Electrical connection member

Abstract

Provided is an electrical connection member in which a sealing material is disposed between a terminal and a housing, and in which high sealing performance can be maintained even when the sealing material is in contact with lubricating oil. An electrical connection member (1) is provided with: a terminal (2); a housing (3) that holds the terminal (2); and a sealing material (4) disposed between the terminal (2) and the housing (3), the housing (3) containing a polyester-based resin and / or a polyamide-based resin, the sealing material (4) containing a thermoplastic polymer and being capable of dissolving or swelling with respect to both hexafluoroisopropanol and m-cresol. And the mass change rate is less than 20% when the product is immersed in lubricating oil at 100 DEG C for 8 hours.

Description

TECHNICAL FIELD

[0001] The present application relates to an electric connection member. BACKGROUND

[0002] In an electric connection member in which a terminal is held by a resin-made housing, starting with a terminal holder, there is a problem that water sometimes intrudes into the inside of an apparatus in which the electric connection member is fitted, through a gap between the housing and the terminal. In such a case, it is required to impart sealing property to the electric connection member to suppress the passage of liquid at the portion between the housing and the terminal. As a method of imparting sealing property to the electric connection member, there are a method of working on the material of the housing or the structure of the terminal (Patent Literature 1), a method of filling a potting material in the housing (Patent Literature 2), a method of disposing a sealing material between the housing and the terminal to seal (Patent Literatures 3, 4), and the like.

[0003] According to the method of using a sealing material in the above-mentioned, it is possible to impart sealing property to the electric connection member without designing the terminal into a special structure or providing a portion for receiving a potting resin in the housing. As the sealing material, a rubber-based adhesive is used in Patent Literature 3. The rubber-based adhesive is cured by vulcanization. In addition, as the sealing material, a thermosetting polymer is sometimes used. On the other hand, in Patent Literature 4, as the sealing material, a thermoplastic elastomer resin composition containing an acid-modified styrene-based elastomer, syndiotactic polystyrene, and hydrogenated dicyclopentadiene in predetermined proportions is used. PRIOR ART DOCUMENTS PATENT LITERATURE

[0004] Patent Literature 1: Japanese Patent Application Laid-Open No. 2016-085874 Patent Literature 2: Japanese Patent Application Laid-Open No. 2002-270283 Patent Literature 3: International Publication No. 2017 / 154543 Patent Literature 4: International Publication No. 2011 / 019026 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION

[0005] As described above, in the electric connection member, disposing a sealing material between the housing and the terminal has an effect of suppressing the intrusion of water into the inside of an apparatus in which the electric connection member is provided. Meanwhile, in a case where lubricating oil is used in the inside of the apparatus, the sealing material also exhibits sealing property with respect to the lubricating oil, and it is expected that the leakage of the lubricating oil to the outside of the apparatus via the gap between the housing and the terminal is suppressed. For example, in an automobile driven by an electric motor, a terminal holder is provided to the electric motor, and electric power is transmitted from an inverter to the electric motor via the terminal holder, but in such a terminal holder, in order to suppress the intrusion of water such as rainwater into the electric motor and the leakage of lubricating oil filled into the electric motor, a sealing material is sometimes provided between the housing and the terminal (bus bar).

[0006] In a case where a terminal block is provided in a device containing lubricating oil such as a motor, the sealing material is in a state of being in contact with the lubricating oil in the motor. Thus, in a case where the sealing material is arranged at a portion in contact with the lubricating oil, it is desirable that the sealing material exhibits high sealing properties even in a state of being in contact with the lubricating oil. However, even a sealing material that exhibits high sealing properties in a state of not being in contact with the lubricating oil does not necessarily perform the function of exhibiting high sealing properties in a state of being in contact with the lubricating oil.

[0007] In view of the above, an object is to provide an electric connection member that is provided with a sealing material between a terminal and a housing, and can maintain high sealing properties even in a case where the sealing material is in contact with lubricating oil. Means for solving the problem

[0008] The electric connection member of the present application has: a terminal; a housing that holds the terminal; and a sealing material arranged between the terminal and the housing, the housing containing at least one of a polyester-based resin and a polyamide-based resin, the sealing material containing a thermoplastic polymer, being soluble or swellable with respect to both hexafluoroisopropanol and m-cresol, and having a mass change rate of less than 20% when immersed in lubricating oil at 100°C for 8 hours. Effects of the Invention

[0009] The electric connection member of the present application is provided with a sealing material between a terminal and a housing, and can maintain high sealing properties even in a case where the sealing material is in contact with lubricating oil. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1A 、 1B are side and sectional views each showing a terminal block that is an electric connection member according to an embodiment of the present application. Figure 2 is a side view showing an adhesive test piece. Figure 3A 、 3B are perspective and sectional views each showing a sealing property test piece. In addition, Figure 3C is a schematic view showing a method of performing a sealing property test. DETAILED DESCRIPTION

[0011] [Explanation of Embodiments of the Invention] First, an embodiment of the present application will be explained. The electric connection member of the present application has the following structure.

[0012] [1] The electric connection member of the present application has a terminal, a housing that holds the terminal, and a sealing material disposed between the terminal and the housing, the housing containing at least one of a polyester-based resin and a polyamide-based resin, and the sealing material containing a thermoplastic polymer, being soluble or swellable with respect to both hexafluoroisopropanol and m-cresol, and having a mass change rate of less than 20% when immersed in lubricating oil at 100°C for 8 hours.

[0013] In the electric connection member of the present application having the above structure, since the sealing material disposed between the housing and the terminal contains a thermoplastic polymer, high adhesion to the housing is easily exhibited compared to the case where the sealing material is composed of a polymer cured by vulcanization or a thermosetting polymer. This is because, if the sealing material containing a thermoplastic polymer is disposed on the surface of the terminal, the housing is formed by molding or the like at a portion including the surface of the sealing material while heating is appropriately performed, the sealing material is softened or melted by heat, and, after cooling, is strongly adhered not only to the terminal but also to the housing. Further, in the electric connection member of the present application, since the sealing material is soluble or swellable with respect to both hexafluoroisopropanol and m-cresol, high adhesion to the housing is particularly exhibited. This is because the polyester-based resin and the polyamide-based resin, which are materials constituting the housing, are also materials exhibiting solubility or swellability with respect to hexafluoroisopropanol and m-cresol, and the sealing material has high compatibility with the materials constituting the housing. In this way, high adhesion to the housing is exhibited by the sealing material, and thus high sealing property is obtained in the electric connection member, and penetration of water or lubricating oil through the portion between the housing and the terminal is effectively suppressed. In addition, high adhesion to the housing is exhibited by the sealing material, and even if the sealing material is heated to a high temperature at times, the sealing property of the sealing material can be maintained high.

[0014] Further, the sealing material constituting the electric connection member of the present application has a mass change rate of less than 20% when immersed in lubricating oil at 100°C for 8 hours, and thus changes such as dissolution or swelling are less likely to occur even if the sealing material is in contact with high-temperature lubricating oil. Therefore, even if the electric connection member is used in an environment in which the sealing material is in contact with lubricating oil, high adhesion to the housing exhibited by the sealing material is less likely to be impaired by the influence of the lubricating oil, and a state having high sealing property can be maintained. Thus, the electric connection member of the present application can be appropriately used as a constituent member of a device containing lubricating oil or a device used in an environment in which lubricating oil is present.

[0015] [2] In the method of the above [1], the melting point of the sealing material is preferably 150°C or higher. Thus, even if the electric connection member is used in an environment that becomes a high temperature of 150°C or higher, a decrease in the sealing property due to deterioration that occurs at the melting point of the sealing material or in the vicinity thereof or the like by elution of the sealing material can be avoided, and a high sealing property can be maintained. In an electric motor for a vehicle, the terminal seat is easily heated to a high temperature because a large current is supplied, but a high sealing property can be maintained even at a high temperature, so that the electric connection member of the present application can be appropriately used even in an environment that becomes a high temperature.

[0016] [3] In the method of the above [1] or [2], the sealing material preferably contains a thermoplastic elastomer as the thermoplastic polymer. Thus, by the sealing material having flexibility, even if the electric connection member is used in an environment in which a temperature greatly changes, deterioration due to cold and heat shock is less likely to occur, and a state having a high sealing property is easily maintained.

[0017] [4] In any one of the methods of the above [1] to [3], the sealing material preferably contains at least one of a polyurethane-based resin, a polyester-based resin, and a polyamide-based resin as the thermoplastic polymer. These resin types exhibit a high adhesion to a housing containing at least one of a polyester-based resin and a polyamide-based resin, and are less likely to undergo a change due to lubricating oil, so that they can be appropriately used as a constituent material of the sealing material.

[0018] [5] In any one of the methods of the above [1] to [4], the housing preferably contains at least one of polybutylene terephthalate, nylon 6T, and nylon 9T. These resin types are resins having high mechanical strength and heat resistance, and can be appropriately used to constitute the housing.

[0019] [6] In any one of the methods of the above [1] to [5], the electric connection member is preferably a terminal seat of an electric motor. The terminal seat of an electric motor is a member that is in contact with lubricating oil filled into the electric motor, and is easily heated to a high temperature due to energization of the electric motor, but the electric connection member of the present application can maintain a high sealing property even in an environment in which it is in contact with lubricating oil at a high temperature, so that it can be appropriately used as a terminal seat of an electric motor.

[0020] [Details of Embodiments of the Invention] Hereinafter, an electric connection member according to an embodiment of the present application will be described in detail with reference to the drawings. Hereinafter, regarding various characteristics, a value measured in a room temperature atmosphere is assumed unless otherwise specifically noted. In the present specification, a polymer also includes a polymer having a lower degree of polymerization such as an oligomer.

[0021] [Structure of Electric Connection Member] The electrical connection member of the present invention has terminals and a housing for retaining the terminals, and further provides a sealing material between the terminals and the housing. The electrical connection member is not particularly limited in type as long as it has terminals and a housing and allows for the provision of a sealing material between the terminals and the housing; examples include terminal blocks, connectors, etc. Hereinafter, a terminal block will be described as a preferred example of an electrical connection member.

[0022] Figure 1A , Figure 1B The diagram shows an outline of the terminal block 1, which is an electrical connection member according to one embodiment of the present invention. Figure 1A It is a side view. Figure 1B It means Figure 1A The diagram shows a cross-sectional view of section AA. The terminal block 1 has one or more (three in this case) terminals (busbars) 2 and a housing 3. Sealing material 4 is disposed between each terminal 2 and the housing 3. Additionally, although optional, a rubber ring 5 is disposed on the outer periphery of the housing 3.

[0023] Terminal (busbar) 2 is configured as a rod-shaped or plate-shaped component made of metal. In the illustrated embodiment, terminal 2 is configured as a plate with connection holes at both ends for connecting wires. The material of terminal 2 is not particularly limited. Suitable materials include copper or copper alloys, aluminum or aluminum alloys, iron or iron alloys, or materials with a tin or tin alloy plating layer formed on the surface of these metal materials. In particular, materials with a tin or tin alloy plating layer formed on the surface of a copper or copper alloy substrate are suitable.

[0024] The housing 3 surrounds the outer periphery of the terminal 2 in at least a portion of the terminal 2, holding the terminal 2. In the illustrated embodiment, the housing 3 integrally comprises a block-shaped retaining portion 32 and a flat flange portion 31. The retaining portion 32 is the portion that holds the terminal 2, with each terminal 2 embedded in the retaining portion 32 in the middle region along its long side. The retaining portion 32 arranges the three terminals 2 in parallel with significantly different orientations and holds them together. The flange portion 31 functions as an assembly portion when assembling the terminal holder 1 into a device, etc.

[0025] The housing 3 is composed of a material including at least one of a polyester-based resin and a polyamide-based resin. The polyester-based resin and the polyamide-based resin have high mechanical strength and are also high in heat resistance, and thus are appropriately used as a material for composing the housing 3. In the polymer material for composing the housing 3, it is preferable that at least one of the polyester-based resin and the polyamide-based resin constitute 50% by mass or more, further preferably 90% by mass or more, and most preferably all by mass. As the polyester-based resin, polybutylene terephthalate (PBT) is appropriately used. As the polyamide-based resin, nylon 6T (PA6T) and nylon 9T (PA9T), nylon 66 (PA66), nylon 610 (PA610), and nylon 612 (PA612) are appropriately used. The material for composing the housing 3 can appropriately include an additive such as an anti-aging agent, in addition to the polymer material such as the polyester-based resin and the polyamide-based resin.

[0026] The sealing material 4 is composed of a material including a thermoplastic polymer, which is different from the material for composing the housing 3. The sealing material 4 is arranged between the terminal 2 and the housing 3, and seals the space between the terminal 2 and the housing 3. The sealing material 4 can be provided in the entire region between the terminal 2 and the housing 3, or can be provided only in a part of the region in the illustrated manner. In the illustrated manner, in the region in which the terminal 2 is embedded in the housing 3, the sealing material 4 is arranged so as to surround the entire circumference of the terminal 2 in a part of the region in the longitudinal direction of the terminal 2 (see FIG. 8). Figure 3B In this way, the sealing material 4 seals the space between the terminal 2 and the housing 3 in such a manner as to cut off the communication between the space in which one end of the terminal 2 is arranged (the outer space S1 of the drawing) and the space in which the other end is arranged (the inner space S2 of the drawing).

[0027] The sealing material 4 functions to suppress the movement of a liquid such as water between the outer space S1 and the inner space S2 of the terminal block 1 through the gap between the terminal 2 and the housing 3, by sealing the space between the terminal 2 and the housing 3. That is, the sealing material 4 imparts sealing properties to the terminal block 1. The material for composing the sealing material 4 has predetermined properties, and thus the sealing material 4 exhibits high sealing properties. The material for composing the sealing material 4 will be described in detail later.

[0028] The rubber ring 5 is an O-ring-shaped member composed of an elastomer such as rubber, and is provided to the outer periphery of the housing 3. In the illustrated manner, the rubber ring 5 is provided to a position near the boundary with the flange portion 31 in the holding portion 32 of the housing 3. When the terminal block 1 is assembled to an apparatus or the like, the rubber ring 5 functions to suppress the movement of a liquid such as water between the outer space S1 and the inner space S2 through the gap between the wall surface of the apparatus or the like and the flange portion 31.

[0029] The terminal block 1 is assembled to various devices and can be used as a member for forming an electrical connection between the outside space S1 and the inside space S2. An opening to which the terminal block 1 can be assembled is provided in advance on the device, and the terminal block 1 is assembled by inserting the portion thereof corresponding to the inside space S2 into the opening and fixing the terminal block 1 to the device with the flange portion 31. The portion of the terminal block 1 corresponding to the outside space S1 becomes a state of protruding to the outside of the device. The terminal block 1 has a sealing property, and thus, in the state of being assembled to the device, movement of a liquid in and out of the device via the terminal block 1 is unlikely to occur. That is, movement of a liquid via the gap between the terminal 2 and the housing 3 is inhibited by the sealing material 4, and movement of a liquid via the gap between the housing 3 and the wall surface of the device is inhibited by the rubber ring 5. In particular, the penetration of moisture such as rainwater from the outside of the device into the inside of the device can be effectively inhibited. In addition, an effect can be obtained in terms of inhibiting the phenomenon of a liquid such as lubricating oil disposed in the inside of the device from leaking to the outside of the device.

[0030] The kind of the device to which the terminal block 1 is assembled is not particularly limited, and as will be described later, since the sealing material 4 is composed of a material that can maintain a high sealing property even when in contact with lubricating oil, the terminal block 1 can be appropriately used in a device that uses lubricating oil and is not suitable for water penetration from the viewpoint of effectively utilizing these characteristics. As such a device, an electric motor, particularly an electric motor for an automobile, can be exemplified. In the electric motor for an automobile, since it is necessary to inhibit the penetration of moisture in an outdoor environment such as rainwater, the terminal block 1 is required to have a high water resistance. In addition, since lubricating oil is usually filled in the inside of the electric motor, a sealing property with respect to lubricating oil is also required.

[0031] The method of manufacturing the terminal block 1 is not particularly limited, and any one of a method of assembling each member independently formed and a method of integrally molding can be used. However, integrally molding can be appropriately used. In the case of integrally molding, first, the sealing material 4 is disposed at a predetermined position on the outer periphery of the surface of the terminal 2. At this time, the constituent material of the sealing material 4 is only required to be heated and disposed at the predetermined position in a molten state. In the disposition of the sealing material 4 at the predetermined position, a method such as molding by using a mold, application, or dropping can be used. After the sealing material 4 is disposed at the predetermined position, the housing 3 is formed in a predetermined region including the portion surrounded by the sealing material 4 in a state in which the sealing material 4 is heated to a melting point or a softening temperature or more. The formation of the housing 3 can be performed by molding by using a mold. On the housing 3 formed, the rubber ring 5 is only required to be appropriately assembled on the outer periphery.

[0032] In the above production method, when the sealing material 4 is arranged on the surface of the terminal 2 composed of metal, the constituent material of the sealing material 4 in a molten state or a softened state comes into contact with the surface of the metal material, and thus the sealing material 4 is firmly bonded to the surface of the terminal 2. Also, when the housing 3 is formed, the constituent material of the housing 3 is formed on the surface of the sealing material 4 in a state where the sealing material 4 is heated to a temperature above the melting point or the softening temperature, and thus fusion occurs between the sealing material 4 and the housing 3, and the sealing material 4 is bonded to the housing 3. As for heating the sealing material 4 to a temperature above the melting point or the softening temperature, it can be performed using the heat possessed by the constituent material of the housing 3 at the time of forming the housing 3, or it can be performed by separately heating the sealing material 4 before forming the housing 3. Preferably, from the viewpoint of obtaining high bonding strength between the sealing material 4 and the housing 3, the heating temperature is set to a temperature at which the sealing material 4 is heated to a temperature above the melting point and is molten.

[0033] <Constituent material of sealing material> Next, the constituent material of the sealing material 4 used in the terminal seat (electrical connection member) 1 according to the present embodiment will be described.

[0034] As described above, the sealing material 4 used in the present embodiment is composed of a thermoplastic polymer. By the sealing material 4 containing a thermoplastic polymer, the constituent material of the sealing material 4 as a whole also exhibits thermoplasticity. By the sealing material 4 being composed of a thermoplastic material, high bonding strength can be obtained between the sealing material 4 and the terminal 2 and the housing 3. In particular, as for the adhesiveness between the sealing material 4 and the housing 3, as the sealing material 4, high adhesiveness is easily obtained compared to the case where a polymer cured by vulcanization or a thermosetting polymer is used instead of a thermoplastic polymer. This is because, in the case where a polymer cured by vulcanization or a thermosetting polymer is used, the housing 3 is formed on the surface of the sealing material in a state where the sealing material has already been cured, and thus it is difficult to form firm adhesion on a microscopic scale, in contrast to the case where a thermoplastic polymer is used, as described above in the description of the production method of the terminal seat 1, the housing 3 is formed in a state where the sealing material 4 temporarily arranged on the surface of the terminal 2 is molten or softened by heating, and thus fusion occurs between the sealing material 4 and the constituent material of the housing 3, and tight adhesion is formed by microscopic interaction. From the viewpoint of the effect of improving adhesiveness, it is preferable that 50% by mass or more, further preferably 90% by mass or more, and most preferably all of the polymer material constituting the sealing material 4 be composed of a thermoplastic polymer. Also, the various characteristics described later as the characteristics of the constituent material of the sealing material 4 as a whole are preferably possessed as the characteristics of the thermoplastic polymer constituting the sealing material 4 alone.

[0035] Further, the sealing material 4 used in the present embodiment exhibits particularly high adhesion to the case 3 by having predetermined solubility and swellability. Specifically, the sealing material 4 can dissolve or swell with respect to both hexafluoroisopropanol (HFIP) and m-cresol. Here, the solubility and swellability with respect to HFIP and m-cresol serve as an index of the compatibility of the sealing material 4 and the polymer material constituting the case 3. Among various organic solvents, the solubility parameter (SP value) of HFIP is small, and the SP value of m-cresol is large, but polyester resins and polyamide resins, which are materials constituting the case 3, easily dissolve or swell with respect to both HFIP and m-cresol. In fact, in the examples, it was confirmed that PBT and PA6T, PA9T can dissolve or swell with respect to both HFIP and m-cresol. In detail, it was confirmed that PBT can swell with respect to both solvents, and PA6T and P9T can dissolve with respect to both solvents. The fact that two different materials, the material constituting the sealing material 4 and the material constituting the case 3, can dissolve or swell with respect to the same solvent indicates that the compatibility between the two materials is high, and that the two materials mix with each other at the molecular level when they are brought into contact in a flowable state. That is, it indicates that high adhesion can be obtained at the fusion interface. In the present embodiment, the fact that the material constituting the sealing material 4 can dissolve or swell with respect to both HFIP and m-cresol indicates that the sealing material 4 exhibits high adhesion with respect to the case 3, which is also constituted by a material exhibiting solubility or swellability with respect to these solvents. Among them, if at least one of the material constituting the sealing material 4 and the material constituting the case 3, preferably both, can dissolve with respect to both HFIP and m-cresol, particularly high compatibility and adhesion are obtained between the sealing material 4 and the case 3. As the case 3, polyamide resins such as PA6T and PA9T, which can dissolve with respect to both HFIP and m-cresol, can be particularly suitably used.

[0036] Here, HFIP and m-cresol are used as solvents that serve as an index of the compatibility between the sealing material 4 and the case 3 because they are solvents having intramolecular polarization, and in addition to the fact that the SP values differ to some extent, they are solvents that can easily evaluate the compatibility with polyester resins or polyamide resins, which are polymers having polarization. Furthermore, in the present specification, the phrase that a certain material can dissolve in a certain solvent means a state in which, when a particle of the material is immersed in the solvent, the particle becomes uniform with the solvent at a level that cannot be visually observed. In addition, the phrase that a certain material can swell with respect to a certain solvent means a state in which, when a particle of the material is immersed in the solvent, the particle increases in mass. As the increase in mass, for example, a state in which the mass is more than 1.1 times the mass before immersion in the solvent is meant. As a condition for determining solubility and swellability, a method in which 0.3 g of the sealing material 4 is mixed with 10 ml of the solvent, and left to stand for one week at room temperature can be exemplified, as in the examples described later.

[0037] The sealing material 4 used in the present embodiment has high oil resistance in addition to the above-described dissolving and swelling properties. Specifically, the mass change rate (hereinafter referred to as the oil resistance mass change rate) of the sealing material 4 when immersed in lubricating oil at 100°C for 8 hours is less than 20%. Here, the oil resistance mass change rate of the sealing material 4 is expressed in absolute value as the amount of change in mass, i.e., the decrease or increase, caused by the immersion, based on the mass before the immersion. A mass change rate of less than 20% means that even if the sealing material 4 is in contact with high-temperature lubricating oil, changes such as a decrease in mass due to dissolving and an increase in mass due to swelling are unlikely to occur. That is, it means that the sealing material 4 has high oil resistance, and even if it is in contact with high-temperature lubricating oil, a decrease in adhesion due to the influence of the lubricating oil and penetration of the lubricating oil are unlikely to occur. Further preferably, the oil resistance mass change rate is 10% or less, and further preferably 7% or less. There is no particular lower limit to the oil resistance mass change rate, but it is generally 1% or more. There is no particular limitation on the specific type of lubricating oil used to evaluate the oil resistance mass change rate, but it is preferable to use lubricating oil or the like used in a device in which the terminal block 1 is installed, or lubricating oil with which the sealing material 4 is likely to come into contact. For example, as the lubricating oil, it is preferable to use ATF (Automatic Transmission Fluid). ATF is sometimes filled into a motor for a vehicle.

[0038] As described above, by the sealing material 4 containing a thermoplastic polymer and being able to dissolve or swell with respect to HFIP and m-cresol, high adhesion is exhibited not only with respect to the terminal 2 but also with respect to the housing 3. Therefore, in the terminal block 1, movement of a liquid such as water between the outside space S1 and the inside space S2 via the gap between the housing 3 and the terminal 2 can be firmly suppressed, and high sealing performance can be imparted to the terminal block 1. As a result, in a device in which the terminal block 1 is installed, moisture such as rainwater is effectively suppressed from penetrating from the outside through the portion between the housing 3 and the terminal 2. A higher effect is also obtained in terms of suppressing leakage of a liquid inside the device, such as lubricating oil, to the outside of the device. In addition, by the sealing material 4 exhibiting high adhesion with respect to the terminal 2 and the housing 3, even if the sealing material 4 is placed in an environment that becomes high in temperature, the sealing material 4 can maintain high sealing performance by the adhesion. Further, by suppressing the oil resistance mass change rate of the sealing material 4 to be less than 20%, the sealing material 4 is strongly adhered to the terminal 2 and the housing 3, and even in an environment in which it is in contact with high-temperature lubricating oil, it can maintain a state in which it exhibits high sealing performance. By the sealing material 4 having these properties, the terminal block 1 to which the present embodiment is directed is imparted high sealing performance by the sealing material 4, and even in an environment that becomes high in temperature or an environment in which it is in contact with lubricating oil, it can maintain its sealing performance.

[0039] As described above, the sealing material 4 exhibits high adhesion to the housing 3 by being soluble or swellable with respect to HFIP and m-cresol, and an adhesion strength of, for example, 0.5 MPa or more can be obtained with respect to the housing 3. Further preferably, the adhesion strength is 3 MPa or more. The upper limit of the adhesion strength is not particularly specified, but is approximately 10 MPa or less. The adhesion strength of the sealing material 4 with respect to the housing 3 is, for example, the same as the adhesion strength shown in the following examples, and is evaluated as the shear adhesion strength by performing a tensile shear test on an adhesion test piece in which the sealing material 4 is interposed between a member in which the constituent material of the housing 3 is shaped into a plate and a copper plate, and then bonding them.

[0040] Further, the sealing material 4 preferably has a melting point of 150°C or higher. Thus, the sealing material 4 has high heat resistance, and is less likely to undergo a decrease in adhesion due to elution or modification even when placed in a high-temperature environment. In particular, even in the case where the sealing material 4 has hydrolyzability, hydrolysis and deterioration of the sealing material 4 that can occur when heated to the melting point or near the melting point in a hygroscopic state can be suppressed. In this way, by having a high melting point, the sealing material 4 is particularly suitable for use in applications that are subjected to heating. For example, in a motor for use in an automobile, a large current is supplied via the terminal block 1, and thus the terminal block 1 is likely to become high-temperature. The melting point of the sealing material 4 is more preferably 155°C or higher. The upper limit of the melting point of the sealing material 4 is not particularly specified, but is preferably approximately 200°C or lower from the viewpoint of ease of molding or adhesion due to heating, and the like.

[0041] The specific material constituting the sealing material 4 is not particularly limited, but as the thermoplastic polymer, a thermoplastic elastomer is preferably contained. The thermoplastic elastomer is effective in mitigating cold and heat shocks because of its softness. Thus, the sealing material 4 is less likely to undergo deterioration due to cold and heat shocks, and can maintain high sealing properties even when the terminal block 1 is used in an environment where a large temperature change occurs, such as in an automobile. The elastomer is generally a polymer having a shear elastic modulus of approximately 1 MPa to 200 MPa, and in the present embodiment, a thermoplastic elastomer having a shear elastic modulus of this order is used. It is particularly preferable to use a thermoplastic elastomer having a shear elastic modulus of 150 MPa or less, further 100 MPa or less.

[0042] In addition, as the polymer type of the thermoplastic polymer constituting the sealing material 4, at least one of a polyurethane-based resin, a polyester-based resin, and a polyamide-based resin can be appropriately used. These resins exhibit high adhesion to the terminal 2 composed of a metal and the housing 3 containing a polyester-based resin or a polyamide-based resin, and have high oil resistance. Here, even in the case where the above-described various resins are elastomers, the sealing material 4 particularly preferably contains at least one of a polyurethane-based elastomer, a polyester-based elastomer, and a polyamide-based elastomer as the thermoplastic polymer.

[0043] The sealing material 4 can contain various additives in addition to the polymer material such as the thermoplastic polymer. As an example of a suitable additive, a silane coupling agent can be cited. The sealing material 4 exhibits high adhesion to the terminal 2 by being disposed in a molten state on the surface of the terminal 2 because it contains a thermoplastic polymer, but the adhesion to the terminal 2 can be further improved by adding a silane coupling agent to the sealing material 4. This is because a stable chemical bond is formed between the silane coupling agent and the metal atoms of the metal surface. Furthermore, a tackifier composed of a terpene phenol resin or the like also has the function of improving the adhesion of the sealing material 4 to the metal surface, but many tackifiers are low in oil resistance, and from the viewpoint of suppressing the influence on the oil resistance of the sealing material 4, the use of a silane coupling agent, which is a substance high in oil resistance, is more preferable than the use of a tackifier. As an additive other than a silane coupling agent, pigments for coloring, viscosity regulators, anti-aging agents, inorganic fillers, storage stabilizers, dispersants, and the like can be cited. Example

[0044] An example is shown below. Here, the relationship between the properties possessed by the sealing material and the sealing property is investigated. In the present example, the evaluation of the properties is performed in a room at room temperature in the atmosphere, unless otherwise specified.

[0045] [Production of Test Specimens] As the sealing material, the following materials were prepared. • Sealing material Al: polyurethane-based resin - "Elastollan 1198A" manufactured by BASF Corporation • Sealing material A2: polyester-based resin - "ESTERAR E-D42N" manufactured by ARON KASEI Corporation • Sealing material A3: polyamide-based resin - "VG TPA-2181" manufactured by Tsukano Food Industry Corporation • Sealing material Bl: polystyrene-based resin - "ARBOVAC VF-A90NT" manufactured by ARON KASEI Corporation • Sealing material B2: polyester-based resin - "PENSEL D-125" manufactured by Arakawa Chemical Industries, Ltd. • Sealing material B3: polyolefin-based resin - "MIRASTOMER A970B" manufactured by Mitsui Chemicals, Inc. • Sealing material B4: polyvinyl chloride-based resin - "HIPEX HX71DZ" manufactured by KRAIBURG TPE Corporation All of the above materials are thermoplastic, and are thermoplastic elastomers except for the sealing material B2. In addition, the shear elastic modulus of each material is 100 MPa or less.

[0046] Furthermore, using the aforementioned sealing materials, adhesiveness test pieces for adhesion testing and sealing test pieces for sealing testing are prepared. As adhesiveness test pieces, [the following is a description of the preparation process]. Figure 2 The adhesiveness test piece shown is an adhesiveness test piece with a structure in which a sheet 4a made of sealing material is sandwiched between a copper plate 2a and a resin plate 3a. An adhesiveness test piece P is fabricated, bonded to both the copper plate 2a and the resin plate 3a on its front and back sides respectively. To fabricate the adhesiveness test piece P, firstly, each sealing material is hot-pressed into a sheet with a thickness of 0.5 mm, and then cut into 10 mm × 10 mm pieces. Next, the cut sheet 4a is placed on the copper plate 2a (C1100 material) and heated at 200°C for 20 minutes, thereby bonding it to the copper plate 2a. Further, the copper plate 2a with the bonded sheet 4a is placed in a mold, and on the surface of the sheet 4a, PA6T (DuPont's "HTN54G35EF BK420"), which serves as the shell material, is formed into a plate shape to create the resin plate 3a. The molding process was carried out under the following conditions: nozzle temperature 320℃, mold temperature 140℃, injection speed 60mm / s, and holding pressure 40MPa.

[0047] As a sealing test piece, it was made Figure 3A , 3B The sealing test piece of the structure shown. Figure 3A This is a three-dimensional view of the sealing test piece P'. Figure 3B It means Figure 3A A cross-sectional view of section BB in the figure. The sealing test piece P' mimics a terminal block, with sealing material 4b disposed on a portion of the outer periphery of the model terminal 2b, forming a housing 3b such that it includes the area covering the sealing material 4b. When manufacturing this sealing test piece P', a copper sheet is prepared as the model terminal 2b. The model terminal 2b has dimensions of 12.0 mm × 80.0 mm × 1.6 mm. Sealing material 4b is bonded along the long side of the model terminal 2b in a portion of the area, completely covering the outer periphery. At this time, the sealing material 4b is disposed and bonded to a predetermined position by molding at a temperature 30°C higher than the melting point of each sealing material. The width of the area covered by the sealing material 4b (the dimension along the long side of the model terminal 2b) is 5 mm, and the thickness of the layer of sealing material 4b is 1 mm. Furthermore, a housing 3b is formed on the outer periphery of the model terminal 2b, including the area completely covering the sealing material 4b. The materials and conditions used when forming the shell 3b are the same as those used when forming the resin plate 3a in the above-mentioned adhesiveness test piece P.

[0048] [Evaluation of characteristics] The characteristics of sealing materials A1 to A3 and sealing materials B1 to B4 are evaluated through the following tests.

[0049] (1) Solubility and swelling properties Dissolution and swelling test was performed to evaluate the dissolution and swelling properties of each sealing material, i.e., whether each sealing material dissolves or swells with respect to a solvent. Specifically, as a solvent, 10 ml of HFIP or m-cresol was collected in a glass container, and 0.3 g of each sealing material was mixed to make a granular substance. After the mixture was left to stand at room temperature for one week, it was visually determined whether or not the sealing material dissolved. Further, in the case where the particles of the sealing material dissolved uniformly in the solvent to form a uniform mixture at a level where the particles could not be visually recognized, the sealing material was determined to have dissolved. On the other hand, in the case where the shape of the particles could be visually recognized, the sealing material was determined not to have dissolved. In the case where no dissolution occurred, the mass change was further calculated from the mass before and after immersion in the solvent, and in the case where the mass after immersion was more than 1.1 times the mass before immersion, the sealing material was determined to have swelled. The sample that dissolved was determined to be "A", the sample that did not dissolve but swelled was determined to be "B", and the sample that neither dissolved nor swelled was determined to be "C". Further, in fact, among the sealing materials subjected to the test, there was no material determined to be "B".

[0050] The above dissolution and swelling test was performed on each sealing material, and the following materials that are constituent materials of the housing were also subjected to the dissolution and swelling test in the same manner as described above. Further, it was confirmed in advance that each of the materials exhibited solubility or swellability with respect to both HFIP and m-cresol. • PBT: "CG7030" manufactured by Polyplastics Co., Ltd. - Dissolution and swelling properties: B • PA6T: "HTN 54G35EF BK420" manufactured by DuPont Co. - Dissolution and swelling properties: A • PA9T: "GENESTAR G1300H" manufactured by Kolon Co., Ltd. - Dissolution and swelling properties: A

[0051] (2) Oil resistance mass change rate Each sealing material was collected in an amount of 2 g, and after the mass was measured, the whole was immersed in lubricating oil (ATF "CVTF S-NS-3" manufactured by Shell Lubricants Japan Co., Ltd.). In this state, it was left to stand at 100°C for 8 hours. Then, the sealing material was taken out of the lubricating oil, and after the lubricating oil on the surface was wiped off, the mass of the sealing material was measured. Further, the amount of change in the mass based on the mass of the sealing material before immersion was calculated, and this was taken as the oil resistance mass change rate. The oil resistance mass change rate is independent of the direction of change, and indicates the rate of change in the mass, but in the present embodiment, the change in the direction of mass increase was recorded as a positive value, and the change in the direction of mass decrease was recorded as a negative value.

[0052] (3) Melting point The melting point of each sealing material was measured by a DSC (differential scanning calorimetry) method. In the measurement, the temperature range was from 23°C to 200°C, and the temperature increase rate was 100°C / min.

[0053] (4) Adhesion strength The adhesion strength of the sealing material was measured by a tensile shear test using the adhesion test piece P prepared as described above. At this time, the portions of the copper plate 2a and the resin plate 3a, which were not adhered to the piece 4a composed of the sealing material, were respectively held, and they were set on a tensile testing machine, and a tensile load in the shear direction was applied in parallel with the plate surface as shown by the arrow in Figure 2 In the tensile shear test, the interface between the piece 4a and the copper plate 2a, or the interface between the piece 4a and the resin plate 3b was broken. As for the structure in which the interface between the piece 4a and the resin plate 3a was broken, the load at the time of the breakage was recorded as the adhesion strength of the sealing material with respect to the resin plate 3a, and as for the structure in which the interface between the piece 4a and the copper plate 2a was broken, the load at the time of the breakage was higher than the adhesion strength of the sealing material with respect to the resin plate 3a (the load at the time of the breakage is indicated together with the symbol of ">" in Table 1). The value obtained by dividing the tensile load at the time when the interface between the piece 4a and the resin plate 3a was broken by the adhesion area of the piece 4a with respect to the resin plate 3a was taken as the adhesion strength of the sealing material. If the adhesion strength was 0.5 MPa or more, it was considered that the adhesion was good.

[0054] (5) Sealing property test The sealing property test was performed using the sealing property test piece P' prepared as described above. Before the sealing property test, as the sealing property test piece P', a sealing property test piece subjected to high-temperature standing and a sealing property test piece subjected to oil immersion were prepared. As the high-temperature standing, the sealing property test piece P' was left in an atmosphere at 150°C for 2000 hours. As the oil immersion, the sealing property test piece P' was immersed in ATF (the same ATF as that used for measuring the oil resistance mass change rate described above) at 100°C for 500 hours.

[0055] In the sealing property test, as shown in Figure 3C , the sealing property test piece P' subjected to the high-temperature standing or the oil immersion was fitted to the tip end of the pipe T. At this time, as the pipe T, a pipe having an inner dimension substantially the same as the outer dimension of the housing 3b of the sealing property test piece P' was used, and the sealing property test piece P' was pressed into the tip end of the pipe T at the portion of the housing 3b so that the pipe T and the housing 3b were in close contact with each other. Thus, a space in which the portion from the tip end of the sealing property test piece P' to the middle portion of the housing 3b was housed in the pipe T was formed. Further, the tip end of the pipe T to which the sealing property test piece P' was fitted was immersed in water W stored in a sink. The base end of the pipe T was previously exposed to the outside of the water W so that compressed air A could be introduced from the base end thereof.

[0056] From the base end of the tube T, 10 kPa of compressed air A (pressure is expressed as a difference from atmospheric pressure) was introduced for 30 seconds. During this time, it was visually observed whether or not a bubble B was generated from the boundary between the model terminal 2b of the sealing property test piece P' and the housing 3. Generation of a bubble B means that the portion between the sealing material 4b and the housing 3b was not sufficiently sealed, and compressed air A leaked from this portion. In the case of no leakage of a bubble B, the pressure of the compressed air A was each increased by 10 kPa, and the following process was repeated: that is, the same determination of whether or not a bubble B was generated. Also, the pressure of the compressed air A at which a bubble B began to be generated was recorded as the sealing pressure.

[0057] In the case where the sealing pressure was less than 100 kPa, the sealing property was determined to be low (B). On the other hand, in the case where the sealing pressure was 100 kPa or more and less than 200 kPa, the sealing property was determined to be sufficient (A). Further, in the case where the sealing pressure was 200 kPa or more, the sealing property was determined to be particularly high (A+).

[0058] [Results of Evaluation] In Table 1 below, the results of evaluation are shown for the sealing materials Al to A3, Bl to B4.

[0059] [Table 1]

[0060] According to Table 1, the sealing materials Al to A3 and the sealing materials Bl, B2 were both dissolved in both HFIP and m-cresol. In correspondence with this, for PA6T, an adhesive strength greatly exceeding 0.5 MPa was obtained. On the other hand, in the sealing materials B3, B4, which were neither dissolved nor swelled with respect to these solvents, the adhesive strength was 0 MPa. That is, no (substantial) adhesiveness was exhibited with respect to PA6T.

[0061] From the results of the sealing property test after high-temperature standing, in the sealing materials Al to A3 and the sealing materials Bl, B2, which were both dissolved in both HFIP and m-cresol and exhibited high adhesiveness with respect to PA6T, sufficient sealing properties evaluated as A+ or A were obtained. In particular, in the sealing materials Al to A3, Bl, which had an adhesive strength of 2 MPa or more, high sealing properties evaluated as A+ were obtained. In contrast to this, in the sealing materials B3, B4, which were neither dissolved nor swelled with respect to HFIP and m-cresol and had low adhesiveness with respect to PA6T, the sealing properties after high-temperature standing were reduced (B). From these results, it was known that if the sealing material is such that it is dissolved in both HFIP and m-cresol and exhibits high adhesiveness with respect to the material constituting the housing, then even if the sealing material is heated to a high temperature, sufficient sealing properties with respect to the housing are maintained. Furthermore, the sealing properties after high-temperature standing of the sealing materials Al to A3, Bl were higher than those of the sealing material B2, which was considered to be related to the high melting point in addition to the large adhesive strength.

[0062] Next, in the sealing materials Al to A3 in which the oil mass change rate was suppressed to less than 20% in terms of absolute value, high sealability judged as A or A+ was obtained after oil immersion. Among them, in the sealing materials A2, A3 in which the oil mass change rate was suppressed to 7% or less, particularly high sealability (A+) was obtained. On the other hand, in the sealing materials Bl to B3 in which the oil mass change rate was 20% or more, the sealability after oil immersion became low sealability evaluated as B. The oil mass change rate of the sealing material B4 was suppressed to less than 20 mass%, but because the adhesive strength was 0 MPa, (substantially) no adhesion to the housing, the sealability after oil immersion still became low sealability evaluated as B. With respect to the sealing material Bl, the adhesive strength increased to 2 MPa, high sealability was maintained even after high-temperature placement in the atmosphere, but because the oil mass change rate was large and the oil resistance was low, it was considered that the sealability would decrease by oil immersion. From these results, it can be said that, in order to maintain sufficient sealability even after oil immersion, the sealing material needs to have high oil resistance in which the oil mass change rate is suppressed to less than 20 mass% in addition to being able to dissolve or swell with respect to both HFIP and m-cresol and exhibiting high adhesion to the housing.

[0063] From the above test results, it is shown as follows: in the electrical connection member, when the sealing material is disposed between the terminal and the housing to achieve improvement in sealability, as the sealing material, by using a material that can dissolve or swell with respect to both HFIP and m-cresol and has an oil mass change rate of less than 20 mass%, high sealability can be maintained even in an environment that becomes high temperature and comes into contact with lubricating oil.

[0064] The above describes the embodiments of the present application in detail, but the present application is not limited at all to the above-described embodiments, and various modifications can be made within the scope of the gist of the present application. Explanation of Reference Signs

[0065] 1 terminal seat (electrical connection member) 2 terminal (bus bar) 2a copper plate 2b model terminal 3 housing 3a resin plate 3b housing 31 flange portion 32 holding portion 4 sealing material 4a piece of sealing material 4b sealing material 5 rubber ring A compressed air B bubble P adhesion test piece P' sealing test piece S1 outer space S2 inner space T pipe W water

Claims

1. An electrical connection component, comprising: terminal; Housing, holding the terminals; and A sealing material is disposed between the terminal and the housing. The housing comprises at least one of polyester resin and polyamide resin. The sealing material comprises a thermoplastic polymer. It can dissolve or swell relative to both hexafluoroisopropanol and m-cresol. The mass change rate after immersion in lubricating oil at 100°C for 8 hours is less than 20%.

2. The electrical connection member according to claim 1, wherein, The sealing material has a melting point of 150°C or higher.

3. The electrical connection member according to claim 1 or claim 2, wherein, The sealing material comprises a thermoplastic elastomer as the thermoplastic polymer.

4. The electrical connection member according to claim 1 or claim 2, wherein, The sealing material comprises at least one of polyurethane resin, polyester resin, and polyamide resin as the thermoplastic polymer.

5. The electrical connection member according to claim 1 or claim 2, wherein, The shell contains at least one of polybutylene terephthalate, nylon 6T, and nylon 9T.

6. The electrical connection member according to claim 1 or claim 2, wherein, The electrical connection component is configured as a terminal block for an electric motor.

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