JP2781628B2 - Molding method of molded article having pattern on surface - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a method for forming a molded article having a granite pattern, for example.

2. Description of the Related Art Fillers such as calcium carbonate, glass powder, and silica powder are mixed with an acrylic resin such as a liquid unsaturated polyester resin or a methyl methacrylate resin, dispersed and charged into a mold. It is a well-known technique to obtain molded articles by curing under the action of a catalyst. With this technique, molded articles having a smooth surface are obtained, and molded articles such as washbasins, bathtubs and table tops are manufactured. In recent years, there has been an increasing demand for molded products with beautiful surface finishes.After spraying paint into the mold surface with a spray gun to form a kiln-modulated or pear-skinned pattern, the compounded resin is placed in the mold. And cured under the action of heat and / or a catalyst to provide a molded article having a smooth and beautiful surface pattern (see FIG. 5).

[Problems to be solved by the invention]

On the other hand, there is a strong demand for a pattern having a large grain size such as granite, but this has not been possible with the conventional technology. It is a washbasin or bathtub is a three-dimensional object,
This is because there is a vertical portion or an inclined portion, and if a droplet adheres to this portion, it moves in the direction of gravity, causing so-called dripping, resulting in an unnatural pattern. The present invention has been made in view of the above circumstances, and an object of the present invention is to produce a molded article having a pattern with large particles such as granite.

[Means for Solving the Problems]

In the present invention, a spray gun is used to spray and attach droplet-shaped particles 2 different from spray paint to the surface of a mold 1 by a spray gun to form a pattern. The above-mentioned problem has been solved by this configuration. [Operation] Since a pattern is formed by adhering the droplet-shaped particles 2 to the surface of the mold 1, the pattern is integrally transferred to a molded product, and a granite-like pattern composed of the large-diameter particles 2 can be realized. Further, since the droplet-shaped particles 2 are sprayed on the surface of the mold 1 together with the spray paint by using a spray gun to form a pattern, the droplet-shaped particles together with the spray paint are sprayed with the spray gun. It sprays on the mold surface, not to mention the shade of spray paint,
The dispersion of the droplet-shaped particles can be controlled, and a pattern is drawn by the dispersion of the particles.For example, in a molding method in which the pattern is transferred to the inner surface of a molded article such as a bathtub, the degree of freedom of the pattern can be easily increased. You can increase it. Hereinafter, the present invention will be described in detail. The mold 1 is for forming a bathtub, and includes a lower mold 1a and an upper mold 1b as shown in FIG. 1, and a lower mold 1a and an upper mold 1b.
A pipe 3 of a liquid medium for heating is buried in the vicinity of the surface. First, the droplet-shaped particles 2 are attached to the lower mold 1a. this is,
As shown in FIG. 2, a spray paint in which a filler, a pigment and the like are mixed in a thermosetting resin is diluted with a solvent and sprayed by a spray gun 4 to attach the droplet-shaped particles 2 to the lower mold 1a. Examples of the thermosetting resin include an unsaturated polyester resin, an acrylic resin such as a methyl methacrylate resin, a phenol resin, and a urea resin. For bathtub use, methyl methacrylate resin having excellent hot water resistance is preferable. Examples of the filler include silica powder, glass powder, and calcium carbonate. Among them, silica powder having high strength is preferable. As the pigment, an organic pigment such as an acrylic pigment, an inorganic pigment such as titanium oxide or iron oxide, or a mixture thereof is used. For example, methyl methacrylate resin 30 parts by weight, silica powder 70
Parts by weight and 5 parts by weight of a pigment to prepare a spray paint. A spray paint diluted with xylene (viscosity: 10 cp) was sprayed with a spray gun 4 having a diameter of 2.5 mm to a spray pressure of 0.5 kg / cm ^2.
Is sprayed onto the lower mold 1a heated to 70 ° C. or more to adhere the droplet-shaped particles 2. In this case, the dilute solution of the droplet-shaped particles 2 was volatilized immediately and became a thin layer of only spray paint. When its diameter was measured, a considerable number of those having a diameter of 2 mm or more were present. In this way, the spray density of the spray paint was controlled to spray the lightness, color tone, and hue different from each other on the surface of the lower mold 1a. . As the casting resin, a resin obtained by blending a filler and, if desired, a pigment with a thermosetting resin such as an acrylic resin such as an unsaturated polyester resin or a methyl methacrylate resin, a phenol resin, or a urea resin can be used. In this case, it is preferable to use the same resin as the resin of the droplet particles 2. Next, the mixture was heated, cured, and released from the mold to produce a beautiful bathtub having a granite pattern as shown in FIGS. 3 and 4 and having a smooth surface.

【The invention's effect】

In the present invention, since a pattern is formed by adhering droplet-shaped particles to the surface of the mold, the pattern is integrally transferred to a molded product, and a granite-like pattern composed of particles having a large diameter is realized. It is possible to form a pattern by spraying droplet-shaped particles with a spray gun on the mold surface that are different from spray paint together with spray paint. The spray droplets are sprayed onto the mold surface with a spray gun, so that not only the density of the spray paint but also the dispersion of the droplets can be controlled and the pattern is drawn by the dispersion of the particles. For example, in a molding method for transferring this pattern to the inner surface of a molded article such as a bathtub, the degree of freedom of the pattern can be easily increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a mold according to the present invention, FIG. 2 is a perspective view showing one step in the above, FIGS. 3 and 4 are photographs showing the particle structure on the surface of a bathtub manufactured by the above.
FIG. 5 is a photograph showing the particle structure on the surface of a bathtub manufactured by a conventional method, wherein 1 is a mold and 2 is droplet-shaped particles.

Continuation of the front page (51) Int.Cl. ⁶ identification code FI // B29K 33:04 67:00 B29L 31:00 (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 39/10-39 / 12 B29C 39/22-39/24 B05D 5/06 B05D 1/34 B29K 67:00 B29K 33:04 B29L 31:00

Claims (2)

(57) [Claims] 1. A pattern is formed by spraying droplet-shaped particles other than spray paint together with spray paint on a mold surface by using a spray gun to form a pattern, and then pouring a curable composition into the mold. And curing the molded product. 2. The method according to claim 1, wherein the droplet-shaped particles include those having a particle diameter of 2 mm or more, and the surface temperature of a portion of the mold to which the droplet-shaped particles adhere is set to 70 ° C. or more. Item 1. A method for molding a molded article having a pattern on its surface according to Item 1.