JP2008303516A - Titanium filament and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a titanium filament having a length of ≥5 m with a small diameter and useful in a medical field, and a method for efficiently producing the titanium filament. <P>SOLUTION: The superfine titanium filament 17 is prepared by inserting one titanium wire 10 into a metal tube 11 excellent in malleability, and subjected to swaging and wire drawing to be a coated wire material 15, annealing the coated wire material 15 at 500-800°C, bundling two or more annealed coated wire materials 15 and putting the coated wire material into an outer layer material 16 including a metal tube excellent in malleability, subsequently removing the coating material 14 and the outer layer 16 by dissolving them with acid. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a titanium long fiber, particularly a titanium long fiber used in the medical field and a method for producing the titanium long fiber.

Japanese Patent Laid-Open No. 11-81050 Japanese Patent Laid-Open No. 6-344021 Japanese Patent Publication No.49-23755 Japanese Patent Publication No.56-1162

  Patent Document 1 discloses titanium (alloy) fibers having a circle equivalent diameter of 5 μm to 30 μm, which are titanium fibers or titanium alloy fibers used for a catalyst and have an approximately elliptical cross section and an uneven surface formed to increase the surface area. It is disclosed. The equivalent circle diameter is a numerical value indicating the size of the irregular cross section, and means the diameter of a circle having the same cross sectional area. The reason for reducing the wire diameter and increasing the surface area is to improve the function as a catalyst.

  Furthermore, in Patent Document 1, a pure titanium wire is inserted while forming an electric-welded tube with a diameter of 6 mm with a strip of mild steel (SPCC), drawn to a diameter of 4.3 mm, and the inner surface of the tube and the core wire are brought into close contact with each other. And then annealed in an electric furnace, and then inserted a number of the obtained coated titanium wires into another mild steel pipe, subjected to wire drawing and heat treatment, and melted and separated the mild steel to obtain the outer Disclosed is a titanium fiber having a diameter of about 8 μm. Further, the carbon content of mild steel is preferably 0.25% by weight or less, particularly preferably 0.12% by weight or less, the highest ultimate temperature for annealing is preferably 580 ° C. to 650 ° C., and the coating is preferably thicker. However, it is described that 5 to 20%, particularly 8 to 15%, of the diameter of the wire to be coated is preferable in consideration of the time and labor of melting.

  Moreover, in patent document 1, as a preferable cross-sectional shape of a titanium fiber, a substantially circular shape, an ellipse shape, and a polygonal shape can be cited. A flat shape and a curved shape can increase the surface area but are not preferable. The unevenness formed on the surface of the fiber is caused by bending of the crystal of the mild steel to be coated, and does not extend with the same cross-sectional shape. Further, no particular mention is made of the length of the titanium fiber.

  In Patent Document 2, a metal wire having a clad structure with a high-strength metal coating such as stainless steel or steel around a core material such as aluminum or copper, which has low strength and is difficult to process the core wire, is dissolved with acid around the core wire. A manufacturing method of a metal wire having a clad structure is disclosed, in which an outer layer material that can be formed is provided and focused and drawn, and then the outer layer material is dissolved with an acid. Titanium and titanium alloys are mentioned as metal coatings. Patent Document 3 discloses a method of manufacturing metal fibers by a focused wire drawing method in which a metal wire is double-plated around a metal wire, and a hexagonal shape is schematically illustrated as a cross-sectional shape of the obtained metal fiber. ing.

  In Patent Document 4, a metal titanium slab having a thickness of 130 mm, a width of 550 mm, and a length of 3000 mm is surrounded by a mild steel plate (SS34) having a thickness of 15 mm, heated, and hot-rolled to a thickness of 4 mm. A manufacturing method of a titanium plate material is disclosed in which the thickness is set to 150 mm, the width is 550 mm, the thickness is further reduced to 4 mm by cold rolling, and then the mild steel plate is separated. This has a rectangular cross-sectional shape and a length of several meters or more, but is not a fiber.

  In the production method of Patent Document 1, the content of “characterized by setting the maximum temperature of the composite wire to 580 to 650 ° C.” in the method of focusing and drawing by coating mild steel around the titanium wire is described. However, since the tensile strength is almost the same under these conditions, it is not possible to obtain a long titanium fiber by breaking during wire drawing. That is, the crystal structure of the pure titanium wire is a close-packed hexagonal lattice (hcp), and the crystal structure of the coated mild steel is a body-centered cubic lattice (bcc) or a face-centered cubic lattice (fcc). If the same stress is applied, the plastic deformability is bcc> fcc> hcp, and the hcp of the titanium wire has a crystal structure that is least susceptible to plastic deformation. Therefore, the ratio of “plastic deformation + elastic deformation” with respect to the load is large. For this reason, when the relationship of [tensile strength of titanium wire = tensile strength of metal tube] is satisfied, the metal tube undergoes plastic deformation (change in the entire length), whereas the titanium wire undergoes plastic deformation + elastic deformation and elastic deformation. It is easy to break by accumulation of. Therefore, a long titanium wire cannot be drawn. In addition, the titanium wire of Patent Document 1 is particularly used for a catalyst, and the surface of the titanium wire is already formed with irregularities formed by crystal grains of mild steel, so that the fibers are difficult to slip and entangle. It is difficult to handle when bundling.

  On the other hand, with respect to the production methods of Patent Documents 2 and 3, long titanium fibers and flat titanium fibers cannot be obtained. The method for producing a titanium plate material of Patent Document 4 can produce a flat titanium plate material having a length of several meters, but cannot be applied to a method for producing titanium fibers.

  An object of the present invention is to provide a method for efficiently producing a titanium fiber that is as thin and long as possible, even though a titanium wire that is difficult to plastically deform is coated with a metal that is easily plastically deformed.

  The method for producing a titanium long fiber of the present invention (Claim 1) is a method of reducing the diameter by coating a titanium wire made of metal titanium or an alloy material mainly composed of metal titanium with a coating material made of a metal having excellent malleability, The obtained coated wire was annealed at 500 to 800 ° C. for 1 to 10 minutes, bundled with a plurality of annealed coated wires, put into a metal tube having excellent malleability, and then [tensile strength of coated wire ≦ the The metal pipe is stretched by 50 m or more so as to satisfy the metal tensile strength], and then the metal pipe and the coating material are dissolved and removed with an acid. In such a method for producing a titanium long fiber, it is preferable that the metal tube is drawn by 70 m or more by the drawing process (claim 2). Furthermore, it is preferable to reduce the diameter to 15 to 25% by a swaging process after drawing a plurality of the coated wires into a metal tube and before the wire drawing process (Claim 3). Further, after drawing a plurality of coated wires together with the metal tube, it can be rolled into an irregular cross section before being dissolved with an acid (Claim 4).

  In the method for producing a coated wire of the present invention (Claim 5), one titanium wire is put in a metal tube having excellent malleability, and then [tension strength of titanium wire ≦ tensile strength of the metal] is satisfied. Thus, the diameter is reduced by wire drawing to form a coated wire. In this case, it is preferable that the single titanium wire is put in a single wire metal tube, then the diameter is reduced to 15 to 25% by a swaging process, and then the wire drawing is performed. Moreover, it is preferable that the outer diameter of the metal tube for single wires is 2 to 6 times the outer diameter of the titanium wire.

  The titanium long fiber of the present invention (Claim 8) is manufactured by any one of the above-described methods for manufacturing a titanium long fiber, and further has an equivalent circle diameter of 100 μm or less and a length of 20 m or more. Such a titanium long fiber preferably has an equivalent circle diameter of 15 μm or less and a length of 50 m or more. Moreover, a cross section is substantially polygonal shape, and can also be 15 micrometers or less on one side (Claim 10). Further, the cross-sectional shape may be a substantially star shape (claim 11).

  In the above-mentioned titanium long fiber, it is also possible to have a flat cross-sectional shape with a long side ratio of 2 to 8.5 times with respect to the short side 1 (claim 12). Moreover, in the above-mentioned titanium long fiber, it is preferable that the cross-sectional shape continues substantially constant in the length direction and the surface shape is smooth in the length direction (Claim 13).

  Furthermore, in any of the above-mentioned titanium long fibers, the whole or a part of the cell culture carrier can be constituted by entanglement or braiding (claim 14).

  In addition, any of the above-mentioned titanium long fibers can be configured to constitute the whole or a part of the biological tissue-derived scaffold by entanglement or braiding (claim 15). Further, in any of the above-mentioned titanium long fibers, one of the titanium long fibers can be entangled or braided to constitute a biological tissue-inducing scaffold (claim 16). The “scaffold” includes an “implant” that is implanted in a living body.

  The method for producing a titanium long fiber of the present invention (Claim 1) is a method of focusing wire drawing after annealing a titanium wire coated with a metal having excellent malleability and reduced in diameter at 500 to 800 ° C. for 1 to 10 minutes in advance. Finely processed by the method. Further, since the converging wire drawing is performed under the conditions satisfying [the tensile strength of the coated wire ≦ the tensile strength of the metal], it is difficult to break even if the wire drawing is performed for 50 m or more. That is, the present inventor has found that, by satisfying this condition, the metal tube is plastically deformed more than “plastic deformation + elastic deformation of the titanium wire”, so that the long wire can be drawn longer than 50 m without breaking the titanium wire. It was. Moreover, the long fiber which is easy to use by medical treatment etc. can be obtained by drawing at 50 m or more, especially 70 m or more. Titanium is widely used in medicine because of its high biocompatibility, but wear powder generated from the end of the titanium fiber tends to cause an inflammatory reaction in the surrounding soft tissue. Therefore, it is preferable to use titanium fibers used for medical treatment with those having as few ends as possible, that is, long fibers.

  In the wire drawing process, it is preferable to draw 70 m or more for each metal tube. When winding a titanium long fiber for artificial tooth roots or living tissue culture, about 70 m is required, and by drawing to 70 m or more, it can be adapted to various applications.

  When a plurality of coated wires are bundled and put into a metal tube, and before the wire drawing process, the surface reduction rate is reduced to 15 to 25% by swaging (Claim 3). Since it can be set high and the plastic working in the radial direction can be performed strongly, the diameter can be reduced by the drawing without breaking the titanium wire. Furthermore, the degree of adhesion between the metal tube and the coated wire is also increased. Thereby, even if it draws to 50 m or more and also 70 m or more, it does not break. The area reduction rate here is “[(original cross-sectional area−cross-sectional area after processing) / original cross-sectional area] × 100 (%)”.

  After drawing a plurality of coated wires together with the metal tube and before rolling with an acid to form a deformed cross section (Claim 4), the rolling rate can be arbitrarily set to finally The aspect ratio of the cross-sectional shape of the titanium wire obtained can be controlled.

  In the step of coating the titanium wire with a coating material, one titanium wire is put in a metal tube having excellent malleability and then drawn so as to satisfy [Tensile strength of titanium wire ≦ Tensile strength of the metal]. When the diameter is reduced by processing to form a coated wire (Claim 5), the plastic working rate in the radial direction can be set high, and the wire can be drawn without being disconnected when drawn. As a result, when focused wire drawing is performed with a bundle of the respective coated wires, the metal tube and the individual coated wires are drawn together without shifting, and even if they are drawn to a length of 50 m or more, they are not broken. .

  In the method for producing a coated wire of the present invention (Claim 6), a single titanium wire is put into a single wire metal tube, and then the diameter is reduced to 15 to 25% by a swaging process, and then the wire is drawn. Since the processing is performed, the adhesion between the metal tube and the titanium wire is increased. As a result, when the respective coated wires are bundled and drawn, the metal tube and the individual coated wires are drawn together without any deviation and drawn to a length of 50 m or more, and further to 70 m or more. However, since it is not disconnected, it is suitable as an intermediate molded product for producing titanium long fibers.

  When the outer diameter of the metal tube into which the single titanium wire is placed is 2 to 6 times the outer diameter of the titanium wire (Claim 7), the thickness of the metal tube is thick, so that a titanium long fiber is obtained. When wire drawing is performed, the titanium wire is sufficiently protected by the metal tube and is not easily broken. Furthermore, productivity is high. That is, in the case of less than twice, since the unevenness of the cross-sectional shape is too large after wire drawing, it is disconnected and it is difficult to make the length longer. On the other hand, if it exceeds 6 times, the cross-sectional area ratio of the titanium wire with respect to the focused wire to be drawn is extremely reduced, and the productivity is remarkably lowered.

  The titanium long fiber of the present invention (Claim 8) is a titanium long fiber having an equivalent circle diameter of 100 μm or less and a length of 20 m or more produced by any one of the above production methods. It is suitable as a titanium fiber for medical use such as constituting a web.

  In such a titanium long fiber, when the equivalent circle diameter is 15 μm or less and the length is 50 m or more (Claim 9), it is more suitable as a medical titanium fiber.

  Further, when the cross section is substantially polygonal and one side thereof is 15 μm or less (claim 10), when the titanium fibers or the titanium wires are welded or diffusion bonded to the base material, the bonding strength is higher than that of the circular cross section. Moreover, the shape is stabilized when entangled. Diffusion bonding is a method in which a base material is brought into close contact, and is joined by utilizing atomic diffusion generated between joint surfaces by applying pressure to the extent that plastic deformation does not occur as much as possible under a temperature condition below the melting point of the base material. . When the cross-sectional shape is substantially a star (claim 11), the same effects as in the case of a polygonal cross-section are obtained, and the production is easy.

  When the long titanium fiber has a flat cross-sectional shape with a long side ratio of 2 to 8.5 times with respect to the short side 1 (Claim 12), it is more suitable as a titanium wire for medical use. Furthermore, there is an advantage that the bonding strength at the time of welding or diffusion bonding can be sufficiently secured, and the porosity between the titanium fibers can be freely adjusted.

  In the titanium long fiber, when the cross-sectional shape is substantially constant in the length direction and the surface shape is smooth in the length direction (Claim 13), the resistance when drawn in the axial direction is small. Therefore, it is easier to handle and it is easy to keep the porosity constant when braiding.

  In any of the above-mentioned titanium long fibers, when the whole or part of the cell culture carrier is constituted by entanglement or braiding (claim 14), the efficiency of cell culture is high. In addition, it is possible to ensure sufficient bonding strength when entangled or braided, and to easily adjust the porosity. In addition, the cell culture carrier obtained by entanglement or braiding has high cell culture efficiency.

  In any of the above-mentioned titanium long fibers, in order to constitute all or part of a biological tissue-derived scaffold (including an implant) by entanglement or braiding (claim 15), It can be guided efficiently. In addition, it is possible to ensure sufficient bonding strength when entangled or braided, and to easily adjust the porosity. In particular, when a living tissue induction type scaffold is constructed by entanglement or braiding using one titanium long fiber, the end of the titanium long fiber has only two ends in the obtained scaffold. Inflammatory reactions are unlikely to occur in tissues. Further, it is possible to sufficiently secure the bonding strength when entangled or braided, and to easily adjust the porosity.

  Next, the titanium fiber of the present invention and the production method thereof will be described with reference to the drawings. FIG. 1a is a partial process diagram illustrating an embodiment of the method for producing a titanium long fiber of the present invention, FIG. 1b is a partial process diagram illustrating a change in cross-sectional shape according to the process of FIG. 1a, and FIG. 2a is a subsequent process of the process of FIG. 2b is a partial process diagram showing the subsequent process of FIG. 1b, FIG. 3 is an enlarged cross-sectional view of the focusing line obtained in the sixth process of FIG. 1, and FIG. FIG. 5 is a partial process diagram showing another embodiment of the method for producing a titanium long fiber of the present invention, and FIG. 6 is a flat converging obtained in the ninth step of FIG. FIG. 7 is an enlarged perspective view of the long titanium fiber after the acid treatment of the flat converging line in FIG. 6, FIG. 8 is a micrograph showing a cross section of the converging line in the embodiment of the present invention, and FIG. Is an enlarged micrograph of the main part of FIG. 8, FIG. 10 is a microphotograph showing one embodiment of the titanium long fiber of the present invention, and FIG. Micrograph showing a cross section of the focused beam in another embodiment, and FIG. 12 is an enlarged micrograph of FIG.

  In the method for producing a titanium long fiber shown in FIGS. 1a and 2a, first, the first step S1 of inserting the titanium wire 10 into the metal tube 11 for single wire is performed, and then the titanium wire 12 containing the metal tube obtained is scanned. Aging is performed to reduce the outer diameter somewhat (second step S2), and then the wire is further drawn to reduce the diameter to 0.1 to 1 mm (third step S3). As a result, a coated wire (coated wire) 15 obtained by coating the titanium fine wire 13 with the metal coating material 14 is obtained.

  The titanium wire 10 used as the material in the above process is made of titanium metal (pure titanium) having a diameter of about 0.5 to 4 mm. However, alloys (titanium alloys) mainly composed of titanium, such as α alloys, β alloys, α-β alloys, and the like can also be used. In this specification, “titanium wire” includes both of them. As a material of the metal tube 11 for single wires, a metal excellent in malleability such as mild steel, aluminum, and stainless steel satisfying [Tensile strength of titanium wire ≦ Tensile strength of the metal] is used. In the case of mild steel, a carbon content of about 0.05 to 0.3 wt% is used.

  The inner diameter of the metal tube 11 is almost the same as the outer diameter of the titanium wire 10, and it is sufficient that the titanium wire 10 can be easily inserted. The outer diameter of the metal tube 11 is preferably about 2 to 6 times the diameter of the titanium wire 10, and more preferably about 3 to 5 times. That is, the thickness of the metal tube 11 is about 0.5 to 2.5 times the diameter of the titanium wire, more preferably about 1 to 2 times. When the thickness of the metal tube 11 is less than 0.5 times the diameter of the titanium wire 10, the metal tube 11 is thin and the cross-sectional shape of the titanium wire becomes large, so the wire is disconnected and cannot be elongated. On the other hand, if the thickness of the metal tube 11 exceeds three times the diameter of the titanium wire 10, the cross-sectional area of the titanium wire is too small and the production efficiency (yield) becomes low.

  The swaging process used in the second step S2 is a kind of forging process in which a metal is pressed in a radial direction with a tool and plastically deformed to reduce the diameter (compression molding). The metal tube 11 is formed using a known swaging machine. Using a die, rolling is performed from the up-down direction or from the up-down, left-right direction, and by applying an impact load from the entire circumference. Unlike the wire drawing which is pulled in the axial direction, the metal tube and the titanium wire can be strongly adhered. The rolling is preferably performed 1 to 10 times until the original diameter is 0.7 times (about 25% area reduction) to 0.95 times (about 15% area reduction). If it is strongly rolled to less than 0.7 times, the titanium wire is broken, and if it is weakly rolled to a degree exceeding 0.95 times, there is a possibility that a deviation occurs between the titanium wire and the metal during wire drawing.

  In the wire drawing in the third step S3, the wire is drawn using a wire drawing die such as a round hole die, for example, about 1 to 60 times until the outer diameter becomes 0.03 to 0.3 times. As the lubricant to be used, a known lubricant such as “Koshin” containing molybdenum disulfide can be used. The coated wire 15 having a reduced diameter is obtained by drawing a single wire. If necessary, annealing may be performed after swaging, in the middle of swaging, or in the middle of wire drawing.

  Next, the coated wire rod 15 having a reduced diameter is annealed and softened at 500 to 800 ° C. for 1 to 10 minutes in the heat treatment step of the fourth step S4. This annealing is for softening the work hardening generated in the second step S2 and the third step S3. However, even if work hardening is performed during the focused drawing described later, the metal tube (outer layer) used in the focused drawing process is used. Material) It is necessary to soften to a degree that the hardness lower than 16 is maintained, specifically, to a degree satisfying [Tensile strength of titanium wire ≦ Tensile strength of the metal]. That is, since the coated wire 15 is always subjected to plastic processing in the radial direction and the axial direction by the small diameter processing, when the hardness of the coated wire 15 is higher than the hardness of the outer layer material 16, the elastic elongation increases relative to the plastic elongation. This is because a wire breakage occurs during the drawing process, making it impossible to produce a long product.

  For example, when the outer layer material 16 used in the converging wire drawing is a mild steel pipe, it is preferable to anneal in a furnace at 600 to 700 ° C. for about 3 to 8 minutes. If the annealing at this time is not sufficient and the titanium wire becomes harder than the metal tube, disconnection occurs in the middle. Further, when the annealing is excessive, the temperature exceeds 800 ° C., and the annealing time exceeds 10 minutes, an alloy of a metal tube and a titanium wire is generated, which is not preferable. For example, when using mild steel as the metal tube, it is preferable to suppress the formation of the Fe—Ti alloy layer by annealing at a low temperature for a short time as described above.

  In the fifth step S <b> 5, many annealed coated wire materials 15 are bundled and inserted into the outer layer material 16. The metal pipe used as the outer layer material 16 is a metal pipe that satisfies the [tensile strength of the coated wire ≦ the tensile strength of the metal], such as soft steel, aluminum, and stainless steel, similar to the coating material of the single wire. Use. The inner diameter of the outer layer material 16 varies depending on the number of the covered wire 15, but it is preferable that the bundle of the covered wire 15 can be inserted and that there is not much gap. The outer diameter of the outer layer material 16 is preferably about 1.0 to 1.5 times the inner diameter. This is because if the outer layer material 16 is too thick, the productivity is lowered, and if it is too thin, disconnection occurs, or titanium fibers cannot be separated from each other when melted with an acid.

  The outer layer material 16 into which the covered wire 15 is inserted is first swaged (sixth step S6). In the swaging process in the sixth step S6, similarly to the swaging process in the second step S2, a known swaging machine is used, and a shock is applied from the vertical direction or from the vertical and horizontal directions using a die. Roll. Rolling is performed 1 to 10 times until the original diameter becomes 0.75 (area reduction rate of about 25%) to 0.95 times (area reduction rate of about 15%), as in the case of single wire swaging. Is preferred. When the steel sheet is strongly rolled to less than 0.7 times, the titanium wire is broken, and in the case of weak rolling that exceeds 0.95 times, a deviation occurs between the titanium wire and the metal.

  Subsequently, the focused wire drawing is performed in the seventh step S7 of FIG. In the focused wire drawing process of the seventh step S7, the wire is drawn using a wire drawing die such as a round hole die about 15 to 60 times until the outer diameter becomes 0.03 to 0.1 times. As the lubricant to be used, a known lubricant such as “Koshin” containing molybdenum disulfide can be used. By focusing and drawing, the titanium wire is thinned to a desired thickness, for example, an equivalent circle diameter of 4 to 100 μm, more preferably an equivalent circle diameter of 15 μm or less. The wire is drawn until the length is 50 m or more, particularly 70 m or more.

  As shown in FIG. 3, the converging wire 18 provides a converging wire 18 in a state in which the titanium long fibers 17 having a small diameter are packed inside the coating material 14. The covering material 14 has almost no visible seam, but is processed into a substantially hexagonal shape. The titanium long fiber 17 is deformed from the original circular cross section and has irregularities on the surface, and has a substantially star shape. However, the upper and lower dimensions are substantially the same as the left and right dimensions, and the shape is inscribed in a substantially circular shape. It is.

  Next, an eighth step S8 is performed in which the obtained focusing line 18 is acid-treated. For the acid treatment, an acid that dissolves the single-layer coating material 14 and the outer layer material 16 of the focusing wire 18, and the alloy layer of titanium and the coating material 14 or the outer layer material 16 but does not dissolve the titanium long fibers 17 is used. When the covering material 14 and the outer layer material 16 are mild steel, an aqueous nitric acid solution (dilute nitric acid) diluted to 20 to 50% is used. However, sulfuric acid or dilute sulfuric acid can also be used. Nitric acid aqueous solution or the like is put in a dissolution tank, and a focusing line is sent to the dissolution tank and soaked in order. The soaking time is about 2 to 15 minutes, and then the separated bundle of titanium fibers is washed with water, dried and wound on a bobbin.

  When the covering material 14 and the outer layer material 16 are dissolved by the acid treatment, a titanium long fiber 17 as shown in FIG. 4 is obtained. Each of the titanium long fibers 17 has a circular or star-shaped cross-section with irregularities formed in the periphery of FIG. 3, extends in the axial direction with the same cross-sectional shape, and is drawn to 50 m or more, particularly 70 m or more. At this time, the surface shape is smooth in the length direction. The length of the titanium long fiber 17 is about 1000 m when the original titanium wire 10 has a length of 1000 mm and is stretched about 1000 to 10000 times by wire drawing or the like. Can do.

  Titanium long fiber 17 obtained by the above manufacturing method is close to the minimum diameter among the conventionally known titanium fiber thicknesses and is as long as 1000 m or more, and therefore, bundled long fibers or titanium fibers are entangled. It can be suitably used as a medical material as a web, non-woven fabric or woven fabric. In the case of an entangled web, it is possible to obtain a porous web having a desired three-dimensional structure by joining at an intersection by vacuum sintering or diffusion bonding. When a non-woven fabric or a woven fabric is used, only one piece may be used, or a multilayered form may be formed. In any case, it is possible to obtain a web, a nonwoven fabric, or a woven fabric having a large volume or area and high strength while being an extremely thin titanium long fiber.

  When titanium fibers are used for medical biocompatible implants and the like, the diameter of the titanium wire becomes longer as the diameter of the titanium wire is reduced, and the ends of the fibers in the implant are reduced. When titanium fibers are used for the implant, an inflammatory reaction is caused by the end portion. Therefore, it is preferable that the end portion is small, and it is most preferable if the implant can be covered with one titanium fiber. When a cell for living body culture (5 × 5 mm) made of a non-woven fabric of titanium fibers is formed by tangling one wire, a 76 m titanium wire is required if the outer diameter is 8 μm and the porosity is 87%. From this, it can be seen that a length of 70 m or more with a thin wire is preferable. Incidentally, when a titanium wire of about 100 μm is sufficient, a porosity of 87% is sufficient and 0.5 m is sufficient.

  Further, by twisting the titanium long fiber 17 immediately after melting, a twisted wire or wire of the titanium long fiber can be formed. In this case as well, since the fiber length is long, there is little risk of separation of fiber, and the tensile strength A high stranded wire can be obtained.

  Further, the titanium long fibers have irregularities on the surface in the cross-sectional shape, but are smooth in the longitudinal direction. Therefore, the fibers are slippery, and handling is easy when a large number of titanium long fibers are bundled, processed into a web, or processed into a woven or non-woven fabric. Further, since the cross-sectional shape is uniform, physical properties such as strength are substantially uniform over the longitudinal direction.

  FIG. 5 shows a rolling process (ninth step) in which the converging wire 18 is rolled from above and below by a die or a roller after the converging wire drawing process (seventh step S7) in FIG. 2 and before the acid treatment step (eighth step S8). The manufacturing method which performs process S9) is shown. In the case of FIG. 5, rolling is performed so that the width of the focusing line 20 is about 4 to 28 times the thickness. The rolling process is performed about twice. If rolling is performed until the width exceeds 28 times the thickness, there is a problem that cracking occurs or the titanium long fibers are disconnected.

  When the rolling process is performed in this manner, the respective covering materials 14 and the titanium long fibers 21 are also flattened as shown in FIG. Therefore, when the acid treatment step (eighth step 8) is performed, a long titanium fiber 21 having a flat cross section as shown in FIG. 7 can be obtained.

  The flat titanium long fibers 21 shown in FIG. 7 improve the cell fixing rate by strengthening the bonding force between titanium fibers or securing the surface area when processed into a web or made into a nonwoven fabric or woven fabric by vacuum sintering or diffusion bonding. There is an effect. Moreover, since it becomes flexible and can ensure a surface area also when making it a strand wire, there exists an effect which improves the fixing rate of a cell. In addition to webs, they can be bundled into medical materials such as artificial tooth roots and implants.

  In the case of FIG. 5, the case of simply rolling up and down was shown, but after flattening, for example, by further bending or rolling into a corrugated shape, etc., titanium fibers having various cross-sectional shapes are obtained after being dissolved with acid. be able to. Moreover, it can also be rolled into a curved shape or a wave shape from the beginning without rolling flatly. In either case, since it is used as a medical material, when it is processed into a web or the like, the three-dimensional structure becomes complicated, and the void ratio is increased.

[Example 1] A mild steel pipe having an outer diameter of 0.8 mm, a material: pure titanium, a titanium wire having a length of 1000 mm, an outer diameter of 3.4 mm, an inner diameter of 0.8 mm, and a carbon content of 0.089 wt% was prepared. The titanium wire was then inserted into a mild steel pipe and swaging was performed using a swaging machine. At this time, the titanium wire was reduced in diameter to 0.56 mm. After the swaging process, the tensile strength of the mild steel pipe was 656.5 N / mm ² and the tensile strength of the titanium wire was 696.3 N / mm ² . The obtained coated titanium wire was cold-drawn to an outer diameter of 0.273 mm using a drawing die (round hole die).

  The obtained coated wire was heat-treated (annealed) at 650 ° C. for 5 minutes. Further, 170 obtained coated wires were bundled and inserted into a mild steel pipe made of the same material as described above and having an outer diameter of 6.0 mm, an inner diameter of 4.0 mm, and a length of 2000 mm. The diameter was reduced to about 3.0 mm. Furthermore, it was drawn to an outer diameter of 0.71 mm by the same drawing process as described above. A photograph of the cross section of the obtained focusing line is shown in FIG. 8, and an enlarged photograph thereof is shown in FIG.

  Subsequently, the obtained focused line was dissolved in a 20% nitric acid aqueous solution, and the slightly formed Fe—Ti alloy layer and the outer mild steel were removed to obtain pure titanium long fibers having an outer diameter of about 8 μm. A micrograph of the obtained pure titanium long fiber is shown in FIG. The length of the pure titanium long fiber was 128 m. None of the pure titanium long fibers broke along the way.

  Example 2 A converging line was formed by the same method as in Example 1, and rolled so as to have a width of 1.853 mm and a thickness of 0.175 mm. FIG. 11 shows a cross section of the rolled focusing line, and FIG. 12 shows an enlarged photograph thereof. This was dissolved in the same nitric acid aqueous solution as in Example 1, and the mild steel was removed from the Fe—Ti alloy layer and the outer mild steel to obtain flat pure titanium long fibers having a width of about 10 μm and a thickness of about 2 μm. The length of the focused pure titanium long fiber was 134 m.

  [Comparative Example 1] Pure titanium filaments were prepared in the same manner as in Example 1 except that annealing was not performed. However, it was found that all of the obtained titanium long fibers were broken at about 15 to 20 m and could not be produced in a long length.

  [Comparative Example 2] Pure titanium filaments were prepared in the same manner as in Example 1 except that mild steel having an outer diameter of 0.9 mm and an inner diameter of 0.8 mm was used as the coating material. However, it was found that the obtained titanium long fibers had a length of about 5 to 15 m and were broken by 88% or more, and could not be produced long.

FIG. 1a is a partial process diagram showing an embodiment of a method for producing a titanium long fiber of the present invention, and FIG. 1b is a partial process diagram showing a change in cross-sectional shape by the process of FIG. 1a. FIG. 2a is a partial process diagram showing a post process of the process of FIG. 1a, and FIG. 2b is a partial process diagram showing a post process of FIG. 1b. It is an expanded sectional view of the focusing line obtained at the 6th process of FIG. FIG. 4 is an enlarged perspective view of a titanium long fiber after acid treatment of the focusing line in FIG. 3. It is a partial process figure which shows other embodiment of the manufacturing method of the titanium long fiber of this invention. It is an expanded sectional view of the flat converging line obtained at the 9th process of FIG. It is an expansion perspective view of the titanium long fiber after acid-treating the flat focusing line of FIG. It is a microscope picture which shows the cross section of the focusing line in the Example of this invention. It is a principal part enlarged micrograph of FIG. It is a microscope picture which shows one Example of the titanium long fiber of this invention. It is a microscope picture which shows the cross section of the focusing line in the other Example of this invention. It is a principal part enlarged micrograph of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Titanium wire 11 Metal tube 12 Titanium wire containing metal tube 13 Titanium thin wire 14 Coating material 15 Covering wire material 16 Outer layer material 17 Titanium long fiber 18 Focusing wire 20 Flat focusing wire 21 Flat titanium long fiber

Claims (16)

Titanium wire made of metal titanium or an alloy material mainly composed of metal titanium is coated with a coating material made of a metal having excellent malleability to reduce the diameter,
The obtained coated wire was annealed at 500 to 800 ° C. for 1 to 10 minutes,
Multiple annealed coated wires are bundled into a metal tube with excellent malleability,
Next, [Tensile strength of coated wire ≤ Tensile strength of metal tube]
The wire is drawn by 50m or more together with the metal tube,
Next, the metal tube and the coating material are dissolved and removed with an acid.
Production method of titanium long fiber.   The method for producing a titanium long fiber according to claim 1, wherein at the time of the wire drawing, the metal tube is drawn by 70 m or more.   The method for producing a titanium long fiber according to claim 1, wherein a plurality of the coated wires are bundled and placed in a metal tube, and before diameter drawing, the diameter is reduced to 15 to 25% by a swaging process.   2. The method for producing a titanium long fiber according to claim 1, wherein a plurality of coated wires are drawn together with the metal tube and then rolled into an irregular cross section before being melted with an acid. The step of coating the titanium wire with a coating material includes putting one titanium wire into a single-wire metal tube excellent in malleability,
Next,
[Tensile strength of titanium wire ≤ Tensile strength of the metal]
The method for producing a titanium continuous fiber according to claim 1, wherein the diameter is reduced by wire drawing so as to satisfy the above condition to obtain a coated wire.   A method for producing a coated wire, in which a single titanium wire is put into a single wire metal tube, then the diameter is reduced to 15 to 25% by a swaging process, and then the wire is drawn.   7. The method for producing a coated wire according to claim 6, wherein the outer diameter of the single wire metal tube is 2 to 6 times the outer diameter of the titanium wire.   A titanium long fiber having an equivalent circle diameter of 100 μm or less and a length of 20 m or more, produced by the production method according to claim 1.   The titanium continuous fiber according to claim 8, wherein the equivalent circle diameter is 15 µm or less and the length is 50 m or more.   The titanium long fiber according to claim 8, wherein the cross section is substantially polygonal and one side thereof is 15 µm or less.   9. The titanium long fiber according to claim 8, wherein the cross-sectional shape is a substantially star shape.   The titanium long fiber according to claim 8, which has a flat cross-sectional shape with a long side ratio of 2 to 8.5 times with respect to the short side 1.   The medical titanium long fiber according to claim 8, wherein the cross-sectional shape continues substantially constant in the length direction and the surface shape is smooth in the length direction.   The titanium long fiber according to any one of claims 8 to 13, wherein the titanium long fiber constitutes all or part of the cell culture carrier by entanglement or braiding.   The titanium long fiber according to any one of claims 8 to 13, wherein the titanium long fiber constitutes all or part of the biological tissue-derived scaffold by entanglement or braiding.   A titanium long fiber that constitutes the whole or a part of a biological tissue-derived scaffold by using one titanium long fiber according to any one of claims 8 to 13 and tangling or braiding it.