JP4529371B2 - Foamed resin core built-in FRP and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an FRP with a built-in foamed resin core that is lightweight and applicable to, for example, automobile body parts, bumpers, spoilers, and the like, and has excellent flexibility.
[0002]
[Prior art]
Conventionally, weight reduction of various parts such as metal molding materials, especially automobile bodies, bumpers, spoilers, etc. has been studied, but recently resin molded products that have both toughness and toughness have been developed. . For example, a foamed resin molded product made of polystyrene or the like is used as a core, and a fiber base material such as glass fiber or carbon fiber is coated on the outside, and then the resin is impregnated and cured, which is made of fiber reinforced plastic (hereinafter referred to as FRP). Drying and curing after applying bumper (Patent Document 1) or thermosetting resin-based paint such as unsaturated polyester resin, epoxy resin, polyurethane or thermoplastic resin such as acrylic resin to the surface of foamed polyurethane core A method of manufacturing an FRP product with a foamed polyurethane core in which a thin resin layer is set in a mold together with a fiber base material and an FRP resin solution is injected and cured has been proposed (Patent Document 2).
[0003]
[Patent Document 1]
JP-A-2-215519 (Claim 1, FIGS. 1-4)
[0004]
[Patent Document 2]
Japanese Patent Laid-Open No. 5-147048 (Claim 1, FIG. 1)
[0005]
[Problems to be solved by the invention]
However, the FRP having the foamed resin molded product proposed in Patent Documents 1 and 2 as a core has the following problems.
[0006]
That is, in Patent Document 1, as described above, a foamed resin molded product is used as a core, and after the fiber base material is coated on the outside, the resin is impregnated and cured. Because the resin penetrates, weight reduction is impaired, and the surface of the product looks discolored due to the penetration spots in such a case, and in extreme cases, unevenness is generated and the quality and gloss are significantly reduced. It was extremely poor productivity. On the other hand, in Patent Document 2, the drawback is improved, that is, the resin is applied to the surface of the foamed polyurethane core to prevent the resin injected through the fiber base material from penetrating into the polyurethane core. Certainly, it may be possible to prevent penetration into the interior to some extent by selecting the resin layer forming material, but the layer formed by the coating is insufficient in strength, and resin injection of usually about 0.2 to 2 MPa This is partly destroyed by the pressure of the time and the like, with the possibility that the injected resin penetrates into the core. Further, when the injected resin and the thin resin layer covering the polyurethane core are insufficiently bonded, there is a problem that a squeak noise is generated when the product is deflected by gravity.
[0007]
The present invention solves the above-mentioned problems of the prior art, prevents penetration into the core during resin impregnation and discoloration due to penetration spots, and prevents generation of squeak noise in the FRP molded body, thereby reducing weight. An object of the present invention is to provide an FRP with a built-in foam resin core excellent in both flexibility resistance and a method for producing the same.
[0008]
[Means for Solving the Problems]
In order to solve the above-described problems of the prior art, the foamed resin core-embedded FRP of the present invention has the surface of the foamed resin core covered with a nylon film, and the film is impregnated with a thermosetting resin. a foamed resin core built FRP fiber base ing is laminated on at least one surface of the nylon film, together with the normal temperature is a non-adhesive property, a resin expressing adhesive property by heating An adhesive layer is provided, and the adhesive layer is located on the foamed resin core side .
[0009]
In addition, the method for producing a foamed resin core-incorporated FRP according to the present invention covers the surface of the foamed resin core with a nylon film, covers the film with a fiber base material, and then sets it in a cavity of a molding machine. a method of manufacturing a foamed resin core built FRP which Ru is injected and curing the curable resin on at least one surface of the nylon film, along with the room temperature is non-adhesive properties, expressed adhesive property by heating An adhesive layer made of resin is provided, and the adhesive layer is disposed on the foamed resin core side .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0011]
The foamed resin core used in the FRP of the present invention is a foamed resin molded product that forms the core of the FRP of the present invention, and the molded product is a foam made of polyurethane, polystyrene, polyolefin, etc. It is manufactured by a general manufacturing method and has independent or open cells. The expansion ratio is not particularly limited, but it is preferably as high as possible in order to reduce the weight. Considering the balance with the strength of the molded body, it is preferable to set the expansion ratio to about 5 to 20 times.
[0012]
The foam molding method is not particularly limited, and can be molded by a conventionally known method. For example, in addition to carbon dioxide, freon, methylene dichloride, pentane, air, etc., a pyrolytic organic foaming agent can be applied. In particular, the production method by enclosing carbon dioxide gas by-produced by the reaction of a polyol such as polyurethane and isocyanate is preferable in that it can be easily and uniformly foamed. As such a molding method, a one-shot method or a prepolymer method is generally known. The core used in the present invention is preferably a semi-rigid or rigid foam.
[0013]
Incidentally, as described above, the present invention is characterized in that the surface of the foamed resin molded product is covered with a nylon film.
[0014]
Although it does not specifically limit as a nylon film, Arbitrary things, such as nylon 6, nylon 12, nylon 11,6-6 nylon, 6-10 nylon, can be used, These binary, ternary or more copolymer It may be. The melting point must withstand the curing temperature when impregnated with the thermosetting resin, and is usually preferably 150 ° C. or higher. The nylon film can be any of unstretched, uniaxially stretched and biaxially stretched. The thickness of the nylon film is preferably 3 μm or more and 75 μm or less. If the thickness is less than 3 μm, the strength may be insufficient and may be broken by the pressure during the coating process or thermosetting resin injection. If the thickness exceeds 75 μm, the core may not follow well and the surface condition of the product may deteriorate. The surface of the nylon film is preferably subjected to corona treatment in air, nitrogen, carbon dioxide, or the like in terms of adhesion to the thermosetting resin to be injected. The treatment may be single-sided or double-sided, but the side that contacts the thermosetting resin is preferably a corona-treated surface in terms of adhesiveness. By applying such a treatment, higher adhesion between the nylon film and the thermosetting resin can be expressed, and squeak noise when gravity is applied over FRP, which was a problem with conventional products, etc. Can be improved. The adhesive force between the nylon film and the impregnated fiber substrate is preferably 100 g / cm or more at 180 ° peeling, and a stronger adhesive force can be expressed by performing the above treatment. When the foamed resin molded product is coated with the nylon film, the purpose of the coating is to prevent the thermosetting resin from penetrating into the foamed resin molded product. Therefore, it is preferable to employ a coating method that can prevent the penetration. . As the coating method, you Ku is adhered to the core material in the process up to coating a fiber base material and a thermosetting resin. Specifically, a method is applied in which the adhesive film of the composite film in which a pressure-sensitive adhesive and an adhesive are laminated on at least one surface of the nylon film is coated on the core side . Incidentally, hot-melt adhesive for bonding by heating in a non-adhesive at ordinary temperature, have good workability when coating the core with a film. Heating may be selected according to the heat resistance of the core, but a lower temperature is preferable from the viewpoint of dimensional stability of the core, and in the case of a polyurethane foam core, it is preferably 150 ° C. or lower. Therefore, a hot melt adhesive having a melting point or softening point of 80 ° C. or higher and 140 ° C. or lower is preferable. Such hot-melt adhesives are not particularly limited, and for example, commercially available products such as polyester-based, acrylic-based, polyamide-based, polyolefin-based and copolymers thereof, modified products, and ionomers can be used. In the case of the nylon film of the present invention, a polyamide type or a modified polyolefin type is preferable. As the polyamide type, a copolymerized polyamide film (for example, heat bonding film type CF8000: manufactured by Toray Synthetic Co., Ltd.) is bonded to the nylon film. Alternatively, Admer NF series, HB series, LF series LB series, and VF series (manufactured by Mitsui Chemicals, Inc.), which are modified polyolefin adhesive polymers, are laminated with a nylon film by the extrusion laminating method. The thickness of the adhesive layer is not particularly limited, but it is 1 μm or more and 50 μm or less, preferably 3 μm or more and 30 μm or less, more preferably 5 μm or more and 20 μm or less from the viewpoint of fitting to the core material and maintaining the adhesion to the core. desirable. In addition, it is necessary to prevent the thermosetting resin from penetrating through the gaps in the nylon film when injecting the thermosetting resin, which will be described later, and the nylon film joint portion is repaired with an adhesive or adhesive tape. Is preferred. The base material of the adhesive tape is preferably a film having a melting point of 170 ° C. or higher in consideration of heat generated when the thermosetting resin is cured, and polyester, nylon, and the like are preferable. The adhesive layer preferably has heat resistance such as acrylic or silicone.
[0015]
The foamed resin molded article coated with a nylon film is covered with a fiber substrate impregnated with a thermosetting resin. The fiber base material to be used is not particularly limited, and heat-resistant and high-strength fibers such as glass fiber, carbon fiber, aramid fiber, ceramic fiber, and metal fiber are preferable. Particularly, a woven fabric made of carbon fiber has a balance between strength and lightness. It can be preferably used.
[0016]
Although it does not specifically limit as a thermosetting resin used here, Use of an epoxy resin, a melamine resin, a urea resin, an unsaturated polyester resin, a phenol resin, etc. is possible. In particular, an epoxy resin is preferable from the viewpoints of moldability, curability, adhesion to a nylon film, and the like. In order to thermally cure the epoxy resin, it is preferable to use a curing agent in combination, such as amines such as diethylenetriamine and triethylenetetramine, polyamide, phthalic anhydride, pyromellitic anhydride, pyromellitic anhydride-maleic anhydride mixture, hexa Acid anhydride systems such as hydrophthalic acid anhydride, dodecenyl succinic acid anhydride, chlorendic acid anhydride, and methyl nadic acid anhydride are preferred, and acid anhydride systems are particularly preferred in view of heat resistance. The coating with the fiber base impregnated with these resins may be a single layer, or two or more layers depending on the purpose and application. The strength of FRP can be improved by increasing the number of layers.
[0017]
Next, the manufacturing method of the FRP built-in core FRP of the present invention will be described.
[0018]
First, using the above-mentioned foamed resin molded product (core), nylon film laminated with adhesive and adhesive on at least one side, and fiber base material, “foamed resin molded product / nylon laminated with adhesive and adhesive on at least one side ” A composite laminate comprising the order of “film / fiber substrate” is manufactured. Next, in order to inject and cure the thermosetting resin, the composite molded body is set in a cavity of a predetermined mold, and the above-described thermosetting resin is injected from the end portion. As the injection pressure, it is necessary that the resin spread uniformly over the entire mold, and it can be arbitrarily set depending on the viscosity of the resin and the shape of the composite laminate, but the injection pressure is usually 0.2 to 2 MPa, preferably It is desirable that the pressure be in the range of 0.3 to 1 MPa, more preferably 0.3 to 0.7 MPa. The temperature of the mold may be set according to the type of the thermosetting resin to be used. For example, in the case of an epoxy resin, it is preferably 80 ° C. to 150 ° C. From the heat resistant dimensional stability of the foamed resin molded product. It is desirable to be as cold as possible. The heating time for thermosetting can be arbitrarily set depending on the type of the thermosetting resin, but it is usually preferably in the range of 3 minutes to 60 minutes.
[0019]
After the curing is completed, it is removed from the mold to obtain the FRP with a foamed resin core according to the present invention.
[0020]
The FRP with a built-in foamed resin core according to the present invention thus obtained has a non-adhesive adhesive surface at room temperature and is made of a resin that exhibits adhesiveness when heated. Since the layer is covered with the nylon film so as to be disposed on the core side, it is possible to prevent the thermosetting resin embedded in the outside from penetrating into the core and to adhere the thermosetting resin and the nylon film. Therefore, it is excellent in both the weight reduction and the durability of FRP, which are the original functions of the foam. For example, it can be applied to automobile body parts, bumpers, spoilers, etc. Can be.
[0021]
【Example】
The present invention will be described below with reference to examples.
[0022]
First, the method for measuring the characteristics of the core-incorporated FRP of the present invention and the method for evaluating the effects were as follows.
[0023]
[Characteristic measurement method and effect evaluation method]
(1) Adhesive force between thermosetting resin-impregnated fiber base material and nylon film FRP after completion of molding is disassembled, the thermosetting resin-impregnated fiber and nylon film composite part is taken out, and peeled 180 degrees with Tensilon type tensile tester The stress of was measured. The pulling speed was 200 mm / min.
(2) Appearance inspection of FRP molded body The appearance of FRP after completion of molding was visually observed to evaluate the color spots and surface shape.
(3) A cross section of the FRP after completion of the penetration molding of the thermosetting resin into the foam molding of the thermosetting resin was cut out, and the penetration state into the foamed portion of the foam surface was observed with a 100 × optical microscope.
(4) The amount of deformation in which a squeak noise was generated when the squeak noise molded body was bent was evaluated. The amount of deformation was set to 0 when no load was applied to the center of the molded body, and the pressing depth at which squeak noise was generated when the load was gradually deformed by applying a load was measured.
[0024]
" Reference Example 1"
Using a polyurethane molding core (width 250 mm x length 700 mm x thickness 30 mm) foamed and molded about 10 times, spray paste 55 (manufactured by Sumitomo 3M Co., Ltd.) is sprayed on the surface of this core, and at room temperature for 2 minutes Dried. Next, a biaxially stretched nylon film (emblem ONBC: manufactured by Unitika Co., Ltd.) having a thickness of 15 μm subjected to double-sided corona treatment was attached to the surface of the core. The end was wrapped with a nylon film so that the core was not exposed, and a polyester adhesive tape was attached. The molded nylon film was wrapped with a carbon fiber base fabric and then set in a mold of a resin injection molding machine heated to 80 ° C. A mixture of epoxy resin and phthalic anhydride was injected from the end with an injection pressure of 0.5 MPa, and then the temperature was raised to 120 ° C. and cured for 30 minutes. Then, it cooled to about 40 degreeC, the molding machine was opened, and the molded product was taken out from the metal mold | die. This molded product was very beautiful in appearance, did not penetrate the epoxy resin into the core, had high adhesiveness (1 kg / cm or more), and no squeak noise was generated even when deformed by 10 mm.
[0025]
"Comparative Example 1"
Next, an FRP molded body was prepared in the same manner except that the nylon film of Reference Example 1 was not used. The molded product was spotted in the color of the appearance, and dents were partially observed. Moreover, the penetration of the epoxy resin was observed inside the foam by cross-sectional observation.
[0026]
“Comparative Example 2”
A molded body was prepared in the same manner except that a biaxially stretched polypropylene film having a thickness of 15 μm was used instead of the nylon film of Reference Example 1. This molded article had poor adhesion between the epoxy resin-impregnated fiber base material and the polypropylene film (50 g / cm or less), and a squeak noise was generated with a deformation amount of less than 10 mm.
[0027]
“Comparative Example 3”
In place of the nylon film of Reference Example 1, toluene / ethyl acetate (70) obtained by adding 25 parts by weight of polyisocyanate (Coronate L: manufactured by Nippon Polyurethane Co., Ltd.) to 100 parts by weight of a polyester resin (Byron 200: manufactured by Toyobo Co., Ltd.) / 30% by weight), and a coating agent diluted to 25% by weight was prepared and applied to the surface of the foamed urethane core so that the thickness after drying was about 15 μm.
Drying was performed at 120 ° C. for 10 minutes. Except for this, a molded body was prepared in the same manner as in Reference Example 1.
From this cross-sectional observation, penetration of the epoxy resin into the foam was observed and cross-section defects on the appearance and concave defects on the surface were observed.
[0028]
"Example 1 "
Using a nylon thermal adhesive film CF8000 (manufactured by Toray Synthetic Co., Ltd.) 30 μm thick on one side of the nylon film of Reference Example 1 with a urethane adhesive, the thermal adhesive film side as the core side and Reference Example 1 Similarly, a foam core was coated. This was left for 5 minutes in a 120 ° C. hot air dryer to thermally bond the core and the film. Thereafter, a molded product was prepared in the same manner as in Reference Example 1. This molded article was excellent in adhesion (1 kg / cm or more) to the thermosetting resin-impregnated fiber base material and appearance, and no squeak noise was generated even with a deformation amount of 20 mm.
[0029]
"Example 2 "
A modified polyolefin adhesive polymer (Admer LF300: manufactured by Mitsui Chemicals, Inc.) having a thickness of 10 μm was laminated on one side of the nylon film of Reference Example 1 by the extrusion laminating method. The foam core was coated in the same manner as in Reference Example 1 with the adhesive polymer layer side of this film as the core side. This was left in a 130 ° C. hot air dryer for 10 minutes to thermally bond the core and the film.
Thereafter, a molded product was prepared in the same manner as in Reference Example 1. This molded article was excellent in adhesion (1 kg / cm or more) to the thermosetting resin-impregnated fiber base material and appearance, and no squeak noise was generated even with a deformation amount of 20 mm.
[0030]
【The invention's effect】
In the FRP with a foam resin core built-in, the core surface is non-adhesive at room temperature, and an adhesive layer made of a resin that exhibits adhesiveness when heated is disposed on the core side. Since it was covered with the nylon film as described above , the injected resin did not penetrate into the inner foam core, and therefore no discoloration occurred. Moreover, since the adhesiveness between the injection resin and the nylon film is high, it is possible to obtain an excellent foamed resin core built-in FRP in which no squeak noise is generated by bending.

Claims (3)

Surface of the foamed resin core is covered with a nylon film, the film via a fiber substrate thermosetting resin is impregnated a foamed resin core built FRP ing are stacked, the nylon film An adhesive layer made of a resin that is non-adhesive at room temperature and develops adhesive properties when heated is provided on at least one side of the adhesive layer, and the adhesive layer is positioned on the core side made of the foamed resin. FRP with a built-in foam resin core, characterized by And nylon film, 180 ° peel adhesion between the fiber substrate thermosetting resin is impregnated, it is 100 g / cm or more, a foam core built FRP of Claim 1. The surface of the foamed resin core is coated with a nylon film, the following coating film on a fiber base material, was set in a cavity of the molding machine, foamed resin core built FRP which Ru is injected and cured with a thermosetting resin A method for producing an adhesive layer, wherein at least one surface of the nylon film is provided with an adhesive layer made of a resin that is non-adhesive at room temperature and develops adhesive properties when heated, the adhesive layer Is disposed on the side of the foamed resin core.