Integrally molding article and method for manufacturing the same

Abstract

To provide an integrally molded article including a fiber-reinforced resin member in which a thickness of a resin layer serving as a joint can be easily controlled, and a method for manufacturing the same.SOLUTION: There is provided an integrally molded article in which a first member (A) made of a fiber-reinforced resin having a spacer on its surface and a second member (B) supported by the spacer are joined via a resin layer, wherein the spacer is composed of multiple pillars with a height of 50 to 5000 μm and a minimum width of 0.05 to 10 mm, and a projected area of the pillars on a joint surface between the first member (A) and the second member (B) is 5 to 50%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an integrally molded product formed by joining a first member and a second member made of fiber-reinforced resin, and a method for manufacturing the same. [Background technology]

[0002] Fiber-reinforced resin materials, which use thermosetting or thermoplastic resin as a matrix and combine it with reinforcing fibers such as carbon fiber or glass fiber, are lightweight yet have excellent mechanical properties such as strength and rigidity, as well as heat resistance and corrosion resistance, and have therefore been applied in many fields, including aerospace, automobiles, railway vehicles, ships, civil engineering and construction, and sporting goods.

[0003] However, fiber-reinforced resin materials are not suitable for manufacturing parts or structures with complex shapes in a single molding process. Therefore, in the above applications, it is necessary to prepare a component made of the fiber-reinforced resin material and then integrate it with other components of the same or different types. Common methods for integrating fiber-reinforced resin materials with other components of the same or different types include joining them by thermal welding using a thermoplastic resin as a matrix, and joining them with an adhesive. Patent Document 1 also describes a fiber-reinforced resin material that can be thermally welded to other components due to the presence of a thermoplastic resin layer on the surface of the thermosetting fiber-reinforced resin material. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2004 / 060658 Summary of the Invention [Problem to be solved by the invention]

[0005] When joining a fiber-reinforced resin member to another member by welding or bonding with an adhesive, the thickness of the resin layer at the joint affects the dimensional accuracy and joining characteristics of the integrated molded product, making it important to control the thickness. However, unless special jigs or devices are used, uneven contact occurs due to uneven component placement or pressure application, making it difficult to control the thickness of the resin layer. The object of the present invention is to provide an integrated molded product including a fiber-reinforced resin member, and a method for manufacturing the same, in which the thickness of the resin layer at the joint can be easily controlled. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the present invention provides an integrally molded product formed by joining a first member (A) made of a fiber-reinforced resin having spacers on its surface and a second member (B) supported by the spacers via a resin layer, wherein the spacers are composed of a plurality of pillars having a height of 50 to 5000 μm and a minimum width of 0.05 to 10 mm, and the projected area of ​​the pillars occupying 5 to 50% of the joint surface between the first member (A) and the second member (B) is the integrally molded product. [Effects of the Invention]

[0007] By adopting the configuration of the present invention, it is possible to reduce variations in the thickness of the resin layer that forms the joint, and to obtain an integrally molded product that is excellent in dimensional accuracy and joint characteristics. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a cross-sectional schematic view of one embodiment of an integrally molded product. [Figure 2] 1A is a perspective view of a first member (A) having a columnar body in the shape of a truncated quadrangular pyramid, FIG. 1B is a schematic view from directly above, and FIG. 1C is a schematic cross-sectional view of the columnar body alone. [Figure 3] 1A to 1C are cross-sectional schematic diagrams showing various cross-sectional shapes of pillars. [Figure 4] FIG. 1 is a cross-sectional view showing a preferred embodiment of a first member (A) and a second member (B) in the first embodiment. [Figure 5] FIG. 2 is a schematic diagram showing a method for joining a first member (A) and a second member (B) in the first embodiment. [Figure 6] FIG. 10 is a schematic diagram showing a method for joining a first member (A) and a second member (B) in a second embodiment. [Figure 7] FIG. 10 is a schematic diagram showing a method for joining a first member (A) and a second member (B) in a third embodiment. [Figure 8] 1A is a schematic diagram of a first member (A) having pillars arranged in a dot pattern, viewed from directly above, and FIGS. 1B and 1C are schematic cross-sectional views of the pillars alone. [Figure 9] FIG. 1A is a schematic diagram of a first member (A) having columns arranged in stripes, as viewed from directly above, and FIG. 1B is a schematic cross-sectional view of only the columns. [Figure 10] FIG. 1 is a schematic diagram showing an integrally molded product in which a first member (A) is embedded in a second member (B). DETAILED DESCRIPTION OF THE INVENTION

[0009] The integrally molded product of the present invention will be described in detail below. In this specification, the first and second members formed into an integrally molded product will generally be referred to as the first member (A) and the second member (B), respectively. When specifically describing the first and second members in an unintegrated state before joining, the terms first member (A') and second member (B') may be used. However, when describing matters common to both before and after joining, the terms first member (A) and second member (B) will be used without a strict distinction. These symbols are used for reference to facilitate understanding of the text. Even without these symbols, the concepts referred to by the first and second members are clear depending on the context. Therefore, these symbols do not have any limitations on the present invention.

[0010] The integrally molded product of the present invention is formed by bonding a first member (A) made of fiber-reinforced resin to a second member (B). The first member (A) has a spacer composed of a plurality of pillars on its surface, and the second member (B) is bonded to the first member (A) so as to be supported by the spacer. Here, the pillars are structures formed to protrude from the surface of the first member (A). A resin layer is formed to fill the gap between the first member (A) and the second member (B) defined by the spacer, and the two members are bonded via the resin layer. In other words, the portion of the gap between the first member (A) and the second member (B) where the pillars exist does not qualify as a "resin layer." If the "resin layer" were to be viewed alone, it would have numerous holes (or recesses). However, when the integrally molded product is viewed as a whole, it can be recognized as a substantially uniform layer. Therefore, in this specification, the portion occupied by the resin bonding the two members is referred to as a "resin layer."

[0011] Figure 1 is a cross-sectional schematic diagram of one embodiment of an integrally molded product having a spacer composed of truncated pyramidal pillars on the surface of a first component (A). In this specification, unless otherwise specified, the "cross section" of the integrally molded product or the first component (A) refers to a cross section obtained by cutting the first component (A) along a plane perpendicular to the surface (particularly the bonding surface with the second component (B)) of the first component (A) and passing through the vertices of the pillars. In the embodiment of Figure 1, the pillars have a truncated pyramidal pillar shape, and therefore the vertices of the pillars are considered to be the center points of the upper surfaces.

[0012] In the embodiment shown in FIG. 1, the top surfaces of the pillars 4 formed on the surface of the first member (A) 1 are in contact with the surface of the second member (B) 2. That is, the pillars 4 support the second member (B). This defines the distance between the first member (A) and the second member (B) at their joining surfaces. That is, the pillars 4 function as spacers between the two members. The resin layer 3 fills the space defined by the height of the pillars 4, thereby joining the first member (A) and the second member (B) via the resin layer 3. The resin layer 3 is a layer formed from a welding layer, adhesive, or the like, which will be described later.

[0013] Here, "the second member (B) is supported by a spacer" typically refers to a state in which the apex of a column is in direct contact with the second member (B), as shown in Figure 1, but the apex of the column may also be in contact with the second member (B) via a thin resin layer or the like, as long as it fulfills the function of defining the distance between the first member (A) and the second member (B) at the joining surface. Although not particularly limited, for example, when the distance T from the apex of the column to the surface of the second member (B) and the height H of the column (described later) satisfy the relationship 0≦T≦0.05H in the cross section of the integrally molded product, it can be determined that the second member (B) is supported by a spacer.

[0014] The first member (A) is a member made of fiber reinforced resin.

[0015] Examples of reinforcing fibers contained in the fiber-reinforced resin constituting the first member (A) include glass fibers, carbon fibers, metal fibers, aromatic polyamide fibers, polyaramid fibers, alumina fibers, silicon carbide fibers, boron fibers, and basalt fibers. These may be used alone or in combination of two or more types as appropriate. These reinforcing fibers may be surface-treated. Surface treatments include metal deposition treatment, treatment with a coupling agent, treatment with a sizing agent, and treatment with an additive. These reinforcing fibers also include conductive reinforcing fibers. Carbon fibers are preferably used as reinforcing fibers because of their low specific gravity, high strength, and high elastic modulus. Commercially available carbon fibers include "TORAYCA (registered trademark)" T800G-24K, "TORAYCA (registered trademark)" T800S-24K, "TORAYCA (registered trademark)" T700G-24K, "TORAYCA (registered trademark)" T700S-24K, "TORAYCA (registered trademark)" T300-3K, and "TORAYCA (registered trademark)" T1100G-24K (all manufactured by Toray Industries, Inc.).

[0016] Examples of the form of the reinforcing fibers in the fiber-reinforced resin include continuous fiber forms such as strands composed of multiple filaments, cloths such as plain weave, satin weave, and twill weave composed of these strands, strands in which multiple filaments are arranged in one direction (unidirectional strands), and unidirectional cloths composed of these unidirectional strands. Note that "continuous fiber" refers to linear fibers having a length of 10 mm or more, preferably fibers having a length from one end of the first component (A) to the opposite end. From the viewpoint of exhibiting high mechanical properties, such continuous fiber forms of reinforcing fibers are preferred. Alternatively, the reinforcing fibers may have a fiber dispersion form in which strands and / or single fibers are dispersed in a planar pattern, such as a chopped strand mat, a papermaking mat, a carding mat, or an airlaid mat. From the viewpoint of shape-forming ability, such fiber dispersion forms are preferred.

[0017] The matrix resin of the fiber-reinforced resin constituting the first member (A) may be a thermosetting resin, a thermoplastic resin, or a mixture thereof. It is preferable to use a thermosetting resin as the matrix resin, since this can suppress deformation of the columnar bodies (described later) even when the integrally molded product is heated and joined. Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenolic resins, polyimide resins, cyanate ester resins, bismaleimide resins, benzoxazine resins, copolymers or modified products thereof, and resins obtained by blending at least two of these resins. To improve impact resistance, an elastomer or rubber component may be added to the thermosetting resin. Examples of thermoplastic resins include polyamides such as polyamide 6 and polyamide 66, polyarylene ether ketones such as polyether ketone, polyether ether ketone and polyether ketone ketone, polyolefins such as polyethylene, polypropylene and polybutylene, styrene-based resins, polyarylene sulfides such as polycarbonate and polyphenylene sulfide, polyimide, polyetherimide, polyethersulfone, etc. These thermoplastic resins may be copolymers or modified products of the above-mentioned resins, and / or resins in which two or more types are blended.

[0018] The height H of the columns of the first component (A) is 50 μm or more and 5000 μm or less. The height H of the columns is more preferably 75 μm or more, and even more preferably 100 μm or more. If the height H of the columns is too low, the resin layer becomes too thin and sufficient mechanical properties cannot be exhibited. On the other hand, if the height H of the columns is too high, it becomes difficult to form the columns by integral molding. Therefore, the height H of the columns is preferably 1000 μm or less, more preferably 750 μm or less, and even more preferably 500 μm or less.

[0019] If the first component (A') does not have enough columns, the columns may be compressed and deformed when the second component (B') is pressed against the first component (A') during bonding. Therefore, in the present invention, the ratio of the projected area of ​​the columns to the bonding area between the first component (A) and the second component (B) (hereinafter referred to as the "projected area ratio") is set to 5% or more, preferably 10% or more, and more preferably 15% or more. If the columns are compressed and deformed, the resin layer will be thinner than the target thickness. On the other hand, if the projected area of ​​the columns is too large, the amount of resin constituting the resin layer will decrease, which may significantly reduce the bonding strength. Therefore, the projected area ratio of the columns is set to 50% or less. Here, the bonding area refers to the area of ​​the region (bonding surface) where the first component (A) and the second component (B) are bonded via the resin layer (at least partially supported by the columns). The projected area of ​​the columns is the sum of the areas of the regions defined by the outer edges of the columns in the bonding surface when the first component (A) is viewed from directly above. Figure 2(a) is a cut-out view of a part of the first member (A) on which quadrangular pyramidal truncated pillars are formed. Figure 2(b) is a top view of the first member (A) in Figure 2(a). The area occupied by the base of the quadrangular pyramid, shown with diagonal lines in the figure, is the projected area of ​​each pillar.

[0020] If the width of the pillars is small, they may be deformed when the second component (B) is joined. Therefore, the minimum width (Lmin) of the pillars is 0.05 mm or more, preferably 0.1 mm or more, more preferably 0.15 mm or more, and even more preferably 0.2 mm or more. Furthermore, if the minimum width (Lmin) is too large, it may hinder the flow of the resin or adhesive during joining. Therefore, the minimum width (Lmin) of the pillars is 10 mm or less, preferably 5 mm or less, more preferably 1 mm or less, and even more preferably 0.5 mm or less. The minimum width (Lmin) and the maximum width (Lmax) described below refer to the width of the region defined by the outer edge of the pillars, as shown in FIG. 2(a). The maximum width (Lmax) of the pillars is not particularly limited, but examples include a dot-like shape with a maximum width (Lmax) of less than 50 mm and a stripe-like shape with a maximum width (Lmax) of 50 to 5,000 mm. A dot-like shape facilitates uniform distribution across the entire joining surface. In addition, in the case of streaks, the flow path of the resin or adhesive can be easily controlled by the pillars.

[0021] When the inclination angle α (hereinafter simply referred to as "α") of the side surface of the columnar body is small, the contact area between the columnar body and the second component (B) becomes small, resulting in pressure concentration. Therefore, α is preferably 45° or more. On the other hand, when the columnar body is molded using a mold, if α is greater than 90°, the columnar body may not be able to be removed from the mold. Therefore, α is preferably 45° or more and 90° or less. Here, the inclination angle α is determined from a cross section of the first component (A) cut through the minimum width portion of the columnar body, as shown in Figure 2(c). Figure 3 shows examples of how to determine α for columns with various cross-sectional shapes. As shown in Figures 3(a) and (b), when the outline of the side surface of the columnar body (hereinafter simply referred to as "outline") is a straight line, the intersection of the outline and the base is taken as the starting point P, and the angle between the base of the columnar body and the outline is defined as α. When the outline of a column is curved, as shown in Figures 3(c) and (d), the intersection of the outline and the base is taken as the starting point P, and the angle formed by the base of the column and the line connecting the starting point P to the apex of the column is defined as α. When the outline of the side of the column is curved and has a plateau at the tip, as shown in Figure 3(d), the intersection of the outline and the base is taken as the starting point P, and the angle formed by the base of the column and the line connecting the end point of the plateau closest to the starting point P is defined as α.

[0022] To prevent uneven contact, the pillars are preferably distributed over the entire joining surface. Furthermore, the pillars are preferably arranged periodically, i.e., at a constant pitch, on the surface of the first component (A) that serves as the joining surface. For example, when the pillars are arranged in a dot pattern, they may be arranged in a grid pattern with a constant pitch, or in a staggered pattern with a constant pitch. Furthermore, when the pillars are arranged in a stripe pattern, they may be arranged in a unidirectional pattern with a constant pitch, or in a mesh pattern with a constant pitch both vertically and horizontally.

[0023] The material of the second member (B) is not limited, but in the present invention, the second member (B) is joined in a state where it is supported by the pillars of the first member (A), and the pillars function as spacers to control the thickness of the resin layer. Therefore, it is preferable that the second member (B) is a member that is rigid and difficult to deform. From this perspective, it is preferable that the second member (B) is a member made of at least one material selected from fiber-reinforced resin, metal, and wood. Furthermore, if the second member (B) is a fiber-reinforced resin, it is preferable that it is a fiber-reinforced resin because the resin contained in the fiber-reinforced resin allows it to be joined without using adhesives or the like.

[0024] In order to allow the columns of the first component (A) to function as spacers, the joining surface of the second component (B) is preferably smooth. The smoothness of the joining surface can be determined, for example, by the roughness-average height Rc measured according to JIS B0601 (2013) being 10 μm or less.

[0025] In the integrally molded product of the present invention, a first member (A) and a second member (B) are bonded together via a resin layer. Such a resin layer is typically formed from the resin contained in each member before bonding, or from an additional adhesive. Each embodiment will be described below, but in all embodiments, the porosity of the resin layer is preferably 10% or less. If the porosity is high, destruction is likely to progress from the voids, which may result in a decrease in bonding strength. On the other hand, although there is no particular lower limit for the porosity, when forming a resin layer as described above, it is generally difficult to achieve a porosity of 0.1% or less.

[0026] (First embodiment) In the first embodiment, either the first member (A') or the second member (B'), or both, contain a thermoplastic resin before joining. The thermoplastic resin melts during joining to form a resin layer, and the two members are joined via the resin layer. That is, the second member (B) is supported by the spacer of the first member (A) and is heat-welded to the first member (A) via the resin layer. In this case, the heat-welding method is not particularly limited, but examples include hot plate welding, ultrasonic welding, vibration welding, laser welding, resistance welding, and induction welding.

[0027] The first member (A') used in this embodiment may be a member such as that shown in FIG. 4. FIG. 4(a) shows the configuration of the first member (A') in which a thermoplastic resin welding layer is present on the surface of a thermosetting fiber-reinforced resin material. FIG. 4(b) shows the configuration of the first member (A') before welding, in which a thermoplastic resin welding layer with a lower melting point (when the welding layer is a crystalline resin) or a lower glass transition temperature (when the welding layer is an amorphous resin) than the deflection temperature under load of the main body (portion excluding the welding layer) of the first member (A) is present on the surface of the thermoplastic fiber-reinforced resin material. In either case, the thermoplastic resin welding layer can be melted to form a resin layer for bonding. Since the columnar body of the first member (A) has a higher heat resistance than the welding layer, deformation can be suppressed during bonding by welding.

[0028] Moreover, the second member (B) may also be a member having a welding layer 7 on the surface of the main body portion 11, as shown in FIG. 4(c) or FIG. 4(d).

[0029] In this embodiment, the resin of the main body portions of the first member (A') and the second member (B') is preferably a thermosetting resin from the viewpoint of shape stability during heating. Alternatively, when the main body portion is a thermoplastic resin, the main body portion is preferably a resin that does not deform at the melting temperature of the thermoplastic resin of the welding layer. Specifically, it is preferable that the heat deflection temperature of the thermoplastic resin of the main body portion is higher than the melting point when the thermoplastic resin of the welding layer is a crystalline resin, or higher than the glass transition temperature when the resin of the welding layer is an amorphous resin. The heat deflection temperature here is a value based on Method B of JIS K 7191. The melting point and the glass transition temperature are values based on JIS K 7121 (2012) and are based on a differential scanning calorimeter (DSC). By setting such a relationship, it is possible to suppress deformation around the portions that come into contact with the columnar bodies of the first member (A') or the columnar bodies of the second member (B') during heat welding.

[0030] By overlapping and heat-welding such first member (A') and second member (B') as shown in FIG. 5, it is possible to perform welding without deforming the main body portions of the first member (A') and the second member (B'). And the resin layer can be made to have an accurate thickness, that is, a thickness approximated to the height H of the columnar body.

[0031] As a manufacturing method of the first member (A') shown in FIG. 4(a), a preform is produced by laminating a thermoplastic resin film on the surface of an uncured thermosetting prepreg, and a mold having an uneven structure corresponding to the columnar body 6 is arranged on the thermoplastic resin film side, and heating and pressurization are performed at a temperature below the melting point of the thermoplastic resin film using an autoclave or a press machine, etc., and the curing of the prepreg, the forming of the columnar body, and the formation of the welding layer are performed simultaneously. Also, as a manufacturing method of the first member (A') shown in FIG. 4(b), a thermoplastic prepreg and, if necessary, a thermoplastic resin film of the same kind of resin as the thermoplastic prepreg are laminated, and heating and pressurization are performed using a mold having an uneven structure corresponding to the shape of the columnar body 9 to integrate the prepreg and form the columnar body, and then a thermoplastic resin film with a low softening point is laminated and heated and pressurized to form a welding layer made of a thermoplastic resin with a low softening point.

[0032] (Second embodiment) In the second embodiment, the second member (B') contains an uncured thermosetting resin, and the thermosetting resin flows during bonding to form a resin layer. Specifically, a preform formed by laminating thermosetting prepregs and, if necessary, disposing an uncured thermosetting resin film on the surface is used as the second member (B'). This preform is then superimposed on the first member (A') as shown in FIG. 6, and heated and pressurized, thereby curing the thermosetting resin contained in the second member (B) simultaneously with bonding. The method of applying heat and pressure in this case is not particularly limited, but examples include autoclave molding, press molding, and oven molding.

[0033] In this embodiment, a resin layer is formed in the second component (B') by utilizing the fact that the layer of the resin alone has higher fluidity than the layer containing reinforcing fibers. If the pressure during bonding is too high, the columns of the first component (A) will be embedded in the second component (B). Therefore, the pressure during bonding is preferably 1 MPa or less, and more preferably 0.8 MPa or less. Furthermore, if the pressure during bonding is too low, the thermosetting resin may not flow sufficiently, resulting in poor bonding. Therefore, the pressure is preferably 0.2 MPa or more.

[0034] Furthermore, in order to simultaneously perform heating and bonding, the resin of the first component (A') is preferably made of a cured thermosetting resin or a thermoplastic resin with a softening point higher than the heating temperature during bonding, and a cured thermosetting resin is particularly preferred in terms of shape stability during heating.

[0035] (Third embodiment) In the third embodiment, an adhesive is applied to the joining surfaces of the first member (A') and the second member (B'), and the adhesive serves as a resin layer. Specifically, as shown in Fig. 7, an adhesive 17 is placed between the second member (B') and the first member (A'), and they are then superimposed and joined. The adhesive is not particularly limited, but examples include thermosetting adhesives such as phenolic, epoxy, unsaturated polyester, polybenzimidazole, acrylic (SGA), resorcinol, urea, acrylic diester, silicone, and melamine; thermoplastic adhesives such as polyamide, acrylic (PMMA), polyurethane, unsaturated polyester, cellulose acetate, nitrocellulose, polyvinyl chloride, polyvinyl acetate, polyvinyl alcohol, and polyvinyl acetal; elastomeric adhesives such as polysulfide, silicone rubber, urethane rubber, recycled rubber, butadiene-styrene rubber (SBR), chloroprene rubber, nitrile rubber, butyl rubber, and silicone rubber; and natural adhesives such as starch, casein, rosin, shellac, asphalt, and natural rubber. The bonding method can be selected depending on the adhesive; for example, in the case of thermosetting adhesives, known methods such as autoclave molding and oven molding can be used. [Example]

[0036] The present invention will be described in more detail below with reference to examples. First, the evaluation methods used in the present invention will be described below.

[0037] 1. Evaluation Method (Evaluation method 1) Cross-sectional observation of integrally molded product The resin layer of the integrally molded product was evaluated by cross-sectional observation using a laser microscope. The integrally molded product was embedded and fixed in resin so that the fiber direction of the layer adjacent to the resin layer was parallel to the observation surface, and then the cross-section was polished and observed. Observations were performed in 10 fields of view, and the thickness of the resin layer was measured at three random points in each of the 10 fields of view, and the average value was used as the resin layer thickness of the bonded product. In addition, the CV value at this time was used to evaluate the variation in the thickness of the resin layer. In this case, the resin layer was measured as the part of the resin itself that did not contain reinforcing fibers, etc. In addition, in the cross-sectional observation of each of the 10 fields of view, the area of ​​the voids and resin layer were measured, and the porosity was measured in each field of view, and the average of the 10 fields of view was used as the porosity of the resin layer.

[0038] (Evaluation method 2) X-ray CT observation of the integrally molded product The dimensions and projected area of ​​the pillars in the integrally molded product were evaluated using X-ray CT. A cross section in the thickness direction passing through the top surface of the pillar was observed, and the height (H) and inclination angle of the pillar were measured. The maximum width (Lmax), minimum width (Lmin), and projected area of ​​the pillar were also measured by observing a cross section in the in-plane direction passing through the bottom surface of the pillar. The height (H), tilt angle, maximum width (Lmax), and minimum width (Lmin) of the pillars were taken as the average values ​​of the measured pillars.

[0039] (Evaluation method 3) Cross-sectional observation of the first component (A') before joining The height of the columns of the first member (A') was measured by cross-sectional observation using a laser microscope. The first member (A') was embedded and fixed in resin so that the thickness direction could be observed, and then the cross section was polished to a position that passed through the top surface of the columns, and the cross section was observed. Measurements were performed at 10 locations, and the height of the columns was measured in each field of view, and the average value was taken as the height of the columns.

[0040] 2.Material (reinforced fiber) A polymer containing polyacrylonitrile as the main component was spun and calcined to obtain continuous carbon fibers with a total of 12,000 filaments. The continuous carbon fibers were then subjected to electrolytic surface treatment and dried in heated air at 120°C to obtain carbon fibers. The properties of the carbon fibers were as follows:

[0041] Density: 1.80g / cm 3 Single fiber diameter: 7 μm Tensile strength: 4.9GPa Tensile modulus: 230GPa (thermosetting resin film) 50 parts by mass of bisphenol A epoxy resin ("jER" (registered trademark) 825 (manufactured by Mitsubishi Chemical Corporation)), 50 parts by mass of tetraglycidyldiaminodiphenylmethane ("Sumiepoxy" (registered trademark) ELM434 (manufactured by Sumitomo Chemical Co., Ltd.)), and 8 parts by mass of polyethersulfone ("Sumikaexcel" (registered trademark) PES5003P (manufactured by Sumitomo Chemical Co., Ltd.)) were added and mixed under heat to dissolve the polyethersulfone. Next, while continuing to mix, the temperature was lowered to 100°C or less, and 45 parts by mass of 4,4'-diaminodiphenylsulfone (Seikacure S (manufactured by Wakayama Seika Kogyo Co., Ltd.)) was added and stirred to obtain a thermosetting resin. The obtained thermosetting resin was coated onto release paper using a knife coater to produce a thermosetting resin film.

[0042] (thermosetting prepreg) The carbon fibers are aligned in one direction and drawn out as a continuous reinforced fiber sheet, with a weight of 190 g / m 2 The thermosetting resin film was superimposed on both sides of the unidirectionally aligned reinforcing fiber sheet so that the carbon fiber content was 65% by mass (Wf), and the thermosetting resin film was impregnated into the reinforcing fiber sheet while applying heat and pressure using a heat roll set at 60°C, thereby obtaining a thermosetting prepreg.

[0043] (thermoplastic resin film) A thermoplastic resin sheet (PA-1) was produced using "Amilan (registered trademark)" CM1017 (manufactured by Toray Industries, Inc., melting point 225°C, deflection temperature under load 190°C) as a PA resin.

[0044] Furthermore, a thermoplastic resin film (PA-2) was produced using "Amilan (registered trademark)" CM4000 (manufactured by Toray Industries, Inc., terpolymer polyamide resin, melting point 155°C) as a low-melting-point PA resin.

[0045] (thermoplastic prepreg) The carbon fibers are aligned in one direction and drawn out as a continuous reinforced fiber sheet, weighing 131 g / m 2 The basis weight was adjusted so that the thermoplastic resin film (PA-1) was placed on both sides of the reinforcing fiber sheet, heated with an IR heater set at 270°C to melt the resin, and adhered to the entire surface of the reinforcing fiber sheet. The sheet was then pressed and cooled with nip rolls whose surface temperature was maintained at 100°C, yielding a thermoplastic prepreg that would serve as a precursor to the thermoplastic resin layer. The basis weight of the thermoplastic resin was 87 g / m 2 It was decided.

[0046] (metal plate) An aluminum alloy A5052 (thickness: 1.5 mm) was prepared as the metal plate. The surface was polished with sandpaper (grit #400) and surface dirt was removed with acetone before use.

[0047] 3. Fabrication of integrated molded product Example 1 [Preparation of first member (A')-1] Eight rectangular sheets measuring 100 mm x 50 mm were cut out from the prepared thermosetting prepreg and one from a 150 μm thick thermoplastic resin sheet (PA-1). The direction of the long side of the rectangular cut sheet was set to 0°, and the fiber direction was set to [0° / 90°]. 2S Eight prepregs were laminated so that the thickness was as follows: Furthermore, one thermoplastic resin film (PA-1) was laminated on the surface to obtain a preform.

[0048] Next, the preform was heated in an autoclave at 180°C for 2 hours while applying a surface pressure of 0.6 MPa to harden the thermosetting resin, thereby obtaining a first component (A')-1. At this time, the Al plate with the recesses was placed on the thermoplastic resin film (PA-1) side. On the surface of the first component (A')-1, pillars with a square truncated pyramid shape (height 270 μm, base approximately 2 mm square with a 70° inclination angle) as shown in FIG. 8(b) were formed in a dot pattern with a 4 mm pitch as shown in FIG. 8(a). The thickness of the flat region other than the pillars was 1.5 mm, and the surface had a welding layer made of the thermoplastic resin film (PA-1).

[0049] [Preparation of second member (B')-1] The second member (B')-1 was produced in the same manner as the first member (A')-1, except that a smooth Al plate was used for autoclave molding. The second member (B')-1 was 1.5 mm thick and had a welding layer made of a thermoplastic resin film (PA-1) on its surface. Furthermore, since a smooth Al plate was used for molding, the surface was smooth.

[0050] [Production of integrated molded products] The first member (A')-1 and the second member (B')-1 were overlapped with the sides having the welding layer facing each other and secured with polyimide tape. The overlapping first member (A')-1 and second member (B')-1 were sandwiched between polyimide films and heat-welded by applying pressure of 1 MPa for 6 minutes in a press heated to 240°C to obtain an integrated molded product. The state of the columns and resin layer of the resulting bonded integrally molded product is shown in Table 1 (the same is shown in Tables 1 and 2 for the following examples). In the resulting integrated molded product, the columns of the first member (A)-1 served as spacers to support and bond the second member (B)-1, and a resin layer derived from the thermoplastic resin film (PA-1) was formed, roughly corresponding to the height of the columns of the first member (A')-1. Furthermore, the results showed significantly reduced variation in the thickness of the resin layer.

[0051] Example 2 [Preparation of first member (A')-2] The first component (A')-2 was fabricated in the same manner as the first component (A')-1, except that the shape of the columns was changed by changing the Al plate with recesses used in fabricating the first component (A')-1. The resulting first component (A')-2 had square pyramidal columns (height 270 μm, base approximately 2 mm square, inclination angle 30°) arranged at a 4 mm pitch in a dot pattern as shown in Figure 8(a) on the resulting first component (A')-2.

[0052] [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 1, except that the first member (A')-2 was used instead of the first member (A')-1. In the obtained integrally molded product, the columns of the first member (A)-2 served as spacers to support and bond the second member (B)-1. Furthermore, the results showed significantly small variations in the thickness of the resin layer. However, compressive deformation of the columns was observed after bonding, and a slight discrepancy was observed between the height of the columns and the thickness of the resin layer before bonding.

[0053] Example 3 [Production of first member (A)-3] The first component (A')-3 was fabricated in the same manner as the first component (A')-1, except that the shape of the columns was changed by changing the Al plate with recesses used in fabricating the first component (A')-1. The resulting first component (A')-3 had columns of ridged truncated pyramids (270 μm in height, with a rectangular base measuring approximately 2 × 50 mm on each side and an inclination angle of 70°) formed in stripes at an 8 mm pitch as shown in Figure 9(a).

[0054] [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 1, except that the first member (A')-3 was used instead of the first member (A)-1. In the obtained integrally molded product, the pillars of the first member (A)-3 served as spacers to support and bond the second member (B)-1, and a resin layer derived from the thermoplastic resin film (PA-1) was formed, the height of which roughly corresponded to the height of the pillars of the first member (A')-3. Furthermore, the variation in the thickness of the resin layer was significantly small.

[0055] Example 4 [Preparation of first member (A')-4] The first member (A')-4 was produced in the same manner as the first member (A')-1, except that the thickness of the thermoplastic resin film (PA-1) used in producing the first member (A')-1 was 75 μm.

[0056] [Preparation of second member (B')-2] The second member (B')-2 was produced in the same manner as the second member (B')-1, except that the thickness of the thermoplastic resin film (PA-1) used in producing the second member (B')-1 was 75 μm.

[0057] [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 1, except that the first member (A')-4 and the second member (B')-2 were used instead of the first member (A')-1 and the second member (B')-1. In the obtained integrally molded product, the pillars of the first member (A)-4 served as spacers to support and bond the second member (B)-2, and a resin layer was formed that roughly corresponded to the height of the pillars of the first member (A')-4. Furthermore, the variation in the thickness of the resin layer was significantly small.

[0058] Example 5 [Preparation of first member (A')-5] Ten 100mm x 50mm rectangular sheets were cut from the prepared thermoplastic prepreg and one 100μm thick thermoplastic resin film (PA-1). The rectangular cut sheets were laminated so that the long sides were oriented at 0° and the fiber direction was [0 / 90 / 0 / 90 / 0 / 0 / 90 / 0 / 90 / 0]. A single thermoplastic resin film (PA-1) was then laminated on the surface to obtain a preform. The preform was placed in a closed mold with a recess on one side, with the side containing the thermoplastic resin film (PA-1) facing the recessed side, and heated for 20 minutes at a pressure of 3MPa in a press heated to 240°C. The mold was then transferred to a press heated to 100°C and pressed for 10 minutes at a pressure of 5MPa to obtain a laminate. The resulting laminate had regular square pyramidal pillars on one side. Next, a thermoplastic resin film (PA-2) was placed on the surface of the resulting laminate with the columns. The laminate was then placed in a closed mold with a recess on one side, with the side with the thermoplastic resin film (PA-2) facing the recessed side, and heated at 180°C for 20 minutes at 1 MPa in a press. The mold was then transferred to a press heated to 100°C and pressed at 1 MPa for 10 minutes to obtain the first component (A')-5. The first component (A')-5 had columns on its surface, and cross-sectional observation revealed that the columns, as shown in Figure 8(b), were in the shape of a square truncated pyramid (270 μm high, a square base with approximately 2 mm sides and a 70° inclination), formed in a dot pattern with a 4 mm pitch, as shown in Figure 8(a). The flat area outside the columns was 1.5 mm thick, and had a welded layer formed from the thermoplastic resin film (PA-2) on the surface.

[0059] [Preparation of second member (B')-3] A second member (B')-3 was produced in the same manner as the second member (B)-1, except that the thermoplastic resin film (PA-2) was used instead of the thermoplastic resin film (PA-1) used in the production of the second member (B')-1. The second member (B')-3 had a thickness of 1.5 mm and had a welding layer made of the thermoplastic resin film (PA-2) on its surface.

[0060] [Production of integrated molded products] The first member (A')-5 and the second member (B')-3 were placed side-by-side with the welding layers facing each other and secured with polyimide tape. The overlapping first member (A')-5 and second member (B')-3 were sandwiched between polyimide films and heat-welded by applying a pressure of 1 MPa for 6 minutes in a press heated to 180°C to produce an integrated molded product. In the resulting integrated molded product, the columns of the first member (A)-5 served as spacers to support and bond the second member (B)-3, forming a resin layer derived from the thermoplastic resin film (PA-2) that roughly corresponded to the height of the columns of the first member (A')-5. Furthermore, the thickness variation of the resin layer was significantly reduced.

[0061] Example 6 [Preparation of first member (A')-6] The first component (A')-6 was fabricated in the same manner as the first component (A')-1, except that the thickness of the thermoplastic resin film (PA-1) used in fabricating the first component (A')-1 was changed from 150 μm to 300 μm. The first component (A')-6 had pillars on its surface, as shown in Figure 8. Cross-sectional observation revealed that the pillars, each shaped like a square truncated pyramid (270 μm high, with a square base measuring approximately 2 mm on each side and a 70° inclination angle), as shown in Figure 8(b), were formed in a dot pattern at a 4 mm pitch, as shown in Figure 8(a). The flat area other than the pillars had a thickness of 1.5 mm, and had a welding layer formed from the thermoplastic resin film (PA-1) on its surface.

[0062] [Preparation of second member (B')-4] Ten rectangular sheets measuring 100 mm x 50 mm were cut from each of the prepared thermoplastic prepregs. The rectangular sheets were laminated so that the long sides were oriented at 0° and the fiber orientation was [0 / 90 / 0 / 90 / 0 / 0 / 90 / 0 / 90 / 0]. The sheets were then placed in a closed mold with a smooth surface and heated at 240°C for 20 minutes at a pressure of 3 MPa. The mold was then transferred to a press heated to 100°C and pressed at 5 MPa for 10 minutes to produce the second component (B')-4.

[0063] [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 1, except that the first member (A')-6 and the second member (B')-4 were used instead of the first member (A')-1 and the second member (B')-1. In the obtained integrally molded product, the pillars of the first member (A)-6 served as spacers to support and bond the second member (B)-4, resulting in little variation in the thickness of the resin layer. However, after bonding, as shown in Figure 10, the pillars were embedded in the second member (B)-4, and a slight discrepancy was observed between the height of the pillars before bonding and the thickness of the resin layer.

[0064] Example 7 [Preparation of first member (A')-7] The first component (A')-7 was fabricated in the same manner as the first component (A')-1, except that the thermoplastic resin film (PA-1) used in fabricating the first component (A')-1 was replaced with a thermoplastic resin film (PA-2). The surface of the first component (A')-7 had a square pyramidal truncated columnar structure (270 μm high, a square base with sides of approximately 2 mm and a 70° inclination angle) formed in a dot pattern at a 4 mm pitch, as shown in Figure 8. The flat area of ​​the first component (A')-7 other than the columnar structures was 1.5 mm thick, and the surface had a welding layer made of the thermoplastic resin film (PA-2).

[0065] [Preparation of second member (B')-5] Ten 100mm x 50mm rectangular sheets were cut out from the prepared thermoplastic prepreg and one 100μm thick thermoplastic resin film (PA-2). The rectangular cut sheets were laminated so that the long sides were oriented at 0° and the fiber direction was [0 / 90 / 0 / 90 / 0 / 0 / 90 / 0 / 90 / 0], and one thermoplastic resin film (PA-2) was laminated on the surface to obtain a preform. The preform was placed in a closed mold with a smooth surface and heated at 3MPa for 20 minutes in a press heated to 240°C. The mold was then transferred to a press heated to 100°C and pressed at 5MPa for 10 minutes to produce the second member (B')-5.

[0066] [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 5, except that the first member (A')-7 and the second member (B')-5 were used instead of the first member (A')-5 and the second member (B')-3. In the obtained integrally molded product, the pillars of the first member (A)-7 served as spacers to support and bond the second member (B)-5, and a resin layer derived from the thermoplastic resin film (PA-2) was formed, the height of which roughly corresponded to the height of the pillars of the first member (A')-7. Furthermore, the variation in the thickness of the resin layer was significantly small.

[0067] Example 8 [Preparation of first member (A')-8] Eight rectangular sheets measuring 100 mm x 50 mm were cut out from the prepared thermosetting prepreg. The direction of the long side of the rectangular cut sheet was set to 0°, and the fiber direction was set to [0° / 90°]. 2SEight prepregs were laminated to obtain a preform. Next, the preform was heated in an autoclave at 180°C for 2 hours while applying a surface pressure of 0.6 MPa to harden the thermosetting resin, thereby obtaining the first component (A')-8. An Al plate with a recess was placed on one side during molding. On the surface of the first component (A')-8, pillars with a square truncated pyramidal shape (height 350 μm, base approximately 2 mm square, inclination angle 70°) as shown in Figure 8(b) were formed in a dot pattern at a 4 mm pitch as shown in Figure 8(a). The thickness of the flat region of the first component (A')-8 other than the pillars was 1.4 mm.

[0068] [Preparation of second member (B')-6] Eight rectangular sheets measuring 100 mm x 50 mm were cut out from the prepared thermosetting prepreg and one from the 400 μm thick thermosetting resin film. The direction of the long side of the rectangular cut sheet was set to 0°, and the fiber direction was set to [0° / 90°]. 2S Eight prepregs were laminated so as to form a sheet having a thickness of 400 μm, and a thermosetting resin film having a thickness of 400 μm was laminated on the surface of the sheet to obtain a second member (B′)-6.

[0069] [Production of integrated molded products] The first component (A')-8 and the second component (B')-6 were stacked so that the side of the first component (A')-8 bearing the columnar bodies contacted the side of the second component (B')-6 bearing the thermosetting resin film. The components were then heated in an autoclave at 180°C for 2 hours under a surface pressure of 0.6 MPa to cure the second component (B')-6 and bond the first component (A')-8 and the second component (B')-6 together, yielding an integrated molded product. The resulting integrated molded product was bonded while the columnar bodies of the first component (A)-8 served as spacers to support the second component (B)-6. Furthermore, the thickness of the resin layer showed minimal variation. However, after bonding, the columnar bodies were embedded in the second component (B)-6, as shown in Figure 10, and a discrepancy was observed between the height of the columnar bodies and the thickness of the resin layer before bonding.

[0070] Example 9 [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 6, except that the aluminum alloy A5052 was used instead of the second member (B')-4. The resulting integrally molded product was joined while supporting the A5020, with the pillars of the first member (A)-6 acting as spacers. A resin layer derived from the thermoplastic resin film (PA-1) was formed, roughly corresponding to the height of the pillars of the first member (A')-6 before joining. Furthermore, the variation in the thickness of the resin layer was significantly reduced.

[0071] Example 10 [Preparation of second member (B')-7] Eight rectangular sheets measuring 100 mm x 50 mm were cut out from the prepared thermosetting prepreg. The direction of the long side of the rectangular cut sheet was set to 0°, and the fiber direction was set to [0° / 90°]. 2S Eight prepregs were laminated to obtain a preform. Next, the preform was heated in an autoclave at 180°C for 2 hours while applying a surface pressure of 0.6 MPa to cure the thermosetting resin, thereby obtaining a second member (B')-7.

[0072] [Production of integrated molded products] The first component (A')-8 and the second component (B')-7 were placed with the side of the first component (A')-8 bearing the columns facing the second component (B')-7. A structural adhesive film ("Scotch-Weld Structural Adhensive Film AF-555M" (3M)) was inserted between the first component (A')-8 and the second component (B')-7 to a thickness of approximately 400 μm. The components were then stacked together and heated in an autoclave at 180°C for 2 hours under a surface pressure of 0.6 MPa to produce an integrated molded product. The resulting integrated molded product was bonded to the second component (B)-7, with the columns of the first component (A')-8 acting as spacers to support the second component (B'). A resin layer derived from the adhesive film was formed, roughly corresponding to the height of the columns of the first component (A')-8. Furthermore, the thickness variation of the resin layer was significantly reduced.

[0073] Example 11 [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 10, except that the aluminum alloy A5052 was used instead of the second member (B')-7. The obtained integrally molded product had the A5020 supported and bonded to the first member (A)-8 using the columnar bodies as spacers, and a resin layer derived from the adhesive film was formed that roughly corresponded to the height of the columnar bodies of the first member (A')-8. Furthermore, the variation in the thickness of the resin layer was significantly small.

[0074] (Comparative Example 1) [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 1, except that a second member (B')-1 was used instead of the first member (A')-1, and neither member had a columnar body. Since the obtained integrally molded product had no columnar bodies in any of the members, the thickness of the resin layer varied greatly.

[0075] (Comparative Example 2) [Preparation of first member (A')-9] The first component (A')-9 was fabricated in the same manner as the first component (A')-1, except that the pitch of the columns was changed by changing the Al plate with recesses used in fabricating the first component (A')-1. The resulting first component (A')-9 had columns of the shape of regular square truncated pyramids (270 μm in height, a square base with sides of approximately 2 mm and an inclination angle of 70°) formed in a dot pattern at a pitch of 10 mm.

[0076] [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 1, except that the first member (A')-9 was used instead of the first member (A')-1. The obtained integrally molded product had a wide pitch of the columns of the first member (A')-9 and a small projected area of ​​the columns, so the columns were damaged during bonding. As a result, the thickness of the resin layer varied greatly.

[0077] (Comparative Example 3) [Production of first member (A')-10] The first component (A')-10 was fabricated in the same manner as the first component (A')-1, except that the height of the columns was changed by changing the Al plate with recesses used in fabricating the first component (A')-1. The resulting first component (A')-10 had columns of regular square pyramid shape (height 40 μm, base shaped like a square with sides of approximately 2 mm and an inclination angle of 70°) formed in a dot pattern at a 4 mm pitch.

[0078] [Production of integrated molded products] An integrally molded product was produced in the same manner as in Example 1, except that the first member (A')-10 was used instead of the first member (A')-1. The obtained integrally molded product had a large variation in the thickness of the resin layer because the height of the columnar bodies of the first member (A)-10 was low.

[0079] [Table 1]

[0080] [Table 2] [Explanation of symbols]

[0081] 1: First member (A) 2: Second member (B) 3: Resin layer 4: Pillar (spacer) 5: First member (A') made of thermosetting resin 6: Pillar body made of thermosetting resin 7: Welding layer made of thermoplastic resin 8: First member (A') made of thermoplastic resin 9: Pillar body made of thermoplastic resin 10: Welding layer made of low-melting point thermoplastic resin 11: Second member (B') made of thermosetting resin 12: Second member (B') made of thermoplastic resin 13: First member (A') 14: Second member (B') 15: Second member (B') made of uncured prepreg 16: Uncured thermosetting resin film 17: Adhesive

Claims

1. An integrally molded product in which a first member (A) made of a fiber-reinforced resin having a spacer on its surface and a second member (B) supported by the spacer are joined via a resin layer, wherein the spacer is composed of a plurality of pillars having a height of 50 to 5000 μm and a minimum width of 0.05 to 10 mm, and the projected area of ​​the pillars on the joining surface between the first member (A) and the second member (B) is 5 to 50%.

2. 2. The integrally molded product according to claim 1, wherein the pillars are periodically arranged on the surface of the first member (A).

3. The integrally molded product according to claim 2, wherein the columnar body is streaky with a maximum width of 50 to 5000 mm.

4. The integrally molded product according to claim 2, wherein the pillars are dot-shaped with a maximum width of less than 50 mm.

5. The integrally molded product according to any one of claims 1 to 4, wherein the inclination angle of the side surface of the columnar body is 45 to 90 degrees.

6. The integrally molded product according to any one of claims 1 to 4, wherein the porosity of the resin layer is 0.1 to 10% or less.

7. The integrally molded product according to any one of claims 1 to 4, wherein the resin layer is made of a thermoplastic resin.

8. The integrally molded product according to claim 7, wherein the first member (A) and / or the second member (B) is made of continuous reinforcing fibers and a thermosetting resin.

9. The integrally molded product according to claim 7, wherein the first member (A) and the second member (B) are joined by thermal welding.

10. The second member (B) is made of a thermoplastic resin, and the load deflection temperature of the thermoplastic resin of the second member (B) is higher than its melting point if the thermoplastic resin of the resin layer is a crystalline resin, or higher than its glass transition temperature if the thermoplastic resin of the resin layer is an amorphous resin. An integrally molded product according to claim 9.

11. The integrally molded product according to any one of claims 1 to 4, wherein the resin layer is made of a thermosetting resin.

12. The integrally molded product according to any one of claims 1 to 4, wherein the second member (B) is a member made of at least one selected from metal, wood, or fiber-reinforced resin, and the resin layer is an adhesive.

13. A fiber-reinforced thermosetting resin member comprising a spacer composed of a plurality of columns having a welded layer of thermoplastic resin on the surface.

14. 14. The method for producing a fiber-reinforced thermosetting resin member according to claim 13, wherein a preform having a thermoplastic resin film disposed on a surface of an uncured thermosetting prepreg is heated and pressurized at a temperature equal to or lower than the melting point of the thermoplastic resin film in a mold having an uneven structure corresponding to the columnar body.

15. A method for manufacturing an integrally molded product according to claim 9, wherein the fiber-reinforced thermosetting resin member according to claim 13 is used as a first member (A'), and the first member (A) and the second member (B') are joined by thermal welding while the second member (B') is supported by the spacer of the first member (A').

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