Functional films, fiber-reinforced plastic molded articles, intermediates, and methods for manufacturing fiber-reinforced plastic molded articles

Abstract

The present invention provides a functional film, a fiber-reinforced plastic molded product, an intermediate, and a method for manufacturing a fiber-reinforced plastic molded product, which can impart weather resistance to fiber-reinforced plastic molded products without the need for painting. [Solution] The functional film 10 for the fiber-reinforced plastic molded product 30 comprises a base material 11 and a transfer layer 15 laminated on the base material 11. The transfer layer 15 has a functional layer 12, and the functional layer 12 contains a weather-resistant agent.

Description

Technical Field

[0001] The present disclosure relates to a functional film, a fiber reinforced plastic molded article, an intermediate, and a method for manufacturing a fiber reinforced plastic molded article.

Background Art

[0002] Conventionally, fiber reinforced plastic molded articles such as FRP (Fiber Reinforced Plastics) and FRTP (fiber Reinforced thermoplastic) are known. The fiber reinforced plastic molded article has improved strength and rigidity compared to a resin sheet by reinforcing a matrix resin with fibers.

[0003] In particular, fiber reinforced plastic molded articles used outdoors may be exposed to severe weather conditions. However, some of the matrix resins used in fiber reinforced plastic molded articles have insufficient weather resistance when used outdoors.

[0004] In addition, painting of fiber reinforced plastic molded articles has also been performed (see, for example, Patent Document 1). However, when painting a fiber reinforced plastic molded article, since the number of painting steps is large, there is a risk that the manufacturing cost increases or the painting quality varies.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] This disclosure provides a functional film, a fiber-reinforced plastic molded product, an intermediate, and a method for manufacturing a fiber-reinforced plastic molded product, which can impart weather resistance to fiber-reinforced plastic molded products without painting. [Means for solving the problem]

[0007] Embodiments of this disclosure relate to the following [1] to

[17] .

[0008] [1] A functional film for fiber-reinforced plastic molded articles, comprising a base material and a transfer layer laminated on the base material, wherein the transfer layer has a functional layer, and the functional layer contains a weather-resistant agent.

[0009] [2] The functional film according to [1], wherein the transfer layer has an adhesion layer located on the opposite side of the functional layer from the substrate.

[0010] [3] The functional film according to [2], wherein the transfer layer has an adhesive layer located between the adhesion layer and the functional layer.

[0011] [4] The functional film according to any one of [1] to [3], wherein the transfer layer is a design layer.

[0012] [5] The functional film according to any one of [1] to [4], wherein the total thickness of the transfer layer is 10 μm or more and 150 μm or less.

[0013] [6] The functional film according to any one of [1] to [5], wherein the melting point of the substrate is 80°C or more and 300°C or less.

[0014] [7] The functional film according to any one of [1] to [6], wherein the elongation at break of the substrate and the functional layer at 130°C is 1% or more and 400% or less.

[0015] [8] The functional film according to any one of [1] to [7], wherein the elastic modulus of the substrate and the functional layer at 130°C is 0.01 GPa or more and 10 GPa or less.

[0016] [9] The functional film according to any one of [1] to [8], wherein the surface roughness Sa of the surface of the substrate located on the functional layer side is 0.2 μm or less.

[0017]

[10] The functional film according to any one of [1] to [8], wherein the surface roughness Sa of the surface of the substrate located on the functional layer side is 0.3 μm or more.

[0018]

[11] A fiber-reinforced plastic molded article comprising a prepreg and a transfer layer disposed on the prepreg, wherein the transfer layer has a functional layer, and the functional layer contains a weather-resistant agent.

[0019]

[12] The fiber-reinforced plastic molded article according to

[11] , wherein the transfer layer has an adhesion layer located on the prepreg side of the functional layer.

[0020]

[13] The fiber-reinforced plastic molded article according to

[12] , wherein the prepreg includes a matrix resin, the matrix resin is a thermoplastic resin, and the resin contained in the adhesion layer is an olefin resin.

[0021]

[14] The fiber-reinforced plastic molded article according to

[12] , wherein the prepreg includes a matrix resin, the matrix resin is a thermosetting resin, and the resin included in the adhesion layer is an acrylic resin, a urethane resin, or an epoxy resin.

[0022]

[15] An intermediate comprising a prepreg and a functional film according to any one of [1] to

[10] disposed on the prepreg.

[0023] A method for manufacturing a fiber reinforced plastic molded product, comprising: a step of preparing a functional film according to any one of

[16] [1] to

[10] ; a step of preparing a prepreg; a step of laminating the functional film and the prepreg; a step of integrally joining the functional film and the prepreg by heating and pressing the functional film and the prepreg; and a step of peeling and removing the base material from the functional layer.

[0024] A method for manufacturing a fiber reinforced plastic molded product, comprising: a step of preparing an intermediate according to

[17]

[15] ; a step of preparing a prepreg; a step of laminating the intermediate and the prepreg; a step of integrally joining the intermediate and the prepreg by heating and pressing the intermediate and the prepreg; and a step of peeling and removing the base material from the functional layer.

Advantages of the Invention

[0025] According to the present disclosure, weather resistance can be imparted to a fiber reinforced plastic molded product without applying painting.

Brief Description of the Drawings

[0026] [Figure 1] FIG. 1 is a schematic perspective view showing a functional film according to an embodiment. [Figure 2] FIG. 2 is a schematic perspective view showing a fiber reinforced plastic molded product according to an embodiment. [Figure 3] FIG. 3 is a schematic perspective view showing an intermediate according to an embodiment. [Figure 4] FIGS. 4(A)-(D) are diagrams showing a method for manufacturing a functional film according to an embodiment. [Figure 5] FIGS. 5(A)-(C) are diagrams showing a method for manufacturing a fiber reinforced plastic molded product according to an embodiment. [Figure 6] FIG. 6 is a schematic perspective view showing a hot press machine. [Figure 7] FIG. 7(A)-(E) are diagrams showing a method for manufacturing a fiber reinforced plastic molded product according to a modification. [Modes for carrying out the invention]

[0027] Hereinafter, one embodiment will be described with reference to Figures 1 to 7. Figures 1 to 7 are diagrams illustrating one embodiment. In the following figures, the same parts are denoted by the same reference numerals, and some detailed explanations may be omitted.

[0028] (Composition of functional film) Figure 1 illustrates the configuration of the functional film according to this embodiment.

[0029] The functional film 10 shown in Figure 1 is a film used to produce a fiber-reinforced plastic molded product 30, which will be described later. The functional film 10 comprises a base material 11 and a functional layer 12 laminated on the base material 11. The functional layer 12 contains a weather-resistant agent. The functional film 10 includes an adhesive layer 14 located on the opposite side of the functional layer 12 from the base material 11. The functional film 10 includes an adhesive layer 13 located between the adhesive layer 14 and the functional layer 12. The functional film 10 may also be called a transfer film.

[0030] The functional film 10 is constructed by laminating a base material 11, a functional layer 12, an adhesive layer 13, and an adhesion layer 14 in this order. In Figure 1, for convenience, the base material 11, functional layer 12, adhesive layer 13, and adhesion layer 14 are shown to have progressively smaller planar shapes, but the planar shapes of the base material 11, functional layer 12, adhesive layer 13, and adhesion layer 14 may be identical to each other.

[0031] The transfer layer 15 is composed of the layers of the functional film 10, excluding the base material 11. In Figure 1, the transfer layer 15 includes the functional layer 12, the adhesive layer 13, and the bonding layer 14. The transfer layer 15 is bonded to the prepreg 31, which will be described later, and integrates with the prepreg 31 to obtain a fiber-reinforced plastic molded product 30.

[0032] The total thickness of the transfer layer 15 is preferably 10 μm to 150 μm, more preferably 15 μm to 120 μm, and even more preferably 20 μm to 100 μm. By having a total thickness of 10 μm to 150 μm for the transfer layer 15, the weather resistance of the fiber-reinforced plastic molded product 30 can be further improved.

[0033] The composition of each layer of the functional film 10 will be explained further.

[0034] <Base material> The base material 11 is located on the outermost side of the functional film 10 (the side furthest from the prepreg 31). The base material 11 has a first surface 11a and a second surface 11b. The first surface 11a constitutes the outermost surface of the functional film 10. The second surface 11b is on the opposite side of the first surface 11a and is located on the functional layer 12 side. The base material 11 serves as a support for stably holding the other layers of the functional film 10. The base material 11 is removed after the functional film 10 has been brought into close contact with the prepreg 31. The base material 11 may also be called a release film.

[0035] The substrate 11 may have a substrate body and a release layer provided on the substrate body. Such a substrate 11 tends to have a low surface free energy. In addition, for example, the release properties between the functional layer 12 and the substrate 11 during transfer can be improved. On the other hand, the release layer may be a layer that has undergone surface treatment such as corona treatment or plasma treatment, or an easy-adhesion layer. In this case, the adhesion between the functional layer 12 and the substrate 11 is improved, and the functional layer 12 can be prevented from lifting away from the substrate 11 during the transfer process.

[0036] The base material is, for example, a film made of a resin material (hereinafter also referred to as "resin film"). Examples of resin materials include polyester, polyolefin, polystyrene, vinyl resin, (meth)acrylic resin, polyamide, polyimide, and polycarbonate. In this disclosure, "(meth)acrylic" includes both "acrylic" and "methacrylic".

[0037] The base material may be, for example, a paper base material such as glassine paper, condenser paper, or paraffin paper. Alternatively, metal foils such as aluminum foil or copper foil may be used as the base material.

[0038] Polyester film and polyolefin film are preferred as the resin film. Because the resin film is one of these films, a functional layer 12, for example, can be easily formed on the substrate 11.

[0039] Examples of polyesters include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and polyethylene terephthalate-isophthalate copolymers. Among these, PET and PBT are preferred, with PET being more preferred, from the viewpoint of being less susceptible to thermal shrinkage during the manufacture of the functional film 10 and shrinkage due to irradiation with ionizing radiation.

[0040] Examples of polyolefins include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, and ethylene-propylene-butene copolymer. Among these, polypropylene is preferred from the viewpoint of being less susceptible to thermal shrinkage during the manufacture of the functional film 10 and shrinkage due to irradiation with ionizing radiation.

[0041] The substrate body may have a single-layer structure or a multi-layer structure. The substrate body may be, for example, a single layer of resin film or paper substrate, a laminate of resin film, a laminate of paper substrate, or a laminate of resin film and paper substrate. A laminate of resin film can be manufactured, for example, by using a dry lamination method, a wet lamination method, or an extrusion method.

[0042] The thickness of the substrate body is preferably 5 μm to 200 μm, more preferably 10 μm to 100 μm. If the substrate body has a multilayer structure, it is preferable that the entire multilayer structure has a thickness within the above range.

[0043] The release layer may be formed on the surface of the substrate body by applying a release treatment using a release agent containing a silicone compound or a melamine compound. The release layer may also be a resin layer containing a silicone compound or a melamine compound. Alternatively, the release layer may be a layer that has undergone surface treatment such as corona treatment or plasma treatment, or an easy-adhesion layer.

[0044] The base material 11 preferably has heat resistance equal to or greater than the molding temperature of the prepreg 31. In other words, it is preferable that the melting point of the base material 11 is equal to or greater than the molding temperature of the prepreg 31. The melting point of the base material 11 is preferably 80°C to 300°C. As the heat-resistant base material 11, for example, the PET film described above may be used. The heat resistance of the base material 11 prevents the base material 11 from being unable to withstand the molding temperature of the prepreg 31, which would prevent the transfer layer 15 from being transferred to the prepreg 31.

[0045] The surface roughness Sa of the second surface 11b of the substrate 11, which is located on the functional layer 12 side, may be 0.2 μm or less, or 0.1 μm or less. There is no particular lower limit for the surface roughness Sa of the second surface 11b of the substrate, but it may be, for example, 0.003 μm or more. By setting the surface roughness Sa of the second surface 11b of the substrate within the above range, the outer surface of the fiber-reinforced plastic molded product 30 (the first surface 12a of the functional layer, described later) can be made mirror-like.

[0046] The surface roughness Sa of the second surface 11b of the substrate 11, which is located on the functional layer 12 side, may be 0.3 μm or more, or 0.5 μm or more. There is no particular upper limit to the surface roughness Sa of the second surface 11b of the substrate, but it may be, for example, 5 μm or less. By setting the surface roughness Sa of the second surface 11b of the substrate within the above range, the outer surface of the fiber-reinforced plastic molded product 30 (the first surface 12a of the functional layer, described later) can be made into a matte surface.

[0047] The surface roughness Sa of the second surface 11b of the substrate is calculated using a KEYENCE laser microscope in accordance with ISO 25178, with the measurement area set to 250 μm × 250 μm.

[0048] <Functional Layer> The functional layer 12 is located between the substrate 11 and the adhesive layer 13. The functional layer 12 may also be located directly on the substrate 11. The functional layer 12 has a first functional layer surface 12a and a second functional layer surface 12b. The first functional layer surface 12a is in contact with the second substrate surface 11b of the substrate 11. The second functional layer surface 12b is on the opposite side of the first functional layer surface 12a and is located on the adhesive layer 13 side. The functional layer 12 imparts various functions to the fiber-reinforced plastic molded product 30. The functional layer 12 remains on the fiber-reinforced plastic molded product 30 after the functional film 10 has been adhered to the prepreg 31. The functional layer 12 may also be called a surface protection layer.

[0049] The functional layer 12 is a layer that constitutes the surface layer of the fiber-reinforced plastic molded product 30 obtained after being transferred onto the prepreg 31, which is the transfer target, via the adhesive layer 14. The functional layer 12 contains a weather-resistant agent and has weather resistance. In addition to weather resistance, the functions of the functional layer 12 may also include scratch resistance, smoothness, design properties, decorative properties, stain resistance, water repellency, chemical resistance, flame retardancy, gas resistance, snow removal properties, insulation properties, abrasion resistance, electromagnetic wave shielding properties, lightning strike resistance, humidity shielding properties, and / or gas shielding properties.

[0050] In one embodiment, the functional layer 12 contains a cured product of a curable resin. In one embodiment, the functional layer 12 is composed of a cured product of a curable resin composition containing a curable resin. This can improve, for example, weather resistance and scratch resistance.

[0051] Examples of curable resins include thermosetting resins and ionizing radiation-curable resins. Among these, ionizing radiation-curable resins are preferred from the viewpoint of improving weather resistance and scratch resistance.

[0052] Examples of thermosetting resins include unsaturated polyester, thermosetting polyurethane, thermosetting (meth)acrylic resin, epoxy resin, aminoalkyd resin, melamine resin, guanamine resin, and urea resin.

[0053] Ionizing radiation-curable resins are resins that harden upon irradiation with ionizing radiation. Examples of ionizing radiation include electromagnetic waves such as ultraviolet rays (UV), X-rays, and gamma rays; and charged particle beams such as electron beams (EB), alpha rays, and ion beams. Among these, ultraviolet rays and electron beams are preferred, and electron beams are more preferred. In other words, the functional layer 12 is preferably a resin layer in which the curable resin has been hardened by electron beam irradiation.

[0054] Examples of ionizing radiation-curable resins include polymerizable oligomers and polymerizable prepolymers. Examples of polymerizable oligomers and polymerizable prepolymers include oligomers and prepolymers having polymerizable unsaturated groups such as ethylenically unsaturated groups in the molecule. Specifically, examples include urethane (meth)acrylates such as polyether-based urethane (meth)acrylate, polycarbonate-based urethane (meth)acrylate, polyester-based urethane (meth)acrylate, and caprolactone-based urethane (meth)acrylate, as well as epoxy (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, acrylic (meth)acrylate, and polybutadiene (meth)acrylate. Among these, urethane (meth)acrylate is preferred. Examples of ethylenically unsaturated groups include (meth)acryloyl groups, vinyl groups, and allyl groups. In this disclosure, "(meth)acrylate" encompasses both "acrylate" and "methacrylate," and "(meth)acryloyl group" encompasses both "acryloyl group" and "methacryloyl group."

[0055] As polymerizable oligomers and polymerizable prepolymers, polyfunctional oligomers and polyfunctional prepolymers having multiple polymerizable unsaturated groups in the molecule are preferred. The number of polymerizable unsaturated groups is preferably 2 to 15, more preferably 2 to 8, and even more preferably 2 to 6, from the viewpoint of improving scratch resistance and minimizing curing shrinkage.

[0056] In addition to polymerizable oligomers and polymerizable prepolymers, polyfunctional (meth)acrylate monomers having two or more (meth)acryloyl groups in the molecule can also be used as ionizing radiation-curable resins. Examples of polyfunctional (meth)acrylate monomers include aliphatic monomers such as trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate; monomers having an isocyanurate skeleton such as tris(2-(meth)acryloxyethyl) isocyanurate; and modified versions thereof.

[0057] Examples of the above-mentioned modified compounds include ethylene oxide (EO) modified compounds, propylene oxide (PO) modified compounds, and caprolactone (CL) modified compounds. Specifically, examples of the above-mentioned modified compounds include EO-modified trimethylolpropane tri(meth)acrylate, PO-modified trimethylolpropane tri(meth)acrylate, EO-modified dipentaerythritol hexa(meth)acrylate, PO-modified dipentaerythritol hexa(meth)acrylate, CL-modified dipentaerythritol hexa(meth)acrylate, and CL-modified tris(2-(meth)acryloxyethyl) isocyanurate.

[0058] The content of cured resin in the functional layer 12 is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more. This allows for further improvement of the weather resistance and scratch resistance of the functional layer 12, for example.

[0059] When using an ultraviolet-curable resin as the ionizing radiation-curable resin, it is preferable to use a photopolymerization initiator together with the ultraviolet-curable resin. Examples of photopolymerization initiators include acetophenone compounds, benzoin compounds, acylphosphine oxide compounds, benzophenone compounds, thioxanthone compounds, and aminobenzophenone compounds. The amount of photopolymerization initiator used is preferably 0.1 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the ultraviolet-curable resin.

[0060] Monofunctional (meth)acrylates such as methyl (meth)acrylate may be used as diluents for purposes such as adjusting the viscosity of the curable resin composition. In addition to monofunctional (meth)acrylates, ordinary organic solvents may also be used as diluents.

[0061] The functional layer 12 contains a weather-resistant agent. The weather-resistant agent may also be called a weather-resistance enhancer. Since the fiber-reinforced plastic molded product 30 is exposed to direct sunlight and wind and rain on a daily basis, it is desirable that it has excellent weather resistance. By using a weather-resistant agent, for example, the weather resistance of the functional layer 12 can be improved, thereby suppressing deterioration and yellowing of the resin constituting the functional layer 12, improving interlayer adhesion, and protecting the lower layers (e.g., adhesive layer 13, bonding layer 14, prepreg 31), for example, by suppressing deterioration, fading, and yellowing. As a result, the fiber-reinforced plastic molded product 30 can be used outdoors for a long period of time.

[0062] Examples of weather-resistant agents include ultraviolet absorbers and light stabilizers. Ultraviolet absorbers absorb harmful ultraviolet rays and improve the long-term weather resistance of the fiber-reinforced plastic molded product 30. Light stabilizers themselves absorb very little ultraviolet light, but they efficiently capture harmful free radicals generated by ultraviolet light.

[0063] Examples of UV absorbers include organic UV absorbers such as benzotriazole-based UV absorbers, triazine-based UV absorbers, benzophenone-based UV absorbers, oxybenzophenone-based UV absorbers, salicylic acid ester-based UV absorbers, and cyano(meth)acrylate-based UV absorbers; and inorganic UV absorbers such as titanium dioxide, cerium oxide, and zinc oxide. Among these, organic UV absorbers are preferred, and triazine-based UV absorbers are more preferred.

[0064] Examples of triazine-based UV absorbers include hydroxyphenyltriazine-based UV absorbers. Examples of hydroxyphenyltriazine-based UV absorbers include 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, and 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine Examples include 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-[2-(2-ethylhexanoyloxy)ethoxy]phenol, and 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine.

[0065] The amount of UV absorber in the solid content of the curable resin composition and in the functional layer 12 is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 7% by mass or less, and even more preferably 0.3% by mass or more and 5% by mass or less. This can improve, for example, the weather resistance of the functional layer 12. If the amount of UV absorber is below the upper limit, it is possible to suppress, for example, a decrease in the transparency of the functional layer 12 and a decrease in the adhesion between the functional layer 12 and the adhesive layer 13 due to the bleeding out of the UV absorber.

[0066] Examples of light stabilizers include hindered amine light stabilizers (HALS). Examples of hindered amine light stabilizers include 1,2,2,6,6-pentamethyl-4-piperidinyl (meth)acrylate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, and 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidine-4- Examples include yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine, 2-(3,5-di-tert-butyl-4-hydroxybenzyl)-2'-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl), bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1-octyroxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, and tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetracarboxylate.

[0067] The content of the light stabilizer in the solids of the curable resin composition and in the functional layer 12 is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.1% by mass or more and 7% by mass or less, and even more preferably 0.3% by mass or more and 5% by mass or less. This can improve, for example, the weather resistance of the functional layer 12. If the content of the light stabilizer is below the upper limit, for example, a decrease in the transparency of the functional layer 12 and a decrease in the adhesion between the functional layer 12 and the adhesive layer 13 due to the bleed-out of the light stabilizer can be suppressed.

[0068] The functional layer 12 may contain additives. Examples of additives include polymerization inhibitors, crosslinking agents, antistatic agents, adhesion improvers, antioxidants, leveling agents, thixotropic agents, coupling agents, plasticizers, antifouling agents, defoaming agents, and fillers.

[0069] Examples of fillers include organic particles and inorganic particles. Examples of organic particles include synthetic resin particles such as (meth)acrylic resin particles, polycarbonate resin particles, and styrene resin particles. Examples of inorganic particles include silica, alumina, zirconia, titania, kaolinite, iron oxide, diamond, and silicon carbide.

[0070] The curable resin composition may contain an organic solvent, for example, to improve its applicability. Examples of organic solvents include hydrocarbon solvents such as toluene, xylene, hexane, and octane; alcohol solvents such as ethanol, propanol, butanol, pentanol, hexanol, octanol, and decanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; and ester solvents such as ethyl acetate, butyl acetate, ethyl butyrate, butyl butyrate, butyl stearate, methyl benzoate, methyl lactate, ethyl lactate, and butyl lactate.

[0071] The thickness of the functional layer 12 is preferably 5 μm to 100 μm, more preferably 10 μm to 80 μm, and even more preferably 15 μm to 50 μm. This allows for excellent water repellency, oil repellency, weather resistance, and scratch resistance to be imparted to the fiber-reinforced plastic molded product 30, for example. In this disclosure, the thickness of each layer can be measured by scanning electron microscope (SEM) images of the cross-section of each layer.

[0072] <Adhesive layer> The adhesive layer 13 is located between the functional layer 12 and the adhesion layer 14. The adhesive layer 13 may also be located directly on the functional layer 12. The adhesive layer 13 has a first adhesive surface 13a and a second adhesive surface 13b. The first adhesive surface 13a is in contact with the second functional surface 12b of the functional layer 12. The second adhesive surface 13b is on the opposite side of the first adhesive surface 13a and is located on the adhesion layer 14 side. The adhesive layer 13 is a layer that enhances the adhesion between the functional layer 12 and the adhesion layer 14. In this specification, "adhesion" means a state in which two surfaces are joined together by chemical, physical, and / or mechanical forces accompanied by a curing reaction. The adhesive layer 13 remains on the fiber-reinforced plastic molded product 30 after the functional film 10 has been adhered to the prepreg 31. The adhesive layer 13 may also be called a primer layer. The adhesive layer 13 is not necessarily required.

[0073] The adhesive layer 13 contains a resin material. Examples of resin materials include (meth)acrylic resin, urethane resin, butyral resin, polyolefin, chlorinated polyolefin, vinyl chloride-vinyl acetate copolymer, and polyester. Among these, urethane resin is preferred.

[0074] As for the urethane resin, a urethane resin having a (meth)acrylic skeleton in the polyurethane polymer chain is preferred from the viewpoint of weather resistance and durability. Examples of urethane resins having a (meth)acrylic skeleton in the polyurethane polymer chain include urethane (meth)acrylic copolymers, which are copolymers of a urethane component and a (meth)acrylic component, and resins in which a (meth)acrylic resin having a hydroxyl group or isocyanate group as the polyol component or polyisocyanate component constituting the polyurethane is used. Among these, urethane (meth)acrylic copolymers are preferred, and as urethane (meth)acrylic copolymers, for example, urethane (meth)acrylic block copolymers are preferred.

[0075] From the viewpoint of adhesion between the adhesive layer 13 and the functional layer 12, the urethane (meth)acrylic copolymer may further have a polycarbonate backbone or a polyester backbone in the polyurethane polymer chain. Examples of such urethane (meth)acrylic copolymers include polycarbonate-based urethane (meth)acrylic copolymers, which are copolymers of a polycarbonate-based urethane component and a (meth)acrylic component, and polyester-based urethane (meth)acrylic copolymers, which are copolymers of a polyester-based urethane component and a (meth)acrylic component.

[0076] Urethane (meth)acrylic copolymers can be obtained, for example, by reacting a polyol and a polyisocyanate with a (meth)acrylic resin having at least two hydroxyl groups in one molecule (see Japanese Patent Publication No. 6-100653, etc.) or by reacting a (meth)acrylic monomer with a urethane prepolymer having unsaturated double bonds at both ends (see Japanese Patent Publication No. 10-1524, etc.).

[0077] Examples of urethane prepolymers include polycarbonate-based urethane prepolymers obtained by reacting a polycarbonate diol with a diisocyanate, and polyester-based urethane prepolymers obtained by reacting a polyester diol with a diisocyanate. Examples of diisocyanates include aliphatic isocyanates such as hexamethylene diisocyanate, and alicyclic isocyanates such as isophorone diisocyanate and hydrogenated xylylene diisocyanate. Examples of (meth)acrylic monomers include (meth)acrylic acid and alkyl (meth)acrylate esters with an alkyl group having 1 to 6 carbon atoms.

[0078] Examples of urethane resins include polycarbonate-based urethane (meth)acrylic copolymers, polyester-based urethane (meth)acrylic copolymers, polyether-based urethane (meth)acrylic copolymers, and caprolactone-based urethane (meth)acrylic copolymers. These resin materials are preferred from the viewpoint of improving weather resistance and the adhesion between the functional layer 12 and the adhesive layer 14.

[0079] In urethane resins, the urethane component / (meth)acrylic component (mass ratio) is preferably 20 / 80 to 99 / 1, more preferably 50 / 50 to 95 / 5, and even more preferably 70 / 30 to 95 / 5. This can, for example, further improve weather resistance. The (meth)acrylic component content in a urethane resin is the ratio of monomer units constituting the (meth)acrylic skeleton to the total mass of the urethane resin. The (meth)acrylic component content in a urethane resin is calculated by measuring the NMR spectrum of the urethane resin and determining the ratio of the peak area attributed to the (meth)acrylic component to the total peak area.

[0080] The weight-average molecular weight of the urethane resin is preferably 10,000 to 100,000, more preferably 30,000 to 80,000. This allows for improved weather resistance, for example. The weight-average molecular weight used herein is determined by gel permeation chromatography (GPC) as a standard polystyrene equivalent.

[0081] The resin material content in the adhesive layer 13 is, for example, 50% by mass or more.

[0082] The adhesive layer 13 may further contain particles. This can suppress the occurrence of blocking phenomena, such as the adhesion layer 14 and the substrate 11 sticking together, during the production process or storage of the functional film 10.

[0083] Examples of particles include inorganic particles and organic particles. Examples of inorganic particles include silica, alumina, aluminum hydroxide, barium sulfate, calcium carbonate, and talc.

[0084] Examples of particle shapes include spherical, ellipsoidal, polyhedral, and scaly.

[0085] The average particle diameter is preferably 0.1 μm to 10 μm, more preferably 0.5 μm to 8 μm, and even more preferably 0.5 μm to 5 μm. When the average particle diameter is within the above range, transparency is ensured and excellent blocking prevention properties are obtained.

[0086] The particle content in the adhesive layer 13 is preferably 0.1 parts by mass or more and 30 parts by mass or less, more preferably 1 part by mass or more and 25 parts by mass or less, and even more preferably 3 parts by mass or more and 20 parts by mass or less, per 100 parts by mass of resin material.

[0087] The adhesive layer 13 may contain additives. Examples of additives include weathering agents, abrasion resistance enhancers, infrared absorbers, antistatic agents, adhesion enhancers, leveling agents, thixotropic agents, coupling agents, plasticizers, defoamers, fillers, and colorants.

[0088] The adhesive layer 13 may contain weather-resistant agents. This can improve the weather resistance of the adhesive layer 13, for example, allowing the resulting fiber-reinforced plastic molded product 30 to be used outdoors for extended periods. Examples of weather-resistant agents include ultraviolet absorbers and light stabilizers. Details of the ultraviolet absorbers and light stabilizers are as described above.

[0089] The amount of ultraviolet absorber is preferably 0.1 parts by mass or more and 50 parts by mass or less, more preferably 3 parts by mass or more and 40 parts by mass or less, and even more preferably 5 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the resin material constituting the adhesive layer 13.

[0090] The amount of light stabilizer is preferably 0.1 parts by mass or more and 15 parts by mass or less, more preferably 1 part by mass or more and 15 parts by mass or less, and even more preferably 3 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the resin material constituting the adhesive layer 13.

[0091] The resin composition for the adhesive layer 13 may contain, for example, an isocyanate curing agent to promote the curing of the resin material. Examples of isocyanate curing agents include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, cyclohexanephenylene diisocyanate, and naphthalene-1,5-diisocyanate.

[0092] The amount of isocyanate curing agent used in the resin composition for the adhesive layer 13 is preferably 1 to 40 parts by mass, more preferably 3 to 30 parts by mass, and even more preferably 5 to 30 parts by mass, per 100 parts by mass of resin material, from the viewpoint of improving the adhesion between the functional layer 12 and the adhesive layer 14.

[0093] The thickness of the adhesive layer 13 is preferably 0.1 μm or more and 20 μm or less, more preferably 1 μm or more and 10 μm or less. This allows for improved adhesion between, for example, the functional layer 12 and the adhesion layer 14. It is preferable that the thickness of the adhesive layer 13 is less than the thickness of the adhesion layer 14.

[0094] <Close-up layer> The adhesion layer 14 is located on the prepreg 31 side. The adhesion layer 14 may also be located directly on the adhesive layer 13. The adhesion layer 14 has an adhesion layer first surface 14a and an adhesion layer second surface 14b. The adhesion layer first surface 14a is in contact with the adhesive layer second surface 13b of the adhesive layer 13. The adhesion layer second surface 14b is on the opposite side of the adhesion layer first surface 14a and is located on the prepreg 31 side. The adhesion layer second surface 14b is in contact with the prepreg 31. The adhesion layer 14 is a layer that enhances the adhesion between the functional film 10 and the prepreg 31. In this specification, "adhesion" refers to a broad term of adhesion phenomenon that joins two surfaces without involving not only curing reactions like adhesives, but also chemical reactions such as pressure sensitivity or thermal melting. The adhesion layer 14 remains on the fiber-reinforced plastic molded product 30 after the functional film 10 has been adhered to the prepreg 31. The adhesion layer 14 is not necessarily required.

[0095] The adhesion layer 14 has the function of adhering the functional film 10 to the surface of the prepreg 31. In one embodiment, the adhesion layer 14 constitutes the surface layer of the transfer layer 15 on the side opposite to the substrate 11. The adhesion layer 14 is the layer that comes into contact with the prepreg 31 after transfer. This allows the transfer layer 15 to be transferred and attached to the prepreg 31 smoothly.

[0096] In this disclosure, the functional film 10 is attached to the prepreg 31 such that the adhesive layer 14 is in contact with the surface of the prepreg 31, and then the substrate 11 is peeled off, thereby allowing the functional layer 12 to be transferred from the functional film 10 onto the prepreg 31 with good adhesion.

[0097] Suitable adhesive resins for use in the adhesion layer 14 include, for example, heat-sealable resins such as (meth)acrylic resin, polyolefin, chlorinated polyolefin, acid-modified polyolefin, vinyl chloride-vinyl acetate copolymer, polyamide, polyester, chlorinated rubber, urethane resin, epoxy resin, and styrene resin. Among these, (meth)acrylic resins such as polymethyl methacrylate are preferred from the viewpoint of improving weather resistance.

[0098] The content of the adhesive resin in the adhesion layer 14 is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more.

[0099] The adhesion layer 14 may contain additives. Examples of additives include UV absorbers and light stabilizers, weathering agents such as antioxidants, abrasion resistance improvers, infrared absorbers, antistatic agents, adhesion improvers, leveling agents, thixotropic agents, coupling agents, plasticizers, defoamers, fillers, and colorants.

[0100] The adhesion layer 14 may contain a weather-resistant agent. Details of the weather-resistant agent are as described above. The amount of ultraviolet absorber in the adhesion layer 14 may be 0.1 parts by mass or more and 25 parts by mass or 1 part by mass or 20 parts by mass or 3 parts by mass or more and 15 parts by mass or less per 100 parts by mass of adhesive resin. The amount of light stabilizer in the adhesion layer 14 may be 0.1 parts by mass or more and 20 parts by mass or 0.5 parts by mass or 15 parts by mass or 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of adhesive resin. The amount of antioxidant in the adhesion layer 14 may be 0 parts by mass or more and 20 parts by mass or 0.5 parts by mass or more and 15 parts by mass or 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of adhesive resin.

[0101] The thickness of the adhesion layer 14 is preferably 1 μm to 50 μm, more preferably 5 μm to 40 μm. This allows, for example, the transfer layer 15 to adhere well to the prepreg 31 and ensures excellent transparency.

[0102] The thickness of the adhesion layer 14 is preferably greater than the thickness of the adhesive layer 13.

[0103] The resin included in the adhesion layer 14 may be selected to match the material of the matrix resin of the prepreg 31. If the matrix resin of the prepreg 31 is a thermoplastic resin such as a polypropylene resin, the resin included in the adhesion layer 14 may be an olefin resin. If the matrix resin of the prepreg 31 is an epoxy resin, the resin included in the adhesion layer 14 may be a thermosetting resin such as an acrylic resin, a urethane resin, or an epoxy resin. If the matrix resin of the prepreg 31 is a urethane acrylate resin, the resin included in the adhesion layer 14 may be a thermosetting resin such as an acrylic resin, a urethane resin, or an epoxy resin. By selecting the resin included in the adhesion layer 14 and the matrix resin of the prepreg 31 from the above resins, the adhesion between the matrix resin and the functional film 10 can be improved.

[0104] <Other> The functional film 10 of this disclosure may further have a design layer. This allows, for example, the prepreg 31, which is the transfer target, to be further given design properties in addition to weather resistance. The transfer layer 15 may have a design layer between the adhesive layer 13 and the adhesion layer 14.

[0105] The design layer includes, for example, a pattern. Examples of patterns include letters, figures, symbols, and combinations thereof. The pattern may be a solid color (a so-called solid image). The design layer may be placed on a part of the surface of the adhesive layer 13 opposite to the functional layer 12, or it may be placed over the entire surface. The design layer may be a layer that covers the entire surface of the surface of the adhesive layer 13 opposite to the functional layer 12, or it may be a pattern that includes areas where the pattern is placed and areas where it is not placed on the surface of the adhesive layer 13 opposite to the functional layer 12.

[0106] In one embodiment, the design layer contains a resin material and a colorant. Examples of resin materials include (meth)acrylic resin, polyolefin, chlorinated polyolefin, acid-modified polyolefin, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-(meth)acrylic copolymer, polystyrene, polyester, polyurethane, polyamide, butyral resin, and cellulose resin.

[0107] Examples of colorants include pigments and dyes. Specifically, these include inorganic pigments such as carbon black, iron black, titanium white, antimony white, lead yellow, titanium yellow, iron oxide, cadmium red, ultramarine, and cobalt blue; organic pigments or dyes such as quinacridone red, isoindolinone yellow, phthalocyanine blue, azomethine azoblack, and nickel azo complexes; metallic pigments consisting of flaky foil pieces such as aluminum and brass; and pearlescent pigments consisting of flaky foil pieces such as titanium dioxide-coated mica and basic lead carbonate.

[0108] The amount of colorant in the design layer is preferably 10 to 500 parts by mass, more preferably 30 to 300 parts by mass, and even more preferably 50 to 200 parts by mass, per 100 parts by mass of resin material contained in the design layer.

[0109] The design layer may contain additives. Examples of additives include weathering agents such as ultraviolet absorbers and light stabilizers, abrasion resistance enhancers, infrared absorbers, antistatic agents, adhesion enhancers, leveling agents, thixotropic agents, coupling agents, plasticizers, defoamers, and fillers.

[0110] The design layer may be transparent, semi-transparent, or opaque. Examples of methods for forming the design layer include known printing methods such as gravure printing, offset printing, screen printing, transfer printing from transfer sheets, sublimation transfer printing, and inkjet printing.

[0111] The thickness of the design layer is preferably 0.5 μm to 20 μm, more preferably 1 μm to 15 μm, and even more preferably 2 μm to 10 μm. This can improve the design of the transfer layer 15, for example. The adhesion layer 14 may also serve as the design layer.

[0112] Each layer of the functional film 10 (substrate 11, functional layer 12, adhesive layer 13, and bonding layer 14) preferably has good stretchability. Specifically, the elongation at break of each layer of the functional film 10 at 130°C may be 1% to 400%, more preferably 5% to 300%, and even more preferably 10% to 200%. By having an elongation at break of 1% to 400% of each layer of the functional film 10 at 130°C, it is possible to suppress the transfer layer 15 from cracking due to being unable to follow the stretching of the prepreg 31 during molding with the heating press machine 70 described later.

[0113] The elongation at break of each layer of the functional film 10 is measured and calculated using the Tensilon universal material tester of A&D Co., Ltd., in the shape of test specimen type 5, based on JIS K7127, at a test speed of 10 mm / min.

[0114] The elastic modulus of each layer of the functional film 10 at 130°C may be 0.01 GPa or more and 10 GPa or less, more preferably 0.05 GPa or more and 5 GPa or less, and even more preferably 0.1 GPa or more and 3 GPa or less. By having an elastic modulus of 0.01 GPa or more and 10 GPa or less of each layer of the functional film 10 at 130°C, it is possible to suppress the transfer layer 15 from cracking due to being unable to follow the stretching of the prepreg 31 during molding with the heating press machine 70 described later.

[0115] The elastic modulus of each layer of the functional film 10 is measured and calculated using the Tensilon universal material tester of A&D Co., Ltd., in the shape of test specimen type 5, based on JIS K7127, at a test speed of 10 mm / min.

[0116] (Composition of fiber-reinforced plastic molded products) Figure 2 illustrates the structure of the fiber-reinforced plastic molded product according to this embodiment.

[0117] The fiber-reinforced plastic molded product 30 shown in Figure 2 includes a prepreg 31 and a transfer layer 15 placed on the prepreg 31. The transfer layer 15 is in close contact with and bonded to the prepreg 31. The transfer layer 15 includes a functional layer 12, an adhesive layer 13, and a bonding layer 14 (Figure 1). The configuration of the transfer layer 15 is the same as that of the transfer layer 15 of the functional film 10 described above.

[0118] In Figure 2, multiple prepregs 31 are laminated in layers. The fiber-reinforced plastic molded product 30 is a molded product that achieves the desired strength by laminating and molding multiple prepregs 31. The laminated multiple prepregs 31 may also be called FRP (Fiber Reinforced Plastics) or FRTP (fiber-reinforced thermoplastic).

[0119] The prepreg 31 is layered on the transfer layer 15. The prepreg 31 is a lightweight and tough substrate. The prepreg 31 is manufactured by weaving reinforcing fibers such as carbon fibers or glass fibers, impregnating them with a matrix resin such as a thermoplastic resin or a thermosetting resin, and then curing it. Multiple layers of prepreg 31 may be stacked. The prepreg 31 has a three-dimensional, fine weave pattern. Due to the weave pattern, an uneven surface is formed on the surface of the prepreg 31. The thickness of each prepreg 31 is, for example, 0.03 mm to 5 mm.

[0120] The weave pattern formed on the prepreg 31 may be, for example, a unidirectional long fiber, a bidirectional fabric, a multiaxial fabric, a nonwoven fabric, a mat, a knit, or a braid. A long fiber means, for example, a continuous single fiber or fiber bundle of 10 mm or more.

[0121] The reinforcing fibers may be carbon fibers, glass fibers, aramid fibers, polyethylene fibers, or natural fibers (kenaf, hemp). When carbon fibers are used as reinforcing fibers, they may be, for example, polyacrylonitrile-based carbon fibers, pitch-based carbon fibers, or mixtures thereof. The orientation of the reinforcing fibers in multiple prepregs 31 may differ between adjacent prepregs 31.

[0122] The matrix resin is, for example, a thermosetting resin, a thermoplastic resin, or a thermoplastic elastomer. Examples of thermosetting resins include epoxy resins, unsaturated polyester resins, phenolic resins, silicone resins, urethane resins, polyimide resins, and vinyl ester resins. Examples of thermoplastic resins include polysulfone, polyethersulfone, polyetherimide, polyimide, polypropylene, polyamide, polycarbonate, ABS resin, polyphenylene sulfide, polyetheretherketone, and polylactic acid.

[0123] (Construction of the intermediate) Figure 3 shows an intermediate 40 according to this embodiment. The intermediate 40 includes a prepreg 31 and a functional film 10 disposed on the prepreg 31. The functional film 10 includes a substrate 11 and a transfer layer 15 laminated on the substrate 11 (Figure 1). The transfer layer 15 is in close contact with and bonded to the prepreg 31. The transfer layer 15 includes a functional layer 12, an adhesive layer 13, and an adhesion layer 14. The configuration of the functional film 10 is the same as the configuration of the functional film 10 described above.

[0124] The intermediate 40 is used in the production of the fiber-reinforced plastic molded product 30. The intermediate 40 is prepared in advance, and then one or more layers of prepreg 31 are laminated and bonded to the intermediate 40 to obtain the fiber-reinforced plastic molded product 30. The intermediate 40 contains one layer of prepreg 31, but may also contain multiple layers of prepreg 31.

[0125] (Method of manufacturing functional films) Next, with reference to Figures 4(A)-(D), the manufacturing method of the functional film 10 (Figure 1) described above will be explained.

[0126] First, the substrate 11 is prepared as shown in Figure 4(A). The substrate 11 may be surface-treated beforehand. Examples of surface treatment methods include corona discharge treatment and mold release treatment. Corona discharge treatment is a treatment that improves the adhesion between the substrate 11 and the functional layer 12. Mold release treatment is a treatment that makes it easier to release the substrate 11 from the functional layer 12 after the functional film 10 has been brought into close contact with the prepreg 31.

[0127] Next, as shown in Figure 4(B), a functional layer 12 is formed on the substrate 11.

[0128] The functional layer 12 is formed, for example, as follows: A curable resin composition is applied to the substrate 11 to a desired thickness, and if an organic solvent is used, it is dried to remove the organic solvent and form a coating film (uncured resin layer). The drying conditions are, for example, 40°C to 120°C for 10 seconds to 10 minutes. Next, if a thermosetting resin is used, the coating film is heated to the temperature required for curing to cure it. If an ionizing radiation curable resin is used, the coating film is irradiated with ionizing radiation to cure it. In this way, the functional layer 12 can be formed. The curing treatment may be performed after the application of the curable resin composition and before the formation of other layers, or after the formation of other layers.

[0129] Methods for applying the curable resin composition onto the substrate 11 include, for example, the dipping method, flow coating method, spray method, spin coating method, gravure coating method, microgravure coating method, die coating method, slit reverse coating method, roll coating method, reverse roll coating method, comma coating method, blade coating method, air knife coating method, offset method, and bar coating method.

[0130] When using an electron beam as the ionizing radiation, the acceleration voltage can be appropriately selected depending on the resin used and the thickness of the layer, but it is preferable to cure the uncured resin layer with an acceleration voltage of 70kV to 300kV. The electron beam irradiation dose is preferably 0.5Mrad to 30Mrad, more preferably 1Mrad to 20Mrad, and even more preferably 3Mrad to 15Mrad.

[0131] As electron sources, various types of electron beam accelerators can be used, such as Cockcroft-Walton type, Van de Graft type, resonant transformer type, insulated core transformer type, or linear type, dynamitron type, and high-frequency type.

[0132] When using ultraviolet light as the ionizing radiation, it is preferable to irradiate with ultraviolet light with a wavelength of 190 nm to 400 nm, for example. Examples of ultraviolet light sources include xenon lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, carbon arc lamps, and tungsten lamps. The irradiation light intensity is, for example, 100 mJ / cm². 2 More than 800mJ / cm 2 The following applies:

[0133] Next, as shown in Figure 4(C), an adhesive layer 13 is formed on the functional layer 12.

[0134] The adhesive layer 13 can be formed, for example, by applying a resin composition for the adhesive layer 13 containing the above-mentioned components and optionally an organic solvent onto the functional layer 12 by a known printing or coating method, and then drying and curing it as necessary.

[0135] To improve the adhesion between the functional layer 12 and the adhesive layer 13, the functional layer 12 may be surface-treated before the formation of the adhesive layer 13. Examples of surface treatment methods include corona discharge treatment, plasma treatment, chromium oxidation treatment, flame treatment, hot air treatment, and ozone / ultraviolet treatment.

[0136] To improve the adhesion between the functional layer 12 and the adhesive layer 13, the crosslinking and curing of the functional layer 12 may be left in a semi-cured state. After that, the resin composition for the adhesive layer 13 may be applied to the semi-cured functional layer 12, and then the functional layer 12 may be fully cured by irradiation with ionizing radiation.

[0137] Subsequently, as shown in Figure 4(D), an adhesion layer 14 is formed on the adhesive layer 13.

[0138] The adhesion layer 14 can be formed, for example, by applying a composition containing the components that make up the adhesion layer 14 (composition for the adhesion layer 14) onto the functional layer 12 or adhesive layer 13, and drying it as necessary.

[0139] The functional film 10 of this disclosure may have a cover film (protective film) on the adhesive layer 14. Specifically, the cover film may be attached to the adhesive layer 14. This is preferable for storing the functional film 10 as it provides good protection for the surface of the adhesive layer 14. When using the functional film 10, the cover film is peeled off from the adhesive layer 14 to expose the adhesive layer 14. Then, the functional film 10 is attached to the prepreg 31 via the exposed adhesive layer 14.

[0140] The cover film is made of a resin material such as polyolefin or polyester.

[0141] (Method for manufacturing fiber-reinforced plastic molded products) Next, the manufacturing method of the fiber-reinforced plastic molded product 30 (Figure 2) described above will be explained with reference to Figures 5(A)-(C). Note that in Figures 5(A)-(C), for convenience, the thickness of each layer of the functional film 10 is shown as being greater than the thickness of the prepreg 31.

[0142] First, as shown in Figure 5(A), a functional film 10 is prepared, comprising a base material 11, a functional layer 12, an adhesive layer 13, and an adhesion layer 14. Additionally, multiple prepregs 31 are prepared as transfer targets.

[0143] Next, as shown in Figure 5(B), the functional film 10 and the multiple prepregs 31 are laminated together. At this time, the adhesion layer 14 of the functional film 10 comes into contact with the prepregs 31. Subsequently, the laminated functional film 10 and the multiple prepregs 31 are heat-pressed. This heats and pressurizes the functional film 10 and the multiple prepregs 31, and hardens them to form the structure.

[0144] During this time, as shown in Figure 6, the functional film 10 and the multiple prepregs 31 are placed on the lower die 71 of the heating press machine 70. Next, the upper die 72 of the heating press machine 70 descends, pressurizing and heating the functional film 10 and the multiple prepregs 31 between the upper die 72 and the lower die 71. The pressure applied to the functional film 10 and the multiple prepregs 31 at this time is, for example, 0.1 MPa or more and 20 MPa or less. By heating and pressurizing the functional film 10 and the multiple prepregs 31, the functional film 10 and the multiple prepregs 31 are integrally joined together. The temperature at which the functional film 10 and the multiple prepregs 31 are heated may be, for example, 100°C or more and 300°C or less. The heating time for the functional film 10 and the multiple prepregs 31 may be, for example, 1 minute or more and 120 minutes or less. The functional film 10 and the multiple prepregs 31 may be cooled after heating.

[0145] In Figure 6, the functional film 10 is in contact with the lower die 71 of the heating press machine 70. The base material 11 of the functional film 10 does not adhere well to the lower die 71. Therefore, there is no need to apply a release agent to the lower die 71 or to place a separate release film. Alternatively, the functional film 10 may be placed on both sides of multiple prepregs 31. That is, the functional film 10 may be in contact with both the upper die 72 and the lower die 71 of the heating press machine 70. In this case, there is no need to apply a release agent to both the upper die 72 and the lower die 71 or to place a release film.

[0146] Subsequently, as shown in Figure 5(C), the substrate 11 is peeled off from the functional layer 12 to obtain a fiber-reinforced plastic molded product 30 containing the prepreg 31 and the transfer layer 15.

[0147] (Variations in the manufacturing method of fiber-reinforced plastics) Next, with reference to Figures 7(A)-(E), a modified example of the manufacturing method of the fiber-reinforced plastic molded product 30 (Figure 2) described above will be explained. In Figures 7(A)-(E), for convenience, the thickness of each layer of the functional film 10 is shown to be exaggerated compared to the thickness of the prepreg 31.

[0148] First, as shown in Figure 7(A), a functional film 10 is prepared, comprising a base material 11, a functional layer 12, an adhesive layer 13, and a bonding layer 14. Also, a single layer of prepreg 31 is prepared. Note that two or more layers of prepreg 31 may be laminated.

[0149] Next, as shown in Figure 7(B), the functional film 10 and the prepreg 31 are laminated. At this time, the adhesion layer 14 of the functional film 10 is positioned on the prepreg 31 side. In this case, for example, the functional film 10 and the prepreg 31 may be integrally joined by transfer molding of the functional film 10 onto the prepreg 31. Alternatively, the functional film 10 and the prepreg 31 may be integrally joined by attaching the functional film 10 to the prepreg 31. In this way, the intermediate 40 is obtained.

[0150] Next, as shown in Figure 7(C), the intermediate 40 and the multiple layers of prepreg 31 are laminated. At this time, the prepreg 31 of the intermediate 40 is located on the side of the multiple layers of prepreg 31.

[0151] Next, as shown in Figure 7(D), the laminated intermediate 40 and the multiple layers of prepreg 31 are heat-pressed. This heats, pressurizes, and hardens the intermediate 40 and the multiple layers of prepreg 31, thereby forming them. When heating and pressurizing the intermediate 40 and the multiple layers of prepreg 31, the heating press machine 70 shown in Figure 6 may be used. In this way, by heating and pressurizing the intermediate 40 and the multiple layers of prepreg 31, the intermediate 40 and the multiple layers of prepreg 31 are integrally joined together.

[0152] Subsequently, as shown in Figure 7(E), the substrate 11 is peeled off from the functional layer 12 to obtain a fiber-reinforced plastic molded product 30 containing the prepreg 31 and the transfer layer 15.

[0153] As shown in the example in Figures 7(A)-(E), by using an intermediate 40 which has the functional film 10 and prepreg 31 integrated in advance, it is possible to suppress the occurrence of deformation such as wrinkles in the transfer layer 15 when molding using a heated press machine 70.

[0154] As described above, according to this embodiment, the functional film 10 for the fiber-reinforced plastic molded product 30 comprises a base material 11 and a functional layer 12. The functional layer 12 contains a weather-resistant agent. By including a weather-resistant agent in the functional layer 12, the weather resistance of the fiber-reinforced plastic molded product 30 can be enhanced when the fiber-reinforced plastic molded product 30 is used outdoors. In particular, even if the weather resistance of the matrix resin contained in the prepreg 31 is insufficient, the functional layer 12 covers the prepreg 31. Therefore, the durability of the fiber-reinforced plastic molded product 30 can be improved.

[0155] Furthermore, according to this embodiment, the fiber-reinforced plastic molded product 30 comprises a prepreg 31 and a functional layer 12. Since the prepreg 31 is covered by the functional layer 12, there is no need to perform a painting process when manufacturing the fiber-reinforced plastic molded product 30. Therefore, the manufacturing process of the fiber-reinforced plastic molded product 30 can be simplified. Specifically, several processes such as spray painting, polishing, and drying can be omitted. By simplifying the manufacturing process, the manufacturing cost of the fiber-reinforced plastic molded product 30 can be reduced. In addition, since the painting quality of the fiber-reinforced plastic molded product 30 does not vary, the appearance quality of the fiber-reinforced plastic molded product 30 is stabilized.

[0156] Furthermore, according to this embodiment, the functional film 10 is in contact with the upper die 72 and / or lower die 71 of the heated press machine 70 (Figure 6). This eliminates the need to apply a release agent or place a release film on the upper die 72 and / or lower die 71. As a result, the cost of release agents and release films can be reduced. The deterioration of the working environment caused by release agents can be suppressed. In addition, maintenance of the upper die 72 and / or lower die 71 can be simplified.

[0157] Furthermore, according to this embodiment, a fiber-reinforced plastic molded product 30 is manufactured by laminating a functional film 10 and a plurality of prepregs 31, and then heating and pressurizing them. By molding the functional film 10 and the plurality of prepregs 31 simultaneously, the prepregs 31 and the functional layer 12 adhere to each other easily. As a result, the functional layer 12 accurately follows the irregularities of the prepregs 31, and the prepregs 31 are covered, thereby ensuring the weather resistance of the fiber-reinforced plastic molded product 30.

[0158] The multiple components disclosed in the above embodiments and variations can be combined as needed. Alternatively, some components may be removed from all the components shown in the above embodiments and variations. [Explanation of symbols]

[0159] 10 Functional Films 11 Base material 12 Functional Layers 13 Adhesive layer 14. Contact layer 15 Transfer layer 30 Fiber-reinforced plastic molded products 31 Prepreg 40 Intermediates

Claims

1. A functional film for fiber-reinforced plastic molded products, Substrate and The substrate comprises a transfer layer laminated on the substrate, The transfer layer has a functional layer, The functional layer is a functional film containing a weather-resistant agent.

2. The functional film according to claim 1, wherein the transfer layer has an adhesion layer located on the opposite side of the functional layer from the substrate.

3. The functional film according to claim 2, wherein the transfer layer has an adhesive layer located between the adhesion layer and the functional layer.

4. The functional film according to claim 1, wherein the transfer layer has a design layer.

5. The functional film according to claim 1, wherein the total thickness of the transfer layer is 10 μm or more and 150 μm or less.

6. The functional film according to claim 1, wherein the melting point of the substrate is 80°C or higher and 300°C or lower.

7. The functional film according to claim 1, wherein the elongation at break of the substrate and the functional layer at 130°C is 1% or more and 400% or less.

8. The functional film according to claim 1, wherein the elastic modulus of the substrate and the functional layer at 130°C is 0.01 GPa or more and 10 GPa or less.

9. The functional film according to claim 1, wherein the surface roughness Sa of the surface of the substrate located on the functional layer side is 0.2 μm or less.

10. The functional film according to claim 1, wherein the surface roughness Sa of the surface of the substrate located on the functional layer side is 0.3 μm or more.

11. Prepreg and The prepreg comprises a transfer layer disposed on the prepreg, The transfer layer has a functional layer, The functional layer is a fiber-reinforced plastic molded product containing a weather-resistant agent.

12. The fiber-reinforced plastic molded article according to claim 11, wherein the transfer layer has an adhesion layer located on the prepreg side of the functional layer.

13. The fiber-reinforced plastic molded article according to claim 12, wherein the prepreg comprises a matrix resin, the matrix resin is a thermoplastic resin, and the resin contained in the adhesion layer is an olefin resin.

14. The fiber-reinforced plastic molded article according to claim 12, wherein the prepreg includes a matrix resin, the matrix resin is an epoxy resin or a urethane acrylate resin, and the resin contained in the adhesion layer is a thermosetting resin.

15. Prepreg and An intermediate comprising a functional film according to any one of claims 1 to 10 disposed on the prepreg.

16. A step of preparing a functional film according to any one of claims 1 to 10, The process of preparing the prepreg, A step of laminating the functional film and the prepreg, A step of integrally joining the functional film and the prepreg by heating and pressurizing the functional film and the prepreg, A method for manufacturing a fiber-reinforced plastic molded article, comprising the step of peeling off the substrate from the functional layer.

17. A step of preparing the intermediate according to claim 15, The process of preparing the prepreg, A step of laminating the intermediate and the prepreg, A step of integrally joining the intermediate and the prepreg by heating and pressurizing the intermediate and the prepreg, A method for manufacturing a fiber-reinforced plastic molded article, comprising the step of peeling off the substrate from the functional layer.

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