阅读说明：本技术 内窥镜用涂布组合物、内窥镜用润滑性部件、内窥镜用润滑性部件的制造方法、内窥镜用挠性管、及内窥镜 (Coating composition for endoscope, lubricating member for endoscope, method for producing lubricating member for endoscope, flexible tube for endoscope, and endoscope ) 是由 滨田和博 中井义博 奥雅俊 于 2020-05-27 设计创作，主要内容包括：本发明提供一种含有固体润滑剂、含氟表面活性剂、热固性树脂以及溶剂的内窥镜用涂布组合物、通过该涂布组合物实施了涂布处理的、适合作为内窥镜用部件的润滑性部件及其制造方法、以及使用了该润滑性部件的内窥镜用挠性管及内窥镜。(The invention provides a coating composition for an endoscope, which contains a solid lubricant, a fluorosurfactant, a thermosetting resin, and a solvent, a lubricating member which is coated with the coating composition and is suitable as a member for an endoscope, a method for producing the lubricating member, and a flexible tube for an endoscope and an endoscope using the lubricating member.)

1. A coating composition for an endoscope contains a solid lubricant, a fluorosurfactant, a thermosetting resin, and a solvent.

2. The coating composition for an endoscope according to claim 1, wherein,

the fluorosurfactant comprises a nonionic fluorosurfactant.

3. The coating composition for an endoscope according to claim 1 or 2, wherein,

the fluorosurfactant comprises: a fluorine-containing surfactant having an alcoholic hydroxyl group, a polyether structure and at least one structural part derived from a component of a (meth) acrylate monomer.

4. The coating composition for an endoscope according to any one of claims 1 to 3,

the fluorosurfactant comprises a fluorosurfactant having a polyoxyalkylene structure.

5. The coating composition for an endoscope according to any one of claims 1 to 4,

the thermosetting resin comprises a polyamideimide resin.

6. The coating composition for an endoscope according to claim 5, wherein,

the polyamide-imide resin contains a structural unit represented by the following formula (1) as a constituent of polyamide-imide,

[ chemical formula 1]

In the formula, Ar represents a divalent group having an aromatic ring.

7. The coating composition for an endoscope according to claim 6, wherein,

ar of the formula (1) represents a phenylene group, a diphenylmethane structure, a diphenylpropane structure, a diphenyl ether structure, a diphenylsulfone structure, a diphenylamine structure, a biphenyl structure or a naphthalene structure.

8. The coating composition for an endoscope according to claim 7, wherein,

ar of the formula (1) represents a phenylene group, a diphenylmethane structure, a diphenylpropane structure, a diphenyl ether structure or a diphenylamine structure.

9. The coating composition for an endoscope according to any one of claims 5 to 8,

the weight average molecular weight of the polyamide-imide is 10000-100000.

10. The coating composition for an endoscope according to any one of claims 1 to 9,

the solid lubricant includes inorganic particles including at least one of graphite, graphite fluoride, carbon nanotubes, boron nitride, molybdenum disulfide, organic molybdenum, and tungsten disulfide.

11. The coating composition for an endoscope according to claim 10, wherein,

the particle size of the inorganic particles is 0.2 to 4.0 μm.

12. The coating composition for an endoscope according to claim 11, wherein,

the particle size of the inorganic particles is 0.3 to 1.5 μm.

13. The coating composition for an endoscope according to any one of claims 1 to 12,

the solid lubricant contains organic particles, and the organic particles contain at least one of fluororesin and melamine cyanurate.

14. The coating composition for an endoscope according to claim 13, wherein,

the particle size of the organic particles is 0.5 to 30 μm.

15. The coating composition for an endoscope according to claim 14, wherein,

the particle size of the organic particles is 1 to 15 μm.

16. The coating composition for an endoscope according to any one of claims 1 to 15,

the solvent contains at least one of N-methyl-2-pyrrolidone, xylene, N-dimethylacetamide, N-dimethylformamide, hexamethylphosphoric triamide, and 1, 3-dimethyl-2-imidazolidinone.

17. A lubricating member for an endoscope, which is coated with the coating composition for an endoscope according to any one of claims 1 to 16.

18. The lubricating member for an endoscope according to claim 17,

the lubricating member for an endoscope is a lubricating wire for an endoscope.

19. A method for manufacturing a lubricating member for an endoscope, comprising: the coating composition for an endoscope according to any one of claims 1 to 16 is applied to the surface of a member for an endoscope.

20. A flexible tube for an endoscope comprising the lubricating member for an endoscope according to claim 17 or 18.

21. An endoscope comprising the flexible tube for an endoscope according to claim 20.

Technical Field

The present invention relates to an endoscope coating agent, an endoscope lubricating member, a method for producing an endoscope lubricating member, an endoscope flexible tube, and an endoscope.

Background

An endoscope is a medical instrument for observing a body cavity of a patient, and some of the endoscopes include a treatment instrument and are configured to be capable of performing various treatments in a state of being inserted into the body cavity.

The endoscope includes a bendable bending portion on the distal end side of the insertion portion so as to be able to change the observation visual field direction to an arbitrary direction. The bending portion is formed by inserting a wire material made of a stranded wire in which metal wire materials such as stainless steel are bundled, for example, into an endoscope insertion portion, and controlling an operation portion at the hand to stretch the wire material, thereby bending the bending portion in a desired direction. The wire is inserted through a wire guide provided on an inner wall of the endoscope insertion portion and is fixed so as to be slidable along the inner wall of the endoscope insertion portion. The operation of the bending portion itself using a wire is a function provided in a general endoscope, and is disclosed in, for example, patent documents 1 and 2. As a general structure of the wire and the wire guide in the bent portion, for example, fig. 2 of patent document 1 and fig. 6 of patent document 2 can be referred to.

Friction is generated between the wire rod and the wire rod guide by the bending operation of the bending portion, and abrasion of the wire rod is caused. In order to reduce such wear, a coating treatment using a solid lubricant composed of inorganic particles or organic particles is generally performed on the wire rod surface (for example, patent document 3).

The coating treatment with the solid lubricant is generally performed by preparing a coating composition (coating agent) in which the solid lubricant is dispersed in a medium and applying it to the surface of the member to be coated by spraying or the like. In this coating composition, a solvent is used as a medium, and a resin is usually blended as a binder. In addition, in addition to coating by coating, patent document 4 discloses the following method: a solvent for dissolving a member to be coated made of a polymer material is allowed to act on the surface of the member to be coated, and the solid lubricant is integrally bonded to the surface of the member to be coated.

Prior art documents

Patent document

Patent document 1: international publication No. 2018/034021

Patent document 2: japanese laid-open patent publication No. 2009-180

Patent document 3: japanese patent laid-open publication No. 2004-208962

Patent document 4: japanese laid-open patent publication No. 7-155281

Disclosure of Invention

Technical problem to be solved by the invention

When coating with a solid lubricant is performed using a coating composition in which a solid lubricant is dispersed in a medium, the coating composition is required to have dispersion stability of solid lubricant particles. Therefore, a dispersant for improving the dispersibility of the solid lubricant is generally blended in such a coating composition. As such a dispersant, a compound having both a group (for example, an active hydrogen-containing group such as a carboxyl group) having an adsorption property to the solid lubricant and a structural portion having an affinity for the solvent is used.

In addition, in the case where the member to be coated on which the coating layer containing the solid lubricant is formed is a member for an endoscope represented by the wire rod described above, it is required that the coating state (solder resistance) of the coating layer can be sufficiently maintained even if the coating layer is brought into contact with the flux for soldering. For example, the wire material for controlling bending of the bending portion of the endoscope is subjected to a coating treatment with a solid lubricant, and the distal end portion thereof is welded to the distal end portion of the bending portion of the flexible tube. Prior to this welding, a flux is applied to the joint in advance. The flux is a chemical agent generally used in soldering, and has an action of reducing surface tension to facilitate spreading of solder, preventing oxidation of a joint portion, and improving the bondability of solder. As a result of the studies by the present inventors, it has been found that when the flux is brought into contact with a coating layer containing a solid lubricant, the flux penetrates into the coating layer and the like, and the coating layer peels off from the contact portion as a starting point.

The present invention addresses the problem of providing an endoscopic coating composition that has excellent dispersion stability of a solid lubricant, can impart excellent lubricity to an endoscopic member by forming a coating layer by applying the coating composition to the surface of the endoscopic member, can maintain the lubricity for a long period of time even when an endoscope is repeatedly used, and can sufficiently improve the solder resistance of the coating layer. Another object of the present invention is to provide a lubricating member for an endoscope which is coated with the coating composition, and a method for producing the same. Further, another object of the present invention is to provide a flexible tube for an endoscope and an endoscope using the lubricating member for an endoscope.

Means for solving the technical problem

The present inventors have made intensive studies in view of the above problems. As a result, they have found that, in the preparation of a coating composition in which a solid lubricant is dispersed in a solvent, by blending a fluorine-containing surfactant (fluorine-based surfactant) and further combining a thermosetting resin as a binder, the wear resistance of a member to be coated with the composition can be made excellent, excellent lubricity can be maintained for a long period of time even by repeated rubbing, and the peeling of the coating layer is less likely to occur even when the member to be coated is brought into contact with a flux. In addition, in this composition, the fluorosurfactant effectively functions as a dispersant for the solid lubricant, and the dispersion stability of the composition can be sufficiently improved without separately adding a dispersant. The present invention has been completed based on these findings and further research and study.

The above object of the present invention is achieved by the following means.

〔1〕

A coating composition for an endoscope contains a solid lubricant, a fluorosurfactant, a thermosetting resin, and a solvent.

〔2〕

The coating composition for an endoscope according to [ 1], wherein the fluorine-containing surfactant comprises a nonionic fluorine-containing surfactant.

〔3〕

The coating composition for an endoscope according to [ 1] or [ 2], wherein the fluorine-containing surfactant contains a fluorine-containing surfactant having at least one structural part of an alcoholic hydroxyl group, a polyether structure and a component derived from a (meth) acrylate monomer.

〔4〕

The coating composition for an endoscope according to any one of [ 1] to [ 3], wherein the fluorine-containing surfactant contains a fluorine-containing surfactant having a polyoxyalkylene structure.

〔5〕

The coating composition for an endoscope according to any one of [ 1] to [ 4], wherein the thermosetting resin contains a polyamideimide resin.

〔6〕

The coating composition for an endoscope according to [ 5], wherein the polyamideimide resin contains a structural unit represented by the following formula (1) as a constituent component of polyamideimide,

[ chemical formula 1]

In the formula, Ar represents a divalent group having an aromatic ring.

〔7〕

The coating composition for an endoscope according to [ 6 ], wherein Ar in the formula (1) represents a phenylene group, a diphenylmethane structure, a diphenylpropane structure, a diphenyl ether structure, a diphenylsulfone structure, a diphenylamine structure, a biphenyl structure or a naphthalene structure.

〔8〕

The coating composition for an endoscope according to [ 7 ], wherein Ar in the formula (1) represents a phenylene group, a diphenylmethane structure, a diphenylpropane structure, a diphenyl ether structure or a diphenylamine structure.

〔9〕

The coating composition for an endoscope according to any one of [ 5] to [ 8 ], wherein the polyamideimide resin has a weight average molecular weight of 10000 to 100000.

〔10〕

The coating composition for an endoscope according to any one of [ 1] to [ 9], wherein the solid lubricant contains inorganic particles containing at least one of graphite, graphite fluoride, carbon nanotubes, boron nitride, molybdenum disulfide, organic molybdenum, and tungsten disulfide.

〔11〕

The coating composition for an endoscope according to [ 10 ], wherein the inorganic particles have a particle size of 0.2 to 4.0. mu.m.

〔12〕

The coating composition for an endoscope according to [ 11 ], wherein the inorganic particles have a particle size of 0.3 to 1.5 μm.

〔13〕

The coating composition for an endoscope according to any one of [ 1] to [ 12 ], wherein the solid lubricant contains organic particles containing at least one of a fluororesin and melamine cyanurate.

〔14〕

The coating composition for an endoscope according to [ 13 ], wherein the organic particles have a particle size of 0.5 to 30 μm.

〔15〕

The coating composition for an endoscope according to [ 14], wherein the organic particles have a particle size of 1 to 15 μm.

〔16〕

The coating composition for an endoscope according to any one of [ 1] to [ 15 ], wherein the solvent contains at least one of N-methyl-2-pyrrolidone, xylene, N-dimethylacetamide, N-dimethylformamide, hexamethylphosphoric triamide, and 1, 3-dimethyl-2-imidazolidinone.

〔17〕

A lubricating member for an endoscope, which is coated with the coating composition for an endoscope according to any one of [ 1] to [ 16 ].

〔18〕

The lubricative member for an endoscope according to [ 17 ], wherein the lubricative member for an endoscope is a lubricative wire material for an endoscope.

〔19〕

A method for producing a lubricating member for an endoscope, which comprises applying the coating composition for an endoscope according to any one of [ 1] to [ 16 ] to the surface of the member for an endoscope.

〔20〕

A flexible tube for an endoscope comprising the lubricating member for an endoscope according to [ 17 ] or [ 18 ].

〔21〕

An endoscope comprising the flexible tube for endoscope according to [ 20 ].

In the present specification, the structure not designated as substituted or unsubstituted means that the structure may have an arbitrary substituent within a range in which a desired effect is achieved.

In the present specification, the numerical range represented by "to" means that the numerical values recited before and after the range are included as the lower limit value and the upper limit value.

Effects of the invention

The coating composition for endoscopes of the present invention has excellent dispersion stability of the solid lubricant, and can impart excellent lubricity to the member for endoscopes by forming the coating layer by applying the coating composition to the surface of the member for endoscopes, and can sufficiently maintain the lubricity over a long period of time even when the endoscope is repeatedly used, and can sufficiently improve the solder resistance of the coating layer. The lubricating member for endoscopes of the present invention has excellent wear resistance, can exhibit lubricity over a long period of time, and has excellent solder resistance. Further, according to the method for producing a lubricative member for an endoscope of the present invention, it is possible to obtain a lubricative member for an endoscope excellent in wear resistance, capable of exhibiting lubricity for a long period of time, and excellent in flux resistance. The flexible tube for an endoscope and the endoscope of the present invention incorporate the lubricating member for an endoscope of the present invention, and the lubricating member is excellent in wear resistance, can maintain its lubricating property for a long period of time even if the endoscope is repeatedly used, and is also excellent in solder resistance. That is, the flexible tube for an endoscope and the endoscope of the present invention have excellent operation durability.

Drawings

Fig. 1 is an external view showing a configuration of an embodiment of an electronic endoscope.

Fig. 2 is an explanatory view of the wear resistance test in the examples.

Detailed Description

[ coating composition for endoscope ]

The coating composition for an endoscope of the present invention (hereinafter, also referred to as the composition of the present invention) contains a solid lubricant, a fluorosurfactant, a thermosetting resin, and a solvent.

< solid lubricant >

The solid lubricant contained in the composition of the present invention can be widely used as a lubricant generally used as a solid lubricant. Therefore, the solid lubricant used in the present invention may be inorganic particles, organic particles, or a combination thereof. The "solid" in the solid lubricant means a solid state at 25 ℃.

Examples of the material of the solid lubricant composed of inorganic particles include: one or more of graphite, graphite fluoride, carbon nanotubes, boron nitride, molybdenum disulfide, organic molybdenum, and tungsten disulfide can be used. In the present invention, the "organic molybdenum" is a solid lubricant mainly composed of molybdenum, and therefore, for convenience, it is classified as inorganic particles.

When the solid lubricant is an inorganic particle, the particle diameter thereof may be set to, for example, 0.2 to 6.0. mu.m, preferably 0.2 to 4.0. mu.m, more preferably 0.2 to 3.5. mu.m, still more preferably 0.3 to 2.0. mu.m, yet more preferably 0.3 to 1.5. mu.m, and particularly preferably 0.35 to 1.3. mu.m. In the present invention or the specification, the particle diameter refers to an average particle diameter based on a volume.

Examples of the material of the solid lubricant composed of organic particles include: fluorine resins and melamine cyanurate (in the case of the so-called "melamine cyanurate", this is meant to include the tautomeric melamine isocyanurate therewith). Examples of the fluororesin include: polytetrafluoroethylene (PTFE), Polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and the like, and among them, PTFE is preferable.

When the solid lubricant is an organic particle, the particle diameter thereof may be 0.5 to 30 μm, or 1 to 30 μm, preferably 1 to 25 μm, more preferably 1 to 20 μm, further preferably 1 to 15 μm, further preferably 1.5 to 12 μm, further preferably 2 to 10 μm, and particularly preferably 2 to 8 μm.

The composition of the present invention preferably contains at least inorganic particles as a solid lubricant. In addition, when the composition of the present invention contains inorganic particles and organic particles as the solid lubricant, the mass ratio of the contents of the two particles is preferably [ inorganic particles ]/[ organic particles ]. gtoreq.0.3, more preferably [ inorganic particles ]/[ organic particles ]. gtoreq.0.5, and also preferably [ inorganic particles ]/[ organic particles ]. gtoreq.1, also preferably [ inorganic particles ]/[ organic particles ]. gtoreq.1.5, and also preferably [ inorganic particles ]/[ organic particles ]. gtoreq.1.7.

In the composition of the present invention, the content of the solid lubricant is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, still more preferably 15 to 45% by mass, further preferably 25 to 40% by mass, and particularly preferably 26 to 35% by mass.

< fluorinated surfactant >

As the fluorine-containing surfactant (fluorine-containing surfactant), known fluorine-containing surfactants can be widely used. For example, nonionic fluorosurfactants, anionic fluorosurfactants, amphoteric fluorosurfactants, oligomer-type fluorosurfactants, etc. can be used. The fluorosurfactant is preferably a fluorosurfactant having 2 to 16 carbon atoms (fluorine-substituted carbon atoms) to which fluorine atoms are bonded in 1 molecule, and more preferably a fluorosurfactant having 2 to 8 carbon atoms. Furthermore, the fluorine-substituted carbon atom is preferably present as a perfluoroalkyl group or a perfluoroalkenyl group. That is, the fluorosurfactants of the present invention preferably have perfluoroalkyl and/or perfluoroalkenyl groups.

Examples of the nonionic fluorosurfactant include: perfluoroalkyl phosphate ester compounds, perfluoroalkyl ethylene oxide adducts, perfluoroalkyl propylene oxide adducts, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain, and the like.

Examples of the anionic fluorosurfactant include: perfluoroalkyl sulfonic acid compounds, perfluoroalkyl carboxylic acid compounds, perfluoroalkyl phosphate ester compounds, polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain, and the like.

Examples of the amphoteric fluorosurfactant include perfluoroalkyl betaines.

Examples of the perfluoroalkyl sulfonic acid compound include: perfluoroalkyl sulfonic acids, perfluoroalkyl sulfonates, and the like.

Examples of the perfluoroalkyl carboxylic acid compound include: perfluoroalkyl carboxylic acids, perfluoroalkyl carboxylates, and the like.

Examples of the perfluoroalkyl phosphate ester compound include: perfluoroalkyl phosphate esters (nonionic) having a structure in which all-OH hydrogen atoms of phosphoric acid are substituted with perfluoroalkyl groups, perfluoroalkyl phosphate esters having a structure in which some-OH hydrogen atoms of phosphoric acid are substituted with perfluoroalkyl groups, or salts thereof (both anionic), and the like.

Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in a side chain include: polyoxyalkylene ether polymers having a perfluoroalkyl ether group in the side chain (nonionic), salts of polyoxyalkylene ether polymers having a perfluoroalkyl ether group in the side chain (anionic, for example, sulfuric acid ester salts), and the like.

When the anionic fluorosurfactant is in the form of a salt, examples of the counter ion include an alkali metal ion and an ammonium ion, and specific examples thereof include: li, Na, K, NH₄、NH₃CH₂CH₂OH、NH₂(CH₂CH₂OH)₂And NH (CH)₂CH₂OH)₃And the like.

In the composition of the present invention, at least a nonionic fluorosurfactant is preferably used as the fluorosurfactant. The fluorosurfactant contained in the composition of the present invention is also preferably a nonionic fluorosurfactant.

The composition of the present invention preferably contains, as the fluorosurfactant, a fluorosurfactant having an alcoholic hydroxyl group, a polyether structure, and at least one structural part of the components derived from the (meth) acrylate monomer in the molecule. Among them, a fluorosurfactant having a polyether structure is preferably contained as the fluorosurfactant.

Further, the composition of the present invention preferably contains, as the fluorosurfactant, a fluorosurfactant having a polyoxyalkylene structure (a structure having two or more (for example, 2 to 50, preferably 2 to 20) repeating units of alkylene oxide) in the molecule. The number of carbon atoms of the alkylene group constituting the polyoxyalkylene structure is preferably an integer of 1 to 10, more preferably 1 to 6, and further preferably 2 or 3. The polyoxyalkylene structure is more preferably a polyoxyethylene structure. The fluorosurfactant contained in the composition of the present invention is also preferably a fluorosurfactant having a polyoxyalkylene structure in the molecule.

The fluorosurfactant contributes to stabilization of the surface treatment state of the member to be coated, the surface of which has been subjected to the coating treatment using the composition of the present invention. For example, the durability against flux that is often used in soldering can be improved.

In general, when a coating layer containing a solid lubricant is formed on the surface of an operating wire or the like of an endoscope, adhesion between the coating layer in contact with a flux and the surface of the wire is easily impaired when the distal end portion of the wire is welded to the wall surface of a flexible tube of the endoscope. This decrease in adhesion causes peeling of the coating layer, which spreads over time to the periphery of the portion in contact with the flux, and further deteriorates the wear resistance of the wire rod. The reason for this is considered to be an influence of penetration of the flux from the surface of the coating layer into the inside of the coating layer.

However, when the coating layer contains a fluorine-containing surfactant, peeling of the coating layer can be sufficiently suppressed even when the coating layer is brought into contact with the flux. The reason for this is not clear, but it is presumed that the fluorosurfactant exerts an action of repelling the flux on the surface of the coating layer or preventing the flux from penetrating into the coating layer.

The above-mentioned fluorosurfactant exhibits appropriate compatibility with a thermosetting resin described later, and this is also advantageous in improving the abrasion resistance of the coating layer formed.

Furthermore, the fluorosurfactant also effectively functions as a dispersant for the solid lubricant in the composition of the present invention. This is presumably because the fluorosurfactant reduces the cohesive force of the solid particles in the composition. Therefore, the composition of the present invention can exhibit sufficient dispersion stability as a coating composition without separately blending a dispersant of a solid lubricant.

Examples of commercially available fluorosurfactants include: surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145, S-211, S-221, S-231, S-232, S-233, S-241, S-242, S-243, and S-420 (all manufactured by Asahi glass Co., Ltd.);

fluorad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Co.);

megafac F-114, F-444, F-470, F-1405, F-474, F-251, F-253, F-281, F-410, F-430, F-444, F-477, F-510, F-511, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F-558, F-559, F-560, F-561, F-562, F-563, F-565, F-568, F-569, F-570, F-571, F-572 (all manufactured by DIC corporation);

zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR (all manufactured by DuPont Co., Ltd.);

ftergent FT-110, FT-SW100, FT-100C, FT-150, FT-150CH, FT-250, FT-251, FT-212M, FT-215M, FT-250, FT-209F, FT-222F, FT-245F, FT-208G, FT-300, FT-310, FT-320, FT-400S, FT-400SW, FT-150, FT-400, FT-218GL, FT-240G, FT-212P, FT-220P, FT-228P, FTX-218, DFX-18, FT-610FM, FT-710FL, FT-710FM, FT-710FS, FT-730FL, and FT-LM 730 (all manufactured by NEOS corporation);

polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (both manufactured by OMNOVA Inc.), and the like.

Further, as the fluorosurfactant, 2- (perfluorohexyl) ethanol, 2- (perfluorohexyl) hexanol, and the like are also preferable.

In the composition of the present invention, the content of the fluorosurfactant is preferably 0.1 to 20% by mass, more preferably 0.1 to 15% by mass, further preferably 0.2 to 10% by mass, further preferably 0.2 to 8% by mass, further preferably 0.2 to 5% by mass, further preferably 0.2 to 3% by mass, and particularly preferably 0.3 to 2% by mass.

< thermosetting resin >

The composition of the present invention contains a thermosetting resin. The thermosetting resin functions as a binder. By using a thermosetting resin, the wear resistance of the coated member treated with the composition of the present invention can be greatly improved.

The thermosetting resin is not particularly limited. Examples thereof include: polyamideimide resin, polyimide resin (including those present as polyamic acids in the composition), epoxy resin, phenol resin, melamine resin, urea resin, and the like. Among them, the thermosetting resin preferably contains a polyamideimide resin, and more preferably the thermosetting resin is a polyamideimide resin.

The polyamideimide resin preferably contains a structural unit represented by the following formula (1) as a constituent component of the polyamideimide.

[ chemical formula 2]

In the formula, Ar represents a divalent group having an aromatic ring.

Ar is preferably phenylene or diphenylmethane (-phenylene-CH)₂-phenylene-), diphenylpropane junctionsStructure (-phenylene-C)₃H₆-phenylene-), diphenyl ether structure (-phenylene-O-phenylene-), diphenyl sulfone structure (-phenylene-SO)₂-phenylene-), diphenylamine structure (-phenylene-NH-phenylene-), biphenyl structure (-phenylene-), or naphthalene structure, more preferably phenylene, diphenylmethane structure, diphenylpropane structure, diphenyl ether structure, or diphenylamine structure.

The content of the structural unit represented by the formula (1) in the polyamideimide is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and further preferably 90% by mass or more. The polyamideimide is also preferably in a form composed of a structural unit represented by the formula (1).

The weight average molecular weight of the polyamideimide is preferably 10000 to 100000.

In the composition of the present invention, the content of the thermosetting resin is preferably 0.5 to 20% by mass, more preferably 1 to 15% by mass, still more preferably 2 to 10% by mass, and particularly preferably 3 to 8% by mass.

In the composition of the present invention, the content of the fluorine-containing surfactant is preferably 0.1 to 50 parts by mass, more preferably 0.2 to 30 parts by mass, further preferably 0.5 to 20 parts by mass, further preferably 0.5 to 10 parts by mass, further preferably 0.7 to 8 parts by mass, and particularly preferably 0.8 to 6 parts by mass, relative to 100 parts by mass of the content of the solid lubricant.

The content of the thermosetting resin is preferably 1 to 50 parts by mass, more preferably 5 to 40 parts by mass, still more preferably 10 to 30 parts by mass, and particularly preferably 12 to 25 parts by mass, based on 100 parts by mass of the solid lubricant.

In the composition of the present invention, the content of the fluorine-containing surfactant is preferably 2 to 100 parts by mass, more preferably 3 to 90 parts by mass, further preferably 4 to 80 parts by mass, further preferably 5 to 70 parts by mass, further preferably 5 to 60 parts by mass, further preferably 6 to 50 parts by mass, and particularly preferably 7 to 40 parts by mass, relative to 100 parts by mass of the content of the thermosetting resin.

< solvent >

The composition of the present invention contains a solvent as a dispersion medium for the solid lubricant. The solvent is not particularly limited as long as it functions as a dispersion medium. As the solvent, an organic solvent is preferably used.

Examples of the solvent which can be used in the composition of the present invention include: n-methyl-2-pyrrolidone (NMP), xylene, N-dimethylacetamide, N-dimethylformamide, hexamethylphosphoric triamide, 1, 3-dimethyl-2-imidazolidinone, and the like. That is, the solvent used in the composition of the present invention preferably contains one of these solvents or a combination of two or more of them.

In the composition of the present invention, the content of the solvent is not particularly limited as long as it can function as a dispersant for the solid lubricant and can form a composition together with the thermosetting resin. For example, the solvent content in the composition may be 10 to 90% by mass, preferably 20 to 80% by mass, and more preferably 40 to 70% by mass.

The composition of the present invention may contain, in addition to the above components, various additives which are usually used as appropriate within a range not impairing the effects of the present invention. Examples of such additives include: plasticizers, colorants, defoamers, surfactants, dispersants, and the like.

< preparation of coating composition for endoscope >

The composition of the present invention can be obtained by uniformly mixing the above-mentioned components using a homogenizer or the like.

In the present invention, the term "composition" means not only a form in which each component is uniformly present in the composition but also a form in which a part of the component is not uniformly present within a range in which the effect of the present invention is not impaired.

The composition of the present invention can be suitably used as a coating agent for imparting lubricity to various members (members for endoscopes) used in endoscopes. For example, the present invention can be applied to the surface of a wire inserted into an endoscope insertion portion so as to bend a bending portion of the endoscope insertion portion in a desired direction. This can effectively reduce friction between the wire rod and the wire rod guide, and can improve the wear resistance of the wire rod. Further, the present invention can also be applied to the surface of a resin coating layer of a flexible tube for an endoscope.

[ lubricating member for endoscope ]

The lubricating member for an endoscope of the present invention (hereinafter, also referred to as "lubricating member for the present invention") is an endoscope member which is subjected to a coating treatment with the composition of the present invention. The method of coating treatment using the composition of the present invention is not particularly limited. For example, the surface of the member to be coated can be coated with the solid lubricant by applying the composition of the present invention to the surface of the member to be coated and then drying the composition to remove the solvent. The coating can be performed by a spray coating method, a dipping method, a coating method using a brush or a roller, a bar coating method, or the like.

The lubricating member of the present invention is preferably a lubricating wire material for endoscopes. As described above, the lubricating wire can be obtained by applying the composition of the present invention to the surface of a wire inserted through an endoscope insertion portion.

[ Flexible tube for endoscope and endoscope ]

A preferred embodiment of the endoscope of the present invention will be described with reference to an electronic endoscope as an example. An electronic endoscope is used as a medical apparatus in which a flexible tube for an endoscope (hereinafter, the flexible tube for an endoscope is sometimes simply referred to as a "flexible tube") is incorporated and the flexible tube is inserted into a body cavity to observe the inside of the body cavity. In the example shown in fig. 1, the electronic endoscope 2 includes an insertion portion 3 inserted into a body cavity, a main body operation portion 5 connected to a proximal end portion of the insertion portion 3, and a universal cord 6 connected to a processor device or a light source device. The insertion portion 3 includes a flexible tube 3a connected to the main body operation portion 5, a bending portion 3b (a bending portion 3b) connected to the flexible tube 3a, and a distal end portion 3c connected to a distal end of the bending portion 3b and having an imaging device (not shown) for taking an image of the inside of the body cavity built therein. The flexible tube 3a occupying most of the length of the insertion portion 3 is formed to have flexibility over substantially the entire length thereof, and particularly, is formed to have flexibility at a portion inserted into the body cavity or the like. As described above, the bending portion 3b is configured to be bendable in a desired direction by pulling the wire rod inserted into the insertion portion 3 and fixed to the inner wall of the bending portion 3b by the wire rod guide. As an example of a method of bending using a wire, for example, refer to fig. 1 of jp 2009-180 a.

The flexible tube for an endoscope of the present invention includes the lubricating member of the present invention. As the lubricating member provided in the flexible tube for an endoscope of the present invention, as described above, a wire material, a resin coating layer, and the like can be given.

[ examples ]

The present invention will be described in further detail with reference to examples below, but the present invention is not limited to these examples.

[ example 1]

< preparation examples 1-1> preparation of coating composition for endoscope

5.5g of a polyamideimide resin (trade name: ED-7 AUTO EXCEL homogenizer, 45 mm. phi.) composed of a structural unit (Ar is a diphenylmethane structure) of the formula (1), 44.0g of NMP (Fuji film and Wako pure chemical industries, Ltd.) containing NMP used as a solvent in HPC-6000-26 was put into a vessel of a homogenizer (manufactured by Nippon Seiki chemical Co., Ltd., trade name: ED-7 AUTO EXCEL homogenizer, wing diameter: 45 mm. phi.) in terms of solid content, 20.0g of p-xylene (manufactured by Fuji film and Wako pure chemical industries, Ltd., p-xylene contained as a solvent in HPC-6000-26) and 0.5g of a fluorine-containing surfactant (manufactured by DIC Co., Ltd., trade name: Megafac F-444) were mixed by stirring at 1000rpm for 5 minutes.

Then, 20.0g of molybdenum disulfide (product name: C powder, particle size 1.2 μm, manufactured by DAIZO Co., Ltd.) and 10.0g of PTFE particles (product name: KTL-8N, particle size 5.0 μm, manufactured by Xiduocun Co., Ltd.) were added thereto and mixed by stirring at 7000rpm to obtain the coating composition of example 1.

< production examples 1-2> production of lubricating member for endoscope (lubricating wire rod for endoscope)

The coating composition of example 1 (preparation example 1-1) was uniformly sprayed to the entire surface of a stainless steel wire rod (made of SUS304, 0.5 mm. phi., length 500mm) using a hand-held spray gun. Subsequently, the lubricating wire rod for an endoscope of example 1 was produced by heating in an oven at 230 ℃ for 60 minutes to dry the lubricating wire rod and form a coating layer. In this lubricating wire rod for endoscopes, the film thickness of the coating layer was 21 μm. The film thickness was measured at five random positions by a micrometer, and the average value of the five measured values was used.

Examples 2 to 34 and comparative examples 1 to 9

Coating compositions of examples 2 to 34 and comparative examples 1 to 9 were obtained in the same manner as in preparation example 1-1, except that the raw materials used were changed as shown in the following table.

Then, using these coating compositions, the same procedures as in preparation example 1-2 were carried out to obtain lubricating wire rods for endoscopes of examples 2 to 34 and comparative examples 1 to 9.

The amounts of the raw materials shown in the following table are solid contents except for the amount of the solvent.

[ test example 1] Dispersion stability test

The coating compositions of the examples and comparative examples were evaluated for dispersion stability. After the preparation of the coating composition (i.e., after stirring at 7000rpm for 30 minutes after the above-mentioned addition of the solid lubricant), the dispersion state of the composition (dispersion state of the solid lubricant in the solvent) after 1 hour had elapsed was visually observed, and evaluated against the following evaluation criteria.

< evaluation criteria for Dispersion stability >

A: the dispersion state is uniform.

B: the dispersion was slightly inhomogeneous, but no suspension or precipitation was produced.

C: the dispersion state is not uniform, and suspended matter or precipitation is generated.

Test example 2 solder resistance test

The lubricating wire rod for endoscopes of each of the examples and comparative examples was coated with a water-soluble flux (product name: WS-600, manufactured by Cookson Electronics) over the entire surface thereof, and heated at 250 ℃ for 1 minute using a hot plate. After the wire was detached from the hot plate and cooled, the wire was washed with warm water at 60 ℃ to remove the flux, and dried at room temperature for 24 hours.

The dried wire rod was wound in a U-shape around a pulley having a radius of 25mm phi, and reciprocated 5 times, and the coating layer peeled off during this time was recovered and its weight (mg) was measured. The relation between the obtained measurement value and the total coating mass (mg) was compared with the following evaluation criteria to evaluate the solder resistance.

When the wire is wound around the pulley in a U-shape, a length of 78.5mm ([25mm × 2 × 3.14]/2) (a portion corresponding to a semicircle of the outer periphery of the pulley) of the wire is brought into contact with the pulley. In this state, one end of the wire rod is stretched while applying tension to the wire rod, and the pulley is rotated by half a revolution (the rotation direction is defined as the X direction). Then, the other end of the wire rod is pulled while applying tension to the wire rod, and the pulley is rotated once in the opposite direction (the rotation direction is set to the Y direction). This ends the 1 st reciprocation. From this state, the same operation is performed to rotate the pulley once in the X direction and then rotate the pulley once in the Y direction. The rotation in each of the X direction and the Y direction was combined as 1 pass, and the pass was repeated 4 times, and the coating layer peeled off during 5 passes combined with the 1 st pass was collected and the weight thereof was measured.

Further, the mass (mg) of the wire rod before and after coating was measured, and the total coating mass (the weight (mg) of the coating layer covering the periphery of the contact portion "78.5 mm × 3 ═ 235.5 mm" with the pulley in the above 5 passes) was calculated by the following formula.

[ total coating mass (mg) ] - ([ mass of wire after formation of coating layer (mg) ] - [ mass of wire before formation of coating layer (mg) ] -) x 235.5mm/500mm

< evaluation criteria for solder resistance >

A: no peeling of the coating layer was observed, or the mass of the peeled coating layer was less than 10 mass% with respect to the total coating mass (100 mass%)

B: the mass of the coating layer peeled off is 10 mass% or more and less than 20 mass% with respect to the total coating mass

C: the mass of the coating layer peeled off is 20 mass% or more and less than 30 mass% with respect to the total coating mass

D: the mass of the coating layer peeled off is 30 mass% or more with respect to the total coating mass

[ test example 3] abrasion resistance test

The wear resistance test was performed using the test device shown in fig. 2. As shown in fig. 2, the lubricating wire rod (12) for endoscopes obtained in each of the above examples and comparative preparation examples was set on an SUS rod (14) having a diameter of 5mm and pulleys (13, 15) so that the angle (α) was 100 degrees. A load of 10N was applied by a weight (16), and this state was set as the initial state of the test.

Then, the stroke (A) was set to 10mm, and the weight was pulled downward at a speed of 100mm/min and then returned to the original state. The operation is regarded as 1 reciprocation, and the maximum stress (N) measured by the load cell (11) during the 1 reciprocation is recorded as the measured value of the load during the 1 reciprocation.

The stroke and speed were 1000 times repeated to determine an initial load (a value obtained by subtracting the value of the load cell in the initial state of the test from the average value of 50 measurement values of the load cell during 1 to 50 times of the reciprocation) and a final load (a value obtained by subtracting the value of the load cell in the initial state of the test from the average value of 50 measurement values of the load cell during 951 to 1000 times of the reciprocation). The rate of increase in load calculated by the following formula was evaluated against the following evaluation criteria.

Load increase rate (%) < 100 × final load (N)/initial load (N)

< evaluation criteria for abrasion resistance >

A: the increase rate of load is less than 120 percent

B: the load increase rate is more than 120 percent and less than 150 percent

C: the load increase rate is more than 150 percent and less than 200 percent

D: the load increase rate is more than 200%

The results of the above test examples are shown in the following table.

[ Table 1]

[ Table 2]

[ Table 3]

[ Table 4]

[ Table 5]

The respective raw materials described in the above table will be explained.

Inorganic particles-

(A-1)：

Molybdenum disulfide particles (product name "M-5 powder" manufactured by DAIZO Co., Ltd., particle diameter: 0.45 μ M)

(A-2)：

Molybdenum disulfide particles (product name "A powder" manufactured by DAIZO Co., Ltd., particle diameter: 0.63 μm)

(A-3)：

Molybdenum disulfide particles (product name "C powder" manufactured by DAIZO Co., Ltd., particle diameter of 1.2 μm)

(A-4)：

Molybdenum disulfide particles (product name "T powder" of DAIZO Co., Ltd., particle diameter: 3.5 μm)

(A-5)：

Molybdenum disulfide particles (product name "Moly Powder PA" manufactured by Takara Shuzo Co., Ltd., particle diameter of 5.2 μm)

(A-6)：

Graphite particles (product name "RCG 1Q" manufactured by Fuji Black lead industries Co., Ltd., particle size 1.0 μm)

(A-7)：

Multilayered carbon nanotube (product of Nanocyl corporation, trade name "NC 7000", average length (corresponding to particle diameter) 1.5 μm, average diameter 9.5nm)

(A-8)：

Boron nitride particles (SHOBN UHP-S1, made by SHOWA ELECTRIC WORKS Co., Ltd., particle diameter 0.5 μm)

(A-9)：

Tungsten disulfide particles (particle size: 2.0 μm, "Tungmic A" manufactured by Japan Lubricant Co., Ltd.)

(A-10)：

Graphite fluoride particles (Cefbon CMA, manufactured by Mitsu corporation, particle size 2.0 μm)

Organic particles-

(B-1)：

Polytetrafluoroethylene particles (trade name "KTL-500F" made by Xiduocun corporation, particle diameter 0.6 μm)

(B-2)：

Polytetrafluoroethylene particles (trade name "KTL-1N" made by Xiduocun corporation, particle size 2.0 μm)

(B-3)：

Polytetrafluoroethylene particles (trade name "KTL-2N" manufactured by Xiduocun corporation, particle size 3.0 μm)

(B-4)：

Polytetrafluoroethylene particles (trade name "KTL-8N" manufactured by Xiduocun corporation, particle size 5.0 μm)

(B-5)：

Polytetrafluoroethylene particles (trade name "KTL-10S" made by Xiduocun corporation, particle diameter 10 μm)

(B-6)：

Polytetrafluoroethylene particles (trade name "KTL-450" made by Xiduocun corporation, particle size 22 μm)

(B-7)：

Melamine isocyanurate particles (trade name "MC-6000", 2.0 μm particle diameter, manufactured by Nissan chemical industries Co., Ltd.)

Surfactants-

(C-1)：

Fluorinated surfactant (trade name "Megafac F-444" manufactured by DIC Co., Ltd., polyoxyethylene perfluoroalkyl ether)

(C-2)：

Fluorinated surfactant (trade name "Fluorad FC-170C", fluorinated alkyl polyoxyethylene ethanol, manufactured by 3M Co.)

(C-3)：

Fluorinated surfactant (trade name "Ftergent FT-251" manufactured by NEOS Co., Ltd.,. alpha. -perfluorononenoxy-. omega. -methylpolyoxyethylene)

(C-4)：

Fluorinated surfactant (product name "Megafac F-477" manufactured by DIC Co., Ltd., copolymer of monomer having fluoroaliphatic group and polyoxyethylene (meth) acrylate)

(C-5)：

Fluorinated surfactant (2- (perfluorohexyl) ethanol, manufactured by DAIKIN Co., Ltd.)

(C-6)：

Fluorinated surfactant (2- (perfluorohexyl) hexanol, manufactured by DAIKIN Co., Ltd.)

(c-7)：

Non-fluorine-containing dispersant (product name "DISPERBYK-111" manufactured by BYK-Chemie, Inc., having phosphoric acid group as acidic dispersant)

(c-8)：

Fluorine-free dispersant (product name "HOMOGENOL-18" manufactured by HUAWANG CORPORATION, polycarboxylic acid dispersant)

(c-9)：

Non-fluorine-containing surfactant (product name "Adeca Hope MS-30C", Natural alcohol sulfate Na salt, manufactured by ADEKA Co., Ltd.)

(c-10)：

Non-fluorine-containing surfactant (trade name "Pinin A-41-B", Na salt of branched alkyl benzene sulfonate, manufactured by bamboo fat Co., Ltd.)

(c-11)：

Non-fluorine-containing surfactant (product name "Lipon LH-200", linear alkyl benzene sulfonic acid, manufactured by LION Co., Ltd.)

-binders-

(D-1)：

Polyamideimide resin (trade name "HPC-6000-26" manufactured by Hitachi chemical Co., Ltd., weight average molecular weight 40000, structural unit Ar of formula (1) is a diphenylmethane structure)

(D-2)：

Polyimide resin (product name "U-Imide AR" manufactured by UNITIKA Co., Ltd., a product of polyamic acid, which is converted into polyimide resin by thermal reaction)

(D-3)：

Epoxy resin (trade name "2237J", one-pack type, manufactured by Threebond Co., Ltd.)

(d-4)：

Amorphous polyester (product name "VYLON 650" manufactured by TOYOBO Co., Ltd., thermoplastic resin)

(d-5)：

Amorphous ester polyurethane (trade name "UR-1400" manufactured by Toyo textile Co., Ltd., thermoplastic resin)

-solvent-

DMAc: n, N-dimethyl acetamide

DMF: n, N-dimethylformamide

DMI: 1, 3-dimethyl-2-imidazolidinone

HMPA: hexamethylphosphoric triamide

As shown in the above table, when the coating composition does not contain the solid lubricant and the coating layer on the surface of the wire rod formed from the coating composition does not contain the solid lubricant, the wear resistance of the wire rod is poor (comparative example 1).

In addition, when the coating composition contains a thermoplastic resin as a binder and the binder of the coating layer on the surface of the wire rod formed from the coating composition is a thermoplastic resin, the coating composition is inferior in both solder resistance and abrasion resistance (comparative examples 2 and 3).

In addition, when the coating composition does not contain a fluorosurfactant and the coating layer on the surface of the wire rod formed from the coating composition does not contain a fluorosurfactant, the solder resistance is very poor as a result even if a common dispersant or surfactant not containing fluorine is contained (comparative examples 4 to 8). Further, in the case of using linear alkyl benzene sulfonic acid as a surfactant, the dispersion stability was remarkably poor and uniform spraying was not possible (comparative example 9).

On the other hand, the wire rods having the coating layer formed on the surface thereof using the coating composition satisfying the requirements of the present invention are excellent in both solder resistance and wear resistance (examples 1 to 34). Furthermore, the coating compositions of examples 1 to 34 all showed excellent dispersion stability.

The present invention has been described in connection with embodiments thereof, and it is not intended to be limited to the details shown, unless otherwise specified, but rather should be construed broadly within its spirit and scope as set forth in the appended claims.

The present application claims priority of japanese patent application 2019-110023 filed in japan on 6/13/2019, which is hereby incorporated by reference and the contents of which are incorporated as part of the present specification.

Description of the symbols

2 electronic endoscope (endoscope)

3 insertion part

3a flexible pipe

3b bend (corner)

3c tip part

5 main body operation part

6 universal cord

11 dynamometer

12 lubricating wire rod

13. 15 pulley

16 weight

A stroke (10mm)

Alpha angle (100 degree)