JPH05273445A - High-strength image fiber for medical treatment - Google Patents

Abstract

PURPOSE:To obtain the high-strength image fiber by combination use of a polyimide resin. CONSTITUTION:This image fiber is constituted by forming a thin layer 2 of the polyimide resin having 0.5 to 10mum thickness on the image fiber 1 for image transmission, and further forming a carbon black-contg. silicone resin layer 3 thereon. While the strength is low with only the silicone resin layer 3, the strength is improved by the thin layer 2 of the polyimide resin. Many times of coating are necessary to attain a prescribed thickness with only the thin layer 2 of the polyimide resin, but the thin coating is merely necessitated, and therefore there are no problems in the production process in using the polyimide resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention relates to an image fiber,
In particular, the present invention relates to a medical image fiber having improved breaking strength.

[0002]

2. Description of the Related Art Silicone resin is used as a coating material for image fibers, especially medical image fibers. The reason for this is that in the case of a general UV resin as a coating material for optical fibers, many of its reaction initiators have toxicity and are not suitable for medical use.

[0003]

However, the surface hardness and elongation at break of the silicone resin as a material are not sufficient as compared with the UV resin. Further, since the silicone resin is transparent, it is necessary to mix carbon black for the purpose of shielding light required for the image fiber.
The fact is that this damages the glass fiber surface and further reduces the fiber strength.
Therefore, an image fiber having a coating layer of polyimide resin has been proposed to meet the demand for high strength. However,
Since the polyimide resin is a solvent type, the coating thickness per time is at most 5 to 10 μm, so that there is a problem in the manufacturing method that the coating must be repeated many times in order to achieve the predetermined 40 to 70 μm.

[0004]

The present invention has been made in view of the above points, and the invention according to claim 1 is characterized in that a polyimide resin thin layer is sequentially formed on a glass fiber for image transmission, It is in an image fiber provided with a silicone resin layer. As a manufacturing method, a typical dip method can be adopted. Specifically, the image fiber base material is melt-drawn to form a fiber, and the obtained image fiber is passed through a polyimide resin solution and then dried by heating to form a polyimide resin coating layer having a thickness of 0.5 to 10 μm.
Subsequently, the mixture is passed through a silicone resin solution containing carbon and then cured by heating to form a silicone resin coating layer having a thickness of 30 to 60 μm.

[0005]

Function The strength problem of the silicone resin is covered by the combined use with the polyimide resin. Further, since the polyimide resin has a thickness of about 0.5 to 10 μm, which is a thickness that can be applied once, it is not necessary to repeatedly coat the polyimide resin, and the manufacturing method is simple.

[0006]

1 is a sectional view of an image fiber according to the present invention. In the figure, 1 is a silica-based image fiber having a diameter of 500 μm, 2 is a 5 μm-thick polyimide resin layer formed on the silica-based image fiber 1, and 3 is 35.
A silicone resin coating layer containing carbon black having a thickness of μm. 20 mmφ of the image fiber thus obtained
The mandrel (maximum bending strain: 2.5%) was passed through a bending proof device in which 8 pieces were arranged, and the average survival length was 193 m. By the way, UV resin, silicone resin, and silicone resin containing carbon black are 40 μm each on a silica-based image fiber with a diameter of 500 μm.
When three kinds of image fibers that were made thick were manufactured and the same test as above was performed, the average survival length was 1 each.
It was 98 m, 69 m and 42 m. As is clear from this, the image fiber of the present invention has substantially the same strength as that coated with UV resin.

[0007]

In the image fiber according to the present invention, the double-layer coating of the polyimide resin and the silicone resin suppresses the deterioration of the strength characteristics due to only the silicone resin layer, and the polyimide resin layer alone has a predetermined thickness. This is an improvement in the manufacturing method in which the coating has to be repeated many times, which is very effective.

[Brief description of drawings]

FIG. 1 is a sectional view of an image fiber according to the present invention.

[Explanation of symbols]

 1 Quartz-based image fiber 2 Thin polyimide resin layer 3 Silicone resin layer containing carbon black

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takashi Tamanuma 1440 Rokuzaki, Sakura City, Chiba Prefecture Fujikura Electric Wire Co., Ltd. Sakura Factory

Claims (2)

[Claims] 1. A medical high-strength image fiber comprising a glass fiber for image transmission and a thin polyimide resin layer and a silicone resin layer sequentially applied on the glass fiber. 2. The polyimide resin coating thin layer has a thickness of 0.5.
The high-strength image fiber for medical use according to claim 1, wherein the image fiber has a thickness of 10 μm.