JP2005224538A - Flexible tube for endoscope and endoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible tube for an endoscope having appropriate flexibility (bendability) and excellent in heat resistance, chemical resistance and wear resistance, and an endoscope provided with the flexible tube for the endoscope. <P>SOLUTION: An insertion part flexible tube (flexible tube for the endoscope) 1 is provided with a tubular core material 2 and a jacket 3 coated on the outer periphery of the core material 2. The jacket 3 is constituted of a layered body having at least two layers. The layered body is provided with an inner layer (first layer) 31 constituted of a material containing a polyolefin based thermoplastic elastomer or a styrene-ethylene-butylene-styrene block copolymer as a main material and an outermost layer (second layer) 32 constituted of a material containing polymethylpentene as a main material. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an endoscope flexible tube and an endoscope.

  In endoscopy, it is necessary to insert the insertion tube flexible tube of an endoscope to a deep part of a body cavity such as the stomach, duodenum, small intestine or large intestine.

  This insertion portion flexible tube has a tubular core material and an outer skin coated on the outer periphery thereof, and by selecting the constituent material of the outer skin, the insertion operation is easy (flexible). Improvements are made to reduce the burden on the patient, and liquids such as body fluids are prevented from entering the inside.

  Conventionally, elastic materials such as urethane elastomers are generally used as the constituent material of the outer skin (see, for example, Patent Document 1).

  By the way, since an endoscope is repeatedly used, it is necessary to perform cleaning and disinfection each time. However, a urethane-based elastomer has a problem of being inferior in heat resistance and chemical resistance.

  For this reason, if the endoscope is repeatedly cleaned, disinfected, sterilized, etc., the insertion portion flexible tube (endoscopic flexible tube) may deteriorate in its outer skin and may be less flexible. It was. In this case, it becomes difficult to insert the insertion portion flexible tube into the body cavity (lumen), which hinders the operation of the endoscope.

  In addition, when the outer skin of the insertion portion flexible tube is severely deteriorated, there is a concern that a fine crack or the like occurs, and the outer skin peels off from the core material and flows into the body cavity.

Japanese Examined Patent Publication No. 7-110270 (page 1, right column, lines 2-8)

  An object of the present invention is to provide an endoscope flexible tube having moderate flexibility (flexibility) and excellent in heat resistance, chemical resistance, and wear resistance, and the endoscope flexibility. An object of the present invention is to provide an endoscope including a tube.

Such an object is achieved by the present inventions (1) to (19) below.
(1) A flexible tube for an endoscope having a tubular core material and an outer skin coated on the outer periphery of the core material,
The outer skin is composed of a laminate having at least two layers,
The laminate includes a first layer composed mainly of a material containing a polyolefin-based thermoplastic elastomer or a styrene-ethylene butylene-styrene block copolymer, and a material containing polymethylpentene. A second layer,
The flexible tube for an endoscope, wherein the second layer is an outermost layer.

  Thereby, it has moderate softness | flexibility (flexibility), and can be made excellent in heat resistance, chemical resistance, and abrasion resistance.

(2) The flexible tube for an endoscope according to the above (1), wherein the second layer is made of a material containing at least one of a thermoplastic elastomer and a polyolefin in addition to the polymethylpentene. .
Thereby, the adhesiveness of a 2nd layer and a 1st layer can be aimed at.

  (3) The thermoplastic elastomer contained in the material constituting the second layer is mainly composed of at least one of a polyolefin-based thermoplastic elastomer and a styrene-ethylene-butylene-styrene block copolymer (2 The flexible tube for endoscopes as described in 1.).

  Since these have excellent affinity (compatibility) with polymethylpentene, the second layer having a uniform thickness can be formed, and the adhesion with the first layer is higher. Two layers are obtained.

(4) The flexible tube for an endoscope according to any one of (1) to (3), wherein the content of the polymethylpentene in the material constituting the second layer is 50 wt% or more.
As a result, the wear resistance is improved.

(5) The content of the polyolefin-based thermoplastic elastomer or the styrene-ethylene-butylene-styrene block copolymer in the material constituting the first layer is 50 wt% or more (1) to (4) The flexible tube for an endoscope according to any one of the above.
Thereby, it becomes more excellent in chemical resistance and heat resistance.

(6) The first layer is composed mainly of a material containing both the polyolefin-based thermoplastic elastomer and the styrene-ethylene-butylene-styrene block copolymer,
The total content of the polyolefin-based thermoplastic elastomer and the styrene-ethylene-butylene-styrene block copolymer in the material is 50 wt% or more, according to any one of (1) to (5) above. Flexible tube for endoscope.
Thereby, it becomes more excellent in chemical resistance and heat resistance.

  (7) When the average thickness of the first layer is a [mm] and the average thickness of the second layer is b [mm], b / a satisfies the relationship of 0.025 to 1. The flexible tube for an endoscope according to any one of (1) to (6) above.

  Thereby, it has more moderate flexibility and is more excellent in chemical resistance, heat resistance and wear resistance.

  (8) The flexible tube for an endoscope according to any one of (1) to (7), wherein an average thickness of the second layer is 0.01 to 0.5 mm.

  Thereby, the flexible tube for endoscopes is more excellent in wear resistance while maintaining appropriate flexibility.

  (9) The flexible tube for an endoscope according to any one of (1) to (8), wherein an average thickness of the outer skin is 0.08 to 0.9 mm.

  Thereby, it is possible to more reliably protect the core member and each member disposed in the core member from liquids such as body fluids while preventing a decrease in curvature.

  (10) The flexible tube for an endoscope according to any one of (1) to (9), wherein the first layer and the second layer are adjacent to each other.

  Thereby, it can prevent more reliably that peeling from the 1st layer of a 2nd layer arises.

(11) The second layer has optical transparency.
The first layer is TiN _x O _y (provided that 0.1 ≦ x ≦ 1.0, 0 ≦ y ≦ 1) as a color former that develops color by irradiation with laser light at least in the vicinity of the outer surface. .9) and a flexible tube for an endoscope as described in (10) above, wherein a color development portion formed by color development of the color former is formed.

  As a result, the protective function of the coloring portion by the second layer is exhibited, and the coloring portion is prevented from peeling, disappearing, fading, and the like and the deterioration of the vicinity of the coloring portion on the outer surface of the first layer due to the formation thereof. can do.

(12) The flexible tube for an endoscope according to (11), wherein the color former is in a particulate form.
Thereby, the color former can be more uniformly mixed (dispersed) in the first layer.

(13) The flexible tube for an endoscope according to (12), wherein the particulate color former has an average particle size of 10 μm or less.
Thereby, the dispersion state of the color former in the first layer can be made more uniform.

(14) The first layer has a color former-containing region containing the color former,
The flexible tube for an endoscope according to any one of (11) to (13), wherein the content of the color former in the color former-containing region is 0.01 to 10 wt%.
Thereby, a color development part can be made clear.

(15) The flexible tube for an endoscope according to any one of (11) to (14), wherein the color of the outer surface of the first layer before irradiation with laser light is black or dark.
Thereby, a color development part can be made clearer.

(16) The flexible tube for an endoscope according to any one of (11) to (15), wherein the color of the color developing portion is white or light.
Thereby, a color development part can be made clearer.

(17) The flexible tube for an endoscope according to (16), wherein the whiteness (L value) of the coloring portion is 60% or more.
When the whiteness is too small, good visibility of the color development portion cannot be obtained.

  (18) The flexible tube for an endoscope according to any one of (11) to (17), wherein the coloring portion is a scale indicating an insertion depth of the flexible tube for an endoscope.

  When the endoscope flexible tube of the present invention is applied to a medical endoscope, a more accurate and safe endoscopic examination can be performed.

  (19) An endoscope comprising the endoscope flexible tube according to any one of (1) to (18).

  When the endoscope of the present invention is applied to a medical endoscope, more accurate and safe endoscopy can be performed.

  As described above, according to the present invention, it has moderate flexibility and exhibits excellent heat resistance, chemical resistance, and wear resistance.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an endoscope flexible tube and an endoscope according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

<Endoscope>
First, the endoscope of the present invention will be described.

  FIG. 1 is an overall view showing an embodiment when the endoscope of the present invention is applied to an electronic endoscope (electronic scope). Hereinafter, in FIG. 1, the upper side is described as “base end” and the lower side is described as “tip”.

  As shown in FIG. 1, an electronic endoscope 10 is provided at a long insertion portion flexible tube 1 having flexibility (softness) and a proximal end portion of the insertion portion flexible tube 1. An operation unit 6 that the operator holds and operates the entire electronic endoscope 10, a connection portion flexible tube 7 connected to the operation unit 6, and a light source difference provided on the distal end side of the connection portion flexible tube 7 It is comprised with the insertion part 8. FIG.

  The insertion portion flexible tube 1 includes a main portion 11 and a bending portion 12 connected to the distal end side of the main portion 11.

  The insertion section flexible tube 1 is formed with a scale (visual marker) 9 indicating the insertion depth along the longitudinal direction.

  The insertion portion flexible tube 1 and the connection portion flexible tube 7 are each a flexible tube for an endoscope in which the outer periphery of a (tubular) core material having a hollow portion is covered with an outer skin, as will be described later. That is, it is configured by the endoscope flexible tube of the present invention.

  The operation unit 6 is provided with operation knobs 61 and 62 on its side surface. When the operation knobs 61 and 62 are operated, a wire (not shown) disposed in the insertion portion flexible tube 1 is pulled, and the bending portion 12 is bent in four directions, and the directions can be changed. .

  An imaging element (CCD) (not shown) that captures a subject image at the observation site is provided inside the distal end portion of the bending portion 12, and an image signal connector 82 is provided at the distal end portion of the light source insertion portion 8. Yes. The image signal connector 82 is connected to a light source processor device (not shown) connected to a monitor device (not shown) via a cable. In addition, a light source connector 81 is installed at the tip of the light source insertion portion 8, and the light source connector 81 is connected to the light source processor device.

  The light emitted from the light source processor device is continuously arranged in the light source connector 81 and the light source insertion portion 8, the connection portion flexible tube 7, the operation portion 6, and the insertion portion flexible tube 1. Through the light guide (not shown), the observation site is irradiated and illuminated from the distal end of the bending portion 12 (insertion portion flexible tube 1). Such a light guide is configured by bundling a plurality of optical fibers made of, for example, quartz, multicomponent glass, plastic, or the like.

  The reflected light (subject image) from the observation site illuminated by the illumination light is imaged by the image sensor. The image sensor outputs an image signal corresponding to the captured subject image. This image signal is continuously arranged in the insertion portion flexible tube 1, the operation portion 6, and the connection portion flexible tube 7, and is connected to the image sensor and the image signal connector 82. (Not shown) is transmitted to the light source insertion unit 8.

  Then, predetermined processing (for example, signal processing, image processing, etc.) is performed in the light source insertion unit 8 and the light source processor device, and then input to the monitor device. In the monitor device, an image (electronic image) captured by the image sensor, that is, an endoscope monitor image of a moving image is displayed.

<Flexible tube for endoscope>
Next, the endoscope flexible tube of the present invention will be described.

  As described above, the endoscope flexible tube of the present invention can be applied to the insertion portion flexible tube 1 and the connection portion flexible tube 7, respectively. The case will be described as a representative.

  FIG. 2 is an enlarged view showing a longitudinal section of a main part of an insertion portion flexible tube included in the electronic endoscope shown in FIG.

  As shown in FIG. 2, the insertion portion flexible tube 1 has a core material 2 and an outer skin 3 that covers the outer periphery thereof. In the space 24 of the insertion portion flexible tube 1 (core material 2), for example, a long member (not shown) such as an optical fiber, an electric cable, a cable, or a tube is disposed.

  The core material 2 corresponding to the main portion 11 includes a spiral tube 21 and a mesh tube (braided body) 22 covering the outer periphery of the spiral tube 21, and although not shown, the core material corresponding to the curved portion 12. 2 is composed of a plurality of (many) node rings connected to each other so as to be rotatable, and a net-like tube covering the outer periphery of the node ring, and the core material 2 constitutes a tubular long object as a whole. doing.

  The spiral tube 21 is formed by winding a strip-like material in a spiral manner with an interval 25 therebetween. Further, the inner diameter of the spiral tube 21 is set to be substantially uniform over the entire length thereof. As the constituent material of the spiral tube 21 and the node ring, for example, stainless steel, copper alloy, etc. are preferably used.

  The mesh tube (mesh tube 22 or the like) is formed by braiding a plurality of metal or non-metal thin wires 23 arranged side by side. As a constituent material of the thin wire 23, for example, stainless steel, copper alloy or the like is preferably used. Further, at least one of the fine wires 23 constituting the mesh tube may be covered with a resin material.

  A gap 26 is formed on the outer periphery of the mesh tube 22 by the stitches of the braided thin wires 23. The gap 26 becomes a concave portion at a position overlapping the outer periphery of the spiral tube 21, and becomes a hole communicating with the space 24 at a position overlapping the interval 25 of the spiral tube 21, thereby forming a large number of holes and concave portions on the outer periphery of the core material 2. doing.

Further, inside the core material 2 (insertion section flexible tube 1), for example, molybdenum disulfide, boron nitride (BN), tetrafluoroethylene polymer (fluorine resin), graphite, fluorocarbon ((CF _N ) A solid lubricant such as _n ) is disposed. This solid lubricant is arranged around the long member as described above. Thereby, the sliding resistance (friction resistance) between each elongate member or between each elongate member and the core material 2 can be made small. For this reason, when the insertion portion flexible tube 1 (the main portion 11 and the bending portion 12) is bent, the long member is smoothly moved in the longitudinal direction (axial direction) of the core member 2, and the bending resistance thereof is increased. Is small. Further, pulling, compression, and buckling of the optical fiber constituting the light guide are suppressed, and as a result, damage, breakage, and the like can be effectively prevented.

  An outer skin 3 is coated on the outer periphery of the core material 2. The outer skin 3 is a part that directly contacts the inner wall of a tubular organ such as the digestive tract, and has a function of preventing body fluid or the like from entering the insertion portion flexible tube 1.

  A large number of protrusions (anchors) 4 are formed on the inner surface of the outer skin 3 so as to protrude inward from the outer skin 3. Each protrusion 4 enters into a large number of holes and recesses formed on the outer periphery of the core member 2. The tip of the protrusion 4 that has entered the recess is formed until it reaches the outer periphery of the spiral tube 21. Further, the protruding portion 4 that has entered the hole is formed longer, and the tip thereof enters the interval 25 of the spiral tube 21.

  An anchor effect is produced by these protrusions 4, and the outer skin 3 is securely fixed to the core material 2. For this reason, even when the insertion portion flexible tube 1 is curved, the outer skin 3 is kept in close contact with the core material 2 and expands and contracts sufficiently large according to the curvature of the core material 2. The restoring force of the outer skin 3 that is greatly expanded and contracted in this way is strongly exerted and greatly contributes to the force for restoring the bending of the insertion portion flexible tube 1.

  Moreover, since the bonding force between the outer skin 3 and the mesh tube 22 is strong by forming the protruding portion 4, the outer skin 3 is difficult to peel off from the mesh tube 22 even when used repeatedly. Therefore, the insertion portion flexible tube 1 is excellent in durability.

  When using what coated at least 1 of the thin wires 23 which comprise the reticular tube 22 with a resin material, at least one part of this coated resin material (coating layer) fuse | melts and it is in the outer skin 3 Bond (weld).

  Such an outer skin 3 has chemical resistance and heat resistance because it is exposed to chemicals such as various disinfectants and high temperature and pressure during repeated disinfection and sterilization treatment, and the body cavity is caused by friction. In order to prevent damage to the internal tissue, a material having flexibility (flexibility) is preferably used as a main material.

  As a result of intensive investigations, the inventors of the present invention have a structure in which the outer skin 3 is composed of a laminate in which at least two layers are laminated, and the laminate is a polyolefin-based thermoplastic elastomer (hereinafter abbreviated as “TPO”) or. A first layer composed mainly of a material containing a styrene-ethylene-butylene-styrene block copolymer (hereinafter abbreviated as “SEBS”), and polymethylpentene (hereinafter abbreviated as “PMP”). By having a second layer (outermost layer) composed mainly of a material containing, the insertion portion flexible tube 1 has an appropriate chemical resistance (elasticity) and excellent chemical resistance, It has been found that heat resistance and wear resistance can be imparted, and the present invention has been completed.

  As shown in FIG. 2, the insertion portion flexible tube 1 of the present embodiment (the flexible tube for an endoscope of the present invention) 1 has an outer skin 3 and an inner layer (first layer) 31 and a light-transmitting outermost layer. It is composed of a laminate with an outer layer (second layer) 32. The inner layer 31 is composed of a material containing TPO or SEBS as a main material, and the outermost layer 32 is composed of a material containing PMP as a main material.

  In particular, in the present embodiment, the inner layer 31 composed mainly of a material containing TPO or SEBS and the outermost layer 32 composed mainly of a material containing PMP are adjacent to (in contact with) each other. TPO, SEBS, and PMP have an affinity for them, and the adhesion between the inner layer 31 and the outermost layer 32 can be made excellent. As a result, the outermost layer 32 peels from the inner layer 31. Can be more reliably prevented (a more stable skin 3 can be obtained).

  Here, when a material including SEBS is used as the material constituting the inner layer 31, the heat resistance of the insertion portion flexible tube 1 is improved. When the material which comprises the inner layer 31 contains SEBS, it is preferable that the content is 50 wt% or more, It is more preferable that it is 60 wt% or more, It is further more preferable that it is 70-100 wt%.

  In addition, when a material containing TPO is used as the material constituting the inner layer 31, chemical resistance and flexibility (flexibility) of the insertion portion flexible tube 1 are improved. When the material constituting the inner layer 31 includes TPO, the content thereof is preferably 50 wt% or more, more preferably 60 wt% or more, and further preferably 70 to 100 wt%.

  Further, when a material that includes both TPO and SEBS is used as the material constituting the inner layer 31, the heat resistance, chemical resistance, and flexibility (flexibility) of the insertion portion flexible tube 1 due to the synergistic effect thereof. Property) is remarkably excellent. When the material constituting the inner layer 31 includes both TPO and SEBS, the total content is preferably 50 wt% or more, more preferably 60 wt% or more, and 70 to 100 wt%. Is more preferable.

  TPO generally has a hard phase (hard segment) and a soft phase (soft segment). Examples of the material constituting the hard phase include polyethylene, polypropylene, and the like, and the hard phase is composed of one or more of these. Examples of the material constituting the soft phase include ethylene-propylene-diene copolymer rubber vulcanizate (EPDM), butyl rubber, chloroprene, etc., and the soft phase is one or more of these. It is configured.

  The average thickness of the inner layer 31 (excluding the protruding portion 4) is not particularly limited, but is preferably about 0.05 to 0.8 mm, and more preferably about 0.05 to 0.4 mm.

  Furthermore, the material constituting the inner layer 31 may include PMP. When the material constituting the inner layer 31 contains PMP, the adhesion with the outermost layer 32 described later is further improved, and the outer skin 3 as a whole has appropriate elasticity (elasticity). it can.

  When the material which comprises the inner layer 31 contains PMP, it is preferable that the compounding quantity of PMP is 0.1-20 weight part with respect to 100 weight part of TPO, SEBS, or these in total, 1-10 weight part More preferably, it is part. Thereby, the above-mentioned effect becomes more remarkable.

  Further, in the present embodiment, the inner layer 31 contains a color former that develops color when irradiated with laser light. As shown in FIG. A light-colored scale (coloring portion) 9 is formed (provided).

  In the present embodiment, the scale 9 has a function of indicating the insertion depth of the insertion portion flexible tube 1 into the body cavity, and as shown in FIG. 1, along the longitudinal direction of the insertion portion flexible tube 1, It is composed of line segments (width of about 1 to 10 mm) formed at intervals (pitch) of 10 cm and numbers formed in the vicinity of the line segments. The interval between the line segments can be arbitrarily set.

  Further, instead of such a scale 9 or in combination with the scale 9, a visual marker (coloring portion) having another shape can be provided. As the visual recognition marker of other shapes (patterns), for example, any visual recognition marker such as a polka dot pattern, a lattice pattern, a mesh pattern, characters, symbols and the like may be used. These may be made to combine two or more different patterns.

TiN _x O _y (where 0.1 ≦ x ≦ 1.0, 0 ≦ y ≦ 1.9) is used as the color former. Here, in TiN _x O _y , when x is less than 0.1, there is a possibility that coloring does not occur well, and it is difficult to contain N exceeding 1.0. On the other hand, in TiN _x O _y , when y exceeds 1.9, good color tone cannot be obtained.

In TiN _x O _y , the O / N weight ratio is preferably about 0.2 to 8, more preferably about 0.5 to 7.

  For example, the color former may be in the form of particles, granules, pellets, scales, etc., but is preferably in the form of particles. Thereby, the color former can be mixed (dispersed) more uniformly in the material constituting the inner layer 31.

  When the particulate color former is used, the average particle diameter is not particularly limited, but is preferably, for example, 10 μm or less, more preferably 1 μm or less, and further about 0.1 to 1 μm. preferable. Thereby, the dispersion state of the color former in the inner layer 31 can be made more uniform.

  Further, the content of the color former in the inner layer 31 depends on the composition and characteristics (particularly the color tone) of the material constituting the inner layer 31. It is preferably about 0.01 to 10 wt%, more preferably about 0.01 to 3 wt%. If the content of the color former is too small, the whiteness of the color development portion (scale 9) may be lowered and may be unclear. On the other hand, if the content of the color former is increased beyond the upper limit, not only the effect is increased, but also mixing into the inner layer 31 (the material constituting the inner layer 31) becomes difficult. There is a case.

  The whiteness (L value) of the scale 9 (color developing portion) is preferably 60% or more, and more preferably 70% or more. If the whiteness is too small, good visibility of the scale 9 cannot be obtained.

  The color tone and color intensity of the scale 9 (color development part) can be adjusted by setting the content of the color former in the inner layer 31.

  Further, the color former in the inner layer 31 is preferably dispersed uniformly. For example, the color former may be unevenly distributed in the vicinity of the outer surface of the inner layer 31 (on the outermost layer 32 side). You may make it exist only in the part which forms 9), and its vicinity.

  Further, the composition of other constituent materials (mixing ratio of the contained components) may be uniform over the entire inner layer 31 or may be different at each part. For example, it may be one (gradient material) in which the blending ratio of the contained components sequentially changes in the thickness direction.

  In addition, a coloring agent is added (mixed) to the constituent material of the inner layer 31 as necessary, and the inner layer 31 has a black or dark color at least on its outer surface before being irradiated with laser light. It is preferable. Thereby, in the inner layer 31, the contrast between the scale 9 and other portions can be further increased.

  Examples of the colorant include nitroso dyes, nitro dyes, azo pigments, stilbene azo pigments, ketoimine dyes, triphenylmethane dyes, xanthene dyes, acridine dyes, quinoline dyes, methine dyes, thiazole dyes, indamine dyes, azine dyes, oxazines Dyes, thiazine dyes, sulfur dyes, aminoketone dyes, anthraquinone dyes, indigoid dyes, various dyes such as quinophthalone and anthrapyridone, azo series, disazo series, phthalocyanine series, quinacridone series, perylene series, perinone series, dioxazine series, anthraquinone series , Various organic pigments such as isoindolinone, lead sulfate, titanium yellow, iron oxide pigments, ultramarine, cobalt blue, chrome oxide green, spinel green, zinc yellow, chrome vermilion, chrome yellow Chrome green, cadmium yellow, cadmium red, carbon powder, zinc oxide, inorganic pigments, and the like, such as titanium oxide, can be used singly or in combination of two or more of them.

  When a colorant is added to the material constituting the inner layer 31, the addition amount (content) is not particularly limited, but is preferably 0.001 to 1 part by weight with respect to 100 parts by weight of the resin material. 0.01 to 0.1 part by weight is more preferable. If the added amount of the colorant is too small, depending on the type of the colorant, the effect due to the addition of the colorant may not be exhibited, whereas if the added amount of the colorant is too large, depending on the type of the resin material, etc. The inner layer 31 may be etched by laser light irradiation.

  Furthermore, in the constituent material of the inner layer 31, other additives may be added (mixed) as necessary.

  Examples of the additive include inorganic fillers, lubricants, plasticizers, various stabilizers (antioxidants, light stabilizers, antistatic agents, antiblocking agents), mold release agents, flame retardants, coupling agents, X Examples thereof include a line contrast agent.

  Examples of inorganic fillers include silicon dioxide, mica, kaolins, blast furnace slag, silica sand, siliceous clay, talc and other silicon compounds, calcium carbonate, alumina, glass fiber, wollastonite, glass flake, milled fiber, Examples include hardened zinc whiskers and potassium titanate whiskers.

  Examples of the lubricant include stialinic acid, behenic acid or esters and salts thereof, waxes such as carnauba wax and polyethylene wax, and various surfactants.

  Examples of the plasticizer include phthalic acid esters, phosphoric acid esters, and sepacic acid esters.

  An outermost layer 32 is provided so as to cover such an inner layer 31. The PMP contained in the material constituting the outermost layer 32 is hard and has high transparency. Thereby, the abrasion resistance excellent in the insertion part flexible tube 1 can be provided, preventing the visibility of the scale 9 formed in the outer surface of the inner layer 31 falling. And by providing this abrasion resistance, the protective function of the scale 9 (color-developing part) by the outermost layer 32 is exhibited, and the scale 9 is peeled, disappeared, fading, etc., and the outer layer 31 is caused by its formation. Deterioration in the vicinity of the surface scale 9 can be reliably prevented.

  Moreover, since PMP is excellent in chemical resistance, deterioration of the outer skin 3 (inner layer 31) can be prevented even if repeated cleaning, disinfection, sterilization, or the like is performed. Furthermore, since PMP is also excellent in heat resistance (melting point: 230 ° C. or higher), the electronic endoscope 10 can be adapted to high-pressure steam sterilization.

  Other relatively hard resins include polyester and polyurethane. However, in the outermost layer made mainly of materials containing these resins, the adhesion to the inner layer (SEBS, TPO, etc.) is reduced, Problems such as deterioration in chemical properties and heat resistance occur.

  The content of PMP in the material constituting the outermost layer 32 is preferably 50 wt% or more, and more preferably 70 wt% or more. Thereby, the outermost layer 32 exhibits more excellent wear resistance.

  In addition to the PMP, a material containing at least one of a thermoplastic elastomer and a polyolefin can be used as the material constituting the outermost layer 32. Thereby, the adhesiveness of the outermost layer 32 and the inner layer 31 can be improved. Moreover, since the softness | flexibility of the outermost layer 32 can be improved, the outer skin | 3rd will exhibit the especially outstanding softness | flexibility (flexibility) as a whole.

  Although it does not specifically limit as a thermoplastic elastomer, The thing which mainly has at least one of TPO or SEBS as mentioned above is preferable.

  On the other hand, as polyolefin, polyethylene, a polypropylene, a polypropylene-polyethylene copolymer etc. are mentioned, for example, Among these, it can use combining 1 type (s) or 2 or more types.

  Since these have excellent affinity (compatibility) with PMP, the outermost layer 32 having a uniform thickness can be formed, and the outermost layer 32 having higher adhesion to the inner layer 31 described above can be formed. can get.

  The amount of the thermoplastic elastomer, polyolefin or the total of these in the material constituting the outermost layer 32 is preferably 70 parts by weight or less, more preferably 50 parts by weight or less with respect to 100 parts by weight of PMP. . Thereby, the above-mentioned effect becomes more remarkable. On the other hand, if the blending amount exceeds the upper limit, the outermost layer 32 having sufficient wear resistance may not be obtained.

  It is preferable that the thickness of the outermost layer 32 and the thickness of the inner layer 31 satisfy the following relationship. That is, when the average thickness of the inner layer (first layer) 31 is a [mm] and the average thickness of the outermost layer (second layer) 32 is b [mm], b / a is 0.025. It is preferable to satisfy the relationship of ˜1, and it is more preferable to satisfy the relationship of 0.1 to 0.5. By satisfying such a relationship, the insertion portion flexible tube 1 has more appropriate flexibility and is more excellent in chemical resistance, heat resistance and wear resistance.

  The specific value of the average thickness of the outermost layer 32 varies slightly depending on the PMP content and the like, and is not particularly limited, but is preferably about 0.01 to 0.5 mm, more preferably about 0.03 to 0.3 mm. preferable. If the thickness of the outermost layer 32 is too thin, sufficient wear resistance may not be obtained. On the other hand, if the thickness of the outermost layer 32 is too thick, the flexibility of the insertion portion flexible tube 1 decreases. And free bending may be hindered.

  In addition, you may make it change the softness | flexibility (flexibility) of the insertion part flexible tube 1 by changing the thickness of the outermost layer 32 along a longitudinal direction.

  In addition, the average thickness of the entire outer skin 3 (excluding the protruding portion 4) can more reliably protect the core material 2 and the long members disposed therein from liquids such as body fluids, And, as long as the bending property of the insertion portion flexible tube 1 is not hindered, it is not particularly limited, but is preferably about 0.08 to 0.9 mm, more preferably about 0.1 to 0.8 mm, More preferably, it is about 0.3 to 0.5 mm.

  In addition, the thickness of the outer skin 3 may have a part which changes along a longitudinal direction, and may be substantially constant. By adopting the latter configuration, the operability when the insertion portion flexible tube 1 is inserted into the body cavity is further improved, and the burden on the patient is further reduced.

  As described above, the insertion portion flexible tube (endoscope flexible tube of the present invention) 1 of the present embodiment has an inner layer (first layer) in which the outer skin 3 is composed mainly of a material containing TPO or SEBS. Layer) 31 and an outermost layer (second layer) 32 composed mainly of a material containing PMP. For example, the outer skin 3 is composed of a material containing PMP as a main material. The outermost layer 32 is formed and the inner layer 31 composed mainly of a material containing TPO or SEBS is not provided, that is, the first layer of the present invention is not provided, and vice versa. If the two layers are not provided, the effect of the present invention cannot be obtained.

  For example, when the outer skin 3 does not have the first layer, sufficient flexibility cannot be obtained for the endoscope flexible tube. In addition, when the outer skin 3 does not have the second layer, sufficient wear resistance cannot be obtained for the endoscope flexible tube.

  Further, as in the present invention, a first layer composed of a material containing TPO or SEBS as a main material and a second layer composed of a material containing PMP as a main material are provided as separate layers. However, when one layer is formed as a mixture of these materials, sufficient resistance to abrasion cannot be obtained for the endoscope flexible tube.

  The aforementioned insertion portion flexible tube 1 (the endoscope flexible tube of the present invention) can be manufactured, for example, as follows.

  First, a spiral material 21 is produced by winding a belt-like material, and a node ring is joined to the tip. Next, the outer peripheral portion is covered with a mesh tube 22 braided with fine wires to obtain the core material 2.

  Next, by using an extrusion molding machine having a plurality of extrusion ports, the materials constituting the inner layer 31 and the outermost layer 32 are simultaneously extruded from the respective extrusion ports, and the laminate is coated on the core material 2 to form a laminate. The outer skin 3 having the structure is continuously manufactured.

  At this time, the thickness of each layer 31 and 32 can be adjusted by adjusting the discharge amount of the material which comprises each layer 31 and 32 from each extrusion port, and the drawing speed of the core material 2. FIG.

  Although the material temperature at the time of extrusion molding is not particularly limited, it is preferably about 170 to 260 ° C, more preferably about 190 to 250 ° C. When the material temperature at the time of extrusion molding is in such a temperature range, the outer skin material becomes excellent in the molding processability to the outer skin 3. For this reason, the uniformity of the thickness of the outer skin 3 is further improved. Moreover, material temperature may differ for every material which comprises each layer.

  Next, a laser beam is irradiated on a predetermined portion of the outer surface of the inner layer 31 through the outermost layer 32. Due to the energy of the laser light, the color former develops color, and the scale 9 (color development portion) is formed.

  Examples of the laser light to be irradiated include a He—Ne laser, a ruby laser, a semiconductor laser, an argon laser, an excimer laser, and a YAG laser.

  Among these, the YAG laser has a wavelength of 1.06 μm, and energy is not substantially absorbed by the resin material that is the main material of the inner layer 31. For this reason, it is preferable because the resin material does not easily burn or vaporize and is unlikely to be etched.

  A laser irradiation apparatus is not specifically limited, Any well-known thing may be used, for example, a scanning type, a dot type, and a mask type thing can be used. Further, the oscillation form of the laser beam may be either continuous oscillation or pulse oscillation.

Prior to irradiation with such laser light, the color of the outer surface of the inner layer 31 is black or dark due to TiN _x O _y (black). When the outer surface of the inner layer 31 is irradiated with laser light, TiN _x O _y (black) changes to TiO ₂ (white) due to a high-temperature oxidation reaction.

As a result, the color of the scale 9 (coloring portion) becomes white or light. Thus, by using TiN _x O _y as the color former, an extremely high brightness difference (contrast) can be obtained between the scale 9 (color development portion) and the other portions in the inner layer 31.

  According to the method for forming the scale 9, there is an advantage that the ink drying step required in the forming method by printing is unnecessary, and the scale 9 can be formed in a short time.

  Further, by forming the scale 9 after forming the outermost layer 32 as in this embodiment, it is possible to prevent the surface of the outer skin 3 from being uneven due to the volume change during color development of the color former. You can also. Thereby, it can prevent that the adhesiveness of the inner layer 31 and the outermost layer 32 falls.

  In the case of the present embodiment, the laser light passes through the outermost layer 32 and is irradiated on the outer surface of the inner layer 31. As the material constituting the outermost layer 32, a material having high transparency and capable of transmitting laser light used for forming the scale 9 is preferably selected.

  The optical characteristics (characteristics) of the outermost layer 32 are greatly affected by, for example, the thickness and the refractive index of the material constituting the outermost layer 32 in addition to the thickness of the outermost layer 32. When a material other than PMP is mixed in the material constituting 32, a material that can satisfy such conditions may be selected.

  Further, the outermost layer 32 is not limited to exhibiting such optical characteristics over its entire length, and it is sufficient that the outermost layer 32 satisfies at least a region where the scale 9 is formed.

  Further, the outermost layer 32 may be formed after the scale 9 is formed. Examples of the method for forming the outermost layer 32 include an injection molding method, a coating method (for example, spray coating, etc.), a method in which a heat-shrinkable tube (film) is attached, and heated to shrink.

  As mentioned above, although the flexible tube for endoscopes and endoscopes of this invention were demonstrated about embodiment of illustration, this invention is not limited to these.

  For example, the outer skin of the flexible tube for an endoscope of the present invention may be configured such that a part or all of the longitudinal direction is formed of a laminate of three or more layers. In this case, at least the outermost layer may be composed of a material containing polymethylpentene as a main material.

  In addition, when the endoscope flexible tube of the present invention is applied to the connecting portion flexible tube, that is, when it is not necessary to form the coloring portion, the outermost layer is colored with a colorant. Also good.

  The endoscope of the present invention is not limited to an electronic endoscope, but may be an optical endoscope (fiberscope). Furthermore, the endoscope is not limited to a medical endoscope but is used for industrial purposes. It may be a mirror.

  Next, specific examples of the present invention will be described.

1. Production of flexible tube for endoscope (Example 1)
First, a stainless steel strip having a width of 3.2 mm was wound to produce a spiral tube having an outer diameter of 9 mm and an inner diameter of 7 mm, and a node ring was joined to the tip. Next, this outer peripheral portion was covered with a braided mesh tube in which 10 fine stainless steel wires each having a diameter of 0.08 mm were arranged to obtain a core material having a length of 1.5 m.

On the other hand, a polyolefin-based thermoplastic elastomer (TPO) containing TiN _0.3 O _1.3 (coloring agent) and polymethylpentene are prepared, and the outer periphery of the core material is made of TPO by extrusion molding. An outer skin composed of a laminate having two layers of an inner layer formed and an outermost layer composed of polymethylpentene was formed.

  Formation of this laminated body was performed using the extrusion molding machine provided with the two extrusion ports. That is, the inner layer and the outermost layer were extruded at the same time, and the outer layer having a laminated structure was continuously formed by coating the laminated body on the core material. The temperature of the material at the time of extrusion molding was 220 ° C.

  The average thickness of the outer skin was 0.45 mm, the average thickness of the inner layer was 0.4 mm, and the average thickness of the outermost layer was 0.05 mm.

Further, TiN _0.3 O _1.3 was mixed with particles having an average particle diameter of 0.4 μm in a polyolefin-based thermoplastic elastomer so as to be 0.1 wt%.

  Next, a scale was formed by irradiation with a YAG laser. Thereby, an insertion portion flexible tube as shown in FIG. 2 was obtained.

  Moreover, as a result of measuring the whiteness (L value) of a scale part with the whiteness meter (Nippon Denshoku Industries Co., Ltd. make, NW-1), it was 60% or more.

(Examples 2 to 10 and Comparative Examples 1 to 4)
An insertion portion flexible tube was produced in the same manner as in Example 1 except that the constituent materials and thickness of each layer were changed as shown in Table 1.

2. Characteristic evaluation of flexible tube for endoscope [2.1] Chemical resistance test The chemical resistance test was performed on the flexible tube for endoscope produced in each example and each comparative example by the following method. .

  In the chemical resistance test, each endoscope flexible tube was cleaned and disinfected using a heating type cleaning machine (trade name: SME2000 (manufactured by BHT)).

  This cleaning / disinfection operation consists of I: a cleaning process using a cleaning liquid (nonionic surfactant) (about 10 minutes), II: a disinfection process using a disinfecting liquid (about 0.24 wt% glutaraldehyde aqueous solution) (about (10 minutes), III: washing step using warm water of about 60 ° C. (about 10 minutes), and IV: drying step with hot air (about 5 minutes).

  After this cleaning / disinfection operation was repeated 2000 times, the surface state of the endoscope flexible tube was observed and evaluated according to the following four-stage criteria.

A: No change in appearance.
○: Almost no gloss or yellowing is observed.
(Triangle | delta): Glossiness and yellowing are recognized slightly.
X: Glossiness and yellowing are clearly recognized.

[2.2] Heat resistance test A heat resistance test was performed on the flexible tube for an endoscope manufactured in each example and each comparative example by the following method.

  Three flexible tubes for endoscopes prepared in each example and each comparative example were prepared. Each flexible tube for an endoscope was subjected to autoclave sterilization at 135 ° C. for 15 minutes under 2.2 atm, and then a series of operations of rapidly cooling with ice water was repeated 20 times.

  In the heat resistance test, after a series of operations were repeated, the degree of deterioration of each endoscope flexible tube, particularly the degree of decrease in flexibility, was examined and evaluated according to the following four criteria.

A: Flexibility is almost unchanged.
○: Slightly reduced flexibility.
Δ: Flexibility decreases.
X: Cured state (with deterioration).

[2.3] Abrasion Resistance Test Abrasion resistance test based on SO9211-4 was performed on the flexible tube for an endoscope produced in each example and each comparative example. More specifically, an abrasion resistance test was performed under the following conditions.

  The surface of the outer skin of the endoscope flexible tube produced in each example and each comparative example was rubbed with a force of 50 cycles and 5 N using an abrasion tester. The friction head of the wear tester used cotton cheese cloth.

  In the abrasion resistance test, after performing a series of operations, the degree of scratches on the outer skin surface of each endoscope flexible tube was examined and evaluated according to the following four criteria.

A: Scratches are hardly observed.
○: Some scratches were observed.
Δ: Scratches were observed.
X: Many scratches were observed.

[2.4] Elasticity Test The elasticity test was performed on the flexible tube for endoscope manufactured in each Example and each Comparative Example by the following method.

  In the elasticity test, ten flexible tubes for each endoscope were prepared, and it was examined whether or not these bundles could be bent together.

  Each flexible tube for an endoscope was bundled and then subjected to a bending operation, and evaluated according to the following four criteria.

A: Rich in elasticity.
○: Resilient.
Δ: Slightly poor in elasticity
X: Almost no elasticity (cured state).

  These results are shown in Table 1 together with the constituent materials and average thickness of each layer, the average thickness of the entire outer skin, and the whiteness of the scale.

  As is apparent from Table 1, each of the endoscope flexible tubes (endoscopic flexible tube of the present invention) of each example has appropriate elasticity (flexibility), and Excellent chemical resistance, heat resistance and wear resistance.

  Moreover, the flexible tube for endoscopes of each example maintained a clear scale (whiteness of 60% or more) even after the abrasion resistance test.

  On the other hand, the flexible tubes for endoscopes of each comparative example were clearly inferior in at least one of the resilience, chemical resistance, heat resistance, and wear resistance.

  Among these, in the flexible tubes for endoscopes of Comparative Examples 1 and 2, the scale disappeared after the abrasion resistance test.

  Moreover, the flexible tube for endoscopes of Comparative Example 3 did not have flexibility and was difficult to apply to the endoscope.

  Moreover, in the flexible tube for endoscopes of Comparative Example 4, partial peeling was observed between the inner layer and the outermost layer after the heat resistance test.

1 is an overall view showing an embodiment when an endoscope of the present invention is applied to an electronic endoscope (electronic scope). It is an enlarged view which shows the longitudinal cross-section of the principal part of the insertion part flexible tube with which the electronic endoscope shown in FIG. 1 is provided.

Explanation of symbols

10 Electronic Endoscope 1 Insertion Section Flexible Tube (Flexible Tube for Endoscope of the Present Invention)
DESCRIPTION OF SYMBOLS 11 Flexible tube 12 Bending part 2 Core material 21 Spiral tube 22 Reticulated tube 23 Fine wire 24 Space 25 Space | interval 26 Gap 3 Outer skin 31 Inner layer (1st layer)
32 Outermost layer (second layer)
4 Protruding part 6 Operation part 61, 62 Operation knob 7 Connection part Flexible tube 8 Light source insertion part 81 Light source connector 82 Image signal connector 9 Scale

Claims (19)

A flexible tube for an endoscope having a tubular core material and an outer skin coated on the outer periphery of the core material,
The outer skin is composed of a laminate having at least two layers,
The laminate includes a first layer composed mainly of a material containing a polyolefin-based thermoplastic elastomer or a styrene-ethylene butylene-styrene block copolymer, and a material containing polymethylpentene. A second layer,
The flexible tube for an endoscope, wherein the second layer is an outermost layer.   The flexible tube for an endoscope according to claim 1, wherein the second layer is made of a material containing at least one of a thermoplastic elastomer and a polyolefin in addition to the polymethylpentene.   The thermoplastic elastomer contained in the material constituting the second layer is mainly composed of at least one of a polyolefin-based thermoplastic elastomer and a styrene-ethylene-butylene-styrene block copolymer. Flexible tube for endoscope.   The flexible tube for an endoscope according to any one of claims 1 to 3, wherein a content of the polymethylpentene in a material constituting the second layer is 50 wt% or more.   5. The content of the polyolefin-based thermoplastic elastomer or the styrene-ethylene-butylene-styrene block copolymer in the material constituting the first layer is 50 wt% or more. Flexible tube for endoscope. The first layer is mainly composed of a material containing both the polyolefin-based thermoplastic elastomer and the styrene-ethylene-butylene-styrene block copolymer,
The endoscope according to any one of claims 1 to 5, wherein a total content of the polyolefin-based thermoplastic elastomer and the styrene-ethylene-butylene-styrene block copolymer in the material is 50 wt% or more. Flexible tube.   The relation that b / a is 0.025 to 1 is satisfied, where the average thickness of the first layer is a [mm] and the average thickness of the second layer is b [mm]. The flexible tube for endoscopes according to any one of 1 to 6.   The flexible tube for an endoscope according to any one of claims 1 to 7, wherein an average thickness of the second layer is 0.01 to 0.5 mm.   The flexible tube for an endoscope according to any one of claims 1 to 8, wherein an average thickness of the outer skin is 0.08 to 0.9 mm.   The flexible tube for an endoscope according to any one of claims 1 to 9, wherein the first layer and the second layer are adjacent to each other. The second layer has optical transparency,
The first layer is TiN _x O _y (provided that 0.1 ≦ x ≦ 1.0, 0 ≦ y ≦ 1) as a color former that develops color by irradiation with laser light at least in the vicinity of the outer surface. The flexible tube for an endoscope according to claim 10, wherein a color-developing part formed by color development of the color former is formed.   The flexible tube for an endoscope according to claim 11, wherein the color former is in a particulate form.   The flexible tube for an endoscope according to claim 12, wherein the particulate color former has an average particle size of 10 μm or less. The first layer has a color former-containing region containing the color former,
The flexible tube for an endoscope according to any one of claims 11 to 13, wherein a content of the color former in the color former-containing region is 0.01 to 10 wt%.   The flexible tube for an endoscope according to any one of claims 11 to 14, wherein a color of the outer surface of the first layer before irradiation with laser light is black or dark.   The flexible tube for an endoscope according to any one of claims 11 to 15, wherein a color of the color developing portion is white or light.   The flexible tube for an endoscope according to claim 16, wherein the whiteness (L value) of the coloring portion is 60% or more.   The flexible tube for an endoscope according to any one of claims 11 to 17, wherein the coloring portion is a scale indicating an insertion depth of the flexible tube for an endoscope.   An endoscope comprising the flexible tube for an endoscope according to any one of claims 1 to 18.

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