JPH03159946A - Calcium quaternary phosphate cured form and production thereof - Google Patents

Abstract

PURPOSE:To obtain the title cured form with stabilized quality by admixing Ca4(PO4)2 powder produced by (half) malting a mixture of a Ca source material, P source material powder and Al compound with silica - alumina-based noncrystalline glass powder and a specific polyacrylic acid. CONSTITUTION:A mixture of a Ca source material <=20mum in granular size (e.g. CaCO3) and a P source material <=20mum in granular size (e.g. CaHPO4) at the molar ratio Ca/P=2 is incorporated with 0.005-5 pts.wt., on an Al2O3 basis, of an aluminum compound (e.g. Al2O3) based on 100 pts.wt. in the theoretical amount to be formed of Ca4(PO4)2, followed by (half) melting at >=1400 deg.C into Ca4(PO4)2 powder. Thence, a powder mixture of 100 pts.wt. of the above powder and 0.005-50 pts.wt. of silica - alumina-based noncrystalline glass powder is admixed with 30-60wt.% of an endogenous acid or a polyacrylic acid of the formula (n is 1000-100000).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hardened tetracalcium phosphate material useful as an artificial bone material, a dental polishing material, etc., and a method for producing the same.

In this specification, the term ``molten state'' refers to a state in which the raw material powder becomes fluid as a result of being heated, and the term ``semi-molten state'' refers to a state in which the raw material powder is heated and becomes fluid as a whole. , refers to a state in which powder particles have apparently disappeared and formed a homogeneous phase, although they have not yet reached the point of fluidity.Furthermore, "porous state" refers to a state in which the raw material powder is heated and each powder particle reacts with each other. However, each powder particle does not completely lose its shape and remains almost unchanged.

Furthermore, in this specification, "parts" and "%" represent "parts by weight" and "% by weight," respectively.

Prior art and its problems Tetracalcium phosphate (Ca4(PO4)201) is a type of phosphoric acid compound that is a major inorganic component of bones, teeth, etc.It has high chemical activity and is an inorganic acid at room temperature. , saturated and unsaturated organic acids, homopolymers and copolymers of unsaturated organic acids, aqueous solutions thereof, physiological saline, etc., and have the property of easily reacting and curing. The body is biocompatible and useful as artificial bone material, dental material, etc.

Conventionally, as raw materials for producing tetracalcium phosphate, CaCO3, Cab, Ca(OH)2, etc. have been used as Ca sources, and P205, H3PO4, NH4H2PO4, (NH4) have been used as P sources.
)2HP04, etc. are used, and furthermore, CaHPO4, Ca(H2PO4)2, etc. are used as Ca and P sources. There are various methods for producing tetracalcium phosphate depending on the raw materials used, but CaCO3 powder and C
The most common method is the dry manufacturing method described below, in which the powder is mixed with a HPO4 powder and fired.

2CaCO3 +2CaHPO4 - Ca4 (PO4)2 0+2CO2 +H2 0 In this method, the raw powder mixture must be fired at a temperature of about 1300 to 1600°C, and then rapidly cooled to about 400°C (cooling rate of about 10°C/min or more). and obtained a mixture of phosphoric acid compounds containing a large amount of tetracalcium phosphate. In this method, when the firing temperature is set to 1600° C. or higher, the product forms a mixed phase of porous portions and semi-molten portions, causing a problem of variations in quality of tetracalcium phosphate. Furthermore, even if the firing temperature is in the temperature range of 1,300 to 1,600 degrees Celsius, the obtained tetracalcium phosphate is highly reactive and very unstable. Hydroxyapatite is easily produced by absorbing atmospheric water vapor in the temperature range of ~400°C. Therefore, in this method, in order to increase the yield of tetracalcium phosphate and obtain a product with stable quality, the firing temperature, the moisture content in the atmosphere in the firing furnace during cooling,
It is necessary to strictly control the cooling rate, etc.

However, removing moisture from the atmosphere inside the firing furnace is
This is difficult in actual operation. Furthermore, forcibly cooling the product in the furnace is not only technically difficult, but also causes damage to large furnace wall components due to rapid cooling.

Means for Solving the Problems As a result of intensive research in view of the current state of the technology as described above, the present inventor has developed a raw material mixture to which a specific amount of an aluminum compound has been added to a semi-molten or molten state. It has been found that the problems of the prior art are greatly reduced or substantially eliminated when heating is carried out at . It has also been found that the cured product obtained from tetracalcium phosphate obtained in this manner also has physical properties that are superior to, but not inferior to, conventional products.

That is, the present invention provides (1) the following cured tetracalcium phosphate and their production method: (1) calcium source material powder and phosphorus source so that Ca/P=2 (molar ratio); Blend the material powder, and further add 0.005 to 5 parts of aluminum compound as AQ203 to 100 parts of theoretical production amount of tetracalcium phosphate,
After producing tetracalcium phosphate by semi-melting or melting at a temperature of 0°C or higher, 100 parts of the obtained tetracalcium phosphate powder and 0 parts of silica-alumina amorphous glass powder
．． 005 to 50 parts of the powder mixture, 30 to 60% of the weight of the powder mixture is mixed with an internal acid or a polyacrylic acid represented by 6 (CH,,-CH}n COOH (n is 1000 to 100000). A method for producing a cured tetracalcium phosphate product, characterized by:

■ A cured tetracalcium phosphate obtained by the production method described in the above item ■.

In the present invention, the raw materials for producing tetracalcium phosphate may be the same as those used in the conventional method described above. However, when using the produced tetracalcium phosphate as a biomaterial, it is necessary to use substances that are approved as food additives from the viewpoint of safety, such as CaH.
PO4, CaHPO4・2H2 0, CaCO3, Ca
3 (PO4)2 and the like are preferably used. These are usually used as powders of 20 μm or less, with an average size of about 5 μm.

In addition, the aluminum compounds added to the raw materials for producing tetracalcium phosphate are AQ203, AQ (
OH)3, AQ (PO)a, AQPOa, AQ(
H2 PO4 )3 , AQ B2 , AQCI23,
AQF3, AQI3, AQ2 (SiO3)3, AR2
(804)3, AQ2 Ti05, etc. are exemplified, and these may be used alone or in combination of two or more. Among these, AQ203 is more preferable from the viewpoint of uniformity of fired products, adjustment of firing temperature, color tone of raw wood, etc. The aluminum compound is also used as a powder, usually 20 μm or less, with an average size of about 5 μm.

In the present invention, such raw materials are blended so that the molar ratio of Ca/P is 2, and an aluminum compound is added to AQ203 for 100 parts of the theoretical amount of tetracalcium phosphate produced from this raw material blend. as 0.005~5
After adding 100% of the total amount of carbon dioxide and firing at a temperature of 1400° C. or higher to semi-melt or melt, the mixture is allowed to cool naturally in a furnace. The cooling rate can vary widely depending on the amount of raw material used, the capacity and structure of the furnace, etc., but in any case, the cooling rate is 10°C/10°C as in the conventional method.
This is extremely slow cooling compared to rapid cooling of more than a minute. When firing, if the raw material powder mixture containing all of the above components is shaped to the extent that it does not disintegrate and is semi-molten, a container for storing the raw material powder mixture and the fired product is not required, and handling is easy. This is advantageous because the volume inside the firing furnace can be used effectively. A more preferable addition amount of the aluminum compound to 100 parts of theoretical production of tetracalcium phosphate is about 1 to 2 parts as AQ203, and a more preferable baking temperature is about 1500 to 1.
The temperature is 550°C.

Figure 1 shows the amount of AQ203 added to a raw material mixture with a molar ratio of Ca/P of 2 (the amount added to 100 parts of the theoretical amount of tetracalcium phosphate to be produced), the calcination temperature, and the semi-molten and molten states. Indicates the relationship between From FIG. 1, it is clear that the semi-molten and molten states can be adjusted quite freely depending on the amount of 9A (2203).For example, AQ20
If the blending amount of No. 3 is 5%, a semi-molten product can be obtained by setting the firing temperature to about 1450°C.

In addition, Fig. 2 shows the amount of AQ203 added to a raw material mixture with a molar ratio of C a / P of 2 (the amount added to 100 parts of the theoretical amount of tetracalcium phosphate to be produced);
The relationship between the firing temperature and the proportion of tetracalcium phosphate in the raw wood is schematically shown.

If the amount of AQ203 exceeds 5%, only hydroxyapatite will be formed, so it is clear that the amount of AQ203 should be 5% or less.

The tetracalcium phosphate obtained as described above is very hard and compacted, and almost no conversion into hydroxyapatite occurs. In addition, tetracalcium phosphate obtained by conventional firing methods is usually grayish white in color, but depending on the type of raw materials used, the influence of trace impurities, etc., the fired product may be partially or completely dark-colored, or
In many cases, the material is colored grayish-green and loses its value as a biomaterial from an aesthetic point of view. However, AQ20
Tetracalcium phosphate obtained by the method of the present invention by blending 3 is not affected by the type of raw materials used or trace impurities, and is uniformly colored from light blue to light blue as a whole and is beautiful.

The properties of the tetracalcium phosphate according to the present invention can be improved by further adding other additives to the raw material mixture. For example, in order to impart X-ray contrast properties, antibacterial properties, etc. to tetracalcium phosphate, B a
804, B a CO3, S r SO 4 , S
r Alkaline earth metal compounds such as C 0 3, Ba
S i F6 , SnF2 , CaF2, NaF, AQ
One or more fluorine-containing compounds such as F3, Na2, SiF6, etc. can be added. These optional additives are AQ20
It can be used in place of up to about 60% of the aluminum compound as No. 3. These optional additives are also used in the form of powder, usually 20 μm or less, with an average size of about 5 μm.

The cured product of tetracalcium phosphate according to the present invention is obtained by adding the powder mixture to a powder mixture consisting of 100 parts of the tetracalcium phosphate powder produced by the above method and 0.005 to 50 parts of a silica-alumina amorphous glass powder. 30-60 of the market amount
% of body acid or polyacrylic acid represented by the following formula (a) (CH2 CH}o (a) COOH (n is 1000 to 100000).

Silica-alumina amorphous glass is produced by melting and rapidly cooling raw materials that contain silica and alumina as the main components and may also contain small amounts of calcium, fluorine, sodium, phosphorus, titanium, strontium, etc. It is used after being vitrified and crushed.

When the amount of the silica-alumina amorphous glass powder is less than 0.005 parts with respect to 100 parts of the tetracalcium phosphate powder, almost no effect is observed by the addition. On the other hand, 50
If the strength exceeds 50%, there is almost no improvement in strength, or there is a tendency for the strength to decrease. The amount of the silica-alumina amorphous glass powder is more preferably 8 to 15 parts. The particle size of the silica-alumina amorphous glass powder is
It is usually 10 μm or less, and the average is about 3 μm.

Examples of the internal acids used in the present invention include citric acid, malonic acid, malic acid, maleic acid, lactic acid, fumaric acid, ascorbic acid, succinic acid, gluconic acid, glutaric acid, and pyruvic acid. One or more acrylic acids can be used, if necessary, in the form of an aqueous solution.

The amount of these internal acids and polyacrylic acid used13 (as acid) is 30 to 60% of the total amount of electricity of tetracalcium phosphate powder and silica-alumina amorphous glass powder.
degree.

The tetracalcium phosphate hardened product obtained in this way has a large bulk specific gravity of the tetracalcium phosphate powder, so compared to conventional products, the bulk specific gravity itself is significantly larger and the crushing strength is also higher. .

Therefore, such a hardened product is useful as a biological material such as an artificial bone material or a Nanke material.

Effect of the invention According to the present invention, the following remarkable effects can be obtained.

(1) The operation of semi-melting or melting the raw material powder mixture eliminates the need for rapid cooling operations, dehumidification and drying in the firing furnace, etc., unlike conventional methods.

Therefore, a firing furnace with a special structure is not required, and manufacturing can be carried out using a normal firing furnace, thereby reducing manufacturing costs.

14 (2) The yield of tetracalcium phosphate is high, and the obtained tetracalcium phosphate has high purity.

(3) When firing a Ca source compound and a P source compound, they will not melt unless the temperature is about 1600° C. or higher, although it depends on the purity of the compounds used. On the other hand, the method of the present invention in which AQ203 is used in combination is advantageous in terms of energy since the semi-melting or melting temperature is significantly lowered.

(4)l! By using 203 in combination, the semi-melting temperature range is expanded, so variations between product lots and non-uniform composition of components inside the product are greatly reduced, resulting in a product with uniform and stable quality. .

(5) If only the Ca source compound and P source compound are fired,
Even if the product is less aesthetically pleasing, AEI! By using 203 in combination, a beautiful product uniformly colored from light blue to light blue can be obtained.

(6) The hardened tetracalcium phosphate obtained by this beating is 15 It has a large bulk specific gravity and high crushing strength.

EXAMPLES Examples and reference examples are shown below to further clarify the features of the present invention.

Reference example 1 Powdered CaCO3 and C a H with an average particle size of about 5 μm
P 0 4 is mixed at a molar ratio of 1:1, and further AQ
203 was added at a rate of 0.1% of the weight of the mixture and baked in a furnace at 1600°C in the atmosphere for 2 hours to semi-melt it, then allowed to cool naturally in the furnace, and when the temperature dropped to 400°C. It was taken out of the furnace.

The X-ray diffraction results of the product are shown in the upper part of FIG.

From the mucilage in Figure 3 it is clear that the product consists essentially of tetracalcium phosphate.

Comparative Reference Example 1 The same operation as in Example 1 was performed except that the firing temperature was 1500°C. The product was porous for 1 h.

The results of X-ray diffraction of the product are shown in the lower part of Figure 3.

From the results shown in Figure 3, it is clear that the product contains a large amount of hydroxyapatite in addition to tetracalcium phosphate.

Reference Example 2 The same operation as in Reference Example 1 was performed except that the amount of AQ203 added was in the range of 0.005 to 50% and the firing temperature was in the range of 1350 to 1600°C.

The X-ray diffraction results of the product are shown in Figures 4A-F.

The relationship between FIG. 4 A to F, the amount of A92Ch added, and the firing temperature is as follows.

■． Figure 4 A AQ2 03: 50% Firing temperature: 1B50°C ■. Figure 4B AR203: 20% Firing temperature: 1400°C 17 ■. Figure 4 C Al22 03: 10% Firing temperature: 1450°C ■. Figure 4 D AQ2 03: 5% Firing temperature: 1450°C ■. Figure 4 E AQ203: 1.5% Firing temperature: 1500℃ ■. Figure 4 F A122 03: 0.005% Firing temperature: 1600°C From the results shown in Figure 4 A-F, the amount of AQ203 added was 5%.
If it is below, the effect of the melting temperature will be significant and tetracalcium phosphate will also be produced satisfactorily. However, AQ20
Even if 5% of 3 was added twice, no significant drop in the melting temperature would be observed, and on the contrary, it would damage the production of tetracalcium phosphate. The amount to be added is 5% with a limit of 42.

Example 1 Silica-alumina amorphous glass powder (silica 50%,
After adding 10, 20 or 30 parts of 30% alumina and 20% trace components such as SrSTi and Ca,
For 100 parts of the obtained mixed powder, add 45% citric acid, 45% malic acid, or 30% malic acid and polyacrylic acid (
Fifty parts of an aqueous solution containing 15% of n=approximately 16,000 in the above formula (a) was added as an acid to obtain a cured product.

On the other hand, for comparison, a cured product was obtained in the same manner as in Section 2, except that a conventional tetracalcium phosphate powder containing no AQ203 was used.

The crushing strength of each cured product after 24 hours was as shown in Table 1.

In Table 1, each symbol represents the following.

Use of alumina-based glass powder m = A... 10 parts of silica Mouth... 30 parts of silica C... 50 parts of silica 2... Aqueous citric acid solution H... To aqueous malic acid solution... 10 parts of malic acid Use of polyaqualumina glass powder m = Amount of alumina glass powder used = Rilic acid 1'-J Condolence 1 Table Conventional product A 653 810
803 units 621 773
781580 751 766 Example A 1035 1260 11
24 shares 833 978
1031ha 720 880
893 The crushing strength of the cured tetracalcium phosphate obtained by the present invention is approximately 1.5 times that of conventional tetracalcium phosphate cured in the same manner.

[Brief explanation of the drawing]

Figure 1 shows a raw material arrangement with a molar ratio of Ca/P of 2.
;! This is a graph showing the relationship between the addition amount of AR2 (h), the calcination temperature, and the semi-molten and molten states for the 1 z U compound. 3 is a graph showing the relationship between the amount of addition of X, the firing temperature, and the percentage of raw tetracalcium phosphate in the product. This is a chart showing the results of ray diffraction measurements. Figure 4 is a chart showing the results of X-ray diffraction measurements of each product obtained in Reference Example 2. (Above) 9'2

Claims (2)

[Claims] (1) Blend calcium source material powder and phosphorus source material powder so that Ca/P = 2 (molar ratio), and further add 0 parts of aluminum compound (as Al_2O_3) to 100 parts of theoretical production amount of tetracalcium phosphate. After producing tetracalcium phosphate by adding .005 to 5 parts and semi-melting or melting at a temperature of 1400°C or higher, 100 parts of the obtained tetracalcium phosphate powder and silica-alumina amorphous glass A powder mixture consisting of 0.005 to 50 parts of powder has an internal acid content of 30 to 60% of the weight of the powder mixture or polyacrylic acid represented by ▲Numerical formula, chemical formula, table, etc.▼ (n is 1000 to 100000) A method for producing a hardened tetracalcium phosphate product, which comprises mixing an acid. (2) A cured tetracalcium phosphate obtained by the production method according to claim (1).