JP2002069556A - TiNiAu BASED ALLOY MATERIAL HAVING EXCELLENT SUITABILITY FOR THE HUMAN BODY AND MEMBER FOR MEDICAL APPLIANCE USING THE SAME - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop an alloy material suitable for use over a long period of time in the human body, i.e., a TiNi based alloy material having superelasticity and shape memory characteristics and also having the controllability of the elution of Ni ions. SOLUTION: In this TiNiAu base alloy material having excellent suitability for the human body, as for the alloy composition, in the three-dimensional compositional figure of Ti, Au and Ni, Ti, Au and Ni have specified compositions in a region decided by a quadrilateral having a first vertex (the A point in the figure 2), a second vertex (the B point in the figure 2), a third vertex (the C point in the figure 2) and a fourth vertex (the D point in the figure 2), and also, the crystal grain size in the structure of the alloy material is controlled to <=200 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a TiNiAu alloy having shape memory and superelastic properties and excellent biocompatibility used for medical equipment and the like, and a medical equipment member using the same. is there. In the present invention, T
The iNiAu-based alloy material is a TiNiAu alloy material and this alloy material further includes Co, Cr, Cu, Fe, Hf, Mn, M
It means a TiNiAu-based alloy material in which one or more of o, Nb, Pd, Pt, and Zr are selectively added.

[0002]

2. Description of the Related Art In recent years, various attempts have been made to apply alloy materials having shape memory and superelastic properties to the medical field. Among them, TiNi-based alloys are used for members for medical equipment, such as orthodontic wires, implants, catheters, and guide wires, because of their excellent corrosion resistance and good compatibility with living bodies.

[0003]

When used as an implant intended for use in a human or animal body, corrosion resistance over a long period of time is required, and TiNi-based alloys are associated with some people who are allergic to Ni. There is a concern about elution of the Ni element.

Therefore, an object of the present invention is to improve corrosion resistance,
In particular, it is an object of the present invention to provide a biological alloy material in which elution of Ni ions is suppressed as much as possible, that is, excellent in biocompatibility. It is another object of the present invention to provide an alloy material having improved shape compatibility and superelasticity while improving biocompatibility.

[0005]

According to a first aspect of the present invention, there is provided a fuel cell system comprising: an alloy comprising Ti, Au and Ni.
In the ternary composition diagram of Ti, 49.0 at% of Ti, Au2.
The first vertex at 0 at% and Ni49.0 at% (point A in FIG. 2), the second vertex at Ti 50.5 at%, Au 2.0 at% and Ni 47.5 at% (B in FIG. 2)
Point), the third vertex at Ti 50.5 at%, Au 15.0 at% and Ni 34.5 at% (point C in FIG. 2), T
i49.0at%, Au15.0at% and Ni3
It is necessary to have an alloy composition within a region defined by a quadrilateral having a fourth vertex (point D in FIG. 2) at 6.0 at%, and to set the crystal grain size of the structure of the alloy material to 200 μm or less. It is a feature.

Incidentally, the alloy composition of the present invention is shown in FIG. 1 and FIG. 2 in a ternary composition diagram of Ti, Au and Ni.
FIG. 1 shows an outline of this range, and FIG. 2 is an enlarged view of this range. The alloy composition range of the present invention is within a region defined by a quadrilateral having first to fourth vertices, and the parentheses after each of the vertices correspond to the corresponding symbols in FIG. A point, B point, C point, ... J point,
K point) (claims 2 to be described below).
The same applies to the invention of No. 4).

Further, according to the invention of claim 2, within the scope of claim 1, the first vertex located at 49.0 at% of Ti, 6.0 at% of Au and 45.0 at% of Ni (E in FIG. 2)
Point), 49.8 at% of Ti, 6.0 at% of Au and N
i The second vertex at 44.2 at% (point F in FIG. 2), Ti
49.8 at%, Au 7.0 at%, and Ni 43.2
Third vertex at at% (point G in FIG. 2), Ti49.0a
The composition is in a region defined by a quadrilateral having a fourth vertex (point H in FIG. 2) at t%, Au11.0 at%, and Ni40.0 at%, and has excellent superelastic properties and suppression of elution of Ni ions. The TiNiAu-based alloy material having excellent biocompatibility according to claim 1, wherein the TiNiAu-based alloy material has a property.

According to a third aspect of the present invention, there is provided a method according to the first aspect, wherein Ti is 49.0 at%, Au is 6.0 at%, and
i, the first vertex at 45.0 at% (point E in FIG. 2), Ti
50.5 at%, Au 6.0 at%, and Ni 43.5
2nd vertex (point I in FIG. 2) at at%, Ti50.5a
Third vertex (point C in FIG. 2) at t%, Au 15.0 at% and Ni 34.5 at%, Ti 49.0 at%, A
u 45.0 at% and Ni 36.0 at%
Apex (point D in FIG. 2), Ti 49.0 at%, Au 9.0
at% and Ni at 42.0 at% (FIG. 2)
J point), 49.2 at% of Ti, 7.0 at% of Au, and 43.8 at% of Ni in the region defined by a hexagon having a sixth vertex (point K in FIG. 2), and a good shape. 2. The biocompatible T according to claim 1, wherein the T has excellent memory characteristics and Ni ion elution inhibiting properties.
It is an iNiAu-based alloy material.

According to a fourth aspect of the present invention, in the first aspect, 49.0 at% of Ti, 6.0 at% of Au and
i, the first vertex at 45.0 at% (point E in FIG. 2), Ti
49.8 at%, Au 6.0 at%, and Ni 44.2
The second vertex at at% (point F in FIG. 2), Ti49.8a
Third vertex (point G in FIG. 2) at t%, Au 7.0 at% and Ni 43.2 at%, Ti 49.0 at%, Au
4th at 11.0 at% and 40.0 at% Ni (point H in FIG. 2), 49.0 at% Ti, 9.0 a.
Six sides with a fifth vertex (point J in FIG. 2) at t% and Ni 42.0 at%, a sixth vertex (point K in FIG. 2) at Ti 49.2 at%, Au 7.0 at% and Ni 43.8 at%. The TiNiAu-based alloy material having excellent biocompatibility according to claim 1, wherein the TiNiAu alloy material has a composition within a region defined by the shape, and has good superelasticity, shape memory properties, and elution inhibition of Ni ions. It is.

[0010] The invention of claim 5 is the above-mentioned claim 1.
4. Ti, A of the TiNiAu-based alloy according to any one of
u, a part of the Ni composition is Co, Cr, Cu, Fe, Hf,
An alloy material in which one or more of Mn, Mo, Nb, Pd, Pt, and Zr are substituted with a total amount of 0.1 to 2.0 at%, and the crystal grain size of the structure of the alloy material is 200 μm
TiN excellent in biocompatibility characterized by:
It is an iAu-based alloy material.

Further, the invention according to claim 6 is the invention according to claim 1 to claim 1.
5. A member for medical equipment, characterized by using the TiNiAu-based alloy material according to any one of 5.

The invention according to claim 7 is the medical device member according to claim 6, wherein the TiNiAu-based alloy material is any one of a plate material, a tube material, a wire material, and a cast material.

Further, the invention of claim 8 is the above-described claim 1 to claim 1.
5. A member for medical equipment, wherein the member made of the TiNiAu-based alloy material according to any one of 5) is coated with a Ti oxide film or a synthetic resin or a Ti oxide film and a synthetic resin.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The present invention has an effect of suppressing elution of Ni element in a living body without impairing superelasticity and shape memory characteristics by adding Au to a TiNi alloy, and is excellent when used as a member for medical equipment. It is characterized by having biocompatibility.

In a normal TiNi alloy, the longer the immersion time in the living body, the higher the elution concentration of Ni ions increases in proportion to the immersion time. As time elapses, Au dissolved in the matrix diffuses and concentrates on the surface, and N
Elution of i-ion can be suppressed. Therefore, it can be said that the TiNiAu-based alloy material of the present invention is suitable for use in a living body for a long time, that is, is excellent in biocompatibility.

In the following, the invention of each claim will be described in detail, in order, in terms of the configuration and effects of the invention, specific embodiments, and the like. First, in the invention of claim 1, the alloy composition is as follows:
In the ternary composition diagram of Ti, Au and Ni, Ti49.
0 at%, Au 2.0 at%, and Ni 49.0 at%
, The first vertex (point A in FIG. 2), Ti 50.5 at%,
A second at 2.0 at% Au and 47.5 at% Ni
Vertex (point B in FIG. 2), Ti 50.5 at%, Au15.
Third vertex at 0 at% and Ni 34.5 at% (point C in FIG. 2), Ti 49.0 at%, Au 15.0 at%
And the fourth vertex at Ni 36.0 at% (D in FIG. 2)
(Point), and has a composition within a region defined by a quadrilateral having a point, and the crystal grain size of the structure of the alloy material is 200 μm or less.

The range of the alloy composition of the present invention is shown in FIG.
It is a range surrounded by point D. That is, a first vertex (point A in FIG. 2) and a second vertex (B in FIG. 2) of predetermined amounts of Ti, Au, and Ni.
Point), third vertex (point C in FIG. 2), fourth vertex (D in FIG. 2)
(Point) in a region defined by a quadrilateral having a point. The range for each element is Ti49.0 to 50.5a.
t%, Au 2.0-15 at%, Ni residue (34.5-4
9.0 at%). In the alloy material of the present invention, if the Ti content is less than 49.0 at%, the workability becomes difficult due to excessive generation of TiNi-based precipitates, and the Ti content is 50.5 at%.
Exceeding Ti is not preferable because a Ti-based oxide is generated and ductility is deteriorated. Therefore, the Ti content is 49.0 to 50.5.
at% range.

The effect of the added amount of Au element is 2.0%.
at% or more, but more preferably 6.0a sufficient for the Au diffusion layer to cover the outer surface inside the material.
t% or more. The upper limit of the amount of Au added may be large from the viewpoint of corrosion resistance, that is, biocompatibility, but the effect of the addition of Au is sufficient up to 15 at%. . In addition, due to an extreme decrease in the amount of Ni due to an increase in Au, the shape memory or superelastic properties are deteriorated. Therefore, the addition amount of Au is set to 2.0 to 15 at%. In the ternary TiNiAu alloy material of the present invention, the Ni amount is a predetermined amount of Ti,
The remainder of the Au addition is in the range of 34.5 to 49.0.
at%.

Further, the present invention relates to a TiNiAu alloy material having the above-mentioned predetermined alloy composition, and further, in the metal structure of this alloy material, the crystal grain size is set to 200 μm or less. The crystal grain size of the metal structure of the alloy material of the present invention is 2
The reason why the size is limited to 00 μm or less, that is, the crystal grain size is reduced is to make Au easily diffuse to the surface of the material. Au element diffuses to the material surface along the crystal grain boundary. Therefore, as the crystal grain size becomes smaller, the area of the grain boundary increases, and the crystal grain becomes easier to diffuse. Note that TiNi
The effect of suppressing the elution of Ni ions by adding Au to the alloy material is that the diffusion of Au element to the material surface is faster than the diffusion rate of Ni element. It is considered that the Au film (or its oxide) diffuses and suppresses elution of Ni ions.

As a means for reducing the crystal grain size of the metal structure of the alloy material, it is effective to introduce a work structure by expanding (forging, rolling, drawing, etc.) the cast material. Implants (for example, bone plates and artificial roots), orthodontic wires, catheters, guide wires, and the like, which are members for medical devices, are manufactured by this spreading process. When using the cast material by precision casting as it is, the cooling rate is set to 100 ° C. in order to make the casting structure fine.
/ Sec or more is desirable. Examples of using the precision casting material as it is include a dental crown and a dental clasp.

Next, the inventions of claims 2, 3 and 4 are preferred embodiments of the invention of claim 1. That is, the invention of claim 2 is the invention according to claim 1, wherein Ti49.
0 at%, Au 6.0 at%, and Ni 45.0 at%
, The first vertex (point E in FIG. 2), Ti 49.8 at%,
Second at 6.0 at% Au and 44.2 at% Ni
Vertex (point F in FIG. 2), Ti 49.8 at%, Au 7.0
at% and Ni at 43.2 at% (FIG. 2)
G point), 49.0 at% of Ti, 11.0 at% of Au and 40.0 at% of Ni at the fourth vertex (point H in FIG. 2)
A composition within an area defined by a quadrilateral having
It is characterized by having particularly excellent superelastic properties and Ni ion elution suppressing properties. Note that, in the metal structure of the alloy material, the crystal grain size is set to be equal to or smaller than a predetermined value, as in the first aspect.

The alloy composition of the present invention comprises Ti,
The ternary composition diagram of Au and Ni is a range surrounded by the EFGH point in FIG. That is, the first vertices (point E in FIG. 2), the second vertices (point F in FIG. 2), the third vertices (point G in FIG. 2), and the fourth vertices (point G in FIG. 2) of predetermined amounts of Ti, Au, and Ni. H point) in a region defined by a quadrilateral having a quadrangle. Compositions in this range have good superelastic properties and suppress the elution of Ni ions, and are particularly suitable for use as a superelastic alloy material.

The amount of Au is particularly excellent at 6 at% or more in suppressing the elution of Ni ions. Further, the transformation temperature rises when the Au content is 7 at% or more, and the transformation temperature rises when the Ti content further increases. For this reason, when the Ti content and the Au content are higher than the line FGH, the transformation temperature becomes higher, which is not suitable for utilizing superelastic properties. Therefore, when the good superelastic property and the ability to suppress the elution of Ni ions are used, the composition is in the region defined by the quadrilateral having the EFGH point in FIG. In addition, as a member for a medical device particularly utilizing the superelastic property, there is an orthodontic wire and the like.

Next, according to the invention of claim 3, within the scope of claim 1, the first vertex located at 49.0 at% of Ti, 46.0 at% of Au and 45.0 at% of Ni (E in FIG. 2).
Point), Ti 50.5 at%, Au 6.0 at% and N
i The second vertex at 43.5 at% (point I in FIG. 2), Ti
50.5 at%, Au 15.0 at% and Ni34.
Third vertex at 5 at% (point C in FIG. 2), Ti49.0
at%, Au 15.0 at% and Ni 36.0 at%
, The fourth vertex (point D in FIG. 2), Ti 49.0 at%,
5th at Au 9.0 at% and Ni 42.0 at%
Apex (point J in FIG. 2), Ti 49.2 at%, Au 7.0
at% and Ni at 43.8 at% (FIG. 2)
(K point) in a region defined by a hexagon, and is characterized by having particularly good shape memory characteristics and Ni ion elution suppressing properties. Note that, in the metal structure of the alloy material, the crystal grain size is set to be equal to or smaller than a predetermined value, as in the first aspect.

The alloy composition of the present invention was changed to Ti,
The ternary composition diagram of Au and Ni is shown in FIG.
It is the range enclosed by the point. That is, a first vertex (point E in FIG. 2), a second vertex (point I in FIG. 2) of a predetermined amount of Ti, Au, Ni,
A hexagon having a third vertex (point C in FIG. 2), a fourth vertex (point D in FIG. 2), a fifth vertex (point J in FIG. 2), and a sixth vertex (point K in FIG. 2). Composition within the region of interest.

Compositions in this range have good shape memory properties and Ni ion elution inhibiting properties and are particularly suitable for use as shape memory alloy materials. An Au content of at least 6 at% is particularly effective in suppressing the elution of Ni ions. Line E
If the Ti content and the Au content are lower than KJD, the transformation temperature becomes lower, which is not suitable for utilizing shape memory characteristics. Therefore, when utilizing good shape memory characteristics and the ability to suppress the elution of Ni ions, the composition is within the region defined by the hexagon having the EIDJJK point in FIG. In particular, as a member for a medical device utilizing the shape memory characteristic, there is an implant (for example, a bone plate) or the like.

Next, according to the invention of claim 4, the first apex located at 49.0 at% of Ti, 6.0 at% of Au and 45.0 at% of Ni within the scope of claim 1 (E in FIG. 2).
Point), 49.8 at% of Ti, 6.0 at% of Au and N
i The second vertex at 44.2 at% (point F in FIG. 2), Ti
49.8 at%, Au 7.0 at%, and Ni 43.2
Third vertex at at% (point G in FIG. 2), Ti49.0a
The fourth vertex (point H in FIG. 2) at t%, Au 11.0 at% and Ni 40.0 at%, Ti 49.0 at%, A
The fifth vertex (point J in FIG. 2) at u 9.0 at% and Ni 42.0 at%, Ti 49.2 at%, Au 7.0 a
The composition is within a region defined by a hexagon having a sixth vertex (point K in FIG. 2) at t% and Ni 43.8 at%, and has particularly good superelasticity, shape memory characteristics, and suppression of elution of Ni ions. It has characteristics. Note that, in the metal structure of the alloy material, the crystal grain size is set to be equal to or smaller than a predetermined value, as in the first aspect.

The alloy composition according to the present invention is changed to Ti,
The ternary composition diagram of Au and Ni shows that EFGHJ in FIG.
The area is surrounded by the point K. That is, a first vertex (point E in FIG. 2) and a second vertex (point F in FIG. 2) of predetermined amounts of Ti, Au, and Ni.
Point), third vertex (point G in FIG. 2), fourth vertex (H in FIG. 2)
Point), sixth vertex (point J in FIG. 2), sixth vertex (K in FIG. 2)
(Point) in the area defined by the hexagon.

The composition in the region defined by the hexagon having the EFGHJK point shown in FIG. 2 has good superelasticity, shape memory characteristics, and Ni ion elution inhibiting properties, and is particularly suitable for superelastic and shape memory alloys. Suitable when used as a material. An Au content of at least 6 at% is particularly effective in suppressing the elution of Ni ions. Therefore, good superelasticity and shape memory characteristics and Ni
If ion elution suppression is required, use the EFG of FIG.
The composition within a region defined by a hexagon having an HJK point is obtained. As a medical device member for such an application,
There are implants (for example, artificial dental roots) and the like. When used as an implant (artificial dental root) as a living body member, shape memory characteristics are required during implantation from outside air into the body, and superelastic properties are required inside the body.

Next, a fifth aspect of the present invention is the first aspect of the present invention.
4. Ti, Au, of the TiNiAu alloy according to any of 4.
Co, Cr, Cu, Fe, Hf, M
An alloy material in which one or more of n, Mo, Nb, Pd, Pt, and Zr are substituted with a total amount of 0.1 to 2.0 at%, and the crystal grain size of the structure of the alloy material is 200 μm TiNi with excellent biocompatibility characterized by the following:
It is an Au-based alloy material. In the alloy material of the present invention, Co, C
r, Cu, Fe, Hf, Mn, Mo, Nb, Pd, P
Since the addition of t and Zr has the effect of lowering the transformation temperature, this action is used to adjust the transformation temperature to a desired temperature. If the total amount is less than 0.1 at%, the effect on the transformation temperature is small, and it is not sufficient.
If the content exceeds t%, workability deteriorates. Therefore, the total amount of addition is set to 0.1 to 2.0 at%.

Next, a sixth aspect of the present invention is directed to the first aspect.
5. A member for medical equipment, characterized by using the TiNiAu-based alloy material according to any one of 5. Since the alloy material of the present invention is excellent in biocompatibility, it is mainly used as a member for medical equipment. Examples of medical device components include, but are not limited to, implants,
Orthodontic wires, dental crowns, dental clasps, stents, catheters, guide wires, and the like. These medical device members are appropriately selected and used from the above-described alloy materials of the present invention according to their required characteristics.

[0032] The invention of claim 7 is characterized in that, in the invention of claim 6, the TiNiAu-based alloy material is any one of a plate material, a tube material, a wire material, and a cast material. The alloy material of the present invention is manufactured and processed into a shape such as a rolled plate material, a drawn wire material, a tube material, a precision cast material, or the like, as required, for the purpose of the above-mentioned medical device members. To give an example, implants (bone plates, artificial dental roots) are used in the form of plates, catheters are used in the form of tubes, orthodontic wires and guide wires are used in the form of wires, and dental crowns are used in the form of cast materials.

Further, the invention of claim 8 provides the above-mentioned claims 1 to
5. A member for medical equipment, wherein the member made of the TiNiAu-based alloy material according to any one of 5) is coated with a Ti oxide film or a synthetic resin or a Ti oxide film and a synthetic resin. The present invention is to coat the surface of the alloy material with a Ti oxide film or a synthetic resin by a dry or wet method in order to improve the elution suppression of metal elements in the alloy material and the wear resistance of the material surface. It is also possible to further cover the Ti oxide film with a synthetic resin. FIG. 3 shows a catheter member 1 as an example of the present invention, in which a superelastic alloy tube material 2 is coated on its outer surface with a Ti oxide film 3 and a synthetic resin film 4. In addition, the member coated in this manner suppresses elution of the metal element in the alloy material, but even if it is damaged during use, the alloy material of the present invention is Ni Elution of ions can be suppressed.

The alloy material of the present invention exhibits excellent properties not only in the living body but also in contact with the human body, for example, as a frame material for eyeglasses. Furthermore, since the alloy material of the present invention is excellent in corrosion resistance to environments such as water and seawater, it can be applied to the use in particular, that is, the use for long-term immersion.

[0035]

EXAMPLES Examples of the present invention will be described below along with comparative examples. Example 1 After weighing 3 kg of a sample weighed so as to have an alloy composition shown in Table 1 by a high-frequency induction heating melting method,
After casting, the obtained ingot was face-cut, and then hot forged and rolled to obtain a wire having a diameter of 6 mm. Next, this diameter 6
For a wire rod having a diameter of 1.0 mm, cold drawing and intermediate annealing were repeated to obtain a fine wire having a diameter of 1.0 mm. About this thin line,
Inventive Example No. of Table 1 Nos. 1 and 2 were heat treated at 450 ° C. for 30 minutes. No. 3 was a heat treatment at 600 ° C. for 30 minutes. 1 is heat treatment at 450 ° C. for 30 minutes, Comparative Example N
o. Heat treatment was performed at 950 ° C. × 5 hours for the samples 2 and 3.

With respect to these wire samples, the crystal grain size as a metal structure was observed and measured, and the results are shown in Table 1. A specific method of measuring the crystal grain size is as follows. First, a cross section of the wire (a cross section perpendicular to the longitudinal direction of the wire) is subjected to a post-polishing corrosion treatment to reveal a metal structure, and then observed with a microscope. This is a line segment cutting method in which the number of crystal grains completely cut by a line segment of a known length on a photograph is counted, and the grain size is determined by an average value of the cut length. In this example, the average value of the six line segments by the line segment cutting method was determined in consideration of the anisotropy of the crystal grains, and the results are shown in Table 1.

Table 1 shows the results of the measurement of the transformation temperature by the DSC method and the results of the investigation of the superelastic properties and shape memory properties by the tensile test at each temperature from 0 ° C. to 40 ° C.
Note that the transformation temperature is a reverse transformation temperature (Af) which is a transformation temperature from a martensite phase which is a low-temperature phase to a parent phase which is a high-temperature phase.
Points) are shown in Table 1. Super-elastic properties, 4% tensile strain
After giving, it was evaluated by the residual strain when unloading. A material having a residual strain rate of 0.5% or less, which is an index of the superelastic effect, is ◎ (very excellent property), a material of 0.5 to 1% is ○ (excellent property), and 1 to 2%. The material is △ (slightly inferior property), 2
% Or more of the materials were evaluated as x (poor property).

The shape memory characteristics were evaluated by the amount of residual strain after heating to Af point + 50 ° C. after applying 4% of tensile strain. A material having a residual strain rate of 0.5% or less is ◎ (very excellent property), a material having a residual strain of 0.5 to 1% is ○ (excellent property),
1% to 2% of the materials were evaluated as Δ (somewhat inferior properties), and 2% or more of the materials were evaluated as × (inferior properties).

[0039]

[Table 1]

As is clear from Table 1, the present invention example No.
Nos. 1 and 2 each show excellent superelastic properties. 1 to 3 all exhibited excellent shape memory characteristics. Inventive Example No. having a crystal grain size of 100 μm. In the case of No. 3, the superelastic property is slightly inferior, but there is no problem in practical use. Comparative Example No. 1 having a crystal grain size exceeding 200 μm. 2 and 3 are practical problems.

In order to investigate corrosion resistance from the viewpoint of biocompatibility, an elution test was performed, and biocompatibility was evaluated based on the amount of metal ions eluted. In the dissolution test, the thin wire having a diameter of 1.0 mm was cut into a predetermined size (40 mm), and an oxide film was removed, ultrasonic cleaning with ultrapure water, and drying were performed to obtain a test piece for dissolution test. Dilute high-purity lactic acid to 1.0% with ultrapure water, 37 ℃
7 days, 30 days, 100 days, and 300 days in the lactic acid held in the above, the immersion solution was subjected to quantitative analysis of the ion concentration in the solution using an ICP emission spectrophotometer, and the unit area from each sample was measured. Table 1 shows the results of determining the amount of eluted ions per unit (mg / m ² ).

In the present sample, the amount of ions eluted other than Ni ions was negligible compared to the amount of Ni ions, so only the amount of Ni ions eluted is described. Biocompatibility is
In each sample with an immersion time of 300 days, the average of the elution amount of Ni ions in the binary alloy of TiNi (Comparative Example N
o. Assuming that 1) is 100%, materials with an elution amount of less than 60% in each sample are ◎ (very excellent effect), 60 to 7
5% of the materials were evaluated as ○ (excellent effect), 75 to 90% of the materials were evaluated as Δ (somewhat improved), and 90% or more of the materials were evaluated as × (equivalent to the conventional material). In practice, the effect of ◎ or ○ is required. The amount of Ni-eluting ions of the alloy material of the present invention is smaller than that of the comparative example, and the elution amount is becoming saturated particularly over a certain number of days or more, and shows excellent biocompatibility.

Example 2 A sample weighed so as to have the alloy composition shown in Table 2 was formed into a fine wire having a diameter of 1.0 mm in the same manner as in Example 1. About this thin line, 45
A linear memory heat treatment was performed at 0 ° C. for 30 minutes. For these samples, measurement of crystal grain size, DSC
Measurement of transformation temperature by the method, superelastic property by the tensile test
Evaluation of shape memory properties and biocompatibility by dissolution test were performed. Table 2 shows the results. In addition, the superelastic property
Symbols for evaluation of shape memory characteristics and biocompatibility (◎, ○, △,
The meaning of ×) is the same as in Example 1. Materials that did not exhibit superelasticity because the measurement temperature was lower than the transformation temperature were not measured, and are shown in Table 1 as "-". Further, a material which does not show a shape memory because the measurement temperature is higher than the transformation temperature is not measured, and "-" is shown in Table 1.

[0044]

[Table 2]

As is clear from Table 2, Example No. 1 of the present invention.
6, 8, 9, and 10 all show excellent superelastic properties. 4 to 9, 11, and 12 all exhibited excellent shape memory characteristics. In addition, the present invention example No. 5,
No. 11, the superelastic property was not improved. In 13 and 14, the shape memory characteristics are slightly inferior, but there is no problem in practical use.
No. of the comparative example. 5 and 6 are practical problems. And, the elution ion amount of the alloy material of the present invention is smaller than that of the comparative example, and the elution amount is becoming saturated particularly in a certain number of days or more,
Shows excellent biocompatibility.

Example 3 3 kg of a sample weighed so as to have an alloy composition shown in Table 3 was melted by a high-frequency induction heating melting method, and then cast. After being extruded to form a hollow pipe, a tube material having an outer diameter of 1.0 mm and an inner diameter of 0.8 mm was produced by repeated cold drawing with annealing, and then subjected to linear memory heat treatment at 450 ° C. for 30 minutes. . Note that this test sample assumes a catheter member for a medical device. As in Example 1, Table 3 shows the results of the measurement of the crystal grain size of the metal structure, the measurement of the transformation temperature by the DSC method, the evaluation of the superelastic property and shape memory property by the tensile test, and the biocompatibility by the dissolution test. .

[0047]

[Table 3]

The superelastic property of the alloy material of the present invention is a property applicable to use of catheters and guide wires for medical purposes, and the shape memory property is a property sufficient for use of stents and the like. Further, the elution amount of Ni ions is smaller than that of a conventional binary TiNi alloy, indicating that the material is excellent in biocompatibility.

(Example 4) As a member for medical equipment according to the present invention, the tube material having an outer diameter of 1.0 mm and an inner diameter of 0.8 mm prepared in Example 3 was used. Was coated with a Ti oxide film and an alloy resin film thereon. The thickness of the Ti oxide film is 10 μm,
The thickness of the alloy resin (polyamide elastomer) film is 100 μm. A part of this sample was scratched to remove the above-mentioned film, thereby exposing the alloy material.
An elution test of Ni ions was performed. As a result of this test, the elution of Ni ions was naturally extremely small because the alloy material was coated, and the elution of Ni ions per exposed area was the same as in Examples 1 to 3.

[0050]

As described above in detail, the alloy material of the present invention has superelasticity and shape memory characteristics, and is excellent in corrosion resistance, and particularly, excellent in biocompatibility because elution of Ni ions can be suppressed as much as possible. ing. Therefore, the alloy material of the present invention can be used as a medical device member such as an implant, an orthodontic wire, a dental crown, a dental clasp, a stent, a catheter, and a guide wire which are used for a long time in vivo.

In a specific range, the alloy material of the present invention has particularly good superelastic properties or shape memory properties, or both properties, and the ability to inhibit the elution of Ni ions. Therefore, the alloy material of the present invention has an industrially remarkable effect such that the alloy material of the present invention can be appropriately selected and used in accordance with the required characteristics of the medical device component.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an alloy composition range of the present invention in a ternary phase diagram of TiNiAu.

FIG. 2 is an enlarged detailed view of the alloy composition range of the present invention in FIG.

FIG. 3 is an example of the present invention and is a cross-sectional view of a catheter member.

[Description of Signs] 1 Member for catheter 2 Superelastic alloy material 3 Ti oxide film 4 Synthetic resin film

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) // C22C 14/00 C22C 14/00 Z

Claims (8)

[Claims] In the ternary composition diagram of Ti, Au and Ni, the alloy composition is as follows: Ti 49.0 at%, Au 2.0 at
% And the first peak at 49.0 at% Ni, Ti5
0.5 at%, Au 2.0 at%, and Ni 47.5 a
t5%, Ti50.5 at%, Au15.
Third vertex at 0 at% and Ni 34.5 at%, T
i49.0at%, Au15.0at% and Ni3
Excellent in biocompatibility characterized by having a composition within a region defined by a quadrilateral having a fourth vertex at 6.0 at% and having a crystal grain size of the structure of the alloy material of 200 μm or less. TiNiAu alloy material. 2. The method according to claim 1, wherein Ti49.
0 at%, Au 6.0 at%, and Ni 45.0 at%
At the first vertex, Ti at 49.8 at%, Au at 6.0 at
% And the second vertex at 44.2 at% Ni, Ti4
9.8 at%, Au 7.0 at%, and Ni 43.2a
Third vertex at t%, Ti 49.0 at%, Au11.
2. The composition according to claim 1, wherein the composition is in a region defined by a quadrilateral having a fourth vertex at 0 at% and Ni at 40.0 at%, and has good superelastic properties and Ni ion elution suppression properties. 3. TiN with excellent biocompatibility as described
iAu-based alloy material. 3. The method according to claim 1, wherein Ti49.
0 at%, Au 6.0 at%, and Ni 45.0 at%
At the first vertex, Ti 50.5 at%, Au 6.0 at
% And the second peak at 43.5 at% Ni, Ti5
0.5 at%, Au 15.0 at%, and Ni 34.5
Third vertex at at%, Ti 49.0 at%, Au1
Fourth vertex at 5.0 at% and Ni at 36.0 at%, 49.0 at% Ti, 9.0 at% Au and Ni
5th vertex at 42.0 at%, Ti 49.2 at%,
No. 6 at Au 7.0 at% and Ni 43.8 at%
2. The biocompatible TiNiAu-based composition according to claim 1, wherein the composition is in a region defined by a hexagon having vertices, and has good shape memory characteristics and a property of suppressing elution of Ni ions. Alloy material. 4. The method according to claim 1, wherein Ti49.
0 at%, Au 6.0 at%, and Ni 45.0 at%
At the first vertex, Ti at 49.8 at%, Au at 6.0 at
% And the second vertex at 44.2 at% Ni, Ti4
9.8 at%, Au 7.0 at%, and Ni 43.2a
Third vertex at t%, Ti 49.0 at%, Au11.
The fourth vertex at 0 at% and Ni 40.0 at%, T
i49.0 at%, Au9.0 at% and Ni42.
5th vertex at 0 at%, Ti 49.2 at%, Au
A composition within a region defined by a hexagon having a sixth vertex at 7.0 at% and Ni 43.8 at%;
The TiNiAu-based alloy material having excellent biocompatibility according to claim 1, wherein the TiNiAu-based alloy material has good superelasticity, shape memory properties and Ni ion elution suppression properties. 5. The T according to claim 1, wherein
Part of the Ti, Au and Ni composition of the iNiAu alloy is C
o, Cr, Cu, Fe, Hf, Mn, Mo, Nb, P
One or more of d, Pt, and Zr have a total amount of 0.1.
A TiNiAu-based alloy material having excellent biocompatibility, wherein the alloy material is substituted with 1 to 2.0 at%, and the crystal grain size of the structure of the alloy material is 200 μm or less. 6. The T according to claim 1, wherein
A medical device member using an iNiAu-based alloy material. 7. The medical device member according to claim 6, wherein the TiNiAu-based alloy material is any one of a plate material, a tube material, a wire material, and a cast material. 8. The T according to claim 1, wherein
A member for medical equipment, wherein a member made of an iNiAu-based alloy material is coated with a Ti oxide film or a synthetic resin or a Ti oxide film and a synthetic resin.