JPS5921509A - Manufacture of hydroxylapatite - Google Patents

Abstract

PURPOSE:To obtain easily hydroxylapatite with high crystallinity and high chemical activity in a short time by applying grinding when a Ca source is reacted with a P source. CONSTITUTION:An aqueous soln. or a suspension contg. Ca(OH)2 and >=1 kind of Ca salt such as CaCl2 or Ca(NO3)2 and an aqueous soln. or a suspension contg. H3PO4 and >=1 kind of phosphate such as NH4H2PO4 or Ca(H2PO4)2 are prepared. They are mixed under grinding and reacted, or they are mixed, ground and reacted. Hydroxylapatite obtd. by this method has high crystallinity, high purity, large specific surface area and superior chemical activity, so it is useful as a dental material, a starting material for manufacturing an artificial bone, an adsorbent, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing crystalline hydroxyapatite with high L content, constant quality, and chemical activity.

Hydroxyapatite has the formula “10(PO4)6(O
II) is a basic phosphoric acid represented by 2,
Main dllT in the living body that makes up bones, teeth, etc.
It is the f'itl component. Hydroxyapatite is attracting attention as a new inorganic material because of its excellent affinity with L compounds. Various methods are known, such as a dry method using a precipitation reaction and a wet method using a precipitation reaction. However, in order to produce hydroxyapatite, which is highly chemically active, it is necessary to combine a calcium salt aqueous solution and a phosphate aqueous solution, or a calcium hydroxide and phosphoric acid solution. A wet method in which ripening is performed after a mixed reaction is said to be advantageous. However, the known wet method and the hydroxyapatite obtained from this method have the following disadvantages: (1) It requires a long aging process at high temperature. (The stoichiometric Ca/P molar ratio of former hydroxyapatite is 1.67. However, in the wet method,
Amorphous calcium shellate (''/p molar ratio = about 1.48 to 1.67), calcium ion-deficient hydroxyapatite, calcium octaphosphate, etc. (hereinafter referred to as precursors) produced by the reaction are aged. In the process of finally transforming into hydroxyapatite crystals, crystals (hyperate, Ca
The Cn/p equimolar ratio of hydroxyapatite crystals is 1.48 because it is susceptible to changes in the molar ratio, temperature, l)H, aging time and many other factors.

~1.67, (7) Within ItQ...? Causes trouble,
As a powder.

Is the property of □ also homogeneous? , (Sui, (fil+ball obtained by wet method) □ Hydroxyl ano-blue tight compound has a low degree of condensation in -M"' and tends to form a gel-like substance, so the chemical conversion operation is complicated. This is also a factor that causes the equimolar ratio of CB/p to fluctuate.

In view of the problems with the known wet production method of hydroxyapatite, the inventor of the tree has conducted various experiments and researches, and has discovered that a grinding process is used in conjunction with the reaction process between the raw calcium source and the phosphorus source. Therefore, these problems can be resolved by causing an aqueous solution or suspension containing at least one of phosphoric acid and phosphoric acid to react while grinding, or by causing a grinding reaction after mixing. The present invention relates to a method for producing hydroxyapatite, which comprises:

:・According to the An Yoriaki method, the degree of sonication is high, the Ca/p equimolar ratio is extremely close to 1.67, and the chemical activity is large, l, N.
,, '1 Yu, 1 Hydroxyl abalite can be easily produced within a short time without requiring aging at high temperatures. Furthermore, the product can be made into a highly pure σ]hydroxide ano(tight product) by a simple water washing operation.

In the present invention, the calcium source is Ca(OH
)2 or CaCl2,'Cm(,N'OR)'2,
(CHBCOO)sCa, (Cab) 4:
One or more calcium salts such as P2O3, CFLz(HPO4) (OH)2, etc. are used as an aqueous solution or suspension; □13PO as a phosphorus source.

or NlI4112PO4+ (NH4>'2HPO4
, Ca(1(2PO4)2.

One or more phosphates such as Ca11PO4 are used as an aqueous solution, water, or suspension. Ca(OH)2 and/
Or, the concentration of calcium salt in the liquid is usually about 4 to 16 F#% as Ca(OH)2 (hereinafter referred to as ``damo'' refers to 1-fold f#%), and the concentration of H8P O4 and/or phosphate in the liquid. is usually about 2 to 8% as HsPO4, and is reacted by mixing them while grinding or by grinding them after mixing. If the concentration of the raw materials is too low, it may On the other hand, if the concentration is too high, the milling time required to transfer the produced precursor to hydroxyl avatarite becomes longer, which is also economically disadvantageous. The temperature during the reaction is not particularly limited, but is preferably 100°C or less, and generally room temperature is sufficient.The PIl of the reaction system is 7
If it's 7 or above, it's good.

In the present invention, it is essential to react the calcium source raw material and the phosphorus source raw material and to grind the generated precursor material. Examples of the grinding means include stirring mills using a grinding medium such as a Tatsuzen mill, a →J mill, and a grain mill. , stirring the liquid into L(1) without using a crushing medium, for example, by rotating the liquid, cannot sufficiently promote the transition of the precursor to hydroxyapatite, and the resulting water The properties of acid apatite are also not satisfactory.The grinding employed in the present invention refers to an operation in which the object to be treated is ground mechanochemically using a large number of media that move continuously in a container. As for the media, specific gravity is 2.0 to 8.OW/crn
”.

Preferably 2.2 to 6. OF/cm"0.5~50
A ball of about m+rl is usually used. As the media, media made of ceramic such as alumina balls and glass beads are preferred.

The hydroxyapatite obtained by the method of the present invention has a high degree of condensation, high purity, large specific surface phase, and excellent chemical activity, so it can be used as a manufacturing raw material for tooth abrasion materials, artificial bones, etc., and for adsorption. agent,
It is useful as an additive to foods and other products.

Example 1 1 mm glass beads (ratio fJ'X 2.59/cm
Schiff, 6~ as the grinding medium FiK 1.41 → non-domil' L! :,′! □ Degree lO%, temperature (: 25°
After calcium hydroxide suspension El I of C Pll 1.3
．． 1) 2.96 Ky is IIV, [ is 1 rotation number (
While stirring at 13゛f with iQ Orp+n, i[lLI
After dropping 40% phosphoric acid solution in water over 114 minutes, stirring and grinding was continued for an additional 10 minutes.The ratio of Ci'l/PPll in the reaction system was 1.
It was 67. A water suspension of the obtained hydroxyl powder 1 was dehydrated with a filter press 12, and then [added ζ・HaIt:
The X-ray diffraction diagram of the dry material is not shown in Fig. 1, and the peak fraction is narrow (t is < 11, the value of 11 b1 is also narrow, indicating the straightness of the acoustic intensity of the itt material. In addition, the specific surface area of the dried product (according to the i3ET method) is 150
+n2/P, Ca/1) molar ratio was 1.6G.

Comparative Example 1 (a) A reaction product was obtained in the same manner as in Example 1 except that glass beads were not used as the grinding medium.

The X-ray diffraction pattern of the reaction product obtained by dehydrating it with a filter press and drying it by heating is as shown in Figure 2. The peak separation is poor, the half-width is narrow, and the components other than hydroxyapatite are not detected. Peaks (++) and (l]) are observed.

(b) Is the reaction product obtained in the same manner as in (a)′ above in the reaction solution? After being left at 11' temperature for 24 hours, the X-ray diffraction pattern of the sample was dehydrated with a filter press and dried by heating for 17 hours. However, high purity hydroxyapatite could not be obtained.

Example 2 Phosphoric acid aqueous solution with a concentration of 40% m 0.6 K? Hydroxyapatite crystals were obtained in the same manner as in Example 1, except that the mixture was heated for about 20 minutes.

The X-ray diffraction pattern of the obtained crystal is similar to that in Figure 1, and C
The n71 molar ratio was 1.67.

Example 8 In a sand mill with a volume of 141 using 1 mm glass beads 7, 5 and K9 as the grinding medium, suspension i' (
[2,58 images each were housed and rotated at a rotational speed of 600 rprn, and a concentrated calcium hydroxide suspension (1,744 cm) was dropped over about 1 minute.ftF
4q: n, ', target IL reaction [r,; liquid was collected, dehydrated and dried, starting from the start of t+'T. According to the X-ray diffraction results of the obtained dry powder, Mi 40 minutes after the start of T, completion of the conversion of the precursor to hydroxyapatite was observed.

Comparative Example 2 In the same manner as in Example 8, except that the triturated tJ r-1+ was not used, 1 liquid of the hydroxide lucium l- suspension was added dropwise to the dibasic calcium phosphate suspension in step 12, and then the mixture was heated at room temperature for 6 hours. 1] I washed it and left it for another 24 hours. The reaction product was dehydrated and tL.

The X-ray diffraction pattern of the
has reached its peak.

Example 4 in & 10% aqueous calcium acetate solution 1,76~ and 1()% aqueous ammonium phosphate solution 0.79 K
92 and pH 8.5r with 40% ammonia water.
After c it, tl adjustment, glass beads 7 with a diameter of 1 mm
．． The sample was placed in a lint mill with a capacity of f/r 14 J using No. 6 glaze as a grinding medium, and stirred and ground at a rotational speed of 60 Orpm for 10 minutes. C after dehydrating and drying the resulting aqueous suspension
The a/p molar ratio was 1.61, and the X-ray diffraction pattern showed diffraction of hydroxyapatite.

Comparative Example 8 A diammonium phosphate aqueous solution was added to a calcium acetate aqueous solution in the same manner as in Example 4, and the pH was adjusted to 8.5 with ammonia water.
The prepared mixed solution was placed in a 141-volume →end mill without using any grinding material, and the rotation speed was 600 rp.
The mixture was stirred for 6 hours at m. The Ca/p molar ratio of the resulting water suspension 'll which was dehydrated and dried was 1.49, and
The line diffraction diagram showed a peak of hydroxyapatite (μ), indicating that the crystallinity of the product was low.

[Brief explanation of drawings]

￥81 The figure shows the method of the present invention shown in Example 1.
Figure 2 shows the X-ray diffraction pattern of hydroxyapatite.
An X-ray diffraction diagram of hydroxyapatite obtained in Comparative Example 1 is shown. (that's all)

Claims (1)

[Claims] (1) Water-i'HL An aqueous solution containing at least one of HL calcium and calcyano salt; 1. A method for producing hydroxyl abatai 1, which comprises reacting while grinding 1 gamma^^, or carrying out a reaction by grinding lζ1 after mixing.