JPH0690997A - Reaction relaxation method of powder material for cured body of calcium phosphate and production of cured body of calcium phosphate - Google Patents

Abstract

PURPOSE:To control the reactivity of the powder material with a simple operation by treating the powder material for the cured body of calcium phosphate contg. one kind of alpha-tricalcium phosphate or tetracalcium phosphate with high- temp. and high-pressure steam. CONSTITUTION:The powder material to be used contains the alpha-tricalcium phosphate or tetracalcium phosphate or the mixture composed thereof as an essential component and may further contain hydroxy apatite or beta-tricalcium phosphate in some cases and preferably contains the alpha-tricalcium phosphate and/or the tetracalcium phosphate at >=1/3 of the entire part. The compsn. is not sufficiently cured if the content of these components is <1/3 of the entire part of the powder material. The treatment with the high-temp. and high-pressure steam is preferably executed under the conditions of 1 to 60 minutes at 100 deg.C (0.1kg/cm<2>) to 140 deg.C (2.7kg/cm<2>). The long-time treatment is needed to exhibit the effect if the temp. is below 100 deg.C. The effect is remarkable but the simple treatment is difficult if the temp. exceeds 140 deg.C.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is useful as a method for relaxing the reactivity of a powder for a calcium phosphate-based hardened material and a bone filling material for medical or dental use using the powder whose reactivity is controlled by the method. The present invention relates to a method for producing a calcium phosphate-based cured product.

[0002]

2. Description of the Related Art Certain calcium phosphates, such as α-tricalcium phosphate, have hydration coagulation properties, and when mixed with an aqueous solution containing an acid such as citric acid, curing proceeds extremely quickly. Attempts to use the material as a bone filling material for medical or dental use have become very popular in recent years (for example, JP-A-59-88351, JP-A-59-182263, JP-A-60-36404, and JP-A-60-36404). 61
191606, 61-234868, 61-
236644, 62-72363, 62-83.
349 publication). In these methods, since the curing time is too fast and the exothermic reaction is large, it is required to alleviate the curing reaction. Therefore, the inventor of the present invention has disclosed that, in JP-A-1-100049, glycerin is used as a liquid agent,
It was proposed to control the reaction by adding sugars or sugar alcohols. In fact, the curing reaction is sufficiently alleviated by this method, but it has been clarified that the liquid agent to which the saccharide is added deteriorates when sterilized by autoclave, and its improvement has been desired.

[0003]

DISCLOSURE OF THE INVENTION The present invention is capable of controlling the reactivity of a powdery agent for a calcium phosphate-based cured product by a simple operation, and provides an acid aqueous solution containing no additive for controlling the reactivity as a liquid agent. It is an object of the present invention to provide a method capable of producing a cured product by using a mild reaction.

[0004]

Means for Solving the Problems The reaction relaxation method for a powdered calcium phosphate-based hardener according to the present invention comprises at least one of α-tricalcium phosphate and tetracalcium phosphate.
It is characterized in that the calcium phosphate-based hardened powder containing seeds is treated with high-temperature high-pressure steam.

The powder used in the present invention contains α-tricalcium phosphate, tetracalcium phosphate or a mixture thereof as an essential component, and optionally further contains hydroxyapatite or β-tricalcium phosphate. However, it is preferable that the amount of α-tricalcium phosphate and / or tetracalcium phosphate is 1/3 or more of the total amount. If the amount of these components is less than 1/3 of the whole powder, the composition will not be sufficiently cured. When hydroxyapatite or β-tricalcium phosphate is added, the strength of the cured product is improved, so it is preferable to use a powder agent containing these. When a mixture of two or more calcium phosphates is used as a powder, the mixing ratio of the components is not particularly limited. Also, these powder components may not be completely pure and may contain small amounts of impurities generated during synthesis.

[0006] The powder is specifically α-tricalcium phosphate, tetracalcium phosphate, a mixture of α-tricalcium phosphate and tetracalcium phosphate, a mixture of α-tricalcium phosphate and hydroxyapatite, A mixture of tetracalcium phosphate and hydroxyapatite,
A mixture of tetracalcium phosphate and β-tricalcium phosphate, a mixture of α-tricalcium phosphate and β-tricalcium phosphate, a mixture of α-tricalcium phosphate, tetracalcium phosphate and hydroxyapatite or α Preferably it consists of a mixture of tricalcium phosphate, tetracalcium phosphate and β-tricalcium phosphate.

As the α-tricalcium phosphate used in the powder, calcium pyrophosphate obtained by heating calcium carbonate and calcium hydrogen phosphate dihydrate for 2 hours at 550 ° C. by a known dry method is used. It can be produced by reacting at 1 ° C. for 1 hour, or by reacting phosphoric acid with calcium hydroxide by a wet method and firing at a temperature of 1120-1180 ° C. or higher.
Also, β-tricalcium phosphate is produced by reacting calcium carbonate and calcium pyrophosphate at 1000 ° C. by a known dry method, or by wet method by reacting phosphoric acid and calcium hydroxide at 800 ° C. It can be manufactured by firing for 1 hour. The method for producing α-tricalcium phosphate and β-tricalcium phosphate,
The firing temperature after the reaction is different. The temperature at which the β-state changes to the α-state is 1120-1180 ° C.

Tetracalcium phosphate can be produced by a dry method in which calcium carbonate and calcium pyrophosphate are reacted at 1500 ° C. Hydroxyapatite can be produced by a dry method in which calcium carbonate and calcium pyrophosphate are reacted in steam, or a wet method in which phosphoric acid and calcium hydroxide are reacted.

The powder mixture of α-tricalcium phosphate and tetracalcium phosphate has a Ca / P ratio of 1.5 by the thermal decomposition method.
Calcium phosphate having a temperature of more than 1.8 and not more than 1.8 is calcined at a temperature of 1150 ° C. to 1450 ° C. under reduced pressure (JP-A-62-172445) or hydroxyapatite obtained by a wet synthesis method in air. It can be manufactured by firing at 1500 ° C. for 24 hours. The mixed powder of α-tricalcium phosphate and tetracalcium phosphate can also be prepared by mixing separately synthesized α-tricalcium phosphate and tetracalcium phosphate. Further, the mixed powder of α-tricalcium phosphate, tetracalcium phosphate and hydroxyapatite can be prepared by stopping each of the above decomposition methods or by mixing three separately synthesized components.

Further, the mixed powder of α-tricalcium phosphate and hydroxyapatite has a Ca /
Calcium phosphate having a P ratio of more than 1.5 and less than 1.67 is 1000 ° C. or higher, preferably 1150 ° C. to 1450 ° C.
It is obtained by firing at the above temperature or by mixing separately synthesized α-tricalcium phosphate and hydroxyapatite (JP-A-59-182263).

The mixed powder of tetracalcium phosphate and hydroxyapatite is prepared by mixing separately synthesized tetracalcium phosphate and hydroxyapatite. Similarly, a mixed powder of tetracalcium phosphate and β-tricalcium phosphate is prepared by mixing separately synthesized tetracalcium phosphate and β-tricalcium phosphate (JP-A-59-182263). Issue).

Further, the mixed powder of α-tricalcium phosphate and β-tricalcium phosphate reacts with phosphoric acid and calcium hydroxide to produce a mixture of α-tricalcium phosphate and β-tricalcium phosphate at a temperature Or by mixing separately synthesized α-tricalcium phosphate and β-tricalcium phosphate.

A mixed powder of α-tricalcium phosphate, tetracalcium phosphate and β-tricalcium phosphate is a mixture of α-tricalcium phosphate and tetracalcium phosphate produced by the above-mentioned thermal decomposition method, The β-tricalcium phosphate synthesized alone is mixed, or the mixture of α-tricalcium phosphate and β-tricalcium phosphate is mixed with tetracalcium phosphate synthesized alone, or each is independently mixed. It can be prepared by mixing the three components synthesized in.

The calcium phosphate powder used in the present invention may contain various metal oxides, metal fluorides, antibacterial agents, etc., but these additives must be those which are not deteriorated by the treatment in the present invention. .

In the reaction relaxation method according to the present invention, the above dust is treated with high temperature and high pressure steam. The treatment conditions with high-temperature high-pressure steam vary depending on the type of powder, the desired curing time when kneading with a liquid and the reaction temperature, and the curing time when kneading with a liquid is higher as the treatment temperature is higher. ,
The longer the treatment time, the longer the treatment tends to be. The reaction temperature tends to be lower as the treatment temperature is higher and the treatment time is longer. Therefore, the treatment conditions may be appropriately determined in consideration of the desired curing time and reaction temperature, but generally, the treatment is performed at 100 ° C. (0.1 kg / cm ² ) to 140 ° C.
It is preferable to carry out at 60 ° C. (2.7 kg / cm ² ) for 1 to 60 minutes. If the temperature is lower than 100 ° C., it takes a long time to exert the effect, and if the temperature is higher than 140 ° C., the effect is remarkable and the treatment is difficult to perform easily.

The treatment with the high-temperature and high-pressure steam in the present invention is usually carried out in an autoclave, and as the autoclave, a medical high-pressure steam sterilizer is particularly suitable.

When the powder agent treated by the reaction relaxation method of the present invention is kneaded with a liquid agent, the curing reaction proceeds gently. Therefore, the present invention further provides a method for producing a calcium phosphate-based cured product, which comprises treating the powdered product as described above and kneading with the liquid agent for the cured product.

The aqueous acid solution used as a liquid agent in the present invention may contain various inorganic and organic acids dissolved in water. Examples of the acid include inorganic acids such as phosphoric acid, or acetic acid, lactic acid, citric acid, malic acid, malonic acid,
Organic acids such as succinic acid, glutaric acid, tartaric acid and polyacrylic acid can be mentioned. In the present invention, the amount of these acids is preferably 10% by weight or more, more preferably 10 to 55%.
Used as an aqueous solution with an acid concentration of wt%. If the acid concentration of the acidic aqueous solution is less than 10% by weight, the cured product obtained by mixing with the powder does not exhibit desired strength. Preferred aqueous acid solutions include, for example, a citric acid solution having an acid concentration of about 45% by weight, a malic acid solution having an acid concentration of about 40% by weight, a phosphoric acid solution having an acid concentration of about 40% by weight and about 25% by weight. It is a polyacrylic acid solution having an acid concentration of.

Since the powder agent after being treated with the high-temperature and high-pressure steam is usually solidified, it is preferable to grind it in a mortar or the like and then knead it with the liquid agent in order to mix it uniformly. Further, since heat is generated during curing, it is preferable that the powder agent treated with the high temperature and high pressure steam is allowed to cool to room temperature and then kneaded with the liquid agent. The kneading ratio of the powder agent and the liquid agent is preferably such that the compounding amount (P / L) of the powder agent with respect to the liquid agent is 0.4 to 2.7 in weight ratio. If this ratio is less than 0.4, the strength of the obtained cured product will be weak because the solid content is small, while 2.7
If it exceeds, it becomes difficult to uniformly knead the powder agent and the liquid agent.

[0020]

The mechanism by which the curing reaction proceeds mildly by treating the powder with high temperature and high pressure steam according to the present invention is not clear, but a part of the powder reacts by this treatment, and it actually becomes liquid. It is thought that this is because the active portion is reduced when kneading.

[0021]

EXAMPLES Next, the present invention will be described more specifically based on examples, but the present invention is not limited thereto.

Example 1 Hydroxyapatite having a Ca / P ratio of 1.67 synthesized by a wet method was spray-dried and then 1.3 × 10 ⁻⁴ P at 1200 ° C.
Vacuum decomposition was carried out for 1 hour at a to obtain a mixture of α-tricalcium phosphate and tetracalcium phosphate. The powder obtained by agglomeration in a mortar was used as a powder, and 2 g of this powder was placed in a polypropylene container (capacity: 10 ml) and autoclaved at 121 ° C. for 20 minutes (Stearimite 1 manufactured by Hirayama Seisakusho Co., Ltd.).
8A). After standing for 15 minutes, the treated powder is crushed with a Teflon rod, and then 45% citric acid aqueous solution 1
When kneaded with g, it hardened after about 20 minutes. During this time, it could be formed into any shape by hand. The maximum temperature reached during curing was about 44 ° C. In this example, it is considered that the curing time was further lengthened because the powder having a wide particle size distribution, that is, the non-classified powder was used.

Examples 2 and 3 Hydroxyapatite having a Ca / P ratio of 1.67 synthesized by a wet method was spray-dried and then 1.3 × 10 ^-4 P at 1200 ° C.
The mixture was vacuum decomposed at a for 3 hours to obtain a mixture of α-tricalcium phosphate and tetracalcium phosphate. Particle size 10-25μ
Using m of m as a powder, 2 g of this powder was placed in a glass beaker and treated under the following conditions. After standing for 15 minutes, the powder was pulverized with a Teflon rod, kneaded with 1 g of a 45% citric acid aqueous solution, and the time required for curing and the maximum temperature (reaction temperature) reached during curing are shown in Table 1. In addition, each experiment was measured using two samples, and the results are shown in Table 1 as an average value.

Treatment conditions 1) Group for high temperature treatment with dry heat for 20 minutes 115 ° C 121 ° C 133 ° C 2) Group for treatment at 121 ° C for different time in autoclave 5 minutes 20 minutes 40 minutes 3) Change temperature with autoclave Group treated for 20 minutes 115 ° C 121 ° C 133 ° C 4) Control (untreated powder)

[0025]

[Table 1]

As is clear from the above results, the dry heat treatment showed a slight decrease in the reaction temperature as compared with the control, but hardly any change in the curing time, and the curing time and the reaction depending on the treatment temperature. No effect on temperature was observed. On the other hand, in the autoclaved group, if the temperature is constant, the longer the treatment time is, the longer the curing time is, and the reaction temperature tends to decrease. The higher the temperature was, the longer the curing time was extended, and the lower the reaction temperature was.

Example 4 1200 a hydroxyapatite was used as the raw material powder.
The mixture was vacuum decomposed at 1.3 × 10 ⁻⁴ Pa at 40 ° C. for 40 minutes to obtain a mixed powder containing α-tricalcium phosphate, tetracalcium phosphate and hydroxyapatite in a ratio of 2: 1.2: 1. . Of these, those that passed through a 37 μm sieve were used, and this powder was treated under the following conditions. 45 as liquid agent
% Citric acid aqueous solution was used to cure at P / L = 2 g / 1 g. Table 2 shows the time required for curing and the maximum temperature (reaction temperature) reached during curing.

1) Autoclave at 121 ° C. for different treatment time 5 minutes 20 minutes 2) Autoclave at different temperature for 20 minutes treatment group 115 ° C. 121 ° C. 3) Control (untreated powder)

Example 5 A mixture of α-tricalcium phosphate synthesized by a known method and hydroxyapatite in a ratio of 4: 1 was used as a dusting agent, and this was treated in an autoclave at 121 ° C. for 20 minutes. Use a 45% citric acid aqueous solution as a liquid agent,
It was cured at P / L = 1.5 g / 1 g. Table 2 shows the time required for curing and the maximum temperature (reaction temperature) reached during curing.

[0030]

[Table 2]

[0031]

EFFECTS OF THE INVENTION According to the method of the present invention, it is possible to control the reactivity of the powder agent by a simple operation without requiring any additive in the liquid agent, and to adjust it to a desired curing time. The temperature can also be reduced. Therefore, when a powdery agent whose reactivity is moderated by the method of the present invention is kneaded with an aqueous acid solution, the curing time is significantly prolonged and the reaction temperature is low compared to the conventional method, and therefore, it is manually molded into an arbitrary shape during curing. be able to.

Claims (6)

[Claims] 1. A powdered calcium phosphate-based hardener comprising at least one of α-tricalcium phosphate and tetracalcium phosphate, which is treated with high-temperature high-pressure steam. Reaction relaxation method. 2. Treatment with high temperature and high pressure steam at 100 ° C. (0.
The method for relaxing the reaction of a powdery agent for a calcium phosphate-based cured product according to claim 1, which is carried out at 1 kg / cm ² ) to 140 ° C. (2.7 kg / cm ² ) for 1 to 60 minutes. 3. A calcium phosphate-based hardener powder containing at least one of α-tricalcium phosphate and tetracalcium phosphate is treated with high-temperature high-pressure steam,
A method for producing a calcium phosphate-based cured product, which comprises kneading with a liquid agent for a cured product. 4. The treatment of powder with high temperature and high pressure steam for 100 times.
1 ° C (0.1kg / cm ² ) to 140 ° C (2.7kg / cm ² )
The method for producing a calcium phosphate-based cured product according to claim 3, which is performed for 60 minutes. 5. The method for producing a calcium phosphate-based cured product according to claim 3, wherein the liquid agent is an aqueous solution of an inorganic acid or an organic acid. 6. The method for producing a calcium phosphate-based cured product according to claim 5, wherein the liquid agent is an aqueous citric acid solution.