JP3830113B2 - Fiber-reinforced plastic molded product and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fiber reinforced plastic (FRP = Fiber Reinforced Plastic) molded product molded by SMC (Seet molding compound), BMC (Bulk molding compound), and the like, and a method for producing the same.
[0002]
[Problems to be solved by the invention]
Conventionally, as a method for producing a patterned fiber reinforced plastic (FRP) molded product, titanium paper, nonwoven fabric, cloth, impregnated paper, etc. are simultaneously molded and integrated (for example, Japanese Patent Laid-Open No. S48-12876, Japanese Patent Laid-Open No. In this method, (1) clear printing is not possible, (2) tearing is likely to occur, (3) the shape is limited and the shape is limited. (4) Adhesion with a physical anchoring effect has a drawback that there is a large variation in adhesion due to molding conditions such as temperature and pressure.
[0003]
Further, as disclosed in JP-A-7-60911, a nonwoven fabric is lined with a two-component curable urethane resin adhesive on a plastic sheet having a printing melting temperature equal to or higher than the FRP molding temperature, and the sheet is molded. In some cases, a method of integrating them is also employed, but this method has a problem that the lining process is complicated and the quality of the nonwoven fabric is unstable due to uneven formation and the cost is high.
[0004]
As another method, as disclosed in JP-A-56-72930, etc., it has good adhesion to the SMC resin, that is, it melts or softens at the temperature during SMC molding or swells with SMC components. There is also known a method of integrating a plastic sheet or a decorative sheet using printing ink that is melted in the process at the time of molding. However, in this method, the printing layer is washed away by heat at the time of thermosetting of SMC and stress at the time of flow. There is a problem that the defect comes out.
[0005]
The present invention has been made in view of the above-described problems, and the object of the present invention is to provide flexibility and strength at the time of heating and pressurization, high moldability, and good molding properties. An object of the present invention is to provide a fiber-reinforced plastic molded article that has good adhesion, can be printed clearly and delicately, and a method for producing the same.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the fiber-reinforced plastic molded product of the present invention is formed by using ABS (acrylonitrile / butadiene / styrene copolymer) on the surface of a molded product comprising a cured product of a thermosetting resin reinforced with a fibrous reinforcing material. ) A resin layer and a biaxially stretched polyester resin layer on the surface thereof are sequentially laminated and integrated in this order.
[0007]
The above-mentioned fiber reinforced plastic molded article prepares a decorative sheet in which a biaxially stretched polyester resin layer and an ABS resin layer are sequentially laminated, and the ABS resin layer of the decorative sheet (hereinafter also simply referred to as “sheet”). It is manufactured by stacking FRP raw materials (or intermediates) such as SMC or BMC so as to be in contact with the side, and heating and pressing in a mold to integrate them.
[0008]
As described above, in the present invention, by using a biaxially stretched polyester resin layer, the sheet itself is not deformed, flowed, broken, etc., even with respect to heat due to molding or stress due to fluidity of SMC. The backed ABS resin layer protects the printed pattern layer from the flow of SMC and styrene monomer, imparts appropriate moldability to the sheet, and is compatible with FRP and exhibits strong adhesion. it can.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
As the biaxially stretched polyester resin layer, a polyester sheet formed in advance is used. This sheet is excellent in transparency, tensile strength, heat resistance, dimensional stability, printability, stain resistance, solvent resistance, and the like. Although a thickness of 10 to 200 μm can be used, it is desirably about 20 to 100 μm. If it is too thin, the strength and depth will decrease, and if it is too thick, it is not good in terms of printability, formability and cost. Typical examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, ethylene terephthalate isophthalate copolymer, polyethylene naphthalate, and polyarylate.
[0010]
As the ABS (acrylonitrile / butadiene / styrene copolymer) resin layer, those generally produced as sheets are used. This is relatively inexpensive in terms of cost. The styrene monomer in FRP (mainly unsaturated polyester resin) can be fused and adhered by hot pressure at the time of molding, and can be bonded in a compatible manner. At the same time, the styrene monomer in the FRP reaches the decoration layer and blocks the decoration layer from flowing. Although a thickness of 10 to 500 μm can be used, it is desirably about 50 to 200 μm. If it is too thin, it will melt during molding and the printed layer cannot be protected. If it is too thick, the warping of the molded product will increase and the cost will increase. The moldability of the entire decorative sheet is improved by moderate thermal deformation of the ABS resin layer.
[0011]
The biaxially stretched polyester resin layer has an ultraviolet absorber such as benzotriazole, benzophenone, fine particle cerium oxide, a hindered amine radical scavenger, etc. in the layer in order to improve the weather resistance of the FRP directly under the layer itself or as necessary. A light stabilizer may be added. The addition amount of both the ultraviolet absorber and the light stabilizer is about 0.1 to 5% by weight. Further, in the biaxially stretched polyester resin layer, a colorant such as a dye or a pigment may be added as necessary within a range not losing transparency.
[0012]
The thermosetting resin that is a component of FRP includes unsaturated polyester resin, vinyl ester resin, diallyl phthalate resin, thermosetting acrylic resin, melamine resin, guanamine resin, phenol resin, epoxy resin, two-component curable polyurethane resin, etc. Is mentioned.
[0013]
In order to make a molded product from these thermosetting resins, first, a monomer or prepolymer (including oligomers) of these resins plus a crosslinking agent, a polymerization initiator, or a reaction promoting catalyst is used. An uncured composition is prepared by adding a fibrous reinforcing material such as fiber, woven fabric, and non-woven fabric and various other additives as required. As the raw material or intermediate form of this uncured composition, that is, FRP, there is, for example, the form of SMC or BMC.
[0014]
Then, as shown in FIG. 1 (a), the decorative sheet 1 and the uncured composition 2 are overlapped and inserted into a predetermined mold (upper mold 11 and lower mold 12), and FIG. 1 (b). The mold is closed, heated and pressurized as shown in FIG. 2 to crosslink or polymerize the uncured composition 2 to cure it, thereby forming a solid molded article 3 and simultaneously adhering the decorative sheet 1 to the surface of the molded article 3. The decorative material as shown in FIG. 1 (c) is obtained. At that time, unreacted components (monomers, etc.) in the FRP raw material or the intermediate penetrate into the ABS resin in the decorative sheet 1 to enhance the adhesive force between the decorative sheet 1 and the molded product 3. To do.
[0015]
The SMC, which is a typical form of the uncured composition, will be described in detail. The material of the SMC is kneaded fiber reinforcing agent such as glass fiber, carbon fiber, asbestos, potassium titanate, catalyst, filler, release agent, etc. Made of a thermosetting resin. The thermosetting resin used is typically a prepolymer of an unsaturated polyester resin. As the fiber reinforcing agent, short glass fibers are usually used. The glass fiber content is usually 10 to 70% by weight. As the filler, powder of calcium carbonate, barium sulfate, aluminum hydroxide or the like is used. As the mold release agent, zinc stearate or the like is used. In addition, reaction diluents such as styrene monomer and polyfunctional acrylate (or methacrylate) monomer, cross-linking agents such as isocyanate and amine, benzoyl peroxide, methyl ethyl ketone peroxide, t-butyl perpenzoate, organic as required A polymerization initiator (curing catalyst) such as sulfonate, a curing accelerating catalyst such as cobalt naphthenate or manganese naphthenate, a colorant such as titanium dioxide, carbon black, or a petiole is added.
[0016]
The decorative treatment applied to the sheet on which the biaxially stretched polyester resin layer and the ABS resin layer are laminated includes a coloring agent such as a dye or a pigment on one or both of the biaxially stretched polyester resin layer and the ABS resin layer in the sheet. It can also be applied by kneading, but in general, it is performed by gravure printing, silk screen printing, etc., and the printed pattern is a wood grain pattern, stone pattern, cloth pattern, letters, geometric pattern, full face pattern, etc. . When it is necessary to conceal the FRP molded product, an entire surface solid layer is provided on the FRP (SMC) side of the pattern, and a pigment having high concealability such as titanium dioxide and carbon black is added to the entire surface solid layer. Printing ink consists of various pigments (or dyes) and a binder resin. The binder is appropriately selected from two-component curable urethane resins, acrylic resins, polyester resins, vinyl chloride-vinyl acetate copolymers, cellulose resins, polyvinyl butyral resins, and the like. Moreover, you may form metal thin films, such as aluminum and chromium, by a vapor deposition, sputtering, etc. as a decoration process. In this case, the metal thin film may be the entire surface or a pattern. The printed pattern layer or the metal thin film applied as the decoration treatment may be applied to the surface of the ABS resin layer or the back surface (thermosetting resin side) as long as the entire decoration sheet layer is transparent. If necessary, the surface of the resin layer (sheet) on the printing side may be subjected to easy adhesion treatment such as corona discharge treatment, plasma treatment, and easy adhesion primer coating.
[0017]
If necessary, a protective layer made of a synthetic resin may be formed on the surface of the decorative sheet. The protective layer is selected so as to be transparent (colorless or colored) so that the decorative layer can be seen through. As the resin, a thermoplastic resin is used when emphasizing moldability, and a curable resin such as a thermosetting resin or ionizing radiation curable resin when emphasizing physical properties such as scratch resistance and chemical resistance of the surface. Is used. The thickness may be appropriately determined according to the required performance, but is usually about 1 to 100 μm. The above-mentioned resin is used as the thermoplastic resin. However, when using for a protective layer, it is not necessary to add a reactive component. Representative examples of thermosetting resins include two-component curable polyurethane resins, epoxy resins, and unsaturated polyester resins. Examples of ionizing radiation-curable resins include polyfunctional unsaturated (meth) acrylate monomers or prepolymers. Is. In general, ultraviolet rays or electron beams are used as ionizing radiation. In order to improve the weather resistance, an ultraviolet absorber and / or a light stabilizer as described above are added to the protective layer.
[0018]
Applications of the fiber-reinforced plastic molded product of the present invention include building materials such as interior walls such as walls, floors, and ceilings, housing equipment such as bathtubs, washstands, and kitchen appliances, furniture such as window frames and doors, vehicles, and ships. Vehicle interior materials, containers, cabinets for home appliances, and the like.
[0019]
【Example】
(Example)
A decorative sheet was prepared as follows. In other words, a biaxially stretched polyethylene terephthalate sheet (Diafoil “T-100”, 25 μm thick) and a two-part curable polyurethane resin composed of hexamethylene diisocyanate and acrylic polyol as a binder (Zinctech's “NL-” After printing a marble marble stone pattern by gravure printing using ALFA and forming a decorative layer, a two-part curable polyurethane resin adhesive ("E-295" manufactured by Dainichi Seika Kogyo Co., Ltd.) ) Was used to dry laminate a colored ABS sheet (“A402” manufactured by Sanpo Resin Co., Ltd., 30 μm thick).
[0020]
This decorative sheet is overlapped so that the ABS surface is in contact with SMC (made by Takeda Pharmaceutical Co., Ltd.) made of unsaturated polyester resin and glass fiber, and these are placed in a molding die. The SMC was cured by heating and pressing at 100 kgf / cm ² for 5 minutes, and both were bonded and integrated. As a result, a bathroom wall panel with high design was obtained. There were no defects such as tearing of the decorative sheet, and the adhesiveness and formability of the molded product and the decorative sheet were also good. Further, when the decorative sheet was peeled off, it did not peel off at the interface between the sheet and the molded body.
[0021]
(Comparative Example 1)
A decorative sheet in which a pattern printing similar to that of the example was applied to DAP-impregnated paper (titanium paper having a basis weight of 100 g / m ² impregnated with diallyl phthalate prepolymer) was produced, and Example 1 was made using this decorative sheet. The same molding as SMC was performed. In the molded product, the decorative sheet was torn and the pattern distortion partially occurred.
[0022]
(Comparative Example 2)
Polymethylmethacrylate acrylic resin sheet / printing layer similar to the example / semi-rigid polyvinyl chloride resin (plasticizer DOP: 20 parts by weight) A colored base sheet is prepared, and this decorative sheet is used. In the same manner as in Example 1, it was molded simultaneously with SMC. In the molded product, the sheet melted, torn, wrinkled, and pattern flow occurred. Also, the adhesion between the SMC and the sheet was not sufficient.
[0023]
【The invention's effect】
As described above, according to the present invention, there is no defect such as tearing on the appearance, wrinkles, pattern flow, pattern distortion, etc., and a design that can be clearly expressed by printing, and a product firmly bonded to FRP can be obtained. Obtainable.
[Brief description of the drawings]
FIG. 1 is a process diagram for explaining a manufacturing procedure of a fiber-reinforced plastic molded article.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Decorative sheet 2 Uncured composition 3 Molded article 11 Upper mold 12 Lower mold

Claims (2)

An ABS resin layer is formed on the surface of a molded article made of a thermosetting resin reinforced with a fibrous reinforcing material, and a biaxially stretched polyester resin layer is laminated and integrated in this order on the surface. Fiber reinforced plastic molded product. Prepare a decorative sheet in which a biaxially stretched polyester resin layer and an ABS resin layer are sequentially laminated, and superimpose SMC or BMC so as to be in contact with the ABS resin layer side of the decorative sheet. A method for producing a fiber-reinforced plastic molded product characterized by integrating the above.

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