Molded article, laminate, and method for producing molded article

Abstract

To inhibit defects caused by portions lacking the matrix resin.SOLUTION: A molded article 1 includes a fiber-reinforced resin substrate 5 and a resin layer 25 laminated on the fiber-reinforced resin substrate 5. The fiber-reinforced resin substrate 5 includes a plurality of fibers 5c and a matrix resin 5d impregnated into the fibers 5c. The resin layer 25 has a thickness in the range of 0.5 μm or more and 300 μm or less. The resin layer 25 contains a cured resin as its main constituent. The resin layer 25 contains nanoparticles 25a.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a molded article, a laminate, and a method for manufacturing a molded article using the laminate.

Background Art

[0002] Members used in sports equipment, automobiles, ships, aircraft, etc. can be subjected to large impacts and deformation stresses. It has been proposed to use a molded article having a substrate made of a fiber-reinforced resin such as a carbon fiber-reinforced resin (CFRP) or a glass fiber-reinforced resin (GFRP) for such members. The fiber-reinforced resin is a lightweight and tough material. The fiber-reinforced resin substrate is formed by weaving fibers, impregnating them with a matrix resin, and curing the matrix resin.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a molded article having a fiber-reinforced resin substrate, grooves or holes may be formed in order to impart a desired function or design. The surface of the hole or groove becomes an end face of the molded article. At the end face, a portion where the matrix resin of the fiber-reinforced resin substrate is missing may occur. The portion where the matrix resin is missing may cause problems. The present disclosure aims to suppress problems caused by the portion where the matrix resin is missing.

Means for Solving the Problems

[0005] The molded article of the present disclosure comprises a fiber-reinforced resin substrate and a resin layer laminated on the fiber-reinforced resin substrate. The fiber-reinforced resin substrate includes a plurality of fibers and a matrix resin impregnated in the fibers and cured. The thickness of the resin layer is 0.5 μm or more and 300 μm or less. The resin layer mainly contains a cured resin. The resin layer contains nanoparticles.

Advantages of the Invention

[0006] According to the present disclosure, it is possible to suppress problems caused by portions where the matrix resin is missing.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings attached to this specification, for the convenience of illustration and easy understanding, the scale, the aspect ratio of the vertical and horizontal dimensions, etc. are appropriately changed and exaggerated from those of the actual object. In some of the drawings, the configurations shown may be omitted in other drawings.

[0009] In this specification, terms for specifying shapes, geometric conditions, and their degrees, such as "parallel", "orthogonal", "identical", etc., and values of lengths and angles are not limited to strict meanings, and are interpreted to include ranges to the extent that similar functions can be expected.

[0010] In this specification, when a plurality of upper limit value candidates and a plurality of lower limit value candidates are listed for a parameter, the parameter may be a numerical range obtained by combining any one upper limit value candidate and any one lower limit value candidate.

[0011] One embodiment of the present disclosure relates to the following [1] to

[13] . [1] A fiber-reinforced resin substrate, and a resin layer laminated on the fiber-reinforced resin substrate, wherein the fiber-reinforced resin substrate includes a plurality of fibers and a matrix resin impregnated into the fibers and cured, the thickness of the resin layer is 0.5 μm or more and 300 μm or less, the resin layer contains a resin cured product as a main component, the resin layer is a molded product containing nanoparticles. [2] A molded product including a fiber-reinforced resin substrate, and a resin layer laminated on the fiber-reinforced resin substrate, wherein the fiber-reinforced resin substrate includes a plurality of fibers and a matrix resin impregnated into the fibers and cured, at an end face of the molded product, the area of a portion where the matrix resin is missing is 3000 μm per 275 μm of the length along the extending direction of the end face2 The following is a molded article. [3] A fiber-reinforced resin substrate, and A resin layer laminated on the fiber-reinforced resin substrate, the molded article comprising: The fiber-reinforced resin substrate includes a plurality of fibers and a matrix resin impregnated in the fibers and cured, When a groove or hole is formed in the molded article along the arrangement direction of the fibers, on the end face of the molded article formed by the groove or hole, the area of the portion where the matrix resin of the fiber-reinforced resin substrate is missing is 3000 μm per 275 μm of the length along the arrangement direction of the fibers 2 The following is a molded article. [4] The thickness of the resin layer is 0.5 μm or more and 300 μm or less, the molded article according to [2] or [3]. [5] The resin layer contains a resin cured product as a main component, the molded article according to any one of [2] to [4]. [6] The resin layer contains nanoparticles, the molded article according to any one of [2] to [5]. [7] The content of the matrix resin of the fiber-reinforced resin substrate is 30% by mass or more and 40% by mass or less, the molded article according to any one of [1] to [6]. [8] A laminate for transferring a resin layer to a fiber-reinforced resin substrate, A base material layer, and A resin layer laminated on the base material layer, including: The thickness of the resin layer is 0.5 μm or more and 300 μm or less, the laminate. [9] The resin layer contains a resin cured product as a main component, the laminate according to [8].

[10] The resin layer contains nanoparticles, the laminate according to [8] or [9].

[11] A preparation step of preparing a laminate including a base material and a resin layer laminated on the base material, and A lamination step of laminating the laminate so that the resin layer is closer to the resin-impregnated fiber sheet than the base material, In the lamination step, the resin layer and the resin-impregnated fiber sheet are heated and pressed, A method for manufacturing a molded article.

[12] The method for manufacturing a molded article according to

[11] , further comprising a peeling step of peeling the base material.

[13] The method for manufacturing a molded article according to

[11] or

[12] , further comprising a forming step of forming a groove or a hole in the molded article.

[0012] [Molded article] FIG. 1 is a plan view of an example of a molded article 1 according to an embodiment of the present disclosure. The molded article 1 includes a fiber-reinforced resin substrate 5 described later. The molded article 1 has characteristics such as high rigidity, light weight, easy vibration damping, low thermal expansion, high X-ray transmittance, easy radio wave shielding, low corrosion, and easy heat dissipation. The molded article 1 is applied to various members that require these characteristics. For example, the molded article 1 is an automobile part such as a roof, hood, fender, battery case, etc., a railway vehicle part such as a vehicle bogie and seat, a pressure vessel such as a hydrogen tank and CNG tank, a medical device such as a cassette and X-ray grid, an industrial machine part such as a robot arm and a transport robot, an aircraft such as a main wing and fuselage, an artificial satellite such as a substrate for an antenna and a solar cell panel, and a sports item such as a fishing rod and a golf club.

[0013] As shown in FIG. 1, grooves 1a and holes 1b are formed in the molded article 1. The grooves 1a and holes 1b can impart a desired function to the molded article 1. For example, the grooves 1a and holes 1b enable screwing, joining, overlapping, etc. of the molded article 1, or enable the molded article 1 to be used as a filter for ventilation or filtration. Alternatively, a design may be imparted to the molded article 1 by the grooves 1a and holes 1b. The grooves 1a and holes 1b may have any shape according to the function. For example, the grooves 1a and holes 1b may be circular, elliptical, a shape combining a semi-circle and a rectangle, etc.

[0014] Figure 2 is a cross-sectional view taken along line II-II of Figure 1. As shown in Figure 2, the end face 1c of the molded product 1 formed by the groove 1a and the hole 1b may be inclined with respect to the thickness direction of the molded product 1. The groove 1a and the hole 1b may be tapered in the thickness direction of the molded product 1.

[0015] As shown in Figure 2, the molded product 1 has a fiber-reinforced resin substrate 5 and a resin layer 25. The resin layer 25 is laminated on the fiber-reinforced resin substrate 5. In the example shown in Figure 2, one resin layer 25 is laminated over the entire fiber-reinforced resin substrate 5. The resin layer 25 may be laminated only on a part of the fiber-reinforced resin substrate 5. In the example shown in Figure 2, one resin layer 25 is laminated on the first surface 5a of the fiber-reinforced resin substrate 5. The molded product 1 may have a plurality of resin layers 25. The molded product 1 may have two or more resin layers 25, and the resin layers 25 may be laminated on the first surface 5a and the second surface 5b of the fiber-reinforced resin substrate 5. The thickness of the molded product 1 is, for example, 0.1 mm or more and 50 mm or less.

[0016] In the examples shown in Figures 1 and 2, the molded product 1 is flat. Not limited to the illustrated example, the molded product 1 may be curved or bent.

[0017] <fiber-reinforced resin substrate> The fiber-reinforced resin substrate 5 is a lightweight and tough substrate. The fiber-reinforced resin substrate 5 is in the form of a thin plate. Figure 3 is an enlarged plan view of a part of the fiber-reinforced resin substrate 5. As shown in Figure 3, the fiber-reinforced resin substrate 5 includes fibers 5c and a matrix resin 5d. The matrix resin 5d is impregnated with the fibers 5c and cured. The fiber-reinforced resin substrate 5 is manufactured by impregnating fibers with a matrix resin such as a thermoplastic resin or a thermosetting resin to form a resin-impregnated fiber sheet, and then curing the resin-impregnated fiber sheet. The thickness of the fiber-reinforced resin substrate 5 is, for example, 0.1 mm or more and 50 mm or less. The content of the matrix resin 5d in the fiber-reinforced resin substrate 5 may be 30% by mass or more, or may be 40% by mass or less.

[0018] The fiber 5c may be various fiber forms such as, for example, long fibers aligned in one direction (UD), two - dimensional woven fabrics, multi - axial woven fabrics, non - woven fabrics, mats, knits, braids, etc. In the example shown in FIG. 3, the fiber 5c is long fibers (UD) arranged in the first direction D1 and aligned so as to extend in the second direction D2 orthogonal to the first direction D1. The long fibers mean, for example, continuous single fibers or fiber bundles of 10 mm or more. The diameter of the fiber 5c may be 1 μm or more, or 5 μm or more, or 10 μm or less. The fiber 5c may be carbon fiber or glass fiber. The carbon fiber is, for example, polyacrylonitrile - based carbon fiber, pitch - based carbon fiber, etc., or a mixture thereof. A resin - impregnated fiber sheet in which the carbon fiber is impregnated with a matrix resin or a fiber - reinforced resin substrate 5 obtained by curing the resin - impregnated fiber sheet is also referred to as a prepreg. The fiber - reinforced resin substrate 5 may be manufactured by laminating and curing a plurality of resin - impregnated fiber sheets.

[0019] The matrix resin 5d may be, for example, a thermosetting resin, a thermoplastic resin, or a thermoplastic elastomer. The thermosetting resin is, for example, an epoxy resin, an unsaturated polyester resin, a phenol resin, a silicone resin, a urethane resin, a urethane acrylate resin, a polyimide resin. The thermoplastic resin may be, for example, polysulfone, polyethersulfone, polyetherimide, polyimide.

[0020] <Resin layer> The resin layer 25 protects the fiber - reinforced resin substrate 5. The resin layer 25 is laminated on the fiber - reinforced resin substrate 5. The resin layer 25 is in a thin - plate shape. The thickness of the resin layer 25 may be 0.5 μm or more, or 1 μm or more, or 10 μm or more. The thickness of the resin layer 25 may be 300 μm or less, or 250 μm or less.

[0021] The resin layer 25 contains a resin cured product as the main component. Containing a resin cured product as the main component means that in the resin layer 25, the content of the resin cured product is 50% by mass or more, preferably 60% by mass or more. The resin cured product is formed by curing a resin composition, and the resin composition is sufficiently crosslinked. As a result, the average molecular weight of the resin cured product is sufficiently large, for example, 20,000 or more.

[0022] The resin cured product, which is the main component of the resin layer 25, may be a cured product of a thermosetting resin, a cured product of an ultraviolet curable resin, or a cured product of an ionizing radiation curable resin. The thermosetting resin is, for example, an acrylic resin, an epoxy resin, or a urethane resin. The ultraviolet curable resin is, for example, a radical polymerization type acrylic resin or a cationic polymerization type epoxy resin. The ionizing radiation curable resin is, for example, a (meth)acrylic modified unsaturated polyester resin, a (meth)acrylic modified epoxy resin, or a (meth)acrylic modified polyurethane resin.

[0023] When the resin composition constituting the resin layer 25 is a thermosetting resin, the resin layer 25 may contain a curing agent. The curing agent may be a photo radical polymerization initiator.

[0024] The resin layer 25 contains nanoparticles 25a. The nanoparticles 25a are encapsulated in the resin layer 25. The average primary particle diameter of the nanoparticles 25a may be 1 nm or more, 10 nm or more, 50 nm or less, or 30 nm or less. The shape of the nanoparticles 25a may be powdery such as spherical, ellipsoidal, or cubic (such as a rectangular parallelepiped or a cuboid); polygonal plate-like such as cylindrical, disc-shaped, elliptical disc-shaped, or scaly; or needle-like. When the nanoparticles 25a are not spherical, the average primary particle diameter of the nanoparticles 25a is the particle diameter of the circumscribed sphere of the nanoparticles 25a.

[0025] In the present disclosure, the average primary particle diameter of the nanoparticles 25a is calculated by statistical processing from an image obtained by a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM). Specifically, an image of a transmission electron microscope (TEM) or a scanning transmission electron microscope (STEM) is obtained from the front direction of the molded article 1 or the laminate 10 described later. The magnification of the image is 25,000 times or more and 35,000 times or less. The obtained image is subjected to binarization processing. For example, the density of the image is divided into gradations 0 to 255, and a threshold value of gradation is set for binarization processing so that the nanoparticles 25a can be distinguished from other members. In the binarized image, N nanoparticles 25a are randomly selected and the primary particle diameter is measured. N is, for example, 1000. A histogram with a 3 nm division is created from the measured particle diameters. Let the primary particle diameter of the i-th nanoparticle 25a in the histogram be d i , and the frequency be n i . Then, the average primary particle diameter D np of the nanoparticles 25a is calculated as follows.

Equation

[0026] The processing of the obtained image and the measurement of the particle diameter in the binarized image are carried out using the image processing software "ImageJ".

[0027] The content of the nanoparticles 25a in the resin layer 25 may be 5% by mass or more, or 10% by mass or more, or 15% by mass or more. The content of the nanoparticles 25a in the resin layer 25 may be 50% by mass or less, or 40% by mass or less, or 30% by mass or less.

[0028] The material of the nanoparticles 25a may be an organic material or an inorganic material. The material of the nanoparticles 25a may be a metal or a metal compound. The metal may be gold, silver, copper, platinum, palladium, nickel, cobalt, iron, manganese, silicon, titanium, zirconium, tungsten, molybdenum, chromium, zinc, aluminum, or a composite metal composed of two or more of these. The metal compound may be a metal oxide such as iron oxide, silicon oxide, zirconium oxide, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, cobalt oxide, nickel oxide, cerium oxide, cupric oxide, zinc oxide, tin oxide, antimony oxide, titanium dioxide, aluminum oxide, and mixtures thereof; metal nitrides such as aluminum nitride, gallium nitride, titanium nitride, silicon nitride, titanium nitride and mixtures of its children; metal sulfides such as cadmium sulfide, zinc sulfide, copper sulfide, molybdenum sulfide and mixtures thereof; metal carbides; metal borides; metal carbonates; zeolites; clays; or composites thereof. In particular, the material of the nanoparticles 25a is preferably a metal oxide, more preferably silicon oxide, zirconium oxide, or aluminum oxide.

[0029] <Others> The molded article 1 may further have other functional layers that exhibit various functions. The molded article 1 may have, for example, a surface protection function, a bonding function, a decoration function, an ultraviolet absorption function, an infrared absorption function, a gas barrier function, a humidity barrier function, an electromagnetic wave shielding function, an insulation function, a heat dissipation function, a conductive function, a scratch repair function, a scratch prevention function, a chemical resistance function, an atomic oxygen resistance function, and a galvanic corrosion prevention function. The functional layer is formed of a shape and a material suitable for the function to be exhibited.

[0030] The groove 1a and the hole 1b are formed, for example, by micro-blasting or an ultrashort pulse laser described later. When forming the groove 1a and the hole 1b, a part of the matrix resin 5d of the fiber-reinforced resin substrate 5 is missing at the end face 1c. The portion where the matrix resin 5d is missing is caused, for example, by polishing the matrix resin 5d with an abrasive or by removing the matrix resin 5d with a laser. On the surface of the molded product 1 where the abrasive is sprayed or the surface where the laser is irradiated, a portion where the matrix resin 5d is missing is more likely to occur than on the opposite surface.

[0031] In the end face 1c of the molded product 1 of the present embodiment, a portion where the matrix resin 5d is missing is less likely to occur. Specifically, the area of the portion where the matrix resin 5d is missing is 3000 μm 2 or less, preferably 2000 μm 2 or less, and more preferably 1500 μm 2 or less per length of 275 μm along the extending direction of the end face 1c.

[0032] The area of the portion where the matrix resin 5d is missing is measured by the following method. The end face 1c of the molded product 1 is observed with a shape analysis laser microscope VK (manufactured by Keyence Corporation, model number: X1000) at a magnification of 1000 times, which is a combination of an objective lens magnification of 50 times and an eyepiece lens magnification of 20 times. The observation field has a horizontal length of 275 μm and a vertical length of 207 μm. Align the direction in which the end face 1c extends with the horizontal direction of the field of view. The end face 1c is observed for 275 μm. An image of the vicinity of the end face 1c being observed in this state is acquired. An example of an image of the vicinity of the end face 1c of the molded product 1 of the present embodiment is shown in FIG. 5. In the example shown in FIG. 5, the fibers 5c are arranged in the first direction D1 and extend in the second direction D2 orthogonal to the first direction D1. The dark-colored portion in contact with the end face 1c in FIG. 5 corresponds to the portion where the matrix resin 5d is missing. The acquired image is subjected to binarization processing. For example, the density of the image is divided into gradations from 0 to 255, and while observing the image, a threshold value of the gradation is set for binarization processing so that the portion where the matrix resin 5d is missing can be distinguished from other portions. From the binarized image, the portion where the matrix resin 5d is missing and its area are measured.

[0033] The processing of the acquired image and the measurement of the area of the portion where the matrix resin 5d is missing in the binarized image are carried out using the image processing software "ImageJ".

[0034] Even when a groove 1a or a hole 1b is newly provided in the molded product 1 of the present embodiment, the portion where the matrix resin 5d is missing is unlikely to occur. The matrix resin 5d is likely to be missing when a groove 1a or a hole 1b is formed in the molded product along the arrangement direction (the first direction D1) of the fibers 5c. When a groove 1a or a hole 1b is formed in the molded product 1 of the present embodiment along the arrangement direction of the fibers 5c, in the end face 1c of the molded product 1 formed by the groove 1a or the hole 1b, the area of the portion where the matrix resin 5d is missing is 3000 μm per 275 μm of the length along the extending direction of the end face 1c 2 or less, preferably 2000 μm 2 or less, more preferably 1500 μm 2 or less.

[0035] [Laminated body] The laminated body 10 transfers the resin layer 25 to the fiber-reinforced resin substrate 5. FIG. 4 shows a cross-sectional view of an example of the laminated body 10. As shown in FIG. 4, the laminated body 10 has a base material 11 and a resin layer 25. The resin layer 25 is stacked on the base material 11. When the molded article 1 has a functional layer, the laminated body 10 may further have the functional layer.

[0036] [Base material]< The base material 11 supports the resin layer 25. The base material 11 is provided so as to overlap the surface of the resin layer 25. The base material 11 is provided so as to be peelable from the resin layer 25. In order to easily peel the base material 11 from the resin layer 25, a peeling layer (not shown) may be provided between the base material 11 and the resin layer 25. The peeling layer is made of, for example, a silicone resin. The base material 11 does not have to be peeled from the resin layer 25. When the base material 11 is not peeled from the resin layer 25, the molded article 1 further has the base material 11.

[0037] When the base material 11 is peeled from the resin layer 25, the base material 11 has appropriate flexibility and rigidity for appropriately supporting the resin layer 25 and easily peeling from the resin layer 25. The thickness of the base material 11 is, for example, 5 μm or more and 200 μm or less.

[0038] The material of the base material 11 is, for example, polyester such as polyethylene terephthalate and polybutylene terephthalate, polyolefin, polystyrene, vinyl resin, (meth)acrylic resin, amide resin, imide resin, and polycarbonate. In the present disclosure, “(meth)acrylic” includes both “acrylic” and “methacrylic”, and “(meth)acrylate” includes both “acrylate” and “methacrylate”. Considering the heat shrinkage during the production of the laminated body 10 and the difficulty of shrinkage due to irradiation with ionizing radiation, the material of the base material 11 is preferably polyethylene terephthalate or polybutylene terephthalate. Considering the heat shrinkage during the production of the laminated body 10 and the difficulty of shrinkage due to irradiation with ionizing radiation, the material of the base material 11 is preferably a stretched film, particularly a biaxially stretched film.

[0039] The thickness of the molded article 1, the thickness of the laminate 10, and the thicknesses of the respective members included in the molded article 1 and the laminate 10, particularly the thickness of the resin layer 25, can be specified by observing a cross-section of the molded article 1 or the laminate 10 with a scanning electron microscope (SEM). The cross-section is observed by cutting the molded article 1 or the laminate 10 with a microtome. The thickness of the molded article 1, the thickness of the laminate 10, and the thicknesses of the respective members included in the molded article 1 and the laminate 10 are specified as the average of the thicknesses at five locations of the respective members of interest in an image of the cross-section observed with a scanning electron microscope. The five locations for measuring the thickness are positions arranged at 25-μm intervals in a direction orthogonal to the thickness direction in the image of the cross-section.

[0040] [Manufacturing Method of the First Example] A first example of a method for manufacturing the molded article 1 using the laminate 10 will be described with reference to FIGS. 6 to 9. FIG. 6 shows an example of a laminating apparatus 50 that superimposes the laminate 10 on a resin-impregnated fiber sheet that becomes the fiber-reinforced resin substrate 5. The laminating apparatus 50 includes a first belt 51, a second belt 52, a heater 53, a cooler 54, and a film roller 58. The first belt 51 and the second belt 52 face each other. The distance between the first belt 51 and the second belt 52 is substantially the same as the thickness of the molded article 1 to be manufactured.

[0041] The method for manufacturing the molded article 1 includes a step of preparing the laminate 10 and a step of superimposing the laminate 10 on a resin-impregnated fiber sheet. The method for manufacturing the molded article 1 may further include a step of peeling the base material 11 and a step of forming a groove 1a or a hole 1b in the molded article 1.

[0042] [Preparation Step] Disperse and arrange the nanoparticles 25a in the resin composition that becomes the resin layer 25. Irradiate the resin composition with heat, ultraviolet rays, ionizing radiation, etc. to cure the resin composition and obtain a resin layer 25 containing a resin cured product as a main component. If necessary, a functional layer may be superimposed on the resin layer 25. Superimpose the base material 11 on the resin layer 25 to produce the laminate 10. The laminate 10 is prepared.

[0043] A resin-impregnated fiber sheet including fiber 5c and a matrix resin 5d impregnated in the fiber 5c is disposed in a laminating apparatus 50 along a first belt 51. In the resin-impregnated fiber sheet, the content of the matrix resin 5d is adjusted to be 30% by mass or more and 40% by mass or less. As shown in FIG. 6, a plurality of elements constituting the resin-impregnated fiber sheet may be separately disposed. Alternatively, a pre-formed fiber-reinforced resin substrate 5 may be used. The fiber-reinforced resin substrate 5 may be a laminated fiber-reinforced resin substrate formed by overlapping a fiber-reinforced resin substrate having fibers that are long fibers aligned in one direction with a fiber-reinforced resin substrate having fibers that are long fibers aligned in a direction perpendicular to the one direction using an automatic laminating apparatus or the like. The resin-impregnated fiber sheet is conveyed by the first belt 51.

[0044] The laminate 10 is stretched between a plurality of film rollers 58. When the laminate 10 overlaps the resin-impregnated fiber sheet, the resin layer 25 is disposed closer to the resin-impregnated fiber sheet than the base material 11. The laminate 10 is conveyed by the second belt 52.

[0045] <Laminating step> By sandwiching between the first belt 51 and the second belt 52, the laminate 10 is overlapped on the resin-impregnated fiber sheet such that the resin layer 25 is closer to the resin-impregnated fiber sheet than the base material 11. By being sandwiched between the first belt 51 and the second belt 52, the laminate 10 and the resin-impregnated fiber sheet are pressurized. By pressurizing the resin-impregnated fiber sheet, a plurality of elements constituting the resin-impregnated fiber sheet are integrated. The pressure applied to the laminate 10 and the resin-impregnated fiber sheet is, for example, 1 MPa or more and 10 MPa or less. The laminate 10 and the resin-impregnated fiber sheet are heated by the heater 53 while being pressurized. By heating and pressurizing the laminate 10 and the fiber-reinforced resin substrate 5, the resin-impregnated fiber sheet becomes the fiber-reinforced resin substrate 5, and the laminate 10 and the fiber-reinforced resin substrate 5 are integrated. More specifically, the matrix resin 5d of the resin-impregnated fiber sheet is dissolved by heat and pressure, so that the laminate 10 and the fiber-reinforced resin substrate 5 are integrated. The temperature for heating the laminate 10 and the resin-impregnated fiber sheet is, for example, 100°C or more and 230°C or less. The time for heating the laminate 10 and the resin-impregnated fiber sheet is, for example, 10 seconds or more and 180 seconds or less. After being heated, the laminate 10 and the fiber-reinforced resin substrate 5 are preferably cooled by the cooler 54. The temperature for cooling the laminate 10 and the fiber-reinforced resin substrate 5 is, for example, normal temperature or more and 60°C or less. The time for cooling the laminate 10 and the fiber-reinforced resin substrate 5 is, for example, 5 seconds or more and 150 seconds or less. By cooling the laminate 10 and the fiber-reinforced resin substrate 5, it is suppressed that the heated laminate 10 and the fiber-reinforced resin substrate 5 expand and the strength decreases.

[0046] <Peeling process> As shown in FIG. 8, the base material 11 may be peeled from the laminate 10. The peeled base material 11 is wound around the film roller 58. Through the above steps, the molded product 1 is manufactured.

[0047] <Forming process> A groove 1a or a hole 1b is formed in the molded article 1. The groove 1a or the hole 1b may be formed by various methods. The groove 1a or the hole 1b is formed, for example, by micro-blasting or an ultrashort pulse laser. According to micro-blasting, an abrasive having a particle size of 10 μm or more and 70 μm or less is sprayed at high speed onto the position where the groove 1a or the hole 1b of the molded article 1 is to be formed, thereby shaving the molded article 1 to form the groove 1a or the hole 1b. By adjusting the strength and time of spraying the abrasive, the groove 1a or the hole 1b can be appropriately formed. The ultrashort pulse laser is a laser having a pulse width of about 100 femtoseconds to several picoseconds. As shown in FIG. 9, by irradiating the ultrashort pulse laser L onto the position where the groove 1a or the hole 1b of the molded article 1 is to be formed, a part of the molded article 1 is removed to form the groove 1a or the hole 1b. By adjusting the intensity etc. of the ultrashort pulse laser, the groove 1a or the hole 1b can be appropriately formed.

[0048] The ultrashort pulse laser for forming the groove 1a or the hole 1b in the molded article 1 is irradiated using a laser device (PiCooL manufactured by LIPS WORKS Co., Ltd.). The conditions for laser irradiation are as follows. Processing head: Galvano scanner Processing lens: f163 mm Oscillator: TruMicro5000 Laser wavelength: 515 nm Pulse width: 8 ps Maximum average output: 30 W Maximum pulse energy: 150 μJ Maximum oscillation frequency: 200 kHz

[0049] [Manufacturing method of the second example] A second example of a method for manufacturing the molded article 1 using the laminate 10 will be described with reference to FIG. 10. FIG. 10 shows another example of a laminating apparatus 50 that stacks the laminate 10 on a resin-impregnated fiber sheet that becomes the fiber-reinforced resin substrate 5. The laminating apparatus 50 includes a first belt 51, a second belt 52, a heater 53, a cooler 54, a second heater 55, a heat roll 56, a peeling roll 57, and a film roller 58. The first belt 51 and the second belt 52 face each other. The distance between the first belt 51 and the second belt 52 is substantially the same as the thickness of the molded article 1 to be manufactured.

[0050] The second example of the method for manufacturing the molded article 1 also includes a step of preparing the laminate 10 and a step of stacking the laminate 10 on the resin-impregnated fiber sheet. The second example of the method for manufacturing the molded article 1 may further include a step of peeling the base material 11 and a step of forming the groove 1a or the hole 1b in the molded article 1. In the second example of the method for manufacturing the molded article 1, the step of preparing the laminate 10 and the step of forming the groove 1a or the hole 1b in the molded article 1 are the same as those in the first example of the method for manufacturing the molded article 1 described above.

[0051] A resin-impregnated fiber sheet including the fiber 5c and the matrix resin 5d impregnated in the fiber 5c is disposed in the laminating apparatus 50 along the first belt 51. As shown in FIG. 10, a plurality of elements constituting the resin-impregnated fiber sheet may be separately disposed. Alternatively, similar to the first example of the method for manufacturing the molded article 1, a pre-formed resin-impregnated fiber sheet may be used. The resin-impregnated fiber sheet is conveyed by the first belt 51.

[0052] The laminate 10 is stretched between a plurality of film rollers 58 while passing through the heat roll 56 and the peeling roll 57. The laminate 10 overlaps the resin-impregnated fiber sheet at a position away from the first belt 51 and the second belt 52. When the laminate 10 overlaps the resin-impregnated fiber sheet, the resin layer 25 is disposed closer to the resin-impregnated fiber sheet than the base material 11. The laminate 10 is conveyed by the rotation of the film roller 58.

[0053] By being sandwiched between the first belt 51 and the second belt 52, the resin-impregnated fiber sheet is pressurized. When the resin-impregnated fiber sheet is pressurized, a plurality of elements constituting the resin-impregnated fiber sheet are integrated. The pressure applied to the resin-impregnated fiber sheet is, for example, 1 MPa or more and 10 MPa or less. The resin-impregnated fiber sheet is heated by the heater 53 while being pressurized. The temperature for heating the resin-impregnated fiber sheet is, for example, 100 °C or more and 230 °C or less. The time for heating the resin-impregnated fiber sheet is, for example, 10 seconds or more and 180 seconds or less. By heating and pressurizing the resin-impregnated fiber sheet, the resin-impregnated fiber sheet becomes the fiber-reinforced resin substrate 5. After being heated, the fiber-reinforced resin substrate 5 is preferably cooled by the cooler 54. The temperature for cooling the fiber-reinforced resin substrate 5 is, for example, room temperature or more and 60 °C or less. The time for cooling the fiber-reinforced resin substrate 5 is, for example, 5 seconds or more and 150 seconds or less. By cooling the fiber-reinforced resin substrate 5, it is possible to suppress the expansion and strength reduction of the heated fiber-reinforced resin substrate 5.

[0054] <Laminating process> The fiber-reinforced resin substrate 5 is reheated by the second heater 55. While being heated by the heat roll 56, the laminate 10 is overlapped with the fiber-reinforced resin substrate 5 so that the resin layer 25 comes closer to the fiber-reinforced resin substrate 5 from the base material 11. Between the heat roll 56 and the peeling roll 57, the laminate 10 is pressurized toward the fiber-reinforced resin substrate 5. By heating and pressurizing the laminate 10 and the fiber-reinforced resin substrate 5, the laminate 10 and the fiber-reinforced resin substrate 5 are integrated. More specifically, the matrix resin 5d of the fiber-reinforced resin substrate 5 is melted by heat and pressure, so that the laminate 10 and the fiber-reinforced resin substrate 5 are integrated.

[0055] <Peeling process> When the laminate 10 is separated from the peeling roll 57, the base material 11 may be peeled from the laminate 10. The peeled base material 11 is wound around the film roller 58. Through the above steps, the molded product 1 is manufactured.

[0056] The manufacturing method of the molded product 1 in which the resin layer 25 is stacked on the fiber-reinforced resin substrate 5 using the above-described laminating apparatus 50 is merely an example. The molded product 1 may be manufactured, for example, by bonding the resin layer 25 to the fiber-reinforced resin substrate 5 by dry lamination.

[0057] In a conventional molded product, the resin layer is not properly stacked on the fiber-reinforced resin substrate. When a groove or a hole is formed in the conventional molded product, a large portion where the matrix resin of the fiber-reinforced resin substrate is missing occurs at the end face of the molded product on the surface of the groove or the hole. FIG. 11 is a view corresponding to FIG. 5, and is an image of the vicinity of the end face 101c of the molded product 101 on the surface of the hole 101b formed in the conventional molded product 101. In the example shown in FIG. 11, the fibers are arranged in the first direction D1 and extend in the second direction D2 orthogonal to the first direction D1. As is clear from the comparison between FIG. 11 and FIG. 5, a large portion where the matrix resin is missing exists at the end face 101c of the conventional molded product 101. If the portion where the matrix resin is missing is large, problems may occur in which the characteristics of the molded product are significantly deteriorated. For example, the rigidity of the molded product decreases, vibration damping becomes difficult, and corrosion easily occurs. In the portion where the matrix resin is missing, the fibers are largely exposed from the fiber-reinforced resin substrate. Problems may occur due to the largely exposed fibers. For example, if the fibers have conductivity, an external circuit may short-circuit by contacting the exposed fibers. Thus, if the portion where the matrix resin is missing is large, the molded product may cause problems. The portion where the matrix resin is missing may expand when the molded product is used over a long period of time. The larger the portion where the matrix resin is missing, the more easily it expands over time. If the portion where the matrix resin is missing is large, the molded product is more likely to cause problems over time.

[0058] The molded product 1 of this embodiment has a resin layer 25 laminated on a fiber-reinforced resin substrate 5. The thickness of the resin layer 25 is 0.5 μm or more and 300 μm or less. The resin layer 25 contains a cured resin as a main component. The resin layer 25 contains nanoparticles. Since such a resin layer 25 is laminated on the fiber-reinforced resin substrate 5, even when grooves 1a and holes 1b are formed in the molded product 1, it is less likely that a portion where the matrix resin 5d is missing will occur. Specifically, at the end face 1c of the molded product 1, the area of the portion where the matrix resin 5d is missing is 3000 μm per 275 μm of the length along the direction in which the end face 1c extends. 2 It is as follows. Alternatively, even when a groove 1a or a hole 1b is formed in the molded product 1 along the arrangement direction of the fibers 5c so that a portion where the matrix resin 5d is missing is likely to occur, at the end face 1c of the molded product 1 formed by the groove 1a or the hole 1b, the area of the portion where the matrix resin 5d is missing is 3000 μm per 275 μm of the length along the arrangement direction of the fibers 5c. 2 It is as follows. Since the portion where the matrix resin 5d is missing is sufficiently small, problems caused by the portion where the matrix resin is missing can be suppressed.

[0059] Since the thickness of the resin layer 25 is sufficiently thick at 0.5 μm or more, the resin layer 25 can appropriately protect the fiber-reinforced resin substrate 5 when the grooves 1a and holes 1b are formed. The resin layer 25 makes it less likely that a portion where the matrix resin 5d is missing will occur. Since the thickness of the resin layer 25 is not too thick at 300 μm or less, an increase in the thickness of the molded product 1 is suppressed.

[0060] Since the resin layer 25 contains a cured resin as a main component, the resin layer 25 can appropriately protect the fiber-reinforced resin substrate 5 when the grooves 1a and holes 1b are formed. The cured resin makes it less likely that a portion where the matrix resin 5d is missing will occur.

[0061] Since the resin layer 25 contains the nanoparticles 25a, when grooves 1a and holes 1b are provided in the molded product 1, the resin layer 25 is more likely to be appropriately removed. The end face 1c of the molded product 1 is more likely to be appropriately formed. This is presumably because when grooves 1a and holes 1b are provided in the molded product 1, the nanoparticles 25a serve as the starting points for the removal of the resin layer 25, and the resin layer 25 is removed in units of the nanoparticles 25a. However, the reason why the resin layer 25 is more likely to be appropriately removed is not limited to this idea.

[0062] The content of the matrix resin 5d in the fiber-reinforced resin substrate 5 is 30% by mass or more and 40% by mass or less. Since the matrix resin 5d is sufficiently small, the molded product 1 having the fiber-reinforced resin substrate 5 can sufficiently exhibit the characteristics due to the fibers 5c. Since the matrix resin 5d is sufficiently large, grooves 1a and holes 1b can be appropriately formed in the molded product 1 having the fiber-reinforced resin substrate 5.

[0063] The laminate 10 of the present embodiment includes a resin layer 25. The thickness of the resin layer 25 is 0.5 μm or more and 300 μm or less. According to the laminate 10, the above-described molded product 1 can be easily manufactured.

[0064] The molded product 1 of the present embodiment includes a fiber-reinforced resin substrate 5 and a resin layer 25 laminated on the fiber-reinforced resin substrate 5. The fiber-reinforced resin substrate 5 includes a plurality of fibers 5c and a matrix resin 5d impregnated in the fibers 5c. The thickness of the resin layer 25 is 0.5 μm or more and 300 μm or less. The resin layer 25 contains a resin cured product as a main component. The resin layer 25 contains nanoparticles 25a. According to the molded product 1 of the present embodiment, even when grooves 1a and holes 1b are formed in the molded product 1, a portion where the matrix resin 5d is missing is less likely to occur. Defects due to a portion where the matrix resin is missing can be suppressed.

[0065] Aspects of the present disclosure are not limited to the above-described embodiments, but also include various modifications that can be conceived by those skilled in the art, and the effects of the present disclosure are not limited to the content related to the above-described embodiments. Various additions, changes, and partial deletions are possible without departing from the conceptual ideas and gists of each disclosure derived from the content defined in the claims and their equivalents.

Example

[0066] The present disclosure will be described in more detail by way of examples. The present disclosure is not limited to the following examples.

[0067] As examples and comparative examples, a plurality of molded articles having a fiber-reinforced resin substrate and a resin layer were produced using a laminate having a base material and a resin layer. In each example and each comparative example, the base material is polyethylene terephthalate with a thickness of 50 μm. The fiber-reinforced resin substrate is a prepreg with a thickness of 200 μm obtained by curing a resin-impregnated fiber sheet impregnated with a urethane acrylate resin and a curing agent in carbon fibers aligned in one direction. In each example and each comparative example, the composition of the resin layer and the content of the matrix resin of the fiber-reinforced resin substrate are different.

[0068] (Example 1) In the laminate according to Example 1, the resin layer contains a polyfunctional acrylate as a resin composition and nanoparticles having an average primary particle diameter of 20 nm. The nanoparticles are made of silica. The content of the nanoparticles in the resin layer is 25% by mass. The thickness of the resin layer is 10 μm. After coating the resin layer, it was irradiated with an electron beam and cured to obtain a cured resin. The resin layer side of the laminate according to Example 1 was overlaid on the fiber-reinforced resin substrate and molded using the laminating apparatus shown in FIG. 6 under the conditions of a speed of 0.3 m / min, a temperature of 130 ° C., a heating time of 8 minutes, and a pressure of 3 MPa to produce a molded article according to Example 1. The content of the matrix resin of the fiber-reinforced resin substrate is 35% by mass.

[0069] (Example 2) A molded article was produced using the laminate in the same manner as in Example 1, except for the thickness of the resin layer. The thickness of the resin layer according to Example 2 is 1 μm.

[0070] (Example 3) A molded product was produced using the laminate in the same manner as in Example 1, except for the thickness of the resin layer. The thickness of the resin layer according to Example 3 is 105 μm.

[0071] (Example 4) A molded product was produced using the laminate in the same manner as in Example 1, except for the thickness of the resin layer. The thickness of the resin layer according to Example 4 is 250 μm.

[0072] (Example 5) A molded product was produced using the laminate in the same manner as in Example 1, except for the thickness of the resin layer. The thickness of the resin layer according to Example 5 is 300 μm.

[0073] (Example 6) In the laminate according to Example 6, the resin layer contains a polyfunctional acrylate as a resin composition, a photo radical polymerization initiator as a curing agent, and nanoparticles having an average primary particle diameter of 15 nm. The nanoparticles are made of alumina. The content of the nanoparticles in the resin layer is 20% by mass. The thickness of the resin layer is 10 μm. After the resin layer was applied, it was irradiated with ultraviolet rays to be cured to obtain a cured resin product. The laminate according to Example 6 was molded in the same manner as in Example 1 to produce a molded product according to Example 6. The content of the matrix resin of the fiber-reinforced resin substrate is 30% by mass.

[0074] (Example 7) A molded product was produced using the laminate in the same manner as in Example 6, except for the content of the matrix resin of the fiber-reinforced resin substrate. The content of the matrix resin of the fiber-reinforced resin substrate according to Example 7 is 26% by mass.

[0075] (Example 8) A molded product was produced using the laminate in the same manner as in Example 6, except for the content of the matrix resin of the fiber-reinforced resin substrate. The content of the matrix resin of the fiber-reinforced resin substrate according to Example 8 is 40% by mass.

[0076] (Comparative Example 1) A molded article was produced using a laminate in the same manner as in Example 1, except that it did not contain nanoparticles.

[0077] (Comparative Example 2) A molded article was produced using a laminate in the same manner as in Example 1, except that the resin layer contained an ester-based thermoplastic elastomer as a resin composition and the resin layer was not cured.

[0078] (Comparative Example 3) A molded article was produced using a laminate in the same manner as in Example 1, except for the thickness of the resin layer. The thickness of the resin layer according to Comparative Example 1 was 0.1 μm.

[0079] (Comparative Example 4) A molded article was made of only a fiber-reinforced resin substrate without a resin layer.

[0080] (Measurement) Holes were formed in the molded articles according to each Example and each Comparative Example along the fiber alignment direction. An end face was formed on the molded article by the holes. The area per 275 μm in length along the fiber alignment direction of the portion where the matrix resin of the fiber-reinforced resin substrate was missing on the end face was measured. After subjecting the molded articles according to each Example and each Comparative Example to the environmental storage test described below, the area per 275 μm in length along the fiber alignment direction of the portion where the matrix resin of the fiber-reinforced resin substrate was missing on the end face was measured again. The increase rate of the area of the portion where the matrix resin was missing before and after the environmental storage test was calculated.

[0081] The molded article was irradiated with an ultrashort pulse laser to form holes in the molded article. The ultrashort pulse laser was irradiated by a laser device (PiCooL manufactured by LIPS WORKS Co., Ltd.). The conditions for laser irradiation were as follows. Processing head: Galvanometer scanner Processing lens: f163 mm Oscillator: TruMicro5000 Laser wavelength: 515 nm Pulse width: 8 ps Maximum average output: 30 W Maximum pulse energy: 150 μJ Maximum oscillation frequency: 200 kHz

[0082] The area per 275 μm in the fiber alignment direction of the portion where the matrix resin of the fiber-reinforced resin substrate is missing on the end face was measured by the following method. The end face of the molded product was observed with a shape analysis laser microscope VK (manufactured by Keyence Corporation, model number: X1000) at a magnification of 1000 times with an objective lens magnification of 50 times and an eyepiece lens magnification of 20 times. The observation field has a horizontal length of 275 μm and a vertical length of 207 μm. Align the direction of extension of the end face in the horizontal length direction of the field of view. An image near the end face being observed in this state is acquired. The acquired image is subjected to binarization processing. The density of the image is divided into gradations 0 to 255, and while observing the image, a gradation threshold value is set for binarization processing so that the portion where the matrix resin is missing can be distinguished from other portions. From the binarized image, the portion where the matrix resin is missing and its area are measured.

[0083] The processing of the acquired image and the measurement of the area of the portion where the matrix resin is missing in the binarized image were carried out using the image processing software "ImageJ".

[0084] The environmental preservation test is carried out as follows. The molded product is stored in an environment of 80 °C for 1000 hours. Then, a cellophane adhesive tape conforming to JIS Z1522:2009 is attached to the end of the molded product where the portion where the matrix resin is missing was measured in the same manner as the adhesion test conforming to ISO 2409:2020, and then peeled off. However, when attaching the cellophane adhesive tape, cross-cutting of the cellophane adhesive tape was not performed.

[0085] The differences in the configurations and the measurement results of each example and each comparative example are shown in Table 1.

[0086]

Table 1

[0087] From the results shown in Table 1, the following can be understood. Comparing the example with Comparative Example 4, when a resin layer is laminated on the fiber-reinforced resin substrate, when a hole is formed in the molded product, the area of the portion where the matrix resin is missing on the end face of the molded product formed by the hole becomes smaller. Comparing the example with Comparative Example 1, since the resin layer contains nanoparticles, the area of the portion where the matrix resin is missing becomes smaller. Comparing the example with Comparative Example 2, since the resin layer contains a resin cured product as a main component, the area of the portion where the matrix resin is missing becomes smaller. Comparing the example with Comparative Example 3, since the thickness of the resin layer is 0.5 μm or more, the area of the portion where the matrix resin is missing becomes smaller. Specifically, the area of the portion where the matrix resin is missing is 3000 μm 2 becomes as follows. When the area of the portion where the matrix resin is missing is 3000 μm 2 or less, even after performing the environmental preservation test, that is, even when the molded product is used over a long period of time, the portion where the matrix resin is missing is less likely to spread. In the molded product, defects due to the portion where the matrix resin is missing are suppressed.

Explanation of Signs

[0088] 1 Molded product 1a Groove 1b Hole 1c End face 5 Fiber-reinforced resin substrate 5a First surface 5b Second surface 5c Fiber 5d Matrix resin 10 Laminate 11 Base material 25 Resin layer 25a Nanoparticle 50 Laminating device

Claims

1. A fiber-reinforced resin substrate, and a resin layer laminated on the fiber-reinforced resin substrate, wherein the fiber-reinforced resin substrate includes a plurality of fibers and a matrix resin impregnated into the fibers and cured, the thickness of the resin layer is 0.5 μm or more and 300 μm or less, the resin layer contains a cured resin as a main component, and the resin layer contains nanoparticles, a molded article.

2. A molded article comprising a fiber-reinforced resin substrate, and a resin layer laminated on the fiber-reinforced resin substrate, wherein the fiber-reinforced resin substrate includes a plurality of fibers and a matrix resin impregnated into the fibers and cured. On the end face of the molded article, the area of the portion where the matrix resin is missing is 3000 μm per 275 μm of the length along the direction in which the end face extends. ２ The following is a molded article.

3. A molded article comprising a fiber-reinforced resin substrate, and a resin layer laminated on the fiber-reinforced resin substrate, wherein the fiber-reinforced resin substrate includes a plurality of fibers and a matrix resin impregnated into the fibers and cured. When a groove or a hole is formed in the molded article along the arrangement direction of the fibers, the area of the portion where the matrix resin of the fiber-reinforced resin substrate is missing on the end face of the molded article formed by the groove or the hole is 3000 μm per 275 μm of the length along the arrangement direction of the fibers. ２ The molded article is as follows.

4. The molded article according to claim 2 or 3, wherein the thickness of the resin layer is 0.5 μm or more and 300 μm or less.

5. The molded article according to claim 2 or 3, wherein the resin layer contains a cured resin as a main component.

6. The molded article according to claim 2 or 3, wherein the resin layer contains nanoparticles.

7. The molded article according to any one of claims 1 to 3, wherein the content of the matrix resin in the fiber-reinforced resin substrate is 30% by mass or more and 40% by mass or less.

8. A laminate for transferring a resin layer onto a fiber-reinforced resin substrate, including a base material layer, and a resin layer laminated on the base material layer, wherein the thickness of the resin layer is 0.5 μm or more and 300 μm or less, a laminate.

9. The laminate according to claim 8, wherein the resin layer contains a cured resin as a main component.

10. The laminate according to claim 8, wherein the resin layer contains nanoparticles.

11. A preparation step of preparing a laminate including a base material and a resin layer laminated on the base material, and a lamination step of laminating the laminate so that the resin layer is closer to a resin-impregnated fiber sheet than the base material, wherein in the lamination step, the resin layer and the resin-impregnated fiber sheet are heated and pressurized, a method for manufacturing a molded article.

12. The method for manufacturing a molded article according to claim 11, further comprising a peeling step of peeling the base material.

13. The method for manufacturing a molded article according to claim 11, further comprising a forming step of forming a groove or a hole in the molded article.

Images