JP2002095628A - Flexible tube for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube for endoscope which is excellent in chemical resistance and durability. SOLUTION: The flexible tube 1 of the insertion section is composed of a core member 2 having a hollow section and an outer sheath 3 coating a periphery of the core member 2. The core member 2 is composed of a spiral tube 21 formed by helically winding a belt-like member and a network tube 22 formed by meshwork of fine wires 23. A coated layer 231 made up of a material containing polyvinylidene fluoride is formed around at least a piece of fine wire 23. At least a part of the sheath 3 facing with the core member 2 is made up of the material containing polyvinylidene fluoride. A melting point of the material that composes the coated layer 231 preferably has a higher value than a melting point of the material that composes the sheath 3. Preferably an average thickness of the coated layer 231 is 0.01 to 0.1 mm and an average thickness of the sheath 3 is 0.01 to 1.5 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube for an endoscope.

[0002]

2. Description of the Related Art A flexible tube for an endoscope has a structure in which a tubular core material in which the outer periphery of a spiral tube is covered with a mesh tube is covered with a sheath made of synthetic resin or the like.

In endoscopy, a flexible tube for an endoscope is inserted while being bent deep into a body cavity such as the stomach, duodenum, small intestine or large intestine. For this reason, the flexible tube for an endoscope, by covering the outer peripheral portion with an outer skin, improves the ease of insertion operation (flexibility), reduces the burden on the patient, and reduces the fluid such as body fluids. It prevents entry into the endoscope. Conventionally, an elastic material (elastomer) such as polyurethane has been generally used as a constituent material of an outer skin of the flexible tube for an endoscope.

By the way, since the endoscope is used repeatedly, it must be cleaned and disinfected each time. However, the conventional materials are inferior in chemical resistance. For this reason, when the washing and disinfection are repeatedly performed on the endoscope, the outer skin is deteriorated, the adhesion between the core material and the outer skin is reduced, and when the deterioration is particularly remarkable, the outer skin is separated from the core material. There was something. As a result, the elasticity of the flexible tube for an endoscope is reduced, and there has been a problem that it is difficult to insert the flexible tube into a lumen.
That is, there is a problem in durability of the flexible tube for an endoscope.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flexible tube for an endoscope having excellent chemical resistance and durability.

[0006]

This and other objects are achieved by the present invention which is defined below as (1) to (12).

(1) A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on the outer periphery of the core material, wherein at least a portion of the outer skin facing the core material is provided. ,
A flexible tube for an endoscope, comprising a material containing a fluorine-based resin having a melting point of 300 ° C. or lower.

Thus, a flexible tube for an endoscope having excellent chemical resistance and durability can be provided.

(2) A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on the outer periphery of the core material, wherein the core material is formed by spirally winding a strip material. Having a spiral tube formed by turning, a braid formed by braiding a fine wire,
A flexible tube for an endoscope, wherein a coating layer made of a material containing a fluorine-based resin having a melting point of 300 ° C. or less is formed on at least one of the thin wires.

As a result, when a fluorine-based resin is used as the material of the outer cover, the adhesion to the resin is improved, and excellent durability is obtained.

(3) A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on an outer periphery of the core material, wherein the core material is formed by winding a strip material in a spiral shape. Having a spiral tube formed by turning, a braid formed by braiding a fine wire,
The portion of the outer skin facing the braid has a melting point of 300.
A coating layer made of a second material containing a fluorine-based resin having a melting point of 300 ° C. or less is formed on at least one of the fine wires. A flexible tube for an endoscope.

Thus, a flexible tube for an endoscope having excellent chemical resistance and durability can be provided.

(4) The flexible tube for an endoscope according to the above (3), wherein the second material contains at least 25 wt% of the first material.

Thus, the adhesion between the outer cover and the core material is further improved, and the chemical resistance and durability of the flexible tube for an endoscope are further improved.

(5) The flexible tube for an endoscope according to the above (3) or (4), wherein a melting point of the first material is lower than a melting point of the second material.

Thus, the adhesion between the outer cover and the core material is further improved, and the chemical resistance and durability of the flexible tube for an endoscope are further improved.

(6) The average thickness of the coating layer is 0.0
The flexible tube for an endoscope according to any one of the above (2) to (5), which is 1 to 0.1 mm. This further improves the chemical resistance and durability of the flexible tube for an endoscope.

(7) The flexible tube for an endoscope according to any one of the above (1) to (6), wherein the outer cover is formed by extrusion molding.

As a result, the adhesion between the outer cover and the core material is further improved, and the chemical resistance and durability of the flexible tube for an endoscope are further improved.

(8) The melting point of the fluororesin is 26
The flexible tube for an endoscope according to any one of the above (1) to (7), which has a temperature of 2 ° C. or lower.

Thus, the productivity of the flexible tube for an endoscope is improved, and the chemical resistance and durability of the flexible tube for an endoscope are further improved.

(9) The flexible tube for an endoscope according to the above (8), wherein the fluorine-based resin is polyvinylidene fluoride or a material mainly containing polyvinylidene fluoride.

Thus, the productivity of the flexible tube for an endoscope is improved, and the chemical resistance and durability of the flexible tube for an endoscope are further improved.

(10) The flexible tube for an endoscope according to any one of the above (1) to (9), wherein the outer skin has a laminated portion in which a plurality of layers are laminated.

Thus, at least one of the flexibility, chemical resistance, durability and operability of the flexible tube for an endoscope is further improved.

(11) The innermost layer of the outer skin is 300 ° C.
The endoscope according to the above (10), wherein the portion other than the innermost layer is made of a material containing a polyurethane-based resin or a polyurethane-based elastomer. Flexible tube. This allows
The flexibility of the flexible tube for an endoscope is improved.

(12) The average thickness of the outer skin is 0.0
The flexible tube for an endoscope according to any one of (1) to (11), which is 1 to 1.5 mm. This further improves the chemical resistance and durability of the flexible tube for an endoscope.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a flexible tube for an endoscope according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an overall view showing an electronic endoscope (electronic scope) having an insertion portion flexible tube to which the flexible tube for an endoscope of the present invention is applied. Hereinafter, in FIG. 1, the upper side will be described as a “base end” and the lower side as a “distal end”.

As shown in FIG. 1, the electronic endoscope 10 is provided at a flexible (flexible) long insertion tube 1 having a long length and a distal end portion of the insertion tube 1. Operating section 6 provided at the proximal end of insertion section flexible tube 1, which is gripped by an operator to operate electronic endoscope 10, and connection section connected to operating section 6. The flexible tube 7 includes a flexible tube 7 and a light source insertion portion 8 provided on a distal end side of the flexible tube 7.

The flexible insertion tube 1 is used by being inserted into a lumen of a living body. The operation unit 6 is provided with operation knobs 61 and 62 on its side surface. These operation knobs 61 and 6
When the user operates the wire 2, the wire (not shown) provided in the insertion portion flexible tube 1 is pulled, and the bending portion 5 is bent in four directions, and the direction can be changed.

An image pickup device (CCD) (not shown) for picking up an image of a subject at an observation site is provided at the distal end of the bending section 5, and an image signal connector 82 is provided at the distal end of the light source insertion section 8. Have been. The image signal connector 82 is connected to a light source device, and the light source device is further connected to a monitor device (not shown) via a cable.

A light source connector 81 is provided at the end of the light source insertion portion 8, and the light source connector 81 is connected to a light source device (not shown). The light emitted from the light source device is supplied to the light source connector 81 and the light source insertion portion 8.
Through a light guide (not shown) of an optical fiber bundle continuously disposed in the flexible tube 7, the connecting portion 7, the operating portion 6, the insertion portion flexible tube 1 and the bending portion 5. The observation part is irradiated from the tip of No. 5 and illuminated.

The reflected light (subject image) from the observation site illuminated by the illumination light is picked up by an image pickup device. The image sensor outputs an image signal corresponding to the captured subject image.

This image signal is continuously arranged in the bending portion 5, the insertion portion flexible tube 1, the operation portion 6 and the connection portion flexible tube 7, and the image element and the image signal connector 82 Is transmitted to the light source insertion unit 8 via an image signal cable (not shown) for connecting.

Then, predetermined processing (for example, signal processing, image processing, and the like) is performed in the light source insertion unit 8 and the light source device, and thereafter, input to the monitor device. The monitor device displays an image (electronic image) captured by the image sensor, that is, a moving image of the endoscope monitor image.

The overall configuration of the electronic endoscope 10 having the flexible insertion tube 1 to which the flexible tube for an endoscope of the present invention is applied has been described above. Needless to say, the present invention can be applied to a flexible tube of an optical endoscope.

FIG. 2 is an enlarged semi-longitudinal sectional view showing a first embodiment of an insertion portion flexible tube to which the flexible tube for an endoscope of the present invention is applied.

The flexible tube 1 has a core member 2 and an outer shell 3 covering the outer periphery thereof. In addition, the insertion portion flexible tube 1
Is provided with a space 24 in which, for example, a built-in component such as an optical fiber, an electric cable, a cable or a tube (omitted in the drawing) can be arranged and inserted.

The core member 2 is composed of a spiral tube 21 and a braided tube (braided body) 22 that covers the outer periphery of the spiral tube 21, and is formed as a tube-like long object as a whole. The core material 2 has an effect of reinforcing the insertion portion flexible tube 1. In particular, by combining the spiral tube 21 and the mesh tube 22,
The insertion portion flexible tube 1 can ensure sufficient mechanical strength.

The spiral tube 21 is formed by spirally winding a band-shaped material with a uniform diameter at an interval 25. As a material forming the belt-like material, for example, an iron-based alloy such as stainless steel, a copper-based alloy, or the like is preferably used.

FIG. 3 is an enlarged sectional view of a mesh tube used for manufacturing the flexible tube for an endoscope of the present invention. FIG. 4 is an enlarged cross-sectional view showing a state in the vicinity of a mesh tube of the flexible tube of the insertion portion shown in FIG.

The mesh tube 22 is formed by braiding a plurality of thin wires 23 made of metal or non-metal. Examples of the metal material forming the fine wire 23 include an iron-based alloy such as stainless steel and a copper-based alloy. Also,
Examples of the nonmetallic material include a high melting point resin, carbon fiber, glass fiber and the like.

As shown in FIG. 3, a coating layer 231 is formed on at least one of the fine wires 23.

By providing such a coating layer 231, as shown in FIG. 4, the coating layer 231 and the outer skin 3 can be strongly adhered (compatibilized). Thereby, the adhesiveness (coupling force) between the mesh tube 22 and the outer cover 3 is improved, and as a result, the elasticity and durability of the insertion portion flexible tube 1 are improved.

The coating layer 231 is preferably made of a material containing a fluorine resin having a melting point of 300 ° C. or less.
Such a material has excellent adhesiveness to the fine wire 23 and excellent adhesiveness (compatibility) with the outer cover 3 described later. Thereby, the adhesion between the mesh tube 22 and the outer cover 3 is improved, and as a result, the durability of the flexible tube 1 is improved.
In addition, since the melting point is relatively low, the coating
The molding temperature at the time of coating the outer periphery of the resin can be relatively low. Thereby, the moldability of the coating layer 231 is improved,
As a result, the productivity of the flexible tube 1 is improved.

Examples of the fluorine resin having a melting point of 300 ° C. or less include tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), and polychlorotrifluoroethylene (PCTFE). ), Chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF)
Or a polymer alloy (for example, a polymer blend or a copolymer) containing two or more of these.

Among them, those containing a fluorine-based resin having a melting point of 262 ° C. or less are particularly preferable. Thereby, the above-mentioned effect becomes more remarkable. Melting point 26
As the fluororesin having a temperature of 2 ° C. or lower, for example, a tetrafluoroethylene-hexafluoropropylene copolymer (F
EP), polychlorotrifluoroethylene (PCTF
E), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF),
Polyvinyl fluoride (PVF) and the like.

Further, those containing a fluorine-based resin having a melting point of 235 ° C. or less are preferable. As a result, the above-described effects become more remarkable. Examples of the fluorine-based resin having a melting point of 235 ° C. or less include polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and the like. Or a polymer alloy (for example, a polymer blend or a copolymer) containing two or more of these.

Among them, polyvinylidene fluoride (PV
DF) or those mainly comprising it (containing 50 wt% or more) are most preferred. Since PVDF has a particularly low melting point among the above-mentioned fluorine-based resins, formation of the coating layer 231 at a low temperature can be performed easily and reliably. Further, PVDF is particularly excellent in adhesion to the fine wire 23 and adhesion (compatibility) to the outer cover 3.

The covering layer 231 is preferably made of a material containing a constituent material of the outer cover 3 described later (at least a constituent material of a portion facing the net 22). Here, the constituent material refers to a main material, and does not include additives and the like. As described above, by using a material containing the constituent material (first material) of the outer cover 3 as the constituent material (second material) of the coating layer 231, the adhesion (compatibility) between the cover layer 231 and the outer cover 3 can be improved. ) Can be further improved. Thereby, the adhesion (coupling force) between the mesh tube 22 and the outer cover 3 is further improved. As a result, the elasticity and durability of the insertion portion flexible tube 1 are further improved. Coating layer 23
The ratio of the constituent material of the outer skin 3 contained in the constituent material of 1 is
It is preferably at least 25 wt%, more preferably at least 40 wt%.

The melting point of the constituent material of the coating layer 231 is T
Assuming that ₁ (° C.) and the melting point of the constituent material of the outer cover 3 is T ₂ (° C.), it is preferable that the relationship of T ₁ ≧ T ₂ holds. In particular, the difference (T ₁ −T ₂ ) between the melting point T ₁ of the constituent material of the coating layer 231 and the melting point T ₂ of the constituent material of the outer cover 3 is preferably 0 to 140 ° C., and is 0 to 80 ° C. More preferably, there is.

The coating of the outer cover is usually performed by extruding the constituent material of the outer cover on the outer periphery of the core material (outer periphery of the mesh tube 22), and T ₁ and T ₂ satisfy the above-mentioned relationship. Thus, the coating of the outer skin 3 by such extrusion molding can be performed in a state where the constituent material of the outer skin 3 is sufficiently melted and the coating layer 231 is in close contact with the fine wire 23. Thereby, the adhesion between the outer skin 3 and the coating layer 231 and the coating layer 2
The adhesion between the thin wire 31 and the fine wire 23 is particularly excellent.
Thereby, the adhesion between the outer cover 3 and the braided tube 22 is further improved, and as a result, the durability of the flexible tube 1 is particularly excellent.

The weight average molecular weight (Mw) of the constituent material of the coating layer 231 is not particularly limited.
８800000, preferably 15,000 to 1
More preferably, it is 00000.

The constituent material of the coating layer 231 may be a polymer alloy (polymer blend, copolymer, or the like) containing another polymer material in addition to the above-mentioned fluorine-based resin.

Further, the constituent material of the coating layer 231 may optionally contain additives.

Examples of the additives include plasticizers, inorganic fillers, pigments, various stabilizers (antioxidants, light stabilizers, antistatic agents, antiblocking agents, lubricants), X-ray contrast agents, and the like. .

The average thickness of the coating layer 231 is not particularly limited, but is preferably 0.01 to 0.1 mm.
More preferably, it is 0.02 to 0.07 mm. If the average thickness of the coating layer 231 is less than the lower limit, the effects of the present invention may not be sufficiently obtained. On the other hand, when the average thickness of the coating layer 231 exceeds the upper limit, irregularities may be generated on the surface of the insertion portion flexible tube 1 and the appearance may be deteriorated.

A gap 26 is formed on the outer periphery of the braided 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 a hole communicating with the space 24 at a position overlapping the interval 25 of the spiral tube 21, and forms a large number of holes and concave portions on the outer periphery of the core material 2. are doing. The outer periphery of the core material 2 is covered with a flexible outer skin 3.

A number of projections (anchors) 31 protruding toward the inner peripheral side are formed on the inner peripheral surface of the outer cover 3 continuously from the outer cover 3. Each protruding portion 31 enters each of a large number of holes and concave portions formed on the outer periphery of the core material 2. The tip of the protrusion 31 that has entered the recess is formed until it reaches the outer periphery of the spiral tube 21. The protruding portion 31 that has entered the hole is formed longer, and its tip enters the space 25 of the spiral tube 21.

Since the projections 31 are formed in this manner, the projections 31 engage with a large number of holes and recesses formed on the outer periphery of the core member 2, so that an anchor effect is produced.
The outer cover 3 is securely fixed to the core 2. Therefore, even when the flexible tube 1 is bent, the outer skin 3 is kept in close contact with the core material 2 and expands and contracts sufficiently in accordance with the bending of the core material 2. The restoring force of the outer skin 3 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. Therefore, with such a configuration, the flexible insertion section 1 is excellent in elasticity.

Further, by forming the protruding portion 31,
Since the bonding force between the outer cover 3 and the reticulated tube 22 is strong, the outer cover 3 is less likely to peel off from the reticulated tube 22 even when used repeatedly. Therefore, the flexible tube 1 has excellent elasticity even after repeated use, and is excellent in durability.

The outer cover 3 is preferably made of a material containing a fluorine resin having a melting point of 300 ° C. or less. Such a material has excellent chemical resistance and the core material 2
Excellent adhesion to In particular, by providing the above-mentioned coating layer 231, this effect becomes more remarkable. For this reason, the adhesiveness between the core material 2 and the outer cover 3 is improved, and the chemical resistance and durability of the insertion portion flexible tube 1 are excellent.

Further, since such a material has a lower melting point than a high melting point fluororesin such as Teflon (registered trademark), the following effects can be obtained. -The molding temperature at the time of coating the outer skin 3 on the outer periphery of the core material 3 can be made relatively low. Thereby, the moldability of the coating layer 231 is improved, and as a result, the productivity of the flexible tube 1 is improved. -Even if the molding temperature of the outer cover 3 is relatively low, the viscosity of the constituent material of the outer cover 3 is sufficiently reduced, and the fluidity of the material is improved. For this reason, it becomes easy for the outer skin 3 to enter the gap between the core members 2, and the above-described anchor effect becomes more remarkable. -Since the fluidity of the skin material in the molding machine is improved, the composition of the obtained skin 3 is uniform throughout.

By these effects (synergistic effect), the flexible tube 1 of the insertion portion has particularly excellent chemical resistance and durability.

Examples of the fluorine-based resin having a melting point of 300 ° C. or less include tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-ethylene copolymer (ETFE), and polychlorotrifluoroethylene (PCTFE). ), Chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF)
Or a polymer alloy (for example, a polymer blend or a copolymer) containing two or more of these.

Among these, those containing a fluorine-based resin having a melting point of 262 ° C. or less are particularly preferable. Thereby, the above-mentioned effect becomes more remarkable. Melting point 26
As the fluororesin having a temperature of 2 ° C. or lower, for example, a tetrafluoroethylene-hexafluoropropylene copolymer (F
EP), polychlorotrifluoroethylene (PCTF
E), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF),
Polyvinyl fluoride (PVF) and the like.

Further, those containing a fluorine-based resin having a melting point of 235 ° C. or less are preferable. As a result, the above-described effects become more remarkable. Examples of the fluorine-based resin having a melting point of 235 ° C. or less include polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene-ethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and the like. Or a polymer alloy (for example, a polymer blend or a copolymer) containing two or more of these.

Among them, polyvinylidene fluoride (PV
DF) or those mainly comprising it (containing 50 wt% or more) are most preferred. Since PVDF has a particularly low melting point among the above-mentioned fluororesins, it is possible to easily and reliably form the outer cover 3 at a low temperature. The PVDF is made of the core material 2 (particularly, the coating layer 231).
It is also particularly excellent in adhesiveness with the resin.

The weight average molecular weight (Mw) of the constituent material constituting the outer cover 3 is not particularly limited.
0 to 80,000,000, preferably 15,000
More preferably, it is で 100,000.

The constituent material of the outer cover 3 may be a polymer alloy (polymer blend, copolymer, or the like) containing another polymer material in addition to the above-mentioned fluororesin.

Further, the constituent material of the outer cover 3 may optionally contain an additive, if necessary.

Examples of the additives include plasticizers, inorganic fillers, pigments, various stabilizers (antioxidants, light stabilizers, antistatic agents, antiblocking agents, lubricants), X-ray contrast agents, and the like. .

The constituent materials of the outer cover 3 have been described above. The composition of the constituent materials of the outer cover 3 (mixing ratio of the components) is as follows.
It may be uniform over the entire outer skin 3,
Each part may be different. For example, a material (gradient material) in which the compounding ratio of the contained components changes sequentially in the thickness direction may be used.

The thickness of the outer cover 3 (excluding the protrusion 4)
Is preferably substantially constant along the longitudinal direction. Thereby, the operability when inserting the flexible tube 1 into the body cavity is further improved, and the burden on the patient is further reduced.

The average thickness of the outer cover 3 (excluding the protruding portion 31) can protect the core material 2 and instruments and the like inserted therein from liquids such as bodily fluids, and have a flexible insertion portion. There is no particular limitation as long as the curveability of the tube 1 is not hindered. Usually, it is preferably about 0.01 to 1.5 mm, and 0.1 to 1.5 mm.
About 1.0 mm is more preferable.

The flexible tube 1 is manufactured, for example, as follows. First, a spiral tube 21 and a mesh tube 22 are prepared.

The spiral tube 21 can be obtained, for example, by preparing a plate and turning it.

The mesh tube 22 can be obtained by braiding the fine wire 23. Prior to braiding the thin wire 23, a coating layer 231 is formed on at least one of the wires.

The constituent material of the coating layer 231 is obtained by melting or softening the above-mentioned components, mixing and kneading. To melt or soften each component, mix and knead,
For example, kneaders such as kneaders, kneader ruders, rolls, and continuous kneading extruders can be used. When each component is kneaded using such a kneading machine, the material is a material in which each component is uniformly mixed.

The kneading temperature is not particularly limited.
For example, the temperature is preferably about 160 to 340 ° C.
The temperature is more preferably about 70 to 320 ° C,
More preferably, the temperature is about 300 ° C. When each component is kneaded in such a temperature range, the uniformity of each component in the material is improved.

The coating layer 231 can be formed by coating the kneaded material on the fine wire 23 by, for example, extrusion molding, molding, or the like.

The helical tube 21 and the mesh tube 22 thus obtained are assembled to produce the core material 2.

Thereafter, the outer tube 3 is coated on the outer periphery of the core material 2 to manufacture the flexible tube 1 at the insertion portion.

The material of the outer cover 3 is obtained by melting or softening the above-mentioned components, mixing and kneading. For melting or softening, mixing and kneading the components, for example, a kneader, a kneader-ruder, a roll, a kneading machine such as a continuous kneading extruder and the like can be used. When each component is kneaded using such a kneading machine, the material is a material in which each component is uniformly mixed.

The kneading temperature is not particularly limited.
For example, the temperature is preferably about 160 to 340 ° C.
The temperature is more preferably about 70 to 320 ° C,
More preferably, the temperature is about 300 ° C. When each component is kneaded in such a temperature range, the uniformity of each component in the material is improved.

Then, the flexible tube 1 can be manufactured continuously by coating the core material 2 by extrusion molding on the core material 2 thus kneaded.

It is preferable that the temperature t (° C.) of the outer shell material at the time of extrusion molding satisfies the following formula (I) with the melting point T ₂ (° C.) of the constituent material of the outer shell 3.

T ₂ ≦ t ≦ T ₂ +60 (I) Further, instead of the formula (I), it is more preferable that the formula (II) is satisfied, and it is more preferable that the formula (III) is satisfied.

T ₂ + 5 ≦ t ≦ T ₂ +55 (II) T ₂ + 10 ≦ t ≦ T ₂ +50 (III) When the temperature t (° C.) of the outer cover material at the time of extrusion molding is less than the lower limit value. If there is, sufficient fluidity of the outer shell material cannot be obtained, and the moldability of the outer shell 3 decreases, and as a result, the outer shell 3 and the coating layer 23
In some cases, the adhesion to No. 1 may decrease. On the other hand, when the temperature t (° C.) of the shell material at the time of extrusion exceeds the upper limit, the coating layer 231 melts at the time of extrusion, and the thin wire 23 and the coating layer 231 are melted.
Adhesion may be reduced.

FIG. 5 is an enlarged semi-longitudinal sectional view showing a second embodiment of the flexible tube at the insertion portion to which the flexible tube for an endoscope of the present invention is applied. Hereinafter, the flexible tube 1 for the insertion portion shown in FIG. 5 will be described focusing on the differences from the first embodiment, and the description of the same matters will be omitted.

In the flexible tube 1 of the insertion portion according to the second embodiment, the outer skin 3 is constituted by a laminate having an inner layer 32 and an outer layer 33.

[0093] The outer skin 3 is made of an inner layer 3 as described below.
2 and the outer layer 33 are made of materials having different physical characteristics or chemical characteristics (these are collectively referred to as “physical properties”). Physical properties include, for example, rigidity (flexibility), hardness, elongation, tensile strength, shear strength, flexural modulus, flexural strength, and the like. Chemical properties include
For example, chemical resistance, weather resistance and the like can be mentioned. Note that these are merely examples, and the present invention is not limited to these.

The inner layer 32 is formed on the inner peripheral side of the outer cover 3 and is in contact with the core material 2 (coating layer 231). Therefore, the inner layer 32 is preferably made of the same material as the constituent material of the outer cover 3 of the first embodiment described above.

The average thickness of the inner layer 32 (excluding the projection 4) is not particularly limited, but is usually 0.01 to
It is preferably about 0.8 mm, more preferably about 0.03 to 0.4 mm.

The outer layer 33 is formed on the outer peripheral surface of the inner layer 32. The outer layer 33 is preferably a layer having excellent flexibility (elasticity). Thereby, the insertion portion flexible tube 1
The burden on the patient when inserting into the body cavity is reduced.

The constituent material of the outer layer 33 is not particularly limited. For example, polyolefin such as polyvinyl chloride, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyamide, polyethylene terephthalate (PE)
T), polyesters such as polybutylene terephthalate,
Various types of fluororesins such as polyurethane, polystyrene resin, polytetrafluoroethylene (PTFE), and tetrafluoroethylene-perfluoroalkylvinyl ether copolymer (PFA) (however, a fluororesin having a melting point of more than 300 ° C), and polyimide Flexible resins, polyurethane-based elastomers, polyester-based elastomers, polyolefin-based elastomers, polyamide-based elastomers, polystyrene-based elastomers, fluorine-based elastomers, various elastomers such as silicone rubber, latex rubber, etc., or blends mainly containing these , A copolymer (including a block copolymer), a polymer alloy, and the like, and one or more of these can be used in combination.

Among them, polyurethane elastomers, polyolefin elastomers, and polyester elastomers having low hardness are particularly preferred because of their excellent elasticity.

The average thickness of the outer layer 33 is not particularly limited, but is usually preferably about 0.01 to 0.8 mm.
It is more preferably about 0.02 to 0.4 mm.

The outer cover 3 may have a laminated portion in which such a plurality of layers are laminated over its entire length, or may have at least a part thereof.

As described above, by forming the outer cover 3 as a laminate of a plurality of layers, the advantages of the material constituting each layer can be obtained. In the present embodiment, since the outer skin 3 is composed of the outer layer 33 having excellent flexibility and the inner layer 32 having excellent chemical resistance and excellent adhesion to the core material 2, the entire outer skin 3 is formed. Have these characteristics.

Such a flexible insertion portion tube can be manufactured in the same manner as in the first embodiment. Particularly, when an extruder having a plurality of extrusion ports is used, the material of the inner layer and the outer layer is simultaneously extruded from each of the extrusion ports, and the laminated body is coated on a core material, so that the outer skin having a laminated structure is continuously formed. It is also possible to manufacture it.

When the laminated body is coated on the core material in this manner, the constituent material temperature of the inner layer 32 at the time of extrusion molding is substantially the same as the outer skin material temperature t at the time of extrusion molding of the first embodiment. Is preferred. Further, the temperature of the constituent material of the outer layer 33 during extrusion molding is slightly different depending on the type of the constituent material, but is preferably about 150 to 320 ° C, and more preferably about 160 to 300 ° C. By setting the material temperature during extrusion molding to a value within such a range, the adhesion between the outer cover 3 and the coating layer 231 is further improved, and the adhesion between the inner layer 32 and the outer layer 33 is also improved.

However, when the constituent material of the outer layer 33 is mainly a rubber-based material such as silicone rubber or the like, the plasticity of the constituent material of the outer layer 33 may be reduced due to heat generated during kneading. Therefore, in such a case, the kneading is preferably performed in a state where the material temperature is set to about 10 to 70 ° C.

The thickness of each layer can also be adjusted by adjusting the discharge amount of the constituent material of each layer from each extrusion port and the pulling speed of the core material.

Although the flexible tube for an endoscope of the present invention has been described above, the present invention is not limited to these.

For example, in the second embodiment, the outer skin 3
Is composed of two layers, an inner layer 32 and an outer layer 33,
It may be composed of three or more layers.

As a method of manufacturing a flexible tube for an endoscope, first, the outer cover 3 is formed as a continuous long object,
A method is also possible in which the core material 2 is inserted into the inner cavity of the outer skin 3 and then tightly fixed by heating or the like.

The flexible tube for an endoscope of the present invention can be applied to, for example, a flexible tube at a connection portion connected to a light source device.

[0110]

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

[0111] 1. Example 1 Fabrication of Flexible Tube for Endoscope (Example 1) First, a 3 mm-wide stainless steel band was wound around a spiral tube 2 having an outer diameter of 9.9 mm and an inner diameter of 9.6 mm.
1 was produced.

Next, a thin stainless steel wire having a diameter of 0.1 mm was prepared. Among these, a coating layer was formed on some of the fine wires over the entire length of the fine wires. Polyvinylidene fluoride (product name: Neoflon VDF, manufactured by Daikin Industries, Ltd., melting point: 174 ° C.) was used as a constituent material of the coating layer. The formation of the coating layer was carried out by extrusion at a material temperature of 210 ° C. The average thickness of the coating layer was 0.03 mm.

A set of three wires consisting of one thin wire having a coating layer formed thereon and two thin wires having no coating layer formed thereon,
A braided tube was produced by braiding them.

A core material was prepared by coating a spiral tube with the mesh tube thus obtained.

Next, on the outer periphery of the core material, polyvinylidene fluoride (product name: NEOFLON VD) was formed by extrusion molding.
F, manufactured by Daikin Industries, Ltd., melting point: 174 ° C.), and a flexible tube for an endoscope having a length of 1.5 m was produced. In addition, the skin material temperature (t) at the time of extrusion molding is 1
90 ° C. The average thickness of the outer skin of the obtained flexible tube for an endoscope was 0.5 mm.

(Example 2) A flexible tube for an endoscope was produced in the same manner as in Example 1, except that the outer skin to be coated on the core material was a laminate comprising an inner layer and an outer layer. The formation of the laminate was performed using an extruder equipped with two extrusion ports.
That is, the inner layer and the outer layer were simultaneously extruded, and the laminated body was coated on a core material to continuously produce an outer skin having a laminated structure. As the constituent materials of the inner layer and the outer layer, polyvinylidene fluoride (product name: NEOFLON VDF,
A polyurethane elastomer (product name: T8180, manufactured by Dainippon Ink and Chemicals, Ltd., melting point: 170 ° C.) was used.

Incidentally, the temperature of the constituent material of the inner layer during extrusion molding,
The constituent material temperatures of the outer layers were all 200 ° C. The average thickness of the inner layer and the outer layer of the obtained flexible tube for an endoscope was 0.2 mm and 0.25 mm, respectively.

Example 3 A kneaded product of polyvinylidene fluoride (60 wt%) and polychlorotrifluoroethylene (40 wt%) was used as a constituent material of the coating layer (melting point: 1).
A flexible tube for an endoscope was produced in the same manner as in Example 2 except that 90 ° C.) was used. The material temperature during the formation of the coating layer was 210 ° C.

(Example 4) A flexible tube for an endoscope was produced in the same manner as in Example 2 except that polyvinyl fluoride (melting point: 203 ° C) was used as a constituent material of the coating layer. In addition,
The material temperature at the time of forming the coating layer was 220 ° C.

Example 5 A kneaded product (melting point: 180 ° C.) of polyvinylidene fluoride (75 wt%) and polychlorotrifluoroethylene (25 wt%) was used as a constituent material of the inner layer of the outer cover. A flexible tube for an endoscope was produced in the same manner as in Example 3.

The temperature of the constituent material of the inner layer at the time of forming the outer skin,
The constituent material temperatures of the outer layers were all 200 ° C.

(Comparative Example 1) A core material was produced in the same manner as in Example 1 except that no coating layer was provided on the outer periphery of the fine wire.

Next, a polyurethane elastomer (product name: T818) was formed on the outer periphery of the core material by extrusion molding.
0, manufactured by Dainippon Ink and Chemicals, melting point: 170 ° C)
And a flexible tube for an endoscope having a length of 1.5 m was produced. In addition, the outer shell material temperature at the time of extrusion molding,
200 ° C. The average thickness of the outer skin of the obtained flexible tube for an endoscope was 0.5 mm.

(Comparative Example 2) A polyamide resin (product name:
Performed except that Novamid 1010C, manufactured by Mitsubishi Engineering-Plastics Co., Ltd., melting point: 225 ° C.) and polyurethane elastomer (product name: T8180, manufactured by Dainippon Ink and Chemicals, Inc., melting point: 170 ° C.) A flexible tube for an endoscope was manufactured in the same manner as in Example 1.

The formation of the coating layer was carried out at a material temperature of 2
It was carried out by extrusion at a temperature of 40 ° C. The temperature of the shell material during extrusion molding was 200 ° C.

The average thickness of the coating layer and the average thickness of the outer skin were 0.03 mm and 0.5 mm, respectively.

[0127] 2. Evaluation The chemical resistance and durability of each flexible tube for an endoscope produced in each example and each comparative example were evaluated by the tests described below.

[2.1] Elasticity test First, each endoscope flexible tube prepared in each of the examples and comparative examples was placed in dimethylformamide (DMF) at 25 ° C. for 48 hours.
Soaked for hours. Thereafter, the surface of the flexible tube for an endoscope was sufficiently washed with water and dried.

Thereafter, an operation of bending the tube at 90 ° while supporting both ends of each flexible tube for an endoscope was performed, and the elasticity at that time was evaluated according to the following four criteria. The lower the elasticity, the lower the chemical resistance. ◎: Very excellent elasticity, ideal for use as a flexible tube for endoscopes. ：: Excellent elasticity, suitable for use as a flexible tube for an endoscope. Δ: The elasticity was somewhat poor, and there was a problem in use as a flexible tube for an endoscope. X: Poor elasticity, not suitable for use as a flexible tube for an endoscope. Table 1 shows the results.

Further, this bending operation was repeated (a total of 300 times), and the elasticity at the end of this bending repeated operation was evaluated in the same manner as described above. The decrease in elasticity is caused by internal peeling of the outer skin (peeling of the outer skin from the core material). Therefore, the more the elasticity is maintained, the more excellent the durability. Table 1 shows the results.

[2.2] Peel Strength Test First, each endoscope flexible tube prepared in each of the examples and comparative examples was subjected to dimethylformamide (DMF) at 25 ° C. for 48 hours.
Soaked for hours. Thereafter, the surface of the flexible tube for an endoscope was sufficiently washed with water and dried.

Thereafter, a U-shaped cut was made in the outer skin of each flexible tube for an endoscope, and the peel strength at the time of peeling the outer skin of this portion was measured. The measurement of this peeling strength uses a digital force gauge, and with respect to the axial direction of the flexible tube for an endoscope,
This was done by pulling at an angle of 30 °. Table 1 shows the relative strength when the peel strength of the outer skin of the flexible tube for an endoscope having no coating layer (Comparative Example 1) is set to 1.

[0133]

[Table 1]

As is clear from Table 1, the flexible tube for an endoscope of the present invention has excellent elasticity (elasticity at the first bending operation and at the 300th bending operation) in the elasticity test and the peel strength test. And peeling strength of the outer skin, and as a result, it was confirmed to have excellent chemical resistance and durability. In particular, the flexible tube for an endoscope according to the second embodiment has a smaller average thickness of the outer skin (the sum of the average thickness of the inner layer and the average thickness of the outer layer) than that of the first embodiment. It had the same elasticity and peel strength as the flexible tube for an endoscope of Example 1.

On the other hand, the flexible tube for an endoscope of the comparative example is
It was inferior in elasticity and skin peel strength, and inferior in chemical resistance and durability.

[0136]

As described above, according to the present invention, chemical resistance and durability can be imparted to a flexible tube for an endoscope.

In the case where the outer skin is a laminated body in which a plurality of layers are stacked, the thickness of the outer skin necessary for obtaining sufficient chemical resistance and durability as compared with the case where the outer skin is constituted by a single layer. Can be made thinner. Therefore, the diameter of the flexible tube for an endoscope can be reduced. In addition, the selection of the material of each layer and the setting of the thickness and the like are appropriately performed, and by combining the characteristics of each layer, the advantages of the material constituting each layer can be obtained,
As a result, various performances required for the flexible tube for an endoscope can be simultaneously improved.

[Brief description of the drawings]

FIG. 1 is an overall view showing an electronic endoscope having an insertion portion flexible tube to which an endoscope flexible tube of the present invention is applied.

FIG. 2 is an enlarged semi-longitudinal sectional view showing a first embodiment of an insertion portion flexible tube to which the flexible tube for an endoscope of the present invention is applied.

FIG. 3 is an enlarged sectional view of a mesh tube constituting the flexible tube for an endoscope of the present invention.

FIG. 4 is an enlarged cross-sectional view showing a state in the vicinity of a mesh tube of the flexible tube of the insertion portion shown in FIG. 2;

FIG. 5 is an enlarged semi-longitudinal sectional view showing a second embodiment of an insertion portion flexible tube to which the flexible tube for an endoscope of the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insertion part flexible tube 2 Core material 21 Spiral tube 22 Reticulated tube 23 Fine wire 231 Coating layer 24 Space 25 Interval 26 Gap 3 Outer skin 31 Projection 32 Inner layer 33 Outer layer 5 Bending part 6 Operation part 61, 62 Operation knob 7 Connection possible Flexible tube 8 Light source insertion part 81 Light source connector 82 Image signal connector 10 Electronic endoscope

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kikuo Iwasaka, Inventor: Asahi Gaku Kogyo Co., Ltd. 2-36-9 Maenocho, Itabashi-ku, Tokyo (72) Minoru Matsushita 2-36-9, Maenocho, Itabashi-ku, Tokyo No. Asahi Gaku Kogyo Co., Ltd. F term (reference) 4C061 AA00 BB00 CC06 DD03 FF26 JJ03 JJ06 LL02 MM00 NN10

Claims (12)

[Claims] 1. A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on the outer periphery of the core material, wherein at least a portion of the outer skin facing the core material includes: A flexible tube for an endoscope, comprising a material containing a fluorine-based resin having a melting point of 300 ° C. or lower. 2. A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on an outer periphery of the core material, wherein the core material is formed by spirally winding a strip material. And a braided body formed by braiding a thin wire, wherein at least one of the fine wires has a coating layer made of a material containing a fluorine-based resin having a melting point of 300 ° C. or less. A flexible tube for an endoscope, wherein the flexible tube is formed. 3. A flexible tube for an endoscope having a core material having a hollow portion and an outer skin coated on an outer periphery of the core material, wherein the core material is formed by spirally winding a band material. And a braided body formed by braiding a thin wire, and a portion of the outer skin facing the braided body has a melting point of 300.
A first material containing a fluorine resin having a melting point of 300 ° C. or less, and a coating layer made of a second material containing a fluorine resin having a melting point of 300 ° C. or less is formed on at least one of the fine wires. A flexible tube for an endoscope. 4. The method according to claim 1, wherein the second material is the same as the first material.
The flexible tube for an endoscope according to claim 3, which contains 5 wt% or more. 5. The flexible tube for an endoscope according to claim 3, wherein a melting point of the first material is lower than a melting point of the second material. 6. The coating layer has an average thickness of 0.01 to 0.01.
The flexible tube for an endoscope according to any one of claims 2 to 5, which is 0.1 mm. 7. The flexible tube for an endoscope according to claim 1, wherein the outer skin is formed by extrusion molding. 8. The flexible tube for an endoscope according to claim 1, wherein the melting point of the fluororesin is 262 ° C. or less. 9. The flexible tube for an endoscope according to claim 8, wherein the fluorine-based resin is mainly polyvinylidene fluoride or the same. 10. The flexible tube for an endoscope according to claim 1, wherein the outer skin has a laminated portion in which a plurality of layers are laminated. 11. The outer shell, wherein the innermost layer is made of a fluorine-based resin having a melting point of 300 ° C. or less, and a portion other than the innermost layer is made of a material containing a polyurethane-based resin or a polyurethane-based elastomer. The flexible tube for an endoscope according to claim 10, wherein 12. The average thickness of the outer skin is 0.01 to
The flexible tube for an endoscope according to any one of claims 1 to 11, which is 1.5 mm.