JPS59217610A - Production of calcium-phosphorus based apatite - Google Patents

Abstract

PURPOSE:To produce the titled apatite of high quality by easy method, by reacting a calcium compound with a phosphorus compound in a reaction medium containing water and a water-miscible organic solvent. CONSTITUTION:A calcium compound and a phosphorus compound, e.g. Ca(H2PO4)2.H2O, CaHPO4.2H2O, CaHPO4, Ca(OH)2 or CaCO3, are preferably mixed to give 1.30-1.90 desired ratio (Ca/P) and charged previously into a reaction tank, and an adequate amont of water is then added thereto to slurry the compounds. A water-miscible organic solvent, e.g. iso-propanol or tert- butanol, is then added thereto, and the resultant mixture is heated under refluxing. About 2hr refluxing time is sufficient. The titled apatite is then deposited in a slurrylike form and separated by filtration Thus, the titled aimed apatite can be produced with high reproducibility by the easy method.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new method for producing calcium-phosphorus apatite.

In general, apatite has the general formula M (ZOj).

It is represented by Yl. In this formula, M is Ca, Pb, Sr, Ba, Mg, Na,
K, Ni, Fe, kl and other metal atoms, 20, are PO4, As04, VO4, SOa, ,
S i 04 , CO3 and other acid radicals, Y is F, OH, C1, Br, I0. A general term for a wide range of compounds represented by CO3 and other anionic atoms (groups).

In the present invention, M in the above general formula is substantially C
a, and 20. Since the target is a group of compounds in which is essentially PO, it is called "calcium IJ-based apatite".
This is abbreviated as Ap in the following explanation.

Among the Ap group, hydroxyapatite (hereinafter hydroxyapatite is abbreviated as HAp) in which Y is substantially OH has recently attracted attention as a raw material for bioceramics, and its application to artificial bones, artificial teeth, etc. is being considered. Furthermore, Ap
The effect is noticeable in laser materials, catalysts for alcohol dehydration, fluorescent materials, electronic materials, inorganic ion exchangers, and especially HAp. It is also seen as a promising packing material for chromatography for separation and purification by taking advantage of its good biocompatibility.

Regarding Ap, the manufacturing method has been published in many patents and documents for a long time. The main ones are as follows.

(1) A hydrothermal synthesis method in which anhydrous calcium hydrogen phosphate and phosphoric acid are reacted in an autoclave under conditions of 100 to 500°C and 1 to 500 atm for about 48 hours.

(2) A dry synthesis method in which tricalcium phosphate and calcium oxide are reacted at a high temperature of 900 to 1300°C for about 3 hours under a stream of steam.

(3) Water-soluble phosphate and calcium salt in an aqueous solution
A wet synthesis method that approaches stoichiometric ratio by reacting at 7°C and pH 7 to 8 for 20 days or more.

However, both methods (1) and (2) require expensive equipment because the reaction is carried out at high temperature and pressure, and furthermore, the equipment is complicated to operate and consumes an enormous amount of energy. How about method (3)? However, slight differences in conditions can greatly affect the composition of the product.
Furthermore, in order to obtain Ap with a stoichiometric composition, an operation of 20 days or more is required, which is almost an industrial practice, and the obtained results are not very reproducible.

For these reasons, it has been extremely difficult to quantitatively synthesize a practical amount of Ap using conventional techniques. Therefore Ap
Despite its excellent physical properties, it is difficult to manufacture, making it expensive, and the reality is that it is only used for very limited purposes.

The present inventors have arrived at the present invention as a result of research into a method for easily obtaining a large amount of Ap with excellent quality.

That is, the present invention is a method for producing calcium-phosphorus apatite, the technical features of which are as described in the claims. This technology allows a calcium compound and a phosphorus compound to react by using a reaction medium and an appropriate amount of water as necessary during the reaction, and can be reproduced at a relatively low temperature under normal pressure and in a short time. It is possible to obtain Ap in the form of fine powder or aggregates depending on the purpose with good properties.

In carrying out the present invention, a calcium compound and a phosphorus compound are charged in advance into a reaction tank at a desired Ca/p ratio, and an appropriate amount of water is added to form a slurry. Next are organics that can be mixed with water. Add a solvent and heat to reflux. A reflux time of about 2 hours is sufficient. Note that the heating reflux time and the order of charging raw materials containing organic solvents to the reaction tank are generally carried out as described above, but are not necessarily limited thereto.

After the heating is completed, the produced Ap precipitates and becomes a slurry, which should be separated.

As for the separation method, the usual method using only separate furnaces and the method of separating Ap after evaporating water together with the organic solvent can be applied.

In particular, in the latter method, dehydration is performed while adding an organic solvent in a volume corresponding to the distilled water and the organic solvent, and after the dehydration is completed, the organic solvent and Ap are separated from each other. The latter method is preferred in that Ap can be completely dehydrated.

Calcium compounds and phosphorus compounds that can be used in the present invention include H3PO4, 'Ca (H2PO4)
2H20, Ca(POa)2, CaHPO4%
CaHPO4e2H2den Ca2 Px 07, Ca3
(PO+)2s Cab, CaCA, , Ca(O
H)2, CacOa, Ca F2, Ca (NO3
)2, Ca(Coo)2, etc. can be used. However, the raw materials that can be used in the present invention are not limited to these.

The present invention can be carried out under favorable conditions by appropriately selecting two or more of the above compounds and blending them so that the atomic ratio of calcium to phosphorus (Ca/P) is 1.30 to 1.90. The raw materials to be used should be selected depending on the use and purpose. CaF
2 may be used, and if a calcium-phosphorus apatite containing chlorine is desired to be obtained, Ca C12 may be used. HAp can also be obtained without using these norogen compounds.

The higher the purity of the calcium compound and phosphorus compound used, the easier it is to obtain a product with high purity, and the reaction time is short, which is preferable. It is advisable to select raw materials of appropriate purity depending on the purity required for the material. In addition, when using it as a biomaterial, it is preferable to select a raw material with a low content of impurities such as Fe, Ni, and Zn, heavy metals, and other biohazardous substances. In general, industrial grade raw materials can be used satisfactorily.

In the present invention, the amount of calcium and phosphorus charged during the reaction is C
A obtained when the a/P atomic ratio is in the range of 1.30 to 1.90, preferably in the range of 1.45 to 1.75.
This is convenient because there are almost no unreacted substances in p. The target ApQ atomic ratio (Ca/P) is theoretically 5/3, so the optimal Ca/P ratio at the time of preparation should be 5/3, but in actual reaction, If the atomic ratio is within the above range, Ap can be synthesized under favorable conditions. Furthermore, it has been confirmed that even if the Ca/P ratio is from 1.30 or less to 1.90 or more, Ap with sufficient physical properties can be obtained for other Ap uses.

However, the organic solvent used in the present invention may be any organic solvent as long as it can form a homogeneous phase when mixed with water. Although the suitability of the organic solvent to be used may differ depending on the selection of state variables, organic solvents that are generally convenient for carrying out the present invention include n-propyl alcohol, 1so-propyl alcohol, tert.
- Various alcohols such as phthyl alcohol and hyethylene glycol, diethylene glycol, and triethylene glycol, various cellosolves such as methyl cellosolve and butyl selonulf, and calpitols such as methyl calpitol and diethyl calpitol, which can be mixed with water. Ethers, diacetone alcohol, ketones such as acetylacetone, triethylamine, trif-8f-ruamine,
Amines such as pyridine, methylcerone rubacetate,
Examples include esters such as methyl carpitol acetate and carpitol acetate, organic acids such as acetic acid, propionic acid, butyric acid, and lactic acid, and organic solvents that are miscible with water such as dimethylformamide, acetonitrile, and dimethyl sulfoxide. These are only examples of organic solvents that can be used in the present invention, and the present invention is not intended to be limited thereto.

The amount of organic solvent added depends on its type, calcium during the reaction,
Although the appropriate value differs depending on the type of phosphorus compound and various conditions during the reaction, it is desirable to add an amount such that the slurry concentration is 50% or less under all conditions.

From the above, the conventional method of manufacturing Ap is at high temperature, high pressure,
From the viewpoint of industrial implementation over a long period of time, there were many unreasonable aspects such as enormous consumption of energy, expensive equipment, and complicated operations.However, in the present invention, by coexisting an organic solvent, Because the only method is to react at a low temperature and then dry the resulting crystals from door to door, thermal energy consumption is extremely low, and the manufacturing equipment is simple and inexpensive. A manufactured material is also sufficient.

As described above, the present invention makes it possible to quantitatively produce Ap with good reproducibility at low cost, which is difficult to produce simply and conveniently using conventional methods, and has great industrial value. be.

The present invention will be described in detail below with reference to Examples.

Example 1 Calcium hydrogen phosphate dihydrate (dicalcium phosphate)
dihydrate) 1o3.2oy, calcium hydroxide 28.12
@, 12o7 water, 400 g tert-butanol, 1
The water and tert-butanol in the reaction system were evaporated, and the distilled tert
Dehydration was carried out while adding tert-butanol in a volume equivalent to -butanol and water into the system. As the dehydration progressed, the internal temperature rose, and when it exceeded 83°C, heating was stopped, and after cooling, the product (precipitate) was separated from the solvent and dried to obtain a white powder. The X-ray diffraction pattern of this powder is shown in the drawing.

As is clear from the drawing, the diffraction angle 2θ = 31.7.32
．． 2-132.8, with a main peak at 2-132.8 (ASTM car)”
This coincided with the characteristic diffraction peak of hydroxyapatite described at 9-432K. This figure shows that the obtained I-(Ap) is an amorphous powder.

Examples 2 to 4 Calcium hydrogen phosphate dihydrate, anhydrous calcium hydrogen phosphate, calcium carbonate, calcium hydroxide, water, and organic solvent were prepared under the respective conditions shown in Table 1. The calcium-phosphorus apatite of the present invention was obtained by the same operation as in Example 1 except for the following conditions.

As shown in the results shown in Table 1, calcium-phosphorus apatite was quantitatively obtained using the technique of the present invention at a relatively low temperature of 200°C or less and in a short period of time.

[Brief explanation of the drawing]

The drawing shows the X-ray diffraction diagram of calcium-phosphorus anositite obtained by implementing the present invention (Example 1).
:'] It's made with Nidorase. Patent applicant Mitsui Toatsu Chemical Co., Ltd. Procedural amendment (voluntary) October 1, 1980 Kazuo Wakasugi, Commissioner of the Patent Office1, Indication of the case Patent Application No. 89288, 19892, Name of the invention Calcium- Method for producing phosphorus apatite 3, Person making the amendment Column 5 of “Detailed Description of the Invention” of the specification, Contents of the amendment 1) Specification, page 6, lines 2-3 [I-I, PO4
, Ca (HzPO*)2I-12, OJ as “H3PO
4. H, P, O? , l-lPO3, PI Os, Pct
,,PCl5,Ca (HaP O+) ·HzOj. 2) Similarly, on page 10, page 1, page 11, line 1, delete "This figure shows that the obtained I-IAp is an amorphous powder." . on μ

Claims (2)

[Claims] (1) A method for producing calcium-phosphorus apatite, which comprises reacting a calcium compound and a phosphorus compound in a reaction medium containing an organic solvent that can be mixed with water to form a homogeneous phase. (2) The method according to claim 1, characterized in that the atomic ratio of calcium to phosphorus is Ca/P in the range of 1.30 to 1.90.