Adhesive for endoscope, endoscope, and method for producing same

Abstract

Provided are: an adhesive for an endoscope, the adhesive containing the following components (A)-(C); an endoscope; and a method for producing the endoscope. (A) An epoxy resin, (B) a polyamine compound having two or more unsubstituted amino groups, and (C) a fluorescent organic compound having a maximum fluorescence wavelength of 380-525 nm in an N,N-dimethylformamide solution.

Description

Adhesive for endoscope, endoscope and manufacturing method thereof

[0001] The present invention relates to an adhesive for an endoscope, an endoscope, and a method for manufacturing the same.

[0002] In the manufacture of endoscopes for observing the inside of body cavities, the digestive tract (e.g., the esophagus, stomach, and intestines), and the respiratory tract (e.g., the trachea and bronchi), adhesives are used to assemble and secure fine components and to seal gaps. Among adhesives, epoxy adhesives are also used to bond endoscope components because they offer excellent workability and excellent adhesion, heat resistance, and moisture resistance after curing. Because endoscopes are used repeatedly over long periods of time, the adhesive must be able to adequately maintain the state of fixation of endoscopic components even after repeated use over long periods of time. In other words, the adhesive must be durable enough to maintain the fixation state even when immersed in a disinfectant or subjected to a sterilization process.

[0003] For example, Patent Document 1 describes an adhesive for endoscopes that contains an epoxy resin containing at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, and phenol novolac epoxy resin, an epoxy resin curing component (curing agent) containing at least one of a phosphorus-containing compound, a polythiol compound, a dicyandiamide compound, a phenol compound, a polyamine compound having an unsubstituted amino group, an acid anhydride compound, and an imidazole compound, and a specific radical scavenger. According to Patent Document 1, this adhesive has excellent heat resistance when used to fix endoscopic components (in a cured state), and is also excellent in durability against strong sterilization treatments such as ozone water.

[0004] International Publication No. 2022 / 070809

[0005] In addition to the durability against sterilization described above, endoscope adhesives are also required to adequately penetrate the narrow gaps between the fine components during assembly to securely secure the components. If the adhesive does not adequately penetrate the gaps between the fine components (hereinafter referred to as "insufficient adhesive penetration into the gaps"), the assembly will be defective and the required functions, such as strength, will not be fully realized. Therefore, when assembling an endoscope, it is necessary to check whether the adhesive has penetrated the gaps sufficiently. However, to minimize the impact on images observed through the endoscope, both the components to be fixed with the adhesive and the adhesive itself are often black, making it difficult to determine the state of adhesive filling the gaps by color (appearance).

[0006] The inventors thought that by adding a fluorescent organic compound to the adhesive and irradiating it with excitation light to cause it to emit light and make the adhesive glow, even if the amount of fluorescent organic compound added is small enough that it is thought not to affect endoscopic observation, the black surroundings make it easy to check whether the adhesive has insufficiently penetrated into gaps, and adhesive defects during assembly can be reduced. However, as a result of actual investigations, it was found that even if the amount of fluorescent organic compound added is small, the fluorescence emitted by the light contained in the observation light source during endoscopic white light observation unexpectedly affects the image quality of the observed image.

[0007] An object of the present invention is to provide an endoscopic adhesive that allows easy determination of whether the adhesive has insufficiently penetrated into gaps and that suppresses the influence of adhesive components on images observed under white light observation with an endoscope. Another object of the present invention is to provide an endoscope that uses a cured product of the endoscopic adhesive as a fixing material for components (parts) of the endoscope, thereby suppressing the influence of adhesive components on images observed under white light observation. Another object of the present invention is to provide a method for manufacturing the endoscope using the endoscopic adhesive.

[0008] The above-mentioned problems of the present invention have been solved by the following means. <1> An endoscope adhesive comprising the following components (A) to (C): (A) an epoxy resin; (B) a polyamine compound having two or more unsubstituted amino groups; and (C) a fluorescent organic compound having a maximum fluorescence wavelength of 380 to 525 nm in an N,N-dimethylformamide solution. <2> The endoscope adhesive according to <1>, in which component (B) comprises a polyether polyamine compound. <3> The endoscope adhesive according to <1> or <2>, in which the content of component (C) is 0.005 to 0.500 parts by mass per 100 parts by mass of component (A). <4> The endoscope adhesive according to any one of <1> to <3>, in which component (D) is an inorganic amphoteric ion exchanger from 5 to 30 parts by mass per 100 parts by mass of component (A). <5> An endoscope in which members are fixed with the endoscope adhesive according to any one of <1> to <4>. <6> A method for manufacturing an endoscope, comprising fixing members using the adhesive for an endoscope according to any one of <1> to <4>.

[0009] In the description of the present invention, the symbol "to" is used to mean that the numerical values ​​before and after it are included as the lower and upper limits. In the adhesive for endoscopes of the present invention, each component (components (A) to (C) and optional components) may be used singly or in combination, unless otherwise specified. Substituents (the same applies to linking groups) not specified as substituted or unsubstituted in this specification may have any substituent within the range that achieves the desired effect. Examples of such substituents include those selected from the substituent group T described below. This also applies to compounds not specified as substituted or unsubstituted. In this specification, when the number of carbon atoms in a certain group is specified, this number of carbon atoms refers to the total number of carbon atoms in the group. In other words, if this group has further substituents, this refers to the total number of carbon atoms including the substituents.

[0010] The endoscopic adhesive of the present invention makes it easy to determine whether the adhesive has insufficiently penetrated into gaps and also reduces the influence of the adhesive components on images observed during white light observation with an endoscope. The endoscope of the present invention also uses a cured product of the endoscopic adhesive as a fixing material for components (parts) of the endoscope, thereby reducing the influence of the adhesive components on images observed during white light observation. Furthermore, the manufacturing method of the endoscope of the present invention makes it easy to determine whether the adhesive has insufficiently penetrated into gaps and provides an endoscope in which the influence of the adhesive components on images observed during white light observation is reduced.

[0011] FIG. 1 is an external view showing the configuration of one embodiment of an endoscope of the present invention. FIG. 2 is a partial cross-sectional view showing the configuration of the insertion portion of the endoscope shown in FIG. 1. FIG. 3 is an external perspective view of the tip portion of the insertion portion. FIG. 4 is a partial cross-sectional view of a part cut away of the tip portion. Hatching showing cross sections of lenses and prisms has been omitted. FIG. 5 is an explanatory diagram of evaluation sample S1 used in evaluation 1 of the examples. FIG. 6 is an explanatory diagram of evaluation sample S2 used in evaluation 2 of the examples.

[0012] [Endoscope adhesive] The endoscope adhesive of the present invention (hereinafter also referred to as "the adhesive of the present invention") contains the following components (A) to (C). Component (A): epoxy resin; Component (B): polyamine compound having two or more unsubstituted amino groups; Component (C): fluorescent organic compound having a maximum fluorescence wavelength of 380 to 525 nm in N,N-dimethylformamide solution. Component (A) is the main agent of the adhesive, and component (B) is a curing agent that reacts with the epoxy resin to cure the adhesive. The adhesive of the present invention contains, in addition to the main agent and curing agent, the fluorescent organic compound of component (C).

[0013] The adhesive of the present invention is not limited in its form as long as it contains the above-mentioned components. For example, the endoscopic adhesive of the present invention may be in a form containing a mixture of the above-mentioned components (A) to (C) (one-component type), or it may contain components (A) to (C) in a state where some of the components (A) to (C) are separated from the other components (two-component type). Furthermore, the endoscopic adhesive of the present invention may contain components (A) to (C) in a state where each of the components (A) to (C) is separated from each other (three-component type). Both of these forms are encompassed by the adhesive of the present invention. However, it is preferable that the fluorescent organic compound of component (C) is uniformly dispersed throughout the adhesive and the cured product in the state where components (A) to (C) are mixed (before curing) and in the cured product after curing. When describing the content of each component in an adhesive or specifying the content of each component in an adhesive in the present invention, in the case of a two-component or three-component type, etc., it means that the components (A) to (C) are mixed during use so that the mixture satisfies the desired content described below for each component. In other words, when the components are separated, the content of each of the components (A) to (C) does not need to satisfy the content described in this specification or specified in the present invention. In other words, in the case of a two-component or three-component type, the content described in this specification or specified in the present invention is satisfied at the time when the components (A) to (C) are mixed at the time of use.

[0014] When the adhesive for endoscopes of the present invention is a one-component type, or when it is a two-component type or the like in which components that may react with each other are mixed (for example, when an epoxy resin (component (A)) and its curing agent (component (B)) are mixed), it is preferable to store the adhesive at a low temperature at which the adhesive does not substantially react, in order to prevent or sufficiently suppress reactions between the components and maintain the stability of each component. For example, the adhesive can be stored at 0°C or below, or alternatively, at -10°C or below, -20°C or below, -30°C or below, -40°C or below, or -50°C or below. It can also be stored in a light-shielded state, if necessary.

[0015] In addition to the above components (A) to (C), the adhesive of the present invention can contain, for example, a solvent, a plasticizer, a curing accelerator, an adhesion improver (such as a silane coupling agent), a surfactant, a colorant (such as a pigment or dye, excluding fluorescent organic compounds), a weathering agent, an antioxidant, a heat stabilizer, a lubricant, an antistatic agent, a release agent, a conductive agent, a viscosity adjuster, a filler (such as silica or calcium carbonate), a thixotropic agent, a diluent, and a flame retardant, provided that the effects of the present invention are not impaired.

[0016] The cured product obtained by curing the adhesive of the present invention makes it easy to determine whether the adhesive has insufficiently penetrated into gaps, and also reduces the influence of the adhesive components (fluorescent organic compounds) on the observed image during endoscopic white light observation.

[0017] The adhesive of the present invention is suitable for fixing various components (endoscopic components) that make up an endoscope. That is, the adhesive of the present invention is preferably used to bond (join) an endoscope component to another endoscope component to fix it. The adhesive used to fix the endoscope component becomes a cured product and forms the adhesive joint of the endoscope. In particular, the adhesive of the present invention is suitable for fixing the endoscope component of an endoscope that performs white light observation using white light. There are no particular restrictions on the components that can be fixed using the adhesive of the present invention, and preferred examples include metal components, glass components, and resin components. The "fixing" of an endoscope component is achieved by bonding the endoscope component to another component (supporting member) that makes up the endoscope. The supporting member may be a tube wall or an immovable member fixed to the tube wall, or it may be a member that can move relative to the endoscope, such as a tube. In the present invention, the term "fixing" is used to mean filling, i.e., sealing, the space between the endoscope component and the supporting member into which the component is incorporated with the cured adhesive. The components that make up the adhesive of the present invention are described below.

[0018] <(A) Epoxy Resin> The adhesive of the present invention contains an epoxy resin as component (A). This epoxy resin preferably contains at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, and phenol novolac epoxy resin. The adhesive of the present invention may contain one or more epoxy resins selected from bisphenol A epoxy resin, bisphenol F epoxy resin, and phenol novolac epoxy resin. The proportion of the total amount of bisphenol A epoxy resin, bisphenol F epoxy resin, and phenol novolac epoxy resin in the total amount of epoxy resins contained in the adhesive of the present invention is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The epoxy resin contained in the adhesive of the present invention is particularly preferably at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, and phenol novolac epoxy resin. The epoxy equivalent of the epoxy resin contained in the adhesive of the present invention is preferably 10 to 1,000, more preferably 50 to 500, even more preferably 80 to 400, and particularly preferably 100 to 300. The epoxy resin contained in the adhesive of the present invention usually has two or more epoxy groups per molecule. The epoxy equivalent is the value obtained by dividing the molecular weight of the epoxy compound by the number of moles of epoxy groups contained in the epoxy compound.

[0019] The bisphenol A epoxy resin that can be used in the adhesive of the present invention is not particularly limited, and a wide variety of resins commonly used as the base agent for epoxy adhesives can be used. Preferred examples include bisphenol A diglycidyl ether (jER825, jER828, and jER834 (all trade names, manufactured by Mitsubishi Chemical Corporation)) and bisphenol A propoxylate diglycidyl ether (e.g., manufactured by Sigma-Aldrich).

[0020] The bisphenol F epoxy resin that can be used in the adhesive of the present invention is not particularly limited, and a wide variety of resins commonly used as the base agent for epoxy adhesives can be used. A preferred example is bisphenol F diglycidyl ether (trade name: EPICLON 830, manufactured by DIC Corporation).

[0021] The phenol novolac epoxy resin that can be used in the adhesive of the present invention is not particularly limited, and a wide variety of resins commonly used as the base agent for epoxy adhesives can be used. Such a phenol novolac epoxy resin is commercially available, for example, from Sigma-Aldrich Corporation under product number 406775.

[0022] The content of the epoxy resin in the adhesive of the present invention can be 5 to 99 mass%, more preferably 10 to 98 mass%, even more preferably 20 to 97 mass%, and particularly preferably 30 to 96 mass%.

[0023] <(B) Polyamine Compound Having Two or More Unsubstituted Amino Groups> The adhesive of the present invention contains, as component (B), a polyamine compound having two or more unsubstituted amino groups (—NH ２ ) (hereinafter, "polyamine compound having two or more unsubstituted amino groups" will also be simply referred to as "polyamine compound"). The adhesive of the present invention may contain one type of component (B) alone or a combination of two or more types. The polyamine compound is more preferably a primary polyamine compound (a polyamine compound in which all amino groups are unsubstituted amino groups). The number of unsubstituted amino groups per molecule of the polyamine compound is preferably 2 to 10, more preferably 2 to 8, even more preferably 2 to 6, even more preferably 2 to 4, and particularly preferably 2 or 3. Among these, at least one selected from diamine compounds and triamine compounds is preferably used. The active hydrogen equivalent (equivalent of active hydrogen possessed by the amino group) of the polyamine compound is preferably 25 to 2,000, more preferably 25 to 550, even more preferably 25 to 200, even more preferably 25 to 100, even more preferably 25 to 85, and particularly preferably 27 to 70. The active hydrogen equivalent is the value obtained by dividing the molecular weight of a polyamine compound by the number of moles of active hydrogen in the amino group of the polyamine compound (meaning the molecular weight per active hydrogen in the amino group of the polyamine compound). The amino group having active hydrogen includes an unsubstituted amino group and a primary amino group.

[0024] The molecular weight of the polyamine compound is preferably 100 to 6000, more preferably 100 to 3000, still more preferably 100 to 1000, and particularly preferably 100 to 500. When the polyamine compound is a polymer (for example, when it has a polyoxyalkylene group described below), the molecular weight is a number average molecular weight.

[0025] The polyamine compound preferably has two or more unsubstituted amino groups bonded via a group selected from a chain aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a heterocyclic group, or a group combining these. The group combining these groups may have a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom (an atom other than a carbon atom, preferably an oxygen atom or a nitrogen atom, more preferably an oxygen atom) between the carbon-carbon bond, and preferably has a heteroatom.

[0026] The group linking two or more unsubstituted amino groups is preferably a chain-like aliphatic hydrocarbon group, a combination of a chain-like aliphatic hydrocarbon group and an aromatic hydrocarbon group, a combination of a chain-like aliphatic hydrocarbon group and an alicyclic hydrocarbon group, a group having a heteroatom between the carbon-carbon bonds in a combination of two or more chain-like aliphatic hydrocarbon groups, a group having a heteroatom between the carbon-carbon bonds in a combination of a chain-like aliphatic hydrocarbon group and an aromatic hydrocarbon group, or a group having a heteroatom between the carbon-carbon bonds in a combination of a chain-like aliphatic hydrocarbon group and an alicyclic hydrocarbon group, more preferably a group having a heteroatom between the carbon-carbon bonds in two or more chain-like aliphatic hydrocarbon groups, or a group having a heteroatom between the carbon-carbon bonds in a combination of a chain-like aliphatic hydrocarbon group and an aromatic hydrocarbon group, and even more preferably a group having a heteroatom between the carbon-carbon bonds in two or more chain-like aliphatic hydrocarbon groups. The "chain-like aliphatic hydrocarbon group" may be branched, and when the "group linking two or more unsubstituted amino groups" is a chain-like aliphatic hydrocarbon group, it is preferable that this chain-like aliphatic hydrocarbon group has a branched structure. A preferred example of the "combination of a chain aliphatic hydrocarbon group and an aromatic hydrocarbon group" is "chain aliphatic hydrocarbon group-aromatic hydrocarbon group-chain aliphatic hydrocarbon group." Examples of the "combination of a chain aliphatic hydrocarbon group and an alicyclic hydrocarbon group" include "chain aliphatic hydrocarbon group-alicyclic hydrocarbon group" and "alicyclic hydrocarbon group-chain aliphatic hydrocarbon group-alicyclic hydrocarbon group." Examples of the "group having a heteroatom between the carbon-carbon bond in two or more chain aliphatic hydrocarbon groups" include groups having a polyether structure, which will be described later. Examples of the "group having a heteroatom between the carbon-carbon bond in a combination of a chain aliphatic hydrocarbon group and an aromatic hydrocarbon group" include "[chain aliphatic hydrocarbon group-aromatic hydrocarbon group-chain aliphatic hydrocarbon group-nitrogen atom-chain aliphatic hydrocarbon group-nitrogen atom]-chain aliphatic hydrocarbon group-aromatic hydrocarbon group-chain aliphatic hydrocarbon group." The structure represented by [ ] means a repeating unit, and the number of repeats is, for example, 1 to 20.

[0027] The number of carbon atoms in the chain-like aliphatic hydrocarbon group is preferably 2 to 50, and more preferably 2 to 12. The chain-like aliphatic hydrocarbon group is preferably an alkylene group, and specific examples of the alkylene group include methylene, ethylene, propylene, hexamethylene, 2,4,4-trimethylhexamethylene, and dodecamethylene. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 4 to 50, more preferably 4 to 12, and even more preferably 6 to 12. The cyclic hydrocarbon group is preferably a cycloalkylene group, and specific examples of the cycloalkylene group include cyclobutylene, cyclopentylene, and cyclohexylene. Examples of aromatic hydrocarbon rings constituting the aromatic hydrocarbon group include a benzene ring and a fused ring of two or more benzene rings, and specific examples of such fused rings include a fluorene ring and an acenaphthene ring. Of these aromatic hydrocarbon rings, a benzene ring is preferred.

[0028] The polyamine compound is preferably a polyether polyamine compound, from the viewpoints of making it easier to determine whether the adhesive has insufficiently penetrated into gaps and further suppressing the impact on images observed during endoscopic white light observation. A polyether polyamine compound refers to a compound having a polyether structure and two or more unsubstituted amino groups. The polyether structure is preferably a repeating structure of a group consisting of a group selected from the above-mentioned chain-like aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and heterocyclic group and -O-. A polyoxyalkylene structure is preferred, i.e., a repeating structure of a group consisting of the above-mentioned chain-like aliphatic hydrocarbon group and -O-. The alkylene group constituting the polyoxyalkylene structure may be a linear alkylene group or a branched alkylene group. Furthermore, the alkylene group constituting the polyoxyalkylene structure preferably has 1 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. The polyoxyalkylene structure is more preferably a polyoxyethylene structure or a polyoxypropylene structure. When the polyamine compound of component (B) has a polyoxyalkylene structure, the multiple oxyalkylene groups constituting this polyoxyalkylene structure may be the same or different. Furthermore, the average number of repeating oxyalkylene groups in the polyoxyalkylene structure (when two or more polyoxyalkylene structures are present, this refers to the sum of these repeating groups) is preferably 2 to 1,000, more preferably 2 to 500, even more preferably 2 to 100, even more preferably 2 to 50, particularly preferably 2 to 35, and most preferably 2 to 25. The polyamine compound of component (B) may have multiple polyoxyalkylene structures.

[0029] Specific preferred examples of polyamine compounds that can be used in the present invention are shown below: The number in parentheses is the average number of repeating units in the parentheses.

[0030]

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037] The polyamine compounds can be synthesized by conventional methods, and commercially available products may also be used.

[0038] The content of the polyamine compound of component (B) in the adhesive of the present invention is not particularly limited and can be adjusted appropriately depending on the reaction between component (A) and component (B), etc.

[0039] In the adhesive of the present invention, the content of the polyamine compound as component (B) can be appropriately set taking into consideration the active hydrogen equivalent, etc. For example, it can be 5 to 100 parts by mass, preferably 8 to 75 parts by mass, and more preferably 10 to 50 parts by mass, per 100 parts by mass of the epoxy resin as component (A). Furthermore, the active hydrogen equivalent of the polyamine compound relative to the epoxy equivalent of the epoxy resin as component (A) (active hydrogen equivalent / epoxy equivalent) is preferably 0.05 to 1.5, more preferably 0.10 to 1.2, and even more preferably 0.15 to 1.0.

[0040] <(C) Fluorescent Organic Compound Having a Maximum Fluorescence Wavelength of 380 to 525 nm in N,N-Dimethylformamide Solution> The adhesive of the present invention contains a fluorescent organic compound having a maximum fluorescence wavelength of 380 to 525 nm in N,N-dimethylformamide (DMF) solution. In the present invention, the "maximum fluorescence wavelength in DMF solution" refers to the wavelength exhibiting the maximum fluorescence intensity in a fluorescence spectrum obtained by exciting a DMF solution containing the fluorescent organic compound at a concentration of 1 ppm using a spectrofluorometer such as the RF-6000 (trade name, manufactured by Shimadzu Corporation) at a measurement temperature of 25°C. The maximum fluorescence wavelength exhibited by the fluorescent organic compound of component (C) in DMF solution is preferably 400 to 525 nm, more preferably 420 to 525 nm. The fluorescent organic compound of component (C) does not have two or more unsubstituted amino groups.

[0041] The fluorescent organic compound of component (C) can be any fluorescent organic compound that satisfies the above maximum fluorescence wavelength, and examples thereof include coumarin compounds, thiophene compounds, stilbene compounds, monomethine diaryl compounds (compounds in which aromatic ring groups (which may be aryl groups or heteroaryl groups) are bonded to both ends of a monomethine chain represented by -CH=CH-, excluding stilbene compounds), fluorescein compounds, naphthalene compounds, perylene compounds, and rhodamine compounds. Among these, the fluorescent organic compound of component (C) is preferably a fluorescent organic compound having a benzoxazole structure, and more preferably a bis(benzoxazolyl)thiophene compound, a 1,2-bis(benzoxazolylphenyl)ethene compound (a compound in which the phenyl ring of a stilbene compound has a benzoxazolyl group as a substituent), or a bis(benzoxazolyl)ethylene compound (a monomethine diaryl compound in which the aryl group is a benzoxazolyl group). The benzoxazole structure may have a substituent, and examples of the optional substituent include an alkyl group. The benzoxazole structure of the fluorescent organic compound of component (C) interacts with the benzene rings in the bisphenol A epoxy resin, bisphenol F epoxy resin, and phenol novolac epoxy resin that are preferably contained in the epoxy resin of component (A), thereby increasing the solubility of component (C) in component (A), and enabling component (C) to be more uniformly present in the adhesive of the present invention and its cured product.

[0042] The molecular weight of the fluorescent organic compound of component (C) can be, for example, 150 to 1,000. From the viewpoints of making it easier to determine whether the adhesive has insufficiently penetrated into gaps and further suppressing the influence of the adhesive components on images observed in white light observation using an endoscope, the molecular weight is preferably 170 to 800, more preferably 190 to 600, and even more preferably 220 to 500.

[0043] In the adhesive of the present invention, the content of the fluorescent organic compound as component (C) can be appropriately set within a range that allows easy determination of whether the adhesive has insufficiently penetrated into gaps and that suppresses the influence of the adhesive components on images observed under white light endoscopy. For example, the content can be 0.005 to 0.500 parts by mass, preferably 0.007 to 0.300 parts by mass, and more preferably 0.010 to 0.200 parts by mass, per 100 parts by mass of the epoxy resin as component (A).

[0044] <(D) Inorganic Amphoteric Ion Exchanger> The adhesive of the present invention preferably contains an inorganic amphoteric ion exchanger. The term "inorganic amphoteric ion exchanger" refers to a metal-containing inorganic compound that exhibits ion exchange for both cations and anions. That is, the inorganic amphoteric ion exchanger used in the present invention is a metal-containing inorganic compound that, when contacted with an aqueous solution of a salt, releases its own cations and anions into the solution and, in return, can incorporate the cations and anions in the solution into the inorganic amphoteric ion exchanger.

[0045] The inorganic ion exchanger that can be used in the adhesive of the present invention is not particularly limited, and is preferably an inorganic compound containing at least one of bismuth (Bi), antimony (Sb), zirconium (Zr), magnesium (Mg), and aluminum (Al), and more preferably an inorganic compound containing two or three of the above atoms. Examples of combinations of two of the above atoms include a combination of Sb and Bi, and a combination of Zr and Bi. Specific examples of inorganic ion exchangers containing a combination of Sb and Bi atoms include IXE-600 and IXE-633 (all of which are product names manufactured by Toagosei Co., Ltd.). Specific examples of inorganic ion exchangers containing a combination of Zr and Bi atoms include IXE-6107, IXE-6136, and IXEPLAS-B1 (all of which are product names manufactured by Toagosei Co., Ltd.). Examples of combinations of three of the above atoms include a combination of Zr, Mg, and Al. Specific examples of inorganic ion exchangers having a combination of Zr atoms, Mg atoms, and Al atoms include IXEPLAS-A1 and IXEPLAS-A2 (both of which are trade names manufactured by Toagosei Co., Ltd.; "IXE" and "IXEPLAS" are registered trademarks).

[0046] In the adhesive of the present invention, the shape of the inorganic ion exchanger is not particularly limited and may be, for example, particulate or amorphous, with particulate being preferred. The median diameter (D50) of the inorganic ion exchanger is, for example, preferably 0.1 to 10 μm, more preferably 0.1 to 5 μm, and even more preferably 0.1 to 3 μm. The median diameter (D50) can be determined using a particle size distribution analyzer (e.g., HORIBA LA-950V2 (trade name)) based on the "Particle Size Analysis - Laser Diffraction Method" specified in JIS Z 8825-1:2013.

[0047] The content of the inorganic ion exchanger in the adhesive of the present invention is not particularly limited, and is, for example, preferably 5 to 30 parts by mass, more preferably 7 to 30 parts by mass, more preferably 10 to 30 parts by mass, still more preferably 15 to 30 parts by mass, and particularly preferably 20 to 30 parts by mass, relative to 100 parts by mass of the epoxy resin as component (A).

[0048] <(E) Inorganic Filler> The adhesive of the present invention may contain an inorganic filler as component (E). The inorganic filler of component (E) functions, for example, as a viscosity modifier, a filler, a colorant, etc. Examples of the inorganic filler include so-called inorganic fillers such as alumina (aluminum oxide), magnesia (magnesium oxide), titanium oxide (titanium white), aluminum hydroxide, barium titanate, zinc oxide, silica (including crystalline silica (silicon oxide) and fused silica (silicon oxide)), metal nanoparticles, and glass fibers; layered silicates such as talc, clay, mica, smectite, kaolin minerals, mica clay, and vermiculite; metal powders such as silver powder and copper powder; and nitrides such as aluminum nitride, boron nitride, silicon nitride, and gallium nitride, which function as viscosity modifiers, fillers, etc. Furthermore, silicon carbide, carbon black, graphite, carbon fibers, carbon nanotubes, etc. can also be used as the inorganic filler, which function as a black colorant. It is also preferable that the inorganic filler be surface-treated. There are no particular limitations on such surface treatment. For example, surface treatment with a silane compound can be used. In the present invention, the silane compound refers to a compound having a structure in which at least one organic group is bonded to Si. More preferably, SiR ４ (R ４ is an organic group). As the silane compound, a silane coupling agent, a silazane, and a silicone compound (polysiloxane) are preferred. Such a surface treatment method can be carried out by a conventional method. For example, reference can be made to paragraphs

[0090] to

[0101] of JP 2018-195964 A.

[0049] The inorganic filler can be commercially available. For example, commercially available alumina products include DAM-70, DAM-45, DAM-07, DAM-05, DAW-45, DAW-05, DAW-03, and ASFP-20 (all trade names, manufactured by Denki Kagaku Kogyo Co., Ltd.), AL-43-KT, AL-47-H, AL-47-1, AL-160SG-3, AL-43-BE, AS-30, AS-40, AS-50, AS-400, CB-P02, and CB-P05 (all trade names). , manufactured by Showa Denko K.K.), A31, A31B, A32, A33F, A41A, A43A, MM-22, MM-26, MM-P, MM-23B, LS-110F, LS-130, LS-210, LS-242C, LS-250, and AHP300 (all trade names, manufactured by Nippon Light Metal Co., Ltd.), AA-03, AA-04, AA-05, AA-07, AA-2, AA-5, AA-10, and AA-18 (all trade names, manufactured by Sumitomo Chemical Co., Ltd.), AEROXIDE Alu C, AEROXIDE Alu C805, and AEROXIDE Alu 65 (all trade names, manufactured by Nippon Aerosil Co., Ltd.). Commercially available titanium oxide products include, for example, G-1, G-10, F-2, F-4, and F-6 (all trade names, manufactured by Showa Denko K.K.), TAF-520, TAF-500, TAF-1500, TM-1, TA-100C, and TA-100CT (all trade names, manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-01, MT-10EX, MT-05, MT-100S, MT-100TV, MT-100Z, MT-150EX, MT-100AQ, MT-100WP, MT-100SA, and MT-100HD. , MT-300HD, MT-500SA, MT-600SA, and MT-700HD (all trade names, manufactured by Teika Corporation), TTO-51(A), TTO-51(C), TTO-55(A), TTO-55(B), TTO-55(C), TTO-55(D), TTO-S-1, TTO-S-2, TTO-S-3, TTO-S-4, MPT-136, and TTO-V-3 (all trade names, manufactured by Ishihara Sangyo Kaisha), and Aeroxide NKT90 (trade name, manufactured by Nippon Aerosil Co., Ltd.).Commercially available aluminum hydroxide products include, for example, B-309 and B-309 (all trade names, manufactured by Tomoe Engineering Co., Ltd.), BA173, BA103, B703, B1403, BF013, BE033, BX103, and BX043 (all trade names, manufactured by Nippon Light Metal Co., Ltd.). Commercially available products of the layered silicates include, for example, Nanoace D-1000, Nanoace D-800, Microace SG-95, Microace P-8, and Microace P-6 (all trade names of talc, manufactured by Nippon Talc Co., Ltd.), FH104, FH105, FL108, FG106, MG115, FH104S, and ML112S (all trade names of talc, manufactured by Fuji Talc Co., Ltd.), Y-1800, TM-10, A-11, and SJ-005 (all trade names of mica, manufactured by Yamaguchi Mica Co., Ltd.), and Kunibis-110 (trade name, manufactured by Kunimine Industries Co., Ltd.). Commercially available products of the barium titanate include, for example, BT-H9DX, HF-9, HF-37N, HF-90D, HF-120D, and HT-F (all trade names, manufactured by Kyoritsu Material Co., Ltd.), BT-100 and HPBT series (all trade names, manufactured by Fuji Titanium Co., Ltd.), BT series (trade name, manufactured by Sakai Chemical Industry Co., Ltd.), and Parceram BT (trade name, manufactured by Nippon Chemical Industry Co., Ltd.). Commercially available zinc oxide products include, for example, FINEX-30, FINEX-30W-LP2, FINEX-50, FINEX-50S-LP2, and XZ-100F (all trade names, manufactured by Sakai Chemical Industry Co., Ltd.), FZO-50 (trade name, manufactured by Ishihara Sangyo Kaisha), MZ-300, MZ-306X, MZY-505S, MZ-506X, and MZ-510HPSX (all trade names, manufactured by Teika Corporation).

[0050] Commercially available examples of the glass fibers include CS6SK-406, CS13C-897, CS3PC-455, and CS3LCP-256 (all trade names, manufactured by Nitto Boseki Co., Ltd.), ECS03-615, ECS03-650, EFDE50-01, and EFDE50-31 (all trade names, manufactured by Central Glass Co., Ltd.), ACS6H-103 and ACS6S-750 (all trade names, manufactured by Nippon Electric Glass Co., Ltd.), and CF0027, CF0093, CF0018, and CF0033 (all trade names, manufactured by Nippon Frit Co., Ltd.). Commercially available products of the metal powder include, for example, spherical silver powders AG3 and AG4, flake silver powders FA5 and FA2 (all trade names, manufactured by Dowa Hightec Co., Ltd.), SPQ03R, SPN05N, SPN08S, and Q03R (all trade names of silver powders, manufactured by Mitsui Mining & Smelting Co., Ltd.), AY-6010 and AY-6080 (all trade names of silver powders, manufactured by Tanaka Kikinzoku Co., Ltd.), ASP-100 (trade name of silver powder, manufactured by Aida Chemical Industry Co., Ltd.), Ag-coated powder AG / SP (silver powder), , trade name, manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), MA-O015K, MA-O02K, MA-O025K (all of which are trade names of copper powder, manufactured by Mitsui Mining & Smelting Co., Ltd.), electrolytic copper powder #52-C, #6 (manufactured by JX Nippon Mining & Metals Corporation), 10% Ag coated Cu-HWQ (trade name of copper powder, manufactured by Fukuda Metal Foil & Powder Co., Ltd.), Type-A and Type-B (all of which are trade names of copper powder, manufactured by Dowa Electronics Co., Ltd.), and UCP-030 (trade name of copper powder, manufactured by Sumitomo Metal Mining Co., Ltd.).Commercially available products of the nitrides include, for example, H grade, E grade, and H-T grade (all of which are trade names of aluminum nitride, manufactured by Tokuyama Corporation), TOYAL TecFiller TFS-A05P and TOYAL TecFiller TFZ-A02P (all of which are trade names of aluminum nitride, manufactured by Toyo Aluminum K.K.), ALN020BF, ALN050BF, ALN020AF, ALN050AF, and ALN020SF (all of which are trade names of aluminum nitride, manufactured by Tomoe Engineering Co., Ltd.), FAN-f05 and FAN-f30 (all of which are trade names of aluminum nitride, manufactured by Furukawa Denshi Co., Ltd.), Denka Boron Nitride SGP, Denka Boron Nitride MGP, Denka Boron Nitride Examples of commercially available silicon carbide include Ido GP, Denka Boron Nitride HGP, Denka Boron Nitride SP-2, and Denka Boron Nitride SGPS (all trade names of boron nitride, manufactured by Denki Kagaku Kogyo Co., Ltd.), UHP-S1, UHP-1K, UHP-2, and UHP-EX (all trade names of boron nitride, manufactured by Showa Denko K.K.), and SN-9, SN-9S, SN-9FWS, SN-F1, and SN-F2 (all trade names of silicon nitride, manufactured by Denki Kagaku Kogyo Co., Ltd.). Examples of commercially available silicon carbide products include GMF-H type, GMF-H2 type, and GMF-LC type (all trade names, manufactured by Taiheiyo Random Corporation), HSC1200, HSC1000, HSC059, HSC059I, and HSC007 (all trade names, manufactured by Tomoe Engineering Co., Ltd.). Commercially available products of the silica include, for example, Silysia (manufactured by Fuji Silysia Chemical Ltd.), AEROSIL R972, AEROSIL R104, AEROSIL R202, AEROSIL 805, AEROSIL R812, AEROSIL RX200, AEROSIL R9200, AEROSIL NAX50, AEROSIL 200, and AEROSIL Examples of suitable crystalline silica include R7200 (trade names, manufactured by Nippon Aerosil Co., Ltd.), Leosil series (manufactured by Tokuyama Corporation), CMC-12, VX-S, and VX-SR (trade names of crystalline silica, manufactured by Tatsumori Co., Ltd.), FB-3SDC, FB-3SDX, SFP-30M, SFP-20M, SFP-30MHE, SFP-130MC, and UFP-30 (trade names of fused silica, manufactured by Denki Kagaku Kogyo Co., Ltd.), and Excelica series (trade names of fused silica, manufactured by Tokuyama Corporation).Commercially available products of the carbon fibers, carbon black, graphite, and carbon nanotubes include, for example, Toray Industries, Inc.'s Toray Industries, Inc.'s Toray Industries, Inc.'s Toray Industries, Inc.'s CFMP-30X and CFMP-150X (both carbon fiber products, Nippon Polymer Co., Ltd.'s CFMP-30X and CFMP-150X), Mitsubishi Chemical Corporation's #1000 (carbon black product), Mitsubishi Chemical Corporation's XN-100 and HC-600 (graphite product), Nippon Graphite Fiber Co., Ltd.'s Denka Black (carbon black product), Denka Company, Ltd.'s SWeNT SG65, SWeNT SGi, IsoNanoTubes-M, IsoNanoTubes-S, PureTubes, and Pyrograf. Examples include PR-25-XT-PS and PR-25XT-LHT (both are trade names of carbon nanotubes, manufactured by Sigma-Aldrich).

[0051] The inorganic filler preferably contains at least one of silica (preferably fumed silica), titanium oxide, alumina, and layered silicate, which function as a viscosity modifier, and more preferably contains silica. Furthermore, from the viewpoint of improving chemical resistance, these are preferably surface-treated to be hydrophobic. More preferred are inorganic fillers in which at least an alkyl group has been introduced onto the surface of the inorganic filler by surface treatment, i.e., alkyl-modified inorganic fillers. Of these, surface-treated silica (preferably alkyl-modified silica particles) is preferred. Furthermore, the inorganic filler preferably contains at least one of silicon carbide, carbon black, graphite, carbon fiber, and carbon nanotubes, which function as a black colorant, and more preferably contains carbon black.

[0052] The inorganic filler used in the present invention preferably has a volume-based median diameter (D50) of 1 to 10,000 nm, more preferably 3 to 5,000 nm, even more preferably 5 to 2,000 nm, even more preferably 5 to 1,000 nm, still more preferably 6 to 500 nm, still more preferably 7 to 200 nm, and particularly preferably 8 to 100 nm. In the case of silica, titanium oxide, and alumina, from the viewpoint of the chemical resistance of the cured product, the volume-based median diameter (D50) is preferably 1 to 500 nm, more preferably 5 to 200 nm, even more preferably 6 to 100 nm, and particularly preferably 7 to 50 nm.

[0053] The volume-based median diameter (D50) of the inorganic filler is measured by the following method. The inorganic filler is added to methanol to a concentration of 0.5% by mass, and the inorganic filler is dispersed by applying ultrasonic waves for 10 minutes. The particle size distribution of the inorganic filler thus treated is measured using a laser diffraction / scattering particle size distribution analyzer (manufactured by Horiba, Ltd., product name: LA950V2), and the volume-based median diameter (D50) is determined. The median diameter corresponds to 50% of the cumulative distribution when the particle size distribution is expressed as a cumulative distribution.

[0054] In the adhesive of the present invention, the content of the inorganic filler of component (E) is preferably 4 to 20 mass%, more preferably 4 to 15 mass%, and even more preferably 4 to 12 mass%, from the viewpoint of the viscosity of the adhesive. Also, in the adhesive of the present invention, the content of the black colorant is preferably 1 to 15 mass%, more preferably 1.5 to 10 mass%, and even more preferably 2 to 8 mass%.

[0055] In the adhesive of the present invention, the content of the inorganic filler as component (E) can be 1 to 50 parts by mass, and preferably 4 to 20 parts by mass, per 100 parts by mass of the epoxy resin as component (A). Also, in the adhesive of the present invention, the content of the black colorant can be 0.25 to 37.5 parts by mass, and preferably 1 to 13.3 parts by mass, per 100 parts by mass of the epoxy resin as component (A).

[0056] The inorganic filler of component (E) is preferably in a state where it is uniformly dispersed in the adhesive when components (A) to (C) are mixed (before curing).

[0057] - Substituent Group T - In the present invention, preferred substituents include those selected from the following Substituent Group T. In the present invention, when a substituent is simply described, the description of the corresponding substituent in Substituent Group T can be referenced and applied. For example, when an "alkyl group" is simply described, the description of the "alkyl group" in Substituent Group T can be referenced and applied. This also applies to substituents other than "alkyl groups." In the present invention, the substituent that a certain substituent such as an "alkyl group" may have includes a substituent selected from the following Substituent Group T. In addition, when a certain substituent such as an "alkyl group" has a substituent and further has a substituent, the substituent that the certain substituent such as an "alkyl group" has includes a substituent formed by combining two or more substituents selected from the following Substituent Group T. Furthermore, in this specification, when an alkyl group is described separately from a cyclic (cyclo)alkyl group, the alkyl group is used to encompass both linear and branched alkyl groups. On the other hand, when an alkyl group is not described separately from a cyclic alkyl group, or unless otherwise specified, the alkyl group is used to encompass both linear and branched alkyl groups, and cycloalkyl groups. This also applies to groups (alkoxy groups, alkylthio groups, alkenyloxy groups, etc.) containing groups capable of forming a cyclic structure (alkyl groups, alkenyl groups, alkynyl groups, etc.) and compounds containing groups capable of forming a cyclic structure. When a group can form a cyclic skeleton, the lower limit of the number of atoms in the group forming the cyclic skeleton is 3 or more, preferably 5 or more, regardless of the lower limit of the number of atoms specifically described below for groups capable of forming this structure. In the description of the substituent group T below, for example, groups having a linear or branched structure and groups having a cyclic structure are sometimes described separately, such as alkyl groups and cycloalkyl groups, in order to clarify these.

[0058] Groups included in the substituent group T include the following groups: an alkyl group (preferably having 1 to 30 carbon atoms, more preferably having 1 to 20 carbon atoms, even more preferably having 1 to 12 carbon atoms, even more preferably having 1 to 8 carbon atoms, even more preferably having 1 to 6 carbon atoms, and particularly preferably having 1 to 3 carbon atoms), an alkenyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 20 carbon atoms, even more preferably having 2 to 12 carbon atoms, even more preferably having 2 to 6 carbon atoms, and even more preferably having 2 to 4 carbon atoms), an alkynyl group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 20 carbon atoms, and even more preferably having a cycloalkyl group (preferably having 3 to 20 carbon atoms), a cycloalkenyl group (preferably having 5 to 20 carbon atoms), an aryl group (which may be a monocyclic group or a condensed ring group (preferably a condensed ring group of 2 to 6 rings). When it is a condensed ring group, it consists of a 5- to 7-membered ring, etc. The aryl group preferably has 6 to 40 carbon atoms, more preferably has 6 to 30 carbon atoms, even more preferably has 6 to 26 carbon atoms, particularly preferably has 6 to 10 carbon atoms), Heterocyclic groups (having at least one nitrogen atom, oxygen atom, sulfur atom, phosphorus atom, silicon atom or selenium atom as a ring-constituting atom) may be monocyclic groups or condensed ring groups (preferably condensed ring groups of 2 to 6 rings). In the case of monocyclic groups, the number of ring members is preferably 5 to 7, more preferably 5 or 6. The number of carbon atoms in the heterocyclic group is preferably 2 to 40, more preferably 2 to 20. Heterocyclic groups include aromatic heterocyclic groups (heteroaryl groups) and aliphatic heterocyclic groups (aliphatic heterocyclic groups). ), an alkoxy group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 12 carbon atoms), an alkenyloxy group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms), an alkynyloxy group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms), a cycloalkyloxy group (preferably having 3 to 20 carbon atoms), an aryloxy group (preferably having 6 to 40 carbon atoms, more preferably having 6 to 26 carbon atoms, even more preferably having 6 to 14 carbon atoms), a heterocyclic oxy group (preferably having 2 to 20 carbon atoms),

[0059] Alkoxycarbonyl groups (preferably having 2 to 20 carbon atoms), cycloalkoxycarbonyl groups (preferably having 4 to 20 carbon atoms), aryloxycarbonyl groups (preferably having 6 to 20 carbon atoms), amino groups (preferably having 0 to 20 carbon atoms and unsubstituted amino groups (—NH ２ ), (mono- or di-) alkylamino group, (mono- or di-) alkenylamino group, (mono- or di-) alkynylamino group, (mono- or di-) cycloalkylamino group, (mono- or di-) cycloalkenylamino group, (mono- or di-) arylamino group, (mono- or di-) heterocyclic amino group. Each of the above groups substituting the unsubstituted amino group has the same meaning as the corresponding group in Substituent Group T. ), sulfamoyl group (preferably having 0 to 20 carbon atoms, and an alkyl, cycloalkyl, or aryl sulfamoyl group is preferred.), acyl group (preferably having 1 to 20 carbon atoms, more preferably having 2 to 15 carbon atoms), acyloxy group (preferably having 1 to 20 carbon atoms), carbamoyl group (preferably having 1 to 20 carbon atoms, and an alkyl, cycloalkyl, or aryl carbamoyl group is preferred.),

[0060] an acylamino group (preferably having 1 to 20 carbon atoms), a sulfonamido group (preferably having 0 to 20 carbon atoms, and an alkyl, cycloalkyl, or aryl sulfonamido group is preferred), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 12 carbon atoms), a cycloalkylthio group (preferably having 3 to 20 carbon atoms), an arylthio group (preferably having 6 to 40 carbon atoms, more preferably having 6 to 26 carbon atoms, and even more preferably having 6 to 14 carbon atoms), a heterocyclic thio group (preferably having 2 to 20 carbon atoms), an alkyl, cycloalkyl, or arylsulfonyl group (preferably having 1 to 20 carbon atoms),

[0061] Silyl group (preferably a silyl group having 1 to 30 carbon atoms, more preferably a silyl group having 1 to 20 carbon atoms and substituted with alkyl, aryl, alkoxy or aryloxy), silyloxy group (preferably a silyloxy group having 1 to 20 carbon atoms and substituted with alkyl, aryl, alkoxy or aryloxy), hydroxy group, cyano group, nitro group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom or iodine atom), oxygen atom (specifically, a >CH ２ is replaced with >C=O), a carboxy group (-CO ２ H), phosphono group [—PO(OH) ２ ], a phosphoryl group [—O—PO(OH) ２ ], sulfo group (—SO ３ H), boric acid group [—B(OH) ２ ], an onio group (including an ammonio group including a cyclic ammonio group, a sulfonio group, and a phosphonio group, preferably having 0 to 30 carbon atoms, more preferably 1 to 20 carbon atoms), a sulfanyl group (—SH), an amino acid residue, or a polyamino acid residue. Further examples include the above-mentioned alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, aryl group, heterocyclic group, alkoxy group, alkenyloxy group, alkynyloxy group, cycloalkyloxy group, aryloxy group, heterocyclicoxy group, alkoxycarbonyl group, cycloalkoxycarbonyl group, aryloxycarbonyl group, amino group, sulfamoyl group, acyl group, acyloxy group, carbamoyl group, acylamino group, sulfonamido group, alkylthio group, cycloalkylthio group, arylthio group, heterocyclicthio group, alkyl, cycloalkyl, or arylsulfonyl group, each of which has a carboxy group, phosphono group, sulfo group, onio group, amino acid residue, or polyamino acid residue as a substituent.

[0062] The substituent selected from the substituent group T is more preferably an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an alkoxycarbonyl group, a cycloalkoxycarbonyl group, an amino group, an acylamino group, a cyano group, or a halogen atom, and particularly preferably an alkyl group, an alkenyl group, an aryl group, a heterocyclic group, an alkoxy group, an alkoxycarbonyl group, an amino group, an acylamino group, or a cyano group.

[0063] Unless otherwise specified, the substituents selected from the substituent group T also include groups formed by combining a plurality of the above groups. For example, when the compound or the substituent contains an alkyl group, an alkenyl group, or the like, it may be substituted or unsubstituted. Furthermore, when it contains an aryl group, a heterocyclic group, or the like, it may be a monocyclic or fused ring, and it may be substituted or unsubstituted.

[0064] [Cured Product] The cured product of the present invention is a product obtained by curing the adhesive of the present invention. That is, the cured product of the present invention is used as a component constituting the adhesive portion of an endoscope. The curing temperature of the adhesive of the present invention is not particularly limited. The adhesive of the present invention undergoes an efficient curing reaction even at low temperatures, allowing the cured product of the present invention to be obtained. The components are preferably mixed while removing air bubbles, and therefore, the mixture is usually carried out under reduced pressure. The curing temperature is preferably 100°C or less, more preferably 80°C or less, even more preferably 60°C or less, and can also be 50°C or less. Furthermore, to ensure sufficient curing reaction, the curing temperature is preferably 0°C or higher, more preferably 10°C or higher. The preferred range is 0 to 100°C, more preferably 0 to 80°C, even more preferably 10 to 60°C, and particularly preferably 10 to 50°C. The curing reaction time can be appropriately set depending on the purpose. The curing reaction is usually carried out for 1.5 to 200 hours to obtain a cured product.

[0065] [Endoscope] The endoscope of the present invention has its components fixed by the cured product of the present invention. "The components are fixed by the cured product of the present invention" means that at least some of the components constituting the endoscope are fixed to a support member via the cured product of the present invention.

[0066] An example of an endoscope (electronic endoscope) according to the present invention will be described. An electronic endoscope incorporates a flexible endoscopic tube (hereinafter, the flexible endoscopic tube may be simply referred to as a "flexible tube") and is widely used as a medical device. In the example shown in FIG. 1 , an electronic endoscope 2 includes an insertion section 3 for insertion into a body cavity, a main body control section 5 connected to the proximal end of the insertion section 3, and a universal cord 6 connected to a processor and a light source. The insertion section 3 comprises a flexible tube 3a connected to the main body control section 5, an angle section 3b connected thereto, and a tip section 3c connected to the tip of the flexible tube 3a and constructed primarily of a metal (e.g., stainless steel) member. An imaging device (not shown) for capturing images inside the body cavity is built into the tip section 3c. The flexible tube 3a, which accounts for the majority of the length of the insertion section 3, is flexible throughout its entire length, with the portion inserted into the body cavity being particularly flexible. In FIG. 1, a plurality of channels (tubes, not shown) are formed in the axial direction of the insertion section 3 from the main body operating section 5 to the distal end surface of the distal end section 3c.

[0067] As shown in FIG. 2, the flexible tube 3a in FIG. 1 has a configuration in which a resin layer 15 is coated on the outer peripheral surface of a flexible tube substrate 14. 14a is the distal end (near the distal end 3c) and 14b is the proximal end (near the main body operating unit 5). The flexible tube substrate 14 comprises a helical tube 11 formed by helically winding a metal strip 11a on the innermost side, and a tubular mesh body 12 formed by braiding metal wires. A ferrule 13 is fitted to each end of the helical tube 11. The resin layer 15 is bonded to the flexible tube substrate 14 via a cured adhesive layer 17. The cured adhesive layer 17 can be formed by applying and curing the adhesive of the present invention. While the cured adhesive layer (adhesive portion) 17 is illustrated as a layer of uniform thickness for convenience of illustration, it does not necessarily have to have that shape; it may be an irregular shape interposed between the resin layer 15 and the flexible tube substrate 14. Rather, the resin layer 15 may have almost no thickness, and the resin layer 15 and the flexible tube substrate 14 may be bonded together in a manner that they are substantially in contact with each other. The outer surface of the resin layer 15 is coated with a chemical-resistant coating layer 16 that contains, for example, fluorine. Note that the adhesive cured layer 17, resin layer 15, and coating layer 16 are drawn thicker than the diameter of the flexible tube substrate 14 to clearly illustrate the layer structure.

[0068] 3, the distal end surface of the distal end portion 3c is formed with an illumination window 31, an observation window 32, and a forceps port 33. A nozzle 34 is also formed to deliver water and air for cleaning the distal end surface as needed. The illumination window 31, the observation window 32, the forceps port 33, and the nozzle 34 are connected to the main body operation unit 5 by channels.

[0069] As shown in FIG. 4, the tip portion 3c is composed of a tip portion body 35 made of metal and a tip cap 36 made of an electrically insulating material.

[0070] An observation unit 43, which is an optical system, is installed in the observation window 32. In the observation unit 43, an objective optical system composed of lenses L1 to L5 is fixed in a lens holder 37 by adhesive cured products 41 and 42. These adhesive cured products 41 and 42 can be formed by applying and curing the adhesive of the present invention. In this objective optical system, A is an air space. A prism 38 is bonded and fixed to an end face of the lens holder 37. The optical axis of the objective optical system is bent at a right angle by this prism 38. This prism 38 is fixed to a solid-state image sensor 40. The solid-state image sensor 40 is fixed to a substrate 39. The adhesive of the present invention can also be used to fix these components.

[0071] <Method for Manufacturing an Endoscope> The method for manufacturing an endoscope of the present invention is not particularly limited as long as it includes fixing endoscope components using the adhesive of the present invention. The endoscope of the present invention can be manufactured using standard manufacturing processes for the steps other than fixing the endoscope components. The materials of the endoscope components to be fixed are not particularly limited, and examples include resin components, metal components, and glass components. The endoscope components can be fixed to a support member or other component constituting the endoscope by, for example, mixing the components contained in the adhesive of the present invention, preferably under reduced pressure, injecting or applying the mixture to the application site, and heating at −10 to 60°C (preferably 0 to 60°C, more preferably 10 to 50°C) for 1.5 to 200 hours. Specific examples of how the adhesive can be used in the method for manufacturing an endoscope of the present invention are described below, but the present invention is not limited thereto.

[0072] Among the endoscope components that can be fixed with the adhesive of the present invention, examples of resin components include a tube inserted into the insertion portion of an endoscope. Examples of resin materials that can be used to make the tube include fluororesins such as Teflon (registered trademark), polysulfone, polyester, polyolefin, and silicone. The adhesive of the present invention can be used, for example, to bond the tube to a metal or glass member that makes up the insertion portion of an endoscope (fixing the metal or glass member to the tube). As described above, the adhesive can also be used to form the adhesive cured layer 17 in FIG. 2 . It can also be used to bond the resin layer 15 and coating layer 16 in FIG. 2 .

[0073] The adhesive of the present invention can be used to finish the outer surface of and secure the end of the flexible outer tube (resin layer 15) (the end on the distal end side (angle portion 3b side) of the flexible tube 3a). Specifically, the end of the resin layer 15 of the flexible tube 3a is tied tightly with thread from the outside and secured to an inner member, and then an adhesive is applied to cover the thread and allowed to harden. By forming the outermost layer of the distal end of the flexible tube 3a with the adhesive of the present invention, the thread at the distal end side is made less likely to fray, making it easier to insert the insertion section into a body cavity. The adhesive of the present invention can also be used to bond the distal end portion 3c to the angle portion 3b and / or the insertion section 3 to the main body operating section 5. For example, the distal end portion 3c and the angle portion 3b can be bonded using the adhesive of the present invention, and then the bonded portion between the distal end portion 3c and the angle portion 3b and the vicinity thereof can be reinforced with thread, and then the adhesive is applied to cover the thread and allowed to harden. The same applies to the bonding between the insertion section 3 and the main body operating section 5. The adhesive of the present invention can also be used to fix various tubes inserted into the insertion portion of an endoscope to at least one of the tip portion 3c and the main body operation portion 5.

[0074] The adhesive of the present invention is also preferably used to seal the illumination window 31 and the observation window 32 (fixing glass members) at the tip 3c. Applying a thick layer of adhesive can smooth the outer corners of the lenses and block light from entering the lenses from the lateral direction. The adhesive of the present invention can also be used to secure members, such as when assembling an imaging device built into the tip 3c, bonding components, and sealing a solid-state imaging element 40. The imaging device includes an optical system consisting of multiple optical components such as lenses L1-L5 and a prism 38, and a solid-state imaging element 40 such as a CCD (charge-coupled device) that photoelectrically converts optical images formed by the optical system into imaging signals. The adhesive of the present invention can be used to bond optical components such as lenses L1-L5 and prism 38 made of glass or other materials, as well as to bond lenses L1-L5, prism 38, etc. to a substrate 39 made of resin or metal. This bonding can secure glass members and metal members. The adhesive of the present invention can also be used to bond and fix the solid-state imaging element 40 to the substrate 39 and seal them. This adhesion can secure the metal members that make up the solid-state imaging element, substrate, and the like. Thus, the method for manufacturing an endoscope of the present invention includes a step of fixing the endoscope components using the adhesive of the present invention. In particular, the adhesive of the present invention is suitable for bonding the tip cap 36 at the tip portion 3c to the illumination window 31 and observation window 32, which are made of glass or other material, and at least one of the lenses L1 to L5 and prism 38.

[0075] [Endoscope System] The endoscope system of the present invention can adopt a configuration related to a typical endoscope system, except that it includes the endoscope of the present invention and a light source device having a light source for white irradiation light.

[0076] An example of an endoscopic system of the present invention will be described. The endoscopic system of the present invention includes an endoscope of the present invention, a light source device having a light source for white illumination light, a processor, a display, an operation input unit, and a universal cord. The endoscope captures images of an object to be observed inside a living body. The light source device supplies the endoscope with white illumination light for illuminating the object to be observed. The processor functions as a central control unit that controls the image capture and illumination light, etc., and also processes image signals obtained by the image capture to generate display images, etc. The processor is electrically connected to the display and the operation input unit. The display displays images captured by the endoscope as well as image information associated with the images. The operation input unit functions as a user interface that accepts input operations such as function settings. The universal cord is a cord through which a communication cable and a light guide, etc. extending from the insertion section are inserted, and connects the endoscope to the processor and light source. Therefore, the endoscope has a light guide that guides the illumination light. Note that an external recording unit that records images, image information, etc. may be connected to the processor.

[0077] The endoscope is optically connected to the light source device and electrically connected to the processor device. The endoscope has an insertion section that is inserted into the subject, an operation section provided at the base end of the insertion section, and a bending section and a tip section provided at the tip end of the insertion section. The bending section is bent by operating the angle knob of the operation section. This bending operation allows the tip section to be directed in a desired direction. In addition to the angle knob, the operation section is also provided with a zoom operation section and the like.

[0078] In the endoscope system of the present invention, observation is performed using white illumination light supplied from a light source device (white light observation). The light source of the light source device can be any light source that can supply white light to the endoscope, and for example, a white light source such as a halogen lamp or a xenon lamp can be used.

[0079] Alternatively, white illumination light may be generated by controlling the amount of light emitted by each of a plurality of semiconductor light sources (preferably LEDs (Light Emitting Diodes)) and combining the light of each color using a combining element such as a dichroic filter. The combining element is an optical element having a wavelength-selective function, i.e., an optical element that reflects light in a specific wavelength range and transmits light in a specific wavelength range when light is incident on the combining element. Even when the plurality of semiconductor light sources emit light in different directions, white illumination light can be generated by combining the light and directing it into a condenser lens, depending on the wavelength-selective function of each combining element and the arrangement of the combining elements. As a light source device that generates white illumination light using such a plurality of semiconductor light sources, the description of a light source device for an endoscope that generates white illumination light, as disclosed in Japanese Patent Application Laid-Open No. 2013-109319, may be applied.

[0080] An example of an endoscope light source device that generates white illumination light by combining light of each color using multiple semiconductor light sources includes a plurality of first semiconductor light sources that emit light in different wavelength ranges, an illumination light generation unit that generates white illumination light from the light emitted by the multiple first semiconductor light sources, and a light source attachment unit configured to detachably attach a second semiconductor light source, wherein the illumination light generation unit generates white illumination light from the light emitted by the multiple first semiconductor light sources and the light emitted by the second semiconductor light sources when the second semiconductor light source is attached to the light source attachment unit. The illumination light generation unit includes a combining member, a collimator lens, and a condenser lens. The combining member is preferably a dichroic filter, which has the property of transmitting light in a specific wavelength range and reflecting light in a specific wavelength range so that the light emitted by each of the multiple first semiconductor light sources is incident on the condenser lens to generate illumination light. The collimator lens adjusts the light emitted from each semiconductor light source to parallel light. The condenser lens generates and emits white illumination light from the light emitted by each semiconductor light source that is incident on it.

[0081] In the light source device that generates the above-described white illumination light by combining light beams, preferred specific examples of the semiconductor light source include any one of the following embodiments 1) to 10) or a combination of two or more of these embodiments. 1) The first semiconductor light source emits any one light selected from purple light, blue light, green light, and red light, and the multiple first semiconductor light sources include at least three first semiconductor light sources, and the light emitted by each of the multiple first semiconductor light sources forms a continuous wavelength range. Preferably, the semiconductor light source that emits purple light is a purple LED, the semiconductor light source that emits blue light is a blue LED, the semiconductor light source that emits green light is a green LED, and the semiconductor light source that emits red light is a red LED. This also applies to the following embodiments 2) to 10). 2) The multiple first semiconductor light sources include at least four first semiconductor light sources that emit any one light selected from purple light, blue light, green light, and red light, and the light emitted by each of the multiple first semiconductor light sources forms a continuous wavelength range. 3) When the light emitted by two first semiconductor light sources among the plurality of first semiconductor light sources forms a continuous wavelength range, the wavelength range of the light emitted by the second semiconductor light source includes a wavelength range between the wavelength ranges of the two first semiconductor light sources. Note that, for example, a light blue LED that emits light blue light is preferably used as the second semiconductor light source. This also applies to the following 4) to 10). 4) The plurality of first semiconductor light sources include a first semiconductor light source that emits blue light and a first semiconductor light source that emits green light, and the wavelength range of the light emitted by the second semiconductor light source includes a wavelength range between the wavelength range of the blue light emitted by the first semiconductor light source and the wavelength range of the green light emitted by the first semiconductor light source. 5) The plurality of first semiconductor light sources include a first semiconductor light source that emits green light and a first semiconductor light source that emits red light, and the wavelength range of the light emitted by the second semiconductor light source includes a wavelength range between the wavelength range of the green light emitted by the first semiconductor light source and the wavelength range of the red light emitted by the first semiconductor light source. 6) The plurality of first semiconductor light sources include a first semiconductor light source that emits purple light and a first semiconductor light source that emits blue light, and the wavelength range of the light emitted by the second semiconductor light source includes a wavelength range between the wavelength range of the purple light emitted by the first semiconductor light source and the wavelength range of the blue light emitted by the first semiconductor light source.7) The wavelength range of the light emitted by the second semiconductor light source includes a wavelength range longer than the wavelength range of the light emitted by the plurality of first semiconductor light sources. 8) The wavelength range of the light emitted by the second semiconductor light source includes a wavelength range in the near-infrared range. 9) The wavelength range of the light emitted by the second semiconductor light source includes a wavelength range shorter than the wavelength range of the light emitted by the plurality of first semiconductor light sources. 10) The wavelength range of the light emitted by the second semiconductor light source includes a wavelength range in the ultraviolet range.

[0082] In addition to the above, with regard to the description of the endoscopic system and the light source for supplying white irradiation light to the endoscope, the description of the endoscopic system and the light source for supplying white irradiation light to the endoscope described in JP 2013-109319 A can be preferably applied in accordance with the present invention.

[0083] The present invention will be described in more detail with reference to examples, but the present invention should not be construed as being limited to the following examples. The amount of a component refers to the amount of the component itself. In other words, if the raw material contains a solvent, the amount does not include the solvent.

[0084] Preparation Example 1 Preparation of Adhesive 1 100 parts by mass of bisphenol A diglycidyl ether (trade name: jER828, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 190) as component (A), and 100 parts by mass of polyoxypropylene diamine (trade name: JEFFAMINE) as component (B) were mixed. A mixture was prepared using 40 parts by mass of 40 parts by weight of D-230 (manufactured by HUNTSMAN, active hydrogen equivalent: 60), the parts by mass of the fluorescent organic compound shown in Table 1 below shown in Table 1 below, 25 parts by mass of an inorganic ion exchanger (product name: IXEPLAS-B1, manufactured by Toagosei Co., Ltd., an inorganic compound containing Bi and Zr atoms) as component (D), 10 parts by mass of silica (product name: AEROSIL NAX50, manufactured by Nippon Aerosil Co., Ltd., surface-modified with trimethylsilyl groups, volume-based median diameter (D50) of 30 nm), and 5 parts by mass of carbon black (product name: DENKA BLACK, manufactured by Denka Company, volume-based median diameter (D50) of 35 nm) in a blending ratio of 100 parts by mass. This mixture was degassed for 5 minutes using an Awatori Rentaro ARV-310 (product name, manufactured by Thinky Corporation) at 25°C under reduced pressure of 1.0 Pa while stirring at 2000 rpm to obtain an adhesive.

[0085] [Preparation Example 2] Preparation of adhesive 2 100 parts by mass of bisphenol A diglycidyl ether (trade name: jER828, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 190) as component (A), the parts by mass of the curing agent shown in Table 2 below as shown in Table 2 below, 0.020 parts by mass of 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene (fluorescent organic compound used in No. 102 in Table 1) as component (C), 25 parts by mass of an inorganic amphoteric ion exchanger (trade name: IXEPLAS-B1, manufactured by Toagosei Co., Ltd.) as component (D), 10 parts by mass of silica (trade name: Aerosil NAX50, manufactured by Nippon Aerosil Co., Ltd., surface-modified with trimethylsilyl groups, volume-based median diameter (D50) 30 nm), and 5 parts by mass of carbon black (trade name: Denka Black, manufactured by Denka Company, volume-based median diameter (D50) 35 nm) were mixed in a blending ratio. The resulting mixture was stirred and degassed under reduced pressure by the method described in Preparation Example 1 above to obtain an adhesive.

[0086] In Tables 1 and 2 below, Nos. 101 to 110 are endoscopic adhesives of the present invention, and Nos. c11 to c13 are comparative endoscopic adhesives. These endoscopic adhesives were used to carry out the following evaluations. The obtained evaluation results are summarized in Tables 1 and 2 below.

[0087] [Evaluation 1: Ease of Determining Whether or Not the Adhesive Has Insufficiently Penetrated into the Gap] A minute rectangular hole (a depression the size of GW in FIG. 5 ) measuring 0.2 mm in width (horizontal), 2 mm in length (vertical), and 2 mm in depth was made in the center of one surface of a black fluororubber plate FB (3 mm thick, 20 mm long, 20 mm wide, manufactured by Misumi Corporation). The adhesive prepared above was poured into this hole using a needle, the hole was filled, and the adhesive was cured to produce evaluation sample S1 shown in FIG. 5 . Evaluation sample S1 was irradiated with a UV black light (manufactured by Ichinen TASCO Corporation, light source: UV-LED manufactured by Nichia Corporation, three lamps), and it was determined by visual inspection whether the portion of the hole filled with the adhesive (cured product of the adhesive coating) GW was visible. The above judgment was made for 100 samples, and the percentage of samples in which the portion GW filled with adhesive was visible was applied to the following evaluation criteria to evaluate the ease of determining whether or not the adhesive had insufficiently penetrated into the gaps. - Evaluation criteria - A: 99% or more B: 95% or more but less than 99% C: 90% or more but less than 95% D: 85% or more but less than 90% E: Less than 85%

[0088] [Evaluation 2: Influence on Observed Images in White Light Observation] The adhesive prepared above was applied to a 10 mm x 10 mm area (the area indicated by GC in Figure 6) in the center of one surface of a white fluororubber plate (3 mm thick, 20 mm long, 20 mm wide, manufactured by Misumi Corporation) FW, and cured to produce evaluation sample S2 shown in Figure 6. The obtained evaluation sample S2 was observed under white light in a darkroom environment using an endoscope (manufactured by Fujifilm Corporation, product name: EG-6600R), and it was determined whether or not a glow could be visually observed around the cured product GW of the adhesive-coated product on the observation screen. The above evaluation was performed on 100 samples, and the percentage of samples in which a glow could be visually observed around the cured product GW of the adhesive-coated product was applied to the following evaluation criteria to evaluate the influence on the observed image in white light observation. -Evaluation criteria- A: Less than 1% B: 1% or more and less than 3% C: 3% or more and less than 5% D: 5% or more and less than 7% E: 7% or more

[0089]

[0090]

[0091] Maximum fluorescence wavelength: The maximum fluorescence wavelength in a DMF solution obtained by the above-mentioned measurement method using a spectrofluorometer RF-6000 (trade name, manufactured by Shimadzu Corporation), and the unit is nm. Blend amount: The blend amount per 100 parts by mass of bisphenol A diglycidyl ether (trade name: jER828, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 190) of component (A), and the unit is parts by mass. Note that 0.01 parts by mass means 0.010 parts by mass, 0.1 parts by mass means 0.100 parts by mass, and 0.2 parts by mass means 0.200 parts by mass, respectively.

[0092] [Fluorescent organic compound] 7-(diethylamino)-4-methylcoumarin

[0093] 2,5-bis(5-tert-butyl-2-benzoxazolyl)thiophene

[0094] 4,4'-bis(2-benzoxazolyl)stilbene

[0095] 1,2-bis(5-methyl-2-benzoxazolyl)ethylene

[0096] Fluorescein

[0097] 7-(dimethylamino)-4-methylcoumarin

[0098] 4-methylumbelliferone

[0099] [Curing agent] JEFFAMINE D-230: trade name, manufactured by HUNTSMAN, active hydrogen equivalent: 60

[0100] Gaskamine 328: Trade name, manufactured by Mitsubishi Gas Chemical Company, active hydrogen equivalent: 55

[0101] 2-ethyl-4-methylimidazole

[0102] The results in Tables 1 and 2 reveal the following. Adhesives No. c11 and c12 are not adhesives of the present invention in that they contain a fluorescent organic compound whose maximum fluorescent wavelength in N,N-dimethylformamide solution exceeds 525 nm as a fluorescent organic compound. For these adhesives No. c11 and c12, the content of the fluorescent organic compound per 100 parts by mass of the epoxy resin of component (A) was set to a small amount, 0.01 parts by mass, 0.1 parts by mass, or 0.2 parts by mass, which is a small amount that is unlikely to affect endoscopic observation. It was not possible to easily determine whether the adhesive had insufficiently penetrated into gaps. Furthermore, as the amount of fluorescent organic compound added increased, the influence of the adhesive components on the image observed under white light endoscopic observation increased. Even when the amount added was increased to 0.2 parts by mass, it was not possible to easily determine whether the adhesive had insufficiently penetrated into gaps, and the influence of the adhesive components on the image observed under white light endoscopic observation occurred at a rate of 7%. Furthermore, for adhesives No. c11 and c12, the content of the fluorescent organic compound per 100 parts by mass of the epoxy resin of component (A) was set to a small amount that is unlikely to affect endoscopic observation. Adhesive No. c13 is different from the adhesives of the present invention in that it contains a curing agent that does not have an unsubstituted amino group as a curing agent for the epoxy resin of component (A). With adhesive No. c13, even when the content of the fluorescent organic compound per 100 parts by mass of epoxy resin of component (A) was increased to 0.2 parts by mass, it was not possible to easily determine whether the adhesive had insufficiently penetrated into gaps. In contrast, adhesives Nos. 101 to 108, which are adhesives of the present invention, were able to easily determine whether the adhesive had insufficiently penetrated into gaps, and also suppressed the influence of the adhesive components on images observed under white light endoscopic observation, regardless of whether the content of the fluorescent organic compound per 100 parts by mass of epoxy resin of component (A) was 0.01 parts by mass, 0.1 parts by mass, or 0.2 parts by mass. Furthermore, adhesives No. 101 to 108, which are adhesives of the present invention, were able to easily determine whether the adhesive had insufficiently penetrated into gaps, regardless of whether the content of the fluorescent organic compound per 100 parts by mass of epoxy resin of component (A) was 0.01 parts by mass, 0.1 parts by mass, or 0.2 parts by mass. For adhesives Nos. 109 and 110, when 0.2 parts by mass of a fluorescent organic compound was blended with 100 parts by mass of the epoxy resin of component (A), it was possible to easily determine whether the adhesive had insufficiently penetrated into gaps, and it was also possible to suppress the influence of the adhesive components on the image observed under white light endoscopic observation.In particular, adhesive No. 110, which contains a polyether polyamine compound as a curing agent for the epoxy resin of component (A), was superior to adhesive No. 109, which does not contain a polyether polyamine compound as a curing agent for the epoxy resin of component (A), in that it was possible to more easily determine whether the adhesive had insufficiently penetrated into gaps, and it also better suppressed the influence of the adhesive components on images observed during endoscopic white light observation.

[0103] This application claims priority based on Japanese Patent Application No. 2023-170304, filed on September 29, 2023, the contents of which are incorporated herein by reference as part of the present specification.

[0104] DESCRIPTION OF SYMBOLS 2 Electronic endoscope (endoscope) 3 Insertion section 3a Flexible tube 3b Angle section 3c Tip section 5 Main body operation section 6 Universal cord 11 Spiral tube 11a Metal strip 12 Cylindrical mesh body 13 Mouthpiece 14 Flexible tube base material 14a Tip side 14b Base side 15 Resin layer 16 Coating layer 17 Cured adhesive layer 31 Illumination window 32 Observation window 33 Forceps port 34 Nozzle 35 Tip section main body 36 Tip cap 37 Lens holder 38 Prism 39 Substrate 40 Solid-state imaging element 41 Cured adhesive 42 Cured adhesive 43 Observation unit A Air layer L1 to L5 Lenses FB Black fluororubber plate FW White fluororubber plate GW Cured adhesive filling holes in fluororubber plate GC: Cured adhesive coating S1: Evaluation sample S2: Evaluation sample

Claims

1. An adhesive for endoscopes, comprising the following components (A) to (C): (A) an epoxy resin; (B) a polyamine compound having two or more unsubstituted amino groups; and (C) a fluorescent organic compound having a maximum fluorescent wavelength of 380 to 525 nm in an N,N-dimethylformamide solution.

2. The adhesive for endoscopes according to claim 1, wherein said component (B) comprises a polyether polyamine compound.

3. The adhesive for endoscopes according to claim 1, wherein the content of said component (C) is 0.005 to 0.500 parts by mass per 100 parts by mass of said component (A).

4. The adhesive for endoscopes according to claim 1, which contains 5 to 30 parts by mass of an inorganic amphoteric ion exchanger as component (D) per 100 parts by mass of component (A).

5. An endoscope having components fixed thereto by the adhesive for endoscopes according to any one of claims 1 to 4.

6. A method for manufacturing an endoscope, comprising fixing members together using the adhesive for endoscopes according to any one of claims 1 to 4.

Images