JPH04356146A - Method for forming pearl - Google Patents

Abstract

PURPOSE:To enhance both the survival ratio of a pearl oyster and the productivity of pearls by preventing various germs from propagating in the mother pearl nucleus. CONSTITUTION:A pearl mother nucleus formed as a spherical shape calcium phosphate to be an antimicrobial substance is inserted into a pearl oyster to form pearls in the pearl oyster. Thereby, various germs are prevented from entering tissues of the pearl oyster. Furthermore, silver (Ag), copper (Cu)and zinc (Zn) supported on the calcium phosphate can be used as the antimicrobial metal to be supported. In addition, similar action and effects are also obtained even by using a pearl mother nucleus prepared by forming a composite material containing the antimicrobial calcium phosphate (including antimicrobial hydroxyapatite) in a resin into a spherical shape.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming pearls, and more particularly to a method for forming pearls using antibacterial hydroxyapatite as a nacreous core.

0002

[Prior Art] Conventionally, as a method for forming this type of pearl, for example, shells of Victoria oysters, red oysters, etc., polished into spherical shapes were used as mother-of-pearl cores. A method is used to form pearls by inserting the nucleus between the shell and the body of pearl oysters such as oysters, white oysters, and pearl oysters.

[0003] Another conventional method is known in which the surface of a spherical body formed from a shell is made of a metal or colored material as a nacre core (Japanese Patent Laid-Open No. 59-20343).
No. 6).

0004

[Problem to be Solved by the Invention] However, in the former of these conventional methods, since the mother-of-pearl core is formed from natural shells, there is a problem that the number of shells is decreasing. are doing.

In the latter case, the surface of the spherical body is made of metals including alloys or colored materials, and single metals such as gold, platinum, nickel, chromium, etc. Since these alloys and coatings of colored synthetic resin paints are used, even if the biocompatibility with the tissue of mother-of-pearl oysters was improved, there was a limit to the degree of the affinity. In addition, since the mother nucleus is made of a spherical shell such as a snail, it has the same problem as the former described above, which is associated with a decrease in natural products.

Furthermore, when a mother-of-pearl nucleus is inserted into a mother-of-pearl, there is a high probability that lesions will occur in the tissues of the mother-of-pearl due to bacteria adhering to the mother-of-pearl, resulting in the death of the mother-of-pearl. In particular, natural seashells have the problem of easy breeding of bacteria.

[0007]

[Means and effects for solving the problems] Therefore, the present invention provides a mother-of-pearl core formed into a spherical form of antibacterial calcium phosphate, or a mother-of-pearl nucleus formed into a spherical form of a composite material containing antibacterial calcium phosphate in a resin. The solution to this problem is to insert a nucleus into a pearl oyster and allow the pearl oyster to form a pearl.

Currently, many of the shells of shellfish distributed all over the world are composed of calcium carbonate (CaCO3), but shells from the Paleozoic era still contain phosphorus (as seen in the Chamisen shellfish). It is known that the main component was calcium phosphate that incorporated a large amount of P). The process in which the main component of seashells changed from calcium phosphate to calcium carbonate is due to the gradual lack of phosphorus in seawater. Therefore, calcium phosphate compounds that originally contain calcium phosphate, such as antibacterial calcium phosphate such as antibacterial hydroxyapatite, hydroxyapatite, dibasic calcium phosphate, tertiary calcium phosphate, quaternary calcium phosphate, VIII calcium phosphate, calcium pyrophosphate, etc. It can be said that it has high biocompatibility with shellfish.

Due to this biocompatibility, when a mother-of-pearl core made of a spherical form of antibacterial calcium phosphate or a composite material containing antibacterial calcium phosphate in a resin is placed in a mother-of-pearl, the mother-of-pearl layer becomes easier to wrap around.

[0010] Furthermore, since the antibacterial calcium phosphate has fluorescence, it improves the optical characteristics of the appearance of the formed pearls.

Furthermore, spheroidal bodies of antibacterial calcium phosphate such as antibacterial hydroxyapatite, which is made by supporting silver on calcium phosphate, or spherical bodies of a composite material in which antibacterial calcium phosphate is contained in a resin, can be cored in a mother-of-pearl. Since it has an antibacterial effect even after it has been washed, it prevents the death of pearl oysters due to bacteria.

0012

EXAMPLES The details of the method for forming pearls according to the present invention will be explained below based on examples.

In this example, silver-supported antibacterial hydroxyapatite was first prepared with a particle size of 6.5 to 7.5 m using a binder such as a rubber press used for ordinary ceramics.
It is formed into a spherical shape of m to form a mother-of-pearl nucleus.

Next, this mother-of-pearl nucleus is placed between the shell and the body of a mother-of-pearl oyster along with the cut end of the mantle extracted from other Akoya oysters (nucleus insertion), and the normal pearl-forming process is carried out. Similarly, pearl oysters are grown underwater.

[0015] The pearls formed according to this example have good optical characteristics in appearance due to the fluorescence of silver-supported antibacterial hydroxyapatite, and can improve aesthetics.

[0016] In the above-mentioned examples, the particle size of the silver-supported antibacterial hydroxyapatite was set to 6.5 to 7.5 mm, but it is not limited to this, and it can be adjusted depending on the particle size of the target pearl. It is possible to change the particle size of the mother-of-pearl core as appropriate. For example, if you want to obtain a pearl with a large particle size,
It is also possible to increase the particle size of the mother-of-pearl core to about 20 to 30 mm. Even if the pearl grain size is increased in this way, the mother nucleus, hydroxyapatite, has fluorescence, so even if the nacre layer on the mother nucleus is thin, it does not impair the aesthetic appearance of the pearl. It is possible to get shine.

Furthermore, in the above embodiment, the silver-supported antibacterial hydroxyapatite was simply formed into a spherical shape to form a mother-of-pearl core, but by incorporating a pigment into the hydroxyapatite, for example, pink, blue, emerald green, etc. It is also possible to form pearls with a color of . In particular, hydroxyapatite has cavities in its molecular structure, and pigments can be easily absorbed into these cavities, making it easy to add pigments.

Antibacterial hydroxyapatite is made by stabilizing hydroxyapatite or apatites whose OH groups are partially replaced with fluorine or iodine by replacing part of the Ca ions with antibacterial metal ions, and Antibacterial hydroxyapatites are characterized by the fact that antibacterial metal ions are incorporated into the pores of their molecular structure, and in some cases, antibacterial metal salts of phosphate may coexist in some cases. The antibacterial metal and metal ion mentioned herein is silver (Ag), but also includes copper and zinc metals and their ions. All of the antibacterial hydroxyapatites obtained in this way are stable and heat resistant.

Antibacterial hydroxyapatite can be easily produced by coexisting an antibacterial metal salt during hydroxyapatite synthesis, or by reacting hydroxyapatite with a metal salt. That is, N
Hydroxyapatite is synthesized by a conventional method by dropping an aqueous calcium chloride solution while stirring an aqueous solution containing a2HPO4 and antibacterial metal salts, such as metal salts such as silver, copper, and zinc.The product is thoroughly washed with distilled water and dried. The desired product can be obtained by pulverizing the powder, or, taking into account the hardness, color, method of use, etc. of the powder, and firing it at 1350° C. or lower, if necessary, and then pulverizing it.

[0020] Other antibacterial calcium phosphates can also be produced by the same method as above, but at this time, baking is carried out at 1500°C or less if necessary. In these operations, in addition to supported metal ions, acidic roots, metal salts, and calcium salts generated when metal ions replace Ca ions may remain in the antibacterial hydroxyapatite. The antibacterial hydroxyapatite must be thoroughly washed with water to completely remove these contaminants. The amount of antibacterial ions supported on antibacterial hydroxyapatite can be arbitrarily selected depending on the type of antibacterial metal salt used, the temperature of the treatment solution, etc. Since the structure of hydroxyapatite may deviate from the apatite structure, the amount of metal salt is 30% or less, preferably 5 to 0.0001% of the hydroxyapatite.
Good condition.

The antibacterial hydroxyapatite thus obtained retains antibacterial properties for a long time, and the amount of metal leached into water is several ppb or less, so it can be used safely.

Antibacterial Test A binder was added to the antibacterial hydroxyapatite prepared by the above method, compression molded, and degreased at 1000° C. to produce pellets with a diameter of 3 cm containing 100% antibacterial hydroxyapatite.

[0023] As a result of conducting an antibacterial activity test on the pellets, the following antibacterial properties were shown.

[0024]The same results as in the above antibacterial test were also obtained for pellets prepared by mixing 5% by weight of antibacterial hydroxyapatite and 95% by weight of polypropylene, which were fired at 1200°C.

The purpose of containing antibacterial calcium phosphate or antibacterial hydroxyapatite in the resin as in claims 3 and 4 is to adjust the hardness and weight of the mother of pearl.

Further, the amount of antibacterial calcium phosphate or antibacterial hydroxyapatite added to the resin is preferably about 5% by weight or more, preferably about 10% by weight or more, taking into consideration the affinity for nacre and antibacterial properties.

At this time, it is also possible to add a small amount of titanium, zirconia, other ceramics, pigments, etc. in order to adjust the color and specific gravity.

Although any method may be used to mold this composite material into a spherical shape, injection molding is used in the embodiment. An example of a mother-of-pearl core using this composite material is 50% by weight of antibacterial hydroxyapatite fired at 1200°C and 5% by weight of polymethyl methacrylate.
Spheres with a specific gravity of approximately 1.7 when mixed at 0% by weight are heated at 1200°C.
70% by weight of antibacterial hydroxyapatite calcined with
, the specific gravity of a mixture of 30% by weight of polypropylene is approximately 1.
9 balls were created.

[0029]

[Effects of the Invention] As is clear from the above description, the method for forming pearls according to the present invention has the effect of preventing the proliferation of bacteria on the mother-of-pearl core and increasing the survival rate of the mother-of-pearl. In addition, it has the effect of reliably forming pearls that have a good appearance and whose particle size can be easily controlled.

Claims (4)

[Claims] 1. A method for forming pearls, which comprises placing a mother-of-pearl nucleus made of antibacterial calcium phosphate into a spherical shape into a mother-of-pearl oyster, and forming a pearl in the mother-of-pearl oyster. 2. A method for forming pearls, which comprises placing a mother-of-pearl core formed into a spherical shape of antibacterial hydroxyapatite into a mother-of-pearl oyster, and causing the mother-of-pearl oyster to form a pearl. 3. Formation of a pearl, characterized in that a mother-of-pearl core formed into a spherical shape from a composite material containing antibacterial calcium phosphate in a resin is placed in a mother-of-pearl oyster to form a pearl in the mother-of-pearl oyster. Method. 4. A method of producing a pearl, characterized in that a mother-of-pearl core formed into a spherical shape from a composite material containing antibacterial hydroxyapatite in a resin is placed in a mother-of-pearl oyster to form a pearl in the mother-of-pearl oyster. Formation method.