JP2005097052A - Hydroxyapatite with large surface area and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide hydroxyapatite having a ultrathin chip-like form of nano-structure which is new in terms of the shape, size and surface area, and to provide its manufacturing method. <P>SOLUTION: A hydroxyapatite/surfactant composite material is composed of an apatite crystal portion containing calcium phosphate as a main component, and a nonionic surfactant, and has the form of chain-shaped ultrathin chips having width of 5-9 nm and length of ≥50 nm, or strip-shaped ultrathin chips having width of 2-5 nm and length of 10-100 nm. The hydroxyapatite with a large surface area is obtained by firing the above composite material at a temperature for applying pyrolysis of the surfactant. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to medical scaffold materials such as teeth and artificial joints utilizing biocompatibility, chemical and electrical properties of calcium phosphate, biological component adsorbents such as proteins, ion exchangers, catalyst carriers, humidity sensors, and basic cosmetics. Apatite crystals with a novel size and form, mainly composed of calcium phosphate, having a size shown at the nano level of several nanometers to several tens of nanometers, and exhibiting a chain shape, strip shape or plate shape The present invention relates to a high surface area compound having a structure and a method for producing the same.

Brushite CaHPO ₄ · 2H ₂ O (monoclinic crystal) produced in the acidic region as a crystalline compound of calcium phosphate, octacalcium phosphate Ca ₈ (HPO ₄ ) ₂ (PO ₄ ) ₄ · xH ₂ produced in the neutral region There are three types: O (triclinic) and hydroxyapatite Ca ₅ (PO ₄ ) ₃ OH (hexagonal) formed in the basic region. Of these, apatite, which is important as a component of bones and teeth, has excellent biocompatibility, chemical and electrical properties due to its composition and structure, and it has traditionally adsorbed biocomponents such as bone grafting materials and proteins. Used as agents, ion exchangers, catalyst carriers, humidity sensors, basic cosmetics, and the like. These properties of apatite often depend significantly on the crystal structure, morphology and surface area. For this reason, various methods for synthesizing apatite including morphology control have been developed (see Non-Patent Document 1).

The synthesis method of hydroxyapatite is a solid phase reaction method in which calcium triphosphate, calcium carbonate and water are reacted at 1000 ° C. or higher, a conversion reaction method in which element substitution of chlorapatite is performed at 1000 ° C. or higher, and hydrothermal conditions at 300 to 700 ° C. Hydrothermal reaction method for growing crystals under the water, Reflux method in which brushite is boiled and heated in water, Hydrolysis method in which brushite and calcium triphosphate are hydrolyzed at 100 ° C or less to convert them to apatite, Calcium salt aqueous solution and phosphoric acid It is roughly classified into a precipitation reaction method in which an aqueous salt solution is mixed and reacted under basic conditions of pH 8 to 10 (see Non-Patent Document 1). Among these, in the former four cases using the reaction at high temperature, the produced hydroxyapatite is highly crystalline and the crystal size is micrometer or more. For example, in the case of the solid phase reaction method, the surface area is small (2 m ² / g or less). ) Obtained as massive particles. Fine particles are generated in two's method after contrast, the surface area, 10 to 60 m ² / g approximately hydrolysis method, those of about 100 m ² / g is obtained at larger than the precipitation reaction method .

The form of the hydroxyapatite particles varies depending on the synthesis conditions. In the usual precipitation reaction method, irregularly shaped particles are produced, but it is possible to control the form of columns, spheres, fibers, etc. based on the above synthesis method. In the reaction based on the hydrothermal reaction method, fine particles having a columnar shape, a needle shape, and a whisker shape are obtained. Spherical particles are obtained in the spray pyrolysis method in which a mixed solution of an aqueous calcium salt solution and an aqueous phosphate solution is sprayed onto a high temperature part. This spherical powder is used as an easily sinterable powder or an adsorption filler for chromatography. In the calcium chelate complex method in which hydrogen peroxide is added to an EDTA-Ca salt- (NH ₄ ) ₂ HPO ₄ -KOH aqueous solution, the aggregated secondary particles in the form of rods, squirrels, or boiled agglomerated plate-like fine primary particles available. Prepare a viscous liquid by mixing 1000 nm or less of apatite fine particles of 1000 nm or less produced by precipitation with water, and optionally dispersing agent, plasticizer and softening agent. By performing (spinning method), fibrous particles can be prepared. When an aqueous phosphate solution is added onto an agar gel impregnated with calcium ions and allowed to stand, Ca / P = 1.3 to 1.4 from the gel surface toward the aqueous phosphate solution, and the hollow ellipsoid is zigzag. It has been reported that the woven apatite connected to the crystal grows from several centimeters to several tens of centimeters (see Non-Patent Document 2). In general, the hydrothermal reaction method tends to be a hexagonal column. However, when a low crystalline apatite is hydrothermally treated at a pH of 150 to 200 ° C. in the presence of almost the same amount of methanol, a plate-like particle of 50 to 200 nm is formed. (See Non-Patent Document 3).

Hideaki Kadoma, Inorganic materials, 2, 401-405 (1995) K. Kamiya, T .; Yoko, K .; Tanaka, Y. et al. Fujiyama, J. et al. Mater. Sci. , 24, 827 (1989) Nagata, Nikka Kaoru 6 Fall Annual Meeting Proceedings, 201 (1993) 4B418

On the other hand, a relatively versatile method for producing a high surface area inorganic material was developed by Mobil in 1992 (see Non-Patent Document 4). That is, a meso-fine structure such as a 2-8 nm honeycomb shape or a three-dimensional mesh shape is obtained by a template synthesis method in which an inorganic-organic composite obtained by reacting a surfactant with an irregular component is baked to remove the organic component. Mesoporous silica with a high surface area of up to 1000 m ² / g was created. Thereafter, in the same manner, many kinds of mesoporous materials having metal oxides such as zirconia, titania, alumina and sulfides as skeleton components in addition to silica were synthesized one after another (see Non-Patent Document 5). During this time, a group of researchers including the present inventor also produced a complex formed by homogeneous precipitation using urea using dodecyl sulfate ions as a template, and then exchanging the template ions with acetate ions, thereby forming a hexagonal rare earth. An oxide mesoporous material is obtained (see Non-Patent Document 6 and Non-Patent Document 7).

C. T. T. et al. Kresge and 4 others, Nature, 359, p. 710-712 (1992) Takeshi Kijima et al. Soc. Inorg. Mater, 8, p. 3-16 (2001) M.M. Yada and three others, Inorg. Chem, 37, 6470-75 (1998) M.M. Yada and three others, Angew. Chem. Int. Ed, 38, 3506-09 (1999)

In vivo, hydroxyapatite forms bones and teeth by complexing with collagen fibers, and plays an important role in supporting biological activities. On the other hand, hydroxyapatite is involved in organic compounds and higher tissues. It is closely related to organic substances. Therefore, there are many research reports on the production of hydroxyapatite in the presence of various organic substances (see Non-Patent Documents 8 and 9). Among them, the production of hydroxyapatite in the presence of a surfactant has also been studied. Prepared reverse phase microemulsion with water phase connected by mixing cationic surfactant didodecyldimethylammonium bromide, calcium phosphate aqueous solution and long-chain alkane tetradecane, and left this for 3 weeks at the temperature where only oil phase is frozen By doing so, it has been reported that a network structure having a pore diameter of 0.1 to 8 μm and a wall size of 100 to 250 μm, in which acicular crystals of hydroxyapatite are connected, was obtained (see Non-Patent Document 10). .
It has also been reported that when Ca ions encapsulated in liposomes and phosphate are reacted under basic conditions in the presence of the surfactant Triton X-100, fine plate-like apatite crystals found in bone tissue are produced. (See Non-Patent Document 11). However, with respect to calcium phosphate containing hydroxyapatite, there is no report example that a high surface area compound having a nanostructure such as a honeycomb or a three-dimensional network is obtained by a synthesis method using a surfactant as a template.

Tsuyoshi Kijima, gypsum and lime, No. 158, 28-35 (1979) Tatsuo Ishikawa, Surface, 5, 388-397 (1997) D. Walsh and two others, Science, 264, 1576-1578 (1994) P. B. Messengers and two others, Chem. Mater. 10, 109-116 (1998)

  In recent years, hydroxyapatite includes artificial bone materials such as bone filling materials (see Non-Patent Documents 12 and 13), biological component adsorbents such as proteins listed at the beginning, ion exchangers, catalyst carriers, humidity sensors, and basic cosmetics. In addition, application to virus adsorption masks, antibacterial agent carriers, cartridge-filled talcum material used in blood component analysis, drug carriers, etc. are also being planned, and the importance of apatite as a surface functional material has further increased. Yes. For this reason, proposals for controlling the crystal form and aggregate state of apatite or increasing the surface area have been proposed in patent applications (Patent Documents 1 to 3). However, those disclosed in these patent documents are those having 20 to 5000 μm (patent document 1), 2 to 4000 μm (patent document 2), and calcined secondary particle diameter of 15 to 300 μm (patent document 3). However, the particles themselves were not at the nano-level and nanostructure. Furthermore, recently, when a composition containing a metal element is divided into dots, lots, wires, or tubes of molecular scale or about nanometers into a microstructure called a nanostructure, a catalyst unique to a microstructure including a quantum effect is obtained. It is predicted that functions such as properties, electrochemical properties, and magnetic properties are specifically expressed (see Non-Patent Documents 14 and 15), and nanostructures are also expected for apatite.

Mori and two others, Japanese Patent Laid-Open No. 2-180706 Mori and two others, Japanese Patent Laid-Open No. 2-180709 Nakajo and two others, Japanese Patent Laid-Open No. 4-118047 Masaru Kokubo and two others, ceramics, 38, 2-10 (2003) Tetsuro Ogawa and three others, ceramics, 38, 51-54 (2003) Supervised by Tomoji Kawai, “All about Nanotechnology”, Chapter 2-4, edited by Industrial Research Committee (2001) Nikkei Science, December issue, 16-94 (2001)

The present invention has a variety of research reports on the hydroxyapatite introduced and listed in the prior art, and a new shape, a new size, a new surface area, and a new physical property different from these while keeping in mind the prior art. It is intended to provide hydroxyapatite and a method for producing the same. In particular, the shape is 5 to 20 nm in width, 50 nm or more in length, and a chain-like ultrathin-like form having a surface area of 300 m ² / g or more, or 1 to 5 nm in thickness, 2 to 5 nm in width, and 10 to 100 nm in length. In a strip-like ultrathin flaky shape having a surface area of 150 m ² / g or more, or a thin plate shape having a thickness of 5 nm or less and an outer diameter of 10 to 100 nm, excellent properties resulting from a new shape and a high surface area Hydroxyapatite nanostructures having the above-mentioned properties, and thus having the biocompatibility, electrochemical characteristics, and ion exchange characteristics unique to hydroxyapatite, and having a chemically excellent function derived from its skeleton shape and high surface area It is intended to provide hydroxyapatite that is specifically expressed. This also aims to provide new materials that contribute to technological innovation in the fields of chemistry, information, environment and biotechnology.

Among those disclosed in the prior art shown in the above prior art, In addition to the network structure of hydroxyapatite needle crystals linked by Walsh et al., Report examples related to chain-shaped ultrathin flakes, strip-shaped ultrathin flakes, or lamellar hydroxyapatite include fine plates (non-patent There are two examples of woven apatite hydroxyapatite (see Non-Patent Document 2) in which hollow ellipsoids are connected in a zigzag, and each of the low crystalline apatite is water in the presence of almost the same amount of methanol. Fibrous apatite in which hollow ellipsoids are connected to zigzags by adding a phosphate aqueous solution as plate-like particles of 50 to 200 nm by heat treatment or on an agar gel impregnated with calcium ions. As obtained. However, there is an apatite shape having a width of 5 to 20 nm, a length of 50 nm or more, and a chain-shaped ultrathin flaky shape having a surface area of 300 m ² / g or more, or a thickness of 1 to 5 nm and a width of 2 ˜5 nm, length 10 to 100 nm, and a strip-shaped ultrathin piece having a surface area of 150 m ² / g or more, or a thin plate having a thickness of 5 nm or less and an outer diameter of 10 to 100 nm is completely disclosed and mentioned. There is no. This also applies to other prior documents.

In addition, as described above, calcium phosphate containing hydroxyapatite is different from various metal oxides such as silica and zirconia, and has a honeycomb shape, a three-dimensional network shape and the like by a synthesis method using a surfactant as a template. There is no report example that a high surface area structure having a nanostructure was obtained. Thus, the main reason why a high surface area hydroxyapatite nanostructure has not been realized at present is that when hydroxyapatite, which is hardly soluble in water, is crystallized from an aqueous solution, the precipitation rate of the crystal is high, and the surfactant This is considered to be difficult to be controlled or controlled by template molecules such as. The above facts suggest that a further breakthrough of the synthesis method is necessary to realize an apatite nanostructure having a high surface of 100 m ² / g or more.

On the other hand, when two or more kinds of surfactants having different hydrophilic group structures are mixed, the surface tension and critical micelle concentration (CMC) are reduced as compared with a single system, and the synergistic effect such as improvement of emulsifiability and foaming property is achieved. Has already been well known and is used in practical materials such as detergents (see Non-Patent Document 16).
However, there has been no example of applying such a composite effect to template synthesis until recently, and in the synthesis of nanoporous materials and inorganic nanotubes using surfactant as a template, a single surfactant is used as a template component for both. I came. On the other hand, a research group including the inventor recently used a nematic liquid crystal phase obtained by mixing a nonionic surfactant and a cationic surfactant as a reaction field, and thereby has a wire with a diameter of about 1 μm. The inventors have found that silver bromide and tin oxide can be obtained, and have found that the composite surfactant system is effective for the synthesis of nanostructures (see Non-Patent Document 17). Furthermore, a nonionic surfactant having a relatively small hydrophilic part size or an ionic surfactant and a nonionic surfactant having a relatively large hydrophilic part size were added in advance to a molecular structure formed by mixing two components. It has been found that nanotube-like particles having a noble metal skeleton grow by a reaction for reducing the noble metal component (Patent Document 4). However, it was unclear whether this template method using two types of surfactants is effective for the synthesis of such nanostructures for oxides and oxyacid salts other than metals.

Manabu Senoo and one other, Chemistry and Application of Surfactants, Dai Nippon Books, Chapter 4 (1995) T. T. et al. Kijima and three others, Langmuir, 18, 6453-6457 (2002) Tsuyoshi Kijima, Japanese Patent Application No. 2002-194663

  Therefore, the inventor further examined the types of calcium and phosphate used, the types of surfactants and the reaction conditions in order to realize the creation of hydroxyapatite nanostructures by a template synthesis method based on a composite surfactant system. As a result of diligent research, two types of surfactant components, the nonionic surfactant with a relatively small hydrophilic part size or an ionic surfactant and a nonionic surfactant with a relatively large hydrophilic part size, or the latter High surface area chain ultrathin flakes, strips ultrathin flakes, or thin plates with hydroxyapatite as a skeleton by adding a base such as ammonia water to the molecular structure formed by mixing only the components with an acidic aqueous solution of calcium phosphate It was investigated that the granular particles grow.

That is, as a result of intensive studies, the present inventors have succeeded in solving and achieving the above-described problem by the invention in which the technical configuration described below is taken.
That is, the first invention is selected from the group consisting of (1) an apatite type crystal part mainly composed of calcium phosphate, a polyoxyethylene sorbitan ester such as polyoxyethylene sorbitan monostearate, and a polyoxyethylene alkyl phenyl ether. A nonionic surfactant, or a nonionic surfactant selected from the group consisting of polyoxyethylene alkyl ethers such as nonaethylene glycol monohexadecyl ether and polyoxyethylene fatty acid esters It is composed of 40 to 60% by weight of a surfactant part composed of two types of nonionic surfactants or hydrolysis products thereof, and has a chain-like ultrathin shape having a width of 5 to 9 nm and a length of 50 nm or more. Hydroxyapatite / characterized by having a morphology A surface active agent complex.

  The second invention is (2) an apatite type crystal part mainly composed of calcium phosphate, a polyoxyethylene sorbitan ester such as polyoxyethylene sorbitan monostearate, and a nonoxygen selected from the group consisting of polyoxyethylene alkyl phenyl ethers. It is composed of 40 to 60% by weight of a surfactant part made of an ionic surfactant or a hydrolysis product thereof, and has a strip-like ultrathin flaky shape with a width of 2 to 5 nm and a length of 10 to 100 nm. And a hydroxyapatite / surfactant complex.

  The hydroxyapatite / surfactant complex shown in (1) to (2) is a complex compound that becomes a precursor of hydroxyapatite described in (3) to (4) below, and is described next (3 The hydroxyapatite of (4) to (4) is derived by removing organic components from the hydroxyapatite / surfactant complex described in (1) to (2).

That is, the third invention (3) is obtained by subjecting the hydroxyapatite / surfactant complex shown in the preceding item (1) to a baking treatment at a temperature at which the surfactant component in the complex is thermally decomposed. Hydroxyapatite characterized by having a chain-like ultrathin flake form having a width of 5 to 20 nm and a length of 50 nm or more, and having a surface area of 300 m ² / g or more.

The fourth invention (4) is obtained by subjecting the hydroxyapatite / surfactant complex shown in the preceding item (2) to a baking treatment at a temperature at which the surfactant component in the complex is thermally decomposed, and A hydroxyapatite characterized by having a strip-shaped ultrathin flaky shape having a thickness of 1 to 5 nm, a width of 2 to 5 nm, and a length of 10 to 100 nm and a surface area of 150 m ² / g or more.

The fifth to eighth inventions present the methods for producing rare earth oxides of the first to fourth inventions.
That is, the fifth invention is (5) one kind of calcium salt selected from the group consisting of calcium salts such as calcium nitrate and calcium chloride, and phosphates such as sodium monohydrogen phosphate and sodium dihydrogen phosphate. Nonaethylene, a kind of nonionic surfactant selected from the group consisting of one kind of phosphate selected from the group consisting of, polyoxyethylene sorbitan esters such as polyoxyethylene sorbitan monostearate, and polyoxyethylene alkylphenyl ether A reaction mixture comprising a nonionic surfactant selected from the group consisting of polyoxyethylene alkyl ethers such as glycol monohexadecyl ether and polyoxyethylene fatty acid esters, an acid such as nitric acid, and water is prepared, and then Add a base such as ammonia to the reaction mixture. A nonionic surfactant selected from the group consisting of an apatite-type crystal part mainly composed of calcium phosphate, a polyoxyethylene sorbitan ester such as polyoxyethylene sorbitan monostearate, and a polyoxyethylene alkyl phenyl ether One or two nonionic surfactants in combination with one nonionic surfactant selected from the group consisting of polyoxyethylene alkyl ethers such as nonaethylene glycol monohexadecyl ether, polyoxyethylene fatty acid esters, or Hydroxyapatite / interface consisting of 40 to 60% by weight of a hydrolyzate product and having a chain ultrathin flake shape having a width of 5 to 9 nm and a length of 50 nm or more Generate and recover activator complex It characterized Rukoto a method for producing a hydroxyapatite / surfactant complex according to (1).

  The sixth invention is a group consisting of (6) one kind of calcium salt selected from the group consisting of calcium salts such as calcium nitrate and calcium chloride, and a phosphate such as sodium monohydrogen phosphate and sodium dihydrogen phosphate. A non-ionic surfactant selected from the group consisting of a polyoxyethylene sorbitan ester such as polyoxyethylene sorbitan monostearate, a polyoxyethylene alkylphenyl ether, an acid such as nitric acid And a reaction mixture consisting of water and then adding a base such as ammonia to the reaction mixture and reacting them, thereby making it possible to react with an apatite-type crystal part mainly composed of calcium phosphate and a polyoxyethylene sorbitan monostearate or the like. Oxyethylene sorbitan ester, polyoxyethylene ester A strip composed of a nonionic surfactant selected from the group consisting of KILFHENYL ETHER or a hydrolyzate thereof and a surfactant part of 40 to 60% by weight and having a width of 2 to 5 nm and a length of 10 to 100 nm A method for producing a hydroxyapatite / surfactant complex according to (2), characterized in that a hydroxyapatite / surfactant complex characterized by having an ultra-flaky shape is produced and recovered It is.

  The seventh invention (7) is characterized in that the hydroxyapatite / surfactant complex shown in (1) and (2) is subjected to a baking treatment at a temperature at which the surfactant component in the complex is thermally decomposed. It is the manufacturing method of the hydroxyapatite shown to (3) and (4).

  The eighth invention (8) is characterized in that the baking treatment of the hydroxyapatite / surfactant complex shown in (1) and (2) is performed at 450 ° C. or higher and 800 ° C. or lower in an oxidizing atmosphere. This is a method for producing hydroxyapatite shown in (3) and (4).

  The ninth invention comprises (9) one kind of calcium salt selected from the group consisting of calcium salts such as calcium nitrate and calcium chloride, a group consisting of phosphates such as sodium monohydrogen phosphate and sodium dihydrogen phosphate. A non-ionic surfactant selected from the group consisting of polyoxyethylene alkyl ethers such as nonaethylene glycol monohexadecyl ether, polyoxyethylene fatty acid esters, nitric acid, etc. A reaction mixture consisting of an acid and water is prepared, and then a base such as ammonia is added to the reaction mixture to cause a reaction, whereby a skeleton is constituted by apatite-type crystals mainly composed of calcium phosphate, and a thickness of 5 nm or less. Produces and recovers hydroxyapatite having an ultrathin plate shape with an outer diameter of 10 to 100 nm A method for producing hydroxyapatite having an ultrathin plate shape.

  The tenth invention (10) is an ultrathin film having a skeleton composed of apatite-type crystals mainly composed of calcium phosphate obtained by the production method described in the preceding item (9) and having a thickness of 5 nm or less and an outer diameter of 10 to 100 nm. Hydroxyapatite characterized by having a plate-like form.

In the following, the eleventh to fifteenth inventions present inventions relating to the use of the hydroxyapatite of the first to fourth and tenth inventions.
That is, the eleventh invention (11) is characterized in that the hydroxyapatite according to any one of (1) to (4) and (10) is used for an application based on its physical properties. Material.
The twelfth invention is (12) the functional material according to (11), characterized in that the use thereof is provided and used as a medical scaffold material.
A thirteenth aspect of the invention is (13) the functional material according to (12), characterized in that the use thereof is exclusively used and used as a dental material.
The fourteenth invention is (14) the functional material according to (12), characterized in that its use is exclusively provided and used as an artificial bone material.
A fifteenth aspect of the present invention is (15) the functional material according to the above (11), characterized in that its use is exclusively used as a toothpaste base.
A sixteenth aspect of the invention is (16) the functional material described in (11) above, characterized in that its use is exclusively used as a basic cosmetic.
A seventeenth aspect of the invention is (17) the functional material as described in (11) above, wherein the use is provided and used exclusively as a chromatography filler.
An eighteenth aspect of the invention is (18) the functional material described in (11), characterized in that its use is exclusively used as an ion exchanger.
The nineteenth invention is (19) the functional material according to (11), characterized in that its use is exclusively used as a carrier for catalyst components such as acid-base catalysts, oxidation-reduction catalysts, and photocatalysts. It is.
The twentieth invention is the functional material according to (11), characterized in that (20) its use is provided and used exclusively as an antibacterial agent supporting silver.
A twenty-first invention is the functional material according to (11), characterized in that (21) its use is provided and used exclusively as a sensor for measuring humidity and condensation.

  The present invention provides a new template structure, novel form, novel structure with ultra-fine nanostructure, high surface area by designing a specific template material that is selected or combined with a specific surfactant. As a result of the successful synthesis of the hydroxyapatite in properties, it is expected that unique properties will be manifested in other applications as well as in the conventional mode of use in apatite. The field of application and use is not particularly limited, and can be used for material design in all technical fields. It is expected that the nano-level microstructure that it possesses will exhibit physical and chemical properties that could not be achieved so far and will contribute widely to industrial development. In particular, it is expected to lead to better material design due to its high surface area, uniformity of micro outer shape at the nanostructure level, and abundant types. In other words, in addition to medical use, in various fields such as feed, food, electronic materials, etc., as well as advanced medical scaffold material design and advanced pharmaceutical design with sustained release due to its high adsorption / support capacity Used and expected to exert great power.

The invention of this application has the above-described features, and will be specifically described below with reference to the accompanying drawings. However, these examples merely disclose one aspect of the present invention, and are not intended to limit the present invention. That is, the aim of the present invention is to provide high surface area flaky particles having hydroxyapatite as a skeleton, as described above. The contained components and structure are flaky particles of a specific size with an apatite-type structure having calcium phosphate as a main component and a hydroxyl group or an anion group in which a part or all of the group is substituted with a carbonate group as a subsidiary component. In addition to the fact that the constituent components allow a variety of compositional combinations with respect to the subcomponents, defects are easily introduced into the skeletal structure also with respect to the main components, so a wide variety of combinations are included. It is a waste.
In addition, the outline of the manufacturing method is that a specific size is obtained by precipitation reaction between a calcium phosphate component and a base using a structure obtained by mixing two or one type of surfactant and an acidic aqueous solution of calcium phosphate under appropriate conditions. The temperature varies according to the characteristics of the surfactant and the base used, and the optimum temperature for mixing the template, the mixing conditions, and the reaction conditions with the base. On the other hand, an Example shows only the example of the aspect with respect to this invention, and the component and manufacturing method which comprise this invention should not be limited by this Example.

  1 (a), (b), (c), and (d) are photographs of a high surface area hydroxyapatite of the present invention observed with a transmission electron microscope. According to this, the hydroxyapatite structure of the present invention has a width 5-9 nm, chain-type ultrathin flakes with a length of 50 nm or more, thickness 1-5 nm, width 2-5 nm, strip-shaped ultrathin flakes with a length of 10-100 nm, or thickness 5 nm or less, outer diameter 10 It was observed and confirmed to have a thin plate-like structure of 100 nm.

After mixing calcium nitrate tetrahydrate (Ca (NO ₃ ) ₂ .4H ₂ O), sodium hydrogen phosphate (KH ₂ PO ₄ ) and water, 0.014 mol / ml nitric acid was added to prepare a calcium phosphate solution. To this solution, nonaethylene glycol monodecyl ether (C ₁₂ EO ₉ ; manufactured by Nikkor Chemical) was added and heated to 60 ° C. to obtain a homogeneous solution. Subsequently, polyoxyethylene (20) sorbitan monostearate at the same temperature. (Tween 60; manufactured by Wako Pure Chemical Industries, Ltd.), shaken, cooled to 25 ° C., charged molar ratio Ca (NO ₃ ) ₂ : KH ₂ PO ₄ : C ₁₂ EO ₉ : Tween 60: HNO ₃ : H ₂ O = A reaction precursor of 1.67: 1: 1: 1: 8: 60 was obtained. Next, ammonia at twice the molar amount of nitric acid at the same temperature was added as 0.014 mol / dm ³ ammonia water and reacted for 48 hours, and then the solid phase was centrifuged, washed with water and ethanol in this order and dried to give a white powder. Got.
Observation by a transmission electron microscope confirmed that the main product of the powder was a chain particle having a width of 6 to 8 nm and a length of more than 50 nm (FIG. 1A). Further, in the XRD pattern, a series of broad diffraction peaks attributed to low crystalline apatite appear in the angle range of 2θ = 20 ° to 60 ° (FIG. 2A), and phosphoric acid is observed in the FT-IR spectrum. with a peak of 1035 cm ^-1 derived from groups, sharp absorption peak derived from an alkyl group of each surfactant 2923Cm ^-1 and 2849cm ^-1 were observed (Figure 3 (a)). Furthermore, the atomic ratio of Ca and P contained in the powder was 1.62 by EDX analysis, and it was also confirmed that this substantially coincided with the theoretical value 1.67 of the apatite composition. The thermogravimetric (TG) curve shows a 46 wt% weight loss due to thermal decomposition of the composite surfactant at 200 ° C. to 400 ° C. (FIG. 4A), and is highly crystalline hydroxyapatite at 1000 ° C. It was also found out. In addition, a series of diffraction peaks derived from the layered structure of d = 5.4 nm observed in the low-angle region of the XRD pattern (FIG. 2A) are partly observed by transmission electron microscope observation, and the apatite layer It is presumed to be derived from a layered composite in which surfactant layers are alternately laminated. From the above results, the powder obtained by the above reaction is a chain-type ultrathin with a main product consisting of a hydroxyapatite component and a surfactant component in a weight ratio of 52:46 and a width of 6 to 8 nm and a length of more than 50 nm. It was identified as a flake complex.
The baked product obtained by heating the powder in air at 500 ° C. for 5 hours is a low crystalline apatite from which the organic components have been completely removed. FT-IR spectrum (FIG. 3B) And the XRD pattern (FIG. 2B). A diffraction peak of d = 5.4 nm or less derived from the layered structure also disappeared. Furthermore, it was also confirmed by observation with a transmission electron microscope that the chain-like ultrathin flake form before firing was retained after firing (FIG. 1 (B)). The 500 ° C. fired product has a remarkably large surface area of 360 m ² · g ^−1, and the particle thickness estimated using a hydroxyapatite density of 3.2 g / cm ³ is 2.6 nm.

In Example 1 above, the amount of nitric acid added was reduced to 1/16 times, and the charged molar ratio was Ca (NO ₃ ) ₂ : KH ₂ PO ₄ : C ₁₂ EO ₉ : Tween 60: HNO ₃ : H ₂ O == 1. A powder sample was synthesized by the same procedure using the reaction precursor at 67: 1: 1: 1: 0.5: 60. The obtained powder contains a surfactant component of 17 wt% (FIG. 4 (B)), and when only Tween 60 is used in the same manner as the plate-like particles generated when only C ₁₂ EO ₉ is used as the surfactant. It was observed that it was a mixture of strip-like ultrathin flaky particles produced in (Fig. 1 (C)). In the XRD pattern, only the diffraction peak attributed to the low crystalline apatite of 2θ = 20 ° to 60 ° was observed, and the low-angle peak due to the layered structure disappeared (FIG. 2C).

As in Example 1, calcium nitrate tetrahydrate (Ca (NO ₃ ) ₂ .4H ₂ O), sodium hydrogen phosphate (KH ₂ PO ₄ ) and water were mixed, and then 0.014 mol / ml nitric acid was added. To prepare a calcium phosphate solution. To this solution, polyoxyethylene (20) sorbitan monostearate (Tween 60; manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was heated and stirred to 60 ° C. to make a uniform solution, then cooled to 25 ° C. and charged molar ratio Ca ( A reaction precursor of NO ₃ ) ₂ : KH ₂ PO ₄ : Tween 60: HNO ₃ : H ₂ O = 1.67: 1: 11: 8: 60 was obtained. Next, ammonia at twice the molar amount of nitric acid at the same temperature was added as 0.014 mol / dm ³ ammonia water and reacted for 48 hours, and then the solid phase was centrifuged, washed with water and ethanol in this order and dried to give a white powder. Got.
By observation with a transmission electron microscope, this powder was confirmed to be strip-shaped ultrathin flaky particles having a width of 2 to 4 nm and a length of several tens of nanometers (FIG. 1D). Further, in the XRD pattern, a series of broad diffraction peaks attributed to low crystalline apatite appear in the angle range of 2θ = 20 ° to 60 ° (FIG. 2D), and phosphoric acid is shown in the FT-IR spectrum. with a peak of 1035 cm ^-1 derived from groups, sharp absorption peak derived from an alkyl group of each surfactant 2923Cm ^-1 and 2849cm ^-1 were observed (Fig. 3 (C)). Furthermore, the atomic ratio of Ca and P contained in the powder was 1.62 by EDX analysis, and it was also confirmed that this substantially coincided with the theoretical value 1.67 of the apatite composition. The thermogravimetric (TG) curve showed a weight loss of 43 wt% due to thermal decomposition of the composite surfactant at 200 ° C. to 400 ° C. (FIG. 4C). In addition, a series of diffraction peaks derived from the layered structure of d = 5.4 nm observed in the low angle region of the XRD pattern (FIG. 2 (A)) was observed by a transmission electron microscope as in the case of Example 1. It is presumed that the apatite layer and the surfactant (Tween 60) layer partially recognized are derived from a layered composite in which layers are alternately laminated. From the above results, the powder obtained by the above reaction has a strip shape whose main product is a hydroxyapatite component having a weight ratio of 55:43 and a surfactant component, having a width of 2 to 4 nm and a length of more than several tens of nm. It was identified to be an ultra-flaky particle composite.
From the FT-IR spectrum and the XRD pattern, it was confirmed that the fired product obtained by heating the powder at 500 ° C. in air for 5 hours was a low crystalline apatite from which organic components were completely removed. A diffraction peak of d = 5.4 nm or less derived from the layered structure also disappeared. Furthermore, it was also confirmed by observation with a transmission electron microscope that the strip-like ultrathin flake form before firing was retained after firing (FIG. 1 (E)). It was also found that the surface area of the fired product at 500 ° C. was remarkably large as 150 m ² · g ⁻¹ .

As in Example 1, calcium nitrate tetrahydrate (Ca (NO ₃ ) ₂ .4H ₂ O), sodium hydrogen phosphate (KH ₂ PO ₄ ) and water were mixed, and then 0.014 mol / ml nitric acid was added. To prepare a calcium phosphate solution. To this solution, nonaethylene glycol monodecyl ether (C ₁₂ EO ₉ ; manufactured by Nikkor Chemical) was added and heated to 60 ° C. to make a uniform solution, then cooled to 25 ° C., and charged molar ratio Ca (NO ₃ ) ₂ : KH ₂ PO ₄ : C ₁₂ EO ₉ : HNO ₃ : H ₂ O = 1.67: 1: 11: 8: 60 was obtained. Next, ammonia at twice the molar amount of nitric acid at the same temperature was added as 0.014 mol / dm ³ ammonia water and reacted for 48 hours, and then the solid phase was centrifuged, washed with water and ethanol in this order and dried to give a white powder. Got.
It was observed with a transmission electron microscope that the powder was a plate-like particle having a thickness of ˜2 nm (FIG. 1 (F)). Further, in the XRD pattern, a series of broad diffraction peaks attributed to low crystalline apatite appeared in the angle range of 2θ = 20 ° to 60 ° (FIG. 2 (F)). The FT-IR spectrum with peaks of 1035 cm ^-1 derived from a phosphate group, was observed in the weak absorption peak 2923cm ^-1 and 2849cm ^-1 derived from an alkyl group of trace amounts of surfactant. The weight loss that appeared in the thermogravimetric (TG) curve was also only about 1.7 wt%. Furthermore, the atomic ratio of Ca and P contained in the powder was 1.62 by EDX analysis, and it was also confirmed that this substantially coincided with the theoretical value 1.67 of the apatite composition. From the above results, it was identified that the powder obtained by the above reaction was a plate-like hydroxyapatite particle having a thickness of 2 nm or less.

  As described above, the present invention is a hydroxyapatite having a novel shape, a new size, a new surface area, and a new physical property, which are fundamentally different from these, with various research reports and prior arts in mind. The bioaffinity, electrochemical properties, and ion exchange properties of hydroxyapatite are further improved due to its unique physical and chemical properties, and chemically derived from its high surface area. The present invention provides a material that specifically expresses an excellent function, and even if the availability is specifically mentioned, the main usage modes are as described in claims 12 to 20, Examples include medical scaffold materials, adsorbents, ion exchangers, catalysts or catalyst carriers, additives for basic cosmetics, foods, feeds, and the like. Again, since the present invention basically provides a novel hydroxyapatite, the present invention itself provides a useful invention, and it is greatly used in technical fields other than the above-described use modes, and thus is industrially used. I am confident that it will contribute to the development of

(A) Observation by transmission electron microscope of the hydroxyapatite / surfactant complex obtained in Example 1 (b) The hydroxyapatite / surfactant complex obtained in Example 1 was baked at 500 ° C. (C) Observation diagram of the hydroxyapatite / surfactant composite obtained in Example 2 with a transmission electron microscope (d) Example 3 Of transmission electron microscope of hydroxyapatite (including some surfactants) (A) X-ray diffraction pattern of hydroxyapatite / surfactant complex obtained in Example 1 (b) Obtained by baking the hydroxyapatite / surfactant complex obtained in Example 1 at 500 ° C. X-ray diffraction pattern of the fired body (hydroxyapatite) (c) X-ray diffraction of the fired body (hydroxyapatite) obtained by firing the hydroxyapatite / surfactant complex obtained in Example 1 at 1000 ° C. Figure (d) X-ray diffraction pattern of hydroxyapatite / surfactant complex obtained in Example 3 (e) X-ray diffraction pattern of hydroxyapatite (partially including a surfactant) obtained in Example 4 (A) Fourier transform infrared absorption FT-IR spectrum of the hydroxyapatite / surfactant complex obtained in Example 1 (b) The hydroxyapatite / surfactant complex obtained in Example 1 at 500 ° C. FT-IR spectrum of calcined product (hydroxyapatite) obtained by firing (c) FT-IR spectrum of hydroxyapatite / surfactant complex obtained in Example 3 (d) Obtained in Example 4 FT-IR spectrum of hydroxyapatite (including some surfactants) (A) Thermogravimetric (TG) curve of the hydroxyapatite / surfactant complex obtained in Example 1 (b) TG curve of the hydroxyapatite / surfactant complex obtained in Example 3 (c) Implementation TG curve of hydroxyapatite (partially containing a surfactant) obtained in Example 4

Claims (21)

  Apatite type crystal part mainly composed of calcium phosphate, polyoxyethylene sorbitan ester such as polyoxyethylene sorbitan monostearate, one kind of nonionic surfactant selected from the group consisting of polyoxyethylene alkyl phenyl ether, or the above Two types of nonionic surfactants comprising a single nonionic surfactant selected from the group consisting of polyoxyethylene alkyl ethers such as nonaethylene glycol monohexadecyl ether and polyoxyethylene fatty acid esters Alternatively, hydroxyapatite / composed of 40 to 60% by weight of a hydrolyzate product and having a chain ultrathin flake shape having a width of 5 to 9 nm and a length of 50 nm or more. Surfactant complex.   Nonionic surfactant selected from the group consisting of apatite-type crystal parts mainly composed of calcium phosphate, polyoxyethylene sorbitan esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene alkyl phenyl ether, or hydrolyzed products thereof Hydroxyapatite / surfactant composite characterized by comprising 40 to 60% by weight of a surfactant part and having a strip-like ultrathin flake shape having a width of 2 to 5 nm and a length of 10 to 100 nm body. The hydroxyapatite / surfactant complex according to claim 1 is obtained by performing a baking treatment at a temperature at which the surfactant component in the complex is thermally decomposed, and has a chain shape having a width of 5 to 20 nm and a length of 50 nm or more. Hydroxyapatite characterized by having an ultra-flaky form and a high surface area of 300 m ² / g or more. The hydroxyapatite / surfactant complex according to claim 2 is obtained by baking at a temperature at which the surfactant component in the complex is thermally decomposed, and has a thickness of 1 to 5 nm, a width of 2 to 5 nm, and a length. Hydroxyapatite having a strip-like ultrathin shape with a thickness of 10 to 100 nm and a high surface area of 150 m ² / g or more   One kind of phosphoric acid selected from the group consisting of a calcium salt selected from the group consisting of calcium salts such as calcium nitrate and calcium chloride, and a phosphate such as sodium monohydrogen phosphate and sodium dihydrogen phosphate A nonionic surfactant selected from the group consisting of salts, polyoxyethylene sorbitan esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl such as nonaethylene glycol monohexadecyl ether Prepare a reaction mixture comprising a nonionic surfactant selected from the group consisting of ethers and polyoxyethylene fatty acid esters, an acid such as nitric acid and water, and then add a base such as ammonia to the reaction mixture. By reacting, phosphate One nonionic surfactant selected from the group consisting of apatite-type crystal parts mainly composed of sium, polyoxyethylene sorbitan esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene alkyl phenyl ether, or nonaethylene Two types of nonionic surfactants or their hydrolysis products in combination with one nonionic surfactant selected from the group consisting of polyoxyethylene alkyl ethers such as glycol monohexadecyl ether and polyoxyethylene fatty acid esters A hydroxyapatite / surfactant complex characterized in that it comprises a chain part of ultrathin flakes having a width of 5 to 9 nm and a length of 50 nm or more. Generated and recovered The method for producing hydroxyapatite / surfactant complex.   One kind of phosphoric acid selected from the group consisting of a calcium salt selected from the group consisting of calcium salts such as calcium nitrate and calcium chloride, and a phosphate such as sodium monohydrogen phosphate and sodium dihydrogen phosphate Prepare a reaction mixture consisting of a salt, a polyoxyethylene sorbitan ester such as polyoxyethylene sorbitan monostearate, a nonionic surfactant selected from the group consisting of polyoxyethylene alkylphenyl ether, an acid such as nitric acid and water. Then, by adding a base such as ammonia to the reaction mixture and reacting it, an apatite type crystal part mainly composed of calcium phosphate, polyoxyethylene sorbitan ester such as polyoxyethylene sorbitan monostearate, polyoxyethylene alkyl Phenille A It is composed of 40 to 60% by weight of a surfactant part made of a nonionic surfactant selected from the group consisting of ruthenium, and has a strip-like ultrathin flaky shape with a width of 2 to 5 nm and a length of 10 to 100 nm. The method for producing a hydroxyapatite / surfactant complex according to claim 2, wherein the hydroxyapatite / surfactant complex is produced and recovered.   The hydroxyapatite / surfactant complex according to claim 1 or 2 is subjected to a baking treatment at a temperature at which the surfactant component in the complex is thermally decomposed. Production method.   The method for producing hydroxyapatite according to claim 3 or 4, wherein the baking treatment is performed at 450 ° C or higher and 800 ° C or lower in an oxidizing atmosphere.   One kind of phosphoric acid selected from the group consisting of a calcium salt selected from the group consisting of calcium salts such as calcium nitrate and calcium chloride, and a phosphate such as sodium monohydrogen phosphate and sodium dihydrogen phosphate Prepare a reaction mixture consisting of a salt, a nonionic surfactant selected from the group consisting of polyoxyethylene alkyl ethers such as nonaethylene glycol monohexadecyl ether, polyoxyethylene fatty acid esters, acid such as nitric acid and water Then, by adding a base such as ammonia to the reaction mixture and reacting it, a skeleton is constituted by apatite-type crystals mainly composed of calcium phosphate, and an ultrathin plate having a thickness of 5 nm or less and an outer diameter of 10 to 100 nm. Hydroxyapatite characterized by having a morphological shape is produced and recovered. A method for producing hydroxyapatite having an ultrathin plate-like form.   The skeleton is constituted by apatite-type crystals mainly composed of calcium phosphate obtained by the production method according to claim 9, and has an ultrathin plate shape having a thickness of 5 nm or less and an outer diameter of 10 to 100 nm. Hydroxyapatite   A hydroxyapatite or a hydroxyapatite / surfactant complex according to any one of claims 1 to 4 and claim 10 is used, comprising one or more, and used for applications based on the physical properties thereof. Functional material characterized by   The functional material according to claim 11, wherein the functional material is used and used exclusively as a medical scaffold material.   13. The functional material according to claim 12, wherein the functional material is exclusively used and used as a dental material.   The functional material according to claim 12, wherein the functional material is used and used exclusively as an artificial bone material.   The functional material according to claim 11, wherein the functional material is used and used exclusively as a toothpaste base.   The functional material according to claim 11, wherein the functional material is used and used exclusively as a basic cosmetic.   The functional material according to claim 11, wherein the functional material is used and used exclusively as a chromatography filler.   The functional material according to claim 11, wherein the functional material is used and used exclusively as an ion exchanger.   12. The functional material according to claim 11, wherein the functional material is used and used exclusively as a carrier for catalyst components such as an acid-base catalyst, a redox catalyst, and a photocatalyst.   The functional material according to claim 11, wherein the functional material is used and used exclusively as an antibacterial agent supporting silver. The functional material according to claim 11, wherein the functional material is used and used exclusively as a sensor for measuring humidity and dew condensation.