Adhesive for endoscope, cured product, member for endoscope, and endoscope

Abstract

Provided are: an adhesive for an endoscope satisfying condition I or II; a cured product of this adhesive for an endoscope; a member for an endoscope; and an endoscope. (Condition I) The adhesive for an endoscope contains component (A1): at least one epoxy resin selected from a bisphenol A type, a bisphenol F type, and a phenol novolac type, component (B): an amine compound that contains an aliphatic amine compound having a polycyclic hydrocarbon structure, and that serves as a curing component, and component (C): a terminal epoxy compound that is represented by a specific general formula (1) and that serves as a plasticizer, the component (C) content being 60-250 parts by mass with respect to 100 parts by mass of the component (A1) content. (Condition II) The adhesive for an endoscope contains component (A2): an epoxy resin containing at least one of an NBR-modified epoxy compound and a fluorene-type epoxy compound, and the abovementioned component (B).

Description

Endoscope adhesives, cured products, endoscope components, and endoscopes

[0001] The present invention relates to an adhesive for endoscopes, a cured product, an endoscope component, and an endoscope.

[0002] In the manufacture of endoscopes used for observing the body cavities, the digestive tract (esophagus, stomach, intestines, etc.), and the airways (trachea, bronchi, etc.), adhesives are used to assemble and fix the components of the endoscope, and to seal any gaps. Generally, epoxy adhesives are used for bonding the components of endoscopes because they offer excellent workability and their cured products have superior adhesion, heat resistance, gas barrier properties, and water resistance.

[0003] On the other hand, epoxy adhesives used in endoscopes require that the curing temperature be adjusted to be as low as possible (for example, 60°C or below) to prevent the endoscope from being exposed to high temperatures (low-temperature curing properties). As an endoscope adhesive that solves the above low-temperature curing problem, for example, Patent Document 1 describes an endoscope adhesive comprising at least one epoxy resin (A) from among bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin, an amine compound (B), and a compound (C) having a specific structure with epoxy groups. According to Patent Document 1, this endoscope adhesive exhibits a high curing reaction rate even at low temperatures, the cured product after the curing reaction has excellent flexibility, the transparency of the cured product can be sufficiently maintained even when used for a long period of time in this fixed state, and furthermore, the cured product is less likely to deteriorate even when subjected to repeated sterilization treatment (hydrogen peroxide plasma treatment, etc.) in the above fixed state.

[0004] International Publication No. 2020 / 012993

[0005] The disinfection and sterilization of endoscopes after use varies depending on the object being observed. For example, endoscopes used to observe the lungs, such as the trachea and bronchi, are sterilized using EOG (ethylene oxide gas), hydrogen peroxide plasma, etc. Therefore, the adhesive parts of the endoscope components (cured products obtained from endoscope adhesives) are required to be resistant to deterioration from repeated sterilization, as described in Patent Document 1 above. On the other hand, endoscopes used to observe the digestive tract, such as the stomach and intestines, are disinfected using disinfectant water containing glutaraldehyde, o-phthalaldehyde, peracetic acid, etc. Specifically, for the purpose of disinfection in a short time, the endoscope is immersed in heated disinfectant water (approximately 30-65°C), so the adhesive parts of the endoscope components (cured products obtained from endoscope adhesives) are required to be resistant to deterioration from immersion in hot water (hot water resistance). Furthermore, since the trachea and bronchi are cleaner organs compared to the digestive tract, such as the stomach and intestines, endoscopes used to observe the trachea and bronchi do not require water washing; the aforementioned sterilization process is sufficient, and the same level of heat resistance as endoscopes used to observe the digestive tract, such as the stomach and intestines, is not necessary.

[0006] Furthermore, endoscopes used to observe the digestive tract, such as the stomach and intestines, also require water vapor barrier properties (moist heat resistance). In other words, the flexible tube portion of the endoscope is inserted into the digestive tract, and the target internal body part is observed and lesions are treated while irradiating it with strong light. These observations and treatments under strong light are performed while rinsing the observation window (lens) of the flexible tube with water. That is, while inserted into the digestive tract, the endoscope is exposed to heat and moisture from the light source, and is placed in a moist heat environment. Consequently, with repeated observations and lesion treatments, the parts that bond or fix the observation window of the flexible tube (hardened material obtained from endoscope adhesive) deteriorate, making it easier for water vapor to seep into the inside of the flexible tube. As a result, the deterioration of the various components that make up the endoscope is also accelerated. Moreover, if water vapor seeps into the inside of the flexible tube due to exposure to the above moist heat environment, water droplets will remain inside the flexible tube when it is returned to a room temperature environment. For this reason, excellent water vapor barrier properties are required from a hygienic standpoint.

[0007] Through repeated investigations, the inventors have found that while the endoscope adhesive described in Patent Document 1 exhibits excellent low-temperature curing properties, the resulting cured product does not necessarily achieve the desired level of water vapor barrier properties and hot water resistance.

[0008] The present invention aims to provide an endoscopic adhesive and its cured product, which, when cured by a curing reaction at low temperatures, exhibits excellent water vapor barrier properties and excellent hot water resistance. Furthermore, the present invention aims to provide an endoscopic component or endoscope, wherein the cured product immobilizes constituent materials using the above-mentioned cured product, and the cured product exhibits excellent water vapor barrier properties and excellent hot water resistance.

[0009] As a result of diligent research, the inventors have found that an endoscope adhesive containing an epoxy resin, an amine compound containing an aliphatic amine compound of a specific structure, and a terminal epoxy compound of a specific structure acting as a plasticizer, wherein the content of the plasticizer relative to the epoxy resin is controlled within a specific range, and an endoscope adhesive containing an epoxy resin having a specific structure and an amine compound containing an aliphatic amine compound of a specific structure, cures with a high curing reaction rate even at low temperatures, and the cured product obtained by the curing reaction at low temperatures exhibits excellent water vapor barrier properties and hot water resistance. The present invention was completed after further research based on these findings.

[0010] The above problems of the present invention have been solved by the following means. <1> An adhesive for endoscopes that satisfies the following conditions I or II. (Condition I) Containing the following components (A1) to (C), Component (A1): At least one epoxy resin component selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin (B): An amine compound component which is a curing component of the epoxy resin (C): A terminal epoxy compound represented by the following general formula (1) which is a plasticizer. Component (B) contains an aliphatic amine compound having a polycyclic hydrocarbon structure, and the content of component (C) is 60 to 250 parts by mass per 100 parts by mass of component (A1). In the formula, n is an integer from 1 to 6. R represents an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group, or a group that is a combination of these groups, and has a valency of n. However, R does not adopt a -phenylene-methylene-phenylene- structure, does not adopt a -phenylene-dimethylmethylene-phenylene- structure, does not have an acrylonitrile butadiene copolymer structure, does not have a fluorene skeleton, and does not bond with the epoxy group in the formula to form a ring. (Condition II) Contains the following components (A2) and (B). Component (A2): Epoxy resin component containing at least one of an acrylonitrile butadiene rubber-modified epoxy compound and an epoxy compound having a fluorene skeleton. (B): Amine compound which is a curing component of the epoxy resin. Component (B) contains an aliphatic amine compound having a polycyclic hydrocarbon structure. <2> The endoscopic adhesive according to <1>, wherein component (C) does not contain heteroatoms other than oxygen atoms derived from an epoxy group or a glycidyl ether group. <3> The endoscopic adhesive according to <1>, wherein the proportion of the acrylonitrile butadiene rubber-modified epoxy compound in the above component (A2) is 20 to 50% by mass. <4> The endoscopic adhesive according to <1> or <3>, wherein the above component (A2) contains at least the acrylonitrile butadiene rubber-modified epoxy compound, and further contains 10 to 60 parts by mass of the following component (C) per 100 parts by mass of the above component (A2). Component (C): A plasticizer, a terminal epoxy compound represented by the above general formula (1). <5> The endoscopic adhesive according to any one of <1>, <3> or <4>, wherein the above component (A2) contains at least the epoxy compound having the above fluorene skeleton, and the epoxy equivalent of the above component (A2) is 280 to 420. <6> The endoscopic adhesive according to any one of <1> to <5>, wherein the endoscopic adhesive described above has a water absorption rate of less than 5.0% by mass when the cured product obtained by curing the endoscopic adhesive to a 100% curing rate is immersed in 60°C water for 24 hours. <7> The endoscopic adhesive according to any one of <1> to <6>, wherein the endoscopic adhesive described above has a glass transition temperature of 40 to 80°C when the cured product obtained by curing the endoscopic adhesive to a 100% curing rate is 40 to 80°C.<8> An endoscope adhesive according to any one of <1> to <7>, further comprising the following component (D): Component (D): At least one of a curing accelerator, an adhesion improver, and a filler. <9> A cured product obtained by curing the endoscope adhesive according to any one of <1> to <8>. <10> An endoscope component in which the constituent materials are fixed by the cured product according to <9>. <11> An endoscope comprising the endoscope component according to <10> as a constituent component.

[0011] In the present invention, when describing physical properties, etc., by indicating numerical ranges, if the upper and lower limits of the numerical range are described separately, either upper or lower limit can be appropriately combined to form a specific numerical range. On the other hand, when describing multiple numerical ranges represented by "~", the upper and lower limits forming the numerical range are not limited to the specific combination of upper and lower limits described before and after "~" as a specific numerical range, but can be a numerical range formed by appropriately combining the upper and lower limits of each numerical range. In the description of the present invention, "~" is used to mean that the numerical values ​​described before and after it are included as the lower and upper limits. In the endoscopic adhesive of the present invention, each component (in adhesive I of the present invention, components (A1) to (C) and an arbitrary component such as component (D), and in adhesive I of the present invention, components (A2) and (B) and an arbitrary component such as components (C) and (D)) may be used individually or mixed in groups of two or more, unless otherwise specified. In the present invention, when there are multiple substituents, linking groups, or structural units (hereinafter referred to as substituents, etc.) represented by a specific symbol or formula, or when multiple substituents, etc. are specified simultaneously, unless otherwise specified, each substituent, etc. may be identical or different from the others. The same applies to the specification of the number of substituents, etc. Furthermore, when multiple substituents, etc. are in close proximity (especially adjacent), unless otherwise specified, they may be linked to each other to form a ring. Furthermore, unless otherwise specified, rings, such as alicyclic rings, aromatic rings, and heterocyclic rings, may be further fused to form a fused ring. In this specification, substituents (and linking groups) that are not specified as substituted or unsubstituted may have any substituents as long as the desired effect is achieved. Examples of such substituents include substituents selected from the substituent group T described later. The same applies to compounds that are not specified as substituted or unsubstituted. In this specification, when the number of carbon atoms of a group is specified, this number of carbon atoms refers to the total number of carbon atoms of the group. That is, if the group has further substituents, this refers to the total number of carbon atoms including these substituents.

[0012] The adhesive for endoscopes of the present invention, when cured by a curing reaction at low temperatures, exhibits excellent water vapor barrier properties and excellent resistance to hot water. Furthermore, the cured product of the present invention exhibits excellent water vapor barrier properties and excellent resistance to hot water. Therefore, the cured product in an endoscope component or endoscope of the present invention, in which the constituent materials are fixed by this cured product, exhibits excellent water vapor barrier properties and excellent resistance to hot water.

[0013] This is an external view showing the configuration of one embodiment of the endoscope of the present invention. This is a partial cross-sectional view showing the configuration of the insertion section of the endoscope shown in Figure 1. This is an external perspective view of the tip of the insertion section. This is a partial cross-sectional view of a partially cut-out portion of the tip. Hatching showing the cross-sections of the lens and prism has been omitted. This is a schematic longitudinal cross-sectional view of the test sample used in Evaluation 1 of the Example. This is a schematic diagram of the adhesive test piece used in Evaluation 2 of the Example.

[0014] [Endoscope Adhesive] The endoscopic adhesive of the present invention (hereinafter also referred to as "the adhesive of the present invention") is an endoscopic adhesive that satisfies the following conditions I or II. (Condition I) It contains the following components (A1) to (C): Component (A1): At least one epoxy resin component from among bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin (B): Amine compound component which is a curing component of the epoxy resin (C): A terminal epoxy compound represented by the general formula (1) below, which is a plasticizer. Component (B) contains an aliphatic amine compound having a polycyclic hydrocarbon structure, and the content of component (C) is 60 to 250 parts by mass per 100 parts by mass of component (A1). (Condition II) It contains the following components (A2) and (B). Component (A2): An epoxy resin component comprising at least one of an acrylonitrile butadiene rubber-modified epoxy compound (also referred to as "NBR-modified epoxy compound") and an epoxy compound having a fluorene skeleton (also referred to as "fluorene-type epoxy compound"). Component (B): An amine compound which is a curing component of the epoxy resin. Component (B) contains an aliphatic amine compound having a polycyclic hydrocarbon structure. Among the adhesives of the present invention, those satisfying condition I are referred to as Adhesive I of the present invention, and those satisfying condition II are referred to as Adhesive II of the present invention. In Adhesive I of the present invention, component (A1) is an epoxy resin and is the main component of the adhesive. In Adhesive II of the present invention, component (A2) is an epoxy resin and is the main component of the adhesive. Component (B) is a curing component that reacts with the epoxy resin to cure the adhesive. In addition to the main component and curing component, Adhesive I of the present invention further contains the plasticizer component (C). In the present invention, this plasticizer is a terminal epoxy compound. In the following description, when simply referred to as component (A), it means component (A1) in Adhesive I of the present invention, and component (A2) in Adhesive II of the present invention.

[0015] The adhesive of the present invention is not limited in form as long as it contains the above-mentioned components. For example, adhesive I of the present invention may be in a form containing a mixture of the above-mentioned components (A1), (B), and (C) (one-component type), or it may contain components (A1), (B), and (C) in a state in which some of the components (A1), (B), and (C) are separated from the other components (two-component type). Alternatively, adhesive I of the present invention may contain components (A1), (B), and (C) in a state in which each of the components (A1), (B), and (C) is separated from each other (three-component type). Any of these forms are encompassed by adhesive I of the present invention. It is preferable that the plasticizer of component (C) is uniformly dispersed in the adhesive and the cured product in the state in which components (A1), (B), and (C) are mixed (before curing) and in the state of the cured product after curing. For example, Adhesive II of the present invention may be in a form containing a mixture of the above components (A2) and (B) (and possibly component (C) described later) (one-component type), or it may contain components (A2) and (B) (and possibly component (C) described later) in a state in which some of the above components (A2) and (B) (and possibly component (C) described later) are separated from the other components (two-component type). Also, if Adhesive II of the present invention contains component (C), it may contain components (A2), (B), and (C) in a state in which each of the components (A2), (B), and (C) is separated from each other (three-component type). Any of these forms are encompassed by Adhesive II of the present invention. If component (C) is included, it is preferable that the plasticizer of component (C) is uniformly dispersed in the adhesive and the cured product in the state in which components (A2), (B), and (C) are mixed (before curing) and in the state of the cured product after curing. When describing the content of each component in the adhesive in this specification, or when specifying the content of each component in the adhesive in the present invention, in the case of two-component and three-component forms, it means that the mixing of components (A) to (C) at the time of use is performed so that each component in the mixture satisfies the desired content described later. In other words, when the components are separated, the content of each component (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 form of two-component and three-component types, this means that the content of components (A) to (C) is satisfied at the time of mixing when used, as described herein or as defined in the present invention.

[0016] When the endoscopic adhesive of the present invention is a one-component type, or when it is a two-component type or the like, but contains components that can react with each other (for example, when component (A) is an epoxy resin and component (B) is its curing component), it is preferable to store the adhesive at a low temperature to a level where no reaction occurs, in order to maintain a stable state of each component by preventing or sufficiently suppressing reactions between the components. For example, it can be stored at 0°C or below, -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 place if necessary.

[0017] Adhesive I of the present invention preferably contains, in addition to the above components (A1), (B), and (C), at least one of the following components (D): curing accelerator, adhesion improver, and filler. Adhesive II of the present invention preferably contains, in addition to the above components (A2) and (B), and component (C) which may be included, at least one of the following components (D): curing accelerator, adhesion improver, and filler. Furthermore, in addition to the above components (A) to (D), the adhesive of the present invention may contain, to the extent that it does not impair the effects of the present invention, for example, solvents, plasticizers (excluding the plasticizer of component (C)), surfactants, colorants (pigments, dyes, etc.), weathering agents, antioxidants, heat stabilizers, lubricants, antistatic agents, mold release agents, conductive agents, viscosity modifiers, thixotropic agents, diluents, and flame retardants.

[0018] Adhesives I and II of the present invention possess properties that could not be predicted from conventional knowledge, namely that the cured product obtained by a curing reaction at low temperatures exhibits excellent water vapor barrier properties and excellent hot water resistance. The reason for this is presumed to be due to the use of a component (component (B)) containing an aliphatic amine compound having a polycyclic hydrocarbon structure with high hydrophobicity and bulkiness, and is thought to be as follows: Adhesive I of the present invention uses a component (component (B)) containing an aliphatic amine compound having a polycyclic hydrocarbon structure with high hydrophobicity and bulkiness as the curing component of the epoxy resin of component (A1), and it is thought that the characteristic chemical structure of this component (B) contributes to the improvement of the water vapor barrier properties and hot water resistance of the cured product obtained by the curing reaction. Here, since the molecular chain mobility of the adhesive of the present invention containing component (B) containing the aliphatic amine compound having the above-mentioned polycyclic hydrocarbon structure is low, in order to fully bring out the improvement of water vapor barrier properties and hot water resistance, it is necessary to perform the curing reaction at a high temperature of approximately 80°C or higher and cure it with a high curing rate. In this regard, adhesive I of the present invention, by containing a specific amount of a terminal epoxy compound, which is the plasticizer of component (C), can achieve a high curing rate even in low-temperature ranges, and is thought to be able to achieve excellent water vapor barrier properties and excellent hot water resistance while suppressing damage to endoscopes (precision instruments) due to high-temperature exposure during the curing reaction. The terminal epoxy compound, which is the plasticizer of component (C), is incorporated into the cured product by chemical bonding and is not easily bleed-out. This is also thought to contribute to the manifestation of the above effects. Furthermore, adhesive II of the present invention uses a component (component (B)) containing an aliphatic amine compound having a polycyclic hydrocarbon structure with high hydrophobicity and bulkiness as the curing component of the epoxy resin of component (A2). The characteristic chemical structure of this component (B) is thought to contribute to improving the water vapor barrier properties and hot water resistance of the cured product obtained by the curing reaction. Here, since the adhesive of the present invention containing component (B) which contains the aliphatic amine compound having the polycyclic hydrocarbon structure described above has low molecular chain mobility, in order to fully bring out the improved water vapor barrier properties and hot water resistance, it is necessary to perform the curing reaction at a high temperature of approximately 80°C or higher and cure it with a high curing rate.The NBR-modified epoxy compound that component (A2) may contain exhibits high hydrophobicity and high molecular chain mobility (a flexible structure) due to its acrylonitrile butadiene rubber structure. Therefore, it is believed that a high curing rate can be achieved even at low temperatures, while simultaneously minimizing damage to endoscopes (precision instruments) caused by high-temperature exposure during the curing reaction, and achieving high water vapor barrier properties and hot water resistance. Furthermore, the fluorene-type epoxy compound that component (A2) may contain exhibits high hydrophobicity and strong intermolecular interactions due to its fluorene skeleton structure, which suppresses the approach (adsorption, permeation) of water molecules. It is also hypothesized that the molecules approach each other, increasing reactivity at low temperatures. Therefore, it is believed that a high curing rate can be achieved even at low temperatures, while simultaneously minimizing damage to endoscopes (precision instruments) caused by high-temperature exposure during the curing reaction, and achieving high water vapor barrier properties and hot water resistance. In addition, since the manufacturing of endoscope components and endoscopes requires the precise assembly of minute parts smaller than 5 mm, the adhesive used must have good handling properties during application. However, both NBR-modified epoxy compounds and fluorene-type epoxy compounds tend to string easily, so their use in endoscopic adhesives has been avoided. The present invention has shown that by using such NBR-modified epoxy compounds and / or fluorene-type epoxy compounds, a cured product can be obtained that exhibits excellent water vapor barrier properties and excellent hot water resistance.

[0019] The adhesive of the present invention is suitable for fixing various components that constitute an endoscope or endoscope components. That is, the adhesive of the present invention is suitable for fixing various components that constitute an endoscope or endoscope components by bonding (joining) them to other components of the endoscope. The adhesive used to fix various components that constitute an endoscope or endoscope components hardens and forms the bonded part of the endoscope. In particular, the adhesive of the present invention can be suitably used to fix various components that constitute an endoscope or endoscope components, where excellent water vapor barrier properties and excellent hot water resistance are required due to fixation at low temperatures. There are no particular restrictions on the components that are fixed using the adhesive of the present invention, but preferably examples include metal materials such as stainless steel, glass materials, resin materials, etc., and it can be used to fix components made of these components. The "fixing" of various components that constitute an endoscope or endoscope components is performed by bonding the various components that constitute an endoscope or endoscope components to another component (support member) that constitutes the endoscope. The support member may be the tube wall of the endoscope or a non-movable member fixed to the tube wall, etc., or it may be a member whose relative position within the endoscope can move, such as a tube. Furthermore, in this invention, the term "fixation" includes filling the space between the constituent members of the endoscope and the support member into which these members are incorporated with a cured adhesive, i.e., sealing it. The components constituting the adhesive of this invention are described below.

[0020] <Component (A)> (Component (A1)) Adhesive I of the present invention contains at least one epoxy resin selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin as component (A1). Adhesive I of the present invention may contain one epoxy resin selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin alone, or it may contain two or more. Adhesive I of the present invention does not contain either the NBR-modified epoxy compound or the fluorene-type epoxy compound contained as component (A2) in Adhesive II of the present invention. The epoxy equivalent of the epoxy resin contained in Adhesive I of the present invention is preferably 10 to 1000, more preferably 50 to 500, even more preferably 80 to 400, and particularly preferably 100 to 300. The epoxy resin contained in Adhesive I of the present invention usually has two or more epoxy groups in one molecule. 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.

[0021] The above-mentioned bisphenol A type epoxy resin is not particularly limited, and those commonly used as the main component of epoxy adhesives can be widely used. Preferred specific examples include bisphenol A diglycidyl ether (jER825, jER828, and jER834 (all trade names, manufactured by Mitsubishi Chemical Corporation)) and bisphenol A propoxylate diglycidyl ether (for example, manufactured by Sigma-Aldrich).

[0022] The above-mentioned bisphenol F type epoxy resin is not particularly limited, and any resin commonly used as a main component in epoxy adhesives can be widely used. A preferred specific example is bisphenol F diglycidyl ether (for example, EPICLON 830 (trade name) manufactured by DIC Corporation).

[0023] The phenol novolac type epoxy resin mentioned above is not particularly limited, and any resin commonly used as a main component in epoxy adhesives can be widely used. Such a phenol novolac type epoxy resin is, for example, sold by Sigma-Aldrich under product number 406775.

[0024] The epoxy resin content as component (A1) in adhesive I of the present invention can be 5 to 62% by mass, more preferably 10 to 62% by mass, even more preferably 15 to 62% by mass, and particularly preferably 20 to 62% by mass.

[0025] (Component (A2)) The adhesive II of the present invention contains an epoxy resin as component (A2) which includes at least one of NBR-modified epoxy compounds and fluorene-type epoxy compounds. The adhesive II of the present invention may contain one epoxy resin selected from NBR-modified epoxy compounds and fluorene-type epoxy compounds alone, or it may contain two or more. The epoxy resin contained in the adhesive II of the present invention usually has two or more epoxy groups in one molecule. As described later, the adhesive II of the present invention may further contain at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin as component (A2), in addition to at least one of NBR-modified epoxy compounds and fluorene-type epoxy compounds. That is, if the adhesive of the present invention contains at least one of NBR-modified epoxy compounds and fluorene-type epoxy compounds, and at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin, it is classified as adhesive II of the present invention and not adhesive I of the present invention.

[0026] When the adhesive II of the present invention contains the above-mentioned NBR-modified epoxy compound as component (A2), excellent water vapor barrier properties and even better hot water resistance can be achieved. The above-mentioned NBR-modified epoxy compound refers to a compound in which two or more epoxy groups are introduced into acrylonitrile butadiene rubber (acrylonitrile butadiene copolymer), and compounds in which epoxy groups are introduced into both ends of acrylonitrile butadiene rubber (acrylonitrile butadiene copolymer) are known. The above-mentioned NBR-modified epoxy compound is not particularly limited, and those commonly used as the main ingredient in epoxy adhesives can be widely used. When component (A2) contains the above-mentioned NBR-modified epoxy compound, it is preferable to further include epoxy resins other than the above-mentioned NBR-modified epoxy compound, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin in component (A1) above. In such a mixed epoxy resin composition, the NBR-modified epoxy compound is a relatively soft epoxy resin, while the bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, and phenol novolac-type epoxy resin in component (A1) described above are relatively hard epoxy resins. The case where a fluorene-type epoxy compound is further included is described below. The proportion of the NBR-modified epoxy compound in component (A2) is preferably 20 to 50% by mass, more preferably over 25% by mass and 50% by mass or less, even more preferably 30 to 50% by mass, and particularly preferably 35 to 45% by mass. The epoxy equivalent of the above NBR-modified epoxy compound is preferably 400 to 20,000, more preferably 400 to 10,000, even more preferably 400 to 5,000, and particularly preferably 400 to 3,000. When component (A2) contains the above NBR-modified epoxy compound, the epoxy equivalent of the epoxy resin (i.e., component (A2)) contained in adhesive II of the present invention is preferably 200 to 20,000, more preferably 200 to 10,000, even more preferably 200 to 5,000, and particularly preferably 200 to 3,000. Note that 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.When two or more epoxy compounds are included, it means the epoxy equivalent of the entire epoxy resin. The same meaning applies hereafter. Preferred specific examples of the above NBR-modified epoxy compound used in component (A2), or a mixture of the above NBR-modified epoxy compound and at least one of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin, include EPOX MK SR35K (trade name, manufactured by Printec Co., Ltd.), Adeka Resin EPR-1415-1, Adeka Resin EPR-2000, Adeka Resin EPR-2007, and Adeka Resin EPR-4030 (all trade names, manufactured by ADEKA Corporation).

[0027] Adhesive II of the present invention preferably contains at least the NBR-modified epoxy compound as component (A2), and more preferably contains 10 to 60 parts by mass of component (C) described later per 100 parts by mass of component (A2), wherein the proportion of the NBR-modified epoxy compound in component (A2) is more than 25% by mass and 50% by mass or less, and more preferably contains 10 to 60 parts by mass of component (C) described later per 100 parts by mass of component (A2). In this case, it is even more preferable that the content of component (C) described later per 100 parts by mass of component (A2) is 15 to 55 parts by mass.

[0028] When the adhesive II of the present invention contains the above-mentioned fluorene-type epoxy compound as component (A2), excellent hot water resistance and even better water vapor barrier properties can be achieved. The above-mentioned fluorene-type epoxy compound means a compound having a fluorene skeleton and two or more epoxy groups, and compounds in which two or more groups containing epoxy groups are linked to the 9th position of the fluorene skeleton are known. The above-mentioned fluorene-type epoxy compound is not particularly limited, and those commonly used as the main ingredient in epoxy adhesives can be widely used. As an example of a compound in which two or more groups containing epoxy groups are linked to the 9th position of the fluorene skeleton, there is a compound in which two groups represented by *-arylene-polyalkylene glycol structure-epoxy (* indicates a bond) are linked to the 9th position of the fluorene skeleton. Examples of arylene include phenylene and naphthylene, with phenylene being preferred. The polyalkylene glycol structure means a structure represented by -O-alkylene, or a structure in which 2 to 10 -O-alkylene structures are linked together. If component (A2) contains the above-mentioned fluorene-type epoxy compound, it may further contain epoxy resins other than the above-mentioned fluorene-type epoxy compound. Examples of epoxy resins other than the above-mentioned fluorene-type epoxy compound include the bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin in component (A1) described above. In such a mixed epoxy resin configuration, the fluorene-type epoxy compound is a relatively hard epoxy resin, and the bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin in component (A1) described above are relatively soft epoxy resins. The case in which an NBR-modified epoxy compound is further included is described below. The proportion of the fluorene-type epoxy compound in component (A2) is preferably 20% by mass or more, more preferably 50% by mass or more, and even more preferably 65% ​​by mass or more. It is also possible that all of component (A2) is the above-mentioned fluorene-type epoxy compound. The epoxy equivalent of the above fluorene-type epoxy compound is preferably 220 to 1000, more preferably 250 to 800, and even more preferably 280 to 500.When component (A2) contains the above-mentioned fluorene-type epoxy compound, the epoxy equivalent of the epoxy resin (i.e., component (A2)) contained in adhesive II of the present invention is preferably 280 to 420, more preferably 310 to less than 400, even more preferably 320 to 390, and particularly preferably 330 to 390, from the viewpoint of superior resistance to hot water. Preferred specific examples of the above-mentioned fluorene-type epoxy compound include Ogusol EG-200 and Ogusol EG-280 (both trade names, manufactured by Osaka Gas Chemical Co., Ltd.) and TBIS-GG (trade name, manufactured by Taoka Chemical Industry Co., Ltd.).

[0029] The above description of the NBR-modified epoxy compound describes a form in which component (A2) contains the NBR-modified epoxy compound but does not contain the fluorene-type epoxy compound, while the description of the fluorene-type epoxy compound describes a form in which component (A2) does not contain the NBR-modified epoxy compound but contains the fluorene-type epoxy compound. Below, we will describe a form in which component (A2) contains both the NBR-modified epoxy compound and the fluorene-type epoxy compound. When adhesive II of the present invention contains both the NBR-modified epoxy compound and the fluorene-type epoxy compound as component (A2), it is possible to achieve a good balance between excellent hot water resistance and excellent water vapor barrier properties. When describing the case in which component (A2) contains both the NBR-modified epoxy compound and the fluorene-type epoxy compound, the epoxy equivalents of component (A2) and the proportion of each epoxy compound in component (A2) are as follows. The descriptions of the NBR-modified epoxy compound and the fluorene-type epoxy compound are as described above. The epoxy equivalent of the epoxy resin (i.e., component (A2)) contained in adhesive II of the present invention is preferably 300 to 420, more preferably 320 to 420, even more preferably 350 to 420, and particularly preferably 380 to 420. The proportion of the NBR-modified epoxy compound in component (A2) is preferably, for example, 10 to 90% by mass, more preferably 20 to 80% by mass, and even more preferably 30 to 70% by mass. The proportion of the fluorene-type epoxy compound in component (A2) is preferably, for example, 10 to 90% by mass, more preferably 20 to 80% by mass, and even more preferably 30 to 70% by mass. Furthermore, epoxy resins other than the NBR-modified epoxy compound and the fluorene-type epoxy compound may also be further contained, for example, the bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin in component (A1) described above. The proportion of epoxy resins other than NBR-modified epoxy compounds and fluorene-type epoxy compounds in component (A2) is preferably 80% by mass or less, more preferably 60% by mass or less, and even more preferably 40% by mass or less. There is no particular limit on the lower limit, for example, a range of 5 to 40% by mass is preferred.

[0030] The epoxy resin content as component (A2) in adhesive II of the present invention can be 50 to 95% by mass, more preferably 60 to 95% by mass, even more preferably 70 to 95% by mass, and particularly preferably 75 to 95% by mass.

[0031] <Component (B)> The adhesive of the present invention contains an amine compound as component (B), which is a curing component of epoxy resin, and this amine compound includes an aliphatic amine compound having a polycyclic hydrocarbon structure. As described above, by including an aliphatic amine compound having a polycyclic hydrocarbon structure in component (B), a cured product with excellent water vapor barrier properties and hot water resistance can be obtained due to the polycyclic hydrocarbon structure, and the reactivity with epoxy resin is enhanced because it is an aliphatic amine compound. The adhesive of the present invention may contain one aliphatic amine compound having a polycyclic hydrocarbon structure alone, or it may contain two or more in combination. Furthermore, the adhesive of the present invention may also contain one or more amine compounds other than aliphatic amine compounds having a polycyclic hydrocarbon structure (hereinafter also referred to as "other amine compounds") as component (B) for the purpose of adjusting the physical properties of the adhesive.

[0032] (Aliphatic amine compounds having a polycyclic hydrocarbon structure) The amino group in aliphatic amine compounds having a polycyclic hydrocarbon structure is an unsubstituted amino group (-NH ２) The amino group of an aliphatic amine compound having a polycyclic hydrocarbon structure may be bonded to an aliphatic hydrocarbon or an alicyclic hydrocarbon. The aliphatic amine compound having a polycyclic hydrocarbon structure may be monofunctional or polyfunctional, preferably monofunctional or difunctional, and more preferably difunctional. When the aliphatic amine compound having a polycyclic hydrocarbon structure is difunctional, the resulting cured product can have crosslinked molecular chains and a dense network structure, thereby further enhancing its water vapor barrier properties. The way in which the rings constituting the polycyclic hydrocarbon structure are bonded together may be a condensed ring, a bicyclo ring, a tricyclo ring, or any other bridged ring, where two adjacent monorings share a C-C bond or a C=C bond, or both. As long as the polycyclic hydrocarbon structure of an aliphatic amine compound having a polycyclic hydrocarbon structure has two or more condensed rings or bridged rings, the rings constituting the polycyclic hydrocarbon structure may be either aliphatic hydrocarbon rings or aromatic hydrocarbon rings, or may contain both. The aliphatic hydrocarbon ring may be saturated or unsaturated, but it is preferable that it be saturated.

[0033] The number of members in the above aliphatic hydrocarbon ring is preferably 4 to 7 members, and more preferably 5 or 6 members, when it is an aliphatic hydrocarbon ring constituting a condensed ring. When the above aliphatic hydrocarbon ring constitutes a bridged ring, the total number of carbon atoms constituting the ring structure of the bridged ring (the total number of carbon atoms constituting the ring structure of the polycyclic hydrocarbon structure consisting of the bridged ring) is preferably 5 to 10, and more preferably 6 to 10. Bicyclo rings or tricyclo rings are preferred as bridged rings. The number of members in the above aromatic hydrocarbon ring is preferably 6. Examples of polycyclic hydrocarbon structures consisting of condensed rings (without bridged rings) include aromatic condensed hydrocarbon rings such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, and tetracene, and non-aromatic condensed hydrocarbon rings such as indan and 1,2,3,4-tetrahydronaphthalene, with naphthalene, anthracene, pyrene, or 1,2,3,4-tetrahydronaphthalene being preferred. Examples of polycyclic hydrocarbon structures (without fused rings) composed of bridged rings include bicyclo[1.1.1]pentane, bicyclo[2.2.1]heptane (also known as norbornane), bicyclo[2.2.2]octane, and tricyclo[3.3.1.1] ３，７ ] Decane (also known as adamantane) is a preferred example. Examples of polycyclic hydrocarbon structures that are condensed rings having a bridging ring include condensed rings having bicyclo[2.2.1]heptane or bicyclo[2.2.2]octane, and a condensed ring of bicyclo[2.2.1]heptane or bicyclo[2.2.2]octane and at least two or more 5 or 6-membered aliphatic or aromatic hydrocarbon rings is preferred, with 9,10-dihydro-9,10-methanoanthracene, 9,10-dihydro-9,10-ethanoanthracene or tetrahydrodicyclopentadiene being more preferred.

[0034] With respect to the above polycyclic hydrocarbon structure, the amino group is not particularly limited as long as it has the structure of an aliphatic amine compound, and it may be directly bonded or bonded via an aliphatic hydrocarbon chain. As the aliphatic hydrocarbon chain, an alkylene group is preferred, an alkylene group having 1 to 4 carbon atoms is more preferred, and an alkylene group having 1 or 2 carbon atoms is even more preferred. The alkylene group may be linear or branched. Also, the above polycyclic hydrocarbon structure may or may not have a substituent other than an amino group or an aliphatic hydrocarbon group having an amino group as a substituent. The substituent that may be present is not particularly limited within the scope where the effects of the present invention are achieved, and examples thereof include an alkyl group.

[0035] Among them, as the ring constituting the above polycyclic hydrocarbon structure, it is preferable to include at least an aliphatic hydrocarbon ring. More preferably, it contains only an aliphatic hydrocarbon ring. Therefore, it is more preferable that the ring constituting the above polycyclic hydrocarbon structure does not contain an aromatic hydrocarbon ring. When the ring constituting the above polycyclic hydrocarbon structure contains an aliphatic hydrocarbon ring, the planarity of the compound is reduced, the bulkiness of the molecule is improved, and the water vapor barrier property can be further improved. Moreover, when the ring constituting the above polycyclic hydrocarbon structure contains only an aliphatic hydrocarbon ring, the intermolecular interaction can be suppressed, and an increase in the viscosity of the adhesive can also be suppressed. Also, the above polycyclic hydrocarbon structure preferably contains at least a bridging structure, more preferably contains only a bridging structure and does not contain a condensed ring structure, and from the viewpoint of more balancedly achieving hydrophobicity derived from the mobility and bulkiness of the molecular chain, further improving low-temperature curability, water vapor barrier property and heat-resistant water property, a bicyclo ring is even more preferred.

[0036] The number of rings constituting the above polycyclic hydrocarbon structure may be two or more, preferably two to four, more preferably two or three, and even more preferably two, from the viewpoint of further improving low-temperature curability while satisfying excellent water vapor barrier properties and hot water resistance due to the bulkiness of the molecule. The number of rings constituting the above polycyclic hydrocarbon structure is counted as follows, depending on the type of polycyclic hydrocarbon structure. If the above polycyclic hydrocarbon structure is composed of fused rings, it means the sum of the number of monorings constituting the fused rings. If the above polycyclic hydrocarbon structure is composed of bridged rings, the number of rings is x, depending on whether the bridged ring hydrocarbon named according to von Bayer nomenclature (IUPAC (International Union of Pure and Applied Chemistry) Recommendation 1999) is an "x-ring system". For example, the polycyclic hydrocarbon structure of the example compound B-2-9 described later is a "bicyclic system" according to von Bayer nomenclature, so x = 2, and the number of rings constituting the above polycyclic hydrocarbon structure is 2. If the above polycyclic hydrocarbon structure is a condensed ring with a bridging ring, the number of rings in the bridging ring portion (y) is determined as described above, and the sum of this number and the number of rings condensed with this bridging ring portion (z) is taken (i.e., y + z). If the ring condensed with the bridging ring portion is a condensed ring, the number of rings in the bridging ring portion is calculated using the sum of the number of monorings that make up this condensed ring. For example, the polycyclic hydrocarbon structure of example compound B-2-6 described later has a bridging ring portion that is a "bicyclic system" according to von Bayer nomenclature, so y = 2. The number of rings condensed with the above bridging ring portion (z) is 2, and the number of rings that make up the above polycyclic hydrocarbon structure is y + z = 2 + 2 = 4. Of the example aliphatic amine compounds having the polycyclic hydrocarbon structure described above, the compounds having two rings constituting the polycyclic hydrocarbon structure are B-2-1 to B-2-3, B-2-7 to B-2-10 and B-2-14, the compounds having three rings constituting the polycyclic hydrocarbon structure are B-2-4 and B-2-11 to B-2-13, and the compounds having four rings constituting the polycyclic hydrocarbon structure are B-2-5 and B-2-6.

[0037] The aliphatic amine compound having the above polycyclic hydrocarbon structure may be a salt. Examples of the salt of the aliphatic amine compound having the above polycyclic hydrocarbon structure include salts with mineral acids such as hydrochloric acid, hydrobromic acid, nitric acid, and sulfuric acid.

[0038] As the aliphatic amine compound having the above polycyclic hydrocarbon structure, from the viewpoint of further improving the water vapor barrier property and heat resistance, the above polycyclic hydrocarbon structure preferably contains at least an aliphatic hydrocarbon ring and a bridging structure, and the number of rings constituting the polycyclic hydrocarbon structure is 2 to 4, and it is preferably a monofunctional or bifunctional aliphatic amine compound. More preferably, it is a bifunctional aliphatic amine compound having a bicyclic bridging hydrocarbon structure in which the number of rings constituting the polycyclic hydrocarbon structure is 2.

[0039] The active hydrogen equivalent (equivalent of the active hydrogen possessed by the amino group) of the aliphatic amine compound having the above polycyclic hydrocarbon structure is preferably 25 to 2000, more preferably 25 to 550, still more preferably 25 to 两百, still more preferably 25 to 150, and particularly preferably 30 to 150. The active hydrogen equivalent is a value obtained by dividing the molecular weight of the aliphatic amine compound having the above polycyclic hydrocarbon structure by the number of moles of the active hydrogen of the unsubstituted amino group possessed by the aliphatic amine compound having the above polycyclic hydrocarbon structure (meaning the molecular weight per active hydrogen of the unsubstituted amino group in the aliphatic amine compound having the above polycyclic hydrocarbon structure). The molecular weight of the aliphatic amine compound having the above polycyclic hydrocarbon structure is preferably 85 to 300, more preferably 85 to 250.

[0040] Preferred specific examples of the aliphatic amine compound having the above polycyclic hydrocarbon structure are shown below. However, the aliphatic amine compound having the above polycyclic hydrocarbon structure is not limited thereto. In the following compounds, the substitution position of the amino group or the alkyl group having an amino group bonded to the polycyclic hydrocarbon structure is not limited to those shown below.

[0041]

[0042] (Other Amine Compounds) The adhesive of the present invention may contain, as component (B), an amine compound other than an aliphatic amine compound having a polycyclic hydrocarbon structure (hereinafter also referred to as "other amine compound"), within the range that achieves the effects of the present invention, for the purpose of adjusting the physical properties of the adhesive. The other amine compound may be any compound having two or more amino groups having active hydrogen in one molecule. The other amine compound may be an unsubstituted amino group (-NH ２ It is preferable that the amine compound has ), and more preferably two or more unsubstituted amino groups. For other amine compounds, it is even more preferable that all of the amino groups it has are unsubstituted amino groups. As other amine compounds, a wide range of amine compounds that exhibit curing activity in epoxy adhesives can be used. The number of amino groups having active hydrogen in one molecule of the other amine 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 can be suitably used. The active hydrogen equivalent (equivalent amount of active hydrogen in the amino groups) of the other amine compound is preferably 25 to 2000, more preferably 25 to 1000, even more preferably 30 to 900, even more preferably 30 to 800, even more preferably 30 to 700, and particularly preferably 30 to 600. The active hydrogen equivalent is the value obtained by dividing the molecular weight of the other amine compound by the number of moles of active hydrogen atoms in the amino group of the other amine compound (meaning the molecular weight per active hydrogen atom of the amino group in the other amine compound). Examples of amino groups containing active hydrogen include unsubstituted amino groups and primary amino groups.

[0043] The molecular weight of the other amine compounds is preferably 100 to 6000, and more preferably 100 to 3000. If the polyamine compound (B) is a polymer (for example, if it has a polyoxyalkylene group as described later), the above molecular weight is the number average molecular weight.

[0044] Other amine compounds are preferably in a form in which two or more amino groups are bonded via groups selected from aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and heterocyclic groups, or combinations thereof. Furthermore, other amine compounds are more preferably in a form in which two or more amino groups are bonded via aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, or combinations thereof; more preferably in a form in which they are bonded via aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, a combination of aliphatic hydrocarbon groups and alicyclic hydrocarbon groups, or a combination of aliphatic hydrocarbon groups and aromatic hydrocarbon groups; more preferably in a form in which they are bonded via aliphatic hydrocarbon groups; and even more preferably in a form in which they are bonded via aliphatic hydrocarbon groups.

[0045] The "aliphatic hydrocarbon group" may have branching, and if the "group that bonds two or more unsubstituted amino groups" is an aliphatic hydrocarbon group, it is preferable that this aliphatic hydrocarbon group has a branched structure. As for the "combination of an aliphatic hydrocarbon group and an aromatic hydrocarbon group," for example, "aliphatic hydrocarbon group - aromatic hydrocarbon group - aliphatic hydrocarbon group" is preferred. As for the "combination of an aliphatic hydrocarbon group and an alicyclic hydrocarbon group," for example, "aliphatic hydrocarbon group - alicyclic hydrocarbon group," "aliphatic hydrocarbon group - alicyclic hydrocarbon group - aliphatic hydrocarbon group," and "alicyclic hydrocarbon group - aliphatic hydrocarbon group - alicyclic hydrocarbon group." The number of carbon atoms in the aliphatic hydrocarbon group is preferably 2 to 50, and more preferably 2 to 12. The aliphatic hydrocarbon group is preferably an alkylene group, and specific examples of alkylene groups include methylene, ethylene, propylene, hexamethylene, 2,4,4-trimethylhexamethylene, and dodecamethylene. The alicyclic hydrocarbon group preferably has 4 to 50 carbon atoms, 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 cycloalkylene groups include cyclobutylene, cyclopentylene, and cyclohexylene. Aromatic hydrocarbon rings constituting the aromatic hydrocarbon group include, for example, a benzene ring and a condensed ring of two or more benzene rings, and specific examples of this condensed ring include a naphthalene ring, anthracene ring, perylene ring, fluorene ring, and acenaphthene ring. Among these aromatic hydrocarbon rings, the benzene ring is preferred.

[0046] As the other amine compounds mentioned above, specific examples of polyamine compounds (B) described in paragraph

[0044] of International Publication No. 2020 / 012993 can be preferably applied.

[0047] The aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, or combination thereof described above may have a heteroatom (preferably an oxygen atom) such as an oxygen atom, nitrogen atom, or sulfur atom between the carbon-carbon bonds. For example, a form having an oxygen atom between the carbon-carbon bonds is included. As an amine compound in which two or more amino groups are bonded by a group having an oxygen atom between the carbon-carbon bonds in such an aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, or combination thereof, the description of a polyamine compound having a polyoxyalkylene group described in paragraph

[0037] of International Publication No. 2020 / 012993 and the description of specific examples of polyamine compound (B) described in paragraphs

[0039] to

[0043] of International Publication No. 2020 / 012993 can be applied as is. It is preferable that the aliphatic hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, or combination thereof described above do not have a heteroatom (an atom other than carbon and hydrogen atoms) such as an oxygen atom, nitrogen atom, or sulfur atom between the carbon-carbon bonds.

[0048] The amine compound (aliphatic amine compounds and other amine compounds having a polycyclic hydrocarbon structure) as component (B) can be synthesized by conventional methods. Alternatively, commercially available products may be used.

[0049] The amine compound as component (B) (aliphatic amine compounds having a polycyclic hydrocarbon structure and other amine compounds) is preferably an amine compound that does not contain heteroatoms other than nitrogen atoms (atoms other than carbon and hydrogen atoms) derived from the amino group, from the viewpoint of increasing hydrophobicity and further improving resistance to hot water. The proportion of the aliphatic amine compound having a polycyclic hydrocarbon structure in 100 parts by mass of the amine compound as component (B) is not particularly limited as long as the effects of the present invention are achieved, and is preferably, for example, 40 to 100 parts by mass.

[0050] The content of the amine compound as component (B) in the adhesive of the present invention is not particularly limited and can be appropriately adjusted according to the reaction between component (A) and component (B), the amount of active hydrogen equivalent, etc.

[0051] In the adhesive I of the present invention, for example, the content of the amine compound as component (B) can be 5 to 100 parts by mass, preferably 10 to 90 parts by mass, and more preferably 20 to 90 parts by mass, with respect to 100 parts by mass of epoxy resin as component (A1). Furthermore, in the adhesive I of the present invention, the active hydrogen equivalent of the amine compound as component (B) (active hydrogen equivalent / epoxy equivalent) with respect to the total amount of epoxy equivalent of the epoxy resin as component (A1) and the epoxy equivalent of the terminal epoxy compound as component (C) is preferably 0.05 to 1.5, more preferably 0.10 to 1.2, and even more preferably 0.15 to 1.0.

[0052] In the adhesive II of the present invention, for example, the content of the amine compound as component (B) can be 3 to 100 parts by mass, preferably 5 to 70 parts by mass, and more preferably 5 to 50 parts by mass, with respect to 100 parts by mass of epoxy resin as component (A2). Furthermore, in the adhesive II of the present invention, the active hydrogen equivalent of the amine compound as component (B) (active hydrogen equivalent / epoxy equivalent) relative to the total amount of epoxy equivalent of the epoxy resin as component (A2) and the epoxy equivalent of the terminal epoxy compound as component (C), which may be contained, is preferably 0.05 to 1.5, more preferably 0.10 to 1.2, and even more preferably 0.15 to 1.0.

[0053] <Component (C)> Adhesive I of the present invention contains a terminal epoxy compound represented by the following general formula (1) as component (C), which is a plasticizer. Adhesive II of the present invention may also contain a terminal epoxy compound represented by the following general formula (1) as component (C), which is a plasticizer. The terminal epoxy compound has excellent compatibility with epoxy resin as component (A), and as described above, after curing, the epoxy group reacts with the cured product and is incorporated as a constituent component, suppressing bleed-out from the cured product and contributing to the excellent water vapor barrier and hot water resistance of the cured product. A terminal epoxy compound means a compound in which only one of the two carbon atoms constituting the epoxy ring becomes a bonding site and is bonded to a structural part other than the epoxy ring that constitutes the terminal epoxy compound.

[0054]

[0055] In the formula, n is an integer from 1 to 6. R represents an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group (preferably an aromatic heterocyclic group), or a group formed by combining these groups, with a valency of n. However, R does not adopt a -phenylene-methylene-phenylene- structure, nor a -phenylene-dimethylmethylene-phenylene- structure, nor does it have an acrylonitrile butadiene copolymer structure, nor does it have a fluorene skeleton, nor does it bond with the epoxy group in the formula to form a ring. A group with a valency of n (an n-valent group) means a group in which n different atoms have free valence.

[0056] n is an integer from 1 to 6, and from the viewpoint of adjusting the glass transition temperature of the cured adhesive to a low level while maintaining hydrophobicity, 1 or 2 is preferred, and from the viewpoint of further improving the water vapor barrier properties and hot water resistance of the cured adhesive, 2 is more preferred.

[0057] R is preferably an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group that is a combination of these groups, with a valency of n.

[0058] Aliphatic hydrocarbon groups and alicyclic hydrocarbon groups may have heteroatoms in their carbon chains. However, groups in general formula (1) that have a structure in which a heteroatom and an epoxy group are directly bonded (-heteroatom-epoxy group) are not included. Examples of heteroatoms (atoms other than carbon and hydrogen atoms) include oxygen, nitrogen, and sulfur atoms, with oxygen atoms being preferred. Note that "having heteroatoms in the carbon chain" means that a heteroatom is incorporated into the carbon chain, such as in a -C-O-C- (ether bond). Examples of terminal epoxy compounds in which R has heteroatoms in its carbon chain include compounds having terminal epoxy groups at one or both ends of a polyether chain, and those containing a polyether chain among the aliphatic polyhydric alcohol polyglycidyl ethers described in paragraphs

[0062] to "0078" of International Publication No. 2020 / 012993 can be preferably applied.

[0059] Examples of n-valent aliphatic hydrocarbon groups include n-valent aliphatic saturated hydrocarbon groups (alkyl groups, alkylene groups, alkanetriyl groups, alkanetetrayl groups, alkampentile groups, and alkanehexyl groups) and n-valent aliphatic unsaturated hydrocarbon groups (for example, alkyl groups, alkylene groups, alkanetriyl groups, alkanetetrayl groups, alkampentile groups, and alkanehexyl groups having a carbon-carbon double bond in the molecular chain; however, they do not have a cyclic structure). The aliphatic hydrocarbon groups may be linear or branched. Among these, n-valent aliphatic saturated hydrocarbon groups are preferred.

[0060] Examples of n-valent alicyclic hydrocarbon groups include cycloalkyl groups, cycloalkylene groups, cycloalkanetriyl groups, cycloalkanetetrayl groups, cycloalkampentile groups, and cycloalkanehexyl groups.

[0061] Examples of n-valent aromatic hydrocarbon groups include aryl groups, arylene groups, arenetriyl groups, arenetetrayl groups, arenepentile groups, and arenehexyl groups.

[0062] An n-valent aromatic heterocyclic group is the same as the n-valent aromatic hydrocarbon group described above, except that it has a heteroatom in the aromatic ring. The number of heteroatoms in the aromatic ring is preferably 1 or 2, and more preferably 1. Examples of heteroatoms include oxygen, nitrogen, and sulfur atoms, with oxygen being preferred.

[0063] The above-mentioned combination of n-valent groups is preferably a group formed by combining at least two groups from aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups, more preferably a group formed by combining two or three groups, and even more preferably a group formed by combining two groups. Examples include a group formed by combining an aliphatic hydrocarbon group and an alicyclic hydrocarbon group, and a group formed by combining an aliphatic hydrocarbon group and an aromatic hydrocarbon group.

[0064] From the viewpoint of further improving hydrophobicity, water vapor barrier properties, and hot water resistance, the terminal epoxy compound of component (C) preferably does not contain heteroatoms other than oxygen atoms (atoms other than carbon and hydrogen atoms) derived from the epoxy group or glycidyl ether group, and more preferably does not contain heteroatoms other than oxygen atoms (atoms other than carbon and hydrogen atoms) derived from the glycidyl ether group. Here, the glycidyl ether group refers to the group represented by the following general formula (g).

[0065]

[0066] In the above formula, L is a methylene group or an ethylene group (preferably a methylene group), and * represents a bond.

[0067] In other words, as the terminal epoxy compound of component (C), a compound represented by the following general formula (2) is preferred.

[0068]

[0069] In the above formula, R １ represents an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, or a group formed by combining these groups, with a valency of n. L represents a methylene group or an ethylene group. m is 0 or 1, and n is the same as n in the general formula (1) above. However, R １ It does not adopt a -phenylene-methylene-phenylene-structure, nor a -phenylene-dimethylmethylene-phenylene-structure, nor does it have an acrylonitrile butadiene copolymer structure, nor does it have a fluorene skeleton, nor does the aliphatic hydrocarbon group or alicyclic hydrocarbon group have heteroatoms (atoms other than carbon and hydrogen atoms) in the carbon chain, nor does it bond with the epoxy group in the formula to form a ring, nor does L bond with the epoxy group in the formula to form a ring.

[0070] R １As for the aliphatic hydrocarbon group, alicyclic hydrocarbon group, or aromatic hydrocarbon group, or a group formed by combining these groups, which can be taken as R, the above description of the aliphatic hydrocarbon group, alicyclic hydrocarbon group, or aromatic hydrocarbon group, or a group formed by combining these groups, which can be taken as R, may be applied, except as specified in general formula (2). １ The group is preferably an aliphatic hydrocarbon group or a group formed by combining two aromatic hydrocarbon groups, with an aliphatic hydrocarbon group being more preferable.

[0071] As a compound represented by general formula (2), a diglycidyl ether of an aliphatic dihydric alcohol with n=2 is preferred. Specific examples of the "aliphatic dihydric alcohol" in the diglycidyl ether of an aliphatic dihydric alcohol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, and cyclohexanedimethanol.

[0072] The aliphatic dihydric alcohol diglycidyl ethers used in the present invention can be obtained, for example, by a transesterification reaction between the above-mentioned aliphatic dihydric alcohol and an ester compound having a glycidyl group. Specific examples of aliphatic dihydric alcohol diglycidyl ethers include 1,6-hexanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, neopentyl glycol diglycidyl ether, and propylene glycol diglycidyl ether. Furthermore, for the 3-6 hydric alcohols and aliphatic 3-6 hydric alcohol diglycidyl ethers in the aliphatic 3-6 hydric alcohol diglycidyl ethers, where n = 3 to 6, among the compounds represented by general formula (2), the descriptions corresponding to the 3-6 hydric alcohols and aliphatic 3-6 hydric alcohol diglycidyl ethers in paragraphs

[0065] to

[0069] of International Publication No. 2020 / 012993 can be applied, respectively.

[0073] The following are specific examples of component (C), but component (C) is not limited to these examples.

[0074] EPICLON 725, etc. (manufactured by DIC Corporation, product name)

[0075] Ricaresin DME-100, etc. (manufactured by Shin-Nippon Rika Co., Ltd., product name)

[0076] BGE-C, SY-25L, SR-NPG, SR-16H, SR-16HL, SR-TMP, SR-PG, SR-TPG, SR-4PG, SR-2EG, SR-8EG, SR-2EGS, SR-8EGS, SR-GLG, SR-DGE, SR-SEP, etc. (Manufactured by Sakamoto Pharmaceutical Co., Ltd., all are brand names)

[0077] PG-207GS, ZX-1658GS, ZX-1542, etc. (Manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., all are product names)

[0078] Denacol EX-121, Denacol EX-141, Denacol EX-142-IM, Denacol EX-146, Denacol EX-611, Denacol EX-612, Denacol EX-614, Denacol EX-614B, Denacol EX-622, Denacol EX-512, Denacol EX-521, Denacol EX-411, Denacol EX-421, Denacol EX-301, Denacol EX-313, Denacol EX-314, Denacol EX-321, Denacol EX-211, Denacol EX-810 Denacol EX-811, Denacol EX-851, Denacol EX-821, Denacol EX-830, Denacol EX-832, Denacol EX-841, Denacol EX-861, Denacol EX-911, Denacol EX-941, Denacol EX-920, Denacol EX-921, Denacol EX-931, Denacol EX-145, Denacol EX-171, Denacol EX-701, etc. (manufactured by Nagase ChemteX, all are product names)

[0079] Epolite 40E, Epolite 100E, Epolite 200E, Epolite 400E, Epolite 70P, Epolite 200P, Epolite 400P, Epolite 1500NP, Epolite 1600, Epolite 80MF, Epolite 100MF, etc. (Manufactured by Kyoeisha Chemical Co., Ltd., all are product names)

[0080] Epiol BE-200, Epiol G-100, Epiol E-100, Epiol E-400, Epiol E-1000, Epiol P-200, Epiol NPG-100, Epiol TMP-100, Epiol OH, etc. (manufactured by Nippon Oil & Fats Co., Ltd., all are brand names)

[0081] Epogosei HD, etc. (manufactured by Yokkaichi Gosei Co., Ltd., product name)

[0082] Adeka Sizer O-130P, Adeka Sizer D-32, etc. (manufactured by Adeka Corporation, all are product names)

[0083] The molecular weight of the terminal epoxy compound is not particularly limited, but is preferably 100 or more and less than 3000, more preferably 120 or more and less than 1500, and even more preferably 140 or more and less than 1000. If the terminal epoxy compound is a mixture of compounds with different n values, or has a molecular weight distribution like an oligomer, the above molecular weight refers to the mass-average molecular weight.

[0084] The mass-average molecular weight can be measured by the following method: Using a GPC instrument HLC-8220 (trade name, manufactured by Tosoh Corporation), with tetrahydrofuran as the eluent and G3000HXL + G2000HXL columns (both trade names, manufactured by Tosoh Corporation), the measurement is performed at 23°C at a flow rate of 1 mL / min, and detection is performed using radioisotopes (RI).

[0085] The number of epoxy groups in one molecule of a terminal epoxy compound is n if the terminal epoxy compound is a single compound. If the terminal epoxy compound is a mixture of different compounds with n values, the number of epoxy groups in the terminal epoxy compound is the average number of epoxy groups calculated by the following formula. The average number of epoxy groups can be measured, for example, by NMR, GPC, or titration as described later. Average number of epoxy groups = (Molecular weight) / (Average epoxy equivalent) The epoxy equivalent of the terminal epoxy compound is not particularly limited, but is preferably 80 to 1000, and more preferably 80 to 600. Epoxy equivalent is molecular weight / number of epoxy groups in one molecule. If the terminal epoxy compound is a mixture, the epoxy equivalent is calculated by the following formula and can be measured, for example, by NMR, GPC, or titration as described in JIS K7236:2009. Average epoxy equivalent = (Molecular weight) / (Average number of epoxy groups)

[0086] The terminal epoxy compound may be a liquid or a solid. The viscosity of the terminal epoxy compound at 20°C is preferably 5 mPa·s or higher, more preferably 10 mPa·s or higher, and even more preferably 20 mPa·s or higher. There is no particular upper limit, but 1,000 mPa·s or less is practical.

[0087] In the adhesive I of the present invention, the content of the terminal epoxy compound, which is a plasticizer as component (C), is 60 to 250 parts by mass per 100 parts by mass of the epoxy resin content of component (A1). From the viewpoint of further improving water vapor barrier properties and hot water resistance, it is preferably 80 to 250 parts by mass, more preferably 80 to 210 parts by mass, and even more preferably 80 to 180 parts by mass.

[0088] When the adhesive II of the present invention contains component (C), the content of the terminal epoxy compound, which is a plasticizer, as component (C) is preferably 10 to 60 parts by mass, more preferably 15 to 55 parts by mass, even more preferably 20 to 55 parts by mass, and particularly preferably 25 to 50 parts by mass, based on 100 parts by mass of the epoxy resin content of component (A2).

[0089] In the adhesive of the present invention, component (C) may be used alone or in combination of two or more types.

[0090] <Component (D)> Adhesive I of the present invention preferably further contains the following component (D) in addition to the above components (A1), (B) and (C). Adhesive II of the present invention preferably further contains the following component (D) in addition to the above components (A2) and (B), and the above component (C) which may be contained. Component (D): At least one of a curing accelerator, an adhesion improver, and a filler. Including a curing accelerator improves the curing rate of the adhesive and improves its resistance to hot water. Including an adhesion improver improves adhesion to endoscopic components such as substrates, prevents moisture from entering the interface between the endoscopic components such as substrates and the cured adhesive, and improves its resistance to hot water. Including a filler suppresses the permeation of water vapor and improves its water vapor barrier properties. Component (D) may be used alone or in combination of two or more types.

[0091] As a curing accelerator, any compound that functions as a curing accelerator in the curing reaction between the main component (A) and the curing component (B) can be used without particular limitation. Examples include alcohol compounds, phenol compounds, tertiary amine compounds, imidazole compounds, phosphine compounds, phosphonium salt compounds, Lewis acid compounds, and carboxylic acid compounds, with alcohol compounds or phenol compounds being preferred. As alcohol compounds, 2- to 4-functional alcohol compounds are preferred. Specific examples of phenol compounds include nonylphenol, 4-tert-butylphenol, styrene-phenol (mono(or di or tri)(α-methylbenzyl)phenol, or mixtures thereof, in which styrene is added to phenol). Furthermore, phenol resins are also preferred as phenol compounds, and both novolac-type and resol-type phenol resins can be used. Using liquid phenol resin is preferred because it has excellent solubility and yields a uniform adhesive. Specific examples include Resitopp APG, Resitopp ELP83H, Resitopp ELPC75, and Resitopp ELR (all trade names, manufactured by Gun-ei Chemical Industry Co., Ltd.). Furthermore, using a solid phenolic resin is preferable because it improves the mechanical strength of the cured adhesive and results in a tougher adhesive. Specific examples include LR-402 and H-79 (both trade names, manufactured by Lignite Co., Ltd.).

[0092] As an adhesion enhancer, a material that forms a chemical bond or interaction between the adhesive and the endoscopic component such as the substrate can be used. For example, a silane coupling agent can be preferably used. Specific examples of silane coupling agents include KBE-1003, KBM-1403, KBE-503, KBM-5103, KBM-303, KBM-402, KBM-403, KBE-402, KBE-403, KBM-903, KBM-9659, and KBM-802 (all trade names, manufactured by Shin-Etsu Silicone Co., Ltd.), and VD-5 (trade name, manufactured by Shikoku Chemicals Co., Ltd.). As a silane coupling agent, a silane coupling agent containing an epoxy group can be preferably used. In the present invention, if the silane coupling agent contains an epoxy group, it is classified as an adhesion enhancer rather than component (B) as described above.

[0093] As fillers, for example, inorganic particles such as calcium carbonate, silica, talc, and mica, as well as carbon black, can be used. Specific examples of talc include Microace SG95, Microace P-3, Microace K-1, Microace MS-P, SG-200, SG-2000, Nanoace D-600, Nanoace D-1000 (all product names, manufactured by Nippon Talc Co., Ltd.), Crown Talc HS, Crown Talc 250M, and High Filler #17 (all product names, manufactured by Muramatsu Sangyo Co., Ltd.). Specific examples of silica include AEROSIL OX50, AEROSIL 200, AEROSIL R972, AEROSIL R974, AEROSIL R976, AEROSIL RX50, AEROSIL NAX50, AEROSIL RX200, AEROSIL RX300, AEROSIL R812, AEROSIL RY50, AEROSIL RY200, AEROSIL RY300, AEROSIL R504, AEROSIL R805 and AEROSIL Examples include R711 (all trade names, manufactured by Nippon Aerosil Co., Ltd.), QSG-10, QSG-30, QSG-100 (all trade names, manufactured by Shin-Etsu Silicone Co., Ltd.), and FB-5D, FB-20D, FB-40D (all trade names, manufactured by Denka Co., Ltd.). These silicas are preferably surface-treated, and the surface-modifying group is preferably a trimethylsilyl group or a dimethylpolysiloxane group (for example, a monovalent group obtained by removing one hydrogen atom from the methyl group of dimethylpolysiloxane), and more preferably a dimethylpolysiloxane group.

[0094] - Substituent Group T - In the present invention, preferred substituents include substituents selected from the following substituent group T. In the present invention, if a substituent is described only as such, the description of the corresponding substituent in this substituent group T can be referred to and applied. For example, if only "alkyl group" is described, the description of "alkyl group" in this substituent group T can be referred to and applied. The same applies to substituents other than "alkyl group". Furthermore, in the present invention, substituents that a substituent such as an "alkyl group" may have include substituents selected from the following substituent group T. Furthermore, if a substituent such as an "alkyl group" has substituents and further substituents, substituents that a substituent may have include substituents formed by combining two or more substituents selected from the following substituent group T. Furthermore, in this specification, when alkyl groups are described separately from cyclic (cyclo) alkyl groups, alkyl groups are used to encompass linear alkyl groups and branched alkyl groups. On the other hand, when alkyl groups are not described separately from cyclic alkyl groups, and unless otherwise specified, alkyl groups are used to encompass linear alkyl groups, branched alkyl groups, and cycloalkyl groups. This also applies to groups that can form a cyclic structure (alkyl groups, alkenyl groups, alkynyl groups, etc.) and groups that can form a cyclic structure (alkoxy groups, alkylthio groups, alkenyloxy groups, etc.), as well as compounds that contain groups that can form 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, and preferably 5 or more, regardless of the lower limit of the number of atoms specifically described below for groups that can form this structure. In the description of the substituent group T below, groups with linear or branched structures and groups with cyclic structures are sometimes described separately to clarify them, for example, alkyl groups and cycloalkyl groups.

[0095] The substituent group T includes the following groups: alkyl groups (preferably 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, even more preferably 1 to 12 carbon atoms, even more preferably 1 to 8 carbon atoms, even more preferably 1 to 6 carbon atoms, particularly preferably 1 to 3 carbon atoms), alkenyl groups (preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, even more preferably 2 to 12 carbon atoms, even more preferably 2 to 6 carbon atoms, even more preferably 2 to 4 carbon atoms), alkynyl groups (preferably 2 to 30 carbon atoms, more preferably 2 to 20 carbon atoms, even more preferably C2-C12, more preferably C2-C6, even more preferably C2-C4), cycloalkyl group (preferably C3-C20), cycloalkenyl group (preferably C5-C20), aryl group (may be a monocyclic group or a fused ring group (preferably a fused ring group of 2-6 rings). If it is a fused ring group, it consists of a 5-7 membered ring, etc. The aryl group preferably has C6-C40, more preferably C6-C30, even more preferably C6-C26, particularly preferably C6-C10), A heterocyclic group (having at least one nitrogen, oxygen, sulfur, phosphorus, silicon, or selenium atom as a ring constituent atom, and may be a monocyclic group or a fused ring group (preferably a fused ring group of 2 to 6 rings). If it is a monocyclic group, the number of ring members is preferably 5 to 7, more preferably 5 or 6. The number of carbon atoms in a 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). ), alkoxy group (preferably C1-C20, more preferably C1-C12), alkenyloxy group (preferably C2-C20, more preferably C2-C12), alkynyloxy group (preferably C2-C20, more preferably C2-C12), cycloalkyloxy group (preferably C3-C20), aryloxy group (preferably C6-C40, more preferably C6-C26, even more preferably C6-C14), heterocyclic oxy group (preferably C2-C20),

[0096] Alkoxycarbonyl group (preferably 2 to 20 carbon atoms), cycloalkoxycarbonyl group (preferably 4 to 20 carbon atoms), aryloxycarbonyl group (preferably 6 to 20 carbon atoms), amino group (preferably 0 to 20 carbon atoms, unsubstituted amino group (-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-)heterocyclicamino group. Each of the above groups substituting an unsubstituted amino group is synonymous with the corresponding group in substituent group T.), sulfamoyl group (preferably C0 to C20, alkyl, cycloalkyl or aryl sulfamoyl group), acyl group (preferably C1 to C20, more preferably C2 to C15), acyloxy group (preferably C1 to C20), carbamoyl group (preferably C1 to C20, alkyl, cycloalkyl or aryl carbamoyl group),

[0097] Acylamino group (preferably 1 to 20 carbon atoms), sulfonamide group (preferably 0 to 20 carbon atoms, preferably alkyl, cycloalkyl, or aryl sulfonamide group), alkylthio group (preferably 1 to 20 carbon atoms, more preferably 1 to 12 carbon atoms), cycloalkylthio group (preferably 3 to 20 carbon atoms), arylthio group (preferably 6 to 40 carbon atoms, more preferably 6 to 26 carbon atoms, even more preferably 6 to 14 carbon atoms), heterocyclic thio group (preferably 2 to 20 carbon atoms), alkyl, cycloalkyl, or arylsulfonyl group (preferably 1 to 20 carbon atoms),

[0098] A silyl group (preferably having 1 to 30 carbon atoms, more preferably 1 to 20 carbon atoms, and preferably a silyl group substituted with alkyl, aryl, alkoxy or aryloxy), a silyloxy group (preferably having 1 to 20 carbon atoms, and preferably a silyloxy group substituted with alkyl, aryl, alkoxy or aryloxy), a hydroxy group, a cyano group, a nitro group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom or an iodine atom), an oxygen atom (specifically, >CH that constitutes a ring ２ is replaced by >C=O), a carboxy group (-CO ２ H), a phosphono group [-PO(OH) ２ , a phosphoryl group [-O-PO(OH) ２ , a sulfo group (-SO ３ H), a boronic acid group [-B(OH) ２ , an onium group (including an ammonium group containing a cyclic ammonium, a sulfonio group, a phosphonio group, preferably having 0 to 30 carbon atoms, more preferably 1 to 20), a sulfanyl group (-SH), an amino acid residue, or a polyamino acid residue. Further, the above alkyl group, alkenyl group, alkynyl group, cycloalkyl group, cycloalkenyl group, aryl group, heterocyclic group, alkoxy group, alkenyloxy group, alkynyloxy group, cycloalkyloxy group, aryloxy group, heterocyclic oxy group, alkoxycarbonyl group, cycloalkoxycarbonyl group, aryloxycarbonyl group, amino group, sulfamoyl group, acyl group, acyloxy group, carbamoyl group, acylamino group, sulfonamide group, alkylthio group, cycloalkylthio group, arylthio group, heterocyclic thio group, alkyl, cycloalkyl or arylsulfonyl group having a carboxy group, a phosphono group, a sulfo group, an onium group, an amino acid residue, or a polyamino acid residue as a substituent is mentioned.

[0099] The substituents selected from the substituent group T are more preferably alkyl groups, alkenyl groups, cycloalkyl groups, aryl groups, heterocyclic groups, alkoxy groups, cycloalkoxy groups, aryloxy groups, alkoxycarbonyl groups, cycloalkoxycarbonyl groups, amino groups, acylamino groups, cyano groups, or halogen atoms, and are particularly preferably alkyl groups, alkenyl groups, aryl groups, heterocyclic groups, alkoxy groups, alkoxycarbonyl groups, amino groups, acylamino groups, or cyano groups.

[0100] Unless otherwise specified, substituents selected from substituent group T include groups formed by combining multiple of the above groups. For example, when a compound or substituent contains alkyl groups, alkenyl groups, etc., these may be substituted or unsubstituted. Also, when it contains aryl groups, heterocyclic groups, etc., these may be monocyclic or fused rings, and may be substituted or unsubstituted.

[0101] The adhesive of the present invention preferably has a glass transition temperature (Tg) of 40 to 80°C for the cured product obtained by curing the adhesive of the present invention to 100% curing rate. Generally, the glass transition temperature of a cured product obtained by curing an adhesive containing epoxy resin and a conventional amine-based curing agent to 100% curing rate is 100°C or higher, but with the adhesive of the present invention, it can be in the range of 40 to 80°C. If the glass transition temperature of the cured product to 100% curing rate is 40°C or higher, it can exhibit excellent water vapor barrier properties and excellent hot water resistance. Moreover, if it is 80°C or lower, the mobility of the molecular chains during curing is sufficiently ensured, and the curing reaction proceeds effectively with an excellent curing rate (approximately 95% or higher) even in the low temperature range (for example, 23 to 60°C, preferably 23 to 50°C), and a cured product can be obtained. "Glass transition temperature (Tg) of a cured product to 100% curing rate" is the glass transition temperature measured for the cured product obtained after preparing a cured product to which the adhesive has a 100% curing rate. Specifically, as described in the examples below, it is obtained by measuring the glass transition temperature of the cured product obtained by curing the adhesive under curing conditions (temperature and time) that result in a 100% curing rate. The curing rate of the adhesive and the glass transition temperature are also measured based on the methods described in the examples below.

[0102] The adhesive of the present invention preferably has a water absorption rate (also simply referred to as "water absorption rate") of less than 5.0% by mass when a cured product of the adhesive of the present invention, cured to 100% curing rate, is immersed in 60°C water for 24 hours. Generally, the glass transition temperature of a cured product obtained by curing an adhesive containing epoxy resin and a conventional amine-based curing agent at 100% curing rate is 5.0% by mass or higher, but in the case of the adhesive of the present invention, it can be less than 5.0% by mass. When the above water absorption rate of a cured product at 100% curing rate is less than 5.0% by mass, it can exhibit excellent water vapor barrier properties and excellent hot water resistance. "Water absorption rate of a cured product cured to 100% curing rate" is the water absorption rate measured on the cured product obtained after preparing a cured product with a 100% curing rate of the adhesive. Specifically, as described in the examples below, it is obtained by measuring the water absorption rate when a cured product obtained by curing the adhesive under curing conditions (temperature and time) that result in a 100% curing rate is immersed in 60°C water for 24 hours. The curing rate of the adhesive is also measured based on the method described in the examples below.

[0103] [Cured Product] The cured product of the present invention is a cured product produced by curing the adhesive of the present invention. As described above, the glass transition temperature (Tg) of the cured product with a curing rate of 100% is preferably 40 to 80°C. "Glass transition temperature (Tg) of the cured product with a curing rate of 100%" means the glass transition temperature (Tg) measured for the cured product obtained under conditions where the curing rate of the cured product is 100%, such as by raising the temperature if the curing rate of the cured product is not 100%. When measuring the glass transition temperature of the cured product itself, a curing rate of 100% of the cured product means that the heat generated by the cured product itself is 0 J, as described in the calculation formula in the examples below. The curing rate and glass transition temperature of the adhesive are measured based on the method described in the examples below.

[0104] In other words, 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. Mixing of each component is preferably carried out while removing air bubbles, and therefore is usually done under reduced pressure. From the viewpoint of avoiding the endoscope or endoscope component being exposed to high temperatures many times during the manufacturing process, it is preferable to keep the curing temperature as low as possible. For example, the curing temperature is preferably 100°C or lower, more preferably 80°C or lower, even more preferably 60°C or lower, and can also be 50°C or lower. In addition, in order to allow the curing reaction to proceed sufficiently, the curing temperature is preferably 0°C or higher, and more preferably 10°C or higher. A 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 according to the curing temperature so as to obtain a sufficient curing rate (approximately 95% or more), and is usually 1.5 to 200 hours to obtain the cured product.

[0105] [Endoscope Components] In the endoscopic components of the present invention, the constituent materials of the endoscope are fixed by the cured product of the present invention. "The constituent materials are fixed by the cured product of the present invention" means that at least some of the constituent materials constituting the endoscope are fixed to the support member via the cured product of the present invention. Examples of constituent materials of the endoscope include at least one of resin materials, glass materials, and metal materials such as stainless steel, and components made from these constituent materials are fixed to the support member via the cured product of the present invention. The endoscopic components of the present invention constitute the endoscope by being incorporated as part of the constituent materials of the endoscope of the present invention.

[0106] [Endoscope] The endoscope of the present invention includes the endoscopic component of the present invention as a component. That is, the endoscope of the present invention includes a component in which the constituent material of the endoscope is fixed by the cured product of the present invention. In addition to the form in which the endoscopic component of the present invention is prepared in advance and fixed with other components, the endoscope of the present invention also includes a form in which, during the process of manufacturing the endoscope of the present invention, the constituent material of the endoscope is fixed by the cured product of the present invention, and the endoscopic component is incorporated as a component of the endoscope of the present invention.

[0107] An example of the endoscope (electronic endoscope) of the present invention will be described. The electronic endoscope incorporates a flexible tube for endoscopy (hereinafter, the flexible tube for endoscopy may also be simply referred to as the "flexible tube") and is widely used as a medical device. In the example shown in Figure 1, the electronic endoscope 2 comprises an insertion section 3 inserted into a body cavity, a main unit operation section 5 connected to the base end of the insertion section 3, and a universal cord 6 connected to a processor device and a light source device. The insertion section 3 consists of a flexible tube 3a connected to the main unit operation section 5, an angle section 3b connected thereto, and a tip section 3c connected to its tip and mainly made of a metal (for example, stainless steel) material. An imaging device (not shown) for intra-body cavity imaging is built into this tip section 3c. The flexible tube 3a, which occupies most of the length of the insertion section 3, is flexible along almost its entire length, and the part inserted into the body cavity or the like has a particularly flexible structure. In Figure 1, multiple channels (tubes, not shown) are formed on the tip surface of the tip portion 3c, extending from the main body operating section 5 in the axial direction of the insertion portion 3.

[0108] As shown in Figure 2, the flexible tube 3a in Figure 1 has a structure in which a resin layer 15 is covered on the outer surface of a flexible tube base material 14. 14a is the tip side (tip portion 3c side), and 14b is the base side (main body operating portion 5 side). The flexible tube base material 14 is formed by covering a spiral tube 11, which is formed by spirally winding a metal strip 11a on the innermost part, with a cylindrical mesh body 12 made of braided metal wire. A nozzle 13 is fitted to both ends. This resin layer 15 is bonded to the flexible tube base material 14 via an adhesive cured material layer (adhesive portion) 17. This adhesive cured material layer 17 can be formed by applying the adhesive of the present invention and curing it. For the convenience of illustration, the adhesive cured material layer 17 is shown as a layer with a uniform thickness, but it does not necessarily have to be in that form, and may be interposed between the resin layer 15 and the flexible tube base material 14 in an irregular shape. Rather, the thickness may be almost negligible, and the resin layer 15 and the flexible tube base material 14 may be bonded in a substantially contacting manner. The outer surface of the resin layer 15 is coated with a coating layer 16 containing a chemical-resistant substance such as fluorine. Note that the adhesive cured layer 17, the resin layer 15, and the coating layer 16 are depicted as thicker than the wall thickness of the flexible tube base material 14 in order to clearly illustrate the layer structure.

[0109] As shown in Figure 3, the tip surface of the tip portion 3c has an illumination window 31, an observation window 32, and a forceps channel 33. In addition, a nozzle 34 is provided to supply water and air for cleaning the tip surface as needed. The illumination window 31, observation window 32, forceps channel 33, and nozzle 34 are connected to the main body operation unit 5 by channels.

[0110] As shown in Figure 4, the tip portion 3c is composed of a tip body 35 made of metal and a tip cap 36 made of an electrically insulating material.

[0111] 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 consisting of lenses L1 to L5 is fixed within a lens holder 37 by adhesive cured materials 41 and 42. These adhesive cured materials 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 layer. A prism 38 is bonded and fixed to the end face of the lens holder 37. This prism 38 bends the optical axis of the objective optical system at a right angle. 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 applied to these fixings. In the description of the endoscope in Figures 1 to 4 above, the adhesive of the present invention may be applied to obtain at least one of the adhesive cured material layer 17, adhesive cured materials 41 and 42 as described above, or it may be applied to fixing members not described using adhesive cured materials, such as fixing the solid-state image sensor 40 to the substrate 39.

[0112] <Endoscope Components and Endoscope Manufacturing Method> The manufacturing method for the endoscope components of the present invention is not particularly limited as long as it includes fixing the constituent materials of the endoscope using the adhesive of the present invention, and the endoscope components of the present invention can be manufactured by employing a normal manufacturing process for steps other than fixing the constituent materials. The manufacturing method for the endoscope of the present invention is not particularly limited as long as it includes constituent materials of the endoscope that are fixed using the adhesive of the present invention, and the endoscope of the present invention can be manufactured by employing a normal manufacturing process. For example, examples include a form in which the endoscope components of the present invention are prepared in advance and fixed with other constituent materials, and a form in which the constituent materials of the endoscope are fixed using the adhesive of the present invention during the process of manufacturing the endoscope of the present invention, and the endoscope components are incorporated as constituent materials of the endoscope of the present invention. In the form in which the endoscope components of the present invention are prepared in advance and fixed with other constituent materials, there are no particular restrictions on fixing the endoscope components of the present invention with the other constituent materials, but it is preferable to fix them using the adhesive of the present invention. In fixing constituent materials or endoscope components using the adhesive of the present invention, for example, the components contained in the adhesive of the present invention are preferably mixed under reduced pressure, and then the mixture is injected or applied to the application site and heated at -10 to 60°C (preferably 0 to 60°C, more preferably 10 to 50°C) for 1.5 to 200 hours to fix them to support members or the like that make up the endoscope.

[0113] The adhesive fixation of the present invention is performed in an endoscope or endoscope component by bonding a component containing at least one of the following materials—resin, metal such as stainless steel, and glass—to a support member (such as a resin component, a glass component, and a metal component). The adhesive of the present invention is preferably used for fixing resin materials to metal materials, fixing metal materials to resin materials, fixing metal materials to other metal materials, and fixing glass materials to metal materials. The following describes specific examples of how the adhesive is used in the manufacturing method of the endoscope of the present invention, but the present invention is not limited to these examples.

[0114] Among the components of an endoscope fixed by the adhesive of the present invention, a resin component is, for example, a tube inserted into the insertion section of the endoscope. Examples of resin materials constituting 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 a metal or glass component constituting the insertion section of an endoscope to the tube (to fix the metal or glass component to the tube). It can also be used to form the adhesive cured layer 17 shown in Figure 2, as described above. It can also be used to bond the resin layer 15 and the coating layer 16 shown in Figure 2.

[0115] The adhesive of the present invention can be used for finishing and fixing the outer surface of the end of a flexible outer sheath tube (resin layer 15) (the end on the tip 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 fixed to the inner member, and then the adhesive is applied to cover the thread and allowed to harden. By making the outermost layer of the tip end of the flexible tube 3a with the adhesive of the present invention, the thread at this tip end is made less likely to fray, and the insertion portion is made easier to insert into the body cavity. Furthermore, the adhesive of the present invention can be used for at least one of the bonding of the tip portion 3c and the angle portion 3b and the bonding of the insertion portion 3 and the main operating portion 5. For example, the tip portion 3c and the angle portion 3b are bonded using the adhesive of the present invention, and then the bonded portion of the tip portion 3c and the angle portion 3b and its vicinity are wrapped with thread to reinforce the bond, and the adhesive is applied to cover the thread and allowed to harden. The same applies to the bonding of the insertion portion 3 and the main operating portion 5. Furthermore, the adhesive of the present invention can also be used to fix various tubes inserted into the insertion section of an endoscope to at least one of the tip portion 3c and the main operating section 5.

[0116] Furthermore, the adhesive of the present invention is also preferably used to seal the illumination window 31 and the observation window 32 (to fix the glass members) at the tip portion 3c. By applying a thick layer of adhesive, the corners of the outer circumference of the lens can be smoothed, and the incidence of light from the side of the lens can be blocked. In addition, the adhesive of the present invention can be used to fix members such as assembling the imaging device built into the tip portion 3c, bonding parts, and sealing the solid-state image sensor 40. The imaging device has an optical system consisting of a plurality of optical components such as lenses L1 to L5 and prism 38, and a solid-state image sensor 40 such as a CCD (Charge Coupled Device) that photoelectrically converts the optical image formed by this optical system into an imaging signal. The adhesive of the present invention can be used to bond optical components such as lenses L1 to L5 and prism 38, which are made of materials such as glass, to each other, and to bond lenses L1 to L5, prism 38, etc. to a substrate 39 made of resin or metal, and by this bonding, glass members and metal members can be fixed. Furthermore, the adhesive of the present invention can be used for bonding, fixing, and sealing the solid-state image sensor 40 and the substrate 39. This bonding allows for the fixing of metal components constituting the solid-state image sensor, substrate, etc.

[0117] The present invention will be described in more detail based on the examples below, but the present invention is not to be interpreted as being limited to the following examples. The amount of each component refers to the amount of the component itself. That is, if the raw material contains a solvent, it refers to the amount excluding the solvent.

[0118] [Preparation Example] The adhesive was prepared by mixing 100 parts by mass of component (A) bisphenol A diglycidyl ether (trade name: jER828, manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 190), 20 parts by mass of component (B) trimethylhexamethylenediamine (product number T0600, manufactured by Tokyo Chemical Industry Co., Ltd., active hydrogen equivalent 39.6), 39 parts by mass of 1-naphthylmethylamine (product number N1042, manufactured by Tokyo Chemical Industry Co., Ltd., active hydrogen equivalent 78.6), and 100 parts by mass of component (C) 1,2-epoxytetradecane (product number E0314, manufactured by Tokyo Chemical Industry Co., Ltd., terminal epoxy compound). This mixture was degassed for 5 minutes at 25°C and under reduced pressure of 1.0 Pa while stirring at 2000 rpm using "Awatori Rentaro ARV-310 (trade name, manufactured by Thinky Co., Ltd.)" and No. I obtained 101 units of adhesive.

[0119] [Measurement 1: Measurement of Glass Transition Temperature (Tg)] The adhesive was cured at 120°C for 12 hours (100% curing conditions) to prepare strip-shaped test specimens of the cured adhesive sheet with a thickness of 0.5 mm, a width of 5 mm, and a length of 50 mm. The loss tangent of the prepared test specimens was measured using a dynamic viscoelasticity measuring device (Vibron: DVA-225 (product name), manufactured by IT Measurement Control Co., Ltd.) under the conditions of a gripping distance of 20 mm, a heating rate of 2°C / min, a measurement temperature range of -150°C to 250°C, and a frequency of 5 Hz. The temperature at which the obtained loss tangent showed its maximum value was defined as the glass transition temperature (Tg).

[0120] [Measurement 2: Measurement of Curing Rate] The heat generated from approximately 2 mg of adhesive immediately after mixing was measured using a high-sensitivity differential scanning calorimeter DSC7000X (Hitachi High-Tech Science Corporation). Specifically, the temperature was increased from 25°C at a heating rate of 5°C / min, and the area value of the peak originating from the curing of the epoxy adhesive, with peak temperatures between 80°C and 140°C, was determined and defined as the "heat generated immediately after mixing." Subsequently, the same measurement was performed on the cured adhesive product after curing, and this was defined as the "heat generated from the cured sample." Using the measured heat generated, the curing rate was calculated using the following formula. The curing rate was calculated for the adhesive product after curing at 120°C for 12 hours, and for the adhesive product after curing at 23°C for 72 hours. Curing Rate (%) = {("Heat generated immediately after mixing" - "Heat generated from the cured sample") / "Heat generated immediately after mixing"} × 100

[0121] [Measurement 3: Measurement of Water Absorption Rate] The adhesive was cured at 120°C for 12 hours (100% curing conditions) to prepare an adhesive cured sheet test specimen with a thickness of 0.5 mm, a width of 30 mm, and a length of 50 mm. The mass (mass before immersion) of the prepared test specimen was measured. Next, the prepared adhesive test specimen was immersed in 60°C water for 24 hours, and after wiping off the water droplets adhering to the surface of the test specimen, the mass (mass before immersion) was measured again. Using the measured mass, the water absorption rate was calculated based on the following formula: Water absorption rate (%) = {(mass after immersion - mass before immersion) / mass before immersion} × 100%

[0122] [Evaluation 1: Water vapor barrier properties] A 50 mm long, 15 mm diameter (inner diameter) SUS (Steel Use Stainless) pipe 50 was welded and sealed at one end. A 13 mm diameter, 3 mm thick glass lens 51 was fitted into the pipe after adhesive was applied around the glass lens, and the pipe was cured at 23°C for 72 hours to seal it. A test sample 53, shown in Figure 5 as a schematic longitudinal cross-section, was prepared. The obtained test sample 53 was exposed to an environment of 60°C and 90% relative humidity for 1200 hours, and then moved to an environment of room temperature (23°C) and 50% relative humidity. After moving to the environment of room temperature (23°C) and 50% relative humidity, the time until condensation began to form in the center of the glass lens, that is, the time until condensation began to form on the inside of the glass lens, was observed and the water vapor barrier properties were evaluated according to the following criteria. This test is an accelerated test that simulates the conditions under which the sample is exposed to a humid heat environment by light irradiation and water washing of a flexible tube during endoscopic procedures in the intestines. - Evaluation Criteria - SS: No clouding occurred even after 1200 hours. S: Clouding occurred between 1000 hours and less than 1200 hours. A: Clouding occurred between 800 hours and less than 1000 hours. B: Clouding occurred between 600 hours and less than 800 hours. C: Clouding occurred between 500 hours and less than 600 hours. D: Clouding occurred in less than 500 hours.

[0123] [Evaluation 2: Hot Water Resistance] A bonding test specimen 62, schematically shown in Figure 6, was prepared. Specifically, two rectangular stainless steel (SUS304) plates (60A, 60B) with a thickness of 1 mm, a width of 5 mm, and a length of 50 mm were prepared. Adhesive 61 was applied to one end of one stainless steel plate 60A in a square with sides of 5 mm, and one end of the other stainless steel plate 60B was used to cover the adhesive 61. The other SUS plate 60B was then placed on top of the stainless steel plate 60B, aligned along its long axis, and left to stand with the bonding surface fixed. The bond was then cured at 23°C for 72 hours to prepare the bonding test specimen 62. When viewed in the thickness direction, this bonding test specimen is a rectangle with a width of 5 mm and a length of 95 mm. The prepared bonding test specimen was immersed in 60°C hot water for 500 hours. Using a tensile testing machine (Autograph AGX (product name), manufactured by Shimadzu Corporation), a tensile shear test was performed on the adhesive test specimen by applying a force that shifts the adhesive surface in the lateral direction (long axis direction), and the tensile shear strength (TQ) before immersion was determined. ｂ ) and the tensile shear strength (TQ) after immersion. ａ Each was measured. The tensile shear conditions were a room temperature of 25°C and a tensile speed of 2 mm / min. The retention rate of the tensile shear strength after immersion (TQ) was measured using the tensile shear strength before immersion as the reference. ａ / TQ ｂ The resistance to hot water was evaluated by applying the following criteria to the material's temperature (x 100%). For tensile shear tests, unless otherwise specified, the description in JIS (Japanese Industrial Standards) K 6850 (1999) may be used. This test is an accelerated test that simulates disinfection by immersing an endoscope in heated disinfectant water. — Evaluation Criteria — SS: 95% or higher S: 90% or higher but less than 95% A: 85% or higher but less than 90% B: 70% or higher but less than 85% C: 50% or higher but less than 70% D: Less than 50%

[0124] The adhesive No. 101 described above, and the adhesive No. 101 described above, with the formulation of components (A) to (D) changed to those described in Tables 1-1 to 1-5 below (hereinafter collectively referred to as "Table 1"), are shown in Table 1 below as Nos. 101 to 135 and c11 to c20. In Table 1 below, Nos. 101 to 135 are the endoscopic adhesives of the present invention, and Nos. c11 to c20 are endoscopic adhesives for comparison.

[0125]

[0126]

[0127]

[0128]

[0129]

[0130] The amount of each component (A) to (D) should be indicated in the respective columns. The unit of the amount is parts by mass. A blank column means that the component is not contained. In the table above, the amounts of components (A) to (C) have been adjusted so that the equivalent ratio of the total epoxy groups of components (A) and (C) to the active hydrogen atoms of the amino groups of component (B) is approximately the same in all examples and comparative examples. Type of component (A): A-I indicates that it contains component (A-1), A-II indicates that it contains the NBR-modified epoxy compound in component (A-2), and A-III indicates that it contains the fluorene-type epoxy compound in component (A-2). Percentage of NBR-modified epoxy compound in component (A2): The unit is mass%. Mass ratio of A / C: The parts by mass of component (C) are indicated to the right of the " / ", and the parts by mass of component (A) are indicated to the left of the " / ". In the column for curing rate after curing at 120°C for 12 hours, enter the curing rate of the cured product after curing at 120°C for 12 hours. In the column for curing rate after curing at 23°C for 72 hours, enter the curing rate of the cured product after curing at 23°C for 72 hours. Details are as described above, and the unit is %. In the column for Tg after curing at 120°C for 12 hours, enter the glass transition temperature (Tg) of the cured product after curing at 120°C for 12 hours, i.e., the cured product with a curing rate of 100%. Details are as described above, and the unit is °C. In the column for water absorption rate, enter the water absorption rate when the cured product after curing at 120°C for 12 hours, i.e., the cured product with a curing rate of 100%, is immersed in 60°C water for 24 hours. Details are as described above, and the unit is %.

[0131] [Component (A): Epoxy resin] (A-I): Component (A-1) A-1: ​​Bisphenol A diglycidyl ether (Trade name: jER828, manufactured by Mitsubishi Chemical Corporation) A-2: Bisphenol F diglycidyl ether (Trade name: EPICLON830, manufactured by DIC Corporation) A-3: Epoxy novolac resin (Product number 406775, manufactured by Sigma-Aldrich Corporation) (A-II): Mixture containing the NBR-modified epoxy compound in component (A-2) A-4: Mixture of NBR-modified epoxy compound and bisphenol A diglycidyl ether (Trade name: Adekarezin EPR-4030, manufactured by ADEKA Corporation) A-5: Mixture of NBR-modified epoxy compound and bisphenol A diglycidyl ether (Trade name: Adekarezin EPR-2000, manufactured by ADEKA Corporation) (A-III): Fluorene-type epoxy compound in component (A-2) A-6: Fluorene-type epoxy compound (Trade name: Ogusol EG-200, manufactured by Osaka Gas Chemical Co., Ltd.) A-7: Fluorene-type epoxy compound (Trade name: Ogusol EG-280, manufactured by Osaka Gas Chemical Co., Ltd.)

[0132] [Component (B): Amine compounds that are curing components of epoxy resins] (B-1) Other amine compounds B-1-1: Trimethylhexamethylenediamine (product number T0600, manufactured by Tokyo Chemical Industry Co., Ltd., mixture of 2,2,4-substituted and 2,4,4-substituted) B-1-2: 1,3-bis(aminomethyl)cyclohexane (product number B1005, manufactured by Tokyo Chemical Industry Co., Ltd., mixture of cis and trans isomers) (B-2) Aliphatic amine compounds having a polycyclic hydrocarbon structure B-2-1: 1-Naphthylmethylamine (product number N1042, manufactured by Tokyo Chemical Industry Co., Ltd.) B-2-5: 1-Pyrenemethylamine hydrochloride (product number 401633, manufactured by Sigma-Aldrich) B-2-6: (11R,12R)-9,10-dihydro-9,10-ethanoanthracene-11,12-diamine (product number 778885, manufactured by Sigma-Aldrich) B-2-9: Bis(aminomethyl)norbornane (product number B3852, manufactured by Tokyo Chemical Industry Co., Ltd., mixture of positional isomers of the aminomethyl group) B-2-13: 1-adamantanemethylamine (product number A0721, manufactured by Tokyo Chemical Industry Co., Ltd.)

[0133] [Component (C): Terminal epoxy compounds as plasticizers] C-1: 1,2-Epoxytetradecane (Product No. E0314, manufactured by Tokyo Chemical Industry Co., Ltd.) C-2: 1,6-Hexanediol diglycidyl ether (Product name: Epogosei HD, manufactured by Yokkaichi Synthetic Co., Ltd.) C-3: 2-Phenylphenol glycidyl ether (Product name: Denacol EX-142-IM, manufactured by Nagase ChemteX Corporation) C-4: Polypropylene glycol diglycidyl ether (Product name: Denacol EX-920, manufactured by Nagase ChemteX Corporation) C-5: Glycidyl hexadecyl ether (Product No. 473642, manufactured by Sigma-Aldrich)

[0134] [Ingredients (D): Other additives] D-1: Resitopp ELP83H (product name, curing accelerator, manufactured by Gun-ei Chemical Industry Co., Ltd., phenolic resin) D-2: 3-Glycidyloxypropyltrimethoxysilane (adhesion improver, product number G0210, manufactured by Tokyo Chemical Industry Co., Ltd.) D-3: AEROSIL RX200 (product name, filler, manufactured by Nippon Aerosil Co., Ltd.)

[0135] The following can be seen from Table 1. Adhesives No. c11 to c14 do not satisfy conditions I and II, as component (B) is an aliphatic amine compound that does not have a polycyclic hydrocarbon structure, and are therefore not adhesives of the present invention. Of these adhesives, adhesive No. c11 has poor water vapor barrier properties, and adhesives No. c12 to c14 have poor water vapor barrier properties and hot water resistance. Note that in adhesives No. c11 and c12, the content of plasticizer (C) is 100 parts by mass per 100 parts by mass of epoxy resin (A), while in adhesive No. c12, the content of plasticizer (C) is 50 parts by mass per 100 parts by mass of epoxy resin (A), For adhesives c13 and c14, the curing rate of the cured products obtained under low-temperature curing conditions of 23°C for 72 hours was increased from 88% to 98% (No. c13 to No. c11) and from 85% to 95% (No. c14 to No. c12), respectively. Despite increasing the content ratio of component (C) to component (A) and thus improving the curing rate of the cured products obtained under low-temperature curing conditions, adhesive No. c11 still exhibits poor water vapor barrier properties, and adhesive No. c12 exhibits poor water vapor barrier properties and poor hot water resistance. Furthermore, adhesive No. c15, although containing an aliphatic amine compound with a polycyclic hydrocarbon structure in component (B), does not satisfy condition I because it does not contain a plasticizer in component (C), and does not satisfy condition II because it does not contain an epoxy resin in component (A2), and therefore is not the adhesive of the present invention. Adhesive c16 is not the adhesive of the present invention because, although component (B) contains an aliphatic amine compound having a polycyclic hydrocarbon structure, the plasticizer content of component (C) is less than 60 parts by mass per 100 parts by mass of epoxy resin content of component (A1), and it does not satisfy condition II because it does not contain epoxy resin of component (A2). In these adhesives No. c15 and c16, the curing rates of the cured products obtained under low-temperature curing conditions of 23°C for 72 hours are low, at 70% and 80%, respectively, and they have poor water vapor barrier properties and hot water resistance.Furthermore, although adhesive No. c17 contains an aliphatic amine compound having a polycyclic hydrocarbon structure as component (B), it does not satisfy condition I because the content of the plasticizer in component (C) exceeds 250 parts by mass relative to the epoxy resin content of component (A1) per 100 parts by mass, and it does not satisfy condition II because it does not contain epoxy resin as component (A2), and therefore it is not the adhesive of the present invention. Unlike adhesives No. c15 and c16, adhesive No. c17 has a high curing rate of 99% for the cured product obtained under low-temperature curing conditions of 23°C for 72 hours, but the glass transition temperature of the cured product with a 100% curing rate is 38°C, and because of the high mobility of the molecular chains, it cannot suppress the permeation of water vapor and has poor water vapor barrier properties. Furthermore, adhesives No. c18 to c20 do not satisfy either condition I or II because component (B) is an aliphatic amine compound that does not have a polycyclic hydrocarbon structure, and therefore they are not the adhesives of the present invention. Among these adhesives, No. Adhesive c18 has poor water vapor barrier properties, adhesive c19 has poor hot water resistance, and adhesive c20 has poor water vapor barrier properties and hot water resistance. In contrast, adhesives c101 to c135, which are the adhesives of the present invention, produce cured products that have excellent water vapor barrier properties and excellent hot water resistance under high temperature and high humidity conditions when cured at low temperature conditions of 23°C for 72 hours. Comparative example: Adhesives c11 to c20 and adhesive c101 to c20, which are the adhesives of the present invention. In comparison with adhesives 101 to 135, in an epoxy adhesive in which component (B) contains an aliphatic amine compound having a polycyclic hydrocarbon structure, under condition I, by adjusting the content of the plasticizer in component (C) to a specific range relative to the epoxy resin of component (A1), and under condition II, by using an epoxy resin containing at least one of the NBR-modified epoxy compound and fluorene-type epoxy compound of component (A2), the curing rate of the cured product obtained under low-temperature curing conditions of 23°C for 72 hours is high at 93-99%, demonstrating excellent low-temperature curing properties, and the glass transition temperature of the cured product with a 100% curing rate is 50-79°C, indicating suppressed molecular chain mobility. As a result, it can be understood that the adhesive of the present invention exhibits unexpected effects, such as the cured product obtained by the curing reaction at low temperatures showing excellent water vapor barrier properties and excellent hot water resistance.In particular, in adhesive I of the present invention, adhesives in which the terminal epoxy compound of component (C) does not contain heteroatoms other than oxygen atoms derived from epoxy groups or glycidyl ether groups are superior in water vapor barrier properties and hot water resistance (adhesives No. 101-109, 111-113 and 115-122 compared to adhesives No. 110 and 114).

[0136] Although we have described the present invention along with its embodiments, we do not intend to limit our invention in any detail of the description unless specifically designated, and we believe that it should be interpreted broadly without contradicting the spirit and scope of the invention as set forth in the appended claims.

[0137] This application claims priority under Japanese Patent Application No. 2024-164886, filed in Japan on 24 September 2024, and Japanese Patent Application No. 2025-047446, filed in Japan on 21 March 2025, which are incorporated herein by reference as part of the description herein.

[0138] 2 Electronic endoscope (endoscope) 3 Insertion section 3a Flexible tube 3b Angle section 3c Tip section 5 Main unit operating section 6 Universal cord 11 Spiral tube 11a Metal strip 12 Cylindrical mesh body 13 Nozzle 14 Flexible tube base material 14a Tip side 14b Base side 15 Resin layer 16 Coating layer 17 Adhesive cured material layer 31 Illumination window 32 Observation window 33 Forceps channel 34 Nozzle 35 Tip section body 36 Tip cap 37 Lens holder 38 Prism 39 Substrate 40 Solid-state image sensor 41 Adhesive cured material 42 Adhesive cured material 43 Observation unit 50 SUS pipe with one end welded and sealed 51 Glass lens 52 Adhesive cured material 53 Test sample 60A, 60B Stainless steel plate 61 Adhesive 62 Adhesion test specimen A Air layer L1-L5 Lens

Claims

1. An endoscope adhesive that satisfies either condition I or II below. (Condition I) It contains the following components (A1) to (C): Component (A1): At least one epoxy resin component selected from bisphenol A type epoxy resin, bisphenol F type epoxy resin, and phenol novolac type epoxy resin (B): An amine compound component which is a curing component of the epoxy resin (C): A terminal epoxy compound represented by the following general formula (1) which is a plasticizer. Component (B) contains an aliphatic amine compound having a polycyclic hydrocarbon structure, and the content of component (C) is 60 to 250 parts by mass per 100 parts by mass of component (A1). In the formula, n is an integer from 1 to 6. R represents an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a heterocyclic group, or a group that is a combination of these groups, and has a valency of n. However, R does not adopt a -phenylene-methylene-phenylene- structure, does not adopt a -phenylene-dimethylmethylene-phenylene- structure, does not have an acrylonitrile butadiene copolymer structure, does not have a fluorene skeleton, and does not bond with the epoxy group in the formula to form a ring. (Condition II) Contains the following components (A2) and (B). Component (A2): An epoxy resin component containing at least one of an acrylonitrile butadiene rubber-modified epoxy compound and an epoxy compound having a fluorene skeleton. (B): An amine compound that is a curing component of the epoxy resin. Component (B) contains an aliphatic amine compound having a polycyclic hydrocarbon structure.

2. The endoscopic adhesive according to claim 1, wherein component (C) does not contain heteroatoms other than oxygen atoms derived from an epoxy group or a glycidyl ether group.

3. The endoscopic adhesive according to claim 1, wherein the proportion of the acrylonitrile butadiene rubber-modified epoxy compound in component (A2) is 20 to 50% by mass.

4. The endoscopic adhesive according to claim 1, wherein component (A2) contains at least the acrylonitrile butadiene rubber-modified epoxy compound, and further contains 10 to 60 parts by mass of component (C) per 100 parts by mass of component (A2). Component (C): A plasticizer, a terminal epoxy compound represented by the general formula (1).

5. The endoscopic adhesive according to claim 1, wherein component (A2) contains at least the epoxy compound having the fluorene skeleton, and the epoxy equivalent of component (A2) is 280 to 420.

6. The endoscopic adhesive according to claim 1, wherein the endoscopic adhesive has a water absorption rate of less than 5.0% by mass when a cured product of the endoscopic adhesive cured to 100% curing rate is immersed in 60°C water for 24 hours.

7. The endoscopic adhesive according to claim 1, wherein the glass transition temperature of the cured product obtained by curing the endoscopic adhesive at a curing rate of 100% is 40 to 80°C.

8. The endoscopic adhesive according to claim 1, further comprising the following component (D): Component (D): at least one of a curing accelerator, an adhesion enhancer, and a filler.

9. A cured product obtained by curing the adhesive for endoscopes according to any one of claims 1 to 8.

10. An endoscope component in which the constituent materials are fixed by the cured product described in claim 9.

11. An endoscope comprising the endoscopic component described in claim 10 as a component.

Images