JP2005067021A - Frp molding and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an FRP molding which is light in weight and excellent in surface quality by preventing the inside of a core material from being impregnated with a matrix resin. <P>SOLUTION: In the FRP molding, reinforcing fibers arranged around the core material are impregnated with the matrix resin. The contact of the matrix resin with the core material is cut off by coating the surface of the core material 1 with a film 2. Even when the matrix resin is injected at a high pressure, or a low density core material is used, the inside of the core material is prevented from being impregnated with the matrix resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an improvement of an FRP molded product (fiber reinforced resin molded product). In particular, even when a matrix resin is injected at a relatively high pressure during molding or when a low-density core material is used, the resin is a core material. The present invention relates to a lightweight and excellent surface quality FRP molded product that does not impregnate inside and a manufacturing method thereof. The FRP molded product of the present invention can be applied to industrial members that are lightweight and are required to have a relatively high design for appearance quality, for example, represented by transportation equipment such as automobiles and airplanes.

  In conventional FRP molded products, when the matrix resin is impregnated into the reinforcing fibers arranged around the core material, the matrix resin is often impregnated into the core material. In the case of a core material obtained by injection foaming, this phenomenon occurs when the foam cell structure forming the core, such as the core material end or a thin part, is uneven and the weak cell part or foam cell structure is broken. As a result, there is a problem that the weight increases because the matrix resin that is not originally required as an FRP molded product is included in the product, and the amount of resin locally increases in the matrix resin-impregnated portion. As a result, the smoothness of the surface of the FRP molded product is impaired due to the heat generated by the resin and the shrinkage due to curing, the surface quality is deteriorated, and the value as a product requiring surface design properties is lowered.

  In the conventional technology to prevent the matrix resin from being impregnated into the core material, a thin resin layer is formed on the surface of the polyurethane foam core, and then it is set in the mold together with the fiber base material, and the matrix resin liquid for FRP is injected. Thus, the matrix resin is prevented from penetrating into the core (for example, see Patent Document 1). However, in this method, since it is difficult to make the thickness of the resin layer formed on the core material surface uniform, unevenness is generated on the surface of the resin layer, and the surface quality of the FRP molded product deteriorates due to the unevenness. there were. Furthermore, the resin itself that forms the resin layer at the time of application of the resin layer impregnates the core material, which deteriorates the lightness and surface quality, and the thickness of the resin layer is as thick as about 0.05 to 0.5 mm. There was a problem that the light weight merit was impaired by its own weight.

In order to reduce the impregnation of the matrix resin into the core material, there is a method such as using a high-density core material, but particularly when the matrix resin is injected at a high pressure, the matrix resin is not sufficiently shut off, Furthermore, the use of a high-density core material increases the weight of the FRP molded product, and there is a problem that the light weight merit that is one of the major features of the FRP molded product is impaired.
Japanese Patent Laid-Open No. 5-147048

  In view of the above problems, the present invention does not impregnate the matrix resin into the core material, especially when the matrix resin is injected at a relatively high pressure during molding or when a low-density core material is used. It is an object of the present invention to provide an FRP molded product that is lightweight and excellent in surface quality and a method for producing the same.

  In order to achieve the above object, the FRP molded product of the present invention has the following configuration.

That is, in FRP molded products,
(1) In an FRP molded article comprising a core material and a reinforcing fiber resin skin layer laminated on at least one side of the core material, at least a part of the surface of the core material is interposed between the core material and the skin layer. An FRP molded product characterized in that a film to be coated is interposed.
(2) The FRP molded product is characterized in that a range covered with the film is the entire surface of the core material.
(3) An FRP molded product characterized in that a sealing material is applied to an end of the film.
(4) The FRP molded product is characterized in that the film is subjected to corona treatment on at least a surface in contact with the matrix resin constituting the FRP molded product.
(5) The FRP molded product, wherein the core material is a foam core foam.
(6) The FRP molded product is characterized in that the foam core foam is a rigid polyurethane foam.

  Moreover, in order to achieve the said subject, the manufacturing method of the FRP molded product of this invention covers at least one part of the surface of a core material with a film, and also arrange | positions the reinforced fiber base material in the circumference | surroundings, Then, by RTM method The reinforcing fiber base material is impregnated with a matrix resin.

  The FRP molded product of the present invention covers the surface of the core material with a film at the time of production, so that even when the density of the core material is low or when the matrix resin is injected at a high pressure, The matrix resin is not impregnated, and as a result, it is characterized by being lighter, superior in surface quality, and having higher commercial value than conventional products. Therefore, for example, it can be applied to industrial members that are required to have a light weight and a relatively high design quality in appearance quality, as represented by transportation equipment such as automobiles and airplanes.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective partial sectional view showing a configuration of an FRP molded product according to an embodiment of the present invention. In FIG. 1, 1 indicates a core material. The core material in the present invention is a core material having a sandwich structure composed of a reinforcing fiber resin skin layer, which is an FRP layer 3 impregnated with a matrix resin in a so-called FRP molded product, and a core material. The reinforcing fiber resin skin layer may be disposed on the entire surface of the core material, or the reinforcing fiber resin skin layer is not disposed on the surface, and the core material is exposed on the surface of the FRP molded product. Also good.

  As the core material 1, for example, a wood core can be used, but in order to make the FRP molded product lightweight, it is desirable that the core material is made of a foam core foam.

The material of the foam is not particularly limited, and resin foams such as polystyrene, polyolefin, acrylic, polyimide, and polyurethane can be used. A rigid polyurethane foam having an apparent density of 0.025 g / cm ³ or more is most preferably used because it has such a strength that it is not crushed by pressure.

  The shape of the core material can be obtained by cutting out or cutting out from the block, or by injecting a foamed stock solution mixed and stirred into an injection foaming mold made into an arbitrary shape and foaming it inside the mold. When the core material is used, the latter can be used for efficient production.

  The material of the film 2 that covers at least a part of the surface of the core material 1 is not particularly limited. For example, nylon, polyester, polypropylene, polyethylene, vinyl chloride, polyvinylidene chloride, and the like can be used. If the temperature does not exceed the maximum temperature during curing, the matrix resin for forming the FRP layer 3 may enter the inner surface of the film 2 and come into contact with the core material 1 to be impregnated into the core material 1. So be careful. The surface of the film 2 is preferably subjected to a surface treatment by corona discharge in air, nitrogen, carbon dioxide, or the like, so-called corona treatment. At least, when a film subjected to corona treatment on the surface in contact with the matrix resin constituting the FRP molded product is used, the adhesiveness between the matrix resin and the film 2 is improved, so that the FRP layer 3 and the film 2 are firmly bonded, Substantially, the FRP layer 3 and the film 2 can be integrated.

  Although the film thickness is less likely to reduce the surface quality of the FRP molded product, the film thickness is preferably about 3 to 50 μm and more preferably 10 to 30 μm because the workability deteriorates if it is too thin. . In addition, for example, by selecting a film having low hygroscopicity, an effect of preventing the core material from absorbing moisture can be expected.

  The film is covered by folding the film of the surplus part or cutting the film and overlapping the surplus part at the part where the surface of the core material is curved so that the gap generated between the film and the core is small. It is effective. At this time, if an adhesive component is applied to the core material or the film surface in contact with the core material, positioning of the core material and the film is facilitated, and workability is improved. Moreover, workability improves similarly even if it uses the film which coated the adhesive component previously.

  At the portion where the film is cut or at the end of the film, for example, the films are bonded together with a sealing material made of an adhesive component such as glue or adhesive resin, or the ends of the film 2a and the film 2b as shown in FIG. When the portions are overlapped or butted together and a pressure-sensitive adhesive tape 4 coated with glue, adhesive resin, or the like is applied as a sealing material and coated, the core material 1 can be prevented from being impregnated with the matrix resin. The component of the sealing material is not particularly limited, but it is preferable to use a heat-resistant material such as acrylic or silicone in consideration of heat generation when the matrix resin is cured. Although the base film in the case of using an adhesive tape is not particularly limited, it is preferable to use a heat-resistant material such as polyester or nylon. Alternatively, even when heat-sealed with a tape made of a heat-sealing resin or the like, the matrix resin can be prevented from penetrating from the joint between the film 2a and the film 2b and impregnating the core material 1. . The heat-sealing resin is not particularly limited, and commercially available resins such as polyester-based, acrylic-based, polyamide-based, modified polyolefin-based polymers and copolymers, modified products, and ionomers can be used. Those can be particularly preferably used.

  If the entire surface of the core material is covered with a film, the core material and the matrix resin can be completely blocked, and the core material can be effectively prevented from being impregnated with the matrix resin. In addition, if only the portion where the structure forming the core material is weak and easily impregnated with the matrix resin is selectively covered with a film, the working efficiency is improved. Moreover, after using a heat-shrinkable film and arranging the film on the entire circumference of the core material surface, the film is shrunk by applying hot air to the film or by exposing the film to a high temperature environment. A method of bringing the film into close contact is also effective. Furthermore, the film processed into a bag shape is covered so as to cover the entire core material, and after sealing the portion other than the suction port, the inside of the film is vacuum-sucked to adhere to the entire core material, and then the suction port is sealed and the It is also effective to maintain adhesion to the core material.

  The reinforcing fibers are appropriately arranged around the core material covered with the film. The form of arrangement and the laminated structure are not particularly limited. The reinforcing fibers used are not limited, and carbon fibers, glass fibers, aramid fibers, reinforcing fibers using these in combination, and the like are used.

  The matrix resin is not particularly limited, but examples thereof include thermosetting resins such as epoxy resins, unsaturated polyester resins, phenol resins, and vinyl ester resins, thermoplastic resins such as polyester, polyolefin, polyamide resin, and polypropylene resin, and These mixed resins can be used.

  The method for impregnating the reinforcing fiber base material with the matrix resin is not particularly limited, but an RTM (Resin Transfer Molding) method is preferably used. When the RTM method is used, the matrix resin can be injected at a high pressure, and as a result, an FRP molded product having no surface impregnated portion or surface bubbles and excellent surface quality can be efficiently produced.

  Next, a preferred embodiment for molding the FRP molded product according to the present invention by the RTM method will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view of a molding apparatus for carrying out a method for manufacturing an FRP molded product according to an embodiment of the present invention.

  In the figure, first, the surface of the core material 1 is covered with a film 2 and a reinforcing fiber base 5 is disposed around the core 2 and then accommodated in a cavity 7 of a mold 6 composed of an upper mold 6a and a lower mold 6b. Next, the cavity 7 is kept sealed by a seal 8 attached to the lower mold 6b. Next, the inside of the cavity is depressurized by connecting to the vacuum source 9 while maintaining the sealed state in the mold. Thereafter, the injection cock 10 is opened, the liquid matrix resin 11 is injected under pressure, and the reinforcing fiber base 5 disposed in the cavity 7 is impregnated. Next, the matrix resin 11 impregnated in the reinforcing fiber base 5 is cured at an appropriate temperature, whereby an FRP molded product is obtained.

<Example>
First, as shown in FIG. 1, a 600 mm × 200 mm × 20 mm plate shape in which two liquids of a polyol and an isocyanate containing appropriate amounts of water as a reaction catalyst were mixed and stirred at a ratio of 1: 1 and foamed in an injection foaming mold. 15 μm thick nylon film (Unitika Ltd.) with a hard polyurethane foam (appearance specific gravity 0.16 g / cm 3) as a core material 1 and the entire surface of which is corona-treated on one surface of the film surface A biaxially stretched nylon film “Emblem” ONBC-15) 2 was used. At this time, the surface subjected to the corona treatment was coated so as to be the outer surface. At this time, one film was used for each of the upper and lower sides of the plate shape, and a polyester adhesive tape was applied to the portion where the two films were combined to prevent the formation of a gap. Further, the plate-like end face was appropriately folded or the excess part was cut off, and a polyester adhesive tape was similarly applied to the part where the film overlaps or the part where the gap was generated, thereby preventing the gap from being formed in the film.

  Next, a 3-ply carbon fiber plain fabric with a basis weight of 190 g / m2 using carbon fiber ("Torayca" T300-3K yarn manufactured by Toray Industries, Inc.) is laminated on the entire surface of the hard polyurethane foam covered with film. And it accommodated in the cavity 7 of the shaping | molding die comprised from the upper and lower metal mold | dies 6a and 6b shown in the manufacturing apparatus of FIG.

  Thereafter, the inside of the mold was decompressed, and a liquid epoxy resin was injected into the mold by applying a pressure of 0.6 MPa, impregnated into the reinforcing fiber base material, and cured in the mold to produce an FRP molded product.

  The resulting FRP molded product weighed about 900 g. Further, the surface of the FRP molded product was excellent in surface quality because there was no surface roughness generated when the amount of the matrix resin was excessive.

  When the FRP molded product was cut and the cross section was observed, the cross section was impregnated with the matrix resin only in the FRP layer, and the core material 1 was not impregnated with the matrix resin at all, as seen in FIG. Further, the film 2 was strongly adhered to the matrix resin and was integrated with the FRP layer 3.

<Comparative example>
For the examples, FRP molded products were produced in the same manner except that the surface of the core material using the rigid polyurethane foam was not covered with a film. The resulting FRP molded article weighed about 1150 g, an increase of about 28% over the weight when coated with a film. In addition, the surface of the FRP molded product had a partially rough surface, so that the surface quality was poor and the product design was not sufficient.

  When the FRP molded product obtained by the method of the comparative example is cut and the cross section is observed, the cross section is seen in FIG. 5, and the matrix resin that should be impregnated only in the FRP layer 3 is the surface of the core material 1. It was confirmed that the resin-impregnated layer 12 was impregnated from the inside toward the inside.

  The FRP molded product of the present invention is applied to industrial members that are lightweight and are required to have a relatively high design for appearance quality, for example, represented by transportation equipment such as automobiles and airplanes.

It is sectional drawing of the perspective part which shows the structure of the FRP molded product which concerns on one embodiment of this invention. It is sectional drawing of the part which shows the sealing method of the film edge part which concerns on one embodiment of this invention. It is a schematic sectional drawing of the shaping | molding apparatus which enforces the manufacturing method of the FRP molded article which concerns on one embodiment of this invention. It is a partial cross section photograph which shows the shape of the fiber of the FRP molded product manufactured in the Example of this invention. It is a partial cross section photograph which shows the shape of the fiber of the FRP molded product manufactured by the comparative example.

Explanation of symbols

1: Core material 2: Film 3: FRP layer 4: Adhesive tape 5: Reinforcing fiber substrate 6: Mold 6a: Upper mold 6b: Lower mold 7: Cavity 8: Seal 9: Vacuum source 10: Injection cock 11: Matrix Resin 12: Resin impregnated layer

Claims (7)

In an FRP molded article comprising a core material and a reinforcing fiber resin skin layer laminated on at least one side of the core material, a film covering at least a part of the surface of the core material between the core material and the skin layer FRP molded product characterized by interposing. The FRP molded product according to claim 1, wherein the range covered with the film is the entire surface of the core material. The FRP molded product according to claim 1, wherein a sealing material is applied to an end of the film. The FRP molded product according to any one of claims 1 to 3, wherein the film is subjected to corona treatment on at least a surface in contact with a matrix resin constituting the FRP molded product. The FRP molded product according to any one of claims 1 to 4, wherein the core material is a foam core foam. The FRP molded article according to claim 5, wherein the foam core foam is a rigid polyurethane foam. An FRP molded article characterized in that at least a part of the surface of the core material is coated with a film, and further, a reinforcing fiber base material is disposed around the core material, and then the reinforcing fiber base material is impregnated with a matrix resin by the RTM method. Production method.