JPH04341836A - Flexible tube and preparation thereof - Google Patents

Abstract

PURPOSE:To provide a method for preparation of a flexible tube with airtight properties, watertight properties, flexibility, kinking resistance, retention of shape, good slipperiness, chem. resistance and cleaning disinfection properties. CONSTITUTION:An inner layer 2 consisting of a thin film tube is formed on the outer periphery of a core body 11 by coating by means of extrusion molding and the outer surface of the inner layer 2 is made constant by performing grinding etching and chem. etching to make the thickness thin and to roughen the outer surface and an outer layer 3 is laminated on the roughened outer surface of the inner layer 2 to integrate both layers 2 and 3. In this case, the outer layer 3 is prepd. by inserting a net 5 as a reinforcing layer in a urethane resin layer 4 such as molten urethane resin which constitutes the main body part.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube suitable for forming a forceps channel in an endoscope used for medical purposes, and a method for manufacturing the same.

0002

[Prior Art] Endoscopes are generally used to treat the upper and lower gastrointestinal tracts.
It is used as the first diagnostic method for diagnosing organs. The purpose of this is to guide an image of the inside of the body outside the body using an image guide made of optical fiber or an imaging means such as a CCD, and to make a diagnosis by observing this image inside the body. This involves inserting forceps or other treatment tools through the forceps channel provided in the holder to perform surgeries such as hemostasis and removal of polyps.

[0003] For this reason, an endoscope has an operating section that is held and operated by an operator such as a doctor, an insertion section that is inserted into the patient's body, and a light source and transmitter for illuminating the patient's body. It consists of a connector section that connects to a device with pneumatic water supply function. The operation section is provided with a bending operation mechanism for controlling the tip of the insertion section to guide it to a target site in the body, an introduction port for the treatment tool, and the like. The insertion section includes an imaging means, a cable connected to the imaging means, a light guide fiber for internal illumination, a forceps channel for guiding the treatment instrument, a channel for air and water supply, and a portion near the tip of the insertion section. Wires and the like are incorporated to remotely control the bending operation of the bending section. In addition, the connector part has a light guide fiber,
Air and water tubes, cables, etc. are incorporated.

[0004] Among the above configurations, the forceps channel used has an inner diameter of about 1 mm to 5 mm depending on the purpose. Here, the tube body forming the treatment instrument insertion channel must be flexible so that it can follow and bend when the insertion section bends. In particular, since the curved part of the insertion part is curved with an extremely small radius of curvature, at least within this curved part of the treatment instrument insertion channel, it can be easily bent, and when the bend is released, it can be reliably bent. It must be possible to restore it to . Furthermore, since the treatment instrument is inserted into the treatment instrument insertion channel, at least the inner surface must be smooth in order to guide it smoothly. Furthermore, because endoscopes are, by their nature, cleaned after each use, they must be chemically resistant. For this purpose, the forceps channel must be airtight,
Watertightness, flexibility, kink resistance, shape retention, slipperiness,
Chemical resistance, cleaning and disinfection properties, etc. are required.

[0005] As a structure of a forceps channel tube that requires such characteristics, the following structures are conventionally known. First, JP-A-59-151933
The material shown in this issue is made of a porous material made of polytetrafluoroethylene (PTFE), and an elastic coating made of rubber or the like is formed on its outer surface to make it watertight and airtight. A reinforcing pipe member made of braided metal fibers is fitted on the outer side of the reinforcing pipe member, and a second elastic coating is formed on the outer side of the reinforcing pipe member, and the blade is covered with two layers of elastic coating. Embedded between the bodies, they are joined together as one. Also, JP-A-55-82884
The flexible tube disclosed in the No.
A device filled with a synthetic resin material having elasticity is disclosed.

[0006]

[Problems to be Solved by the Invention] In the above-mentioned two conventional examples, the flexible tube is made of porous fluororesin, and its inner and outer surfaces are coated with a coating, or a blade or coating is used. Since it has a structure in which a body is provided, it meets the requirements for flexibility and chemical resistance, but since it uses porous fluororesin, the inner surface has a structure with minute irregularities. , dirt and foreign matter get into the recesses,
This makes it difficult to eliminate these substances, making cleaning and disinfecting properties incomplete. Additionally, when making a forceps channel using this material, it is necessary to have a wall thickness of 0.5 mm or more in order to maintain the shape, resulting in an insertion part that is thick and has a large outer diameter, causing pain to the patient during examination. This makes it impossible to develop an endoscope with a small diameter that does not give Therefore, in order to improve cleaning and disinfection properties, it is possible to construct the fluorine tube with a non-porous fluorine tube, but if a non-porous fluorine tube is used, flexibility will be lost and the radius of curvature of the insertion portion will be reduced. It had problems such as not being able to make it smaller.

[0007]

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and the flexible tube has an inner layer tube made of polymer resin and a reinforced outer periphery of the inner layer tube. In a flexible tube formed by integrating an inner layer tube and an outer layer tube, the inner layer tube has a predetermined outer diameter and wall thickness made of crystalline polymer resin, and its outer peripheral surface is made of a crystalline polymer resin. The outer layer tube is formed with a roughened surface, and the outer layer tube is coated with an inner and outer thermoplastic urethane resin of a reinforcing layer, and the inner urethane coating layer is adhered to the roughened outer periphery of the inner layer tube, so that the inner layer tube and the outer layer tube are integrated. It is characterized by the fact that

[0008] Further, as a method for manufacturing a flexible tube,
In a method for manufacturing a flexible tube in which an inner layer tube made of a polymer resin and an outer layer tube with a reinforcing layer embedded in the outer periphery of the inner layer tube are provided and the inner layer tube and the outer layer tube are integrated, a crystalline polymer An inner tube forming process in which resin is extruded to have a predetermined outer diameter and wall thickness, a roughening process in which the outer circumferential surface of the inner tube is roughened, and thermoplastic urethane is applied to the outer circumference of the roughened inner tube. This method consists of a laminating step in which the inner layer of the outer tube is formed from a resin and the inner layer and the roughened surface are integrated, and is characterized in that the inner layer tube and the outer tube are integrated.

[0009]

[Function] In order to enable smooth and easy insertion of a treatment instrument into a flexible tube, the inner surface of the tube body must have good sliding properties. In this way, in order to satisfy slipperiness, chemical resistance, cleaning and disinfecting properties, etc., in the present invention, a fluororesin is used as the inner layer. However, the function of this inner layer is to reduce frictional resistance, and there is no need for it to have a shape-retaining function as a tube body, so it is possible to make it extremely thin. . As a result, sufficient flexibility can be provided without making it porous. Therefore, the inner surface becomes a completely smooth surface, which facilitates cleaning.

Next, as a structure, resilience against bending,
The ability to maintain shape is ensured by the outer layer laminated on the outer surface of the inner layer. This outer layer is constructed by embedding a thermoplastic resin layer such as urethane resin and a reinforcing layer formed by braiding metal strips into the resin layer, but since the reinforcing layer is braided, It is expandable and contractible with respect to the curvature of the tube body, and has a spring property, so that the restoring force against the curvature is large, so that it is possible to ensure the restorability and shape retention of the tube body. The outer layer in which the reinforcing layer is embedded is integrated with the inner layer to prevent the reinforcing layer from being exposed, and is bonded and integrated with the inner layer to prevent it from separating from the reinforcing layer due to curvature. Therefore, compared to a porous fluororesin that functions as a structure, it is possible to maintain sufficient strength even if the thickness is reduced, there is no risk of kinks, etc., and the overall It is possible to make the tube body thinner and smaller in diameter.

[0011]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the overall structure of a tube body constituting a treatment instrument insertion channel, and FIG. 2 shows its cross section. As is clear from these figures, the tube body 1 constituting the treatment instrument insertion channel is composed of an inner layer 2 and an outer layer 3. The inner layer 2 is made of a thin film tube made of a crystalline polymer resin, for example, a fluororesin, and the outer layer 3 is made of a thermoplastic resin, and a net 5 as a reinforcing layer is embedded in a urethane resin layer 4. It is. Here, the net 5 has spring properties such as hard stainless steel fiber, amorphous metal fiber, tungsten fiber, etc.
Constructed by braiding hard metal fibers.

The inner layer 2 is made of fluororesin, and is intended to improve the slippage of the inner surface of the tube body 1. Therefore, the inner layer 2 is a thin film with a thickness of about 0.03 to 0.2 mm. shall be. Furthermore, in consideration of cleanability and the like, the surface is extremely smooth and non-porous to reduce the coefficient of friction. In addition, the net 5 constituting the outer layer 3 is made of a material such as SUS 304 WPB with a diameter of approximately 0.0 mm in order to exhibit sufficient shape retention ability even when it is bent at the maximum angle in the curved part of the insertion part.
．． A hard stainless steel wire made of 1 mm wire is braided with 18 strokes and 2 strands. In addition, since the maximum angle angle at the curved portion may have a radius of curvature of approximately 15 mm, it is preferable that the bias angle be approximately 70 to 50 degrees in order to allow easy bending even in this case. . Furthermore, the urethane resin layer 4 in which the net 5 is embedded must be thick enough to completely cover the net 5, and the tube body 1 must be curved.
A soft material, such as 80° polyurethane, is preferably used in order to prevent the net 5 from creating resistance and distortion when it expands and contracts.

[0013] Here, the outer layer 3 consisting of the urethane resin layer 4 and the net 5 is bonded extremely firmly to the inner layer 2, so that it will not peel off from the interface even if it is repeatedly bent in any direction. must be maintained. Therefore, although the outer layer 3 and the inner layer 2 can be bonded using an adhesive, it is preferable that the urethane resin layer 4 constituting the outer layer 3 is laminated on the inner layer 2 by a molding means. favorable for However, if the urethane resin is directly laminated on the inner layer 2 made of a thin film of fluororesin having an extremely smooth surface, the two will not fit well together and will easily peel off. Therefore, an etching process is applied to the outer surface of the tube. After performing the etching process, the urethane resin layer 4 constituting the outer layer 3 is laminated on the inner layer 2, and the net 5 is embedded in the urethane resin layer 4. In order to easily and completely insert the urethane resin, it is preferable in terms of manufacturing to first form a layer of urethane resin on the inner layer 2, then cover the net 5 with the urethane resin. However, it is not necessarily necessary to form the urethane resin layer 4 into two layers.

[0014]The method for manufacturing this tube body 1 will be explained below. First, as shown in FIG. 3, the inner layer 2 made of a thin film tube is formed. This inner layer 2 is made of PTFE, FEP, or PF on the outer periphery of a core body 11 made of metal or the like.
It is formed by covering with a fluororesin such as A by extrusion molding. Its thickness is 0.03 mm to 0.2 mm. Through this process, a product with stable dimensions such as its inner diameter, wall thickness, and outer shape can be obtained.

Next, the outer surface of the inner layer 2 is subjected to polishing etching and chemical etching as shown in FIGS. 4 and 6. Polishing etching is performed by using a die 12 for regulating the inner diameter with a machined inner surface of about #200 to #1000, and rotating the die 12 at a high speed of 500 to 5000 revolutions/min, and polishing the inner layer 2 at a speed of 5 to 10 m/min. Let it pass. As a result, the outer diameter of the inner layer 2 becomes constant, the wall thickness can be reduced, and the surface is ground and roughened. The chemical etching process can be performed by immersing the substrate in a tank 13 of an etching solution in which a complex of sodium and ammonia is dissolved or a complex of sodium and naphthalene in tetrahydrofuran. This chemical etching treatment further promotes roughening of the outer surface of the inner layer 2. Fluororesin generally has poor adhesion with other resins, and even if a thermoplastic resin is laminated on top of it, sufficient adhesive strength cannot be exerted between the two layers. By,
By solving these drawbacks, when the thermoplastic resin is laminated on the inner layer 2, it is possible to exhibit sufficient adhesive strength and prevent peeling between the layers. Note that the appropriate immersion time in the etching solution is about 10 to 60 seconds. Furthermore, the etching process does not necessarily have to be carried out in two steps: polishing etching and chemical etching; in short, when the thermoplastic resin is laminated,
It is sufficient that the surface is roughened to the extent that sufficient adhesion is exhibited, and as long as the surface can be roughened to the necessary degree, only one of polishing etching or chemical etching may be performed.

Inner layer 2 etched in this way
As shown in FIG. 7, a urethane resin layer 4 such as molten urethane resin, which constitutes the main body portion of the outer layer 3, is laminated by an extrusion molding machine 16 on the outer periphery of the inner layer 2, which is fed out from the feed rollers 15, 15'. let Here, the outer surface of the inner layer 2 is etched to significantly increase its surface area and to activate the surface, so through this extrusion molding, both layers are completely adhered and integrated. become. Note that this urethane resin layer 4 must be covered with a net 5 in the subsequent process and then embedded in the urethane resin layer 4, so this urethane resin layer 4 must be used as a base layer. 4a and the covering layer 4b are formed separately. Therefore, this step is a step of forming the base layer 4a which is directly laminated on the inner layer 2.

The inner layer 2 and base layer 4a thus formed
As shown in FIG. 8, the flexible tubular body 17 made of laminated resin attached to the core material 11 is further covered with a net 5 made of knitted metal fibers around its outer periphery. This net 5
As is clear from the figure, the sheathing is done by the net braiding machine 18.
and positioning ring 19, the metal fibers are braided while feeding the flexible tubular body 17 in the direction shown by the arrow in the figure. By covering the net 5 in this manner, shape retention ability is imparted. After covering this net 5,
Further, a coating layer 4b covering the net 5 is formed. This coating layer 4b is made of the same material as the base layer 4a, that is, urethane resin, and is coated with this resin by means of dipping or the like using a dipping device 20, as shown in FIG. As a result, the base layer 4a and the covering layer 4b are integrated to form an outer layer 3 in which the net 5 is completely embedded in the urethane resin layer 4. Here, the urethane resin is net 5
It must be thick enough to completely cover the tube body 1, but also not create resistance when the tube body 1 is bent.
In order to prevent distortion and the like from occurring, a material with low hardness and excellent mold resistance, such as 80° polyurethane resin, is used. Moreover, the composition of the dipping solution using this urethane resin is preferably one in which the urethane resin is dissolved at 5 to 40 wt % in a tetrahydrofuran solution, for example. Furthermore, after laminating the coating layer 4b, the tube body 1 is manufactured by drying it with the dryer 21. After passing through the above steps, the tube body 1 is cut into desired dimensions and the core body 11 is removed, thereby making it possible to obtain a flexible tube constituting a forceps channel of an endoscope.

The tube body 1 manufactured in this manner has a stable thickness and outer diameter by polishing the outer circumferential surface of the inner layer 2. Furthermore, by adding a chemical etching treatment to this polishing etching treatment, the outer surface area is increased, so that the adhesive strength can be improved. Furthermore, the thickness of the extruded outer layer 3 can be easily controlled, resulting in a tube with the flexibility and stable dimensions required for the endoscope. Since the inner surface of the inner layer 2 is smooth, airtightness, watertightness, slipperiness, chemical resistance, and cleaning and disinfecting properties can be obtained. Further, by providing the reinforcing layer made of the net 5, the durability against crushing of the tube body 1 can be improved without impairing the flexibility.

[0019]

[Effects of the Invention] As explained above, the present invention provides a flexible tube body consisting of an inner layer made of a crystalline polymer resin and an outer layer made of a thermoplastic resin with a net made of hard metal fibers. Since the tube is configured, when used as a treatment instrument insertion channel, it is easy to insert the treatment instrument, etc., and the outer layer of the net improves shape retention ability, preventing defects such as deformation and kinking. Becomes durable. Even if the inner diameter of the tube becomes larger, the net greatly contributes to maintaining its shape. Therefore, the inner layer is made non-porous without increasing the thickness of the tube, making it extremely easy to clean, and reducing the wall thickness of the tube. can be made thin,
The outer diameter can be made thinner. In addition, in order to manufacture a flexible tube in which an inner layer made of a thin-walled tube made of crystalline polymer resin is laminated with an outer layer made of thermoplastic resin and having a predetermined thickness and a net embedded therein, the outer layer of the inner layer is laminated. The surface was etched and an outer layer of thermoplastic resin was laminated on the outer surface of the inner layer by extrusion molding, so a thin-walled tube made of crystalline polymer resin, which is not compatible with other resins, was used as the inner layer. The outer layer made of thermoplastic resin can be reliably laminated between both layers, and there will be no separation between the layers, so even when used as a flexible tube for guiding an endoscopic treatment tool, it will not be difficult to machine. It is possible to provide products that have improved physical strength and are hygienically safe.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of the configuration of a flexible tube showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II' in FIG. 1;

FIG. 3 is a half-sectional view showing an inner layer forming step in the flexible tube manufacturing process.

FIG. 4 is a process explanatory diagram of a surface roughening process.

FIG. 5 is a process explanatory diagram of a coating layer forming step of the urethane resin layer.

FIG. 6 is a schematic diagram of a main part of polishing treatment of a urethane resin layer.

FIG. 7 is an explanatory diagram of a step of forming a base layer of the urethane resin layer.

FIG. 8 is an explanatory diagram of a net forming process.

[Explanation of symbols]

1 Flexible tube 2 Inner layer 3 Outer layer 4 Thermoplastic resin layer 4a Base layer 4b Coating layer 5　Net 12 Dice 13 Tank 16 Extrusion molding machine 17 Flexible tube 18 Net braiding machine 19 Positioning ring 20 Dipping device 21 Drying device

Claims (7)

[Claims] Claim 1: An inner tube made of polymer resin;
In a flexible tube formed by integrating the inner layer tube and the outer layer tube by providing an outer layer tube with a reinforcing layer embedded in the outer periphery of the inner layer tube, the inner layer tube is made of crystalline polymer resin and has a predetermined outer diameter and wall thickness. , the outer circumferential surface of which is roughened, the outer tube is coated with an inner and outer thermoplastic resin of the reinforcing layer, the inner thermoplastic resin layer is coated on the roughened outer circumference of the inner tube, and the inner tube and the inner thermoplastic resin layer are coated with a reinforcing layer. A flexible tube characterized by an integrated outer layer tube. 2. The flexible tube according to claim 1, wherein the reinforcing layer is a net made of braided metal fibers. 3. The flexible tube according to claim 1, wherein the thermoplastic resin is a urethane resin. Claim 4: An inner tube made of polymer resin;
In a method for manufacturing a flexible tube in which a reinforcing layer is embedded in the outer circumference of an inner tube and an outer layer tube is provided, and the inner tube and the outer tube are integrated, a predetermined outer diameter and wall thickness are formed by extrusion molding using a crystalline polymer resin. a roughening process to roughen the outer peripheral surface of the inner tube, and an inner layer of the outer tube is formed with thermoplastic urethane resin on the outer periphery of the roughened inner tube. A method for manufacturing a flexible tube, characterized by a lamination step of integrating the inner surface of the layer and the roughened surface, and integrating an inner layer tube and an outer layer tube. 5. In the surface roughening step, the inner tube is
5. The method of manufacturing a flexible tube according to claim 4, wherein the polishing etching is performed by inserting the tube into a die having a predetermined rough surface and inner diameter at a predetermined speed and rotating the die at a predetermined rotation speed. 6. The surface roughening step is chemical etching performed by immersion in an etching solution in which a complex of sodium and ammonia is dissolved or an etching solution in which a complex of sodium and naphthalene is dissolved in tetrahydrofuran. 5. The method for manufacturing a flexible tube according to claim 4. 7. The method of manufacturing a flexible tube according to claim 4, wherein the surface roughening step is performed by polishing etching using a die and then chemical etching using an etching solution.