JPH04201421A - Manufacture of in-mold decorated article - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a molded article, and particularly to a method suitable for decorating a fiber-reinforced plastic (FRP) molded article.

[Conventional technology]

Because FRP molded products are lightweight and strong, they are used in a wide range of fields, including helmets, chairs, septic tanks, tanks, bathtubs and other housing-related equipment, and automobile parts. FRP molded products have poor surface smoothness, and sometimes reinforcing fibers are exposed on the surface, so if they are to be used as a surface material or housing, they must be painted.
However, when painting by painting, the types of paints that can be used are limited due to the poor adhesion of the paint, and it is not possible to efficiently impart a desired pattern to the molded product. There is also the issue of the work environment. Layering decorative sheets has been used as a method for painting molded products, but this method has limitations on the materials that can be used for the decorative sheets, does not necessarily provide the desired surface properties, and is difficult to shape. It cannot be applied to complex molded products. Furthermore, if a decorative sheet is to be laminated onto a large object, wrinkles and blisters are likely to occur, making it impractical, and large heating equipment is required. So-called decoration is a method of manufacturing molded products, in which a decorative sheet for decoration is placed inside an injection mold, and the decoration is applied at the same time as plastic injection molding.
Obtaining large molded products by injection molding requires large equipment and expensive molds, which is economically disadvantageous. Moreover,
There are also limits to the length and amount of fibers added to improve strength. The applicant has already proposed a method for manufacturing a molded article with decoration that solves this problem, in which decoration is carried out simultaneously with compression molding of thermoplasticized plastic (Japanese Patent Application No. 130476/1999). SMC (
Sheet Moldina Compound)
Although methods such as the molding method, the cold press method, and the preform-matted die method are known, a method suitable for painting products made by these molding techniques has not yet been developed. [Problems to be Solved by the Invention] An object of the present invention is to provide a method useful for producing molded articles by painting FRP by compression molding, for which there has been no suitable method in the past.

[Means to solve the problem]

The method for manufacturing the painted molded product of the present invention will be explained with reference to the drawings. Basically, as shown in FIG. 1 or 2, an upper mold (1A) and a lower mold (1B) are manufactured. A heated painting sheet (3) is placed on the upper mold and (or) lower mold surface of the compression molding mold, and vacuum and/or pressure molding (example shown) is performed as shown in Figure 2. (vacuum forming)
Then, as shown in Figure 3, the fiber reinforcement material and the curable resin prepolymer are placed on the lower mold, and the upper mold is lowered and the lower mold is raised. Then, as shown in FIG. 4, the mold is tightened and compression molding is performed to obtain an FRP molded product with an integrated decorative sheet as shown in FIG. 5. There are no particular restrictions on the means for heating the sheet for painting, but a heat differential with a far-infrared heater or an electric heater embedded therein is preferred. The preforming of the sheet for decoration is carried out using a compression molding mold (1A) as shown in FIG. This method is convenient because it allows the preform to be moved to the next step without moving it. For preforming, a vacuum forming method, a compression molding method, or a vacuum pressure forming method is preferable, and in that case, a vacuum hole (11) or an air handling hole may be provided in the compression molding mold (1A, 1B>). In either case, it is convenient to use a female mold for this preforming. However, depending on the surface to be painted, it may be necessary to use a male mold. It is a good idea to create a bank around the part that will become the cavity, with a height equal to or higher than the highest surface of the mold. It is preferable to detect the mark and place the decorative sheet at a predetermined position on the mold, as this ensures synchronization between the pattern on the decorative sheet and the shape of the molded product. One of the compression molding methods for FRP is the SMC method, and in this method, as shown in Figure 3, SMC (4), which is an aggregate of chopped Ii fiber reinforcement impregnated with prepolymer from both sides, is compressed. Place it on the lower mold (1B) of the molding die, tighten the mold as shown in Figure 4, and apply heat and pressure to obtain an FRP molded product. This is a preform-metal die method in which a preform molded into the shape of a prepolymer and a prepolymer are placed on a lower mold, the mold is closed, and the FRP molded product is obtained by heating and pressing. One example is the cold press method, in which a preform or continuous strand mat of fiber reinforcing material and a prepolymer are supplied to a mold, the mold is tightened, and pressure is applied to obtain an FRP molded product.Used as a material for molding. The thermosetting resin may be appropriately selected depending on the molding method, and examples thereof include phenol resin, epoxy resin, diallyl phthalate resin, unsaturated polyester resin, polyimide resin, and melamine resin.These prepolymers In addition, thickeners, fillers,
The fact that it may be used with optional additives such as catalysts is
Needless to say. Common fiber reinforcing materials include glass fiber, carbon fiber, and metal fiber. Depending on the material, natural fibers or synthetic fibers can also be used. Type and content of fiber reinforcement,
The length and form (for example, whether it is a fiber or a cloth) may be determined depending on the molding method and the purpose of the molded product. There are two types of decorative sheets: one is a decorative sheet that is integrated with the plastic to be molded and forms the surface of the molded product, and the other is a transfer sheet that peels off the surface to reveal the layer underneath. Either one may be used in the present invention. The decorative sheet and transfer sheet can be made of any material as long as it is easily deformed according to the mold. An example of a decorative sheet is one in which a decorative layer and a surface protective layer are provided on a plastic base sheet by printing a pattern and vapor depositing a metal. The material for the decorative sheet, especially its base sheet, is selected in consideration of the shape of the molded product and the type of plastic to be integrated. For example, the material may be selected from vinyl resins, styrene resins, ABS resins, acrylic resins, polyolefins, cellulose derivatives, polyamides, and the like. Although the thickness depends on the purpose and shape of the molded product, it is usually about 20 to 1000 μm. Suitable materials for the protective layer include acrylic resins, fluororesins, and mixtures and laminates thereof, which have excellent weather resistance and other surface properties. As the fluororesin, a coextruded laminate sheet of polyvinylidene fluoride and polymethyl methacrylate or polyvinyl chloride, which has excellent adhesiveness with other resins, is placed with the polyvinylidene fluoride side on the surface that will be in contact with the mold. It is preferable to use When you want a molded product to have wear resistance and scratch resistance, use a decorative sheet with a protective layer of semi-cured or touch-dry, uncured ionizing radiation-curable resin and integrate it with the molded product. Then, a method may be adopted in which the resin layer is cured by irradiating with ionizing radiation. In addition, there are decorative sheets with embossed surfaces and bead pigments added to the protective layer to make them matte.
It is also possible to use a base sheet in which a decorative layer is provided on a part of the base sheet. If necessary, apply adhesive to the back of the decorative sheet. When using a transfer sheet, as with the decorative sheet, any material may be used as long as it has good moldability. The material for the transfer mount is preferably polyethylene terephthalate/isophthalate copolymer, polybutylene terephthalate, nylon/polyvinyl chloride laminate, etc., especially in terms of moldability into a three-dimensional shape, and the thickness thereof is as follows: Usually about 6 to 100 μm is appropriate. The transfer sheet generally has a decorative layer and an adhesive layer on a transfer mount, and preferably has a release layer between the transfer mount and the decorative layer, which becomes a protective layer after transfer.

[Function 1] In the manufacturing method of the present invention, decoration can be applied at the same time as molding by placing a decoration sheet in a compression mold and compression molding the plastic. Thereby, FRP with desired appearance and surface properties
The painting is realized by molded products. [Example 1] A colored polyvinyl chloride (PVC) sheet "R type" (manufactured by Riken Vinyl) with a thickness of 0.2M was used as a base sheet,
A pattern is gravure printed on one side using the PVC ink "Ka x" (manufactured by Showa Ink Kogyosho), and a transparent PVC sheet (same) with a thickness of 0.2 mm is laminated on top of it, and the other side of the base sheet is A decorative sheet whose surface was coated with a urethane adhesive (manufactured by DIC) was placed on the upper mold surface of a compression molding mold so that the adhesive side faced the side opposite to the surface in contact with the mold. This decorative sheet was exposed to a heating chamber with a heater embedded in it, heated for 5 seconds at a temperature of 130° C., and then vacuum-pressure molded using a compression mold. A continuous strand mat of glass fibers (fiber content 40% by weight) and an unsaturated polyester resin were fed onto the lower mold of a compression mold. The upper mold was lowered and held at a pressure of 1 OKtj/ctA at room temperature for 15 minutes to obtain a molded article with FRP decoration. [Example 2] 70 parts of bisphenol resin, 30 parts of solvent, and Ca C
A aged SMC (Mli fiber content: 30% by weight) was prepared by impregnating an aggregate of glass fibers with a length of 20 #tllf with a plastic compound consisting of 120 parts of O3 powder. A transparent PVC sheet (same as above) with a thickness of 0.5 m was used as the base sheet, and a release agent rBH-3 (manufactured by Showa Ink Industries) was roll coated on it, and printing ink rGGJ (manufactured by Showa Ink Industries) was applied. Print the pattern with the heat seal material
A transfer sheet roll-coated with NcJ (manufactured by Showa Ink Industries) was heated to 100°C using a far-infrared heater.
It was heated for 0 seconds to soften it. The converted sheet was placed on the surface of the upper mold of a compression mold so that the base sheet side was in contact with the mold, and preformed. The above SMC was placed on the lower mold, the mold was closed, and the mold was heated and pressed for 10 minutes at a temperature of 150° C. and a pressure of 1100 N/crA to obtain a molded product integrated with the transfer sheet. The base sheet was peeled off from the molded product, and a two-component curable urethane resin paint was roughly applied on the surface of the transferred pattern to obtain an FRP molded product having a pattern on the surface. [Example 3] A helmet preform containing 40% by weight of glass fiber was prepared. A 0.5m thick acrylic resin sheet is used as the base sheet, and a decorative sheet is printed on it with a printing ink called "KaXJ" (manufactured by Showa Ink Kogyosho) and coated with adhesive.
It was placed on the upper mold surface of a compression molding mold so that the □ base material sheet side was in contact with the mold. This decorative sheet was heated on a heating plate with a surface temperature of 140℃ for 20 minutes.
It was softened by applying it for a second, and then preformed using a vacuum forming method. At the same time, the preform was placed on the lower die of the compression molding die, and the unsaturated polyester resin was supplied thereon. The mold was tightened and compression molded at a pressure of 500 Kg/CIt to obtain a helmet with a pattern on the surface. [Effects of the Invention] According to the method of the present invention, FRP having a desired beautiful appearance can be produced.
Painted parts can be easily manufactured. Since the surface of the molded product is covered with a painting sheet, there is no problem of exposed fibers.

[Brief explanation of the drawing]

Figures 1 to 4 are diagrams for explaining the present invention in detail. SMC in mold
FIG. 4 is a schematic cross-sectional view showing the place where the material is placed, and FIG. 4 shows the place where compression molding is being performed. FIG. 5 is a partially sectional side view of the FRP molded product manufactured in this manner. 1A, 1B... Mold 11... Vacuum hole 3.
・・Painting sheet 4・SMC5・F
RP Patent Applicant Dai Nippon Printing Co., Ltd. Agent Patent Attorney Suga So Otsutsu 1111 Figure 3 Figure 4

Claims (12)

[Claims] (1) A heated decorative sheet is placed on the surface of the upper mold and/or lower mold of a compression molding mold consisting of an upper mold and a lower mold, and vacuum and/or pressure molding is performed to create a pattern. The sheet for decoration is preformed, then fiber reinforcing material and a curable resin prepolymer are placed on the lower mold, the mold is tightened, and compression molding is performed to create an FR in which the sheet for decoration is integrated.
A method for manufacturing a decorated molded product, which comprises obtaining a P molded product. (2) The manufacturing method according to claim 1, wherein the heating of the decorative sheet is carried out by irradiation with heat rays from a far-infrared heater or by contact with a heating plate in which an electric heater is embedded. (3) Place positioning marks on the painting sheet,
3. The manufacturing method according to claim 1, wherein the mark is detected by a sensor provided in the compression molding machine, and the decorating sheet is placed at a predetermined position on the mold. (4) The manufacturing method according to any one of claims 1 to 3, wherein the compression molding method is an SMC method in which SMC is placed on a lower mold. (5) The manufacturing method according to any one of claims 1 to 3, wherein the compression molding method is a cold press method in which a preform of fiber reinforcement material or a continuous strand mat is placed on a lower mold together with a prepolymer. (6) The manufacturing method according to any one of claims 1 to 3, wherein the plastic compression molding method is a preform-matched metal die method in which a preform of fiber reinforcing material and curable resin is placed on a lower mold. (7) The manufacturing method according to any one of claims 1 to 6, wherein the decorative sheet is a decorative sheet in which a decorative layer and/or a surface protective layer are provided on a plastic base sheet. (8) The surface protective layer of the decorative sheet is an uncured ionizing radiation-curable resin layer that is semi-cured or dry to the touch, and the plastic molded product in which the decorative sheet is integrated is irradiated with ionizing radiation to obtain the above ionizing radiation. The manufacturing method according to claim 7, including the step of curing the curable resin layer. (9) The manufacturing method according to claim 7, wherein the surface protective layer of the decorative sheet is a matte layer containing bead pigments. (10) The manufacturing method according to claim 7, wherein the decorative layer of the decorative sheet includes a vapor-deposited metal layer. (11) The manufacturing method according to any one of claims 1 to 7, which is carried out using a decorative sheet coated with an adhesive. (12) The manufacturing method according to any one of claims 1 to 11, including the steps of using a transfer sheet as a decorating sheet, integrating the transfer sheet, and peeling the transfer mount from the plastic molded product.