JP2002153418A - Outer skin material, manufacturing method for flexible tube for endoscope and flexible tube for endoscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible tube for an endoscope with excellent chemical resistance. SOLUTION: This flexible tube 1 for endoscope is composed of a core material 2 and an outer skin 3. The core material 2 is composed of a helical tube 21 and a net-like tube 22, and the outer skin 3 is formed by putting an outer skin material on the outer periphery of the core material 2 by extrusion molding. The outer skin material is prepared by using at least a first molecule having two or more hydroxyl groups within the molecule, a second molecule having two or more hydroxyl groups within the molecule and a crosslinker having two or more functional groups capable of reacting with the hydroxyl groups within the molecule. It is preferable that the first molecule is for supplying flexibility to the outer skin material and the second molecule is for supplying the chemical resistance to the outer skin material. Also, it is preferable that the crosslinker is provided with two or more isocyanate groups within the molecule. It is preferable that the outer skin is formed by putting the outer skin material on the core material by extrusion molding. It is preferable that the ratio of the crosslinker to the total amount of the entire components used for preparing the outer skin material is 0.1-20 wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sheath material for a flexible tube for an endoscope, a method for manufacturing the flexible tube for an endoscope, and a flexible tube for an endoscope.

[0002]

2. Description of the Related Art In an endoscopic examination, it is necessary to insert a flexible tube of an endoscope into a body cavity such as a stomach, a duodenum, a small intestine or a large intestine. For this reason, the insertion section flexible tube of the endoscope has an outer skin of the flexible tube for the endoscope, thereby improving the ease of insertion operation (flexibility) and reducing the burden on the patient. In addition, it prevents liquids such as body fluids from entering the inside of the endoscope. Conventionally, an elastic material such as a polyurethane-based resin is generally used as a constituent material of the outer skin of the flexible tube for an endoscope.

[0003] Since endoscopes are used repeatedly, they must be cleaned and disinfected each time. However, the conventional materials are inferior in chemical resistance. For this reason, if cleaning and disinfection are repeatedly performed on the endoscope, the outer skin deteriorates. Then, the flexibility (flexibility) of the outer skin of the flexible tube for the endoscope itself is reduced, which causes a problem that it becomes difficult to insert the flexible tube into the lumen. Further, when the deterioration is severe, fine cracks or the like are generated, and the constituent material of the outer skin of the flexible tube for an endoscope may be peeled off.

[0004]

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

[0005]

This and other objects are achieved by the present invention which is defined below as (1) to (13).

(1) An outer shell material for forming an outer peripheral portion of a flexible tube for an endoscope, comprising: a first molecule having at least two hydroxyl groups in a molecule; It is prepared using a second molecule having a hydroxyl group and a crosslinking agent having two or more functional groups capable of reacting with a hydroxyl group in the molecule, and the first molecule and the second molecule are interposed via the crosslinking agent. An outer skin material characterized by being bound to a molecule of

Thus, it is possible to provide an outer shell material and a flexible tube for an endoscope having excellent chemical resistance.

(2) The envelope material according to (1), wherein the first molecule imparts flexibility to the envelope material.
Thereby, the flexibility of the outer shell material is improved.

(3) The envelope material according to (2), wherein the first molecule is a urethane polymer. This allows
The flexibility of the shell material is further improved.

(4) The envelope material according to (2) or (3), wherein the second molecule imparts chemical resistance to the envelope material. Thereby, the chemical resistance of the outer cover material is further improved.

(5) The envelope material according to (4), wherein the second molecule is an ester polymer. This allows
The chemical resistance of the shell material is further improved.

(6) The above (4) or (5), which is prepared using 0.1 to 3 parts by weight of the first molecule per 1 part by weight of the second molecule. The outer shell material according to (1). Thereby, the chemical resistance of the outer cover material is further improved.

(7) The method according to (4) or (5), wherein the first molecule is prepared by using more than 3 parts by weight and not more than 10 parts by weight with respect to 1 part by weight of the second molecule. The skin material as described. Thereby, the flexibility of the outer cover material is further improved.

(8) The envelope material according to any one of the above (1) to (7), wherein the crosslinking agent has two or more isocyanate groups in a molecule.

As a result, properties such as chemical resistance, heat resistance, flexibility and the like of the outer cover material as a whole become particularly excellent.

(9) The ratio of the crosslinking agent used for preparing the shell material to the total amount of all the constituent components used for preparing the shell material is 0.1 to 20% by weight. A method for producing a flexible tube for an endoscope according to the present invention.

As a result, properties such as chemical resistance, heat resistance, flexibility and the like of the outer shell material as a whole become particularly excellent.

(10) On the outer periphery of a core material having a hollow portion,
A method for producing a flexible tube for an endoscope, comprising a step of coating the outer cover material according to any one of the above (1) to (9) to form an outer cover. Thereby, a flexible tube for an endoscope having excellent chemical resistance can be provided.

(11) The method for producing a flexible tube for an endoscope according to the above (10), wherein the coating of the outer cover material is performed by extrusion molding. Thereby, the adhesion between the outer skin and the core material is improved.

(12) The average thickness of the outer skin is 0.0
The method for producing a flexible tube for an endoscope according to the above (10) or (11), which is 1 to 0.8 mm.

Thus, the flexibility and chemical resistance of the flexible tube for an endoscope can be further improved.

(13) A flexible tube for an endoscope manufactured by the method according to any one of the above (10) to (12). Thereby, a flexible tube for an endoscope having excellent chemical resistance can be provided.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of an outer cover material, a method for manufacturing an endoscope flexible tube, and an endoscope flexible tube according to the present invention will be described below with reference to the accompanying drawings.

First, an example of the entire configuration of an endoscope having the flexible tube for an endoscope of the present invention will be described.

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 insertion portion flexible tube 1 of a long object having flexibility (flexibility) and at a distal end portion of the insertion portion flexible 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 curved 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 tip 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 section 5, the insertion section flexible tube 1, the operation section 6 and the connection section 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.

Next, an example of an insertion portion flexible tube to which the endoscope flexible tube of the present invention is applied will be described.

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

As shown in FIG. 2, the flexible tube 1 has a core material 2 and an outer skin 3 covering the outer periphery thereof. In addition, a space 2 in which a built-in component such as an optical fiber, an electric cable, a cable or a tube (not shown) or the like (omitted in the drawing) is inserted and inserted into the flexible tube 1 of the insertion portion.
4 are provided.

The core 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 belt-like 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.

The mesh tube 22 is formed by braiding a plurality of thin wires 23 made of metal or nonmetal. 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. Further, at least one of the fine wires 23 forming the mesh tube 22 may be coated with a synthetic resin (not shown).

When at least one of the thin wires 23 forming the mesh tube 22 is coated with a synthetic resin, the coated resin (coating layer) is made of a constituent material of the outer cover 3 (at least of the outer cover 3). It is preferable that the material has excellent compatibility with the material constituting the inner peripheral surface). Thereby, the thin line 23
And the outer skin 3 are sufficiently strongly bonded to each other, and the outer skin 3 and the core 2
And the adhesion to the film is improved. For this reason, the close contact state between the outer cover 3 and the core 2 is maintained even when the flexible tube 1 is bent. In addition, since the bonding force between the outer cover 3 and the core member 2 is strong, the outer cover 3 and the core member 2 are not easily separated from each other even when the insertion portion flexible tube 1 is used repeatedly. Therefore, the insertion portion flexible tube 1
Has excellent durability.

On the outer periphery of the braided tube 22, a braided thin wire 2
A gap 26 is formed by the third stitch. 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.

An outer skin 3 is provided on the outer periphery of the core material 2. The outer skin 3 is formed by coating the outer periphery of the core material 2 with an outer skin material 32 of the present invention described later in detail.

A large 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 as described above, 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. For this reason, the close contact state between the outer cover 3 and the core 2 is maintained even when the flexible tube 1 is bent. Therefore, the flexible tube 1 is excellent in elasticity. In addition, since the bonding force between the outer cover 3 and the core member 2 is strong, the outer cover 3 and the core member 2 are not easily separated from each other even when the insertion portion flexible tube 1 is used repeatedly. Therefore, the flexible tube 1 is excellent in durability.

In particular, when the thin wire 23 is provided with a coating layer made of a synthetic resin having excellent compatibility with the constituent material of the outer cover 3 (at least the material forming the inner peripheral surface of the outer cover 3), When these effects act synergistically, the durability of the flexible tube 1 becomes more excellent.

The average thickness of the outer cover 3 (excluding the protrusion 31) is not particularly limited, but is preferably 0.01 to 0.8 mm, more preferably 0.05 to 0.7 mm. preferable.

If the average thickness of the outer cover 3 is less than the lower limit, the mechanical strength of the outer cover 3 is reduced, and the durability of the flexible tube for an endoscope is reduced. There is a possibility that a liquid such as a body fluid may enter the inside.

On the other hand, if the average thickness of the outer cover 3 exceeds the upper limit, the flexibility (flexibility) of the flexible tube 1 may be reduced.

In the illustrated configuration, the thickness of the outer cover 3 is
It is constant along the longitudinal direction, but may change along the longitudinal direction.

Next, the skin material of the present invention will be described. The shell material 32 constituting the shell 3 includes at least a first molecule having two or more hydroxyl groups in the molecule, a second molecule having two or more hydroxyl groups in the molecule, and a functional group capable of reacting with the hydroxyl group. It is prepared using a crosslinking agent having two or more groups in the molecule. Here, the first molecule and the second molecule
Are different from each other in physical properties, chemical properties (collectively referred to as “physical properties”), or compositions. Physical properties include, for example, rigidity (flexibility),
Heat resistance, hardness, elongation, tensile strength, shear strength, flexural modulus, flexural strength, etc. are listed.
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.

In the envelope material 32, the first molecule and the second molecule are bonded via a cross-linking agent. As a result, the envelope material 32 has both the advantages of the first molecule and the advantages of the second molecule, and complements the respective disadvantages.

As the first molecule and the second molecule, any one may be used as long as it has two or more hydroxyl groups in the molecule. Examples thereof include a polyurethane resin and a polyester resin. , Polyvinyl alcohol (including polyvinyl acetate in which at least a part of the ester in the molecule is hydrolyzed), and ethylene-vinyl alcohol copolymer (ethylene-vinyl acetate in which at least a part of the ester in the molecule is hydrolyzed) (Including copolymers, etc.), (modified) polyolefin-based resins, and various polymeric materials such as polyurethane-based elastomers, polyester-based elastomers, polyethylene-based elastomers, and (modified) polyolefin-based elastomers. . The hydroxyl group may be present at the terminal of the main chain of the first molecule or the second molecule, or may be present at another site.

As for the combination of the first molecule and the second molecule, it is preferable that one of them gives flexibility to the outer material and the other gives chemical resistance to the outer material. Thereby, the outer cover material 32 has excellent flexibility and chemical resistance as a whole. In addition, by using such a combination, heat resistance is also improved. Therefore, a flexible tube for an endoscope manufactured using such an outer shell material has particularly excellent performance.

The molecules that impart flexibility to the shell material include:
For example, urethane-based polymer materials such as polyurethane-based resin and polyurethane-based elastomer can be used. Also,
Examples of the molecule that imparts chemical resistance to the outer cover material include ester polymers such as polyester resins and polyester elastomers.

The compounding ratio of the first molecule and the second molecule used for preparing the outer shell material 32 is not particularly limited, and various characteristics such as flexibility, chemical resistance and heat resistance required for the endoscope are used. It is appropriately selected according to the conditions.

Hereinafter, a case where a material that gives flexibility to the skin material as the first molecule and a material that imparts chemical resistance to the skin material as the second molecule will be described.

If the outer shell material 32 is prepared using 0.1 to 3 parts by weight of the first molecule with respect to 1 part by weight of the second molecule, the chemical resistance of the outer shell 3 The properties are particularly excellent. Such an effect is achieved by the outer skin material 32.
Is 0.5 parts by weight or more and 3 parts by weight with respect to 1 part by weight of the second molecule.
It is more remarkable if the first molecule is prepared using not more than 1 part by weight of the first molecule, and 1 part by weight to 3 parts by weight of the first molecule is used for 1 part by weight of the second molecule. It becomes even more remarkable if it is prepared in advance.

Further, when the outer shell material 32 is prepared by using more than 3 parts by weight and not more than 10 parts by weight of the first molecule with respect to 1 part by weight of the second molecule, the flexibility of the outer shell 3 is improved. Is particularly excellent. Such an effect is achieved by the outer skin material 32.
Is more remarkable when prepared using 5 to 10 parts by weight of the first molecule with respect to 1 part by weight of the second molecule, and 1 part by weight of the second molecule for,
The use of 6 to 9 parts by weight of the first molecule is more remarkable when the first molecule is prepared.

The cross-linking agent used for preparing the envelope material 32 of the present invention has two or more functional groups capable of reacting with a hydroxyl group in the molecule. As the functional group capable of reacting with a hydroxyl group, an isocyanate group (—NCO), a carboxyl group (—COO)
H) and a thioisocyanate group (-NCS). One or more functional groups selected from these are present in the molecule of the crosslinking agent.

The crosslinking agent preferably has an isocyanate group, and more preferably has two or more isocyanate groups in the molecule, among the functional groups capable of reacting with the hydroxyl group described above. By using such a cross-linking agent, the cross-linking reaction proceeds more efficiently, so that the chemical resistance, heat resistance, and permanent set resistance of the outer cover material 32 are particularly excellent.

Examples of the crosslinking agent having two or more isocyanate groups in the molecule include m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4 ′
-Diphenyl diisocyanate, 1,5-naphthalenediisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4- or 2,6-tolylene diisocyanate or a mixture thereof, 4,4'-toluidine diisocyanate, 2,2'-dimethyldiphenyl −4
4'-diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, 4,4'-diphenylether diisocyanate, 1,3- or 1,4-
Xylylene diisocyanate or a mixture thereof, ω,
ω′-diisocyanate 1,4-diethylbenzene,
1,3- or 1,4-bis (1-isocyanate 1-
Methylethyl) benzene (common name: tetramethylxylylene diisocyanate) or a mixture thereof,
Cyclopentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-
Trimethylcyclohexyl isocyanate (common name: isophorone diisocyanate), 4,4'-methylenebis (cyclohexyl isocyanate), methyl-2,4-
Cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3- or 1,4
-Bis (isocyanatomethyl) cyclohexane (common name: hydrogenated xylylene diisocyanate) or a mixture thereof, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate,
Pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4
-Trimethylhexamethylene diisocyanate, 2,6
Diisocyanates such as diisocyanate methylcaproate, triphenylmethane-4,4 ′, 4 ″ -triisocyanate, 1,3,5-triisocyanatebenzene, 2,4,6-triisocyanatetoluene,
3,5-triisocyanate methylbenzene, 1,3
5-triisocyanatecyclohexane, 1,3,5-
Trimethyl isocyanate cyclohexane, 2- (3-
Isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 2-
(3-isocyanatopropyl) -2,6-di (isocyanatomethyl) -bicyclo (2.2.1) heptane,
3- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl )-
Bicyclo (2.2.1) heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3
-Isocyanatopropyl) -bicyclo (2.2.1)
Heptane, 5- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo (2.2.1) -heptane, 6- (2-
Isocyanatoethyl) -2-isocyanatomethyl-
2- (3-isocyanatopropyl) -bicyclo (2.
2.1) heptane, lysine ester triisocyanate, 1,4,8-triisocyanate octane, 1,6
11-triisocyanate decane, 1,8-diisocyanate 4-isocyanatomethyloctane, 1,3
Triisocyanates such as 6-triisocyanate hexane, 2,5,7-trimethyl-1,8-diisocyanate 5-isocyanatomethyloctane, and 4,4′-diphenylmethane-2,2 ′, 5,5′-tetraisocyanate Examples include polyisocyanates such as tetraisocyanate and polymeric MDI, and polymers containing at least one of these (dimers, trimers, oligomers, prepolymers, polymers, copolymers, and the like).

Further, two or more of the above-mentioned crosslinking agents may be used in combination.

When a crosslinking agent having two isocyanate groups in the molecule is used, the reaction with the first molecule, the second molecule and the crosslinking agent proceeds as in the following formula (I). . However, HO-R-OH, HO-R'-OH, OC
NR ″ -NCO indicates a first molecule, a second molecule, and a cross-linking agent, respectively.

HO—R—OH + HO—R′—OH + OCN—R ″ —NCO → HO—R—O—OCHN—R ″ —NHCO—O—R′—OH (I) As described above, in the envelope material 32, the first molecule and the second molecule are bonded via the cross-linking agent.

Thus, the envelope material 32 has both the advantages of the first molecule and the advantages of the second molecule, and complements the respective disadvantages.

For example, when a material that gives flexibility to the envelope material 32 as the first molecule and a material that imparts chemical resistance to the envelope material 32 is used as the second molecule, the first molecule has poor chemical resistance. , Even those that are easily soluble in solvents,
By binding the first molecule to the second molecule via the cross-linking agent, the first molecule can be effectively prevented from being eluted into the solvent. As a result, the chemical resistance of the outer cover material 32 as a whole is improved. In addition, since the first molecule is used as a constituent component, the flexibility of the outer shell material as a whole is also excellent.

The above formula shows an example of a reaction that proceeds when each component is mixed. When mixing each component, a reaction other than the above formula may also proceed. For example, the hydroxyl groups at both ends of the product in the above formula may be further bonded to the first molecule and the second molecule via a crosslinking agent. The degree of polymerization can be adjusted by appropriately selecting various reaction conditions such as the mixing ratio of each component. Further, at the time of mixing each component, for example, via a crosslinking agent,
A reaction for forming a bond between the first molecules and a bond between the second molecules may occur.

The ratio of the cross-linking agent to the total amount of all the components used for preparing the shell material 32 (when two or more cross-linking agents are used in combination, the total amount thereof) is 0.1 to 20.
wt%, more preferably 4 to 15 wt%, even more preferably 11 to 14 wt%. When the ratio of the cross-linking agent to the total amount of all the components used for preparing the shell material 32 is within such a range, the bond between the first molecule and the second molecule via the cross-linking agent is efficiently formed. The properties of the outer cover material 32 as a whole are particularly excellent.

In preparing the envelope material 32, components other than these may be used in addition to the above-described first molecule, second molecule, and crosslinking agent. Such components include, for example, polyvinyl chloride, polyethylene, polypropylene,
Various flexibility such as polyolefin resin such as ethylene-vinyl acetate copolymer, polyamide resin, polystyrene resin, polyimide resin, polytetrafluoroethylene and fluorine resin such as ethylene-tetrafluoroethylene copolymer. Resin, or a polymer material such as polyolefin-based elastomer, polyamide-based elastomer, polystyrene-based elastomer, fluorine-based elastomer, various elastomers such as silicone rubber, ethylene propylene rubber, and latex rubber. More than one species can be used in combination.

In the preparation of the envelope material 32, it is possible to use one or more molecules having different compositions and physical properties from the first molecule and the second molecule and having two or more hydroxyl groups in the molecule. Good. Thereby, three or more kinds of molecules having two or more hydroxyl groups in the molecule can be bonded via the cross-linking agent, and the properties of the outer cover material 32 can be further improved. .

In preparing the shell material 32, additives may be used as 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.

Next, an example of a method for manufacturing the above-described flexible tube for an endoscope will be described. First, the core material 2 is manufactured. The core material 2 can be produced, for example, by coating the outer periphery of the spiral tube 21 with a braided tube 22 (braided body). The outer periphery of the spiral tube 21 may be coated with the mesh tube 22 (braided body) by any method, but is preferably performed in a state where the spiral tube 21 is wound around the cored bar 9. Thereby, the spiral tube 2
1 is stable, and the coating of the braided tube (braided body) 22 can be easily performed. The core 9 is, for example, the core 2
Is removed after coating the outer skin material 32 on the outer periphery of the cover.

Next, the outer skin 3 is formed by coating the outer periphery of the core material 2 thus obtained with the outer skin material 32.

The outer shell material 32 is obtained by mixing and kneading the above-mentioned components. For 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.

The kneading temperature is not particularly limited, but is preferably, for example, about 180 to 240 ° C.
About 220 ° C., more preferably 190 to 21 ° C.
More preferably, it is about 0 ° C. When the components are kneaded in such a temperature range, the crosslinking reaction between the first molecule and the second molecule via the crosslinking agent proceeds efficiently, and the properties (flexibility, chemical resistance, Heat resistance etc.)
Especially excellent.

The method of coating the core material 2 with the outer cover material 32 is not particularly limited, but it can be easily coated by extrusion molding as described below.

FIG. 3 is a longitudinal sectional view of a die head portion of an extruder in which a core material is covered with a shell material by extrusion molding. In the following description, the left side in FIG. 3 will be described as “distal end” and the right side as “base end”.

The die head 4 has a die 41 and a nipple 42. The die head 4 has a passage 43 having a circular cross section penetrating from the base end to the tip.

The core material 2 wound around the core bar 9 is inserted concentrically into the passage 43, and is moved in a longitudinal direction (direction of arrow A in FIG. 3) from the base end to the tip by a transfer means (not shown). Moving.

Inside the die head 4, a skin material passage 44 is formed by the die 41 and the nipple 42. The distal end of the sheath material passage 44 is circumferentially opened in the passage 43 and forms an extrusion port 45.

The outer shell material 32 introduced into a hopper (not shown) is sequentially fed into the outer shell material passage 44 by a screw (not shown) in a cylinder (not shown) (arrow B in FIG. 3). Department). Outer skin material 32
Is extruded from the extrusion port 45 through the sheath material passage 44 and is sequentially coated on the outer periphery of the core material 2 moving in the longitudinal direction.

At this time, the outer cover 3 is preferably coated so as to embed at least a part of the core material 2 (the mesh tube 22 and the spiral tube 21). As a result, the following effects can be obtained.

When the protrusions 31 are efficiently formed, the bonding force between the outer cover 3 and the core 2 is increased, and the outer cover 3 is less likely to be separated (separated) from the core 2. -The durability of the outer cover 3 is improved, and cracks and the like are less likely to occur. The outer diameter of the flexible tube 1 can be reduced (or the inner diameter can be increased) while maintaining performance such as strength.

The temperature of the shell material 32 during extrusion molding is not particularly limited, but is preferably, for example, about 180 to 240 ° C., and more preferably about 190 to 210 ° C. When the temperature of the outer cover material 32 during the extrusion molding is in such a temperature range, the moldability of the outer cover material is particularly excellent. Therefore, the uniformity of the thickness of the outer skin of the flexible tube for an endoscope is improved.

After the outer skin 2 is formed on the outer periphery of the core member 3 in this way, the core tube 9 is removed, whereby the flexible tube 1 for the insertion portion is obtained.

The outer shell material, the method for manufacturing the endoscope flexible tube, and the endoscope flexible tube of the present invention have been described above.
The present invention is not limited to these.

For example, the outer skin may be a laminate of two or three or more layers. Each layer of such an outer skin can be composed of materials having different physical or chemical properties from each other. Thereby, various performances required for the flexible tube for an endoscope can be simultaneously improved by combining the properties of the respective layers of the outer skin.

For example, when the outer skin is composed of an inner layer provided on the outer circumference of the core material and an outer layer provided on the outer circumference, a material having excellent adhesion to the core material is used for the inner layer. By doing so, the outer skin can be securely fixed by the core material.

Further, by using a material having excellent elasticity for the inner layer, the inner layer acts as a cushion between the outer layer and the spiral tube, and the elasticity of the flexible tube for an endoscope can be improved. can do.

When the outer skin is a laminate of a plurality of layers, at least one layer may be made of the above-described outer skin material.

The outer skin may be formed of such a laminated body over its entire length, or may be formed of such a laminated body for a part in the longitudinal direction.

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.

[0093]

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

1. Production of flexible tube for endoscope (Example 1)

[1.1] Manufacture of core material First, a stainless steel band material having a width of 3 mm was wound around the outer periphery of a cylindrical metal core to have an outer diameter of 9.9 mm and an inner diameter of 9.6 mm.
Was made.

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. As a constituent material of the coating layer, 5% by weight of a polyurethane elastomer (product name: Pandex, manufactured by Dainippon Ink and Chemicals, Inc.),
A kneaded product of 95% by weight of a polyamide resin (product name: Daiamide, manufactured by Daicel Huls Co., Ltd.) was used. This coating layer was formed by extrusion molding. The average thickness of the coating layer was 0.05 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.

[1.2] Preparation of Skin Material First, a polyurethane-based elastomer (product name: Pelecene,
Dow Chemical Co., Ltd.), polyester elastomer (product name: Hytrel, manufactured by Toray Dupont Co., Ltd.), and 4,4'-diphenylmethane diisocyanate were prepared.

Using a kneader, 0.15 parts by weight of a polyurethane-based elastomer (TPU), 1 part by weight of a polyester-based elastomer (TPEE), and 13% by weight of a crosslinking agent are kneaded for 30 minutes to prepare a shell material. did.
The material temperature during kneading was 210 ° C.

[1.3] Coating of Outer Shell Material on Outer Periphery of Core Material An outer skin is formed by coating the outer periphery of the core material with an outer skin material by extrusion molding. A 5 m flexible tube for an endoscope was obtained. In addition, the temperature of the skin material at the time of extrusion molding was 210 ° C. The average thickness of the formed outer skin was 0.3 mm.

(Examples 2 to 6) Except that the mixing ratio (weight ratio) of the polyurethane-based elastomer, polyester-based elastomer and crosslinking agent used for preparing the shell material was changed as shown in Table 1, In the same manner as in Example 1, a flexible tube for an endoscope was manufactured.

(Comparative Example) A flexible tube for an endoscope was manufactured in the same manner as in Example 1 except that no cross-linking agent was used in the preparation of the envelope material. Table 1 summarizes the mixing ratios of the components used in the preparation of the shell material for each of the examples and comparative examples.

[0103]

[Table 1]

2. Evaluation of characteristics of flexible tube for endoscope [2.1] Flexibility / elasticity test The flexibility / elasticity test was performed on each flexible tube for endoscope manufactured in each of the examples and comparative examples.

In the flexibility / elasticity test, each endoscope flexible tube was bent at 90 ° while supporting both ends, and the flexibility and elasticity at that time were evaluated according to the following four-grade criteria. . ：: Excellent in flexibility and elasticity, ideal for use as a flexible tube for endoscopes. ：: Excellent in flexibility and elasticity, suitable for use as a flexible tube for an endoscope. Δ: The flexibility and elasticity were somewhat poor, and there was a problem in use as a flexible tube for an endoscope. ×: Poor flexibility and elasticity, not suitable for use as flexible tube for endoscope. Table 2 shows the results of the flexibility and elasticity tests.

[2.2] Chemical Resistance Test Each endoscope flexible tube manufactured in each of the examples and comparative examples was subjected to a chemical resistance test.

In the chemical resistance test, each flexible tube for an endoscope was immersed in N, N-dimethylformamide (DMF) kept at a temperature of 25 ° C. for 168 hours. The observation was performed by observing the outer skin of the flexible tube. The case where the outer skin was not dissolved was evaluated as ◎ and the case where the outer skin was dissolved was evaluated as x.

Also, N, N-dimethylformamide (D
The same test was performed using tetrahydrofuran (THF) and chloroform instead of MF). Table 2 shows the results of the chemical resistance test.

[2.3] Heat Resistance Test Each endoscope flexible tube manufactured in each of the examples and comparative examples was subjected to a heat resistance test.

In the heat resistance test, a heat treatment at 130 ° C. for 15 minutes was repeated 20 times on each flexible tube for endoscope.
The evaluation was performed by observing the state of the outer skin of each flexible tube for an endoscope at that time, and evaluated according to the following four-grade criteria. A: No change in appearance. ：: Almost no change in appearance. Δ: The outer skin was deformed. ×: Deformation of the outer skin can be clearly recognized. Table 2 shows the results of the heat resistance test.

[2.4] Durability Test The endoscope flexible tube (immersed in DMF) of each of the examples subjected to the chemical resistance test and the durability of each of the examples subjected to the heat resistance test A durability test was performed on the flexible tube for an endoscope.

In the durability test, each endoscope flexible tube was bent at 90 ° while supporting both ends thereof, and the flexibility and elasticity at that time were evaluated according to the following four-grade criteria. ：: Excellent in flexibility and elasticity, ideal for use as a flexible tube for endoscopes. ：: Excellent in flexibility and elasticity, suitable for use as a flexible tube for an endoscope. Δ: The flexibility and elasticity were somewhat poor, and there was a problem in use as a flexible tube for an endoscope. ×: Poor flexibility and elasticity, not suitable for use as flexible tube for endoscope. Table 2 shows the results of the durability test.

[0113]

[Table 2]

As is clear from Table 2, the flexible tubes for endoscopes of the present invention were all excellent in chemical resistance and heat resistance. On the other hand, the flexible tube for an endoscope of the comparative example was inferior in chemical resistance and heat resistance.

Further, the flexible tube for an endoscope of the present invention had excellent flexibility and elasticity. Further, it was confirmed that excellent flexibility and elasticity were maintained and excellent durability was obtained after the chemical resistance test and the heat resistance test.

[0116]

As described above, according to the present invention, it is possible to obtain a flexible tube for an endoscope having excellent chemical resistance while maintaining excellent flexibility.

Further, since it has excellent heat resistance, a flexible tube for an endoscope which can be repeatedly subjected to steam sterilization or the like can be obtained.

Further, by appropriately changing the mixing ratio of each component used in the preparation of the outer shell material, it is possible to emphasize the flexibility of the outer shell, the chemical resistance, and obtain a flexible tube for an endoscope. Can be.

These effects are further remarkable by appropriately selecting the types of the first molecule, the second molecule and the cross-linking agent, and the functional group capable of reacting with the hydroxyl group existing in the molecule of the cross-linking agent. It will be.

[Brief description of the drawings]

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

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

FIG. 3 is a vertical cross-sectional view showing a step of forming an outer skin by coating the outer periphery of a core material with an outer skin material by extrusion molding.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insertion part flexible tube 2 Core material 21 Spiral tube 22 Reticulated tube 23 Fine wire 24 Space 25 Interval 26 Gap 3 Outer skin 31 Projection 32 Outer skin material 4 Dice head 41 Dice 42 Nipple 43 Passage 44 Outer material passage 45 Extruder 5 Curved portion Reference Signs List 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 core metal 10 electronic endoscope

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H040 BA00 DA03 DA15 DA16 3H111 AA02 BA34 CB23 DA08 DB21 EA01 4C061 AA00 BB00 CC00 DD03 FF26 JJ03 JJ06

Claims (13)

[Claims] 1. An envelope material forming an outer peripheral portion of a flexible tube for an endoscope, comprising: a first molecule having at least two hydroxyl groups in a molecule; and two or more hydroxyl groups in a molecule. And a cross-linking agent having two or more functional groups capable of reacting with a hydroxyl group in the molecule, and the first molecule and the second An outer shell material characterized by being bound to a molecule. 2. The envelope material according to claim 1, wherein the first molecule imparts flexibility to the envelope material. 3. The envelope material according to claim 2, wherein the first molecule is a urethane-based polymer. 4. The outer shell material according to claim 2, wherein the second molecule imparts chemical resistance to the outer shell material. 5. The envelope material according to claim 4, wherein the second molecule is an ester polymer. 6. The method according to claim 1, wherein said second molecule is present in an amount of 0.1 part by weight.
The envelope material according to claim 4 or 5, which is prepared using 1 to 3 parts by weight of the first molecule. 7. The envelope material according to claim 4 or 5, prepared using more than 3 parts by weight and not more than 10 parts by weight of the first molecule per 1 part by weight of the second molecule. . 8. The envelope material according to claim 1, wherein the crosslinking agent has two or more isocyanate groups in a molecule. 9. The method according to claim 1, wherein the ratio of the crosslinking agent used for preparing the shell material to the total amount of all the components used for preparing the shell material is 0.1 to 20% by weight. A method for manufacturing a flexible tube for an endoscope. 10. A flexible endoscope comprising a step of coating the outer periphery of a core material having a hollow portion with the outer skin material according to claim 1 to form an outer skin. Pipe manufacturing method. 11. The method for manufacturing a flexible tube for an endoscope according to claim 10, wherein the coating of the outer cover material is performed by extrusion molding. 12. The average thickness of the outer skin is 0.01 to
The method for producing a flexible tube for an endoscope according to claim 10 or 11, which is 0.8 mm. 13. A flexible tube for an endoscope, manufactured by the method according to claim 10. Description: