JPS5812650A - Biometal material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a prosthetic material used inside and outside the human body to restore function when a part of the human body loses function due to an accident or various diseases.

Prosthetics used for functional recovery include various types of orthopedic fixation devices for joints and fractures, as well as hard tissue materials that bear loads such as dental materials, and reinforcement materials such as valves for the heart and arteries. be. Currently, these prosthetics include 304 stainless steel, 316L stainless steel 1/X, 317 stainless steel, and c
op-1 (Co, Cr, Nl each 20q6Mo 4%
P 0.2%, residual re), vital fz rm ((b-C
r alloy H821 contains 27-30% Cr, Mo
5-7 'It', Nl (0,5%), H82S (
Co group, 14 to 16 inches W, 9 to 11 inches, TJ-6λ
7-4V, NiT1, etc. have been used, and although each has characteristics of excellent wear resistance, corrosion resistance, and workability, there is no material that satisfies all the properties as a prosthetic material. The requirements for metal materials to be used in living organisms are that they have excellent corrosion resistance (withstand pH of about 5), good compatibility with living organisms, and excellent mechanical properties.

Regarding corrosion resistance, currently available materials include gold, platinum, tantalum,
Titanium, titanium alloys, cobalt-chromium alloys for casting (H
821) and cobalt alloy for processing (H825) stainless steel, and the latter two have problems in corrosion resistance. However, cobalt-chromium alloys are undesirable because their concentration increases in the blood after long-term use. In terms of biocompatibility, harmful ions should be avoided that may cause necrosis of cells that have changed the surrounding tissue, and there are concerns about Nl content as N1 is carcinogenic. Titanium has also been found to accumulate in surrounding tissues in animal experiments;
It is unknown whether there are any harmful effects. Regarding mechanical properties, tensile strength, proportional limit,
Elastic modulus, impact strength, fatigue strength in body fluids, and wear resistance for artificial joints are required. A high modulus of elasticity is required for fixing fractures, etc., but on the other hand, in terms of ease of conformability at the interface with bone, the size of IAO, such as iron, is required to be comparable to that of bone.

The present invention was made in view of the above-mentioned matters, and has excellent corrosion resistance required in vivo, good compatibility with living organisms, and
The present invention provides a prosthetic material with excellent mechanical properties. In other words, as mentioned above, the total properties required for a prosthetic material are 1.
This is difficult to obtain from other types of metals or alloys, so it is made by coating a metal with excellent mechanical strength with a metal that has excellent coexistence with the human body and does not cause changes to the surrounding tissue due to its moderate elastic modulus. Therefore, the object of the present invention is to provide the above-mentioned properties required as a prosthetic material.

Next, as an embodiment of the present invention, the functions and effects of aluminized stainless steel, which is stainless steel lined with aluminum ζnium, will be explained.

The elastic modulus of bone is 1,700 to 1,900 kg. For example, Fa, Cr, N1, etc. are husband* 190:00,253
00.20500kg/-, which is about 10 times more. However, AAr, Au, Sn, Zr, etc. are each close to those of 7570 bone, and when these materials are used as prosthetic materials, gaps are created at the interface with the bone, resulting in necrosis of bone cells due to concentration of stress at critical points. It can prevent the causes of tumor development. Furthermore, the above metals such as A/, Au8n, and Zr have excellent corrosion resistance in an oxidizing environment.
It is not a ratio such as i. However, the above A/, Au, Sn,
Metals such as Zr have poor mechanical properties, e.g. L if' Tl
-6AJ -4V TeC1) Proof strength 84 kg/d
, the tensile strength is 94 kg/- elongation 11q6, while M shows various values depending on the purity, heat treatment, and processing method, but even the highest one has a yield strength of 49.9 at 2024-Ta2.
kg/$IIg, tensile strength 52.7 kg/m, elongation 6%, 2024-T4 Teo* 93. Ok
g/sd, 47.8 kg g/id, 3 weights, and normal M are 5 to 15 kg/ml, 7 to 17 kg, and Tochi Yu, respectively. Therefore, for example, martensitic stainless steel (yield strength>50kg/ld, tensile strength>
70 kg/-1 elongation>25) is coated with an alonium film, for example, by hot-dip plating or diffusion coating. This reduces the mechanical properties of the material compared to stainless steel, but significantly improves corrosion resistance in an oxidizing atmosphere.

Furthermore, since M is a light metal, it does not accumulate in the body and increase its blood concentration, nor does it affect surrounding tissues. Furthermore, it is used in artificial joints, etc., and does not cause wear and tear on surrounding tissues. Furthermore, hot-dip aluminum plating and diffusion coating methods both have a long history and have good factory productivity.Furthermore, M easily forms a thin oxide film on the surface, so it has good wettability and is well compatible with the surrounding tissue. do.

As an example of the present invention, we have described a prosthetic material in which stainless steel is coated with aluminum, but a material with excellent mechanical properties is coated with a material that is not harmful to living organisms, has excellent compatibility, and has good corrosion resistance. Any biometal material may be used.

Agent: Patent Attorney Noriyuki Chika (1 other person)

Claims (1)

[Claims] A biometal material characterized by a base metal coated with aluminum.