JP5278897B2 - Method and apparatus for manufacturing ceramic precision sphere by hydrocasting - Google Patents

Description

  The present invention relates to a method for manufacturing ceramic precision spheres and an apparatus therefor, and more specifically, the present invention prepares an aqueous slurry containing a ceramic raw material, a gelling agent, and a coagulant, The molded spherical slurry is formed into a spherical shape that is left to surface tension in the molding liquid by dispensing and dispensing in a constant amount into the molding liquid of the standing molding liquid-coagulating liquid multistage reaction system. A method for producing ceramic precision spheres, which are fixed in a precise spherical shape by gelling and retaining the shape simultaneously, immersing the spherical slurry gel in the coagulating liquid of the reaction system and coagulating in multiple stages; The present invention relates to a ceramic sphere manufacturing apparatus. The present invention provides a new ceramic precision sphere by hydrocasting, which makes it possible to manufacture a large number of ceramic precision spheres of ceramics or ceramic precursors having a uniform particle size with high precision with simple processes and means. It provides new technologies and products related to manufacturing.

  In general, there are various uses for precision spheres, such as bearings, pump valves, various valves, colored display spheres, float balls, agitation / grinding media, and medical instruments. As a manufacturing method of the precision sphere, a drop droplet method and a cutting polishing method are generally used. Among these, the falling droplet method is a method in which a material in a molten state or a slurry state is dropped, and in a microgravity environment during the dropping, the material is subjected to surface tension and solidified (FIG. 1).

  The falling material is solidified by drying the falling material during dropping or by landing the falling material on the coagulating liquid. This method is characterized in that the falling material takes a precise spherical shape under ideal conditions. With respect to this method, as a prior art, for example, when producing ceramic particles via gel particles, the droplets of the gel solution manufacturing stock solution are dropped, and the falling droplets are gelled by dielectric heating to form microparticles. A gel particle manufacturing method (Patent Document 1) has been proposed in which a wave power source is used to give a necessary temperature increase to the internal gel of a droplet and the resonance state of the resonator is finely adjusted.

  In addition, the cutting polishing method is a method in which a material is formed into a rough sphere by a forging machine (header machine) to form a sphere (with burr), and then adjusted to a true sphere (without burr) by various polishing methods. (FIG. 2). This method is particularly effective as a method for obtaining a dense and high-strength sphere, and is used, for example, in the manufacture of ball bearings.

  With regard to this method, as a prior art, for example, a cut piece obtained by cutting a rod-shaped material made of a material mainly composed of aluminum is forged by semi-sealing die forging to form an aluminum ball, and burrs are formed. A method (Patent Document 2) for removing and manufacturing an aluminum ball has been proposed.

  However, in the falling droplet method, the falling droplet does not stop perfectly in a spherical shape, and is constantly vibrating, so it rarely becomes a true sphere. It is difficult to prevent falling material from flattening when it falls into the coagulation liquid or sinking into the coagulation liquid so that some of the droplets are constrained by the coagulation liquid surface and become a tear-type coagulum. It is.

  In addition, since the material often forms unintended splashes immediately before dropping, that is, at the moment of leaving the material discharge nozzle, it is inevitable to select the material loss at the time of manufacture and the obtained solidified product. Further, this method cannot drop the material by an extremely small amount, that is, cannot be separated from the material discharge nozzle, and is not suitable for manufacturing a small precision sphere.

  In addition, as another method, there is a method of forcibly separating a small amount of material from the nozzle by vibrating the material discharge nozzle, but special consideration is necessary for maintaining the nozzle state, and the method itself is However, there are many places that are dominated by know-how, and there are problems in using it simply, scientifically and with reproducibility.

  In addition, this method requires a relatively large device such as a header machine or a polishing machine. For example, it is not practical to introduce this method into a manufacturing process of biomaterials that is bound by strict standards. Absent. In addition, the cutting and polishing method requires a material loss in the polishing process, and a polishing method peculiar to the material is necessary. Further, the cutting and polishing method is generally used for manufacturing microspheres. It is said that it is not applicable.

  Fine and precise molded products can be manufactured by the maturation of injection molding technology, but generally, productivity is poor, selection of a binder is difficult, and a precise mold is expensive. For example, in order to make a ceramic precision sphere with a diameter of 1 mm, an injection mold precision mold that can be made with 12 pieces / shot (1 minute) is quite expensive.

  As another method, a method such as an emulsion method in which spherical particles are obtained by drying a raw material droplet in the oil by discharging the slurry into the oil and stirring vigorously (FIG. 3). With respect to this method, as a prior art, for example, a droplet of polyamic acid spheres encapsulated in oil produced in oil is dispersed by a stirring means to form an emulsion, and the polyamic acid spheres are chemically imidized. Has proposed a method for producing a true spherical polyimide (Patent Document 3).

  However, in this type of method, the method of controlling the particle size of the spherical particles is the stirring rotation speed, and as the stirring is performed at a higher rotation speed, the slurry is broken to aim at small spherical particles. It is difficult to establish a correlation with Further, collision between particles, particles and container, particles and stirrer (stirring bar) leads to deformation of the particle shape, and furthermore, means for fixing the spherical shape of the slurry is poor. Therefore, this type of method results only in obtaining a boulder-mixed spherical particle group, and is inevitable of particle deformation, sorting, material loss, and the like.

Japanese Patent No. 3462562 JP 2003-145247 A JP 2002-265625 A

  Under such circumstances, in view of the prior art, the present inventor has developed a new ceramic precision sphere manufacturing method and a ceramic precision sphere manufacturing apparatus capable of reliably solving the problems in the prior art. We have earnestly researched with the goal of developing.

  As a result, the inventor of the present invention is a molding liquid-coagulating liquid in which an aqueous slurry containing a ceramic raw material powder slurry (hereinafter sometimes simply referred to as a slurry), a gelling agent, and a coagulant is allowed to stand. Dispensing and dispensing a fixed amount into a molding liquid of a multi-stage reaction system, and forming a slurry that has a shape (spherical shape) that can be left to surface tension in the molding liquid. It was found that the intended purpose can be achieved by performing these reactions in multiple stages by using the fixing step according to the above, and the present invention has been completed. An object of the present invention is to provide a method for producing ceramic precision spheres and an apparatus for producing the ceramic precision spheres by an injection molding technique using the liquid itself made of the molding liquid as a mold. .

The present invention for solving the above-described problems comprises the following technical means.
(1) A method for producing a precision ceramic sphere of precise or uniform grain size or a precursor thereof,
1) An aqueous slurry containing a ceramic raw material, a gelling agent, and a coagulant that coagulates in a coagulating liquid is prepared, and the slurry is placed in a molding liquid of a multistage reaction system of a standing molding liquid-coagulating liquid. By dispensing and dispensing in a constant amount, it is formed into a spherical shape of a precise spherical shape left to the surface tension in the molding liquid, and the spherical shape slurry is gelled simultaneously, thereby producing a precise spherical shape. A shape retaining process, and
2) A step of fixing a precise spherical shape by immersing the retained spherical slurry gel in the coagulating liquid of the above reaction system to form a precise sphere,
Consists of
In extent on climate, be prepared and the ceramic raw material, agarose, gelatin, pectin, or a gelling agent consisting of a surfactant or mixtures thereof, an aqueous slurry containing a coagulant consisting of sodium alginate, the molding solution A method for producing ceramic precision spheres, characterized in that mineral oil, vegetable oil, synthetic oil, liquid paraffin, or collagen aqueous solution is used, and a polyvalent metal ion aqueous solution is used as the coagulating liquid .
(2) The slurry was allowed to stand by using a multi-stage reaction system composed of a multi-layer structure forming liquid-coagulating liquid formed in the same container as the forming liquid-coagulating liquid multi-stage reaction system. Molded liquid-Solid slurry formed into a precise spherical shape that is left to surface tension in the molding liquid by dispensing and dispensing into the upper layer molding liquid of the multi-stage reaction system of the molding liquid and coagulation liquid. The spherical shape of the spherical slurry gel is kept at the same time by gelling, and then the spherical spherical shaped gel is left to settle and immersed in the coagulating liquid of the reaction system. The method for producing a ceramic precision sphere according to (1), wherein the ceramic sphere is fixed to be a precision sphere.
(3) The method for producing ceramic precision spheres according to (1) or (2), wherein the ceramic raw material is calcium phosphate powder.
(4) Calcium phosphate is hydroxyapatite, carbonate apatite, fluorapatite, chlorapatite, β-TCP, α-TCP, calcium metaphosphate, tetracalcium phosphate, calcium hydrogen phosphate, or calcium hydrogen phosphate dihydrate. The method for producing a ceramic precision sphere according to the above (3), which is one kind selected from the group or a mixture of two or more kinds.
(5) The molding liquid according to any one of (1) to (4), wherein 1) mineral oil, vegetable oil, or synthetic oil, 2) liquid paraffin, or 3) a collagen aqueous solution. Manufacturing method of ceramic precision spheres.
(6) The method for producing ceramic precision spheres according to any one of (1) to (5), wherein the coagulation liquid is a polyvalent metal ion aqueous solution.
(7) The method for producing a ceramic precision sphere according to any one of (1) to (6), wherein the slurry that is quantitatively discharged into the forming liquid is gelled by a temperature drop.
(8) The method for producing a ceramic precision sphere according to any one of (1) to (7), wherein the quantitative discharge is performed by an air pulse dispenser, a plunger dispenser, a digital pipette, or a syringe.
(9) Production of ceramic precision spheres characterized by drying, firing, or sintering after drying ceramic precursor ceramic spheres obtained by the method according to any one of (1) to (8). Method.
(10) An aqueous slurry containing a ceramic raw material, a gelling agent composed of agarose, gelatin, pectin, or a surfactant or a mixture thereof, and a coagulant composed of sodium alginate that coagulates in the coagulation liquid was allowed to stand. A means for dispensing and dispensing quantitatively into the molding liquid of the reaction system of the molding liquid- coagulating liquid means , and molding and gelling the slurry that has been dispensed and dispensed into a precise spherical shape left to the surface tension. A first reactor for storing a molding liquid for retaining the shape as a molding liquid layer, and a spherical slurry shaped and gelled into a precise spherical shape and immersed to fix the spherical slurry the coagulating solution comprises a second reactor containing a coagulating liquid layer, and in the first reactor, as a molding liquid of the molding liquid layer, mineral oils, vegetable oils, synthetic oils, liquid paraffin, or collagen solution Volume, and in the second reactor, as a coagulating solution for coagulating liquid layer, ceramic precision ball production apparatus is characterized in that so as to accommodate the polyvalent metal ion solution.
(11) A multistage reaction system composed of a molding liquid layer of the molding liquid contained in the first reactor and a coagulation liquid layer of the coagulation liquid contained in the second reactor is accommodated in a layer in the same container, By using the specific gravity difference to form the upper forming liquid-lower coagulating liquid, the forming liquid layer of the forming liquid contained in the first reactor and the coagulating liquid layer of the coagulating liquid contained in the second reactor. Are produced in a multilayer shape, and a multistage reaction comprising a molding liquid-coagulating liquid having a multilayer structure is carried out in a single stage reaction apparatus.

Next, the present invention will be described in more detail.
The present invention relates to a method for producing a precision ceramic sphere of precise and uniform particle size or a precursor thereof, an aqueous slurry containing a ceramic raw material, a gelling agent, and a coagulant that coagulates in a coagulating liquid. A precise spherical sphere was left to the surface tension in the molding liquid by quantitatively discharging and dispensing the slurry into a molding liquid of a multistage reaction system of a stationary molding liquid-coagulating liquid. Forming into a shape and simultaneously gelling the formed spherical slurry, and maintaining the precise spherical shape, and immersing the retained spherical slurry gel in the coagulating liquid of the reaction system Thus, the method includes a step of fixing a precision sphere shape to form a precision sphere.

  In the present invention, as the multistage reaction system of the molding liquid-coagulating liquid, a multistage reaction system consisting of a multilayered molding liquid-coagulating liquid formed in layers in the same container is used, and the slurry is allowed to stand. The formed spherical liquid is molded into a precise spherical shape that is left to surface tension in the molding liquid by quantitative discharge and dispensing into the upper molding liquid of the multi-stage reaction system of the molded liquid-coagulating liquid. The slurry is gelled simultaneously to maintain a precise spherical shape, and then the retained spherical slurry gel is allowed to settle and immersed in the coagulating liquid of the above reaction system to obtain a precise spherical shape. It is a preferred embodiment to fix the sphere to a precision sphere.

  The present invention is also a ceramic precision sphere manufacturing apparatus used in the above method for manufacturing a ceramic precision sphere, comprising an aqueous slurry containing a ceramic raw material, a gelling agent, and a coagulant solidifying in a coagulating liquid. , A means for quantitatively discharging and dispensing into a molding liquid in a reaction system of a stationary molding liquid, and a slurry that has been dispensed and dispensed into a precise spherical shape that is left to surface tension, and gelled Solidification for immersing and fixing a spherical slurry shaped and gelled into a spherical shape of a precise spherical shape, and a first reactor that contains a molding fluid for shape retention as a molding fluid layer And a second reactor for containing the liquid as a coagulating liquid layer.

  In the present invention, a multistage reaction system composed of a molding liquid layer of the molding liquid stored in the first reactor and a coagulating liquid layer of the coagulating liquid stored in the second reactor is stored in the same container in layers. Forming a molding liquid layer of the molding liquid contained in the first reactor and a coagulation liquid layer of the coagulating liquid contained in the second reactor by forming an upper molding liquid-lower coagulating liquid. In a preferred embodiment, a multi-stage reaction consisting of a molding liquid and a coagulation liquid having a multilayer structure is performed in a single-stage reaction apparatus.

  In the present invention, an aqueous slurry containing a ceramic powder raw material, a gelling agent, and a coagulant is used as the slurry. The ceramic powder has an average particle size of more than 0 to 40 μm, preferably an average particle size of about 7 μm or less, more preferably an average by an appropriate pulverizing means and method such as a ball mill or a jet mill. It is desirable that the particle size is adjusted to about 1.4 μm or less. However, powders pulverized into various particle sizes can be used by appropriately selecting the slurry discharge nozzle and the discharge method.

  In the present invention, calcium phosphate and components equivalent or similar thereto are suitably used as the ceramic powder. Examples of calcium phosphate include hydroxyapatite, carbonate apatite, fluorapatite, chlorapatite, β-TCP, α-TCP, and calcium metaphosphate. , Tetracalcium phosphate, calcium hydrogen phosphate, calcium hydrogen phosphate dihydrate, and the like are exemplified as preferable examples.

  However, the ceramic powder is not limited to these, and can be used in the same manner as long as they have substantially the same effect as these or are similar to these. In the present invention, one or a mixture of two or more selected from these can be used.

The gelling agent, the gelling agent of the temperature-sensitive with the property of gelling is used in the following Jo Tokoro temperature, specifically, agarose, gelatin, pectin or surfactants or mixtures thereof, and using is Ru. Further, pectin and surfactant can be used by adding to agarose and pectin. For example, a slurry to which a 2% agarose aqueous solution has been added is in a liquid state in a reservoir at 40 ° C., and when this is discharged into a molding solution at 40 ° C. or lower, the gelation reaction can proceed slowly with a temperature drop . In the present invention, the gelling agent means a gel that is gelled at a temperature drop, can obtain time until the slurry becomes spherical, and has a slow gelation.

The coagulant, for example, coagulant used et be in the nature of the polyvalent metal ion-sensitive coagulating reacts with polyvalent metal ions, specifically, sodium alginate Ru is used. For example, a slurry to which a 1% sodium alginate aqueous solution is added can be solidified with a 1% calcium chloride polyvalent metal ion aqueous solution . The concentration of A alginic acid sodium aqueous solution can be appropriately prepared. In the present invention, the term “coagulant” means one that can be quickly solidified and can fix the shape of the slurry.

The slurry is formed into a spherical shape by discharging and dispensing the slurry in a stationary liquid (molding solution) that is not easily mixed with the slurry. As the molding liquid, an appropriate one can be selected and used in accordance with the properties of the slurry to be molded. However, when the slurry is water-based, oil such as mineral oil or vegetable oil may be used as the molding liquid. From the viewpoint of ease of molding, it is preferable. The molding liquid, mineral oil, vegetable oils, synthetic oils, liquid paraffin, collagen aqueous solution, the Ru was found using.

  When the slurry is dispensed into the molding liquid, the slurry will soon have a spherical shape left to the surface tension in the molding liquid. By providing the molding liquid with gelation conditions for the gelling agent added to the slurry, gelation can be performed simultaneously with molding. When the gelling agent is agarose, gelation occurs when the molding solution temperature is 40 ° C. or lower. Therefore, it is usually preferable to use a molding solution at about room temperature. When the molding liquid is extremely cooled, gelation of the slurry occurs prior to spheroidization, and a precise spherical shape cannot be obtained.

  The precise spherical gel molded with the molding liquid is fixed in its precise spherical shape by the coagulation liquid. As the coagulation liquid, a polyvalent metal ion aqueous solution, particularly, an aqueous solution containing calcium ions is used. This coagulation liquid can be selected and used according to the type of the selected coagulant. However, when the ceramic powder is calcium phosphate and the coagulant is sodium alginate, an aqueous solution of calcium chloride is used. It is preferable to use a coagulation liquid from the viewpoint of simplicity. However, the present invention is not limited to these, and any one having substantially the same effect as these or similar to these can be used in the same manner.

  The precision spherical shape can be fixed in a slurry and in a separate reaction vessel, but simply use a coagulation liquid that has a higher specific gravity than the molding liquid and does not mix with the molding liquid. In the same reaction vessel, it is preferable that the coagulating liquid is disposed in the lower layer of the molding liquid and the reaction is performed in a reaction system having a multilayer structure of the molding liquid layer and the coagulating liquid layer. In this case, the precision spherical gel can be immersed in the underlying coagulation liquid, leaving it settled. However, the present invention is not limited to these, and any one having substantially the same effect as these or similar to these can be used in the same manner.

  Ceramic solid spheres can be obtained by drying and sintering the solidified ceramic precursor prepared as described above according to the intended use, but the solidified solid is wet without drying and sintering. It is also possible to use it in the state as appropriate. At this time, when the ceramic raw material is a ceramic powder that can be expected to be hydrated and hardened, for example, α-TCP, a mixture of TTCP and DCPD, etc. A strong precision sphere can be obtained.

  In the present invention, the gelling agent and the coagulant do not distinguish the essential difference between the mechanisms of gelation and coagulation, but distinguish them according to their roles. The role of the gelling agent and coagulant is to keep the shape of the gelling agent by suppressing the deformation that occurs when the slurry reacts with the coagulant, and the coagulant can handle the retained slurry. It must be firmly fixed and fixed. As the gelling agent, a gelling agent that does not react with the molding liquid and has a slow gelation is used so as not to clog the slurry discharge nozzle. As the coagulant, there is used a coagulant capable of obtaining coagulation strength capable of withstanding the recovery of spherical particles and deformation due to its own weight by rapid coagulation.

  In the present invention, an aqueous slurry containing ceramic powder, a gelling agent, and a coagulant is used as the slurry. The slurry is formed into a spherical shape by dispensing and dispensing the slurry in a stationary liquid (molding solution) that is not easily mixed with the slurry. By giving the molding liquid conditions for gelling the gelling agent, the slurry dispensed in the molding liquid becomes a precision spherical gel left to the surface tension in the molding liquid. A precision sphere can be obtained by immersing the gelled slurry in a coagulation liquid to fix the precise sphere shape.

  Dispensing and dispensing slurry in a stationary molding liquid layer-coagulation liquid layer can be said to be injection molding limited to a spherical shape, but in the case of the present invention, it is expensive as in normal injection molding. No need for molds or materials that are wasted as runners. The method and apparatus for producing a ceramic precision sphere according to the present invention are useful as a means that can be suitably used as a means for producing a ceramic sphere having a uniform shape in a simple, material-saving manner and with a low budget.

  In the method for producing a ceramic precision sphere of the present invention, a slurry is discharged and dispensed into a reaction liquid forming liquid of a standing multi-layer liquid (upper layer) and a coagulating liquid (lower layer) by a predetermined volume. Thus, it is formed into a spherical shape. Slurry discharged and dispensed in the molding liquid is constrained by the molding liquid and is a precise solder bender that can be separated from the discharge nozzle, that is, a vendor that requires a constraining surface to separate the discharged material from the nozzle, etc. Can be discharged and dispensed in small amounts. In the present invention, there is no material loss due to slurry scattering or the like, and the obtained spherical particle diameter and the dispersibility thereof can be accurately controlled with high accuracy.

  The discharged and dispensed slurry is placed in a relatively microgravity environment in the molding liquid, becomes a precise spherical shape due to the effect of surface tension in the molding liquid, and gradually gels. After a predetermined time according to the thickness of the molding layer and the slurry discharge amount, the gelled spherical slurry enters the solidified layer and becomes a spherical solidified product. At this time, a precision sphere maintaining a precise spherical shape can be obtained by the action of gelation. The method for producing ceramic precision spheres of the present invention can be suitably used as a means for producing ceramic precision spheres having precisely the same particle size and shape with simple, raw material-saving and low budget.

  The apparatus for producing ceramic precision spheres of the present invention comprises an aqueous slurry containing a ceramic raw material, a gelling agent, and a coagulant that solidifies in a coagulating liquid, in a molding liquid of a reaction system of a molding liquid and a coagulating liquid. Contains a molding liquid layer as a molding liquid layer for dispensing and dispensing a fixed amount into a slurry, and shaping and gelling the slurry that has been dispensed and dispensed into a precise spherical shape that depends on surface tension. And a second reactor for containing a coagulating liquid as a coagulating liquid layer for immersing and fixing a spherical slurry shaped and gelled into a precise spherical shape and retaining the shape. Are provided.

  In the present invention, it is possible to use a batch system in which molding is performed in a first reaction container containing a molding liquid and solidification is performed in a second reaction container containing a coagulation liquid. In addition, a method can be used in which solidification is performed by replacing the molding liquid with a coagulation liquid after molding in a reaction vessel containing the molding liquid. In this case, molding and solidification reactions are performed by appropriately replacing the molding liquid and the coagulation liquid. Further, by utilizing the difference in specific gravity between the molding liquid and the coagulating liquid, it is possible to use a continuous method in which the upper layer molding liquid and the lower layer coagulating liquid are formed in multiple layers in the same reaction vessel, and molding and coagulation are continuously performed. In this case, a multilayer reaction system can be easily and easily formed in one reaction vessel by using an oil-based molding liquid and an aqueous coagulation liquid having a specific gravity different from that.

  In the present invention, a multistage reaction system composed of a molding liquid layer of the molding liquid stored in the first reactor and a coagulating liquid layer of the coagulating liquid stored in the second reactor is stored in the same container in layers. Forming a molding liquid layer of the molding liquid contained in the first reactor by forming a coagulation liquid layer of the upper molding liquid layer-lower layer by utilizing a specific gravity difference between the molding liquid and the coagulation liquid; A coagulating liquid layer of a coagulating liquid contained in the apparatus is formed in a multilayer structure, and a multi-stage reaction composed of a multi-layered forming liquid layer-coagulating liquid layer is performed in a single-stage reaction apparatus. Is preferable.

  The present invention provides a ceramic raw material using a standing multistage reaction system of a forming liquid-coagulating liquid or a multistage reaction system comprising a multi-layered forming liquid layer-coagulating liquid layer formed in the same container in layers. This demonstrates that ceramic precision spheres can be produced in a multi-step process including a step of quantifying, discharging, and dispensing slurry into the molding liquid and a step of immersing the slurry in the coagulation liquid.

  In the ceramic sphere of precision and uniform particle size of the present invention or its precursor, the precision is that the particle size and shape of the particles are precise, and there are no horns and burrs that can be made during the manufacture of beads, Is defined as meaning. The uniform particle size satisfies the specifications required for beads in order to guarantee the porosity and the reproducibility of the gap structure that can be achieved during integration, and empirically, the standard deviation of the long axis length distribution is the average length. This means that it is 5% or less of the axial length. The ceramic precursor is a ceramic material before being converted to ceramic by firing and sintering. The ceramic precision sphere obtained by the present invention means that it is of a high quality characterized by a self-organized, close-packed, close-packed spherical shape that allows an integrated state.

According to the present invention, the following special effects are achieved.
(1) The ceramic raw material slurry is formed into a precise spherical shape in the molding liquid by quantitatively discharging it into the molding liquid of the reaction system of the multilayer liquid consisting of the layer structure of the stationary molding liquid layer and the coagulation liquid layer. Then, it is possible to provide a new ceramic precision sphere manufacturing method and apparatus capable of manufacturing a ceramic precision sphere by solidifying it in a coagulating liquid without deforming the spherical slurry. .
(2) The volume of the spherical particles obtained can be made equal accurately by quantitatively discharging the slurry into a molding solution that is not mixed with the ceramic raw material slurry.
(3) The ceramic sphere slurry is made in the liquid, and the precision sphere-shaped ceramic sphere, which is left to the surface tension, is solidified in a multistage reaction system of a molding liquid and a coagulating liquid. The retained ceramic precision sphere can be manufactured and provided.
(4) A ceramic raw material slurry can be quantitatively discharged into a stationary forming liquid layer-coagulated liquid layer to perform injection molding limited to a spherical shape, and as in normal injection molding. In addition, there is an advantage that expensive materials such as expensive molds and runners are not required.
(5) The method and apparatus for producing a ceramic precision sphere according to the present invention can be suitably used as a means for producing a ceramic sphere having a uniform shape in a simple, material-saving manner and with a low budget.
(6) The precision spheres produced by the present invention are self-organized, close to close-packed, and have a spherical shape that allows an integrated state. For example, a porous artificial bone having a uniform gap structure or a catalyst carrier It can utilize suitably for manufacture.
(7) The precision sphere manufacturing method according to the present invention reduces the amount of wasted material due to cutting and polishing when used for pre-molding of materials used for manufacturing bulk-down spherical particles such as cutting and polishing. Is possible.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

  A commercially available α-TCP powder is used as a ceramic raw material, and the α-TCP powder is further pulverized by a dry jet mill (pulverization pressure: 1.5 MPa), whereby a particle size D50: 1.67 μm, A ceramic powder raw material of pulverized α-TCP powder with Top: 6 μm was prepared. 4 g of the pulverized α-TCP powder, 3 g of a 1% sodium alginate aqueous solution of a coagulant and 3 g of a 2% agarose aqueous solution of a gelling agent were mixed for 10 minutes to prepare a 40% α-TCP slurry. In order to prevent coagulation before use of this α-TCP slurry, the α-TCP slurry was bathed in water at 40 ° C.

  On the other hand, a multistage consisting of a molding liquid-coagulating liquid composed of a molding liquid layer composed of a molding liquid for molding the slurry and a coagulating liquid layer composed of a coagulating liquid for fixing the slurry gel. The multilayer liquid of the reaction system was formed in the same container. In this multilayer liquid, liquid paraffin is used as the molding liquid, and a 1% calcium chloride aqueous solution is used as the coagulation liquid, so that a multilayer liquid having a layer structure of these molding liquid layer and coagulation liquid layer is obtained. It was prepared by forming in a glass container of φ80 × 60. At this time, the thickness of the molding liquid layer and the coagulation liquid layer was 30 mm and 20 mm, respectively.

  Next, 4 μl of α-TCP slurry was discharged and dispensed into the molding layer by a plunger-type dispenser. The discharged α-TCP slurry is formed into a spherical shape with a precise spherical shape left to the surface tension with the molding liquid of the molding layer, and simultaneously gelled and retained, and then the retained spherical slurry is settled. Then, by immersing it in the coagulation liquid of the upper coagulation layer, the precise spherical shape was solidified and fixed to obtain precise spherical particles (wet). FIG. 4 shows a procedure for producing a ceramic precision sphere. FIG. 5 shows a wet α-TCP precision sphere molded into a precision sphere shape. At this time, the average major axis length, standard deviation, and aspect ratio (major axis length / minor axis length) of the spherical particles were 1.9567 mm, 0.0278, and 1.0118, respectively. The axial length was measured by image analysis from an optical microscope image.

  The precision spherical particles (wet) were washed with ultrapure water and then dried overnight at 60 ° C. to obtain precise spherical particles (dry) having a precise and uniform particle size. FIG. 6 shows a dry α-TCP precision sphere formed into a precision sphere shape. At this time, the average axial length and standard deviation of the spherical particles were 1.325 mm and 0.026 (about 2% of the average), respectively. The axial length was directly measured with calipers.

  The precision spherical particles (dried) were sintered at 1400 ° C. to obtain precision spherical ceramics having a precise and uniform particle size. At this time, the average axial length and standard deviation of the precision spherical ceramics were 1.119 mm and 0.011 (about 1% of the average), respectively. The axial length was directly measured with calipers.

  A commercially available hydroxyapatite (HA) powder is used as a ceramic raw material, and 2 g of the hydroxyapatite (HA) powder is wet-pulverized for 30 minutes. The pulverized HA powder and a 1% sodium alginate aqueous solution 3 0.5 g and 3.5 g of 2% agarose aqueous solution were mixed with 1 g of ultrapure water for 10 minutes to obtain a 20% hydroxyapatite (HA) slurry. In order to prevent the HA slurry from solidifying before use, the HA slurry was bathed in water at 40 ° C. The multilayer liquid was prepared in the same manner as in Example 1.

  The HA slurry was discharged and dispensed into the molding liquid of the molding layer by 4 μl by a plunger type dispenser. The discharged HA slurry was formed into a precise spherical shape in the molding layer, and solidified and fixed in the solidified layer to obtain precision spherical particles (wet). FIG. 7 shows a wet HA precision sphere formed into a precision sphere shape. At this time, the average major axis length, standard deviation, and aspect ratio (major axis length / minor axis length) of the spherical particles were 1.9567 mm, 0.0327, and 1.0118, respectively. The axial length was measured by image analysis from an optical microscope image.

  The precision spherical particles (wet) were washed with ultrapure water and then dried overnight at 60 ° C. to obtain precise spherical particles (dry) having a precise and uniform particle size. FIG. 8 shows a dry HA precision sphere molded into a precision sphere shape. At this time, the average axial length and standard deviation of the spherical particles were 1.153 mm and 0.027 (about 2.4% of the average), respectively. The axial length was directly measured with calipers.

  The precision spherical particles (dried) were sintered at 1250 ° C. to obtain precision spherical ceramics having a precise and uniform particle size. At this time, the average axial length and standard deviation of the precision spherical ceramics were 0.845 mm and 0.014 (about 1.7% of the average), respectively. The axial length was directly measured with calipers.

  The α-TCP slurry prepared in Example 1 was discharged into a multilayer liquid similar to that in Example 1 with an air pulse dispenser to produce precision spherical particles (wet). FIG. 9 shows an α-TCP precision sphere in a wet state formed into a precision sphere shape manufactured by an air pulse dispenser and a desktop robot. The discharge conditions of the air pulse dispenser were: air press: 0.03 MPa, Dispense Time: 0.02 sec. It was.

  The air pulse dispenser is mounted on a desktop robot, and can automatically discharge 10 × 10 = 100 grains at intervals of 5 mm until there is no slurry in the reservoir. At this time, the aspect ratio (major axis length / minor axis length) of the precision spherical particles (wet) was 1.0134. The axial length was measured by image analysis from an optical microscope image.

  The spherical slurry droplets were formed by discharging and dispensing 4 μl of 40% α-TCP slurry prepared by the same method as in Example 1 onto the surface of the molding liquid of the liquid paraffin molding layer with a digital pipette. The spherical slurry droplets were cooled with ice in a container containing liquid paraffin, and gelled to such an extent that they would not be integrated even when the spherical slurry droplets contacted each other. After the above operation, the liquid paraffin layer of the molding liquid was replaced with a 1% calcium chloride aqueous solution, and the gelled spherical slurry was solidified and fixed to obtain wet α-TCP precision spheres.

Comparative Example 1
The slurry prepared in Examples 1 and 2 was dropped into only the coagulation liquid to try to produce spherical particles. As a result, the flatness at the time of landing of the dripping slurry and deformation (formation of horns) at the time of sedimentation could not be avoided, and the resulting particles were in the shape of a meteorite or teardrop. Moreover, the mixing of the splash which is made at the time of slurry dripping is unavoidable, and it was necessary to remove them after dripping. In order to solve the problem of this method, the slurry discharge nozzle was placed in the coagulating liquid and an attempt was made to discharge the slurry. However, due to the solidification of the slurry in the nozzle, the nozzle was clogged.

Comparative Example 2
The slurry prepared in Examples 1 and 2 was made into a spherical gel only with the molding liquid. As a result, stacking in the container and damage during recovery were serious, and precise spherical particles could not be obtained.

  As described in detail above, the present invention is a slurry that is molded into a precise spherical shape by quantitatively discharging the slurry into a stationary molding solution, and the slurry that has become spherical in the liquid is not deformed. The present invention relates to a method for manufacturing a ceramic precision sphere comprising solidifying in a coagulating liquid, and an apparatus thereof. According to the present invention, ceramic raw material slurry is dispensed and dispensed into a molding liquid that is not mixed with the slurry. Thus, it is possible to produce ceramic precision spheres in which the capacities of the obtained spherical particles are accurately aligned. Precision spherical ceramic particles that maintain the spherical shape of slurry in the molding liquid are formed, retained, fixed, and solidified in a multi-stage reaction system using the surface tension produced by the slurry in the liquid. A sphere can be produced.

  In the present invention, the slurry can be quantitatively discharged and dispensed into a molding liquid of a stationary molding liquid layer-coagulation liquid layer, and injection molding limited to a spherical shape can be performed. There is an advantage that expensive molds such as injection molding and materials that are wasted as runners are not required. The present invention provides a method and apparatus for manufacturing a ceramic precision sphere that can be suitably used as a means for manufacturing ceramic precision spheres with uniform shapes easily, with reduced raw materials, and with a low budget. Useful.

The schematic diagram of the falling droplet method is shown. The schematic diagram of the cutting polishing method is shown. The schematic diagram of an emulsion method is shown. The schematic diagram of the hydrocast of this invention is shown. The wet alpha-TCP precision sphere shape | molded by the precision sphere shape is shown. The alpha-TCP precision sphere of the dry state shape | molded by the precision sphere shape is shown. Fig. 2 shows a wet HA precision sphere molded into a precision sphere shape. The HA precision sphere of the dry state shape | molded by the precision sphere shape is shown. Fig. 3 shows a wet α-TCP precision sphere formed into a precision sphere shape manufactured by an air pulse dispenser and a desktop robot.

Claims (11)

A method for producing a precision ceramic sphere of precise or uniform grain size or a precursor thereof,
1) An aqueous slurry containing a ceramic raw material, a gelling agent, and a coagulant that coagulates in a coagulating liquid is prepared, and the slurry is placed in a molding liquid of a multistage reaction system of a standing molding liquid-coagulating liquid. By dispensing and dispensing in a constant amount, it is formed into a spherical shape of a precise spherical shape left to the surface tension in the molding liquid, and the spherical shape slurry is gelled simultaneously, thereby producing a precise spherical shape. A shape retaining process, and
2) A step of fixing a precise spherical shape by immersing the retained spherical slurry gel in the coagulating liquid of the above reaction system to form a precise sphere,
Consists of
In extent on climate, be prepared and the ceramic raw material, agarose, gelatin, pectin, or a gelling agent consisting of a surfactant or mixtures thereof, an aqueous slurry containing a coagulant consisting of sodium alginate, the molding solution A method for producing ceramic precision spheres, characterized in that mineral oil, vegetable oil, synthetic oil, liquid paraffin, or collagen aqueous solution is used, and a polyvalent metal ion aqueous solution is used as the coagulating liquid .   As the molding liquid-coagulation liquid multistage reaction system, a multilayered molding liquid formed in the same container in a layered form-a multistage reaction system consisting of coagulation liquid, and the slurry is allowed to stand still- By dispensing and dispensing quantitatively into the upper forming liquid of the multistage reaction system of the coagulating liquid, it is formed into a precise spherical shape depending on the surface tension in the forming liquid, and the formed spherical slurry is simultaneously By accurately gelling, the precise spherical shape is retained, and then the retained spherical slurry gel is allowed to settle and immersed in the coagulating liquid of the reaction system, thereby fixing the precise spherical shape, The manufacturing method of the ceramic precision sphere of Claim 1 made into a precision sphere.   The method for producing a ceramic precision sphere according to claim 1 or 2, wherein the ceramic raw material is calcium phosphate powder.   Calcium phosphate is selected from the group of hydroxyapatite, carbonate apatite, fluorapatite, chlorapatite, β-TCP, α-TCP, calcium metaphosphate, tetracalcium phosphate, calcium hydrogen phosphate, or calcium hydrogen phosphate dihydrate The method for producing ceramic precision spheres according to claim 3, wherein the ceramic spheres are one kind or a mixture of two or more kinds.   The method for producing ceramic spheres according to any one of claims 1 to 4, wherein the molding liquid is 1) mineral oil, vegetable oil, or synthetic oil, 2) liquid paraffin, or 3) a collagen aqueous solution. .   The manufacturing method of the ceramic precision sphere in any one of Claims 1-5 whose coagulation liquid is polyvalent metal ion aqueous solution.   The method for producing a ceramic precision sphere according to any one of claims 1 to 6, wherein the slurry that is quantitatively discharged into the molding liquid is gelled by a temperature drop.   The method for producing ceramic precision spheres according to any one of claims 1 to 7, wherein the quantitative discharge is performed by an air pulse dispenser, a plunger dispenser, a digital pipette, or a syringe.   A method for producing a ceramic precision sphere, comprising drying, firing, or sintering the ceramic precision sphere of the ceramic precursor obtained by the method according to any one of claims 1 to 8. A ceramic material, agarose, gelatin, pectin, or a gelling agent consisting of a surfactant or mixtures thereof, an aqueous slurry containing a coagulant consisting of sodium alginate to solidify in the solidification solution, allowed to stand molded liquid - A means for dispensing and dispensing a quantity into the reaction liquid of the reaction system of the coagulating liquid means and a slurry that has been dispensed and dispensed into a precise spherical shape that depends on the surface tension and gelled to retain the shape. A coagulating liquid for immersing and fixing a spherical slurry shaped and gelled into a spherical shape of a precise spherical shape, and a first reactor that contains a molding liquid for forming as a molding liquid layer comprising a second reactor containing a coagulating liquid layer, and in the first reactor, as a molding liquid of the molding liquid layer, mineral oils, vegetable oils, synthetic oils, containing liquid paraffin, or collagen solution, Serial Second reactor, as the coagulating liquid of the coagulation liquid layer, ceramic precision ball production apparatus is characterized in that so as to accommodate the polyvalent metal ion solution.   A multistage reaction system consisting of a molding liquid layer of the molding liquid contained in the first reactor and a coagulating liquid layer of the coagulating liquid contained in the second reactor is accommodated in a layer in the same container, and the difference in specific gravity is determined. By forming an upper layer forming liquid-lower layer coagulating liquid by using, a forming liquid layer of the forming liquid accommodated in the first reactor, and a coagulating liquid layer of the coagulating liquid accommodated in the second reactor, The apparatus for producing ceramic precision spheres according to claim 10, wherein the ceramic spheres are formed in a multi-layer shape, and a multi-stage reaction composed of a molding liquid-coagulating liquid having a multi-layer structure is performed in a single-stage reaction apparatus.