JP2021041137A - Cable and medical hollow tube - Google Patents

Abstract

To provide a cable and a medical hollow tube capable of achieving slipperiness, adhesion and wiping resistance at a high level and in a well-balanced manner in the coat thereof.SOLUTION: Provided is a cable comprising a sheath, and a coat covering a circumference of the sheath and provided in close adhesion with the sheath, and in which the coat is formed from a rubber composition containing a rubber component and fine particles, a static friction factor on a surface of the coat is 0.5 or less, and when a number of the fine particles per unit area is measured at any plurality of locations on the surface of the coat, a number distribution calculated by a formula (Nmax - Nmin)/(Nmax + Nmin)×100 from the maximum value Nmax and the minimum value Nmin of the number is 5% or less.SELECTED DRAWING: Figure 1

Description

The present invention relates to cables and hollow medical tubes.

Japanese Patent Application Laid-Open No. 2008-287 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2018-23758 (Cited Document 2) can be provided with stable slidability without applying a lubricant to the surface. Techniques for medical coating compositions are described.

Japanese Unexamined Patent Publication No. 2008-287 Japanese Unexamined Patent Publication No. 2018-23758 (Cited Document 2)

A sheath made of an insulating member is formed on the surface of the cable. It is desired that this sheath is not sticky and has good slipperiness (sliding property). On the other hand, the end of the cable is processed to attach a protective member such as boots to the sheath with an adhesive. Here, in a cable to which a protective member is attached, for example, when the end of the cable is bent, the coating film formed on the surface of the sheath may peel off and the protective member may come off from the cable. That is, the cable is required to have no stickiness on the surface of the cable, have good slipperiness, and the coating film formed on the surface of the sheath is difficult to peel off.

Further, in the medical hollow tube, a coating is provided on the outer surface and the inner surface of the hollow tube body. Similar to the cable, this coating is also required to have good slipperiness and the coating formed on the surface of the hollow tube body is not easily peeled off.

On the other hand, cables and hollow medical tubes need to be kept clean by wiping the surface with alcohol from the viewpoint of hygiene. Therefore, the coating film is required to have high wiping resistance so that the slipperiness can be maintained high even when the coating film is repeatedly wiped with a chemical or the like.

Therefore, an object of the present invention is to provide a technique for developing a high level of slipperiness and wiping resistance in a coating film.

According to one aspect of the invention
With the sheath
A coating film that covers the periphery of the sheath and is provided in close contact with the sheath is provided.
The coating film is formed of a rubber composition containing a rubber component and fine particles, and has a coefficient of static friction on the surface of the coating film of 0.5 or less.
When the number of the fine particles per unit area is measured at any plurality of locations on the surface of the coating, the formula (N _max −N _min ) / (N _{max ) is derived from the maximum value N max} and the minimum value N _{min of the number.} The number distribution calculated by + N _min ) × 100 is 5% or less.
Cables are provided.

According to another aspect of the invention
Hollow tube body and
A coating film that covers at least one of the inner surface and the outer surface of the hollow tube body and is in close contact with the hollow tube body.
With
The film is formed of a rubber composition containing a rubber component and fine particles, and the coefficient of static friction on the surface of the film is 0.5 or less.
When the number of the fine particles per unit area is measured at any plurality of locations on the surface of the coating film, the formula (N _max −N _min ) / (N _{max ) is derived from the maximum value N max} and the minimum value N _{min of the number.} A medical hollow tube is provided in which the number distribution calculated by + N _{min) × 100 is 5% or less.}

According to the present invention, slipperiness and wiping resistance can be exhibited at a high level in the coating film.

FIG. 1 is a cross-sectional view perpendicular to the length direction of the cable according to the embodiment of the present invention. FIG. 2A is a diagram schematically showing a probe cable that can be connected to an ultrasonic imaging device. FIG. 2B is a cross-sectional view of the probe cable along the line AA of FIG. 2A. FIG. 3A is a cross-sectional view schematically showing the surface of the coating film in the cable according to the embodiment of the present invention. FIG. 3B is a cross-sectional view schematically showing the surface of the coating film in the cable of the comparative form of the present invention. FIG. 4A is a cross-sectional view of a medical hollow tube provided with an outer coating on the outer surface of the hollow tube body. FIG. 4B is a cross-sectional view of a medical hollow tube provided with an inner coating on the inner surface of the hollow tube body. FIG. 4C is a cross-sectional view of a medical hollow tube provided with an outer coating and an inner coating on the outer surface and the inner surface of the hollow tube body, respectively. FIG. 5 is a diagram illustrating a method of preparing an evaluation sample for evaluating the adhesion strength between the sheath and the coating film. FIG. 6 is a diagram schematically showing a measurement method for measuring tensile shear strength using an evaluation sample. FIG. 7 is a diagram schematically showing a bending resistance test of a probe cable. FIG. 8 is a diagram for explaining a wiping test method. FIG. 9 is a diagram showing a change in the coefficient of static friction of the coating film depending on the number of times of wiping. FIG. 10A is an SEM image of the coating surface of the cable of Example 1. FIG. 10B is an SEM image of a cross section of the coating in the cable of Example 1. FIG. 11A is an SEM image of the coating surface of the cable of Comparative Example 1. FIG. 11B is an SEM image of a cross section of the coating film in the cable of Comparative Example 1. FIG. 12 is a diagram showing a surface profile of the coating film of Example 1. FIG. 13 is a diagram showing a surface profile of the coating film of Comparative Example 1.

<Knowledge by the present inventors>
First, the findings obtained by the present inventors will be described.

For example, in an ultrasonic imaging device, which is a medical device, an ultrasonic probe is connected to a cable, and an inspection is performed by moving the ultrasonic probe on a human body. At this time, if the cable connected to the ultrasonic probe is sticky, the cable may be caught by the cables coming into contact with each other or the cable touching the clothes of the inspector. As a result, it becomes difficult to move the ultrasonic probe smoothly, and the handleability of the medical device may be impaired.

Conventionally, polyvinyl chloride (PVC) has been used as a sheath forming material from the viewpoint of ensuring the slipperiness of the cable. However, in PVC, the sheath tends to change in quality, such as the sheath changing color as the cable is used for a long period of time.

For this reason, as a sheath material, silicone rubber having excellent heat resistance and chemical resistance has been studied instead of PVC. However, since the sheath formed of silicone rubber is easily sticky (has a so-called tack), its slipperiness (sliding property) tends to be low.

Therefore, in order to improve the slipperiness of the cable, it has been proposed to provide a coating having a small coefficient of static friction on the surface of the sheath formed of silicone rubber. As a film having a small coefficient of static friction, a film formed of a rubber composition containing fine particles and having fine irregularities on the surface due to the fine particles has been studied.

However, according to the study by the present inventors, it has been found that the cable provided with the above-mentioned coating has the following problems, although the slipperiness can be obtained.

One is that sufficient adhesion strength cannot be ensured between the coating film and the sheath. When the cable is used, for example, as a probe cable, boots may be attached to the end as a protective member. At this time, the boot is attached to the coating formed on the outermost surface of the cable via an adhesive. However, if bending pressure is applied to the boot attached to the cable, probably because the adhesion strength between the sheath and the coating is low, peeling may occur at the interface between the sheath and the coating, and the boot may come off from the cable.

The other is that the film has low resistance to wiping. Cables for medical use are wiped with rubbing alcohol or the like to keep the surface clean, and are used repeatedly. However, according to the study by the present inventors, the coefficient of static friction of the film increases as the number of times of wiping increases, probably because the uneven state of the film surface changes due to repeated wiping, and the desired slipperiness can be obtained. It turned out to be difficult. That is, in the coating film, the slipperiness may not be maintained high over a long period of use.

As a result of examining the above problems, the present inventors have found that the factor that deteriorates various properties of the coating film is bubbles existing in the coating film. Bubbles are generated when the liquid material forming the film is cured. When these air bubbles are present on the surface in contact with the sheath of the coating film, the adhesion area of the coating film with the sheath is reduced, and the adhesion strength is lowered. On the other hand, if air bubbles are present on the surface of the coating film, depressions (recesses) may be formed, and the edges of such recesses become caught during wiping. Therefore, the film is easily scraped at the time of wiping, and the slipperiness is easily lowered by repeating wiping. Further, the air bubbles hinder the dense distribution of the fine particles on the surface of the coating film, and have a great influence on the uneven state of the coating film surface and, by extension, various characteristics due to the unevenness.

From these points, the present inventors have studied to reduce the bubbles (voids) existing in the coating film by suppressing the generation of bubbles when the coating film is cured and formed. We have found that adhesion and wiping resistance can be achieved at a high level in a well-balanced manner.

The present invention has been made based on the above findings.

<One Embodiment of the present invention>
Hereinafter, an embodiment of the present invention will be described with reference to a medical device cable that can be connected to the medical device as an example. In addition, in all the drawings for explaining the embodiment, in principle, the same members are designated by the same reference numerals, and the repeated description thereof will be omitted. Further, in order to make the drawing easy to understand, hatching may be added even if it is a plan view.

[cable]
As shown in FIG. 1, the medical device cable 10 of the present embodiment (hereinafter, also simply referred to as a cable 10) is configured by sequentially laminating a sheath 13 and a coating 14 on the outer periphery of a cable core 11.

(Cable core)
The cable core 11 is configured by twisting a plurality of electric wires 11a and covering the outer periphery thereof with a shield 12. As the electric wire 11a, an electric wire in which the outer periphery of a conductor made of a single wire or a stranded wire such as a pure copper wire or a tin-plated copper wire is coated with an insulator, a coaxial cable, an optical fiber, or the like can be used. As the shield 12, for example, a braided wire or the like can be used.

(sheath)
The sheath 13 is formed of an insulating material and is provided so as to cover the cable core 11. The insulating material is not particularly limited as long as it can be used for the sheath 13, and for example, silicone rubber, polyethylene, chlorinated polyethylene, chloroprene rubber, polyvinyl chloride (PVC) and the like can be used. Of these, silicone rubber and chloroprene rubber are preferable from the viewpoint of chemical resistance and heat resistance. Even if general compounding agents such as various cross-linking agents, cross-linking catalysts, anti-aging agents, plasticizers, lubricants, fillers, flame retardants, stabilizers, and colorants are added to the insulating material forming the sheath. Good.

(Coating)
The coating 14 is provided so as to cover the sheath 13. The coating film 14 is formed of a rubber composition containing fine particles and a rubber component, and is composed of fine particles dispersed in the rubber component. Concavities and convexities derived from fine particles are formed on the surface of the coating film 14. Due to this unevenness, the contact area can be reduced when the coating film 14 and other members come into contact with each other, and the coefficient of static friction of the coating film 14 is made smaller than the coefficient of static friction originally possessed by the rubber component constituting the coating film 14. be able to. According to such a coating film 14, the slipperiness of the cable 10 can be improved as compared with the case where the sheath 13 is present on the surface.

The coefficient of static friction of the coating film 14 is not particularly limited, but is preferably 0.5 or less from the viewpoint of imparting desired slipperiness to the cable 10.

Further, since the fine particles are densely distributed on the surface of the coating film 14, the coating film 14 has high wiping resistance. Specifically, the cotton cloth containing rubbing alcohol to the surface of the film 14 by contact with a pressure ^{2 × 10 -3 MPa~4 × 10 -3} MPa, speed 200 mm / min The surface of the coating 14 to 300 mm / When the test of wiping with a minute is repeated 20,000 times, the difference (absolute value) of the static friction coefficient of the coating film 14 before and after the test can be 0.1 or less, preferably 0.05 or less. That is, even when the coating film 14 is repeatedly wiped off, the surface unevenness can be maintained and the slipperiness due to the unevenness can be maintained for a long period of time.

Further, in the present embodiment, as will be described in detail later, the generation of bubbles when the rubber composition is cured is suppressed, so that the bubbles (voids) existing in the coating film 14 can be reduced. Therefore, it is possible to suppress a decrease in the area due to air bubbles (voids) on the surface of the coating film 14 on the sheath 13 side. As a result, the contact area of the coating film 14 with the sheath 13 can be maintained large, and the adhesion strength between the coating film 14 and the sheath 13 can be made higher than in the case where air bubbles are present. Specifically, the adhesion strength between the coating film 14 and the sheath 13 can be set to 0.3 MPa or more. The upper limit of the adhesion strength between the sheath 13 and the coating film 14 is not particularly limited, but is substantially about 0.7 MPa.

Further, since the bubbles can be reduced on the surface side of the coating film 14, the depression due to the bubbles can be reduced. Since fine particles cannot exist at the depressed portion, when the depressed portion is formed, the area where the fine particles can be distributed decreases. Therefore, the number of fine particles distributed on the surface of the coating film 14 is reduced. That is, the distribution of fine particles becomes sparse. Moreover, since the plurality of fine particles are likely to aggregate to form coarse aggregated particles, it is difficult to obtain desired unevenness. On the other hand, by reducing the depression, the number of fine particles occupying the surface of the coating film 14 can be increased, the aggregation of fine particles can be suppressed, and the fine particles can be distributed more densely.

Further, since the fine particles are densely distributed on the surface of the coating film 14, the number of fine particles varies little depending on the region. Specifically, when the number of fine particles per unit area is measured at an arbitrary plurality of locations on the surface of the coating film 14, the equation ((N _max −N _min )) _{is derived from the maximum value N max} and the minimum value N _{min of the number of fine particles.} The number distribution calculated by / (N _max + N _min )) × 100 is preferably 5% or less. The smaller the number distribution, the smaller the bias in the number of fine particles, and the smaller the variation in the distribution of the fine particles.

Further, on the surface of the coating film 14, it is preferable that there are few voids due to air bubbles, and it is preferable that there are substantially no voids. Specifically, when observed with an electron microscope SEM under 1000 times conditions, the number of voids having a size of 1 μm or more per unit area is preferably 5/40 μm square or less, and the size is preferable. It is more preferable that there are substantially no voids of 10 μm or more.

On the surface of the coating film 14, it is preferable that there are few recessed recesses due to voids and many convex portions raised by fine particles. That is, it is preferable that the surface of the coating film 14 has surface irregularities formed mainly from the convex portions.

The thickness of the coating film 14 is not particularly limited, but is preferably 3 μm or more and 100 μm or less. By setting the thickness to 3 μm or more, a predetermined wiping resistance can be imparted to the coating film 14. Further, when the thickness is 100 μm or less, the flexibility and flexibility of the cable 10 can be maintained high.

(Rubber composition for film formation)
Next, the rubber composition forming the coating film 14 will be described.

The rubber composition is a cured product obtained by curing a liquid rubber composition (hereinafter, also referred to as paint) containing liquid rubber, fine particles, a curing catalyst, and if necessary, other additives, and the cured rubber component and fine particles. It is composed including and.

The rubber component is a matrix component that constitutes the coating film 14. Silicone rubber can be used as the rubber component. There are two types of silicone rubber, a condensation reaction type and an addition reaction type, depending on the curing method. Of these, the addition reaction type is preferable. Compared with the condensation reaction type, the addition reaction type silicone rubber is less likely to generate bubbles during curing, and the distribution of fine particles in the coating film 14 can be made more precise.

The addition reaction type silicone rubber is obtained by curing a liquid silicone rubber composition by an addition reaction. The liquid silicone rubber composition contains, for example, _{an organopolysiloxane containing a vinyl group (CH 2} = CH−) and an organohydrogenpolysiloxane having a hydrosilyl group (Si—H). Organopolysiloxane is the base polymer for silicone rubber. Organohydrogenpolysiloxane acts as a cross-linking agent for the base polymer. For example, by mixing a platinum catalyst, the organohydrogenpolysiloxane undergoes a hydrosilylation reaction between the hydrosilyl group and the vinyl group in the base polymer to crosslink and cure the base polymer. The organopolysiloxane and the organohydrogenpolysiloxane are not particularly limited, and conventionally known ones can be used.

Further, chloroprene rubber may be used as the rubber component, and the coating film 14 may be configured to contain chloroprene rubber.

The fine particles form a raised convex portion on the surface of the coating film 14. As the fine particles, it is preferable to use at least one of silicone rubber fine particles, silicone resin fine particles, and silica fine particles. The type of fine particles can be appropriately changed according to the characteristics required for the coating film 14.

Specifically, from the viewpoint of maintaining the uneven shape of the coating film 14 when an object is brought into contact with the coating film 14 and ensuring the slipperiness, it is preferable that the fine particles have a higher hardness than the coating film 14. Specifically, the fine particles preferably have a shore (durometer A) hardness of 1.1 times or more the hardness of the cured product constituting the coating film 14. This is because the higher the hardness of the fine particles, the less likely it is that the fine particles will be deformed by the pressing pressure when an object is brought into contact with the surface of the coating 14, and the uneven shape of the coating 14 can be easily maintained. Since the hardness increases in the order of silicone rubber, silicone resin, and silica, silica fine particles are preferable from the viewpoint of hardness.

On the other hand, from the viewpoint of uniformly distributing the fine particles on the surface of the coating film 14 to form desired surface irregularities, the fine particles preferably have a small mass. This is because if the mass of the fine particles is large, the fine particles settle before the coating material is cured to form the coating film 14, and it becomes difficult to form appropriate irregularities on the coating film 14. In this respect, by reducing the mass of the fine particles, sedimentation is suppressed and it becomes easy to form appropriate irregularities on the coating film. Since the mass increases in the order of silicone rubber, silicone resin, and silica, silicone rubber particles are preferable from the viewpoint of mass.

Further, in the coating film 14, silicone resin fine particles are preferable from the viewpoint of maintaining the uneven shape to ensure slipperiness and facilitating the formation of a desired uneven shape, and achieving both of these.

The content of the fine particles contained in the rubber composition is preferably 10% by mass or more and 60% by mass or less. By setting the content to 10% by mass or more, unevenness can be formed on the surface of the coating film 14, and the coefficient of static friction of the coating film 14 can be reduced to impart desired slipperiness. On the other hand, if the amount of fine particles is excessively large, the strength of the coating film 14 may decrease, but by setting the content to 60% by mass or less, the strength can be maintained while obtaining slipperiness. The content of the fine particles was calculated on the assumption that the coating material was cured with almost no reduction in mass, and indicates the ratio to 100 parts by mass of the cured rubber component.

The size of the fine particles may be appropriately changed according to the thickness of the coating film 14, and is not particularly limited. From the viewpoint of forming desired irregularities on the coating film 14, the average particle size of the fine particles is preferably 1 μm or more and 10 μm or less. Here, the average particle size means that measured by the laser diffraction / scattering method. By setting the average particle size to 1 μm or more, it becomes easy to form appropriate irregularities on the surface of the coating film 14, so that the coefficient of static friction of the coating film 14 can be reduced and the slipperiness can be further improved. Further, by setting the average particle size to 10 μm or less, the mass of the fine particles can be adjusted to an appropriate size, so that precipitation of the fine particles and coating unevenness when the liquid rubber composition is applied can be suppressed. ..

The curing catalyst is not particularly limited as long as it can promote the addition reaction, and for example, platinum or a platinum-based compound may be used.

Other additives may be added as needed. For example, an organic solvent can be used for the purpose of adjusting the viscosity of the paint. Examples of the organic solvent include aromatic hydrocarbon solvents such as toluene and xylene, and aliphatic hydrocarbon solvents such as n-hexane, n-heptane, n-octane, isooctane, nonane, decane, undecane, and dodecane. It can be used alone or in combination of two or more. Further, for example, alcohols such as ethanol and isopropyl alcohol and acetone can be used.

The viscosity of the coating material is not particularly limited, but is preferably 1 mPa · s or more and 100 mPa · s or less from the viewpoint of finely distributing fine particles. Within such a viscosity range, the thickness of the coating film can be appropriately changed. The viscosity was measured at a temperature of 25 ± 2 ° C. using a tuning fork vibration type viscometer (SV-H, manufactured by A & D Co., Ltd.).

Further, for example, from the viewpoint of forming desired irregularities on the surface of the coating film, it is preferable to add fumed silica having a particle size smaller than that of the fine particles to the rubber composition. Fused silica is obtained by calcining silicon chloride as a raw material at a high temperature, and indicates, for example, silica ultrafine particles having an average particle size of primary particles of 10 nm or more and 30 nm or less. Humed silica includes a hydrophilic one having a silanol group (Si-OH) on its surface and a hydrophobic one in which a silanol group on the surface is chemically reacted, and any of them can be used. Fumed silica has excellent dispersibility in paints and contributes to improving the dispersibility of the fine particles in paints. As a result, it is possible to suppress the sedimentation of fine particles in the coating material and to form desired irregularities on the surface of the coating film.

The content of fumed silica is not particularly limited, but is preferably 0.1% by mass or more and 0.5% by mass or less. The content here is calculated on the assumption that the coating material is cured with almost no decrease in mass, as in the case of the fine particles, and indicates the ratio to 100 parts by mass of the cured rubber component.

[Cable manufacturing method]
Next, the method for manufacturing the cable 10 described above will be described.

First, for example, a plurality of electric wires 11a (for example, 100 or more) such as a coaxial cable are bundled together. For example, a braided shield is formed as a shield 12 so as to cover a bundle of a plurality of electric wires. As a result, the cable core 11 is obtained.

Subsequently, a sheath material containing, for example, silicone rubber is extruded so as to cover the surface of the cable core 11 to form the sheath 13.

Subsequently, a paint is applied to the surface of the sheath 13 to form a coating film. The coating method is not particularly limited, and for example, a dipping method, a spray coating method, a roll coating method, or the like may be appropriately selected. Of these, the dipping method is preferable.

The dipping method is, for example, a method of forming a coating film on the surface of the sheath 13 by immersing the wire rod on which the sheath 13 is formed in the paint and pulling it up. According to the dipping method, the thickness of the coating film can be made uniform, so that the film thickness of the coating film 14 can be made uniform in the length direction. Moreover, by adjusting the pulling speed of the cable 10, the distribution of fine particles in the coating film 14 can be controlled more precisely. This point will be described below.

In the dipping method, when the cable 10 is pulled up from the liquid surface of the paint, the paint adheres to the surface of the cable 10. When this paint adheres to the surface of the cable 10, fine particles may move in the coating film and self-arrange. This self-arrangement allows the fine particles to be densely distributed on the surface of the coating film. Then, the slower the pulling speed of the cable, the more time can be secured for the self-arrangement of the fine particles, and the dense distribution state of the fine particles can be reproduced more stably.

Specifically, from the viewpoint of finely distributing fine particles, the pulling speed of the cable 10 is preferably 10 m / min or less, and more preferably 5 m / min or less. On the other hand, from the viewpoint of productivity, it is preferably 1 m / min or more. That is, by setting the value to 1 m / min or more and 5 m / min or less, the distribution of fine particles on the surface of the coating film can be made more precise while maintaining productivity.

Subsequently, the coating film is dried and cured by heating to form a coating film 14 having predetermined surface irregularities. The heating temperature is not particularly limited, but may be, for example, 120 ° C to 200 ° C.

From the above, the cable 10 of the present embodiment is obtained.

[Probe cable]
As shown in FIG. 2A, for example, the probe cable 20 has an ultrasonic probe terminal 23 (hereinafter, also simply referred to as a terminal 23) attached to one end of the cable 10 and a protective member 22 for protecting the terminal 23. A connector 24 is attached to the other end to form a configuration. The terminal 23 is connected to, for example, an ultrasonic probe, and the connector 24 is connected to, for example, the main body of an ultrasonic imaging device. The protective member 22 is a so-called boot, and is attached on the coating film 14 so as to cover the coating film 14 via the adhesive layer 21 as shown in FIG. 2B. The adhesive layer 21 is formed, for example, from a silicone-based adhesive or an epoxy-based adhesive.

<Effect of this embodiment>
According to this embodiment, one or more of the following effects are exhibited.

(A) In the cable 10 of the present embodiment, a coating film 14 formed of a rubber composition containing a rubber component and fine particles is provided on the surface of the sheath 13. At this time, an addition reaction type silicone rubber is used as the rubber component. According to the addition reaction type silicone rubber, the number of bubbles generated during the curing reaction can be reduced as compared with the condensation reaction type. As a result, it is possible to suppress the generation of voids derived from air bubbles on the surface of the coating film 14 in contact with the sheath 13. As a result, the area where the coating film 14 comes into contact with the sheath 13 can be maintained without being reduced, and high adhesion between the coating film 14 and the sheath 13 can be ensured. Further, before the formation of the coating film 14, a special layer for improving the adhesion strength between the coating film 14 and the sheath 13 (for example, an adhesion reinforcing layer made of a primer, a silane coupling agent, etc., a flame treatment exposed to a flame for a short time, etc. Alternatively, a surface modification layer by a method such as plasma treatment in which gas is ionized or radicalized to collide with the surface, corona treatment in which components in the air are ionized and exposed to atmospheric discharge, etc.) is applied to the surface of the sheath 13. The adhesion strength between the sheath 13 and the coating film 14 can be set to 0.30 MPa or more without forming. However, it is not excluded to provide the above-mentioned special layer in order to further increase the strength. Further, according to the addition reaction type silicone rubber, since the voids in the film are also reduced, the effect of improving the strength of the film itself can be expected.

(B) Further, since the generation of voids on the surface of the coating film 14 can be suppressed, the number of fine particles occupying the surface of the coating film 14 can be increased and the aggregation of fine particles can be suppressed, and the surface of the coating film 14 can be suppressed. Fine particles can be distributed more precisely. As a result, desired unevenness can be formed on the surface of the coating film 14, so that the coefficient of static friction of the coating film 14 can be made smaller than that of the sheath 13, and high slipperiness can be realized.

(C) Moreover, since there are few depressions due to voids on the surface of the coating film 14, when the surface of the coating film 14 is repeatedly wiped with a cotton cloth or the like, the cotton cloth is prevented from being caught by the edge of the depression and damaging the coating film 14. Can be done. Therefore, even when the wiping is repeated, the coefficient of static friction can be kept small, and high wiping resistance can be realized. Specifically, the cotton cloth containing rubbing alcohol to the surface of the film 14 by contact with a pressure ^{2 × 10 -3 MPa~4 × 10 -3} MPa, speed 200 mm / min The surface of the coating 14 to 300 mm / When the test of wiping with a minute is repeated 20,000 times, the difference (absolute value) of the static friction coefficient of the coating film 14 before and after the test can be 0.1 or less, preferably 0.05 or less.

(D) Further, the coating film 14 is preferably formed by a dipping method using a paint containing liquid rubber and fine particles. According to the dipping method, when the cable 10 is pulled out from the liquid surface of the paint and the paint is adhered to the surface of the cable 10, the self-arrangement of the fine particles in the paint can be promoted, and the fine particles are made denser on the surface of the coating film. Can be distributed.

(E) Further, in the dipping method, it is preferable that the pulling speed of the cable 10 is 1 m / min or more and 10 m / min or less. By pulling up the cable 10 at such a speed, it is possible to secure a time for self-arrangement of the fine particles and maintain a high productivity of the coating film 14. As a result, the fine particles can be more densely distributed on the surface of the coating film 14.

(F) The coefficient of static friction on the surface of the coating film 14 is preferably 0.5 or less, preferably 0.3 or less, and more preferably 0.22 or less. In the present embodiment, by forming irregularities on the surface of the coating film 14, the coefficient of static friction on the surface of the coating film 14 can be made smaller than the coefficient of static friction originally possessed by the rubber component constituting the coating film 14. It can be 5 or less. By setting such a friction coefficient, it is possible to realize a high slipperiness so that the cables 10 do not get caught when they come into contact with each other.

(G) Since the fine particles are densely distributed on the surface of the coating film 14, the number of fine particles distributed at each of a plurality of arbitrarily selected locations on the surface is not greatly separated, and the number of fine particles does not vary widely. Specifically, when the number of fine particles per unit area is measured at an arbitrary plurality of locations on the surface of the coating film 14, the number distribution calculated from _{the maximum value N max} and the minimum value N _{min of the number ((N max).} −N _min ) / (N _max + N _min )) × 100 is preferably 5% or less. By densely and uniformly distributing the fine particles on the surface of the coating film 14 in this way, the slipperiness and wiping resistance of the coating film 14 can be further enhanced.

(H) On the surface of the coating film 14, the number of voids having a size of 1 μm or more per unit area is preferably 5/40 μm square or less, and the voids having a size that can be measured with an electron microscope are substantially. It is more preferable that it does not exist in. By reducing the number of voids, the fine particles can be distributed more densely, so that the slipperiness and wiping resistance of the coating film 14 can be further increased.

(I) In the coating film 14, since the concave portion due to the depression can be suppressed, the surface unevenness can be formed mainly by the convex portion due to the fine particles. Thereby, the wiping resistance can be increased. Hereinafter, this point will be specifically described.

For example, as shown in FIG. 3B, when the coating film 14'is formed of a condensation reaction type silicone rubber, voids 34 derived from bubbles are formed in the coating film 14'. If the gap 34 is present on the surface, it becomes a depression 33 (recess 33). In such a coating 14', when wiping with a cotton cloth, the cotton cloth is easily caught by the edge of the opening of the depression 33. When the cotton cloth is caught, the coating film 14'is scraped off, and by repeating this, the fine particles 31 are detached from the coating film 14'and the convex portion 32 of the coating film 14'is gradually reduced. As a result, the coefficient of static friction of the coating film 14'cannot be kept small, and the slipperiness is gradually impaired.

On the other hand, as shown in FIG. 3A, the number of convex portions 32 due to the fine particles 31 can be increased by suppressing the formation of depressions due to voids on the surface of the coating film 14. According to such a coating film 14, although the surface is uneven, deep depressions are unlikely to be formed, so that it is possible to suppress catching by a cotton cloth, and the static friction coefficient of the coating film 14 is kept small even when it is repeatedly wiped. be able to. That is, the wiping resistance can be made higher.

The fine particles 31 preferably have a hardness higher than that of the rubber component forming the coating film 14. According to such fine particles 31, it is easy to maintain the uneven shape of the coating film 14, and a desired slipperiness can be realized.

As the (k) fine particles 31, it is preferable to use at least one of silicone resin fine particles, silicone rubber fine particles, and silica fine particles. According to the silica fine particles, the hardness is high, so that it is easy to secure the slipperiness. Further, according to the silicone rubber fine particles, since the mass is relatively small, it is difficult to settle when the paint is applied, and it is possible to form appropriate surface irregularities. According to the silicone resin fine particles, since both the hardness and the mass are between the silicone rubber fine particles and the silica fine particles, it is easy to form a desired uneven shape, and it is easy to maintain the uneven shape and secure slipperiness.

(L) Further, it is preferable that the rubber composition further contains fumed silica. According to fumed silica, since the sedimentation of fine particles in the coating material can be suppressed, it is possible to form a film having a high level of slipperiness, adhesion and wiping resistance in a well-balanced manner.

(M) In the probe cable 20, the protective member 22 is attached on the coating film 14 at one end of the cable 10 via the adhesive layer 21. In the present embodiment, since the adhesion strength between the coating film 14 and the sheath 13 can be increased, for example, even when bending pressure is applied to the protective member 22, the coating film 14 peels off from the sheath 13 and the protective member 22 comes off. It can be suppressed from being stored. Further, since the coating film 14 having an uneven surface has excellent slipperiness, it is possible to suppress catching even when the probe cables 20 come into contact with each other when moving the ultrasonic probe connected to the probe cable 20, for example. .. Further, since the coating film 14 has excellent wiping resistance, damage and abrasion of the coating film 14 can be suppressed and its slipperiness can be maintained for a long period of time even when the coating film 14 is repeatedly wiped with a cotton cloth. Further, since the coating film 14 formed of silicone rubber is also excellent in chemical resistance and heat resistance, deterioration of the coating film can be suppressed even when it is washed with chemicals such as rubbing alcohol or exposed to heat. ..

<Other Embodiments>
In the above-described embodiment, the case where the probe cable 20 is provided with the coating film 14 has been described, but the present invention is not limited thereto. For example, the above-mentioned coating can be provided on a medical cable (endoscope cable, catheter connection cable, etc.) other than the probe cable 20 and a cabtire cable.

Further, the case where the coating film 14 is provided on the surface of the sheath 13 of the cable 10 has been described, but the present invention is not limited to this, and the coating film 14 can also be applied to a medical hollow tube such as a catheter. Hereinafter, a specific description will be given with reference to the drawings.

FIG. 4A is a cross-sectional view of a medical hollow tube 70 provided with an outer coating 72 on the outer surface 71a of the hollow tube main body 71. FIG. 4B is a cross-sectional view of a medical hollow tube 70 provided with an inner coating 73 on the inner surface 71b of the hollow tube main body 71. FIG. 4C is a cross-sectional view of a medical hollow tube 70 provided with an outer coating 72 and an inner coating 73 on the outer surface 71a and the inner surface 71b of the hollow tube main body 71, respectively.

The medical hollow tube 70 has an outer coating 72 that covers the hollow tube main body 71 and the periphery of the hollow tube main body 71 (outer surface 71a or inner surface 71b, or both sides) and is in close contact with the hollow tube main body 71. And / or an inner coating 73 is provided. The hollow tube main body 71 may be formed of, for example, silicone rubber. The outer coating 72 and / or the inner coating 73 may be composed of the coating 14 described above.

According to such a medical hollow tube 70, since the inner surface and the outer surface are excellent in slipperiness, it is possible to suppress catching when it comes into contact with other members, and when the instrument is inserted into the tube, the instrument is inserted. Can be inserted and removed smoothly.

Next, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples.

[Example 1]
(Cable making)
First, 200 coaxial cables having a diameter of about 0.25 mm were twisted and covered with a braided wire to prepare a cable core. Subsequently, using an extruder, a sheath material was extruded and coated on the outer periphery of the cable core at a speed of 5 m / min to form a sheath having a thickness of 0.8 mm (cable outer diameter of about 8 mm). Silicone rubber (“KE-541-U” manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the sheath material.

Subsequently, a material for forming a film was prepared. In Example 1, an addition reaction type silicone rubber coating agent (trade name: SILMARK-TM, manufactured by Shin-Etsu Chemical Co., Ltd.) is used as a rubber component, and silicone resin fine particles having an average particle diameter of 5 μm (trade name: X) are used as fine particles. -52-1621, manufactured by Shin-Etsu Chemical Co., Ltd.) were prepared respectively. With respect to 100 parts by mass of this rubber component, 120 parts by mass of fine particles, 600 parts by mass of toluene as a solvent for adjusting viscosity, 8 parts by mass of a curing inhibitor (trade name: CAT-TM, manufactured by Shin-Etsu Chemical Industry Co., Ltd.), A curing catalyst (trade name: CAT-PL-2, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) was mixed with 0.3 parts by mass to prepare a coating solution in which the ratio of the silicone resin fine particles to the coating film was 55% by mass. Further, 0.1% by mass of hydrophobic fumed silica (trade name: AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.) was added to the coating solution. The content of the silicone resin fine particles in the coating film was calculated on the assumption that the coating agent cures with almost no mass reduction (almost equivalent to the compounding mass ratio). The composition of the coating solution is shown in Table 1 below.

Subsequently, the surface of the sheath provided on the cable core was cleaned. Then, a cable core provided with a sheath was immersed in the above coating solution by a dip coating method to form a coating film made of silicone rubber on the surface of the sheath. In this embodiment, the pulling speed of the cable core is set to 2 m / min. Then, the coating film was dried and cured at a temperature of 150 ° C. for 10 minutes to form a film having irregularities on the surface. The film thickness of the obtained film was 15 μm.

From the above, the cable of Example 1 was produced.

[Example 2]
In Example 2, the content of the silicone rubber resin particles was changed from 120 parts by mass to 150 parts by mass, and the ratio of the silicone resin fine particles to the coating film was changed to 60.0% by mass. Similarly, a coating solution was prepared to prepare a cable.

[Comparative Example 1]
In Comparative Example 1, a cable was produced using a condensation reaction type silicone rubber coating agent and silicone resin fine particles having an average particle size of 5 μm (trade name: X-52-1621, manufactured by Shin-Etsu Chemical Co., Ltd.). As the coating agent, a condensation reaction type silicone rubber coating agent (trade name: X-93-1755-1, manufactured by Shin-Etsu Chemical Co., Ltd.) containing vinyl oxime silane and a solvent (toluene, n-heptane) is used. There was.

(Evaluation)
For each cable produced above, the coefficient of static friction of the coating and the sheath, the adhesion strength between the coating and the sheath, the bending resistance when the protective member was attached, the wiping resistance of the coating, and the surface unevenness of the coating were evaluated. Hereinafter, each measurement method will be described.

(Static friction coefficient)
First, a cut was made in the sheath portion of the cable produced above in the length direction to remove the contents other than the sheath, and the sheath was opened. A test sheet 1 in which a flat sheet having a length of about 10 cm and a width of about 2.5 cm thus produced is attached to a flat plate, and a sheet 2 in which a flat sheet of 1.5 cm × 1.5 cm square is attached to the flat plate. Prepared. The coated surface of the test sheet 1 or the surface after wiping is brought into contact with the coated surface of the sheet 2 from above so as to face each other, and pushed while applying a load W of 2N from the top of the sheet 2 flat plate. A flat plate with the sheet 2 was pulled horizontally with a pull gauge, and the pulling force (friction force) F was measured. The coefficient of static friction μ was calculated from F = μW. In this example, the coefficient of static friction was calculated for each of the rubber composition forming the film and the rubber composition forming the sheath. Here, the sheet 1 and the sheet 2 were prepared using the cable after the wiping test, and the coefficient of static friction after wiping was measured.

(Adhesion strength)
The adhesion strength between the sheath and the coating was measured based on FIGS. 5 and 6. FIG. 5 is a diagram illustrating a method of preparing an evaluation sample for evaluating the adhesion strength between the sheath and the coating film. FIG. 6 is a diagram schematically showing a measurement method for measuring tensile shear strength using an evaluation sample.

Specifically, first, a sample cable having a length of 100 mm was sampled from the cable produced above. Further, a boot material tube (inner diameter of about 8 mm, thickness of 0.8 mm, length of 100 mm) was prepared, and a cut (slit) was made in the length direction thereof. As shown in FIG. 5, at one end of the sample cable 50, an adhesive 51 was applied to the outer peripheral surface thereof. Subsequently, one end of the sample cable 50 was wrapped with the boot material tube 52 so as to connect the cut 52a, and the sample cable 50 and the boot material tube 52 were adhered to each other. Next, the contents (cable core, etc.) other than the sheath were pulled from the other end of the sample cable 50 to remove the contents (cable core, etc.), and the sheath material tube 53 and the boot material tube 52 were bonded and integrated. Subsequently, a cut was made in the length direction of this adhesively integrated product. At this time, a cut was made in the sheath material tube 53 so as to be continuous with the cut 52a provided in the boot material tube 52. As a result, the sample 54 for evaluating the adhesion strength shown in FIG. 6 was prepared. The same silicone rubber (static friction coefficient: 1.0 or more) was used for the sheath material tube 53 and the boot material tube 52. As the adhesive 51, a commercially available silicone-based adhesive KE-45 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used. The adhesive region at this time was, for example, a length of 10 mm and an outer circumference of 25 mm, and the thickness of the adhesive 51 was about 50 μm to 200 μm. The evaluation sample 54 thus prepared was left in the air at 25 ° C. for 168 hours.

The adhesion strength between the sheath material tube 53 and the coating film was evaluated by measuring the tensile shear strength using the evaluation sample 54. Specifically, as shown in FIG. 6, the sheath material tube 53 and the boot material tube 52 are pulled at a speed of 500 mm / min while grasping the respective ends of the sheath material tube 53 and the boot material tube 52. Thereby, the tensile shear strength was measured, and the adhesion strength between the sheath material tube 52 and the coating film was measured. The location where each tube is gripped is adjusted so that the distance between the gripped portions is 70 mm when each tube is gripped. In this example, when the adhesion strength was 0.30 MPa or more, it was evaluated that there was sufficient adhesion.

(Bending resistance)
The bending characteristics were evaluated from the adhesion of the boots when a boot as a protective member was bonded to one end of the cable with a silicone adhesive KE-45 to prepare a probe cable, and the probe cable was repeatedly bent.

Specifically, it was evaluated as shown in FIG. FIG. 7 is a diagram schematically showing a bending resistance test of a probe cable. First, a load of 500 g is applied to the probe cable 60 to hold the portion of the boot 61 attached to the end of the probe cable so that the probe cable is in a vertical state, and this holding portion is held at a speed of 30 times / minute. The operation of bending left and right by 90 degrees was carried out. Here, this series of bending operations is such that the holding portion is first made into a vertical state, then bent 90 degrees to the left, then returned to the vertical state, then bent 90 degrees to the right, and then returned to the vertical state. Is counted as one time. The total number of bendings was 150,000 or more for the left and right bendings. In this embodiment, if the boot 61 is not peeled or broken when such a bending resistance test is performed, it is determined that the bending resistance is good (◯), while the boot 61 is peeled or broken. If it occurred, it was judged that the bending resistance was poor (x).

(Wipe resistance)
The wiping resistance of the coating film was evaluated by repeatedly wiping the surface of the coating film with a cotton cloth impregnated with rubbing alcohol according to the test shown in FIG. FIG. 8 is a diagram for explaining a wiping test method. Specifically, first, a string 81 was tied to one end of the cable 10, and the string 81 was routed by a pulley 82 or a guide pulley 83 and connected to a rotatable rotary disk 84. The cable 10 was hung and tied a weight 85 to the lower end. As a result, the cable 10 was held so that it could move up and down in the vertical direction by the rotation of the rotating disk 84. Then, a cotton-like gauze cloth (length 50 mm) was wrapped around the surface of the coating film 14 of the cable 10 as a cotton cloth 86. The cotton cloth 86 was previously impregnated with ethanol for disinfection (containing 75% to 80% of ethanol). Then, the cotton cloth 86 wound held to cover wiper holder 87 made of silicone rubber, so that contact with the pressure in the coating 14 of the cotton cloth 86 is ^{2 × 10 -3 MPa~4 × 10 -3} MPa The holder 87 was adjusted to. Subsequently, the cable 10 was reciprocated up and down with respect to the holder 87, so that the surface (coating 14) of the cable 10 was wiped off with the cotton cloth 86 held by the holder 87. In this example, the wiping length was set to 150 mm. Further, the cable 10 was reciprocated 40 to 60 times per minute to set the wiping speed of the surface of the coating film 14 to 200 mm / min to 300 mm / min. Further, the cotton cloth 86 was replaced with a new one every time the cable 10 was reciprocated 500 times with respect to the cotton cloth 86. In this embodiment, the static friction coefficient of the surface of the coating is measured after the wiping operation is performed 20,000 times (10,000 reciprocations), and the difference in the static friction coefficient before and after the test ((<static friction coefficient after the test). >-<Static friction coefficient before test>)) was calculated. When the difference (absolute value) was 0.1 or less, it was evaluated that the coating was less damaged by wiping and the wiping resistance was excellent. As the cotton cloth 86, "Bencot" manufactured by Asahi Kasei Corporation was used.

(Surface unevenness)
The surface unevenness of the coating film was evaluated by observing the surface of the coating film with an electron microscope and evaluating the number of fine particles and voids existing per unit area and the distribution of the number of fine particles.

The number of fine particles and voids per unit area was calculated by observing the surface of the coating with an electron microscope.

Regarding the number distribution of fine particles, first, on the surface of the coating film, an image was taken at a magnification of 1000 times, four regions of 40 μm × 40 μm were arbitrarily selected, the number of fine particles existing in each region was counted, and the number of fine particles per unit area was counted. The number of particles was calculated. Then, out of the numbers in the four locations, the maximum value is N _max and the minimum value is N _min , and the number distribution calculated by the formula ((N _max −N _min ) / (N _max + N _min )) × 100 is calculated. did. In this example, when the calculated value is 5% or less, it is evaluated that the variation in the number of fine particles is small.

(Evaluation results)
The evaluation results are summarized in Table 1. As shown in Table 1, in Examples 1 and 2, it was confirmed that the static friction coefficient of the coating film was 0.5 or less, and the slipperiness was excellent. Further, since the adhesion strength between the coating film and the sheath was 0.3 MPa or more and the boots did not peel off even in the bending test, it was confirmed that the adhesion of the coating film was high.

Regarding the wiping resistance, it was confirmed that the coefficient of static friction did not fluctuate significantly from before the test even after repeated wiping, and the difference between before and after the test was 0.1 or less.
Here, the change in the coefficient of static friction due to the wiping operation of the coating film of Example 1 will be specifically described with reference to the figure. FIG. 9 is a diagram showing a change in the static friction coefficient of the coating film depending on the number of times of wiping. The horizontal axis shows the number of times of wiping [times], and the vertical axis shows the static friction coefficient of the coating film. In FIG. 9, the change in the coefficient of static friction of the coating is composed of a circle (○) plot in Example 1, a square (□) plot in Comparative Example 1, and polyvinyl chloride (PVC) as a reference example. The coatings are shown in triangular (Δ) plots, respectively. As shown in FIG. 9, the coefficient of static friction of the coating film of Example 1 is 0.16 before the wiping test, 0.17 after wiping 20,000 times, and the difference is 0.01. confirmed. The coefficient of static friction of the coating film of Example 2 was 0.14 before the wiping test and 0.15 after wiping 20,000 times, and the difference was 0.01. That is, it was confirmed that the coefficient of static friction did not fluctuate significantly even after wiping 20,000 times, the slipperiness could be maintained high, and the wiping resistance was excellent. Moreover, it was also confirmed that the coefficient of static friction can be maintained lower than that of the PVC coating.

On the other hand, in Comparative Example 1, it was confirmed that although the slipperiness was excellent, not only the adhesion strength between the sheath and the coating film was low, but also the wiping resistance of the coating film was low. Specifically, the adhesion strength was 0.22 MPa, and the boots were peeled off by the bending test. Further, as shown in the plot of □ in FIG. 9, the coefficient of static friction of the coating film of Comparative Example 1 was 0.16 before the wiping test and 0.45 after wiping 20,000 times, and the difference was 0. It was .29. In Comparative Example 1, the coefficient of static friction of the coating film gradually increased by repeating wiping, and the slipperiness could not be maintained. That is, it was confirmed that the coating film of Comparative Example 1 was inferior in wiping resistance.

This difference in characteristics is due to the distribution of fine particles on the surface of the coating and the accompanying uneven shape. These points will be described below.

When the surface unevenness and cross section of the coating film before the wiping test were confirmed for each of the examples and the comparative examples, it was confirmed that the surface of the coating film was in a state as shown in FIGS. 10 and 11. FIG. 10A is an SEM image of the coating surface of Example 1. FIG. 10B is an SEM image of a cross section of the coating film of Example 1. FIG. 11A is an SEM image of the coating surface of Comparative Example 1. FIG. 11B is an SEM image of a cross section of the coating film of Comparative Example 1. Comparing these figures, in the coating film of Example 1, fine particles are densely distributed, whereas in Comparative Example 1, not only fine particles but also depressions (parts displayed in black in the figure) are present. It was confirmed that Further, in the coating film of Comparative Example 1, bubbles (voids) were present over a wide range on the surface in contact with the sheath of the coating film, whereas in the coating film of Example 1, the number of bubbles (voids) was reduced as compared with Comparative Example 1. Was confirmed.

When the number of fine particles was counted based on the SEM image, Example 1 had ^{94 to 96 particles per 1600 μm 2} (40 μm square), and Example 2 had 98 to 101 particles, whereas Comparative Example The number of 1 was 42 to 52. That is, in the examples, the number of fine particles distributed was larger than that in the comparative examples. Further, in Examples 1 and 2, there are substantially no voids having a size of 1 μm or more, whereas in Comparative Example 1, at least 40 voids having a size of 1 μm or more exist within a range of 40 μm square. Was. Further, when the number distribution was obtained from the number of fine particles in each region, it was 1.05% in Example 1 and 1.51% in Example 2, and the variation in the number distribution was small. On the other hand, in Comparative Example 1, the number distribution was 10.6%, the distribution of fine particles in the coating film was not uniform, and the variation was large.

Furthermore, when the surface profiles of the respective coating films of Example 1 and Comparative Example 1 were obtained, the results shown in FIGS. 12 and 13 were obtained. FIG. 12 is a diagram showing a surface profile of the coating film of Example 1. FIG. 13 is a diagram showing a surface profile of the coating film of Comparative Example 1. As shown in FIG. 12, in the coating film of Example 1, no depression due to the void was confirmed, and it was confirmed that more protrusions due to fine particles were present than the recesses due to the depression. On the other hand, in Comparative Example 1, as shown in FIG. 13, it was confirmed that many recesses due to depression were present on the surface of the coating film.

The depression formed in the film is caused by bubbles generated by the condensation reaction when the condensation reaction type silicone rubber is cured. According to this depression, when the coating is wiped with a cotton cloth, the cotton cloth is easily caught by the edge of the depression, so that the coating is easily damaged by wiping. As a result, in Comparative Example 1, it is presumed that the coefficient of static friction tends to increase due to the fine particles falling off due to wiping, and the slipperiness cannot be maintained for a long time. Further, it is presumed that the contact area is reduced due to the presence of voids on the contact surface of the coating film with the sheath, and the adhesion strength is lowered.

In this respect, in this embodiment, by using the addition reaction type silicone rubber, the generation of bubbles due to curing is suppressed, and the depression on the surface of the coating film and the voids in the coating film are reduced. Further, preferably, when the paint is applied by the dipping method, the self-arrangement of the fine particles is promoted by adjusting the pulling speed of the cable. In addition, fumed silica is added to the paint to suppress the sedimentation of fine particles. As a result, it is possible to suppress voids and depressions in the coating film, finely distribute the fine particles on the coating film surface, and obtain a coating film having excellent slipperiness, adhesion to the sheath, and wiping resistance.

<Preferable Aspect of the Present Invention>
Hereinafter, preferred embodiments of the present invention will be added.

(Appendix 1)
According to one aspect of the invention
With the sheath
A coating film that covers the periphery of the sheath and is provided in close contact with the sheath is provided.
The film is formed of a rubber composition containing a rubber component and fine particles, and the coefficient of static friction on the surface of the film is 0.5 or less.
A cotton cloth containing alcohol is brought into contact with the surface of the coating film at a pressure of 2 × 10 ^-3 MPa to 4 × 10 ^-3 MPa, and the surface of the coating film is wiped off at a speed of 200 mm / min to 300 mm / min for 20,000. A cable is provided in which the difference (absolute value) of the coefficient of static friction of the coating film before and after the test is 0.1 or less when the test is repeated many times.

(Appendix 2)
In the aspect of Appendix 1,
The adhesion strength between the sheath and the coating film is 0.30 MPa or more.

(Appendix 3)
In the embodiment of Appendix 1 or 2,
The rubber component is at least one of silicone rubber and chloroprene rubber.

(Appendix 4)
In the aspects of Appendix 1-3
The rubber component is silicone rubber,
The fine particles are at least one of silicone resin fine particles, silicone rubber fine particles, and silica fine particles.

(Appendix 5)
In the aspects of Appendix 1 to 4,
The fine particles have a higher hardness than the rubber component.

(Appendix 6)
In the embodiments of Appendix 1 to 5,
The average particle size of the fine particles is 1 μm or more and 10 μm or less.

(Appendix 7)
In the embodiments of Appendix 1 to 6,
The thickness of the coating film is 3 μm or more and 100 μm or less.

(Appendix 8)
In the embodiments of Appendix 1 to 7,
The sheath is formed of silicone rubber.

(Appendix 9)
In the embodiments of Appendix 1 to 6,
The rubber component is an addition reaction type silicone rubber.

(Appendix 10)
In the aspects of Appendix 1-9,
When the number of the fine particles per unit area is measured at any plurality of locations on the surface of the coating, the formula (N _max −N _min ) / (N _{max ) is derived from the maximum value N max} and the minimum value N _{min of the number.} The number distribution calculated by + N _min ) × 100 is 5% or less.

(Appendix 11)
In the aspects of Appendix 1-10,
On the surface of the coating film, the number of voids having a size of 1 μm or more per unit area is 5/40 μm square or less.

(Appendix 12)
In the embodiments of Appendix 1 to 11,
The cable can be connected to a medical device.

(Appendix 13)
According to another aspect of the invention
Hollow tube body and
A coating film that covers at least one of the inner surface and the outer surface of the hollow tube body and is in close contact with the hollow tube body.
With
The film is formed of a rubber composition containing a rubber component and fine particles, and the coefficient of static friction on the surface of the film is 0.5 or less.
A cotton cloth containing alcohol is brought into contact with the surface of the coating film at a pressure of 2 × 10 ^-3 MPa to 4 × 10 ^-3 MPa, and the surface of the coating film is wiped off at a speed of 200 mm / min to 300 mm / min for 20,000. When the test is repeated many times, the difference (absolute value) of the static friction coefficient of the coating film before and after the test is 0.1 or less.
Medical hollow tubes are provided.

10 Cable 11 Cable core 11a Electric wire 12 Shield 13 Sheath 14 Coating 20 Probe cable 21 Adhesive layer 22 Boot 23 Ultrasonic probe terminal 24 Connector 31 Fine particles 32 Convex 33 Concave (depression)
34 Void 50 Sample cable 51 Adhesive material 52 Boot material tube 53 Sheath material tube 54 Adhesion strength evaluation sample 60 Probe cable 61 Boot 70 Medical hollow tube 71 Hollow tube body 72 Outer coating 73 Inner coating

Claims (12)

With the sheath
A coating film that covers the periphery of the sheath and is provided in close contact with the sheath is provided.
The film is formed of a rubber composition containing a rubber component and fine particles, and the coefficient of static friction on the surface of the film is 0.5 or less.
When the number of the fine particles per unit area is measured at any plurality of locations on the surface of the coating, the formula (N _max −N _min ) / (N _{max ) is derived from the maximum value N max} and the minimum value N _{min of the number.} The number distribution calculated by + N _min ) × 100 is 5% or less.
cable. The adhesion strength between the sheath and the coating film is 0.30 MPa or more.
The cable according to claim 1. The rubber component is at least one of silicone rubber and chloroprene rubber.
The cable according to claim 1 or 2. The rubber component is silicone rubber,
The fine particles are at least one of silicone resin fine particles, silicone rubber fine particles, and silica fine particles.
The cable according to any one of claims 1 to 3. The fine particles have a hardness higher than that of the rubber component.
The cable according to any one of claims 1 to 4. The average particle size of the fine particles is 1 μm or more and 10 μm or less.
The cable according to any one of claims 1 to 5. The thickness of the coating film is 3 μm or more and 100 μm or less.
The cable according to any one of claims 1 to 6. The sheath is formed of silicone rubber,
The cable according to any one of claims 1 to 7. The rubber component is an addition reaction type silicone rubber.
The cable according to any one of claims 1 to 8. On the surface of the coating film, the number of voids having a size of 1 μm or more per unit area is 5/40 μm square or less.
The cable according to any one of claims 1 to 9. The cable can be connected to a medical device,
The cable according to any one of claims 1 to 10. Hollow tube body and
A coating film that covers at least one of the inner surface and the outer surface of the hollow tube body and is in close contact with the hollow tube body.
With
The film is formed of a rubber composition containing a rubber component and fine particles, and the coefficient of static friction on the surface of the film is 0.5 or less.
When the number of the fine particles per unit area is measured at any plurality of locations on the surface of the coating, the formula (N _max −N _min ) / (N _{max ) is derived from the maximum value N max} and the minimum value N _{min of the number.} The number distribution calculated by + N _min ) × 100 is 5% or less.
Hollow tube for medical use.

Images