JP2014136816A - Fixture for an anodic oxidation treatment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a medical implant having sufficiently lowered concentrations of impurities included within an anodic oxidation film for improving the corrosion resistance.SOLUTION: A fixture 1 for an anodic oxidation treatment comprises a support unit 1a for supporting a treatment target material B consisting of a magnesium material or magnesium alloy material in a state where the electroconductive portion thereof including the support unit 1a, immersed at least within an electrolytic liquid C, and having an electroconductivity contributing essentially to conduction comprises, apart from inevitable impurities, magnesium material or magnesium alloy material including virtually no aluminum, copper, or nickel.

Description

  The present invention relates to an anodizing jig.

Conventionally, in order to improve the corrosion resistance of a product made of a magnesium alloy material, an anodizing treatment for forming an anodized film on the surface of the product has been performed.
In this anodizing treatment, an anodizing jig is known in which a contact material made of magnesium is removably screwed to a portion that is in direct contact with the material to be treated (see, for example, Patent Document 1). .

  The jig disclosed in Patent Document 1 is configured such that a contact material is screwed to the tip of a bifurcated beam-like support column member having elasticity, and the material to be processed is supported by the elasticity of the support column material. The support pillar material is constituted by a piano wire material having elasticity.

Japanese Patent No. 3408802

  However, when applied to a medical implant as a material to be treated, the anodizing jig of Patent Document 1 has a problem. In other words, when a support pillar made of piano wire is immersed in the electrolyte, the metal material constituting the support pillar is eluted into the electrolyte and becomes a component of the anodized film on the surface of the material to be treated. There is a problem of being included.

  The present invention has been made in view of the above-described circumstances, and can be used for anodizing treatment that can produce a medical implant in which the concentration of impurities contained in an anodized film for improving corrosion resistance is sufficiently reduced. The purpose is to provide a jig.

In order to achieve the above object, the present invention provides the following means.
One embodiment of the present invention includes a support portion that supports a material to be processed that is made of a magnesium material or a magnesium alloy material, and includes the support portion and has a conductivity that is substantially immersed in an electrolytic solution and contributes to conductivity. However, there is provided an anodizing jig made of a magnesium material or a magnesium alloy material substantially free of aluminum, copper and nickel except for inevitable impurities.

  According to this aspect, the material to be treated supported by the support portion is immersed in the electrolytic solution, and the current to be treated is made between the cathode disposed in the electrolytic solution with the treated material as the anode through the conductive portion having conductivity. As a result, an anodized film is formed on the surface of the material to be treated. Even if a conductive portion made of magnesium material or magnesium alloy material substantially free of aluminum, copper, and nickel is eluted into the electrolytic solution during anodization, these substances are formed on the surface of the material to be treated. It can be prevented from being contained in the anodized film.

In the said aspect, the said electroconductive part may consist of a magnesium material or magnesium alloy material whose content of aluminum, copper, and nickel is 0.2% or less.
Moreover, in the said aspect, the said electroconductive part may consist of the magnesium material or magnesium alloy material which improved the purity more than the said to-be-processed material.

  Moreover, in the said aspect, the said support part is equipped with two or more holding pieces which can adjoin or space apart so that a to-be-processed material may be pinched | interposed, and the said electroconductive part is the said support part and this support part An arm portion electrically and mechanically connected to at least one of the grip pieces and extending through the electrolyte surface, and above the electrolyte surface, the grip piece There may be provided a gripping force generating part that generates a force applied to the arm part in a direction in which they are brought close to each other.

  By doing so, the force generated in the gripping force generator disposed outside the electrolyte is transmitted to the gripping pieces in the electrolyte via the arm, and the gripping pieces are brought close to each other, thereby The material to be processed is supported between the pieces. By arranging the gripping force generation part outside the electrolyte, even if a material other than magnesium and magnesium alloy material is used as the gripping force generation part, the component does not elute into the electrolyte during anodizing treatment. . As a result, even if the arm part and the support part are made of a low-elasticity magnesium material or magnesium alloy material, a force sufficient to grip the workpiece is generated by the gripping force generator to stabilize the workpiece. Can be supported.

Moreover, in the said aspect, the biasing member which biases the said arm part elastically in the direction which makes the said holding piece mutually approach may be sufficient as the said gripping force generation | occurrence | production part.
By doing so, the gripping force generating part urges the arm part in a direction to bring the gripping pieces close to each other by elasticity, so that an external force is applied against the urging force to move the arm part. By separating the gripping pieces and placing the material to be processed between them and releasing the external force, the material to be processed can be sandwiched between the gripping pieces.

Moreover, in the said aspect, the said arm part and the said holding piece may be provided so that attachment or detachment is possible.
By doing in this way, the grip piece in which the anodized film was formed with the to-be-processed material by the anodizing process can be replaced | exchanged.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the medical implant which fully reduced the impurity concentration contained in the anodic oxide film for improving corrosion resistance can be manufactured.

It is a mimetic diagram showing an anodizing device provided with a jig for anodizing processing concerning one embodiment of the present invention. It is a schematic diagram which shows the anodizing apparatus provided with the jig | tool for anodizing treatment which concerns on the 1st modification of FIG. FIG. 6A is a perspective view showing a second modification of the anodizing jig of FIG. 1 and FIG. 5B is a plan view of a gripping force generator. It is a perspective view which shows the 3rd modification of the jig | tool for anodizing treatment of FIG. It is the (a) perspective view which shows the 4th modification of the jig | tool for anodizing treatment of FIG. 1, (b) The longitudinal cross-sectional view which shows the detail of A section.

An anodizing jig 1 according to an embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the anodizing jig 1 according to this embodiment is a jig used in an anodizing apparatus 3 including a processing tank 2 that stores an electrolytic solution C for anodizing. It is a tool.

  The anodizing apparatus 3 includes a processing tank 2, a cathode 4 disposed in the processing tank 2, the anodizing jig 1 according to the present embodiment, the cathode 4 and an anodizing jig. 1 and a power source 5 for supplying a voltage between the

  In the example shown in FIG. 1, the anodizing jig 1 according to the present embodiment is at least partially immersed in the electrolytic solution C in the processing tank 2 and is also immersed in the electrolytic solution C. Is provided with a support portion 1a for supporting a material to be treated (for example, a screw made of a magnesium alloy material) B. The support portion 1a is formed, for example, in a substantially C shape having an opening that is narrower than the head B1 of the screw B and wider than the body B2, and the head B1 of the screw B is placed on the opening edge. Is supported in a suspended manner.

  The anodizing jig 1 according to the present embodiment is made of a magnesium material or a magnesium alloy material that does not substantially contain elements such as aluminum, copper, or nickel, except for inevitable impurities. Here, “substantially free” means that the content is 0.2% by mass or less.

  Further, the anodizing jig 1 according to the present embodiment is made of a magnesium material or a magnesium alloy material having a purity equal to or higher than that of the material B to be processed. Here, the purity equal to or higher than that of the material to be processed B indicates that the content ratio of elements other than magnesium is equal to or lower than the material to be processed B.

  For example, when the workpiece B is ZK61, the anodizing jig 1 is ZK51, when the workpiece B is WE54, the anodizing jig 1 is WE43, and when the workpiece B is WE43, the anode For example, the oxidation treatment jig 1 may be WE43 or pure magnesium.

  And by comprising in this way, the jig | tool 1 for anodizing process which concerns on this embodiment has electroconductivity, is immersed in the electrolyte solution C in the processing tank 2, and is connected to the power supply 5. Thus, the screw B that is in contact with and supported by the support portion 1a functions as an anode, and a surface treatment for forming an oxide film on the surface of the screw B can be performed.

The operation of the anodizing jig 1 according to this embodiment configured as described above will be described below.
In order to perform the anodizing treatment of the material B to be processed using the anodizing jig 1 according to the present embodiment, the opening of the support portion 1a of the anodizing jig 1 is faced downward and the opening edge is covered. The head B1 of the screw that is the treatment material B is hooked and hung.

Then, the lower part including the suspended screw B and the supporting portion 1a of the anodizing jig 1 supporting the screw B is immersed in the electrolytic solution C stored in the processing tank 2. A power source 5 is connected between the cathode 4 disposed in the processing tank 2 and the anodizing jig 1.
As a result, a voltage is applied between the screw B and the cathode 4, and anodization is performed using the screw B as an anode, and an oxide film is formed on the surface of the screw B.

  In this case, the portion including the support portion 1a of the anodizing jig 1 that supports the screw B and energizes also functions as an anode together with the screw B and is consumed during the anodizing process. And the component of the support part 1a eluted in the electrolyte solution C mixes in an oxide film.

  According to the anodizing jig 1 according to the present embodiment, elements such as aluminum, copper, and nickel are substantially not included except for inevitable impurities, and therefore these elements are contained in the oxide film. The concentration can be kept sufficiently low. Furthermore, since it is composed of a magnesium material or magnesium alloy material having a purity equal to or lower than that of the material to be processed B, the concentration of other elements contained in the oxide film is prevented from being increased to be higher than that of the material to be processed B. can do.

  As a result, according to the anodizing jig 1 according to the present embodiment, it is possible to manufacture a medical implant in which the concentration of impurities contained in the anodized film for improving the corrosion resistance is sufficiently reduced. There is.

In addition, in this embodiment, although the screw B was illustrated as a medical implant, it replaces with this and may use the plate and pin for osteosynthesis as the to-be-processed material B.
In the present embodiment, the entire anodizing jig 1 is made of the same material. Instead, at least a portion immersed in the electrolytic solution C has a purity equal to or higher than that of the workpiece B. It may be increased.

  For example, as shown in FIG. 2, the portion 1b of the anodizing jig 1 that is not immersed in the electrolytic solution C is made of a material other than magnesium or magnesium alloy as long as it is a conductive material. It may be.

  Further, in the present embodiment, an example in which the material to be processed B is hooked on the support portion 1a formed in a C shape is illustrated, but as shown in FIG. And a gripping force generator 7 for urging the gripping portions 6a of the gripping pieces 6 in the direction in which the gripping portions 6a of the gripping pieces 6 approach each other. May be.

  In the example illustrated in FIG. 3, each gripping piece 6 includes two arms 6 b and a rod-shaped gripping portion 6 a that is spanned so as to connect between the swinging ends of the arms 6 b. When the arms 6b of the gripping piece 6 are connected so as to be swingable around a common axis D, the two gripping portions 6a are arranged in parallel, and when the arm 6b is swung, the interval between the gripping portions 6a is made closer or separated. It is possible to make it. Thereby, the head B2 of the screw B as the material to be processed B as shown by a chain line in FIG. 3 can be sandwiched in the radial direction by the two gripping portions 6a, and the material to be processed B is supported in a gripped state. It is like that.

  In the example shown in FIG. 3, the gripping force generator 7 is a member having a substantially C-shaped cross section that is fitted to two swingable arms 6 b as shown in FIG. By applying a force indicated by an arrow F so as to slide toward the swing end of the arm 6b, the relative angle of the arm 6b is decreased, and the distance between the gripping portions 6a is reduced by the elastic restoring force. It comes to be energized.

By doing in this way, the holding | grip part 6a can be closely_contact | adhered with the stable pressing force to the outer surface of the to-be-processed material B, and the stable electrical contact can be aimed at.
In addition, since the gripping force generation part 7 requires comparatively high rigidity, it is desirable to be comprised with spring steel, and it is preferable to arrange | position above the liquid level of the electrolyte solution C at the time of an anodizing process.
Both of the gripping pieces 6 may be made of a conductive material such as a magnesium material or a magnesium alloy material, and one of them may be made of a non-conductive material such as quartz glass that does not elute into the electrolytic solution C. .

  Further, instead of the ring-shaped gripping force generator 7, as shown in FIG. 4, a torsion spring 8 that applies a biasing force to the two arms 6b in a direction in which the relative angle decreases is adopted as the gripping force generator. May be. Even in this case, the torsion spring 8 is preferably made of spring steel, and is preferably disposed above the liquid surface of the electrolytic solution C during the anodizing process.

  Further, as shown in FIG. 5B, the arm 6b and the gripping portion 6a may be detachably attached by fitting the convex portion 6c and the concave portion 6d. In the example shown in FIG. 5A, the gap between the swinging ends of the arm 6b is maintained by the rigidity of the connecting shaft 6e that connects the arms 6b, so that the grip 6a is held between the arms 6b. can do.

Instead of this, or in addition to this, a tension spring (not shown) is arranged between the arms 6b, and the gripping portion 6a is held between the arms 6b by the urging force of the tension spring. Good.
Moreover, although the convex part 6c was provided in the arm 6b and the recessed part 6d was provided in the holding part 6a, the reverse may be sufficient. Moreover, the shape of the convex part 6c and the recessed part 6d may be arbitrary as long as it is a shape fitted to each other.

B screw (treated material)
C Electrolyte 1 Jig for anodizing treatment 1a Supporting part 6 Holding piece 6b Arm (arm part)
7 Gripping force generator 8 Torsion spring (Biasing member: Gripping force generator)

Claims (6)

Provided with a support portion for supporting a material to be processed made of magnesium material or magnesium alloy material,
Magnesium material or magnesium alloy material that includes the support part and has at least a conductive part that is immersed in an electrolytic solution and substantially contributes to conduction, except for inevitable impurities, and substantially does not contain aluminum, copper, and nickel Anodizing jig made of   2. The anodizing jig according to claim 1, wherein the conductive portion is made of a magnesium material or a magnesium alloy material having a content of aluminum, copper, and nickel of 0.2% or less.   The anodizing jig according to claim 1, wherein the conductive portion is made of a magnesium material or a magnesium alloy material having a purity equal to or higher than that of the material to be processed. The support portion includes two or more gripping pieces that can be close to or separated from each other so as to grip the material to be processed therebetween,
The conductive portion is electrically and mechanically connected to at least one grip piece of the support portion and each grip piece of the support portion, and includes an arm portion extending through the liquid surface of the electrolytic solution,
4. The anode according to claim 1, further comprising a gripping force generation unit that generates a force applied to the arm unit in a direction in which the gripping pieces are brought close to each other above the liquid surface of the electrolytic solution. Oxidation jig.   The anodizing jig according to claim 4, wherein the gripping force generating portion is a biasing member that elastically biases the arm portion in a direction in which the gripping pieces are brought close to each other.   The anodizing jig according to claim 4 or 5, wherein the arm portion and the grip piece are detachably provided.

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