JP5678483B2 - Fiber-reinforced plastic molded product with curved shape - Google Patents

Description

  The present invention relates to a fiber-reinforced plastic molded article that is required for light weight, high strength / rigidity, and high design, for example, used as a part or casing part of a personal computer, an OA device, a mobile phone, or the like. In particular, the present invention relates to a fiber-reinforced plastic molded product that requires high designability and has a curved shape.

  For casings used in electrical and electronic equipment products such as personal computers and mobile phones, in addition to achieving both high strength and light weight (thinning), it is also a part that can be seen by customers as a product. What is beautiful, that is, high designability has been demanded. In terms of design, a shape having a curved surface such as a curved shape has been required from the viewpoint of ease of use.

In order to achieve both high strength and light weight (thinning) of the casing, many materials using fiber reinforced members in which resin is reinforced with high-functional fibers such as glass fibers and carbon fibers have been proposed. The fiber base material used in the fiber-reinforced member, the reinforcing fiber bundle obtained by bundling a plurality of reinforcing fiber cloth material and which is the textile, UD material aligned pull the reinforcing fiber bundle in one direction (U ni- D irectional material) Etc.

  In addition, in order to give high appearance to the appearance of the fiber reinforced member, it has been proposed to arrange the fiber base material so that the woven pattern of the reinforcing fiber bundle appears on the outermost layer of the fiber reinforced member. At this time, if the weave pattern is uniformly formed on the surface of the fiber reinforced member, it can be used as a product, but if the weave pattern is disturbed, the design will be lost even if the strength is satisfied. In many cases, the product can no longer be used.

  Here, when a cloth material or a UD material is used as the outermost layer, the weave pattern of the cloth material or the UD material is used as a design surface as it is, but depending on the product shape, the weave pattern cannot be uniformly maintained during processing, etc. As a result, design properties may often not be obtained. For example, when a cloth material is applied to a shape having a bent portion such as a mobile phone casing, the woven pattern of the reinforcing fiber bundle may be displaced, and the uniform lattice pattern may be impaired. Further, when the UD material is applied, the reinforcing fiber bundle is bent and the reinforcing fiber bundle is bent due to the configuration unique to the UD material, or the surface condition of the adjacent fiber base material is affected. It is difficult to obtain a uniform weave pattern.

  In the past, various fiber reinforced members that achieve high designability in addition to achieving both high strength and light weight (thinning) have been proposed. In Patent Document 1, in a panel composed of a core material and a surface material, a carbon fiber reinforced plastic made of a pair of unidirectional carbon fiber prepregs in which fibers are obliquely crossed on the surface material is used, and an aromatic polyamide is used as the core material. By using a honeycomb formed from a non-woven fabric, a sandwich panel having a light weight and excellent impact resistance is provided. However, since the shape of the core material is a honeycomb, the carbon fiber prepreg may fall into the concave portion of the honeycomb, and it is considered difficult to adapt to a casing aiming at a design surface without unevenness.

  In Patent Document 2, a carbon fiber reinforced resin molded product in which a thermoplastic resin film is laminated on both sides of a carbon fiber reinforced thermosetting resin sheet and the smoothness of the surface is not impaired even in a high temperature environment. Realized. However, this method can achieve smoothness of the surface, but it is unrealistic to provide a new film layer on the outermost surface of the design surface, so that it is unrealistic to form a bent portion. At that time, the reinforcing fiber sheet slides sideways and the laminated body shape cannot be maintained, and it seems difficult to express a predetermined strength.

JP-A-5-208465 JP 10-138354 A

  An object of the present invention is to obtain a good appearance of a fiber-reinforced plastic molded article having a curved shape that cannot be achieved by a conventional method, in addition to increasing strength and weight, and this characteristic is required. It is to provide a fiber reinforced plastic molded article having a curved shape suitable for the intended use.

The present invention for solving the above problems employs the following configuration. That is,
(1) arranges a plurality tow in the same direction, composed of a multilayer structure composed of at least three or more layers comprising a continuous fiber-reinforced sheet matrix resin is impregnated in advance, the second layer from the outermost layer constituting the design surface A fiber-reinforced plastic molded article having a curved shape, characterized in that the nonwoven fabric sheet is sandwiched between the two, and is curved in a direction perpendicular to the orientation direction of the continuous fiber bundle of the outermost layer.
(2) The fiber-reinforced plastic molded product having the curved shape according to (1), wherein the nonwoven fabric sheet has a thickness of 0.005 mm to 0.1 mm.
( 3 ) The fiber-reinforced plastic molded product having a curved shape according to (1) or (2) , wherein the reinforcing fiber of the continuous fiber-reinforced sheet is a carbon fiber.
( 4 ) An electronic device housing comprising a fiber-reinforced plastic molded product having a curved shape of any one of (1) to ( 3 ).
It is.

  According to the present invention, while maintaining lightness and high rigidity, the flow of fibers in the continuous fiber reinforced sheet is suppressed without changing the thickness, and the lower layer weave pattern is made the outermost layer by sandwiching the nonwoven fabric layer. By eliminating the appearance, it is possible to improve the design, and to provide a composite molded product suitable for manufacturing a housing of an electric / electronic device such as a personal computer or a portable information terminal having these characteristics it can.

(A) perspective view, (b) schematic diagram showing a laminated configuration of a continuous fiber reinforced sheet and a nonwoven fabric sheet, and (c) variation of continuous fiber bundles in the outermost layer. It is a schematic diagram. (A) Perspective view in a fiber reinforced plastic molded product having a curved shape used as a comparative example, (b) Schematic diagram showing a laminated configuration of continuous fiber reinforced sheets, (c) Schematic diagram showing variation in continuous fiber bundles in the outermost layer .

  Hereinafter, a fiber-reinforced plastic molded product having a curved shape according to the present invention will be described with reference to the drawings.

  FIG. 1A is a perspective view of a fiber-reinforced plastic molded article 10 having a curved shape according to the present invention. The fiber-reinforced plastic molded article 10 having a curved shape has a laminated structure in which a nonwoven fabric sheet 13 is sandwiched between an outermost layer 11 and a support layer 12 as shown in FIG. The outermost layer 11 is a continuous fiber reinforced sheet, and the support layer 12 is formed by laminating one or more continuous fiber reinforced sheets.

  Examples of reinforcing fibers used in the continuous fiber reinforced sheet constituting the outermost layer 11 and the support layer 12 include metal fibers such as aluminum fibers, brass fibers and stainless fibers, polyacrylonitrile-based, rayon-based, lignin-based, pitch-based, etc. Inorganic fibers such as carbon fiber, graphite fiber, glass fiber, silicon carbide fiber, silicon nitride fiber, aramid fiber, polyparaphenylene benzobisoxazole (PBO) fiber, polyphenylene sulfide fiber, polyester fiber, acrylic fiber, nylon fiber Organic fibers such as polyethylene fibers can be used. These reinforcing fibers may be used alone or in combination of two or more. Among these, carbon fibers are preferable from the viewpoint of the balance of specific strength, specific rigidity, and lightness, and at least polyacrylonitrile-based carbon fibers are preferably included from the viewpoint of excellent specific strength and specific elastic modulus.

As the continuous fiber reinforced sheet used for the outermost layer 11 and the support layer 12, a UD material, a cloth material, and other woven fabrics can be used. The UD material is a sheet reinforced with a unidirectional continuous fiber bundle, and the cloth material includes a sheet woven with a longitudinal fiber bundle and a transverse continuous fiber bundle. In addition to these, any sheet-like woven fabric in which reinforcing fibers are oriented can be used. Among these, a UD material is preferable from the viewpoint of smoothness without a texture unevenness like a vertical cloth material. In addition, although there is no restriction | limiting in particular in the number of the reinforced fiber which comprises a continuous fiber bundle, It is preferable to set it as the range of 3,000-24,000. When the number is less than 3,000, the continuous fiber bundle itself becomes thin, and sufficient fiber bundles are not arranged on the sheet, making it difficult to form a UD material or a cloth material. On the other hand, if the number exceeds 24,000, the continuous fiber bundle becomes conversely thick, making it difficult to form a continuous fiber reinforced sheet having a uniform thickness. Especially preferably, it is the range of 6,000-12,000. The basis weight of the continuous fiber reinforced sheet is not particularly limited, but is preferably in the range of about 140 to 170 g / m ^{2 from} the viewpoint of good handling properties at the time of lamination.

  The sheet containing reinforcing fibers used for the support layer 12 may be composed of a plurality of layers containing reinforcing fibers.

  The continuous fiber reinforced sheet used for the support layer 12 may be a continuous fiber reinforced sheet in which a plurality of reinforcing fibers are combined, or a continuous fiber reinforced sheet partially including fibers other than reinforcing fibers. May be.

  As the resin used as the matrix resin of the continuous fiber reinforced sheet, either a thermoplastic resin or a thermosetting resin can be suitably used. Examples of the thermoplastic resin include polyester resins such as polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polytrimethylene terephthalate (PTT) resin, polyethylene naphthalate (PEN) resin, liquid crystal polyester resin, and polyethylene ( In addition to polyolefin resin such as PE) resin, polypropylene (PP) resin, polybutylene resin, styrene resin, polyoxymethylene (POM) resin, polyamide (PA) resin, polycarbonate (PC) resin, polymethylene methacrylate (PMMA) ) Resin, polyvinyl chloride (PVC) resin, polyphenylene sulfide (PPS) resin, polyphenylene ether (PPE) resin, modified PPE resin, thermoplastic polyimide (PI) resin, polyamideimide ( AI) resin, polyetherimide (PEI) resin, polysulfone (PSU) resin, modified PSU resin, polyethersulfone (PES) resin, polyketone (PK) resin, polyetherketone (PEK) resin, polyetheretherketone (PEEK) ) Resin, polyether ketone ketone (PEKK) resin, polyarylate (PAR) resin, polyether nitrile (PEN) resin, thermoplastic phenol resin, phenoxy resin, polytetrafluoroethylene resin and other fluorine resins, and polystyrene Resins, polyolefin resins, polyurethane resins, polyester resins, polyamide resins, polybutadiene resins, polyisoprene resins, thermoplastic elastomers such as fluorine resins, and their copolymers, modified products, and two types Bren The resin and the like. Examples of thermosetting resins include unsaturated polyester resins, vinyl ester resins, epoxy resins, phenol (resole type) resins, urea / melamine resins, polyimide resins, and the like, copolymers, modified products thereof, and these Examples thereof include resins obtained by blending at least two kinds. Among these, since it is excellent in rigidity and strength, a thermosetting resin is preferable, and in particular, a thermosetting resin containing an epoxy resin as a main component is more preferable from the viewpoint of mechanical properties of a molded product. The matrix resin may be a resin obtained by adding a thermoplastic resin and / or other elastomer or rubber component to a thermosetting resin for the purpose of improving impact resistance.

  As another preferred embodiment of the matrix, metals such as titanium, magnesium, and aluminum can be used in addition to the resin.

  As the nonwoven fabric sheet 13, a nonwoven fabric made of a thermoplastic resin or a thermosetting resin can be used. Among these, a thermoplastic resin that softens at a high temperature and has good adhesion to the fiber-reinforced resin sheet is particularly preferable. Examples of the thermoplastic resin include polyolefin resins such as polyethylene (PE) resin, polypropylene (PP) resin, and polybutylene resin, polystyrene (PS) resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, and acrylonitrile-styrene. Styrenic resin such as copolymer (AS) resin, polyethylene terephthalate (PET) resin, polybutylene terephthalate (PBT) resin, polytrimethylene terephthalate (PTT) resin, polyethylene naphthalate (PEN) resin, liquid crystal polyester resin, etc. Polyester resin, polyoxymethylene (POM) resin, polyamide (PA) resin, polycarbonate (PC) resin, polymethyl methacrylate (PMMA) resin, polyvinyl chloride (PVC) resin, polypheny Sulfide (PPS) resin, polyphenylene ether (PPE) resin, modified PPE resin, thermoplastic polyimide (PI) resin, polyamideimide (PAI) resin, polyetherimide (PEI) resin, polysulfone (PSU) resin, modified PSU resin , Polyethersulfone (PES) resin, polyketone (PK) resin, polyetherketone (PEK) resin, polyetheretherketone (PEEK) resin, polyetherketoneketone (PEKK) resin, polyarylate (PAR) resin, polyether Fluorine resins such as nitrile (PEN) resin, thermoplastic phenol resin, phenoxy resin, polytetrafluoroethylene (PTFE) resin, polystyrene, polyolefin, polyurethane, polyester, polyamide, polybene Diene, polyisoprene, thermoplastic elastomers and fluorine such as, copolymers thereof, modified products, and two or more of the blend, such as polymer alloys and the like. Among these, polyethylene terephthalate (PET) resin is particularly preferable from the viewpoint of heat resistance and cost. Alternatively, a sheet in which the nonwoven fabric sheet 13 is impregnated with resin may be used. The resin to be impregnated is not particularly limited, but in order to obtain a lightweight and high-strength fiber-reinforced plastic molded product, it is preferable to use the same resin as the matrix resin described above.

  As described above, the fiber-reinforced plastic molded article 10 having a curved shape of the present invention has a nonwoven fabric sheet 13 between the outermost layer 11 made of a continuous fiber-reinforced sheet and the support layer 12 on which the continuous fiber-reinforced sheets are laminated. It consists of a sandwiched structure. It is preferable that the outermost layer 11 has one layer and the support layer 12 has a configuration in which two or more continuous fiber reinforced sheets are laminated.

  The combination of the continuous fiber reinforced sheets constituting the outermost layer 11 and the support layer 12 is not particularly limited, but continuous fibers having the same woven structure in order to exhibit a predetermined strength and the like with a small number of laminated layers. It is preferable to use a reinforcing sheet.

About the lamination | stacking method of the outermost layer 11 and the support layer 12, the continuous fiber reinforcement sheet | seat so that the laminated body which consists of the outermost layer 11 and the support layer 12 except the nonwoven fabric sheet 13 becomes symmetrical toward both surface layers from the center of a laminated body. It is preferable to arrange a weave structure. Here, when the number of continuous fiber reinforced sheets constituting the outermost layer 11 and the support layer 12 is an even number, the arrangement is symmetrical with respect to the contact surface of the continuous fiber reinforced sheets, which is half of the number of laminated layers. In the case of an odd number, the continuous fiber reinforced sheets arranged on both sides of the continuous fiber reinforced sheet are arranged symmetrically with respect to the continuous fiber reinforced sheet arranged in the center. Furthermore, it is more preferable that the fiber orientations of the respective continuous fiber reinforced sheets are arranged so as to be symmetrical. For example, when 6 layers of UD materials made of the same weave structure are laminated (even number), the fiber arrangement direction is 0 ° / 90 ° / 0 ° / 0 ° / 90 ° / 0 ° from the top. Can do. When seven layers of UD materials are laminated (odd number), they can be laminated so that the fiber arrangement direction is 0 ° / 90 ° / 0 ° / 90 ° / 0 ° / 90 ° / 0 ° from the top. Here, 0 ° is a state in which the continuous fiber bundle is oriented parallel to the arrow in the continuous fiber bundle arrangement direction in FIG. 1A, and 90 ° is a state in which the continuous fiber bundle is oriented so as to be orthogonal to the arrow. Point to. When the continuous fiber reinforced sheets are arranged symmetrically in this way, a fiber reinforced plastic molded product without warping or bending can be obtained. On the contrary, if it is not symmetrically arranged, it causes warping and bending due to the orientation of the continuous fiber bundle.

In the present invention, it is important that the nonwoven fabric sheet 13 is sandwiched between the outermost surface layer 11 and the second surface layer serving as a design surface. When the nonwoven fabric sheet 13 absorbs the unevenness of the continuous fiber bundle of the continuous fiber reinforced sheet and makes the laminated body of the continuous fiber reinforced sheet including the nonwoven fabric sheet 13 into a curved shape, as shown in FIG. Variations in the continuous fiber bundles constituting the outermost layer 11 can be suppressed, and the design of the outermost layer 11 can be enhanced.

As described above, the outermost layer 11 and the support layer 12 may be laminated in different fiber directions so as to be orthogonal to each other by 90 °. In the UD material in which a plurality of continuous fiber bundles having a substantially circular or elliptical cross section are arranged in the same direction, a concave portion is formed in the vicinity of the boundary where the continuous fiber bundles contact each other. A continuous fiber bundle may fall into this recess and form irregularities on the surface. Furthermore, in continuous fiber reinforced sheets such as UD materials, the cross-sectional shape of continuous fiber bundles is not always uniform, and there are many variations (fiber density differences) in the gaps between continuous fiber bundles. For this reason, when the number of laminated layers increases, unevenness is likely to be formed on the surface due to such a variation in continuous fiber bundles. Also in the present invention, it is considered that the unevenness is formed on the surface of the support layer 12. When the outermost layer 11 is laminated directly on the support layer 12, the influence of the unevenness on the surface of the support layer 12 is affected. As a result, it becomes difficult to smooth the surface of the outermost layer 11.

When the nonwoven fabric sheet 13 is disposed on the surface of the support layer 12, irregularities on the surface of the support layer 12 can be absorbed by the random fiber orientation of the nonwoven fabric sheet 13. In addition, even when the outermost layer 11 is placed on the nonwoven fabric sheet 13, the unevenness due to the variation of the continuous fiber bundle of the outermost layer 11 itself is absorbed by the nonwoven fabric sheet 13, so that the support layer 12 is affected. There is no. Therefore, as shown in FIG.1 (c), the smoothness of outermost layer 11 itself can be expressed as the design property of a fiber reinforced plastic molding as it is.

  Furthermore, since the fiber direction of the nonwoven fabric sheet 13 is random, there is a fiber facing in the direction of the outermost layer 11 and the support layer 12, that is, the thickness direction of the fiber-reinforced plastic molded product. By being caught on the surface of the support layer 12, the anchor effect can be exhibited and high adhesion with the outermost layer 11 and the support layer 12 can be expressed.

Here, in the fiber reinforced plastic molded product having a curved shape in a direction orthogonal to the orientation direction of the continuous fiber bundle of the outermost layer as in the present invention, when the nonwoven fabric sheet 13 is not present as shown in FIG. As shown in FIG. 2 (c), the spacing between the continuous fiber bundles tends to vary in the curved portion. In the curved shape, the resin easily flows and the fiber density is different, so that a portion of the resin alone in which no reinforcing fiber is present is formed. As will be described later, when the resin is cured, sink marks are generated only in the resin, and the surface of the outermost layer 11 may be uneven. When the nonwoven fabric sheet 13 is placed, not only is the influence of the unevenness on the surface of the support layer 12, but the continuous fiber bundle of the outermost layer 11 is less likely to vary along the curve due to the fibers facing the thickness direction of the fiber-reinforced plastic molded product. In addition, since the softened resin flows into the nonwoven fabric sheet 13, variations in density difference are less likely to occur, and a curved shape in which continuous fiber bundles are evenly arranged can be formed. As a result, it is difficult to form a resin-only portion on the outermost layer 11, and it is difficult for sink marks to occur during curing, and it is possible to express smoothness and high design.

Incidentally, FIG. 1 (c), the FIG. 2 (c) both, has been described in example tow as the outermost layer 11 has a UD material unidirectionally oriented continuous fiber-reinforced sheet, the present invention is not limited thereto It is also possible to use a cloth material. In the case of the cloth material, since the continuous fiber bundles are configured to be orthogonal to each other, any material having a curved shape in the direction orthogonal to the orientation direction of any one of the continuous fiber bundles may be used.

  Here, the thickness of the nonwoven fabric sheet 13 is preferably 0.005 mm to 0.1 mm in order to suppress the thickness of the entire fiber reinforced plastic molded product 10 having a curved shape. If it is thicker than 0.1 mm, the symmetry of the continuous fiber reinforced sheet is lost, and warping may occur. When the thickness is less than 0.005 mm, it is difficult to expect the effect of suppressing the appearance of the lower layer weave pattern because the lower layer unevenness cannot be sufficiently absorbed due to its thinness. In consideration of the increase in thickness and the influence of warpage, 0.005 mm to 0.03 mm is more preferable.

The molding process which is the subject of the present invention is a process for obtaining a plate-shaped molded article by pressurizing and simultaneously curing a laminate having a prepreg impregnated with a matrix resin in advance as a continuous fiber reinforced sheet. The method is not particularly limited as long as it is a method that allows easy molding. For example, a method of pressing with a release film by applying pressure between a pair of heated molds by hydraulic pressure, etc., or a bag film placed on a prepreg laminate placed on one mold The bag method for obtaining pressure by vacuum suction between the mold and the bag film, and further the autoclave method for pressurizing the outside of the bag film with gas, etc., any molding process can be used, It can be selected according to the required characteristics of the molded product and the type of matrix resin.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, the main point of this invention is not limited to a following example. Table 1 shows the stacked structure and effects of Examples 1 to 6, and Table 2 shows the stacked structure and effects of the surface layers and the second layer of Comparative Examples 1 to 5.

Example 1
Carbon fiber unidirectional prepreg (UD PP) P3052S-15 (using carbon fiber T700S manufactured by Toray Industries, Inc., matrix resin: epoxy resin, carbon fiber content 67%, thickness 0.143 mm) as the outermost layer, nonwoven fabric sheet as the second layer (PET non-woven fabric thickness 0.038mm), carbon fiber unidirectional prepreg (UD PP) P3052S-15 (Toray Industries, Inc. carbon fiber T700S used as a fiber reinforced member in the 3rd to 6th layers from the design surface Matrix resin: Epoxy resin The carbon fiber content was 67%, the thickness was 0.143 mm), and the same carbon fiber unidirectional prepreg as the outermost layer was sequentially laminated on the seventh layer. The thickness of the PET nonwoven fabric was measured with a micrometer based on JIS K7130 (1999). When the longitudinal direction of the fiber reinforced plastic molded product is 0 °, the orientation of the carbon fiber is 0 ° / nonwoven fabric / 90 ° / 0 ° / 0 ° / 90 ° / 0 ° in order from the outermost layer. They were laminated so that The laminate sandwiched between release films is press-molded (die temperature 150 ° C., pressure 1.5 MPa, curing time 30 minutes, target thickness after pressing 0.8 mm), as shown in FIG. A fiber-reinforced plastic molded product having a curved shape was obtained. This molded product was processed into a size of 242.90 mm × 189.75 mm, set in an injection mold, and clamped, and then a long fiber pellet TLP1146S (carbon fiber content manufactured by Toray Industries, Inc.) 20%, base resin: polyamide 6; solubility parameter δ (SP value) 13.6, resin flow direction molding shrinkage: 0.1%) was produced as a composite molded product by injection molding at the peripheral edge of the molded product. As a result, no black streak-like irregularities or sink marks were observed at the end of the curved outermost layer, and a composite molded article having a very good design and a good appearance was obtained.

(Example 2)
The prepreg used in the outermost layer and the seventh layer from the outermost layer is carbon fiber unidirectional prepreg (UD PP) P3052S-17 (carbon fiber T700S manufactured by Toray Industries, Inc.) Matrix resin: epoxy resin Carbon fiber content 67% Thickness 0. 167 mm), a laminate having the same structure as in Example 1 is formed, press molding is performed under the same conditions as in Example 1, and the same long fiber pellet as in Example 1 is injection molded to form a composite molded product. Manufactured. Although the resin on the outermost layer is relatively thick, there are no black streak-like irregularities or sink marks at the end of the molded product on the outermost layer, and a composite molded product with an extremely high design and a good appearance can be obtained. It was.

Example 3
The prepreg used in the outermost layer and the seventh layer from the outermost layer is carbon fiber unidirectional prepreg (UD PP) P3251S-15 (using carbon fiber T700S manufactured by Toray Industries, Inc.) Matrix resin: epoxy resin Carbon fiber content 63% Thickness 0. 151 mm), a composite molded product was produced in the same manner as in Example 1. This composite molded article has a resin ratio of the outermost layer higher than that in Example 1, but no black streak-like irregularities or sink marks are observed at the end of the molded article in the outermost layer, and it has extremely high design properties. A composite molded article having a good appearance was obtained.

Example 4
The prepreg used in the outermost layer and the seventh layer from the outermost layer is carbon fiber unidirectional prepreg (UD PP) P3255S-17 (using carbon fiber T700S manufactured by Toray Industries, Inc.) Matrix resin: epoxy resin Carbon fiber content 75% Thickness 0. 142 mm), a composite molded product was produced in the same manner as in Example 1. Similar to Examples 1 to 3, no black streak-like irregularities or sink marks were observed at the end of the molded product on the outermost layer, and a composite molded product having a very good design and a good appearance was obtained.

(Example 5)
A composite molded product was produced in the same manner as in Example 1 except that the basis weight of the second layer nonwoven fabric sheet was changed to a thick one (PET nonwoven fabric thickness 0.15 mm). In the outermost layer, a resin-deficient portion with no problem in appearance was generated, and a composite molded product having a good appearance with no black streak-like irregularities or sink marks at the end of the molded product was obtained.

(Example 6)
A composite molded article was produced in the same manner as in Example 1 except that the second-layer nonwoven fabric sheet was a glass nonwoven fabric. Even when a glass nonwoven fabric is used as the material of the nonwoven fabric sheet, there are no black streak-like irregularities or sink marks at the end of the molded product on the outermost layer, and a composite molded product with a very good design and a very good appearance can be obtained. It was.

(Comparative Examples 1-4)
A composite molded article was produced by combining the same prepreg as in Examples 1 to 4 except that the nonwoven fabric sheet was not sandwiched between the outermost layer and the support layer. As a result, in any of the molded products, black streak-like uneven sink marks due to variations in the fiber density of the continuous fiber bundle occurred at a high rate at the end of the curved outermost layer.

(Comparative Example 5)
The same carbon fiber unidirectional prepreg as in Example 1 was prepared, and the same structure as in Example 1 except that the same nonwoven fabric sheet as in Example 1 was laminated in the third layer instead of the second layer from the outermost layer. A composite molded article was produced under the same conditions as in Example 1. As a result, black streaky irregularities and sink marks were generated at the end of the curved outermost layer. It was confirmed that even if a non-woven sheet was arranged in the third layer, the effect was not improved with respect to the improvement of the design property.

  Examples of the use of the electronic device casing made of the fiber reinforced sheet according to the present invention include a parabona antenna, a personal computer, a notebook computer, a mobile phone, a digital still camera, a digital video camera, a PDA, a portable MD, and a home game machine. Useful for electronic equipment casings. Among them, it is useful for electronic equipment casings such as notebook personal computers, mobile phones, and PDAs, which are highly rigid and lightweight, and at the same time require good design.

DESCRIPTION OF SYMBOLS 10 Fiber reinforced plastic molding 11 which has curved shape Outermost layer 12 Support layer 13 Nonwoven fabric sheet

Claims (4)

Arranging a plurality of continuous fiber bundles in the same direction, the nonwoven fabric sheet in the second layer from the outermost surface layer composed of a multilayer structure composed of at least three or more layers comprising a continuous fiber-reinforced sheet matrix resin is impregnated in advance, it constitutes a design surface Is a fiber-reinforced plastic molded article having a curved shape, characterized by being bent in a direction perpendicular to the orientation direction of the continuous fiber bundle of the outermost layer. The fiber-reinforced plastic molded article having a curved shape according to claim 1, wherein the nonwoven fabric sheet has a thickness of 0.005 mm to 0.1 mm. The fiber-reinforced plastic molded article having a curved shape according to claim 1 or 2 , wherein the reinforcing fibers of the continuous fiber-reinforced sheet are carbon fibers. Electronics enclosure which comprises a fiber-reinforced plastic molded article having any curved shape of the claims 1-3.

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