JPH07163266A - Pearl nucleus and its production - Google Patents

Abstract

PURPOSE:To obtain a nucleus used for culturing pearls, being practically inexpensive, not requiring specific equipment, nonpoisonous to mother shellfish, having little rejection by the mother shellfish and excellent in yield. CONSTITUTION:Broken waste shellfish or other shellfish is used as a nucleic material and apatite to which an organic or inorganic binder is added is covered as a main ingredient around the nucleic material and these materials are formed in nearly globular shape and the formed body is fired for a definite time at 900-1300 deg.C to provide the porous pearl nucleus having 35+ or -25m<2>/g specific surface area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pearl nucleus used for pearl culture and a method for producing the pearl nucleus, and more particularly, a pearl nucleus used for culturing pearls which is non-toxic to mother pearls and has a low rejection rate and an excellent yield. It relates to a manufacturing method.

[0002]

2. Description of the Related Art Pearl culture is produced by inserting a nucleus into a mother oyster such as pearl oyster and feeding the mother oyster for a certain period of time to form a pearl layer on the surface of the nucleus. The selection of the nucleus to be inserted into the mother oyster is extremely important for obtaining good yield of pearls. Generally, the nucleus used for pearl cultivation should not be toxic to kill the mother oysters, not rejected by the mother oysters, have good implantation in migrating cells, and have no uneven color It is necessary to satisfy various requirements such as things. For this reason, conventionally, nuclei of pearl oysters and the like that have been globularly polished have been widely used as nuclei for cultured pearls.

However, in the shells such as the blubbers, the percentage of pearls having a high commercial value is low, and the yield of pearl farmers is said to be low. For this reason, for example, Japanese Patent Application Laid-Open No. 60-259153 proposes a technique using a molded body composed of calcium carbonate and a powder selected from pearl powder, coral powder, and crustacean shell powder, and a core using calcium carbonate. Causes a problem of high rejection, low yield, and low implantation property.

For this reason, there has been proposed a technique (Japanese Patent Laid-Open No. 3-2199817) which solves the above-mentioned drawbacks by using a core made of a molded product containing hydroxyabatite. In such a conventional technique, calcium nitrate and ammonium hydrogen phosphate were mixed so that the Ca / P atomic ratio was 10/6 and reacted to precipitate amorphous hydroxyabatite. Then, this is heat-treated to obtain a powder of hydroxyabatite.

Then, the above-mentioned hydroxyabatite powder alone or a mixed powder in which a powder of pigment and calcium carbonate is mixed at an appropriate mixing ratio is subjected to hot isostatic pressing (HIP).
A dense nucleus with a porosity of 0 and a diameter of several mm is obtained by high-temperature and high-pressure treatment at 800 ° C. and about 1500 Kgf / cm ² using an apparatus.

[0006]

However, in the above-mentioned prior art, a special device called a hot isostatic press (HIP) device is used to make the powder into particles, and a high pressure of about 1500 Kgf / cm ² is used. Therefore, a very large amount of cost is required for the manufacturing equipment, and a very small amount can be produced by one batch processing, which is a problem in manufacturing.

For this reason, attempts have been made to make the particle size possible by atmospheric pressure, for example, by sintering, but when the powder is molded at atmospheric pressure, there is a problem in hardness, and seawater is also a problem. It was extremely difficult to maintain and maintain its shape in the mother clam for a long period of time.

In view of the above-mentioned drawbacks of the prior art, the present invention is practically low-cost and requires no special equipment.
The present invention aims to obtain a nucleus used for a method for culturing pearls, which is nontoxic to mother pearl oysters, has little rejection, and has an excellent yield.

[0009]

DISCLOSURE OF THE INVENTION The present invention is characterized by forming a porous surface layer containing hydroapatite as a main component around a core material of crushed scallops and other shells. In this case, the specific surface area of the surface layer is 35 ±
It is better to set it to 25 m ² / g. The invention according to claim 3 encloses crushed blubber and other shells as a core material, and apatite with an organic or inorganic binder added as a main component, and molds it into a substantially spherical shape.
The specific surface area is 35 after firing at a temperature of ~ 1300 ° C for a certain time.
A method for producing a pearl nucleus is characterized by obtaining ± 25 m ² / g porous pearl nucleus.

[0010]

According to such technical means, the particle size is not directly made from the hydroxyabatite powder, but the crushed dough shell and other shells are used as the core material, and the apatite containing the organic or inorganic binder is contained as the main component. Since it is covered, molded into a substantially spherical shape, and then fired, it is possible to easily obtain a pearl nucleus having a predetermined strength even under normal pressure. Further, since it is formed into a substantially spherical shape and then fired without being directly made into a particle size from the powder, it is easy to form a spherical pearl nucleus with no variation in diameter. It is possible to obtain pearls of extremely high quality and with no variation in particle size or shape by culturing them.

In addition, unlike the prior art, the present invention is porous, so that the lymphatic fluid and other growth secretions from the mother oysters penetrate into the pores of the porous material, and the implantability is greatly improved. In this case, when the specific surface area is 10 m ² / g or less, there is no meaning of porosity, and when the specific surface area is 60 m ² / g or more, fine irregularities remain on the surface of the pearls after cultivation and the gloss and quality are deteriorated. Therefore, it is preferable to set the specific surface area to 35 ± 25 m ² / g.

When the firing temperature is set to 1300 ° C. or higher, hydroxyabatite is changed to calcium hydroxide, and at 900 ° C. or lower, a porous material having a predetermined specific surface area cannot be formed. The firing temperature is preferably 1250.
~ 1270 ° C is good. Further, in the present invention, a shell is used as the core material, and the surface layer thereof is the same hydroxyapatite as the bone body of a living being, so that it has good growth affinity. The core material is pearl oyster, white pearl oyster, black pearl oyster, abalone, mabe,
You can use scallops and crows. Further, the core may be formed in a heart shape or a hemisphere shape in addition to the spherical shape according to the shape of the pearl oyster.

[0013]

EXAMPLES Examples of the present invention will now be illustratively described in detail. However, unless otherwise specified, the material, shape, temperature, etc. of each element described in this embodiment are
The scope of the present invention is not limited to this, but is merely an example for explanation. Similar to the above-mentioned prior art, calcium nitrate and ammonium hydrogen phosphate have a Ca / P atomic ratio of 1
Amorphous hydroxyapatite (Ca ¹⁰ (PO ⁴ ) ⁶ (OH) ² hydroxyapatite and monoclinic or carbonate-containing apatite Ca (PO ⁴ ) ⁶ is mixed so that it becomes 0/6 and reacted.
(CO ³ ) ^2- ) is obtained. At this time, a paste such as red iron oxide (red), vanadium yellow, cobalt blue, or cobalt violet may be added when the amorphous hydroxyabatite is produced or after the production.

Next, after crushing the shell of the blubber to form a spherical piece of about 2 mm, a small amount of a known organic or inorganic binder, for example, chitin or conchiolin is added to the amorphous hydroxyabatite. The surface layer forming agent thus obtained is sprinkled, molded into a spherical shape having a diameter of about 6 mm and dried, and then fired at a temperature of 1250 to 1270 ° C. under normal pressure.

The blending ratio of the binder is changed in the range of several to 10% by weight, and the temperature condition is 900 to 127.
0 is varied in the range of ° C., and a plurality of types create a pearl nuclei having a specific surface area in the range of 10m ² / g~60m ² / g. FIG. 1 shows a cross-sectional structure of such a pearl nucleus, in which a porous surface layer 2 containing hydroapatite as a main component is formed around a core material 1 made of crushed dobb shells.

[0016] When such a pearl nucleus was inserted into an pearl oyster and cultured for one year, pearls of good quality with a yield of 85% or more were formed.

[0017]

EFFECTS OF THE INVENTION According to this example, since the porous hydroxyapatite is formed on the surface of the shell nucleus, the collagen of biological growth secretion or easily invades and attaches to grow while producing a growth factor. As a result, the pearls grow quickly and the yield becomes good. Moreover, since there is no variation in the particle size of the core, planned production and production forecast can be performed. In addition, coloring allows the pearl to change its glossiness and color, which significantly reduces the manufacturing cost. It has various remarkable effects.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a pearl nucleus as an example of the present invention.

[Explanation of symbols]

1 Nuclear material consisting of crushed dough shells 2 Porous surface layer containing hydroapatite as a main component

Claims (3)

[Claims] 1. A pearl nucleus characterized by forming a porous surface layer containing hydroapatite as a main component around a core material of crushed scallops and other shells. 2. The specific surface area of the surface layer is 35 ± 25 m ²
The pearl nucleus according to claim 1, which is set to / g. 3. A crushed blubber shell or other shell is used as a core material, apatite with an organic or inorganic binder added as a main component, and the molded body is molded into a predetermined shape. A method for producing a pearl nucleus, which comprises firing at a temperature for a certain period of time to obtain a pearl nucleus having a specific surface area of 35 ± 25 m ² / g