JP2012025144A - Embossed mold release paper, prepreg laminate, and method for producing fiber-reinforced composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide embossed mold release paper the embossed pattern of which can be transferred to the surface of a fiber-reinforced composite material and shaped, by molding the fiber-reinforced composite material while sticking the embossed mold release paper to the fiber-reinforced composite material, when molding fiber-reinforced composite material.SOLUTION: A prepreg laminate 30 has a prepreg 20 which is obtained by impregnating a reinforcing fiber 21 with a thermosetting resin 22 of an uncured or semi-cured state, and the mold release paper 10 on at least one surface of the prepreg 20. The embossed mold release paper 10 is obtained by layering a first mold release layer 17A, a first resin layer 15A, a first filler layer 13A, a support 11, a second filler layer 13B and a second resin layer 15B in this order from the side of the prepreg 20. The embossed pattern is formed on the first mold release layer 17A surface side of the first resin layer 15A.

Description

  The present invention relates to a release paper, and more particularly, when producing a fiber reinforced composite material from a prepreg, a release paper with an emboss for forming an embossed pattern on the surface of the fiber reinforced composite material, and a prepreg laminate, and The present invention relates to a method for producing a fiber-reinforced composite material.

  In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated. “UV” is an abbreviation, functional expression, common name, or industry term for “ultraviolet light” and “prepreg” is “fiber reinforced thermosetting resin prepreg”.

  Conventionally, fiber reinforced composite materials composed of reinforced fibers and thermosetting resins are lightweight and have good mechanical properties such as mechanical strength and elastic modulus. For sports and leisure such as fishing rods and golf shafts, space and aircraft, automobiles, etc. It is used for many members for general industrial applications such as transportation for ships and construction. Such a fiber reinforced composite material is obtained by, for example, impregnating a reinforced fiber such as carbon fiber or glass fiber with a thermosetting resin such as an epoxy resin to form an uncured or semi-cured sheet-like prepreg. Alternatively, a plurality of layers are laminated, heated and pressed, cured and molded to obtain a desired member (fiber reinforced composite material). In the present specification, the “fiber reinforced thermosetting resin prepreg” is simply referred to as a prepreg. The prepreg has a release paper on at least one side, and is manufactured in a form in which a protective film is stacked on the other side as needed. In this form, the prepreg is transported and stored, and immediately before the fiber-reinforced composite material is manufactured. The pattern paper is peeled off and used. However, the surface of the fiber reinforced composite material produced from the prepreg is a smooth surface, and the provision of the uneven pattern on the surface has not been considered. Even if it is intended to process the concavo-convex pattern, it is necessary to process it with a very expensive machine tool for precision processing, which is expensive. In addition, it is not suitable for processing fine irregularities such as satin or dimple pattern, and it takes a long time for processing.

  Therefore, it is a release paper with embossing for prepreg, and by molding the fiber reinforced composite material with the release paper with embossing applied at the time of molding, it is possible to release with embossing without going through the uneven processing process by the machine tool. There is a need for an embossed release paper that can shape a concavo-convex pattern by transferring the concavo-convex pattern of the pattern onto the surface of a fiber-reinforced composite material.

  Conventionally, the prepreg used when producing a fiber-reinforced composite material is usually held on one side by a release paper coated with silicone, and the other side holds the prepreg to prevent the adhesion of foreign matter. For example, it is covered with a protective film such as a polyethylene film. In order to process into a target fiber-reinforced composite material, it is cut into a desired pattern, the release paper and / or the protective film is peeled off, and the prepreg is overlaid. When air is sandwiched between the prepregs and the prepreg is cured in this state, the resulting fiber-reinforced composite material has voids in the air, resulting in a decrease in strength or a loss of function. In order to eliminate air trapping, air is removed by pressurization and talc is adhered to the surface of the prepreg. However, talc remains or mechanical properties deteriorate. Further, as a method for producing the prepreg, the reinforcing fiber sheet is impregnated with a matrix resin so as to form at least a continuous resin layer therein, and at least one side of the reinforcing fiber sheet impregnated with the matrix resin. It is known to attach a protective film having an uneven surface to the surface (see, for example, Patent Document 1).

  Further, in the prepreg support sheet for supporting the prepreg in which the reinforcing fiber is impregnated with the thermosetting resin, at least the surface on the side supporting the prepreg has a large number of fine irregularities, and the surface roughness is It is known that it is 8 micrometers or more (for example, refer patent document 2).

  However, in Patent Documents 1 and 2, a rough surface state is maintained until the fiber-reinforced composite material is manufactured, and air is easily removed to eliminate air traps. It is not intended to obtain a fiber reinforced composite material.

  Furthermore, as the bag film 4 in contact with the prepreg laminate, it is known to use a surface processed with irregularities having a depth of 1/2 or less of the film thickness (see, for example, Patent Document 3). ). However, this technique makes the inner side of the bag film 4 slippery and prevents the bag films 4 being vacuum degassed from adhering to each other and the laminated body of 1, 2 and 3, and the surface has a concavo-convex pattern. It is not intended to obtain a reinforced fiber reinforced composite.

JP 2002-327076 A JP 2003-138043 A Japanese Patent Laid-Open No. 6-71763

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is to release embossed release paper for prepreg, and without embossing the machine tool, by molding the fiber reinforced composite material with the release paper with emboss attached. It is to provide an embossed release paper that can shape an embossed pattern by transferring the embossed pattern of the attached release paper onto the surface of a fiber reinforced composite material.

In order to solve the above problems, an embossed release paper according to the present invention is provided on a prepreg obtained by impregnating a reinforcing fiber with an uncured or semi-cured thermosetting resin, and on at least one surface of the prepreg. The release paper of the prepreg laminate having the release paper,
Comprising at least a release layer, a resin layer, and a support,
A release layer, a resin layer, and a support are laminated in order from the prepreg side, and embossing is performed on the release layer surface side of the resin layer.

Moreover, the embossed release paper of another embodiment of the present invention has a prepreg obtained by impregnating a reinforcing fiber with an uncured or semi-cured thermosetting resin, and a release paper on at least one surface of the prepreg. The release paper of the prepreg laminate,
In the release paper, a first release layer, a first resin layer, a first sealing layer, a support, a second sealing layer, and a second resin layer are laminated in order from the prepreg side, and the first The embossed pattern is formed on the release layer surface side of the resin layer.

  An embossed release paper according to a preferred embodiment of the present invention comprises a prepreg obtained by impregnating a reinforcing fiber with an uncured or semi-cured thermosetting resin, and a prepreg laminate having a release paper on at least one surface of the prepreg. The release paper, wherein the release paper is, in order from the prepreg side, a first release layer, a first resin layer, a first sealing layer, a support, a second sealing layer, a second resin layer, and a first Two release layers are laminated, an embossed pattern is formed on the first release layer surface side of the first resin layer, and the release force of the second release layer is the release force of the first release paper. It was made smaller.

  A prepreg laminate which is another embodiment of the present invention is formed by laminating the above-mentioned release paper with emboss on one surface of the prepreg.

Further, the method for producing a fiber-reinforced composite material according to another aspect of the present invention is a method for producing a fiber-reinforced composite material having a surface embossed using a prepreg laminate,
The prepreg laminate is packaged in a bag, and the release paper is peeled from the prepreg laminate after the prepreg laminate is cured by a heating device while keeping the inside of the back packaging in a vacuum. It is characterized by.

Moreover, the method for producing a fiber-reinforced composite material according to another aspect of the present invention is a method for producing a fiber-reinforced composite material whose surface is embossed.
The substrate includes at least a support, a resin layer provided on the support, and a release layer provided on the resin layer, and the surface of the surface of the resin layer on which the release layer is provided is embossed. Prepare release paper with emboss
The release paper and the fiber reinforced composite material are bonded together via a coating resin so that the release layer of the release paper and the fiber reinforced composite material face each other, and heating and drying are performed.
Peeling the release paper from the fiber reinforced composite material, and embossing the surface of the fiber reinforced composite material.

  Moreover, in this invention, the fiber reinforced composite material by which the surface was embossed shape | molded by the manufacturing method of said fiber reinforced composite material is also provided.

  According to the present invention, the prepreg laminate in which the release paper with embossing that has been embossed on the release layer surface side is bonded to at least one surface of the prepreg is cured, and embossing is applied to the surface of the fiber reinforced composite material. Therefore, it is possible to easily and inexpensively emboss the surface of the fiber-reinforced composite material without going through an uneven machining process with a machine tool. That is, the prepreg is cured and molded in a state where the emboss of the release paper with emboss is transferred to the surface of the prepreg before becoming a fiber reinforced composite (before curing). Embossing can be formed on the surface.

  Further, according to the present invention, the fiber reinforced composite material after being cured and molded is bonded to the fiber reinforced composite material and the embossed release paper via a coating resin, and is heated and dried. Embossing can be formed on the surface of the fiber reinforced composite material by peeling the release paper from the reinforced composite material.

  Moreover, according to this invention, various patterns and surface forms can be shape | molded on the surface of a fiber reinforced composite material by changing the embossing pattern of the release paper with embossing. As a result, by appropriately selecting the embossed pattern on the surface, the air resistance on the surface of the fiber reinforced composite material can be reduced or increased, the mechanical strength can be improved, and a sliding effect can be imparted.

  The release paper with embossing according to the present invention can also have a release paper for prepreg. For example, the prepreg 20 can be laminated on the surface of the first release layer 17A of the release paper 10B with emboss, and the other surface can be wound up without a protective film 31 and transported and stored as a long roll. In use, it is easily unwound and the efficiency of workability is good, and since the protective film 31 is not provided, there is an effect that the cost is low.

  Moreover, according to this invention, there exists an effect by which the fiber reinforced composite material by which an embossed pattern is shaped on the surface is obtained by the conventional installation and conditions.

It is sectional drawing which shows one Example of the prepreg laminated body of this invention. It is sectional drawing which shows one Example of the release paper with embossing of this invention. It is sectional drawing which shows one Example of the release paper with embossing of this invention. It is sectional drawing which shows one Example of the riblet pattern formed on a 1st resin layer. It is sectional drawing which shows one Example of the riblet pattern formed on a 1st resin layer. It is sectional drawing which shows one Example of the riblet pattern formed on a 1st resin layer. It is sectional drawing which shows one Example of the riblet pattern formed on a 1st resin layer. It is sectional drawing which shows one Example of the riblet pattern formed on a 1st resin layer. It is a perspective view which shows one Example of the dimple pattern formed on the 1st resin layer.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Single-sided release layer)
As shown in FIG. 2, the embossed release paper 10 of the present invention comprises a prepreg 20 in which a reinforcing fiber 21 is impregnated with an uncured or semi-cured thermosetting resin 22, and at least one surface of the prepreg 20 The release paper 10 of the prepreg laminate 30 having the release paper 10 in the first release layer 17A, the first resin layer 15A, and the first sealing layer 13A in that order from the prepreg 20 side. The support 11, the second sealing layer 13B, and the second resin layer 15B are laminated, and an embossed pattern is formed on the first release layer 17A surface side of the first resin layer 15A. That is, the first release layer 17A / first resin layer 15A (with an embossed pattern) / first sealing layer 13A / support 11 / second sealing layer 13B / second resin layer 15B. This is a single-sided release layer-type embossed release paper 10A.

(Prepreg laminate)
As shown in FIG. 1, a single-sided release layer type release paper 10A with an emboss is laminated on one side of a prepreg 20 to form a prepreg laminate 30, and a protective film 31 or the like is laminated on the other side as necessary. May be. When molding fiber reinforced composite material, the embossed pattern of the embossed release paper is transferred to the surface of the fiber reinforced composite material without going through the uneven processing process with a machine tool. Thus, an embossed pattern can be shaped. Further, even in the case of a prepreg laminate in which release paper having no conventional unevenness is adhered, the single-sided release layer type release paper with embossing of the present invention is applied to the exposed prepreg surface by peeling the release paper. Even if pasted and molded, an embossed pattern can be formed on the surface. In this way, the release paper 10A with emboss not only constitutes the prepreg laminate 30, but also is used in a molding process for forming an emboss pattern on the surface of the fiber reinforced composite material. Call.

  Further, when the release paper 10 with embossing is provided on one surface of the prepreg 20 and the protective film is provided on the other surface, the second sealing layer 13B and / or the second resin layer 15B of the release paper 10 with embossing are provided. First release layer 17A not provided / first resin layer 15A (with embossed pattern) / first sealing layer 13A / support 11 or first release layer 17A / first resin layer 15A (with embossed pattern) / The layer structure of the first sealing layer 13A / support 11 / second sealing layer 13B may be used.

(Double-sided release layer)
Further, as shown in FIG. 3, the embossed release paper 10B of the present invention has a prepreg 20 in which a reinforcing fiber 21 is impregnated with an uncured or semi-cured thermosetting resin 22, and at least one of the prepreg 20 The release paper 10 of the prepreg laminate 30 having the release paper 10 on its surface, the release paper 10 being in order from the prepreg 20 side, the first release layer 17A, the first resin layer 15A, the first eye stop The layer 13A, the support 11, the second sealing layer 13B, the second resin layer 15B, and the second release layer 17B are laminated, and the first release layer 17A surface side of the first resin layer 15A An embossed pattern is formed on the surface, and the peeling force of the second release layer 17B is smaller than the peeling force of the first release layer 17A. The peeling force of the first release layer> the peeling of the second release layer Power. That is, first release layer 17A / first resin layer 15A (with embossed pattern) / first sealing layer 13A / support 11 / second sealing layer 13B / second resin layer 15B / second release layer 17B This is a double-sided release layer type release paper 10B with embossing.

(Prepreg laminate)
If the double-sided release layer type release paper 10B with emboss is laminated on one surface of the prepreg 20, a prepreg laminate 30 is obtained. The prepreg 20 is laminated on the surface of the first release layer 17A of the double-sided release layer type embossed release paper 10B, and the other side is wound up without the protective film 31 and transported and stored as a long roll. You can also. That is, since the surface of the prepreg 20 and the second release layer 17B, which are lightly peeled, come into contact with each other, even after unwinding in use, the prepreg 20 peels off from the second release layer 17B, and the prepreg 20 Since 20 are laminated, the efficiency of the subsequent workability is good. If there is no difference in peeling between the front and back of the release paper, it will not wind up properly and the epoxy resin will be taken on the back side. Therefore, a difference in peel strength is required. Moreover, since there is no protective film 31, it is also low-cost.

  The first release layer 17A and the second release layer 17B are collectively referred to as the release layer 17, and the first resin layer 15A and the second resin layer 15B are collectively referred to as the resin layer 15. The first sealing layer 13A and the second sealing layer 13B are collectively referred to as the sealing layer 13. Further, the gist of the embossed release paper of the present invention is the layer configuration of the first release layer 17A / first resin layer 15A (with embossed pattern) / first sealing layer 13A / support 11, and the first The resin layers 15A have embossed release papers 10A and 10B, and other layers may be formed on the interlayer or the front and back surfaces of the layers.

(Support)
The support 11 has a strength that can withstand the manufacturing process, has properties such as heat resistance and chemical resistance as the release paper 10 of the resin layer 15, and withstands an embossing process in which an embossed pattern is formed on the surface. The embossing needs to be easy. As the support, non-coated paper such as kraft paper, high-quality paper, glossy kraft paper, pure white roll paper, glassine paper, and cup base paper, as well as synthetic paper that does not use natural pulp can be used. For processing suitability, it is preferable to use paper made of natural pulp from the viewpoint of excellent durability and heat resistance. Also, use commercially available products with a sealing layer or resin layer described later, such as general fine coated printing paper, coated printing paper, resin-coated paper, processed base paper, release base paper, double-sided coat base paper, etc. You can also

The paper 11 used as the support has a weight of about 15 to 300 g / m ² , preferably 100 to 180 g / m ² . If it is this range, embossing will be easy. The paper is preferably neutral paper. When acid paper containing a sulfuric acid band or the like is repeatedly used in the production process, thermal degradation occurs, and it may be difficult to reuse the paper at an early stage. If it is a neutral paper, such thermal deterioration can be prevented.

  Further, neutral rosin, alkyl ketene dimer, alkenyl succinic anhydride may be used as a sizing agent, and cationic polyacrylamide, cationic starch, or the like may be used as a fixing agent. Moreover, although it is most preferable not to use a sulfuric acid band for the said reason, it is also possible to make paper in a neutral region of pH 6-9 using a sulfuric acid band. In addition to the above sizing agents, as well as fixing agents, various papermaking fillers, yield improvers, dry paper strength enhancers, wet paper strength enhancers, binders, dispersants, flocculants, plastics An agent and an adhesive may be appropriately contained.

  In addition, for example, general commercially available fine-coated printing paper, coated printing paper, resin-coated paper, processed base paper, release base paper, double-sided coat base paper, etc. It can also be used. When using a commercial product on which a sealing layer is formed, the sealing layer 13 may be omitted.

(Sealing layer)
When the sealing layer 13 is formed, the coating material used for the resin layer 15 can be prevented from penetrating, and the adhesion to the coating material can be improved to provide smoothness. It can be suitably used as a mold sheet. The first sealing layer 13A and the second sealing layer 13B may be the same or different. In summary, the sealing layer 13 will be described.

  As the sealing layer 13, it consists of what contained 0.5-50 mass% of inorganic pigments with respect to resin which has film forming property. Examples of the resin having a film-forming property include polyvinyl alcohol, acrylic resin, styrene acrylic resin, cellulose derivative, polyester resin, polyurethane resin, melamine resin, alkyd resin, aminoalkyd resin, polyvinyl chloride resin, polyvinylidene chloride resin, and synthetic latex. , Natural rubber, polybutadiene, styrene-butadiene polymer, acrylonitrile-butadiene polymer, methyl methacrylate-butadiene polymer, 2-vinylpyridine-styrene-butadiene polymer, polychloroprene, polyisoprene, polystyrene, polyurethane Acrylate polymer, polyvinyl acetate, vinyl acetate copolymer, vinyl acetate-ethylene copolymer, acrylate-styrene polymer, polyethylene, vinyl chloride polymer, vinylidene chloride Polymers, such as epoxy-containing resin can be suitably used. You may use these in mixture of 2 or more types.

Examples of the inorganic pigment include talc, kaolin, silica, calcium carbonate, barium sulfate, titanium oxide, and zinc oxide, and 0.5 to 70% by mass is blended with respect to the resin having the film forming property. If the amount is less than 0.5% by mass, the sealing effect may be reduced. On the other hand, if it exceeds 70% by mass, the embossing property may be inhibited. 0.5 to 20 g / m ² is preferably sufficient for the sealing layer. The sealing material can be applied by a known coating method such as a comma coater. The coating of the sealing material is usually diluted with 10 to 1000 parts by mass of solvent with respect to 100 parts by mass of the solid content. By diluting the solvent, an appropriate viscosity for coating, for example, a viscosity of 10 to 3000 mPa · sec at 25 ° C. can be imparted.

(Resin layer)
The first resin layer 15A and the second resin layer 15B may be the same or different, and will be collectively described as the resin layer 15.

  Since the embossed pattern is formed on the surface by molding the fiber reinforced composite material from the prepreg 20 while the release paper 10 with the emboss is attached at the time of molding, the resin layer has an embossed structure at the time of embossing. Need to maintain. Since embossing is generally performed at a temperature of 40 to 150 ° C., the resin is excellent in solvent resistance, is not excessively softened during embossing, has excellent moldability, is easy to wind up the raw material, and is extremely easy to operate. In addition, it is preferable to use a material that is excellent in tackiness and that is tack-free (also referred to as a finger dry state) when the resin layer is formed.

  The resin layer may be a single layer or a multilayer, and is made of a colorless or colored transparent or translucent resin, which is tack-free at the time of forming the resin layer, and the embossed pattern can be reproduced by embossing. Any resin may be used. For example, a thermoplastic resin such as polypropylene, polyethylene, or polymethylpentene, or an ionizing radiation curable resin such as an acrylate resin can be used. In addition, as a curing method of the ionizing radiation curable resin composition, the curing method of the ionizing radiation curable resin composition can be cured by an ordinary curing method, that is, irradiation with an electron beam or ultraviolet rays. As these ultraviolet curable resins, for example, epoxy-modified acrylate resins, urethane-modified acrylate resins, acrylic-modified polyesters and the like can be applied, and urethane-modified acrylate resins are preferable.

  As a preferable resin composition, a resin composition comprising the (meth) acryloyl group-containing acrylic copolymer (1), or 35 to 80 parts by mass of (meth) acrylate ester, 20 to 60 glycidyl (meth) acrylate ester. (Meth) acryloyl group-containing acrylic copolymer obtained by reacting 10 to 30 parts by mass of (meth) acrylic acid with a copolymer consisting of 0 to 30 parts by mass of another (meth) acrylic acid ester ( The resin composition comprising 2) is cured by ultraviolet rays, and the (meth) acryloyl group-containing acrylic copolymer (1) has a weight average molecular weight (Mw) of 5,000 to 200,000. Preferably it is 15,000-100,000, Most preferably, it is 15,000-70,000. The dispersion ratio (Mw / Mn) of the (meth) acryloyl group-containing acrylic copolymer (1) is 1.0 to 5.0, more preferably 1.5 to 4.0, and particularly preferably 1.9. The glass transition temperature (Tg) is 40 to 150 ° C, more preferably 65 to 120 ° C, and particularly preferably 65 to 90 ° C. In addition, a weight average molecular weight and a number average molecular weight are the values calculated | required in polystyrene conversion by the gel permeation chromatography (GPC) method.

  As such a (meth) acryloyl group-containing acrylic copolymer (1), for example, a (meth) acrylate monomer unit (A) and an epoxy group-containing (meth) acrylate monomer unit (B) The epoxy group-containing copolymer (C) containing can be obtained by reacting (meth) acrylic acid. As the (meth) acrylate monomer unit (A), methyl methacrylate, methyl acrylate, butyl acrylate, butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, hydroxyethyl acrylate, hydroxyethyl methacrylate, isobornyl acrylate, isobornyl methacrylate , Cyclohexyl acrylate, cyclohexyl methacrylate, etc., preferably methyl methacrylate, methyl acrylate, isobornyl methacrylate, isobornyl acrylate and the like. Examples of the epoxy group-containing (meth) acrylate monomer unit (B) include glycidyl methacrylate, methyl glycidyl methacrylate, 3,4-epoxycyclohexylmethyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, and aziridinyl (meth) acrylate. is there.

  The compounding ratio of the (meth) acrylate monomer unit (A) and the epoxy group-containing (meth) acrylate monomer unit (B) is the above epoxy group-containing (meth) in the total mass of the monomer units. It is to mix the acrylate monomer unit (B) so as to be 5 to 95% by mass. When the amount is less than 5% by mass, a sufficient double bond equivalent cannot be secured, and the solvent resistance and scratch resistance after curing of the (meth) acryloyl group-containing acrylic copolymer (1) are impaired. There is. On the other hand, if it exceeds 95% by mass, the tackiness of the uncured film due to the Tg being too low may occur, and the moldability may be impaired. The reaction is obtained by copolymerizing the above monomer units in the presence of a radical initiator.

  The resin composition is a copolymer composed of 35 to 80 parts by mass of (meth) acrylic acid ester, 20 to 60 parts by mass of glycidyl (meth) acrylic acid ester, and 0 to 30 parts by mass of other (meth) acrylic acid ester. It may be a (meth) acryloyl group-containing acrylic copolymer (2) obtained by reacting 10 to 30 parts by mass of (meth) acrylic acid. (Meth) acrylates and other (meth) acrylates correspond to the above (meth) acrylate monomer units (A), and glycidyl (meth) acrylates are epoxy group-containing (meth) acrylates. It corresponds to the monomer unit (B). Therefore, other (meth) acrylic acid esters can be appropriately selected from the above (meth) acrylate monomer units (A).

  The resin composition may be composed only of the (meth) acryloyl group-containing acrylic copolymers (1) and (2). The composition is a mixture of two or more kinds of substances, but as is apparent from the dispersion ratio of the (meth) acryloyl group-containing acrylic copolymer (1), it contains (meth) acryloyl group having different molecular weights. Since an acrylic copolymer is included, the present application also refers to a resin composition when it is composed only of a (meth) acryloyl group-containing acrylic copolymer. On the other hand, the resin composition used in the present invention may further contain an inorganic pigment, a photopolymerization initiator, and the like. A matte feeling can be imparted to the embossed release paper by blending the inorganic pigment. Examples of such inorganic pigments include talc, kaolin, silica, calcium carbonate, barium sulfate, titanium oxide, and zinc oxide. The inorganic pigment is preferably blended in the film in an amount of 0.5 to 50% by mass, more preferably 1 to 10% by mass. When the resin layer is composed of two or more layers, the blending amount of the inorganic pigment in each layer is within the above range.

  As the coating method, known as direct gravure coat, reverse gravure coat, gravure offset coat, micro gravure coat, direct roll coat, reverse roll coat, curtain coat, knife coat, air knife coat, bar coat, die coat, spray coat, etc. The method is used. After coating, the resin composition is dried and heated at a temperature of 90 to 130 ° C., and the solvent is evaporated in a drying furnace to dry the resin composition. This temperature is in a range higher than the softening point of the resin composition and lower than the temperature at which the resin composition melts.

  The thickness of the resin layer is preferably 1 to 50 μm, more preferably 3 to 20 μm. If it is thinner than 1 μm, the transfer of fine moldability is worsened, while if it exceeds 50 μm, the curability of the resin may be worsened. As described above, when the resin layer is composed of two or more layers, the thickness of all the layers is set in the above range. Specifically, LP-07K (manufactured by Toa Gosei Co., Ltd., resin product name), MHX405 varnish (manufactured by DIC Graphics, Inc., resin product name), Iupimer LZ650 (manufactured by Mitsubishi Chemical Co., Ltd., resin product name), Examples include Iupimer UV V3031 (manufactured by Mitsubishi Chemical Corporation, resin name).

(Other middle layer)
In the present invention, an intermediate layer may be formed between the resin layer and the support. An intermediate | middle layer is arrange | positioned in order to ensure heat resistance, a moldability, peelability, solvent resistance, and a sealing effect, and is a thermoplastic resin layer or a sealing layer.

(Shaping)
In order to emboss the first release layer 17A surface side of the first resin layer 15A, it is heated and pressed with an embossing roll having a desired surface form using a known embossing machine, and then embossed and peeled off from the embossing roll. Thereafter, the resin layer subjected to embossing can be formed by irradiating and curing ionizing radiation immediately or later. Embossing can be made into various surface forms depending on the use of the fiber reinforced composite material obtained by using the release paper. For example, it can be a concavo-convex pattern, a dimple pattern, a prism pattern, or a fiber pattern, or it can be a matte tone by providing fine irregularities on the surface, or a glossy surface.

  Hereinafter, a case where an embossed pattern is shaped on the surface of the first resin layer 15A will be described as an example. The embossed pattern was formed by forming the embossed pattern with a known embossing machine after applying the resin composition described above on the support 11 (or the sealing layer 13) in the first resin layer 15A forming step. The first resin layer 15A having an embossed pattern is formed by heating and pressurizing and embossing using an embossing roll, and curing by irradiating with ionizing radiation immediately after or after peeling from the embossing roll. As a light source for ionizing radiation, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, a xenon lamp, a tungsten lamp, or the like is used. The embossed pattern may be shaped after the first release layer 17A is provided. The embossed pattern is not particularly limited. In addition to the concavo-convex patterns described above, for example, leather patterns such as grain, satin, tanned skin, mesh, snake skin, cows and deer, hairlines, lines, fiber texture patterns, large and small protruding dimples, prisms (riblet structure) ), Patterns such as opal can be applied, and may be appropriately selected depending on the intended use. Further, the concavo-convex pattern may be convex, concave, or a mixed type thereof. The convex height and / or concave depth is not particularly limited, and is preferably about 0.001 to 5 mm, for example, and 0.1 to 1.0 mm for ease of shaping.

  As shown in FIG. 4, the riblet structure formed on the surface of the first resin layer 15 </ b> A has a cross-sectional shape having a streak-like uneven shape in the sheet longitudinal direction and a plurality of protrusions 18 in the sheet width direction. It can be illustrated. The shape of the convex portion may be a substantially rectangular cross section as shown in FIG. 4, a substantially triangular cross section as shown in FIG. 5, or a substantially trapezoidal cross section as shown in FIG. It may be. In addition to the cross-sectional shape shown in FIGS. 5 and 6, the shape of the convex portion may be a cross-sectional shape as shown in FIGS. 7 and 8 in which a flat portion exists in the concave portion.

When the streaky uneven shape on the surface of the first resin layer 15A has a substantially rectangular cross section shown in FIG. 4, the width W _U of one rectangular cross section is preferably 0.1 μm to 200 mm, and preferably 20 μm to 5 mm. More preferably. Moreover, it is preferable that the height H of a convex part is 0.1 micrometer-100 mm, More preferably, it is 3 micrometers-500 micrometers. Moreover, it is preferable that it is 0.1 micrometer-500 mm, and, as for the width W _L of the bottom of a recessed part, it is more preferable that it is 20 micrometers-5 mm.

  When the streaky unevenness on the surface of the first resin layer 15A has a substantially triangular cross section shown in FIG. 5, the length of the base T of the triangle is preferably 0.1 μm to 500 mm, and preferably 20 μm to 5 mm. It is more preferable. Further, the height H of the triangle is preferably 0.1 μm to 100 mm, more preferably 3 μm to 500 μm.

Streaky irregularities of the first resin layer 15A surface if it has a substantially trapezoidal cross-section shown in FIG. 6, the length _{T U} of the trapezoidal upper side is preferably 0.01Myuemu～100mm, in 1μm~5mm More preferably. Further, the length _Td of the lower side of the trapezoid is preferably 0.1 μm to 200 mm, and more preferably 20 μm to 5 mm. Further, the height H of the substantially trapezoid is preferably 0.1 μm to 100 mm, more preferably 3 μm to 500 μm.

When the streaky unevenness on the surface of the first resin layer 15A has a substantially triangular cross section shown in FIG. 7, the length of the base T of the triangle is preferably 0.01 μm to 100 mm, and preferably 1 μm to 5 mm. It is more preferable. Further, the height H of the triangle is preferably 0.1 μm to 100 mm, more preferably 3 μm to 500 μm. Moreover, it is preferable that it is 0.1 micrometer-200 mm, and, as for the width W _L of the bottom of a recessed part, it is more preferable that it is 20 micrometers-5 mm.

Streaky irregularities of the first resin layer 15A surface if it has a substantially trapezoidal cross-section shown in FIG. 8, the length _{T U} of the trapezoidal upper side is preferably 0.01Myuemu～100mm, in 1μm~5mm More preferably. Further, the length T _L of the lower side of the trapezoid is preferably 0.1 μm to 200 mm, and more preferably 20 μm to 5 mm. Further, the height H of the substantially trapezoid is preferably 0.1 μm to 100 mm, more preferably 3 μm to 500 mm. In addition, the width W _L of the bottom of the recess is preferably 0.01 μm to 100 mm, and more preferably 1 μm to 5 mm.

  Further, in the present invention, the streaky uneven shape 18 on the surface of the first resin layer 15A may be a shape in which the convex portion and the concave portion shown in FIGS. 4-8, the flat part (for example, the upper side part of a convex part, the lower side part of a recessed part, etc.) does not need to be substantially flat, and may be a curved surface, and FIG. In the substantially rectangular shape, the substantially triangular shape, and the substantially trapezoidal cross section as shown in ˜8, the apex (corner portion) may be rounded.

Further, the surface of the resin layer 15 may be provided with a dimple shape 19 in addition to the above-described streaky uneven shape 18. The dimple shape can be a hemispherical convex shape as shown in FIG. The hemispherical dimples are preferably 1 × 10 ⁻⁴ to 1 × 10 ⁸ pieces / mm ² , more preferably 1 × 10 ⁻² to 1 × 10 ³ pieces / mm ² . Further, the ratio of the area of the dimples to the entire surface is in the range of 1 to 100%. The height of the hemispherical convex dimple (the distance between the surface of the resin layer 15 and the top of the hemispherical convex dimple) is about 50 nm to 10 mm, preferably 50 nm to 300 μm.

  The hemispherical convex dimples need not all have the same size, but may be a combination of two or more hemispherical convex dimples having different sizes. For example, it may be an uneven shape in which two hemispherical dimples of different sizes are arranged alternately. In this case, two hemispherical dimples of different sizes are alternately arranged so that the angle between the line connecting the centers of the dimples to be rubbed and the line connecting the centers of the other adjacent dimples is 60 °. It is preferable to do.

  In the present invention, the concavo-convex shape may be a concavo-convex shape made of a hemispherical concave dimple in addition to the above-described hemispherical convex dimple. In this case, the number of dimples and the size of the dimple are the case of a hemispherical convex dimple. It is the same. In the case of a hemispherical concave dimple, the depth of the dimple (the distance between the surface of the resin layer 15 and the bottom of the hemispherical concave dimple) is about 50 nm to 10 mm, preferably 50 nm to 300 μm.

  In addition to the convex shape of the hemisphere (or the concave shape of the hemisphere), the dimple has the shape of a cone (inverted cone), a polygonal pyramid (inverted polygonal pyramid), a truncated cone (inverted truncated cone), and a polygonal frustum (inverted polygonal truncated cone). It may be. When the dimples have these shapes, the number of dimples and the size of the dimples may be the same as in the case of a hemispherical convex dimple. When the shape is a cone (inverted cone), polygonal pyramid (inverted polygonal pyramid), truncated cone (inverted truncated cone), or polygonal truncated cone (inverted polygonal truncated cone), its height (depth) is about 100 nm to 100 mm. And preferably 3 μm to 500 μm.

(Release layer)
The first release layer 17A and the second release layer 17B may be the same or different, and will be collectively described as the release layer 17. The release layer 17 is obtained by curing a curable silicone composition. The curability includes an addition polymerization type and a condensation reaction type. Preferably, the addition polymerization type silicone composition is cured by heat or the like. Condensation-type silicone resins are less susceptible to cure inhibition, but are undesirable because by-products are formed and tin is used as a catalyst. Addition-polymerization silicone resins are susceptible to cure inhibition by amines and tin, but by-products There is no thing and the pot life is long and preferable.

  As a preferable curable silicone resin, a curable silicone composition comprising an alkenyl group-containing organopolysiloxane, an organohydrogenpolysiloxane and a platinum-based curing catalyst is cured. Commercially available products may be used as the curable silicone composition. For example, the main component of an addition polymerization type silicone material (mixed with Shin-Etsu Chemical Co., Ltd.) made of a mixture of an alkenyl group-containing organopolysiloxane and an organohydrogenpolysiloxane. KS-3603) can be prepared by mixing a curing agent comprising a platinum-based curing catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT-PL-50T).

  The mold release layer 17 is formed by a known coating such as gravure coating, roll coating, reverse roll coating, spray coating, etc. by diluting the curable silicone composition with a solvent, if necessary, or heating to a liquid state. What is necessary is just to apply | coat and dry by the method, and also to heat-age and harden | cure. The thickness of the release layer 17 is preferably in the range of 0.01 to 10 μm. While fixing the embossed pattern formed by embossing, it requires curability to obtain sufficient film properties such as surface strength.

(Peeling force difference)
In the embossed release paper 10B having the double-sided release layer shown in FIG. 3, the release force of the second release layer 17B is made smaller than the release force of the first release layer 17A. As for the difference in peel force, when silicone resins having different peel forces are used, or when the same silicone resin is used, a peel control agent for increasing or reducing the peel force may be added as appropriate.

(Prepreg, reinforcing fiber)
The prepreg 20 is obtained by impregnating reinforcing fibers 21 with an uncured or semi-cured thermosetting resin 22. Although it does not specifically limit as the reinforced fiber 21, For example, carbon fiber, glass fiber, an aramid fiber, boron fiber, steel fiber etc. can be used. Among these, carbon fibers are widely used because of their good mechanical properties after molding. Examples of the carbon fiber include polyacrylonitrile (PAN) type carbon fiber and pitch type carbon fiber. Further, the form and arrangement of the reinforcing fibers are not particularly limited, and there are a sheet in which long fibers are aligned in one direction, a cloth (woven fabric), a tow, a mat, a knit, and a sleeve.

(Thermosetting resin)
The thermosetting resin is not particularly limited, and examples thereof include an epoxy resin, a polyester resin, a vinyl ester resin, a phenol resin, a maleimide resin, a polyimide resin, and a BT resin, and an epoxy resin is preferable. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, fluorene type epoxy resin, or a combination thereof. Resins etc. are preferably used. Further, a polyfunctional epoxy resin having three or more functions may be used. For example, a phenol novolac type epoxy resin, a cresol type epoxy resin, a glycidylamine type epoxy resin such as tetraglycidyldiaminodiphenylmethane, triglycidylaminophenol, tetraglycidylamine, tetrakis ( A glycidyl ether type epoxy resin such as glycidyloxyphenyl) ethane or tris (glycidyloxymethane), or a combination thereof is preferably used.

  The thermosetting resin has an effect on the performance and does not affect the performance. Additives such as a curing agent, thermoplastic resin, rubber particles, soluble rubber, core shell rubber, etc. for the purpose of control of resin viscosity and prepreg handling. May be blended. Curing agents include aromatic amines such as diphenylmethane and diaminodiphenylsulfone, aliphatic amines, imidazole derivatives, dicyandiamide, tetramethylguanidine, thiourea addition amines, carboxylic acid anhydrides such as methylhexahydrophthalic anhydride, It is preferable to add a curing agent such as a carboxylic acid hydrazide, a carboxylic acid amide, a polyphenol compound, a novolac resin, a polymercaptan, a Lewis acid complex such as boron trifluoride ethylamine complex.

(Manufacture of prepreg laminate)
The release paper 10 with emboss is laminated on one surface of the prepreg 20 in which the reinforcing fiber 21 is impregnated with the uncured or semi-cured thermosetting resin 22, and a protective film 31 or the like is laminated on the other surface as necessary. By stacking, the prepreg laminate 30 is obtained.

  Although the manufacturing method of the prepreg laminate 30 is not particularly limited, for example, the thermosetting resin 22 serving as a matrix resin is uniformly applied to the surface of the first release layer 17A of the release paper 10 with emboss, It is preferable that a reinforcing fiber sheet is attached to the resin surface to impregnate the resin, and a protective film is attached to the other surface.

  Although it does not specifically limit about a protective film, What is necessary is just to select suitably according to the adhesiveness with matrix resin, and the kind of matrix resin, for example, the polyolefin-type films, such as polyethylene currently used conventionally, It can be illustrated.

  As another manufacturing method of the prepreg laminate 30, a matrix resin is uniformly applied to the surface of the first release layer 17A of a pair of embossed release papers 10, and the release layer surface of another set of conventional release papers. Alternatively, the matrix resin may be uniformly applied, and the two sets may be sandwiched from both sides of the reinforcing fiber sheet, and the reinforcing fiber sheet may be impregnated with the resin. The prepreg laminate 30 obtained by this method is preferable because the resin is uniformly impregnated throughout the prepreg.

  In addition, the matrix resin is uniformly applied to the release layer surface of the two sets of conventional release paper, sandwiched from both sides of the reinforcing fiber sheet with these two sets, and the reinforcing fiber sheet is impregnated with the resin, and then one of the release papers The release paper 10A with emboss may be laminated instead. Moreover, the other release paper may be peeled off and a protective film may be attached instead.

(Fiber-reinforced composite material manufacturing method)
Using the prepreg laminate 30 shown in FIG. 1 described above, a fiber-reinforced composite material having an embossed pattern on its surface is manufactured. In the prepreg laminate 30, (1) a single-sided release layer type release paper 10A with embossing shown in FIG. 2 is laminated on one surface of the prepreg 20, and a protective film 31 is laminated on the other surface as necessary. There are two types: (1) a double-sided release layer type release paper 10B with embossing shown in FIG. In any type, the embossed pattern of the embossed release papers 10A and 10B can be obtained without molding the uneven process by a machine tool by molding the fiber reinforced composite material with the embossed release papers 10A and 10B attached. An embossed pattern can be formed by transferring to the surface of the fiber reinforced composite material. Further, in the case of a prepreg laminate in which a release paper having no conventional unevenness is adhered, the single-sided release layer type release paper 10A with embossing of the present invention is applied to the exposed prepreg surface by peeling the release paper. Even if it sticks and shape | molds, an embossed pattern can be shaped on the surface.

  Specifically, the release paper 10 with emboss may be laminated with an autoclave bag, packaged in an autoclave bag, kept in a vacuum in the auto back packaging and thermally cured by an autoclave device, and then the release paper 10 with emboss may be peeled off. . The embossed release paper 10 also serves as a prepreg release paper and can be molded with the embossed release paper affixed at the time of molding the fiber reinforced composite material. is there. Moreover, the autoclave bag and the autoclave apparatus are also low in cost in that a conventional existing one can be used.

  Further, in the present invention, as described above, even if emboss molding is performed on the surface of the fiber-reinforced composite material, the prepreg laminate in which the prepreg and the release paper are laminated is heat-cured and the release paper is peeled off. However, after the prepreg is heat-cured to obtain a fiber-reinforced composite material, embossing can be performed on the surface thereof. Specifically, the substrate includes at least a support, a resin layer provided on the support, and a release layer provided on the resin layer, and the surface of the resin layer on which the release layer is provided. A release paper with embossing whose surface is embossed is prepared, and the release paper and the fiber reinforced composite material are interposed via a coating resin so that the release layer of the release paper and the fiber reinforced composite material face each other. Are bonded to each other, heated and dried, and the release paper is peeled off from the fiber reinforced composite material to emboss the surface of the fiber reinforced composite material.

(Fiber reinforced composite)
The fiber reinforced composite material produced by the method for producing a fiber reinforced composite material using the prepreg laminate 30 supported by the release papers 10A and 10B with embossing and having an embossed pattern on the surface is as follows. Can produce various effects. (1) By using a fiber-reinforced composite material obtained by shaping the embossed pattern on the surface in a scale or crushed skin shape on a surface member of a moving body such as an automobile or a ship, air resistance is reduced and fuel efficiency is improved. (2) Since an embossed pattern can be formed on the surface, the mechanical strength is improved. (3) Conversely, if the embossed pattern is shaped to increase the air resistance, the air resistance is increased as a surface member of the windmill wing, that is, the power generation efficiency is improved. (4) Depending on the embossed pattern, the fiber reinforced composite material (part) can be slid.

  In addition to the wind turbine blades described above, for example, a mixed pipe or pipeline is formed of a fiber reinforced composite, and the inner wall of the pipe is embossed. It can be made into the form. A pipe made of such a fiber-reinforced composite not only has excellent mechanical strength of the pipe, but also can reduce the resistance between the gas or liquid flowing in the pipe and the inner wall surface of the pipe. Particularly preferred. In addition, automobile bodies and wheels, hulls, storage cases, surfboards, lures (pseudo bait), jet balances, airplanes, rockets, missiles, space stations, bicycle tire wheels, bicycle housings, helmets, trains (pantographs and heads) Part), goggles, ski board, snowboard, luge board, canoe, canoe all, propeller, rice paddle, golf head, shaft, high-rise building, camera tripod, blowing arrow, OA equipment, stationery, etc. it can.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this. In addition, except a solvent, each composition of each layer is a mass part of solid content conversion.

Example 1
<Preparation of release paper with emboss>
High-quality paper (basis weight 104.5 g / m ² ) was used as the paper 11, and the sealing coating material (60 parts kaolin clay, 10 parts titanium oxide, 30 parts calcium carbonate, 17 parts SBR latex, and other dispersant 0 on both sides .5 parts and 1 part of a lubricant slurry) were coated with a blade coater so that each layer after drying was 16 g / m ² ) and dried to form a first sealing layer 13A and a second sealing layer 13B. Formed.

  The double-sided coated paper comprising the first sealing layer 13A / paper 11 / second sealing layer 13B was flattened by calendaring with a super calendar machine.

LP-07K (manufactured by Toa Gosei Co., Ltd., resin product name) is appropriately diluted with a solvent on each surface of the first sealing layer 13A and the second sealing layer 13B, and each layer after drying with a gravure coater is 4 g / coated and dried so as to m ^2, and forming the first resin layer 15A and the second resin layer 15B in the uncured state.

To the surface of the first resin layer 15A, 100 parts of silicone resin (x-62-3603 manufactured by Shin-Etsu Chemical Co., Ltd.) and 40 parts of release control agent (KS-3800 manufactured by Shin-Etsu Chemical Co., Ltd.) are diluted appropriately with a solvent. Then, each layer after drying with a gravure coater was coated so as to be 0.3 g / m ² and dried to form the first release layer 17A.

To the second resin layer 15B surface, 100 parts of silicone resin (x-62-3603 manufactured by Shin-Etsu Chemical Co., Ltd.) is appropriately diluted with a solvent, and each layer after drying with a gravure coater becomes 0.3 g / m ^2. Coating and drying were performed to form the second release layer 17B, and release paper was obtained.

<Shaping the embossed pattern>
A dimple pattern (a conical shape with a bottom diameter of 1 mm and a height of 0.1 mm is aligned on a surface with a vertical and horizontal pitch of 2.0 mm) is formed on the surface of the first release layer 17A of the release paper produced as described above. In the embossing machine having the embossing roll, after passing through a hot embossing roll heated to 120 ° C., UV light of 700 mJ was irradiated on both sides with a high-pressure mercury lamp, and the dimple pattern became concave. An embossed release paper 10 was obtained.

<Processing into fiber-reinforced composite materials (parts)>
The embossed release paper 10 with dimple processing produced above is overlaid so that the dimples are in contact with the surface of a prepreg (manufactured by Toray Industries, Inc., P2302 (carbon fiber basis weight 190 g / m ² , resin basis weight 35 g / m ² )). And an autoclave bag (Lightcast 7500R manufactured by Airtech Co., Ltd., nylon, thickness 80 μm)). Thereafter, the inside of the bag was kept in a vacuum, and was heated and cured by an autoclave device at 120 ° C. for 4 hours to obtain a fiber reinforced composite material (part). Thereafter, the release paper 10 with an emboss was peeled to form convex dimples on the surface of the CFRP (fiber reinforced composite material).

(Example 2)
An embossed release paper 10 of Example 2 was obtained in the same manner as in Example 1 except that the embossed pattern was a 1K plain weave fabric pattern having a depth of about 0.1 mm.

(Example 3)
Embossed release paper of Example 3 in which the dimple pattern is concave, as in Example 1, except that the second sealing layer 13B, the second resin layer 15B, and the second release layer 17B are not formed. 10 was obtained.

Example 4
A 250 ° F. curable epoxy resin is applied to the dimple surface of the embossed release paper 10 of Example 1, and a 250 ° F. curable epoxy resin is separately applied to the release layer surface of the conventional release paper. A release paper was prepared.

Using these two release papers, the production conditions are set so that the tensile strength is 4410 MPa, the elastic modulus is 235 GPa, and the carbon fiber of 12000 filaments, and the fiber basis weight is 150 g / m ² and the resin content is 35% by mass. The prepreg laminate 30 was manufactured.

  After this prepreg laminate 30 is cured by the same autoclave method as in Example 1, the dimples are shaped on the CFRP (fiber reinforced composite) surface by peeling off the embossed release paper 10 of Example 1. A fiber reinforced composite material (part) was obtained.

(Example 5)
A fiber-reinforced composite material (part) having a plain weave pattern formed on the surface of Example 5 was obtained in the same manner as Example 4 except that the release paper 10 with embossing of Example 2 was used.

A prepreg (manufactured by Toray Industries, Inc., P2302 (carbon fiber basis weight 190 g / m ² , resin basis weight 35 g / m ² )) is overlaid on the dimple surface of the embossed release paper 10 of Example 3, and an autoclave bag (manufactured by Airtech). Light cast 7500R, nylon, thickness 80 μm)). Thereafter, the inside of the bag was kept in a vacuum, and was heated and cured by an autoclave device at 120 ° C. for 4 hours to obtain a fiber reinforced composite material (part). Thereafter, the release paper 10 with an emboss was peeled to form convex dimples on the surface of the CFRP (fiber reinforced composite material).

(Comparative Example 1)
After CFRP molding by a known method, a dimple pattern similar to that of Example 1 was processed on the surface by a precision processing molding machine. As a result, it took 24 hours, and further cleaning work was required, which was not practical. In Example 1, since the dimple pattern was formed simultaneously with the processing to the fiber reinforced composite material (part), it did not take time and no cleaning work was required.

  Using the release paper 10 with embossing of the present invention, a fiber-reinforced composite material made of a reinforcing fiber and a thermosetting resin is used for sports leisure such as fishing rods and golf shafts, for space and aircraft, automobiles and ships. It can be used for general industrial purposes such as transportation and construction. However, it is not particularly limited as long as it is lightweight and requires good mechanical properties such as mechanical strength and elastic modulus. For example, a storage case, a surfboard, a lure (pseudo bait), a jet balance, Bicycle tire wheel, bicycle housing, helmet, train (pantograph and head), goggles, ski board, snowboard, luge board, canoe, canoe all, propeller, rice paddle, high-rise building, camera tripod, blow arrow, OA equipment, stationery Etc., etc.

10: Release paper with emboss 10A: Release paper with emboss (single-sided release)
10B: Release paper with emboss (double-sided release)
11: Support 13: Sealing layer 13A: First sealing layer 13B: Second sealing layer 15: Resin layer 15A: First resin layer 15B: Second resin layer 17: Release layer 17A: First release layer Layer 17B: Second release layer 18: Riblet pattern (shaped pattern)
19: Dimple pattern (shaped pattern)
20: Prepreg 30: Prepreg laminate

Claims (10)

A prepreg obtained by impregnating a reinforcing fiber with an uncured or semi-cured thermosetting resin, and a release paper provided on at least one surface of the prepreg, the release paper of the prepreg laminate,
Comprising at least a release layer, a resin layer, and a support,
A release paper with embossing, wherein a release layer, a resin layer, and a support are laminated in order from the prepreg side, and embossing is applied to the release layer surface side of the resin layer.   The release paper with embossing according to claim 1, wherein a sealing layer is provided between the resin layer and the support.   The first release layer, the first resin layer, the first sealing layer, the support, the second sealing layer, and the second resin layer are laminated in order from the prepreg side. Release paper with emboss.   The release paper with embossing according to claim 3, wherein the release force of the second release layer is smaller than the release force of the first release layer.   The release paper with embossing as described in any one of Claims 1-4 whose said embossing is a concavo-convex pattern, a dimple pattern, a prism pattern, or a fiber pattern pattern.   A prepreg laminate, wherein the release paper with embossing according to any one of claims 1 to 5 is laminated on one surface of the prepreg. A method for producing a fiber-reinforced composite material whose surface is embossed using the prepreg laminate according to claim 6,
The prepreg laminate is packaged in a bag, and the release paper is peeled from the prepreg laminate after the prepreg laminate is cured by a heating device while keeping the inside of the back packaging in a vacuum. A method characterized by.   The manufacturing method according to claim 7, wherein the heating device is an autoclave or an oven. A method for producing a fiber-reinforced composite material whose surface is embossed,
The substrate includes at least a support, a resin layer provided on the support, and a release layer provided on the resin layer, and the surface of the surface of the resin layer on which the release layer is provided is embossed. Prepare release paper with emboss
The release paper and the fiber reinforced composite material are bonded together via a coating resin so that the release layer of the release paper and the fiber reinforced composite material face each other, and heating and drying are performed.
Peeling the release paper from the fiber reinforced composite material, and embossing the surface of the fiber reinforced composite material.   A fiber-reinforced composite material obtained by the method according to any one of claims 7 to 9 and having a surface embossed.

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