JPS6057871B2 - medical silicone rubber tube - Google Patents

Description

[Detailed Description of the Invention] Silylon rubber products are currently widely used as materials for medical instruments, particularly for instruments used in living bodies, such as tracheal tubes, catheters, and instruments implanted in living bodies. Mainly used are tubular products such as hair and catheters.

This is due to the fact that silicone rubber has almost no irritating reaction to living organisms, and it is relatively easy to make molded products whose hardness and softness can be adjusted appropriately. In fact, the main uses of silicone rubber are also due to the characteristics of silicone rubber. Although silicone rubber is suitable as a material for medical devices for living bodies due to the above characteristics, it is not without drawbacks.

The main problem is that the surface gives the illusion of being sticky, in other words, it is not slippery, although it varies depending on the composition of the silicone rubber, and as a result, it is easy to attract dust etc. That's true. In membranes, this sticking causes blocking, and in tubes, especially tracheal tubes into which catheters and the like are inserted, poor slippage impedes treatment. Prevention of blocking can be improved to some extent by improving the surface shape, but no good method has been found for the latter. It is easy to understand that powdered lubricants can be used to improve the slippage of pipes, but for example, starches have no effect when exposed to moisture or moisture, and talc and other lubricants have no effect. Inorganic powders have difficulty in peeling off coatings and biological reactions during use, and also have difficulty in heat resistance when disinfection is performed in a dry state.

Recently, many new inorganic materials have been developed, and many of these products include powder materials with excellent lubricity.

The present inventor conducted a comparative study of existing inorganic lubricants and new powder compositions to impart lubricity to silicone rubber pipes, and found that only fine boron nitride powder provides extremely excellent properties for use in silicone rubber pipes. The present invention is based on this knowledge. I. Boron nitride fine powder has recently become known as a heat-resistant and contact-resistant lubricant paint material used in high-temperature areas and as a lubricant material for Aero Breath Spray, but the application and method of the present invention are unknown. It has not been done yet.

In the present invention, for example, in order to form a film of boron nitride fine powder inside a silicone rubber tube, it is sufficient to attach a cotton pad or the like to the tip of a stick, soak the fine powder in it, and thoroughly rub the tube.

If there is a large amount of adhesion, you can wipe off the excess using water and a tampon that does not contain fine powder. Even in this case, the film of fine powder adhering to the silicone rubber surface is not damaged at all.
The membrane can be attached to the outside of the tube by rubbing it with a cotton-like material containing fine powder. Boron nitride adhering to the surface of silicone rubber is more likely to fall off during cleaning than simply rubbing it. desirable in the sense of preventing The silicone rubber tube treated according to the present invention has extremely good sliding properties, and even if the object it comes into contact with is not treated, its slippage will not deteriorate.

Therefore, it is necessary to treat only the required surfaces, but since objects may be arbitrarily combined during use, double-sided coating is sometimes desirable. When using the product of the present invention, the membrane rarely peels off, and no unfavorable biological reactions occur. These effects will become clear in the following examples. Example 1 Medical silicone rubber sheet 150 with hardness of 50 Shore
x 150 x 2 pieces were press-molded using a smooth mold so that the surface became a mirror surface, and immediately the boron nitride, talc powder (200 mesh), and mica powder (250 mesh) were used as samples, and the samples were thoroughly coated with cotton gauze using a tampon. After rubbing, 200℃
Secondary vulcanization was performed in an open air circulation system for 8 hours, then washed with gauze in a 1% detergent solution, and washed with water at 100°C for 3 hours.
The powder was dried to give samples A, B, and C, respectively.

This sample and an untreated sample as a control were held horizontally and placed on a transparent soft vinyl chloride resin sheet 20 x 50 x
0.2 was placed on the vehicle, and the starting index force was measured when the vehicle was moved horizontally with a load of 50y applied.

In order to determine the extent to which the powder film was removed by washing with water, each sample was again washed with gauze in water containing 1% detergent, dried three times at 100°C, and the same test was repeated. The results were as shown in Table 1. Example 2 A sample was prepared using the material of Example-1, and comparative data on hemolysis and degree of hemoglobin denaturation was measured using human blood in order to understand biological reactions.

The hemolysis rate was calculated from the absorbance at a wavelength of 4101 m, and the degree of hemoglobin denaturation was calculated from the absorbance at a wavelength of 654 nm and 585 m.

There was almost no difference between silicone rubber treated with boron nitride and untreated silicone rubber. Example 3 Intratracheal catheter made of silicone rubber with an inner diameter of 1079 mm! Using a tampon, thoroughly rub boron nitride and talc powder into the inner cavity of the 300 m long 12'' curvature, heat at 200°C for 4 hours, wash with water, dry, and insert a soft vinyl chloride catheter into a 6 wn diameter catheter. When the object was inserted from one end, the untreated control stopped due to adhesion at about 9 cm from the entrance and could not be inserted any further.

On the other hand, all the processed ones were able to be inserted to the other end. Next, wash it with water using a cleaning brush, and then heat it to 121℃.
When we conducted a similar test after heat sterilizing for 30 minutes using an autoclave, we found that the talc treatment was about 17C from the entrance!
It stopped at rl due to adhesion, and the boron nitride treatment that was allowed to enter beyond that point was able to easily pass through to the other end.

Claims (1)

[Claims] 1. A medical silicone rubber tube comprising a thin layer of fine boron nitride powder formed on the inner or outer surface or both surfaces of the tube. 2. The medical silicone rubber tube according to claim 1, wherein the thin layer of boron nitride fine powder is formed by rubbing a carrier impregnated with the fine powder.