WO2007010598A1

WO2007010598A1 - Process for producing stent and powder sintering apparatus

Info

Publication number: WO2007010598A1
Application number: PCT/JP2005/013266
Authority: WO
Inventors: Kenichi Shimodaira; Chiaki Abe; Akira Shinjo
Original assignee: Homs Engineering Inc.
Priority date: 2005-07-19
Filing date: 2005-07-19
Publication date: 2007-01-25

Abstract

A process for producing a stent, characterized by including the powder sintering step of sequentially repeating the sintered layer forming step of providing a powder layer on a powder sintering table with the use of a powder layer forming unit and subsequently carrying out selective irradiation of the powder layer with energy beams to thereby form a sintered layer and the powder sintering table descending step of moving the powder sintering table downward by a given extent so as to effect of superimposing of sintered layers, thereby producing a structure of desired three-dimensional morphology. This stent producing process enables easy production of a stent with relatively complex morphology.

Description

Specification

Stent manufacturing method and powder sintering apparatus

Technical field

The present invention relates to a method for manufacturing a stent and a powder sintering apparatus.

Background art

FIG. 22 is a view for explaining a conventional stent manufacturing method. FIG. 22 (a) is a schematic view showing the main part of the laser device 900, and FIG. 22 (b) is an external view of the manufactured stent 940. FIG.

In the conventional stent manufacturing method, as shown in FIG. 22, while the metal tube 930 is rotated or moved in the axial direction by the movable chuck 920 in the laser processing apparatus 900, The laser irradiation apparatus 910 scans the surface of the metal tube 930 with the laser beam L, and processes the surface of the metal tube 930 into a mesh shape, thereby manufacturing the stent 940 (see, for example, Patent Documents 1 and 2). ) ₀

Therefore, according to the conventional stent manufacturing method, if a predetermined metal tube 930 is prepared, a stent 940 having a predetermined mesh shape can be manufactured.

[0004] Patent Document 1: Japanese Patent Laid-Open No. 2005-095610

Patent Document 2: Japanese Patent Laid-Open No. 2001-219286

Disclosure of the invention

Problems to be solved by the invention

[0005] By the way, there is a need to use a stent having a relatively complicated shape at a treatment site using coronary artery interpension (PCI). For example, when a stent is used for a blood vessel that has a shape that gradually decreases in the inner diameter along the axial direction, the shape in which the outer diameter gradually decreases in the axial direction (tapered). There is a need to use a stent having a shape. In addition, when a stent is used at a blood vessel bifurcation, there is a need to use a stent having a bifurcation.

[0006] Further, there is a need to use a stent that can support and support the blood vessel after placement of the stent, which is difficult to damage the blood vessel when the stent is inserted. Meet these needs As the stent, for example, the strut thickness is thicker at the axially central portion (see reference numeral 942 in FIG. 22 (b)), and at both axial end portions (see reference numeral 944 in FIG. 22 (b)). A thinly constructed stent is conceivable.

Thus, there is a need in the field of treatment using PCI that a stent having a relatively complicated shape is used for various reasons.

[0007] However, in the conventional stent manufacturing method, a metal tube is used as a starting material.

Therefore, there is a problem that it is not easy to manufacture a stent having a relatively complicated shape as described above! /, And! /.

[0008] Therefore, the present invention has been made to solve the above-described problems, and provides a method for manufacturing a stent capable of easily manufacturing a stent having a relatively complicated shape. With the goal. Also, a powder sintered calorie device having a relatively complicated shape and suitable for producing a high-purity product such as a stent having such a relatively complicated shape is provided. With the goal.

Means for solving the problem

[0009] (1) In the stent manufacturing method of the present invention, an energy beam is selectively applied to the powder layer after the powder layer is formed on the powder sintered table using the powder layer forming apparatus. The sintered layer is stacked by sequentially repeating a sintered layer forming step of forming a sintered layer by irradiation and a powder sintering processing table lowering step of lowering the powder sintering processing table by a predetermined amount. It includes a powder sintering process for forming a layered structure having a desired three-dimensional shape.

Therefore, according to the stent manufacturing method of the present invention, a structure having a desired three-dimensional shape by laminating a sintered layer formed by selectively irradiating a powder layer with an energy beam. Therefore, it is possible to easily manufacture a stent having a relatively complicated shape. As a result, for example, a stent having a shape (tapered shape) that gradually decreases in outer diameter along the axial direction, a stent having a bifurcated portion, and the thickness of the strut at the central portion in the axial direction. It is possible to easily manufacture a stent having a relatively complicated shape, such as a stent that is thick and thin at both axial ends. [0011] By the way, in the conventional stent manufacturing method, since a metal tube is used as a starting material, V, it is difficult to manufacture a stent having a composition different from the composition of the metal tube.

On the other hand, according to the stent manufacturing method of the present invention, it is possible to manufacture a stent having a desired composition by setting the composition of the powder contained in the powder layer to a desired composition. Become. In this case, a stent having a desired composition distribution can be manufactured by appropriately changing the composition of the powder contained in the powder layer.

[0012] By the way, in the conventional method for manufacturing a stent, since a metal tube is used as a starting material, it is difficult to manufacture a stent having a density different from the density of the metal tube. According to the method for manufacturing a stent of the invention, conditions for powder sintering (for example, what kind of powder is used in the powder layer, what is the energy beam irradiation, etc.) and the structure after the structure is formed According to the heat treatment conditions (for example, whether a strong heat treatment or a weak heat treatment is performed), a stent having a desired density can be manufactured. In this case, the method of irradiation with the energy beam is changed, the heat treatment of the structure is performed unevenly after the structure is formed, or the composition of the powder contained in the powder layer is appropriately changed. This makes it possible to produce a stent having a desired density distribution.

[0013] Further, according to the stent manufacturing method of the present invention, the powder in the portion of the powder layer that has not been subjected to sintering can be reused after collection, so that the yield of the material can be increased. High manufacturing method.

[0014] Examples of the powder include a powder made of austenitic stainless steel (for example, SUS316), a powder having Ni-Ti alloy power, a powder having Co-Cr alloy power, a powder having Au-Cu alloy power, Au — Various metal powders such as powders made of Pt—Pd alloy, and various ceramic powders such as powders made of aluminum oxide and powders made of silicon oxide can be used. In this case, when the ceramic powder is used as the powder, it is preferable to use the force ceramic powder together with the metal powder, which can be used alone. As the powder, a powder having an average particle diameter in the range of 0.05 / ζ πι to 40 / ζ πι should be used. Is preferred.

As the energy beam, a laser beam, an electron beam, or an ion beam that can increase the energy density and can also increase the resolution can be preferably used. As a result, it is possible to form a structure with a relatively short time and high shape accuracy (for example, several m or less). As a result, a structure with a relatively short time and high shape accuracy ( For example, several / zm or less.) Stents can be manufactured. As the energy beam, it is preferable to use an energy beam having a beam diameter of 10 to 70 μm.

[0016] As the powder sintering table, one having a descending pitch in the range of 1 to 40 µm can be preferably used.

[0017] (2) In the stent manufacturing method according to (1) above, it is preferable that the structure is formed in an airtight chamber.

[0018] By the way, since the stent is used in a harsh environment such as being placed in a blood vessel for a long period of time and exposed to pulsation or blood, it is preferable that the stent is a high-purity stent with very little contamination of impurities. . According to the stent manufacturing method of the present invention, by using the method as described above, contamination of impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities from the outside is suppressed, and a high-purity stent is manufactured. It becomes possible.

[0019] In this case, when the energy beam is a laser beam, the powder sintering process is performed in a state where the hermetic chamber is evacuated or an inert gas or a predetermined reducing gas is introduced into the hermetic chamber. It is preferable to do so. On the other hand, when the energy beam is an electron beam or an ion beam, the powder sintering process is preferably performed in a state where the hermetic chamber is evacuated.

[0020] (3) In the stent manufacturing method according to (2) above, the energy beam is a laser beam, and the powder layer is formed from a laser beam irradiation device installed outside the hermetic chamber. It is preferable to irradiate with a laser beam.

[0021] By adopting such a method, it is possible to prevent impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities from being mixed into the hermetic chamber due to the irradiation of the laser beam. A stent can be manufactured. In this case, it is preferable to provide a light-transmitting window made of, for example, quartz glass in the hermetic chamber and irradiate the laser beam through the light-transmitting window.

[0023] It is preferable to use a high-resolution UV laser beam as the laser beam in order to accurately reproduce the mesh pattern as a stent. By doing so, a resolution of several m / zm or less can be easily achieved.

(4) In the stent manufacturing method according to (2) or (3) above, the powder is produced using a powder sintering processing table drive device installed outside the hermetic chamber. It is preferable to raise and lower the sintering table.

[0025] By adopting such a method, it is possible to prevent impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities from entering the hermetic chamber due to the raising and lowering of the powder sintering carriage table. It becomes possible to produce a high-purity stent.

In this case, it is preferable to raise and lower the powder sintering processing table using a magnet or a linear motor.

[0027] (5) In the stent manufacturing method according to any one of (2) to (4) above, the powder layer forming apparatus driving device installed outside the hermetic chamber is used. It is preferable to drive the powder layer forming apparatus.

[0028] By adopting such a method, it is possible to prevent impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities from entering the hermetic chamber due to driving of the powder layer forming apparatus. It becomes possible to produce a pure stent.

[0029] In this case, the powder layer forming apparatus is preferably driven using a magnet or a linear motor.

[0030] (6) In the stent manufacturing method according to any one of (2) to (5) above, the structure is heated while being heated using a heating device installed outside the hermetic chamber. It is preferable to form

[0031] By adopting such a method, the temperature difference inside the structure during the formation of the structure can be reduced by forming the structure while heating, so that distortion in the structure can be reduced. Can do. In addition, by heating using a heating device installed outside the hermetic chamber, moisture, oxygen, nitrogen, organic matter, and metal Impurities such as pure substances are prevented from being mixed, and it becomes possible to manufacture a high-purity stent.

[0032] As the heating device, a heater, an infrared heating device, a high-frequency heating device, or the like can be preferably used. Especially, the infrared heating apparatus which can heat the site | part in which the structure is arrange | positioned locally can be used especially preferable. As heating conditions, it is preferable to heat the structure in a range of 60 to 300 ° C.

[0033] (7) In the stent manufacturing method according to any one of (1) to (6) above, it is preferable to form a sintered layer while changing the components of the powder layer.

[0034] In this case, for example, when the sintered layer is formed while changing the components for each layer, the sintered body is integrally formed by heat-treating the structure after the structure is formed. Because it becomes possible to alloy, stents of various compositions can be manufactured. For example, when the sintered layer is formed while gradually changing the components, a stent having a composition distribution in which the composition gradually changes (for example, a gradient alloy) is manufactured. It becomes possible.

In addition, when a sintered layer is formed by changing the components in a stepped manner during the process, a stent having a stepped composition distribution can be manufactured. In this case, for example, a stent which is hard at the center in the axial direction and has high flexibility at both ends in the axial direction, that is, the stent can be supported with force after placement of the stent, which hardly damages the blood vessel when inserting the stent. Possible stents can be manufactured.

[0035] (8) In the stent manufacturing method according to any one of the above (1) to (7), the first method for increasing the sintered density of the structure after the powder sintering step It is preferable to further include a heat treatment step.

[0036] By adopting such a method, the sintered density of the structure can be increased, so that a stent having predetermined physical properties (for example, hardness, flexibility, density, porosity, etc.) is obtained. It can be manufactured.

In this case, when manufacturing a stent having an austenitic stainless steel (for example, SUS316) force, it is preferable to perform heat treatment under conditions of, for example, 800 to L 100 ° C for 30 to 90 minutes. As a result, before the first heat treatment step, the density ratio was 70-80% of the true metal density. Can be made to have a density ratio of 97 to L00% of the true metal density after the first heat treatment step.

[0037] In addition, by adopting the above-described method, for example, when the sintered layer is formed while changing the components for each layer as described above, each sintering is performed by this heat treatment. Because the layers can be alloyed together, stents of various compositions can be manufactured.

In this case, when a stent made of a Co—Cr alloy cover is produced from Co powder and Cr powder, it is preferable to heat-treat under conditions of, for example, 950 to 1250 ° C. and 30 to 90 minutes. In addition, when a stent having Au—Pt—Pd alloy strength is manufactured from Au powder, Pt powder and Pd powder, for example, heat treatment may be performed under the conditions of 880 to 1050 ° C. and 30 to 90 minutes. preferable. Instead of using metal powders with different metal component strengths as powder, alloy powders with different components can be used as powder, and alloy powder and single metal component strength can be used as powder. It is also possible to use a metal powder.

[0038] In addition, by adopting the method as described above, for example, when the sintered layer is formed while gradually changing the components as described above, a composition that gradually changes the composition. It becomes possible to produce a stent having a distribution.

[0039] (9) In the stent manufacturing method according to (8) above, it is preferable that a second heat treatment step for performing a melting treatment of the structure is included after the first heat treatment step.

[0040] By adopting such a method, it is possible to manufacture a stent having a predetermined hardness and elasticity by performing a melt treatment as the second heat treatment.

[0041] As the second heat treatment, for example, when manufacturing a stent having austenitic stainless steel (for example, SUS316) force, rapid cooling is performed after heat treatment at 950 to 1250 ° C for 30 to 90 minutes. It is preferable to perform a heat treatment such as performing. In addition, for example, when manufacturing a stent made of Co—Cr alloy, heat treatment such as rapid cooling after heat treatment at 1100 to 1300 ° C. for 30 to 90 minutes is performed. It is preferable. For example, when a stent having an Au-Pt-Pd alloy strength is manufactured, a heat treatment may be performed in which quenching is performed after heat treatment is performed at 1000 to 1050 ° C. for 30 to 90 minutes. preferable.

[0042] (10) In the stent manufacturing method according to (9) above, after the second heat treatment step, It is preferable that the method further includes a third heat treatment step for performing an age hardening treatment of the structure.

[0043] In the case where the structure is made of a metal material having age-hardening properties, by using such a method, by performing age-hardening treatment as the third heat treatment, the structure has a predetermined hardness' elasticity. A stent can be manufactured.

[0044] As the third heat treatment, for example, when manufacturing a stent having Co—Cr alloy strength, 7

It is preferable to perform the heat treatment at 00 to 850 ° C. for 30 to 180 minutes. For example, Au

— When manufacturing a stent made of a Pt—Pd alloy, it is preferable to perform heat treatment at 800 to 960 ° C. for 30 to 180 minutes.

[0045] In this case, the first heat treatment step and the second heat treatment step can be used together, and the first heat treatment step, the second heat treatment step, and the third heat treatment step can be performed continuously.

[0046] (11) Preferably, the method for manufacturing a stent according to any one of (1) to (10) further includes a surface polishing step of polishing the surface of the structure.

[0047] Incidentally, a structure formed by powder sintering is generally formed in a form in which a large number of powders adhere to the surface. On the other hand, by adopting the method as described above, the powder adhering to the surface can be removed, so that the surface of the stent can be made smooth.

[0048] For the surface polishing step, it is preferable to perform puff polishing, barrel polishing (wet or dry), electrolytic polishing or chemical polishing.

[0049] (12) The stent manufacturing method according to any one of (1) to (11) preferably further includes a drug impregnation step of impregnating the structure with a drug.

[0050] By adopting such a method, it is possible to produce DE S (Drug-Eluting Stent) in which a necessary drug is impregnated inside the pores of the structure.

[0051] In this case, in the first heat treatment step in (8) and the like, by adjusting the sintered density so as to have a predetermined porous degree, the characteristics as DES (for example, chemical agent) Carrier characteristics, drug release characteristics, etc.) can be made desired.

[0052] As the drug, a growth inhibitor, a growth inhibitory and immunosuppressant, an immunosuppressant, an extracellular matrix modifier, an endothelial repair promoter, or a drug appropriately combined with these can be preferably used. [0053] (13) In another stent manufacturing method of the present invention, a powder layer made of a metal powder coated with a resin is formed on a powder solidification table using a powder layer forming apparatus. After that, a powder solidified layer forming step for selectively irradiating the powder layer with an energy beam to melt the resin to form a powder solidified layer, and a powder for lowering the powder solidified table by a predetermined amount It is characterized by including a powder solidifying step of forming a structure having a desired three-dimensional shape by laminating the powder solidified layers by sequentially repeating a solidifying table lowering step.

Therefore, according to another stent manufacturing method of the present invention, a powder solidified layer formed by selectively irradiating a powder layer with an energy beam is laminated to have a desired three-dimensional shape. Since the structure is formed, a stent having a relatively complicated shape can be easily manufactured as in the case of the stent manufacturing method of the present invention. As a result, for example, a stent having a shape (tapered shape) in which the outer diameter gradually decreases along the axial direction (tapered shape), a stent having a bifurcated portion, and the strut thickness at the central portion in the axial direction. It is possible to easily manufacture a stent having a relatively complicated shape such as a stent which is thick and thin at both ends in the axial direction.

[0055] (14) In still another stent manufacturing method of the present invention, the powder layer forming apparatus is used to form a powder layer made of a resin powder and a metal powder on a powder solidifying table. A powder solidified layer forming step for selectively irradiating the powder layer with an energy beam to melt the resin powder to form a powder solidified layer, and a powder solidified table for lowering the powder solidified table by a predetermined amount It is characterized by including a powder solidifying step of forming a structure having a desired three-dimensional shape by laminating the powder solidified layer by sequentially repeating a descending step.

[0056] For this reason, according to still another stent manufacturing method of the present invention, a powder solidified layer formed by selectively irradiating a powder layer with an energy beam is laminated to obtain a desired three-dimensional shape. As in the case of the stent manufacturing method of the present invention and other stent manufacturing methods of the present invention, a stent having a relatively complicated shape is easily manufactured. It becomes possible. As a result, for example, a stent having a shape (tapered shape) in which the outer diameter gradually narrows along the axial direction (tapered shape), a stent having a bifurcated portion, and the strut thickness at the central portion in the axial direction. A stent having a relatively complicated shape, such as a thick stent formed at both ends in the axial direction, is also thin. It can be easily manufactured.

(15) In the stent manufacturing method according to the above (13) or (14), after the powder solidification step, a degreasing step for removing the scab component contained in the structure is performed as necessary. You can also.

In this case, the porosity of the structure can be adjusted.

(16) A powder sintering apparatus of the present invention includes an airtight chamber having a light-transmitting window, a powder sintering processing table disposed inside the airtight chamber and capable of moving up and down, and the air sintering chamber. A powder layer forming device which is disposed inside a closed chamber and forms a powder layer on the powder sintering processing table; and a powder layer forming device which is disposed outside the hermetic chamber and passes through the translucent window. And a laser beam irradiation device for irradiating the layer with a laser beam.

[0060] For this reason, according to the powder sintering apparatus of the present invention, a product having a relatively complicated shape can be manufactured by performing powder sintering, By performing the powder sintering process, it is possible to manufacture high-purity products with less contamination of impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities. Therefore, according to the powder sintering apparatus of the present invention, it is suitable for producing a high-purity product having a relatively complicated shape such as a stent having a relatively complicated shape. A simple powder sintering machine

Note that the powder sintering apparatus of the present invention is not limited to a stent manufacturing method, but has a relatively complicated shape and requires high purity, for example, a custom-made artificial It can be suitably used in methods for producing joints, dental crowns and the like.

[0061] (17) In the powder sintering apparatus according to (15), the laser beam irradiation device is preferably a UV laser beam irradiation device.

[0062] With this configuration, it is possible to perform powder sintering processing (for example, several / zm or less) with high shape accuracy. For this reason, it becomes possible to manufacture a product with relatively high shape accuracy, for example, a stent having a shape with relatively high shape accuracy.

As the UV laser beam irradiation device, an Nd-YAG wavelength conversion (fourth harmonic) laser can be preferably used.

[0063] (18) In the powder sintering apparatus according to (16) or (17), the translucent window Preferably has a curved surface portion.

[0064] With this configuration, the focusing power of the laser beam is increased, and the shape accuracy is high.

V, powder sintering can be performed.

(19) In the powder sintering apparatus according to any one of (16) to (18), the powder layer forming apparatus supplies the powder onto the powder sintering table. It is also preferable that the power of the powder supply device with the function of

[0066] With this configuration, since the powder layer can be formed using the powder as it is, a special pretreatment for forming the powder layer (for example, production of a powder sheet, powder Etc.), and the manufacturing process can be simplified. In addition, since the powder in the powder layer that has not been sintered can be reused after collection.

It becomes possible to increase the material yield.

[0067] (20) In the powder sintering apparatus according to (19), it is preferable that the powder supply apparatus includes a plurality of powder supply apparatuses.

[0068] With this configuration, powders of different components are put in each of the plurality of powder supply devices, and the powder is supplied by any of these powder supply devices. It is possible to manufacture products having various compositions and products having a composition distribution by appropriately controlling the above.

[0069] For example, in the case where the sintered layer is formed while changing the components for each layer, the sintered body is integrally alloyed by heat-treating the structure after the structure is formed. This makes it possible to produce products with various compositions.

In addition, for example, when the sintered layer is formed while gradually changing the components, it is possible to manufacture a product having a composition distribution in which the composition gradually changes (for example, made of a gradient alloy). It becomes possible.

Further, when the sintered layer is formed by changing the components stepwise during the process, a product having a stepwise composition distribution can be manufactured.

[0070] (21) The powder sintering apparatus according to the above (19) or (20) further includes a vibration supply means for applying vibration to the powder on the powder sintering table. preferable.

With this configuration, the powder in the powder supply device or on the powder sintering processing table Therefore, it is possible to form a uniform powder layer with a high powder filling rate on the powder sintering table. As the vibration supply means, an ultrasonic oscillator can be preferably used.

[0072] (22) In the powder sintering apparatus according to any one of (16) to (18), the powder layer forming apparatus uses a powder sheet on which powder is fixed as the powder. It is preferable that one or a plurality of powder sheet supply devices be supplied to the sintering table.

[0073] According to this configuration as well, it is possible to form a uniform powder layer having a high layer thickness with a high powder filling rate on the powder sintering table.

[0074] As the powder sheet supply apparatus, a powder sheet supply apparatus for supplying a powder sheet to a powder sintering processing table by feeding a roll-shaped powder sheet can be preferably used. In this case, after lowering the powder sintering process table, a new powder sheet is supplied onto the powder sintering process table, and then this powder sheet is cut and the powder sintering process table is cut. A powder layer may be formed on the top, but before lowering the powder sintering table, a new powder sheet is supplied onto the powder sintering table and laser beam irradiation is performed as it is. After that, the powder sheet may be cut and the powder sintering table may be lowered. In this case, the powder sheet may be cut with a dedicated cutting device or with a laser beam irradiation device for forming a sintered layer.

[0075] In addition, as the powder sheet supply device, the powder sheet is fed into a powder sintering processing table by feeding out a sheet-like powder sheet that has been calendered according to the shape of the powder sintering processing table. A powder sheet supply device for supplying to the bull can be preferably used.

(23) In the powder sintering apparatus according to any one of (16) to (18), the powder layer forming apparatus supplies a liquid containing powder to the powder sintering processing table. It is also preferable that one or more powder feeders supply to the power.

[0077] With this configuration as well, it is possible to form a uniform powder layer having a high layer thickness on the powder sintering table with a high powder filling rate.

[0078] In this case, it is preferable to form a sintered layer by supplying a liquid containing powder to the powder sintering table and then removing the liquid component and then irradiating with a laser beam.

(24) In the powder sintering cabinet according to any one of (16) to (23), the gas sintering It is preferable to further include a powder sintering table driving device that is disposed outside the closed chamber and moves the powder sintering table up and down.

[0080] With this configuration, it is possible to prevent impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities from entering the hermetic chamber due to the raising and lowering of the powder sintering table. This makes it possible to produce high-purity products.

(25) In the powder sintering cake apparatus according to any one of (16) to (24), the powder is disposed outside the hermetic chamber and drives the powder layer forming apparatus. It is preferable to further include a body layer forming device driving device.

[0082] With this configuration, it is possible to prevent impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities from entering the hermetic chamber due to driving of the powder layer forming apparatus, and to achieve high purity. It is possible to manufacture products.

[0083] (26) The powder sintering cabinet according to any one of (16) to (25), further comprising a heating device that is disposed outside the hermetic chamber and heats the structure. It is preferable.

[0084] With this configuration, by forming the structure while heating, the temperature difference inside the structure during formation of the structure can be reduced, so that distortion in the structure can be reduced. it can. In addition, by heating using a heating device installed outside the hermetic chamber, impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities are mixed into the hermetic chamber due to heating of the structure. This makes it possible to manufacture high-purity products.

[0085] As the heating device, a heater, an infrared heating device, a high-frequency heating device, or the like can be preferably used. Especially, the infrared heating apparatus which can heat the site | part in which the structure is arrange | positioned locally can be used especially preferable.

[0086] (27) In the powder sintering apparatus according to any one of (16) to (26), the powder sintering apparatus is disposed between the powder sintering process table and the translucent window, It is preferable to further include shielding means for shielding the spray of powder from the powder layer and the evaporated substance of the powder.

[0087] With this configuration, it is possible to suppress deterioration of the light transmittance of the light-transmitting window due to the powder droplets from the powder layer and the powder evaporation material adhering to the light-transmitting window. be able to. This makes it possible to always irradiate the laser beam under certain conditions during the formation of the structure. It becomes possible to improve the quality of the product.

(28) In the powder sintering apparatus according to (27), the shielding means is blown against the light-transmitting window and a gas supply device that blows gas onto the light-transmitting window. It is preferable to have a gas suction device for sucking gas.

(29) In the powder sintering apparatus according to (27), the shielding means introduces a gas flow between the powder sintering process table and the translucent window. It is also preferable to have a gas flow supply device and a gas flow absorption device I that absorbs the gas flow from the gas flow supply device.

[0090] (30) In the powder sintering apparatus according to (27), the shielding means is intermittently or continuously between the powder sintering table and the translucent window. It is also preferable to have a transparent film supply device that feeds the transparent film into.

Brief Description of Drawings

FIG. 1 is a flowchart shown for explaining a stent manufacturing method according to Embodiment 1.

FIG. 2 is a flowchart shown for explaining the stent manufacturing method according to the first embodiment.

FIG. 3 is a view for explaining a powder sintering apparatus 100 according to Embodiment 1.

FIG. 4 is a view for explaining a powder sintering table 132 in the powder sintering apparatus 100.

FIG. 5 is a process diagram shown for explaining a powder sintering process (step S200).

FIG. 6 is a perspective view schematically showing the structure 10 during the sintering process.

FIG. 7 is a flowchart for explaining a post-processing step (step S300) in the stent manufacturing method according to the first embodiment.

FIG. 8 is a view for explaining a powder sintering apparatus 100a according to Modification 1.

FIG. 9 is a view for explaining a powder sintering apparatus 100b according to Modification 2.

FIG. 10 is a view for explaining a powder sintering apparatus 100c according to Modification 3.

FIG. 11 is a view for explaining a powder sintering apparatus lOOd according to modification example 4.

FIG. 12 is a view for explaining a powder sintering apparatus 100e according to Modification 5. FIG. 13 is a view for explaining a powder sintering apparatus lOOf according to Modification 6.

FIG. 14 is a view shown for explaining a powder sintering apparatus 100g according to Modification 7.

FIG. 15 is a view for explaining a powder sintering apparatus 100 h according to Modification 8.

FIG. 16 is a view for explaining a powder sintering apparatus 100i according to Modification 9.

FIG. 17 is a view for explaining a powder sintering apparatus 100j according to Modification 10;

FIG. 18 is a flowchart shown for explaining a stent manufacturing method according to the second embodiment.

FIG. 19 is a flowchart shown for explaining the stent manufacturing method according to the third embodiment.

FIG. 20 is a flowchart for explaining the stent manufacturing method according to the fourth embodiment.

FIG. 21 is a view for explaining the structure of the stent 20 manufactured by the stent manufacturing method according to Embodiment 4.

FIG. 22 is a view for explaining a conventional stent manufacturing method.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a stent manufacturing method and a powder sintering apparatus according to the present invention will be described based on the embodiments shown in the drawings.

[0093] [Embodiment 1]

FIG. 1 and FIG. 2 are flowcharts for explaining the stent manufacturing method according to the first embodiment.

As shown in FIG. 1, the stent manufacturing method according to Embodiment 1 includes a powder preparation step (Step S100) for preparing powder used for powder sintering, and a third step by performing powder sintering. A powder sintering process (step S200) for forming a structure having the original structure, and a post-processing process (step S300) for manufacturing the stent by performing a heat treatment or the like of the structure.

As shown in FIG. 2, the powder sintering process (step S200) is a powder layer forming process in which a powder layer is formed on a powder sintering process table using a powder layer forming apparatus ( Step S212), a sintering layer forming step (Step S214) for selectively irradiating the powder layer with an energy beam to form a sintered layer, and a powder sintering for lowering the powder sintering processing table by a predetermined amount. Bonding process And a table lowering process (step S216). Then, by repeating these steps in sequence, a sintered body is laminated to form a structure having a desired three-dimensional shape.

The powder sintering process (step S200) is performed using a dedicated powder sintering apparatus.

FIG. 3 is a view for explaining the powder sintering apparatus 100 according to the first embodiment. Fig. 3 (a) is a plan view of the hermetic chamber 110 in the powder sintering cabinet apparatus 100, and Fig. 3 (b) is an A-A diagram in Fig. 3 (a) in the powder sintering cabinet apparatus 100. It is sectional drawing. FIG. 4 is a view for explaining the powder sintering table 132 in the powder sintering apparatus 100.

As shown in FIG. 3, the powder sintering apparatus 100 includes an airtight chamber 110 having a translucent window 112 and a powder sintering processing table 132 that is disposed inside the airtight chamber 110 and can be moved up and down. The powder layer M is disposed inside the hermetic chamber 110 and placed on the powder sintering table 132 (see FIG. 5 (d)).

0

3) Powder supply devices 150a, 150b, 150c as powder layer forming devices, and a laser beam to the powder layer M through the light-transmitting window 112.

0

And a laser beam irradiation device 170 for irradiation.

[0097] The powder sintering apparatus 100 includes a vacuum pump 116 and an exhaust valve 114 for exhausting the hermetic chamber 110, an Ar gas cylinder 120 for storing a gas to be introduced into the hermetic chamber 110, and an H gas.

2 A cylinder 120a, other (for example, ammonia decomposition gas) gas cylinder 120b, an introduction valve 118, and a heater 180 as a heating device for heating the structure are further provided.

[0098] The three powder supply devices 150a, 150b, and 150c are powder supply devices having a function of supplying the powder M onto the powder sintering table 132 as shown in FIG. 3 (a). , Respectively, shafts 152a, 152b, 152c, arms 154a, 1 54b, 154c rotatable around the shafts 152a, 152b, 152c, and powder inner yarns provided at the ends of the arms 154a, 154b, 154c. 156a, 156b, 156c and magnet parts 158a, 158b, 158c.

[0099] In the first embodiment, among the three powder supply devices 150a, 150b, and 150c, the force that the powder M is supplied only to the powder supply device 150a. The powder is supplied to the other powder supply devices 150b and 150c. Body M is supplied.

[0100] On the lower surface of the hermetic chamber 110, there are three powder supply device driving devices 160a, 160b, 160c (powder supply device driver) for controlling the rotational operation of the three powder supply devices 150a, 150b, 150c. Only moving device 160a is shown in Fig. 3 (b). ) Is installed. These three powder feeding device driving devices 160a, 160b, 160c respectively rotate the shafts 162a, 162b, 162c and the arms 164a, 164b, 164c, which can rotate around the shafts 162a, 162b, 162c, respectively. Motors 166a, 166b, 166c for the purpose, and magnet parts 168a, 168b, 168c provided at the tips of the arms 164a, 164b, 164c. The lower surface of the hermetic chamber 110 is made of permalloy, which is a magnetically permeable material.

[0101] The powder sintering apparatus 100 vibrates the powder in the powder storage units 156a, 156b, and 156c and the powder on the sintering apparatus powder sintering table 132. An ultrasonic oscillator (not shown) as a vibration supply device is further provided.

[0102] The laser beam irradiation device 170 is a UV laser beam irradiation device. As shown in Fig. 3 (b), the laser beam irradiation power is an Nd-YAG wavelength conversion (fourth harmonic) laser power that emits a UV laser beam. The oscillator 172, a two-dimensional scanning mirror 174 that reflects the UV laser beam, a condenser lens 176 that condenses the UV laser beam, and a control unit 178 that controls these operations are included.

[0103] As shown in FIG. 4, the powder sintering cache table 132 has a shaft portion 134 extending downward, and is freely rotatable in a lower portion of the powder sintering processing table storage portion 130. It is supported by the arranged powder sintering table support part 136. A magnet portion 138 is disposed below the powder sintering processing table support portion 136.

[0104] Below the powder sintering process table storage unit 130, a powder sintering process table drive device 140 is installed. The powder sintering processing table driving device 140 has a rotating body 142 having a magnet portion 142 disposed on the upper surface and configured to be rotatable by the rotation of the motor 146, and the powder sintering process is performed by the rotation of the rotating body 142. The rotation of the caulking table support 136 is controlled. Here, as shown in FIG. 4, since the shaft portion 134 and the powder sintering carriage table support portion 136 are threaded, the rotation of the powder sintering carriage table support portion 136 causes the rotation. The lifting / lowering operation of the powder sintering table 132 is controlled. The powder sintering table storage section 130 has a permalloy force that is a magnetically permeable material.

As shown in FIG. 3 (b), the powder sintering apparatus 100 is further provided with a heater 160 as a heating device that is disposed outside the hermetic chamber 110 and heats the structure. FIG. 5 is a process diagram shown for explaining the powder sintering cache process (step S 200). FIG. 6 is a perspective view schematically showing the structure during the sintering process. In FIG. 6, the illustration of the powder M existing around the structure 10 is omitted.

In the powder sintering process, first, as shown in FIG. 5 (a), the powder sintering table 132 at a predetermined position is lowered by a predetermined amount as shown in FIG. 5 (b). .

Next, as shown in FIG. 5 (c) to FIG. 5 (d), the powder supply device 150a is rotated in a state where the powder M is in the powder storage unit 156a, and the powder sintering processing table is turned on. Powder layer M on top of 132

Form 0.

[0107] Next, as shown in FIGS. 5 (e) to 5 (f), the powder layer M is transferred from the laser beam irradiation device 170.

0 A laser beam is irradiated to form the sintered layer M.

Next, the powder sintering table 132 is lowered by a predetermined amount as shown in FIG. 5 (g), and the powder supply device 150a is moved as shown in FIGS. 5 (h) to 5 (i). The powder layer M is formed on the powder sintering processing table 132 by rotating again.

0

In the powder sintering cache process, such processes are sequentially repeated below.

As described above, during the powder sintering process, the powder layer forming process, the sintered layer forming process, and the powder sintering process table lowering process are sequentially repeated to perform sintering. The layers are stacked to form a structure having the desired three-dimensional shape. As a result, a structure 10 having a three-dimensional structure as shown in FIG. 6 can be formed.

[0109] As described above, the stent manufacturing method according to Embodiment 1 is performed by performing the powder sintering process using the powder sintering apparatus 100.

[0110] For this reason, according to the stent manufacturing method of Embodiment 1, the laser beam is applied to the powder layer M.

0

Sintered layers M formed by selectively irradiating the film are laminated to form a structure having a desired three-dimensional shape, so that a stent having a relatively complicated shape can be easily manufactured. Is possible. As a result, for example, a stent having a shape (tapered shape) in which the outer diameter gradually decreases along the axial direction (tapered shape), a stent having a bifurcated portion, and the strut thickness at the central portion in the axial direction. It is possible to easily manufacture a stent having a relatively complicated shape, such as a stent that is thick and thin at both axial ends. [0111] Furthermore, according to the method for manufacturing a stent according to Embodiment 1, the powder contained in the powder layer M

0

By setting the composition to a desired composition, a stent having the desired composition can be manufactured. In this case, the composition of the powder M contained in the powder layer M is appropriately changed.

0

This makes it possible to manufacture a stent having a desired composition distribution.

[0112] In addition, according to the stent manufacturing method according to Embodiment 1, conditions for powder sintering (for example, what is the type of the powder M used for the powder layer M, what is the energy beam irradiation?

0

Do. ) And conditions for heat treatment of the structure after formation of the structure (for example, whether a strong heat treatment is performed or a weak heat treatment is performed), a stent having a desired density can be manufactured. In this case, the energy beam irradiation method is changed, the heat treatment of the structure is unevenly performed after the structure is formed, or the powder M contained in the powder layer M is

0

By appropriately changing the composition, it is possible to produce a stent having a desired density distribution.

[0113] In addition, according to the stent manufacturing method of Embodiment 1, sintering is performed in the powder layer M.

0

Since the powder M, which has been devastated, can be reused after collection, it is a manufacturing method with a high material yield.

[0114] Examples of the powder include powder made of austenitic stainless steel (for example, SUS316), powder having Ni-Ti alloy power, powder having Co-Cr alloy power, powder having Au-Cu alloy power, Au — Pt— Pd alloy power Various metal powders including various powders and various ceramic powders can be used. In this case, when ceramic powder is used as the powder, it is possible to use the ceramic powder alone, but it is preferable to use the ceramic powder together with the metal powder.

[0115] Further, according to the stent manufacturing method according to Embodiment 1, since a UV laser beam is used as the energy beam, the shape accuracy is relatively short (for example, number: zm or less). It is possible to form a structure, and as a result, it is possible to manufacture a stent in a relatively short period of time and with high shape accuracy (for example, several / zm or less).

[0116] Further, in the stent manufacturing method according to Embodiment 1, since the structure is formed in the airtight chamber 110, moisture, oxygen, nitrogen, organic matter, metal impurities, etc. from the outside are used. It is possible to manufacture a high-purity stent. In this case, it is preferable to perform the powder sintering process in a state where the hermetic chamber 110 is evacuated or an inert gas or a predetermined reducing gas is introduced into the hermetic chamber 110.

[0117] In the stent manufacturing method according to Embodiment 1, in the powder sintering process, the laser beam irradiation device 170 installed outside the hermetic chamber 110 is placed on the powder layer M.

0 Because it is supposed to be irradiated with the beam, impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities are prevented from entering the hermetic chamber 110 due to the laser beam irradiation, and a high-purity stent Can be manufactured.

[0118] In the stent manufacturing method according to Embodiment 1, the powder sintering table 132 is moved up and down using the powder sintering table driving device 140 installed outside the hermetic chamber 110. As a result, it is possible to prevent impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities from entering the hermetic chamber 110 due to the raising and lowering of the powder sintering cabinet table 132, and to manufacture high-purity stents. It becomes possible to do.

[0119] Also, in the stent manufacturing method according to Embodiment 1, the powder supply devices 150a, 150b, and 150c are used by using the powder supply device driving devices 160a, 160b, and 160c installed outside the hermetic chamber 110. Therefore, it is possible to prevent impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities from entering the hermetic chamber 110 due to the driving of the powder supply devices 150a, 150b, and 150c. It becomes possible to produce a high-purity stent.

[0120] In addition, in the stent manufacturing method according to Embodiment 1, by forming the structure 10 while heating, the temperature difference inside the structure 10 during the structure formation can be reduced. Distortion in the structure 10 can be reduced. In addition, by heating the structure using the heater 180 installed outside the hermetic chamber 110, moisture, oxygen, nitrogen, organic matter, metal impurities, etc. in the hermetic chamber 110 due to the heating of the structure 10. It is possible to manufacture a high-purity stent.

FIG. 7 is a flowchart for explaining the post-processing step (step S300) in the stent manufacturing method according to the first embodiment.

The post-processing step (step S300) in the stent manufacturing method according to Embodiment 1 includes the first heat treatment step (step S312) for increasing the sintered density of the structure, and the melt of the structure. A second heat treatment step (step S314) for performing a heat treatment, a third heat treatment step (step S316) for subjecting the structure to age hardening, and a surface polishing step (step S318) for polishing the surface of the structure. .

[0122] For this reason, the stent manufacturing method according to Embodiment 1 further includes a first heat treatment step for increasing the sintered density of the structure after the powder sintering step. By increasing the sintered density of the body, it becomes possible to produce a stent having predetermined physical properties (for example, hardness, flexibility, density, porosity, etc.).

In this case, when manufacturing a stent having an austenitic stainless steel (for example, SUS316) force, it is preferable to perform heat treatment under conditions of, for example, 800 to L 100 ° C for 30 to 90 minutes. As a result, the density ratio of 70 to 80% of the true metal density before the first heat treatment step is set to 97 to the LOO% density ratio of the true metal density after the first heat treatment step. be able to.

[0123] In addition, in the stent manufacturing method according to Embodiment 1, for example, when the sintered layer is formed while changing the components for each layer, each sintering is performed by the first heat treatment step. Since the tie layers can be alloyed together, stents of various compositions can be manufactured.

[0124] In addition, the stent manufacturing method according to Embodiment 1 further includes a second heat treatment step of performing a melt treatment of the structure after the first heat treatment step, and the structure is made of age-hardened metal. In this case, since the structure further includes a third heat treatment step for performing age hardening treatment of the structure, it becomes possible to manufacture a stent having a predetermined hardness and elasticity. [0125] As the second heat treatment, for example, in the case of manufacturing a stent having austenitic stainless steel (for example, SUS316) strength, rapid cooling is performed after heat treatment at 950 to 1250 ° C for 30 to 90 minutes. It is preferable to perform a heat treatment such as performing. In addition, for example, when manufacturing a stent made of Co—Cr alloy, heat treatment such as rapid cooling after heat treatment at 1100 to 1300 ° C. for 30 to 90 minutes is performed. It is preferable. For example, when a stent having an Au-Pt-Pd alloy strength is manufactured, a heat treatment may be performed in which quenching is performed after heat treatment is performed at 1000 to 1050 ° C. for 30 to 90 minutes. preferable.

[0126] As the third heat treatment, for example, when manufacturing a stent having Co—Cr alloy strength, it is preferable to perform the heat treatment under conditions of 700 to 850 ° C. for 30 to 180 minutes. For example, when manufacturing a stent made of an Au—Pt—Pd alloy, it is preferable to perform heat treatment under conditions of 800 to 960 ° C. and 30 to 180 minutes.

In this case, the first heat treatment step and the second heat treatment step can be used together, and the first heat treatment step, the second heat treatment step, and the third heat treatment step can be performed continuously.

[0128] The stent manufacturing method according to Embodiment 1 further includes a surface polishing step of polishing the surface of the structure. For this reason, since the powder adhering to the surface of the structure can be removed, the surface of the stent can be made smooth. In this surface polishing process, it is preferable to perform puff polishing, barrel polishing (wet or dry), electrolytic polishing or chemical polishing.

[0129] [Variations 1-3]

FIG. 8 is a view for explaining the powder sintering apparatus 100a according to the first modification. FIG. 9 is a view for explaining the powder sintering apparatus 100b according to the second modification. FIG. 10 is a diagram for explaining a powder sintering apparatus 100c according to Modification 3. In FIGS. 8 to 10, the illustration of the laser beam irradiation device 170 is omitted.

[0130] The powder sintering apparatus 100a, 100b, 100c according to the modified examples 1 to 3 basically has the same configuration as the powder sintering apparatus 100 according to the first embodiment. However, the powder sintering apparatus 100a, 100b, 100c according to the modified examples 1 to 3 is used for the powder droplets from the powder layer M and the powder particles.

0

This is different from the case of the powder sintering apparatus 100 according to the first embodiment in that it further includes a shielding means for shielding the evaporated material! [0131] Among them, in the powder sintering cake apparatus 100a according to the modified example 1, as shown in Fig. 8, as a shielding means, a gas supply apparatus 190a that constantly blows fresh gas to the translucent window 112. And a gas suction device 190b for sucking the gas blown to the translucent window 112.

In the powder sintering apparatus 100b according to the modified example 2, as shown in FIG. 9, a fresh gas is always provided between the powder sintering table 132 and the translucent window 112 as a shielding means. A gas flow supply device 192a for introducing a flow and a gas flow suction device 192b for sucking a gas flow from the gas flow supply device 192a are provided.

In the powder sintering apparatus 100c according to Modification 3, as shown in FIG. 10, the shielding means is intermittently or continuously between the powder sintering table 132 and the translucent window 112. A transparent film supply device 194 for feeding the transparent film is provided.

[0132] Thus, according to the powder sintering apparatus 100a, 100b, 100c according to the modified examples 1 to 3, the powder droplets from the powder layer M and the powder evaporation are shielded. With shielding means!

0

The powder droplets from the powder layer M and the evaporated powder adhere to the translucent window 112 and are translucent.

0

Deterioration of the light transmittance of the window 112 can be suppressed. For this reason, it is possible to always irradiate the laser beam under a certain condition during the formation of the structure, and the quality of the stent can be further improved.

[0133] [Variation 4]

FIG. 11 is a view for explaining a powder sintering apparatus 100d according to Modification 4. FIG. 11 (a) is a sectional view of the powder sintering apparatus 100d, and FIG. 11 (b) is a plan view of the powder sintering apparatus 100d. In FIG. 11, the illustration of the laser beam irradiation device 170 is omitted.

[0134] The powder sintering apparatus 100d according to Modification 4 basically has a configuration similar to that of the powder sintering apparatus 100 according to Embodiment 1, but Embodiment 1 The structure of the powder layer forming apparatus is different from the powder sintering apparatus 100 according to FIG.

That is, in the powder sintering cake apparatus 100d according to Modification 4, as shown in FIG. 11, the powder layer forming apparatus performs powder sintering processing on the powder sheet M on which the powder M is fixed. table

2

The powder sheet supply device 200 to be supplied to the And a cutting device 202 for cutting.

As described above, according to the powder sintered casing device lOOd according to the modified example 4, the powder sheet M on which the powder M is fixed can be supplied to the powder sintered casing table 132. To be possible, powder

2

Form a uniform powder layer M with a high layer M filling rate on the powder sintering table 132

0

Can be achieved.

[Variation 5]

FIG. 12 is a view for explaining a powder sintering apparatus 100e according to Modification 5. In FIG. 11, the illustration of the laser beam irradiation device 170 is omitted.

[0137] The powder sintering apparatus 100e according to Modification 5 basically has a configuration similar to that of the powder sintering apparatus lOOd according to Modification 4, but the modification The means for cutting the powder sheet M is different from the powder sintering apparatus lOOd according to 4.

2

In other words, in the powder sintering cage apparatus 100e according to the modified example 5, as shown in FIG. 12, the used portion of the powder sheet M is replaced with a laser beam irradiation apparatus 170 (not shown).

2

We are going to cut using. In this case, powder sheet M

When cutting the used part in 2, it is preferable to irradiate the laser beam with a higher output than when the sintered layer is formed.

[0138] Thus, in the powder sintering apparatus 100e according to the modification 5, the means for cutting the powder sheet M2 is different from the powder sintering apparatus lOOd according to the modification 4. As in the case of the powder sintering apparatus lOOd according to the modified example 4, the powder sheet M on which the powder M is fixed can be supplied to the powder sintering carriage table 132. Body M

2

Form a uniform powder layer M with a high packing ratio on the powder sintering table 132.

0

It becomes possible.

[0139] [Variation 6]

FIG. 13 is a view for explaining a powder sintering apparatus 100f according to Modification 6. FIG. 13 (a) is a plan view of the powder sintering apparatus 100f, and FIG. 13 (b) is a cross-sectional view taken along line AA in FIG. 13 (a) of the powder sintering apparatus 100f. is there.

[0140] The powder sintering apparatus 100f according to Modification 6 basically has a configuration similar to that of the powder sintering apparatus lOOd according to Modification 4, Powder sintering machine 1 The structure of the powder layer forming device is different from OOd.

That is, in the powder sintering cake apparatus 100f according to the modified example 6, as shown in FIG. 13, the powder layer forming apparatus has a powder sheet having a shape corresponding to the shape of the powder sintering processing table. Powder sheet supply device 210a, 210 that supplies M to powder sintering table 132

Three

b, 210c force also becomes.

[0141] As described above, the powder sintering apparatus 100f according to the modified example 6 differs from the powder sintering apparatus lOOd according to the modified example 4 in the configuration of the powder layer forming apparatus, but the powder M is Since it is possible to supply the fixed powder sheet M to the powder sintering carriage table 132, the modification 4

Three

As in the case of the powder sintering apparatus lOOd, it is possible to form a uniform powder layer M with a layer thickness with a high filling rate of the powder M on the powder sintering processing table 132.

0

[0142] [Variation 7]

FIG. 14 is a view for explaining a powder sintering apparatus 100g according to Modification 7. FIG. 14 (a) is a plan view of the powder sintering apparatus lOOd, and FIGS. 14 (b) and 14 (c) are cross-sectional views of the powder sintering apparatus lOOd. 14B is a cross-sectional view when the powder supply device 230 is on the powder sintering table 132, and FIG. FIG. 12 is a cross-sectional view when on the carpentry table 132. Further, in FIG. 14, the illustration of the laser beam irradiation device 170 is omitted.

[0143] The powder sintering apparatus 100g according to Modification 7 basically has a configuration similar to that of the powder sintering apparatus 100 according to Embodiment 1, but Embodiment 1 The structure of the powder layer forming apparatus is different from the powder sintering apparatus 100 according to FIG.

That is, in the powder sintering apparatus 100g according to the modified example 7, as shown in FIG. 14, the powder layer forming apparatus supplies the liquid M containing powder to the powder sintering processing table 132.

Four

It consists of a powder supply device 230 and a flattening device 250 for flattening liquid M containing powder.

Four

ing.

[0144] The powder supply apparatus 230 includes a shaft 232, an arm 234 rotatable around the shaft 232, a powder storage portion 236 provided at the tip of the arm 234, and a magnet portion 238. . The flattening device 250 includes a shaft 252, an arm 254 that is rotatable about the shaft 252, a flattening processing unit 256 that is provided at the tip of the arm 254 and can move up and down, and a magnet unit 258. . And flat By moving the carrier processing unit 256 up and down, the liquid M containing the powder supplied to the powder sintering table 132 is flattened.

Four

The powder supply device 230 and the flattening device 250 are driven by a powder supply device driving device 240 and a flat plate device driving device 260 installed outside the hermetic chamber 110.

[0145] Thus, the powder sintering apparatus lOOg according to the modified example 7 differs from the powder sintering apparatus 100 according to the first embodiment in the configuration of the powder layer forming apparatus, but in the first embodiment. As in the case of the powder sintering apparatus 100, a uniform powder layer M with a high layer thickness and a high packing ratio of the powder M

0 can be formed on the powder sintering table 132.

[0146] In this case, after supplying the liquid M containing powder to the powder sintering processing table, the liquid component

Four

It is preferable to form a sintered layer by irradiating a laser beam after removing.

[Variation 8]

FIG. 15 is a view for explaining a powder sintering apparatus 100h according to Modification 8. FIG. 15 (a) is a sectional view of the powder sintering apparatus 100h, and FIG. 15 (b) is a plan view of the powder sintering apparatus 100h.

[0148] The powder sintering apparatus 100h according to Modification 8 basically has a configuration similar to that of the powder sintering apparatus 100 according to Embodiment 1, but Embodiment 1 The structure of the heating apparatus is different from the powder sintering apparatus 100 according to the above.

That is, in the powder sintering cake apparatus 100h according to the modified example 8, as shown in FIG. 15, as the heating apparatus, the part where the structure is disposed is efficiently and locally heated. Two infrared heating devices 182 are provided.

As described above, the powder sintering apparatus 100h according to the modified example 8 has a different structure of the heating device. As in the case of the powder sintering apparatus 100 according to the first embodiment, the structure is being heated. By forming the body, it becomes possible to reduce the temperature difference inside the structure during the formation of the structure, so that distortion in the structure can be reduced. In addition, by heating the structure using an infrared heating device 182 installed outside the hermetic chamber 110, moisture, oxygen, nitrogen, organic matter, and metal impurities are added to the hermetic chamber 110 due to the heating of the structure. It is possible to manufacture a high-purity stent.

[0150] [Variation 9] FIG. 16 is a view for explaining the powder sintering apparatus lOOi according to the ninth modification. The powder sintering apparatus 100i (not shown) according to Modification 9 basically has a configuration that is very similar to the powder sintering apparatus 100h according to Modification 8. As shown in Fig. 16, the powder sintering process table drive device for controlling the lifting and lowering of the powder sintering process table uses a drive device using a linear motor, and therefore the powder according to Modification 8 is used. It differs from the case of body sintering machine 100h.

[0151] As shown in FIG. 16, the powder sintering table 270 is provided with a magnet portion 272, and around the powder sintering processing table storage portion 130, there is an electromagnet portion supporting portion. An electromagnet portion 274 supported by 276 is provided. Then, by controlling the voltage applied to the electromagnet unit 274, the lifting / lowering operation of the powder sintering table 270 is controlled.

[0152] Thus, in the powder sintering apparatus lOOi according to Modification Example 9, the modification example is that the driving apparatus using the linear motor is used as the powder sintering process table drive apparatus. The force different from the case of the powder sintering apparatus 100h according to 8 is modified. As in the case of the powder sintering apparatus 100h according to the modified example 8, the external force can also raise and lower the powder sintering table 270. It is possible to suppress the entry of moisture, oxygen, nitrogen, organic matter, metal impurities and other impurities into the hermetic chamber 110 due to the lifting and lowering of the powder sintering table 270 and high purity. Can be manufactured.

[Variation 10]

FIG. 17 is a view for explaining a powder sintering apparatus 100j according to Modification 10. In FIG. 17, the illustration of the laser beam irradiation apparatus 170 is omitted.

[0154] The powder sintering apparatus 100j according to Modification 10 basically has a configuration similar to that of the powder sintering apparatus 100 according to Embodiment 1, but Embodiment 1 The structure of the heating apparatus is different from the powder sintering apparatus 100 according to the above.

That is, the powder sintering apparatus 100j according to the modified example 10 includes a high-frequency heating device 184 as a heating device, as shown in FIG.

Thus, the powder sintering apparatus 100j according to the modified example 10 includes the high-frequency heating apparatus 184 instead of the heater 180 as a heating apparatus, and thus the powder sintering apparatus 1 according to the first embodiment. Force different from the case of 00 Similar to the case of the powder sintering apparatus 100 according to Embodiment 1, by heating the structure using the high-frequency heating device 184 installed outside the hermetic chamber 110, the structure Due to the heating, impurities such as moisture, oxygen, nitrogen, organic matter, and metal impurities are prevented from entering the hermetic chamber 110, and it becomes possible to manufacture a high-purity stent.

[Embodiment 2]

FIG. 18 is a flow chart shown for explaining the manufacturing method of the stent according to the second embodiment.

As shown in FIG. 18, the manufacturing method of the stent according to Embodiment 2 is performed after the surface polishing step.

The method further includes a drug impregnation step of impregnating the structure with the drug.

[0157] Therefore, according to the stent manufacturing method of Embodiment 2, DES (Drug—Eluting Stent (drug-eluting stent) in which a necessary drug is impregnated in the pores of the structure body

) Can be manufactured.

In this case, in the first heat treatment step or the like, the characteristics as DES (for example, drug carrying characteristics, drug Release characteristics etc.) can be made desired.

[0159] As the drug, a growth inhibitor, a growth inhibitory and immunosuppressant, an immunosuppressant, an extracellular matrix modifier, an endothelial repair promoter, or a drug appropriately combined with these can be preferably used.

[Embodiment 3]

FIG. 19 is a flowchart for explaining the stent manufacturing method according to the third embodiment.

The stent manufacturing method according to Embodiment 3 is a stent manufacturing method in which the sintered layer is formed while changing the composition for each layer in the powder sintering process. In this case, the component is changed by selecting a desired powder (either power of powder A or powder B) in the powder selection step (step S222) in FIG.

[0161] In the stent manufacturing method according to Embodiment 3, two of the three powder supply devices 150a, 150b, 150c (not shown) described in Embodiment 1 are used. Powder A and powder B are supplied.

[0162] Therefore, according to the method for manufacturing a stent according to Embodiment 3, it is possible to alloy each sintered layer integrally by heat-treating the structure after forming the structure. It becomes possible to manufacture stents of various compositions (for example, stents made of Co—Cr alloy).

[0163] [Embodiment 4]

FIG. 20 is a flow chart for explaining the stent manufacturing method according to the fourth embodiment. FIG. 21 is a view for explaining the structure of the stent manufactured by the stent manufacturing method according to the fourth embodiment.

[0164] As shown in FIG. 20, the stent manufacturing method according to Embodiment 4 is a stent manufacturing method in which the sintered layers are formed by changing the components during the powder sintering process. is there. In this case, the component is changed by selecting a desired powder (any one of powder A, powder B, and powder C) in the powder selection step (step S232) in FIG.

[0165] Note that, in the stent manufacturing method according to Embodiment 4, powder A and powder B are respectively added to the three powder supply devices 150a, 150b, and 150c (not shown) described in Embodiment 1. And powder C is supplied.

[0166] Therefore, according to the stent manufacturing method according to Embodiment 4, it is possible to alloy each sintered layer integrally by performing heat treatment of the structure after forming the structure. It becomes possible to produce stents of various compositions (for example, stents made of Au—Pt—Pd alloy).

[0167] According to the method for manufacturing a stent according to Embodiment 4, it is also possible to manufacture a stent having a composition distribution in which the composition changes.

For example, when the sintered layer is formed by gradually changing the components during the process, it is possible to manufacture a stent having a thread and component fabric that changes smoothly. In addition, when a sintered layer is formed by changing the components in a stepped manner during the process, a stent having a stepped composition distribution can be manufactured. For example, as shown in FIG. 21, in the axial central portion 22, the weight ratio of Au, Pt, and Pd is an alloy of “Au: Pt: Pd = 20: 40: 40”. 811, 1 ^ and 1 ³ (weight ratio of 1 is `` 811:? 1 ;:? (1 = 6 By using an alloy of “0:20:20”, it is possible to manufacture a stent 20 that is hard at the axial center portion 24 and highly flexible at both axial end portions 22. As a result, for example, it is possible to manufacture a stent that can support and support the blood vessel after placement of the stent, which hardly damages the blood vessel when inserting the stent.

[0168] The stent manufacturing method and the powder sintering apparatus according to the present invention have been described based on the above embodiments, but the present invention is not limited to the above embodiments and departs from the gist thereof. However, the present invention can be carried out in various modes within the scope, and for example, the following modifications are possible.

(1) In the manufacturing method of the stent according to each of the above embodiments, the force using a UV laser beam irradiation apparatus as the energy beam irradiation apparatus is not limited to this. For example, a laser beam irradiation device in the visible region or the infrared region can be used, and an electron beam irradiation device or an ion beam irradiation device can also be used.

(2) In the powder sintering apparatus according to each of the above embodiments, the force using a flat quartz glass substrate as the translucent window is not limited to this. For example, a curved quartz glass substrate or other substrate can be used as the translucent window. When configured in this manner, the focusing power of the laser beam is increased, and powder sintering with higher shape accuracy can be performed.

(3) In the stent manufacturing method according to each of the above embodiments, the force for forming the structure along the axial direction of the stent is not limited to this. For example, a structure can be formed along the diameter direction of the stent.

(4) In the stent manufacturing methods according to the above embodiments, the structure is formed using metal powder, but the present invention is not limited to this. The structure may be formed using metal powder coated with resin! However, it is also possible to form a structure using both powdered resin powder and metal powder.

(5) In the stent manufacturing method according to each of the embodiments described above, the force for forming the structure using the metal powder is not limited to this. A structure may be formed using a ceramic powder. In this case, it is possible to use ceramic powder alone. It is preferable to use ceramic powder together with metal powder. Explanation of symbols

10 ··· Structure, 12 ··· Strut, 20 ·· Stent, 22 ··· Central part, 24 ························································ Closed chamber, 112 ... Translucent window, 114 ... Exhaust valve, 116 ... Vacuum pump, 118 ... Introduction valve, 120 ... Ar gas cylinder, 120a --- H gas cylinder

2 chambers, 120b… other gas cylinders, 130 ·························································································································· ... Magnetic part, 140 ... Powder sintering processing table drive device, 142 ... Rotating body, 144 ... Magnetic part, 146 ... Motor, 150a, 150b, 150c, 210a, 210b, 210c, 230 ... Body supply device, 152a, 152b, 152c, 212a, 212b, 212c, 232 ... axis, 154a, 154b, 154c, 214a, 214b, 214c, 234 ... arm, 156a, 156b, 156c, 216a, 216b, 216c, 236 ... Powder storage unit, 158a, 158b, 158c, 218a, 218b, 218c, 238 ... Magnet unit, 160a, 22 Oa, 240 ... Powder feeder drive unit, 162a, 222a, 242, 262 ··· axis, 164a, 224a, 244, 264 ··· arm, 166a, 226a, 246, 266 ··· motor, 168a, 228a, 248, 268 ... magnet part, 170 ... laser beam irradiation device, 172 ... Laser oscillator, 174 ... Two-dimensional scanning mirror, 176 ... Condensing lens, 178 ... Control 180 Heater 182 Infrared heating device 1 84 High frequency heating device 190a ... Gas supply device 190b Gas suction device 192a Gas flow supply device 192b Gas flow suction device 194 Transparent sheet feeding device, 200 ··· Powder sheet feeding device, 202 ··· Cutting device, 250 ··· Planarizing device, 252 ··· Axis, 254 ··· arm, 25 6 ····························· 258 Magnet part, 260 ... Flater driving device, 270 ... Powder sintering processing table, 272 ... Magnet part, 274 ... Electromagnet part, 900 ... Laser processing equipment, 910 ... Laser irradiation 912 ... laser oscillator, 914, 916 ... movable mirror, 918 ... condensing lens, 920 ... movable chuck, 930 ... metal tube, 940 ... stent, 942 ... center, 944 ... Both ends, 946 ... Strut, L ... Laser beam, M ... Powder, M ... Powder layer, M ... Sintered layer, M,

0 1 2

M ... powder sheet, M ... liquid containing powder

Claims

The scope of the claims

[1] Sintered layer formation in which a powder layer is formed on a powder sintering process table using a powder layer forming apparatus and then the powder layer is selectively irradiated with an energy beam to form a sintered layer A structure having a desired three-dimensional shape is formed by stacking the sintered layers by sequentially repeating a process and a powder sintering processing table lowering step of lowering the powder sintering processing table by a predetermined amount. A method for manufacturing a stent, comprising a powder sintering process to be formed.

[2] The method for producing a stent according to claim 1, wherein

A method for manufacturing a stent, wherein the structure is formed in an airtight chamber.

[3] In the stent manufacturing method according to claim 2,

The energy beam is a laser beam, and a laser beam irradiation device installed outside the hermetic chamber is used to irradiate the powder layer with a laser beam.

[4] In the method for producing a stent according to claim 2 or 3,

A method for manufacturing a stent, wherein the powder sintering table is moved up and down using a powder sintering table driving device installed outside the hermetic chamber.

[5] In the method for producing a stent according to any one of claims 2 to 4,

A method for manufacturing a stent, comprising: driving a powder layer forming apparatus using a powder layer forming apparatus driving device installed outside the hermetic chamber.

[6] In the stent manufacturing method according to any one of claims 2 to 5,

A method of manufacturing a stent, comprising forming the structure while heating using a heating device installed outside the hermetic chamber.

[7] In the method for producing a stent according to any one of claims 1 to 6,

A method for producing a stent, comprising forming a sintered layer while changing the components of the powder layer.

[8] In the method for producing a stent according to any one of claims 1 to 7,

After the powder sintering process,

The stent manufacturing method further comprising a first heat treatment step for increasing the sintered density of the structure.

[9] The method for manufacturing a stent according to claim 8,

After the first heat treatment step,

The method for producing a stent, further comprising a second heat treatment step for performing a solution treatment of the structure.

[10] The method for producing a stent according to claim 9,

After the second heat treatment step,

The method for manufacturing a stent, further comprising a third heat treatment step of performing an age hardening treatment on the structure.

[11] In the method for producing a stent according to any one of claims 1 to 10,

A method for producing a stent, further comprising a surface polishing step of polishing the surface of the structure.

[12] Claims 1 to: In the method for producing a stent according to any one of L1,

A method for producing a stent, further comprising a drug impregnation step of impregnating the structure with a drug.

[13] Using a powder layer forming apparatus, a powder layer made of a resin powder coated metal powder is formed on a powder solidification table, and then the powder layer is selectively irradiated with an energy beam. The powder solidified layer is formed by sequentially repeating a powder solidified layer forming step of melting the resin to form a powder solidified layer and a powder solidifying table lowering step of lowering the powder solidified table by a predetermined amount. A method for producing a stent, comprising a powder solidifying step of forming a structure having a desired three-dimensional shape by laminating.

[14] Using a powder layer forming apparatus, after forming a powder layer made of a resin powder and a metal powder on a powder solidification table, the powder layer is selectively irradiated with an energy beam. By repeating a powder solidified layer forming step of melting the resin powder to form a powder solidified layer and a powder solidified table lowering step of lowering the powder solidified table by a predetermined amount, the powder is repeated. A method for manufacturing a stent, comprising a powder solidification step of forming a structure having a desired three-dimensional shape by laminating body solidification layers.

[15] The method for producing a stent according to claim 13 or 14,

Production of a stent, further comprising a degreasing step after the powder solidification step Method.

[16] an airtight chamber having a translucent window;

A powder sintering processing table arranged inside the hermetic chamber and capable of moving up and down, and a powder layer forming device arranged inside the airtight chamber and forming a powder layer on the powder sintering processing table When,

A powder sintering apparatus, comprising: a laser beam irradiation device that is disposed outside the hermetic chamber and irradiates the powder layer with a laser beam through the translucent window.

[17] In the powder sintering apparatus according to claim 16,

The laser beam irradiation apparatus is a UV laser beam irradiation apparatus.

[18] The powder sintering apparatus according to claim 16 or 17,

The translucent window has a curved surface part, and is a powder sintering apparatus characterized by the above-mentioned.

[19] In the powder sintering apparatus according to any one of claims 16 to 18,

The powder layer forming apparatus comprises a powder supply apparatus having a function of supplying powder onto the powder sintering process table.

[20] In the powder sintering apparatus according to claim 19,

A powder sintering apparatus comprising a plurality of powder supply apparatuses as the powder supply apparatus.

[21] In the powder sintering apparatus according to claim 19 or 20,

A powder sintering apparatus, further comprising vibration supply means for applying vibration to the powder.

[22] In the powder sintering apparatus according to any one of claims 16 to 18,

The powder layer forming apparatus comprises one or a plurality of powder sheet supply devices for supplying a powder sheet on which powder is fixed to the powder sintering table. apparatus.

[23] The powder sintering apparatus according to any one of claims 16 to 18,

The powder layer forming apparatus comprises one or a plurality of powder supply devices for supplying a liquid containing powder to the powder sintering processing table.

24. A powder sintering table drive according to any one of claims 16 to 23, wherein the powder sintering table is disposed outside the hermetic chamber and moves up and down the powder sintering table. A powder sintering apparatus, further comprising an apparatus.

[25] In the powder sintering apparatus according to any one of claims 16 to 24,

A powder sintering apparatus, further comprising: a powder layer forming device driving device disposed outside the hermetic chamber and driving the powder layer forming device.

[26] The powder sintering apparatus according to any one of claims 16 to 25,

A powder sintering apparatus, further comprising a heating device that is disposed outside the hermetic chamber and heats the structure.

[27] In the powder sintering apparatus according to any one of claims 16 to 26,

A powder sintering apparatus, further comprising shielding means for shielding the powder droplets from the powder layer and the evaporated powder.

[28] In the powder sintering apparatus according to claim 27,

The shielding means includes a gas supply device that blows gas onto the translucent window, and a gas arch I device that absorbs gas I blown against the translucent window. Body sintering machine.

[29] In the powder sintering apparatus according to claim 27,

The shielding means includes a gas flow supply device for introducing a gas flow between the powder sintering processing table and the translucent window, and a gas flow for sucking the gas flow of the gas flow supply device force. A powder sintering apparatus comprising a suction device.

[30] In the powder sintering apparatus according to claim 27,

The shielding means has a transparent film supply device for continuously or intermittently feeding a transparent film between the powder sintering processing table and the translucent window. apparatus.