JPH0774084B2 - Method for producing inorganic biomaterial - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an inorganic biomaterial useful as an implant material such as an artificial bone or an artificial tooth root.

[Prior Art] Ceramics have attracted attention as biomaterials because they are less harmful to living organisms than polymer materials and metal materials, and their progress has been remarkable in recent years. Some of the ceramics form chemical bonds with bones,
Bioactive ones are known. Since this is integrated with the living body, loosening does not occur. Bioactive ceramics include apatite sintered [Ca
₁₀ (PO ₄ ) ₆ OH ₂ ] or apatite crystals [Ca ₁₀ (PO ₄ ) ₆ (O
Crystallized glass in which _0.5 , F) ₂ ] and wollastonite crystals [CaSiO ₃ ] are precipitated is known. However, the bending strength of these ceramics is 1000 to 1400 kg / cm ² for apatite sintered body and 1200 to 2300 kg / c for crystallized glass.
It is about m ² . Therefore, in order to increase the strength, a material in which bioactive crystallized glass and zirconia-based or alumina-based ceramics are composite-crystallized has been developed (Japanese Patent Laid-Open Nos. 62-231668 and 63-82670). . These composite materials have a relatively high bending strength of 2300 to 3500 kg / cm ² , but they are not always sufficiently satisfactory as artificial bones or artificial roots, so their use is still unclear. It is quite limited.

As a method for obtaining a material having higher strength, Japanese Patent Application Laid-Open No. HEI-1
No. 115360, a glass powder having a particle size smaller than 75 μm and a zirconia-based powder having a particle size smaller than the glass powder are mixed, and the mixture is molded into a predetermined shape. The method of sintering the zirconia-based powder after sintering and crystallizing the glass portion of the above is disclosed.

[Problems to be Solved by the Invention] The method described in JP-A-1-115360 is effective when the amount of zirconia-based powder is large, but when the amount of zirconia-based powder is small, glass is used. When the temperature of the powder reaches the sintering temperature, the glass flows to surround the zirconia-based powder, or at the place where the glass does not flow well, pores are often formed near the interface between the glass and the zirconia-based powder. . Then, when the temperature reaches the temperature at which crystallization subsequently occurs, the flow of the glass stops and crystallization starts, and the state of, is maintained as it is. Therefore, when the temperature at which the zirconia-based powder is sintered is reached,
In the area of the above condition, the zirconia-based powders cannot be sintered together, and the skeleton of the zirconia-based ceramics exhibiting high strength cannot be formed, so that a high-strength composite material cannot be obtained. Further, at the location of the state of (3), since the pores remain in the composite material as they are, a high-strength material cannot be obtained.

Therefore, in the above method, the amount of crystallized glass that contributes to bioactivity must be made smaller than the amount of zirconia-based ceramics as a reinforcing material, so bioactivity must be sacrificed, and it binds to bone. There was a drawback that it took a considerable amount of time.

Therefore, an object of the present invention is to solve the above-mentioned drawbacks of the conventional method and to provide a method capable of producing an inorganic biomaterial having high strength and excellent bioactivity.

[Means for Solving the Problems] The present invention has been made to achieve the above object, and the method for producing an inorganic biomaterial of the present invention is characterized by comprising the following series of four steps. .

Step 1. By melting and cooling the glass raw material mixture,
By weight percentage, CaO 12 to 56% P ₂ O _{5 1 to} 27% SiO ₂ 22 to 50% MgO 0 to 34% A 1 ₂ O ₃ 0 to 25%, containing the above components, CaO, P ₂ O ₅ , SiO ₂ , MgO and A1 ₂
A step of obtaining glass having a composition in which the total content of O ₃ is 90% or more.

Step 2. The temperature range in which the glass obtained in Step 1 is precipitated with apatite and one or more kinds of alkaline earth silicate crystals selected from wollastonite, diopside, forsterite, akermanite and anorthite. Process to obtain crystallized glass by heat treatment in.

Step 3. A step in which the crystallized glass obtained in Step 2 is crushed at the same time or after crushing, and then mixed with zirconia-based and / or alumina-based powder to obtain a mixed powder.

Step 4. A step of molding the mixed powder obtained in step 3 into a predetermined shape and then heat-treating it in the sintering temperature range of zirconia-based powder and / or alumina-based powder to obtain an inorganic biomaterial composed of ceramic composite crystallization.

Hereinafter, the method for producing an inorganic biomaterial of the present invention will be described step by step.

First, in step 1, as described above, the glass raw material mixture is melted,
By cooling, in weight percent, contain the ingredient in the range of _{CaO 12~56% P 2 O 5 1~27} % SiO 2 22~50% MgO 0~34% A1 2 O 3 0~25%, CaO, P ₂ O ₅ , SiO ₂ , MgO and A1 ₂
It is a step of obtaining a glass having a composition in which the total content of O ₃ is 90% or more.

The reason why the composition of the glass obtained in step 1 is quantitatively limited is as described below.

If CaO is less than 12%, apatite crystals [Ca ₁₀ (PO ₄ )
₆ (O _0.5 , F) ₂ ] is extremely reduced in precipitation amount, and the devitrification tendency becomes severe. If CaO exceeds 56%, the glass tends to devitrify significantly. Therefore, the CaO content is 12-56%
Limited to When P ₂ O ₅ is less than 1%, the devitrification tendency of the glass is remarkable, and when it exceeds 27%, wollastonite [CaOSi
O ₂ ], diopside [CaO MgO 2SiO ₂ ], forsterite [2MgO SiO ₂ ], akermanite [2CaO MgO 2Si
O ₂ ], anorthite [CaO A1 ₂ O _{3 2} SiO ₂ ] and other alkaline earth silicate crystals are less precipitated, so the content of P ₂ O ₅ is limited to 1 to 27%. When SiO ₂ is less than 22%, the amount of alkaline earth silicate crystals deposited is small. Also SiO ₂
If it exceeds 50%, the glass tends to devitrify. Therefore,
The SiO ₂ content is limited to 22-50%. MgO is not an essential component, but diopside crystals, forsterite crystals,
Used when precipitating akermanite crystals. If the amount is more than 34%, the amount of apatite crystals produced is small and devitrification is likely to occur, so the amount is limited to 34% or less. Similarly, A1 ₂ O ₃ is not an essential component, but is used when anorthite crystals are precipitated. If the amount is more than 25%, the amount of apatite crystals produced is small and devitrification is likely to occur, so the amount is limited to 25% or less.

In addition to the above 5 components, glass is not harmful to humans
K ₂ O, Li ₂ O, Na ₂ O, TiO ₂ , ZrO ₂ , SrO, Nb ₂ O ₅ , Ta ₂ O ₅ , B ₂ O ₃ , Y
₂ O _3, fluorine can contain one or more in the range of 10%. When the total amount of these optional components is more than 10%, the production amount of apatite crystals and alkaline earth silicate crystals (wollastonite, diopside, forsterite, anorthite) may be reduced, so it is preferable. It should be 10% or less. However, when the F ₂ conversion value of fluorine is more than 5%, the glass tends to devitrify, and when Y ₂ O ₃ is more than 5%, the amount of apatite crystals and alkaline earth silicate crystals is reduced. Therefore, each of fluorine and Y ₂ O ₃ is limited to 5% or less.

The glass having the above composition in Step 1 is the metal oxide itself and the corresponding carbonate constituting the glass,
Raw materials consisting of phosphates, hydrates, fluorides, etc. at 1300 ℃
It is obtained by melting by heating above and then cooling.

Next, in step 2, the glass obtained in step 1 is precipitated with apatite and one or more kinds of alkaline earth silicate crystals selected from wollastonite, diopside, forsterite, akermanite, and anorthite. It is a step of obtaining a crystallized glass by heat-treating in the temperature range.

When the glass obtained in step 1 is heated from room temperature and the glass transition temperature is exceeded, the glass tends to flow and sintering of the glass starts. When the heating temperature is further raised, crystallization of glass begins. Even if the crystallized glass is heated again, the sintering hardly progresses. These phenomena can be confirmed by differential thermal analysis of glass. Generally, the sinterability of the glass can also be controlled by controlling the progress of crystallization by the heat treatment temperature and the time, but in step 2, the crystallization of the glass is sufficiently performed so that the glass is not re-sintered. Is preferred. This is to fully utilize the sinterability of the zirconia-based powder and / or the alumina-based powder in the subsequent step 4.

The precipitation temperature range of the apatite crystals and the alkaline earth silicate crystals can be obtained by, for example, differential thermal analysis of glass. By analyzing the X-ray diffraction data of the glass powder heat-treated at the temperature of the exothermic peak in the differential thermal analysis curve, the precipitated crystals corresponding to the respective exothermic peaks were identified, and the temperature from the exothermic temperature to the exothermic end temperature was determined. The temperature is set to the crystal precipitation temperature range. The precipitation temperature range of these crystals is, for example, 750 to 1.
It is 260 ℃. In step 2, α- or β-type tricalcium phosphate crystal [Ca ₃ (PO ₄ ) ₂ ] is optionally precipitated in addition to the above crystals.

Next, step 3 is a step in which the crystallized glass obtained in step 2 is crushed at the same time or after crushing, and then mixed with zirconia-based and / or alumina-based powder.

Crushing of the crystallized glass is carried out by a known means such as a ball mill. The crystallized glass powder obtained has a particle size of 500.
μm or less is desirable. The reason is that if the obtained crystallized glass powder has particles larger than 500 μm, then the crystallized glass powder is mixed with zirconia-based and / or alumina-based powder by a known means using a ball mill or the like and pulverized. This is because the grain size of the crystallized glass powder does not fall below the desired value of 75 μm. The reason why the desired value of 75 μm or less is set here is that the crystallized glass portion exceeding 75 μm is often defective, and the mechanical strength of the finally obtained ceramic composite crystallized glass cannot be increased. .

As described above, after crushing the crystallized glass, the case where the obtained crystallized glass powder is mixed with the zirconia-based and / or alumina-based powder has been described, but the crushing of the crystallized glass and the zirconia-based and / or alumina-based powder have been described. Mixing with and may be simultaneously performed by a known means such as a ball mill. Also in this case, the grain size of the crystallized glass obtained is preferably 75 μm or less.

In this step, the zirconia-based powder mixed with the crystallized glass is partially stabilized zirconia. Partially stabilized zirconia is usually produced by utilizing the stress-induced transformation (martensite transformation) of tetragonal zirconia crystal particles in which one or more of Y ₂ O ₃ , MgO, CaO and CeO ₂ are solid-solved. It is designed to have high strength and high toughness, and exhibits high strength as high as 10,000 to 20000 kg / cm ² . Furthermore, when α-alumina is compounded with partially stabilized zirconia and densely sintered, the effect of microcrack toughening is also added, and a strength of 1500 to 24000 kg / cm ² is exhibited. The partially stabilized zirconia powder in which α-alumina is compounded is also included in the zirconia-based powder used in the present invention. To partially stabilize zirconia, Zr
Y ₂ O ₃ : 1.5 to 5 MgO: 7 to 10 CaO: 7 to 10 CeO ₂ : 4 to 15 in terms of the number of moles relative to 100 moles of O ₂ Good. When α-alumina is compounded with partially stabilized zirconia, the weight ratio of partially stabilized zirconia: α-alumina is 100: 10 to 10:90. This is because if the content of partially stabilized zirconia is less than 10%, the effect of strengthening the stress-induced transformation of zirconia is thin and it is not effective in improving strength. A more particularly preferred range is 100: 0 to 20:80.

The zirconia-based powder mixed with the crystallized glass preferably has a finer particle size than the crystallized glass powder. This is because when the particle size of the zirconia-based powder is larger than the particle size of the crystallized glass powder, in the vicinity of the contact between the zirconia particles and the crystallized glass, pores are easily formed, and a mechanical strength high zirconia-ceramic composite crystallized glass is obtained. Because it is difficult. A wet method such as a coprecipitation method, a hydrolysis method, an alkoxide method, or the like can give a fine zirconia-based powder having a size of 1 μm or less. Therefore, it is desirable to use the zirconia-based powder thus obtained.

Unlike the conventional method described in JP-A-1-115360, which requires a large amount of zirconia-based powder with respect to glass, in the method of the present invention, the amount of zirconia-based powder mixed with crystal or glass. Is not particularly limited.
The reason is that even if the amount of zirconia-based powder is small, the glass does not flow and surround the zirconia-based powder, and no porosity occurs in the vicinity of the interface between the glass and the zirconia-based powder. This is because a strong zirconia-based ceramic composite crystallized glass can be obtained, and when a large amount of zirconia-based powder is obtained, a high-strength zirconia-based ceramic composite crystallized glass can be obtained.

However, as the obtained inorganic biomaterial, when the crystallized glass is less than 5% by volume, the effect of adding bioactive function by compounding hardly appears, and 95%.
If the amount is larger, the zirconia-based ceramics portion that serves as the skeleton is reduced, so that improvement in mechanical strength cannot be expected. Therefore, the compounding ratio of crystallized glass: zirconia-based ceramics is preferably 5:95 to 95: 5 in volume percentage. Furthermore, as a material having both bioactivity and strength, a particularly preferable range is 40:60 to 90:10.

As described above, the case where zirconia-based powder is mixed with the crystallized glass has been described, but even if the alumina-based powder is used instead of the zirconia-based powder, one having a higher strength than the ceramic composite crystallized glass produced by the conventional method is obtained. can get. Alternatively, a mixture of zirconia-based powder and alumina-based powder may be used.

Next, in step 4, after the mixed powder obtained in step 3 is molded into a predetermined shape, it is heat-treated in the sintering temperature range of zirconia-based and / or alumina-based powder to be an inorganic biomaterial composed of ceramic composite crystallized glass. Is a step of obtaining.

In this step, the mixed powder of the crystallized glass powder and the zirconia-based and / or alumina-based powder may be any known means such as mold molding, cold isostatic pressing (rubber press), injection molding, and extrusion molding. After being molded in (1), it is sintered in the sintering temperature range of zirconia-based and / or alumina-based powder. When the zirconia-based and / or alumina-based powder is sintered, the glass does not flow or sinter, so that a dense and high-strength ceramic composite crystallized glass can be obtained. Zirconia and /
Alternatively, the sintering temperature range of the alumina-based powder can be determined by heating the molded body of the crystallized glass-zirconia-based and / or alumina-based powder mixture at a constant rate and measuring the heat shrinkage during that time. The sintering temperature range is from the start temperature to the end temperature of heat shrinkage. For example, the sintering of zirconia is about 80
The temperature at which densification is best starting from 0 ° C is generally above 1300 ° C. However, if the sintering temperature exceeds 1500 ° C., the crystallized glass portion may melt to form pores or react with the zirconia-based powder to lose the bioactive function, so 1500 ° C. or less is preferable. Recently, zirconia-based ceramics have been developed that can be densely sintered at a low temperature of 1000 to 1300 ° C by slightly adding transition metal oxides such as zinc, manganese, copper, cobalt and nickel [Uchida See "Zirconia Ceramics 9", pages 1 to 12 (published date: April 10, 1987) issued by Otsuruho]. Depending on the composition, crystallized glass may start melting at 1300 ° C. In such cases, 1000 to 1300 ° C
A zirconia-based powder that can be densely sintered with is preferable. Any known means may be used as the sintering method in step 4, but if the hot pressing method or the HIP (hot isostatic pressing) method is used, the sintering is further promoted and the pores are reduced, so that the mechanical It is possible to obtain a product having a high dynamic strength.

[Examples] Hereinafter, the present invention will be further described with reference to Examples, but the present invention is not limited to these Examples.

[Example 1] Oxides, carbonates, phosphates, hydrates, fluorides, and the like were used as glass raw materials, and the glass obtained had a weight percentage of Ca
A batch of glass raw materials was blended so that O 47.8, SiO ₂ 44.0, MgO 1.5, P ₂ O ₅ 6.5, and fluorine (F ₂ conversion value) were 0.2, and this was put in a platinum crucible and melted at 1550 ° C. for 2 hours. . Then, the melt was poured into water to obtain glass (step 1), and then
After drying this glass, it was heated in an electric furnace from room temperature to 1200 ° C. at a constant temperature rising rate of 3 ° C./min, and kept at 1200 ° C. for 2 hours to crystallize the glass (step 2). Next, this crystallized glass was put into a ball mill and crushed to a particle size of 500 μm or less, and then 2.5 mol% of Y ₂ O obtained by a coprecipitation method
Partially stabilized zirconia-based powder containing ₃ (average particle size 0.3μ
m) and m) were put in a ball mill at various ratios, and the mixture was wet-mixed for several hours to reduce the grain size of the crystallized glass to 75 μm or less, and then dried (step 3). Next, put this mixture into a graphite mold and apply pressure of 300 kg / cm ² from room temperature to 1300 ° C.
Was heated at a constant temperature rising rate of 3 ° C./min and held at 1300 ° C. for 2 hours to sinter the molded body. Then, it was cooled to room temperature in the furnace to obtain various zirconia-diameter ceramic composite crystallized glasses (step 4). The relative specific gravity of the zirconia ceramic composite crystallized glass produced in this way is 97.
% Or more with few pores. Further, when these zirconia-diameter ceramic composite crystallized glasses were crushed and the precipitated crystal phase was identified by powder X-ray diffraction, apatite and wollastonite were precipitated from the glass. Further, these zirconia-based ceramics composite crystallized glasses were processed into 3 × 4 × 36 mm prisms and subjected to a three-point bending strength test in accordance with JIS R1601. The relationship between the compounding amount (volume percentage) of the zirconia powder and the three-point bending strength is shown in 1 of FIG. 2 shows the relationship between the content of zirconia-based ceramics and the three-point bending strength of the inorganic biomaterial prepared by the conventional method described in JP-A-1-115360. As is clear from the figure, the inorganic biomaterial of this example had a higher bending strength than the conventional inorganic material, and particularly had a high strength even when the amount of zirconia was small.

[Example 2] Oxides, carbonates, phosphates, hydrates, fluorides, etc. were used as glass raw materials, and CaO 47.8, SiO ₂ 44.
A batch of glass raw materials was prepared so that the amounts were 0, MgO 1.5, P ₂ O ₂ 6.5, and fluorine (F ₂ conversion value) 0.2, and this was put in a platinum crucible and melted at 1550 ° C. for 2 hours. Next, the melt was put into water to obtain glass (step 1). Next, after drying this glass, a constant heating rate of 3 ° C / m from room temperature to 1200 ° C in an electric furnace
The glass was crystallized by heating at in and holding it at 1200 ° C. for 2 hours (step 2). Next, this crystallized glass was put into a ball mill and crushed to a particle size of 500 μm or less.
A partially stabilized zirconia-based powder (average particle size 0.3 μm) obtained by a coprecipitation method, which contains mol% Y ₂ O ₃ and various ratios of α-alumina, is used in a crystallized glass by volume ratio: The partially stabilized zirconia-based powder was weighed so as to be 70:30, put in a ball mill, and wet-mixed for several hours to make the grain size of the crystallized glass 75 μm or less, and then dried (step 3). Next, this mixture was put into a graphite mold and heated from room temperature to 1350 ° C. at a constant temperature rising rate of 3 ° C./min while applying a pressure of 300 kg / cm ² , and kept at 1350 ° C. for 2 hours to obtain a molded body. After sintering, it was cooled to room temperature in a furnace to obtain various zirconia-based ceramic composite crystallized glasses having different contents of α-alumina (weight percentage) in the zirconia-based ceramics (step 4). The relative specific gravity of each zirconia-based ceramic composite crystallized glass produced in this way is 96-99%.
And there were few pores. Further, when these zirconia-based ceramics composite crystallized glasses were crushed and the precipitated crystal phase was identified by powder X-ray diffraction, apatite and wollastonite were precipitated from the glass. further,
These zirconia-based ceramics composite crystallized glasses
It was processed into a prism of × 4 × 36 mm and subjected to a three-point bending strength test in accordance with JIS R1601. The relationship between the α-alumina content (weight percentage) in zirconia-based ceramics and the three-point bending strength is shown in FIG. As is clear from the figure, the inorganic biomaterial of this example had a higher bending strength than the conventional inorganic biomaterial.

Example 3 Oxides, carbonates, phosphates, hydrates, fluorides, etc. were used as glass raw materials to prepare batches of glass raw materials, which were placed in a platinum crucible and heated at 1450 to 1550 ° C. for 2 hours. Melted for hours.
Then, the melt is put into water and has the composition shown in Table 1.
A total of 32 types of glass were obtained (step 1). Next, after drying this glass, it was heated in an electric furnace from room temperature to 1200 ° C. at a constant temperature rising rate of 3 ° C./min, and kept at 1200 ° C. for 2 hours to crystallize the glass (step 2). Next, this crystallized glass was put into a ball mill and crushed to a particle size of 500 μm or less, and the obtained glass having a particle size of 500 μm or less and 2.6 mol% Y ₂ O ₃ and 0.3 mol% obtained by a coprecipitation method. And partially stabilized zirconia-based powder (average particle size 0.6 μm) containing ZnO in a volume ratio of crystallized glass powder: partially stabilized zirconia-based powder =
Weigh it to 70:30, put it in a ball mill and wet mix for several hours to reduce the grain size of the crystallized glass to 75 μm or less.
Dried (step 3). Next, 50 mm of this mixture with a mold
It was shaped into a disk of φ, heated in an electric furnace from room temperature to 1200 ° C at a constant heating rate of 3 ° C / min, kept at 1200 ° C for 2 hours, then cooled to room temperature in the furnace and pre-baked. . Next, this pre-fired body was heated at a constant temperature rising rate of 3 ° C./min from room temperature to 1200 ° C. while applying a pressure of 2000 kg / cm ² with argon gas, and kept at 1200 ° C. for 2 hours to obtain a hot work. Isotropic pressure molding (HI
P) did. Then, it was cooled to room temperature in the furnace to obtain a zirconia-based ceramic composite crystallized glass (step 4).
The zirconia-based ceramics composite crystallized glass thus produced had a relative specific gravity of 98.5% or more and a small number of pores. Further, as a result of crushing these zirconia-based ceramics composite crystallized glasses and identifying the precipitated crystal phase by powder X-ray diffraction, crystals as shown in Table 1 were precipitated. Further, these zirconia-based ceramics composite crystallized glasses were processed into 3 × 4 × 36 mm prisms and subjected to a three-point bending strength test in accordance with JIS R1601.

Table 1 shows the glass composition, the crystal phase precipitated from the glass, and the three-point bending strength. As is clear from Table-1, in this example,
The 32 kinds of inorganic biomaterials have high bending strength as compared with conventional inorganic biomaterials, even though the amount of zirconia is small.

[Example 4] Oxides, carbonates, phosphates, hydrates, fluorides, etc. were used as glass raw materials, and CaO 47.8, SiO ₂ 44.
A batch of glass raw materials was prepared so that the amounts were 0, MgO 1.5, P ₂ O ₅ 6.5, and fluorine (F ₂ conversion value) 0.2, and this was put in a platinum crucible and melted at 1550 ° C. for 2 hours. Next, the melt was put into water to obtain glass (step 1). Next, after drying this glass, a constant heating rate of 3 ° C / m from room temperature to 1200 ° C in an electric furnace
The glass was crystallized by heating at in and holding it at 1200 ° C. for 2 hours (step 2). Next, this crystallized glass was put into a ball mill and crushed to a particle size of 500 μm or less.
-Alumina powder (average particle size 0.2 μm) in volume ratio,
Crystallized glass: α-alumina powder was weighed so as to be 60:40, put in a ball mill, wet-mixed for several hours to make the crystallized glass have a particle size of 75 μm or less, and then dried (step 3). Next, this mixture was put into a graphite mold and heated from room temperature to 1350 ° C. at a constant temperature rising rate of 3 ° C./min while applying a pressure of 300 kg / cm ² , and kept at 1350 ° C. for 2 hours to obtain a molded body. Sintering was performed. Then, it was cooled to room temperature in the furnace to obtain an alumina-based ceramic composite crystallized glass (step 4). The relative specific gravity of the alumina-based ceramics composite crystallized glass thus produced was 96%. Further, when the alumina-based ceramics composite crystallized glass was crushed and the precipitated crystal phase was identified by powder X-ray diffraction, apatite and wollastonite were precipitated from the glass. Furthermore, 3 x 4 of alumina-based ceramic composite crystallized glass
The three-point bending strength measured according to JIS R1601 was 3700 kg / cm ² after processing into a × 36 mm prism.

[Effect of the Invention] According to the method for producing an inorganic biomaterial of the present invention, the bioactive function of the crystallized glass containing P ₂ O ₅ and CaO to directly chemically bond with bone and the zirconia-based and / or alumina-based ceramics It is possible to achieve both high strength of both artificial bone and extremely high strength compared to conventional inorganic biomaterials.
It is extremely useful for producing biomaterials for artificial tooth roots.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the zirconia-based ceramics content (volume percentage) and the bending strength in the zirconia-based ceramics composite crystallized glass, and FIG. 2 is the α in the zirconia-based ceramics that constitutes the zirconia-based ceramics crystallized glass.
FIG. 3 is a relationship diagram between the alumina content (percentage by weight) and the bending strength.

Claims (1)

[Claims] 1. A method for producing an inorganic biomaterial, which comprises the following series of four steps. Step 1. By melting and cooling the glass raw material mixture,
By weight percentage, CaO 12 to 56% P ₂ O _{5 1 to} 27% SiO ₂ 22 to 50% MgO 0 to 34% A 1 ₂ O ₃ 0 to 25%, containing the above components, CaO, P ₂ O ₅ , SiO ₂ , MgO and A1 ₂
A step of obtaining glass having a composition in which the total content of O ₃ is 90% or more. Step 2. The temperature range in which the glass obtained in Step 1 is precipitated with apatite and one or more kinds of alkaline earth silicate crystals selected from wollastonite, diopside, forsterite, akermanite and anorthite. Process to obtain crystallized glass by heat treatment in. Step 3. A step of obtaining the mixed powder by simultaneously or after crushing the crystallized glass obtained in Step 2, and mixing with the zirconia-based and / or alumina-based powder. Step 4. A step of molding the mixed powder obtained in step 3 into a predetermined shape and then heat-treating it in the sintering temperature range of zirconia-based and / or alumina-based powder to obtain an inorganic biomaterial composed of ceramic composite crystallized glass .