JP2012000966A - Method for producing shaped article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for highly accurately and efficiently producing a shaped article having the same shape as that of an object to be reproduced.SOLUTION: The method for producing the shaped article having almost the same shape as that of the object to be restored includes (1) a first process for producing a molding die having an internal space of almost the same shape as that of the object by a powder laminate molding method, (2) a second process for filling a part or all of the internal space with a shaped article material and (3) a third process for taking out the shaped article by dissolving the molding die with liquid having solubility to a molding die material constituting the molding die.

Description

  The present invention relates to a novel manufacturing method of a shaped article.

  In recent years, development and practical application of implant materials have been further promoted in the medical field including plastic surgery, orthopedics, oral surgery / dental, and other regenerative medicine. In these fields, not only is it necessary to treat a disease / injury site with an implant material, but the appearance (aesthetics) of the treatment site after healing is often required. For this reason, the implant material is required to have high reproducibility, and it is also necessary to provide the implant material promptly at an appropriate timing so that an effective treatment can be performed within a predetermined period.

  For example, dentures (artificial teeth) used in the field of oral surgery or dentistry are generally made from a resin composition. As an actual method, a procedure is adopted in which an object having almost the same shape as the missing part of the patient's tooth is reproduced and attached to the patient as an artificial tooth. In this case, after taking the mold with plaster etc. in the missing part, filling the mold with dental material, the molded body is taken out from the mold and further shaped manually to finish the artificial tooth Currently.

  However, in such a method, the body must be stationary until gypsum or the like is cured, which may give a patient a mental or physical burden / pain. In addition, although final finishing is performed manually by a dental technician, a certain level of skill is required to achieve precise finishing. On the other hand, if the finish is incomplete, it may be necessary to remake it by giving the patient a sense of discomfort at the time of wearing. As described above, since the production of the artificial tooth requires time and effort, its price is relatively expensive.

  In this regard, for example, a step of standing a wax pattern comprising a tooth profile having a desired tooth profile and a support for supporting the tooth profile in the mold, and a dental investment in the mold Injecting and leaving one end of the support to embed the other wax pattern in the dental investment material, firing the dental investment material to vaporize the wax pattern, and Forming a dental mold having a cavity having a dental mold, wherein the dental investment material is formed by adding calcium carbonate to a main component composed of hemihydrate gypsum and a heat-resistant material. A method for producing a dental mold is known (Patent Document 1). In addition, a method of manufacturing a mold using a model made of a material that is similarly sublimated or burned by heat has been proposed (Patent Document 2, Patent Document 3, etc.).

  Also, for example, a system for producing at least a portion of a denture, comprising: a three-dimensional scanning device that scans the surface of a denture template; and a computer program that receives data from the scanning device and creates a three-dimensional model of the surface A system is known that includes a readable medium and a manufacturing device that creates at least a portion of the denture from a selected material based on the three-dimensional model (Patent Document 4).

JP2002-87918 JP 5-123343 A JP 2009-516554 A JP 2009-542342 A

  However, in the methods as described in Patent Documents 1 to 3, a wax pattern to be a model must be once produced and a mold must be manufactured using this, and the process becomes relatively complicated. Further, in the process of manufacturing the mold, it is necessary to vaporize (sublimate) the wax pattern, and in this respect, it can be said that there is a problem in the working environment.

  In addition, as in Patent Document 4, the method of directly producing a denture using a rapid prototyping machine has limitations on the types of materials that can be applied to the rapid prototyping machine, so the appearance and physical properties of the denture that can be produced are limited. There is a problem that it will be.

  Therefore, a main object of the present invention is to provide a method for manufacturing a shaped object having the same shape as the object to be reproduced with high accuracy and efficiency without being restricted by materials that can be used.

  As a result of intensive studies in view of the problems of the prior art, the present inventor employs a manufacturing method including a step of forming using a specific mold, and further combines a plurality of specific steps. It has been found that the above object can be achieved by forming a structure, and the present invention has been completed.

That is, this invention concerns on the manufacturing method of the following molded article.
1. A method of manufacturing a shaped object having substantially the same shape as the object to be restored,
(1) a first step of producing a molding die having an internal space of substantially the same shape as the object by a powder additive manufacturing method;
(2) a second step of filling a molding material in part or all of the internal space;
(3) A method for manufacturing a shaped article, including a third step of taking out the shaped article by dissolving the mold using a liquid that is soluble in the molding material constituting the mold.
2. Item 2. The manufacturing method according to Item 1, further comprising a step of loading a modeled object having a size smaller than the modeled object into the internal space after the first step, before the second step and / or after the second step.
3. Item 3. The manufacturing method according to Item 2, wherein the modeled object having a small size is manufactured using a mold manufactured by a powder additive manufacturing method.
4). Item 3. The manufacturing method according to Item 2, wherein the modeled object having a small size includes a core member and one or more surface layers formed on part or all of the surface of the member.
5). The surface layer is prepared by a powder additive manufacturing method, and the core member is loaded into the internal space of the mold having an internal space larger than the core member, and the space in the remaining internal space is filled with the molding material. The manufacturing method of said claim | item 4 formed by doing.
6). Item 2. The method according to Item 1, wherein the mold material constituting the mold includes at least one water-soluble compound and a soluble organic polymer.
7). Item 7. The production method according to Item 6, wherein the water-soluble compound is at least one of an alkali metal salt and an alkaline earth metal salt.
8). As the powder additive manufacturing method in the first step,
(A) After forming a powder layer by flattening the mold material, a spray liquid containing at least one kind of water-miscible organic solvent and water is sprayed on a predetermined region of the powder layer to thereby form powder particles in the spray region A process for increasing the bond strength between the powder particles in the non-spreading region,
(B) After the powder is further spread on the powder layer after spreading to form an upper powder layer, the sprayed liquid is spread over a predetermined region of the upper powder layer, whereby the bonding strength between the powder particles in the spreading region Increasing the bonding strength between the powder particles in the non-spreading region,
(C) The manufacturing method according to Item 1, wherein the step (b) is repeated once or twice or more, and a step of producing a shaped article made of the laminated body in the spray region as the mold is performed.

  According to the manufacturing method of the present invention, since a model is manufactured using a mold manufactured by the powder additive manufacturing method, the shape of the object can be reproduced with high accuracy without selecting the type of the model material. For the reason that a wax pattern production process as in the prior art becomes unnecessary, a shaped article can be produced more efficiently.

  In particular, in the manufacturing method of the present invention, the layer configuration can be controlled with high accuracy by using a molding die manufactured by the powder layered manufacturing method even when manufacturing a molded article having a multilayer structure. For example, as described later in the embodiments, a surface layer (coating layer) having a predetermined thickness can be freely formed in an arbitrary region.

  A shaped article manufactured by such a manufacturing method can be widely used for members, parts, and the like in various fields such as medical, electrical / electronic, chemical, and food. In particular, it can be suitably used as an implant material in a field where high reproducibility is required, for example, in the medical field. More specifically, the shaped article according to the present invention can be suitably used as an implant material such as artificial teeth, dentures such as denture bases, artificial bones, artificial joints, artificial hip joints, and artificial ligaments.

In the manufacturing method of this invention, it is a schematic diagram which shows the process example in the case of manufacturing a molded article using a shaping | molding die. In the manufacturing method of this invention, it is a schematic diagram which shows the process example in the case of manufacturing a molded article using a shaping | molding die. In the manufacturing method of this invention, it is a schematic diagram which shows an example of the method of manufacturing a molded article using a shaping | molding die. It is a figure which shows the example of a process which manufactures the shaping | molding die used with the manufacturing method of this invention with a powder layered modeling method. 3 is a schematic diagram (cross-sectional view) of an object to be reproduced in Example 1. FIG. 2 is a schematic diagram (cross-sectional view) of a final mold used in Example 1. FIG. 3 is a schematic diagram (cross-sectional view) of a first mold used in Example 1. FIG. 3 is a schematic diagram (cross-sectional view) of a second mold used in Example 1. FIG. In Example 1, it is a schematic diagram which shows the state which manufactured the molded article from the 1st shaping | molding die and took out the molded article. In Example 1, it is a schematic diagram which shows the state which charges the primary shaped article by a 1st shaping | molding die to a 2nd shaping | molding die, and manufactures a secondary shaped article. In Example 1, it is a schematic diagram which shows the state which charges the secondary molded article by a 2nd shaping | molding die to a final shaping | molding die, and manufactures a final molded article. It is a figure which shows the example of installation of the injection | pouring path | route of modeling material material in a part of shaping | molding die.

The method for producing a shaped article of the present invention is a method for producing a shaped article having substantially the same shape as the object to be restored,
(1) a first step of producing a molding die having an internal space of substantially the same shape as the object by a powder additive manufacturing method;
(2) a second step of filling a molding material in part or all of the internal space;
(3) The method includes a third step of taking out the shaped article by dissolving the mold using a liquid that is soluble in the mold material constituting the mold.

  In the present invention, a shaped object having substantially the same shape as the object to be restored (reproduced) is manufactured. The shaped object in this case only needs to have at least substantially the same outer shape as the outer shape of the object, and the center part of the shaped object may be a hollow (hollow), or the central part is not hollow and is all It may be filled. Hereinafter, the first to third steps will be described in order.

<First step>
In a 1st process, the shaping | molding die which has an internal space of substantially the same shape as a target object is produced by the powder lamination modeling method. For example, as shown to Fig.1 (a), the shaping | molding die 1 which has the internal space 2 of the substantially same shape as a target object is manufactured.

Molding In the present invention, the internal space (molding space) in the molding die (final molding die or the like) may have substantially the same shape (outer shape, contour) as the object to be reproduced. The internal space may be a closed space as shown in FIG. 1 (a), or an open system space having an opening partly as shown in FIGS. It may be. Furthermore, as shown in FIG. 12, in addition to a space having the same shape as the object, a space including the injection passage 8 for the molding material may be used. Further, the mold may be an integral mold or a mold divided into a plurality of molds.

  In the manufacturing method of the present invention, the object may be a real object that actually exists, or a three-dimensional model created by computer graphics or the like.

Mold production (required process)
A known method may be adopted as the powder additive manufacturing method itself for forming the mold. Moreover, the powder additive manufacturing method can also be implemented using a well-known or commercially available apparatus.

  In powder additive manufacturing, for example, data that is reversed on a computer (reversed data) from three-dimensional data created by CAD (Computer Aided Design) of an object is first produced, and the data of the mold is used using the reversed data. (Mold data) can be created. The method for acquiring the three-dimensional data of the object is not particularly limited, and may be appropriately selected according to the material of the object from a known or commercially available device such as a CT scanner.

  Next, the mold data is sliced to a desired thickness and converted into a plurality of cross-section data. First, the powder spread on a plane by a three-dimensional printer having nozzles based on the cross-section data of the bottom (lowermost part) By sequentially performing the steps of spraying the layers and spraying the spray liquid on the upper powder layer based on the cross-sectional data of the upper layer of the bottom, a molding die composed of a laminate of powder layers can be obtained.

More specifically, a method of laminating a powder layer by the following steps can be suitably employed. Ie;
(A) After spreading powder (molding mold material) on a plane to form a powder layer, a spraying region containing a water-miscible organic solvent and at least one kind of water is sprayed on a predetermined region of the powder layer. A step of increasing the bonding strength between the powder particles of the powder to be higher than the bonding strength between the powder particles in the non-spreading region,
(B) After the powder is further spread on the powder layer after spreading to form an upper powder layer, the sprayed liquid is spread over a predetermined region of the upper powder layer, whereby the bonding strength between the powder particles in the spreading region Increasing the bonding strength between the powder particles in the non-spreading region,
(C) The process of producing the modeling object which consists of a laminated body of the said spreading | diffusion area | region as the said shaping | molding die by repeating the process of said (b) once or twice or more,
The method including can be used suitably. The shaped article formed in this way can be manufactured as the mold of the present invention.

  In the above method, when the powder (molding material) is developed on a plane, it may be developed on a member having a flat portion such as a table or a flat plate. The material of the member is not limited as long as the powder does not adhere thereto, and for example, a metal member, a ceramic member, a plastic member, or the like can be used as appropriate.

  Moreover, the thickness of the powder layer in the case of forming a powder layer (upper powder layer) by planar development can be appropriately adjusted. In general, it may be about 50 to 200 μm per layer, preferably 100 to 200 μm.

  Although it does not specifically limit as a kind of the said powder (molding mold material), The powder containing at least 1 sort (s) of a water-soluble compound and a soluble organic polymer can be used suitably. For example, a powder composed of particles containing at least one water-soluble compound and a mixed powder containing a soluble organic polymer powder can be used.

  The water-soluble compound is not particularly limited, but at least one of an alkali metal salt and an alkaline earth metal salt is particularly preferable. Examples of the alkali metal salt include halogenated alkali metal salts such as sodium chloride, potassium chloride, sodium iodide and sodium bromide, and organic acid salts such as sodium acetate. Examples of the alkaline earth metal salt include halogenated alkaline earth metal salts such as calcium chloride and magnesium chloride; sulfates such as magnesium sulfate.

  In addition, as an optional component, as an anti-caking agent for water-soluble compounds, for example, in addition to calcium salt of phosphoric acid, calcium salt of silicic acid, oxides such as silica, alumina, zirconia, etc., if necessary, the powder (molded) It can also be added to the mold material. These anti-caking agents may be appropriately used in powder form.

  What is necessary is just to select suitably as a soluble organic polymer according to the kind etc. of the water-soluble compound to be used. For example, polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, cellulose derivatives (methyl cellulose, ethyl cellulose, ethyl hydroxymethyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose), arabic gum, gelatin, starch, wheat flour and the like can be mentioned. Among these, in the present invention, it is preferable to use a water-soluble organic polymer such as polyvinyl pyrrolidone and polyvinyl alcohol.

  The average particle size of these powders is not particularly limited, but if the particle size is too large, the irregularities on the surface of the mold will increase and the accuracy of the mold will decrease, while if the particle size is too small, the powder will be scattered and dispersed during the development of the powder. In order to easily cause clogging of the liquid spray nozzle, it is usually preferably 350 μm or less, particularly preferably 10 to 150 μm. Therefore, for example, a powder having an average particle size of 20 to 30 μm can also be suitably used. By adopting an average particle diameter within the above range, a mold can be produced with higher accuracy.

  Any spraying liquid may be used as long as it contains at least one water-miscible organic solvent and water. Examples of water-miscible organic solvents include lower alcohols (ethanol, methanol, propanol, etc.), ketones (acetone, methyl ethyl ketone, methyl propyl ketone, isopropyl methyl ketone, etc.), alkyl acetates (methyl acetate, ethyl acetate, etc.), and the like. It is done. A solution in which a water-soluble compound is dissolved in these liquids can also be used. As the water-soluble compound, those similar to those used for the powder (molding material) can be used. In particular, it is preferable to use a water-soluble compound having an effect of increasing the adhesive strength of the powder (molding material) by a synergistic action with the powder (molding material). The concentration in this case is not limited, and in general, the concentration of the water-soluble compound can be appropriately set with the solubility at a predetermined temperature (saturated solubility) in a water-miscible organic solvent or water as the upper limit.

Mold production (optional process)
Further, as an optional step, in the production method of the present invention, in particular, when an alkali metal salt and / or an alkaline earth metal salt is contained in the mold, in addition to the steps (a) to (c) described above, as necessary Any of the following steps (arbitrary steps) may be performed. More specifically, the "step (d)", "steps (d) and (e)", "steps (d) and (f)" or "step (d)" is applied to the mold obtained above. (E) and (f) "can be performed. By carrying out these optional steps, it is possible to obtain effects such as further improving the hardness of the mold.

(D) Water and water miscibility with the second inorganic salt comprising an alkali metal salt and / or alkaline earth metal salt having a lower melting point than the alkali metal salt and / or alkaline earth metal salt contained in the mold. Step (e) of applying a treatment composition containing at least one liquid of an organic solvent to the surface of the mold (e) After the treatment (d), the temperature is equal to or higher than the temperature at which the second inorganic salt melts, and the mixed powder Heat treatment at a temperature at which either one of the alkali metal salt and alkaline earth metal salt contained therein does not melt, or the alkali metal salt and / or alkaline earth metal salt contained in the mold does not melt, Step (f) of heat-treating at a temperature at which the second inorganic salt is melted After applying a liquid containing at least one selected from a thickener and a layered silicate to the surface of the mold, the thickener or layer Heat treatment at a temperature at which the silicate is not decomposed

  Examples of the alkali metal salt used as the second inorganic salt in the step (e) include alkali metal halide salts such as potassium chloride, sodium iodide and sodium bromide. Examples of alkaline earth metal salts include halogenated alkaline earth metal salts such as calcium chloride and magnesium chloride, and sulfates such as calcium sulfate and magnesium sulfate.

  The concentration in the case of using the second inorganic salt mixed with at least one of water and a water-miscible organic solvent is not particularly limited, and can be appropriately set with the solubility (saturated solubility) of the second inorganic salt as an upper limit. . As the water-miscible organic solvent, the same solvents as those exemplified as the spraying liquid can be used.

  A method for applying the treatment composition to the surface of the mold is not limited. For example, a method such as spraying, coating, or dipping can be appropriately employed.

  In the step (f), a liquid containing at least one selected from a thickener and a layered silicate is used, and the same solvent as in the step (e) can be used. In addition, as a method of applying the liquid, for example, a method such as spraying, coating, or dipping can be appropriately employed.

  Examples of thickeners include seed-derived polysaccharides such as guar gum, tara gum, locust bean gum, tamarind seed gum and psyllium seed gum; polysaccharides derived from resins such as gum arabic and karaya gum; and seaweeds such as agar, carrageenan and curdlan Examples include polysaccharides; microorganism-derived polysaccharides such as xanthan gum, gellan gum, and curdlan; plant-derived polysaccharides such as pectin and cellulose; and shell-derived polysaccharides such as chitin and chitosan. In addition, for example, welan gum, sesbania gum, arabinogalactan, erwinia honey ensis gum, tara gum, aloe vera extract, elemi resin, dalman resin, gadhi gum, enterobacter gum, dextran, tragacanth gum, far celerin, pullulan, aeromonas gum, agro Examples thereof include bacterial succinoglucan, enterobacter shimanas gum, oligoglucosamine, cassia gum, and glucosamine.

  As the layered silicate, 2: 1 type layered silicate includes pyrophyllite-talc group (pyrophyllite, talc), smectite group (montmorillonite, beidellite, saponite, hectorite, soconite), vermiculite group (2 Examples include octahedral vermiculite, 3 octahedral vermiculite), and the like.

  Further, in the steps (e) and (f), the treatment may be performed at a temperature that can increase the hardness of the mold, and may be appropriately determined according to the material of the mold, the type of the treatment composition, and the like.

Embodiment of Powder Laminate Modeling Method Hereinafter, in the present invention, an example of a method for producing a mold by the powder layered molding method will be described more specifically with reference to the drawings.

  First, as shown in FIG. 4A, after a powder (molding material) is planarly developed on a table 40 to form a powder layer L1, the powder layer L1 has a nozzle based on cross-sectional data. A spray liquid containing at least one water-miscible organic solvent and water is printed (sprayed) by a three-dimensional printer (not shown). At this time, the bond strength between the powder particles present in the spray region 41a of the powder layer L1 is higher than the bond strength between the powder particles present in the non-spray region 41b.

  Next, as shown in FIG. 4B, the powder (molding material) is further spread on the powder layer L1 after the dispersion to form the upper powder layer L2, and then the developed upper powder layer L2 is formed. The spray liquid is printed (sprayed) by a three-dimensional printer having nozzles based on the cross-sectional data described above (cross-section data one (one layer) above the bottom). At this time, the bond strength between the powder particles present in the spray region 42a of the upper powder layer L2 is higher than the bond strength between the powder particles present in the non-spray region 42b. At the same time, the spray area 42a is joined with the spray area 41a below it.

  Similarly, as shown in FIG. 4C, the formation of the powder layer L3 and the formation of the spray region by application of the spray liquid are repeated, and the powder layer L6 is laminated to the uppermost part. As a result of such layered modeling, a layered modeled object 44 shaped in a spray region by multiple spraying is obtained as shown in FIG.

  Next, as shown in FIG. 4 (e), by removing the powder from the layered portion 46 in the non-spreading region inside the layered object 44, it can be recovered as a mold 45 having an internal space. When the laminated portion 46 of the non-spreading region exists in a closed compartment as shown in FIG. 4E, for example, 1) Two or more molds are used so that the powder inside the laminated model can be removed. A method of dividing, 2) a method of forming one or more extraction passages in the mold so that the powder inside the layered object can be removed, and the like can be adopted. On the other hand, when the laminated portion 46 is present in the opened compartment, the powder may be removed from the opening.

  The obtained mold may be dried at a temperature at which the soluble organic polymer is formed (cured), for example, at a temperature of 200 ° C. or less, before or after the above-described die cutting, if necessary. In addition, the mold is heat-treated within a temperature range that is at or above the temperature at which the soluble organic polymer component burns out as necessary, and the inorganic component does not melt, or is performed in the step (e) or (f). It is also possible to perform heat treatment under the temperature conditions. The heat treatment atmosphere in this case may be any of air, an oxidizing atmosphere, an inert gas atmosphere, a vacuum, and the like, and may be appropriately determined according to the type of inorganic component.

<Second step>
In the second step, a part of or the entire internal space of the mold is filled with a molded article material. For example, as shown in FIG. 1B, a modeled object can be formed by filling the entire internal space 2 in the mold 1 with a modeled material 3.

  In addition, when the internal space 2 is a closed space as shown in FIG. 1A, for example, 1) a method of dividing a mold into two or more so that a molded article material can be filled in the internal space; ) A method of forming one or more shaped article material injection passages in the mold so that the shaped article material can be filled in the internal space can be adopted. On the other hand, when the internal space 2 is open, the shaped article material may be filled from the opening.

In the all-filling second step, for example, as shown in FIG. 1B, the entire internal space can be filled with the molded article material. In this case, a modeled object having a single (single layer) structure can be manufactured.

  Further, after the second process (and before the third process), a modeled object (primary modeled object) smaller in size than the modeled object may be loaded into the internal space. That is, for example, after all of the internal space is filled with the modeling material (after the second step), the primary modeling object having a size smaller than that of the modeling object is inserted into the internal space filled with the modeling material. A surface layer made of the shaped article material can be formed on a part or the whole of the shaped article surface. In this case, the surplus shaped article material protrudes out of the internal space, so it may be removed. The primary modeled object having a smaller size than the modeled object is not particularly limited, and for example, the same core member or multi-layered model used in the case of “partial filling” described later can be used. Therefore, for example, a molded body comprising a core member constituting the central portion and at least one surface layer formed on a part or all of the member surface can be used.

Part filling Further , in the second step, a step of forming a shaped article by filling a part of the internal space of the mold with a shaped article material can be performed. The case where a part of the internal space is filled with the modeling material is not particularly limited as long as a part or the whole of the outer shape of the object can be reproduced. For example, 1) As shown in FIGS. 2A to 2D, before the second step, the primary shaped object 4 having a size larger than that of the shaped object is loaded in the internal space 2 in advance, and the remaining space in the internal space 5) a method of filling the modeling material 6 into 2; 2) a method of filling only the inner surface of the internal space with the modeling material 3 so that the cavity 7 is formed as shown in FIG. And a method of charging a primary shaped object having a smaller size than the shaped object after filling a part of the shaped object material.

  As shown in FIG. 2D, a shaped article having a multilayer structure can be manufactured by the method 1). In the method 2), a molded article having a hollow portion can be manufactured, and a molded article having a multilayer structure can be obtained by filling the hollow portion with a molded article material. In the case of 3), a molded article having a multilayer structure can be produced in the same manner as in the method of 1). In 3) above, the surplus shaped material may protrude outside the internal space, but as with the case described above, the protruding portion may be removed.

  In the method 1) or 3), a primary model having a size smaller than that of the model is used. The primary model may be obtained by any molding method. For example, any of an extrusion molding method, an injection molding method, a powder layered molding method, and the like can be employed. In particular, in the present invention, the powder additive manufacturing method can be suitably used in that a precise model can be efficiently manufactured using desired three-dimensional data.

  Further, the primary shaped article may be a multilayer shaped article comprising a core member constituting the central portion and at least one surface layer formed on a part or all of the member surface. The core member may be manufactured by any molding method. The formation of the surface layer is not particularly limited, and for example, a method using a molding die (mold) can be employed in addition to a spray method, a dipping method, or the like. For example, adopting a step of using a molding die having an internal space larger than the core member, charging the internal space of the molding die, and filling the void in the remaining internal space with the molding material for the surface layer. Thus, a predetermined primary shaped object can be obtained. Moreover, two or more surface layers can be formed by repeating the above steps twice or more. Although it does not specifically limit as a shaping | molding die in this case, For example, the shaping | molding die shape | molded by the powder lamination molding method can also be used. Thereby, the layer configuration can be controlled more precisely.

  The method 2) is not limited as long as it can be carried out so that a layer structure of a model material is formed on the inner surface of the internal space. For example, as described in 1) above, a primary shaped object is loaded in advance, and the remaining space in the internal space is filled with a shaped material, and then the primary shaped object is removed to produce a shaped object having a cavity. it can. In this case, the primary shaped article functions as a so-called formwork. For such a function as a mold, for example, a primary structure formed of a material that can be removed by a liquid (solvent or solution) or the like may be used. For example, if a primary model produced by a powder additive manufacturing method using a powder containing a water-soluble compound and a soluble organic polymer is used as a mold, it can be dissolved in water or an aqueous solution, so that primary modeling is easy. Things can be removed. That is, as a result of forming the cavity after removing the primary modeled object as the mold, a modeled object having the cavity can be obtained. Furthermore, after a shaped object having a cavity is manufactured, a shaped object having a multilayer structure can be obtained by further filling the shaped material with the cavity or inserting a core member.

  In the present invention, when a shaped article having a multilayer structure is manufactured, the formation region, thickness, and the like of each layer can be set as appropriate. The formation place of each layer may be the whole shaped article, or may be a predetermined part. In addition, the thicknesses of the respective layers may be the same thickness or different thicknesses. Furthermore, the thickness of each layer can be controlled uniformly, and for example, a gradient, unevenness, etc. can be given. The thickness of each layer can be controlled, for example, within a range of 5 mm or less, but is not limited to that range.

  In the above methods 1) to 3), when the primary shaped object or the core member is loaded in the inner space of the forming die, as a positioning method, for example, the primary shaped object or the core member is formed using a CT scanner or the like. Known methods such as a method of aligning the center (axis) with the mold and a method of presetting the loading depth can be employed. Moreover, after positioning, what is necessary is just to fix a primary molded article or a core member to a predetermined position using support bodies, such as a pin, a wire, an adhesive tape, a foundation.

Modeling in the Mold In the manufacturing method of the present invention, a predetermined model is produced from the model material filled in the mold. The modeling method (curing method) of a modeled object can be appropriately selected according to the type of modeled material used. For example, when using a resin-based material as a molded article material, usually a monomer, oligomer, polymer, polymerization initiator, polymerization accelerator, and filler as necessary are kneaded (mixed) in advance, and the kneaded (mixed) product It is also possible to obtain a shaped article by filling the mold with a mold and causing a polymerization reaction in the mold.

  On the other hand, when a resin (polymer) material is filled in a mold, the resin material is heated, or the resin material is dissolved or dispersed in a solvent that does not dissolve the mold. Alternatively, the mold may be filled and cured by cooling or evaporating the solvent. In the case where a thermoplastic resin is used, it is preferable that the mold is filled with the thermoplastic resin, then heated to give a temporary viscosity in the mold and then cured.

  In addition, when using an inorganic material as a molding material, molding is performed by filling the mold with the inorganic material and then performing heat treatment to bond the inorganic materials together or by dissolving or dispersing the inorganic material in a solvent that does not dissolve the mold. After filling the mold, the solvent can be volatilized to obtain a shaped article.

Shaped material and core member The material of the shaped material or core member used in the production method of the present invention is not particularly limited. For example, an organic material, an inorganic material, One type or two or more types can be appropriately selected from various materials such as metal materials. For example, when a shaped article is used as an implant material (that belongs to “medical equipment” referred to in the Japanese Pharmaceutical Affairs Law), the following materials can be preferably used. For example, polymer materials such as MMA (methyl methacrylate), EDMA (ethylene glycol dimethacrylate), TMM (tetramethylol methane methacrylate), MEPP (2, 2) that are cured by normal temperature, heating, and photopolymerization reaction. -Bis (4methacryloxypolyethoxy) phenylpropane, UDMA (urethane dimethacrylate), Bis-GMA (2,2-bis (4- (2-hydroxy-3methacryloyloxypropyloxy) phenyl) propane and TEGDMA (Triethylene glycol dimethacrylate), polycarbonate resin, polysulfone resin, polyethylene resin, polyester resin, polypropylene resin, natural polymer (cellulose, chitosan, etc.), etc. Further, these resins (resins, etc.) can be used. Filler (aluminum oxide, Silicon oxide, zirconium oxide, titanium oxide, calcium phosphate-based compound, calcium sulfate, calcium carbonate-based compounds, calcium aluminate-based compounds, amino silicate compounds, silicon carbide, _{carbon, SiO 2 -Na 2 O-CaO} -P 2 O 5 Compounds, SiO ₂ -CaO-Na ₂ OP ₂ O ₅ -K ₂ O-MgO compounds, CaO-P ₂ O ₅ -SiO ₂ -Al ₂ O ₃ compounds, SiO ₂ -B ₂ O ₃ -Al ₂ A composite resin in which an O ₃ —MgO—K ₂ OF compound, a SiO ₂ —CaO—MgO—P ₂ O ₅ compound, a CaO—P ₂ O ₅ compound, etc.) is also used.

Examples of inorganic materials include hydroxyapatite, alumina, zirconia, feldspar, quartz, silicon dioxide, titanium oxide, calcium phosphate compounds, calcium sulfate, calcium carbonate compounds, calcium aluminate compounds, aminosilicate compounds, silicon carbide. , Carbon, SiO ₂ -Na ₂ O-CaO-P ₂ O ₅ series compound, SiO ₂ -CaO-Na ₂ OP ₂ O ₅ -K ₂ O-MgO series compound, CaO-P ₂ O ₅ -SiO ₂ -Al ₂ O ₃ compounds, SiO ₂ -B ₂ O ₃ -Al ₂ O ₃ -MgO-K ₂ OF compounds, SiO ₂ -CaO-MgO-P ₂ O ₅ compounds, CaO-P ₂ O ₅ compounds, etc. Can be used.

  Moreover, in the molded object (or core member) with which internal space is filled beforehand, a metal molded object can also be used besides the above materials. The metal formed body may be either a melted material or a sintered body. What is necessary is just to select suitably as a kind of metal according to the use of a molded article, a use aspect, etc. For example, gold, silver, iron, copper, titanium, steel, stainless steel, a titanium alloy, a cobalt-chromium alloy, a cobalt-chromium-molybdenum alloy, and the like can be given.

Third Step In the third step, the shaped article is taken out by dissolving the mold using a liquid that is soluble in the mold material constituting the mold. For example, as shown in FIG. 1 (c), by removing the material constituting the mold by dissolving the mold 2 of FIG. 1 (b) with a liquid, it is possible to recover the modeled object therein. it can.

  The method of dissolving with a liquid is not limited. For example, any of a method of spraying a liquid on a mold and a method of immersing the mold in a liquid may be used. Moreover, what is necessary is just to make it melt | dissolve to such an extent that a molded article can be collect | recovered at a 3rd process. Therefore, what is necessary is just to melt | dissolve a part or all of a shaping | molding die. That is, all the molds may be dissolved, but it is not always necessary to completely dissolve the molded object as long as the modeled object can be recovered, and only a part may be dissolved. Further, in order to promote dissolution of the mold, the liquid may be used after being appropriately heated.

  The liquid may be soluble in the main powder component (molding material) constituting the mold. More specifically, a liquid that is soluble in the powder constituting the mold and hardly soluble or insoluble in the molded article can be suitably used. As described above, at least one kind of water-miscible organic solvent and water can be suitably used. For example, when the molded article is made of a water-insoluble resin-containing composition and the main powder component (for example, 50% by weight or more, particularly 70% by weight or more) constituting the mold is sodium chloride, water is used as the soluble liquid. Can be suitably used. That is, since the mold can be removed with water, the molded article can be taken out without being deformed or collapsed. And since what melt | dissolved the shaping | molding die with water becomes salt solution, it is advantageous at the point that the concern of a wastewater problem does not arise.

  The features of the present invention will be described more specifically with reference to examples. However, the scope of the present invention is not limited to the examples.

Example 1
A denture having two surface layers was produced by the production method of the present invention.
As an object to be restored, as shown in FIG. 5, the model denture and the base on which the model denture is fixed are integrated on the premise that the model denture is cut off from the base after completion. Three-dimensional data of the object is obtained by a CT scanner, and based on the data, as shown in FIG. 6, a mold (final mold) having an internal space of almost the same shape as the object is obtained by a commercially available powder stack. It produced using the modeling apparatus. As the mold material, powder prepared by spray drying was used. As the composition of this powder, one containing 2% by weight of calcium phosphate as an anti-caking agent with respect to 100% by weight in total of 80% by weight of sodium chloride, 5% by weight of polyvinylpyrrolidone and 15% by weight of magnesium sulfate was used. As the spray liquid, a dye ink containing 5% by weight of glycerin was used.

  Separately, in order to produce two molds having an internal space smaller than the internal space of the mold, the three-dimensional data was processed on a computer to produce three-dimensional data of the two molds. Based on the respective data, two molds were produced by the same powder additive manufacturing method. As shown in FIG. 7, the first mold is a mold for producing a core member. As shown in FIG. 8, the second mold is a mold that has an inner space that is larger than the core member and smaller than the object. Therefore, the size of the internal space of each mold is in the order of the first mold, the second mold, and the final mold from the smallest. The relationship between the sizes of the internal spaces was adjusted so that the thickness of the surface layer formed by these molds was in the range of about 1 to 2 mm.

  A denture having a multilayer structure was prepared using each mold thus obtained. First, as shown in FIG. 9, the entire interior space of the first mold was filled with a dental resin (product name “Repezian” manufactured by GC Corporation) and then cured. Next, the primary molding (core member) was taken out by dissolving the first mold with water.

  Thereafter, the primary shaped product obtained as the core member was loaded into the second mold. In this case, the base layer was fixed using the base while aligning the center (axis) so that the surface layer could be formed in a predetermined region of the core member. Next, the voids in the internal space formed by loading the core member were filled with an adhesive (product name “Repezian” manufactured by GC Corporation). FIG. 10 shows a cross-sectional configuration in this state. The filling of the adhesive was carried out by providing an injection passage (not shown) at an appropriate location of the second mold and performing injection from there. Then, the secondary shaped article was taken out by dissolving the second mold with water.

  Next, the secondary shaped article was loaded into a final mold. Also in this case, the base layer was fixed while aligning the center (axis) so that the surface layer was formed in a predetermined region. Then, as shown in FIG. 11, a dental coating agent (product name “Repezian” manufactured by GC Corporation) was filled in the gap between the secondary shaped product and the internal space of the final mold, and was cured. Filling with the coating agent was carried out by providing an injection passage (not shown) at an appropriate location of the second mold and performing injection from there. Thereafter, the final mold was dissolved in water to take out the intended final model. The obtained final model was a multilayer structure composed of a core member and two surface layers, and had almost the same shape as the object to be reproduced. Then, the base part was cut out from the modeled object by a normal cutting process, and a denture (artificial tooth) as a final target object could be obtained.

Claims (8)

A method of manufacturing a shaped object having substantially the same shape as the object to be restored,
(1) a first step of producing a molding die having an internal space of substantially the same shape as the object by a powder additive manufacturing method;
(2) a second step of filling a molding material in part or all of the internal space;
(3) A method for manufacturing a modeled object, which includes a third step of taking out the modeled object by dissolving the mold using a liquid that is soluble in the powder constituting the mold. The manufacturing method according to claim 1, further comprising a step of loading a modeled object having a size smaller than the modeled object into the internal space after the first step, before the second step and / or after the second step. The manufacturing method of Claim 2 which is manufactured using the shaping | molding die produced by the powder layered modeling method of the said small-sized modeling thing. The manufacturing method according to claim 2, wherein the modeled object having a small size includes a core member and one or more surface layers formed on a part or all of the surface of the member. The surface layer is prepared by a powder additive manufacturing method, and the core member is loaded into the internal space of the mold having an internal space larger than the core member, and the space in the remaining internal space is filled with the molding material. The manufacturing method of Claim 4 formed by doing. The manufacturing method according to claim 1, wherein the mold material constituting the mold includes at least one water-soluble compound and a soluble organic polymer. The production method according to claim 6, wherein the water-soluble compound is at least one of an alkali metal salt and an alkaline earth metal salt. As the powder additive manufacturing method in the first step,
(A) After forming a powder layer by flattening the mold material, a spray liquid containing at least one kind of water-miscible organic solvent and water is sprayed on a predetermined region of the powder layer to thereby form powder particles in the spray region A process for increasing the bond strength between the powder particles in the non-spreading region,
(B) After the powder is further spread on the powder layer after spreading to form an upper powder layer, the sprayed liquid is spread over a predetermined region of the upper powder layer, whereby the bonding strength between the powder particles in the spreading region Increasing the bonding strength between the powder particles in the non-spreading region,
(C) The manufacturing method according to claim 1, wherein the step of (b) is repeated once or twice or more, and a step of producing a shaped article made of the laminated body in the spray region as the mold is performed.