JPH03193422A - Method for molding product having pattern on its surface - Google Patents

Abstract

PURPOSE:To form a pattern composed of granitelike particles having a large particle size by making the temp. of a mold at the time of the bonding of liquid dropletlike particles higher than that of the mold at the time of the charging of a curable composition. CONSTITUTION:The pipings 3 of a heating liquid medium are embedded in lower and upper molds 1a, 1b in the vicinity of the surfaces thereof and sprayable coating prepared by compounding a filler, pigment or the like with a thermosetting resin is diluted with a solvent and sprayed to the lower mold 1a by a spray gun 4 to bond liquid droplet like particles 2 to the lower mold 1a. When the sprayable coating is sprayed to the lower mold 1a heated to 70 deg.C or higher, the dilution solvent of the liquid droplet like particles 2 is immediately volatilized and the thin layer composed only of the sprayable coating is formed. Next, the pigment is altered to prepare sprayable coatings which are, in turn, successively sprayed to the surface of the lower mold 1a to bond two or more kinds of liquid droplet like particles 2 having different hues and particles sizes to the lower mold 1a. Thereafter, the temp. of the lower mold 1a is lowered to 50 deg.C to register the lower mold 1a with the upper mold 1b set to 50 deg.C and a casting resin is injected in the molds. By this method, no liquid running is generated even when large liquid droplet particles are bonded and a varified granitelike pattern having a smooth surface can be developed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates, for example, to a method for molding a molded article having a chromatic stone-like pattern.

[Prior art]

Fillers such as calcium carbonate, glass powder, and silica powder are blended with acrylic resin such as liquid unsaturated polyester resin or methyl methacrylate resin, dispersed, and placed in a mold under the action of heat and/or catalyst. It is a well-known technique to obtain a molded article by curing. This technique yields molded products with smooth surfaces and is used in the production of molded products such as wash basins, bathtubs, and table tops. In addition, in recent years there has been an increasing demand for molded products with beautiful surface finishes, and after spraying a mist of paint onto the mold surface using a spray gun to create a kiln-like pattern or satin-like pattern, the compounded resin is applied inside the mold. It has become possible to provide molded products having smooth and beautiful surface profiles by putting them into a mold and curing them under the action of heat and/or catalysts.

[Problem to be solved by the invention]

On the other hand, there is a strong demand for patterns with large grains such as colored stone, but it has been impossible to achieve this using conventional technology. Washbasins and bathtubs are three-dimensional objects, with vertical and sloping parts, and when droplets adhere to these parts, they move in the direction of gravity, causing so-called drips and creating unnatural patterns. The present invention was made in view of the above circumstances, and its purpose is to manufacture a molded product having a horizontal pattern of large-diameter particles such as a shaped stone. It is in.

[Means for Solving the Problems 1] The method of molding a molded article having a pattern on the surface of the present invention involves depositing droplet-like particles 2 on the surface of a mold 1 to form a horizontal pattern, and then forming a curable composition. A molding method in which a material is put into a mold 1 and cured to give a horizontal pattern to the surface of the molded product, in which a composition that can harden the temperature of the mold when droplet-shaped particles 2 are attached is put in. The above-mentioned problem is solved by this structure. Since a pattern is formed, this pattern is integrally transferred to the molded product, and a shaped stone-like horizontal pattern made of particles 2 with a large diameter is realized.The present invention will be described in detail below. The mold 1 is for molding a bathtub, and as shown in FIG. 1, it consists of a lower mold 1a and an upper mold 1b, and a liquid medium for heating is placed near the surfaces of the lower mold 1a and the upper mold 1b. A pipe 3 is buried therein. First, droplet-like particles 2 are attached to the lower mold 1a. This is done by adding a filler, a filler,
Spray paint mixed with pigments and the like is diluted with a solvent and sprayed with a spray gun 4, thereby causing droplet-like particles 2 to adhere to the lower mold 1a. Examples of the thermosetting resin include unsaturated polyester resin, acrylic resin such as methyl methacrylate resin, 7-enol resin, and area resin. Methyl methacrylate resin, which has excellent hot water resistance, is preferred for bathtubs. Examples of fillers include silica powder, glass powder, and calcium carbonate, among which silica powder, which has high strength, is preferred.As for pigments, acrylic pigments are preferred. For example, 30 parts by weight of methyl methacrylate resin, 70 parts by weight of silica powder, and 5 parts by weight of pigment are used. Prepare spray paint, dilute it with xylene and suspend it (viscosity 10 cp).
．． Spray pressure 0.2 with spray gun 4 of 5 srs
The droplet-shaped particles 2 are sprayed onto the lower mold 1a heated to 70° C. or higher at kg/c infusion 2. In this case, the droplet-shaped particles 2 became a thin layer of spray paint because the diluent immediately volatilized. When we measured their diameters, we found that there were quite a number of them with diameters of 21 or more. In this way, spray paint is sprayed by controlling the density, changing the pigment, and sequentially spraying spray paints with different lightness, tone, and hue onto the surface of the lower mold 1a, and spraying multiple types of spray paint with different tones and particle sizes. For example, the first
The third spray paint is the third lightest gray (L car = 34.89, A book = -0,02, B Kyo = -0,16)
, the second spray paint is the second lightest gray (L = 47.61.1* = 0.71, b* = 1.48
), the third spray paint is the lightest gray and seasoned (L books = 52.55.8 * = 2.06
．． 5*=3.07), the fourth spray paint is the darkest gray (Lkyo=27.36, car a=-0,60,
b*=-1,05). After this, the temperature of the lower mold 1a is lowered to 50"C, and
The upper mold 1b was set at a temperature of 0.degree. C., and the casting resin was poured into the mold. As the casting resin, a thermosetting resin such as an unsaturated polyester resin, an acrylic resin such as methyl methacrylate resin, a phenol resin, or an area resin mixed with a filler and, if desired, a pigment can be used. In this case, it is preferable to use the same resin as that of droplet particle 2.
The mold temperature was raised to 60-90°C and heated for about 30 minutes to harden under the action of a catalyst (peroxide), and the mold was removed to form a colored stone-like a ridge as shown in Figure 3. We have manufactured a bathtub with a smooth and beautiful surface. [Effect of the invention] In the present invention, since a pattern is formed by attaching droplet-like particles to the mold surface, this horizontal pattern is integrally transferred to the molded product, and the pattern is made up of particles with a large diameter. It is possible to embody the pattern on the granite side, and since the mold temperature when depositing the droplet-like particles is higher than the mold temperature when adding the curable composition, it is possible to create large droplet-like particles. Even when particles are attached, there is no liquid dripping, and even when the composition is cured, no deformation occurs, and the surface is smooth and various patterns can be created on the granite side. It is.

[Brief explanation of drawings]

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

Claims (2)

[Claims] (1) A molding method in which droplet-like particles are attached to the surface of a mold to form a pattern, and then a curable composition is poured into the mold and cured to form a pattern on the surface of the molded product. A method for molding a molded article having a pattern on its surface, characterized in that the temperature of the mold when the droplet-shaped particles are attached is higher than the temperature of the mold when the curable composition is charged. (2) The droplet-shaped particles include those with a particle size of 2 mm or more, and the surface temperature of the part of the mold to which the droplet-shaped particles are attached is set to 70° C. or higher. A method for molding a molded product having a pattern on the surface as described above.