Flexible tube for endoscope, endoscope-type medical device, and manufacturing method thereof

Abstract

Provided are: a flexible tube which is for an endoscope and has excellent resilience, and in which the adhesiveness between a flexible tube substrate and a polymer coating layer covering the flexible tube substrate can be sufficiently maintained even when repeatedly exposed to heat for a long period of time, and deterioration in the adhesiveness between the flexible tube substrate and the polymer coating layer is less likely to occur even when repeatedly subjected to disinfection treatment using a hydrogen peroxide solution; an endoscope-type medical instrument comprising the same; and manufacturing methods therefor.　This flexible tube for an endoscope comprises: a flexible tube substrate containing metal as a constituent material; a siloxane compound-containing layer provided on the flexible tube substrate; a primer layer provided on the siloxane compound-containing layer; and a polymer coating layer provided on the primer layer, wherein the siloxane compound has a hydroxy group, and the polymer coating layer contains at least one compound among polyamide, polyester, polyurethane, and polyolefin on the primer layer-contacting side.

Description

Technical Field

[0001] The present invention relates to a flexible tube for an endoscope, an endoscope-type medical device, and a method for manufacturing these.

Background Art

[0002] An endoscope is a medical device for observing a patient's body cavity, digestive tract, esophagus, etc. Since it is inserted into the body, it is desired that it does not damage the organs and does not cause pain or discomfort to the patient. Due to such requirements, a spiral tube formed by spirally winding a soft metal strip for bending is adopted for the flexible tube constituting the insertion portion (structural portion inserted into the body cavity) of the endoscope. Further, the periphery of the spiral tube is coated with a flexible polymer, and this polymer coating layer is coated with a top coat layer as necessary, so that it does not cause irritation or damage to the inner surface of the esophagus, digestive tract, body cavity, etc.

[0003] For this flexible tube, high resilience is required in order to move smoothly in the body. By increasing the resilience of the flexible tube, the flexible tube that has passed through the bent portion in the body is likely to return to a straight shape, and the burden on the subject during the examination can be further reduced. As a technique that meets such requirements, for example, in Patent Document 1, after applying a primer to the surface of a metal core material (flexible tube base material), an outer skin layer is coated and molded, and as this primer, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, and a zirconium coupling agent can be used. According to Patent Document 1, this flexible tube for an endoscope is said to be excellent in resilience.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] On the other hand, in order to improve the operability, durability, etc. of the endoscope, it is important to enhance the adhesion between the flexible tube base material and the polymer coating layer covering it. If this adhesion is insufficient, when the flexible tube is inserted into the body, wrinkles, bulges, cracks, peeling, etc. are likely to occur in the polymer coating layer due to the bending of the flexible tube. Also, when the flexible tube is rotated in the inserted state, the polymer coating layer is likely to be twisted. If wrinkles, bulges, cracks, peeling, or twisting occur in the polymer coating layer, the surface of the flexible tube inserted into the body may catch on the surrounding tissues, which may cause pain to the subject.

[0006] Each time the endoscope is used, it is repeatedly exposed to heat generated from the light source of the illumination built into the endoscope. Also, each time the endoscope is used, it is subjected to disinfection treatment or sterilization treatment using a chemical solution, and thus is repeatedly exposed to heat of about 60°C. As a result of investigations by the present inventors, it has been found that the flexible tube for endoscope described in Patent Document 1 above tends to have a decrease in the above-mentioned adhesion when repeatedly exposed to heat. Therefore, the flexible tube for endoscope is required to have excellent heat durability over a long period (a characteristic in which the above-mentioned adhesion is not easily decreased even when repeatedly exposed to heat). Also, it has been found that the flexible tube for endoscope described in Patent Document 1 above also tends to have a decrease in the above-mentioned adhesion when repeatedly subjected to disinfection treatment using hydrogen peroxide water having a strong oxidizing power. This is considered to be due to hydrogen peroxide oxidatively decomposing the primer component, and particularly due to the activation of hydrogen peroxide by the surface of the metal base material.

[0007] Therefore, an object of the present invention is to provide a flexible tube for endoscope that is excellent in resilience, can sufficiently maintain the adhesion between the flexible tube base material and the polymer coating layer covering it even when repeatedly exposed to heat over a long period, and is less likely to cause a decrease in the adhesion between the flexible tube base material and the polymer coating layer even when repeatedly subjected to disinfection treatment using hydrogen peroxide water, and an endoscope-type medical device equipped with this flexible tube for endoscope. Another object of the present invention is to provide a method for manufacturing the above-mentioned flexible tube for endoscope and a method for manufacturing the above-mentioned endoscope-type medical device.

Means for Solving the Problems

[0008] In view of the above problems, the present inventors have repeatedly studied the formation of a polymer coating layer on a flexible tube for an endoscope. As a result, a layer is formed on the surface of a flexible tube base material made of a metal material using a siloxane compound having a hydroxy group, a primer layer is formed on this siloxane compound-containing layer, and further, by applying a specific type of polymer as a constituent material of the polymer coating layer in contact with this primer layer, it has been found that the above problems can be solved. The present invention has been further studied and completed based on these findings.

[0009] The above problems of the present invention have been solved by the following means. <1> A flexible tube base material made of metal as a constituent material, a siloxane compound-containing layer on the flexible tube base material, a primer layer on the siloxane compound-containing layer, and a polymer coating layer on the primer layer, the siloxane compound has a hydroxy group, the polymer coating layer contains at least one compound of polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer, a flexible tube for an endoscope. <2> The flexible tube for an endoscope according to <1>, wherein the siloxane compound contains an organosiloxane compound. <3> The flexible tube for an endoscope according to <1> or <2>, wherein the primer layer contains at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent. <4> The flexible tube for an endoscope according to any one of <1> to <3>, wherein the primer layer contains a silane coupling agent. <5> The flexible tube for an endoscope according to any one of <1> to <4>, wherein the primer layer contains an aminosilane coupling agent. <6> The flexible tube for an endoscope according to any one of <1> to <5>, wherein the metal constituting the flexible tube base material is stainless steel. <7> The endoscope flexible tube according to any one of <1> to <6>, wherein the metal constituting the flexible tube base material has a passive film on its surface. <8> The endoscope flexible tube according to any one of <1> to <7>, wherein the polymer coating layer has a single-layer structure or a multi-layer structure, and at least one compound of polyamide, polyester, polyurethane, and polyolefin is contained in the layer in contact with the primer layer. <9> The endoscope flexible tube according to any one of <1> to <8>, wherein the polymer coating layer has a two-layer structure, and the ratio of the thickness of the inner layer and the outer layer of the two-layer structure changes inclinedly in the axial direction of the flexible tube base material. <10> The endoscope flexible tube according to any one of <1> to <9>, wherein the ratio of the thickness of the inner layer and the outer layer is inner layer: outer layer = 95:5 to 60:40 at one end of the endoscope flexible tube, and inner layer: outer layer = 5:95 to 40:60 at the other end. <11> An endoscopic medical device having the endoscope flexible tube according to any one of <1> to <10>. <12> A method for manufacturing an endoscope flexible tube, comprising providing a siloxane compound-containing layer on a flexible tube base material made of metal as a constituent material, providing a primer layer on the siloxane compound-containing layer, and providing a polymer coating layer on the primer layer. The siloxane compound has a hydroxy group. A method for manufacturing an endoscope flexible tube, wherein the polymer coating layer contains at least one compound of polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer. <13> A method for manufacturing an endoscopic medical device, comprising incorporating the endoscope flexible tube obtained by the method for manufacturing an endoscope flexible tube according to <12> into an insertion portion of the endoscopic medical device. <14> A method for manufacturing an endoscopic medical device, comprising incorporating the endoscope flexible tube according to any one of <1> to <10> into an insertion portion of the endoscopic medical device.

[0010] In this specification, when there are a plurality of substituents, linking groups, etc. (hereinafter referred to as substituents, etc.) indicated by specific codes, or when a plurality of substituents, etc. are defined simultaneously or alternatively, it means that each of the substituents, etc. may be the same as or different from one another. Also, even if not particularly specified, when a plurality of substituents, etc. are adjacent, it means that they may be linked or fused to each other to form a ring. Regarding substituents (the same applies to linking groups) not specified as substituted or unsubstituted in this specification, within the range where the desired effect can be achieved, it means that the group may have any substituent. This is also synonymous for compounds not specified as substituted or unsubstituted. In this specification, when defining the number of carbon atoms of a certain group, this number of carbon atoms means the total number of carbon atoms of the entire group. That is, when this group is in a form having further substituents, it means the total number of carbon atoms including this substituent.

Advantages of the Invention

[0011] The flexible tube for an endoscope of the present invention is excellent in elastic resilience, and can sufficiently maintain the adhesion between the flexible tube base material and the polymer coating layer covering it even when repeatedly exposed to heat over a long period. Also, even when repeatedly subjected to a disinfection treatment using hydrogen peroxide water, a decrease in the adhesion between the flexible tube base material and the polymer coating layer is less likely to occur. In the endoscopic medical device of the present invention, the flexible tube, which is a structural part inserted into the body, is excellent in elastic resilience, and can sufficiently maintain the adhesion between the flexible tube base material and the polymer coating layer covering it even when repeatedly exposed to heat over a long period. Also, even when repeatedly subjected to a disinfection treatment using hydrogen peroxide water, a decrease in the adhesion between the flexible tube base material and the polymer coating layer is less likely to occur. Therefore, the endoscopic medical device of the present invention is excellent in durability and can further reduce the burden on the subject during use. According to the method for manufacturing a flexible tube for an endoscope of the present invention, it has excellent elastic resilience and can sufficiently maintain the adhesion between the flexible tube base material and the polymer coating layer covering it even when repeatedly exposed to heat over a long period. Also, it is possible to obtain a flexible tube for an endoscope in which the adhesion between the flexible tube base material and the polymer coating layer is less likely to decrease even when repeatedly subjected to a disinfection treatment using hydrogen peroxide water. According to the method for manufacturing an endoscope-type medical device of the present invention, the flexible tube constituting this device can have excellent elastic resilience and can sufficiently maintain the adhesion between the flexible tube base material and the polymer coating layer covering it even when repeatedly exposed to heat over a long period. Also, it can be made such that the adhesion between the flexible tube base material and the polymer coating layer is less likely to decrease even when repeatedly subjected to a disinfection treatment using hydrogen peroxide water. Therefore, by the method for manufacturing an endoscope-type medical device of the present invention, it is possible to obtain an endoscope-type medical device with excellent durability and a reduced burden on the subject during use.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0013] A preferred embodiment of an endoscopic medical device incorporating a flexible tube for an endoscope (hereinafter, the flexible tube for an endoscope may be simply referred to as a "flexible tube") will be described by taking an electronic endoscope as an example. An electronic endoscope is used as a medical device for inserting a flexible tube into a body cavity, digestive tract, esophagus, etc. to observe the inside of the body. In the example shown in FIG. 1, the electronic endoscope 2 includes an insertion portion 3 inserted into the body, a main body operation portion 5 connected to the proximal end portion of the insertion portion 3, and a universal cord 6 connected to a processor device and a light source device. The insertion portion 3 is composed of a flexible tube 3a connected to the main body operation portion 5, an angle portion 3b connected thereto, and a distal end portion 3c connected to the tip thereof and having a built-in imaging device (not shown) for photographing inside the body. The flexible tube 3a, which occupies most of the length of the insertion portion 3, has flexibility over almost its entire length, and particularly the portion inserted into the inside of a body cavity or the like has a more flexible structure. In FIG. 1, the angle portion 3b side has a soft structure (soft), and the main body operation portion 5 side has a hard structure (hard).

[0014] [Flexible tube for endoscope] The flexible tube for an endoscope of the present invention has a flexible tube base material made of a metal as a constituent material, a siloxane compound-containing layer on the flexible tube base material, a primer layer on the siloxane compound-containing layer, and a polymer coating layer on the primer layer. The above siloxane compound has at least one of a hydrolyzable group and a hydroxy group. Further, the polymer coating layer contains at least one compound of polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer. That is, the flexible tube for an endoscope has, in this order, a flexible tube base material made of a metal as a constituent material, a siloxane compound-containing layer, a primer layer, and a polymer coating layer, the siloxane compound has a hydroxy group, and the polymer coating layer contains at least one compound of polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer. In addition, in FIG. 2, the siloxane compound-containing layer and the primer layer are not shown.

[0015] The flexible tube for an endoscope of the present invention is excellent in elastic resilience and can sufficiently maintain the adhesion between the flexible tube base material and the polymer coating layer covering it even when repeatedly exposed to heat over a long period of time. Also, even when repeatedly subjected to a disinfection treatment using hydrogen peroxide water, a decrease in the adhesion between the flexible tube base material and the polymer coating layer is unlikely to occur. The reason for this is not clear, but it is presumed to be due to the fact that the siloxane compound-containing layer itself exhibits high resistance to hydrogen peroxide and the number of covalent bonds (for example, ether bonds) between the primer layer and the flexible tube base material layer increases.

[0016] <Flexible tube base material> The flexible tube has, as the innermost layer, a flexible tube base material made of metal as a constituent material. As shown in FIG. 2, the flexible tube base material 14 is preferably in a form in which a cylindrical net body 12 formed by braiding metal wires is coated on a spiral tube 11 formed by spirally winding a metal strip piece 11a on the innermost side, and caps 13 are respectively fitted to both ends. The metal constituting the flexible tube base material 14 is preferably subjected to a passivation treatment on its surface in order to prevent corrosion. That is, the flexible tube base material 14 preferably has a passivation film (for example, a metal oxide film) on its outer periphery. This passivation treatment can be performed by a conventional method. For example, a passivation film can be formed on the metal surface by immersing it in a solution containing a strong oxidizing agent such as nitric acid, heating it in air (oxygen) or water (water vapor), or anodizing it in a solution containing an oxidizing agent. The metal constituting the flexible tube base material 14 is preferably stainless steel. The surface of stainless steel is usually in a state where chromium and oxygen are bonded to form a passivation film. However, even when stainless steel is used as the constituent material of the flexible tube base material 14, it is preferable to subject the stainless steel to the above-described passivation treatment in order to more surely form a more uniform passivation film on the entire surface of the stainless steel.

[0017] <Siloxane compound-containing layer> The siloxane compound contained in the siloxane compound-containing layer is a compound having a siloxane bond (repeating structure of [-Si-O]), and is, for example, an oligomer or polymer obtained by hydrolyzing and polycondensing silane compounds having a hydrolyzable group. Therefore, the siloxane compound has a hydroxy group. The silane compound may be either an inorganic silane compound or an organic silane compound, and an organic silane compound is preferred. That is, the siloxane compound is preferably an organic siloxane compound.

[0018] Examples of the hydrolyzable group include an alkoxy group (alkyloxy group), an alkenyloxy group, an acyloxy group, an aminooxy group, an oxime group, and an amide group, and an alkoxy group is preferred.

[0019] The alkyl group in the alkoxy group may be linear, branched, or cyclic. The number of carbon atoms of this alkyl group is preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 10, and still more preferably 1 or 2. Specific examples of the alkyl group include methyl, ethyl, isopropyl, butyl, and cyclopentyl.

[0020] The alkenyl group in the alkenyloxy group may be linear, branched, or cyclic. The number of carbon atoms of this alkenyl group is preferably 2 to 30, more preferably 2 to 20, and still more preferably 2 to 10.

[0021] Examples of the organic silane compound include tetraalkoxysilane compounds, trialkoxysilane compounds, and dialkoxysilane compounds. The above tetraalkoxysilane is not particularly limited, and examples thereof include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, and the like. The trialkoxysilane compound is not particularly limited, and examples thereof include methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and the like. The dialkoxysilane compound is not particularly limited, and examples thereof include dimethyldimethoxysilane, dimethyldiethoxysilane, and the like.

[0022] The siloxane compound preferably has no organic groups other than methyl and ethyl.

[0023] The weight average molecular weight of the siloxane compound is not particularly limited. For example, it is preferably from 100 to 2000, more preferably from 150 to 500.

[0024] The weight average molecular weight or number average molecular weight of the compounds described in the present specification is determined as follows. The weight average molecular weight or number average molecular weight can be measured as the molecular weight in terms of polystyrene by gel permeation chromatography (GPC). Specifically, using a GPC apparatus HLC-8220 (trade name, manufactured by Tosoh Corporation), tetrahydrofuran as the eluent, columns G3000HXL + G2000HXL (both trade names, manufactured by Tosoh Corporation), at 23 °C with a flow rate of 1 mL / min, detection can be performed with RI.

[0025] Examples of the siloxane compound that can be used in the present invention include the compounds used in the examples described below, but the present invention is not limited thereto.

[0026] The flexible tube of the present invention means that the siloxane compound-containing layer includes a form in which it reacts with at least one of the flexible tube base material and the primer layer. For example, in the siloxane compound-containing layer, the hydroxy group of the siloxane compound may react with the constituent metal of the primer layer or the flexible tube base material, or may react with the groups on the surface of the polymer coating layer.

[0027] The content of the siloxane compound in the siloxane compound-containing layer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and even more preferably 90% by mass or more. The siloxane compound-containing layer may be a layer composed of the siloxane compound. In the siloxane compound contained in the siloxane compound-containing layer, the content of the organosiloxane is not particularly limited, and for example, it can be 80% by mass or more, preferably 90% by mass or more, and may be 100% by mass. The siloxane compound-containing layer may contain components other than the siloxane compound as long as the effects of the present invention are not impaired. Examples of such components include metal alkoxides other than the coupling agents described later, binder resins, and stabilizers (surfactants and antioxidants).

[0028] The average layer thickness of the siloxane compound-containing layer is not particularly limited. From the viewpoints of the elastic resilience, heat durability, and hydrogen peroxide water resistance of the flexible tube, 5 to 400 nm is preferable, 15 to 300 nm is more preferable, 25 to 150 nm is more preferable, and 40 to 100 nm is still more preferable.

[0029] <Primer layer> The primer layer constituting the flexible tube of the present invention preferably contains at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent from the viewpoints of the elastic resilience, heat durability, and hydrogen peroxide water resistance of the flexible tube. In addition, the silane coupling agent preferably does not have a siloxane bond, and preferably has an organic group other than methyl, ethyl, methoxy, and ethoxy (for example, a vinyl group, a propyl group, an acid anhydride group, an epoxy group). As the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent used in the present invention, ordinary silane coupling agents applicable to the primer layer of the flexible tube for endoscopes can be widely employed. In the present invention, from the viewpoints of the resilience, heat durability, and hydrogen peroxide resistance of the flexible tube, it is preferable that the primer layer contains a silane coupling agent, and more preferably contains an aminosilane coupling agent (preferably a silane coupling agent having at least one of an unsubstituted amino group and a monosubstituted amino group). Specific examples of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent include the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent used in the following examples, but the present invention is not limited thereto. The total content of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent in the primer layer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and even more preferably 90% by mass or more. Further, the primer layer may be a layer composed of at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent.

[0030] The molecular weight of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent used in the present invention is not particularly limited. For example, it is preferably 100 to 2000, and more preferably 200 to 500. In addition, a polymer silane coupling agent can also be used.

[0031] When the primer layer contains an aminosilane coupling agent, the content of the aminosilane coupling agent in the silane coupling agent constituting the primer layer is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and even more preferably 90% by mass or more. The above primer layer may contain components other than silane coupling agents, titanium coupling agents, zirconium coupling agents, and aluminum coupling agents, as long as the effects of the present invention are not impaired. Examples of such components include metal alkoxides other than the above coupling agents, binder resins, surfactants, and stabilizers such as antioxidants.

[0032] In the present invention, "the primer layer contains at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent" means that at least one of the silane coupling agent, the titanium coupling agent, the zirconium coupling agent, and the aluminum coupling agent is contained in a state of being reacted with the siloxane compound-containing layer or the flexible pipe base material, and a form in which at least one of the silane coupling agent, the titanium coupling agent, the zirconium coupling agent, and the aluminum coupling agent is contained in a state of being reacted with the polymer coating layer. That is, at least a part of the silane coupling agent, the titanium coupling agent, the zirconium coupling agent, and the aluminum coupling agent is hydrolyzed to expose a hydroxy group, and this can react with the constituent metal of the siloxane compound-containing layer or the flexible pipe base material, or react with the group on the surface of the polymer coating layer and exist.

[0033] The layer thickness of the above primer layer is significantly thinner than that of a normal adhesive layer (in other words, the concept of thickness cannot be imagined). That is, the primer layer is different from the adhesive layer that requires a certain layer thickness and softness for the adhesion between the flexible pipe base material and the polymer coating layer.

[0034] <Polymer coating layer> The flexible pipe of the present invention has a polymer coating layer on the outer periphery of a flexible pipe base material provided with a siloxane compound-containing layer and a primer layer in this order. In the form of FIG. 2, the outer surface of the polymer coating layer 15 is coated with a topcoat layer 16 containing fluorine or the like, which contributes to chemical resistance and the like. In FIG. 2, only one layer of the spiral tube 11 is shown, but two or more layers may be coaxially stacked. In the drawing, the polymer coating layer 15 and the topcoat layer 16 are drawn thicker than the diameter of the flexible tube base material 14 in order to clearly show the layer structure.

[0035] In the present invention, the polymer coating layer covers the outer peripheral surface of the flexible tube base material having the above-described siloxane compound-containing layer and primer layer. In the form of FIG. 2, the polymer coating layer 15 has a two-layer structure in which an inner layer 17 covering the entire circumferential surface around the axis of the flexible tube base material 14 and an outer layer 18 covering the entire circumferential surface around the axis of the inner layer 17 are laminated. Usually, a soft polymer is used for the material of the inner layer 17, and a hard polymer is used for the material of the outer layer 18, but the present invention is not limited to these forms. In the present invention, as will be described later, when the polymer coating layer has a multi-layer structure of two or more layers, at least one kind of compound among polyamide, polyester, polyurethane, and polyolefin is contained in at least the innermost layer (the layer in contact with the primer layer). Further, when the polymer coating layer is a single layer in the present invention, this single-layer polymer coating layer contains at least one kind of compound among polyamide, polyester, polyurethane, and polyolefin. That is, in the present invention, the polymer coating layer preferably contains at least one kind of compound among polyamide, polyester, polyurethane, and polyolefin on at least the side in contact with the primer layer, and at least one kind of compound among polyamide, polyester, and polyurethane on the side in contact with the primer layer.

[0036] (Polyamide) As the polyamide, ordinary polyamides applicable as the polymer coating layer of the flexible tube for endoscopes can be widely adopted. For example, crystalline polyamide, amorphous polyamide, and polyamide elastomer can be mentioned. There is no particular limitation on the crystalline polyamide, and for example, aliphatic polyamide and aromatic polyamide can be mentioned. Examples of aliphatic polyamides include poly ε-caproamide (polyamide 6), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), polycaproamide / polyhexamethylene adipamide copolymer (polyamide 6 / 66), polyundecamide (polyamide 11), polycaproamide / polyundecamide copolymer (polyamide 6 / 11), polydodecamide (polyamide 12), polycaproamide / polydodecamide copolymer (polyamide 6 / 12), polyhexamethylene sebacamide (polyamide 610), polydecamethylene sebacamide (polyamide 1010), polyhexamethylene dodecamide (polyamide 612), polydecamethylene dodecamide (polyamide 1012), polyundecamethylene adipamide (polyamide 116), and mixtures or copolymers thereof.

[0037] Examples of aromatic polyamides include polyhexamethylene isophthalamide (polyamide 6I), polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polycaproamide / polyhexamethylene terephthalamide copolymer (polyamide 6 / 6T), polycaproamide / polyhexamethylene isophthalamide copolymer (polyamide 6 / 6I), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (polyamide 66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I), polytrimethylhexamethylene terephthalamide (polyamide TMDT), polybis(4-aminocyclohexyl)methane dodecamide (polyamide PACM12), polybis(3-methyl-4-aminocyclohexyl)methane dodecamide (nylon dimethyl PACM12), polymetaxylylene adipamide (polyamide MXD6), polydecamethylene terephthalamide (polyamide 10T), polyundecamethylene terephthalamide (polyamide 11T), and mixtures or copolymers thereof.

[0038] Examples of the amorphous polyamide include polycondensates of isophthalic acid / terephthalic acid / 1,6-hexanediamine / bis(3-methyl-4-aminocyclohexyl)methane, polycondensates of terephthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine, polycondensates of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam, polycondensates of isophthalic acid / terephthalic acid / 1,6-hexanediamine, polycondensates of isophthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine, polycondensates of isophthalic acid / terephthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine, polycondensates of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam, polycondensates of isophthalic acid / terephthalic acid / other diamine components, and the like.

[0039] Examples of the polyamide elastomer include elastomers called amide-based thermoplastic elastomers, in which the hard segment is polyamide. For example, multi-block copolymers in which the hard segment is polyamide and the soft segment is polyethylene glycol, poly(oxytetramethylene) glycol, poly(oxypropylene) glycol, etc., and multi-block copolymers in which the hard segment is polyamide and the soft segment has both ether bond and ester bond connection modes can be mentioned. Examples of the hard segment include polyamide 6, 66, 610, 11, 12, etc. Examples of the polyether in the soft segment include polyethylene glycol, diol poly(oxytetramethylene) glycol, poly(oxypropylene) glycol, etc., and examples of the polyester include poly(ethylene adipate) glycol, poly(butylene-1,4-adipate) glycol, etc.

[0040] Examples of commercially available polyamides that can be used in the present invention include polyamide 11 (manufactured by Arkema, trade name "Rilsan BMN O"), polyamide 12 (manufactured by Daicel - Evonik, trade name "Diamide L1940"), polyamide 1010 (manufactured by Daicel - Evonik, trade name "Vestamid TerraDS16"), polyamide 1012 (manufactured by Evonik, trade name "Vestamid TerraDD16"), amorphous polyamide (manufactured by Daicel - Evonik, trade name "Trogamid CX7323"), and polyamide elastomers (manufactured by Arkema, trade names "Pebax 4533", "Pebax 7233", and "Pebax Rnew80R53").

[0041] The polyamide may be used alone or in combination of two or more kinds.

[0042] (Polyester) As the polyester, ordinary polyesters applicable as the polymer coating layer of the flexible tube for endoscopes can be widely adopted. For example, thermoplastic polyesters and polyester elastomers can be mentioned. The thermoplastic polyester includes polyester resins composed of a dicarboxylic acid component and a diol component, polyester resins composed of a hydroxycarboxylic acid component, and the like. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, 2,6 - naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 5 - sodium sulfoisophthalic acid, oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, dimer acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, cyclohexanedicarboxylic acid, and the like.

[0043] In addition, examples of the diol component include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanedimethanol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, ethylene oxide adducts of bisphenol A and bisphenol S, and the like.

[0044] Examples of the hydroxycarboxylic acid component include ε-caprolactone, lactic acid, 4-hydroxybenzoic acid, and the like.

[0045] The thermoplastic polyester resin may be a homopolymer composed of the above dicarboxylic acid component and diol component, or a homopolymer composed of the above hydroxycarboxylic acid component, or a copolymer. Furthermore, it may contain a small amount of trifunctional compound components such as trimellitic acid, trimesic acid, pyromellitic acid, trimethylolpropane, glycerin, pentaerythritol, and the like.

[0046] Examples of the polyester elastomer include, for example, an elastomer called an ester-based thermoplastic elastomer in which the hard segment is polyester. For example, a multiblock copolymer in which the hard segment is a crystalline polyester and the soft segment is a polyether or polyester, and a multiblock copolymer in which the hard segment is a crystalline polyester and the soft segment has both a bonding mode of an ether bond and an ester bond can be mentioned. Examples of the hard segment include polybutylene terephthalate and polyethylene terephthalate. Examples of the soft segment include polyalkylene glycols such as polytetramethylene glycol and polypropylene glycol, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, and polyesters such as polycaprolactone. As the polyester elastomer, for example, a block copolymer composed of a high melting point polyester segment (hard segment) and a low melting point polymer segment (soft segment) with a molecular weight of 400 to 6,000 as described in, for example, Japanese Patent Laid-Open No. 11-92636 can be used.

[0047] Commercially available polyesters used in the present invention include, for example, polyester elastomers (trade names "Pelprene P-40B", "Pelprene P-70B", and "Pelprene S-3001" manufactured by Toyobo Co., Ltd., and trade name "Primalloy B1942" manufactured by Mitsubishi Chemical Corporation) and polybutylene terephthalate (manufactured by Mitsubishi Engineering Plastics Corporation, trade name "Novaduran 5505S").

[0048] The polyester may be used alone or in combination of two or more.

[0049] (Polyurethane) As the polyurethane, ordinary polyurethanes applicable as the polymer coating layer of the flexible tube for endoscopes can be widely adopted. For example, carbonate-based, ether-based, ester-based or mixed systems of these polyurethanes can be used. Also, polyurethane elastomers are preferable. Examples of the polyurethane elastomer include block polymers called urethane-based thermoplastic elastomers, in which the hard segment is polyurethane and the soft segment has an ether, ester or carbonate bond or a mixed form of these bonds, and can be appropriately prepared according to the purpose. For example, a block polymer containing a hard segment composed of a low molecular weight glycol component and a diisocyanate component and a soft segment composed of a high molecular weight (long chain) diol component and a diisocyanate component can be mentioned. Examples of the high molecular weight (long chain) diol component include polyether diols, polyester diols, and lactone-based polyester diols. For example, polypropylene glycol, polytetramethylene oxide, poly(1,4-butylene adipate), poly(ethylene adipate-co-1,4-butylene adipate), polycaprolactone diol, poly(1,6-hexylene carbonate), poly(1,6-hexylene adipate-co-neopentylene adipate), etc. may be mentioned. The number average molecular weight of the high molecular weight (long chain) diol is preferably 500 to 10,000. As the low molecular weight glycol component, short chain diols such as ethylene glycol, propylene glycol, 1,4-butanediol, and bisphenol A can be used. The number average molecular weight of the short chain diol is preferably 48 to 500. Examples of the above diisocyanate component include diphenylmethane diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, 1,5-naphthalene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, etc.

[0050] As for the polyurethane elastomer according to the above embodiment, for example, reference can be made to the disclosure of JP-A-2005-015643.

[0051] Examples of commercially available polyurethanes that can be used in the present invention include PANDEX T-2185, T-2983N (both manufactured by DIC Corporation), Miractoran (manufactured by Nippon Miractoran Co., Ltd.), Elastran (manufactured by BASF Japan Ltd.), Resamine (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), Pellethene (manufactured by Dow Chemical Japan), Iron Rubber (manufactured by NOK Corporation), and Mobyron (manufactured by Nisshinbo Chemical Inc.). Examples of such polyurethanes include Isoplast (manufactured by Lubrizol), Tecoflex (manufactured by Lubrizol), Superflex 830, 460, 870, 420, or 420NS (polyurethanes manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Hydran AP-40F, WLS-202, or HW-140SF (polyurethanes manufactured by DIC Corporation), Olester UD500 or UD350 (polyurethanes manufactured by Mitsui Chemicals, Inc.), and Takelac W-615, W-6010, W-6020, W-6061, W-405, W-5030, W-5661, W-512A-6, W-635, or WPB-6601 (manufactured by DIC Corporation).

[0052] The polyurethane may be used alone or in combination of two or more kinds.

[0053] (Polyolefin) As the polyolefin, a wide variety of ordinary polyolefins that can be used as the polymer coating layer of a flexible tube for an endoscope can be used, including, for example, polyolefin resins, rubber, and olefin-based elastomers.

[0054] Examples of the polyolefin resin or rubber include homopolymers or copolymers of α-olefins having 2 to 20 carbon atoms such as ethylene, propylene, 1-butene, 1-hexene, and 4-methyl-pentene. Further examples include copolymers of non-conjugated dienes having 2 to 20 carbon atoms such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, butadiene, and isoprene with α-olefins. Also, examples include ethylene-α-olefin copolymer rubber, ethylene-α-olefin-non-conjugated diene copolymer rubber, propylene-α-olefin copolymer rubber, and butene-α-olefin copolymer rubber. Further, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylate-(meth)acrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-(meth)acrylic acid copolymer, ethylene-propylene-(meth)acrylic acid copolymer, ethylene-propylene-(meth)acrylate-(meth)acrylic acid copolymer, ethylene-maleic anhydride copolymer, ethylene-(meth)acrylate-maleic anhydride copolymer, ethylene-butene-maleic anhydride copolymer, ethylene-butene-(meth)acrylic acid copolymer, ethylene-butene-maleic anhydride-(meth)acrylic acid copolymer, propylene-butene-maleic anhydride copolymer, propylene-butene-(meth)acrylic acid copolymer, propylene-butene-maleic anhydride-(meth)acrylic acid copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl chloride copolymer, and ethylene-(meth)acrylic acid copolymer, etc. can also be used.

[0055] Examples of the polyolefin in the olefin-based elastomer include ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-α-olefin copolymer, propylene-1-butene copolymer, propylene-α-olefin copolymer, 1-butene-α-olefin copolymer, propylene-1-butene-ethylene copolymer, propylene-α-olefin-ethylene copolymer, propylene-α-olefin-1-butene copolymer, 1-butene-α-olefin-ethylene copolymer, and polypropylene. Examples of the rubber component in the olefin-based elastomer include propylene rubber (PP), ethylene-propylene rubber (EPM), and ethylene-propylene-diene rubber (EPDM), polyisoprene, polybutadiene, polychloroprene, and isobutylene-isoprene copolymer. The polyolefin and the rubber component in the olefin-based elastomer may each be contained alone or in combination of two or more.

[0056] Examples of the polyolefin used in the present invention that are commercially available include "Surlyn 3145D" (trade name, manufactured by Toyobo Co., Ltd.) and Zeelas MC707 (trade name, manufactured by Mitsubishi Chemical Corporation).

[0057] The polyolefin may be used alone or in combination of two or more.

[0058] When the polymer coating layer is a single layer, the total content of the compounds selected from polyamide, polyester, polyurethane, and polyolefin in the polymer coating layer, and when the polymer coating layer is a multi-layer, the total content of the compounds selected from polyamide, polyester, polyurethane, and polyolefin in the innermost layer are each preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and even more preferably 90% by mass or more. Further, when the polymer coating layer is a single layer, the polymer coating layer may be a layer composed of at least one compound of polyamide, polyester, polyurethane, and polyolefin, and when the polymer coating layer is a multi-layer, the innermost layer may be a layer composed of at least one compound of polyamide, polyester, polyurethane, and polyolefin. When the polymer coating layer in the case of a single-layer polymer coating layer and the innermost layer in the case of a multi-layer polymer coating layer contain a polymer other than the polymers selected from polyamide, polyester, polyurethane, and polyolefin, this polymer is not particularly limited as long as the effects of the present invention are not impaired. In addition, the polymer coating layer can appropriately contain various common additives within a range that does not impair the effects of the present invention. Examples of such additives include heat stabilizers, inorganic fillers, impact improvers, plasticizers, lubricants, metal soaps, light resistance aids, and colorants. The content of the above additives in the polymer coating layer can also be adjusted as appropriate. Such additives may be derived from the polymer material used, or can be added separately from the polymer.

[0059] It is also preferable that the layers other than the innermost layer in the case of a multi-layer polymer coating layer contain at least one compound of polyamide, polyester, polyurethane, and polyolefin. These polymers can be appropriately combined to form a layer having desired physical properties.

[0060] Each of the above polymers that can be used for the polymer coating layer of the present invention preferably has a molecular weight of 10,000 to 1,000,000, more preferably 20,000 to 500,000, and particularly preferably 30,000 to 300,000. In the present invention, unless otherwise specified, the molecular weight of the polymer constituting the polymer coating layer means the weight average molecular weight. The weight average molecular weight can be measured as the molecular weight in terms of polystyrene by gel permeation chromatography (GPC).

[0061] As shown in FIG. 2, in the present invention, the polymer coating layer 15 is preferably formed with a substantially uniform thickness in the longitudinal direction (axial direction) of the flexible tube base material 14. The thickness of the polymer coating layer 15 is, for example, 0.2 mm to 1.0 mm. The outer diameter D of the flexible tube 3a is appropriately set according to the purpose. For example, it is 11 to 14 mm. In FIG. 2, the thicknesses of the inner layer 17 and the outer layer 18 are formed such that the ratio of the thicknesses of the respective layers 17 and 18 changes with respect to the total thickness of the polymer coating layer 15 in the axial direction of the flexible tube base material 14. Specifically, on the one end 14a side (tip side) of the flexible tube base material 14 attached to the angled portion 3b, the thickness of the inner layer 17 is larger than the thickness of the outer layer 18 with respect to the total thickness of the polymer coating layer 15. Then, toward the other end 14b side (base end side) attached to the main body operation portion 5 from the one end 14a, the thickness of the inner layer 17 gradually decreases, and on the other end 14b side, the thickness of the outer layer 18 is larger than the thickness of the inner layer 17.

[0062] In FIG. 2, the ratio of the thickness of the inner layer 17 at the one end 14a is the largest, and the ratio of the thickness of the outer layer 18 at the other end 14b is the largest. The thickness of the inner layer 17: the thickness of the outer layer 18 can be, for example, 9:1 at the one end 14a and, for example, 1:9 at the other end 14b. The thicknesses of both layers are changed such that the ratio of the thicknesses of the inner layer 17 and the outer layer 18 is reversed from the one end 14a to the other end 14b. Thereby, a difference in hardness occurs between the one end 14a side and the other end 14b side of the flexible tube 3a, and the flexibility can be changed in the axial direction such that the one end 14a side is soft and the other end 14b side is hard. It is preferable that the ratio of the thicknesses at one end is 95:5 to 60:40 (inner layer: outer layer), and it is preferable that the ratio of the thicknesses at the other end is 5:95 to 40:60 (inner layer: outer layer). By setting the ratio of the thicknesses of the inner layer 17 and the outer layer 18 within the range of 95:5 to 5:95, it is possible to precisely control the extrusion amount of the thinner polymer as well.

[0063] It is preferable that the difference in the 100% modulus value, which is an index representing the hardness after molding, between the soft polymer and the hard polymer used for the inner layer 17 and the outer layer 18 is 1 MPa or more, and more preferably 3 MPa or more. The difference in the melt viscosity at a molding temperature of 150°C to 300°C, which is an index representing the fluidity of the polymer in the molten state, is preferably 2500 Pa·s or less. Thereby, the polymer coating layer 15 composed of the inner layer 17 and the outer layer 18 ensures both good molding accuracy and the necessary hardness difference on the tip side and the base end side.

[0064] <Top coat layer> In the flexible tube of the present invention, a top coat layer 16 is disposed on the outer periphery of the polymer coating layer 15 if necessary. The material of the top coat layer is not particularly limited, and urethane paints, acrylic paints, fluorine paints, silicone paints, epoxy paints, polyester paints, etc. are applicable. The main purposes of using the top coat layer are to protect the surface of the flexible tube, provide a gloss finish, impart slipperiness, and impart chemical resistance. Therefore, as the top coat layer, those having a high elastic modulus, a smooth surface, and excellent chemical resistance are preferable.

[0065] [Manufacturing method of flexible tube] [Formation of siloxane compound-containing layer] Specific examples of the method for forming the siloxane compound-containing layer are shown below, but the present invention is not limited thereto.

[0066] The siloxane compound-containing layer can be formed on the outer periphery of the flexible tube base material through the following steps (i) and (ii). (i) Prepare a silica composition obtained by subjecting an alkoxysilane compound to a dehydration condensation reaction. (ii) After applying the silica composition on the flexible tube base material, dry (or heat) the silica composition to form a coating film and then heat it.

[0067] In the above step (i), a silica composition is obtained by subjecting an alkoxysilane compound to a dehydration condensation reaction in a composition containing the alkoxysilane compound, water, and an organic solvent. For example, an alkoxysilane compound, an organic solvent, and water are mixed, and if necessary, a catalyst described later is added thereto, and the resulting mixture is obtained by mixing, for example, at 40 to 120°C for 10 minutes to 8 hours. An organic solvent (preferably the same organic solvent as the above organic solvent) is added thereto, and the mixture is stirred at room temperature (for example, 25 to 30°C) for about 10 to 90 minutes to prepare a uniform solution. The solution thus obtained is diluted with an organic solvent (preferably an organic solvent different from the above organic solvent).

[0068] In the silica composition, the total content of the silane compound (silicon atom-containing compound) is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.5% by mass or more, and still more preferably 1% by mass or more. On the other hand, the total content of the above silane compound is preferably 70% by mass or less, more preferably 50% by mass or less, still more preferably 40% by mass or less, and still more preferably 20% by mass or less.

[0069] The silica composition may contain a surfactant in order to make the siloxane compound-containing layer porous.

[0070] As the organic solvent, it is preferable to use an organic solvent that can be miscible with the above-mentioned alkoxysilane compound and water. That is, a water-soluble organic solvent is preferable. For example, monohydric alcohols having 1 to 4 carbon atoms such as methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-1-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, etc., dihydric alcohols having 1 to 4 carbon atoms, polyhydric alcohols such as glycerin and pentaerythritol, etc. alcohol compounds; esters or esterified products of the above alcohol compounds such as methyl acetate, ethyl acetate, isobutyl acetate, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, 2-ethoxyethanol, propylene glycol monomethyl ether, propylene glycol methyl ether acetate; ketone compounds such as acetone and methyl ethyl ketone; amide compounds such as formamide, N-methylformamide, N-ethylformamide, N,N-dimethylformamide, N,N-diethylformamide, N-methylacetamide, N-ethylacetamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidone, N-formylmorpholine, N-acetylmorpholine, N-formylpiperidine, N-acetylpiperidine, N-formylpyrrolidine, N-acetylpyrrolidine, N,N'-diformylpiperazine, N,N'-diformylpiperazine, N,N'-diacetylpiperazine; lactone compounds such as γ-butyrolactone; ureas such as tetramethylurea and N,N'-dimethylimidazolidine; dimethyl sulfoxide and the like. Among these, in order to perform hydrolysis under more stable conditions with respect to the contained alkoxysilane compound, alcohols are preferable, and monohydric alcohols are more preferable.

[0071] The silica composition usually contains a catalyst. As the catalyst, a substance that can arbitrarily promote the hydrolysis and dehydration condensation reactions of the alkoxysilane compound can be used. Examples include acids such as hydrofluoric acid, phosphoric acid, boric acid, hydrochloric acid, nitric acid, sulfuric acid, formic acid, acetic acid, oxalic acid, maleic acid, methylmalonic acid, stearic acid, linoleic acid, benzoic acid, phthalic acid, citric acid, and succinic acid; amine compounds such as ammonia, butylamine, dibutylamine, and triethylamine; bases such as pyridine; Lewis acids such as aluminum acetylacetone complex; and the like. In addition, examples of the catalyst include metal chelate compounds. Examples of the metal species of this metal chelate compound include titanium, aluminum, zirconium, tin, antimony, and the like.

[0072] The silica composition may contain components other than the above-mentioned alkoxysilane compound, organic solvent, surfactant, water, and catalyst as long as the effects of the present invention are not impaired.

[0073] In the above step (ii), for example, a flexible tube substrate is immersed in the silica composition obtained in the above step (i), and then the flexible tube substrate is taken out and dried to form a coating film. Subsequently, heating at 80 to 400 ° C. can obtain a flexible tube substrate having a siloxane compound-containing layer.

[0074] When using a commercially available siloxane compound, a silica composition containing, for example, 0.01 to 3% by mass of the siloxane compound in the above organic solvent can be prepared, and the above step (ii) can be performed using this composition.

[0075] Before the formation of the siloxane compound-containing layer, it is preferable to degrease and wash the flexible tube substrate with an acid solution, an alkali solution, an aqueous surfactant solution, an organic solvent, or the like. Further, after the above washing, it is preferable to wash with water or warm water so that acids, alkalis, surfactants, etc. are reduced from the substrate surface.

[0076] In the present invention, as long as the effects of the present invention are not impaired, a part of the flexible tube substrate may not be covered with the siloxane compound-containing layer (that is, a part of the siloxane compound-containing layer may have voids).

[0077] <Formation of Primer Layer> In the production of the flexible tube of the present invention, after the formation of the siloxane compound-containing layer, a primer layer is formed on the siloxane compound-containing layer. The primer layer is prepared by dissolving at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent in a solvent to prepare a coating solution, and applying this coating solution to the outer periphery of the flexible tube base material by painting, spraying, or dipping the flexible tube base material into the coating solution. After forming a coating film on at least the outer periphery of the flexible tube base material, the coating film can be formed by drying it by a conventional method (for example, high-temperature drying at about 100 °C). As the solvent used in the coating solution, alcohol solvents such as methanol and ethanol, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as ethyl acetate, hydrocarbon solvents such as toluene, or a mixture thereof can be used. Further, it is preferable to mix an acid catalyst such as water or acetic acid in order to promote the hydrolysis of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent with respect to these solvents. The coating solution may be adjusted to be acidic (for example, pH 1 to 4 at 25 °C) or alkaline (for example, pH 9 to 11 at 25 °C). The content of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent in the coating solution is not particularly limited. For example, the total content can be 0.01 to 2% by mass, preferably 0.05% by mass or more and less than 1.5% by mass, and more preferably 0.1% by mass or more and less than 1.0% by mass. In addition to at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent, a solvent, and a pH adjuster, the coating solution may also contain a surfactant, a catalyst, etc. The coating solution is more preferably composed of at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent and a solvent. In the present invention, within a range that does not impair the effects of the present invention, a part of the siloxane compound-containing layer may have a portion not covered by the primer layer (that is, a part of the primer layer may have voids).

[0078] <Formation of Polymer Coating Layer> Regarding the formation of the polymer coating layer, the case where the polymer coating layer has a two-layer structure will be described as an example. A flexible tube having a two-layer structure with an inner layer and an outer layer for the polymer coating layer can be obtained, for example, by melt-kneading and extrusion molding around the flexible tube base material on which the primer layer is formed, a first polymer material (a polymer material containing at least one compound of polyamide, polyester, polyurethane, and polyolefin) constituting the inner layer and a second polymer material constituting the outer layer to coat the flexible tube base material. Note that a polymer coating layer having one layer or three or more layers can also be obtained by appropriately changing the layer configuration with reference to the following method.

[0079] An example of a method for forming the polymer coating layer of the flexible tube 3a (FIGS. 1 and 2) will be described with reference to FIGS. 3 and 4. In this embodiment, a continuous molding machine is used to mold the polymer coating layer 15. The continuous molding machine 20 preferably comprises a well-known extrusion part 21 and 22 including a hopper, screws 21a and 22a, a head part 23 for coating and molding the polymer coating layer 15 on the outer peripheral surface of the flexible tube base material 14, a cooling part 24, a transport part 25 (a supply drum 28 and a take-up drum 29) for transporting the connected flexible tube base material 31 to the head part 23, and a control part 26 for controlling these. The head part 23 preferably comprises a nipple 32, a die 33, and a support 34 for fixedly supporting them. As a configuration example of such an apparatus, for example, the apparatus described in FIGS. 3 to 5 of JP-A-2011-72391 can be used.

[0080] It is preferable to heat the inside of the die 33 to a predetermined molding temperature. The molding temperature is preferably set in the range of 150°C to 300°C. By heating and temperature-controlling the heating part in the apparatus, the temperatures of the first polymer material 39 and the second polymer material 40 can be raised. In addition, the higher the rotational speeds of the screws 21a and 22a are, the higher the temperatures of the first polymer material 39 and the second polymer material 40 can be made, and the fluidity of each can be increased. At this time, by keeping the conveyance speed of the connecting flexible tube base material 31 constant and changing the discharge amounts of the molten first polymer material 39 and the second polymer material 40, the molding thicknesses of the inner layer 17 and the outer layer 18 can be adjusted.

[0081] Regarding the process when the polymer coating layer 15 is formed on the connecting flexible tube base material 31 by the continuous molding machine 20, when the continuous molding machine 20 performs the molding process, the molten first polymer material 39 and the second polymer material 40 are extruded from the extrusion parts 21 and 22 to the head part 23. At the same time, the conveyance part 25 operates and the connecting flexible tube base material 31 is conveyed to the head part 23. At this time, the extrusion parts 21 and 22 are in a state of constantly extruding the first polymer material 39 and the second polymer material 40 and supplying them to the head part 23. The first polymer material 39 and the second polymer material 40 extruded from the extrusion parts 21 and 22 to the gates 35 and 36 pass through the edges, merge, and are supplied to the molding passage 37 through the polymer passage 38 in an overlapping state. Thereby, a two-layer molded polymer coating layer 15 in which the inner layer 17 using the first polymer material 39 and the outer layer 18 using the second polymer material 40 overlap is formed.

[0082] The connectable flexible tube base material 31 is formed by connecting a plurality of flexible tube base materials 14 (a siloxane compound-containing layer and a primer layer are formed on the outer periphery of the flexible tube base material 14). During conveyance in the molding passage 37, the polymer coating layer 15 is continuously formed on the plurality of flexible tube base materials 14. When forming the polymer coating layer 15 from one end 14a side (tip side) to the other end 14b side (base end side) of one flexible tube base material, immediately after starting the discharge of the polymer by the extruding portions 21 and 22, the thickness of the inner layer 17 is made thick. Then, the ratio of the thickness of the outer layer 18 is gradually increased in the intermediate portion toward the other end 14b side. Thus, it is preferable to control the discharge amount of the polymer so as to obtain the above-described inclined thickness ratio of the polymer coating layer 15.

[0083] Since the joint member 30 is a connecting portion of two flexible tube base materials 14, the control unit 26 is used to switch the discharge amounts of the extruding portions 21 and 22. Specifically, the control unit 26 preferably switches the discharge amounts of the extruding portions 21 and 22 so that the ratio of the thickness at the other end 14b side (base end side) of one flexible tube base material 14 becomes the ratio of the thickness at one end 14a side (tip side) of the next flexible tube base material 14. When forming the polymer coating layer 15 from one end 14a side to the other end 14b side of the next flexible tube base material 14, it is preferable that the extruding portions 21 and 22 are controlled so that the thickness of the outer layer gradually increases from one end side to the other end side in the same manner.

[0084] After the connectable flexible tube base material 31 with the polymer coating layer 15 formed up to the rearmost end is removed from the continuous molding machine 20, the joint member 30 is removed from the flexible tube base material 14 and separated into each flexible tube base material 14. Next, the top coat layer 16 is coated on the polymer coating layer 15 for the separated flexible tube base material 14, and the flexible tube 3a is completed. The completed flexible tube 3a is conveyed to the assembly process of the electronic endoscope.

[0085] In the present invention, when the polymer coating layer is a multi-layer, a functional layer may be interposed between the layers constituting the multi-layer. The above description has been given by taking, as an example, an endoscope that observes an image obtained by imaging the state of a subject using an imaging device with reference to the drawings. However, the present invention is not limited to this, and can also be applied to an endoscope that observes the state of a subject by adopting an optical image guide.

[0086] The flexible tube of the present invention can be widely applied to endoscope-type medical devices. For example, it can also be applied to those equipped with clips or wires at the tip of an endoscope, or to instruments equipped with baskets or brushes. Note that the endoscope-type medical device, in addition to the medical device having the above-described endoscope as its basic structure, widely includes medical or diagnostic devices such as remotely operated medical devices, the insertion part of which has flexibility and is introduced into the body for use. The endoscope-type medical device of the present invention has the flexible tube for endoscope of the present invention incorporated in its insertion part. That is, the manufacturing method of the endoscope-type medical device of the present invention includes incorporating the flexible tube for endoscope of the present invention into the insertion part of the endoscope-type medical device.

Example

[0087] Hereinafter, the present invention will be described in more detail through examples, but the present invention is not construed as being limited thereby.

[0088] [Fabrication of Flexible Tube for Endoscope] A flexible tube having the structure shown in FIG. 2 was fabricated. The polymer coating layer had a single-layer structure or a two-layer structure as shown in Table 2 below.

[0089] <Flexible Tube Substrate> A flexible tube substrate was prepared in a form in which a spiral tube 11 was formed using a metal strip 11a made of stainless steel (SUS304), and this spiral tube 11 was covered with a cylindrical net body 12 woven with fibers made of SUS304. This flexible tube substrate has a length of 80 cm and a diameter of 12 mm. This stainless steel flexible tube has a passive layer formed on its surface by annealing treatment (heat treatment) during the formation of the spiral tube and the cylindrical net body. The flexible tube substrate was degreased with acetone and then immersed in a 1N aqueous sodium hydroxide solution at 50°C for 3 minutes for washing. Subsequently, it was rinsed three times with distilled water and then dried in an oven heated to 100°C for 10 minutes to prepare the flexible tube substrate.

[0090] <Formation of the siloxane compound-containing layer (L-1)> 20 g of tetraethoxysilane, 20 g of methyltriethoxysilane, 9 g of ethanol, 14 g of water, and 33 g of a 0.3 mass% hydrochloric acid aqueous solution were mixed and stirred in a water bath at 63°C for 30 minutes, and then further stirred at room temperature for 30 minutes to prepare mixture (A). To this mixture (A), 15 g of a nonionic surfactant (a polyethylene oxide - polypropylene oxide - polyethylene oxide triblock polymer, "PLURONIC P-123 (trade name)" manufactured by BASF, number average molecular weight 5,800) and 12 g of ethanol were mixed and stirred at room temperature for 60 minutes to prepare mixture (B). This mixture (B) was diluted 25-fold with 1-butanol and filtered through a filter with a pore size of 0.45 μm to obtain a silica composition (C) (solid content 1.0%). The washed flexible tube substrate was immersed in the silica composition (C) for 5 minutes and then pulled out and air-dried at 40°C for 30 minutes. This flexible tube substrate was heated in an oven at 300°C for 5 minutes to thermally decompose and remove the nonionic surfactant, thereby forming a siloxane compound-containing layer (L-1) on the outer periphery of the flexible tube substrate. The siloxane compound-containing layer (L-1) has a porous structure and an average layer thickness of 50 nm. This siloxane compound-containing layer (L-1) has a hydroxy group.

[0091] <Formation of the siloxane compound-containing layer (L-2)> 20 g of hydrolyzed silicate (manufactured by Nippon Colcoat Co., Ltd., trade name "N-103X", solid content 2.0 mass%, isopropyl alcohol / n-butanol solvent) was diluted with 980 g of ethanol to prepare a silica-based composition (D) (solid content 0.04%). After the flexible tube substrate after the above cleaning was immersed in the silica composition (D) for 1 minute, it was pulled up and air-dried at 30°C for 30 minutes. The flexible tube substrate after air-drying was heated in an oven at 100°C for 15 minutes to form a siloxane compound-containing layer (L-2) on the outer periphery of the flexible tube substrate.

[0092] <Formation of Siloxane Compound-Containing Layers (L-3) to (L-10)> Except for using the components described in Table 1 below, siloxane compound-containing layers (L-3) to (L-10) were formed on the outer periphery of the flexible tube substrate in the same manner as the siloxane compound-containing layer (L-2). That is, each flexible tube substrate having siloxane compound-containing layers (L-3) to (L-10) on the outer periphery was obtained. These siloxane compound-containing layers (L-3) to (L-10) have hydroxyl groups.

[0093] <Formation of Epoxy Resin Layer (R-1)> In a stainless steel container, 6.0 g of bisphenol A type epoxy resin (manufactured by Mitsubishi Chemical Corporation, trade name "jER828", epoxy equivalent 184 to 194 g / eq.) and 990 g of methyl ethyl ketone were mixed, and then 4.0 g of 1,6-diaminohexane was added. After that, it was stirred at room temperature for 15 minutes using a three-way motor to obtain an epoxy resin solution (E). The flexible tube substrate after the above cleaning was immersed in the epoxy resin solution (E) for 5 minutes, then pulled up and air-dried at 40°C for 30 minutes to volatilize methyl ketyl ketone. This flexible tube substrate was heated in an oven at 100°C for 3 hours to form an epoxy resin layer (R-1) on the outer periphery of the flexible tube substrate. The average layer thickness of the epoxy resin layer (R-1) is 80 nm.

[0094]

Table 1

[0095] <Note of Table 1> N-103X: Hydrolyzed silicate (manufactured by Nippon Colcoat Co., Ltd., "N-103X" (trade name), solid content 2.0% by mass, isopropyl alcohol / n-butanol solvent, in a hydrolyzed state, having a hydroxy group.) HAS-10: Hydrolyzed silicate (manufactured by Nippon Colcoat Co., Ltd., "HAS-10" (trade name), solid content 10.2% by mass, methanol / isopropyl alcohol / ethanol solvent, in a hydrolyzed state, having a hydroxy group.)

[0096] The average layer thickness of the siloxane compound-containing layer was calculated as follows. The above-prepared flexible tube substrate was randomly cut at 5 locations, and each cross-section of the siloxane compound-containing layer was observed at 50,000 times with a scanning electron microscope (S-5500 (trade name), manufactured by Hitachi High-Technologies Corporation). For each cross-section, the thickness of the siloxane compound-containing layer formed on the outer periphery was obtained one by one. The average value from the obtained 5 thickness values was taken as the average layer thickness.

[0097] <Formation of primer layer> 150 g of ethanol, 350 g of water, and 1.0 g of N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (SI-1, trade name: KBM-603, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed to obtain a coating solution for forming a primer layer. The flexible tube substrate having a siloxane compound-containing layer was immersed in the coating solution for forming a primer layer prepared above at room temperature for 1 minute, air-dried for 10 minutes, and then placed in an oven at 100 °C and heated and dried for 10 minutes to prepare a flexible tube substrate having a primer layer on the siloxane compound-containing layer (the flexible tube substrate used in Example 1). In the same manner as above, flexible tube substrates used in each example and each comparative example were prepared using the raw materials as described in Table 2 (Table 2-1 and 2-2). Note that in Comparative Example 3, no primer layer was formed.

[0098] <Formation of polymer coating layer> On the outer periphery of a flexible tube substrate provided with a primer layer on a siloxane compound-containing layer or an epoxy resin layer, a polymer as described in Table 2 below was extrusion-coated (molding temperature: melting point of the polymer + 10 °C) to produce a flexible endoscope tube having a polymer coating layer. The thickness of the polymer coating layer was 0.4 mm (in the case of a two-layer structure, the combined thickness of the two layers was 0.4 mm). When the polymer coating layer was made into two layers, the two layers were simultaneously coated and molded by two-layer extrusion molding. In this case, the inner layer: outer layer ratio at the tip and the rear end was set to inner layer: outer layer = 80:20 at the tip and inner layer: outer layer = 20:80 at the rear end. From the tip to the rear end, the thicknesses of the inner layer and the outer layer were inclined.

[0099] The following tests were conducted on the produced flexible tube. The results are summarized in Table 2 below.

[0100] [Test Example 1] Evaluation of the resilience of the flexible tube In an environment of a temperature of 25 °C and a relative humidity of 50%, positions 30 cm and 50 cm from one tip of the flexible endoscope tube produced above were fixed, and the position at 40 cm (the center of the flexible tube) was pushed in 15 mm in a direction perpendicular (diameter direction) to the length direction of the flexible tube. The ratio of the repulsive force (b) after 30 seconds to the repulsive force (a) after 0.1 second was measured as the resilience (%). The repulsive force was measured using a force gauge (ZTS50N (trade name), manufactured by IMADA). [Resilience (%)] = [(b) / (a)] × 100 The above resilience was evaluated according to the following evaluation criteria. A "C" or above is considered a pass. <Resilience evaluation criteria> A: Resilience is 80% or more B: Resilience is 75% or more and less than 80% C: Resilience is 65% or more and less than 75% D: Resilience is less than 65%

[0101] [Test Example 2] Evaluation of the thermal durability of the flexible tube The flexible endoscope tube produced above was continuously heated at 60 °C for 1,500 hours using a thermo-hygrostat (KHWV-40HP (trade name), manufactured by Satake Chemical Machinery Co., Ltd.). The following peeling test was performed on the flexible endoscope tube before heat treatment and the flexible endoscope tube after heat treatment. (Peeling test) A 1-cm-wide cut was made along the axial direction of the flexible tube so that the cut reached the flexible tube substrate with respect to the polymer coating layer of the flexible endoscope tube. The formed 1-cm-wide cut has a 1-cm width on the outer peripheral surface of the polymer coating layer. The 90° peel strength between the flexible tube substrate and the polymer coating layer (the innermost layer in the case of two layers) was measured by grasping the edge of the prepared 1-cm-wide cut and peeling it at a constant speed along the axial direction of the flexible tube while maintaining an angle of 90° between the flexible tube substrate and the peeled polymer coating layer. The peel strength is the value measured by a force gauge, and the unit is N / cm. Regarding the 90° peel strength of the flexible endoscope tube before heat treatment as "PSB(1)" and the 90° peel strength of the flexible endoscope tube after heat treatment as "PSA(1)", the ratio of "PSA(1)" to "PSB(1)" {(PSA(1) / PSB(1))×100(%)} was determined and evaluated according to the following criteria. "C" or above is considered qualified. <Heat durability evaluation criteria> AA: 90% or more A: 80% or more and less than 90% B: 60% or more and less than 80% C: 40% or more and less than 60% D: Less than 40%

[0102] [Test Example 3] Evaluation of hydrogen peroxide water resistance Both ends of the flexible endoscope tube prepared above were capped with Teflon (registered trademark) plugs and immersed in 5.0% hydrogen peroxide water at 55°C for 150 hours. After immersion, the surface was thoroughly washed with water to prepare a flexible endoscope tube after immersion in hydrogen peroxide water. For each of the flexible endoscope tubes before hydrogen peroxide solution immersion and the flexible endoscope tubes after hydrogen peroxide solution immersion, a peeling test was conducted in the same manner as in Test Example 2, and the peel strength was measured. The 90° peel strength of the flexible endoscope tube before hydrogen peroxide solution immersion was designated as "PSB(2)", and the 90° peel strength of the flexible endoscope tube after hydrogen peroxide solution immersion was designated as "PSA(2)". The ratio of "PSA(2)" to "PSB(2)" {(PSA(2) / PSB(2))×100(%)} was determined and evaluated according to the following criteria. A value of "C" or higher indicates passing. <Hydrogen peroxide solution resistance evaluation criteria> AA: 90% or more A: 80% or more and less than 90% B: 60% or more and less than 80% C: 40% or more and less than 60% D: Less than 40%

[0103]

Table 2-1

[0104]

Table 2-2

[0105] <Notes to Table 2>

[0106] Ex: Example Comp: Comparative Example In Comparative Example 2, for easy comparison with the examples, an epoxy resin layer (R-1) is described in the row of the siloxane compound-containing layer.

[0107] The abbreviations described in the above table are as follows.

[0108] (Silane coupling agent) (SI-1): N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (product name: KBM-603, manufactured by Shin-Etsu Chemical Co., Ltd.) (SI-2): 3-Aminopropyltrimethoxysilane (product name: KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.) (SI-3): N-Methylaminopropyltrimethoxysilane (SI-4): 3-Ureidopropyltrialkoxysilane (product name: KBE-585, manufactured by Shin-Etsu Chemical Co., Ltd.) (SI-5): N-phenyl-3-aminopropyltrimethoxysilane (product name: KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) (SI-6): 3-Trimethoxysilylpropylsuccinic anhydride (product name: X-12-967C, manufactured by Shin-Etsu Chemical Co., Ltd.) (SI-7): (3-Methacryloxypropyl)trimethoxysilane (product name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) (SI-8): 3-Glycidoxypropyltrimethoxysilane (product name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) (SI-9): 3-Mercaptopropyltrimethoxysilane (product name: KBM-803, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0109] (Aluminum coupling agent) (AL-1): Aluminum sec-butoxide (product name: ASBD, manufactured by Kawaken Fine Chemicals Co., Ltd.) (AL-2): Aluminum trisacetylacetonate (product name: Orgatics AL-3100, manufactured by Matsumoto Fine Chemical Co., Ltd.) (AL-3): Aluminum bis(ethylacetoacetate) mono(acetylacetonate) (Trade name: ORGAX AL-3200, manufactured by Matsumoto Fine Chemical Co., Ltd.) (AL-4): Aluminum tris(ethylacetoacetate) (Trade name: ORGAX AL-3215, manufactured by Matsumoto Fine Chemical Co., Ltd.) (AL-5): Aluminum octadecylacetoacetate diisopropylate (Trade name: PUREACT AL-M, manufactured by Ajinomoto Fine-Techno Co., Inc.)

[0110] (Zirconium coupling agent) (ZR-1): Zirconium tetra n-propoxide (Trade name: ORGAX ZA-45, manufactured by Matsumoto Fine Chemical Co., Ltd.) (ZR-2): Zirconium tetra n-butoxide (Trade name: ORGAX ZA-65, manufactured by Matsumoto Fine Chemical Co., Ltd.) (ZR-3): Zirconium tetraacetylacetonate (Trade name: ORGAX ZC-150, manufactured by Matsumoto Fine Chemical Co., Ltd.) (ZR-4): Zirconium lactate ammonium salt (Trade name: ORGAX ZC-300, manufactured by Matsumoto Fine Chemical Co., Ltd.) (ZR-5): Zirconium stearate tri n-butoxide (Trade name: ORGAX ZC-320, manufactured by Matsumoto Fine Chemical Co., Ltd.)

[0111] (Titanium coupling agent) (TI-1): Tetra n-butyl titanate (Trade name: ORGAX TA-21, manufactured by Matsumoto Fine Chemical Co., Ltd.) (TI-2): n-Butyl titanate dimer (Trade name: ORGAX TA-23, manufactured by Matsumoto Fine Chemical Co., Ltd.) (TI-3): Isopropyltriisostearoyl titanate (trade name: Prenact TTS, manufactured by Ajinomoto Fine-Techno Co., Inc.) (TI-4): Dioctylbis(ditridecyl) phosphate titanate (trade name: Prenact 46B, manufactured by Ajinomoto Fine-Techno Co., Inc.) (TI-5): Diisopropylbis(dioctyl pyrophosphate) titanate (trade name: Prenact 38S, manufactured by Ajinomoto Fine-Techno Co., Inc.)

[0112] (U-1): Polyether polyurethane elastomer (trade name: Pandex T-8185, manufactured by DIC Corporation) (U-2): Polyether polyurethane elastomer (trade name: Milactran E380, manufactured by Nippon Polyurethane Industry Co., Ltd.) (U-3): Polyester polyurethane elastomer (trade name: Milactran E480, manufactured by Nippon Polyurethane Industry Co., Ltd.) (U-4): Polycarbonate polyurethane elastomer (trade name: Pandex T-9280, manufactured by DIC Corporation) (E-1): Polyester elastomer (trade name: Pelprene P-40B, manufactured by Toyobo Co., Ltd.) (A-1): Polyamide elastomer (trade name: Pebax 4533, manufactured by Arkema) (P-1): Polyolefin elastomer: Zelas MC707 (trade name), manufactured by Mitsubishi Chemical Corporation (F-1): Fluorine-containing elastomer: Dai-el T-530 (trade name), manufactured by Daikin Industries, Ltd.

[0113] It can be seen from Table 2 as follows. The flexible pipes of Comparative Examples 1 and 6 to 8 that do not have the siloxane compound-containing layer defined in the present invention are inferior in heat durability and hydrogen peroxide water resistance even if they have a primer layer. The flexible tube of Comparative Example 2 has an epoxy resin layer between the flexible tube base material and the primer layer instead of the siloxane compound-containing layer. However, this flexible tube is inferior in heat durability and hydrogen peroxide water resistance. The flexible tubes of Comparative Examples 3 and 9 have the siloxane compound-containing layer defined in the present invention, while not having the primer layer defined in the present invention. All of these flexible tubes are inferior in resilience, heat durability, and hydrogen peroxide water resistance. The flexible tube of Comparative Example 4 has a layer of fluorine-containing elastomer as the polymer coating layer. Further, the flexible tube of Comparative Example 5 has a layer of fluorine-containing elastomer as the polymer coating layer on the side in contact with the primer layer. That is, these flexible tubes do not have the polymer coating layer defined in the present invention on the side in contact with the primer layer. The flexible tube of Comparative Example 4 is inferior in all of resilience, heat durability, and hydrogen peroxide water resistance, and the flexible tube of Comparative Example 5 is inferior in heat durability and hydrogen peroxide water resistance. On the other hand, the flexible tubes of Examples 1 to 48 of the present invention have sufficient resilience, are excellent in heat durability, and further are excellent in hydrogen peroxide water resistance.

Explanation of Signs

[0114] 2 Electronic endoscope (endoscope) 3 Insertion portion 3a Flexible tube 3b Angle portion 3c Tip portion 5 Main body operation portion 6 Universal cord 11 Spiral tube 11a Metal strip 12 Cylindrical net body 13 Base 14 Flexible tube base material 14a Tip side 14b Base end side 15 Polymer coating layer 16 Top coat layer 17 Inner layer 18 Outer layer X Angle portion 3b side (soft) Y Main body operation portion 5 side (hard) 20 Continuous molding machine (manufacturing apparatus) 21 and 22 Extrusion Sections 21a Screw 22a Screw 23 Head Section 24 Cooling Section 25 Conveying Section 26 Control Section 28 Supply Drum 29 Take-up Drum 30 Joint Member 31 Connectable Flexible Tube Base Material 32 Nipple 33 Die 34 Support 35 and 36 Gates 37 Forming Passage 38 Polymer Passage 39 First Polymer Material (Soft Polymer) 40 Second Polymer Material (Hard Polymer)

Claims

1. A flexible tube base material made of metal as a constituent material, a siloxane compound-containing layer on the flexible tube base material, a primer layer on the siloxane compound-containing layer, and a polymer coating layer on the primer layer, and the siloxane compound has a hydroxy group, the primer layer contains at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent, the polymer coating layer contains at least one compound of polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer, a flexible tube for an endoscope.

2. The flexible tube for an endoscope according to claim 1, wherein the siloxane compound contains an organic siloxane compound.

3. The flexible tube for an endoscope according to claim 1 or 2, wherein the primer layer contains a silane coupling agent.

4. The flexible tube for an endoscope according to any one of claims 1 to 3, wherein the primer layer contains an aminosilane coupling agent.

5. The flexible tube for an endoscope according to any one of claims 1 to 4, wherein the metal constituting the flexible tube base material is stainless steel.

6. The flexible tube for an endoscope according to any one of claims 1 to 5, wherein the metal constituting the flexible tube base material has a passive film on its surface.

7. The flexible tube for an endoscope according to any one of claims 1 to 6, wherein the polymer coating layer has a single-layer structure or a multi-layer structure, and contains at least one compound of polyamide, polyester, polyurethane, and polyolefin in the layer in contact with the primer layer.

8. The flexible tube for an endoscope according to any one of claims 1 to 7, wherein the polymer coating layer has a two-layer structure, and the ratio of the thicknesses of the inner layer and the outer layer of the two-layer structure changes inclinedly in the axial direction of the flexible tube base material.

9. The flexible tube for an endoscope according to claim 8, wherein the ratio of the thicknesses of the inner layer and the outer layer is inner layer: outer layer = 95:5 to 60:40 at one end of the flexible tube for an endoscope, and inner layer: outer layer = 5:95 to 40:60 at the other end.

10. An endoscope-type medical device having the flexible tube for an endoscope according to any one of claims 1 to 9.

11. Providing a siloxane compound-containing layer on a flexible tube base material made of metal as a constituent material, providing a primer layer on the siloxane compound-containing layer, and providing a polymer coating layer on the primer layer, and the siloxane compound has a hydroxy group, The primer layer contains at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent, A method for manufacturing a flexible tube for an endoscope, wherein the polymer coating layer contains at least one compound of polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer.

12. A method for manufacturing an endoscope-type medical device, comprising incorporating the flexible tube for an endoscope obtained by the method for manufacturing a flexible tube for an endoscope according to claim 11 into an insertion portion of the endoscope-type medical device.

13. A method for manufacturing an endoscope-type medical device, comprising incorporating the flexible tube for an endoscope according to any one of claims 1 to 9 into an insertion portion of the endoscope-type medical device.

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