JPH1087307A - Production of calcium phosphate-containing composition having antimicrobial property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a calcium phosphate-contg. compsn. having antimicrobial property by allowing shells of animals to react with phosphoric acid compds., especially by effectively using sea shells which are usually treated as an industrial waste. SOLUTION: Shells of animals are made to react with phosphoric acid compds. to obtain calcium phosphate having antimicrobial property. As for sells of animals, especially seashells or fresh water shells (e.g. oyster and scallop) are preferably used. As for the phosphoric acid compds., phosphoric acid or phosphates such as calcium phophate, bruncite and monetite can be used. To produce the calcium phosphate having antimicrobial property, animal shells are pulverized to prepare a water suspension having 2 to 15wt.% concn., and then phosphoric acid compds. are added by 0.3 to 0.33 equiv. calculated as P2 O5 to calcium (CaO) in the reaction liquid at 50 to 150 deg.C for 1 to 5 hours.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the use of animal shells, particularly shells, which have been largely discarded.
The present invention relates to a method for producing calcium phosphate having antibacterial properties.

[0002]

2. Description of the Related Art Conventionally, calcium phosphate has been produced from lime and a phosphate compound. However, this method has a problem of mining limestone and accompanying natural destruction, and the cost of raw materials has been rising. By the way, despite the fact that natural shells contain large amounts of calcium carbonate, some of them are used as soil conditioners, neutralizers, raw materials for herbal medicines, etc. Treated as waste.

[0003]

SUMMARY OF THE INVENTION The present inventors have conducted intensive studies to effectively use shells disposed of as industrial waste, and as a result, not only shells but also calcium carbonate including them. The present inventors have found that a component having an antibacterial effect and containing calcium phosphate can be obtained at low cost from animal shells containing the compound, and have completed the present invention.

[0004]

That is, the present invention is characterized in that an animal shell is reacted with a phosphate compound.
Method for producing calcium phosphate having antibacterial properties

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the shell of an animal to be subjected to a reaction with a phosphate compound may be any one containing calcium carbonate, for example, a coelenterate animal (eg, Kansashigokai, etc.), an echinoderm animal ( Eg, sea urchins), molluscs (eg, squid, shellfish, cochleas, etc.), arthropods (eg, crustaceans, etc.) and vertebrate (eg, birds) shells, shells and eggshells. These may be used alone or as a mixture of two or more. From the viewpoints of availability and quantity, particularly preferred are seawater and freshwater shellfish (eg, oysters, scallops, etc.). .

[0006] If necessary, these animal husks are cleaned and then ground as a raw material for calcium carbonate (CaCO ₃ ) or, preferably, to an average particle size of about 1 to 10 µm to react with the phosphoric acid compound. Can be offered.

[0007] Phosphoric acid compounds used for the reaction with animal hulls include phosphates such as phosphoric acid, monocalcium phosphate, brushite and monetite. The reaction between the animal hull and the phosphate compound varies depending on the amount of calcium carbonate and quick lime in the animal husk to be subjected to the reaction. The reaction is carried out at 50 to 150 ° C. for 1 to 5 hours using a phosphoric acid compound of 0.3 to 0.33 equivalent as phosphoric acid (P ₂ O ₅ ) with respect to calcium (CaO) in the reaction solution. . If necessary, the obtained reaction mixture is neutralized and used as it is, or the reaction product is separated by a conventional method such as filtration or centrifugation, and dried at 150 to 500 ° C. for use. The composition of these reaction products can be identified and analyzed by X-ray diffraction or IPC emission spectrometry, and usually a reaction product containing 15% by weight or more of calcium phosphate per solid content of the reaction product is obtained.

[0008] The resulting calcium phosphate-containing composition comprises:
Like the known calcium phosphate, it can be used in the fields of pharmaceutical raw materials, food additives, toothpastes, and the like.

[0009]

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. In Examples, “%” means “% by weight” unless otherwise specified. Example 1 Oyster husk powder (calcium carbonate content 96%; average particle size 6μ)
m) 1000 g of water and 9000 g of water were added, and the mixture was stirred well and suspended.
1285 g of phosphoric acid was added dropwise over 1 hour to cause a reaction. After completion of the reaction, the reaction mixture was filtered, and the remaining solid content was washed with warm water. Then, dried at 250 ° C. for 5 hours,
1150 g of a reaction product was obtained. This was ground with a sample mill to an average particle size of 9 μm. X-ray diffraction of this reaction product,
Analysis by ICP emission analysis revealed that it contained 15% calcium phosphate and 85% hydroxyapatite.

Example 2 In the same manner as in Example 1, except that scallop powder (calcium carbonate content: 95%; average particle size: 3 μm) and its calcined product (calcined at 1200 ° C. for 2 hours) were reacted with phosphoric acid. The reaction product was obtained at a temperature of 150 ° C. The results of component analysis by X-ray diffraction and ICP emission analysis of the obtained reaction product are shown below.

CaO: 55.04% P ₂ O ₅ : 38.02% CaO / P ₂ O ₅ molar ratio: 3.66 Loss on burning: 3.18%

Example 3 Antibacterial test of the composition obtained in Example 2 The calcium phosphate composition obtained in Example 2 was sterilized in a high-pressure steam sterilizer at 121 ° C. for 15 minutes. 500 μg / ml or 5000 μl on a nutrient agar plate
g / ml, suspended in a petri dish, allowed to stand for 3 hours, and cultured at 37 ° C. for 48 hours to evaluate the antibacterial activity against falling bacteria in the air. Table 1
As shown in the above, the calcium phosphate composition obtained in Example 2 exhibited remarkable antibacterial activity, and no growth of bacteria was observed.

[0013]

[Table 1]

[0014]

As described above, according to the present invention,
A conventionally used calcium phosphate composition having an antibacterial effect can be provided at low cost by using animal shells, particularly shells, which have been discarded.

Claims (4)

[Claims] 1. A method for producing antibacterial calcium phosphate, comprising reacting an animal shell with a phosphate compound. 2. The method according to claim 1, wherein the animal shell is a shell. 3. The method according to claim 1, wherein the phosphate compound is phosphoric acid or a salt thereof. 4. An animal hull is crushed into a 2 to 15% by weight aqueous suspension, to which calcium (CaO) in the reaction solution is added.
A phosphoric acid compound in an amount of 0.3 to 0.33 equivalent in terms of phosphoric acid (P ₂ O ₅ ), and reacted at 50 to 150 ° C. for 1 to 5 hours. A method for producing calcium phosphate.