JP2019076839A - Coating method and manufacturing method for medical treatment wire - Google Patents

Abstract

To form a coating layer of high efficiency and excellent quality over the whole surface of a wire.SOLUTION: A coating method for forming a coating layer over the surface of a wire by the electrostatic coating method includes a step of spraying a coating liquid to the wire by using an electrostatic atomization type spray nozzle. In such a manner, according to a method for performing electrostatic coating to the wire by using the electrostatic atomization type nozzle, a uniform film can be formed without a problem such as dripping as compared with the dipping method. As compared with a spray method using an air atomization spray gun, the process can be more simplified by a factor that the wire needs neither rotation nor inversion. Since the electrostatic atomization type causes almost no overspray, wastes of the coating liquid can markedly be curtailed. Further, continuous coating treatment can be performed, so that even a long wire can easily be coped with.SELECTED DRAWING: Figure 1

Description

  The technology disclosed by the present specification relates to a coating method and a method of manufacturing a medical wire.

  For example, medical guide wires are provided with a coating for imparting slipperiness. As a coating method, techniques such as a dipping method and a spray method using an air atomization type spray gun are mainly used (see Patent Document 1).

Japanese Patent Publication No. 2002-540822

  However, in the dipping method, occurrence of liquid dripping, formation of a uniform film is difficult, and in the case of coating a long member such as a wire, a long dipping bath is required, resulting in an increase in the size of the apparatus There is a problem with that.

  Moreover, in the spray method, since it is difficult for the coating liquid to adhere to the back side of the object to be coated, it is necessary to perform coating while rotating the object to be coated while turning it on the way or in the middle. The task of rotating or flipping is difficult. Further, in the case where the object to be coated is a thin and long member, most of the sprayed coating liquid is detached from the object to be coated and scattered (overspray), and the waste of the coating liquid is increased.

  The coating method disclosed by the present specification is a method of applying a coating to the surface of a wire by an electrostatic coating method, comprising the step of spraying a coating solution onto the wire using an electrostatic atomization type spray nozzle. Including.

  In addition, the method for producing a medical wire disclosed by the present specification is a method for producing a medical wire by applying a coating on the surface of a wire by an electrostatic coating method, in which a coating solution is used as an electrostatic atomization type. Spraying the wire using the spray nozzle of

  As described above, according to the method of performing electrostatic coating on a wire using an electrostatic atomization type nozzle, a uniform film can be formed without the problem of liquid dripping as in the dipping method. In addition, a long dipping bath is unnecessary, and an increase in size of the apparatus can be avoided.

  In addition, as compared with a spray method using an air atomization type spray gun, the process can be simplified as much as it is not necessary to rotate and reverse the wire. In addition, since there is almost no overspray in the electrostatic atomization type, waste of the coating solution can be significantly reduced.

  Furthermore, since it becomes possible to perform coating processing by a continuous system, it can respond easily also to a long wire.

  According to the technology disclosed by the present specification, a coating layer of good quality can be efficiently formed on the entire surface of the wire.

Schematic of the film-forming line in the embodiment In the embodiment, a schematic view showing a droplet of the coating solution sprayed from the nozzle moving along the electric line of force and adhering to the core wire. Cross section of medical wire

  Embodiments will be described with reference to FIGS. 1 to 3. The medical wire 10 of the present embodiment is a member used as a guide wire for a medical instrument such as an endoscope, and as shown in FIG. 3, a core wire 11 (corresponding to a wire) and a surface of the core wire 11. And a coating layer 12 for covering the The core wire 11 is a single wire made of stainless steel. The coating layer 12 is formed by coating the surface of the core wire 11 with a fluorine-based coating solution.

  As shown in FIG. 1, the film forming line 20 for applying the coating to the core wire 11 includes a unwinding roll 21 for delivering the core wire 11, a winding roll 22 for winding the core wire 11 after coating, and the unwinding roll 21. And a film forming apparatus 31 disposed between the take-up roll 22 and the film forming apparatus. The film forming apparatus 31 includes a film forming chamber 32, a spray nozzle 33 provided inside the film forming chamber 32, and a liquid supply unit 34 connected to the spray nozzle 33.

  The spray nozzle 33 is a nozzle used for spraying the coating liquid 37 by electrostatic coating. In electrostatic coating, there are two methods for atomizing the coating liquid, and one is a method (electrostatic atomizing type) for atomizing using the attraction and repulsive force of the charged coating liquid, One is a method of atomizing the coating liquid by mechanical force, for example, compressed air or high pressure applied to the coating liquid from a spray gun and atomizing it (air atomization type, airless atomization type), and giving an electric charge thereto. . In the present embodiment, an electrostatic atomization type nozzle is used as the spray nozzle 33.

  The liquid supply unit 34 includes a storage container 35 in which the application liquid 37 is stored, and a liquid delivery pipe 36 connecting the storage container 35 and the spray nozzle 33. The application liquid 37 in the storage container 35 is sent to the spray nozzle 33 at a set flow rate by a liquid sending device (not shown) such as a pump.

  The core wire 11 delivered from the unwinding roll 21 passes through the inside of the film forming chamber 32 and is taken up by the take-up roll 22. The core wire 11 is earthed by being grounded. An internal electrode (not shown) is provided inside the spray nozzle 33, and an electrostatic field is formed between the internal electrode and the core 11 (earth electrode). The coating liquid 37 is charged inside the spray nozzle 33, atomized at the tip of the nozzle, and sprayed onto the core 11 passing through the inside of the film forming chamber 32. The particles of the sprayed coating liquid 37 move along the electric lines of force shown by broken lines in FIG. 2 and wrap around and adhere not only to the portion of the core 11 facing the spray nozzle 33 but also to the opposite side. Thereby, the uniform coating layer 12 can be formed on the entire surface of the core wire 11.

  The coated core wire 11 taken up on the take-up roll 22 is cut into a predetermined length to complete the medical wire 10.

  As described above, when the core wire 11 is coated using the electrostatic atomizing spray nozzle 33, a uniform film can be formed without the problem of liquid dripping as in the dipping method. In addition, a long dipping bath is unnecessary, and an increase in size of the apparatus can be avoided.

  In addition, as compared with the spray method using an air atomization type spray gun, the process can be simplified as much as it is not necessary to rotate and reverse the wire. In addition, since there is almost no overspray in the electrostatic atomization type, waste of the coating solution can be significantly reduced.

  Furthermore, since the coating process can be performed in a continuous manner, even when the long medical wire 10 is required, it can be easily coped with.

[Test example]
Hereinafter, the present invention will be described in more detail by way of test examples. In this test example, the surface of the wire was coated using a film forming apparatus equipped with an electrostatic atomization type spray nozzle.

<Devices used>
As a film forming apparatus, a small-sized coater rCoater (registered trademark) manufactured by Asahi Sanac Corporation was used. As an electrostatic atomization type spray nozzle, an electrostatic attraction nozzle AES100 manufactured by Asahi Sanak Co., Ltd. was used. YSP 201 manufactured by YMC was used as a liquid transfer device.

<Materials used>
As a substrate, a stainless steel wire having a diameter of 0.46 mm and a length of 150 mm was used. As a coating solution, a fluorine-based resin containing PTFE (polytetrafluoroethylene) as a main component was diluted with NMP (N-methylpyrrolidone) or the like and used.

<Deposition condition>
The wire was stretched in the film forming chamber of the film forming apparatus, and the coating solution was applied to the surface of the wire while scanning the spray nozzle along the wire, and then dried to form a coating layer. The film formation conditions are as follows.
Applied voltage: 5.0 kV
Injection distance: 10.0 mm
Discharge rate: 0.05 ml / min
Nozzle movement speed: 130 mm / s
When the target film thickness of the coating layer is 5 μm, the applied voltage: 1.0 to 30.0 kV, the ejection distance: 1 to 120 mm, the ejection amount: 0.01 to 1.0 ml / min, It is considered that a good coating layer can be formed at a nozzle moving speed of 1 to 600 mm / s.

<Result>
It was confirmed that a good coating layer having a thickness of 3 to 4 μm was formed on the entire surface of the wire.

Other Embodiments
The art disclosed by the present specification is not limited to the embodiments described above with reference to the drawings and the drawings, and includes, for example, various aspects as follows.
(1) In the above embodiment, the core wire 11 is made of stainless steel, but the material of the wire is not limited to that of the above embodiment, and any material having conductivity such as metal or conductive resin may be used.

(2) In the said embodiment, although the core wire 11 was a single wire, the strand wire in which several strand wire was twisted together may be sufficient as a wire.

(3) In the above embodiment, the coating liquid contains a fluorine-based resin, but the type of the coating liquid is not limited to that of the above embodiment, and is suitable for electrostatic coating using an electrostatic atomizing nozzle. As long as it is

(4) In the above embodiment, an example in which the coating is performed by the continuous film forming line 20 has been described, but the wire material cut in advance to a predetermined length is coated by the batch film forming apparatus. I don't care.

(5) In the above embodiment, an example was shown in which the coating was performed using one spray nozzle 33 installed immediately above the wire, but the coating is performed using a plurality of spray nozzles installed at a fixed interval. It does not matter.

(6) In the above embodiment, the application liquid sprayed from the spray nozzle 33 is scattered from the upper side to the lower side of the core wire 11, but the wire may be sprayed from different directions. .

11 ... core wire (wire)
33 ... spray nozzle 38 ... coating liquid

Claims (2)

A method of applying a coating to the surface of a wire by electrostatic coating,
A coating method comprising the step of spraying a coating solution onto the wire using an electrostatic atomization type spray nozzle. A method of manufacturing a medical wire by applying a coating on the surface of a wire by electrostatic coating,
A method for producing a medical wire, comprising the step of spraying a coating solution onto the wire using an electrostatic atomization type spray nozzle.

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