Flexible tube for endoscope, endoscope-type medical instrument, and method for manufacturing the same

Abstract

The present application provides a flexible tube for an endoscope, an endoscope medical instrument provided with the flexible tube for an endoscope, and a manufacturing method thereof, the flexible tube for an endoscope being excellent in resilience, being able to sufficiently maintain the adhesion between a flexible tube base material and a polymer coating layer covering the same even if a bending operation is repeatedly performed, and not easily suffering from a decrease in resilience even if repeatedly heated. The flexible tube for an endoscope has a flexible tube base material (14) made of metal, a porous layer on the flexible tube base material, a primer layer on the porous layer, and a polymer coating layer on the primer layer, the polymer coating layer (15) containing at least one compound among polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer.

Description

Technical Field

[0001] This invention relates to a flexible tube for endoscopy, an endoscopic medical device, and a method for manufacturing the same. Background Technology

[0002] An endoscope is a medical instrument used to observe the inside of a patient's body cavities, digestive tract, esophagus, etc. Because it is inserted into the body, it is desirable to avoid damaging organs and causing pain or discomfort to the patient. Based on these requirements, the flexible tube constituting the insertion part (the structural part inserted into the body cavity) of the endoscope is a spiral tube formed by winding a soft, flexible metal strip into a helix. Furthermore, the spiral tube is coated with a soft polymer, which, if necessary, is further coated to prevent irritation or damage to the inner surfaces of the esophagus, digestive tract, body cavities, etc.

[0003] To ensure smooth movement of the flexible tube within the body, high resilience is required. By improving the resilience of the flexible tube, it easily returns to a straight shape after passing through a bend within the body, thus reducing the burden on the patient during examination. As a technique to meet this requirement, for example, Patent Document 1 describes a method where a primer is applied to the surface of a metal core material (flexible tube substrate), followed by a molded outer skin layer; the primer can be a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, or a zirconium coupling agent. According to Patent Document 1, this flexible tube for endoscopy exhibits excellent resilience.

[0004] Previous technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-035923 Summary of the Invention

[0007] The technical problem to be solved by the invention

[0008] On the other hand, to improve the operability and durability of endoscopes, it is crucial to enhance the adhesion between the flexible tube substrate and the polymer coating covering it. If this adhesion is insufficient, wrinkling, lifting, cracking, and peeling can easily occur on the polymer coating due to the bending of the flexible tube when it is inserted into the body. Furthermore, twisting can easily occur on the polymer coating when the flexible tube is rotated after insertion. If wrinkling, lifting, cracking, peeling, or twisting occurs on the polymer coating, the surface of the inserted flexible tube may snag on surrounding tissues, causing pain to the patient. However, the flexible tube for endoscopes described in Patent Document 1 does not fully meet the requirements for the adhesion between the flexible tube substrate and the polymer coating.

[0009] Furthermore, endoscopes are placed in a heated environment generated by their built-in illumination source during use. Endoscopes are also sometimes placed in heated environments reaching temperatures up to approximately 60°C during sterilization or treatment with medications. The inventors have discovered that repeated use of the endoscope exposes the flexible tube to thermal cycling, resulting in decreased resilience. Therefore, it is required that the flexible tube for endoscopes possess characteristics that are not easily affected by thermal cycling (resilience does not easily decrease even after repeated heating).

[0010] The present invention aims to provide a flexible endoscope tube and an endoscopic medical device incorporating the flexible endoscope tube. The flexible endoscope tube exhibits excellent resilience, maintaining sufficient adhesion between the flexible tube substrate and the polymer coating even under repeated bending operations. Furthermore, its resilience does not easily decrease even under repeated heating. The present invention also aims to provide a method for manufacturing the aforementioned flexible endoscope tube and the aforementioned endoscopic medical device.

[0011] means for solving technical problems

[0012] In view of the aforementioned problems, the inventors conducted repeated studies on the formation of polymer coatings on flexible tubes for endoscopes. They discovered that by forming a porous layer (porous material layer) on the surface of a flexible tube substrate made of a metallic material, forming a primer layer on this porous layer, and then using a specific type of polymer as the constituent material of the polymer coating layer adjacent to the primer layer, the aforementioned problems can be solved. This invention was completed based on further repeated studies of these insights.

[0013] The above-mentioned problems of the present invention are solved by the following solution.

[0014] <1>

[0015] A flexible tube for endoscopes comprises a flexible tube substrate made of metal, a porous layer on the flexible tube substrate, a primer layer on the porous layer, and a polymer coating layer on the primer layer.

[0016] The polymer coating layer comprises at least one compound selected from polyamide, polyester, polyurethane and polyolefin on the side in contact with the primer layer.

[0017] <2>

[0018] according to <1> The flexible tube for the endoscope, wherein,

[0019] The porous layer contains a polymer compound, and the average pore size of the porous layer is 50 nm to 100 μm.

[0020] <3>

[0021] according to <1> or <2> The flexible tube for the endoscope, wherein,

[0022] The aforementioned primer layer contains at least one of silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent.

[0023] <4>

[0024] according to <1> ~ <3> The flexible tube for the endoscope described in any one of the following statements, wherein,

[0025] The aforementioned primer layer contains a silane coupling agent.

[0026] <5>

[0027] according to <1> ~ <4> The flexible tube for the endoscope described in any one of the following statements, wherein,

[0028] The aforementioned primer layer contains an aminosilane coupling agent.

[0029] <6>

[0030] according to <1> ~ <5> The flexible tube for the endoscope described in any one of the following statements, wherein,

[0031] The metal constituting the flexible tube substrate is stainless steel.

[0032] <7>

[0033] according to <1> ~ <6> The flexible tube for the endoscope described in any one of the following statements, wherein,

[0034] The metal constituting the above-mentioned flexible tube substrate has a passivation film on its surface.

[0035] <8>

[0036] according to <1> ~ <7> The flexible tube for the endoscope described in any one of the following statements, wherein,

[0037] The polymer coating is a single-layer or multi-layer structure, and the layer in contact with the primer layer contains at least one compound selected from polyamide, polyester, polyurethane and polyolefin.

[0038] <9>

[0039] according to <1> ~ <8> The flexible tube for the endoscope described in any one of the following statements, wherein,

[0040] The polymer coating has a double-layer structure, and the ratio of the thickness of the inner and outer layers of the double-layer structure varies gradually along the axial direction of the flexible tube substrate.

[0041] <10>

[0042] according to <1> ~ <9> The flexible tube for the endoscope described in any one of the following statements, wherein,

[0043] The thickness ratio of the inner and outer layers is 95:5 to 60:40 at one end of the flexible tube for the endoscope, and 5:95 to 40:60 at the other end.

[0044] <11>

[0045] An endoscopic medical device, which has <1> ~ <10> The flexible tube for endoscopes as described in any one of these descriptions.

[0046] <12>

[0047] A method for manufacturing a flexible tube for endoscopes includes forming a porous layer with an average pore size of 50 nm to 100 μm on a flexible tube substrate made of metal, forming a primer layer on the porous layer, and forming a polymer coating layer on the primer layer.

[0048] The polymer coating layer contains at least one compound selected from polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer.

[0049] <13>

[0050] A method for manufacturing an endoscopic medical device, comprising: passing through... <12> The endoscope flexible tube obtained by the manufacturing method of the described endoscope flexible tube is assembled into the insertion part of the endoscope type medical device.

[0051] <14>

[0052] A method for manufacturing an endoscopic medical device, comprising: <1> ~ <10> The endoscope is assembled into the insertion part of the endoscopic medical device using a flexible tube as described in any one of the above methods.

[0053] In this specification, when there are multiple substituents or linking groups (hereinafter referred to as substituents, etc.) indicated by specific symbols, or when multiple substituents, etc., are specified simultaneously or alternatively, it means that the individual substituents, etc., may be the same as or different from each other. Furthermore, even without specific explanation, when multiple substituents, etc., are adjacent, it means that they may also be linked together or cyclically contracted to form a ring.

[0054] In this specification, the term "substituent" (and the same applies to linking groups) that is not explicitly stated as substituted or unsubstituted means that the group may have any substituents to achieve the desired effect. This meaning also applies to compounds that are not explicitly stated as substituted or unsubstituted.

[0055] In this specification, when the number of carbon atoms of a certain group is specified, that number of carbon atoms refers to the total number of carbon atoms of the group as a whole. That is, when the group is in the form of further having substituents, it refers to the total number of carbon atoms including the substituents.

[0056] Invention Effects

[0057] The flexible tube for endoscopes of the present invention has excellent resilience. Even when repeatedly bent, it can maintain sufficient adhesion between the flexible tube substrate and the polymer coating covering it. In addition, even when placed in the heat cycle that accompanies repeated use of the endoscope, it is not easy for the resilience to decrease.

[0058] The flexible tube, which serves as the insertable structural part of the endoscopic medical device of the present invention, exhibits excellent resilience. Even with repeated bending operations, it can maintain sufficient adhesion between the flexible tube substrate and the polymer coating covering it. Furthermore, even when subjected to repeated thermal cycling during use, it is not prone to a decrease in resilience. Therefore, the endoscopic medical device of the present invention has excellent durability, further reducing the burden on the patient during use.

[0059] According to the manufacturing method of the flexible tube for endoscope of the present invention, a flexible tube for endoscope can be obtained with excellent resilience. Even when repeatedly bent, the adhesion between the flexible tube substrate and the polymer coating covering it can be fully maintained. In addition, even when placed in the heat cycle that accompanies repeated use of the endoscope, the resilience is not easily reduced.

[0060] According to the manufacturing method of the endoscopic medical device of the present invention, the flexible tube constituting the device can be characterized by excellent resilience, maintaining sufficient adhesion between the flexible tube substrate and the polymer coating layer covering it even under repeated bending operations, and exhibiting minimal resilience loss even when subjected to thermal cycling during repeated use of the endoscope. Therefore, the manufacturing method of the endoscopic medical device of the present invention provides an endoscopic medical device with excellent durability and reduced burden on the patient during use. Attached Figure Description

[0061] Figure 1 This is an external view showing the structure of one embodiment of an electronic endoscope.

[0062] Figure 2 This is a partial cross-sectional view showing the structure of one embodiment of a flexible tube for endoscopy.

[0063] Figure 3 This is a block diagram illustrating the structure of one embodiment of a manufacturing apparatus for a flexible tube for an endoscope.

[0064] Figure 4 It is Figure 3 A sectional view obtained by cutting along the BB line. Detailed Implementation

[0065] Taking an electronic endoscope as an example, a preferred embodiment of an endoscopic medical device assembled with the flexible endoscopic tube of the present invention (hereinafter, the flexible endoscopic tube is sometimes simply referred to as a "flexible tube") will be described. The electronic endoscope is used as a medical device for observing the body by inserting the flexible tube into body cavities, the digestive tract, the esophagus, etc. Figure 1 In the example shown, the electronic endoscope 2 includes an insertion part 3 for insertion into the body, a main operating part 5 connected to the base of the insertion part 3, and a universal plug 6 connected to a processor and a light source. The insertion part 3 consists of a flexible tube 3a connected to the main operating part 5, a bend 3b connected to the flexible tube 3a, and a tip 3c connected to the tip of the bend 3b and housing an in-body imaging device (not shown). The flexible tube 3a, occupying most of the length of the insertion part 3, is flexible almost entirely, especially the portion inserted into a body cavity or other internal space, which is made even more flexible. Figure 1 In the middle, the curved part 3b side has a soft structure, while the main body operating part 5 side has a hard structure.

[0066] [Flexible tube for endoscopes]

[0067] The flexible endoscope tube of the present invention comprises a flexible tube substrate made of metal, a porous layer on the flexible tube substrate, a primer layer on the porous layer, and a polymer coating layer on the primer layer. The polymer coating layer contains at least one compound selected from polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer. Specifically, the flexible endoscope tube sequentially comprises a flexible tube substrate made of metal, a porous layer, a primer layer, and a polymer coating layer, wherein the polymer coating layer contains at least one compound selected from the group consisting of polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer.

[0068] In addition, Figure 2 The porous layer and primer layer are not shown in the diagram.

[0069] The flexible endoscope tube of the present invention exhibits excellent resilience. Even with repeated bending operations, it can maintain sufficient adhesion between the flexible tube substrate and the polymer coating covering it. Furthermore, even with repeated heating, its resilience does not easily decrease. The reason for this is not yet clear, but one speculated reason is the anchoring effect of the polymer coating entering the pores of the porous layer while in close contact with the primer layer.

[0070] <Flexible tube substrate>

[0071] Flexible tubes have a flexible tube substrate made of metal as the innermost layer.

[0072] like Figure 2As shown, the flexible tube substrate 14 is preferably configured as follows: a cylindrical mesh 12 formed by covering a spiral tube 11, which is formed by spirally winding a metal strip 11a around the innermost side, is covered with a braided metal wire, and tube ends 13 are respectively fitted to both ends. To prevent corrosion, the surface of the metal constituting the flexible tube substrate 14 is preferably subjected to passivation treatment. That is, the flexible tube substrate 14 preferably has a passivation film (e.g., a metal oxide film) on its outer periphery. This passivation treatment can be performed by common methods. For example, a passivation film can be formed on the metal surface by immersion in a solution containing a strong oxidizing agent such as nitric acid, heating in air (oxygen) or water (water vapor), or anodizing in a solution containing an oxidizing agent.

[0073] The metal constituting the flexible tube substrate 14 is preferably stainless steel. The surface of stainless steel is usually in a state where chromium and oxygen combine to form a passivation film. However, even when stainless steel is used as the constituent material of the flexible tube substrate 14, in order to more reliably form a more uniform passivation film across the entire stainless steel surface, it is preferable to apply the above-described passivation treatment to the stainless steel.

[0074] <Porous layer>

[0075] The porous layer (porous material layer) constituting the flexible tube of the present invention has a plurality of pores (pores) in the layer. Examples of pore shapes include spheres and ellipsoids. The pores can be individual pores or continuous pores formed by connecting individual pores.

[0076] The average pore size of the porous layer is not particularly limited. Considering resilience, sealing, and heat resistance, for example, 50 nm to 300 μm is preferred, more preferably 70 nm to 100 μm, even more preferably 150 nm to 100 μm, even more preferably 300 nm to 25 μm, even more preferably 450 nm to 25 μm, and even more preferably 450 nm to 5 μm. In the specification of this application, the average pore size is a value determined by the method described in the examples described later.

[0077] The porosity of the porous layer is not particularly limited, for example, preferably 10-80%, more preferably 20-60%, and even more preferably 30-50%. In the description of this application, "porosity" is the proportion of the volume of the pores in the total volume of the porous layer containing the pores, and is a value determined by the method described in the embodiments described later.

[0078] The average thickness of the porous layer is not particularly limited; for example, it is preferably 0.01 to 1000 μm, more preferably 0.05 to 500 μm, and even more preferably 0.1 to 50 μm. In the specification of this application, the average layer thickness is a value determined by the method described in the embodiments described later.

[0079] The porous layer preferably comprises a polymeric compound. Examples of such polymeric compounds include cross-linked epoxy resins, siloxanes (polysiloxanes), vinyl resins (e.g., acrylic resins and styrene resins), and condensation resins (e.g., polyamides, polyesters, and polycarbonates), and one or more of these can be used. Preferably, at least one of cross-linked epoxy resins and siloxanes is preferred, and more preferably, a cross-linked epoxy resin.

[0080] The content of polymeric compounds in the porous layer is not particularly limited, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and the porous layer can be a layer composed of polymeric compounds (a polymeric compound layer with pores).

[0081] The porous layer may contain stabilizers such as plasticizers, flame retardants, reinforcing agents (e.g., inorganic fillers and metal fillers) and antioxidants, in addition to polymer compounds, within the range that does not impair the effects of the present invention.

[0082] As a porous layer containing an epoxy resin crosslinker (hereinafter also referred to as "epoxy resin porous layer"), epoxy resin porous membranes, such as those described in Japanese Patent Application Publication No. 2010-77358 and Japanese Patent Application Publication No. 2013-18966, can be used as the porous layer constituting the flexible tube of the present invention.

[0083] As a porous layer containing siloxane (hereinafter also referred to as "silica porous layer"), for example, the silica-based porous membrane disclosed in Japanese Patent Application Publication No. 2010-64932, the mesoporous silica film disclosed in International Publication Nos. 2003 / 028097 and 2003 / 075335, the porous silica film disclosed in Japanese Patent Application Publication No. 2003-115486, the porous silica film disclosed in Japanese Patent Application Publication No. 2005-202240, and the porous silica film disclosed in Japanese Patent Application Publication No. 2003-268356 can be used as the porous layer constituting the flexible tube of the present invention.

[0084] <Primer layer>

[0085] Considering the resilience of the flexible tube, the adhesion between the flexible tube substrate and the polymer coating, and the heat resistance of the flexible tube, the primer layer constituting the flexible tube of the present invention preferably includes at least one of silane coupling agent, titanium coupling agent, zirconium coupling agent and aluminum coupling agent.

[0086] As silane coupling agents, titanium coupling agents, zirconium coupling agents, and aluminum coupling agents used in this invention, common silane coupling agents, titanium coupling agents, zirconium coupling agents, and aluminum coupling agents applicable to the primer layer of flexible tubes for endoscopes can be widely used. In this invention, considering the resilience of the flexible tube, the adhesion between the flexible tube substrate and the polymer coating layer, and the heat resistance of the flexible tube, silane coupling agents are preferred, and aminosilane coupling agents (preferably silane coupling agents having at least one of unsubstituted amino and monosubstituted amino groups) are more preferred. Specific examples of silane coupling agents, titanium coupling agents, zirconium coupling agents, and aluminum coupling agents used in the following embodiments can be given, but this invention is not limited thereto.

[0087] The total content of silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent in the aforementioned primer layer is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more. Furthermore, the aforementioned primer layer may be a layer composed of at least one of silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent.

[0088] The content of aminosilane coupling agent in the silane coupling agent is preferably 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more.

[0089] Provided that the effects of the present invention are not compromised, the primer layer may contain components other than silane coupling agents, titanium coupling agents, zirconium coupling agents and aluminum coupling agents. Examples of such components include: alkanol metals other than the coupling agents mentioned above, adhesive resins and stabilizers (e.g. surfactants and antioxidants).

[0090] In this invention, "the primer layer comprises at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent" means that it comprises at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent in a state after reacting with the porous layer or flexible tube substrate, and in a state after reacting with the polymer coating layer. For example, the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent are in a state where at least a portion is hydrolyzed and hydroxyl groups are exposed, and they can react with the constituent metals of the porous layer or flexible tube substrate or with the groups on the surface of the polymer coating layer.

[0091] The thickness of the primer layer is significantly thinner than that of ordinary adhesive layers. There is no limitation on the thickness, but it is preferably 1 nm or more and 100 nm or less. That is, the primer layer is different from the adhesive layer used for bonding flexible tube substrates to polymer coatings, which requires a certain thickness and flexibility.

[0092] <Polymer Coating>

[0093] The flexible tube of the present invention has a polymer coating layer on the outer periphery of a flexible tube substrate having a porous layer and a primer layer in sequence.

[0094] exist Figure 2 In this form, an upper coating 16 containing fluorine or the like, which contributes to chemical resistance, is applied to the outer surface of the polymer coating 15. Figure 2 In the figure, only one layer of the spiral tube 11 is shown, but it can also be constructed by overlapping two or more layers coaxially. In addition, in order to clearly illustrate the layer structure, the polymer coating layer 15 and the upper coating layer 16 are drawn to be thicker than the diameter of the flexible tube substrate 14 in the figure.

[0095] In this invention, a polymer coating layer is applied to the outer peripheral surface of a flexible tube substrate having the aforementioned porous layer and primer layer. Figure 2 In this form, the polymer coating layer 15 is a double-layer structure formed by stacking an inner layer 17 covering the entire circumference of the flexible tube substrate 14 around its axis and an outer layer 18 covering the entire circumference of the inner layer 17 around its axis. Typically, the inner layer 17 is made of a soft polymer and the outer layer 18 is made of a hard polymer, but the present invention is not limited to these forms.

[0096] In this invention, as described below, when the polymer coating layer is a multilayer structure with two or more layers, at least the innermost layer (the layer in contact with the primer layer) contains at least one compound selected from polyamide, polyester, polyurethane, and polyolefin. Furthermore, in this invention, when the polymer coating layer is a single layer, the single-layer polymer coating layer contains at least one compound selected from polyamide, polyester, polyurethane, and polyolefin. That is, in this invention, the polymer coating layer contains at least one compound selected from polyamide, polyester, polyurethane, and polyolefin at least on the side in contact with the primer layer, preferably on the side in contact with the primer layer.

[0097] (Polyamide)

[0098] As a polyamide, common polyamides that can be widely used as polymer coatings for flexible tubes used in endoscopes are widely applicable. Examples include crystalline polyamides, amorphous polyamides, and polyamide elastomers.

[0099] There are no particular limitations on crystalline polyamides; examples include aliphatic polyamides and aromatic polyamides.

[0100] Examples of aliphatic polyamides include: poly(ε-hexamethylene adipamide) (polyamide 6), polytetramethylene adipamide (polyamide 46), polyhexamethylene adipamide (polyamide 66), poly(hexamethylene adipamide) / polyhexamethylene adipamide copolymer (polyamide 6 / 66), poly(undecanamide) (polyamide 11), poly(hexamethylene adipamide) / poly(undecanamide) copolymer (polyamide 6 / 11), poly(dodecanoamide) (polyamide 12), poly(hexamethylene adipamide) / poly(dodecanoamide) copolymer (polyamide 6 / 12), poly(hexamethylene sebacate) (polyamide 610), poly(decamethylene sebacate) (polyamide 1010), poly(hexamethylene lauramide) (polyamide 612), poly(decamethylene lauramide) (polyamide 1012), poly(undecanamide) (polyamide 116), and mixtures or copolymers thereof.

[0101] Examples of aromatic polyamides include: polyhexamethylene isophthalamide (polyamide 6I), polyhexamethylene terephthalamide (polyamide 6T), polyhexamethylene terephthalamide / polyhexamethylene isophthalamide copolymer (polyamide 6T / 6I), polyhexamethylene terephthalamide / polyhexamethylene terephthalamide copolymer (polyamide 6 / 6T), polyhexamethylene terephthalamide / polyhexamethylene terephthalamide copolymer (polyamide 6 / 6I), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (polyamide 66 / 6T), and polyhexamethylene adipamide. Amide / polyhexamethylene isophthalamide copolymer (polyamide 66 / 6I), polytrimethylhexamethylene terephthalamide (polyamide TMDT), polybis(4-aminocyclohexyl)methane lauramide (polyamide PACM12), polybis(3-methyl-4-aminocyclohexyl)methane lauramide (nylon dimethyl PACM12), polyadipamide isophthalamide (polyamide MXD6), polydemoethylene terephthalamide (polyamide 10T), polyundemethylene terephthalamide (polyamide 11T), and mixtures or copolymers thereof.

[0102] Examples of amorphous polyamides include: condensation polymers of isophthalic acid / terephthalic acid / 1,6-hexanediamine / bis(3-methyl-4-aminocyclohexyl)methane, condensation polymers of terephthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine, condensation polymers of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam, and condensation polymers of isophthalic acid / terephthalic acid / 1,6-hexanediamine. Polymers, condensation polymers of isophthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine, condensation polymers of isophthalic acid / terephthalic acid / 2,2,4-trimethyl-1,6-hexanediamine / 2,4,4-trimethyl-1,6-hexanediamine, condensation polymers of isophthalic acid / bis(3-methyl-4-aminocyclohexyl)methane / ω-laurolactam, condensation polymers of isophthalic acid / terephthalic acid / other diamine components, etc.

[0103] Examples of polyamide elastomers include elastomers with polyamide as the hard segment, often referred to as amide thermoplastic elastomers. Examples include multiblock copolymers with polyamide as the hard segment and polyether or polyester as the soft segment, and multiblock copolymers with polyamide as the hard segment and soft segments having both ether and ester bonds. Examples of hard segments include polyamides 6, 66, 610, 11, and 12. Examples of polyethers in the soft segment include polyethylene glycol, poly(oxytetramethylene) glycol, and poly(propylene oxide) glycol; examples of polyesters include polyethylene adipate and 1,4-butanediol adipate.

[0104] Examples of commercially available polyamides that can be used in this invention include: polyamide 11 (manufactured by Arkema, trade name "RILSAN BMN O"), polyamide 12 (manufactured by Cadena Lu-Evonik, trade name "DAIAMID L1940"), polyamide 1010 (manufactured by Cadena Lu-Evonik, trade name "VESTAMID TerraDS16"), polyamide 1012 (manufactured by Evonik, trade name "VESTAMID TerraDD16"), amorphous polyamide (manufactured by Cadena Lu-Evonik, trade name "TROGAMIDCX7323"), and polyamide elastomers (manufactured by Arkema, trade names "PEBAX 4533", "PEBAX 7233", and "PEBAXRnew80R53").

[0105] Polyamides can be used alone or in combination of two or more.

[0106] (Polyester)

[0107] As a polyester, common polyesters that can be widely used as polymer coatings for flexible tubes used in endoscopes are widely applicable. Examples include thermoplastic polyesters and polyester elastomers.

[0108] Examples of thermoplastic polyesters include polyester resins composed of dicarboxylic acid and diol components, and polyester resins composed of hydroxycarboxylic acid components.

[0109] Examples of dicarboxylic acid components include: terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, sodium isophthalate-5-sulfonate, oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanoic acid, dimer acid, maleic anhydride, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesocarboxylic acid, cyclohexanedicarboxylic acid, etc.

[0110] In addition, examples of diols include: ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, cyclohexanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, polybutanediol, and ethylene oxide adducts of bisphenol A or bisphenol S.

[0111] Examples of hydroxycarboxylic acid components include: ε-caprolactone, lactic acid, and 4-hydroxybenzoic acid.

[0112] Thermoplastic polyester can be a homopolymer composed of the above-mentioned dicarboxylic acid components and diol components or a homopolymer composed of the above-mentioned hydroxycarboxylic acid components, or it can be a copolymer. Furthermore, it can also contain small amounts of trifunctional or higher-functional compounds such as trimellitic acid, pyromellitic acid, benzopyrene, trimethylolpropane, glycerol, and pentaerythritol.

[0113] Examples of polyester elastomers include elastomers with polyester hard segments, often referred to as ester thermoplastic elastomers. Examples of other elastomers include multiblock copolymers with crystalline polyester hard segments and polyether or polyester soft segments, and multiblock copolymers with crystalline polyester hard segments and soft segments having both ether and ester bonds.

[0114] Examples of hard segments include: polybutylene terephthalate and polyethylene terephthalate.

[0115] Examples of soft segments include: polyalkylene glycols such as polybutane glycol and polypropylene glycol, bisphenol A ethylene oxide adducts, bisphenol A propylene oxide adducts, and polyesters such as polycaprolactone.

[0116] As a polyester elastomer, block copolymers consisting 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 can be used, such as those described in Japanese Patent Application Publication No. 11-92636.

[0117] Examples of commercially available polyesters used in this invention include: polyester elastomers (manufactured by Toyobo Corporation under the trade names "PELPRENE P-40B", "PELPRENE P-70B" and "PELPRENE S-3001", and manufactured by Mitsubishi Chemical Corporation under the trade name "PRIMALLOYB1942") and polybutylene terephthalate (manufactured by Mitsubishi Engineering Plastics Corporation under the trade name "NOVADURAN 5505S").

[0118] Polyester can be used alone or in combination of two or more types.

[0119] (Polyurethane)

[0120] As polyurethane, common polyurethanes that can be used as polymer coatings for flexible tubes in endoscopes can be widely employed. Polyurethanes of the form of carbonates, ethers, esters, or mixtures thereof can be used. Polyurethane elastomers are also preferred. Examples of polyurethane elastomers include block polymers, also known as urethane thermoplastic elastomers, which are block polymers with polyurethane hard segments and soft segments having ether, ester, or carbonate bonds, or mixtures thereof, and can be appropriately prepared according to the purpose. Examples include block polymers comprising hard segments composed of low-molecular-weight diols and diisocyanates, and soft segments composed of high-molecular-weight (long-chain) diols and diisocyanates.

[0121] Examples of high molecular weight (long-chain) diols include: polyether diols, polyester diols, and lactone-based polyester diols. Examples include: polypropylene glycol, polybutane oxide, poly(1,4-butanediol adipate), poly(ethylene glycol adipate-co-1,4-butanediol adipate), polycaprolactone diols, poly(1,6-hexanediol carbonate), and poly(1,6-hexanediol adipate-co-neopentyl adipate). The number average molecular weight of the high molecular weight (long-chain) diol is preferably 500–10,000.

[0122] As low-molecular-weight diols, 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 diols is preferably 48–500.

[0123] Examples of diisocyanate components mentioned above include: diphenylmethane diisocyanate, hexamethylene diisocyanate, benzyltoluidine diisocyanate, 1,5-naphthalene diisocyanate, isophorone diisocyanate, phthalic acid diisocyanate, etc.

[0124] As for the polyurethane elastomer involved in the above embodiments, reference can be made to, for example, the disclosure of Japanese Patent Application Publication No. 2005-015643.

[0125] Examples of commercially available polyurethanes that can be used in this invention include: PANDEX T-2185, T-2983N (manufactured by DIC Corporation), Miractran (manufactured by Miractran Corporation of Japan), PANDEX (manufactured by DIC Corporation), Elastollan (manufactured by BASF Corporation of Japan), Resamine (manufactured by Dainisei Chemical Co., Ltd.), Pellethane (manufactured by Dow Chemical Co., Ltd. of Japan), IRON RUBBER (manufactured by NOK Corporation), MOBILON (manufactured by Nisshinbo Chemical Co., Ltd.), etc. Examples include: ISOPLAST (manufactured by Lubrizol Corporation), TECOFLEX (manufactured by Lubrizol Corporation), SUPERFLEX 830, 460, 870, 420 or 420NS (polyurethane manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), HYDRAN AP-40F, WLS-202 or HW-140SF (polyurethane manufactured by DIC Corporation), OLESTER UD500 or UD350 (polyurethane manufactured by Mitsui Chemicals Co., Ltd.), 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 Mitsui Chemicals Co., Ltd.), etc.

[0126] Polyurethane can be used alone or in combination of two or more types.

[0127] (Polyolefins)

[0128] As polyolefins, common polyolefins that can be widely used as polymer coatings for flexible tubes used in endoscopes are examples of polyolefin resins and olefin elastomers.

[0129] Examples of polyolefin resins or rubbers include homopolymers or copolymers of α-olefins with 2 to 20 carbon atoms, such as ethylene, propylene, 1-butene, 1-hexene, and 4-methyl-pentene. Other examples include copolymers of non-conjugated dienes with 2 to 20 carbon atoms, such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene, butadiene, and isoprene, with α-olefins. Furthermore, examples include ethylene-α-olefin copolymer rubbers, ethylene-α-olefin-non-conjugated diene copolymer rubbers, propylene-α-olefin copolymer rubbers, and butene-α-olefin copolymer rubbers. In addition, the following can also be used: ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester-(meth)acrylic acid copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-(meth)acrylic acid copolymer, ethylene-propylene-(meth)acrylic acid copolymer, ethylene-propylene-(meth)acrylic acid ester-(meth)acrylic acid copolymer, ethylene-maleic anhydride copolymer, ethylene-(meth)acrylic acid ester-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, and ethylene-vinyl chloride copolymer, etc.

[0130] Examples of polyolefins that are olefin elastomers include: ethylene-propylene copolymers, ethylene-1-butene copolymers, ethylene-α-olefin copolymers, propylene-1-butene copolymers, propylene-α-olefin copolymers, 1-butene-α-olefin copolymers, propylene-1-butene-ethylene copolymers, propylene-α-olefin-ethylene copolymers, propylene-α-olefin-1-butene copolymers, 1-butene-α-olefin-ethylene copolymers, and polypropylene.

[0131] Examples of rubber components in olefin elastomers include: propylene rubber (PP), ethylene-propylene rubber (EPM) and ethylene-propylene-diene rubber (EPDM), polyisoprene, polybutadiene, chloroprene rubber, and isobutylene-isoprene copolymer.

[0132] Olefin elastomers may contain only one type of polyolefin and one or more types of rubber components.

[0133] Examples of commercially available polyolefins used in this invention include: SARLINK 3145D (trade name, manufactured by Toyobo Co., Ltd.) and ZELAS MC707 (trade name, manufactured by Mitsubishi Chemical Co., Ltd.).

[0134] Polyolefins can be used alone or in combination of two or more.

[0135] When the polymer coating layer is a single layer, the total content of compounds selected from polyamide, polyester, polyurethane, and polyolefin in the polymer coating layer, and when the polymer coating layer is multilayer, the total content of compounds selected from polyamide, polyester, polyurethane, and polyolefin in the innermost layer, is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and even more preferably 90% by mass or more. Furthermore, when the polymer coating layer is a single layer, it can be a layer composed of at least one compound selected from polyamide, polyester, polyurethane, and polyolefin; and when the polymer coating layer is multilayer, the innermost layer can be a layer composed of at least one compound selected from polyamide, polyester, polyurethane, and polyolefin.

[0136] When the polymer coating is a single layer, or when the innermost layer of the polymer coating is a multilayer layer, contains a polymer other than that selected from polyamide, polyester, polyurethane and polyolefin, the polymer is not particularly limited as long as it does not impair the effect of the present invention.

[0137] Furthermore, the polymer coating may appropriately contain various commonly used additives within a range that does not impair the effects of the present invention. Examples of such additives include, for instance, heat stabilizers, inorganic fillers, impact modifiers, plasticizers, lubricants, metallic soaps, lightfastness agents, and colorants. The content of the above-mentioned additives in the polymer coating can also be appropriately adjusted. Such additives may be derived from the polymer material used, or they may be added separately from the polymer.

[0138] When the polymer coating is multilayered, the layers other than the innermost layer preferably contain at least one compound selected from polyamide, polyester, polyurethane, and polyolefin. These polymers can be appropriately combined to form layers with desired properties. Furthermore, the total content of compounds selected from polyamide, polyester, polyurethane, and polyolefin in the layers other than the innermost layer has the same meaning as the total content of the innermost layer.

[0139] The polymers used in the polymer coatings of the present invention preferably have a molecular weight of 10,000 to 1,000,000, more preferably a molecular weight of 20,000 to 500,000, and particularly preferably a molecular weight of 30,000 to 300,000.

[0140] In this invention, unless otherwise specified, the molecular weight of the polymer constituting the polymer coating refers to the weight-average molecular weight. The weight-average molecular weight can be measured as the molecular weight converted from polystyrene by gel permeation chromatography (GPC).

[0141] like Figure 2As shown, in this invention, the polymer coating 15 is preferably formed with a substantially uniform thickness along the longitudinal direction (axial direction) of the flexible tube substrate 14. The thickness of the polymer coating 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, 11 to 14 mm. Figure 2 In this design, the thicknesses of the inner layer 17 and the outer layer 18 are formed such that, along the axial direction of the flexible tube substrate 14, the thickness ratio of each layer 17 and 18 varies relative to the overall thickness of the polymer coating layer 15. Specifically, at one end 14a (top end side) of the flexible tube substrate 14 mounted on the bend 3b, the thickness of the inner layer 17 is greater than the thickness of the outer layer 18 relative to the total thickness of the polymer coating layer 15. Furthermore, from one end 14a toward the other end 14b (base end side) mounted on the main operating part 5, the thickness of the inner layer 17 gradually decreases, while at the other end 14b, the thickness of the outer layer 18 is greater than the thickness of the inner layer 17.

[0142] exist Figure 2 In the flexible tube 3a, the thickness ratio of the inner layer 17 is the largest at one end 14a, while the thickness ratio of the outer layer 18 is the largest at the other end 14b. The thickness ratio of the inner layer 17 to the outer layer 18 can be, for example, 9:1 at one end 14a and, for example, 1:9 at the other end 14b. By changing the thickness of the two layers, the thickness ratio of the inner layer 17 to the outer layer 18 is reversed from both ends 14a to 14b. This creates a difference in hardness between the one end 14a side and the other end 14b side, allowing the flexibility to vary axially by making one end 14a side softer and the other end 14b side harder. Preferably, the thickness ratio of the inner and outer layers at one end is 95:5 to 60:40 (inner layer:outer layer), and preferably the thickness ratio at the other end is 5:95 to 40:60 (inner layer:outer layer).

[0143] Furthermore, by setting the thickness ratio of the inner layer 17 to the outer layer 18 within the range of 95:5 to 5:95, the extrusion amount of the polymer on the thinner side can also be precisely controlled.

[0144] The soft and hard polymers used in the inner layer 17 and outer layer 18 preferably have a difference of 100% modulus values, which is an indicator of the hardness after molding, of 1 MPa or more, more preferably 3 MPa or more. The difference in melt viscosity at molding temperatures of 150°C to 300°C, which is an indicator of the fluidity of the polymer in the molten state, is preferably 2500 Pa·s or less. Thus, the polymer coating layer 15 composed of the inner layer 17 and outer layer 18 can ensure both good molding accuracy and the required hardness difference between the top and bottom sides.

[0145] <Top Coating>

[0146] In the flexible tube of the present invention, a coating 16 is disposed on the outer periphery of the polymer coating layer 15 as needed. The material of the coating is not particularly limited, and urethane coatings, acrylic coatings, fluoropolymer coatings, silicone coatings, epoxy coatings, polyester coatings, etc. can be used.

[0147] The main purpose of using a top coating is to protect or polish the surface of the flexible tube, impart lubrication, and provide chemical resistance. Therefore, a top coating with high elasticity, a smooth surface, and excellent chemical resistance is preferred.

[0148] [Manufacturing method of flexible tube]

[0149] <Formation of Porous Layers>

[0150] In the manufacture of the flexible tube of the present invention, a porous layer is formed on the flexible tube substrate. The formation of the porous layer can be referenced, for example, Japanese Patent Application Publication No. 2010-77358, Japanese Patent Application Publication No. 2013-18966, Japanese Patent Application Publication No. 2010-64932, International Patent Application Publication No. 2003 / 028097, International Patent Application Publication No. 2003 / 075335, Japanese Patent Application Publication No. 2003-115486, Japanese Patent Application Publication No. 2005-202240, Japanese Patent Application Publication No. 2003-268356 and International Patent Application Publication No. 2008 / 093731.

[0151] The manufacturing method of the flexible tube of the present invention preferably includes forming a porous layer with an average pore size of 50 nm to 100 μm. As described below, the average pore size of the porous layer can be controlled by the raw material of the porous layer, etc.

[0152] The following describes in detail the methods for forming each layer of the epoxy resin porous layer and the silica porous layer. Furthermore, the following description is merely an example, and the formation of the porous layer in this invention is not limited to these forms.

[0153] (Methods for forming porous silica layers)

[0154] The porous silica layer can be formed on the flexible tube substrate (outer periphery) through the processes described in (i) and (ii) below.

[0155] (i) A silica composition is prepared by dehydration condensation reaction of alkoxysilane compounds in the presence of a pore-forming agent.

[0156] (ii) After coating a flexible tube substrate with a silica composition, the silica composition is dried (or heated) to form a coating film, and then heated at a high temperature to decompose and remove the pore-forming agent, thereby forming pores on the coating film.

[0157] In step (i) above, the alkoxysilane compound is subjected to a dehydration condensation reaction in a mixture containing an alkoxysilane compound, a pore-forming agent and a solvent to obtain a silica composition.

[0158] For example, an alkoxysilane compound, a pore-forming agent, and a solvent containing water are mixed, and a catalyst (described later) is added as needed. While mixing, the alkoxysilane compound undergoes a dehydration condensation reaction in the presence of the pore-forming agent. The mixture is then concentrated or diluted with a solvent as needed to obtain a silica composition. The reaction conditions (reaction temperature, reaction time) for the dehydration condensation reaction can be performed using conventional methods.

[0159] Alkoxysilane compounds are not particularly restricted, and tetraalkoxysilane compounds, trialkoxysilane compounds, and dialkoxysilane compounds can be used appropriately.

[0160] The aforementioned tetraalkoxysilanes are not particularly limited, and examples include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, and tetrabutoxysilane.

[0161] Examples of trialkoxysilane compounds include methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, and phenyltriethoxysilane.

[0162] Examples of dialkoxysilane compounds include dimethyldimethoxysilane and dimethyldiethoxysilane.

[0163] The total silica content (content of the above-mentioned dehydration condensation reactants) in the silica composition is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.5% by mass or more, and even more preferably 1% by mass or more. On the other hand, the total content of the above-mentioned silane compounds is preferably 70% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, and even more preferably 20% by mass or less.

[0164] As a pore-forming agent, a pore-forming agent contained within silica and capable of being decomposed and removed by heating can be used. Examples of pore-forming agents include surfactants. Nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants can be used; nonionic surfactants are preferred, and polymeric nonionic surfactants are more preferred. When the surfactant is a polymer, its number-average molecular weight is, for example, 300 to 5000.

[0165] The surfactant content in the silica composition is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 1.2% by mass or more, and even more preferably 1.4% by mass or more. On the other hand, the above-mentioned content is preferably 50% by mass or less, more preferably 40% by mass or less, and particularly preferably 30% by mass or less.

[0166] As a solvent, water or a combination of water and a water-soluble organic solvent is preferred. Examples of water-soluble organic solvents include: monohydric alcohols with 1 to 5 carbon atoms such as methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-1-propanol, 1-butanol, 2-butanol, tert-butanol, and 1-pentanol; dihydric alcohols with 1 to 4 carbon atoms such as glycerol and pentaerythritol; ethers or esters of the above alcohols such as methyl acetate, ethyl acetate, isobutyl acetate, diethylene glycol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, 2-ethoxyethanol, propylene glycol monomethyl ether, and propylene glycol methyl ether acetate; ketones such as acetone and methyl ethyl ketone; and formamide, N-methyl... Amide compounds such as 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'-diacetylpiperazine, etc.; lactone compounds such as γ-butyrolactone; ureas such as tetramethylurea and N,N'-dimethylimidazoline; and dimethyl sulfoxide, etc. Among these, alcohols are preferred, and monohydric alcohols are more preferred, in order to allow for hydrolysis under more stable conditions compared to the contained alkoxysilane compounds.

[0167] Silica compositions typically contain a catalyst. The catalyst can be any substance that promotes the hydrolysis and dehydration condensation reactions of alkoxysilane compounds.

[0168] Examples include: 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, succinic acid, etc.; amine compounds such as ammonia, butylamine, dibutylamine, triethylamine, etc.; bases such as pyridine; Lewis acids such as aluminum acetylacetone complexes; etc.

[0169] In addition, metal chelate compounds can be cited as examples of catalysts. Examples of metals that can be used in such chelate compounds include titanium, aluminum, zirconium, tin, and antimony.

[0170] Within the scope of not impairing the effects of the present invention, the silica composition may also contain components other than the alkoxysilane compounds, organic solvents, surfactants, water, and catalysts mentioned above.

[0171] In step (ii) above, the flexible tube substrate is immersed in the silica composition obtained in step (i) above, and then the flexible tube substrate is removed and dried to form a coating film. Next, the surfactant is decomposed and removed at a high temperature (e.g., above 250°C), thereby obtaining a flexible tube substrate having a porous silica layer.

[0172] The average pore size and porosity of the silica porous layer can be controlled by the type of raw material, the ratio of raw material to raw material, and reaction conditions (e.g., drying or heating temperature and heating time).

[0173] (Methods for forming porous layers of epoxy resin)

[0174] The epoxy resin porous layer can be formed on the flexible tube substrate (outer periphery) through the following processes (1) to (3).

[0175] (1) Prepare a mixture containing epoxy resin, pore-forming agent, solvent and epoxy resin curing agent.

[0176] (2) After coating the above mixture onto the flexible tube substrate and drying it, heat it to react the epoxy resin with the curing agent.

[0177] (3) Remove the pore-forming agent from the cured epoxy resin.

[0178] In step (1) above, a mixture comprising epoxy resin, curing agent and pore-forming agent is prepared. The mixing is carried out at room temperature (e.g., 25-30°C) or at a temperature lower than room temperature for about 5-30 minutes to obtain a homogeneous mixture.

[0179] As an epoxy resin, both aromatic epoxy resins and non-aromatic epoxy resins can be used.

[0180] Examples of aromatic epoxy resins include: polyphenyl epoxy resins, epoxy resins containing fluorene rings, epoxy resins containing triglycidyl isocyanurate, and epoxy resins containing heteroaromatic rings (e.g., triazine rings).

[0181] Examples of polyphenyl epoxy resins include: bisphenol A type epoxy resin, ozonated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD ​​type epoxy resin, stilbene type epoxy resin, biphenyl type epoxy resin, bisphenol A phenolic varnish type epoxy resin, cresol phenolic varnish type epoxy resin, diaminodiphenylmethane type epoxy resin, and tetra(hydroxyphenyl)ethane type epoxy resin.

[0182] Examples of non-aromatic epoxy resins include: aliphatic glycidyl ether type epoxy resin, aliphatic glycidyl ester type epoxy resin, alicyclic glycidyl ether type epoxy resin, alicyclic glycidyl amine type epoxy resin, and alicyclic glycidyl ester type epoxy resin.

[0183] The epoxy resins mentioned above can be used alone or in combination of two or more.

[0184] Common curing agents used in epoxy resin curing, such as amine compounds, acid anhydrides, and imidazole compounds, can be used as curing agents. Examples of amine compounds include 1,6-diaminohexane, 1,4-diaminobutane, and 1,8-diaminooctane. These curing agents can be used alone or in combination.

[0185] The content of curing agent in the mixture of step (1) relative to the epoxy resin ratio, for example relative to the epoxy group 1 equivalent of the epoxy resin, is preferably 0.1 to 1.5, more preferably 0.2 to 1.0.

[0186] Specific examples of pore-forming agents include: cellosol compounds such as methyl cellosol and ethyl cellosol; ester compounds such as ethylene glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate; glycol compounds such as polyethylene glycol and polypropylene glycol; and ether compounds such as polyoxyethylene monomethyl ether and polyoxyethylene dimethyl ether. These pore-forming agents can be used alone or in combination of two or more.

[0187] In the total content of epoxy resin, curing agent and pore-forming agent, the content ratio of pore-forming agent can be set to, for example, 10 to 80 by mass.

[0188] The solvents mentioned above are solvents that can dissolve components such as epoxy resin, curing agent, and pore-forming agent. Preferred solvents include organic solvents such as methyl ethyl ketone, acetone, toluene, cyclohexanone, and MIBK (methyl isobutyl ketone).

[0189] In step (2) above, the flexible tube substrate is immersed in the mixture obtained in step (1) above, and the mixture is applied to the surface of the flexible tube substrate. Then, the solvent is removed by drying, for example, by heating at about 60 to 120°C for 30 minutes to 4 hours, thereby forming an epoxy resin layer on the flexible tube substrate.

[0190] In the above process (3), the flexible tube substrate is immersed in a solvent that dissolves the pore-forming agent but not the epoxy resin, and ultrasonic treatment is performed as needed to remove the pore-forming agent from the epoxy resin layer. Examples of solvents that dissolve the pore-forming agent but not the epoxy resin include water or a mixture of water and at least one of DMF (N,N-dimethylformamide), DMSO (dimethyl sulfoxide), and THF (tetrahydrofuran).

[0191] The average pore size and porosity of epoxy resin porous layers can be controlled by the type of raw materials, the mixing ratio of raw materials, and reaction conditions (e.g., heating temperature and heating time during reaction-induced phase separation).

[0192] In this invention, to the extent that the effects of the invention are not compromised, a portion of the outer periphery of the flexible tube substrate may be not covered by the porous layer (i.e., a portion of the porous layer may have voids).

[0193] Preferably, before the porous layer is formed, the flexible tube substrate is pre-cleaned using an acid or alkali solution, an aqueous surfactant solution, an organic solvent, or the like. Furthermore, it is preferable to further pre-clean with water or warm water after the above cleaning to reduce the amount of acid or alkali and surfactants from the substrate surface.

[0194] <Formation of the primer layer>

[0195] In the manufacture of the flexible tube substrate of the present invention, after forming a porous layer, a primer layer is formed on the porous layer. The primer layer can be formed 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, applying or spraying the coating solution onto the outer periphery of the flexible tube substrate, or immersing the flexible tube substrate in the coating solution, thereby forming a coating film at least on the outer periphery of the flexible tube substrate, and then drying the coating film by a common method (e.g., high-temperature drying at around 100°C).

[0196] As solvents for 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 mixtures of these solvents, can be used. Furthermore, to promote the hydrolysis of silane coupling agents, titanium coupling agents, zirconium coupling agents, and aluminum coupling agents, a mixture of these solvents with water or an acid catalyst such as acetic acid is preferred. Additionally, the coating solution can be prepared as acidic (e.g., pH 1–4 at 25°C) or alkaline (e.g., pH 9–11 at 25°C).

[0197] The content of 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 set to 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.

[0198] The coating solution may contain surfactants, catalysts, etc., in addition to at least one of silane coupling agents, titanium coupling agents, zirconium coupling agents, and aluminum coupling agents, a solvent, and a pH adjuster. More preferably, the coating solution is composed of at least one of silane coupling agents, titanium coupling agents, zirconium coupling agents, and aluminum coupling agents, and a solvent.

[0199] In this invention, to the extent that the effects of the invention are not compromised, a portion of the porous layer may be uncovered by the primer layer (i.e., a portion of the primer layer may have voids).

[0200] <Formation of Polymer Coating>

[0201] The formation of the polymer coating will be explained using the case where the polymer coating has a double-layer structure as an example.

[0202] A flexible tube with a double-layer structure consisting of an inner layer and an outer layer can be obtained, for example, by melting and mixing a first polymer material (a polymer material comprising at least one compound selected from polyamide, polyester, polyurethane and polyolefin) constituting the inner layer and a second polymer material constituting the outer layer and extruding them around the flexible tube substrate after the primer layer has been formed, thereby coating the flexible tube substrate.

[0203] In addition, polymer coatings of one or more layers can also be obtained by appropriately modifying the layer structure, referring to the methods described below.

[0204] based on Figure 3 , Figure 4 For flexible tube 3a ( Figure 1 , Figure 2 An example of a method for forming a polymer coating 15 will be described. In this method, a continuous molding machine is used to form the polymer coating 15. The continuous molding machine 20 is preferably a molding machine composed of the following components: well-known extrusion sections 21 and 22, such as hoppers, screws 21a and 22a; a head 23 for coating the polymer coating 15 onto the outer peripheral surface of the flexible tube substrate 14; a cooling section 24; a conveying section 25 (feeding cylinder 28 and winding cylinder 29) for conveying the flexible tube substrate 31 to the head 23; and a control section 26 for controlling these components. The head 23 is preferably composed of a pipe joint 32, a die head 33, and a support body 34 for fixing and supporting these components. As an example of the configuration of the device described above, the one disclosed in Japanese Patent Application Publication No. 2011-72391 can be used. Figure 3 The device described in section 5.

[0205] Preferably, the interior of the die head 33 is heated to a predetermined molding temperature. The molding temperature is preferably set in the range of 150°C to 300°C. By heating and adjusting the temperature of the heating element within the device, the temperatures of the first polymer material 39 and the second polymer material 40 can be raised to high temperatures. Furthermore, the higher the rotational speeds of the screws 21a and 22a, the higher the temperatures of the first polymer material 39 and the second polymer material 40 can be, and their fluidity can be improved. At this time, by keeping the conveying speed of the connecting flexible tube substrate 31 constant and changing the ejection 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.

[0206] The process of molding a polymer coating layer 15 onto a flexible tube substrate 31 using a continuous molding machine 20 will be described. During the molding process, the continuous molding machine 20 extrudes molten first polymer material 39 and second polymer material 40 from extrusion sections 21 and 22 towards the head 23. Simultaneously, the conveying section 25 operates, conveying the flexible tube substrate 31 towards the head 23. At this time, extrusion sections 21 and 22 are in a state of continuously extruding and supplying the first polymer material 39 and second polymer material 40 to the head 23. The first polymer material 39 and second polymer material 40 extruded from extrusion sections 21 and 22 towards gates 35 and 36 converge at the edges and are supplied to the molding channel 37 through the polymer channel 38 in an overlapping state. Thus, a double-layered polymer coating layer 15 is formed, consisting of an inner layer 17 using the first polymer material 39 and an outer layer 18 using the second polymer material 40 overlapping.

[0207] The connecting flexible tube substrate 31 is a substrate formed by connecting multiple flexible tube substrates 14 (each of which has a porous layer and a primer layer formed on its outer periphery). During transport within the forming channel 37, polymer coating layers 15 are continuously formed on the multiple flexible tube substrates 14. When forming the polymer coating layer 15 from one end 14a (top side) of a flexible tube substrate to the other end 14b (base side), the inner layer 17 is thickened immediately after the polymer is extruded using the extrusion sections 21 and 22. Then, the thickness ratio of the outer layer 18 is gradually increased in the middle portion towards the other end 14b. Therefore, it is preferable to control the amount of polymer extruded to form the aforementioned gradient thickness ratio of the polymer coating layer 15.

[0208] Since the connector 30 is the connecting part of the two flexible tube substrates 14, the control unit 26 is used to switch the ejection volume of the extrusion sections 21 and 22. Specifically, the control unit 26 preferably switches the ejection volume of the extrusion sections 21 and 22 so that the thickness ratio on the other end 14b side (base end side) of one flexible tube substrate 14 changes to the thickness ratio on the one end 14a side (top end side) of the next flexible tube substrate 14. When molding the polymer coating layer 15 from one end 14a side to the other end 14b side of the next flexible tube substrate 14, it is also preferable to control the extrusion sections 21 and 22 so that the thickness of the outer layer gradually increases from one end side to the other end side.

[0209] After the polymer coating layer 15 is formed to its final end and the connecting flexible tube substrate 31 is removed from the continuous forming machine 20, the connector component 30 is removed from the flexible tube substrate 14, separating them into individual flexible tube substrates 14. Then, a coating layer 16 is applied to the separated flexible tube substrates 14 on the polymer coating layer 15 to complete the flexible tube 3a. The completed flexible tube 3a is then conveyed to the assembly process of the electronic endoscope.

[0210] In this invention, when the polymer coating is multilayered, functional layers may be sandwiched between the layers constituting the multilayer.

[0211] The above description refers to the accompanying drawings and uses an electronic endoscope as an example to observe an image of the state of an object captured by a camera device. However, the present invention is not limited thereto and can also be applied to endoscopes that use optical image guides to observe the state of an object.

[0212] The flexible tube of this invention can be widely used in endoscopic medical devices. For example, it can also be used in instruments with clamps or wires at the tip of an endoscope, or in devices with baskets or brushes. Furthermore, endoscopic medical devices are defined not only as medical devices with an endoscope as their basic structure, but also broadly include medical or diagnostic devices with flexible insertion parts that are inserted into the body, such as remotely operated medical devices.

[0213] The endoscopic medical device of the present invention has an endoscope flexible tube of the present invention assembled in its insertion portion. That is, the method of manufacturing the endoscopic medical device of the present invention includes assembling the endoscope flexible tube of the present invention into the insertion portion of the endoscopic medical device.

[0214] [Example]

[0215] The present invention will be further described in detail below through embodiments, but the present invention is not limited to these embodiments.

[0216] [Fabrication of Flexible Tubes for Endoscopes]

[0217] Production Figure 2 The flexible tube shown has the following structure. Furthermore, the polymer coating, as shown in Table 3 below, can be either a single-layer or double-layer structure.

[0218] Flexible tube substrate

[0219] A flexible tube substrate is prepared as follows: a spiral tube 11 is formed using a stainless steel (SUS304) metal strip 11a, and this spiral tube 11 is covered with a tubular mesh 12 woven with SUS304 fibers. The flexible tube substrate has a length of 80 cm and a diameter of 12 mm. A passivation layer is formed on the surface of the stainless steel flexible tube substrate through an annealing treatment (heat treatment) during the formation of the spiral tube and the tubular mesh.

[0220] After degreasing the flexible tube substrate with acetone, it was immersed in a 1N sodium hydroxide aqueous solution at 50°C for 3 minutes. Then, it was rinsed three times with distilled water and dried in an oven heated to 100°C for 10 minutes to prepare the flexible tube substrate.

[0221] <Formation of the porous epoxy resin layer (L-1)>

[0222] In a stainless steel container, 10.0 g of bisphenol A type epoxy resin (Mitsubishi Chemical Corporation "jER828" (trade name), epoxy equivalent 184-194 g / eq.), 4.0 g of polyethylene glycol (Sanyo Chemical Corporation "SANNIX PEG-400" (trade name)), and 1950.0 g of methyl ethyl ketone (MEK) were mixed to prepare an epoxy resin / polyethylene glycol MEK solution. Then, 15.0 g of 1,6-diaminohexane was added to this solution, and the mixture was stirred at room temperature for 15 minutes using a three-one motor to obtain epoxy resin solution (D).

[0223] The cleaned flexible tube substrate was immersed in epoxy resin solution (D) for 5 minutes, then lifted out and air-dried at 40°C for 30 minutes to allow methyl ethyl ketone to evaporate. The flexible tube substrate was then heated in an oven at 100°C for 3 hours to form an epoxy resin layer on the outer periphery of the flexible tube substrate.

[0224] Next, the flexible tube substrate with the epoxy resin layer formed thereon is ultrasonically cleaned in a 1 / 1 (v / v) mixture of distilled water and dimethylformamide for 10 minutes, then ultrasonically cleaned with distilled water for 10 minutes, and then immersed in distilled water for 12 hours to remove the polyethylene glycol contained therein.

[0225] Subsequently, drying was carried out at 80°C for 2 hours to form an epoxy resin porous layer (L-1) on the outer periphery of the flexible tube substrate.

[0226] <Formation of porous epoxy resin layers (L-2) to (L-9)>

[0227] Except for the components described in Table 1 below, epoxy resin porous layers (L-2) to (L-9) are formed on the outer periphery of the flexible tube substrate in the same manner as for the epoxy resin porous layer (L-1). That is, each flexible tube substrate having an epoxy resin porous layer (L-2) to (L-9) on its outer periphery is obtained.

[0228] <Formation of the porous silica layer (L-10)>

[0229] In a stainless steel container, 1,000 g of hydrolyzed silicate (HAS-1, manufactured by COLCOAT, Japan, with a solid content of 21% by mass and 2-propanol / ethanol / methanol solvent), 45 g of polyethylene glycol (SANNIX PEG-400, manufactured by Sanyo Chemicals, Japan, with a solid content of 21% by mass and 2-propanol / ethanol / methanol solvent), 955 g of isopropyl alcohol were mixed to obtain a silica composition (a).

[0230] The cleaned flexible tube substrate was immersed in the silica composition (a) for 5 minutes, then lifted out and air-dried at 40°C for 30 minutes to allow the solvent to evaporate. The flexible tube substrate was then heated in an oven at 100°C for 10 minutes to form a silica layer on the outer periphery of the flexible tube substrate.

[0231] Next, the flexible tube substrate with the silica layer formed thereon is ultrasonically cleaned in a 1 / 1 (v / v) mixture of distilled water and dimethylformamide for 10 minutes, then ultrasonically cleaned with distilled water for 10 minutes, and then immersed in distilled water for 12 hours to remove the polyethylene glycol contained therein.

[0232] Subsequently, drying was carried out at 80°C for 2 hours to form a porous silica layer (L-10) on the outer periphery of the flexible tube substrate.

[0233] <Formation of porous silica layers (L-11) to (L-13)>

[0234] Except for the components described in Table 2 below, the same procedure as for the porous silica layer (L-10) is followed to form porous silica layers (L-11) to (L-13) on the outer periphery of the flexible tube substrate. That is, each flexible tube substrate having a porous silica layer (L-11) to (L-13) on its outer periphery is obtained.

[0235] <Formation of the non-porous epoxy layer (R-1)>

[0236] In the formation of the above-mentioned porous epoxy layer (L-1), except that polyethylene glycol is not used, a non-porous epoxy resin layer (R-1) is formed in the same manner.

[0237] <Formation of the non-porous silica layer (R-2)>

[0238] In the formation of the above-mentioned porous silica layer (L-10), except that polyethylene glycol is not used, a non-porous silica layer (R-2) is formed in the same manner.

[0239] Determine and calculate the average pore size, porosity, and average layer thickness of the porous layer using the following procedures. The results are shown in Tables 1 and 2 below.

[0240] <Average pore size, porosity>

[0241] The flexible tubes, after being placed in an oven set to 150°C for 4 hours and then allowed to stand in a desiccator to room temperature, were used for measurement.

[0242] The porosity was determined using mercury intrusion porosimetry with a Micromeritics Pore-Sizer 9320 (trade name). The initial pressure was set at 20 kPa, the pore size at 3 nm to 400 μm, the measurement mode was pressurization (injection), and the cell volume was approximately 6 cm³. 3 Mercury contact angle 130°, mercury surface tension 484 dyn / cm.

[0243] <Average layer thickness>

[0244] The flexible tube substrate fabricated above was randomly cut at five points. The cross-section of each porous layer was observed at 50,000x magnification using a scanning electron microscope (S-5500 (trade name), manufactured by Hitachi High Technology Co., Ltd.). The thickness of the porous layer formed on the outer periphery was obtained at each point on each cross-section. The average value was calculated from the five obtained values.

[0245] [Table 1]

[0246]

[0247] [Table 2]

[0248]

[0249] <Notes to Tables 1 and 2>

[0250] The unit of measurement is "g".

[0251] jER828: Bisphenol A type epoxy resin (Mitsubishi Chemical manufactures "jER828" (trade name), epoxy equivalent 184-194 g / eq.)

[0252] HAS-1: Trade name, manufactured by COLCOAT Co., Ltd., Japan; solid content 21% by mass; solvent: 2-propanol / ethanol / methanol.

[0253] PEG: Polyethylene glycol (Sanyo Chemicals manufactures "SANNIX PEG-400" (trade name))

[0254] PP-400: Polypropylene glycol (Sanyo Chemicals manufactures "SANNIX PP-400" (trade name)).

[0255] PP-1000: Polypropylene glycol (Sanyo Chemicals manufactures "SANNIX PP-1000" (trade name)).

[0256] PP-3000: Polypropylene glycol (Sanyo Chemicals manufactures "SANNIX PP-3000" (trade name)).

[0257] DAH: 1,6-Diaminohexane

[0258] MEK: Methyl ethyl ketone

[0259] IPA: Isopropyl alcohol

[0260] <Formation of the primer layer>

[0261] Mix 150g of ethanol, 350g of water, and 1.0g of N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (S-1, trade name: KBM-603, manufactured by Shin-Etsu Chemical Co., Ltd.) to prepare a coating solution for primer layer formation.

[0262] The flexible tube substrate with a porous layer is immersed in the coating liquid for forming the primer layer prepared above at room temperature for 1 minute, air-dried for 10 minutes, and then placed in an oven at 100°C for 10 minutes to dry, thereby preparing a flexible tube substrate with a primer layer on the porous layer (the flexible tube substrate used in Example 1).

[0263] Following the same procedure as described above, the flexible tube substrates used in each embodiment and comparative example were prepared using the coupling agents listed in Table 3. Furthermore, in the comparative examples, an intermediate layer was formed instead of the porous layer of the embodiments. Additionally, no primer layer was formed in Comparative Example 4.

[0264] <Formation of Polymer Coating>

[0265] A flexible endoscope tube with a polymer coating is fabricated by extruding a polymer as described in Tables 3 (3-1 and 3-2) onto the outer periphery of a flexible tube substrate with a primer layer on a porous layer. The polymer coating is 0.4 mm thick (in the case of a double-layer structure, the combined thickness of the two layers is 0.4 mm).

[0266] Furthermore, when the polymer coating is configured as a two-layer structure (Examples 1-36, 44-51, Comparative Examples 1-4, 6-8), both layers are simultaneously coated using bilayer extrusion molding. In this case, the ratio of the inner to outer layer at the top and rear ends is set to inner layer:outer layer = 80:20 at the top and inner layer:outer layer = 20:80 at the rear. The thicknesses of the inner and outer layers form a gradient from the top to the rear.

[0267] The following tests were conducted on the fabricated flexible tube. The results are summarized in Table 3 below.

[0268] [Experimental Example 1] Evaluation of the resilience of flexible tubes

[0269] Under conditions of 25°C and 50% relative humidity, the flexible endoscope tube fabricated above was fixed at positions 30cm and 50cm from one end. The tube at 40cm (the center of the flexible tube) was then pressed in 15mm along a direction perpendicular to the length of the flexible tube (diameter direction). The ratio of the repulsive force (b) after 30 seconds to the repulsive force (a) after 0.1 seconds was calculated as the resilience (%). The repulsive force was measured using a force gauge (ZTS50N (trade name), manufactured by IMADA).

[0270] [Resilience (%)] = [(b) / (a)] × 100

[0271] Evaluate the above resilience against the following evaluation criteria. A score of "C" or above is considered acceptable.

[0272] <Resilience Evaluation Standard>

[0273] A: Resilience is above 80%.

[0274] B: Resilience is above 75% and below 80%.

[0275] C: Resilience is above 65% and below 75%.

[0276] D: Resilience is below 65%

[0277] [Experimental Example 2] Evaluation of the bending durability (tightness) of flexible tubes

[0278] The flexible tube of the endoscope, as described above, is brought into contact with half of a 7cm diameter pulley in a U-shape. It is then moved back and forth, reaching a position approximately 3.5cm in front of the pulley end at both the top and rear ends. The condition of the polymer coating is visually observed. The number of reciprocating motions resulting in lifting, cracking, or peeling of the polymer coating is evaluated against the following criteria. A grade of "C" or higher is considered acceptable.

[0279] <Bending Durability Evaluation Standard>

[0280] A: More than 10,000 times

[0281] B: More than 1,000 times but less than 10,000 times

[0282] C: More than 100 times but less than 1,000 times

[0283] D: Less than 100 times

[0284] [Experimental Example 3] Evaluation of the thermal cycling resistance of flexible tubes

[0285] The flexible endoscope tube fabricated above was subjected to a 500-cycle thermal cycling test using a constant temperature and humidity chamber (KHWV-40HP, Satake Chemical Machinery Co., Ltd.). Each cycle consisted of 2 hours at 0°C and 2 hours at 60°C. After 500 cycles of thermal cycling, the flexible endoscope tube was inserted in the same manner as in Test Example 1, and the repulsive force (c) was measured 0.1 seconds later. The ratio of the repulsive force (c) to the repulsive force (a) measured before the thermal cycling test in the same manner as in Test Example 1 was calculated as the repulsive force retention rate (%).

[0286] [Repulsion retention rate (%)] = [(c) / (a)] × 100

[0287] The repulsion retention rate described above should be evaluated against the following evaluation criteria. A score of "C" or above is considered acceptable.

[0288] <Evaluation Standard for Thermal Cycling Resistance>

[0289] A: The repulsion retention rate is over 90%.

[0290] B: Repulsion retention rate is above 70% but below 90%.

[0291] C: Repulsion retention rate is above 50% but below 70%.

[0292] D: Repulsion retention rate is less than 50%.

[0293] [Table 3-1]

[0294]

[0295]

[0296] [Table 3-2]

[0297]

[0298]

[0299] *1 No pores observed

[0300] <Notes to Table 3>

[0301] The abbreviations recorded in the table above are shown below.

[0302] Example: Implementation

[0303] Comparison: Example

[0304] (Silane coupling agent)

[0305] (S-1):

[0306] N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane (trade name: KBM-603, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0307] (S-2):

[0308] 3-Aminopropyltrimethoxysilane (trade name: KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0309] (S-3):

[0310] N-Methylaminopropyltrimethoxysilane (reagent)

[0311] (S-4):

[0312] 3-Uretopropyltrialkoxysilane (trade name: KBE-585, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0313] (S-5):

[0314] N-Phenylacetyl-3-aminopropyltrimethoxysilane (trade name: KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0315] (S-6):

[0316] 3-Trimethoxysilylpropylsuccinic anhydride (trade name: X-12-967C, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0317] (S-7):

[0318] (3-Methacryloxypropyl)trimethoxysilane (trade name: KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0319] (S-8):

[0320] 3-Epoxypropoxypropyltrimethoxysilane (trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0321] (S-9):

[0322] 3-Mercaptopropyltrimethoxysilane (trade name: KBM-803, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0323] (Aluminum coupling agent)

[0324] (A-1):

[0325] Aluminum sec-butoxide (trade name: ASBD, manufactured by Sichuan Research Institute of Fine Chemicals Co., Ltd.)

[0326] (A-2):

[0327] Aluminum triacetylacetonate (trade name: ORGATICS AL-3100, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0328] (A-3):

[0329] Ethyl diacetate, aluminum monoacetylacetonate (trade name: ORGATICS AL-3200, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0330] (A-4):

[0331] Ethyl triacetate aluminum (trade name: ORGATICS AL-3215, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0332] (A-5):

[0333] Aluminum diisopropoxide octadecyl acetoacetate (trade name: PLENACT AL-M, manufactured by Aj inomoto Fine-Techno Co., Inc.)

[0334] (Zirconium coupling agent)

[0335] (Z-1):

[0336] Tetra-n-propanezirconium (trade name: ORGATICS ZA-45, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0337] (Z-2):

[0338] Zirconium tetrabutoxide (trade name: ORGATICS ZA-65, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0339] (Z-3):

[0340] Zirconium tetraacetylacetonate (trade name: ORGATICS ZC-150, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0341] (Z-4):

[0342] Zirconium lactate (trade name: ORGATICS ZC-300, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0343] (Z-5):

[0344] Tri-n-Butyl Zirconium Stearate (trade name: ORGATICS ZC-320, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0345] (Titanium coupling agent)

[0346] (T-1):

[0347] Tetrabutyl titanate (trade name: ORGATICS TA-21, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0348] (T-2):

[0349] Tetrabutyl titanate dimer (trade name: ORGATICS TA-23, manufactured by Matsumoto Fine Chemicals Co., Ltd.)

[0350] (T-3):

[0351] Isopropyl triisostearate titanate (trade name: PLENACT TTS, manufactured by Ajinomoto Fine-Techno Co., Inc.)

[0352] (T-4):

[0353] Dioctyl bis(di-tetranyl)phosphotitanium ester (trade name: PLENACT46B, manufactured by Ajinomoto Fine-Techno Co., Inc.)

[0354] (T-5):

[0355] Diisopropyl bis(dioctyl pyrophosphate) titanate (trade name: PLENACT38S, manufactured by Ajinomoto Fine-TechnOCo., Inc.)

[0356] (U-1):

[0357] Polyether polyurethane elastomer (trade name: PANDEX T-8185, manufactured by DIC)

[0358] (U-2):

[0359] Polyether polyurethane elastomer (trade name: Miractran E380, manufactured by Nippon Polyurethane Co., Ltd.)

[0360] (U-3):

[0361] Polyester polyurethane elastomer (trade name: Miractran E480, manufactured by Nippon Polyurethane Co., Ltd.)

[0362] (U-4):

[0363] Polycarbonate polyurethane elastomer (trade name: SPANDEX T-9280, manufactured by DIC)

[0364] (E-1):

[0365] Polyester elastomer (trade name: PELPRENE P-40B, manufactured by Toyobo Co., Ltd.)

[0366] (Ae-1):

[0367] Polyamide elastomer (trade name: PEBAX4533, manufactured by Arkema)

[0368] (P-1):

[0369] Polyolefin elastomer: ZELAS MC707 (trade name), manufactured by Mitsubishi Chemical Corporation.

[0370] (F-1):

[0371] Fluorinated elastomer: DAI-EL T-530 (trade name), manufactured by Daikin Industries, Ltd.

[0372] The following conclusions can be drawn from the table above.

[0373] Even though the flexible tubes of Comparative Examples 1 and 6-8, which do not have the porous layer specified in this invention, have poorer sealing and heat resistance, they do not have a primer layer.

[0374] Comparative Example 2's flexible tube has an epoxy resin layer between the flexible tube substrate and the primer layer. However, since this epoxy resin layer is not porous, its adhesion and heat resistance are poor. Similarly, Comparative Example 3's flexible tube, which has a non-porous silica layer between the flexible tube substrate and the primer layer, has poor adhesion and heat resistance.

[0375] The flexible tube of Comparative Example 4 has the porous layer specified in this invention, but lacks the primer layer specified in this invention. This flexible tube has poor sealing and heat resistance.

[0376] The flexible tube of Comparative Example 5 has a fluorinated elastomer layer as a polymer coating layer. That is, it does not have the polymer coating layer specified in this invention. The flexible tube has poor resilience, tightness, and heat resistance.

[0377] In contrast, the flexible tubes of the present invention in Examples 1 to 51 have sufficient resilience, excellent sealing properties, and excellent heat resistance.

[0378] Symbol Explanation

[0379] 2. Electronic endoscope (Endoscope)

[0380] 3. Insertion section

[0381] 3a Flexible tube

[0382] 3b Corner

[0383] 3C top part

[0384] 5 Main Operating Unit

[0385] 6. Universal Plug Rope

[0386] 11. Spiral tube

[0387] 11a Metal strip

[0388] 12 cylindrical mesh

[0389] 13 Pipe head

[0390] 14 Flexible tube substrate

[0391] 14a Top side

[0392] 14b Basement side

[0393] 15 Polymer Coating

[0394] 16. Top Coating

[0395] 17 Inner Layer

[0396] 18 Outer layer

[0397] X-shaped bend, side 3b (soft)

[0398] Y Main operating section 5 sides (hard)

[0399] 20 Continuous forming machine (manufacturing equipment)

[0400] Extrusion sections 21 and 22

[0401] 21a Screw

[0402] 22a screw

[0403] 23 Head

[0404] 24 Cooling section

[0405] 25. Conveying Department

[0406] 26 Control Department

[0407] 28 Supply cylinders

[0408] 29. Winding drum

[0409] 30 Connector components

[0410] 31 Connecting Flexible Tube Substrate

[0411] 32 pipe fitting

[0412] 33 mold heads

[0413] 34 Support body

[0414] Gates 35 and 36

[0415] 37 Forming Channel

[0416] 38 Polymer Channels

[0417] 39 First Polymer Material (Soft Polymer)

[0418] 40 Second polymer material (rigid polymer)

Claims

1. A flexible tube for endoscopes, comprising a flexible tube substrate made of metal, a porous layer on the flexible tube substrate containing at least one of epoxy resin and siloxane, having multiple pores in the layer with an average pore size of 50 nm to 100 μm, a primer layer on the porous layer, and a polymer coating layer on the primer layer. The primer layer comprises at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent, including in the form of at least one of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent in the state after reacting with the porous layer or the flexible tube substrate, and in the form of at least one of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent in the state after reacting with the polymer coating layer. The polymer coating layer contains at least one compound selected from polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer.

2. The flexible endoscope tube according to claim 1, wherein, The porous layer contains a polymer compound.

3. The flexible endoscope tube according to claim 1 or 2, wherein, The polymer coating enters the pores of the porous layer while being tightly sealed with the primer layer.

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

5. The flexible endoscope tube according to claim 1 or 2, wherein, The primer layer contains an aminosilane coupling agent.

6. The flexible endoscope tube according to claim 1 or 2, wherein, The metal constituting the flexible tube substrate is stainless steel.

7. The flexible endoscope tube according to claim 1 or 2, wherein, The metal constituting the flexible tube substrate has a passivation film on its surface.

8. The flexible endoscope tube according to claim 1 or 2, wherein, The polymer coating layer is a single-layer or multi-layer structure, and the layer in contact with the primer layer contains at least one compound selected from polyamide, polyester, polyurethane and polyolefin.

9. The flexible endoscope tube according to claim 1 or 2, wherein, The polymer coating has a double-layer structure, and the ratio of the thickness of the inner and outer layers of the double-layer structure varies gradually along the axial direction of the flexible tube substrate.

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

11. An endoscopic medical device comprising an endoscope flexible tube according to any one of claims 1 to 10.

12. A method for manufacturing a flexible tube for an endoscope, comprising: depositing a porous layer on a flexible tube substrate made of metal, the porous layer having at least one of an epoxy resin crosslinker and a siloxane, the porous layer having multiple pores and an average pore size of 50 nm to 100 μm; depositing a primer layer on the porous layer; and depositing a polymer coating layer on the primer layer. The primer layer comprises at least one of a silane coupling agent, a titanium coupling agent, a zirconium coupling agent, and an aluminum coupling agent, including in the form of at least one of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent in the state after reacting with the porous layer or the flexible tube substrate, and in the form of at least one of the silane coupling agent, titanium coupling agent, zirconium coupling agent, and aluminum coupling agent in the state after reacting with the polymer coating layer. The polymer coating layer contains at least one compound selected from polyamide, polyester, polyurethane, and polyolefin on the side in contact with the primer layer.

13. A method for manufacturing an endoscopic medical device, comprising assembling an endoscopic flexible tube obtained by the method for manufacturing an endoscopic flexible tube according to claim 12 into the insertion portion of the endoscopic medical device.

14. A method for manufacturing an endoscopic medical device, comprising assembling an endoscope flexible tube according to any one of claims 1 to 10 into the insertion portion of the endoscopic medical device.

Images