JP4339941B2 - Guide wire core material, guide wire, and manufacturing method thereof - Google Patents

Description

【００６２】
以上のように、芯材２を構成するＣｕ−Ａｌ−Ｍｎ基合金は、時効処理の加熱条件により、わずか数ｃｍの間隔で物性を変化させることが可能であり、テーパー加工を行うことなく、連続的に剛性と柔軟性をバランス良く配置することが可能であった。また、芯材２全体を同一組成の合金で一体化しており、トルク伝達性に優れている。
【００６３】
実施例２
図４に示す銅基合金線からなる芯材１２を用いたガイドワイヤー１１を製造した。芯材１２の基端部１３から先端部１４へ１２ａ（５００ｍｍ）、１２ｂ（１００ｍｍ）、１２ｃ（５０ｍｍ）、１２ｄ（５０ｍｍ）の四つの領域に対して、領域１２ａ、１２ｂでの直径は０．４ｍｍであり、先端部１４の直径が０．１ｍｍになるように１２ｃ部より先端部１４にかけてテーパー加工されている。芯材１２は下記の時効処理条件以外は実施例１と同じ方法で製造した。領域１２ａ：３００℃；領域１２ｂ：２５０℃；領域１２ｃ：２００℃；領域１２ｄ：１５０℃。時効処理時間は１５分間であった。これにより、基端部１３より先端部１４にかけて剛性が低下した。
【００６４】
得られた芯材１２にＡｕメッキを施した後、被覆層１５（造影剤として４０質量％硫酸バリウムを含有するポリアミド系エラストマー）にて外表面を被覆した。さらに、血管へ挿入時の潤滑性を増すために、被覆層１５の表面にさらにポリビニルピロリドンを主成分とする潤滑層１７を形成した。
【００６５】
実施例３
図５に示すガイドワイヤー２１を製造した。芯材２２の基端部２３より先端部２４へ２２ａ（５００ｍｍ）、２２ｂ（２００ｍｍ）、２２ｃ（５０ｍｍ）、２２ｄ（５０ｍｍ）の四つの領域に対して、領域２２ａ、２２ｂでの直径は０．４ｍｍであり、先端部２４の直径が０．１ｍｍになるように２２ｃ部より先端部２４にかけてテーパー加工されている。
【００６６】
下記の時効処理条件以外は実施例１と同じ方法で芯材２２を製造した。領域２２ａ：３００℃；領域２２ｂ：２５０℃；領域２２ｃ：２００℃；領域２２ｄ：１５０℃。時効処理時間は１５分間であった。これにより、基端部２３より先端部２４にかけて剛性が低下した。
【００６７】
得られた芯材２２のテーパー部を包接するようにコイル２６と接合し、先端部２４は血管壁を損傷しないようにプラズマ溶接にて成型された膨出部２７を形成した。さらに、芯材２２及びコイル２６にＡｕメッキを施した。芯材２２の外表面には、血管へ挿入時の潤滑性を増すために、ポリビニルピロリドンを主成分とする潤滑層（図示せず）を形成した。
【００６８】
実施例４
図６に示すガイドワイヤー３１の芯材３２は３本の銅基合金線の撚線からなる（図６のＡ−Ｂ断面図である図７を参照）。芯材３２の基端部３３より先端部３４に亘って、３２ａ（５００ｍｍ）、３２ｂ（１００ｍｍ）、３２ｃ（５０ｍｍ）の３ケ所毎に剛性が段階的に低くなるように形成されている。領域３２ａ、３２ｂでの芯材３２の直径は０．４ｍｍである。また、先端部３４における芯材３２の直径が０．１ｍｍになるように３２ｃ部の途中より先端部３４にかけてテーパー加工されている。先端部３４はプラズマ溶接にて、撚線がほどけないように、また先端部の造影性向上のために丸い膨張部３６を形成した。
【００６９】
芯材３２は下記の時効処理条件以外は実施例１と同じ方法で製造した。領域３２ａ：３００℃；領域３２ｂ：２５０℃；領域３２ｃ：２００℃。時効処理時間は１５分間であった。これにより、基端部３３より先端部３４にかけて剛性が低下した。
【００７０】
得られた芯材３２を被覆層３５（造影剤として４０質量％の硫酸バリウムを含有するポリアミド系エラストマー）にて被覆した。そして、血管へ挿入時の潤滑性を増すために、ポリメチルビニルエーテル−無水マレイン酸誘導体を主成分とする潤滑層（図示せず）を形成した。
【００７１】
【発明の効果】
以上に説明した通り、本発明のガイドワイヤーは傾斜機能を有する銅基合金からなるガイドワイヤー芯材を用いることにより、基端部に最適の弾性と剛性を、先端部に柔軟性を同時に設けることができるようになり、挿入操作、トルク伝達性に優れ、血管壁等に傷つけること無く、所定の部位に挿入することが可能となる。
【図面の簡単な説明】
【図１】本発明のガイドワイヤー用芯材の一実施例を示す概略図である。
【図２】本発明のガイドワイヤー用芯材のもう一実施例を示す概略図である。
【図３】本発明のガイドワイヤーの一実施例を示す概略図である。
【図４】本発明のガイドワイヤーのもう一実施例を示す拡大断面図である。
【図５】本発明のガイドワイヤーのその他の実施例を示す概略図である。
【図６】本発明のガイドワイヤーのその他の実施例を示す拡大断面図である。
【図７】図６のＡ−Ｂ断面図である。
【符号の説明】
１１、２１、３１・・・・・・・・ガイドワイヤー
２、１２、２２、３２、５２・・・芯材
３、１３、２３、３３、５３・・・基端部
４、１４、２３、３４、５４・・・先端部
１５、２５、３５・・・・・・・・被覆層
１７、２７、３７・・・・・・・・潤滑層
５１・・・・・・・・・・・・・・線材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a guide wire used when a catheter is introduced and placed at a predetermined site such as a blood vessel for treatment and examination.
[0002]
[Prior art and problems to be solved by the invention]
In order to introduce and place a catheter in a blood vessel or the like, first, a guide wire is introduced as a guide to a target site, and then the catheter is introduced into a target site using the guide wire as an axis. Because the blood vessels of the human body are curved and branched, and there are individual differences, it has high insertion operability and torque transmission in order to insert a guide wire without any trouble without damaging the blood vessels and blood vessel walls. A guide wire is required.
[0003]
For this reason, a core material with a reduced diameter, flexible tip and a somewhat rigid end is coated with a synthetic resin that is unlikely to damage the living body, such as polyamide, thermoplastic polyurethane, or fluorine resin. Have been used.
[0004]
Coiled metal wires made of stainless steel, carbon steel, etc. are used as guidewires, but they are easy to bend, so recently, guidewires with superelastic metals such as Ni-Ti alloys as the core material. Are also widely used (Japanese Patent Publication No. 2-2549).
[0005]
However, the superelastic Ni—Ti alloy exhibits good flexibility, but lacks a sense of rigidity. Therefore, there are cases where the insertion operation into the blood vessel is not successful and it is difficult to insert it into a desired site in the body.
[0006]
In addition, Ni-Ti alloys are not so good in cold workability, are difficult to be thinned, and there is a problem that the inclination of physical properties by heat treatment is not as inclined as the control of the torque transmission of the guide wire.
[0007]
Accordingly, an object of the present invention is to provide a guide wire core having flexibility at the distal end portion, maintaining appropriate elasticity and rigidity at the proximal end portion, excellent in insertion operability and torque transmission property, and excellent workability. It is to provide a material and a guide wire using the material.
[0008]
[Means for Solving the Problems]
As a result of intensive studies in view of the above problems, the present inventors have found that by using a Cu-Al-Mn base shape memory alloy, the tip portion can be provided with appropriate flexibility, and Cu-Al- By utilizing the characteristics of the gradient function in which the characteristics of the Mn-based alloy gradually change, the rigidity of the guide wire core can be gradually changed, and the guide wire has remarkably excellent insertion operability and torque transmission. The present invention has been completed.
[0009]
That guidewire core material of the present invention, the base end portion in high rigidity, a guide core wire is less rigid than the proximal end tip portion also small greens rather 5-20 % by weight of Mn, 3 to 10% by weight of Al, copper-based alloy wire der consisting of balance Cu and unavoidable impurities is, the low rigid end portion having a crystal structure consisting essentially of β single phase, substantially And located between the low-rigid end and the high-rigid end having a crystal structure consisting of two phases of an α phase and a Heusler phase, and from the crystal structure of the low-rigid end. It has the middle part which changes to the crystal structure of a rigid end part continuously or in steps .
[0010]
In the guide wire core material according to the present invention, the copper-based alloy wire further includes Ni, Co, Fe, Ti, V, Cr, Si, Nb, Mo, Sn, Ag, W, Mg, P, Zr, Zn, B In addition, one or two or more selected from the group consisting of misch metal may be contained in a total amount of 0.001 to 10 % by mass .
[0011]
(Delete)
[0012]
The copper-based alloy wire is formed by hot working and / or cold working, is kept at a temperature of 500 ° C. or higher, is rapidly cooled, and is further subjected to aging treatment. The low-rigid end is less than 250 ° C. at 250 to 350 ° C., and the space between the high-rigid end and the low-rigid end is from the heating temperature of the high-rigid end to the heating temperature of the low-rigid end. The temperature is preferably changed continuously or stepwise.
[0013]
The guide wire of this invention has the said core material for guide wires, It is characterized by the above-mentioned.
[0014]
In the guide wire of the present invention, the guide wire core material is preferably coated with any of Au, Pt, Ti, Pd, and TiN. Moreover, it is preferable that at least a part of the guide wire core material is covered with a synthetic resin.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
[1] Copper-based alloy wire
(1) Composition of copper-based alloy wire used in the present invention copper-based alloy wire, Al3～10 mass%, include Mn5~20 mass%, the balance being Cu and inevitable impurities. This copper-based alloy produces a β (bcc structure) single phase at a high temperature and a martensite (non-diffusion) transformation at a low temperature. Further, the β single-phase structure changes into a two-phase structure of an α phase (fcc structure) and a Heusler phase (regular bcc structure) by heat treatment at around 300 ° C.
[0016]
If the content of Al element is less than 3 % by mass , a β single phase cannot be formed, and if it exceeds 10 % by mass , it becomes extremely brittle. Although the content of Al element varies depending on the composition of Mn element, the preferable content of Al element is 6 to 10 % by mass .
[0017]
By containing Mn element, the existence range of β phase is expanded to the low Al side, the cold workability is remarkably enhanced, and the production is facilitated. If the amount of Mn element added is less than 5 % by mass , satisfactory processability cannot be obtained, and a β single phase region cannot be formed. If the amount of Mn element added exceeds 20 % by mass , superelasticity cannot be obtained, which is not preferable. A preferable Mn content is 8 to 12 % by mass .
[0018]
The Cu-based alloy having the above composition is rich in hot workability and cold workability, and can be processed at a work rate of 20% to 90% or more in the cold state, and can be easily formed into a fine wire or the like.
[0019]
In addition to the above components, the copper-based alloy wire of the present invention further includes Ni, Co, Fe, Ti, V, Cr, Si, Nb, Mo, W, Sn, Ag, Mg, P, Zr, Zn, B, and Misch. One or two or more selected from the group consisting of metals can be contained. Is preferably the content of these elements is from 001 to 10% by weight 0.1 in total, in particular 0.001 to 2% by mass. These elements exhibit the effect of increasing the strength of the copper-based alloy wire by refining crystal grains while maintaining cold workability. However, if the content of these elements exceeds 10 % by mass , the martensitic transformation temperature is lowered and the β single-phase structure becomes unstable.
[0020]
Ni, Co, Fe, Sn, and Ag are effective elements for strengthening the base structure. Preferable contents of Ni, Fe and Ag are 0.001 to 3 % by mass , respectively. Co also refines crystal grains by forming CoAl, but when it is excessive, toughness is reduced. The preferable content of Co is 0.001 to 2 % by mass . The preferable content of Sn is 0.001 to 1 % by mass .
[0021]
Ti combines with inhibitory elements N and O to form oxynitrides. Moreover, a boride is formed by compound addition with B, a crystal grain is refined | miniaturized and a shape recovery rate is improved. A preferable content of Ti is 0.001 to 2 % by mass .
[0022]
V, Nb, Mo and Zr have the effect of increasing the hardness, improve the wear resistance, and since these elements hardly dissolve in the matrix, they precipitate as bcc crystals and are effective in refining crystal grains Element. The preferred contents of V, Nb, Mo and Zr are 0.001 to 1 % by mass , respectively.
[0023]
Cr is an effective element for maintaining wear resistance and corrosion resistance. A preferable content of Cr is 0.001 to 2 % by mass .
[0024]
Si has the effect of improving the corrosion resistance. A preferable content of Si is 0.001 to 2 % by mass .
[0025]
Since W hardly dissolves in the base, there is an effect of precipitation strengthening. A preferable content of W is 0.001 to 1 % by mass .
[0026]
Mg removes the inhibitory elements N and O and fixes the inhibitory element S as a sulfide, which is effective in improving hot workability and toughness, but a large amount of addition causes grain boundary segregation, Causes embrittlement. The preferable content of Mg is 0.001 to 0.5 mass% .
[0027]
P is used as a deoxidizer and has an effect of improving toughness. The preferable content of P is 0.01 to 0.5 % by mass .
[0028]
Zn has the effect of lowering the shape memory processing temperature. The preferable content of Zn is 0.001 to 5 % by mass .
[0029]
B has an effect of refining the crystal structure. In particular, combined addition with Ti and Zr is preferable. A preferable content of B is 0.01 to 0.5 % by mass .
[0030]
Misch metal has the effect of refining crystal grains. The preferred content of misch metal is 0.001 to 2 mass% .
[0031]
(2) Manufacturing method of copper base alloy wire
(a) Forming a copper-based alloy wire A copper-based alloy having the above composition is melt-cast and formed into a wire of a desired size by hot rolling, cold rolling, drawing or the like. Moreover, the front-end | tip part of a copper base alloy wire can be processed into a taper by a well-known method. The copper-based alloy having the composition of the present invention is rich in hot workability and cold workability, can be processed at a cold work rate of 20% to 90% or more, and can be easily formed into a fine wire or the like. Can do.
[0032]
(b) Solution treatment Next, heating is performed at a temperature of 500 ° C. or higher, preferably 600 to 900 ° C., to transform the crystal structure into a β single phase. After the heat treatment, the β single phase state is frozen by rapidly cooling at a rate of 50 ° C./second or more. Rapid cooling is performed in a coolant such as water or forced air cooling. When the cooling rate is less than 50 ° C./second, α phase precipitation occurs, so that the β single phase crystal structure cannot be maintained, and the functional gradient becomes small. A preferable cooling rate is 200 ° C./second or more.
[0033]
(c) Aging treatment
Depending on the manner of aging treatment , the copper-based alloy wire can be made into the following two forms. In the first embodiment, the entire copper-based alloy wire has shape memory characteristics and superelastic characteristics uniformly. In the second form, the copper-based alloy wire has a high-rigid end and a low-rigid end, and the rigidity decreases continuously or stepwise from the high-rigid end to the low-rigid end.
[0034]
(i) First Form In the case of the first form, the copper-based alloy wire is subjected to an aging treatment at a temperature of 200 ° C. or lower, preferably 100 to 200 ° C. If the heating temperature of the low-rigid end is too low, the β-phase regularity is not perfect, and the martensitic transformation temperature may change if left at room temperature. On the other hand, if the heating temperature exceeds 200 ° C., precipitation of α phase occurs and rigidity increases.
[0035]
The aging treatment time varies depending on the composition of the copper-based alloy wire, but is preferably 1 to 300 minutes, particularly preferably 5 to 200 minutes. If the aging treatment time is less than 1 minute, the aging effect cannot be obtained, and if the aging treatment time exceeds 300 minutes, the decomposition starts and the shape memory characteristics deteriorate.
[0036]
The copper-based alloy wire of the first form has a crystal structure substantially consisting of a β single phase, and has a shape memory characteristic and is a superelastic material as previously reported (Japanese Patent Laid-Open No. 7-62472). The hardness of the copper-based alloy wire of the first form is less than 350 Hv, and the yield stress (that is, 0.2% proof stress) varies depending on the alloy composition, but is less than 400 MPa. The shape recovery rate is 80% or more.
[0037]
(ii) Second form The second form is a functionally gradient material as described in Japanese Patent Application No. 10-181268. In the case of the second embodiment, the low-rigid end aging treatment is performed at a temperature of less than 250 ° C., and the high-rigid end aging treatment is performed at a temperature of 250 to 350 ° C. The middle part located between the low-rigid end and the high-rigid end is aged with a temperature distribution (temperature gradient) that changes continuously or stepwise from the heating temperature of the low-rigid end to the heating temperature of the high-rigid end. Process.
[0038]
If the heating temperature of the low-rigid end is too low, the β phase is unstable, and if left at room temperature, the martensitic transformation temperature may change. On the other hand, when the heating temperature is 250 ° C. or higher, the α phase is precipitated, and the difference in functional characteristics from the high-rigidity end portion is reduced. The heating temperature of the low-rigid end is preferably 100 to 200 ° C.
[0039]
If the heating temperature of the high-rigidity end is less than 250 ° C., the crystal structure of the high-rigidity end cannot be sufficiently transformed into two phases of α phase and Heusler phase, and the difference in functional characteristics from the low-rigidity end is small. Become. On the other hand, when the heating temperature exceeds 350 ° C., the structure becomes coarse and functional characteristics such as yield strength and hardness are deteriorated. The heating temperature of the high-rigid end is preferably 280 to 320 ° C.
[0040]
The difference between the heating temperature of the low-rigid end and the heating temperature of the high-rigid end is preferably 50 ° C. or higher, and particularly preferably 80 ° C. or higher. If the difference between the heating temperature at the low-rigid end and the heating temperature at the high-rigid end is less than 50 ° C., the difference in rigidity between the two portions becomes small.
[0041]
The aging treatment time varies depending on the composition of the copper-based alloy wire, but is preferably 1 to 300 minutes, particularly preferably 5 to 200 minutes. If the aging treatment time is less than 1 minute, the aging effect cannot be obtained, and if the aging treatment time exceeds 300 minutes, the structure becomes coarse and the mechanical properties as a material become insufficient.
[0042]
The copper-based alloy wire of the second form thus obtained is a functionally graded alloy as described previously (Japanese Patent Application No. 10-181268), and has a low-rigid end having a crystal structure substantially consisting of a β single phase. , A high-rigid end substantially consisting of two phases of an α phase and a Heusler phase, and the low-rigid end to the high-rigid end located between the low-rigid end and the high-rigid end It consists of an intermediate part whose crystal structure changes continuously or stepwise.
[0043]
In the present invention, “the crystal structure is substantially composed of a β single phase” means that the crystal structure is not only a β phase but also a small amount of α phase and Heusler phase, and a small amount of TiB, ZrB, bcc phase V, Mo. , Nb, W, and the case of having an intermetallic compound such as NiAl, CoAl. The ratio of the α phase and the Heusler phase is preferably 5% by volume or less in total. If the sum of the proportions of the α phase and the Heusler phase exceeds 5% by volume, the superelasticity and shape recoverability of the low-rigid end portion are remarkably lowered, and the functional characteristic gradient is reduced, which is not preferable.
[0044]
On the other hand, “the crystal structure is substantially composed of two phases of α phase and Heusler phase” not only means that the crystal structure is composed only of α phase and Heusler phase, but also a small amount of β phase and a small amount of TiB, ZrB. Including the case of containing an intermetallic compound such as V, Mo, Nb, W of bcc phase, NiAl, CoAl or the like. The proportion of β phase is preferably 10% by volume or less.
[0045]
In addition, “the crystal structure changes continuously or stepwise” means that the proportion of β phase in the structure and the proportion of α phase and Heusler phase change continuously or stepwise. . The aging treatment gradually precipitates the α phase and the Heusler phase from the β phase, and the higher the aging treatment temperature and the longer the aging treatment time, the larger the proportion of the precipitated α phase and Heusler phase. Whether the change of the crystal structure is continuous or stepwise is determined by the temperature distribution during the aging treatment and the setting of the treatment time. If the aging treatment is performed in a short time with a stepwise temperature distribution, the crystal structure changes stepwise.
[0046]
As described in JP-A-7-62472, the low-rigid end portion composed of β single phase has shape memory characteristics and superelasticity. On the other hand, the high-rigid end is a hard material that is difficult to bend and has completely different functional characteristics from the low-rigid end. In the third portion, there is a continuous or stepwise change from the functional characteristic of the low-rigid end to the functional characteristic of the high-rigid end.
[0047]
The length of the low-rigid end portion, the length of the high-rigid end portion, and the rigidity change pattern in the intermediate portion can be arbitrarily set according to the distribution of the heating temperature during the aging treatment.
[0048]
When comparing the characteristics of the low-rigid end and the high-rigid end, the hardness of the low-rigid end and the hardness of the high-rigid end vary depending on the alloy composition, but the hardness of the low-rigid end is less than 350 Hv, The difference in hardness between the low rigidity end and the high rigidity end is 20 Hv or more. The low-rigid end portion is a superelastic material, and its yield stress (that is, 0.2% proof stress) varies depending on the alloy composition, but is less than 400 MPa. The difference in yield stress between the low-rigid end and the high-rigid end is 50 MPa or more. Further, the low-rigid end portion is a shape memory material, and the shape recovery rate is 80% or more. On the other hand, the shape recovery rate of the highly rigid end portion is less than 15%, and there is almost no shape memory characteristic. The difference in the shape recovery rate between the low-rigid end and the high-rigid end is 70% or more.
[0049]
[2] Core material for guide wire The base end portion of the core material for guide wire of the present invention has high rigidity, and the distal end portion has lower rigidity than the base end portion. Among them, some even a few greens rather is a copper-based alloy wire. Further, at least the tip portion of the copper-based alloy wire has superelasticity. Hereinafter, the core material for a guide wire of the present invention will be described with specific examples, but the present invention is not limited thereto.
[0050]
(1) First Aspect A first aspect of the core material for a guide wire of the present invention shown in FIG. 1 is composed of a straight copper-based alloy wire, and the tip portion is not tapered. The region is divided into four regions 2a, 2b, 2c, and 2d in order from the base end portion 3 to the tip end portion 4, and the rigidity in each region is gradually decreased from the base end portion 3 to the tip end portion 4. Yes. The length of each region can be arbitrarily set as desired.
[0051]
As described above, the core material having such a slanted rigidity is formed by hot working and / or cold working, kept at a temperature of 500 ° C. or higher, rapidly cooled, and further manufactured by aging treatment. Different heating temperatures are applied to the respective regions during the aging treatment. The aging treatment temperature in the region 2a is preferably 250 to 350 ° C. Further, the aging treatment temperature of the region 2d is preferably less than 250 ° C. The aging treatment temperature in the regions 2b and 2c is an intermediate aging treatment temperature between the region 2a and the region 2d, and the aging treatment temperature in the region 2b is higher than that in the region 2c.
[0052]
(2) Second Aspect The second aspect of the core material for a guide wire of the present invention shown in FIG. 2 is composed of a copper-based alloy wire. The region is divided into four regions 2a, 2b, 2c, and 2d in order from the proximal end 3 to the distal end portion 4, and is tapered from the region 2c toward the distal end portion 4 to be reduced in diameter. The rigidity in each region is gradually decreased from the base end portion 3 to the tip end portion 4. The length of each region can be arbitrarily set as desired.
[0053]
As in the first embodiment, the region 2a is a high-rigidity region, and the region 2d is low-rigidity and a superelastic region. The regions 2b and 2c have intermediate rigidity between the region 2a and the region 2d, and the region 2b has higher rigidity than the region 2c. However, since the tip portion 4 has a diameter smaller than that of the first mode, the flexibility of the region 2d is higher than that of the first mode. The core material of the second aspect can be produced under the conditions described in the first aspect.
[0054]
(3) Third Embodiment The guide wire of the present invention shown in FIG. 3 is formed by joining a wire 51 and a core 52. The core material 52 is made of a copper-based alloy wire, and the wire material 51 is a flat ribbon wire made of a known material such as stainless steel. The wire 51 and the core material 52 are overlapped and joined by a coil or the like.
[0055]
The core material 52 is divided into two regions 52 a and 52 b in order from the base end portion 53 to the tip end portion 54. The region 52a is a high-rigidity region, and the region 52b has a rigidity that decreases continuously in the direction of the distal end portion 54. The vicinity of the front end portion 54 of the core material 52 is low-rigidity and superelastic. In addition, the length of each area | region can be arbitrarily set as desired.
[0056]
As in the first embodiment, the rigidity of the core member 52 can be inclined by applying different heating temperatures to the respective regions during the aging treatment. The aging treatment temperature in the region 52a is preferably 250 to 350 ° C. In addition, the aging treatment of the region 52b is performed with a temperature distribution that continuously decreases from the direction of the proximal end portion 53 toward the distal end portion 54. The maximum temperature of the temperature distribution is the same aging treatment temperature as that of the region 52a, and the minimum temperature at the tip 54 is preferably less than 250 ° C.
[0057]
[3] Guide wire The guide wire of the present invention has the guide wire core material. In the present invention, it is preferable to coat Au, Pt, Ti, Pd, TiN by plating, vapor deposition or the like, whether or not the guide wire core is coated with a resin by a known method. Moreover, it is preferable to coat the core material for the guide wire with polyethylene, polyvinyl chloride, polyester, polypropylene, polyamide, polyurethane, polystyrene, fluororesin, silicon rubber, or an elastomer thereof and a composite material. These coating materials preferably contain a contrast agent such as barium sulfate. Furthermore, it is preferable to coat the surface of the guide wire with a lubricating material such as polyvinyl pyrrolidone, maleic anhydride ethyl ester, methyl vinyl ether maleic anhydride copolymer.
[0058]
【Example】
Example 1
A guide wire core material 2 (hereinafter referred to as “core material 2”) made of a copper-based alloy wire shown in FIG. 1 was produced by the following method. The total length of the core material 2 is 1200 mm, and the tip portion 4 is not tapered.
[0059]
First, a copper base alloy composed of Al 7.5 % by mass , Mn 9.9 % by mass , Ni 2.0 % by mass , and Cu 80.6 % by mass is melted and solidified at an average cooling rate of 140 ° C./min. Thus, a wire having a diameter of 0.4 mm was obtained. Thereafter, the core material 2 was heat-treated at 900 ° C. for 10 minutes and quenched in ice water.
[0060]
After this core material 2 is cut to 1200 mm, the end 2 a (600 mm), 2 b (300 mm), 2 c (200 mm), 2 d (100 mm) is formed from the end on the side that becomes the base end 3 to the end on the tip 4 side. ) Was subjected to aging treatment for 15 minutes under the following temperature conditions. Region 2a: 300 ° C; Region 2b: 250 ° C; Region 2c: 200 ° C; Region 2d: 150 ° C. Thereby, rigidity fell from the base end part 3 to the front-end | tip part 4. As shown in FIG. The hardness of each region was measured with a micro Vickers hardness meter. The results are shown in Table 1.
[0061]
Table 1 Hardness distribution

[0062]
As described above, the Cu—Al—Mn base alloy constituting the core material 2 can change the physical properties at intervals of only a few cm depending on the heating conditions of the aging treatment, without performing taper processing. It was possible to continuously arrange rigidity and flexibility in a good balance. Further, the entire core material 2 is integrated with an alloy having the same composition, and the torque transmission is excellent.
[0063]
Example 2
A guide wire 11 using a core material 12 made of a copper-based alloy wire shown in FIG. 4 was manufactured. For the four regions 12a (500mm), 12b (100mm), 12c (50mm), and 12d (50mm) from the base end portion 13 to the distal end portion 14 of the core material 12, the diameters in the regions 12a and 12b are 0. It is 4 mm, and is tapered from the 12c portion to the tip portion 14 so that the diameter of the tip portion 14 becomes 0.1 mm. The core material 12 was manufactured by the same method as Example 1 except the following aging treatment conditions. Region 12a: 300 ° C; Region 12b: 250 ° C; Region 12c: 200 ° C; Region 12d: 150 ° C. The aging treatment time was 15 minutes. Thereby, the rigidity decreased from the base end portion 13 to the tip end portion 14.
[0064]
The obtained core material 12 was subjected to Au plating, and then the outer surface was coated with a coating layer 15 (polyamide elastomer containing 40 % by mass of barium sulfate as a contrast agent). Furthermore, in order to increase the lubricity at the time of insertion into the blood vessel, a lubrication layer 17 mainly composed of polyvinylpyrrolidone was formed on the surface of the coating layer 15.
[0065]
Example 3
A guide wire 21 shown in FIG. 5 was manufactured. For the four regions 22a (500 mm), 22b (200 mm), 22c (50 mm), and 22d (50 mm) from the base end portion 23 of the core member 22 to the distal end portion 24, the diameters in the regions 22a and 22b are 0. It is 4 mm, and is tapered from the 22c portion to the tip portion 24 so that the diameter of the tip portion 24 becomes 0.1 mm.
[0066]
The core material 22 was manufactured by the same method as Example 1 except the following aging treatment conditions. Region 22a: 300 ° C .; region 22b: 250 ° C .; region 22c: 200 ° C .; region 22d: 150 ° C. The aging treatment time was 15 minutes. Thereby, the rigidity decreased from the base end portion 23 to the tip end portion 24.
[0067]
The taper part of the obtained core material 22 was joined to the coil 26 so as to enclose it, and the tip part 24 formed a bulging part 27 molded by plasma welding so as not to damage the blood vessel wall. Further, the core material 22 and the coil 26 were plated with Au. On the outer surface of the core material 22, a lubricating layer (not shown) mainly composed of polyvinylpyrrolidone was formed in order to increase lubricity when inserted into a blood vessel.
[0068]
Example 4
The core material 32 of the guide wire 31 shown in FIG. 6 consists of the twisted wire of three copper base alloy wires (refer FIG. 7 which is AB sectional drawing of FIG. 6). From the base end portion 33 to the tip end portion 34 of the core member 32, the rigidity is gradually reduced at every three positions 32a (500 mm), 32b (100 mm), and 32c (50 mm). The diameter of the core material 32 in the regions 32a and 32b is 0.4 mm. In addition, the tip 32 is tapered from the middle of the portion 32c to the tip 34 so that the diameter of the core member 32 is 0.1 mm. The distal end portion 34 is formed by a round welding portion 36 by plasma welding so as not to unwind the twisted wire and to improve the contrast of the distal end portion.
[0069]
The core material 32 was manufactured by the same method as Example 1 except the following aging treatment conditions. Region 32a: 300 ° C .; region 32b: 250 ° C . ; region 32c: 200 ° C. The aging treatment time was 15 minutes. Thereby, the rigidity decreased from the base end portion 33 to the tip end portion 34.
[0070]
The obtained core material 32 was covered with a coating layer 35 (polyamide-based elastomer containing 40 % by mass of barium sulfate as a contrast agent). And in order to increase the lubricity at the time of insertion in the blood vessel, the lubricating layer (not shown) which has a polymethyl vinyl ether-maleic anhydride derivative as a main component was formed.
[0071]
【The invention's effect】
As described above, the guide wire of the present invention uses the guide wire core material made of a copper-based alloy having a tilting function, so that the base end portion is provided with optimum elasticity and rigidity and the tip portion is simultaneously provided with flexibility. Thus, the insertion operation and the torque transmission property are excellent, and it is possible to insert into a predetermined part without damaging the blood vessel wall or the like.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a core material for a guide wire according to the present invention.
FIG. 2 is a schematic view showing another embodiment of the core material for a guide wire of the present invention.
FIG. 3 is a schematic view showing an embodiment of the guide wire of the present invention.
FIG. 4 is an enlarged sectional view showing another embodiment of the guide wire of the present invention.
FIG. 5 is a schematic view showing another embodiment of the guide wire of the present invention.
FIG. 6 is an enlarged sectional view showing another embodiment of the guide wire according to the present invention.
7 is a cross-sectional view taken along the line AB of FIG.
[Explanation of symbols]
11, 21, 31... Guide wire 2, 12, 22, 32, 52... Core material 3, 13, 23, 33, 53 ... Base end portion 4, 14, 23, 34, 54 ... tip portions 15, 25, 35 ... coating layers 17, 27, 37 ... lubrication layer 51 ... ···wire

Claims (7)

The proximal end with high rigidity, Ri low rigidity der than tip the proximal portion, the rigidity toward the lower rigid end portion from the high rigid end portion continuously or stepwise decreasing guidewire wick a timber, low Na rather and the even part of 5 to 20 wt% Mn, 3 to 10% by weight of Al, Ri Do and a balance Cu and unavoidable impurities, consists essentially of β single-phase crystal structure Between the low-rigid end and the high-rigid end, the low-rigid end having a crystal structure substantially consisting of two phases of α phase and Heusler phase, A core material for a guide wire, comprising a copper-based alloy wire having an intermediate portion that changes continuously or stepwise from a crystal structure of a low-rigid end portion to a crystal structure of the high-rigid end portion .  2. The guide wire core according to claim 1, wherein the copper-based alloy wire further includes Ni, Co, Fe, Ti, V, Cr, Si, Nb, Mo, Sn, Ag, W, Mg, P, Zr, A core material for a guide wire comprising 0.001 to 10% by weight in total of one or more selected from the group consisting of Zn, B and Misch metal.  The core material for a guide wire according to claim 1 or 2, wherein the copper-based alloy wire is formed by hot working and cold working, kept at a temperature of 500 ° C or higher, rapidly cooled, and further obtained by aging treatment. The aging temperature is 250 to 350 ° C. at the high-rigid end, the low-rigid end is less than 250 ° C., and the high-rigid end is between the high-rigid end and the low-rigid end. A core material for a guide wire, characterized in that the temperature is changed continuously or stepwise from the heating temperature to the heating temperature of the low-rigid end. A guide wire comprising the guide wire core material according to claim 1 . The guide wire according to claim 4, wherein the guide wire core material is coated with any one of Au, Pt, Ti, Pd, and TiN. 6. The guide wire according to claim 4 , wherein at least a part of the guide wire core material is covered with a synthetic resin. The guide wire core material has a base end portion having high rigidity, a tip end portion having lower rigidity than the base end portion, and the rigidity decreasing continuously or stepwise from the high rigidity end portion toward the low rigidity end portion. A copper-based alloy wire comprising 5 to 20% by mass of Mn, 3 to 10% by mass of Al, the remaining Cu and inevitable impurities is formed by hot working and / or cold working. And, after being held at a temperature of 500 ° C. or higher, rapidly cooled, and subjected to aging treatment at 250 to 350 ° C. to form the highly rigid end portion having a crystal structure substantially composed of two phases of α phase and Heusler phase, The low-rigid end portion having a crystal structure substantially consisting of a β single phase is formed by aging treatment at less than 250 ° C., and the high-rigid end portion is interposed between the high-rigid end portion and the low-rigid end portion. From the heating temperature to the heating temperature of the low-rigid end Forming an intermediate portion that changes continuously or stepwise from the crystal structure of the low-rigid end portion to the crystal structure of the high-rigid end portion by performing an aging treatment at a temperature that is changed in a stepwise manner.

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