Cable with Boots

Abstract

To provide a cable with a boot in which an outermost layer has good slipperiness and the outermost layer is less likely to peel.SOLUTION: A cable with a boot includes a probe cable 60 and a boot 61 attached to an end part of the probe cable. An outermost layer of the probe cable includes an addition reaction type silicone rubber with fine particles added thereto. A coefficient of static friction of a surface of the outermost layer is 0.5 or less. In a flexural test where a part of the boot of the cable with the boot is held and bent left and right, the boot causes neither peeling nor breakage under 150,000 times.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a cable with a boot.

Background Art

[0002] JP-A-2008-287 (Patent Document 1) and JP-A-2018-23758 (Cited Document 2) describe technologies related to medical coating compositions capable of imparting stable slidability without applying a lubricant to the surface.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] A sheath made of an insulating member is formed on the surface of the cable. It is desired that this sheath has no stickiness and has good slidability. On the other hand, a protective member such as a boot is attached to the sheath at the end of the cable. Here, in the cable to which the protective member is attached, for example, when the end of the cable is bent, the outermost layer formed on the surface of the sheath may peel off and the protective member may come off the cable. That is, it is required that the cable has no stickiness on the surface of the cable, has good slidability, and the outermost layer formed on the surface of the sheath is difficult to peel off.

[0005] Therefore, an object of the present invention is to provide a cable with a boot having good slidability of the outermost layer and being difficult to peel off the outermost layer.

Means for Solving the Problems

[0006] According to one aspect of the present invention, there is provided a cable with a boot, comprising a cable and a boot attached to an end of the cable, wherein an outermost layer of the cable contains an addition reaction type silicone rubber to which fine particles are added, and a coefficient of static friction on its surface is 0.5 or less, and peeling or breakage of the boot does not occur less than 150,000 times when a bending test is performed to hold a portion of the boot of the cable with the boot and bend it left and right.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a cable with a boot in which the outermost layer has good slipperiness and is difficult to peel off.

Brief Description of the Drawings

[0008]

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BEST MODE FOR CARRYING OUT THE INVENTION

[0009] <Findings by the present inventors> First, the findings obtained by the present inventors will be described.

[0010] For example, in an ultrasonic imaging device which is a medical device, an ultrasonic probe is connected to a cable, and an examination is performed by moving this ultrasonic probe on a human body. At this time, if the cable connected to the ultrasonic probe becomes sticky, the cables may come into contact with each other, or the cable may touch the examiner's clothing or the like, and the cable may get caught. As a result, it becomes difficult to smoothly move the ultrasonic probe, and the handleability of the medical device may be impaired.

[0011] Conventionally, from the viewpoint of ensuring the slidability of the cable, polyvinyl chloride (PVC) has been used as the forming material of the sheath. However, in the case of PVC, the sheath tends to deteriorate, such as discoloration of the sheath as the usage period of the cable becomes longer.

[0012] Therefore, as a sheath material, silicone rubber which is excellent in heat resistance and chemical resistance has been studied as an alternative to PVC. However, the sheath formed from silicone rubber is likely to be sticky (so-called tacky), and thus tends to have low slidability (sliding property).

[0013] Therefore, in order to improve the slidability of the cable, it has been proposed to provide a film having a small coefficient of static friction on the surface of the sheath formed from silicone rubber. As the film having a small coefficient of static friction, a film formed of a rubber composition containing fine particles and having minute irregularities due to the fine particles on the surface has been studied.

[0014] However, according to the study by the present inventors, it has been found that although slidability can be obtained with the cable provided with the above-described film, the following problems occur.

[0015] One is that sufficient adhesion strength cannot be ensured between the coating and the sheath. When the cable is used as, for example, a probe cable, a boot may be attached to its terminal 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, perhaps due to the low adhesion strength between the sheath and the coating, when bending pressure is applied to the boot attached to the cable, peeling may occur at the interface between the sheath and the coating, and the boot may come off the cable.

[0016] The other is that the wiping resistance of the coating is low. Cables for medical use are wiped with disinfectant alcohol or the like to keep the surface clean and are repeatedly used. However, according to the studies by the present inventors, it was found that as the number of wipings increases, perhaps because the uneven state of the coating surface changes, the static friction coefficient of the coating increases, and it becomes difficult to obtain the desired slipperiness. That is, in the coating, the slipperiness may not be maintained at a high level over long-term use.

[0017] The present inventors studied the above problems and found that the factor that degrades the various properties of the coating is air bubbles present in the coating. Air bubbles are generated when the liquid material forming the coating is cured. When these air bubbles exist on the surface of the coating in contact with the sheath, the adhesion area between the coating and the sheath decreases, and the adhesion strength becomes low. On the other hand, when air bubbles exist on the surface of the coating, depressions (concave portions) may be formed, and the edges of such concave portions may catch during wiping. Therefore, the coating is easily scraped off during wiping, and repeated wiping makes it easy for the slipperiness to decrease. Furthermore, air bubbles inhibit the dense distribution of fine particles on the surface of the coating, and also have a great influence on the uneven state of the coating surface and thus on various properties due to the unevenness.

[0018] From these points, the present inventors considered reducing the air bubbles (voids) present in the coating by suppressing the generation of air bubbles when the coating is cured and formed, and found that in the coating, slipperiness, adhesiveness, and wiping resistance can be realized in a well-balanced manner at a high level.

[0019] The present invention has been made based on the above findings.

[0020] <One Embodiment of the Present Invention> Hereinafter, one embodiment of the present invention will be described with reference to the drawings using a cable for medical equipment that can be connected to a medical device as an example. In all the drawings for explaining the embodiment, the same members are generally denoted by the same reference numerals, and repeated explanations thereof are omitted. In addition, hatching may be added even in a plan view in order to make the drawing easier to understand.

[0021] [Cable] As shown in FIG. 1, the medical equipment cable 10 (hereinafter, also simply referred to as cable 10) of the present embodiment is configured by sequentially laminating a sheath 13 and a coating 14 on the outer periphery of a cable core 11.

[0022] (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, those obtained by covering 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 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.

[0023] (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. For example, silicone rubber, polyethylene, chlorinated polyethylene, chloroprene rubber, polyvinyl chloride (PVC), or the like can be used. Among them, silicone rubber and chloroprene rubber are preferable from the viewpoints of chemical resistance and heat resistance. In addition, general compounding agents such as various crosslinking agents, crosslinking catalysts, antioxidants, plasticizers, lubricants, fillers, flame retardants, stabilizers, and colorants may be added to the insulating material forming the sheath.

[0024] (Coating) The coating 14 is provided to cover the sheath 13. The coating 14 is formed from a rubber composition containing fine particles and a rubber component, and the fine particles are finely dispersed in the rubber component. Concavities and convexities derived from the fine particles are formed on the surface of the coating 14. Due to these concavities and convexities, when the coating 14 comes into contact with another member, the contact area can be reduced, and the static friction coefficient of the coating 14 can be made smaller than the static friction coefficient that the rubber component constituting the coating 14 originally has. According to such a coating 14, the slidability of the cable 10 can be enhanced as compared with the case where the sheath 13 is present on the surface.

[0025] The static friction coefficient of the coating 14 is not particularly limited, but from the viewpoint of imparting a desired slidability to the cable 10, it is preferably 0.5 or less.

[0026] Further, since the fine particles are densely distributed on the surface of the coating 14, the coating 14 has high wiping resistance. Specifically, when a test is conducted in which a long fiber nonwoven fabric (hereinafter also simply referred to as a cotton cloth) having a length of 50 mm in the wiping direction using a cotton linter containing alcohol for disinfection is brought into contact with the surface of the coating 14 so that a shear stress of 2×10 -3 MPa to 4×10 -3 MPa acts, and the surface of the coating 14 is wiped 20,000 times (10,000 cycles) at a speed of 80 times / min to 120 times / min (40 cycles / min to 60 cycles / min) in the wiping direction with a length of 150 mm, the difference (absolute value) in the static friction coefficient of the coating 14 before and after the test can be made 0.1 or less, preferably 0.05 or less. That is, even when the coating 14 is repeatedly wiped, the surface unevenness can be maintained, and the slidability due to the unevenness can be maintained over a long period. Note that the length of the cotton cloth indicates the length of the cotton cloth in the wiping direction. Also, the length in the wiping direction refers to the length of the portion where the cable sheath is completely wiped off when the cotton cloth is moved to wipe the surface of the coating 14 with the cotton cloth. Further, the shear stress indicates the pulling force (resistance at the time of pulling out) that occurs when the cable is pressed with a cotton cloth impregnated with ethanol for disinfection and the cable is pulled out from the cotton cloth in order to wipe the cable.

[0027] In addition, the impregnation amount of the disinfecting alcohol contained in the cotton cloth only needs to be an amount sufficient for the disinfecting alcohol to permeate the entire cotton cloth. For example, generally, the amount of disinfecting alcohol contained in medical gauze is 5 ml to 6 ml per 1 g of the cotton cloth. Since the weight (size) of the cotton cloth increases or decreases depending on the outer diameter of the cable to be wiped, the weight of the cotton cloth to be used is measured in advance, and the impregnation amount is adjusted according to the weight. For example, in the case of a cable with an outer diameter of 6.7 mmΦ, a cotton cloth weighing about 0.25 to 0.30 g (manufactured by Asahi Kasei Corporation, "Bencot Regular Type (M-3II)") is required, so it is good to impregnate a liquid amount of 2.0 ml that sufficiently satisfies the above.

[0028] Further, in the present embodiment, as will be described in detail later, since the generation of bubbles during the curing of the rubber composition is suppressed, the bubbles (voids) present in the coating 14 can be reduced. Therefore, on the surface of the coating 14 on the sheath 13 side, a decrease in the area due to bubbles (voids) can be suppressed. Thereby, the contact area between the coating 14 and the sheath 13 can be maintained large, and the adhesion strength between the coating 14 and the sheath 13 can be made higher than when bubbles are present. Specifically, the adhesion strength between the coating 14 and the sheath 13 can be 0.3 MPa or more. The upper limit of the adhesion strength between the sheath 13 and the coating 14 is not particularly limited, but substantially about 0.7 MPa is the upper limit.

[0029] Also, since bubbles can be reduced on the surface side of the coating 14, dents due to bubbles can be reduced. Since fine particles cannot exist at the dented locations, when dents are formed, the area where the fine particles can be distributed becomes smaller. Therefore, the number of fine particles distributed on the surface of the coating 14 decreases. That is, the distribution of the fine particles becomes sparse. Moreover, since a plurality of fine particles are likely to aggregate to form coarse aggregated particles, it becomes difficult to obtain the desired unevenness. On the other hand, by reducing the dents, the number of fine particles occupying the surface of the coating 14 can be increased, the aggregation of the fine particles can be suppressed, and the fine particles can be distributed more densely.

[0030] In addition, since the fine particles are densely distributed on the surface of the coating film 14, the variation in the number of fine particles among regions is small. Specifically, when measuring the number of fine particles per unit area at any plurality of locations on the surface of the coating film 14, it is preferable that the number distribution calculated by the formula ((Nmax - Nmin) / (Nmax + Nmin))×100 from the maximum value Nmax and the minimum value Nmin of the number is 5% or less. The smaller this number distribution, the smaller the deviation in the number of fine particles, indicating that the distribution of the fine particles has less variation.

[0031] Also, on the surface of the coating film 14, it is preferable that there are few voids due to bubbles, and it is more preferable that there are substantially no voids. Specifically, when observing with an electron microscope SEM under the condition of 1000 times magnification, the number of voids with a size of 1 μm or more existing per unit area is preferably 5 pieces / 40 μm square or less, and it is more preferable that there are substantially no voids with a size of 10 μm or more.

[0032] On the surface of the coating film 14, it is preferable that there are few recessed portions sunken due to voids and many convex portions raised by the fine particles. That is, the surface of the coating film 14 preferably has surface unevenness mainly formed by the convex portions.

[0033] The thickness of the coating film 14 is not particularly limited, but it is preferably 3 μm or more and 100 μm or less. By setting it to 3 μm or more, predetermined wiping resistance can be imparted to the coating film 14. Also, by setting it to 100 μm or less, the flexibility and bendability of the cable 10 can be maintained at a high level.

[0034] (Rubber composition for film formation) Next, the rubber composition for forming the coating film 14 will be described.

[0035] The rubber composition is a cured product obtained by curing a liquid rubber composition (hereinafter also referred to as a paint) containing a liquid rubber, fine particles, a curing catalyst, and, if necessary, other additives, and is composed of a cured rubber component and fine particles.

[0036] The rubber component is the matrix component that constitutes the coating 14. As the rubber component, silicone rubber can be used. There are two types of silicone rubber, a condensation reaction type and an addition reaction type, depending on the curing method. Among them, the addition reaction type is preferred. The addition reaction type silicone rubber is less likely to generate bubbles during curing compared to the condensation reaction type silicone rubber, and can make the distribution of fine particles in the coating 14 denser.

[0037] 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 (CH2=CH-) and an organohydrogenpolysiloxane having a hydrosilyl group (Si-H). The organopolysiloxane serves as the base polymer of the silicone rubber. The organohydrogenpolysiloxane serves as a crosslinking agent for the base polymer. For example, by mixing a platinum catalyst, the organohydrogenpolysiloxane crosslinks and cures the base polymer by hydrosilylation reaction between the hydrosilyl group and the vinyl group in the base polymer. The organopolysiloxane and the organohydrogenpolysiloxane are not particularly limited, and conventionally known ones can be used.

[0038] Also, chloroprene rubber may be used as the rubber component, and the coating 14 may be configured to contain chloroprene rubber.

[0039] The fine particles form convex portions that protrude from the surface of the coating 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 properties required for the coating 14.

[0040] Specifically, from the perspective of maintaining the uneven shape of the coating film 14 and ensuring slipperiness when an object comes into contact with the coating film 14, it is preferable that the fine particles have a higher hardness than the coating film 14. Specifically, it is preferable that the fine particles have a hardness of 1.1 times or more the hardness of the cured product constituting the coating film 14 in terms of Shore (durometer A) hardness. The higher the hardness of the fine particles, the less likely the fine particles are to deform under the pressing pressure when an object comes into contact with the surface of the coating film 14, and it becomes easier to maintain the uneven shape of the coating film 14. Since the hardness increases in the order of silicone rubber, silicone resin, and silica, silica fine particles are preferable from the perspective of hardness.

[0041] On the other hand, from the perspective of uniformly distributing the fine particles on the surface of the coating film 14 to form a desired surface unevenness, it is preferable that the fine particles have a small mass. If the mass of the fine particles is large, the fine particles will settle before the paint is cured to form the coating film 14, making it difficult to form appropriate unevenness on the coating film 14. In this regard, by reducing the mass of the fine particles, sedimentation can be suppressed, and it becomes easier to form appropriate unevenness 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 perspective of mass.

[0042] That is, in the coating film 14, from the perspective of maintaining the uneven shape to ensure slipperiness and making it easier to form a desired uneven shape while achieving both, silicone resin fine particles are most preferable.

[0043] 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 it to 10% by mass or more, unevenness can be formed on the surface of the coating film 14, the coefficient of static friction of the coating film 14 can be reduced, and the desired slipperiness can be imparted. On the other hand, if the amount of the fine particles becomes excessively large, the strength of the coating film 14 may decrease. However, by setting the content to 60% by mass or less, the strength can be maintained while obtaining slipperiness. The content of the fine particles is calculated assuming that the paint cures with almost no mass loss, and indicates the ratio to the cured coating film 14 (the total of the rubber component and the fine particles). That is, it is preferable that the fine particles are contained in the rubber composition in an amount of 10% to 60% by mass based on the total of the rubber component and the fine particles.

[0044] 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 unevenness on the coating film 14, the average particle diameter of the fine particles is preferably 1 μm or more and 10 μm or less. Here, the average particle diameter indicates the value measured by the laser diffraction scattering method. By setting the average particle diameter to 1 μm or more, it becomes easier to form appropriate unevenness 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 enhanced. Also, by setting the average particle diameter to 10 μm or less, the mass of the fine particles can be adjusted to an appropriate size, so that sedimentation of the fine particles and coating unevenness when applying the liquid rubber composition can be suppressed.

[0045] The curing catalyst is not particularly limited as long as it can promote the addition reaction. For example, platinum or a platinum-based compound may be used.

[0046] Other additives may be blended as needed. For example, an organic solvent can be used for the purpose of adjusting the viscosity of the paint. As the organic solvent, for example, aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as n-hexane, n-heptane, n-octane, isooctane, nonane, decane, undecane, dodecane, etc. can be used alone or in admixture of two or more. Also, for example, alcohols such as ethanol and isopropyl alcohol, and acetone can be used.

[0047] The viscosity of the paint is not particularly limited, but from the viewpoint of densely distributing the fine particles, it is preferably 1 mPa·s or more and 100 mPa·s or less. With such a viscosity range, the thickness of the film can also be appropriately changed. The viscosity was measured using a tuning fork vibration type viscometer (manufactured by A&D Company, Ltd., SV-H) under the condition of a temperature of 25 ± 2°C.

[0048] Also, for example, from the viewpoint of forming desired irregularities on the surface of the film, it is preferable to add fumed silica having a smaller particle diameter than the above fine particles to the rubber composition. Fumed silica is obtained by firing a raw material silicon chloride at a high temperature, and for example, it indicates silica ultrafine particles having an average particle diameter of primary particles of 10 nm or more and 30 nm or less. Fumed silica includes hydrophilic ones having silanol groups (Si-OH) on their surfaces and hydrophobic ones obtained by chemically reacting the silanol groups on the surface, and either can be used. Fumed silica has excellent dispersibility in the paint and contributes to improving the dispersibility of the above fine particles in the paint. As a result, sedimentation of the fine particles in the paint can be suppressed, and desired irregularities can be formed on the film surface.

[0049] The content of fumed silica is not particularly limited, but it is preferably 0.1% by mass or more and 0.5% by mass or less. Here, the content is calculated assuming that the paint cures with almost no mass loss, similar to the above fine particles, and indicates the ratio to 100 parts by mass of the cured rubber component.

[0050] [Method for manufacturing a cable] Next, the manufacturing method of the cable 10 described above will be explained.

[0051] First, a plurality of electric wires 11a (for example, 100 or more) such as coaxial cables are bundled together. For example, a braided shield is formed as the shield 12 so as to cover the bundled plurality of electric wires. Thereby, the cable core 11 is obtained.

[0052] Subsequently, a sheath material containing, for example, silicone rubber is extruded so as to cover the surface of the cable core 11, and the sheath 13 is formed.

[0053] From the viewpoint of enhancing the adhesion between the coating 14 and the sheath 13, it is preferable to add an infrared absorber to the sheath material. According to the infrared absorber, when the coating 14 is heated with infrared rays, the infrared absorption of the sheath 13 is enhanced, and it becomes easier to heat from the sheath 13 side. Therefore, in the coating film of the rubber composition, uneven curing in the thickness direction can be reduced, and curing in a deep portion (the portion on the sheath 13 side) from the surface can be further promoted. As a result, the adhesion strength between the obtained coating 14 and the sheath 13 can be made higher. Moreover, the time for heating and curing the coating film of the rubber composition can be shortened.

[0054] The infrared absorber is not particularly limited, and for example, CoO, Fe2O3, MnO2, Cr2O3, CuO, NiO, titanium oxide (TiO2), carbon, etc. can be used.

[0055] The content of the infrared absorber is not particularly limited as long as the properties of the sheath 13 are not impaired. From the viewpoint of improving the adhesion strength with the coating 14, the content is preferably 0.1% by mass or more. On the other hand, if the content becomes excessively large, the sheath 13 may become brittle and the tear strength may decrease. Therefore, from the viewpoint of maintaining a high tear strength, it is preferably 10% by mass or less. Here, the content indicates the ratio with respect to 100 parts by mass of the sheath component.

[0056] Subsequently, a coating material is applied onto the surface of the sheath 13 to form a coating film. The method of applying the coating material is not particularly limited, and may be appropriately selected, for example, from a dipping method, a spray coating method, a roll coating method, etc. Among these, the dipping method is preferred.

[0057] The dipping method is, for example, a method of forming a coating film on the surface of the sheath 13 by immersing the wire material forming the sheath 13 in the coating material and then pulling it out. According to the dipping method, the coating film thickness can be made uniform, so that the film thickness of the coating 14 can be made uniform in the longitudinal direction. Moreover, by adjusting the pulling speed of the cable 10, the distribution of the fine particles in the coating 14 can be controlled more densely. This will be described below.

[0058] In the dipping method, when the cable 10 is pulled out from the liquid surface of the coating material, the coating material adheres to the surface of the cable 10. When this coating material adheres to the surface of the cable 10, the fine particles may move and self-align in the coating film. Due to this self-alignment, the fine particles can be densely distributed on the surface of the coating film. And the slower the pulling speed of the cable, the more time can be ensured for the self-alignment of the fine particles, and the more stable the dense distribution state of the fine particles can be reproduced.

[0059] Specifically, from the viewpoint of densely distributing the fine particles, it is preferable that the pulling speed of the cable 10 be 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 it to 1 m / min or more and 5 m / min or less, while maintaining productivity, the distribution of the fine particles on the surface of the coating can be made denser.

[0060] Subsequently, the coating film is heated to be dried and cured, thereby forming a coating 14 having a predetermined surface unevenness. The heating temperature is not particularly limited, but may be, for example, 120°C to 200°C.

[0061] In heating the coating film, when an infrared absorber is added to the sheath 13, it is preferable to use an infrared heater. By heating with an infrared heater, the heating of the sheath 13 is promoted, and uneven curing in the thickness direction of the resulting coating film 14 can be suppressed, so that the adhesion strength between the coating film 14 and the sheath 13 can be made higher. Moreover, the time until the coating film 14 is cured can be shortened, and the manufacturing efficiency of the cable 10 can be improved.

[0062] Thus, the cable 10 of the present embodiment is obtained.

[0063] [Probe Cable] As shown in FIG. 2A, for example, the probe cable 20 is configured such that an ultrasonic probe terminal 23 (hereinafter also simply referred to as the terminal 23) and a protective member 22 for protecting the terminal 23 are attached to one end of the cable 10, and a connector 24 is attached to the other end. 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 as shown in FIG. 2B, it is attached to cover the coating film 14 via an adhesive layer 21 on the coating film 14. The adhesive layer 21 is formed of, for example, a silicone-based adhesive or an epoxy-based adhesive.

[0064] <Effects according to the present embodiment> According to the present embodiment, one or more of the following effects are achieved.

[0065] (a) In the cable 10 of this embodiment, a coating 14 formed from 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 compared to the condensation reaction type silicone rubber. Thereby, the generation of voids derived from bubbles can be suppressed on the surface of the coating 14 that contacts the sheath 13. As a result, the area where the coating 14 contacts the sheath 13 can be maintained without being reduced, and high adhesion between the coating 14 and the sheath 13 can be ensured. Further, before forming the coating 14, without forming a special layer (for example, an adhesion reinforcing layer made of a primer or a silane coupling agent, a flame treatment by exposing to a short-time flame, or a surface modification layer by methods such as plasma treatment in which gas is ionized and radicalized and collided with the surface, or corona treatment in which components in the air are ionized by atmospheric discharge and exposed to this) on the surface of the sheath 13, the adhesion strength between the sheath 13 and the coating 14 can be made 0.30 MPa or more. However, it does not exclude providing the above special layer in order to further increase the strength. Further, according to the addition reaction type silicone rubber, since the voids in the film also decrease, an effect of improving the strength of the film itself can be expected.

[0066] (b) Further, in the coating 14, the generation of voids on its surface can also be suppressed. Therefore, the number of fine particles occupying the surface of the coating 14 can be increased, the aggregation of the fine particles can be suppressed, and the fine particles can be distributed more densely on the surface of the coating 14. Thereby, since desired irregularities can be formed on the surface of the coating 14, the static friction coefficient of the coating 14 can be made smaller than that of the sheath 13, and high slidability can be realized.

[0067] (c) Moreover, since there are few depressions due to voids on the surface of the coating film 14, when repeatedly wiping the surface of the coating film 14 with a cotton cloth or the like, the cotton cloth is caught on the edge of the depression, and damage to the coating film 14 can be suppressed. For this reason, even when repeated wiping is performed, the static friction coefficient can be kept small, and high wiping resistance can be realized. Specifically, a cotton cloth (50 mm in length in the wiping direction) containing alcohol for disinfection is brought into contact with the surface of the coating film 14 so that a shear stress of 2×10 -3 MPa to 4×10 -3 MPa acts, and the surface of the coating film 14 is wiped at a speed of 80 times / min to 120 times / min (40 cycles / min to 60 cycles / min) 20,000 times (10,000 cycles). When this test is repeated, the difference (absolute value) in 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.

[0068] (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, self-arrangement of the fine particles can be promoted in the paint, and the fine particles can be distributed more densely on the surface of the coating film.

[0069] (e) Also, 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, the time for self-arrangement of the fine particles can be ensured, and the productivity of the coating film 14 can be maintained high. Thereby, the fine particles can be distributed more densely on the surface of the coating film 14.

[0070] (f) The static friction coefficient on the surface of the coating 14 is preferably 0.5 or less, more preferably 0.3 or less, and still more preferably 0.22 or less. In the present embodiment, by forming irregularities on the surface of the coating 14, the static friction coefficient on the surface of the coating 14 can be made smaller than the static friction coefficient inherent in the rubber component constituting the coating 14 and can be made 0.5 or less. By setting such a friction coefficient, high slidability can be realized so that the cables 10 do not get caught when they come into contact with each other.

[0071] (g) Since fine particles are densely distributed on the surface of the coating 14, the number of fine particles distributed at each of a plurality of arbitrarily selected locations on the surface does not vary greatly, and there is little variation in the number. Specifically, when the number of fine particles per unit area is measured at a plurality of arbitrary locations on the surface of the coating 14, it is preferable that the number distribution ((Nmax - Nmin) / (Nmax + Nmin)) × 100 calculated from the maximum value Nmax and the minimum value Nmin of the number is 5% or less. By distributing the fine particles densely and uniformly on the surface of the coating 14 in this way, the slidability and wiping resistance of the coating 14 can be made higher.

[0072] (h) On the surface of the coating 14, the number of voids having a size of 1 μm or more per unit area is preferably 5 or less per 40 μm square, and it is more preferable that there are substantially no voids having a size measurable by an electron microscope. By reducing the number of voids, the fine particles can be distributed more densely, so that the slidability and wiping resistance of the coating 14 can be made higher.

[0073] (i) In the coating 14, since recesses due to sinking can be suppressed, the surface irregularities can be mainly composed of convex portions formed by fine particles. Thereby, the wiping resistance can be increased. Hereinafter, this point will be specifically described.

[0074] For example, as shown in FIG. 3B, when the film 14' is formed of a condensation reaction type silicone rubber, voids 34 derived from air bubbles are formed in the film 14'. When these voids 34 exist on the surface, they become depressions 33 (concave portions 33). In such a film 14', when wiping with a cotton cloth, the cotton cloth is likely to get caught on the edge of the opening of the depression 33. When the cotton cloth gets caught, the film 14' is scraped off, and by repeating this, fine particles 31 are detached from the film 14' and the convex portions 32 of the film 14' gradually become smaller. As a result, the static friction coefficient of the film 14' cannot be maintained small, and the slidability is gradually impaired.

[0075] On the other hand, as shown in FIG. 3A, by suppressing the formation of depressions due to voids on the surface of the film 14, the convex portions 32 due to the fine particles 31 can be increased. According to such a film 14, although there are surface irregularities, deep depressions are less likely to be formed, so it is possible to suppress getting caught by the cotton cloth, and even when repeated wiping is performed, the static friction coefficient of the film 14 can be maintained small. That is, the wiping resistance can be made higher.

[0076] (j) The fine particles 31 preferably have a higher hardness than the rubber component forming the film 14. According to such fine particles 31, it is easy to maintain the uneven shape of the film 14, and the desired slidability can be realized.

[0077] (k) As the 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 silica fine particles, since the hardness is high, it is easy to ensure slidability. Also, according to silicone rubber fine particles, since the mass is relatively small, it is difficult to settle when the paint is applied, and appropriate surface irregularities can be formed. According to silicone resin fine particles, since both the hardness and the mass are between those of silicone rubber fine particles and silica fine particles, it is easy to form the desired uneven shape and easy to maintain the uneven shape to ensure slidability.

[0078] (l) Further, the rubber composition preferably further contains fumed silica. According to the fumed silica, sedimentation of fine particles in the paint can be suppressed, so that a film having excellent slipperiness, adhesion, and wiping resistance can be formed in a well-balanced manner at a high level.

[0079] (m) Further, the sheath 13 preferably further contains an infrared absorber. According to the infrared absorber, when heating the rubber composition with an infrared heater, the infrared absorption of the sheath 13 can be enhanced, and the rubber composition can be easily heated also from the sheath 13 side. Thereby, uneven curing in the thickness direction of the film 14 can be suppressed, and the adhesion strength between the film 14 and the sheath 13 can be further improved.

[0080] (n) In the probe cable 20, a protective member 22 is attached via an adhesive layer 21 on the film 14 at one end of the cable 10. In the present embodiment, since the adhesion strength between the film 14 and the sheath 13 can be increased, even when, for example, bending pressure is applied to the protective member 22, it is possible to prevent the film 14 from peeling off from the sheath 13 and the protective member 22 from coming off. Further, since the film 14 having irregularities on the surface is excellent in slipperiness, even when the probe cables 20 come into contact with each other when, for example, moving an ultrasonic probe connected to the probe cable 20, it is possible to suppress snagging. Further, since the film 14 is excellent in wiping resistance, even when repeatedly wiped with a cotton cloth, damage and wear of the film 14 can be suppressed, and its slipperiness can be maintained for a long period of time. Furthermore, since the film 14 formed of silicone rubber is also excellent in chemical resistance and heat resistance, even when washed with chemicals such as alcohol for disinfection or heated, alteration of the film can be suppressed.

[0081] <Other Embodiments> In the above-described embodiment, the case where the probe cable 20 is provided with the film 14 has been described, but the present invention is not limited thereto. For example, the above-described film can also be provided on medical cables other than the probe cable 20 (such as an endoscope cable or a catheter connection cable) or a cab tire cable.

[0082] Also, although the case where the coating 14 is provided on the surface of the sheath 13 of the cable 10 has been described, the present invention is not limited thereto, and it is particularly effective and applicable to a molded body that needs to wipe the surface with a disinfectant alcohol or the like from the hygienic aspect and keep it clean. For example, there are handrails (handrails), suspension straps, touch panels, films for protecting touch panels, medical hollow tubes such as catheters, etc. Furthermore, in addition to medical hollow tubes such as catheters, the coating 14 can also be applied to hollow tubes such as air tubes and water supply tubes used for sliding parts of robots and movable parts inside Cable Bear (registered trademark). Hereinafter, the case of applying to a medical hollow tube as a molded body will be specifically described with reference to the drawings.

[0083] FIG. 4A is a cross-sectional view of a medical hollow tube 70 having an outer coating 72 on the outer surface 71a of a hollow tube body 71. FIG. 4B is a cross-sectional view of a medical hollow tube 70 having an inner coating 73 on the inner surface 71b of the hollow tube body 71. FIG. 4C is a cross-sectional view of a medical hollow tube 70 having an outer coating 72 and an inner coating 73 on the outer surface 71a and the inner surface 71b of the hollow tube body 71, respectively.

[0084] The medical hollow tube 70 includes a hollow tube body 71, and an outer coating 72 and / or an inner coating 73 that cover the periphery (outer surface 71a or inner surface 71b, or both surfaces) of the hollow tube body 71 and are in close contact with the hollow tube body 71. The hollow tube body 71 is preferably formed of, for example, silicone rubber. The outer coating 72 and / or the inner coating 73 may be constituted by the above-described coating 14. The hollow tube body 71 may be added with an infrared absorber in the same manner as the sheath 13 of the cable 10.

[0085] According to such a medical hollow tube 70, since the inner and outer surfaces are excellent in slidability, it is possible to suppress snagging when contacting other members, and it is possible to smoothly insert and remove the instrument when inserting the instrument into the tube.

[0086] Further, in the outer coating 72 and / or the inner coating 73, generation of voids derived from air bubbles is suppressed on the surface in contact with the hollow tube body 71. Therefore, it is possible to maintain the outer coating 72 and / or the inner coating 73 without reducing the contact area with the hollow tube body 71, and high adhesion can be ensured between the outer coating 72 and / or the inner coating 73 and the hollow tube body 71. Specifically, the adhesion strength can be set to 0.30 MPa or more. Note that the structure of the medical hollow tube 70 can be applied to hollow tubes other than medical applications, for example, the above-described air tubes and water supply tubes.

Example

[0087] Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0088] [Example 1] (Production of cable) First, 200 coaxial cables with a diameter of about 0.25 mm were twisted together and covered with a braided wire to produce 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 with a thickness of 0.8 mm (cable outer diameter: about 8 mm). As the sheath material, silicone rubber ("KE-541-U" manufactured by Shin-Etsu Chemical Co., Ltd.) was used.

[0089] Subsequently, a material for forming a film was prepared. In Example 1, as the rubber component, an addition reaction type silicone rubber coating agent (trade name: SILMARK-TM, manufactured by Shin-Etsu Chemical Co., Ltd.) was used, and as the fine particles, silicone resin fine particles with an average particle size of 5 μm (trade name: X-52-1621, manufactured by Shin-Etsu Chemical Co., Ltd.) were prepared respectively. 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 viscosity adjustment, 8 parts by mass of a crosslinking agent (trade name: CAT-TM, manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.3 parts by mass of a curing catalyst (trade name: CAT-PL-2, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to prepare a coating solution in which the proportion of silicone resin fine particles to the 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 above film was calculated assuming that the coating agent cured with almost no mass loss (substantially equivalent to the blending mass ratio). The composition of the coating solution is shown in Table 1 below.

[0090] Subsequently, the surface of the sheath provided on the cable core was cleaned. Then, the cable core with the sheath provided thereon was immersed in the above coating solution by the dip coating method to form a coating film made of silicone rubber on the sheath surface. In this example, the pulling speed of the cable core was set at 2 m / min. Then, a drying and curing treatment was performed on the coating film at a temperature of 150 °C for 10 minutes by heating with a heater (infrared rays) to form a film having irregularities on the surface. The film thickness of the obtained film was 15 μm.

[0091] Thus, the cable of Example 1 was manufactured.

[0092]

Table 1

[0093] [Example 2] In Example 2, the coating solution was prepared and the cable was produced in the same manner as in Example 1, except that the content of the silicone rubber resin particles was changed from 120 parts by mass to 150 parts by mass so that the proportion of the silicone resin fine particles in the coating became 60.0% by mass.

[0094] [Example 3] In Example 3, the coating solution was prepared and the cable was produced in the same manner as in Example 1, except that fumed silica was not added.

[0095] In Example 4, the coating solution was prepared and the cable was produced in the same manner as in Example 1, except that titanium oxide (infrared absorber) was added to the sheath so that the amount of the infrared absorber became 1 part by mass with respect to 100 parts by mass of the sheath.

[0096] [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 (trade name: X-52-1621, manufactured by Shin-Etsu Chemical Co., Ltd.) having an average particle size of 5 μm. 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 vinyloxime silane and a solvent (toluene, n-heptane) was used.

[0097] [Comparative Example 2] In Comparative Example 2, the coating solution was prepared and the cable was produced in the same manner as in Example 1, except that the pulling-up speed of the cable was increased to 12 m / min.

[0098] (Evaluation) For each of the cables produced above, the static friction coefficient 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.

[0099] (Static friction coefficient) First, a cut was made in the sheath portion of the cable prepared above in the longitudinal direction, the contents other than the sheath were removed, and the sheath was opened. A test sheet 1 with a flat sheet having a length of about 10 cm and a width of about 2.5 cm attached to a flat plate and a sheet 2 with a flat sheet having a size of 1.5 cm × 1.5 cm attached to a flat plate were prepared. The surface of the test sheet 1 with the coating or the surface after wiping was brought into contact from above so that the surface of the sheet 2 with the coating faced it. While applying a load W of 2 N from above the flat plate of the sheet 2, the flat plate with the sheet 2 was pulled horizontally with a push-pull gauge, and the pulling force (frictional force) F was measured. The static friction coefficient μ was calculated from F = μW. In this example, the static friction coefficient was calculated for each of the rubber composition forming the coating and the rubber composition forming the sheath. Here, the sheets 1 and 2 were prepared using the cable after the wiping test, and the static friction coefficient after wiping was measured.

[0100] (Adhesion strength) The adhesion strength between the sheath and the coating was measured based on FIGS. 5 and 6. FIG. 5 is a diagram for explaining a method of preparing an evaluation sample for evaluating the adhesion strength between the sheath and the coating. FIG. 6 is a diagram schematically showing a measuring method for measuring the tensile shear strength using the evaluation sample.

[0101] Specifically, first, a sample cable with a length of 100 mm was taken from the cable produced above. Also, 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 its longitudinal direction. As shown in FIG. 5, at one end of the sample cable 50, an adhesive 51 was applied to its outer peripheral surface. Subsequently, one end portion of this sample cable 50 was wrapped with the boot material tube 52 so as to join the cut 52a, and the sample cable 50 and the boot material tube 52 were adhered. Next, the contents other than the sheath (such as the cable core) were pulled out and removed from the other end of the sample cable 50, and a product in which the sheath material tube 53 and the boot material tube 52 were adhesively integrated was produced. Subsequently, a cut was made in this adhesively integrated product in the longitudinal direction. 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. Thereby, a sample 54 for evaluating the adhesion strength shown in FIG. 6 was produced. The sheath material tube 53 and the boot material tube 52 were made of the same silicone rubber (static friction coefficient: 1.0 or more). As the adhesive 51, a commercially available silicone-based adhesive KE-45 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used. The adhesion area at this time was, for example, a length of 10 mm × an outer circumference of 25 mm, and the thickness of the adhesive 51 was set to about 50 μm to 200 μm. The evaluation sample 54 thus created was left in the air at 25°C for 168 hours.

[0102] The adhesion strength between the sheath material tube 53 and the coating was evaluated by measuring the tensile shear strength using the evaluation sample 54. Specifically, as shown in FIG. 6, while gripping the respective end portions of the sheath material tube 53 and the boot material tube 52, the sheath material tube 53 and the boot material tube 52 were pulled at a speed of 500 mm / min to measure the tensile shear strength and measure the adhesion strength between the sheath material tube 53 and the coating. The gripping positions of the respective tubes were adjusted so that the distance between the gripping portions became 70 mm when each tube was gripped. In this example, if the adhesion strength was 0.30 MPa or more, it was evaluated that there was sufficient adhesion.

[0103] (Flexure resistance) The flexure characteristics were evaluated from the adhesion of the boot as a protective member to one end of the cable 10 with a silicone-based adhesive KE-45 to produce a probe cable and repeatedly flexing the probe cable. The materials of the sheath and the boot were the same silicone rubber ("KE-541-U" manufactured by Shin-Etsu Chemical Co., Ltd.). The adhesion area between the probe cable and the boot was 250 mm 2 (The adhesion area was 10 mm in length × 25 mm in outer circumference).

[0104] Specifically, the evaluation was performed as shown in FIG. 7. FIG. 7 is a diagram schematically showing the flexure resistance test of the probe cable (length 1 m). First, a load of 500 g was applied to the probe cable 60, and the portion of the boot 61 attached to the end of the probe cable was held so that the probe cable was in a vertical state, and an operation of flexing this held portion 90 degrees to the left and right at a speed of 30 times / minute was performed. Here, first, the held portion was set to a vertical state, then bent 90 degrees to the left, returned to the vertical state, then bent 90 degrees to the right, and returned to the vertical state. This series of bending operations was counted as one time. The total number of bending times was 150,000 times or more for the left and right bends. In this example, when the boot 61 did not peel or break when such a flexure resistance test was performed, it was judged that the flexure resistance was good (○), while when the boot 61 peeled or broke in less than 150,000 times, it was judged that the flexure resistance was poor (×).

[0105] (Wiping resistance) The wiping resistance of the coating was evaluated by repeatedly wiping the surface of the coating with a cotton cloth impregnated with disinfectant alcohol in the tests shown in FIGS. 8A and 8B. FIG. 8A is a diagram for explaining the wiping test method. FIG. 8B is a diagram for explaining the length in the wiping direction of the cotton cloth and the length for moving and wiping the cotton cloth. Specifically, as shown in FIG. 8A, first, a string 81 was tied to one end of the cable 10 (length 1 m), and the string 81 was routed around a pulley 82 and a guide pulley 83 and connected to a rotatable turntable 84. The cable 10 was suspended and a 400 g weight 85 was tied to the lower end. Thereby, the cable 10 was held so as to be able to move up and down in the vertical direction by the rotation of the turntable 84. Then, a cotton gauze cloth (length in the wiping direction of the cotton cloth: 50 mm) was wound around the surface of the coating 14 of the cable 10 as the cotton cloth 86. The cotton cloth 86 was previously impregnated with disinfectant ethanol (containing 75% - 80% ethanol). Subsequently, the wound cotton cloth 86 was held so as to be covered with wiper holders 87, 87 (hereinafter also simply referred to as the holder 87) made of silicone rubber sponge, and 2×10 -3 MPa~4×10 -3The holder 87 was adjusted so that a shear stress of MPa was applied. Subsequently, the cable 10 was reciprocated vertically with respect to the holder 87 to wipe the surface (coating 14) of the cable 10 with the cotton cloth 86 held by the holder 87. In this embodiment, as shown in FIG. 8B, the length X of the cotton cloth 86 in the wiping direction was 50 mm, the length Y (travel distance Y) of wiping the surface of the cable 10 with the cotton cloth 86 was 150 mm, and the one-way travel distance of the cotton cloth 86 was set to 200 mm. Also, the cable 10 was reciprocated 40 to 60 times per minute so that the wiping speed of the surface of the coating 14 was 80 to 120 times per minute (40 cycles per minute to 60 cycles per minute). Further, the cotton cloth 86 was replaced with a new one every 500 reciprocations of the cable 10 with respect to the cotton cloth 86. In this embodiment, after performing the wiping operation 20,000 times (10,000 reciprocations), the static friction coefficient of the surface of the coating was measured, and the difference in the static friction coefficient before and after the test ((<static friction coefficient after the test> - <static friction coefficient before the test>)) was calculated. If the difference (absolute value) was 0.1 or less, it was evaluated that the coating was less damaged by wiping and had excellent wiping resistance. The environmental temperature at the repeated wiping test site was 25 ± 3°C, and the environmental humidity was 50 ± 10%.

[0106] Note that, as the cotton cloth 86, a long-fiber non-woven fabric using cotton linter, "Venkot Regular Type (M-3II), size 250 mm × 250 mm, 4-fold specification" manufactured by Asahi Kasei Corporation was used. First, one Venkot (4-fold) was spread out, and a size of 50 mm × 175 mm was cut out from the 250 mm × 250 mm size. Disinfectant alcohol (about 2.5 ml) was evenly dripped onto the entire surface of the cut-out Venkot with a dropper and impregnated. Next, this Venkot was wound around the cable 10 so that the long side of the Venkot impregnated with the disinfectant alcohol was aligned with the circumferential direction of the cable 10 (about 7 turns). Note that the number of turns of the Venkot was adjusted so that the length of the cut-out long side of the Venkot was wound about 7 turns in accordance with the outer diameter of the cable.

[0107] In the wiping test, in order to maintain the impregnated state of the cotton cloth 86 with alcohol, after reciprocating the cotton cloth 86 250 times, 2.5 ml of disinfection alcohol was dropped onto the cotton cloth 86 for supply. This droplet was formed by dripping and impregnating the disinfection alcohol along the circumferential direction of the cable 10 onto the upper end portion of the cotton cloth 86 held by the holder 87 with a dropper. The addition amount of the disinfection alcohol should be an amount such that the cotton cloth does not dry due to volatilization or the like when the cotton cloth is reciprocated 250 times in the wiping test. In this example, it was adjusted to 2.5 ml so as not to dry.

[0108] Also, the force (shearing stress) when the cotton cloth 86 is brought into contact with the cable 10 was adjusted as follows. The cotton cloth 86 wound around the cable 10 produced by the above method is held so as to be covered with the wiper holders 87, 87. Next, one end of the held cable 10 is horizontally pulled with a push-pull gauge, and the force when the cable 10 starts to move with respect to the wiper holders 87, 87 is divided by the surface area of the cable 10 covered by the wiper holders 87, 87 (in this example, length 50 mm × outer circumference 25 mm), and the shearing stress is 2×10 -3 MPa to 4×10 -3 MPa. The holders 87, 87 used silicone sponges, and recesses were provided at the portions where the cable 10 wound with the cotton cloth 86 abuts. The recesses were processed so as to form a cylinder when the holders 87, 87 were combined. When the shearing stress deviated from the predetermined numerical range, the holding force (clamping force) of the wiper holders 87, 87 was adjusted by the size (diameter) of the recessed portions (the holding portions of the cable 10) of the holders 87, 87. In addition, the shearing stress was adjusted every time the cotton cloth 86 was replaced.

[0109] The weight 85 is a driving source for moving the cable 10 downward (free fall). The weight may be set such that the time required for the cotton cloth 86 to move downward by 200 mm is 0.67 seconds per cycle to 1 second per cycle (40 cycles per minute to 60 cycles per minute). Here, when adjusting the shear stress, one end of the held cable 10 is horizontally pulled with a push-pull gauge, and the weight is set to 1.5 times to 2 times the force (the product of the shear stress and the surface area of the cable 10 covered by the wiper holders 87, 87) when the cable 10 starts to move with respect to the wiper holders 87, 87.

[0110] (Surface unevenness) Regarding the surface unevenness of the coating film, the surface of the coating film was observed with an electron microscope and evaluated from the number of fine particles and voids present per unit area and the number distribution of the fine particles.

[0111] The number of fine particles and voids per unit area was calculated by observing the surface of the coating film with an electron microscope.

[0112] For the number distribution of the fine particles, first, the surface of the coating film was photographed at a magnification of 1000 times, four regions of 40 μm × 40 μm were arbitrarily selected, the number of fine particles present in each region was counted, and the number per unit area was calculated. Then, among the numbers of the four regions, with the maximum value being Nmax and the minimum value being Nmin, the number distribution calculated by the formula ((Nmax - Nmin) / (Nmax + Nmin)) × 100 was calculated. In this example, if the calculated value is 5% or less, it was evaluated that the variation in the number of fine particles is small.

[0113] (Evaluation results) The evaluation results are summarized in Table 1. As shown in Table 1, in Examples 1 to 4, it was confirmed that the static friction coefficient of the coating film was 0.5 or less and the slidability was excellent. Also, 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.

[0114] Also, regarding the wiping resistance, it was confirmed that even after repeated wiping, the static friction coefficient did not significantly fluctuate from before the test, and the difference before and after the test was 0.1 or less. Here, regarding the coating of Example 1, the change in the static friction coefficient due to the wiping operation will be specifically described with reference to a figure. FIG. 9 is a diagram showing the change in the static friction coefficient of the coating with the number of wiping times. The horizontal axis represents the number of wiping times [times], and the vertical axis represents the static friction coefficient of the coating. In FIG. 9, regarding the change in the static friction coefficient of the coating, Example 1 is represented by a circle (〇), Example 2 by a square (□), Example 3 by a triangle (△), Comparative Example 1 by a diamond (◇), and Comparative Example 2 by a cross (×) plot. As a reference example, the plot of the static friction coefficient of the coating made of PVC is represented by an asterisk (*). As shown in FIG. 9, the static friction coefficient of the coating of Example 1 was 0.16 before the wiping test and 0.17 after 20,000 wipes, and it was confirmed that the difference was 0.01. Also, the static friction coefficient of the coating of Example 2 was 0.14 before the wiping test and 0.15 after 20,000 wipes, and the difference was 0.01. The static friction coefficient of the coating of Example 3 was 0.16 before the wiping test and 0.19 after 20,000 wipes, and it was confirmed that the difference was 0.03. The static friction coefficient of the coating of Example 4 was 0.16 before the wiping test and 0.18 after 20,000 wipes, and it was confirmed that the difference was 0.02. That is, even after 20,000 wipes, the static friction coefficient did not significantly fluctuate, the slipperiness could be maintained at a high level, and it was confirmed that the wiping resistance was excellent. Moreover, it was also confirmed that the static friction coefficient could be maintained lower than that of the PVC coating.

[0115] In contrast, in Comparative Example 1, although it has excellent slidability, it was confirmed that not only the adhesion strength between the sheath and the coating is low, but also the wiping resistance of the coating is low. Specifically, the adhesion strength was 0.22 MPa, and the boot peeled off by the bending test. Also, as shown by the ◇ plot in Fig. 9, the static friction coefficient of the coating in Comparative Example 1 was 0.16 before the wiping test and 0.45 after 20,000 wipes, with a difference of 0.29. In Comparative Example 1, the static friction coefficient of the coating gradually increased by repeating the wiping, and the slidability could not be maintained. That is, it was confirmed that the coating in Comparative Example 1 is inferior in wiping resistance.

[0116] In Comparative Example 2, although it has excellent slidability and adhesion strength between the sheath and the coating, it was confirmed that the wiping resistance of the coating is lower than that of the Examples. Also, as shown by the × plot in Fig. 9, the static friction coefficient of the coating in Comparative Example 2 was 0.17 before the wiping test and 0.30 after 20,000 wipes, with a difference of 0.13. In Comparative Example 2, the static friction coefficient of the coating gradually increased by repeating the wiping, and the slidability could not be maintained. That is, it was confirmed that the coating in Comparative Example 2 is inferior in wiping resistance to the Examples.

[0117] 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.

[0118] For each of the examples and comparative examples, when the surface unevenness and cross-section of the coating before the wiping test were confirmed, it was confirmed that the surface of the coating was in the state shown in FIGS. 10 to 13. FIG. 10A is an SEM image of the surface of the coating of Example 1. FIG. 10B is an SEM image of the cross-section of the coating of Example 1. FIG. 11A is an SEM image of the surface of the coating of Comparative Example 1. FIG. 11B is an SEM image of the cross-section of the coating of Comparative Example 1. FIG. 12 is an SEM image of the surface of the coating of Example 3. FIG. 13 is an SEM image of the surface of the coating of Comparative Example 2. Comparing these figures, in the coatings of Example 1 and Example 3, the fine particles were densely distributed, while in Comparative Example 1, it was confirmed that not only fine particles but also depressions (the portions shown in black in the figure) were present. Also, in the coating of Comparative Example 1, bubbles (voids) were present over a wide range on the surface in contact with the sheath of the coating, while in the coating of Example 1, it was confirmed that the bubbles (voids) were reduced compared to Comparative Example 1. In Comparative Example 2, although no bubbles were confirmed, it was found that the fine particles present on the surface were few and their distribution was sparse.

[0119] Based on the SEM images, when the number of fine particles was counted, in Example 1, there were 94 to 96 per 1600 μm 2 (40 μm square), in Example 2 there were 98 to 101, in Example 3 there were 74 to 79, and in Example 4 there were 77 to 81, while in Comparative Example 1 there were 42 to 52 and in Comparative Example 2 there were 38 to 58. That is, the number of distributed fine particles in the examples was larger than that in the comparative examples. Also, in Examples 1 to 4, there were substantially no voids with a size of 1 μm or more, while in Comparative Example 1, at least 40 voids with a size of 1 μm or more were present within the range of a 40 μm square. Furthermore, when the number distribution was obtained from the number of fine particles in each region, it was 1.05% in Example 1, 1.51% in Example 2, 3.27% in Example 3, and 2.53% in Example 4, and all had a small variation in the number distribution of 5% or less. In contrast, in Comparative Example 1, the number distribution was 10.6%, and in Comparative Example 2, the number distribution was 19.6%, and the distribution of fine particles in the coating was not uniform and had a large variation.

[0120] Furthermore, when the surface profiles of the coatings of Example 1 and Comparative Example 1 were obtained, the results shown in FIGS. 14 and 15 were obtained. FIG. 14 is a diagram showing the surface profile of the coating of Example 1. FIG. 15 is a diagram showing the surface profile of the coating of Comparative Example 1. As shown in FIG. 14, in the coating of Example 1, no depression due to voids was confirmed, and it was confirmed that there were more protrusions due to fine particles than depressions due to depressions. On the other hand, in Comparative Example 1, as shown in FIG. 15, it was confirmed that there were many recesses due to depressions on the surface of the coating.

[0121] The depressions formed in the coating are caused by bubbles generated during the condensation reaction when curing the condensation reaction type silicone rubber. According to this depression, when wiping the coating with a cotton cloth, the cotton cloth is likely to be caught at the edge of the depression, so the coating is likely to be damaged by wiping. As a result, in Comparative Example 1, it is presumed that the static friction coefficient is likely to increase due to the fine particles falling off or the like by wiping, and the slipperiness cannot be maintained for a long time. In addition, it is presumed that the contact area decreases due to the presence of voids on the contact surface between the coating and the sheath, and the adhesion strength decreases.

[0122] In this regard, in this example, by using an addition reaction type silicone rubber, generation of bubbles during curing is suppressed, and depressions on the coating surface and voids in the coating are reduced. Preferably, when applying the paint by the dipping method, the self-arrangement of fine particles is promoted by adjusting the pulling speed of the cable. According to Example 1 and Comparative Example 2, it was found that the variation in the distribution of fine particles in the coating changed greatly depending on the pulling speed of the cable. In Comparative Example 2, since the pulling speed of the cable was excessively fast, the self-arrangement of fine particles was not promoted, and the number of fine particles per unit area was 38 to 58, and the distribution of fine particles was sparser than that of Example 1 (94 to 96). Moreover, the number distribution of fine particles was also 19.6%, and it was found that the variation in the distribution was larger than 1.05% of Example 1. As a result, in Comparative Example 2, it is presumed that the static friction coefficient is likely to increase due to the fine particles falling off or the like by wiping, and the slipperiness could not be maintained for a long time.

[0123] Also, according to Examples 1 and 3, by adding fumed silica to the rubber composition, fine particles can be more densely distributed on the coating surface, and a coating excellent in slidability, adhesion to the sheath, and wiping resistance can be obtained.

[0124] Comparing Examples 3 and 4, it was confirmed that by incorporating an infrared absorber into the sheath as in Example 4, the adhesion strength at the interface between the coating and the sheath can be made higher than that in Example 3 without the infrared absorber.

[0125] <Preferred Embodiment of the Present Invention> Hereinafter, preferred embodiments of the present invention will be appended.

[0126] (Appendix 1) According to one embodiment of the present invention, a sheath, a coating that covers the periphery of the sheath and is provided in close contact with the sheath, and the coating is formed from a rubber composition containing a rubber component and fine particles, and the coefficient of static friction on the surface of the coating is 0.5 or less. When a long fiber nonwoven fabric (length in the wiping direction: 50 mm) using cotton linter containing alcohol for disinfection is brought into contact with the surface of the coating so that a shear stress of 2×10 -3 MPa to 4×10 -3 MPa acts, and the surface of the coating is wiped 20,000 times at a length of 150 mm in the wiping direction and a speed of 80 to 120 times per minute, the difference (absolute value) in the coefficient of static friction of the coating before and after the test is 0.1 or less, and the coating has wiping resistance. a cable is provided.

[0127] (Appendix 2) In the embodiment of Appendix 1, the adhesion strength between the sheath and the coating is 0.30 MPa or more.

[0128] (Appendix 3) In the aspect of Supplementary Note 1 or 2, the rubber component is at least one of silicone rubber and chloroprene rubber.

[0129] (Supplementary Note 4) In the aspect of Supplementary Notes 1 to 3, the rubber component is silicone rubber, and the fine particles are at least one of silicone resin fine particles, silicone rubber fine particles, and silica fine particles.

[0130] (Supplementary Note 5) In the aspect of Supplementary Notes 1 to 4, the fine particles have a higher hardness than the rubber component.

[0131] (Supplementary Note 6) In the aspect of Supplementary Notes 1 to 5, the average particle diameter of the fine particles is 1 μm or more and 10 μm or less.

[0132] (Supplementary Note 7) In the aspect of Supplementary Notes 1 to 6, the thickness of the coating film is 3 μm or more and 100 μm or less.

[0133] (Supplementary Note 8) In the aspect of Supplementary Notes 1 to 7, the sheath is formed of silicone rubber.

[0134] (Supplementary Note 9) In the aspect of Supplementary Notes 1 to 6, the rubber component is an addition reaction type silicone rubber.

[0135] (Supplementary Note 10) In the aspect of Supplementary Notes 1 to 9, When the number of the fine particles per unit area is measured at any plurality of positions on the surface of the coating film, the number distribution calculated by the formula (Nmax - Nmin) / (Nmax + Nmin)×100 from the maximum value Nmax and the minimum value Nmin of the number is 5% or less.

[0136] (Supplementary Note 11) In the aspects of Supplementary Notes 1 to 10, on the surface of the coating, the number of voids having a size of 1 μm or more present per unit area is 5 or less per 40 μm square.

[0137] (Supplementary Note 12) In the aspects of Supplementary Notes 1 to 11, the rubber composition contains the fine particles in a range of 10% by mass or more and 60% by mass or less based on the total of the rubber component and the fine particles.

[0138] (Supplementary Note 13) In the aspects of Supplementary Notes 1 to 12, the cable is connectable to a medical device.

[0139] (Supplementary Note 14) In the aspects of Supplementary Notes 1 to 13, the sheath further contains an infrared absorber.

[0140] (Supplementary Note 15) In the aspect of Supplementary Note 14, the content of the infrared absorber is 0.1% by mass to 10% by mass with respect to 100 parts by mass of the sheath component.

[0141] (Supplementary Note 16) In the aspects of Supplementary Note 14 or Supplementary Note 15, the infrared absorber is a titanium oxide.

[0142] (Supplementary Note 17) According to another aspect of the present invention, a hollow tube body, a coating 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, and the coating is formed from a rubber composition containing a rubber component and fine particles, and the static friction coefficient on the surface of the coating is 0.5 or less. A long-fiber nonwoven fabric (50 mm in length in the wiping direction) using cotton linter containing alcohol for disinfection is brought into contact with the surface of the coating film so that a shear stress of 2×10 -3 MPa to 4×10 -3 MPa acts, and when a test of repeatedly wiping the surface of the coating film 20,000 times at a length of 150 mm in the wiping direction and a speed of 80 to 120 times / min is performed, the difference (absolute value) in the static friction coefficient of the coating film before and after the test is 0.1 or less, and it has wiping resistance, A medical hollow tube or a hollow tube is provided.

[0143] (Appendix 18) In the aspect of Appendix 17, The hollow tube body further contains an infrared absorber.

[0144] (Appendix 19) In the aspect of Appendix 18, The content of the infrared absorber is 0.1% by mass to 10% by mass with respect to 100 parts by mass of the hollow tube body component.

[0145] (Appendix 20) In the aspect of Appendix 18 or Appendix 19, The infrared absorber is a titanium oxide.

[0146] (Appendix 21) According to another aspect of the present invention, A molded body main body, A coating film that covers the surface of the molded body main body and is in close contact with the main body, and The coating film is formed from a rubber composition containing a rubber component and fine particles, and the static friction coefficient on the surface of the coating film is 0.5 or less. On the surface of the coating film, a long-fiber nonwoven fabric (50 mm in length in the wiping direction) using cotton linter containing alcohol for disinfection is brought into contact with the surface of the coating film so that a shear stress of 2×10 -3 MPa to 4×10 -3It was brought into contact so that a shear stress of MPa was applied, and a test was conducted in which the surface of the coating was wiped 20,000 times at a length of 150 mm in the wiping direction and a speed of 80 to 120 times per minute. When the difference (absolute value) in the static friction coefficient of the coating before and after the test was 0.1 or less, it had wiping resistance. A molded body is provided.

[0147] (Appendix 22) In the aspect of Appendix 21, The molded body main body further contains an infrared absorber.

[0148] (Appendix 23) In the aspect of Appendix 22, The content of the infrared absorber is 0.1 mass% to 10 mass% with respect to 100 mass parts of the molded body main body components.

[0149] (Appendix 24) In the aspect of Appendix 22 or Appendix 23, The infrared absorber is a titanium oxide.

Explanation of symbols

[0150] 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 part 33 Concave part (depression) 34 Void 50 Sample cable 51 Adhesive 52 Boot material tube 53 Sheath material tube 54 Sample for evaluating adhesion strength 60 Probe Cable 61 Boot 70 Medical Hollow Tube 71 Hollow Tube Body 72 Outer Coating 73 Inner Coating

Claims

1. A cable, a boot attached to an end of the cable, and a cable with a boot, comprising: The jacket of the cable includes a sheath and an outermost layer provided in close contact with the sheath, the outermost layer includes an addition reaction type silicone rubber added with fine particles, and the static friction coefficient on its surface is 0.5 or less, the adhesion strength between the sheath and the outermost layer is 0.30 MPa or more, when a bending test is performed in which the boot portion of the cable with a boot is held and bent left and right, peeling or breakage of the boot does not occur less than 150,000 times, A cable with a boot. In addition, in the bending test, the attachment area of the outermost layer and the boot is 250 mm ２ while a load of 500 g is applied to the end portion on the side opposite to the said end portion, the holding portion is kept in 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. One series of such bending operations is counted as one time, and the bending operation is performed at a speed of 30 times per minute.

2. The sheath includes an addition reaction type silicone rubber, The cable with a boot according to Claim 1.

3. The outermost layer of the cable and the boot are attached by a silicone-based adhesive or an epoxy-based adhesive, The cable with a boot according to Claim 1 or 2.

4. The boot includes an addition reaction type silicone rubber, The cable with a boot according to any one of Claims 1 to 3.

5. The fine particles are at least one of silicone resin fine particles, silicone rubber fine particles, and silica fine particles, The cable with a boot according to any one of Claims 1 to 4.

6. The fine particles have a higher hardness than the rubber component of the silicone rubber contained in the outermost layer, The cable with a boot according to any one of Claims 1 to 5.

7. The average particle size of the fine particles is 1 μm or more and 10 μm or less, The cable with a boot according to any one of Claims 1 to 6.

8. The thickness of the outermost layer is 3 μm or more and 100 μm or less, The cable with a boot according to any one of Claims 1 to 7.

Images