JPS6141876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a carbon fiber-apatite fired composite. In particular, the present invention relates to a fired composite containing an effective amount of carbon fiber material and a matrix amount of apatite (preferably hydroxyapatite) and a method for producing the same.

The fired composite according to the present invention has as essential raw materials:
It essentially consists of carbon fiber material as a reinforcing material and sintered apatite fired at low temperature as a matrix material. Regarding the raw materials, various kinds of carbon fibers have been developed as industrial raw materials and are commercially available. Conventionally, the use of carbon fiber as a reinforcing material for composite materials has been mainly directed to poly(condensation) cured composites with special organic synthetic resin materials. Typical apatite raw materials include hydroxyapatite, carbonate apatite, fluoroapatite, and chlorapatite. High temperature calcination methods for these apatites and especially hydroxyapatites have been proposed. However, conventional high-temperature single sintered bodies generally have problems with various strengths (especially impact and bending) and large pores due to the crystal structure of the sintered body. For example, as a method for sintering hydroxyapatite alone, there are known methods in which hydroxyapatite produced by a wet or dry method is sintered at approximately 1200°C ± 100°C without pressure or under pressure. . However, it seems that there has been essentially no success in using hydroxyapatite as a matrix material by firing it at a relatively low temperature as in the present invention. Furthermore, a non-sintered composite material has been proposed in which apatite, which has been individually fired, is dispersed and hardened in an organic resin matrix as an aggregate (for example, JP-A-55-50349).

Conventionally, glass fibers, steel fibers, and the like have been widely used as excellent reinforcing materials mainly in the field of synthetic resin composite materials. However, the heat resistance of these materials is generally less than about 800°C, which is outside the scope of conventional high-temperature sintering techniques for oxidized apatite. Incidentally, the carbon fiber material used in the present invention generally has a heat resistance of about 500°C in an oxygen-containing atmosphere or in the coexistence of high-temperature oxidizing substances such as apatite.
Since it was only a matter of degree, it was completely out of scope.

As mentioned above, conventional singly fired apatite has problems in strength, toughness, homogeneous porosity, etc., so the present inventor conducted research and development on a low-temperature fired composite using this as a matrix material. That is, a sintered composite is produced by using a reinforcing fiber material that has traditionally had excellent performance for synthetic resin composites, and sintering apatite under specific sintering conditions within the heat-resistant temperature range of the reinforcing material. oriented towards doing. According to the conventional technical knowledge of single apatite sintered bodies,
It was thought that lowering the firing temperature would make sintering difficult, or even if it were possible, the strength etc. of the sintered body would inevitably decrease. In this regard, the present inventor has proposed that by calcining apatite at a low temperature under pressure in the presence of water vapor derived from crystallization water of the apatite and preferably also water vapor derived from adhering water,
We have discovered the possibility of producing an apatite sintered body as a matrix material with sufficient strength.

Initially, we considered fired composite materials using glass fibers, which are excellent reinforcing materials and are relatively easy to obtain, and base metal fibers, which are relatively inexpensive.
At a firing temperature of approximately 700°C, expected physical properties are not observed (note that base metal fibers also have problems with corrosion and metal outflow during use). Naturally, it was expected that there would be no big difference even if carbon fiber material was used, but
As a precaution, they conducted research using carbon fiber as a reinforcing material and apatite as a matrix material at a firing temperature of less than 500 degrees Celsius, and, quite unexpectedly, they succeeded in developing a composite material with excellent physical properties.

The reason for this is not fully understood, but since glass fibers and base metal fibers have a physical and chemical affinity for apatite, they are denatured during firing of a composite material of the two, and both are sufficiently bonded. It is thought that this is because the two are in close contact and there is no room for slipping between them against external forces. On the contrary,
Although carbon fibers have a sufficient physical affinity for apatite, they are chemically completely or substantially inactive under the firing conditions of the composite of the present invention. Therefore, in the fired composite according to the present invention, since there is a slight margin of slippage between both components,
It is believed that a composite material having particularly excellent strength against impact and bending can be unexpectedly obtained. This is surprising considering the fact that in conventional resin composites of fiber materials and synthetic resins, emphasis is placed on the adhesion affinity of both components, but when the matrix is resin, the resin itself has some potential. Because it has flexibility etc.
It is thought that the problems mentioned above did not exist.

One object of the present invention is to provide a fired carbon fiber-apatite composite having various strengths and, if necessary, appropriate microporosity, and a method for producing the same. Another object of the present invention is to provide a sintered composite material that takes advantage of the excellent physical properties of the composite of the present invention and is suitable for the wide range of applications described below. Other objectives will become apparent from the description below.

Accordingly, the fired composite of the present invention is a carbon fiber-apatite based fired composite characterized in that it comprises an effective amount of carbon fiber material and a matrix amount of fired apatite fired in close contact with the material. ). The carbon fiber material in the fired composite is further characterized in that it is present in a substantially unmodified state.

By effective amount of carbon fiber material is meant an amount of the material that is effective to reinforce the fired composite and that can be bound together as a composite by the matrix of fired apatite. By matrix amount of apatite is meant an amount of apatite that can be combined with the carbon fiber material to form a composite. The relationship between the effective amount of the carbon fiber material and the apatite versus the amount of the matrix depends on the density of the carbon fiber, but in general, it is approximately
0.5-70% vs. 99.5-30%, usually 1-50% vs. 99-
50%, preferably 2-40% vs. 98-60%, more preferably 5-30% vs. 95-70%, and typically 7
~25% vs. about 93-75%. The fired composite of the present invention may contain small amounts of arbitrary materials (such as colorants, fillers, etc.) that are substantially inert under the conditions of firing, processing, and use, as long as their physical properties are not substantially impaired. ) can naturally be included.

The carbon fiber material essentially used as a reinforcing material in the present invention (it may also exhibit other effects depending on its use in biological applications, etc.) is composed mainly of carbon and/or graphite. fibrous materials. For example, typical materials include carbon fiber produced by the carbon arc method, pyrolyzed carbon fiber produced from hydrocarbons, and fired fibers of organic fibers (cellulose, rayon, polyacrylonitrile, etc.). From the standpoint of thermal stability during firing and use of the composite, carbon fiber materials produced by pyrolysis and materials whose surfaces are coated with pyrolytic carbon are particularly preferred. Regarding the form and dimensions of the carbon fiber material, common technical knowledge regarding conventional glass fiber-synthetic resin composite materials, etc. can be applied. for example,
The carbon fiber material can be in the form of short fibers, long fibers, fiber yarns, fiber bundles, wool-like fibers, non-woven fabrics and/or woven fabrics, and the like. In addition, in the case of short fibers, it is desirable that the fiber length is longer than that of the sintered apatite crystals.

The directionality of the carbon fiber material in the fired composite of the present invention may be oriented in one to three axial directions in the fired apatite matrix, or substantially unoriented and disordered, depending on the purpose and use. can exist in the state of Similarly, the distribution of the material may be such that the carbon fiber material is substantially uniformly dispersed within the composite matrix;
Or the carbon fiber material is dense (or sparse) in the direction of the core.
can be sparse (or dense) in the surface direction.

The apatite essentially used as a matrix material in the present invention typically includes hydroxyapatite, carbonate apatite, fluoroapatite, chlorapatite, and mixtures thereof, as well as those converted to apatite during the firing process of the composite. (herein referred to as apatite precursor material).

In a broad sense, apatite is defined by the following formula () A ₁₀ (XO ₄ ) ₆ Zm ...... (where A = Ca, Pb, Mn, Na, K, etc.; x = P,
As, V, Si, etc.; Z=OH, CO ₃ , F, Cl), the apatite used in the present invention is more limited, and its basic composition, which is its mineralogy definition, is expressed by the following formula (). Ca ₁₀ (PO ₄ ) ₆ Zm ...... [Here, Z is OH]. , CO ₃ , F, and Cl, and m is a number that substantially satisfies the valence (for example, 2 or 1). That is, in the above formula (), the Ca/P does not necessarily have to be a stoichiometric amount (5/3), but may be a non-stoichiometric amount, and usually the Ca/P ratio is about 4/3. 3～
It may be in the range of about 11/6 and preferably in the range of about 9/6 to about 5/3. as needed,
A non-phosphorous inorganic calcium compound is uniformly mixed into apatite with a Ca/P ratio of less than 5/3, and the Ca/P ratio is less than 5/3.
The P ratio can be brought close to the basic composition of 5/3.

In addition, Ca of apatite expressed by the formula ()
and P may be substituted with impurity amounts or small amounts of other atoms (eg, as shown in the definition of formula ()). In the present specification, Z in the above formula () may be one or more of OH, CO ₃ , F and Cl, and in this case, according to the one with the largest substitution amount, Z is hydroxyapatite, carbonate, etc., respectively. They are called apatite, fluoroapatite and chloroapatite. Both of these apatites belong to the same hexagonal crystal system, space group C6 ₃ /m and chemical formula number in the unit cell, and have substantially the same sinterability and similar physical properties. Note that these apatites can be chemically synthesized or obtained as a product (purified if necessary) by those skilled in the art.

From the viewpoint of applications, etc., the apatite used in the present invention is a hydroxyapatite in which Z is essentially an OH group in the above formula () and/or a majority of Z is an OH group, and the remaining amount ( preferably 10
Hydroxylic apatites in which a small amount (less than %) are _CO3 groups are generally and particularly preferred for biomedical applications.

The carbon fiber-apatite-based fired composite of the present invention can be produced by mixing an effective amount of the above-mentioned carbon fiber material and a matrix amount of the above-mentioned apatite, and adding an appropriate amount of moisture as necessary so that both of them are substantially by firing under pressure to substantially sinter the apatite at a temperature substantially below the denaturation temperature of the carbon fiber material and substantially preventing the loss of moisture. Can be manufactured. Note that the mixture of both components can also be preformed into a desired shape by compression or the like before firing. The above moisture content means that adhering moisture other than crystal water that coexists with apatite during firing is substantially 0 to about 20% by weight based on the amount of apatite.
The amount is preferably about 0.01 to about 15% by weight. As the water content increases, the amount of voids in the fired product increases, but sintering also tends to be accelerated. about
If it exceeds 20%, the amount of voids will generally become excessive. However, in the case of open heating such as the hot press method, the amount of water in the preparation may be larger.

Although the sintering mechanism of apatite has not been fully elucidated, it seems to be due to the fact that apatite is melted and precipitated depending on the firing temperature, and then becomes entangled and sintered. At this time, the higher the pressure, the more the above-mentioned dissolution precipitation tends to be promoted. In addition, the presence of moisture in a sealed state tends to promote the dissolution precipitation. From this point of view, by employing high pressure and the presence of an appropriate amount of moisture in the firing process, the firing temperature can be significantly lowered.
Separately from this, in the present invention, at least some degree of pressure is preferably applied before and/or during firing in order to bring both components into close contact with each other.

In the firing step in the present invention, techniques known in the firing or sintering industry can be employed. For example, a hot press method, a sealed pressure firing method such as an autoclave method, a high frequency heating method under pressure, an isotactic compression heating method, etc. can be advantageously used. Applications of typical firing methods are outlined below.

(b) In the case of the hot press method, a mixture of the above-mentioned materials or a preform thereof is heated in a pressurized atmosphere of water vapor or an inert gas containing water vapor from about 150°C to below the denaturation temperature of the carbon fiber material. (depending on the nature of the fiber, e.g. less than about 800°C) and preferably from about 150°C to about
About 10Kg/cm2 ^or more at a temperature of about 500℃, for example about 10
Fire for 0.5 hours or more under pressure of ~1000 atm. When firing the preform, it is already compressed, so there is no need to apply particularly high pressure (for example,
Can be fired at Kg/cm ² or higher). Note that compression by the hot press method is, in principle, in the axial direction.

(b) When using a sealed pressurized firing method such as an autoclape method, firing is performed for 0.5 hours or more under a pressure of several tens to several thousand atmospheres at a temperature below the denaturation temperature of carbon fiber using, for example, an ultra-pressure resistant container. . On this occasion,
If the temperature and pressure are low, it will take a long time to fire, but if the pressure is set to 1000 atmospheres or more, it will take about 150
Firing is advantageously achieved even at temperatures on the order of °C. Therefore, the firing conditions should be approximately 10 kg/cm ² or more, preferably approximately 20 kg/cm 2 or more.
Kg/cm ² or more, for example, about 20 to about 2000 atm (up to about 3000 atm if pressure resistance allows), about 150℃ to about
0.5 at 800℃ (preferably about 150℃ to about 500℃)
It can be summarized as more than an hour. Note that the pressurization in this mode is substantially non-axial pressurization.

(c) In the above-mentioned sealed pressure firing method, the above-mentioned pressure high-frequency heating method, isobaric compression heating method, etc., a mixture or preform of composite raw materials is sealed in a substantially inert pressure-deformable container. The present invention can be achieved even more effectively when firing. The firing conditions in this case are the same as those in (b) above, but preferably about 40 to about 3000 kg/cm ² and about 150° to less than about 500° C. for about 0.5 hours or more. Adoption of such a sealed container has the advantage that raw material components, moisture, gas, etc. are retained unchanged.
Note that the compression pressurization in this embodiment is substantially equal pressure compression.

The carbon fiber-apatite-based sintered composite according to the present invention has a carbon fiber material, which is essentially a reinforcing material, present in an unmodified state in close contact with a sintered matrix in which apatite crystals are intertwined. Depending on the sintered apatite, the sintered apatite is a sintered composite with appropriate microporosity. Due to the firing conditions of the present invention, the sintered apatite crystal has a fine structure in which fine linear and/or curved needle crystals are intertwined, and its strength is increased. That is, the lower the firing temperature is (below 800°C), the more fine crystals, especially fine needle-like crystals, tend to be produced and the strength increases. 〔In addition,
If the firing temperature is high as in the conventional technology (for example, 1100
℃), the structure becomes a structure consisting of relatively large hexagonal crystal groups, and the strength decreases. ] Furthermore, when the amount of voids becomes excessive, the strength naturally decreases. Therefore, in order to obtain the composite having excellent strength and sufficient microporous voids, the above firing conditions should be relatively high pressure and low temperature, preferably within the above range. It is preferable to carry out the firing in the coexistence of moisture.

The physical properties of the fired composite according to the present invention may vary depending on the composition of the composite raw material, firing conditions, etc., but exemplarily have numerical values within the following range.

(i) Average width of sintered apatite crystals 0.01 to 5 μm
○｜ (ii) Average length of sintered apatite crystals 1 to 1000 μm (iii) Average pore radius of sintered apatite 5 to 1000 μm
m (iv) Porosity of sintered apatite crystal 0-40% by volume (v) Compressive strength of fired composite 500-800Kg/cm ² (vi) Bending strength of fired composite 1200-2400Kg/cm ² (vii) Firing Impact strength of the composite: 50-120 Kg/cm/cm ² (viii) Tensile strength of the fired composite: 70-100 Kg/cm ² The fired composite according to the present invention can be used in a wide range of applications depending on its unique excellent physical properties. , and can be particularly advantageously applied to fields where various strengths are required. Typical examples include ceramic materials that require strength, electrical and electronic equipment materials, filter media, carriers for chromatography, sensor (especially for biological use) elements, ceramics for biological use (artificial bones, artificial teeth, artificial joints), etc. Other applications to which conventional fine ceramics are applied are exemplified. The above-mentioned various uses can be broadly classified into industrial ceramic materials and bio-use ceramics, but bio-use ceramics require strength and microporosity as well as compatibility with living organisms. Therefore, biocompatibility will be discussed below.

Hard tissues (bones, teeth, etc.) in mammals and especially humans are composed of hydroxyapatite, which essentially contains only hydroxyl groups (specifically apatite, which contains a small amount of carbonate groups).
It is known that the main component is Therefore,
A considerable number of studies have been reported on the use of sintered hydroxyapatite alone for artificial bones and teeth. In particular, it is recognized in the industry that porous single sintered bodies are reasonably satisfactory in terms of compatibility with living organisms. However, as mentioned above, hydroxyapatite single sintered bodies mainly have problems in impact strength and bending strength, so it seems difficult to put them into practical use immediately at present. On the other hand, it is recognized in the industry that carbon fiber material, which is another raw material in the present invention, has advantages such as excellent strength, elastic modulus, and chemical non-irritation, and also has satisfactory biocompatibility. has been done. However, in the case of these carbon fiber materials alone or a mixture of these materials and carbon, there are problems such as detachment of fine carbon materials, non-porosity, and X-ray transparency.

Both components used in the present invention have satisfactory biocompatibility, and the required strength and porosity of approximately 5% to 40% are sufficiently ensured by the present invention. Therefore, the carbon fiber-hydroxyapatite fired composite according to the present invention can solve the above-mentioned problems and provide a material for hard tissue having satisfactory biocompatibility. Furthermore, since the fired composite of the present invention also has lubricity due to the carbon fiber material, it can be used for artificial joints to which conventional sintered apatite is difficult to apply.

Incidentally, it should be noted that in the fired composite according to the present invention, the patented single sintered body and its manufacturing method are included in the single apatite sintered body that is fired after removing the carbon fiber material. In addition,
Firing temperatures in this case can be up to about 1000°C or higher.

The present invention will be further explained below by giving typical examples. However, since all the apatites used in the present invention have substantially the same chemical structure, crystal system, sinterability, etc. It is not limited to these examples. That is, those skilled in the art can easily manufacture similar fired composites according to the disclosure of the present invention, if necessary, using apatite raw materials other than the apatite used in the examples below.

In addition, in the following examples, all percentages are by weight.

Example 1 (comparative example) 85% powder of hydroxyapatite (Ca/P ratio 95/60), which essentially contains only hydroxyl groups, and 15% pyrolytic carbon fiber (average length 9 mm) are homogeneously mixed, and approximately 5×10
Preform into a cylinder of mm (diameter). Then, it is pre-dried to a moisture content of 5%. This sample is compressed and fired in a hot press at 1100° C. and 200 kg/cm ² for 2 hours. The physical properties of the fired composite after being allowed to cool are shown below.

Compressive strength 310Kg/cm ^2Bending strength 320Kg/cm ^2Tensile strength 40Kg/cm ^2Sharpey impact strength 8 Kg・cm/cm ^2When observing the fracture surface of the sample in the bending test, the fibers were cut on the fracture surface. has been done.

Example 2 (Comparative Example) A single sintered body is produced in the same manner as in Example 1 above, using only apatite powder without using the carbon fiber material. The physical properties of the sintered body after cooling are shown below (units are the same as above).

Compressive strength 320 Bending strength 310 Tensile strength 35 Charpy impact strength 7 The crystals of the apatite sintered body obtained by the conventional method are shown in Figure 2 (magnification x 7500). It is noted that the crystal has a coarse hexagonal structure.

Example 3 (Comparative Example) In Example 1 above, 15% glass fiber (average length 9 mm) was used instead of carbon fiber, and preforming and
Dry and bake under the same conditions.

The physical properties of the composite after cooling are shown below (units are the same as above).

Compressive strength: 305 Bending strength: 310 Tensile strength: 45 Charpy impact strength: 8 At the fracture surface in the bending test, the fibers were similarly cut on that surface.

In Examples 1 and 3 (comparative example) above, the fact that the fibers are cut at the fracture surface in terms of bending strength indicates that the fibers have deteriorated. Furthermore, it should be noted that the hot press sintering process in Examples 1-3 (comparative examples) was carried out without the application of pressurized steam. Since substantially all of the water present in the apatite in the steps of Examples 1 to 3 is rapidly removed from the mold of the hot press, this firing step corresponds to the firing of apatite in the absence of water. be.

Example 4 The homogeneous mixture in Example 1 above is predried to a moisture content of 5% without preforming. This is sealed in a pressure-deformable silver tube and placed in a pressure-resistant heating container at 300°C.
Then, it is fired for 5 hours under the condition of 1000Kg/cm ² . The physical properties of the fired composite after being allowed to cool are shown below.

Compressive strength (Kg/cm ² ) 580 Bending strength (Kg/cm ² ) 1285 Tensile strength (Kg/cm ² ) 100 Shalpy impact strength (Kg・cm/cm ² ) 95 The fracture surface in the bending test shows that carbon fiber is pulled out slightly from the fractured surface and cut.

Example 5 (Example) Calcium carbonate powder is mixed with hydroxyapatite powder (Ca/P ratio = 95/60) containing essentially only hydroxyl groups to make the Ca/P ratio approximately 5/3. 85% of this mixed powder and pyrolytic carbon fiber (average length 9
mm) 15% and dry to 5% moisture. This was sealed in the same manner as in Example 4 and fired under pressure under the same conditions. The physical properties of the fired composite after cooling are shown below (units are the same as above). Note that it is particularly preferable that this complex contains a carbonate group from the viewpoint of biocompatibility.

Compressive strength 560 Bending strength 1270 Tensile strength 95 Example 6 (Reference example) Hydroxyapatite (Ca/P ratio = 95/60), which essentially contains only hydroxyl groups, is adjusted to a moisture content of 5%. This hydroxyapatite powder was sealed in a pressure-deformable silver tube and heated to 500°C using a pressure-resistant heating container.
Baked for 3 hours under a pressure of 1000Kg/cm ² . The physical properties of the obtained apatite sintered body are shown below.

Compressive strength 520Kg/cm ² Bending strength 710Kg/cm ² Tensile strength 55Kg/cm ² Impact strength (shear ruby) 16Kg・cm/cm ² Porosity (open micropores) Approx. 24% by volume The crystals of this apatite sintered body Diagram (magnification
30000). Therefore, it is recognized that the crystals of sintered apatite, which is the matrix material in the present invention, are composed of fine needle-like crystals and have a fine structure in which the crystals are intertwined with each other.

[Brief explanation of the drawing]

FIG. 1 is a scanning electron micrograph (magnification: x30,000) of a sintered hydroxyapatite body according to the present invention, showing the fine, intertwined acicular crystal structure of the sintered body. FIG. 2 is a scanning electron micrograph (magnification x 7500) of an apatite sintered body produced by a conventional high-temperature sintering method, showing the coarse hexagonal crystal structure of the conventional apatite sintered body.

Claims (1)

[Scope of Claims] 1. An effective amount of reinforcing carbon fiber material, and a material fired in close contact with the fiber material under pressure at a low temperature of 800°C or less under conditions that substantially prevent moisture loss. , a matrix amount of sintered apatite selected from hydroxyapatite, carbonate apatite, fluoroapatite, chlorapatite, and mixtures thereof, and the sintered apatite is a matrix material with a fine crystal structure having sufficient strength. 1. A fired carbon fiber-apatite composite, characterized in that the carbon fiber material is substantially unmodified. 2. The composite of claim 1, wherein the carbon fiber material ranges from 1 to 50% by weight and the apatite ranges from 99 to 50% by weight. 3 The basic composition of the apatite is expressed by the following formula, and the atomic ratio of calcium to phosphorus (Ca/P
Claim 1, wherein the ratio) is apatite in the range of 4/3 to 11/6 or a mixture thereof.
or a binary complex, Ca ₁₀ (PO ₄ ) ₆ Zm, where Z is selected from one or more of OH, CO ₁ , F, and Cl, and m is a number satisfying the valence. 4. The composite according to any one of claims 1 to 3, wherein the carbon fiber material is in the form of short fibers, long fibers, fiber yarns, fiber bundles, wool-like fibers, nonwoven fabrics, and/or woven fabrics. 5. Claims 1 to 5, wherein the carbon fiber material is a pyrolytic carbon fiber material and/or a material whose surface is coated with pyrolytic carbon.
A complex of any of the four terms. 6. The composite according to any one of claims 1 to 5, wherein the carbon fiber material is substantially oriented in one to three axes. 7. A composite according to any one of claims 1 to 6, wherein the carbon fiber material is substantially uniformly dispersed in a matrix. 8 The sintered apatite which is the matrix material is 40
The composite according to any one of claims 1 to 7, having micropores with a porosity of less than or equal to % by volume. 9. The composite according to any one of claims 1 to 8, wherein the apatite is hydroxyapatite and/or hydroxyapatite substituted with a small amount of CO ₃ group. 10. The composite according to claim 9, which is a biomedical ceramic. 11 consisting essentially of a matrix amount of an apatite raw material selected from the group consisting of hydroxyapatite, carbonate apatite, fluoroapatite, chlorapatite, mixtures thereof, and apatite precursor materials thereof and a reinforcing effective amount of carbon fiber material; sintering the composite material in substantially close contact at a temperature below 800° C. and below the denaturation temperature of the carbon fiber material under pressure in the presence of moisture at least equivalent to the water of crystallization of the apatite; The sintered apatite matrix material is characterized in that the apatite is sintered, and the sintered apatite matrix material has a fine crystal structure with sufficient strength, and the carbon fiber material is substantially unmodified. Method of manufacturing the complex. 12 The firing process is carried out at 10Kg/cm ² in a temperature range from 150°C to below the denaturation temperature of the carbon fiber material under the firing conditions.
Claim 1 carried out under the above pressure.
Method for producing the complex of Section 1. 13. The method for producing a composite according to claim 11 or 12, wherein the calcination is carried out in the presence of water in addition to crystallization water of apatite. 14. The method for producing a composite according to any one of claims 11 to 13, wherein the mixed material is sealed in a pressurized deformable container and fired. 15. A method for making a composite according to any of claims 11 to 14, wherein the carbon fiber material is in the range 1 to 50% by weight and the apatite is in the range 99 to 50% by weight. 16 The basic composition of the apatite is expressed by the following formula, and the atomic ratio of calcium to phosphorus (Ca/P
Claims 11 to 12, wherein the ratio) is apatite or a mixture thereof in the range of 4/3 to 11/6.
15. Method for producing any of the 15 complexes. Ca ₁₀ (PO ₄ ) ₆ Zm Here, Z is selected from one or more of OH, CO ₃ , F, and Cl, and m is a number satisfying the valence. 17 Claims 11 to 1, wherein the carbon fiber material is in the form of short fibers, long fibers, fiber yarns, fiber bundles, wool-like fibers, nonwoven fabrics, and/or woven fabrics.
A method for producing any of the complexes of Section 6. 18 Claim 1, wherein the carbon fiber material is a pyrolytic carbon fiber material and/or a material whose surface is coated with pyrolytic carbon.
A method for producing a composite according to any one of items 1 to 17. 19. The method for producing a composite according to any one of claims 11 to 18, wherein the apatite is hydroxyapatite and/or hydroxyapatite substituted with a small amount of _CO3 group. 20. The method for producing a composite according to claim 19, wherein the composite is a bioceramic.