of 3.0 mm. This is referred to as the resin outer member (C1).

[0150] Then, if Fig.17 As shown in FIG. 1 , a CFRP plate (plate material (A) 2) with a thermoplastic adhesive film processed into a size of 300 mm × 200 mm is arranged inside the resin outer member (C1) in a state separated from the resin outer member (C1) with the design surface side facing the molding lower mold 30 side. After the molding upper mold 32 is set, a glass fiber reinforced polycarbonate resin is used. Fig.13 In the mold shown, at 150MPa, barrel temperature 320℃, mold temperature 120℃, and the diameter of the resin outlet is The GF reinforced polycarbonate resin (resin inner part (B1)) of material composition example 5 is injection molded to produce Figure 3 The integrated molded body 1 composed of the top plate (plate material (A) 2) is shown in the schematic diagram of . The properties of the integrated molded body of Example 1 are summarized in (Table 1).

[0151] (Example 2)

[0152] Change the position of the resin injection gate (GC) of the resin outer part (C1) to Fig.14The integral molded body 1 was produced in the same manner as in Example 1 except that the positions shown were changed. Table 1 shows the properties of the integral molded body 1 in summary.

[0153] (Example 3)

[0154] Change the position of the resin injection gate (GC) of the resin outer part (C1) to Fig.15 The integral molded body 1 was produced in the same manner as in Example 1 except that the positions shown were changed. Table 1 shows the properties of the integral molded body 1 in summary.

[0155] (Example 4)

[0156] An integrated molded body was produced in the same manner as in Example 1 except that the materials of the resin outer member (C1) and the resin inner member (B1) were changed. The properties of the integrated molded body 1 are summarized in Table 1.

[0157] (Example 5)

[0158] An integrated molded body was produced in the same manner as in Example 3 except that the materials of the resin outer member (C1) and the resin inner member (B1) were changed. The properties of the integrated molded body 1 are summarized in Table 1.

[0159] (Comparative Example 1)

[0160] Change the position of the resin injection gate (GC) of the resin outer part (C1) to Fig.16 The integral molded body 1 was produced in the same manner as in Example 1 except that the positions shown were changed. Table 1 shows the properties of the integral molded body 1 in summary.

[0161] [Table 1]

[0162]

[0163] Industrial Applicability

[0164] The integrated molded article of the present invention can be effectively used for automobile interior and exterior decoration, electrical and electronic equipment housings, bicycles, structural parts for sporting goods, aircraft interior decoration parts, transportation boxes, and the like.

[0165] Description of Reference Numerals

[0166] 1 Integrated molding

[0167] 2 Plate (A)

[0168] 3 Resin inner parts (B1)

[0169] 4 Resin outer parts (C1)

[0170] 5 1st joint

[0171] 6 Second joint

[0172] 7 Area where the plate (A), the resin inner part (B1), and the resin outer part (C1) are exposed

[0173] 10 Cavity surface of the molding die

[0174] 11 Molten resin parts

[0175] 12 Moving direction of resin parts in the molding die

[0176] 13 Resin parts near the surface

[0177] 14 Molten resin parts inside

[0178] 15 Areas where resins collide with each other

[0179] 16 Molten resin confluence line (B2)

[0180] 17 Molten resin confluence line (C2)

[0181] 18 The outer perimeter length of the integrated molding body M1

[0182] 19 Distance M2 between the molten resin confluence line (B2) and the closest molten resin confluence line (C2)

[0183] 21 Resin injection gate (GC)

[0184] 22 Resin injection gate (GB)

[0185] 23 Distance L2 between the resin injection gate (GB) and the closest resin injection gate (GC)

[0186] 24 Narrow area of ​​the resin inner part (B1)

[0187] 25 Narrow area of ​​the resin outer part (C1)

[0188] 30 Molding lower mold

[0189] 31 Forming upper mold

[0190] 32 Forming upper mold

Claims

1. A method for manufacturing an integrated molded body, characterized in that: This is a method for producing an integrated molded body having a rectangular planar structure by the following steps: In a first step, a precursor of a resin exterior component C1 is injected into a lower mold of a molding mold including an upper mold and a lower mold through a plurality of resin injection gates GC to preliminarily form the resin exterior component C1; In a second step, a plate A is arranged inside the resin outer member C1 of the lower mold at a position separated from at least a portion of the resin outer member C1; as well as In the third step, a precursor of the resin inner component B1 is injected into the gap between the plate A and the resin outer component C1 of the lower mold through a plurality of resin injection gates GB, thereby forming a first joint portion where at least a portion of the outer peripheral side surface and / or outer peripheral edge of the plate A is joined to the resin inner component B1, and a second joint portion where at least a portion of the outer peripheral side surface and / or outer peripheral edge of the resin inner component B1 is joined to the resin outer component C1. The resin inner component B1 and the resin outer component C1 contain the same type of thermoplastic resin, and the injection conditions of the precursor of the resin inner component B1 and the precursor of the resin outer component C1 are adjusted so that when viewed from the side opposite to the design surface of the sheet A, that is, the non-design surface side, the position of the molten resin confluence line B2 formed in the resin inner component B1 determined in a direction parallel to the outer periphery of the integrated molded body is the same as the position of the molten resin confluence line B2 formed in the resin outer component C1. The position of the formed molten resin confluence line C2 is staggered at at least one location, and a ratio M2 / M1 of a distance M2 between the molten resin confluence line B2 and a molten resin confluence line C2 closest to the molten resin confluence line B2 relative to an outer perimeter M1 of the integrated molded body is 0.07 to 0.4, and the units of M1 and M2 are mm. The resin inner component B1 or the resin outer component C1 contains reinforcing fibers, and the reinforcing fibers are discontinuous fibers. The weight-average fiber length of the discontinuous fibers is 0.3 to 3 mm.

2. The method for producing an integrated molded body according to claim 1, wherein: The injection conditions are as follows: a position of one of the multiple resin injection gates GB for injecting the precursor of the resin inner component B1 and a position of the resin injection gate GC for injecting the precursor of the resin outer component C1, which is set at a position closest to the position of the resin injection gate GB, are set at a staggered position relative to a direction parallel to the outer periphery of the integrated molded body.

3. An integrated molded body manufactured by the method for manufacturing an integrated molded body according to claim 1, characterized in that: A resin inner component B1 containing a thermoplastic resin is interposed between a resin outer component C1 containing the thermoplastic resin and a plate material A having a single surface as a design surface, and the integrated molded body is a rectangular planar structure having a first joint portion where at least a portion of an outer peripheral side surface and / or an outer peripheral edge of the plate material A is joined to the resin inner component B1, and a second joint portion where at least a portion of an outer peripheral side surface and / or an outer peripheral edge of the resin inner component B1 is joined to the resin outer component C1. On the side opposite to the design surface of the sheet A, i.e., the non-design surface side, one or more molten resin confluence lines are formed in each of the resin inner component B1 and the resin outer component C1, and a position of the molten resin confluence line B2 formed in the resin inner component B1 and determined in a direction parallel to the outer periphery of the integrated molded body and a position of the molten resin confluence line C2 formed in the resin outer component C1 and located closest to the position of the molten resin confluence line B2 have a positional relationship of being at a staggered position. The ratio M2 / M1 of the distance M2 between the molten resin confluence line B2 and the molten resin confluence line C2 closest to the molten resin confluence line B2 to the outer perimeter M1 of the integrated molded body is 0.07 to 0.4, and the units of M1 and M2 are mm. The resin inner component B1 or the resin outer component C1 contains reinforcing fibers, and the reinforcing fibers are discontinuous fibers. The weight average fiber length of the discontinuous fibers is 0.3 to 3 mm.

4. The integrated molded body according to claim 3, wherein: The molten resin confluence line B2 is formed in a narrow width portion B1 ′ provided at a portion of the resin inner member B1 .

5. The integrated molded body according to claim 3 or 4, wherein: The molten resin confluence line C2 is formed in a narrow width portion C1 ′ provided at a portion of the resin exterior member C1 .

6. The integrated molded body according to claim 3 or 4, wherein: The first joining portion is formed over the entire circumference of the outer peripheral side surface and / or the outer peripheral edge of the plate material A.

7. The integrated molded body according to claim 3 or 4, wherein: The second joining portion is formed over the entire circumference of the outer peripheral side surface portion and / or the outer peripheral edge portion of the resin inner member B1.

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