JP2006052183A - Method for peeling pearl layer and prismatic layer of pinctada martensii shell or the like and method for producing pearl powder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for peeling the peal layer and prismatic layer of Pinctada martensii shell, comprising separating the pearl layer and prismatic layer of the Pinctada martensii shell, collecting the pearl layer in a solid state, and precipitating and collecting the prismatic layer in a sludge-like state, by which a large amount of the Pinctada martensii shell can effectively be utilized and by which the pearl layer can stably be produced by the relatively simple method (1) without deteriorating beautiful whiteness and luster and (2) without producing a nasty smell, in order to solve problems such as a problem that most of the shell is discarded as industrial wastes because of producing a nasty smell in a treating process and in an experimental utilization method, although methods for using the Pinctada martensii shell have been examined, and a problem that the beautiful whiteness and luster are affected by contaminants contained in the prismatic layer, when the peal layer and the prismatic layer are together crushed. <P>SOLUTION: This method for peeling the peal layer and prismatic layer of the Pinctada martensii shell comprises immersing and leaving about 60 kg of water-washed Pinctada martensii shell in a 6% sodium hyprochlorite aqueous solution for about 72 hours to peel the pearl layer from the prismatic layer, and immersing the treated shell in an aqueous solution in a meshed container to facilitate the recovery, because the pearl layer holds the shape, while the prismatic layer is precipitated in a sludge state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention mainly chemically separates the pearl layer and the ridge column from the pearl oyster shell, the pearl layer is mainly used for cosmetic pigments, and the ridge column is a chemical for use as a raw material (fertilizer) for soil improvement. It relates to a simple peeling method.

  Conventionally, treatment methods for obtaining pearl layers of shells have been proposed to use pearl oyster shells as raw materials for foods, pharmaceuticals, food additives, and cosmetics, and they are used by collecting pearl layers from pearl oyster shells. The pearl oyster shell is divided into a pearl layer and a ridge pillar layer, and this pearl layer is known to have the same structure chemically and physically as the pearl.

  As a method for collecting a pearl layer from an pearl oyster shell, conventionally, the attached value on the shell is simply removed by washing with water or a brush, and the utility value of the shell is low and it takes a lot of time. For this reason, Akoya oyster shells are often generated as a byproduct of pearl farming, but most of the remaining shells are discarded due to their small use.

  In the above situation, methods for extracting the pearl layer powder from the pearl oyster shell are described in Japanese Patent Publication No. 6-43320 and Japanese Patent Laid-Open No. 2002-338430. These mainly present a method of peeling the nacreous layer and the ridge column after grinding the shell. For example, a case of using a known rotary tiltable barrel type polishing machine and 5% to 20% hydrochloric acid has been reported.

When the pearl layer and the ridge column layer of the pearl oyster shell are pulverized together by the method described in the known example, the whitening and luster of the pulverized powder are lost due to the contamination contained in the ridge column layer. I'm gone. In addition, an unusual odor peculiar to the pearl oyster shell was generated, and the odor elimination was performed with acetic acid. As a result, the acetic acid odor became strong and was not suitable as a pigment for cosmetics.
Japanese Patent Publication No. 06-043320, Japanese Patent Laid-Open No. 2002-338430

  Therefore, it is desired that (1) whitening and gloss are not impaired, and (2) a nacreous layer that does not generate off-flavors can be stably produced by a relatively simple technique. For example, a pearl pigment having a particle size of 500 nm is produced from pearl oyster shells at 20 kg / month. The resulting pearl pigment is "whitening, gloss and odorless".

  In order to solve the above-mentioned problems, a mesh-like container for storing an appropriate amount of pearl oyster shell and a sodium hypochlorite aqueous solution container having a concentration of about 6% are stored in a mesh-like container in a sodium hypochlorite aqueous solution container. Immerse the pearl oyster shells and leave them for about 72 hours.

  The method for peeling the pearl layer and the ridge pillar layer of the pearl oyster shell of the present invention produces a pearl powder by pulverizing the pearl layer that does not impair the whitening and gloss of the pearl layer and has no off-flavor into about 500 nm particles with a pulverizer There are advantages that can be made.

  Using a mesh-shaped container for storing an appropriate amount of pearl oyster shell and a sodium hypochlorite aqueous solution container having a concentration of about 6%, the pearl oyster shell contained in the mesh-shaped container is placed in the sodium hypochlorite aqueous solution container. Immerse and leave for about 72 hours to peel the pearl oyster shell into a pearl layer and a ridge column. The pearl layer obtained by the above method is sufficiently washed and dried, and then pulverized into particles of about 500 nm by a pulverizer to produce pearl powder.

  The ridge column layer from which the pearl oyster shell is peeled into the pearl layer and the ridge column layer is neutralized with sodium sulfite in an aqueous solution of sodium hypochlorite precipitated in sludge form, and then dried and recovered as slaked lime.

  Sodium hypochlorite with a concentration of 6% has a strong ability to collapse the ridge column of the pearl oyster shell, and has both the bleaching power and sterilizing power of the pearl layer. If the concentration of sodium hypochlorite is 5% or more, the peeling ability will not change, but if the concentration is high, the generation of chlorine gas and the production cost will be expensive, so safety is emphasized and it is commercially available at a low price. 6% concentration sodium hypochlorite was used.

The chemical formula of bleaching with sodium hypochlorite and peeling of the outer shell (ridge column layer) is as follows.
2NaClO + H ₂ O → Cl ₂ + 2NaOH (Cl ₂ is bleaching action)
CaCO ₃ + NaClO → NaCl + CaCO ₄ (calcium carbonate changes to slaked lime)

  FIG. 1 shows the pearl layer and pearl component analysis (EDX; energy dispersive X-ray analysis) of the pearl oyster shell, (A) shows the pearl layer of the pearl oyster shell, and (B) shows the pearl analysis result. Both were confirmed to be calcium carbonate components.

  FIG. 2 shows a basic configuration diagram for peeling an pearl oyster shell, which is an embodiment of the present invention, into a pearl layer and a ridge-column layer. 1 is a sodium hypochlorite aqueous solution, and 2 is a sodium hypochlorite aqueous solution. 3 is an oyster shell, 4 is a mesh-like container storing the pearl oyster shell, and 5 is a sludge-like deposit from which the ridge pillar layer is peeled off.

  FIG. 3 shows a procedure for peeling the pearl oyster shell, which is an embodiment of the present invention, into a pearl layer and a ridge pillar layer. In the figure, the procedures shown in A) to H) show the procedure from peeling the pearl oyster shell into a nacreous layer and a ridge-pillar layer until the production of pearl powder. J) to L) show the procedure for recovering the sludge deposit in the sodium hypochlorite aqueous solution after the ridge column layer is peeled off from the pearl oyster shell.

  Hereinafter, with reference to the procedure shown in FIG. 3, the outline | summary which peels a pearl oyster shell into a pearl layer and a ridge pillar layer is demonstrated.

  The procedure up to the production of pearl powder is based on the results of previous investigations for recovering the nacre from the pearl oyster shell, and the yield for recovering the pearl from the pearl oyster shell was approximately 30%. Therefore, the 20 kg pearl layer is recovered. Requires 60 kg of pearl oyster shells. Therefore, 60 kg of pearl oyster shells are washed with water; FIG. 3 (A), the pearl oyster shells are stored in a mesh-shaped container every about 10 kg; FIG. 3 (B), a volume for storing 120 liters of sodium hypochlorite aqueous solution. About 10 kg of pearl oyster shells are stored in a 500-liter resin container, and a mesh-like container is placed in the container for 72 hours; FIG. 3 (C).

  72 hours later, the mesh-like container is taken out; FIG. 3 (D), thoroughly washed with running water and examined for ridge column residue on the pearl oyster shell; FIG. 3 (E), if there is no residue; (F) yes, the pearl layer of the pearl oyster shell is naturally dried; FIG. 3 (G), the pearl layer of the naturally dried pearl oyster shell is pulverized to a mean particle size of 500 nm with a jet mill pulverizer; . The generation of the pearl powder is completed by confirming that the pearl powder generated here is not whitened, glossy and offensive odor.

  In the procedure described above, if there is a residue in the determination of FIG. 3 (F); FIG. 3 (F) left in a sodium hypochlorite aqueous solution tank for 3 to 4 hours; FIG. Take out; Fig. 3 (D), rinse thoroughly with running water and check for ridge column residue on Akoya shells; Fig. 3 (E). If there is no residue, follow steps in Fig. 3 (G) (H). A pearl powder is produced.

  The procedure for collecting sludge precipitates in sodium hypochlorite aqueous solution is that the ridge column layer is changed to slaked lime in the aqueous solution from which the nacreous layer has been removed, so that sodium sulfite is converted to sodium hypochlorite. FIG. 3 (J) The precipitate in the sodium hypochlorite aqueous solution is filtered and collected by a filter; FIG. 3 (K), the collected precipitate is dried to produce fertilizer. FIG. 3 (L).

  As described above, the nacreous layer and the outer shell are chemically separated from the shell of the pearl oyster shell, the nacreous layer is mainly used as a cosmetic pigment, and the ridge pillar layer is used as waste material for soil improvement (fertilizer). Effective utilization of the treated pearl oysters becomes possible.

Component analysis of pearl layers and pearls of pearl oyster shell (EDX; energy dispersive X-ray analysis) The basic block diagram which peels the pearl oyster shell which is one Example of this invention into a pearl layer and a ridge pillar layer is shown. The procedure which peels the pearl oyster shell which is one Example of this invention into a pearl layer and a ridge pillar layer is shown.

Explanation of symbols

1 Sodium hypochlorite aqueous solution 2 Container containing sodium hypochlorite aqueous solution 3 Akoya shells 4 Mesh-like container for storing Akoya shells 5 Peeled ridge pillar layer

Claims (1)

  Akoya shells (shells equivalent to the components of Akoya shells, etc.) are thoroughly washed and stored in a mesh-like container, and left in an aqueous solution containing about 6% sodium hypochlorite for about 72 hours. The pearl oyster shell is separated into a pearl layer and a ridge pillar layer (sludge-like precipitate), and 1) the pearl layer from which the ridge pillar layer has been peeled off from the pearl oyster shell is sufficiently washed and dried, A pearl powder is produced by pulverizing into particles of about 500 nm. 2) After neutralizing the aqueous solution of sodium hypochlorite in which the peeled ridge column layer is precipitated in sludge form with sodium sulfite, the sludge form precipitate is obtained. 3) A method for peeling pearl oyster shells characterized in that the pearl layer and the ridge pillar layer are easily collected by storing the pearl oyster shells in a mesh-like container.

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