JPS6196000A - Manufacture of artificial ivory - 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] This invention relates to a method for manufacturing artificial ivory.

[Conventional technology]

Ivory varies in size and quality depending on the species and habitat, but generally the outside is dark and the inside is white or cream-colored and has a wood grain. This wood grain has a fineness and density, forming beautiful striped patterns (waxy content, transparency, yellowing, elasticity, flexibility,
Ivory is highly valued as a carving material due to its workability and has been prized in the fields of ivory crafts and ivory crafts since ancient times. However, in recent years, the harvesting of live ivory has been prohibited by law and is subject to quantitative restrictions, so the tusks of animals other than elephants, such as hippopotamuses, tusks, and walruses, are also sometimes called ivory. Additionally, there are a large number of fossilized mammoth tusks found in Siberia, Alaska, etc., but these are too dry and break easily (their value is low. The standard for ivory is usually those with a grain weight of 50 pounds or more). Large size (task), small size (task) less than 50 pounds
Then, cut off one fang and make the point (tip),
It is divided into center (middle part), hollow (root part), etc., and is said to be of good quality if it is hard and has no mesh pattern on its cross section, and is classified into approximately 13M classes. In Japan, high-quality products are made into Japanese musical instruments, seals, etc., and soft products are used for billiard balls, piano keys, etc.

[Problem that the invention seeks to solve]

Due to legal regulations, natural ivory is becoming increasingly difficult to produce and the price is rising, so substitutes for natural ivory are already widely used. Conventional ivory substitutes are mainly coarse bone powder obtained at slaughterhouses, etc., pressure-molded with a binder, or exposed cow and horse tibia bones, but both have the grain pattern unique to ivory. It is quite different from natural ivory in that it has no ivory, its specific gravity is not taken into account, and even though it is hard, it is easily damaged. The technical object of the present invention is to eliminate the drawbacks of conventional artificial ivory.

[Means to solve the problem]

In order to solve the above-mentioned problems, this invention has developed an elastomer mold (female mold) formed from a model carved with wood grains as a master mold (male mold), fillers, colorants, hardeners, and other additives. A synthetic resin composition suitably blended with the above composition is injected and solidified, and then released from the mold, and a resin composition having at least a different color (hue, saturation, brightness, etc.) from the composition is injected into the recessed part of the obtained molded body. The purpose of the present invention is to provide a method for manufacturing artificial ivory, which is characterized by coating the ivory until the recesses are completely filled, and polishing the ivory after solidifying to finish the surface.The details will be described below.

First, as the first step of the present invention, a model having the same shape as the desired shape or having a slightly thicker shape is produced. The material of this model is not particularly limited, but from the point of view of price, workability, etc.
Wooden molds (for example, cypress, cedar, teak,
A molded body made of mahogany (sometimes coated with wax or lacquer to increase its moisture resistance) or a so-called plaster mold made by kneading a hydraulic material such as plaster or cement with water and solidifying it may be convenient. Next, thin grooves are carved into this model to resemble the grain of ivory. The depth of the groove at this time is preferably about 2 to 5 mm, taking into account the cutting allowance in the final process.

Next, in the second step, the model with the wood grain carved in the first step is used as a prototype (male model), and an elastomer such as synthetic rubber, elastic plastic, etc.
A layer of polymer (monomer) or initial polymer (prepolymer) is applied by coating, dipping, etc., and this layer is further polymerized and crosslinked by heating, irradiation, exposure, etc. to form an elastomer female mold. Create. Here, the elastomer has heat resistance that allows the resin composition to be cast in the next step to withstand the reaction heat generated during the curing reaction process or the heat of the thermoplastic resin in the molten state, as well as chemical resistance and mold release/mold resistance. Although there are no particular limitations on the material as long as it also has appropriate elasticity, silicone rubber is one of the most preferred examples. In addition, even if such elastomers contain polymerization catalysts (or polymerization initiators), polymerization or crosslinking accelerators, auxiliary agents thereof, inorganic fillers, etc., they do not interfere with this invention. isn't it.

Once the elastomer female mold has been produced in this manner, the third step begins, and the synthetic resin composition injected into the female mold in this step is separately prepared in the following manner. In other words, the main synthetic resin may be thermoplastic, thermosetting, reaction curable, electron beam curable, etc., as long as it is a polymer color, colorless, or white, but depending on workability, economy, etc. Naturally, thermal properties, hardness, elasticity, specific gravity, and other properties differ depending on the type of synthetic resin, so in addition to inorganic fillers, colorants (inorganic or organic pigments), curing agents (crosslinking agents) ), etc., to determine the blending ratio of the composition so as to obtain a molded article that approximates the properties of ivory. Here, examples of inorganic fillers include aluminum hydroxide, calcium carbonate, chalk powder, and titanium oxide, although some of them exhibit a coloring effect. When injecting the synthetic resin composition prepared in this manner into the female mold in a fluid state, it is necessary to take care not to create cavities in the molded product due to the inclusion of air, but it is necessary to adjust the specific gravity. For this purpose, there is a method of adding a foaming agent to a synthetic resin composition and curing it as a foam structure consisting of fine cells, or a method of applying a fluid synthetic resin composition to the inner wall of a female mold using centrifugal force. It is also possible to adopt a method such as curing without adhering to each other and making the shaft core part hollow.

In the third step, a synthetic resin composition is injected into the female mold made of elastomer, and when the composition has finished curing, the molded article in the female mold is taken out (fourth step). At this time, the female mold has a moderate amount of elasticity, so it is easy to release from the mold, or if it is a female mold or one with a deep taper (slope when cutting), it will be even easier to release the mold. .

The molded body taken out here has exactly the same shape as the original male mold with narrow grooves produced in the first step.

Next, a synthetic resin composition that is different from the synthetic resin composition in terms of at least color (hue, saturation, brightness, etc.) and that is suitable for expressing the grain of ivory is added to the narrow grooves of this molded body (for example, If you apply a composition containing a coloring agent, etc., to the extent that it completely fills the grooves while it is still fluid, and then polish the surface of the molded product after hardening, it will look like natural ivory. It is possible to produce artificial ivory that is extremely similar in properties such as hardness, elasticity, and specific gravity.

〔Example〕

A slightly curved conical model 1 as shown in Fig. 1 is made of a wooden mold (Japanese pine wood), and a thin film with a depth of 3 ± l mm and a width of 1 to 3 mm is placed on the surface of the model 1 as shown in Fig. 2. Groove 2 was carved to resemble the grain of ivory, and the prototype (male type) A was completed. Silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd.: KE1402) is applied to the surface of this prototype A.
and KE12) was applied and allowed to stand for about 3 hours to polymerize and harden. After curing, the master mold A was pulled out to obtain a mold (female mold) B made of elastomer 3 as shown in FIG.

On the other hand, 100 parts of polyester resin (manufactured by Dainippon Ink Chemical Co., Ltd.: Bolilite TC-141) (weight, same below),
2.4 parts of polymerization catalyst (Dainippon Ink Co., Ltd.: Permec),
Trace amount of polymerization accelerator (cobalt 62), 64 parts of aluminum hydroxide powder, 76 parts of mixed powder of calcium carbonate and chalk powder, 16 parts of titanium oxide, and yellow colorant (pigment PULY)
TON) was mixed and poured into the mold (female mold) B without entraining air bubbles before the viscosity increased, and allowed to stand at room temperature to cause a curing reaction. Approximately 3
When the molded body was taken out from the mold (female mold) B after 0 minutes had passed and the curing reaction was completed, the synthetic resin composition 4 with grooves 2 on the surface as shown in Figure 2 was formed as shown in Figure 4. A product having exactly the same shape as the prototype (male model) A shown was obtained. Therefore, a synthetic resin composition 5 for wood grain with the same composition as the synthetic resin composition 4 except that no yellow coloring agent was added was used.
Before the viscosity increases, in the groove 2 part in Fig. 4,
I applied it so that groove 2 was completely filled, left it to stand at room temperature for about 30 minutes to harden it, and then polished the surface.
Not only does it have a wood grain pattern as shown in the diagram,
Artificial ivory was obtained that was comparable to natural ivory in terms of gloss, specific gravity, hardness, etc.

It has been revealed that the synthetic resin used in this invention is a resin that is curable at room temperature and has a relatively high softening point, and has good workability and processability in both manufacturing and application aspects. , the mold shown in Figure 3 (female mold)
It has also become clear that B can be used repeatedly and can be mass-produced.

〔effect〕

As is clear from the above, according to the method of this invention, physical properties such as wood grain pattern, specific gravity, hardness, elasticity, and color are in no way inferior to natural ivory. Since it is possible to produce artificial ivory that does not have any artificial ivory, it can be said that the significance of this invention is extremely large.

[Brief explanation of the drawing]

FIGS. 1 to 5 are perspective views of molded products sequentially obtained as the process progresses in an example of the present invention.

Claims (1)

[Claims] A synthetic resin composition containing appropriate fillers, colorants, hardeners, and other additives is injected into an elastomer mold (female mold) that is made from a model with wood grains carved in it (male mold) and solidified. After that, the mold is released, and in the recessed part of the obtained molded product,
Production of artificial ivory, characterized in that a resin composition having at least a different color (hue, saturation, lightness, etc.) from the above composition is applied until the recesses are completely filled, and after the resin composition is solidified, the surface is finished by polishing. Method.